JP2023126056A - Adhesive film for OLED display devices - Google Patents

Abstract

To provide an adhesive film capable of providing high weather resistance to an OLED device that does not use polarizing plates.SOLUTION: Provided is an adhesive film for use in an OLED display device having just an optical element with a polarization degree of 95% or less laminated on an OLED element on a viewer side, the adhesive film comprising at least one ultraviolet absorbent-containing layer as a layer constituting the optical element, and having a 380-nm transmittance of 20% or less.SELECTED DRAWING: Figure 9

Description

The present invention relates to an adhesive film for OLED display devices. More specifically, the present invention relates to an adhesive film used in an OLED display device that does not use a polarizing plate.

OLED (Organic light emitting diode) display devices have advantages in display performance compared to liquid crystal display devices, such as higher visibility, less viewing angle dependence, and faster response speed. Further, since the OLED display device does not use a backlight, it is advantageous for making it thinner, and it can also be used as a foldable device that can be flexibly curved or folded.

An OLED display device typically has an OLED element in which an anode, an OLED layer including a light emitting layer, and a cathode are stacked in this order. The electrodes (anode or cathode) of OLED elements are made of transparent conductive materials with a high refractive index such as ITO or metal materials with high reflectance, so external light is reflected by the electrodes, resulting in decreased contrast and internal reflection. A problem of reflection may occur, and the display performance of the OLED display device may deteriorate.

In order to suppress the adverse effects of external light reflection, 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 an OLED display device (for example, Patent Document 1). Such a circularly polarizing plate also has the function of blocking ultraviolet rays contained in external light and preventing deterioration of OLED elements due to ultraviolet rays. Furthermore, due to the mechanical properties of the circularly polarizing plate itself, it also has the function of absorbing external impact and preventing damage to the OLED display device.

However, when a circularly polarizing plate is used, the light utilization efficiency (i.e., lighting rate) is poor due to absorption by the polarizing plate, resulting in low brightness. Increasing the emission intensity of an OLED element to obtain desired brightness increases power consumption and shortens the life of the OLED element. In addition, the polarizing plate has a thickness of about 0.15 mm if an adhesive layer for pasting is included, which is disadvantageous for making the OLED display device thinner. Furthermore, since circularly polarizing plates are expensive, there is also the problem of increased manufacturing costs.

As an alternative to a circularly polarizing plate, by placing a color filter on the viewing side of the OLED element and aligning it so that the color filters of the same color as the OLED layer emit light face each other, it is possible to prevent the reflection of external light. , a method for improving the luminous intensity of an OLED element has been proposed (for example, Patent Document 2).

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

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

Japanese Patent Application Publication No. 2003-332068 Japanese Patent Application Publication No. 2018-112715 Japanese Patent Application Publication No. 2015-207377

However, such an OLED display device that does not use a polarizing plate has a problem in that the weather resistance of the OLED element is low. The reason for this is that, compared to the case where a polarizing plate is used, the ultraviolet absorption function of the color filter is not sufficient, so the OLED element is more likely to deteriorate over time due to ultraviolet rays contained in external light.

Therefore, an object of the present invention is to provide an adhesive film that can impart high weather resistance to an OLED display device that does not use a polarizing plate.

As a result of intensive studies to achieve the above object, the present inventors used an adhesive film for an OLED display device that has at least one layer containing an ultraviolet absorber and has a 380 nm transmittance adjusted to a specific range. The present invention was completed based on the discovery that an OLED display device exhibits sufficient weather resistance even when the OLED display device does not use a polarizing plate.

That is, the present invention provides an adhesive film 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, and a layer constituting the optical element contains an ultraviolet absorber. Provided is an adhesive film for an OLED display device, which has at least one layer containing the present invention and has a transmittance of 20% or less at 380 nm.

The adhesive film of the present invention can impart high weather resistance to an OLED display device that does not use a polarizing plate.

1 is a schematic cross-sectional view showing one embodiment of an OLED display panel used in an OLED display device of the present invention. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device in which an optical laminate of the present invention is laminated. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device in which an optical laminate of the present invention is laminated. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device in which an optical laminate of the present invention is laminated. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device in which an optical laminate of the present invention is laminated. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device in which an optical laminate of the present invention is laminated. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device in which an optical laminate of the present invention is laminated. 1 is a schematic cross-sectional view showing an embodiment of an OLED display device in which an optical laminate of the present invention is laminated. (a) It is a schematic sectional view showing one embodiment of the adhesive film of the present invention. (b) A schematic cross-sectional view showing an embodiment of an OLED display device using the adhesive film of the present invention.

The present invention provides an adhesive film for an OLED display device. An adhesive film for an OLED display device of the present invention, an “adhesive film of the present invention”, an optical laminate for an OLED display device of the present invention, an “optical laminate of the present invention”, an OLED display using the optical laminate of the present invention The device may be referred to as the "OLED display device of the present invention", and the optical element constituting the optical laminate of the present invention may be referred to as the "optical element of the present invention". The optical laminate of the present invention is a laminate obtained by removing the OLED display panel from the OLED display device of the present invention, and includes the adhesive film of the present invention.

In the OLED display device of the present invention, only optical elements having a degree of polarization of 95% or less are laminated on the viewing side of the OLED element on the OLED display panel. "Only optical elements with a polarization degree of 95% or less are laminated on the viewing side of the OLED element" means that optical elements with a polarization degree of over 95% are not included in the optical elements on the viewing side of the OLED element. do. "Optical elements with a degree of polarization exceeding 95%" include, but are not limited to, 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 determined by the following formula based on parallel transmittance Tp and cross transmittance Tc measured using an ultraviolet-visible spectrophotometer and corrected for visibility.
Degree of polarization (%) = {(Tp-Tc)/(Tp+Tc)}1/2×100

Since the OLED display device of the present invention does not include a polarizing plate on the viewing side of the OLED element, absorption of light emitted from the OLED element by the polarizing plate is suppressed, improving the lighting rate and saving power consumption. This leads to longer life of the element. Further, by not using a polarizing plate, it is possible to make the device thinner, and manufacturing costs can be reduced.

The adhesive film of the present invention is characterized in that it has at least one layer containing an ultraviolet absorber and has a 380 nm transmittance of 20% or less. It is preferable that the adhesive film of the present invention has the above-mentioned characteristics in that the weather resistance in an OLED display device is improved.

In the adhesive film of the present invention, the adhesive layer may be a layer containing an ultraviolet absorber. That is, it may have an adhesive layer containing an ultraviolet absorber. The adhesive film of the present invention may have a resin layer in addition to the above-mentioned adhesive layer, and the resin layer may be a layer containing an ultraviolet absorber. When the adhesive film of the present invention has a resin layer, it is preferable from the viewpoint of improving impact resistance. Furthermore, the adhesive film of the present invention may have an optical element other than the above-mentioned adhesive layer and resin layer that are laminated on the OLED display device of the present invention as a configuration of the adhesive film. In the adhesive film of the invention and the optical laminate of the invention, at least one of the adhesive layers of the invention may be an adhesive layer with a high refractive index, and all the adhesive layers of the invention may have a high refractive index. It may also be a refractive index adhesive layer.

The adhesive film of the present invention preferably has an adhesive layer containing an ultraviolet absorber and a resin layer containing an ultraviolet absorber, since the weather resistance is further improved. In this case, the amount of ultraviolet absorber required for each layer is small, and it is also preferable because the originally desired characteristics of the layer are less likely to be impaired.

The 380 nm transmittance of the adhesive film of the present invention is preferably 15% or less, more preferably 10% or less, more preferably 7% or less, more preferably 5% or less, more preferably 4% or less, and more preferably It is 3% or less, more preferably 2% or less, particularly preferably 1% or less. The lower limit of the 380 nm transmittance is 0%. Note that the method for measuring the 380 nm transmittance is not particularly limited, but it can be measured, for example, using a spectrophotometer U4100 (manufactured by Hitachi High-Technologies, Inc.).

In addition, in this specification, "adhesive film" shall include the meaning of "adhesive sheet" and "adhesive tape." That is, the adhesive film of the present invention may be an adhesive sheet or an adhesive tape having a sheet-like or tape-like form. The adhesive film of the present invention is an element for forming the optical laminate of the present invention, and includes at least the above-mentioned high refractive index adhesive layer.

The adhesive film of the present invention may be a so-called "base material-less type" adhesive film that does not have a base material (corresponding to a "resin layer" described below), or a type of adhesive film that has a base material. It's okay. Note that in this specification, a "substrate-less type" adhesive film may be referred to as a "substrate-less adhesive film," and a type of adhesive film that has a base material may be referred to as a "adhesive film with a base material." be. Examples of the base material-less adhesive film include a double-sided adhesive sheet consisting of only an adhesive layer. Further, examples of the adhesive film with a base material include a single-sided adhesive film having an adhesive layer on one side of the base material, a double-sided adhesive film having adhesive layers on both sides of the base material, and the like. The above-mentioned "substrate" refers to a support, and when the adhesive film of the present invention is used (attached) to an adherend, the "base material" mentioned above is the part that is attached to the adherend together with the adhesive layer. be. A release liner that is peeled off when the adhesive film is used (applied) is not included in the base material.

Hereinafter, each structure related to the adhesive film of the present invention will be explained.

(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 stacked in this order. The optical laminate of the present invention is laminated on the viewing side of the OLED elements of an OLED display panel.

Hereinafter, one embodiment of an OLED display panel constituting an OLED display device of the present invention will be described 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 an OLED display panel.

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

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

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

The transparent electrode 11a is either a cathode or an anode, and 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 the material for forming the transparent electrode 11a.

The back electrode 11b functions as a counter electrode to the transparent electrode 11a. The back electrode 11b is either an anode or a cathode, but 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 is capable of reflecting 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 for the bonding layer 17, any material used in general OLED display devices may be used, and for example, a photocurable resin such as a photosensitive polyimide resin, a thermosetting resin, or the like may be used.

In addition to the configuration shown in FIG. 1, the OLED display panel 100 includes configurations that an OLED display panel has, such as a hole injection layer, a hole transport layer, an electron transport layer, a sealing layer, and a touch sensor panel. (not shown).

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

Since the green and blue components of the external light W are absorbed by the red colored layer 15R, the light intensity is reduced to 1/3. Further, since the reflected light G passes through the red colored layer 15R and the red OLED layer 10R again, this causes attenuation. Further, since the reflected light G has a red color, the red light emitted from the OLED layer 10R can be enhanced. Similarly, when external light W is incident on the green colored layer 15G and the blue colored layer 15B, green light and blue light can be respectively enhanced. Therefore, by using a color filter in combination with an OLED display panel, it is possible to significantly suppress reflection of external light and improve the luminous intensity of the OLED element even when a polarizing plate is not used for antireflection.

However, color filters are generally prone to interference unevenness due to their regular two-dimensional structure.
In addition, color filters have a problem in that reflection is likely to occur at the interface and the rate of light taken in from the OLED element is reduced.
In addition, color filters do not have sufficient ultraviolet absorption function compared to the case of using polarizing plates, and OLED elements tend to deteriorate over time due to ultraviolet rays contained in external light (i.e., have low weather resistance). be.
Additionally, color filters have a problem in that they do not have a sufficient impact absorption function compared to the case where polarizing plates are used.

Further, the OLED display panel 100 of this embodiment has a microcavity structure. Light generated 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" emitted directly from the OLED layers 10R, 10G, 10B toward the transparent electrode 11a, and "direct light" emitted from the OLED layers 10R, 10G, 10B toward the back electrode 11b, Both components of the reflected light that is reflected by the electrode 11b and then directed toward the transparent electrode 11a are included. In other words, some of the light emitted from the OLED layers 10R, 10G, and 10B does not proceed toward the back electrode 11b. The first optical path C1 travels toward the transparent electrode 11a side and is emitted to the outside through the transparent electrode 11a, and the remaining part of the light emitted from the OLED layers 10R, 10G, and 10B travels toward the back electrode 11b side and exits from the back surface. After being reflected by the electrode 11b, a second optical path C2 is formed which is emitted to the outside through the OLED layers 10R, 10B, 10B and the transparent electrode 11a.The interference between the direct light and the reflected light causes the light to correspond to each color. The OLED layers 10R, 10G, and 10B have different thicknesses so that the light components strengthen each other.In other words, the back electrode (positive electrode) 11b and the transparent The thicknesses of the OLED layers 10R, 10G, and 10B are different in order to match the optical path length with the electrode (negative electrode) 11a and extract the strongest light from each color. The thickness of the blue wavelength OLED layer 10B is designed to be thin, and the thickness of 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 the optical path length increases. By resonating and emphasizing only the light of the matching wavelength, and weakening the light of other wavelengths with shifted optical path lengths, the spectrum of the light extracted to the outside becomes steep and high intensity, improving brightness and color purity. improves.
Although an OLED display panel with a microcavity structure has the excellent effect of improving brightness and color purity, it has the problem of strong viewing angle dependence (narrow viewing angle) due to its steep spectrum. may occur. For this reason, when an image is viewed from an angle during image display, a color shift may occur that makes the image appear to be a different color 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 at least an adhesive layer. The optical element of the present invention is further selected from an adhesive layer, a resin layer, a glass layer, a hard coat layer, an antireflection layer, an antiglare layer, an intermediate layer (compatible layer), a shock absorption layer, an antistatic layer, etc. It may include at least one layer. However, the optical element of the present invention does not include anything with a degree of polarization exceeding 95%, such as a polarizing plate.

(Adhesive layer)
An adhesive layer is a layer that has adhesive properties at room temperature and adheres to an adherend with light pressure.Even when an adherend that has been attached to the adhesive layer is peeled off, the adhesive layer remains practical. A substance that maintains a strong adhesive force.

The adhesive layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "adhesive layer of the present invention") is used from the viewpoint of preventing interface reflection and improving the lighting rate of light emitted from the OLED element. , preferably has a high refractive index. The refractive index of the adhesive layer of the present invention is preferably 1.57 or more, more preferably 1.575 or more, even more preferably 1.580 or more, particularly preferably 1.585 or more, even more preferably 1.590. or more, and may be 1.595 or more.

The refractive index of the adhesive layer of the present invention can be adjusted by the types and contents of the aromatic ring-containing monomer, high refractive index organic material, and high refractive index inorganic material described below.

Although the adhesive layer of the present invention is not particularly limited, it preferably has light scattering properties (a function of scattering light) from the viewpoint of efficiently reducing color shift and interference unevenness of an OLED display device. When the adhesive layer of the present invention has light scattering properties, it is preferable that the adhesive layer contains light scattering fine particles dispersed therein.

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, color shift and interference unevenness of the OLED display device can be reduced, and the OLED display device caused by light scattering can be reduced. From the viewpoint of suppressing image blur, it is preferable that the distance between the adhesive layer having light scattering properties and the color filter is 700 μm or less. From the viewpoint of suppressing image blurring of an OLED display device caused by light scattering, the distance between the adhesive layer having light scattering properties and the color filter is more preferably 600 μm or less, and 500 μm or less. is more preferred, and most preferred is 0 μm, that is, the adhesive layer having light scattering properties is in direct contact with the color filter.

The distance between the adhesive layer having light scattering properties and the color filter is the distance (μm) between the surface of the adhesive layer in the color filter direction and the surface of the color filter in the adhesive layer direction. If 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 (if there are two or more layers, the total) corresponds to

The haze value of the adhesive layer of the present invention is not particularly limited, but from the viewpoint of efficiently reducing color shifts and interference unevenness of OLED display devices, it is preferably 20% or more, more preferably 30% or more, and still more preferably 40% or more. % or more, particularly preferably 50% or more. Further, from the viewpoint of suppressing image blurring of an OLED display device and displaying a high-definition image, the haze value of the adhesive layer of the present invention is preferably 90% or less, more preferably 80% or less, and 70% or less. More preferred.

The total light transmittance of the adhesive layer of the present invention is not particularly limited, but from the viewpoint of ensuring the brightness of the OLED display device, the total light transmittance is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, Particularly preferably, it is 90% or more. Further, the upper limit of the total light transmittance of the 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 adhesive layer of the present invention can be measured by the methods specified in JIS 7136 and JIS 7361, respectively, and depend on the type and thickness of the adhesive layer and the type of light-scattering fine particles described below. It can be controlled by adjusting the amount and the amount of the compound.

The thickness of the adhesive layer of the present invention is preferably 10 to 100 μm, more preferably 15 to 90 μm, and 20 to 80 μm from the viewpoint of efficiently reducing color shift and interference unevenness of an OLED display device. The thickness is more preferably 25 to 70 μm.

The light-scattering fine particles have an appropriate refractive index difference with the pressure-sensitive adhesive layer and impart light-scattering properties to the pressure-sensitive adhesive layer. It is preferable that the pressure-sensitive adhesive layer contains light-scattering fine particles because this imparts light-scattering performance. Examples of the light-scattering fine particles include inorganic fine particles and polymer fine particles. Examples of the material for the inorganic fine particles include silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, talc, and titanium dioxide. Examples of the material of the polymer fine particles include silicone resin, acrylic resin, methacrylic resin (eg, polymethyl methacrylate), polystyrene resin, polyurethane resin, melamine resin, polyethylene resin, and epoxy resin. The light-scattering fine particles are preferably polymeric fine particles, and in particular, fine particles composed of silicone resin (for example, Tospear series manufactured by Momentive Performance Materials Japan) have excellent dispersion in the adhesive layer. An adhesive layer with excellent scattering performance that has a suitable refractive index difference with respect to the adhesive layer, exhibits uniform haze in the plane, and reduces color shift and interference unevenness in OLED display devices. It is suitable for this purpose. The shape of the light-scattering fine particles may be, for example, spherical, flat, or irregular. The light-scattering fine particles may be used alone or in combination of two or more types.

The 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, and especially from the viewpoint of imparting appropriate light-scattering properties to the adhesive layer. Preferably it is 0.25 μm or more. In addition, the 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 8 μm, from the viewpoint of preventing the haze value from becoming too high and displaying a high-definition image. It is as follows. The average particle diameter can be measured using, for example, a Coulter counter.

The refractive index of the light scattering fine particles is preferably 1.2 to 5, more preferably 1.25 to 4.5, and may be 1.3 to 4, or 1.35 to 3.

The absolute value of the refractive index difference between the light-scattering fine particles and the adhesive layer (the adhesive layer excluding the light-scattering fine particles) is a point of view for efficiently reducing color shifts and interference unevenness in OLED display devices. , preferably 0.001 or more, more preferably 0.01 or more, even more preferably 0.02 or more, particularly preferably 0.03 or more, and may be 0.04 or more, or 0.05 or more. . Further, the absolute value of the refractive index difference between the light-scattering fine particles and the adhesive layer is preferably 5. or less, more preferably 4 or less, still more preferably 3 or less.

From the viewpoint of imparting appropriate light scattering properties to the adhesive layer, the content of light-scattering fine particles in the adhesive layer is preferably 0.01 parts by weight based on 100 parts by weight of the adhesive constituting the adhesive layer. The amount is at least 0.05 parts by weight, more preferably at least 0.1 parts by weight, particularly preferably at least 0.15 parts by weight. In addition, the content of light-scattering fine particles is adjusted to 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 a high-definition image. On the other hand, it is preferably 80 parts by weight or less, more preferably 70 parts by weight or less.

The variation ratio of the refractive index before and after humidification of the adhesive layer of the present invention is not particularly limited, but it can prevent interface reflection and stably improve the lighting rate of light emitted from the OLED element even in a high temperature and high humidity environment. From this point of view, it is preferably 0.05 or less, preferably 0.04 or less, more preferably 0.02 or less, particularly preferably 0.01 or less.

The variation ratio of the refractive index before and after humidification of the adhesive layer of the present invention can be calculated using the following formula after storing the 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. It is.
Change ratio of refractive index 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 index inorganic material described below, the type of adhesive constituting the adhesive layer, monomer composition, degree of crosslinking, It can be adjusted depending on the thickness etc.

The adhesive constituting the adhesive layer of the present invention is not particularly limited, but includes, for example, an acrylic adhesive, a rubber adhesive, a vinyl alkyl ether adhesive, a silicone adhesive, a polyester adhesive, and a polyamide adhesive. Examples include adhesives, urethane adhesives, fluorine adhesives, and epoxy adhesives. Among these, acrylic pressure-sensitive adhesives are preferred as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer in terms of transparency, adhesiveness, weather resistance, cost, and ease of designing the pressure-sensitive adhesive. That is, the adhesive layer of the present invention is preferably an acrylic adhesive layer made of an acrylic adhesive. The pressure-sensitive adhesives can be used alone or in combination of two or more.

The acrylic 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 an alkyl (meth)acrylic acid ester as a monomer component constituting the polymer. Note that the acrylic polymers can be used alone or in combination of two or more.

The adhesive composition forming the adhesive layer of the present invention may be in any form. For example, the adhesive composition may be of an emulsion type, a solvent type (solution type), an active energy ray-curable type, a heat melt type (hot melt type), or the like. Among these, solvent-based and active energy ray-curable adhesive compositions are preferred from the viewpoint of productivity and the ease of obtaining an adhesive layer with excellent optical properties and appearance.

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

The adhesive composition (acrylic adhesive composition) forming the acrylic adhesive layer may be, for example, an acrylic adhesive composition containing an acrylic polymer as an essential component, or a monomer 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. Examples of the former include so-called solvent-type acrylic adhesive compositions. Examples of the latter include so-called active energy ray-curable acrylic adhesive compositions. The above-mentioned "monomer mixture" means a mixture containing monomer components constituting a polymer. The above-mentioned "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 are partially polymerized. do.

The acrylic polymer is a polymer composed (formed) of an acrylic monomer as an essential monomer component. The acrylic polymer is preferably a polymer composed (formed) of (meth)acrylic acid alkyl ester as an essential monomer component. That is, the acrylic polymer preferably contains an alkyl (meth)acrylate ester as a structural unit. In the present specification, "(meth)acrylic" refers to "acrylic" and/or "methacrylic" (either or both of "acrylic" and "methacrylic"), and the same applies to the others. In addition, the said acrylic polymer is comprised from 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 alkyl ester 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 includes, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, ( Isopropyl (meth)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) ) Isononyl acrylate, (meth)decyl acrylate, (meth)isodecyl acrylate, (meth)undecyl acrylate, (meth)dodecyl acrylate, (meth)tridecyl acrylate, (meth)tetradecyl acrylate, (meth) Pentadecyl acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), isostearyl (meth)acrylate, nonadecyl (meth)acrylate, (meth)acrylic Examples include (meth)acrylic acid alkyl esters having a linear or branched alkyl group having 1 to 20 carbon atoms, such as eicosyl acid. Among these, 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. 2-ethylhexyl acrylate (2EHA) and isostearyl acrylate (ISTA) are more preferred. Moreover, the (meth)acrylic acid alkyl ester having a linear or branched alkyl group can be used alone or in combination of two or more types.

The proportion of the (meth)acrylic acid alkyl ester in all 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). It is 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. Note that the copolymerizable monomers can be used alone or in combination of two or more types.

The copolymerizable monomer is not particularly limited, but it is possible to obtain a pressure-sensitive adhesive layer with a high refractive index, suppress reflection at the interface with the OLED display panel, and improve the light absorption rate from the OLED element. Preferred examples include monomers 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 the molecule is a monomer (monomer) having at least one aromatic ring in the molecule (in 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."

As the 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, one type of such compounds can be used alone or two or more types can be used in combination.

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

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 aromatic rings may be, for example, 12 or less, preferably 8 or less, more preferably 6 or less, and 5 or less. It may be less than or equal to 4, it may be less than or equal to 3, and it may be less than or equal to 2.

The aromatic ring possessed by the compound used as the aromatic ring-containing monomer includes, for example, a benzene ring (it can be a benzene ring that forms part of a biphenyl structure or a fluorene structure); a naphthalene ring, an indene ring, an azulene ring, an anthracene ring, and a phenanthrene ring. It may be a carbocyclic ring such as a condensed 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, and a thiazole ring. It may be a ring or a heterocyclic ring such as a thiophene ring. The heteroatoms included as ring constituent atoms in the heterocycle may be, for example, one or more heteroatoms selected from the group consisting of nitrogen, sulfur, and oxygen. The heteroatoms constituting 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 a carbocyclic 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, a glycidyloxy group. Examples include, but are not limited to. In a substituent containing carbon atoms, the number of carbon atoms contained in the substituent is preferably 1 to 4, more preferably 1 to 3, and may be 1 or 2, for example. The aromatic ring has no substituent on the ring constituent atoms or has one or more substituents selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom (for example, a bromine atom). obtain. Note that the phrase "the aromatic ring of the aromatic ring-containing monomer has a substituent on its ring-constituting atoms" means that the aromatic ring has a substituent other than the substituent having an ethylenically unsaturated group.

The aromatic ring and the ethylenically unsaturated group may be bonded directly 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 a hydroxyl group. It may be a group containing one or more structures selected from a group such as a hydroxyalkylene group (for example, a hydroxyalkylene group), an oxy group (-O- group), a thiooxy group (-S- group), and the like. An aromatic structure in which an aromatic ring and an ethylenically unsaturated group are bonded directly or via a linking group selected from the group consisting of an alkylene group, an oxyalkylene group, and a poly(oxyalkylene) group. Ring-containing monomers can be preferably employed. The number of carbon atoms in the alkylene group and the oxyalkylene group is preferably 1 to 4, more preferably 1 to 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 to 3.

Examples of compounds that can be preferably employed as the aromatic ring-containing monomer 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 each be used singly or in combination of two or more. One or more aromatic ring-containing (meth)acrylates and one 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. It is preferable that the ratio is 30% by weight or more because it tends to make it easier to obtain a higher refractive index. 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, 75% by weight or more, 80% by weight or more, or 85% by weight or more. It may be 90% by weight or more, or 95% by weight or more. In addition, the upper limit of the proportion of the aromatic ring-containing monomer is preferably 99% by weight or less, more preferably 98% by weight or less, from the viewpoint of obtaining an adhesive layer with appropriate flexibility and an adhesive layer with excellent transparency. % or less, more preferably 97% by weight or less, and may be 96% by weight or less. Further, 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 more emphasis is placed on adhesive properties and/or optical properties, 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 carbocycles) in one molecule can be preferably employed since it is easy to obtain a high refractive index effect. Examples of monomers having two or more aromatic rings in one molecule (hereinafter also referred to as "monomers containing multiple aromatic rings") include monomers having a structure in which two or more non-fused aromatic rings are bonded via a linking group. , a monomer having a structure in which two or more non-fused aromatic rings are chemically bonded directly (i.e., without intervening other atoms), a monomer having a fused aromatic ring structure, a monomer having a fluorene structure, a monomer having a dinaphthothiophene structure , monomers having a dibenzothiophene structure, and the like. The monomer containing multiple aromatic rings can be used alone or in combination of two or more.

The linking group is, for example, an oxy group (-O-), a thiooxy group (-S-), an oxyalkylene group (for example, a -O-(CH ₂ ) _n - group, where n is 1 to 3, preferably 1). , thiooxyalkylene groups (e.g. -S-(CH ₂ ) _n - group, where n is 1 to 3, preferably 1), linear alkylene groups (i.e. -(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 halogenated or completely halogenated group. From the viewpoint of flexibility of the adhesive, preferred examples of the linking group include an oxy group, a thiooxy group, an oxyalkylene group, and a straight-chain alkylene group. 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 (for example, m-phenoxybenzyl (meth)acrylate), thiophenoxybenzyl (meth) Examples include 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, biphenyl structure-containing (meth)acrylate, triphenyl structure-containing (meth)acrylate, vinyl group-containing biphenyl, or the like. Specific examples include o-phenylphenol (meth)acrylate, biphenylmethyl (meth)acrylate, and the like.

Examples of the monomer having the fused aromatic ring structure include naphthalene ring-containing (meth)acrylate, anthracene ring-containing (meth)acrylate, vinyl group-containing naphthalene, vinyl group-containing anthracene, and the like. 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, -(4-methoxy-1-naphthoxy)ethyl (meth)acrylate and the like.

Specific examples of the monomer having the fluorene structure include 9,9-bis(4-hydroxyphenyl)fluorene (meth)acrylate, 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (meth)acrylate etc. In addition, since the monomer having a fluorene structure includes a structural part 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 the dinaphthothiophene structure include (meth)acryloyl group-containing dinaphthothiophene, vinyl group-containing dinaphthothiophene, (meth)allyl group-containing dinaphthothiophene, and the like. Specific examples include (meth)acryloyloxymethyl dinaphthothiophene (for example, a compound having a structure in which CH ₂ CH(R ¹ )C(O)OCH ₂ - is bonded to the 5th or 6th position of the dinaphthothiophene ring. , R ¹ is a hydrogen atom or a methyl group), (meth)acryloyloxyethyldinaphthothiophene (for example, CH ₂ CH(R ¹ )C(O) at the 5th or 6th position of the dinaphthothiophene ring A compound with a structure in which OCH(CH ₃ )- or CH ₂ CH(R ¹ )C(O)OCH ₂ CH ₂ - is bonded. Here, R ¹ is a hydrogen atom or a methyl group), vinyldinaphthothiophene (For example, a compound 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 monomers having a dinaphthothiophene structure are included in the concept of monomers having a fused aromatic ring structure because they include a naphthalene structure and also because they have a structure in which a thiophene ring and two naphthalene structures are condensed. Ru.

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

As the aromatic ring-containing monomer, a monomer having one aromatic ring (preferably a carbon ring) in one molecule may be used. A monomer having one aromatic ring in one molecule can be useful, for example, in improving the flexibility of the adhesive, adjusting the adhesive properties, and improving transparency. 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 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, and phenoxypropyl (meth)acrylate. , phenoxybutyl (meth)acrylate, cresyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, chlorobenzyl (meth)acrylate, and other carbon aromatic ring-containing (meth)acrylates; 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-vinylpyridine, N-vinylpyrimidine, Examples include 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, monomers having a structure in which an oxyethylene chain is interposed between the ethylenically unsaturated group and the aromatic ring in the various aromatic ring-containing monomers described above may be used. A monomer in which an oxyethylene chain is interposed between an ethylenically unsaturated group and an aromatic ring can be understood as an ethoxylated product of the original monomer. The number of repeating oxyethylene units (-CH ₂ CH ₂ O-) in the oxyethylene chain is typically 1 to 4, preferably 1 to 3, more preferably 1 to 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. Examples include di(meth)acrylate.

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 facilitating the realization of 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, and 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 a monomer containing multiple aromatic rings. That is, as the aromatic ring-containing monomer, only one or more aromatic ring-containing monomers may be used. Further, for example, in consideration of the balance between high refractive index and 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, and may be 98% by weight. It may be less than 90% by weight, it may be less than 80% by weight, and it may be less than 65% by weight. 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, may be 50% by weight or less, may be 25% by weight or less, and may be 10% by weight or less. It may be less than %. An embodiment may also be implemented in which the content of the monomer containing multiple aromatic rings in the aromatic ring-containing monomer is less than 5% by weight. 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. Although not particularly limited, it 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 easily 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, more than 50% by weight, more than 70% by weight, more than 75% by weight. It may be 85% by weight or more, 90% by weight or more, or 95% by weight or more. Further, the upper limit of the proportion of the aromatic ring-containing monomer is preferably 99% by weight or less, more preferably 98% by weight or less, from the viewpoint of achieving both a high refractive index and adhesive properties and/or optical properties in a well-balanced manner. More preferably, it is 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, may be 80% by weight or less, It may be 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. It may be 5% by weight or less.

The copolymerizable monomer is not particularly limited, but from the viewpoints of suppressing clouding in high humidity environments, improving durability, compatibility with various additives such as ultraviolet absorbers, and transparency, Preferred examples include monomers having a nitrogen atom and monomers having a hydroxyl group in the molecule. That is, the acrylic polymer preferably contains a monomer having a nitrogen atom in the molecule as a structural unit. Further, 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 the molecule is a monomer (monomer) having at least one nitrogen atom in the molecule (in one molecule). In this specification, the above-mentioned "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 preferred examples include cyclic nitrogen-containing monomers, (meth)acrylamides, and the like. Note that 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 a vinyl group, and has a cyclic nitrogen structure. The cyclic nitrogen structure preferably has a nitrogen atom within the cyclic structure.

Examples of the cyclic nitrogen-containing monomer include N-vinyl cyclic amide (lactam vinyl monomer), vinyl monomer having a nitrogen-containing heterocycle, and the like.

（式（１）中、Ｒ¹は２価の有機基を示す） Examples of the N-vinyl cyclic amide include N-vinyl cyclic amide 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. 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 the vinyl monomer having a nitrogen-containing heterocycle include acrylic monomers having a nitrogen-containing heterocycle such as a morpholine ring, a piperidine ring, a pyrrolidine ring, and a piperazine ring.

The vinyl monomer having a nitrogen-containing heterocycle is not particularly limited, but includes, for example, (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, etc. .

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

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)acrylamide also includes (meth)acrylamide 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, and N,N-diisopropyl. Examples include (meth)acrylamide, N,N-di(n-butyl)(meth)acrylamide, and N,N-di(t-butyl)(meth)acrylamide.

Further, the (meth)acrylamides 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, Examples include N-(4-hydroxybutyl)(meth)acrylamide and N-methyl-N-2-hydroxyethyl(meth)acrylamide.

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

Examples of the cyclic nitrogen-containing monomer and the nitrogen atom-containing monomer other than 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. The imide group-containing monomers include maleimide monomers (for example, N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide, etc.), itaconimide monomers (for example, N-methylitaconimide, N- ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itaconimide, N-lauryl itaconimide, N-cyclohexy itaconimide, etc.), succinimide monomers (e.g. N-(meth)acryloyl oxymethylene succinimide, N-(meth)acryloyl-6-oxyhexamethylene succinimide, N-(meth)acryloyl-8-oxyoctamethylene succinimide, etc.). Examples of the isocyanate group-containing monomer include 2-(meth)acryloyloxyethyl isocyanate.

Among these, the nitrogen atom-containing monomer is preferably a cyclic nitrogen-containing monomer, and more preferably 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 proportion 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 still more preferably 5% by weight or more. It is preferable that the ratio is 1% by weight or more, since it is possible to further improve the suppression of clouding and durability in a high-humidity environment. Further, the upper limit of the proportion of the nitrogen atom-containing monomer is preferably 30% by weight or less, more preferably 25% by weight or less, from the viewpoint of obtaining an adhesive layer with appropriate flexibility and an adhesive layer with excellent transparency. % or less, more preferably 20% by weight or less.

The monomer having a hydroxyl group in the molecule is a monomer having at least one hydroxyl group in the molecule (in one molecule), and is a monomer having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Preferred examples include those having a functional group and a hydroxyl group. However, the monomer having 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 above-mentioned "monomer having a hydroxyl group in the molecule" may be referred to as a "hydroxyl group-containing monomer." Note that the hydroxyl group-containing monomers can be used alone or in combination of two or more.

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 compounds such as 6-hydroxyhexyl meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl) (meth)acrylate Examples include meth)acrylic acid ester; vinyl alcohol; allyl alcohol.

Among these, the hydroxyl group-containing monomer is preferably a hydroxyl group-containing (meth)acrylic 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, from the viewpoint of suppressing clouding in a high humidity environment and improving durability, it is preferably 0.5% by weight or more, more preferably 0.8% by weight or more, and even more preferably 1% by weight. % or more. Further, the upper limit of the proportion 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 an adhesive layer with appropriate flexibility and an adhesive layer with excellent transparency. It is 25% by weight or less, more preferably 15% by weight or less.

The total proportion of the nitrogen atom-containing monomer and the hydroxyl group-containing monomer in all the monomer components (100% by weight) constituting the acrylic polymer is not particularly limited, but it can be used to suppress 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. Further, the upper limit of the total ratio is preferably 50% by weight or less, more preferably 40% by weight or less, from the viewpoint of obtaining an adhesive layer with appropriate flexibility and excellent transparency. % or less, more preferably 35% by weight or less.

Copolymerizable monomers other than the nitrogen atom-containing monomer and the hydroxyl group-containing monomer 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. Note that the alicyclic structure-containing monomers can be used alone or in combination of two or more.

The alicyclic structure in the alicyclic structure-containing monomer is a cyclic hydrocarbon structure, and preferably has 5 or more carbon atoms, more preferably 6 to 24 carbon atoms, even more 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. Examples include acrylic monomers. In addition, in the following formula (4), the bonding position between the cyclohexyl ring connected by a line and the structural formula in parentheses is not particularly limited. 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. Although not particularly limited, it is preferably 10% by weight or more from the viewpoint of improving durability. Further, the upper limit of the proportion of the alicyclic structure-containing monomer is preferably 50% by weight or less, more preferably 40% by weight or less, still more preferably 30% by weight or less, from the viewpoint of obtaining an adhesive layer with appropriate flexibility. It is.

Furthermore, examples of copolymerizable monomers include 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, and 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, Examples include allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, and urethane acrylate. Note that the polyfunctional monomers can be used alone or in combination of two or more types.

When the acrylic polymer contains the polyfunctional monomer as a monomer component constituting the polymer, the proportion 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).

Furthermore, examples of the copolymerizable monomer include (meth)acrylic acid alkoxyalkyl ester. The (meth)acrylic acid alkoxyalkyl ester is not particularly limited, but includes, for example, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, ( Examples include 3-methoxypropyl meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate. Among these, the (meth)acrylic acid alkoxyalkyl ester is preferably an acrylic acid alkoxyalkyl ester, and more preferably 2-methoxyethyl acrylate (MEA). In addition, the said (meth)acrylic acid alkoxyalkyl ester can be used individually or in combination of 2 or more types.

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 to the (meth)acrylic acid alkoxyalkyl ester is: Although not particularly limited, [former:latter] (weight ratio) preferably exceeds 100:0 and is 25:75 or less, more preferably exceeds 100:0 and is 50:50 or less.

In addition, examples of the copolymerizable monomer include carboxyl group-containing monomers, epoxy group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, (meth)acrylic acid esters having aromatic hydrocarbon groups, Examples include vinyl esters, aromatic vinyl compounds, olefins or dienes, vinyl ethers, and vinyl chloride. Examples of the carboxyl group-containing monomer include (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, etc.; , itaconic anhydride and other acid anhydride group-containing monomers are also included. 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 vinyl sulfonate. 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.

The acrylic polymer constitutes a polymer in order to obtain an acrylic adhesive layer with excellent corrosion resistance when the adherend of the adhesive layer includes metal or metal oxide wiring such as a touch panel. It is preferable that the monomer component does not contain or substantially contains no acidic group-containing monomer, and it is particularly preferable that it does not contain or substantially contains no carboxyl group-containing monomer. Examples of the acidic group-containing monomer 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). It can be said that it does not contain substantially.

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 or more based on 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 (for example, 80 to 100% by weight), still more preferably 90% by weight or more (for example, 90 to 100% by weight).

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

Furthermore, various common solvents may be used during 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 and methylcyclohexane. alicyclic hydrocarbons; 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.

When polymerizing the monomer components, 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.

The thermal polymerization initiator is not particularly limited, but includes, for example, an azo polymerization initiator, a peroxide polymerization initiator (for example, dibenzoyl peroxide, tert-butyl permaleate, etc.), a redox polymerization initiator, etc. can be mentioned. Among these, the azo polymerization initiator disclosed in JP-A No. 2002-69411 is preferred. Examples of the azo polymerization initiator include 2,2'-azobisisobutyronitrile (hereinafter sometimes referred to as "AIBN") and 2,2'-azobis-2-methylbutyronitrile (hereinafter referred to as "AIBN"). (sometimes referred to as "AMBN"), dimethyl 2,2'-azobis(2-methylpropionate), and 4,4'-azobis-4-cyanovaleric acid. Note that the thermal polymerization initiator can be used alone or in combination of two or more types.

When using the azo polymerization initiator during polymerization of the acrylic polymer, the amount of the azo polymerization initiator used is not particularly limited, but for example, 100 parts by weight of all monomer components constituting the acrylic polymer. It is preferably 0.05 part by weight or more, more preferably 0.1 part by weight or more, and preferably 0.5 part by weight or less, more preferably 0.3 part by weight. It is as follows.

The photopolymerization initiator is not particularly limited, but includes, for example, a benzoin ether photopolymerization initiator, an acetophenone photopolymerization initiator, an α-ketol photopolymerization initiator, an aromatic sulfonyl chloride photopolymerization initiator, and a photopolymerization initiator. Examples include active oxime photopolymerization initiators, benzoin photopolymerization initiators, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, thioxanthone photopolymerization initiators, and the like. 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, Examples include anisole methyl ether. Examples of the acetophenone photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenylketone, 4-phenoxydichloroacetophenone, 4-(t-butyl ) dichloroacetophenone, etc. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one, and the like. It will be done. Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime-based 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 photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexylphenyl ketone. 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 photopolymerization initiator include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and the like. . As the titanocene photopolymerization initiator, for example, bis(η ⁵ -2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl ) titanium, etc. In addition, a photoinitiator can be used individually or in combination of 2 or more types.

When the photopolymerization initiator is used during the polymerization of the acrylic polymer, the amount of the photopolymerization initiator used is not particularly limited, but for example, the amount of the photopolymerization initiator is, for example, based on 100 parts by weight of all monomer components constituting the acrylic polymer. The amount 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, and more preferably 1.5 parts by weight or less.

The adhesive layer of the present invention is not particularly limited, but preferably contains a high refractive index organic material. When the adhesive layer of the present invention contains a high refractive index organic material, it is possible to obtain a high refractive index adhesive layer, suppress reflection at the interface with the OLED display panel, and improve the lighting rate of light from the OLED element. ,preferable. Note that the high refractive index organic materials can be used alone or in combination of two or more.

A high refractive index organic material represents an organic material with a high refractive index. By using such a high refractive index organic material in combination with an acrylic polymer, the refractive index, adhesive properties (peel strength, flexibility, etc.) and/or optical properties (total light transmittance, haze value, etc.) can be improved. It is possible to realize a pressure-sensitive adhesive that satisfies both conditions. The organic material used as the high refractive index organic material may be a polymer or a non-polymer. Further, 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. The refractive index of the high refractive index organic material is, for example, greater than 1.50, greater than 1.55, or greater than 1.57, and is preferably 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 higher refractive index organic material, the desired refractive index can be achieved 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, but from the viewpoint of compatibility in the adhesive and the ease of achieving both a high refractive index and flexibility suitable for the adhesive, for example, 3.000 or less, and may be 2.500 or less, 2.000 or less, 1.950 or less, 1.900 or less, or 1.850 or less. Further, as the high refractive index organic material, one that functions as a plasticizer that imparts flexibility to the adhesive layer can also be used.

The refractive index of the high refractive index organic material and the adhesive layer is measured using an Abbe refractometer at a measurement wavelength of 589 nm and a measurement temperature of 25°C. If a manufacturer or the like provides a nominal value of the refractive index at 25° C., that nominal value can be used.

The difference between the refractive index n _b of the high refractive index organic material and the refractive index n _a of the acrylic polymer, that is, n _b - _na (hereinafter also referred to as "Δn _A "), is set to be greater than 0. Ru. 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, 0.40 or less. It may be less than or equal to 0.35.

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 0. In some embodiments, Δn _B 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. Alternatively, it may be 0.25 or more. By selecting the composition of the adhesive layer and the high refractive index organic material so that Δn _B 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 within the adhesive layer, transparency of the adhesive layer, etc., in some embodiments, Δn _B may be, for example, 0.70 or less, 0.60 or less, or 0. It may be .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 (for example, 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. It is suitable that it is less than 5,000, more preferably less than 3,000 (for example, less than 1,000), it may be less than 800, it may be less than 600, it may be less than 500, and it may be less than 400. It may be advantageous that the molecular weight of the high refractive index organic material is not too large from the viewpoint of improving compatibility within the adhesive layer. Further, 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, 2000 or more. A polymer having a molecular weight of about 1,000 to 10,000 (for example, 1,000 or more and less than 5,000) can be used as the high refractive index organic material.
Regarding the molecular weight of high refractive index organic materials, for non-polymers or polymers with a low degree of polymerization (e.g. dimer to pentamer), the molecular weight calculated based on the chemical structure or matrix-assisted laser desorption ionization flight Measured values using time-based mass spectrometry (MALDI-TOF-MS) can be used. When 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. If a nominal value of molecular weight is provided by a manufacturer, etc., that nominal value can be used.

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

The aromatic ring possessed by the organic compound having an aromatic ring (hereinafter also referred to as "aromatic ring-containing compound") used as a high refractive index organic material is similar to the aromatic ring possessed by 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, a glycidyloxy group. Examples include, but are not limited to. In a substituent containing carbon atoms, the number of carbon atoms contained in the substituent is, for example, 1 to 10, advantageously 1 to 6, preferably 1 to 4, more preferably 1 to 3. and can be, for example, 1 or 2. The aromatic ring has no substituent on the ring constituent atoms or has one or more substituents selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom (for example, a bromine atom). 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 containing as monomer units compounds that can be used as aromatic ring-containing monomers; Aromatic ring-containing monomers From the compounds that can be used as a hydrogen atom or an ethylene Compounds whose structure is replaced with a group that does not have a sexually unsaturated group (for example, a hydroxyl group, an amino group, a halogen atom, an alkyl group, an alkoxy group, a hydroxyalkyl group, a hydroxyalkyloxy group, a glycidyloxy group, etc.); etc. However, it is 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 mentioned above, monomers having a dinaphthothiophene structure, monomers having a dibenzothiophene structure, and other aromatic ring-containing monomers; 3-phenoxybenzyl alcohol , dinaphthothiophene and its derivatives (for example, a structure in which one or more substituents selected from a hydroxy group, methanol group, diethanol group, glycidyl group, etc. are bonded to a dinaphthothiophene ring) aromatic ring-containing compounds having no ethylenically unsaturated group, such as compounds such as Further, the aromatic ring-containing compound is an oligomer (preferably an oligomer having a molecular weight of about 5,000 or less, more preferably about 1,000 or less; for example, a low polymer of about 2 to 5 mer) containing such an aromatic ring-containing monomer as a monomer unit. ). The oligomers include, 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 and other monomers. It can be a combination; etc. As the other monomer, one or more monomers having no aromatic ring may be used.

In some embodiments, the high refractive index organic material is an organic compound having two or more aromatic rings in one molecule (hereinafter referred to as "compound containing multiple aromatic rings") because it is easy to obtain a high refractive index effect. ) 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. Further, the compound containing multiple aromatic rings may be a polymer or a non-polymer. Further, the polymer is an oligomer (preferably an oligomer with a molecular weight of about 5000 or less, more preferably about 1000 or less; for example, a low polymer of about 2 to 5 molecules) containing a monomer containing multiple aromatic rings as a monomer unit. obtain. The oligomer may be, for example: a homopolymer of a monomer containing a plurality of aromatic rings; a copolymer of one or more monomers containing a plurality of aromatic rings; a copolymer of one or more monomers containing a plurality of aromatic rings and another monomer; copolymers; etc. 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 bonded via a linking group; Examples include a compound having a chemically bonded structure (without intervening), a compound having a fused aromatic ring structure, a compound having a fluorene structure, a compound having a dinaphthothiophene structure, a compound having a dibenzothiophene structure, and the like. The compound containing multiple aromatic rings can be used alone or in combination of two or more.

Specific examples of the compound having a fluorene structure include the above-mentioned monomer having a fluorene structure and oligomers that are homopolymers or copolymers of such monomers, as well as 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-bisphenylfluorene and its derivatives, such as 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (refractive index: 1.65).

Specific examples of the compound having the dinaphthothiophene structure include the above-mentioned monomer having the dinaphthothiophene structure and oligomers that are homopolymers or copolymers of such monomers, as well as dinaphthothiophene (refractive index: 1. 808); Hydroxyalkyldinaphthothiophenes such as 6-hydroxymethyldinaphthothiophene (refractive index: 1.766); Dihydroxydinaphthothiophenes such as 2,12-dihydroxydinaphthothiophene (refractive index: 1.750); 2 , 12-dihydroxyalkyloxydinaphthothiophene (refractive index: 1.677); diglycidyloxydinaphthothiophene such as 2,12-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); Examples include derivatives thereof.

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

Examples of organic compounds having a heterocycle (hereinafter also referred to as heterocycle-containing organic compounds) that can be selected as high refractive index organic materials include thioepoxy compounds, compounds having a triazine ring, and the like. 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, compounds having a triazine ring are also included in the concept of the aromatic ring-containing compound, and compounds having multiple triazine rings are also included in the concept of the compound containing multiple aromatic rings. be done.

As the high refractive index organic material, a compound having no ethylenically unsaturated group can be preferably employed. Thereby, deterioration of the adhesive composition due to heat or light (decrease in leveling properties due to progress of gelation or increase in viscosity) can be suppressed, and storage stability can be improved. Adopting a high refractive index organic material that does not have ethylenically unsaturated groups means that in an adhesive film having an adhesive layer containing the high refractive index organic material or a laminate containing the adhesive film, ethylenically unsaturated It is also preferable from the viewpoint of suppressing dimensional changes, deformations (warpage, waving, etc.), optical distortion, etc. caused by group reactions.

In embodiments in which oligomers are used as the high refractive index organic material, the oligomers can be obtained by polymerizing the corresponding monomer components 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 in radical polymerization to the monomer component. The polymerization initiator, chain transfer agent, emulsifier, etc. 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 the amounts of the polymerization initiator and chain transfer agent used and the reaction conditions, and the amounts used are adjusted as appropriate depending on the types of these.

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. It will be done. One type of chain transfer agent may be used alone, or two or more types may be used in combination. The amount of the chain transfer agent used can be determined depending on the composition of the monomer components used in oligomer synthesis, the type of chain transfer agent, etc. so as to obtain an oligomer with a desired weight average molecular weight. In some embodiments, the amount of chain transfer agent used is approximately 15 parts by weight or less, and may be 10 parts by weight or less, and may be 5 parts by weight or less, based on 100 parts by weight of the total amount of monomers used to synthesize the oligomer. It may be less than that. 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 in the synthesis of the oligomer is not particularly limited, but may be, for example, 0.01 parts by weight or more, 0.1 parts by weight or more, and 0.01 parts by weight or more. The amount 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 (if multiple types of compounds are used, the total amount thereof) based on 100 parts by weight of the acrylic polymer is not particularly limited as long as it exceeds 0 parts by weight, and is set depending on the purpose. be able to. The amount of the high refractive index organic material used per 100 parts by weight of the acrylic polymer can be, for example, 80 parts by weight or less, achieving a good balance between increasing the refractive index of the adhesive and suppressing deterioration of adhesive properties and optical properties. From this point of view, it is advantageous to use 60 parts by weight or less, and preferably 45 parts by weight or less. From the viewpoint of placing more emphasis on 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, 15 parts by weight or less. The amount may be 10 parts by weight or less. In addition, from the viewpoint of increasing the refractive index of the adhesive, the amount of the high refractive index organic material used per 100 parts by weight of the acrylic polymer can be, for example, 1 part by weight or more, and preferably 3 parts by weight or more. The amount is preferably 5 parts by weight or more, 7 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, and 20 parts by weight or more.

The adhesive layer of the present invention is not particularly limited, but preferably contains an ultraviolet absorber (UVA). When the adhesive layer of the present invention contains an ultraviolet absorber, deterioration of the OLED element due to ultraviolet rays contained in external light can be suppressed, and an OLED display device with excellent weather resistance can be obtained without using a polarizing plate. In addition, deterioration of the high refractive index component due to ultraviolet rays can be suppressed, and a high light absorption rate can be maintained. Note that the ultraviolet absorbers can be used alone or in combination of two or more.

The UV absorbers are not particularly limited, but include, for example, benzotriazole UV absorbers, hydroxyphenyltriazine UV absorbers, benzophenone UV absorbers, salicylic acid ester UV absorbers, cyanoacrylate UV absorbers, and Examples include benzophenone ultraviolet absorbers.

Examples of benzotriazole-based ultraviolet absorbers (benzotriazole-based compounds) include 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 straight chain 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-(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 - Reaction product of butyl-4-hydroxyphenyl) propionate and polyethylene glycol 300 (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: ``Adekastab LA-31'', manufactured by Sumitomo Chemical Co., Ltd.) ) manufactured by ADEKA).

Examples of hydroxyphenyltriazine-based ultraviolet absorbers (hydroxyphenyltriazine-based compounds) include 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)-glycidic acid ester (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 Co., Ltd.), 2-(2 -Hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine (trade name "TINUVIN 479", manufactured by BASF), etc. It will be done. Other examples include a compound represented by the following formula (5) (trade name "TINUVIN 477", manufactured by BASF).

Examples of benzophenone ultraviolet absorbers (benzophenone compounds) and oxybenzophenone ultraviolet absorbers (oxybenzophenone compounds) include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 2-hydroxy-4- Methoxybenzophenone-5-sulfonic acid (anhydride 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 Cipro Kasei Co., Ltd.) , 2,2'-dihydroxy-4,4'-dimethoxybenzophenone and the like.

Examples of salicylic acid ester ultraviolet absorbers (salicylic acid ester compounds) include phenyl 2-acryloyloxybenzoate, phenyl 2-acryloyloxy-3-methylbenzoate, phenyl 2-acryloyloxy-4-methylbenzoate, and phenyl 2-acryloyloxybenzoate. 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) ), etc.

Examples of cyanoacrylate ultraviolet absorbers (cyanoacrylate compounds) include alkyl 2-cyanoacrylates, cycloalkyl 2-cyanoacrylates, alkoxyalkyl 2-cyanoacrylates, alkenyl 2-cyanoacrylates, alkynyl 2-cyanoacrylates, and the like. Can be mentioned.

As the ultraviolet absorber, benzotriazole-based ultraviolet absorbers are selected from the viewpoints of high ultraviolet absorption, excellent optical properties, ease of obtaining an adhesive layer with high transparency, and excellent photostability. At least one type of UV absorber selected from the group consisting of UV absorbers, benzophenone UV absorbers, and hydroxyphenyltriazine UV absorbers is preferred, and benzotriazole UV absorbers and benzophenone UV absorbers are more preferred. Particularly preferred are benzotriazole ultraviolet absorbers in which a group having 6 or more carbon atoms and a phenyl group having a hydroxyl group as a substituent are bonded to the nitrogen atom constituting the benzotriazole ring. Furthermore, from the viewpoint of preventing deterioration in appearance due to precipitation of the ultraviolet absorber, it is preferable to use a liquid ultraviolet absorber or two or more types of ultraviolet absorbers.

Further, in order to obtain higher ultraviolet absorbency, the ultraviolet absorber preferably has an absorbance A determined below of 0.5 or less.
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 adhesive layer of the present invention contains an ultraviolet absorber, the content of the ultraviolet absorber in the adhesive layer of the present invention (particularly the acrylic adhesive layer) is not particularly limited, but the content of the ultraviolet absorber in the adhesive layer of the present invention is not particularly limited. From the viewpoint of suppressing the deterioration of the OLED element due to ultraviolet rays and obtaining an OLED display device with excellent weather resistance without using a polarizing plate, the amount is preferably 0.01 part by weight or more based on 100 parts by weight of the acrylic polymer. , more preferably 0.05 parts by weight or more, still more preferably 0.1 parts by weight or more. Furthermore, the upper limit of the content of the ultraviolet absorber is set at a point that suppresses the yellowing phenomenon of the adhesive caused by the addition of the ultraviolet absorber, and obtains excellent optical properties, high transparency, and excellent appearance characteristics. More preferably, the amount 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, based on 100 parts by weight of the acrylic polymer.

In place of the ultraviolet absorber or in combination with the ultraviolet absorber, a dye compound having a maximum absorption wavelength in the absorption spectrum in a wavelength range of 380 to 430 nm may be contained. The dye compound can also suppress deterioration of OLED elements and high refractive index components caused by ultraviolet light.

The dye compounds may be used alone or in combination of two or more. When only the dye compound is used, the total content of the dye compound is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the base polymer (eg, acrylic polymer), and 0.1 to 20 parts by weight. It is preferably 1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, and more preferably 0.5 to 3 parts by weight. By adjusting the amount of the dye compound added within the above range, it is possible to sufficiently absorb light in a region that does not affect the light emission of the OLED element, and by using the adhesive layer formed from the adhesive composition, the OLED This is preferable because deterioration of the element and deterioration of the high refractive index component can be suppressed.

Although either the ultraviolet absorber or the dye compound can be used, it is preferable to use the ultraviolet absorber and the dye compound together. For example, although the ultraviolet absorber can absorb light with a wavelength of 380 nm, it cannot absorb enough light in the wavelength region (380 nm to 430 nm) shorter than the light emitting region of the OLED element (longer wavelength than 430 nm). The transmitted light may cause deterioration. The dye compound can suppress the transmission of light having a wavelength shorter than 430 nm (380 nm to 430 nm) than the emission region of the OLED element (wavelength longer than 430 nm), and the ultraviolet absorber and the dye compound are used together. Thereby, sufficient visible light transmittance in the light emitting region of the OLED element can be ensured.

In the present invention, by using such a dye compound and an 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 light emitting region (longer wavelength side than 430 nm) can be sufficiently transmitted, and as a result, deterioration of the OLED element due to external light and deterioration of the high refractive index component can be suppressed at the same time. When the ultraviolet absorber and the dye compound are used together, the ultraviolet absorber is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the base polymer (for example, acrylic polymer), It is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight. The amount of the dye compound is preferably about 0.1 to 10 parts by weight, more preferably about 0.1 to 5 parts by weight, based on 100 parts by weight of the base polymer (for example, acrylic polymer). More preferably, it is 0.5 to 3 parts by weight.

The dye compound is not particularly limited as long as it has a maximum absorption wavelength in the absorption spectrum in a wavelength range of 380 to 430 nm. Note that the term "maximum absorption wavelength" means, when there are multiple absorption maxima in the spectral absorption spectrum in the wavelength region of 300 to 460 nm, the absorption maxima wavelength that exhibits the maximum absorbance among them.

It is more preferable that the maximum absorption wavelength of the absorption spectrum of the dye compound exists in a wavelength range of 380 to 420 nm. Further, the dye compound is not particularly limited as long as it has the wavelength characteristics described above, but it is preferably a material that does not have fluorescence or phosphorescence performance (photoluminescence) and does not inhibit the display performance of the OLED element.

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

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

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

The light stabilizer is not particularly limited, but includes, for example, phenolic light stabilizers (phenol compounds), phosphorus light stabilizers (phosphorus compounds), thioether light stabilizers (thioether compounds), and amine light stabilizers. Examples include stabilizers (amine compounds) (particularly hindered amine stabilizers (hindered amine compounds)).

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-tert-butyl-4-ethylphenol, butylated hydroxyanisole, n-octadecyl 3-(4-hydroxy-3,5-di-tert-butylphenyl) propionate, distearyl (4-hydroxy- 3-methyl-5-tert-butyl)benzyl malonate, tocopherol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), tertiary butylphenol), 4,4'-methylenebis(2,6-di-tertiary butylphenol), 4,4'-butylidenebis(6-tertiary butyl-m-cresol), 4,4'-thiobis( 6-tert-butyl-m-cresol), styrenated phenol, N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamide, bis(3,5-di -Tertiary 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-tert-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)isocyanur 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'-oxamidobis[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-tert-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.

Examples of phosphorus-based light stabilizers (phosphorus-based compounds) include trisnonylphenyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris[2-tert-butyl-4-( 3-tertiary butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl] phosphite, tridecyl phosphite, octyldiphenyl phosphite, di(decyl) monophenyl phosphite, di(tridecyl) penta Erythritol diphosphite, distearyl pentaerythritol diphosphite, di(nonylphenyl) pentaerythritol diphosphite, bis(2,4-di-tertiary butylphenyl) pentaerythritol diphosphite, bis(2,6- Di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis(2,4,6-tri-tert-butylphenyl) pentaerythritol diphosphite, tetra(tridecyl)isopropylidene diphenol diphosphite phyto, tetra(tridecyl)-4,4'-n-butylidenebis(2-tert-butyl-5-methylphenol) diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy) -5-tertiary butylphenyl)butane triphosphite, tetrakis(2,4-di-tertiary butylphenyl)biphenylene diphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene- 10-oxide, tris(2-[(2,4,8,10-tetrakis-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl ) amines, etc.

Examples of the thioether light stabilizer (thioether compound) include dialkylthiodipropionate compounds such as dilauryl thiodipropionate, dimyristyl, and distearyl; β of polyols such as tetrakis[methylene(3-dodecylthio)propionate]methane -Alkylmercaptopropionic acid ester compounds and the like.

As the amine light stabilizer (amine compound), for example, a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol (trade name "TINUVIN 622", BASF ), 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 (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) Sebacate and a mixture of 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]butyl malonate (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, 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 and 1,2,2,6,6-pentamethyl-4-piperidinol and 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8, Examples include a mixed ester with 10-tetraoxaspiro[5.5]undecane (trade name "ADEKASTAB LA-63P", manufactured by ADEKA Co., Ltd.). As the amine stabilizer, hindered amine stabilizers are particularly preferred.

When the adhesive layer of the present invention contains a light stabilizer, the content of the light stabilizer in the adhesive layer of the present invention (in particular, the acrylic adhesive layer) is not particularly limited, but the content of the light stabilizer is not particularly limited. In order to facilitate development, the amount is preferably 0.1 part by weight or more, more preferably 0.2 part by weight or more, based on 100 parts by weight of the acrylic polymer. In addition, the upper limit of the content is 5 parts by weight or less based on 100 parts by weight of the acrylic polymer, from the viewpoint of preventing coloring due to the light stabilizer itself, making it easy to obtain high transparency, and improving optical properties. The amount is preferably 3 parts by weight or less, and more preferably 3 parts by weight or less.

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

The crosslinking agent is not particularly limited, but includes, for example, isocyanate crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, urea crosslinking agents, metal alkoxide crosslinking agents, and metal chelate crosslinking agents. Examples include crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, and amine crosslinking agents. Among these, isocyanate-based crosslinking agents and epoxy-based crosslinking agents are preferred, and isocyanate-based crosslinking agents are more preferred.

Examples of the isocyanate crosslinking 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 crosslinking agent include trimethylolpropane/tolylene diisocyanate adduct (product name "Coronate L", manufactured by Nippon Polyurethane Industries, Ltd.), trimethylolpropane/hexamethylene diisocyanate adduct (product name Commercially available products such as "Coronate HL" (manufactured by Nippon Polyurethane Industries, Ltd.) and trimethylolpropane/xylylene diisocyanate adduct (trade name "Takenate D-110N", manufactured by Mitsui Chemicals, Ltd.) are also included.

Examples of the epoxy crosslinking agent (polyfunctional epoxy compound) include N,N,N',N'-tetraglycidyl-m-xylene diamine, 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, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris(2) -hydroxyethyl) isocyanurate, resorcin diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy resins having two or more epoxy groups in the molecule. Examples of the epoxy crosslinking agent include commercially available products such as the trade name "Tetrad C" (manufactured by Mitsubishi Gas Chemical Co., Ltd.).

When a crosslinking agent is used to form the adhesive layer of the present invention, the amount of the crosslinking agent used is not particularly limited, but from the viewpoint of obtaining sufficient adhesion reliability, it is 0.00 parts by weight based on 100 parts by weight of the base polymer. It is preferably at least 0.001 part by weight, more preferably at least 0.01 part by weight. Further, the upper limit of the amount used is preferably 10 parts by weight or less, more preferably 10 parts by weight or less based on 100 parts by weight of the base polymer, from the viewpoint of obtaining appropriate flexibility in the adhesive layer and improving adhesive strength. is 5 parts by weight or less.

The adhesive layer (especially the acrylic adhesive layer) of the present invention contains a silane coupling agent in order to improve the adhesive reliability under humid conditions, especially to improve the adhesive reliability to glass. It's okay. Note that the silane coupling agents can be used alone or in combination of two or more. When the adhesive layer contains a silane coupling agent, the adhesiveness under humid conditions, especially the adhesiveness to glass, can be improved.

The silane coupling agent is not particularly limited, but includes, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-phenyl-aminopropyltrimethoxysilane. Examples include methoxysilane. Furthermore, examples of the silane coupling agent include commercially available products such as the trade name "KBM-403" (manufactured by Shin-Etsu Chemical Co., Ltd.). Among these, γ-glycidoxypropyltrimethoxysilane is preferred as the silane coupling agent.

When the adhesive layer of the present invention contains a silane coupling agent, the content of the silane coupling agent in the adhesive layer of the present invention (especially the acrylic adhesive layer) is not particularly limited, but the content of the silane coupling agent is not particularly limited. It is preferably 0.01 part by weight or more, more preferably 0.02 part by weight or more, based on 100 parts by weight of the base polymer. Further, 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, based on 100 parts by weight of the base polymer.

The adhesive layer of the present invention may further contain a crosslinking accelerator, tackifying resin (rosin derivative, polyterpene resin, petroleum resin, oil-soluble phenol, etc.), anti-aging agent, filler, coloring agent (pigment, etc.), as necessary. It may contain additives such as dyes, etc.), antioxidants, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents, etc., to the extent that they do not impair the effects of the present invention. Note that such additives can be used alone or in combination of two or more.

The method for producing the adhesive layer (particularly the acrylic adhesive layer) of the present invention is not particularly limited, but for example, the adhesive composition is coated on a base material (including a resin layer and a glass layer described below) or a release liner. The pressure-sensitive adhesive composition layer may be coated (coated) on a base material (including a resin layer and a glass layer to be described later) or a release liner, and the resulting pressure-sensitive adhesive composition layer may be dried and cured. An example of this method is to irradiate the resulting adhesive composition layer with active energy rays to cure it. Moreover, if necessary, it may be further dried by heating.

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. Furthermore, the irradiation energy, irradiation time, irradiation method, etc. of the active energy rays are not particularly limited.

The pressure-sensitive adhesive composition can be produced by a known or commonly used method. For example, a solvent-based acrylic pressure-sensitive adhesive composition can be produced by mixing additives (for example, ultraviolet absorbers, etc.) into 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 mixture of acrylic monomers or a partial polymer thereof, if necessary. It can be made.

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

In particular, when forming an adhesive layer using an active energy ray-curable adhesive composition, it is preferable that the active energy ray-curable adhesive composition contains a photopolymerization initiator. In addition, when the active energy ray-curable pressure-sensitive adhesive composition contains an ultraviolet absorber, it is preferable to include at least a photopolymerization initiator having light absorption characteristics in a wide wavelength range. For example, it is preferable to include at least a photopolymerization initiator that has absorption characteristics not only for ultraviolet light but also for visible light. This is because there is a concern that the effect of ultraviolet absorbers may inhibit curing by active energy rays, but if the adhesive composition contains a photoinitiator that has light-absorbing properties over a wide wavelength range, the adhesive composition will have high photocurability. This is because it is easier to obtain.

(adhesive layer)
An adhesive layer is a layer that can bond substances by intervening between adherends, and when an adherend that has been attached with an adhesive layer is peeled off, the adhesive layer has no practical adhesive strength. refers to something that does not have

Various adhesives can be used as the adhesive forming the adhesive layer (hereinafter sometimes referred to as "the adhesive layer of the present invention") constituting the optical element of the present invention, such as isocyanate adhesive. , polyvinyl alcohol adhesive, gelatin adhesive, vinyl latex adhesive, water-based polyester, and the like. These adhesives are usually used as adhesives made of an aqueous solution (aqueous adhesives), and contain a solid content of 0.5 to 60% by weight. Among these, polyvinyl alcohol adhesives are preferred, and acetoacetyl group-containing polyvinyl alcohol adhesives are more preferred.

The water-based adhesive may contain a crosslinking agent. As the crosslinking agent, a compound having at least two functional groups in one molecule that is reactive with components such as polymers constituting the adhesive is usually used, such as alkylene diamines; isocyanates; epoxies; Aldehydes; examples include amino-formaldehydes such as methylol urea and methylol melamine. The amount of the crosslinking agent 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.

Examples of the adhesive include active energy ray curable adhesives such as ultraviolet ray curable adhesives and electron beam curable adhesives in addition to those described above. 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, alicyclic alkyl (meth)acrylates, and polycyclic alkyl (meth)acrylates. ) acrylate; hydroxyl group-containing (meth)acrylate; epoxy group-containing (meth)acrylate such as glycidyl (meth)acrylate; and the like. (Meth)acrylate adhesives include hydroxyethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, (meth)acrylamide, and (meth)acrylate. It may also contain a nitrogen-containing monomer such as acryloylmorpholine. The (meth)acrylate adhesive contains tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane formal acrylate, dioxane glycol diacrylate, EO as a crosslinking component. It may also contain a polyfunctional monomer such as modified diglycerol tetraacrylate. Moreover, 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 coupling agents such as silane coupling agents and 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 or both of the two adherends to be adhered. After bonding, a drying step can be performed to form the adhesive layer of the present invention, which is a coated and dried layer. After the drying step, ultraviolet rays or electron beams can be irradiated if necessary. The thickness of the adhesive layer of the present invention is not particularly limited, and when a water-based adhesive or the like is used, it is preferably about 30 to 5000 nm, more preferably about 100 to 1000 nm, and an ultraviolet curing type When using an adhesive, an electron beam curing adhesive, etc., the thickness is preferably about 0.1 to 100 μm, more preferably about 0.5 to 10 μm.

(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 includes, for example, a plastic film. Materials for the plastic film include, for example, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and cyclic olefin polymers (COP) (for example, product name "Arton" (manufactured by JSR Corporation)). ), product 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 include ketone (PEEK), polyimide (PI), transparent polyimide (CPI), polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, and ethylene-propylene copolymer, which have excellent dimensional stability and do not shrink. Preferred are polyester resins such as hard polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), cyclic olefin polymers (COP), polycarbonate (PC), polyether ether ketone (PEEK), and transparent polyimide (CPI), with polyethylene terephthalate being preferred. (PET) and transparent polyimide (CPI) are more preferred, and transparent polyimide (CPI), which has excellent impact resistance, is particularly preferred. 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 (applied).

The resin layer of the present invention is preferably transparent. The total light transmittance of the resin layer of the present invention in the visible light wavelength region (according to JIS K 7361-1) is not particularly limited, but is preferably 85% or more, more preferably 88% or more. Further, 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 refractive index difference between the adhesive layer and the resin layer (absolute value of "refractive index of the adhesive layer" - "refractive index of the resin layer") is not particularly limited, but it is possible to increase the interfacial antireflection property and From the viewpoint of improving the light absorption rate from the element, it is preferably 2 or less, preferably 1 or less, more preferably 0.5 or less, particularly preferably 0.3 or less.

The thickness of the resin layer of the present invention is not particularly limited, but is preferably, for example, 10 to 80 μm. Note that the resin layer of the present invention may have either a single layer or a multilayer form. Further, 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 undercoat treatment.

The resin layer of the present invention is not particularly limited, but preferably contains an ultraviolet absorber (UVA) and a dye compound whose absorption spectrum has a maximum absorption wavelength in a wavelength range of 380 to 430 nm. When the resin layer of the present invention contains an ultraviolet absorber or the dye compound, 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 with excellent weather resistance without using a polarizing plate. can. Further, it is possible to suppress deterioration of the high refractive index component of the adhesive layer due to ultraviolet rays, and maintain a high light absorption rate. In particular, when the resin layer of the present invention contains an ultraviolet absorber or the dye compound, the content of the ultraviolet absorber or the dye compound in the adhesive layer of the present invention can be reduced, and the content of the ultraviolet absorber or the dye compound in the adhesive layer of the present invention can be reduced. This is preferable because precipitation and bleed-out of the ultraviolet absorber and the dye compound therein can be suppressed.

As the ultraviolet absorber (UVA) and the dye compound contained in the resin layer of the present invention, the same ones as the ultraviolet absorber and the dye compound contained in the adhesive layer of the present invention can be used. In addition, the ultraviolet absorber and the said dye compound can be used individually or in combination of 2 or more types.

When the resin layer of the present invention contains an ultraviolet absorber or the dye compound, the content of each of the ultraviolet absorber or the dye compound in the resin layer of the present invention is not particularly limited, but the content of each of the ultraviolet absorber and the dye compound contained in external light is not limited. From the viewpoint of suppressing the 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 preferable that the amount is 0.01 part by weight or more based on 100 parts by weight of the resin layer. The amount is more preferably 0.05 part by weight or more, and even more preferably 0.1 part by weight or more. In addition, the upper limit of the content of the ultraviolet absorber and the dye compound suppresses the yellowing phenomenon of the adhesive caused by the addition of the ultraviolet absorber, and provides excellent optical properties, high transparency, and excellent appearance. From the viewpoint of obtaining properties, the amount 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, based on 100 parts by weight of the resin layer.

When both the resin layer and the 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; 5 g/m ² ·24 h or more, more preferably 40 g/m ² ·24 h or more, even more preferably 100 g/m ² ·24 h or more, particularly preferably 200 g/m ² ·24 h or more. be. The upper limit of the moisture permeability of the resin layer of the present invention is not particularly limited, but may be 1200 g/m ² ·24 h or less from the viewpoint of suppressing humid expansion. Since the resin layer of the present invention has high moisture permeability, there is a tendency for reliability in lighting performance to improve.

The moisture permeability of the resin layer of the present invention can be measured in accordance with JIS Z0208 at a temperature of 40°C and a relative humidity of 92%, and can be adjusted depending on the type and thickness of the resin constituting the resin layer of the present invention. I can do it.

(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 any suitable layer can be employed depending on the purpose. The glass layer of the present invention is categorized by composition, and includes, for example, soda lime glass, boric acid glass, aluminosilicate glass, quartz glass, and the like. Furthermore, according to classification based on alkali components, alkali-free 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 glass. In addition, the glass layer of the present invention preferably has film-like flexibility and bendability, and since it is possible to suppress double images and project a clear image, The thickness is preferably 60 μm or less. The thickness of the glass layer of the present invention is more preferably 30 μm or more and 55 μm or less, 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 any suitable 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 approximately 1400°C to 1600°C. It can be produced by melting at high temperature, forming it into a thin plate shape, and then cooling it. Examples of methods for forming the glass layer of the present invention include a slot down-draw method, a fusion method, and a float method. 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 make the glass layer thinner or to improve its smoothness.

(Hard coat layer)
As long as 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 the resin include thermosetting resins, thermoplastic resins, ultraviolet curable resins, electron beam curable resins, and two-component mixed resins. Ultraviolet curable resins are preferred. This is because the hard coat layer can be formed with simple operation and high efficiency.

Specific examples of the ultraviolet curable resin include polyester-based, acrylic-based, urethane-based, amide-based, silicone-based, and epoxy-based ultraviolet curable resins. The UV-curable resin includes UV-curable monomers, oligomers, and polymers. Preferred ultraviolet curable resins include resin compositions containing acrylic monomer components or oligomer components having preferably two or more, more preferably three to six, ultraviolet polymerizable functional groups. Typically, a photopolymerization initiator is blended into the ultraviolet curable resin.

The hard coat layer of the present invention can be formed by any suitable method. For example, the hard coat layer of the present invention can be produced by coating a resin composition for forming a hard coat layer on a base material (including the resin layer and glass layer), drying it, and irradiating the dried coating film with ultraviolet rays. It can be formed by hardening.

The thickness of the hard coat layer of the present invention is, for example, 2 μm to 20 μm, preferably 4 μm to 15 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 in accordance with JIS R3257, and can be adjusted depending on the type of resin constituting the hard coat layer, curing conditions, etc.

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

The surface element ratio of carbon element 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 property, 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, for example, 0 atomic % or more.
The surface element ratios of fluorine, carbon, and nitrogen elements on the surface of the hard coat layer of the present invention can be measured by X-ray photoelectron spectroscopy, and are determined by the type of resin constituting the hard coat layer, curing conditions, etc. It can be adjusted by

(Anti-reflection layer)
As the antireflection layer constituting the optical element of the present invention (hereinafter sometimes referred to as "antireflection layer of the present invention"), any suitable configuration can be adopted, for example, (i) the optical film thickness is 120 nm; ~140 nm, a single layer of a low refractive index layer with a refractive index of 1.35 to 1.55, (ii) a laminate having an intermediate refractive index layer, a high refractive index layer, and a low refractive index layer in this order, (iii) Alternating multilayer laminates of high refractive index layers and low refractive index layers.

Examples of materials that can form the low refractive index layer include 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. The curable fluorine-containing resin has, for example, a structural unit derived from a fluorine-containing monomer and a structural unit 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.) , (meth)acrylic acid ester derivatives having a partially or completely fluorinated alkyl group (Viscoat 6FM (manufactured by Osaka Organic Chemical Co., Ltd.), M-2020 (manufactured by Daikin Corporation), etc.), completely or partially Examples include fluorinated vinyl ethers. 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 structural units derived from monomers other than the above-mentioned compounds (for example, olefin monomers, (meth)acrylate monomers, and styrene monomers).

Examples of materials that can form the high refractive index layer include 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 is mentioned. The refractive index of the high refractive index layer is typically about 1.60 to 2.20.

Examples of materials that can form a medium refractive index layer include titanium oxide (TiO ₂ ), a mixture of a material that can form a low refractive index layer, and a material that can form 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 depending on 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), a wet process (e.g., coating), or a combination of 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. Examples of the PVD method include a vacuum evaporation method, a reactive evaporation method, an ion beam assist method, a sputtering method, and an ion plating method. The CVD method includes a plasma CVD method.

As a specific example of the wet process, for example, a coating liquid for forming an antireflection layer may be applied to form a coating film, and the coating film may be cured to form an antireflection layer. As a coating method, for example, 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, or the like can be used. It is preferable to dry the coating film prior to the curing. The drying may be, for example, natural drying, air drying by blowing wind, heat drying, or a combination of these methods. The means for curing the coating film is not particularly limited, but ultraviolet curing is preferred.

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

(Anti-glare layer)
As the anti-glare layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "anti-glare layer of the present invention"), any known material can be employed without restriction, and generally, it is It is formed as a layer in which inorganic or organic particles are dispersed as an anti-glare agent.

The anti-glare layer of the present invention is not particularly limited, but is formed using an anti-glare layer-forming material containing, for example, a resin, particles, and a thixotropy-imparting agent, and the particles and the thixotropy-imparting agent agglomerate. , convex portions are formed on the surface of the anti-glare layer of the present invention. With this configuration, the anti-glare layer has excellent display properties that combine anti-glare properties and prevention of white blur, and even though the anti-glare layer is formed using particle aggregation, It is possible to prevent the occurrence of protrusions on the surface of the anti-glare layer, which would cause defects 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 also possible to use commercially available thermosetting resins, ultraviolet curable resins, and the like.

As the thermosetting resin or the ultraviolet 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 (such as ultraviolet rays), or electron beam, etc. can be used, for example, 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, etc. can give. These may be used alone or in combination of two or more.

For example, a reactive diluent having at least one of an acrylate group and a methacrylate group can also be used in the resin. The reactive diluent can be, for example, the reactive diluent described in JP-A No. 2008-88309, and includes, for example, monofunctional acrylate, monofunctional methacrylate, polyfunctional acrylate, polyfunctional methacrylate, and the like. As the reactive diluent, trifunctional or higher functional acrylates or trifunctional or higher functional methacrylates are preferred. This is because the hardness of the anti-glare layer of the present invention can be made excellent. Examples of the reactive diluent include butanediol glycerol ether diacrylate, isocyanuric acid acrylate, isocyanuric acid methacrylate, and the like. These may be used alone or in combination of two or more.

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

The main functions of the particles for forming the anti-glare layer of the present invention are to impart anti-glare properties by making the surface of the anti-glare layer uneven and to control the haze value of the anti-glare layer. shall be. The haze value of the anti-glare layer can be designed by controlling the difference in refractive index between the particles and the resin. Examples of the particles include inorganic particles and organic particles. The inorganic particles are not particularly limited, and include, for example, 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 include, for example, 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 include resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, polyfluoroethylene 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 diameter (D) of the particles is preferably within the range of 2.5 to 10 μm. By setting the weight average particle diameter of the particles within the above range, for example, it is possible to have better anti-glare properties and prevent white blurring. The weight average particle diameter of the particles is more preferably within the range of 3 to 7 μm. Note that 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) that uses the pore electrical resistance method, an electrolyte solution corresponding to the volume of the particles when the particles pass through the pores is measured. By measuring electrical resistance, the number and volume of the particles are determined, and the weight average particle diameter is calculated.

The shape of the particles is not particularly limited, and may be, for example, approximately spherical in the form of beads, or irregularly shaped such as powder, but is preferably approximately spherical, and more preferably has an aspect ratio. The particles are approximately spherical particles with a ratio of 1.5 or less, and most preferably spherical particles.

The proportion of the particles in the anti-glare 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, based on 100 parts by weight of the resin. It is preferably in the range of 1 to 7 parts by weight. By setting it within the above range, for example, it is possible to have better anti-glare properties and prevent white blurring.

The antiglare layer of the present invention may contain a thixotropy imparting agent. By including the thixotropy 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, oxidized polyolefin, and modified urea.

It is preferable that the organic clay is a clay that has been subjected to an organic treatment in order to improve its affinity with the resin. Examples of the organic clay include layered organic clay. The organic clay may be prepared in-house 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 manufactured by Co-op Chemical Co., Ltd.). ); Esben, Esben C, Esben E, Esben W, Esben P, Esben WX, Esben N-400, Esben NX, Esben NX80, Esben NO12S, Esben NEZ, Esben NO12, Esben NE, Esben NZ, Esben NZ70, Organite, Organite D, Organite T (trade names, all manufactured by Hojun Co., Ltd.); Kunipia F, Kunipia G, Kunipia G4 (trade names, all manufactured by Kunimine Industries Co., Ltd.); Thixogel VZ, Clayton HT and Kraton 40 (trade names, both manufactured by Rockwood Additives).

The oxidized polyolefin may be prepared in-house or a commercially available product may be used. Examples of the commercially available products include Disparon 4200-20 (trade name, manufactured by Kusumoto Kasei Co., Ltd.) and Fluonon 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 prepared in-house or a commercially available product may be used. Examples of the commercially available products include BYK410 (manufactured by Big Chemie).

The thixotropy imparting agent may be used alone or in combination of two or more.

It is preferable that the height of the convex portion from the average roughness line of the anti-glare layer of the present invention is less than 0.4 times the thickness of the anti-glare 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. 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 has convex portions with such heights, thereby making it difficult to cause defects in appearance. Here, the height from the average line can be measured, for example, by the method described in JP-A-2017-138620.

The proportion of the thixotropy imparting agent in the anti-glare 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, based on 100 parts by weight of the resin. .

The thickness (d) of the anti-glare layer of the present invention is not particularly limited, but is preferably within the range of 3 to 12 μm. By setting the thickness (d) of the anti-glare layer within the above range, for example, it is possible to prevent the optical laminate of the present invention from curling, and to avoid the problem of reduced productivity such as poor conveyance. Further, when the thickness (d) is within the above range, the weight average particle diameter (D) of the particles is preferably within the range of 2.5 to 10 μm, as described above. When the thickness (d) of the anti-glare layer of the present invention and the weight average particle diameter (D) of the particles are in the above-mentioned combination, the anti-glare properties can be further improved. The thickness (d) of the anti-glare layer of the present invention is more preferably within the range of 3 to 8 μm.

The relationship between the thickness (d) of the anti-glare 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. By having such a relationship, it is possible to obtain an anti-glare layer that has better anti-glare properties, can prevent white blurring, and has no defects in appearance.

In the anti-glare layer of the present invention, the particles and the thixotropy imparting agent aggregate to form convex portions on the surface of the anti-glare layer of the present invention. In the agglomerated portion forming the convex portion, a plurality of the particles are present in a state of being gathered in the surface direction of the anti-glare layer of the present invention. Thereby, the convex portion has a gentle shape. By having the convex portions having such a shape, the anti-glare layer of the present invention can maintain anti-glare properties and prevent white blurring, and can also be made less likely to cause defects in appearance. can.

The surface shape of the anti-glare layer of the present invention can be arbitrarily designed by controlling the aggregation state of particles contained in the anti-glare layer forming material. The agglomeration state of the particles can be controlled by, for example, the material of the particles (for example, the chemical modification state of the particle surface, the affinity for solvents and resins, etc.), the type and combination of resins (binder) or solvents, and the like. Here, the agglomeration state of the particles can be controlled by the thixotropy imparting agent contained in the anti-glare layer forming material of the present invention. As a result, the agglomeration state of the particles can be made as described above, and the convex portion can have a gentle shape.

In the anti-glare layer of the present invention, it is preferable that the number of appearance defects having a maximum diameter of 200 μm or more is one or less per 1 m ² of the anti-glare layer. More preferably, there is no appearance defect.

In the uneven shape of the surface of the anti-glare layer 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, particularly preferably 1.6 to 4.0. Here, the average inclination angle θa is a value defined by the following formula (1). The average inclination angle θa is a value measured by the method described in JP-A-2017-138620, for example.
Average inclination angle θa=tan-1Δa (1)

In the above formula (1), Δa is the distance between the peaks and valleys of adjacent peaks in the standard length L of the roughness curve specified in JIS B 0601 (1994 edition), as shown in the formula (2) below. This is the value obtained by dividing the total (h1+h2+h3...+hn) of the difference (height h) from the lowest point by the reference length L. The roughness curve is a curve obtained by removing surface waviness components longer than a predetermined wavelength from a cross-sectional curve using a phase difference compensating high-pass filter. Further, the cross-sectional curve is a contour that appears at a cut end when the target surface is cut by a plane perpendicular to the target surface.
Δa=(h1+h2+h3...+hn)/L (2)

When θa is within the above range, the anti-glare property is more excellent and white blur can be prevented.

In forming the anti-glare layer of the present invention, it is preferable that the prepared anti-glare layer forming material (coating liquid) exhibits thixotropy, and has a Ti value defined below of 1.3 to 3.5. It is preferably in the range of 1.3 to 2.8, and 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 Rheostress 6000 manufactured by HAAKE, and β2 is the viscosity measured at a shear rate of 200 (1/s) using Rheostress 6000 manufactured by HAAKE. This is the viscosity measured under the following conditions.

When the Ti value is less than 1.3, defects in appearance are likely to occur, and properties regarding anti-glare properties and white blurring deteriorate. Furthermore, when the Ti value exceeds 3.5, the particles are less likely to aggregate and become more likely to be in a dispersed state.

The method for producing the anti-glare layer of the present invention is not particularly limited and may be produced by any method. For example, the anti-glare layer forming material (coated The anti-glare layer can be manufactured by preparing an anti-glare layer liquid), applying the anti-glare layer forming material (coating liquid) to form a coating film, and curing the coating film to form an anti-glare layer. It is also possible to use a transfer method using a mold, a method of imparting an uneven shape by an appropriate method such as sandblasting, embossing roll, etc.

The solvent is not particularly limited, and various solvents can be used, and one type may be used alone or two or more types may be used in combination. There are optimal solvent types and solvent ratios depending on the composition of the resin, the types and contents of the particles and the thixotropy-imparting agent, and the like. Examples of the solvent 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, xylene, etc.

By appropriately selecting the solvent, the thixotropic property of the antiglare layer forming material (coating liquid) can be expressed favorably by the thixotropy imparting agent. For example, when using organoclay, toluene and xylene can be preferably used alone or in combination; for example, when using an oxidized polyolefin, methyl ethyl ketone, ethyl acetate, propylene glycol monomethyl ether can preferably be used alone. They can be used or used in combination. For example, when using modified urea, butyl acetate and methyl isobutyl ketone can be suitably used alone or in combination.

Various leveling agents can be added to the anti-glare 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 uneven coating (uniform coating surface). The leveling agent is selected as appropriate depending on the case where antifouling properties are required on the surface of the anti-glare layer of the present invention, or when an anti-reflection layer or a layer containing an interlayer filler is formed on the anti-glare layer. be able to. For example, by including the thixotropy imparting agent, the coating liquid can exhibit thixotropy, so that coating unevenness is less likely to occur. For this reason, it has the advantage that, for example, the options for the leveling agent can be expanded.

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

If necessary, pigments, fillers, dispersants, plasticizers, ultraviolet absorbers, surfactants, antifouling agents, antioxidants, etc. may be added to the anti-glare layer forming material within a range that does not impair performance. may be done. These additives may be used alone or in combination of two or more.

For the anti-glare layer forming material, a conventionally known photopolymerization initiator as described in JP-A No. 2008-88309, for example, can be used.

As a method for applying the anti-glare layer forming material, for example, a coating method such as 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, etc. may be used. I can do it.

The anti-glare 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 wind, heat drying, or a combination of these methods.

The means for curing the coating film of the anti-glare layer forming material is not particularly limited, but ultraviolet curing is preferred. The irradiation amount of the energy ray source is preferably 50 to 500 mJ/cm ² as a cumulative exposure amount at an ultraviolet wavelength of 365 nm. If the irradiation amount is 50 mJ/cm ² or more, curing will be more sufficient, and the anti-glare layer formed will also have more sufficient hardness. Moreover, if it is 500 mJ/cm ² or less, coloring of the formed anti-glare layer can be prevented.

The antiglare layer of the present invention can be formed in the manner described above. Note that the antiglare layer may be formed by a manufacturing method other than the above-mentioned method. The hardness of the anti-glare layer of the present invention is influenced by the thickness of the layer in terms of pencil hardness, but preferably has a hardness of 2H or more.

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

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

(middle class)
The intermediate layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "intermediate layer of the present invention") is between the resin layer and the hard coat layer, antireflection layer, or antiglare layer. It is formed in Formation of this intermediate layer improves the 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 a compatible layer) of the present invention is formed is not particularly limited, but for example, in the formation of the hard coat layer, antireflection layer, or antiglare layer, the hard coat layer is formed. It is formed in the process of applying, permeating, and drying a coating liquid for use with a resin layer, a coating liquid for forming an antireflection layer, or a coating liquid for forming an anti-glare layer. In the drying step, for example, a coating liquid for forming a hard coat layer, a coating liquid for forming an antireflection layer, or a coating liquid for forming an anti-glare layer penetrates into the resin layer, and the resin derived from the resin layer and the hard coat are mixed. layer, an antireflection layer, or a resin derived from an antiglare layer. The resin contained in the intermediate layer is not particularly limited, and for example, the resin contained in the resin layer and the resin contained in the hard coat layer, antireflection layer, or antiglare layer are simply mixed (compatible). But that's fine. Further, the resin contained in the intermediate layer may be chemically treated by heating, light irradiation, etc., at least one of the resin contained in the resin layer and the resin contained in the hard coat layer, antireflection layer, or antiglare layer. It may be changing.

The thickness ratio R of the intermediate layer defined by the following formula (1) is not particularly limited, but is, for example, 0.10 to 0.80, for example, 0.15 or more, 0.20 or more, 0.25 or more, 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 to 0.50, 0.15 to 0.45, 0.15 to 0.40, 0.15 to 0.30, or 0.20 to 0.30. The intermediate layer can be confirmed and its thickness can be measured, for example, by observing a cross section of the optical element with a transmission electron microscope (TEM).
R=[DC/(DC+DB)] (1)
In the formula (1), DB is the thickness [μm] of the hard coat layer, antireflection layer, or antiglare layer, and DC is the thickness [μm] of the intermediate layer.

When an intermediate layer is formed between the resin layer and the hard coat layer, antireflection layer, or antiglare layer, shear failure between the resin layer and the hardcoat 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 fracture strength can be determined by the SAICAS method, and is determined by 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 shock absorbing layer (hereinafter sometimes referred to as "the shock absorbing layer of the present invention") constituting the optical element of the present invention may be composed of any suitable resin layer that can achieve a desired shock absorption rate. The resin layer may be composed of a resin film or an adhesive. The impact absorption 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, and still more preferably 40 μm to 120 μm. If the thickness of the impact absorption layer of the present invention is within this range, an optical laminate having excellent impact resistance can be realized.

The storage modulus G' at 25° C. of the shock absorbing layer of the present invention is preferably 0.1 GPa or less, more preferably 0.01 MPa to 0.1 GPa. If the storage modulus of the impact-absorbing layer of the present invention is within this range, it has the advantage of absorbing impact and preventing cracking of the optical laminate. Furthermore, a synergistic effect with the above thickness effect may 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, it may be coated with a conductive coating liquid containing a conductive polymer. This is an antistatic layer formed. Specific coating methods include roll coating, bar coating, and gravure coating.

Examples of the conductive polymer include a conductive polymer in which a π-conjugated conductive polymer is doped with a polyanion. Examples of the π-conjugated conductive polymer include chain conductive polymers such as polythiophene, polypyrrole, polyaniline, and polyacetylene. Examples of the polyanion include polystyrene sulfonic acid, polyisoprene sulfonic acid, polyvinyl sulfonic acid, polyallylsulfonic acid, polyethyl acrylate sulfonic acid, and polymethacrylic carboxylic acid.

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

(Manufacturing method of optical laminate)
The method for producing the optical laminate of the present invention is not particularly limited, and includes the adhesive layer, adhesive layer, resin layer, glass layer, hard coat layer, antireflection layer, antiglare layer, which constitutes the optical element of the present invention, It can be manufactured by sequentially laminating an intermediate layer (compatible layer), a shock absorption layer, etc. on the viewing side of the OLED display panel of the present invention, and the laminate constituting the optical laminate of the present invention can be manufactured by laminating the intermediate layer (compatible layer), shock absorption layer, etc. It can be manufactured by preparing it in advance and laminating it on the viewing side of the OLED display panel of the present invention. When a laminate constituting the optical laminate of the present invention is prepared in advance, it may be a laminate that constitutes the entire optical laminate of the present invention, or a laminate that constitutes a part of the optical laminate of the present invention. may be divided 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 a surface protection film until use.

(Release liner)
The adhesive layer of the present invention may have a release liner provided on the surface (adhesive surface) of the adhesive layer until use. The release liner is used as a protective material for the adhesive layer and is peeled off when it is applied to an adherend. Note that the release liner does not constitute the optical element of the present invention and does not necessarily need to be provided.

As the release liner, a conventional release paper or the like can be used, and examples thereof include, but are not limited to, a base material having a release treatment layer, a low-adhesive base material made of a fluoropolymer, and a low-adhesive base material made of a non-polar polymer. Examples include. Examples of the base material having the release treatment layer include plastic films and papers whose surface has been treated with a release agent such as silicone, long-chain alkyl, fluorine, and molybdenum sulfide. Examples of the fluoropolymer in the low-adhesive base material made of the fluoropolymer include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and chlorofluoroethylene. Examples include fluoroethylene-vinylidene fluoride copolymer. Furthermore, examples of the nonpolar polymer include olefin resins (eg, polyethylene, polypropylene, etc.). Note that the release liner can be formed by a known or commonly used method. Furthermore, 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 laminate of the present invention may be protected by a surface protection film. The surface protection film may be applied by the consumer. Note that the surface protection film does not constitute the optical element of the present invention and does not necessarily need to be provided.

As the surface protection film, any known or commonly used surface protection film can be used, and is not particularly limited, but for example, a plastic film having an adhesive layer on the 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 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)acrylate copolymer adhesives, Examples include adhesive layers formed from one or more types of known or commonly used adhesives such as styrene-isoprene block copolymer adhesives and styrene-butadiene block copolymer adhesives. The adhesive layer may contain various additives (for example, antistatic agents, slip agents, etc.). Note that the plastic film and the adhesive layer may each have a single layer structure or a multilayer (multilayer) structure. Moreover, the thickness of the surface protection film is not particularly limited and can be selected as appropriate.

(OLED display device of the present invention)
An embodiment of an OLED display device in which an optical laminate 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 in which the optical laminate of the present invention is laminated.

As shown in FIG. 2, in the OLED display device 200, layers constituting an optical laminate 20 are laminated on the viewing side (upper side in FIG. 2) of the OLED display panel 100. The OLED display panel 100 is not particularly limited, but may have the same configuration as the OLED display panel 100 shown in FIG. 1, for example.

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

In 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, and 27 is an adhesive layer. The resin layer 28 is a hard coat layer without the antireflection layer 29, and at least one of the adhesive layers 21, 24, and 26 is an adhesive layer having light scattering properties. FIG. 3 shows an OLED display device 300 according to this embodiment. In FIG. 3, 31 to 38 are layers constituting the optical laminate 30, 31 is an adhesive layer, 32 is a resin layer, 33 is a hard coat layer, 34 is an adhesive layer, 35 is a glass layer, and 36 is a An adhesive layer having light scattering properties, 37 a resin layer, and 38 a hard coat layer. Since the adhesive layer 36 has light scattering properties, color shift and interference unevenness caused by the OLED display panel 100 are suppressed, and the OLED display device 300 has excellent visibility.
Note that in the OLED display device 300 shown in FIG. 3, an antireflection layer may be present on the visible side of the hard coat layer 38.

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, 21 is an adhesive layer, 22 is a resin layer, 23 is a hard coat layer, and 24 is an adhesive layer. 25 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, there is no antireflection layer 29, and at least one of the adhesive layers 21, 24, and 26 is The pressure-sensitive adhesive layer has light-scattering properties, and the distance d (μm) between the pressure-sensitive adhesive layer having light-scattering properties and the color filter is 700 μm or less. By setting the distance d between the adhesive layer having light scattering properties and the color filter to be 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 blurring of an OLED display device due to lamination of light scattering layers, it is preferable that the distance between the adhesive layer having light scattering properties and the color filter is 600 μm or less. The thickness is preferably 500 μm or less, more preferably 500 μm or less, and most preferably the adhesive layer having light scattering properties is in direct contact with the color filter. OLED display devices 400A and 400B according to this embodiment are shown in FIGS. 4(a) and 4(b), respectively. In FIG. 4(a), 41A to 48A are layers constituting the optical laminate 40A, 41A is an adhesive layer, 42A is a resin layer, 43A is a hard coat layer, 44A is an adhesive layer, and 45A is a glass layer. , 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 visible side (upper side in FIG. 4A) of the OLED display panel 400B, and the distance d (μm) between the adhesive layer 46A having light scattering properties and the color filter 15A is is 700 μm or less. In FIG. 4(b), 41B to 48B are layers constituting the optical laminate 40B, 41B is an adhesive layer having light scattering properties, 42B is a resin layer, 43B is a hard coat layer, and 44B is an adhesive layer. , 45B is a glass layer, 46B is an adhesive layer, 47B is a resin layer, and 48B is a hard coat layer. 15B is a color filter arranged on the viewing side (upper side in FIG. 4(b)) of the OLED display panel 400B. Since the adhesive layer 41B having light scattering properties and the color filter 15B are in direct contact with each other, that is, the distance between the adhesive layer 41B having light scattering properties and the color filter 15B is 0 μm, the OLED display device Color shift and interference unevenness caused by 400B can be suppressed most efficiently.
Note that in the OLED display devices 400A and 400B shown in FIGS. 4A and 4B, an antireflection layer may be present on the visible side of the hard coat layers 48A and 48B.

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 anti-glare layer, and no anti-reflection layer 29 is present. FIG. 5 shows an OLED display device 500 according to this embodiment. In FIG. 5, 51 to 58 are layers constituting the optical laminate 50, 51 is an adhesive layer, 52 is a resin layer, 53 is a hard coat layer, 54 is an adhesive layer, 55 is a glass layer, and 56 is a The adhesive layer, 57 is a resin layer, and 58 is an anti-glare layer. Since the optical laminate 50 has the anti-glare layer 58, color shift and interference unevenness caused by the OLED display panel 100 are suppressed, and the OLED display device 500 has excellent visibility.
Note that in the OLED display device 500 shown in FIG. 5, an antireflection layer may be present on the viewing side of the antiglare layer 58.

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. 6 shows an OLED display device 600 according to this embodiment. In FIG. 6, 61 to 69 are layers constituting the optical laminate 60, 61 is an adhesive layer, 62 is a resin layer, 63 is a hard coat layer, 64 is an adhesive layer, 65 is a glass layer, and 66 is a 67 is a resin layer, 68 is a hard coat layer, and 69 is an antireflection layer. Since the optical laminate 60 has the antireflection layer 69, interference unevenness caused by the OLED display panel 100 is suppressed, and the OLED display device 600 has excellent visibility.
In the OLED display device 600 shown in FIG. 6, 68 may be an anti-glare layer. In this embodiment, the anti-reflection function is further improved by laminating the anti-glare layer 68 and the anti-reflection layer 69.

As another preferred embodiment of the present invention, in FIG. 2, 21 is an adhesive layer, 22 is a resin layer, 23 is not present, 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 no antireflection layer 29 is 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 is not present. OLED display devices 700A and 700B according to this embodiment are shown in FIGS. 7(a) and 7(b), respectively. In FIG. 7(a), 71A, 72A, 74A to 78A are layers constituting the optical laminate 70A, 71A is an adhesive layer, 72A is a resin layer, 74A is an adhesive layer, 75A is a glass layer, and 76A is a resin layer. 77A is a resin layer, and 78A is a hard coat layer. Further, in FIG. 7(b), 71B to 78B are layers constituting the optical laminate 70B, 71B is an adhesive layer, 72B is a resin layer, 73B is a hard coat layer, 74B is an adhesive layer, and 75B is an adhesive layer. The glass layer, 76B is an adhesive layer, 77B is a resin layer, and 78B is a hard coat layer. In FIG. 7(a), the resin layer 72A and the glass layer 75A are bonded together by the adhesive layer 74A, or in FIG. 7(b), the glass layer 75B and the resin layer 77B are bonded by the adhesive layer 74A. By being bonded by the layer 76B, excellent impact resistance is imparted to each of the optical laminates 70A and 70B even if the optical laminates 70A and 70B do not have polarizing plates. Further, although the glass layer has excellent impact resistance, it is a material that is easily broken and has low flexibility. By bonding the glass layer and the resin layer with an adhesive layer, flexibility and bendability are improved, and the OLED display devices 700A and 700B can be used for flexible devices and foldable devices.
Note that in the OLED display devices 700A and 700B shown in FIGS. 7A and 7B, an antireflection layer may be present on the visible side of the hard coat layers 78A and 78B.

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 and 26 are absent, and 27 is a resin layer. The layer 28 is a hard coat layer, the antireflection layer 29 is not present, and one or both of the resin layers 22 and 27 is a transparent polyimide layer. FIG. 8 shows an OLED display device 800 according to this embodiment. In FIG. 8, 81 to 84, 87, and 88 are layers constituting the optical laminate 80, 81 is an adhesive layer, 82 is a transparent polyimide layer, 83 is a hard coat layer, 84 is an adhesive layer, and 87 is an adhesive layer. The resin layer 88 is a hard coat layer. In FIG. 8, the optical laminate 80 has a transparent polyimide layer 82 and a hard coat layer 83, thereby providing excellent impact resistance even when the optical laminate 80 does not have a polarizing plate. Furthermore, in this embodiment, the optical laminate 80 does not have a glass layer. Although the glass layer is a material that exhibits high hardness and excellent impact resistance, it has poor handling properties 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 high hardness equivalent to that of a glass layer, and it also has excellent handling properties, so it can be applied to large displays used in PCs, tablets, etc.

In the embodiment shown in FIG. 8, it is preferable that an intermediate layer (compatible phase) be formed between the transparent polyimide layer 82 and the hard coat layer 83 (not shown). By forming an intermediate layer (compatible phase) between the transparent polyimide layer 82 and the hard coat layer 83, the adhesion between the transparent polyimide layer 82 and the hard coat layer 83 is improved. In that case, the shear fracture strength between the transparent polyimide layer 82 and the hard coat layer 83 is preferably 20 MPa or more.

In FIG. 9(a), 900 is an adhesive film, 91 is an adhesive layer, 92 is a resin layer, and 93 is a release liner. In FIG. 9(b), 901 is an OLED display device, 91 is an adhesive layer, 92 is a resin layer, and 100 is an OLED display panel.

In FIG. 9A, the adhesive film 900 has a configuration in which an adhesive layer 91 and a resin layer 92 are laminated in this order on the upper side of a release liner 93. Although the resin layer 92 is not an essential structure, it is preferable to exist from the viewpoint of improving impact resistance. A release liner 93 is temporarily attached to the surface of the adhesive layer 91. The release liner 93 is not particularly limited, but for example, a sheet-like base material having a release layer formed of a release agent on one side so that one side becomes a release surface can be preferably used. Before bonding to the OLED display panel 100 as an adherend, the release liner 93 is peeled off from the surface of the adhesive layer 91, and the exposed surface of the adhesive layer 91 is bonded to the surface of the OLED display panel 100. , the adhesive film 900 is temporarily attached to the OLED display panel 100. The thickness of the release liner 93 is not particularly limited, but is, for example, 3 to 200 μm, preferably 10 to 100 μm.

FIG. 9B shows a form in which the adhesive film 900 obtained by the above operation is temporarily attached to the OLED display panel 100. In FIG. 9B, the adhesive layer 91 of the adhesive film 900 is in contact with the visible side (upper side) of the OLED display panel 100.

When the adhesive film 900 has the resin layer 92, the adhesive film 900 without the release liner 93 can also be used. By winding the adhesive film 900, the adhesive surface of the adhesive layer 91 that does not face the resin layer 92 comes into contact with the surface of the resin layer 92 where the adhesive layer 91 does not exist, and is protected (roll form). There may be. In the adhesive film 900 having a roll form, the surface of the adhesive layer 91 is exposed before being attached to the OLED display panel 100, and the exposed surface of the adhesive layer 91 is attached to the surface of the OLED display panel 100. , the adhesive film 900 is temporarily attached to the OLED display panel 100.

By performing an adhesive force increasing treatment on the adhesive layer 91 of the adhesive film 900 temporarily attached to the adherend, the adhesive force of the adhesive layer 91 increases, and the adhesive force between the adherend and the resin layer 92 increases. It is fixed via layer 91.

In this specification, "adhesion" refers to a state in which two laminated layers are firmly adhered to each other and it is impossible or difficult to separate them at the interface. "Temporary adhesion" is a state in which the adhesive strength between two laminated layers is small and they can be easily peeled off at the interface between them.

Furthermore, from the viewpoint of daylight rate reliability, that is, from the viewpoint of suppressing separation and precipitation of additives such as the above-mentioned high refractive index organic material, it is preferable that the adhesive layer 91 has a low moisture permeability, and the resin layer 92 has a high moisture permeability. It is preferable that it is moisture permeable.

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 absorption layer 23 Hard coat layer or anti-glare layer 24 Adhesive layer or adhesive layer 25 Resin layer, glass layer or shock absorption layer 26 Adhesive layer or adhesive layer 27 Resin layer, glass layer or shock absorption layer 28 Hard coat layer or anti-glare layer 29 Antireflection layer 300 OLED display device 30 Optical laminate 31 Adhesive layer 32 Resin layer 33 Hard coat layer 34 Adhesive layer 35 Glass layer 36 Adhesive layer having light scattering properties 37 Resin layer 38 Hard coat layer 400A OLED display device 40A Optical laminate 41A Adhesive layer 42A Resin layer 43A Hard coat layer 44A Adhesive layer 45A Glass layer 46A Adhesive layer with light scattering properties 47A Resin layer 48A Hard coat layer 15A Color filter 400B OLED display device 40B Optical laminate 41B Adhesive layer with light scattering properties 42B Resin layer 43B Hard coat layer 44B Adhesive layer 45B Glass layer 46B Adhesive layer 47B Resin layer 48B Hard coat layer 15B Color filter 500 OLED display device 50 Optical laminate 51 Adhesive layer 52 Resin layer 53 Hard coat layer 54 Adhesive layer 55 Glass layer 56 Adhesive layer 57 Resin layer 58 Anti-glare layer 600 OLED display device 60 Optical laminate 61 Adhesive layer 62 Resin layer 63 Hard coat layer 64 Adhesive layer 65 Glass layer 66 Adhesive layer 67 Resin layer 68 Hard coat layer 69 Antireflection layer 700A OLED display device 70A Optical laminate 71A Adhesive layer 72A Resin layer 74A Adhesive layer 75A Glass layer 76A Adhesive layer 77A Resin layer 78A Hard coat layer 700B OLED display device 70B Optical laminate 71B Adhesive layer 72B Resin layer 73B Hard coat layer 74B Adhesive Layer 75B Glass layer 76B Adhesive layer 77B Resin layer 78B Hard coat layer 800 OLED display device 80 Optical laminate 81 Adhesive layer 82 Transparent polyimide layer 83 Hard coat layer 84 Adhesive layer 87 Resin layer 88 Hard coat layer 900 Adhesive film 901 OLED display device 91 Adhesive layer 92 Resin layer 93 Release liner

Claims (1)

An adhesive film used in an OLED display device in which only an optical element with a degree of polarization of 95% or less is laminated on the viewing side of an OLED element,
The optical element has at least one layer containing an ultraviolet absorber as a layer constituting the optical element,
An adhesive film for an OLED display device having a 380 nm transmittance of 20% or less.

Images