Polarizing laminate

Abstract

To provide a polarizing laminate excellent in durability.SOLUTION: The present invention relates to a polarizing laminate sequentially including a linear polarizer, a second adhesive layer, a first liquid crystal retardation layer, a first adhesive layer, and a second liquid crystal retardation layer. At least one or both of the first and second liquid crystal retardation layers contain Si atoms. The atomic concentration of Si atoms on a surface on the first adhesive layer side in at least one liquid crystal retardation layer containing Si atoms is higher than the atomic concentration of Si atoms at a position 10 nm from the surface on the side of the first adhesive layer in the stacking direction of the polarizing laminate in the liquid crystal retardation layer. The second adhesive layer has a storage elastic modulus of 0.03 MPa or more at 23°C and 1 Hz.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a polarizing laminate. [Background technology]

[0002] BACKGROUND ART Conventionally, a polarizing laminate including a linear polarizer, an attachment layer, a first liquid crystal retardation layer, and a second liquid crystal retardation layer in this order has been known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-151852 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional polarizing laminates have room for improvement in durability in a crosshatch test.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide a polarizing laminate having excellent durability. [Means for solving the problem]

[0006] [1] A polarizing laminate including a linear polarizer, a second bonding layer, a first liquid crystal retardation layer, a first bonding layer, and a second liquid crystal retardation layer in this order, at least one or both of the first liquid crystal retardation layer and the second liquid crystal retardation layer contains Si atoms, the atomic concentration of Si atoms on the surface of the liquid crystal retardation layer on the side of the first bonding layer, which contains Si atoms, is higher than the atomic concentration of Si atoms at a point 10 nm from the surface of the liquid crystal retardation layer on the side of the first bonding layer in the lamination direction of the polarizing laminate; A polarizing laminate, wherein the second attaching layer has a storage modulus of 0.03 MPa or more at 23°C and 1 Hz. [2] The polarizing laminate according to [1], wherein the atomic concentration of Si atoms on the surface of the first bonding layer side in at least one of the liquid crystal retardation layers containing Si atoms is 0.5 at % or more and 10 at % or less. [3] A polarizing laminate according to [1] or [2], wherein the atomic concentration of Si atoms at a point 10 nm from the surface on the first bonding layer side in the stacking direction of the polarizing laminate in at least one of the liquid crystal retardation layers containing Si atoms is less than 0.5 at%. [1A] The optical laminate of [1], wherein the atomic concentration of Si atoms on the surface of the liquid crystal retardation layer on the side of the first bonding layer containing each Si atom is greater than the atomic concentration of Si atoms at a point 10 nm from the surface of the liquid crystal retardation layer on the side of the first bonding layer in the lamination direction of the polarizing laminate. [2A] The polarizing laminate according to [1A], wherein the atomic concentration of Si atoms on the surface of the first bonding layer side in each liquid crystal retardation layer containing Si atoms is 0.5 at % or more and 10 at % or less. [3A] A polarizing laminate according to [1A] or [2A], wherein the atomic concentration of Si atoms in the liquid crystal retardation layer containing each Si atom at a point 10 nm from the surface on the first bonding layer side in the stacking direction of the polarizing laminate is less than 0.5 at%. [4] The polarizing laminate according to any one of [1] to [3], wherein both the first liquid crystal retardation layer and the second liquid crystal retardation layer contain Si atoms. [5] The polarizing laminate according to any one of [1] to [3], wherein the first attaching layer contains F atoms and / or Si atoms. [6] The polarizing laminate according to any one of [1] to [5], wherein the first attaching layer contains Si atoms. [7] The polarizing laminate according to any one of [1] to [6], wherein the relationship between the following formulas (1) and (2) is satisfied: 100≦Re(550)≦180 (1) Re(450) / Re(550)≦1.00 (2) [In formula (1) and formula (2), Re(450) represents the in-plane retardation value (nm) of the polarizing laminate for light with a wavelength of 450 nm; Re(550) represents the in-plane retardation value (nm) of the polarizing laminate for light with a wavelength of 550 nm. [8] The polarizing laminate according to any one of [1] to [7], further comprising a protective layer between the linear polarizer and the second attaching layer, the protective layer having a thickness of 30 μm or less. [9] The polarizing laminate according to any one of [1] to [8], wherein the linear polarizer has a luminous transmittance Ty of 41.5% or more.

[10] The polarizing laminate according to any one of [1] to [9], further comprising an outer adhesive layer on the opposite side of the second liquid crystal retardation layer from the first attaching layer, wherein the outer adhesive layer contains a silane compound.

[11] An image display device comprising the polarizing laminate according to [1] or [2] and an image display cell. [Effects of the Invention]

[0007] According to the present invention, a polarizing laminate having excellent durability is provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of a polarizing laminate 400. As shown in FIG. [Figure 2] FIG. 2 is a schematic cross-sectional view showing another embodiment of a polarizing laminate 400. As shown in FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view showing one embodiment of the optical laminate 100. As shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Polarizing laminate (circular polarizing plate) 400) As shown in FIG. 1, the polarizing laminate 400 according to the embodiment includes a polarizing plate 200, a second bonding layer 150, and a retardation layer laminate 300, and can function as a circular polarizing plate.

[0010] (Polarizing plate 200) The polarizing plate 200 has a linear polarizer 220, a first protective layer 180 provided on one side of the linear polarizer 220, and a second protective layer 190 provided on the opposite side. The protective layer may be provided on only one side. In this embodiment, the second protective layer 190 is on the second bonding layer 150 side, and the first protective layer 180 is on the opposite side of the second bonding layer 150.

[0011] (Linear polarizer 220) A linear polarizer has the function of selectively transmitting linearly polarized light in a certain direction from unpolarized light such as natural light. Examples of linear polarizers include a film (hereinafter also referred to as a "polarizer") obtained by uniaxially stretching a polymer such as PVA impregnated with iodine or an organic dichroic dye, and an optically anisotropic layer (hereinafter also referred to as a "polarizing film") formed by orienting a dichroic dye and a polymerizable liquid crystal compound.

[0012] The polarization performance of a linear polarizer can be measured using a spectrophotometer. For example, the transmittance (T1) in the transmission axis direction (direction perpendicular to the orientation) and the transmittance (T2) in the absorption axis direction (direction perpendicular to the orientation) can be measured using a spectrophotometer equipped with a prism polarizer and a double-beam method in the visible light wavelength range of 380 nm to 780 nm. The polarization performance in the visible light range can be calculated by calculating the single transmittance and degree of polarization at each wavelength using the following formulas (Formula 1) and (Formula 2). Further, by performing luminosity correction using a 2-degree visual field (illuminant C) according to JIS Z 8701, the luminosity-corrected single transmittance (Ty) and luminosity-corrected degree of polarization (Py) can be calculated. Furthermore, the color matching function for illuminant C can be used to calculate the L from the transmittance measured in the same way. * a * b * Chromaticity a in the (CIE) color system * and b * By calculating the above, the hue of the linear polarizer alone (single hue), the hue of the linear polarizers arranged in parallel (parallel hue), and the hue of the linear polarizers arranged orthogonally (orthogonal hue) can be obtained. * and b * The closer the value is to 0, the more neutral the hue is. Single transmittance (%) = (T1 + T2) / 2 (Equation 1) Polarization degree (%) = (T1-T2) / (T1+T2)×100 (Equation 2)

[0013] The luminous-corrected polarization degree Py of the linear polarizer is usually 80% or more, preferably 90% or more, more preferably 95% or more, even more preferably 98% or more, particularly preferably 99% or more, and may be 99.9% or more. Increasing the luminous-corrected polarization degree Py of the linear polarizer is advantageous for enhancing the antireflection function of the polarizing laminate. If the luminous-corrected polarization degree Py is less than 80%, the antireflection function may not be achieved when used as an antireflection film.

[0014] The higher the luminous-effect-corrected single transmittance Ty of the linear polarizer, the greater the clarity of the white display. However, as can be seen from the relationship between (Equation 1) and (Equation 2), if the single transmittance is too high, the degree of polarization decreases. Therefore, the single transmittance is preferably 30% to 60%, more preferably 35% to 55%, even more preferably 38% to 50%, still more preferably 40% to 45%, and most preferably 41% to 43%. If the luminous-effect-corrected single transmittance Ty is too high, the luminous-effect-corrected polarization degree Py will be too low, which may result in insufficient anti-reflection function when used as an anti-reflection film.

[0015] <Polarizer> A film obtained by uniaxially stretching a polymer such as a polyvinyl alcohol-based resin film (PVA) impregnated with iodine or an organic dichroic dye can usually be produced through the following steps: uniaxially stretching the polyvinyl alcohol-based resin film; dyeing the polyvinyl alcohol-based resin film with a dichroic dye such as iodine to adsorb the dichroic dye; treating the polyvinyl alcohol-based resin film with the adsorbed dichroic dye with a crosslinking agent such as a boric acid aqueous solution; and washing with water after the treatment with the crosslinking agent such as a boric acid aqueous solution.

[0016] 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.

[0017] The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after dyeing with a dichroic dye. When uniaxial stretching is performed after dyeing, it may be performed before or during the boric acid treatment. Of course, uniaxial stretching can also be performed in multiple stages as shown here. Examples of uniaxial stretching include uniaxial stretching in the film transport direction between rolls with different peripheral speeds, uniaxial stretching in the film transport direction using a heated roll, and stretching in the width direction using a tenter. The uniaxial stretching may be performed by dry stretching in the air, or by wet stretching in a swollen state using a solvent such as water. The stretching ratio is usually about 3 to 8 times. Alternatively, an aqueous solution containing polyvinyl alcohol may be applied to a thermoplastic resin film, followed by drying, and then stretched together with the thermoplastic resin film by the above-mentioned method.

[0018] Dyeing of a polyvinyl alcohol-based resin film with a dichroic dye can be carried out, for example, by immersing the polyvinyl alcohol-based resin film in an aqueous solution containing the dichroic dye. Specific examples of the dichroic dye include iodine and dichroic organic dyes. It is preferable that the polyvinyl alcohol-based resin film be immersed in water to swell it before dyeing.

[0019] When iodine is used as the dichroic dye, a method of dyeing a polyvinyl alcohol resin film by immersing it in an aqueous solution containing iodine and potassium iodide is usually employed. The iodine content in this aqueous solution is usually about 0.01 to 1 part by mass per 100 parts by mass of water, and the potassium iodide content is usually about 0.5 to 20 parts by mass per 100 parts by mass of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40°C. The immersion time in this aqueous solution (dyeing time) is usually about 20 to 1,800 seconds.

[0020] On the other hand, when a dichroic organic dye is used as the dichroic pigment, a method of dyeing a polyvinyl alcohol-based resin film by immersing it in an aqueous solution containing a water-soluble dichroic organic dye is usually employed. The content of the dichroic organic dye in this aqueous solution is usually about 0.0001 to 10 parts by mass, preferably 0.001 to 1 part by mass, per 100 parts by mass of water. This aqueous dye solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the aqueous dichroic organic dye solution used for dyeing is usually about 20 to 80°C. The immersion time in this aqueous solution (dyeing time) is usually about 10 to 1,800 seconds.

[0021] The boric acid treatment after dyeing with a dichroic dye can be carried out by immersing the dyed polyvinyl alcohol-based resin film in a boric acid-containing aqueous solution. The content of boric acid in the boric acid-containing aqueous solution is usually about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. When iodine is used as the dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide. The content of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. The immersion time in the boric acid-containing aqueous solution is usually about 60 to 1,200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50°C or higher, preferably 50 to 85°C, and more preferably 60 to 80°C.

[0022] The polyvinyl alcohol-based resin film after the boric acid treatment is usually washed with water. The washing can be carried out, for example, by immersing the boric acid-treated polyvinyl alcohol-based resin film in water. The temperature of the water used in the washing is usually about 5 to 40°C. The immersion time is usually about 1 to 120 seconds.

[0023] After washing with water, the polarizer is dried to obtain it. The drying can be performed using a hot air dryer or a far-infrared heater. The temperature for the drying is usually about 30 to 100°C, preferably 50 to 80°C. The drying time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. The drying reduces the moisture content in the polarizer to a practical level. The moisture content is usually about 5 to 20% by mass, preferably 8 to 15% by mass, based on the total mass of the polarizer. When the moisture content is 5% by mass or more, the polarizer has sufficient flexibility, and therefore damage or breakage after drying can be suppressed. Furthermore, when the moisture content is 20% by mass or less, the polarizer has sufficient thermal stability.

[0024] In this manner, a polarizer in which a dichroic dye is adsorbed and oriented in a polyvinyl alcohol-based resin film can be produced.

[0025] <Polarizing film> A polarizing film, i.e., an optically anisotropic layer made of a polymer of a polymerizable liquid crystal compound containing a dichroic dye, can be suitably used for flexible displays, for example, because the hue can be arbitrarily controlled, the thickness can be significantly reduced, and the film is non-shrinkable because it is not stretched or relaxed by heat.

[0026] A polarizing film is formed by applying a polarizing film-forming composition onto an alignment film, optionally formed on a substrate, and orienting the dichroic dye contained in the polarizing film-forming composition. The polarizing film has a thickness of 0.1 μm to 5 μm, more preferably 0.3 μm to 4 μm, and even more preferably 0.5 μm to 3 μm. If the film thickness is thinner than this range, the required light absorption may not be achieved. If the film thickness is thicker than this range, the alignment control force of the alignment film decreases, tending to cause alignment defects. The polarizing film-forming composition may further contain a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesion improver, etc.

[0027] In an optically anisotropic layer in which a dichroic dye and a polymerizable liquid crystal compound are aligned horizontally relative to the substrate surface, the ratio (dichroic ratio) of the absorbance A1(λ) in the alignment direction to the absorbance A2(λ) in the direction perpendicular to the alignment plane for light with a wavelength of λ nm is preferably 7 or more, more preferably 20 or more, and even more preferably 40 or more. The higher this value, the better the absorption selectivity of the polarizing plate. While it depends on the type of dichroic dye, in the case of a liquid crystal cured film cured in a nematic liquid crystal phase state, the ratio is approximately 5 to 10.

[0028] By mixing two or more dichroic dyes with different absorption wavelengths, it is possible to produce polarizing films with various hues and polarizing films that absorb light across the entire visible light range. Polarizing films with such absorption properties can be used in a variety of applications.

[0029] <Polarizing film; polymerizable liquid crystal compound> A polymerizable liquid crystal compound is a compound having a polymerizable group and liquid crystallinity (hereinafter also referred to as polymerizable liquid crystal). The polymerizable group refers to a group that participates in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that can participate in a polymerization reaction by an active radical or acid generated from a photopolymerization initiator, which will be described later. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. Among these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferred, with a methacryloyloxy group or an acryloyloxy group being more preferred. The liquid crystallinity may be thermotropic or lyotropic, but thermotropic liquid crystal is preferred when mixed with a dichroic dye, which will be described later. The polymerizable liquid crystal compound may be a monomer or a polymer obtained by polymerizing dimers or higher.

[0030] When the polymerizable liquid crystal compound is a thermotropic liquid crystal, it may be a thermotropic liquid crystal compound exhibiting a nematic liquid crystal phase or a thermotropic liquid crystal compound exhibiting a smectic liquid crystal phase. From the viewpoint of exhibiting high dichroism, the liquid crystal state exhibited by the polymerizable liquid crystal compound is preferably a smectic phase, and a higher-order smectic phase is more preferable from the viewpoint of improving performance. Among these, higher-order smectic liquid crystal compounds that form a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, or a smectic L phase are more preferred, and higher-order smectic liquid crystal compounds that form a smectic B phase, a smectic F phase, or a smectic I phase are even more preferred. When the liquid crystal phase formed by the polymerizable liquid crystal is one of these higher-order smectic phases, a polarizing film with higher polarization performance can be produced. Furthermore, such polarizing films with high polarization performance exhibit Bragg peaks derived from higher-order structures such as hexatic and crystalline phases in X-ray diffraction measurements. These Bragg peaks are derived from the periodic structure of molecular orientation, and films with periodic intervals of 3 to 6 Å can be obtained. The polarizing film of the present invention preferably contains a polymer of polymerizable liquid crystal oriented in a smectic phase, from the viewpoint of obtaining higher polarization properties.

[0031] The polymerizable liquid crystal compound may be used alone or in combination of two or more. The polymerizable liquid crystal composition containing other compounds described later may contain other polymerizable liquid crystal compounds other than the polymerizable liquid crystal compound as long as the effects of the present invention are not impaired. From the viewpoint of obtaining a polarizing film with a high degree of alignment order, the proportion of the polymerizable liquid crystal compound to the total mass of all polymerizable liquid crystal compounds contained in the polymerizable liquid crystal composition is preferably 51% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

[0032] The content of the polymerizable liquid crystal compound in the composition for forming a polarizing film of the present invention is preferably 40 to 99.9 mass %, more preferably 60 to 99 mass %, and even more preferably 70 to 99 mass %, based on the solid content of the polymerizable liquid crystal composition. When the content of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound tends to be high. In this specification, the solid content refers to the total amount of components of the polymerizable liquid crystal composition excluding the solvent.

[0033] <Polarizing film; dichroic dye> A dichroic dye is a dye that has different absorbance in the long axis direction of the molecule and in the short axis direction. Dichroic dyes preferably have the property of absorbing visible light, and more preferably have an absorption maximum wavelength (λMAX) in the range of 380 to 680 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes, with azo dyes being preferred. Examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, with bisazo dyes and trisazo dyes being preferred. Dichroic dyes may be used alone or in combination. However, to achieve absorption across the entire visible light range, it is preferable to combine two or more dichroic dyes, and more preferably three or more dichroic dyes.

[0034] Examples of azo dyes include compounds represented by formula (I) (hereinafter, also referred to as "compound (I)"). T1-A1(-N=N-A2)pN=N-A3-T2(I) [In formula (I), A1, A2, and A3 each independently represent an optionally substituted 1,4-phenylene group, an optionally substituted naphthalene-1,4-diyl group, an optionally substituted benzoic acid phenyl ester group, an optionally substituted 4,4'-stilbenylene group, or an optionally substituted divalent heterocyclic group; T1 and T2 each represent an electron-withdrawing group or an electron-releasing group, and are positioned at substantially 180° relative to the plane of the azo bond; p represents an integer of 0 to 4; when p is 2 or greater, each A2 may be the same or different; and the -N=N- bond may be replaced with a -C=C-, -COO-, -NHCO-, or -N=CH- bond as long as absorption in the visible range is exhibited.]

[0035] The content of the dichroic dye (the total amount when multiple types are included) is usually 1 to 60 parts by mass, preferably 1 to 40 parts by mass, and more preferably 1 to 20 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound, from the viewpoint of obtaining good light absorption properties. If the content of the dichroic dye is less than this range, light absorption will be insufficient and sufficient polarization performance will not be obtained, whereas if it is more than this range, the alignment of the liquid crystal molecules may be hindered.

[0036] (First protective layer 180 and second protective layer 190) The first protective layer 180 and the second protective layer 190 each have the function of protecting the surface of the linear polarizer 220. The protective layer may be a thermoplastic resin film. The thermoplastic resin film may be a film existing alone. In this case, the thermoplastic resin film is laminated on the linear polarizer via a pressure-sensitive adhesive layer as necessary. Alternatively, the protective layer may be a thermoplastic resin layer or a cured resin layer. The linear polarizer 220 and the thermoplastic resin film may be laminated directly to each other. Here, "directly laminated" includes an embodiment in which the thermoplastic resin film is laminated to the linear polarizer by the self-adhesive properties of the thermoplastic resin film and an embodiment in which the thermoplastic resin film is laminated via an adhesive layer or a pressure-sensitive adhesive layer. The thermoplastic resin film may be subjected to a surface treatment (e.g., corona treatment) to improve adhesion to the linear polarizer, or a thin layer such as a primer layer (also called an easy-adhesion layer) may be formed thereon.

[0037] Examples of thermoplastic resin films that can be used include resin films with excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and stretchability. Specific examples of such resins include cellulose-based resins such as triacetyl cellulose; polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone-based resins; polysulfone-based resins; polycarbonate-based resins; polyamide-based resins such as nylon and aromatic polyamide; polyimide-based resins; polyolefin-based resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; cyclic polyolefin-based resins having cyclo- and norbornene structures (also known as norbornene-based resins); (meth)acrylic resins such as polymethyl methacrylate; polyarylate-based resins; polystyrene-based resins; polyvinyl alcohol-based resins; and mixtures thereof. Thermoplastic resin films made of such materials are readily available commercially. In this specification, "(meth)acrylic" refers to either acrylic or methacrylic.

[0038] The thickness of the thermoplastic resin film is preferably 0.1 μm to 60 μm, more preferably 0.5 μm to 40 μm, and even more preferably 1 μm to 30 μm. In particular, the thickness of the second protective layer 190 is preferably 30 μm or less, and may be 20 μm or less.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0058] (Retardation layer laminate 300) The retardation layer laminate 300 has a first alignment film 20, a first liquid crystal retardation layer 30, a first bonding layer 40, a second liquid crystal retardation layer 50, and a second alignment film 60, in this order. The retardation layer laminate 300 may have either the first alignment film 20 or the second alignment film 60, or neither. The first alignment film 20 may be located on the first bonding layer 40 side of the first liquid crystal retardation layer 30. The second alignment film 60 may be located on the first bonding layer 40 side of the second liquid crystal retardation layer 50.

[0059] [First alignment film 20 and second alignment film 60] In this specification, the alignment film has an alignment regulating force that aligns the polymerizable liquid crystal compound in a desired direction.

[0060] Alignment films facilitate the alignment of polymerizable liquid crystal compounds. Liquid crystal alignment states, such as horizontal alignment, vertical alignment, hybrid alignment, and tilted alignment, vary depending on the properties of the alignment film and the polymerizable liquid crystal compound, and these combinations can be selected arbitrarily. For example, if the alignment film is made of a material that exerts a horizontal alignment as an alignment control force, the polymerizable liquid crystal compound can form horizontal or hybrid alignment. If the alignment film is made of a material that exerts a vertical alignment, the polymerizable liquid crystal compound can form vertical or tilted alignment. The terms horizontal, vertical, and so on refer to the direction of the optical axis of the aligned polymerizable liquid crystal compound relative to the plane of the optically anisotropic layer. For example, vertical alignment means that the optical axis of the aligned polymerizable liquid crystal compound is perpendicular to the plane of the optically anisotropic layer. Here, vertical means 90°±20° relative to the plane of the optically anisotropic layer.

[0061] When the alignment film is made of an alignment polymer, the alignment restraining force can be adjusted arbitrarily by the surface condition or rubbing conditions, and when it is made of a photoalignment polymer, the alignment restraining force can be adjusted arbitrarily by the polarized light irradiation conditions, etc. Furthermore, the liquid crystal alignment can also be controlled by selecting the physical properties of the polymerizable liquid crystal compound, such as the surface tension or liquid crystallinity.

[0062] The alignment film formed between the substrate and the optically anisotropic layer is preferably insoluble in the solvent used to form the optically anisotropic layer on the alignment film, and is heat-resistant to the heat treatment for removing the solvent and orienting the liquid crystal. Examples of the alignment film include alignment films made of orientable polymers, photo-alignment films, groove-alignment films, and stretched films stretched in the alignment direction. When applied to a long roll film, photo-alignment films are preferred because the alignment direction can be easily controlled.

[0063] The thickness of the alignment film is usually in the range of 10 nm to 5000 nm, preferably in the range of 10 nm to 1000 nm, and more preferably in the range of 30 to 300 nm.

[0064] Examples of alignment polymers used in rubbed alignment films include polyamides and gelatins having an amide bond in the molecule, polyimides having an imide bond in the molecule, and their hydrolyzed products such as polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylic acid esters. Among these, polyvinyl alcohol is preferred. These alignment polymers may be used alone or in combination of two or more.

[0065] Rubbing methods include a method in which an oriented polymer film formed on the surface of a substrate by applying an oriented polymer composition to the substrate and annealing the composition is brought into contact with a rotating rubbing roll wrapped with a rubbing cloth.

[0066] The photo-alignment film is made of a polymer, oligomer, or monomer having a photoreactive group. The photo-alignment film can obtain an alignment control force by irradiating it with polarized light. The photo-alignment film is preferable because the direction of the alignment control force can be freely controlled by selecting the polarization direction of the irradiated polarized light.

[0067] A photoreactive group is a group that exhibits liquid crystal alignment ability upon irradiation with light. Specifically, it induces molecular alignment or a photoreaction that is the origin of liquid crystal alignment ability, such as an isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photodecomposition reaction, upon irradiation with light. Among such photoreactive groups, those that undergo a dimerization reaction or a photocrosslinking reaction are preferred because of their excellent alignment ability. As photoreactive groups capable of causing such reactions, those having an unsaturated bond, particularly a double bond, are preferred, and groups having at least one bond selected from the group consisting of a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond), and a carbon-oxygen double bond (C=O bond) are more preferred.

[0068] Examples of photoreactive groups having a C=C bond include vinyl groups, polyene groups, stilbene groups, stilbazole groups, stilbazolium groups, chalcone groups, and cinnamoyl groups. Chalcone and cinnamoyl groups are preferred because of their ease of reactivity control and the ability to exert alignment control forces during photoalignment. Examples of photoreactive groups having a C=N bond include groups having structures such as aromatic Schiff bases and aromatic hydrazones. Examples of photoreactive groups having an N=N bond include azobenzene groups, azonaphthalene groups, aromatic heterocyclic azo groups, bisazo groups, and formazan groups, as well as groups with an azoxybenzene basic structure. Examples of photoreactive groups having a C=O bond include benzophenone groups, coumarin groups, anthraquinone groups, and maleimide groups. These groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and halogenated alkyl groups.

[0069] Polarized light can be irradiated either directly from the film surface or from the substrate side and then transmitted through the film. It is particularly preferred that the polarized light be substantially parallel. The wavelength of the polarized light irradiated should be within a wavelength range in which the photoreactive group in the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) with a wavelength of 250 to 400 nm is particularly preferred. Examples of light sources used for polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and ultraviolet lasers such as KrF and ArF. High-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps are more preferred. These lamps are preferred because of their high emission intensity of ultraviolet light with a wavelength of 313 nm. Polarized light can be irradiated by passing light from the light source through an appropriate polarizer. Examples of such polarizers include polarizing filters, polarizing prisms such as Glan-Thompson and Glan-Taylor, and wire-grid polarizers.

[0070] The composition for forming an alignment film may contain a leveling agent as needed. In particular, when the outer pressure-sensitive adhesive layer 500 in the polarizing laminate 400 contains a silane compound, the composition for forming the alignment film to be bonded to the outer pressure-sensitive adhesive layer 500 preferably contains a leveling agent. As the leveling agent, a silicone-based leveling agent and / or a fluorine-based leveling agent, which will be described in the section on the liquid crystal retardation layer below, can be used, and it is preferable to use a silicone-based leveling agent. The content of the leveling agent in the solid content of the composition for forming an alignment film is usually preferably 0.001 to 3 mass%, more preferably 0.01 to 3 mass%, and even more preferably 0.1 to 3 mass%.

[0071] (First liquid crystal retardation layer 30 and second liquid crystal retardation layer 50)

[0072] The liquid crystal retardation layer is a cured layer of an aligned polymerizable liquid crystal compound, and exhibits retardation.

[0073] The liquid crystal retardation layer is not limited as long as it is a layer that exhibits retardation in any direction, and may be a retardation layer that generates an in-plane retardation such as a positive A plate or a negative A plate, or may be a retardation layer that generates a retardation in the thickness direction such as a positive C plate or a negative C plate. The positive A plate and the negative A plate may each be a λ / 4 plate or a λ / 2 plate. The liquid crystal retardation layer may be tilted or may form a cholesteric alignment state.

[0074] The first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 may each independently be a single liquid crystal retardation layer or a laminate of a plurality of liquid crystal retardation layers.

[0075] The liquid crystal retardation layer may have either a normal wavelength dispersion or a reverse wavelength dispersion.

[0076] It is preferable that the laminate of the first liquid crystal retardation layer 30, the first attaching layer 40, and the second liquid crystal retardation layer 50 satisfy the relationships of the following formulas (1) and (2). 100≦Re(550)≦180 (1) Re(450) / Re(550)≦1.00 (2) [In formula (1) and formula (2), Re(450) represents the in-plane retardation value (nm) for light with a wavelength of 450 nm, Re(550) represents the in-plane retardation value (nm) for light with a wavelength of 550 nm. The in-plane retardation value of the laminate (retardation film) is a value measured by laminating a polarizing plate on the laminate via an adhesive, and measuring the polarizing plate / adhesive / first liquid-phase retardation layer / first bonding layer / second liquid-crystal retardation layer state using an in-plane manipulation measuring device such as KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. The polarizing plate and adhesive may be any polarizing plate and adhesive described below.

[0077] The liquid crystal retardation layer is usually formed by applying a liquid crystal retardation layer-forming composition containing a polymerizable liquid crystal compound onto an alignment film formed on a substrate, and polymerizing and curing the polymerizable liquid crystal compound in an aligned state.

[0078] The thickness of the liquid crystal retardation layer is usually 10 μm or less, preferably 5 μm or less, and more preferably 0.3 μm or more and 3 μm or less.

[0079] In order to achieve a high level of anti-reflection function, the liquid crystal retardation layer preferably has a λ / 4 plate function (i.e., a π / 2 retardation function) over the entire visible light range. Specifically, a reverse wavelength dispersion λ / 4 layer is preferred, or a combination of two or more retardation films with different orientations is preferred. For example, a combination of a retardation film having a λ / 2 plate function (i.e., a π retardation function) and a retardation film having a λ / 4 plate function (i.e., a π / 2 retardation function) may be used.

[0080] Furthermore, from the viewpoint of ensuring the anti-reflection function in oblique directions, it is preferable to include a layer having anisotropy in the thickness direction (positive C plate). Moreover, each liquid crystal retardation layer may have a tilt alignment or may form a cholesteric alignment state.

[0081] (Combination of First Liquid Crystal Retardation Layer and Second Liquid Crystal Retardation Layer) The first and second liquid crystal retardation layers may be the same liquid crystal retardation layer, or may be a combination of different types.

[0082] For example, one of the first and second liquid crystal retardation layers may be a reverse wavelength dispersion λ / 4 plate, and the other of the first and second liquid crystal retardation layers may be a positive C plate.

[0083] Alternatively, one of the first liquid crystal retardation layer and the second liquid crystal retardation layer may be a positive wavelength dispersion λ / 2 plate, and the other of the first liquid crystal retardation layer and the second liquid crystal retardation layer may be a positive wavelength dispersion λ / 4 plate.

[0084] Hereinafter, as an example of the liquid crystal retardation layer, a stack of a reverse wavelength dispersion λ / 4 plate, a positive wavelength dispersion λ / 4 plate and a positive wavelength dispersion λ / 2 plate, and a positive C plate will be described.

[0085] (Reverse wavelength dispersion λ / 4 plate (R)) The reverse wavelength dispersion λ / 4 plate preferably satisfies the optical properties represented by the following formulas (R1) and (R2), where Re(λ) is the in-plane retardation for light with a wavelength of λ nm over the entire visible light range, and more preferably satisfies the optical properties represented by the following formulas (R1), (R2), and (R3):

[0086] 100nm <Re(550)<160nm …(R1) (In the formula, Re(550) represents the in-plane phase difference value (in-plane retardation) for light with a wavelength of 550 nm.) Re(450) / Re(550)≦1.0 …(R2) 1.00≦Re(650) / Re(550) …(R3) (In the formula, Re(450) represents the in-plane retardation value (unit: nm) for light with a wavelength of 450 nm, Re(550) represents the in-plane retardation value (unit: nm) for light with a wavelength of 550 nm, and Re(650) represents the in-plane retardation value (unit: nm) for light with a wavelength of 650 nm.) When the "Re(450) / Re(550)" of the liquid crystal retardation film exceeds 1.0, the light leakage on the short wavelength side of an elliptical polarizing plate including the liquid crystal retardation film increases, and is preferably 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.

[0087] The value of "Re(450) / Re(550)" can be adjusted arbitrarily by adjusting the mixing ratio of the polymerizable liquid crystal compound, the lamination angle of the plurality of optically anisotropic layers, and the retardation value.

[0088] The in-plane retardation value of the retardation film can be adjusted by the thickness of the retardation film. Since the in-plane retardation value is determined by the following formula (4), a desired in-plane retardation value (Re(λ)) can be obtained by adjusting Δn(λ) and the film thickness d. The thickness of the retardation film is preferably 0.5 μm to 5 μm, more preferably 1 μm to 3 μm. The thickness of the retardation film can be measured using an interference film thickness meter, a laser microscope, or a stylus film thickness meter. Δn(λ) depends on the molecular structure of the polymerizable liquid crystal compound, which will be described later.

[0089] Re(λ)=d×Δn(λ) …(4) (In the formula, Re(λ) represents the in-plane retardation value (nm) at a wavelength of λ nm, d represents the film thickness, and Δn(λ) represents the birefringence at a wavelength of λ nm.)

[0090] The liquid crystal retardation film is usually formed by applying a liquid crystal retardation layer-forming composition onto an alignment film formed on a substrate, and polymerizing the polymerizable liquid crystal compound contained in the liquid crystal retardation layer composition in an aligned state. The retardation film-forming composition may further contain a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesion improver, etc.

[0091] <Polymerizable liquid crystal compound for forming a reverse wavelength dispersion λ / 4 plate> A polymerizable liquid crystal compound refers to a liquid crystal compound having a polymerizable group, particularly a photopolymerizable group. Conventional polymerizable liquid crystal compounds can be used as the polymerizable liquid crystal compound for forming a reverse wavelength dispersion λ / 4 plate. The photopolymerizable group refers to a group that can participate in a polymerization reaction by reactive species, such as active radicals or acids, generated from a photopolymerization initiator. Examples of photopolymerizable groups include vinyl groups, vinyloxy groups, 1-chlorovinyl groups, isopropenyl groups, 4-vinylphenyl groups, acryloyloxy groups, methacryloyloxy groups, oxiranyl groups, and oxetanyl groups. Among these, acryloyloxy groups, methacryloyloxy groups, vinyloxy groups, oxiranyl groups, and oxetanyl groups are preferred, with acryloyloxy groups being more preferred. The liquid crystal property may be either thermotropic or lyotropic, but thermotropic liquid crystals are preferred due to their ability to precisely control the film thickness. Furthermore, the phase order structure of the thermotropic liquid crystal may be either nematic or smectic. The polymerizable liquid crystal compounds may be rod-shaped or discotic. They may be used alone or in combination of two or more.

[0092] As the polymerizable liquid crystal compound, from the viewpoint of exhibiting reverse wavelength dispersion, a liquid crystal having a T-shaped or H-shaped mesogen structure which further has birefringence in the direction perpendicular to the molecular long axis direction is preferred, and from the viewpoint of obtaining stronger dispersion, a T-shaped liquid crystal is more preferred. Specific examples of the structure of the T-shaped liquid crystal include those represented by the following formula (I):

[0093] [ka] Examples of the compound include compounds represented by the following formula:

[0094] In formula (I), Ar represents a divalent aromatic group which may have a substituent. The divalent aromatic group preferably contains at least one of a nitrogen atom, an oxygen atom, and a sulfur atom. When the divalent group Ar contains two or more aromatic groups, the two or more aromatic groups may be bonded to each other via a divalent bonding group such as a single bond, -CO-O-, or -O-.

[0095] G 1 and G 2 each independently represents a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein a hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group, and a carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom.

[0096] L 1 , L 2 、 B 1 and B 2 are each independently a single bond or a divalent linking group.

[0097] k and l each independently represent an integer of 0 to 3, and satisfy the relationship 1≦k+l. When 2≦k+l, B 1 and B 2 , G 1 and G 2 may be the same as or different from each other.

[0098] E 1 and E 2 each independently represents an alkanediyl group having 1 to 17 carbon atoms, wherein a hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and wherein a -CH2- contained in the alkanediyl group may be substituted with -O-, -S-, or -COO-, and when there are a plurality of -O-, -S-, or -COO-, they are not adjacent to each other. 1 and P 2 each independently represents a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.

[0099] G 1 and G 2are each independently preferably a 1,4-phenylenediyl group optionally substituted with at least one substituent selected from the group consisting of halogen atoms and alkyl groups having 1 to 4 carbon atoms, or a 1,4-cyclohexanediyl group optionally substituted with at least one substituent selected from the group consisting of halogen atoms and alkyl groups having 1 to 4 carbon atoms, more preferably a 1,4-phenylenediyl group substituted with a methyl group, an unsubstituted 1,4-phenylenediyl group, or an unsubstituted 1,4-trans-cyclohexanediyl group, and particularly preferably an unsubstituted 1,4-phenylenediyl group or an unsubstituted 1,4-trans-cyclohexanediyl group.

[0100] Also, there are multiple G 1 and G 2 At least one of L is preferably a divalent alicyclic hydrocarbon group. 1 or L 2 G binds to 1 and G 2 It is more preferable that at least one of the groups is a divalent alicyclic hydrocarbon group.

[0101] L 1 and L 2 are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a1 OR a2 -, -R a3 COOR a4 -, -R a5 OCOR a6 -, R a7 OC=OOR a8 -, -N=N-, -CR c =CR d -, or C≡C-, where R a1 ~R a8 each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms; R c and R d represents an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. 1 and L 2 are each independently preferably a single bond, -OR a2-1-, -CH2-, -CH2CH2-, -COOR a4-1 - or OCOR a6-1 -, where R a2-1 , R a4-1 , R a6-1 Each independently represents a single bond, -CH2-, or -CH2CH2-. 1 and L 2 are each independently more preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, or OCO-.

[0102] B 1 and B 2 are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a9 OR a10 -, -R a11 COOR a12 -, -R a13 OCOR a14 - or R a15 OC=OOR a16 -, where R a9 ~R a16 each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms. 1 and B 2 are each independently preferably a single bond, -OR a10-1 -, -CH2-, -CH2CH2-, -COOR a12-1 - or OCOR a14-1 -, where R a10-1 , R a12-1 , R a14-1 Each independently represents a single bond, -CH2-, or -CH2CH2-. B 1 and B 2 are each independently more preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, -OCO-, or OCOCH2CH2-.

[0103] From the viewpoint of exhibiting reverse wavelength dispersion, k and l are preferably in the range of 2≦k+l≦6, preferably k+l=4, and more preferably k=2 and l=2. When k=2 and l=2, a symmetric structure is obtained, which is preferable.

[0104] E 1 and E 2 are each independently preferably an alkanediyl group having 1 to 17 carbon atoms, more preferably an alkanediyl group having 4 to 12 carbon atoms.

[0105] P 1 or P 2 Examples of the polymerizable group represented by the formula (I) include an epoxy group, a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. Among these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferred, and an acryloyloxy group is more preferred.

[0106] Ar preferably has at least one selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, and an electron-withdrawing group. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring, with a benzene ring and a naphthalene ring being preferred. Examples of the aromatic heterocyclic ring include a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazole ring, a triazine ring, a pyrroline ring, an imidazole ring, a pyrazole ring, a thiazole ring, a benzothiazole ring, a thienothiazole ring, an oxazole ring, a benzoxazole ring, and a phenanthroline ring. Among these, a thiazole ring, a benzothiazole ring, or a benzofuran ring is preferred, and a benzothiazole group is even more preferred. Furthermore, when Ar contains a nitrogen atom, it is preferred that the nitrogen atom has π electrons.

[0107] In formula (I), the total number of π electrons contained in the divalent aromatic group represented by Ar is N πis preferably 8 or more, more preferably 10 or more, even more preferably 14 or more, and particularly preferably 16 or more. It is also preferably 30 or less, more preferably 26 or less, and even more preferably 24 or less.

[0108] Suitable examples of the aromatic group represented by Ar include the following groups:

[0109] [ka]

[0110] In formulas (Ar-1) to (Ar-23), * represents a linking portion, and Z 0 , Z 1 and Z 2 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, an alkylsulfonyl group having 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, an N-alkylamino group having 1 to 12 carbon atoms, an N,N-dialkylamino group having 2 to 12 carbon atoms, an N-alkylsulfamoyl group having 1 to 12 carbon atoms, or an N,N-dialkylsulfamoyl group having 2 to 12 carbon atoms.

[0111] Q 1 , and Q 2 are each independently -CR 2’ R 3’ -, -S-, -NH-, -NR 2’ represents -, -CO- or O-; R 2’ and R 3’ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0112] J 1 , and J 2 each independently represents a carbon atom or a nitrogen atom.

[0113] Y 1 , and Y 2each independently represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group.

[0114] W 1 and W 2 each independently represents a hydrogen atom, a cyano group, a methyl group or a halogen atom; and m represents an integer of 0 to 6.

[0115] Y 1 , and Y 2 Examples of the aromatic hydrocarbon group in the formula (I) include aromatic hydrocarbon groups having 6 to 20 carbon atoms, such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, and a biphenyl group, with a phenyl group and a naphthyl group being preferred, and a phenyl group being more preferred. Examples of the aromatic heterocyclic group include aromatic heterocyclic groups having 4 to 20 carbon atoms and containing at least one heteroatom, such as a nitrogen atom, an oxygen atom, or a sulfur atom, such as a furyl group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group, and a benzothiazolyl group being preferred.

[0116] Y 1 , and Y 2 may each independently be an optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group. The polycyclic aromatic hydrocarbon group refers to a fused polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. The polycyclic aromatic heterocyclic group refers to a fused polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

[0117] Z 0 , Z 1 and Z 2 are each independently preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms, and Z 0 is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, and Z 1 and Z 2 is more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.

[0118] Q1 , and Q 2 -NH-, -S-, -NR 2’ -, -O- are preferred, and R 2’ is preferably a hydrogen atom, and among these, -S-, -O-, and -NH- are particularly preferred.

[0119] Among the formulae (Ar-1) to (Ar-23), the formulae (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability.

[0120] In formulas (Ar-16) to (Ar-23), Y 1 is the nitrogen atom to which it is bonded and Z 0 and Y may form an aromatic heterocyclic group together. Examples of the aromatic heterocyclic group include those mentioned above as aromatic heterocycles that Ar may have, such as a pyrrole ring, an imidazole ring, a pyrroline ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, an indole ring, a quinoline ring, an isoquinoline ring, a purine ring, and a pyrrolidine ring. This aromatic heterocyclic group may have a substituent. In addition, Y 1 is the nitrogen atom to which it is bonded and Z 0 and may be the above-mentioned optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group, such as a benzofuran ring, a benzothiazole ring, or a benzoxazole ring.

[0121] Among polymerizable liquid crystal compounds, compounds with a maximum absorption wavelength of 300 to 400 nm are preferred. When a polymerizable liquid crystal composition contains a photopolymerization initiator, the polymerization reaction and gelation of the polymerizable liquid crystal compound may progress during long-term storage. However, if the polymerizable liquid crystal compound has a maximum absorption wavelength of 300 to 400 nm, even if the composition is exposed to ultraviolet light during storage, the generation of reactive species from the photopolymerization initiator and the progression of the polymerization reaction and gelation of the polymerizable liquid crystal compound due to the reactive species can be effectively suppressed. This is advantageous in terms of long-term stability of the polymerizable liquid crystal composition and can improve the alignment and film thickness uniformity of the resulting cured liquid crystal film. The maximum absorption wavelength of the polymerizable liquid crystal compound can be measured using a UV-visible spectrophotometer in a solvent. The solvent can be a solvent capable of dissolving the polymerizable liquid crystal compound, such as chloroform.

[0122] The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass, relative to 100 parts by mass of the solid content of the polymerizable liquid crystal composition. A content of the polymerizable liquid crystal compound within the above range is advantageous from the viewpoint of the alignment of the resulting cured liquid crystal film. In this specification, the solid content of the polymerizable liquid crystal composition refers to all components of the polymerizable liquid crystal composition excluding volatile components such as organic solvents.

[0123] [Laminate containing a positive wavelength dispersive λ / 2 plate and a positive wavelength dispersive λ / 4 plate] As a method for achieving antireflection performance, a laminate combining a positive wavelength dispersion λ / 2 plate and a positive wavelength dispersion λ / 4 plate is known. For example, one example of a laminate can be obtained by combining a layer having the optical properties represented by formulas (Q1), (Q3), and (Q4) with a layer having the optical properties represented by formulas (Q2), (Q3), and (Q4) in a specific slow axis relationship.

[0124] 100nm <Re(550)<160nm (Q1) 200nm <Re(550)<320nm (Q2) Re(450) / Re(550)≧1.00 (Q3) 1.00≧Re(650) / Re(550) (Q4)

[0125] Methods for combining the above configurations include well-known methods such as those described in JP 2015-163935 A and WO 2013 / 137464 A. From the viewpoint of viewing angle compensation, it is preferable to use a λ / 2 layer containing a polymer of a discotic polymerizable liquid crystal compound and a λ / 4 layer containing a polymer of a rod-shaped polymerizable liquid crystal compound.

[0126] Examples of the discotic polymerizable liquid crystal compound include a compound containing a group represented by formula (W) (hereinafter, sometimes referred to as polymerizable liquid crystal compound (C)). [ka] [In formula (W), R 40 represents the following formulas (W-1) to (W-5).

[0127] [ka]

[0128] X 40 and Z 40 represents an alkanediyl group having 1 to 12 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and a hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. Furthermore, -CH2- constituting the alkanediyl group may be replaced with -O- or -CO-. Furthermore, m2 is an integer of 1 to 20.

[0129] Examples of the rod-shaped polymerizable liquid crystal compound include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V) or formula (VI). P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III) P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV) P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V) P11-B11-E11-B12-A11-B13-A12-F11 (VI) A11 represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. A hydrogen atom contained in the divalent alicyclic hydrocarbon group or divalent aromatic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group, and a hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom.

[0130] B11 is -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR 16 -, -NR 16 R represents -CO-, -CO-, -CS- or a single bond. 16 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0131] B12 and B13 each independently represent -C≡C-, -CH=CH-, -CH2-CH2-, -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)-, -OC(=O)-O-, -CH=N-, -N=CH-, -N=N-, or -C(=O)-NR 16 -, -NR 16 represents -C(=O)-, -OCH2-, -OCF2-, -CHO-, -CF2O-, -CH=CH-C(=O)-O-, -OC(=O)-CH=CH- or a single bond.

[0132] E11 represents an alkanediyl group having 1 to 12 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and a hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. In addition, -CH2- constituting the alkanediyl group may be substituted with -O- or -CO-.

[0133] The number of carbon atoms in the aromatic hydrocarbon group and alicyclic hydrocarbon group of A11 is preferably in the range of 3 to 18, more preferably in the range of 5 to 12, and particularly preferably 5 or 6. A11 is preferably a cyclohexane-1,4-diyl group or a 1,4-phenylene group.

[0134] E11 is preferably a linear alkanediyl group having 1 to 12 carbon atoms. -CH2- constituting the alkanediyl group may be replaced with -O-.

[0135] Specific examples include linear alkanediyl groups having 1 to 12 carbon atoms, such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; -CH-CH-O-CH-CH-, -CH-CH-O-CH-CH-O-CH-CH-, and -CH-CH-O-CH-CH-O-CH-CH-O-CH-CH-.

[0136] As B11, -O-, -S-, -CO-O-, and -O-CO- are preferred, and among these, -CO-O- is more preferred.

[0137] B12 and B13 are each independently preferably -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)- or -OC(=O)-O-, and among these, -O- or -OC(=O)-O- is more preferred.

[0138] The polymerizable group represented by P11 is preferably a radically polymerizable group or a cationically polymerizable group in terms of high polymerization reactivity, particularly high photopolymerization reactivity. In addition, the polymerizable group is preferably a group represented by the following formulas (P-11) to (P-15), because they are easy to handle and the liquid crystal compound itself is easy to produce.

[0139] [ka] [In formulas (P-11) to (P-15), R 17 ~R 21 each independently represents an alkyl group having 1 to 6 carbon atoms or a hydrogen atom.

[0140] Specific examples of the groups represented by formulae (P-11) to (P-15) include groups represented by the following formulae (P-16) to (P-20).

[0141] [ka]

[0142] P11 is preferably a group represented by formula (P-14) to formula (P-20), and more preferably a vinyl group, a p-stilbene group, an epoxy group or an oxetanyl group.

[0143] The group represented by P11-B11- is more preferably an acryloyloxy group or a methacryloyloxy group.

[0144] (In the formula, A12 to A14 each independently have the same meaning as A11, B14 to B16 each independently have the same meaning as B12, B17 has the same meaning as B11, and E12 has the same meaning as E11. F11 represents a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group (—SOH), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and —CH 2 - may be replaced with -O-.

[0145] [Other configurations] The first and second liquid crystal retardation layers may be configured by combining the above-mentioned positive wavelength dispersion λ / 2 layer and positive wavelength dispersion λ / 4 layer, or may be a laminate in which at least one liquid crystal retardation layer has a tilt orientation or a cholesteric orientation, for example, well-known configurations such as those described in WO2021 / 060378, WO2021 / 132616, and WO2021 / 132624.

[0146] [Composition for forming liquid crystal retardation layer] The content of the polymerizable liquid crystal compound in the composition for forming a liquid crystal retardation layer is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass, relative to 100 parts by mass of the solid content of the composition for forming a liquid crystal retardation layer. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous in terms of the alignment of the obtained liquid crystal retardation layer. In this specification, the solid content of the composition for forming a liquid crystal retardation layer means all components excluding volatile components such as organic solvents from the composition for forming a liquid crystal retardation layer.

[0147] <Positive C Plate> There are no particular limitations on the positive C plate as long as it has anisotropy in the thickness direction, but if it does not have tilt alignment or cholesteric alignment, it has optical properties expressed by formula (PC3). nx≒ny <nz (PC3)

[0148] The in-plane retardation value Re(550) of the positive C plate at a wavelength of 550 nm is usually in the range of 0 to 10 nm, preferably 0 to 5 nm. Furthermore, the thickness direction retardation value Rth(550) at a wavelength of 550 nm is usually in the range of −170 nm to −10 nm, preferably −150 nm to −20 nm, and more preferably −100 nm to −40 nm. If the thickness direction retardation value falls within this range, the anti-reflection properties from oblique directions can be further improved.

[0149] The thickness of the positive C plate is usually 10 μm or less, preferably 5 μm or less, and more preferably 0.3 μm or more and 3 μm or less.

[0150] The positive C plate is preferably a coating layer formed by polymerizing one or more polymerizable liquid crystal compounds, more preferably rod-shaped polymerizable liquid crystal compounds.

[0151] Examples of the rod-shaped polymerizable liquid crystal include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V) or formula (VI). P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III) P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV) P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V) P11-B11-E11-B12-A11-B13-A12-F11 (VI) (In the formula, A12 to A14 each independently have the same meaning as A11, B14 to B16 each independently have the same meaning as B12, B17 has the same meaning as B11, and E12 has the same meaning as E11. F11 represents a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group (—SOH), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and —CH— constituting the alkyl group and alkoxy group may be replaced with —O—.)

[0152] The content of the polymerizable liquid crystal compound in the composition for forming a liquid crystal retardation layer is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass, relative to 100 parts by mass of the solid content of the composition for forming a liquid crystal retardation layer. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous in terms of the alignment of the obtained liquid crystal retardation layer. In this specification, the solid content of the composition for forming a liquid crystal retardation layer means all components of the polymerizable liquid crystal composition excluding volatile components such as organic solvents.

[0153] <Composition for forming liquid crystal retardation layer> The liquid crystal retardation layer is usually formed by applying a liquid crystal retardation layer-forming composition containing a polymerizable liquid crystal compound onto an alignment film formed on a substrate as needed, and polymerizing and curing the polymerizable liquid crystal compound in an aligned state. The composition for forming a liquid crystal retardation layer may further contain reactive additives such as a solvent, a leveling agent, a polymerization initiator, a photosensitizer, a polymerization inhibitor, a crosslinking agent, and an adhesive agent in addition to the above-mentioned polymerizable liquid crystal compound. It is preferable to contain a solvent and / or a leveling agent from the viewpoint of processability, and it is suitable to add a silicone-based leveling agent from the viewpoint of adding Si.

[0154] <Solvent> The liquid crystal retardation layer forming composition may contain a solvent. Generally, a polymerizable liquid crystal compound has a high viscosity, so that dissolving the liquid crystal retardation layer forming composition in a solvent makes it easy to apply, and as a result, it often becomes easy to form a liquid crystal retardation layer. The solvent is preferably one that can completely dissolve the polymerizable liquid crystal compound, and is also preferably a solvent that is inactive to the polymerization reaction of the polymerizable liquid crystal compound.

[0155] Examples of solvents include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene, and nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; and amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone. These solvents may be used alone or in combination.

[0156] The content of the solvent is preferably 50 to 98% by mass with respect to the total amount of the composition for forming a liquid crystal retardation layer. In other words, the content of the solid content in the composition for forming a liquid crystal retardation layer is preferably 2 to 50% by mass, more preferably 5 to 30% by mass. When the content of the solid content is 50% by mass or less, the viscosity of the composition for forming a liquid crystal retardation layer is low, and the thickness of the liquid crystal retardation layer becomes approximately uniform, which tends to reduce the occurrence of unevenness in the liquid crystal retardation layer. In addition, the content of the solid content can be determined in consideration of the thickness of the optically anisotropic layer to be produced.

[0157] <Leveling agent> The liquid crystal retardation layer forming composition may contain a leveling agent. The leveling agent is an additive that adjusts the fluidity of the composition and has the function of making the film obtained by applying the composition flatter, and examples thereof include silicone-based leveling agents, acrylic-based leveling agents, and fluorine-based leveling agents. Among these, silicone-based leveling agents and fluorine-based leveling agents are preferred, as they are excellent in reducing the tension of the film surface obtained by applying the composition.

[0158] Examples of silicone-based leveling agents include leveling agents having a polyorganosiloxane skeleton.

[0159] Examples of groups bonded to silicon atoms (silicon atoms forming siloxane bonds) in polyorganosiloxane include hydrocarbon groups, etc. The silicone leveling agent may be one in which two hydrocarbon groups are bonded to a silicon atom. There are no limitations on the group bonded to the silicon atom, but among them, alkyl groups having 1 to 10 carbon atoms and aryl groups are preferred, more preferably methyl groups and phenyl groups, and even more preferably methyl groups. The group bonded to the silicon atom may be of one type or of two or more types. The number of repetitions of the siloxane unit (degree of polymerization) is not particularly limited, but is preferably 2 to 10,000, more preferably 3 to 5,000, and even more preferably 5 to 1,000.

[0160] As the silicone leveling agent, commercially available products can be used, for example, SH710 (manufactured by Toray Dow Corning Co., Ltd.), BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315N, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330, BYK -331, BYK-333, BYK-337, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYK-370, BYK-377, BYK-378, BYK-3455, BYK-UV3510 (all manufactured by BYK Japan Co., Ltd.), KF-945, KF-6015, KF-60 20 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TEGORad2300, TEGORad2200N, TEGORad2011 (manufactured by Degussa), and those having a radical polymerizable group such as a (meth)acryloyl group added to the polyether chain include BYK-UV3500, BYK-UV3505, BYK-3510, BYK-UV3530, BYK-UV3570, BYK-UV3575, BYK-UV3576 (all manufactured by BYK Japan KK), KP-422, KP-416, KP-418, KP-410, KP-411, KP-412, KP-413, KP-423, KP-414, KP-415, KP-420, and KP-983 (all manufactured by Shin-Etsu Chemical Co., Ltd.).

[0161] The content of the silicone-based leveling agent in the composition for forming a liquid crystal retardation layer is preferably 0.001 to 2 parts by mass, more preferably 0.01 to 1.5 parts by mass, and even more preferably 0.1 to 1.5 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0162] The fluorine-based leveling agent is not particularly limited, but examples thereof include leveling agents having a fluoroaliphatic hydrocarbon skeleton. The fluoroaliphatic hydrocarbon skeleton is not particularly limited, but examples thereof include fluoroalkanes having 1 to 10 carbon atoms, such as fluoromethane, fluoroethane, fluoropropane, fluoroisopropane, fluorobutane, fluoroisobutane, fluoro-t-butane, fluoropentane, and fluorohexane. The fluoroaliphatic hydrocarbon skeleton may have at least some of the hydrogen atoms substituted with fluorine atoms, but may also be a perfluoroaliphatic hydrocarbon skeleton in which all of the hydrogen atoms are substituted with fluorine atoms.

[0163] The fluoroaliphatic hydrocarbon skeleton may also form a polyfluoroalkylene ether skeleton, which is a repeating unit via an ether bond. The fluoroaliphatic hydrocarbon group as a repeating unit is not particularly limited, but examples thereof include fluoro C1-4 alkylene groups such as fluoromethylene, fluoroethylene, fluoropropylene, and fluoroisopropylene. The fluoroaliphatic hydrocarbon group may be of one type only, or of two or more types. The number of repetitions (degree of polymerization) of the fluoroalkylene ether unit is not particularly limited, but is preferably 10 to 10,000, more preferably 30 to 5,000, and even more preferably 50 to 1,000.

[0164] Examples of fluorine-based leveling agents that can be used include commercially available products such as Megafac (registered trademark) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F-470, F-471, F-477, F-479, F-482, F-483, F-281, and F-253. F-251, F-114, F-510, F-551, F-552, F-553, F-554, F-555, F-556, F-557, F- 558, F-559, F-560, F-561, F-562, F-563, F-565, F-568, F-569, F-570, F-572, Examples of suitable surfactants include F-574, F-575, F-576, R-40, R-41, R-94, RS-56, RS-72-K, RS-75, RS-76-E, RS-76-NS, RS-78, RS-90, and DS-21 (DIC Corporation); Surflon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, and SA-100 (AGC Seimi Chemical Co., Ltd.); E1830 and E5844 (Daikin Fine Chemicals Research Institute, Inc.); and F-top EF301, F-top EF303, F-top EF351, and F-top EF352 (Mitsubishi Materials Electronic Chemicals Co., Ltd.).

[0165] The content of the fluorine-based leveling agent in the composition for forming a liquid crystal retardation layer is preferably 0.001 to 2 parts by mass, more preferably 0.01 to 1.5 parts by mass, and even more preferably 0.1 to 1.5 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0166] When the composition for forming a liquid crystal retardation layer contains various leveling agents, the amount thereof is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound. The composition for forming an optically anisotropic layer may contain two or more kinds of leveling agents.

[0167] <Polymerization initiator> The liquid crystal retardation layer forming composition may contain a polymerization initiator. The polymerization initiator is a compound that can initiate a polymerization reaction of a polymerizable liquid crystal compound or the like. As the polymerization initiator, a photopolymerization initiator that generates active radicals by the action of light is preferred from the viewpoint that it is not dependent on the phase state of the thermotropic liquid crystal.

[0168] As the photopolymerization initiator, any known photopolymerization initiator can be used as long as it is a compound that can initiate the polymerization reaction of the polymerizable liquid crystal compound.Specific examples include photopolymerization initiators that can generate active radicals or acids by the action of light, and among these, photopolymerization initiators that generate radicals by the action of light are preferred.The photopolymerization initiators can be used alone or in combination of two or more.

[0169] As the photopolymerization initiator, known photopolymerization initiators can be used. For example, photopolymerization initiators that generate active radicals include self-cleavage-type benzoin compounds, acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, oxime ester compounds, acylphosphine oxide compounds, and azo compounds. Hydrogen-abstraction-type benzophenone compounds, alkylphenone compounds, benzoin ether compounds, benzil ketal compounds, dibenzosuberone compounds, anthraquinone compounds, xanthone compounds, thioxanthone compounds, halogenoacetophenone compounds, dialkoxyacetophenone compounds, halogenobisimidazole compounds, halogenotriazine compounds, and triazine compounds. As photopolymerization initiators that generate acids, iodonium salts and sulfonium salts can be used. From the viewpoint of excellent reaction efficiency at low temperatures, self-cleavage type photopolymerization initiators are preferred, and acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, and oxime ester compounds are particularly preferred.

[0170] The content of the polymerization initiator in the liquid crystal retardation layer-forming composition can be appropriately adjusted depending on the type and amount of the polymerizable liquid crystal compound, but is usually 0.1 to 30 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the polymerization initiator is within the above range, polymerization can be carried out without disturbing the alignment of the polymerizable liquid crystal compound.

[0171] <Sensitizer> The liquid crystal retardation layer forming composition may contain a sensitizer. The sensitizer is preferably a photosensitizer. Examples of the sensitizer include xanthone compounds such as xanthone and thioxanthone (e.g., 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene compounds such as anthracene and alkoxy group-containing anthracene (e.g., dibutoxyanthracene, etc.); phenothiazine, rubrene, etc.

[0172] When the composition for forming a liquid crystal retardation layer contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the composition for forming a liquid crystal retardation layer can be further accelerated. The amount of the sensitizer used is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0173] <Antioxidants> From the viewpoint of stably progressing the polymerization reaction, the liquid crystal retardation layer forming composition may contain an antioxidant. The antioxidant can control the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound.

[0174] The antioxidant may be, for example, a primary antioxidant selected from a phenol-based antioxidant, an amine-based antioxidant, a quinone-based antioxidant, or a nitroso-based antioxidant, or a secondary antioxidant selected from a phosphorus-based antioxidant and a sulfur-based antioxidant.

[0175] When the composition for forming a liquid crystal retardation layer contains an antioxidant, the content of the antioxidant is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the content of the polymerizable liquid crystal compound. The antioxidants can be used alone or in combination of two or more. When the content of the antioxidant is within the above range, polymerization can be carried out without disturbing the alignment of the polymerizable liquid crystal compound.

[0176] <Reactive additives> The composition for forming a liquid crystal retardation layer may contain a reactive additive. The reactive additive preferably has a carbon-carbon unsaturated bond, an active hydrogen reactive group, or a thiol group in its molecule. The term "active hydrogen reactive group" as used herein refers to a group reactive to a group having active hydrogen, such as a carboxyl group (-COOH), a hydroxyl group (-OH), or an amino group (-NH2), and typical examples thereof include a glycidyl group, an oxazoline group, a carbodiimide group, an aziridine group, an imide group, an isocyanate group, a thioisocyanate group, and a maleic anhydride group. The reactive additive typically has 1 to 20 reactive groups, preferably 1 to 10 reactive groups.

[0177] (First lamination layer 40) The first attaching layer 40 may be a pressure-sensitive adhesive layer (also called a pressure-sensitive adhesive) or an adhesive layer.

[0178] (Adhesive layer) As the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer, any conventionally known pressure-sensitive adhesive composition having excellent optical transparency can be used without particular limitation, and for example, a pressure-sensitive adhesive composition having a base polymer such as an acrylic resin, a urethane resin, a silicone resin, or a polyvinyl ether resin can be used. Alternatively, an active energy ray-curable pressure-sensitive adhesive composition or a heat-curable pressure-sensitive adhesive composition may be used. Among these, a pressure-sensitive adhesive composition having an acrylic resin as a base polymer, which is excellent in transparency, adhesive strength, removability, weather resistance, heat resistance, etc., is preferred.

[0179] The pressure-sensitive adhesive composition may further contain a crosslinking agent, a silane compound, an antistatic agent, and the like.

[0180] [(Meth)acrylic resin] The (meth)acrylic resin contained in the pressure-sensitive adhesive composition is preferably a polymer (hereinafter also referred to as a "(meth)acrylic acid ester polymer") having as its main component (for example, containing 50 parts by mass or more of the structural unit (I) derived from a (meth)acrylic acid alkyl ester represented by the following formula (I) (hereinafter also referred to as a "structural unit (I)"), per 100 parts by mass of the structural unit of the (meth)acrylic resin:

[0181] In this specification, the term "(meth)acrylic resin" means either an acrylic resin or a methacrylic resin, and the "(meth)" in (meth)acrylate has the same meaning. [ka] [In the formula, R 10 represents a hydrogen atom or a methyl group, and R 20 represents an alkyl group having 1 to 20 carbon atoms, and the alkyl group may have any of a linear, branched, or cyclic structure, and a hydrogen atom of the alkyl group may be substituted with an alkoxy group having 1 to 10 carbon atoms.

[0182] Examples of the (meth)acrylic acid ester represented by formula (I) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, i-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n- Examples of the alkyl acrylate containing an alkoxy group include 2-methoxyethyl (meth)acrylate and ethoxymethyl (meth)acrylate. Examples of the alkyl acrylate containing an alkoxy group include 2-methoxyethyl (meth)acrylate and ethoxymethyl (meth)acrylate. Examples of the alkyl acrylate containing an alkoxy group include 2-ethylhexyl (meth)acrylate and 2-ethylhexyl ...

[0183] The (meth)acrylic acid ester polymer may contain a structural unit derived from a monomer other than the structural unit (I). The structural unit derived from the other monomer may be one type or two or more types. Examples of the other monomer that the (meth)acrylic acid ester polymer may contain include a monomer having a polar functional group, a monomer having an aromatic group, and an acrylamide-based monomer.

[0184] Examples of the monomer having a polar functional group include (meth)acrylates having a polar functional group, such as a hydroxy group, a carboxy group, an amino group substituted with an alkyl group having 1 to 6 carbon atoms or an unsubstituted amino group, and a heterocyclic group such as an epoxy group.

[0185] The content of structural units derived from monomers having polar functional groups in the (meth)acrylic acid ester polymer is preferably 10 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less, even more preferably 0.5 parts by mass or more and 5 parts by mass or less, and particularly preferably 1 part by mass or more and 5 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylic acid ester polymer.

[0186] Examples of the monomer having an aromatic group include (meth)acrylic acid esters having one (meth)acryloyl group and one or more aromatic rings (e.g., benzene ring, naphthalene ring, etc.) in the molecule, and having a phenyl group, phenoxyethyl group, or benzyl group. By including these structural units, it is possible to suppress the white spots that occur in polarizing plates in high-temperature, high-humidity environments.

[0187] The content of structural units derived from monomers having an aromatic group in the (meth)acrylic acid ester polymer is preferably 20 parts by mass or less, more preferably 4 parts by mass or more and 20 parts by mass or less, and even more preferably 4 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylic acid ester polymer.

[0188] Examples of acrylamide monomers include N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, N-(2-methylpropoxymethyl)acrylamide, etc. By including these structural units, it is possible to suppress the bleeding out of additives such as antistatic agents, which will be described later.

[0189] Furthermore, structural units derived from monomers other than the structural unit (I) may include structural units derived from styrene-based monomers, structural units derived from vinyl-based monomers, structural units derived from monomers having multiple (meth)acryloyl groups in the molecule, and the like.

[0190] The weight-average molecular weight (hereinafter also simply referred to as "Mw") of the (meth)acrylic resin (1) is preferably 500,000 to 2,500,000. A weight-average molecular weight of 500,000 or more can improve the durability of the pressure-sensitive adhesive layer in high-temperature, high-humidity environments. A weight-average molecular weight of 2,500,000 or less improves operability when applying a coating liquid containing the pressure-sensitive adhesive composition. The molecular weight distribution (Mw / Mn), expressed as the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (hereinafter also simply referred to as "Mn"), is usually 2 to 10. In this specification, the "weight-average molecular weight" and "number-average molecular weight" are polystyrene-equivalent values ​​measured by gel permeation chromatography (GPC).

[0191] When the (meth)acrylic resin is dissolved in ethyl acetate to form a 20% by mass solution, the viscosity at 25°C is preferably 20 Pa·s or less, and more preferably 0.1 to 15 Pa·s. When the viscosity of the (meth)acrylic resin at 25°C is within this range, it contributes to improved durability and reworkability of a polarizing plate including a pressure-sensitive adhesive layer formed from the resin. The viscosity can be measured using a Brookfield viscometer.

[0192] The glass transition temperature (Tg) of the (meth)acrylic resin is, for example, −60 to 20° C., preferably −50 to 15° C., more preferably −45 to 10° C., and still more preferably −40 to 0° C. The glass transition temperature can be measured by a differential scanning calorimeter (DSC).

[0193] The (meth)acrylic resin may contain two or more types of (meth)acrylic acid ester polymers. Examples of such (meth)acrylic acid ester polymers include (meth)acrylic acid ester polymers having a relatively low molecular weight, such as those containing the structural unit (I) derived from the (meth)acrylic acid ester as the main component, and having a weight-average molecular weight in the range of 50,000 to 300,000.

[0194] (Meth)acrylic resins can usually be produced by known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. In producing (meth)acrylic resins, polymerization is usually carried out in the presence of a polymerization initiator. The amount of polymerization initiator used is usually 0.001 to 5 parts by mass per 100 parts by mass of the total of all monomers constituting the (meth)acrylic resin. (Meth)acrylic resins can also be produced by a method of polymerization using active energy rays such as ultraviolet rays.

[0195] [Crosslinking agent] The pressure-sensitive adhesive composition preferably contains a crosslinking agent, such as a conventional crosslinking agent (e.g., an isocyanate compound, an epoxy compound, an aziridine compound, a metal chelate compound, a peroxide, etc.), and is preferably an isocyanate compound from the viewpoints of the pot life of the pressure-sensitive adhesive composition, the crosslinking rate, and the durability of the polarizing plate.

[0196] The isocyanate compound is a compound having at least two isocyanato groups (-NCO) in the molecule. Specific examples include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, and triphenylmethane triisocyanate. Other examples include adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, as well as dimers and trimers of these isocyanate compounds. Two or more isocyanate compounds may be combined.

[0197] The proportion of the crosslinking agent relative to 100 parts by mass of the (meth)acrylic resin is, for example, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 1 part by mass.

[0198] [Silane compounds] The pressure-sensitive adhesive composition may further contain a silane compound.

[0199] Examples of the silane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

[0200] The silane compound may also contain an oligomer derived from the above silane compound.

[0201] The content of the silane compound in the pressure-sensitive adhesive composition is usually 0.01 to 10 parts by mass, and preferably 0.05 to 5 parts by mass, per 100 parts by mass of the (meth)acrylic resin. When the content of the silane compound is 0.01 part by mass or more, the adhesion between the pressure-sensitive adhesive layer and the adherend tends to be improved, and when the content is 10 parts by mass or less, bleeding out of the silane compound from the pressure-sensitive adhesive layer tends to be suppressed. As the silane compound, a silane coupling agent is preferred, and known silane coupling agents can be used.

[0202] <Antistatic agent> The pressure-sensitive adhesive composition may further contain an antistatic agent. Examples of the antistatic agent include known agents, with ionic antistatic agents being preferred. Examples of the cationic component constituting the ionic antistatic agent include organic cations and inorganic cations. Examples of organic cations include pyridinium cation, imidazolium cation, ammonium cation, sulfonium cation, and phosphonium cation. Examples of inorganic cations include alkali metal cations such as lithium cation, potassium cation, sodium cation, and cesium cation, and alkaline earth metal cations such as magnesium cation and calcium cation. Examples of the anionic component constituting the ionic antistatic agent include either inorganic or organic anions, but an anionic component containing a fluorine atom is preferred because of its excellent antistatic properties. Examples of the anionic component containing a fluorine atom include hexafluorophosphate anion (PF6 - ), bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N - ], bis(fluorosulfonyl)imide anion [(FSO2)2N - ] anions and the like.

[0203] Ionic antistatic agents that are solid at room temperature are preferred in that they provide excellent stability over time of the antistatic performance of the pressure-sensitive adhesive composition.

[0204] The content of the antistatic agent is, for example, 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, and more preferably 1 to 7 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin.

[0205] The pressure-sensitive adhesive composition may contain one or more additives such as an ultraviolet absorber, a solvent, a crosslinking catalyst, a tackifier, a plasticizer, etc. It is also useful to blend an ultraviolet-curable compound into the pressure-sensitive adhesive composition, form a pressure-sensitive adhesive layer, and then cure it by irradiating it with ultraviolet light to form a harder pressure-sensitive adhesive layer.

[0206] The pressure-sensitive adhesive layer can be formed, for example, by dissolving or dispersing the pressure-sensitive adhesive composition in a solvent to prepare a solvent-containing pressure-sensitive adhesive composition, which is then applied to the surface of the layer on which the pressure-sensitive adhesive layer is to be formed, and drying.

[0207] The thickness of the pressure-sensitive adhesive layer is usually 0.1 to 30 μm, preferably 3 to 30 μm, and more preferably 5 to 25 μm.

[0208] (adhesive layer) The adhesive layer may be formed from an adhesive composition.

[0209] Examples of adhesive compositions include aqueous adhesive compositions and curable adhesive compositions that cure upon heating or irradiation with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays. Examples of aqueous adhesive compositions include those in which a polyvinyl alcohol resin or a urethane resin is dissolved in water as the main component, and those in which a polyvinyl alcohol resin or a urethane resin is dispersed in water as the main component. The aqueous adhesive composition may further contain a curable component or crosslinking agent such as a polyaldehyde, a melamine compound, a zirconia compound, a zinc compound, a glyoxal compound, or a water-soluble epoxy resin. Examples of aqueous adhesive compositions include the adhesive composition described in JP 2010-191389 A, the adhesive composition described in JP 2011-107686 A, the composition described in JP 2020-172088 A, and the composition described in JP 2005-208456 A.

[0210] The curable adhesive composition is preferably an active energy ray-curable adhesive composition that contains a curable (polymerizable) compound as a main component and is cured by irradiation with active energy rays. Examples of active energy ray-curable adhesive compositions include cationic polymerization adhesive compositions that contain a cationic polymerizable compound as the curable compound, radical polymerization adhesive compositions that contain a radical polymerizable compound as the curable compound, and hybrid adhesive compositions that contain both a cationic polymerizable compound and a radical polymerizable compound as the curable compound.

[0211] The cationically polymerizable compound is a compound or oligomer that undergoes a cationic polymerization reaction and hardens when exposed to active energy rays such as ultraviolet light, visible light, electron beams, or X-rays or when heated. Specific examples of the cationically polymerizable compound include epoxy compounds, oxetane compounds, and vinyl compounds.

[0212] Examples of epoxy compounds include alicyclic epoxy compounds (compounds having one or more epoxy groups bonded to an alicyclic ring in the molecule) such as 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate; aromatic epoxy compounds (compounds having an aromatic ring and an epoxy group in the molecule) such as diglycidyl ether of bisphenol A; and aliphatic epoxy compounds (compounds having at least one oxirane ring bonded to an aliphatic carbon atom in the molecule) such as 2-ethylhexyl glycidyl ether and 1,4-butanediol diglycidyl ether.

[0213] Examples of the oxetane compound include compounds having one or more oxetane rings in the molecule, such as 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane.

[0214] The cationic polymerization adhesive composition preferably contains a cationic polymerization initiator. The cationic polymerization initiator may be a thermal cationic polymerization initiator or a photo-induced cationic polymerization initiator. Examples of the cationic polymerization initiator include aromatic diazonium salts such as benzenediazonium hexafluoroantimonate; aromatic iodonium salts such as diphenyliodonium tetrakis(pentafluorophenyl)borate; aromatic sulfonium salts such as triphenylsulfonium hexafluorophosphate; and iron-arene complexes such as xylene-cyclopentadienyl iron(II) hexafluoroantimonate. The content of the cationic polymerization initiator is usually 0.1 to 10 parts by mass per 100 parts by mass of the cationic polymerizable compound. Two or more types of cationic polymerization initiators may be used.

[0215] Examples of cationic polymerization adhesive compositions include the cationic polymerization compositions described in JP 2016-126345 A, WO 2019 / 10315 A, and JP 2021-113969 A.

[0216] The radical polymerizable compound is a compound or oligomer that undergoes a radical polymerization reaction and hardens when exposed to active energy rays such as ultraviolet light, visible light, electron beams, or X-rays or when heated, and specific examples thereof include compounds having an ethylenically unsaturated bond. Examples of the compound having an ethylenically unsaturated bond include (meth)acrylic compounds having one or more (meth)acryloyl groups in the molecule and vinyl compounds having one or more vinyl groups in the molecule.

[0217] Examples of the (meth)acrylic compound include (meth)acrylate monomers and (meth)acrylamide monomers each having at least one (meth)acryloyloxy group in the molecule, and (meth)acryl group-containing compounds such as (meth)acrylic oligomers obtained by reacting two or more functional group-containing compounds and each having at least two (meth)acryloyl groups in the molecule. In this specification, (meth)acryloyl means either acryloyl or methacryloyl.

[0218] The radical polymerization adhesive composition preferably contains a radical polymerization initiator. The radical polymerization initiator may be a thermal radical polymerization initiator or a photoradical polymerization initiator. Examples of the radical polymerization initiator include acetophenone-based initiators such as acetophenone and 3-methylacetophenone; benzophenone-based initiators such as benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone; benzoin ether-based initiators such as benzoin propyl ether and benzoin ethyl ether; thioxanthone-based initiators such as 4-isopropylthioxanthone; xanthone, fluorenone, etc. The content of the radical polymerization initiator is usually 0.1 to 10 parts by mass per 100 parts by mass of the radical polymerizable compound. Two or more types of radical polymerization initiators may be used.

[0219] Examples of radical polymerization adhesive compositions include the radical polymerizable compositions described in JP 2016-126345 A, JP 2016-153474 A, and WO 2017 / 183335 A.

[0220] The active energy ray-curable adhesive composition may contain additives such as an ion trapping agent, an antioxidant, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow adjuster, a plasticizer, an antifoaming agent, an antistatic agent, a leveling agent, and a solvent, as needed.

[0221] The adhesive composition and adhesive layer preferably contain a silicone-based or fluorine-based leveling agent as described in the section on the liquid crystal retardation layer. The content of the leveling agent in the adhesive composition and adhesive layer is preferably 0.001 to 2 parts by mass, more preferably 0.01 to 1.5 parts by mass, and even more preferably 0.1 to 1.5 parts by mass, per 100 parts by mass of the solid content.

[0222] The bonding of the first liquid crystal retardation layer and the second liquid crystal retardation layer with an adhesive layer can be performed by applying an adhesive composition to at least one bonding surface selected from the bonding surface of the first liquid crystal retardation layer and the bonding surface of the second liquid crystal retardation layer, stacking the two layers with the coating layer of the adhesive composition interposed therebetween, pressing them together from above and below using a laminating roll or the like, and then drying the adhesive layer, curing it by irradiating it with active energy rays, or curing it by heating.

[0223] Before forming the coating layer of the adhesive layer, at least one of the bonding surfaces selected from the bonding surface of the first liquid crystal retardation layer and the bonding surface of the second liquid crystal retardation layer may be subjected to an easy-adhesion treatment such as a saponification treatment, a corona treatment, a plasma treatment, a primer treatment, or an anchor coating treatment.

[0224] To form a coating layer of the adhesive composition, various coating methods can be used, such as a die coater, a comma coater, a gravure coater, a wire bar coater, or a doctor blade coater.

[0225] The light irradiation intensity when irradiating with active energy rays is determined depending on the composition of the active energy ray-curable adhesive composition and is not particularly limited, but is preferably 10 mW / cm 2 More than 1,000mW / cm 2 The irradiation intensity is preferably an intensity in a wavelength region effective for activating a photocationic polymerization initiator or a photoradical polymerization initiator. Irradiation is performed once or multiple times at such a light irradiation intensity, and the cumulative light amount is 10 mJ / cm or less. 2 It is preferable to set the dose to 100 mJ / cm or more. 2 More than 1,000mJ / cm 2 It is more preferable to set the following:

[0226] The light source used to polymerize and cure the active energy ray-curable adhesive composition is not particularly limited, but examples include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps.

[0227] The thickness of the adhesive layer formed from the aqueous adhesive composition may be, for example, 5 μm or less, preferably 1 μm or less, and more preferably 0.5 μm or less, and may be 0.01 μm or more, and preferably 0.05 μm or more.

[0228] The thickness of the adhesive layer formed from the active energy ray-curable adhesive composition may be, for example, 10 μm or less, preferably 5 μm or less, and more preferably 3 μm or less, or may be 0.1 μm or more, preferably 0.5 μm or more, and more preferably 1 μm or more.

[0229] (Si distribution in each layer) At least one of the first liquid crystal retardation layer (30) and the second liquid crystal retardation layer (50) contains Si atoms, and the atomic concentration of the Si atoms on the surface of at least one of the liquid crystal retardation layers that contains Si atoms, on the side of the first bonding layer (40), is greater than the atomic concentration of the Si atoms at a point 10 nm away from the surface of the liquid crystal retardation layer that is on the side of the first bonding layer (40) in the stacking direction of the polarizing laminate (400).

[0230] Hereinafter, a case where the first liquid crystal retardation layer 30 contains Si atoms will be described. However, the second liquid crystal retardation layer 50 may contain Si atoms, or the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 may contain Si atoms.

[0231] (Distribution of Si atoms on the first bonding layer 40 side in the first liquid crystal retardation layer 30) In this embodiment, the first liquid crystal retardation layer 30 contains Si atoms, and the atomic concentration of Si atoms on the surface of the first liquid crystal retardation layer 30 facing the first bonding layer 40 is higher than the atomic concentration of Si atoms at a point 10 nm away from the surface of the first liquid crystal retardation layer 30 facing the first bonding layer 40 in the stacking direction of the polarizing laminate 400. The difference in atomic concentration may be 0.5 at% or more, 0.7 at% or more, or 1.0 at% or more. However, when both the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 contain Si atoms, the difference in atomic concentration of Si atoms between the surface of the liquid crystal retardation layer and the point 10 nm away from the surface in the stacking direction of the polarizing laminate may exist in only one of the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50, or may exist in both.

[0232] In this specification, the concentration of Si atoms is the atomic ratio measured by XPS measurement, and the elements to be measured are C, F, N, O, and Si.

[0233] The atomic concentration of Si atoms on the surface of the first liquid crystal retardation layer 30 facing the first bonding layer 40 is preferably 10 at% or less, more preferably 6 at% or less, particularly preferably 5.5 at% or less, and even more preferably 4 at% or less. It is also preferably 0.5 at% or more, may be 0.7 at% or more, and more preferably 1.0 at% or more. If the concentration of Si atoms on the surface of the first liquid crystal retardation layer 30 facing the first bonding layer 40 is too high, repelling may occur when applying the first bonding layer-forming composition to the first liquid crystal retardation layer 30 or the first base layer, making it difficult to form the first liquid crystal retardation layer. Furthermore, if the atomic concentration of Si atoms on the surface of the first liquid crystal retardation layer 30 facing the first bonding layer 40 is too high, the surface tension of the first liquid crystal retardation layer-forming composition is significantly reduced, which tends to reduce the adhesion between the first liquid crystal retardation layer formed from the first bonding layer-forming composition and the first bonding layer. When the atomic concentration of Si atoms on the surface of the first liquid crystal retardation layer 30 on the first bonding layer 40 side is 0.5 at % or more, high coatability is obtained, and the occurrence of coating unevenness can be easily suppressed.

[0234] The atomic concentration of Si atoms at a point 10 nm from the surface of the first liquid crystal retardation layer 30 on the first bonding layer 40 side in the lamination direction of the polarizing laminate is preferably less than 0.5 at %.

[0235] (Presence of Si and / or F atoms in the first bonding layer) The first bonding layer does not necessarily contain F and / or Si, but it is preferable that the first bonding layer contains F atoms and / or Si atoms.

[0236] When the first attaching layer is a cured layer of an adhesive composition, examples of the Si and F source include the above-mentioned leveling agents.

[0237] When the first attaching layer is a pressure-sensitive adhesive layer, for example, the Si source may be a silane compound.

[0238] The first bonding layer may contain F atoms and / or Si atoms uniformly, or may be segregated on the surface on the liquid crystal retardation layer side.

[0239] For example, when the Si source in the first bonding layer is a silane compound or the like, Si atoms are usually contained uniformly.

[0240] On the other hand, when the F source and Si source in the first bonding layer are leveling agents, F atoms and / or Si atoms often segregate on the surface on the liquid crystal retardation layer side. An example of segregation is an embodiment in which the total atomic concentration of F atoms and / or Si atoms on the surface on the first liquid crystal retardation layer 30 side and / or the second liquid crystal retardation layer 50 side of the first bonding layer 40 is greater than the total atomic concentration of F atoms and Si atoms at a point 10 nm away from the surface of the first bonding layer 40 in the stacking direction of the optical laminate 100.

[0241] (Distribution of Si atoms on the first bonding layer 40 side in the second liquid crystal retardation layer 50) It is preferable that the second liquid crystal retardation layer 50 contains Si atoms, and that the atomic concentration of the Si atoms on the surface of the second liquid crystal retardation layer 50 facing the first bonding layer 40 is higher than the atomic concentration of the Si atoms at a point 10 nm away from the surface of the second liquid crystal retardation layer 50 facing the first bonding layer 40 in the stacking direction of the polarizing laminate 400. The difference in atomic concentration may be 0.5 at% or more, 0.7 at% or more, or 1.0 at% or more.

[0242] When the second liquid crystal retardation layer 50 contains Si atoms, the atomic concentration of Si atoms on the surface of the second liquid crystal retardation layer 50 facing the first bonding layer 40 can be made the same as the atomic concentration of Si atoms on the surface of the first liquid crystal retardation layer 30 facing the first bonding layer 40 when the above-mentioned first liquid crystal retardation layer 30 contains Si.

[0243] The atomic concentration of Si atoms at a point 10 nm from the surface of the second liquid crystal retardation layer 50 on the first bonding layer 40 side in the lamination direction of the polarizing laminate is preferably less than 0.5 at %.

[0244] (Relationship between the combination of the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 and the first attaching layer 40)

[0245] When the first liquid crystal retardation layer 30 contains Si atoms, the first bonding layer 40 may contain either F atoms or Si atoms, but it is preferable that the first bonding layer 40 contains Si atoms.

[0246] When the second liquid crystal retardation layer 50 contains Si atoms, the first bonding layer 40 may contain either F atoms or Si atoms, but it is preferable that the first bonding layer 40 contains Si atoms.

[0247] Furthermore, when the first liquid crystal retardation layer 30 contains Si atoms and the atomic concentration of Si atoms in the surface of the second liquid crystal retardation layer 50 on the first bonding layer 40 side is higher than the atomic concentration of Si atoms at a point 10 nm from the surface of the second liquid crystal retardation layer 50 on the first bonding layer 40 side in the stacking direction of the polarizing laminate, it is preferable that the atomic concentration of Si atoms in at least one surface of the first liquid crystal retardation layer 30 is higher than the atomic concentration of Si atoms at a point 10 nm from the surface of the first liquid crystal retardation layer 30 in the stacking direction of the polarizing laminate. The surface of the first liquid crystal retardation layer 30 may be the surface on the first bonding layer 40 side or the surface on the second bonding layer 150 side. Even when the surface is the surface on the second bonding layer 150 side, the atomic concentration of Si atoms in the surface can be the same as the atomic concentration of Si atoms in the surface on the first bonding layer 40 side described above.

[0248] When the first bonding layer 40 contains F atoms and Si atoms, the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 can each independently contain F atoms and / or Si atoms.

[0249] When the first bonding layer 40 contains Si atoms, it is preferable that the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 each contain Si atoms.

[0250] When the first bonding layer 40 contains F atoms, the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 can each independently contain Si atoms.

[0251] It is preferable that the first liquid crystal retardation layer 30, the second liquid crystal retardation layer 50, and the first bonding layer 40 each contain Si atoms.

[0252] (Second lamination layer 150) The second bonding layer 150 is disposed between the polarizing plate 200 and the retardation layer laminate 300 to bond them together. As shown in Fig. 1, the second bonding layer 150 may be disposed on the first liquid crystal retardation layer 30 side of the retardation layer laminate 300, or as shown in Fig. 2, the second bonding layer 150 may be disposed on the second liquid crystal retardation layer 50 side of the retardation layer laminate 300. 1, the second bonding layer 150 bonds the polarizing plate 200 and the first alignment film 20 of the retardation layer laminate 300, and when the retardation layer laminate 300 does not have the first alignment film 20, the second bonding layer 150 can bond the polarizing plate 200 and the first liquid crystal retardation layer 30. In FIG. 1, the first alignment film 20 may be disposed between the first liquid crystal retardation layer 30 and the first bonding layer 40. 2, the second attaching layer 150 attaches the polarizing plate 200 and the second alignment film 60 of the retardation layer laminate 300, and when the retardation layer laminate 300 does not have the second alignment film 60, the second attaching layer 150 can attach the polarizing plate 200 and the second liquid crystal retardation layer 50. In FIG. 2, the second alignment film 60 may be disposed between the second liquid crystal retardation layer 50 and the first attaching layer 40.

[0253] The material of the second attaching layer 150 may be a pressure-sensitive adhesive or an adhesive, and any of the materials listed above for the first attaching layer 40 can be used as appropriate. The thickness of the second attaching layer can be 2 μm or more and 20 μm or less when a pressure-sensitive adhesive is used, and 1 μm or more and 10 μm or less when an adhesive is used.

[0254] The second bonding layer 150 must have a storage modulus of 0.03 MPa or more at 23°C and 1 Hz. The storage modulus can be measured by the method described in the Examples below. The storage modulus may be 0.05 MPa or more, more than 0.05 MPa, 0.07 MPa or more, 0.10 MPa or more, or 0.12 MPa or more. The storage modulus may also be less than 1.00 MPa, 0.90 MPa or less, 0.80 MPa or less, 0.70 MPa or less, 0.60 MPa or less, or 0.50 MPa or less.

[0255] (outer adhesive layer) As shown in FIGS. 1 and 2, the polarizing laminate 400 can have an outer pressure-sensitive adhesive layer 500 on the side opposite to the second attaching layer 150 with respect to the retardation layer laminate 300 . There are no particular limitations on the material or thickness of the outer pressure-sensitive adhesive layer 500, and for example, those listed for the first attaching layer can be used as appropriate. The thickness of the outer pressure-sensitive adhesive layer can be 1 μm or more and 100 μm or less, and is preferably 5 μm or more and 50 μm or less. The outer pressure-sensitive adhesive layer preferably contains a silane compound, and particularly preferably contains a silane coupling agent, which may be a known silane coupling agent.

[0256] (Method of manufacturing polarizing laminate) First, an optical laminate 100 having the structure shown in FIG. 3 is manufactured. The optical laminate 100 has a layered structure of a first laminate 90A / first bonding layer 40 / second laminate 90B. The first laminate 90A has a layered structure of a first base material layer 10 / first alignment film 20 / first liquid crystal retardation layer 30. The second laminate 90B has a layered structure of a second base material layer 70 / second alignment film 60 / second liquid crystal retardation layer 50. The first laminate 90A and the second laminate 90B are bonded together by the first bonding layer 40 so that the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 face each other.

[0257] (Method of manufacturing the optical laminate 100) The optical laminate 100 can be produced, for example, as follows. First, a composition for forming a first alignment film is applied to the surface of the first base layer 10, and an alignment process such as light irradiation is performed to form the first alignment film 20. If necessary, the surface of the first alignment film 20 is subjected to corona treatment or the like. Next, a composition for forming a first liquid crystal retardation layer is applied to the first alignment film 20, and polymerized by light irradiation or the like to form the first liquid crystal retardation layer 30. In this way, a first laminate 90A having the first base layer 10 / first alignment film 20 / first liquid crystal retardation layer 30 is obtained.

[0258] Next, a composition for forming a second alignment film is applied to the surface of the second base layer 70, and an alignment process such as light irradiation is performed to form the second alignment film 60. If necessary, the surface of the second alignment film 60 is subjected to corona treatment or the like. Next, a composition for forming a second liquid crystal retardation layer is applied to the second alignment film 60, and polymerized by light irradiation or the like to form the second liquid crystal retardation layer 50. In this way, a second laminate 90B having the second base layer 70 / second alignment film 60 / second liquid crystal retardation layer 50 is obtained.

[0259] (First base material layer 10 and second base material layer 70) Examples of the substrate layer include glass and resin films, with resin films being preferred, and long rolled resin films being more preferred in terms of continuous production. Examples of resins constituting the resin film include polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; cyclic olefin-based resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid esters; polyacrylic acid esters; cellulose esters such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyether ketone; polyphenylene sulfide, and polyphenylene oxide; and other plastics. Among these, from the viewpoint of transparency when used in optical film applications, a resin film selected from triacetyl cellulose, cyclic olefin-based resins, polymethacrylic acid esters, and polyethylene terephthalate is more preferred.

[0260] Examples of commercially available cellulose ester substrate layers include "Fujitac Film" (manufactured by Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (all manufactured by Konica Minolta Opto, Inc.).

[0261] Examples of commercially available cyclic olefin resin films include "Topas" (registered trademark) (manufactured by Ticona GmbH, Germany), "Arton" (registered trademark) (manufactured by JSR Corporation), "ZEONOR" (registered trademark), "ZEONEX" (registered trademark) (all manufactured by Zeon Corporation), and "Apel" (registered trademark) (manufactured by Mitsui Chemicals, Inc.). Such cyclic olefin resins can be formed into a film by known means such as solvent casting or melt extrusion to form a substrate layer. Commercially available cyclic olefin resin substrate layers can also be used. Examples of commercially available cyclic olefin resin substrate layers include "S-Cina" (registered trademark), "SCA40" (registered trademark) (all manufactured by Sekisui Chemical Co., Ltd.), "ZEONORFILM" (registered trademark) (manufactured by Optes Co., Ltd.), and "ArtonFILM" (registered trademark) (manufactured by JSR Corporation).

[0262] The thickness of the substrate layer is preferably thin enough to allow practical handling, but if it is too thin, the strength decreases and processability tends to be poor. The thickness of the substrate layer is usually 5 μm or more, preferably 10 μm or more, more preferably 30 μm or more, and usually 300 μm or less, preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 120 μm or less. A substrate film thickness of 5 μm or more imparts strength. On the other hand, a thickness of 300 μm or less can suppress an increase in processing waste and wear of the cutting blade when cutting the substrate film into sheet-like substrate films. In addition, by peeling off the substrate layer and transferring a polarizing film or retardation film, a further thinning effect can be obtained.

[0263] The first substrate layer 10 and the second substrate layer 70 may be made of different materials or the same material, and may have different thicknesses or the same thickness.

[0264] Next, the first liquid crystal retardation layer 30 of the first laminate 90A and the second liquid crystal retardation layer 50 of the second laminate 90B are bonded together using a bonding material such as a pressure-sensitive adhesive layer or an adhesive layer. For example, in the case of a UV adhesive layer, the first liquid crystal retardation layer 30 of the first laminate 90A and the second liquid crystal retardation layer 50 of the second laminate 90B may be laminated together via the UV adhesive layer, and then irradiated with UV light.

[0265] When a silicone-based leveling agent is added to the composition for forming a liquid crystal retardation layer, the silicone-based leveling agent segregates on the surface of the liquid crystal retardation layer opposite to the substrate layer when the composition is applied to the substrate layer, and the above-mentioned distribution of Si atoms is easily formed in the liquid phase retardation layer.

[0266] The silicone-based leveling agent is difficult to remove from the liquid crystal retardation layer in the form of gas during corona treatment of the surface of the liquid crystal retardation layer.

[0267] For example, if the composition for forming the bonding layer contains Si atoms and / or F atoms, such as when a silicone-based or fluorine-based leveling agent is added to the adhesive composition, or when a silane compound is contained in the solvent-containing pressure-sensitive adhesive composition, it is easy to realize a first bonding layer containing F atoms and / or Si atoms.

[0268] Furthermore, if the liquid crystal retardation layer and the composition for forming the laminating layer contain silicone-based or fluorine-based leveling agents, which are thought to have similar properties, they tend to wet and spread easily, possibly due to the affinity (interaction) that occurs between Si atoms and between F-Si atoms.

[0269] Next, the first base material layer 10 and the second base material layer 70 are removed from the optical laminate 100 to obtain the retardation layer laminate 300. At this time, the first alignment film 20 may be removed together with the first base material layer 10, or the second alignment film 60 may be removed together with the second base material layer 70.

[0270] Next, the polarizing plate 200 and the retardation layer laminate 300 are bonded together via the second bonding layer 150 using a known method, and an outer adhesive layer 500 is formed on the side of the retardation layer laminate 300 opposite the polarizing plate 200 using a known method.

[0271] It is also possible to manufacture a polarizing laminate without manufacturing the optical laminate 100. For example, by performing an operation of bonding the surfaces of the first laminate 90A and the second laminate 90B on the liquid crystal retardation layer side via the respective bonding layers and then removing the base layer on the polarizing plate 200 in this order, it is possible to obtain the polarizing plate 200 / second bonding layer 150 / first liquid crystal retardation layer 30 / first alignment film 20 / first bonding layer 40 / second liquid crystal retardation layer 50 / second alignment film 60 / outer pressure-sensitive adhesive layer 500. At this time, the first alignment film 20 may be removed together with the first base layer 10, or the second alignment film 60 may be removed together with the second base layer 70.

[0272] (Mechanism of action) This embodiment has the following advantages.

[0273] According to this embodiment, at least one or both of the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 contains Si atoms, and the atomic concentration of the Si atoms on the surface of at least one of the liquid crystal retardation layers that contains Si atoms, which is on the first bonding layer 40 side, is higher than the atomic concentration of the Si atoms at a point 10 nm from the surface of the liquid crystal retardation layer that is on the first bonding layer 40 side in the stacking direction of the polarizing laminate 400, and the storage modulus of the second bonding layer at 23°C and 1 Hz is 0.03 MPa or more, thereby improving the durability of the polarizing laminate, particularly the durability in a crosshatch test from the linear polarizer side.

[0274] The reason for this is unclear, but the following is thought to be the reason. The above condition means that Si atoms are unevenly distributed near the surface of at least one liquid crystal retardation layer on the first bonding layer 40 side. When a first bonding layer-forming composition is applied to the surface of a liquid crystal retardation layer that satisfies the above condition, the Si atoms unevenly distributed on the surface on the first bonding layer 40 side reduce the surface tension of the liquid crystal retardation layer, improving the coatability of the first bonding layer-forming composition and reducing coating unevenness on the surface on the first bonding layer 40 side of the liquid crystal retardation layer. As a result, the occurrence of uncoated areas can be suppressed, thereby suppressing poor adhesion and reduced adhesion between the liquid crystal retardation layer and the first bonding layer 40. Furthermore, because the second bonding layer is hard, when an external force is applied during peeling, the effect of the external force is less likely to be transmitted to layers below the second bonding layer, thereby suppressing peeling between the layers of the retardation laminate below the second bonding layer. The combination of these factors is thought to improve durability in a crosshatch test from the linear polarizer side. In particular, when both the first liquid crystal retardation layer 30 and the second liquid crystal retardation layer 50 contain Si atoms and the atomic concentration of Si atoms on the surface of each liquid crystal retardation layer facing the first bonding layer 40 is greater than the atomic concentration of Si atoms at a point 10 nm away from the surface of each liquid crystal retardation layer facing the first bonding layer 40 in the stacking direction of the optical laminate, the adhesion between the surface of the first liquid crystal retardation layer 30 facing the first bonding layer 40 and the surface of the second liquid crystal retardation layer 50 facing the first bonding layer 40 is improved, which is more preferable.

[0275] Furthermore, when the first bonding layer 40 contains F atoms and / or Si atoms, durability in a crosshatch test from the linear polarizer side is further improved. The reason for this is also unclear, but it is presumed to be due to the interaction between the F atoms or Si atoms of the first bonding layer 40 and the Si atoms near the surface of the first liquid crystal retardation layer 30.

[0276] Furthermore, when the thickness of the second protective layer 190 is 30 μm or less, there is an effect of improving bending adhesion. The reason for this is thought to be as follows: When the protective layer is bent to the same angle, a thicker protective layer is subjected to more stress, which is thought to make it more likely to peel off.

[0277] Furthermore, if the luminous efficiency corrected transmittance Ty of the linear polarizer 220 is 41.5% or more, there is an effect of improving the appearance. The reason for this is thought to be as follows: To increase the transmittance of a linear polarizer, it is necessary to reduce the amount of iodine complex in the polarizer by adjusting the dyeing time, etc. In this case, the color change during durability increases, so compared to polarizers with low transmittance, it is necessary to change the balance of the iodine complex and make the color bluer. The overall blue color hides unevenness in the retardation and improves the overall appearance.

[0278] Furthermore, when the outer pressure-sensitive adhesive layer contains a silane compound, the peel test results are improved. The reasons for this are thought to be as follows. It can be inferred that when the second alignment film 60, which is fixed in contact with the outer adhesive layer 500, or the second liquid crystal retardation layer 50 when the second alignment film 60 is not present, contains Si atoms or the like due to a Si leveling agent or the like, the Si atoms segregate toward the outer adhesive layer of the second alignment film 60 or the second liquid crystal retardation layer 50, and exhibit strong interaction due to their high affinity with the Si component of the silane compound of the outer adhesive layer 500.

[0279] <Image display device> The image display device includes a polarizing laminate and an image display element (such as an organic EL display element). The optical laminate is disposed on the viewing side of the image display element (image display cell). The optical laminate can be attached to the image display element using a pressure-sensitive adhesive layer.

[0280] The image display device is not particularly limited, and examples thereof include organic electroluminescence (organic EL) display devices, inorganic electroluminescence (inorganic EL) display devices, liquid crystal display devices, and electroluminescence display devices.

[0281] The image display device can be used as mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic signs, measuring instruments or meters, office equipment, medical equipment, computing equipment, and the like. [Example]

[0282] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples. Unless otherwise specified, "%" and "parts" in the examples mean % by mass and parts by mass, respectively.

[0283] Example 1 (Production of a first laminate having a first substrate layer, a first alignment film, and a first liquid crystal retardation layer)

[0284] [Preparation of composition for forming first alignment film] The photo-alignment material (weight average molecular weight: 50,000, m:n = 50:50) with the following structure was produced in accordance with the method described in JP 2021-196514 A. Two parts of the photo-alignment material and 98 parts of cyclopentanone (solvent) were mixed as components, and the resulting mixture was stirred at 80°C for 1 hour to prepare a composition for forming a first alignment film. Photoalignable materials: [ka]

[0285] [Preparation of composition for forming first liquid crystal retardation layer] Polymerizable liquid crystal compound (A1) and polymerizable liquid crystal compound (A2) having the structures shown below were prepared. Polymerizable liquid crystal compound (A1) was prepared in the same manner as described in JP-A-2019-003177. Polymerizable liquid crystal compound (A2) was prepared in the same manner as described in JP-A-2009-173893. Polymerizable liquid crystal compound (A1): [ka] Polymerizable liquid crystal compound (A2): [ka]

[0286] Polymerizable liquid crystal compound (A1) and polymerizable liquid crystal compound (A2) were mixed in a mass ratio of 90:10 to obtain a mixture. To 100 parts of the obtained mixture, 0.1 parts of a silicone leveling agent "BYK-UV3500" (manufactured by BYK-Chemie, a polyether-modified polydimethylsiloxane having an acrylic functional group) and 3 parts of a photopolymerization initiator "Irgacure OXE-03" (manufactured by BASF Japan Ltd.) were added. Furthermore, N-methyl-2-pyrrolidone (NMP) was added to obtain a solids concentration of 13%. The mixture was stirred at 80°C for 1 hour to prepare a composition for forming a first liquid crystal retardation layer.

[0287] [Table 1]

[0288] [Production of first laminate] The composition for forming the first alignment film was applied to a 100 μm-thick polyethylene terephthalate (PET) film as the first base layer 10 using a bar coater. The resulting coating was dried at 120° C. for 2 minutes and then cooled to room temperature to form a dry coating. Then, using a UV irradiation device (SPOT CURE SP-9; manufactured by Ushio Inc.), 100 mJ of polarized ultraviolet light (313 nm standard) was irradiated to obtain a first alignment film 20. The film thickness of the first alignment film 20 was measured using an ellipsometer M-220 manufactured by JASCO Corporation and was 100 nm.

[0289] A composition for forming a first liquid crystal retardation layer was applied onto the obtained first alignment film 20 using a bar coater to form a coating film. This coating film was dried by heating at 120°C for 2 minutes and then cooled to room temperature to obtain a dried film. Next, using a high-pressure mercury lamp ("Uniqure VB-15201BY-A" manufactured by Ushio Inc.), ultraviolet light was irradiated to the dried film at an exposure dose of 500 mJ / cm2 (based on 365 nm) under a nitrogen atmosphere to form a retardation layer in which the polymerizable liquid crystal compound was cured in a state of being aligned horizontally relative to the substrate surface, thereby obtaining a first laminate consisting of a first substrate layer / first alignment film / first liquid crystal retardation layer (cured horizontally aligned liquid crystal film). The film thickness of the first liquid crystal retardation layer was measured using a laser microscope LEXTOLS4100 manufactured by Olympus Corporation and was 2.0 μm.

[0290] The liquid crystal side of the first laminate was subjected to corona treatment, and the laminate was attached to glass using a 25 μm pressure-sensitive adhesive manufactured by Lintec Corporation, and the first substrate layer was peeled off and removed. The in-plane retardation value of the first liquid crystal retardation layer was measured using a KOBRA-WR manufactured by Oji Scientific Instruments. The in-plane retardation values ​​for light with wavelengths of 450 nm, 550 nm, and 650 nm were calculated using Cauchy's dispersion formula obtained from the measurement results of the in-plane retardation values ​​for light with wavelengths of 448.2 nm, 498.6 nm, 548.4 nm, 587.3 nm, 628.7 nm, and 748.6 nm. As a result, the in-plane retardation values ​​of the first liquid crystal retardation layer were Re(450)=122 nm, Re(550)=140 nm, and Re(650)=144 nm, and the relationship between the in-plane retardation values ​​at each wavelength was as follows: Re(450) / Re(550)=0.87 Re(650) / Re(550)=1.03 (In the formula, Re(450) represents the in-plane retardation value for light with a wavelength of 450 nm, Re(550) represents the in-plane retardation value for light with a wavelength of 550 nm, and Re(650) represents the in-plane retardation value for light with a wavelength of 650 nm.) The first liquid crystal retardation layer was a reverse wavelength dispersion λ / 4 plate.

[0291] In this way, a first laminate including the first base material layer, the first alignment film, and the first liquid crystal retardation layer in this order was obtained.

[0292] (Production of a second laminate having a second substrate layer, a second alignment film, and a second liquid crystal retardation layer)

[0293] [Preparation of composition for forming second alignment film] 2-butoxyethanol was added to a commercially available alignment polymer, Sunever SE-610 (manufactured by Nissan Chemical Industries, Ltd.), to a solid content of 1%. 0.1 parts of a silicone leveling agent, BYK-UV3500 (a polyether-modified polydimethylsiloxane having an acrylic functional group), was then added to 100 parts of the resulting mixture to obtain a composition for forming a second alignment film.

[0294] [Preparation of composition for forming second liquid crystal retardation layer] The polymerizable liquid crystal compound Paliocolor LC242 (manufactured by BASF Japan), the silicone leveling agent "BYK-UV3500" (manufactured by BYK-Chemie, a polyether-modified polydimethylsiloxane with acrylic functional groups), and the photopolymerization initiator "Omnirad907" (manufactured by IGM Resin BV) were added. Furthermore, propylene glycol 1-monomethyl ether 2-acetate (PGME) was added, and the mixture was stirred at a temperature of 80°C for 1 hour to prepare a composition for forming a second liquid crystal retardation layer.

[0295] [Table 2] Polymerizable liquid crystal compound LC242: [ka]

[0296] [Production of second laminate] A 38 μm-thick polyethylene terephthalate film was subjected to corona treatment using a corona treatment device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.), and the surface was then coated with a composition for forming a second alignment film using a bar coater and dried at 90°C for 1 minute. The thickness of the resulting second alignment film was measured using a laser microscope and found to be 30 nm. Subsequently, a composition for forming a second liquid crystal retardation layer was coated on the second alignment film using a bar coater and dried at 90°C for 1 minute, followed by exposure to 1000 mJ / cm2 under a nitrogen atmosphere using a high-pressure mercury lamp ("Uniquer VB-15201BY-A" manufactured by Ushio Inc.). 2 A second liquid crystal retardation layer was obtained by irradiating the dried coating with ultraviolet light (365 nm as the reference wavelength). The film thickness was measured using a laser microscope, and found to be 450 nm. The retardation values ​​of the second liquid crystal retardation layer were measured using a KOBRA-WR manufactured by Oji Scientific Instruments. The results were Re(550) = 1 nm and Rth(550) = -70 nm. Therefore, the layer had the optical properties expressed by the following formula (3). Since the retardation value of PET at a wavelength of 550 nm is approximately 0, this does not affect the optical properties. nx≒ny <nz (3) The second liquid crystal retardation layer was a positive C layer.

[0297] In this way, a second laminate was obtained which included the second base layer, the second alignment film, and the second liquid crystal retardation layer in this order.

[0298] [Manufacturing of optical laminates] [Preparation of UV-curable adhesive] (1) Preparation of UV-curable adhesive 1 The following components were blended and mixed, and then degassed to prepare UV-curable adhesive 1.

[0299] (cationically polymerizable compound) 3',4'-Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Corporation): 70 parts Neopentyl glycol diglycidyl ether (product name: EX-211, manufactured by Nagase ChemteX Corporation): 20 parts 2-Ethylhexyl glycidyl ether (product name: EX-121, manufactured by Nagase ChemteX Corporation): 10 parts (Cationic photopolymerization initiator) Product name: CPI-100 (San-Apro Co., Ltd., 50% propylene carbonate solution): 4.5 parts (actual solids: 2.25 parts) (Photosensitizing agent) 1,4-diethoxynaphthalene: 2 parts (Silicone leveling agent) Product name: SH710 (Methylphenyl polysiloxane, manufactured by Toray Dow Corning Co., Ltd.): 0.25 parts Product name

[0300] [Manufacturing of optical laminates] After corona treatment (800 W, 10 m / min, bar width 700 mm, 1 pass) was performed on the liquid crystal retardation layer side surfaces of the first laminate and the second laminate, the liquid crystal retardation layers (the surfaces opposite the substrate layer) were bonded together via the above-mentioned UV-curable adhesive layer. The laminate was then irradiated with UV light to cure the UV-curable adhesive. In this way, an optical laminate including the first substrate layer / first alignment film / first liquid crystal retardation layer / first bonding layer / second liquid crystal retardation layer / second alignment film / second substrate layer was produced.

[0301] (Creating a linear polarizer)

[0302] (Creating a linear polarizer) A polyvinyl alcohol film with a thickness of 20 μm, a degree of polymerization of 2,400, and a degree of saponification of 99.9% or more was uniaxially stretched to a stretching ratio of 4.5 times in a dry state, and while maintaining tension, it was immersed for 60 seconds at 28°C in a dye bath containing 0.05 parts by weight of iodine and 5 parts by weight of potassium iodide per 100 parts by weight of water.

[0303] Next, the film was immersed in a boric acid aqueous solution 1 containing 5.5 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water at 64° C. for 155 seconds. Next, the film was immersed in a boric acid aqueous solution 2 containing 5.5 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water at 67° C. for 30 seconds. Thereafter, the film was washed with pure water at 3° C. and dried to obtain a linear polarizer having a thickness of 8 μm.

[0304] The linear polarizer had a luminous efficiency-corrected single transmittance of 41.7% and a luminous efficiency-corrected polarization degree of 99.995%. The linear polarizer had a single hue a* of -0.88 and a single hue b* of 3.69. The linear polarizer had a shrinkage stress of 99.9 N / mm2.

[0305] (Preparation of the first protective layer) A temporary protective film consisting of a 15 μm thick adhesive layer and a 38 μm polyethylene terephthalate substrate film was attached to one side of a cycloolefin polymer (COP) film (Zeon Corporation, ZF-14, thickness 23 μm).

[0306] (Formation of surface protective layer (hard coat layer) on exposed surface of first protective layer)

[0307] An acrylic polymer in which a sesamol-type benzotriazole compound serving as an ultraviolet absorber was reactively bonded to MMA and a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (product name "KAYARADDPHA", manufactured by Nippon Kayaku Co., Ltd.) were mixed in a solid mass ratio of 45:55, to which 4 parts by weight of a polymerization initiator (Omnirad184 manufactured by IGMResins B.V. and ESACUREONE manufactured by DKSH Japan K.K. in a mass ratio of 50:50) and 0.2 parts by weight of a silicone-based leveling agent (product name "BKY-UV3500", manufactured by BYK) were added and stirred thoroughly to prepare a composition for forming a hard coat layer.

[0308] The hard coat layer-forming composition was then applied to the exposed surface of the COP film using a Mayer bar to form a coating. Dry air at 70°C was passed through the coating at a flow rate of 0.5 m / s for 30 seconds to evaporate the solvent, and the coating was then cured by irradiating it with ultraviolet light in a nitrogen atmosphere (oxygen concentration 200 ppm or less) at an integrated dose of 200 mJ / cm2 to form a 5 μm-thick hard coat layer. This resulted in a laminated film comprising, in this order, a temporary protective film for the PET substrate, an adhesive layer, a cycloolefin polymer film, and a hard coat layer.

[0309] (Manufacturing of linear polarizing plates) The temporary protective film of the PET substrate was peeled off from the laminated film with the hard coat layer, along with the adhesive layer, while the peeled surface was subjected to corona treatment. The resulting film was then bonded to one side of the linear polarizer obtained above using a nip roll with a water-based adhesive. A saponified triacetyl cellulose (TAC) film (ZRG20SL, manufactured by Fujifilm Corporation, 20 μm thick) was then bonded to the other side of the linear polarizer using a nip roll with a water-based adhesive. The resulting laminate was dried at 60°C for 2 minutes while maintaining a tension of 430 N / m, yielding a linear polarizing plate with protective layers on both sides of the linear polarizer. The water-based adhesive used here was prepared by adding 3 parts by weight of carboxy-modified polyvinyl alcohol (Kuraray Poval KL318, manufactured by Kuraray Co., Ltd.) and 1.5 parts by weight of a water-soluble polyamide epoxy resin (Sumirez Resin 650, manufactured by Taoka Chemical Co., Ltd., 30% solids aqueous solution) to 100 parts of water.

[0310] (Manufacturing of circular polarizing plates) The first base layer on the first liquid crystal retardation layer side was peeled off from the optical laminate, and a 5 μm-thick acrylic adhesive layer (adhesive layer 1) was used as a second laminating layer to laminate it onto the TAC film side of the linear polarizer. This resulted in an optical laminate including a hard coat layer, a COP film (first protective layer), a polarizing film, a TAC film (second protective layer), a second laminating layer (adhesive layer 1), a first alignment film, a first liquid crystal retardation layer, a first laminating layer (ultraviolet-curable adhesive layer), a second liquid crystal retardation layer, a second alignment film, and a PET film. Thereafter, the outermost PET film was peeled off, and a 25 μm-thick acrylic adhesive layer (adhesive layer 3) was laminated on the second alignment film as an outer adhesive layer. In this way, a circularly polarizing plate including a hard coat layer, a COP film (first protective layer), a polarizing film, a TAC film (second protective layer), a second attaching layer (adhesive layer 1), a first alignment film, a first liquid crystal retardation layer, a first attaching layer (ultraviolet-curable adhesive layer), a second liquid crystal retardation layer, a second alignment film, and an outer adhesive layer was obtained.

[0311] (Preparation of Pressure-Sensitive Adhesive Layer 1 Used as Second Adhesive Layer) (1) Preparation of acrylic resin solution 1 A reaction vessel equipped with a condenser, nitrogen inlet, thermometer, and stirrer was charged with a mixed solution of 100 parts ethyl acetate, 99.0 parts butyl acrylate, 0.5 parts 2-hydroxyethyl acrylate, and 0.5 parts acrylic acid. The air in the vessel was purged with nitrogen gas to remove oxygen, and the internal temperature was raised to 55°C. A solution of 0.12 parts azobisisobutyronitrile (polymerization initiator) in 10 parts ethyl acetate was then added in its entirety. After the addition of the polymerization initiator, the temperature was maintained for 1 hour. Ethyl acetate was then continuously added to the reaction vessel at a rate of 17.3 parts / hour while maintaining the internal temperature at 54-56°C. The addition of ethyl acetate was stopped when the (meth)acrylic resin concentration reached 35% by mass, and the mixture was then maintained at this temperature for 6 hours. Finally, ethyl acetate was added to adjust the (meth)acrylic resin concentration to 20% by mass, preparing Acrylic Resin Solution 1. The resulting acrylic resin had a weight average molecular weight Mw of 1.7 million and a molecular weight distribution Mw / Mn of 3.9. Mw and Mn were measured using a GPC system with a TSKgel GMH column manufactured by Tosoh Corporation. HR Two "-H(S)" tubes were connected in series, and tetrahydrofuran was used as the eluent. Measurements were performed in terms of standard polystyrene under the following conditions: sample concentration 2 mg / mL, sample introduction volume 100 μL, temperature 40°C, and flow rate 1 mL / min.

[0312] (2) Preparation of Pressure-Sensitive Adhesive Composition 1 To 80 parts by solid content of the acrylic resin solution 1 obtained in (1), 20 parts (solid content) of a bifunctional acrylate (obtained from Shin-Nakamura Chemical Co., Ltd.; product number "A-DOG"), 2.5 parts based on the active ingredient 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)), 1.5 parts of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals: trade name "Irgacure 500"), and 0.3 parts of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.: trade name "KBM-403") were added, and further ethyl acetate was added so that the solid content concentration became 13% to obtain an 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]

[0313] (3) Preparation of Adhesive Layer 1 The adhesive composition 1 prepared in (2) above was applied to the release-treated surface of a separate film made of a polyethylene terephthalate film with a release treatment (obtained from Lintec Corporation's "PLZ-383030") 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 (adhesive sheet). Next, the surface of the obtained adhesive layer on the side opposite to the separator film was bonded to the release-treated surface of a separate film made of a polyethylene terephthalate film with a release treatment (obtained from Lintec Corporation's "PLR-381031"). Subsequently, ultraviolet rays were irradiated under the following conditions to prepare an adhesive layer 1. The storage elastic modulus of the adhesive layer at a temperature of 23 °C and 0.1 Hz was 0.125 MPa. The storage elastic modulus was measured by the method described in the examples below. <UV Irradiation Conditions> ·Using a Fusion UV lamp system (manufactured by Fusion UV Systems) H bulb ·Integrated light amount 250 mJ / cm2

[0314] (Preparation of Pressure-Sensitive Adhesive Layer 2 Used in Second Attachment Layer of Comparative Example 2 Described Later) (1) Preparation of acrylic resin solution 2 A reaction vessel equipped with a condenser, nitrogen inlet, thermometer, and stirrer was charged with a mixed solution of 81.8 parts ethyl acetate, 90.0 parts butyl acrylate, 5.0 parts methyl acrylate, and 5.0 parts acrylic acid. The air in the vessel was purged with nitrogen gas to remove oxygen, and the internal temperature was raised to 55°C. A solution of 0.15 parts azobisisobutyronitrile (polymerization initiator) in 10 parts ethyl acetate was then added in its entirety. After the addition of the polymerization initiator, the temperature was maintained for 1 hour. Ethyl acetate was then continuously added to the reaction vessel at a rate of 17.3 parts / hour while maintaining the internal temperature at 54-56°C. When the (meth)acrylic resin concentration reached 35% by mass, the ethyl acetate addition was stopped. The temperature was maintained for 6 hours after the start of the ethyl acetate addition. Finally, ethyl acetate was added to adjust the (meth)acrylic resin concentration to 20% by mass, preparing acrylic resin solution 2. The resulting acrylic resin had a weight average molecular weight Mw of 1.6 million and a molecular weight distribution Mw / Mn of 4.5. Mw and Mn were measured using a GPC system with a TSKgel GMH column manufactured by Tosoh Corporation. HR Two "-H(S)" tubes were connected in series, and tetrahydrofuran was used as the eluent. Measurements were performed in terms of standard polystyrene under the following conditions: sample concentration 2 mg / mL, sample introduction volume 100 μL, temperature 40°C, and flow rate 1 mL / min.

[0315] (2) Preparation of Pressure-Sensitive Adhesive Composition 2 To 100 parts of the solid content of the acrylic resin solution 2 obtained in (1) above, 0.15 parts on an active ingredient basis of a crosslinking agent (manufactured by Tosoh Corporation: trade name "Coronate L" (an ethyl acetate solution of a trimethylolpropane adduct of tolylene diisocyanate (solid content concentration 75% by mass)) and 0.2 parts of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.: trade name "KBM-403") were added, and ethyl acetate was further added to make the solid content concentration 13%, thereby obtaining a pressure-sensitive adhesive composition 2.

[0316] (3) Preparation of adhesive layer 2 The pressure-sensitive adhesive composition 2 prepared in (2) above was applied to the release-treated surface of a release-treated polyethylene terephthalate film ("PLR-382190" available from Lintec Corporation) using an applicator so that the dry thickness would be 25 μm, and the applied film was dried at 100°C for 1 minute to produce a pressure-sensitive adhesive layer. The surface of the resulting pressure-sensitive adhesive layer opposite the separator film was then bonded to the release-treated surface of a release-treated polyethylene terephthalate film ("PET-251130" available from Lintec Corporation), to produce pressure-sensitive adhesive layer 2. The storage modulus of pressure-sensitive adhesive layer 2 at 23°C was 0.0255 MPa. The storage modulus was measured by the method described in the Examples section below.

[0317] (Preparation of adhesive layer 3 used as outer adhesive layer) Pressure-sensitive adhesive layer 3 was prepared in the same manner as pressure-sensitive adhesive layer 2, except that the amount of silane coupling agent added was changed to 0.5 parts.

[0318] (Method for measuring phase difference of circular polarizer) The outer adhesive layer of the fabricated circular polarizer (polarizer / second bonding layer / first alignment film / first liquid crystal retardation layer / first bonding layer / second liquid crystal retardation layer / second alignment film / outer adhesive layer) was bonded to glass. The in-plane retardation values ​​for light with wavelengths of 450 nm, 550 nm, and 650 nm were measured using a KOBRA-WR optical analyzer manufactured by Oji Scientific Instruments. The in-plane retardation values ​​for light with wavelengths of 448.2 nm, 498.6 nm, 548.4 nm, 587.3 nm, 628.7 nm, and 748.6 nm were calculated using Cauchy's dispersion formula. The in-plane retardation values ​​were Re(450) = 122 nm, Re(550) = 140 nm, and Re(650) = 144 nm. The relationship between the in-plane retardation values ​​at each wavelength was as follows: Re(450) / Re(550)=0.87 Re(650) / Re(550)=1.03 (In the formula, Re(450) represents the in-plane retardation value for light with a wavelength of 450 nm, Re(550) represents the in-plane retardation value for light with a wavelength of 550 nm, and Re(650) represents the in-plane retardation value for light with a wavelength of 650 nm.)

[0319] Example 2 A circularly polarizing plate was obtained in the same manner as in Example 1, except that the amount of the silicone-based leveling agent added to the first liquid crystal retardation layer-forming composition was 0.07 parts.

[0320] Example 3 A circularly polarizing plate was obtained in the same manner as in Example 1, except that the amount of the silicone-based leveling agent added to the composition for forming the first liquid crystal retardation layer was 0.04 parts.

[0321] Example 4 A circularly polarizing plate was obtained in the same manner as in Example 1, except that the amount of the silicone-based leveling agent added to the second liquid crystal retardation layer-forming composition was 0.08 parts.

[0322] Example 5 A circularly polarizing plate was obtained in the same manner as in Example 1, except that the amount of the silicone leveling agent added to the second liquid crystal retardation layer-forming composition was 0.14 parts.

[0323] Example 6 A circularly polarizing plate was obtained in the same manner as in Example 1, except that 0.12 parts of a fluorine-based leveling agent (Megafac F-556: manufactured by DIC Corporation) was added instead of the silicone-based leveling agent in the composition for forming the first liquid crystal retardation layer.

[0324] Example 7 A circularly polarizing plate was obtained in the same manner as in Example 1, except that 0.12 parts of a fluorine-based leveling agent (Megafac F-556: manufactured by DIC Corporation) was added instead of the silicone-based leveling agent in the composition for forming the second liquid crystal retardation layer.

[0325] Example 8 A circularly polarizing plate was obtained in the same manner as in Example 1, except that 0.25 parts of a fluorine-based leveling agent (Megafac F-554: manufactured by DIC Corporation) was added instead of the silicone-based leveling agent in the ultraviolet-curing adhesive for forming the first bonding layer.

[0326] Example 9 A circularly polarizing plate was obtained in the same manner as in Example 1, except that a triacetyl cellulose film (KC4CZ-TAC manufactured by Konica Minolta, Inc., thickness 40 μm) was used as the second protective layer.

[0327] Example 10 A circularly polarizing plate was obtained in the same manner as in Example 1, except that in the production of the linear polarizer, the dyeing time was adjusted to set the luminosity-corrected single transmittance of the linear polarizer to 41.0%.

[0328] Example 11 A circularly polarizing plate was obtained in the same manner as in Example 1, except that in the production of the linear polarizer, the dyeing time was adjusted to set the luminosity-corrected single transmittance of the linear polarizer to 42.5%.

[0329] Example 12 A circularly polarizing plate was obtained in the same manner as in Example 1, except that no silane coupling agent was added in the production of pressure-sensitive adhesive layer 3 used as the outer pressure-sensitive adhesive.

[0330] Example 13 (Preparation of first laminate)

[0331] [Preparation of composition for forming first alignment film used in Example 13] Water was added to commercially available polyvinyl alcohol (polyvinyl alcohol 1000 fully saponified type, manufactured by Wako Pure Chemical Industries, Ltd.), and the mixture was heated at 100° C. for 1 hour to obtain an oriented polymer composition.

[0332] [Preparation of first liquid crystal retardation layer forming composition used in Example 13] Polymerizable liquid crystal compounds (A3) and (A4) having the structures shown below were prepared. The polymerizable liquid crystal compounds (A3) and (A4) were prepared in the same manner as described in JP-A-2010-244038. Polymerizable liquid crystal compound (A3): [ka] Polymerizable liquid crystal compound (A4): [ka]

[0333] Polymerizable liquid crystal compound (A3) and polymerizable liquid crystal compound (A4) were mixed in a mass ratio of 80:20 to obtain a mixture. 100 parts of the obtained mixture were added with 0.2 parts of a silicone leveling agent "BYK-UV3500" (manufactured by BYK-Chemie, a polyether-modified polydimethylsiloxane having an acrylic functional group), 2.5 parts of a photopolymerization initiator "Omnirad907" (manufactured by IGM Resin BV), and 0.1 parts of an ionic compound. Furthermore, cyclopentanone was added, and the mixture was stirred at a temperature of 80 ° C. for 1 hour to prepare a composition for forming a first liquid crystal retardation layer used in Example 13.

[0334] [Table 3]

[0335] Ionic compounds: [ka]

[0336] [Production of first laminate used in Example 13] A cycloolefin polymer (COP) (ZF14, manufactured by Zeon Corporation) was subjected to corona treatment using a corona treatment device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.), and then the above-mentioned alignment polymer composition was applied thereto. After heating and drying, a first alignment film with a thickness of 100 nm was formed. The surface of the obtained first alignment film was subjected to a rubbing treatment, and the above-mentioned composition for forming the first liquid crystal retardation layer was applied thereon using a bar coater. The obtained coating film was dried at 120°C for 2 minutes, and then exposed to 1000 mJ / cm2 at 80°C under a nitrogen atmosphere using a high-pressure mercury lamp (Uniqure VB-15201BY-A, manufactured by Ushio Inc.). 2 The dried coating was irradiated with ultraviolet light (365 nm standard) to form a first liquid crystal retardation layer in which the polymerizable liquid crystal compound was cured with its optical axis aligned horizontally relative to the substrate surface, thereby obtaining a first laminate used in Example 13, consisting of a first substrate layer / first alignment film / first liquid crystal retardation layer. The thickness of the first liquid crystal retardation layer was measured using a laser microscope and found to be 1.8 μm. Furthermore, the in-plane retardation value at a wavelength of 550 nm, measured using a KOBRA-WR manufactured by Oji Scientific Instruments, was found to be Re(550)=270 nm.

[0337] (Preparation of second laminate) [Preparation of second liquid crystal retardation layer forming composition used in Example 13] A second liquid crystal retardation layer forming composition used in Example 13 was prepared in the same manner as in Example 1 except that the amount of the silicone leveling agent added was 0.15 parts.

[0338] [Production of second laminate used in Example 13] The above-mentioned alignment polymer composition was applied to a triacetyl cellulose film (TAC) (KC4UY, manufactured by Konica Minolta, Inc.), and after heating and drying, a second alignment film with a thickness of 100 nm was formed. The surface of the obtained second alignment film was subjected to a rubbing treatment, and the above-mentioned composition for forming a second liquid crystal retardation layer was applied thereon using a bar coater. The obtained coating film was dried at 100°C for 1 minute and then cooled to room temperature to obtain a dried film. Next, using a high-pressure mercury lamp (Uniqure VB-15201BY-A, manufactured by Ushio Inc.), an exposure dose of 1000 mJ / cm was applied under a nitrogen atmosphere. 2 The dried film was irradiated with ultraviolet light (365 nm standard) to form a second liquid crystal retardation layer in which the polymerizable liquid crystal compound was cured in a state of being aligned horizontally relative to the in-plane of the substrate, thereby obtaining a second laminate used in Example 13 consisting of a second substrate layer / second alignment film / second liquid crystal retardation layer. The second liquid crystal retardation layer had a film thickness of 1.0 μm and an in-plane retardation value at a wavelength of 550 nm of Re(550)=140 nm.

[0339] (Preparation of circular polarizing plate) A circularly polarizing plate was obtained in the same manner as in Example 1, except that the first laminate and the second laminate were changed to the first laminate and the second laminate described above.

[0340] Example 14 A circularly polarizing plate was obtained in the same manner as in Example 1, except that no silicone-based leveling agent was added to the ultraviolet-curable adhesive for forming the first laminating layer.

[0341] Example 15 A circularly polarizing plate was obtained in the same manner as in Example 6, except that the silicone-based leveling agent was not added to the ultraviolet-curable adhesive for forming the first laminating layer.

[0342] Example 16 A circularly polarizing plate was obtained in the same manner as in Example 7, except that no silicone-based leveling agent was added to the ultraviolet-curable adhesive for forming the first laminating layer.

[0343] (Comparative Example 1) In the composition for forming the first liquid crystal retardation layer, 0.1 parts of a fluorine-based leveling agent (Megafac F-556: manufactured by DIC Corporation) was added instead of the silicone-based leveling agent, and in the composition for forming the second liquid crystal retardation layer, no silicone-based leveling agent was added, and in the ultraviolet-curable adhesive for forming the first bonding layer, no silicone-based leveling agent was added. A circularly polarizing plate was obtained in the same manner as in Example 1, except that.

[0344] (Comparative Example 2) A circularly polarizing plate was obtained in the same manner as in Example 1, except that the above-mentioned pressure-sensitive adhesive layer 2 was used instead of the pressure-sensitive adhesive layer 1 as the second attaching layer.

[0345] (Comparative Example 3) A circularly polarizing plate was obtained in the same manner as in Comparative Example 1, except that a silicone-based leveling agent was added to the ultraviolet-curable adhesive for forming the first laminating layer.

[0346] (Evaluation of circular polarizers) (Adhesion evaluation of circular polarizers (crosshatch test)) The resulting circular polarizing plate was evaluated for durability against external forces using a crosshatch test (JIS D0202-1988 "checkerboard adhesion test") in accordance with JIS. The circular polarizing plate was attached to glass via its outer adhesive. One hundred 1 mm square checkerboard patterns were cut with a utility knife onto the linear polarizing plate side opposite the glass surface, and adhesive tape (25 mm wide, manufactured by Nichiban) was then completely adhered to the checkerboard. The adhesive tape was then peeled off at a 90° angle relative to the surface. The number of checkerboard patterns that remained unpeeled out of the 100 checkerboard patterns was used to evaluate durability against external forces.

[0347] Evaluation criteria: A: 97 or above B: 90 or more and less than 97 C: 75 or more and less than 90 D: Under 75

[0348] (Adhesion of circular polarizers in bending) The obtained circular polarizing plate was cut into a size of 10 mm x 100 mm and subjected to a mandrel test in accordance with JIS K 5600-5-1:1999. In the mandrel test, the plate was uniformly bent around a cylindrical mandrel with a bending radius of 1 mm at room temperature (25°C). Immediately after (1 to 2 seconds), the bent optical film was returned to its flat state, and peeling between layers in the circular polarizing plate was confirmed.

[0349] Evaluation criteria: ◯: No lifting or peeling between layers occurs in the circular polarizing plate. △: Lifting or peeling occurred between layers in the circular polarizing plate.

[0350] (Evaluation of coating unevenness of optical laminate) (1: Evaluation of coating unevenness that occurs during lamination layer formation) The coating properties of the UV-curable adhesive for forming the lamination layer on the surfaces of the first liquid crystal retardation layer and the second liquid crystal retardation layer were evaluated. The UV-curable adhesive was applied to the surface of the first liquid crystal retardation layer of the first laminate used in each Example and Comparative Example, and to the surface of the second liquid crystal retardation layer of the second laminate used in each Example and Comparative Example, using a bar coater, and allowed to stand for 300 seconds. After 300 seconds, the state of the adhesive on the surfaces of the first liquid crystal retardation layer and the second liquid crystal retardation layer was visually confirmed, and the coating state of the adhesive was evaluated using the following evaluation method.

[0351] Evaluation criteria: A: The adhesive is maintained in a state where it is uniformly applied to the surface of the first or second liquid crystal retardation layer. B: The adhesive partially aggregates on the surface of the first or second liquid crystal retardation layer, but remains on the entire surface. C: The adhesive aggregates on the surface of the first or second liquid crystal retardation layer, and there are areas where the adhesive is not applied.

[0352] (2: Evaluation of coating unevenness that occurs when forming a liquid crystal retardation layer) The coatability of the first liquid crystal retardation layer-forming composition and the second liquid crystal retardation layer-forming composition on the surface of the substrate layer was evaluated. The first liquid crystal retardation layer-forming composition used in each Example and Comparative Example was applied to the first alignment film of the first substrate, and the second liquid crystal retardation layer-forming composition used in each Example and Comparative Example was applied to the second alignment film of the second substrate using a bar coater, and then allowed to stand for 300 seconds. After 300 seconds, the state of the liquid crystal retardation layer-forming composition on the alignment film was visually confirmed, and the coating state of the liquid crystal retardation layer-forming composition was evaluated using the following evaluation method. evaluation: A: The liquid crystal retardation layer forming composition is maintained in a state where it is uniformly applied to the surface of the first or second alignment film. B: The liquid crystal retardation layer forming composition is partially aggregated on the surface of the first or second alignment film, but remains on the entire surface. C: The composition for forming a liquid crystal retardation layer aggregates on the surface of the first or second alignment film, and there are regions where the composition for forming a liquid crystal retardation layer is not applied.

[0353] [Analysis of Si atoms and F atoms in the liquid crystal retardation layer and the first bonding layer] The surfaces of the first and second laminates prepared opposite the substrate (the surfaces on the bonding layer side) were each subjected to corona treatment (800 W, 10 m / min, bar width 700 mm, 1 pass), and then the constituent elements of each surface were analyzed by XPS (K-Alpha+ manufactured by Thermo Fisher Scientific) under the conditions listed in Table 1 below.

[0354] The atomic concentrations of Si and F atoms were calculated as the atomic ratio. The measured elements were C, F, N, O, and Si, and the ratio of the number of Si atoms to the total number of these elements was calculated.

[0355] Next, elemental information was confirmed by XPS while etching was performed from the surface opposite the substrate using an Ar gas cluster ion beam under the etching conditions shown in Table 3 below, and the etching time required to reach the interface on the substrate side from the surface opposite the substrate was confirmed. After calculating the etching rate (nm / sec) from the etching time and the film thicknesses of the first liquid crystal retardation layer and the second liquid crystal retardation layer, etching was performed from the surface opposite the substrate to a point 10 nm away from the stacking direction of the laminate by adjusting the etching treatment time, and elemental analysis information at a point 10 nm away from the surface opposite the substrate in the stacking direction of the laminate was extracted. Although not shown in the table, in all Examples, the Si atomic concentration at a point 10 nm deep from the surface of the first adhesive layer side of the first liquid crystal retardation layer in the stacking direction of the laminate, and the Si atomic concentration at a point 10 nm deep from the surface of the first adhesive layer side of the second liquid crystal retardation layer in the stacking direction of the laminate, were less than 0.5%.

[0356] [Table 4]

[0357] (Method and definition of the luminous efficiency corrected transmittance Ty of a polarizer) The MD transmittance and TD transmittance of the linear polarizer were measured in the wavelength range of 380 to 780 nm using a spectrophotometer equipped with an integrating sphere ("V7100" manufactured by JASCO Corporation), and the transmittance was calculated using the following formula: Single transmittance (%) = (MD + TD) / 2 The single transmittance at each wavelength was calculated based on the above.

[0358] "MD transmittance" refers to the transmittance when the direction of polarized light exiting the Glan-Thompson prism is parallel to the transmission axis of the linearly polarizing layer, and is represented as "MD" in the above formula. "TD transmittance" refers to the transmittance when the direction of polarized light exiting the Glan-Thompson prism is perpendicular to the transmission axis of the linearly polarizing layer, and is represented as "TD" in the above formula. The obtained single transmittance was subjected to luminosity correction using a 2-degree observer (illuminant C) in accordance with JIS Z 8701:1999 "Method of displaying color - XYZ color system and X10Y10Z10 color system" to determine the luminosity-corrected single transmittance.

[0359] (peel test) The second liquid crystal retardation layer side of the second laminate was attached to a glass substrate via an adhesive, and the PET film, which was the second base layer, was peeled off to expose the second alignment film. Next, the separate film on one side of the outer adhesive layer was peeled off and attached to a PET film with a thickness of 100 μm, the same as the first base layer. The resulting PET film with the outer adhesive layer was cut into a width of 25 mm and attached to the second alignment film of the second laminate obtained above. A 180° peel test was performed using a tensile tester at a pulling rate of 0.3 m / min under an environment of 23°C, and the peel strength [N / 25 mm] when peeling the alignment film of the second laminate from the outer adhesive was measured.

[0360] (Method for measuring storage modulus of second adhesive layer) The storage modulus of the pressure-sensitive adhesive layer was measured using a viscoelasticity measuring device (MCR-301, Anton Paar). The same pressure-sensitive adhesive layer as used in the Examples and Comparative Examples was cut to a width of 30 mm and a length of 30 mm, the release film was peeled off, and multiple layers were stacked to a thickness of 200 μm. The layers were then bonded to a measurement stage and attached to a measurement chip (PP25, Anton Paar). Measurements were then carried out in a temperature range of −20° C. to 100° C. under conditions of a frequency of 1.0 Hz, a deformation of 1%, a normal force of 1 N, and a heating rate of 5° C. / min to obtain the storage modulus [MPa] at a temperature of 23° C.

[0361] (Appearance evaluation) The circular polarizing plate was attached to a reflector (mirror-finished aluminum plate) via the outer adhesive layer. A three-wavelength fluorescent lamp was turned on above the surface facing the linear polarizing plate, and the light was reflected by the surface. In this state, the circular polarizing plate was visually observed from a distance of 30 cm. The appearance at this time was subjected to a sensory evaluation. The evaluation criteria were as follows:

[0362] Evaluation criteria: A: The entire circular polarizing plate appears uniformly dark, and no irregularities in phase difference or other areas are visible. A-: The appearance of the circular polarizing plate is almost uniform, and although there may be very slight unevenness in retardation or coating, it is difficult to see. B: There are slight irregularities in retardation or coating on the circular polarizer, but these irregularities are not noticeable and have almost no effect on the function of the circular polarizer. C: The circular polarizing plate has obvious unevenness in retardation or coating, and these unevennesses are visible, but the basic function of the circular polarizing plate is not impaired. D: Retardation unevenness and coating unevenness are clearly visible on the circular polarizing plate, and there are significant problems with appearance, such as coloring. The conditions and evaluation results are shown in Tables 5, 6, and 7.

[0363] [Table 5]

[0364] [Table 6]

[0365] [Table 7] [Explanation of symbols]

[0366] 10...first base material layer, 30...first liquid crystal retardation layer, 40...first bonding layer, 50...second liquid crystal retardation layer, 70...second base material layer, 100...optical laminate, 150...second bonding layer, 180...first protective layer, 190...second protective layer, 200...polarizing plate, 300...retardation layer laminate, 400...polarizing laminate (circular polarizing plate).

Claims

1. A polarizing laminate including a linear polarizer, a second bonding layer, a first liquid crystal retardation layer, a first bonding layer, and a second liquid crystal retardation layer in this order, at least one of or both of the first liquid crystal retardation layer and the second liquid crystal retardation layer contains Si atoms, the atomic concentration of Si atoms on the surface of the liquid crystal retardation layer on the first bonding layer side in at least one of the liquid crystal retardation layers containing Si atoms is higher than the atomic concentration of Si atoms at a point 10 nm away from the surface of the liquid crystal retardation layer on the first bonding layer side in the lamination direction of the polarizing laminate, A polarizing laminate, wherein the second bonding layer has a storage modulus of 0.03 MPa or more at 23°C and 1 Hz.

2. 2. The polarizing laminate according to claim 1, wherein the atomic concentration of Si atoms on the surface of the first bonding layer side in at least one of the liquid crystal retardation layers containing Si atoms is 0.5 at % or more and 10 at % or less.

3. The polarizing laminate according to claim 1 or 2, wherein the atomic concentration of Si atoms at a point 10 nm from the surface on the first bonding layer side in the stacking direction of the polarizing laminate in at least one of the liquid crystal retardation layers containing Si atoms is less than 0.5 at%.

4. The polarizing laminate according to claim 1 , wherein both the first liquid crystal retardation layer and the second liquid crystal retardation layer contain Si atoms.

5. The polarizing laminate according to claim 1 or 2, wherein the first bonding layer contains F atoms and / or Si atoms.

6. The polarizing laminate according to claim 1 , wherein the first bonding layer contains Si atoms.

7. The polarizing laminate according to claim 1 or 2, which satisfies the relationships of the following formulas (1) and (2): 100≦Re(550)≦180 (1) Re(450) / Re(550)≦1.00 (2) [In formula (1) and formula (2), Re(450) represents the in-plane retardation value (nm) of the polarizing laminate for light having a wavelength of 450 nm; Re(550) represents the in-plane retardation value (nm) of the polarizing laminate for light with a wavelength of 550 nm.]

8. The polarizing laminate according to claim 1 or 2, further comprising a protective layer between the linear polarizer and the second attaching layer, the protective layer having a thickness of 30 μm or less.

9. 3. The polarizing laminate according to claim 1, wherein the linear polarizer has a luminous transmittance Ty of 41.5% or more.

10. The polarizing laminate according to claim 1 or 2, further comprising an outer adhesive layer on the opposite side of the second liquid crystal retardation layer from the first attaching layer, the outer adhesive layer containing a silane compound.

11. An image display device comprising the polarizing laminate according to claim 1 or 2 and an image display cell.

Images