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 radical 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 radical 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 curable composition of the first adhesive layer contains a trifunctional urethane acrylate, as described in [1] or [2]. [4] The optical laminate according to any one of [1] to [3], wherein the curable composition of the first adhesive layer comprises a monofunctional (meth)acrylate and a polyfunctional (meth)acrylate, and the mass ratio of the polyfunctional (meth)acrylate to the mass of the monofunctional (meth)acrylate is 1 or more. [5] The optical laminate described in [1] to [4], wherein the first adhesive layer has a tensile modulus of 100 MPa or more at 23°C. [6] The optical laminate according to any one of [1] to [5], wherein the second adhesive layer is a water-based adhesive layer. [7] The optical laminate according to any one of [1] to [6], wherein the thickness of the second adhesive layer is 30 to 120 nm. [8] The optical laminate according to any one of [1] to [7], 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. [9] 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 the following equations (1) and (2) is satisfied. 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> A polarizing film, i.e., an optically anisotropic layer made 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 crystal properties (hereinafter also referred to as polymerizable liquid crystal). A polymerizable group is a group that participates in the polymerization reaction, and it is preferable that it be a photopolymerizable group. Here, a photopolymerizable group is a group that can participate in the polymerization reaction by active radicals or acids generated from a photopolymerization initiator, 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 crystal properties may be thermotropic liquid crystal or lyotropic liquid crystal, but when mixed with a dichroic dye, 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 radical 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 cationic 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. Alternatively, the thickness of the first adhesive layer 150 may 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. 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 thinned to 2.5 μm or less, an optical laminate with even more suppressed interference unevenness can be obtained.

[0060] (Materials for the first adhesive layer) The first adhesive layer is a cured layer of a curable composition containing a radical polymerizable compound.

[0061] (Curable composition) The curable composition contains a radical polymerizable compound.

[0062] (Radical polymerizable compounds) Radical polymerizable compounds are compounds or oligomers that undergo radical polymerization reactions and harden upon irradiation with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays, or upon heating. Specifically, examples include compounds having ethylenically unsaturated bonds. Examples of compounds having an ethylenically unsaturated bond include (meth)acrylic compounds having one or more (meth)acryloyl groups in the molecule, and vinyl compounds having one or more vinyl groups in the molecule.

[0063] ((meth)acrylic compounds) Examples of (meth)acrylic compounds include monofunctional (meth)acrylates, polyfunctional (meth)acrylates, and urethane acrylates. In this specification, (meth)acrylate means acrylate or methacrylate, and (meth)acryloyl group means acryloyl group or methacryloyl group.

[0064] (Monofunctional (meth)acrylate) Monofunctional (meth)acrylates are compounds having a monofunctional (meth)acryloyl group. Examples of such compounds include (meth)acrylic acid; C1-C16 alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, and tert-butyl (meth)acrylate; and C4-C16 cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate, 2-methylcyclohexyl (meth)acrylate, tricyclo[5.2.1.02,6]decane-8-yl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, and isobornyl (meth)acrylate. Examples include (meth)acrylates; β-carboxyalkyl (meth)acrylates with 2 to 14 carbon atoms; alkylated phenyl (meth)acrylates with 2 to 14 carbon atoms; methoxypolyethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate; (di)alkyl (meth)acrylamides with 4 to 16 carbon atoms; β-carboxyalkyl (meth)acrylamides with 2 to 14 carbon atoms; alkylated phenyl (meth)acrylamides with 2 to 14 carbon atoms; methoxypolyethylene glycol (meth)acrylamide; phenoxypolyethylene glycol (meth)acrylamide, etc. Monofunctional (meth)acrylates can be used alone or in combination of two or more. In this specification, (meth)acrylate does not include urethane acrylates.

[0065] In one preferred embodiment, from the viewpoint of more advanced suppression or reduction of the diffusion of the dichroic dye contained in the linear polarizer into the phase difference layer laminate, and better prevention of degradation of the linear polarizer, the monofunctional (meth)acrylate in the radical polymerizable compound of the curable composition of the first adhesive layer preferably includes monofunctional (meth)acrylate having a hydroxyl group, and more preferably includes monofunctional (meth)acrylate having a hydroxyl group at the terminal. In this embodiment, the monofunctional (meth)acrylate may consist only of monofunctional (meth)acrylate having a hydroxyl group at the terminal, or may consist only of monofunctional (meth)acrylate having a hydroxyl group at the terminal and monofunctional (meth)acrylate having hydroxyl groups other than at the terminal, or may consist only of monofunctional (meth)acrylate having hydroxyl groups other than at the terminal.

[0066] In one embodiment of the present invention, the content of monofunctional (meth)acrylate having hydroxyl groups is preferably 20 parts by mass or more, more preferably 23 parts by mass or more, even more preferably 25 parts by mass or more, particularly preferably 28 parts by mass or more, preferably 50 parts by mass or less, more preferably 45 parts by mass or less, even more preferably 40 parts by mass or less, particularly preferably 35 parts by mass or less, based on 100 parts by mass of the total radical polymerizable compound (for example, the total of monofunctional (meth)acrylate, polyfunctional (meth)acrylate, and urethane acrylate). When the content of monofunctional (meth)acrylate having hydroxyl groups in the radical polymerizable compound is above the lower limit, the deterioration of the polarization performance of the cured layer over time can be suppressed due to the dissolution suppression effect of the hydroxyl groups. When the content of monofunctional (meth)acrylate having hydroxyl groups in the radical polymerizable compound is below the upper limit, hydrogen bond formation by the hydroxyl groups is reduced, and the viscosity of the curable composition can be reduced.

[0067] The monofunctional (meth)acrylate having a hydroxyl group is preferably a monofunctional (meth)acrylate having a hydroxyl group at the terminal, and more preferably the following formula (1): [ka] [where n represents an integer from 1 to 12, A 1 represents O or NH, X 1 represents a methylene group which may have a substituent. When n is an integer of 2 or more, at least one of the methylene groups may be substituted with an oxygen atom, and the substituents may be the same or different] is a compound represented by the formula. When the monofunctional (meth)acrylate having a hydroxyl group is a compound represented by the above formula (1), a higher degree of suppression or reduction of the diffusion of the dichroic dye contained in the linear polarizer into the retardation layer laminate, and better prevention of deterioration of the linear polarizer can be achieved. This is presumably due to the fact that when the components contained in the linear polarizer dissolve and diffuse into the retardation layer laminate, the dissolution inhibitory effect of the hydroxyl group at the molecular terminal of the polymer of the monofunctional (meth)acrylate having a hydroxyl group is more exerted.

[0068] In the above formula (1), n usually represents an integer from 1 to 12, preferably an integer from 2 to 10, more preferably an integer from 3 to 8, and still more preferably an integer from 4 to 6. When n is at least the lower limit value, the hydroxyl group at the molecular terminal is less likely to be affected by the polymer main chain, and the dissolution inhibitory effect of the hydroxyl group tends to be more exerted. Also, when n is at most the upper limit value, the X 1 portion is less likely to aggregate, so the dissolution inhibitory effect of the hydroxyl group tends to be more exerted. When n is within the above range, when the components contained in the polarizer dissolve and diffuse into the first adhesive layer, the dissolution inhibitory effect of the hydroxyl group at the molecular terminal of the polymer of the monofunctional (meth)acrylate having a hydroxyl group in the first adhesive layer tends to be more exerted.

[0069] In the above formula (1), A 1 usually represents O or NH, and preferably represents O.

[0070] In the above formula (1), X 1X represents a methylene group which may have substituents. When n is an integer of 2 or more, at least one of the methylene groups may be substituted with an oxygen atom, and the substituents may be the same or different. Examples of the substituents include aliphatic or alicyclic hydrocarbon groups having 2 to 10 carbon atoms (e.g., 2 to 5 carbon atoms), or aromatic hydrocarbon groups having 5 to 20 carbon atoms (e.g., 5 to 11 carbon atoms). X represents a methylene group in which at least one of the methylene groups is substituted with an oxygen atom. 1 For example, -(CH2CH2O) m -CH2CH2-, -(CH2CH(CH3)O) m Examples include -CH2CH(CH3)-[where m represents an integer from 1 to 3].

[0071] In one embodiment of the present invention, the content of the compound represented by formula (1) is preferably 20 parts by mass or more, more preferably 23 parts by mass or more, even more preferably 25 parts by mass or more, particularly preferably 28 parts by mass or more, preferably 50 parts by mass or less, more preferably 45 parts by mass or less, even more preferably 40 parts by mass or less, particularly preferably 35 parts by mass or less, based on 100 parts by mass of the total radical polymerizable compounds (for example, the total of monofunctional (meth)acrylate, polyfunctional (meth)acrylate, and urethane acrylate). When the content of the compound represented by formula (1) in the radical polymerizable compounds is above the lower limit, the deterioration of the polarization performance of the cured layer over time can be suppressed due to the dissolution suppression effect of hydroxyl groups, and furthermore, since the fluidity of the curable composition is particularly good, the deterioration of the polarization performance of the linear polarizer accompanying the drying process can be further suppressed. When the content of the compound represented by formula (1) in the radical polymerizable compounds is below the upper limit, hydrogen bond formation by hydroxyl groups is reduced, and the viscosity of the curable composition can be reduced.

[0072] Examples of monofunctional (meth)acrylates having hydroxyl groups include hydroxyalkyl (meth)acrylates with 4 to 16 carbon atoms, hydroxycycloalkyl (meth)acrylates with 4 to 16 carbon atoms, hydroxyalkylated phenyl (meth)acrylates with 2 to 14 carbon atoms, polyethylene glycol (meth)acrylate, hydroxy(di)alkyl (meth)acrylamides with 4 to 16 carbon atoms, hydroxyalkylated phenyl (meth)acrylamides with 2 to 14 carbon atoms, and polyethylene glycol (meth)acrylamides. Preferred examples are hydroxyalkyl (meth)acrylates with 4 to 6 carbon atoms and hydroxycycloalkyl (meth)acrylates with 4 to 16 carbon atoms, and more preferred examples are hydroxyalkyl acrylates with 4 to 6 carbon atoms and hydroxycycloalkyl acrylates with 4 to 16 carbon atoms. Monofunctional (meth)acrylates containing hydroxyl groups can be used alone or in combination of two or more types.

[0073] (Multifunctional (meth)acrylate) A polyfunctional (meth)acrylate is a compound having two or more (meth)acryloyl groups. Radical polymerizable compounds preferably include one or more polyfunctional (meth)acrylates, i.e., one or more (meth)acrylates with two or more functions. The polyfunctional (meth)acrylate preferably includes three or more functions, more preferably four or more functions, and even more preferably five or more functions. When a polyfunctional (meth)acrylate has three or more functional groups, the crosslinking density of the cured product increases, which not only suppresses or reduces the diffusion of dichroic dyes contained in the linear polarizer into the phase difference layer laminate to a higher degree, but also reduces the dependence of the linear polarizer on the external environment to which it is exposed. The number of functional groups of a polyfunctional (meth)acrylate is usually 20 or less, more preferably 10 or less, and even more preferably 8 or less. When the curable composition contains two or more types of polyfunctional (meth)acrylates, it is preferable that the number of functional groups of all types of polyfunctional (meth)acrylates contained in the curable composition is above the lower limit and below the upper limit, and the number of functional groups may be the same or different among the polyfunctional (meth)acrylates.

[0074] Examples of difunctional (meth)acrylates include alkylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate and neopentyl glycol di(meth)acrylate; diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di( Polyoxyalkylene glycol di(meth)acrylates such as meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate and polytetramethylene glycol di(meth)acrylate; halogen-substituted alkylene glycol di(meth)acrylates such as tetrafluoroethylene glycol di(meth)acrylate; trimethylolpropane di(meth)acrylate, ditrimethylolpropane di(meth)acrylate, Di(meth)acrylates of aliphatic polyols such as erythritol di(meth)acrylate; di(meth)acrylates of hydrogenated dicyclopentadiene or tricyclodecane dialkanol such as hydrogenated dicyclopentadienyl di(meth)acrylate and tricyclodecane dimethanol di(meth)acrylate; di(meth)acrylates of dioxane glycol or dioxane dialkanol such as 1,3-dioxane-2,5-diyl di(meth)acrylate (also known as dioxane glycol di(meth)acrylate); bisphenol A ethyl Di(meth)acrylates of alkylene oxide adducts of bisphenol A or bisphenol F, such as bisphenol A diacrylates and bisphenol F ethylene oxide adducts; epoxy di(meth)acrylates of bisphenol A or bisphenol F, such as acrylic acid adducts of bisphenol A diglycidyl ether and acrylic acid adducts of bisphenol F diglycidyl ether; silicone di(meth)acrylates; di(meth)acrylates of neopentyl glycol hydroxypivalate;Examples include 2,2-bis[4-(meth)acryloyloxyethoxyethoxyphenyl]propane; 2,2-bis[4-(meth)acryloyloxyethoxyethoxycyclohexyl]propane; di(meth)acrylate of 2-(2-hydroxy-1,1-dimethylethyl)-5-ethyl-5-hydroxymethyl-1,3-dioxane; and tris(hydroxyethyl)isocyanurate di(meth)acrylate.

[0075] Examples of trifunctional (meth)acrylates include glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, reaction products of pentaerythritol tri(meth)acrylate with acid anhydrides; caprolactone-modified trimethylolpropane tri(meth)acrylate, caprolactone-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, and ethylene oxide Examples include modified pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, propylene oxide-modified pentaerythritol tri(meth)acrylate, isocyanurate tri(meth)acrylate, reaction products of caprolactone-modified pentaerythritol tri(meth)acrylate with acid anhydrides; reaction products of ethylene oxide-modified pentaerythritol tri(meth)acrylate with acid anhydrides; and reaction products of propylene oxide-modified pentaerythritol tri(meth)acrylate with acid anhydrides.

[0076] Examples of tetrafunctional (meth)acrylates include ditrimethylolpropanetetra(meth)acrylate, pentaerythritoltetra(meth)acrylate, dipentaerythritoltetra(meth)acrylate, tripentaerythritoltetra(meth)acrylate, caprolactone-modified pentaerythritoltetra(meth)acrylate, caprolactone-modified tripentaerythritoltetra(meth)acrylate, ethylene oxide-modified pentaerythritoltetra(meth)acrylate, ethylene oxide-modified tripentaerythritoltetra(meth)acrylate, propylene oxide-modified pentaerythritoltetra(meth)acrylate, and propylene oxide-modified tripentaerythritoltetra(meth)acrylate.

[0077] Examples of pentafunctional (meth)acrylates include dipentaerythritol penta(meth)acrylate, tripentaerythritol penta(meth)acrylate, reaction products of dipentaerythritol penta(meth)acrylate with acid anhydrides; caprolactone-modified dipentaerythritol penta(meth)acrylate, caprolactone-modified tripentaerythritol penta(meth)acrylate, ethylene oxide-modified dipentaerythritol penta(meth)acrylate, ethylene oxide-modified tripentaerythritol Examples include dipenta(meth)acrylate, propylene oxide-modified dipentaerythritol penta(meth)acrylate, propylene oxide-modified tripentaerythritol penta(meth)acrylate, reaction products of caprolactone-modified dipentaerythritol penta(meth)acrylate with acid anhydrides; reaction products of ethylene oxide-modified dipentaerythritol penta(meth)acrylate with acid anhydrides; and reaction products of propylene oxide-modified dipentaerythritol penta(meth)acrylate with acid anhydrides.

[0078] Examples of hexafunctional (meth)acrylates include dipentaerythritol hexa(meth)acrylate, tripentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, caprolactone-modified tripentaerythritol hexa(meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified tripentaerythritol hexa(meth)acrylate, propylene oxide-modified dipentaerythritol hexa(meth)acrylate, and propylene oxide-modified tripentaerythritol hexa(meth)acrylate.

[0079] Examples of heptaerythritol (meth)acrylates include tripentaerythritol hepta(meth)acrylate, reaction products of tripentaerythritol hepta(meth)acrylate and acid anhydrides; caprolactone-modified tripentaerythritol hepta(meth)acrylate, reaction products of caprolactone-modified tripentaerythritol hepta(meth)acrylate and acid anhydrides; ethylene oxide-modified tripentaerythritol hepta(meth)acrylate, reaction products of ethylene oxide-modified tripentaerythritol hepta(meth)acrylate and acid anhydrides; propylene oxide-modified tripentaerythritol hepta(meth)acrylate, reaction products of propylene oxide-modified tripentaerythritol hepta(meth)acrylate and acid anhydrides.

[0080] Examples of octa-functional (meth)acrylates include tripentaerythritol octa(meth)acrylate, caprolactone-modified tripentaerythritol octa(meth)acrylate, ethylene oxide-modified tripentaerythritol octa(meth)acrylate, and propylene oxide-modified tripentaerythritol octa(meth)acrylate. These polyfunctional (meth)acrylates can be used individually or in combination of two or more types.

[0081] Polyfunctional (meth)acrylates can play a role in adjusting the crosslinking density of the cured layer depending on their own inter-crosslinking molecular weight and the number of crosslinking points. More specifically, the smaller the inter-crosslinking molecular weight of the polyfunctional (meth)acrylate, the higher the crosslinking density of the cured layer can be, and the more crosslinking points the polyfunctional (meth)acrylate has, the denser the crosslinking density of the cured layer becomes. As a result, the diffusion of components contained in the linear polarizer into the phase difference layer laminate can be suppressed or reduced to a greater extent, and the dependence of the linear polarizer on the external environment to which it is exposed can be reduced.

[0082] In one embodiment of the present invention, from the viewpoint of increasing crosslinking density, the polyfunctional (meth)acrylate has a branched structure, and it is preferable that the number of atoms in the chain (hereinafter sometimes referred to as "linking chain") connecting the branching point closest to the (meth)acryloyl group in the branched structure and the (meth)acryloyl group is 3 or less, and more preferably 2 or less. When the number of atoms is below the upper limit, the crosslinking density of the first adhesive layer increases, the diffusion of components contained in the polarizer into the first adhesive layer can be suppressed or reduced to a higher degree, and the dependence of the polarizer on the external environment to which it is exposed can be reduced. Here, if there are multiple linking chains, it is sufficient that at least one linking chain satisfies the above range of number of atoms, and from the viewpoint of increasing crosslinking density, it is preferable that all linking chains satisfy the above range of number of atoms.

[0083] Among polyfunctional (meth)acrylates, dipentaerythritol hexa(meth)acrylate and tripentaerythritol octa(meth)acrylate are preferred from the viewpoint of increasing the crosslinking density of polarizing films.

[0084] Commercially available polyfunctional (meth)acrylates can also be used. Examples of such commercially available products include A-DOD-N, A-HD-N, A-NOD-N, APG-100, APG-200, APG-400, A-GLY-9E, A-GLY-20E, A-TMM-3, A-TMPT, AD-TMP, ATM-35E, A-TMMT, A-9550, A-DPH, HD-N, NOD-N, NPG, TMPT (all manufactured by Shin Nakamura Chemical Co., Ltd.), ARONIX M-220, ARONIX M-325, ARONIX M-240, ARONIX M-270, ARONIX M-309, ARONIX M-310, ARONIX M-321, ARONIX M-350, ARONIX M-360, ARONIX M-305, ARONIX M-306, ARONIX M-450, ARONIX Examples include M-451, ARONIX M-408, ARONIX M-400, ARONIX M-402, ARONIX M-403, ARONIX M-404, ARONIX M-405, ARONIX M-406 (all manufactured by Toagosei Co., Ltd.), EBECRYL11, EBECRYL145, EBECRYL150, EBECRYL40, EBECRYL140, EBECRYL180, DPGDA, HDDA, TPGDA, HPNDA, PETIA, PETRA, TMPTA, TMPEOTA, DPHA, and the EBECRYL series (all manufactured by Daicel-Scytec Corporation).

[0085] The radical polymerizable compound of the curable composition of the first adhesive layer contains monofunctional (meth)acrylate and polyfunctional (meth)acrylate, and it is preferable that the mass ratio of the polyfunctional (meth)acrylate to the mass of the monofunctional (meth)acrylate is 1.0 or higher. This mass ratio may be 1.2 or higher, 1.4 or higher, 1.6 or higher, or 1.7 or higher. There is no particular upper limit, but it may be 5 or less, or 3 or less. The polyfunctional (meth)acrylate content is preferably 40 parts by mass or more, more preferably 45 parts by mass or more, even more preferably 50 parts by mass or more, particularly preferably 55 parts by mass or more, preferably 75 parts by mass or less, more preferably 70 parts by mass or less, even more preferably 65 parts by mass or less, particularly preferably 60 parts by mass or less, based on 100 parts by mass of the total radical polymerizable compound (e.g., the total of monofunctional (meth)acrylate, polyfunctional (meth)acrylate, and urethane acrylate). When the polyfunctional (meth)acrylate content in the radical polymerizable compound is above the lower limit, not only can the diffusion of components contained in the linear polarizer into the phase difference layer laminate be more effectively suppressed or reduced, but the dependence of the linear polarizer on the external environment to which it is exposed can also be reduced. When the polyfunctional (meth)acrylate content in the radical polymerizable compound is below the upper limit, curling and weakening of the cured layer can be suppressed.

[0086] Radical polymerizable compounds contain two or more functional, particularly three or more functional (and even more particularly five or more functional) polymerizable compounds, which in turn suppresses the migration of dichroic dyes contained in linear polarizers to the phase difference layer laminate. On the other hand, since two or more functional, particularly three or more functional (and even more particularly five or more functional) polymerizable compounds have a bulky structure, measures are usually taken to improve fluidity by adding a solvent to the curable composition in order to obtain a uniform and thin cured layer. However, this added solvent can induce the migration of components contained in linear polarizers to the phase difference layer laminate. When polyfunctional (meth)acrylates are combined with monofunctional (meth)acrylates, the curable composition can have sufficient fluidity even with only a small amount or no solvent added to it, making it easier to obtain a uniform and thin cured layer.

[0087] In the present invention, the content of constituent units derived from polyfunctional (meth)acrylate in the cured layer is preferably 40% by mass or more, more preferably 45% by mass or more, even more preferably 50% by mass or more, particularly preferably 55% by mass or more, preferably 75% by mass or less, more preferably 70% by mass or less, even more preferably 65% ​​by mass or less, particularly preferably 60% by mass or less, with respect to the mass of the polymer constituting the cured layer. When the content is above the lower limit, not only can the diffusion of components contained in the linear polarizer into the phase difference layer laminate be more effectively suppressed or reduced, but the dependence of the linear polarizer on the external environment to which it is exposed can also be reduced. When the content of polyfunctional (meth)acrylate contained in the cured layer is below the upper limit, curling and weakening of the first adhesive layer can be suppressed.

[0088] (Urethane acrylate) Urethane acrylate generally refers to a reaction product of an isocyanate compound, a polyol compound, and an acrylate compound. There is no limit to the number of functional groups in urethane acrylate, i.e., the number of acryloyloxy groups contained in the molecule. The number of functional groups in urethane acrylate may be 2 or less, but it is preferable that the number of functional groups in urethane acrylate be 3 or more, more preferably 4 or more, even more preferably 5 or more, and even more preferably 6 or more. When the number of functional groups in urethane acrylate is 3 or more, the crosslinking density of the cured layer increases, which not only suppresses or reduces the diffusion of components contained in the linear polarizer into the phase difference layer laminate to a higher degree, but also reduces the dependence of the linear polarizer on the external environment to which it is exposed. In addition, it is possible to impart appropriate toughness to the cured layer, which contributes to improving the flexibility of the optical laminate (polarizer) and improving its resistance to deformation due to bending, etc. The number of functional groups in urethane acrylate is usually 10 or less, and from the viewpoint of the coating properties of the curable composition, it is preferably 8 or less. Furthermore, if the curable composition contains two or more types of urethane acrylates, it is preferable that the number of functional groups of all types of urethane acrylates contained in the curable composition is equal to or greater than the lower limit and equal to or less than the upper limit, and the number of functional groups may be the same or different among the urethane acrylates.

[0089] The weight-average molecular weight (Mw) of the urethane acrylate is preferably 300 or more, more preferably 400 or more, preferably 10,000 or less, more preferably 7,000 or less, even more preferably 5,000 or less, and particularly preferably 3,000 or less, in terms of polystyrene. When the Mw of the urethane acrylate is within the above range, the adhesion of the cured layer to adjacent layers and the heat resistance can be further improved. The weight-average molecular weight can be measured, for example, by gel permeation chromatography (GPC).

[0090] Urethane acrylate has 15 × 10¹⁶ acryloyloxy groups per unit molecular weight. -4 Preferably, it is 20 × 10 -4 More preferably, 30 × 10 -4 It is even more preferable that the above be 40 × 10 -4 It is particularly preferable that the values ​​be as described above. If the number of acryloyloxy groups per unit molecular weight is equal to or greater than the lower limit, the adhesion and heat resistance of the cured layer to adjacent layers can be further improved. The upper limit for the number of acryloyloxy groups per unit molecular weight is usually 20 or less. The number of acryloyloxy groups per unit molecular weight can be calculated according to the formula: number of acryloyloxy groups in urethane acrylate / weight-average molecular weight (Mw).

[0091] The radical polymerizable compound preferably contains urethane acrylate with three or more functional groups. The content of urethane acrylate with three or more functional groups in the radical polymerizable compound is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, even more preferably 10 parts by mass or more, particularly preferably 12 parts by mass or more, preferably 40 parts by mass or less, more preferably 33 parts by mass or less, even more preferably 25 parts by mass or less, particularly preferably 20 parts by mass or less, based on 100 parts by mass of the total radical polymerizable compound (e.g., the total of monofunctional (meth)acrylate, polyfunctional (meth)acrylate, and urethane acrylate). When the content of urethane acrylate with three or more functional groups in the radical polymerizable compound is above the lower limit, the diffusion of components contained in the linear polarizer into the phase difference layer laminate can be more effectively suppressed or reduced, and the dependence of the linear polarizer on the external environment to which it is exposed can be reduced. When the content of urethane acrylate in the radical polymerizable compound is below the upper limit, the coatability of the curable composition can be improved, and curling and weakening of the cured layer can be suppressed.

[0092] The mass ratio of monofunctional (meth)acrylate to urethane acrylate in the curable composition [mass of monofunctional (meth)acrylate / mass of urethane acrylate] is preferably 0.5 or more, more preferably 1 or more, even more preferably 1.5 or more, particularly preferably 1.8 or more, preferably 10 or less, more preferably 5 or less, even more preferably 3.5 or less, and particularly preferably 2.8 or less. When the mass ratio is above the lower limit and below the upper limit, the polarizing plate can exhibit better durability even in high-temperature or high-temperature and high-humidity environments, and in particular can achieve both better adhesion and transmittance.

[0093] The mass ratio of polyfunctional (meth)acrylate to urethane acrylate in the curable composition [mass of polyfunctional (meth)acrylate / mass of urethane acrylate] is preferably 0.5 or higher, more preferably 1.2 or higher, even more preferably 2.1 or higher, particularly preferably 2.9 or higher, preferably 26 or lower, more preferably 12 or lower, even more preferably 7.7 or lower, and particularly preferably 5.6 or lower. When the mass ratio is above the lower limit and below the upper limit, the polarizing plate can exhibit better durability even in high-temperature or high-temperature and high-humidity environments, and in particular can achieve both better adhesion and transmittance.

[0094] (Another embodiment of a radical polymerizable compound contained in a curable composition) A radical polymerizable compound contained in a curable composition according to another embodiment is: a) Urethane (meth)acrylates having two or fewer (meth)acryloyl groups in the molecule b) (meth)acrylates that do not have an aromatic ring in the molecule and have a hydroxyl group, c) A mixture of (meth)acrylates that do not have a hydroxyl group in the molecule and have two or more aromatic rings.

[0095] a) Urethane (meth)acrylate having two or fewer (meth)acryloyl groups in its molecule (hereinafter also referred to as "urethane (meth)acrylate (a)") is a polymerizable compound that can function as a base polymer. Urethane (meth)acrylate generally refers to a reaction product of an isocyanate compound, a polyol compound, and a (meth)acrylate compound. Urethane (meth)acrylate (a) has two or fewer (meth)acryloyl groups in its molecule, that is, usually one or two. Having two (meth)acryloyl groups makes it easier to form a crosslinked structure, which improves the adhesion of the cured layer and imparts appropriate toughness. Therefore, it is preferable that urethane (meth)acrylate (a) is a bifunctional urethane (meth)acrylate having two (meth)acryloyl groups in its molecule.

[0096] The urethane (meth)acrylate (a) is not particularly limited as long as it has two or fewer (meth)acryloyl groups in its molecule, and known urethane (meth)acrylate compounds can be used. Specifically, examples include those obtained by reacting a terminal isocyanate urethane prepolymer, which is obtained by reacting a polyol compound such as a polyester type or polyether type with a polyvalent isocyanate compound (e.g., 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc.), with a (meth)acrylate having a hydroxyl group (e.g., 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol (meth)acrylate, etc.). One type of urethane (meth)acrylate (a) may be used, or two or more types may be used in combination. Furthermore, commercially available urethane (meth)acrylate (a) may be used. Note that even if a (meth)acrylate compound having two or fewer (meth)acryloyl groups in its molecule has, for example, a urethane bond and a hydroxyl group, in this specification, as long as it has a urethane bond, it is classified as urethane (meth)acrylate (a).

[0097] The weight-average molecular weight (Mw) of urethane (meth)acrylate (a) is preferably 300 or more, more preferably 400 or more, even more preferably 500 or more, particularly preferably 600 or more, preferably 10,000 or less, more preferably 5,000 or less, even more preferably 3,000 or less, and particularly preferably 2,000 or less, based on polystyrene. When the Mw of urethane (meth)acrylate (a) is within the above range, adhesion to layers adjacent to the cured layer tends to improve. The weight-average molecular weight can be measured, for example, by gel permeation chromatography (GPC).

[0098] The viscosity (at 40°C) of urethane (meth)acrylate (a) is preferably 10,000 to 100,000 mPa·s, more preferably 20,000 to 70,000 mPa·s, and even more preferably 40,000 to 60,000 mPa·s. When the viscosity of urethane (meth)acrylate (a) is within the above range, the viscosity of the curable composition can be easily controlled, and good coating properties can be imparted to the curable composition. The viscosity of urethane (meth)acrylate (a) can be measured, for example, by an E-type viscometer.

[0099] The content of urethane (meth)acrylate (a) in the curable composition is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and even more preferably 5 to 22 parts by mass, based on 100 parts by mass of the total amount of radical polymerizable compounds contained in the curable composition. When the content of urethane (meth)acrylate (a) is within the above range, the adhesion of the resulting cured layer can be improved. In addition, the viscosity of the curable composition can be easily adjusted, and good coating properties can be imparted to the curable composition. When two or more types of urethane (meth)acrylate (a) are included, it is preferable that their total content is within the above range.

[0100] In a curable composition, b) a (meth)acrylate that does not have an aromatic ring in its molecule and has a hydroxyl group (hereinafter also referred to as "hydroxyl group-containing (meth)acrylate (b)") can preferably function as an adhesion imparting agent in the cured layer. The number of hydroxyl groups in the hydroxyl group-containing (meth)acrylate (b) is usually 1 to 3 in the molecule, preferably 1 to 2, and more preferably 1. The number of (meth)acryloyl groups in the hydroxyl group-containing (meth)acrylate (b) may be 1. The hydroxyl group-containing (meth)acrylate (b) is not particularly limited and can be selected and used from known (meth)acrylate compounds containing hydroxyl groups. Specifically, for example, hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 2-hydroxyethyl acryloyl phosphate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, dipropylene glycol (meth)acrylate, fatty acid-modified glycidyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol Examples include pyrene glycol mono(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl(meth)acrylate, glycerin di(meth)acrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, pentaerythritol tri(meth)acrylate, caprolactone-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, caprolactone-modified dipentaerythritol penta(meth)acrylate, and ethylene oxide-modified dipentaerythritol penta(meth)acrylate. As the hydroxyl group-containing (meth)acrylate (b), one type may be used alone, or two or more types may be used in combination.

[0101] The content of hydroxyl group-containing (meth)acrylate (b) in the curable composition is preferably 15 to 60 parts by mass, more preferably 20 to 55 parts by mass, and even more preferably 25 to 50 parts by mass, based on 100 parts by mass of the total amount of radical polymerizable compounds contained in the curable composition. When the content of hydroxyl group-containing (meth)acrylate (b) is within the above range, the adhesion of the resulting cured layer can be improved. Furthermore, an increase in reflectivity can be suppressed in relation to adjacent layers such as phase difference layer laminates. In addition, the viscosity of the curable composition can be easily adjusted, and good coating properties can be imparted to the curable composition. On the other hand, if the content of (meth)acrylate (b) is too low, the adhesion tends to decrease. When two or more types of hydroxyl group-containing (meth)acrylate (b) are included, it is preferable that their total content is within the above range.

[0102] The curable composition contains c) a (meth)acrylate (hereinafter also referred to as "aromatic ring-containing (meth)acrylate (c)") which does not have a hydroxyl group in its molecule and has two or more aromatic rings. When the curable composition contains aromatic ring-containing (meth)acrylate (c), it is excellent in suppressing the decrease in phase difference value under high-temperature conditions in an optical laminate composed of a liquid crystal phase difference layer. The reason for this is not necessarily limited, but is presumed to be as follows: In an optical laminate in which a cured layer and a liquid crystal phase difference layer are adjacent to each other, aromatic ring-containing (meth)acrylate (c) migrates from the cured layer (first adhesive layer) to the liquid crystal phase difference layer. Since aromatic ring-containing (meth)acrylate (c) contains two or more aromatic rings, it is a compound with a relatively high electron density, and therefore, when it migrates to the liquid crystal phase difference layer, it is thought to have the effect of increasing the phase difference value of the liquid crystal phase difference layer. Therefore, it is presumed that the decrease in phase difference value under high-temperature conditions is offset by the increase in phase difference value due to the migration of aromatic ring-containing (meth)acrylate (c) from the cured material layer (first adhesive layer) to the liquid crystal phase difference layer, thereby substantially suppressing the change in phase difference value. Furthermore, aromatic ring-containing (meth)acrylate (c) can also function as a high refractive index agent in the cured material layer (first adhesive layer). This makes it easier to approximate the in-plane average refractive index of the cured material layer with the in-plane average refractive index of the liquid crystal phase difference layer adjacent to the cured material layer (first adhesive layer), and an effect of suppressing interfacial reflection between these layers can be expected.

[0103] The number of aromatic rings in the aromatic ring-containing (meth)acrylate (c) is preferably 2 to 5, more preferably 2 to 3, and even more preferably 2. When the number of aromatic rings in the aromatic ring-containing (meth)acrylate (c) is within the above range, the durability of the resulting optical laminate can be further improved. The number of (meth)acryloyl groups in the aromatic ring-containing (meth)acrylate (c) may be 1.

[0104] The refractive index of the aromatic ring-containing (meth)acrylate (c) is preferably 1.50 to 1.65, more preferably 1.55 to 1.60, and even more preferably 1.57 to 1.59. When the refractive index of the aromatic ring-containing (meth)acrylate (c) is within the above range, its function as a high refractive index agent is sufficiently obtained, and an effect of suppressing the increase in reflectivity in the optical laminate can be expected.

[0105] Examples of aromatic ring-containing (meth)acrylates (c) include ethoxylated-o-phenylphenol acrylate, bisphenol A type epoxy (meth)acrylate, bisphenol F type epoxy (meth)acrylate, 2-([1,1'-biphenyl]-2-yloxy)ethyl acrylate, 3-phenoxybenzyl acrylate, naphthalene-1-ylmethyl acrylate, and 2-(2-([1,1'-biphenyl]-2-yloxy)ethoxy Examples include ethyl acrylate, methyl naphthalene-1-ylmethoxyacrylate, 6-((4'-cyano-[1,1'-biphenyl]-4-yl)oxy)hexyl acrylate, 4-benzoylphenyl acrylate, anthracene-9-ylmethyl acrylate, [1,1'-biphenyl]-4,4'-diyl diacrylate, and 2-((4'-hydroxy-[1,1'-biphenyl]-2-yl)oxy)ethyl acrylate. Among these, ethoxylated-o-phenylphenol acrylate is preferred. These may be used individually or in combination of two or more.

[0106] The content of aromatic ring-containing (meth)acrylate (c) in the curable composition is preferably 10 to 60 parts by mass, more preferably 20 to 55 parts by mass, and even more preferably 25 to 50 parts by mass, based on 100 parts by mass of the total amount of radical polymerizable compounds contained in the curable composition. When the content of aromatic ring-containing (meth)acrylate (c) is within the above range, it is possible to suppress the decrease in the phase difference value in the liquid crystal phase difference layer, and an effect of suppressing the increase in reflectivity and improving adhesion can be expected. On the other hand, if the content of aromatic ring-containing (meth)acrylate (c) is too high, it is likely to cause a decrease in adhesion and a decrease in the phase difference value. When two or more types of aromatic ring-containing (meth)acrylate (c) are included, it is preferable that their total content is within the above range.

[0107] In this embodiment, it is preferable that the curable composition contains each of the above a) to c) in amounts within the ranges described above.

[0108] In one embodiment of the present invention, the mass ratio of urethane (meth)acrylate (a) to hydroxyl group-containing (meth)acrylate (b) in the curable composition (urethane (meth)acrylate (a) / hydroxyl group-containing (meth)acrylate (b)) is preferably 0.05 to 1.0, more preferably 0.1 to 0.9, and even more preferably 0.1 to 0.8. When the mass ratio of urethane (meth)acrylate (a) to hydroxyl group-containing (meth)acrylate (b) is within the above range, good coating properties can be obtained, and the adhesion of the resulting adhesive layer tends to improve.

[0109] In one embodiment of the present invention, the mass ratio of urethane (meth)acrylate (a) to aromatic ring-containing (meth)acrylate (c) in the curable composition (urethane (meth)acrylate (a) / aromatic ring-containing (meth)acrylate (c)) is preferably 0.05 to 1.2, more preferably 0.1 to 1.0, and may be, for example, 0.5 to 1.0. When the mass ratio of urethane (meth)acrylate (a) to aromatic ring-containing (meth)acrylate (c) is within the above range, it is possible to achieve excellent suppression of the decrease in the phase difference value in the liquid crystal phase difference film, as well as expect even higher suppression of reflectivity increase and improved adhesion.

[0110] In one embodiment of the present invention, the mass ratio of hydroxyl group-containing (meth)acrylate (b) to aromatic ring-containing (meth)acrylate (c) in the curable composition (hydroxyl group-containing (meth)acrylate (b) / aromatic ring-containing (meth)acrylate (c)) is preferably 0.5 to 2.0, more preferably 0.6 to 1.8, and even more preferably 0.6 to 1.7. When the mass ratio of hydroxyl group-containing (meth)acrylate (b) to aromatic ring-containing (meth)acrylate (c) is within the above range, good coating properties can be obtained, and it becomes easier to obtain an effect of suppressing the decrease in the phase difference value in the liquid crystal phase difference film and an effect of improving adhesion.

[0111] In one embodiment of the present invention, the curable composition preferably further contains d) a (meth)acrylate having at least one aromatic ring and at least one hydroxyl group in its molecule (hereinafter also referred to as "hydroxyl group and aromatic ring-containing (meth)acrylate (d)"). The hydroxyl group and aromatic ring-containing (meth)acrylate (d) can preferably function as a refractive index modifier in the cured layer (first adhesive layer). The number of hydroxyl groups in the hydroxyl group and aromatic ring-containing (meth)acrylate (d) is usually 1 to 3 in the molecule, preferably 1 to 2, and more preferably 1. The number of aromatic rings is 1 to 3, preferably 1 to 2, and more preferably 1. By using a (meth)acrylate that has a good balance of hydroxyl groups and aromatic rings, the refractive index of the resulting cured layer can be easily controlled, and the effect of suppressing interfacial reflection between layers is excellent.

[0112] The hydroxyl group and aromatic ring-containing (meth)acrylate (d) is not particularly limited and can be selected from known (meth)acrylate compounds containing a hydroxyl group and an aromatic ring. Specifically, examples include 4-hydroxyphenyl acrylate, 3-hydroxyphenyl acrylate, 2-hydroxyphenyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-4-phenoxybutyl acrylate, 2-hydroxy-5-phenoxypentyl acrylate, 3-hydroxy-4-phenoxybutyl acrylate, 4-hydroxy-5-phenoxypentyl acrylate, 2-hydroxy-3-(p-tolyloxy)propyl acrylate, 2-hydroxy-3-(m-tolyloxy)propyl acrylate, 2-hydroxy-3-(o-tolyloxy)propyl acrylate, 3-hydroxy-2-phenylpropyl acrylate, 4-hydroxy-2-phenylbutyl acrylate, and 4-hydroxy-3-phenylbutyl acrylate. These may be used individually or in combination of two or more. Furthermore, the hydroxyl group and aromatic ring-containing (meth)acrylate (d) may be a commercially available product.

[0113] The refractive index of the hydroxyl group and aromatic ring-containing (meth)acrylate (d) is preferably 1.50 to 1.65, more preferably 1.50 to 1.60, and even more preferably 1.52 to 1.59. When the refractive index of the hydroxyl group and aromatic ring-containing (meth)acrylate (d) is within the above range, it is easier to fully perform its function as a refractive index adjusting agent, and an effect of suppressing the increase in reflectivity in the optical laminate can be expected.

[0114] When the curable composition contains a hydroxyl group and aromatic ring-containing (meth)acrylate (d), its content is preferably 3 to 40 parts by mass, more preferably 5 to 35 parts by mass, and even more preferably 10 to 30 parts by mass, based on 100 parts by mass of the total amount of radical polymerizable compounds contained in the curable composition. When the content of the hydroxyl group and aromatic ring-containing (meth)acrylate (d) is within the above range, an effect of suppressing the increase in reflectivity and improving adhesion can be expected. In addition, the viscosity of the curable composition can be easily adjusted, and good coating properties can be imparted to the curable composition. When two or more types of hydroxyl group and aromatic ring-containing (meth)acrylate (d) are included, it is preferable that their total content be within the above range.

[0115] In one embodiment of the present invention, when the curable composition contains a hydroxyl group and aromatic ring-containing (meth)acrylate (d), the mass ratio of urethane (meth)acrylate (a) to hydroxyl group and aromatic ring-containing (meth)acrylate (d) (urethane (meth)acrylate (a) / hydroxyl group and aromatic ring-containing (meth)acrylate (d)) is preferably 0.2 to 1.0, more preferably 0.3 to 1.0, and even more preferably 0.5 to 0.9. When the mass ratio of urethane (meth)acrylate (a) to hydroxyl group and aromatic ring-containing (meth)acrylate (d) is within the above range, an effect of suppressing the increase in reflectivity and an effect of improving adhesion can be expected, as well as good coating properties can be obtained.

[0116] In one embodiment of the present invention, when the curable composition contains a hydroxyl group and aromatic ring-containing (meth)acrylate (d), the mass ratio of the hydroxyl group-containing (meth)acrylate (b) to the hydroxyl group and aromatic ring-containing (meth)acrylate (d) (hydroxyl group-containing (meth)acrylate (b) / hydroxyl group and aromatic ring-containing (meth)acrylate (d)) is preferably 0.3 to 3.0, more preferably 0.6 to 2.0. When the mass ratio of the hydroxyl group-containing (meth)acrylate (b) to the hydroxyl group and aromatic ring-containing (meth)acrylate (d) is within the above range, an effect of suppressing the increase in reflectivity and an effect of improving adhesion can be expected, as well as good coating properties can be obtained.

[0117] In one embodiment of the present invention, when a hydroxyl group and aromatic ring-containing (meth)acrylate (d) is included, the mass ratio of aromatic ring-containing (meth)acrylate (c) to hydroxyl group and aromatic ring-containing (meth)acrylate (d) (aromatic ring-containing (meth)acrylate (c) / hydroxyl group and aromatic ring-containing (meth)acrylate (d)) is preferably 0.5 to 6.0, more preferably 0.6 to 5.0. When the mass ratio of aromatic ring-containing (meth)acrylate (c) to hydroxyl group and aromatic ring-containing (meth)acrylate (d) is within the above range, it is possible to achieve excellent suppression of the decrease in the phase difference value in the liquid crystal phase difference film, as well as expect even higher suppression of reflectivity increase and improved adhesion.

[0118] The curable composition of this alternative embodiment may contain other radical polymerizable compounds other than radical polymerizable compounds a) to d). Examples of such other radical polymerizable compounds include urethane (meth)acrylates having three or more (meth)acryloyl groups in the molecule, (meth)acrylates that do not have hydroxyl groups in the molecule and have one aromatic ring, and monofunctional or polyfunctional (meth)acrylates that do not contain hydroxyl groups or aromatic rings in the molecule.

[0119] If the curable composition contains radical polymerizable compounds other than radical polymerizable compounds a) to d), the content thereof is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, in total, per 100 parts by mass of the total amount of radical polymerizable compounds contained in the curable composition, with a lower limit of 0 parts by mass. When the content of radical polymerizable compounds other than radical polymerizable compounds a) to d) is within the above range, the effects obtained by radical polymerizable compounds a) to c) and optionally d) can be sufficiently ensured. If two or more other radical polymerizable compounds other than radical polymerizable compounds a) to d) are included, their total content is within the above range. In a preferred embodiment of the present invention, the curable composition does not contain radical polymerizable compounds other than radical polymerizable compounds a) to d).

[0120] (solvent) The curable composition may contain a solvent. The solvent content in the curable composition is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0% by mass, based on the total mass of the curable composition. When the solvent content in the curable composition is below the above upper limit, the solvent content in the first adhesive layer can be kept low without performing a drying step when manufacturing the optical laminate according to one embodiment of the present invention. This prevents a decrease in the polarization performance of the linear polarizer caused by the drying step, and further suppresses the decrease in the polarization performance of the optical laminate over time. The solvent content in the curable composition is particularly preferably 0% by mass (preferably 5% by mass or less), but because the disclosed curable composition has good fluidity, a uniform and thin coating film can be obtained even if the curable composition does not contain a solvent (or contains only a small amount of solvent). The lower limit of the solvent content in the curable composition is 0% by mass or more, based on the total mass of the curable composition.

[0121] Examples of usable solvents include any solvent capable of dissolving the components constituting the curable composition, such as aliphatic hydrocarbons like hexane and octane; aromatic hydrocarbons like toluene and xylene; alcohols like ethanol, 1-propanol, isopropanol, and 1-butanol; ketones like methyl ethyl ketone and methyl isobutyl ketone; esters like ethyl acetate, butyl acetate, and isobutyl acetate; glycol ethers like ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; and esterified glycol ethers like ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate. These solvents can be used individually or in combination of two or more.

[0122] The curable composition may optionally contain one or more additives commonly used in curable compositions. Examples of such additives include polymerization initiators, sensitizers, polymerization inhibitors, leveling agents, reactive additives, ion trapping agents, antioxidants, chain transfer agents, polymerization accelerators (such as polyols), sensitizing aids, light stabilizers, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, defoamers, silane coupling agents, dyes, antistatic agents, and ultraviolet absorbers.

[0123] (Polymerization initiator) The curable composition may contain a polymerization initiator. The polymerization initiator is a compound that can initiate the polymerization reaction of radical polymerizable compounds such as monofunctional (meth)acrylates, polyfunctional (meth)acrylates, and urethane acrylates. As the polymerization initiator, a photopolymerization initiator that generates active radicals upon the action of light is preferred. Examples of light include ultraviolet light.

[0124] Examples of polymerization initiators include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts, and sulfonium salts. Polymerization initiators can be used individually or in combination of two or more.

[0125] Examples of benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

[0126] Examples of benzophenone compounds include benzophenone, o-methyl benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, and 2,4,6-trimethylbenzophenone.

[0127] Examples of alkylphenone compounds include diethoxyacetophenone, 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexylphenyl ketone, and oligomers of 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one.

[0128] Examples of acylphosphine oxide compounds include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0129] Examples of triazine compounds include 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxynaphthyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-triazine, and 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2-yl)ethenyl Examples include triazines such as 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)ethenyl]-1,3,5-triazine, and 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)ethenyl]-1,3,5-triazine.

[0130] Commercially available polymerization initiators can also be used. Examples of commercially available polymerization initiators include Irgacure® 907, 184, 651, 819, 250, and 369 (manufactured by Ciba Specialty Chemicals Co., Ltd.); Omnirad 819, Omnirad 907, Esacure 1001M, Esacure KIP160 (manufactured by IDM Resins BV); Seiko Chemicals® BZ, Z, and BEE (manufactured by Seiko Chemicals Ltd.); Kayacure® BP100 and UVI-6992 (manufactured by Dow Chemical Ltd.); Adeka Optomer SP-152 and SP-170 (manufactured by ADEKA Corporation); TAZ-A and TAZ-PP (manufactured by Nippon Siber Hegner Co., Ltd.); TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.).

[0131] If the curable composition contains a polymerization initiator, its content can be appropriately selected depending on the type and amount of the radical polymerizable compound. From the viewpoint of initiator efficiency, the amount is usually 0.1 to 40 parts by mass, preferably 0.2 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, per 100 parts by mass of the total mass of the radical polymerizable compound contained in the curable composition.

[0132] If the curable composition contains a leveling agent, its content is preferably 0 to 6 parts by mass, more preferably 0.01 to 5 parts by mass, even more preferably 0.05 to 5 parts by mass, and particularly preferably 0.08 to 3 parts by mass, based on 100 parts by mass of the total mass of polymerizable compounds contained in the composition for forming the first adhesive layer, from the viewpoint of the smoothness of the resulting first adhesive layer. The leveling agent can be used alone or in combination of two or more types.

[0133] The viscosity of the first adhesive layer forming composition is preferably 300 mPa·s or less, more preferably 280 mPa·s or less, and even more preferably 250 mPa·s or less at 25°C. When the viscosity is below the upper limit, the fluidity of the curable composition is even better, so that the curable composition can be uniformly and thinly applied to a linear polarizer or a resin film or surface treatment layer described later, a first adhesive layer of even more uniform thickness and thinness can be obtained, and the pump transportability of the curable composition in the polarizer manufacturing process is excellent. The lower limit of the viscosity of the curable composition at 25°C is usually 5 cps or more. The viscosity can be measured according to JIS K7367. In a preferred embodiment, the viscosity of the curable composition is below the upper limit when the solvent content in the curable composition is within the above range.

[0134] The solid content of the curable composition is preferably 95% by mass or more, more preferably 97% by mass or more, even more preferably 99% by mass or more, and particularly preferably 100% by mass, based on the mass of the curable composition. If the solid content is above the lower limit, a first adhesive layer with even more uniform thickness and thinness can be obtained without performing a drying step after coating the curable composition. The amount of components other than radical polymerizable compounds and polymerization initiators in the solid content of the curable composition may be 30% by mass or less, 20% by mass or less, or 10% by mass or less.

[0135] (Tensile modulus of the first adhesive layer) The tensile modulus of the first adhesive layer, measured at 23°C, is preferably 100 MPa or higher, may be 200 MPa or higher, may be 500 MPa or higher, and is also preferably 1000 MPa or higher. The tensile modulus of the first adhesive layer, measured at 23°C, may be 5000 MPa or lower. If this tensile modulus is too low, it tends to be less effective in inhibiting iodine movement. On the other hand, if this tensile modulus is too high, it tends to crack easily after durability testing or during bending.

[0136] (Method of bonding by curing of a curable composition) Bonding with 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 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 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.

[0137] 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 photoradical 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.

[0138] 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.

[0139] (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.

[0140] (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.

[0141] 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.

[0142] 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.

[0143] Each liquid crystal phase difference layer may be positive wavelength dispersive or negative wavelength dispersive.

[0144] 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.

[0145] 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.

[0146] The transmittance of the phase difference layer laminate 300 at 311 nm is preferably 8% or higher.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] (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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] (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).

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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.)

[0160] 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.

[0161] <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.

[0162] 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):

[0163] [ka] Examples of compounds represented by [the formula shown] are given.

[0164] 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-.

[0165] 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.

[0166] L 1 , L 2 、 B 1 and B 2 Each of these is independently a single bond or a divalent linking group.

[0167] 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.

[0168] 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.

[0169] 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.

[0170] 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.

[0171] 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-.

[0172] 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 further preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, -OCO-, or -OCOCH2CH2-.

[0173] k and l are preferably in the range of 2 ≦ k + l ≦ 6, more preferably k + l = 4, and even more preferably k = 2 and l = 2, from the viewpoint of expressing inverse wavelength dispersion. When k = 2 and l = 2, it is preferable because it has a symmetric structure.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] Examples of aromatic groups represented by Ar include the following:

[0179] [ka]

[0180] 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.

[0181] Q 1 , and Q 2 These are, independently, -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.

[0182] J 1 , and J 2 Each of these independently represents either a carbon atom or a nitrogen atom.

[0183] Y 1 , and Y 2 Each of these independently represents an optionally substituted aromatic hydrocarbon group or an aromatic heterocyclic group.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] Among formulas (Ar-1) to (Ar-23), formulas (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] [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.

[0194] 100nm <Re(550)<160nm (QL1) 200nm <Re(550)<320nm (QL2) Re(450) / Re(550)≧1.00 (QL3) 1.00 ≥ Re(650) / Re(550) (QL4)

[0195] 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.

[0196] 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°.

[0197] 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).

[0198] [ka]

[0199] 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.

[0200] 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 contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group or a nitro group, and the hydrogen atoms contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom.

[0201] B11 represents -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR 16 -, -NR 16 -, -CO-, -CO-, -CS- or a single bond. R 16 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0202] B12 and B13 each independently represent -C≡C-, -CH=CH-, -CH2-CH2-, -O-, -S-, -C(=O)-, -C(=O)-O-, -O-C(=O)-, -O-C(=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-, -O-C(=O)-CH=CH- or a single bond.

[0203] E11 represents an alkanediyl group having 1 to 12 carbon atoms. The hydrogen atoms contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and the hydrogen atoms contained in the alkoxy group may be substituted with a halogen atom. Further, -CH2- constituting the alkanediyl group may be replaced with -O- or -CO-.

[0204] 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, a cyclohexane-1,4-diyl group and a 1,4-phenylene group are preferred.

[0205] As E11, a linear alkanediyl group having 1 to 12 carbon atoms is preferred. The -CH2- constituting the alkanediyl group may be replaced by -O-.

[0206] Specifically, 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; -CH2-CH2-O-CH2-CH2-, -CH2-CH2-O-CH2-CH2-O-CH2-CH2- and -CH2-CH2-O-CH2-CH2-O-CH2-CH2-O-CH2-CH2- etc. may be mentioned.

[0207] As B11, -O-, -S-, -CO-O-, -O-CO- are preferred, and among them, -CO-O- is more preferred.

[0208] As B12 and B13, each independently, -O-, -S-, -C(=O)-, -C(=O)-O-, -O-C(=O)-, -O-C(=O)-O- are preferred, and among them, -O- or -O-C(=O)-O- is more preferred.

[0209] <000092A>As the polymerizable group represented by P'11, from the viewpoint of high polymerization reactivity, particularly high photopolymerization reactivity, a radical polymerizable group or a cationic polymerizable group is preferred. Also, since it is easy to handle and the production of the liquid crystal compound itself is easy, the polymerizable group is preferably a group represented by the following formulas (P-11) to (P-15).

[0210] [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.

[0211] 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.

[0212] [ka]

[0213] 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.

[0214] It is even more preferable that the group represented by P11-B11- is an acryloyloxy group or a methacryloyloxy group.

[0215] (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-.

[0216] [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.

[0217] <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)

[0218] 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.

[0219] 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.

[0220] 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.

[0221] 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 - 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-.)

[0222] 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 the present 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.

[0223] <Composition for forming a liquid crystal retardation layer> 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 as needed on a substrate, and then polymerizing and curing the polymerizable liquid crystal compound in an oriented state.

[0224] [Orientation film and composition for forming orientation film] The alignment film has an orientation-regulating force that causes polymerizable liquid crystal compounds to be liquid crystal oriented in a desired direction.

[0225] Alignment films facilitate the liquid crystal alignment of polymerizable liquid crystal compounds. The state of liquid crystal alignment, such as horizontal alignment, vertical alignment, hybrid alignment, and tilted alignment, changes depending on the properties of the alignment film and the polymerizable liquid crystal compound, and any combination can be arbitrarily selected. For example, if the alignment film is a material that exhibits horizontal alignment as an alignment restricting force, the polymerizable liquid crystal compound can form horizontal alignment or hybrid alignment. If the material exhibits vertical alignment, the polymerizable liquid crystal compound can form vertical alignment or tilted alignment. Expressions such as horizontal and vertical refer to the direction of the optical axis of the oriented polymerizable liquid crystal compound with respect to the optical anisotropy layer plane. For example, vertical alignment means that the optical axis of the oriented polymerizable liquid crystal compound is perpendicular to the optical anisotropy layer plane. Here, perpendicular means 90° ± 20° with respect to the optical anisotropy layer plane.

[0226] The orientation-regulating force can be arbitrarily adjusted by surface conditions and rubbing conditions if the orientation film is formed from an orientation-oriented polymer, and by polarization irradiation conditions, etc., if it is formed from a photo-oriented polymer. Furthermore, liquid crystal orientation can also be controlled by selecting physical properties such as surface tension and liquid crystalline properties of the polymerizable liquid crystal compound.

[0227] 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.

[0228] 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.

[0229] 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.

[0230] 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.

[0231] 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.

[0232] 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).

[0233] 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.

[0234] 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.

[0235] 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.

[0236] (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.

[0237] 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.

[0238] <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.

[0239] 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.

[0240] The solvent content is preferably 50 to 98% by mass relative to the total amount of the liquid crystal phase difference layer forming composition. In other words, the solid content in the liquid crystal phase difference layer forming composition is preferably 2 to 50% by mass, and more preferably 5 to 30% by mass. When the solid content is 50% by mass or less, the viscosity of the liquid crystal phase difference layer forming composition decreases, resulting in a more uniform thickness of the liquid crystal phase difference layer, which tends to reduce unevenness in the liquid crystal phase difference layer. Furthermore, the solid content can be determined considering the thickness of the optical anisotropy layer to be manufactured.

[0241] <Leveling agent> The liquid crystal phase difference layer forming composition may contain a leveling agent. A leveling agent is an additive that adjusts the fluidity of the composition and makes the film obtained by coating the composition flatter. Examples include silicone-based leveling agents, acrylic-based leveling agents, and fluorine-based leveling agents. Among these, silicone-based leveling agents and fluorine-based leveling agents are preferred because they have excellent function in reducing the tension of the film surface obtained by coating the composition.

[0242] Examples of silicone-based leveling agents include leveling agents having a polyorganosiloxane skeleton.

[0243] Examples of groups bonded to silicon atoms (silicon atoms forming siloxane bonds) in polyorganosiloxanes include hydrocarbon groups. Silicone-based leveling agents may have two hydrocarbon groups bonded to a silicon atom. There are no limitations on the groups bonded to the silicon atom, but alkyl groups and aryl groups having 1 to 10 carbon atoms are preferred, more preferably methyl groups and phenyl groups, and even more preferably methyl groups. The group bonded to the silicon atom may be one type or two or more types. Furthermore, the number of repeating siloxane units (degree of polymerization) is not particularly limited, but is preferably 2 to 10,000, more preferably 3 to 5,000, and even more preferably 5 to 1,000.

[0244] 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.

[0245] 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.

[0246] 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.

[0247] 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.

[0248] 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.).

[0249] 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.

[0250] 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.

[0251] <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.

[0252] 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.

[0253] 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.

[0254] 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.

[0255] <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.

[0256] 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.

[0257] <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.

[0258] 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.

[0259] 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.

[0260] <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.

[0261] (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.

[0262] 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.

[0263] 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.

[0264] 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.

[0265] 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.

[0266] 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.

[0267] 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.

[0268] 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.

[0269] 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.

[0270] 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.

[0271] 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.

[0272] (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.

[0273] 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.

[0274] 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.

[0275] 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).

[0276] (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 liquid crystal phase difference layer 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.

[0277] (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.

[0278] (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.

[0279] If the first adhesive layer 150 is a cured layer of a curable composition containing a radical 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.

[0280] 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.

[0281] 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. When the thickness of the first adhesive layer is thinned to 2.5 μm or less, interference unevenness is further suppressed because variations in optical path difference caused by thickness unevenness of the adhesive layer are suppressed.

[0282] 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.

[0283] <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.

[0284] 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.

[0285] 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]

[0286] 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.

[0287] <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.

[0288] <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.

[0289] <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.

[0290] <Preparation of the curable composition (1)> The following components were mixed and then degassed to prepare a curable composition (1). (Radical polymerizable compounds) • Polyfunctional acrylate (product name: A-9550, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.): 56 parts by mass [ka] However, a through f are 0. • 4-hydroxybutyl acrylate (product name: 4-HBA, manufactured by Osaka Organic Chemical Industry Co., Ltd.): 30 parts by mass • Urethane acrylate (product name: Shiko UV-7605B, Mitsubishi Chemical Corporation) (number of functional groups: 6): 14 parts by mass (Photoradical polymerization initiator) • Radical polymerization initiator (product name: Omnirad 819, manufactured by IGM Resins BV: 3.0 parts by mass)

[0291] <Preparation of curable composition (2)> After mixing the following components, the mixture was degassed to prepare a curable composition (2). • Urethane acrylate oligomer (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name "UA-122P"): 20 parts by mass 4-Hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "4-HBA": 2 functional groups): 35 parts by mass • Ethoxylated-o-phenylphenol acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name "A-LEN-10"): 45 parts by mass • Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by IGM Corporation, trade name "Omnirad819"): 3 parts by mass

[0292] <Preparation of curable composition (3)> After mixing the following components, the mixture was degassed to prepare an active energy ray curing adhesive (3). [Cationically polymerizable compounds] • Neopentyl glycol diglycidyl ether (product name: EX-211L, manufactured by Nagase ChemteX Corporation) 30 parts by mass • 3-Ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane (trade name: OXT-221, manufactured by Toagosei Co., Ltd.) 13 parts by mass • 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 [Photocationic polymerization initiator] • CPI-100P, manufactured by Sunapro Co., Ltd., 50% propylene carbonate solution, 2.25 parts by mass (solid content) [Photosensitizer] • 1,4-Diethoxynaphthalene 1 part by mass The in-plane average refractive index of the cured product of the curable composition (3) was 1.54.

[0293] <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.

[0294] (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]

[0295] (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> · Use of an H bulb of a Fusion UV lamp system (manufactured by Fusion UV Systems) · Integrated light quantity: 250 mJ / cm2

[0296] (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.

[0297] (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).

[0298] (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.

[0299] (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.

[0300] <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.

[0301] <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).

[0302] (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]

[0303] (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.

[0304] Polymerizable liquid crystal compound (A1): [ka]

[0305] Polymerizable liquid crystal compound (A2): [ka]

[0306] (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.

[0307] [Table 1]

[0308] Ionic compounds (B): [ka]

[0309] (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.

[0310] [Table 2]

[0311] Polymerizable liquid crystal compound LC242: [ka]

[0312] <Fabrication of the first liquid crystal phase difference layer film (Z1)> An oriented 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), forming an oriented polymer film with a thickness of 100 nm after heat 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 phase axis of the first liquid phase difference layer (X1) to be formed below, and then a liquid phase difference layer forming composition (Y1) was applied 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, a high-pressure mercury lamp (UniCure VB-15201BY-A, manufactured by Ushio Inc.) was used to expose the film to a nitrogen atmosphere at an exposure dose of 1000 mJ / cm². 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.

[0313] <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.

[0314] <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%.

[0315] <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) were subjected to corona treatment at a rate of 28 kJ / m2. The cured adhesive (3) was applied to the first liquid crystal phase difference layer (X1) of the first liquid crystal phase difference layer film (Z1) to a thickness of 2 μm. Then, the second liquid crystal phase difference layer (X2) surface of the second liquid crystal phase difference layer film (Z2) was laminated onto the adhesive (3) coating. The adhesive (3) was cured by irradiating it with ultraviolet light from the second liquid crystal phase difference layer film (Z2) side, obtaining a phase difference layer laminate 2 in which TAC / alignment film / first liquid crystal phase difference layer (X1) / adhesive layer (3) / second liquid crystal phase difference layer (X2) / alignment film / TAC was laminated in this order. The ultraviolet light used was UVA with wavelengths 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.

[0316] (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 curable 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 coating of curable composition (1) 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 curable 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 a wavelength 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:

[0317] (Example 2) The first adhesive layer was prepared in the same manner as in Example 1, except that curable composition (2) was cured instead of curable composition (1) to form adhesive layer (2).

[0318] (Example 3) 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.

[0319] (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 0.15 μm.

[0320] (Example 5) The procedure was the same as in Example 1, except that the thickness of the first adhesive layer was set to 1.0 μm.

[0321] (Example 6) The procedure was the same as in Example 1, except that the thickness of the first adhesive layer was set to 1.2 μm.

[0322] (Example 7) The procedure was the same as in Example 1, except that the thickness of the first adhesive layer was set to 1.5 μm.

[0323] (Example 8) The procedure was the same as in Example 1, except that the thickness of the first adhesive layer was set to 3.0 μm.

[0324] (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 fabricated so 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). 2Corona treatment was performed under the following conditions. A water-based adhesive coating 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 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.

[0325] (Comparative Example 2) The separator film 1 was peeled from the adhesive sheet (1), and the adhesive layer (1) side 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. 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, the first liquid crystal phase difference layer (X1) was subjected to corona treatment at a rate of 28 kJ / m2. 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). This resulted in 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.

[0326] (Comparative Example 3) The procedure was the same as in Example 1, except that a curable composition (3) was cured to form the adhesive layer (3) as the second adhesive layer. The thickness of the second adhesive layer was 2 μm.

[0327] (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.

[0328] (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.

[0329] <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.

[0330] <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.

[0331] <Rating> (Evaluation of interference 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.

[0332] (Durability evaluation of optical laminates (iodine loss)) 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)

[0333] Table 3 shows the compositional characteristics of the curable compositions (1) and (2). Tables 4 and 5 show the conditions and results.

[0334] (Method for measuring tensile modulus) An adhesive composition was applied to one side of a 50 μm thick cyclic polyolefin resin film using a coating machine (a bar coater manufactured by Daiichi Rika Co., Ltd.) to a thickness of 5 μm after drying. Next, a high-pressure mercury lamp manufactured by Heraeus was used to apply an integrated UVB light intensity of 400 mJ / cm². 2 The adhesive was cured by irradiating it with ultraviolet light in an atmosphere at a temperature of 25°C and a relative humidity of 60% RH, so that the measurement value (measured using a UV Power Puck II manufactured by FusionUV) would be obtained. This was then cut into pieces measuring 10 mm x 100 mm, and the cyclic polyolefin resin film was peeled off to obtain the cured adhesive film. Next, the test piece was clamped at both ends in the long side direction using the upper and lower grips of a tensile testing machine ("Autograph AG-1S testing machine" manufactured by Shimadzu Corporation) with a gap of 5 cm between the grips, and the test piece was pulled in the long side direction at a tensile speed of 1 mm / min in an environment of 23°C. The tensile modulus of elasticity at 23°C [MPa] was calculated from the slope of the initial straight line in the obtained stress-strain curve. The tensile moduli of curable compositions (1) and (2) at 23°C were 3000 MPa and 40 MPa, respectively.

[0335] [Table 3]

[0336] [Table 4]

[0337] [Table 5] [Explanation of Symbols]

[0338] 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 first protective layer, linear polarizer, first adhesive layer, and phase difference layer laminate are provided in this order. The first adhesive layer is a cured layer of a curable composition containing a radical 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 a urethane acrylate having three or more functional groups.

4. The optical laminate according to claim 1 or 2, wherein the curable composition of the first adhesive layer comprises a monofunctional (meth)acrylate and a polyfunctional (meth)acrylate, and the mass ratio of the polyfunctional (meth)acrylate to the mass of the monofunctional (meth)acrylate is 1.0 or more.

5. The optical laminate according to claim 1 or 2, wherein the first adhesive layer has a tensile modulus of 100 MPa or more at 23°C.

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

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

8. 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.

9. 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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