WO2023163149A1 - Optical laminate for oled display device - Google Patents

Abstract

Provided is an optical laminate for use in an OLED display device that does not use a polarizing plate and is not susceptible to interference variations.　The present invention provides an optical laminate for use in an OLED display device in which only an optical element having a degree of polarization of 95% or less is laminated on the viewing side of an OLED element. The optical element has at least an antireflection layer on the viewing side thereof.

Description

Optical laminate for OLED display

The present invention relates to an optical laminate for an OLED display device. More particularly, it relates to an optical laminate used in an OLED display that does not use polarizing plates.

OLED (Organic light emitting diode) display devices have display performance advantages such as high visibility, low viewing angle dependency, and fast response speed compared to liquid crystal display devices. In addition, since the OLED display device does not use a backlight, it is advantageous for thinning, and can be used as a foldable device that can be flexibly curved or folded.

An OLED display device usually has an OLED element in which an anode, an OLED layer including a light-emitting layer, and a cathode are laminated in this order. The electrode (anode or cathode) of the OLED element is made of a transparent conductive material with a high refractive index such as ITO or a metal material with a high reflectance. A glare problem may occur, degrading the display performance of the OLED display device.

In order to suppress adverse effects due to reflection of external light, a proposal has been made to arrange a polarizing plate and a circularly polarizing plate such as a λ/4 plate on the viewing side of the OLED display device (for example, Patent Document 1). Such a circularly polarizing plate also has a function of blocking ultraviolet rays contained in external light and preventing deterioration of the OLED element due to ultraviolet rays. Furthermore, due to the mechanical properties of the circularly polarizing plate itself, it also has the function of absorbing external shocks and preventing damage to the OLED display device.

However, when a circularly polarizing plate is used, the efficiency of light utilization (that is, the lighting rate) is poor due to absorption by the polarizing plate, resulting in low luminance. If the emission intensity of the OLED element is increased to obtain desired luminance, the power consumption increases and the life of the OLED element is shortened. In addition, the polarizing plate has a thickness of about 0.15 mm including an adhesive layer for attachment, which is disadvantageous in reducing the thickness of the OLED display device. Furthermore, since the circularly polarizing plate is expensive, there is also the problem that the manufacturing cost is high.

As an alternative to the circularly polarizing plate, a color filter is placed on the viewing side of the OLED element, and alignment is performed so that the color filter of the same color as the emitted color of the OLED layer faces each other, thereby preventing external light reflection. , a method for improving the luminous intensity of an OLED element has been proposed (for example, Patent Document 2).

An OLED display device having a microcavity (also called multiple reflection interference, optical resonator or microresonator) structure is known as one form of OLED display device. According to the OLED display device having the microcavity structure, the spectrum of the light extracted to the outside becomes steep and high intensity, so it is said that the luminance and color purity can be improved (for example, Patent Document 3).

In an OLED display device, various optical element layers such as an adhesive layer, a base material such as plastic or thin glass, and a hard coat layer are laminated in order to provide functions such as surface protection and flexibility on the viewing side of the OLED element. It is

JP-A-2003-332068 JP 2018-112715 A JP 2015-207377 A

As an alternative to the circularly polarizing plate, a color filter is placed on the viewing side of the OLED element, and alignment is performed so that the color filter of the same color as the emitted color of the OLED layer faces each other, thereby preventing external light reflection. However, the regular two-dimensional structure of the color filter may cause uneven interference of reflected light, impairing the visibility of the OLED display device.

Accordingly, an object of the present invention is to provide an optical laminate used in an OLED display device that does not use a polarizing plate and in which interference unevenness is less likely to occur.

The present inventors have made intensive studies to achieve the above object, and found that in an OLED display device that does not use a polarizing plate, interference unevenness can be reduced by laminating an optical laminate including an antireflection layer on the viewing side of the OLED element. The inventors have found that it is possible to provide a suppressed OLED display device, and completed the present invention.

That is, the present invention provides an optical laminate used in an OLED display device in which only an optical element having a degree of polarization of 95% or less is laminated on the viewing side of the OLED element, the optical element having at least an antireflection layer. An optical stack for an OLED display is provided.

In the reflectance spectrum of the OLED display device without laminating the optical laminate for an OLED display device, the maximum value at a wavelength of 380 to 455 nm was Rp1, and the reflectance of the antireflection layer at the wavelength in Rp1 was Rf1. At this time, [Rf1/Rp1] is preferably 0.3 or less.

In the reflectance spectrum of the OLED display device without laminating the optical layered body for an OLED display device, the maximum value at a wavelength of 460 to 530 nm was Rp2, and the reflectance of the antireflection layer at the wavelength in Rp2 was Rf2. At this time, [Rf2/Rp2] is preferably 0.12 or less.

The sum of [Rf1/Rp1] and [Rf2/Rp2] is preferably 0.42 or less.

The antireflection layer preferably has a water contact angle of 100° or more.

The water contact angle of the antireflection layer after an eraser test is preferably 90° or more.

The antireflection layer is preferably composed of an inorganic substance.

A hard coat layer, a substrate layer, and an adhesive layer are preferably provided on the side opposite to the viewing side of the antireflection layer.

The haze value of the adhesive layer is preferably 20-90%.

The thickness of the hard coat layer is preferably 2 to 10 μm.

An OLED display device in which the optical layered body for an OLED display device of the present invention is laminated on the visible side of the OLED element is less prone to interference unevenness and has excellent visibility.

1 is a schematic cross-sectional view showing one embodiment of an OLED display panel of the present invention; FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device laminated with the optical laminate of the present invention. FIG.

The present invention provides an optical layered body (optical layered body for OLED display device) used in an OLED display device in which only an optical element having a degree of polarization of 95% or less is layered on the viewing side of the OLED element. The optical layered body for an OLED display device of the present invention constitutes the "optical layered body of the present invention", the OLED display device using the optical layered body of the present invention is the "OLED display device of the present invention", and the optical layered body of the present invention. Such an optical element may be referred to as "the optical element of the present invention".

The OLED display device of the present invention comprises, as essential components, an OLED display panel including an OLED element in which an anode, an OLED layer including a light-emitting layer, and a cathode are laminated in this order, and an optical laminate of the present invention on the viewing side of the OLED element. It has a laminated construction. An OLED display panel constituting the OLED display device of the present invention may be referred to as "the OLED display panel of the present invention".

In the OLED display device of the present invention, only an optical element having a degree of polarization of 95% or less is laminated on the OLED display panel on the viewing side of the OLED element. "Only an optical element with a degree of polarization of 95% or less is laminated on the viewing side of the OLED element" means that the optical element on the viewing side of the OLED element does not include an optical element with a degree of polarization exceeding 95%. do. The "optical element having a degree of polarization exceeding 95%" is not particularly limited, but includes polarizing plates such as linear polarizing plates, 1/4 retardation plates, 1/2 retardation plates, circular polarizing plates, and reflective polarizing plates. included. That is, the OLED display device of the present invention is an OLED display device that does not include a polarizing plate on the viewing side of the OLED element.
The degree of polarization is obtained by the following formula based on the parallel transmittance Tp and the orthogonal transmittance Tc, which are measured using an ultraviolet-visible spectrophotometer and subjected to visibility correction.
Degree of polarization (%) = {(Tp-Tc)/(Tp+Tc)} 1/2 x 100

Since the OLED display device of the present invention does not include a polarizing plate on the viewing side of the OLED element, the absorption of light emitted from the OLED element by the polarizing plate is suppressed, the light acceptance rate is improved, and power consumption can be saved. Together with this, it leads to a longer life of the OLED element. In addition, since the polarizing plate is not used, the thickness can be reduced, and the manufacturing cost can be reduced.

The optical element of the present invention has at least an antireflection layer. When the optical element of the present invention has an antireflection layer, the OLED display device of the present invention is less prone to interference unevenness and has excellent visibility, which is preferable.

In another embodiment of the OLED display device of the present invention, the optical element of this embodiment has at least an adhesive layer, and at least one of the adhesive layers may have light scattering properties. preferable. The configuration in which the pressure-sensitive adhesive layer constituting the optical laminate of the present embodiment has light scattering properties suppresses color shift and interference unevenness caused by the OLED display device of the present embodiment, and provides excellent visibility. is suitable.

In another embodiment of the OLED display device of the present invention, a color filter is arranged on the viewing side of the OLED element, and only the optical element of this embodiment is laminated on the viewing side of the color filter. preferable. The optical element of this embodiment has at least an adhesive layer, at least one of the adhesive layers has a light scattering property, and the adhesive layer having the light scattering property and the color filter are The distance (d) between is preferably 700 μm or less. Since the distance between the adhesive layer having light scattering properties and the color filter is 700 μm or less, the light scattering layer is used to suppress color shift and interference unevenness caused by the OLED display device of the present embodiment. is preferable in that image blurring is less likely to occur and visibility is excellent.

In another embodiment of the OLED display device of the present invention, the optical element of this embodiment preferably has at least an antiglare layer. By having the antiglare layer in the optical element of the present embodiment, color shift and interference unevenness caused by the OLED display device of the present embodiment are suppressed, and visibility is excellent.

In another embodiment of the OLED display device of the present invention, the optical element of this embodiment has at least a glass layer and a resin layer, and the glass layer and the resin layer are bonded by an adhesive layer. preferable. In the optical layered body of the present embodiment, the glass layer and the resin layer are adhered by an adhesive layer, which is preferable because the impact resistance of the OLED display device of the present embodiment is improved.

In another embodiment of the OLED display device of the present invention, the optical element of this embodiment preferably has at least a transparent polyimide layer and a hard coat layer. It is preferable that the optical element of the present embodiment has a transparent polyimide layer and a hard coat layer, because the impact resistance of the OLED display device of the present embodiment is improved.
Each configuration will be described below.

(OLED display panel)
The OLED display panel used in the OLED display device of the present invention includes, as essential components, an OLED element in which an anode, an OLED layer including a light-emitting layer, and a cathode are laminated in this order. The optical laminate of the present invention is laminated on the viewing side of the OLED element of the OLED display panel.

An embodiment of the OLED display panel that constitutes the OLED display device of the present invention will be described below with reference to the drawings, but the present invention is not limited to this embodiment.
FIG. 1 is a schematic cross-sectional view showing one embodiment of the OLED display panel of the present invention.

As shown in FIG. 1, the OLED display panel 100 includes a transparent electrode 11a, a red OLED layer 10R that emits red light, a red OLED element 12R in which a back electrode 11b is laminated in this order, the transparent electrode 11a, and a green light. A green OLED element 12G in which a green OLED layer 10G emitting light and a back electrode 11b are stacked in this order, a transparent electrode 11a, and a blue OLED in which a blue OLED layer 10B emitting blue light and a back electrode 11b are stacked in this order. element 12B. OLED elements 12R, 12G, and 12B of respective multiple colors are arranged on substrate 13 in order. A TFT (Thin Film Transistor) layer 14 is formed on the surface of the substrate 13 on which the OLED elements are arranged, and is connected to the back electrodes 11b of the OLED elements 12R, 12G, and 12B of the plurality of colors.

In the OLED display panel 100 of FIG. 1, a color filter 15 is arranged on the visible side (upper side in FIG. 1) of each of the OLED elements 12R, 12G, and 12B of multiple colors. The color filter 15 includes a red colored layer 15R, a green colored layer 15G, and a blue colored layer 15B. A black matrix layer 16 is provided between the colored layers.

In FIG. 1, the color filter 15 is arranged such that the red colored layer 15R, the green colored layer 15G, and the blue colored layer 15B face the red OLED element 12R, the green OLED element 12G, and the blue OLED element 12B, respectively. It is

The transparent electrode 11a is either a cathode or an anode, but is generally provided as a cathode. Transparent conductive materials such as ITO (indium tin oxide), indium oxide, IZO (indium zinc oxide), SnO ₂ and ZnO are used as materials for forming the transparent electrode 11a.

The back electrode 11b functions as a counter electrode for the transparent electrode 11a. A back electrode 11b, which is either an anode or a cathode, is generally provided on the substrate 13 as an anode. Examples of the forming material include metals such as gold, silver, and chromium. Therefore, the back electrode 11b can reflect light.

A bonding layer 17 is provided between the substrate 13 and the color filter 15 . The bonding layer 17 has translucency. As the material of the bonding layer 17, a material used in a general OLED display device may be used. For example, a photocurable resin such as a photosensitive polyimide resin, or a thermosetting resin may be used.

OLED display panel 100 has, in addition to the configuration shown in FIG. (not shown).

A feature of the OLED display panel of FIG. 1 is that color filters 15 are placed on the OLED elements 12R, 12G, and 12B of a plurality of colors so that the colored layers 15R, 15G, and 15B of the same color face each other. It is arranged. As shown in FIG. 1, external light W, which is white, passes through, for example, a red colored layer 15R, passes through a transparent electrode 11a and a red OLED layer 10R that emits red light, and reaches a rear electrode 11b. After being reflected, the reflected light G again passes through the red OLED layer 10R, the transparent electrode 11a, and the red colored layer 15R and enters the observer's eyes.

The green and blue colors of the external light W are absorbed by the red colored layer 15R, so the light intensity is reduced to 1/3. In addition, since the reflected light G passes through the red colored layer 15R and the red OLED layer 10R again, it is attenuated. In addition, since the reflected light G has a red color, the red light emitted from the OLED layer 10R can be enhanced. Likewise, when external light W enters the green colored layer 15G and the blue colored layer 15B, green light and blue light can be enhanced, respectively. Therefore, by using a color filter together with the OLED display panel, it is possible to greatly suppress the reflection of external light and improve the luminous intensity of the OLED element without using a circularly polarizing plate for antireflection.

However, color filters are generally prone to uneven interference due to their regular two-dimensional structure.
In addition, the color filter has a problem in that reflection is likely to occur at the interface, and the lighting efficiency of the light emitted from the OLED element is lowered.
In addition, the color filter does not have a sufficient ultraviolet absorption function compared to the case of using a circularly polarizing plate, and the OLED element is likely to deteriorate over time due to the ultraviolet rays contained in the external light (i.e., the weather resistance is low). There is
Moreover, the color filter has a problem that the impact absorption function is not sufficient as compared with the case of using the circularly polarizing plate.

Also, the OLED display panel 100 of this embodiment has a microcavity structure. Light emitted from the OLED layers 10R, 10G, and 10B passes through the transparent electrode 11a and is emitted to the outside. Here, the emitted light includes "direct light" directly emitted from the OLED layers 10R, 10G, and 10B toward the transparent electrode 11a, and emitted light from the OLED layers 10R, 10G, and 10B toward the back electrode 11b. Both components of the "reflected light" that travels toward the transparent electrode 11a after being reflected by the electrode 11b are included. That is, a first optical path C1 in which part of the light emitted from the OLED layers 10R, 10G, and 10B travels to the transparent electrode 11a side without traveling to the back electrode 11b side and is emitted to the outside through the transparent electrode 11a; The rest of the light emitted from the OLED layers 10R, 10G, and 10B travels toward the back electrode 11b, is reflected by the back electrode 11b, and is then emitted to the outside through the OLED layers 10R, 10G, and 10B and the transparent electrode 11a. A second optical path C2 is formed. The thicknesses of the OLED layers 10R, 10G, and 10B are made different so that the light components corresponding to the respective colors strengthen each other due to interference between the direct light and the reflected light. That is, the OLED layers are arranged such that the optical path length between the back electrode (positive electrode) 11b and the transparent electrode (negative electrode) 11a is matched to the EL spectrum peak wavelength of each of red, green, and blue, and the strongest light is extracted from each color. The thicknesses of 10R, 10G, and 10B are different. Specifically, the short wavelength blue OLED layer 10B is designed to be thin, and the long wavelength red OLED layer 10R is designed to be thick. The light generated in the OLED layer is repeatedly reflected between the positive electrode and the negative electrode, and only the light with the wavelength matching the optical path length is resonated and emphasized, and the light with the other wavelengths with the different optical path length is weakened. , the spectrum of the light extracted to the outside becomes sharp and high intensity, and the luminance and color purity are improved.
According to the OLED display panel having the microcavity structure, although excellent effects of improving luminance and color purity can be obtained, there is a problem that the viewing angle is strongly dependent (the viewing angle is narrow) due to the steep spectrum. can occur. For this reason, when an image is viewed from an oblique direction during image display, a color shift may occur in which the color appears to be different from the color originally desired to be displayed.

(Optical element of the present invention)
The optical element of the present invention is an optical element laminated on the viewing side of an OLED display device, and includes an adhesive layer, an adhesive layer, a resin layer, a glass layer, a hard coat layer, an antireflection layer, an antiglare layer, It contains at least one layer selected from an intermediate layer (compatible layer), an impact absorbing layer, an antistatic layer, and the like. However, the optical elements of the present invention do not include those having a degree of polarization exceeding 95%, such as polarizing plates.

(Adhesive layer)
The adhesive layer is a layer that has adhesiveness at room temperature and adheres to the adherend with light pressure. It refers to the one that maintains a good adhesive strength.

The pressure-sensitive adhesive layer constituting the optical element of the present invention (hereinafter sometimes referred to as "the pressure-sensitive adhesive layer of the present invention"), from the viewpoint of efficiently reducing the color shift and interference unevenness of the OLED display device, light scattering It preferably has a property (a function of scattering light). When the pressure-sensitive adhesive layer of the present invention has light scattering properties, it preferably contains light-scattering fine particles dispersed in the pressure-sensitive adhesive layer.

When the OLED display device of the present invention includes a color filter on the viewing side and the adhesive layer has light scattering properties, the color shift and interference unevenness of the OLED display device are reduced, and the OLED display device caused by light scattering is reduced. From the viewpoint of suppressing image blurring, it is preferable that the distance (d) between the pressure-sensitive adhesive layer having light scattering properties and the color filter is 700 μm or less. From the viewpoint of suppressing image blur of an OLED display device caused by light scattering, the distance between the pressure-sensitive adhesive layer having light scattering properties and the color filter is more preferably 600 μm or less, more preferably 500 μm or less. More preferred. Most preferably, the pressure-sensitive adhesive layer having light scattering properties and the color filter are in direct contact.
The distance between the pressure-sensitive adhesive layer having light scattering properties and the color filter is the distance (μm) between the surface of the pressure-sensitive adhesive layer facing the color filter and the surface of the color filter facing the pressure-sensitive adhesive layer. , When another layer is laminated between the pressure-sensitive adhesive layer having light scattering properties and the color filter, the thickness (μm) of the other layer (in the case of two or more layers, the total) Equivalent to.

The haze value (H) of the adhesive layer of the present invention is not particularly limited, but is preferably 20% or more, more preferably 30% or more, from the viewpoint of efficiently reducing color shift and interference unevenness of the OLED display device. More preferably 40% or more, particularly preferably 50% or more. In addition, from the viewpoint of suppressing image blurring of the OLED display device and displaying a high-definition image, the haze value of the pressure-sensitive adhesive layer of the present invention is preferably 90% or less, more preferably 80% or less, and 70% or less. more preferred.

Although the total light transmittance of the pressure-sensitive adhesive layer of the present invention is not particularly limited, it is preferably 60% or more, more preferably 70% or more, and still more preferably 80% or more from the viewpoint of ensuring the brightness of the OLED display device. Especially preferably, it is 90% or more. Moreover, the upper limit of the total light transmittance of the pressure-sensitive adhesive layer of the present invention is not particularly limited, but may be less than 100%, 99.9% or less, or 99% or less.

The haze value and total light transmittance of the pressure-sensitive adhesive layer of the present invention can be measured by methods defined in JIS K7136 and JIS K7361, respectively. It can be controlled by adjusting the content and the blending amount.

The thickness (T) of the adhesive layer of the present invention is preferably 10 to 100 μm, more preferably 15 to 90 μm, from the viewpoint of efficiently reducing color shift and interference unevenness of the OLED display device. It is more preferably 20-80 μm.

The light-scattering fine particles have an appropriate refractive index difference with the adhesive in the adhesive layer, and impart light scattering properties to the adhesive layer. When the pressure-sensitive adhesive layer contains light-scattering fine particles, light-scattering performance is imparted, which is preferable. Examples of light-scattering fine particles include inorganic fine particles and polymer fine particles. Examples of materials for the inorganic fine particles include silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, talc, and titanium dioxide. Examples of materials for the polymer fine particles include silicone resins, acrylic resins, methacrylic resins (eg, polymethyl methacrylate), polystyrene resins, polyurethane resins, melamine resins, polyethylene resins, and epoxy resins. The light-scattering microparticles are preferably polymer microparticles, and in particular, microparticles composed of silicone resin (e.g., Tospearl series manufactured by Momentive Performance Materials Japan Co., Ltd.) have excellent dispersion in the pressure-sensitive adhesive layer. Adhesive layer with excellent scattering performance showing uniform in-plane haze, which has properties, stability, and an appropriate refractive index difference with the adhesive layer. It is suitable in terms of The shape of the light-scattering fine particles can be spherical, flat, or irregular, for example. The light-scattering fine particles may be used alone or in combination of two or more.

The volume average particle diameter of the light-scattering fine particles is preferably 0.1 µm or more, more preferably 0.15 µm or more, still more preferably 0.2 µm or more, from the viewpoint of imparting appropriate light scattering properties to the pressure-sensitive adhesive layer. More preferably 0.25 μm or more, particularly preferably 1 μm or more. In addition, the volume average particle diameter of the light-scattering fine particles is preferably 12 μm or less, more preferably 10 μm or less, and even more preferably 10 μm or less, from the viewpoint of preventing the haze value from becoming too high and displaying high-definition images. 8 μm or less, particularly preferably 5 μm or less. The volume average particle size can be measured using, for example, a Coulter Counter.

The refractive index (n3) of the light-scattering fine particles is preferably 1.2 to 5, more preferably 1.25 to 4.5, 1.3 to 4, or 1.35 to 3. good too.

The absolute value of the refractive index difference between the light-scattering fine particles and the adhesive in the adhesive layer (adhesive layer excluding the light-scattering fine particles in the adhesive layer) effectively reduces the color shift and interference unevenness of the OLED display device. From the viewpoint of reducing to There may be. In addition, the absolute value of the refractive index difference between the light-scattering fine particles and the pressure-sensitive adhesive is preferably 5 or less from the viewpoint of preventing the haze value from becoming too high, suppressing image blur, and displaying high-definition images. , more preferably 4 or less, and still more preferably 3 or less.

The refractive index (n2) of the adhesive is preferably 1.40 to 1.60, more preferably 1.42 to 1.55, still more preferably 1.43 to 1.50. The refractive index of the pressure-sensitive adhesive can be adjusted by the types and contents of aromatic ring-containing monomers, high-refractive-index organic materials, and high-refractive-index inorganic materials, which will be described later.

From the viewpoint of imparting appropriate light scattering properties to the adhesive layer, the content of the light-scattering fine particles in the adhesive layer is preferably 0.01 per 100 parts by weight of the adhesive constituting the adhesive layer. It is at least 0.05 part by weight, more preferably at least 0.1 part by weight, and particularly preferably at least 0.15 part by weight. In addition, the content of the light-scattering fine particles is 100 parts by weight of the adhesive constituting the adhesive layer from the viewpoint of preventing the haze value from becoming too high, suppressing image blurring, and displaying high-definition images. On the other hand, it is preferably 80 parts by weight or less, more preferably 70 parts by weight or less.

The present invention when the pressure-sensitive adhesive layer of the present invention (particularly, a color filter is arranged on the viewing side of the OLED element and the distance (d) between the pressure-sensitive adhesive layer of the present invention and the color filter is 700 μm or less) The pressure-sensitive adhesive layer) is not particularly limited, but preferably has a high refractive index from the viewpoint of preventing interfacial reflection and improving the lighting efficiency of light emitted from the OLED element. The refractive index of the pressure-sensitive adhesive layer of the present invention is preferably 1.57 or more, more preferably 1.575 or more, and more preferably 1.575 or more, from the viewpoint of preventing interfacial reflection and improving the lighting efficiency of light emitted from the OLED element. It is preferably 1.580 or more, particularly preferably 1.585 or more, still more preferably 1.590 or more, and may be 1.595 or more.
The refractive index of the pressure-sensitive adhesive layer of the present invention can be adjusted by the types and contents of aromatic ring-containing monomers, high-refractive-index organic materials, and high-refractive-index inorganic materials, which will be described later.

The variation ratio of the refractive index of the pressure-sensitive adhesive layer of the present invention before and after humidification is not particularly limited. From the viewpoint, it is preferably 0.05 or less, preferably 0.04 or less, more preferably 0.02 or less, and particularly preferably 0.01 or less.
The variation ratio of the refractive index of the pressure-sensitive adhesive layer of the present invention before and after humidification can be calculated from the following formula after storing the pressure-sensitive adhesive layer of the present invention in a humidified environment at a temperature of 85° C. and a relative humidity of 85% for 120 hours. is.
Refractive index change ratio before and after humidification =|initial refractive index−refractive index after humidification|/(initial refractive index)
The variation ratio of the refractive index before and after humidification depends on the type and content of the aromatic ring-containing monomer, high refractive index organic material, and high refractive inorganic material described later, the type of adhesive constituting the adhesive layer, the monomer composition, the degree of cross-linking, The thickness can be adjusted.

The adhesive constituting the adhesive layer of the present invention is not particularly limited, but for example, acrylic adhesive, rubber adhesive, vinyl alkyl ether adhesive, silicone adhesive, polyester adhesive, polyamide adhesive Adhesives, urethane-based adhesives, fluorine-based adhesives, epoxy-based adhesives, and the like can be used. Among them, acrylic pressure-sensitive adhesives are preferable as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer from the viewpoints of transparency, adhesiveness, weather resistance, cost, and ease of designing the pressure-sensitive adhesive. In other words, the pressure-sensitive adhesive layer of the present invention is preferably an acrylic pressure-sensitive adhesive layer composed of an acrylic pressure-sensitive adhesive. The said adhesive can be used individually or in combination of 2 or more types.

The acrylic pressure-sensitive adhesive layer contains an acrylic polymer as a base polymer. The acrylic polymer is a polymer containing an acrylic monomer (a monomer having a (meth)acryloyl group in the molecule) as a monomer component constituting the polymer. The acrylic polymer is preferably a polymer containing a (meth)acrylic acid alkyl ester as a monomer component constituting the polymer. In addition, an acrylic polymer can be used individually or in combination of 2 or more types.

The adhesive composition forming the adhesive layer of the present invention may be in any form. For example, the pressure-sensitive adhesive composition may be an emulsion type, a solvent type (solution type), an active energy ray-curable type, a heat-melting type (hot-melt type), or the like. Among them, solvent-type and active energy ray-curable pressure-sensitive adhesive compositions are preferable from the viewpoint of productivity and the ease with which a pressure-sensitive adhesive layer having excellent optical properties and appearance can be obtained.

That is, the pressure-sensitive adhesive layer of the present invention is an acrylic pressure-sensitive adhesive layer containing an acrylic polymer as a base polymer, and is preferably formed from a solvent-type or active energy ray-curable acrylic pressure-sensitive adhesive composition.

Examples of the active energy rays include ionizing radiation such as α-rays, β-rays, γ-rays, neutron beams and electron beams, and ultraviolet rays, with ultraviolet rays being particularly preferred. That is, the active energy ray-curable pressure-sensitive adhesive composition is preferably an ultraviolet-curable pressure-sensitive adhesive composition.

As the adhesive composition (acrylic adhesive composition) forming the acrylic adhesive layer, for example, an acrylic adhesive composition containing an acrylic polymer as an essential component, or a unit constituting the acrylic polymer Examples include acrylic pressure-sensitive adhesive compositions containing a mixture of monomers (sometimes referred to as a "monomer mixture") or a partial polymer thereof as an essential component. The former includes, for example, a so-called solvent-type acrylic pressure-sensitive adhesive composition. The latter includes, for example, so-called active energy ray-curable acrylic pressure-sensitive adhesive compositions. The "monomer mixture" means a mixture containing monomer components that constitute a polymer. Further, the "partially polymerized product" may also be referred to as a "prepolymer", and means a composition in which one or more of the monomer components in the monomer mixture is partially polymerized. do.

The acrylic polymer is a polymer composed (formed) of an acrylic monomer as an essential monomer component (monomer component). The acrylic polymer is preferably a polymer composed (formed) of a (meth)acrylic acid alkyl ester as an essential monomer component. That is, the acrylic polymer preferably contains a (meth)acrylic acid alkyl ester as a structural unit. As used herein, "(meth)acryl" represents "acryl" and/or "methacryl" (either or both of "acryl" and "methacryl"), and so on. In addition, the said acrylic polymer is comprised by 1 type, or 2 or more types of monomer components.

As the (meth)acrylic acid alkyl ester as an essential monomer component, a (meth)acrylic acid alkyl ester having a linear or branched alkyl group is preferably mentioned. In addition, (meth)acrylic-acid alkylester can be used individually or in combination of 2 or more types.

The (meth)acrylic acid alkyl ester having a linear or branched alkyl group is not particularly limited, but examples include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, ( meth)isopropyl acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, (meth)acrylate isopentyl acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, (meth)acrylate ) isononyl acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, (meth)acrylate Pentadecyl acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), isostearyl (meth)acrylate, nonadecyl (meth)acrylate, (meth)acrylic (Meth)acrylic acid alkyl esters having a linear or branched alkyl group having 1 to 20 carbon atoms such as eicosyl acid. Among them, the (meth)acrylic acid alkyl ester having a linear or branched alkyl group is preferably a (meth)acrylic acid alkyl ester having a linear or branched alkyl group having 4 to 18 carbon atoms. , and more preferably 2-ethylhexyl acrylate (2EHA) and isostearyl acrylate (ISTA). In addition, the (meth)acrylic acid alkyl esters having a linear or branched alkyl group can be used alone or in combination of two or more.

The ratio of the (meth)acrylic acid alkyl ester in the total monomer components (100% by weight) constituting the acrylic polymer is not particularly limited, but is 50% by weight or more (for example, 50 to 100% by weight). is preferred, more preferably 53 to 90% by weight, and even more preferably 55 to 85% by weight.

The acrylic polymer may contain a copolymerizable monomer together with the (meth)acrylic acid alkyl ester as a monomer component constituting the polymer. That is, the acrylic polymer may contain a copolymerizable monomer as a structural unit. In addition, a copolymerizable monomer can be used individually or in combination of 2 or more types.

The copolymerizable monomer is not particularly limited. is preferably a monomer having an aromatic ring. That is, the acrylic polymer preferably contains a monomer having an aromatic ring in the molecule as a structural unit.

The monomer having an aromatic ring in its molecule is a monomer (monomer) having at least one aromatic ring in its molecule (within one molecule). In this specification, the above-mentioned "monomer having an aromatic ring in the molecule" may be referred to as "aromatic ring-containing monomer".

A compound containing at least one aromatic ring and at least one ethylenically unsaturated group in one molecule is used as the aromatic ring-containing monomer. As the aromatic ring-containing monomer, such compounds can be used singly or in combination of two or more.

Examples of the ethylenically unsaturated groups include (meth)acryloyl groups, vinyl groups, and (meth)allyl groups. A (meth)acryloyl group is preferable from the viewpoint of polymerization reactivity, and an acryloyl group is more preferable from the viewpoint of flexibility and adhesiveness. From the viewpoint of suppressing a decrease in the flexibility of the pressure-sensitive adhesive, as the aromatic ring-containing monomer, a compound having one ethylenically unsaturated group contained in one molecule (that is, a monofunctional monomer) is preferably used.

The number of aromatic rings contained in one molecule of the compound used as the aromatic ring-containing monomer may be one, or two or more. The upper limit of the number of aromatic rings contained in the aromatic ring-containing monomer is not particularly limited, and may be, for example, 16 or less. From the viewpoint of ease of preparation of the acrylic polymer and transparency of the adhesive, the number of the aromatic rings may be, for example, 12 or less, preferably 8 or less, more preferably 6 or less, and 5 It may be less than or equal to 4, less than or equal to 3, or less than or equal to 2.

The aromatic ring possessed by the compound used as the aromatic ring-containing monomer is, for example, a benzene ring (which may be a benzene ring constituting part of a biphenyl structure or a fluorene structure); naphthalene ring, indene ring, azulene ring, anthracene ring, phenanthrene may be a carbocyclic ring, such as a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, an oxazole ring, an isoxazole ring, A heterocyclic ring such as a thiazole ring or a thiophene ring may be used. The heteroatoms included as ring-constituting atoms in the heterocyclic ring may be one or more selected from the group consisting of nitrogen, sulfur and oxygen, for example. The heteroatoms that make up the heterocycle may be one or both of nitrogen and sulfur. The aromatic ring-containing monomer may have a structure in which one or more carbon rings and one or more heterocycles are condensed, such as a dinaphthothiophene structure.

The aromatic ring (preferably carbocyclic ring) may or may not have one or more substituents on the ring-constituting atoms. When having a substituent, the substituent includes an alkyl group, an alkoxy group, an aryloxy group, a hydroxyl group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), a hydroxyalkyl group, a hydroxyalkyloxy group, and a glycidyloxy group. etc. are exemplified, but not limited to these. In substituents containing carbon atoms, the number of carbon atoms contained in the substituent is preferably 1-4, more preferably 1-3, and can be, for example, 1 or 2. The aromatic ring is an aromatic ring having no substituents on ring-constituting atoms or having one or more substituents selected from the group consisting of alkyl groups, alkoxy groups and halogen atoms (e.g., bromine atoms). obtain. The expression that the aromatic ring of the aromatic ring-containing monomer has a substituent on its ring-constituting atom means that the aromatic ring has a substituent other than a substituent having an ethylenically unsaturated group.

The aromatic ring and the ethylenically unsaturated group may be directly bonded or may be bonded via a linking group. The linking group is, for example, an alkylene group, an oxyalkylene group, a poly(oxyalkylene) group, a phenyl group, an alkylphenyl group, an alkoxyphenyl group, or a structure in which one or more hydrogen atoms in these groups are substituted with hydroxyl groups. (eg, hydroxyalkylene group), oxy group (--O-- group), thiooxy group (--S-- group) and the like. An aromatic structure in which an aromatic ring and an ethylenically unsaturated group are directly bonded or bonded via a linking group selected from the group consisting of an alkylene group, an oxyalkylene group and a poly(oxyalkylene) group. Ring-containing monomers may preferably be employed. The number of carbon atoms in the alkylene group and the oxyalkylene group is preferably 1-4, more preferably 1-3, and may be 1 or 2, for example. The number of repeating oxyalkylene units in the poly(oxyalkylene) group may be, for example, 2-3.

Examples of compounds that can be preferably employed as aromatic ring-containing monomers include aromatic ring-containing (meth)acrylates and aromatic ring-containing vinyl compounds. The aromatic ring-containing (meth)acrylate and the aromatic ring-containing vinyl compound can be used singly or in combination of two or more. One or two or more aromatic ring-containing (meth)acrylates and one or two or more aromatic ring-containing vinyl compounds may be used in combination.

When the acrylic polymer contains the aromatic ring-containing monomer as a monomer component constituting the polymer, the proportion of the aromatic ring-containing monomer in the total monomer components (100% by weight) constituting the acrylic polymer is Although not particularly limited, it is preferably 30% by weight or more, more preferably 50% by weight or more, still more preferably 60% by weight or more, and may be 70% by weight or more. When the ratio is 30% by weight or more, a higher refractive index tends to be obtained, which is preferable. From the viewpoint of making it easier to obtain a higher refractive index, the content of the aromatic ring-containing monomer may be, for example, more than 70% by weight, may be 75% by weight or more, may be 80% by weight or more, or may be 85% by weight or more. Well, it may be 90% by weight or more, or 95% by weight or more. Further, the upper limit of the ratio of the aromatic ring-containing monomer is preferably 99% by weight or less, more preferably 98% by weight, from the viewpoint of obtaining a pressure-sensitive adhesive layer having appropriate flexibility and obtaining a pressure-sensitive adhesive layer with excellent transparency. %, more preferably 97% by weight or less, and may be 96% by weight or less. Also, the content of the aromatic ring-containing monomer may be 93% by weight or less, 90% by weight or less, 80% by weight or less, or 75% by weight or less. In some embodiments where adhesive properties and/or optical properties are more important, the content of the aromatic ring-containing monomer may be 70% by weight or less, 60% by weight or less, or 45% by weight or less.

As the aromatic ring-containing monomer, a monomer having two or more aromatic rings (preferably carbocyclic rings) in one molecule can be preferably used because it is easy to obtain a high effect of increasing the refractive index. Examples of monomers having two or more aromatic rings in one molecule (hereinafter also referred to as "multiple aromatic ring-containing monomers") include monomers having a structure in which two or more non-condensed aromatic rings are bonded via a linking group. , a monomer having a structure in which two or more non-condensed aromatic rings are directly (that is, not via other atoms) chemically bonded, a monomer having a condensed aromatic ring structure, a monomer having a fluorene structure, a monomer having a dinaphthothiophene structure , a monomer having a dibenzothiophene structure, and the like. The monomers containing multiple aromatic rings may be used singly or in combination of two or more.

The linking group is, for example, an oxy group (--O--), a thiooxy group (--S--), an oxyalkylene group (eg a --O--(CH ₂ ) _n --- group, where n is 1 to 3, preferably 1). , a thiooxyalkylene group (e.g., a -S-(CH ₂ ) _n - group, where n is 1 to 3, preferably 1), a linear alkylene group (i.e., a -(CH ₂ ) _n - group, where n is 1 to 6, preferably 1 to 3), the alkylene group in the oxyalkylene group, the thiooxyalkylene group and the linear alkylene group may be a partially or completely halogenated group. Preferred examples of the linking group include an oxy group, a thiooxy group, an oxyalkylene group and a linear alkylene group from the viewpoint of the flexibility of the adhesive. Specific examples of monomers having a structure in which two or more non-fused aromatic rings are bonded via a linking group include phenoxybenzyl (meth)acrylate (e.g., m-phenoxybenzyl (meth)acrylate), thiophenoxybenzyl (meth) Acrylate, benzylbenzyl (meth)acrylate and the like.

The monomer having a structure in which two or more non-fused aromatic rings are directly chemically bonded may be, for example, a biphenyl structure-containing (meth)acrylate, a triphenyl structure-containing (meth)acrylate, a vinyl group-containing biphenyl, or the like. Specific examples include o-phenylphenol (meth)acrylate and biphenylmethyl (meth)acrylate.

Examples of monomers having a condensed aromatic ring structure include naphthalene ring-containing (meth)acrylates, anthracene ring-containing (meth)acrylates, vinyl group-containing naphthalenes, and vinyl group-containing anthracenes. Specific examples include 1-naphthylmethyl (meth)acrylate (also known as 1-naphthalenemethyl (meth)acrylate), hydroxyethylated β-naphthol acrylate, 2-naphthoethyl (meth)acrylate, 2-naphthoxyethyl acrylate, 2 -(4-methoxy-1-naphthoxy)ethyl (meth)acrylate and the like.

Specific examples of the monomer having a fluorene structure include 9,9-bis(4-hydroxyphenyl)fluorene (meth)acrylate and 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (meth)acrylate. etc. Since the monomer having a fluorene structure includes a structural portion in which two benzene rings are directly chemically bonded, it is included in the concept of a monomer having a structure in which two or more non-fused aromatic rings are directly chemically bonded.

Examples of the monomer having a dinaphthothiophene structure include (meth)acryloyl group-containing dinaphthothiophene, vinyl group-containing dinaphthothiophene, and (meth)allyl group-containing dinaphthothiophene. Specific examples include (meth)acryloyloxymethyldinaphthothiophene (for example, a compound having a structure in which CH ₂ CH(R ¹ )C(O)OCH ₂ — is bonded to the 5- or 6-position of the dinaphthothiophene ring. and R ¹ is a hydrogen atom or a methyl group), (meth)acryloyloxyethyl dinaphthothiophene (for example, at the 5- or 6-position of the dinaphthothiophene ring, CH ₂ CH(R ¹ )C(O) OCH(CH ₃ )— or a compound having a structure in which CH ₂ CH(R ¹ )C(O)OCH ₂ CH ₂ — is bonded, where R ¹ is a hydrogen atom or a methyl group), vinyldinaphthothiophene (For example, compounds having a structure in which a vinyl group is bonded to the 5th or 6th position of the naphthothiophene ring), (meth)allyloxydinaphthothiophene, and the like. Note that the monomer having a dinaphthothiophene structure is included in the concept of the monomer having a condensed aromatic ring structure by including a naphthalene structure and by having a structure in which a thiophene ring and two naphthalene structures are condensed. be.

Examples of the monomer having a dibenzothiophene structure include (meth)acryloyl group-containing dibenzothiophene and vinyl group-containing dibenzothiophene. A monomer having a dibenzothiophene structure is included in the concept of a monomer having a condensed aromatic ring structure because it has a structure in which a thiophene ring and two benzene rings are condensed.
Neither the dinaphthothiophene structure nor the dibenzothiophene structure corresponds to structures in which two or more non-fused aromatic rings are directly chemically bonded.

A monomer having one aromatic ring (preferably a carbocyclic ring) in one molecule may be used as the aromatic ring-containing monomer. A monomer having one aromatic ring in one molecule can be useful, for example, in improving the flexibility of the pressure-sensitive adhesive, adjusting the pressure-sensitive adhesive properties, improving the transparency, and the like. A monomer having one aromatic ring in one molecule is preferably used in combination with a monomer containing multiple aromatic rings from the viewpoint of improving the refractive index of the pressure-sensitive adhesive.

Examples of monomers having one aromatic ring in one molecule include benzyl (meth)acrylate, methoxybenzyl (meth)acrylate, phenyl (meth)acrylate, ethoxylated phenol (meth)acrylate, phenoxypropyl (meth)acrylate 2-(4, 6-dibromo-2-s-butylphenoxy)ethyl (meth)acrylate, 2-(4,6-dibromo-2-isopropylphenoxy)ethyl (meth)acrylate, 6-(4,6-dibromo-2-s- Butylphenoxy)hexyl (meth)acrylate, 6-(4,6-dibromo-2-isopropylphenoxy)hexyl (meth)acrylate, 2,6-dibromo-4-nonylphenyl acrylate, 2,6-dibromo-4-dodecyl Bromine-substituted aromatic ring-containing (meth)acrylates such as phenyl acrylate; carbon aromatic ring-containing vinyl compounds such as styrene, α-methylstyrene, vinyltoluene, tert-butylstyrene; N-vinylpyridine, N-vinylpyrimidine, N - compounds having a vinyl substituent on a heteroaromatic ring, such as vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, and N-vinyloxazole;

As the aromatic ring-containing monomer, a monomer having a structure in which an oxyethylene chain is interposed between the ethylenically unsaturated group and the aromatic ring in various aromatic ring-containing monomers as described above may be used. A monomer with an oxyethylene chain interposed between the ethylenically unsaturated group and the aromatic ring can be understood as an ethoxylated product of the original monomer. The number of repeating oxyethylene units ( _{--CH.sub.2CH.sub.2O--} ) in _the oxyethylene chain is typically 1-4, preferably 1-3, more preferably 1-2, for example 1. Specific examples of ethoxylated aromatic ring-containing monomers include ethoxylated o-phenylphenol (meth)acrylate, ethoxylated nonylphenol (meth)acrylate, ethoxylated cresol (meth)acrylate, phenoxyethyl (meth)acrylate, and phenoxydiethylene glycol. di(meth)acrylate and the like.

The content of the monomer containing multiple aromatic rings in the aromatic ring-containing monomer is not particularly limited, and may be, for example, 5% by weight or more, 25% by weight or more, or 40% by weight or more. From the viewpoint of easily realizing a pressure-sensitive adhesive having a higher refractive index, the content of the monomer containing multiple aromatic rings in the aromatic ring-containing monomer may be, for example, 50% by weight or more, preferably 70% by weight or more. , 85% by weight or more, 90% by weight or more, or 95% by weight or more. Substantially 100% by weight of the aromatic ring-containing monomer may be the multiple aromatic ring-containing monomer. That is, only one or two or more aromatic ring-containing monomers may be used as the aromatic ring-containing monomer. Further, for example, considering the balance between the high refractive index and the adhesive properties and / or optical properties, the content of the monomer containing multiple aromatic rings in the aromatic ring-containing monomer may be less than 100% by weight, or 98% by weight. 90% by weight or less, 80% by weight or less, or 65% by weight or less. Considering adhesive properties and/or optical properties, the content of the monomer containing multiple aromatic rings in the aromatic ring-containing monomer may be 70% by weight or less, 50% by weight or less, 25% by weight or less, or 10% by weight. % or less. A mode in which the content of the monomer containing multiple aromatic rings in the monomer containing aromatic rings is less than 5% by weight can also be carried out. A monomer containing multiple aromatic rings may not be used.

When the acrylic polymer contains the monomer containing multiple aromatic rings as a monomer component constituting the polymer, the proportion of the monomer containing multiple aromatic rings in the total monomer components (100% by weight) constituting the acrylic polymer. is not particularly limited, but is preferably 3% by weight or more, more preferably 10% by weight or more, and still more preferably 25% by weight or more. When the ratio is 3% by weight or more, a higher refractive index tends to be obtained, which is preferable. From the viewpoint of making it easier to obtain a higher refractive index, the content of the monomer containing multiple aromatic rings may be, for example, more than 35% by weight, may be 50% by weight or more, may be 70% by weight or more, or may be 75% by weight or more. 85% by weight or more, 90% by weight or more, or 95% by weight or more. Further, the upper limit of the ratio of the monomer containing multiple aromatic rings is preferably 99% by weight or less, more preferably 98% by weight or less, from the viewpoint of achieving a good balance between a high refractive index and adhesive properties and/or optical properties. , more preferably 96% by weight or less, may be 93% by weight or less, may be 90% by weight or less, may be 85% by weight or less, or may be 80% by weight or less , 75% by weight or less. Further, from the viewpoint of adhesive properties and/or optical properties, the content of the monomer containing multiple aromatic rings may be 70% by weight or less, 50% by weight or less, 25% by weight or less, or 15% by weight or less. Well, it may be 5% by weight or less.

The copolymerizable monomer is not particularly limited, but from the viewpoint of suppressing cloudiness and improving durability in a high-humidity environment, compatibility with various additives such as ultraviolet absorbers, and transparency, A monomer having a nitrogen atom and a monomer having a hydroxyl group in the molecule are preferred. That is, the acrylic polymer preferably contains a monomer having a nitrogen atom in the molecule as a structural unit. Moreover, the acrylic polymer preferably contains a monomer having a hydroxyl group in the molecule as a structural unit.

The monomer having a nitrogen atom in its molecule is a monomer (monomer) having at least one nitrogen atom in its molecule (within one molecule). In this specification, the "monomer having a nitrogen atom in the molecule" may be referred to as a "nitrogen atom-containing monomer". The nitrogen atom-containing monomer is not particularly limited, but preferably includes a cyclic nitrogen-containing monomer, (meth)acrylamides, and the like. Incidentally, the nitrogen atom-containing monomers can be used alone or in combination of two or more.

The cyclic nitrogen-containing monomer is not particularly limited as long as it has a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or vinyl group and has a cyclic nitrogen structure. The cyclic nitrogen structure preferably has a nitrogen atom in the cyclic structure.

Examples of the cyclic nitrogen-containing monomers include N-vinyl cyclic amides (lactam-based vinyl monomers) and vinyl-based monomers having a nitrogen-containing heterocycle.

Examples of the N-vinyl cyclic amides include N-vinyl cyclic amides represented by the following formula (1).

(In formula (1), R ¹ represents a divalent organic group)

R ¹ in the formula (1) is a divalent organic group, preferably a divalent saturated hydrocarbon group or an unsaturated hydrocarbon group, more preferably a divalent saturated hydrocarbon group (e.g., carbon number 3 to 5 alkylene groups, etc.).

Examples of the N-vinyl cyclic amide represented by the formula (1) include N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, N-vinyl-3-morpholinone and N-vinyl-2-caprolactam. , N-vinyl-1,3-oxazin-2-one, N-vinyl-3,5-morpholinedione, and the like.

Examples of vinyl monomers having a nitrogen-containing heterocyclic ring include acrylic monomers having a nitrogen-containing heterocyclic ring such as a morpholine ring, a piperidine ring, a pyrrolidine ring, and a piperazine ring.

The vinyl-based monomer having a nitrogen-containing heterocycle is not particularly limited, but examples include (meth)acryloylmorpholine, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, N-vinylpyrazine, and N-vinylmorpholine. , N-vinylpyrazole, vinylpyridine, vinylpyrimidine, vinyloxazole, vinylisoxazole, vinylthiazole, vinylisothiazole, vinylpyridazine, (meth)acryloylpyrrolidone, (meth)acryloylpyrrolidine, (meth)acryloylpiperidine and the like. .

Among the vinyl-based monomers having a nitrogen-containing heterocycle, acrylic monomers having a nitrogen-containing heterocycle are preferable, and (meth)acryloylmorpholine, (meth)acryloylpyrrolidine, and (meth)acryloylpiperidine are more preferable.

Examples of the (meth)acrylamides include (meth)acrylamide, N-alkyl(meth)acrylamide, and N,N-dialkyl(meth)acrylamide. Examples of the N-alkyl(meth)acrylamide include N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, Nn-butyl(meth)acrylamide, N-octyl(meth)acrylamide and the like. . Furthermore, the N-alkyl(meth)acrylamides also include (meth)acrylamides having an amino group such as dimethylaminoethyl(meth)acrylamide, diethylaminoethyl(meth)acrylamide, and dimethylaminopropyl(meth)acrylamide. Examples of the N,N-dialkyl(meth)acrylamide include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-diisopropyl (Meth)acrylamide, N,N-di(n-butyl)(meth)acrylamide, N,N-di(t-butyl)(meth)acrylamide and the like.

The (meth)acrylamides also include, for example, various N-hydroxyalkyl(meth)acrylamides. Examples of the N-hydroxyalkyl(meth)acrylamide include N-methylol(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)acrylamide, N- (1-hydroxypropyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(2-hydroxybutyl)(meth)acrylamide, N-(3-hydroxybutyl)(meth)acrylamide, N-(4-hydroxybutyl)(meth)acrylamide, N-methyl-N-2-hydroxyethyl(meth)acrylamide and the like.

The (meth)acrylamides also include, for example, various N-alkoxyalkyl(meth)acrylamides. Examples of the N-alkoxyalkyl(meth)acrylamides include N-methoxymethyl(meth)acrylamide and N-butoxymethyl(meth)acrylamide.

Examples of nitrogen atom-containing monomers other than the cyclic nitrogen-containing monomers and the (meth)acrylamides include amino group-containing monomers, cyano group-containing monomers, imide group-containing monomers, and isocyanate group-containing monomers. Examples of the amino group-containing monomer include aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate. . Examples of the cyano group-containing monomer include acrylonitrile and methacrylonitrile. Examples of the imide group-containing monomer include maleimide-based monomers (eg, N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide, etc.), itaconimide-based monomers (eg, N-methylitaconimide, N- ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-laurylitaconimide, N-cyclohexylitaconimide, etc.), succinimide-based monomers (e.g., N-(meth)acryloyl oxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, N-(meth)acryloyl-8-oxyoctamethylenesuccinimide, etc.). Examples of the isocyanate group-containing monomer include 2-(meth)acryloyloxyethyl isocyanate.

Among them, the nitrogen atom-containing monomer is preferably a cyclic nitrogen-containing monomer, and more preferably an N-vinyl cyclic amide. More specifically, N-vinyl-2-pyrrolidone (NVP) is particularly preferred.

When the acrylic polymer contains the nitrogen atom-containing monomer as a monomer component constituting the polymer, the ratio of the nitrogen atom-containing monomer in the total monomer components (100% by weight) constituting the acrylic polymer is Although not particularly limited, it is preferably 1% by weight or more, more preferably 3% by weight or more, and even more preferably 5% by weight or more. When the ratio is 1% by weight or more, suppression of cloudiness and durability in a high-humidity environment can be further improved, which is preferable. In addition, the upper limit of the ratio of the nitrogen atom-containing monomer is preferably 30% by weight or less, more preferably 25% by weight, from the viewpoint of obtaining a pressure-sensitive adhesive layer having appropriate flexibility and obtaining a pressure-sensitive adhesive layer with excellent transparency. % or less, more preferably 20 wt % or less.

The monomer having a hydroxyl group in the molecule is a monomer having at least one hydroxyl group (hydroxyl group) in the molecule (in one molecule), and has an unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Those having a functional group and a hydroxyl group are preferred. However, the monomer containing a hydroxyl group in the molecule does not include the nitrogen atom-containing monomer. That is, in this specification, a monomer having both a nitrogen atom and a hydroxyl group in its molecule is included in the above-mentioned "nitrogen atom-containing monomer". In this specification, the "monomer having a hydroxyl group in the molecule" may be referred to as a "hydroxyl group-containing monomer". In addition, a hydroxyl-containing monomer can be used individually or in combination of 2 or more types.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, ( Hydroxyl group-containing (meth) 6-hydroxyhexyl acrylate, hydroxyoctyl (meth) acrylate, hydroxydecyl (meth) acrylate, hydroxyl lauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) (meth) acrylate, etc. meth)acrylic acid ester; vinyl alcohol; and allyl alcohol.

Among them, the hydroxyl group-containing monomer is preferably a hydroxyl group-containing (meth)acrylic acid ester, more preferably 2-hydroxyethyl acrylate (HEA) or 4-hydroxybutyl acrylate (4HBA).

When the acrylic polymer contains the hydroxyl group-containing monomer as a monomer component constituting the polymer, the proportion of the hydroxyl group-containing monomer in the total monomer components (100% by weight) constituting the acrylic polymer is particularly limited. However, it is preferably 0.5% by weight or more, more preferably 0.8% by weight or more, and still more preferably 1% by weight from the viewpoint of suppressing cloudiness and improving durability in a high-humidity environment. % or more. Further, the upper limit of the ratio of the hydroxyl group-containing monomer is preferably 30% by weight or less, more preferably 30% by weight or less, from the viewpoint of obtaining a pressure-sensitive adhesive layer having appropriate flexibility and obtaining a pressure-sensitive adhesive layer having excellent transparency. It is 25% by weight or less, more preferably 15% by weight or less.

The total ratio of the nitrogen atom-containing monomer and the hydroxyl group-containing monomer in the total monomer components (100% by weight) constituting the acrylic polymer is not particularly limited, but suppresses clouding in a high-humidity environment. From the viewpoint of improving durability, the content is preferably 1% by weight or more, more preferably 5% by weight or more, and still more preferably 10% by weight or more. In addition, the upper limit of the total of the ratios is preferably 50% by weight or less, more preferably 40% by weight, from the viewpoint of obtaining a pressure-sensitive adhesive layer having moderate flexibility and obtaining a pressure-sensitive adhesive layer with excellent transparency. % or less, more preferably 35 wt % or less.

Copolymerizable monomers other than nitrogen atom-containing monomers and hydroxyl group-containing monomers further include alicyclic structure-containing monomers. The alicyclic structure-containing monomer is not particularly limited as long as it has a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group and has an alicyclic structure. For example, an alkyl (meth)acrylate having a cycloalkyl group is included in the alicyclic structure-containing monomer. In addition, an alicyclic structure containing monomer can be used individually or in combination of 2 or more types.

The alicyclic structure in the alicyclic structure-containing monomer is a cyclic hydrocarbon structure, preferably having 5 or more carbon atoms, more preferably 6 to 24 carbon atoms, further preferably 6 to 15 carbon atoms, and 6 to 10 are particularly preferred.

Examples of the alicyclic structure-containing monomer include cyclopropyl (meth)acrylate, cyclobutyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, cyclooctyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, HPMPA represented by the following formula (2), TMA-2 represented by the following formula (3), HCPA represented by the following formula (4), etc. of acrylic monomers. In the following formula (4), there is no particular limitation on the bonding position between the cyclohexyl ring connected by a line and the structural formula in parentheses. Among these, isobornyl (meth)acrylate is preferred.

When the acrylic polymer contains the alicyclic structure-containing monomer as a monomer component constituting the polymer, the proportion of the alicyclic structure-containing monomer in the total monomer components (100% by weight) constituting the acrylic polymer. is not particularly limited, but is preferably 10% by weight or more from the viewpoint of improving durability. In addition, the upper limit of the ratio of the alicyclic structure-containing monomer is preferably 50% by weight or less, more preferably 40% by weight or less, and still more preferably 30% by weight or less, from the viewpoint of obtaining a pressure-sensitive adhesive layer having appropriate flexibility. is.

Furthermore, copolymerizable monomers include, for example, polyfunctional monomers. Examples of the polyfunctional monomer include hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, Allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate and the like. In addition, a polyfunctional monomer can be used individually or in combination of 2 or more types.

When the acrylic polymer contains the polyfunctional monomer as a monomer component constituting the polymer, the ratio of the polyfunctional monomer in the total monomer components (100% by weight) constituting the acrylic polymer is Although not particularly limited, it is preferably 0.5% by weight or less (for example, more than 0% by weight and 0.5% by weight or less), more preferably 0.2% by weight or less (for example, more than 0% by weight and 0.5% by weight or less). 2% by weight or less).

Further, examples of the copolymerizable monomer include (meth)acrylic acid alkoxyalkyl esters. The (meth)acrylic acid alkoxyalkyl ester is not particularly limited, but examples thereof include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, ( 3-methoxypropyl meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, 4-ethoxybutyl (meth)acrylate and the like. Among them, the alkoxyalkyl (meth)acrylate is preferably an alkoxyalkyl acrylate, more preferably 2-methoxyethyl acrylate (MEA). The (meth)acrylic acid alkoxyalkyl esters may be used alone or in combination of two or more.

When the acrylic polymer contains the (meth)acrylic acid alkoxyalkyl ester as a monomer component constituting the polymer, the ratio of the (meth)acrylic acid alkyl ester and the (meth)acrylic acid alkoxyalkyl ester is Although not particularly limited, the [former: latter] (weight ratio) is preferably more than 100:0 and 25:75 or less, more preferably more than 100:0 and 50:50 or less.

In addition, the copolymerizable monomers include, for example, carboxyl group-containing monomers, epoxy group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, aromatic hydrocarbon group-containing (meth)acrylic acid esters, vinyl esters, aromatic vinyl compounds, olefins or dienes, vinyl ethers, vinyl chloride and the like. Examples of the carboxyl group-containing monomers include (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. Examples of the carboxyl group-containing monomers include maleic anhydride. and anhydride group-containing monomers such as itaconic anhydride. Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate and methylglycidyl (meth)acrylate. Examples of the sulfonic acid group-containing monomer include sodium vinylsulfonate. Examples of the (meth)acrylic ester having an aromatic hydrocarbon group include phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, and benzyl (meth)acrylate. Examples of the vinyl esters include vinyl acetate and vinyl propionate. Examples of the aromatic vinyl compound include styrene and vinyltoluene. Examples of the olefins or dienes include ethylene, propylene, butadiene, isoprene, and isobutylene. Examples of the vinyl ethers include vinyl alkyl ethers.

When the adherend of the pressure-sensitive adhesive layer includes metal or metal oxide wiring such as a touch panel, the acrylic polymer constitutes a polymer in order to obtain an acrylic pressure-sensitive adhesive layer having excellent corrosion resistance. Preferably, the monomer component does not contain or substantially contains no acidic group-containing monomer, and particularly preferably does not contain or substantially contains no carboxyl group-containing monomer. Examples of acidic group-containing monomers include carboxyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, and the like. Specifically, the proportion of the acidic group-containing monomer in the total monomer components (100% by weight) constituting the acrylic polymer is 0.05% by weight or less (preferably 0.01% by weight or less). can be said to be substantially free of

The content of the base polymer (especially acrylic polymer) in the adhesive layer of the present invention is not particularly limited, but is 50% by weight or more (for example, 50% by weight) relative to 100% by weight of the total weight of the adhesive layer of the present invention. to 100% by weight), more preferably 80% by weight or more (eg, 80 to 100% by weight), and still more preferably 90% by weight or more (eg, 90 to 100% by weight).

The base polymer such as the acrylic polymer contained in the pressure-sensitive adhesive layer of the present invention is obtained by polymerizing monomer components. The polymerization method is not particularly limited, but includes, for example, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a polymerization method using active energy ray irradiation (active energy ray polymerization method). Among them, the solution polymerization method and the active energy ray polymerization method are preferable from the viewpoints of the transparency of the pressure-sensitive adhesive layer and the cost.

In addition, various general solvents may be used in the polymerization of the monomer components. Examples of the solvent include esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; cyclohexane, methylcyclohexane and the like. alicyclic hydrocarbons; and organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. In addition, a solvent can be used individually or in combination of 2 or more types.

Upon polymerization of the monomer component, a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator (photoinitiator) may be used depending on the type of polymerization reaction. In addition, a polymerization initiator can be used individually or in combination of 2 or more types.

Examples of the thermal polymerization initiator include, but are not limited to, azo polymerization initiators, peroxide polymerization initiators (eg, dibenzoyl peroxide, tert-butyl permaleate, etc.), redox polymerization initiators, and the like. is mentioned. Among them, the azo polymerization initiator disclosed in JP-A-2002-69411 is preferable. Examples of the azo polymerization initiator include 2,2'-azobisisobutyronitrile (hereinafter sometimes referred to as "AIBN"), 2,2'-azobis-2-methylbutyronitrile (hereinafter, " AMBN”), 2,2′-azobis(2-methylpropionate)dimethyl, 4,4′-azobis-4-cyanovaleric acid and the like. In addition, a thermal polymerization initiator can be used individually or in combination of 2 or more types.

When the azo polymerization initiator is used in the polymerization of the acrylic polymer, the amount of the azo polymerization initiator used is not particularly limited. , preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, and preferably 0.5 parts by weight or less, more preferably 0.3 parts by weight It is below.

The photopolymerization initiator is not particularly limited. Active oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, and the like are included. Other examples include acylphosphine oxide photopolymerization initiators and titanocene photopolymerization initiators. Examples of the benzoin ether photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethan-1-one, anisole methyl ether and the like. Examples of the acetophenone-based photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, 4-phenoxydichloroacetophenone, 4-(t-butyl ) and dichloroacetophenone. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one, and the like. be done. Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2-(O-ethoxycarbonyl)-oxime. Examples of the benzoin-based photopolymerization initiator include benzoin. Examples of the benzyl-based photopolymerization initiator include benzyl. Examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexylphenyl ketone, and the like. Examples of the ketal-based photopolymerization initiator include benzyl dimethyl ketal. Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone. Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide. . Examples of the titanocene photopolymerization initiator include bis(η ⁵ -2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl ) titanium and the like. In addition, a photoinitiator can be used individually or in combination of 2 or more types.

When the photopolymerization initiator is used in the polymerization of the acrylic polymer, the amount of the photopolymerization initiator used is not particularly limited. It is preferably 0.01 parts by weight or more, more preferably 0.1 parts by weight or more, and preferably 3 parts by weight or less, more preferably 1.5 parts by weight or less.

The present invention when the pressure-sensitive adhesive layer of the present invention (particularly, a color filter is arranged on the viewing side of the OLED element and the distance (d) between the pressure-sensitive adhesive layer of the present invention and the color filter is 700 μm or less) is not particularly limited, but preferably contains a high refractive index organic material. When the pressure-sensitive adhesive layer of the present invention contains a high-refractive-index organic material, a high-refractive-index pressure-sensitive adhesive layer can be obtained, interfacial reflection with an OLED display panel can be suppressed, and the acceptance rate of light from the OLED element can be improved. ,preferable. The high refractive index organic material can be used alone or in combination of two or more.

A high refractive index organic material means an organic material with a high refractive index. By using such a high refractive index organic material in combination with an acrylic polymer, it is possible to improve the refractive index, adhesive properties (peel strength, flexibility, etc.) and/or optical properties (total light transmittance, haze value, etc.). A suitably compatible pressure sensitive adhesive can be achieved. The organic material used as the high refractive index organic material may be a polymer or a non-polymer. Moreover, it may or may not have a polymerizable functional group.

The refractive index of the high-refractive-index organic material is not limited to a specific range because it can be set within an appropriate range in relation to the refractive index of the acrylic polymer. Preferably, the high refractive index organic material has a refractive index greater than 1.50, greater than 1.55 or greater than 1.57, and higher than the refractive index of the acrylic polymer. From the viewpoint of increasing the refractive index of the adhesive, the refractive index of the high refractive index organic material is advantageously 1.58 or more, preferably 1.60 or more, and 1.63 or more. is more preferable, and may be 1.65 or more, 1.70 or more, or 1.75 or more. With a high refractive index organic material having a higher refractive index, a target refractive index can be achieved even by using a smaller amount of the high refractive index organic material. This is preferable from the viewpoint of suppressing deterioration of adhesive properties and optical properties. The upper limit of the refractive index of the high-refractive-index organic material is not particularly limited. 2.500 or less, 2.000 or less, 1.950 or less, 1.900 or less, or 1.850 or less. Moreover, the high refractive index organic material can also be one that functions as a plasticizer that imparts flexibility to the pressure-sensitive adhesive layer.
The high refractive index organic material and the refractive index of the pressure-sensitive adhesive layer are measured using an Abbe refractometer under conditions of a measurement wavelength of 589 nm and a measurement temperature of 25°C. If the manufacturer or the like provides the nominal value of the refractive index at 25° C., the nominal value can be adopted.

The difference between the refractive index n _b of the high refractive index organic material and the refractive index _na of the acrylic polymer, that is, n _{b −na} (hereinafter also referred to as “Δn _A ”) is set to be greater than 0. be. Δn _A is, for example, 0.02 or more, 0.05 or more, 0.07 or more, 0.10 or more, 0.15 or more, 0.20 or more, or 0.25 or more good. By selecting the acrylic polymer and the high refractive index organic material so that Δn _A becomes larger, the effect of improving the refractive index by using the high refractive index organic material tends to be enhanced. Further, from the viewpoint of compatibility of the high refractive index organic material in the adhesive layer, Δn _A may be, for example, 0.70 or less, 0.60 or less, 0.50 or less, or 0.40 or less, or 0.35 or less.

The difference between the refractive index n _b of the high refractive index organic material and the refractive index n _T of the adhesive layer containing the high refractive index organic material, that is, n _b −n _T (hereinafter also referred to as “Δn _B ”) is , may be set to be greater than zero. In some embodiments, Δn _B is, for example, 0.02 or greater, 0.05 or greater, 0.07 or greater, 0.10 or greater, 0.15 or greater, or 0.20 or greater. Alternatively, it may be 0.25 or more. By selecting the composition of the pressure-sensitive adhesive layer and the high refractive index organic material so as to increase Δn _B , the effect of improving the refractive index by using the high refractive index organic material tends to increase. Further, from the viewpoint of compatibility in the pressure-sensitive adhesive layer, transparency of the pressure-sensitive adhesive layer, etc., in some embodiments, Δn _B may be, for example, 0.70 or less, 0.60 or less, It may be 0.50 or less, 0.40 or less, or 0.35 or less.

The molecular weight of the organic material used as the high refractive index organic material is not particularly limited, and can be selected depending on the purpose. From the viewpoint of achieving a good balance between the effect of increasing the refractive index and other properties (e.g., flexibility suitable for adhesives, optical properties such as haze), the molecular weight of the high refractive index organic material is approximately less than 10,000. preferably less than 5,000, more preferably less than 3,000 (eg, less than 1,000), less than 800, less than 600, less than 500, or less than 400. It may be advantageous from the viewpoint of improving compatibility in the pressure-sensitive adhesive layer that the molecular weight of the high refractive index organic material is not too large. Also, the molecular weight of the high refractive index organic material may be, for example, 130 or more, or 150 or more. From the viewpoint of increasing the refractive index of the high refractive index organic material, the molecular weight of the high refractive index organic material is preferably 170 or more, more preferably 200 or more, may be 230 or more, or may be 250 or more. , 270 or more, 500 or more, 1000 or more, or 2000 or more. A polymer having a molecular weight of about 1000 to 10000 (for example, 1000 or more and less than 5000) can be used as the high refractive index organic material.
As for the molecular weight of the high refractive index organic material, for non-polymers or polymers with a low degree of polymerization (for example, about 2- to 5-mers), the molecular weight calculated based on the chemical structure, or the matrix-assisted laser desorption ionization flight Measurements using time-based mass spectrometry (MALDI-TOF-MS) can be used. If the high refractive index organic material is a polymer with a higher degree of polymerization, the weight average molecular weight (Mw) based on GPC performed under appropriate conditions can be used. When the nominal value of the molecular weight is provided by the manufacturer or the like, the nominal value can be adopted.

Examples of organic materials that can be selected as high refractive index organic materials include organic compounds having aromatic rings, organic compounds having heterocyclic rings (which may be aromatic rings or non-aromatic heterocyclic rings), and the like. but not limited to these.

The aromatic ring of the organic compound having an aromatic ring (hereinafter also referred to as "aromatic ring-containing compound") used as the high refractive index organic material is the same as the aromatic ring of the compound used as the aromatic ring-containing monomer. can be selected from

The aromatic ring may have one or more substituents on the ring-constituting atoms, or may have no substituents. When having a substituent, the substituent includes an alkyl group, an alkoxy group, an aryloxy group, a hydroxyl group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), a hydroxyalkyl group, a hydroxyalkyloxy group, and a glycidyloxy group. etc. are exemplified, but not limited to these. In the substituent containing carbon atoms, the number of carbon atoms contained in the substituent is, for example, 1 to 10, preferably 1 to 6, preferably 1 to 4, more preferably 1 to 3. and can be, for example, 1 or 2. The aromatic ring is an aromatic ring having no substituents on ring-constituting atoms or having one or more substituents selected from the group consisting of alkyl groups, alkoxy groups and halogen atoms (e.g., bromine atoms). obtain.

Examples of aromatic ring-containing compounds that can be used as high refractive index organic materials include: compounds that can be used as aromatic ring-containing monomers; oligomers that contain compounds that can be used as aromatic ring-containing monomers as monomer units; aromatic ring-containing monomers from a compound that can be used as a group having an ethylenically unsaturated group (which may be a substituent bonded to a ring-constituting atom) or a hydrogen atom or ethylene a compound having a structure substituted with a group having no polyunsaturated group (e.g., hydroxyl group, amino group, halogen atom, alkyl group, alkoxy group, hydroxyalkyl group, hydroxyalkyloxy group, glycidyloxy group, etc.); but not limited to these. Non-limiting examples of aromatic ring-containing compounds that can be used as high refractive index organic materials include benzyl acrylate, m-phenoxybenzyl acrylate, 2-(o-phenylphenoxy)ethyl acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate. , phenoxypolyethylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, monomers having a fluorene structure described above, monomers having a dinaphthothiophene structure, monomers having a dibenzothiophene structure, and other aromatic ring-containing monomers; 3-phenoxybenzyl alcohol , dinaphthothiophene and derivatives thereof (for example, a structure in which one or more substituents selected from a hydroxy group, a methanol group, a diethanol group, a glycidyl group, etc. are bonded to the dinaphthothiophene ring. aromatic ring-containing compounds having no ethylenically unsaturated groups, such as compounds of (); Further, the aromatic ring-containing compound is an oligomer containing such an aromatic ring-containing monomer as a monomer unit (preferably an oligomer having a molecular weight of about 5000 or less, more preferably about 1000 or less. For example, a low polymer of about 2 to 5 mers ). The oligomers are, for example: homopolymers of aromatic ring-containing monomers; copolymers of one or more aromatic ring-containing monomers; copolymers of one or more aromatic ring-containing monomers with other monomers. coalescence; and the like. As the other monomer, one or more monomers having no aromatic ring may be used.

In some aspects, as the high refractive index organic material, an organic compound having two or more aromatic rings in one molecule (hereinafter referred to as "a compound containing multiple aromatic rings") is used because it is easy to obtain a high refractive index increasing effect. Also called.) can be preferably adopted. The compound containing multiple aromatic rings may or may not have a polymerizable functional group such as an ethylenically unsaturated group. Moreover, the compound containing multiple aromatic rings may be a polymer or a non-polymer. In addition, the polymer is an oligomer (preferably an oligomer having a molecular weight of about 5000 or less, more preferably about 1000 or less; for example, a low polymer of about 2 to 5 mers) containing multiple aromatic ring-containing monomers as monomer units. obtain. The oligomer is, for example: a homopolymer of a monomer containing multiple aromatic rings; a copolymer of one or more monomers containing multiple aromatic rings; a monomer containing one or more than two aromatic rings and another monomer. a copolymer of; The other monomer may be an aromatic ring-containing monomer that does not correspond to a monomer containing multiple aromatic rings, a monomer having no aromatic ring, or a combination thereof.

Non-limiting examples of compounds containing multiple aromatic rings include compounds having a structure in which two or more non-fused aromatic rings are linked via a linking group, two or more non-fused aromatic rings directly (i.e., other atoms compounds having a chemically bonded structure, compounds having a condensed aromatic ring structure, compounds having a fluorene structure, compounds having a dinaphthothiophene structure, compounds having a dibenzothiophene structure, and the like. The compounds containing multiple aromatic rings may be used singly or in combination of two or more.

Specific examples of the compound having a fluorene structure include the above-described monomers having a fluorene structure, oligomers that are homopolymers or copolymers of such monomers, and 9,9-bis(4-hydroxyphenyl)fluorene ( refractive index: 1.68), 9,9-bis(4-aminophenyl)fluorene (refractive index: 1.73), 9,9-bis(4-hydroxy-3-methylphenyl)fluorene (refractive index: 1 .68), 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (refractive index: 1.65) and its derivatives.

Specific examples of the compound having a dinaphthothiophene structure include the above-described monomers having a dinaphthothiophene structure, oligomers that are homopolymers or copolymers of such monomers, and dinaphthothiophene (refractive index: 1.0). 808); hydroxyalkyldinaphthothiophenes such as 6-hydroxymethyldinaphthothiophene (refractive index: 1.766); dihydroxydinaphthothiophenes such as 2,12-dihydroxydinaphthothiophene (refractive index: 1.750); , 12-dihydroxyethyloxydinaphthothiophene (refractive index: 1.677); diglycidyloxydinaphthothiophene (refractive index: 1.723); naphthothiophene; dinaphthothiophene having two or more ethylenically unsaturated groups such as 2,12-diallyloxydinaphthothiophene (abbreviation: 2,12-DAODNT, refractive index 1.729); Derivatives thereof may be mentioned.

Specific examples of the compound having a dibenzothiophene structure include the above-described monomers having a dibenzothiophene structure, oligomers that are homopolymers or copolymers of such monomers, dibenzothiophene (refractive index: 1.607), 4-dimethyldibenzothiophene (refractive index: 1.617), 4,6-dimethyldibenzothiophene (refractive index: 1.617) and the like.

Examples of organic compounds having a heterocyclic ring (hereinafter also referred to as heterocyclic ring-containing organic compounds) that can be options for high refractive index organic materials include thioepoxy compounds and compounds having a triazine ring. Examples of thioepoxy compounds include bis(2,3-epithiopropyl)disulfide and its polymer (refractive index: 1.74) described in Japanese Patent No. 3712653. Examples of compounds having a triazine ring include compounds having at least one (eg, 3 to 40, preferably 5 to 20) triazine rings in one molecule. In addition, since the triazine ring has aromaticity, the compound having a triazine ring is also included in the concept of the compound containing the aromatic ring, and the compound having multiple triazine rings is also included in the concept of the compound containing multiple aromatic rings. be done.

A compound having no ethylenically unsaturated group can be preferably employed as the high refractive index organic material. As a result, deterioration of the pressure-sensitive adhesive composition due to heat or light (decrease in leveling properties due to progression of gelation or increase in viscosity) can be suppressed, and storage stability can be enhanced. Employing a high refractive index organic material that does not have an ethylenically unsaturated group means that an adhesive film having an adhesive layer containing the high refractive index organic material, a laminate including the adhesive film, or the like has ethylenically unsaturated It is also preferable from the viewpoint of suppressing dimensional change and deformation (warpage, waviness, etc.), optical distortion, etc. caused by reaction of groups.

In embodiments where an oligomer is used as the high refractive index organic material, the oligomer can be obtained by polymerizing the corresponding monomer component by a known method. When the oligomer is produced by radical polymerization, polymerization can be carried out by appropriately adding a polymerization initiator, a chain transfer agent, an emulsifier, etc. used for radical polymerization to the monomer component. The polymerization initiator, chain transfer agent, emulsifier and the like used in the radical polymerization are not particularly limited and can be appropriately selected and used. The weight-average molecular weight of the oligomer can be controlled by adjusting the amount of the polymerization initiator and the chain transfer agent used and the reaction conditions, and the amount used is appropriately adjusted according to these types.

Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, α-thioglycerol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2,3-dimercapto-1-propanol, and the like. be done. A chain transfer agent may be used individually by 1 type, and may be used in mixture of 2 or more types. The amount of the chain transfer agent used can be set according to the composition of the monomer components used in the synthesis of the oligomer, the type of the chain transfer agent, etc., so as to obtain an oligomer having a desired weight-average molecular weight. In some embodiments, the amount of the chain transfer agent used for 100 parts by weight of the total amount of monomers used in the synthesis of the oligomer is suitably about 15 parts by weight or less, may be 10 parts by weight or less, or may be 5 parts by weight. It may be less than a degree. The lower limit of the amount of the chain transfer agent to be used with respect to 100 parts by weight of the total amount of monomers used for the synthesis of the oligomer is not particularly limited. It may be 5 parts by weight or more, or 1 part by weight or more.

The amount of the high-refractive-index organic material used relative to 100 parts by weight of the acrylic polymer (the total amount thereof when multiple types of compounds are used) is not particularly limited as long as it exceeds 0 parts by weight, and is set according to the purpose. be able to. The amount of the high refractive index organic material used relative to 100 parts by weight of the acrylic polymer can be, for example, 80 parts by weight or less, achieving both a high refractive index of the adhesive and suppression of deterioration in adhesive properties and optical properties in a well-balanced manner. From the point of view, it is advantageous to use 60 parts by weight or less, preferably 45 parts by weight or less. From the viewpoint of emphasizing adhesive properties and optical properties, the amount of the high refractive index organic material used relative to 100 parts by weight of the acrylic polymer may be, for example, 30 parts by weight or less, 20 parts by weight or less, or 15 parts by weight or less. or less than 10 parts by weight. In addition, from the viewpoint of increasing the refractive index of the adhesive, the amount of the high refractive index organic material used relative to 100 parts by weight of the acrylic polymer can be, for example, 1 part by weight or more, and is preferably 3 parts by weight or more. It is preferably 5 parts by weight or more, may be 7 parts by weight or more, may be 10 parts by weight or more, may be 15 parts by weight or more, or may be 20 parts by weight or more.

Although the adhesive layer of the present invention is not particularly limited, it preferably contains an ultraviolet absorber (UVA). When the pressure-sensitive adhesive layer of the present invention contains an ultraviolet absorber, it is possible to suppress deterioration of the OLED element due to ultraviolet rays contained in external light, and to obtain an OLED display device having excellent weather resistance without using a polarizing plate. In addition, deterioration of the high refractive index component due to ultraviolet rays can be suppressed, and a high lighting efficiency can be maintained. In addition, an ultraviolet absorber can be used individually or in combination of 2 or more types.

Examples of the ultraviolet absorber include, but are not limited to, benzotriazole-based ultraviolet absorbers, hydroxyphenyltriazine-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, salicylic acid ester-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, oxy Examples include benzophenone-based ultraviolet absorbers.

Benzotriazole-based UV absorbers (benzotriazole-based compounds) include, for example, 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole (trade name "TINUVIN PS", manufactured by BASF), benzene Ester compound of propanoic acid and 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy (C7-9 side chain and linear alkyl) (trade name "TINUVIN 384 -2", manufactured by BASF), octyl 3-[3-tert-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate and 2-ethylhexyl-3-[ A mixture of 3-tert-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2yl)phenyl]propionate (trade name "TINUVIN 109", manufactured by BASF), 2-(2H-benzotriazole -2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (trade name "TINUVIN 900", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-6- (1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (trade name "TINUVIN 928", manufactured by BASF), methyl 3-(3-(2H-benzotriazole) -2-yl)-5-tert-butyl-4-hydroxyphenyl)propionate/polyethylene glycol 300 reaction product (trade name "TINUVIN 1130", manufactured by BASF), 2-(2H-benzotriazol-2-yl )-p-cresol (trade name “TINUVIN P”, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (trade name "TINUVIN 234", manufactured by BASF), 2-[5-chloro-2H-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol (trade name "TINUVIN 326", manufactured by BASF) ), 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (trade name “TINUVIN 328”, manufactured by BASF), 2-(2H-benzotriazol-2-yl) -4-(1,1,3,3-tetramethylbutyl)phenol (trade name "TINUVIN 329", manufactured by BASF), 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)- 4-(1,1,3,3-tetramethylbutyl)phenol] (trade name “TINUVIN 360”, manufactured by BASF), methyl 3-(3-(2H-benzotriazol-2-yl)-5-tert -Butyl-4-hydroxyphenyl)propionate and polyethylene glycol 300 reaction product (trade name "TINUVIN 213", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-6-dodecyl-4- Methylphenol (trade name "TINUVIN 571", manufactured by BASF), 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimido-methyl)-5-methylphenyl]benzotriazole (trade name " Sumisorb 250", manufactured by Sumitomo Chemical Co., Ltd.), 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenol] (trade name "ADEKA STAB LA-31", ) manufactured by ADEKA) and the like.

Hydroxyphenyltriazine-based UV absorbers (hydroxyphenyltriazine-based compounds) include, for example, 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5 - Reaction product of hydroxyphenyl and [(C10-C16 (mainly C12-C13) alkyloxy) methyl] oxirane (trade name “TINUVIN 400” manufactured by BASF), 2-[4,6-bis(2, 4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-[3-(dodecyloxy)-2-hydroxypropoxy]phenol), 2-(2,4-dihydroxyphenyl)-4, Reaction product of 6-bis-(2,4-dimethylphenyl)-1,3,5-triazine and (2-ethylhexyl)-glycidate (trade name “TINUVIN 405”, manufactured by BASF), 2,4 -bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3,5-triazine (trade name “TINUVIN 460”, manufactured by BASF), 2-(4, 6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol (trade name “TINUVIN 1577”, manufactured by BASF), 2-(4,6-diphenyl-1 ,3,5-triazin-2-yl)-5-[2-(2-ethylhexanoyloxy)ethoxy]-phenol (trade name “ADEKA STAB LA-46”, manufactured by ADEKA Corporation), 2-(2 -Hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine (trade name “TINUVIN 479”, manufactured by BASF) and the like. be done. In addition, a compound represented by the following formula (5) (trade name “TINUVIN 477”, manufactured by BASF) can be used.

Benzophenone UV absorbers (benzophenone compounds) and oxybenzophenone UV absorbers (oxybenzophenone compounds) include, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4- Methoxybenzophenone-5-sulfonic acid (anhydrous and trihydrate), 2-hydroxy-4-octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2'- Dihydroxy-4-methoxybenzophenone (trade name "KEMISORB 111", manufactured by Chemipro Kasei Co., Ltd.), 2,2',4,4'-tetrahydroxybenzophenone (trade name "SEESORB 106", manufactured by Sipro Kasei Co., Ltd.) , 2,2′-dihydroxy-4,4′-dimethoxybenzophenone and the like.

Salicylic acid ester-based ultraviolet absorbers (salicylic acid ester-based compounds) include, for example, phenyl 2-acryloyloxybenzoate, phenyl 2-acryloyloxy-3-methylbenzoate, phenyl 2-acryloyloxy-4-methylbenzoate, phenyl 2- acryloyloxy-5-methylbenzoate, phenyl 2-acryloyloxy-3-methoxybenzoate, phenyl 2-hydroxybenzoate, phenyl 2-hydroxy-3-methylbenzoate, phenyl 2-hydroxy-4-methylbenzoate, phenyl 2-hydroxy- 5-methylbenzoate, phenyl 2-hydroxy-3-methoxybenzoate, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate (trade name "TINUVIN 120", manufactured by BASF Corporation ) and the like.

Cyanoacrylate-based UV absorbers (cyanoacrylate-based compounds) include, for example, alkyl 2-cyanoacrylates, cycloalkyl 2-cyanoacrylates, alkoxyalkyl 2-cyanoacrylates, alkenyl 2-cyanoacrylates, alkynyl 2-cyanoacrylates, and the like. mentioned.

As the UV absorber, a benzotriazole-based UV-absorbing agent has high UV-absorbing properties, excellent optical properties, ease of obtaining a pressure-sensitive adhesive layer having high transparency, and excellent photostability. At least one UV absorber selected from the group consisting of benzophenone-based UV absorbers, benzophenone-based UV absorbers, and hydroxyphenyltriazine-based UV absorbers is preferred, and benzotriazole-based UV absorbers and benzophenone-based UV absorbers are more preferred. In particular, a benzotriazole-based ultraviolet absorber in which a phenyl group having a group having 6 or more carbon atoms and a hydroxyl group as a substituent is bonded to a nitrogen atom constituting a benzotriazole ring is preferred. Moreover, from the viewpoint of preventing deterioration of the appearance due to precipitation of the ultraviolet absorber, it is preferable to use a liquid ultraviolet absorber or two or more kinds of ultraviolet absorbers.

In order to obtain higher ultraviolet absorption, the ultraviolet absorber preferably has an absorbance A of 0.5 or less, which is determined below.
Absorbance A: Absorbance measured by applying light with a wavelength of 400 nm to a 0.08% toluene solution of the ultraviolet absorber

When the pressure-sensitive adhesive layer of the present invention contains an ultraviolet absorber, the content of the ultraviolet absorber in the pressure-sensitive adhesive layer (especially acrylic pressure-sensitive adhesive layer) of the present invention is not particularly limited, but is included in external light. From the viewpoint of suppressing deterioration of the OLED element due to ultraviolet rays and obtaining an OLED display device with excellent weather resistance without using a polarizing plate, it is preferably 0.01 part by weight or more with respect to 100 parts by weight of the acrylic polymer. , more preferably 0.05 parts by weight or more, and still more preferably 0.1 parts by weight or more. In addition, the upper limit of the content of the ultraviolet absorber is to suppress the occurrence of yellowing of the pressure-sensitive adhesive due to the addition of the ultraviolet absorber, and to obtain excellent optical properties, high transparency, and excellent appearance properties. More preferably, it is 20 parts by weight or less, more preferably 10 parts by weight or less, and even more preferably 8 parts by weight or less with respect to 100 parts by weight of the acrylic polymer.

Instead of the ultraviolet absorber, or in combination with the ultraviolet absorber, a dye compound whose absorption spectrum has a maximum absorption wavelength in the wavelength region of 380 to 430 nm can be contained. The dye compound can also suppress deterioration of the OLED element and deterioration of the high refractive index component due to ultraviolet light.

The dye compounds may be used singly or in combination of two or more. When only the colorant compound is used, the content of the colorant compound as a whole is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the base polymer (eg, acrylic polymer). It is preferably 1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight. By setting the amount of the dye compound added in the above range, it is possible to sufficiently absorb light in a region that does not affect the light emission of the OLED element. This is preferable because deterioration of the element and deterioration of the high refractive index component can be suppressed.

Either one of the ultraviolet absorber and the dye compound can be used, but it is preferable to use the ultraviolet absorber and the dye compound together. According to the ultraviolet absorber, for example, although it can absorb light with a wavelength of 380 nm, the light in the wavelength region (380 nm to 430 nm) on the shorter wavelength side than the light emitting region (longer wavelength side than 430 nm) of the OLED element is sufficient. is not absorbed by the transmitted light, and deterioration may occur due to the transmitted light. The dye compound can suppress the transmission of light with a wavelength (380 nm to 430 nm) on the shorter wavelength side than the light emitting region (longer wavelength side than 430 nm) of the OLED element, and the ultraviolet absorber and the dye compound are used in combination. As a result, a sufficient visible light transmittance can be ensured in the light emitting region of the OLED element.
In the present invention, by using such a dye compound and the ultraviolet absorber in combination, it is possible to sufficiently absorb light in a region (wavelength 380 nm to 430 nm) that does not affect the light emission of the OLED element, and the OLED The light-emitting region of the element (on the longer wavelength side than 430 nm) is sufficiently transmissive, and as a result, the deterioration of the OLED element due to external light and the deterioration of the high refractive index component can be suppressed at the same time. When the ultraviolet absorber and the dye compound are used in combination, the ultraviolet absorber is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the base polymer (eg, acrylic polymer). .1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight. The dye compound is preferably about 0.1 to 10 parts by weight, more preferably about 0.1 to 5 parts by weight, with respect to 100 parts by weight of the base polymer (eg, acrylic polymer). It is more preferably 0.5 to 3 parts by weight.

The dye compound is not particularly limited as long as it is a compound whose absorption spectrum has a maximum absorption wavelength in the wavelength range of 380 to 430 nm. The maximum absorption wavelength means the absorption maximum wavelength showing the maximum absorbance among a plurality of absorption maxima in the spectral absorption spectrum in the wavelength region of 300 to 460 nm.

The maximum absorption wavelength of the absorption spectrum of the dye compound is more preferably in the wavelength region of 380-420 nm. The dye compound is not particularly limited as long as it has the wavelength characteristics described above, but a material that does not impair the display properties of the OLED element and does not have fluorescence or phosphorescence (photoluminescence) is preferable.

Examples of the organic dye compounds include azomethine compounds, indole compounds, cinnamic acid compounds, pyrimidine compounds, porphyrin compounds, and cyanine compounds.

As the organic dye compound, commercially available ones can be suitably used. Specifically, as the indole compound, BONASORB UA3911 (trade name, maximum absorption wavelength of absorption spectrum: 398 nm, Orient Chemical Kogyo Co., Ltd.), as a cinnamic acid compound, SOM-5-0106 (trade name, maximum absorption wavelength of absorption spectrum: 416 nm, manufactured by Orient Chemical Industry Co., Ltd.), and as a porphyrin compound, FDB-001 (trade name, maximum absorption wavelength of absorption spectrum: 420 nm, manufactured by Yamada Chemical Industry Co., Ltd.), and a merocyanine compound (trade name: FDB-009, maximum absorption wavelength of absorption spectrum: 394 nm) as a cyanine compound , manufactured by Yamada Chemical Industry Co., Ltd.), polymethine compounds (trade name: DAA-247, maximum absorption wavelength of absorption spectrum: 389 nm, manufactured by Yamada Chemical Industry Co., Ltd.). From the viewpoint of optical reliability, the cyanine compounds are preferred, and polymethine compounds are particularly preferred.

The adhesive layer of the present invention may contain a light stabilizer. When the pressure-sensitive adhesive layer of the present invention contains a light stabilizer, it is particularly preferable to contain the light stabilizer together with the ultraviolet absorber. The light stabilizer can scavenge radicals generated by photo-oxidation, and thus can improve the resistance of the pressure-sensitive adhesive layer to light (especially ultraviolet rays). In addition, a light stabilizer can be used individually or in combination of 2 or more types.

Examples of the light stabilizer include, but are not limited to, phenol light stabilizers (phenol compounds), phosphorus light stabilizers (phosphorus compounds), thioether light stabilizers (thioether compounds), amine light stabilizers, Stabilizers (amine compounds) (especially hindered amine stabilizers (hindered amine compounds)) and the like.

Examples of the phenolic light stabilizer (phenolic compound) include 2,6-di-tertiary-butyl-4-methylphenol, 4-hydroxymethyl-2,6-di-tertiary-butylphenol, 2, 6-di-tertiary-butyl-4-ethylphenol, butylated hydroxyanisole, n-octadecyl 3-(4-hydroxy-3,5-di-tertiary-butylphenyl) propionate, distearyl (4-hydroxy- 3-methyl-5-tertiary-butyl)benzylmalonate, tocopherol, 2,2′-methylenebis(4-methyl-6-tertiary-butylphenol), 2,2′-methylenebis(4-ethyl-6-tertiary tertiary butylphenol), 4,4'-methylenebis (2,6-di-tertiary butylphenol), 4,4'-butylidenebis (6-tertiary butyl-m-cresol), 4,4'-thiobis ( 6-tertiary-butyl-m-cresol), styrenated phenol, N,N'-hexamethylenebis(3,5-di-tertiary-butyl-4-hydroxyhydrocinnamide, bis(3,5-di -tert-butyl-4-hydroxybenzylphosphonic acid ethyl ester) calcium, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl -2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy methyl]methane, 1,6-hexanediol-bis[3-(3,5-di-tertiary-butyl-4-hydroxyphenyl)propionate], 2,2′-methylenebis(4-methyl-6-cyclohexylphenol ), 2,2′-methylenebis[6-(1-methylcyclohexyl)-p-cresol], 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate acid, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid, triethylene glycol-bis[3-(3-tert-butyl-4-hydroxy-5 -methylphenyl)propionate], 2,2′-oxamide bis[ethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 6-(4-hydroxy-3,5-di- tert-butylanilino)-2,4-dioctylthio-1,3,5-triazine, bis[2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5- methylbenzyl)phenyl]terephthalate, 3,9-bis{2-[3-(3-tertiary-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4 , 8,10-tetraoxaspiro[5.5]undecane, 3,9-bis{2-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]-1,1 -dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane and the like.

Phosphorus-based light stabilizers (phosphorus-based compounds) include, for example, trisnonylphenyl phosphite, tris(2,4-di-tertiary-butylphenyl)phosphite, tris[2-tertiary-butyl-4-( 3-tertiary-butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl]phosphite, tridecylphosphite, octyldiphenylphosphite, di(decyl)monophenylphosphite, di(tridecyl)penta Erythritol diphosphite, distearyl pentaerythritol diphosphite, di(nonylphenyl) pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6- Di-tertiary-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tri-tertiary-butylphenyl)pentaerythritol diphosphite, tetra(tridecyl)isopropylidenediphenol diphosphite phyte, tetra(tridecyl)-4,4'-n-butylidenebis(2-tertiary-butyl-5-methylphenol) diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy -5-tertiary-butylphenyl)butanetriphosphite, tetrakis(2,4-di-tertiary-butylphenyl)biphenylenediphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene- 10-oxide, tris(2-[(2,4,8,10-tetrakis-tertiary-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl ) amines and the like.

Thioether-based light stabilizers (thioether-based compounds) include, for example, dilauryl thiodipropionate, dimyristyl, dialkylthiodipropionate compounds such as distearyl; polyol β such as tetrakis[methylene(3-dodecylthio)propionate]methane; -alkylmercaptopropionate ester compounds, and the like.

Examples of amine-based light stabilizers (amine-based compounds) include polymers of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol (trade name "TINUVIN 622", BASF Co.), a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol and N,N',N'',N'''-tetrakis-(4, 6-bis-(butyl-(N-methyl-2,2,6,6-tetramethylpiperidin-4-yl)amino)-triazin-2-yl)-4,7-diazadecane-1,10-diamine and 1:1 reaction product (trade name "TINUVIN 119", manufactured by BASF), dibutylamine 1,3-triazine N,N'-bis(2,2,6,6-tetramethyl-4- Polycondensate of piperidyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine (trade name “TINUVIN 2020”, manufactured by BASF), poly[{6 -(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2-4-diyl}{2,2,6,6-tetramethyl-4-piperidyl}imino]hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl)imino} (trade name "TINUVIN 944", manufactured by BASF), bis(1,2,2,6,6-pentamethyl-4-piperidyl) A mixture of sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (trade name "TINUVIN 765", manufactured by BASF), bis(2,2,6,6-tetramethyl-4- piperidyl) sebacate (trade name "TINUVIN 770", manufactured by BASF), decanedioic acid bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester, 1,1-dimethyl Reaction product of ethyl hydroperoxide and octane (trade name "TINUVIN 123", manufactured by BASF), bis(1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis(1, 1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate (trade name "TINUVIN 144", manufactured by BASF), cyclohexane and N-butyl peroxide 2,2,6,6-tetramethyl-4-piperidine Reaction product of amine-2,4,6-trichloro-1,3,5-triazine and 2-aminoethanol (trade name “TINUVIN 152” manufactured by BASF), bis(1,2, A mixture of 2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (trade name "TINUVIN 292", manufactured by BASF), 1,2 , 3,4-butanetetracarboxylic acid with 1,2,2,6,6-pentamethyl-4-piperidinol and 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8, A mixed ester with 10-tetraoxaspiro[5.5]undecane (trade name “ADEKA STAB LA-63P”, manufactured by ADEKA Co., Ltd.) and the like can be mentioned. As the amine stabilizer, a hindered amine stabilizer is particularly preferred.

When the pressure-sensitive adhesive layer of the present invention contains a light stabilizer, the content of the light stabilizer in the pressure-sensitive adhesive layer of the present invention (particularly, the acrylic pressure-sensitive adhesive layer) is not particularly limited, but resistance to light is improved. From the viewpoint of facilitating expression, it is preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight or more, relative to 100 parts by weight of the acrylic polymer. In addition, the upper limit of the content is 5 parts by weight or less with respect to 100 parts by weight of the acrylic polymer, from the viewpoints that coloring due to the light stabilizer itself is unlikely to occur, high transparency can be easily obtained, and optical properties. is preferably 3 parts by weight or less.

Although not particularly limited, a cross-linking agent may be used to form the pressure-sensitive adhesive layer of the present invention. For example, the gel fraction can be controlled by cross-linking the acrylic polymer in the acrylic pressure-sensitive adhesive layer. In addition, a crosslinking agent can be used individually or in combination of 2 or more types.

The cross-linking agent is not particularly limited. cross-linking agents, metal salt-based cross-linking agents, carbodiimide-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, and amine-based cross-linking agents. Among them, isocyanate-based cross-linking agents and epoxy-based cross-linking agents are preferable, and isocyanate-based cross-linking agents are more preferable.

Examples of the isocyanate-based cross-linking agent (polyfunctional isocyanate compound) include lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; cyclopentylene diisocyanate; , cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate and other alicyclic polyisocyanates; 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate and aromatic polyisocyanates such as xylylene diisocyanate. Examples of the isocyanate-based cross-linking agent include trimethylolpropane/tolylene diisocyanate adduct (trade name “Coronate L”, manufactured by Tosoh Corporation), trimethylolpropane/hexamethylene diisocyanate adduct (trade name “Coronate HL", manufactured by Tosoh Corporation), trimethylolpropane/xylylene diisocyanate adduct (trade name "Takenate D-110N", manufactured by Mitsui Chemicals, Inc.).

Examples of the epoxy-based cross-linking agent (polyfunctional epoxy compound) include N,N,N',N'-tetraglycidyl-m-xylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidyl aminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether , glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipate diglycidyl ester, o-phthalate diglycidyl ester, triglycidyl-tris(2 -hydroxyethyl)isocyanurate, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy resins having two or more epoxy groups in the molecule. Examples of the epoxy-based cross-linking agent include commercially available products such as the trade name "Tetrad C" (manufactured by Mitsubishi Gas Chemical Company, Inc.).

When a cross-linking agent is used to form the pressure-sensitive adhesive layer of the present invention, the amount of the cross-linking agent used is not particularly limited. 001 parts by weight or more, more preferably 0.01 parts by weight or more. In addition, the upper limit of the amount used is preferably 10 parts by weight or less with respect to 100 parts by weight of the base polymer, more preferably 10 parts by weight or less, from the viewpoint of obtaining appropriate flexibility in the pressure-sensitive adhesive layer and improving the adhesive strength. is 5 parts by weight or less.

The pressure-sensitive adhesive layer (especially acrylic pressure-sensitive adhesive layer) of the present invention contains a silane coupling agent in order to improve adhesion reliability under humidified conditions, particularly to improve adhesion reliability to glass. may In addition, a silane coupling agent can be used individually or in combination of 2 or more types. When the pressure-sensitive adhesive layer contains a silane coupling agent, the adhesiveness under humidified conditions, particularly the adhesiveness to glass, can be improved.

Examples of the silane coupling agent include, but are not limited to, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-aminopropyltrimethoxysilane, methoxysilane and the like. Furthermore, as the silane coupling agent, for example, commercially available products such as the trade name "KBM-403" (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be mentioned. Among them, γ-glycidoxypropyltrimethoxysilane is preferable as the silane coupling agent.

When the pressure-sensitive adhesive layer of the present invention contains a silane coupling agent, the content of the silane coupling agent in the pressure-sensitive adhesive layer (particularly, acrylic pressure-sensitive adhesive layer) of the present invention is not particularly limited, but the It is preferably 0.01 parts by weight or more, more preferably 0.02 parts by weight or more, relative to 100 parts by weight of the base polymer. The upper limit of the content of the silane coupling agent is preferably 10 parts by weight or less, more preferably 1 part by weight or less, relative to 100 parts by weight of the base polymer.

The pressure-sensitive adhesive layer of the present invention may optionally further contain a cross-linking accelerator, a tackifying resin (rosin derivative, polyterpene resin, petroleum resin, oil-soluble phenol, etc.), an antioxidant, a filler, a coloring agent (pigment or Dyes, etc.), antioxidants, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents, and the like may be contained within the range that does not impair the effects of the present invention. Such additives can be used alone or in combination of two or more.

The method for producing the pressure-sensitive adhesive layer (particularly, the acrylic pressure-sensitive adhesive layer) of the present invention is not particularly limited. and drying and curing the resulting adhesive composition layer, or coating (coating) the adhesive composition on a substrate (including a resin layer and a glass layer described later) or a release liner (coating process) and irradiating the obtained pressure-sensitive adhesive composition layer with an active energy ray to cure it. Moreover, you may heat-dry further as needed.

Examples of the active energy rays include ionizing radiation such as α-rays, β-rays, γ-rays, neutron beams and electron beams, and ultraviolet rays, with ultraviolet rays being particularly preferred. Moreover, the irradiation energy of the active energy ray, the irradiation time, the irradiation method, etc. are not particularly limited.

The adhesive composition can be produced by a known or commonly used method. For example, a solvent-based acrylic pressure-sensitive adhesive composition can be prepared by mixing an additive (for example, an ultraviolet absorber, etc.) with a solution containing the acrylic polymer, if necessary. For example, an active energy ray-curable acrylic pressure-sensitive adhesive composition can be prepared by mixing an additive (for example, an ultraviolet absorber, etc.) with the acrylic monomer mixture or its partial polymer, if necessary. can be made.

A known coating method may be used for applying (coating) the pressure-sensitive adhesive composition. For example, coaters such as gravure roll coaters, reverse roll coaters, kiss roll coaters, dip roll coaters, bar coaters, knife coaters, spray coaters, comma coaters and direct coaters may be used.

In particular, when the adhesive layer is formed from an active energy ray-curable adhesive composition, the active energy ray-curable adhesive composition preferably contains a photopolymerization initiator. When the active energy ray-curable pressure-sensitive adhesive composition contains an ultraviolet absorber, it preferably contains at least a photopolymerization initiator having light absorption properties in a wide wavelength range as a photopolymerization initiator. For example, it preferably contains at least a photopolymerization initiator that absorbs not only ultraviolet light but also visible light. This is because there is concern that curing by active energy rays may be inhibited due to the action of the ultraviolet absorber, and if the adhesive composition contains a photopolymerization initiator that has light absorption characteristics in a wide wavelength range, high photocurability will be achieved in the adhesive composition. This is because it becomes easier to obtain.

(adhesive layer)
An adhesive layer is a layer that can bind substances by being interposed between adherends. It means something that does not have

Various adhesives can be applied as the adhesive for forming the adhesive layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "adhesive layer of the present invention"). , polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, water-based polyesters, and the like. These adhesives are usually used as adhesives consisting of an aqueous solution (water-based adhesives) and contain 0.5 to 60% by weight of solids. Among these, polyvinyl alcohol-based adhesives are preferable, and acetoacetyl group-containing polyvinyl alcohol-based adhesives are more preferable.

The water-based adhesive may contain a cross-linking agent. As the cross-linking agent, a compound having at least two functional groups in one molecule that are reactive with components such as polymers constituting the adhesive is usually used. Examples include alkylenediamines; isocyanates; epoxies; Aldehydes: amino-formaldehydes such as methylol urea and methylol melamine. The amount of the cross-linking agent compounded in the adhesive is usually about 10 to 60 parts by weight per 100 parts by weight of components such as polymers constituting the adhesive.

In addition to the above, examples of the adhesive include active energy ray-curable adhesives such as ultraviolet-curable adhesives and electron beam-curable adhesives. Examples of the active energy ray-curable adhesive include (meth)acrylate adhesives. Examples of the curable component in the (meth)acrylate adhesive include a compound having a (meth)acryloyl group and a compound having a vinyl group. Examples of compounds having a (meth)acryloyl group include alkyl (meth)acrylates having 1 to 20 carbon atoms, chain alkyl (meth)acrylates, alicyclic alkyl (meth)acrylates, and polycyclic alkyl (meth)acrylates. ) acrylates; hydroxyl group-containing (meth)acrylates; and epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate. (Meth)acrylate adhesives include hydroxyethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, (meth)acrylamide, (meth) Nitrogen-containing monomers such as acryloylmorpholine may also be included. (Meth)acrylate-based adhesives include tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecanedimethanol diacrylate, cyclic trimethylolpropane formal acrylate, dioxane glycol diacrylate, and EO as crosslinking components. Polyfunctional monomers such as modified diglycerin tetraacrylate may be included. A compound having an epoxy group or an oxetanyl group can also be used as a cationic polymerization-curable adhesive. The compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various commonly known curable epoxy compounds can be used.

The adhesive may contain appropriate additives as necessary. Examples of the additives include silane coupling agents, coupling agents such as titanium coupling agents, adhesion promoters such as ethylene oxide, ultraviolet absorbers, deterioration inhibitors, dyes, processing aids, ion trapping agents, and antioxidants. agents, tackifiers, fillers, plasticizers, leveling agents, foaming inhibitors, antistatic agents, heat stabilizers, hydrolysis stabilizers, and the like.

The adhesive may be applied to either one of the two adherends to be adhered, or to both. After lamination, a drying step can be performed to form the adhesive layer of the present invention consisting of a coated dry layer. After the drying step, ultraviolet rays or electron beams can be applied, if necessary. The thickness of the adhesive layer of the present invention is not particularly limited. When using adhesives, electron beam curing adhesives, etc., the thickness is preferably about 0.1 to 100 μm, more preferably about 0.5 to 10 μm.

When the indentation elastic modulus of the adhesive layer of the present invention is Ea, the indentation elastic modulus Ea is preferably 1 GPa or more, more preferably 2 GPa or more, and still more preferably 3 GPa or more. When the indentation elastic modulus Ea is 1 GPa or more, impact resistance is further improved. The indentation elastic modulus Ea is, for example, 50 GPa or less, and may be 30 GPa or less, or 10 GPa or less.

The indentation modulus Ea can be measured based on the nanoindenter method. The above nanoindenter method is measured under the conditions of a spherical indenter (curvature radius of 10 μm), a temperature of 25°C, and an indentation depth of 100 nm.

(resin layer)
The resin layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "resin layer of the present invention") is not particularly limited, but examples thereof include plastic films. Materials for the plastic film include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); ), trade name “Zeonor” (manufactured by Nippon Zeon Co., Ltd.), etc.), acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate (PC), triacetyl cellulose (TAC), polysulfone, polyarylate, polyether ether Plastic materials such as ketone (PEEK), polyimide (PI), transparent polyimide (CPI), polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, ethylene-propylene copolymer, etc., have excellent dimensional stability and are resistant to shrinkage. Polyethylene terephthalate (PET), polyester resins such as polyethylene naphthalate (PEN), cyclic olefin polymers (COP), polycarbonate (PC), polyether ether ketone (PEEK), and transparent polyimide (CPI) are preferred, and polyethylene terephthalate is preferred. (PET) and transparent polyimide (CPI) are more preferable, and transparent polyimide (CPI), which is excellent in impact resistance, is particularly preferable. In addition, these plastic materials can be used individually or in combination of 2 or more types. The "resin layer" does not include a release liner that is peeled off when the optical element of the present invention is used (attached).

The resin layer of the present invention is preferably transparent. The total light transmittance (according to JIS K 7361-1) of the resin layer of the present invention in the visible light wavelength region is not particularly limited, but is preferably 85% or more, more preferably 88% or more. In addition, the haze (according to JIS K 7136) of the resin layer of the present invention is not particularly limited, but is preferably 1.5% or less, more preferably 1.0% or less.

In the present invention, the difference in refractive index between the pressure-sensitive adhesive (the pressure-sensitive adhesive layer excluding the light-scattering fine particles in the pressure-sensitive adhesive layer) and the resin layer ("refractive index of pressure-sensitive adhesive" - "refractive index of resin layer") is Although it is not particularly limited, it is preferably 2 or less, preferably 1 or less, more preferably 0.5 or less, and particularly preferably 0.5 or less, from the viewpoint of improving the interface antireflection property and improving the lighting rate of light from the OLED element. 3 or less.

Although the thickness of the resin layer of the present invention is not particularly limited, it is preferably 10 to 80 μm, for example. In addition, the resin layer of the present invention may have either a single layer structure or a multilayer structure. In addition, the surface of the resin layer of the present invention may be appropriately subjected to known and commonly used surface treatments such as physical treatments such as corona discharge treatment and plasma treatment, and chemical treatments such as undercoating treatment.

Although the resin layer of the present invention is not particularly limited, it preferably contains an ultraviolet absorber (UVA) or a dye compound having a maximum absorption wavelength in the absorption spectrum of 380 to 430 nm. When the resin layer of the present invention contains an ultraviolet absorber or the dye compound, deterioration of the OLED element due to ultraviolet rays contained in external light is suppressed, and an OLED display device having excellent weather resistance can be obtained without using a polarizing plate. can. In addition, deterioration of the high refractive index component of the pressure-sensitive adhesive layer due to ultraviolet rays can be suppressed, and a high lighting rate can be maintained. In particular, when the resin layer of the present invention contains the ultraviolet absorber and the dye compound, the content of the ultraviolet absorber and the dye compound in the pressure-sensitive adhesive layer of the present invention can be reduced. Precipitation and bleeding out of the ultraviolet absorber and the dye compound in the inside can be suppressed, which is preferable.

As the ultraviolet absorber (UVA) and dye compound contained in the resin layer of the present invention, the same ultraviolet absorber and dye compound contained in the pressure-sensitive adhesive layer of the present invention can be used. In addition, the ultraviolet absorber and the dye compound can be used alone or in combination of two or more.

When the resin layer of the present invention contains an ultraviolet absorber or the dye compound, the content of each of the ultraviolet absorber and the dye compound in the resin layer of the present invention is not particularly limited, but is included in external light. From the viewpoint of suppressing deterioration of the OLED element due to ultraviolet rays and obtaining an OLED display device with excellent weather resistance without using a polarizing plate, it is preferably 0.01 part by weight or more with respect to 100 parts by weight of the resin layer, It is more preferably 0.05 parts by weight or more, and still more preferably 0.1 parts by weight or more. In addition, the upper limit of the content of the ultraviolet absorber and the dye compound suppresses the occurrence of yellowing of the adhesive due to the addition of the ultraviolet absorber, and provides excellent optical properties, high transparency, and excellent appearance. From the viewpoint of obtaining properties, it is preferably 10 parts by weight or less, more preferably 9 parts by weight or less, and even more preferably 8 parts by weight or less with respect to 100 parts by weight of the resin layer.

When both the resin layer and the pressure-sensitive adhesive layer of the present invention contain an ultraviolet absorber or the dye compound, the total amount may be adjusted to fall within the above range.

The moisture permeability of the resin layer of the present invention is not particularly limited. more preferably 40 g/m ² ·24h or more, still more preferably 100 g/m ² ·24h or more, and particularly preferably 200 g/m ² ·24h or more. Although the upper limit of the moisture permeability of the resin layer of the present invention is not particularly limited, it may be 1200 g/m ² ·24 h or less from the viewpoint of suppressing swelling under humidification. Since the resin layer of the present invention has a high moisture permeability, there is a tendency that the reliability of daylighting is improved.
The moisture permeability of the resin layer of the present invention can be measured in accordance with JIS Z0208 under an environment of a temperature of 40° C. and a relative humidity of 92%, and can be adjusted by the type and thickness of the resin constituting the resin layer of the present invention. can be done.

(glass layer)
The glass layer constituting the optical element of the present invention (hereinafter sometimes referred to as "the glass layer of the present invention") is not particularly limited, and suitable layers can be adopted depending on the purpose. Examples of the glass layer of the present invention include soda-lime glass, boric acid glass, aluminosilicate glass, quartz glass, etc. according to classification according to composition. Moreover, according to the classification by the alkali component, non-alkali glass and low-alkali glass can be mentioned. The content of alkali metal components (eg, Na ₂ O, K ₂ O, Li ₂ O) in the glass is preferably 15% by weight or less, more preferably 10% by weight or less.

The thickness of the glass layer of the present invention is preferably 20 μm or more, considering the surface hardness, airtightness, and corrosion resistance of the glass. In addition, the glass layer of the present invention desirably has film-like flexibility and bendability, and suppresses the image from being doubled so that a clear image can be projected. A thickness of 60 μm or less is preferable. The thickness of the glass layer of the present invention is more preferably 30 μm or more and 55 μm or less, and particularly preferably 40 μm or more and 50 μm or less.

The light transmittance of the glass layer of the present invention at a wavelength of 550 nm is preferably 85% or more. The refractive index of the glass layer of the present invention at a wavelength of 550 nm is preferably 1.4 to 1.65. The density of the glass layer of the present invention is preferably 2.3 g/cm ³ to 3.0 g/cm ³ , more preferably 2.3 g/cm ³ to 2.7 g/cm ³ .

The method for forming the glass layer of the present invention is not particularly limited, and an appropriate method can be adopted depending on the purpose. Typically, the glass layer of the present invention is prepared by heating a mixture containing a main raw material such as silica or alumina, an antifoaming agent such as mirabilite or antimony oxide, and a reducing agent such as carbon at a temperature of about 1400°C to 1600°C. It can be produced by melting at a high temperature, molding it into a thin plate, and then cooling it. Examples of the method for forming the glass layer of the present invention include a slot down draw method, a fusion method, a float method and the like. The glass layer formed into a plate shape by these methods may be chemically polished with a solvent such as hydrofluoric acid, if necessary, in order to thin the plate or improve smoothness.

(Hard coat layer)
The hard coat layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "hard coat layer of the present invention") has sufficient surface hardness, excellent mechanical strength, and excellent light transmittance. , may be formed from any suitable resin. Specific examples of resins include thermosetting resins, thermoplastic resins, ultraviolet curing resins, electron beam curing resins, and two-liquid mixed resins. A UV curable resin is preferred. This is because the hard coat layer can be formed with simple operation and high efficiency.

Specific examples of UV-curable resins include polyester-based, acrylic-based, urethane-based, amide-based, silicone-based, and epoxy-based UV-curable resins. UV-curable resins include UV-curable monomers, oligomers, and polymers. Preferred UV-curable resins include resin compositions containing acrylic monomer or oligomer components having preferably 2 or more, more preferably 3 to 6, UV-polymerizable functional groups. Typically, the UV curable resin contains a photopolymerization initiator.

The hard coat layer of the present invention can be formed by any appropriate method. For example, the hard coat layer of the present invention is formed by coating a resin composition for forming a hard coat layer on a substrate (including the resin layer and the glass layer), drying the coating, and irradiating the dried coating film with ultraviolet rays. can be formed by curing with

The thickness of the hard coat layer of the present invention is, for example, 2-20 μm, preferably 4-15 μm, more preferably 4-10 μm.

The water contact angle of the hard coat layer of the present invention is preferably 95° or more, more preferably 100° or more, still more preferably 105° or more, from the viewpoint of antifouling properties.
The water contact angle of the hard coat layer of the present invention is measured according to JIS R3257, and can be adjusted depending on the type of resin constituting the hard coat layer, curing conditions, and the like. Further, the hard coat layer of the present invention preferably has a water contact angle within the above range after the steel wool test described below.
<Steel wool test>
A 1 cm square piece of steel wool "product number #0000" manufactured by Trusco Co., Ltd. is cut, and the surface of the hard coat layer is rubbed 1,000 times under the conditions of a load of 1 kg and a moving speed of 100 mm/sec.

The Vickers hardness of the hard coat layer of the present invention is preferably 80 or higher, more preferably 90 or higher, still more preferably 100 or higher, from the viewpoint of excellent surface hardness and scratch resistance.
The Vickers hardness of the hard coat layer of the present invention is measured according to JIS Z2244, and can be adjusted depending on the type of resin constituting the hard coat layer, curing conditions, and the like.

The surface element ratio of carbon elements on the surface of the hard coat layer of the present invention is 50 atomic % or less, preferably 45 atomic % or less, from the viewpoint of antifouling properties, and the fluorine element ratio on the surface of the hard coat layer is 30 atomic % or more. be.
Further, the nitrogen element ratio on the surface of the hard coat layer is, for example, less than 1.5 atomic %, preferably 1.3 atomic % or less, and is, for example, 0 atomic % or more.
The surface element ratio of fluorine element, carbon element, and nitrogen element on the surface of the hard coat layer of the present invention can be measured by X-ray photoelectron spectroscopy, and the type of resin constituting the hard coat layer, curing conditions, etc. can be adjusted by

(Antireflection layer)
The antireflection layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "antireflection layer of the present invention") is preferably composed of an inorganic material. Examples of the above-mentioned inorganic substances include inorganic substances exemplified and explained as materials for forming the high refractive index layer, the low refractive index layer, and the medium refractive index layer, which will be described later.

Any appropriate structure can be adopted as the antireflection layer of the present invention. (ii) a laminate having a medium refractive index layer, a high refractive index layer and a low refractive index layer in this order;

Materials that can form the low refractive index layer include, for example, silicon oxide (SiO ₂ ) and magnesium fluoride (MgF ₂ ). The refractive index of the low refractive index layer is typically about 1.35 to 1.55.

The material of the low refractive index layer may be a cured product of a curable fluorine-containing resin. A curable fluorine-containing resin has, for example, structural units derived from a fluorine-containing monomer and structural units derived from a crosslinkable monomer. Specific examples of fluorine-containing monomers include fluoroolefins (fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole, etc.). , partially or completely fluorinated alkyl group (meth) acrylic acid ester derivatives (Viscoat 6FM (manufactured by Osaka Organic Chemical Co., Ltd.), M-2020 (manufactured by Daikin), etc.), completely or partially fluorinated vinyl ethers and the like. Examples of crosslinkable monomers include (meth)acrylate monomers having crosslinkable functional groups in the molecule such as glycidyl methacrylate; (meth)acrylate monomers having functional groups such as carboxyl groups, hydroxyl groups, amino groups and sulfonic acid groups. ((meth)acrylic acid, methylol (meth)acrylate, hydroxyalkyl (meth)acrylate, allyl (meth)acrylate, etc.). The fluorine-containing resin may have constitutional units derived from monomers other than the compounds described above (for example, olefin-based monomers, (meth)acrylate-based monomers, and styrene-based monomers).

Materials capable of forming the high refractive index layer include, for example, titanium oxide (TiO ₂ ), niobium oxide (Nb ₂ O ₃ or Nb ₂ O ₅ ), tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), ZrO ₂ --TiO ₂ can be mentioned. The refractive index of the high refractive index layer is typically about 1.60 to 2.40.

Materials capable of forming the medium refractive index layer include, for example, titanium oxide (TiO ₂ ), a mixture of a material capable of forming a low refractive index layer and a material capable of forming a high refractive index layer (for example, titanium oxide and oxide mixtures with silicon). The refractive index of the medium refractive index layer is typically about 1.50 to 1.85. The thicknesses of the low refractive index layer, the medium refractive index layer, and the high refractive index layer can be set so as to realize an appropriate optical film thickness according to the layer structure of the antireflection layer, desired antireflection performance, and the like.

The antireflection layer of the present invention may be formed by a dry process (e.g., sputtering), may be formed by a wet process (e.g., coating), or may be formed by combining a dry process and a wet process. . Specific examples of the dry process include a PVD (Physical Vapor Deposition) method and a CVD (Chemical Vapor Deposition) method. PVD methods include vacuum vapor deposition, reactive vapor deposition, ion beam assist, sputtering, and ion plating. As the CVD method, there is a plasma CVD method.

As a specific example of the wet process, for example, a coating liquid for forming an antireflection layer can be applied to form a coating film, and the coating film can be cured to form an antireflection layer. Examples of coating methods that can be used include fountain coating, die coating, spin coating, spray coating, gravure coating, roll coating, and bar coating. It is preferable to dry the coating film prior to the curing. The drying may be, for example, natural drying, air drying by blowing air, heat drying, or a combination thereof. Curing means for the coating film is not particularly limited, but UV curing is preferred.

The thickness of the antireflection layer of the present invention is, for example, about 20 nm to 300 nm.

The antireflection layer of the present invention preferably has a water contact angle of 90° or more, more preferably 95° or more, still more preferably 100° or more, and particularly preferably 105° or more, from the viewpoint of antifouling properties.
The water contact angle of the antireflection layer of the invention is measured according to JIS R3257, and can be adjusted depending on the types of components constituting the antireflection layer. Further, the antireflection layer of the present invention preferably has a water contact angle within the above range after the following eraser test. By laminating an antireflection layer having a water contact angle within these ranges after the eraser test on the viewing side of the OLED display device, especially on the outermost surface, even after the OLED display device is rubbed with a human hand or cloth, Excellent antifouling property can be maintained.
<Eraser test>
Abrasion resistance evaluation eraser "Product No. 4004005007" manufactured by Minoan was cut into 7 mm pieces, and the surface of the hard coat layer was rubbed 6000 times under the conditions of a load of 1 kg and a moving speed of 32 mm/sec.

(Antiglare layer)
As the antiglare layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "antiglare layer of the present invention"), known ones can be employed without limitation. It is formed as a layer in which inorganic or organic particles are dispersed as an antiglare agent.

The antiglare layer of the present invention is not particularly limited. , convex portions are formed on the surface of the antiglare layer of the present invention. With this configuration, the antiglare layer has excellent display characteristics that achieve both antiglare properties and prevention of white blurring. It is possible to prevent the occurrence of protrusions on the surface of the anti-glare layer, which would be a defect in appearance, and improve the yield of the product.

Examples of the resin include thermosetting resins and ionizing radiation curable resins that are cured by ultraviolet light or light. As the resin, it is possible to use a commercially available thermosetting resin, ultraviolet curable resin, or the like.

As the thermosetting resin or UV-curable resin, for example, a curable compound having at least one of an acrylate group and a methacrylate group that is cured by heat, light (ultraviolet rays, etc.), electron beams, or the like can be used. Silicone resins, polyester resins, polyether resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, oligomers or prepolymers such as acrylates and methacrylates of polyfunctional compounds such as polyhydric alcohols. can give. These may be used individually by 1 type, and may use 2 or more types together.

For the resin, for example, a reactive diluent having at least one of an acrylate group and a methacrylate group can be used. As the reactive diluent, for example, reactive diluents described in JP-A-2008-88309 can be used, and examples include monofunctional acrylates, monofunctional methacrylates, polyfunctional acrylates, polyfunctional methacrylates, and the like. As the reactive diluent, tri- or more functional acrylates and tri- or more functional methacrylates are preferable. This is because the antiglare layer of the present invention can have excellent hardness. Examples of the reactive diluent include butanediol glycerol ether diacrylate, isocyanuric acid acrylate, and isocyanuric acid methacrylate. These may be used individually by 1 type, and may use 2 or more types together.

The resin preferably contains a urethane acrylate resin, more preferably a copolymer of a curable urethane acrylate resin and a polyfunctional acrylate (eg, pentathritol triacrylate).

The main functions of the particles for forming the antiglare layer of the present invention are to make the surface of the antiglare layer to be uneven to impart antiglare properties and to control the haze value of the antiglare layer. and The haze value of the antiglare layer can be designed by controlling the refractive index difference between the particles and the resin. Examples of the particles include inorganic particles and organic particles. The inorganic particles are not particularly limited, and examples include silicon oxide particles, titanium oxide particles, aluminum oxide particles, zinc oxide particles, tin oxide particles, zirconium oxide particles, calcium carbonate particles, barium sulfate particles, talc particles, kaolin particles, Examples include calcium sulfate particles. The organic particles are not particularly limited, and examples include polymethyl methacrylate resin powder (PMMA fine particles), silicone resin powder, polystyrene resin powder, polycarbonate resin powder, acrylic styrene resin powder, benzoguanamine resin powder, melamine resin powder, polyolefin. Examples thereof include resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, polyethylene fluoride resin powder and the like. One type of these inorganic particles and organic particles may be used alone, or two or more types may be used in combination.

The weight average particle size (D) of the particles is preferably within the range of 2.5 to 10 μm. By setting the weight-average particle size of the particles within the above range, for example, the anti-glare property can be further improved and white blurring can be prevented. The weight average particle size of the particles is more preferably in the range of 3-7 μm. The weight-average particle diameter of the particles can be measured, for example, by the Coulter counting method. For example, using a particle size distribution measuring device (trade name: Coulter Multisizer, manufactured by Beckman Coulter, Inc.) using the pore electrical resistance method, the volume of the electrolyte solution corresponding to the volume of the particles when the particles pass through the pores. By measuring the electrical resistance, the number and volume of the particles are measured, and the weight average particle diameter is calculated.

The shape of the particles is not particularly limited, and may be, for example, a substantially spherical bead shape, or an irregular shape such as a powder. They are substantially spherical particles with a ratio of 1.5 or less, most preferably spherical particles.

The proportion of the particles in the antiglare layer of the present invention is preferably in the range of 0.2 to 12 parts by weight, more preferably in the range of 0.5 to 12 parts by weight, with respect to 100 parts by weight of the resin. It is preferably in the range of 1 to 7 parts by weight. By setting it as the said range, for example, it can be more excellent in anti-glare property and can prevent a white blur.

The antiglare layer of the present invention may contain a thixotropy-imparting agent. By containing the thixotropy-imparting agent, the aggregation state of the particles can be easily controlled. Examples of the thixotropy imparting agent for forming the antiglare layer of the present invention include organic clay, polyolefin oxide, modified urea and the like.

The organoclay is preferably an organically treated clay in order to improve the affinity with the resin. Examples of organic clays include layered organic clays. The organic clay may be self-prepared, or a commercially available product may be used. Examples of the commercially available products include Lucentite SAN, Lucentite STN, Lucentite SEN, Lucentite SPN, Somasif ME-100, Somasif MAE, Somasif MTE, Somasif MEE, Somasif MPE (trade names, all of which are manufactured by Co-op Chemical Co., Ltd.). ) manufactured); Organite, Organite D, Organite T (trade names, all manufactured by Hojun Co., Ltd.); Kunipia F, Kunipia G, Kunipia G4 (trade names, manufactured by Kunimine Industry Co., Ltd.); Thixogel VZ, Kraton HT , Clayton 40 (trade name, both manufactured by Rockwood Additives), and the like.

The oxidized polyolefin may be prepared in-house, or a commercially available product may be used. Examples of the commercially available products include Disparlon 4200-20 (trade name, manufactured by Kusumoto Kasei Co., Ltd.) and Flownon SA300 (trade name, manufactured by Kyoeisha Chemical Co., Ltd.).

The modified urea is a reaction product of an isocyanate monomer or its adduct and an organic amine. The modified urea may be self-prepared, or a commercially available product may be used. Examples of the commercial product include BYK410 (manufactured by Big Chemie).

The thixotropy-imparting agents may be used singly or in combination of two or more.

The height of the convex portion from the roughness average line of the antiglare layer of the present invention is preferably less than 0.4 times the thickness of the antiglare layer. More preferably, it is in the range of 0.01 times or more and less than 0.4 times, and still more preferably in the range of 0.01 times or more and less than 0.3 times. If it is within this range, it is possible to suitably prevent the formation of protrusions that would cause defects in appearance on the convex portion. The anti-glare layer of the present invention can make appearance defects less likely to occur by having convex portions with such heights. Here, the height from the average line can be measured, for example, by the method described in JP-A-2017-138620.

The ratio of the thixotropy imparting agent in the antiglare layer of the present invention is preferably in the range of 0.1 to 5 parts by weight, more preferably in the range of 0.2 to 4 parts by weight, with respect to 100 parts by weight of the resin. .

Although the thickness (d') of the antiglare layer of the present invention is not particularly limited, it is preferably in the range of 2 to 12 µm. By setting the thickness (d') of the antiglare layer within the above range, for example, it is possible to prevent curling of the optical layered body of the present invention, and to avoid the problem of reduced productivity such as poor transportability. . Further, when the thickness (d') is within the above range, the weight average particle size (D) of the particles is preferably within the range of 2.5 to 10 µm as described above. When the thickness (d') of the antiglare layer of the present invention and the weight average particle size (D) of the particles are in the above-described combination, the antiglare property can be further improved. The thickness (d') of the antiglare layer of the invention is more preferably in the range of 2 to 10 µm, still more preferably in the range of 3 to 8 µm.

The relationship between the thickness (d') of the antiglare layer of the present invention and the weight average particle diameter (D) of the particles is preferably within the range of 0.3≤D/d'≤0.9. With such a relationship, it is possible to obtain an antiglare layer that is more excellent in antiglare properties, can prevent white blurring, and has no defects in appearance.

The haze value (H') of the antiglare layer of the present invention is not particularly limited, but is preferably 5% or more, more preferably 10% or more, from the viewpoint of efficiently reducing color shift and interference unevenness of the OLED display device. , more preferably 15% or more, particularly preferably 20% or more. Further, from the viewpoint of suppressing image blurring of the OLED display device and displaying high-definition images, the haze value of the antiglare layer of the present invention is preferably 80% or less, more preferably 70% or less, and still more preferably 60%. % or less, particularly preferably 50% or less.

The haze value of the antiglare layer of the present invention can be measured by a method defined by JIS K7136, and is designed by controlling the type and thickness of the antiglare layer and the refractive index difference between the particles and the resin. be able to.

In the antiglare layer of the present invention, projections are formed on the surface of the antiglare layer of the present invention by aggregation of the particles and the thixotropy-imparting agent. In the aggregated portion forming the convex portion, the particles are present in a state in which a plurality of particles are aggregated in the plane direction of the antiglare layer of the present invention. As a result, the convex portion has a gentle shape. Since the antiglare layer of the present invention has convex portions having such a shape, it is possible to prevent white blurring while maintaining antiglare properties, and to make appearance defects less likely to occur. can.

The surface shape of the antiglare layer of the present invention can be arbitrarily designed by controlling the aggregation state of the particles contained in the antiglare layer-forming material. The aggregation state of the particles can be controlled by, for example, the material of the particles (for example, chemically modified state of the particle surface, affinity for solvent or resin, etc.), type of resin (binder) or solvent, combination, and the like. The aggregation state of the particles can be controlled by the thixotropy imparting agent contained in the antiglare layer-forming material of the present invention. As a result, the aggregated state of the particles can be made as described above, and the convex portion can be formed into a smooth shape.

In the antiglare layer of the present invention, it is preferable that the number of appearance defects having a maximum diameter of 200 μm or more is 1 or less per 1 m ² of the antiglare layer. More preferably, it does not have the appearance defect.

In the uneven shape of the antiglare layer surface of the present invention, the average inclination angle θa (°) is preferably in the range of 0.1 to 5.0, more preferably in the range of 0.3 to 4.5. , more preferably in the range of 1.0 to 4.0, and particularly preferably in the range of 1.6 to 4.0. Here, the average tilt angle θa is a value defined by the following formula (1). The average tilt angle θa is, for example, a value measured by the method described in JP-A-2017-138620.
Average tilt angle θa=tan-1Δa (1)

In the above formula (1), Δa is, as shown in the following formula (2), the maximum distance between the apex and valley of adjacent peaks in the reference length L of the roughness curve defined in JIS B0601 (1994 edition). It is a value obtained by dividing the total (h1+h2+h3 . The roughness curve is a curve obtained by removing surface waviness components longer than a predetermined wavelength from the cross-sectional curve with a phase difference compensation type high-pass filter. Further, the cross-sectional curve is a contour that appears at the cut end when the target plane is cut along a plane perpendicular to the target plane.
Δa=(h1+h2+h3...+hn)/L (2)

When θa is within the above range, the antiglare property is more excellent and white blurring can be prevented.

In forming the antiglare layer of the present invention, it is preferable that the prepared antiglare layer forming material (coating solution) exhibits thixotropy, and the Ti value defined below is 1.3 to 3.5. is preferably in the range of , more preferably in the range of 1.3 to 2.8.
Ti value = β1/β2
Here, β1 is the viscosity measured at a shear rate of 20 (1/s) using HAAKE's Rheostress 6000, and β2 is the viscosity measured using HAAKE's Rheostress 6000 at a shear rate of 200 (1/s). Viscosity measured under conditions.

If the Ti value is less than 1.3, defects in appearance tend to occur, and the properties of antiglare properties and white blur deteriorate. On the other hand, when the Ti value exceeds 3.5, the particles are less likely to agglomerate and more likely to be in a dispersed state.

The method for producing the antiglare layer of the present invention is not particularly limited and may be produced by any method. liquid) is prepared, the antiglare layer-forming material (coating liquid) is applied to form a coating film, and the coating film is cured to form an antiglare layer. A transfer method using a mold, a method of imparting an uneven shape by an appropriate method such as sandblasting, embossing roll, or the like can also be used together.

The solvent is not particularly limited, and various solvents can be used. One type may be used alone, or two or more types may be used in combination. There is an optimum solvent type and solvent ratio depending on the composition of the resin, the types and contents of the particles and the thixotropy-imparting agent, and the like. Examples of solvents include, but are not limited to, alcohols such as methanol, ethanol, isopropyl alcohol, butanol, and 2-methoxyethanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone; methyl acetate, ethyl acetate. , Esters such as butyl acetate; Ethers such as diisopropyl ether and propylene glycol monomethyl ether; Glycols such as ethylene glycol and propylene glycol; Cellosolves such as ethyl cellosolve and butyl cellosolve; Aliphatic hydrocarbons such as hexane, heptane and octane Aromatic hydrocarbons such as benzene, toluene, and xylene.

By appropriately selecting the solvent, the thixotropy of the antiglare layer-forming material (coating liquid) by the thixotropy-imparting agent can be exhibited satisfactorily. For example, when organoclays are used, toluene and xylene can be suitably used alone or in combination. They can be used or used in combination. For example, when modified urea is used, butyl acetate and methyl isobutyl ketone can be preferably used alone or in combination.

Various leveling agents can be added to the antiglare layer-forming material. As the leveling agent, for example, a fluorine-based or silicone-based leveling agent can be used for the purpose of preventing coating unevenness (uniformizing the coated surface). A suitable leveling agent is selected according to the case where the antifouling property is required on the surface of the antiglare layer of the present invention, or the case where an antireflection layer or a layer containing an interlayer filler is formed on the antiglare layer. be able to. For example, the inclusion of the thixotropy-imparting agent makes it possible to express thixotropic properties in the coating liquid, so that unevenness in coating is less likely to occur. Therefore, for example, it has an advantage that the options for the leveling agent can be expanded.

The amount of the leveling agent compounded is, for example, 5 parts by weight or less, preferably in the range of 0.01 to 5 parts by weight, per 100 parts by weight of the resin.

Pigments, fillers, dispersants, plasticizers, ultraviolet absorbers, surfactants, antifouling agents, antioxidants, etc., are added to the antiglare layer-forming material as necessary within a range that does not impair the performance. may be These additives may be used singly or in combination of two or more.

For the antiglare layer-forming material, conventionally known photopolymerization initiators, such as those described in JP-A-2008-88309, can be used.

Examples of the method for applying the antiglare layer-forming material include a fountain coating method, a die coating method, a spin coating method, a spray coating method, a gravure coating method, a roll coating method, a bar coating method, and the like. can be done.

The antiglare layer-forming material is applied to form a coating film, and the coating film is cured. It is preferable to dry the coating film prior to the curing. The drying may be, for example, natural drying, air drying by blowing air, heat drying, or a combination thereof.

The means for curing the coating film of the antiglare layer-forming material is not particularly limited, but ultraviolet curing is preferable. The irradiation amount of the energy beam source is preferably 50 to 500 mJ/cm ² as an integrated exposure amount at an ultraviolet wavelength of 365 nm. When the irradiation dose is 50 mJ/cm ² or more, the curing becomes more sufficient, and the hardness of the formed antiglare layer becomes more sufficient. Also, if it is 500 mJ/cm ² or less, coloring of the formed antiglare layer can be prevented.

The antiglare layer of the present invention can be formed as described above. In addition, you may form an anti-glare layer by manufacturing methods other than the above-mentioned method. The hardness of the antiglare layer of the present invention is preferably 2H or higher in terms of pencil hardness, although it is also affected by the thickness of the layer.

The antiglare layer of the present invention may have a multi-layer structure in which two or more layers are laminated.

The antireflection layer described above may be placed on the antiglare layer of the present invention. For example, one factor that reduces the visibility of an OLED display device is the reflection of light at the interface between the air and the antiglare layer. An antireflection layer reduces the surface reflection. The antiglare layer and the antireflection layer of the present invention may each have a multi-layer structure in which two or more layers are laminated.

(middle layer)
The intermediate layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "intermediate layer of the present invention") is provided between the resin layer and the hard coat layer, antireflection layer, or antiglare layer. is formed in Formation of this intermediate layer improves adhesion between the resin layer and the hard coat layer, antireflection layer, or antiglare layer.

The mechanism by which the intermediate layer (also referred to as a permeation layer or compatible layer) of the present invention is formed is not particularly limited. It is formed in the process of coating, permeating, and drying the resin layer with a coating solution for coating, a coating solution for forming an antireflection layer, or a coating solution for forming an antiglare layer. In the drying step, for example, the coating liquid for forming a hard coat layer, the coating liquid for forming an antireflection layer, or the coating liquid for forming an antiglare layer permeates the resin layer, and the resin derived from the resin layer and the hard coat The intermediate layer is formed comprising a layer, an antireflection layer, or a resin derived from the antiglare layer. The resin contained in the intermediate layer is not particularly limited. For example, the resin contained in the resin layer and the resin contained in the hard coat layer, the antireflection layer, or the antiglare layer are simply mixed (compatible). It's okay. At least one of the resin contained in the intermediate layer and the resin contained in the hard coat layer, the antireflection layer, or the antiglare layer may be chemically cured by heating, light irradiation, or the like. may have changed.

The thickness ratio R of the intermediate layer defined by the following formula (3) is not particularly limited, but is, for example, 0.10 to 0.80. 0.30 or more, 0.40 or more, or 0.45 or more, for example, 0.75 or less, 0.70 or less, 0.65 or less, 0.60 or less, 0.50 or less, It may be 0.40 or less, 0.45 or less, or 0.30 or less. The thickness ratio R of the intermediate layer is, for example, 0.15 to 0.75, 0.20 to 0.70, 0.25 to 0.65, 0.30 to 0.60, 0.40 to 0.50. , 0.45-0.50, 0.15-0.45, 0.15-0.40, 0.15-0.30, or 0.20-0.30. The intermediate layer can be confirmed, for example, by observing the cross section of the optical element with a transmission electron microscope (TEM), and the thickness can be measured.

R=[DC/(DC+DB)] (3)

In the formula (3), DB is the thickness [μm] of the hard coat layer, the antireflection layer, or the antiglare layer, and DC is the thickness [μm] of the intermediate layer.

When an intermediate layer is formed between a resin layer and a hard coat layer, an antireflection layer, or an antiglare layer, shear failure between the resin layer and the hard coat layer, antireflection layer, or antiglare layer From the viewpoint of excellent adhesion, the strength is preferably 20 MPa or more, more preferably 50 MPa or more.
The shear breaking strength can be obtained by the SAICAS method, and the type of resin layer, the composition of the coating liquid for forming the hard coat layer, the coating liquid for forming the antireflection layer, the coating liquid for forming the antiglare layer, and the film formation It can be adjusted according to the law.

(shock absorption layer)
The impact-absorbing layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "impact-absorbing layer of the present invention") may be composed of any appropriate resin layer capable of achieving a desired impact-absorbing rate. The resin layer may be composed of a resin film or an adhesive. The shock absorbing layer typically contains epoxy resin, urethane resin or acrylic resin. These resins may be used alone or in combination.

The thickness of the shock absorbing layer of the present invention is preferably 30 µm to 200 µm, more preferably 30 µm to 150 µm, still more preferably 40 µm to 120 µm. If the thickness of the impact-absorbing layer of the present invention is within such a range, an optical laminate having excellent impact resistance can be realized.

The storage elastic modulus G' of the shock absorbing layer of the present invention at 25°C is preferably 0.1 GPa or less, more preferably 0.01 MPa to 0.1 GPa. If the storage elastic modulus of the impact-absorbing layer of the present invention is within such a range, there is an advantage that the impact can be absorbed and cracking of the optical layered body can be prevented. Furthermore, a synergistic effect with the thickness effect can also be exhibited.

(Antistatic layer)
The antistatic layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "antistatic layer of the present invention") is not particularly limited, but for example, a conductive coating liquid containing a conductive polymer is coated. It is the antistatic layer that is formed. Specific coating methods include a roll coating method, a bar coating method, a gravure coating method, and the like.

Examples of the conductive polymer include a conductive polymer obtained by doping a π-conjugated conductive polymer with a polyanion. Examples of π-conjugated conductive polymers include linear conductive polymers such as polythiophene, polypyrrole, polyaniline, and polyacetylene. Polyanions include polystyrene sulfonic acid, polyisoprene sulfonic acid, polyvinyl sulfonic acid, polyallylsulfonic acid, polyethyl acrylate sulfonic acid, polymethacrylic carboxylic acid and the like.

The thickness of the antistatic layer is preferably 1 nm to 1000 nm, more preferably 5 nm to 900 nm. The antistatic layer may consist of only one layer, or may consist of two or more layers.

(Optical laminate)
In the optical laminate of the present invention, in the reflectance spectrum of the OLED display device in which the optical laminate for an OLED display device is not laminated, Rp1 is the maximum value at a wavelength of 380 to 455 nm, and the wavelength (WL1) at Rp1 is When the reflectance of the antireflection layer is Rf1, [Rf1/Rp1] is preferably 0.3 or less, more preferably 0.25 or less, still more preferably 0.2 or less, and still more preferably 0.15 or less. , particularly preferably 0.1 or less. The smaller the [Rf1/Rp1], the more the interference unevenness is suppressed.

In the optical laminate of the present invention, in the reflectance spectrum of the OLED display device in which the optical laminate for an OLED display device is not laminated, Rp2 is the maximum value at a wavelength of 460 to 530 nm, and the wavelength (WL2) at Rp2 is When the reflectance of the antireflection layer is Rf2, [Rf2/Rp2] is preferably 0.12 or less, more preferably 0.1 or less, still more preferably 0.05 or less, and still more preferably 0.03 or less. , particularly preferably 0.01 or less. The smaller the [Rf2/Rp2], the more the interference unevenness is suppressed.

In this specification, the wavelength WL1 is, for example, 430 nm or 440 nm, and the wavelength WL2 is, for example, 500 nm or 510 nm. Also, each of Rp1 and Rp2 is, for example, 7% or more (eg, 7 to 20%), preferably 10% or more (eg, 10 to 18%).

The sum of [Rf1/Rp1] and [Rf2/Rp2] is preferably 0.42 or less, more preferably 0.4 or less, still more preferably 0.3 or less, still more preferably 0.2 or less, and particularly preferably is 0.1 or less. Interference unevenness is more suppressed as the total is smaller.

The optical laminate of the present invention preferably has a configuration comprising the hard coat layer of the present invention, the substrate layer of the present invention, and the adhesive layer of the present invention on the side opposite to the viewing side of the antireflection layer of the present invention. It is more preferable to have structures with this order. The resin layer of the present invention or the glass layer of the present invention can be used for the substrate layer.

In one embodiment of the optical layered body of the present invention (for example, an optical layered body in an OLED display device of the present invention shown in FIGS. 3 and 4 described later), the pressure-sensitive adhesive layer of the present invention (in particular, a light-scattering pressure-sensitive adhesive layer) is provided on at least one surface of the resin layer of the present invention. In this case, n1>n2>n3, where n1 is the refractive index of the resin layer of the present invention, n2 is the refractive index of the adhesive in the adhesive layer of the present invention, and n3 is the refractive index of the light-scattering fine particles of the present invention. is preferably satisfied. In this case, white blurring is further suppressed.

In one embodiment of the optical layered body of the present invention (for example, an optical layered body in an OLED display device of the present invention shown in later-described FIGS. 3 and 4), the refractive index (n1) of the resin layer of the present invention is preferably 1. 0.50 to 1.80, more preferably 1.55 to 1.75, still more preferably 1.60 to 1.70. The refractive index of the resin layer can be adjusted by the type and content of the resin constituting the resin layer.

In one embodiment of the optical layered body of the present invention (for example, an optical layered body in an OLED display device of the present invention shown in later-described FIGS. 3 and 4), the pressure-sensitive adhesive layer of the present invention is provided on one side of the resin layer of the present invention. (In particular, the pressure-sensitive adhesive layer having light scattering properties) preferably has a structure in which the hard coat layer of the present invention is provided on the other surface. In particular, it is preferable to satisfy n1>n2>n3 in this embodiment.

In one embodiment of the optical layered body of the present invention (for example, the optical layered body in the OLED display device of the present invention shown in FIGS. 5 to 7 described later), a color filter is arranged on the viewing side of the OLED element, and the When the distance (d) between the pressure-sensitive adhesive layer and the color filter is 700 μm or less, the distance between the pressure-sensitive adhesive layer of the present invention (especially the pressure-sensitive adhesive layer having light scattering properties) and the color filter is When d [μm] and the haze value of the pressure-sensitive adhesive layer of the present invention (particularly, the pressure-sensitive adhesive layer having light scattering properties) is H [%], the value of d×H is preferably 70000 or less, and more It is preferably 60,000 or less, more preferably 50,000 or less. When the value of d×H is 700000 or less, image blurring is less likely to occur. The value of d×H is, for example, 100 or more, and may be 1000 or more, 10000 or more, or 20000 or more. In this case, H is preferably 20 or more.

In one embodiment of the optical layered body of the present invention (for example, an optical layered body in an OLED display device of the present invention shown in FIGS. 5 to 7 described later), the pressure-sensitive adhesive layer of the present invention (in particular, the pressure-sensitive adhesive layer having light scattering properties) ) is the thickness of T [μm], and the haze value of the pressure-sensitive adhesive layer of the present invention (especially the pressure-sensitive adhesive layer having light scattering properties) is H [%], the value of T×H is 400 or more. more preferably 600 or more, still more preferably 800 or more, still more preferably 1000 or more, and particularly preferably 1500 or more. When the value of T×H is 400 or less, image blurring is less likely to occur. The value of T×H is, for example, 10000 or less, and may be 8000 or less, 6000 or less, or 4000 or less.

In one embodiment of the optical layered body of the present invention (for example, the optical layered body in the OLED display device of the present invention shown in later-described FIGS. 8 to 10), the OLED display device without laminating the optical layered body for the OLED display device. When S1 is the scattering efficiency of the antiglare layer of the present invention at a wavelength WL1 showing the maximum value at a wavelength of 380 to 455 nm in the reflectance spectrum of , S1 is preferably 15% or more, more preferably 20% or more, More preferably 30% or more, more preferably 40% or more, particularly preferably 50% or more. The larger S1 is, the more the interference unevenness is suppressed.

In one embodiment of the optical layered body of the present invention (for example, the optical layered body in the OLED display device of the present invention shown in later-described FIGS. 8 to 10), the OLED display device without laminating the optical layered body for the OLED display device. When the scattering efficiency of the antiglare layer of the present invention at the wavelength WL2 showing the maximum value at a wavelength of 460 to 530 nm in the reflectance spectrum of is S2, S2 is preferably 15% or more, more preferably 20% or more, More preferably 30% or more, more preferably 40% or more, particularly preferably 50% or more. The larger S2 is, the more the interference unevenness is suppressed.

The scattering efficiencies S1 and S2 are obtained by measuring the optical layered body having the antiglare layer of the present invention in contact with an integrating sphere and measuring the transmittance at a predetermined wavelength, Tn1, and the optical layered body having the antiglare layer. is placed at a distance of 145 mm from the integrating sphere, and Tn2 is the transmittance at the predetermined wavelength.

The sum of S1 and S2 is preferably 30% or more, more preferably 40% or more, still more preferably 60% or more, still more preferably 80% or more, and particularly preferably 100% or more. The larger the sum, the more the interference unevenness is suppressed.

In one embodiment of the optical layered body of the present invention (for example, an optical layered body in an OLED display device of the present invention shown in FIGS. 8 to 10 described later), a base material is provided on the side opposite to the viewing side of the antiglare layer of the present invention. It is preferable to have a structure comprising a layer and the pressure-sensitive adhesive layer of the present invention, and more preferably to have a structure provided in this order. The resin layer of the present invention or the glass layer of the present invention can be used for the substrate layer.

One embodiment of the optical layered body of the present invention (for example, an optical layered body in an OLED display device of the present invention shown in FIGS. 14 and 15 described later) is an optical element of the present invention on the viewing side of the glass layer of the present invention. , the pressure-sensitive adhesive layer of the present invention, the substrate layer, and the hard coat layer of the present invention, and more preferably have a structure provided in this order. The resin layer of the present invention or the glass layer of the present invention can be used for the substrate layer.

In one embodiment of the optical layered body of the present invention (for example, an optical layered body in an OLED display device of the present invention shown in later-described FIGS. 14 and 15), the indentation elastic modulus of the adhesive layer of the present invention is Ea, and the indentation elastic modulus of the adhesive layer of the present invention is Ea. When the tensile storage modulus of the resin layer is Er, the absolute value of Ea-Er is preferably 1 GPa or less, more preferably 0.9 GPa or less, still more preferably 0.7 GPa or less, and particularly preferably 0.5 GPa. It is below. Impact resistance improves further that the said absolute value is 1 GPa or less.

In one embodiment of the optical layered body of the present invention (for example, an optical layered body in an OLED display device of the present invention shown in FIGS. 14 and 15 to be described later), the resin layer of the present invention has a tensile storage elastic modulus Er of 4 GPa or more. is preferred, more preferably 4.3 GPa or more, still more preferably 4.6 GPa or more. When the tensile storage elastic modulus Er is 4 GPa or more, impact resistance is further improved. The tensile storage elasticity Er is, for example, 50 GPa or less, and may be 30 GPa or less, or 10 GPa or less. The tensile storage modulus Er can be measured according to JIS K7161.

In one embodiment of the optical layered body of the present invention (for example, an optical layered body in an OLED display device of the present invention shown in FIGS. 16 and 17 described later), between the transparent polyimide layer and the hard coat layer of the present invention, It is preferable to have a structure in which an intermediate layer (compatible layer) is formed. By forming the intermediate layer, the adhesion between the transparent polyimide layer and the hard coat layer of the present invention is improved. The intermediate layer is a layer formed by permeation of the composition (coating agent) for forming the hard coat layer of the present invention into the transparent polyimide layer. That is, the intermediate layer is a portion of the transparent polyimide layer where the hard coat layer components of the present invention are present.

The ratio (P1) of the shear fracture strength of the intermediate layer to the shear fracture strength of the hard coat layer of the present invention is preferably 0.25 or less, more preferably 0.23, and still more preferably 0.21 or less. The ratio (P1) is, for example, 0.02 or more, and may be 0.05 or more, or 0.08 or more.

In one embodiment of the optical layered body of the present invention (for example, the optical layered body in the OLED display device of the present invention shown in FIGS. 16 and 17 described later), the ratio of the transparent polyimide layer to the shear fracture strength of the hard coat layer of the present invention The shear breaking strength ratio (P2) is preferably 0.65 or more, more preferably 0.70 or more, still more preferably 0.80 or more, and particularly preferably 0.90 or more. The ratio (P2) is, for example, 1.50 or less, and may be 1.30 or less, or 1.10 or less.

The difference (P2-P1) between the ratio (P1) and the ratio (P2) is preferably 0.6 or more, more preferably 0.70 or more, and may be 0.80 or more. The difference (P2-P1) is, for example, 1.5 or less, and may be 1.2 or less, or 0.9 or less.

In one embodiment of the optical layered body of the present invention (for example, an optical layered body in an OLED display device of the present invention shown in FIGS. 16 and 17 described later), the transparent polyimide layer on the side opposite to the hard coat layer of the present invention It is preferable to have a structure further provided with an adhesive layer.

(Manufacturing method of optical laminate)
The method for producing the optical laminate of the present invention is not particularly limited, and the adhesive layer, adhesive layer, resin layer, glass layer, hard coat layer, antireflection layer, antiglare layer, An intermediate layer (compatible layer), a shock absorbing layer, etc. can be produced by laminating sequentially on the viewing side of the OLED display panel of the present invention. It can be produced by preparing it in advance and laminating it on the viewing side of the OLED display panel of the present invention. When the laminate constituting the optical laminate of the present invention is prepared in advance, it may be the laminate constituting the entire optical laminate of the present invention, or the laminate constituting a part of the optical laminate of the present invention. may be split and laminated on the viewing side of the OLED display panel of the present invention.

The layers constituting the optical element of the present invention or the laminate thereof may be protected with a release liner or surface protection film until use.

(Release liner)
When the optical element of the present invention includes an adhesive layer, a release liner may be provided on the surface (adhesive surface) of the adhesive layer until use. A release liner is used as a protective material for the pressure-sensitive adhesive layer, and is peeled off when applied to an adherend. Note that the release liner does not constitute the optical element of the present invention and may not necessarily be provided.

As the release liner, a conventional release paper or the like can be used, and is not particularly limited. etc. Examples of the base material having the release treatment layer include plastic films and paper surface-treated with release agents such as silicone, long-chain alkyl, fluorine, and molybdenum sulfide. Examples of the fluorine-based polymer in the low-adhesive substrate made of the fluorine polymer include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chloro fluoroethylene-vinylidene fluoride copolymer and the like. Examples of the non-polar polymer include olefin resins (eg, polyethylene, polypropylene, etc.). The release liner can be formed by a known or commonly used method. Also, the thickness of the release liner is not particularly limited.

(Surface protection film)
The outermost surface (the outermost surface on the viewing side) of the optical layered body of the present invention may be protected with a surface protective film. The surface protection film may be applied by the consumer. The surface protective film does not constitute the optical element of the present invention and may not necessarily be provided.

As the surface protective film, a known or commonly used surface protective film can be used, and although it is not particularly limited, for example, a plastic film having an adhesive layer on its surface can be used. Examples of the plastic film include polyester (polyethylene terephthalate, polyethylene naphthalate, etc.), polyolefin (polyethylene, polypropylene, cyclic polyolefin, etc.), polystyrene, acrylic resin, polycarbonate, epoxy resin, fluororesin, silicone resin, diacetate resin, Examples thereof include plastic films formed from plastic materials such as triacetate resin, polyarylate, polyvinyl chloride, polysulfone, polyethersulfone, polyetheretherimide, polyimide, and polyamide. Examples of the adhesive layer include acrylic adhesives, natural rubber adhesives, synthetic rubber adhesives, ethylene-vinyl acetate copolymer adhesives, ethylene-(meth)acrylic acid ester copolymer adhesives, A pressure-sensitive adhesive layer formed from one or more known or commonly used pressure-sensitive adhesives such as a styrene-isoprene block copolymer-based pressure-sensitive adhesive and a styrene-butadiene block copolymer-based pressure-sensitive adhesive can be used. The pressure-sensitive adhesive layer may contain various additives (eg, antistatic agents, slip agents, etc.). In addition, the plastic film and the pressure-sensitive adhesive layer may each have a single-layer structure, or may have a multi-layer (multilayer) structure. Moreover, the thickness of the surface protective film is not particularly limited, and can be appropriately selected.

(OLED display device of the present invention)
An embodiment of an OLED display device in which the optical layered body of the present invention is laminated on the viewing side of an OLED display panel will be described below with reference to the drawings, but the present invention is not limited to this embodiment. FIG. 2 is a schematic cross-sectional view showing one embodiment of the basic configuration of an OLED display device laminated with the optical laminate of the present invention.

As shown in FIG. 2, in the OLED display device 200, the layers forming the optical laminate 20 are laminated on the visible side of the OLED display panel 100 (upper side in FIG. 2). Although the OLED display panel 100 is not particularly limited, for example, the same configuration as the OLED display panel 100 shown in FIG. 1 can be adopted.

In the OLED display device 200 of FIG. 2, 21 to 29 are layers constituting the optical laminate 20, 21 is an adhesive layer or adhesive layer, 22 is a resin layer, a glass layer or a shock absorbing layer, and 23 is a hard layer. Coat layer or anti-glare layer, 24 adhesive layer or adhesive layer, 25 resin layer, glass layer or shock absorbing layer, 26 adhesive layer or adhesive layer, 27 resin layer, glass layer or shock absorbing layer , 28 denotes a hard coat layer or an antiglare layer, and 29 denotes an antireflection layer. The laminated structure of the optical laminated body 20 shown in FIG. 2 is not limited to this embodiment, and the optical element of the present invention is formed between arbitrary layers of the laminated structure of the optical laminated body 20 shown in FIG. Other layers may be interposed and any layer of the laminate structure of the optical stack 20 shown in FIG. 2 may be absent.

As a preferred embodiment of the present invention, in FIG. 2, 24 is an adhesive layer or adhesive layer, 25 is a resin layer, glass layer or impact absorbing layer, 26 is an adhesive layer or adhesive layer, and 27 is a resin layer. , a glass layer or an impact absorbing layer, 28 is a hard coat layer or an antiglare layer, 21 to 23 are absent, and at least one of the adhesive layers 24 and 26 is an adhesive layer having light scattering properties. FIG. 3 shows an OLED display device 300A according to this embodiment. In FIG. 3, 34A to 38A are layers constituting the optical laminate 30A, 34A is an adhesive layer or adhesive layer, 35A is a glass layer, 36A is an adhesive layer having light scattering properties, and 37A is a resin layer. , 38A is a hard coat layer. Since the pressure-sensitive adhesive layer 36A has light scattering properties, color shift and uneven interference caused by the OLED display panel 100 are suppressed, and the OLED display device 300 has excellent visibility.
In addition, in the OLED display device 300A shown in FIG. 3, an antireflection layer may be present on the visible side of the hard coat layer 38A.

As a preferred embodiment of the present invention, in FIG. 2, 21 is an adhesive layer, 22 is a resin layer, 23 is a hard coat layer, 24 is an adhesive layer, 25 is a glass layer, 26 is an adhesive layer, 27 Resin layer 28 is a hard coat layer, antireflection layer 29 is not present, and at least one of adhesive layers 21, 24, and 26 is an adhesive layer having light scattering properties. FIG. 4 shows an OLED display device 300B according to this embodiment. In FIG. 4, 31B to 38B are layers constituting the optical laminate 30B, 31B is an adhesive layer, 32B is a resin layer, 33B is a hard coat layer, 34B is an adhesive layer, 35B is a glass layer, and 36B is a An adhesive layer having light scattering properties, 37B is a resin layer, and 38B is a hard coat layer. Since the pressure-sensitive adhesive layer 36B has light scattering properties, color shift and uneven interference caused by the OLED display panel 100 are suppressed, and the OLED display device 300B has excellent visibility.
In addition, in the OLED display device 300B shown in FIG. 4, an antireflection layer may exist on the visible side of the hard coat layer 38B.

As another preferred embodiment of the present invention, in FIG. 2, the OLED display panel 100 has a color filter arranged on the viewing side, 26 is an adhesive layer having light scattering properties, 27 is a resin layer, and 28 is The distance d (μm) between the pressure-sensitive adhesive layer 26, which is a hard coat layer, does not include 21 to 25 and 29 and has light scattering properties, and the color filter is 700 μm or less. Since the distance d between the adhesive layer having light scattering properties and the color filter is 700 μm or less, the light scattering layer is laminated to suppress color shift and interference unevenness caused by the OLED display device 300. Also, image blurring is less likely to occur, and visibility is excellent. FIG. 5 shows an OLED display device 400A according to this embodiment. In FIG. 5, 46A to 48A are layers constituting the optical laminate 40A, 46A is an adhesive layer having light scattering properties, 47A is a resin layer, and 48A is a hard coat layer. 15A is a color filter arranged on the viewing side (upper side in FIG. 5) of the OLED display panel 400A. The pressure-sensitive adhesive layer 46A having light scattering properties and the color filter 15A are in direct contact, that is, the distance between the pressure-sensitive adhesive layer 46A having light scattering properties and the color filter 15A is 0 μm. Color shift and interference unevenness due to 400A can be suppressed most efficiently.
In addition, in the OLED display device 400A shown in FIG. 5, an antireflection layer may be present on the visible side of the hard coat layer 48A.

As another preferred embodiment of the present invention, in FIG. 2, the OLED display panel 100 has a color filter arranged on the viewing side, 24 is an adhesive layer having light scattering properties, 25 is a glass layer, and 26 is An adhesive layer or adhesive layer, 27 is a resin layer, 28 is a hard coat layer, 21 to 23 and 29 are absent, and the distance d (μm) between the adhesive layer 24 having scattering properties and the color filter ) is 700 μm or less. Since the distance d between the adhesive layer having light scattering properties and the color filter is 700 μm or less, the light scattering layer is laminated to suppress color shift and interference unevenness caused by the OLED display device 300. Also, image blurring is less likely to occur, and visibility is excellent. FIG. 6 shows an OLED display device 400B according to this embodiment. In FIG. 6, 44B to 48B are layers constituting the optical laminate 40B, 44B is an adhesive layer having light scattering properties, 44B is an adhesive layer having light scattering properties, 45B is a glass layer, and 46B is an adhesive layer. An agent layer or an adhesive layer, 47B a resin layer, and 48B a hard coat layer. 15B is a color filter arranged on the viewing side (upper side in FIG. 6) of the OLED display panel 400B. The pressure-sensitive adhesive layer 44B having light scattering properties and the color filter 15B are in direct contact, that is, the distance between the pressure-sensitive adhesive layer 44B having light scattering properties and the color filter 15B is 0 μm. Color shift and interference unevenness due to 400B can be suppressed most efficiently.
In addition, in the OLED display device 400B shown in FIG. 6, an antireflection layer may exist on the visible side of the hard coat layer 48B.

As another preferred embodiment of the present invention, in FIG. is an adhesive layer, 25 is a glass layer, 26 is an adhesive layer, 27 is a resin layer, and 28 is a hard coat layer. The pressure-sensitive adhesive layer has a light-scattering property, and the distance d (μm) between the pressure-sensitive adhesive layer having a light-scattering property and the color filter is 700 μm or less. Since the distance d between the adhesive layer having light scattering properties and the color filter is 700 μm or less, the light scattering layer is laminated to suppress color shift and interference unevenness caused by the OLED display device 300. Also, image blurring is less likely to occur, and visibility is excellent. From the viewpoint of more efficiently reducing image blur in an OLED display device due to lamination of a light scattering layer, the distance between the pressure-sensitive adhesive layer having light scattering properties and the color filter is more preferably 600 μm or less. , 500 μm or less, and most preferably, the pressure-sensitive adhesive layer having light scattering properties and the color filter are in direct contact with each other. OLED display devices 400C and 400D according to this embodiment are shown in FIGS. 7(a) and 7(b), respectively. In FIG. 7A, 41C to 48C are layers constituting the optical laminate 40C, 41C is an adhesive layer, 42C is a resin layer, 43C is a hard coat layer, 44C is an adhesive layer, and 45C is a glass layer. , 46C is an adhesive layer having light scattering properties, 47C is a resin layer, and 48C is a hard coat layer. 15C is a color filter arranged on the viewing side (upper side in FIG. 7A) of the OLED display panel 400C, and the distance d (μm) between the adhesive layer 46D having light scattering properties and the color filter 15C. is 700 μm or less. In FIG. 7B, 41D to 48D are layers constituting the optical laminate 40D, 41D is an adhesive layer having light scattering properties, 42D is a resin layer, 43D is a hard coat layer, and 44D is an adhesive layer. , 45D is a glass layer, 46D is an adhesive layer, 47D is a resin layer, and 48D is a hard coat layer. 15D is a color filter arranged on the viewing side (upper side in FIG. 7B) of the OLED display panel 400D. The pressure-sensitive adhesive layer 41D having light scattering properties and the color filters 15D are in direct contact, that is, the distance between the pressure-sensitive adhesive layer 41D having light scattering properties and the color filters 15D is 0 μm. Color shift and interference unevenness due to 400D can be most efficiently suppressed.
In addition, in the OLED display devices 400C and 400D shown in FIGS. 7A and 7B, an antireflection layer may be present on the viewing side of the hard coat layers 48C and 48D.

As another preferred embodiment of the present invention, in FIG. 2, 26 is an adhesive layer or adhesive layer, 27 is a resin layer, 28 is an antiglare layer, and 21 to 25 and 29 are absent. FIG. 8 shows an OLED display device 500A according to this embodiment. In FIG. 8, 56A to 58A are layers constituting the optical layered body 50A, 56A is an adhesive layer or adhesive layer, 57A is a resin layer, and 58A is an antiglare layer. Since the optical layered body 50A has the antiglare layer 58A, color shift and interference unevenness caused by the OLED display panel 100 are suppressed, and the OLED display device 500A has excellent visibility.
In addition, in the OLED display device 500A shown in FIG. 8, an antireflection layer may exist on the viewing side of the antiglare layer 58A.

2, 24 is an adhesive layer or adhesive layer, 25 is a glass layer, 26 is an adhesive layer or adhesive layer, 27 is a resin layer, and 28 is an antiglare layer. layer and 21-23 and 29 are absent. FIG. 9 shows an OLED display device 500B according to this embodiment. In FIG. 9, 54B to 58B are layers constituting the optical laminate 50B, 54B is an adhesive layer or adhesive layer, 55B is a glass layer, 56B is an adhesive layer or adhesive layer, 57B is a resin layer, 58B is an antiglare layer. Since the optical layered body 50B has the antiglare layer 58B, color shift and interference unevenness caused by the OLED display panel 100 are suppressed, and the OLED display device 500B has excellent visibility.
In addition, in the OLED display device 500B shown in FIG. 9, an antireflection layer may exist on the viewing side of the antiglare layer 58B.

As another preferred embodiment of the present invention, in FIG. 2, 21 is an adhesive layer, 22 is a resin layer, 23 is a hard coat layer, 24 is an adhesive layer, 25 is a glass layer, 26 is an adhesive layer, 27 is a resin layer, 28 is an antiglare layer, and the antireflection layer 29 is not present. FIG. 10 shows an OLED display device 500C according to this embodiment. In FIG. 10, 51C to 58C are layers constituting an optical laminate 50C, 51C is an adhesive layer, 52C is a resin layer, 53C is a hard coat layer, 54C is an adhesive layer, 55C is a glass layer, and 56C is a glass layer. An adhesive layer, 57C is a resin layer, and 58C is an antiglare layer. Since the optical layered body 50C has the antiglare layer 58C, color shift and interference unevenness caused by the OLED display panel 100 are suppressed, and the OLED display device 500C has excellent visibility.
In addition, in the OLED display device 500C shown in FIG. 10, an antireflection layer may exist on the viewing side of the antiglare layer 58C.

As another preferred embodiment of the present invention, in FIG. does not exist. FIG. 11 shows an OLED display device 600A according to this embodiment. In FIG. 11, 61A to 69A are layers constituting an optical laminate 60A, 66 is an adhesive layer or adhesive layer, 67A is a resin layer, 68A is a hard coat layer, and 69A is an antireflection layer. Since the optical laminate 60A has the antireflection layer 69A, interference unevenness caused by the OLED display panel 100 is suppressed, and the OLED display device 600A has excellent visibility.
In the OLED display device 600A shown in FIG. 11, 68A may be an antiglare layer, or an antiglare layer may be laminated between the hard coat layer 68A and the antireflection layer 69A. In this embodiment, the antireflection function is further improved by laminating the antiglare layer 68A and the antireflection layer 69A.

As another preferred embodiment of the present invention, in FIG. 2, 24 is an adhesive layer or adhesive layer, 25 is a glass layer, 26 is an adhesive layer or adhesive layer, 27 is a resin layer, and 28 is a hard coat. layer, antireflection layer 29 is present and 21-23 are absent. FIG. 12 shows an OLED display device 600B according to this embodiment. In FIG. 12, 61B to 69B are layers constituting the optical laminate 60B, 64B is an adhesive layer or adhesive layer, 65B is a glass layer, 66B is an adhesive layer or adhesive layer, 67B is a resin layer, 68B is a hard coat layer, and 69B is an antireflection layer. Since the optical layered body 60B has the antireflection layer 69B, interference unevenness caused by the OLED display panel 100 is suppressed, and the OLED display device 600B has excellent visibility.
In the OLED display device 600B shown in FIG. 12, 68B may be an antiglare layer, or an antiglare layer may be laminated between the hard coat layer 68B and the antireflection layer 69B. In this embodiment, the antireflection function is further improved by laminating the antiglare layer 68B and the antireflection layer 69B.

As another preferred embodiment of the present invention, in FIG. 2, 21 is an adhesive layer, 22 is a resin layer, 23 is a hard coat layer, 24 is an adhesive layer, 25 is a glass layer, 26 is an adhesive layer, 27 is a resin layer, 28 is a hard coat layer, and an antireflection layer 29 is present. FIG. 13 shows an OLED display device 600C according to this embodiment. In FIG. 13, 61C to 69C are layers constituting an optical laminate 60C, 61C is an adhesive layer, 62C is a resin layer, 63C is a hard coat layer, 64C is an adhesive layer, 65C is a glass layer, and 66C is a glass layer. An adhesive layer, 67C is a resin layer, 68C is a hard coat layer, and 69C is an antireflection layer. Since the optical layered body 60C has the antireflection layer 69C, interference unevenness caused by the OLED display panel 100 is suppressed, and the OLED display device 600C has excellent visibility.
In the OLED display device 600C shown in FIG. 13, 68C may be an antiglare layer, or an antiglare layer may be laminated between the hard coat layer 68C and the antireflection layer 69C. In this embodiment, the antireflection function is further improved by laminating the antiglare layer 68C and the antireflection layer 69C.

As another preferred embodiment of the present invention, in FIG. 2, 21 is a pressure-sensitive adhesive layer or adhesive layer, 22 is a resin layer, 23 is absent, 24 is an adhesive layer, and 25 is a glass layer, 26-29 do not exist. FIG. 14 shows an OLED display device 700A according to this embodiment. In FIG. 14, 71A, 72A, 74A, and 75A are layers constituting the optical laminate 70A, 71A is a pressure-sensitive adhesive layer or adhesive layer, 72A is a resin layer, 73A is absent, and 74A is an adhesive. Layer, 75A, is a glass layer. In FIG. 14, by bonding the resin layer 72A and the glass layer 75A with the adhesive layer 74A, even if the optical layered body 70A does not have a polarizing plate, excellent impact resistance is imparted. be. Also, the glass layer is a material that is easily broken and has low flexibility, although it has excellent impact resistance. By bonding the glass layer and the resin layer with an adhesive layer, flexibility and bendability are improved, and the OLED display device 700A can be used for flexible devices and foldable devices.

As another preferred embodiment of the present invention, in FIG. 2, 21 is an adhesive layer, 22 is a resin layer, 23 is absent, 24 is an adhesive layer, 25 is a glass layer, 26 is an adhesive layer, 27 is a resin layer, 28 is a hard coat layer, and the antireflection layer 29 is not present. Alternatively, in FIG. 2, 21 is an adhesive layer, 22 is a resin layer, 23 is a hard coat layer, 24 is an adhesive layer, 25 is a glass layer, 26 is an adhesive layer, 27 is a resin layer, and 28 is a hard coat layer. and the antireflection layer 29 does not exist. OLED display devices 700B and 700C according to this embodiment are shown in FIGS. 15(a) and 15(b), respectively. In FIG. 15(a), 71B, 72B, 74B to 78B are layers constituting the optical laminate 70B, 71B is an adhesive layer, 72B is a resin layer, 74B is an adhesive layer, 75B is a glass layer, and 76B. is an adhesive layer, 77B is a resin layer, and 78B is a hard coat layer. Further, in FIG. 15B, 71C to 78C are layers constituting an optical laminate 70C, 71C is an adhesive layer, 72C is a resin layer, 73C is a hard coat layer, 74C is an adhesive layer, and 75C is A glass layer, 76C an adhesive layer, 77C a resin layer, and 78C a hard coat layer. In FIG. 15(a), the resin layer 72B and the glass layer 75B are bonded by the adhesive layer 74B, or in FIG. 15(b), the glass layer 75C and the resin layer 77C are bonded by the adhesive. Bonding by layer 76C imparts excellent impact resistance to each of optical stacks 70B and 70C even if they do not have polarizers. Also, the glass layer is a material that is easily broken and has low flexibility, although it has excellent impact resistance. By bonding the glass layer and the resin layer with an adhesive layer, flexibility and bendability are improved, and the OLED display devices 700B and 700C can be used for flexible devices and foldable devices.
In addition, in the OLED display devices 700B and 700C shown in FIGS. 15A and 15B, an antireflection layer may be present on the visible side of the hard coat layers 78B and 78C.

As another preferred embodiment of the present invention, in FIG. 2, 21 is an adhesive layer, 22 is a resin layer, 23 is a hard coat layer, 24 to 29 are absent, and the resin layer 22 is a transparent polyimide layer. is. FIG. 16 shows an OLED display device 800A according to this embodiment. In FIG. 16, 81A to 83A are layers constituting an optical laminate 80A, 81A is an adhesive layer or adhesive layer, 82A is a transparent polyimide layer, and 83A is a hard coat layer. In FIG. 16, the optical layered body 80A having the transparent polyimide layer 82A and the hard coat layer 83A provides excellent impact resistance even when the optical layered body 80A does not have a polarizing plate. Also, in this embodiment, the optical layered body 80A does not have a glass layer. The glass layer is a material that exhibits high hardness and excellent impact resistance, but is poor in handleability and is difficult to use for large displays used in PCs, tablets, and the like. By laminating a transparent polyimide layer and a hard coat layer, it is possible to achieve a high hardness equivalent to that of a glass layer, and it is also easy to handle, so it can be applied to large displays used in PCs, tablets, etc.

As another preferred embodiment of the present invention, in FIG. Layer 28 is a hard coat layer, antireflection layer 29 is absent, and either or both of resin layers 22 and 27 are transparent polyimide layers. FIG. 17 shows an OLED display device 800B according to this embodiment. In FIG. 17, 81B to 84B, 87B, and 88B are layers constituting the optical laminate 80B, 81B is an adhesive layer, 82B is a transparent polyimide layer, 83B is a hard coat layer, 84B is an adhesive layer, and 87B is A resin layer 88B is a hard coat layer. In FIG. 17, the optical layered body 80B having the transparent polyimide layer 82B and the hard coat layer 83B provides excellent impact resistance even when the optical layered body 80B does not have a polarizing plate. Also, in this embodiment, the optical layered body 80B does not have a glass layer. The glass layer is a material that exhibits high hardness and excellent impact resistance, but is poor in handleability and is difficult to use for large displays used in PCs, tablets, and the like. By laminating a transparent polyimide layer and a hard coat layer, it is possible to achieve a high hardness equivalent to that of a glass layer, and it is also easy to handle, so it can be applied to large displays used in PCs, tablets, etc.

In the embodiment shown in FIGS. 16 and 17, intermediate layers (compatible layers) are formed between the transparent polyimide layer 82A and the hard coat layer 83A and between the transparent polyimide layer 82B and the hard coat layer 83B. is preferred (not shown). By forming an intermediate layer (compatible layer) between the transparent polyimide layers 82A, B and the hard coat layers 83A, B, adhesion between the transparent polyimide layers 82A, B and the hard coat layers 83A, B is improved. do. In that case, the shear breaking strength between the transparent polyimide layers 82A, B and the hard coat layers 83A, B is preferably 20 MPa or more.

Although the present invention will be described in more detail with reference to examples below, the present invention is not limited by these examples.

Example 1
<OLED display device>
An OLED display device was prepared by peeling off the optical film laminated on the viewing side of a 4K OLED monitor (model number: EPS269Q015A) manufactured by JOLED Corporation.

<Formation of hard coat layer>
100 parts by weight of an ultraviolet curable polyfunctional acrylic resin composition in terms of solid content (trade name “Z-850-50H-D”, manufactured by Aica Kogyo Co., Ltd., solid content concentration: 44 wt%), and photopolymerization initiation An agent (trade name “Omnirad2959”, manufactured by IGM Resins Italia Srl) 4 parts by weight and a leveling agent (trade name “LE-303”, manufactured by Kyoeisha Chemical Co., Ltd.) 0.05 parts by weight are mixed and mixed. I got the liquid. Next, methyl isobutyl ketone was added to the resulting mixture to obtain a composition for forming a hard coat layer having a solid concentration of 40% by weight. Next, the composition for forming a hard coat layer was applied to one surface of a PET film (trade name “50U48”, manufactured by Toray Industries, Inc., thickness: 50 μm) as a transparent film substrate to form a coating film. . Next, this coating film was dried by heating at a temperature of 80° C. for 60 seconds, and then cured by ultraviolet irradiation. When irradiating with ultraviolet rays, a high-pressure mercury lamp was used as a light source, ultraviolet rays with a wavelength of 365 nm were used, and the integrated amount of light was set at 300 mJ/cm ² . As a result, a hard coat layer having a thickness of 3 μm was formed on the PET film.

<Surface treatment of hard coat layer>
Then, the surface of the hard coat layer was plasma-treated in a roll-to-roll type plasma treatment apparatus in a vacuum atmosphere of 1.0 Pa while transporting the PET film on which the hard coat layer was formed. During the plasma treatment, argon gas was used as an inert gas, and the discharge power was set to 150W. As a result, an optical film including a PET film and a plasma-treated hard coat layer was obtained.

<Formation of primer layer>
Next, the heated optical film was introduced into a roll-to-roll type sputtering film forming apparatus, and the pressure in the film forming chamber was reduced to 1×10 ⁻⁴ Pa. Next, while conveying the optical film, argon gas and oxygen gas were introduced at a volume ratio of 100:10, the surface temperature of the film-forming roll was set to -8°C, and a thickness of 1.5°C was formed on the hard coat layer by a sputtering method. An ITO layer (primer layer) of 5 nm was formed. An ITO target containing indium oxide and tin oxide at a weight ratio of 90:10 was used as the target material for forming the primer layer. Further, when the film was formed by the sputtering method, the power source was an MFAC power supply, the discharge power was 2.5 kW, and the pressure in the film formation chamber was 0.2 Pa.

<Formation of antireflection layer>
Following the formation of the primer layer, while transporting the optical film after the formation of the primer layer using a roll-to-roll type sputtering deposition apparatus, a first layer: Nb ₂ having a thickness of 12 nm was formed on the primer layer by a sputtering method. _O5 layer (refractive index: 2.32), 2nd layer: 29 nm thick _SiO2 layer (refractive index: 1.46), 3rd layer: ₁₀₇ nm thick _Nb2O5 layer, and 4th layer: thick An 81 nm SiO ₂ layer was deposited in this order. As a result, an antireflection layer having a four-layer structure (a four-layer structure consisting of a first layer, a second layer, a third layer, and a fourth layer) was formed on the primer layer. In the deposition of each of the first to fourth layers, the surface temperature of the deposition roll was −8° C., the power source was the MFAC power source, and the pressure in the deposition chamber was 0.7 Pa. In the deposition of the first layer, a Nb target was used, argon gas and oxygen gas were introduced at a volume ratio of 100:5, and the discharge power was set to 10.5 kW. In forming the second layer, a Si target was used, argon gas and oxygen gas were introduced at a volume ratio of 100:30, and the discharge power was set to 14 kW. In the deposition of the third layer, a Nb target was used, argon gas and oxygen gas were introduced at a volume ratio of 100:13, and the discharge power was set at 22 kW. In the deposition of the fourth layer, a Si target was used, argon gas and oxygen gas were introduced at a volume ratio of 100:30, and the discharge power was 12 kW.

<Formation of antifouling layer>
An alkoxysilane compound containing a perfluoropolyether skeleton (trade name “SHIN-ETSU SUBELYN KY1903-1”, manufactured by Shin-Etsu Chemical Co., Ltd.) is dried and solidified as a vapor deposition source, and the heating temperature of the vapor deposition source is was set to 260° C., and an antifouling layer having a thickness of 12 nm was formed on the antireflection layer by a vacuum deposition method. As a result, an optical laminate including a PET film, a hard coat layer, a primer layer, an antireflection layer, and an antifouling layer was obtained.

<Fabrication of OLED display device with optical laminate>
The optical layered body was laminated on the OLED display device via an acrylic pressure-sensitive adhesive layer such that the antifouling layer of the optical layered body was on the viewing side, to produce an OLED display device with the optical layered body.

Examples 2-4
OLED display devices with optical laminates of Examples 2 to 4 were produced by the same manufacturing method as in Example 1, except that the thicknesses of the first to fourth layers in the step of forming the antireflection layer were changed to the conditions shown in Table 1. made.

Comparative example 1
OLED display with an optical laminate of Comparative Example 1 by the same manufacturing method as in Example 1 except that the surface treatment of the hard coat layer, the formation of the primer layer, the formation of the antireflection layer, and the formation of the antifouling layer were not performed. A device was fabricated.

<Evaluation>
The following evaluations were performed on the OLED display devices with optical laminates and the like produced in Examples and Comparative Examples. Table 1 shows the results.

(1) Rf1, Rf2, Rp1, Rp2
A spectrophotometer manufactured by Hitachi High-Tech Co., Ltd. was used to measure the reflectance of the optical laminate at each wavelength of 380 to 780 nm. Next, the reflectance at each wavelength of 380 to 780 nm of the surface from which the optical film was removed of the OLED display device from which the optical film laminated on the viewing side of the 4K OLED monitor (model number: EPS269Q015A) made by JOLED Co., Ltd. was removed. , a spectrophotometer "CM-2600d" manufactured by Konica Minolta, Inc. to calculate the first peak wavelength WL1 (nm) and the second peak wavelength WL2 (nm). The first peak was the maximum value at a wavelength of 380-455 nm, and the second peak was the maximum value at a wavelength of 460-530 nm. Let Rp1 and Rp2 be the reflectances of the OLED monitor at the first peak wavelength WL1 (nm) and the second peak wavelength WL2 (nm), respectively, and at the first peak wavelength WL1 (nm) and the second peak wavelength WL2 (nm) The reflectances of the optical layered body were calculated as Rf1 and Rf2, respectively. The reflectance of the optical laminate in Examples 1 to 4 corresponds to the reflectance of the antireflection layer.

(2) Interference unevenness When the OLED display devices with the optical laminate obtained in Examples and Comparative Examples are turned off, and a three-wavelength fluorescent lamp is turned on at a distance of 30 cm from the OLED display device with the optical laminate, Interference unevenness on the surface of the OLED display device with the optical laminate was visually observed and evaluated according to the following criteria.
◎: No interference unevenness is visible at all 〇: Almost no interference unevenness is visible ×: Interference unevenness is clearly visible

Variations of the invention according to the present disclosure are described below.
[Appendix 1] An optical laminate used in an OLED display device in which only an optical element having a degree of polarization of 95% or less is laminated on the viewing side of the OLED element,
The optical laminate for an OLED display device, wherein the optical element has an antireflection layer at least on the viewing side.
[Appendix 2] In the reflectance spectrum of the OLED display device without laminating the optical laminate for an OLED display device, Rp1 is the maximum value at a wavelength of 380 to 455 nm, and the reflectance of the antireflection layer at the wavelength at Rp1. The optical laminate for an OLED display device according to Appendix 1, wherein [Rf1/Rp1] is 0.3 or less, where Rf1.
[Appendix 3] In the reflectance spectrum of the OLED display device without laminating the optical laminate for an OLED display device, Rp2 is the maximum value at a wavelength of 460 to 530 nm, and the reflectance of the antireflection layer at the wavelength at Rp2. 3. The optical laminate for an OLED display device according to appendix 1 or 2, wherein [Rf2/Rp2] is 0.12 or less, where Rf2.
[Appendix 4] In the reflectance spectrum of the OLED display device without laminating the optical laminate for an OLED display device, Rp1 is the maximum value at a wavelength of 380 to 455 nm, and the reflectance of the antireflection layer at the wavelength at Rp1. is Rf1, the maximum value at a wavelength of 460 to 530 nm is Rp2, and the reflectance of the antireflection layer at the wavelength in Rp2 is Rf2,
4. The optical laminate for an OLED display device according to any one of Appendices 1 to 3, wherein the sum of [Rf1/Rp1] and [Rf2/Rp2] is 0.42 or less.
[Appendix 5] The optical laminate for an OLED display device according to any one of Appendices 1 to 4, wherein the antireflection layer has a water contact angle of 100° or more.
[Appendix 6] The optical laminate for an OLED display device according to any one of Appendices 1 to 5, wherein the antireflection layer has a water contact angle of 90° or more after an eraser test.
[Appendix 7] The optical laminate for an OLED display device according to any one of Appendices 1 to 6, wherein the antireflection layer is made of an inorganic substance.
[Appendix 8] The optical laminate for an OLED display device according to any one of Appendices 1 to 7, comprising a hard coat layer, a base layer, and an adhesive layer on the side opposite to the viewing side of the antireflection layer. body.
[Appendix 9] The optical laminate for an OLED display device according to Appendix 8, wherein the pressure-sensitive adhesive layer has a haze value of 20 to 90%.
[Appendix 10] The optical laminate for an OLED display device according to Appendix 8 or 9, wherein the hard coat layer has a thickness of 2 to 10 μm.

100 OLED display panel 10R red OLED layer 10G green OLED layer 10B blue OLED layer 11a transparent electrode (cathode)
11b back electrode (anode)
12R red OLED element 12G green OLED element 12B blue OLED element 13 substrate 14 TFT layer 15 color filter 15R red colored layer 15G green colored layer 15B blue colored layer 16 black matrix layer W external light G reflected light C1 first optical path (direct light)
C2 second optical path (reflected light)
17 Bonding layer 200 OLED display device 20 Optical laminate 21 Adhesive layer or adhesive layer 22 Resin layer, glass layer or shock absorbing layer 23 Hard coat layer or anti-glare layer 24 Adhesive layer or adhesive layer 25 Resin layer, glass Layer or impact absorption layer 26 Adhesive layer or adhesive layer 27 Resin layer, glass layer or impact absorption layer 28 Hard coat layer or antiglare layer 29 Antireflection layer 300A OLED display device 30A Optical laminate 34A Adhesive layer or adhesive Layer 35A Glass layer 36A Adhesive layer having light scattering property 37A Resin layer 38A Hard coat layer 300B OLED display device 30B Optical laminate 31B Adhesive layer 32B Resin layer 33B Hard coat layer 34B Adhesive layer 35B Glass layer 36B Light scattering property 37B resin layer 38B hard coat layer 400A OLED display device 40A optical laminate 46A adhesive layer having light scattering properties 47A resin layer 48A hard coat layer 15A color filter 400B OLED display device 40B optical laminate 44B light scattering Adhesive layer having properties 45B Glass layer 46B Adhesive layer 47B Resin layer 48B Hard coat layer 15B Color filter 400C OLED display device 40C Optical laminate 41C Adhesive layer 42C Resin layer 43C Hard coat layer 44C Adhesive layer 45C Glass layer 46C Adhesive layer having light scattering property 47C Resin layer 48C Hard coat layer 15C Color filter 400D OLED display device 40D Optical laminate 41D Adhesive layer having light scattering property 42D Resin layer 43D Hard coat layer 44D Adhesive layer 45D Glass layer 46D Adhesive layer 47D Resin layer 48D Hard coat layer 15D Color filter 500A OLED display device 50A Optical laminate 56A Adhesive layer or adhesive layer 57A Resin layer 58A Antiglare layer 500B OLED display device 50B Optical laminate 54B Adhesive layer or adhesion Agent layer 55B Glass layer 56B Adhesive layer or adhesive layer 57B Resin layer 58B Antiglare layer 500C OLED display device 50C Optical laminate 51C Adhesive layer 52C Resin layer 53C Hard coat layer 54C Adhesive layer 55C Glass layer 56C Adhesive layer 57C resin layer 58C antiglare layer 600A OLED display device 60A optical laminate 66A adhesive layer or adhesive layer 67A resin layer 68A hard coat layer 69A antireflection layer 600B OLED display device 60B optical laminate 64B adhesive layer or adhesive layer 65B glass layer 66B adhesive layer or adhesive layer 67B resin layer 68B hard coat layer 69B antireflection layer 600C OLED display device 60C optical laminate 61C adhesive layer 62C resin layer 63C hard coat layer 64C adhesive layer 65C glass layer 66C adhesive Agent layer 67C Resin layer 68C Hard coat layer 69C Antireflection layer 700A OLED display device 70A Optical laminate 71A Adhesive layer 72A Resin layer 74A Adhesive layer 75A Glass layer 700B OLED display device 70B Optical laminate 71B Adhesive layer 72B Resin layer 74B Adhesive layer 75B Glass layer 76B Adhesive layer 77B Resin layer 78B Hard coat layer 700C OLED display device 70C Optical laminate 71C Adhesive layer 72C Resin layer 73C Hard coat layer 74C Adhesive layer 75C Glass layer 76C Adhesive layer 77C Resin Layer 78C Hard coat layer 800A OLED display device 80A Optical laminate 81A Adhesive layer 82A Transparent polyimide layer 83A Hard coat layer 800B OLED display device 80B Optical laminate 81B Adhesive layer 82B Transparent polyimide layer 83B Hard coat layer 84B Adhesive layer 87B Resin layer 88B Hard coat layer

Claims (10)

1. An optical laminate used in an OLED display device in which only an optical element having a degree of polarization of 95% or less is laminated on the viewing side of the OLED element,
   The optical laminate for an OLED display device, wherein the optical element has an antireflection layer at least on the viewing side.
2. In the reflectance spectrum of the OLED display device without laminating the optical laminate for an OLED display device, the maximum value at a wavelength of 380 to 455 nm was Rp1, and the reflectance of the antireflection layer at the wavelength in Rp1 was Rf1. 2. The optical laminate for an OLED display device according to claim 1, wherein [Rf1/Rp1] is 0.3 or less.
3. In the reflectance spectrum of the OLED display device without laminating the optical layered body for an OLED display device, the maximum value at a wavelength of 460 to 530 nm was Rp2, and the reflectance of the antireflection layer at the wavelength in Rp2 was Rf2. 3. The optical laminate for an OLED display device according to claim 2, wherein [Rf2/Rp2] is 0.12 or less.
4. The optical laminate for an OLED display device according to claim 3, wherein the sum of [Rf1/Rp1] and [Rf2/Rp2] is 0.42 or less.
5. The optical laminate for an OLED display device according to any one of claims 1 to 4, wherein the antireflection layer has a water contact angle of 100° or more.
6. The optical laminate for an OLED display device according to any one of claims 1 to 4, wherein the antireflection layer has a water contact angle of 90° or more after an eraser test.
7. The optical laminate for an OLED display device according to any one of claims 1 to 4, wherein the antireflection layer is composed of an inorganic material.
8. The optical laminate for an OLED display device according to any one of claims 1 to 4, comprising a hard coat layer, a substrate layer, and an adhesive layer on the side opposite to the viewing side of the antireflection layer.
9. The optical laminate for an OLED display device according to claim 8, wherein the pressure-sensitive adhesive layer has a haze value of 20 to 90%.
10. The optical laminate for an OLED display device according to claim 8, wherein the hard coat layer has a thickness of 2 to 10 µm.

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