Optical laminate and method for manufacturing the same

Abstract

To provide an optical laminate having sufficient crack resistance under a heat shock environment while suppressing deformation defects.SOLUTION: The present invention relates to an optical laminate including a first protective layer, a first adhesive layer, and a first retardation film, in which the first protective layer and the first retardation film are bonded to each other via the first adhesive layer, and the first retardation film includes a first retardation layer without including a first alignment layer, or includes both the first retardation layer and the first alignment layer. The Martens hardness of a surface of the first retardation layer on the first protective layer side is at least 100 N / mm2 and the ratio of the Martens hardness of the surface on the side of the first protective layer in the first retardation layer to the Martens hardness of the first protective layer is at least 1.5.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an optical laminate and a method for producing an optical laminate. [Background technology]

[0002] A circular polarizing plate is an optical laminate in which a polarizing plate and a retardation film are laminated, and is used, for example, in devices that display images in a flat state, such as organic EL image display devices, to prevent light reflection from the electrodes that make up the device.

[0003] A circular polarizing plate can be produced, for example, by bonding a polarizing plate and a retardation film with an adhesive or the like, but minute foreign matter mixed in the adhesive or the like can cause deformation defects and unevenness in some cases. In order to solve such problems, Patent Document 1 considers suppressing the occurrence of unevenness caused by minute foreign matter by increasing the DMT elastic modulus of the retardation layer to a certain extent. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-152763 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the DMT elastic modulus of the retardation layer is increased to harden the retardation layer in order to suppress deformation defects, crack resistance under a heat shock environment may be insufficient. Therefore, the present invention aims to provide an optical laminate that suppresses deformation defects and has sufficient crack resistance even under a heat shock environment. Another object of the present invention is to provide a method for producing such an optical laminate. [Means for solving the problem]

[0006] Aspects of the present disclosure include, for example, the following [1] to

[17] . [1] A first protective layer, a first attachment layer, and a first retardation film, the first protective layer and the first retardation film are bonded to each other via the first bonding layer, The first retardation film includes a first retardation layer but does not include a first alignment layer, or includes a first retardation layer and a first alignment layer, The Martens hardness of the surface of the first retardation layer on the side of the first protective layer is 100 N / mm 2 That's all, An optical laminate, wherein the ratio of the Martens hardness of the surface of the first retardation layer on the first protective layer side to the Martens hardness of the first protective layer is 1.5 or more. [2] The optical laminate according to [1], wherein the first retardation layer is a cured product layer of a polymerizable liquid crystal compound. [3] The optical laminate according to [1] or [2], wherein the first retardation film includes the first retardation layer but does not include the first alignment layer. [4] The Martens hardness of the surface of the first retardation layer on the side of the first protective layer is 170 N / mm 2 The optical laminate according to any one of [1] to [3] above. [5] The Martens hardness of the surface of the first retardation layer on the side of the first protective layer is 250 N / mm 2 The optical laminate according to any one of [1] to [4] below. [6] The optical laminate according to any one of [1] to [5], wherein the Martens hardness of the surface of the first retardation layer on the first protective layer side is greater than the Martens hardness of the surface of the first retardation layer on the opposite side to the first protective layer. [7] The Martens hardness of the first protective layer is 80 N / mm 2 The optical laminate according to any one of [1] to [6] above. [8] The Martens hardness of the first protective layer is 140 N / mm 2 The optical laminate according to any one of [1] to [7] below. [9] The optical laminate according to any one of [1] to [8], wherein the first protective layer has a thickness direction retardation value Rth of 10 nm or more.

[10] The optical laminate according to any one of [1] to [9], wherein the ratio is 2.0 or more.

[11] The optical laminate according to any one of [1] to

[10] , wherein the ratio is 3.5 or less.

[12] The optical laminate according to any one of [1] to

[11] , further comprising a polarizer layer.

[13] Further comprising a second attachment layer and a second retardation film; the first retardation film and the second retardation film are bonded to each other via the second bonding layer, The optical laminate according to any one of [1] to

[12] , wherein the second retardation film includes a second retardation layer but does not include a second alignment layer, or includes a second retardation layer and a second alignment layer.

[14] The optical laminate according to

[13] , wherein the optical laminate including the first retardation film, the second attaching layer, and the second retardation film satisfies the relationships of the following formulas (1) and (2): 100≦Re(550)≦180 (1) Re(450) / Re(550)≦1.0 (2) [In formula (1) and formula (2), 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.

[15] The optical laminate according to

[13] or

[14] , wherein the second retardation film includes the second retardation layer but does not include the second alignment layer.

[16] The optical laminate according to any one of

[13] to

[15] , wherein the second attaching layer is a cured layer of an active energy ray-curable composition.

[17] A step of preparing a first retardation film including a first retardation layer and a first alignment layer; and providing a first protective layer on a surface of the first retardation layer side of the first retardation film via a first attachment layer to obtain a first optical laminate, The Martens hardness of the surface of the first retardation layer on the side of the first protective layer is 100 N / mm 2 That's all, A method for producing an optical laminate, wherein the ratio of the Martens hardness of the surface of the first retardation layer on the first protective layer side to the Martens hardness of the first protective layer is 1.5 or more. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an optical laminate that suppresses deformation defects and has sufficient crack resistance even under a heat shock environment. Furthermore, according to the present invention, it is possible to provide a method for producing such an optical laminate. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention is not limited to the following examples.

[0009] In this specification, numerical ranges indicated with "to" indicate a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. A numerical range "A or greater" means a range exceeding A and A. A numerical range "A or less" means a range less than A and A. In numerical ranges described in stages in this specification, the upper or lower limit of a certain numerical range can be arbitrarily combined with the upper or lower limit of a numerical range of another stage. In numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. "A or B" may include either A or B, or may include both. Unless otherwise specified, the materials exemplified in this specification can be used alone or in combination of two or more. When multiple substances corresponding to each component are present in the composition, the content of each component in the composition refers to the total amount of those multiple substances present in the composition, unless otherwise specified. In this specification, the term "(meth)acrylic resin" means either an acrylic resin or a methacrylic resin, and the "(meth)" in (meth)acrylate, etc. has the same meaning.

[0010] An optical laminate according to one embodiment of the present invention includes a first protective layer, a first attaching layer, and a first retardation film. In the optical laminate, the first protective layer and the first retardation film are attached via the first attaching layer. The first retardation film includes a first retardation layer but may not include a first alignment layer. The first retardation film may include a first retardation layer and a first alignment layer. The Martens hardness of the surface of the first retardation layer on the first protective layer side is 100 N / mm 2 As described above, the ratio of the Martens hardness of the surface of the first retardation layer on the first protective layer side to the Martens hardness of the first protective layer is 1.5 or more.

[0011] According to such an optical laminate, the Martens hardness of the surface of the first retardation layer on the first protective layer side is 100 N / mm 2As described above, when the ratio of the Martens hardness of the surface of the first protective layer side of the first retardation layer to the Martens hardness of the first protective layer is 1.5 or more, deformation defects can be suppressed while maintaining sufficient crack resistance even under a heat shock environment. The reason why such an effect is achieved is not necessarily clear, but the inventors speculate as follows. That is, first, when minute foreign matter is mixed into the first bonding layer, local deformation occurs in the first protective layer or the first retardation layer around the first bonding layer where the minute foreign matter is mixed, and this deformation defect of the first retardation layer may be visually recognized as unevenness in the optical laminate. However, when the Martens hardness of the first protective layer side of the first retardation layer is relatively high, even if minute foreign matter is mixed into the first bonding layer, the degree of deformation of the first retardation layer is reduced, making it possible to suppress unevenness in the optical laminate caused by deformation defects in the first retardation layer. Furthermore, when the ratio of the Martens hardness of the surface of the first retardation layer facing the first protective layer to the Martens hardness of the first protective layer is large, deformation of the first retardation layer when minute foreign matter is mixed into the first bonding layer is reduced, thereby suppressing deformation defects when the laminate is formed. Furthermore, when temperature changes occur in the usage environment of a display device in which an optical laminate is stacked, dimensional changes such as expansion and contraction occur in the retardation film, other optical films, and bonding layers constituting the optical laminate. This easily causes cracks when stress is applied to the thin films (e.g., alignment layer and retardation layer) constituting the laminate. However, when the ratio of the Martens hardness of the surface of the first retardation layer facing the first protective layer to the Martens hardness of the first protective layer is relatively large, the flexibility of the entire optical laminate is improved, thereby suppressing the occurrence of cracks due to deformation such as dimensional changes caused by a heat shock environment (severe temperature changes). In particular, the alignment layer has low fracture strength and is easily cracked when stress is applied. Therefore, a configuration that does not include an alignment film layer is more preferable because the layer that can be the starting point of cracks is eliminated, thereby suppressing the occurrence of cracks.

[0012] <First protective layer> The first protective layer has a function of protecting the surface of the linear polarizer described below. The linear polarizer and the first protective layer may be directly laminated to each other. Here, "directly laminated" includes an embodiment in which the first protective layer is laminated to the linear polarizer by the self-adhesive property of the first protective layer, and an embodiment in which the first protective layer is laminated via an adhesive layer or a pressure-sensitive adhesive layer. The first protective layer may be subjected to a surface treatment (for example, corona treatment) to improve adhesion to the linear polarizer, and may have a thin layer such as a primer layer (also referred to as an easy-adhesion layer) formed thereon.

[0013] The first protective layer can be, for example, a resin film (protective film) that exhibits excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and stretchability. The resin film may be a thermoplastic resin film. Specific examples of such resins include cellulose-based resins such as triacetyl cellulose; polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone-based resins; polysulfone-based resins; polycarbonate-based resins; polyamide-based resins such as nylon and aromatic polyamide; polyimide-based resins; polyolefin-based resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; cyclic polyolefin-based resins having cyclo- and norbornene structures (also known as norbornene-based resins); (meth)acrylic resins such as polymethyl methacrylate; polyarylate-based resins; polystyrene-based resins; polyvinyl alcohol-based resins; and mixtures thereof. Protective films made of such materials are readily available commercially.

[0014] The first protective layer may be a curable 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 curable 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 curable resin layer with a support substrate is attached to a linear polarizer, if necessary via a pressure-sensitive adhesive layer, and then the support substrate is peeled off and removed, thereby laminating the curable resin layer as a protective layer on the linear polarizer.

[0015] The ratio of the Martens hardness of the surface of the first retardation layer facing the first protective layer to the Martens hardness of the first protective layer is 1.5 or more, from the viewpoint of suppressing deformation defects and having sufficient crack resistance even under a heat shock environment. From the viewpoint of more easily suppressing deformation defects, this ratio is preferably 1.6 or more, more preferably 1.8 or more, and particularly preferably 2.0 or more. From the viewpoint of further improving crack resistance under a heat shock environment, this ratio is preferably 4.5 or less, more preferably 4.0 or less, even more preferably 3.5 or less, particularly preferably 3.0 or less, even more preferably 2.5 or less, and very preferably 2.2 or less. The Martens hardness can be measured by the method described in the Examples below.

[0016] The Martens hardness of the first protective layer is set to 50 N / mm 2 More than 80N / mm is preferable. 2 More preferably, 100N / mm 2 The Martens hardness of the first protective layer is particularly preferably 170 N / mm 2 Preferably less than 140N / mm 2 Less than 120N / mm is more preferable. 2The following is particularly preferred: 110 N / mm 2 The following is even more preferred:

[0017] The Martens hardness of the first protective layer can be adjusted by changing the material and formation method of the first protective layer, and in particular, by adjusting the molecular weight and degree of orientation of the resin forming the first protective layer, the Martens hardness of the first protective layer can be improved.

[0018] The retardation value Rth in the thickness direction of the first protective layer is preferably 10 nm or more, more preferably 15 nm or more, from the viewpoint of suppressing a change in the hue of reflected ambient light when viewed from an oblique direction, and may be 25 nm or less, or may be 20 nm or less.

[0019] The thickness of the first protective layer is preferably 0.1 μm to 60 μm, more preferably 0.5 μm to 40 μm, and even more preferably 1 μm to 30 μm.

[0020] A protective film can be produced by stretching a film containing the above-mentioned thermoplastic resin. 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 (TD) perpendicular to the machine direction (MD), and a direction oblique to the machine direction (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. Stretching can be performed, for example, by stretching the unstretched film in the longitudinal direction (machine direction: MD) using two or more pairs of nip rolls with a high peripheral speed at the outlet side, or by gripping both side edges of the unstretched film with chucks and spreading it in the direction perpendicular to the machine direction (TD). The retardation value and wavelength dispersion can be controlled by adjusting the film thickness or the stretch ratio. Furthermore, the wavelength dispersion value can be controlled by adding a wavelength dispersion adjuster to the resin.

[0021] The first protective layer 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.

[0022] A coating layer (surface treatment layer) can be provided on the outer surface of the first protective layer to impart desired surface optical properties or other characteristics. 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 layer.

[0023] The hard coat layer has the function of increasing the surface hardness of the first protective layer 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 an optical film having a hard coat layer on a glass plate).

[0024] The material 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 preferred as the material forming the hard coat layer because they have good adhesion to the first protective layer and are highly productive.

[0025] 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 an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a leveling agent, and an antifoaming agent.

[0026] The hard coat layer may contain an additive to further improve its strength. The additive is not particularly limited, and examples thereof include inorganic fine particles, organic fine particles, and mixtures thereof. The thickness of the hard coat layer may be 1 μm to 20 μm, or 2 μm to 10 μm, from the viewpoint of providing sufficient hardness and preventing cracking when cut. The thickness of the hard coat layer is preferably 3 μm to 7 μm.

[0027] The antiglare layer is a layer having a finely uneven surface, and is preferably formed using the above-mentioned hard coat material.

[0028] An antiglare layer having a finely textured surface can be formed by a method in which a coating film containing fine particles is formed on a stretched film and then the coating film is provided with textured surfaces based on the fine particles; or a method in which a coating film containing fine particles or not containing fine particles is formed on a stretched film and then the film is pressed against a mold (such as a roll) that has been given a textured surface to transfer the textured surface (also called an embossing method).

[0029] The antireflection layer is a layer that weakens the reflection of external light from the surface of the first protective layer for a person observing the first protective layer, and may have a reflectance of 1.5% or less for visible light. An antireflection layer with such a reflectance can be obtained 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 each other, thereby achieving excellent antireflection function.

[0030] 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, since this makes the process extremely simple. 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.

[0031] A coating composition capable of forming a high refractive index layer (a composition for forming a high refractive index layer) is prepared by dissolving, for example, a curable resin such as urethane acrylate and an 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 coating properties, the coating composition may contain a leveling agent, preferably a fluorine-based leveling agent.

[0032] Furthermore, a coating composition capable of forming a low refractive index layer (a composition for forming a low refractive index layer) is prepared by dispersing silica particles in a solution obtained by dissolving a binder resin such as polyethylene glycol diacrylate or pentaerythritol (tri / tetra)acrylate as a curable resin in an initiator (photopolymerization initiator) such as acetophenone, benzophenone, benzyl dimethyl ketal, α-hydroxyalkylphenone, α-aminoalkylphenone, or thioxanthone in a solvent such as 1-methoxy-2-propyl acetate or methyl isobutyl. To improve coatability, the coating composition may contain a fluorine-based leveling agent.

[0033] The coating compositions capable of forming the high refractive index layer and the low refractive index layer listed here are just examples, and it is preferable to optimize the composition for forming the high refractive index layer and the composition for forming the low refractive index layer, respectively, depending on the properties of the antireflection layer to be formed.

[0034] 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 first protective layer and the low refractive index layer.

[0035] 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.

[0036] The antistatic layer is provided for the purpose of imparting conductivity to the surface of the first protective layer and suppressing the effects of static electricity. For example, a method of applying a resin composition containing a conductive substance (antistatic agent) onto the first protective layer can be used to form the antistatic layer. For example, an antistatic hard coat layer can be formed by adding an antistatic agent to the hard coat material used to form the hard coat layer.

[0037] 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. The antifouling layer can be formed by physical vapor deposition methods such as vapor deposition and sputtering, chemical vapor deposition methods, wet coating methods, etc., depending on the material to be formed. The average thickness of the antifouling layer may be about 1 to 50 nm, and preferably 3 to 35 nm.

[0038] <First lamination layer> The first attaching layer is suitably used when attaching the optical laminate to another adherend. The first attaching layer may be a pressure-sensitive adhesive layer (for example, a pressure-sensitive adhesive layer) or an adhesive layer. From the viewpoint of crack resistance, the first attaching layer is preferably a cured layer of an active energy ray-curable composition (active energy ray-curable pressure-sensitive adhesive composition, active energy ray-curable adhesive composition), and more preferably a cured product of an active energy ray-curable adhesive composition.

[0039] (Adhesive layer) As the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer, any conventionally known pressure-sensitive adhesive composition having excellent optical transparency can be used without particular limitation, and for example, a pressure-sensitive adhesive composition having a base polymer such as an acrylic resin, a urethane resin, a silicone resin, or a polyvinyl ether resin can be used. Alternatively, an active energy ray-curable pressure-sensitive adhesive composition or a heat-curable pressure-sensitive adhesive composition may be used. Among these, a pressure-sensitive adhesive composition having an acrylic resin as a base polymer, which is excellent in transparency, adhesive strength, removability, weather resistance, heat resistance, etc., is preferred.

[0040] The pressure-sensitive adhesive composition may further contain a crosslinking agent, a silane compound, an antistatic agent, and the like.

[0041] [(Meth)acrylic resin] The (meth)acrylic resin contained in the pressure-sensitive adhesive composition is preferably a polymer (hereinafter also referred to as a "(meth)acrylic acid ester polymer") having as its main component (for example, containing 50 parts by mass or more of the structural unit (I) derived from a (meth)acrylic acid alkyl ester represented by the following formula (I) (hereinafter also referred to as a "structural unit (I)"), per 100 parts by mass of the structural unit of the (meth)acrylic resin:

[0042] [ka] [In the formula, R 10 represents a hydrogen atom or a methyl group, and R 20 represents an alkyl group having 1 to 20 carbon atoms, and the alkyl group may have any of a linear, branched, or cyclic structure, and a hydrogen atom of the alkyl group may be substituted with an alkoxy group having 1 to 10 carbon atoms.

[0043] Examples of the (meth)acrylic acid ester represented by formula (I) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, i-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n- Examples of the alkoxy group-containing alkyl acrylate include 2-methoxyethyl (meth)acrylate and ethoxymethyl (meth)acrylate. Examples of the alkoxy group-containing alkyl acrylate include 2-methoxyethyl (meth)acrylate and ethoxymethyl (meth)acrylate. Examples of the alkoxy group-containing alkyl acrylate include 2-methoxyethyl (meth)acrylate and ethoxymethyl (meth)acrylate. Examples of the alkoxy group-containing alkyl acrylate include 2-ethylhexyl (meth)acrylate and 2-ethylhexyl (meth)acrylate, and particularly preferably n-butyl (meth)acrylate.

[0044] The (meth)acrylic acid ester polymer may contain a structural unit derived from a monomer other than the structural unit (I). The structural unit derived from the other monomer may be one type or two or more types. Examples of the other monomer that the (meth)acrylic acid ester polymer may contain include a monomer having a polar functional group, a monomer having an aromatic group, and an acrylamide-based monomer.

[0045] 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.

[0046] The content of structural units derived from monomers having polar functional groups in the (meth)acrylic acid ester polymer is preferably 10 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less, even more preferably 0.5 parts by mass or more and 5 parts by mass or less, and particularly preferably 1 part by mass or more and 5 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylic acid ester polymer.

[0047] 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.

[0048] The content of structural units derived from monomers having an aromatic group in the (meth)acrylic acid ester polymer is preferably 20 parts by mass or less, more preferably 4 parts by mass or more and 20 parts by mass or less, and even more preferably 4 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylic acid ester polymer.

[0049] Examples of acrylamide monomers include N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, N-(2-methylpropoxymethyl)acrylamide, etc. By including these structural units, it is possible to suppress the bleeding out of additives such as antistatic agents, which will be described later.

[0050] The structural unit derived from a monomer other than the structural unit (I) may include a structural unit derived from a styrene-based monomer, a structural unit derived from a vinyl-based monomer, a structural unit derived from a monomer having multiple (meth)acryloyl groups in the molecule, and the like.

[0051] The weight-average molecular weight (hereinafter also simply referred to as "Mw") of the (meth)acrylic resin (1) is preferably 500,000 to 2,500,000. A weight-average molecular weight of 500,000 or more can improve the durability of the first pressure-sensitive adhesive layer in high-temperature, high-humidity environments. A weight-average molecular weight of 2,500,000 or less improves operability when applying a coating liquid containing the pressure-sensitive adhesive composition. The molecular weight distribution (Mw / Mn), expressed as the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (hereinafter also simply referred to as "Mn"), may be 2 to 10. In this specification, the terms "weight-average molecular weight" and "number-average molecular weight" are polystyrene-equivalent values ​​measured by gel permeation chromatography (GPC).

[0052] When the (meth)acrylic resin is dissolved in ethyl acetate to form a 20% by mass solution, the viscosity at 25°C is preferably 20 Pa·s or less, and more preferably 0.1 to 15 Pa·s. When the viscosity of the (meth)acrylic resin at 25°C is within this range, it contributes to improved durability and reworkability of a polarizing plate including a pressure-sensitive adhesive layer formed from the resin. The viscosity can be measured using a Brookfield viscometer.

[0053] The glass transition temperature (Tg) of the (meth)acrylic resin is, for example, −60 to 20° C., preferably −50 to 15° C., more preferably −45 to 10° C., and still more preferably −40 to 0° C. The glass transition temperature can be measured by a differential scanning calorimeter (DSC).

[0054] The (meth)acrylic resin may contain two or more types of (meth)acrylic acid ester polymers. Examples of such (meth)acrylic acid ester polymers include (meth)acrylic acid ester polymers having a relatively low molecular weight, such as those containing the structural unit (I) derived from the (meth)acrylic acid ester as the main component, and having a weight-average molecular weight in the range of 50,000 to 300,000.

[0055] The (meth)acrylic resin can be produced by known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. In producing the (meth)acrylic resin, for example, polymerization is carried out in the presence of a polymerization initiator. The amount of the polymerization initiator used may be 0.001 to 5 parts by mass per 100 parts by mass of the total of all monomers constituting the (meth)acrylic resin. The (meth)acrylic resin can also be produced by a method of polymerization using active energy rays such as ultraviolet rays.

[0056] [Crosslinking agent] The pressure-sensitive adhesive composition preferably contains a crosslinking agent, such as a conventional crosslinking agent (e.g., an isocyanate compound, an epoxy compound, an aziridine compound, a metal chelate compound, a peroxide, etc.), and is preferably an isocyanate compound from the viewpoints of the pot life of the pressure-sensitive adhesive composition, the crosslinking rate, and the durability of the polarizing plate.

[0057] 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.

[0058] The proportion of the crosslinking agent relative to 100 parts by mass of the (meth)acrylic resin is, for example, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 1 part by mass.

[0059] [Silane compounds] The pressure-sensitive adhesive composition may further contain a silane compound.

[0060] 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.

[0061] The silane compound may also contain an oligomer derived from the above silane compound.

[0062] The content of the silane compound in the pressure-sensitive adhesive composition may be 0.01 to 10 parts by mass, and preferably 0.05 to 5 parts by mass, relative to 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.

[0063] [Antistatic agent] The pressure-sensitive adhesive composition may further contain an antistatic agent. Examples of the antistatic agent include known agents, with ionic antistatic agents being preferred. Examples of the cationic component constituting the ionic antistatic agent include organic cations and inorganic cations. Examples of organic cations include pyridinium cation, imidazolium cation, ammonium cation, sulfonium cation, and phosphonium cation. Examples of inorganic cations include alkali metal cations such as lithium cation, potassium cation, sodium cation, and cesium cation, and alkaline earth metal cations such as magnesium cation and calcium cation. Examples of the anionic component constituting the ionic antistatic agent include inorganic and organic anions, but an anionic component containing a fluorine atom is preferred because of its excellent antistatic properties. Examples of the anionic component containing a fluorine atom include hexafluorophosphate anion (PF6 - ), bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N - ], bis(fluorosulfonyl)imide anion [(FSO2)2N - ] anions and the like.

[0064] Ionic antistatic agents that are solid at room temperature are preferred in that they provide excellent stability over time of the antistatic performance of the pressure-sensitive adhesive composition.

[0065] The content of the antistatic agent is, for example, 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, and more preferably 1 to 7 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin.

[0066] 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.

[0067] The pressure-sensitive adhesive layer can be formed, for example, by dissolving or dispersing the pressure-sensitive adhesive composition in a solvent to prepare a solvent-containing pressure-sensitive adhesive composition, which is then applied to the surface of the layer on which the pressure-sensitive adhesive layer is to be formed, and drying.

[0068] The thickness of the pressure-sensitive adhesive layer may be 0.1 to 30 μm, preferably 3 to 30 μm, and more preferably 5 to 25 μm.

[0069] (adhesive layer) The adhesive layer may be formed from an adhesive composition.

[0070] Examples of adhesive compositions include aqueous adhesive compositions and curable adhesive compositions that cure upon heating or irradiation with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays. Examples of aqueous adhesive compositions include those in which a polyvinyl alcohol resin or a urethane resin is dissolved in water as the main component, and those in which a polyvinyl alcohol resin or a urethane resin is dispersed in water as the main component. The aqueous adhesive composition may further contain a curable component or crosslinking agent such as a polyaldehyde, a melamine compound, a zirconia compound, a zinc compound, a glyoxal compound, or a water-soluble epoxy resin. Examples of aqueous adhesive compositions include the adhesive composition described in JP 2010-191389 A, the adhesive composition described in JP 2011-107686 A, the composition described in JP 2020-172088 A, and the composition described in JP 2005-208456 A.

[0071] 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.

[0072] The cationically polymerizable compound is a compound or oligomer that undergoes a cationic polymerization reaction and hardens when exposed to active energy rays such as ultraviolet light, visible light, electron beams, or X-rays or when heated. Specific examples of the cationically polymerizable compound include epoxy compounds, oxetane compounds, and vinyl compounds.

[0073] 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.

[0074] 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.

[0075] 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 may be 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.

[0076] Examples of cationic polymerization adhesive compositions include the cationic polymerization compositions described in JP 2016-126345 A, WO 2019 / 10315 A, and JP 2021-113969 A.

[0077] 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.

[0078] Examples of the (meth)acrylic compound include (meth)acrylate monomers and (meth)acrylamide monomers each having at least one (meth)acryloyloxy group in the molecule, and (meth)acryl group-containing compounds such as (meth)acrylic oligomers obtained by reacting two or more functional group-containing compounds and each having at least two (meth)acryloyl groups in the molecule. In this specification, (meth)acryloyl means either acryloyl or methacryloyl.

[0079] 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 may be 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.

[0080] 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.

[0081] 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.

[0082] The adhesive composition and adhesive layer preferably contain a silicone-based or fluorine-based leveling agent as described in the section on the first retardation layer. The content of the leveling agent in the adhesive composition and adhesive layer is preferably 0.001 to 2 parts by mass, more preferably 0.01 to 1.5 parts by mass, and even more preferably 0.1 to 1.5 parts by mass, per 100 parts by mass of the solid content.

[0083] The first retardation layer and the second retardation layer are bonded to each other with an adhesive layer by applying an adhesive composition to at least one of the bonding surfaces selected from the bonding surface of the first retardation layer and the bonding surface of the second retardation layer, overlaying the two layers with the coating layer of the adhesive composition interposed therebetween, pressing them together from above and below using a laminating roll or the like, and then drying the adhesive layer, curing it by irradiating it with active energy rays, or curing it by heating.

[0084] Before forming the coating layer of the adhesive layer, at least one of the bonding surfaces selected from the bonding surface of the first retardation layer and the bonding surface of the second retardation layer may be subjected to an easy-adhesion treatment such as a saponification treatment, a corona treatment, a plasma treatment, a primer treatment, or an anchor coating treatment.

[0085] To form a coating layer of the adhesive composition, various coating methods can be used, such as a die coater, a comma coater, a gravure coater, a wire bar coater, or a doctor blade coater.

[0086] 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 1000mJ / cm 2 It is more preferable to set the following:

[0087] 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.

[0088] 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.

[0089] The thickness of the adhesive layer formed from the active energy ray-curable adhesive composition may be, for example, 10 μm or less, preferably 5 μm or less, and more preferably 3 μm or less, or may be 0.1 μm or more, preferably 0.5 μm or more, and more preferably 1 μm or more.

[0090] <First retardation film> The first retardation film includes a layer (first retardation layer) that exhibits retardation. The first retardation layer may be a film formed by stretching a thermoplastic resin film or an optically anisotropic layer (hereinafter also referred to as a "retardation film") made of an oriented polymer of a polymerizable liquid crystal compound.

[0091] (first retardation layer) The first retardation layer is a layer of a cured product of an aligned polymerizable liquid crystal compound, and exhibits retardation.

[0092] The first retardation layer is not limited as long as it is a layer that exhibits retardation in any direction, and may be a retardation layer that generates an in-plane retardation such as a positive A plate or a negative A plate, or may be a retardation layer that generates a retardation in the thickness direction such as a positive C plate or a negative C plate. The positive A plate and the negative A plate may each be a λ / 4 plate or a λ / 2 plate. The first retardation layer may have a tilt alignment or may form a cholesteric alignment state.

[0093] The first retardation layer may be a single liquid crystal retardation layer or a laminate of a plurality of liquid crystal retardation layers.

[0094] The first retardation layer may have a normal wavelength dispersion property or a reverse wavelength dispersion property.

[0095] The first retardation layer film is, for example, a film in which a polymerizable liquid crystal compound is hardened in an oriented state, and in order to generate a retardation in the viewing surface, it is necessary for the first retardation layer film to be a hardened film in which the polymerizable group is polymerized in a state in which the polymerizable liquid crystal compound is oriented horizontally relative to the substrate surface.

[0096] When the polymerizable liquid crystal compound is a rod-shaped liquid crystal, a positive A plate may be used, and when the polymerizable liquid crystal compound is a disc-shaped liquid crystal, a negative A plate may be used.

[0097] The optical laminate according to one embodiment may further include a second bonding layer and a second retardation layer described later, and the first retardation film and the second retardation layer may be bonded together via the second bonding layer.

[0098] In order to achieve a high level of anti-reflection function, it is preferable that the first retardation layer has a λ / 4 plate function (i.e., a π / 2 retardation function) over the entire visible light range. Furthermore, in order to achieve a high level of anti-reflection function, it is preferable that the laminate of the first retardation layer and the second retardation layer has a λ / 4 plate function (i.e., a π / 2 retardation function) over the entire visible light range. Specifically, a reverse wavelength dispersion λ / 4 layer is preferred, or it is preferable to combine two or more retardation films with different orientations. For example, a combination of a retardation film having a λ / 2 plate function (i.e., a π retardation function) as the first retardation layer and a retardation film having a λ / 4 plate function (i.e., a π / 2 retardation function) as the second retardation layer may be used.

[0099] In addition, from the viewpoint of compensating for the anti-reflection function in oblique directions, a layer having anisotropy in the thickness direction (positive C plate) may be included as a third retardation layer described later. Furthermore, the retardation layers may each independently have a tilt alignment or may form a cholesteric alignment state.

[0100] Hereinafter, as an example of the first retardation layer and the laminate of the first retardation layer and the second retardation layer, a laminate of a reverse wavelength dispersion λ / 4 plate, a positive wavelength dispersion λ / 4 plate and a positive wavelength dispersion λ / 2 plate, and a positive C plate will be described.

[0101] <Reverse wavelength dispersion λ / 4 plate> The reverse wavelength dispersion λ / 4 plate preferably satisfies the optical properties represented by the following formulas (R1) and (R2), where Re(λ) is the in-plane retardation value for light with a wavelength of λ nm, and more preferably satisfies the optical properties represented by the following formulas (R1), (R2), and (R3):

[0102] 100nm <Re(550)<160nm …(R1) (In the formula, Re(550) represents the in-plane phase difference value (in-plane retardation) for light with a wavelength of 550 nm.) Re(450) / Re(550)≦1.0 …(R2) 1.00≦Re(650) / Re(550) …(R3) (In the formula, Re(450) represents the in-plane retardation value (unit: nm) for light with a wavelength of 450 nm, Re(550) represents the in-plane retardation value (unit: nm) for light with a wavelength of 550 nm, and Re(650) represents the in-plane retardation value (unit: nm) for light with a wavelength of 650 nm.) When the "Re(450) / Re(550)" of the liquid crystal retardation film exceeds 1.0, light leakage on the short wavelength side of a circular polarizer (elliptically polarizer) equipped with the liquid crystal retardation film increases. The ratio is preferably 0.7 to 1.0, more preferably 0.80 to 0.95, even more preferably 0.80 to 0.92, and particularly preferably 0.82 to 0.88.

[0103] The value of "Re(450) / Re(550)" can be adjusted arbitrarily by adjusting the mixing ratio of the polymerizable liquid crystal compound, the lamination angle of the plurality of optically anisotropic layers, and the retardation value.

[0104] The in-plane retardation value of the retardation film can be adjusted by the thickness of the retardation film. Since the in-plane retardation value is determined by the following formula (4), a desired in-plane retardation value (Re(λ)) can be obtained by adjusting Δn(λ) and the film thickness d. The thickness of the retardation film is preferably 0.5 μm to 5 μm, more preferably 1 μm to 3 μm. The thickness of the retardation film can be measured using an interference film thickness meter, a laser microscope, or a stylus film thickness meter. Δn(λ) depends on the molecular structure of the polymerizable liquid crystal compound, which will be described later.

[0105] Re(λ)=d×Δn(λ) …(4) (In the formula, Re(λ) represents the in-plane retardation value (nm) at a wavelength of λ nm, d represents the film thickness, and Δn(λ) represents the birefringence at a wavelength of λ nm.)

[0106] <Positive C Plate> There are no particular limitations on the positive C plate as long as it has anisotropy in the thickness direction, but if it does not have tilt alignment or cholesteric alignment, it has optical properties expressed by formula (PC3). nx≒ny <nz (PC3)

[0107] The in-plane retardation value Re(550) of the positive C plate at a wavelength of 550 nm may be in the range of 0 to 10 nm, preferably in the range of 0 to 5 nm. Furthermore, the retardation value Rth(550) in the thickness direction at a wavelength of 550 nm may be in the range of −170 nm or more to −10 nm or less, preferably −150 nm or more to −20 nm or less, and more preferably −100 nm or more to −40 nm or less. When the retardation value in the thickness direction is in this range, the anti-reflection properties from oblique directions can be further improved.

[0108] When the positive C plate is a stretched film, its thickness may be 300 μm or less, preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less.When the positive C plate is a coating layer formed by polymerizing a polymerizable liquid crystal, its thickness may be 10 μm or less, preferably 5 μm or less, and more preferably 0.3 μm or more and 3 μm or less.

[0109] The positive C plate is preferably a coating layer formed by polymerizing one or more polymerizable liquid crystal compounds, more preferably rod-shaped polymerizable liquid crystal compounds.

[0110] The first retardation layer is preferably formed by applying a composition containing a polymerizable liquid crystal compound (hereinafter also referred to as "first retardation layer-forming composition") onto a transparent substrate to form an optically anisotropic layer (hereinafter also referred to as "retardation film") made of an oriented polymer of the polymerizable liquid crystal compound, in terms of being able to reduce the thickness and arbitrarily design wavelength dispersion characteristics.

[0111] The first retardation layer is formed, for example, by applying a first retardation layer-forming composition containing a polymerizable liquid crystal compound onto an alignment film formed on a substrate, and polymerizing and curing the polymerizable liquid crystal compound contained in the first retardation layer film composition in an aligned state.

[0112] When each optically anisotropic film is a stretched film, its thickness may be 300 μm or less, preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less. When the optically anisotropic film is a layer formed by polymerizing a polymerizable liquid crystal, its first retardation layer may have a thickness of 10 μm or less, preferably 5 μm or less, more preferably 0.3 μm or more and 3 μm or less.

[0113] [First retardation layer forming composition] (Polymerizable liquid crystal compound) The polymerizable liquid crystal compound contained in the polymerizable liquid crystal 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 for forming the reverse wavelength dispersion λ / 4 plate. The photopolymerizable group refers to a reactive species generated from a photopolymerization initiator, such as a group that can participate in a polymerization reaction with an active radical or acid. 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 may be either thermotropic or lyotropic, but thermotropic liquid crystals are preferred due to their ability to precisely control the film thickness. The thermotropic liquid crystal may have a nematic or smectic phase structure. The polymerizable liquid crystal compound may be either rod-shaped or discotic. The polymerizable liquid crystal compound may be used alone or in combination.

[0114] 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 a 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):

[0115] [ka] Examples of the compound include compounds represented by the following formula:

[0116] 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-.

[0117] G1 and G2 each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein a hydrogen atom contained in the divalent aromatic group or the 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 the divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom.

[0118] L 1 , L 2 , B 1 and B 2 are each independently a single bond or a divalent linking group.

[0119] 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.

[0120] E 1 and E 2each 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 multiple -O-, -S-, or -COO-, they are not adjacent to each other. P1 and P2 each independently represent a polymerizable group or a hydrogen atom, and at least one is a polymerizable group.

[0121] 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 halogen atoms and alkyl groups having 1 to 4 carbon atoms, or a 1,4-cyclohexanediyl group optionally substituted with at least one substituent selected from the group consisting of halogen atoms and alkyl groups having 1 to 4 carbon atoms, more preferably a 1,4-phenylenediyl group substituted with a methyl group, an unsubstituted 1,4-phenylenediyl group, or an unsubstituted 1,4-trans-cyclohexanediyl group, and particularly preferably an unsubstituted 1,4-phenylenediyl group or an unsubstituted 1,4-trans-cyclohexanediyl group.

[0122] Multiple Gs 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.

[0123] 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=OORa8 -, -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-.

[0124] 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 a14-1Each 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-.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] In formula (I), the total number Nπ of π electrons contained in the divalent aromatic group represented by Ar is 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.

[0130] Suitable examples of the aromatic group represented by Ar include the following groups:

[0131] [ka]

[0132] In formulas (Ar-1) to (Ar-23), * represents a linking portion, and Z 0 , Z 1 and Z 2each 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.

[0133] Q 1 , and Q 2 are each independently -CR 2’ R 3’ -, -S-, -NH-, -NR 2’ represents -, -CO- or O-; R 2’ and R 3’ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0134] J 1 , and J 2 each independently represents a carbon atom or a nitrogen atom.

[0135] Y 1 , and Y 2 each independently represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group.

[0136] 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.

[0137] Y 1 , and Y 2Examples 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.

[0138] Y 1 , and Y 2 may each independently be an optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group. The polycyclic aromatic hydrocarbon group refers to a fused polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. The polycyclic aromatic heterocyclic group refers to a fused polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

[0139] Z 0 , Z 1 and Z 2 are each independently preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms, and Z 0 is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, and Z 1 and Z 2 is more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.

[0140] Q 1 , and Q 2 -NH-, -S-, -NR 2’ -, -O- are preferred, and R 2’ is preferably a hydrogen atom, and among these, -S-, -O-, and -NH- are particularly preferred.

[0141] Among the formulae (Ar-1) to (Ar-23), the formulae (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability.

[0142] 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.

[0143] Among polymerizable liquid crystal compounds, compounds with a maximum absorption wavelength of 300 to 400 nm are preferred. When a polymerizable liquid crystal composition contains a photopolymerization initiator, the polymerization reaction and gelation of the polymerizable liquid crystal compound may progress during long-term storage. However, if the polymerizable liquid crystal compound has a maximum absorption wavelength of 300 to 400 nm, even if the composition is exposed to ultraviolet light during storage, the generation of reactive species from the photopolymerization initiator and the progression of the polymerization reaction and gelation of the polymerizable liquid crystal compound due to the reactive species can be effectively suppressed. This is advantageous in terms of long-term stability of the polymerizable liquid crystal composition and can improve the alignment and film thickness uniformity of the resulting cured liquid crystal film. The maximum absorption wavelength of the polymerizable liquid crystal compound can be measured using a UV-visible spectrophotometer in a solvent. The solvent can be a solvent capable of dissolving the polymerizable liquid crystal compound, such as chloroform.

[0144] The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass, relative to 100 parts by mass of the solid content of the polymerizable liquid crystal composition. A content of the polymerizable liquid crystal compound within the above range is advantageous from the viewpoint of the alignment of the resulting cured liquid crystal film. In this specification, the solid content of the polymerizable liquid crystal composition refers to all components of the polymerizable liquid crystal composition excluding volatile components such as organic solvents.

[0145] [Laminate containing a positive wavelength dispersive λ / 2 plate and a positive wavelength dispersive λ / 4 plate] One method for achieving anti-reflection performance is to laminate a first retardation layer and a second retardation layer, and for example, a laminate combining a positive wavelength dispersion λ / 2 plate and a positive wavelength dispersion λ / 4 plate is known. One example of the laminate is obtained by combining a layer having the optical properties represented by formulas (Q1), (Q3), and (Q4) with a layer having the optical properties represented by formulas (Q2), (Q3), and (Q4) in a specific slow axis relationship.

[0146] 100nm <Re(550)<160nm (Q1) 200nm <Re(550)<320nm (Q2) Re(450) / Re(550)≧1.00 (Q3) 1.00≧Re(650) / Re(550) (Q4)

[0147] Methods for combining the above configurations include well-known methods such as those described in JP 2015-163935 A and WO 2013 / 137464 A. From the viewpoint of viewing angle compensation, it is preferable to use a λ / 2 layer containing a polymer of a discotic polymerizable liquid crystal compound and a λ / 4 layer containing a polymer of a rod-shaped polymerizable liquid crystal compound.

[0148] The laminate of the first retardation layer and the second retardation layer may be a laminate in which at least one liquid crystal retardation layer has a tilt orientation or a cholesteric orientation, in addition to the configuration in which the positive wavelength dispersion λ / 2 layer and the positive wavelength dispersion λ / 4 layer are combined, for example, WO 2021 / 060378, WO 2021 / 132616, WO 2021 / 132624, etc. are well-known configurations.

[0149] In the case of a laminate other than a laminate in which a positive wavelength dispersion λ / 2 plate and a positive wavelength dispersion λ / 4 plate are combined, it is preferable that the laminate of the first retardation layer, the first bonding layer bonding the first retardation layer and the second retardation layer, and the second retardation layer satisfy the relationships of the following formulas (1) and (2). 100≦Re(550)≦180 (1) Re(450) / Re(550)≦1.00 (2) [In formula (1) and formula (2), Re(450) represents the in-plane retardation value (nm) for light with a wavelength of 450 nm, Re(550) represents the in-plane retardation value (nm) for light with a wavelength of 550 nm.

[0150] The in-plane retardation value of the laminate (retardation film) is a value measured by laminating a polarizing plate on the laminate via an adhesive layer, in a state of polarizing plate / adhesive layer / first retardation layer / first adhesive layer / second retardation layer, using a measuring instrument such as KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. The polarizing plate and adhesive layer may be the polarizing plate and adhesive layer described below and the above-mentioned adhesive layer.

[0151] The first and second retardation layers may be the same liquid crystal retardation layer, or may be a combination of different types.

[0152] For example, one of the first retardation layer and the second retardation layer may be a reverse wavelength dispersion λ / 4 plate, and the other of the first retardation layer and the second retardation layer may be a positive C plate.

[0153] Examples of the discotic polymerizable liquid crystal compound include a compound containing a group represented by formula (W) (hereinafter, sometimes referred to as polymerizable liquid crystal compound (C)). [ka] [In formula (W), R 40 represents the following formulas (W-1) to (W-5).

[0154] [ka]

[0155] X 40 and Z 40 represents an alkanediyl group having 1 to 12 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and a hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. In addition, -CH2- constituting the alkanediyl group may be substituted with -O- or CO-. In addition, m 2 is an integer between 1 and 20.

[0156] Examples of the rod-shaped polymerizable liquid crystal compound include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V) or formula (VI). P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III) P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV) P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V) P11-B11-E11-B12-A11-B13-A12-F11 (VI) A11 represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. A hydrogen atom contained in the divalent alicyclic hydrocarbon group 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.

[0157] B11 is -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR 16 -, -NR 16 R represents -CO-, -CO-, -CS- or a single bond. 16 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0158] B12 and B13 each independently represent -C≡C-, -CH=CH-, -CH2-CH2-, -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)-, -OC(=O)-O-, -CH=N-, -N=CH-, -N=N-, or -C(=O)-NR 16 -, -NR 16 represents -C(=O)-, -OCH2-, -OCF2-, -CH2O-, -CF2O-, -CH=CH-C(=O)-O-, -OC(=O)-CH=CH- or a single bond.

[0159] E11 represents an alkanediyl group having 1 to 12 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and a hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. In addition, -CH2- constituting the alkanediyl group may be substituted with -O- or -CO-.]

[0160] The number of carbon atoms in the aromatic hydrocarbon group and alicyclic hydrocarbon group of A11 is preferably in the range of 3 to 18, more preferably in the range of 5 to 12, and particularly preferably 5 or 6. A11 is preferably a cyclohexane-1,4-diyl group or a 1,4-phenylene group.

[0161] E11 is preferably a linear alkanediyl group having 1 to 12 carbon atoms. -CH2- constituting the alkanediyl group may be replaced with -O-.

[0162] Specific examples include linear alkanediyl groups having 1 to 12 carbon atoms, such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; -CH-CH-O-CH-CH-, -CH-CH-O-CH-CH-O-CH-CH-, and CH-CH-O-CH-CH-O-CH-CH-O-CH-CH-.

[0163] As B11, -O-, -S-, -CO-O-, and -O-CO- are preferred, and among these, -CO-O- is more preferred.

[0164] B12 and B13 are each independently preferably -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)- or -OC(=O)-O-, and among these, -O- or OC(=O)-O- is more preferred.

[0165] The polymerizable group represented by P11 is preferably a radically polymerizable group or a cationically polymerizable group in terms of high polymerization reactivity, particularly high photopolymerization reactivity. In addition, the polymerizable group is preferably a group represented by the following formulas (P-11) to (P-15), because they are easy to handle and the liquid crystal compound itself is easy to produce.

[0166] [ka] [In formulas (P-11) to (P-15), R 17 ~R 21 each independently represents an alkyl group having 1 to 6 carbon atoms or a hydrogen atom.

[0167] Specific examples of the groups represented by formulae (P-11) to (P-15) include groups represented by the following formulae (P-16) to (P-20).

[0168] [ka]

[0169] P11 is preferably a group represented by formula (P-14) to formula (P-20), and more preferably a vinyl group, a p-stilbene group, an epoxy group or an oxetanyl group.

[0170] The group represented by P11-B11- is more preferably an acryloyloxy group or a methacryloyloxy group.

[0171] In the formula, A12 to A14 each independently have the same meaning as A11, B14 to B16 each independently have the same meaning as B12, B17 has the same meaning as B11, and E12 has the same meaning as E11. F11 represents a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group (—SOH), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and —CH2— constituting the alkyl group and alkoxy group may be replaced with —O—.

[0172] The content of the polymerizable liquid crystal compound in the composition for forming the first retardation layer is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass, relative to 100 parts by mass of the solid content of the composition for forming the first retardation layer. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of the alignment of the obtained first retardation layer. In this specification, the solid content of the composition for forming the first retardation layer means all components excluding volatile components such as organic solvents from the polymerizable liquid crystal composition.

[0173] The composition for forming the first retardation layer may further contain reactive additives such as a solvent, a leveling agent, a polymerization initiator, a photosensitizer, a polymerization inhibitor, a crosslinking agent, and an adhesive, in addition to the above-mentioned polymerizable liquid crystal compound. It is preferable to contain a solvent and / or a leveling agent from the viewpoint of processability, and it is suitable to add a silicone-based leveling agent and / or a fluorine-based leveling agent from the viewpoint of adding F and Si.

[0174] (solvent) The composition for forming the first retardation layer may contain a solvent. Generally, since the viscosity of the polymerizable liquid crystal compound is high, the composition for forming the first retardation layer is dissolved in a solvent, which makes it easy to apply, and as a result, it often becomes easy to form the first retardation layer. The solvent is preferably one that can completely dissolve the polymerizable liquid crystal compound, and is preferably a solvent that is inactive to the polymerization reaction of the polymerizable liquid crystal compound.

[0175] 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.

[0176] The content of the solvent is preferably 50 to 98% by mass relative to the total amount of the composition for forming the first retardation layer. In other words, the content of the solid content in the composition for forming the first retardation layer is preferably 2 to 50% by mass, more preferably 5 to 30% by mass. When the content of the solid content is 50% by mass or less, the viscosity of the composition for forming the first retardation layer is low, and the thickness of the first retardation layer becomes approximately uniform, which tends to reduce the occurrence of unevenness in the first retardation layer. In addition, the content of the solid content can be determined in consideration of the thickness of the optically anisotropic layer to be produced.

[0177] (Leveling agent) The composition for forming the first retardation layer 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 leveling agents, polyacrylate leveling agents, and perfluoroalkyl leveling agents. Among these, when horizontal alignment is performed, polyacrylate leveling agents and perfluoroalkyl leveling agents are preferred, and when vertical alignment is performed, organically modified silicone leveling agents and perfluoroalkyl leveling agents are preferred. Examples include silicone leveling agents, acrylic leveling agents, and fluorine leveling agents. Among these, silicone leveling agents and fluorine leveling agents are preferred, as they are excellent in reducing the surface tension of the film obtained by applying the composition.

[0178] Examples of silicone-based leveling agents include leveling agents having a polyorganosiloxane skeleton.

[0179] Examples of groups bonded to silicon atoms (silicon atoms forming siloxane bonds) in polyorganosiloxane include hydrocarbon groups. The silicone leveling agent may have two hydrocarbon groups bonded to a silicon atom. There are no limitations on the groups bonded to the silicon atoms, but among these, alkyl groups and aryl groups having 1 to 10 carbon atoms are preferred, more preferably methyl groups and phenyl groups, and even more preferably methyl groups. The group bonded to the silicon atom may be of one type or of two or more types. The number of repetitions of the siloxane unit (degree of polymerization) is not particularly limited, but is preferably 2 to 10,000, more preferably 3 to 5,000, and even more preferably 5 to 1,000.

[0180] As the silicone leveling agent, commercially available products can be used, for example, SH710 (manufactured by Toray Dow Corning Co., Ltd.), BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315N, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330, BYK -331, BYK-333, BYK-337, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYK-370, BYK-377, BYK-378, BYK-3455, BYK-UV3510 (all manufactured by BYK Japan Co., Ltd.), KF-945, KF-6015, KF-60 20 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TEGORad2300, TEGORad2200N, TEGORad2011 (manufactured by Degussa), and those having a radical polymerizable group such as a (meth)acryloyl group added to the polyether chain include BYK-UV3500, BYK-UV3505, BYK-3510, BYK-UV3530, BYK-UV3570, BYK-UV3575, BYK-UV3576 (all manufactured by BYK Japan KK), KP-422, KP-416, KP-418, KP-410, KP-411, KP-412, KP-413, KP-423, KP-414, KP-415, KP-420, and KP-983 (all manufactured by Shin-Etsu Chemical Co., Ltd.).

[0181] The content of the silicone-based leveling agent in the composition for forming the first retardation layer is preferably 0.001 to 2 parts by mass, more preferably 0.01 to 1.5 parts by mass, and even more preferably 0.1 to 1.5 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0182] The fluorine-based leveling agent is not particularly limited, but examples thereof include leveling agents having a fluoroaliphatic hydrocarbon skeleton. The fluoroaliphatic hydrocarbon skeleton is not particularly limited, but examples thereof include fluoroalkanes having 1 to 10 carbon atoms, such as fluoromethane, fluoroethane, fluoropropane, fluoroisopropane, fluorobutane, fluoroisobutane, fluoro-t-butane, fluoropentane, and fluorohexane. The fluoroaliphatic hydrocarbon skeleton may have at least some of the hydrogen atoms substituted with fluorine atoms, but may also be a perfluoroaliphatic hydrocarbon skeleton in which all of the hydrogen atoms are substituted with fluorine atoms.

[0183] The fluoroaliphatic hydrocarbon skeleton may also form a polyfluoroalkylene ether skeleton, which is a repeating unit via an ether bond. The fluoroaliphatic hydrocarbon group as a repeating unit is not particularly limited, but examples thereof include fluoro C1-4 alkylene groups such as fluoromethylene, fluoroethylene, fluoropropylene, and fluoroisopropylene. The fluoroaliphatic hydrocarbon group may be of one type only, or of two or more types. The number of repetitions (degree of polymerization) of the fluoroalkylene ether unit is not particularly limited, but is preferably 10 to 10,000, more preferably 30 to 5,000, and even more preferably 50 to 1,000.

[0184] Examples of fluorine-based leveling agents that can be used include commercially available products such as Megafac (registered trademark) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F-470, F-471, F-477, F-479, F-482, F-483, F-281, and F-253. , F-251, F-114, F-510, F-551, F-552, F-553, F-554, F-555, F-556, F-557, F -558, F-559, F-560, F-561, F-562, F-563, F-565, F-568, F-569, F-570, F-572 , F-574, F-575, F-576, R-40, R-41, R-94, RS-56, RS-72-K, RS-75, RS-76-E, RS-76-NS, RS-78, RS-90, and DS-21 (DIC Corporation); Surflon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, and SA-100 (AGC Seimi Chemical Co., Ltd.); E1830 and E5844 (Daikin Fine Chemical Research Institute, Ltd.); F-top EF301, F-top EF303, F-top EF351, and F-top EF352 (Mitsubishi Materials Electronic Chemicals Co., Ltd.).

[0185] The content of the fluorine-based leveling agent in the composition for forming the first retardation layer is preferably 0.001 to 2 parts by mass, more preferably 0.01 to 1.5 parts by mass, and even more preferably 0.1 to 1.5 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

[0186] When the composition for forming the first retardation layer contains various leveling agents, the amount 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, it is easy to horizontally align the polymerizable liquid crystal compound, and the resulting optically anisotropic layer tends to be smoother. When the content of the leveling agent relative to the polymerizable liquid crystal compound exceeds the above range, unevenness tends to occur in the resulting optically anisotropic layer. The composition for forming the optically anisotropic layer may contain two or more types of leveling agents.

[0187] (Polymerization initiator) The composition for forming the first retardation layer may contain a polymerization initiator. The polymerization initiator is a compound that can initiate a polymerization reaction of a polymerizable liquid crystal compound or the like. As the polymerization initiator, a photopolymerization initiator that generates active radicals by the action of light is preferred from the viewpoint that it is not dependent on the phase state of the thermotropic liquid crystal.

[0188] As the photopolymerization initiator, any known photopolymerization initiator can be used as long as it is a compound that can initiate the polymerization reaction of the polymerizable liquid crystal compound.Specific examples include photopolymerization initiators that can generate active radicals or acids by the action of light, and among these, photopolymerization initiators that generate radicals by the action of light are preferred.The photopolymerization initiators can be used alone or in combination of two or more.

[0189] 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.

[0190] The content of the polymerization initiator in the composition for forming the first retardation layer can be appropriately adjusted depending on the type and amount of the polymerizable liquid crystal compound, but may be 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.

[0191] (sensitizer) The composition for forming the first retardation layer 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.

[0192] When the composition for forming the first retardation layer contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the composition for forming the first retardation layer can be further accelerated. The amount of the sensitizer used is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the content of the polymerizable liquid crystal compound.

[0193] (antioxidant) From the viewpoint of stably progressing the polymerization reaction, the composition for forming the first retardation layer may contain an antioxidant. The antioxidant can control the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound.

[0194] 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.

[0195] When the composition for forming the first retardation layer contains an antioxidant, the content of the antioxidant is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the content of the polymerizable liquid crystal compound. The antioxidants can be used alone or in combination of two or more. When the content of the antioxidant is within the above range, polymerization can be carried out without disturbing the alignment of the polymerizable liquid crystal compound.

[0196] (reactive additives) The composition for forming the first retardation layer may contain a reactive additive. The reactive additive preferably has a carbon-carbon unsaturated bond, an active hydrogen reactive group, or a thiol group in its molecule. The term "active hydrogen reactive group" as used herein refers to a group reactive to a group having active hydrogen, such as a carboxyl group (-COOH), a hydroxyl group (-OH), or an amino group (-NH2), and typical examples thereof include a glycidyl group, an oxazoline group, a carbodiimide group, an aziridine group, an imide group, an isocyanate group, a thioisocyanate group, and a maleic anhydride group. The reactive additive may have 1 to 20 reactive groups, preferably 1 to 10 reactive groups.

[0197] (polymerizable monomer) The composition for forming the first retardation layer may contain a polymerizable monomer. When the composition for forming the first retardation layer contains a polymerizable monomer, the uniformity of the coating film and the strength of the film are improved. Examples of the polymerizable monomer include radically polymerizable or cationic polymerizable compounds. Among them, the polymerizable monomer is preferably a polyfunctional radically polymerizable monomer.

[0198] The polymerizable monomer is preferably one that can be copolymerized with the above-mentioned polymerizable liquid crystal compound. The content of the polymerizable monomer is preferably 1 to 50% by mass, more preferably 2 to 30% by mass, based on the total mass of the polymerizable liquid crystal compound.

[0199] (surfactant) The composition for forming the first retardation layer may contain a surfactant. When the composition for forming the first retardation layer contains a surfactant, the uniformity of the coating film and the strength of the film are improved. Examples of surfactants include conventionally known compounds. Among them, it is particularly preferable that the surfactant is a fluorine-based compound.

[0200] The Martens hardness of the surface of the first retardation layer on the first protective layer side is set to 100 N / mm from the viewpoint of suppressing deformation defects of the optical laminate and having sufficient crack resistance even under a heat shock environment. 2The Martens hardness of the surface of the first retardation layer on the first protective layer side is set to 130 N / mm 2 More than 150N / mm is preferable. 2 More preferably, 170N / mm 2 More preferably, 180N / mm 2 More preferably, 200N / mm 2 More than 220N / mm is particularly preferable. 2 More preferably, 230N / mm 2 The above is highly preferable. The Martens hardness of the surface of the first retardation layer on the side of the first protective layer is 300 N / mm 2 or less than 250N / mm 2 The Martens hardness can be measured by the method described in the examples below.

[0201] The Martens hardness of the surface of the first retardation layer on the first protective layer side can be adjusted by changing the method for forming the first retardation layer or the components contained therein. For example, the Martens hardness of the first retardation layer can be improved by including a polymerizable monomer or a surfactant in the composition for forming the first retardation layer. In addition, the degree of polymerization can be increased by adjusting the integrated light amount of ultraviolet light or the temperature during irradiation when curing the first retardation layer, and the Martens hardness of the first retardation layer can be improved.

[0202] The Martens hardness of the surface of the first retardation layer on the first protective layer side is preferably larger than the Martens hardness of the surface of the first retardation layer opposite to the first protective layer, from the viewpoint of suppressing scratches at the peeling interface on the first retardation film side when peeling the substrate from the first retardation film. The difference between the Martens hardness of the surface of the first retardation layer on the first protective layer side and the Martens hardness of the surface of the first retardation layer opposite to the first protective layer is, for example, 10 N / mm 2 It may be more than that.

[0203] {Method for forming first retardation layer} The first retardation layer can be formed by applying a retardation layer-forming composition to a substrate or the like, drying the retardation layer-forming composition, and then polymerizing the polymerizable liquid crystal compound.

[0204] (Coating of Retardation Layer-Forming Composition) For the first retardation layer, examples of a method for applying a retardation layer-forming composition to a substrate or a first alignment layer include extrusion coating, direct gravure coating, reverse gravure coating, CAP coating, slit coating, microgravure coating, die coating, and inkjet coating. Examples of a method for applying a retardation layer-forming composition include a method using a coater such as a dip coater, bar coater, or spin coater. Among these, when applying continuously in a roll-to-roll format, microgravure coating, inkjet coating, slit coating, and die coating are preferred, and when applying to a sheet substrate such as glass, spin coating, which has high uniformity, is preferred. When applying in a roll-to-roll format, a first alignment layer can be formed by applying a first alignment layer-forming composition to a substrate, and then continuously applying a retardation layer-forming composition to the resulting first alignment layer.

[0205] (base material) Examples of the substrate include glass substrates and film substrates, with film substrates being preferred, and long rolled films being more preferred in terms of continuous production. Examples of resins constituting the film substrate include polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; 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. Among these, from the viewpoint of transparency when used in optical film applications, it is more preferred that the substrate be a film substrate selected from triacetyl cellulose, cyclic olefin resins, polymethacrylic acid esters, and polyethylene terephthalate.

[0206] 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.).

[0207] 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 "S-Cina" (registered trademark), "SCA40" (registered trademark) (all manufactured by Sekisui Chemical Co., Ltd.), "ZEONORFILM" (registered trademark) (manufactured by Optes Co., Ltd.), and "ArtonFILM" (registered trademark) (manufactured by JSR Corporation).

[0208] 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 may be 5 to 300 μm, preferably 10 to 200 μm, more preferably 20 to 60 μm, and particularly preferably 30 to 50 μm. In particular, when the thickness of the substrate is 30 μm or more, when a retardation layer-forming composition is applied to the substrate and dried to form a coating film, and then the polymerizable liquid crystal compound in the coating film is polymerized to form a liquid crystal cured film, the occurrence of heat wrinkles in the substrate due to drying or irradiation with active energy rays tends to be suppressed. When the thickness is 50 μm or less, the bending resistance of the optical laminate tends to be further improved. In addition, by peeling off the substrate and transferring the polarizing film or liquid crystal cured film, a further thinning effect can be obtained.

[0209] 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 may be 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 a polarizing film or a retardation film, a further thinning effect can be obtained.

[0210] (Drying of the composition for forming the retardation layer) Examples of drying methods for removing the solvent contained in the retardation layer-forming composition include natural drying, ventilation drying, heat drying, reduced-pressure drying, and combinations of these. Among these, natural drying or heat drying is preferred. The drying temperature is preferably in the range of 0 to 200°C, more preferably in the range of 20 to 150°C, and even more preferably in the range of 50 to 130°C. The drying time is preferably 10 seconds to 10 minutes, and more preferably 30 seconds to 5 minutes.

[0211] (Polymerization of polymerizable liquid crystal compounds) Photopolymerization is a preferred method for polymerizing a polymerizable liquid crystal compound. Photopolymerization is carried out by irradiating an optical laminate in which a retardation layer-forming composition containing a polymerizable liquid crystal compound is applied to a substrate or a first alignment layer with active energy rays. The active energy rays to be irradiated are appropriately selected depending on the type of polymerizable liquid crystal compound contained in the dried coating (particularly the type of photopolymerizable functional group possessed by the polymerizable liquid crystal compound), and the type and amount of photopolymerization initiator, if any. Specific examples include one or more types of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays. Among these, ultraviolet light is preferred because it is easy to control the progress of the polymerization reaction and photopolymerization equipment widely used in the field can be used. It is preferable to select the type of polymerizable liquid crystal compound so that it can be photopolymerized by ultraviolet light.

[0212] Examples of light sources for actinic rays include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, LED light sources emitting light in the wavelength range of 380 to 440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps.

[0213] The ultraviolet irradiation intensity is, for example, 10 mW / cm 2 ~3000mW / cm 2 The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for activating a cationic polymerization initiator or a radical polymerization initiator. The light irradiation time may be 0.1 seconds to 10 minutes, preferably 1 second to 5 minutes, more preferably 5 seconds to 3 minutes, and even more preferably 10 seconds to 1 minute. When irradiating once or multiple times with such ultraviolet irradiation intensity, the cumulative light amount is 10 mJ / cm 2 ~3000mJ / cm 2 and preferably 50 mJ / cm 2 ~2000mJ / cm 2 and more preferably 100 mJ / cm 2 ~1000mJ / cm2 When the accumulated light amount is within this range, the polymerizable liquid crystal compound is sufficiently cured, and good transferability tends to be obtained, and coloring of the optical film including the optically anisotropic layer is easily suppressed.

[0214] Ultraviolet light can be irradiated in one or more steps. The cumulative light dose at a wavelength of 365 nm is 700 mJ / cm2, depending on the polymerization initiator used. 2 It is preferable that the dose is 1100 mJ / cm or more. 2 More preferably, it is 1300 mJ / cm or more. 2 It is more preferable that the integrated light amount is 2000 mJ / cm or more. The integrated light amount is advantageous for increasing the polymerization rate of the polymerizable liquid crystal compound constituting the retardation film and improving the heat resistance. The integrated light amount at a wavelength of 365 nm is 2000 mJ / cm. 2 It is preferable that the dose is 1800 mJ / cm or less. 2 It is more preferable that the integrated light amount is set to the above value. By setting the integrated light amount to the above value, coloring of the retardation film can be suppressed.

[0215] When the coating layer of the retardation layer-forming composition is cured by ultraviolet irradiation, the temperature during ultraviolet irradiation is preferably 30° C. or higher, more preferably 40° C. or higher, and even more preferably 50° C. or higher, from the viewpoint of sufficiently increasing the degree of polymerization. Furthermore, if the temperature is too high, wrinkles may occur in the base layer, and there is a concern that unevenness in retardation may occur. Therefore, the temperature during ultraviolet irradiation is preferably 200° C. or lower, more preferably 120° C. or lower, even more preferably 90° C. or lower, and particularly preferably 75° C. or lower. The above-mentioned upper and lower limits can be combined arbitrarily.

[0216] <First orientation layer> The first retardation film may or may not include a first alignment layer. The first alignment layer has an alignment regulating force that aligns the polymerizable liquid crystal compound in a desired direction.

[0217] The first alignment layer facilitates the alignment of the polymerizable liquid crystal compound. The liquid crystal alignment state, such as horizontal alignment, vertical alignment, hybrid alignment, or tilted alignment, varies depending on the properties of the first alignment layer and the polymerizable liquid crystal compound, and any combination thereof can be selected. For example, if the first alignment layer is formed of a material that exerts horizontal alignment as an alignment restraining force, the polymerizable liquid crystal compound can form horizontal or hybrid alignment. Furthermore, if the first alignment layer is formed of a material that exerts 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 first retardation layer. For example, vertical alignment means that the optical axis of the aligned polymerizable liquid crystal compound is perpendicular to the plane of the first retardation layer. Here, vertical means 90°±20° relative to the plane of the first retardation layer.

[0218] When the first alignment layer is formed from an alignment polymer, the alignment restraining force can be adjusted arbitrarily by the surface state or rubbing conditions, and when it is formed from 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.

[0219] The first alignment layer formed between the first retardation layer and the first retardation layer is preferably insoluble in the solvent used when forming the first retardation layer on the first alignment layer, and has heat resistance in the heat treatment for removing the solvent and aligning the liquid crystal. The first alignment layer includes a first alignment layer made of an orientable polymer, a photo-alignment film, a groove alignment film, a stretched film stretched in the alignment direction, etc. When applied to a long roll film, a photo-alignment film is preferred because the alignment direction can be easily controlled.

[0220] The thickness of the first alignment layer may be 10 nm to 5000 nm, preferably in the range of 10 nm to 1000 nm, and more preferably 30 to 300 nm.

[0221] Examples of the alignment polymer used for the rubbed alignment film 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, etc. Among these, polyvinyl alcohol is preferred.

[0222] 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.

[0223] 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.

[0224] 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 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.

[0225] Examples of photoreactive groups having a C=C bond include vinyl groups, polyene groups, stilbene groups, stilbazole groups, stilbazolium groups, chalcone groups, and cinnamoyl groups. Chalcone and cinnamoyl groups are preferred because of their ease of reactivity control and the ability to exert alignment-controlling 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.

[0226] The polarized light may be irradiated 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 to be irradiated should be within a wavelength range in which the photoreactive group of 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 the 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.

[0227] <Second retardation film and third retardation film> The second retardation film and the third retardation film can appropriately refer to the configuration of the first retardation film described above.

[0228] <Second lamination layer and sixth lamination layer> The second bonding layer has a function of bonding the first retardation film and the second retardation film. The sixth bonding layer has a function of bonding the second retardation film and the third retardation film. The configurations of the second bonding layer and the sixth bonding layer can be referenced to the description of the first bonding layer described above. The second bonding layer and the sixth bonding layer may each independently be made of the same material as the first bonding layer, or may be made of a different material.

[0229] The optical laminate according to one embodiment may further include a polarizer layer. When the optical laminate includes a polarizer layer, the polarizer layer is provided on the side of the first protective layer opposite to the first retardation film side. The polarizer layer may be bonded to the surface of the first protective layer via a third bonding layer provided on the surface of the first protective layer.

[0230] <Polarizer layer> The polarizer layer can be, for example, a film obtained by uniaxially stretching a polymer such as a polyvinyl alcohol-based resin film (hereinafter also referred to as a "PVA-based film") impregnated with iodine or an organic dichroic dye. A polarizer can be produced, for example, by uniaxially stretching a polyvinyl alcohol-based resin film (hereinafter also referred to as 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 in 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 a boric acid treatment). The polarizer layer may contain a crosslinking agent. A polarizer layer made of a polymer of a polymerizable liquid crystal compound containing a dichroic dye is preferred because it allows for arbitrary control of the hue, can be significantly thinned, and is non-shrinkable due to no relaxation due to heat stretching. For example, it can be used effectively in flexible displays.

[0231] The thickness of the polarizer layer may be 30 μm or less, preferably 18 μm or less, more preferably 15 μm or less, and even more preferably 12 μm or less. By setting the thickness of the polarizer layer to the above upper limit or less, the bending resistance of the optical laminate can be further improved. The thickness of the polarizer layer may be 1 μm or more, or 5 μm or more.

[0232] 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, or uniaxial stretching may be performed in multiple stages. Examples of uniaxial stretching include uniaxial stretching in the film transport direction between rolls with different peripheral speeds, uniaxial stretching in the film transport direction using a heated roll, and stretching in the width direction using a tenter. The uniaxial stretching may be performed by dry stretching in the air, or by wet stretching in a swollen state using a solvent such as water. The stretching ratio may be 3 to 8 times. Alternatively, an aqueous solution containing polyvinyl alcohol may be applied to a thermoplastic resin film, followed by drying, and then stretched together with the thermoplastic resin film by the above-mentioned method.

[0233] 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.

[0234] When iodine is used as the dichroic dye, for example, a method of dyeing a PVA-based film by immersing it in an aqueous solution containing iodine and potassium iodide is employed. The content of iodine in the aqueous solution may be 0.01 to 1 part by mass per 100 parts by mass of water, and the content of potassium iodide may be 0.5 to 20 parts by mass per 100 parts by mass of water. The temperature of the aqueous solution used for dyeing may be 20 to 40°C. The immersion time in the aqueous solution (dyeing time) may be 20 to 1800 seconds.

[0235] 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 may be 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 may be 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 may be 60 to 1200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution may be 50°C or higher, preferably 50 to 85°C, and more preferably 60 to 80°C.

[0236] The PVA-based film after the boric acid treatment may be subjected to, for example, a water-washing treatment. The water-washing treatment may be carried out, for example, by immersing the boric acid-treated PVA-based film in water. The temperature of the water used in the water-washing treatment may be 5 to 40°C. The immersion time may be 1 to 120 seconds.

[0237] After washing with water, the polarizer is obtained by drying. The drying can be performed using a hot air dryer or a far-infrared heater. The temperature for the drying may be 30 to 100°C, preferably 50 to 80°C. The drying time may be 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 may be 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, and defects are reduced and axial misalignment can be suppressed.

[0238] In this manner, a polarizer in which a dichroic dye is adsorbed and oriented in a PVA film can be produced. The polarizer may have a protective film attached to one or both surfaces thereof via the above-mentioned adhesive.

[0239] The polarizer layer can be formed by applying a polarizing film-forming composition to orient the dichroic dye contained in the polarizing film-forming composition. The polarizing film-forming composition may further contain a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesion improver, etc.

[0240] In a polarizer layer in which a dichroic dye and a polymerizable liquid crystal compound are aligned horizontally relative to the substrate surface, the ratio (dichroic ratio) of the absorbance A1(λ) in the alignment direction to the absorbance A2(λ) in the direction perpendicular to the alignment plane for light with a wavelength of λ nm is preferably 7 or more, more preferably 20 or more, and even more preferably 40 or more. The higher this value, the more excellent the absorption selectivity of the polarizer. While it depends on the type of dichroic dye, in the case of a liquid crystal cured film cured in a nematic liquid crystal phase state, the ratio is about 5 to 10.

[0241] By mixing two or more dichroic dyes with different absorption wavelengths, polarizer layers of various hues can be formed, and polarizer layers with absorption properties across the entire visible light range can be obtained. A polarizer layer with such absorption properties can be used in a variety of applications.

[0242] The polymerizable liquid crystal compound may be the above-mentioned polymerizable liquid crystal compound. The liquid crystal property may be thermotropic liquid crystal or lyotropic liquid crystal, but when mixed with a dichroic dye, thermotropic liquid crystal is preferable. The polymerizable liquid crystal compound may be a monomer or a polymer obtained by polymerizing dimers or higher.

[0243] When the polymerizable liquid crystal compound is a thermotropic liquid crystal, it may be a thermotropic liquid crystal compound exhibiting a nematic liquid crystal phase or a thermotropic liquid crystal compound exhibiting a smectic liquid crystal phase. From the viewpoint of exhibiting high dichroism, the liquid crystal state exhibited by the polymerizable liquid crystal compound is preferably a smectic phase, and from the viewpoint of improving performance, a higher-order smectic phase is more preferable. Among these, higher-order smectic liquid crystal compounds that form a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, or a smectic L phase are more preferable, and higher-order smectic liquid crystal compounds that form a smectic B phase, a smectic F phase, or a smectic I phase are even more preferable. When the liquid crystal phase formed by the polymerizable liquid crystal compound is one of these higher-order smectic phases, a polarizing film with higher polarization performance can be produced. Furthermore, such a polarizer layer with high polarization performance exhibits Bragg peaks derived from higher-order structures such as hexatic and crystalline phases in X-ray diffraction measurements. Bragg peaks are peaks derived from the periodic structure of molecular orientation, and films with periodic intervals of 3 to 6 Å can be obtained. The polarizer layer exhibits even higher polarization properties when it contains a polymer of polymerizable liquid crystal oriented in a smectic phase.

[0244] The content of the polymerizable liquid crystal compound in the composition for forming a polarizing film of the present invention is preferably 40 to 99.9 mass %, more preferably 60 to 99 mass %, and even more preferably 70 to 99 mass %, based on the solid content of the polymerizable liquid crystal composition. When the content of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound tends to be high. Note that this refers to the total amount of components excluding the solvent from the composition for forming a polarizing film.

[0245] A dichroic dye refers to a dye having different absorbance in the long axis direction and the short axis direction of the molecule. Dichroic dyes preferably have the property of absorbing visible light, and more preferably have an absorption maximum wavelength (λMAX) in the range of 380 to 680 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes, with azo dyes being preferred. Examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, with bisazo dyes and trisazo dyes being preferred. Dichroic dyes may be used alone or in combination. However, to achieve absorption across the entire visible light range, it is preferred to combine two or more dichroic dyes, and more preferably to combine three or more dichroic dyes.

[0246] Examples of azo dyes include compounds represented by formula (α) (hereinafter, also referred to as "compound α"). T 1 -A 1 (-N=NA 2 ) p -N=NA 3 -T 2 (α) [In formula (α), A 1 , A 2 , and A 3 represent, independently of each other, an optionally substituted 1,4-phenylene group, an optionally substituted naphthalene-1,4-diyl group, an optionally substituted benzoic acid phenyl ester group, an optionally substituted 4,4'-stilbenylene group, or an optionally substituted divalent heterocyclic group; T 1 and T 2 is an electron-withdrawing group or an electron-releasing group, and is positioned at a position substantially at 180° with respect to the plane of the azo bond. p represents an integer of 0 to 4. When p is 2 or more, each A 2 may be the same or different. The -N=N- bond may be replaced with a -C=C-, -COO-, -NHCO-, or -N=CH- bond as long as the compound exhibits absorption in the visible region.

[0247] The content of the dichroic dye (the total amount when multiple types are included) may be 1 to 60 parts by mass, preferably 1 to 40 parts by mass, and more preferably 1 to 20 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound, from the viewpoint of obtaining good light absorption properties. If the content of the dichroic dye is less than this range, light absorption will be insufficient and sufficient polarization performance will not be obtained, whereas if the content is greater than this range, the alignment of the liquid crystal molecules may be hindered.

[0248] The polarization performance of a polarizer can be measured using a spectrophotometer. For example, the transmittance (T 1 ) and transmittance in the absorption axis direction (orientation direction) (T 2 ) can be measured by the double beam method using a spectrophotometer equipped with a prism polarizer. Polarization performance in the visible light range can be calculated by calculating the single transmittance and degree of polarization at each wavelength using the following formulas (Formula 1) and (Formula 2), and then performing luminosity correction using the 2-degree visual field (C light source) of JIS Z 8701 to calculate the luminosity-corrected single transmittance (Ty) and luminosity-corrected degree of polarization (Py). In addition, the color matching function for C light source can be used to calculate the L from the transmittance measured in the same way. * a * b * Chromaticity a in the (CIE) color system * and b * By calculating the above, the hue of the polarizer alone (single hue), the hue when the polarizers are arranged in parallel (parallel hue), and the hue when the polarizers are arranged perpendicularly (orthogonal hue) can be obtained. * and b * The closer the value is to 0, the more neutral the hue is. Single unit transmittance (%) = (T 1 +T 2 ) / 2 …(Formula 1) Polarization degree (%) = (T 1 -T 2 ) / (T 1 +T 2 )×100…(Formula 2)

[0249] The luminosity-corrected polarization degree Py of the polarizer may be 80% or more, preferably 90% or more, more preferably 95% or more, even more preferably 98% or more, and particularly preferably 99% or more. If it is 99.9% or more, it can be suitably used in liquid crystal displays. Increasing the luminosity-corrected polarization degree Py of the polarizer is advantageous in improving the antireflection function of the optical laminate. If the luminosity-corrected polarization degree Py is less than 80%, the polarizer may not be able to achieve the antireflection function when used as an antireflection film.

[0250] The higher the luminous-effect-corrected single transmittance Ty of the polarizer, the greater the clarity of the white display. However, as can be seen from the relationship between (Equation 1) and (Equation 2), if the single transmittance is too high, the degree of polarization decreases. Therefore, the luminous-effect-corrected single transmittance Ty is preferably 30% or more, more preferably 35% or more, even more preferably 38% or more, and particularly preferably 40% or more. Furthermore, the luminous-effect-corrected single transmittance Ty is preferably 60% or less, more preferably 55% or less, and even more preferably 50% or less. From the viewpoint of improving the reflection hue, it is particularly preferably 43% or more and 46% or less. If the luminous-effect-corrected single transmittance Ty is excessively high, the luminous-effect-corrected polarization degree Py becomes too low, which may result in insufficient anti-reflection function when used as an anti-reflection film.

[0251] <Third lamination layer and fourth lamination layer> The third bonding layer has a function of bonding the polarizer layer and the first protective layer. The fourth bonding layer has a function of bonding the polarizer layer and the second protective layer described below. For the third bonding layer and the fourth bonding layer, the description of the first bonding layer or the third bonding layer described above can be referred to. The fourth bonding layer may be made of the same material as the first bonding layer or the third bonding layer, or may be made of a different material.

[0252] <Polarizing plate> The polarizing plate may be a single-protected polarizing plate in which a protective layer is laminated on one side of a polarizer via an adhesive layer, or a double-protected polarizing plate in which protective layers are laminated on both sides of a polarizer via adhesive layers. For example, the polarizing plate may be laminated in the order of polarizer / third adhesive layer / first protective layer, or may be laminated in the order of second protective layer / fourth adhesive layer / polarizer / third adhesive layer / first protective layer.

[0253] The optical laminate according to one embodiment may further include a second protective layer on the side of the polarizer layer opposite to the first protective layer. When the optical laminate includes the second protective layer, the polarizer layer and the second protective layer may be directly laminated to each other. Here, "directly laminated" includes an embodiment in which the second protective layer is laminated to the polarizer layer by the self-adhesive property of the second protective layer, and an embodiment in which the second protective layer is laminated via an adhesive layer or a pressure-sensitive adhesive layer.

[0254] <Second protective layer> The second protective layer has a function of protecting the surface of the polarizer layer. The configuration of the second protective layer can be referred to the description of the first protective layer above. The second protective layer may be made of the same material as the first protective layer, or may be made of a different material. The second protective layer may be subjected to a surface treatment (e.g., corona treatment) to improve adhesion to the polarizer layer, and may have a thin layer such as a primer layer (also referred to as an easy-adhesion layer) formed thereon.

[0255] The second protective layer may be subjected to surface treatments such as hard coating, anti-reflection, anti-sticking, and anti-glare, as needed. Furthermore, the second protective layer may be subjected to treatments to improve visibility when viewed through polarized sunglasses (for example, by providing a circular polarization function or an elliptically polarizing function, or by providing an ultra-high phase difference), as needed. By performing such treatments, excellent visibility can be achieved even when the display screen is viewed through polarized lenses such as polarized sunglasses. Therefore, an optical laminate including a second protective layer that has been subjected to such treatments can be suitably applied to image display devices that can be used outdoors.

[0256] <Fifth lamination layer> The fifth bonding layer is disposed on the surface of the optical laminate on the second retardation film side and has the function of bonding to the image display device. The fifth bonding layer can refer to the description of the first bonding layer described above, and the fifth bonding layer is preferably a pressure-sensitive adhesive layer. The fifth bonding layer may be made of the same material as the other bonding layers, or may be made of a different material.

[0257] [Optical laminate] The optical laminate described above can be used as a circular polarizer, which is an optical component in which a polarizer and a retardation film are laminated, and can be used to prevent light reflection from electrodes constituting a device that displays images in a flat state, such as an organic EL image display device.

[0258] From the viewpoint of obtaining good flex resistance, the thickness of the optical laminate may be 70 μm or more, preferably 80 μm or more, and may be 150 μm or less, preferably 120 μm or less.

[0259] [Method of manufacturing optical laminate] An optical laminate according to one embodiment can be produced by a method including the steps of: preparing a first retardation film including a first retardation layer and a first alignment layer; and providing a first protective layer on the surface of the first retardation film on the side of the first retardation layer via a first bonding layer to obtain a first optical laminate. In this production method, the Martens hardness of the surface of the first retardation layer on the side of the first protective layer is 100 N / mm 2 The ratio of the Martens hardness of the surface of the first retardation layer on the first protective layer side to the Martens hardness of the first protective layer is 1.5 or more. According to this manufacturing method, it is possible to manufacture an optical laminate that has sufficient crack resistance even in a heat shock environment while suppressing deformation defects.

[0260] When the optical laminate has a second retardation film, the first retardation film and the first protective layer can be joined by forward bonding or first bonding.

[0261] In the forward lamination method, the first protective layer and the first retardation layer of the first retardation film are first bonded via a bonding layer. Next, the first retardation layer of the first retardation film is peeled at the interface between the first retardation layer and the first alignment layer. Next, the first retardation layer and the second retardation layer of the second retardation film are bonded via a bonding layer. Furthermore, a bonding layer and a separator film are formed in this order from the exposed surface (the surface of the second retardation layer or the second alignment layer) exposed by the process of separating the substrate layer (or the second alignment layer) of the second retardation film. The separator film can cover and protect the surface of the bonding layer opposite the second retardation layer, and can be provided so as to be releasable from the bonding layer. This allows for the production of an optical laminate in which the first protective layer, bonding layer, first retardation layer, bonding layer, second retardation layer, and bonding layer are stacked in this order. It is also possible to obtain an optical laminate in which the first orientation layer is bonded to the second retardation layer of the second retardation film via a bonding layer, without peeling at the interface between the first retardation layer of the first retardation film and the first alignment layer, and the first alignment layer is peeled from the substrate. In this case, an optical laminate can be obtained in which the first protective layer, the attachment layer, the first alignment layer, the first retardation layer, the attachment layer, and the second retardation layer are laminated in this order.

[0262] In the case of pre-attaching, first, the first retardation layer of the first retardation film and the second retardation layer of the second retardation film are bonded via an adhesive layer. Next, the first retardation layer of the first retardation film is peeled at the interface between the first retardation layer and the first alignment layer. Next, the first protective layer and the first retardation layer are bonded via an adhesive layer. Furthermore, an adhesive layer and a separator film are formed in this order from the exposed surface (the surface of the second retardation layer or the second alignment layer) exposed by the process of separating the substrate layer (or the second alignment layer) of the second retardation film. The separator film can cover and protect the surface of the adhesive layer opposite the second retardation layer, and can be provided so as to be releasable from the adhesive layer. This allows for the production of an optical laminate in which the first protective layer, adhesive layer, first retardation layer, adhesive layer, second retardation layer, and adhesive layer are laminated in this order. Note that instead of peeling at the interface between the first retardation layer and the first alignment layer of the first retardation film, the first alignment layer may be peeled from the substrate, and the first alignment layer may be bonded to the second retardation layer of the second retardation film via an adhesive layer. In this case, an optical laminate can be obtained in which the first protective layer, the attachment layer, the first alignment layer, the first retardation layer, the attachment layer, and the second retardation layer are laminated in this order.

[0263] [Image display device] The image display device includes an optical laminate and an image display element (such as an organic EL display element). The optical laminate is disposed on the viewing side of the image display element. The optical laminate can be attached to the image display element using a pressure-sensitive adhesive layer.

[0264] 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.

[0265] The image display device can be used as mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic signs, measuring instruments or meters, office equipment, medical equipment, computing equipment, and the like. [Example]

[0266] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples. Unless otherwise specified, "%" and "parts" in the examples mean % by mass and parts by mass, respectively.

[0267] 1. Preparation of the first retardation film with substrate 1-1. Preparation of the first retardation film (1) with a substrate 1-1-1. Preparation of composition (1) for forming alignment film Water was added to commercially available polyvinyl alcohol (polyvinyl alcohol 1000 fully saponified type, manufactured by Wako Pure Chemical Industries, Ltd.), and the mixture was heated at 100° C. for 1 hour to obtain a composition (1) for forming an alignment film.

[0268] 1-1-2. Preparation of polymerizable liquid crystal compounds Polymerizable liquid crystal compound (A1) and polymerizable liquid crystal compound (A2) having the structures shown below were prepared. The polymerizable liquid crystal compound (A1) and polymerizable liquid crystal compound (A2) were prepared in the same manner as described in JP-A-2010-244038. Polymerizable liquid crystal compound (A1): [ka] Polymerizable liquid crystal compound (A2): [ka]

[0269] 1-1-3. Preparation of first retardation layer forming composition (1) Polymerizable liquid crystal compound (A1) and polymerizable liquid crystal compound (A2) were mixed in a mass ratio of 80:20 to obtain a mixture. To 100 parts of the obtained mixture, 8 parts of dipentaerythritol hexaacrylate (DPHA; manufactured by Tokyo Chemical Industry Co., Ltd.), 0.1 parts of the leveling agent "Megafac F-556" (manufactured by DIC Corporation), 2.5 parts of the photopolymerization initiator "Omnirad907" (manufactured by IGM Resin BV), and 0.1 parts of the ionic compound (B) were added. Furthermore, 650 parts of cyclopentanone was added, and the mixture was stirred at a temperature of 80 ° C. for 1 hour to prepare a first retardation layer-forming composition (1). Ionic compounds (B): [ka]

[0270] 1-1-4. Preparation of the first retardation film (1) with substrate A cyclic polyolefin resin (COP) film (ZF14, manufactured by Zeon Corporation) was used as a substrate, and after corona treatment was performed using a corona treatment device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.), the composition for forming an alignment film (1) was applied, and after heating and drying, an alignment film with a thickness of 100 nm was formed. The surface of the obtained alignment film was subjected to a rubbing treatment, and the composition for forming a first retardation layer (1) was applied thereon using a bar coater. The obtained coating film was dried at 120°C for 2 minutes, and then exposed to 1000 mJ / cm2 at 80°C under a nitrogen atmosphere using a high-pressure mercury lamp (Uniqure VB-15201BY-A, manufactured by Ushio Inc.). 2 The dried film was irradiated with ultraviolet light (365 nm standard) to form a first retardation layer (1) in which the polymerizable liquid crystal compound was cured with its optical axis aligned horizontally relative to the substrate plane, thereby obtaining a substrate-attached first retardation film (1) consisting of substrate / alignment film / first retardation layer (1). The thickness of the obtained first retardation layer (1) was measured with a laser microscope and found to be 1.4 μm. The in-plane retardation value at a wavelength of 550 nm was Re(550) = 270 nm. Note that the retardation value of the COP film at a wavelength of 550 nm is approximately 0, so there is no effect on the optical properties.

[0271] 1-2. Preparation of the first retardation film (2) with substrate A substrate-attached first retardation film (2) was obtained in the same manner as the substrate-attached first retardation film (1), except that the dried film was irradiated with ultraviolet light twice to form a first retardation layer (2) so that the thickness of the first retardation layer (1) was 1.6 μm. The in-plane retardation value of the first retardation layer (2) was the same as that of the first retardation layer (1).

[0272] 1-3. Preparation of the first retardation film (3) with substrate 1-3-1. Preparation of composition for forming photo-alignment film The photo-alignment material (weight average molecular weight: 50,000, m:n = 50:50) with the following structure was produced in accordance with the method described in JP 2021-196514 A. Two parts by mass of the photo-alignment material and 98 parts by mass of cyclopentanone (solvent) were mixed as components, and the resulting mixture was stirred at 80°C for one hour to prepare a composition for forming a photo-alignment film. Photoalignable materials: [ka]

[0273] 1-3-2. Preparation of polymerizable liquid crystal compounds Polymerizable liquid crystal compound (A3) and polymerizable liquid crystal compound (A4) having the structures shown below were prepared. Polymerizable liquid crystal compound (A3) was prepared in the same manner as described in JP-A-2019-003177. Polymerizable liquid crystal compound (A4) was prepared in the same manner as described in JP-A-2009-173893. Polymerizable liquid crystal compound (A3): [ka] Polymerizable liquid crystal compound (A4): [ka]

[0274] 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.

[0275] 1-3-3. Preparation of first retardation layer forming composition (2) Polymerizable liquid crystal compound (A3) and polymerizable liquid crystal compound (A4) were mixed in a mass ratio of 90:10 to obtain a mixture. To 100 parts by mass of the obtained mixture, 8 parts by mass of dipentaerythritol hexaacrylate (DPHA; manufactured by Tokyo Chemical Industry Co., Ltd.), 0.1 parts by mass of the leveling agent "BYK-361N" (manufactured by BM Chemie), and 3 parts by mass of the photopolymerization initiator "Irgacure OXE-03" (manufactured by BASF Japan Ltd.) were added. Furthermore, N-methyl-2-pyrrolidone (NMP) was added to obtain a solids concentration of 13% by mass. The mixture was stirred at 80°C for 1 hour to prepare a first retardation layer-forming composition (2).

[0276] 1-3-4. Preparation of the first retardation film (3) with substrate The composition for forming a photo-alignment film was applied to a cyclic polyolefin resin (COP) film (ZF14, manufactured by Zeon Corporation) as a substrate 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. A UV irradiation device (SPOT CURE SP-9, manufactured by Ushio Inc.) was then used to irradiate the film with 100 mJ of polarized ultraviolet light (313 nm standard) to obtain a photo-alignment film. The thickness of the photo-alignment film was measured using an ellipsometer M-220 manufactured by JASCO Corporation and was 100 nm.

[0277] The first retardation layer-forming composition (2) was applied onto the obtained photo-alignment film using a bar coater to form a coating film. This coating film was heated and dried at 120°C for 1 minute. The film was placed on a hot plate set to 60°C so that the substrate layer surface of the obtained coating film was in contact with the hot plate. The hot plate was placed in a case, and nitrogen was sealed in for 1 minute. Using a high-pressure mercury lamp (Uniquer VB-15201BY-A, manufactured by Ushio Inc.), ultraviolet light was irradiated onto the surface coated with the first retardation layer-forming composition (3) (under a nitrogen atmosphere, wavelength: 365 nm, irradiation intensity at wavelength 365 nm: 10 mW / cm). 2 , Accumulated light intensity: 1000mJ / cm 2 ) to form a first retardation layer (3), thereby obtaining a substrate-attached first retardation film (3) consisting of a substrate / photo-alignment film / first retardation layer (3) (cured film of horizontally aligned liquid crystal). The film thickness of the first retardation layer (3) measured using a laser microscope LEXT OLS4100 manufactured by Olympus Corporation was 2.1 μm.

[0278] The surface of the substrate-attached first retardation film (3) on the side of the first retardation layer (3) was corona-treated, and the film was attached to glass using a 25 μm pressure-sensitive adhesive manufactured by Lintec Corporation. The substrate was then peeled off and removed. The in-plane retardation values ​​for light with wavelengths of 450 nm, 550 nm, and 650 nm were measured using a KOBRA-WR film manufactured by Oji Scientific Instruments. The in-plane retardation values ​​for light with wavelengths of 448.2 nm, 498.6 nm, 548.4 nm, 587.3 nm, 628.7 nm, and 748.6 nm were calculated using Cauchy's dispersion formula. The resulting in-plane retardation values ​​were Re(450) = 122 nm, Re(550) = 140 nm, and Re(650) = 144 nm. The relationship between the in-plane retardation values ​​at each wavelength was as follows: Re(450) / Re(550)=0.87 Re(650) / Re(550)=1.03 (In the formula, Re(450) represents the in-plane retardation value for light with a wavelength of 450 nm, Re(550) represents the in-plane retardation value for light with a wavelength of 550 nm, and Re(650) represents the in-plane retardation value for light with a wavelength of 650 nm.)

[0279] 1-4. Preparation of the first retardation film (4) with substrate A substrate-attached first retardation film (4) was obtained in the same manner as the substrate-attached first retardation film (3), except that the dried film was irradiated with ultraviolet light twice to form a first retardation layer (4) with a thickness of 2.7 μm. The in-plane retardation value of the first retardation layer (4) was the same as that of the first retardation layer (3).

[0280] 1-5. Preparation of the first retardation film (5) with substrate 1-5-1. Preparation of first retardation layer forming composition (3) Polymerizable liquid crystal compound (A3) and polymerizable liquid crystal compound (A4) were mixed in a mass ratio of 90:10 to obtain a mixture. To 100 parts by mass of the obtained mixture, 0.1 parts by mass of a leveling agent "BYK-361N" (manufactured by BM Chemie) and 3 parts by mass 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 solid content concentration became 13% by mass. This mixture was stirred at a temperature of 80°C for 1 hour to prepare a first retardation layer-forming composition (3).

[0281] 1-5-2. Preparation of the first retardation film (5) with substrate A substrate-attached first retardation film (5) was obtained in the same manner as the substrate-attached first retardation film (3), except that the first retardation layer (5) was formed using the first retardation layer-forming composition (3) instead of the first retardation layer-forming composition (2) and so that the film thickness of the first retardation layer (3) was 2.1 μm. The in-plane retardation value of the first retardation layer (5) was the same as that of the first retardation layer (3).

[0282] 2. Preparation of second retardation film with substrate 2-1. Preparation of second retardation film (1) with substrate 2-1-1. Preparation of second retardation layer forming composition (1) 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 a second retardation layer forming composition (1). Polymerizable liquid crystal compound LC242: [ka]

[0283] 2-1-2. Preparation of second retardation film (1) with substrate The substrate was a triacetyl cellulose (TAC) film (KC4UY (thickness 40 μm) manufactured by Konica Minolta, Inc.), and the composition for forming an alignment film (1) was applied to the substrate in the same manner as in the first retardation film (1) with the substrate. After heating and drying, an alignment film with a thickness of 100 nm was formed. The surface of the obtained alignment film was subjected to a rubbing treatment, and the composition for forming a second retardation layer (1) was applied thereon using a bar coater. The obtained coating layer was dried at 100°C for 1 minute and then cooled to room temperature to obtain a dried film. Next, a high-pressure mercury lamp (Uniqure VB-15201BY-A manufactured by Ushio Inc.) was used to apply 1000 mJ / cm under a nitrogen atmosphere. 2 By irradiating the dried film with ultraviolet light (365 nm standard), a second retardation layer (1) (horizontally aligned liquid crystal cured film) was formed in which the polymerizable liquid crystal compound was cured in a state where it was aligned horizontally relative to the plane of the substrate, and a substrate-attached second retardation film (1) consisting of substrate / alignment film / second retardation layer (1) was obtained.

[0284] The thickness of the obtained second retardation layer (1) was measured with a laser microscope and found to be 1.0 μm. The in-plane retardation value of the substrate-attached second retardation film (1) was measured using a KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. As a result, the in-plane retardation value at a wavelength of 550 nm was Re(550)=140 nm. Note that the retardation value at a wavelength of 550 nm of the TAC film substrate is approximately 0, so this does not affect the optical properties. The second retardation layer (1) had positive wavelength dispersion.

[0285] 2-2. Preparation of second retardation film (2) with substrate 2-2-1. Preparation of composition (2) for forming alignment film 2-Butoxyethanol was added to a commercially available aligning polymer, Sunever SE-610 (manufactured by Nissan Chemical Industries, Ltd.), so that the solid content was 1%, to obtain an aligning film-forming composition (2).

[0286] 2-2-2. Preparation of second retardation film (2) with substrate A cycloolefin polymer (COP) (ZF14, manufactured by Zeon Corporation) was used as a substrate, and the surface was subjected to corona treatment using a corona treatment device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.). The alignment film-forming composition (2) was applied to the surface using a bar coater and dried at 90°C for 1 minute. The thickness of the resulting alignment film was measured using a laser microscope and found to be 30 nm. Subsequently, a second retardation layer-forming composition (1) was applied to the alignment film using a bar coater and dried at 90°C for 1 minute. The resulting alignment film was then exposed to light at a dose of 1000 mJ / cm2 under a nitrogen atmosphere using a high-pressure mercury lamp (Uniqure VB-15201BY-A, manufactured by Ushio Inc.). 2By irradiating the dried film with ultraviolet light (based on 365 nm), a retardation film with a substrate (2) composed of a substrate / orientation film / second retardation layer (2) was obtained. When the film thickness was measured with a laser microscope, the film thickness was 450 nm. The in-plane retardation value was measured using KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. As a result, Re(550) = 1 nm and the retardation value in the thickness direction Rth(550) = -70 nm. Thus, it had the optical properties represented by the following formula. The retardation film with a substrate (2) 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.

[0287] 2-3. Preparation of Retardation Film with Substrate (3) 2-3-1. Preparation of Composition for Forming Second Retardation Layer (2) In the preparation of the composition for forming the second retardation layer (1), the composition for forming the first retardation layer with a substrate (2) was prepared in the same manner as the composition for forming the first retardation layer with a substrate (1), except that 3 parts of "Laromer (registered trademark) LR-9000 (manufactured by BASF)" were further added to 100 parts of the polymerizable liquid crystal compound Paliocolor LC242 (manufactured by BASF Japan).

[0288] 2-3-2. Preparation of Retardation Film with Substrate (3) A retardation film with a substrate (3) composed of a substrate / orientation film / second retardation layer (3) was obtained in the same manner as the retardation film with a substrate (1), except that the composition for forming the second retardation layer (2) was used instead of the composition for forming the second retardation layer (1). The in-plane retardation value of the second retardation layer (3) was the same as that of the second retardation layer (1).

[0289] 2-4. Preparation of Retardation Film with Substrate (4) 2-4-1. Preparation of Composition for Forming Vertical Alignment Film The composition for forming the vertical alignment film was a mixture of 2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, dipentaerythritol triacrylate, and bis(2-vinyloxyethyl) ether in a ratio of 1:1:4:5, to which LUCIRIN TPO was added as a polymerization initiator in a ratio of 4%.

[0290] 2-4-2. Preparation of second retardation layer forming composition (3) The second retardation layer forming composition (3) was prepared by mixing a photopolymerizable nematic liquid crystal compound (RMM28B, manufactured by Merck) and a solvent so that the solid content was 1 to 1.5 g. The solvent used was a mixed solvent obtained by mixing methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone (CHN) in a mass ratio (MEK:MIBK:CHN) of 35:30:35.

[0291] 2-4-3. Preparation of second retardation film (4) with substrate A polyethylene terephthalate (PET) film having a thickness of 38 μm was prepared as a substrate. A composition for forming a vertical alignment film was applied to one side of the substrate to a thickness of 3 μm, and the applied voltage was 200 mJ / cm 2 A vertical alignment film was produced by irradiating the film with ultraviolet light. A composition (3) for forming a second retardation layer was applied onto the vertical alignment film by die coating. The applied amount was 4 to 5 g (wet). The coating film was dried at a drying temperature of 75°C for 120 seconds. Thereafter, the coating film was irradiated with ultraviolet light (UV) to polymerize the polymerizable liquid crystal compound and form a second retardation layer (4), thereby obtaining a second retardation film (4) with a substrate consisting of substrate / alignment film / second retardation layer (4).

[0292] The second retardation film (4) with a substrate was a positive C plate. The thickness of the second retardation layer (3) was 1 μm. The second retardation film (4) with a substrate was attached to glass via an adhesive, and then the substrate was peeled off to measure the in-plane retardation value of the second retardation layer (4). For the measurement, a "KOBRA-WPR" manufactured by Oji Scientific Instruments Co., Ltd. was used. The in-plane retardation value at a wavelength of 550 nm was Re(550) = 1 nm, and the retardation value in the thickness direction at a wavelength of 550 nm was Rth(550) = -100 nm. The second retardation layer (4) had positive wavelength dispersion.

[0293] 3. Preparation of the third retardation film with substrate As a third retardation film with a substrate, the same film as the second retardation film with a substrate (2) was prepared.

[0294] 4. Preparation of adhesive sheet (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 by mass of ethyl acetate, 99.0 parts by mass of butyl acrylate, 0.5 parts by mass of 2-hydroxyethyl acrylate, and 0.5 parts by mass of acrylic acid. The air inside the vessel was purged with nitrogen gas to remove oxygen, and the internal temperature was raised to 55°C. Subsequently, a solution of 0.12 parts by mass of azobisisobutyronitrile (polymerization initiator) dissolved in 10 parts by mass of ethyl acetate was added in its entirety. After the addition of the polymerization initiator, the internal temperature was maintained at 55°C for 1 hour. Then, ethyl acetate was continuously added to the reaction vessel at a rate of 17.3 parts by mass / hour while maintaining the internal temperature at 54-56°C. When the (meth)acrylic resin concentration reached 35% by mass, the addition of ethyl acetate was stopped, and the vessel was maintained at this temperature for a further 6 hours after the start of the ethyl acetate addition. Finally, ethyl acetate was added to adjust the (meth)acrylic resin concentration to 20% by mass, preparing acrylic resin solution (1). The resulting acrylic resin had a weight average molecular weight Mw of 1.7 million and a molecular weight distribution Mw / Mn of 3.9. Mw and Mn were measured using a GPC system with a TSKgel GMH column manufactured by Tosoh Corporation. HRTwo "-H(S)" were connected in series and arranged, and tetrahydrofuran was used as the eluent. The measurement was carried out in terms of standard polystyrene under the conditions of 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.

[0295] [Preparation of the Composition (1) for Forming the Adhesive Layer] Based on 80 parts by mass of the solid content of the acrylic resin solution (4), 20 parts by mass (solid content) of a bifunctional acrylate (obtained from Shin-Nakamura Chemical Co., Ltd.; product number "A-DOG"), 2.5 parts by mass of a crosslinking agent (manufactured by Tosoh Corporation: trade name "Coronate L" (ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate (solid content concentration 75% by mass))) based on the active ingredient, 1.5 parts by mass of a photoinitiator (manufactured by Ciba Specialty Chemicals: trade name "Irgacure 500"), and 0.3 parts by mass 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% by mass to obtain the composition (1) for forming the adhesive layer. Note that A-DOG is a diacrylate of an acetal compound of hydroxypivalaldehyde and trimethylolpropane and has the structure of the following formula. [Chemical Formula]

[0296] The composition (1) for forming the adhesive layer was applied to the release-treated surface of a separator film made of a polyethylene terephthalate film subjected to a release treatment ("PLZ-383030" obtained from Lintec Corporation) using an applicator so that the thickness after drying was 5 μm, and dried at 100 °C for 1 minute to produce an adhesive layer (adhesive sheet). Next, the surface of the obtained adhesive layer on the side opposite to the separator film was bonded to the release-treated surface of a separator film made of a polyethylene terephthalate film subjected to a release treatment ("PLR-381031" obtained from Lintec Corporation). Subsequently, ultraviolet rays were irradiated under the following conditions to produce an adhesive sheet (1). [UV Irradiation Conditions] Fusion UV lamp system (manufactured by Fusion UV Systems) H bulb used Accumulated light output: 250mJ / cm 2

[0297] 5. Preparation of adhesive sheet (2) [Preparation of acrylic resin solution (2)] A reaction vessel equipped with a condenser, nitrogen inlet, thermometer, and stirrer was charged with a mixed solution of 81.8 parts by mass of ethyl acetate, 90.0 parts by mass of butyl acrylate, 5.0 parts by mass of methyl acrylate, and 5.0 parts by mass of acrylic acid. The air inside the vessel was purged with nitrogen gas to remove oxygen, and the internal temperature was raised to 55°C. Subsequently, a solution of 0.15 parts by mass of azobisisobutyronitrile (polymerization initiator) dissolved in 10 parts by mass of ethyl acetate was added in its entirety. After the addition of the polymerization initiator, the internal temperature was maintained at 55°C for 1 hour. Then, ethyl acetate was continuously added to the reaction vessel at a rate of 17.3 parts by mass / hour while maintaining the internal temperature at 54-56°C. When the (meth)acrylic resin concentration reached 35% by mass, the addition of ethyl acetate was stopped, and the internal temperature was maintained at 55°C for a further 6 hours after the start of the ethyl acetate addition. Ethyl acetate was then added to adjust the (meth)acrylic resin concentration to 20% by mass, preparing acrylic resin solution (3). The resulting acrylic resin had a weight-average molecular weight Mw of 1.6 million and a molecular weight distribution Mw / Mn of 4.5. Mw and Mn were measured in terms of standard polystyrene using two Tosoh Corporation "TSKgel GMHHR-H(S)" columns connected in series in a GPC system, tetrahydrofuran as the 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.

[0298] [Preparation of Pressure-Sensitive Adhesive Layer-Forming Composition (2)] To 100 parts by mass of the solid content of the acrylic resin solution (2), 0.15 parts by mass of a crosslinking agent (manufactured by Tosoh Corporation: trade name "Coronate L" (a solution of a trimethylolpropane adduct of tolylene diisocyanate in ethyl acetate (solid content concentration 75% by mass)) was added on an active ingredient basis, and 0.2 parts by mass of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.: trade name "KBM-403") was added, and ethyl acetate was further added to bring the solid content concentration to 13% by mass, thereby obtaining a composition (2) for forming an adhesive layer.

[0299] The pressure-sensitive adhesive layer-forming composition (2) was applied using an applicator to the release-treated surface of a separator film made of release-treated polyethylene terephthalate film ("PLR-382190" available from Lintec Corporation) so that the thickness after drying would be 25 μm, and the composition was dried at 100° C. for 1 minute to produce a pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet). Next, the surface of the resulting pressure-sensitive adhesive layer opposite the separator film was bonded to the release-treated surface of a separator film made of release-treated polyethylene terephthalate film ("PET-251130" available from Lintec Corporation) to produce a pressure-sensitive adhesive sheet (2).

[0300] 6. Preparation of adhesive (1) [Preparation of adhesive layer-forming composition (1)] The following components were blended and mixed, and then degassed to prepare a composition (1) for forming an adhesive layer, which was used as the adhesive (1). (cationically polymerizable compound) 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Corporation): 70 parts by mass Neopentyl glycol diglycidyl ether (product name: EX-211, manufactured by Nagase ChemteX Corporation): 20 parts by mass 2-Ethylhexyl glycidyl ether (product name: EX-121, manufactured by Nagase ChemteX Corporation): 10 parts by mass (Photocationic polymerization initiator) Product name: CPI-100 (San-Apro Co., Ltd., 50% propylene carbonate solution): 4.5 parts by weight (actual solids content: 2.25 parts by weight) (Photosensitizing agent) 1,4-diethoxynaphthalene: 2 parts by mass 7. Preparation of Adhesive (2) An aqueous polyvinyl alcohol solution was prepared by dissolving 3 parts by mass of carboxyl-modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., product name: KL-318) in 100 parts by mass of water. A water-soluble polyamide epoxy resin (manufactured by Taoka Chemical Co., Ltd., product name: Sumirez Resin 650 (30), solid content concentration 30% by mass) was mixed with the resulting aqueous solution in a ratio of 1.5 parts by mass per 100 parts by mass of water to obtain adhesive (2).

[0301] 8. Preparation of Polarizing Plates [Fabrication of polarizer] A 30 μm-thick polyvinyl alcohol-based resin film (average degree of polymerization: approximately 2400, saponification degree: 99 mol% or more) was uniaxially stretched longitudinally by approximately 5 times by dry stretching and, while maintaining tension, was immersed in pure water at 60°C for 1 minute. The polyvinyl alcohol-based resin film was then immersed in an aqueous solution at 28°C with an iodine / potassium iodide / water mass ratio of 0.05 / 5 / 100 for 60 seconds. The polyvinyl alcohol-based resin 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. The polyvinyl alcohol-based resin film was then washed with pure water at 26°C for 20 seconds and then dried at 65°C. A 12 μm-thick polarizer was obtained in which iodine was adsorbed and aligned in the polyvinyl alcohol-based resin film. [Preparation of the first protective layer] The following films were prepared as the first protective layer. First protective layer A: triacetyl cellulose (TAC) film (KC2UA, manufactured by Konica Minolta, Inc., thickness 25 μm, thickness direction retardation value Rth=18 nm). First protective layer B: Triacetyl cellulose (TAC) film (manufactured by Konica Minolta, Inc., thickness 20 μm, in-plane retardation value at a wavelength of 590 nm: 1.2 nm, thickness direction retardation value at a wavelength of 590 nm: 1.3 nm)). First protective layer C: Cyclic polyolefin resin (COP) film (ZF14, manufactured by Zeon Corporation, thickness 23 μm) First protective layer D: acrylic resin film (OXIS (registered trademark), manufactured by Okura Kogyo Co., Ltd., thickness 40 μm, in-plane retardation value at a wavelength of 590 nm 1 nm, retardation value in the thickness direction −1 nm).

[0302] [Preparing the second protective layer] The second protective layer was a surface-treated protective layer (a cycloolefin polymer (COP) film (ZF-14, manufactured by Zeon Corporation, thickness 23 μm) coated with a surface treatment agent manufactured by Nippon Paper Industries Co., Ltd. to a thickness of 3 μm, resulting in a COP film with a surface treatment layer).

[0303] [Preparation of polarizing plates] The adhesive (2) prepared above was applied to one side of the polarizer obtained above, and a first protective layer A was attached thereto. The adhesive (2) prepared above was applied to the other side of the polarizer, and the side of the second protective layer opposite the surface treatment layer was attached thereto. This was dried at a temperature of 80°C for 5 minutes, thereby obtaining polarizing plate A having protective layers on both sides of the polarizer. Polarizing plates B to D were also obtained by the same procedure, except that first protective layer A was replaced with first protective layers B to D.

[0304] [Measurement of Martens Hardness of the Surface of the First Retardation Layer on the First Protective Layer Side] After peeling off the substrate from each of the substrate-attached first retardation films obtained above, the surface of each example facing the first protective layer was placed on a glass plate to obtain a measurement sample. Under an atmosphere of 23 ° C. temperature and 55% relative humidity, a load was applied to the surface of the first retardation layer side of the measurement sample using an ultra-microhardness tester (FISCHERSCOPE HM2000: manufactured by Fischer Instruments Co., Ltd.) at a pressure rate of 1 mN / 10 seconds, and then the Martens hardness was measured with a creep time (the time to maintain the 1 mN load) of 5 seconds, and the Martens hardness was defined as the Martens hardness of the surface of the first protective layer side of the first retardation layer.

[0305] [Measurement of Martens hardness of the first protective layer] Each first protective layer was attached to the pressure-sensitive adhesive layer (2) exposed by peeling off one separator film from the pressure-sensitive adhesive sheet (2). The other separator film attached to the pressure-sensitive adhesive layer (2) was then peeled off, and the exposed surface of the pressure-sensitive adhesive layer (2) was attached to a glass plate to obtain a measurement sample in which glass / pressure-sensitive adhesive layer (2) / first protective layer were laminated in this order. A load was applied to the surface of the first protective layer side of the measurement sample using an ultra-microhardness tester (FISCHERSCOPE HM2000, manufactured by Fischer Instruments Inc.) at a pressure rate of 20 mN / 10 seconds in an atmosphere of 23°C and 55% relative humidity. The Martens hardness was measured over a creep time (the time during which a 1 mN load was maintained) of 5 seconds, and this was taken as the Martens hardness of the first protective layer.

[0306] Example 1 The first protective layer side of the polarizing plate A (MD length 380 mm × TD length 180 mm) prepared above was subjected to corona treatment (800 W, 10 m / min, bar width 700 mm, 1 pass). Next, the adhesive (1) prepared above was applied to the first protective layer side of the polarizing plate using a coating machine (a bar coater manufactured by Daiichi Rika Co., Ltd.), and the first protective layer and the first retardation layer (1) side of the substrate-attached first retardation film (1) (MD length 380 mm × TD length 180 mm) were bonded using a bonding device ("LPA3301" manufactured by Fujipla Inc.). An ultraviolet irradiation device with a belt conveyor (using an "H bulb" manufactured by Fusion UV Systems) was used to apply light from the first retardation film (1) side at an irradiation intensity of 390 mW / cm in the UVA region. 2 , cumulative light intensity 420mJ / cm 2 So, in the UVB range, it is 400mW / cm 2 , cumulative light intensity 400mJ / cm 2 The adhesive (1) was cured by irradiating with ultraviolet light so as to obtain a laminate (A1) having a polarizing plate A and a first retardation layer (1). The thickness of the layer in which the adhesive (1) was cured (hereinafter also referred to as "first laminating layer") was measured and found to be 1.5 μm.

[0307] Next, the substrate of the substrate-attached first retardation film (1) was peeled from the laminate (A1) to expose the surface (the surface on the first retardation layer (1) side) and the pressure-sensitive adhesive layer (1) surface exposed by peeling one separator film from the pressure-sensitive adhesive sheet (1) (380 mm × 180 mm) prepared above were laminated together using an automatic laminator HALTEC, and then the other separator film was peeled off. Note that the alignment film was also peeled off when the substrate of the first retardation film was peeled off. The other separator film was peeled off to expose the pressure-sensitive adhesive layer (1) surface, and the second retardation layer surface of the substrate-attached second retardation film (1) (MD length 380 mm × TD length 180 mm) prepared above was laminated sheet by sheet using an automatic laminating machine HALTEC to obtain a laminate (B1) consisting of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / alignment film / substrate.

[0308] The substrate of the substrate-attached second retardation film (1) was peeled from the obtained laminate (B1), and the exposed surface (the surface on the second retardation layer side) was bonded to the pressure-sensitive adhesive layer (1) surface exposed by peeling one separator film from the pressure-sensitive adhesive sheet (1) (380 mm × 180 mm) prepared above using an automatic laminator HALTEC, and then the other separator film was peeled off. Note that the alignment film was also peeled off when the substrate of the second retardation film was peeled off. The other separator film was peeled off to expose the pressure-sensitive adhesive layer (1) surface, and the third retardation layer surface of the substrate-attached third retardation film (MD length 380 mm × TD length 180 mm) prepared above was laminated using an automatic laminating machine HALTEC, to obtain a laminate (C1) consisting of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / alignment film / substrate.

[0309] The substrate of the substrate-attached third retardation film was peeled off from the obtained laminate (C1) and the exposed surface (the surface on the third retardation layer side) and the pressure-sensitive adhesive sheet (2) (300 mm × 200 mm 380 mm × 180 mm) prepared above were peeled off and the pressure-sensitive adhesive layer (2) exposed was laminated using an automatic laminating machine HALTEC, and the second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film composed of a separator film was obtained. The alignment film was also peeled off along with peeling off the substrate of the third retardation film.

[0310] The separator film was peeled off from the optical laminate (1), and the exposed pressure-sensitive adhesive layer (2) was attached to glass. The in-plane retardation values ​​were measured using a KOBRA-WR manufactured by Oji Scientific Instruments. The in-plane retardation values ​​for light with wavelengths of 450 nm, 550 nm, and 650 nm were calculated using Cauchy's dispersion formula, which was 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. The resulting in-plane retardation values ​​were Re(450) = 115 nm, Re(550) = 140 nm, and Re(650) = 149 nm, and the relationship between the in-plane retardation values ​​at each wavelength was as follows: The in-plane retardation value for the third retardation at each wavelength was approximately 0, so it did not affect the optical properties. Re(450) / Re(550)=0.82 Re(650) / Re(550)=1.06 (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.)

[0311] Example 2 The first retardation layer (1) side of the substrate-attached first retardation film (1) (MD length 380 mm × TD length 180 mm) prepared above and the pressure-sensitive adhesive layer (1) side exposed by peeling off one separator film from the pressure-sensitive adhesive sheet (1) (380 mm × 180 mm) prepared above were laminated using an automatic laminator HALTEC, and then the other separator film was peeled off. The pressure-sensitive adhesive layer (1) side exposed by peeling off the other separator film and the second retardation layer side of the substrate-attached second retardation film (1) (MD length 380 mm × TD length 180 mm) prepared above were laminated using an automatic laminator HALTEC to obtain a laminate (A2) consisting of substrate / alignment film / first retardation layer (1) / adhesive layer (1) / second retardation layer (1) / alignment film / substrate. Next, the surface of the first protective layer of polarizing plate A was subjected to a corona treatment (800 W, 10 m / min, bar width 700 mm, 1 pass), and then the adhesive (1) prepared above was applied to the corona-treated surface using a coating machine (a bar coater manufactured by Daiichi Rika Co., Ltd.). Furthermore, the substrate on the substrate-attached first retardation film (1) side of the laminate (A2) (MD length 380 mm × TD length 180 mm) prepared above was peeled off, and the exposed surface was bonded to the first protective layer using a bonding device ("LPA3301" manufactured by Fujipla Inc.). The alignment film was also peeled off along with the peeling of the substrate of the first retardation film. An ultraviolet irradiation device with a belt conveyor (using an "H bulb" lamp manufactured by Fusion UV Systems) was used from the laminate (A2) side, and the irradiation intensity in the UVA region was 390 mW / cm. 2 , cumulative light intensity 420mJ / cm 2 So, in the UVB range, it is 400mW / cm 2 , cumulative light intensity 400mJ / cm 2 The adhesive layer (1) was cured by irradiating ultraviolet light so that the thickness of the layer was 1.5 μm. The thickness of the layer containing the cured adhesive (1) (hereinafter also referred to as the "first laminating layer") was measured.

[0312] Next, the substrate was peeled off from the laminate (B2) and the exposed surface (the surface on the first retardation layer side) was bonded to the pressure-sensitive adhesive sheet (1) (380 mm × 180 mm) prepared above and the exposed surface of the pressure-sensitive adhesive layer (1) was peeled off from one of the separator films using an automatic laminator HALTEC, and then the other separator film was peeled off. Note that the alignment film was also peeled off when the substrate of the second retardation film was peeled off. The other separator film was peeled off to expose the pressure-sensitive adhesive layer (1) surface, and the third retardation layer surface of the substrate-attached third retardation film (MD length 380 mm × TD length 180 mm) prepared above were laminated together using an automatic laminating machine HALTEC, to obtain a laminate (C2) consisting of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / alignment film / substrate.

[0313] The substrate of the third retardation film was peeled off from the obtained laminate (C2) and the exposed surface (the surface on the third retardation layer side) and the pressure-sensitive adhesive sheet (2) (380 mm × 180 mm) prepared above were peeled off and the pressure-sensitive adhesive layer was exposed. The sheet was laminated using an automatic laminator HALTEC, and the second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film. An optical laminate (2) with a separator film composed of the separator film was obtained. The alignment film was also peeled off together with the substrate of the third retardation film.

[0314] Example 3 An optical laminate (3) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (2) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film was obtained in the same manner as in Example 1, except that the substrate-attached first retardation film (1) was changed to a substrate-attached first retardation film (2).

[0315] Example 4 An optical laminate (4) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (3) / pressure-sensitive adhesive layer (1) / second retardation layer (2) / pressure-sensitive adhesive layer (2) / separator film was obtained in the same manner as in Example 1, except that the substrate-attached first retardation film (1) was changed to a substrate-attached first retardation film (3), the substrate-attached second retardation film (1) was changed to a substrate-attached second retardation film (2), and no substrate-attached third retardation film was laminated.

[0316] Example 5 An optical laminate (5) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (2) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film was obtained in the same manner as in Example 2, except that the substrate-attached first retardation film (1) was changed to a substrate-attached first retardation film (2).

[0317] Example 6 An optical laminate (6) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (3) / pressure-sensitive adhesive layer (1) / second retardation layer (2) / pressure-sensitive adhesive layer (2) / separator film was obtained in the same manner as in Example 2, except that the substrate-attached first retardation film (1) was changed to a substrate-attached first retardation film (3), the substrate-attached second retardation film (1) was changed to a substrate-attached second retardation film (2), and no substrate-attached third retardation film was laminated.

[0318] Example 7 Except for changing polarizing plate A to polarizing plate B, the same procedure as in Example 1 was repeated to obtain an optical laminate (7) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film.

[0319] Example 8 Except for changing polarizing plate A to polarizing plate B, the same procedure as in Example 2 was repeated to obtain an optical laminate (8) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film.

[0320] Example 9 An optical laminate (9) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first retardation layer (2) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film was obtained in the same manner as in Example 1, except that polarizing plate A was changed to polarizing plate B and that the first retardation film (1) with a substrate was changed to a first retardation film (2) with a substrate.

[0321] Example 10 An optical laminate (10) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first retardation layer (3) / pressure-sensitive adhesive layer (1) / second retardation layer (2) / pressure-sensitive adhesive layer (2) / separator film was obtained in the same manner as in Example 1, except that polarizing plate A was changed to polarizing plate B, the substrate-attached first retardation film (1) was changed to a substrate-attached first retardation film (3), the substrate-attached second retardation film (1) was changed to a substrate-attached second retardation film (2), and a substrate-attached third retardation film was not laminated.

[0322] Example 11 An optical laminate (11) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first retardation layer (2) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film was obtained in the same manner as in Example 2, except that polarizing plate A was changed to polarizing plate B and that the first retardation film (1) with a substrate was changed to a first retardation film (2) with a substrate.

[0323] Example 12 An optical laminate (12) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first retardation layer (3) / pressure-sensitive adhesive layer (1) / second retardation layer (2) / pressure-sensitive adhesive layer (2) / separator film was obtained in the same manner as in Example 2, except that polarizing plate A was changed to polarizing plate B, the substrate-attached first retardation film (1) was changed to a substrate-attached first retardation film (3), the substrate-attached second retardation film (1) was changed to a substrate-attached second retardation film (2), and a substrate-attached third retardation film was not laminated.

[0324] Example 13 An optical laminate (13) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first retardation layer (4) / pressure-sensitive adhesive layer (1) / second retardation layer (2) / pressure-sensitive adhesive layer (2) / separator film was obtained in the same manner as in Example 1, except that polarizing plate A was changed to polarizing plate B, the substrate-attached first retardation film (1) was changed to a substrate-attached first retardation film (4), the substrate-attached second retardation film (1) was changed to a substrate-attached second retardation film (2), and a substrate-attached third retardation film was not laminated.

[0325] Example 14 Except for changing polarizing plate A to polarizing plate C, the same procedure as in Example 1 was repeated to obtain an optical laminate (14) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer C / adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film.

[0326] Example 15 Except for changing polarizing plate A to polarizing plate C, the same procedure as in Example 2 was repeated to obtain an optical laminate (15) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer C / adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film.

[0327] Example 16 The first protective layer and the first retardation film (1) were bonded not with an adhesive (1) but with the first protective layer and the pressure-sensitive adhesive sheet (1) (380 mm × 180 mm) by peeling one separator film from the pressure-sensitive adhesive layer (1) surface exposed by sheet bonding using an automatic laminator HALTEC, and then the other separator film was peeled off, and the exposed pressure-sensitive adhesive layer (1) surface and the first retardation layer surface of the first retardation film (1) were bonded sheet by sheet using an automatic laminator HALTEC. Except for this, an optical laminate (16) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / pressure-sensitive adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film was obtained.

[0328] Example 17 The first protective layer and the substrate-attached first retardation film (1) were bonded not with an adhesive (1) but with a HALTEC automatic laminator to the first protective layer and the pressure-sensitive adhesive sheet (1) (380 mm × 180 mm) by peeling one separator film from the pressure-sensitive adhesive layer (1) surface exposed. Then, the other separator film was peeled off, and the exposed pressure-sensitive adhesive layer (1) surface and the first retardation layer surface of the first retardation film (1) were bonded together using a HALTEC automatic laminator. The same procedure as in Example 2 was repeated except that a separator film-attached optical laminate (17) consisting of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / pressure-sensitive adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (1) / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film was obtained.

[0329] Example 18 The bonding of the substrate-attached first retardation film and the substrate-attached second retardation film, and the bonding of the substrate-attached second retardation film and the substrate-attached third retardation film are carried out by applying the adhesive (1) prepared above to the surfaces (the surfaces on the first retardation layer (1) side and the second retardation layer (1) side) exposed by peeling off the substrates of the substrate-attached first retardation film and the substrate-attached second retardation film using a coating machine (a bar coater manufactured by Daiichi Rika Co., Ltd.), instead of using the pressure-sensitive adhesive sheet (1), to bond the first retardation layer (1) side of the first retardation film and the second retardation layer side of the second retardation film, The second retardation layer (1) surface of the two-phase retardation film and the third retardation layer surface of the third retardation film were bonded using a bonding device ("LPA3301" manufactured by Fujipla Co., Ltd.) in the same manner as in Example 1, except that a separator film-attached optical laminate (18) consisting of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (1) / adhesive layer (1) (thickness 1.5 μm) / second retardation layer (1) / adhesive layer (1) (thickness 1.5 μm) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film was obtained.

[0330] Example 19 The bonding of the substrate-attached first retardation film and the substrate-attached second retardation film, and the bonding of the substrate-attached second retardation film and the substrate-attached third retardation film are carried out by peeling off the substrates of the substrate-attached first retardation film and the substrate-attached second retardation film, and applying the adhesive (1) prepared above to the exposed surfaces (the surfaces on the first retardation layer (1) side and the second retardation layer (1) side) using a coating machine (a bar coater manufactured by Daiichi Rika Co., Ltd.), instead of using the pressure-sensitive adhesive sheet (1), to bond the first retardation layer (1) side of the first retardation film and the second retardation layer side of the second retardation film, and the second retardation layer (1) side. The second retardation layer (1) surface of the film and the third retardation layer surface of the third retardation film were bonded using a bonding device ("LPA3301" manufactured by Fujipla Co., Ltd.) in the same manner as in Example 2, except that the second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (1) / adhesive layer (1) (thickness 1.5 μm) / second retardation layer (1) / adhesive layer (1) (thickness 1.5 μm) / third retardation layer / pressure-sensitive adhesive layer (2) / pressure-sensitive adhesive layer (2) / separator film. An optical laminate (19) with a separator film composed of these was obtained.

[0331] Example 20 An optical laminate (20) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (3) / alignment film / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film was obtained in the same manner as in Example 1, except that the substrate-attached second retardation film (1) was changed to a substrate-attached second retardation film (3) and the alignment film was not peeled off when the substrate of the substrate-attached second retardation film was peeled off.

[0332] Example 21 An optical laminate (21) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first retardation layer (1) / pressure-sensitive adhesive layer (1) / second retardation layer (3) / alignment film / pressure-sensitive adhesive layer (1) / third retardation layer / pressure-sensitive adhesive layer (2) / separator film was obtained in the same manner as in Example 2, except that the substrate-attached second retardation film (1) was changed to a substrate-attached second retardation film (3) and the alignment film was not peeled off when the substrate of the substrate-attached second retardation film was peeled off.

[0333] (Comparative Example 1) Polarizing plate A was changed to polarizing plate B; the substrate-attached first retardation film (1) was changed to the substrate-attached first retardation film (5); the substrate-attached second retardation film (1) was changed to the substrate-attached second retardation film (4); no substrate-attached third retardation film was laminated; the first protective layer and the substrate-attached first retardation film (1) were bonded not with adhesive (1) but with an automatic laminator HALTEC by peeling one separator film from the first protective layer and an adhesive sheet (1) (380 mm × 180 mm) to expose the adhesive layer (1) surface, and then the other separator film was peeled off and the exposed adhesive layer (1) surface and the first retardation layer surface of the first retardation film (1) were bonded with an automatic laminator HALTEC by sheet; and the first retardation film and the second retardation film were bonded with an adhesive sheet (1). Instead, the adhesive (1) prepared above was applied to the surface (the surface on the first retardation layer (1) side) exposed by peeling off the substrate of the first retardation film using a coating machine (a bar coater manufactured by Daiichi Rika Co., Ltd.), and the first retardation layer (1) surface of the first retardation film and the second retardation layer surface of the second retardation film were bonded using a laminating device ("LPA3301" manufactured by Fujipla Inc.), and the alignment film was not peeled off when the substrates of the substrate-attached first retardation film and the substrate-attached second retardation film were peeled off. Except for this, an optical laminate (R1) with a separator film composed of second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / pressure-sensitive adhesive layer (1) / alignment film / first retardation layer (5) / adhesive layer (1) (thickness 1.5 μm) / second retardation layer (4) / alignment film / pressure-sensitive adhesive layer (2) / separator film was obtained.

[0334] [evaluation] (deformation defects) A test laminate was obtained in the same manner as above, except that the first retardation film was attached to the prepared optical laminate with a separator film so that the slow axis of the first retardation film was at an angle of 45° clockwise from the viewing side with respect to the absorption axis of the polarizer. The separator film of the obtained test laminate was peeled off, and the laminate was attached to alkali-free glass (manufactured by Corning, Eagle XG) to prepare a test laminate sample.

[0335] The separator film side surface of the prepared optical laminate with separator film was observed by reflecting fluorescent light, and any locations where minute deformations were visible were marked. The marking positions were observed through transmission using an optical microscope (Olympus Corporation, product name BX53M), and markings where minute foreign matter measuring 10 μm to 20 μm in size were selected. The selected marking positions were analyzed for cross-section using a scanning white light interference microscope, VS1000 (Hitachi High-Tech Science Corporation), and unevenness was inspected for marking positions where minute foreign matter was confirmed in the bonding layer between the first protective layer and the first retardation layer.

[0336] The unevenness inspection was performed in a darkroom with a backlight (LED Viewer 5000A4 manufactured by Shinkosha Co., Ltd.) set to normal mode (11,800 lux) and the laminate sample to be inspected placed on the backlight with the second protective layer side facing up (the second protective layer facing the light source). The separator film was peeled off and the optical laminate to be inspected for unevenness was placed so that the exposed bonding layer faced the backlight. At this time, the absorption axis of the optical laminate to be inspected for unevenness was parallel to the absorption axis of the laminate sample to be inspected. Unevenness was observed at the marking position where foreign matter was confirmed in the first bonding layer between the first protective layer and the first retardation layer in the layer cross-section analysis. Unevenness was evaluated according to the following criteria. The evaluation results are shown in each table. A: No visible unevenness. B: Virtually no unevenness is visible.

[0337] (crack resistance) The separator film was removed from the prepared optical laminates with separator film, and the exposed laminating layer was then bonded to a glass plate. A thermal shock resistance test was then performed. The tip of an Erichsen pen (Erichsen, Model No. 318) set to a load of 10 N was pressed against the surface of the polarizer in the optical laminate opposite the glass plate side to form a starting point. Two other similar starting points (a total of three) were placed at equal intervals. A thermal shock test was then performed using a TSA-303EL-W (ESPEC Corp.) pen, consisting of a cycle of 30 minutes at -20°C and 30 minutes at 60°C. Before the thermal shock test, the length of cracks generated at each starting point by pressing the Erichsen pen against the polarizer surface in the optical laminate was measured, and the average crack length (mm) was calculated. Crack resistance was evaluated according to the following criteria. The evaluation results are shown in the tables. A+: The crack length is 1 mm or less. A: The crack length is more than 1 mm and less than 3 mm. B: The crack length is more than 3 mm and 5 mm or less. C: The crack length is more than 5 mm.

[0338] (Scratch resistance) In the process of producing each optical laminate with a separator film, the peeling interface state on the first retardation film side when peeling the substrate from the first retardation film was visually observed. The peeling speed when peeling the substrate was 30 m / min. The evaluation results are shown in each table. A+: No scratches were found. A: Almost no damage was found. B: Scratches were observed in some parts of the peeled interface.

[0339] (oblique color difference) The separator film was peeled off from the prepared optical laminate with separator film, and the exposed laminating layer was bonded to an inorganic glass plate (manufactured by Corning, product name: Eagle XG) to obtain a glass plate with a circular polarizer. The obtained glass plate with a circular polarizer was measured for reflection hue a from an inclination angle of 50 degrees (a direction of 50 degrees relative to the thickness direction of the circular polarizer) using a display evaluation system DMS803 (manufactured by Instrument Systems GmbH). * and b * The measurement sample was rotated within the sample plane while measuring the reflection hue a * and b * a * -b * The hue diagram (color shift) was obtained by plotting the data on a coordinate system. During the measurement, the glass plate with the circular polarizer obtained above was placed on a glass plate (thickness 0.7 mm, Corning "Eagle XG") reflector (reflectance: 96% or more, diffuse reflectance: 9% or less) with the second protective layer side facing up, and the layer structure of reflector / air / glass plate / optical laminate was used as the measurement sample. From the obtained hue diagram, a * The difference between the maximum and minimum values ​​of Δa * , b * The difference between the maximum and minimum values ​​of Δb * As Δa * b * was calculated using the following formula and judged into the following categories. Δa * b * =(Δa * )×(Δb * ) A:Δa * b * is less than 45. B:Δa * b * is 45 or more. [Table 1]

[0340] [Table 2]

[0341]

Table 3

[0342]

Table 4

Claims

1. A first protective layer, a first attaching layer, and a first retardation film are provided, the first protective layer and the first retardation film are bonded to each other via the first bonding layer, The first retardation film includes a first retardation layer but does not include a first alignment layer, or includes a first retardation layer and a first alignment layer, The Martens hardness of the surface of the first retardation layer on the side of the first protective layer is 100 N / mm ２ That's all, An optical laminate, wherein the ratio of the Martens hardness of the surface of the first retardation layer on the first protective layer side to the Martens hardness of the first protective layer is 1.5 or more.

2. The optical laminate according to claim 1 , wherein the first retardation layer is a cured layer of a polymerizable liquid crystal compound.

3. The optical laminate according to claim 1 or 2, wherein the first retardation film includes the first retardation layer but does not include the first alignment layer.

4. The Martens hardness of the surface of the first retardation layer on the side of the first protective layer is 170 N / mm ２ The optical laminate according to claim 1 or 2.

5. The Martens hardness of the surface of the first retardation layer on the side of the first protective layer is 250 N / mm ２ The optical laminate according to claim 1 or 2, wherein:

6. The optical laminate according to claim 1 or 2, wherein the Martens hardness of the surface of the first retardation layer on the first protective layer side is greater than the Martens hardness of the surface of the first retardation layer opposite to the first protective layer.

7. The Martens hardness of the first protective layer is 80 N / mm ２ The optical laminate according to claim 1 or 2.

8. The Martens hardness of the first protective layer is 140 N / mm ２ The optical laminate according to claim 1 or 2, wherein:

9. The optical laminate according to claim 1 or 2, wherein the first protective layer has a thickness direction retardation value Rth of 10 nm or more.

10. The optical laminate according to claim 1 or 2, wherein the ratio is 2.0 or more.

11. The optical laminate according to claim 1 or 2, wherein the ratio is 3.5 or less.

12. The optical laminate according to claim 1 or 2, further comprising a polarizer layer.

13. Further provided with a second attachment layer and a second retardation film, the first retardation film and the second retardation film are bonded to each other via the second bonding layer, The optical laminate according to claim 1 or 2, wherein the second retardation film comprises a second retardation layer but does not comprise a second alignment layer, or comprises a second retardation layer and a second alignment layer.

14. The optical laminate according to claim 13, wherein the optical laminate including the first retardation film, the second bonding layer, and the second retardation film satisfies the relationships of the following formulas (1) and (2). 100≦Re(550)≦180 (1) Re(450) / Re(550)≦1.0 (2) [In formula (1) and formula (2), Re(450) represents an in-plane retardation value for light having a wavelength of 450 nm, Re(550) represents the in-plane retardation value for light with a wavelength of 550 nm.]

15. The optical laminate according to claim 13, wherein the second retardation film includes the second retardation layer but does not include the second alignment layer.

16. The optical laminate according to claim 13 , wherein the second attaching layer is a cured layer of an active energy ray-curable composition.

17. Preparing a first retardation film including a first retardation layer and a first alignment layer; and providing a first protective layer on a surface of the first retardation layer side of the first retardation film via a first attachment layer to obtain a first optical laminate, The Martens hardness of the surface of the first retardation layer on the side of the first protective layer is 100 N / mm ２ That's all, A method for producing an optical laminate, wherein a ratio of the Martens hardness of the surface of the first retardation layer on the first protective layer side to the Martens hardness of the first protective layer is 1.5 or more.

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