Retardation laminate and optical laminate

Abstract

To achieve both improved visibility in an optical laminate, including suppression of interference unevenness, and enhanced flex resistance.SOLUTION: A retardation laminate includes, in this order, a first liquid-crystal retardation layer, a second adhesion layer having a thickness of 20-200 nm, and a second liquid-crystal retardation layer. The peel strength between the first liquid-crystal retardation layer and the second liquid-crystal retardation layer is at least 0.20 N / 25 mm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a retardation layer laminate and an optical laminate. [Background technology]

[0002] Conventionally, an optical laminate in which a polarizer and a plurality of liquid crystal retardation layers are laminated for the purpose of anti-reflection has been known as a circular polarizing plate for OLED applications. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-052365 [Patent Document 2] Japanese Patent Publication No. 2023-068424 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional circular polarizers have problems such as interference irregularities being visible to the naked eye, and when applied to foldable displays, repeated bending at the same location can cause wrinkle defects in the components at the bent portions.

[0005] The present invention has been made in view of the above problems, and aims to achieve both improved visibility (interference unevenness, etc.) and bending resistance in an optical laminate. [Means for solving the problem]

[0006] [1] A retardation layer laminate having, in this order, a first liquid crystal retardation layer, a second bonding layer having a thickness of 20 to 200 nm, and a second liquid crystal retardation layer, A retardation layer laminate in which the peel strength between the first liquid crystal retardation layer and the second liquid crystal retardation layer is 0.20 N / 25 mm or more. [2] The retardation layer laminate according to [1], wherein the second attachment layer is a polyvinyl alcohol-based resin layer. [3] The retardation layer laminate according to [1] or [2], wherein the thickness of the first liquid crystal retardation layer and the second liquid crystal retardation layer is 5 μm or less. [4] A first base layer provided on the opposite side of the first liquid crystal retardation layer from the second bonding layer; a second base material layer provided on the opposite side of the second liquid crystal retardation layer from the second bonding layer, and at least one of the first base material layer and the second base material layer has a moisture permeability of 200 g / m 2 The retardation layer laminate according to any one of [1] to [3], wherein the retardation layer laminate has a temperature of 100°C or more. [5] a step of laminating the first liquid crystal retardation layer and the second liquid crystal retardation layer by passing them between a pair of rolls while supplying an aqueous adhesive composition containing water and a resin dissolved or dispersed in water between the first liquid crystal retardation layer and the second liquid crystal retardation layer to obtain a laminate including the first liquid crystal retardation layer, the liquid film, and the second liquid crystal retardation layer; The method for producing a retardation layer laminate according to any one of [1] to [4], further comprising a step of drying the liquid film in the laminate. [6] A first protective layer, a linear polarizer, a second protective layer, a first attaching layer, and a retardation layer laminate in this order; the retardation layer laminate has a first liquid crystal retardation layer, a second attachment layer having a thickness of 20 to 200 nm, and a second liquid crystal retardation layer in this order from the first attachment layer side, The optical laminate, wherein the peel strength between the first liquid crystal retardation layer and the second liquid crystal retardation layer is 0.20 N / 25 mm or more. [7] The optical laminate according to [6], wherein the arithmetic mean roughness Ra of the first attaching layer on the side of the retardation layer laminate is 35 nm or less. [8] The optical laminate according to [6] or [7], wherein the first attaching layer is a pressure-sensitive adhesive layer. [9] The optical laminate according to any one of [6] to [8], wherein the angle θ between the slow axis of the first liquid crystal retardation layer and the transmission axis of the linear polarizer is 10° to 20° or −10° to −20°.

[10] The optical laminate according to any one of [6] to [9], wherein when the in-plane retardation value of the retardation layer laminate for light with a wavelength of λ nm is Re(λ), the relationship between the following formulas (1) and (2) is satisfied. 70nm≦Re(450)≦150nm (1) Re(450) / Re(550)≦1.0 (2) [Effects of the Invention]

[0007] According to the present invention, the visibility (interference unevenness, etc.) of the optical laminate is improved, and the bending resistance is improved. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an embodiment of a retardation layer laminate 300 and an optical laminate 400. As shown in FIG. [Figure 2] FIG. 2 is a schematic cross-sectional view showing a method for manufacturing the retardation layer laminate 300. [Figure 3] FIG. 2 is a schematic diagram illustrating a method for evaluating flexibility. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Optical laminate (circular polarizer) 400) As shown in FIG. 1, the optical laminate 400 according to the embodiment includes a first protective layer 180, a linear polarizer 220, a second protective layer 190, a first bonding layer 150, and a retardation layer laminate 300 in this order, and can function as a circular polarizer.

[0010] (Linear polarizer 220) A linear polarizer has the function of selectively transmitting linearly polarized light in a certain direction from unpolarized light such as natural light. Examples of linear polarizers include a film (hereinafter also referred to as a "polarizer") obtained by uniaxially stretching a polymer such as PVA impregnated with iodine or an organic dichroic dye, and an optically anisotropic layer (hereinafter also referred to as a "polarizing film") formed by orienting a dichroic dye and a polymerizable liquid crystal compound.

[0011] The polarization performance of a linear polarizer can be measured using a spectrophotometer. For example, the transmittance (T) in the direction of the transmission axis (direction perpendicular to the orientation) in the visible light wavelength range of 380 nm to 780 nm can be calculated by 1 ) and transmittance in the absorption axis direction (orientation direction) (T 2 ) can be measured by the double beam method using a spectrophotometer equipped with a prism polarizer. Polarization performance in the visible light range can be calculated by calculating the single transmittance and degree of polarization at each wavelength using the following formulas (Formula 1) and (Formula 2), and then performing luminosity correction using the 2-degree visual field (C light source) of JIS Z 8701 to calculate the luminosity-corrected single transmittance (Ty) and luminosity-corrected degree of polarization (Py). In addition, the color matching function for C light source can be used to calculate the L from the transmittance measured in the same way. * a * b * Chromaticity a in the (CIE) color system * and b * By calculating the above, the hue of the linear polarizer alone (single hue), the hue of the linear polarizers arranged in parallel (parallel hue), and the hue of the linear polarizers arranged orthogonally (orthogonal hue) can be obtained. * and b * The closer the value is to 0, the more neutral the hue is. Single transmittance (%) = (T1 + T2) / 2 (Equation 1) Polarization degree (%) = (T1-T2) / (T1+T2)×100 (Equation 2)

[0012] The luminosity-corrected polarization degree Py of the linear polarizer is usually 80% or more, preferably 90% or more, more preferably 95% or more, even more preferably 98% or more, particularly preferably 99% or more, and may be 99.9% or more. Increasing the luminosity-corrected polarization degree Py of the linear polarizer is advantageous in improving the antireflection function of the optical laminate. If the luminosity-corrected polarization degree Py is less than 80%, the antireflection function may not be achieved when used as an antireflection film.

[0013] The higher the luminous-effect-corrected single transmittance Ty of the linear polarizer, the greater the clarity of the white display. However, as can be seen from the relationship between (Equation 1) and (Equation 2), if the single transmittance is too high, the degree of polarization decreases. Therefore, the single transmittance is preferably 30% to 60%, more preferably 35% to 55%, even more preferably 38% to 50%, still more preferably 40% to 45%, and most preferably 41% to 43%. If the luminous-effect-corrected single transmittance Ty is too high, the luminous-effect-corrected polarization degree Py will be too low, which may result in insufficient anti-reflection function when used as an anti-reflection film.

[0014] <Polarizer> A film obtained by uniaxially stretching a polymer such as a polyvinyl alcohol-based resin film (PVA) impregnated with iodine or an organic dichroic dye can usually be produced through the following steps: uniaxially stretching the polyvinyl alcohol-based resin film; dyeing the polyvinyl alcohol-based resin film with a dichroic dye such as iodine to adsorb the dichroic dye; treating the polyvinyl alcohol-based resin film with the adsorbed dichroic dye with a crosslinking agent such as a boric acid aqueous solution; and washing with water after the treatment with the crosslinking agent such as a boric acid aqueous solution.

[0015] The thickness of the polarizer is usually 30 μm or less, preferably 18 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. The thickness is usually 1 μm or more, and may be, for example, 5 μm or more.

[0016] The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after dyeing with a dichroic dye. When uniaxial stretching is performed after dyeing, it may be performed before or during the boric acid treatment. Of course, uniaxial stretching can also be performed in multiple stages as shown here. Examples of uniaxial stretching include uniaxial stretching in the film transport direction between rolls with different peripheral speeds, uniaxial stretching in the film transport direction using a heated roll, and stretching in the width direction using a tenter. The uniaxial stretching may be performed by dry stretching in the air, or by wet stretching in a swollen state using a solvent such as water. The stretching ratio is usually about 3 to 8 times. Alternatively, an aqueous solution containing polyvinyl alcohol may be applied to a thermoplastic resin film, followed by drying, and then stretched together with the thermoplastic resin film by the above-mentioned method.

[0017] Dyeing of a polyvinyl alcohol-based resin film with a dichroic dye can be carried out, for example, by immersing the polyvinyl alcohol-based resin film in an aqueous solution containing the dichroic dye. Specific examples of the dichroic dye include iodine and dichroic organic dyes. It is preferable that the polyvinyl alcohol-based resin film be immersed in water to swell it before dyeing.

[0018] When iodine is used as the dichroic dye, a method of dyeing a polyvinyl alcohol resin film by immersing it in an aqueous solution containing iodine and potassium iodide is usually employed. The iodine content in this aqueous solution is usually about 0.01 to 1 part by mass per 100 parts by mass of water, and the potassium iodide content is usually about 0.5 to 20 parts by mass per 100 parts by mass of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40°C. The immersion time in this aqueous solution (dyeing time) is usually about 20 to 1,800 seconds.

[0019] On the other hand, when a dichroic organic dye is used as the dichroic pigment, a method of dyeing a polyvinyl alcohol-based resin film by immersing it in an aqueous solution containing a water-soluble dichroic organic dye is usually employed. The content of the dichroic organic dye in this aqueous solution is usually about 0.0001 to 10 parts by mass, preferably 0.001 to 1 part by mass, per 100 parts by mass of water. This aqueous dye solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the aqueous dichroic organic dye solution used for dyeing is usually about 20 to 80°C. The immersion time in this aqueous solution (dyeing time) is usually about 10 to 1,800 seconds.

[0020] The boric acid treatment after dyeing with a dichroic dye can be carried out by immersing the dyed polyvinyl alcohol-based resin film in a boric acid-containing aqueous solution. The content of boric acid in the boric acid-containing aqueous solution is usually about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. When iodine is used as the dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide. The content of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. The immersion time in the boric acid-containing aqueous solution is usually about 60 to 1,200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50°C or higher, preferably 50 to 85°C, and more preferably 60 to 80°C.

[0021] The polyvinyl alcohol-based resin film after the boric acid treatment is usually washed with water. The washing can be carried out, for example, by immersing the boric acid-treated polyvinyl alcohol-based resin film in water. The temperature of the water used in the washing is usually about 5 to 40°C. The immersion time is usually about 1 to 120 seconds.

[0022] After washing with water, the polarizer is dried to obtain it. The drying can be performed using a hot air dryer or a far-infrared heater. The temperature for the drying is usually about 30 to 100°C, preferably 50 to 80°C. The drying time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. The drying reduces the moisture content in the polarizer to a practical level. The moisture content is usually about 5 to 20% by mass, preferably 8 to 15% by mass, based on the total mass of the polarizer. When the moisture content is 5% by mass or more, the polarizer has sufficient flexibility, and therefore damage or breakage after drying can be suppressed. Furthermore, when the moisture content is 20% by mass or less, the polarizer has sufficient thermal stability.

[0023] In this manner, a polarizer in which a dichroic dye is adsorbed and oriented in a polyvinyl alcohol-based resin film can be produced.

[0024] <Polarizing film> A polarizing film, i.e., an optically anisotropic layer made of a polymer of a polymerizable liquid crystal compound containing a dichroic dye, can be suitably used for flexible displays, for example, because the hue can be arbitrarily controlled, the thickness can be significantly reduced, and the film is non-shrinkable because it is not stretched or relaxed by heat.

[0025] A polarizing film is formed by applying a polarizing film-forming composition onto an alignment film, optionally formed on a substrate, and orienting the dichroic dye contained in the polarizing film-forming composition. The polarizing film has a thickness of 0.1 μm to 5 μm, more preferably 0.3 μm to 4 μm, and even more preferably 0.5 μm to 3 μm. If the film thickness is thinner than this range, the required light absorption may not be achieved. If the film thickness is thicker than this range, the alignment control force of the alignment film decreases, tending to cause alignment defects. The polarizing film-forming composition may further contain a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesion improver, etc.

[0026] In an optically anisotropic layer in which a dichroic dye and a polymerizable liquid crystal compound are aligned horizontally relative to the substrate surface, the ratio (dichroic ratio) of the absorbance A1(λ) in the alignment direction to the absorbance A2(λ) in the direction perpendicular to the alignment plane for light with a wavelength of λ nm is preferably 7 or more, more preferably 20 or more, and even more preferably 40 or more. The higher this value, the better the absorption selectivity of the polarizing plate. While it depends on the type of dichroic dye, in the case of a liquid crystal cured film cured in a nematic liquid crystal phase state, the ratio is approximately 5 to 10.

[0027] By mixing two or more dichroic dyes with different absorption wavelengths, it is possible to produce polarizing films with various hues and polarizing films that have absorption across the entire visible light range. Polarizing films with such absorption properties can be used in a variety of applications.

[0028] <Polarizing film; polymerizable liquid crystal compound> A polymerizable liquid crystal compound is a compound having a polymerizable group and liquid crystallinity (hereinafter also referred to as polymerizable liquid crystal). The polymerizable group refers to a group that participates in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that can participate in a polymerization reaction by an active radical or acid generated from a photopolymerization initiator, which will be described later. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. Among these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferred, with a methacryloyloxy group or an acryloyloxy group being more preferred. The liquid crystallinity may be thermotropic or lyotropic, but thermotropic liquid crystal is preferred when mixed with a dichroic dye, which will be described later. The polymerizable liquid crystal compound may be a monomer or a polymer obtained by polymerizing dimers or higher.

[0029] When the polymerizable liquid crystal compound is a thermotropic liquid crystal, it may be a thermotropic liquid crystal compound exhibiting a nematic liquid crystal phase or a thermotropic liquid crystal compound exhibiting a smectic liquid crystal phase. From the viewpoint of exhibiting high dichroism, the liquid crystal state exhibited by the polymerizable liquid crystal compound is preferably a smectic phase, and a higher-order smectic phase is more preferable from the viewpoint of improving performance. Among these, higher-order smectic liquid crystal compounds that form a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, or a smectic L phase are more preferred, and higher-order smectic liquid crystal compounds that form a smectic B phase, a smectic F phase, or a smectic I phase are even more preferred. When the liquid crystal phase formed by the polymerizable liquid crystal is one of these higher-order smectic phases, a polarizing film with higher polarization performance can be produced. Furthermore, such polarizing films with high polarization performance exhibit Bragg peaks derived from higher-order structures such as hexatic and crystalline phases in X-ray diffraction measurements. These Bragg peaks are derived from the periodic structure of molecular orientation, and films with periodic intervals of 3 to 6 Å can be obtained. The polarizing film of the present invention preferably contains a polymer of polymerizable liquid crystal oriented in a smectic phase, from the viewpoint of obtaining higher polarization properties.

[0030] The polymerizable liquid crystal compound may be used alone or in combination of two or more. The polymerizable liquid crystal composition containing other compounds described later may contain other polymerizable liquid crystal compounds other than the polymerizable liquid crystal compound as long as the effects of the present invention are not impaired. From the viewpoint of obtaining a polarizing film with a high degree of alignment order, the proportion of the polymerizable liquid crystal compound to the total mass of all polymerizable liquid crystal compounds contained in the polymerizable liquid crystal composition is preferably 51% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

[0031] The content of the polymerizable liquid crystal compound in the composition for forming a polarizing film of the present invention is preferably 40 to 99.9 mass %, more preferably 60 to 99 mass %, and even more preferably 70 to 99 mass %, based on the solid content of the polymerizable liquid crystal composition. When the content of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound tends to be high. In this specification, the solid content refers to the total amount of components of the polymerizable liquid crystal composition excluding the solvent.

[0032] <Polarizing film; dichroic dye> A dichroic dye is a dye that has different absorbance in the long axis direction of the molecule and in the short axis direction. Dichroic dyes preferably have the property of absorbing visible light, and more preferably have an absorption maximum wavelength (λMAX) in the range of 380 to 680 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes, with azo dyes being preferred. Examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, with bisazo dyes and trisazo dyes being preferred. Dichroic dyes may be used alone or in combination. However, to achieve absorption across the entire visible light range, it is preferable to combine two or more dichroic dyes, and more preferably three or more dichroic dyes.

[0033] Examples of azo dyes include compounds represented by formula (I) (hereinafter, also referred to as "compound (I)"). T1-A1(-N=N-A2)pN=N-A3-T2(I) [In formula (I), A1, A2, and A3 each independently represent an optionally substituted 1,4-phenylene group, an optionally substituted naphthalene-1,4-diyl group, an optionally substituted benzoic acid phenyl ester group, an optionally substituted 4,4'-stilbenylene group, or an optionally substituted divalent heterocyclic group; T1 and T2 each represent an electron-withdrawing group or an electron-releasing group, and are positioned at substantially 180° relative to the plane of the azo bond; p represents an integer of 0 to 4; when p is 2 or greater, each A2 may be the same or different; and the -N=N- bond may be replaced with a -C=C-, -COO-, -NHCO-, or -N=CH- bond as long as absorption in the visible range is exhibited.]

[0034] The content of the dichroic dye (the total amount when multiple types are included) is usually 1 to 60 parts by mass, preferably 1 to 40 parts by mass, and more preferably 1 to 20 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound, from the viewpoint of obtaining good light absorption properties. If the content of the dichroic dye is less than this range, light absorption will be insufficient and sufficient polarization performance will not be obtained, whereas if it is more than this range, the alignment of the liquid crystal molecules may be hindered.

[0035] (First protective layer 180 and second protective layer 190) The first protective layer 180 and the second protective layer 190 each have the function of protecting the surface of the linear polarizer 220. A "polarizing plate" is defined as a device having a first protective layer or a second protective layer on one or both sides of a linear polarizer. The protective layer is laminated on the linear polarizer via an adhesive or adhesive layer as necessary. Alternatively, the protective layer may be laminated directly to the linear polarizer 220. Here, "directly laminated" includes a case where the protective layer is laminated to the linear polarizer by the self-adhesive properties of the protective layer. The protective layer may be subjected to a surface treatment (e.g., corona treatment) to improve adhesion to the linear polarizer, or a thin layer such as a primer layer (also called an easy-adhesion layer) may be formed on the protective layer. The adhesive layer and the pressure-sensitive adhesive layer are not particularly limited, and the adhesives and pressure-sensitive adhesives exemplified for the first attaching layer 150 described later can be used.

[0036] The protective layer can be, for example, a resin film that exhibits excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and stretchability. The resin film may also be a thermoplastic resin film. Specific examples of such resins include cellulose-based resins such as triacetyl cellulose; polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone-based resins; polysulfone-based resins; polycarbonate-based resins; polyamide-based resins such as nylon and aromatic polyamide; polyimide-based resins; polyolefin-based resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; cyclic polyolefin-based resins having cyclo- and norbornene structures (also known as norbornene-based resins); (meth)acrylic resins such as polymethyl methacrylate; polyarylate-based resins; polystyrene-based resins; polyvinyl alcohol-based resins; and mixtures thereof. Protective films made of such materials are readily available commercially. In this specification, "(meth)acrylic" refers to either acrylic or methacrylic.

[0037] The second protective layer 190 is preferably a triacetyl cellulose-based resin layer.

[0038] The thickness of the thermoplastic resin film is preferably 0.1 μm to 60 μm, more preferably 0.5 μm to 50 μm, and even more preferably 1 μm to 40 μm. In particular, the thickness of the second protective layer 190 is preferably 35 μm or less, and may be 30 μm or less.

[0039] The thermoplastic resin film can be used by being positioned on the viewing side of the linear polarizer. Therefore, the thermoplastic resin film may be subjected to surface treatments such as hard coating, anti-reflection, anti-sticking, and anti-glare, as needed. Furthermore, the thermoplastic resin film may be subjected to treatments to improve visibility when viewed through polarized sunglasses (typically, by imparting (elliptically) circular polarization or ultra-high retardation). By applying such treatments, excellent visibility can be achieved even when the display screen is viewed through polarized lenses such as polarized sunglasses. Therefore, the retardation film-attached polarizing plate can be suitably applied to image display devices that can be used outdoors.

[0040] A thermoplastic resin film can be produced by stretching a film containing the above-mentioned thermoplastic resin. Examples of stretching processes include uniaxial stretching and biaxial stretching. Examples of stretching directions include the machine direction (MD) of the unstretched film, a direction perpendicular to the MD (TD), and a direction oblique to the MD. Biaxial stretching may be simultaneous biaxial stretching, in which the film is stretched in two directions at the same time, or sequential biaxial stretching, in which the film is stretched in a predetermined direction and then stretched in the other direction. Stretching can be performed, for example, by stretching the film in the longitudinal direction (MD) using two or more pairs of nip rolls with a high peripheral speed at the outlet side, or by gripping both side edges of the unstretched film with chucks and spreading it in the direction perpendicular to the MD (TD). The retardation value and wavelength dispersion can be controlled by adjusting the film thickness or the stretch ratio. The wavelength dispersion value can also be controlled by adding a wavelength dispersion adjuster to the resin.

[0041] The thermoplastic resin film may contain any suitable additive depending on the purpose. Examples of additives include hindered phenol-based, phosphorus-based, and sulfur-based antioxidants, stabilizers such as light stabilizers, UV absorbers, weather stabilizers, and heat stabilizers; reinforcing materials such as glass fiber and carbon fiber; near-infrared absorbers; flame retardants such as tris(dibromopropyl)phosphate, triallyl phosphate, and antimony oxide; antistatic agents such as anionic, cationic, and nonionic surfactants; colorants such as inorganic pigments, organic pigments, and dyes; organic and inorganic fillers; resin modifiers; plasticizers; lubricants; and retardation reducers. The type, combination, and content of the additives contained may be appropriately determined depending on the purpose and desired properties.

[0042] Furthermore, in order to impart desired surface optical properties or other characteristics, a coating layer (surface treatment layer) can be provided on the outer surface of the thermoplastic resin film. Specific examples of the surface treatment layer include a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, and an antifouling layer. The method for forming the surface treatment layer is not particularly limited, and known methods can be used. The surface treatment layer may be formed on one surface or both surfaces of the thermoplastic resin film.

[0043] [Hard coat layer] The hard coat layer has the function of increasing the surface hardness of the thermoplastic resin film and is provided for the purpose of preventing surface scratches, etc. The hard coat layer preferably has a pencil hardness of H or harder as measured by the pencil hardness test specified in JIS K 5600-5-4:1999 "General test methods for coatings - Part 5: Mechanical properties of coating films - Section 4: Scratch hardness (pencil method)" (measurement is performed by placing an optical film having a hard coat layer on a glass plate).

[0044] Materials for forming the hard coat layer are generally cured by heat or light. Examples include organic hard coat materials such as organic silicone-based, melamine-based, epoxy-based, (meth)acrylic-based, and urethane (meth)acrylate-based materials, and inorganic hard coat materials such as silicon dioxide. Among these, urethane (meth)acrylate-based or polyfunctional (meth)acrylate-based hard coat materials are preferably used because of their good adhesion to thermoplastic resin films and excellent productivity. In this specification, (meth)acrylate means either acrylate or methacrylate.

[0045] The hard coat layer may contain various fillers as desired for the purposes of adjusting the refractive index, improving the flexural modulus, stabilizing the volume shrinkage rate, and further improving heat resistance, antistatic properties, antiglare properties, etc. The hard coat layer may also contain additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, leveling agents, and antifoaming agents.

[0046] The hard coat layer may contain additives to further improve its strength. The additives are not limited, and examples include inorganic fine particles, organic fine particles, and mixtures thereof. The thickness of the hard coat layer is preferably thicker to provide hardness, but if it is too thick, it may be prone to cracking when cut, so it may be 1 μm to 20 μm, or 2 μm to 10 μm. The thickness of the hard coat layer is preferably 3 μm to 7 μm.

[0047] The antiglare layer is a layer having a finely uneven surface, and is preferably formed using the above-mentioned hard coat material.

[0048] An antiglare layer having a finely textured surface can be formed by the following methods: 1) forming a coating film containing fine particles on a stretched film and creating texture based on the fine particles; 2) forming a coating film, which may or may not contain fine particles, on a stretched film, and then pressing the film against a mold (such as a roll) that has been given a textured surface to transfer the textured pattern (also known as an embossing method).

[0049] The anti-reflection layer is a layer that reduces the external light reflection on the surface of a thermoplastic resin film for those observing the film, and typically has a reflectance of 1.5% or less for visible light. An anti-reflection layer with such a reflectance is typically formed by laminating a high-refractive index layer with a high refractive index and a low-refractive index layer with a low refractive index, or by using the method and materials described in JP 2021-6929 A. Adjusting the refractive index and thickness of each layer allows the reflected light from each layer to weaken each other, providing excellent anti-reflection functionality.

[0050] As will be described in detail later, an antireflection layer consisting of a high refractive index layer and a low refractive index layer is preferably produced using a coating composition capable of forming each of the high refractive index layer and the low refractive index layer, as this simplifies the process. Here, an example of a coating composition capable of forming each of the high refractive index layer and the low refractive index layer will be given. Such a coating composition is liquid and contains an appropriate curable resin and, if necessary, additives. A coating composition capable of forming a high refractive index layer (a composition for forming a high refractive index layer) is prepared by dissolving, for example, a curable resin such as urethane acrylate and a photopolymerization initiator (photopolymerization initiator) such as an acetophenone-based, benzophenone-based, benzyl dimethyl ketal-based, α-hydroxyalkylphenone-based, α-aminoalkylphenone-based, or thioxanthone-based compound in a solvent such as methyl ethyl ketone or methyl isobutyl ketone. To improve coatability, a leveling agent, preferably a fluorine-based leveling agent, may be added. Furthermore, coating compositions capable of forming low refractive index layers (compositions for forming low refractive index layers) include those prepared by dispersing silica particles in a solution prepared by dissolving a curable resin binder resin such as polyethylene glycol diacrylate or pentaerythritol (tri / tetra)acrylate in a solvent such as 1-methoxy-2-propyl acetate or methyl isobutyl ether, and a photopolymerization initiator (photopolymerization initiator) such as acetophenone, benzophenone, benzyl dimethyl ketal, α-hydroxyalkylphenone, α-aminoalkylphenone, or thioxanthone. A fluorine-based leveling agent may also be added to improve coating properties. The coating compositions for forming high and low refractive index layers listed here are merely examples, and it is preferable to optimize the high and low refractive index layer-forming compositions, respectively, depending on the properties of the antireflection layer to be formed.

[0051] The antireflection layer may include, for example, a low refractive index layer, or may have a multilayer structure further including a high refractive index layer and / or a medium refractive index layer between the thermoplastic resin film and the low refractive index layer.

[0052] The low refractive index layer can be formed by applying a coating solution containing a cured product of the above-mentioned curable resin or a light-transmitting resin such as a metal alkoxide polymer, and inorganic particles, and then curing the coating layer as needed. Examples of inorganic particles include low refractive index particles such as LiF (refractive index 1.4), MgF (refractive index 1.4), 3NaF·AlF (refractive index 1.4), AlF (refractive index 1.4), and Na3AlF6 (refractive index 1.33), as well as hollow silica particles.

[0053] The antistatic layer is provided for the purpose of imparting conductivity to the surface of a thermoplastic resin film and suppressing the effects of static electricity. For example, a method of applying a resin composition containing a conductive substance (antistatic agent) onto a thermoplastic resin film can be used to form the antistatic layer. For example, an antistatic hard coat layer can be formed by adding an antistatic agent to the hard coat material used to form the hard coat layer.

[0054] The antifouling layer is provided to impart water repellency, oil repellency, sweat resistance, antifouling properties, etc. A suitable material for forming the antifouling layer is a fluorine-containing organic compound. Examples of the fluorine-containing organic compound include fluorocarbon, perfluorosilane, and polymeric compounds thereof. Depending on the material to be formed, the antifouling layer can be formed by physical vapor deposition, typically vapor deposition or sputtering, chemical vapor deposition, wet coating, or the like. The average thickness of the antifouling layer is usually about 1 to 50 nm, preferably 3 to 35 nm.

[0055] When the protective layer is a resin layer such as a thermoplastic resin layer or a cured resin layer described later, the linear polarizer and the protective layer may be in direct contact with each other without an adhesive layer therebetween.

[0056] For example, a thermoplastic resin layer with a supporting substrate can be formed by applying a composition containing a thermoplastic resin to a supporting substrate and drying it as needed. The resulting thermoplastic resin layer is then attached to a linear polarizer via a pressure-sensitive adhesive layer, if necessary. The supporting substrate can then be peeled off and removed, thereby laminating a thermoplastic resin layer as a protective layer on the linear polarizer (first method). For example, when the protective layer is a thermoplastic resin layer, the composition can be applied directly to the surface of the linear polarizer and dried as needed to form the thermoplastic resin layer. In this case, the linear polarizer and the protective layer are in direct contact with each other without an adhesive layer (second method). However, when the composition contains a solvent, the first method is preferred because it is easier to stably form a thermoplastic resin layer with a sufficiently reduced solvent content.

[0057] The protective layer may be a cured resin layer containing a cured product of a curable resin. Examples of curable resins include thermosetting resins and active energy curable resins, such as (meth)acrylic resins, epoxy resins, oxetane resins, urethane resins, (meth)acrylic urethane resins, and melamine resins. The cured resin layer containing a cured product of a curable resin can be formed by applying a composition containing the curable resin to a support substrate, drying it as needed, and then applying heat or irradiating it with active energy rays such as visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, γ-rays, or electron beams. The resulting cured resin layer with the support substrate is attached to a linear polarizer, if necessary via a pressure-sensitive adhesive layer, and then the support substrate is peeled off and removed, thereby laminating the cured resin layer as a protective layer on the linear polarizer.

[0058] (First lamination layer 150) The first bonding layer 150 bonds the second protective layer 190 to the first liquid crystal retardation layer 30 side of the retardation layer laminate 300. It is preferable that the first bonding layer 150 be in direct contact with the first liquid crystal retardation layer 30. The first attaching layer 150 may be a pressure-sensitive adhesive layer (also called a pressure-sensitive adhesive) or an adhesive layer. It is preferable that the first attaching layer 150 is a pressure-sensitive adhesive layer from the viewpoint of suppressing unevenness in the optical laminate.

[0059] (Adhesive layer) As the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer, any conventionally known pressure-sensitive adhesive composition having excellent optical transparency can be used without particular limitation, and for example, a pressure-sensitive adhesive composition having a base polymer such as an acrylic resin, a urethane resin, a silicone resin, or a polyvinyl ether resin can be used. Alternatively, an active energy ray-curable pressure-sensitive adhesive composition or a heat-curable pressure-sensitive adhesive composition may be used. Among these, a pressure-sensitive adhesive composition having an acrylic resin as a base polymer, which is excellent in transparency, adhesive strength, removability, weather resistance, heat resistance, etc., is preferred.

[0060] The pressure-sensitive adhesive composition may further contain a crosslinking agent, a silane compound, an antistatic agent, and the like.

[0061] [(Meth)acrylic resin] The (meth)acrylic resin contained in the pressure-sensitive adhesive composition is preferably a polymer (hereinafter also referred to as a "(meth)acrylic acid ester polymer") having as its main component (for example, containing 50 parts by mass or more of the structural unit (I) derived from a (meth)acrylic acid alkyl ester represented by the following formula (I) (hereinafter also referred to as a "structural unit (I)"), per 100 parts by mass of the structural unit of the (meth)acrylic resin:

[0062] In this specification, the term "(meth)acrylic resin" means either an acrylic resin or a methacrylic resin, and the "(meth)" in (meth)acrylate has the same meaning. [ka] [In the formula, R 10 represents a hydrogen atom or a methyl group, and R 20 represents an alkyl group having 1 to 20 carbon atoms, and the alkyl group may have any of a linear, branched, or cyclic structure, and a hydrogen atom of the alkyl group may be substituted with an alkoxy group having 1 to 10 carbon atoms.

[0063] Examples of the (meth)acrylic acid ester represented by formula (I) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, i-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n- Examples of the alkyl acrylate containing an alkoxy group include 2-methoxyethyl (meth)acrylate and ethoxymethyl (meth)acrylate. Examples of the alkyl acrylate containing an alkoxy group include 2-methoxyethyl (meth)acrylate and ethoxymethyl (meth)acrylate. Examples of the alkyl acrylate containing an alkoxy group include 2-ethylhexyl (meth)acrylate and 2-ethylhexyl ...

[0064] The (meth)acrylic acid ester polymer may contain a structural unit derived from a monomer other than the structural unit (I). The structural unit derived from the other monomer may be one type or two or more types. Examples of the other monomer that the (meth)acrylic acid ester polymer may contain include a monomer having a polar functional group, a monomer having an aromatic group, and an acrylamide-based monomer.

[0065] Examples of the monomer having a polar functional group include (meth)acrylates having a polar functional group, such as a hydroxy group, a carboxy group, an amino group substituted with an alkyl group having 1 to 6 carbon atoms or an unsubstituted amino group, and a heterocyclic group such as an epoxy group.

[0066] The content of structural units derived from monomers having polar functional groups in the (meth)acrylic acid ester polymer is preferably 10 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less, even more preferably 0.5 parts by mass or more and 5 parts by mass or less, and particularly preferably 1 part by mass or more and 5 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylic acid ester polymer.

[0067] Examples of the monomer having an aromatic group include (meth)acrylic acid esters having one (meth)acryloyl group and one or more aromatic rings (e.g., benzene ring, naphthalene ring, etc.) in the molecule, and having a phenyl group, phenoxyethyl group, or benzyl group. By including these structural units, it is possible to suppress the white spots that occur in polarizing plates in high-temperature, high-humidity environments.

[0068] The content of structural units derived from monomers having an aromatic group in the (meth)acrylic acid ester polymer is preferably 20 parts by mass or less, more preferably 4 parts by mass or more and 20 parts by mass or less, and even more preferably 4 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylic acid ester polymer.

[0069] Examples of acrylamide monomers include N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, N-(2-methylpropoxymethyl)acrylamide, etc. By including these structural units, it is possible to suppress the bleeding out of additives such as antistatic agents, which will be described later.

[0070] Furthermore, structural units derived from monomers other than the structural unit (I) may include structural units derived from styrene-based monomers, structural units derived from vinyl-based monomers, structural units derived from monomers having multiple (meth)acryloyl groups in the molecule, and the like.

[0071] The weight-average molecular weight (hereinafter also simply referred to as "Mw") of the (meth)acrylic resin (1) is preferably 500,000 to 2,500,000. A weight-average molecular weight of 500,000 or more can improve the durability of the pressure-sensitive adhesive layer in high-temperature, high-humidity environments. A weight-average molecular weight of 2,500,000 or less improves operability when applying a coating liquid containing the pressure-sensitive adhesive composition. The molecular weight distribution (Mw / Mn), expressed as the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (hereinafter also simply referred to as "Mn"), is usually 2 to 10. In this specification, the "weight-average molecular weight" and "number-average molecular weight" are polystyrene-equivalent values ​​measured by gel permeation chromatography (GPC).

[0072] When the (meth)acrylic resin is dissolved in ethyl acetate to form a 20% by mass solution, the viscosity at 25°C is preferably 20 Pa·s or less, and more preferably 0.1 to 15 Pa·s. When the viscosity of the (meth)acrylic resin at 25°C is within this range, it contributes to improved durability and reworkability of a polarizing plate including a pressure-sensitive adhesive layer formed from the resin. The viscosity can be measured using a Brookfield viscometer.

[0073] The glass transition temperature (Tg) of the (meth)acrylic resin is, for example, −60 to 20° C., preferably −50 to 15° C., more preferably −45 to 10° C., and still more preferably −40 to 0° C. The glass transition temperature can be measured by a differential scanning calorimeter (DSC).

[0074] The (meth)acrylic resin may contain two or more types of (meth)acrylic acid ester polymers. Examples of such (meth)acrylic acid ester polymers include (meth)acrylic acid ester polymers having a relatively low molecular weight, such as those containing the structural unit (I) derived from the (meth)acrylic acid ester as the main component, and having a weight-average molecular weight in the range of 50,000 to 300,000.

[0075] (Meth)acrylic resins can usually be produced by known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. In producing (meth)acrylic resins, polymerization is usually carried out in the presence of a polymerization initiator. The amount of polymerization initiator used is usually 0.001 to 5 parts by mass per 100 parts by mass of the total of all monomers constituting the (meth)acrylic resin. (Meth)acrylic resins can also be produced by a method of polymerization using active energy rays such as ultraviolet rays.

[0076] [Crosslinking agent] The pressure-sensitive adhesive composition preferably contains a crosslinking agent, such as a conventional crosslinking agent (e.g., an isocyanate compound, an epoxy compound, an aziridine compound, a metal chelate compound, a peroxide, etc.), and is preferably an isocyanate compound from the viewpoints of the pot life of the pressure-sensitive adhesive composition, the crosslinking rate, and the durability of the polarizing plate.

[0077] The isocyanate compound is a compound having at least two isocyanato groups (-NCO) in the molecule. Specific examples include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, and triphenylmethane triisocyanate. Other examples include adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, as well as dimers and trimers of these isocyanate compounds. Two or more isocyanate compounds may be combined.

[0078] The proportion of the crosslinking agent relative to 100 parts by mass of the (meth)acrylic resin is, for example, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 1 part by mass.

[0079] [Silane compounds] The pressure-sensitive adhesive composition may further contain a silane compound.

[0080] Examples of the silane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

[0081] The silane compound may also contain an oligomer derived from the above silane compound.

[0082] The content of the silane compound in the pressure-sensitive adhesive composition is usually 0.01 to 10 parts by mass, and preferably 0.05 to 5 parts by mass, per 100 parts by mass of the (meth)acrylic resin. When the content of the silane compound is 0.01 part by mass or more, the adhesion between the pressure-sensitive adhesive layer and the adherend tends to be improved, and when the content is 10 parts by mass or less, bleeding out of the silane compound from the pressure-sensitive adhesive layer tends to be suppressed. As the silane compound, a silane coupling agent is preferred, and known silane coupling agents can be used.

[0083] <Antistatic agent> The pressure-sensitive adhesive composition may further contain an antistatic agent. Examples of the antistatic agent include known agents, with ionic antistatic agents being preferred. Examples of the cationic component constituting the ionic antistatic agent include organic cations and inorganic cations. Examples of organic cations include pyridinium cation, imidazolium cation, ammonium cation, sulfonium cation, and phosphonium cation. Examples of inorganic cations include alkali metal cations such as lithium cation, potassium cation, sodium cation, and cesium cation, and alkaline earth metal cations such as magnesium cation and calcium cation. Examples of the anionic component constituting the ionic antistatic agent include either inorganic or organic anions, but an anionic component containing a fluorine atom is preferred because of its excellent antistatic properties. Examples of the anionic component containing a fluorine atom include hexafluorophosphate anion (PF6 - ), bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N - ], bis(fluorosulfonyl)imide anion [(FSO2)2N - ] anions and the like.

[0084] Ionic antistatic agents that are solid at room temperature are preferred in that they provide excellent stability over time of the antistatic performance of the pressure-sensitive adhesive composition.

[0085] The content of the antistatic agent is, for example, 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, and more preferably 1 to 7 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin.

[0086] The pressure-sensitive adhesive composition may contain one or more additives such as an ultraviolet absorber, a solvent, a crosslinking catalyst, a tackifier, a plasticizer, etc. It is also useful to blend an ultraviolet-curable compound into the pressure-sensitive adhesive composition, form a pressure-sensitive adhesive layer, and then cure it by irradiating it with ultraviolet light to form a harder pressure-sensitive adhesive layer.

[0087] The pressure-sensitive adhesive layer can be formed, for example, by dissolving or dispersing the pressure-sensitive adhesive composition in a solvent to prepare a solvent-containing pressure-sensitive adhesive composition, which is then applied to the surface of the layer on which the pressure-sensitive adhesive layer is to be formed, and drying.

[0088] The thickness of the pressure-sensitive adhesive layer is usually 0.1 to 30 μm, preferably 0.5 to 20 μm, and more preferably 1 to 15 μm.

[0089] (adhesive layer) The adhesive layer may be formed from an adhesive composition.

[0090] Examples of adhesive compositions include aqueous adhesive compositions and curable adhesive compositions that cure upon heating or irradiation with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays. Examples of aqueous adhesive compositions include those in which a polyvinyl alcohol resin or a urethane resin is dissolved in water as the main component, and those in which a polyvinyl alcohol resin or a urethane resin is dispersed in water as the main component. The aqueous adhesive composition may further contain a curable component or crosslinking agent such as a polyaldehyde, a melamine compound, a zirconia compound, a zinc compound, a glyoxal compound, or a water-soluble epoxy resin. Examples of aqueous adhesive compositions include the adhesive composition described in JP 2010-191389 A, the adhesive composition described in JP 2011-107686 A, the composition described in JP 2020-172088 A, and the composition described in JP 2005-208456 A.

[0091] The curable adhesive composition is preferably an active energy ray-curable adhesive composition that contains a curable (polymerizable) compound as a main component and is cured by irradiation with active energy rays. Examples of active energy ray-curable adhesive compositions include cationic polymerization adhesive compositions that contain a cationic polymerizable compound as the curable compound, radical polymerization adhesive compositions that contain a radical polymerizable compound as the curable compound, and hybrid adhesive compositions that contain both a cationic polymerizable compound and a radical polymerizable compound as the curable compound.

[0092] The cationically polymerizable compound is a compound or oligomer that undergoes a cationic polymerization reaction and hardens when exposed to active energy rays such as ultraviolet light, visible light, electron beams, or X-rays or when heated. Specific examples of the cationically polymerizable compound include epoxy compounds, oxetane compounds, and vinyl compounds.

[0093] Examples of epoxy compounds include alicyclic epoxy compounds (compounds having one or more epoxy groups bonded to an alicyclic ring in the molecule) such as 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate; aromatic epoxy compounds (compounds having an aromatic ring and an epoxy group in the molecule) such as diglycidyl ether of bisphenol A; and aliphatic epoxy compounds (compounds having at least one oxirane ring bonded to an aliphatic carbon atom in the molecule) such as 2-ethylhexyl glycidyl ether and 1,4-butanediol diglycidyl ether.

[0094] Examples of the oxetane compound include compounds having one or more oxetane rings in the molecule, such as 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane.

[0095] The cationic polymerization adhesive composition preferably contains a cationic polymerization initiator. The cationic polymerization initiator may be a thermal cationic polymerization initiator or a photo-induced cationic polymerization initiator. Examples of the cationic polymerization initiator include aromatic diazonium salts such as benzenediazonium hexafluoroantimonate; aromatic iodonium salts such as diphenyliodonium tetrakis(pentafluorophenyl)borate; aromatic sulfonium salts such as triphenylsulfonium hexafluorophosphate; and iron-arene complexes such as xylene-cyclopentadienyl iron(II) hexafluoroantimonate. The content of the cationic polymerization initiator is usually 0.1 to 10 parts by mass per 100 parts by mass of the cationic polymerizable compound. Two or more types of cationic polymerization initiators may be used.

[0096] Examples of cationic polymerization adhesive compositions include the cationic polymerization compositions described in JP 2016-126345 A, WO 2019 / 10315 A, and JP 2021-113969 A.

[0097] The radical polymerizable compound is a compound or oligomer that undergoes a radical polymerization reaction and hardens when exposed to active energy rays such as ultraviolet light, visible light, electron beams, or X-rays or when heated, and specific examples thereof include compounds having an ethylenically unsaturated bond. Examples of the compound having an ethylenically unsaturated bond include (meth)acrylic compounds having one or more (meth)acryloyl groups in the molecule and vinyl compounds having one or more vinyl groups in the molecule.

[0098] Examples of the (meth)acrylic compound include (meth)acrylate monomers and (meth)acrylamide monomers each having at least one (meth)acryloyloxy group in the molecule, and (meth)acryl group-containing compounds such as (meth)acrylic oligomers obtained by reacting two or more functional group-containing compounds and each having at least two (meth)acryloyl groups in the molecule. In this specification, (meth)acryloyl means either acryloyl or methacryloyl.

[0099] The radical polymerization adhesive composition preferably contains a radical polymerization initiator. The radical polymerization initiator may be a thermal radical polymerization initiator or a photoradical polymerization initiator. Examples of the radical polymerization initiator include acetophenone-based initiators such as acetophenone and 3-methylacetophenone; benzophenone-based initiators such as benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone; benzoin ether-based initiators such as benzoin propyl ether and benzoin ethyl ether; thioxanthone-based initiators such as 4-isopropylthioxanthone; xanthone, fluorenone, etc. The content of the radical polymerization initiator is usually 0.1 to 10 parts by mass per 100 parts by mass of the radical polymerizable compound. Two or more types of radical polymerization initiators may be used.

[0100] Examples of radical polymerization adhesive compositions include the radical polymerizable compositions described in JP 2016-126345 A, JP 2016-153474 A, and WO 2017 / 183335 A.

[0101] The active energy ray-curable adhesive composition may contain additives such as an ion trapping agent, an antioxidant, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow adjuster, a plasticizer, an antifoaming agent, an antistatic agent, a leveling agent, and a solvent, as needed.

[0102] The adhesive composition and adhesive layer may contain a silicone-based or fluorine-based leveling agent as described in the section on the liquid crystal retardation layer. The content of the leveling agent in the adhesive composition and adhesive layer is preferably 0.001 to 2 parts by mass, more preferably 0.01 to 1.5 parts by mass, and even more preferably 0.1 to 1.5 parts by mass, per 100 parts by mass of the solid content.

[0103] The bonding of the first liquid crystal retardation layer and the second liquid crystal retardation layer with an adhesive layer can be performed by applying an adhesive composition to at least one bonding surface selected from the bonding surface of the first liquid crystal retardation layer and the bonding surface of the second liquid crystal retardation layer, stacking the two layers with the coating layer of the adhesive composition interposed therebetween, pressing them together from above and below using a laminating roll or the like, and then drying the adhesive layer, curing it by irradiating it with active energy rays, or curing it by heating.

[0104] Before forming the coating layer of the adhesive layer, at least one of the bonding surfaces selected from the bonding surface of the first liquid crystal retardation layer and the bonding surface of the second liquid crystal retardation layer may be subjected to an easy-adhesion treatment such as a saponification treatment, a corona treatment, a plasma treatment, a primer treatment, or an anchor coating treatment.

[0105] To form a coating layer of the adhesive composition, various coating methods can be used, such as a die coater, a comma coater, a gravure coater, a wire bar coater, or a doctor blade coater.

[0106] The light irradiation intensity when irradiating with active energy rays is determined depending on the composition of the active energy ray-curable adhesive composition and is not particularly limited, but is preferably 10 mW / cm 2 More than 1,000mW / cm 2 The irradiation intensity is preferably an intensity in a wavelength region effective for activating a photocationic polymerization initiator or a photoradical polymerization initiator. Irradiation is performed once or multiple times at such a light irradiation intensity, and the cumulative light amount is 10 mJ / cm or less. 2 It is preferable to set the dose to 100 mJ / cm or more. 2 More than 1,000mJ / cm 2 It is more preferable to set the following:

[0107] The light source used to polymerize and cure the active energy ray-curable adhesive composition is not particularly limited, but examples include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps.

[0108] The thickness of the adhesive layer formed from the aqueous adhesive composition may be, for example, 5 μm or less, preferably 1 μm or less, and more preferably 0.5 μm or less, and may be 0.01 μm or more, and preferably 0.03 μm or more.

[0109] The thickness of the adhesive layer formed from the active energy ray-curable adhesive composition may be, for example, 10 μm or less, preferably 5 μm or less, and more preferably 3 μm or less, or may be 0.1 μm or more, preferably 0.3 μm or more, and more preferably 0.5 μm or more.

[0110] (Difference in in-plane refractive index between the second protective layer and the first bonding layer) In one embodiment of the present invention, the difference (absolute value difference: |n1-n2|) between the in-plane average refractive index of the second protective layer (hereinafter also referred to as "refractive index n1") and the in-plane average refractive index of the first attaching layer (hereinafter also referred to as "refractive index n2") is preferably 0.10 or less, more preferably 0.05 or less, and even more preferably 0.03 or less. When the difference between the refractive index n1 of the second protective layer and the refractive index n2 of the first attaching layer is equal to or less than the above-mentioned upper limit, the effect of suppressing light reflection at the interface between these two layers can be further expected, thereby having the effect of further suppressing unevenness in the optical laminate. From the viewpoint of suppressing light reflection and obtaining excellent reflection suppression effect when incorporated into a display device, the smaller the difference, the better, and ideally it is 0.

[0111] (Arithmetic mean roughness of the surface of the first bonding layer on the side of the retardation layer laminate 300) The arithmetic mean roughness Ra of the first bonding layer 150 on the side of the retardation layer laminate 300 is preferably 35 nm or less. The arithmetic mean roughness Ra is preferably 30 nm or less, more preferably 25 nm or less, and even more preferably 20 nm or less. This has the effect of further suppressing unevenness in the optical laminate.

[0112] (Retardation layer laminate 300) The retardation layer laminate 300 has, in order from the linear polarizer 220 side, a first liquid crystal retardation layer 30, a second bonding layer 40, and a second liquid crystal retardation layer 50.

[0113] (First liquid crystal retardation layer 30 and second liquid crystal retardation layer 50)

[0114] The liquid crystal retardation layer is a cured layer of an aligned polymerizable liquid crystal compound, and exhibits retardation.

[0115] The liquid crystal retardation layer is not limited as long as it is a layer that exhibits retardation in any direction, and may be a retardation layer that generates an in-plane retardation such as a positive A plate or a negative A plate, or may be a retardation layer that generates a retardation in the thickness direction such as a positive C plate or a negative C plate. The positive A plate and the negative A plate may each be a λ / 4 plate or a λ / 2 plate. The liquid crystal retardation layer may be tilted or may form a cholesteric alignment state.

[0116] The first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 may each independently be a single liquid crystal retardation layer or a laminate of a plurality of liquid crystal retardation layers. It is preferable that the angle θ formed by the slow axis of the first liquid crystal retardation layer 30 and the transmission axis of the linear polarizer 220 is 10° to 20° or −10° to −20°. This has the effect of effectively suppressing reflection of external light by the metal electrodes when the optical laminate is used in an OLED display device.

[0117] Each liquid crystal retardation layer may have a normal wavelength dispersion property or a reverse wavelength dispersion property.

[0118] When the in-plane retardation value of the retardation layer laminate 300 for light with a wavelength of λ nm measured in the optical laminate 400 is Re(λ), it is preferable that the retardation layer laminate 300 satisfies the relationships of the following formulas (1) and (2). 70nm≦Re(450)≦150nm (1) Re(450) / Re(550)≦1.00 (2) [In formula (1) and formula (2), Re(450) represents the in-plane retardation value nm of the retardation layer laminate 300 for light with a wavelength of 450 nm, Re(550) represents the in-plane retardation value nm of the retardation layer laminate 300 for light with a wavelength of 550 nm.] The in-plane retardation value can be measured in the state of the optical laminate 400 including a linear polarizer using an in-plane retardation measurement device such as KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. If the first protective layer 180 or the second protective layer 190 included in the optical laminate 400 has a retardation, the retardation value must be canceled and the value of the optical laminate 400 must be measured, and this must be used as the in-plane retardation value of the retardation layer laminate 300.

[0119] The liquid crystal retardation layer is usually formed by applying a liquid crystal retardation layer-forming composition containing a polymerizable liquid crystal compound onto an alignment film formed on a substrate, and polymerizing and curing the polymerizable liquid crystal compound in an aligned state.

[0120] The thickness of the liquid crystal retardation layer is usually 10 μm or less, preferably 5 μm or less, and more preferably 0.3 μm or more and 3 μm or less.

[0121] In order to achieve a high level of anti-reflection function, the liquid crystal retardation layer preferably has a λ / 4 plate function (i.e., a π / 2 retardation function) over the entire visible light range. Specifically, a reverse wavelength dispersion λ / 4 layer is preferred, or a combination of two or more retardation films with different orientations is preferred. For example, a combination of a retardation film having a λ / 2 plate function (i.e., a π retardation function) and a retardation film having a λ / 4 plate function (i.e., a π / 2 retardation function) may be used.

[0122] Furthermore, from the viewpoint of compensating for the anti-reflection function in oblique directions, it is preferable to include a layer having anisotropy in the thickness direction (positive C plate). In addition, each liquid crystal retardation layer may have an optically anisotropic layer with tilt alignment or may form a cholesteric alignment state.

[0123] (Combination of First Liquid Crystal Retardation Layer and Second Liquid Crystal Retardation Layer) The first and second liquid crystal retardation layers may be the same liquid crystal retardation layer, or may be a combination of different types.

[0124] For example, one of the first and second liquid crystal retardation layers may be a reverse wavelength dispersion λ / 4 plate, and the other of the first and second liquid crystal retardation layers may be a positive C plate.

[0125] Alternatively, one of the first liquid crystal retardation layer and the second liquid crystal retardation layer may be a positive wavelength dispersion λ / 2 plate, and the other of the first liquid crystal retardation layer and the second liquid crystal retardation layer may be a positive wavelength dispersion λ / 4 plate.

[0126] Hereinafter, as an example of the liquid crystal retardation layer, a stack of a reverse wavelength dispersion λ / 4 plate, a positive wavelength dispersion λ / 4 plate and a positive wavelength dispersion λ / 2 plate, and a positive C plate will be described.

[0127] (Reverse wavelength dispersion λ / 4 plate (R)) The reverse wavelength dispersion λ / 4 plate preferably satisfies the optical properties represented by the following formulas (R1) and (R2), where Re(λ) is the in-plane retardation for light with a wavelength of λ nm over the entire visible light range, and more preferably satisfies the optical properties represented by the following formulas (R1), (R2), and (R3):

[0128] 100nm <Re(550)<160nm …(R1) (In the formula, Re(550) represents the in-plane phase difference value (in-plane retardation) for light with a wavelength of 550 nm.) Re(450) / Re(550)≦1.0 …(R2) 1.00≦Re(650) / Re(550) …(R3) (In the formula, Re(450) represents the in-plane retardation value (unit: nm) for light with a wavelength of 450 nm, Re(550) represents the in-plane retardation value (unit: nm) for light with a wavelength of 550 nm, and Re(650) represents the in-plane retardation value (unit: nm) for light with a wavelength of 650 nm.) When the "Re(450) / Re(550)" of the liquid crystal retardation layer exceeds 1.0, the light leakage on the short wavelength side of an elliptical polarizer including the liquid crystal retardation layer increases, and is preferably 0.7 or more and 1.0 or less, more preferably 0.80 or more and 0.95 or less, even more preferably 0.80 or more and 0.92 or less, and particularly preferably 0.82 or more and 0.88 or less.

[0129] The value of "Re(450) / Re(550)" can be adjusted arbitrarily by adjusting the mixing ratio of the polymerizable liquid crystal compound, the lamination angle of the plurality of optically anisotropic layers, and the retardation value.

[0130] The in-plane retardation value of the retardation film can be adjusted by the thickness of the retardation film. Since the in-plane retardation value is determined by the following formula (4), a desired in-plane retardation value (Re(λ)) can be obtained by adjusting Δn(λ) and the film thickness d. The thickness of the retardation film is preferably 0.5 μm to 5 μm, more preferably 1 μm to 3 μm. The thickness of the retardation film can be measured using an interference film thickness meter, a laser microscope, or a stylus film thickness meter. Δn(λ) depends on the molecular structure of the polymerizable liquid crystal compound, which will be described later.

[0131] Re(λ)=d×Δn(λ) …(4) (In the formula, Re(λ) represents the in-plane retardation value (nm) at a wavelength of λ nm, d represents the film thickness, and Δn(λ) represents the birefringence at a wavelength of λ nm.)

[0132] The liquid crystal retardation layer is usually formed by applying a liquid crystal retardation layer-forming composition onto an alignment film formed on a substrate, and polymerizing the polymerizable liquid crystal compound contained in the liquid crystal retardation layer composition in an aligned state. In addition, the retardation film-forming composition may further contain a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesion improver, etc.

[0133] <Polymerizable liquid crystal compound for forming a reverse wavelength dispersion λ / 4 plate> A polymerizable liquid crystal compound refers to a liquid crystal compound having a polymerizable group, particularly a photopolymerizable group. Conventional polymerizable liquid crystal compounds can be used as the polymerizable liquid crystal compound for forming a reverse wavelength dispersion λ / 4 plate. The photopolymerizable group refers to a group that can participate in a polymerization reaction by reactive species, such as active radicals or acids, generated from a photopolymerization initiator. Examples of photopolymerizable groups include vinyl groups, vinyloxy groups, 1-chlorovinyl groups, isopropenyl groups, 4-vinylphenyl groups, acryloyloxy groups, methacryloyloxy groups, oxiranyl groups, and oxetanyl groups. Among these, acryloyloxy groups, methacryloyloxy groups, vinyloxy groups, oxiranyl groups, and oxetanyl groups are preferred, with acryloyloxy groups being more preferred. The liquid crystal property may be either thermotropic or lyotropic, but thermotropic liquid crystals are preferred due to their ability to precisely control the film thickness. Furthermore, the phase order structure of the thermotropic liquid crystal may be either nematic or smectic. The polymerizable liquid crystal compounds may be rod-shaped or discotic. They may be used alone or in combination of two or more.

[0134] As the polymerizable liquid crystal compound, from the viewpoint of exhibiting reverse wavelength dispersion, a liquid crystal having a T-shaped or H-shaped mesogen structure which further has birefringence in the direction perpendicular to the molecular long axis direction is preferred, and from the viewpoint of obtaining stronger dispersion, a T-shaped liquid crystal is more preferred. Specific examples of the structure of the T-shaped liquid crystal include those represented by the following formula (I):

[0135] [ka] Examples of the compound include compounds represented by the following formula:

[0136] In formula (I), Ar represents a divalent aromatic group which may have a substituent. The divalent aromatic group preferably contains at least one of a nitrogen atom, an oxygen atom, and a sulfur atom. When the divalent group Ar contains two or more aromatic groups, the two or more aromatic groups may be bonded to each other via a divalent bonding group such as a single bond, -CO-O-, or -O-.

[0137] G 1 and G 2 each independently represents a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein a hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group, and a carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom.

[0138] L 1 , L 2 、 B 1 and B 2 are each independently a single bond or a divalent linking group.

[0139] k and l each independently represent an integer of 0 to 3, and satisfy the relationship 1≦k+l. When 2≦k+l, B 1 and B 2 , G 1 and G 2 may be the same as or different from each other.

[0140] E 1 and E 2 each independently represents an alkanediyl group having 1 to 17 carbon atoms, wherein a hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and wherein a -CH2- contained in the alkanediyl group may be substituted with -O-, -S-, or -COO-, and when there are a plurality of -O-, -S-, or -COO-, they are not adjacent to each other. 1 and P 2 each independently represents a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.

[0141] G 1 and G 2are each independently preferably a 1,4-phenylenediyl group optionally substituted with at least one substituent selected from the group consisting of halogen atoms and alkyl groups having 1 to 4 carbon atoms, or a 1,4-cyclohexanediyl group optionally substituted with at least one substituent selected from the group consisting of halogen atoms and alkyl groups having 1 to 4 carbon atoms, more preferably a 1,4-phenylenediyl group substituted with a methyl group, an unsubstituted 1,4-phenylenediyl group, or an unsubstituted 1,4-trans-cyclohexanediyl group, and particularly preferably an unsubstituted 1,4-phenylenediyl group or an unsubstituted 1,4-trans-cyclohexanediyl group.

[0142] Also, there are multiple G 1 and G 2 At least one of L is preferably a divalent alicyclic hydrocarbon group. 1 or L 2 G binds to 1 and G 2 It is more preferable that at least one of the groups is a divalent alicyclic hydrocarbon group.

[0143] L 1 and L 2 are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a1 OR a2 -, -R a3 COOR a4 -, -R a5 OCOR a6 -, R a7 OC=OOR a8 -, -N=N-, -CR c =CR d -, or C≡C-, where R a1 ~R a8 each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms; R c and R d represents an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. 1 and L 2 are each independently preferably a single bond, -OR a2-1-, -CH2-, -CH2CH2-, -COOR a4-1 - or OCOR a6-1 -, where R a2-1 , R a4-1 , R a6-1 Each independently represents a single bond, -CH2-, or -CH2CH2-. 1 and L 2 are each independently more preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, or OCO-.

[0144] B 1 and B 2 are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a9 OR a10 -, -R a11 COOR a12 -, -R a13 OCOR a14 - or R a15 OC=OOR a16 -, where R a9 ~R a16 each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms. 1 and B 2 are each independently preferably a single bond, -OR a10-1 -, -CH2-, -CH2CH2-, -COOR a12-1 - or OCOR a14-1 -, where R a10-1 , R a12-1 , R a14-1 Each independently represents a single bond, -CH2-, or -CH2CH2-. B 1 and B 2 are each independently more preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, -OCO-, or OCOCH2CH2-.

[0145] From the viewpoint of exhibiting reverse wavelength dispersion, k and l are preferably in the range of 2≦k+l≦6, preferably k+l=4, and more preferably k=2 and l=2. When k=2 and l=2, a symmetric structure is obtained, which is preferable.

[0146] E 1 and E 2 are each independently preferably an alkanediyl group having 1 to 17 carbon atoms, more preferably an alkanediyl group having 4 to 12 carbon atoms.

[0147] P 1 or P 2 Examples of the polymerizable group represented by the formula (I) include an epoxy group, a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. Among these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferred, and an acryloyloxy group is more preferred.

[0148] Ar preferably has at least one selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, and an electron-withdrawing group. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring, with a benzene ring and a naphthalene ring being preferred. Examples of the aromatic heterocyclic ring include a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazole ring, a triazine ring, a pyrroline ring, an imidazole ring, a pyrazole ring, a thiazole ring, a benzothiazole ring, a thienothiazole ring, an oxazole ring, a benzoxazole ring, and a phenanthroline ring. Among these, a thiazole ring, a benzothiazole ring, or a benzofuran ring is preferred, and a benzothiazole group is even more preferred. Furthermore, when Ar contains a nitrogen atom, it is preferred that the nitrogen atom has π electrons.

[0149] In formula (I), the total number of π electrons contained in the divalent aromatic group represented by Ar is N πis preferably 8 or more, more preferably 10 or more, even more preferably 14 or more, and particularly preferably 16 or more. It is also preferably 30 or less, more preferably 26 or less, and even more preferably 24 or less.

[0150] Suitable examples of the aromatic group represented by Ar include the following groups:

[0151] [ka]

[0152] In formulas (Ar-1) to (Ar-23), * represents a linking portion, and Z 0 , Z 1 and Z 2 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, an alkylsulfonyl group having 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, an N-alkylamino group having 1 to 12 carbon atoms, an N,N-dialkylamino group having 2 to 12 carbon atoms, an N-alkylsulfamoyl group having 1 to 12 carbon atoms, or an N,N-dialkylsulfamoyl group having 2 to 12 carbon atoms.

[0153] Q 1 , and Q 2 are each independently -CR 2’ R 3’ -, -S-, -NH-, -NR 2’ represents -, -CO- or O-; R 2’ and R 3’ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0154] J 1 , and J 2 each independently represents a carbon atom or a nitrogen atom.

[0155] Y 1 , and Y 2each independently represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group.

[0156] W 1 and W 2 each independently represents a hydrogen atom, a cyano group, a methyl group or a halogen atom; and m represents an integer of 0 to 6.

[0157] Y 1 , and Y 2 Examples of the aromatic hydrocarbon group in the formula (I) include aromatic hydrocarbon groups having 6 to 20 carbon atoms, such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, and a biphenyl group, with a phenyl group and a naphthyl group being preferred, and a phenyl group being more preferred. Examples of the aromatic heterocyclic group include aromatic heterocyclic groups having 4 to 20 carbon atoms and containing at least one heteroatom, such as a nitrogen atom, an oxygen atom, or a sulfur atom, such as a furyl group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group, and a benzothiazolyl group being preferred.

[0158] Y 1 , and Y 2 may each independently be an optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group. The polycyclic aromatic hydrocarbon group refers to a fused polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. The polycyclic aromatic heterocyclic group refers to a fused polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

[0159] Z 0 , Z 1 and Z 2 are each independently preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms; Z 0 is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, and Z 1 and Z 2 is more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.

[0160] Q1 , and Q 2 -NH-, -S-, -NR 2’ -, -O- are preferred, and R 2’ is preferably a hydrogen atom, and among these, -S-, -O-, and -NH- are particularly preferred.

[0161] Among the formulae (Ar-1) to (Ar-23), the formulae (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability.

[0162] In formulas (Ar-16) to (Ar-23), Y 1 is the nitrogen atom to which it is bonded and Z 0 and Y may form an aromatic heterocyclic group together. Examples of the aromatic heterocyclic group include those mentioned above as aromatic heterocycles that Ar may have, such as a pyrrole ring, an imidazole ring, a pyrroline ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, an indole ring, a quinoline ring, an isoquinoline ring, a purine ring, and a pyrrolidine ring. This aromatic heterocyclic group may have a substituent. In addition, Y 1 is the nitrogen atom to which it is bonded and Z 0 and may be the above-mentioned optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group, such as a benzofuran ring, a benzothiazole ring, or a benzoxazole ring.

[0163] Among polymerizable liquid crystal compounds, compounds with a maximum absorption wavelength of 300 to 400 nm are preferred. When a polymerizable liquid crystal composition contains a photopolymerization initiator, the polymerization reaction and gelation of the polymerizable liquid crystal compound may progress during long-term storage. However, if the polymerizable liquid crystal compound has a maximum absorption wavelength of 300 to 400 nm, even if the composition is exposed to ultraviolet light during storage, the generation of reactive species from the photopolymerization initiator and the progression of the polymerization reaction and gelation of the polymerizable liquid crystal compound due to the reactive species can be effectively suppressed. This is advantageous in terms of long-term stability of the polymerizable liquid crystal composition and can improve the alignment and film thickness uniformity of the resulting cured liquid crystal film. The maximum absorption wavelength of the polymerizable liquid crystal compound can be measured using a UV-visible spectrophotometer in a solvent. The solvent can be a solvent capable of dissolving the polymerizable liquid crystal compound, such as chloroform.

[0164] The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass, relative to 100 parts by mass of the solid content of the polymerizable liquid crystal composition. A content of the polymerizable liquid crystal compound within the above range is advantageous from the viewpoint of the alignment of the resulting cured liquid crystal film. In this specification, the solid content of the polymerizable liquid crystal composition refers to all components of the polymerizable liquid crystal composition excluding volatile components such as organic solvents.

[0165] [Laminate containing a positive wavelength dispersive λ / 2 plate and a positive wavelength dispersive λ / 4 plate] As a method for achieving antireflection performance, a laminate combining a positive wavelength dispersion λ / 2 plate and a positive wavelength dispersion λ / 4 plate is known. For example, one example of a laminate can be obtained by combining a layer having the optical properties represented by formulas (QL1), (QL3), and (QL4) with a layer having the optical properties represented by formulas (QL2), (QL3), and (QL4) in a specific slow axis relationship.

[0166] 100nm <Re(550)<160nm (QL1) 200nm <Re(550)<320nm (QL2) Re(450) / Re(550)≧1.00 (QL3) 1.00≧Re(650) / Re(550) (QL4)

[0167] Methods for combining the above-mentioned configurations include well-known methods such as those described in JP 2015-163935 A and WO 2013 / 137464 A. From the viewpoint of viewing angle compensation, it is preferable to use a λ / 2 layer containing a polymer of a discotic polymerizable liquid crystal compound and a λ / 4 layer containing a polymer of a rod-shaped polymerizable liquid crystal compound.

[0168] The slow axis of the positive wavelength dispersion λ / 2 layer is, for example, 10° to 20°, preferably 12° to 18°, and more preferably about 15°, relative to the transmission axis of the linear polarizer, and the slow axis of the positive wavelength dispersion λ / 4 layer is, for example, 70° or more and 80° or less, more preferably 72° or more and 78° or less, and more preferably about 75°. In another embodiment, the slow axis of the positive wavelength dispersion λ / 2 layer is, for example, at an angle of -10° to -20°, preferably -12° to -18°, and more preferably about -15°, relative to the transmission axis of the linear polarizer, and the slow axis of the positive wavelength dispersion λ / 4 layer is, for example, at an angle of -70° to -80°, more preferably -72° to -78°, and more preferably about -75°. In yet another embodiment, the slow axis of the positive wavelength dispersion λ / 2 layer is at an angle of 70° to 80°, preferably 72° to 78°, and more preferably about 75°, relative to the transmission axis of the linear polarizer, and the slow axis of the positive wavelength dispersion λ / 4 layer is at an angle of, for example, 10° to 20°, more preferably 12° to 18°, and more preferably about 15°. In yet another embodiment, the slow axis of the positive wavelength dispersion λ / 2 layer is at an angle of -70° to -80°, preferably -72° to -78°, and more preferably about -75°, relative to the transmission axis of the linear polarizer, and the slow axis of the positive wavelength dispersion λ / 4 layer is at an angle of, for example, -10° to -20°, more preferably -12° to -18°, and even more preferably about -15°.

[0169] Examples of the discotic polymerizable liquid crystal compound include a compound containing a group represented by formula (W) (hereinafter, sometimes referred to as polymerizable liquid crystal compound (C)). [ka] [In formula (W), R 40 represents the following formulas (W-1) to (W-5).

[0170] [ka]

[0171] X 40 and Z 40 represents an alkanediyl group having 1 to 12 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and a hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. Furthermore, -CH2- constituting the alkanediyl group may be replaced with -O- or -CO-. Furthermore, m2 is an integer of 1 to 20.

[0172] Examples of the rod-shaped polymerizable liquid crystal compound include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V) or formula (VI). P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III) P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV) P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V) P11-B11-E11-B12-A11-B13-A12-F11 (VI) A11 represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. A hydrogen atom contained in the divalent alicyclic hydrocarbon group or divalent aromatic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group, and a hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom.

[0173] B11 is -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR 16 -, -NR 16 R represents -CO-, -CO-, -CS- or a single bond. 16 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0174] B12 and B13 each independently represent -C≡C-, -CH=CH-, -CH2-CH2-, -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)-, -OC(=O)-O-, -CH=N-, -N=CH-, -N=N-, or -C(=O)-NR 16 -, -NR 16 represents -C(=O)-, -OCH2-, -OCF2-, -CHO-, -CF2O-, -CH=CH-C(=O)-O-, -OC(=O)-CH=CH- or a single bond.

[0175] E11 represents an alkanediyl group having 1 to 12 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and a hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. In addition, -CH2- constituting the alkanediyl group may be substituted with -O- or -CO-.

[0176] The number of carbon atoms in the aromatic hydrocarbon group and alicyclic hydrocarbon group of A11 is preferably in the range of 3 to 18, more preferably in the range of 5 to 12, and particularly preferably 5 or 6. A11 is preferably a cyclohexane-1,4-diyl group or a 1,4-phenylene group.

[0177] E11 is preferably a linear alkanediyl group having 1 to 12 carbon atoms. -CH2- constituting the alkanediyl group may be replaced with -O-.

[0178] Specific examples include linear alkanediyl groups having 1 to 12 carbon atoms, such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; -CH-CH-O-CH-CH-, -CH-CH-O-CH-CH-O-CH-CH-, and -CH-CH-O-CH-CH-O-CH-CH-O-CH-CH-.

[0179] As B11, -O-, -S-, -CO-O-, and -O-CO- are preferred, and among these, -CO-O- is more preferred.

[0180] B12 and B13 are each independently preferably -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)- or -OC(=O)-O-, and among these, -O- or -OC(=O)-O- is more preferred.

[0181] The polymerizable group represented by P11 is preferably a radically polymerizable group or a cationically polymerizable group in terms of high polymerization reactivity, particularly high photopolymerization reactivity. In addition, the polymerizable group is preferably a group represented by the following formulas (P-11) to (P-15), because they are easy to handle and the liquid crystal compound itself is easy to produce.

[0182] [ka] [In formulas (P-11) to (P-15), R 17 ~R 21 each independently represents an alkyl group having 1 to 6 carbon atoms or a hydrogen atom.

[0183] Specific examples of the groups represented by formulae (P-11) to (P-15) include groups represented by the following formulae (P-16) to (P-20).

[0184] [ka]

[0185] P11 is preferably a group represented by formula (P-14) to formula (P-20), and more preferably a vinyl group, a p-stilbene group, an epoxy group or an oxetanyl group.

[0186] The group represented by P11-B11- is more preferably an acryloyloxy group or a methacryloyloxy group.

[0187] (In the formula, A12 to A14 each independently have the same meaning as A11, B14 to B16 each independently have the same meaning as B12, B17 has the same meaning as B11, and E12 has the same meaning as E11. F11 represents a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group (—SOH), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and —CH 2 - may be replaced with -O-.

[0188] [Other configurations] The first and second liquid crystal retardation layers may be configured by combining the above-mentioned positive wavelength dispersion λ / 2 layer and positive wavelength dispersion λ / 4 layer, or may be a laminate in which at least one liquid crystal retardation layer has a tilt orientation or a cholesteric orientation, for example, well-known configurations such as those described in WO2021 / 060378, WO2021 / 132616, and WO2021 / 132624.

[0189] <Positive C Plate> There are no particular limitations on the positive C plate as long as it has anisotropy in the thickness direction, but if it does not have tilt alignment or cholesteric alignment, it has optical properties expressed by formula (PC3). nx≒ny <nz (PC3)

[0190] The in-plane retardation value Re(550) of the positive C plate at a wavelength of 550 nm is usually in the range of 0 to 10 nm, preferably 0 to 5 nm. Furthermore, the thickness direction retardation value Rth(550) at a wavelength of 550 nm is usually in the range of −170 nm to −10 nm, preferably −150 nm to −20 nm, and more preferably −100 nm to −40 nm. If the thickness direction retardation value falls within this range, the anti-reflection properties from oblique directions can be further improved.

[0191] The thickness of the positive C plate is usually 10 μm or less, preferably 5 μm or less, and more preferably 0.3 μm or more and 3 μm or less.

[0192] The positive C plate is preferably a coating layer formed by polymerizing one or more polymerizable liquid crystal compounds, more preferably rod-shaped polymerizable liquid crystal compounds.

[0193] Examples of the rod-shaped polymerizable liquid crystal include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V) or formula (VI). P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III) P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV) P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V) P11-B11-E11-B12-A11-B13-A12-F11 (VI) (In the formula, A12 to A14 each independently have the same meaning as A11, B14 to B16 each independently have the same meaning as B12, B17 has the same meaning as B11, and E12 has the same meaning as E11. F11 represents a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group (—SOH), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and —CH— constituting the alkyl group and alkoxy group may be replaced with —O—.)

[0194] The content of the polymerizable liquid crystal compound in the composition for forming a liquid crystal retardation layer is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass, relative to 100 parts by mass of the solid content of the composition for forming a liquid crystal retardation layer. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous in terms of the alignment of the obtained liquid crystal retardation layer. In this specification, the solid content of the composition for forming a liquid crystal retardation layer means all components of the polymerizable liquid crystal composition excluding volatile components such as organic solvents.

[0195] <Composition for forming liquid crystal retardation layer> The liquid crystal retardation layer is usually formed by applying a liquid crystal retardation layer-forming composition containing a polymerizable liquid crystal compound onto an alignment film formed on a substrate as needed, and polymerizing and curing the polymerizable liquid crystal compound in an aligned state.

[0196] [Alignment film and composition for forming alignment film] The alignment film has an alignment control force that aligns the polymerizable liquid crystal compound in a desired direction.

[0197] Alignment films facilitate the alignment of polymerizable liquid crystal compounds. Liquid crystal alignment states, such as horizontal alignment, vertical alignment, hybrid alignment, and tilted alignment, vary depending on the properties of the alignment film and the polymerizable liquid crystal compound, and these combinations can be selected arbitrarily. For example, if the alignment film is made of a material that exerts a horizontal alignment as an alignment control force, the polymerizable liquid crystal compound can form horizontal or hybrid alignment. If the alignment film is made of a material that exerts a vertical alignment, the polymerizable liquid crystal compound can form vertical or tilted alignment. The terms horizontal, vertical, and so on refer to the direction of the optical axis of the aligned polymerizable liquid crystal compound relative to the plane of the optically anisotropic layer. For example, vertical alignment means that the optical axis of the aligned polymerizable liquid crystal compound is perpendicular to the plane of the optically anisotropic layer. Here, vertical means 90°±20° relative to the plane of the optically anisotropic layer.

[0198] When the alignment film is made of an alignment polymer, the alignment restraining force can be adjusted arbitrarily by the surface condition or rubbing conditions, and when it is made of a photoalignment polymer, the alignment restraining force can be adjusted arbitrarily by the polarized light irradiation conditions, etc. Furthermore, the liquid crystal alignment can also be controlled by selecting the physical properties of the polymerizable liquid crystal compound, such as the surface tension or liquid crystallinity.

[0199] The alignment film formed between the substrate and the optically anisotropic layer is preferably insoluble in the solvent used to form the optically anisotropic layer on the alignment film, and is heat-resistant to the heat treatment for removing the solvent and orienting the liquid crystal. Examples of the alignment film include alignment films made of orientable polymers, photo-alignment films, groove-alignment films, and stretched films stretched in the alignment direction. When applied to a long roll film, photo-alignment films are preferred because the alignment direction can be easily controlled.

[0200] The thickness of the alignment film is usually in the range of 10 nm to 5000 nm, preferably in the range of 10 nm to 1000 nm, and more preferably in the range of 30 to 300 nm.

[0201] Examples of alignment polymers used in rubbed alignment films include polyamides and gelatins having an amide bond in the molecule, polyimides having an imide bond in the molecule, and their hydrolyzed products such as polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylic acid esters. Among these, polyvinyl alcohol is preferred. These alignment polymers may be used alone or in combination of two or more.

[0202] Rubbing methods include a method in which an oriented polymer film formed on the surface of a substrate by applying an oriented polymer composition to the substrate and annealing the composition is brought into contact with a rotating rubbing roll wrapped with a rubbing cloth.

[0203] The photo-alignment film is made of a polymer, oligomer, or monomer having a photoreactive group. The photo-alignment film can obtain an alignment control force by irradiating it with polarized light. The photo-alignment film is preferable because the direction of the alignment control force can be freely controlled by selecting the polarization direction of the irradiated polarized light.

[0204] A photoreactive group is a group that exhibits liquid crystal alignment ability upon irradiation with light. Specifically, it induces molecular alignment or a photoreaction that is the origin of liquid crystal alignment ability, such as an isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photodecomposition reaction, upon irradiation with light. Among such photoreactive groups, those that undergo a dimerization reaction or a photocrosslinking reaction are preferred because of their excellent alignment ability. As photoreactive groups capable of causing such reactions, those having an unsaturated bond, particularly a double bond, are preferred, and groups having at least one bond selected from the group consisting of a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond), and a carbon-oxygen double bond (C=O bond) are more preferred.

[0205] Examples of photoreactive groups having a C=C bond include vinyl groups, polyene groups, stilbene groups, stilbazole groups, stilbazolium groups, chalcone groups, and cinnamoyl groups. Chalcone and cinnamoyl groups are preferred because of their ease of reactivity control and the ability to exert alignment control forces during photoalignment. Examples of photoreactive groups having a C=N bond include groups having structures such as aromatic Schiff bases and aromatic hydrazones. Examples of photoreactive groups having an N=N bond include azobenzene groups, azonaphthalene groups, aromatic heterocyclic azo groups, bisazo groups, and formazan groups, as well as groups with an azoxybenzene basic structure. Examples of photoreactive groups having a C=O bond include benzophenone groups, coumarin groups, anthraquinone groups, and maleimide groups. These groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and halogenated alkyl groups.

[0206] Polarized light can be irradiated either directly from the film surface or from the substrate side and then transmitted through the film. It is particularly preferred that the polarized light be substantially parallel. The wavelength of the polarized light irradiated should be within a wavelength range in which the photoreactive group in the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) with a wavelength of 250 to 400 nm is particularly preferred. Examples of light sources used for polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and ultraviolet lasers such as KrF and ArF. High-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps are more preferred. These lamps are preferred because of their high emission intensity of ultraviolet light with a wavelength of 313 nm. Polarized light can be irradiated by passing light from the light source through an appropriate polarizer. Examples of such polarizers include polarizing filters, polarizing prisms such as Glan-Thompson and Glan-Taylor, and wire-grid polarizers.

[0207] The composition for forming an alignment film may contain a leveling agent as needed. Examples of the leveling agent include silicone-based leveling agents and / or fluorine-based leveling agents, which will be described in the section on the liquid crystal retardation layer below. The content of the leveling agent in the solid content of the composition for forming an alignment film is usually preferably 0.001 to 3 mass %, more preferably 0.01 to 3 mass %, and even more preferably 0.1 to 3 mass %.

[0208] (Composition for forming liquid crystal retardation layer) The content of the polymerizable liquid crystal compound in the composition for forming a liquid crystal retardation layer is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass, relative to 100 parts by mass of the solid content of the composition for forming a liquid crystal retardation layer. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous in terms of the alignment of the obtained liquid crystal retardation layer. In this specification, the solid content of the composition for forming a liquid crystal retardation layer means all components excluding volatile components such as organic solvents from the composition for forming a liquid crystal retardation layer.

[0209] The liquid crystal retardation layer forming composition may further contain reactive additives such as a solvent, a leveling agent, a polymerization initiator, a photosensitizer, a polymerization inhibitor, a crosslinking agent, and an adhesive agent in addition to the above polymerizable liquid crystal compound.

[0210] <Solvent> The liquid crystal retardation layer forming composition may contain a solvent. Generally, a polymerizable liquid crystal compound has a high viscosity, so that dissolving the liquid crystal retardation layer forming composition in a solvent makes it easy to apply, and as a result, it often becomes easy to form a liquid crystal retardation layer. The solvent is preferably one that can completely dissolve the polymerizable liquid crystal compound, and is also preferably a solvent that is inactive to the polymerization reaction of the polymerizable liquid crystal compound.

[0211] Examples of solvents include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene, and nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; and amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone. These solvents may be used alone or in combination.

[0212] The content of the solvent is preferably 50 to 98% by mass with respect to the total amount of the composition for forming a liquid crystal retardation layer. In other words, the content of the solid content in the composition for forming a liquid crystal retardation layer is preferably 2 to 50% by mass, more preferably 5 to 30% by mass. When the content of the solid content is 50% by mass or less, the viscosity of the composition for forming a liquid crystal retardation layer is low, and the thickness of the liquid crystal retardation layer becomes approximately uniform, which tends to reduce the occurrence of unevenness in the liquid crystal retardation layer. In addition, the content of the solid content can be determined in consideration of the thickness of the optically anisotropic layer to be produced.

[0213] <Leveling agent> The liquid crystal retardation layer forming composition may contain a leveling agent. The leveling agent is an additive that adjusts the fluidity of the composition and has the function of making the film obtained by applying the composition flatter, and examples thereof include silicone-based leveling agents, acrylic-based leveling agents, and fluorine-based leveling agents. Among these, silicone-based leveling agents and fluorine-based leveling agents are preferred, as they are excellent in reducing the tension of the film surface obtained by applying the composition.

[0214] Examples of silicone-based leveling agents include leveling agents having a polyorganosiloxane skeleton.

[0215] Examples of groups bonded to silicon atoms (silicon atoms forming siloxane bonds) in polyorganosiloxane include hydrocarbon groups, etc. The silicone leveling agent may be one in which two hydrocarbon groups are bonded to a silicon atom. There are no limitations on the group bonded to the silicon atom, but among them, alkyl groups having 1 to 10 carbon atoms and aryl groups are preferred, more preferably methyl groups and phenyl groups, and even more preferably methyl groups. The group bonded to the silicon atom may be of one type or of two or more types. The number of repetitions of the siloxane unit (degree of polymerization) is not particularly limited, but is preferably 2 to 10,000, more preferably 3 to 5,000, and even more preferably 5 to 1,000.

[0216] As the silicone leveling agent, commercially available products can be used, for example, SH710 (manufactured by Toray Dow Corning Co., Ltd.), BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315N, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330, BYK -331, BYK-333, BYK-337, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYK-370, BYK-377, BYK-378, BYK-3455, BYK-UV3510 (all manufactured by BYK Japan Co., Ltd.), KF-945, KF-6015, KF-60 20 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TEGORad2300, TEGORad2200N, TEGORad2011 (manufactured by Degussa), and those having a radical polymerizable group such as a (meth)acryloyl group added to the polyether chain include BYK-UV3500, BYK-UV3505, BYK-3510, BYK-UV3530, BYK-UV3570, BYK-UV3575, BYK-UV3576 (all manufactured by BYK Japan KK), KP-422, KP-416, KP-418, KP-410, KP-411, KP-412, KP-413, KP-423, KP-414, KP-415, KP-420, and KP-983 (all manufactured by Shin-Etsu Chemical Co., Ltd.).

[0217] The content of the silicone-based leveling agent in the composition for forming a liquid crystal retardation layer is preferably 0.001 to 2 parts by mass, more preferably 0.01 to 1.5 parts by mass, and even more preferably 0.1 to 1.5 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0218] The fluorine-based leveling agent is not particularly limited, but examples thereof include leveling agents having a fluoroaliphatic hydrocarbon skeleton. The fluoroaliphatic hydrocarbon skeleton is not particularly limited, but examples thereof include fluoroalkanes having 1 to 10 carbon atoms, such as fluoromethane, fluoroethane, fluoropropane, fluoroisopropane, fluorobutane, fluoroisobutane, fluoro-t-butane, fluoropentane, and fluorohexane. The fluoroaliphatic hydrocarbon skeleton may have at least some of the hydrogen atoms substituted with fluorine atoms, but may also be a perfluoroaliphatic hydrocarbon skeleton in which all of the hydrogen atoms are substituted with fluorine atoms.

[0219] The fluoroaliphatic hydrocarbon skeleton may also form a polyfluoroalkylene ether skeleton, which is a repeating unit via an ether bond. The fluoroaliphatic hydrocarbon group as a repeating unit is not particularly limited, but examples thereof include fluoro C1-4 alkylene groups such as fluoromethylene, fluoroethylene, fluoropropylene, and fluoroisopropylene. The fluoroaliphatic hydrocarbon group may be of one type only, or of two or more types. The number of repetitions (degree of polymerization) of the fluoroalkylene ether unit is not particularly limited, but is preferably 10 to 10,000, more preferably 30 to 5,000, and even more preferably 50 to 1,000.

[0220] Examples of fluorine-based leveling agents that can be used include commercially available products such as Megafac (registered trademark) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F-470, F-471, F-477, F-479, F-482, F-483, F-281, and F-253. F-251, F-114, F-510, F-551, F-552, F-553, F-554, F-555, F-556, F-557, F- 558, F-559, F-560, F-561, F-562, F-563, F-565, F-568, F-569, F-570, F-572, Examples of suitable surfactants include F-574, F-575, F-576, R-40, R-41, R-94, RS-56, RS-72-K, RS-75, RS-76-E, RS-76-NS, RS-78, RS-90, and DS-21 (DIC Corporation); Surflon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, and SA-100 (AGC Seimi Chemical Co., Ltd.); E1830 and E5844 (Daikin Fine Chemicals Research Institute, Inc.); and F-top EF301, F-top EF303, F-top EF351, and F-top EF352 (Mitsubishi Materials Electronic Chemicals Co., Ltd.).

[0221] The content of the fluorine-based leveling agent in the composition for forming a liquid crystal retardation layer is preferably 0.001 to 2 parts by mass, more preferably 0.01 to 1.5 parts by mass, and even more preferably 0.1 to 1.5 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0222] When the composition for forming a liquid crystal retardation layer contains various leveling agents, the amount thereof is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound. The composition for forming an optically anisotropic layer may contain two or more kinds of leveling agents.

[0223] <Polymerization initiator> The liquid crystal retardation layer forming composition may contain a polymerization initiator. The polymerization initiator is a compound that can initiate a polymerization reaction of a polymerizable liquid crystal compound or the like. As the polymerization initiator, a photopolymerization initiator that generates active radicals by the action of light is preferred from the viewpoint that it is not dependent on the phase state of the thermotropic liquid crystal.

[0224] As the photopolymerization initiator, any known photopolymerization initiator can be used as long as it is a compound that can initiate the polymerization reaction of the polymerizable liquid crystal compound.Specific examples include photopolymerization initiators that can generate active radicals or acids by the action of light, and among these, photopolymerization initiators that generate radicals by the action of light are preferred.The photopolymerization initiators can be used alone or in combination of two or more.

[0225] As the photopolymerization initiator, known photopolymerization initiators can be used. For example, photopolymerization initiators that generate active radicals include self-cleavage-type benzoin compounds, acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, oxime ester compounds, acylphosphine oxide compounds, and azo compounds. Hydrogen-abstraction-type benzophenone compounds, alkylphenone compounds, benzoin ether compounds, benzil ketal compounds, dibenzosuberone compounds, anthraquinone compounds, xanthone compounds, thioxanthone compounds, halogenoacetophenone compounds, dialkoxyacetophenone compounds, halogenobisimidazole compounds, halogenotriazine compounds, and triazine compounds. As photopolymerization initiators that generate acids, iodonium salts and sulfonium salts can be used. From the viewpoint of excellent reaction efficiency at low temperatures, self-cleavage type photopolymerization initiators are preferred, and acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, and oxime ester compounds are particularly preferred.

[0226] The content of the polymerization initiator in the liquid crystal retardation layer-forming composition can be appropriately adjusted depending on the type and amount of the polymerizable liquid crystal compound, but is usually 0.1 to 30 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the polymerization initiator is within the above range, polymerization can be carried out without disturbing the alignment of the polymerizable liquid crystal compound.

[0227] <Sensitizer> The liquid crystal retardation layer forming composition may contain a sensitizer. The sensitizer is preferably a photosensitizer. Examples of the sensitizer include xanthone compounds such as xanthone and thioxanthone (e.g., 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene compounds such as anthracene and alkoxy group-containing anthracene (e.g., dibutoxyanthracene, etc.); phenothiazine, rubrene, etc.

[0228] When the composition for forming a liquid crystal retardation layer contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the composition for forming a liquid crystal retardation layer can be further accelerated. The amount of the sensitizer used is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0229] <Antioxidants> From the viewpoint of stably progressing the polymerization reaction, the liquid crystal retardation layer forming composition may contain an antioxidant. The antioxidant can control the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound.

[0230] The antioxidant may be, for example, a primary antioxidant selected from a phenol-based antioxidant, an amine-based antioxidant, a quinone-based antioxidant, or a nitroso-based antioxidant, or may be a secondary antioxidant selected from a phosphorus-based antioxidant and a sulfur-based antioxidant.

[0231] When the composition for forming a liquid crystal retardation layer contains an antioxidant, the content of the antioxidant is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the content of the polymerizable liquid crystal compound. The antioxidants can be used alone or in combination of two or more. When the content of the antioxidant is within the above range, polymerization can be carried out without disturbing the alignment of the polymerizable liquid crystal compound.

[0232] <Reactive additives> The composition for forming a liquid crystal retardation layer may contain a reactive additive. The reactive additive preferably has a carbon-carbon unsaturated bond, an active hydrogen reactive group, or a thiol group in its molecule. The term "active hydrogen reactive group" as used herein refers to a group reactive to a group having active hydrogen, such as a carboxyl group (-COOH), a hydroxyl group (-OH), or an amino group (-NH2), and typical examples thereof include a glycidyl group, an oxazoline group, a carbodiimide group, an aziridine group, an imide group, an isocyanate group, a thioisocyanate group, and a maleic anhydride group. The reactive additive typically has 1 to 20 reactive groups, preferably 1 to 10 reactive groups.

[0233] (Second lamination layer 40) The second bonding layer 40 is disposed between the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 to bond them together. The thickness of the second bonding layer 40 is 20 to 200 nm. The thickness of the second bonding layer 40 may be 160 nm or less, 120 nm or less, or 100 nm or less.

[0234] The material of the second attaching layer 40 is not particularly limited, and may be a pressure-sensitive adhesive layer or an adhesive layer as exemplified for the first attaching layer 150, but from the viewpoint of satisfying the thickness of the second attaching layer 40 described above, an adhesive layer is preferable, and in particular, a water-based adhesive layer is preferable.

[0235] The second attaching layer 40, which is an aqueous adhesive layer, can be formed by drying an aqueous adhesive composition. The aqueous adhesive composition is an adhesive composition consisting of an aqueous solution in which an adhesive resin is dissolved in water, and from the perspective of producing a thin adhesive, the solids concentration of the aqueous adhesive composition is preferably 0.5 to 20 mass %, more preferably 1 to 15 mass %. The aqueous adhesive composition may contain a crosslinking agent such as an aldehyde compound (e.g., glyoxal), an epoxy compound, a melamine-based compound, a methylol compound, an isocyanate compound, an amine compound, or a polyvalent metal salt.

[0236] Examples of the resin for the second attaching layer 40, which is a water-based adhesive, include urethane resin and polyvinyl alcohol (PVA) resin, with PVA resin being preferred. When a polyvinyl alcohol resin is used as the resin for the second attaching layer 40, the polyvinyl alcohol resin may be a polyvinyl alcohol resin such as partially saponified polyvinyl alcohol or fully saponified polyvinyl alcohol, or a modified polyvinyl alcohol resin. Examples of the modified polyvinyl alcohol resin include a carboxyl group-modified polyvinyl alcohol resin and an acetoacetyl group-modified polyvinyl alcohol resin.

[0237] The average degree of polymerization of the polyvinyl alcohol resin (preferably an acetoacetyl group-modified polyvinyl alcohol resin) is preferably from 100 to 5500, more preferably from 500 to 4500, from the viewpoint of adhesiveness.

[0238] The degree of saponification of the polyvinyl alcohol resin (preferably an acetoacetyl group-modified polyvinyl alcohol resin) is usually 80 mol % to 100 mol %, and preferably 85 mol % or more.

[0239] The degree of modification (amount of modification) with acetoacetyl groups in the acetoacetyl group-modified polyvinyl alcohol resin is usually 0.1 mol % to 40 mol %, and preferably 0.5 mol % to 20 mol %, from the viewpoint of adhesiveness.

[0240] Among these, polyvinyl alcohol resins are preferred, and acetoacetyl-modified polyvinyl alcohol resins are more preferred, as the resin for the second attaching layer 40. That is, the second attaching layer 40 is preferably a dried and / or cured layer of an aqueous adhesive composition containing a polyvinyl alcohol resin.

[0241] In order to obtain the second attaching layer 40 having such a thickness, for example, the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 are passed between a pair of rolls while supplying an adhesive solution such as a water-based adhesive aqueous solution between them, and are attached by the pressure of the rolls to form a laminate including the first liquid crystal retardation layer, the liquid film, and the second liquid crystal retardation layer, and then the solvent such as water in the liquid film is dried by heating the laminate, etc., to form a thin second attaching layer 40. After the drying step, ultraviolet rays or electron beams can be irradiated as necessary.

[0242] In this case, by diluting the concentration of the resin contained in the adhesive solution to be applied, even if a liquid film on the order of μm, for example, about 20 μm, is formed, a second attaching layer with a thickness of 20 to 200 nm can be formed.

[0243] Furthermore, if the thicknesses of the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 are small, the liquid film is easily dried. Therefore, it is suitable that the thicknesses of both the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 are 10 μm or less, preferably 5 μm or less, and more preferably 0.3 μm or more and 3 μm or less.

[0244] (Peel strength between the first liquid crystal retardation layer and the second liquid crystal retardation layer) The peeling force between the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 is 0.20 N / 25 mm or more. The peeling force may be 0.25 N / 25 mm or more, or 0.30 N / 25 mm or more. There is no upper limit to the peeling force, but it may be, for example, 5 N / 25 mm or less.

[0245] The peel strength between the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 is the weaker of the peel strength between the second attaching layer 40 and the first liquid crystal retardation layer 30 and the peel strength between the second attaching layer 40 and the second liquid crystal retardation layer 50.

[0246] Specifically, the retardation layer laminate was cut to a width of 25 mm, a triacetyl cellulose (TAC) film was attached to the first liquid crystal retardation layer 30 of the cut retardation layer laminate via an adhesive, and a glass plate was attached to the second liquid crystal retardation layer 50 via an adhesive. Using a precision universal testing machine, the retardation layer laminate was gripped from the TAC film to the second attaching layer 40 and peeled in a 180° direction, measuring the force required to measure the adhesion. The measurement was performed at a peeling speed of 300 mm / min under conditions of a temperature of 23±2°C and a relative humidity of 50±5%. In the peel test, peeling occurred at the weaker of the interface between the first liquid crystal retardation layer 30 and the second attaching layer 40 and the interface between the second liquid crystal retardation layer 50 and the second attaching layer 40, so the peel force at the weaker of these interfaces was measured.

[0247] In measuring the peel strength, conditions not described in this specification conform to the "180-degree peel test method" defined in JIS Z0237:2009 (Test methods for adhesive tapes and adhesive sheets).

[0248] (Method and mode of manufacturing retardation layer laminate) Here, an example of a method for producing a retardation layer laminate in the case where the second attaching layer 40 is a water-based adhesive layer will be described with reference to FIG.

[0249] First, the first substrate layer 72 and the second substrate layer 74 are prepared. There are no limitations on the substrate layers, but a resin film is preferred, and a transparent resin film is more preferred. From the viewpoint of accelerating the drying of the aqueous adhesive composition as the second attaching layer 40, at least one of the first substrate layer 72 and the second substrate layer 74, and preferably both, should have a moisture permeability of 200 g / m 2 It is preferable that the period is 10 days or more. In this specification, the moisture permeability is a value measured in accordance with JIS Z 0208-1976 (Test method for moisture permeability of moisture-proof packaging materials (cup method)), and is defined as the mass (g) of water vapor passing through the boundary surface of a target layer or laminate at a temperature of 40°C, when the air on one side is kept at a relative humidity of 90% and the air on the other side is kept dry by a moisture absorbent, in 24 hours. 2 This is the value converted to per unit.

[0250] The moisture permeability of the substrate layer can be adjusted by appropriately setting the resin material and thickness. The resin material is preferably the above-mentioned triacetyl cellulose film.

[0251] Next, a first alignment film 62 is formed on the surface of the first base material layer 72 as needed, and then a first liquid crystal retardation layer 30 is formed thereon to obtain a first retardation film A having a structure of first base material layer / (first alignment film) / first liquid crystal retardation layer.

[0252] Next, a second alignment film 64 is formed on the surface of the second base layer 74 as needed, and then a second liquid crystal retardation layer 50 is formed thereon to obtain a second retardation film B having a structure of second base layer / (second alignment film) / second liquid crystal retardation layer.

[0253] The alignment film can be formed, for example, by applying the above-mentioned composition for forming an alignment film and applying a known method for imparting alignment.

[0254] The liquid crystal retardation layer can be formed, for example, by applying a liquid crystal retardation layer-forming composition containing the above-mentioned polymerizable liquid crystal compound onto, for example, an alignment layer, and polymerizing (curing) it by a known method. In this way, a pair of retardation films A and B is obtained.

[0255] Next, if necessary, the surfaces of the retardation films A and B on the liquid crystal retardation layer side are subjected to corona treatment.

[0256] Next, a pair of retardation films A and B are laminated by passing them between a pair of rolls while supplying an aqueous adhesive composition therebetween, to form a laminate including a first liquid crystal retardation layer, a liquid film, and a second liquid crystal retardation layer, and the liquid film in the obtained laminate is dried to obtain a retardation layer laminate 300 having a structure of first base material layer / (first alignment film) / first liquid crystal retardation layer / second laminating layer / second liquid crystal retardation layer / (second alignment film) / second base material layer.

[0257] The aqueous adhesive composition contains water and a resin dissolved or dispersed in water. Examples of the types and compositions of aqueous adhesive compositions are as described above, with polyvinyl alcohol resins being preferred. There are no particular limitations on the method for forming the liquid film, and any known coater can be used. The thickness of the liquid film can be appropriately determined based on the solids concentration of the aqueous adhesive composition and the desired thickness of the aqueous adhesive layer after drying.

[0258] There is no particular limitation on the drying method, and any known method can be used, such as heating in a furnace, air blowing, vacuum drying, etc. There is also no particular limitation on the drying atmosphere.

[0259] According to this embodiment, it is particularly easy to form the second bonding layer 40 with a thickness of 20 to 200 nm.

[0260] When producing the optical laminate shown in FIG. 1, the first base material layer 72 is peeled off from the retardation layer laminate 300, and when the retardation layer laminate 300 has the first alignment film 62, preferably, the first alignment film 62 is peeled off together with the first base material layer 72, and the first liquid crystal retardation layer 30 is bonded to a polarizing plate via the first bonding layer 150.

[0261] Furthermore, the second base layer 74 is peeled off from the retardation layer laminate 300, and when the retardation layer laminate 300 has the second alignment film 64, preferably, the second alignment film 64 is peeled off together with the second base layer 74, and the outer adhesive layer 500 can be attached onto the second liquid crystal retardation layer 50.

[0262] (outer adhesive layer) The optical laminate 400 can have an outer pressure-sensitive adhesive layer 500 on the side of the second liquid crystal retardation layer 50 opposite to the second attaching layer 40 . There are no particular limitations on the material or thickness of the outer pressure-sensitive adhesive layer 500, and for example, those listed for the first attaching layer can be used as appropriate. The thickness of the outer pressure-sensitive adhesive layer can be 1 μm or more and 100 μm or less, and is preferably 5 μm or more and 50 μm or less.

[0263] (Mechanism of action) This embodiment has the following advantages. According to this embodiment, interference unevenness is reduced, resulting in a good appearance, and wrinkles are less likely to occur even after repeated strong bending. The reason for this is unclear, but the following mechanism is thought to be the cause. The thickness of the second bonding layer 40 is 20 to 200 nm, and the peel strength between the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 is 0.20 N / 25 mm or more. Therefore, interference on both sides of the second bonding layer 40 is in the ultraviolet range, which is thought to suppress visual interference unevenness. Furthermore, because the second bonding layer 40 is thin and has high adhesion, the parallelism (uniformity of thickness) between the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 is easily maintained before and after bending, and it is thought that wrinkles are less likely to occur even when the film is repeatedly bent strongly.

[0264] Furthermore, when the optical laminate or the retardation layer laminate satisfies the above formulas (1) and (2), it has the effect of easily suppressing reflection of external light by the electrodes in the OLED effectively over the entire visible light range.

[0265] <Image display device> The image display device includes an optical laminate and an image display element (such as an organic EL display element). The optical laminate is disposed on the viewing side of the image display element (image display cell). The optical laminate can be attached to the image display element using a pressure-sensitive adhesive layer.

[0266] The image display device is not particularly limited, and examples thereof include organic electroluminescence (organic EL) display devices, inorganic electroluminescence (inorganic EL) display devices, liquid crystal display devices, and electroluminescence display devices.

[0267] The image display device can be used as mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic signs, measuring instruments or meters, office equipment, medical equipment, computing equipment, and the like. [Example]

[0268] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples. Unless otherwise specified, "%" and "parts" in the examples mean % by mass and parts by mass, respectively.

[0269] The present invention will be described in more detail below with reference to examples. In the examples, "%" and "parts" are by mass % and mass parts unless otherwise specified.

[0270] (Thickness measurement) The thickness of the layer was measured using a contact film thickness measuring device (Nikon Corporation, "MS-5C"). The thickness of the water-based adhesive layer was measured using an AFM (Shimadzu Corporation, "SPM9700HT") on a cross section of the optically anisotropic laminate that had been cross-sectioned using a microtome.

[0271] (Measurement of phase difference value) The retardation values ​​of the first liquid crystal retardation layer and the second liquid crystal retardation layer were measured using a retardation measurement device ("KOBRA-WR" manufactured by Oji Scientific Instruments Co., Ltd.). The retardation value of the optical laminate including the retardation layer laminate was measured using a retardation measurement device ("KOBRA-PR" manufactured by Oji Scientific Instruments Co., Ltd.) in the state where the separate film 2 was peeled off from the optical laminate and attached to glass. The in-plane retardation values ​​for light with wavelengths of 450 nm, 550 nm, and 650 nm were calculated using Cauchy's dispersion formula obtained from the measurement results of the in-plane retardation values ​​for light with wavelengths of 448.2 nm, 498.6 nm, 548.4 nm, 587.3 nm, 628.7 nm, and 748.6 nm.

[0272] (Preparation of Water-Based Adhesive Composition α) A 10% aqueous solution of acetoacetyl-modified polyvinyl alcohol with a saponification degree of 99.1 mol% (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIMER Z-200", viscosity of 4% aqueous solution 12.4 mPa·sec) was dissolved in pure water. Glyoxal as a crosslinking agent and 3-glycidoxypropyltrimethoxysilane as a silane coupling agent were mixed with this aqueous solution of acetoacetyl-modified polyvinyl alcohol so that the solids weight ratio of acetoacetyl-modified polyvinyl alcohol:crosslinking agent:silane coupling agent was 1:0.5:0.1. The mixture was then further diluted with pure water to a concentration of 3 parts acetoacetyl-modified polyvinyl alcohol per 100 parts water, to prepare aqueous adhesive composition α.

[0273] (Preparation of adhesive 1 (active energy ray curing adhesive 1)) The following components were blended and mixed, and then degassed to prepare an active energy ray-curable adhesive. [Cationic polymerizable compounds] Neopentyl glycol diglycidyl ether (product name: EX-211L, manufactured by Nagase ChemteX Corporation) 30 parts by mass 13 parts by mass of 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane (trade name: OXT-221, manufactured by Toagosei Co., Ltd.) 45 parts by weight of bisphenol A epoxy resin (product name: EP-4100E, ADEKA Corporation, viscosity 13 Pa·s (temperature 25°C)) ·Aromatic-containing oxetane compound (product name: TCM-104, manufactured by TRONLY) 12 parts by mass [Cationic photopolymerization initiator] CPI-100P, manufactured by San-Apro Co., Ltd., 50% propylene carbonate solution, 2.25 parts by weight (solid content) [Photosensitizer] 1,4-diethoxynaphthalene 1 part by mass

[0274] The adhesive layer, which was the cured product of Adhesive 1, had a refractive index of 1.54 for light with a wavelength of 589 nm.

[0275] (Preparation of adhesive 2 (active energy ray curing adhesive 2)) The following components were blended and mixed, and then degassed to prepare an active energy ray-curable adhesive. [Cationic polymerizable compounds] 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate Silyl ester (product name: CEL2021P, manufactured by Daicel Corporation): 70 parts by mass Neopentyl glycol diglycidyl ether (trade name: EX-211, Nagase Chemte Manufactured by OX Co., Ltd.): 20 parts by mass 2-Ethylhexyl glycidyl ether (product name: EX-121, Nagase ChemteX) Co., Ltd.): 10 parts by mass [Cationic photopolymerization initiator] Cationic polymerization initiator (product name: CPI-100P_50% solution propylene carbonate solution, manufactured by San-Apro Co., Ltd.) : 4.5 parts by weight (actual solid content 2.25 parts by weight) [Photosensitizer] 1,4-diethoxynaphthalene: 2 parts by mass

[0276] The adhesive layer, which was the cured product of adhesive 2, had a refractive index of 1.51 for light with a wavelength of 589 nm.

[0277] (Preparation of adhesive 3 (active energy ray curing adhesive 3)) The following components were blended and mixed, and then degassed to prepare an active energy ray-curable adhesive. [Cationic polymerizable compounds] 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate Silyl silane (product name: CEL2021P, manufactured by Daicel Corporation): 19 parts by mass Neopentyl glycol diglycidyl ether (trade name: EX-211, Nagase Chemte Manufactured by OX Co., Ltd.): 64 parts by mass 2-Ethylhexyl glycidyl ether (product name: EX-121, Nagase ChemteX) Co., Ltd.): 7 parts by weight 10 parts by weight of a polymer (GMA-PMMA (polymethyl methacrylate) copolymer) having a weight-average molecular weight of 15,000 obtained by radical polymerization of a monomer consisting of 25 parts of glycidyl methacrylate and 75 parts of methyl methacrylate [Cationic photopolymerization initiator] Cationic polymerization initiator (product name: CPI-100P_50% solution propylene carbonate solution, manufactured by San-Apro Co., Ltd.) : 4.5 parts by weight (actual solid content 2.25 parts by weight)

[0278] The adhesive layer, which was the cured product of Adhesive 3, had a refractive index of 1.50 for light with a wavelength of 589 nm.

[0279] (Preparation of Pressure-Sensitive Adhesive Layer (1)) Preparation of acrylic resin solution (1) A reaction vessel equipped with a condenser, nitrogen inlet, thermometer, and stirrer was charged with a mixed solution of 100 parts ethyl acetate, 99.0 parts butyl acrylate, 0.5 parts 2-hydroxyethyl acrylate, and 0.5 parts acrylic acid. The air in the vessel was purged with nitrogen gas to remove oxygen, and the internal temperature was raised to 55°C. A solution of 0.12 parts azobisisobutyronitrile (polymerization initiator) in 10 parts ethyl acetate was then added in its entirety. After the addition of the polymerization initiator, the temperature was maintained for 1 hour. Ethyl acetate was then continuously added to the reaction vessel at a rate of 17.3 parts / hour while maintaining the internal temperature at 54-56°C. The addition of ethyl acetate was stopped when the (meth)acrylic resin concentration reached 35% by mass, and the vessel was then maintained at this temperature for 6 hours. Finally, ethyl acetate was added to adjust the (meth)acrylic resin concentration to 20% by mass, preparing acrylic resin solution (1). The resulting acrylic resin had a weight average molecular weight Mw of 1.7 million and a molecular weight distribution Mw / Mn of 3.9. Mw and Mn were measured using a GPC system with a TSKgel GMH column manufactured by Tosoh Corporation. HR Two "-H(S)" were connected in series, and tetrahydrofuran was used as the eluent. Measurements were performed in terms of standard polystyrene under the following conditions: sample concentration 2 mg / mL, sample introduction volume 100 μL, temperature 40°C, and flow rate 1 mL / min.

[0280] Preparation of Pressure-Sensitive Adhesive Composition (1) To 80 parts of the solid content of the acrylic resin solution (1) obtained above, 20 parts (solid content) of a bifunctional acrylate (obtained from Shin-Nakamura Chemical Co., Ltd.; product number "A-DOG"), 2.5 parts (active ingredient basis) of a crosslinking agent (manufactured by Tosoh Corporation: product name "Coronate L" (an ethyl acetate solution of a trimethylolpropane adduct of tolylene diisocyanate (solid content concentration 75% by mass)), 1.5 parts of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals: product name "Irgacure 500"), and 0.3 parts of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.: product name "KBM-403") were added, and ethyl acetate was further added to make the solid content concentration 13%, thereby obtaining a pressure-sensitive adhesive composition (1). A-DOG is a diacrylate of an acetal compound of hydroxypivalaldehyde and trimethylolpropane and has the structure of the following formula. [Chemical formula]

[0281] Preparation of the adhesive sheet (1) The adhesive composition (1) prepared above was applied to the release-treated surface of a separate film 1 made of a polyethylene terephthalate film with a release treatment (''PLZ-383030'' obtained from Lintec Corporation) using an applicator so that the thickness after drying would be 5 μm, and dried at 100°C for 1 minute to prepare an adhesive layer (1). Next, the surface of the obtained adhesive layer (1) opposite to the separator film was bonded to the release-treated surface of a separate film 2 made of a polyethylene terephthalate film with a release treatment (''PLR-381031'' obtained from Lintec Corporation). Subsequently, ultraviolet rays were irradiated under the following conditions to prepare an adhesive sheet (1) composed of separate film 1 / adhesive layer (1) / separate film 2. Also, the refractive index of the above adhesive layer (1) with respect to light with a wavelength of 589 nm was 1.48. <UV irradiation conditions> ·Using a Fusion UV lamp system (manufactured by Fusion UV Systems) H bulb ·Integrated light quantity 250 mJ / cm 2

[0282] <Preparation of the adhesive layer (2)> Preparation of the acrylic resin solution (2) A reaction vessel equipped with a condenser, nitrogen inlet, thermometer, and stirrer was charged with a mixed solution of 81.8 parts ethyl acetate, 90.0 parts butyl acrylate, 5.0 parts methyl acrylate, and 5.0 parts acrylic acid. The air in the vessel was purged with nitrogen gas to remove oxygen, and the internal temperature was raised to 55°C. A solution of 0.15 parts azobisisobutyronitrile (polymerization initiator) in 10 parts ethyl acetate was then added in its entirety. After the addition of the polymerization initiator, the temperature was maintained for 1 hour. Ethyl acetate was then continuously added to the reaction vessel at a rate of 17.3 parts / hour while maintaining the internal temperature at 54-56°C. When the (meth)acrylic resin concentration reached 35% by mass, the ethyl acetate addition was stopped. The temperature was maintained for 6 hours after the start of the ethyl acetate addition. Finally, ethyl acetate was added to adjust the (meth)acrylic resin concentration to 20% by mass, preparing acrylic resin solution (2). The resulting acrylic resin had a weight average molecular weight Mw of 1.6 million and a molecular weight distribution Mw / Mn of 4.5. Mw and Mn were measured using a GPC system with a TSKgel GMH column manufactured by Tosoh Corporation. HR Two "-H(S)" were connected in series, and tetrahydrofuran was used as the eluent. Measurements were performed in terms of standard polystyrene under the following conditions: sample concentration 2 mg / mL, sample introduction volume 100 μL, temperature 40°C, and flow rate 1 mL / min.

[0283] Preparation of Pressure-Sensitive Adhesive Composition (2) To 100 parts of the solid content of the acrylic resin solution (2) obtained above, 0.15 parts on an active ingredient basis of a crosslinking agent (manufactured by Tosoh Corporation: trade name "Coronate L" (an ethyl acetate solution of a trimethylolpropane adduct of tolylene diisocyanate (solid content concentration 75% by mass)) and 0.2 parts of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.: trade name "KBM-403") were added, and ethyl acetate was further added to make the solid content concentration 13%, thereby obtaining a pressure-sensitive adhesive composition (2).

[0284] Preparation of adhesive sheet (2) The pressure-sensitive adhesive composition (2) prepared above was applied using an applicator to the release-treated surface of a separate film 1 ("PLR-382190" available from Lintec Corporation) made of a release-treated polyethylene terephthalate film so that the thickness after drying would be 25 μm, and the applied film was dried at 100° C. for 1 minute to produce a pressure-sensitive adhesive layer (2). Next, the surface of the resulting pressure-sensitive adhesive layer (2) opposite the separator film was laminated to the release-treated surface of a separate film 2 ("PET-251130" available from Lintec Corporation) made of a release-treated polyethylene terephthalate film to produce a pressure-sensitive adhesive sheet (2) consisting of separate film 1 / pressure-sensitive adhesive layer (2) / separate film 2.

[0285] (Fabrication of polarizer) A polyvinyl alcohol film having a thickness of 20 μm, a degree of polymerization of 2400, and a degree of saponification of 99% or more was uniaxially stretched to a stretching ratio of 4.5 times on a heated roll, and while maintaining tension, was immersed for 60 seconds in a dye bath at 28°C containing 0.05 parts by mass of iodine and 5 parts by mass of potassium iodide per 100 parts by mass of water.

[0286] Next, the film was immersed for 110 seconds in a boric acid aqueous solution 1 at 64°C containing 5.5 parts by mass of boric acid and 15 parts by mass of potassium iodide per 100 parts by mass of water. The film was then immersed for 30 seconds in a boric acid aqueous solution 2 at 67°C containing 5.5 parts by mass of boric acid and 15 parts by mass of potassium iodide per 100 parts by mass of water. The film was then washed with pure water at 10°C and dried to obtain a polarizer. The polarizer had a thickness of 8 μm and a boron content of 4.3% by mass.

[0287] (Preparation of polarizing plate) The aqueous adhesive composition α obtained above was applied to one side of the polarizer obtained above, and a COP film (cycloolefin polymer film, manufactured by Zeon Corporation, 23 μm) was laminated thereon. The aqueous adhesive composition α obtained above was applied to the other side of the polarizer, and a TAC film (triacetyl cellulose film, manufactured by Konica Minolta, 20 μm) was laminated thereon. The resulting mixture was dried at a temperature of 80°C for 5 minutes to obtain a polarizing plate having protective films on both sides of the polarizer. The layer structure of the polarizing plate was COP film / aqueous adhesive layer / polarizer / aqueous adhesive layer / TAC film. The refractive index of the TAC film for light with a wavelength of 589 nm was 1.47.

[0288] (Preparation of First Liquid Crystal Retardation Layer and Second Liquid Crystal Retardation Layer) (1) Preparation of Oriented Polymer Composition (1) Water was added to commercially available polyvinyl alcohol (polyvinyl alcohol 1000 fully saponified type, manufactured by Wako Pure Chemical Industries, Ltd.), and the mixture was heated at 100° C. for 1 hour to obtain an oriented polymer composition (1).

[0289] (2) Preparation of photo-alignable polymer composition (1) The photoalignment material (weight average molecular weight: 50,000, m:n = 50:50) with the following structure was produced in accordance with the method described in JP 2021-196514 A. Photoalignment polymer composition (1) was prepared by mixing 2 parts of the photoalignment material and 98 parts of propylene glycol monomethyl ether (PGME, solvent) as components and stirring the resulting mixture at 80 ° C for 1 hour. Photoalignable materials: [ka]

[0290] (Production of polymerizable liquid crystal compounds) Polymerizable liquid crystal compound (A1) and polymerizable liquid crystal compound (A2) having the structures shown below were prepared. The polymerizable liquid crystal compound (A1) and polymerizable liquid crystal compound (A2) were prepared in the same manner as described in JP-A-2010-244038.

[0291] Polymerizable liquid crystal compound (A1): [ka]

[0292] Polymerizable liquid crystal compound (A2): [ka]

[0293] (Preparation of liquid crystal retardation layer forming composition (Y1)) Polymerizable liquid crystal compound (A1) and polymerizable liquid crystal compound (A2) were mixed in a mass ratio of 80:20 to obtain a mixture. To 100 parts of the obtained mixture, parts of leveling agent "Megafac F-556" (manufactured by DIC Corporation), parts of photopolymerization initiator "Omnirad907" (manufactured by IGM Resin BV), and ionic compound (B) were added. Furthermore, cyclopentanone was added, and the mixture was stirred at a temperature of 80°C for 1 hour to prepare a retardation film-forming composition (Y1). The amount of each component added is as shown in Table 1 below.

[0294] [Table 1]

[0295] Ionic compounds (B): [ka]

[0296] (Preparation of liquid crystal retardation layer forming composition (Y2)) The polymerizable liquid crystal compound Paliocolor LC242 (manufactured by BASF Japan), the leveling agent "BYK-361N" (manufactured by BYK-Chemie), and the photopolymerization initiator "Omnirad907" (manufactured by IGM Resin BV) were added. Furthermore, propylene glycol 1-monomethyl ether 2-acetate (PGME) was added, and the mixture was stirred at a temperature of 80°C for 1 hour to prepare a retardation film-forming composition (Y2). The amounts of each component added are shown in Table 2 below.

[0297] [Table 2]

[0298] Polymerizable liquid crystal compound LC242: [ka]

[0299] (Preparation of retardation film (Z1)) Triacetyl cellulose film (TAC) cut into a rectangular shape (thickness 40 μm, moisture permeability 950 g / m at a temperature of 40°C and a relative humidity of 90% RH) 2 An oriented polymer composition (1) was applied to the TAC film (1) for 24 hours, and an oriented polymer film was formed so that the thickness after heat drying would be 100 nm. The surface of the obtained oriented polymer film was rubbed at an angle from the longitudinal direction of the TAC such that the slow axis of the retardation film (Z1) formed below would be aligned at -15°, and then a liquid crystal retardation layer-forming composition (Y1) was applied thereon using a bar coater. The obtained coating film was dried at 100°C for 1 minute and then cooled to room temperature to obtain a dried film. Next, a high-pressure mercury lamp ("Uniquer VB-15201BY-A" manufactured by Ushio Inc.) was used to expose the film to 1000 mJ / cm under a nitrogen atmosphere. 2The dried coating was irradiated with ultraviolet light (365 nm standard) to form a first liquid crystal retardation layer (X1) in which the polymerizable liquid crystal compound was cured in a state where it was aligned horizontally relative to the substrate surface, resulting in a retardation film (Z1) consisting of TAC / alignment film / first liquid crystal retardation layer (X1) (horizontally aligned liquid crystal cured film). The thickness of the obtained first liquid crystal retardation layer (X1) was measured using a scanning white light interference microscope and found to be 1.8 μm. The in-plane retardation values ​​were measured using a KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. The in-plane retardation values ​​at a wavelength of 550 nm were Re(550) = 236 nm, at a wavelength of 450 nm were Re(450) = 256 nm, and at a wavelength of 650 nm were Re(650) = 231 nm. Note that the retardation value of TAC at a wavelength of 550 nm is approximately 0, so this does not affect the optical properties. The orientation angle was −15° with respect to the longitudinal direction of the TAC when viewed from the first liquid crystal retardation layer side. The first liquid crystal retardation layer was a positive dispersion λ / 2 plate.

[0300] (Preparation of retardation film (Z2)) Triacetyl cellulose film (TAC) cut into a rectangular shape (thickness 40 μm, moisture permeability 950 g / m at a temperature of 40°C and a relative humidity of 90% RH) 2 A photoalignable polymer composition (1) was applied to the TAC film for 24 hours. The resulting coating was dried at 120°C for 2 minutes and then cooled to room temperature to form a dry film. Furthermore, a UV irradiation device was used to continuously irradiate the film with 100 mJ of polarized ultraviolet light (313 nm standard) at an angle of 75° to the longitudinal direction of the TAC film, forming a 100 nm photoalignment film. A liquid crystal retardation layer-forming composition (Y2) was applied thereon using a bar coater. The resulting coating was dried at 100°C for 1 minute and then cooled to room temperature to obtain a dry film. Next, a high-pressure mercury lamp was used to irradiate the film with an exposure dose of 1000 mJ / cm under a nitrogen atmosphere. 2The dried film was continuously irradiated with ultraviolet light (365 nm standard) to form a second liquid crystal retardation layer (X2) in which the polymerizable liquid crystal compound was cured while oriented horizontally relative to the substrate surface, resulting in a retardation film (Z2) consisting of TAC, alignment film, and second liquid crystal retardation layer (X2) (horizontally aligned cured liquid crystal film). The thickness of the resulting second liquid crystal retardation film (X2) was measured using a scanning white light interference microscope and found to be 1.0 μm. The in-plane retardation values ​​were measured using a KOBRA-WR microscope manufactured by Oji Scientific Instruments. The in-plane retardation values ​​at a wavelength of 550 nm were Re(550) = 115 nm, at a wavelength of 450 nm, Re(450) = 130 nm, and at a wavelength of 650 nm, Re(650) = 111 nm. Since the retardation value of TAC at a wavelength of 550 nm is approximately 0, this does not affect its optical properties. The orientation angle was 75° with respect to the longitudinal direction of the TAC when viewed from the second liquid crystal retardation layer side. The second liquid crystal retardation layer was a positive dispersion λ / 4 plate.

[0301] (Preparation of Water-Based Adhesive Composition β) The following composition liquid A and composition liquid B were mixed at room temperature in a mass ratio of 1:1 and stirred for 30 minutes to prepare a water-based adhesive composition β for forming a water-based adhesive layer. Composition solution A: An acetoacetyl-modified polyvinyl alcohol resin with a saponification degree of 99.2 mol% (Gohsenol Z200, manufactured by Mitsubishi Chemical Corporation) was dissolved in water (distilled water) to prepare a PVA aqueous solution with a solids content of 8% by mass. The prepared 8% by mass PVA solution and a 40% aqueous glyoxal solution were mixed in a mass ratio of 3.0:0.7, and the total solids content was adjusted to 3 parts per 100 parts of water to produce composition solution A. Composition solution B: An acetoacetyl-modified polyvinyl alcohol resin with a saponification degree of 99.2 mol% ("GOHSENOL Z200" manufactured by Mitsubishi Chemical Corporation) was dissolved in water (distilled water) to prepare a PVA aqueous solution with a solid content of 8 mass%. The prepared 8 mass% PVA solution and zinc chloride were mixed in a mass ratio of 3.0:0.09, and the total solid content was adjusted to 3 parts per 100 parts of water to prepare composition solution B.

[0302] (Preparation of Retardation Layer Laminate 1) 28 kJ / m2 to the first liquid crystal retardation layer (X1) of the retardation film (Z1) and the second liquid crystal retardation layer (X2) of the retardation film (Z2), respectively 2 A corona treatment was performed under the conditions of (a) to (c). A coating of the aqueous adhesive composition β was formed on the first liquid crystal retardation layer (X1) of the retardation film (Z1) so that the thickness of the aqueous adhesive layer after drying would be any desired thickness (0.01 to 0.25 μm). Thereafter, the second liquid crystal retardation layer (X2) of the retardation film (Z2) was laminated on the coating of the aqueous adhesive composition β so that the longitudinal direction was aligned with that of the retardation film (Z1), and dried for 3 minutes in an atmospheric atmosphere at a temperature of 90°C to obtain a retardation layer laminate 1 in which TAC / alignment film / first liquid crystal retardation layer (X1) / aqueous adhesive layer / second liquid crystal retardation layer (X2) / alignment film / TAC were laminated in this order.

[0303] (Preparation of Retardation Layer Laminate 2) 28 kJ / m2 to the first liquid crystal retardation layer (X1) of the retardation film (Z1) and the second liquid crystal retardation layer (X2) of the retardation film (Z2), respectively. 2 The corona treatment was carried out under the following conditions. Adhesive 1 was applied onto the first liquid crystal retardation layer (X1) of the retardation film (Z1) so that the thickness of the adhesive 1 after curing would be 2 μm, and then the second liquid crystal retardation layer (X2) surface of the retardation film (Z2) was laminated onto the coating of adhesive 1 so that the longitudinal direction was aligned with that of the retardation film (Z1). Ultraviolet light was irradiated from the retardation film (Z2) side to cure the adhesive 1, thereby obtaining a retardation layer laminate 2 in which TAC / alignment film / first liquid crystal retardation layer (X1) / adhesive layer 1 / second liquid crystal retardation layer (X2) / alignment film / TAC were laminated in this order. The ultraviolet light was UVA with a wavelength of 320 nm to 390 nm at 420 mJ / cm 2 The irradiation was carried out so that

[0304] (Production of Retardation Layer Laminate 3) 28 kJ / m2 to the first liquid crystal retardation layer (X1) of the retardation film (Z1) and the second liquid crystal retardation layer (X2) of the retardation film (Z2), respectively. 2A corona treatment was carried out under the conditions of 28 kJ / m for the aqueous adhesive layer. A coating of the aqueous adhesive composition β was formed on the first liquid crystal retardation layer (X1) of the retardation film (Z1) so that the thickness of the aqueous adhesive layer after drying would be 0.1 μm. Thereafter, a release film [a triacetyl cellulose resin (TAC) film having a thickness of 25 μm that had been subjected to a release treatment] was laminated on the coating of the aqueous adhesive composition β, and after drying for 3 minutes in an atmospheric atmosphere at a temperature of 90°C, the release film was peeled off to obtain an aqueous adhesive layer with a thickness of 0.1 μm. 2 After corona treatment, the second liquid crystal retardation layer (X2) side of the retardation film (Z2) was attached to the retardation film (Z1) so that the longitudinal direction was aligned, to obtain a laminate having a layer structure of TAC / alignment film / first liquid crystal retardation layer (X1) / water-based adhesive layer / second liquid crystal retardation layer (X2) / alignment film / TAC. The obtained laminate was heated in an air atmosphere at a temperature of 80°C for 10 minutes to perform a curing process, to obtain a retardation layer laminate 3.

[0305] (Examples 1 to 3, Comparative Examples 3 and 4) The TAC / alignment film on the first liquid crystal retardation layer (X1) side of each retardation layer laminate 1 was peeled off so that the thickness of the aqueous adhesive layer after drying would be 0.01 to 0.25 μm, and 28 kJ / m 2Corona treatment was carried out under the following conditions. Adhesive 2 was applied onto the first liquid crystal retardation layer (X1) so that the thickness of adhesive 2 after curing would be 2 μm, and then the TAC surface side of polarizing plate (1) was laminated onto the coating of adhesive 2 so that its absorption axis was at 90° to the longitudinal direction of the retardation layer laminate, that is, so that the transmission axis of the polarizing plate was aligned with the longitudinal direction of the retardation layer laminate. Ultraviolet light was irradiated from the retardation film (Z2) side to cure adhesive 2. The alignment film / TAC on the second liquid crystal retardation layer (X2) side of the obtained laminate was peeled off, the separate film 1 was peeled off from the pressure-sensitive adhesive sheet (2), and the pressure-sensitive adhesive layer (2) side was attached to the second liquid crystal retardation layer (X2) to obtain an optical laminate in which the following layers were laminated in this order: COP film / aqueous adhesive layer / polarizer / aqueous adhesive layer / TAC film / adhesive layer 2 / first liquid crystal retardation layer (X1) / aqueous adhesive layer / second liquid crystal retardation layer (X2) / adhesive layer (2) / separate film 2. Details of the thickness of the aqueous adhesive layer after drying formed on the TAC surface of the retardation layer laminate 1 and polarizing plate (1) in each example are shown in Table 1.

[0306] Example 4 The separate film 1 was peeled off from the adhesive sheet (1), and the adhesive layer (1) was subjected to a load of 28 kJ / m 2 After that, the pressure-sensitive adhesive layer (1) side was attached to the TAC surface of the polarizing plate (1). The separate film 2 of the obtained laminate was peeled off, and the pressure-sensitive adhesive layer (1) side was subjected to a corona treatment at 28 kJ / m 2After peeling off the TAC / alignment film on the first liquid crystal retardation layer (X1) side of the retardation layer laminate 1 prepared so that the thickness of the aqueous adhesive layer after drying would be 0.04 μm, the first liquid crystal retardation layer (X1) was subjected to a corona treatment under the condition of 28 kJ / m2. The first liquid crystal retardation layer (X1) of the retardation layer laminate was bonded to the adhesive layer (1) surface of the polarizing plate (1) with the adhesive layer (1) obtained above so that the absorption axis of the polarizing plate (1) was at 90° to the longitudinal direction of the retardation layer laminate, i.e., so that the transmission axis of the polarizing plate was aligned with the longitudinal direction of the retardation layer laminate. The alignment film / TAC on the second liquid crystal retardation layer (X2) side of the resulting laminate was peeled off, and the separate film 1 was peeled off from the adhesive sheet (2). The adhesive layer (2) side was then bonded to the second liquid crystal retardation layer (X2), thereby obtaining an optical laminate in which the COP film / aqueous adhesive layer / polarizer / aqueous adhesive layer / TAC film / adhesive layer (1) / first liquid crystal retardation layer (X1) / aqueous adhesive layer / second liquid crystal retardation layer (X2) / adhesive layer (2) / separate film 2 were laminated in this order.

[0307] Example 5 An optical laminate was obtained in the same manner as in Example 1, except that adhesive 3 was used for the first attaching layer.

[0308] (Comparative Example 1) An optical laminate was obtained in the same manner as in Example 1 except that the retardation layer laminate 2 was used.

[0309] (Comparative Example 2) An optical laminate was obtained in the same manner as in Example 1 except that the retardation layer laminate 3 was used.

[0310] <Evaluation> (Refractive index of adhesive layer) The prepared adhesive was applied to one side of a stretched norbornene resin film ("ZEONORFILM" manufactured by Nippon Zeon Co., Ltd.) using a bar coater (manufactured by Daiichi Rika Co., Ltd.) so that the thickness after ultraviolet irradiation would be approximately 30 μm. An ultraviolet irradiation device (manufactured by Fusion UV Systems Co., Ltd.) was used to apply an integrated light dose of 600 mJ / cm. 2The norbornene-based resin film was peeled off from the cured product, and the refractive index (589 nm) of the cured product layer was measured at 25°C using a multi-wavelength Abbe refractometer (DR-M2, manufactured by Atago Co., Ltd.).

[0311] (Refractive index of adhesive layer) After peeling the separator film from the adhesive layers 1 and 2 formed on the separator film, the refractive index (589 nm) of the adhesive layers 1 and 2 was measured using a multi-wavelength Abbe refractometer ("DR-M2" manufactured by Atago Co., Ltd.) in an environment of 25°C.

[0312] (Refractive index of TAC film) The refractive index of the retardation film was measured by using an ellipsometer M-220 manufactured by JASCO Corporation, with the in-plane average refractive index (589 nm) being in a state where the film was attached to glass via an adhesive.

[0313] (Evaluation of interference unevenness in optical laminates) The optical laminate was cut into a size of 150 mm x 150 mm. The cut optical laminate was attached to an aluminum reflector to obtain a test specimen for interference unevenness observation. The test specimen for interference unevenness observation was placed on a stand so that the angle between the floor and the floor was 45° when the floor was set at 0°. Linear polarizers were placed between the three-band fluorescent lamp as a light source and the test specimen for interference unevenness observation, and between the test specimen and the observer, with their transmission axes perpendicular to each other (crossed Nicols). Light from the three-band fluorescent lamp was irradiated onto the test specimen for interference unevenness observation from a 90° angle (above the test specimen for interference unevenness observation). When the observer observed the test specimen from the 0° angle, the test specimen was rotated and observed and evaluated from various angles. AA: No visible interference irregularities A: Almost no visible interference unevenness B: Interference unevenness is visible, but weaker than C C: Interference unevenness is visible D: Strong interference unevenness or adhesion unevenness is visible

[0314] (Evaluation of peel strength of retardation layer laminate) Retardation layer laminates 1 to 3 were cut to a width of 25 mm. The TAC / alignment film on the first liquid crystal retardation layer (X1) side of the cut retardation layer laminate was peeled off, exposing the liquid crystal retardation layer. A triacetyl cellulose (TAC) film (40 μm thick) was then attached to the liquid crystal retardation layer surface via a pressure-sensitive adhesive. The substrate film of the TAC / alignment film on the second liquid crystal retardation layer (X2) side was then peeled off, exposing the liquid crystal retardation layer. A glass plate was then attached to the liquid crystal retardation layer surface via an adhesive to obtain a measurement sample with a layer structure of TAC film / adhesive / first liquid crystal retardation layer (X1) / adhesive layer / second liquid crystal retardation layer (X2) / adhesive / glass plate. The adhesion strength was measured by gripping the measurement sample from the TAC film to the adhesive layer and measuring the force required to peel it off in a 180° direction using a precision universal testing machine (Shimadzu Corporation, Autograph AGS-50NX). The measurement was carried out at a peel speed of 300 mm / min under an environment of a temperature of 23±2°C and a relative humidity of 50±5%. In the peel test, peeling was carried out at the weaker of the interface between X2 and the adhesive layer and the interface between X2 and the adhesive layer, and the peel strength of the weaker interface was measured.

[0315] (Evaluation of flexibility) A test piece (rectangle) with a length of 50 mm (long side) and a width of 15 mm (short side) was cut out from the optical laminate, with the absorption axis of the linear polarizer as the longitudinal direction. As shown in Figure 3, this test piece (S) was bent so that its two short sides (S1) faced each other, forming a curved section (C) in the center of its long side. While maintaining this state, the test piece was held between two parallel, flat glass plates (G) and the distance between the two glass plates (G) was reduced until the diameter of curvature (R) of the curved section of the test piece was 10 mm. This reduction step was followed by an expansion step in which the distance between the two glass plates was increased until the curved state was resolved. This was repeated 10 times to perform a 10 mm bending test. The two short sides (S1) of the test piece (S) were fixed to the glass plates (G). If no wrinkle defects occurred on the test piece after the 10 mm bending test, a 5 mm bending test was conducted on the same test piece, repeating the contraction process and expansion process 10 times in the same manner as above, except that the curvature diameter R of the bent portion was set to 5 mm. If no wrinkle defects occurred on the test piece after the 5 mm bending test, a 4 mm bending test was conducted on the same test piece, repeating the contraction process and expansion process 10 times in the same manner as above, except that the curvature diameter R of the bent portion was set to 4 mm. If no wrinkle defects occurred on the test piece after the 4 mm bending test, a 3 mm bending test was conducted on the same test piece, repeating the contraction process and expansion process 10 times in the same manner as above, except that the curvature diameter R of the bent portion was set to 3 mm. If no wrinkle defects occurred on the test piece after the 3 mm bending test, a 2 mm bending test was conducted on the same test piece, repeating the contraction process and expansion process 10 times in the same manner as above, except that the curvature diameter R of the bent portion was set to 2 mm.

[0316] (Arithmetic mean roughness Ra (flatness) of the first bonding layer on the liquid crystal retardation layer side) A rectangular optical laminate piece 50 mm long and 15 mm wide with the absorption axis of the linear polarizer in the long side direction was cut out from the optical laminate, the separate film 2 was peeled off to expose the adhesive layer (2), and the exposed adhesive layer (2) was attached to an acrylic plate (black) to prepare a test piece. Light was applied to this test piece from the COP film side, and the arithmetic mean roughness Ra of the interface between the first bonding layer (adhesive layer 2 or adhesive layer (1)) of the optical laminate and the first liquid crystal retardation layer (X1) was measured using a scanning white light interference microscope ("VS1000" manufactured by Hitachi High-Tech Science Corporation) in layer cross-section analysis mode. The measurement conditions were as follows: Camera: Sony "XCL-32" Objective lens: 5CTI Lens barrel: 1.0X Zoom lens: 1X Light source:530White Measuring device: Piezo Measurement mode: Wave The conditions and results are shown in Tables 3 and 4.

[0317] [Table 3]

[0318] [Table 4] [Explanation of symbols]

[0319] 30...first liquid crystal retardation layer, 40...second bonding layer, 50...second liquid crystal retardation layer, 72...first base material layer, 74...second base material layer, 150...first bonding layer, 180...first protective layer, 190...second protective layer, 220...linear polarizer, 300...retardation layer laminate, 400...optical laminate (circular polarizing plate)

Claims

1. A retardation layer laminate having, in this order, a first liquid crystal retardation layer, a second bonding layer having a thickness of 20 to 200 nm, and a second liquid crystal retardation layer, A retardation layer laminate in which the peel strength between the first liquid crystal retardation layer and the second liquid crystal retardation layer is 0.20 N / 25 mm or more.

2. The retardation layer laminate according to claim 1 , wherein the second attachment layer is a polyvinyl alcohol-based resin layer.

3. The retardation layer laminate according to claim 1 or 2, wherein the first liquid crystal retardation layer and the second liquid crystal retardation layer each have a thickness of 5 μm or less.

4. a first base material layer provided on the opposite side of the first liquid crystal retardation layer from the second bonding layer; a second base material layer provided on the opposite side of the second liquid crystal retardation layer from the second bonding layer, and at least one of the first base material layer and the second base material layer has a moisture permeability of 200 g / m ２ The retardation layer laminate according to claim 1 or 2, wherein the retardation layer laminate has a wavelength of 100 nm or more.

5. a step of laminating the first liquid crystal retardation layer and the second liquid crystal retardation layer by passing them between a pair of rolls while supplying an aqueous adhesive composition containing water and a resin dissolved or dispersed in water between the first liquid crystal retardation layer and the second liquid crystal retardation layer, thereby obtaining a laminate including the first liquid crystal retardation layer, the liquid film, and the second liquid crystal retardation layer; The method for manufacturing a retardation layer laminate according to claim 1 , further comprising the step of: drying the liquid film in the laminate.

6. a first protective layer, a linear polarizer, a second protective layer, a first attaching layer, and a retardation layer laminate in this order; the retardation layer laminate has a first liquid crystal retardation layer, a second attachment layer having a thickness of 20 to 200 nm, and a second liquid crystal retardation layer in this order from the first attachment layer side, The optical laminate, wherein the peel strength between the first liquid crystal retardation layer and the second liquid crystal retardation layer is 0.20 N / 25 mm or more.

7. The arithmetic mean roughness Ra of the first bonding layer on the retardation layer laminate side is 35 nm or less. The optical laminate according to claim 6.

8. The optical laminate according to claim 6 or 7, wherein the first attaching layer is a pressure-sensitive adhesive layer.

9. The optical laminate according to claim 6 or 7, wherein the angle θ between the slow axis of the first liquid crystal retardation layer and the transmission axis of the linear polarizer is 10° to 20° or −10° to −20°.

10. The optical laminate according to claim 6 or 7, wherein Re(λ) is an in-plane retardation value of the retardation layer laminate for light having a wavelength of λ nm, and the following formulas (1) and (2) are satisfied. 70 nm≦Re(450)≦150 nm (1) Re(450) / Re(550)≦1.00 (2)

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