Optical laminate and method for manufacturing an optical laminate

Abstract

To provide an optical laminate that suppresses deformation defects while possessing sufficient crack resistance even under thermal shock conditions. [Solution] The invention comprises a first protective layer, a first bonding layer, and a first phase difference film, wherein the first protective layer and the first phase difference film are bonded together via the first bonding layer, and the first phase difference film includes the first phase difference layer but does not include the first orientation layer, or includes the first phase difference layer and the first orientation layer, and the Martens hardness of the surface of the first phase difference layer on the first protective layer side is 100 N / mm². 2 The above describes an optical laminate in which the ratio of the Martens hardness of the surface on the first protective layer side of the first phase difference layer to the Martens hardness of the first protective layer is 1.5 or greater.

Description

[Technical Field]

[0001] This invention relates to an optical laminate and a method for manufacturing an optical laminate. [Background technology]

[0002] A circular polarizer is an optical laminate in which a polarizer and a phase difference film are laminated together. For example, it is used in devices that display images in a planar state, such as organic EL image display devices, to prevent light reflection at the electrodes that make up the device.

[0003] A circular polarizing plate can be manufactured, for example, by bonding a polarizing plate and a phase difference film with an adhesive, but deformation defects and unevenness may occur due to minute foreign matter mixed into the adhesive. To solve this problem, Patent Document 1 investigates how to suppress the occurrence of unevenness caused by minute foreign matter by increasing the DMT elastic modulus of the phase difference layer to a certain extent. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-152763 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, increasing the DMT modulus of the phase difference layer and hardening the phase difference layer to suppress deformation defects sometimes resulted in insufficient crack resistance under thermal shock conditions. Therefore, the present invention aims to provide an optical laminate that suppresses deformation defects while having sufficient crack resistance even under thermal shock conditions. Furthermore, the present invention aims to provide a method for manufacturing such an optical laminate. [Means for solving the problem]

[0006] One aspect of this disclosure includes, for example, the following [1] to

[17] . [1] comprising a first protective layer, a first laminating layer, and a first phase difference film, The first protective layer and the first phase difference film are bonded together via the first bonding layer. The first phase difference film includes a first phase difference layer but does not include a first orientation layer, or includes a first phase difference layer and a first orientation layer. The Martens hardness of the surface on the first protective layer side of the first phase difference layer is 100 N / mm². 2 That's all. An optical laminate in which the ratio of the Martens hardness of the surface on the first protective layer side of the first phase difference layer to the Martens hardness of the first protective layer is 1.5 or more. [2] The optical laminate according to [1], wherein the first phase difference layer is a cured product layer of a polymerizable liquid crystal compound. [3] The optical laminate according to [1] or [2], wherein the first phase difference film includes the first phase difference layer but does not include the first orientation layer. [4] The Martens hardness of the surface of the first protective layer on the first phase difference layer is 170 N / mm². 2 The optical laminate described above is one of the following [1] to [3]. [5] The Martens hardness of the surface on the first protective layer side of the first phase difference layer is 250 N / mm² 2 The optical laminate described in any one of the following [1] to [4]. [6] The optical laminate according to any one of [1] to [5], wherein the Martens hardness of the surface of the first phase difference layer on the side of the first protective layer is greater than the Martens hardness of the surface of the first phase difference layer on the side opposite to the first protective layer. [7] The Martens hardness of the first protective layer is 80 N / mm². 2 The optical laminate described in any one of [1] to [6] above. [8] The Martens hardness of the first protective layer is 140 N / mm² 2 The optical laminate described in any one of the following [1] to [7]. [9] The optical laminate according to any one of [1] to [8], wherein the phase difference value Rth in the thickness direction of the first protective layer is 10 nm or more.

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

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

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

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

[11] , further comprising a polarizer layer.

[13] Further comprising a second laminating layer and a second phase difference film, The first phase difference film and the second phase difference film are bonded together via the second bonding layer. The optical laminate according to any one of [1] to

[12] , wherein the second phase difference film includes a second phase difference layer but does not include a second orientation layer, or includes a second phase difference layer and a second orientation layer.

[14] The optical laminate according to

[13] , comprising the first phase difference film, the second lamination layer, and the second phase difference film, wherein the relationship between the following formulas (1) and (2) is satisfied. 100 ≤ Re(550) ≤ 180 (1) Re(450) / Re(550)≦1.0 (2) [In equations (1) and (2), Re(450) represents the in-plane phase difference value for light with a wavelength of 450 nm. Re(550) represents the in-plane phase difference value for light with a wavelength of 550 nm.

[15] The optical laminate according to

[13] or

[14] , wherein the second phase difference film includes the second phase difference layer but does not include the second orientation layer.

[16] The optical laminate according to any one of

[13] to

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

[17] A step of preparing a first phase difference film including a first phase difference layer and a first orientation layer, The process includes providing a first protective layer on the surface of the first phase difference layer side of the first phase difference film via a first lamination layer to obtain a first optical laminate, The Martens hardness of the surface on the first protective layer side of the first phase difference layer is 100 N / mm². 2 That's all. A method for manufacturing an optical laminate, wherein the ratio of the Martens hardness of the surface of the first phase difference 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 has sufficient crack resistance even under a thermal shock environment while suppressing deformation defects. Furthermore, according to the present invention, it is possible to provide a method for manufacturing such an optical laminate. [Modes for carrying out the invention]

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

[0009] In this specification, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. "A or greater" in a numerical range means A and the range exceeding A. "A or less" in a numerical range means A and the range less than A. In numerical ranges described stepwise in this specification, the upper or lower limit of a numerical range in one step can be arbitrarily combined with the upper or lower limit of a numerical range in another step. In numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. "A or B" means that either A or B may be included, or both may be included. Unless otherwise specified, the materials exemplified in this specification may be used individually or in combination of two or more. The content of each component in a composition means the total amount of multiple substances present in the composition if multiple substances corresponding to each component exist in the composition, unless otherwise specified. In this specification, (meth)acrylic resin means either acrylic resin or 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 comprises a first protective layer, a first bonding layer, and a first phase difference film. In the optical laminate, the first protective layer and the first phase difference film are bonded together via the first bonding layer. The first phase difference film may include the first phase difference layer but may not include the first alignment layer. The first phase difference film may include both the first phase difference layer and the first alignment layer. The Martens hardness of the surface of the first phase difference layer on the side facing the first protective layer is 100 N / mm². 2 In summary, the ratio of the Martens hardness of the surface on the first protective layer side of the first phase difference layer to the Martens hardness of the first protective layer is 1.5 or greater.

[0011] In such an optical laminate, the Martens hardness of the surface on the first protective layer side of the first phase difference layer is 100 N / mm². 2As described above, by having a ratio of the Martens hardness of the surface of the first phase difference layer on the first protective layer side to the Martens hardness of the first protective layer of the first phase difference layer of 1.5 or more, deformation defects can be suppressed while maintaining sufficient crack resistance even under thermal shock conditions. The reason for this effect is not entirely clear, but the inventors speculate as follows. First, if minute foreign matter is mixed into the first bonding layer, local deformation occurs in the first protective layer and the first phase difference layer around the first bonding layer containing the minute foreign matter, and this deformation defect in the first phase difference layer may be visible as unevenness in the optical laminate. However, if the Martens hardness of the first protective layer side of the first phase difference layer is sufficiently high, even if minute foreign matter is mixed into the first bonding layer, the degree of deformation of the first phase difference layer will be small, making it possible to suppress unevenness in the optical laminate caused by deformation defects in the first phase difference layer. Furthermore, if the ratio of the Martens hardness of the surface on the first protective layer side of the first phase difference layer to the Martens hardness of the first protective layer is large, the deformation of the first phase difference layer side when minute foreign matter is mixed into the first bonding layer will be reduced, and deformation defects in the laminate will be suppressed. Moreover, in the operating environment of a display device in which optical laminates are stacked, temperature changes will cause dimensional changes such as expansion and contraction in the phase difference film, other optical films, and bonding layers that constitute the optical laminate, and as a result, cracks are likely to occur when stress is applied to the thin films (e.g., alignment film layer and phase difference layer) that constitute the laminate. However, if the ratio of the Martens hardness of the surface on the first protective layer side of the first phase difference layer to the Martens hardness of the first protective layer is large enough, the flexibility of the optical laminate as a whole will be improved, and the occurrence of cracks can be suppressed against deformation such as dimensional changes due to thermal shock environments (severe temperature changes). In particular, the alignment film layer has low breaking strength and is prone to cracking when stress is applied. Therefore, a configuration that does not include an orientation film layer is more preferable because the occurrence of cracks is suppressed as there is no layer that serves as a crack initiation point.

[0012] <First protective layer> The first protective layer has the function of protecting the surface of the linear polarizer, which will be described later. The linear polarizer and the first protective layer may be directly laminated to each other. Here, "directly laminated" includes the embodiment in which the first protective layer is laminated to the linear polarizer by the self-adhesion of the first protective layer, and the embodiment in which it is laminated via an adhesive layer or a tackifying layer. To improve adhesion with the linear polarizer, the first protective layer may be subjected to surface treatment (e.g., corona treatment, etc.), and a thin layer such as a primer layer (also called an easy-adhesion layer) may be formed on it.

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

[0014] The first protective layer may be a curable resin layer containing a cured product of a curable resin. Examples of the curable resin include thermosetting resins and active energy ray curable resins, such as (meth)acrylic resins, epoxy resins, oxetane resins, urethane resins, (meth)acrylic urethane resins, melamine resins, and the like. The curable resin layer containing a cured product of a curable resin can be formed by applying a composition containing a curable resin onto a support substrate, drying it if necessary, and then applying heat or irradiating active energy rays such as visible light, ultraviolet rays, infrared rays, X-rays, α-rays, β-rays, γ-rays, and electron beams. The obtained curable resin layer with the support substrate is bonded to the linear polarizer through an adhesive layer if necessary, and then the support substrate is peeled off and removed, whereby a curable resin layer as a protective layer can be laminated on the linear polarizer.

[0015] From the viewpoint of suppressing deformation defects and having sufficient crack resistance even in a heat shock environment, the ratio of the Martens hardness of the surface on the first protective layer side in the first retardation layer to the Martens hardness of the first protective layer is 1.5 or more. From the viewpoint of more easily suppressing deformation defects, the 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 the crack resistance in a heat shock environment, the ratio is preferably 4.5 or less, more preferably 4.0 or less, still more preferably less than 3.5, 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] From the viewpoint of more easily suppressing deformation defects, the Martens hardness of the first protective layer is preferably 50 N / mm 2 or more, more preferably 80 N / mm 2 or more, and particularly preferably 100 N / mm 2 or more. From the viewpoint of further improving the crack resistance in a heat shock environment, the Martens hardness of the first protective layer is preferably 170 N / mm 2 or less, more preferably 140 N / mm 2 or less, and still more preferably 120 N / mm 2The following is particularly preferred: 110 N / mm 2 The following is even more preferable.

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

[0018] The phase difference value Rth in the thickness direction of the first protective layer is preferably 10 nm or more, and more preferably 15 nm or more, from the viewpoint of suppressing changes in the hue of reflected ambient light when viewed from an oblique direction. The phase difference value Rth in the thickness direction of the first protective layer may be 25 nm or less, or 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. Stretching methods include uniaxial stretching and biaxial stretching. Stretching directions include the machine flow direction (MD) of the unstretched film, a direction perpendicular to the machine flow direction (MD) (TD), and a direction oblique to the machine flow direction (MD). Biaxial stretching may be simultaneous biaxial stretching, where the film is stretched in two directions simultaneously, or sequential biaxial stretching, where the film is stretched in one direction first and then in another. Stretching can be performed, for example, by using two or more pairs of nip rolls with a high peripheral speed on the exit side to stretch the film longitudinally (machine flow direction: MD), or by gripping both ends of the unstretched film with chucks and spreading it in a direction perpendicular to the machine flow direction (TD). In this process, the phase difference value and wavelength dispersion can be controlled by adjusting the film thickness or the stretching ratio. Furthermore, the wavelength dispersion value can be controlled by adding a wavelength dispersion modifier to the resin.

[0021] The first protective layer may contain any suitable additives depending on the purpose. Examples of additives include: antioxidants such as hindered phenol, phosphorus, and sulfur-based antioxidants; stabilizers such as light stabilizers, ultraviolet absorbers, weather stabilizers, and heat stabilizers; reinforcing materials such as glass fibers and carbon fibers; near-infrared absorbers; flame retardants such as tris(dibromopropyl) phosphate, triallyl phosphate, and antimony oxide; antistatic agents such as anionic, cationic, and nonionic surfactants; colorants such as inorganic pigments, organic pigments, and dyes; organic and inorganic fillers; resin modifiers; plasticizers; lubricants; and phase difference reducers. The types, combinations, and amounts of additives included can be appropriately set according to the purpose and desired properties.

[0022] To impart desired surface optical properties or other characteristics, a coating layer (surface treatment layer) can be provided on the outer surface of the first protective layer. The surface treatment layer includes, for example, a hard coat layer, an anti-glare layer, an anti-reflective layer, an anti-static layer, and an anti-fouling 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 side of the first protective layer or on both sides.

[0023] The hard coat layer has the function of increasing the surface hardness of the first protective layer and is provided for purposes such as preventing surface scratches. Preferably, the hard coat layer has a pencil hardness of H or a harder value as measured by the pencil hardness test specified in JIS K 5600-5-4:1999 "General test methods for paints - Part 5: Mechanical properties of coatings - Section 4: Scratch hardness (pencil method)" (measured by placing an optical film with a hard coat layer on a glass plate).

[0024] The materials used to form the hard coat layer are generally those that harden with heat or light. Examples include organic hard coat materials such as organic silicones, melamines, epoxys, (meth)acrylics, and urethane (meth)acrylates, and inorganic hard coat materials such as silicon dioxide. Among these, urethane (meth)acrylate or polyfunctional (meth)acrylate hard coat materials are preferred because they have good adhesion to the first protective layer and excellent productivity.

[0025] The hard coat layer may optionally contain various fillers for the purpose of adjusting the refractive index, improving the flexural modulus, stabilizing the volume shrinkage rate, and further improving heat resistance, antistatic properties, and anti-glare properties. The hard coat layer may also further contain additives such as antioxidants, UV absorbers, light stabilizers, antistatic agents, leveling agents, and defoamers.

[0026] The hard coat layer may contain additives to further improve its strength. The additives are not particularly limited and include inorganic fine particles, organic fine particles, or 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 cutting. Preferably, the thickness of the hard coat layer is 3 μm to 7 μm.

[0027] The anti-glare layer is a layer having a fine uneven surface, and is preferably formed using the hard coat material described above.

[0028] An anti-glare layer having a fine uneven surface can be formed by a method of creating an uneven surface based on the fine particles by forming a coating film containing fine particles on a stretched film; or by a method of forming a coating film containing or not containing fine particles on a stretched film, and then pressing it against a mold (roll, etc.) with an uneven surface to transfer the uneven shape (also called the embossing method).

[0029] The anti-reflective layer is a layer that reduces the reflection of external light from the surface of the first protective layer for the observer of the first protective layer, and its reflectivity for visible light may be 1.5% or less. Such an anti-reflective layer with a reflectivity 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 Japanese Patent Application Publication No. 2021-6929. By adjusting these refractive indices and the thickness of each layer, the reflected light from each layer can be weakened by each other, resulting in an excellent anti-reflective function.

[0030] As will be described in detail later, it is preferable to manufacture an anti-reflective layer consisting of a high refractive index layer and a low refractive index layer using a coating composition capable of forming both the high refractive index layer and the low refractive index layer, because the operation is extremely simple. Here is an example of a coating composition capable of forming both the high refractive index layer and the low refractive index layer. Such a coating composition is liquid and contains a suitable curable resin and, if necessary, additives.

[0031] A coating-type composition capable of forming a high refractive index layer (a composition for forming a high refractive index layer) is, for example, obtained by dissolving a curable resin such as urethane acrylate and an initiator (photopolymerization initiator) such as acetophenone-based, benzophenone-based, benzyldimethylketal-based, α-hydroxyalkylphenone-based, α-aminoalkylphenone-based, or thioxanthone-based solvent. To improve coatability, the coating-type composition may also contain a leveling agent, preferably a fluorine-based leveling agent.

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

[0033] The coating compositions that can form the high-refractive-index layer and the low-refractive-index layer mentioned here are just examples, and it is preferable to optimize the high-refractive-index layer-forming composition and the low-refractive-index layer-forming composition, respectively, according to the characteristics of the anti-reflective layer to be formed.

[0034] The anti-reflective layer may, for example, include a low refractive index layer. Alternatively, it may be a multilayer structure further comprising a high refractive index layer and / or a medium refractive index layer between the first protective layer and the low refractive index layer.

[0035] A low refractive index layer can be formed by applying a coating solution containing a light-transmitting resin such as a cured product of the aforementioned curable resin or a metal alkoxide polymer, and inorganic particles, and then curing the coating layer as needed. Examples of inorganic particles include low refractive index particles such as LiF (refractive index 1.4), MgF (refractive index 1.4), 3NaF·AlF (refractive index 1.4), AlF (refractive index 1.4), and Na3AlF6 (refractive index 1.33), as well as hollow silica particles.

[0036] The antistatic layer is provided to impart conductivity to the surface of the first protective layer and to suppress the effects of static electricity. For example, to form the antistatic layer, a resin composition containing a conductive substance (antistatic agent) can be applied to the first protective layer. For example, by including an antistatic agent in the hard coat material used to form the hard coat layer described above, an antistatic hard coat layer can be formed.

[0037] The antifouling layer is provided to impart water repellency, oil repellency, sweat resistance, and antifouling properties. A suitable material for forming the antifouling layer is a fluorine-containing organic compound. Examples of fluorine-containing organic compounds include fluorocarbons, perfluorosilanes, and polymer compounds thereof. Depending on the material to be formed, the antifouling layer can be formed using physical vapor deposition methods such as vapor deposition or sputtering, chemical vapor deposition methods, or wet coating methods. The average thickness of the antifouling layer may be about 1 to 50 nm, and is preferably 3 to 35 nm.

[0038] <First lamination layer> The first bonding layer is suitably used when bonding the optical laminate to another substrate. The first bonding layer may be an adhesive layer (e.g., a pressure-sensitive adhesive layer) or an adhesive layer. From the viewpoint of crack resistance, the first bonding layer is preferably a cured layer of an active energy ray curable composition (active energy ray curable 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) The adhesive composition used to form the adhesive layer can be any conventionally known adhesive composition with excellent optical transparency, without any particular limitations. For example, adhesive compositions having a base polymer such as acrylic resin, urethane resin, silicone resin, or polyvinyl ether resin can be used. Active energy ray curable adhesive compositions and thermosetting adhesive compositions may also be used. Among these, adhesive compositions using acrylic resin as the base polymer, which have excellent transparency, adhesive strength, re-peelability, weather resistance, and heat resistance, are preferred.

[0040] The 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 adhesive composition is preferably a polymer (hereinafter also referred to as "(meth)acrylic ester polymer") whose main component is a structural unit derived from an alkyl (meth)acrylate ester represented by the following formula (I) (hereinafter also referred to as "structural unit (I)"). (For example, containing 50 parts by mass or more per 100 parts by mass of structural units of the (meth)acrylic resin.

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

[0043] Examples of (meth)acrylic acid esters 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 include octyl (meth)acrylate, i-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n- and i-nonyl (meth)acrylate, n-decyl (meth)acrylate, i-decyl (meth)acrylate, n-dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobolonyl (meth)acrylate, stearyl (meth)acrylate, and t-butyl (meth)acrylate. Specific examples of alkoxy group-containing alkyl acrylates include 2-methoxyethyl (meth)acrylate and ethoxymethyl (meth)acrylate. Among these, it is preferable to include n-butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate, and particularly preferable to include n-butyl (meth)acrylate.

[0044] (Meth)acrylic acid ester polymers may contain structural units derived from monomers other than structural unit (I). The structural units derived from other monomers may be one type or two or more types. Other monomers that (meth)acrylic acid ester polymers may contain include monomers having polar functional groups, monomers having aromatic groups, and acrylamide monomers.

[0045] Examples of monomers having polar functional groups include (meth)acrylates having polar functional groups. Examples of polar functional groups include hydroxyl groups, carboxyl groups, substituted amino groups or unsubstituted amino groups substituted with alkyl groups having 1 to 6 carbon atoms, and heterocyclic groups such as epoxy groups.

[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, per 100 parts by mass of the total structural units of the (meth)acrylic acid ester polymer.

[0047] Examples of monomers containing aromatic groups include (meth)acrylic acid esters having one (meth)acryloyl group and one or more aromatic rings (e.g., a benzene ring, a naphthalene ring, etc.) within the molecule, and containing a phenyl group, a phenoxyethyl group, or a benzyl group. By including these structural units, the whitening phenomenon of polarizing plates that occurs in high temperature and high humidity environments can be suppressed.

[0048] The content of structural units derived from monomers having aromatic groups in the (meth)acrylic acid 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, per 100 parts by mass of the total structural units of the (meth)acrylic acid polymer.

[0049] Examples of acrylamide monomers include N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, and N-(2-methylpropoxymethyl)acrylamide. By including these structural units, the bleed-out of additives such as antistatic agents, which will be discussed later, can be suppressed.

[0050] Structural units derived from monomers other than structural unit (I) may include structural units derived from styrene monomers, structural units derived from vinyl monomers, structural units derived from monomers having multiple (meth)acryloyl groups in the molecule, and so on.

[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. If the weight-average molecular weight is 500,000 or more, the durability of the first adhesive layer in high-temperature, high-humidity environments can be improved. If the weight-average molecular weight is 2,500,000 or less, the operability when applying the coating liquid containing the adhesive composition is improved. 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, "weight-average molecular weight" and "number-average molecular weight" are polystyrene equivalent values ​​measured by gel permeation chromatography (GPC).

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

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

[0054] (Meth)acrylic resins may contain two or more (meth)acrylic acid ester polymers. Examples of such (meth)acrylic acid ester polymers include relatively low molecular weight (meth)acrylic acid ester polymers whose main component is structural unit (I) derived from the (meth)acrylic acid ester, and whose weight-average molecular weight is in the range of 50,000 to 300,000.

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

[0056] [Crosslinking agent] The adhesive composition preferably contains a crosslinking agent. Examples of crosslinking agents include conventional crosslinking agents (e.g., isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, etc.), and isocyanate compounds are particularly preferred from the viewpoint of the pot life of the adhesive composition, the crosslinking rate, and the durability of the polarizing plate.

[0057] Isocyanate compounds are compounds having at least two isocyanate groups (-NCO) in their molecule. Specifically, examples include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, and triphenylmethane triisocyanate. Adduct compounds obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolprone, as well as dimers and trimers of these isocyanate compounds, are also examples. Two or more isocyanate compounds may be combined.

[0058] The proportion of the crosslinking agent 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, per 100 parts by mass of (meth)acrylic resin.

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

[0060] Examples of silane compounds 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] Furthermore, the silane compound may contain oligomers derived from the above-mentioned silane compound.

[0062] The silane compound content in the adhesive composition may be 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, per 100 parts by mass of (meth)acrylic resin. When the silane compound content is 0.01 parts by mass or more, the adhesion between the adhesive layer and the adherend tends to improve, and when the content is 10 parts by mass or less, the bleed-out of the silane compound from the adhesive layer tends to be suppressed.

[0063] [Antistatic agent] The adhesive composition may further contain an antistatic agent. Known antistatic agents are examples, and ionic antistatic agents are preferred. Examples of cationic components constituting the ionic antistatic agent include organic cations and inorganic cations. Examples of organic cations include pyridinium cations, imidazolium cations, ammonium cations, sulfonium cations, and phosphonium cations. Examples of inorganic cations include alkali metal cations such as lithium cations, potassium cations, sodium cations, and cesium cations, and alkaline earth metal cations such as magnesium cations and calcium cations. The anionic component constituting the ionic antistatic agent may be either an inorganic anion or an organic anion, but an anionic component containing a fluorine atom is preferred in terms of superior antistatic performance. An anionic component containing a fluorine atom is the hexafluorophosphate anion (PF6). - ), bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N - ], bis(fluorosulfonyl)imide anion [(FSO2)2N - Examples include anions.

[0064] Ionic antistatic agents that are solid at room temperature are preferred because they offer excellent long-term stability of the antistatic performance of the adhesive composition.

[0065] The amount of 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, per 100 parts by mass of (meth)acrylic resin.

[0066] The adhesive composition may contain one or more additives such as UV absorbers, solvents, crosslinking catalysts, tackifiers, and plasticizers. Furthermore, it is also useful to incorporate UV-curable compounds into the adhesive composition, form an adhesive layer, and then cure it by irradiating it with UV light to create a harder adhesive layer.

[0067] The adhesive layer can be formed, for example, by dissolving or dispersing the adhesive composition in a solvent to obtain a solvent-containing adhesive composition, and then applying this to the surface of the layer on which the adhesive layer is to be provided, and drying it.

[0068] The thickness of the 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 can be formed from an adhesive composition.

[0070] Examples of adhesive compositions include water-based adhesive compositions and curable adhesive compositions that harden by heating or irradiation with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays. Examples of water-based adhesive compositions include those in which polyvinyl alcohol-based resin or urethane resin is dissolved in water as the main component, and those in which polyvinyl alcohol-based resin or urethane resin is dispersed in water as the main component. Water-based adhesive compositions may further contain curable components or crosslinking agents such as polyhydric aldehydes, melamine compounds, zirconia compounds, zinc compounds, glyoxal compounds, and water-soluble epoxy resins. Examples of water-based adhesive compositions include the adhesive composition described in Japanese Patent Publication No. 2010-191389, the adhesive composition described in Japanese Patent Publication No. 2011-107686, the composition described in Japanese Patent Publication No. 2020-172088, and the composition described in Japanese Patent Publication No. 2005-208456.

[0071] The curable adhesive composition preferably contains a curable (polymerizable) compound as its main component and is an active energy ray curable adhesive composition that hardens upon irradiation with active energy rays. Examples of active energy ray curable adhesive compositions include cationic polymerization adhesive compositions containing a cationic polymerizable compound as the curable compound, radical polymerization adhesive compositions containing a radical polymerizable compound as the curable compound, and hybrid adhesive compositions containing both a cationic polymerizable compound and a radical polymerizable compound as the curable compound.

[0072] Cationic polymerizable compounds are compounds or oligomers that undergo a cationic polymerization reaction and harden upon irradiation with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays, or upon heating. Specific examples include epoxy compounds, oxetane compounds, and vinyl compounds.

[0073] Examples of epoxy compounds include alicyclic epoxy compounds such as 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (compounds having one or more epoxy groups bonded to an alicyclic ring in the molecule); aromatic epoxy compounds such as bisphenol A diglycidyl ether (compounds having both an aromatic ring and an epoxy group in the molecule); and aliphatic epoxy compounds such as 2-ethylhexylglycidyl ether and 1,4-butanediol diglycidyl ether (compounds having at least one oxirane ring bonded to an aliphatic carbon atom in the molecule).

[0074] Examples of oxetane compounds include compounds having one or more oxetane rings in the molecule, such as 3-ethyl-3-{[(3-ethyloxetane-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 photocatalytic cationic polymerization initiator. Examples of cationic polymerization initiators 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 included.

[0076] Examples of cationic polymerizable adhesive compositions include the cationic polymerizable compositions described in Japanese Patent Publication No. 2016-126345, International Publication No. 2019 / 10315, and Japanese Patent Publication No. 2021-113969.

[0077] Radical polymerizable compounds are compounds or oligomers that undergo radical polymerization reactions and harden upon irradiation with active energy rays such as ultraviolet light, visible light, electron beams, and X-rays, or upon heating. Specifically, examples include compounds having ethylenically unsaturated bonds. Examples of compounds having ethylenically unsaturated bonds 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 (meth)acrylic compounds include (meth)acrylate monomers having at least one (meth)acryloyloxy group in the molecule, (meth)acrylamide monomers, and (meth)acryl group-containing compounds such as (meth)acrylic oligomers obtained by reacting two or more functional group-containing compounds and 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 radical polymerization initiators 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; xanthones, 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 included.

[0080] Examples of radical polymerization adhesive compositions include the radical polymerizable compositions described in Japanese Patent Publication No. 2016-126345, Japanese Patent Publication No. 2016-153474, and International Publication No. 2017 / 183335.

[0081] The active energy ray curing adhesive composition may optionally contain additives such as ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, defoamers, antistatic agents, leveling agents, and solvents.

[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 phase difference layer. The leveling agent content 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 solids.

[0083] The bonding of the first phase difference layer and the second phase difference layer with an adhesive layer can be performed by applying an adhesive composition to at least one of the bonding surfaces selected from the bonding surface of the first phase difference layer and the bonding surface of the second phase difference layer, overlapping the two layers with the adhesive composition coating layer in between, pressing them together from above and below using a bonding roll or the like, and then drying the adhesive layer, curing it by irradiating it with active energy rays, or curing it by heating.

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

[0085] Various coating methods can be used to form the coating layer of the adhesive composition, including die coaters, comma coaters, gravure coaters, wire bar coaters, and doctor blade coaters.

[0086] The light irradiation intensity when irradiating with active energy rays is determined for each composition of the active energy ray-curable adhesive composition and is not particularly limited, but is 10 mW / cm². 2 More than 1,000mW / cm 2 The following is preferable. The irradiation intensity is preferably in the wavelength range effective for activating the photocationic polymerization initiator or the photoradical polymerization initiator. The light is irradiated once or multiple times at such an irradiation intensity, and the accumulated light dose is 10 mJ / cm². 2 Preferably, it should be 100 mJ / cm² or higher. 2 More than 1000mJ / cm 2 The following is more preferable.

[0087] The light source used for polymerization curing of 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 water-based adhesive composition may be, for example, 5 μm or less, preferably 1 μm or less, more preferably 0.5 μm or less, 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, more preferably 3 μm or less, may be 0.1 μm or more, preferably 0.5 μm or more, and more preferably 1 μm or more.

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

[0091] (first retardation layer) The first phase difference layer is a cured layer of an oriented polymerizable liquid crystal compound, which exhibits a phase difference.

[0092] The first phase difference layer is not limited to any layer that generates a phase difference in any direction, and may be a phase difference layer that generates a phase difference in the plane, such as a positive A plate and a negative A plate, or a layer that generates a phase difference in the thickness direction, such as a positive C plate and a negative C plate. Furthermore, the positive A and negative A plates may each be λ / 4 plates or λ / 2 plates. In addition, the first phase difference layer may be tilt-oriented or form a cholesteric-oriented state.

[0093] The first phase difference layer may be a single-layer liquid crystal phase difference layer, or it may be a laminate of multiple liquid crystal phase difference layers.

[0094] The first phase difference layer may be positive wavelength dispersive or negative wavelength dispersive.

[0095] The first phase difference layer is, for example, a film cured in which polymerizable liquid crystal compounds are oriented. In order to create a phase difference within the viewing surface, the film must be a cured film in which polymerizable groups of polymerizable liquid crystal compounds are polymerized in a state where they are oriented horizontally to the substrate surface.

[0096] If the polymerizable liquid crystal compound is a rod-shaped liquid crystal, a positive A plate is sufficient; if the polymerizable liquid crystal compound is a disc-shaped liquid crystal, a negative A plate is sufficient.

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

[0098] To achieve a high level of anti-reflective properties, it is preferable that the first phase difference layer has a λ / 4 plate function (i.e., a π / 2 phase difference function) across the entire visible light spectrum. Furthermore, to achieve a high level of anti-reflective properties, it is preferable that the laminate of the first phase difference layer and the second phase difference layer has a λ / 4 plate function (i.e., a π / 2 phase difference function) across the entire visible light spectrum. Specifically, an inverse wavelength-dispersive λ / 4 layer is preferred, or it is preferable to combine two or more phase difference films with different orientations. For example, a combination of a phase difference film having a λ / 2 plate function (i.e., a π phase difference function) as the first phase difference layer and a phase difference film having a λ / 4 plate function (i.e., a π / 2 phase difference function) as the second phase difference layer may be used.

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

[0100] Below, we will describe, as examples of a first phase difference layer and a laminate of the first and second phase difference layers, a laminate of inverse wavelength dispersive λ / 4 plates, a positive wavelength dispersive λ / 4 plate, and a positive C plate.

[0101] <Reverse wavelength dispersion λ / 4 plate> For an inverse wavelength-dispersive λ / 4 plate, the λ / 4 function across the entire visible light spectrum is preferably satisfied with the optical properties shown in the following equations (R1) and (R2), where Re(λ) is the in-plane phase difference value for light of wavelength λnm, and is preferably satisfied with the optical properties shown in the following equations (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 phase difference value (in nm) for light with a wavelength of 450 nm, Re(550) represents the in-plane phase difference value (in nm) for light with a wavelength of 550 nm, and Re(650) represents the in-plane phase difference value (in nm) for light with a wavelength of 650 nm.) When the "Re(450) / Re(550)" ratio of the liquid crystal phase difference film exceeds 1.0, the light loss on the short-wavelength side increases in the circular polarizer (elliptical polarizer) equipped with the liquid crystal phase difference film. Preferably, it is 0.7 to 1.0, more preferably 0.80 to 0.95, even more preferably 0.80 to 0.92, and particularly preferably 0.82 to 0.88.

[0103] The "Re(450) / Re(550)" value can be arbitrarily adjusted by adjusting the mixing ratio of polymerizable liquid crystal compounds, as well as the stacking angles and phase difference values ​​of multiple optical anisotropic layers.

[0104] The in-plane phase difference value of the phase difference film can be adjusted by the thickness of the phase difference film. Since the in-plane phase difference value is determined by the following formula (4), to obtain a desired in-plane phase difference value (Re(λ)), the Δn(λ) and film thickness d should be adjusted. The thickness of the phase difference film is preferably 0.5 μm to 5 μm, and more preferably 1 μm to 3 μm. The thickness of the phase difference film can be measured by an interferometer, laser microscope, or stylus-type film thickness gauge. Note that Δn(λ) depends on the molecular structure of the polymerizable liquid crystal compound, which will be described later.

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

[0106] <Positive C-plate> Positive C plates are not particularly limited as long as they have anisotropy in the thickness direction, but if they are not tilt-oriented or cholesteric-oriented, they have optical properties represented by equation (PC3). nx≒ny <nz (PC3)

[0107] The in-plane phase difference 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 phase difference value Rth(550) in the thickness direction at a wavelength of 550 nm may be in the range of -170 nm to -10 nm, preferably in the range of -150 nm to -20 nm, and more preferably in the range of -100 nm to -40 nm. If the phase difference value in the thickness direction is within this range, the anti-reflection characteristics from oblique directions can be further improved.

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

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

[0110] The first phase difference layer is preferably formed by coating a composition containing a polymerizable liquid crystal compound (hereinafter also referred to as the "composition for forming the first phase difference layer") onto a transparent substrate to create an optically anisotropic layer (hereinafter also referred to as the "phase difference film") made of an oriented polymer of the polymerizable liquid crystal compound, as this allows for thinning and arbitrary design of wavelength dispersion characteristics.

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

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

[0113] [First retardation layer forming composition] (Polymerizable liquid crystal compound) The polymerizable liquid crystal compound included in the polymerizable liquid crystal composition refers to a liquid crystal compound having polymerizable groups, particularly photopolymerizable groups. Conventionally known polymerizable liquid crystal compounds can be used as the polymerizable liquid crystal compound for forming the inverse wavelength dispersive λ / 4 plate. A photopolymerizable group refers to a reaction-active species generated from a photopolymerization initiator, and is a group that can participate in the polymerization reaction by means of active radicals or acids, for example. Examples of photopolymerizable groups include vinyl groups, vinyloxy groups, 1-chlorovinyl groups, isopropenyl groups, 4-vinylphenyl groups, acryloyloxy groups, methacryloyloxy groups, oxyranil groups, and oxetanil groups. Among these, acryloyloxy groups, methacryloyloxy groups, vinyloxy groups, oxyranil groups, and oxetanil groups are preferred, and acryloyloxy groups are more preferred. The liquid crystal properties may be thermotropic or lyotropic, but thermotropic liquid crystals are preferred because they allow for precise control of film thickness. Furthermore, the phase-ordered structure in the thermotropic liquid crystal may be either a nematic or a smectic liquid crystal. It may also be a rod-shaped or disc-shaped liquid crystal. Polymerizable liquid crystal compounds can be used alone or in combination of two or more.

[0114] As polymerizable liquid crystal compounds, liquid crystals having a T-shaped or H-shaped mesogenic structure with further birefringence in the direction perpendicular to the long axis of the molecule are preferred from the viewpoint of exhibiting inverse wavelength dispersion, and T-shaped liquid crystals are more preferred from the viewpoint of obtaining stronger dispersion. Specifically, the structure of a T-shaped liquid crystal is, for example, the following formula (I):

[0115] [ka] Examples of compounds represented by [the formula shown] are given.

[0116] In formula (I), Ar represents a divalent aromatic group which may have substituents. Preferably, the divalent aromatic group contains at least one of a nitrogen atom, an oxygen atom, or a sulfur atom. If the divalent group Ar contains two or more aromatic groups, the two or more aromatic groups may be linked to each other by single bonds, divalent bonding groups such as -CO-O-, and -O-.

[0117] G1 and G2 each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atoms in the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with halogen atoms, C1-C4 alkyl groups, C1-C4 fluoroalkyl groups, C1-C4 alkoxy groups, cyano groups, or nitro groups, and the carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with oxygen atoms, sulfur atoms, or nitrogen atoms.

[0118] L 1 , L 2 B 1 and B 2 Each of these is independently a single bond or a divalent linking group.

[0119] k and l each represent integers from 0 to 3 independently, satisfying the relationship 1 ≤ k + l. Here, if 2 ≤ k + l, then B 1 and B 2 , G 1 and G 2 These elements may be identical to each other, or they may be different.

[0120] E 1 and E 2Each of the following independently represents an alkanediyl group having 1 to 17 carbon atoms, where the hydrogen atoms in the alkanediyl group may be substituted with halogen atoms, and the -CH2- groups in the alkanediyl group may be substituted with -O-, -S-, or -COO-, and if there are multiple -O-, -S-, or -COO- groups, they are not adjacent to each other. P1 and P2 independently represent a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.

[0121] G 1 and G 2 Each of these is independently preferably a 1,4-phenylenediyl group which may be substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, or a 1,4-cyclohexanediyl group which may be substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, more preferably a methyl-substituted 1,4-phenylenediyl group, an unsubstituted 1,4-phenylenediyl group, or an unsubstituted 1,4-trans-cyclohexanediyl group, and particularly preferably an unsubstituted 1,4-phenylenediyl group or an unsubstituted 1,4-trans-cyclohexandiyl group.

[0122] Multiple Gs exist 1 and G 2 Preferably, at least one of them is a divalent alicyclic hydrocarbon group, and L 1 or L 2 G that joins 1 and G 2 It is more preferable that at least one of these is a divalent alicyclic hydrocarbon group.

[0123] L 1 and L 2 Each of these is independently, preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a1 Ure a2 -, -R a3 COOR a4 -, -R a5 OCOR a6 -, R a7 OC=OORa8 -, -N=N-, -CR c =CR d -, or C≡C-. Here, R a1 ~R a8 Each of these independently represents a single bond or an alkylene group with 1 to 4 carbon atoms, R c and R d L represents an alkyl group with 1 to 4 carbon atoms or a hydrogen atom. 1 and L 2 Each is independently, more preferably a single bond, -OR a2-1 -, -CH2-, -CH2CH2-, -COOR a4-1 -, or OCOR a6-1 - is the case here R a2-1 , R a4-1 , R a6-1 Each of these independently represents either a single bond, -CH2-, or -CH2CH2-. 1 and L 2 Each of these is independently, and more preferably, a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, or OCO-.

[0124] B 1 and B 2 Each of these is independently, preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a9 Ure a10 -, -R a11 COOR a12 -, -R a13 OCOR a14 -, or R a15 OC=OOR a16 - is the case here R a9 ~R a16 Each of these independently represents a single bond or an alkylene group with 1 to 4 carbon atoms. 1 and B 2 Each is independently, more preferably a single bond, -OR a10-1 -, -CH2-, -CH2CH2-, -COOR a12-1 -, or OCOR a14-1 - is the case here R a10-1 , R a12-1 , R a14-1Each independently represents a single bond, -CH2-, or -CH2CH2-. B 1 and B 2 Each independently is more preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, -OCO-, or OCOCH2CH2-.

[0125] From the viewpoint of expressing inverse wavelength dispersion, 2 ≤ k + l ≤ 6 is preferable, k + l = 4 is preferable, and k = 2 and l = 2 are more preferable. When k = 2 and l = 2, it is preferable because it has a symmetric structure.

[0126] E 1 and E 2 Each independently is preferably an alkanediyl group having 1 to 17 carbon atoms, and more preferably an alkanediyl group having 4 to 12 carbon atoms.

[0127] P 1 or P 2 Examples of the polymerizable group represented by include an epoxy group, a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferable, and an acryloyloxy group is more preferable.

[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, an anthracene ring, etc., and a benzene ring and a naphthalene ring are 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, etc. Among them, it is preferable to have a thiazole ring, a benzothiazole ring, or a benzofuran ring, and it is more preferable to have a benzothiazole group. Further, when Ar contains a nitrogen atom, the nitrogen atom preferably 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, still more preferably 14 or more, and particularly preferably 16 or more. Also, it is preferably 30 or less, more preferably 26 or less, and still more preferably 24 or less.

[0130] Examples of the aromatic group represented by Ar preferably include the following groups.

[0131]

Chemical formula

[0132] In formulas (Ar-1) to (Ar-23), the * mark represents the connecting part, and Z 0 , Z 1 and Z 2Each of these independently represents a hydrogen atom, a halogen atom, a C1-C12 alkyl group, a cyano group, a nitro group, a C1-C12 alkylsulfinyl group, a C1-C12 alkylsulfonyl group, a carboxyl group, a C1-C12 fluoroalkyl group, a C1-C6 alkoxy group, a C1-C12 alkylthio group, a C1-C12 N-alkylamino group, a C2-C12 N,N-dialkylamino group, a C1-C12 N-alkylsulfamoyl group, or a C2-C12 N,N-dialkylsulfamoyl group.

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

[0134] J 1 , and J 2 Each of these independently represents either a carbon atom or a nitrogen atom.

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

[0136] W 1 and W 2 Each of these independently represents a hydrogen atom, a cyano group, a methyl group, or a halogen atom, and m represents an integer from 0 to 6.

[0137] Y 1 , and Y 2Examples of aromatic hydrocarbon groups in this context include C6-C20 aromatic hydrocarbon groups such as phenyl, naphthyl, anthuryl, phenanthuryl, and biphenyl groups, with phenyl and naphthyl groups being preferred and phenyl groups being more preferred. Examples of aromatic heterocyclic groups include C4-C20 aromatic heterocyclic groups containing at least one heteroatom such as a nitrogen atom, oxygen atom, or sulfur atom, such as furyl, pyrrolyl, thienyl, pyridinyl, thiazolyl, and benzothiazolyl groups, with furyl, thienyl, pyridinyl, thiazolyl, and benzothiazolyl groups being preferred.

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

[0139] Z 0 , Z 1 and Z 2 Each of these is preferably independently a hydrogen atom, a halogen atom, a C1-C12 alkyl group, a cyano group, a nitro group, or a C1-C12 alkoxy group, Z 0 A hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and a cyano group are more preferably Z 1 and Z 2 Hydrogen atoms, fluorine atoms, chlorine atoms, methyl groups, and cyano groups are more preferred.

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

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

[0142] In equations (Ar-16) to (Ar-23), Y 1 This is the nitrogen atom and Z to which it is bonded. 0 It may also form an aromatic heterocyclic group. Examples of aromatic heterocyclic groups that Ar may have include those mentioned above, such as a pyrrole ring, imidazole ring, pyrroline ring, pyridine ring, pyrazine ring, pyrimidine ring, indole ring, quinoline ring, isoquinoline ring, purine ring, pyrrolidine ring, etc. This aromatic heterocyclic group may have substituents. Also, Y 1 This is the nitrogen atom and Z to which it is bonded. 0 In addition, the aforementioned substituted polycyclic aromatic hydrocarbon groups or polycyclic aromatic heterocyclic groups may also be used. Examples include benzofuran rings, benzothiazole rings, and benzoxazole rings.

[0143] Among polymerizable liquid crystal compounds, compounds with a maximum absorption wavelength of 300-400 nm are preferred. When a polymerizable liquid crystal composition contains a photopolymerization initiator, the polymerization reaction and gelation of the polymerizable liquid crystal compound may proceed during long-term storage. However, if the maximum absorption wavelength of the polymerizable liquid crystal compound is 300-400 nm, even if exposed to ultraviolet light during storage, the generation of reactive species from the photopolymerization initiator and the progression of the polymerization reaction and gelation of the polymerizable liquid crystal compound by these reactive species can be effectively suppressed. Therefore, this is advantageous in terms of the long-term stability of the polymerizable liquid crystal composition and can improve the orientation and uniformity of the film thickness of the resulting liquid crystal cured film. The maximum absorption wavelength of the polymerizable liquid crystal compound can be measured using an ultraviolet-visible spectrophotometer in a solvent. The solvent is a solvent that can dissolve the polymerizable liquid crystal compound, and examples include chloroform.

[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, per 100 parts by mass of the solid content of the polymerizable liquid crystal composition. A content of the polymerizable liquid crystal compound within the above range is advantageous from the viewpoint of the orientation of the resulting liquid crystal cured film. In this specification, the solid content of the polymerizable liquid crystal composition refers to all components of the polymerizable liquid crystal composition excluding volatile components such as organic solvents.

[0145] [Laminate containing positive wavelength dispersive λ / 2 plate and positive wavelength dispersive λ / 4 plate] One method for achieving anti-reflective performance is to laminate a first phase difference layer and a second phase difference layer. For example, a laminate combining a positive wavelength dispersive λ / 2 plate and a positive wavelength dispersive λ / 4 plate is known. One example of such a laminate is obtained by combining a layer having optical properties represented by equations (Q1), (Q3), and (Q4) with a layer having optical properties represented by equations (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] Well-known methods for combining the above configurations can be found in Japanese Patent Publication No. 2015-163935 and WO2013 / 137464. From the viewpoint of viewing angle compensation, it is preferable to use a λ / 2 layer containing a polymer of a disc-shaped polymerizable liquid crystal compound and a λ / 4 layer containing a polymer of a rod-shaped polymerizable liquid crystal compound.

[0148] The laminate of the first phase difference layer and the second phase difference layer may be a laminate in which at least one liquid crystal phase difference layer is tilt-oriented or cholesteric-oriented, in addition to the above-mentioned configuration of a combination of a positive wavelength dispersive λ / 2 layer and a positive wavelength dispersive λ / 4 layer. Examples of well-known configurations include those described in International Publication No. 2021 / 060378, International Publication No. 2021 / 132616, and International Publication No. 2021 / 132624.

[0149] In the case of a laminate other than a laminate combining a positive wavelength dispersive λ / 2 plate and a positive wavelength dispersive λ / 4 plate, it is preferable that the laminate of the first phase difference layer, the first bonding layer joining the first phase difference layer and the second phase difference layer satisfies the following relationships (1) and (2). 100 ≤ Re(550) ≤ 180 (1) Re(450) / Re(550)≦1.00 (2) [In equations (1) and (2), Re(450) represents the in-plane phase difference value (nm) for light with a wavelength of 450 nm. Re(550) represents the in-plane phase difference value (nm) for light with a wavelength of 550 nm.

[0150] The in-plane phase difference value of the above laminate (phase difference body) is the value measured using a measuring instrument such as the KOBRA-WR manufactured by Oji Instruments Co., Ltd., in the state of polarizing plate / laminating layer / first phase difference layer / first laminating layer / second phase difference layer, with a polarizing plate laminated on the above laminate via a bonding layer. The polarizing plate and bonding layer can be any polarizing plate and bonding layer described later and the aforementioned bonding layer.

[0151] The first and second phase difference layers may be the same liquid crystal phase difference layer, or they may be different combinations of different types.

[0152] For example, one of the first phase difference layer and the second phase difference layer may be an inverse wavelength dispersive λ / 4 plate, and the other of the first phase difference layer and the second phase difference layer may be a positive C plate.

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

[0154] [ka]

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

[0156] Examples of rod-shaped polymerizable liquid crystal compounds include those represented by formulas (I), (II), (III), (IV), (V), or (VI). P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III) P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV) P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V) P11-B11-E11-B12-A11-B13-A12-F11 (VI) A11 represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atoms in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group may be substituted with halogen atoms, C1-C6 alkyl groups, C1-C6 alkoxy groups, cyano groups, or nitro groups, and the hydrogen atoms in the C1-C6 alkyl groups and the C1-C6 alkoxy groups may be substituted with fluorine atoms.

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

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

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

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

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

[0162] Specifically, examples include linear alkanediyl groups having 1 to 12 carbon atoms, such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, and dodecane-1,12-diyl group; and -CH2-CH2-O-CH2-CH2-, -CH2-CH2-O-CH2-CH2-O-CH2-CH2-, and CH2-CH2-O-CH2-CH2-O-CH2-CH2-.

[0163] For B11, -O-, -S-, -CO-O-, and -O-CO- are preferred, with -CO-O- being the most preferred among them.

[0164] For B12 and B13, -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)-, and -OC(=O)-O- are preferred, respectively, with -O- or OC(=O)-O- being more preferred.

[0165] As for the polymerizable group represented by P11, radical polymerizable groups or cationic polymerizable groups are preferred in terms of high polymerization reactivity, particularly photopolymerization reactivity, and are easy to handle, as well as the liquid crystal compound itself is easy to manufacture. Therefore, the polymerizable group is preferably a group represented by the following formulas (P-11) to (P-15).

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

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

[0168] [ka]

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

[0170] It is even more preferable that the group represented by P11-B11- is an acryloyloxy group or a methacryloyloxy group.

[0171] In the formula, A12 to A14 are each independently synonymous with A11, B14 to B16 are each independently synonymous with B12, B17 is synonymous with B11, and E12 is synonymous with E11. F11 represents a hydrogen atom, a C1-C13 alkyl group, a C1-C13 alkoxy group, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxyl group, a methylol group, a formyl group, a sulfo group (-SO3H), a carboxyl group, a C1-C10 alkoxycarbonyl group, or a halogen atom, and the -CH2- constituting the alkyl group and alkoxy group may be replaced with -O-.

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

[0173] The composition for forming the first phase difference layer may further contain reactive additives such as solvents, leveling agents, polymerization initiators, photosensitizers, polymerization inhibitors, crosslinking agents, and adhesion promoters, in addition to the polymerizable liquid crystal compound described above. From the viewpoint of processability, it is preferable to include a solvent and / or a leveling agent, and from the viewpoint of F and Si addition, it is preferable to add a silicone-based leveling agent and / or a fluorine-based leveling agent.

[0174] (solvent) The composition for forming the first phase difference layer may contain a solvent. Generally, polymerizable liquid crystal compounds have high viscosity, so dissolving them in a solvent makes application easier, and as a result, the formation of the first phase difference layer is often facilitated. The solvent is preferably one that can completely dissolve the polymerizable liquid crystal compound, and is also preferably an inert solvent in the polymerization reaction of the polymerizable liquid crystal compound.

[0175] Examples of solvents include alcoholic solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene, and nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; and amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone. These solvents may be used individually or in combination of two or more.

[0176] The solvent content is preferably 50 to 98% by mass relative to the total amount of the composition for forming the first phase difference layer. In other words, the solid content in the composition for forming the first phase difference layer is preferably 2 to 50% by mass, and more preferably 5 to 30% by mass. When the solid content is 50% by mass or less, the viscosity of the composition for forming the first phase difference layer decreases, which tends to result in a more uniform thickness of the first phase difference layer, thus reducing the likelihood of unevenness in the first phase difference layer. Furthermore, the solid content can be determined considering the thickness of the optically anisotropic layer to be manufactured.

[0177] (Leveling agent) The composition for forming the first phase difference layer may contain a leveling agent. A leveling agent is an additive that adjusts the fluidity of the composition and makes the film obtained by coating the composition flatter. Examples include organically modified silicone leveling agents, polyacrylate leveling agents, and perfluoroalkyl leveling agents. Among these, polyacrylate leveling agents and perfluoroalkyl leveling agents are preferred for horizontal orientation, while organically modified silicone leveling agents and perfluoroalkyl leveling agents are preferred for vertical orientation. Examples include silicone leveling agents, acrylic leveling agents, and fluorine leveling agents. Among these, silicone leveling agents and fluorine leveling agents are preferred because they have excellent function in reducing the tension of the film surface obtained by coating the composition.

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

[0179] Groups bonded to silicon atoms (silicon atoms forming siloxane bonds) in polyorganosiloxanes include hydrocarbon groups. Silicone-based leveling agents may have two hydrocarbon groups bonded to a silicon atom. There are no limitations on the groups bonded to the silicon atom, but alkyl groups and aryl groups having 1 to 10 carbon atoms are preferred, more preferably methyl groups and phenyl groups, and even more preferably methyl groups. The group bonded to the silicon atom may be one type or two or more types. Furthermore, the number of repeating siloxane units (degree of polymerization) is not particularly limited, but is preferably 2 to 10,000, more preferably 3 to 5,000, and even more preferably 5 to 1,000.

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

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

[0182] Fluorine-based leveling agents are not particularly limited, but examples include leveling agents having a fluoroaliphatic hydrocarbon skeleton. The fluorinated aliphatic hydrocarbon skeleton is not particularly limited. For example, fluorinated alkanes having 1 to 10 carbon atoms such as fluoromethane, fluoroethane, fluoropropane, fluoroisopropane, fluorobutane, fluoroisobutane, fluorot-butane, fluoropentane, fluorohexane, etc. can be mentioned. In the fluorinated aliphatic hydrocarbon skeleton, at least some of the hydrogen atoms may be substituted with fluorine atoms, or it may be a perfluorinated aliphatic hydrocarbon skeleton in which all the hydrogen atoms are substituted with fluorine atoms.

[0183] Further, the fluorinated aliphatic hydrocarbon skeleton may form a polyfluoroalkylene ether skeleton which is a repeating unit via an ether bond. The fluorinated aliphatic hydrocarbon group as a repeating unit is not particularly limited. For example, fluorinated C1-4 alkylene groups such as fluoromethylene, fluoroethylene, fluoropropylene, fluoroisopropylene, etc. can be mentioned. The above fluorinated aliphatic hydrocarbon group may be only one kind, or two or more kinds. The repeating number (degree of polymerization) of the fluoroalkylene ether unit is not particularly limited, but is preferably 10 to 10000, more preferably 30 to 5000, and still more preferably 50 to 1000.

[0184] As examples of the fluorine-based leveling agent, commercially available products can be used, 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, 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, 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, E5844 (Daikin Fine Chemical Research Institute Co., 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 part by mass to 2 parts by mass, more preferably 0.01 part by mass to 1.5 parts by mass, and still more preferably 0.1 part by mass to 1.5 parts by mass with respect to 100 parts by mass of the above polymerizable liquid crystal compound.

[0186] When the composition for forming the first phase difference layer contains various leveling agents, the amount of leveling agents is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, per 100 parts by mass of the polymerizable liquid crystal compound. When the content of the leveling agent is within the above range, it is easy to orient the polymerizable liquid crystal compound horizontally, and the resulting optical anisotropic layer tends to be smoother. If the content of the leveling agent relative to the polymerizable liquid crystal compound exceeds the above range, the resulting optical anisotropic layer tends to be uneven. The composition for forming the optical anisotropic layer may contain two or more types of leveling agents.

[0187] (Polymerization initiator) The composition for forming the first phase difference layer may contain a polymerization initiator. The polymerization initiator is a compound capable of initiating a polymerization reaction, such as a polymerizable liquid crystal compound. As a polymerization initiator, a photopolymerization initiator that generates active radicals upon the action of light is preferred, from the viewpoint of not being dependent on the phase state of the thermotropic liquid crystal.

[0188] Any known photopolymerization initiator can be used as the photopolymerization initiator, as long as it is a compound capable of initiating the polymerization reaction of a polymerizable liquid crystal compound. Specifically, photopolymerization initiators that can generate active radicals or acids upon the action of light are recommended, and among these, photopolymerization initiators that generate radicals upon the action of light are preferred. Photopolymerization initiators can be used alone or in combination of two or more types.

[0189] As photopolymerization initiators, known photopolymerization initiators can be used. For example, as photopolymerization initiators that generate active radicals, self-cleaving benzoin compounds, acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, oxime ester compounds, acylphosphine oxide compounds, azo compounds, etc. can be used. Hydrogen abstraction types such as benzophenone compounds, alkylphenone compounds, benzoin ether compounds, benzyl ketal compounds, dibenzosverone compounds, anthraquinone compounds, xanthone compounds, thioxanthone compounds, halogenoacetophenone compounds, dialkoxyacetophenone compounds, halogenobisimidazole compounds, halogenotriazine compounds, triazine compounds, etc. can be used. As photopolymerization initiators that generate acid, iodonium salts and sulfonium salts, etc. can be used. Self-cleaving photopolymerization initiators are preferred from the viewpoint of excellent reaction efficiency at low temperatures, and acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, and oxime ester compounds are particularly preferred.

[0190] The content of the polymerization initiator in the composition for forming the first phase difference layer can be appropriately adjusted according to the type and amount of 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, per 100 parts by mass of the polymerizable liquid crystal compound. When the content of the polymerization initiator is within the above range, polymerization can be carried out without disturbing the orientation of the polymerizable liquid crystal compound.

[0191] (Sensitizer) The composition for forming the first phase difference layer may contain a sensitizer. Photosensitizers are preferred as sensitizers. Examples of such sensitizers include xanthone compounds such as xanthones and thioxanthones (e.g., 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene compounds such as anthracene and alkoxy group-containing anthracene (e.g., dibutoxyanthracene, etc.); phenothiazines and rubrene, etc.

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

[0193] (Antioxidant) From the viewpoint of ensuring stable polymerization reaction, the composition for forming the first phase difference layer may contain an antioxidant. The antioxidant can be used to control the degree of polymerization of the polymerizable liquid crystal compound.

[0194] The antioxidant may be, for example, a primary antioxidant selected from phenolic antioxidants, amine antioxidants, quinone antioxidants, and nitroso antioxidants, or a secondary antioxidant selected from phosphorus antioxidants and sulfur antioxidants.

[0195] When the composition for forming the first phase difference layer contains an antioxidant, the amount of 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, per 100 parts by mass of the polymerizable liquid crystal compound. The antioxidant can be used alone or in combination of two or more types. When the amount of antioxidant is within the above range, polymerization can be carried out without disrupting the orientation of the polymerizable liquid crystal compound.

[0196] (Reactive additives) The composition for forming the first phase difference layer may contain a reactive additive. Preferred reactive additives have carbon-carbon unsaturated bonds, active hydrogen reactive groups, or thiol groups within their molecules. Here, "active hydrogen reactive group" refers to a group that reacts to groups containing active hydrogen, such as carboxyl groups (-COOH), hydroxyl groups (-OH), and amino groups (-NH2). Typical examples include glycidyl groups, oxazoline groups, carbodiimide groups, aziridine groups, imide groups, isocyanate groups, thioisocyanate groups, and maleic anhydride groups. The number of reactive groups in each reactive additive may be 1 to 20, preferably 1 to 10.

[0197] (polymerizable monomer) The composition for forming the first phase difference layer may contain polymerizable monomers. The inclusion of polymerizable monomers in the composition for forming the first phase difference layer improves the uniformity and strength of the coating film. Examples of polymerizable monomers include radical polymerizable or cationic polymerizable compounds. Among these, polyfunctional radical polymerizable monomers are preferred.

[0198] The polymerizable monomer is preferably one that can copolymerize with the polymerizable liquid crystal compound described above. The polymerizable monomer content is preferably 1 to 50% by mass, and more preferably 2 to 30% by mass, relative to the total mass of the polymerizable liquid crystal compound.

[0199] (Surfactants) The composition for forming the first phase difference layer may contain a surfactant. The inclusion of a surfactant in the composition for forming the first phase difference layer improves the uniformity and strength of the coating film. Examples of surfactants include conventionally known compounds. Among these, the surfactant is particularly preferably a fluorine-based compound.

[0200] The Martens hardness of the surface on the first protective layer side of the first phase difference layer is set to 100 N / mm², from the viewpoint of suppressing deformation defects in the optical laminate while providing sufficient crack resistance even under thermal shock conditions. 2That concludes the explanation. The Martens hardness of the surface on the first protective layer side of the first phase difference layer is set to 130 N / mm² from the viewpoint of more easily suppressing deformation defects in the optical laminate. 2 The above is preferable, 150 N / mm 2 The above is more preferable, 170 N / mm 2 The above is even more preferable, 180 N / mm 2 The above is even more preferable, 200 N / mm 2 The above is particularly preferred, 220 N / mm 2 The above is even more preferable, 230 N / mm 2 The above is highly preferable. The Martens hardness of the surface on the first protective layer side of the first phase difference layer is 300 N / mm². 2 The following, or 250 N / mm 2 The following may also be used. Martens hardness can be measured by the method described in the examples below.

[0201] The Martens hardness of the surface on the first protective layer side of the first phase difference layer can be adjusted by changing the formation method and components of the first phase difference layer. For example, the Martens hardness of the first phase difference layer can be improved by including polymerizable monomers and surfactants in the composition for forming the first phase difference layer. Furthermore, the degree of polymerization can be increased and the Martens hardness of the first phase difference layer can be improved by adjusting the cumulative amount of ultraviolet light and the temperature during irradiation when curing the first phase difference layer.

[0202] The Martens hardness of the surface on the first protective layer side of the first phase difference layer is preferably greater than the Martens hardness of the surface on the opposite side of the first protective layer of the first phase difference layer, from the viewpoint of suppressing scratches at the peel interface on the first phase difference film side when peeling the substrate from the first phase difference film. The difference between the Martens hardness of the surface on the first protective layer side of the first phase difference layer and the Martens hardness of the surface on the opposite side of the first protective layer of the first phase difference layer is, for example, 10 N / mm². 2 That's fine too.

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

[0204] (Coating of the composition for forming a retardation layer) As a method for applying the composition for forming a retardation layer onto a substrate or the first alignment layer, examples include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a CAP coating method, a slit coating method, a micro gravure method, a die coating method, an inkjet method, etc. Further, methods for applying the composition for forming a retardation layer also include methods of applying using a coater such as a dip coater, a bar coater, a spin coater, etc. Among them, when continuously applying in a Roll to Roll format, coating methods by a micro gravure method, an inkjet method, a slit coating method, and a die coating method are preferable, and when applying to a sheet-like substrate such as glass, a spin coating method with high uniformity is preferable. When applying in a Roll to Roll format, a composition for forming a first alignment layer or the like can be applied onto the substrate to form a first alignment layer, and the composition for forming a retardation layer can be continuously applied onto the obtained first alignment layer.

[0205] (Substrate) Examples of substrates include glass substrates and film substrates, with film substrates being preferred, and long roll-shaped films being more preferred because they can be manufactured continuously. Examples of resins constituting the film substrate include polyolefins such as polyethylene, polypropylene, and norbornene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate esters; polyacrylic acid esters; cellulose esters such as triacetylcellulose, diacetylcellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; polyphenylene sulfide and polyphenylene oxide. Among these, from the viewpoint of transparency when used in optical film applications, it is more preferable that the substrate be a film substrate selected from triacetylcellulose, cyclic olefin resins, polymethacrylate 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 Nippon Zeon Co., Ltd.), and "Apel" (registered trademark) (manufactured by Mitsui Chemicals, Inc.). Such cyclic olefin resins can be used as substrates by forming films using known methods such as solvent casting and melt extrusion. Commercially available cyclic olefin resin substrates can also be used. Commercially available cyclic olefin resin substrates include "SCSina" (registered trademark), "SCA40" (registered trademark) (both manufactured by Sekisui Chemical Co., Ltd.), "ZEONOR Film" (registered trademark) (manufactured by Optes Co., Ltd.), and "Arton Film" (registered trademark) (manufactured by JSR Corporation).

[0208] The substrate thickness is preferably thin enough to allow for practical handling, but if it is too thin, the strength decreases and processability tends to be poor. The substrate thickness 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 substrate thickness is 30 μm or more, when the phase difference layer forming composition is applied to the substrate, 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 thermal wrinkles in the substrate due to drying and irradiation with active energy rays tends to be suppressed. When the substrate thickness is 50 μm or less, the flexibility resistance of the optical laminate tends to be further improved. Furthermore, a further thinning effect can be obtained by peeling off the substrate and transferring a polarizing film or a liquid crystal cured film.

[0209] The substrate thickness should preferably be thin enough to allow for practical handling, but if it is too thin, the strength will decrease and processability will be poor. The substrate thickness may be 5 μm to 300 μm, preferably 10 μm to 200 μm, and more preferably 10 to 50 μm. Furthermore, a thinning effect can be obtained by peeling off the substrate and transferring a polarizing film or a phase difference film.

[0210] (Drying of the composition for forming the phase difference layer) Drying methods to remove solvents contained in the phase difference layer forming composition include, for example, natural drying, forced-air drying, heat drying, reduced-pressure drying, and combinations thereof. 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, more preferably 30 seconds to 5 minutes.

[0211] (Polymerization of polymerizable liquid crystal compounds) Photopolymerization is preferred as a method for polymerizing polymerizable liquid crystal compounds. Photopolymerization is performed by irradiating an optical laminate, on which a phase difference layer forming composition containing a polymerizable liquid crystal compound is coated on a substrate or a first orientation layer, with active energy rays. The active energy rays to be irradiated are appropriately selected according to the type of polymerizable liquid crystal compound contained in the dried film (particularly the type of photopolymerizable functional group possessed by the polymerizable liquid crystal compound), the type of photopolymerization initiator if one is included, and their amounts. Specifically, this includes one or more types of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, alpha rays, beta rays, and gamma rays. Among these, ultraviolet light is preferred because it is easy to control the progress of the polymerization reaction and because photopolymerization apparatus widely used in this 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 active energy 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 in the wavelength range of 380-440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps.

[0213] The UV irradiation intensity is, for example, 10 mW / cm². 2 ~3000mW / cm 2 The ultraviolet irradiation intensity is preferably in the wavelength range effective for activating the cationic polymerization initiator or radical polymerization initiator. The 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 irradiation is performed once or multiple times at such ultraviolet irradiation intensity, the integrated light amount is 10 mJ / cm². 2 ~3000 mJ / cm 2 It may be, preferably 50 mJ / cm² 2 ~2000 mJ / cm 2 More preferably, 100 mJ / cm² 2 ~1000 mJ / cm2 When the integrated light intensity is within this range, the polymerizable liquid crystal compound tends to cure sufficiently, resulting in good transferability, and it is also easier to suppress discoloration of the optical film containing the optical anisotropy layer.

[0214] Ultraviolet light can be irradiated in one or multiple passes. Depending on the polymerization initiator used, the integrated light intensity at a wavelength of 365 nm is 700 mJ / cm². 2 Preferably, it should be 1100 mJ / cm² or higher. 2 It is more preferable to set it to 1300 mJ / cm² or higher. 2 It is even more preferable to use the above values. Using the above integrated light intensity is advantageous in increasing the polymerization rate of the polymerizable liquid crystal compound constituting the phase difference film and improving its heat resistance. The integrated light intensity at a wavelength of 365 nm is 2000 mJ / cm². 2 Preferably, it should be 1800 mJ / cm². 2 The following is more preferable. Using the above integrated light intensity can suppress discoloration of the phase difference film.

[0215] When curing the coating layer of the phase difference layer forming composition 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, there is a concern that wrinkles will form in the substrate layer and phase difference unevenness will occur, so 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. Note that the above-mentioned upper and lower limits can be combined arbitrarily.

[0216] <First orientation layer> The first phase difference film may or may not include a first orientation layer. The first orientation layer has an orientation-regulating force that causes the polymerizable liquid crystal compound to be liquid crystal oriented in a desired direction.

[0217] The first orientation layer facilitates the liquid crystal orientation of the polymerizable liquid crystal compound. The state of liquid crystal orientation, such as horizontal orientation, vertical orientation, hybrid orientation, and tilted orientation, changes depending on the properties of the first orientation layer and the polymerizable liquid crystal compound, and any combination can be arbitrarily selected. For example, if the first orientation layer is formed of a material that exhibits horizontal orientation as an orientation restricting force, the polymerizable liquid crystal compound can form horizontal or hybrid orientation. Also, if the first orientation layer is formed of a material that exhibits vertical orientation, the polymerizable liquid crystal compound can form vertical or tilted orientation. Expressions such as horizontal and vertical refer to the direction of the optical axis of the oriented polymerizable liquid crystal compound with respect to the plane of the first phase difference layer. For example, vertical orientation means that the optical axis of the oriented polymerizable liquid crystal compound is perpendicular to the plane of the first phase difference layer. Here, perpendicular means 90° ± 20° with respect to the plane of the first phase difference layer.

[0218] The orientation-regulating force can be arbitrarily adjusted by surface conditions and rubbing conditions if the first orientation layer is formed from an orientation-oriented polymer, and by polarization irradiation conditions, etc., if it is formed from a photo-oriented polymer. Furthermore, liquid crystal orientation can also be controlled by selecting physical properties such as surface tension and liquid crystalline properties of the polymerizable liquid crystal compound.

[0219] The first orientation layer formed between the first phase difference layers is preferably insoluble in the solvent used to form the first phase difference layer on the first orientation layer, and also has heat resistance for solvent removal and heat treatment for liquid crystal orientation. Examples of the first orientation layer include a first orientation layer made of an oriented polymer, a photo-alignment film, a groove-alignment film, and a stretched film stretched in the orientation direction. When applied to a long roll-shaped film, a photo-alignment film is preferred because the orientation direction can be easily controlled.

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

[0221] Examples of oriented polymers used in rubbing orientation films include polyamides and gelatins having amide bonds in their molecules, polyimides having imide bonds in their molecules and their hydrolysates such as polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylic acid esters. Among these, polyvinyl alcohol is preferred.

[0222] One method of rubbing involves wrapping a rubbing cloth around a rotating rubbing roll and bringing the film of the oriented polymer, formed on the surface of the substrate by applying an oriented polymer composition to the substrate and annealing it, into contact with the roll.

[0223] Photoalignment films consist of polymers, oligomers, or monomers having photoreactive groups. An orientation-regulating force can be obtained by irradiating the photoalignment film with polarized light. Photoalignment films are preferable because the direction of the orientation-regulating force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light.

[0224] A photoreactive group is a group that generates liquid crystal alignment ability upon irradiation with light. Specifically, it is a group that generates a photoreaction that is the origin of liquid crystal alignment ability, such as molecular orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodegradation reaction, upon irradiation with light. Among photoreactive groups, those that cause dimerization reactions or photocrosslinking reactions are preferred in that they have excellent orientation properties. As photoreactive groups that can generate such reactions, those having unsaturated bonds, especially double bonds, are preferred, and more preferably groups having at least one selected from the group consisting of carbon-carbon double bonds (C=C bonds), carbon-nitrogen double bonds (C=N bonds), nitrogen-nitrogen double bonds (N=N bonds), and carbon-oxygen double bonds (C=O bonds).

[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 groups and cinnamoyl groups are preferred from the viewpoint of ease of controlling reactivity and the expression of orientation-regulating power during photo-orientation. Examples of photoreactive groups having a C=N bond include groups having structures such as aromatic Schiff bases and aromatic hydrazones. Examples of photoreactive groups having an N=N bond include azobenzene groups, azonaphthalene groups, aromatic heterocyclic azo groups, bisazo groups, and formazan groups, as well as those with azoxybenzene as their basic structure. Examples of photoreactive groups having a C=O bond include benzophenone groups, coumarin groups, anthraquinone groups, and maleimide groups. These groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and halogenated alkyl groups.

[0226] Polarized light can be irradiated directly from the film surface, or it can be irradiated from the substrate side and transmitted through. Furthermore, it is particularly preferable that the polarized light be substantially parallel. The wavelength of the irradiated polarized light should be in a wavelength range in which the photoreactive groups of the polymer or monomer having photoreactive groups can absorb light energy. Specifically, UV (ultraviolet light) in the wavelength range of 250 to 400 nm is particularly preferred. Light sources used for this polarization irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and ultraviolet lasers such as KrF and ArF, with high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps being more preferred. These lamps are preferred because they have a high emission intensity of ultraviolet light at a wavelength of 313 nm. Polarized light can be irradiated by passing the light from the light source through a suitable polarizer. Such polarizers can include polarizing filters, polarizing prisms such as Grant-Thomson and Grant-Taylor, and wire grid type polarizers.

[0227] <Second phase difference film and third phase difference film> The second and third phase difference films may appropriately refer to the configuration of the first phase difference film described above.

[0228] <Second lamination layer and sixth lamination layer> The second lamination layer has the function of joining the first phase difference film and the second phase difference film. The sixth lamination layer has the function of joining the second phase difference film and the third phase difference film. The composition of the second and sixth lamination layers can be described by referring to the above description of the first lamination layer. The second and sixth lamination layers may be composed of the same material as the first lamination layer, or they may be composed of different materials, independently of each other.

[0229] An 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 phase difference film side. The polarizer layer may be bonded via a third bonding layer provided on the surface of the first protective layer.

[0230] <Polarizer layer> As the polarizer layer, for example, a film can be used that is uniaxially stretched while impregnated with iodine or an organic dichroic dye in a polymer such as a polyvinyl alcohol-based resin film (hereinafter also referred to as "PVA-based film"). The polarizer is manufactured, for example, by a process of uniaxially stretching a polyvinyl alcohol-based resin film (hereinafter also referred to as "PVA-based film"), a process of adsorbing a dichroic dye by dyeing the PVA-based film with a dichroic dye, a process of crosslinking the PVA-based film on which the dichroic dye has been adsorbed with an aqueous boric acid solution, and a process of washing with water after the crosslinking treatment with the aqueous boric acid solution (hereinafter also referred to as "boric acid treatment"). The polarizer layer may contain a crosslinking agent. A polarizer layer made of a polymerizable liquid crystal compound containing a dichroic dye is preferred because its hue can be arbitrarily controlled, it can be made significantly thinner, and it is non-shrinkable because there is no stretching relaxation due to heat, and can be suitably used, for example, in flexible display applications.

[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 keeping the thickness of the polarizer layer below the above upper limit, the flexibility 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] Uniaxial stretching of PVA-based films can be performed before, simultaneously with, or after dyeing with dichroic dyes. When uniaxial stretching is performed after dyeing, it may be performed before, during, or in multiple stages of boric acid treatment. Uniaxial stretching can be performed using methods such as stretching uniaxially in the film transport direction between rolls with different peripheral speeds, stretching uniaxially in the film transport direction using a heated roll, or stretching in the width direction using a tenter. Uniaxial stretching may also be performed by dry stretching in the atmosphere, or by wet stretching using a solvent such as water to swell the PVA-based film before stretching. 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 a drying treatment, and then stretched together with the thermoplastic resin film using the above method.

[0233] Dyeing of PVA-based films with dichroic dyes can be carried out, for example, by immersing the PVA-based film in an aqueous solution containing a dichroic dye. Specifically, iodine or dichroic organic dyes can be used as dichroic dyes. It is preferable to immerse the PVA-based film in water to swell it before the dyeing treatment.

[0234] When iodine is used as a dichroic dye, for example, a method of dyeing is employed in which a PVA-based film is immersed in an aqueous solution containing iodine and potassium iodide. The iodine content in the aqueous solution may be 0.01 to 1 part by mass per 100 parts by mass of water, and the potassium iodide content 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 boric acid content in the boric acid-containing aqueous solution may be 2 to 15 parts by mass per 100 parts by mass of water, preferably 5 to 12 parts by mass. When iodine is used as the dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide. The potassium iodide content in the boric acid-containing aqueous solution may be 0.1 to 15 parts by mass per 100 parts by mass of water, preferably 5 to 12 parts by mass. The immersion time in the boric acid-containing aqueous solution may be 60 to 1200 seconds, preferably 150 to 600 seconds, 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, more preferably 60 to 80°C.

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

[0237] After washing with water, the polarizer is dried to obtain the polarizer. The drying process can be carried out using a hot air dryer or a far-infrared heater. The drying temperature 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. Through the drying process, the moisture content in the polarizer is reduced to a practical level. The moisture content may be 5 to 20% by mass of the total mass of the polarizer, preferably 8 to 15% by mass. If the moisture content is 5% by mass or more, the polarizer has sufficient flexibility, so damage or breakage after drying can be suppressed. If the moisture content is 20% by mass or less, the polarizer has sufficient thermal stability, defects are reduced, and axial misalignment can be suppressed.

[0238] As described above, a polarizer can be manufactured in which a dichroic dye is adsorbed and oriented on a PVA-based film. The polarizer may have a protective film laminated to one or both sides via the adhesive described above.

[0239] The polarizer layer can be formed by applying a polarizing film-forming composition and aligning 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, and an adhesion enhancer.

[0240] A polarizer layer in which a dichroic dye and a polymerizable liquid crystal compound are horizontally oriented with respect to the substrate surface preferably has a ratio (dichroic ratio) of 7 or more between the absorbance A1(λ) in the orientation direction and the absorbance A2(λ) in the direction perpendicular to the orientation plane for light of wavelength λnm, more preferably 20 or more, and even more preferably 40 or more. The higher this value, the better the absorption selectivity of the polarizer. Depending on the type of dichroic dye, the ratio is about 5 to 10 for a liquid crystal cured film cured in the nematic liquid crystal phase state.

[0241] By mixing two or more dichroic dyes with different absorption wavelengths, polarizer layers of various hues can be formed, resulting in polarizer layers that absorb across the entire visible light spectrum. Such polarizer layers with specific absorption characteristics can be applied to a wide range of uses.

[0242] The polymerizable liquid crystal compound may be one of the polymerizable liquid crystal compounds described above. The liquid crystal properties may be thermotropic liquid crystal or lyotropic liquid crystal, but when mixed with a dichroic dye, thermotropic liquid crystal is preferred. The polymerizable liquid crystal compound may be a monomer or a polymer formed by polymerizing dimers or more.

[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 being able to exhibit high dichroism, the liquid crystal state exhibited by the polymerizable liquid crystal compound is preferably a smectic phase, and from the viewpoint of improving performance, it is more preferably a higher-order smectic phase. Among these, higher-order smectic liquid crystal compounds that form smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase, or smectic L phase are more preferred, and higher-order smectic liquid crystal compounds that form smectic B phase, smectic F phase, or smectic I phase are even more preferred. 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 manufactured. Furthermore, polarizer layers with such high polarization performance yield Bragg peaks originating from higher-order structures such as the hexatic phase and crystalline phase in X-ray diffraction measurements. Bragg peaks are peaks derived from the periodic structure of molecular orientation, and films with a periodic interval of 3 to 6 Å can be obtained. The polarizer layer contains polymers of polymerizable liquid crystals oriented in the smectic phase, which further enhances the polarization characteristics.

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

[0245] Dichroic dyes are dyes that have different absorbances along the long axis and short axis of the molecule. Dichroic dyes preferably have the property of absorbing visible light, and more preferably have an absorption maximum wavelength (λMAX) in the range of 380 to 680 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes, with azo dyes being preferred. Examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbenazo dyes, with bisazo dyes and trisazo dyes being preferred. Dichroic dyes may be used individually or in combination, but to obtain absorption across the entire visible light range, it is preferable to combine two or more dichroic dyes, and more preferably to combine three or more dichroic dyes.

[0246] Examples of azo dyes include the compound represented by formula (α) (hereinafter sometimes 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 Each of these independently represents an optionally substituted 1,4-phenylene group, an optionally substituted naphthalene-1,4-diyl group, an optionally substituted phenyl benzoate group, an optionally substituted 4,4'-stilbenylene group, or an optionally substituted divalent heterocyclic group. 1 and T 2 A is an electron-withdrawing or electron-emitting group located substantially 180° to the azo bond plane. p represents an integer from 0 to 4. If p is 2 or greater, each A 2 These may be identical or different from each other. Within the range showing absorption in the visible spectrum, the -N=N- bond may be replaced by -C=C-, -COO-, -NHCO-, or -N=CH- bonds.

[0247] The content of the dichroic dye (total amount if 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, per 100 parts by mass of the polymerizable liquid crystal compound, from the viewpoint of obtaining good light absorption characteristics. If the content of the dichroic dye is less than this range, light absorption will be insufficient and sufficient polarization performance cannot be obtained, and if it is more than this range, the orientation of liquid crystal molecules may be inhibited.

[0248] The polarization performance of a polarizer can be measured using a spectrophotometer. For example, the transmittance (T) in the transmission axis direction (perpendicular to orientation) in the wavelength range of 380 nm to 780 nm, which is visible light. 1 ) and transmittance (T) in the absorption axis direction (orientation direction) 2 ) can be measured using the double-beam method with a spectrophotometer equipped with a prism polarizer. The polarization performance in the visible light range can be calculated by using the following equations (Equation 1) and (Equation 2) to calculate the single transmittance and polarization degree at each wavelength, and then performing luminous efficiency correction using the 2-degree field of view (C light source) of JIS Z 8701 to calculate the luminous efficiency corrected single transmittance (Ty) and luminous efficiency corrected polarization degree (Py). Similarly, L can be calculated from the measured transmittance using the color matching function of the C light source. * a * b * Chromaticity a in the (CIE) color system * and b * By calculating this, the hue of a polarizer alone (single hue), the hue of polarizers arranged in parallel (parallel hue), and the hue of polarizers arranged orthogonally (orthogonal hue) can be obtained. * and b * The closer the value is to 0, the more neutral the hue is considered to be. Single unit transmittance (%) = (T 1 +T 2 ) / 2 …(Formula 1) Polarization degree (%) = (T 1 -T 2 ) / (T 1 +T 2 )×100…(Formula 2)

[0249] The luminous efficiency correction polarization degree Py of the polarizer may be 80% or higher, preferably 90% or higher, more preferably 95% or higher, even more preferably 98% or higher, and particularly preferably 99% or higher. If it is 99.9% or higher, it can be suitably used in liquid crystal displays. Increasing the luminous efficiency correction polarization degree Py of the polarizer is advantageous in enhancing the anti-reflective function of the optical laminate. If the luminous efficiency correction polarization degree Py is less than 80%, it may not be able to perform its anti-reflective function when used as an anti-reflective film.

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

[0251] <Third lamination layer and fourth lamination layer> The third bonding layer has the function of bonding the polarizer layer and the first protective layer. The fourth bonding layer has the function of bonding the polarizer layer and the second protective layer, which will be described later. The third and fourth bonding layers can be described by referring to the above-mentioned descriptions of the first or third bonding layer. The fourth bonding layer may be made of the same material as the first or third bonding layer, or it 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 the polarizer via a bonding layer, or a double-protected polarizing plate in which protective layers are laminated on both sides of the polarizer via bonding layers. For example, it may be a polarizing plate in which the layers are laminated in the order of polarizer / third bonding layer / first protective layer, or a polarizing plate in which the layers are laminated in the order of second protective layer / fourth bonding layer / polarizer / third bonding layer / first protective layer.

[0253] An 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 a second protective layer, the polarizer layer and the second protective layer may be directly laminated to each other. Here, "directly laminated" includes embodiments in which the second protective layer is laminated to the polarizer layer by its self-adhesion, and embodiments in which it is laminated via an adhesive layer or a tackifying layer.

[0254] <Second protective layer> The second protective layer has the function of protecting the surface of the polarizer layer. The composition of the second protective layer can be described by referring 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 it may be made of a different material. To improve adhesion with the polarizer layer, the second protective layer may be subjected to surface treatment (e.g., corona treatment, etc.), and a thin layer such as a primer layer (also called an easy-adhesion layer) may be formed on it.

[0255] The second protective layer may be subjected to surface treatments such as hard coating, anti-reflective coating, anti-sticking coating, and anti-glare coating, as needed. Furthermore, the second protective layer may be subjected to treatments to improve visibility when viewed through polarized sunglasses (for example, by providing circular or elliptical polarization functionality, or by providing ultra-high phase difference), as needed. By applying such treatments, excellent visibility can be achieved even when viewing the display screen through polarized lenses such as polarized sunglasses. Therefore, an optical laminate equipped with such a treated second protective layer can be suitably applied to image display devices that may be used outdoors.

[0256] <Fifth lamination layer> The fifth lamination layer is positioned on the surface of the optical laminate on the second phase difference film side and has the function of bonding to the image display device. The fifth lamination layer can be described by referring to the description of the first lamination layer above, and the fifth lamination layer is preferably an adhesive layer. The fifth lamination layer may be made of the same material as the other lamination layers, or it may be made of different materials.

[0257] [Optical laminate] The optical laminate described above can be used as a circular polarizer. A circular polarizer is an optical component in which a polarizer and a phase difference film are laminated, and can be used in devices that display images in a planar state, such as organic EL image display devices, to prevent light reflection at the electrodes that make up the device.

[0258] The thickness of the optical laminate may be 70 μm or more, and preferably 80 μm or more, from the viewpoint of obtaining good flexibility. It may also be 150 μm or less, and preferably 120 μm or less.

[0259] [Method for manufacturing optical laminates] An optical laminate according to one embodiment can be manufactured by a method comprising the steps of: preparing a first phase difference film including a first phase difference layer and a first alignment layer; and obtaining a first optical laminate by providing a first protective layer on the surface of the first phase difference film on the first phase difference layer side via a first bonding layer. In this manufacturing method, the Martens hardness of the surface of the first protective layer side of the first phase difference layer is 100 N / mm². 2 As described above, the ratio of the Martens hardness of the surface of the first phase difference layer on the first protective layer side to the Martens hardness of the first protective layer is 1.5 or higher. With this manufacturing method, it is possible to produce optical laminates that have sufficient crack resistance even under thermal shock conditions while suppressing deformation defects.

[0260] When an optical laminate has a second phase difference film, there are two methods for bonding the first phase difference film and the first protective layer: sequential bonding and pre-bonding.

[0261] In the case of sequential lamination, first the first protective layer and the first phase difference layer of the first phase difference film are bonded via a laminating layer. Next, the interface between the first phase difference layer and the first orientation layer of the first phase difference film is delaminated. Then, the first phase difference layer and the second phase difference layer of the second phase difference film are bonded via a laminating layer. Furthermore, a laminating layer and a separator film are formed sequentially from the exposed surface (the surface of the second phase difference layer or the second orientation layer) exposed by the process of separating the substrate layer (or second orientation layer) of the second phase difference film. The separator film can cover and protect the surface of the laminating layer opposite to the second phase difference layer and can be provided so as to be peelable from the laminating layer. This makes it possible to obtain an optical laminate in which the first protective layer, laminating layer, first phase difference layer, laminating layer, second phase difference layer, and laminating layer are laminated in this order. Alternatively, instead of delaminating at the interface between the first phase difference layer and the first orientation layer of the first phase difference film, the first orientation layer may be delaminated from the substrate, and the first orientation layer may be bonded to the second phase difference layer of the second phase difference film via a laminating layer. In this case, an optical laminate can be obtained in which the first protective layer, the bonding layer, the first alignment layer, the first phase difference layer, the bonding layer, and the second phase difference layer are stacked in this order.

[0262] In the case of pre-bonding, first, the first phase difference layer of the first phase difference film and the second phase difference layer of the second phase difference film are bonded via a bonding layer. Next, the interface between the first phase difference layer and the first orientation layer of the first phase difference film is delaminated. Then, the first protective layer and the first phase difference layer are bonded via a bonding layer. Furthermore, a bonding layer and a separator film are formed sequentially from the exposed surface (the surface of the second phase difference layer or the second orientation layer) that is exposed by the process of separating the substrate layer (or second orientation layer) of the second phase difference film. The separator film can cover and protect the surface of the bonding layer opposite to the second phase difference layer and can be provided so as to be peelable from the bonding layer. This makes it possible to obtain an optical laminate in which the first protective layer, bonding layer, first phase difference layer, bonding layer, second phase difference layer, and bonding layer are laminated in this order. Alternatively, instead of delaminating at the interface between the first phase difference layer and the first orientation layer of the first phase difference film, the first orientation layer may be delaminated from the substrate, and the first orientation layer may be bonded to the second phase difference layer of the second phase difference film via a bonding layer. In this case, an optical laminate can be obtained in which the first protective layer, the bonding layer, the first alignment layer, the first phase difference layer, the bonding layer, and the second phase difference layer are stacked 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 positioned on the viewing side of the image display element. The optical laminate can be bonded to the image display element using an adhesive layer.

[0264] The image display device is not particularly limited and examples include organic electroluminescent (organic EL) display devices, inorganic electroluminescent (inorganic EL) display devices, liquid crystal display devices, and electroluminescent display devices.

[0265] Image display devices can be used as mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic signs, measuring instruments or gauges, office equipment, medical equipment, computer equipment, etc. [Examples]

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

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

[0268] 1-1-2. Preparation of polymerizable liquid crystal compounds Polymerizable liquid crystal compounds (A1) and (A2), having the structures shown below, were prepared, respectively. Polymerizable liquid crystal compounds (A1) and (A2) were prepared in the same manner as described in Japanese Patent Application Publication No. 2010-244038. Polymerizable liquid crystal compound (A1): [ka] Polymerizable liquid crystal compound (A2): [ka]

[0269] 1-1-3. Preparation of the composition (1) for forming the first phase difference layer 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 Corporation), and 0.1 parts of ionic compound (B) were added. Furthermore, 650 parts of cyclopentanone were added, and this mixture was stirred at a temperature of 80°C for 1 hour to prepare composition (1) for forming the first phase difference layer. Ionic compounds (B): [ka]

[0270] 1-1-4. Preparation of the first phase difference film (1) with substrate A cyclic polyolefin resin (COP) film (ZF14, manufactured by Nippon Zeon Co., Ltd.) was subjected to corona treatment using a corona treatment device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.) as a substrate. After corona treatment, the alignment film-forming composition (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 rubbing treatment, and the first phase difference layer-forming composition (1) was applied thereon using a bar coater. After drying the obtained coated film at 120°C for 2 minutes, it was exposed to a high-pressure mercury lamp (UniCure VB-15201BY-A, manufactured by Ushio Inc.) under a nitrogen atmosphere at 80°C with an exposure dose of 1000 mJ / cm². 2 By irradiating the dried film with ultraviolet light (based on 365 nm), a first phase difference layer (1) was formed in which the optical axis of the polymerizable liquid crystal compound was oriented horizontally with respect to the substrate plane, thereby obtaining a substrate-mounted first phase difference film (1) consisting of substrate / alignment film / first phase difference layer (1). The thickness of the obtained first phase difference layer (1) was measured with a laser microscope and found to be 1.4 μm. The in-plane phase difference value at a wavelength of 550 nm was Re(550) = 270 nm. Note that the phase difference value of the COP film at a wavelength of 550 nm is approximately 0, so this does not affect the optical properties.

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

[0272] 1-3. Preparation of the first phase difference film (3) with substrate 1-3-1. Preparation of compositions for photo-alignment film formation A photo-oriented material with the following structure (weight-average molecular weight: 50,000, m:n=50:50) was manufactured according to the method described in Japanese Patent Application Publication No. 2021-196514. A photo-oriented film-forming composition was prepared by mixing 2 parts by mass of the photo-oriented material with 98 parts by mass of cyclopentanone (solvent) and stirring the resulting mixture at 80°C for 1 hour. Photoalignable materials: [ka]

[0273] 1-3-2. Preparation of polymerizable liquid crystal compounds Polymerizable liquid crystal compounds (A3) and (A4) having the structures shown below were prepared, respectively. Polymerizable liquid crystal compound (A3) was prepared in the same manner as described in Japanese Patent Application Publication No. 2019-003177. Polymerizable liquid crystal compound (A4) was prepared in the same manner as described in Japanese Patent Application Publication No. 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 a path length of 1 cm, and the measurement sample was set in a UV-Vis spectrophotometer (Shimadzu Corporation "UV-2450") to measure the absorption spectrum. When the wavelength at which the absorption maximum was obtained was read from the obtained absorption spectrum, the maximum absorption wavelength λmax in the wavelength range of 300-400 nm was found to be 356 nm.

[0275] 1-3-3. Preparation of the composition (2) for forming the first phase difference layer 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 "Irgacure OXE-03" (manufactured by BASF Japan Ltd.) as a photopolymerization initiator were added. Furthermore, N-methyl-2-pyrrolidone (NMP) was added to achieve a solid content concentration of 13% by mass. Composition (2) for forming the first phase difference layer was prepared by stirring this mixture at a temperature of 80°C for 1 hour.

[0276] 1-3-4. Preparation of the first phase difference film (3) with substrate As a substrate, a cyclic polyolefin resin (COP) film (ZF14, manufactured by Nippon Zeon Co., Ltd.) was coated with the above-mentioned photo-alignment film-forming composition using a bar coater. The resulting coated film was dried at 120°C for 2 minutes, and then cooled to room temperature to form a dried film. Subsequently, a photo-alignment film was obtained by irradiating it with polarized ultraviolet light at 100 mJ (313 nm reference) using a UV irradiation device (SPOT CURE SP-9; manufactured by Ushio Inc.). The film thickness of the photo-alignment film, measured using an ellipsometer M-220 manufactured by JASCO Corporation, was 100 nm.

[0277] The first phase difference layer forming composition (2) was applied to the obtained photo-alignment film using a bar coater to form a coated film. This coated 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 film was in contact with the hot plate. The hot plate was placed in a case and nitrogen was sealed inside for 1 minute. Ultraviolet light was irradiated onto the coated surface of the first phase difference layer forming composition (3) using a high-pressure mercury lamp (UniCure VB-15201BY-A, manufactured by Ushio Inc.) (under a nitrogen atmosphere, wavelength: 365 nm, irradiation intensity at wavelength 365 nm: 10 mW / cm²). 2 Total luminous intensity: 1000 mJ / cm² 2 By doing so, a first phase difference layer (3) was formed, and a first phase difference film (3) with a substrate was obtained, consisting of a substrate / photo-alignment film / first phase difference layer (3) (horizontally aligned liquid crystal cured film). The thickness of the first phase difference layer (3), measured using an Olympus Corporation laser microscope LEXT OLS4100, was 2.1 μm.

[0278] Corona treatment was performed on the surface of the first phase difference film (3) with the substrate attached, on the side of the first phase difference layer (3), and it was bonded to glass via a 25 μm pressure-sensitive adhesive manufactured by Lintec Corporation. The substrate was then peeled off and removed. The in-plane phase difference values ​​were measured using a KOBRA-WR manufactured by Oji Instruments Co., Ltd. The in-plane phase difference values ​​for light at wavelengths of 450 nm, 550 nm, and 650 nm were determined from Cauchy's dispersion formula obtained from the measurement results of the in-plane phase difference values ​​for light at wavelengths of 448.2 nm, 498.6 nm, 548.4 nm, 587.3 nm, 628.7 nm, and 748.6 nm. As a result, the in-plane phase difference values ​​were Re(450)=122 nm, Re(550)=140 nm, and Re(650)=144 nm, and the relationship of the in-plane phase difference 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 phase difference value for light with a wavelength of 450 nm, Re(550) represents the in-plane phase difference value for light with a wavelength of 550 nm, and Re(650) represents the in-plane phase difference value for light with a wavelength of 650 nm.)

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

[0280] 1-5. Preparation of the first phase difference film (5) with substrate 1-5-1. Preparation of the composition (3) for forming the first phase difference layer 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 the leveling agent "BYK-361N" (manufactured by BM Chemie) and 3 parts by mass of "Irgacure OXE-03" (manufactured by BASF Japan Ltd.) as a photopolymerization initiator were added. Furthermore, N-methyl-2-pyrrolidone (NMP) was added to achieve a solid content concentration of 13% by mass. By stirring this mixture at a temperature of 80°C for 1 hour, a composition (3) for forming the first phase difference layer was prepared.

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

[0282] 2. Preparation of a second phase difference film with a substrate. 2-1. Preparation of the second phase difference film (1) with substrate 2-1-1. Preparation of the composition (1) for forming the second phase difference layer 100 parts of the polymerizable liquid crystal compound Paliocolor LC242 (manufactured by BASF Japan), 0.1 parts of the leveling agent "BYK-361N" (manufactured by BYK-Chemie), and 2.5 parts of the photopolymerization initiator "Omnirad907" (manufactured by IGM Resin BV) were mixed. Furthermore, 400 parts of propylene glycol 1-monomethyl ether 2-acetate (PGME) were added, and the resulting mixture was stirred at a temperature of 80°C for 1 hour to prepare composition (1) for forming the second phase difference layer. Polymerizable liquid crystal compound LC242: [ka]

[0283] 2-1-2. Preparation of the second phase difference film (1) with substrate As a substrate, a triacetylcellulose (TAC) film (Konica Minolta, Inc., KC4UY (thickness 40 μm)) was coated with the same alignment film-forming composition (1) as the first phase difference film (1) with the substrate, 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 second phase difference layer-forming composition (1) was applied thereon using a bar coater. The obtained coated layer was dried at 100°C for 1 minute, and then cooled to room temperature to obtain a dried film. Next, using a high-pressure mercury lamp (UniCure VB-15201BY-A, Ushio Inc.), 1000 mJ / cm³ was applied under a nitrogen atmosphere. 2 By irradiating the dried film with ultraviolet light (based on 365 nm), a second phase difference layer (1) (horizontally oriented liquid crystal cured film) is formed in which the polymerizable liquid crystal compound is oriented horizontally with respect to the plane of the substrate, and a substrate-attached second phase difference film (1) consisting of the substrate / alignment film / second phase difference layer (1) is obtained.

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

[0285] 2-2. Preparation of the second phase difference film (2) with substrate 2-2-1. Preparation of the alignment film forming composition (2) Composition (2) for forming an oriented film was obtained by adding 2-butoxyethanol to SunEver SE-610 (manufactured by Nissan Chemical Industries, Ltd.), a commercially available oriented polymer, to a solid content of 1%.

[0286] 2-2-2. Preparation of the second phase difference film (2) with substrate A cycloolefin polymer (COP) (ZF14, manufactured by Zeon Corporation) was subjected to corona treatment using a corona treatment device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.) as a substrate. The surface was then coated with an alignment film-forming composition (2) using a bar coater and dried at 90°C for 1 minute. The thickness of the resulting alignment film was measured with a laser microscope and found to be 30 nm. Subsequently, a second phase difference layer-forming composition (1) was coated onto the alignment film using a bar coater and dried at 90°C for 1 minute. After that, exposure was performed using a high-pressure mercury lamp (UniCure VB-15201BY-A, manufactured by Ushio Inc.) under a nitrogen atmosphere at an exposure dose of 1000 mJ / cm². 2By irradiating the dried film with ultraviolet light (based on 365 nm), a retardation film with a substrate (2) composed of a substrate / alignment 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 Rth(550) in the thickness direction was -70 nm. Therefore, 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 was approximately 0, it did 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 first retardation layer, the composition for forming the second retardation layer (2) with a substrate 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)" was 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 / alignment 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 As a composition for forming vertically aligned films, a mixture was used which consisted of 2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, dipentaerythritol triacrylate, and bis(2-vinyloxyethyl) ether in a ratio of 1:1:4:5, with 4% LUCIRIN TPO added as a polymerization initiator.

[0290] 2-4-2. Preparation of the composition (3) for forming the second phase difference layer The composition (3) for forming the second phase difference layer was prepared by mixing a photopolymerizable nematic liquid crystal compound (Merck, RMM28B) with a solvent so that the solid content was 1 to 1.5 g. The solvent used was a mixed solvent of 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 the second phase difference film (4) with substrate A polyethylene terephthalate (PET) film with a thickness of 38 μm was prepared as the substrate. A composition for forming a vertically aligned film was applied to one side of the substrate to a thickness of 3 μm, and 200 mJ / cm² was applied. 2 A vertically aligned film was fabricated by irradiation with ultraviolet light. The second phase difference layer forming composition (3) was coated onto the vertically aligned film by die coating. The coating amount was 4-5 g (wet). The coating film was dried at a drying temperature of 75°C for 120 seconds. Subsequently, the coating film was irradiated with ultraviolet (UV) light to polymerize the polymerizable liquid crystal compound and form a second phase difference layer (4), thereby obtaining a substrate-attached second phase difference film (4) consisting of a substrate / alignment film / second phase difference layer (4).

[0292] The substrate-attached second phase difference film (4) was a positive C plate. The thickness of the second phase difference layer (3) was 1 μm. After laminating the substrate-attached second phase difference film (4) to glass via an adhesive, the substrate was peeled off and the in-plane phase difference value of the second phase difference layer (4) was measured. A "KOBRA-WPR" manufactured by Oji Instruments Co., Ltd. was used for the measurement. The in-plane phase difference value at a wavelength of 550 nm was Re(550) = 1 nm, and the phase difference value in the thickness direction at a wavelength of 550 nm was Rth(550) = -100 nm. The second phase difference layer (4) exhibited positive wavelength dispersion.

[0293] 3. Fabrication of a third phase difference film with a substrate. A third phase difference film with a substrate, identical to the second phase difference 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 tube, 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 internal temperature was raised to 55°C while replacing the air in the apparatus with nitrogen gas to eliminate oxygen. Subsequently, the entirety of a solution prepared by dissolving 0.12 parts by mass of azobisisobutyronitrile (polymerization initiator) in 10 parts by mass of ethyl acetate was added. After adding the polymerization initiator, the internal temperature was maintained at 55°C for 1 hour, and then ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts by mass / hr while maintaining the internal temperature at 54-56°C. When the concentration of the (meth)acrylic resin reached 35% by mass, the addition of ethyl acetate was stopped, and the temperature was maintained at this level for another 6 hours from the start of ethyl acetate addition. Finally, ethyl acetate was added to adjust the concentration of the (meth)acrylic resin to 20% by mass, and acrylic resin solution (1) was prepared. The obtained acrylic resin had a weight-average molecular weight (Mw) of 1.7 million and a molecular weight distribution (Mw / Mn) of 3.9. Mw and Mn were measured using "TSKgel GMH" manufactured by Tosoh Corporation as the column in the GPC instrument. 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 Composition (1) for Forming 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 photopolymerization initiator (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 a composition (1) for forming an 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 an adhesive layer was applied to the release-treated surface of a separator film made of a polyethylene terephthalate film subjected to 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 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) using H bulbs. • Total luminous intensity: 250 mJ / cm² 2

[0297] 5. Preparation of adhesive sheet (2) [Preparation of acrylic resin solution (2)] A reaction vessel equipped with a condenser, a nitrogen inlet, a thermometer, and a 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 internal temperature was raised to 55°C while replacing the air in the apparatus with nitrogen gas to eliminate oxygen. Subsequently, the entirety of a solution prepared by dissolving 0.15 parts by mass of azobisisobutyronitrile (polymerization initiator) in 10 parts by mass of ethyl acetate was added. After adding the polymerization initiator, the internal temperature was maintained at 55°C for 1 hour, and then ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts by mass / hr while maintaining the internal temperature at 54-56°C. When the concentration of the (meth)acrylic resin reached 35% by mass, the addition of ethyl acetate was stopped, and the internal temperature was maintained at 55°C for another 6 hours from the start of ethyl acetate addition. Subsequently, ethyl acetate was added to adjust the concentration of the (meth)acrylic resin to 20% by mass, and acrylic resin solution (3) was prepared. The obtained acrylic resin had a weight-average molecular weight (Mw) of 1.6 million and a molecular weight distribution (Mw / Mn) of 4.5. Mw and Mn were measured in standard polystyrene equivalents using two TSKgel GMHHR-H(S) columns from Tosoh Corporation connected in series in a GPC instrument, with tetrahydrofuran as the eluent, under the conditions of a sample concentration of 2 mg / mL, sample introduction volume of 100 μL, temperature of 40°C, and flow rate of 1 mL / min.

[0298] [Preparation of the 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" (ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate (solid content concentration 75% by mass)) and 0.2 parts by mass of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.: trade name "KBM-403") were added on an active ingredient basis, and ethyl acetate was further added to bring the solid content concentration to 13% by mass to obtain a composition (2) for forming an adhesive layer.

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

[0300] 6. Preparation of adhesive (1) [Preparation of the adhesive layer forming composition (1)] After mixing the following components and then degassing, an adhesive layer-forming composition (1) was prepared, and this adhesive layer-forming composition (1) was used as adhesive (1). (Cationic polymerizable compounds) · 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-Ethylhexylglycidyl ether (product name: EX-121, manufactured by Nagase ChemteX Corporation): 10 parts by mass (Photocationic polymerization initiator) • Product name: CPI-100 (manufactured by Sunapro Co., Ltd., 50% propylene carbonate solution): 4.5 parts by mass (actual solid content 2.25 parts by mass) (Photosensitizer) • 1,4-Diethoxynaphthalene: 2 parts by mass 7. Preparation of adhesive (2) A polyvinyl alcohol aqueous solution was prepared by dissolving 3 parts by mass of carboxyl group-modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name: KL-318) in 100 parts by mass of water. To the obtained aqueous solution, water-soluble polyamide epoxy resin (manufactured by Taoka Chemical Industry Co., Ltd., trade name: Sumire's Resin 650 (30), solid content concentration 30% by mass) was mixed in a ratio of 1.5 parts by mass per 100 parts by mass of water to obtain adhesive (2).

[0301] 8. Fabrication of polarizing plates [Fabrication of polarizers] A 30 μm thick polyvinyl alcohol-based resin film (average degree of polymerization approximately 2400, degree of saponification 99 mol% or more) was uniaxially stretched to approximately 5 times its original size by dry stretching, and while maintaining tension, was immersed in pure water at 60°C for 1 minute. Next, the polyvinyl alcohol-based resin film was immersed for 60 seconds in an aqueous solution at 28°C with a mass ratio of iodine / potassium iodide / water of 0.05 / 5 / 100. Next, the polyvinyl alcohol-based resin film was immersed in an aqueous solution at 72°C with a mass ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100. Finally, the polyvinyl alcohol-based resin film was 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 oriented on the polyvinyl alcohol-based resin film. [Preparation of the first protective layer] The following film was prepared as the first protective layer. • First protective layer A: Triacetylcellulose (TAC) film (KC2UA, manufactured by Konica Minolta, Inc., thickness 25 μm, phase difference value Rth = 18 nm in the thickness direction). • First protective layer B: Triacetylcellulose (TAC) film (manufactured by Konica Minolta, Inc., 20 μm thick, in-plane phase difference value at 590 nm wavelength: 1.2 nm, thickness direction phase difference value at 590 nm wavelength: 1.3 nm). • First protective layer C: Cyclic polyolefin resin (COP) film (ZF14, manufactured by Zeon Corporation, 23 μm thick) • First protective layer D: Acrylic resin film (OXIS®, manufactured by Okura Industries Co., Ltd., 40 μm thick, in-plane phase difference value of 1 nm at a wavelength of 590 nm, phase difference value in the thickness direction of -1 nm).

[0302] [Preparation of the second protective layer] A surface-treated protective layer (a cycloolefin polymer (COP) film (ZF-14, manufactured by Nippon Zeon Co., Ltd., 23 μm thick) coated with a 3 μm thick surface treatment agent manufactured by Nippon Paper Industries Co., Ltd., was used as the second protective layer) was used.

[0303] [Fabrication of polarizing plates] The adhesive (2) prepared above was applied to one side of the polarizer obtained above, and the first protective layer A was bonded to it. The adhesive (2) prepared above was applied to the other side of the polarizer, and the side opposite to the surface treatment layer of the second protective layer was bonded to it. By drying this at a temperature of 80°C for 5 minutes, a polarizing plate A having protective layers on both sides of the polarizer was obtained. Furthermore, by changing the first protective layer A to the first protective layers B to D, polarizing plates B to D were obtained by the same procedure.

[0304] [Measurement of Martens hardness on the surface of the first protective layer in the first phase difference layer] After peeling the substrate from each of the first phase difference films with substrates obtained above, a sample for measurement was obtained by placing it on a glass plate with the side that will become the first protective layer facing upwards in each example. Under an atmosphere of 23°C and 55% relative humidity, a load of 1 mN / 10 seconds was applied to the surface of the first phase difference layer side of the sample using an ultramicrohardness tester (FISCHERSCOPE HM2000: manufactured by Fischer Instruments Co., Ltd.), and the Martens hardness measured with a creep time (time to maintain the 1 mN load) of 5 seconds was defined as the Martens hardness of the surface of the first protective layer side in the first phase difference layer.

[0305] [Measurement of Martens hardness of the first protective layer] Each first protective layer was bonded to the adhesive layer (2) exposed by peeling off one separator film from the adhesive sheet (2). Subsequently, the other separator film attached to the adhesive layer (2) was peeled off, and the surface of the exposed adhesive layer (2) was bonded to a glass plate to obtain a measurement sample in which glass / adhesive layer (2) / first protective layer were laminated in this order. Under an atmosphere of 23°C and 55% relative humidity, a load of 20 mN / 10 seconds was applied to the surface of the first protective layer side of the measurement sample using an ultramicrohardness tester (FISCHERSCOPE HM2000: manufactured by Fischer Instruments Co., Ltd.), and the Martens hardness measured with a creep time (time to maintain a load of 1 mN) of 5 seconds was defined as the Martens hardness of the first protective layer.

[0306] (Example 1) Corona treatment (800W, 10m / min, bar width 700mm, 1 pass) was applied to the first protective layer side of the polarizing plate A (MD direction length 380mm x TD direction length 180mm) prepared above. Next, the adhesive (1) prepared above was applied to the first protective layer side of the polarizing plate using a coating machine (bar coater manufactured by Daiichi Rika Co., Ltd.), and the first protective layer and the first phase difference layer (1) side of the substrate-attached first phase difference film (1) (MD direction length 380mm x TD direction length 180mm) were bonded using a bonding device ("LPA3301" manufactured by Fujipla Co., Ltd.). From the first phase difference film (1) side, an ultraviolet irradiation device with a belt conveyor (using a "H bulb" lamp manufactured by Fusion UV Systems) was used to irradiate the UVA region at an intensity of 390mW / cm². 2 The cumulative light intensity is 420 mJ / cm². 2 Therefore, in the UVB region, the radiation level is 400 mW / cm². 2 The cumulative light intensity is 400 mJ / cm². 2 The adhesive (1) was cured by irradiating it with ultraviolet light to obtain a laminate (A1) having a polarizing plate A and a first phase difference layer (1). The thickness of the layer in which the adhesive (1) had cured (hereinafter also referred to as the "first bonding layer") was measured and found to be 1.5 μm.

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

[0308] The substrate of the second phase difference film (1) with the substrate attached was peeled off from the obtained laminate (B1), and the exposed surface (the side facing the second phase difference layer) and the adhesive layer (1) surface exposed by peeling off one of the separator films from the adhesive sheet (1) (380 mm x 180 mm) prepared above were laminated together using an automatic laminating machine HALTEC, and then the other separator film was peeled off. In addition to peeling off the substrate of the second phase difference film, the alignment film was also peeled off. The other separator film was peeled off to expose the adhesive layer (1) surface, and the third phase difference layer surface of the third phase difference film with substrate (MD direction length 380 mm × TD direction length 180 mm) prepared above was laminated in sheet form using an automatic laminating machine HALTEC to obtain a laminate (C1) consisting of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / alignment film / substrate.

[0309] The substrate of the third phase difference film with the substrate attached was peeled off from the obtained laminate (C1), and the exposed surface (the surface on the third phase difference layer side) and the adhesive layer (2) exposed by peeling off one separator from the adhesive sheet (2) (300 mm × 200 mm × 380 mm × 180 mm) prepared above were laminated together in a single sheet using an automatic laminating machine HALTEC to obtain an optical laminate (1) with a separator film, consisting of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / adhesive layer (2) / separator film. The substrate of the third phase difference film was peeled off, as was the alignment film.

[0310] The separator film was peeled off the optical laminate (1), and the exposed adhesive layer (2) surface was bonded to glass. The in-plane phase difference values ​​were measured using a KOBRA-WR manufactured by Oji Instruments Co., Ltd. The in-plane phase difference values ​​for light at wavelengths of 450 nm, 550 nm, and 650 nm were determined from Cauchy's dispersion formula obtained from the measurement results of the in-plane phase difference values ​​for light at wavelengths of 448.2 nm, 498.6 nm, 548.4 nm, 587.3 nm, 628.7 nm, and 748.6 nm. As a result, the in-plane phase difference values ​​were Re(450)=115 nm, Re(550)=140 nm, and Re(650)=149 nm, and the relationship of the in-plane phase difference values ​​at each wavelength was as follows. Note that the in-plane phase difference values ​​at each wavelength for the third phase difference are approximately 0, and therefore do 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 phase difference value for light with a wavelength of 450 nm, Re(550) represents the in-plane phase difference value for light with a wavelength of 550 nm, and Re(650) represents the in-plane phase difference value for light with a wavelength of 650 nm.)

[0311] (Example 2) The first phase difference layer (1) side of the first phase difference film (1) (MD direction length 380 mm × TD direction length 180 mm) with the substrate prepared above and the adhesive layer (1) side exposed by peeling off one separator film from the adhesive sheet (1) (380 mm × 180 mm) prepared above were laminated together using an automatic laminating machine HALTEC, and then the other separator film was peeled off. The adhesive layer (1) side exposed by peeling off the other separator film and the second phase difference layer side of the second phase difference film (1) (MD direction length 380 mm × TD direction length 180 mm) with the substrate prepared above were laminated together using an automatic laminating machine HALTEC to obtain a laminate (A2) consisting of substrate / alignment film / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / alignment film / substrate. Next, corona treatment (800W, 10m / min, bar width 700mm, 1 pass) was applied to the first protective layer surface of polarizing plate A. Then, the adhesive (1) prepared above was applied to the corona-treated surface using a coating machine (bar coater manufactured by Daiichi Rika Co., Ltd.). Furthermore, the substrate on the first phase difference film (1) side of the laminate (A2) (MD direction length 380mm × TD direction length 180mm) prepared above was peeled off, and the exposed surface and the first protective layer were bonded together using a bonding device ("LPA3301" manufactured by Fujipla Co., Ltd.). The substrate and alignment film of the first phase difference film were peeled off. From the laminate (A2) side, an ultraviolet irradiation device with a belt conveyor (using a "H bulb" lamp manufactured by Fusion UV Systems) was used to irradiate the UVA region at an intensity of 390mW / cm². 2 The cumulative light intensity is 420 mJ / cm². 2 Therefore, in the UVB region, the radiation level is 400 mW / cm². 2 The cumulative light intensity is 400 mJ / cm². 2 To achieve this, the adhesive layer (1) was cured by irradiating it with ultraviolet light, and a laminate (B2) was obtained consisting of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / alignment film / substrate. The thickness of the layer in which adhesive (1) had cured (hereinafter also referred to as the "first bonding layer") was measured and found to be 1.5 μm.

[0312] Next, the substrate was peeled off from the laminate (B2) to expose the surface (the surface on the first phase difference layer side), and the adhesive layer (1) surface, which was exposed by peeling off one of the separator films from the adhesive sheet (1) (380 mm x 180 mm) prepared above, were laminated together using an automatic laminating machine HALTEC. After that, the other separator film was peeled off. The substrate of the second phase difference film was peeled off, as was the alignment film. The other separator film was peeled off to expose the adhesive layer (1) surface, and the third phase difference layer surface of the third phase difference film with substrate (MD direction length 380 mm × TD direction length 180 mm) prepared above was laminated in sheet form using an automatic laminating machine HALTEC to obtain a laminate (C2) consisting of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / alignment film / substrate.

[0313] The substrate of the third phase difference film was peeled off from the obtained laminate (C2), and the exposed surface (the surface on the third phase difference layer side) and the adhesive layer exposed by peeling off one of the separator films from the adhesive sheet (2) (380 mm × 180 mm) prepared above were laminated together in a single sheet using an automatic laminating machine HALTEC to obtain an optical laminate (2) with a separator film, consisting of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / adhesive layer (2) / separator film. The substrate of the third phase difference film was peeled off, as was the alignment film.

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

[0315] (Example 4) An optical laminate with a separator film (4) was obtained in the same manner as in Example 1, except that the first phase difference film with a substrate (1) was changed to a first phase difference film with a substrate (3), the second phase difference film with a substrate (1) was changed to a second phase difference film with a substrate (2), and the third phase difference film with a substrate was not laminated. The laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first phase difference layer (3) / adhesive layer (1) / second phase difference layer (2) / adhesive layer (2) / separator film.

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

[0317] (Example 6) An optical laminate with a separator film (6) was obtained in the same manner as in Example 2, except that the first phase difference film with substrate (1) was changed to a first phase difference film with substrate (3), the second phase difference film with substrate (1) was changed to a second phase difference film with substrate (2), and the third phase difference film with substrate was not laminated. The laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first phase difference layer (3) / adhesive layer (1) / second phase difference layer (2) / adhesive layer (2) / separator film.

[0318] (Example 7) An optical laminate with a separator film (7) was obtained in the same manner as in Example 1, except that polarizer A was changed to polarizer B, and the laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / adhesive layer (2) / separator film.

[0319] (Example 8) An optical laminate with a separator film (8) was obtained in the same manner as in Example 2, except that polarizer A was changed to polarizer B, and the laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / adhesive layer (2) / separator film.

[0320] (Example 9) An optical laminate with a separator film (9) was obtained in the same manner as in Example 1, except that polarizer A was changed to polarizer B and the first phase difference film with substrate (1) was changed to the first phase difference film with substrate (2). The laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first phase difference layer (2) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / adhesive layer (2) / separator film.

[0321] (Example 10) An optical laminate with a separator film (10) was obtained in the same manner as in Example 1, except that polarizer A was changed to polarizer B, the first phase difference film (1) with a substrate was changed to the first phase difference film (3) with a substrate, the second phase difference film (1) with a substrate was changed to the second phase difference film (2) with a substrate, and the third phase difference film with a substrate was not laminated. The laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first phase difference layer (3) / adhesive layer (1) / second phase difference layer (2) / adhesive layer (2) / separator film.

[0322] (Example 11) An optical laminate with a separator film (11) was obtained in the same manner as in Example 2, except that polarizer A was changed to polarizer B and the first phase difference film (1) with a substrate was changed to the first phase difference film (2) with a substrate. The laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first phase difference layer (2) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / adhesive layer (2) / separator film.

[0323] (Example 12) An optical laminate with a separator film (12) was obtained in the same manner as in Example 2, except that polarizer A was changed to polarizer B, the first phase difference film (1) with a substrate was changed to the first phase difference film (3) with a substrate, the second phase difference film (1) with a substrate was changed to the second phase difference film (2) with a substrate, and the third phase difference film with a substrate was not laminated. The laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first phase difference layer (3) / adhesive layer (1) / second phase difference layer (2) / adhesive layer (2) / separator film.

[0324] (Example 13) An optical laminate with a separator film (13) was obtained in the same manner as in Example 1, except that polarizer A was changed to polarizer B, the first phase difference film (1) with a substrate was changed to the first phase difference film (4) with a substrate, the second phase difference film (1) with a substrate was changed to the second phase difference film (2) with a substrate, and the third phase difference film with a substrate was not laminated. The laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / first phase difference layer (4) / adhesive layer (1) / second phase difference layer (2) / adhesive layer (2) / separator film.

[0325] (Example 14) An optical laminate with a separator film (14) was obtained in the same manner as in Example 1, except that polarizer A was changed to polarizer C, and the laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer C / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / adhesive layer (2) / separator film.

[0326] (Example 15) An optical laminate with a separator film (15) was obtained in the same manner as in Example 2, except that polarizer A was changed to polarizer C, and the laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer C / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / adhesive layer (2) / separator film.

[0327] (Example 16) In the same manner as in Example 1, an optical laminate (16) with a separator film was obtained, consisting of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / adhesive layer (2) / separator film. This was done in the same manner as in Example 1, except that the first protective layer and the first phase difference film (1) were bonded together not with adhesive (1), but by peeling off one separator film from the adhesive sheet (1) (380 mm x 180 mm) and bonding the exposed adhesive layer (1) surface to the first protective layer using an automatic laminating machine HALTEC, and then peeling off the other separator film and bonding the exposed adhesive layer (1) surface to the first phase difference layer surface of the first phase difference film (1) using an automatic laminating machine HALTEC.

[0328] (Example 17) In the same manner as in Example 2, an optical laminate (17) with a separator film was obtained, consisting of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) / second phase difference layer (1) / adhesive layer (1) / third phase difference layer / adhesive layer (2) / separator film. This was done in the same manner as in Example 2, except that the first protective layer and the first phase difference film (1) with a substrate were bonded together not with adhesive (1), but by peeling off one separator film from the adhesive sheet (1) (380 mm x 180 mm) to expose the adhesive layer (1) surface, then bonding the first protective layer and the first phase difference film (1) with a substrate to an exposed adhesive layer (1) surface using an automatic laminating machine HALTEC, and then peeling off the other separator film to expose the adhesive layer (1) surface and bonding the first phase difference layer surface of the first phase difference film (1) to the first phase difference film (1) surface using an automatic laminating machine HALTEC.

[0329] (Example 18) The bonding of the first phase difference film with substrate and the second phase difference film with substrate, and the bonding of the second phase difference film with substrate and the third phase difference film with substrate, are performed not by an adhesive sheet (1), but by applying the adhesive (1) prepared above to the exposed surfaces (the surface on the first phase difference layer (1) side and the surface on the second phase difference layer (1) side) of the first phase difference film and the second phase difference film with substrate using a coating machine (bar coater manufactured by Daiichi Rika Co., Ltd.), thereby bonding the first phase difference layer (1) surface of the first phase difference film and the second phase difference layer surface of the second phase difference film, and An optical laminate with a separator film (18) was obtained in the same manner as in Example 1, except that the second phase difference layer (1) surface of the two-phase difference film and the third phase difference layer surface of the third phase difference film were bonded together using a bonding device ("LPA3301" manufactured by Fujipla Co., Ltd.). The laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) (thickness 1.5 μm) / second phase difference layer (1) / adhesive layer (1) (thickness 1.5 μm) / third phase difference layer / adhesive layer (2) / separator film.

[0330] (Example 19) The bonding of the first phase difference film with substrate and the second phase difference film with substrate, and the bonding of the second phase difference film with substrate and the third phase difference film with substrate, is performed not by an adhesive sheet (1), but by applying the adhesive (1) prepared above to the exposed surfaces (the surface on the first phase difference layer (1) side and the surface on the second phase difference layer (1) side) of the first phase difference film and the second phase difference film with substrate using a coating machine (bar coater manufactured by Daiichi Rika Co., Ltd.), thereby bonding the first phase difference layer (1) surface of the first phase difference film and the second phase difference layer surface of the second phase difference film, and the second phase difference An optical laminate with a separator film (19) was obtained in the same manner as in Example 2, except that the second phase difference layer (1) surface of the film and the third phase difference layer surface of the third phase difference film were bonded together using a bonding device ("LPA3301" manufactured by Fujipla Co., Ltd.). The laminate consisted of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer A / adhesive layer (1) / first phase difference layer (1) / adhesive layer (1) (thickness 1.5 μm) / second phase difference layer (1) / adhesive layer (1) (thickness 1.5 μm) / third phase difference layer / adhesive layer (2) / adhesive layer (2) / separator film.

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

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

[0333] (Comparative Example 1) The following modifications were made: polarizer A was changed to polarizer B; the first phase difference film (1) with substrate was changed to the first phase difference film (5) with substrate; the second phase difference film (1) with substrate was changed to the second phase difference film (4) with substrate; the third phase difference film with substrate was not laminated; instead of using adhesive (1) to bond the first protective layer and the first phase difference film (1) with substrate, one separator film was peeled off from the adhesive sheet (1) (380mm x 180mm) to expose the adhesive layer (1) surface, which was then laminated in a single sheet using the HALTEC automatic laminating machine; the other separator film was then peeled off to expose the adhesive layer (1) surface, which was then laminated in a single sheet using the HALTEC automatic laminating machine; and the bonding of the first phase difference film and the second phase difference film was done using adhesive sheet (1) Instead, the adhesive (1) prepared above was applied to the exposed surface (the surface on the first phase difference layer (1) side) after peeling off the substrate of the first phase difference film using a coating machine (bar coater manufactured by Daiichi Rika Co., Ltd.), and the first phase difference layer (1) surface of the first phase difference film and the second phase difference layer surface of the second phase difference film were bonded together using a bonding device ("LPA3301" manufactured by Fujipla Co., Ltd.). The alignment film was not peeled off when peeling off the substrates of the substrate-attached first phase difference film and the substrate-attached second phase difference film. In addition, an optical laminate with a separator film (R1) was obtained in the same manner as in Example 2, consisting of a second protective layer / adhesive layer (2) / polarizer / adhesive layer (2) / first protective layer B / adhesive layer (1) / alignment film / first phase difference layer (5) / adhesive layer (1) (thickness 1.5 μm) / second phase difference layer (4) / alignment film / adhesive layer (2) / separator film.

[0334] [evaluation] (Deformation defect) In the fabricated optical laminate with separator film, an inspection laminate was obtained in the same manner as before, except that the slow phase axis of the first phase difference film was laminated so that it was at a 45° clockwise angle from the viewing side with respect to the absorption axis of the polarizer. The separator film of the obtained inspection laminate was peeled off and laminated to alkali-free glass (Corning Eagle XG) to prepare an inspection laminate sample.

[0335] The surface of the separator film side of the fabricated optical laminate with separator film was observed by reflecting fluorescent light, and areas where minute deformations were visible were marked. Transmission observation was performed on the marked locations using an optical microscope (Olympus, product name BX53M), and markings where minute foreign matter of size 10 μm to 20 μm was observed were selected. Layer cross-sectional analysis was performed on the selected marking locations using a scanning white light interference microscope VS1000 (Hitachi High-Tech Science Corporation), and uniformity inspection was performed on the marking locations where minute foreign matter was confirmed in the bonding layer between the first protective layer and the first phase difference layer.

[0336] For the inspection of unevenness, the backlight (Shinkosha Co., Ltd. LED Viewer 5000A4) was set to normal mode (11800 lux) in a darkroom, and the inspection laminate sample was placed on the backlight with the second protective layer facing upwards (second protective layer facing the light source). The separator film was peeled off, and the optical laminate to be inspected for unevenness was positioned so that the exposed laminated layer faced the backlight. At this time, the absorption axis of the optical laminate to be inspected for unevenness was made parallel to the absorption axis of the inspection laminate sample. Unevenness was observed at the marking position where foreign matter was found in the first laminated layer between the first protective layer and the first phase difference layer in the layer cross-sectional analysis. Unevenness was evaluated according to the following criteria. The evaluation results are shown in each table. A: No unevenness is visible. B: The unevenness is almost invisible.

[0337] (Crack resistance) For the fabricated optical laminates with separator films, the separator films were peeled off, and each was bonded to a glass plate via the exposed bonding layer, and a thermal shock resistance test was performed. An Eriksen pen (Eriksen, model 318), set to a load of 10N, was pressed against the side of the polarizer in the optical laminate opposite to the glass plate to serve as the starting point. Similar starting points were established at two other locations (a total of three locations) at equal intervals. Subsequently, a thermal shock resistance test consisting of 30 minutes at -20°C and 30 minutes at 60°C was performed for 300 cycles using a TSA-303EL-W (ESPEC CORP.). The length of the cracks generated from each starting point where the Eriksen pen was pressed against the surface of the polarizer in the optical laminate before the thermal shock resistance test was measured, and the average value of the crack measurements from the three starting points was taken as the crack length (mm). Crack resistance was evaluated according to the following criteria. The evaluation results are shown in the respective tables. A+: Crack length is 1 mm or less. A: The crack length is greater than 1 mm and less than or equal to 3 mm. B: The crack length is greater than 3 mm and less than or equal to 5 mm. C: The crack length is greater than 5 mm.

[0338] (Scratch resistance) During the fabrication process of each optical laminate with separator films, the state of the peeling interface on the first phase difference film side when peeling the substrate from the first phase difference film was visually observed. The peeling speed when peeling the substrate was 30 m / min. The evaluation results are shown in the respective tables. A+: No damage was found at all. A: Almost no damage was found. B: Damage was found in a portion of the delamination interface.

[0339] (oblique color difference) The fabricated optical laminates with separator films were subjected to the removal of the separator films and bonded to inorganic glass plates (Corning, product name: Eagle XG) via the exposed bonding layer to create glass plates with circular polarizers. The resulting glass plates with circular polarizers were evaluated using a display evaluation system DMS803 (Instrument Systems GmbH) from a 50-degree inclination angle (50 degrees relative to the thickness direction of the circular polarizer) to determine the reflected hue a * and b * The measurement sample was rotated within the sample surface while measuring the reflected hue a. * and b * to, a * ―b * The color shift was obtained by plotting it in a coordinate system. For the measurement, the glass plate with the circular polarizer obtained above was placed on a glass plate (0.7 mm thick, Corning's "Eagle XG") and a reflector (reflectance: 96% or more, diffuse reflectance: 9% or less), with the second protective layer side facing up, and the measurement sample was taken with a layer configuration of reflector / air / glass plate / optical laminate. From the obtained color shift, a * The difference between the maximum and minimum values ​​is Δa * , b * The difference between the maximum and minimum values ​​is Δb * as Δa * b * The following formula was used to calculate the value, and the following categories were used for determination. Δa * b * =( Δa * )×(Δb * ) A:Δa * b * The number is less than 45. B:Δa * b * The value is 45 or higher. [Table 1]

[0340] [Table 2]

[0341] Table 3

[0342] Table 4

Claims

1. It comprises a first protective layer, a first bonding layer, and a first phase difference film, The first protective layer and the first phase difference film are bonded together via the first bonding layer. The first phase difference film includes a first phase difference layer but does not include a first orientation layer, or includes a first phase difference layer and a first orientation layer. The Martens hardness of the surface on the first protective layer side of the first phase difference layer is 100 N / mm². ２ That's all. An optical laminate in which the ratio of the Martens hardness of the surface on the first protective layer side of the first phase difference layer 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 phase difference layer is a cured product layer of a polymerizable liquid crystal compound.

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

4. The Martens hardness of the surface on the first protective layer side of the first phase difference layer is 170 N / mm². ２ The optical laminate according to claim 1 or 2.

5. The Martens hardness of the surface on the first protective layer side of the first phase difference layer is 250 N / mm². ２ The optical laminate according to claim 1 or 2, which is as follows:

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

7. The Martens hardness of the first protective layer is 80 N / mm² ２ The optical laminate according to claim 1 or 2.

8. The Martens hardness of the first protective layer is 140 N / mm². ２ The optical laminate according to claim 1 or 2, which is as follows:

9. The optical laminate according to claim 1 or 2, wherein the phase difference value Rth in the thickness direction of the first protective layer is 10 nm or more.

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

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. The device further comprises a second laminating layer and a second phase difference film, The first phase difference film and the second phase difference film are bonded together via the second bonding layer. The optical laminate according to claim 1 or 2, wherein the second phase difference film includes a second phase difference layer but does not include a second orientation layer, or includes a second phase difference layer and a second orientation layer.

14. The optical laminate according to claim 13, wherein the optical laminate comprising the first phase difference film, the second lamination layer, and the second phase difference film satisfies the following relationships (1) and (2). 100 ≤ Re(550) ≤ 180 (1) Re(450) / Re(550)≦1.0 (2) [In equations (1) and (2), Re(450) represents the in-plane phase difference value for light with a wavelength of 450 nm. Re(550) represents the in-plane phase difference value for light with a wavelength of 550 nm.

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

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

17. A step of preparing a first phase difference film including a first phase difference layer and a first orientation layer, The process includes providing a first protective layer on the surface of the first phase difference layer side of the first phase difference film via a first lamination layer to obtain a first optical laminate, The Martens hardness of the surface on the first protective layer side of the first phase difference layer is 100 N / mm². ２ That's all. A method for manufacturing an optical laminate, wherein the ratio of the Martens hardness of the surface of the first phase difference 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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