Optical laminate and image display device

Abstract

The invention provides an optical laminate and an image display device. The purpose of the present invention is to suppress a change over time in an in-plane phase difference characteristic and to suppress corrosion of a metal member provided in a bonded image display panel. An optical laminate (1) is provided with a first protective film (21), a polarizer (22), a second protective film (23), a phase element (4), and an adhesive layer (5) in this order. The moisture permeability of the second protective film (23) is 1200 g / (m < 2 > day) or less, and the adhesive layer (5) contains an antistatic agent. The antistatic agent includes an ionic compound including an organic cation and an anion represented by formula (1). (CnF2n + 1SO2) 2N-(1) (In the formula, n is an integer of 0-5. ).

Description

Technical Field

[0001] The present invention relates to an optical layered body and an image display device including the same. Background Art

[0002] In image display devices such as organic EL display devices, it is known to use a circular polarizing plate to improve antireflection performance in order to suppress a decrease in visibility due to reflection of external light (for example, Patent Document 1). The circular polarizing plate is an optical laminate including a polarizer and a phase element.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2019 / 160033 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the past, circular polarizing plates, especially in continued use at high temperatures, had the problem of changes in the in-plane phase difference characteristics. The in-plane phase difference characteristics represent the phase difference values ​​and wavelength dispersion of each wavelength, and changes in the reflected hue are produced due to their changes. In addition, when the circular polarizing plate is bonded to an image display panel, it is observed that the metal components of the image display panel are corroded for some reason. In particular, when an antistatic agent is included in the adhesive on the panel bonding surface, the above-mentioned problem tends to become significant. Therefore, the object of the present invention is to provide an optical laminate, which comprises a polarizer and a phase element, which can suppress the time-dependent changes in the in-plane phase difference characteristics, and suppress the corrosion of the metal components of the bonded image display panel. In addition, the object of the present invention is to provide an image display device having the optical laminate.

[0008] Means for solving problems

[0009] The inventors of the present invention have conducted research and found that the reason why the phase difference characteristics of the conventional circular polarizing plate change is that the iodine contained in the polarizer and the antistatic agent contained in the adhesive layer are transferred to the phase element. In addition, the inventors of the present invention have conducted research and found that the reason why the metal component of the image display panel is corroded when the conventional circular polarizing plate is attached to the image display panel is that the iodine contained in the polarizer and the antistatic agent contained in the adhesive layer invade the metal component. The inventors of the present invention have conducted research based on these ideas and have completed the invention shown below.

[0010] The present invention provides an optical laminate, which comprises a first protective film, a polarizing plate, a second protective film, a phase element, and an adhesive layer in sequence, wherein the moisture permeability of the second protective film is 1200 g / (m 2· days) or less, the adhesive layer contains an antistatic agent, and the antistatic agent includes an ionic compound, and the ionic compound includes an organic cation and an anion represented by the following formula (1).

[0011] (C n F 2n+1 SO2)2N - …(1)

[0012] (In the formula, n is an integer from 0 to 5.)

[0013] The optical layered body can appropriately suppress the iodine contained in the polarizing plate and the antistatic agent contained in the pressure-sensitive adhesive layer from moving across the layers in the optical layered body.

[0014] The optical layered body may have one or more of the following features.

[0015] The water vapor permeability coefficient of the phase element is 100 or less.

[0016] The phase element includes a first phase difference layer, a bonding adhesive layer, and a second phase difference layer, and has a λ / 4 plate function over the entire visible light region.

[0017] Adhesion The adhesive layer contains an active energy ray-curable adhesive.

[0018] The second protective film contains a cyclic polyolefin-based resin.

[0019] The thickness of the second protective film is 1 to 10 μm.

[0020] The moisture permeability of the first protective film is 100g / (m 2 · days) or more.

[0021] • Ionic compounds include organic cations containing nitrogen atoms.

[0022] The present invention also provides an image display device including the above-mentioned optical layered body and an image display panel to which the optical layered body is bonded.

[0023] Effects of the Invention

[0024] According to the present invention, an optical laminate can be provided, which includes a polarizing plate and a phase element, can suppress the time-dependent change of the in-plane phase difference characteristics, and suppress the corrosion of the metal components of the bonded image display panel. In addition, according to the present invention, an image display device having the optical laminate can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a cross-sectional view of an optical layered body according to one embodiment of the present invention. DETAILED DESCRIPTION

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0027] <Optical laminate>

[0028] (1) Summary

[0029] like Figure 1 As shown, the optical laminate 1 of this embodiment is a circular polarizing plate having a linear polarizing plate 2, a phase element 4 and an adhesive layer 5 in sequence. The term "circular polarizing plate" includes an elliptical polarizing plate. The optical laminate 1 can be used as an antireflection film in an image display device such as an organic electroluminescent (organic EL) display device. The linear polarizing plate 2 and the phase element 4 are laminated by bonding an adhesive layer 3 between the linear polarizing plate and the phase element.

[0030] The linear polarizing plate 2 includes a first protective film 21, a polarizer 22, and a second protective film 23 in this order. The first protective film 21 and the polarizer 22, and the polarizer 22 and the second protective film 23 are laminated by an adhesive layer (not shown) in the linear polarizing plate. It should be noted that the adhesive layer in the linear polarizing plate is optional, and the first protective film 21 and the polarizer 22, and the polarizer 22 and the second protective film 23 may be in direct contact.

[0031] Hereinafter, each component will be described in detail.

[0032] (2) Polarizer

[0033] The polarizing plate 22 is an optical film (linear polarizing plate) having the property of transmitting linearly polarized light having a vibration plane orthogonal to the absorption axis when non-polarized light is incident. Specifically, the polarizing plate 22 is a polyvinyl alcohol-based resin film (hereinafter also referred to as "PVA-based film") in which a dichroic pigment is adsorbed and oriented.

[0034] The polyvinyl alcohol-based resin (hereinafter, also referred to as "PVA-based resin") constituting the PVA-based film can be produced by saponifying a polyvinyl acetate-based resin. In addition to polyvinyl acetate which is a homopolymer of vinyl acetate, the polyvinyl acetate-based resin may also be a copolymer of vinyl acetate and other monomers copolymerizable with vinyl acetate. Other monomers copolymerizable with vinyl acetate include, for example, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, (meth)acrylamides having an ammonium group, and the like. It should be noted that, in the present specification, "(meth)acrylic acid" refers to either acrylic acid or methacrylic acid. The "(meth)" of (meth)acrylates, etc., also has the same meaning.

[0035] The saponification degree of PVA resin is usually about 85 to 100 mol%, preferably 98 mol% or more. PVA resin can be modified, for example, polyvinyl formal, polyvinyl acetal, etc. modified by aldehydes can also be used. The average polymerization degree of PVA resin is usually about 1000 to 10000, preferably about 1500 to 5000. The average polymerization degree of PVA resin can be calculated according to JIS K 6726 (1994). If the average polymerization degree is less than 1000, it is difficult to obtain the preferred polarization performance. If it exceeds 10000, the film processability is sometimes poor.

[0036] Polarizers are usually manufactured through the following steps: a step of uniaxially stretching a PVA film; a step of dyeing the PVA film with a dichroic dye to adsorb the dichroic dye; a step of treating the PVA film adsorbed with the dichroic dye with an aqueous boric acid solution to cross-link it; and a step of washing with water after the cross-linking treatment with an aqueous boric acid solution (hereinafter also referred to as boric acid treatment).

[0037] The uniaxial stretching of the PVA film can be performed before, at the same time as, or after dyeing with a dichroic pigment. In the case of uniaxial stretching after dyeing, the uniaxial stretching can be performed before or during the boric acid treatment. Of course, uniaxial stretching can also be performed in the multiple stages shown here. The uniaxial stretching can be performed by a method of uniaxial stretching along the film conveying direction between rollers with different peripheral speeds, a method of uniaxial stretching along the film conveying direction using a hot roller, a method of stretching along the width direction using a tenter, etc. In addition, the uniaxial stretching can be performed by dry stretching in the atmosphere, or by wet stretching in a state where the PVA film is swollen using a solvent such as water. The stretching ratio is usually about 3 to 8 times.

[0038] The dyeing utilizing the dichroic pigment of the PVA system film can be carried out by, for example, dipping the PVA system film in an aqueous solution containing the dichroic pigment. As the dichroic pigment, specifically, iodine or dichroic organic dyes can be used. It should be noted that the PVA system film is preferably immersed in water in advance before the dyeing process to make it swell.

[0039] When iodine is used as a dichroic pigment, a method of dyeing the PVA film by immersing it in an aqueous solution containing iodine and potassium iodide is generally adopted. The content of iodine in the aqueous solution is generally about 0.01 to 1 mass part relative to 100 mass parts of water, and the content of potassium iodide is generally about 0.5 to 20 mass parts relative to 100 mass parts of water. The temperature of the aqueous solution used in dyeing is generally about 20 to 40°C. In addition, the immersion time (dyeing time) in the aqueous solution is generally about 20 to 1,800 seconds.

[0040] On the other hand, when using a dichroic organic dye as a dichroic pigment, a method of dyeing by immersing the PVA film in an aqueous solution containing a water-soluble dichroic organic dye is generally adopted. The content of the dichroic organic dye in the aqueous solution is generally about 0.0001 to 10 parts by mass, preferably 0.001 to 1 part by mass, relative to 100 parts by mass of water. The dye aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing auxiliary. The temperature of the dichroic organic dye aqueous solution used in dyeing is generally about 20 to 80°C. In addition, the immersion time (dyeing time) in the aqueous solution is generally about 10 to 1,800 seconds.

[0041] The boric acid treatment after dyeing with a dichroic pigment can be carried out by immersing the dyed PVA film in an aqueous solution containing boric acid. The content of boric acid in the aqueous solution containing boric acid is generally about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, relative to 100 parts by mass of water. When iodine is used as a dichroic pigment, the aqueous solution containing boric acid preferably contains potassium iodide. The content of potassium iodide in the aqueous solution containing boric acid is generally about 0.1 to 15 parts by mass, preferably 5 to 12 parts by mass, relative to 100 parts by mass of water. The immersion time in the aqueous solution containing boric acid is generally about 60 to 1,200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the aqueous solution containing boric acid is generally above 50°C, preferably 50 to 85°C, and more preferably 60 to 80°C.

[0042] The PVA film after the boric acid treatment is usually subjected to a water washing treatment. The water washing treatment can be performed, for example, by immersing the PVA film treated with boric acid in water. The temperature of the water in the water washing treatment is usually about 5 to 40° C. In addition, the immersion time is usually about 1 to 120 seconds.

[0043] After washing, drying treatment is implemented to obtain a polarizer. Drying treatment can be carried out using a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually about 30 to 100° C., preferably 50 to 80° C. The time of the drying treatment is usually about 60 to 600 seconds, preferably 120 to 600 seconds. By drying treatment, the moisture content in the polarizer is reduced to a practical level. Its moisture content is usually about 5 to 20% by mass relative to 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 it can suppress damage or breakage after drying. In addition, if the moisture content is less than 20% by mass, the polarizer has sufficient thermal stability.

[0044] As described above, a polarizing plate in which a dichroic dye is adsorbed and oriented on a PVA-based film can be produced.

[0045] The visibility-corrected polarization degree Py of the polarizer is usually 95% or more, preferably 97% or more, more preferably 98% or more, further preferably 98.7% or more, further preferably 99.0% or more, particularly preferably 99.4% or more, and can be 99.9% or more. The visibility-corrected polarization degree Py of the polarizer can be 99.99% or less. The visibility-corrected polarization degree Py can be calculated by using a spectrophotometer with an integrating sphere ("V7100" manufactured by JASCO Corporation) and performing visibility correction on the obtained polarization degree using the 2-degree field of view (C light source) of "JIS Z8701".

[0046] Increasing the visibility correction polarization degree Py of the polarizing plate is advantageous in improving the function of the optical laminate as an antireflection film and the durability of the optical laminate. If the visibility correction polarization degree Py of the polarizing plate is less than 95%, the polarizing plate may not function as an antireflection film.

[0047] The thickness of the polarizer is 15 μm or less, preferably 13 μm or less, and more preferably 10 μm or less. If the thickness of the polarizer is within this range, it is beneficial to the thinning of the optical laminate, and in addition, the phase difference variation can be more effectively suppressed. The thickness of the polarizer is usually 2 μm or more, preferably 3 μm or more, for example, 5 μm or more.

[0048] (3) First protective film

[0049] The first protective film 21 has the function of protecting the surface of the polarizer 22. The first protective film 21 can be laminated in direct contact with the surface of the polarizer 22, or can be laminated via an adhesive layer in the linear polarizing plate. In order to improve the adhesion with the polarizer 22, the first protective film 21 can be subjected to surface treatment (such as corona treatment), or a thin layer such as a primer layer (also called an easy-adhesion layer) can be formed.

[0050] The thickness T1 of the first protective film is usually 60 μm or less, preferably 50 μm or less, more preferably 40 μm or less, preferably 10 μm or more, more preferably 15 μm or more, and further preferably 20 μm or more from the viewpoint of suppressing curling of the entire polarizing plate under a durable environment.

[0051] As the first protective film, for example, a resin film having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, stretchability, etc. can be used. The resin film can be a thermoplastic resin film. Specific examples of such thermoplastic resins include:

[0052] Cellulose ester resins such as triacetyl cellulose;

[0053] Polyester resins such as polyethylene terephthalate and polyethylene naphthalate;

[0054] Polyethersulfone resin;

[0055] Polysulfone resin;

[0056] Polycarbonate resin;

[0057] Polyamide resins such as nylon and aromatic polyamide;

[0058] Polyimide resin;

[0059] Chain polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer;

[0060] Cyclic polyolefin resins having a ring system and a norbornene structure (also called norbornene resins);

[0061] (Meth) acrylic resins such as polymethyl methacrylate;

[0062] Polyarylate resin;

[0063] Polystyrene resin;

[0064] Polyvinyl alcohol resin,

[0065] and mixtures thereof.

[0066] The protective film comprising the above-mentioned thermoplastic resin is commercially available.

[0067] Examples of the chain polyolefin-based resins include, in addition to homopolymers of chain olefins such as polyethylene resins (polyethylene resins as homopolymers of ethylene, copolymers mainly composed of ethylene) and polypropylene resins (polypropylene resins as homopolymers of propylene, copolymers mainly composed of propylene), copolymers containing two or more chain olefins.

[0068] Cyclic polyolefin resin is a general term for resins polymerized with cyclic olefin as a polymerization unit, and examples thereof include resins described in Japanese Patent Publication No. 1-240517, Japanese Patent Publication No. 3-14882, Japanese Patent Publication No. 3-122137, etc. If specific examples of cyclic polyolefin resins are given, they are ring-opening (co)polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers of cyclic olefins with chain olefins such as ethylene and propylene (representatively, random copolymers), and graft polymers obtained by modifying them with unsaturated carboxylic acids and their derivatives, and their hydrogenated products. Among them, it is preferred to use a norbornene resin using a norbornene monomer such as norbornene and a polycyclic norbornene monomer as the cyclic olefin.

[0069] Polyester resins are resins having an ester bond in the main chain, and are generally polycondensates of polycarboxylic acids or their derivatives and polyols. As polycarboxylic acids or their derivatives, dibasic dicarboxylic acids or their derivatives can be used, such as terephthalic acid, isophthalic acid, dimethyl terephthalate, dimethyl naphthalate, etc. As polyols, dibasic diols can be used, such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol, cyclohexanedimethanol, etc. As a representative example of polyester resins, polyethylene terephthalate, which is a polycondensate of terephthalic acid and ethylene glycol, can be cited.

[0070] Cellulose ester resins are esters of cellulose and fatty acids. Specific examples of cellulose ester resins include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. In addition, copolymers having a plurality of polymerized units constituting these cellulose ester resins and polymers in which a portion of the hydroxyl groups is modified by other substituents can also be cited. Among them, cellulose triacetate (triacetyl cellulose) is particularly preferred.

[0071] (Meth)acrylic resins are resins whose main constituent monomers are compounds having (meth)acryloyl groups. Specific examples of (meth)acrylic resins include poly(meth)acrylic acid esters such as polymethyl methacrylate; methyl methacrylate-(meth)acrylic acid copolymers; methyl methacrylate-(meth)acrylic acid ester copolymers; methyl methacrylate-acrylate-(meth)acrylic acid copolymers; methyl (meth)acrylate-styrene copolymers (MS resins, etc.); copolymers of methyl methacrylate and compounds having alicyclic hydrocarbon groups (e.g. methyl methacrylate-cyclohexyl methacrylate copolymers, methyl methacrylate-norbornyl (meth)acrylate copolymers, etc.). It is preferred to use a polymer having poly(meth)acrylic acid C1-C6 alkyl esters such as poly(meth)acrylate as the main component, and it is more preferred to use a methyl methacrylate resin having methyl methacrylate as the main component (50 to 100% by mass, preferably 70 to 100% by mass).

[0072] The polycarbonate resin includes a polymer in which monomer units are bonded via a carbonate group. The polycarbonate resin may be a resin called a modified polycarbonate in which the polymer skeleton is modified, a copolymer polycarbonate, or the like.

[0073] The first protective film may be formed by stretching a film containing the above-mentioned thermoplastic resin. As stretching treatment, uniaxial stretching, biaxial stretching, etc. may be cited. As stretching directions, the mechanical flow direction (MD) of the unstretched film, the direction (TD) orthogonal thereto, the direction oblique to the mechanical flow direction (MD), etc. may be cited. Biaxial stretching may be simultaneous biaxial stretching in two stretching directions, or may be sequential biaxial stretching in which the film is stretched in a specified direction and then stretched in other directions. The stretching treatment may be carried out, for example, as follows: using two or more pairs of clamping rollers with increased circumferential speeds on the outlet side, stretching is performed in the length direction (mechanical flow direction: MD), or the two side ends of the unstretched film are gripped with a chuck and extended in a direction (TD) orthogonal to the mechanical flow direction. At this time, by adjusting the thickness of the film or adjusting the stretching ratio, the phase difference value and the wavelength dispersion value can be controlled. In addition, by adding a wavelength dispersion regulator to the resin, the wavelength dispersion value can be controlled.

[0074] The first protective film may contain any appropriate additives according to the purpose. As additives, for example, antioxidants such as hindered phenol, phosphorus, and sulfur, light stabilizers, ultraviolet absorbers, weather stabilizers, and heat stabilizers; reinforcing materials such as glass fiber and carbon fiber; near-infrared absorbers; flame retardants such as tris (dibromopropyl) phosphate, triallyl phosphate, and antimony oxide; antistatic agents such as anionic, cationic, and nonionic surfactants; colorants such as inorganic pigments, organic pigments, and dyes; organic fillers, inorganic fillers; resin modifiers; plasticizers; lubricants; phase difference reducers, etc. The type, combination, and content of the additives contained can be appropriately set according to the purpose and the desired characteristics.

[0075] In addition, in order to impart the desired surface optical properties or other features, a coating layer (surface treatment layer) can be provided on the outer surface of the first protective film. Specific examples of the surface treatment layer include hard coating, anti-glare layer, anti-reflection layer, antistatic layer, antifouling layer. The method for forming the surface treatment layer is not particularly limited, and known methods can be used. The surface treatment layer can be formed on one side of the first protective film, and can also be formed on both sides.

[0076] The hard coating layer has the function of increasing the surface hardness of the first protective film and is provided for the purpose of preventing scratches on the surface, etc. The hard coating layer preferably has a pencil hardness of H or a value harder than H as measured by a pencil hardness test (a protective film having a hard coating layer is placed on a glass plate and measured) specified in JIS K 5600-5-4:1999 "General Test Methods for Coatings - Part 5: Mechanical Properties of Coatings - Section 4: Scratch Hardness (Pencil Method)".

[0077] The material forming the hard coat layer is usually cured by heat or light. For example, organic hard coat materials such as silicone, melamine, epoxy, (meth) acrylic, and urethane (meth) acrylate, and inorganic hard coat materials such as silicon dioxide can be cited. Among them, urethane (meth) acrylate or multifunctional (meth) acrylate hard coat materials are preferably used from the aspects of good adhesion to the protective film and excellent productivity.

[0078] The hard coat layer may contain various fillers for the purpose of adjusting the refractive index, improving the bending elastic modulus, stabilizing the volume shrinkage, and improving heat resistance, antistatic properties, antiglare properties, etc. In addition, the hard coat layer may also contain additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, leveling agents, and defoaming agents.

[0079] In order to further improve the strength, the hard coating layer may contain additives. The additives are not limited, and inorganic particles, organic particles, or mixtures thereof may be cited. In addition, in order to have hardness, the thicker the hard coating layer, the better. However, if it is too thick, it is easy to break during cutting, so it can be 1 μm to 20 μm, or 2 μm to 10 μm. The thickness of the hard coating layer is preferably set to 3 μm to 7 μm.

[0080] The antiglare layer is a layer having fine concavo-convex shapes on the surface, and is preferably formed using the above-mentioned hard coating material.

[0081] The anti-glare layer having fine concavo-convex shapes on the surface can be formed by 1) forming a coating film containing microparticles on a protective film and providing concavo-convex shapes based on the microparticles; 2) forming a coating film containing microparticles or not containing microparticles on a protective film and then pressing it on a mold (roller, etc.) having a concavo-convex shape on the surface to transfer the concavo-convex shape (also called embossing method), etc.

[0082] The anti-reflection layer is a layer used to reduce the reflection of external light on the surface of the protective film for people observing the protective film, and the reflectivity of visible light is usually less than 1.5%. This anti-reflection layer with a reflectivity is typically formed by laminating a high refractive index layer with a high refractive index and a low refractive index layer with a low refractive index, or using the method and materials described in Japanese Patent Publication No. 2021-6929. By adjusting these refractive indices and the thickness of each layer, the reflected light from each layer can be mutually weakened, and an excellent anti-reflection function can be exerted.

[0083] The anti-reflection layer comprising a high refractive index layer and a low refractive index layer is described in detail later. If a coating composition capable of forming a high refractive index layer and a low refractive index layer is used to manufacture the anti-reflection layer, the operation is extremely simple, so it is preferred. Here, an example of a coating composition capable of forming a high refractive index layer and a low refractive index layer is listed. The coating composition is liquid and comprises a suitable curable resin and an additive as required. The coating composition capable of forming a high refractive index layer (composition for forming a high refractive index layer) is, for example, a curable resin such as urethane acrylate and an initiator (photopolymerization initiator) for photopolymerization such as acetophenone system, benzophenone system, benzyl dimethyl ketal system, α-hydroxyalkyl phenone system, α-aminoalkyl phenone system, thioxanthone system are dissolved in a solvent such as methyl ethyl ketone and methyl isobutyl ketone. In order to make the coating property better, a leveling agent, preferably a fluorine-based leveling agent, can be included. In addition, as a coating composition (low refractive index layer forming composition) capable of forming a low refractive index layer, silica particles are dispersed in a solution, wherein the solution is a binder resin such as polyethylene glycol diacrylate, pentaerythritol (tri / tetra) acrylate as a curable resin, and an initiator (photopolymerization initiator) for photopolymerization such as acetophenone, benzophenone, benzyl dimethyl ketal, α-hydroxyalkyl phenone, α-aminoalkyl phenone, thioxanthone are dissolved in a solvent such as 1-methoxy-2-propyl acetate and methyl isobutyl ketone. In order to make the coating property better, a fluorine-based leveling agent can be included. It should be noted that the coating composition capable of forming a high refractive index layer and a low refractive index layer respectively listed here is only an example, and it is preferred that the high refractive index layer forming composition and the low refractive index layer forming composition are optimized respectively according to the characteristics of the anti-reflection layer to be formed.

[0084] The antireflection layer may include, for example, a low refractive index layer. Alternatively, the antireflection layer may have a multilayer structure further including a high refractive index layer and / or a medium refractive index layer between the protective film and the low refractive index layer.

[0085] The low refractive index layer can be formed by applying a coating liquid containing a cured product of the above-mentioned curable resin, a light-transmitting resin such as a metal alkoxide polymer, and inorganic particles, and then curing the coating layer as needed. As inorganic particles, for example, low refractive particles such as LiF (refractive index 1.4), MgF (refractive index 1.4), 3NaF·AlF (refractive index 1.4), AlF (refractive index 1.4), Na3AlF6 (refractive index 1.33), hollow silica particles, etc. can be cited.

[0086] The antistatic layer is provided for the purpose of imparting conductivity to the surface of the first protective film and suppressing the influence caused by static electricity. The antistatic layer can be formed, for example, by coating a resin composition containing a conductive substance (antistatic agent) on the first protective film. For example, an antistatic hard coating can be formed by allowing an antistatic agent to coexist in the hard coating material for forming the hard coating.

[0087] The antifouling layer is provided to impart hydrophobicity, oleophobicity, sweat resistance, antifouling properties, etc. Suitable materials for forming the antifouling layer are fluorine-containing organic compounds. As fluorine-containing organic compounds, fluorocarbons, perfluorosilanes, and their polymer compounds, etc., can be cited. The formation method of the antifouling layer can use physical vapor deposition, chemical vapor deposition, wet coating, etc., with evaporation and sputtering as representative examples, according to the material to be formed. The average thickness of the antifouling layer is usually about 1 to 50 nm, preferably 3 to 35 nm.

[0088] When the optical laminate is applied to an image display device, the diffusion of dichroic pigments such as iodine in the polarizer 22 sometimes causes corrosion of metal components (electrodes, etc.) present near the optical laminate in the image display device. This is due to the transfer of dichroic pigments such as iodine to the metal components through the above-mentioned diffusion. In order to suppress the corrosion of the metal components, it is preferred to suppress the transfer amount of the dichroic pigment to the metal components.

[0089] The moisture permeability of the first protective film is preferably 100 g / (m 2 The moisture permeability is preferably 100g / (m 2 ·day) and above and 2000g / (m 2 ·day) or less, more preferably 200g / (m 2 ·day) and above and 1000g / (m 2 ·day) or less, more preferably 300g / (m 2 ·day) and above and 500g / (m 2 · days). When iodine contained in the polarizer moves between the layers of the optical laminate 1, if the moisture permeability of the first protective film 21 is too low, there is a tendency that the movement of iodine is excessively suppressed and tends to move in the opposite direction (phase element side). In addition, if the moisture permeability of the first protective film 21 is too high, there is a tendency that the polarizer is easily degraded by moisture and heat. Therefore, in the case where iodine moves to the side of the first protective film 21, in order to diffuse iodine to the outside of the optical laminate 1 through the first protective film 21, it is preferred that the moisture permeability of the first protective film is appropriately high.

[0090] (4) Second protective film

[0091] The second protective film 23 has the function of protecting the surface of the polarizer 22. The second protective film 23 can be laminated in direct contact with the surface of the polarizer 22, or can be laminated via an adhesive layer in the linear polarizing plate. In order to improve the adhesion with the polarizer 22, the second protective film 23 can be subjected to surface treatment (e.g., corona treatment), or a thin layer such as a primer layer (also referred to as an easy-adhesion layer) can be formed.

[0092] The moisture permeability of the second protective film 23 is 1200 g / (m 2 The moisture permeability is preferably 0.1 g / (m 2 ·day) and above and 800g / (m 2 ·day) or less, more preferably 0.5g / (m 2 ·day) and above and 500g / (m 2 ·day) or less, more preferably 1g / (m 2 ·day) and above and 100g / (m 2 ·day) or less, particularly preferably 10g / (m 2 ·day) and above and 50g / (m 2 If the moisture permeability of the second protective film 23 is within this range, the transfer of iodine to the phase element side can be sufficiently suppressed. In addition, if the moisture permeability of the second protective film 23 is 10 g / (m 2 · days) or more, it is also preferred from the viewpoint of Δα described later. It should be noted that the moisture permeability of the second protective film 23 can be measured according to the description of [Examples].

[0093] The thickness T2 of the second protective film is, for example, 0.1 to 60 μm, preferably 0.2 to 30 μm. It is advantageous for the present embodiment that the thickness T2 of the second protective film has a moderate thinness. That is, when the antistatic agent contained in the adhesive layer described later moves between the layers of the optical laminate 1, when the thickness of the second protective film 23 is too large, there is a tendency that the movement of the antistatic agent is excessively suppressed and tends to move in the opposite direction (image display panel side). Therefore, from the viewpoint of suppressing the corrosion of metal components, the thickness T2 of the second protective film is preferably 1 to 10 μm, more preferably 2 to 8 μm, and further preferably 3 to 5 μm.

[0094] As the second protective film, for example, a resin film having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, stretchability, etc. can be used. The resin film can be a thermoplastic resin film. The specific examples of such thermoplastic resins are the same as those described for the first protective film. Protective films containing thermoplastic resins can be obtained from the market.

[0095] The thermoplastic resin constituting the thermoplastic resin film used as the second protective film and the thermoplastic resin layer described later is preferably a cyclic polyolefin resin, a polyester resin, a polycarbonate resin, a (meth)acrylic resin, or a polystyrene resin, more preferably a cyclic polyolefin resin, a (meth)acrylic resin, or a polystyrene resin, further preferably a cyclic polyolefin resin or a (meth)acrylic resin, and still more preferably a cyclic polyolefin resin.

[0096] The thermoplastic resin film used as the second protective film may be a film existing as a monomer, in which case the thermoplastic resin film is laminated on the polarizer 22 via a linear polarizing plate internal adhesive layer as needed. Alternatively, the second protective film may be a thermoplastic resin layer. For example, a composition containing a thermoplastic resin is coated on a supporting substrate, dried as needed to obtain a thermoplastic resin layer with a supporting substrate, and the thermoplastic resin layer with a supporting substrate is bonded to the polarizer 22 via a linear polarizing plate internal adhesive layer as needed, and then the supporting substrate is peeled off and removed, thereby being able to laminate a thermoplastic resin layer as the second protective film on the polarizer 22 (first method).

[0097] When the second protective film is a thermoplastic resin layer, the composition can also be directly applied to the surface of the polarizer 22, and dried as needed to form a thermoplastic resin layer (second method). Among them, when the composition contains a solvent, the first method is preferred from the aspect of easily and stably forming a thermoplastic resin layer with a sufficiently reduced solvent content.

[0098] The second protective film can be a cured resin layer of a cured product containing a curable resin. As a curable resin, a thermosetting resin and an active energy curable resin can be cited, for example, (meth) acrylic resin, epoxy resin, oxetane resin, urethane resin, (meth) acrylic urethane resin, melamine resin, etc. can be cited. The cured resin layer of a cured product containing a curable resin can be formed by applying a composition containing a curable resin to a supporting substrate, drying it as needed, and then heating 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 cured resin layer with a supporting substrate is bonded to the polarizer 22 via a linear polarizing plate inner adhesive layer as needed, and then the supporting substrate is peeled off and removed, thereby being able to stack a cured resin layer as the second protective film on the polarizer 22.

[0099] From the viewpoint of moisture permeability or from the viewpoint of suppressing the change in phase difference characteristics, the second protective film is preferably a thermoplastic resin film or thermoplastic resin layer formed of a cyclic polyolefin resin, a thermoplastic resin film or thermoplastic resin layer formed of a (meth) acrylic resin, a cured resin layer containing a cured product of a (meth) acrylic resin, or a thermoplastic resin film or thermoplastic resin layer formed of a polystyrene resin. If further consideration is given to suppressing the transfer of the dichroic pigment in the polarizer 22 to the above-mentioned metal member, the second protective film is more preferably a thermoplastic resin film or thermoplastic resin layer formed of a cyclic polyolefin resin, or a thermoplastic resin film or thermoplastic resin layer formed of a polystyrene resin.

[0100] The second protective film may contain any appropriate additive according to the purpose. Specific examples of the additive are the same as those described for the first protective film.

[0101] The second protective film is preferably a film without phase difference characteristics or with a small phase difference value. Specifically, the in-plane phase difference value of the second protective film at a wavelength of 550nm is preferably less than 10nm. The in-plane phase difference value is greater than 0nm. In addition, the phase difference value in the thickness direction of the second protective film at a wavelength of 550nm is preferably -10nm to +10nm.

[0102] (5) Phase element

[0103] The phase element 4 is an optical element that shows a phase difference in the plane or in the thickness direction, and preferably includes a phase difference film. The phase difference film is a film that shows a phase difference in the plane or in the thickness direction, and is a layer (cured layer) formed by a polymer of a polymerizable liquid crystal compound, or a combination of the layer and an oriented film. The phase difference film, for example, includes a cured layer of a phase difference film-forming composition containing a polymerizable liquid crystal compound.

[0104] When the phase element 4 includes a phase difference film, the dichroic pigment transfers to the above-mentioned metal component, and the above-mentioned corrosion of the metal component becomes easy to occur. However, according to the present invention, the above-mentioned corrosion can be effectively suppressed even when the phase element 4 includes a phase difference film. In addition, if the phase element 4 includes a phase difference film, it is advantageous to reduce the thickness of the optical laminate, and the phase element 4 including a phase difference film is preferred in that the wavelength dispersion characteristics can be arbitrarily designed.

[0105] The phase element 4 in the optical laminate 1 of the present embodiment is formed by having two phase difference films (hereinafter also referred to as "phase difference layers"). That is, the first phase difference layer 41 and the second phase difference layer 43 are stacked by bonding the adhesive layer 42 in the phase element. It should be noted that in this specification, the phase difference films possessed by the phase element 4 are sometimes referred to as "the first phase difference layer" and "the second phase difference layer" in the order close to the linear polarizing plate 2. The following is an explanation of the contents that can be adopted as the configuration of the phase element 4.

[0106] (5-1) Retardation Film

[0107] The phase difference film is usually formed by coating a phase difference film forming composition on an oriented film formed on a substrate, and polymerizing the polymerizable liquid crystal compound contained in the phase difference film forming composition. The phase difference film is usually a film formed by curing the polymerizable liquid crystal compound in an oriented state. In order to produce a phase difference in the observation surface, it is necessary to be a cured film formed by polymerizing the polymerizable group of the polymerizable liquid crystal compound in a state where the polymerizable liquid crystal compound is oriented in a horizontal direction relative to the substrate surface. At this time, if the polymerizable liquid crystal compound is a rod-shaped liquid crystal, it only needs to be a positive A plate, and if the polymerizable liquid crystal compound is a disc-shaped liquid crystal, it only needs to be a negative A plate.

[0108] The phase element may include more than two layers of phase difference films with different optical anisotropies. In order to highly realize the anti-reflection function, it is sufficient to have a λ / 4 plate function (i.e., a phase difference function of π / 2) in the entire visible light region. Specifically, a reverse wavelength dispersion λ / 4 phase difference layer is preferred, or a combination of two or more phase difference films with different orientations is preferred. For example, a phase difference film with a λ / 2 plate function (i.e., a phase difference function of π) can be combined with a phase difference film with a λ / 4 plate function (i.e., a phase difference function of π / 2). In addition, from the viewpoint of being able to compensate for the anti-reflection function in the tilted direction, it is preferred to further include a layer having anisotropy in the thickness direction (positive C plate). In particular, when the phase element is composed of a reverse wavelength dispersion λ / 4 phase difference layer and a positive C plate, the effect of the present invention can be more significantly obtained. In addition, each phase difference film can be tilted oriented or a cholesteric orientation state can be formed.

[0109] When the phase element is a combination of two or more phase difference films with different orientations, the bonding can be performed via the phase element intra-bonding adhesive layer 42. From the viewpoint of suppressing corrosion of metal components of the image display panel to which the optical laminate is bonded, the phase element intra-bonding adhesive layer 42 is preferably an adhesive layer with low moisture permeability.

[0110] In the optical laminate 1, the iodine contained in the polarizer 22 and the antistatic agent contained in the adhesive layer 5 described later can move between layers and be transferred to the phase element. At this time, when the phase difference film contains a polymerizable liquid crystal compound, the phase difference characteristics change (for example, increase) due to the influence of iodine and the antistatic agent. From this point of view, the water vapor permeability coefficient of the phase element is preferably 100 or less. The water vapor permeability coefficient is preferably greater than 1 and less than 75, more preferably greater than 5 and less than 50, and further preferably greater than 10 and less than 35. Here, the "water vapor permeability coefficient" refers to the moisture permeability of the phase element at 65°C (unit: g / (m 2 ·day)) and the value represented by the product of the thickness (in mm). When iodine and the antistatic agent move between the layers of the optical laminate 1, when the water vapor permeability coefficient of the phase element 4 is too high, the movement of iodine and the antistatic agent becomes larger, and there is a tendency that the degree of suppression of the phase difference change of the first phase difference layer or the second phase difference layer that should suppress the phase difference change, and the effect of suppressing the corrosion of the metal component are lower than the original suppression effect. In addition, when the water vapor permeability coefficient is too low, the antistatic agent is difficult to penetrate excessively, so the antistatic agent is easy to move to the metal component. Therefore, it is preferred that the water vapor permeability coefficient of the phase element is moderately low.

[0111] When the in-plane phase difference value relative to light of wavelength λnm is defined as Re(λ), the λ / 4 function of the phase element in the entire visible light region preferably satisfies the optical characteristics represented by the following formula (1), and preferably satisfies the optical characteristics represented by the following formula (1), the following formula (2), and the following formula (3). The in-plane phase difference value Re(λ) of the phase element is a value measured by a phase difference measuring device (manufactured by Oji Scientific Instruments Co., Ltd., KOBRA-WPR) by stacking linear polarizing plates and phase elements in this order.

[0112] 100nm<Re(550)<160nm (1)

[0113] (Wherein, Re(550) represents the in-plane phase difference value (in-plane retardation) with respect to light of wavelength 550 nm.)

[0114] Re(450) / Re(550)≤1.0 (2)

[0115] 1.00≤Re(650) / Re(550) (3)

[0116] (Wherein, Re(450) represents the in-plane phase difference value relative to light with a wavelength of 450 nm, Re(550) represents the in-plane phase difference value relative to light with a wavelength of 550 nm, and Re(650) represents the in-plane phase difference value relative to light with a wavelength of 650 nm.)

[0117] The value of the wavelength dispersion α of the phase element is preferably a value within a specified range. Here, "wavelength dispersion α" refers to the ratio of the in-plane phase difference value Re(450) at a wavelength of 450nm to the in-plane phase difference value Re(550) at a wavelength of 550nm (Re(450) / Re(550)). From the perspective of improving the inverse wavelength dispersion and further improving the optical properties of the optical laminate, the value of the wavelength dispersion α is preferably above 0.70, and more preferably above 0.78. In addition, for the same reason, the wavelength dispersion α is preferably below 0.92, more preferably below 0.90, further preferably below 0.88, and particularly preferably below 0.87. The value of "Re(450) / Re(550)" can be arbitrarily adjusted by adjusting the mixing ratio of the polymerizable liquid crystal compound, the stacking angle of multiple phase difference films, and the phase difference value.

[0118] The in-plane phase difference value of the phase difference film can be adjusted by the thickness of the phase difference film. The in-plane phase difference value is determined by the following formula (4), so in order to obtain the desired in-plane phase difference value (Re (λ)), it is only necessary to adjust Δn (λ) and thickness d. The thickness of the phase difference film is preferably 0.5 μm to 5 μm, more preferably 1 μm to 3 μm. The thickness of the phase difference film can be measured using an interference film thickness meter, a laser microscope or a stylus film thickness meter. It should be noted that Δn (λ) depends on the molecular structure of the polymerizable liquid crystal compound described later.

[0119] Re(λ)=d×Δn(λ) (4)

[0120] (Where Re(λ) represents the in-plane phase difference at a wavelength of λnm, d represents the thickness, and Δn(λ) represents the birefringence at a wavelength of λnm.)

[0121] The positive C plate is not particularly limited as long as it has anisotropy in the thickness direction, and has the optical properties represented by formula (5) when tilt orientation or cholesteric orientation is not performed.

[0122] nx≈ny<nz (5)

[0123] The in-plane phase difference value Re(550) of the positive C plate at a wavelength of 550nm is usually in the range of 0 to 10nm, preferably in the range of 0 to 5nm. In addition, the phase difference value Rth(550) in the thickness direction at a wavelength of 550nm is usually in the range of -170nm to -10nm, preferably -150nm to -20nm, and more preferably -100nm to -40nm. If the phase difference value in the thickness direction is within this range, the anti-reflection properties from the oblique direction can be further improved.

[0124] The polymerizable liquid crystal compound contained in the phase difference film forming composition refers to a liquid crystal compound having a polymerizable group, particularly a photopolymerizable group. As the polymerizable liquid crystal compound, a polymerizable liquid crystal compound known in the past can be used. A photopolymerizable group refers to a group that can participate in a polymerization reaction by reactive species, such as active free radicals, acids, etc., generated by a photopolymerization initiator. As a photopolymerizable group, vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, oxirane, oxetane, etc. can be cited. Among them, acryloyloxy, methacryloyloxy, vinyloxy, oxirane and oxetane are preferred, and acryloyloxy is more preferred. Liquid crystal can be a thermotropic liquid crystal or a lyotropic liquid crystal. From the aspect of being able to perform dense film thickness control, a thermotropic liquid crystal is preferred. In addition, as a phase sequence structure in a thermotropic liquid crystal, it can be a nematic liquid crystal or a smectic liquid crystal. In addition, it can be a rod-shaped liquid crystal or a disc-shaped liquid crystal. The polymerizable liquid crystal compound can be used alone or in combination with two or more.

[0125] As a polymerizable liquid crystal compound, from the viewpoint of exhibiting reverse wavelength dispersion, a liquid crystal having a mesomorphic structure in a T-type or H-type which further has birefringence in a direction perpendicular to the long axis direction of the molecule is preferred. From the viewpoint of obtaining a stronger dispersion, a T-type liquid crystal is more preferred. Specifically, as the structure of the T-type liquid crystal, for example, a compound represented by the following formula (I) can be cited.

[0126] [Chemical formula 1]

[0127]

[0128] In formula (I), Ar represents a divalent aromatic group which may have a substituent. The divalent aromatic group preferably contains at least one of a nitrogen atom, an oxygen atom, and a sulfur atom. When the number of aromatic groups contained in the divalent group Ar is 2 or more, the 2 or more aromatic groups may be bonded to each other by divalent bonding groups such as a single bond, -CO-O-, or -O-.

[0129] G 1 and G 2 Each independently represents a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atoms contained in the divalent aromatic group or the divalent alicyclic hydrocarbon group may be substituted by a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, and the carbon atoms constituting the divalent aromatic group or the divalent alicyclic hydrocarbon group may be replaced by an oxygen atom, a sulfur atom or a nitrogen atom.

[0130] L 1 , L 2 , B1 and B 2 Each independently represents a single bond or a divalent linking group.

[0131] k and l each independently represent an integer from 0 to 3 and satisfy the relationship 1 ≤ k + l. Here, when 2 ≤ k + l, B 1 and B 2 and G 1 and G 2 may be the same as or different from each other.

[0132] E 1 and E 2 Each independently represents an alkanediyl group having 1 to 17 carbon atoms (in Japanese: アルカンジイル基). Here, the hydrogen atoms contained in the alkanediyl group may be substituted by halogen atoms, and the -CH2- contained in the alkanediyl group may be replaced by -O-, -S-, -COO-. When there are multiple -O-, -S-, -COO-, they are not adjacent to each other. P 1 and P 2 Independently of each other, represent a polymerizable group or a hydrogen atom, and at least one is a polymerizable group.

[0133] G 1 and G 2 Each independently is preferably a 1,4-phenylene diyl group that can be substituted by at least one substituent selected from halogen atoms and alkyl groups having 1 to 4 carbon atoms, a 1,4-cyclohexane diyl group that can be substituted by at least one substituent selected from halogen atoms and alkyl groups having 1 to 4 carbon atoms, more preferably a 1,4-phenylene diyl group substituted by a methyl group, an unsubstituted 1,4-phenylene diyl group, or an unsubstituted 1,4-trans-cyclohexane diyl group, and particularly preferably an unsubstituted 1,4-phenylene diyl group or an unsubstituted 1,4-trans-cyclohexane diyl group. In addition, it is preferred that at least one of the multiple G 1 and G 2 is a divalent alicyclic hydrocarbon group. In addition, it is more preferably that at least one of the G 1 bonded to L 2 or L 1 and G 2 is a divalent alicyclic hydrocarbon group.

[0134] L 1 and L 2 Each independently is preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a1 OR a2 -, -R a3 COOR a4 -, -R a5 OCOR a6 -, R a7 OC=OOR a8-、-N=N-、-CR c =CR d -, or -C≡C-. Here, R a1 ~R a8 Each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms, and R c and R d represents an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. 1 and L 2 Each independently is more preferably a single bond, -OR a2-1 -、-CH2-、-CH2CH2-、-COOR a4-1 -, or OCOR a6-1 -. Here, R a2-1 , R a4-1 , R a6-1 Each independently represents a single bond, -CH2-, or -CH2CH2-. 1 and L 2 Each independently is further preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, or OCO-.

[0135] B 1 and B 2 Each of them is independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a9 OR a10 -、-R a11 COOR a12 -、-R a13 OCOR a14 -, or R a15 OC=OOR a16 -. Here, R a9 ~R a16 Each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms. 1 and B 2 Each independently is more preferably a single bond, -OR a10-1 -、-CH2-、-CH2CH2-、-COOR a12 -1 -, or OCOR a14-1 -. Here, R a10-1 , R a12-1 , R a14-1 Each independently represents a single bond, -CH2-, or -CH2CH2-. 1 and B 2 Each independently is further preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, -OCO-, or OCOCH2CH2-.

[0136] From the viewpoint of exhibiting reverse wavelength dispersion, k and l are preferably in the range of 2≤k+l≤6, preferably k+l=4, and more preferably k=2 and l=2. If k=2 and l=2, a symmetrical structure is obtained, which is preferred.

[0137] 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.

[0138] As P 1 or P 2 The polymerizable group shown in the figure includes epoxy, vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, oxiranyl and oxetanyl, etc. Among them, acryloyloxy, methacryloyloxy, vinyloxy, oxiranyl and oxetanyl are preferred, and acryloyloxy is more preferred.

[0139] Ar preferably has at least one selected from an aromatic hydrocarbon ring that may have a substituent, an aromatic heterocycle that may have a substituent, and an electron-withdrawing group. As the aromatic hydrocarbon ring, for example, benzene ring, naphthalene ring, anthracene ring, etc. can be cited, preferably benzene ring, naphthalene ring. As the aromatic heterocycle, furan ring, benzofuran ring, pyrrole ring, indole ring, thiophene ring, benzothiophene ring, pyridine ring, pyrazine ring, pyrimidine ring, triazole ring, triazine ring, pyrroline ring, imidazole ring, pyrazole ring, thiazole ring, benzothiazole ring, thienothiazole ring, oxazole ring, benzoxazole ring and phenanthroline ring etc. can be cited. Among them, preferably have thiazole ring, benzothiazole ring or benzofuran ring, further preferably have benzothiazolyl. In addition, when Ar includes nitrogen atom, the nitrogen atom preferably has π electrons.

[0140] 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, further preferably 14 or more, and particularly preferably 16 or more. It is preferably 30 or less, more preferably 26 or less, and further preferably 24 or less.

[0141] As the aromatic group represented by Ar, for example, the following groups can be preferably mentioned.

[0142] [Chemical formula 2]

[0143]

[0144] In the formulas (Ar-1) to (Ar-23), the * symbol represents a connecting portion, and Z 0 , Z 1 and Z 2Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, an alkylsulfonyl group having 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, an N-alkylamino group having 1 to 12 carbon atoms, an N,N-dialkylamino group having 2 to 12 carbon atoms, an N-alkylsulfamoyl group having 1 to 12 carbon atoms, or an N,N-dialkylsulfamoyl group having 2 to 12 carbon atoms.

[0145] Q 1 , Q 2 and Q 3 Each independently represents -CR 2’ R 3’ -、-S-、-NH-、-NR 2’ -, -CO- or O-, R 2’ and R 3’ Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0146] J 1 and J 2 Each independently represents a carbon atom or a nitrogen atom.

[0147] Y 1 , Y 2 and Y 3 Each independently represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may be substituted.

[0148] W 1 and W 2 Each independently represents a hydrogen atom, a cyano group, a methyl group or a halogen atom, and m represents an integer of 0-6.

[0149] As Y 1 , Y 2 and Y 3 The aromatic hydrocarbon group in the group includes aromatic hydrocarbon groups having 6 to 20 carbon atoms, such as phenyl, naphthyl, anthracenyl, phenanthrenyl, and biphenyl, preferably phenyl and naphthyl, and more preferably phenyl. The aromatic heterocyclic group includes aromatic heterocyclic groups having 4 to 20 carbon atoms, such as furanyl, pyrrolyl, thienyl, pyridyl, thiazolyl, and benzothiazolyl, which contain at least one hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom, preferably furanyl, thienyl, pyridyl, thiazolyl, and benzothiazolyl.

[0150] Y 1 , Y 2 and Y 3Each independently may be a polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group which may be substituted. The polycyclic aromatic hydrocarbon group refers to a condensed polycyclic aromatic hydrocarbon group or a group derived from a collection of aromatic rings. The polycyclic aromatic heterocyclic group refers to a condensed polycyclic aromatic heterocyclic group or a group derived from a collection of aromatic rings.

[0151] Z 0 , Z 1 and Z 2 Each of Z is independently preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms. 0 More preferably, a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group. 1 and Z 2 More preferred are a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group and a cyano group.

[0152] Q 1 , Q 2 and Q 3 Preferred are -NH-, -S-, -NR 2’ -、-O-,R 2’ A hydrogen atom is preferred, and -S-, -O-, and -NH- are particularly preferred.

[0153] Among formulae (Ar-1) to (Ar-23), formulae (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability.

[0154] In the formulas (Ar-16) to (Ar-23), Y 1 The nitrogen atom and Z 0 Together, they form an aromatic heterocyclic group. Examples of the aromatic heterocyclic group include the aromatic heterocyclic groups described above as aromatic heterocyclic rings that Ar may have, such as a pyrrole ring, an imidazole ring, a pyrroline ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, an indole ring, a quinoline ring, an isoquinoline ring, a purine ring, and a pyrrolidine ring. The aromatic heterocyclic group may have a substituent. In addition, Y 1 The nitrogen atom and Z 0 Together, they are the above-mentioned optionally substituted polycyclic aromatic hydrocarbon groups or polycyclic aromatic heterocyclic groups, for example, benzofuran ring, benzothiazole ring, benzoxazole ring, etc.

[0155] Among the polymerizable liquid crystal compounds, compounds with a maximum absorption wavelength of 300 to 400 nm are preferred. When a photopolymerization initiator is included in the polymerizable liquid crystal composition, it is possible to carry out polymerization reaction and gelation of the polymerizable liquid crystal compound during long-term storage. However, if the maximum absorption wavelength of the polymerizable liquid crystal compound is 300 to 400 nm, even if it is exposed to ultraviolet light during storage, the generation of reactive species from the photopolymerization initiator and the polymerization reaction and gelation of the polymerizable liquid crystal compound caused by the reactive species can be effectively suppressed. Therefore, it becomes advantageous in terms of the long-term stability of the polymerizable liquid crystal composition, and the orientation and uniformity of the film thickness of the obtained phase difference film can be improved. It should be noted that the maximum absorption wavelength of the polymerizable liquid crystal compound can be measured in a solvent using an ultraviolet-visible spectrophotometer. The solvent is a solvent that can dissolve the polymerizable liquid crystal compound, and chloroform and the like can be cited as examples.

[0156] Examples of the disc-shaped polymerizable liquid crystal compound include a compound containing a group represented by formula (W) (hereinafter, also referred to as a “polymerizable liquid crystal compound (W)”).

[0157] [Chemical formula 3]

[0158]

[0159] [In formula (W), R 40 It represents the following formulas (W-1) to (W-5).]

[0160] [Chemical formula 4]

[0161]

[0162] [In formulas (W-1) to (W-5),

[0163] X 40 and Z 40 Each independently represents an alkanediyl group having 1 to 12 carbon atoms, wherein the hydrogen atoms contained in the alkanediyl group may be substituted by an alkoxy group having 1 to 5 carbon atoms, wherein the hydrogen atoms contained in the alkoxy group may be substituted by a halogen atom. In addition, -CH2- constituting the alkanediyl group may be substituted by -O- or -CO-.

[0164] m2 represents an integer.]

[0165] Examples of the rod-shaped polymerizable liquid crystal compound include compounds represented by formula (II), formula (III), formula (IV), formula (V), formula (VI), or formula (VII).

[0166] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (II)

[0167] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11(III)

[0168] P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12(IV)

[0169] P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (V)

[0170] P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (VI)

[0171] P11-B11-E11-B12-A11-B13-A12-F11 (VII)

[0172] [In formulas (II) to (VII),

[0173] A11 to A14 each independently represent a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atoms contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group or a nitro group, and the hydrogen atoms contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom.

[0174] B11 and B17 each independently represent -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR 16 -、-NR 16 -CO-, -CO-, -CS- or a single bond. 16 It represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0175] B12 to B16 each independently represent -C≡C-, -CH=CH-, -CH2-CH2-, -O-, -S-, -C(=O)-, -C(=O)-O-, -OC(=O)-, -OC(=O)-O-, -CH=N-, -N=CH-, -N=N-, -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.

[0176] E11 and E12 each independently represent an alkanediyl group having 1 to 12 carbon atoms, wherein the hydrogen atoms contained in the alkanediyl group may be substituted by an alkoxy group having 1 to 5 carbon atoms, wherein the hydrogen atoms contained in the alkoxy group may be substituted by a halogen atom, and wherein -CH2- constituting the alkanediyl group may be substituted by -O- or -CO-.

[0177] F11 represents a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxyl group, a hydroxymethyl group, a formyl group, a sulfo group (-SO3H), a carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and the -CH2- constituting the alkyl group and the alkoxy group may be replaced by -O-.

[0178] P11 and P12 each independently represent a polymerizable group.]

[0179] Relative to 100 parts by mass of the solid content of the phase difference film forming composition, the content of the polymerizable liquid crystal compound in the phase difference film 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 further preferably 90 to 95 parts by mass. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the perspective of the orientation of the obtained phase difference film. It should be noted that in this specification, the solid content of the polymerizable liquid crystal composition refers to all components after removing volatile components such as organic solvents from the polymerizable liquid crystal composition.

[0180] (5-2) Phase difference film forming composition

[0181] As described above, the retardation film forming composition contains a polymerizable liquid crystal compound. The retardation film forming composition may further contain reactive additives such as a solvent, a leveling agent, a polymerization initiator, a photosensitizer, a polymerization inhibitor, a crosslinking agent, and an adhesion agent. From the viewpoint of processability, it preferably contains a solvent and a leveling agent.

[0182] The phase difference film forming composition may contain a solvent. Generally, the viscosity of the polymerizable liquid crystal compound is high, so by making it into a phase difference film forming composition dissolved in a solvent, coating becomes easy, and as a result, the formation of the phase difference film becomes easy in many cases. As a solvent, a solvent that can completely dissolve the polymerizable liquid crystal compound is preferably a solvent that is inactive to the polymerization reaction of the polymerizable liquid crystal compound.

[0183] Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, 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; chlorinated solvents such as chloroform and chlorobenzene; amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone, etc. These solvents may be used alone or in combination of two or more.

[0184] The content of the solvent is preferably 50 to 98% by mass relative to the total amount of the phase difference film forming composition. In other words, the content of the solid component in the phase difference film forming composition is preferably 2 to 50% by mass, and more preferably 5 to 30% by mass. If the content of the solid component is less than 50% by mass, the viscosity of the phase difference film forming composition becomes low, so the thickness of the phase difference film becomes roughly uniform, so that the phase difference film is not easy to produce uneven trends. In addition, the content of the above-mentioned solid component can be determined by considering the thickness of the phase difference film to be manufactured.

[0185] The composition for forming a phase difference film may contain a leveling agent. The leveling agent refers to an additive having the function of adjusting the fluidity of the composition and making the film obtained by coating the composition flatter, and examples thereof include organic modified silicone-based, polyacrylate-based, and perfluoroalkyl-based leveling agents. Among them, in the case of horizontal orientation, polyacrylate-based leveling agents and perfluoroalkyl-based leveling agents are preferred, and in the case of vertical orientation, organic modified silicone-based leveling agents and perfluoroalkyl-based leveling agents are preferred.

[0186] When the composition for forming a phase difference film contains a leveling agent, its content is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass relative to 100 parts by mass of the content of the polymerizable liquid crystal compound. If the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal compound, and there is a tendency for the obtained phase difference film to become smoother. If the content of the leveling agent exceeds the above range relative to the polymerizable liquid crystal compound, there is a tendency for the obtained phase difference film to be prone to unevenness. It should be noted that the composition for forming a phase difference film may contain two or more leveling agents.

[0187] The phase difference film forming composition may contain a polymerization initiator. A polymerization initiator is a compound that can initiate a polymerization reaction of a polymerizable liquid crystal compound or the like. As the polymerization initiator, a photopolymerization initiator that generates active free radicals by the action of light is preferred from the viewpoint of being independent of the phase state of the thermotropic liquid crystal.

[0188] As long as the photopolymerization initiator is a compound capable of initiating a polymerization reaction of a polymerizable liquid crystal compound, a known photopolymerization initiator can be used. Specifically, a photopolymerization initiator capable of generating active free radicals or acids by the action of light can be cited, among which a photopolymerization initiator generating free radicals by the action of light is preferred. The photopolymerization initiator can be used alone or in combination of two or more.

[0189] As the photopolymerization initiator, a known photopolymerization initiator can be used. For example, as a photopolymerization initiator that generates active free radicals, self-cleaving benzoin compounds, acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, oxime ester compounds, acylphosphine oxide compounds, azo compounds, etc. can be used, and hydrogen-abstracting benzophenone compounds, alkylphenone compounds, benzoin ether compounds, benzyl ketal compounds, dibenzosuberone compounds, anthraquinone compounds, xanthone compounds, thioxanthone compounds, halogenated acetophenone compounds, dialkoxyacetophenone compounds, halogenated bisimidazole compounds, halogenated triazine compounds, triazine compounds, etc. can be used. As a photopolymerization initiator that generates an acid, iodonium salts and sulfonium salts can be used. From the viewpoint of excellent reaction efficiency at low temperature, self-cleavage type photopolymerization initiators are preferred, and acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, and oxime ester compounds are particularly preferred.

[0190] The content of the polymerization initiator in the phase difference film forming composition can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal compound, and is generally 0.1 to 30 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal compound. If the content of the polymerization initiator is within the above range, polymerization can be performed without disturbing the orientation of the polymerizable liquid crystal compound.

[0191] The phase difference film forming composition may contain a sensitizer. As the sensitizer, a photosensitizer is preferred. As the sensitizer, for example, xanthone compounds such as xanthone and thioxanthone (for example, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene compounds such as anthracene and anthracene containing an alkoxy group (for example, dibutoxyanthracene, etc.); phenothiazine and rubrene, etc. can be cited.

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

[0193] The retardation film forming composition may contain an antioxidant from the viewpoint of stably carrying out the polymerization reaction. The antioxidant can control the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound.

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

[0195] When the phase difference film forming composition contains an antioxidant, the content of the antioxidant is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and further preferably 0.5 to 8 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal compound. The antioxidant may be used alone or in combination of two or more. If the content of the antioxidant is within the above range, polymerization can be performed without disturbing the orientation of the polymerizable liquid crystal compound.

[0196] The phase difference film forming composition may contain a reactive additive. As a reactive additive, it is preferred to have a carbon-carbon unsaturated bond, an active hydrogen reactive group, and a mercapto group in its molecule. It should be noted that the "active hydrogen reactive group" referred to herein refers to a group reactive to a group having active hydrogen such as a carboxyl group (-COOH), a hydroxyl group (-OH), and an amino group (-NH2), and glycidyl, oxazoline, carbodiimide, aziridine, imide, isocyanate, thioisocyanate, maleic anhydride, etc. are representative examples thereof. The number of reactive groups possessed by the reactive additive is usually 1 to 20, respectively, and preferably 1 to 10, respectively.

[0197] (5-3) Base material

[0198] As the above-mentioned substrate for forming the phase difference film, a glass substrate and a film substrate can be cited, preferably a film substrate, and from the aspect of being able to be manufactured continuously, a long roll film is more preferred. As the resin constituting the film substrate, for example, chain polyolefins such as polyethylene and polypropylene; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate; polyacrylate; cellulose esters such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyether sulfone; polyether ketone; polyphenylene sulfide and polyphenylene ether, etc. Among them, from the viewpoint of transparency when used in optical film applications, a film substrate selected from any one of triacetyl cellulose, cyclic olefin resins, polymethacrylate, and polyethylene terephthalate is more preferred.

[0199] Examples of commercially available cellulose ester substrates include "FUJITAC Film" (manufactured by Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (manufactured by Konica Minolta Opto Co., Ltd.). Examples of commercially available cyclic olefin resins include "Topas" (registered trademark) (manufactured by Ticona (Germany)), "ARTON" (registered trademark) (manufactured by JSR Corporation), "ZEONOR" (registered trademark), "ZEONEX" (registered trademark) (manufactured by ZEON Corporation of Japan) and "APEL" (registered trademark) (manufactured by Mitsui Chemicals, Inc.). Such cyclic olefin resins can be made into films by known methods such as solvent casting and melt extrusion to form substrates. Commercially available cyclic olefin resin substrates can also be used. Examples of commercially available cyclic olefin resin substrates include "ESCENA" (registered trademark), "SCA40" (registered trademark) (all manufactured by Sekisui Chemical Co., Ltd.), "Zeonor Film" (registered trademark) (manufactured by OPTEX Corporation), and "Arton Film" (registered trademark) (manufactured by JSR Corporation).

[0200] The thickness of the substrate is preferably thin enough to be handled practically, but if it is too thin, there is a tendency for reduced strength and poor processability. The thickness of the substrate is usually 5 μm to 300 μm, preferably 10 μm to 200 μm, and more preferably 10 to 50 μm. In addition, by peeling off the substrate and transferring the phase difference film, a further thin film effect can be obtained.

[0201] (5-4) Oriented Film

[0202] In this specification, the alignment film has an alignment regulating force for orienting the polymerizable liquid crystal compound in a desired direction.

[0203] The orientation film makes it easy to orient the liquid crystal of the polymerizable liquid crystal compound. The state of liquid crystal orientation such as horizontal orientation, vertical orientation, mixed orientation, and tilted orientation varies according to the properties of the orientation film and the polymerizable liquid crystal compound, and the combination thereof can be selected arbitrarily. For example, if the orientation film is a material that exhibits horizontal orientation as an orientation limiting force, the polymerizable liquid crystal compound can form a horizontal orientation or a mixed orientation, and if it is a material that exhibits a vertical orientation, the polymerizable liquid crystal compound can form a vertical orientation or a tilted orientation. Expressions such as horizontal and vertical indicate the direction of the optical axis of the oriented polymerizable liquid crystal compound when the plane of the phase difference film is used as a reference. For example, vertical orientation refers to the optical axis of the polymerizable liquid crystal compound having an orientation in a direction perpendicular to the plane of the phase difference film. The vertical mentioned here refers to 90°±20° relative to the plane of the phase difference film.

[0204] Regarding the orientation restraining force, when the orientation film is formed of an orientation polymer, it can be arbitrarily adjusted according to the surface state and friction conditions, and when it is formed of a photo-orientation polymer, it can be arbitrarily adjusted according to polarized light irradiation conditions, etc. In addition, the liquid crystal orientation can also be controlled by selecting the surface tension, liquid crystal properties, etc. of the polymerizable liquid crystal compound.

[0205] As an oriented film formed between a substrate and a phase difference film, it is preferred that the oriented film is insoluble in the solvent used when forming the phase difference film on the oriented film and has heat resistance in the heating treatment for removing the solvent and aligning the liquid crystal. As the oriented film, an oriented film comprising an oriented polymer, a photo-oriented film and a groove oriented film, a stretched film stretched along the orientation direction, etc. can be cited. In the case of being applied to a long roll film, a photo-oriented film is preferred from the aspect of being able to easily control the orientation direction.

[0206] The thickness of the alignment film is usually in the range of 10 nm to 5000 nm, preferably in the range of 10 nm to 1000 nm, and more preferably in the range of 30 to 300 nm.

[0207] As the oriented polymer used in the rubbing oriented film, polyamides, gelatins, polyimides and hydrolyzates thereof having amide bonds in the molecule, i.e., polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinyl pyrrolidone, polyacrylic acid and polyacrylates etc. can be cited. Among them, polyvinyl alcohol is preferred. These oriented polymers can be used alone or in combination of two or more.

[0208] As a method of rubbing, there is mentioned a method of bringing a film of an oriented polymer formed on the surface of a substrate by applying an oriented polymer composition to the substrate and annealing the film into contact with a rubbing roller wound with a rubbing cloth and rotating.

[0209] The photo-alignment film is composed of a polymer, oligomer or monomer having a photoreactive group. The photo-alignment film obtains an alignment restraining force by irradiating polarized light. From the perspective of being able to arbitrarily control the direction of the alignment restraining force by selecting the polarization direction of the irradiated polarized light, a photo-alignment film is more preferred.

[0210] A photoreactive group refers to a group that generates liquid crystal orientation capability by irradiation with light. Specifically, a photoreaction that is the origin of the liquid crystal orientation capability, such as orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction or photodecomposition reaction of molecules generated by irradiation with light, occurs. Among the photoreactive groups, from the aspect of excellent orientation, a group that undergoes dimerization reaction or photocrosslinking reaction is preferred. As a photoreactive group capable of the above-mentioned reaction, a photoreactive group having an unsaturated bond, particularly a double bond, is preferably a group having at least one selected from a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond) and a carbon-oxygen double bond (C=O bond).

[0211] As photoreactive groups having C=C bonds, for example, vinyl, polyene, stilbene, stilbazolyl, stilbazolinium, chalcone and cinnamoyl groups can be cited. From the viewpoint of easy control of reactivity and the viewpoint of orientation restriction during photo-orientation, chalcone and cinnamoyl groups are preferred. As photoreactive groups having C=N bonds, groups having structures such as aromatic Schiff bases and aromatic hydrazones can be cited. As photoreactive groups having N=N bonds, groups with azobenzene as the basic structure, such as azobenzene, azonaphthyl, aromatic heterocyclic azo, disazo and formazan, can be cited. As photoreactive groups having C=O bonds, benzophenone, coumarin, anthraquinone and maleimide groups can be cited. These groups can have substituents such as alkyl, alkoxy, aryl, allyloxy, cyano, alkoxycarbonyl, hydroxyl, sulfonic acid and halogenated alkyl.

[0212] In order to irradiate polarized light, it can be a form of directly irradiating polarized light from the film surface, or it can be a form of irradiating polarized light from the substrate side and transmitting the polarized light. In addition, the polarized light is particularly preferably substantially parallel light. The wavelength of the irradiated polarized light is preferably a wavelength in the wavelength region where the photoreactive group of the polymer or monomer with a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) in the range of 250 to 400nm is particularly preferred. As the light source used in the polarized light irradiation, xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, ultraviolet lasers such as KrF and ArF can be cited, and high-pressure mercury lamps, ultra-high-pressure mercury lamps and metal halide lamps are more preferred. These lamps are preferred because the luminous intensity of ultraviolet light with a wavelength of 313nm is large. The light from the above-mentioned light source is irradiated through an appropriate polarizer, thereby irradiating polarized light. As the polarizer, polarizing prisms such as polarizing filters, Glan Thompson prisms, and Glan Taylor prisms, and wire grid polarizers can be used.

[0213] (6) Adhesive layer

[0214] The optical laminate 1 of the present embodiment includes three types of adhesive layers (the adhesive layer inside the linear polarizing plate, the adhesive layer 3 between the linear polarizing plate and the phase element, and the adhesive layer 42 inside the phase element).

[0215] Adhesive layer in linear polarizing plate ( Figure 1 ) is a component of the linear polarizing plate 2, and is a layer provided as needed for laminating the first protective film 21 and the polarizer 22, and for laminating the polarizer 22 and the second protective film 23. The optical laminate preferably includes the linear polarizing plate intra-adhesive layer. The linear polarizing plate-phase element inter-adhesive layer 3 is a layer provided for laminating the linear polarizing plate 2 and the phase element 4. The optical laminate preferably includes the linear polarizing plate-phase element inter-adhesive layer 3. The phase element intra-adhesive layer 42 is a layer used to laminate the first phase difference layer 41 (e.g., λ / 4 phase difference layer) and the second phase difference layer 43 (e.g., positive C plate) in the phase element 4.

[0216] The adhesive layer in the linear polarizing plate, the adhesive layer 3 between the linear polarizing plate and the phase element, and the adhesive layer 42 in the phase element can all be adhesive layers or adhesive layers. The adhesive layer is a layer formed by an adhesive composition (pressure-sensitive adhesive composition), and the adhesive layer is a layer formed by an adhesive composition. The adhesive layer in the linear polarizing plate and the adhesive layer 42 in the phase element are preferably adhesive layers. In particular, from the viewpoint of suppressing the movement of the antistatic agent described later, the moisture permeability of the adhesive layer 42 in the phase element is preferably low, and therefore it is preferably formed by an active energy ray-curing adhesive. In addition, in order to suppress the cracks of the phase element, an adhesive layer with a higher elastic modulus than the adhesive layer is preferred. On the other hand, the adhesive layer 3 between the linear polarizing plate and the phase element is preferably an adhesive layer.

[0217] (6-1) Adhesive layer

[0218] As the adhesive composition forming the adhesive layer, for example, there can be mentioned a water-based adhesive composition, a curable adhesive composition cured by heating or irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays, etc. As the water-based adhesive composition, for example, there can be mentioned a composition obtained by dissolving a polyvinyl alcohol-based resin or a carbamate resin as a main component in water, and a composition obtained by dispersing a polyvinyl alcohol-based resin or a carbamate resin as a main component in water. The water-based adhesive composition may further contain curable components such as polyaldehydes, melamine-based compounds, zirconium oxide compounds, zinc compounds, glyoxal compounds, and water-soluble epoxy resins, and crosslinking agents. Examples of the water-based adhesive composition include the adhesive composition described in JP-A-2010-191389, the adhesive composition described in JP-A-2011-107686, the composition described in JP-A-2020-172088, and the composition described in JP-A-2005-208456.

[0219] The curable adhesive composition is preferably an active energy ray-curable adhesive composition that contains a curable (polymerizable) compound as a main component and is cured by irradiation with active energy rays. Examples of the active energy ray-curable adhesive composition include a cationic polymerizable adhesive composition containing a cationic polymerizable compound as a curable compound, a free radical polymerizable adhesive composition containing a free radical polymerizable compound as a curable compound, and a mixed adhesive composition containing both a cationic polymerizable compound and a free radical polymerizable compound as curable compounds.

[0220] Cationic polymerizable compounds are compounds or oligomers that are cured by cation polymerization reaction by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays, or by heating, and specifically include epoxy compounds, oxetane compounds, and vinyl compounds. Examples of epoxy compounds include alicyclic epoxy compounds (compounds having one or more epoxy groups bonded to an alicyclic ring in the molecule) such as 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate; aromatic epoxy compounds (compounds having an aromatic ring and an epoxy group in the molecule) such as diglycidyl ether of bisphenol A; and aliphatic epoxy compounds (compounds having at least one oxirane ring bonded to an aliphatic carbon atom in the molecule) such as 2-ethylhexyl glycidyl ether and 1,4-butanediol diglycidyl ether.

[0221] Examples of the oxetane compound include compounds having one or more oxetane rings in the molecule, such as 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane.

[0222] The cationic polymerization adhesive composition preferably contains a cationic polymerization initiator. The cationic polymerization initiator may be a thermal cationic polymerization initiator or a photocationic polymerization initiator. As the cationic polymerization initiator, aromatic diazonium salts such as benzene diazonium hexafluoroantimonate; aromatic iodonium salts such as diphenyl iodonium tetrakis (pentafluorophenyl) borate; aromatic sulfonium salts such as triphenyl sulfonium hexafluorophosphate; iron-arene complexes such as ditoluene-cyclopentadienyl iron (II) hexafluoroantimonate, etc. The content of the cationic polymerization initiator is generally 0.1 to 10 parts by mass relative to 100 parts by mass of the cationic polymerization compound. Two or more cationic polymerization initiators may be included.

[0223] Examples of the cationically polymerizable adhesive composition include cationically polymerizable compositions described in JP-A Nos. 2016-126345 and 2021-113969.

[0224] The free radical polymerizable compound is a compound or oligomer that is cured by free radical polymerization reaction by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays, or heating, and specifically, a compound having an ethylenically unsaturated bond can be cited. As the compound having an ethylenically unsaturated bond, a (meth)acrylic compound having one or more (meth)acryloyl groups in the molecule, a vinyl compound having one or more vinyl groups in the molecule, etc. can be cited.

[0225] Examples of the (meth)acrylic compound include (meth)acrylic group-containing compounds such as (meth)acrylic oligomers having at least two (meth)acrylic groups in a molecule obtained by reacting two or more (meth)acrylic acid ester monomers, (meth)acrylamide monomers and functional group-containing compounds having at least one (meth)acryloyloxy group in a molecule.

[0226] 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. As the radical polymerization initiator, acetophenone-based initiators such as acetophenone and 3-methylacetophenone; benzophenone-based initiators such as benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone; benzoin ether-based initiators such as benzoin propyl ether and benzoin ethyl ether; thioxanthone-based initiators such as 4-isopropylthioxanthone; xanthone, fluorenone, etc. The content of the radical polymerization initiator is generally 0.1 to 10 parts by mass relative to 100 parts by mass of the radical polymerizable compound. Two or more radical polymerization initiators may be included.

[0227] Examples of the radical polymerizable adhesive composition include radical polymerizable compositions described in JP-A-2016-126345, JP-A-2016-153474, and International Publication No. 2017 / 183335.

[0228] The active energy ray-curable adhesive composition may 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 as necessary.

[0229] The bonding of two layers using an adhesive layer can be carried out as follows: an adhesive composition is applied on at least one bonding surface selected from each of the two layers, the two layers are overlapped via the coating layer of the adhesive composition, and after being bonded together by pressing from top and bottom using a bonding roller, the adhesive layer is dried, irradiated with active energy rays to cure it, or heated to cure it.

[0230] Before forming the coating layer of the adhesive layer, at least one of the bonding surfaces of the two layers may be subjected to an easy-adhesion treatment such as saponification treatment, corona treatment, plasma treatment, primer treatment, anchor coating treatment, etc. The coating layer of the adhesive composition may be formed by various coating methods such as a die coater, a comma coater, a gravure coater, a wire bar coater, and a knife coater.

[0231] The light irradiation intensity during irradiation with active energy rays is determined according to the composition of the active energy ray-curable adhesive composition and is not particularly limited, but is preferably 10 mW / cm 2Above and 1,000mW / cm 2 It should be noted that the irradiation intensity is preferably an intensity in a wavelength region effective for the activation of a photocationic polymerization initiator or a photoradical polymerization initiator. It is preferred to irradiate once or more times with such a light irradiation intensity, and set the accumulated light amount to 10 mJ / cm 2 More preferably, 100 mJ / cm 2 Above and 1,000mJ / cm 2 the following.

[0232] The light source used for polymerizing and curing the active energy ray-curable adhesive composition is not particularly limited, and examples thereof 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.

[0233] The thickness of the adhesive layer formed by 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, and may be 0.01 μm or more, preferably 0.05 μm or more. The thickness of the adhesive layer formed by 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, and may be 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more.

[0234] (6-2) Adhesive layer

[0235] As the adhesive composition forming the adhesive layer, the adhesive composition with excellent optical transparency known in the past can be used without particular restriction, for example, an adhesive composition with base polymers such as (methyl) acrylic resin, urethane resin, silicone resin, polyvinyl ether resin can be used. In addition, active energy ray curing adhesive composition, thermosetting adhesive composition, etc. can also be used. Among them, an adhesive composition with excellent (methyl) acrylic resin as base polymer such as transparency, adhesion, re-peelability, weather resistance, heat resistance, etc. is suitable. The adhesive composition can further include a crosslinking agent, a silane compound, an antistatic agent, etc.

[0236] [(Meth)acrylic resin]

[0237] The (meth)acrylic resin contained in the adhesive composition is preferably a polymer (hereinafter also referred to as a "(meth)acrylate polymer") having a structural unit derived from a (meth)acrylic acid alkyl ester represented by the following formula (VIII) as a main component (for example, containing 50 parts by mass or more relative to 100 parts by mass of the structural unit of the (meth)acrylic resin).

[0238] [Chemical formula 5]

[0239]

[0240] [In formula (VIII), R 10 represents a hydrogen atom or a methyl group, R 20 It represents an alkyl group having 1 to 20 carbon atoms, the alkyl group may have any structure of linear, branched or cyclic, and the hydrogen atoms of the alkyl group may be substituted by an alkoxy group having 1 to 10 carbon atoms.]

[0241] Examples of the (meth)acrylate represented by formula (VIII) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, stearyl (meth)acrylate, and tert-butyl (meth)acrylate. As the specific example of alkyl acrylate containing alkoxy, (methyl) 2-methoxyethyl acrylate, (methyl) ethoxymethyl acrylate, (methyl) 2-methoxy-2-ethoxyethyl acrylate, etc. can be cited. In particular, based on the total amount of structural units constituting (methyl) acrylic resin (VIII), it is preferred to include 10% by mass and 40% by mass acrylate containing alkoxy, preferably 15% by mass and 40% by mass, more preferably 15% by mass and 35% by mass, particularly preferably 20% by mass and 35% by mass. In the case where the content is less than 10% by mass, the ionic conductivity of the adhesive is low, so in order to ensure the desired antistatic property, it is necessary to add a large amount of antistatic agent, and the metal corrosion resistance becomes low. If it exceeds 40% by mass, the polarity of the adhesive becomes high, so that the moisture content becomes high, which affects the adhesive properties. Among them, as alkyl acrylate, it is preferred to include n-butyl (methyl) acrylate or 2-ethylhexyl (methyl) acrylate, and it is particularly preferred to include n-butyl (methyl) acrylate. In addition, as the alkoxy group-containing acrylate, 2-methoxyethyl acrylate is preferably included.

[0242] The (meth)acrylate polymer may contain structural units derived from other monomers in addition to the structural unit (VIII). The structural units derived from other monomers may be one type or two or more types. Examples of other monomers that the (meth)acrylate polymer may contain include monomers having polar functional groups, monomers having aromatic groups, and (meth)acrylamide monomers.

[0243] Examples of the monomer having a polar functional group include (meth)acrylates having a polar functional group. Examples of the polar functional group include hydroxyl groups, carboxyl groups, substituted or unsubstituted amino groups substituted with an alkyl group having 1 to 6 carbon atoms, and heterocyclic groups such as epoxy groups.

[0244] The content of the structural unit derived from the monomer having a polar functional group in the (meth)acrylate 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, further preferably 0.5 parts by mass or more and 5 parts by mass or less, particularly preferably 1 part by mass or more and 5 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylate polymer.

[0245] As monomers having aromatic groups, there can be mentioned (meth)acrylates having one (meth)acryloyl group and one or more aromatic rings (e.g., benzene ring, naphthalene ring, etc.) in the molecule and having a phenyl group, a phenoxyethyl group or a benzyl group. By including these structural units, the white spot phenomenon of the polarizing plate generated in a high temperature and high humidity environment can be suppressed.

[0246] The content of the structural unit derived from the monomer having an aromatic group in the (meth)acrylate 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 further preferably 4 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylate polymer.

[0247] Examples of (meth)acrylamide monomers include N-(methoxymethyl) (meth)acrylamide, N-(ethoxymethyl) (meth)acrylamide, N-(propoxymethyl) (meth)acrylamide, N-(butoxymethyl) (meth)acrylamide, and N-(2-methylpropoxymethyl) (meth)acrylamide. By including these structural units, the bleeding of additives such as antistatic agents described later can be suppressed.

[0248] In addition, structural units derived from other monomers other than structural unit (VIII) may include structural units derived from styrene-based monomers, structural units derived from vinyl-based monomers, and structural units derived from monomers having a plurality of (meth)acryloyl groups in the molecule.

[0249] The weight average molecular weight (hereinafter, also referred to as "Mw") of the (meth)acrylic resin is preferably 500,000 to 2.5 million. If the weight average molecular weight is 500,000 or more, the durability of the adhesive layer in a high temperature and high humidity environment can be improved. If the weight average molecular weight is 2.5 million or less, the operability when applying a coating liquid containing an adhesive composition becomes good. In this specification, "weight average molecular weight" and "number average molecular weight" are polystyrene conversion values ​​measured by gel permeation chromatography (GPC).

[0250] When the (meth)acrylic resin is dissolved in ethyl acetate to prepare a solution having a concentration of 20% by mass, the viscosity at 25°C is preferably 20 Pa·s or less, more preferably 0.1 to 15 Pa·s. If the viscosity at 25°C of the (meth)acrylic resin is within the above range, the generation of streaks when preparing an adhesive layer formed of the resin can be suppressed. The above viscosity can be measured by a Brookfield viscometer.

[0251] The glass transition temperature (Tg) of the (meth)acrylic resin is preferably in the range of -10 to -60°C, more preferably in the range of -20 to -50°C, and further preferably in the range of -30 to -45°C. The glass transition temperature can be measured by a differential scanning calorimeter (DSC).

[0252] The (meth)acrylic resin may include two or more (meth)acrylate polymers. Examples of such (meth)acrylate polymers include (meth)acrylate polymers having a weight average molecular weight smaller than that of the above-mentioned (meth)acrylate polymers having a weight average molecular weight of 500,000 to 2,500,000, and more specifically, (meth)acrylate polymers having a relatively low molecular weight and a weight average molecular weight of 50,000 to 300,000, which are mainly composed of structural units (VIII) derived from (meth)acrylate.

[0253] (Meth) acrylic resins can be generally 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 generally carried out in the presence of a polymerization initiator. The amount of the polymerization initiator used is generally 0.001 to 5 parts by mass relative to a total of 100 parts by mass of all monomers constituting the (meth) acrylic resin. (Meth) acrylic resins can also be produced by a method of polymerization using active energy rays such as ultraviolet rays.

[0254] [Crosslinking agent]

[0255] The adhesive composition preferably contains a crosslinking agent. As the crosslinking agent, conventional crosslinking agents (such as isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, etc.) can be cited, and isocyanate compounds are preferred from the viewpoints of the pot life of the adhesive composition, the crosslinking speed, and the durability of the optical laminate.

[0256] Isocyanate compounds are compounds having at least two isocyanate groups (-NCO) in the molecule. Specifically, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc. can be cited. In addition, adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, dimers and trimers of these isocyanate compounds can also be cited. Two or more isocyanate compounds can be combined.

[0257] The ratio of the crosslinking agent to 100 parts by mass of the (meth)acrylic resin is, for example, 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, further preferably 0.1 to 1 part by mass.

[0258] [Silane compounds]

[0259] The adhesive composition may further contain a silane compound.

[0260] Examples of the silane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

[0261] In addition, the silane compound may contain an oligomer derived from the above-mentioned silane compound.

[0262] The content of the silane compound in the adhesive composition is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, and more preferably 0.1 to 1 part by mass, relative to 100 parts by mass of the (meth) acrylic resin. If the content of the silane compound is 0.01 parts by mass or more, there is a tendency to improve the adhesion between the adhesive layer and the adherend, and if the content is 10 parts by mass or less, there is a tendency to suppress the oozing of the silane compound from the adhesive layer.

[0263] [Antistatic Agent]

[0264] The pressure-sensitive adhesive layer may contain an antistatic agent. As the antistatic agent, the antistatic agents described in "(7) Pressure-sensitive adhesive layer" described later can be used.

[0265] [other]

[0266] The adhesive composition may contain additives such as a single or more ultraviolet light absorber, a solvent, a crosslinking catalyst, a tackifying resin (tackifier), a plasticizer, etc. In addition, it is also useful to add an ultraviolet curable compound to the adhesive composition, form an adhesive layer, and cure it by irradiating ultraviolet light to make a harder adhesive layer.

[0267] The adhesive layer can be formed, for example, by dissolving or dispersing the adhesive composition in a solvent to prepare an adhesive composition containing a solvent, applying the solvent to the surface of a substrate or a layer to be provided with the adhesive layer, and drying the composition.

[0268] The thickness of the adhesive layer is usually 0.1 to 30 μm, preferably 3 to 30 μm, and more preferably 5 to 25 μm.

[0269] (7) Adhesive layer

[0270] The optical laminate 1 includes a pressure-sensitive adhesive layer 5 laminated on the side of the phase element 4 opposite to the linear polarizing plate 2. The basic structure of the pressure-sensitive adhesive layer 5 is the same as that of "(6-2) Pressure-sensitive adhesive layer". Here, the antistatic agent and thickness are described.

[0271] [Antistatic Agent]

[0272] The adhesive composition forming the adhesive layer 5 contains an antistatic agent. The antistatic agent includes an ionic compound including an organic cation and an anion represented by the following formula (1).

[0273] (C n F 2n+1 SO2)2N - …(1)

[0274] (In the formula, n is an integer from 0 to 5.)

[0275] Examples of the anion represented by the formula (1) include a bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N] wherein n is 1. - ], bis(fluorosulfonyl)imide anion with n=0 [(FSO2)2N - ] anion.

[0276] Examples of the organic cation include ammonium cations such as tributylmethylammonium cation, trioctylmethylammonium cation, trimethylpropylammonium cation, tetrabutylammonium cation, and (2-hydroxyethyl)trimethylammonium cation; phosphonium cations such as tributyldodecylphosphonium cation; pyridinium cations such as 1-hexylpyridinium cation, 1-octylpyridinium cation, 4-methyl-1-hexylpyridinium cation, 4-methyl-1-octylpyridinium cation, and 4-methyl-1-butylpyridinium cation; pyrrolidinium cations such as butylmethylpyrrolidinium cation and ethylmethylpyrrolidinium cation; imidazolium cations such as 1-ethyl-3-methylimidazolium cation and 1-butyl-3-methylimidazolium cation; pyrrolidinium cations; alkylammonium cations; sulfonium cations, and the like. Among them, pyrrolidinium cations and alkylammonium cations are particularly preferred from the viewpoint of being less likely to migrate between layers of the optical laminate 1. In addition, organic cations containing nitrogen atoms are preferred, and aliphatic cations are more preferred from the viewpoint of suppressing the change in the phase difference characteristics when transferring to the phase element during durability evaluation using a compound containing an aromatic ring, and pyrrolidinium cations and alkylammonium cations are further preferred.

[0277] In view of excellent temporal stability of the antistatic performance of the adhesive composition, an ionic compound that is solid at room temperature (having a melting point of 23° C. or higher) is preferred. The molecular weight of the ionic compound is not particularly limited, but is preferably 700 or less, more preferably 500 or less, for example.

[0278] The content of the antistatic agent is, for example, 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, more preferably 0.1 to 2.5 parts by mass, and further preferably 0.1 to 1.5 parts by mass, relative to 100 parts by mass of the (meth) acrylic resin. If 0.1 parts by mass or more of the antistatic agent is contained relative to 100 parts by mass of the non-volatile components of the resin constituting the adhesive layer, the antistatic performance is improved, so it is preferred. In addition, if the amount is 10 parts by mass or less, it is possible to suppress the oozing of ionic compounds from the adhesive layer during the durability test, and it is easy to maintain durability, so it is preferred.

[0279] The thickness T3 of the adhesive layer 5 is usually 5 μm or more, preferably 10 μm or more. The thickness T3 of the adhesive layer 5 is usually 35 μm or less, preferably 30 μm or less.

[0280] <Image display device>

[0281] The image display device includes the optical layered body of the present invention and an image display element (organic EL display element, etc.). The optical layered body is arranged on the observation side of the image display element. The optical layered body can be bonded to the image display element using the adhesive layer 5.

[0282] The image display device is not particularly limited, and examples thereof include image display devices such as organic electroluminescence (organic EL) display devices, inorganic electroluminescence (inorganic EL) display devices, liquid crystal display devices, and electroluminescence display devices.

[0283] Image display devices can be used as mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic billboards, measuring instruments or measuring instruments, office equipment, medical equipment, computer equipment, and the like.

[0284] Above, suitable embodiments of the present invention have been described, but the present invention is not limited by the above embodiments. In the optical laminate 1 of the above embodiment, the outermost layer is the first protective film 21 and the adhesive layer 5, but as required, a surface protective film for protecting the surface of the first protective film 21 side may be provided, and a spacer may be provided on the adhesive layer 5 side.

[0285] Example

[0286] Hereinafter, the contents of the present invention are described in more detail by enumerating embodiments and comparative examples. It should be noted that the present invention is not limited to the following embodiments. In the following description, the parts and % representing the usage amount and content are weight references unless otherwise specified. In addition, in the following description, the numbers of "second protective film 3", "adhesive layer 1" and the like represent the types of the various second protective films, adhesive layers and the like used, and have nothing to do with the symbols in the accompanying drawings.

[0287] <Measurement and evaluation>

[0288] (1) Layer or film thickness

[0289] Unless otherwise specified, the thickness of a layer or a film is measured using a laser microscope (“LEXT” manufactured by Olympus Corporation) or a digital micrometer (“MH-15M” manufactured by Nikon Corporation).

[0290] (2) In-plane phase difference of a layer or film

[0291] The in-plane retardation values ​​[nm] of the layer or film at wavelengths of 550 nm and 450 nm were measured using a retardation measuring device (manufactured by Oji Scientific Instruments Co., Ltd., KOBRA-WPR).

[0292] (3) Moisture permeability of protective film

[0293] The moisture permeability of the second protective film was measured under the following measurement conditions.

[0294] Test item: Water vapor permeability

[0295] Test method: humidity sensor method

[0296] ·Measurement device: Lyssy L80 series water vapor permeability meter

[0297] Sample preparation method: After attaching an aluminum mask to the second protective film surface of the laminated body including the supporting substrate and the second protective film described later, the supporting substrate is peeled off, and the aluminum mask is attached to the peeled surface to prepare a measurement sample. The second protective film 8 (triacetyl cellulose film with a thickness of 20 μm) used in Comparative Example 1 has no supporting substrate, so the peeling operation of the supporting substrate is not performed.

[0298] ·Measurement conditions

[0299] Measurement temperature: 40℃

[0300] Relative humidity: 90%RH

[0301] Measurement area:

[0302] Second protective film 1 to 4: 7.1×10 -4 m 2 (Transmission area when mask is installed)

[0303] Second protective film 5: 7.9×10 -5 m 2 (Transmission area when mask is installed)

[0304] Test sample setting direction: any

[0305] (4) Water vapor permeability coefficient of phase element

[0306] The moisture permeability (in g / (m 2 ·day)), and multiply it by the thickness (unit: mm) to obtain the water vapor permeability coefficient of the phase element.

[0307] (5) Evaluation of Phase Difference Change

[0308] The change in the in-plane phase difference when the optical laminate is placed in a high temperature and humid heat environment is measured and evaluated according to the following steps. A 30mm×30mm sample with the slow axis of the phase element as the long side direction is cut from the optical laminate. The evaluation sample is bonded to alkali-free glass (manufactured by Corning, product number: EAGLE XG (registered trademark)) via the antistatic adhesive layer possessed by the sample to prepare the evaluation sample. For the evaluation sample, the in-plane phase difference at wavelengths of 550nm and 450nm is measured using a phase difference measuring device (manufactured by Oji Testing Instruments Co., Ltd., KOBRA-WPR). The obtained values ​​are used to calculate the change in the in-plane phase difference ΔRe(550) and the wavelength dispersion α (in-plane phase difference Re(450) / in-plane phase difference Re(550)). The measurement is performed using 5 evaluation samples, and the average value is calculated.

[0309] The evaluation samples were placed in an oven and subjected to a 336-hour wet heat durability test at a temperature of 60°C and a relative humidity of 90% RH. The evaluation samples were taken out of the oven and the in-plane phase difference values ​​at wavelengths of 550nm and 450nm were measured using the above-mentioned phase difference measuring device 3 hours later to determine the change in the in-plane phase difference value ΔRe(550) before and after the heat resistance test.

[0310] A: ΔRe(550) less than 0.5

[0311] B: ΔRe(550) is 0.5 or more and less than 0.7

[0312] C: ΔRe(550) is 0.7 or more

[0313] The evaluation samples were placed in an oven and subjected to a 504-hour wet heat durability test at a temperature of 60°C and a relative humidity of 90% RH. The evaluation samples were taken out of the oven and the in-plane phase difference values ​​at wavelengths of 550nm and 450nm were measured using the above-mentioned phase difference measuring device 3 hours later. The change was calculated based on the wavelength dispersion α before the heat resistance test (0 hours) and the wavelength dispersion α after the heat resistance test (504 hours). The change rate of α, i.e., Δα, was calculated according to the following formula. Among the following benchmarks, the change in wavelength dispersion α of A is smaller.

[0314] Δα(%)=(α(504 hours)-α(0 hours)) / α(0 hours)×100

[0315] A: |Δα| is less than 0.2

[0316] B: |Δα| is 0.2 or more

[0317] (6) Evaluation of metal corrosion of optical laminates

[0318] Prepare a glass substrate with a metal layer in which a metal aluminum layer and a metal titanium layer are sequentially laminated on the surface of an alkali-free glass substrate by sputtering. Next, cut the optical laminate obtained in the embodiment and the comparative example into a size of 50 mm × 50 mm, and adhere the metal titanium layer side of the glass substrate with a metal layer to the adhesive layer of the optical laminate to prepare an evaluation sample. After the evaluation sample is stored in an oven at a temperature of 85°C and a relative humidity of 85%RH for 350 hours, take the evaluation sample out of the oven. Place the evaluation sample on the backlight with the glass substrate facing downward, observe the number and size of bright spots caused by light leakage, and evaluate metal corrosion according to the following criteria.

[0319] A+: No bright spots

[0320] A: 1 to 5 bright spots of 0.1 to 0.5 mm

[0321] B+: 6 to 15 bright spots in the range of 0.1 to 0.5 mm, or 5 bright spots in the range of 0.5 to 1.0 mm

[0322] B: 6 to 15 bright spots of 0.5 to 1.0 mm

[0323] C: More than 15 bright spots are observed on the entire surface, but there are some areas without bright spots.

[0324] [Production of polarizing film]

[0325] (1) Preparation of Polarizer 1

[0326] A polyvinyl alcohol film with a thickness of 20 μm, a degree of polymerization of 2400, and a saponification degree of 99.9% or more is dry-uniaxially stretched to a stretching ratio of 4.5 times, and while maintaining the tension, is immersed in a dyeing bath at 28° C. containing 0.05 parts of iodine and 5 parts of potassium iodide per 100 parts of water for 60 seconds.

[0327] Next, the polarizer was immersed in a 64°C boric acid aqueous solution 1 containing 5.5 parts of boric acid and 15 parts of potassium iodide per 100 parts of water for 110 seconds. Next, the polarizer was immersed in a 67°C boric acid aqueous solution 2 containing 5.5 parts of boric acid and 15 parts of potassium iodide per 100 parts of water for 30 seconds. Then, the polarizer was washed with 3°C pure water and dried to obtain a polarizer 1. The boron content of the polarizer 1 measured by the above method was 4.1% by mass. The thickness of the polarizer was 8 μm.

[0328] (2) Preparation of Polarizer 2

[0329] A polyvinyl alcohol resin film (average degree of polymerization of about 2400, saponification degree of 99.9 mol% or more) with a thickness of 30 μm was longitudinally uniaxially stretched to about 5 times by dry stretching, and then immersed in pure water at a temperature of 60°C for 1 minute while maintaining the tension state, and then immersed in an aqueous solution at a temperature of 28°C with a mass ratio of iodine / potassium iodide / water of 0.05 / 5 / 100 for 60 seconds. Then, it was immersed in an aqueous solution at a temperature of 72°C with a mass ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100 for 300 seconds. Then, after washing with pure water at a temperature of 26°C for 20 seconds, it was dried at a temperature of 65°C to obtain a linear polarizer with a thickness of 12 μm in which iodine was adsorbed and oriented on the polyvinyl alcohol resin film.

[0330] [Production and preparation of protective film]

[0331] (1) Preparation of the first protective film 1

[0332] As the first protective film 1 , a film (thickness T1: 32 μm) was prepared in which a hard coat layer having a thickness of 7 μm was formed on one surface of a triacetylcellulose (TAC) film (KC2UATAC manufactured by Konica Minolta, Inc., thickness T1: 25 μm).

[0333] (2) Preparation of the Second Protective Film 1

[0334] As a supporting substrate, a polyethylene terephthalate film (PET film) having a thickness of 38 μm (TN100 manufactured by Toyobo Co., Ltd., having a release layer containing a non-silicone release agent) was prepared. Separately, the following components were blended to prepare a composition containing a thermoplastic resin.

[0335] Cyclic polyolefin resin (ZEONOR ZF14 manufactured by ZEON Corporation of Japan): 10 parts

[0336] Cyclohexane: 90 parts

[0337] On the release layer of the supporting substrate, a composition containing the above-mentioned thermoplastic resin was applied by a back coating method using a mold, and the coated layer was dried under the conditions of 40° C. for 1 minute, 70° C. for 1 minute, and 120° C. for 2 minutes, thereby preparing a laminate having a cyclic polyolefin-based resin layer with a thickness T2 of 2 μm as the second protective film 1. The moisture permeability of the second protective film 1 is 63 g / m 2 / 24hr.

[0338] (3) Preparation of the Second Protective Film 2

[0339] A laminate having a cyclic polyolefin resin layer with a thickness T2 of 3 μm as the second protective film 2 was prepared in the same manner as the preparation of the second protective film 1 except that the coating amount of the composition containing the thermoplastic resin on the release layer of the supporting substrate was changed. The moisture permeability of the second protective film 2 was 37 g / m 2 / 24hr.

[0340] (4) Preparation of the Second Protective Film 3

[0341] A laminate having a cyclic polyolefin resin layer with a thickness T2 of 4 μm as the second protective film 3 was prepared in the same manner as the preparation of the second protective film 1 except that the coating amount of the composition containing the thermoplastic resin on the release layer of the supporting substrate was changed. The moisture permeability of the second protective film 3 was 19 g / m 2 / 24hr.

[0342] (5) Preparation of the Second Protective Film 4

[0343] A cyclic polyolefin resin film having a thickness T2 of 13 μm was prepared as the second protective film 4. The moisture permeability of the second protective film 4 was 4.8 g / m 2 / 24hr.

[0344] (6) Preparation of the Second Protective Film 5

[0345] A triacetyl cellulose film having a thickness of 25 μm was prepared as the second protective film 5. The moisture permeability of the second protective film 5 was 1280 g / m 2 / 24 hr.

[0346] [Preparation of active energy ray-curable adhesive]

[0347] (1) Preparation of Active Energy Ray-Curing Adhesive 1

[0348] The following components were blended and mixed, and then degassed to prepare an active energy ray-curable adhesive 1 (hereinafter, simply referred to as "adhesive 1").

[0349] (Cationically polymerizable compound)

[0350] 3',4'-Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Corporation): 70 parts

[0351] Neopentyl glycol diglycidyl ether (trade name: EX-211, manufactured by Nagase ChemteX Co., Ltd.): 20 parts

[0352] 2-Ethylhexyl glycidyl ether (trade name: EX-121, manufactured by Nagase ChemteX Co., Ltd.): 10 parts

[0353] (Photocationic polymerization initiator)

[0354] Trade name: CPI-100 (manufactured by San-Apro Co., Ltd., 50% propylene carbonate solution): 4.5 parts (substantial solid content: 2.25 parts)

[0355] (Photosensitizing agent)

[0356] 1,4-Diethoxynaphthalene: 2 parts

[0357] [Preparation of Adhesive Layer]

[0358] The following pressure-sensitive adhesive layer 1 and pressure-sensitive adhesive layer 2 were prepared, both surfaces of which were bonded to release films.

[0359] (1) Preparation of Adhesive Layer 1

[0360] The pressure-sensitive adhesive layer 1 was prepared by the following procedure. The pressure-sensitive adhesive layer 1 was mainly used as a linear polarizing plate-phase element bonding adhesive layer in the examples described below, and was used as a phase element intra-bonding adhesive layer in some examples.

[0361] (1-1) Preparation of acrylic resin solution 1

[0362] A mixed solution of 100 parts of ethyl acetate, 99.0 parts of butyl acrylate, 0.5 parts of 2-hydroxyethyl acrylate and 0.5 parts of acrylic acid was added to a reaction vessel equipped with a condenser, a nitrogen inlet tube, a thermometer and a stirrer, and the internal temperature was raised to 55°C while replacing the air in the device with nitrogen to make it oxygen-free. Then, the entire amount of a solution prepared by dissolving 0.12 parts of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. After adding the polymerization initiator, the temperature was maintained for 1 hour. Then, while the internal temperature was maintained at 54-56°C, ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts / hr. The addition of ethyl acetate was stopped at the moment when the concentration of the acrylic resin reached 35% by mass, and the temperature was further maintained at the same temperature until 6 hours had passed since the addition of ethyl acetate was started. Finally, ethyl acetate was added to adjust the concentration of the acrylic resin to 20% by mass, and an acrylic resin solution 1 was prepared. The weight average molecular weight Mw of the obtained acrylic resin was 1.7 million. It should be noted that Mw is measured as follows: two "TSKgel GMHHR-H(S)" manufactured by Tosoh Corporation are connected in series in a GPC apparatus as columns, tetrahydrofuran is used as an eluent, and the measurement is performed by standard polystyrene conversion under the conditions of a sample concentration of 2 mg / mL, a sample introduction volume of 100 μL, a temperature of 40°C, and a flow rate of 1 mL / min.

[0363] (1-2) Preparation of Adhesive Composition 1

[0364] To 80 parts of the solid content of the acrylic resin solution 1 obtained in the above (1-1), 20 parts (solid content) of a difunctional acrylate (obtained from Shin-Nakamura Chemical Co., Ltd.; product number "A-DOG"), 2.5 parts of a cross-linking agent (Mitsui Chemicals: trade name "D-101E" (ethyl acetate solution of trimethylolpropane adduct of toluene diisocyanate (solid content concentration 75 mass %)) based on the effective ingredient, 1.5 parts of a photopolymerization initiator (Ciba Specialty Chemicals: trade name "Irgacure 500"), and 0.3 parts of a silane coupling agent (Shin-Etsu Chemical Co., Ltd.: trade name "KBM-403") were added, and ethyl acetate was further added in such a way that the solid content concentration became 13%, thereby obtaining an adhesive composition 1.

[0365] A-DOG is a diacrylate of an acetal compound of hydroxypivaldehyde and trimethylolpropane, and has the following structure.

[0366] [Chemical formula 6]

[0367]

[0368] (1-3) Preparation of Adhesive Layer 1

[0369] Using an applicator, the adhesive composition 1 prepared in the above (1-2) was applied to the release-treated surface of a release film formed by a polyethylene terephthalate film subjected to a release treatment [Mitsubishi Chemical: MRV (V04) (thickness: 38 μm)] in such a manner that the thickness T3 after drying becomes 5 μm, and dried at 100°C for 1 minute to prepare an adhesive layer (adhesive sheet). Next, the surface of the obtained adhesive layer on the side opposite to the release film side was bonded to the release-treated surface of a release film formed by a polyethylene terephthalate film subjected to a release treatment [Mitsubishi Chemical: MRF (thickness: 38 μm)]. Next, ultraviolet rays were irradiated under the following conditions to prepare an adhesive layer 1. The storage modulus G' of the adhesive layer 1 at a temperature of 85°C was 0.125 MPa.

[0370] <UV irradiation conditions>

[0371] ·Using Fusion UV lamp system (Fusion UV Systems) H Bulb ·The cumulative light amount of UVA in the UV wavelength range is 250mJ / cm 2 (Measurement device: measured value based on UV Power Puck II manufactured by FusionUV)

[0372] (2) Preparation of Adhesive Layer 2

[0373] The acrylic pressure-sensitive adhesive layer 2 was prepared in the following procedure. The pressure-sensitive adhesive layer 2 contains an antistatic agent and is used as a pressure-sensitive adhesive layer to be bonded to the side of the phase element opposite to the linear polarizing plate side in the Examples described below.

[0374] (2-1) Preparation of acrylic resin solution 2

[0375] A monomer mixture prepared by diluting 42.5 parts by mass of n-butyl acrylate, 5 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of methyl acrylate, 30 parts by mass of 2-methoxyethyl acrylate, 1.0 parts by mass of 2-hydroxyethyl acrylate and 1.5 parts by mass of acrylic acid with ethyl acetate was placed in a reaction vessel equipped with a condenser, a nitrogen inlet tube, a thermometer and a stirrer, and the internal temperature was raised to 55° C. while replacing the air in the apparatus with nitrogen to exclude oxygen. Then, a solution prepared by dissolving azobisisobutyronitrile in ethyl acetate as a polymerization initiator was added so that the amount of azobisisobutyronitrile was 0.3 parts by mass relative to 100 parts by mass of the total amount of the monomers. After the addition of the polymerization initiator, the 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 / hr while the internal temperature was maintained at 54 to 56° C. The addition of ethyl acetate was stopped when the concentration of the acrylic resin reached 35%, and the temperature was further maintained at 55° C. until 12 hours had passed since the addition of ethyl acetate was started. Then, ethyl acetate was added to adjust the concentration of the acrylic resin to 20%, thereby preparing an acrylic resin solution 2. The weight average molecular weight Mw of the obtained acrylic resin was 1,580,000.

[0376] (2-2) Preparation of Adhesive Composition 2

[0377] Adhesive composition 2-1

[0378] To 100 parts by mass of the solid content of the acrylic resin solution 2 obtained above, 0.5 parts by mass, based on the effective ingredient, of a cross-linking agent, "D-103" (an ethyl acetate solution of a trimethylolpropane adduct of toluene diisocyanate) manufactured by Mitsui Chemicals, Inc. (solid content concentration 75% by mass), 0.5 parts by mass, based on the effective ingredient, of a silane compound, "KBM-403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and 0.54 parts by mass, based on the effective ingredient, of an ionic compound, tributylmethylammonium bis(trifluoromethanesulfonyl)imide, were added, and ethyl acetate was further added in such a manner that the solid content concentration became 14%, thereby obtaining an adhesive composition 2-1 for preparing an adhesive layer "AS-PSA1" described later.

[0379] Adhesive composition 2-2

[0380] A PSA composition 2-2 for preparing a PSA layer "AS-PSA2" described below was obtained in the same manner as in the preparation of "(AS-PSA1)" except that the ionic compound was changed to 0.47 parts by mass of butylmethylpyrrolidinium bis(trifluoromethanesulfonyl)imide based on the active ingredient.

[0381] Adhesive composition 2-3

[0382] An adhesive composition 2-3 for preparing the adhesive layer "AS-PSA3" described later was obtained in the same manner as the preparation of the above-mentioned "(AS-PSA1)" except that the ionic compound was changed to 0.51 parts by mass of 4-methyl-1-octylpyridinium bis(trifluoromethanesulfonyl)imide based on the active ingredient.

[0383] Adhesive composition 2-4

[0384] Adhesive composition 2-4 for preparing adhesive layer "AS-PSA4" described later was obtained in the same manner as in the preparation of "(AS-PSA1)" except that the ionic compound was changed to 0.41 parts by mass of 4-methyl-1-octylpyridinium hexafluorophosphate based on the active ingredient.

[0385] (2-3) Preparation of Adhesive Layers AS-PSA1, AS-PSA2, AS-PSA3, and AS-PSA4

[0386] Using an applicator, the adhesive composition 2-1 obtained above was applied to the release-treated surface of a release film (1) (manufactured by Mitsubishi Chemical Co., Ltd., trade name "MRV38 (V04)", thickness: 38 μm) in a manner such that the thickness after drying was 15 μm, and then dried at a temperature of 100°C for 1 minute to obtain an adhesive layer (1) with a thickness of 15 μm. A release film (2) (manufactured by Mitsubishi Chemical Co., Ltd., trade name "MRF38", thickness: 38 μm) was laminated on the side of the obtained adhesive layer (1) opposite to the release film (1) so that the release-treated surface became the adhesive layer (1) side. The obtained laminate was allowed to stand for more than 7 days under an environment of a temperature of 23°C and a relative humidity of 60%, to obtain an adhesive layer AS-PSA1. In addition, except for using adhesive compositions 2-2, 2-3, and 2-4 as adhesive compositions, the same operation as above was performed to obtain adhesive layers AS-PSA2, AS-PSA3, and AS-PSA4, respectively. In addition, these adhesive layers AS-PSA1, AS-PSA2, AS-PSA3, and AS-PSA4 are collectively referred to as "adhesive layer 2".

[0387] [Production of Phase Element]

[0388] (1) Preparation of Phase Difference Film A

[0389] (1-1) Preparation of Photo-Alignment Film-Forming Composition A

[0390] The photo-alignment material of the following structure (weight average molecular weight: 50000, m:n=50:50) was prepared according to the method described in Japanese Patent Application Publication No. 2021-196514. 2 parts of the photo-alignment material and 98 parts of cyclopentanone (solvent) were mixed as components, and the obtained mixture was stirred at 80° C. for 1 hour to prepare a photo-alignment film-forming composition A.

[0391] Photo-oriented materials:

[0392] [Chemical formula 7]

[0393]

[0394] (1-2) Production of polymerizable liquid crystal compound

[0395] A polymerizable liquid crystal compound (A1) and a polymerizable liquid crystal compound (A2) having the structures shown below were prepared respectively. The polymerizable liquid crystal compound (A1) was prepared in the same manner as described in Japanese Patent Publication No. 2019-003177. The polymerizable liquid crystal compound (A2) was prepared in the same manner as described in Japanese Patent Publication No. 2009-173893.

[0396] Polymerizable liquid crystal compound (A1):

[0397] [Chemical formula 8]

[0398]

[0399] Polymerizable liquid crystal compound (A2):

[0400] [Chemical formula 9]

[0401]

[0402] 1 mg of polymerizable liquid crystal compound (A1) was dissolved in 10 mL of chloroform to obtain a solution. The obtained solution was added to a measuring cuvette with an optical path length of 1 cm as a measuring sample, and the measuring sample was set in an ultraviolet visible spectrophotometer ("UV-2450" manufactured by Shimadzu Corporation) to measure the absorption spectrum. The wavelength reaching the maximum absorbance was read from the obtained absorption spectrum, and the maximum absorption wavelength λmax in the range of 300 to 400 nm was 356 nm.

[0403] (1-3) Preparation of Phase Difference Film Forming Composition A

[0404] The polymerizable liquid crystal compound (A1) and the polymerizable liquid crystal compound (A2) were mixed in a mass ratio of 90:10 to obtain a mixture. 0.1 parts of a leveling agent "BYK-361N" (manufactured by BM Chemie) and 3 parts of "Irgacure OXE-03" (manufactured by BASF Japan Co., Ltd.) as a photopolymerization initiator were added to 100 parts of the obtained mixture. In addition, N-methyl-2-pyrrolidone (NMP) was added in such a way that the solid content concentration became 13%. The mixture was stirred at a temperature of 80°C for 1 hour to prepare a phase difference film forming composition A.

[0405] (1-4) Preparation of Phase Difference Film A

[0406] The composition A for forming a photo-alignment film was applied to a biaxially stretched polyethylene terephthalate (PET) film (DIAFOIL; manufactured by Mitsubishi Plastics Co., Ltd.) as a substrate A using a rod coater. The obtained coating film was dried at 120°C for 2 minutes and then cooled to room temperature to form a dry film. Then, a UV irradiation device (SPOT CURE SP-9; manufactured by USHIO Electric Co., Ltd.) was used to irradiate 100 mJ (313 nm reference) of polarized ultraviolet light to obtain a photo-alignment film A. The film thickness of the photo-alignment film A measured using an ellipsometer M-220 manufactured by JASCO Corporation was 100 nm.

[0407] The above-mentioned phase difference film forming composition A was applied to the obtained photo-alignment film A using a rod coater to form a coating film. The coating film was heated and dried at 120°C for 2 minutes and then cooled to room temperature to obtain a dry film. Next, a high-pressure mercury lamp ("Unicure VB-15201BY-A" manufactured by USHIO Electric Co., Ltd.) was used to irradiate the above-mentioned dry film in a nitrogen atmosphere with an exposure amount of 500mJ / cm 2 The polymerizable liquid crystal compound was oriented in the horizontal direction relative to the substrate surface by ultraviolet light (365 nm), thereby forming a phase difference film A that was cured, and a laminate A including substrate A / photo-aligned film A / phase difference film A was obtained. The film thickness of the phase difference film A measured using a laser microscope LEXT OLS4100 manufactured by Olympus Corporation was 2.0 μm.

[0408] The surface of the phase difference film A of the laminate A was subjected to corona treatment, and the laminate was bonded to glass via a 25 μm thick adhesive layer (manufactured by LINTEC), and the substrate A was peeled off and removed. The in-plane phase difference values ​​for light of wavelengths of 450 nm, 550 nm, and 650 nm were obtained by the Cauchy dispersion formula obtained from the measurement results of the in-plane phase difference values ​​for light of wavelengths of 448.2 nm, 498.6 nm, 548.4 nm, 587.3 nm, 628.7 nm, and 748.6 nm.

[0409] As a result, the in-plane retardation values ​​were Re(450)=122 nm, Re(550)=140 nm, and Re(650)=144 nm, and the relationship between the in-plane retardation values ​​at each wavelength was as follows.

[0410] Re(450) / Re(550)=0.87

[0411] Re(650) / Re(550)=1.03

[0412] (Wherein, Re(450) represents the in-plane phase difference value relative to light with a wavelength of 450 nm, Re(550) represents the in-plane phase difference value relative to light with a wavelength of 550 nm, and Re(650) represents the in-plane phase difference value relative to light with a wavelength of 650 nm.)

[0413] (2) Preparation of Phase Difference Film B

[0414] (2-1) Preparation of Alignment Film Forming Composition B

[0415] 2-Butoxyethanol was added to SUNEVER SE-610 (manufactured by Nissan Chemical Industries, Ltd.), which is a commercially available aligning polymer, so that the solid content became 1%, thereby obtaining an alignment film-forming composition B.

[0416] (2-2) Preparation of Phase Difference Film Forming Composition B

[0417] 100 parts of polymerizable liquid crystal compound Paliocolor LC242 (manufactured by BASF Japan), 0.1 parts of leveling agent "BYK-361N" (manufactured by BYK-Chemie) and 2.5 parts of photopolymerization initiator "Omnirad907" (manufactured by IGM Resin BV) were mixed. In addition, 400 parts of propylene glycol 1-monomethyl ether 2-acetate (PGME) were added, and the obtained mixture was stirred at a temperature of 80° C. for 1 hour to prepare a phase difference film forming composition B.

[0418] Polymerizable liquid crystal compound LC242:

[0419] [Chemical formula 10]

[0420]

[0421] (2-3) Preparation of Phase Difference Film B

[0422] As substrate B, a cyclic olefin resin (COP) film (ZF14 manufactured by ZEON Co., Ltd., Japan) was used, and one side thereof was subjected to corona treatment using a corona treatment device (AGF-B10 manufactured by Kasuga Electric Co., Ltd.), and the composition for forming an alignment film B was applied to the surface thereof using a bar coater, and dried at 90° C. for 1 minute. The film thickness of the obtained alignment film B was measured using a laser microscope and found to be 30 nm.

[0423] The retardation film forming composition B was applied to the obtained oriented film B using a bar coater and dried at 90°C for 1 minute to obtain a dry film. The dry film was irradiated with an exposure dose of 1000 mJ / cm2 using a high pressure mercury lamp ("Unicure VB-15201BY-A" manufactured by USHIO Electric Co., Ltd.) in a nitrogen atmosphere. 2 The retardation film B was formed by applying ultraviolet light (365 nm standard) to obtain a laminate B including substrate B / alignment film B / retardation film B. The film thickness of the retardation film B measured using a laser microscope LEXT OLS4100 manufactured by Olympus Corporation was 450 nm.

[0424] The phase difference values ​​were measured and found to be Re(550)=1 nm and Rth(550)=-75 nm. Laminated body B has the optical properties shown by nx≈ny<nz. It should be noted that the phase difference value at a wavelength of 550 nm of COP is approximately 0, so it has no effect on the optical properties.

[0425] (3) Fabrication of Phase Element 1

[0426] The phase difference film A of the stack A and the phase difference film B of the stack B are subjected to corona treatment respectively. An adhesive is applied to the corona-treated surface of either the phase difference film A or the phase difference film B, and the stack A and the stack B are bonded together. The adhesive 1 mentioned above is used as the adhesive. The corona treatment device is AGF-B10 manufactured by Kasuga Electric Co., Ltd. The corona treatment is performed once using the above-mentioned corona treatment device under the conditions of an output power of 0.3 kW and a treatment speed of 3 m / min. The adhesive 1 is cured by irradiating ultraviolet rays from the stack A side to form an adhesive layer 1 with a thickness of 1.5 μm. The UVA with a wavelength of 320 nm to 390 nm becomes 420 mJ / cm 2 Through the above operation, a phase element 1 with a substrate including substrate A / photo-alignment film A / phase difference film A / adhesive layer 1 / phase difference film B / alignment film B / substrate B was prepared.

[0427] (4) Fabrication of Phase Element 2

[0428] In the preparation of phase element 1, in the lamination of laminated body A and laminated body B, adhesive layer 1 is used instead of adhesive 1 to prepare phase element, and the same operation as phase element 1 is performed to prepare phase element 2. Through the above operation, a phase element 2 with a substrate including substrate A / photo-alignment film A / phase difference film A / adhesive layer 1 / phase difference film B / alignment film B / substrate B is prepared.

[0429] <Examples 1 to 12, Comparative Example 1>

[0430] The first protective film 1 prepared above, a polarizer selected from the polarizers 1 to 2, a protective film selected from the second protective films 1 to 5, and a phase element selected from the phase elements 1 to 2 are bonded together. Next, an adhesive layer is laminated on the surface of the phase element on the side opposite to the second protective film side to obtain optical laminates of Examples 1 to 12 and Comparative Example 1. Specifically, it is as follows.

[0431] The surface of the first protective film and the surface of the second protective film (when a laminate having a second protective film is used, the surface of the second protective film of the laminate) are respectively subjected to corona treatment. A water-based adhesive is applied to one side of the polarizer, and the first protective film is attached. A water-based adhesive is applied to the other side of the polarizer, and the second protective film (or the laminate having the second protective film) is attached. Then, it is dried to obtain a polarizing plate. The above-mentioned water-based adhesive is obtained by dissolving 3 parts of carboxyl-modified polyvinyl alcohol [trade name "KL-318" obtained from Kuraray Co., Ltd.] in 100 parts of water, and adding 1.5 parts of a polyamide epoxy additive as a water-soluble epoxy resin [trade name "Sumirez Resin 650 (30)" manufactured by Tanaoka Chemical Industry Co., Ltd., a 30% solid content concentration aqueous solution]. Through the above operation, a laminate X (linear polarizing plate) comprising the first protective film / adhesive layer / polarizer / adhesive layer / second protective film is obtained. Here, when a laminate having a second protective film is used, the laminate X becomes the first protective film / adhesive layer / polarizer / adhesive layer / second protective film / support substrate.

[0432] Next, the surface of the second protective film of the above-mentioned stack X (when the stack X has a supporting substrate, the surface of the supporting substrate is peeled off) and the surface exposed by peeling off the substrate A of the phase element are respectively subjected to corona treatment. The corona treatment device uses AGF-B10 manufactured by Kasuga Electric Co., Ltd. The corona treatment is performed once under the conditions of an output power of 0.3 kW and a processing speed of 3 m / min using the above-mentioned corona treatment device. The corona-treated surface of the stack X is bonded to the corona-treated surface of the phase element via the above-mentioned adhesive layer 1. Then, the substrate B of the phase element is peeled off and removed to obtain a stack Y comprising the first protective film / adhesive layer / polarizer / adhesive layer / second protective film / adhesive layer 1 / optical orientation film A / phase difference film A / phase element internal bonding adhesive layer / phase difference film B / orientation film B in sequence. Finally, the above-mentioned adhesive layer 2 is laminated on the surface of the phase difference film B side of the stack Y to obtain an optical stack. The obtained optical layered body was evaluated using a phase difference measuring device (manufactured by Oji Scientific Instruments Co., Ltd., KOBRA-WPR). As a result, the in-plane phase difference value and wavelength dispersion of the phase element were Re(550)=140 nm and α=0.87, respectively.

[0433] The types of the first protective film, polarizer, second protective film, phase element, and adhesive layer (adhesive layer laminated on the surface of the phase element opposite to the second protective film) used in Examples 1 to 12 and Comparative Example 1 are shown in the following table. In addition, the results of the evaluation of the phase difference change amount and the evaluation of metal corrosion performed on each optical laminate are shown in the following table.

[0434] [Table 1]

[0435]

[0436] [Table 2]

[0437]

[0438] According to the results shown in Tables 1 and 2, when the moisture permeability of the second protective film is low and the adhesive layer contains a specified antistatic material, the change in the phase difference characteristics and the metal corrosion are sufficiently suppressed (comparison of Examples 1 to 12 with Comparative Example 1). It can also be seen that when the adhesive layer 1 is used as the adhesive layer for bonding the phase element, the degree of suppression of metal corrosion is slightly weakened (Examples 7, 10, and 12). It can also be seen that if the thickness of the second protective film becomes thicker, the degree of suppression of metal corrosion is slightly weakened (Examples 9 to 12). It can also be seen that if the thickness of the second protective film becomes too thin, the degree of suppression of metal corrosion is slightly weakened (Examples 2 and 5).

[0439] Industrial Applicability

[0440] The present invention can be used as a circular polarizing plate.

[0441] Description of Reference Numerals

[0442] 1…optical laminate, 2…linear polarizing plate, 3…adhesive layer between linear polarizing plate and phase element, 4…phase element, 5…adhesive layer, 21…first protective film, 22…polarizer, 23…second protective film, 41…first phase difference layer, 42…adhesive layer in phase element, 43…second phase difference layer.

Claims

1. An optical laminate comprising, in order, a first protective film, a polarizing plate, a second protective film, a phase element, and an adhesive layer. The moisture permeability of the second protective film is 1200 g / (m 2 Days) or less, The adhesive layer contains an antistatic agent, The antistatic agent comprises an ionic compound, wherein the ionic compound comprises an organic cation and an anion represented by the following formula (1): (C n F 2n+1 SO2)2N - (1) In formula (1), n ​​is an integer of 0-5.

2. The optical layered body according to claim 1, wherein: The water vapor permeability coefficient of the phase element is 100 or less.

3. The optical layered body according to claim 1, wherein: The phase element includes a first phase difference layer, a bonding adhesive layer, and a second phase difference layer, and the phase element has a λ / 4 plate function in the entire visible light region.

4. The optical laminate according to claim 3, wherein: The adhesive layer includes an active energy ray-curable adhesive.

5. The optical layered body according to claim 1, wherein: The second protective film includes a cyclic polyolefin-based resin.

6. The optical layered body according to claim 1, wherein: The second protective film has a thickness of 1 μm to 10 μm.

7. The optical layered body according to claim 1, wherein: The moisture permeability of the first protective film is 100 g / (m 2 · days) or more.

8. The optical layered body according to claim 1, wherein: The ionic compound includes an organic cation containing a nitrogen atom. 9 . An image display device comprising the optical layered body according to claim 1 and an image display panel to which the optical layered body is bonded.

Images