Composition for forming an adhesive layer

Abstract

This technology improves the display quality of display devices and extends the life of light-emitting elements. [Solution] The adhesive sheet comprises an adhesive and a dye, the dye comprising a first coloring material having a maximum absorption wavelength in the range of 470 nm to 530 nm and a half-width of the absorption spectrum of 15 nm to 45 nm, a second coloring material having a maximum absorption wavelength in the range of 560 nm to 620 nm and a half-width of the absorption spectrum of 15 nm to 55 nm, and a third coloring material having the lowest transmittance in the wavelength range of 400 to 780 nm in the range of 650 nm to 780 nm. In an adhesive sheet having a colored adhesive layer with a thickness of 25 μm and an ultraviolet absorbing layer with an ultraviolet shielding rate of 85% or more, a hue value a * and b * are in the range of -5 to +5, respectively.

Description

Technical Field

[0001] The present invention relates to a composition for forming an adhesive layer.

Background Art

[0002] Unlike liquid crystal display devices and the like, self-emitting display devices such as organic light-emitting display devices are excellent in miniaturization, and further have excellent characteristics such as low power consumption, high brightness, and high response speed, and are expected as the next-generation display devices. Metal electrodes and wirings are formed in the area of the display surface of the self-emitting display device. Since these metallic electrodes and wirings reflect light incident from the outside (i.e., external light), it is easy to cause a decrease in display quality such as a decrease in contrast.

[0003] In order to suppress the above-described decrease in display quality, for example, a configuration in which a polarizing plate and a retardation plate are arranged on the surface of a self-emitting display device has been proposed. However, in the configuration using a polarizing plate and a retardation plate, when the light emitted from the display device passes through the polarizing plate and the retardation plate and is emitted to the outside, most of the light is lost, and it is easy to cause a decrease in element life.

[0004] In addition, a high color purity is required for the display device. Color purity indicates the range of colors that can be displayed by the display device and is also called the color reproduction range. Therefore, high color purity means a wide color reproduction range and good color reproducibility. As means for improving color reproducibility, a method of separating colors by using a color filter for a light source that emits white light, or a method of correcting a light source that emits monochromatic light of the three primary colors RGB with a color filter to narrow the half-value width is known. However, when improving the color reproducibility of a display device using a color filter, it is necessary to increase the thickness of the color filter or increase the concentration of the coloring material, and there are problems such as deterioration of pixel shape and viewing angle characteristics, which reduce the display quality. In addition, for a display device that emits monochromatic light of the three primary colors RGB, a process for forming a color filter is required, which results in an increase in cost.

[0005] As a display device different from the configuration in which the above-described polarizing plate and retardation plate are arranged or the configuration using a color filter, for example, Patent Document 1 discloses a display device having an optical filter containing a coloring material that selectively absorbs a predetermined wavelength band. Since this optical filter selectively absorbs light in a wavelength band that particularly reduces color purity among the light emitted from the display device, the loss of light necessary for displaying the three primary colors emitted from the organic light-emitting element is suppressed, and the visibility of the display image is improved. However, in the disclosed technology, there are problems that the effect of suppressing the degradation of display quality due to reflection of external light is insufficient and that the reflected light has a colored tint. Patent Document 2 discloses an adhesive film containing a specific color correction dye and an ultraviolet stabilizer as an optical filter that absorbs light of a specific wavelength. However, these disclosed optical filters have insufficient reliability in light resistance and heat resistance and have been difficult to put into practical use.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] The optical filter disclosed in the above-mentioned Patent Document 1 contains a coloring material having an absorption peak wavelength in a first wavelength band of 480 nm to 510 nm, a coloring material having an absorption peak wavelength in a second wavelength band of 580 nm to 610 nm, and further coloring materials having absorption peak wavelengths in 650 nm to 710 nm and 360 nm to 420 nm, thereby suppressing a decrease in luminance and improving color purity. When an optical filter containing coloring materials that absorb light of these specific wavelengths is used in a display device, reflection characteristics such as the reflectance of external light and the reflected hue due to external light reflection change. However, Patent Document 1 discloses a method for adjusting the transmission characteristics according to the light-emitting light source of the display device, but does not disclose a method for adjusting the external light reflection luminance and the reflected hue, making it difficult to use as a reflection-reducing member. Thus, in conventional optical filters and display devices such as organic light-emitting display devices, improvement in display quality and extension of the lifespan of light-emitting elements have been demanded.

[0008] In view of the above circumstances, the present invention provides a composition for forming an adhesive layer capable of improving display quality and extending the lifespan of light-emitting elements.

Means for Solving the Problems

[0009] In order to solve the above problems, the present invention is a composition for forming an adhesive layer containing an adhesive and a pigment. The pigment contains a first coloring material having a maximum absorption wavelength in the range of 470 nm or more and 530 nm or less and a half-value width of the absorption spectrum of 15 nm or more and 45 nm or less, a second coloring material having a maximum absorption wavelength in the range of 560 nm or more and 620 nm or less and a half-value width of the absorption spectrum of 15 nm or more and 55 nm or less, and a third coloring material having the wavelength with the lowest transmittance in the range of 400 to 780 nm in the range of 650 nm or more and 780 nm or less. In an adhesive sheet having a colored adhesive layer with a thickness of 25 μm formed by the composition for forming an adhesive layer and an ultraviolet absorption layer provided on one surface of the colored adhesive layer and having an ultraviolet shielding rate of 85% or more in accordance with JIS L 1925, the hue values a * and b * are each in the range of -5 or more and +5 or less.

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[0019] Here, λ is a variable representing the wavelength, and t is a variable representing the ratio of X, Y, and Z with respect to X, Y, and Z. n , Y n , Z n a calculated by formulas (1) to (3) * , b *is CIE1976L * a * b * It is calculated according to the calculation method in the color space (CIELAB color space). In formulas (1) and (2), X n , Y n , Z n are the tristimulus values at the white point of the D65 light source. In formula (4), R E (λ) represents a function of the reflectance [%] on a perfectly diffusing reflecting surface (100% for each wavelength), R2(λ) represents a function of the surface reflectance [%] on the outermost surface of the adhesive sheet on the side opposite to the side in contact with the colored adhesive layer with respect to the ultraviolet absorption layer, and T(λ) represents a function of the transmittance [%] of the adhesive sheet. In formulas (6) to (9), P D65 (λ) is the D65 light source spectrum, and overline x(λ), overline y(λ), overline z(λ) are the metameric functions in the CIE1931 2° field of view. The definite integrals in formulas (6) to (9) may be obtained by appropriate numerical integration. For example, the wavelength interval in the case of performing numerical integration may be 1 nm interval. In formula (5), R(λ) represents the reflectance of the optical film with respect to the incident light from the side opposite to the side in contact with the colored adhesive layer with respect to the ultraviolet absorption layer, taking into account the internal reflection in the adhesive sheet. X, Y, and Z represented by formulas (6) to (8) represent the tristimulus values at the white point of the D65 light source.

Advantages of the Invention

[0020] According to the present invention, it is possible to provide a composition for forming an adhesive layer that can improve the display quality in external light reflection and improve the lifespan of the light-emitting element of the display device.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0022] Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common descriptions are omitted.

[0023] (First Embodiment) As shown in FIG. 1, the adhesive sheet 100A according to the first embodiment of the present invention includes at least a colored adhesive layer 11 and an ultraviolet absorbing adhesive layer (ultraviolet absorbing layer) 13.

[0024] The colored adhesive layer 11 is formed by a composition for forming an adhesive layer. The composition for forming an adhesive layer contains an adhesive, a pigment, and an additive. The adhesive contained in the colored adhesive layer 11 is, for example, a resin that exhibits adhesiveness, such as a silicone-based adhesive, an acrylic-based adhesive, a urethane-based adhesive, etc., but is not particularly limited.

[0025] The colored adhesive layer 11 is composed of one or more layers containing the first to third color materials as pigments. That is, the pigment contains the first to third color materials. FIGS. 1 and 2 show the colored adhesive layer 11 composed of one layer. The maximum absorption wavelength of the first color material is in the range of 470 nm or more and 530 nm or less. The half-value width of the absorption spectrum of the first color material is 15 nm or more and 45 nm or less. In this specification, the absorption maximum wavelength means the wavelength that gives the maximum value among the maximum absorption rates in the absorption spectrum. The maximum absorption wavelength of the second color material is in the range of 560 nm or more and 620 nm or less. The half-value width of the absorption spectrum of the second color material is 15 nm or more and 55 nm or less. For the third color material, the maximum absorption wavelength is not particularly limited, and it means that the wavelength with the lowest transmittance in the wavelength range of 400 nm or more and 780 nm or less is in the range of 650 nm or more and 780 nm or less. In the adhesive sheet 100A, peaks of the maximum absorption wavelengths of the above-mentioned first to third color materials appear in the absorption spectrum of the entire colored adhesive layer 11. Hereinafter, when the first color material, the second color material, and the third color material are collectively referred to, they may simply be referred to as color materials.

[0026] The first to third color materials contained in the colored adhesive layer 11 preferably include one or more compounds selected from the group consisting of compounds having any of a porphyrin structure, a merocyanine structure, a phthalocyanine structure, an azo structure, a cyanine structure, a squarylium structure, a coumarin structure, a polyene structure, a quinone structure, a tetraziporphyrin structure, a pyromethene structure, and an indigo structure, and metal complexes thereof. In particular, it is preferable to use compounds having a porphyrin structure, a pyromethene structure, a phthalocyanine structure, or a squarylium structure in the molecule.

[0027] The colored adhesive layer 11 preferably contains at least one of a radical scavenger, a peroxide decomposer, and a singlet oxygen quencher as additives. By including these additives, fading of the coloring material contained in the colored adhesive layer 11 due to light, heat, etc. can be suppressed, and durability can be improved.

[0028] The radical scavenger includes constituent materials that capture radicals when the dye undergoes oxidative degradation and have the function of suppressing auto-oxidation, thereby suppressing dye degradation (fading). When a hindered amine-based light stabilizer with a molecular weight of 2000 or more is used as the radical scavenger, a high fading suppression effect can be obtained. When the molecular weight of the radical scavenger is low, it is likely to volatilize, so there are few molecules remaining in the colored layer, and it is difficult to obtain a sufficient fading suppression effect. Materials preferably used as the radical scavenger include, for example, BASF's Chimassorb (registered trademark) 2020FDL, Chimassorb (registered trademark) 944FDL, Tinuvin (registered trademark) 622, ADEKA's LA-63P, etc.

[0029] The singlet oxygen quencher has the function of inactivating highly reactive singlet oxygen, which has the property of easily oxidatively degrading (fading) the dye, and suppressing the oxidative degradation (fading) of the dye. Examples of the singlet oxygen quencher include transition metal complexes, dyes, amines, phenols, and sulfides. Particularly preferably used materials include transition metal complexes of dialkyl phosphate, dialkyldithiocarbamate, or benzenedithiol, and nickel, copper, or cobalt is preferably used as the central metal. For example, NKX1199, NKX113, NKX114 manufactured by Hayashibara Biochemical Laboratories, Inc., Photosensitive Dye Research Institute, D1781, B1350, B4360, T3204 manufactured by Tokyo Chemical Industry Co., Ltd., etc. can be mentioned.

[0030] The peroxide decomposer has the function of decomposing the peroxide generated when the dye undergoes oxidative degradation, stopping the auto-oxidation cycle, and suppressing dye degradation (fading). The peroxide decomposer includes constituent materials capable of inactivating hydroperoxide, and is preferably, for example, a phosphorus-based antioxidant or a sulfur-based antioxidant.

[0031] Examples of phosphorus-based antioxidants include 2,2'-methylenebis(4,6-di-t-butyl-1-phenyloxy)(2-ethylhexyloxy)phosphorus, 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, and 6-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-t-butyldibenz[d,f][1,3,2]dioxaphosphepine.

[0032] Examples of sulfur-based antioxidants include 2,2-bis({[3-(dodecylthio)propionyl]oxy}methyl)-1,3-propanediyl-bis[3-(dodecylthio)propionate], 2-mercaptobenzimidazole, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, pentaerythrityl-tetrakis(3-laurylthiopropionate), 2-mercaptobenzothiazole.

[0033] The ultraviolet-absorbing adhesive layer 13 is provided on the surface (one side) 11a of the colored adhesive layer 11. The ultraviolet shielding rate of the ultraviolet-absorbing adhesive layer 13 is preferably 85% or more. In this specification, the ultraviolet shielding rate means the ultraviolet shielding rate measured in accordance with JIS L 1925, and represents the value [%] obtained by subtracting the average transmittance (unit; [%]) in the wavelength range from 290 nm to 400 nm from 100%.

[0034] The ultraviolet-absorbing adhesive layer 13 contains an ultraviolet absorber having an ultraviolet shielding rate of 85% or more and an adhesive. Examples of the ultraviolet absorber include benzophenone-based, benzotriazole-based, triazine-based, oxalic acid anilide-based, and cyanoacrylate-based compounds. The adhesive contained in the ultraviolet-absorbing adhesive layer 13 is, for example, a resin that exhibits adhesiveness, such as a silicone-based adhesive, an acrylic-based adhesive, or a urethane-based adhesive, and may be of the same type as the adhesive contained in the colored adhesive layer 11, and is not particularly limited.

[0035] The pressure-sensitive adhesive sheet 100A can be manufactured, for example, by forming one of a colored pressure-sensitive adhesive layer 11 and an ultraviolet-absorbing pressure-sensitive adhesive layer 13 on a base film formed of resin or the like, forming the other thereon, and then peeling off the base film. The colored pressure-sensitive adhesive layer 11 and the ultraviolet-absorbing pressure-sensitive adhesive layer 13 can be formed, for example, by applying a coating liquid containing the constituent materials of each layer and drying it. Note that the base film may be used as a coating layer 15 described later without being peeled off from one of the colored pressure-sensitive adhesive layer 11 and the ultraviolet-absorbing pressure-sensitive adhesive layer 13.

[0036] In the pressure-sensitive adhesive sheet 100A, when light emitted from a D65 light source is irradiated from the surface 13a side (the side opposite to the side where the colored pressure-sensitive adhesive layer is in contact with the ultraviolet-absorbing layer, that is, the upper side of the ultraviolet-absorbing pressure-sensitive adhesive layer) of the ultraviolet-absorbing pressure-sensitive adhesive layer 13 in the thickness direction with respect to the pressure-sensitive adhesive sheet 100A and is completely diffusely reflected on the surface 11b side of the lowermost layer of the pressure-sensitive adhesive sheet, the reflectance R(λ) is measured from the light source irradiation side, and the chromaticness index (value) a * and b * of each are within the range of -5 or more and +5 or less. The above-described hue is one of the uniform color spaces defined by the International Commission on Illumination (CIE) (CIE1976L * a * b * color space, or also referred to as the CIE LAB color space), and is represented by three-dimensional orthogonal coordinates with three values of the lightness index L represented by the following formula (10) in addition to the above formulas (1) and (2). * is represented by three-dimensional orthogonal coordinates with the three values as axes.

[0037]

Equation

[0038] Here, Y is calculated from the above formulas (4), (5), (7), and (9) using the tristimulus values of the reflected light at the reflectance R(λ) of the D65 light source, and Y n is the tristimulus value at the white point of the D65 light source.

[0039] Chromaticness index a as an index of the external light reflection hue of the pressure-sensitive adhesive sheet of the present invention * and b * The calculation method thereof will be described with reference to FIG. 2.

[0040] As shown in FIG. 2, when the D65 light source is irradiated from the surface 13a on the side opposite to the side in contact with the colored pressure-sensitive adhesive layer 11 with respect to the ultraviolet absorption pressure-sensitive adhesive layer 13 of the pressure-sensitive adhesive sheet 100A in the thickness direction, the reflected light of the pressure-sensitive adhesive sheet 100A can be considered separately into a surface reflection component and an internal reflection component. The surface reflection component is defined by the surface reflectance R2(λ) [%] at the surface 13a, and the internal reflection component is the reflectance R E (λ) [%] of a perfect diffusing reflection surface that is 100% regardless of the wavelength, the transmittance T(λ) [%] in the pressure-sensitive adhesive sheet 100A, and the surface reflectance R2(λ) [%] at the surface 13a, and is defined by R1(λ) [%] calculated by Equation (4). When the reflectance of the pressure-sensitive adhesive sheet 100A on the surface 13a side on the D65 light source irradiation side is R(λ) [%], R(λ) is calculated from the above-described Equation (5). Since R(λ) is a function of the wavelength λ similar to R1(λ) and R2(λ), the three stimulus values X, Y, and Z can be obtained by obtaining the definite integral with respect to λ in Equations (6) to (9). Here, the definite integral may be obtained by appropriate numerical integration. For example, the wavelength interval in the case of performing numerical integration may be an equal interval such as 1 nm interval.

[0041] As described above, X, Y, and Z in Equations (1) and (2) are the three stimulus values of the reflected light at the reflectance R(λ) of the D65 light source on the surface 13a side of the pressure-sensitive adhesive sheet 100A, and X n , Y n , Z n represent the three stimulus values at the white point of the D65 light source. From this, the chromaticness indices a * and b * of the pressure-sensitive adhesive sheet 100A can be calculated. From the viewpoint of enhancing the display quality of the external light reflection, the chromaticness index (value) a * and the value b *It is preferable that each of them is in the range of -5 or more and +5 or less. The internal reflectance that occurs on the inner surface such as the display section and the electrode wiring section of a self-luminous display device such as an organic light-emitting display device generally has different values at each wavelength from 380 nm to 780 nm. As a result of intensive studies in the present invention, R E is defined as the reflectance of a perfect diffusive reflecting surface with 100% at all wavelengths, and the chromaticness index (value) a of the reflected hue of external light of the adhesive sheet 100A * and the value b * When each of them is in the range of -5 or more and +5 or less, R E Even when (λ) is replaced with the internal reflectance of the light-emitting layer 35 of an actual self-luminous display device, the chromaticness index a which is an index of the external light reflected hue * and b * are in the range of -5 or more and +5 or less, and it has been found that excellent display quality is obtained.

[0042] The adhesive sheet 100A is configured such that a separate and desired optical device or optical material can be installed on the surface 11b on the side opposite to the surface 11a of the colored adhesive layer 11 and the surface 13a of the ultraviolet-absorbing adhesive layer 13. As shown in FIG. 1, in a state where no desired optical device or optical material is installed, in order to prevent dirt from adhering to the sticky surfaces 11b and 13a, the coating layers 15-1 and 15-2 are detachably installed on the surfaces 11b and 13a. That is, the adhesive sheet 110A includes a colored adhesive layer 11, an ultraviolet-absorbing adhesive layer 13, and coating layers 15-1 and 15-2. Hereinafter, when explaining the common content of the coating layers 15-1 and 15-2, these coating layers are collectively referred to as the coating layer 15.

[0043] For the coating layer 15, for example, any type of release material or separator is used. Examples of the separator include a resin film and paper.

[0044] The coating layer 15-1 of the adhesive sheet 110A can be peeled off from the colored adhesive layer 11, and the light-emitting layer 35 can be installed without gaps on the surface 11b of the colored adhesive layer 11. Further, the coating layer 15-2 of the adhesive sheet 110A can be peeled off from the ultraviolet-absorbing adhesive layer 13, and the protective layer 200 can be installed without gaps on the surface 13a of the ultraviolet-absorbing adhesive layer 13. By providing the light-emitting layer 35 and the protective layer 200 on the adhesive sheet 100A in this way, the display device 120A shown in FIG. 3 is configured.

[0045] As shown in FIG. 3, the display device 120A according to the present invention includes a light-emitting layer 35 and an adhesive sheet 100A. The adhesive sheet 100A is disposed in front of the traveling direction E1 of the emitted light emitted from the light-emitting layer 35 through the color filter 33.

[0046] The light-emitting layer 35 includes a substrate 31, light-emitting elements 32-1, 32-2, 32-3, and a color filter 33. The substrate 31 is formed of, for example, a silicon (Si) substrate. The light-emitting elements 32-1, 32-2, 32-3 are embedded in the substrate 31 and emit, for example, white light. The emission surface of each of the light-emitting elements 32-1, 32-2, 32-3 is exposed on the surface 31a of the substrate 31. As the light-emitting elements 32-1, 32-2, 32-3, for example, organic EL elements are used.

[0047] The color filter 33 is partitioned into a red transmission region 33-R, a green transmission region 33-G, and a blue transmission region 33-B in the thickness direction within a unit region for each pixel and in the direction along the surface 11b. From the red transmission region 33-R, red light among the white light emitted from the light-emitting element 32-1 is emitted from the surface 33a of the color filter 33 along the traveling direction E1. From the green transmission region 33-G, green light among the white light emitted from the light-emitting element 32-1 is emitted from the surface 33a of the color filter 33 along the traveling direction E1. From the blue transmission region 33-B, blue light among the white light emitted from the light-emitting element 32-1 is emitted from the surface 33a of the color filter 33 along the traveling direction E1.

[0048] The protective layer 200 is provided to protect the light-emitting layer 35 and the adhesive sheet 100A from impacts from the outside (upward in FIG. 1) and the like. The protective layer 200 has optical properties that do not significantly affect at least the visible light transmission spectrum of the light emitted in the traveling direction E1 from the surface 13a of the ultraviolet-absorbing adhesive layer 13 of the adhesive sheet 100A. "Do not significantly affect the transmission spectrum" means that when the hue expressed on the surface 200a of the protective layer 200 is measured from the direction opposite to the traveling direction E1, the chromaticness indices a * and the value b * each fall within the range of -5 or more and +5 or less. The protective layer 200 is formed of, for example, glass, a resin film, or a resin plate that is transparent to visible light. In this specification, visible light means light having an emission wavelength band from 380 nm to 780 nm.

[0049] (Modification of the First Embodiment) In the adhesive sheets 100A and 110A of the first embodiment, the colored adhesive layer 11 is composed of only one layer containing the first to third color materials, but may be composed of two or more layers. As shown in FIG. 4, the colored adhesive layer 11 may have a three-layer structure in which a colored adhesive layer 12-1 containing only the first color material, a colored adhesive layer 12-2 containing only the second color material, and a colored adhesive layer 12-3 containing only the third color material are laminated in the thickness direction. It is only necessary to contain the first to third color materials as a whole for the three-layer structure, and the lamination order of the colored adhesive layers 12-1, 12-2, and 12-3 in the three-layer structure is not particularly limited. Although not shown, the colored adhesive layer 11 may include a first colored adhesive layer containing either the first color material or the second color material and the third color material, and a second colored adhesive layer containing the other of the first color material and the second color material and the third color material.

[0050] As described above, the pressure-sensitive adhesive sheet 100A' of the modified example of the first embodiment having two or more colored pressure-sensitive adhesive layers exhibits the same operational effects as the pressure-sensitive adhesive sheet 100A. Further, as shown in FIG. 4, similar to the pressure-sensitive adhesive sheet 100A, a light-emitting layer 35 and a protective layer 200 may be combined with the pressure-sensitive adhesive sheet 100A' to form a display device 120A'.

[0051] The composition for forming a pressure-sensitive adhesive layer according to the present invention can form the pressure-sensitive adhesive sheets 100A and 100A' of the first embodiment and its modified example, and contains a pressure-sensitive adhesive, a pigment, and an additive. The pigment contained in the composition for forming a pressure-sensitive adhesive layer for forming the pressure-sensitive adhesive sheet 100A contains a first colorant, a second colorant, and a third colorant, and the pigment contained in the composition for forming a pressure-sensitive adhesive layer for forming the pressure-sensitive adhesive sheet 100A' contains either one of the first colorant and the second colorant and the third colorant.

[0052] (Second Embodiment) Next, the pressure-sensitive adhesive sheet and the like of the second embodiment according to the present invention will be described. For each of the embodiments after the second embodiment, the differences from the foregoing upper embodiments will be described, and the contents and descriptions common to the upper embodiments will be generally omitted. Further, in the description of the configurations of the embodiments after the second embodiment, the same reference numerals will be assigned to the configurations common to the upper embodiments, and the descriptions thereof will be omitted.

[0053] As shown in FIG. 5, the pressure-sensitive adhesive sheet 100B according to the second embodiment of the present invention includes a colored pressure-sensitive adhesive layer 11 and an ultraviolet-absorbing transparent substrate (ultraviolet-absorbing layer) 17. Hereinafter, the ultraviolet-absorbing transparent substrate may be simply described as a "transparent substrate". The ultraviolet-absorbing transparent substrate 17 is provided on the surface 11a of the colored pressure-sensitive adhesive layer 11. The ultraviolet-absorbing transparent substrate 17 has an ultraviolet absorber and functions as an ultraviolet-shielding layer, has an ultraviolet-shielding rate of 85% or more, and is formed of a material excellent in visible light transmittance. As the main forming materials other than the ultraviolet absorber of the ultraviolet-absorbing transparent substrate 17, polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyacrylates such as polymethyl methacrylate, polyamides such as nylon 6 and nylon 66, polyimide, polyarylate, polycarbonate, triacetyl cellulose, polyacrylate, polyvinyl alcohol, polyvinyl chloride, cycloolefin copolymer, norbornene-containing resin, transparent resins such as polyethersulfone and polysulfone, and inorganic glass can be used. Among these, a film made of polyethylene terephthalate (PET), a film made of triacetyl cellulose (TAC), a film made of polymethyl methacrylate (PMMA), and a film made of polyester can be preferably used. The thickness of the ultraviolet-absorbing transparent substrate 17 is not particularly limited, but is preferably 10 to 100 μm.

[0054] The ultraviolet absorptivity of the transparent substrate 17 can be imparted, for example, by blending an ultraviolet absorber into the resin material for forming the transparent substrate 17. The ultraviolet absorber is not particularly limited, but compounds of benzophenone type, benzotriazole type, triazine type, oxalic acid anilide type, and cyanoacrylate type can be used.

[0055] The adhesive sheet 100B is configured such that a separate and desired optical device or optical material can be installed on the surface 11b of the colored adhesive layer 11. That is, the adhesive sheet 110B includes the colored adhesive layer 11, the ultraviolet-absorbing transparent base material 17, and the coating layer 15-1. Although not shown, by peeling the coating layer 15-1 of the adhesive sheet 110B from the colored adhesive layer 11, the light-emitting layer 35 illustrated in the first embodiment can be installed on the surface 11b of the colored adhesive layer 11 without any gaps.

[0056] The adhesive sheets 100B and 110B of the second embodiment, and the display device including the adhesive sheets 100B and 110B described above have the same operational effects as the adhesive sheets 100A and 110A, and the display device 120A of the first embodiment. Further, according to the adhesive sheets 100B and 110B of the second embodiment, the ultraviolet-absorbing transparent base material 17 can be made to function as a protective layer or a cover in a state where it is disposed on the outermost surface in the overall structure, and the thinning of the device or the like to which the adhesive sheets 100B and 110B are applied and the simplification of the assembly process can be achieved.

[0057] Note that the same modifications as those of the adhesive sheets 100A and 110A of the first embodiment can be applied to the adhesive sheets 100B and 110B of the second embodiment.

[0058] (Third Embodiment) Next, the adhesive sheet and the like according to the third embodiment of the present invention will be described.

[0059] As shown in FIG. 6, the adhesive sheet 100C according to the third embodiment of the present invention includes a colored adhesive layer 11, an ultraviolet-absorbing transparent base material (ultraviolet-absorbing layer) 17, and an oxygen barrier layer 20. The oxygen barrier layer 20 is provided in an upper layer than 11-a which is on the ultraviolet-absorbing transparent base material 17 side of the colored adhesive layer 11. The adhesive sheet 100C in FIG. 6 shows a case where the oxygen barrier layer 20 is provided on the side closer to the ultraviolet-absorbing transparent base material 17 than the colored adhesive layer 11 in the thickness direction.

[0060] The oxygen permeability of the oxygen barrier layer 20 is 10 cc / m 2 ·day·atm or less, and 5 cc / m 2·It is more preferable that it is below ·day·atm. As the main constituent material of the oxygen barrier layer 20, it is preferable to contain polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), vinylidene chloride, siloxane resin, etc., and it is possible to use Maxeeve (registered trademark) manufactured by Mitsubishi Gas Chemical Company, Eval, Poval manufactured by Kuraray Co., Ltd., Saran latex, Saran resin, etc. manufactured by Asahi Kasei Corporation. Further, the thickness of the oxygen barrier layer 20 is not particularly limited, and it may be a thickness that can obtain a desired oxygen barrier property.

[0061] Also, inorganic particles (particles made of an inorganic compound) may be dispersed in the oxygen barrier layer 20. With the inorganic particles, the oxygen permeability can be made lower, and the oxidative degradation (fading) of the colored layer 21 can be more suppressed. The size and content of the inorganic particles are not particularly limited, and may be appropriately set according to the thickness of the oxygen barrier layer 25, etc. The size (maximum length) of the inorganic particles dispersed in the oxygen barrier layer 20 is preferably less than the thickness of the oxygen barrier layer 20, and the smaller the size, the more advantageous. Note that the size of the inorganic particles dispersed in the oxygen barrier layer 20 may be uniform or non-uniform. Specific examples of the inorganic particles dispersed in the oxygen barrier layer 20 include silica particles, alumina particles, silver particles, copper particles, titanium particles, zirconia particles, tin particles, etc.

[0062] The adhesive sheet 100C is configured such that a separate and desired optical device or optical material can be installed on the surface 11b of the colored adhesive layer 11. That is, as shown in FIG. 6, the adhesive sheet 110C includes a colored adhesive layer 11, an ultraviolet-absorbing transparent base material 17, an oxygen barrier layer 20, and a coating layer 15-1. Although not shown, the coating layer 15-1 of the adhesive sheet 110C can be peeled off from the colored adhesive layer 11, and the light-emitting layer 35 can be installed on the surface 11b of the colored adhesive layer 11 without any gaps.

[0063] The adhesive sheets 100C, 110C of the third embodiment described above, and the display device including the adhesive sheets 100C, 110C have the same effects as the adhesive sheets 100A, 110A, and the display device 120A of the first embodiment.

[0064] Further, in the pressure-sensitive adhesive sheets 100C and 110C of the third embodiment, an oxygen barrier layer 20 with an oxygen permeability of 10 cc / m 2 ·day·atm or less is provided on the surface 17a of the ultraviolet-absorbing transparent base material 17. The deterioration of the light resistance of the dye can be said to be oxidative deterioration due to the intervention of oxygen. According to the pressure-sensitive adhesive sheets 100C and 110C, oxygen contained in the outside air does not reach the colored pressure-sensitive adhesive layer 11 without permeating through the oxygen barrier layer 20 in the thickness direction. Therefore, deterioration of the first to third color materials contained in the colored pressure-sensitive adhesive layer 12 due to oxygen in the outside air can be suppressed. Accordingly, the light absorption performance of the colored pressure-sensitive adhesive layer 11 can be maintained for a long time. That is, according to the pressure-sensitive adhesive sheets 100C and 110C, deterioration of the colored pressure-sensitive adhesive layer 11 caused by a chemical reaction with oxygen can be suppressed.

[0065] Note that the same modifications as those of the pressure-sensitive adhesive sheets 100A and 110A of the first embodiment can be applied to the pressure-sensitive adhesive sheets 100C and 110C of the third embodiment.

[0066] (Fourth Embodiment) Next, the pressure-sensitive adhesive sheet and the like according to the fourth embodiment of the present invention will be described.

[0067] As shown in Fig. 7, the pressure-sensitive adhesive sheet 100D according to the fourth embodiment of the present invention includes a colored pressure-sensitive adhesive layer 11, an ultraviolet-absorbing transparent substrate (ultraviolet-absorbing layer) 17, and a hard coat layer 22. The hard coat layer 22 is provided on the surface 17a of the ultraviolet-absorbing transparent substrate 17 on the side opposite to the colored pressure-sensitive adhesive layer 11 in the thickness direction. The hard coat layer 22 is a hard layer formed of a resin or the like, and is provided to enhance the scratch resistance of the optical sheet 130D described below. The hardness of the hard coat layer 22 preferably has a pencil hardness of H or higher under a 500 g load on the surface. The pencil hardness is measured based on JIS-K5600-5-4:1999. Examples of the constituent material of the hard coat layer 22 include urethane (meth)acrylate, polyester (meth)acrylate, epoxy (meth)acrylate, and the like. In addition, it is convenient to form the hard coat layer 22 with an energy ray-curable compound such as an ultraviolet-curable resin. In this case, a coating liquid containing at least an energy ray-curable compound, a polymerization initiator, and a solvent is applied to the ultraviolet-absorbing transparent substrate 17, and the corresponding energy rays are irradiated and cured to form the hard coat layer 22. Further, the composition for forming the hard coat layer 22 contains metal oxide fine particles for the purpose of adjusting the refractive index and imparting hardness, any one of silicon oxide, a fluorine-containing silane compound, fluoroalkylsilazane, fluoroalkylsilane, a fluorine-containing silicon-based compound, and a perfluoropolyether group-containing silane coupling agent for imparting water repellency and / or oil repellency and imparting antifouling properties, and a conductive material such as a quaternary ammonium cation or conductive metal fine particles for the purpose of imparting antistatic properties. Examples of the metal oxide fine particles include zirconium oxide, titanium oxide, niobium oxide, antimony trioxide, antimony pentoxide, tin oxide, indium oxide, indium tin oxide, zinc oxide, and the like. In addition, a leveling agent, an antifoaming agent, a photosensitizer, etc. may be contained as necessary.

[0068] The optical sheet 130D according to the present invention includes an adhesive sheet 100D and a low refractive index layer (optical functional layer, antireflection layer) 24. The low refractive index layer 24 is provided on the surface 22a of the ultraviolet absorbing transparent substrate 17 of the hard coat layer 22, which is on the opposite side in the thickness direction. That is, in the optical sheet 130D, the low refractive index layer 24 is disposed on the side where external light is incident with respect to the ultraviolet absorbing transparent substrate 17. The low refractive index layer 24 has a lower refractive index than the hard coat layer 22 and is provided to reduce the reflection of external light incident on the optical sheet 130D (i.e., reflection to the observer side). The low refractive index layer 24 can be formed by curing a coating liquid containing at least an active energy ray curable resin. The active energy ray curable resin described for the hard coat layer 22 can be used. Fine particles such as LiF, MgF, 3NaF·AlF, AlF, Na3AlF6 and silica fine particles may be blended for refractive index adjustment. Using silica fine particles having voids inside the particles, such as porous silica fine particles and hollow silica fine particles, is effective for reducing the refractive index of the low refractive index layer. Also, a photoinitiator, a solvent, and other additives may be appropriately blended. The refractive index of the low refractive index layer 24 is preferably 1.20 to 1.55. Also, the film thickness of the low refractive index layer 24 is not particularly limited, but is preferably 40 nm to 1 μm.

[0069] The low refractive index layer 24 may contain any one of a silicon oxide, a fluorine-containing silane compound, a fluoroalkylsilazane, a fluoroalkylsilane, a fluorine-containing silicon-based compound, and a perfluoropolyether group-containing silane coupling agent. These materials can enhance the antifouling property by imparting water repellency and / or oil repellency to the low refractive index layer 24.

[0070] The adhesive sheet 100D and the optical sheet 130D are configured such that a separate and desired optical device or optical material can be installed on the surface 11b of the colored adhesive layer 11. That is, the adhesive sheet 110D includes a colored adhesive layer 11, an ultraviolet-absorbing transparent base material 17, a hard coat layer 22, a low refractive index layer 24, and a coating layer 15-1. Although not shown, the coating layer 15-1 of the adhesive sheet 110D can be peeled off from the colored adhesive layer 11, and the light-emitting layer 35 can be installed on the surface 11b of the colored adhesive layer 11 without gaps.

[0071] The adhesive sheets 100D and 110D, the optical sheet 130D, and the display device including the adhesive sheets 100D and 110D according to the fourth embodiment described above have the same effects as the adhesive sheets 100A and 110A and the display device 120A of the first embodiment.

[0072] Further, according to the adhesive sheets 100D and 110D of the fourth embodiment, since the hard coat layer 22 is provided on the surface 17a of the ultraviolet-absorbing transparent base material 17, the scratch resistance against external impacts and the like can be enhanced.

[0073] The optical sheet 130D according to the present invention includes an adhesive sheet 100D and an optical functional layer that is disposed on the incident side of external light with respect to the ultraviolet-absorbing transparent base material 17 of the adhesive sheet 100D and reduces the surface reflection of external light. The aforementioned optical functional layer is the low refractive index layer 24 that functions as an antireflection layer. According to the optical sheet 130D, since the strong surface reflection of external light is suppressed, the visibility of a display device or the like to which the optical sheet 130D is applied and its display content can be enhanced.

[0074] Note that the same modifications as those of the adhesive sheets 100A and 110A of the first embodiment can also be applied to the adhesive sheets 100D and 110D and the optical sheet 130D of the fourth embodiment.

[0075] (Fifth Embodiment) Next, the adhesive sheet and the like according to the fifth embodiment of the present invention will be described.

[0076] As shown in FIG. 8, the pressure-sensitive adhesive sheet 100E according to the fifth embodiment of the present invention includes a colored pressure-sensitive adhesive layer 11 and an ultraviolet-absorbing transparent substrate (ultraviolet-absorbing layer) 17.

[0077] The optical sheet 130E according to the present invention includes the pressure-sensitive adhesive sheet 100E and an antiglare layer (optical functional layer) 26. The antiglare layer 26 is provided on the surface 17a on the side opposite to the colored pressure-sensitive adhesive layer 11 of the ultraviolet-absorbing transparent substrate 17 in the thickness direction. The antiglare layer 26 is provided to reduce the reflected light (i.e., regular reflection or specular reflection) from the position of the display screen when applied to a display device or the like and prevent glare. The antiglare layer 26 can be formed by curing a coating liquid containing an active energy ray-curable resin and, if necessary, organic fine particles and / or inorganic fine particles. As the active energy ray-curable resin, those described for the hard coat layer 22 can be used. The film thickness of the antiglare layer 26 is not particularly limited, but is preferably 1 to 10 μm. The organic fine particles form fine irregularities on the surface of the antiglare layer 26 and impart a function of diffusing external light. For example, resin particles made of a light-transmitting resin material such as acrylic resin, polystyrene resin, styrene-(meth)acrylate copolymer, polyethylene resin, epoxy resin, silicone resin, polyvinylidene fluoride, or a polyfluoroethylene-based resin can be used. In order to adjust the refractive index and the dispersibility of the resin particles, two or more types of resin particles having different materials (refractive indices) may be mixed and used. The inorganic fine particles adjust the sedimentation and aggregation of the organic fine particles in the antiglare layer 26, and silica fine particles, metal oxide fine particles, various mineral fine particles, etc. can be used as the inorganic fine particles.

[0078] The antiglare layer 26 may contain any one of silicon oxide, a fluorine-containing silane compound, fluoroalkylsilazane, fluoroalkylsilane, a fluorine-containing silicon-based compound, and a perfluoropolyether group-containing silane coupling agent. By imparting water repellency and / or oil repellency to the antiglare layer 26 with these materials, the antifouling property of the optical sheet 130E and the pressure-sensitive adhesive sheet 100E can be enhanced.

[0079] The antiglare layer 26 may be formed as a layer in which a layer having a relatively high refractive index and a layer having a relatively low refractive index are laminated in this order from the side of the ultraviolet-absorbing transparent base material 17 by unevenly distributing the material. The antiglare layer 26 with unevenly distributed material can be formed, for example, by applying a composition containing a low refractive index material containing surface-modified silica fine particles or hollow silica fine particles and a high refractive index material, and phase-separating them using the difference in surface free energy between the two. When the antiglare layer 26 is composed of two such separated layers, the refractive index of the relatively high refractive index layer on the side of the colored adhesive layer 11 is preferably 1.50 to 2.40, and the refractive index of the relatively low refractive index layer on the surface side of the antiglare layer 26 is preferably 1.20 to 1.55.

[0080] The adhesive sheet 100E and the optical sheet 130E are configured such that a separate and desired optical device or optical material can be installed on the surface 11b of the colored adhesive layer 11. That is, the adhesive sheet 110E includes the colored adhesive layer 11, the ultraviolet-absorbing transparent base material 17, the antiglare layer 26, and the coating layer 15-1. Although not shown, the coating layer 15-1 of the adhesive sheet 110E can be peeled off from the colored adhesive layer 11, and the light-emitting layer 35 can be installed on the surface 11b of the colored adhesive layer 11 without any gaps.

[0081] The adhesive sheets 100E and 110E, the optical sheet 130E, and the display device including the adhesive sheets 100E and 110E described above have the same effects as the adhesive sheets 100A and 110A and the display device 120A of the first embodiment.

[0082] The optical sheet 130E according to the present invention includes the adhesive sheet 100E and an antiglare layer 26 disposed on the incident side of external light with respect to the ultraviolet-absorbing transparent base material 17 of the adhesive sheet 100E and serving as an optical function layer for reducing the reflection of external light. According to the optical sheet 130E, since external light is scattered and diffused in the antiglare layer 26, surface reflection and reflection of external light in the display device or the like to which the optical sheet 130E is applied and its display content can be suppressed. Therefore, according to the optical sheet 130E, the visibility of the display device, the display content, and the display image can be improved, and a decrease in display quality due to reflection of external light can be suppressed.

[0083] Note that the same modifications as those of the pressure-sensitive adhesive sheets 100A and 110A of the first embodiment can also be applied to the pressure-sensitive adhesive sheets 100E and 110E and the optical sheet 130E of the fifth embodiment.

[0084] (Sixth Embodiment) Next, the optical sheet and the like according to the present invention will be described.

[0085] As shown in FIG. 9, the optical sheet 130F according to the present invention includes a pressure-sensitive adhesive sheet 100E, an antiglare layer (optical functional layer, antireflection layer) 26, and a low refractive index layer (optical functional layer, antireflection layer) 24. In the sixth embodiment, the low refractive index layer 24 is provided on the surface 26a on the side opposite to the ultraviolet absorption transparent substrate 17 of the antiglare layer 26 in the thickness direction.

[0086] The optical sheet 130F is configured such that a separate and desired optical device or optical material can be installed on the surface 11b of the colored pressure-sensitive adhesive layer 11. That is, the pressure-sensitive adhesive sheet 110F includes a colored pressure-sensitive adhesive layer 11, an ultraviolet absorption transparent substrate 17, an antiglare layer 26, a low refractive index layer 24, and a coating layer 15-1. Although not shown, the coating layer 15-1 of the pressure-sensitive adhesive sheet 110F can be peeled off from the colored pressure-sensitive adhesive layer 11, and the light-emitting layer 35 can be installed on the surface 11b of the colored pressure-sensitive adhesive layer 11 without a gap.

[0087] The display device including the optical sheet 130F and the pressure-sensitive adhesive sheet 110F described above has the same functions and effects as the pressure-sensitive adhesive sheets 100A and 110A and the display device 120A of the first embodiment.

[0088] The optical sheet 130F according to the present invention includes an adhesive sheet 100E, and an antiglare layer 26 and a low refractive index layer 24 as optical functional layers disposed on the incident side of external light with respect to the ultraviolet absorbing transparent base material 17 of the adhesive sheet 100E. According to the adhesive sheet 110F and the optical sheet 130F, external light is scattered and diffused in the antiglare layer 26, and strong reflection of external light is suppressed in the low refractive index layer 24. Therefore, it is possible to suppress the glare, surface reflection, reflection, etc. of external light in the display device or the like to which the adhesive sheet 110F or the optical sheet 130F is applied and its display content. Therefore, according to the adhesive sheet 110F or the optical sheet 130F, it is possible to improve the visibility of the display device, the display content, and the display image to which these are applied, and suppress the deterioration of the display quality due to the reflection of external light.

[0089] Note that the same modifications as those of the adhesive sheets 100A and 110A of the first embodiment can be applied to the adhesive sheet 110F and the optical sheet 130F of the sixth embodiment.

[0090] As described above, the preferred embodiments of the present invention have been described in detail, but the present invention is not limited to specific embodiments. The present invention can be modified within the scope of the gist of the present invention described in the claims.

[0091] For example, in the adhesive sheet according to the present invention, the colored adhesive layer preferably contains at least one of a radical scavenger, a peroxide decomposer, and a singlet oxygen quencher. Each type of the radical scavenger, the peroxide decomposer, and the singlet oxygen quencher is not limited to the substances described above, and may be changed to appropriate substances.

[0092] For example, the optical functional layer that is disposed on the incident side of external light with respect to the ultraviolet absorption layer of the pressure-sensitive adhesive sheet according to the present invention and reduces the reflection of external light is not limited to the above-described low refractive index layer or antiglare layer. The optical functional layer may be a high refractive index layer (optical functional layer, antireflection layer), an antistatic layer, or an antifouling layer. That is, the optical sheet according to the present invention may further include an antistatic layer or an antifouling layer. The high refractive index layer has a refractive index lower than that of the ultraviolet absorption transparent substrate 17, and is provided to reduce the reflection of external light incident on the optical sheet (i.e., reflection to the observer side), similar to the above-described low refractive index layer. Examples of the constituent material of the high refractive index layer include an active energy ray curable resin, a photopolymerization initiator, a solvent, and the like. The antistatic layer is provided to prevent charging of the pressure-sensitive adhesive sheet or the display device, and contains an antistatic agent. The constituent material of the antistatic layer includes an ionizing radiation curable material, a polymerization initiator, and an antistatic agent. Examples of the antistatic agent include metal oxide-based fine particles such as antimony-doped tin oxide (ATO) and indium tin oxide (ITO) doped with tin, a polymer type conductive composition, and a quaternary ammonium salt. The antifouling layer is provided to prevent adhesion of dirt to the pressure-sensitive adhesive sheet or the display device, and has, for example, water repellency. Examples of the constituent material of the antifouling layer include silicon oxide, a fluorine-containing silane compound, fluoroalkylsilazane, fluoroalkylsilane, a fluorine-containing silicon-based compound, and a perfluoropolyether group-containing silane coupling agent. The optical sheet according to the present invention may include all of the optical functional layer, the antistatic layer, and the antifouling layer. Further, in the optical sheet according to the present invention, an arbitrary layer that does not significantly affect the hue of the pressure-sensitive adhesive sheet and has a desired function may be provided on the pressure-sensitive adhesive sheet.

[0093] For example, the configurations of the above-described embodiments may be appropriately combined. As an example, an optical functional layer such as a low refractive index layer or an antiglare layer may be disposed between the oxygen barrier layer and the ultraviolet absorption transparent substrate of the pressure-sensitive adhesive sheet of the third embodiment.

[0094] In addition, the light-emitting layer of the display device according to the present invention is not limited to the layer provided with the organic EL element, and may be provided with a white LED element, an inorganic phosphor light-emitting element, a quantum dot light-emitting element, or the like. The configuration of the light-emitting layer is not limited to the configuration including a light-emitting element that emits white light and a color filter, and may be, for example, a configuration having a light-emitting element capable of emitting light of each color of red (R), green (G), and blue (B).

Example

[0095] Examples will be described below. However, the present invention is not limited by the following examples.

[0096] In the following examples and comparative examples, optical sheets 1 to 19 having the layer configurations shown in [Table 1] and [Table 2] were produced, and the characteristics of the produced optical sheets 1 to 16 were evaluated. In addition, using optical sheets 5, 13, and 17 to 19, the display device characteristics of the organic EL panel were confirmed by simulation.

[0097]

Table 1

[0098]

Table 2

[0099] <Production of optical sheet> The formation method of each layer will be described below.

[0100] (Base material) The following were used as the base material. ·TAC: Triacetyl cellulose film (product name; TG60UL, manufactured by Fuji Film Co., Ltd., base material thickness 60 μm, ultraviolet shielding rate 92.9%) ·PMMA1: Polymethyl methacrylate film (product name; W001U80, manufactured by Sumitomo Chemical Co., Ltd., base material thickness 80 μm, ultraviolet shielding rate 93.4%) ·PMMA2: Poly(methyl methacrylate) film (product name; W002N80, manufactured by Sumitomo Chemical Co., Ltd., substrate thickness 80 μm, UV shielding rate 13.9%) ·PET1: Polyethylene terephthalate film (product name; SRF, manufactured by Toyobo Co., Ltd., substrate thickness; 80 μm, UV shielding rate; 88.3%) ·PET2: Polyethylene terephthalate film (product name; TOR20, manufactured by SKC Co., Ltd., substrate thickness; 40 μm, UV shielding rate; 88.6%)

[0101] (Fabrication of the optical functional layer) [Formation of the oxygen barrier layer] On the structure of Example 3 shown in [Table 1], an 80% by mass aqueous solution of PVA117 (manufactured by Kuraray Co., Ltd.) was applied and dried to form an oxygen barrier layer with an oxygen permeability of 1 cc / m 2 ·day·atm.

[0102] [Formation of the hard coat layer] (Composition for hard coat formation) The following materials were used as the raw materials for the composition for hard coat layer formation used for forming the hard coat layer, and the composition shown in [Table 3] was prepared. ·Actinic energy ray curable resin: UA-306H (manufactured by Kyoeisha Chemical Co., Ltd., pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer) DPHA (dipentaerythritol hexaacrylate) PETA (pentaerythritol triacrylate) ·Initiator: Omnirad TPO (product name; manufactured by IGM Resins, B.V.) Omnirad 184 (product name; manufactured by IGM Resins, B.V.) ·Solvent: MEK (methyl ethyl ketone) Methyl acetate

[0103]

Table 3

[0104] On the base material of the optical sheet or the oxygen barrier layer shown in [Table 1] and [Table 2], the composition for forming a hard coat layer shown in [Table 3] was applied, dried in an oven at 80 °C for 60 seconds, and then irradiated with ultraviolet rays using an ultraviolet irradiation device at an irradiation dose of 150 mJ / cm 2 by ultraviolet irradiation (manufactured by Fusion UV Systems Japan, light source H bulb) to cure the coating film, and the hard coat layers 1 and 2 described in [Table 1] with a film thickness of 5.0 μm after curing were formed.

[0105] [Formation of antiglare layer] (Composition for forming antiglare layer) The following composition was used as the composition for forming an antiglare layer used for forming the antiglare layer. · Actinic energy ray curable resin: Light acrylate PE-3A (manufactured by Kyoeisha Chemical Co., Ltd., refractive index 1.52) 43.7 parts by mass · Photoinitiator: Omnirad TPO (manufactured by IGM Resins B.V.) 4.55 parts by mass · Resin particles: Styrene-methyl methacrylate copolymer particles (refractive index 1.515, average particle size 2.0 μm) 0.5 part by mass · Inorganic fine particles 1: Synthetic smectite 0.25 part by mass · Inorganic fine particles 2: Alumina nanoparticles, average particle size 40 nm 1.0 part by mass · Solvent Toluene 15 parts by mass Isopropyl alcohol 35 parts by mass

[0106] On the base materials of the optical sheets of Examples 7 and 8 shown in [Table 1], the composition for forming an antiglare layer having the above composition was applied, dried in an oven at 80 °C for 60 seconds, and then irradiated with ultraviolet rays using an ultraviolet irradiation device at an irradiation dose of 150 mJ / cm 2 by ultraviolet irradiation (manufactured by Fusion UV Systems Japan, light source H bulb) to cure the coating film, and the antiglare layer of [Table 1] with a film thickness of 5.0 μm after curing was formed.

[0107] [Formation of low refractive index layer] (Composition for forming low refractive index layer) The following composition was used as the composition for forming a low refractive index layer used for forming the low refractive index layer. ·Refractive index adjuster: Dispersion of porous silica fine particles (average particle diameter; 75 nm, solid content 20%, solvent methyl isobutyl ketone) 8.5 parts by mass ·Antifouling agent: Optool AR-110 (manufactured by Daikin Industries, Ltd., solid content 15%, solvent methyl isobutyl ketone) 5.6 parts by mass ·Active energy ray curable resin: Pentaerythritol triacrylate 0.4 parts by mass ·Initiator: Omnirad 184 (product name; manufactured by IGM Resins, B.V.) 0.07 parts by mass ·Leveling agent: RS-77 (manufactured by DIC Corporation) 1.7 parts by mass ·Solvent: Methyl isobutyl ketone 83.73 parts by mass

[0108] The composition for forming a low refractive index layer having the above composition was applied onto the hard coat layer or the antiglare layer of the optical sheet shown in [Table 1] and [Table 2], dried in an oven at 80 °C for 60 seconds, and then irradiated with ultraviolet rays using an ultraviolet irradiation device (manufactured by Fusion UV Systems Japan, light source; H bulb) at an irradiation dose of 200 mJ / cm 2 to cure the coating film, thereby forming the low refractive index layers of [Table 1] and [Table 2] having a film thickness of 100 nm after curing.

[0109] [Preparation of adhesive layer (colored adhesive layer)] (Preparation of base adhesive) The following composition was used as the base adhesive. ·Adhesive resin: Solution of butyl acrylate (BA) / hydroxyethyl methacrylate (HEMA) copolymer dissolved in ethyl acetate 70 parts by mass · Hardener: Isocyanate-based crosslinking agent 0.037 parts by mass · Additive: Silane-based coupling agent 0.048 parts by mass · Solvent: Methyl ethyl ketone (MEK) 30 parts by mass

[0110] (Composition for forming adhesive layer) The following materials were used as the materials for the composition for forming an adhesive layer used for forming a colored adhesive layer, and the compositions shown in [Table 4] were prepared. The maximum absorption wavelength and half-value width of the colorant were calculated from the spectral transmittance as the characteristic values in the colored adhesive layer. · Base adhesive · First colorant: Dye-1 Pyromethene cobalt complex dye represented by the following chemical formula (1) (maximum absorption wavelength; 493 nm, half-value width; 26 nm) · Second colorant: Dye-2 Tetraazaporphyrin copper complex dye (product name; PD-311S, manufactured by Yamamoto Kasei Co., Ltd., maximum absorption wavelength; 584 nm, half-value width; 17 nm) Dye-3 Tetraazaporphyrin copper complex dye (product name; FDG-007, manufactured by Yamada Chemical Co., Ltd., maximum absorption wavelength; 593 nm, half-value width; 18 nm) · Third colorant: Dye-4 Phthalocyanine copper complex dye (product name; FDN-002, manufactured by Yamada Chemical Co., Ltd., maximum absorption wavelength; 800 nm, minimum transmittance wavelength at 400 - 780 nm; 780 nm) Dye-5 Phthalocyanine cobalt complex dye (product name; FDR-002, manufactured by Yamada Chemical Co., Ltd., maximum absorption wavelength; 683 nm, minimum transmittance wavelength at 400 nm or more and 780 nm or less; 683 nm) · Additive: Hindered amine light stabilizer Chimassorb944FDL (manufactured by BASF Japan, molecular weight; 2000 - 3100) Hindered amine light stabilizer Tinuvin249 (manufactured by BASF Japan, molecular weight; 482) Singlet oxygen quencher D1781 (manufactured by Tokyo Chemical Industry Co., Ltd.) · UV absorber: Tinuvin479 (manufactured by BASF Japan) LA-36 (manufactured by ADEKA) · Adhesive: The base adhesive prepared above · Solvent: Methyl acetate

[0111]

Chemical formula

[0112]

Table 4

[0113] (Preparation of colored adhesive layer and optical sheet) The adhesive obtained as described above was coated on a release base film to a film thickness of 25 μm during drying, and after being sufficiently dried, the release film was laminated to obtain a colored adhesive layer. The release film on one side of the obtained colored adhesive layer was peeled off and bonded to a support of non-alkali glass with a thickness of 0.7 mm. Then, the release film on the other side of the colored adhesive layer was peeled off, and the substrates laminated with the functional layers shown in [Table 1] and [Table 2] were bonded together to trial-produce optical sheets 1 to 19.

[0114] [Optical sheet property evaluation] (On the colored adhesive layer, ultraviolet shielding rate) Regarding the optical functional layers including the substrates that are the upper layers of the colored adhesive layers of Examples 1 to 13 and Comparative Examples 1 to 3, the transmittance was measured using an automatic spectrophotometer (manufactured by Hitachi, Ltd., U-4100). Based on these transmittances, the average transmittance in the ultraviolet region (wavelength band; 290 to 400 nm) was calculated, and the ultraviolet shielding rate [%] was calculated as the value obtained by subtracting the average transmittance [%] in the ultraviolet region (290 nm to 400 nm) from 100%.

[0115] (Pencil hardness test) Using a Clements type scratch hardness tester (manufactured by Tester Sangyo Co., Ltd., HA-301), a test was conducted on the surface of the optical sheet using a pencil (UNI manufactured by Mitsubishi Pencil Co., Ltd., pencil hardness H) with a load of 500 gf (4.9 N) applied in accordance with JIS-K5600-5-4:1999 (hereinafter referred to as the 500 g load). The change in appearance due to scratches was visually evaluated. When no scratches were observed, it was rated as good (described as "○" in [Table 5] and [Table 6] below), and when scratches were observed, it was rated as bad (described as "×" in [Table 5] and [Table 6] below).

[0116] (Lightfastness test) As a reliability test for the prototype optical sheet, a xenon weather meter tester (manufactured by Suga Test Instruments Co., Ltd., X75) was used, and the test was conducted for 120 hours under the conditions of a xenon lamp illuminance of 60 W / cm 2 (300 - 400 nm), a test chamber temperature of 45 °C, and a humidity of 50% RH. Before and after the test, transmittance measurements were taken using an automatic spectrophotometer (manufactured by Hitachi, Ltd., U-4100). The transmittance differences ΔTλ1 before and after the test at the wavelength λ1 representing the minimum transmittance before the test in the wavelength range of 470 - 530 nm, ΔTλ2 before and after the test at the wavelength λ2 indicating the minimum transmittance before the test in the wavelength range of 560 - 620 nm, and ΔTλ3 before and after the test at the wavelength λ3 showing the minimum transmittance before the test in the wavelength range of 650 - 780 nm were calculated. The closer the transmittance difference is to zero, the better. It is preferable that |ΔTλN| ≦ 20 (N = 1 - 3), and more preferably |ΔTλN| ≦ 10 (N = 1 - 3).

[0117] The results of evaluating the above items are shown in [Table 5] and [Table 6].

[0118]

Table 5

[0119]

Table 6

[0120] As shown in [Table 5] and [Table 6], the light resistance of the colored adhesive layer containing the first to third color materials was significantly improved by providing an ultraviolet absorption layer with an ultraviolet shielding rate of 85% or more on the upper layer. Providing the ultraviolet absorption ability in the colored adhesive layer has little effect, and it is preferable to form it as a separate layer on the upper layer. Further, by laminating an oxygen barrier layer and containing a high molecular weight hindered amine light stabilizer as a radical scavenger and a nickel complex of dialkyldithiocarbamate as a singlet oxygen quencher in the colored adhesive layer, the light resistance of the colored adhesive layer was further improved.

[0121] [Display Device Characteristics Evaluation] The following evaluations were performed on the prototype optical sheets 5, 13, and 17 to 19.

[0122] (White Display Transmittance Characteristics) The transmittance of the prototype optical sheet was measured using an automatic spectrophotometer (manufactured by Hitachi, Ltd., U-4100). Using this transmittance, the efficiency of the light transmitted through the optical sheet during white display was calculated and evaluated as the white display transmittance characteristics. Regarding the above-mentioned efficiency, when the light intensity at each wavelength during white display emitted from a white organic EL light source (hereinafter sometimes referred to as an organic EL light source) and output through a color filter is set to 100, it is calculated as the ratio of the light intensity value at each wavelength of the light transmitted through the optical sheet. The higher the light intensity ratio, the higher the luminance efficiency of the light source. The spectrum of the light emitted from the organic EL light source is shown in FIG. 10.

[0123] (Display Device Reflection Characteristics 1) For the prototype optical sheet, the transmittance T(λ) and the surface reflectance R2(λ) were measured using an automatic spectrophotometer (manufactured by Hitachi, Ltd., U-4100). Regarding the measurement of the surface reflectance R2(λ), an anti-reflection treatment was performed by applying a matte black paint to the surface of the glass, which is the adherend, where the colored adhesive layer is not formed, and the spectral reflectance was measured at an incident angle of 5°, and the surface reflectance R2(λ) was obtained. The electrode reflectance R EWith (λ) set to 100% for all wavelengths from 380 nm to 780 nm, the relative reflectance when the panel reflectance with respect to the D65 light source without placing the optical sheet is set to 100 was calculated based on the above equations (4), (5), (7), and (9) without considering the interface reflection and surface reflection in each layer, and was evaluated as the display device reflection characteristic 1. The lower the relative reflectance, the smaller the intensity of the reflected light and the higher the display quality.

[0124] (Display device reflection hue 1) The transmittance T(λ) and surface reflectance R2(λ) of the prototype optical sheet were measured using an automatic spectrophotometer (manufactured by Hitachi, Ltd., U-4100). For the measurement of the surface reflectance R2(λ), a matte black paint was applied to the surface where the colored adhesive layer of the glass as the adherend was not formed to perform an antireflection treatment, and the spectral reflectance was measured at an incident angle of 5°, and it was taken as the surface reflectance R2(λ). The electrode reflectance R E (λ) was set to 100% for all wavelengths from 380 nm to 780 nm, and the chromaticity index (value) a * and b * of the reflection hue with respect to the D65 light source were calculated based on the above equations (1) to (9) without considering the interface reflection and surface reflection in each layer, and were evaluated as the display device reflection hue 1. The closer a * and b * are to zero, the less colored and the better, and it is preferably within -5 to +5.

[0125] (Display device reflection characteristic 2) The electrode reflectance R E (λ) was taken as the electrode reflectance obtained from the reflectance measurement of the organic light-emitting display device (organic EL TV manufactured by LG Electronics, OLED55C8PJA) shown in FIG. 11, and the result calculated in the same manner as the display device reflection characteristic 1 was evaluated as the display device reflection characteristic 2. Similar to the display device reflection characteristic 1, the lower the relative reflectance, the smaller the intensity of the reflected light and the higher the display quality.

[0126] (Display device reflection hue 2) The electrode reflectance R EThe result calculated in the same manner as the display device reflection hue 1 was evaluated as the display device reflection characteristic 2, except that (λ) was taken as the electrode reflectance obtained from the reflectance measurement of the organic light-emitting display device (organic EL TV manufactured by LG Electronics, OLED55C8PJA) shown in FIG. 11. Similar to the display device reflection hue 1, a * and b * are preferably closer to zero, indicating less color tint and better quality, and preferably within the range of -5 or more and +5 or less.

[0127] (Color reproducibility) The transmittance of the prototype optical sheet was measured using an automatic spectrophotometer (U-4100 manufactured by Hitachi, Ltd.), and the NTSC ratio was calculated from the CIE1931 chromaticity values calculated using this transmittance and the red display, green display, and blue display spectra shown in FIG. 12 output through the organic EL light source and color filter of the spectrum shown in FIG. 10, and evaluated as color reproducibility. The higher the NTSC ratio, the wider the color reproducibility, which is preferable.

[0128] The results of evaluating the above items are shown in the following [Table 7].

[0129]

Table 7

[0130] As shown in [Table 7], the reflection characteristics of the display device equipped with the colored adhesive layer were significantly reduced. Also, while it is said that the transmittance is halved in the circular polarizing plate, as shown in the evaluation value of the white display transmittance, the display device equipped with the colored adhesive layer is also excellent in luminance efficiency and further improves color reproducibility. In addition, the display device equipped with the colored adhesive layer including the first, second, and third color materials shown in this example has an electrode reflectance R E (λ) is the chromaticity index a of the reflection hue when the reflectance is 100% at all wavelengths from 380 nm to 780 nm * and b *It was possible to adjust the absorption intensity of the colorant so that each of them was in the range of -5 or more and +5 or less. That is, it was possible to make the reflected hue closer to neutral. Also, it was shown that this characteristic can maintain the reflected hue as neutral even in the display device reflected hue 2 changed to the electrode reflectance of an actual organic light-emitting display device, and it was confirmed that the display quality of the display device can be improved. As described above, adjusting the mixing ratios of the first, second, and third colorants with respect to the electrode reflectances of organic light-emitting display devices having various wavelength dispersions to make the reflected hue of the optical sheet provided with the colored adhesive layer neutral is also an aspect of the present invention.

[0131] As described above, the preferred embodiments and modifications of the present invention have been described together with examples, but the present invention is not limited to each embodiment and each example. Additions, omissions, substitutions, and other changes to the configuration are possible without departing from the spirit of the present invention. Also, the present invention is not limited by the foregoing description and is limited only by the appended claims.

Explanation of Reference Numerals

[0132] 11 Colored adhesive layer 13 Ultraviolet-absorbing adhesive layer (ultraviolet-absorbing layer) 17 Ultraviolet-absorbing transparent substrate (ultraviolet-absorbing layer) 100A, 100A´, 100B, 100C, 100D, 100E, 110A, 110B, 110C, 110D, 110E, 110F Adhesive sheet 120A, 120A´ Display device 130D, 130E, 130F Optical sheet

Claims

1. An adhesive layer forming composition containing an adhesive and a pigment, The pigment contains a first colorant having a maximum absorption wavelength in the range of 470 nm or more and 530 nm or less and a half-value width of the absorption spectrum of 15 nm or more and 45 nm or less, a second colorant having a maximum absorption wavelength in the range of 560 nm or more and 620 nm or less and a half-value width of the absorption spectrum of 15 nm or more and 55 nm or less, and a third colorant having the wavelength with the lowest transmittance in the wavelength range of 400 to 780 nm in the range of 650 nm or more and 780 nm or less, In an adhesive sheet having a colored adhesive layer with a thickness of 25 μm formed by the adhesive layer forming composition and an ultraviolet absorption layer provided on one surface of the colored adhesive layer and having an ultraviolet shielding rate of 85% or more in accordance with JIS L 1925, the hue values a ＊ and b ＊ are each in the range of -5 or more and +5 or less, Adhesive layer forming composition. [Equation 1] [Equation 2] [Equation 3] [Equation 4] [Equation 5] [Equation 6] [Equation 7] [Equation 8] [Equation 9] Here, λ is a variable representing wavelength, and t is the ratio of X ｎ , Y ｎ , Z ｎ to X, Y, Z. a calculated from formulas (1) to (3) ＊ , b ＊ are CIE1976L ＊ a ＊ b ＊It is calculated according to the calculation method in the color space (CIELAB color space). In formulas (1) and (2), X ｎ , Y ｎ , Z ｎ are the three stimulus values at the white point of the D65 light source. In formula (4), R Ｅ (λ) represents a function of the reflectance [%] on a perfectly diffusing reflecting surface (100% for each wavelength), R2(λ) represents a function of the surface reflectance [%] on the outermost surface of the pressure-sensitive adhesive sheet on the side opposite to the side in contact with the colored pressure-sensitive adhesive layer with respect to the ultraviolet absorption layer, and T(λ) represents a function of the transmittance [%] of the pressure-sensitive adhesive sheet. In formulas (6) to (9), P Ｄ６５ (λ) is the D65 light source spectrum, and overline x(λ), overline y(λ), and overline z(λ) are the equal-color functions in the CIE1931 2° field of view. The definite integrals in formulas (6) to (9) may be obtained by appropriate numerical integration. For example, the wavelength interval in the case of performing numerical integration may be 1 nm interval.

2. The pressure-sensitive adhesive sheet has, before and after a light resistance test in which light with a wavelength of 300 to 400 nm is irradiated at a xenon lamp illuminance of 60 W / cm ２ under the conditions of a temperature of 45°C and a humidity of 50% RH for 120 hours, the transmittance difference ΔTλ1 at the wavelength λ1 showing the minimum transmittance before the test in the wavelength range of 470 nm to 530 nm, the transmittance difference ΔTλ2 at the wavelength λ2 showing the minimum transmittance before the test in the wavelength range of 560 nm to 620 nm, and the transmittance difference ΔTλ3 at the wavelength showing the minimum transmittance before the test in the wavelength range of 650 nm to 780 nm, all of which are 20 points or less. The composition for forming an adhesive layer according to claim 1.

3. Contains at least one of a radical scavenger, a peroxide decomposer, and a singlet oxygen quencher as an additive. The composition for forming an adhesive layer according to claim 1 or 2.

4. Contains a hindered amine-based light stabilizer having a molecular weight of 2000 or more as the radical scavenger. The composition for forming an adhesive layer according to claim 3.

5. As the singlet oxygen quencher, containing any one of dialkyl phosphate, dialkyldithiocarbamate, benzenedithiol, and transition metal complexes thereof The composition for forming an adhesive layer according to claim 3.

6. The dye contains at least one or more compounds selected from the group consisting of compounds having any one of a porphyrin structure, a merocyanine structure, a phthalocyanine structure, an azo structure, a cyanine structure, a squarylium structure, a coumarin structure, a polyene structure, a quinone structure, a tetradiporphyrin structure, a pyromethene structure, and an indigo structure, and metal complexes thereof. The composition for forming an adhesive layer according to claim 1.

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