Optical laminate, image display device

Abstract

To prevent an aging change of in-plane phase difference characteristics, and to prevent a corrosion of a metal member equipped in an image display panel to be bonded.SOLUTION: An optical laminate 1 includes a first protective film 21, a polarizer 22, a second protective film 23, a phase element 4, and an adhesive layer 5 in this order. A moisture vapor permeability of the second protective film 23 is 1200 g / (m2 day) or less. The adhesive layer 5 includes an anti-static agent. The anti-static agent includes an ionic compound including an organic cation and an anion expressed by a formula (1) below: (CnF2n+1SO2)2 N- ...(1), (in the formula, n is an integer of 0 to 5).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical laminate and an image display device including the same. [Background technology]

[0002] In image display devices such as organic EL display devices, it is known that a circular polarizing plate is used to improve anti-reflection performance in order to suppress a decrease in visibility due to reflection of external light (for example, Patent Document 1). A circular polarizing plate is an optical laminate including a polarizer and a retarder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 160033 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional circular polarizing plates have a problem of changes in in-plane retardation characteristics, especially with continued use at high temperatures. In-plane retardation characteristics refer to the retardation value at each wavelength and wavelength dispersion, and changes in these characteristics result in changes in the reflected hue. Furthermore, when a circular polarizing plate is attached to an image display panel, corrosion of the metal components of the image display panel has been observed for some reason. This problem is particularly likely to become more pronounced when the adhesive on the panel attachment surface contains an antistatic agent. Therefore, an object of the present invention is to provide an optical laminate including a polarizer and a retarder, which is capable of suppressing changes in in-plane retardation characteristics over time and suppressing corrosion of the metal components of the attached image display panel. Another object of the present invention is to provide an image display device including the optical laminate. [Means for solving the problem]

[0005] The inventors have conducted studies and found that the cause of changes in the retardation characteristics of conventional circular polarizing plates is thought to be the migration of iodine contained in the polarizer or the antistatic agent contained in the adhesive layer to the retarder. Furthermore, the inventors have conducted studies and found that the cause of corrosion of metal members of an image display panel when a conventional circular polarizing plate is attached to the image display panel is thought to be the corrosion of the metal members caused by iodine contained in the polarizer or the antistatic agent contained in the adhesive layer. Based on these findings, the inventors have conducted studies and completed the invention described below.

[0006] The present invention relates to an optical laminate comprising a first protective film, a polarizer, a second protective film, a retarder, and a pressure-sensitive adhesive layer in this order, wherein the moisture permeability of the second protective film is 1200 g / (m 2 The pressure-sensitive adhesive layer contains an antistatic agent, and the antistatic agent contains an ionic compound composed of an organic cation and an anion represented by the following formula (1): (C n F 2n+1 SO2)2N - …(1) (In the formula, n is an integer of 0 to 5.)

[0007] This optical laminate can appropriately suppress the migration of iodine contained in the polarizer and the antistatic agent contained in the pressure-sensitive adhesive layer across layers within the optical laminate.

[0008] The optical stack may have one or more of the following characteristics: The water vapor permeability coefficient of the retarder is 100 or less. The retarder includes a first retardation layer, a pressure-sensitive adhesive layer, and a second retardation layer, and functions as a λ / 4 plate across the entire visible light range. The adhesive layer is made of an active energy ray curing adhesive. The second protective film is made of a cyclic polyolefin resin. The thickness of the second protective film is 1 to 10 μm. The moisture permeability of the first protective film is 100g / (m 2·day) or more. · Ionic compounds contain organic cations that contain nitrogen atoms.

[0009] The present invention also provides an image display device comprising the optical laminate and an image display panel to which the optical laminate is attached. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an optical laminate including a polarizer and a retarder, which can suppress changes in in-plane retardation characteristics over time and can suppress corrosion of metal members included in an image display panel to which the optical laminate is attached. Furthermore, according to the present invention, it is possible to provide an image display device including the optical laminate. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view of an optical laminate according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0013] <Optical laminate> (1) Overview As shown in FIG. 1 , the optical laminate 1 of this embodiment is a circular polarizer comprising a linear polarizer 2, a retarder 4, and a pressure-sensitive adhesive layer 5 in this order. The term "circular polarizer" includes an elliptically polarizer. The optical laminate 1 can be used as an anti-reflection film in an image display device such as an organic electroluminescence (organic EL) display device. The linear polarizer 2 and the retarder 4 are laminated together by a linear polarizer-retarder pressure-sensitive adhesive layer 3.

[0014] The linear polarizer 2 includes a first protective film 21, a polarizer 22, and a second protective film 23, in this order. A linear polarizer internal adhesive layer (not shown) is laminated between the first protective film 21 and the polarizer 22, and between the polarizer 22 and the second protective film 23. The linear polarizer internal adhesive layer is optional, and the first protective film 21 and the polarizer 22, and the polarizer 22 and the second protective film 23 may be in direct contact with each other.

[0015] Each component will be described in detail below.

[0016] (2) Polarizer The polarizer 22 is an optical film (linear polarizer) that transmits linearly polarized light having a vibration plane perpendicular to the absorption axis when unpolarized light is incident on the polarizer 22. Specifically, the polarizer 22 is a polyvinyl alcohol-based resin film (hereinafter also referred to as a "PVA-based film") in which a dichroic dye is adsorbed and oriented.

[0017] The polyvinyl alcohol resin (hereinafter also referred to as "PVA resin") constituting the PVA film can be produced by saponifying a polyvinyl acetate resin. The polyvinyl acetate resin can be a copolymer of vinyl acetate and another monomer copolymerizable with vinyl acetate, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth)acrylamides having an ammonium group. In this specification, "(meth)acrylic" means either acrylic or methacrylic. The "(meth)" in (meth)acrylate, etc., has the same meaning.

[0018] The saponification degree of the PVA-based resin is usually about 85 to 100 mol %, preferably 98 mol % or more. The PVA-based resin may be modified; for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may also be used. The average polymerization degree of the PVA-based resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000. The average polymerization degree of the PVA-based resin can be determined in accordance with JIS K 6726 (1994). If the average polymerization degree is less than 1,000, it is difficult to obtain desirable polarizing performance, and if it exceeds 10,000, film processability may be poor.

[0019] A polarizer is usually produced through the steps of uniaxially stretching a PVA-based film, dyeing the PVA-based film with a dichroic dye to adsorb the dichroic dye, treating the PVA-based film with the adsorbed dichroic dye with a boric acid aqueous solution to crosslink the film, and washing the film with water after the crosslinking treatment with the boric acid aqueous solution (hereinafter also referred to as boric acid treatment).

[0020] The uniaxial stretching of a PVA-based 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. Furthermore, uniaxial stretching may be performed by dry stretching in the air, or by wet stretching in which the PVA-based film is swollen using a solvent such as water. The stretching ratio is usually about 3 to 8 times.

[0021] Dyeing of a PVA-based film with a dichroic dye can be carried out, for example, by immersing the PVA-based film in an aqueous solution containing the dichroic dye. Specific examples of the dichroic dye include iodine and dichroic organic dyes. It is preferable to immerse the PVA-based film in water to swell it before dyeing.

[0022] When iodine is used as the dichroic dye, a dyeing method is usually employed in which a PVA-based film is immersed in an aqueous solution containing iodine and potassium iodide. The iodine content in this aqueous solution is usually about 0.01 to 1 part by mass per 100 parts by mass of water, and the potassium iodide content is usually about 0.5 to 20 parts by mass per 100 parts by mass of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40°C. The immersion time in this aqueous solution (dyeing time) is usually about 20 to 1,800 seconds.

[0023] On the other hand, when a dichroic organic dye is used as the dichroic pigment, a method of dyeing a PVA-based 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, and 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.

[0024] The boric acid treatment after dyeing with a dichroic dye can be carried out by immersing the dyed PVA 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.

[0025] The PVA 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 PVA 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.

[0026] 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.

[0027] In this manner, a polarizer in which a dichroic dye is adsorbed and oriented on a PVA film can be produced.

[0028] The luminosity-corrected polarization degree Py of the polarizer is usually 95% or more, preferably 97% or more, more preferably 98% or more, even more preferably 98.7% or more, still more preferably 99.0% or more, particularly preferably 99.4% or more, and may be 99.9% or more. The luminosity-corrected polarization degree Py of the polarizer may be 99.99% or less. The luminosity-corrected polarization degree Py can be calculated by using an integrating sphere spectrophotometer ("V7100" manufactured by JASCO Corporation) to perform luminosity correction on the obtained polarization degree using a 2-degree visual field (C light source) according to "JIS Z 8701."

[0029] Increasing the luminosity-corrected polarization degree Py of the polarizer is advantageous in terms of improving the function of the optical laminate as an antireflection film and the durability of the optical laminate. If the luminosity-corrected polarization degree Py of the polarizer is less than 95%, the polarizer may not function as an antireflection film.

[0030] The thickness of the polarizer is 15 μm or less, preferably 13 μm or less, and more preferably 10 μm or less. When the thickness of the polarizer is within this range, it is advantageous for thinning the optical laminate and can more effectively suppress the amount of change in retardation. The thickness of the polarizer is usually 2 μm or more, preferably 3 μm or more, and may be, for example, 5 μm or more.

[0031] (3) First protective film The first protective film 21 has a function of protecting the surface of the polarizer 22. The first protective film 21 may be laminated in direct contact with the surface of the polarizer 22, or may be laminated via an internal pressure-sensitive adhesive layer in the linear polarizer. The first protective film 21 may be subjected to a surface treatment (for example, corona treatment) to improve adhesion to the polarizer 22, and may have a thin layer such as a primer layer (also referred to as an easy-adhesion layer) formed thereon.

[0032] The thickness T1 of the first protective film is usually 60 μm or less, and from the viewpoint of suppressing curling of the entire polarizing plate under a durable environment, it is preferably 50 μm or less, more preferably 40 μm or less, and is preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more.

[0033] The first protective film may be, for example, a resin film that is excellent in transparency, mechanical strength, thermal stability, moisture blocking properties, isotropy, stretchability, etc. The resin film may be a thermoplastic resin film. Specific examples of such thermoplastic resins include: cellulose ester resins such as triacetyl cellulose; Polyester resins such as polyethylene terephthalate and polyethylene naphthalate; Polyethersulfone resin; Polysulfone resin; Polycarbonate-based resins; Polyamide resins such as nylon and aromatic polyamides; Polyimide resins; Linear polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; Cyclic polyolefin resins having cyclo and norbornene structures (also called norbornene resins); (Meth)acrylic resins such as polymethyl methacrylate; Polyarylate resins; Polystyrene resins; Polyvinyl alcohol resin, and mixtures thereof. The protective film made of the above thermoplastic resin may be commercially available.

[0034] Examples of linear polyolefin resins include linear olefin homopolymers such as polyethylene resins (polyethylene resins which are homopolymers of ethylene and copolymers mainly composed of ethylene) and polypropylene resins (polypropylene resins which are homopolymers of propylene and copolymers mainly composed of propylene), as well as copolymers made of two or more types of linear olefins.

[0035] Cyclic polyolefin resin is a general term for resins polymerized using cyclic olefins as polymerization units, and examples thereof include resins described in JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, etc. Specific examples of cyclic polyolefin resins include ring-opening (co)polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers (typically random copolymers) of cyclic olefins with chain olefins such as ethylene and propylene, graft polymers modified with unsaturated carboxylic acids or their derivatives, and hydrogenated products thereof. Among these, norbornene resins using norbornene monomers such as norbornene or polycyclic norbornene monomers as the cyclic olefin are preferred.

[0036] Polyester resins are resins having ester bonds in the main chain, and are generally polycondensates of polycarboxylic acids or their derivatives with polyhydric alcohols. Examples of polycarboxylic acids or their derivatives include dicarboxylic acids or their derivatives, such as terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalenedicarboxylate. Examples of polyhydric alcohols include dihydric diols, such as ethylene glycol, propanediol, butanediol, neopentyl glycol, and cyclohexanedimethanol. A typical example of a polyester resin is polyethylene terephthalate, which is a polycondensate of terephthalic acid and ethylene glycol.

[0037] Cellulose ester resins are esters of cellulose and fatty acids. Specific examples of cellulose ester resins include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. Other examples include copolymers having multiple types of polymerization units constituting these cellulose ester resins, and resins in which some of the hydroxyl groups have been modified with other substituents. Among these, cellulose triacetate (triacetyl cellulose) is particularly preferred.

[0038] (Meth)acrylic resins are resins whose main constituent monomer is a compound having a (meth)acryloyl group. Specific examples of (meth)acrylic resins include poly(meth)acrylic esters such as polymethyl methacrylate; methyl methacrylate-(meth)acrylic acid copolymers; methyl methacrylate-(meth)acrylic ester copolymers; methyl methacrylate-acrylic ester-(meth)acrylic acid copolymers; methyl (meth)acrylate-styrene copolymers (such as MS resins); and copolymers of methyl methacrylate and compounds having alicyclic hydrocarbon groups (such as methyl methacrylate-cyclohexyl methacrylate copolymers and methyl methacrylate-norbornyl (meth)acrylate copolymers). Preferably, polymers whose main component is a poly(meth)acrylic acid C1-C6 alkyl ester, such as polymethyl (meth)acrylate, are used. More preferably, methyl methacrylate resins whose main component is methyl methacrylate (50 to 100% by mass, preferably 70 to 100% by mass) are used.

[0039] Polycarbonate-based resins are polymers in which monomer units are bonded via carbonate groups. The polycarbonate-based resins may be modified polycarbonates, which are resins in which the polymer skeleton is modified, or copolymer polycarbonates.

[0040] The first protective film may be a film containing the thermoplastic resin described above that has been stretched. Examples of stretching methods 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 simultaneously, or sequential biaxial stretching, in which the film is stretched in a predetermined direction and then stretched in the other direction. The stretching process may be performed, for example, by stretching the unstretched film in the longitudinal direction (MD) using two or more pairs of nip rolls with a high peripheral speed at the exit 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 and wavelength dispersion values 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 first protective 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, a coating layer (surface treatment layer) can be provided on the outer surface of the first protective film to impart desired surface optical properties or other characteristics. 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 first protective film.

[0043] The hard coat layer has the function of increasing the surface hardness of the first protective 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 paints - Part 5: Mechanical properties of coating films - Section 4: Scratch hardness (pencil method)" (measurement is performed by placing a protective film having a hard coat layer on a glass plate).

[0044] The material for forming the hard coat layer is 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 the protective film and excellent productivity.

[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, for example, 1) forming a coating film containing fine particles on a protective film and creating texture based on the fine particles, or 2) forming a coating film, which may or may not contain fine particles, on a protective 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 weakens the reflection of external light from the surface of the protective film for those observing the protective 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 having a high refractive index and a low-refractive index layer having a low refractive index, or by using the method and materials described in JP 2021-6929 A. By adjusting the refractive index and the thickness of each layer, the reflected light from each layer can be weakened by the other, resulting in excellent anti-reflection properties.

[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 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 protective 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 electrical conductivity to the surface of the first protective film and suppressing the effects of static electricity. For example, the antistatic layer can be formed by applying a resin composition containing a conductive substance (antistatic agent) onto the first protective film. 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 optical laminate is applied to an image display device, diffusion of the dichroic dye such as iodine in the polarizer 22 may cause corrosion of metal members (electrodes, etc.) present near the optical laminate in the image display device. This is because the dichroic dye such as iodine migrates to the metal members due to the diffusion. To suppress corrosion of the metal members, it is preferable to suppress the amount of dichroic dye migrating to the metal members.

[0056] The moisture permeability of the first protective film is 100g / (m 2·day) or more. This moisture permeability is preferably 100 g / (m 2 ·day) or more 2000g / (m 2 ·day) or less, and 200g / (m 2 ·day) or more 1000g / (m 2 ·day) or less is more preferable, and 300g / (m 2 ·day) or more 500g / (m 2 ·day) or less is even more preferable. When iodine contained in the polarizer migrates between layers of the optical laminate 1, if the moisture permeability of the first protective film 21 is too low, the migration of iodine is too suppressed and tends to be biased toward the opposite direction (toward the retarder side). Furthermore, if the moisture permeability of the first protective film 21 is too high, the polarizer tends to be prone to moist heat degradation. Therefore, it is preferable that the moisture permeability of the first protective film is appropriately high so that when iodine migrates toward the first protective film 21 side, the iodine passes through the first protective film 21 and diffuses out of the optical laminate 1.

[0057] (4) Second protective film The second protective film 23 has a function of protecting the surface of the polarizer 22. The second protective film 23 may be laminated in direct contact with the surface of the polarizer 22, or may be laminated via an internal pressure-sensitive adhesive layer in the linear polarizer. The second protective film 23 may be subjected to a surface treatment (e.g., corona treatment) to improve adhesion to the polarizer 22, and may have a thin layer such as a primer layer (also referred to as an easy-adhesion layer) formed thereon.

[0058] The moisture permeability of the second protective film 23 is 1200 g / (m 2 ·day) or less. This moisture permeability is 0.1g / (m 2 ·day) or more 800g / (m 2 ·day) or less, and 0.5g / (m 2 ·day) or more 500g / (m 2 ·day) or less is more preferable, and 1g / (m 2 ·day) or more 100g / (m 2 ·day) or less, and2 ·day) or more than 50g / (m 2 ·day) or less. When the moisture permeability of the second protective film 23 is within this range, it is possible to sufficiently prevent iodine from migrating to the phase shifter side. In addition, it is preferable that the moisture permeability of the second protective film 23 is 10 g / (m 2 ·day) or more is also preferable from the viewpoint of Δα, which will be described later. The moisture permeability of the second protective film 23 can be measured according to the description in the [Examples] section.

[0059] The thickness T2 of the second protective film is, for example, 0.1 to 60 μm, preferably 0.2 to 30 μm. It is advantageous for this embodiment that the thickness T2 of the second protective film is appropriately thin. That is, when the antistatic agent contained in the pressure-sensitive adhesive layer described below migrates between layers of the optical laminate 1, if the thickness of the second protective film 23 is too large, the migration of the antistatic agent is too suppressed, and the migration tends to be biased toward the opposite direction (toward the image display panel). Therefore, from the viewpoint of suppressing corrosion of metal members, the thickness T2 of the second protective film is preferably 1 to 10 μm, more preferably 2 to 8 μm, and even more preferably 3 to 5 μm.

[0060] The second protective film may be, for example, a resin film that is excellent in transparency, mechanical strength, thermal stability, moisture blocking properties, isotropy, stretchability, etc. The resin film may be a thermoplastic resin film. Specific examples of such thermoplastic resins are the same as those described for the first protective film. Protective films made of thermoplastic resins may be commercially available.

[0061] The thermoplastic resins constituting the thermoplastic resin film used as the second protective film and the thermoplastic resin layer described below are preferably cyclic polyolefin-based resins, polyester-based resins, polycarbonate-based resins, (meth)acrylic resins, and polystyrene-based resins, more preferably cyclic polyolefin-based resins, (meth)acrylic resins, and polystyrene-based resins, even more preferably cyclic polyolefin-based resins and (meth)acrylic resins, and even more preferably cyclic polyolefin-based resins.

[0062] The thermoplastic resin film used as the second protective film may be a film existing alone. In this case, the thermoplastic resin film is laminated on the polarizer 22, if necessary, via a pressure-sensitive adhesive layer in the linear polarizer. Alternatively, the second protective film may be a thermoplastic resin layer. For example, a composition containing a thermoplastic resin is applied to a supporting substrate, and if necessary, dried to obtain a thermoplastic resin layer with a supporting substrate. This is then attached to the polarizer 22, if necessary, via a pressure-sensitive adhesive layer in the linear polarizer. Thereafter, the supporting substrate is peeled off and removed, thereby laminating a thermoplastic resin layer as the second protective film on the polarizer 22 (first method).

[0063] When the second protective film is a thermoplastic resin layer, it is also possible to form a thermoplastic resin layer by applying the composition directly to the surface of the polarizer 22 and drying it as necessary (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.

[0064] The second protective film 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 the polarizer 22 via a pressure-sensitive adhesive layer within the linear polarizing plate, if necessary. The support substrate is then peeled off and removed, thereby laminating the cured resin layer as the second protective film on the polarizer 22.

[0065] From the viewpoint of moisture permeability or suppressing a change in retardation characteristics, the second protective film is preferably a thermoplastic resin film or layer made of a cyclic polyolefin resin, a thermoplastic resin film or layer made of a (meth)acrylic resin, a cured resin layer containing a cured product of a (meth)acrylic resin, or a thermoplastic resin film or layer made of a polystyrene resin. Taking into consideration the need to further suppress migration of the dichroic dye in the polarizer 22 to the metal member, the second protective film is more preferably a thermoplastic resin film or layer made of a cyclic polyolefin resin, or a thermoplastic resin film or layer made of a polystyrene resin.

[0066] The second protective film may contain any suitable additive depending on the purpose, and specific examples of the additive are the same as those described for the first protective film.

[0067] The second protective film preferably has no retardation property or a small retardation value. Specifically, the in-plane retardation value of the second protective film at a wavelength of 550 nm is preferably 10 nm or less. The in-plane retardation value is 0 nm or more. Furthermore, the thickness direction retardation value of the second protective film at a wavelength of 550 nm is preferably -10 nm to +10 nm.

[0068] (5) Phaser The retarder 4 is an optical element that exhibits retardation in the in-plane or thickness direction, and preferably includes a retardation film. The retardation film is a film that exhibits retardation in the in-plane or thickness direction, and is a layer (cured layer) made of a polymer of a polymerizable liquid crystal compound, or a combination of such a layer and an alignment film. The retardation film includes, for example, a cured layer of a retardation film-forming composition that contains a polymerizable liquid crystal compound.

[0069] When the retarder 4 includes a retardation film, the dichroic dye migrates to the metal member, which makes the metal member more susceptible to corrosion, but according to the present invention, the corrosion can be effectively suppressed even when the retarder 4 includes a retardation film. Furthermore, when the retarder 4 includes a retardation film, this is advantageous for reducing the thickness of the optical laminate, and the fact that the retarder 4 includes a retardation film is preferable in that the wavelength dispersion characteristics can be arbitrarily designed.

[0070] The retarder 4 in the optical laminate 1 of this embodiment has two types of retardation films (hereinafter also referred to as "retardation layers"). That is, a first retardation layer 41 and a second retardation layer 43 are laminated with an inner retarder pressure-sensitive adhesive layer 42. In this specification, the retardation films included in the retarder 4 may be referred to as the "first retardation layer" and the "second retardation layer" in order of proximity to the linear polarizer 2. Possible configurations of the retarder 4 will be described below.

[0071] (5-1) Retardation film A retardation film is usually formed by applying a retardation film-forming composition onto an alignment film formed on a substrate and polymerizing the polymerizable liquid crystal compound contained in the retardation film-forming composition. A retardation film is usually a film in which the polymerizable liquid crystal compound is cured in an aligned state. To generate a retardation in the viewing plane, the film must be a cured film in which the polymerizable group is polymerized while the polymerizable liquid crystal compound is aligned horizontally relative to the substrate surface. In this case, if the polymerizable liquid crystal compound is a rod-shaped liquid crystal, a positive A plate is sufficient, and if the polymerizable liquid crystal compound is a discotic liquid crystal, a negative A plate is sufficient.

[0072] The retarder may include two or more retardation films with different optical anisotropies. To achieve a high level of anti-reflection function, it is sufficient to have a λ / 4 plate function (i.e., a π / 2 retardation function) across the entire visible light range. Specifically, a reverse wavelength dispersion λ / 4 retardation layer is preferred, or a combination of two or more retardation films with different orientations is preferable. For example, 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 combined. Furthermore, from the viewpoint of compensating for anti-reflection function in oblique directions, it is preferable to further include a layer having anisotropy in the thickness direction (a positive C plate). In particular, when the retarder includes a reverse wavelength dispersion λ / 4 retardation layer and a positive C plate, the effects of the present invention can be more pronounced. Furthermore, each retardation film may have a tilt orientation or a cholesteric orientation.

[0073] When two or more types of retardation films having different retarder orientations are laminated together, they can be laminated via an internal adhesive layer 42 of the retarder. From the viewpoint of suppressing corrosion of metal members included in the image display panel to which the optical laminate is laminated, the internal adhesive layer 42 of the retarder is preferably an adhesive layer having low moisture permeability.

[0074] In the optical laminate 1, iodine contained in the polarizer 22 and an antistatic agent contained in the pressure-sensitive adhesive layer 5, which will be described later, can migrate between layers and transfer to the retarder. In this case, if the retardation film is made of a polymerizable liquid crystal compound, the retardation characteristics will change (for example, increase) due to the influence of iodine and the antistatic agent. From this perspective, the water vapor permeability coefficient of the retarder is preferably 100 or less. This water vapor permeability coefficient is preferably 1 or more and 75 or less, more preferably 5 or more and 50 or less, and even more preferably 10 or more and 35 or less. Here, the "water vapor permeability coefficient" refers to the moisture permeability (unit: g / (m)) of the retarder at 65°C. 2 This refers to a value expressed by the product of the water vapor permeability (days) and the thickness (unit: mm). When iodine or an antistatic agent migrates between layers of the optical laminate 1, if the water vapor permeability coefficient of the retarder 4 is too high, the migration of iodine and the antistatic agent increases, and the degree of suppression of the change in retardation of the first or second retardation layer, which should suppress the change in retardation, and the effect of suppressing corrosion of the metal member tend to be reduced compared to their intended suppression effects. Furthermore, if the water vapor permeability coefficient is too low, the antistatic agent becomes excessively difficult to permeate, and therefore the antistatic agent is more likely to migrate toward the metal member. Therefore, it is preferable that the water vapor permeability coefficient of the retarder is appropriately low.

[0075] The λ / 4 function of the retarder over the entire visible light range preferably satisfies the optical characteristics shown in the following formula (1), where Re(λ) is the in-plane retardation value for light with a wavelength of λ nm, and more preferably satisfies the optical characteristics shown in the following formulas (1), (2), and (3): The in-plane retardation value Re(λ) of the retarder is a value measured by laminating a linear polarizer and a retarder in this order using a retardation measuring device (KOBRA-WPR, manufactured by Oji Scientific Instruments Co., Ltd.). 100nm <Re(550)<160nm (1) (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 (2) 1.00≦Re(650) / Re(550) (3) (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.)

[0076] The wavelength dispersion α of the retarder is preferably within a predetermined range. Here, "wavelength dispersion α" refers to the ratio (Re(450) / Re(550)) of the in-plane retardation value Re(450) at a wavelength of 450 nm to the in-plane retardation value Re(550) at a wavelength of 550 nm. Because the reverse wavelength dispersion is improved and the optical properties of the optical laminate are further improved, the wavelength dispersion α is preferably 0.70 or more, more preferably 0.78 or more. For the same reasons, the wavelength dispersion α is preferably 0.92 or less, more preferably 0.90 or less, even more preferably 0.88 or less, and particularly preferably 0.87 or less. The "Re(450) / Re(550)" value can be adjusted arbitrarily by adjusting the mixing ratio of the polymerizable liquid crystal compound, the stacking angle of multiple retardation films, and the retardation value.

[0077] 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 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. Re(λ)=d×Δn(λ) (4) (In the formula, Re(λ) represents the in-plane retardation value at a wavelength of λ nm, d represents the thickness, and Δn(λ) represents the birefringence at a wavelength of λ nm.)

[0078] 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 the optical characteristics expressed by formula (5). nx≒ny <nz (5)

[0079] 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 retardation value Rth(550) in the thickness direction 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. A thickness direction retardation value in this range can further improve anti-reflection properties from oblique directions.

[0080] The polymerizable liquid crystal compound contained in the retardation film-forming composition 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. 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 the photopolymerizable group include vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, oxiranyl, and oxetanyl groups. Among these, acryloyloxy, methacryloyloxy, vinyloxy, oxiranyl, 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-ordered structure of the thermotropic liquid crystal may be either nematic or smectic. The polymerizable liquid crystal compound may be either a rod-shaped liquid crystal or a discotic liquid crystal. The polymerizable liquid crystal compound may be used alone or in combination of two or more kinds.

[0081] 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): [ka] Examples of the compound include compounds represented by the following formula:

[0082] 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-. 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. L 1 , L 2 , B 1 and B 2 are each independently a single bond or a divalent linking group. 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. 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.

[0083] G 1 and G 2 are each independently preferably a 1,4-phenylenediyl group optionally substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, or a 1,4-cyclohexanediyl group optionally substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, more preferably a 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. 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.

[0084] 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-.

[0085] 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-.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] Suitable examples of the aromatic group represented by Ar include the following groups:

[0092] [ka]

[0093] 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.

[0094] Q 1 , Q 2 and Q 3 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.

[0095] J 1 , and J 2 each independently represents a carbon atom or a nitrogen atom.

[0096] Y 1 , Y2 and Y 3 each independently represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group.

[0097] 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.

[0098] Y 1 , Y 2 and Y 3 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.

[0099] Y 1 , Y 2 and Y 3 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.

[0100] Z 0 , Z 1 and Z 2 are each independently preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms; Z 0 is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, and Z 1 and Z 2is more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.

[0101] Q 1 , Q 2 and Q 3 -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.

[0102] Among the formulae (Ar-1) to (Ar-23), the formulae (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability. 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.

[0103] 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 the alignment and film thickness uniformity of the resulting retardation film can be improved. 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.

[0104] Examples of the discotic polymerizable liquid crystal compound include a compound containing a group represented by formula (W) (hereinafter also referred to as "polymerizable liquid crystal compound (W)"). [ka] [In formula (W), R 40 represents the following formulas (W-1) to (W-5). [ka] [In formulas (W-1) to (W-5), X 40 and Z 40 each independently 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-. m2 represents an integer.]

[0105] Examples of the rod-shaped polymerizable liquid crystal compound include compounds represented by formula (II), formula (III), formula (IV), formula (V), formula (VI) or formula (VII). P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (II) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (III) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (IV) P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (V) P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (VI) P11-B11-E11-B12-A11-B13-A12-F11 (VII) [In formulas (II) to (VII), A11 to A14 each independently represent a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. A hydrogen atom contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group, and 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. B11 and B17 each independently represent -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, or -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. B12 to B16 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 -, -NR16 represents -C(=O)-, -OCH2-, -OCF2-, -CH2O-, -CF2O-, -CH=CH-C(=O)-O-, -OC(=O)-CH=CH- or a single bond. E11 and E12 each independently represent an alkanediyl group having 1 to 12 carbon atoms, a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, a hydrogen atom contained in the alkoxy group may be substituted with a halogen atom, and -CH2- constituting the alkanediyl group may be substituted with -O- or -CO-. F11 represents a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group (-SO3H), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and -CH2- constituting the alkyl group and alkoxy group may be replaced with -O-. P11 and P12 each independently represent a polymerizable group.]

[0106] The content of the polymerizable liquid crystal compound in the composition for forming a retardation film 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 retardation film. A content of the polymerizable liquid crystal compound within the above range is advantageous from the viewpoint of the alignment of the resulting retardation 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.

[0107] (5-2) Composition for forming retardation film As described above, the retardation film-forming composition contains a polymerizable liquid crystal compound. The retardation film-forming composition may further contain reactive additives such as a solvent, a leveling agent, a polymerization initiator, a photosensitizer, a polymerization inhibitor, a crosslinking agent, and an adhesive agent, and preferably contains a solvent and a leveling agent from the viewpoint of processability.

[0108] The retardation film-forming composition may contain a solvent. Generally, polymerizable liquid crystal compounds have high viscosity, so that dissolving the composition in a solvent makes it easy to apply, and as a result, it often becomes easy to form a retardation film. 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.

[0109] Examples of the solvent 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, 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; 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.

[0110] The content of the solvent is preferably 50 to 98% by mass relative to the total amount of the retardation film-forming composition. In other words, the content of solids in the retardation film-forming composition is preferably 2 to 50% by mass, more preferably 5 to 30% by mass. When the content of solids is 50% by mass or less, the viscosity of the retardation film-forming composition is low, and the thickness of the retardation film becomes approximately uniform, which tends to reduce the occurrence of unevenness in the retardation film. The content of solids can be determined taking into consideration the thickness of the retardation film to be produced.

[0111] The retardation film-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 organically modified silicone-based, polyacrylate-based, and perfluoroalkyl-based leveling agents. Among them, when horizontal alignment is desired, polyacrylate-based leveling agents and perfluoroalkyl-based leveling agents are preferred, and when vertical alignment is desired, organically modified silicone-based leveling agents and perfluoroalkyl-based leveling agents are preferred.

[0112] When the retardation film-forming composition contains a leveling agent, the content 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. When the content of the leveling agent is within the above range, the polymerizable liquid crystal compound is easily horizontally aligned, and the obtained retardation film tends to be smoother. When the content of the leveling agent relative to the polymerizable liquid crystal compound exceeds the above range, the obtained retardation film tends to be uneven. The retardation film-forming composition may contain two or more types of leveling agents.

[0113] The retardation film-forming composition may contain a polymerization initiator. The polymerization initiator is a compound capable of initiating 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.

[0114] 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 under the action of light, and among these, photopolymerization initiators that generate radicals under the action of light are preferred.The photopolymerization initiators can be used alone or in combination of two or more.

[0115] 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 the photopolymerization initiator that generates acid, 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.

[0116] The content of the polymerization initiator in the retardation film-forming composition can be adjusted appropriately 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.

[0117] The retardation film-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.

[0118] When the retardation film-forming composition contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the retardation film-forming composition 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.

[0119] From the viewpoint of stably progressing the polymerization reaction, the retardation film-forming composition may contain an antioxidant. The antioxidant can control the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound.

[0120] 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.

[0121] When the retardation film-forming composition 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 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.

[0122] The retardation film-forming composition 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). Representative examples of such groups 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.

[0123] (5-3) Base material The substrate for forming the retardation film includes a glass substrate and a film substrate, preferably a film substrate, and more preferably a long roll film in terms of continuous production.The resin constituting the film substrate includes, for example, linear polyolefins such as polyethylene and polypropylene; cyclic olefin 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; etc.Among these, from the viewpoint of transparency when used in optical film applications, a film substrate selected from any of triacetyl cellulose, cyclic olefin resins, polymethacrylic acid esters, and polyethylene terephthalate is more preferred.

[0124] Examples of commercially available cellulose ester substrates include "Fujitac Film" (manufactured by Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (all manufactured by Konica Minolta Opto, Inc.). Examples of commercially available cyclic olefin resins 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. Commercially available cyclic olefin resin substrates can also be used. Commercially available cyclic olefin resin substrates include "ESCINA" (registered trademark) and "SCA40" (registered trademark) (both manufactured by Sekisui Chemical Co., Ltd.), "ZEONORFILM" (registered trademark) (manufactured by Optes Co., Ltd.), and "ARTONFILM" (registered trademark) (manufactured by JSR Corporation).

[0125] The thickness of the substrate 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 is usually 5 μm to 300 μm, preferably 10 μm to 200 μm, and more preferably 10 to 50 μm. Furthermore, by peeling off the substrate and transferring the retardation film, a further thinning effect can be obtained.

[0126] (5-4) Alignment film In this specification, the alignment film has an alignment regulating force that aligns the polymerizable liquid crystal compound in a desired direction.

[0127] The alignment film facilitates the alignment of the polymerizable liquid crystal compound. The alignment state of the liquid crystal, such as horizontal alignment, vertical alignment, hybrid alignment, or tilted alignment, varies depending on the properties of the alignment film and the polymerizable liquid crystal compound, and any combination thereof can be selected. 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 the like refer to the direction of the optical axis of the aligned polymerizable liquid crystal compound relative to the plane of the retardation film. For example, vertical alignment means that the optical axis of the aligned polymerizable liquid crystal compound is perpendicular to the plane of the retardation film. Here, vertical means 90°±20° relative to the plane of the retardation film.

[0128] 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.

[0129] The alignment film formed between the substrate and the retardation film is preferably insoluble in a solvent used when forming the retardation film on the alignment film, and has heat resistance in a heat treatment for removing the solvent and orienting the liquid crystal. Examples of the alignment film include an alignment film made of an orientable polymer, a photo-alignment film, a groove-alignment film, and a stretched film stretched in the alignment direction. When applied to a long roll film, a photo-alignment film is preferred because the alignment direction can be easily controlled.

[0130] 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.

[0131] 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 hydrolyzates 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.

[0132] 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.

[0133] 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 more preferable in that the direction of the alignment control force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light.

[0134] A photoreactive group is a group that exhibits liquid crystal alignment ability upon irradiation with light. Specifically, it is a group that undergoes a photoreaction that is the origin of liquid crystal alignment ability, such as molecular alignment induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction, upon irradiation with light. Among such photoreactive groups, those that undergo dimerization reaction or photocrosslinking reaction are preferred in terms of excellent alignment ability. As photoreactive groups capable of undergoing such reactions, those having an unsaturated bond, particularly a double bond, are preferred, and groups having at least one 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.

[0135] Examples of photoreactive groups having a C=C bond include vinyl groups, polyene groups, stilbene groups, stilbazole groups, stilbazolium groups, chalcone groups, and cinnamoyl groups. Chalcone groups and cinnamoyl groups are preferred 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.

[0136] 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 irradiating 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.

[0137] (6)Adhesive layer The optical laminate 1 of this embodiment includes three types of adhesive layers (adhesive layer in the linear polarizer, adhesive layer 3 between the linear polarizer and the phase shifter, and adhesive layer in the phase shifter).

[0138] The pressure-sensitive adhesive layer within the linear polarizer (not shown in FIG. 1) is a layer that is provided as a component of the linear polarizer 2, as necessary, for bonding the first protective film 21 and the polarizer 22 and for bonding the polarizer 22 and the second protective film 23. The optical laminate preferably includes both of these pressure-sensitive adhesive layers within the linear polarizer. The pressure-sensitive adhesive layer 3 between the linear polarizer and the retarder is a layer that is provided for bonding the linear polarizer 2 and the retarder 4. The optical laminate preferably includes the pressure-sensitive adhesive layer 3 between the linear polarizer and the retarder. The pressure-sensitive adhesive layer 42 within the retarder is a layer that is used for bonding the first retardation layer 41 (e.g., a λ / 4 retardation layer) and the second retardation layer 43 (e.g., a positive C plate) within the retarder 4.

[0139] The adhesive layer in the linear polarizer, the adhesive layer 3 between the linear polarizer and the phaser, and the adhesive layer 42 in the phaser may all be pressure-sensitive adhesive layers or adhesive layers. The adhesive layer is a layer formed from a pressure-sensitive adhesive composition (pressure-sensitive adhesive composition), and the adhesive layer is a layer formed from an adhesive composition. The adhesive layer in the linear polarizer and the adhesive layer 42 in the phaser are preferably adhesive layers. In particular, the adhesive layer 42 in the phaser preferably has low moisture permeability from the viewpoint of suppressing the migration of an antistatic agent, which will be described later, and is therefore preferably made of an active energy ray-curable adhesive. Furthermore, in order to suppress cracking of the phaser, an adhesive layer having a higher elastic modulus than the adhesive layer is preferred. On the other hand, the adhesive layer 3 between the linear polarizer and the phaser is preferably a pressure-sensitive adhesive layer.

[0140] (6-1) Adhesive layer Examples of adhesive compositions that form the adhesive layer 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.

[0141] 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.

[0142] The cationically polymerizable compound is a compound or oligomer that undergoes 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 include epoxy compounds, oxetane compounds, and vinyl compounds. 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.

[0143] 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.

[0144] 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.

[0145] Examples of cationic polymerization adhesive compositions include the cationic polymerization compositions described in JP 2016-126345 A and JP 2021-113969 A.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] The bonding of two layers with an adhesive layer can be carried out by applying an adhesive composition to at least one of the bonding surfaces selected from the bonding surfaces of each of the two layers, overlapping the two layers with the coating layer of the adhesive composition interposed therebetween, pressing them together from above and below using a bonding roll or the like, and then drying the adhesive layer, curing it by irradiating it with active energy rays, or curing it by heating.

[0152] Before forming the coating layer of the adhesive layer, at least one of the bonding surfaces of the two layers may be subjected to an adhesion-improving treatment such as saponification treatment, corona treatment, plasma treatment, primer treatment, anchor coating treatment, etc. Various coating methods can be used to form the coating layer of the adhesive composition, such as a die coater, comma coater, gravure coater, wire bar coater, doctor blade coater, etc.

[0153] 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:

[0154] 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.

[0155] 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. 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, and may be 0.1 μm or more, preferably 0.5 μm or more, and more preferably 1 μm or more.

[0156] (6-2) Adhesive layer The pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer can be any conventionally known pressure-sensitive adhesive composition with excellent optical transparency, and can be used without any particular limitation. For example, a pressure-sensitive adhesive composition having a base polymer such as a (meth)acrylic resin, a urethane resin, a silicone resin, or a polyvinyl ether resin can be used. Active energy ray-curable pressure-sensitive adhesive compositions and heat-curable pressure-sensitive adhesive compositions are also suitable. Among these, pressure-sensitive adhesive compositions having a (meth)acrylic resin as a base polymer, which is excellent in transparency, adhesive strength, removability, weather resistance, heat resistance, etc., are preferred. The pressure-sensitive adhesive composition may further contain a crosslinking agent, a silane compound, an antistatic agent, etc.

[0157] [(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 per 100 parts by mass of the structural units of the (meth)acrylic resin) a structural unit derived from a (meth)acrylic acid alkyl ester represented by the following formula (VIII) (hereinafter also referred to as "structural unit (VIII)"): [ka] [In formula (VIII), 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.

[0158] Examples of the (meth)acrylic acid ester represented by formula (VIII) 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, Examples of the alkoxy group-containing alkyl acrylate include n-octyl (meth)acrylate, i-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n- and i-nonyl (meth)acrylate, n-decyl (meth)acrylate, i-decyl (meth)acrylate, n-dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, stearyl (meth)acrylate, and t-butyl (meth)acrylate. Specific examples of the alkoxy group-containing alkyl acrylate include 2-methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and 2-methoxy-2-ethoxyethyl (meth)acrylate. In particular, the alkoxy group-containing acrylate preferably accounts for 10% to 40% by mass, preferably 15% to 40% by mass, more preferably 15% to 35% by mass, and particularly preferably 20% to 35% by mass, based on the total amount of structural units constituting the (meth)acrylic resin (VIII). If this content is less than 10% by mass, the ionic conductivity of the adhesive is low, requiring the addition of a large amount of antistatic agent to ensure the desired antistatic properties, resulting in reduced metal corrosion resistance. If the content exceeds 40% by mass, the polarity of the adhesive increases, resulting in a high moisture content and adversely affecting adhesive properties. Among these, n-butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate is preferred as the alkyl acrylate, and n-butyl (meth)acrylate is particularly preferred. Furthermore, 2-methoxyethyl acrylate is preferred as the alkoxy group-containing acrylate.

[0159] The (meth)acrylic acid ester polymer may contain a structural unit derived from a monomer other than the structural unit (VIII). 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 a (meth)acrylamide-based monomer.

[0160] 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 unsubstituted or substituted amino group substituted with an alkyl group having 1 to 6 carbon atoms, and a heterocyclic group such as an epoxy group.

[0161] The content of the structural units derived from the monomer having a polar functional group 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.

[0162] 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, a phenoxyethyl group, or a 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.

[0163] The content of the structural units derived from the monomer 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.

[0164] Examples of (meth)acrylamide monomers include N-(methoxymethyl)(meth)acrylamide, N-(ethoxymethyl)(meth)acrylamide, N-(propoxymethyl)(meth)acrylamide, N-(butoxymethyl)(meth)acrylamide, N-(2-methylpropoxymethyl)(meth)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.

[0165] Furthermore, structural units derived from monomers other than the structural unit (VIII) 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.

[0166] The weight-average molecular weight (hereinafter also simply referred to as "Mw") of the (meth)acrylic resin is preferably 500,000 to 2,500,000. When the weight-average molecular weight is 500,000 or more, the durability of the pressure-sensitive adhesive layer in high-temperature and high-humidity environments can be improved. When the weight-average molecular weight is 2,500,000 or less, operability during application of a coating liquid containing the pressure-sensitive adhesive composition is improved. In this specification, "weight-average molecular weight" and "number-average molecular weight" are polystyrene-equivalent values measured by gel permeation chromatography (GPC).

[0167] 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, the occurrence of streaks during the production of a pressure-sensitive adhesive layer formed from the resin can be suppressed. The viscosity can be measured using a Brookfield viscometer.

[0168] The glass transition temperature (Tg) of the (meth)acrylic resin is preferably in the range of −10 to −60° C., more preferably in the range of −20 to −50° C., and even more preferably in the range of −30 to −45° C. The glass transition temperature can be measured by a differential scanning calorimeter (DSC).

[0169] 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 those having a weight-average molecular weight smaller than that of the above-mentioned (meth)acrylic acid ester polymers having a weight-average molecular weight of 500,000 to 2,500,000. More specifically, examples include (meth)acrylic acid ester polymers having a relatively low molecular weight, mainly composed of a structural unit (VIII) derived from a (meth)acrylic acid ester, and having a weight-average molecular weight in the range of 50,000 to 300,000.

[0170] (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.

[0171] [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 particularly 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 optical laminate.

[0172] 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.

[0173] The proportion of the crosslinking agent is, for example, 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, and even more preferably 0.1 to 1 part by mass, relative to 100 parts by mass of the (meth)acrylic resin.

[0174] [Silane compounds] The pressure-sensitive adhesive composition may further contain a silane compound. 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. The silane compound may also contain an oligomer derived from the above silane compound.

[0175] The content of the silane compound in the pressure-sensitive adhesive composition is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, and more preferably 0.1 to 1 part 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.

[0176] [Antistatic agent] The adhesive layer may contain an antistatic agent. As the antistatic agent, those shown in "(7) Adhesive layer" below can be used.

[0177] [others] 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.

[0178] The adhesive layer can be formed, for example, by dissolving or dispersing the adhesive composition in a solvent to form a solvent-containing adhesive composition, which is then applied to the surface of a substrate or a layer on which the adhesive layer is to be formed, and drying.

[0179] 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.

[0180] (7) Adhesive layer The optical laminate 1 includes a pressure-sensitive adhesive layer 5 laminated on the side of the retarder 4 opposite to the linear polarizer 2. The basic structure of the pressure-sensitive adhesive layer 5 is the same as that described above in "(6-2) Pressure-sensitive adhesive layer." Here, the antistatic agent and thickness will be described.

[0181] [Antistatic agent] The pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer 5 contains an antistatic agent, and the antistatic agent contains an ionic compound composed of an organic cation and an anion represented by the following formula (1). (C n F 2n+1 SO2)2N - …(1) (In the formula, n is an integer of 0 to 5.)

[0182] An example of the anion represented by formula (1) is bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N - ] and bis(fluorosulfonyl)imide anion [(FSO2)2N - ] anions.

[0183] Examples of organic cations include ammonium cations such as tributylmethylammonium cation, trioctylmethylammonium cation, trimethylpropylammonium cation, tetrabutylammonium cation, and (2-hydroxyethyl)trimethylammonium cation; phosphonium cations such as tributyldodecylphosphonium cation; pyridinium cations such as 1-hexylpyridinium cation, 1-octylpyridinium cation, 4-methyl-1-hexylpyridinium cation, 4-methyl-1-octylpyridinium cation, and 4-methyl-1-butylpyridinium cation; pyrrolidinium cations such as butylmethylpyrrolidinium cation and ethylmethylpyrrolidinium cation; imidazolium cations such as 1-ethyl-3-methylimidazolium cation and 1-butyl-3-methylimidazolium cation; pyrrolidinium cation; alkylammonium cation; sulfonium cation. Among these, pyrrolidinium cations and alkylammonium cations are particularly preferred because they are less likely to move between layers of the optical laminate 1. In addition, organic cations containing a nitrogen atom are preferred, and from the viewpoint of suppressing fluctuations in retardation characteristics when an aromatic ring-containing compound is transferred to a retarder during durability evaluation, aliphatic cations are more preferred, and pyrrolidinium cations and alkylammonium cations are even more preferred.

[0184] In view of excellent stability over time of the antistatic performance of the pressure-sensitive adhesive composition, an ionic compound that is solid at room temperature (having a melting point of 23° C. or higher) is preferred. The molecular weight of the ionic compound is not particularly limited, but is preferably, for example, 700 or less, more preferably 500 or less.

[0185] The content of the antistatic agent is, for example, 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, more preferably 0.1 to 2.5 parts by mass, and even more preferably 0.1 to 1.5 parts by mass, relative to 100 parts by mass of the nonvolatile content of the resin constituting the pressure-sensitive adhesive layer. It is preferable to contain 0.1 part by mass or more of the antistatic agent relative to 100 parts by mass of the nonvolatile content of the resin constituting the pressure-sensitive adhesive layer, as this improves antistatic performance. Furthermore, it is preferable to contain the amount of 10 parts by mass or less, as this can suppress bleeding of the ionic compound from the pressure-sensitive adhesive layer during a durability test, making it easier to maintain durability.

[0186] The thickness T3 of the pressure-sensitive adhesive layer 5 is usually 5 μm or more, preferably 10 μm or more. The thickness T3 of the pressure-sensitive adhesive layer 5 is usually 35 μm or less, preferably 30 μm or less.

[0187] <Image display device> The image display device includes the optical laminate according to the present invention 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. The optical laminate can be attached to the image display element using a pressure-sensitive adhesive layer 5.

[0188] 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.

[0189] 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.

[0190] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. In the optical laminate 1 of the above embodiment, the outermost layers are the first protective film 21 and the pressure-sensitive adhesive layer 5. However, if necessary, the first protective film 21 may be provided with a surface protective film for protecting its surface, and the pressure-sensitive adhesive layer 5 may be provided with a separator. [Example]

[0191] Below are examples , reference example The present invention will be described in more detail with reference to the following examples and comparative examples. It should be noted that the present invention is not limited to the following examples. In the following description, parts and percentages representing amounts used and contents are based on mass unless otherwise specified. Furthermore, in the following description, numbers such as "second protective film 3" and "adhesive layer 1" represent the types of the multiple types of second protective films, adhesive layers, etc. used, and are unrelated to the symbols in the drawings.

[0192] <Measurement and Evaluation> (1) Thickness of the layer or film Unless otherwise specified, the thickness of a layer or film was measured using a laser microscope (Olympus Corporation, "LEXT") or a digital micrometer (Nikon Corporation, "MH-15M").

[0193] (2) In-plane retardation value of layer or film The in-plane retardation values [nm] of the layer or film at wavelengths of 550 nm and 450 nm were measured using a retardation measuring device (KOBRA-WPR, manufactured by Oji Scientific Instruments Co., Ltd.).

[0194] (3) Moisture permeability of protective film The moisture permeability of the second protective film was measured under the following measurement conditions. Test item: Water vapor permeability Test method: Humidity sensor method Measurement equipment: Lyssy L80 series water vapor transmission meter Sample preparation method: An aluminum mask was attached to the surface of the second protective film in a laminate containing a supporting substrate and a second protective film (described below), and then the supporting substrate was peeled off, and another aluminum mask was attached to the peeled surface to prepare a measurement sample. The second protective film 8 (a triacetyl cellulose film with a thickness of 20 μm) used in Comparative Example 1 did not have a supporting substrate, so the supporting substrate was not peeled off. Measurement conditions Measurement temperature: 40℃ Relative humidity: 90%RH Measurement area: Second protective film 1-4: 7.1 x 10 -4 m 2 (Transmission area when wearing a mask) Second protective film 5: 7.9 x 10 -5 m 2 (Transmission area when wearing a mask) Measurement sample installation direction: Any

[0195] (4) Water vapor permeability coefficient of the retarder The water vapor permeability coefficient of the phase shifter was measured by the same procedure as in (3) above, except that the measurement temperature was set to 65°C. 2 This was calculated by multiplying the calculated value by the thickness (unit: mm).

[0196] (5) Evaluation of phase difference change The change in in-plane retardation value when the optical laminate was placed in a high-temperature, humid, and hot environment was measured and evaluated according to the following procedure. A 30 mm × 30 mm sample was cut from the optical laminate, with the retarder's slow axis aligned along the long side. The sample was attached to alkali-free glass (manufactured by Corning, product number: EAGLE XG (registered trademark)) via its antistatic adhesive layer to prepare an evaluation sample. The in-plane retardation values of the evaluation sample were measured at wavelengths of 550 nm and 450 nm using a retardation measurement device (manufactured by Oji Scientific Instruments, KOBRA-WPR). The obtained values were used to calculate the change in in-plane retardation value ΔRe(550) and wavelength dispersion α (in-plane retardation value Re(450) / in-plane retardation value Re(550)). Five evaluation samples were measured, and the average values were calculated.

[0197] The evaluation sample was placed in an oven and subjected to a 336-hour wet heat durability test at a temperature of 60°C and a relative humidity of 90%RH. The evaluation sample was removed from the oven, and after 3 hours, the in-plane retardation values at wavelengths of 550 nm and 450 nm were measured using the retardation measurement device described above, and the change in in-plane retardation value ΔRe(550) before and after the heat resistance test was calculated. A: ΔRe(550) is less than 0.5 B: ΔRe(550) is 0.5 or more and less than 0.7 C: ΔRe(550) is 0.7 or more

[0198] The evaluation sample was placed in an oven and subjected to a 504-hour moist heat durability test at a temperature of 60°C and a relative humidity of 90%RH. The evaluation sample was removed from the oven, and three hours later, the in-plane retardation values at wavelengths of 550 nm and 450 nm were measured using the retardation measurement device described above. The amount of change was calculated from the wavelength dispersion α (0 hours) before the heat resistance test and the wavelength dispersion α (504 hours) after the heat resistance test, and Δα, the rate of change in α, was calculated according to the following formula. Of the following criteria, A indicates the smaller change in wavelength dispersion α. Δα(%)=(α(504 hours)-α(0 hours)) / α(0 hours)×100 A: |Δα| is less than 0.2 B: |Δα| is 0.2 or more

[0199] (6) Evaluation of metal corrosion using optical laminates A metal layer-attached glass substrate was prepared by laminating a metal aluminum layer and a metal titanium layer in this order on the surface of an alkali-free glass substrate by sputtering. , reference example The optical laminates obtained in the comparative examples were cut into pieces measuring 50 mm x 50 mm, and the titanium metal layer side of a glass substrate with a metal layer was attached to the adhesive layer of the optical laminate to prepare evaluation samples. The evaluation samples were stored in an oven at a temperature of 85°C and a relative humidity of 85%RH for 350 hours, and then removed from the oven. The evaluation samples were placed on a backlight with the glass substrate facing down, and the number and size of bright spots due to light leakage were observed to evaluate metal corrosion according to the following criteria. A+: No bright spots A: 1 to 5 bright spots of 0.1 to 0.5 mm B+: 6 to 15 bright spots of 0.1 to 0.5 mm or 5 bright spots of 0.5 to 1.0 mm B: 6 to 15 bright spots of 0.5 to 1.0 mm C: More than 15 bright spots are observed over the entire surface, but there are some areas where there are no bright spots.

[0200] [Fabrication of polarizer] (1) Preparation of polarizer 1 A polyvinyl alcohol film having a thickness of 20 μm, a degree of polymerization of 2400, 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, was immersed for 60 seconds in a dye bath at 28°C containing 0.05 parts of iodine and 5 parts of potassium iodide per 100 parts of water.

[0201] Next, the film was immersed for 110 seconds in a boric acid aqueous solution 1 at 64°C containing 5.5 parts of boric acid and 15 parts of potassium iodide per 100 parts of water. The film was then immersed for 30 seconds in a boric acid aqueous solution 2 at 67°C containing 5.5 parts of boric acid and 15 parts of potassium iodide per 100 parts of water. The film was then washed with pure water at 3°C and dried to obtain a polarizer 1. The boron content of the polarizer 1 measured by the above method was 4.1% by mass. The polarizer had a thickness of 8 μm.

[0202] (2) Preparation of polarizer 2 A 30 μm-thick polyvinyl alcohol-based resin film (average degree of polymerization: approximately 2400, saponification degree: 99.9 mol% or more) was uniaxially stretched longitudinally by approximately 5 times by dry stretching. While still under tension, the film was immersed in pure water at 60°C for 1 minute, then in an aqueous solution at 28°C with an iodine / potassium iodide / water mass ratio of 0.05 / 5 / 100 for 60 seconds. The film was then immersed in an aqueous solution at 72°C with a potassium iodide / boric acid / water mass ratio of 8.5 / 8.5 / 100 for 300 seconds. The film was then washed with pure water at 26°C for 20 seconds and dried at 65°C to obtain a 12 μm-thick linear polarizer in which iodine was adsorbed and aligned in the polyvinyl alcohol-based resin film.

[0203] [Protective film preparation] (1) Preparation of First Protective Film 1 First protective film 1 was prepared by forming a 7 μm thick hard coat layer (thickness T1: 32 μm) on one side of a triacetyl cellulose (TAC) film (KC2UATAC manufactured by Konica Minolta, Inc., thickness T1: 25 μm).

[0204] (2) Preparation of second protective film 1 A 38 μm-thick polyethylene terephthalate film (PET film) ("TN100" manufactured by Toyobo Co., Ltd., having a release layer containing a non-silicone release agent) was prepared as a supporting substrate. The following components were blended to prepare a composition containing a thermoplastic resin. Cyclic polyolefin resin (ZEON Corporation's "ZEONOR ZF14"): 10 parts Cyclohexane: 90 parts

[0205] The composition containing the thermoplastic resin was applied onto the release layer of the support substrate using a die by back coating, and the applied layer was dried at 40°C for 1 minute, 70°C for 1 minute, and 120°C for 2 minutes to produce a laminate having a cyclic polyolefin resin layer with a thickness T2 of 2 μm as the second protective film 1. The moisture permeability of the second protective film 1 was 63 g / m 2 / 24hr.

[0206] (3) Preparation of second protective film 2 A laminate having a cyclic polyolefin resin layer with a thickness T2 of 3 μm was prepared as second protective film 2 in the same manner as second protective film 1, except that the amount of the thermoplastic resin-containing composition applied to the release layer of the supporting substrate was changed. The moisture permeability of second protective film 2 was 37 g / m 2 / 24hr.

[0207] (4) Preparation of second protective film 3 A laminate having a cyclic polyolefin resin layer with a thickness T2 of 4 μm was prepared as the second protective film 3 in the same manner as the second protective film 1, except that the amount of the thermoplastic resin-containing composition applied to the release layer of the supporting substrate was changed. The moisture permeability of the second protective film 3 was 19 g / m 2 / 24hr.

[0208] (5) Preparation of second protective film 4 A cyclic polyolefin resin film having a thickness T2 of 13 μm was prepared as the second protective film 4. The moisture permeability of the second protective film 4 was 4.8 g / m 2 / 24hr.

[0209] (6) Preparation of second protective film 5 A triacetyl cellulose film having a thickness of 25 μm was prepared as the second protective film 5. The moisture permeability of the second protective film 5 was 1280 g / m 2 / 24 hr.

[0210] [Preparation of active energy ray curable adhesive] (1) Preparation of active energy ray curable adhesive 1 The following components were blended and mixed, and then degassed to prepare an active energy ray-curable adhesive 1 (hereinafter simply referred to as "adhesive 1"). (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

[0211] [Preparation of adhesive layer] The following adhesive layer 1 and adhesive layer 2 were prepared, each having a release film attached to both sides. (1) Preparation of adhesive layer 1 The adhesive layer 1 was prepared by the following procedure. and reference examplesIn the case of the present invention, it is mainly used as an adhesive layer between a linear polarizer and a phase shifter, and in some cases, it is used as an adhesive layer inside the phase shifter.

[0212] (1-1) 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 inside 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. When the 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 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. The Mw was measured in terms of standard polystyrene using two "TSKgel GMHHR-H(S)" columns manufactured by Tosoh Corporation connected in series as columns in a GPC apparatus, tetrahydrofuran as an eluent, a sample concentration of 2 mg / mL, a sample introduction amount of 100 μL, a temperature of 40°C, and a flow rate of 1 mL / min.

[0213] (1-2) Preparation of Pressure-Sensitive Adhesive Composition 1 Based on 80 parts of the solid content of the acrylic resin solution 1 obtained in (1-1) above, 20 parts (solid content) of a bifunctional acrylate (obtained from Shin-Nakamura Chemical Co., Ltd.; product number "A-DOG"), 2.5 parts of a crosslinking agent (manufactured by Mitsui Chemicals: trade name "D-101E" (ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate (solid content concentration 75% by mass)) based on the active ingredient, 1.5 parts of a photoinitiator (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. Further, ethyl acetate was added so that the solid content concentration became 13% to obtain an adhesive composition 1.

[0214] A-DOG is a diacrylate of an acetal compound of hydroxypivalaldehyde and trimethylolpropane and has the structure of the following formula.

Chemical formula

[0215] (1-3) Preparation of the adhesive layer 1 The adhesive composition 1 prepared in (1-2) above was applied to the release-treated surface of a release film made of a polyethylene terephthalate film (manufactured by Mitsubishi Chemical: MRV (V04) (thickness: 38 μm)) using an applicator so that the thickness T3 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 opposite to the release film side was bonded to the release-treated surface of a release film made of a polyethylene terephthalate film (manufactured by Mitsubishi Chemical: MRF (thickness: 38 μm)). Subsequently, ultraviolet rays were irradiated under the following conditions to prepare the adhesive layer 1. The storage modulus G' of the adhesive layer 1 at a temperature of 85°C was 0.125 MPa. <UV irradiation conditions> ·Using a Fusion UV lamp system (manufactured by Fusion UV Systems) H bulb ·Integrated light amount of the UV wavelength region UVA is 250 mJ / cm 2 (Measured value by UV Power PuckII manufactured by FusionUV)

[0216] (2) Preparation of adhesive layer 2 The acrylic pressure-sensitive adhesive layer 2 was prepared by the following procedure. The pressure-sensitive adhesive layer 2 contained an antistatic agent. and reference examples In the case of the present invention, it is used as an adhesive layer to be stuck to the side of the retarder opposite to the linear polarizer side.

[0217] (2-1) Preparation of acrylic resin solution 2 A monomer mixture prepared by diluting 42.5 parts by mass of n-butyl acrylate, 5 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of methyl acrylate, 30 parts by mass of 2-methoxyethyl acrylate, 1.0 part by mass of 2-hydroxyethyl acrylate, and 1.5 parts by mass of acrylic acid with ethyl acetate was charged into a reaction vessel equipped with a condenser, a nitrogen inlet tube, a thermometer, and a stirrer, and the air inside the vessel was purged with nitrogen gas to remove oxygen, while the internal temperature was raised to 55° C. Thereafter, a solution of azobisisobutyronitrile dissolved in ethyl acetate as a polymerization initiator was added such that the amount of azobisisobutyronitrile was 0.3 parts by mass per 100 parts by mass of the total amount of monomers. After adding the polymerization initiator, the temperature was maintained at 55°C for 1 hour. Then, while maintaining the internal temperature at 54-56°C, ethyl acetate was continuously added to the reactor at a rate of 17.3 parts / hr. When the acrylic resin concentration reached 35%, the addition of ethyl acetate was stopped and the temperature was maintained at 55°C for 12 hours. Ethyl acetate was then added to adjust the acrylic resin concentration to 20%, preparing acrylic resin solution 2. The weight-average molecular weight (Mw) of the resulting acrylic resin was 1.58 million.

[0218] (2-2) Preparation of Pressure-Sensitive Adhesive Composition 2 Adhesive composition 2-1 To 100 parts by mass of the solid content of the acrylic resin solution 2 obtained above, 0.5 parts by mass (active ingredient) of a crosslinking agent, trade name "D-103" manufactured by Mitsui Chemicals, Inc. (an ethyl acetate solution of a trimethylolpropane adduct of tolylene diisocyanate (solid content concentration 75% by mass)), 0.5 parts by mass (active ingredient) of a silane compound, trade name "KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd. (3-glycidoxypropyltrimethoxysilane), and 0.54 parts by mass (active ingredient) of tributylmethylammonium bis(trifluoromethanesulfonyl)imide as an ionic compound were added, and ethyl acetate was further added to adjust the solid content to 14%, thereby obtaining a pressure-sensitive adhesive composition 2-1 for producing a pressure-sensitive adhesive layer "AS-PSA1" described below. Adhesive composition 2-2 Pressure-sensitive adhesive composition 2-2 for producing the pressure-sensitive adhesive layer "AS-PSA2" described below was obtained in the same manner as in the preparation of "(AS-PSA1)" above, except that the ionic compound was changed to butylmethylpyrrolidinium bis(trifluoromethanesulfonyl)imide in an amount of 0.47 parts by mass based on the active ingredient. Adhesive composition 2-3 Pressure-sensitive adhesive composition 2-3 for producing the pressure-sensitive adhesive layer "AS-PSA3" described below was obtained in the same manner as in the preparation of "(AS-PSA1)" above, except that the ionic compound was changed to 4-methyl-1-octylpyridinium bis(trifluoromethanesulfonyl)imide in an amount of 0.51 parts by mass based on the active ingredient. Adhesive composition 2-4 Pressure-sensitive adhesive composition 2-4 for producing the pressure-sensitive adhesive layer "AS-PSA4" described below was obtained in the same manner as in the preparation of "(AS-PSA1)" above, except that the ionic compound was changed to 4-methyl-1-octylpyridinium hexafluorophosphate in an amount of 0.41 parts by mass based on the active ingredient.

[0219] (2-3) Preparation of adhesive layers AS-PSA1, AS-PSA2, AS-PSA3, and AS-PSA4 The pressure-sensitive adhesive composition 2-1 obtained above was applied using an applicator to the release-treated surface of a release film (1) (manufactured by Mitsubishi Chemical Corporation, trade name "MRV38(V04)", thickness: 38 μm) so that the dried thickness would be 15 μm, and then dried at a temperature of 100°C for 1 minute to obtain a pressure-sensitive adhesive layer (1) with a thickness of 15 μm. A release film (2) (manufactured by Mitsubishi Chemical Corporation, trade name "MRF38", thickness: 38 μm) was laminated on the opposite side of the obtained pressure-sensitive adhesive layer (1) from the release film (1), with the release-treated surface facing the pressure-sensitive adhesive layer (1). The obtained laminate was left to stand for 7 days or more in an environment at a temperature of 23°C and a relative humidity of 60%, to obtain a pressure-sensitive adhesive layer AS-PSA1. Furthermore, pressure-sensitive adhesive layers AS-PSA2, AS-PSA3, and AS-PSA4 were obtained in the same manner as above, except that pressure-sensitive adhesive compositions 2-2, 2-3, and 2-4 were used as the pressure-sensitive adhesive compositions, respectively. These pressure-sensitive adhesive layers AS-PSA1, AS-PSA2, AS-PSA3, and AS-PSA4 are collectively referred to as "pressure-sensitive adhesive layer 2."

[0220] [Fabrication of the phase shifter] (1) Preparation of retardation film A (1-1) Preparation of composition A for forming photo-alignment film The photo-alignment material (weight average molecular weight: 50,000, m:n = 50:50) having 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 A for forming a photo-alignment film. Photoalignable materials: [ka]

[0221] (1-2) Preparation of polymerizable liquid crystal compounds 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]

[0222] A solution was obtained by dissolving 1 mg of polymerizable liquid crystal compound (A1) in 10 mL of chloroform. The obtained solution was placed in a measurement cell with an optical path length of 1 cm, and the measurement sample was placed in an ultraviolet-visible spectrophotometer (Shimadzu Corporation, "UV-2450") to measure the absorption spectrum. The wavelength at which the maximum absorbance was obtained was read from the obtained absorption spectrum, and the maximum absorption wavelength λmax in the wavelength range of 300 to 400 nm was 356 nm.

[0223] (1-3) Preparation of Retardation Film-Forming Composition A 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 leveling agent "BYK-361N" (manufactured by BM Chemie) 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 so that the solids concentration became 13%. This mixture was stirred at a temperature of 80°C for 1 hour to prepare a retardation film-forming composition A.

[0224] (1-4) Preparation of retardation film A The photo-alignment film-forming composition A was applied to a biaxially stretched polyethylene terephthalate (PET) film (Diafoil; manufactured by Mitsubishi Plastics, Inc.) as the substrate A 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 film. The film was then irradiated with 100 mJ of polarized ultraviolet light (313 nm standard) using a UV irradiation device (SPOT CURE SP-9; manufactured by Ushio Inc.) to obtain a photo-alignment film A. The film thickness of the photo-alignment film A was measured using an ellipsometer M-220 manufactured by JASCO Corporation and was 100 nm.

[0225] The retardation film-forming composition A was applied onto the obtained photo-alignment film A 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, a high-pressure mercury lamp ("Uniqure VB-15201BY-A" manufactured by Ushio Inc.) was used to expose the film to light at a dose of 500 mJ / cm under a nitrogen atmosphere. 2 The dried film was irradiated with ultraviolet light (365 nm as the reference wavelength) to form a retardation film A in which the polymerizable liquid crystal compound was cured in a state of being aligned horizontally relative to the surface of the substrate, thereby obtaining a laminate A consisting of substrate A / photo-alignment film A / retardation film A. The thickness of retardation film A was 2.0 μm as measured using a laser microscope LEXT OLS4100 manufactured by Olympus Corporation.

[0226] The surface of retardation film A of laminate A was subjected to corona treatment, and the laminate was attached to glass via a 25 μm-thick adhesive layer (manufactured by Lintec Corporation), and then substrate A was peeled off and removed. 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 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.)

[0227] (2) Preparation of retardation film B (2-1) Preparation of Composition B for Forming Alignment Film A composition B for forming an alignment film was obtained by adding 2-butoxyethanol to a commercially available alignment polymer, Sunever SE-610 (manufactured by Nissan Chemical Industries, Ltd.), so that the solid content was 1%.

[0228] (2-2) Preparation of Retardation Film-Forming Composition B 100 parts of polymerizable liquid crystal compound Paliocolor LC242 (manufactured by BASF Japan Ltd.), 0.1 parts of leveling agent "BYK-361N" (manufactured by BYK-Chemie), and 2.5 parts of photopolymerization initiator "Omnirad907" (manufactured by IGM Resin BV) were mixed. Further, 400 parts of propylene glycol 1-monomethyl ether 2-acetate (PGME) was added, and the resulting mixture was stirred at a temperature of 80°C for 1 hour to prepare retardation film-forming composition B. Polymerizable liquid crystal compound LC242: [ka]

[0229] (2-3) Preparation of retardation film B A cyclic olefin resin (COP) film (ZF14, manufactured by Zeon Corporation) was used as the substrate B, and one side of the film was subjected to corona treatment using a corona treatment device (AGF-B10, manufactured by Kasuga Electric Co., Ltd.). Composition B for forming an alignment film was applied to the surface using a bar coater and dried for 1 minute at 90° C. The film thickness of the resulting alignment film B was measured with a laser microscope and found to be 30 nm.

[0230] On the obtained alignment film B, the composition B for forming a retardation film was applied using a bar coater and dried at 90 °C for 1 minute to obtain a dried film. Using a high-pressure mercury lamp (「Unicure VB-15201BY-A」manufactured by Ushio Electric Co., Ltd.), ultraviolet light with an exposure amount of 1000 mJ / cm 2 (based on 365 nm) was irradiated onto the dried film to form a retardation film B, and a laminate B composed of substrate B / alignment film B / retardation film B was obtained. The film thickness of the retardation film B measured using a laser microscope LEXT OLS4100 manufactured by Olympus Corporation was 450 nm.

[0231] When the retardation value was measured, Re(550) = 1 nm and Rth(550) = -75 nm. The laminate B had optical properties represented by nx ≈ ny < nz. Since the retardation value of COP at a wavelength of 550 nm is approximately 0, it does not affect the optical properties.

[0232] (3) Fabrication of Phase Element 1 Corona treatment was performed on the retardation film A of the laminate A and the retardation film B of the laminate B, respectively. An adhesive was applied to the corona-treated surface of either the retardation film A or the retardation film B, and the laminate A and the laminate B were bonded together. The above adhesive 1 was used as the adhesive. An AGF-B10 manufactured by Kasuga Electric Co., Ltd. was used as the corona treatment apparatus. The corona treatment was performed once using the above corona treatment apparatus under the conditions of an output of 0.3 kW and a treatment speed of 3 m / min. Ultraviolet light was irradiated from the laminate A side to cure the adhesive 1, and an adhesive layer 1 with a thickness of 1.5 μm was formed. The ultraviolet light was irradiated so that UVA with a wavelength of 320 nm to 390 nm was 420 mJ / cm 2 as described above. Thus, a phase element 1 with a substrate composed of substrate A / photo-alignment film A / retardation film A / adhesive layer 1 / retardation film B / alignment film B / substrate B was fabricated.

[0233] (4) Fabrication of Phase Element 2 Retarder 2 was produced in the same manner as retarder 1, except that in producing retarder 1, laminate A and laminate B were bonded together using pressure-sensitive adhesive layer 1 instead of adhesive 1. In this way, retarder 2 with a substrate, consisting of substrate A / photo-alignment film A / retardation film A / pressure-sensitive adhesive layer 1 / retardation film B / alignment film B / substrate B, was produced.

[0234] <Example 1~ 8, Reference example 9~ 12. Comparative Example 1 The first protective film 1 prepared above, a polarizer selected from the polarizers 1 and 2, a protective film selected from the second protective films 1 to 5, and a retarder selected from the retarders 1 and 2 were bonded together. Next, a pressure-sensitive adhesive layer was laminated on the surface of the retarder opposite to the second protective film side, to obtain the retarder of Examples 1 to 2. 8, Reference example 9~ Optical laminates of No. 12 and Comparative Example 1 were obtained. Specifically, the following is the procedure.

[0235] Corona treatment was performed on one side of each of the first and second protective films (or the surface of the second protective film of the laminate when a laminate having a second protective film was used). A water-based adhesive was applied to one side of the polarizer, and the first protective film was attached to it. A water-based adhesive was applied to the other side of the polarizer, and the second protective film (or a laminate having a second protective film) was attached to it. The resulting film was then dried to obtain a polarizing plate. The water-based adhesive was prepared by dissolving 3 parts of carboxyl-modified polyvinyl alcohol (available from Kuraray Co., Ltd. under the trade name "KL-318") in 100 parts of water, and adding 1.5 parts of a polyamide epoxy-based additive (a 30% solids aqueous solution under the trade name "Sumirez Resin 650(30)" manufactured by Taoka Chemical Co., Ltd.). This resulted in a laminate X (linear polarizing plate) consisting of the first protective film / adhesive layer / polarizer / adhesive layer / second protective film. Here, when a laminate having a second protective film is used, the laminate X has a structure of first protective film / adhesive layer / polarizer / adhesive layer / second protective film / supporting substrate.

[0236] Next, a corona treatment was applied to the surface of the second protective film of the laminate X (if the laminate X has a supporting substrate, the surface after peeling off the supporting substrate) and the surface exposed by peeling off the substrate A of the retarder. The corona treatment device used was an AGF-B10 manufactured by Kasuga Electric Co., Ltd. The corona treatment was performed once using the corona treatment device under conditions of an output of 0.3 kW and a treatment speed of 3 m / min. The corona-treated surface of the laminate X and the corona-treated surface of the retarder were bonded together via the pressure-sensitive adhesive layer 1. Thereafter, the substrate B of the retarder was peeled off to obtain a laminate Y including, in this order, the first protective film / adhesive layer / polarizer / adhesive layer / second protective film / pressure-sensitive adhesive layer 1 / photo-alignment film A / retardation film A / adhesive layer inside the retarder / retardation film B / alignment film B. Finally, the pressure-sensitive adhesive layer 2 was laminated on the surface of the laminate Y on the side of the retardation film B to obtain an optical laminate. The obtained optical laminate was evaluated using a retardation measuring device (KOBRA-WPR, manufactured by Oji Scientific Instruments Co., Ltd.), and the in-plane retardation value and wavelength dispersion of the retarder were found to be Re(550)=140 nm and α=0.87, respectively.

[0237] Example 1 8, Reference example 9~ The following table shows the types of the first protective film, polarizer, second protective film, retarder, and pressure-sensitive adhesive layer (the pressure-sensitive adhesive layer laminated on the surface of the retarder opposite to the second protective film) used in Example 12 and Comparative Example 1. The following table also shows the results of evaluation of the amount of change in retardation and metal corrosion performed on each optical laminate.

[0238] [Table 1]

[0239] [Table 2]

[0240] From the results shown in Tables 1 and 2, it was found that when the moisture permeability of the second protective film is low and the pressure-sensitive adhesive layer contains a predetermined antistatic material, changes in retardation characteristics and metal corrosion are sufficiently suppressed (Examples 1 to 3). 8, Reference example 9~12 and Comparative Example 1). In addition, it was found that when the pressure-sensitive adhesive layer 1 was used as the pressure-sensitive adhesive layer in the retarder, the degree of inhibition of metal corrosion was slightly weakened (Example 7, Reference example 10,12) It was also found that the degree of metal corrosion inhibition was slightly weakened as the thickness of the second protective film increased ( reference Examples 9 to 12). It was also found that if the thickness of the second protective film was too thin, the degree of metal corrosion inhibition was slightly weakened (Examples 2 and 5). [Industrial Applicability]

[0241] The present invention can be used as a circular polarizer. [Explanation of symbols]

[0242] 1...optical laminate, 2...linear polarizer, 3...adhesive layer between linear polarizer and retarder, 4...retarder, 5...adhesive layer, 21...first protective film, 22...polarizer, 23...second protective film, 41...first retardation layer, 42...adhesive layer in retarder, 43...second retardation layer.

Claims

1. An optical laminate including a first protective film, a polarizer, a second protective film, a retarder, and a pressure-sensitive adhesive layer in this order, The moisture permeability of the second protective film is 1200 g / (m ２ ・day) or less, The thickness of the second protective film is 0.1 to 8 μm, the water vapor permeability coefficient of the retarder is 100 or less, the pressure-sensitive adhesive layer contains an antistatic agent, The antistatic agent comprises an ionic compound composed of an organic cation and an anion represented by the following formula (1): (C ｎ F ２ｎ＋１ SO ２ ) ２ N － …(1) (In the formula, n is an integer from 0 to 5.)

2. The optical laminate according to claim 1 , wherein the retarder comprises a first retardation layer, a pressure-sensitive adhesive layer, and a second retardation layer, and has a function as a λ / 4 plate over the entire visible light range.

3. The optical laminate according to claim 2 , wherein the adhesive layer is made of an active energy ray-curable adhesive.

4. The optical laminate according to claim 1 , wherein the second protective film is made of a cyclic polyolefin resin.

5. The moisture permeability of the first protective film is 100 g / (m ２ 2. The optical laminate according to claim 1, wherein the optical wavelength is 100 nm or more.

6. The optical laminate according to claim 1 , wherein the ionic compound comprises an organic cation containing a nitrogen atom.

7. The optical laminate according to any one of claims 1 to 6, and an image display panel to which the optical laminate is attached.

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