Active energy ray-curable adhesive composition and optical laminate

Abstract

To provide an active energy ray-curable adhesive composition suitable for forming an optical laminate excellent in interlayer adhesion and durability.SOLUTION: The active energy ray-curable adhesive composition comprises the following curable compounds: a) a urethane (meth)acrylate having two or less (meth)acrylic groups in the molecule; b) a (meth)acrylate having no aromatic ring and having a hydroxyl group in the molecule; c) a (meth)acrylate having no hydroxyl group and having two or more aromatic rings in the molecule; and d) a (meth)acrylate having one aromatic ring in the molecule.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an active energy ray-curable adhesive composition, and an optical laminate including an adhesive layer that is a cured layer of the active energy ray-curable adhesive composition, and a liquid crystal retardation film adjacent to the adhesive layer. [Background technology]

[0002] Image display devices such as organic EL display devices include many optical components such as polarizing plates and retardation plates, and pressure-sensitive adhesives and adhesives are widely used to bond these components together. For example, Patent Document 1 discloses a reflective circular polarization separation element in which a cholesteric resin layer and a quarter-wave plate are bonded together with a cured adhesive layer as a brightness enhancement film. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-112720 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, in response to demands for thinner image display panels and the like, thin-film retardation films and polarizing films formed from compositions containing liquid crystal compounds have been used as constituent members thereof. However, optical laminates including retardation films formed from compositions containing such liquid crystal compounds may be inferior in interlayer adhesion and durability under high-temperature conditions. An object of the present invention is to provide an active energy ray-curable adhesive composition suitable for forming an optical laminate having excellent interlayer adhesion and durability. [Means for solving the problem]

[0005] The present inventors have conducted extensive research to solve the above problems and have completed the present invention. That is, the present invention includes the following preferred embodiments. [1] A curable compound of: a) Urethane (meth)acrylate having two or less (meth)acrylic groups in the molecule b) (Meth)acrylates that do not have an aromatic ring in the molecule and have a hydroxyl group c) (meth)acrylates having no hydroxyl groups in the molecule and having two or more aromatic rings, and d) (Meth)acrylates having one aromatic ring in the molecule An active energy ray-curable adhesive composition comprising: [2] The active energy ray-curable adhesive composition according to [1] above, wherein the (meth)acrylate having one aromatic ring in the molecule of d) further has at least one hydroxyl group. [3] The active energy ray-curable adhesive composition according to [1] or [2], which contains, relative to 100 parts by mass of the total amount of curable compounds contained in the adhesive composition, a) 1 to 30 parts by mass of a urethane (meth)acrylate having two or less (meth)acrylic groups in the molecule. [4] The active energy ray-curable adhesive composition according to any one of [1] to [3], further comprising: b) 15 to 60 parts by mass of a (meth)acrylate having no aromatic ring and a hydroxyl group in the molecule, relative to 100 parts by mass of the total amount of curable compounds contained in the adhesive composition. [5] The active energy ray-curable adhesive composition according to any one of [1] to [4], further comprising: c) 10 to 60 parts by mass of a (meth)acrylate having no hydroxyl group in the molecule and two or more aromatic rings, relative to 100 parts by mass of the total amount of curable compounds contained in the adhesive composition. [6] The active energy ray-curable adhesive composition according to any one of [1] to [5], further comprising 3 to 40 parts by mass of d) a (meth)acrylate having one aromatic ring in the molecule, relative to 100 parts by mass of the total amount of curable compounds contained in the adhesive composition. [7] The active energy ray-curable adhesive composition according to any one of [1] to [6] above, further comprising 0.5 to 10 parts by mass of a polymerization initiator per 100 parts by mass of the total amount of the curable compounds contained in the adhesive composition. [8] The polymerization initiator has a molar absorption coefficient of 10 L mol in acetonitrile solvent at a light source wavelength of 400 nm. -1 ·cm -1 The active energy ray-curable adhesive composition according to [7] above. [9] An optical laminate comprising an adhesive layer which is a cured layer of the active energy ray-curable adhesive composition according to any one of [1] to [8] above, and a liquid crystal retardation film adjacent to the adhesive layer.

[10] The optical laminate according to [9], further comprising a hard coat layer on the side of the adhesive layer opposite to the liquid crystal retardation film.

[11] The optical laminate according to

[10] , further comprising a polarizing film on the side of the hard coat layer opposite to the adhesive layer.

[12] The optical laminate according to

[11] , wherein the polarizing film is a cured layer of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound and a dichroic dye.

[13] The optical laminate according to

[12] , comprising a polarizing film, an alignment film, a hard coat layer, an adhesive layer, and a liquid crystal retardation film, arranged adjacent to each other in this order.

[14] When the in-plane average refractive index of the hard coat layer is n1, the in-plane average refractive index of the liquid crystal retardation film is n2, and the in-plane average refractive index of the adhesive layer is n3, the following formula is satisfied: |(n1×n2) 1 / 2 -n3| ≦ 0.018 The optical layered body according to any one of the above

[10] to

[13] , which satisfies the above. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide an active energy ray-curable adhesive composition suitable for forming an optical laminate having excellent interlayer adhesion and durability. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described in detail. Note that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention.

[0008] <Active energy ray-curable adhesive composition> The active energy ray-curable adhesive of the present invention (hereinafter also simply referred to as "adhesive composition (1)") is a) Urethane (meth)acrylate having two or less (meth)acryloyl groups in the molecule b) (meth)acrylates having no aromatic rings in the molecule and having a hydroxyl group; c) (meth)acrylates that do not have a hydroxyl group in the molecule and have two or more aromatic rings, and d) (Meth)acrylates having one aromatic ring in the molecule The active energy ray-curable adhesive composition comprises: In this specification, the term "(meth)acrylate" refers to an acrylate or a methacrylate, and the term "(meth)acryloyl group" refers to an acryloyl group or a methacryloyl group.

[0009] Conventionally, many circular polarizing plates are formed by laminating a retardation film and a polarizing film via an adhesive layer. However, when the retardation film is a liquid crystal retardation film formed from a composition containing a liquid crystal compound, the retardation value may decrease under high-temperature conditions. The present inventors have found that the decrease in retardation value under high-temperature conditions can be effectively suppressed by forming an adhesive layer for laminating the liquid crystal retardation film to another layer from an active energy ray-curable adhesive composition containing the specific curable compounds a) to d) above. Hereinafter, in this specification, the effect of suppressing the decrease in the retardation value of the retardation film under high-temperature conditions will be expressed as (excellent in) durability, etc.

[0010] <Active energy ray curing adhesive> The adhesive composition (1) of the present invention contains the curable compounds a) to d) above. In the adhesive composition (1), a) a urethane (meth)acrylate having two or less (meth)acryloyl groups in the molecule (hereinafter also referred to as "urethane (meth)acrylate (a)") is a curable compound that can function as a base polymer for forming an adhesive layer. Urethane (meth)acrylate generally refers to a reaction product of an isocyanate compound, a polyol compound, and a (meth)acrylate compound. The urethane (meth)acrylate (a) has two or less (meth)acryloyl groups in the molecule, i.e., usually one or two (meth)acryloyl groups. Two (meth)acryloyl groups facilitate the formation of a crosslinked structure, thereby improving the adhesion of the resulting adhesive and imparting appropriate toughness. Therefore, the urethane (meth)acrylate (a) is preferably a bifunctional urethane (meth)acrylate having two (meth)acryloyl groups in the molecule.

[0011] The urethane (meth)acrylate (a) is not particularly limited as long as it has two or less (meth)acryloyl groups in the molecule, and known urethane (meth)acrylate compounds can be used. Specific examples include those obtained by reacting a terminal isocyanate urethane prepolymer obtained by reacting a polyester-type or polyether-type polyol compound with a polyisocyanate compound (e.g., 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc.), with a (meth)acrylate having a hydroxyl group (e.g., 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol (meth)acrylate, etc.). The urethane (meth)acrylate (a) may be used alone or in combination of two or more. In addition, a commercially available product may be used as the urethane (meth)acrylate (a). Even if a (meth)acrylate compound having two or less (meth)acryloyl groups in the molecule has, for example, a urethane bond and a hydroxyl group, in this specification, the (meth)acrylate is classified as the urethane (meth)acrylate (a) as long as it has a urethane bond.

[0012] The weight-average molecular weight (Mw) of the urethane (meth)acrylate (a), in terms of polystyrene, is preferably 300 or more, more preferably 400 or more, even more preferably 500 or more, particularly preferably 600 or more, and preferably 50,000 or less, more preferably 30,000 or less, even more preferably 10,000 or less, even more preferably 5,000 or less, particularly preferably 3,000 or less, and particularly preferably 2,000 or less. When the Mw of the urethane (meth)acrylate (a) is within the above range, adhesion to layers adjacent to the adhesive layer (1) is likely to be improved. Furthermore, controlling the molecular weight of the urethane (meth)acrylate (a) can further enhance the effect of suppressing the decrease in the retardation value of the liquid crystal retarder film in a high-temperature environment. The weight-average molecular weight can be measured, for example, by gel permeation chromatography (GPC).

[0013] The viscosity (40°C) of the urethane (meth)acrylate (a) is preferably 10,000 to 100,000 mPa·s, more preferably 20,000 to 70,000 mPa·s, and even more preferably 40,000 to 60,000 mPa·s. When the viscosity of the urethane (meth)acrylate (a) is within this range, the viscosity of the adhesive composition (1) can be easily controlled, and good coatability can be imparted to the adhesive composition (1). The viscosity of the urethane (meth)acrylate (a) can be measured, for example, using an E-type viscometer.

[0014] The content of the urethane (meth)acrylate (a) in the adhesive composition (1) is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and even more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the total amount of the curable compounds contained in the adhesive composition (1). When the content of the urethane (meth)acrylate (a) is within the above range, the adhesion of the resulting adhesive layer (1) can be improved. Furthermore, the viscosity of the adhesive composition (1) can be easily adjusted, and good coatability can be imparted to the adhesive composition (1). When two or more types of urethane (meth)acrylate (a) are contained, it is preferable that the total content thereof is within the above range.

[0015] In the adhesive composition (1), b) a (meth)acrylate having no aromatic ring in the molecule and having a hydroxyl group (hereinafter also referred to as "hydroxyl group-containing (meth)acrylate (b)") preferably functions as an adhesion promoter. The number of hydroxyl groups in the hydroxyl group-containing (meth)acrylate (b) is usually 1 to 3, preferably 1 to 2, and more preferably 1 in the molecule. The number of (meth)acryloyl groups in the hydroxyl group-containing (meth)acrylate (b) may be, for example, 1 to 6, preferably 1 to 2, and in a preferred embodiment of the present invention, 1. The hydroxyl group-containing (meth)acrylate (b) is not particularly limited, and can be selected from known hydroxyl group-containing (meth)acrylate compounds. Specific examples of the hydroxyalkyl (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate; 2-hydroxyethyl acryloyl phosphate; 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate; caprolactone-modified 2-hydroxyethyl (meth)acrylate; dipropylene glycol (meth)acrylate; fatty acid-modified glycidyl (meth)acrylate; polyethylene glycol mono(meth)acrylate; polypropylene glycol mono(meth)acrylate; Examples of the hydroxyl group-containing (meth)acrylate (b) include pyrene glycol mono(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl(meth)acrylate, glycerin di(meth)acrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, pentaerythritol tri(meth)acrylate, caprolactone-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, caprolactone-modified dipentaerythritol penta(meth)acrylate, ethylene oxide-modified dipentaerythritol penta(meth)acrylate, etc. As the hydroxyl group-containing (meth)acrylate (b), one type may be used alone, or two or more types may be used in combination.

[0016] The content of the hydroxyl group-containing (meth)acrylate (b) in the adhesive composition (1) is preferably 15 to 60 parts by mass, more preferably 20 to 55 parts by mass, and even more preferably 25 to 50 parts by mass, relative to 100 parts by mass of the total amount of the curable compounds contained in the adhesive composition (1). When the content of the hydroxyl group-containing (meth)acrylate (b) is within the above range, the adhesion of the resulting adhesive layer can be improved. Furthermore, an increase in reflectance can be suppressed in relation to adjacent layers such as retardation films. Furthermore, the viscosity of the adhesive composition (1) can be easily adjusted, and good coatability can be imparted to the adhesive composition (1). On the other hand, if the content of the (meth)acrylate (b) is too low, adhesion tends to decrease. When two or more types of hydroxyl group-containing (meth)acrylate (b) are contained, it is preferable that the total content thereof be within the above range.

[0017] The adhesive composition (1) contains c) a (meth)acrylate having no hydroxyl group in the molecule and two or more aromatic rings (hereinafter also referred to as "aromatic ring-containing (meth)acrylate (c)"). When the adhesive composition (1) contains the aromatic ring-containing (meth)acrylate (c), an optical laminate including a liquid crystal retardation film adjacent to an adhesive layer formed from the adhesive composition (1) is excellent in suppressing a decrease in retardation value under high temperature conditions. The reason for this is not necessarily limited, but is presumed to be as follows: In an optical laminate in which an adhesive layer and a liquid crystal retardation film are adjacent to each other, the aromatic ring-containing (meth)acrylate (c) migrates from the adhesive layer to the liquid crystal retardation film. Since the aromatic ring-containing (meth)acrylate (c) contains two or more aromatic rings, it is a compound with a relatively high electron density. Therefore, when it migrates to the liquid crystal retardation film, it is thought to increase the retardation value of the liquid crystal retardation film. Therefore, it is presumed that the decrease in retardation value under high-temperature conditions is offset by the increase in retardation value due to the migration of the aromatic ring-containing (meth)acrylate (c) from the adhesive layer to the liquid crystal retardation film, thereby substantially suppressing the change in retardation value. Furthermore, the aromatic ring-containing (meth)acrylate (c) can also function as a high-refractive index agent in the adhesive layer. This makes it easier to approximate the in-plane average refractive index of the adhesive layer (1) to the in-plane average refractive index of the liquid crystal retardation film or the like adjacent to the adhesive layer, thereby suppressing interfacial reflection between these layers.

[0018] The number of aromatic rings contained in the aromatic ring-containing (meth)acrylate (c) in the molecule is preferably 2 to 5, more preferably 2 to 3, and even more preferably 2. When the number of aromatic rings contained in the aromatic ring-containing (meth)acrylate (c) is within the above range, the durability of the resulting optical laminate can be further improved. Furthermore, the number of (meth)acryloyl groups in the aromatic ring-containing (meth)acrylate (c) may be, for example, 1 to 6, preferably 1 to 2, and in a preferred embodiment of the present invention, is 1.

[0019] The refractive index of the aromatic ring-containing (meth)acrylate (c) is preferably 1.50 to 1.65, more preferably 1.55 to 1.60, and even more preferably 1.57 to 1.59. When the refractive index of the aromatic ring-containing (meth)acrylate (c) is within the above range, it can be expected to fully function as a high refractive index agent and to have an effect of suppressing an increase in the reflectance of the optical layered body.

[0020] Examples of the aromatic ring-containing (meth)acrylate (c) include ethoxylated-o-phenylphenol acrylate, bisphenol A type epoxy (meth)acrylate, bisphenol F type epoxy (meth)acrylate, 2-([1,1'-biphenyl]-2-yloxy)ethyl acrylate, 3-phenoxybenzyl acrylate, naphthalene-1-ylmethyl acrylate, 2-(2-([1,1'-biphenyl]-2-yloxy)ethoxy)ethyl ... Examples of such esters include 4'-hydroxy-[1,1'-biphenyl]-2-yl)oxyethyl acrylate, (naphthalen-1-ylmethoxy)methyl acrylate, 6-((4'-cyano-[1,1'-biphenyl]-4-yl)oxy)hexyl acrylate, 4-benzoylphenyl acrylate, anthracen-9-ylmethyl acrylate, [1,1'-biphenyl]-4,4'-diyl diacrylate, and 2-((4'-hydroxy-[1,1'-biphenyl]-2-yl)oxy)ethyl acrylate. Among these, ethoxylated-o-phenylphenol acrylate is preferred. These esters may be used alone or in combination of two or more.

[0021] The content of the aromatic ring-containing (meth)acrylate (c) in the adhesive composition (1) is preferably 10 to 60 parts by mass, more preferably 20 to 55 parts by mass, and even more preferably 25 to 50 parts by mass, per 100 parts by mass of the total amount of curable compounds contained in the adhesive composition (1). When the content of the aromatic ring-containing (meth)acrylate (c) is within the above range, when an adhesive layer is formed adjacent to a liquid crystal retardation film using the adhesive composition (1), a decrease in the retardation value of the liquid crystal retardation film can be suppressed, and an effect of suppressing an increase in reflectance and improving adhesion can be expected. On the other hand, if the content of the aromatic ring-containing (meth)acrylate (c) is too high, a decrease in adhesion and a decrease in retardation value are likely to occur. When two or more types of aromatic ring-containing (meth)acrylate (c) are contained, it is preferable that the total content thereof be within the above range.

[0022] The adhesive composition (1) contains a (meth)acrylate having one aromatic ring in the molecule (d) (hereinafter also referred to as "aromatic ring-containing (meth)acrylate (d)"). The aromatic ring-containing (meth)acrylate (d) preferably functions as a refractive index adjuster. The aromatic ring-containing (meth)acrylate (d) preferably has at least one hydroxyl group (hereinafter also referred to as "aromatic ring-containing (meth)acrylate (d')"). The number of hydroxyl groups in the aromatic ring-containing (meth)acrylate (d') is usually 1 to 3, preferably 1 to 2, and more preferably 1, in the molecule. By using a (meth)acrylate having a good balance of hydroxyl groups and aromatic rings, it is easy to control the refractive index of the resulting adhesive layer, and an excellent effect of suppressing interfacial reflection between layers is achieved. The number of (meth)acryloyl groups in the aromatic ring-containing (meth)acrylate (d) and the aromatic ring-containing (meth)acrylate (d') may be, for example, 1 to 6, preferably 1 to 2, and in a preferred embodiment of the present invention, 1.

[0023] The aromatic ring-containing (meth)acrylate (d) and the aromatic ring-containing (meth)acrylate (d') are not particularly limited, and can be selected from known (meth)acrylate compounds containing one aromatic ring, preferably having at least one hydroxyl group and one aromatic ring. Specific examples include 4-hydroxyphenyl acrylate, 3-hydroxyphenyl acrylate, 2-hydroxyphenyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-4-phenoxybutyl acrylate, 2-hydroxy-5-phenoxypentyl acrylate, 3-hydroxy-4-phenoxybutyl acrylate, 4-hydroxy-5-phenoxypentyl acrylate, 2-hydroxy-3-(p-tolyloxy)propyl acrylate, 2-hydroxy-3-(m-tolyloxy)propyl acrylate, 2-hydroxy-3-(o-tolyloxy)propyl acrylate, 3-hydroxy-2-phenylpropyl acrylate, 4-hydroxy-2-phenylbutyl acrylate, 4-hydroxy-3-phenylbutyl acrylate, etc. These may be used alone or in combination of two or more.

[0024] The refractive index of the aromatic ring-containing (meth)acrylate (d) and the aromatic ring-containing (meth)acrylate (d') is preferably 1.50 to 1.65, more preferably 1.50 to 1.60, and even more preferably 1.52 to 1.59. When the refractive index of the aromatic ring-containing (meth)acrylate (d) and / or the aromatic ring-containing (meth)acrylate (d') is within the above range, it is likely to fully function as a refractive index adjuster, and an effect of suppressing an increase in reflectance in an optical laminate including a layer formed from the adhesive composition can be expected.

[0025] The content of the aromatic ring-containing (meth)acrylate (d) in the adhesive composition (1) is preferably 3 to 40 parts by mass, more preferably 5 to 35 parts by mass, and even more preferably 10 to 30 parts by mass, relative to 100 parts by mass of the total amount of curable compounds contained in the adhesive composition (1). When the content of the aromatic ring-containing (meth)acrylate (d) is within the above range, an effect of suppressing an increase in reflectance and an effect of improving adhesion can be expected. In addition, the viscosity of the adhesive composition (1) can be easily adjusted, and good coatability can be imparted to the adhesive composition (1). When two or more types of aromatic ring-containing (meth)acrylate (d) are contained, it is preferable that the total content thereof is within the above range.

[0026] In one embodiment of the present invention, the adhesive composition (1) preferably contains the curable compounds a) to d) in amounts within the ranges described above.

[0027] In one embodiment of the present invention, the mass ratio of the urethane (meth)acrylate (a) to the hydroxyl group-containing (meth)acrylate (b) in the adhesive composition (1) (urethane (meth)acrylate (a) / hydroxyl group-containing (meth)acrylate (b)) is preferably 0.05 to 1.0, more preferably 0.1 to 0.9, and even more preferably 0.1 to 0.8. When the mass ratio of the urethane (meth)acrylate (a) to the hydroxyl group-containing (meth)acrylate (b) is within the above range, good coatability can be obtained and the adhesiveness of the resulting adhesive layer is likely to be improved.

[0028] In one embodiment of the present invention, the mass ratio of the urethane (meth)acrylate (a) to the aromatic ring-containing (meth)acrylate (c) in the adhesive composition (1) (urethane (meth)acrylate (a) / aromatic ring-containing (meth)acrylate (c)) is preferably 0.05 to 1.2, more preferably 0.1 to 1.0, and may be, for example, 0.5 to 1.0. When the mass ratio of the urethane (meth)acrylate (a) to the aromatic ring-containing (meth)acrylate (c) is within the above range, when an adhesive layer formed from the adhesive composition (1) is provided adjacent to a liquid crystal retardation film, an excellent effect of suppressing a decrease in the retardation value of the liquid crystal retardation film can be expected, and further effective effects of suppressing an increase in reflectance and improving adhesion can be expected.

[0029] In one embodiment of the present invention, the mass ratio of the hydroxyl group-containing (meth)acrylate (b) to the aromatic ring-containing (meth)acrylate (c) in the adhesive composition (1) (hydroxyl group-containing (meth)acrylate (b) / aromatic ring-containing (meth)acrylate (c)) is preferably 0.5 to 2.0, more preferably 0.6 to 1.8, and even more preferably 0.6 to 1.7. When the mass ratio of the hydroxyl group-containing (meth)acrylate (b) to the aromatic ring-containing (meth)acrylate (c) is within the above range, good coatability can be obtained, and the effect of suppressing a decrease in the retardation value of a liquid crystal retardation film and the effect of improving adhesion can be easily obtained.

[0030] In one embodiment of the present invention, the mass ratio of the urethane (meth)acrylate (a) to the aromatic ring-containing (meth)acrylate (d) (urethane (meth)acrylate (a) / aromatic ring-containing (meth)acrylate (d)) is preferably 0.2 to 1.0, more preferably 0.3 to 1.0, and even more preferably 0.5 to 0.9. When the mass ratio of the urethane (meth)acrylate (a) to the aromatic ring-containing (meth)acrylate (d) is within the above range, an effect of suppressing an increase in reflectance and an effect of improving adhesion can be expected, and good coatability can be obtained.

[0031] In one embodiment of the present invention, the mass ratio of the hydroxyl group-containing (meth)acrylate (b) to the aromatic ring-containing (meth)acrylate (d) (hydroxyl group-containing (meth)acrylate (b) / aromatic ring-containing (meth)acrylate (d)) is preferably 0.5 to 4.0, more preferably 1.0 to 3.5. When the mass ratio of the hydroxyl group-containing (meth)acrylate (b) to the aromatic ring-containing (meth)acrylate (d) is within the above range, an effect of suppressing an increase in reflectance and an effect of improving adhesion can be expected, and good coatability can be obtained.

[0032] In one embodiment of the present invention, the mass ratio of the aromatic ring-containing (meth)acrylate (c) to the aromatic ring-containing (meth)acrylate (d) (aromatic ring-containing (meth)acrylate (c) / aromatic ring-containing (meth)acrylate (d)) is preferably 0.5 to 6.0, more preferably 0.6 to 5.0. When the mass ratio of the aromatic ring-containing (meth)acrylate (c) to the aromatic ring-containing (meth)acrylate (d) is within the above range, when an adhesive layer formed from the adhesive composition (1) is provided adjacent to a liquid crystal retardation film, an excellent effect of suppressing a decrease in the retardation value of the liquid crystal retardation film can be expected, as well as an even greater effect of suppressing an increase in reflectance and an even greater effect of improving adhesion.

[0033] The adhesive composition (1) may contain other curable compounds in addition to the curable compounds a) to d) described above. Examples of such other curable compounds include urethane (meth)acrylates having three or more (meth)acryloyl groups in the molecule, and monofunctional or polyfunctional (meth)acrylates having neither a hydroxyl group nor an aromatic ring in the molecule.

[0034] When the adhesive composition (1) contains curable compounds other than the curable compounds a) to d), the total content thereof is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, per 100 parts by mass of the total amount of curable compounds contained in the adhesive composition (1), with the lower limit being 0 parts by mass. When the content of the curable compounds other than the curable compounds a) to d) is within the above range, the effects of the present invention obtained by the curable compounds a) to d) can be sufficiently ensured. When two or more types of curable compounds other than the curable compounds a) to d) are contained, the total content thereof is within the above range. In a preferred embodiment of the present invention, the adhesive composition (1) does not contain any curable compounds other than the curable compounds a) to d).

[0035] The adhesive composition (1) may contain a polymerization initiator. The polymerization initiator is a compound capable of initiating the polymerization reaction of a curable compound such as a urethane (meth)acrylate (a), a hydroxyl group-containing (meth)acrylate (b), an aromatic ring-containing (meth)acrylate (c), or an aromatic ring-containing (meth)acrylate (d). The polymerization initiator is preferably a photopolymerization initiator that generates active radicals by the action of light.

[0036] Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts, sulfonium salts, etc. As the polymerization initiator, one type may be used alone, or two or more types may be used in combination.

[0037] Examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

[0038] Examples of the benzophenone compound include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, and 2,4,6-trimethylbenzophenone.

[0039] Examples of alkylphenone compounds include diethoxyacetophenone, 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethan-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexyl phenyl ketone, and oligomers of 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one.

[0040] Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0041] Examples of the triazine compound include 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxynaphthyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-triazine, and 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2-yl)ethenyl]-1,3,5-triazine. 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)ethenyl]-1,3,5-triazine, and 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)ethenyl]-1,3,5-triazine.

[0042] Commercially available polymerization initiators include Irgacure® 907, 184, 651, 819, 250, and 369 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Omnirad 819, Omnirad 907, Esacure 1001M, and Esacure KIP160 (manufactured by IDM Resins BV), Seikuol® BZ, Z, and BEE (manufactured by Seiko Chemical Co., Ltd.), Kayacure® BP100 and UVI-6992 (manufactured by The Dow Chemical Company), Adeka Optomer SP-152 and SP-170 (manufactured by ADEKA Corporation), TAZ-A and TAZ-PP (manufactured by Nippon SiberHegner Co., Ltd.), and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.).

[0043] In a preferred embodiment of the present invention, the polymerization initiator used in adhesive composition (1) has a molar absorption coefficient of 10 L mol in acetonitrile solvent at a light source wavelength of 400 nm. -1 ·cm -1Preferably, the molar absorption coefficient of the polymerization initiator at a light source wavelength of 400 nm is 100 L mol or more. A polymerization initiator having such a molar absorption coefficient can generally function as an initiator in the visible light region. This is advantageous when curing an adhesive composition through a film that does not transmit light in the ultraviolet region. From the viewpoint of further enhancing the above-mentioned effect, the molar absorption coefficient of the polymerization initiator at a light source wavelength of 400 nm is more preferably 100 L mol -1 ·cm -1 More than 500 L mol -1 ·cm -1 More than 1000 L·mol -1 ·cm -1 The molar absorption coefficient of the polymerization initiator at a light source wavelength of 400 nm is usually 3000 L mol -1 ·cm -1 The molar absorption coefficient of the polymerization initiator can be measured, for example, by dissolving the polymerization initiator in acetonitrile to form a 0.001% solution, placing the solution in a 1 cm square quartz cell for measurement, and using an ultraviolet-visible spectrophotometer (UV-2450, Shimadzu Corporation).

[0044] When the adhesive composition (1) contains a polymerization initiator, the content thereof can be appropriately selected depending on the type and amount of the polymerizable compound. From the viewpoint of initiator efficiency, the content is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the total amount of the curable compounds contained in the adhesive composition (1). When the content of the polymerization initiator is within the above range, the curable compounds can be sufficiently cured.

[0045] The adhesive composition (1) may contain additives such as photosensitizers, leveling agents, antioxidants, stabilizers, flame retardants, viscosity modifiers, foam inhibitors, and antistatic agents, as needed. When the adhesive composition (1) contains other additives, the content of the other additives is preferably more than 0% and not more than 10% by mass, more preferably more than 0% and not more than 5% by mass, based on the solid content of the adhesive composition (1). In this specification, the solid content of the adhesive composition refers to all components of the adhesive composition excluding volatile components such as organic solvents. Hereinafter, when the solid content is referred to in this specification, it similarly refers to the components of the target composition excluding volatile components such as solvents.

[0046] In the present invention, the adhesive composition (1) may contain an organic solvent, for example, to adjust the viscosity to a level suitable for the coating method to be used, or may be substantially solvent-free (solvent-free). Note that "substantially solvent-free" does not exclude cases where solvent is inevitably mixed in. In one embodiment of the present invention, the adhesive composition (1) is solvent-free.

[0047] The viscosity of the adhesive composition (1) at 25°C is preferably 500 mPa·s or less, more preferably 300 mPa·s or less, and even more preferably 250 mPa·s or less. When the viscosity of the adhesive composition (1) is the above-mentioned upper limit or less, the adhesive composition (1) has good fluidity and can be applied uniformly and thinly. The lower limit of the viscosity of the adhesive composition (1) at 25°C is usually 5 mPa·s or more. The viscosity can be measured, for example, according to JIS K7117-2.

[0048] <Optical laminate> When an adhesive layer formed from the active energy ray-curable adhesive composition of the present invention is provided adjacent to a liquid crystal retardation film, the active energy ray-curable adhesive composition of the present invention is excellent in suppressing a decrease in the retardation value of the liquid crystal retardation film, and is expected to have an even greater effect of suppressing an increase in reflectance and improving adhesion. Therefore, the active energy ray-curable adhesive composition of the present invention is suitable for forming an optical laminate having excellent interlayer adhesion and durability. Therefore, the present invention is directed to an optical laminate comprising an adhesive layer (hereinafter also referred to as "adhesive layer (1)") that is a cured layer of the active energy ray-curable adhesive composition of the present invention, and a liquid crystal retardation film adjacent to the adhesive layer (1).

[0049] (adhesive layer) The adhesive layer (1) can be formed, for example, by applying an adhesive composition (1) to the surface on which the adhesive layer (1) is to be formed, and irradiating the coating with active energy rays to cure the adhesive composition (1). The method for applying and curing the adhesive composition (1) is not particularly limited, and can be appropriately selected from conventionally known methods for forming general active energy ray-curable adhesive layers.

[0050] The adhesive composition (1) can be applied by any known method, such as a coating method such as spin coating, extrusion, gravure coating, die coating, bar coating, or applicator method, or a printing method such as a flexographic method.

[0051] Examples of light sources for actinic rays include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, LED light sources emitting light in the wavelength range of 380 to 440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps.

[0052] The ultraviolet irradiation intensity is appropriately determined depending on the composition of the adhesive composition (1) and is not particularly limited, but is usually 10 to 3,000 mW / cm 2The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for activating the polymerization initiator. The light irradiation time is usually 0.1 seconds to 10 minutes, preferably 1 second to 5 minutes, more preferably 5 seconds to 3 minutes, and even more preferably 10 seconds to 1 minute. When irradiating once or multiple times with such ultraviolet irradiation intensity, the cumulative light amount is 10 to 3,000 mJ / cm. 2 , preferably 50 to 2,000 mJ / cm 2 , more preferably 100 to 1,000 mJ / cm 2 is.

[0053] The adhesive layer (1) formed from the adhesive composition (1) contains a structural unit derived from the urethane (meth)acrylate (a), a structural unit derived from the hydroxyl group-containing (meth)acrylate (b), a structural unit derived from the aromatic ring-containing (meth)acrylate (c), and a structural unit derived from the aromatic ring-containing (meth)acrylate (d), preferably in amounts or ratios corresponding to the blending amounts of each curable compound in the adhesive composition (1).

[0054] The thickness of the adhesive layer (1) is not particularly limited and can be appropriately determined depending on the configuration and use of the optical laminate. For example, from the viewpoint of thinning the optical laminate and ensuring adhesion, it is preferably 0.1 to 5 μm, more preferably 0.3 to 4 μm, and even more preferably 0.5 to 3 μm. The thickness of the adhesive layer (1) can be measured using a laser microscope, a film thickness meter, or the like. The same applies to the measurement of the thickness of each layer, such as the liquid crystal retardation film and the polarizing film, that constitute the optical laminate.

[0055] (Liquid crystal retardation film) The optical laminate of the present invention includes a liquid crystal retardation film adjacent to the adhesive layer (1). In the present invention, the liquid crystal retardation film preferably includes a cured liquid crystal film formed by aligning a polymerizable liquid crystal compound. The liquid crystal retardation film may consist of a single layer of the cured liquid crystal film or a combination of the cured liquid crystal film and an alignment film for forming the cured liquid crystal film. The cured liquid crystal film constituting the liquid crystal retardation film (hereinafter also referred to as a "cured liquid crystal retardation film") can be formed from a composition containing a polymerizable liquid crystal compound (hereinafter also referred to as a "composition for forming a retardation film"). A liquid crystal retardation film containing a cured liquid crystal film is preferable because it allows for a thin film and allows for the wavelength dispersion characteristics to be freely designed. However, the retardation value of the liquid crystal retardation film may decrease under high temperature conditions. In the optical laminate of the present invention, the liquid crystal retardation film is laminated adjacent to the adhesive layer (1), which is a cured layer of the adhesive composition (1) containing the specific curable compound. This effectively suppresses changes in the retardation value due to migration of aromatic ring-containing (meth)acrylate from the adhesive layer (1). When the liquid crystal retardation film is composed of a retardation liquid crystal cured film and an alignment film, the layer located on the adhesive layer (1) side may be either the retardation liquid crystal cured film or the alignment film. In one embodiment of the present invention, the alignment film is located on the adhesive layer (1) side.

[0056] A liquid crystal retardation film can usually be formed by applying a retardation film-forming composition onto an alignment film formed on a substrate and polymerizing a polymerizable liquid crystal compound (hereinafter also referred to as "polymerizable liquid crystal compound (1)") contained in the retardation film-forming composition. A retardation liquid crystal cured film is usually a film in which the polymerizable liquid crystal compound (1) is cured in an aligned state. In order for the optical laminate of the present invention to function as a circular polarizer, it is usually preferable that the liquid crystal retardation film contains a liquid crystal retardation film containing a "horizontally aligned liquid crystal cured film" in which the polymerizable liquid crystal compound is cured in a state in which it is aligned horizontally relative to the plane of the retardation film. In this case, if the polymerizable liquid crystal compound is a rod-shaped liquid crystal, a positive A plate is sufficient, and if the polymerizable liquid crystal compound is a discotic liquid crystal, a negative A plate is sufficient.

[0057] When the liquid crystal retardation film has a λ / 4 plate function (ie, a π / 2 retardation function) over the entire visible light range, it can achieve a high level of anti-reflection function.

[0058] The function of the λ / 4 plate over the entire visible light range preferably satisfies the optical characteristics shown in the following formula (1), where R(λ) is the in-plane retardation for light with a wavelength of λ nm, and more preferably satisfies the optical characteristics shown in the following formulas (1), (2), and (3): 100nm <Re(550)<160nm (1) (In the formula, Re(550) represents the in-plane phase difference value (in-plane retardation) for light with a wavelength of 550 nm.) Re(450) / Re(550)≦1.0 (2) 1.00≦Re(650) / Re(550) (3) (In the formula, Re(450) represents the in-plane retardation value for light with a wavelength of 450 nm, Re(550) represents the in-plane retardation value for light with a wavelength of 550 nm, and Re(650) represents the in-plane retardation value for light with a wavelength of 650 nm.) When the liquid crystal retardation film is composed of a retardation liquid crystal cured film and an alignment film, the in-plane retardation value of the liquid crystal retardation film is a value measured in a state where these two films are combined.

[0059] When the in-plane retardation value Re(550) of the liquid crystal retardation film falls within the range defined by formula (1), the retardation film functions as a λ / 4 wavelength plate, enhancing the effect of improving the front reflection hue (the effect of suppressing coloration) when a circular polarizer including the retardation film is applied to an organic electroluminescence (EL) display device or the like. Furthermore, when the liquid crystal retardation film satisfies formulas (2) and (3), the in-plane retardation value at short wavelengths is smaller than the in-plane retardation value at long wavelengths, i.e., exhibiting so-called reverse wavelength dispersion. An optical laminate (circular polarizer) having such a liquid crystal retardation film exhibits excellent light leakage suppression effect at short wavelengths and tends to exhibit excellent front reflection hue when incorporated into an organic electroluminescence (EL) display device or the like. From the viewpoint of improving the reverse wavelength dispersion and further enhancing the effect of improving the front reflection hue, Re(450) / Re(550) is 0.7 or more and 1.0 or less, more preferably 0.80 or more and 0.95 or less, even more preferably 0.80 or more and 0.92 or less, and particularly preferably 0.82 or more and 0.88 or less. Furthermore, Re(650) / Re(550) is preferably 1.01 or more, more preferably 1.02 or more, and these values ​​can be arbitrarily controlled by adjusting the mixing ratio of the polymerizable liquid crystal compound, the lamination angle of the multiple optically anisotropic layers, and the retardation value.

[0060] The in-plane retardation value can be adjusted by the film thickness d of the retardation liquid crystal cured film. The in-plane retardation value is determined by the formula Re(λ) = (nx(λ) - ny(λ)) × d (where nx(λ) represents the principal refractive index at a wavelength of λ nm in the plane of the liquid crystal retardation film, ny(λ) represents the refractive index at a wavelength of λ nm in the same plane as nx in a direction perpendicular to the direction of nx, and d represents the film thickness of the liquid crystal retardation film). Therefore, to obtain the desired in-plane retardation value (Re(λ): the in-plane retardation value of the retardation film at a wavelength of λ (nm)), it is sufficient to adjust the three-dimensional refractive index and the film thickness d.

[0061] In the optical laminate of the present invention, there may be one or two or more liquid crystal retardation films. Specifically, it preferably includes a liquid crystal retardation film having a λ / 4 wavelength plate function, particularly a liquid crystal retardation film having an inverse wavelength dispersion λ / 4 wavelength plate function, or preferably combines two or more types of liquid crystal retardation films with different orientations. For example, it may be a combination of a retardation film having a λ / 2 wavelength plate function (i.e., a retardation function of π) and a retardation film having a λ / 4 plate function (i.e., a retardation function of π / 2). Further, for example, in addition to a liquid crystal retardation film having a 1 / 4 wavelength plate function, it may include a liquid crystal retardation film that is a positive C plate (nx≈ny<nz). The liquid crystal retardation film that is a positive C plate is a "vertically aligned liquid crystal cured film" in which the polymerizable liquid crystal compound is cured in a state where it is aligned perpendicular to the plane of the retardation film. By combining and including a retardation film having a 1 / 4 wavelength plate function and a retardation film that is a positive C plate, when the optical laminate is applied to an organic EL display device or the like, improvement in the oblique reflection hue can be expected in addition to the improvement in the front reflection hue. Each liquid crystal retardation film may have a tilt alignment or may form a cholesteric alignment state. In addition, when the optical laminate includes two or more liquid crystal cured films, it is preferable that at least one liquid crystal cured film is present adjacent to the adhesive layer (1), more preferably a liquid crystal retardation film that is a horizontally aligned liquid crystal cured film is present adjacent to the adhesive layer (1), and even more preferably a liquid crystal retardation film having a λ / 4 wavelength plate function is present adjacent to the adhesive layer (1). Further, when the optical laminate includes a polarizing film, it is preferable that the liquid crystal retardation film closest to the polarizing film side is present adjacent to the adhesive layer (1) on the polarizing film side. In these embodiments, the adhesive layer for laminating the liquid crystal retardation films other than the liquid crystal retardation film adjacent to the adhesive layer (1) to other layers may be an adhesive layer formed from the adhesive composition (1), or may be an adhesive layer formed from an adhesive different from this or a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive.

[0062] The polymerizable liquid crystal compound (1) capable of forming the retardation film in the present invention can be appropriately selected from polymerizable liquid crystal compounds conventionally known in the field of retardation films, depending on the desired optical properties. The polymerizable liquid crystal compound (1) usable in the present invention can be classified, for example, based on its shape, into a rod-shaped type (rod-shaped liquid crystal compound) and a discotic type (discotic liquid crystal compound, discotic liquid crystal compound), and any liquid crystal compound can be used. Furthermore, a mixture of two or more rod-shaped liquid crystal compounds, two or more discotic liquid crystal compounds, or a mixture of a rod-shaped liquid crystal compound and a discotic liquid crystal compound may be used.

[0063] The polymerizable liquid crystal compound (1) is a liquid crystal compound having a polymerizable group. The polymerizable liquid crystal compound (1) is generally a polymer obtained by polymerizing the polymerizable liquid crystal compound alone in a state aligned in a specific direction, and the resulting polymer (cured product) may be a polymerizable liquid crystal compound exhibiting positive wavelength dispersion or a polymerizable liquid crystal compound exhibiting reverse wavelength dispersion. In the present invention, only one type of polymerizable liquid crystal compound may be used, or both types of polymerizable liquid crystal compounds may be used in combination. For example, when an optical laminate includes a retardation film having a λ / 4 waveplate function and a retardation film serving as a positive C plate, the polymerizable liquid crystal compounds constituting these may be the same or different.

[0064] In the present invention, the polymerizable group possessed by the polymerizable liquid crystal compound (1) forming the retardation film is preferably a photopolymerizable group. The photopolymerizable group refers to a group that can participate in a polymerization reaction by reactive species, such as active radicals or acids, generated from a photopolymerization initiator. Examples of the photopolymerizable group include vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, oxiranyl, and oxetanyl groups. Among these, acryloyloxy, methacryloyloxy, vinyloxy, oxiranyl, and oxetanyl groups are preferred, with acryloyloxy groups being more preferred. The liquid crystal property may be either thermotropic or lyotropic, but thermotropic liquid crystals are preferred because of the ability to precisely control the film thickness. Furthermore, the phase order structure of the thermotropic liquid crystal may be either nematic or smectic. The polymerizable liquid crystal compound (1) may be used alone or in combination of two or more.

[0065] The polymerizable liquid crystal compound (1) preferably contains a polymerizable liquid crystal compound having a T-shaped or H-shaped mesogenic structure that has additional birefringence in a direction perpendicular to the molecular long axis direction, from the viewpoint of exhibiting reverse wavelength dispersion, and more preferably contains a T-shaped polymerizable liquid crystal compound from the viewpoint of obtaining stronger dispersion.

[0066] Specific examples of the polymerizable liquid crystal compound having a T-shaped liquid crystal structure include those represented by the following formula (X): [ka] (hereinafter, also referred to as "polymerizable liquid crystal compound (X)").

[0067] In formula (X), Ar represents a divalent aromatic group which may have a substituent. The divalent aromatic group preferably contains at least one of a nitrogen atom, an oxygen atom, and a sulfur atom. When the divalent group Ar contains two or more aromatic groups, the two or more aromatic groups may be bonded to each other via a divalent bonding group such as a single bond, -CO-O-, or -O-. G 1 and G 2 each independently represents a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein a hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group, and a carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom. L 1 , L 2 、 B 1 and B 2 are each independently a single bond or a divalent linking group. k and l each independently represent an integer of 0 to 3, and satisfy the relationship 1≦k+l. When 2≦k+l, B 1 and B 2 , G 1 and G 2 may be the same as or different from each other. E 1 and E 2 each independently represents an alkanediyl group having 1 to 17 carbon atoms, wherein a hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and wherein a -CH2- contained in the alkanediyl group may be substituted with -O-, -S-, or -COO-, and when there are a plurality of -O-, -S-, or -COO-, they are not adjacent to each other. 1 and P 2 each independently represents a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.

[0068] G 1 and G 2are each independently preferably a 1,4-phenylenediyl group optionally substituted with at least one substituent selected from the group consisting of halogen atoms and alkyl groups having 1 to 4 carbon atoms, or a 1,4-cyclohexanediyl group optionally substituted with at least one substituent selected from the group consisting of halogen atoms and alkyl groups having 1 to 4 carbon atoms, more preferably a 1,4-phenylenediyl group substituted with a methyl group, an unsubstituted 1,4-phenylenediyl group, or an unsubstituted 1,4-trans-cyclohexanediyl group, and particularly preferably an unsubstituted 1,4-phenylenediyl group or an unsubstituted 1,4-trans-cyclohexanediyl group. Also, there are multiple G 1 and G 2 At least one of L is preferably a divalent alicyclic hydrocarbon group. 1 or L 2 G binds to 1 and G 2 It is more preferable that at least one of the groups is a divalent alicyclic hydrocarbon group.

[0069] L 1 and L 2 are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a1 OR a2 -, -R a3 COOR a4 -, -R a5 OCOR a6 -, -R a7 OC=OOR a8 -, -N=N-, -CR c =CR d -, or -C≡C-, where R a1 ~R a8 each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms, and R c and R d represents an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. 1 and L 2 are each independently preferably a single bond, -OR a2-1 -, -CH2-, -CH2CH2-, -COORa4-1 -, or -OCOR a6-1 -, where R a2-1 , R a4-1 , R a6-1 Each independently represents a single bond, -CH2-, or -CH2CH2-. 1 and L 2 are each independently more preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, or -OCO-.

[0070] B 1 and B 2 are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a9 OR a10 -, -R a11 COOR a12 -, -R a13 OCOR a14 -, or -R a15 OC=OOR a16 -, where R a9 ~R a16 each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms. 1 and B 2 are each independently preferably a single bond, -OR a10-1 -, -CH2-, -CH2CH2-, -COOR a12-1 -, or -OCOR a14-1 -, where R a10-1 , R a12-1 , R a14-1 Each independently represents a single bond, -CH2-, or -CH2CH2-. B 1 and B 2 are each independently more preferably a single bond, -O-, -CH2CH2-, -COO-, -COOCH2CH2-, -OCO-, or -OCOCH2CH2-.

[0071] From the viewpoint of exhibiting reverse wavelength dispersion, k and l are preferably in the range of 2≦k+l≦6, preferably k+l=4, and more preferably k=2 and l=2. When k=2 and l=2, a symmetric structure is obtained, which is preferable.

[0072] E 1 and E 2 are each independently preferably an alkanediyl group having 1 to 17 carbon atoms, more preferably an alkanediyl group having 4 to 12 carbon atoms.

[0073] P 1 or P 2 Examples of the polymerizable group represented by the formula (I) include an epoxy group, a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group. Among these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferred, and an acryloyloxy group is more preferred.

[0074] Ar preferably has at least one selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, and an electron-withdrawing group. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring, with a benzene ring and a naphthalene ring being preferred. Examples of the aromatic heterocyclic ring include a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazole ring, a triazine ring, a pyrroline ring, an imidazole ring, a pyrazole ring, a thiazole ring, a benzothiazole ring, a thienothiazole ring, an oxazole ring, a benzoxazole ring, and a phenanthroline ring. Among these, a thiazole ring, a benzothiazole ring, or a benzofuran ring is preferred, and a benzothiazole group is even more preferred. Furthermore, when Ar contains a nitrogen atom, it is preferred that the nitrogen atom has π electrons.

[0075] In formula (X), the total number of π electrons contained in the divalent aromatic group represented by Ar is N πis preferably 8 or more, more preferably 10 or more, even more preferably 14 or more, and particularly preferably 16 or more. It is also preferably 30 or less, more preferably 26 or less, and even more preferably 24 or less.

[0076] Suitable examples of the aromatic group represented by Ar include the following groups:

[0077] [ka]

[0078] In formulas (Ar-1) to (Ar-23), * represents a linking portion, and Z 0 , Z 1 and Z 2 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, an alkylsulfonyl group having 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, an N-alkylamino group having 1 to 12 carbon atoms, an N,N-dialkylamino group having 2 to 12 carbon atoms, an N-alkylsulfamoyl group having 1 to 12 carbon atoms, or an N,N-dialkylsulfamoyl group having 2 to 12 carbon atoms.

[0079] Q 1 , and Q 2 are each independently -CR 2’ R 3’ -, -S-, -NH-, -NR 2’ represents -, -CO- or -O-, and R 2’ and R 3’ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0080] J 1 , and J. 2 each independently represents a carbon atom or a nitrogen atom.

[0081] Y 1 , and Y2 each independently represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group.

[0082] W 1 and W 2 each independently represents a hydrogen atom, a cyano group, a methyl group or a halogen atom; and m represents an integer of 0 to 6.

[0083] Y 1 , and Y 2 Examples of the aromatic hydrocarbon group in the formula (I) include aromatic hydrocarbon groups having 6 to 20 carbon atoms, such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, and a biphenyl group, with a phenyl group and a naphthyl group being preferred, and a phenyl group being more preferred. Examples of the aromatic heterocyclic group include aromatic heterocyclic groups having 4 to 20 carbon atoms and containing at least one heteroatom, such as a nitrogen atom, an oxygen atom, or a sulfur atom, such as a furyl group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group, and a benzothiazolyl group being preferred.

[0084] Y 1 , and Y 2 may each independently be an optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group. The polycyclic aromatic hydrocarbon group refers to a fused polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. The polycyclic aromatic heterocyclic group refers to a fused polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

[0085] Z 0 , Z 1 and Z 2 are each independently preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms, and Z 0 is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, and Z 1 and Z 2 is more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.

[0086] Q 1 , and Q 2 -NH-, -S-, -NR 2’ -, -O- are preferred, and R 2’ is preferably a hydrogen atom, and among these, -S-, -O-, and -NH- are particularly preferred.

[0087] Among the formulae (Ar-1) to (Ar-23), the formulae (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability. In formulas (Ar-17) to (Ar-23), Y 1 is the nitrogen atom to which it is bonded and Z 0 and Y may form an aromatic heterocyclic group together. Examples of the aromatic heterocyclic group include those mentioned above as aromatic heterocycles that Ar may have, such as a pyrrole ring, an imidazole ring, a pyrroline ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, an indole ring, a quinoline ring, an isoquinoline ring, a purine ring, and a pyrrolidine ring. This aromatic heterocyclic group may have a substituent. In addition, Y 1 is the nitrogen atom to which it is bonded and Z 0 and may be the above-mentioned optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group, such as a benzofuran ring, a benzothiazole ring, or a benzoxazole ring.

[0088] In one embodiment of the present invention, the polymerizable liquid crystal compound (X) is preferably a compound having a maximum absorption wavelength of 300 to 400 nm. A maximum absorption wavelength within the above range is advantageous in terms of the stability of the retardation film-forming composition, and can improve the alignment and thickness uniformity of the obtained retardation liquid crystal cured film. The maximum absorption wavelength of the polymerizable liquid crystal compound (X) can be measured in a solvent using a UV-visible spectrophotometer. The solvent is one that can dissolve the polymerizable liquid crystal compound (X), such as chloroform.

[0089] The polymerizable liquid crystal compound (X) can be produced, for example, according to the method described in JP-A-2010-31223.

[0090] In the present invention, as the polymerizable liquid crystal compound (1) forming the liquid crystal retardation film, in addition to or separately from the polymerizable liquid crystal compound (X), for example, polymerizable liquid crystal compounds such as those described in JP-A Nos. 2010-31223, 2010-270108, 2011-6360, and 2011-207765, polymerizable liquid crystal compounds exhibiting so-called positive wavelength dispersion, and the polymerizable liquid crystal compound (Y) described below may be used. All of these polymerizable liquid crystal compounds can be used by horizontal alignment or vertical alignment.

[0091] The content of the polymerizable liquid crystal compound (1) in the composition for forming a retardation film can be appropriately determined depending on the optical properties of the desired optical laminate, the type of polymerizable liquid crystal compound (1) used, etc. The content of the polymerizable liquid crystal compound (1) in the composition for forming a retardation film is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass, relative to 100 parts by mass of the solid content of the composition for forming a retardation film. If the content of the polymerizable liquid crystal compound (1) is within the above range, it is advantageous from the viewpoint of the alignment of the obtained retardation liquid crystal cured film.

[0092] The retardation film-forming composition may contain additives such as a polymerization initiator, a solvent, and a leveling agent in addition to the polymerizable liquid crystal compound. As the polymerization initiator, a photopolymerization initiator that generates active radicals or acids by the action of light is preferred, as it can initiate a polymerization reaction under lower temperature conditions, and a photopolymerization initiator that generates radicals by the action of light is more preferred. The polymerization initiators may be used alone or in combination of two or more.

[0093] As the photopolymerization initiator, a known photopolymerization initiator can be used. For example, as a photopolymerization initiator that generates an active radical, the same ones as those exemplified above as those that can be used in the adhesive composition (1) can be used. The photopolymerization initiator can be appropriately selected in relation to the polymerizable liquid crystal compound that forms the retardation film.

[0094] The content of the polymerization initiator is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, even more preferably 0.5 to 10 parts by mass, and particularly preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound (1). When the content of the polymerization initiator is within the above range, the polymerization reaction can be carried out without significantly disturbing the alignment of the polymerizable liquid crystal compound.

[0095] The solvent may be appropriately selected depending on the solubility of the polymerizable liquid crystal compound to be used, and is preferably a solvent that can completely dissolve the above components and is inactive to the polymerization reaction.

[0096] Specific examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate, and ethyl lactate; and acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone. Examples of suitable solvents include ketone solvents, aliphatic hydrocarbon solvents such as pentane, hexane, and heptane, aromatic hydrocarbon solvents such as toluene and xylene, nitrile solvents such as acetonitrile, ether solvents such as tetrahydrofuran and dimethoxyethane, chlorine-containing solvents such as chloroform and chlorobenzene, amide solvents such as N,N-dimethylacetamide and N,N-dimethylformamide, sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide, and sulfolane, carbonate solvents such as ethylene carbonate and propylene carbonate, and pyrrolidone solvents such as N-methylpyrrolidone. These solvents may be used alone or in combination of two or more.

[0097] The content of the solvent is preferably 100 to 1900 parts by mass, more preferably 150 to 1000 parts by mass, and even more preferably 180 to 800 parts by mass, relative to 100 parts by mass of the solid content of the retardation film-forming composition.

[0098] The retardation film-forming composition may contain a leveling agent. The leveling agent adjusts the fluidity of the retardation film-forming composition and functions to make the coating film obtained by applying the composition flatter. Specific examples include surfactants. The leveling agent is preferably at least one selected from the group consisting of leveling agents containing a polyacrylate compound as a main component and leveling agents containing a fluorine atom-containing compound as a main component. The leveling agents can be used alone or in combination of two or more.

[0099] Examples of leveling agents containing polyacrylate compounds as their main components include BYK-350, BYK-352, BYK-353, BYK-354, BYK-355, BYK-358N, BYK-361N, BYK-380, BYK-381, and BYK-392 (BYK Chemie).

[0100] Examples of leveling agents containing a fluorine atom-containing compound as a main component include Megafac (registered trademark) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F-470, F-471, F-477, F-479, F-482, F-483, and F-556 (DIC Corporation); Surflon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, and SA-100 (AGC Seimi Chemical Co., Ltd.); E1830, E5844 (Daikin Fine Chemical Research Institute, Inc.); F-top EF301, F-top EF303, F-top EF351, and F-top EF352 (Mitsubishi Materials Electronic Chemicals Co., Ltd.).

[0101] When the composition for forming a retardation film contains a leveling agent, the content thereof is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound (1). When the content of the leveling agent is within the above range, the polymerizable liquid crystal compound (1) is easily aligned, unevenness is less likely to occur, and a smoother retardation film tends to be obtained.

[0102] The retardation film-forming composition may contain additives other than the leveling agent. Examples of the additives include ionic compounds, polymerizable non-liquid crystal compounds, photosensitizers, antioxidants, release agents, stabilizers, colorants such as bluing agents, flame retardants, and lubricants. When the retardation film-forming composition contains other additives, the content of the additives is preferably more than 0% and not more than 20% by mass, more preferably more than 0% and not more than 10% by mass, based on the solid content of the polarizing film-forming composition.

[0103] The composition for forming a retardation film can be produced by a conventionally known method for preparing a liquid crystal composition, and can usually be prepared by mixing and stirring the polymerizable liquid crystal compound (1), and, if necessary, a polymerization initiator, a solvent, the above-mentioned additives, etc.

[0104] The thickness of the liquid crystal retardation film can be appropriately selected depending on the display device to which it is applied. In one embodiment of the present invention, the thickness of the liquid crystal retardation film is preferably 0.5 μm to 5 μm, more preferably 1 μm to 3 μm. When the liquid crystal retardation film is composed of a retardation liquid crystal cured film and an alignment film, the thickness of the liquid crystal retardation film is the thickness of only the retardation liquid crystal cured film.

[0105] In the present invention, the retardation liquid crystal cured film can be formed on an alignment film. The alignment film for forming the retardation liquid crystal cured film has an alignment regulating force for aligning the polymerizable liquid crystal compound (1) in a desired direction, and a precisely aligned retardation liquid crystal cured film can be easily obtained by applying a retardation film-forming composition onto the alignment film. The alignment film preferably has solvent resistance such that it does not dissolve the retardation film-forming composition when applied, and also has heat resistance to remove the solvent and to heat treatment for aligning the polymerizable liquid crystal compound.

[0106] Examples of the alignment film include an alignment film containing an orientable polymer, a photo-alignment film, a groove alignment film having a concave-convex pattern or a plurality of grooves on the surface, a stretched film stretched in the alignment direction, etc. These various alignment films can be appropriately selected from those conventionally known in the art according to the desired alignment control force.

[0107] In one embodiment of the present invention, from the viewpoint of easily improving alignment accuracy and adhesion to a retardation liquid crystal cured film formed from a retardation film-forming composition, it is preferable that the liquid crystal retardation film includes a photo-alignment film, i.e., a liquid crystal cured film is formed on a photo-alignment film. The photo-alignment film is also advantageous in that the direction of the alignment restraint force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light.

[0108] Photo-alignment films are typically obtained by applying a composition containing a polymer, oligomer, or monomer having a photoreactive group and a solvent (hereinafter also referred to as a "photo-alignment film-forming composition") to a substrate or the like and then irradiating the coated surface with polarized light (preferably polarized UV). The photoreactive group refers to a group that exhibits liquid crystal alignment ability upon irradiation with light. Specific examples include groups that are involved in photoreactions that induce molecular alignment upon irradiation or that are the origin of liquid crystal alignment ability, such as isomerization, dimerization, photocrosslinking, or photodecomposition. Among these, groups that participate in dimerization or photocrosslinking are preferred because of their excellent alignment properties. As the photoreactive group, groups having an unsaturated bond, particularly a double bond, are preferred, and groups having at least one bond selected from the group consisting of a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond), and a carbon-oxygen double bond (C=O bond) are particularly preferred.

[0109] Specific examples of such alignment films include photo-alignment films such as those described in JP 2021-196514 A and WO 2018 / 003416 A.

[0110] The thickness of the alignment film is usually 10 to 5000 nm, preferably 10 to 1000 nm, more preferably 10 to 500 nm, still more preferably 10 to 300 nm, and particularly preferably 30 to 300 nm. When the thickness of the alignment film is within the above range, the alignment film can exhibit good adhesion at the interface with a cured layer formed from the polymerizable liquid crystal compound (1) formed on the alignment film, while exhibiting alignment regularity, and can form a liquid crystal retardation film with high alignment order.

[0111] The liquid crystal retardation film can be produced by, for example, forming a coating film of a retardation film-forming composition, removing the solvent from the coating; raising the temperature to a temperature at which the polymerizable liquid crystal compound (1) undergoes a phase transition to a liquid phase or higher, and then lowering the temperature to cause the polymerizable liquid crystal compound (1) to undergo a phase transition to a liquid crystal phase; and Polymerizing the polymerizable liquid crystal compound (1) while maintaining the liquid crystal phase. It can be produced by a method comprising:

[0112] The formation of a coating film of the retardation film-forming composition can be carried out, for example, by applying the composition onto a substrate or an alignment film. The substrate can be a layer constituting the optical laminate of the present invention, but in one embodiment of the present invention, it is preferable that it is finally peeled off. As the substrate, a resin film substrate or the like conventionally known in the field of optical films can be used. Examples of resins constituting such resin films include polyolefin-based resins such as polyethylene and polypropylene; cycloolefin-based resins such as norbornene-based polymers; polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate; poly(meth)acrylic acid-based resins such as (meth)acrylic acid and polymethyl(meth)acrylate; cellulose ester-based resins such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; vinyl alcohol-based resins such as polyvinyl alcohol and polyvinyl acetate; polycarbonate-based resins; polystyrene-based resins; polyarylate-based resins; polysulfone-based resins; polyethersulfone-based resins; polyamide-based resins; polyimide-based resins; polyether ketone-based resins; polyphenylene sulfide-based resins; polyphenylene oxide-based resins, and mixtures thereof. These may be used alone or in combination of two or more. Such resins can be formed into a film by known means such as solvent casting or melt extrusion to form a resin film substrate. Commercially available products may also be used as the film substrate or the resin constituting the film substrate.

[0113] The film substrate may be subjected to a surface treatment such as corona treatment or plasma treatment, and may also be subjected to a release treatment if the substrate is to be peeled off later. The thickness of the substrate is not particularly limited and may be appropriately selected within a practical range. For example, it may be about 5 to 300 μm.

[0114] The method for applying the retardation film-forming composition is not particularly limited, and the same methods as those exemplified above for applying the adhesive composition (1) can be used.

[0115] When the retardation film-forming composition contains a solvent, the solvent is usually removed from the applied composition. Examples of methods for removing the solvent include natural drying, forced air drying, heat drying, and reduced-pressure drying. The dried film is preferably dried so that the residual solvent in the liquid crystal retardation film is 1% by weight or less relative to the total mass of the retardation film. The amount of residual solvent can be determined by peeling the liquid crystal retardation film from the substrate, weighing it, immersing the retardation film in a solvent that dissolves the retardation film, such as tetrahydrofuran, irradiating it with ultrasound for about 10 minutes to extract the dissolved components, and then analyzing the solution by gas chromatography. Conditions such as the drying temperature and drying time can be appropriately determined depending on the composition of the retardation film-forming composition, the materials of the substrate and alignment film, and the like.

[0116] The polymerizable liquid crystal compound (1) in the coating film is usually heated to a temperature at which it transitions to a liquid crystal state or a solution state or higher, and then cooled to a temperature at which the liquid crystal is aligned, thereby aligning and forming a liquid crystal phase. The temperature at which the polymerizable liquid crystal compound (1) in the coating film is aligned can be determined in advance by, for example, observing the texture of a composition containing the polymerizable liquid crystal compound (1). Alternatively, the removal of the solvent and the alignment of the liquid crystal may be carried out simultaneously. The temperature at this time varies depending on the type of solvent to be removed and the type of polymerizable liquid crystal compound used, but is preferably in the range of 50 to 200°C, more preferably 80 to 130°C.

[0117] A retardation liquid crystal cured film is formed as a cured product layer of the liquid crystal composition by polymerizing and curing the polymerizable liquid crystal compound (1) while maintaining the liquid crystal state of the polymerizable liquid crystal compound (1). Photopolymerization is preferred as the polymerization method. In photopolymerization, the light irradiated onto the dried film is appropriately selected depending on the type of polymerizable liquid crystal compound contained in the dried film (particularly the type of polymerizable group possessed by the polymerizable liquid crystal compound), the type and amount of polymerization initiator, etc.

[0118] The conditions such as the light source of the active energy rays and the ultraviolet irradiation intensity are appropriately determined depending on the composition of the retardation film-forming composition, etc., and are not particularly limited. For example, the same light source, irradiation conditions, etc. as those exemplified above in the method for producing the adhesive layer (1) can be used.

[0119] (Hard coat layer) The optical laminate of the present invention may have a hard coat layer on the side of the adhesive layer (1) opposite to the liquid crystal retardation film. When the hard coat layer is disposed on the side of the adhesive layer (1) opposite to the liquid crystal retardation film, the hard coat layer is preferably adjacent to the adhesive layer (1).

[0120] In one embodiment of the present invention, the hard coat layer is preferably formed from a curable composition containing an active energy ray-curable component. Examples of curable compositions that can form the hard coat layer include cationic polymerization compositions containing a cationic polymerizable compound as the curable compound, radical polymerization compositions containing a radical polymerizable compound as the curable compound, and hybrid compositions containing both a cationic polymerizable compound and a radical polymerizable compound. Among these, cationic polymerization active energy ray-curable compositions containing a cationic polymerizable compound and a photocationic polymerization initiator, and radical polymerization active energy ray-curable compositions containing a radical polymerizable compound and a photoradical polymerization initiator are preferred. In particular, when both the adhesive layer (1) and the hard coat layer contain a (meth)acrylic compound, the refractive index difference between the hard coat layer and the adhesive layer (1) is easily controlled, resulting in excellent suppression of light reflection at their interface. Furthermore, adhesion between these layers can be improved. Specific examples of cationic polymerization compounds include epoxy compounds having one or more epoxy groups in the molecule, oxetane compounds having one or more oxetane rings in the molecule, vinyl compounds, and the like. Specific examples of the radical polymerizable compound include a (meth)acrylic compound having one or more (meth)acryloyl groups in the molecule, a vinyl compound, etc. The curable composition may contain one or more cationic polymerizable compounds and / or one or more radical polymerizable compounds.

[0121] The hard coat layer can be formed by the same method as described for forming the adhesive layer (1).

[0122] The thickness of the hard coat layer is preferably 0.1 to 5 μm, more preferably 0.5 to 5 μm, and even more preferably 1.0 to 3 μm.

[0123] When the optical laminate of the present invention includes a hard coat layer between the polarizing film and the adhesive layer (1), the in-plane average refractive index of the hard coat layer (hereinafter also simply referred to as "refractive index n1"), the in-plane average refractive index of the liquid crystal retardation film (hereinafter also simply referred to as "refractive index n2"), and the in-plane average refractive index of the adhesive layer (1) (hereinafter also simply referred to as "refractive index n3") satisfy the following formula: |(n1×n2) 1 / 2 -n3| ≦ 0.018 It is preferable that the following relationship is satisfied. When the in-plane average refractive indexes of these three layers satisfy the above relationship, it is expected that the effect of suppressing light reflection at the interface between two adjacent layers can be achieved. As a result, when the obtained optical laminate is incorporated into a display device, it is possible to effectively suppress light reflection between each layer of external light that is taken in. In order to further enhance this effect, |(n1×n2) 1 / 2 The value of -n3| is more preferably 0.015 or less, further preferably 0.013 or less, particularly preferably 0.010 or less, and is preferably 0.0001 or more, more preferably 0.001 or more.

[0124] In the present invention, the in-plane average refractive index n3 of the adhesive layer (1) is preferably 1.50 to 1.60, more preferably 1.52 to 1.58, and even more preferably 1.54 to 1.56. When the in-plane average refractive index of the adhesive layer (1) is within the above range, light reflection at the interface between the hard coat layer and the adhesive layer (1) can be suppressed. Furthermore, light reflection at the interface between the adhesive layer (1) and the liquid crystal retardation film can also be easily suppressed. As a result, when the obtained optical laminate is incorporated into a display device, it is highly effective in suppressing light reflection between two adjacent layers. The in-plane average refractive index of the adhesive layer (1) can be controlled by the types and combinations of components that make up the adhesive layer (1).

[0125] In the present invention, the in-plane average refractive index of the adhesive layer (1) is a refractive index at a wavelength of 589 nm, and can be measured using an Abbe refractometer or the like. Specifically, it can be measured, for example, according to the method described in the Examples below. The in-plane average refractive index of each hard coat layer described below can also be measured in the same way.

[0126] In one embodiment of the present invention, the in-plane average refractive index n1 of the hard coat layer is, for example, preferably 1.30 to 1.60, more preferably 1.40 to 1.55. When the in-plane refractive index of the hard coat layer is within the above range, the light reflection suppression effect at the interface with the adhesive layer (1) is easily enhanced. The in-plane average refractive index of the hard coat layer can be controlled by the types and combinations of components constituting the hard coat layer, etc.

[0127] In one embodiment of the present invention, the in-plane average refractive index n2 of the liquid crystal retardation film adjacent to the adhesive layer (1) is, for example, preferably 1.50 to 1.70, more preferably 1.50 to 1.60. When the in-plane refractive index of the liquid crystal retardation film is within the above range, the light reflection suppression effect at the interface with the adhesive layer (1) is easily enhanced. The in-plane average refractive index of the liquid crystal retardation film can be controlled by the types and combinations of components constituting the liquid crystal retardation film. The in-plane average refractive index of the liquid crystal retardation film is the refractive index at a wavelength of 589 nm and can be measured using a polarization measurement device such as KOBRA-WR (manufactured by Oji Scientific Instruments Co., Ltd.). When the liquid crystal retardation film is composed of a retardation liquid crystal cured film and an alignment film, the in-plane average refractive index of the liquid crystal retardation film is a value measured when these two films are combined.

[0128] In one embodiment of the present invention, it is advantageous to control the difference (absolute value difference: |n3-n1|) between the in-plane average refractive index n3 of the adhesive layer (1) and the in-plane average refractive index n1 of the hard coat layer so that it is preferably 0.25 or less, more preferably 0.15 or less. When the difference between the refractive index n3 of the adhesive layer (1) and the refractive index n1 of the hard coat layer is equal to or less than the upper limit, an effect of suppressing light reflection at the interface between these two layers can be expected. From the viewpoint of obtaining an excellent reflection suppression effect, the smaller the difference, the better, and ideally it is 0.

[0129] In one embodiment of the present invention, it is advantageous to control the difference (absolute value difference: |n3-n2|) between the in-plane average refractive index n3 of the adhesive layer (1) and the in-plane average refractive index n2 of the liquid crystal retardation film so that it is preferably 0.15 or less, more preferably 0.05 or less. When the difference between the refractive index n3 of the adhesive layer (1) and the refractive index n2 of the liquid crystal retardation film is equal to or less than the upper limit, it is possible to expect an effect of suppressing light reflection at the interface between these two layers. From the viewpoint of obtaining an excellent reflection suppression effect, the smaller the difference, the better, and ideally it is 0.

[0130] In one embodiment of the present invention, it is preferable that the refractive index difference between the hard coat layer and the adhesive layer (1) (hereinafter also referred to as the "refractive index difference Δn1") and the refractive index difference between the adhesive layer (1) and the liquid crystal cured film (hereinafter also referred to as the "refractive index difference Δn2") are both not more than the above-mentioned upper limit. When these refractive index differences are both not more than the above-mentioned upper limit, mutual interference between light reflection at the interface between the hard coat layer and the adhesive layer (1) and light reflection at the interface between the adhesive layer (1) and the liquid crystal retardation film is unlikely to occur, and the light reflection suppression effect can be further improved. In one embodiment of the present invention, the difference between the refractive index difference Δn1 and the refractive index difference Δn2 (absolute value difference: |Δn1-Δn2|) is preferably not more than 0.05, more preferably not more than 0.03.

[0131] The refractive indexes n1, n2, and n3, as well as the difference between them, can be controlled by appropriately selecting the compositions of the hard coat layer, adhesive layer (1), and liquid crystal retardation film, particularly the types of compounds constituting each of these layers, their combinations, the alignment state of the liquid crystal retardation film, etc. In particular, by adjusting the refractive indexes of the adhesive layer (1) and the hard coat layer, which do not have optical absorption anisotropy, to approximate the in-plane average refractive index in the transmission axis direction of the liquid crystal retardation film, it is possible to effectively suppress light reflection occurring at the interface between the hard coat layer and adhesive layer (1) and at the interface between the adhesive layer (1) and the liquid crystal retardation film while ensuring the high optical properties required of the retardation film.

[0132] (polarizing film) The optical laminate of the present invention may include a polarizing film. In one embodiment of the present invention, the optical laminate of the present invention includes a polarizing film on the side of the hard coat layer opposite to the adhesive layer (1). In this case, the polarizing film and the hard coat layer may be adjacent to each other, or may be laminated via, for example, an alignment film or the like for forming the polarizing film.

[0133] In one embodiment of the present invention, the polarizing film constituting the optical laminate of the present invention is a cured layer of a polymerizable liquid crystal composition (hereinafter also referred to as a "polarizing film-forming composition") containing a polymerizable liquid crystal compound and a dichroic dye. When the polarizing film is a cured layer of the polarizing film-forming composition, it can be combined with a retardation film to be used in an organic EL display device as a circular polarizer with anti-reflection properties, thereby imparting high visibility. When the optical laminate of the present invention functions as a circular polarizer, the polarizing film is typically a horizontal polarizing film formed by curing the polymerizable liquid crystal compound and the dichroic dye in a state where they are oriented horizontally relative to the plane of the polarizing film. Such a horizontal polarizing film typically transmits light vibrating in the direction of its transmission axis but blocks polarized light vibrating perpendicularly to that direction, functioning as a polarizing film that extracts linearly polarized light from incident natural light.

[0134] The polymerizable liquid crystal compound (hereinafter also referred to as "polymerizable liquid crystal compound (2)") contained in the composition for forming a polarizing film in the present invention is a compound having at least one polymerizable group and having liquid crystal properties. The polymerizable group is preferably a photopolymerizable group, and examples thereof include the same polymerizable groups as those exemplified as the polymerizable groups contained in the polymerizable liquid crystal compound (1) that can constitute a liquid crystal retardation film. Among these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are more preferred, and an acryloyloxy group or a methacryloyloxy group is even more preferred.

[0135] In the present invention, the polymerizable liquid crystal compound (2) forming the polarizing film is preferably a liquid crystal compound exhibiting a smectic liquid crystal phase. By using a polymerizable liquid crystal compound exhibiting a smectic liquid crystal phase, a polarizing film having a high degree of orientational order and excellent polarizing properties can be formed. From the viewpoint of achieving a higher degree of orientational order, the liquid crystal state exhibited by the polymerizable liquid crystal compound is more preferably a high-order smectic phase (high-order smectic liquid crystal state). Here, the high-order smectic phase refers to a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, or a smectic L phase. Among these, the smectic B phase, the smectic F phase, and the smectic I phase are more preferred. The liquid crystal may be either a thermotropic or lyotropic liquid crystal, but a thermotropic liquid crystal is preferred because it allows precise control of the film thickness. The polymerizable liquid crystal compound may be a monomer, or may be an oligomer or polymer in which a polymerizable group is polymerized.

[0136] An example of such a polymerizable liquid crystal compound is a compound represented by formula (Y) (hereinafter also referred to as "polymerizable liquid crystal compound (Y)"). U 1 -V 1 -W 1 -(X 1 -Y 1 ) n -X 2 -W 2 -V 2 -U 2 (Y)

[0137] In formula (Y), X 1 and X 2are each independently a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein a hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with a substituent selected from the group consisting of 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, and a nitro group, and a carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom, provided that X 1 and X 2 At least one of the groups is a 1,4-phenylene group which may have the above-mentioned substituents, or a cyclohexane-1,4-diyl group which may have the above-mentioned substituents. Y 1 is a single bond or a divalent linking group. n is 1 to 3, and when n is 2 or more, multiple X 1 may be the same or different. 2 Multiple X 1 In addition, when n is 2 or more, a plurality of Y 1 may be the same or different. From the viewpoint of liquid crystal properties, n is preferably 2 or more. U 1 represents a hydrogen atom or a polymerizable group. U 2 represents a polymerizable group. W 1 and W 2 are each independently a single bond or a divalent linking group. V 1 and V 2 represent, independently of each other, an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH2- constituting the alkanediyl group may be replaced by -O-, -CO-, -S- or -NH-.

[0138] In the polymerizable liquid crystal compound (Y), X 1 and X 2are each independently preferably an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group, and X 1 and X 2 At least one of these is an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group, preferably a trans-cyclohexane-1,4-diyl group. The optionally substituted 1,4-phenylene group or the optionally substituted cyclohexane-1,4-diyl group may optionally have a substituent, such as an alkyl group having 1 to 4 carbon atoms, a cyano group, or a halogen atom, such as a chlorine atom or a fluorine atom. Preferably, the group is unsubstituted.

[0139] The polymerizable liquid crystal compound (Y) is a compound represented by the formula (Y1): -(X 1 -Y 1 ) n -X 2 - (Y1) [In the formula, X 1 , Y 1 , X 2 and n have the same meanings as above.] [hereinafter referred to as partial structure (Y1)] is preferably an asymmetric structure, since this facilitates the development of smectic liquid crystal properties. Examples of the polymerizable liquid crystal compound (2) in which the partial structure (Y1) has an asymmetric structure include: n is 1 and one X 1 and X 2 and (Y) are polymerizable liquid crystal compounds having structures different from each other. n is 2 and two Y 1 are compounds having the same structure as each other, and two X 1 have the same structure as each other, and one X 2 These two X 1 a polymerizable liquid crystal compound (Y) having a structure different from that of Two Xs 1 W of 1 X binds to1 But the other X 1 and X 2 The other X 1 and X 2 and the polymerizable liquid crystal compound (Y) each having the same structure as each other. n is 3 and there are three Y 1 are compounds having the same structure as each other, and three X 1 and one X 2 The polymerizable liquid crystal compound (Y) has a structure in which any one of the following three is different from all of the other three.

[0140] Y 1 -CH2CH2-, -CH2O-, -CH2CH2O-, -COO-, -OCOO-, single bond, -N=N-, -CR a =CR b -, -C≡C-, -CR a =N- or -CO-NR a - is preferred. a and R b are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 1 is more preferably -CH2CH2-, -COO- or a single bond, and 1 If there is an X 2 Y bonded to 1 is more preferably -CH2CH2- or CH2O-. 1 and X 2 When all of Y are the same structure, two or more Y 1 It is preferable that there are plural Y 1 When the compound has an asymmetric structure, the compound tends to exhibit smectic liquid crystallinity.

[0141] U 2 is a polymerizable group. 1 is a hydrogen atom or a polymerizable group, preferably a polymerizable group. 1 and U 2Preferably, both of U are polymerizable groups, and preferably both are radically polymerizable groups. Examples of the polymerizable group include the same groups as those exemplified above as the polymerizable group contained in the polymerizable liquid crystal compound (2). 1 and a polymerizable group represented by U 2 The polymerizable groups represented by may be different from each other, but are preferably the same type of group. The polymerizable groups may be in a polymerized state or an unpolymerized state, but are preferably in an unpolymerized state.

[0142] V 1 and V 2 Examples of the alkanediyl group represented by the formula (V) include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a decane-1,10-diyl group, a tetradecane-1,14-diyl group, and an icosane-1,20-diyl group. 1 and V 2 is preferably an alkanediyl group having 2 to 12 carbon atoms, and more preferably an alkanediyl group having 6 to 12 carbon atoms.

[0143] Examples of the substituent that the alkanediyl group may optionally have include a cyano group and a halogen atom, but the alkanediyl group is preferably unsubstituted, and more preferably an unsubstituted linear alkanediyl group.

[0144] W 1 and W 2 are each independently preferably a single bond, -O-, -S-, -COO- or -OCOO-, more preferably a single bond or -O-.

[0145] As a structure that readily exhibits smectic liquid crystallinity, it is preferable for the polymerizable liquid crystal compound to have an asymmetric molecular structure. Specifically, polymerizable liquid crystal compounds having structures represented by the following formulae (Aa) to (Ai) readily exhibit smectic liquid crystallinity and are therefore suitable as the polymerizable liquid crystal compound (Y). Furthermore, from the viewpoint of readily exhibiting higher-order smectic liquid crystallinity, it is more preferable for the polymerizable liquid crystal compound to have a structure represented by formula (Aa), formula (Ab), or formula (Ac). In the following formulae (Aa) to (Ai), * represents a bond (single bond).

[0146] [ka]

[0147] Specific examples of the polymerizable liquid crystal compound (Y) include compounds represented by formulae (A-1) to (A-25). When the polymerizable liquid crystal compound (Y) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans isomer.

[0148] [ka]

[0149] [ka]

[0150] [ka]

[0151] Among these, at least one selected from the group consisting of compounds represented by formula (A-2), formula (A-3), formula (A-4), formula (A-5), formula (A-6), formula (A-7), formula (A-8), formula (A-13), formula (A-14), formula (A-15), formula (A-16), and formula (A-17) is preferred. As the polymerizable liquid crystal compound (Y), one compound may be used alone, or two or more compounds may be used in combination.

[0152] The polymerizable liquid crystal compound (Y) can be produced by a known method such as that described in Lub et al., Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996) or Japanese Patent No. 4719156.

[0153] The composition for forming a polarizing film may contain a polymerizable liquid crystal compound other than the polymerizable liquid crystal compound (Y) as long as the effects of the present invention are not impaired. From the viewpoint of obtaining a polarizing film with a high degree of orientational order, the proportion of the polymerizable liquid crystal compound (Y) to the total mass of all polymerizable liquid crystal compounds (2) in the composition for forming a polarizing film is preferably 51 mass % or more, more preferably 70 mass % or more, and even more preferably 90 mass % or more of the polymerizable liquid crystal compounds are the polymerizable liquid crystal compound (Y), and all (100 mass %) of the polymerizable liquid crystal compounds may be the polymerizable liquid crystal compound (Y).

[0154] When the composition for forming a polarizing film contains two or more polymerizable liquid crystal compounds (2), it is preferable that at least one of them is the polymerizable liquid crystal compound (Y), and all of the compounds contained in the composition for forming a polarizing film may be the polymerizable liquid crystal compound (Y).

[0155] The content of the polymerizable liquid crystal compound (2) in the composition for forming a polarizing film is preferably 40 to 99.9 mass %, more preferably 60 to 99.9 mass %, and even more preferably 70 to 99 mass %, based on the solid content of the composition for forming a polarizing film. When the content of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound (2) tends to be high.

[0156] The polarizing film-forming composition contains a dichroic dye. Here, the dichroic dye refers to a dye having different absorbance in the long axis direction and the short axis direction of the molecule. The dichroic dye usable in the present invention is not particularly limited as long as it has the above-described properties, and may be a dye or a pigment. Two or more dyes or pigments may be used in combination, or a dye and a pigment may be used in combination. Dichroic dyes may be used alone or in combination. However, to achieve absorption across the entire visible light range, it is preferable to combine two or more dichroic dyes, and more preferably to combine three or more dichroic dyes. In particular, mixing two or more dichroic dyes with different absorption wavelengths allows the production of polarizing films of various hues and polarizing films that absorb across the entire visible light range.

[0157] The dichroic dye preferably has the property of absorbing visible light, and has a maximum absorption wavelength (λ ) in the range of 300 to 700 nm. MAX ) is preferred. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes. Of these, azo dyes are preferred.

[0158] Examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, and bisazo dyes and trisazo dyes are preferred, such as a compound represented by formula (I) (hereinafter also referred to as "compound (I)").

[0159] K 1 -(N=NK 2 ) p -N=NK 3 (I) [In formula (I), K 1 and K. 3 represent, independently of each other, an optionally substituted phenyl group, an optionally substituted naphthyl group, an optionally substituted benzoic acid phenyl ester group, or an optionally substituted monovalent heterocyclic group. 2represents a p-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, a 4,4'-stilbenylene group which may have a substituent, or a divalent heterocyclic group which may have a substituent. p represents an integer of 0 to 4. When p is an integer of 2 or more, a plurality of K 2 may be the same or different. The -N=N- bond may be replaced with a -C=C-, -COO-, -NHCO-, or -N=CH- bond as long as the compound exhibits absorption in the visible region.

[0160] Examples of monovalent heterocyclic groups include groups in which one hydrogen atom has been removed from a heterocyclic compound such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, benzoxazole, etc. Examples of divalent heterocyclic groups include groups in which two hydrogen atoms have been removed from the above heterocyclic compounds.

[0161] K 1 and K. 3 Phenyl group, naphthyl group, benzoic acid phenyl ester group and monovalent heterocyclic group in 2 In the formula (I), the p-phenylene group, the naphthalene-1,4-diyl group, the 4,4'-stilbenylene group, and the divalent heterocyclic group may optionally have a substituent, such as an alkyl group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and having a polymerizable group, or an alkenyl group having 1 to 4 carbon atoms; an alkoxy group having 1 to 20 carbon atoms, such as a methoxy group, an ethoxy group, or a butoxy group; an alkoxy group having 1 to 20 carbon atoms and having a polymerizable group; a fluorinated alkyl group having 1 to 4 carbon atoms, such as a trifluoromethyl group; Examples of the polymerizable group include an ano group, a nitro group, a halogen atom, and substituted or unsubstituted amino groups such as an amino group, a diethylamino group, and a pyrrolidino group (a substituted amino group refers to an amino group having one or two alkyl groups of 1 to 6 carbon atoms, an amino group having one or two alkyl groups of 1 to 6 carbon atoms and a polymerizable group, or an amino group in which two substituted alkyl groups are bonded to form an alkanediyl group of 2 to 8 carbon atoms. An unsubstituted amino group is -NH2). Examples of the polymerizable group include a (meth)acryloyl group and a (meth)acryloyloxy group.

[0162] Among the compounds (I), compounds represented by any one of the following formulae (I-1) to (I-8) are preferred. [ka] [In formulas (I-1) to (I-8), B 1 ~B 30 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, a substituted or unsubstituted amino group (the definitions of a substituted amino group and an unsubstituted amino group are as defined above), a chlorine atom, or a trifluoromethyl group. n1 to n4 each independently represent an integer of 0 to 3. If n1 is 2 or more, multiple B 2 may be the same or different from each other, If n2 is 2 or more, multiple B 6 may be the same or different from each other, If n3 is 2 or more, multiple B 9 may be the same or different from each other, If n4 is 2 or more, multiple B 14 may be the same or different.]

[0163] The anthraquinone dye is preferably a compound represented by formula (I-9). [ka] [In formula (I-9), R 1 ~R 8 are, independently of each other, a hydrogen atom, -R x , -NH2, -NHR x , -NR x 2, -SR x or a halogen atom. R x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.

[0164] The oxazone dye is preferably a compound represented by formula (I-10). [ka] [In formula (I-10), R 9 ~R 15 are, independently of each other, a hydrogen atom, -R x , -NH2, -NHR x , -NR x 2, -SR x or a halogen atom. R x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.

[0165] The acridine dye is preferably a compound represented by formula (I-11). [ka] [In formula (I-11), R 16 ~R 23 are, independently of each other, a hydrogen atom, -R x , -NH2, -NHR x , -NR x 2, -SR x or a halogen atom. R x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. In formula (I-9), formula (I-10) and formula (I-11), R x Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group, and examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a toluyl group, a xylyl group, and a naphthyl group.

[0166] As the cyanine dye, compounds represented by formula (I-12) and compounds represented by formula (I-13) are preferred. [ka] [In formula (I-12), D 1 and D 2 represent, independently of each other, a group represented by any one of formulae (I-12a) to (I-12d). [ka] n5 represents an integer from 1 to 3. [ka] [In formula (I-13), D 3 and D 4 represent, independently of each other, a group represented by any one of formulae (I-13a) to (I-13h). [ka] n6 represents an integer from 1 to 3.

[0167] The weight-average molecular weight of the dichroic dye is usually 300 to 2,000, and preferably 400 to 1,000.

[0168] The content of the dichroic dye in the composition for forming a polarizing film can be appropriately determined depending on the type of dichroic dye used, but is preferably 1 to 60 mass %, more preferably 1 to 20 mass %, and even more preferably 1 to 15 mass %, based on the solid content of the composition for forming a polarizing film. When the content of the dichroic dye is within the above range, the orientation of the polymerizable liquid crystal compound (2) is unlikely to be disturbed, and a polarizing film having a high degree of orientational order can be obtained.

[0169] The polarizing film-forming composition may contain a polymerization initiator. As the polymerization initiator, a photopolymerization initiator that generates active radicals or acids under the action of light is preferred, as it can initiate a polymerization reaction under lower temperature conditions, and a photopolymerization initiator that generates radicals under the action of light is more preferred. The polymerization initiators may be used alone or in combination of two or more.

[0170] As the photopolymerization initiator, known photopolymerization initiators can be used, for example, the same ones as those exemplified above as those usable in the adhesive composition (1), and the initiator may be appropriately selected in relation to the polymerizable liquid crystal compound (2) that forms the polarizing film.

[0171] The content of the polymerization initiator is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, even more preferably 0.5 to 10 parts by mass, and particularly preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound (2). When the content of the polymerization initiator is within the above range, the polymerization reaction can be carried out without significantly disturbing the alignment of the polymerizable liquid crystal compound (2).

[0172] The polarizing film-forming composition may contain, as necessary, a leveling agent, an additive exemplified as an additive contained in the retardation film-forming composition, etc. Examples of the leveling agent and additive include the same as those exemplified above as additives that can be used in the polarizing film-forming composition, and each of them can be used in approximately the same amount as in the polarizing film-forming composition.

[0173] The composition for forming a polarizing film can be produced by a conventionally known method for preparing a liquid crystal composition, and can usually be prepared by mixing and stirring a polymerizable liquid crystal compound and a dichroic dye, and, if necessary, a polymerization initiator and the above-mentioned additives, etc. Furthermore, since liquid crystal compounds exhibiting smectic liquid crystallinity generally have high viscosity, the viscosity may be adjusted by adding a solvent to the composition from the viewpoint of improving the coatability of the liquid crystal composition and facilitating the formation of a polarizing film.

[0174] The solvent may be appropriately selected depending on the solubility of the polymerizable liquid crystal compound and the dichroic dye to be used, and is preferably a solvent that can completely dissolve the components and is inactive to the polymerization reaction. Examples of the solvent include the same solvents as those exemplified above as those that can be used in the retardation film-forming composition.

[0175] The thickness of the polarizing film can be appropriately selected depending on the display device it is to be used in. In one embodiment of the present invention, the thickness of the polarizing film is preferably 0.1 to 5 μm, more preferably 0.5 to 3 μm.

[0176] In the present invention, the polarizing film is preferably a liquid crystal cured film having a high degree of orientational order. A liquid crystal cured film having a high degree of orientational order exhibits a Bragg peak derived from a higher-order structure such as a hexatic phase or a crystalline phase in X-ray diffraction measurement. A Bragg peak refers to a peak derived from the planar periodic structure of molecular orientation. Therefore, the polarizing film constituting the optical laminate of the present invention preferably exhibits a Bragg peak in X-ray diffraction measurement. That is, in the polarizing film of the present invention, the polymerizable liquid crystal compound (2) or its polymer is preferably oriented so that the film exhibits a Bragg peak in X-ray diffraction measurement. In one embodiment of the present invention, the planar periodic spacing of the molecular orientation is preferably 3.0 to 6.0 Å. A high degree of orientational order that exhibits a Bragg peak can be achieved by controlling the type of polymerizable liquid crystal compound used, the type and amount of dichroic dye, and the type and amount of polymerization initiator, etc.

[0177] In the present invention, the polarizing film can be formed on an alignment film. Examples of the alignment film include those similar to those exemplified above as films that can be used when preparing a liquid crystal retardation film, and the film can be appropriately selected depending on the desired alignment control force, etc. In one embodiment of the present invention, a photo-alignment film is preferred from the viewpoints of easily improving alignment precision and adhesion to a cured product layer formed from a polarizing film-forming composition.

[0178] The thickness of the alignment film is usually 10 to 5000 nm, preferably 10 to 1000 nm, more preferably 10 to 500 nm, still more preferably 10 to 300 nm, and particularly preferably 30 to 300 nm. When the thickness of the alignment film is within the above range, the alignment film can exhibit good adhesion at the interface with a cured product layer formed from the polarizing film-forming composition on the alignment film, while also exhibiting alignment regularity, allowing the formation of a polarizing film with high alignment order.

[0179] The polarizing film can be produced by, for example, forming a coating film of a polarizing film-forming composition; removing the solvent from the coating; raising the temperature to a temperature at which the polymerizable liquid crystal compound (2) undergoes a phase transition to a liquid phase or higher, and then lowering the temperature to cause the polymerizable liquid crystal compound (2) to undergo a phase transition to a liquid crystal phase (e.g., a smectic liquid crystal phase); and polymerizing the polymerizable liquid crystal compound (2) while maintaining the liquid crystal phase; It can be produced by a method comprising:

[0180] Methods that can be employed for applying the composition for forming a polarizing film or for curing the polymerizable liquid crystal compound by light irradiation include the same methods as those exemplified in the method for forming the adhesive composition (1) or the liquid crystal retardation film.

[0181] In one embodiment of the present invention, the laminate of the present invention preferably comprises a hard coat layer, an adhesive layer (1), and a liquid crystal cured film adjacent to the adhesive layer (1), in this order, or a polarizing film, an adhesive layer (1), and a liquid crystal cured film adjacent to the adhesive layer (1), in this order. The optical laminate of the present invention may further comprise other layers in addition to the polarizing film, the hard coat layer, the adhesive layer (1), and the liquid crystal retardation film adjacent to the adhesive layer (1), as long as the effects of the present invention are not affected. Examples of other layers include an alignment film for forming a polarizing film and a pressure-sensitive adhesive layer other than the adhesive layer (1). In one embodiment of the present invention, the laminate of the present invention more preferably comprises a polarizing film, an alignment film, a hard coat layer, an adhesive layer (1), and a liquid crystal cured film adjacent to the adhesive layer (1), in this order.

[0182] The optical laminate of the present invention can be produced, for example, by laminating a liquid crystal retardation film on an adhesive layer (1) formed from the adhesive composition (1). In the case of an optical laminate that functions as a circular polarizer, it can be produced, for example, by a method including a step of applying the adhesive composition (1) to one side of a polarizing film and laminating the polarizing film onto the liquid crystal retardation film via the adhesive layer (1) formed from the adhesive composition (1). In this case, it is preferable to laminate the liquid crystal retardation film so that the slow axis (optical axis) of the liquid crystal retardation film and the absorption axis of the polarizing film form an angle of substantially 45°. By laminating the liquid crystal retardation film so that the slow axis (optical axis) of the liquid crystal retardation film and the absorption axis of the polarizing film form an angle of substantially 45°, the function of a circular polarizer can be obtained.

[0183] The optical laminate of the present invention is unlikely to suffer a decrease in retardation value and has an excellent light reflection suppression effect, so it is expected to have high optical properties and can be suitably used, for example, as a circular polarizing plate or as a constituent material for organic EL display devices, etc. A display device is a device having a display element, and includes a light-emitting element or a light-emitting device as a light source. Examples of display devices include liquid crystal display devices, organic electroluminescence (EL) display devices, inorganic electroluminescence (EL) display devices, touch panel display devices, electron emission display devices (e.g., field emission displays (FEDs) and surface field emission displays (SEDs)), electronic paper (display devices using electronic ink or electrophoretic elements), plasma display devices, projection display devices (e.g., grating light valve (GLV) displays and displays having a digital micromirror device (DMD)), and piezoelectric ceramic displays. Liquid crystal display devices include any of transmissive liquid crystal display devices, semi-transmissive liquid crystal display devices, reflective liquid crystal display devices, direct-view liquid crystal display devices, and projection liquid crystal display devices. These display devices may be displays that display two-dimensional images or stereoscopic display devices that display three-dimensional images. In particular, the optical laminate of the present invention can be suitably used in organic electroluminescence (EL) display devices and inorganic electroluminescence (EL) display devices, and can also be suitably used in liquid crystal display devices and touch panel display devices. These display devices can exhibit good image display characteristics because the optical laminate of the present invention has excellent durability and high visibility. [Example]

[0184] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples and comparative examples, "parts" and "%" refer to "parts by mass" and "% by mass" unless otherwise specified.

[0185] 1. Preparation of Adhesive Composition The curable components were mixed by stirring for 30 minutes according to the formulation shown in Table 1. Next, a polymerization initiator was added, and the mixture was stirred and mixed for 24 hours to prepare adhesive compositions (A) to (G) of Examples 1 to 5 and Comparative Examples 1 and 2. In Table 1, the polymerization initiator represents the number of parts of solid content.

[0186] [Table 1]

[0187] The abbreviations for each component used in Table 1 are as follows: UA-122P: Urethane acrylate oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., product name "UA-122P", viscosity: 45,000 mPa·s / 40°C, molecular weight: 1100 g / mol, number of functional groups (number of (meth)acrylate groups): 2) 4-HBA: 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd., trade name "4-HBA", viscosity: 5.5 mPa s, molecular weight: 144.2 g / mol, refractive index: 1.46) A-LEN-10: Ethoxylated o-phenylphenol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "A-LEN-10", viscosity: 130 mPa·s / 25°C, molecular weight: 268.31 g / mol, refractive index: 1.58) M-600A: 2-hydroxy-3-phenoxypropyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., product name "M-600A", viscosity: 150-200 mPa·s / 25°C, molecular weight: 222.24 g / mol, refractive index: 1.53) Omnirad819: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by IGM Resins BV, trade name "Omnirad819"), molecular weight: 418.5 g / mol, molar absorption coefficient at 400 nm: 1125 L mol -1 ·cm -1 )

[0188] 2. Preparation of optical laminates <Optical laminate of Example 1> (1) Preparation of laminated film with polarizing film (i) Preparation of composition (1) for forming photoalignment film Copolymer (1) having the following structure was prepared by the following procedure: In the following structure, l, m, and n are each an integer of 0 or more and 100 or less, and l+m+n=100 is satisfied. [ka]

[0189] Chlorodimethyl ether was added dropwise to a solution of 4-((6-(methacryloyloxy)hexyl)oxy)benzoic acid dissolved in toluene together with an amine catalyst, and the reaction was allowed to proceed by heating and maintaining the temperature at 40°C. The reaction solution was then cooled and water was added. The organic layer was separated from the resulting mixture, and a 50% aqueous solution of acetic acid was added to the separated organic layer and stirred to obtain a mixture. The organic layer was separated from the resulting mixture and the separated organic layer was concentrated to obtain methoxymethyl 4-((6-(methacryloyloxy)hexyl)oxy)benzoate. 8.8 g (25.2 mmol) of methoxymethyl 4-((6-(methacryloyloxy)hexyl)oxy)benzoate, 1.0 g (3.6 mmol) of 6-(4-hydroxyphenoxy)hexyl methacrylate, 3.2 g (7.2 mmol) of 4-((6-methacryloyloxy)hexyl)oxy)phenyl(E)-3-(4-methoxyphenyl)acrylate, and 0.2 g of 2,2'-azobis(2,4-dimethylvaleronitrile) were dissolved in tetrahydrofuran. Nitrogen was bubbled through the solution for 1 hour, and the reaction was allowed to proceed by heating and maintaining the temperature at 60°C. The reaction solution was then cooled to room temperature. 1.1 g (3.6 mmol) of 4-((6-(methacryloyloxy)hexyl)oxy)benzoic acid and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride were added to the reaction solution to obtain a mixed solution. The reaction was allowed to proceed by heating the mixture to 40°C, and then the reaction mixture was cooled. Methanesulfonic acid was added to the reaction mixture at room temperature, and the mixture was heated to 70°C. The reaction mixture was then cooled to approximately room temperature. The cooled reaction mixture was added dropwise to normal hexane to produce a precipitate, which was then collected and dried under reduced pressure to obtain a polymer. The weight-average molecular weight of copolymer (1) was measured by GPC and found to be 24,000.

[0190] Next, 2 parts of the copolymer (1) obtained was mixed with 98 parts of propylene glycol methyl ether acetate to obtain a mixture, which was stirred at 80°C for 1 hour to obtain a composition (1) for forming a photo-alignment film.

[0191] (ii) Preparation of a composition for forming a polarizing film A composition for forming a polarizing film was obtained by mixing the components described below and stirring for 1 hour at 80° C. The polymerizable liquid crystal compound (Y1), the polymerizable liquid crystal compound (Y2), and the dichroic dyes (DP1) to (DP3) each have the structure shown below. ·Polymerizable liquid crystal compound (Y1): 75 parts ·Polymerizable liquid crystal compound (Y2): 25 parts ·Dichroic dye (DP1): 2.5 parts Dichroic dye (DP2): 2.5 parts Dichroic dye (DP3): 2.5 parts Polymerization initiator [2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure® 369; manufactured by BASF Japan Ltd.)]: 6 parts Leveling agent [polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)]: 1.2 parts Solvent [o-xylene]: 250 parts

[0192] Polymerizable liquid crystal compound (Y1) [ka] Polymerizable liquid crystal compound (Y2) [ka] Dichroic dye (DP1) [ka] Dichroic dye (DP2) [ka] Dichroic dye (DP3) [ka]

[0193] (iii) Preparation of laminated film with polarizing film The surface of the hard coat layer of the release film with a hard coat layer was subjected to a corona treatment. The photoalignment film-forming composition (1) was applied to the corona-treated surface using a coating device, dried at 80°C for 1 minute, and then irradiated with 50 mJ / cm using a polarized UV irradiation device (SPOTCURESP-9 with polarizer unit; manufactured by Ushio Inc.). 2 Polarized UV exposure (in air, cumulative light intensity at wavelength 313 nm: 50 mJ / cm 2 ) was carried out to form a photo-alignment film (1). The thickness of the obtained photo-alignment film (1) was measured with an ellipsometer M-220 (manufactured by JASCO Corporation) and was found to be 100 nm.

[0194] A polarizing film-forming composition was applied onto the obtained photo-alignment film (1) using a coating device, and then heated and dried for 1 minute in a drying oven set at 120°C to obtain a dried film. Next, using a UV irradiation device (UniCure VB-15201BY-A, manufactured by Ushio Inc.), ultraviolet light was irradiated onto the dried film surface of the polarizing film-forming composition (under a nitrogen atmosphere, cumulative light intensity at a wavelength of 365 nm: 500 mJ / cm). 2 ) to form a polarizing film in which the polymerizable liquid crystal compound and the dichroic dye were aligned, and a laminated film with a polarizing film consisting of a release film / hard coat layer / photoalignment film (1) / polarizing film was obtained. The thickness of the polarizing film was measured using an M-220 ellipsometer (manufactured by JASCO Corporation) and found to be 2.0 μm. Furthermore, X-ray diffraction measurements of the polarizing film using an X'PertPROMPD X-ray diffractometer (manufactured by Spectris Corporation) revealed a sharp diffraction peak (Bragg peak) with a full width at half maximum (FWHM) of approximately 0.17° near 2θ = 20.2°. The order period (d) calculated from the peak position was approximately 4.4 Å, confirming the formation of a structure reflecting a high-order smectic phase.

[0195] (2) Preparation of laminated film with liquid crystal retardation film (1) (i) Preparation of composition (2) for forming photoalignment film A photo-alignment material (weight average molecular weight: 50,000, m:n = 50:50) having the following structure was produced in accordance with the method described in JP 2021-196514 A. Two parts by mass of the photo-alignment material and 98 parts by mass of cyclopentanone (solvent) were mixed as components, and the resulting mixture was stirred at 80°C for 1 hour to prepare a composition (2) for forming a photo-alignment film. [ka]

[0196] (ii) Preparation of retardation film-forming composition (1) A polymerizable liquid crystal compound (X1) and a polymerizable liquid crystal compound (X2) each having the structure shown below were prepared. ·Polymerizable liquid crystal compound (X1): [ka] ·Polymerizable liquid crystal compound (X2): [ka]

[0197] A solution was obtained by dissolving 1 mg of polymerizable liquid crystal compound (X1) in 10 mL of chloroform. The obtained solution was placed in a measurement cell with an optical path length of 1 cm to prepare a measurement sample. The measurement sample was then set in an ultraviolet-visible spectrophotometer (Shimadzu Corporation, "UV-2450") to measure the absorption spectrum. The wavelength at which the maximum absorbance was obtained was read from the obtained absorption spectrum, and the maximum absorption wavelength λmax in the wavelength range of 300 to 400 nm was 356 nm.

[0198] A polymerizable liquid crystal compound (X1) and a polymerizable liquid crystal compound (X2) were mixed in a mass ratio of 90:10 to obtain a mixture. To 100 parts by mass of the obtained mixture, 0.1 parts by mass of a leveling agent "BYK-361N" (manufactured by BMChemie) and 3 parts by mass of a photopolymerization initiator "Irgacure OXE-03" (manufactured by BASF Japan Ltd.) were added. Furthermore, N-methyl-2-pyrrolidone (NMP) was added so that the solids concentration became 13% by mass. The mixture was stirred at a temperature of 80°C for 1 hour to obtain a retardation film-forming composition (1).

[0199] (iii) Preparation of a laminated film with a liquid crystal retardation film The release-treated surface of the release film was subjected to a corona treatment, and the photo-alignment film-forming composition (2) was applied to the corona-treated surface of the release film using an adhesive applicator. The resulting coating was dried at 120°C for 2 minutes and then cooled to room temperature to form a dry film. Thereafter, a UV irradiation device (SPOTCURESP-9; manufactured by Ushio Inc.) was used to irradiate the film with 100 mJ of polarized ultraviolet light (313 nm standard) to obtain a photo-alignment film (2). The thickness of the photo-alignment film (2) was measured using an Ellipsometer M-220 manufactured by JASCO Corporation, and was found to be 100 nm.

[0200] The retardation film-forming composition (1) was applied onto the obtained photo-alignment film (2) using a coating device to form a coating film. This coating film was dried by heating at 120°C for 2 minutes and then cooled to room temperature to obtain a dried film. Next, using a high-pressure mercury lamp ("Uniquer VB-15201BY-A" manufactured by Ushio Inc.), the exposure dose was 500 mJ / cm under a nitrogen atmosphere. 2 The dried film was irradiated with ultraviolet light (365 nm standard) to form a retardation liquid crystal cured film (1) in which the polymerizable liquid crystal compound was cured in a state of being aligned horizontally relative to the substrate surface, thereby obtaining a laminate film with the liquid crystal retardation film (1). The resulting laminate film with the liquid crystal retardation film (1) had a structure of release film / liquid crystal retardation film (1) (photo-alignment film (2) / cured retardation liquid crystal film (1) (horizontally aligned liquid crystal cured film)). The thickness of the cured retardation liquid crystal film (1) was measured using a laser microscope LEXTOLS4100 manufactured by Olympus Corporation, and was found to be 2.0 μm.

[0201] (iv) In-plane retardation measurement of liquid crystal retardation film (1) The liquid crystal retardation film (1) side of the laminate film with the liquid crystal retardation film (1) was subjected to corona treatment. A 25 μm thick acrylic adhesive was laminated on the corona-treated surface, and the laminate was attached to glass via the acrylic adhesive. The release film was peeled off from the obtained laminate, and a retardation evaluation laminate having a configuration of liquid crystal retardation film (1) / acrylic adhesive / glass was obtained. Using the obtained retardation evaluation laminate, the in-plane retardation value of the liquid crystal retardation film (1) was measured using KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. The in-plane retardation values ​​for light with wavelengths of 450 nm, 550 nm, and 650 nm were calculated using Cauchy's dispersion formula obtained from the measurement results of the in-plane retardation values ​​for light with wavelengths of 448.2 nm, 498.6 nm, 548.4 nm, 587.3 nm, 628.7 nm, and 748.6 nm. As a result, the in-plane retardation values ​​were Re(450)=122 nm, Re(550)=140 nm, and Re(650)=144 nm, and the relationship between the in-plane retardation values ​​at each wavelength was as follows: Re(450) / Re(550)=0.87 Re(650) / Re(550)=1.03 Note that Re(450) represents the in-plane retardation value for light with a wavelength of 450 nm, Re(550) represents the in-plane retardation value for light with a wavelength of 550 nm, and Re(650) represents the in-plane retardation value for light with a wavelength of 650 nm.

[0202] (3) Preparation of laminated film with liquid crystal retardation film (2) (i) Preparation of a composition for forming a vertical alignment film As a composition for forming a vertical alignment film, a mixture of 2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, dipentaerythritol triacrylate, and bis(2-vinyloxyethyl) ether in a ratio of 1:1:4:5 was used, and LUCIRINTPO was added as a polymerization initiator in a ratio of 4% by mass relative to the composition for forming a vertical alignment film.

[0203] (ii) Preparation of retardation film-forming composition (2) A mixed solvent was prepared by mixing methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone (CHN) in a mass ratio (MEK:MIBK:CHN) of 35:30:35. A photopolymerizable nematic liquid crystal compound (RMM28B, manufactured by Merck) was mixed with 100 parts by mass of the mixed solvent so that the solid content was 1 to 1.5 parts by mass, thereby preparing a retardation film-forming composition (2).

[0204] (iii) Preparation of a laminated film with a liquid crystal retardation film (2) The composition for forming a vertical alignment film was applied to the release-treated surface of a polyethylene terephthalate film (thickness 38 μm) that had been subjected to a release treatment, and the composition was applied at 200 mJ / cm 2 The vertical alignment film was formed by irradiating the film with ultraviolet light of 1000 kJ / cm. The thickness of the vertical alignment film was 3.0 μm.

[0205] The retardation film-forming composition (2) was applied onto the vertical alignment film by die coating. The coating solution was dried at a drying temperature of 75°C for 120 seconds to form a coating. The coating was then irradiated with ultraviolet (UV) light to polymerize the polymerizable liquid crystal compound, thereby obtaining a laminate film with a liquid crystal retardation film (2). The resulting laminate film with a liquid crystal retardation film (2) had a configuration of liquid crystal retardation film (2) (cured retardation liquid crystal film (2) / vertical alignment film) / polyethylene terephthalate film. The thickness of the cured retardation liquid crystal film (2) was measured using a laser microscope LEXTOLS4100 manufactured by Olympus Corporation, and was found to be 1.0 μm.

[0206] (4) Preparation of laminate 01 The surfaces of the liquid crystal retardation films of the laminate film with the liquid crystal retardation film (1) and the laminate film with the liquid crystal retardation film (2) were subjected to corona treatment, and the liquid crystal retardation film (1) and the liquid crystal retardation film (2) were bonded together using a cationic adhesive composition so that the bonding surfaces were the surfaces. Next, the cationic adhesive composition was cured by irradiation with ultraviolet light to produce a laminate 01. The resulting laminate 01 had a structure of release film / liquid crystal retardation film (1) (photo-alignment film (2) / cured liquid crystal retardation film (1)) / cationic adhesive layer / liquid crystal retardation film (2) (cured liquid crystal retardation film (2) / vertical alignment film) / polyethylene terephthalate film (release film).

[0207] (5) Preparation of laminate (A-1) The release film of the laminate film with polarizing film was peeled off, and the surface of the hard coat layer was subjected to corona treatment. The release film on the liquid crystal retardation film (1) side of the laminate 01 was peeled off, and the surface of the photoalignment film (2) was subjected to corona treatment. The adhesive composition (A) was applied to the corona-treated surface using a coating device to form a coating layer. The hard coat layer surface that had been subjected to the above corona treatment was laminated on the resulting coating layer. Using an ultraviolet irradiation device equipped with a belt conveyor (the lamp was a mercury lamp manufactured by Eye Graphics), the obtained laminate was irradiated from the liquid crystal retardation film (1) side with an integrated light intensity of 400 mJ / cm. 2 The adhesive composition (A) was cured by irradiation with UV light (UV-B) to obtain a laminate (A-1). The resulting laminate (A-1) had a structure of polarizing film / photo-alignment film (1) / hard coat layer / adhesive layer (cured layer of adhesive composition (A)) / liquid crystal retardation film (1) (photo-alignment film (2) / cured retardation liquid crystal film (1)) / cationic adhesive layer / liquid crystal retardation film (2) (cured retardation liquid crystal film (2) / vertical alignment film) / polyethylene terephthalate film (release film). The thickness of the cured layer of adhesive composition A was 2 μm.

[0208] (6) Preparation of laminate 02 The surface of a 25 μm-thick norbornene-based resin film was subjected to corona treatment. Next, a release film with a pressure-sensitive adhesive layer, consisting of a 5 μm-thick acrylic pressure-sensitive adhesive layer A and a release film, was laminated on the corona-treated surface of the norbornene-based resin film from the acrylic pressure-sensitive adhesive layer A side. This produced a norbornene-based resin film / acrylic pressure-sensitive adhesive layer A / release film laminate 02.

[0209] (7) Preparation of laminate (B-1) The polarizing film side of the laminate (A-1) was subjected to corona treatment. Next, the release film of the laminate 02 was peeled off, and the acrylic pressure-sensitive adhesive layer A side of the laminate 02 was attached to the corona-treated surface of the laminate (A-1) to obtain a laminate. The release film on the liquid crystal retardation film (2) side of the obtained laminate was peeled off, and the vertical alignment film side was subjected to corona treatment. The pressure-sensitive adhesive layer B side of a pressure-sensitive adhesive layer-attached release film consisting of a 20 μm-thick acrylic pressure-sensitive adhesive layer B and a release film was laminated on the corona-treated surface to obtain a laminate (B-1). The resulting laminate (B-1) had a structure of norbornene resin film / acrylic pressure-sensitive adhesive layer A / polarizing film / photo-alignment film (1) / hard coat layer / adhesive layer (cured layer of adhesive composition A) / liquid crystal retardation film (1) (photo-alignment film (2) / cured retardation liquid crystal film (1)) / cationic adhesive layer / liquid crystal retardation film (2) (cured retardation liquid crystal film (2) / vertical alignment film) / acrylic pressure-sensitive adhesive layer B / release film.

[0210] (8) Preparation of laminate 03 One side of a 25 μm thick norbornene-based resin film (ZEONORFILM ZF-14) was subjected to corona treatment. The release film on the liquid crystal retardation film (1) side of the laminate 01 was peeled off, and the surface of the photoalignment film (2) was subjected to corona treatment. Next, the adhesive composition A was coated on the corona-treated surface using a coating device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.). The resulting coating layer and the corona-treated surface of the 25 μm thick norbornene-based resin film were laminated to obtain a laminate. The resulting laminate was then exposed to ultraviolet light at an integrated dose of 400 mJ / cm using an ultraviolet irradiation device equipped with a belt conveyor (the lamp was a mercury lamp manufactured by Eye Graphics Co., Ltd.). 2The coating layer was cured by irradiating it with UV light (UV-B) from the laminate 01 side to obtain laminate 03. The resulting laminate 03 had a structure of norbornene resin film / adhesive layer (cured layer of adhesive composition A) / liquid crystal retardation film (1) (photo-alignment film (2) / cured retardation liquid crystal film (1)) / cationic adhesive layer / liquid crystal retardation film (2) (cured retardation liquid crystal film (2) / vertical alignment film) / release film.

[0211] (9) Preparation of laminate (C-1) The release film was peeled off from the obtained laminate 03, and the vertical alignment film was subjected to a corona treatment. The corona-treated surface was laminated to the pressure-sensitive adhesive layer B side of a release film with a pressure-sensitive adhesive layer, which was composed of a 20 μm-thick acrylic pressure-sensitive adhesive layer B and a release film, to obtain a laminate (C-1). The resulting laminate (C-1) had a structure of norbornene-based resin film / adhesive layer (cured layer of adhesive composition A) / liquid crystal retardation film (1) (photo-alignment film (2) / cured retardation liquid crystal film (1)) / cationic adhesive layer / liquid crystal retardation film (2) (cured retardation liquid crystal film (2) / vertical alignment film) / acrylic pressure-sensitive adhesive layer B / release film.

[0212] <Optical laminates of Examples 2 to 5 and Comparative Examples 1 and 2> The adhesive composition (A) used in Example 1 was replaced with adhesive compositions (B) to (G), respectively, to produce laminates (A-2) to (A-7), laminates (B-2) to (B-7), and laminates (C-2) to (C-7). The laminates of Examples 2 to 5 and Comparative Examples 1 and 2 had the following structures. The laminates using the adhesive composition (B) are the laminate (A-2), the laminate (B-2), and the laminate (C-2) (Example 2). The laminates using the adhesive composition (C) are the laminate (A-3), the laminate (B-3), and the laminate (C-3) (Example 3). The laminates using the adhesive composition (D) are the laminate (A-4), the laminate (B-4), and the laminate (C-4) (Example 4). The laminates using adhesive composition (E) are laminate (A-5), laminate (B-5), and laminate (C-5) (Example 5). The laminates using adhesive composition (F) are laminate (A-6), laminate (B-6), and laminate (C-6) (Comparative Example 1). The laminates using adhesive composition (G) are laminate (A-7), laminate (B-7), and laminate (C-7) (Example 7).

[0213] 3. Evaluation of optical laminates (1) Thickness measurement Unless otherwise specified, the thickness of each layer was measured using a digital micrometer "MH-15M" manufactured by Nikon Corporation.

[0214] (2) Refractive index (n3) of the cured layer (adhesive layer) of the adhesive composition Each of the adhesive compositions (A) to (G) used in the Examples and Comparative Examples was coated onto one side of a stretched norbornene-based resin film ("ZEONORFILM" manufactured by ZEON Corporation) using an adhesive coating device (manufactured by Daiichi Rika Co., Ltd.) so that the thickness after ultraviolet irradiation would be approximately 30 μm. A stretched norbornene-based resin film was then placed over the coated surface to obtain a laminate consisting of stretched norbornene-based resin film / adhesive composition / stretched norbornene-based resin film. Next, this laminate was irradiated with ultraviolet light from a belt conveyor-equipped ultraviolet irradiation device (the lamp was a mercury lamp manufactured by Eye Graphics Co., Ltd.) with an integrated light dose of 400 mJ / cm. 2 The adhesive composition was cured by irradiating it with ultraviolet light (UV-B). After UV irradiation, the two stretched norbornene resin films were peeled off from the laminate to obtain a cured adhesive composition. The refractive index (589 nm) of the obtained cured product was measured using a multi-wavelength Abbe refractometer ("DR-M2" manufactured by Atago Co., Ltd.) at 25°C.

[0215] (3) Refractive index of the hard coat layer (n1) The in-plane average refractive index of the hard coat layer was measured as follows. The release film with the hard coat layer was peeled off, and the refractive index (589 nm) of the cured layer was measured using a multi-wavelength Abbe refractometer ("DR-M2" manufactured by Atago Co., Ltd.) in an environment of 25°C. The in-plane average refractive index of the hard coat layer was 1.52.

[0216] (4) Refractive index of the liquid crystal retardation film (n2) The in-plane average refractive index of the liquid crystal retardation film was measured as follows. Using the retardation evaluation laminate (liquid crystal retardation film (1) / acrylic adhesive / glass) prepared for in-plane retardation measurement, the in-plane refractive indexes nx and ny at 589 nm were measured using KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. Using nx and ny, the in-plane average refractive index n was calculated from the following formula. n = (nx + ny) / 2 (In the formula, nx represents the refractive index in the slow axis direction in the film plane, ny represents the refractive index in the fast axis direction in the film plane, and n represents the average in-plane refractive index.) The in-plane average refractive index of the liquid crystal retardation film (1) was 1.59. From the in-plane average refractive index n1 of the hard coat layer obtained above, the in-plane average refractive index n2 of the liquid crystal retardation film, and the in-plane average refractive index n3 of each adhesive layer, the following formula: |(n1×n2) 1 / 2 -n3| The values ​​were calculated, and the results are shown in Table 2.

[0217] (5) Evaluation of coatability The release film on the liquid crystal retardation film (1) side of the laminate 01 was peeled off, and the photoalignment film (2) was treated once using a corona treatment device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.) at an output of 0.8 kW and a treatment speed of 10 m / min. Next, the adhesive composition (A) was applied to the corona-treated surface and allowed to stand for 10 minutes at a temperature of 23°C and a humidity of 55%. Thereafter, the coatability was evaluated by visually checking whether the curable adhesive composition had been applied without repelling or uneven film thickness. The evaluation criteria are as follows. A: The coating is uniform and there is no repelling or unevenness in the coating thickness. B: Coating is possible, but some repelling and uneven film thickness are observed. C: Difficult to apply The adhesive composition (A) was replaced with adhesive compositions (B) to (G), and the evaluation was carried out in the same manner. The results are shown in Table 2.

[0218] (6) Viscosity measurement The viscosity of the coating liquids of adhesive compositions (A) to (G) used in the examples and comparative examples was measured in accordance with JIS K7117-2 using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.) The results are shown in Table 2.

[0219] (7) Evaluation of adhesion The laminate (B-1) was cut into a size of 200 mm long (parallel to the absorption axis direction of the polarizer) x 25 mm wide. The release film on the acrylic pressure-sensitive adhesive layer B was peeled off and the laminate was attached to a glass plate to obtain an evaluation sample. The resulting evaluation sample laminate (B-1) was cut with a cutter blade and peeled 30 mm from the end in the longitudinal direction. The peeled portion was then gripped with the gripping part of the testing machine, with the lower part of the grip holding the glass plate. A peel test was performed on this laminate (B-1) in this state at a temperature of 23°C and a relative humidity of 55% in accordance with JIS K6854-2:1999 "Adhesives - Peel Adhesion Strength Test Method - Part 2: 180° Peel" at a gripping speed of 300 mm / min. The position where peeling began was designated as 0 mm, and the average peel force over a length from 50 mm to 100 mm was determined, and this was designated the peel strength (N) of the laminate (B-1). The peel strength was measured after the laminate (B-1) was attached to glass and then left in an environment of a temperature of 23° C. and a relative humidity of 50% RH for 24 hours. The laminate (B-1) was replaced with the laminates (B-2) to (B-7), and evaluation was carried out in the same manner. The evaluation criteria were as follows. The results are shown in Table 2. A: Peel strength is greater than 0.8N and the peel interface is not between the adhesive and the adjacent layer. B: The peel strength between the adhesive and the adjacent layer is 0.2 to 0.8 N. C: The peel strength between the adhesive and the adjacent layer is 0.2 N or less.

[0220] (8) Durability evaluation of polarizing plates The laminate (C-1) was cut into a size of 30 mm x 30 mm, and the release film on the adhesive layer B side of the laminate (C-1) was peeled off. The laminate was then attached to a 40 mm x 40 mm alkali-free glass (Corning Eagle XG) to obtain an evaluation sample. A heating experiment was performed in which the sample was left to stand in an environment at a temperature of 105°C for 30 minutes, and the retardation value (Re) of the evaluation sample before and after the test was evaluated at a measurement wavelength of 589 nm. The retardation value (Re) and retardation value change (ΔRe) are defined as follows: Re=(nx-ny)×d (In the formula, nx represents the refractive index in the slow axis direction in the film plane, ny represents the refractive index in the fast axis direction in the film plane, and d represents the thickness of the film.) ΔRe = (phase difference value after heating) - (phase difference value before heating) The laminate (B-1) was replaced with the laminates (B-2) to (B-7), and the evaluation was carried out in the same manner. The results are shown in Table 2. In Comparative Example 1, the coating properties were poor and it was not possible to prepare a sample, so the peel strength and durability could not be evaluated.

[0221] [Table 2]

[0222] <Examples 6 to 9 and Comparative Example 3> (1) Preparation of adhesive composition The curable compounds were mixed and stirred for 30 minutes according to the compositions shown in Table 3. Next, a polymerization initiator was added and mixed and stirred for 24 hours to prepare adhesive compositions (H) to (L). In Table 3, the polymerization initiator represents the number of parts of solid content.

[0223] [Table 3]

[0224] The abbreviations for each component used in Table 3 are as follows: UV-3000B: Urethane acrylate oligomer (manufactured by Mitsubishi Chemical Corporation, product name "UV-3000B", viscosity: 40,000 to 60,000 mPa·s / 60°C, molecular weight: 18,000 g / mol, number of functional groups (number of (meth)acrylate groups): 2) UV-3700B: Urethane acrylate oligomer (manufactured by Mitsubishi Chemical Corporation, product name "UV-3700B", viscosity: 30,000 to 60,000 mPa·s / 60°C, molecular weight: 38,000 g / mol, number of functional groups (number of (meth)acrylate groups): 2) The curable compounds b to d and the polymerization initiator are the same as those used in the adhesive compositions (A) to (G).

[0225] (2) Preparation of optical laminate The adhesive composition (A) used in Example 1 was replaced with adhesive compositions (H) to (L), respectively, to produce laminates (A-8) to (A-12), laminates (B-8) to (B-12), and laminates (C-8) to (C-12). The laminates of Examples 6 to 9 and Comparative Example 3 had the following structures. The laminates using adhesive composition (H) are laminate (A-8), laminate (B-8), and laminate (C-8) (Example 6). The laminates using the adhesive composition (I) are laminate (A-9), laminate (B-9), and laminate (C-9) (Example 7). The laminates using adhesive composition (J) are laminate (A-10), laminate (B-10), and laminate (C-10) (Example 8). The laminates using the adhesive composition (K) are laminate (A-11), laminate (B-11), and laminate (C-11) (Example 9). The laminates using adhesive composition (L) are laminate (A-12), laminate (B-12), and laminate (C-12) (Comparative Example 3).

[0226] (3) Evaluation of optical laminates Various physical properties and characteristics were measured and evaluated in the same manner as for the optical laminate of Example 1. The results are shown in Table 4.

[0227]

Table 4

Claims

1. The following curable compounds: a) Urethane (meth)acrylate having two or less (meth)acrylic groups in the molecule b) (Meth)acrylates that do not have an aromatic ring in the molecule and have a hydroxyl group c) a (meth)acrylate having no hydroxyl group and two or more aromatic rings in the molecule, and d) (meth)acrylates having one aromatic ring in the molecule An active energy ray-curable adhesive composition comprising:

2. 2. The active energy ray-curable adhesive composition according to claim 1, wherein the (meth)acrylate having one aromatic ring in the molecule of d) further has at least one hydroxyl group.

3. 2. The active energy ray-curable adhesive composition according to claim 1, comprising: a) 1 to 30 parts by mass of a urethane (meth)acrylate having two or less (meth)acrylic groups in the molecule, relative to 100 parts by mass of the total amount of curable compounds contained in the adhesive composition.

4. 2. The active energy ray-curable adhesive composition according to claim 1, comprising: b) 15 to 60 parts by mass of a (meth)acrylate having no aromatic ring and a hydroxyl group, relative to 100 parts by mass of the total amount of curable compounds contained in the adhesive composition.

5. 2. The active energy ray-curable adhesive composition according to claim 1, comprising: c) 10 to 60 parts by mass of a (meth)acrylate having no hydroxyl group in the molecule and two or more aromatic rings, relative to 100 parts by mass of the total amount of the curable compounds contained in the adhesive composition.

6. 2. The active energy ray-curable adhesive composition according to claim 1, comprising 3 to 40 parts by mass of d) a (meth)acrylate having one aromatic ring in the molecule, relative to 100 parts by mass of the total amount of curable compounds contained in the adhesive composition.

7. 2. The active energy ray-curable adhesive composition according to claim 1, further comprising 0.5 to 10 parts by mass of a polymerization initiator per 100 parts by mass of the total amount of the curable compounds contained in the adhesive composition.

8. The polymerization initiator has a molar absorption coefficient of 10 L mol in an acetonitrile solvent at a light source wavelength of 400 nm. －１ ・cm －１ The active energy ray-curable adhesive composition according to claim 7 .

9. An optical laminate comprising an adhesive layer which is a cured layer of the active energy ray-curable adhesive composition according to claim 1, and a liquid crystal retardation film adjacent to the adhesive layer.

10. The optical laminate according to claim 9 , further comprising a hard coat layer on the side of the adhesive layer opposite to the liquid crystal retardation film.

11. The optical laminate according to claim 10 , further comprising a polarizing film on the side of the hard coat layer opposite to the adhesive layer.

12. The optical laminate according to claim 11 , wherein the polarizing film is a cured layer of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound and a dichroic dye.

13. The optical laminate according to claim 12 , comprising a polarizing film, an alignment film, a hard coat layer, an adhesive layer, and a liquid crystal retardation film, arranged adjacent to each other in this order.

14. When the in-plane average refractive index of the hard coat layer is n1, the in-plane average refractive index of the liquid crystal retardation film is n2, and the in-plane average refractive index of the adhesive layer is n3, ... following formula is satisfied: |(n1×n2) １／２ -n3| ≦ 0.018 The optical laminate according to claim 10, which satisfies the above.

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