Optical stack

Abstract

The present invention provides an optical laminate that has a protective layer on only one side of the linear polarizer, while suppressing the disappearance of dichroic dye from the linear polarizer in high-temperature and high-humidity environments, and improving visibility (interference unevenness and air bubble inclusion). [Solution] The optical laminate comprises a first protective layer, a linear polarizer, a first adhesive layer, and a phase difference layer laminate in this order. The first adhesive layer is a cured layer of a curable composition containing a cationic polymerizable compound. The phase difference layer laminate comprises a first liquid crystal phase difference layer, a second adhesive layer having a thickness of 20 to 200 nm, and a second liquid crystal phase difference layer, in this order from the first adhesive layer side.

Description

[Technical Field]

[0001] This invention relates to an optical laminate. [Background technology]

[0002] Conventionally, OLEDs have used circular polarizers with multiple liquid crystal phase difference layers to prevent external light reflection, and in response to the demand for thinner designs, circular polarizers with a protective layer for the linear polarizer on only one side (the viewing side) are also known. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-046029 [Patent Document 2] Japanese Patent Publication No. 2023-068424 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, when a protective layer is applied to only one side of a linear polarizer, exposure to high temperature and high humidity conditions can cause dichroic dyes such as iodine to be lost from the linear polarizer, or interference irregularities to occur, resulting in insufficient visibility.

[0005] The present invention has been made in view of the above problems, and aims to provide an optical laminate that has a protective layer on only one side of the linear polarizer, while suppressing the disappearance of the dichroic dye from the linear polarizer in high temperature and high humidity environments, and improving visibility (interference unevenness and air bubble inclusion). [Means for solving the problem]

[0006] [1] An optical laminate comprising a first protective layer, a linear polarizer, a first adhesive layer, and a phase difference layer laminate in this order, wherein the first adhesive layer is a cured layer of a curable composition containing a cationic polymerizable compound, and the phase difference layer laminate comprises a first liquid crystal phase difference layer, a second adhesive layer having a thickness of 20 to 200 nm, and a second liquid crystal phase difference layer in this order from the first adhesive layer side. [2] The optical laminate according to [1], wherein the thickness of the first adhesive layer is 0.5 to 3.0 μm. [3] The optical laminate according to [1] or [2], wherein the curable composition of the first adhesive layer contains 20 to 80 parts by mass of an alicyclic epoxy compound when the total amount of cationic polymerizable compound is 100 parts by mass. [4] The optical laminate according to any one of [1] to [3], wherein the cationic polymerizable compound of the curable composition of the first adhesive layer contains an oxetane compound. [5] The optical laminate according to any one of [1] to [4], wherein the second adhesive layer is a water-based adhesive layer. [6] The optical laminate according to any one of [1] to [5], wherein the thickness of the second adhesive layer is 30 to 120 nm. [7] The optical laminate according to any one of [1] to [6], wherein the peeling force between the first liquid crystal phase difference layer and the second liquid crystal phase difference layer is 0.20 N / 25 mm or more. [8] When the in-plane phase difference value of the phase difference layer laminate with respect to light of wavelength λnm is Re(λ), the optical laminate according to any one of [1] to [7] satisfies the following relationship between equations (1) and (2). 80nm ≤ Re(450) ≤ 130nm (1) Re(450) / Re(550)≦1.00 (2) [Effects of the Invention]

[0007] According to the present invention, an optical laminate is provided that can suppress the disappearance of dichroic dye from a linear polarizer and has improved visibility (interference unevenness and bubble inclusion). [Brief explanation of the drawing]

[0008] [Figure 1]Figure 1 is a schematic cross-sectional view showing one embodiment of a phase difference layer laminate 300 and an optical laminate 400 according to one embodiment. [Modes for carrying out the invention]

[0009] (Optical laminate (circular polarizer) 400) As shown in Figure 1, the optical laminate 400 according to this embodiment comprises a first protective layer 180, a linear polarizer 220, a first adhesive layer 150, and a phase difference 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 rays such as natural light. Examples of linear polarizers include films (hereinafter also called "polarizers") that are uniaxially stretched while impregnated with dichroic dyes such as iodine or organic dichroic dyes in a polymer such as PVA, and optically anisotropic layers (hereinafter also called "polarizing films") that are formed by aligning dichroic dyes and polymerizable liquid crystal compounds.

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

[0012] The luminous efficiency correction polarization degree Py of a linear polarizer is usually 80% or higher, preferably 90% or higher, more preferably 95% or higher, even more preferably 98% or higher, particularly preferably 99% or higher, and may even be 99.9% or higher. Increasing the luminous efficiency correction polarization degree Py of a linear polarizer is advantageous in enhancing the anti-reflective function of the optical laminate. If the luminous efficiency correction polarization degree Py is less than 80%, the anti-reflective function may not be achieved when used as an anti-reflective film.

[0013] The luminous efficiency correction single transmittance Ty of a linear polarizer improves clarity when displaying white as it increases. However, as can be seen from the relationship between (Equation 1) and (Equation 2), there is a problem that the polarization degree decreases if the single transmittance is too high. Therefore, it is preferable that it is between 30% and 60%, more preferably between 35% and 55%, even more preferably between 38% and 50%, even more preferably between 40% and 45%, and most preferably between 41% and 43%. If the luminous efficiency correction single transmittance Ty is excessively high, the luminous efficiency correction polarization degree Py becomes too low, which may result in insufficient anti-reflective function when used as an anti-reflective film.

[0014] <Polarizer> A film produced by uniaxially stretching a polymer such as polyvinyl alcohol resin film (PVA) impregnated with dichroic dyes such as iodine or organic dichroic dyes can typically be manufactured by following these steps: uniaxial stretching of the polyvinyl alcohol resin film; a step of dyeing the polyvinyl alcohol resin film with a dichroic dye such as iodine to adsorb the dichroic dye; a step of treating the polyvinyl alcohol resin film on which the dichroic dye has been adsorbed with a crosslinking agent such as a boric acid aqueous solution; and a step of washing with water after 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] Uniaxial stretching of polyvinyl alcohol-based resin films can be performed before, simultaneously with, or after dyeing with dichroic dyes. When uniaxial stretching is performed after dyeing, it may be performed before or during boric acid treatment. Of course, uniaxial stretching can also be performed in multiple stages as shown here. Uniaxial stretching methods include stretching uniaxially in the film transport direction between rolls with different peripheral speeds, stretching uniaxially in the film transport direction using a heated roll, or stretching in the width direction using a tenter. Uniaxial stretching may also be performed by dry stretching in the atmosphere, or by wet stretching using a solvent such as water to swell the polyvinyl alcohol-based resin film before stretching. The stretching ratio is usually around 3 to 8 times. Alternatively, an aqueous solution containing polyvinyl alcohol may be applied to a thermoplastic resin film, followed by a drying treatment, and then stretched together with the thermoplastic resin film using the above method.

[0017] Dyeing of polyvinyl alcohol-based resin films with dichroic dyes can be carried out, for example, by immersing the polyvinyl alcohol-based resin film in an aqueous solution containing a dichroic dye. Specifically, iodine or dichroic organic dyes can be used as dichroic dyes. It is preferable to immerse the polyvinyl alcohol-based resin film in water to swell it before the dyeing treatment.

[0018] When iodine is used as a dichroic dye, a method of dyeing is usually employed in which a polyvinyl alcohol-based resin film is immersed in an aqueous solution containing iodine and potassium iodide. 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 (dyeing time) in this aqueous solution is usually about 20 to 1,800 seconds.

[0019] On the other hand, when using a dichroic organic dye as the dichroic pigment, a method is usually employed in which a polyvinyl alcohol-based resin film is immersed in an aqueous solution containing a water-soluble dichroic organic dye. 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 dye aqueous solution may also contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the dichroic organic dye aqueous solution used for dyeing is usually about 20 to 80°C. The immersion time (dyeing time) in this aqueous solution 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 boric acid content 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, it is preferable that the boric acid-containing aqueous solution contains potassium iodide. The potassium iodide content 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] Polyvinyl alcohol-based resin films treated with boric acid are typically washed with water. This washing can be performed, for example, by immersing the boric acid-treated polyvinyl alcohol-based resin film in water. The water temperature during washing is usually around 5 to 40°C, and the immersion time is usually around 1 to 120 seconds.

[0022] After washing with water, the polarizer is dried to obtain a polarizer. The drying process can be carried out using a hot air dryer or a far-infrared heater. The drying temperature is usually around 30 to 100°C, preferably 50 to 80°C. The drying time is usually around 60 to 600 seconds, preferably 120 to 600 seconds. The drying process reduces the moisture content in the polarizer to a practical level. The moisture content is usually around 5 to 20% by mass of the total mass of the polarizer, preferably 8 to 15% by mass. If the moisture content is 5% by mass or more, the polarizer has sufficient flexibility, thus preventing damage or breakage after drying. If the moisture content is 20% by mass or less, the polarizer has sufficient thermal stability.

[0023] As described above, a polarizer can be manufactured in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film.

[0024] <Polarizing film> An optically anisotropic layer consisting of a polarizing film, i.e., a polymer of a polymerizable liquid crystal compound containing a dichroic dye, can be suitably used in flexible display applications, for example, because its hue can be arbitrarily controlled, it can be made significantly thinner, and it is non-shrinkable due to the absence of thermal stretching relaxation.

[0025] A polarizing film is formed by applying a polarizing film-forming composition to an alignment film formed on a substrate as needed, and then orienting the dichroic dye contained in the polarizing film-forming composition. The polarizing film is a film with 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 obtained, and if the film thickness is thicker than this range, the orientation-regulating force of the alignment film decreases, and orientation defects tend to occur. The polarizing film-forming composition may further contain a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, and an adhesion improver.

[0026] In an optically anisotropic layer in which a dichroic dye and a polymerizable liquid crystal compound are horizontally oriented with respect to the substrate surface, the ratio (dichroic ratio) of the absorbance A1(λ) in the orientation direction to the absorbance A2(λ) in the direction perpendicular to the orientation plane with respect to light of wavelength λnm is preferably 7 or higher, more preferably 20 or higher, and even more preferably 40 or higher. The higher this value, the better the absorption selectivity of the polarizer. Depending on the type of dichroic dye, in the case of a liquid crystal cured film cured in the nematic liquid crystal phase state, it is about 5 to 10.

[0027] By mixing two or more dichroic dyes with different absorption wavelengths, polarizing films of various hues can be created, resulting in polarizing films that absorb across the entire visible light spectrum. Such polarizing films with specific absorption characteristics can be applied to a wide range of uses.

[0028] <Polarizing film; polymerizable liquid crystal compound> A polymerizable liquid crystal compound is a compound that has polymerizable groups and liquid crystalline properties (hereinafter also referred to as polymerizable liquid crystal). A polymerizable group is a group that participates in polymerization reactions, and it is preferable that it be a photopolymerizable group. Here, a photopolymerizable group is a group that can participate in polymerization reactions by active radicals or acids generated from photopolymerization initiators, which will be described later. Examples of polymerizable groups include vinyl groups, vinyloxy groups, 1-chlorovinyl groups, isopropenyl groups, 4-vinylphenyl groups, acryloyloxy groups, methacryloyloxy groups, oxyranyl groups, and oxetanyl groups. Among these, acryloyloxy groups, methacryloyloxy groups, vinyloxy groups, oxyranyl groups, and oxetanyl groups are preferred, and methacryloyloxy groups or acryloyloxy groups are more preferred. The liquid crystalline properties may be thermotropic liquid crystal or lyotropic liquid crystal, but when mixed with dichroic dyes, which will be described later, thermotropic liquid crystal is preferred. A polymerizable liquid crystal compound may be a monomer or a polymer obtained by polymerizing dimers or more.

[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 being able to exhibit high dichroism, the liquid crystal state exhibited by the polymerizable liquid crystal compound is preferably a smectic phase, and from the viewpoint of performance improvement, a higher-order smectic phase is more preferable. Among these, higher-order smectic liquid crystal compounds that form smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase, or smectic L phase are more preferable, and higher-order smectic liquid crystal compounds that form smectic B phase, smectic F phase, or smectic I phase are even more preferable. 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 manufactured. Furthermore, polarizing films with such high polarization performance yield Bragg peaks originating from higher-order structures such as the hexatic phase and crystalline phase in X-ray diffraction measurements. These Bragg peaks originate from the periodic structure of molecular orientation, and films with a periodic interval of 3 to 6 Å can be obtained. From the viewpoint of obtaining even higher polarization characteristics, it is preferable that the polarizing film of the present invention contains a polymer of polymerizable liquid crystal in which the polymerizable liquid crystal is oriented in the smectic phase.

[0030] As the polymerizable liquid crystal compound, one type may be used alone, or two or more types may be used in combination. The polymerizable liquid crystal composition containing other compounds, as 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. However, from the viewpoint of obtaining a polarizing film with a high degree of orientation order, the ratio 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 polymerizable liquid crystal compound content in the polarizing film-forming composition of the present invention is preferably 40 to 99.9% by mass, more preferably 60 to 99% by mass, and even more preferably 70 to 99% by mass, relative to the solid content of the polymerizable liquid crystal composition. When the polymerizable liquid crystal compound content is within the above range, the orientation of the polymerizable liquid crystal compound tends to be high. In this specification, solid content refers to the total amount of components excluding the solvent from the polymerizable liquid crystal composition.

[0032] <Polarizing film; dichroic dye> Dichroic dyes are dyes that have different absorbances along the long axis and short axis of the molecule. 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 stilbenazo dyes, with bisazo dyes and trisazo dyes being preferred. Dichroic dyes may be used individually or in combination, but to obtain absorption across the entire visible light range, it is preferable to combine two or more dichroic dyes, and more preferably to combine three or more dichroic dyes.

[0033] Examples of azo dyes include the compound represented by formula (I) (hereinafter sometimes referred to as "compound (I)"). T1-A1(-N=N-A2)pN=N-A3-T2(I) [In formula (I), A1, A2, and A3 independently represent an optionally substituted 1,4-phenylene group, an optionally substituted naphthalene-1,4-diyl group, an optionally substituted phenyl benzoate group, an optionally substituted 4,4'-stilbenylene group, or an optionally substituted divalent heterocyclic group, where T1 and T2 are electron-withdrawing or electron-emitting groups located substantially 180° to the azo bond plane. p represents an integer from 0 to 4. When p is 2 or greater, each A2 may be identical or different from the others. The -N=N- bond may be replaced by -C=C-, -COO-, -NHCO-, or -N=CH- bond in the range showing absorption in the visible region.]

[0034] The content of dichroic dyes (total amount if multiple types are included) is typically 1 to 60 parts by mass, preferably 1 to 40 parts by mass, and more preferably 1 to 20 parts by mass, per 100 parts by mass of polymerizable liquid crystal compound, from the viewpoint of obtaining good light absorption characteristics. If the content of dichroic dyes is less than this range, light absorption will be insufficient and sufficient polarization performance cannot be obtained, and if it is more than this range, it may inhibit the orientation of liquid crystal molecules.

[0035] (1st protective layer 180) The first protective layer 180 has the function of protecting the visible surface of the linear polarizer 220, which is opposite to the phase difference layer laminate 300. The first protective layer 180 is laminated onto the linear polarizer 220 via an adhesive layer or bonding agent layer as needed. Alternatively, the first protective layer 180 may be directly laminated to the linear polarizer 220. Here, "directly laminated" includes a configuration in which the first protective layer is laminated to the linear polarizer by its self-adhesion. To improve adhesion with the linear polarizer, the first protective layer may be surface-treated (e.g., corona treatment, etc.), and a thin layer such as a primer layer (also called an easy-adhesion layer) may be formed on it. There are no particular limitations on the materials of the adhesive layer and tack layer that may be interposed between the first protective layer 180 and the linear polarizer 220. Examples of adhesives include cured products of curable compositions containing cationic polymerizable compounds, which will be described in detail in the section on the first adhesive layer 150 below, and water-based adhesives, which will be described in detail in the section on the second adhesive layer 40. Other examples of adhesives include cured products of curable compositions containing radical polymerizable compounds. Examples of tacks include acrylic tacks, urethane tacks, and silicone tacks.

[0036] As the first protective layer, for example, a resin film with excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and stretchability can be used. The resin film may also be a thermoplastic resin film. Specific examples of such resins include cellulosic resins such as triacetylcellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone resins; polysulfone resins; polycarbonate resins; polyamide resins such as nylon and aromatic polyamides; polyimide resins; polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; cyclic polyolefin resins having cyclo and norbornene structures (also called norbornene resins); (meth)acrylic resins such as polymethyl methacrylate; polyarylate resins; polystyrene resins; polyvinyl alcohol resins; and mixtures thereof. Protective films of such materials are readily available on the market. In this specification, (meth)acrylic means either acrylic or methacrylic.

[0037] 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.

[0038] The thermoplastic resin film may be subjected to surface treatments such as hard coating, anti-reflective coating, anti-sticking coating, and anti-glare coating, as needed. Furthermore, the thermoplastic resin film may be subjected to treatments to improve visibility when viewed through polarized sunglasses (typically, by providing (elliptical) polarization functionality or providing ultra-high phase difference), as needed. By applying such treatments, excellent visibility can be achieved even when viewing the display screen through polarized lenses such as polarized sunglasses. Therefore, polarizing plates with a phase difference layer can be suitably applied to image display devices that may be used outdoors.

[0039] A thermoplastic resin film can be produced by stretching a film containing the above-mentioned thermoplastic resin. Stretching methods include uniaxial stretching and biaxial stretching. Stretching directions include the machine flow direction (MD) of the unstretched film, a direction perpendicular to it (TD), and a direction oblique to the machine flow direction (MD). Biaxial stretching may be simultaneous biaxial stretching, where the film is stretched in two directions simultaneously, or sequential biaxial stretching, where the film is stretched in one direction first, and then in another. Stretching can be performed, for example, by using two or more nip rolls with a high peripheral speed on the exit side to stretch the film longitudinally (machine flow direction: MD), or by gripping both ends of the unstretched film with chucks and spreading it in a direction perpendicular to the machine flow direction (TD). In this process, the phase difference value and wavelength dispersion can be controlled by adjusting the film thickness or the stretching ratio. Furthermore, the wavelength dispersion value can be controlled by adding a wavelength dispersion modifier to the resin.

[0040] The above thermoplastic resin film may contain any suitable additives depending on the purpose. Examples of additives include: antioxidants such as hindered phenol, phosphorus, and sulfur-based antioxidants; stabilizers such as light stabilizers, ultraviolet absorbers, weather stabilizers, and heat stabilizers; reinforcing materials such as glass fibers and carbon fibers; 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 phase difference reducing agents. The types, combinations, and amounts of additives contained can be appropriately set according to the purpose and desired properties.

[0041] Furthermore, a coating layer (surface treatment layer) can be provided on the outer surface of the thermoplastic resin film to impart desired surface optical properties or other characteristics. Specific examples of surface treatment layers include hard coat layers, anti-glare layers, anti-reflective layers, anti-static layers, and anti-fouling layers. 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 side of the thermoplastic resin film or on both sides.

[0042] [Hard coat layer] The hard coat layer has the function of increasing the surface hardness of the thermoplastic resin film and is provided for purposes such as preventing surface scratches. Preferably, the hard coat layer has a pencil hardness of H or a harder value as measured by the pencil hardness test specified in JIS K 5600-5-4:1999 "General test methods for paints - Part 5: Mechanical properties of coatings - Section 4: Scratch hardness (pencil method)" (measured by placing an optical film with a hard coat layer on a glass plate).

[0043] The materials used to form the hard coat layer generally harden with heat or light. Examples include organic hard coat materials such as organic silicones, melamines, epoxys, (meth)acrylics, and urethane (meth)acrylates, and inorganic hard coat materials such as silicon dioxide. Among these, urethane (meth)acrylate or polyfunctional (meth)acrylate hard coat materials are preferred because they have good adhesion to thermoplastic resin films and excellent productivity. In this specification, (meth)acrylate means either acrylate or methacrylate.

[0044] The hard coat layer may contain various fillers as desired, for the purpose of adjusting the refractive index, improving the flexural modulus, stabilizing the volume shrinkage rate, and further improving heat resistance, antistatic properties, anti-glare properties, etc. The hard coat layer may also contain additives such as antioxidants, UV absorbers, light stabilizers, antistatic agents, leveling agents, and defoamers.

[0045] The hard coat layer may contain additives to further improve its strength. The additives are not limited to inorganic fine particles, organic fine particles, or mixtures thereof. While a thicker hard coat layer is preferable for hardness, if it is too thick, it becomes 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.

[0046] The anti-glare layer is a layer having a fine uneven surface, and is preferably formed using the hard coat material described above.

[0047] An anti-glare layer having a fine uneven surface can be formed by: 1) forming a coating film containing fine particles on a stretched film to create an uneven surface based on those fine particles; or 2) forming a coating film containing or not containing fine particles on a stretched film, and then pressing it against a mold (such as a roll) with an uneven surface to transfer the uneven shape (also known as the embossing method).

[0048] An anti-reflective layer is a layer that reduces the reflection of ambient light from the surface of a thermoplastic resin film for those observing the film, and typically has a reflectivity of 1.5% or less for visible light. Such an anti-reflective layer 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 or materials described in Japanese Patent Application Publication No. 2021-6929. By adjusting the refractive indices and the thickness of each layer, the reflected light from each layer can be weakened by each other, resulting in an excellent anti-reflective function.

[0049] As will be described in detail later, it is preferable to manufacture an anti-reflective layer consisting of a high refractive index layer and a low refractive index layer using a coating composition capable of forming both the high refractive index layer and the low refractive index layer, as this process is extremely simple. Here is an example of a coating composition capable of forming both the high refractive index layer and the low refractive index layer. Such a coating composition is liquid and contains a suitable 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, for example, obtained by dissolving a curable resin such as urethane acrylate and a photopolymerization initiator (photopolymerization initiator) such as acetophenone, benzophenone, benzyldimethylketal, α-hydroxyalkylphenone, α-aminoalkylphenone, or thioxanthone 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 included. Furthermore, as a coating-type composition capable of forming a low refractive index layer (composition for forming a low refractive index layer), silica particles are dispersed in a solution obtained by dissolving a photopolymerization initiator (photopolymerization initiator) such as acetophenone-based, benzophenone-based, benzyldimethylketal-based, α-hydroxyalkylphenone-based, α-aminoalkylphenone-based, or thioxanthone-based in a solvent such as 1-methoxy-2-propyl acetate or methyl isobutyl in a binder resin such as polyethylene glycol diacrylate or pentaerythritol (tri / tetra)acrylate as a curable resin. To further improve coatability, a fluorine-based leveling agent may be included. Note that the coating-type compositions capable of forming high refractive index layers and low refractive index layers listed here are merely examples, and it is preferable to optimize the high refractive index layer-forming composition and the low refractive index layer-forming composition, respectively, according to the characteristics of the anti-reflective layer to be formed.

[0050] The anti-reflective layer may, for example, include a low refractive index layer. Alternatively, it may be a multilayer structure further comprising a high refractive index layer and / or a medium refractive index layer between the thermoplastic resin film and the low refractive index layer.

[0051] A low refractive index layer can be formed by applying a coating solution containing a light-transmitting resin such as a cured product of the aforementioned curable resin or 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.

[0052] An antistatic layer is provided on the surface of a thermoplastic resin film to impart conductivity and suppress the effects of static electricity. For example, to form the antistatic layer, a method can be employed in which a resin composition containing a conductive substance (antistatic agent) is applied to the thermoplastic resin film. For instance, by including an antistatic agent in the hard coat material used to form the hard coat layer described above, an antistatic hard coat layer can be formed.

[0053] The antifouling layer is provided to impart water repellency, oil repellency, sweat resistance, and antifouling properties. A suitable material for forming the antifouling layer is a fluorine-containing organic compound. Examples of fluorine-containing organic compounds include fluorocarbons, perfluorosilanes, and polymer compounds thereof. Depending on the material to be formed, methods such as physical vapor deposition (typically vapor deposition and sputtering), chemical vapor deposition, and wet coating can be used for forming the antifouling layer. The average thickness of the antifouling layer is usually about 1 to 50 nm, preferably 3 to 35 nm.

[0054] If the first protective layer is a thermoplastic resin layer or a resin layer such as the cured resin layer described later, the linear polarizer and the first protective layer may be in direct contact without an adhesive layer or bonding agent in between.

[0055] For example, a thermoplastic resin layer as a first protective layer can be laminated onto a linear polarizer by applying a composition containing a thermoplastic resin onto a support substrate, drying it as necessary, and bonding the resulting thermoplastic resin layer with the support substrate to a linear polarizer via an adhesive layer or bonding agent as necessary, and then peeling off the support substrate (first method). For example, if the first protective layer is a thermoplastic resin layer, it is also possible to form the thermoplastic resin layer by directly applying the above composition to the surface of the linear polarizer and drying it as necessary. In this case, the linear polarizer and the first protective layer are in direct contact without an adhesive layer or bonding agent (second method). However, if 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.

[0056] The first 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 curing resins, such as (meth)acrylic resins, epoxy resins, oxetane resins, urethane resins, (meth)acrylic urethane resins, and melamine resins. A cured resin layer containing a cured product of a curable resin can be formed by applying a composition containing a curable resin onto a support substrate, drying it as necessary, and then applying heat or irradiating it with active energy rays such as visible light, ultraviolet light, infrared light, X-rays, alpha rays, beta rays, gamma rays, and electron beams. The resulting cured resin layer with a support substrate can be laminated onto a linear polarizer as the first protective layer by bonding the support substrate to a linear polarizer via an adhesive layer as necessary, and then peeling off the support substrate.

[0057] (First adhesive layer 150) The first adhesive layer 150 is bonded to the linear polarizer 220 and the first liquid crystal phase difference layer 30. The first adhesive layer 150 is in direct contact with the linear polarizer 220, or, if the linear polarizer 220 has an alignment film on the side facing the first liquid crystal phase difference layer 30, it is in direct contact with the alignment film of the linear polarizer 220. Therefore, no layer such as the thermoplastic resin film exemplified in the section on the first protective layer 180 is interposed between the linear polarizer 220 and the first liquid crystal phase difference layer 30.

[0058] The first adhesive layer 150 is in direct contact with the first liquid crystal phase difference layer 30, or, if the first liquid crystal phase difference layer 30 has an alignment film on the side facing the linear polarizer 220, it is in direct contact with the alignment film of the first liquid crystal phase difference layer 30. Therefore, no layer such as the thermoplastic resin film exemplified in the section on the first protective layer 180 is interposed between the first adhesive layer 150 and the first liquid crystal phase difference layer 30.

[0059] The thickness of the first adhesive layer 150 may be 0.5 to 5.0 μm, preferably 0.6 to 4.0 μm, more preferably 0.7 to 3.0 μm, and even more preferably 0.8 to 2.0 μm. The thickness of the first adhesive layer 150 may also be 0.5 to 3.0 μm. The lower limit of the thickness of the first adhesive layer may be 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.0 μm, 1.1 μm, or 1.2 μm, and the upper limit of the thickness of the first adhesive layer may be 3.0 μm, 2.5 μm, 2.0 μm, 1.8 μm, 1.6 μm, or 1.5 μm.

[0060] In this embodiment, where the thickness of the second adhesive layer is thin, such as 200 nm or less, interference unevenness is suppressed compared to a normal optical laminate, so the thickness of the first adhesive layer greatly affects the visibility of the optical laminate. As described above, when the thickness of the first adhesive layer is made thin to 3.0 μm or less, an optical laminate with even more suppressed interference unevenness can be obtained.

[0061] As in this embodiment, an optical laminate with a thin second adhesive layer of 200 nm or less and a protective layer on only one side is prone to wrinkles due to curing shrinkage of the adhesive. However, if the thickness of the first adhesive layer is as thin as 3.0 μm or less, a clean optical laminate with suppressed wrinkles can be obtained.

[0062] (Materials for the first adhesive layer) The first adhesive layer is a cured layer of a curable composition containing a cationic polymerizable compound. As in this embodiment, an optical laminate with a thin overall thickness, where the second adhesive layer is less than 200 nm thick and has a protective layer on only one side, is prone to wrinkles due to curing shrinkage of the adhesive. However, when cured using a curable composition containing a cationic polymerizable compound, the curing reaction is slow, resulting in an optical laminate with suppressed wrinkles.

[0063] (Curable composition) The curable composition contains a cationic polymerizable compound.

[0064] (Cationic polymerizable compounds) Cationic polymerizable compounds are compounds or oligomers that undergo a cationic polymerization reaction and harden upon irradiation with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays, or upon heating. Specific examples include epoxy compounds, oxetane compounds, and vinyl compounds.

[0065] (Epoxy compound) Epoxy compounds are compounds having one or more epoxy groups, and examples include alicyclic epoxy compounds, aliphatic epoxy compounds, and aromatic epoxy compounds.

[0066] (Alicyclic epoxy compound) An alicyclic epoxy compound is a compound having one or more alicyclic epoxy groups. In this specification, an alicyclic epoxy group refers to a functional group A having an aliphatic ring and a three-membered ring (oxirane ring) formed by two adjacent carbon atoms and an oxygen atom forming the aliphatic ring. Functional group A is (CH2) of the compound of formula (a) below. m It may be a mixture from which one of the hydrogen atoms has been removed. m is an integer between 2 and 5, preferably m is 4. [ka]

[0067] (a) In equation (CH2)m Any hydrogen atom therein may be substituted with a linear alkyl group such as a methyl group or an ethyl group (which may have 6 or fewer carbon atoms).

[0068] If the alicyclic epoxy compound contains at least one functional group A in the molecule, it does not prevent the epoxy compound having a structure other than the alicyclic epoxy group from containing one or more epoxy groups in the same molecule. An example of the functional group A is a 3,4-epoxycyclohexyl group. The alicyclic epoxy compound may have an aromatic ring, but it is preferred that it does not have an aromatic ring.

[0069] The alicyclic epoxy compound may be a monofunctional alicyclic epoxy compound having only one functional group A, but it is preferred that it is a polyfunctional alicyclic epoxy compound containing two or more functional groups A. The alicyclic epoxy compound may further have an epoxy group other than the alicyclic epoxy group.

[0070] Specific examples of the alicyclic epoxy compound include 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 1,2-epoxy-4-vinylcyclohexane, 1,2-epoxy-1-methyl-4-(1-methylepoxyethyl)cyclohexane, 3,4-epoxycyclohexylmethyl methacrylate, 4-(1,2-epoxyethyl)-1,2-epoxycyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, ethylenebis(3,4-epoxycyclohexanecarboxylate), oxydiethylenebis(3,4-epoxycyclohexanecarboxylate), 1,4-cyclohexanedimethylbis(3,4-epoxycyclohexanecarboxylate), and 3-(3,4-epoxycyclohexylmethoxycarbonyl)propyl 3,4-epoxycyclohexanecarboxylate, etc.

[0071] Among the alicyclic epoxy compounds, 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate is preferably used because it has appropriate curability and can be obtained relatively inexpensively. As the alicyclic epoxy compound, one type of alicyclic epoxy compound may be used alone, or a combination of several different types may be used.

[0072] (Aliphatic epoxy compounds) An aliphatic epoxy compound is a compound in which one of the two carbon atoms in an epoxy group is bonded to a carbon atom that makes up another aliphatic hydrocarbon chain. The aliphatic hydrocarbon chain may have an ether bond or an ester bond. Furthermore, aliphatic epoxy compounds that contain alicyclic epoxy compounds, i.e., functional group A which is the alicyclic epoxy group mentioned above, are excluded from the list of aliphatic epoxy compounds. Aliphatic epoxy compounds may have aromatic rings, but it is preferable that they do not have aromatic rings. The aliphatic epoxy compound may be a monofunctional aliphatic epoxy compound having only one of the epoxy groups described above, but it is preferable that it be a polyfunctional aliphatic epoxy compound containing two or more of the epoxy groups described above.

[0073] Examples of monofunctional aliphatic epoxy compounds include glycidyl ethers of aliphatic alcohols and glycidyl esters of alkyl carboxylic acids. Specific examples include allyl glycidyl ether, butyl glycidyl ether, sec-butylphenyl glycidyl ether, 2-ethylhexyl glycidyl ether, mixed alkyl glycidyl ethers with 12 and 13 carbon atoms, glycidyl ethers of alcohols, monoglycidyl ethers of aliphatic higher alcohols, and glycidyl esters of higher fatty acids. Monofunctional aliphatic epoxy compounds may be used individually or in combination with multiple different compounds.

[0074] Polyfunctional aliphatic epoxy compounds have two or more of the above epoxy groups. An example of a polyfunctional aliphatic epoxy compound is an aliphatic diepoxy compound represented by the following formula (b). [ka]

[0075] In formula (b), Z is an alkylene group having 1 to 9 carbon atoms, an alkylidene group having 3 or 4 carbon atoms, a divalent alicyclic hydrocarbon group, or formula -C m H 2m -Z1-C n H 2n It is a divalent group represented by -. Also, the above formula -C m H 2m -Z1-C n H 2n -Z1- is -O-, -CO-O-, -O-CO-, -SO2-, -SO-, or CO-, m and n each independently represent an integer of 1 or greater, and the sum of m and n is 9 or less.

[0076] The divalent alicyclic hydrocarbon group may be, for example, a divalent alicyclic hydrocarbon group having 4 to 8 carbon atoms, such as the divalent group shown in the following formula (b-1).

[0077] [ka]

[0078] Specific examples of compounds represented by formula (b) include, for example, diglycidyl ethers of alkanediols, diglycidyl ethers of oligoalkylene glycols with up to 4 repeats, or diglycidyl ethers of alicyclic diols.

[0079] Examples of diols (glycols) that can form the compound represented by formula (b) include ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, and 2-methyl-2,4-pentanediol. Examples include alkanediols such as 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, and 1,9-nonanediol; oligoalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, and dipropylene glycol; and alicyclic diols such as cyclohexanediol and cyclohexanedimethanol.

[0080] From the viewpoint of obtaining a first-active-energy-ray-curable composition with low viscosity and easy application, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and neopentyl glycol diglycidyl ether are preferred. As the aliphatic epoxy compound, one type of aliphatic epoxy compound may be used alone, or a combination of several different types may be used.

[0081] Polyfunctional aliphatic epoxy compounds may also have functional group B in which the epoxy group is bonded to the alicyclic ring by a single bond, and an example of such a compound is the compound shown in the following formula. [ka] In formula (II), R' is the group obtained by subtracting p -OH groups from a p-valent alcohol, and p and n are natural numbers. Examples of p-valent alcohols [R'-(OH)p] include polyhydric alcohols such as 2,2-bis(hydroxymethyl)-1-butanol (alcohols with 1 to 15 carbon atoms). p is preferably 1 to 6, and n is preferably 1 to 30. When p is 1, n is 2 or more, and when p is 2 or more, the n in each group in parentheses may be the same or different. Specific examples of the above compound include the 1,2-epoxy-4-(2-oxyranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (trade name "EHPE3150", manufactured by Daicel Corporation).

[0082] (Aromatic epoxy compounds) An aromatic epoxy compound refers to a compound in which a glycidyl ether group or a glycidyl ester group is directly bonded to an aromatic ring. An aromatic epoxy compound may be a monofunctional aromatic epoxy having one epoxy group, or a polyfunctional aromatic epoxy having two or more epoxy groups. However, as used herein, aromatic epoxy compounds exclude compounds having functional group A, which is an alicyclic epoxy group, within the molecule.

[0083] Examples of monofunctional aromatic epoxy include monoglycidyl ethers of monovalent phenols such as phenol, cresol, and butylphenol, or bisphenol derivatives such as bisphenol A and bisphenol F, or alkylene oxide adducts thereof; epoxy novolac resins; monoglycidyl ethers of aromatic compounds having two or more phenolic hydroxyl groups, such as resorcinol, hydroquinone, and catechol; monoglycidyl ethers of aromatic compounds having two or more alcoholic hydroxyl groups, such as benzenedimethanol, benzenediethanol, and benzenedibutanol; monoglycidyl esters of polybasic acid aromatic compounds having two or more carboxyl groups, such as phthalic acid, terephthalic acid, and trimellitic acid; and monoglycidyl esters of benzoic acid, toluic acid, naphthoic acid, etc.

[0084] Monofunctional aromatic epoxy can be commercially available, such as "EX-142," "EX-146," "EX-147," and "EX-121" (all manufactured by Nagase ChemteX Corporation).

[0085] Specific examples of polyfunctional aromatic epoxy include polyglycidyl ethers of naphthalene or naphthalene derivatives (also referred to as "naphthalene-type epoxy compounds"); polyglycidyl ethers of bisphenol derivatives such as bisphenol A and bisphenol F (also referred to as "bisphenol A-type epoxy compounds" and "bisphenol F-type epoxy compounds"); epoxy novolac resins; polyglycidyl ethers of aromatic compounds having two or more phenolic hydroxyl groups, such as resorcinol, hydroquinone, and catechol; polyglycidyl ethers of aromatic compounds having two or more alcoholic hydroxyl groups, such as benzenedimethanol, benzenediethanol, and benzenedibutanol; polyglycidyl esters of polybasic acid aromatic compounds having two or more carboxyl groups, such as phthalic acid, terephthalic acid, and trimellitic acid; glycidyl esters of benzoic acid, polyglycidyl esters of toluic acid and naphthoic acid, etc.; styrene oxides such as styrene oxide, alkylated styrene oxide, and vinylnaphthalene epoxidants, or diepoxyds of divinylbenzene, etc. As a polyfunctional aromatic epoxy compound, one compound may be used alone, or a combination of several different compounds may be used.

[0086] Polyfunctional aromatic epoxy can be commercially available, for example, “Denacol EX-201”, “Denacol EX-711”, and “Denacol EX-721” (all manufactured by Nagase ChemteX Corporation); “Ogusol EG-280”, and “Ogusol CG-400” (both manufactured by Osaka Gas Chemical Co., Ltd.); “EXA-80CRP”, and “HP4032D” (both manufactured by DIC Corporation); “jER828”, and “jER82 Examples include "8EL" (all manufactured by Mitsubishi Chemical Corporation); "Adeka Resin EP-4100", "Adeka Resin EP-4100G", "Adeka Resin EP-4100E", "Adeka Resin EP-4100L", "Adeka Resin EP-4100TX", "Adeka Resin EP-4000", "Adeka Resin EP-4005", "Adeka Resin EP-4901", and "Adeka Resin EP-4901E" (all manufactured by ADEKA Corporation).

[0087] (Oxetane compounds) An oxetane compound is a compound having an oxetanyl group, and may be an aliphatic compound, an alicyclic compound, or an aromatic compound. In this specification, an oxetane compound is defined as a compound that does not have an oxirane ring (epoxy group). The oxetane compound may be a monofunctional oxetane compound having only one oxetanyl group, or a polyfunctional oxetane compound having two or more oxetanyl groups. The oxetane compound is preferably a polyfunctional oxetane compound, and more preferably a bifunctional oxetane compound having two oxetanyl groups.

[0088] Oxetane compounds include, specifically, 3,7-bis(3-oxetanyl)-5-oxa-nonane, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, 1,2-bis[(3-ethyl-3-oxetanylmethoxy)methyl]ethane, 1,3-bis[(3-ethyl-3-oxetanylmethoxy)methyl]propane, ethylene glycol bis(3-ethyl-3-oxetanylmethyl) ether, triethylene glycol bis(3-ethyl-3-oxetanylmethyl) ether, and tetraethylene glycol bis(3-ethyl-3-oxetanylmethyl) This includes ethyl(3-ethyl-3-oxetanylmethoxy)butane, 1,6-bis(3-ethyl-3-oxetanylmethoxy)hexane, 3-ethyl-3-(phenoxy)methyloxetane, 3-ethyl-3-(cyclohexyloxymethyl)oxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(chloromethyl)oxetane, 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, xylylenebisoxetane, etc. As for the oxetane compound, one type of oxetane compound may be used alone, or a combination of several different types may be used. Preferably, it is at least one selected from the group consisting of 3-ethyl-3-hydroxymethyl oxetane, xylylene bisoxetane, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3{[(3-ethyloxetane-3-yl)methoxy]methyl}oxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, and 3-ethyl-3-(cyclohexyloxymethyl)oxetane.

[0089] (Composition of cationic polymerizable compounds) The cationic polymerizable compound preferably contains an alicyclic epoxy compound. The cationic polymerizable compound preferably contains 10 parts by mass or more of an alicyclic epoxy compound, based on 100 parts by mass of the total amount of the cationic polymerizable compound, and may contain 20 parts by mass or more, 25 parts by mass or more, or 30 parts by mass or more. There is no particular upper limit to the amount of alicyclic epoxy compound in the cationic polymerizable compound, but it may be 90 parts by mass or less, 80 parts by mass or less, 70 parts by mass or less, 60 parts by mass or less, or 50 parts by mass or less.

[0090] The cationic polymerizable compound preferably contains 10 parts by mass or more of a polyfunctional alicyclic epoxy compound, based on 100 parts by mass of the total amount of the cationic polymerizable compound, and may contain 20 parts by mass or more, 25 parts by mass or more, or 30 parts by mass or more. There is no particular upper limit to the amount of polyfunctional alicyclic epoxy compound in the cationic polymerizable compound, but it may be 90 parts by mass or less, 80 parts by mass or less, 70 parts by mass or less, 60 parts by mass or less, or 50 parts by mass or less.

[0091] The inclusion of alicyclic epoxy compounds in cationic polymerizable compounds increases the crosslinking density, which tends to further reduce the loss of dichroic dyes such as iodine under high-temperature and high-humidity environments. Furthermore, if the amount of alicyclic epoxy compound is too large, it can actually cause a reaction with dichroic dyes such as iodine.

[0092] The cationic polymerizable compound preferably contains an oxetane compound. The cationic polymerizable compound preferably contains 10 parts by mass or more of the oxetane compound, with the total mass of the cationic polymerizable compound being 100 parts by mass, but may also contain 20 parts by mass or more, 30 parts by mass or more, 40 parts by mass or more, 45 parts by mass or more, or 50 parts by mass or more. There is no particular upper limit to the content of the oxetane compound in the cationic polymerizable compound, but may be 90 parts by mass or less, 85 parts by mass or less, 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, 60 parts by mass or less, or 50 parts by mass or less.

[0093] The cationic polymerizable compound preferably contains 10 parts by mass or more of a polyfunctional oxetane compound, with the total mass of the cationic polymerizable compound being 100 parts by mass, and may also contain 20 parts by mass or more, 30 parts by mass or more, 40 parts by mass or more, 45 parts by mass or more, or 50 parts by mass or more. There is no particular upper limit to the content of the polyfunctional oxetane compound in the cationic polymerizable compound, but it may be 90 parts by mass or less, 85 parts by mass or less, 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, 60 parts by mass or less, or 50 parts by mass or less.

[0094] The inclusion of oxetane compounds in cationic polymerizable compounds increases the crosslinking density, which tends to further reduce the loss of dichroic dyes such as iodine under high temperature and high humidity conditions.

[0095] The cationic polymerizable compound may also preferably contain alicyclic epoxy compounds and oxetane compounds.

[0096] (Cationic polymerization initiator) The curable composition preferably contains a cationic polymerization initiator in addition to the cationic polymerizable compound. The cationic polymerization initiator may be a thermal cationic polymerization initiator or a photocatalytic cationic polymerization initiator. Photocationic polymerization initiators generate cationic species or Lewis acids upon irradiation with active energy rays such as visible light, ultraviolet light, X-rays, and electron beams, thereby initiating the polymerization reaction of cationic polymerizable compounds. Because photocationic polymerization initiators act catalytically with light, they exhibit excellent storage stability and workability even when mixed with cationic polymerizable compounds. Examples of compounds that can be used as photocationic polymerization initiators and generate cationic species or Lewis acids upon irradiation with active energy rays include aromatic diazonium salts; onium salts such as aromatic iodonium salts and aromatic sulfonium salts; and iron-arene complexes. Preferably, the photocationic polymerization initiator is at least one ionic compound selected from the group consisting of aromatic sulfonium salts and aromatic iodonium salts.

[0097] Examples of aromatic diazonium salts include benzenediazonium hexafluoroantimonate, benzenediazonium hexafluorophosphate, and benzenediazonium hexafluoroborate.

[0098] Examples of aromatic iodonium salts include diphenyliodonium tetrakis(pentafluorophenyl)borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, and di(4-nonylphenyl)iodonium hexafluorophosphate.

[0099] Examples of aromatic sulfonium salts include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, 4,4'-bis[diphenylsulfonio]diphenylsulfidebishexafluorophosphate, 4,4'-bis[di(β-hydroxyethoxy)phenylsulfonio]diphenylsulfidebishexafluoroantimonate, 4,4'-bis[di(β-hydroxyethoxy)phenylsulfonio]diphenylsulfidebishexafluorophosphate, and 7-[di(p-toluyl)sulfone] Examples include nio-2-isopropylthioxanthone hexafluoroantimonate, 7-[di(p-toluyl)sulfonio]-2-isopropylthioxanthone tetrakis(pentafluorophenyl)borate, 4-phenylcarbonyl-4'-diphenylsulfonio-diphenylsulfide hexafluorophosphate, 4-(ptert-butylphenylcarbonyl)-4'-diphenylsulfonio-diphenylsulfide hexafluoroantimonate, and 4-(p-tert-butylphenylcarbonyl)-4'-di(p-toluyl)sulfonio-diphenylsulfide tetrakis(pentafluorophenyl)borate.

[0100] Examples of iron-arene complexes include xylene-cyclopentadienyl iron(II) hexafluoroantimonate, cumene-cyclopentadienyl iron(II) hexafluorophosphate, and xylene-cyclopentadienyl iron(II) tris(trifluoromethylsulfonyl) methanide.

[0101] The photocationic polymerization initiator may be used alone or in combination of two or more. Among the above, aromatic sulfonium salts are particularly preferred because they have ultraviolet absorption properties even in the wavelength region around 300 nm, resulting in excellent curability and allowing for the production of an adhesive cured layer with good mechanical strength and adhesive strength.

[0102] (Other ingredients) The curable composition may optionally contain additives such as ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, defoamers, antistatic agents, leveling agents, solvents, and photosensitizers.

[0103] (Composition of curable composition) In a curable composition, the cationic polymerizable compound may be present in an amount of 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more, based on the total solid content of the curable composition.

[0104] In the curable composition, 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 included.

[0105] (Method of bonding by curing of a curable composition) Bonding of two adhesive layers by curing a curable composition can be performed by coating at least one of the bonding surfaces selected from each of the two bonding surfaces with the curable composition coating, overlapping the two layers with the coating layer of the curable composition in between, pressing from above and below using a bonding roll or the like, and then curing the curable composition by irradiating it with active energy rays, or curing the adhesive composition by heating it. Before forming the coating layer of the curable composition, at least one of the bonding surfaces selected from each of the two layers may be subjected to an easy-adhesion treatment such as saponification, corona treatment, plasma treatment, primer treatment, or anchor coating treatment. Various coating methods can be used to form the coating layer of the curable composition, including die coaters, comma coaters, gravure coaters, wire bar coaters, and doctor blade coaters.

[0106] The light irradiation intensity when irradiating with active energy rays is not particularly limited, but is 10 mW / cm². 2 More than 1,000mW / cm 2 The following is preferable: The irradiation intensity is preferably in the wavelength range effective for activating the photocationic polymerization initiator. The light is irradiated once or multiple times at such an irradiation intensity, and the accumulated light dose is 10 mJ / cm². 2 Preferably, it should be 100 mJ / cm² or higher. 2 More than 1,000mJ / cm 2 The following is more preferable.

[0107] The light source used for polymerization curing of the curable 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] (Phase difference layered laminate 300) The phase difference layer laminate 300 has, in order from the linear polarizer 220 side, a first liquid crystal phase difference layer 30, a second adhesive layer 40, and a second liquid crystal phase difference layer 50.

[0109] (First liquid crystal phase difference layer 30 and second liquid crystal phase difference layer 50) The liquid crystal phase difference layer is a cured layer of oriented polymerizable liquid crystal compounds, which exhibits a phase difference.

[0110] The liquid crystal phase difference layer is not limited to any layer that generates a phase difference in any direction. It may be a phase difference layer that generates a phase difference in the plane, such as a positive A plate and a negative A plate, or a layer that generates a phase difference in the thickness direction, such as a positive C plate and a negative C plate. Furthermore, the positive A and negative A plates may each be λ / 4 plates or λ / 2 plates. In addition, the liquid crystal phase difference layer may be tilt-oriented or form a cholesteric-oriented state.

[0111] The first liquid crystal phase difference layer 30 and the second liquid crystal phase difference layer 50 may each be a single-layer liquid crystal phase difference layer or a laminate of multiple liquid crystal phase difference layers. Preferably, the angle θ between the slow phase axis of the first liquid crystal phase difference 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 the reflection of ambient light by the metal electrodes when the optical laminate is used in an OLED display device.

[0112] Each liquid crystal phase difference layer may be positive wavelength dispersive or negative wavelength dispersive.

[0113] When the in-plane phase difference value of the phase difference layer laminate 300 with respect to light of wavelength λnm is Re(λ), it is preferable that the following relationships (1) and (2) are satisfied. 80nm ≤ Re(450) ≤ 130nm (1) Re(450) / Re(550)≦1.00 (2) [In equations (1) and (2), Re(450) represents the in-plane phase difference value in nm for light with a wavelength of 450 nm. Re(550) represents the in-plane phase difference value in nm for light with a wavelength of 550 nm.

[0114] In this invention, the in-plane phase difference value of the phase difference layer laminate 300 is measured as a value measured in the state of the optical laminate 400. If the first protective layer 180 included in the optical laminate 400 has a phase difference, it is necessary to cancel out that phase difference value and measure the value in the optical laminate 400 to obtain the in-plane phase difference value of the phase difference layer laminate 300. The above in-plane phase difference value can be measured using an in-plane phase difference measuring device such as the KOBRA-WR manufactured by Oji Instruments Co., Ltd.

[0115] The transmittance of the phase difference layer laminate 300 at 311 nm is preferably 8% or higher.

[0116] A liquid crystal phase difference layer is typically formed by applying a liquid crystal phase difference layer-forming composition containing a polymerizable liquid crystal compound onto an alignment film formed on a substrate, and then polymerizing and curing the polymerizable liquid crystal compound in an oriented state.

[0117] The thickness of the liquid crystal phase difference layer is typically 10 μm or less, preferably 5 μm or less, and more preferably 0.3 μm to 3 μm.

[0118] To achieve a high level of anti-reflective properties, it is preferable that the liquid crystal phase difference layer has a λ / 4 plate function (i.e., a π / 2 phase difference function) across the entire visible light spectrum. Specifically, an inverse wavelength-dispersive λ / 4 layer is preferred, or a combination of two or more liquid crystal phase difference layers with different orientations is preferred. For example, a combination of a liquid crystal phase difference layer having a λ / 2 plate function (i.e., a π phase difference function) and a liquid crystal phase difference layer having a λ / 4 plate function (i.e., a π / 2 phase difference function) may be used.

[0119] Furthermore, from the viewpoint of compensating for the anti-reflective 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 phase difference layer may have an optical anisotropy layer that is tilt-oriented or may form a cholesteric-oriented state.

[0120] (Combination of the first liquid crystal phase difference layer and the second liquid crystal phase difference layer) The first and second liquid crystal phase difference layers may be the same liquid crystal phase difference layer, or they may be different types of combinations.

[0121] For example, one of the first liquid crystal phase difference layer and the second liquid crystal phase difference layer may be an inverse wavelength dispersion λ / 4 plate, and the other of the first liquid crystal phase difference layer and the second liquid crystal phase difference layer may be a positive C plate.

[0122] Furthermore, one of the first liquid crystal phase difference layer and the second liquid crystal phase difference layer may be a positive wavelength dispersive λ / 2 plate, and the other of the first liquid crystal phase difference layer and the second liquid crystal phase difference layer may be a positive wavelength dispersive λ / 4 plate.

[0123] Below, we will describe, as an example of a liquid crystal phase difference layer, a laminate of inverse wavelength dispersion λ / 4 plate, positive wavelength dispersion λ / 4 plate, and positive wavelength dispersion λ / 2 plate, as well as a positive C plate.

[0124] (Reverse wavelength dispersion λ / 4 plate (R)) The inverse wavelength dispersion λ / 4 plate preferably satisfies the optical properties shown in the following equations (R1) and (R2), where Re(λ) is the in-plane phase difference with respect to light of wavelength λnm across the entire visible light spectrum, and it is preferable that it satisfies the optical properties shown in the following equations (R1), (R2), and (R3).

[0125] 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 phase difference value (in nm) for light with a wavelength of 450 nm, Re(550) represents the in-plane phase difference value (in nm) for light with a wavelength of 550 nm, and Re(650) represents the in-plane phase difference value (in nm) for light with a wavelength of 650 nm.) When the "Re(450) / Re(550)" ratio of the liquid crystal phase difference layer exceeds 1.0, the light loss on the short-wavelength side increases in the elliptic polarizer equipped with the liquid crystal phase difference layer. Preferably, it is 0.7 to 1.0, more preferably 0.80 to 0.95, even more preferably 0.80 to 0.92, and particularly preferably 0.82 to 0.88.

[0126] The "Re(450) / Re(550)" value can be arbitrarily adjusted by adjusting the mixing ratio of polymerizable liquid crystal compounds, as well as the stacking angles and phase difference values ​​of multiple optical anisotropic layers.

[0127] The in-plane phase difference value of the liquid crystal phase difference layer can be adjusted by the thickness of the liquid crystal phase difference layer. Since the in-plane phase difference value is determined by the following formula (4), to obtain a desired in-plane phase difference value (Re(λ)), it is necessary to adjust Δn(λ) and the film thickness d. The thickness of the liquid crystal phase difference layer is preferably 0.5 μm to 5 μm, and more preferably 1 μm to 3 μm. The thickness of the liquid crystal phase difference layer can be measured by an interferometer, laser microscope, or stylus-type film thickness gauge. Note that Δn(λ) depends on the molecular structure of the polymerizable liquid crystal compound, which will be described later.

[0128] Re(λ) = d × Δn(λ) …(4) (In the formula, Re(λ) represents the in-plane phase difference value (nm) at wavelength λnm, d represents the film thickness, and Δn(λ) represents the birefringence at wavelength λnm.)

[0129] A liquid crystal phase difference layer is typically formed by applying a liquid crystal phase difference layer forming composition to an alignment film formed on a substrate, and polymerizing the polymerizable liquid crystal compounds contained in the liquid crystal phase difference layer composition in an oriented state. The liquid crystal phase difference layer forming composition may further contain a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, and an adhesion improver.

[0130] <Polymerizable liquid crystal compound for forming inverse wavelength dispersion λ / 4 plates> Polymerizable liquid crystal compounds refer to liquid crystal compounds having polymerizable groups, particularly photopolymerizable groups. Conventionally known polymerizable liquid crystal compounds can be used as polymerizable liquid crystal compounds for forming inverse wavelength dispersion λ / 4 plates. A photopolymerizable group is a group that can participate in the polymerization reaction by reaction-active species generated from a photopolymerization initiator, such as active radicals or acids. Examples of photopolymerizable groups include vinyl groups, vinyloxy groups, 1-chlorovinyl groups, isopropenyl groups, 4-vinylphenyl groups, acryloyloxy groups, methacryloyloxy groups, oxyranyl groups, and oxetanyl groups. Among these, acryloyloxy groups, methacryloyloxy groups, vinyloxy groups, oxyranyl groups, and oxetanyl groups are preferred, with acryloyloxy groups being more preferred. The liquid crystal properties can be either thermotropic or lyotropic, but thermotropic liquid crystals are preferred because they allow for precise control of film thickness. Furthermore, the phase order structure in thermotropic liquid crystals can be either nematic or smectic. Furthermore, the liquid crystal may be in the form of a rod or a disc. The polymerizable liquid crystal compound can be used alone or in combination of two or more types.

[0131] As polymerizable liquid crystal compounds, liquid crystals having a T-shaped or H-shaped mesogenic structure with further birefringence in the direction perpendicular to the long axis of the molecule are preferred from the viewpoint of exhibiting inverse wavelength dispersion, and T-shaped liquid crystals are more preferred from the viewpoint of obtaining stronger dispersion. Specifically, the structure of a T-shaped liquid crystal is, for example, the following formula (I):

[0132] [ka] Examples of compounds represented by [the formula shown] are given.

[0133] In formula (I), Ar represents a divalent aromatic group which may have substituents. Preferably, the divalent aromatic group contains at least one of a nitrogen atom, an oxygen atom, or a sulfur atom. If the divalent group Ar contains two or more aromatic groups, the two or more aromatic groups may be linked to each other by single bonds, divalent bonding groups such as -CO-O-, and -O-.

[0134] G 1 and G 2 Each of these independently represents a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atoms contained in the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with halogen atoms, C1-C4 alkyl groups, C1-C4 fluoroalkyl groups, C1-C4 alkoxy groups, cyano groups, or nitro groups, and the carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with oxygen atoms, sulfur atoms, or nitrogen atoms.

[0135] L 1 , L 2 、 B 1 and B 2 Each of these is independently a single bond or a divalent linking group.

[0136] k and l each represent integers from 0 to 3 independently, satisfying the relationship 1 ≤ k + l. Here, if 2 ≤ k + l, then B 1 and B 2 , G 1 and G 2 These elements may be identical to each other, or they may be different.

[0137] E 1 and E 2 Each of these independently represents an alkanediyl group having 1 to 17 carbon atoms, where the hydrogen atoms in the alkanediyl group may be substituted with halogen atoms, and the -CH2- groups in the alkanediyl group may be substituted with -O-, -S-, or -COO-, and if there are multiple -O-, -S-, or -COO- groups, they are not adjacent to each other. 1 and P 2 Each of these independently represents a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.

[0138] G 1 and G 2Each of these is independently preferably a 1,4-phenylenediyl group which may be substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, or a 1,4-cyclohexanediyl group which may be substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, more preferably a methyl-substituted 1,4-phenylenediyl 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-cyclohexandiyl group.

[0139] Also, there are multiple G 1 and G 2 Preferably, at least one of them is a divalent alicyclic hydrocarbon group, and L 1 or L 2 G that joins 1 and G 2 It is more preferable that at least one of these is a divalent alicyclic hydrocarbon group.

[0140] L 1 and L 2 Each of these is independently, preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a1 Ure a2 -, -R a3 COOR a4 -, -R a5 OCOR a6 -, -R a7 OC=OOR a8 -, -N=N-, -CR c =CR d -, or -C≡C-. Here, R a1 ~R a8 Each of these independently represents a single bond or an alkylene group with 1 to 4 carbon atoms, R c and R d L represents an alkyl group with 1 to 4 carbon atoms or a hydrogen atom. 1 and L 2 Each is independently, more preferably a single bond, -OR a2-1-, -CH2-, -CH2CH2-, -COOR a4-1 -, or -OCOR a6-1 -. Here, R a2-1 , R a4-1 , R a6-1 each independently represents a single bond, -CH2-, or -CH2CH2-. L 1 and L 2 each independently is more preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, or -OCO-.

[0141] B 1 and B 2 each independently is 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 -. Here, R a9 ~R a16 each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms. B 1 and B 2 each independently is more preferably a single bond, -OR a10-1 -, -CH2-, -CH2CH2-, -COOR a12-1 -, or -OCOR a14-1 -. Here, R a10-1 , R a12-1 , R a14-1 each independently represents a single bond, -CH2-, or -CH2CH2-. B 1 and B 2 each independently is even more preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, -OCO-, or -OCOCH2CH2-.

[0142] From the viewpoint of exhibiting inverse wavelength dispersion, it is preferable that 2 ≦ k + l ≦ 6, more preferably k + l = 4, and even more preferably k = 2 and l = 2. When k = 2 and l = 2, it is preferable because it has a symmetric structure.

[0143] E 1 and E 2 are each independently preferably an alkanediyl group having 1 to 17 carbon atoms, and more preferably an alkanediyl group having 4 to 12 carbon atoms.

[0144] P 1 or P 2 Examples of the polymerizable group represented by 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 them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferable, and an acryloyloxy group is more preferable.

[0145] 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, an anthracene ring, etc., and a benzene ring and a naphthalene ring are preferable. 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 them, it is preferable to have a thiazole ring, a benzothiazole ring, or a benzofuran ring, and it is more preferable to have a benzothiazole ring. Further, when Ar contains a nitrogen atom, the nitrogen atom preferably has π electrons.

[0146] In formula (I), N is the total number of π electrons contained in the divalent aromatic group represented by Ar. π Preferably, it is 8 or more, more preferably 10 or more, even more preferably 14 or more, and particularly preferably 16 or more. Also, preferably 30 or less, more preferably 26 or less, and even more preferably 24 or less.

[0147] Examples of aromatic groups represented by Ar include the following:

[0148] [ka]

[0149] In equations (Ar-1) to (Ar-23), the asterisk (*) indicates a connecting part, Z 0 , Z 1 and Z 2 Each of these independently represents a hydrogen atom, a halogen atom, a C1-C12 alkyl group, a cyano group, a nitro group, a C1-C12 alkylsulfinyl group, a C1-C12 alkylsulfonyl group, a carboxyl group, a C1-C12 fluoroalkyl group, a C1-C6 alkoxy group, a C1-C12 alkylthio group, a C1-C12 N-alkylamino group, a C2-C12 N,N-dialkylamino group, a C1-C12 N-alkylsulfamoyl group, or a C2-C12 N,N-dialkylsulfamoyl group.

[0150] Q 1 , and Q 2 Each of these is independently of -CR 2’ R 3’ -, -S-, -NH-, -NR 2’ - represents -CO- or -O-, R 2’ and R 3’ Each of these independently represents either a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0151] J 1 , and J 2 Each of these independently represents either a carbon atom or a nitrogen atom.

[0152] Y 1 , and Y 2 Each of these independently represents an optionally substituted aromatic hydrocarbon group or an aromatic heterocyclic group.

[0153] W 1 and W 2 Each of these independently represents a hydrogen atom, a cyano group, a methyl group, or a halogen atom, and m represents an integer from 0 to 6.

[0154] Y 1 , and Y 2 Examples of aromatic hydrocarbon groups in this context include C6-C20 aromatic hydrocarbon groups such as phenyl, naphthyl, anthuryl, phenanthuryl, and biphenyl groups, with phenyl and naphthyl groups being preferred and phenyl groups being more preferred. Examples of aromatic heterocyclic groups include C4-C20 aromatic heterocyclic groups containing at least one heteroatom such as a nitrogen atom, oxygen atom, or sulfur atom, such as furyl, pyrrolyl, thienyl, pyridinyl, thiazolyl, and benzothiazolyl groups, with furyl, thienyl, pyridinyl, thiazolyl, and benzothiazolyl groups being preferred.

[0155] Y 1 , and Y 2 Each of these may independently be a substituted polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group. A polycyclic aromatic hydrocarbon group refers to a fused polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. A polycyclic aromatic heterocyclic group refers to a fused polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

[0156] Z 0 , Z 1 and Z 2 Each of these is preferably independently a hydrogen atom, a halogen atom, a C1-C12 alkyl group, a cyano group, a nitro group, or a C1-C12 alkoxy group, Z 0 A hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and a cyano group are more preferably Z 1 and Z 2 Hydrogen atoms, fluorine atoms, chlorine atoms, methyl groups, and cyano groups are more preferred.

[0157] Q 1 , and Q 2 -NH-, -S-, -NR 2’ -, -O- is preferred, R 2’ A hydrogen atom is preferred. Among these, -S-, -O-, and -NH- are particularly preferred.

[0158] Among formulas (Ar-1) to (Ar-23), formulas (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability.

[0159] In equations (Ar-16) to (Ar-23), Y 1 This is the nitrogen atom and Z to which it is bonded. 0 It may also form an aromatic heterocyclic group. Examples of aromatic heterocyclic groups that Ar may have include those mentioned above, such as a pyrrole ring, imidazole ring, pyrroline ring, pyridine ring, pyrazine ring, pyrimidine ring, indole ring, quinoline ring, isoquinoline ring, purine ring, pyrrolidine ring, etc. This aromatic heterocyclic group may have substituents. Also, Y 1 This is the nitrogen atom and Z to which it is bonded. 0 In addition, the aforementioned substituted polycyclic aromatic hydrocarbon groups or polycyclic aromatic heterocyclic groups may also be used. Examples include benzofuran rings, benzothiazole rings, and benzoxazole rings.

[0160] Among polymerizable liquid crystal compounds, compounds with a maximum absorption wavelength of 300-400 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 proceed during long-term storage. However, if the maximum absorption wavelength of the polymerizable liquid crystal compound is 300-400 nm, even if 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 by these reactive species can be effectively suppressed. Therefore, this is advantageous in terms of the long-term stability of the polymerizable liquid crystal composition and can improve the orientation and uniformity of the film thickness of the resulting liquid crystal cured film. The maximum absorption wavelength of the polymerizable liquid crystal compound can be measured using an ultraviolet-visible spectrophotometer in a solvent. The solvent is a solvent that can dissolve the polymerizable liquid crystal compound, and examples include chloroform.

[0161] 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, per 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 orientation of the resulting liquid crystal cured 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.

[0162] [Laminate containing positive wavelength dispersive λ / 2 plate and positive wavelength dispersive λ / 4 plate] One method for achieving anti-reflective properties is to use a laminate combining a positive wavelength-dispersive λ / 2 plate and a positive wavelength-dispersive λ / 4 plate. For example, one example of a laminate is obtained by combining a layer having optical properties represented by equations (QL1), (QL3), and (QL4) with a layer having optical properties represented by equations (QL2), (QL3), and (QL4) in a specific slow axis relationship.

[0163] 100nm <Re(550)<160nm (QL1) 200nm <Re(550)<320nm (QL2) Re(450) / Re(550)≧1.00 (QL3) 1.00 ≥ Re(650) / Re(550) (QL4)

[0164] Well-known methods for combining the above configurations can be found in Japanese Patent Publication No. 2015-163935 and WO2013 / 137464. From the viewpoint of viewing angle compensation, it is preferable to use a λ / 2 layer containing a polymer of a disc-shaped polymerizable liquid crystal compound and a λ / 4 layer containing a polymer of a rod-shaped polymerizable liquid crystal compound.

[0165] With respect to the transmission axis of the linear polarizer, the slow axis of the positive wavelength dispersive λ / 2 layer is, for example, 10° to 20°, preferably 12° to 18°, and more preferably about 15°, and the slow axis of the positive wavelength dispersive λ / 4 layer is, for example, 70° or more and 80° or less, more preferably 72° or more and 78° or less, and even more preferably about 75°. In another embodiment, with respect to the transmission axis of the linear polarizer, the slow axis of the positive wavelength-dispersive λ / 2 layer is, for example, -10° to -20°, preferably -12° to -18°, more preferably about -15°, and the slow axis of the positive wavelength-dispersive λ / 4 layer is, for example, -70° to -80°, more preferably -72° to -78°, and even more preferably about -75°. In yet another embodiment, with respect to the transmission axis of the linear polarizer, the slow axis of the positive wavelength dispersive λ / 2 layer is 70° to 80°, preferably 72° to 78°, more preferably about 75°, and the slow axis of the positive wavelength dispersive λ / 4 layer is, for example, 10° to 20°, more preferably 12° to 18°, and even more preferably about 15°. In yet another embodiment, with respect to the transmission axis of the linear polarizer, the slow axis of the positive wavelength dispersive λ / 2 layer is -70° to -80°, preferably -72° to -78°, more preferably about -75°, and the slow axis of the positive wavelength dispersive λ / 4 layer is, for example, -10° to -20°, more preferably -12° to -18°, and even more preferably about -15°.

[0166] Examples of disc-shaped polymerizable liquid crystal compounds include compounds containing a group represented by formula (W) (hereinafter sometimes referred to as polymerizable liquid crystal compound (C)). [ka] [In formula (W), R 40 This represents the following equations (W-1) to (W-5).

[0167] [ka]

[0168] X 40 and Z 40 m2 represents an alkanediyl group having 1 to 12 carbon atoms, and the hydrogen atoms in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, or the hydrogen atoms in the alkoxy group may be substituted with a halogen atom. Furthermore, the -CH2- constituting the alkanediyl group may be replaced with -O- or -CO-. Also, m2 is an integer from 1 to 20.

[0169] Examples of rod-shaped polymerizable liquid crystal compounds include those represented by formulas (I), (II), (III), (IV), (V), or (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. The hydrogen atoms in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group may be substituted with halogen atoms, C1-C6 alkyl groups, C1-C6 alkoxy groups, cyano groups, or nitro groups, and the hydrogen atoms in the C1-C6 alkyl groups and the C1-C6 alkoxy groups may be substituted with fluorine atoms.

[0170] B11 is -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR 16 -, -NR 16 -CO-, -CO-, -CS-, or single bond. 16 This represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0171] B12 and B13 are independently -C≡C-, -CH=CH-, -CH2-CH2-, -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)-, -OC(=O)-O-, -CH=N-, -N=CH-, -N=N-, -C(=O)-NR 16 -, -NR 16 -C(=O)-, -OCH2-, -OCF2-, -CH2O-, -CF2O-, -CH=CH-C(=O)-O-, -OC(=O)-CH=CH-, or a single bond.

[0172] E11 represents an alkanediyl group having 1 to 12 carbon atoms. The hydrogen atoms in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and the hydrogen atoms in the alkoxy group may be substituted with a halogen atom. Furthermore, the -CH2- group constituting the alkanediyl group may be replaced with -O- or -CO-.

[0173] 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. As A11, cyclohexane-1,4-diyl group and 1,4-phenylene group are preferred.

[0174] As E11, a linear alkanediyl group having 1 to 12 carbon atoms is preferred. The -CH2- group constituting the alkanediyl group may be replaced with -O-.

[0175] Specifically, examples include linear alkanediyl groups having 1 to 12 carbon atoms, such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, and dodecane-1,12-diyl group; and -CH2-CH2-O-CH2-CH2-, -CH2-CH2-O-CH2-CH2-O-CH2-CH2-, and -CH2-CH2-O-CH2-CH2-O-CH2-CH2-.

[0176] For B11, -O-, -S-, -CO-O-, and -O-CO- are preferred, with -CO-O- being the most preferred among them.

[0177] For B12 and B13, independently, -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)-, and -OC(=O)-O- are preferred, with -O- or -OC(=O)-O- being more preferred.

[0178] As for the polymerizable group represented by P11, radical polymerizable groups or cationic polymerizable groups are preferred in terms of high polymerization reactivity, particularly photopolymerization reactivity, and are easy to handle, as well as the liquid crystal compound itself is easy to manufacture. Therefore, the polymerizable group is preferably a group represented by the following formulas (P-11) to (P-15).

[0179] [ka] [In formulas (P-11) to (P-15), R 17 ~R 21 Each of these independently represents an alkyl group or hydrogen atom having 1 to 6 carbon atoms.

[0180] Specific examples of the groups represented by equations (P-11) to (P-15) include the groups represented by equations (P-16) to (P-20) below.

[0181] [ka]

[0182] P11 is preferably a group represented by formulas (P-14) to (P-20), and more preferably a vinyl group, a p-stilbene group, an epoxy group, or an oxetanyl group.

[0183] It is even more preferable that the group represented by P11-B11- is an acryloyloxy group or a methacryloyloxy group.

[0184] (In the formula, A12 to A14 are each independently synonymous with A11, B14 to B16 are each independently synonymous with B12, B17 is synonymous with B11, and E12 is synonymous with 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 hydroxyl group, a methylol group, a formyl group, a sulfo group (-SO3H), a carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and the alkyl group and alkoxy group are composed of -CH 2 - may be replaced with -O-.

[0185] [Other configurations] The first and second liquid crystal phase difference layers may be laminates in which at least one liquid crystal phase difference layer is tilt-oriented or cholesterically oriented, in addition to the above-mentioned configuration of a combination of a positive wavelength dispersive λ / 2 layer and a positive wavelength dispersive λ / 4 layer. Examples of well-known configurations include those described in WO2021 / 060378, WO2021 / 132616, and WO2021 / 132624.

[0186] <Positive C-plate> Positive C plates are not particularly limited as long as they have anisotropy in the thickness direction, but if they are not tilt-oriented or cholesteric-oriented, they have optical properties represented by equation (PC3). nx≒ny <nz (PC3)

[0187] The in-plane phase difference value Re(550) of the positive C plate at a wavelength of 550 nm is typically in the range of 0 to 10 nm, preferably in the range of 0 to 5 nm. Furthermore, the phase difference value Rth(550) in the thickness direction at a wavelength of 550 nm is typically in the range of -170 nm to -10 nm, preferably in the range of -150 nm to -20 nm, and more preferably in the range of -100 nm to -40 nm. If the phase difference value in the thickness direction is within this range, the anti-reflection characteristics from oblique directions can be further improved.

[0188] The thickness of the positive C plate is usually 10 μm or less, preferably 5 μm or less, and more preferably 0.3 μm to 3 μm.

[0189] The positive C plate is preferably a coating layer formed by polymerizing one or more polymerizable liquid crystal compounds. More preferably, it is a rod-shaped polymerizable liquid crystal compound.

[0190] Examples of rod-shaped polymerizable liquid crystals include compounds represented by formulas (I), (II), (III), (IV), (V), or (VI). P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I) P11 - B11 - E11 - B12 - A11 - B1 - 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 are each independently synonymous with A11, B14 to B16 are each independently synonymous with B12, B17 is synonymous with B11, E12 is synonymous with 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 (-SO3H), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms or a halogen atom, and -CH2- constituting the alkyl group and the alkoxy group may be replaced by -O-.)

[0191] 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 still more preferably 90 to 95 parts by mass with respect 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 from the viewpoint of the alignment property of the obtained liquid crystal retardation layer. In addition, in this specification, the solid content of the composition for forming a liquid crystal retardation layer means all components obtained by removing volatile components such as organic solvents from the polymerizable liquid crystal composition.

[0192] <Composition for forming a liquid crystal retardation layer>[[]] ​The liquid crystal retardation layer is usually formed by applying a composition for forming a liquid crystal retardation layer 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.

[0193] [Alignment Film and Composition for Forming Alignment Film] The alignment film has an alignment regulating force that aligns the polymerizable liquid crystal compound in a desired direction.

[0194] The alignment film facilitates the liquid crystal alignment of the polymerizable liquid crystal compound. The states of liquid crystal alignment such as horizontal alignment, vertical alignment, hybrid alignment, and tilted alignment change depending on the properties of the alignment film and the polymerizable liquid crystal compound, and the combination can be arbitrarily selected. For example, if the alignment film is a material that exhibits horizontal alignment as the alignment regulating force, the polymerizable liquid crystal compound can form a horizontal alignment or a hybrid alignment, and if it is a material that exhibits vertical alignment, the polymerizable liquid crystal compound can form a vertical alignment or a tilted alignment. Expressions such as horizontal and vertical represent the direction of the optical axis of the aligned polymerizable liquid crystal compound with respect to the plane of the optically anisotropic layer. For example, vertical alignment means having the optical axis of the aligned polymerizable liquid crystal compound in a direction perpendicular to the plane of the optically anisotropic layer. Here, the vertical means 90° ± 20° with respect to the plane of the optically anisotropic layer.

[0195] When the alignment film is formed from an alignment polymer, the alignment regulating force can be arbitrarily adjusted depending on the surface state and rubbing conditions, and when it is formed from a photoalignment polymer, it can be arbitrarily adjusted depending on the polarized light irradiation conditions, etc. Also, the liquid crystal alignment can be controlled by selecting the physical properties such as the surface tension and liquid crystallinity of the polymerizable liquid crystal compound.

[0196] 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 also has heat resistance for solvent removal and heat treatment for liquid crystal alignment. Examples of alignment films include alignment films made of aligning polymers, photo-alignment films, groove alignment films, and stretched films stretched in the orientation direction. When applied to long roll-shaped films, photo-alignment films are preferred because the orientation direction can be easily controlled.

[0197] The thickness of the orientation film is typically 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 nm to 300 nm.

[0198] Examples of oriented polymers used in rubbing orientation films include polyamides and gelatins having amide bonds in their molecules, polyimides having imide bonds in their molecules and their hydrolysates 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 oriented polymers may be used individually or in combination of two or more.

[0199] One method of rubbing involves wrapping a rubbing cloth around a rotating rubbing roll and bringing the film of the oriented polymer, formed on the surface of the substrate by applying an oriented polymer composition to the substrate and annealing it, into contact with the roll.

[0200] Photo-alignment films consist of polymers, oligomers, or monomers having photoreactive groups. An orientation-regulating force can be obtained by irradiating the photo-alignment film with polarized light. Photo-alignment films are preferable because the direction of the orientation-regulating force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light.

[0201] A photoreactive group is a group that generates liquid crystal alignment ability upon irradiation with light. Specifically, it is a group that generates a photoreaction that is the origin of liquid crystal alignment ability, such as molecular orientation induction or isomerization, dimerization, photocrosslinking, or photodegradation, upon irradiation with light. Among these photoreactive groups, those that cause dimerization or photocrosslinking are preferred in terms of their excellent orientation properties. As photoreactive groups that can generate such reactions, those having unsaturated bonds, especially double bonds, are preferred, and more preferably groups having at least one selected from the group consisting of carbon-carbon double bonds (C=C bonds), carbon-nitrogen double bonds (C=N bonds), nitrogen-nitrogen double bonds (N=N bonds), and carbon-oxygen double bonds (C=O bonds).

[0202] 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 groups and cinnamoyl groups are preferred from the viewpoint of ease of controlling reactivity and the expression of orientation-regulating power during photo-orientation. 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 those with azoxybenzene as their 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.

[0203] Polarized light can be irradiated either by directly irradiating the film surface with polarized light, or by irradiating the substrate with polarized light and allowing it to pass through. Furthermore, it is particularly preferable that the polarized light be substantially parallel. The wavelength of the irradiated polarized light should be in a wavelength range in which the photoreactive groups of the polymer or monomer having photoreactive groups can absorb light energy. Specifically, UV (ultraviolet light) in the wavelength range of 250 to 400 nm is particularly preferred. Examples of light sources used for this 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, with high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps being more preferred. These lamps are preferred because they have a high emission intensity of ultraviolet light at a wavelength of 313 nm. Polarized light can be irradiated by passing the light from the light source through a suitable polarizer. Such polarizers can include polarizing filters, polarizing prisms such as Grant-Thomson and Grant-Taylor, and wire grid type polarizers.

[0204] The alignment film forming composition may contain a leveling agent as needed. As the leveling agent, a silicone-based leveling agent and / or a fluorine-based leveling agent, as described in the section on the liquid crystal phase difference layer later, can be used. The leveling agent is usually preferably contained in the solid content of the alignment film forming composition at 0.001 to 3% by mass, more preferably 0.01 to 3% by mass, and even more preferably 0.1 to 3% by mass.

[0205] (Composition for forming liquid crystal retardation layer) The content of polymerizable liquid crystal compounds in the liquid crystal phase difference layer forming 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, per 100 parts by mass of solid content of the liquid crystal phase difference layer forming composition. A content of polymerizable liquid crystal compounds within the above range is advantageous from the viewpoint of the orientation of the resulting liquid crystal phase difference layer. In this specification, the solid content of the liquid crystal phase difference layer forming composition refers to all components of the liquid crystal phase difference layer forming composition excluding volatile components such as organic solvents.

[0206] In addition to the polymerizable liquid crystal compound, the composition for forming the liquid crystal phase difference layer may further contain reactive additives such as solvents, leveling agents, polymerization initiators, photosensitizers, polymerization inhibitors, crosslinking agents, and adhesives.

[0207] <Solvent> Compositions for forming liquid crystal phase difference layers may contain solvents. Generally, polymerizable liquid crystal compounds have high viscosity, so dissolving them in a solvent makes application easier, and as a result, it is often easier to form the liquid crystal phase difference layer. The solvent is preferably one that can completely dissolve the polymerizable liquid crystal compound, and is also preferably an inert solvent in the polymerization reaction of the polymerizable liquid crystal compound.

[0208] Examples of solvents include alcoholic 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 individually or in combination of two or more.

[0209] The solvent content is preferably 50 to 98% by mass based on the total amount of the liquid crystal retardation layer-forming composition. In other words, the solid content in the liquid crystal retardation layer-forming composition is preferably 2 to 50% by mass, more preferably 5 to 30% by mass. When the solid content is 50% by mass or less, the viscosity of the liquid crystal retardation layer-forming composition becomes low, so the thickness of the liquid crystal retardation layer becomes substantially uniform, and the liquid crystal retardation layer tends to be less likely to have unevenness. Also, such a solid content can be determined in consideration of the thickness of the optical anisotropic layer to be produced.

[0210] <Leveling agent> The liquid crystal retardation layer-forming composition may contain a leveling agent. A leveling agent is an additive having a function of adjusting the fluidity of the composition and making the film obtained by coating the composition flatter. Examples thereof include silicone-based leveling agents, acrylic-based leveling agents, and fluorine-based leveling agents. Among them, silicone-based leveling agents and fluorine-based leveling agents that are excellent in the function of reducing the surface tension of the film surface obtained by coating the composition are preferable.

[0211] Examples of the silicone-based leveling agent include leveling agents having a polyorganosiloxane skeleton.

[0212] Examples of the group bonded to the silicon atom (the silicon atom forming a siloxane bond) in the polyorganosiloxane include hydrocarbon groups. The silicone-based leveling agent may be one in which two hydrocarbon groups are bonded to the silicon atom. Although not limited to the group bonded to the silicon atom, among them, an alkyl group or an aryl group having 1 to 10 carbon atoms is preferable, more preferably a methyl group or a phenyl group, and even more preferably a methyl group. The group bonded to the above silicon atom may be only one kind or two or more kinds. Also, the number of repetitions (degree of polymerization) of the siloxane unit 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.

[0213] Commercially available silicone leveling agents can be used, such as 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 Big Chemie Japan Co., Ltd.), KF-945, KF-6015, KF-60 Examples include 20 (manufactured by Shin-Etsu Chemical Co., Ltd.), TEGORad2300, TEGORad2200N, TEGORad2011 (manufactured by Degussa), and BYK-UV3500, BYK-UV3505, BYK-3510, BYK-UV3530, BYK-UV3570, BYK-UV3575, BYK-UV3576 (all manufactured by BIC Chemie Japan Co., Ltd.), KP-422, KP-416, KP-418, KP-410, KP-411, KP-412, KP-413, KP-423, KP-414, KP-415, KP-420, KP-983 (all manufactured by Shin-Etsu Chemical Co., Ltd.), which have radical polymerizable groups such as (meth)acryloyl groups added to the polyether chain.

[0214] The content of the silicone-based leveling agent in the liquid crystal phase difference layer forming composition 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 polymerizable liquid crystal compound.

[0215] Fluorine-based leveling agents are not particularly limited, but examples include leveling agents having a fluoroaliphatic hydrocarbon skeleton. The above-mentioned fluoroaliphatic hydrocarbon skeleton is not particularly limited, but examples include fluoromethane, fluoroethane, fluoropropane, fluoroisopropane, fluorobutane, fluoroisobutane, fluorot-butane, fluoropentane, fluorohexane, and other fluoroalkanes having 1 to 10 carbon atoms. The fluoroaliphatic hydrocarbon skeleton only needs to have at least some of its hydrogen atoms replaced by fluorine atoms, but it may also be a perfluoroaliphatic hydrocarbon skeleton in which all of its hydrogen atoms are replaced by fluorine atoms.

[0216] Furthermore, the above-mentioned fluoroaliphatic hydrocarbon skeleton may form a polyfluoroalkylene ether skeleton, which is a repeating unit via ether bonds. The fluoroaliphatic hydrocarbon group used as the repeating unit is not particularly limited, but examples include fluoroC1-4 alkylene groups such as fluoromethylene, fluoroethylene, fluoropropylene, and fluoroisopropylene. The above fluoroaliphatic hydrocarbon group may be one type or two or more types. The number of repeating units (degree of polymerization) of the fluoroalkylene ether units 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.

[0217] Examples of fluorine-based leveling agents include commercially available products such as Megafac® 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 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® S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, and SA-100 (AGC Seimi Chemical Co., Ltd.); E1830, E5844 (Daikin Fine Chemical Laboratories, Inc.); and F-Top EF301, F-Top EF303, F-Top EF351, and F-Top EF352 (Mitsubishi Materials Electronic Chemicals Co., Ltd.).

[0218] The content of the fluorine-based leveling agent in the liquid crystal phase difference layer forming composition 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 polymerizable liquid crystal compound.

[0219] When the liquid crystal phase difference layer forming composition contains various leveling agents, the amount of leveling agents is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, per 100 parts by mass of polymerizable liquid crystal compound. The optical anisotropy layer forming composition may contain two or more leveling agents.

[0220] <Polymerization initiator> The liquid crystal phase difference layer forming composition may contain a polymerization initiator. The polymerization initiator is a compound capable of initiating a polymerization reaction, such as a polymerizable liquid crystal compound. As a polymerization initiator, a photopolymerization initiator that generates active radicals upon the action of light is preferred, from the viewpoint of independence from the phase state of the thermotropic liquid crystal.

[0221] Any known photopolymerization initiator can be used as the photopolymerization initiator, as long as it is a compound capable of initiating the polymerization reaction of a polymerizable liquid crystal compound. Specifically, photopolymerization initiators that can generate active radicals or acids upon the action of light are recommended, and among these, photopolymerization initiators that generate radicals upon the action of light are preferred. Photopolymerization initiators can be used alone or in combination of two or more.

[0222] As photopolymerization initiators, known photopolymerization initiators can be used. For example, as photopolymerization initiators that generate active radicals, self-cleaving benzoin compounds, acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, oxime ester compounds, acylphosphine oxide compounds, azo compounds, etc. can be used. Hydrogen abstraction types such as benzophenone compounds, alkylphenone compounds, benzoin ether compounds, benzyl ketal compounds, dibenzosverone compounds, anthraquinone compounds, xanthone compounds, thioxanthone compounds, halogenoacetophenone compounds, dialkoxyacetophenone compounds, halogenobisimidazole compounds, halogenotriazine compounds, triazine compounds, etc. can be used. As photopolymerization initiators that generate acid, iodonium salts and sulfonium salts, etc. can be used. Self-cleaving photopolymerization initiators are preferred from the viewpoint of excellent reaction efficiency at low temperatures, and acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, and oxime ester compounds are particularly preferred.

[0223] The content of the polymerization initiator in the liquid crystal phase difference layer forming composition can be appropriately adjusted depending on the type and amount of 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, per 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 orientation of the polymerizable liquid crystal compound.

[0224] <Sensitizer> The liquid crystal phase difference layer forming composition may contain a sensitizer. Photosensitizers are preferred as sensitizers. Examples of such sensitizers include xanthone compounds such as xanthones and thioxanthones (e.g., 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene compounds such as anthracene and alkoxy group-containing anthracene (e.g., dibutoxyanthracene, etc.); phenothiazines and rubrene, etc.

[0225] When a liquid crystal phase difference layer forming composition contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the liquid crystal phase difference layer forming composition can be further promoted. The amount of such 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, per 100 parts by mass of the polymerizable liquid crystal compound.

[0226] <Antioxidant> From the viewpoint of ensuring stable polymerization reactions, the liquid crystal phase difference layer forming composition may contain an antioxidant. The antioxidant allows for control over the degree of polymerization of the polymerizable liquid crystal compound.

[0227] The antioxidant may be, for example, a primary antioxidant selected from phenolic antioxidants, amine antioxidants, quinone antioxidants, and nitroso antioxidants, or a secondary antioxidant selected from phosphorus antioxidants and sulfur antioxidants.

[0228] When the liquid crystal phase difference layer forming composition contains an antioxidant, the antioxidant content 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, per 100 parts by mass of the polymerizable liquid crystal compound. The antioxidant can be used alone or in combination of two or more types. When the antioxidant content is within the above range, polymerization can be carried out without disrupting the orientation of the polymerizable liquid crystal compound.

[0229] <Reactive additives> The liquid crystal phase difference layer forming composition may contain reactive additives. Preferred reactive additives have carbon-carbon unsaturated bonds, active hydrogen reactive groups, or thiol groups within their molecules. Here, "active hydrogen reactive group" refers to a group that reacts to active hydrogen groups such as carboxyl groups (-COOH), hydroxyl groups (-OH), and amino groups (-NH2). Typical examples include glycidyl groups, oxazoline groups, carbodiimide groups, aziridine groups, imide groups, isocyanate groups, thioisocyanate groups, and maleic anhydride groups. The number of reactive groups in a reactive additive is typically 1 to 20, preferably 1 to 10.

[0230] (Second adhesive layer 40) The second adhesive layer 40 is positioned between the first liquid crystal phase difference layer 30 and the second liquid crystal phase difference layer 50, bonding them together. The second adhesive layer 40 may be in direct contact with the first liquid crystal phase difference layer 30 and / or the second liquid crystal phase difference layer 50. If at least one of the first liquid crystal phase difference layer 30 and the second liquid crystal phase difference layer 50 is formed on an alignment film, the second adhesive layer 40 may be in contact with that alignment film. The thickness of the second adhesive layer 40 is 20 to 200 nm. The thickness of the second adhesive layer may be 25 nm or more, 30 nm or more, or 35 nm or more. The thickness of the second adhesive layer 40 may be 160 nm or less, 150 nm or less, 130 nm or less, 120 nm or less, or 100 nm or less.

[0231] The material of the second adhesive layer 40 is not particularly limited and may be a cationic polymerizable adhesive or a radical polymerizable adhesive, but from the viewpoint of satisfying the thickness of the second adhesive layer 40 described above, it is preferably a water-based adhesive layer.

[0232] The second adhesive layer 40, which is a water-based adhesive layer, can be formed by drying the water-based adhesive composition. The water-based adhesive composition is an adhesive composition consisting of an aqueous solution obtained by dissolving an adhesive resin in water, and from the viewpoint of making a thin adhesive, the solid content concentration of the water-based adhesive composition is preferably 0.5 to 20% by mass, and more preferably 1% to 15% by mass. The water-based adhesive composition may contain crosslinking agents such as aldehyde compounds (glyoxal, etc.), epoxy compounds, melamine compounds, methylol compounds, isocyanate compounds, amine compounds, and polyvalent metal salts.

[0233] Examples of resins for the second adhesive 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-based resin is used as the resin for the second adhesive layer 40, the polyvinyl alcohol-based resin may be a polyvinyl alcohol resin such as partially saponified polyvinyl alcohol or fully saponified polyvinyl alcohol, or a modified polyvinyl alcohol-based resin. Examples of modified polyvinyl alcohol-based resins include carboxyl group-modified polyvinyl alcohol-based resins and acetoacetyl group-modified polyvinyl alcohol-based resins.

[0234] The average degree of polymerization of the polyvinyl alcohol-based resin (preferably acetoacetyl-modified polyvinyl alcohol-based resin) is preferably 100 to 5500, and more preferably 500 to 4500, from the viewpoint of adhesion.

[0235] The degree of saponification of polyvinyl alcohol-based resins (preferably acetoacetyl-modified polyvinyl alcohol-based resins) is typically 80 mol% to 100 mol%, and preferably 85 mol% or more.

[0236] In acetoacetyl-modified polyvinyl alcohol resins, the degree of modification (amount of modification) by acetoacetyl groups is typically 0.1 mol% to 40 mol%, and preferably 0.5 mol% to 20 mol%, from the viewpoint of adhesion.

[0237] The resin of the second adhesive layer 40 is preferably a polyvinyl alcohol-based resin, and more preferably an acetoacetyl-modified polyvinyl alcohol-based resin. In other words, the second adhesive layer 40 is preferably a dried and / or cured layer of an aqueous adhesive composition containing a polyvinyl alcohol-based resin.

[0238] To obtain a second adhesive layer of such thickness, for example, an adhesive solution such as an aqueous solution of a water-based adhesive can be applied to the surface of either the first liquid crystal phase difference layer 30 or the second liquid crystal phase difference layer 50 to form a liquid film, the other of the first liquid crystal phase difference layer 30 or the second liquid crystal phase difference layer 50 can be laminated on the liquid film, and then the solvent such as water in the liquid film can be dried by heating the laminate to form a thin second adhesive layer 40. After the drying process, ultraviolet light or electron beams can be irradiated as needed.

[0239] In this case, by diluting the concentration of the resin contained in the adhesive solution to be applied, even if a liquid film of, for example, a thickness of about 20 μm is formed, a second adhesive layer with a thickness of 20 to 200 nm can be formed.

[0240] Furthermore, since a thin first liquid crystal phase difference layer 30 and a thin second liquid crystal phase difference layer 50 makes it easier to dry the liquid film, it is preferable that the thickness of both the first liquid crystal phase difference layer 30 and the second liquid crystal phase difference layer 50 be 10 μm or less, preferably 5 μm or less, and more preferably 0.3 μm or more and 3 μm or less.

[0241] (Separation force between the first liquid crystal phase difference layer and the second liquid crystal phase difference layer) The peeling force between the first liquid crystal phase difference layer 30 and the second liquid crystal phase difference layer 50 may be 0.20 N / 25 mm or more. The peeling force may be 0.25 N / 25 mm or more, and may be 0.30 N / 25 mm or more. There is no upper limit to the peeling force, but for example, it may be 5 N / 25 mm or less.

[0242] The peeling force between the first liquid crystal phase difference layer 30 and the second liquid crystal phase difference layer 50 is the weaker of the peeling force between the second adhesive layer 40 and the first liquid crystal phase difference layer 30, and the peeling force between the second adhesive layer 40 and the second liquid crystal phase difference layer 50.

[0243] Specifically, the phase difference layer laminate is cut to a width of 25 mm, a triacetylcellulose resin (TAC) film is bonded to the first liquid crystal phase difference layer 30 of the cut phase difference layer laminate via adhesive, and a glass plate is bonded to the second liquid crystal phase difference layer 50 via adhesive. Using a precision universal testing machine, the adhesion force can be measured by gripping the phase difference layer laminate from the TAC film to the second adhesive layer 40 and measuring the force required to peel it off in a 180° direction. The measurement was performed in an environment with a peeling speed of 300 mm / min, a temperature of 23 ± 2°C, and a relative humidity of 50 ± 5%. In the peel test, peeling occurs at the weaker of the two interfaces: the interface between the first liquid crystal phase difference layer 30 and the second adhesive layer 40, and the interface between the second liquid crystal phase difference layer 50 and the second adhesive layer 40. Therefore, the peeling force at the weaker of these interfaces is measured.

[0244] In measuring peel strength, conditions not specified in this specification shall conform to the "180-degree peel test method" defined in JIS Z0237:2009 (Test methods for adhesive tapes and adhesive sheets).

[0245] (In-plane average refractive index of the first and second liquid crystal phase difference layers and the second adhesive layer) The in-plane average refractive index of the first and second liquid crystal phase difference layers may be 1.45 to 1.65, preferably 1.50 to 1.60, and more preferably 1.53 to 1.58. The in-plane average refractive index of the second adhesive layer is 1.45 to 1.60, more preferably 1.48 to 1.57, and even more preferably 1.51 to 1.54.

[0246] (outer adhesive layer) The optical laminate 400 may have an outer adhesive layer 500 on the side opposite to the second adhesive layer 40 with respect to the second liquid crystal phase difference layer 50. There are no particular limitations on the material or thickness of the outer adhesive layer 500; for example, various known adhesives such as acrylic adhesives, urethane adhesives, and silicone adhesives can be used. The thickness of the outer adhesive layer can be 1 μm or more and 100 μm or less, and preferably 5 μm or more and 50 μm or less.

[0247] (Mechanism of action) This embodiment offers the following advantages. Specifically, even when a protective layer is present on only one side of the linear polarizer, this embodiment can suppress the disappearance of the dichroic dye from the linear polarizer in high-temperature and high-humidity environments, and can provide an optical laminate with improved visibility (interference unevenness and air bubble inclusion). The reason for this is unknown, but the following mechanism is considered.

[0248] If the first adhesive layer 150 is a cured layer of a curable composition containing a cationic polymerizable compound, it is conceivable that the crosslinking density of the first adhesive layer 150 will be higher compared to water-based adhesives and adhesive layers, and that this will hinder the movement of dichroic dyes such as iodine from the linear polarizer to the phase difference layer laminate, even when exposed to a high-temperature, high-humidity environment.

[0249] Furthermore, because the second adhesive layer 40 is thin, with a thickness of 20-200 nm, interference between the first liquid crystal phase difference layer 30 and the second liquid crystal phase difference layer 50 occurs in the ultraviolet region, suppressing the visibility of interference unevenness in visible light. Additionally, because the second adhesive layer is not too thin, it provides high adhesion and suppresses the inclusion of air bubbles.

[0250] Furthermore, it was found that in configurations with a thin second adhesive layer of 200 nm or less, interference unevenness is suppressed more than in a normal optical laminate, indicating that the thickness of the first adhesive layer significantly affects the visibility of the optical laminate. While thickness unevenness increases with increasing thickness of the first adhesive layer, when the thickness of the first adhesive layer is thinned to 3.0 μm or less, the variation in optical path difference caused by thickness unevenness of the adhesive layer is suppressed, further reducing interference unevenness. Furthermore, it was found that thin optical laminates, where the second adhesive layer is thin (200 nm or less) and a protective layer is provided on only one side, are prone to wrinkling due to curing shrinkage of the adhesive. When the first adhesive layer is thin (3.0 μm or less), the total amount of stress generated during curing shrinkage is reduced, thus suppressing wrinkling of the optical laminate. In addition, if the first adhesive layer is a cured product of a curable composition containing a cationic polymerizable compound, the curing reaction rate is slow, resulting in an optical laminate with suppressed wrinkling.

[0251] Furthermore, if the phase difference layer laminate satisfies equations (1) and (2) above, it has the effect of effectively suppressing the reflection of ambient light by electrodes in the OLED across the entire visible light spectrum.

[0252] <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 positioned on the viewing side of the image display element (image display cell). The optical laminate can be bonded to the image display element using an adhesive layer.

[0253] The image display device is not particularly limited and examples include organic electroluminescent (organic EL) display devices, inorganic electroluminescent (inorganic EL) display devices, liquid crystal display devices, and electroluminescent display devices.

[0254] Image display devices can be used as mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic signs, measuring instruments or gauges, office equipment, medical equipment, computer equipment, etc. [Examples]

[0255] The present invention will be described more specifically 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 mass percent and parts by mass, respectively.

[0256] <Measuring Thickness> The layer thickness was measured using a contact-type film thickness measuring device (Nikon Corporation "MS-5C"). The thickness of the polarizer and alignment film was measured using a scanning white light interference microscope (Hitachi High-Tech Science Corporation "VS1000"). The thickness of the water-based adhesive layer was measured using an AFM (Shimadzu Corporation "SPM9700HT") on a cross-section obtained by cross-sectional processing of the phase difference layer using a microtome.

[0257] <Measuring Phase Difference Values> The phase difference values ​​of the first liquid crystal phase difference layer and the second liquid crystal phase difference layer were measured using a phase difference measuring device (KOBRA-WR, manufactured by Oji Instruments Co., Ltd.). The phase difference values ​​of the phase difference layer were measured using a phase difference measuring device (KOBRA-PR, manufactured by Oji Instruments Co., Ltd.) after peeling the separator film 2 from the optical laminate and bonding it to the glass. The in-plane phase difference values ​​for light at wavelengths of 450 nm, 550 nm, and 650 nm were determined from Cauchy's dispersion formula obtained from the measurement results of the in-plane phase difference values ​​for light at wavelengths of 448.2 nm, 498.6 nm, 548.4 nm, 587.3 nm, 628.7 nm, and 748.6 nm.

[0258] <Preparation of water-based adhesive composition> At room temperature, the following compositional liquids A and B were mixed in a mass ratio of 1:1 and stirred for 30 minutes to prepare a water-based adhesive composition for forming a water-based adhesive layer. Composition Solution A: An acetoacetyl-modified polyvinyl alcohol resin (Mitsubishi Chemical Corporation, "Gosenol Z200") with a saponification degree of 99.2 mol% was dissolved in water (distilled water) to prepare an aqueous PVA solution with a solid 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 mixture was further adjusted so that the total solid content was 3 parts per 100 parts of water to prepare Composition Solution A. Composition Solution B: An acetoacetyl-modified polyvinyl alcohol resin (Mitsubishi Chemical Corporation, "Gosenol Z200") with a saponification degree of 99.2 mol% was dissolved in water (distilled water) to prepare an aqueous PVA solution with a solid content of 8% by mass. The prepared 8% by mass PVA solution and zinc chloride were mixed in a mass ratio of 3.0:0.09, and the total solid content was further adjusted to 3 parts per 100 parts of water to prepare Composition Solution B. The in-plane mean refractive index of the dried and cured product of the water-based adhesive composition was 1.52.

[0259] <Preparation of adhesive composition (1): Cationic polymerizable> After mixing the following components, the mixture was degassed to prepare an active energy ray-curable adhesive composition (1). Note that the amount of cationic polymerization initiator (OXT-221) in the following formulations is the amount of solid content.

[0260] [Cationically polymerizable compounds] · 3',4'-Epoxycyclohexylmethyl 3',4'-Epoxycyclohexanecarboxylate (Daicel Corporation "CEL2021P"): 32.5 parts by mass [ka] • Epoxy compound containing alicyclic structure (Daicel Corporation's "EHPE3150"): 7.5 parts by mass [ka] · 3,3'-(oxybismethylene)bis(3-ethyloxacyclobutane) (Toagosei Co., Ltd. "OXT-221"): 60 parts by mass [ka]

[0261] [Photocationic polymerization initiator] • Cationic polymerization initiator (product name: CPI-100P 50% solution propylene carbonate solution, manufactured by Sunapro Co., Ltd.): 4.5 parts by mass (actual solid content 2.25 parts by mass)

[0262] [Photosensitizer] • 1,4-Diethoxynaphthalene: 2 parts by mass

[0263] <Preparation of adhesive composition (2): Cationic polymerizable> After mixing the following components, the mixture was degassed to prepare an active energy ray-curable adhesive composition (2).

[0264] [Cationically polymerizable compounds] ·3',4'-Epoxycyclohexylmethyl3,4-Epoxycyclohexanecarb Silate (product name: CEL2021P, manufactured by Daicel Corporation): 70 parts by mass [ka] • Neopentyl glycol diglycidyl ether (product name: EX-211, manufactured by Nagase ChemteX Corporation): 20 parts by mass [ka] • 2-Ethylhexylglycidyl ether (Product name: EX-121, Nagase ChemteX) (Manufactured by [Company Name]): 10 parts by mass [ka]

[0265] [Photocationic polymerization initiator] • Cationic polymerization initiator (product name: CPI-100P 50% solution propylene carbonate solution, manufactured by Sunapro Co., Ltd.): 4.5 parts by mass (actual solid content 2.25 parts by mass)

[0266] [Photosensitizer] • 1,4-Diethoxynaphthalene: 2 parts by mass

[0267] <Preparation of adhesive composition (3): Cationic polymerizable> After mixing the following components, the mixture was degassed to prepare an active energy ray-curable adhesive composition (3). [Cationically polymerizable compounds] · 3',4'-Epoxycyclohexylmethyl 3,4-Epoxycyclohexanecarboxylate (Trade name: CEL2021P, manufactured by Daicel Corporation): 19 parts by mass [ka] • Neopentyl glycol diglycidyl ether (product name: EX-211, Nagase Chemte) (Manufactured by KS Corporation): 64 parts by mass [ka] • 2-Ethylhexylglycidyl ether (Product name: EX-121, Nagase ChemteX) (Manufactured by [Company Name]): 7 parts by mass [ka] • PolyGMA-MMA: 10 parts by mass

[0268] [Photocationic polymerization initiator] • Cationic polymerization initiator (product name: CPI-100P 50% solution propylene carbonate solution, manufactured by Sunapro Co., Ltd.): 4.5 parts by mass (actual solid content 2.25 parts by mass)

[0269] <Preparation of adhesive composition (4): Cationic polymerizable> The following components were mixed and then degassed to prepare adhesive composition (4). [Cationically polymerizable compounds] • Neopentyl glycol diglycidyl ether (product name: EX-211L, manufactured by Nagase ChemteX Corporation) 30 parts by mass [ka] • 3-Ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane (trade name: OXT-221, manufactured by Toagosei Co., Ltd.) 13 parts by mass [ka] • Bisphenol A type epoxy resin (product name: EP-4100E, ADEKA Corporation, viscosity 13 Pa·s (temperature 25℃)) 45 parts by mass ·Aromatic-containing oxetane compound (product name: TCM-104, manufactured by TRONLY) 12 parts by mass

[0270] [Photocationic polymerization initiator] • CPI-100P, manufactured by Sunapro Co., Ltd., 50% propylene carbonate solution, 2.25 parts by mass (solid content)

[0271] [Photosensitizer] • 1,4-Diethoxynaphthalene 1 part by mass The in-plane average refractive index of the cured product of adhesive composition (4) was 1.54.

[0272] <Preparation of adhesive layer (1): Acrylic-based> (Preparation of acrylic resin solution (1)) A reaction vessel equipped with a condenser, nitrogen inlet tube, 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 internal temperature was raised to 55°C while replacing the air in the apparatus with nitrogen gas to eliminate oxygen. Subsequently, the entirety of a solution prepared by dissolving 0.12 parts azobisisobutyronitrile (polymerization initiator) in 10 parts ethyl acetate was added. After adding the polymerization initiator, the temperature was maintained at this level for 1 hour. Then, while maintaining the internal temperature at 54-56°C, ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts / hr. When the concentration of the (meth)acrylic resin reached 35% by mass, the addition of ethyl acetate was stopped, and the temperature was maintained at this level for another 6 hours from the start of ethyl acetate addition. Finally, ethyl acetate was added to adjust the concentration of the (meth)acrylic resin to 20% by mass, and acrylic resin solution (1) was prepared. The obtained 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 "TSKgel GMH" manufactured by Tosoh Corporation as the column in the GPC instrument. HR Two "-H(S)" units were connected in series, tetrahydrofuran was used as the eluate, and measurements were taken using standard polystyrene equivalents under the following conditions: sample concentration of 2 mg / mL, sample introduction volume of 100 μL, temperature of 40°C, and flow rate of 1 mL / min.

[0273] (Preparation of adhesive composition (1)) To 80 parts of the solid content of the acrylic resin solution (1) obtained above, 20 parts (solid content) of difunctional acrylate (obtained from Shin Nakamura Chemical Industry Co., Ltd.; product number "A-DOG"), 2.5 parts on an active ingredient basis of a crosslinking agent (manufactured by Tosoh Corporation: product name "Coronate L" (ethyl acetate solution of 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 then ethyl acetate was added to bring the solid content concentration to 13% to obtain the 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]

[0274] (Preparation of 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 subjected to a release treatment ["PLZ-383030" obtained from Lintec Corporation] using an applicator so that the thickness after drying was 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 subjected to 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. The storage elastic modulus of the adhesive layer (1) at 23 °C was 110 kPa, the storage elastic modulus at 80 °C was 54 kPa, and the refractive index with respect to light having 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

[0275] (Preparation of Adhesive Layer (2): Acrylic Type) (Preparation of Acrylic Resin Solution (2)) A reaction vessel equipped with a condenser, nitrogen inlet tube, 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 internal temperature was raised to 55°C while replacing the air in the apparatus with nitrogen gas to eliminate oxygen. Subsequently, the entirety of a solution prepared by dissolving 0.15 parts azobisisobutyronitrile (polymerization initiator) in 10 parts ethyl acetate was added. After adding the polymerization initiator, the temperature was maintained at this level for 1 hour. Then, while maintaining the internal temperature at 54-56°C, ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts / hr. When the concentration of the (meth)acrylic resin reached 35% by mass, the addition of ethyl acetate was stopped, and the temperature was maintained at this level for another 6 hours from the start of ethyl acetate addition. Finally, ethyl acetate was added to adjust the concentration of the (meth)acrylic resin to 20% by mass, and acrylic resin solution (2) was prepared. The obtained 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 "TSKgel GMH" manufactured by Tosoh Corporation as the column in the GPC instrument. HR Two "-H(S)" units were connected in series, tetrahydrofuran was used as the eluate, and measurements were taken using standard polystyrene equivalents under the following conditions: sample concentration of 2 mg / mL, sample introduction volume of 100 μL, temperature of 40°C, and flow rate of 1 mL / min.

[0276] (Preparation of 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" (ethyl acetate solution of 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 then ethyl acetate was added to bring the solid content concentration to 13% to obtain the adhesive composition (2).

[0277] (Preparation of adhesive sheet (2)) The adhesive composition (2) prepared above was applied to the release-treated surface of a separator film 1 (PLR-382190, obtained from Lintec Corporation) made of polyethylene terephthalate film with a release treatment using an applicator to a dry thickness of 25 μm, and dried at 100°C for 1 minute to produce an adhesive layer (2). Next, the surface of the obtained adhesive layer (2) opposite to the separator film was laminated to the release-treated surface of a separator film 2 (PET-251130, obtained from Lintec Corporation) made of polyethylene terephthalate film with a release treatment, to produce an adhesive sheet (2) consisting of separator film 1 / adhesive layer (2) / separator film 2. The storage modulus of adhesive layer (2) at 23°C was 25 kPa, the storage modulus at 80°C was 19 kPa, and the refractive index for light at a wavelength of 589 nm was 1.48.

[0278] (Fabrication of linear polarizers) A polyvinyl alcohol film with 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 hot roll, and while maintaining tension, was immersed for 60 seconds in a 28°C staining bath containing 0.05 parts by mass of iodine and 5 parts by mass of potassium iodide per 100 parts by mass of water. Next, the polarizer was immersed for 110 seconds in a 64°C boric acid aqueous solution 1 containing 5.5 parts by mass of boric acid and 15 parts by mass of potassium iodide per 100 parts by mass of water. Then, it was immersed for 30 seconds in a 67°C boric acid aqueous solution 2 containing 5.5 parts by mass of boric acid and 15 parts by mass of potassium iodide per 100 parts by mass of water. After that, it was washed with pure water at 10°C and dried to obtain a linear polarizer. The thickness of the polarizer was 8 μm and the boron content was 4.3% by mass.

[0279] <Fabrication of polarizing plate (1)> The aqueous adhesive composition obtained above was applied to one side of the linear polarizer obtained above, and a cyclic polyolefin resin film with a hard coat (HC) layer (COP film) was laminated onto it. A TAC film was laminated to the other side of the polarizer via water, and after drying at 80°C for 5 minutes, the TAC film was peeled off to obtain a polarizer having a protective film on one side of the linear polarizer. The layer structure of the polarizer is COP film / aqueous adhesive layer / linear polarizer.

[0280] <Fabrication of the first and second liquid crystal phase difference layers> (Preparation of the 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 heated at 100°C for 1 hour to obtain an oriented polymer composition (1).

[0281] (Preparation of photo-oriented polymer composition (1)) A photo-oriented material with the following structure (weight-average molecular weight: 50,000, m:n=50:50) was manufactured according to the method described in Japanese Patent Application Publication No. 2021-196514. Two parts of the photo-oriented material and 98 parts of propylene glycol monomethyl ether (PGME, solvent) were mixed as components, and the resulting mixture was stirred at 80°C for 1 hour to prepare a photo-oriented polymer composition (1). Photoalignable materials: [ka]

[0282] (Manufacturing of polymerizable liquid crystal compounds) Polymerizable liquid crystal compounds (A1) and (A2), having the structures shown below, were prepared, respectively. Polymerizable liquid crystal compounds (A1) and (A2) were prepared in the same manner as described in Japanese Patent Application Publication No. 2010-244038.

[0283] Polymerizable liquid crystal compound (A1): [ka]

[0284] Polymerizable liquid crystal compound (A2): [ka]

[0285] (Preparation of liquid crystal phase difference layer formation 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 the leveling agent "Megafac F-556" (manufactured by DIC Corporation), the photopolymerization initiator "Omnirad907" (manufactured by IGM Resin BV Corporation), and an ionic compound (B) were added. Furthermore, propylene glycol monomethyl ether acetate (PEGMEA) was added, and this mixture was stirred at a temperature of 80°C for 1 hour to prepare a liquid crystal phase difference layer forming composition (Y1). The amounts of each component added are shown in Table 1 below.

[0286] [Table 1]

[0287] Ionic compounds (B): [ka]

[0288] (Preparation of liquid crystal phase difference layer formation 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 monomethyl ether acetate (PEGMEA) was added, and this mixture was stirred at 80°C for 1 hour to prepare a liquid crystal phase difference layer forming composition (Y2). The amounts of each component added are shown in Table 2 below.

[0289] [Table 2]

[0290] Polymerizable liquid crystal compound LC242: [ka]

[0291] <Fabrication of the first liquid crystal phase difference layer film (Z1)> Rectangular cut triacetylcellulose film (TAC) (thickness 40 μm, temperature 40°C, relative humidity 90% RH, moisture permeability 950 g / m²) 2 An oriented polymer composition (1) was applied to the surface of the TAC (Turn Aqueous Cell) at 24 hours to form an oriented polymer film with a thickness of 100 nm after heating and drying. The surface of the obtained oriented polymer film was rubbed from the longitudinal direction of the TAC at an angle of -15° to the slow axis of the first liquid crystal phase difference layer (X1) to be formed below, and then a liquid crystal phase difference layer forming composition (Y1) was applied thereon using a bar coater. The obtained coated film was dried at 100°C for 1 minute and then cooled to room temperature to obtain a dried film. Next, an exposure dose of 1000 mJ / cm² was applied under a nitrogen atmosphere using a high-pressure mercury lamp (UniCure VB-15201BY-A manufactured by Ushio Inc.). 2By irradiating the dried film with ultraviolet light (based on 365 nm), a first liquid crystal phase difference layer (X1) was formed in which the polymerizable liquid crystal compound was cured in a state where it was oriented horizontally with respect to the substrate plane, and a phase difference film (Z1) consisting of TAC / alignment film / first liquid crystal phase difference layer (X1) (horizontally oriented liquid crystal cured film) was obtained. The thickness of the obtained first liquid crystal phase difference layer (X1) was measured with a laser microscope and found to be 1.8 μm. The in-plane phase difference value was measured using a KOBRA-WR manufactured by Oji Instruments Co., Ltd. As a result, the in-plane phase difference value at a wavelength of 550 nm was Re(550) = 236 nm, the in-plane phase difference value at a wavelength of 450 nm was Re(450) = 256 nm, and the in-plane phase difference value at a wavelength of 650 nm was Re(650) = 231 nm. Note that the phase difference value of TAC at a wavelength of 550 nm is approximately 0, so it does not affect the optical properties. The orientation angle was -15° with respect to the longitudinal direction of the TAC. The first liquid crystal phase difference layer (X1) was a positive wavelength dispersion λ / 2 layer. The in-plane average refractive index of the first liquid crystal phase difference layer (X1) was 1.54.

[0292] <Fabrication of the second liquid crystal phase difference layer film (Z2)> A photo-aligning polymer composition (1) was applied to a rectangular piece of triacetylcellulose film (TAC) (thickness 40 μm, moisture permeability 950 g / m2 · 24hr at 40°C and 90% RH relative humidity). The resulting coated film was dried at 120°C for 2 minutes, then cooled to room temperature to form a dry film. Furthermore, using a UV irradiation device, polarized ultraviolet light of 100 mJ (based on 313 nm) was continuously irradiated so that the slow axis of the resulting second liquid crystal phase difference layer (X2) was 75° relative to the longitudinal direction of the TAC, forming a 100 nm photo-aligned film. On this, a liquid crystal phase difference layer forming composition (Y2) was applied using a bar coater. The resulting coated film was dried at 100°C for 1 minute, then cooled to room temperature to obtain a dry film. Next, exposure of 1000 mJ / cm² was performed using a high-pressure mercury lamp under a nitrogen atmosphere. 2By continuously irradiating the dried film with ultraviolet light (based on 365 nm), a second liquid crystal phase difference layer (X2) was formed in which the polymerizable liquid crystal compound was cured in a state where it was oriented horizontally with respect to the substrate plane, and a phase difference film (Z2) consisting of TAC / alignment film / second liquid crystal phase difference layer (X2) (horizontally oriented liquid crystal cured film) was obtained. The thickness of the obtained second liquid crystal phase difference layer (X2) was measured with a laser microscope and found to be 1.0 μm. The in-plane phase difference value was measured using a KOBRA-WR manufactured by Oji Instruments Co., Ltd. As a result, the in-plane phase difference value at a wavelength of 550 nm was Re(550) = 115 nm, the in-plane phase difference value at a wavelength of 450 nm was Re(450) = 130 nm, and the in-plane phase difference value at a wavelength of 650 nm was Re(650) = 111 nm. Note that the phase difference value of TAC at a wavelength of 550 nm is approximately 0, so it does not affect the optical properties. The orientation angle was 75° with respect to the longitudinal direction of the TAC. The second liquid crystal phase difference layer (X2) was a positive wavelength dispersion λ / 4 layer. The in-plane mean refractive index of the second liquid crystal phase difference layer (X2) was 1.54.

[0293] <Fabrication of Phase Difference Layered Stack 1> The first liquid crystal phase difference layer (X1) of the first liquid crystal phase difference layer film (Z1) and the second liquid crystal phase difference layer (X2) of the second liquid crystal phase difference layer film (Z2) were subjected to corona treatment at a rate of 28 kJ / m2. A coating film of the aqueous adhesive composition obtained above was formed on the first liquid crystal phase difference layer (X1) of the first liquid crystal phase difference layer film (Z1) so that the thickness of the aqueous adhesive layer after drying was an arbitrary thickness (0.01 to 0.25 μm). Subsequently, the second liquid crystal phase difference layer (X2) of the second liquid crystal phase difference layer film (Z2) was laminated on the coating film of the aqueous adhesive composition and dried for 3 minutes in an atmospheric atmosphere at a temperature of 90°C to obtain a phase difference layer laminate 1 in which TAC / alignment film / first liquid crystal phase difference layer (X1) / aqueous adhesive layer / second liquid crystal phase difference layer (X2) / alignment film / TAC was laminated in this order. Phase difference film (Z1) and phase difference film (Z2) were laminated so that their longitudinal directions were aligned. When viewed in the thickness direction from the phase difference film (Z2) side, the slow phase axis of the first liquid crystal phase difference layer (X1) of phase difference film (Z1) was tilted at 15° with respect to the longitudinal direction of phase difference laminate 1, and the slow phase axis of the second liquid crystal phase difference layer (X2) of phase difference film (Z2) was tilted at 75°, resulting in an angle of 60° between the slow phase axes. The transmittance of phase difference laminate 1 at 311 nm was 11%.

[0294] <Fabrication of Phase Difference Layered Stack 2> The first liquid crystal phase difference layer (X1) of the first liquid crystal phase difference layer film (Z1) and the second liquid crystal phase difference layer (X2) of the second liquid crystal phase difference layer film (Z2) are each supplied with 28 kJ / m³ 2 Corona treatment was performed under the following conditions. The adhesive (4) was applied to the first liquid crystal phase difference layer (X1) of the first liquid crystal phase difference layer film (Z1) so that the thickness of the cured adhesive (4) was 2 μm. Then, the second liquid crystal phase difference layer (X2) surface of the second liquid crystal phase difference layer film (Z2) was laminated on top of the adhesive (4) coating. The adhesive (4) was cured by irradiating it with ultraviolet light from the side of the second liquid crystal phase difference layer film (Z2), and a phase difference layer laminate 2 was obtained in which TAC / alignment film / first liquid crystal phase difference layer (X1) / adhesive layer (4) / second liquid crystal phase difference layer (X2) / alignment film / TAC was laminated in this order. The ultraviolet light was UVA with a wavelength of 320 nm to 390 nm at a rate of 420 mJ / cm². 2The light was irradiated in such a manner. Phase difference film (Z1) and phase difference film (Z2) were stacked so that their longitudinal directions were aligned. When viewed in the thickness direction from the phase difference film (Z2) side, the slow phase axis of the first liquid crystal phase difference layer (X1) of phase difference film (Z1) was tilted at 15° with respect to the longitudinal direction of the phase difference laminate 1, and the slow phase axis of the second liquid crystal phase difference layer (X2) of phase difference film (Z2) was tilted at 75°, resulting in an angle of 60° between the slow phase axes.

[0295] (Example 1) The TAC / alignment film on the first liquid crystal phase difference layer (X1) side of the phase difference layer laminate 1, which was prepared with a second adhesive layer such that the thickness of the water-based adhesive layer after drying was 0.04 μm, was peeled off, and 28 kJ / m³ was applied to the first liquid crystal phase difference layer (X1). 2 Corona treatment was performed under the following conditions. The adhesive composition (1) was applied to the linear polarizer of a polarizing plate obtained such that the thickness of the cured adhesive layer (1) was 2 μm. Then, the corona-treated side of the phase difference layer laminate 1 obtained above was bonded to the adhesive composition (1) coating using a roll laminating machine so that the absorption axis of the polarizer was 90° with respect to the longitudinal direction of the phase difference layer laminate, that is, so that the transmission axis of the polarizing plate coincided with the longitudinal direction of the phase difference layer laminate. The adhesive composition (1) was cured by irradiating the first liquid crystal phase difference layer (X1) with ultraviolet light to form an adhesive layer (1). The alignment film / TAC on the second liquid crystal phase difference layer (X2) side of the resulting laminate was peeled off, the separator film 1 was peeled off from the adhesive sheet (2), and the adhesive layer (2) side was bonded to the second liquid crystal phase difference layer (X2). This resulted in an optical laminate in which the COP film / water-based adhesive layer / linear polarizer / adhesive layer (1) / first liquid crystal phase difference layer (X1) / water-based adhesive layer / second liquid crystal phase difference layer (X2) / adhesive layer (2) / separator film 2 were laminated in this order. The ultraviolet light used was UVA with wavelengths of 320 nm to 390 nm at a concentration of 420 mJ / cm². 2 The irradiation was applied in such a manner that it resulted in the following:

[0296] (Example 2) The adhesive layer (2) was formed using adhesive composition (2) instead of adhesive composition (1) as the adhesive composition for the first adhesive layer, in the same manner as in Example 1.

[0297] (Example 3) The adhesive layer (3) was formed using adhesive composition (3) instead of adhesive composition (1) as the adhesive composition for the first adhesive layer, in the same manner as in Example 1.

[0298] (Example 4) The sample was prepared in the same manner as in Example 1, except that the thickness of the water-based adhesive layer after drying of the second adhesive layer was set to 0.10 μm.

[0299] (Example 5) The sample was prepared in the same manner as in Example 1, except that the thickness of the water-based adhesive layer after drying of the second adhesive layer was set to 0.15 μm.

[0300] (Example 6) The procedure was the same as in Example 1, except that the thickness of the first adhesive layer was set to 1.0 μm.

[0301] (Example 7) The procedure was the same as in Example 1, except that the thickness of the first adhesive layer was set to 1.2 μm.

[0302] (Example 8) The procedure was the same as in Example 1, except that the thickness of the first adhesive layer was set to 1.5 μm.

[0303] (Example 9) The procedure was the same as in Example 1, except that the thickness of the first adhesive layer was set to 3.0 μm.

[0304] (Comparative Example 1) The TAC / alignment film on the first liquid crystal phase difference layer (X1) side of the phase difference layer laminate 1, which was prepared so that the thickness of the water-based adhesive layer after drying was 0.04 μm, was peeled off, and the first liquid crystal phase difference layer (X1) was subjected to corona treatment at a condition of 28 kJ / m2. A coating film of water-based adhesive was formed on the PVA surface of the polarizing plate (1) so that the thickness of the water-based adhesive layer after drying was 0.04 μm. Then, the corona-treated side of the phase difference layer laminate (1) obtained above was bonded to the water-based adhesive coating film using a roll laminating machine so that the absorption axis of the polarizer was 90° with respect to the longitudinal direction of the phase difference layer laminate, that is, so that the transmission axis of the polarizing plate coincided with the longitudinal direction of the phase difference layer laminate. After bonding, drying treatment was performed at 80°C for 3 minutes. The alignment film / TAC on the second liquid crystal phase difference layer (X2) side of the obtained laminate was peeled off, the separator film 1 was peeled off from the adhesive sheet (2), and the adhesive layer (2) side was bonded to the second liquid crystal phase difference layer (X2), thereby obtaining an optical laminate in which the COP film / water-based adhesive layer / polarizer / water-based adhesive layer / first liquid crystal phase difference layer (X1) / water-based adhesive layer / second liquid crystal phase difference layer (X2) / adhesive layer (2) / separator film 2 were laminated in this order.

[0305] (Comparative Example 2) The separator film 1 was peeled from the adhesive sheet (1), and the adhesive layer (1) surface was subjected to corona treatment at a rate of 28 kJ / m2. Then, the adhesive layer (1) side was bonded to the linear polarizer surface of the polarizing plate (1). The separator film 2 of the resulting laminate was peeled off, and the other side of the adhesive layer (1) was subjected to corona treatment at a rate of 28 kJ / m2. 2 Corona treatment was performed under the following conditions. After peeling off the TAC / alignment film on the first liquid crystal phase difference layer (X1) side of the phase difference layer laminate 1, which was prepared so that the thickness of the water-based adhesive layer after drying was 0.04 μm, 28 kJ / m³ was applied to the first liquid crystal phase difference layer (X1). 2Corona treatment was performed under the following conditions. The first liquid crystal phase difference layer (X1) of the phase difference layer laminate and the adhesive layer (1) surface of the polarizing plate (1) with the adhesive layer (1) obtained earlier were bonded together such that the absorption axis of the polarizing plate (1) was 90° with respect to the longitudinal direction of the phase difference layer (3), that is, the transmission axis of the polarizing plate coincided with the longitudinal direction of the phase difference layer laminate. The alignment film / TAC on the second liquid crystal phase difference layer (X2) side of the resulting laminate was peeled off, the separator film 1 was peeled off from the adhesive sheet (2), and the adhesive layer (2) side was bonded to the second liquid crystal phase difference layer (X2), thereby obtaining an optical laminate in which the COP film / water-based adhesive layer / polarizer / adhesive layer (1) / first liquid crystal phase difference layer (X1) / water-based adhesive layer / second liquid crystal phase difference layer (X2) / adhesive layer (2) / separator film 2 were laminated in this order.

[0306] (Comparative Example 3) The procedure was the same as in Example 1, except that adhesive composition (4) was used to form the adhesive layer (4) as the adhesive composition for the second adhesive layer. The thickness of the second adhesive layer was 2 μm.

[0307] (Comparative Example 4) The sample was prepared in the same manner as in Example 1, except that the thickness of the water-based adhesive layer after drying of the second adhesive layer was set to 0.01 μm.

[0308] (Comparative Example 5) The sample was prepared in the same manner as in Example 1, except that the thickness of the water-based adhesive layer after drying of the second adhesive layer was set to 0.25 μm.

[0309] <Phase difference value of phase difference laminate> In each example and comparative example, the Re(450) and Re(550) of the phase difference layer laminate were measured. The Re(450) was 112 nm, and the Re(450) / Re(550) was 0.80.

[0310] <Method for measuring the peeling force between the first liquid crystal phase difference layer and the second liquid crystal phase difference layer> The measurement was performed using the method described above.

[0311] <Rating> (Evaluation of unevenness and air bubble inclusion in optical laminates) The optical laminate was cut to a size of 150 mm x 150 mm. The cut optical laminate was attached to an aluminum reflector to obtain a test specimen for observing interference unevenness. The test specimen for observing interference unevenness was placed on a stand so that it made an angle of 45° with respect to the floor, with the floor being 0°. Linear polarizers were placed between the three-wavelength fluorescent lamp (as the light source) and the test specimen for observing interference unevenness, and between the test specimen and the observer, so that their transmission axes were perpendicular to each other (crossed nicols). The light from the three-wavelength fluorescent lamp was shone onto the test specimen for observing interference unevenness from the 90° direction (above the test specimen). When the observer observed the test specimen from the 0° direction, the test specimen was rotated so that it could be observed and evaluated from various directions. Unevenness Rating A: No interference unevenness is visible. B: Slight interference unevenness is visible. C: Interference irregularities are clearly visible. D: Strong interference unevenness is visible. Bubble evaluation A: No bubbles are visible. B: A few bubbles are visible. C: Bubbles are clearly visible. D: Strong bubbles are visible.

[0312] (Durability evaluation of optical laminates) An organic EL display device was fabricated by peeling off the separator film 2 from the optical laminate and bonding the optical laminate to an organic EL display element via the exposed adhesive layer (2). The color and appearance of the optical laminate were observed after storing the organic EL display device for 19 hours under conditions of 85°C and 85% RH. However, color loss at the edges was evaluated only for the edges parallel to the absorption axis direction of the polarizer. A: Discoloration at the edges (less than 30 μm) B: Discoloration at the edges (30μm or more and less than 50μm) C: Discoloration at the edges (50μm or more)

[0313] (Evaluation of appearance defects due to wrinkles) The optical laminate was observed by reflecting a fluorescent light onto the first protective layer surface. A: Wrinkles are not visible. B: Slight wrinkles are visible.

[0314] Table 3 shows the composition of the cationic polymerizable compounds in adhesive compositions (1) to (4). Tables 4 and 5 show the conditions and results.

[0315] [Table 3]

[0316] [Table 4]

[0317] [Table 5] [Explanation of Symbols]

[0318] 30...First liquid crystal phase difference layer, 40...Second adhesive layer, 50...Second liquid crystal phase difference layer, 150...First adhesive layer, 180...First protective layer, 220...Linear polarizer, 300...Phase difference layer laminate, 400...Optical laminate (circular polarizer).

Claims

1. The structure comprises a first protective layer, a linear polarizer, a first adhesive layer, and a phase difference layer laminate in this order. The first adhesive layer is a cured layer of a curable composition containing a cationic polymerizable compound. The phase difference layer laminate is an optical laminate having a first liquid crystal phase difference layer, a second adhesive layer having a thickness of 20 to 200 nm, and the second liquid crystal phase difference layer in this order from the first adhesive layer side.

2. The optical laminate according to claim 1, wherein the thickness of the first adhesive layer is 0.5 to 3.0 μm.

3. The optical laminate according to claim 1 or 2, wherein the curable composition of the first adhesive layer contains 20 to 80 parts by mass of an alicyclic epoxy compound when the total amount of cationic polymerizable compound is 100 parts by mass.

4. The optical laminate according to claim 1 or 2, wherein the cationic polymerizable compound of the curable composition of the first adhesive layer contains an oxetane compound.

5. The optical laminate according to claim 1 or 2, wherein the second adhesive layer is a water-based adhesive layer.

6. The optical laminate according to claim 1 or 2, wherein the thickness of the second adhesive layer is 30 to 120 nm.

7. The optical laminate according to claim 1 or 2, wherein the peeling force between the first liquid crystal phase difference layer and the second liquid crystal phase difference layer is 0.20 N / 25 mm or more.

8. The optical laminate according to claim 1 or 2, wherein when the in-plane phase difference value of the phase difference layer laminate with respect to light of wavelength λ nm is Re(λ), the relationship between the following equations (1) and (2) is satisfied. 80 nm ≤ Re(450) ≤ 130 nm (1) Re(450) / Re(550)≦1.00 (2)

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