Optical multilayers

Abstract

To provide an optical laminate which remarkably exhibits movement of a dichroic dye from a polarizer, especially, under high temperature and high humidity environment, and accordingly can prevent degradation of a conductive layer due to transition of the dichroic dye contained in the polarizer to a conductive layer under the high temperature and high humidity environment.SOLUTION: An optical laminate includes a polarizer, a first cured product layer, a retardation layer, and an adhesive layer in this order. The polarizer is composed of a polyvinyl alcohol resin containing iodine, the first cured product layer is a cured product of an active energy curable composition, the retardation layer contains at least one retardation expressing layer that is a polymer of a polymerizable liquid crystal compound, the adhesive layer has an amount of iodine after the optical laminate has been stored at a temperature of 80°C and relative humidity of 90% for 250 hours of 900 mg / kg or less, the polarizer and the first cured product layer are brought into direct contact with each other, and the first cured product layer and the retardation layer are brought into direct contact with each other.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an optical laminate. [Background technology]

[0002] BACKGROUND ART In image display devices, a method has been adopted in which an optical laminate having anti-reflection properties is disposed on the viewing side of an image display panel to suppress a decrease in visibility due to reflection of extraneous light.

[0003] A known optical laminate having anti-reflection properties is a circular polarizing plate having a configuration in which a linear polarizing plate having a thermoplastic resin film on both sides of a polarizer and a retardation layer are laminated via an adhesive layer (Patent Document 1). A circular polarizing plate is usually laminated on an image display panel with an additional adhesive layer provided on the side of the retardation layer opposite the linear polarizing plate.

[0004] In recent years, input devices that combine a circular polarizer with an image display panel having a touch panel function have become widespread in image display devices. The image display panel having a touch panel function has a conductive layer formed on its surface, which is made of a transparent conductive film such as an indium tin oxide (ITO) thin film or a metal layer such as aluminum. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-197235 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, with the trend toward thinner image display devices, circular polarizing plates have been proposed, which use a linear polarizing plate with a thermoplastic resin film on only one side of the polarizer. When a linear polarizing plate with such a configuration is laminated on a conductive layer, the dichroic dye (e.g., iodine) contained in the polarizer may migrate to the conductive layer, which may cause malfunctions such as poor sensing. Since the migration of the dichroic dye from the polarizer is particularly noticeable in high-temperature, high-humidity environments, there is a need for an optical laminate that can prevent the deterioration of the conductive layer due to the migration of the dichroic dye contained in the polarizer to the conductive layer, even in high-temperature, high-humidity environments. [Means for solving the problem]

[0007] The present invention provides the following [1] to

[16] . [1] An optical laminate including a polarizer, a first cured product layer, a retardation layer, and a pressure-sensitive adhesive layer in this order, the polarizer is made of a polyvinyl alcohol resin containing iodine, the first cured product layer is a cured product of an active energy-curable composition, the retardation layer includes at least one retardation-exhibiting layer which is a polymer of a polymerizable liquid crystal compound, the pressure-sensitive adhesive layer has an iodine content of 900 mg / kg or less after storing the optical laminate at a temperature of 80°C and a relative humidity of 90% for 250 hours; the polarizer and the first cured product layer are in direct contact with each other, The optical laminate, wherein the first cured product layer and the retardation layer are in direct contact with each other. [2] The retardation layer is a layer including a first polymer layer, a second cured material layer, and a second polymer layer in this order from the first cured material layer side, The optical laminate according to [1], wherein the first polymer layer and the second polymer layer each independently contain a polymer of a polymerizable liquid crystal compound. [3] The optical laminate according to [2], wherein the second cured material layer is an active energy ray-cured material layer. [4] The moisture permeability of the first cured layer at a thickness of 30 μm at a temperature of 80°C and a relative humidity of 90% is 1500 [g / (m 2The optical laminate according to any one of [1] to [3], wherein the maximum operating time is 24 hours). [5] An optical laminate including a polarizer, a first cured product layer, a first retardation layer, a second cured product layer, a second retardation layer, and a pressure-sensitive adhesive layer in this order, the polarizer is made of a polyvinyl alcohol resin containing iodine, the first retardation layer and the second retardation layer each independently include a retardation-exhibiting layer containing a polymer of a polymerizable liquid crystal compound; the first cured material layer and the second cured material layer each independently contain a cured product of an active energy ray-curable composition, the first cured material layer has a storage modulus of 300 MPa or more at a temperature of 80°C; the polarizer and the first cured product layer are in direct contact with each other, The optical laminate, wherein the first cured product layer and the first retardation layer are in direct contact with each other. [6] The optical laminate according to [5], wherein the second cured product layer has a storage modulus of 20 MPa or more at a temperature of 80°C. [7] The optical laminate according to [5] or [6], wherein the storage modulus (E1) of the first cured material layer at a temperature of 80°C is greater than the storage modulus (E2) of the second cured material layer at a temperature of 80°C. [8] The moisture permeability of the first cured layer at a thickness of 30 μm at a temperature of 80°C and a relative humidity of 90% is 1500 [g / (m 2 The optical laminate according to any one of [5] to [7], wherein the maximum operating time is 24 hours). [9] An optical laminate including a polarizer, a first cured product layer, a first retardation layer, a second cured product layer, a second retardation layer, and a pressure-sensitive adhesive layer in this order, the polarizer is made of a polyvinyl alcohol resin containing iodine, the first retardation layer and the second retardation layer each independently include a retardation-exhibiting layer that is a polymer of a polymerizable liquid crystal compound, the first cured material layer and the second cured material layer are each independently a cured product of an active energy ray-curable composition, the glass transition temperature (Tg1) of the first cured material layer is higher than 60°C; the polarizer and the first cured product layer are in direct contact with each other, The optical laminate, wherein the first cured product layer and the first retardation layer are in direct contact with each other.

[10] The optical laminate according to [9], wherein the glass transition temperature (Tg2) of the second cured product layer is 40°C or higher.

[11] The optical laminate according to [9] or

[10] , wherein the glass transition temperature (Tg1) of the first cured product layer is higher than the glass transition temperature (Tg2) of the second cured product layer.

[12] The moisture permeability of the first cured layer at a thickness of 30 μm at a temperature of 80°C and a relative humidity of 90% is 1500 [g / (m 2 The optical laminate according to any one of [9] to

[11] , wherein the maximum operating time is 24 hours).

[13] An optical laminate including a polarizer, a first cured product layer, a retardation layer, and a pressure-sensitive adhesive layer in this order, the polarizer is made of a polyvinyl alcohol resin containing iodine, the retardation layer includes a retardation-exhibiting layer containing a polymer of a polymerizable liquid crystal compound, the first cured product layer is a cured product of an active energy-curable composition, The active energy ray-curable composition is a composition containing an epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule, and is an optical layered body.

[14] An optical laminate including a polarizer, a first cured product layer, a first retardation layer, a second cured product layer, a second retardation layer, and a pressure-sensitive adhesive layer in this order, the polarizer is made of a polyvinyl alcohol resin containing iodine, the first cured material layer is a cured material of an active energy curable composition, The active energy ray-curable composition is a composition containing an epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule, and is an optical layered body.

[15] An active energy ray-curable composition comprising a curable component (A) and a photopolymerization initiator (B), the curable component (A) contains a polyfunctional oxetane compound (A5-1) and an epoxy compound (A2-1) containing a tricyclic fused ring and a diglycidyl ether group in the molecule; an active energy ray-curable composition, wherein the content of the polyfunctional oxetane compound (A5-1) is greater than the content of the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule.

[16] The active energy ray-curable composition according to

[15] , wherein the content ratio (mass ratio) of the polyfunctional oxetane compound (A5-1) to the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule is the polyfunctional oxetane compound (A5-1) / the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule = 1.5 / 1 to 5 / 1. [Effects of the Invention]

[0008] The optical laminate of the present invention is a laminate including a linear polarizing plate and a retardation layer, and when laminated with a conductive layer via a pressure-sensitive adhesive layer, corrosion of the conductive layer can be suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view showing a laminate of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing a retardation layer. [Figure 3] 3A to 3C are schematic cross-sectional views showing an example of each manufacturing step in a method for manufacturing a laminate. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In all of the drawings, the scales of the components are appropriately adjusted to make them easier to understand, and the scales of the components shown in the drawings do not necessarily match the scales of the actual components.

[0011] <Optical laminate> The optical laminate of the present invention will be described with reference to FIG. 1. The optical laminate 100 shown in FIG. 1 includes a polarizer 13, a first cured product layer 14, a retardation layer 20, and a pressure-sensitive adhesive layer 70, in this order. The polarizer 13 and the first cured product layer 14 are in direct contact with each other, and the first cured product layer 14 and the retardation layer 20 are in direct contact with each other. A thermoplastic resin film 11 may be laminated on the side of the polarizer 13 opposite to the first cured product layer 14, via an adhesive layer 12. It is also preferable that the retardation layer 20 and the pressure-sensitive adhesive layer 70 are in direct contact with each other. In the present invention, a configuration including the thermoplastic resin film 11, the adhesive layer 12, and the polarizer 13 in this order is referred to as a linear polarizing plate 10.

[0012] Although not shown, a known surface treatment layer such as a hard coat layer or an antireflection layer may be provided on the thermoplastic resin film 11 on the side opposite to the adhesive layer 12. The thickness of the optical laminate 100 may be, for example, 2 μm or more and 100 μm or less, and preferably 2 μm or more and 80 μm or less.

[0013] The optical laminate 100 may be elongated or sheet-like. When the optical laminate 100 is sheet-like, the shape of the optical laminate 100 in a planar view may be substantially rectangular. A planar view refers to a view from the thickness direction of the optical laminate 100. A substantially rectangular shape may mean that at least one of the four corners (corners) is cut or rounded to form an obtuse angle, that a portion of the end face in a planar view may have a recessed portion (notch) recessed in the in-plane direction, or that a portion of the shape in a planar view may have a hole cut out in the shape of a circle, an ellipse, a polygon, or a combination thereof.

[0014] There are no particular limitations on the size of the optical laminate 100. When the optical laminate 100 is in a sheet-like shape and is substantially rectangular, the length of the long side is preferably 6 cm or more and 35 cm or less, and more preferably 10 cm or more and 30 cm or less, and the length of the short side is preferably 5 cm or more and 30 cm or less, and more preferably 6 cm or more and 25 cm or less.

[0015] (thermoplastic resin film) The thermoplastic resin film 11 can be disposed on the viewing side of the laminate. The thermoplastic resin film 11 can function as a protective film for protecting the polarizer 13. Although not shown, the thermoplastic resin films may be disposed on both sides of the polarizer, but from the viewpoint of reducing the thickness of the laminate, the thermoplastic resin film is preferably disposed on one side of the polarizer, and more preferably disposed only on the viewing side of the laminate.

[0016] The material of the thermoplastic resin film 11 is not particularly limited, but examples thereof include films known in the art, such as cyclic polyolefin resin films, cellulose acetate resin films made of resins such as triacetyl cellulose and diacetyl cellulose, polyester resin films made of resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polycarbonate resin films, (meth)acrylic resin films, and polypropylene resin films. From the viewpoint of achieving a thinner film, the thickness of the thermoplastic resin film 11 is typically 300 μm or less, preferably 200 μm or less, and more preferably 50 μm or less, and typically 5 μm or more, and preferably 20 μm or more. Furthermore, the thermoplastic resin film 11 may or may not have a retardation.

[0017] The thermoplastic resin film 11 may contain, as needed, one or more additives such as rubber particles, lubricants, fluorescent whitening agents, dispersants, heat stabilizers, light stabilizers, ultraviolet absorbers, infrared absorbers, antistatic agents, antioxidants, etc. From the viewpoint of durability (light resistance) of the laminate, the thermoplastic resin film 11 preferably contains an ultraviolet absorber.

[0018] The thermoplastic resin film 11 has a moisture permeability of 100 g / m 2 24 hours or less is preferable, 30 g / m 2 It is more preferable that it be 24 hours or less.

[0019] (adhesive layer) The adhesive layer 12 is a layer formed from an adhesive for bonding the thermoplastic resin film 11 and the polarizer 13 together. The adhesive may be any adhesive that exhibits adhesive strength to both of them, and examples thereof include a water-based adhesive in which an adhesive component is dissolved or dispersed in water, and an active energy ray-curable adhesive composition containing an active energy ray-curable compound.

[0020] The aqueous adhesive composition may be, for example, a composition that uses a polyvinyl alcohol resin or a urethane resin as a main component and that contains a crosslinking agent or a curable compound such as an isocyanate compound or an epoxy compound to improve adhesion.

[0021] When a polyvinyl alcohol resin is used as the main component of an aqueous adhesive composition, modified polyvinyl alcohol resins such as partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, and amino group-modified polyvinyl alcohol may be used. The aqueous adhesive composition preferably contains acetoacetyl group-modified polyvinyl alcohol. An aqueous solution of such a polyvinyl alcohol resin is used as the aqueous adhesive, and the concentration of the polyvinyl alcohol resin in the aqueous adhesive is usually 1 part by mass to 10 parts by mass, preferably 1 part by mass to 5 parts by mass, per 100 parts by mass of water.

[0022] To improve adhesion, aqueous adhesive compositions composed of aqueous solutions of polyvinyl alcohol-based resins can be blended with curing compounds such as polyaldehydes, water-soluble epoxy resins, melamine-based compounds, zirconia-based compounds, and zinc compounds. Examples of water-soluble epoxy resins include water-soluble polyamide epoxy resins obtained by reacting epichlorohydrin with polyamide polyamines obtained by reacting polyalkylene polyamines such as diethylenetriamine or triethylenetetramine with dicarboxylic acids such as adipic acid. Commercially available polyamide epoxy resins include "Sumirez Resin 650" and "Sumirez Resin 675" sold by Sumika Chemtex Co., Ltd. and "WS-525" sold by Nippon PMC Corporation. When a water-soluble epoxy resin is blended, the amount added is typically 1 part by weight to 100 parts by weight, preferably 1 part by weight to 50 parts by weight, per 100 parts by weight of the polyvinyl alcohol-based resin.

[0023] Furthermore, when a urethane resin is used as the main component of an aqueous adhesive composition, it is effective to use a polyester ionomer urethane resin as the main component of the aqueous adhesive composition. The polyester ionomer urethane resin referred to here is a urethane resin having a polyester skeleton, into which a small amount of an ionic component (hydrophilic component) has been introduced. Such ionomer urethane resins can be directly emulsified in water to form an emulsion without the use of an emulsifier, making them suitable for use as aqueous adhesives. When using a polyester ionomer urethane resin, it is effective to incorporate a water-soluble epoxy compound as a crosslinking agent. The use of polyester ionomer urethane resins as adhesives for polarizing plates is described, for example, in JP-A Nos. 2005-70140 and 2005-208456.

[0024] The water-based adhesive composition may contain fillers, flow control agents, antifoaming agents, leveling agents, pigments, organic solvents, and the like.

[0025] The aqueous adhesive composition is usually used in a form in which each component is dissolved in water. The water-insoluble components contained in the aqueous adhesive composition may be in a dispersed state in the system. The aqueous adhesive composition may be applied to one surface of a polarizer and dried to form a transparent adhesive.

[0026] The aqueous adhesive composition is applied to one or both sides of a polarizer or a thermoplastic resin film, and after bonding them together, the two are heated to evaporate the water and promote a thermal crosslinking reaction, thereby sufficiently bonding the two together. A laminate in which a polarizer 13 and a thermoplastic resin film 11 are laminated with an adhesive layer 12 interposed therebetween is also referred to as a linear polarizing plate 10.

[0027] The active energy ray-curable adhesive composition is described below in relation to the first cured material layer 14. The active energy ray-curable adhesive composition used in the adhesive layer 12 may contain neither a photosensitizer nor a photosensitizing aid. In addition, the active energy ray-curable adhesive composition may be the same as or different from the active energy ray-curable adhesive composition contained in the first cured material layer 14.

[0028] The thickness of the first adhesive layer 12 may be, for example, 20 μm or less, preferably 10 μm or less, and more preferably 5 μm or less. The thickness of the first adhesive layer 12 may be, for example, 0.1 μm or more.

[0029] (polarizer) The polarizer 13 can be an absorption-type polarizer that absorbs linearly polarized light having a vibration plane parallel to its absorption axis and transmits linearly polarized light having a vibration plane perpendicular to the absorption axis (parallel to its transmission axis). A suitable example of the polarizer 13 is a polarizer in which a dichroic dye is adsorbed and aligned on a uniaxially stretched polyvinyl alcohol-based resin film. The polarizer 13 can be produced, for example, by a method including the steps of: uniaxially stretching a polyvinyl alcohol-based resin film; dyeing the polyvinyl alcohol-based resin film with the dichroic dye to adsorb it; treating the polyvinyl alcohol-based resin film with a crosslinking liquid such as a boric acid aqueous solution; and washing the film with water after the crosslinking liquid treatment.

[0030] The polyvinyl alcohol resin may be a saponified polyvinyl acetate resin. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate with other monomers copolymerizable with vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth)acrylamides having an ammonium group.

[0031] In this specification, "(meth)acrylic" means at least one selected from acrylic and methacrylic. The same applies to "(meth)acryloyl", "(meth)acrylate", etc.

[0032] The saponification degree of the polyvinyl alcohol resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes can also be used. The average polymerization degree of the polyvinyl alcohol resin is usually 1,000 to 10,000, preferably 1,500 to 5,000. The average polymerization degree of the polyvinyl alcohol resin can be determined in accordance with JIS K 6726.

[0033] Such a polyvinyl alcohol-based resin is used as a raw film for a polarizer. The method for forming the polyvinyl alcohol-based resin is not particularly limited, and a known method is used. The thickness of the polyvinyl alcohol-based raw film is not particularly limited, but may be, for example, 5 μm or more and 85 μm or less.

[0034] The uniaxial stretching of the polyvinyl alcohol-based resin film can be carried out before, simultaneously with, or after dyeing with a dichroic dye. When the uniaxial stretching is carried out after dyeing, the uniaxial stretching may be carried out before or during a crosslinking treatment. Alternatively, the uniaxial stretching may be carried out in a plurality of these stages.

[0035] In the uniaxial stretching, the film may be stretched uniaxially between rolls having different peripheral speeds, or may be stretched uniaxially using a heated roll. The uniaxial stretching may be dry stretching in which stretching is performed in the atmosphere, or wet stretching in which the polyvinyl alcohol-based resin film is stretched in a swollen state using a solvent or water. The stretching ratio is usually 3 to 8 times.

[0036] A method for dyeing a polyvinyl alcohol-based resin film with a dichroic dye is, for example, to immerse the film in an aqueous solution containing the dichroic dye. The dichroic dye may be iodine or a dichroic organic dye. It is preferable to immerse the polyvinyl alcohol-based resin film in water before dyeing.

[0037] As a crosslinking treatment after dyeing with a dichroic dye, a method of immersing the dyed polyvinyl alcohol resin film in an aqueous solution containing boric acid is usually adopted. When iodine is used as the dichroic dye, the aqueous solution containing boric acid preferably contains potassium iodide.

[0038] The thickness of the polarizer 13 is usually 30 μm or less, preferably 28 μm or less, more preferably 20 μm or less, still more preferably 15 μm or less, and particularly preferably 10 μm or less. The thickness of the polarizer 13 is usually 2 μm or more, and preferably 3 μm or more.

[0039] (1st cured material layer) The first cured material layer 14 is disposed between the polarizer 13 and the retardation layer 20 in order to bond the polarizer 13 and the retardation layer 20 together (to bond the linear polarizer and a retardation laminate described later). The first cured material layer 14 is a cured product of an active energy ray-curable adhesive composition. By forming the first cured material layer 14 from a cured product of an active energy ray-curable adhesive composition, migration of iodine contained in the polarizer is suppressed compared to when a pressure-sensitive adhesive layer is used, and corrosion of the conductive layer when laminated with the polarizer can be suppressed. In the present invention, the corrosion resistance is evaluated according to the evaluation method described in the Examples section below.

[0040] The thickness of the first cured material layer 14 may be, for example, 10 μm or less, preferably 5 μm or less, more preferably 4 μm or less, and even more preferably 3 μm or less. The thickness of the first cured material layer 14 may be, for example, 0.5 μm or more, and preferably 1 μm or more.

[0041] (Active energy ray-curable adhesive composition) The active energy ray-curable adhesive composition may be any adhesive that is cured by irradiation with active energy rays, and may be, for example, a cationically polymerizable adhesive composition or a radically polymerizable adhesive composition. The active energy ray-curable adhesive composition is preferably a cationically polymerizable adhesive composition.

[0042] (Cationically polymerizable adhesive composition) The cationically polymerizable adhesive composition contains a curable component (A) and a photocationic polymerization initiator (B). The curable component (A) is a component that can be cured by cationic polymerization upon irradiation with active energy rays. The adhesive strength is developed by the polymerization and curing of the curable component (A).

[0043] (Curable component (A)) The curable component (A) may contain at least one of an alicyclic epoxy compound (A1) and a polyfunctional aliphatic epoxy compound (A2). The curable component (A) may further contain at least one selected from the group consisting of a monofunctional epoxy compound (A3), a polyfunctional aromatic epoxy compound (A4), and an oxetane compound (A5).

[0044] When the curable component (A) contains an alicyclic epoxy compound (A1), the content of the alicyclic epoxy compound (A1) may be, for example, 5 parts by mass or more and 90 parts by mass or less, and preferably 10 parts by mass or more and 80 parts by mass or less, per 100 parts by mass of the curable component (A). When the curable component (A) contains a polyfunctional aliphatic epoxy compound (A2), the content of the polyfunctional aliphatic epoxy compound (A2) may be, for example, 1 part by mass or more and 50 parts by mass or less, and preferably 5 parts by mass or more and 45 parts by mass or less, per 100 parts by mass of the curable component (A). When the curable component (A) contains a monofunctional epoxy compound (A3), the content of the monofunctional epoxy compound (A3) may be, for example, 1 part by mass or more and 20 parts by mass or less, and preferably 1 part by mass or more and 15 parts by mass or less, per 100 parts by mass of the curable component (A). When the curable component (A) contains a polyfunctional aromatic epoxy compound (A4), the content of the polyfunctional aromatic epoxy compound (A4) may be, for example, 1 part by mass or more and 60 parts by mass or less, and preferably 1 part by mass or more and 50 parts by mass or less, per 100 parts by mass of the curable component (A). When the curable component (A) contains an oxetane compound (A5), the content of the oxetane compound (A5) may be, for example, 5 parts by mass or more and 90 parts by mass or less, and preferably 10 parts by mass or more and 80 parts by mass or less, per 100 parts by mass of the curable component (A).

[0045] The active energy ray-curable adhesive composition preferably does not contain a solvent. Each component will be described in detail below.

[0046] (Alicyclic epoxy compound (A1)) The alicyclic epoxy compound (A1) is a compound having one or more alicyclic epoxy groups. The alicyclic epoxy compound (A1) may further have an epoxy group other than the alicyclic epoxy group, so long as it is a compound having one or more alicyclic epoxy groups. In this specification, the alicyclic epoxy group means an epoxy group bonded to an alicyclic ring, and refers to the bridging oxygen atom -O- in the structure represented by the following formula (a):

[0047] [ka]

[0048] In the above formula (a), m is an integer of 2 to 5. (CH2) in the above formula (a) m A compound in which one or more hydrogen atoms have been removed from the (CH2) group and the resulting group is bonded to another chemical structure can be an alicyclic epoxy compound (A1). m One or more hydrogen atoms in the alicyclic epoxy compound (A1) may be appropriately substituted with a linear alkyl group such as a methyl group or an ethyl group. The curing rate of the active energy ray-curable adhesive composition can be adjusted by the alicyclic epoxy compound (A1).

[0049] Specific examples of the alicyclic epoxy compound (A1) include 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 1,2-epoxy-4-vinylcyclohexane, 1,2-epoxy-1-methyl-4-(1-methylepoxyethyl)cyclohexane, 3,4-epoxycyclohexylmethyl methacrylate, 4-(1,2-epoxyethyl)-1,2-epoxycyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, ethylene bis(3,4-epoxycyclohexanecarboxylate), oxydiethylene bis(3,4-epoxycyclohexanecarboxylate), 1,4-cyclohexanedimethyl bis(3,4-epoxycyclohexanecarboxylate), and 3-(3,4-epoxycyclohexylmethoxycarbonyl)propyl 3,4-epoxycyclohexanecarboxylate.

[0050] Among the alicyclic epoxy compounds (A1), 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate is preferably used because it has suitable curability and is available at a relatively low cost. As the alicyclic epoxy compound (A1), one type of alicyclic epoxy compound may be used alone, or different types may be used in combination.

[0051] The alicyclic epoxy compound (A1) can be a commercially available product, and examples thereof include the "Celloxide (registered trademark)" series and "Cyclomer (registered trademark)" sold by Daicel Corporation, and the "Cyracure UVR" series sold by The Dow Chemical Company, each under its trade name.

[0052] (Polyfunctional aliphatic epoxy compound (A2)) The polyfunctional aliphatic epoxy compound (A2) is a compound having two or more epoxy groups and no aromatic ring. However, the polyfunctional aliphatic epoxy compound (A2) in this specification does not include compounds having an alicyclic epoxy group, which are included in the alicyclic epoxy compound (A1). The polyfunctional aliphatic epoxy compound (A2) can adjust the adhesion of the cured adhesive layer.

[0053] The polyfunctional aliphatic epoxy compound (A2) is more preferably an aliphatic diepoxy compound represented by the following formula (b): By including an aliphatic diepoxy compound represented by the following formula (b) as the polyfunctional aliphatic epoxy compound (A2), an active energy ray-curable adhesive having low viscosity and easy application can be obtained.

[0054] [ka]

[0055] In formula (b), Z is an alkylene group having 1 to 9 carbon atoms, an alkylidene group having 3 or 4 carbon atoms, a divalent alicyclic hydrocarbon group, or a group represented by the formula -C m H 2m -Z 1 -Cn H 2n - is a divalent group represented by the formula -C m H 2m -Z 1 -C n H 2n -Medium, -Z 1 - represents -O-, -CO-O-, -O-CO-, -SO2-, -SO- or CO-, and m and n each independently represent an integer of 1 or more, and the sum of m and n is 9 or less.

[0056] The divalent alicyclic hydrocarbon group may be, for example, a divalent alicyclic hydrocarbon group having 4 to 16 carbon atoms, and examples thereof include a divalent group represented by the following formula (b-1) or a divalent group represented by the following formula (b-2).

[0057] [ka] [ka]

[0058] Specific examples of the compound represented by formula (b) include diglycidyl ethers of alkanediols, diglycidyl ethers of oligoalkylene glycols having up to about four repeating groups, and diglycidyl ethers of alicyclic diols.

[0059] Examples of diols (glycols) capable of forming the compound represented by the formula (b) include ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-di Examples of the diol include alkanediols such as ethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, and 1,9-nonanediol; oligoalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, and dipropylene glycol; and alicyclic diols such as cyclohexanediol, cyclohexanedimethanol, and dicyclopentadienedimethanol.

[0060] In the present invention, the polyfunctional aliphatic epoxy compound (A2) is preferably 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, or dicyclopentadiene methanol diglycidyl ether, from the viewpoint of obtaining an active energy ray-curable adhesive composition that has low viscosity and is easy to apply. As the polyfunctional aliphatic epoxy compound (A2), one type of aliphatic epoxy compound may be used alone, or different types may be used in combination.

[0061] In one embodiment of the present invention, the polyfunctional aliphatic epoxy compound (A2) is preferably an epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule. The tricyclic fused ring is not particularly limited as long as it is a fused ring consisting of three rings, but is preferably a fused ring consisting of an aliphatic ring. Examples of the tricyclic fused ring include an adamantane ring, a tricyclodecane ring, a dicyclopentadiene ring, and a tricyclodecane ring. Examples of the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule include compounds represented by the following formula (c-1). [ka] [In formula (c-1), X1 represents a tricyclic fused ring, and Z 2 and Z 3 each independently represents a single bond or a divalent hydrocarbon group. Examples of the tricyclic fused ring represented by X1 include an adamantane ring, a tricyclodecane ring, a dicyclopentadiene ring, and a tricyclodecane ring, and a tricyclodecane ring is preferred. Z 2 and Z 3 Examples of the divalent hydrocarbon group represented by the formula include alkanediyl groups having 1 to 8 carbon atoms, such as a methylene group, an ethylene group, and a propanediyl group; and aromatic hydrocarbon groups having 6 to 10 carbon atoms, such as a phenylene group. Z 2 and Z 3 are each independently preferably a divalent hydrocarbon group, more preferably an alkanediyl group having 1 to 8 carbon atoms, even more preferably an alkanediyl group having 1 to 4 carbon atoms, and particularly preferably a methylene group.

[0062] The polyfunctional aliphatic epoxy compound (A2) may be a commercially available product, such as "EP-4088S" (both manufactured by ADEKA Corporation), "EHPE3150" (both manufactured by Daicel Corporation), "EX-211L", or "EX-212L" (all manufactured by Nagase ChemteX Corporation).

[0063] (Monofunctional epoxy compound (A3)) The monofunctional epoxy compound (A3) is a compound having one epoxy group. However, the monofunctional epoxy compound (A3) referred to in this specification does not include compounds having an alicyclic epoxy group in the molecule, which are included in the alicyclic epoxy compound (A1). The monofunctional epoxy compound (A3) may or may not have an aromatic ring in the molecule. The viscosity of the active energy ray-curable adhesive composition can be adjusted by the monofunctional epoxy compound (A3).

[0064] Examples of the monofunctional epoxy compound (A3) having an aromatic ring include monoglycidyl ethers of monohydric phenols such as phenol, cresol, and butylphenol, or bisphenol derivatives such as bisphenol A and bisphenol F, or alkylene oxide adducts thereof; epoxy novolac resins; monoglycidyl ethers of aromatic compounds having two or more phenolic hydroxyl groups such as resorcinol, hydroquinone, and catechol; monoglycidyl ethers of aromatic compounds having two or more alcoholic hydroxyl groups such as benzenedimethanol, benzenediethanol, and benzenedibutanol; monoglycidyl esters of polybasic aromatic acid compounds having two or more carboxyl groups such as phthalic acid, terephthalic acid, and trimellitic acid; glycidyl esters of benzoic acid, and monoglycidyl esters of toluic acid and naphthoic acid.

[0065] Examples of the monofunctional epoxy compound (A3) not having an aromatic ring include glycidyl ethers of aliphatic alcohols and glycidyl esters of alkylcarboxylic acids, and specific examples thereof include allyl glycidyl ether, butyl glycidyl ether, sec-butylphenyl glycidyl ether, 2-ethylhexyl glycidyl ether, mixed alkyl glycidyl ethers having 12 and 13 carbon atoms, glycidyl ethers of alcohols, monoglycidyl ethers of higher aliphatic alcohols, glycidyl esters of higher fatty acids, etc. As the monofunctional epoxy compound (A3), one type of monofunctional epoxy compound may be used alone, or different types may be used in combination.

[0066] The monofunctional epoxy compound (A3) can be a commercially available product, such as "EX-142", "EX-146", "EX-147", or "EX-121" (all manufactured by Nagase ChemteX Corporation).

[0067] (Polyfunctional aromatic epoxy compound (A4)) The polyfunctional aromatic epoxy compound (A4) is a compound having two or more epoxy groups and an aromatic ring, provided that the polyfunctional aromatic epoxy compound (A4) in this specification does not include compounds that have an alicyclic epoxy group in the molecule, which are included in the alicyclic epoxy compound (A1).

[0068] Specific examples of the polyfunctional aromatic epoxy compound (A4) include polyglycidyl ethers of naphthalene or naphthalene derivatives (also referred to as "naphthalene-type epoxy compounds"); polyglycidyl ethers of bisphenol derivatives such as bisphenol A and bisphenol F (also referred to as "bisphenol A-type epoxy compounds" and "bisphenol F-type epoxy compounds"); epoxy novolac resins; polyglycidyl ethers of aromatic compounds having two or more phenolic hydroxyl groups such as resorcinol, hydroquinone, and catechol; benzenediols; Examples of the polyfunctional aromatic epoxy compound (A4) include polyglycidyl ethers of aromatic compounds having two or more alcoholic hydroxyl groups, such as methanol, benzenediethanol, and benzenedibutanol; polyglycidyl esters of polybasic aromatic compounds having two or more carboxyl groups, such as phthalic acid, terephthalic acid, and trimellitic acid; glycidyl esters of benzoic acid, polyglycidyl esters of toluic acid and naphthoic acid; styrene oxides, such as styrene oxide, alkylated styrene oxide, and epoxidized vinylnaphthalene, or diepoxidized divinylbenzene. The polyfunctional aromatic epoxy compound (A4) may be used alone or in combination with a plurality of different compounds.

[0069] The polyfunctional aromatic epoxy compound (A4) may be a commercially available product, such as "Denacol EX-201", "Denacol EX-711" and "Denacol EX-721" (all manufactured by Nagase ChemteX Corporation); "Oxol EG-280" and "Oxol CG-400" (all manufactured by Osaka Gas Chemicals Co., Ltd.); "EXA-80CRP" and "HP4032D" (all manufactured by DIC Corporation); "jER828" and "j ER828EL" (all manufactured by Mitsubishi Chemical Corporation); "ADEKA RESIN EP-4100", "ADEKA RESIN EP-4100G", "ADEKA RESIN EP-4100E", "ADEKA RESIN EP-4100L", "ADEKA RESIN EP-4100TX", "ADEKA RESIN EP-4000", "ADEKA RESIN EP-4005", "ADEKA RESIN EP-4901", "ADEKA RESIN EP-4901E" (all manufactured by ADEKA Corporation).

[0070] (Oxetane compound (A5)) In this specification, the oxetane compound (A5) is a compound having an oxetanyl group, and may be an aliphatic compound, an alicyclic compound, or an aromatic compound. The oxetane compound (A5) in this specification is a compound that does not have an epoxy group. The oxetane compound (A5) can adjust the curing rate and viscosity of the active energy ray-curable adhesive composition and can also improve the reactivity.

[0071] The oxetane compound (A5) may be a monofunctional oxetane compound having one oxetanyl group, or a polyfunctional oxetane compound (A5-1) having two or more oxetanyl groups. The oxetane compound (A5) is preferably a polyfunctional oxetane compound (A5-1), and more preferably a bifunctional oxetane compound.

[0072] Specific examples of the oxetane compound (A5) include 3,7-bis(3-oxetanyl)-5-oxa-nonane, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, 1,2-bis[(3-ethyl-3-oxetanylmethoxy)methyl]ethane, 1,3-bis[(3-ethyl-3-oxetanylmethoxy)methyl]propane, ethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, triethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, tetraethylene glycol bis(3-ethyl-3-oxetanyl) Examples of the oxetane compound (A5) include 3-ethyl-3-oxetanylmethyl ether, 4-bis(3-ethyl-3-oxetanylmethoxy)butane, 1,6-bis(3-ethyl-3-oxetanylmethoxy)hexane, 3-ethyl-3-(phenoxy)methyloxetane, 3-ethyl-3-(cyclohexyloxymethyl)oxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(chloromethyl)oxetane, 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, and xylylenebisoxetane. As the oxetane compound (A5), one type of oxetane compound may be used alone, or different types may be used in combination.

[0073] As the oxetane compound (A5), commercially available products can be used, and examples thereof include the "Aron Oxetane (registered trademark)" series sold by Toagosei Co., Ltd. and the "ETERNACOLL (registered trademark)" series sold by Ube Industries, Ltd.

[0074] The above-mentioned curable components [alicyclic epoxy compound (A1), polyfunctional aliphatic epoxy compound (A2), monofunctional epoxy compound (A3), polyfunctional aromatic epoxy compound (A4), and oxetane compound (A5)] are preferably not diluted with an organic solvent or the like so that the active energy ray-curable adhesive composition is solvent-free.

[0075] The above-mentioned curable component is usually liquid at room temperature, has appropriate fluidity even in the absence of a solvent, and is selected to provide appropriate adhesive strength. The active energy ray-curable adhesive composition containing a suitable photocationic polymerization initiator can eliminate the need for a drying facility for evaporating the solvent in the step of adhering a linear polarizing plate and a retardation layer laminate in a manufacturing facility for an optical laminate. Furthermore, irradiation with an appropriate amount of active energy rays can accelerate the curing rate, thereby improving the production rate.

[0076] (Other curing components) The curable component (A) contained in the active energy ray-curable adhesive composition is not limited to the above-described curable components, and may include a cationically polymerizable curable component other than the above-described cationically polymerizable curable components, and a radically polymerizable curable component.

[0077] (Radical polymerizable curing component) The radical polymerizable compound refers to a compound or oligomer that undergoes a radical polymerization reaction and hardens when exposed to active energy rays such as ultraviolet light, visible light, electron beams, or X-rays or when heated, and specifically includes a compound having an ethylenically unsaturated bond. Examples of the compound having an ethylenically unsaturated bond include (meth)acrylic compounds having one or more (meth)acryloyl groups in the molecule, as well as vinyl compounds such as styrene, styrene sulfonic acid, vinyl acetate, vinyl propionate, and N-vinyl-2-pyrrolidone. Among these, the preferred radical polymerizable compound is a (meth)acrylic compound.

[0078] Examples of (meth)acrylic compounds include (meth)acryloyl group-containing compounds such as (meth)acrylate monomers, (meth)acrylamide monomers, and (meth)acrylic oligomers having at least two (meth)acryloyl groups in the molecule, which are obtained by reacting two or more functional group-containing compounds. The (meth)acrylic oligomer is preferably a (meth)acrylate oligomer having at least two (meth)acryloyloxy groups in the molecule. The (meth)acrylic compounds may be used alone or in combination of two or more.

[0079] Examples of the (meth)acrylate monomer include a monofunctional (meth)acrylate monomer having one (meth)acryloyloxy group in the molecule, a bifunctional (meth)acrylate monomer having two (meth)acryloyloxy groups in the molecule, and a polyfunctional (meth)acrylate monomer having three or more (meth)acryloyloxy groups in the molecule.

[0080] An example of a monofunctional (meth)acrylate monomer is alkyl(meth)acrylate. In alkyl(meth)acrylate, the alkyl group may be linear or branched as long as it has three or more carbon atoms. Specific examples of alkyl(meth)acrylate include methyl(meth)acrylate, ethyl(meth)acrylate, isopropyl(meth)acrylate, butyl(meth)acrylate, isobutyl(meth)acrylate, t-butyl(meth)acrylate, and 2-ethylhexyl(meth)acrylate. In addition, aralkyl (meth)acrylates such as benzyl (meth)acrylate; (meth)acrylates of terpene alcohols such as isobornyl (meth)acrylate; (meth)acrylates having a tetrahydrofurfuryl structure such as tetrahydrofurfuryl (meth)acrylate; (meth)acrylates having a cycloalkyl group in the alkyl group moiety such as cyclohexyl (meth)acrylate, cyclohexylmethyl methacrylate, dicyclopentanyl acrylate, dicyclopentenyl (meth)acrylate, and 1,4-cyclohexanedimethanol monoacrylate; aminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate; and (meth)acrylates having an ether bond in the alkyl group moiety such as 2-phenoxyethyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate, and phenoxypolyethylene glycol (meth)acrylate can also be used as monofunctional (meth)acrylate monomers.

[0081] Furthermore, monofunctional (meth)acrylates having a hydroxyl group in the alkyl moiety and monofunctional (meth)acrylates having a carboxyl group in the alkyl moiety can also be used. Specific examples of monofunctional (meth)acrylates having a hydroxyl group in the alkyl moiety include 2-hydroxyethyl (meth)acrylate, 2- or 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, trimethylolpropane mono(meth)acrylate, and pentaerythritol mono(meth)acrylate. Specific examples of monofunctional (meth)acrylates having a carboxyl group in the alkyl moiety include 2-carboxyethyl (meth)acrylate, ω-carboxy-polycaprolactone (n≈2) mono(meth)acrylate, 1-[2-(meth)acryloyloxyethyl]phthalic acid, 1-[2-(meth)acryloyloxyethyl]hexahydrophthalic acid, 1-[2-(meth)acryloyloxyethyl]succinic acid, 4-[2-(meth)acryloyloxyethyl]trimellitic acid, and N-(meth)acryloyloxy-N',N'-dicarboxymethyl-p-phenylenediamine.

[0082] The (meth)acrylamide monomer is preferably a (meth)acrylamide having a substituent at the N-position, and a typical example of the N-position substituent is an alkyl group, but it may also form a ring together with the nitrogen atom of the (meth)acrylamide, and this ring may have an oxygen atom as a ring member in addition to the carbon atom and the nitrogen atom of the (meth)acrylamide. Furthermore, a substituent such as an alkyl or oxo (=O) may be bonded to the carbon atom constituting the ring.

[0083] Specific examples of N-substituted (meth)acrylamides include N-alkyl(meth)acrylamides such as N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, Nn-butyl(meth)acrylamide, Nt-butyl(meth)acrylamide, and N-hexyl(meth)acrylamide; and N,N-dialkyl(meth)acrylamides such as N,N-dimethyl(meth)acrylamide and N,N-diethyl(meth)acrylamide. The N-substituent may also be an alkyl group having a hydroxyl group, examples of which include N-hydroxymethyl(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, and N-(2-hydroxypropyl)(meth)acrylamide. Furthermore, specific examples of the N-substituted (meth)acrylamides forming the above-mentioned 5- or 6-membered ring include N-acryloylpyrrolidine, 3-acryloyl-2-oxazolidinone, 4-acryloylmorpholine, N-acryloylpiperidine, and N-methacryloylpiperidine.

[0084] Examples of bifunctional (meth)acrylate monomers include alkylene glycol di(meth)acrylate, polyoxyalkylene glycol di(meth)acrylate, halogen-substituted alkylene glycol di(meth)acrylate, di(meth)acrylate of aliphatic polyol, di(meth)acrylate of hydrogenated dicyclopentadiene or tricyclodecane dialkanol, di(meth)acrylate of dioxane glycol or dioxane dialkanol, di(meth)acrylate of alkylene oxide adduct of bisphenol A or bisphenol F, and epoxy di(meth)acrylate of bisphenol A or bisphenol F.

[0085] More specific examples of bifunctional (meth)acrylate monomers include ethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol di(meth)acrylate, ditrimethylolpropane di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, di(meth)acrylate, silicone di(meth)acrylate, di(meth)acrylate of hydroxypivalic acid neopentyl glycol ester, 2,2-bis[4-(meth)acryloyloxyethoxyethoxyphenyl]propane, 2,2-bis[4-(meth)acryloyloxyethoxyethoxycyclohexyl]propane, hydrogenated dicyclopentadienyl di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, 1,3-dioxane-2,5-diyl di(meth)acrylate [also known as dioxane glycol di(meth)acrylate], di(meth)acrylate of an acetal compound of hydroxypivalaldehyde and trimethylolpropane [chemical name: 2-(2-hydroxy-1,1-dimethylethyl)-5-ethyl-5-hydroxymethyl-1,3-dioxane], tris(hydroxyethyl)isocyanurate di(meth)acrylate, etc.

[0086] Examples of trifunctional or higher polyfunctional (meth)acrylate monomers include glycerin tri(meth)acrylate, alkoxylated glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol tetra(meth)acrylate. Representative examples include poly(meth)acrylates of trifunctional or higher aliphatic polyols such as taerythritol hexa(meth)acrylate, and other examples include poly(meth)acrylates of trifunctional or higher halogen-substituted polyols, tri(meth)acrylates of alkylene oxide adducts of glycerin, tri(meth)acrylates of alkylene oxide adducts of trimethylolpropane, 1,1,1-tris[(meth)acryloyloxyethoxyethoxy]propane, and tris(hydroxyethyl)isocyanurate tri(meth)acrylate.

[0087] On the other hand, (meth)acrylic oligomers include urethane (meth)acrylic oligomers, polyester (meth)acrylic oligomers, and epoxy (meth)acrylic oligomers.

[0088] The urethane (meth)acrylic oligomer is a compound having a urethane bond (-NHCOO-) and at least two (meth)acryloyl groups in the molecule. Specifically, it may be a urethane reaction product of a hydroxyl group-containing (meth)acrylic monomer having at least one (meth)acryloyl group and at least one hydroxyl group in the molecule with a polyisocyanate, or a urethane reaction product of a terminal isocyanato group-containing urethane compound obtained by reacting a polyol with a polyisocyanate with a (meth)acrylic monomer having at least one (meth)acryloyl group and at least one hydroxyl group in the molecule.

[0089] The hydroxyl group-containing (meth)acrylic monomer used in the urethanization reaction can be, for example, a hydroxyl group-containing (meth)acrylate monomer, specific examples of which include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate. Specific examples other than the hydroxyl group-containing (meth)acrylate monomer include N-hydroxyalkyl (meth)acrylamide monomers such as N-hydroxyethyl (meth)acrylamide and N-methylol (meth)acrylamide.

[0090] Examples of polyisocyanates that can be subjected to the urethanization reaction with the hydroxyl group-containing (meth)acrylic monomer include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diisocyanates obtained by hydrogenating aromatic isocyanates among these diisocyanates (e.g., hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, etc.), di- or tri-isocyanates such as triphenylmethane triisocyanate and dibenzylbenzene triisocyanate, and polyisocyanates obtained by polymerizing the above diisocyanates.

[0091] Furthermore, the polyol used to produce a urethane compound containing a terminal isocyanato group by reaction with a polyisocyanate may be an aromatic, aliphatic, or alicyclic polyol, as well as a polyester polyol, a polyether polyol, etc. Examples of aliphatic and alicyclic polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutanoic acid, glycerin, and hydrogenated bisphenol A.

[0092] The polyester polyol is obtained by a dehydration condensation reaction between the above-mentioned polyol and a polybasic carboxylic acid or an anhydride thereof. Examples of the polybasic carboxylic acid or anhydride thereof, when expressed by adding "(anhydride)" to the anhydride, include succinic acid (anhydride), adipic acid, maleic acid (anhydride), itaconic acid (anhydride), trimellitic acid (anhydride), pyromellitic acid (anhydride), phthalic acid (anhydride), isophthalic acid, terephthalic acid, and hexahydrophthalic acid (anhydride).

[0093] The polyether polyol may be a polyalkylene glycol, or a polyoxyalkylene-modified polyol obtained by reacting the above-mentioned polyol or dihydroxybenzene with an alkylene oxide.

[0094] A polyester (meth)acrylic oligomer is a compound having an ester bond and at least two (meth)acryloyl groups (typically (meth)acryloyloxy groups) in the molecule. Specifically, it can be obtained by a dehydration condensation reaction using (meth)acrylic acid, a polybasic carboxylic acid or its anhydride, and a polyol. Examples of polybasic carboxylic acids or their anhydrides used in the dehydration condensation reaction, expressed by adding "(anhydride)" to possible anhydrides, include succinic acid (anhydride), adipic acid, maleic acid (anhydride), itaconic acid (anhydride), trimellitic acid (anhydride), pyromellitic acid (anhydride), hexahydrophthalic acid (anhydride), phthalic acid (anhydride), isophthalic acid, and terephthalic acid. Examples of polyols used in the dehydration condensation reaction include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutanoic acid, glycerin, and hydrogenated bisphenol A.

[0095] Epoxy (meth)acrylic oligomers can be obtained, for example, by an addition reaction between polyglycidyl ether and (meth)acrylic acid, and have at least two (meth)acryloyloxy groups in the molecule. Examples of polyglycidyl ethers used in the addition reaction include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and bisphenol A diglycidyl ether.

[0096] Specific examples of the photoradical polymerization initiator include acetophenone-based initiators such as acetophenone, 3-methylacetophenone, benzil dimethyl ketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl-2-morpholinopropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzophenone-based initiators such as benzophenone, 4-chlorobenzophenone, 4,4'-diaminobenzophenone; benzoin ether-based initiators such as benzoin propyl ether, benzoin ethyl ether; thioxanthone-based initiators such as 4-isopropylthioxanthone; and others, including xanthone, fluorenone, camphorquinone, benzaldehyde, and anthraquinone.

[0097] The amount of the photoradical polymerization initiator is usually 0.5 to 20 parts by mass, and preferably 1 to 6 parts by mass, per 100 parts by mass of the radical polymerizable compound. By adding 0.5 parts by mass or more of the photoradical polymerization initiator, the radical polymerizable compound can be sufficiently cured, and the resulting polarizing plate can be endowed with high mechanical strength and adhesive strength. On the other hand, if the amount is too large, the durability of the polarizing plate may be reduced.

[0098] However, since radical polymerization tends to result in large cure shrinkage, it is preferable that the active energy ray-curable adhesive composition contain only a cationically polymerizable curable component as the curable component (A).

[0099] (Photocationic polymerization initiator (B)) The active energy ray-curable adhesive composition contains a photocationic polymerization initiator (B). This allows the curable component (A) to be cured by cationic polymerization upon irradiation with active energy rays to form an adhesive layer. The photocationic polymerization initiator (B) generates cationic species or Lewis acids upon irradiation with active energy rays such as visible light, ultraviolet light, X-rays, or electron beams, thereby initiating the polymerization reaction of the curable component (A). Because the photocationic polymerization initiator (B) acts catalytically upon exposure to light, it exhibits excellent storage stability and workability even when mixed with the curable component (A). Examples of compounds that can be used as the photocationic polymerization initiator (B) and generate cationic species or Lewis acids upon irradiation with active energy rays include aromatic diazonium salts; onium salts such as aromatic iodonium salts and aromatic sulfonium salts; and iron-arene complexes.

[0100] Examples of aromatic diazonium salts include benzenediazonium hexafluoroantimonate, benzenediazonium hexafluorophosphate, and benzenediazonium hexafluoroborate.

[0101] Examples of aromatic iodonium salts include diphenyliodonium tetrakis(pentafluorophenyl)borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, and di(4-nonylphenyl)iodonium hexafluorophosphate.

[0102] Examples of aromatic sulfonium salts include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, 4,4'-bis[diphenylsulfonio]diphenyl sulfide bishexafluorophosphate, 4,4'-bis[di(β-hydroxyethoxy)phenylsulfonio]diphenyl sulfide bishexafluoroantimonate, 4,4'-bis[di(β-hydroxyethoxy)phenylsulfonio]diphenyl sulfide bishexafluorophosphate, 7-[di(p-toluyl)sulfonio]-2-isopropylthioxanthone hexafluoroantimonate, 7-[di(p-toluyl)sulfonio]-2-isopropylthioxanthone tetrakis(pentafluorophenyl)borate, and 4-phenylcarbonyl-4'-diphenylsulfonio-diphenyl sulfide. hexafluorophosphate, 4-(p-tert-butylphenylcarbonyl)-4'-diphenylsulfonio-diphenylsulfide hexafluoroantimonate, 4-(p-tert-butylphenylcarbonyl)-4'-di(p-toluyl)sulfonio-diphenylsulfide tetrakis(pentafluorophenyl)borate.

[0103] Examples of iron-arene complexes include xylene-cyclopentadienyliron(II) hexafluoroantimonate, cumene-cyclopentadienyliron(II) hexafluorophosphate, and xylene-cyclopentadienyliron(II) tris(trifluoromethylsulfonyl)methanide.

[0104] The photocationic polymerization initiator (B) may be used alone or in combination of two or more. Among the above, aromatic sulfonium salts are particularly preferred because they have ultraviolet absorption properties even in the wavelength region around 300 nm, and therefore are excellent in curability, and can provide a cured adhesive layer having good mechanical strength and adhesive strength.

[0105] The content of the cationic photopolymerization initiator (B) is 0.5 to 10 parts by mass, preferably 1 to 4 parts by mass, per 100 parts by mass of the total amount of the curable components (A). By incorporating 1 part by mass or more of the cationic photopolymerization initiator (B), the curable components can be sufficiently cured, resulting in a cured adhesive layer with sufficient adhesive strength and hardness. On the other hand, if the amount is too large, the amount of ionic substances in the cured product increases, which can increase the hygroscopicity of the cured product and potentially reduce the durability of the laminate. Therefore, the amount of the cationic photopolymerization initiator (B) is set to 10 parts by mass or less per 100 parts by mass of the total amount of the curable components (A).

[0106] When a radically polymerizable curable component is contained as the curable component, it is preferable to contain a radical polymerization initiator in addition to the photocationic polymerization initiator (B) as the polymerization initiator.

[0107] (Photosensitizer (C)) The active energy ray-curable adhesive composition may contain a photosensitizer (C). By containing the photosensitizer (C) in the first active energy ray-curable composition, the curability of the adhesive can be improved compared to when the photosensitizer (C) is not contained.

[0108] The photosensitizer (C) is represented by the following general formula (I): [ka] (In the formula, R 1 and R 2 each independently represents an alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 12 carbon atoms, and R 3 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) The photocationic polymerization initiator (B) exhibits an absorption maximum in the wavelength region around 300 nm or shorter, and generates cationic species or Lewis acids in response to light of a wavelength around that range, thereby initiating cationic polymerization of the cationically polymerizable curable component. However, the photosensitizer (C) is preferably one that exhibits an absorption maximum in the wavelength region longer than 380 nm so as to be sensitive to light of longer wavelengths. An anthracene compound is preferably used as the photosensitizer (C).

[0109] Specific examples of the anthracene-based compound include: 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-diisopropoxyanthracene, 9,10-dibutoxyanthracene, 9,10-dipentyloxyanthracene, 9,10-dihexyloxyanthracene, 9,10-bis(2-methoxyethoxy)anthracene, 9,10-bis(2-ethoxyethoxy)anthracene, 9,10-bis(2-butoxyethoxy)anthracene, 9,10-bis(3-butoxypropoxy)anthracene, 2-methyl or 2-ethyl-9,10-dimethoxyanthracene, 2-methyl or 2-ethyl-9,10-diethoxyanthracene, 2-methyl or 2-ethyl-9,10-dipropoxyanthracene, 2-methyl or 2-ethyl-9,10-diisopropoxyanthracene, 2-methyl or 2-ethyl-9,10-dibutoxyanthracene, 2-methyl or 2-ethyl-9,10-dipentyloxyanthracene, 2-methyl or 2-ethyl-9,10-dihexyloxyanthracene Examples include:

[0110] By including a photosensitizer (C) in an active energy ray-curable adhesive composition, the curability of the adhesive can be improved compared to an adhesive that does not include the photosensitizer. This effect can be achieved by setting the content of the photosensitizer to 0.1 parts by mass or more per 100 parts by mass of the total amount of the curable components (A). On the other hand, if the content of the photosensitizer (C) is too high, problems such as precipitation during low-temperature storage can occur, so the content is preferably set to 2 parts by mass or less per 100 parts by mass of the total amount of the curable components (A).

[0111] (Photosensitizing Coagent (D)) The active energy ray-curable adhesive composition may contain a photosensitizer (D), which is preferably a naphthalene-based photosensitizer.

[0112] Specific examples of the naphthalene-based photosensitizing aid include: 4-methoxy-1-naphthol, 4-ethoxy-1-naphthol, 4-propoxy-1-naphthol, 4-butoxy-1-naphthol, 4-hexyloxy-1-naphthol, 1,4-dimethoxynaphthalene, 1-ethoxy-4-methoxynaphthalene, 1,4-diethoxynaphthalene, 1,4-dipropoxynaphthalene, 1,4-Dibutoxynaphthalene Examples include:

[0113] By including a naphthalene-based photosensitizing aid in an active energy ray-curable adhesive composition, the curability of the adhesive can be improved compared to an adhesive that does not include the aid. This effect can be achieved by setting the content of the naphthalene-based photosensitizing aid to 0.1 parts by mass or more per 100 parts by mass of the total amount of curable component (A). On the other hand, since a high content of the naphthalene-based photosensitizing aid can cause problems such as precipitation during low-temperature storage, the content is preferably set to 5 parts by mass or less per 100 parts by mass of the total amount of curable component (A). The content of the naphthalene-based photosensitizing aid is preferably 3 parts by mass or less per 100 parts by mass of the total amount of curable component (A).

[0114] (Additive component (E)) The active energy ray-curable adhesive composition may contain an optional additive component (E) as long as the effect of the present invention is not impaired. Examples of the additive component (E) include an ion trapping agent, an antioxidant, a light stabilizer, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow modifier, a plasticizer, an antifoaming agent, a leveling agent, a dye, and an organic solvent.

[0115] When the additive component (E) is contained, the content thereof is preferably 10 parts by mass or less per 100 parts by mass of the total amount of the curable component (A).

[0116] The above-mentioned cationic photopolymerization initiator (B), photosensitizer (C), photosensitization aid (D), and additive component (E) may be added in a solvent-free state during preparation of the active energy ray-curable adhesive composition, or may be added directly after dilution with a solvent. The above-mentioned ranges of the contents are all based on the solid content.

[0117] In one embodiment of the present invention, the active energy ray-curable composition that forms the first cured product layer is preferably a composition containing an epoxy compound (A2-1) that contains a tricyclic fused ring and two glycidyl ether groups in the molecule. When the active energy ray-curable composition contains an epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule, it preferably further contains an oxetane compound (A5), more preferably contains a polyfunctional oxetane compound (A5-1), and even more preferably contains a bifunctional oxetane compound. When the active energy ray-curable composition contains an epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule and an oxetane compound (A5), it is preferable that the composition further contains at least one selected from an alicyclic epoxy compound (A1) and a polyfunctional aliphatic epoxy compound (A2) (excluding the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule).

[0118] When the active energy ray-curable composition contains an epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule and an oxetane compound (A5), the content of the oxetane compound (A5) is greater than the content of the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule. When the active energy ray-curable composition contains an epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule and a polyfunctional oxetane compound (A5-1), the content of the polyfunctional oxetane compound (A5-1) is preferably greater than the content of the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule. The content ratio (mass ratio) of the polyfunctional oxetane compound (A5-1) to the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule, polyfunctional oxetane compound (A5-1) / epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule, is preferably 1.1 / 1 to 5 / 1, more preferably 1.5 / 1 to 5 / 1, and even more preferably 2 / 1 to 5 / 1. Within the above range, a cured film with a high crosslink density can be easily obtained, thereby suppressing the amount of iodine migration. When the active energy ray-curable composition contains an epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule, and an oxetane compound (A5), the content of the oxetane compound (A5) is preferably 35 mass% or more, preferably 80 mass% or less, more preferably 75 mass% or less, and even more preferably 70 mass% or less, based on the total mass of the curable component (A). When the active energy ray-curable composition contains an epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule and an oxetane compound (A5), the content of the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule is preferably 1 mass% or more, more preferably 5 mass% or more, and is preferably less than 35 mass%, and more preferably 30 mass% or less, based on the total mass of the curable component (A).

[0119] (viscosity) The viscosity of the active energy ray-curable adhesive composition may be any viscosity that allows it to be applied by various methods, but its viscosity at 25°C may be, for example, 200 mPa·s or less, preferably 0.1 mPa·s or more and 180 mPa·s or less. If the viscosity is too low, it tends to be difficult to form a layer with the desired thickness. On the other hand, if the viscosity is too high, it tends to be difficult to flow, making it difficult to obtain a uniform coating film without unevenness. The viscosity referred to here is the value measured at 10 rpm using an E-type viscometer after adjusting the adhesive to 25°C.

[0120] (Curing method) The active energy ray-curable adhesive composition can be used in the form of an electron beam curable or ultraviolet ray curable type. In this specification, active energy rays are defined as energy rays that can decompose a compound that generates active species to generate active species. Examples of such active energy rays include visible light, ultraviolet rays, infrared rays, X-rays, α rays, β rays, γ rays, and electron beams.

[0121] In the case of electron beam curing, any suitable electron beam irradiation conditions can be adopted as long as they are conditions that can cure the active energy beam-curable adhesive composition. For example, the acceleration voltage for electron beam irradiation is preferably 5 kV or more and 300 kV or less, more preferably 10 kV or more and 250 kV or less. If the acceleration voltage is less than 5 kV, the electron beam may not reach the adhesive, resulting in insufficient curing. If the acceleration voltage is more than 300 kV, the electron beam may have too strong a penetration force through the sample, causing it to bounce back and damaging the transparent protective film or polarizer. The exposure dose is 5 kGy or more and 100 kGy or less, more preferably 10 kGy or more and 75 kGy or less. If the exposure dose is less than 5 kGy, the adhesive will not be cured sufficiently. If the exposure dose is more than 100 kGy, the optical layer will be damaged, resulting in reduced mechanical strength and yellowing, and the desired optical properties will not be obtained.

[0122] Electron beam irradiation is usually carried out in an inert gas atmosphere, but if necessary, it can be carried out in the atmosphere or with a small amount of oxygen introduced. By introducing oxygen appropriately, oxygen inhibition is intentionally caused in the optical layer that is first exposed to the electron beam, preventing damage to other optical layers and allowing the electron beam to be efficiently irradiated only on the adhesive.

[0123] In the case of the ultraviolet curing type, the light irradiation intensity of the active energy ray curing adhesive composition is determined depending on the composition of the adhesive and is not particularly limited, but is preferably 10 mW / cm 2 More than 1,000mW / cm 2 The light irradiation intensity of the resin composition is preferably 10 mW / cm or less. 2 If it is less than 1,000mW / cm, the reaction time will be too long and 2If the irradiation intensity exceeds this range, the heat radiated from the light source and the heat generated during polymerization of the composition may cause yellowing of the adhesive's constituent materials. The irradiation intensity is preferably an intensity in a wavelength range effective for activating the cationic photopolymerization initiator (B), more preferably an intensity in a wavelength range of 400 nm or less, and even more preferably an intensity in a wavelength range of 280 nm or more and 320 nm or less. Irradiation is performed once or multiple times at such a light irradiation intensity, and the cumulative light amount is preferably 10 mJ / cm. 2 More preferably, 100 mJ / cm 2 More than 1,000mJ / cm 2 The integrated light intensity on the adhesive is set to 10 mJ / cm 2 If the cumulative light intensity is less than 1,000 mJ / cm, the generation of active species derived from the polymerization initiator will be insufficient, resulting in insufficient curing of the adhesive. 2 If the irradiation time exceeds this value, the irradiation time becomes long, which is disadvantageous for improving productivity. In this case, the wavelength region (UVA (320 nm or more and 390 nm or less) or UVB (280 nm or more and 320 nm or less), etc.) and its integrated light amount can be appropriately set depending on the combination of the types of the first retardation layer 30 and the second retardation layer 40 and the adhesive type.

[0124] The light source used to polymerize and cure the active energy ray-curable adhesive composition of the present invention by irradiation with active energy rays is not particularly limited, and examples 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 nm to 440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps. From the viewpoints of energy stability and ease of use of the device, ultraviolet light sources having an emission distribution at wavelengths of 400 nm or less are preferred.

[0125] (Storage modulus of the first cured material layer) From the viewpoint of inhibiting corrosion of the conductive layer, the storage modulus (E1) of the first cured material layer at a temperature of 80°C is preferably 300 MPa or more, more preferably 500 MPa or more, and even more preferably 1000 MPa or more. Also, it is preferably 5000 MPa or less, more preferably 4000 MPa or less, and even more preferably 3500 MPa or less. The storage modulus (E1) of the first cured material layer is measured by the method described in the Examples section below.

[0126] From the viewpoint of inhibiting corrosion and inhibiting cracking during durability testing, the storage modulus (E1) of the first cured material layer at a temperature of 80°C and the storage modulus (E2) of the second cured material layer at a temperature of 80°C described below preferably satisfy the relationship E1>E2, and, assuming E1-E2=ΔE, ΔE is more preferably 2000 MPa or less, and even more preferably 1500 MPa or less.

[0127] It is preferable that the difference between the storage modulus of the first cured material layer at a temperature of 30° C. and that at a temperature of 80° C. is not too large. If the difference between the storage modulus at a temperature of 30° C. and that at a temperature of 80° C. is too large, metal corrosion tends to occur more easily. The difference between the storage modulus at a temperature of 30° C. and that at a temperature of 80° C. is preferably 1500 MPa or less.

[0128] (Glass transition temperature of the first cured material layer) From the viewpoint of inhibiting corrosion of the conductive layer, the glass transition temperature (Tg1) of the first cured material layer is preferably 65° C. or higher, more preferably 70° C. or higher, and even more preferably 75° C. or higher. Also, it is preferably 200° C. or lower, more preferably 150° C. or lower, and even more preferably 120° C. or lower. The glass transition temperature (Tg1) of the first cured material layer is measured by the method described in the Examples section below.

[0129] (Moisture permeability of the first cured material layer) The moisture permeability of the first cured material layer at a temperature of 80°C is preferably low from the viewpoint of inhibiting metal corrosion. The first cured material layer having a thickness of 30 µm preferably has a moisture permeability of 1500 g / (m) as measured by the cup method specified in JIS Z 0208 under conditions of a temperature of 80°C and a relative humidity of 90%. 2 24hr) or less, more preferably 1000g / (m 2 24hr) or less, more preferably 950g / (m 2 The moisture permeability is usually 100 g / (m 2 24 hours or more.

[0130] Specifically, the moisture permeability J of the first cured film can be calculated by preparing a laminate (for example, a laminate of a 20 μm triacetyl cellulose film / a 5 μm pressure-sensitive adhesive layer / a 30 μm-thick first cured layer) in which the first cured layer is formed on a substrate film or the like having a known moisture permeability, measuring the moisture permeability of the laminate using the method described above, and then using the measurement results to determine the moisture permeability J based on the following formula. 1 / Jt=(1 / J)+(1 / Jsub) In the above formula, Jt is the moisture permeability of the laminate, and Jsub is the moisture permeability of the laminate in a layer structure excluding the first cured product layer. When measuring the moisture permeability of the laminate according to JIS Z 0208, the laminate is attached to a cup with the cured film facing outward. For example, a laminate having a layer structure of a 20 μm triacetyl cellulose film / a 5 μm pressure-sensitive adhesive layer / a 30 μm thick first cured material layer preferably has a moisture permeability of 1000 g / (m) measured under conditions of a temperature of 80° C. and a relative humidity of 90% by the cup method specified in JIS Z 0208. 2 24hr) or less, and more preferably 950g / (m 2 The moisture permeability is usually 100 g / (m 2 24 hours or more.

[0131] (phase contrast layer) The optical laminate of the present invention includes a retardation layer 20 having at least one retardation-exhibiting layer that is a polymer of a polymerizable liquid crystal compound. The retardation layer 20 is not particularly limited as long as it includes at least one retardation-exhibiting layer that imparts a predetermined retardation to light, and may be, for example, an optical compensation layer such as a half-wave layer, a quarter-wave layer, or a positive C plate. The retardation layer may be a retardation layer with a normal wavelength dispersion or a reverse wavelength dispersion. As long as the retardation layer 20 includes at least one retardation-exhibiting layer, it may consist solely of the retardation-exhibiting layer or may include other layers in addition to the retardation-exhibiting layer. Examples of other layers include a substrate layer, an alignment layer, and a protective layer. Note that the other layers do not affect the retardation value. The retardation layer 20 may also be composed of two layers: a first retardation layer 30 and a second retardation layer 40. Hereinafter, the laminate in which the first retardation layer 30 and the second retardation layer 40 are bonded via the second cured product layer 50 described later will also be referred to as a retardation layer laminate 60.

[0132] Examples of the retardation layer include a layer containing a polymer of a polymerizable liquid crystal compound (hereinafter also referred to as a liquid crystal layer), or a stretched film. At least one of the first retardation layer 30 and the second retardation layer 40 is preferably a liquid crystal layer. When the first retardation layer 30 is a liquid crystal layer, the surface of the first retardation layer 30 facing the second cured material layer 50 is preferably a liquid crystal layer serving as a retardation layer. When the second retardation layer 40 is a liquid crystal layer, the surface of the second retardation layer 40 facing the second cured material layer 50 is preferably a liquid crystal layer serving as a retardation layer. A retardation layer that is a liquid crystal layer is generally easier to make thinner than a retardation layer that is a stretched film.

[0133] From the viewpoint of adhesion, at least one of the first retardation layer 30 and the second retardation layer 40 has a light transmittance at a wavelength of 320 nm of preferably 5% or more, more preferably 10% or more, and even more preferably 30% or more. The light transmittance can be measured according to the measurement method described in the Examples section below.

[0134] At least one of the first retardation layer 30 and the second retardation layer 40 preferably has a light transmittance of 0% or more and 10% or less at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm, more preferably has a light transmittance of 0% or more and 5% or less at a wavelength of 380 nm and a light transmittance of 35% or more at a wavelength of 400 nm, and even more preferably has a light transmittance of 0% or more and 1% or less at a wavelength of 380 nm and a light transmittance of 40% or more at a wavelength of 400 nm.

[0135] When the first retardation layer 30 and the second retardation layer 40 each consist of only a retardation-exhibiting layer, the thickness of each is preferably 0.5 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less. When the first retardation layer 30 and the second retardation layer 40 each include layers other than the retardation-exhibiting layer (such as a substrate layer, an alignment film layer, or a protective layer), the total thickness is preferably 0.5 μm or more and 300 μm or less, and more preferably 0.5 μm or more and 150 μm or less.

[0136] Examples of combinations of the first retardation layer 30 and the second retardation layer 40 include: i) a combination of a half-wave layer and a quarter-wave layer; ii) a combination of a half-wave layer and an optical compensation layer; iii) a combination of a quarter-wave layer and an optical compensation layer; etc.

[0137] In the case of i), it is preferable that the first retardation layer 30 is a half wavelength layer and the second retardation layer 40 is a quarter wavelength layer.

[0138] In the case of ii), it is preferable that the first retardation layer 30 is a half-wave layer and the second retardation layer 40 is an optical compensation layer, and it is more preferable that the first retardation layer 30 is a half-wave layer and the second retardation layer 40 is a positive C plate.

[0139] In the case of iii), it is preferable that the first retardation layer 30 is a quarter-wave layer and the second retardation layer 40 is an optical compensation layer, and it is more preferable that the first retardation layer 30 is a quarter-wave layer and the second retardation layer 40 is a positive C plate.

[0140] The half-wave layer imparts a phase difference of π (=λ / 2) to the electric field oscillation direction (polarization plane) of incident light, and has the function of changing the direction (polarization orientation) of linearly polarized light. In addition, when circularly polarized light is incident, the direction of rotation of the circularly polarized light can be reversed.

[0141] A half-wave layer is a layer in which the in-plane retardation value Re(λ) at a specific wavelength λ nm satisfies Re(λ)=λ / 2. While it is sufficient for Re(λ)=λ / 2 to be achieved at any wavelength in the visible light range, it is preferable for it to be achieved at a wavelength of 550 nm. The in-plane retardation value Re(550) at a wavelength of 550 nm preferably satisfies 210 nm≦Re(550)≦300 nm. It is more preferable for it to satisfy 220 nm≦Re(550)≦290 nm.

[0142] The quarter-wave layer imparts a phase difference of π / 2 (=λ / 4) to the electric field oscillation direction (polarization plane) of incident light, and has the function of converting linearly polarized light of a specific wavelength into circularly polarized light (or circularly polarized light into linearly polarized light).

[0143] The quarter-wave layer is a layer in which the in-plane retardation value Re(λ) at a specific wavelength λ nm satisfies Re(λ)=λ / 4. This may be achieved at any wavelength in the visible light range, but is preferably achieved at a wavelength of 550 nm. The in-plane retardation value Re(550) at a wavelength of 550 nm preferably satisfies 100 nm≦Re(550)≦160 nm. It is more preferable that the in-plane retardation value Re(550) at a wavelength of 550 nm satisfies 110 nm≦Re(550)≦150 nm.

[0144] Examples of optical compensation layers include a positive A plate and a positive C plate. A positive A plate satisfies the relationship Nx>Ny, where Nx is the refractive index in the slow axis direction in the plane, Ny is the refractive index in the fast axis direction in the plane, and Nz is the refractive index in the thickness direction. The positive A plate preferably satisfies the relationship Nx>Ny≧Nz. The positive A plate can also function as a quarter-wave layer. The positive C plate satisfies the relationship Nz>Nx≧Ny.

[0145] The reverse wavelength dispersion is an optical property in which the in-plane retardation value at a short wavelength is smaller than the in-plane retardation value at a long wavelength, and is preferably expressed by the following formula (2): Re(450)≦Re(550)≦Re(650) (2) Here, Re(λ) represents the in-plane retardation value for light with a wavelength of λ nm.

[0146] The optical properties of the retardation layer can be adjusted by the orientation state of the liquid crystal compound constituting the retardation-exhibiting layer or the stretching method of the stretched film constituting the retardation-exhibiting layer. By appropriately adjusting the optical properties of the retardation layer, a polarizing plate composite having antireflection properties can be obtained by laminating the retardation layer laminate and a linear polarizing plate.

[0147] (Retardation layer formed from a liquid crystal layer) The case where the retardation layer is a liquid crystal layer will be described. FIG. 2 is a schematic cross-sectional view showing an example of a retardation layer including a liquid crystal layer and other layers. The first retardation layer 30 shown in FIG. 2 is formed by laminating a base layer 31, an alignment layer 32, and a liquid crystal layer 33 in this order. The retardation layer is not limited to the first retardation layer 30 shown in FIG. 2 as long as it includes the liquid crystal layer 33. The retardation layer may be formed by peeling the base layer 31 from the first retardation layer 30 and only comprising the alignment layer 32 and the retardation layer 33, or by peeling the base layer 31 and the alignment layer 32 from the first retardation layer 30 and only comprising the liquid crystal layer 33. From the viewpoint of thinning, the retardation layer is preferably formed by peeling the base layer 31, and more preferably by only comprising the liquid crystal layer 33. The base layer 31 functions as a support layer that supports the alignment layer 32 and the liquid crystal layer 33, which are formed on the base layer 31. The base layer 31 is preferably a film made of a resin material.

[0148] Examples of resin materials that can be used include those with excellent transparency, mechanical strength, thermal stability, and stretchability. Specific examples include polyolefin resins such as polyethylene and polypropylene; cyclic polyolefin resins such as norbornene-based polymers; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; (meth)acrylic acid resins such as polymethyl(meth)acrylate; cellulose ester resins such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; vinyl alcohol resins such as polyvinyl alcohol and polyvinyl acetate; polycarbonate resins; polystyrene resins; polyarylate resins; polysulfone resins; polyethersulfone resins; polyamide resins; polyimide resins; polyetherketone resins; polyphenylene sulfide resins; polyphenylene oxide resins; and mixtures and copolymers thereof. Among these resins, it is preferable to use any one of cyclic polyolefin resins, polyester resins, cellulose ester resins, and (meth)acrylic acid resins, or mixtures thereof. The above "(meth)acrylic acid" means "at least one of acrylic acid and methacrylic acid."

[0149] The base layer 31 may be a single layer made of one or a mixture of two or more of the above resins, or may have a multi-layer structure of two or more layers. When it has a multi-layer structure, the resins constituting each layer may be the same or different.

[0150] The resin material forming the resin film may contain any additives, such as ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, coloring inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and colorants.

[0151] The thickness of the base layer 31 is not particularly limited, but in general, from the standpoint of workability such as strength and handling, it is preferably 5 μm or more and 200 μm or less, more preferably 10 μm or more and 200 μm or less, and even more preferably 10 μm or more and 150 μm or less.

[0152] In order to improve the adhesion between the substrate layer 31 and the alignment layer 32, corona treatment, plasma treatment, flame treatment, or the like may be performed on at least the surface of the substrate layer 31 on which the alignment layer 32 is formed, or a primer layer or the like may be formed. When the substrate layer 31, or the substrate layer 31 and the alignment layer 32, are peeled off to form a retardation layer, the peeling can be facilitated by adjusting the adhesion at the peeling interface.

[0153] The alignment layer 32 has an alignment regulating force that aligns the liquid crystal compound contained in the retardation-exhibiting layer 33 of the liquid crystal layer formed on the alignment layer 32 in a desired direction. Examples of the alignment layer 32 include an alignment polymer layer formed from an alignment polymer, a photo-aligned polymer layer formed from a photo-aligned polymer, and a groove alignment layer having a concavo-convex pattern or multiple grooves on the layer surface. The thickness of the alignment layer 32 is usually 0.01 μm or more and 10 μm or less, and preferably 0.01 μm or more and 5 μm or less.

[0154] The oriented polymer layer can be formed by applying a composition in which an oriented polymer is dissolved in a solvent to the base layer 31, removing the solvent, and optionally performing a rubbing treatment. In this case, the alignment control force of the oriented polymer layer formed from the oriented polymer can be adjusted as desired by changing the surface condition of the oriented polymer and the rubbing conditions.

[0155] The photo-aligned polymer layer can be formed by applying a composition containing a polymer or monomer having a photoreactive group and a solvent to the base layer 31 and irradiating the composition with polarized light. In this case, the alignment control force of the photo-aligned polymer layer can be adjusted as desired by, for example, irradiating the photo-aligned polymer with polarized light.

[0156] The groove alignment layer can be formed by, for example, a method of forming a concave-convex pattern by exposing the surface of a photosensitive polyimide film through an exposure mask having slits in the shape of a pattern, developing, etc., or a method of forming an uncured layer of active energy ray-curable resin on a plate-shaped master having grooves on its surface, transferring this layer to the base layer 31, and curing the layer; or a method of forming an uncured layer of active energy ray-curable resin on the base layer 31, and pressing a roll-shaped master having concave-convex shapes against this layer to form concave-convex shapes and then curing the layer.

[0157] The retardation-exhibiting layer 33, which is a liquid crystal layer, is not particularly limited as long as it imparts a predetermined retardation to light, and examples thereof include a retardation-exhibiting layer that functions as a retardation-exhibiting layer for a half-wave layer, a retardation-exhibiting layer for a quarter-wave layer, a retardation-exhibiting layer for an optical compensation layer such as a positive C plate, and a retardation-exhibiting layer for a reverse wavelength dispersion quarter-wave layer.

[0158] The retardation layer 33, which is a liquid crystal layer, can be formed using a known liquid crystal compound. The type of liquid crystal compound is not particularly limited, and a rod-shaped liquid crystal compound, a discotic liquid crystal compound, or a mixture thereof can be used. In addition, the liquid crystal compound may be a polymer liquid crystal compound, a polymerizable liquid crystal compound, or a mixture thereof. Examples of the liquid crystal compound include those described in JP-T-11-513019, JP-A-2005-289980, JP-A-2007-108732, JP-A-2010-244038, JP-A-2010-31223, JP-A-2010-270108, JP-A-2011-6360, JP-A-2011-207765, JP-A-2016-81035, WO 2017 / 043438, and JP-T-2011-207765.

[0159] For example, when a polymerizable liquid crystal compound is used, a composition containing the polymerizable liquid crystal compound is applied onto the alignment layer 32 to form a coating film, and the coating film is cured to form the retardation-exhibiting layer 33. The thickness of the retardation-exhibiting layer 33 is preferably 0.5 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less. The composition containing a polymerizable liquid crystal compound may contain, in addition to the liquid crystal compound, a polymerization initiator, a polymerizable monomer, a surfactant, a solvent, an adhesion improver, a plasticizer, an alignment agent, etc. Examples of methods for applying the composition containing a polymerizable liquid crystal compound include known methods such as die coating. Examples of methods for curing the composition containing a polymerizable liquid crystal compound include known methods such as irradiation with active energy rays (e.g., ultraviolet rays).

[0160] (Retardation Layer Having Stretched Film as Retardation Layer) The case where the retardation-exhibiting layer is a stretched film will be described below. A stretched film is usually obtained by stretching a substrate. For example, a method of stretching the substrate involves preparing a roll (winder) on which the substrate is wound, continuously unwinding the substrate from the winder, and transporting the unwound substrate to a heating furnace. The temperature of the heating furnace is set in the range of approximately the glass transition temperature of the substrate (°C) to [glass transition temperature + 100] (°C), preferably approximately the glass transition temperature (°C) to [glass transition temperature + 50] (°C). In the heating furnace, when stretching the substrate in the direction of travel or in a direction perpendicular to the direction of travel, the transport direction and tension are adjusted to tilt the substrate at any angle, and uniaxial or biaxial thermal stretching is performed. The stretching ratio is usually 1.1 to 6 times, preferably 1.1 to 3.5 times.

[0161] The method of oblique stretching is not particularly limited as long as it can continuously tilt the orientation axis at a desired angle, and any known stretching method can be used. Examples of such stretching methods include those described in JP-A-50-83482 and JP-A-2-113920. When retardation is imparted to a film by stretching, the thickness after stretching is determined by the thickness before stretching and the stretch ratio.

[0162] The substrate is usually a transparent substrate. A transparent substrate refers to a substrate that is transparent enough to transmit light, particularly visible light. Transparency refers to a property in which the transmittance for light rays with wavelengths of 380 nm to 780 nm is 80% or higher. Specific examples of transparent substrates include translucent resin substrates. Resins constituting translucent resin substrates include polyolefins such as polyethylene and polypropylene; cyclic olefin resins such as norbornene-based polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid esters; polyacrylic acid esters; cellulose esters such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; polyphenylene sulfide, and polyphenylene oxide. From the viewpoints of availability and transparency, polyethylene terephthalate, polymethacrylic acid esters, cellulose esters, cyclic olefin resins, and polycarbonates are preferred.

[0163] Cellulose esters are cellulose in which some or all of the hydroxyl groups contained in cellulose have been esterified, and are readily available on the market. Cellulose ester substrates are also readily available on the market. Examples of commercially available cellulose ester substrates include "Fujitac (registered trademark) Film" (Fujifilm Corporation); "KC8UX2M," "KC8UY," and "KC4UY" (Konica Minolta Opto, Inc.).

[0164] Polymethacrylic acid esters and polyacrylic acid esters (hereinafter, polymethacrylic acid esters and polyacrylic acid esters may be collectively referred to as (meth)acrylic resins)

[0165] Examples of (meth)acrylic resins include homopolymers of alkyl methacrylates or alkyl acrylates, and copolymers of alkyl methacrylates and alkyl acrylates. Specific examples of alkyl methacrylates include methyl methacrylate, ethyl methacrylate, and propyl methacrylate, and specific examples of alkyl acrylates include methyl acrylate, ethyl acrylate, and propyl acrylate. Commercially available general-purpose (meth)acrylic resins can be used as such (meth)acrylic resins. Impact-resistant (meth)acrylic resins may also be used as (meth)acrylic resins.

[0166] To further improve mechanical strength, it is also preferable to incorporate rubber particles into the (meth)acrylic resin. The rubber particles are preferably acrylic. Here, the acrylic rubber particles are particles having rubber elasticity obtained by polymerizing an acrylic monomer mainly composed of an acrylic acid alkyl ester, such as butyl acrylate or 2-ethylhexyl acrylate, in the presence of a polyfunctional monomer. The acrylic rubber particles may be formed as a single layer of such rubber-elastic particles, or may be a multilayer structure having at least one rubber-elastic layer. Examples of multilayered acrylic rubber particles include those having a core of the above-described rubber-elastic particles coated with a hard methacrylic acid alkyl ester polymer, those having a core of a hard methacrylic acid alkyl ester polymer coated with the above-described rubber-elastic acrylic polymer, and those having a hard core coated with a rubber-elastic acrylic polymer, which is further coated with a hard methacrylic acid alkyl ester polymer. The rubber particles formed in the elastic layer usually have an average diameter in the range of 50 nm to 400 nm.

[0167] The content of rubber particles in the (meth)acrylic resin is usually 5 to 50 parts by mass per 100 parts by mass of the (meth)acrylic resin. (Meth)acrylic resin and acrylic rubber particles are commercially available in a mixed state, so these commercially available products can be used. Examples of commercially available (meth)acrylic resins containing acrylic rubber particles include "HT55X" and "Technoloy S001" sold by Sumitomo Chemical Co., Ltd. "Technoloy S001" is sold in the form of a film.

[0168] Cyclic olefin resins are readily available on the market. Commercially available cyclic olefin resins include "Topas" (registered trademark) [Ticona GmbH (Germany)], "Arton" (registered trademark) [JSR Corporation], "ZEONOR" (registered trademark) [Zeon Corporation], "ZEONEX" (registered trademark) [Zeon Corporation], and "Apel" (registered trademark) [Mitsui Chemicals, Inc.]. Such cyclic olefin resins can be formed into a film by known means such as solvent casting or melt extrusion to form a substrate. Commercially available cyclic olefin resin substrates can also be used. Commercially available cyclic olefin resin substrates include "S-Cina" (registered trademark) [Sekisui Chemical Co., Ltd.], "SCA40" (registered trademark) [Sekisui Chemical Co., Ltd.], "ZEONORFILM" (registered trademark) [Optes Co., Ltd.], and "Arton Film" (registered trademark) [JSR Corporation].

[0169] When the cyclic olefin resin is a copolymer of a cyclic olefin with a chain olefin or an aromatic compound having a vinyl group, the content of structural units derived from the cyclic olefin is usually 50 mol% or less, preferably 15 mol% to 50 mol%, based on the total structural units of the copolymer. Examples of chain olefins include ethylene and propylene, and examples of aromatic compounds having a vinyl group include styrene, α-methylstyrene, and alkyl-substituted styrenes. When the cyclic olefin resin is a terpolymer of a cyclic olefin, a chain olefin, and an aromatic compound having a vinyl group, the content of structural units derived from the chain olefin is usually 5 mol% to 80 mol% based on the total structural units of the copolymer, and the content of structural units derived from aromatic compounds having a vinyl group is usually 5 mol% to 80 mol% based on the total structural units of the copolymer. Such terpolymers have the advantage that the amount of expensive cyclic olefin used can be relatively reduced during their production.

[0170] (Second cured material layer) When the retardation layer is composed of a retardation laminate 60 of a first retardation layer 30 and a second retardation layer 40, the second cured material layer 50 can be disposed to adhere the first retardation layer 30 and the second retardation layer 40. The thickness of the second cured material layer 50 may be, for example, 20 μm or less, preferably 10 μm or less, and more preferably 5 μm or less. The thickness of the second cured material layer 50 may be, for example, 0.5 μm or more.

[0171] The second cured material layer 50 contains a cured product of an active energy ray-curable adhesive composition. The description of the first cured material layer 14 above applies to the active energy ray-curable adhesive composition used in the second cured material layer 50. The active energy ray-curable adhesive composition used in the second cured material layer 50 does not have to contain either a photosensitizer or a photosensitization aid. The active energy ray-curable adhesive composition contained in the second cured material layer 50 may be the same as or different from the active energy ray-curable adhesive composition contained in the first cured material layer 14. The second cured material layer 50 is preferably a cured material layer of a cationically polymerizable adhesive composition.

[0172] (Storage modulus of second cured material layer) From the viewpoint of suppressing phase difference cracks during processing, the storage modulus of the second cured material layer at a temperature of 30°C is preferably 300 MPa or more, more preferably 500 MPa or more, and even more preferably 1000 MPa or more. Also, it is preferably 5000 MPa or less, more preferably 4000 MPa or less, and even more preferably 3500 MPa or less. The storage modulus of the second cured material layer is measured by the method described in the Examples section below. From the viewpoint of inhibiting corrosion of the conductive layer, the storage modulus (E2) of the second cured material layer at a temperature of 80°C is preferably 20 MPa or more, more preferably 30 MPa or more, and even more preferably 40 MPa or more. Also, it is preferably 100 MPa or less, more preferably 90 MPa or less, and even more preferably 80 MPa or less. The storage modulus (E2) of the second cured material layer is measured by the method described in the Examples section below.

[0173] (Glass transition temperature of second cured material layer) From the viewpoint of suppressing retardation cracks during processing, the glass transition temperature (Tg2) of the second cured material layer is preferably 200° C. or lower, more preferably 150° C. or lower, and even more preferably 120° C. or lower. Also, it is preferably 40° C. or higher, more preferably 50° C. or higher, even more preferably 60° C. or higher, and particularly preferably 70° C. or higher. The glass transition temperature (Tg2) of the second cured material layer is measured by the method described in the Examples section below.

[0174] (Adhesive layer) The laminate 100 has a pressure-sensitive adhesive layer 70 on the side of the retardation layer 20 opposite to the first cured material layer 14. The pressure-sensitive adhesive layer can be composed of a pressure-sensitive adhesive composition whose main component is a (meth)acrylic, rubber, urethane, ester, silicone, or polyvinyl ether resin. Among these, a pressure-sensitive adhesive composition whose base polymer is a (meth)acrylic resin, which is excellent in transparency, weather resistance, heat resistance, etc., is preferred. The pressure-sensitive adhesive composition may be an active energy ray-curable or thermosetting type. The thickness of the pressure-sensitive adhesive layer is usually 3 μm or more and 30 μm or less, and preferably 3 μm or more and 25 μm or less.

[0175] The (meth)acrylic resin (base polymer) used in the pressure-sensitive adhesive composition is preferably a polymer or copolymer containing one or more (meth)acrylic acid esters as monomers, such as butyl (meth)acrylate, ethyl (meth)acrylate, isooctyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. It is preferable to copolymerize a polar monomer into the base polymer. Examples of polar monomers include monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, or an epoxy group, such as (meth)acrylic acid, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylate, and glycidyl (meth)acrylate.

[0176] The pressure-sensitive adhesive composition may contain only the base polymer, but usually further contains a crosslinking agent. Examples of crosslinking agents include divalent or higher metal ions that form metal carboxylates with carboxyl groups; polyamine compounds that form amide bonds with carboxyl groups; polyepoxy compounds or polyols that form ester bonds with carboxyl groups; and polyisocyanate compounds that form amide bonds with carboxyl groups. Among these, polyisocyanate compounds are preferred.

[0177] In one embodiment of the present invention, the amount of iodine in the pressure-sensitive adhesive layer after storing the optical laminate at a temperature of 80°C and a relative humidity of 90% for 250 hours is 900 mg / kg or less. The amount of iodine contained in the pressure-sensitive adhesive layer can be measured by the method described in the Examples. The amount of iodine refers to the content of elemental iodine in the pressure-sensitive adhesive layer. When the amount of iodine contained in the pressure-sensitive adhesive layer is 900 mg / kg or less, corrosion of the conductive layer can be suppressed. The amount of iodine contained in the pressure-sensitive adhesive layer is preferably 800 mg / kg or less, and more preferably 700 mg / kg or less.

[0178] (Method of manufacturing laminate) An example of a method for producing a laminate of the present invention will be described with reference to Fig. 3. As shown in Fig. 3(A), a linear polarizing plate 10 is produced by laminating a polarizer 13 and a thermoplastic resin film 11 via an adhesive layer 12. As shown in Fig. 3(B), a first retardation layer 30 including a first retardation layer 31, a first alignment layer 32, and a first base layer 33 is laminated with a second retardation layer 40 including a second retardation layer 43, a second alignment layer 42, and a second base layer 41 via a second cured product layer 50. As shown in Fig. 3(C), a retardation layer laminate 60 is produced by laminating the first base layer 33, the first alignment layer 32, the first retardation layer 31, the second cured product layer 50, the second retardation layer 43, the second alignment layer 42, and the second base layer 41 in this order. As shown in FIG. 3(D), the polarizer 13 side of the linear polarizing plate 10 and the first retardation layer 30 side of the retardation layer laminate 60 are laminated via the first cured product layer 14 to obtain a laminate 80.

[0179] A method for bonding the polarizer 13 and the thermoplastic resin film 11 includes applying an adhesive composition to either or both of the bonding surfaces of the polarizer 13 or the thermoplastic resin film 11, laminating the other bonding surface thereon, and curing the adhesive composition that constitutes the adhesive layer 12.

[0180] Examples of a method for bonding the first retardation layer 30 and the second retardation layer 40 include a method in which an active energy ray-curable adhesive composition is applied to either or both of the bonding surface of the first retardation layer 30 and the bonding surface of the second retardation layer 40, the other bonding surface is laminated thereon, and the active energy ray-curable adhesive constituting the second cured material layer 50 is cured. The active energy rays for curing the active energy ray-curable adhesive constituting the second cured material layer 50 can be irradiated from either or both of the first retardation layer 30 and the second retardation layer 40.

[0181] Examples of a method for bonding the linear polarizer 10 and the retardation layer laminate 60 include a method in which an active energy ray-curable adhesive composition is applied to either or both of the bonding surface of the linear polarizer 10 and the bonding surface of the retardation layer laminate 60, the other bonding surface is laminated thereon, and the active energy ray-curable adhesive constituting the first cured material layer 14 is cured. From the viewpoint of adhesion, the active energy ray-curable adhesive composition is preferably applied only to the bonding surface of the retardation layer laminate 60. Active energy rays for curing the active energy ray-curable adhesive constituting the first cured material layer 14 can be applied from either or both of the linear polarizer 10 and the retardation layer laminate 60.

[0182] Either or both of the lamination surfaces may be subjected to corona treatment, plasma treatment, or the like, or a primer layer may be formed. The aqueous adhesive composition and the active energy ray-curable adhesive composition may be applied by various coating methods, such as a doctor blade, a wire bar, a die coater, a comma coater, or a gravure coater.

[0183] The laminate of the present invention may be a laminate including the laminate 80 shown in Fig. 3(D) and a pressure-sensitive adhesive layer (the pressure-sensitive adhesive layer is laminated on the second retardation layer 40 side). Alternatively, it may be a laminate including a pressure-sensitive adhesive layer and a laminate obtained by peeling at least one of the first base layer 33 and the second base layer 41 from the laminate 80 shown in Fig. 3(D). Alternatively, it may be a laminate including a pressure-sensitive adhesive layer and a laminate obtained by peeling the first base layer 33 and the first alignment layer 32 from the laminate 80 shown in Fig. 3(D), or a laminate including a pressure-sensitive adhesive layer and a laminate obtained by peeling the second base layer 41 and the second alignment layer 42 from the laminate 80 shown in Fig. 3(D).

[0184] (Conductive layer) The optical laminate of the present invention can be laminated on a conductive layer formed on a substrate on the side of the pressure-sensitive adhesive layer 70. The conductive layer may be, for example, a conductive transparent metal oxide layer or a metal layer wiring layer.

[0185] Examples of conductive transparent metal oxide layers include ITO (tin-doped indium oxide) and AZO (aluminum-doped zinc oxide).

[0186] The metal constituting the metal wiring layer may be, for example, a layer containing at least one metal element selected from aluminum, copper, silver, iron, tin, zinc, platinum, nickel, molybdenum, chromium, tungsten, lead, titanium, palladium, indium, and alloys containing two or more of these metals. Among these, from the viewpoint of electrical conductivity, a layer containing at least one metal element selected from aluminum, copper, silver, and gold is preferred, and from the viewpoints of electrical conductivity and cost, a layer containing aluminum is more preferred. In the case of a copper-containing layer, a blackening treatment may be applied to prevent light reflection. The blackening treatment is a process of oxidizing the surface of the conductive layer to precipitate CuO or CuO. The conductive layer may be, for example, a layer containing graphene, zinc oxide, or the like.

[0187] The conductive layer is provided, for example, on a substrate. Examples of methods for forming a conductive layer on a substrate include sputtering. The substrate may be a transparent substrate constituting a liquid crystal cell included in a touch input element, or may be a glass substrate. The transparent substrate may be formed of, for example, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyethylene naphthalate, polyether sulfone, cyclic olefin copolymer, triacetyl cellulose, polyvinyl alcohol, polyimide, polystyrene, biaxially oriented polystyrene, or the like. The glass substrate may be formed of, for example, soda lime glass, low-alkali glass, or non-alkali glass. The conductive layer may be formed on the entire surface of the substrate, or on a portion thereof.

[0188] Examples of metal wiring layers include metal mesh, which is a layer of fine metal wiring lines, and layers in which metal nanoparticles or metal nanowires are added to a binder. The term "metal mesh" refers to a two-dimensional mesh structure formed from metal wiring lines. The shape of the openings (openings between wires or meshes) in the metal mesh is not particularly limited and may be, for example, polygonal (triangle, square, pentagon, hexagon, etc.), circular, elliptical, or irregular, and the openings may be the same or different. In a preferred embodiment, the openings in the metal mesh have the same shape, and are square or rectangular.

[0189] When the conductive layer is a metal wiring layer (particularly a metal mesh), the metal wiring may be arranged at predetermined intervals in the vertical and horizontal directions of the plane of the substrate. In this case, the openings may be filled with a resin (adhesive, etc.), or the metal wiring layer may be embedded in the resin (adhesive, etc.). When a resin, etc. is used, the conductive layer is composed of both the metal wiring and the resin (adhesive).

[0190] The line width of the metal wiring (particularly the metal mesh) is usually 10 μm or less, preferably 5 μm or less, and more preferably 3 μm or less, and is usually 0.1 μm or more, preferably 0.5 μm or more, and more preferably 1 μm or more. The line width of the metal wiring layer may be a combination of these upper and lower limit values, and is preferably 0.5 to 5 μm, and more preferably 1 to 3 μm.

[0191] The thickness of the conductive layer (conductive transparent metal oxide layer or metal wiring layer) is not particularly limited, but is usually 10 μm or less, preferably 3 μm or less, more preferably 1 μm or less, and particularly preferably 0.5 μm or less, and is usually 0.01 μm or more, preferably 0.05 μm or more, and more preferably 0.1 μm or more. The thickness of the conductive layer may be a combination of these upper and lower limits, and is preferably 0.01 to 3 μm, and more preferably 0.05 to 1 μm. Note that when the conductive layer is a metal wiring layer and the metal wiring layer is composed of both a resin (such as an adhesive) and metal wiring, the thickness of the conductive layer includes the thickness of the resin.

[0192] The method for preparing the conductive layer is not particularly limited, and the conductive layer may be formed by lamination of a metal foil, or by vacuum deposition, sputtering, wet coating, ion plating, inkjet printing, gravure printing, electrolytic plating, or electroless plating. Preferably, the conductive layer is formed by sputtering, inkjet printing, or gravure printing, and more preferably by sputtering.

[0193] The conductive layer (for example, a metal mesh) may have a function of generating a signal when the transparent substrate is touched in a touch panel, for example, and transmitting touch coordinates to an integrated circuit or the like.

[0194] Optical laminates having a conductive layer (e.g., a conductive transparent metal oxide layer, a metal wiring layer, etc.) are useful because they can be used in touch-input liquid crystal display devices having touch panel functions, etc. However, the dichroic dye (iodine) contained in the polarizer migrates to the conductive layer, causing the conductive layer to easily corrode. In particular, when a metal wiring layer such as a metal mesh is used, the conductive layer is more likely to corrode due to the narrow line width. However, the optical laminate of the present invention can effectively suppress the migration of the dichroic dye to the conductive layer and effectively prevent corrosion of the conductive layer.

[0195] (Application) The laminate can be used in image display devices. An image display device is a device having an image display panel and includes a light-emitting element or a light-emitting device as a light source. Examples of image 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 digital micromirror devices (DMDs)), and piezoelectric ceramic displays. Liquid crystal display devices include 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 image display devices may be image display devices that display two-dimensional images or stereoscopic image display devices that display three-dimensional images. In particular, polarizing plate composites that are circular polarizers can be effectively used in organic electroluminescence (EL) display devices that may have image display panels with bent portions.

[0196] The optical laminate can function as a circular polarizer or an antireflection film. The optical laminate can be disposed on the viewing side of the image display panel with the polarizing film facing the viewing side. The laminate is suitable as a circular polarizer or an antireflection film for use in an in-vehicle image display device. [Example]

[0197] The present invention will be described in more detail below with reference to examples. In the examples, "%" and "parts" are by mass % and mass parts unless otherwise specified.

[0198] (Metal corrosion resistance evaluation) The laminates obtained in the Examples and Comparative Examples were cut into test pieces measuring 25 mm x 50 mm and attached to the metal layer side of a metal-layered glass substrate via an adhesive layer. The metal-layered glass substrate was a glass substrate (manufactured by Geomatec Co., Ltd.) in which a metal aluminum layer approximately 500 nm thick was laminated to the surface of alkali-free glass by sputtering. The resulting optical laminates were stored in an oven at 85°C and 85% relative humidity for 250 hours. The condition of the metal layer in the area where the optical laminate was attached was observed through a magnifying glass from the polarizing plate surface, with light shining on the back of the glass substrate. The occurrence of pitting corrosion (holes with a diameter of 0.1 mm or more that can transmit light) was evaluated according to the following criteria. The results are shown in Tables 2 and 4.

[0199] ◎: The number of pits on the metal layer surface is 4 or less. ○: The number of pitting corrosion that occurred on the metal layer surface was 10 or less. ×: Many pitting corrosion occurred on the front surface of the metal layer.

[0200] (Evaluation of iodine content in adhesive layer) The optical laminates obtained in the examples and comparative examples were cut into test pieces measuring 25 mm x 50 mm and attached to alkali-free glass (EAGLE XG, manufactured by Corning Incorporated) via an adhesive layer. The optical laminates attached to the glass were stored in an oven at a temperature of 80°C and a relative humidity of 90% for 250 hours. The optical laminates were then peeled from the glass, and only the adhesive was scraped off. The amount of iodine (mg / kg) contained in the resulting adhesive was quantified using oxidation combustion ion chromatography using the following equipment and conditions. The results are shown in Tables 2 and 4.

[0201] (1) Sample combustion Equipment: Mitsubishi Chemical Analytech AQF-2100H Combustion conditions Combustion temperature: 1100℃ Gas flow rate: argon flow rate = 200 mL / min; Oxygen flow rate = 400 mL / min, Humidifying Air flow rate=100mL / min (2) Ion chromatograph Equipment: Thermo Fisher Scientific Integrion Column: Thermo Fisher Scientific IonPac AS19 Measurement conditions Eluent: KOH gradient Flow rate: 1.0mL / min Injection volume: 100μL Measurement mode: Suppressor type Detector: Electrical conductivity

[0202] (Adhesion measurement) The laminates prepared in the examples and comparative examples were cut into a size of 200 mm in length and 25 mm in width, and the adhesive layer surface of each cut piece was attached to a soda glass substrate. Next, a cutter blade was inserted between the polarizer and the λ / 2 retardation layer, and a 30 mm strip was peeled off from the edge in the longitudinal direction. The peeled portion was then gripped with the grip of a universal tensile tester (Shimadzu Corporation, "AG-1"). The test specimen in this state was subjected to a 180° peel test at a gripping speed of 300 mm / min in accordance with JIS K 6854-2:1999 "Adhesives - Peel Adhesion Strength Test Method - Part 2: 180° Peel" in an atmosphere of 23°C and 55% relative humidity. The average peel strength over a 170 mm length, excluding the 30 mm from the grip, was determined and evaluated according to the following criteria. The results are shown in Tables 2 and 4. 〇: 180° peel force is 1.0N or more △: 180° peel force is 0.5N or more and less than 1.0N

[0203] (Measurement of storage modulus and glass transition temperature of adhesive layer at 80°C) One side of a 50 μm thick cyclic polyolefin resin film was coated with one of the adhesives 1 to 5 described below using a coating machine (bar coater, manufactured by Daiichi Rika Co., Ltd.), and a 50 μm thick cyclic polyolefin resin film was laminated on the coated surface. Next, a "D bulb" manufactured by Fusion UV Systems was used to apply an integrated light dose of 1500 mJ / cm. 2 The adhesive layer was cured by irradiating it with ultraviolet light so that the maximum curing temperature was 100°C (UVB). This was then cut into a size of 5 mm x 30 mm, and the cyclic polyolefin resin film was peeled off to obtain a cured film of the adhesive. This cured film was held with its long side in the tensile direction using a dynamic viscoelasticity measuring device "DVA-220" manufactured by IT Measurement Control Co., Ltd., with the gripping tools spaced 2 cm apart. The tensile and contraction frequency was set to 10 Hz, and the heating rate was set to 10°C / min. Measurements were carried out over a temperature range from 25°C to 200°C, and the storage modulus at a temperature of 80°C was determined. In addition, from the results obtained in the above measurements, the storage modulus (E A ) and loss modulus (E B ) ratio (E B / E A The temperature at which the value of (x,y) reached its maximum was taken as the glass transition temperature. The results are shown in Tables 1 and 3.

[0204] (Evaluation of moisture permeability) A film with a pressure-sensitive adhesive layer was prepared in which a 5 μm thick acrylic pressure-sensitive adhesive layer 1 was formed on the surface of a 20 μm thick triacetyl cellulose film. The moisture permeability of the pressure-sensitive adhesive layer-attached film at a temperature of 80°C and a relative humidity of 90% was 5200 [g / (m 2 ·24hr)]. Adhesive 1 was applied to the surface of acrylic adhesive layer 1, and then the applied layer was cured by irradiating with ultraviolet light to form a 30 μm adhesive layer 1, thereby obtaining a laminate having a laminated structure of 30 μm adhesive layer 1 / 5 μm acrylic adhesive layer 1 / 20 μm triacetyl cellulose film. The resulting laminate was measured for moisture permeability (g / (m)) at a temperature of 40°C and a relative humidity of 90% by the cup method specified in JIS Z 0208. 2 The moisture permeability of each adhesive was measured by changing adhesive 1 to adhesives 2 to 5. The results are shown in Tables 1 and 3.

[0205] (Preparation of active energy ray-curable adhesive composition) The components shown in Table 1 were mixed in the blending ratios (units: parts by mass) shown in Table 1 and then degassed to prepare active energy ray-curable adhesive compositions (adhesives 1 and 2). The cationic polymerization initiator (B-1) was blended as a 50% propylene carbonate solution, and the solid content is shown in Table 1.

[0206] [Table 1]

[0207] (Cationically polymerizable compound (A)) A-1: 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Corporation) A-2: 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (trade name: EHPE3150, manufactured by Daicel Corporation) A-3: Neopentyl glycol diglycidyl ether (trade name: EX-211L, manufactured by Nagase ChemteX Corporation) A-4: 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane (trade name: OXT-221, manufactured by Toagosei Co., Ltd.) A-5: Bisphenol A epoxy resin (product name: EP-4100E, ADEKA Corporation, viscosity 13 Pa·s (temperature 25°C)) A-6: Aromatic-containing oxetane compound (product name: TCM-104, manufactured by TRONLY) (Photocationic Polymerization Initiator (B)) B-1: CPI-100P, manufactured by San-Apro Co., Ltd., 50% by weight solution (Photosensitizing Coagent (C)) C-1: 1,4-diethoxynaphthalene

[0208] (Production of Linear Polarizing Plate 1) A polyvinyl alcohol film having a thickness of 20 μm, a degree of polymerization of 2,400, and a degree of saponification of 99.9% or more was uniaxially stretched to a stretching ratio of 4.5 times on a roll heated to 125°C, and while maintaining the tension, it was immersed in water at 28°C for 30 seconds, and then immersed in a dye bath at 28°C containing 0.05 parts by mass of iodine and 5 parts by mass of potassium iodide per 100 parts by mass of water for 30 seconds. Next, the substrate was immersed for 110 seconds in a boric acid aqueous solution 1 at 64° C. containing 5.5 parts by mass of boric acid and 15 parts by mass of potassium iodide per 100 parts by mass of water. Next, the substrate was immersed for 30 seconds in a boric acid aqueous solution 2 at 67° C. containing 2.35 parts by mass of boric acid and 15 parts by mass of potassium iodide per 100 parts by mass of water. Thereafter, the film was washed with pure water at 10°C and dried at 80°C to obtain a polarizing film. The resulting polarizing film had a thickness of 7 μm.

[0209] Furthermore, a 25 μm thick cycloolefin film (COP film) with a hard coat layer was bonded to one side of the obtained polarizing film via a water-based adhesive, and dried at 90°C to obtain a linear polarizing plate 1 having a laminated structure of COP film / water-based adhesive (adhesive layer) / polarizer.

[0210] (Manufacture of Linear Polarizer 2) A linear polarizer 2 having a laminated structure of COP film / water-based adhesive (adhesive layer) / polarizer was obtained in the same manner as in the production of linear polarizer 1, except that the boric acid content in boric acid aqueous solution 2 was changed to 5.5 parts by mass.

[0211] (Production of λ / 2 retardation layer) The alignment film coating solution was applied to a transparent resin substrate and dried to perform a λ / 2 alignment treatment. Next, a coating solution containing a discotic liquid crystal compound was applied to the alignment surface, and the alignment of the liquid crystal compound was fixed by heating and UV irradiation, thereby forming a 2 μm-thick retardation layer on the transparent resin substrate.

[0212] (Production of λ / 4 retardation layer) A coating solution containing a rod-shaped polymerizable nematic liquid crystal monomer was applied to a transparent resin substrate for λ / 4 alignment, which had an alignment film that had been rubbed, and solidified while maintaining the refractive index anisotropy, thereby obtaining a retardation layer with a thickness of 1 μm on the transparent resin substrate.

[0213] (Production of retardation layer laminate) The liquid crystal layer sides of the λ / 2 retardation layer and the λ / 4 retardation layer were subjected to corona treatment. The λ / 2 retardation layer and the λ / 4 retardation layer were arranged so that the angle between their slow axes was 60°, and the liquid crystal layers were bonded together using adhesive 1 with a laminator to a thickness of 3 μm to obtain a laminate. The laminate was irradiated from the λ / 4 retardation layer side with an ultraviolet irradiation device (manufactured by Fusion UV Systems Co., Ltd.) with an accumulated light amount of 400 mJ / cm 2 The adhesive 1 was cured by irradiating it with ultraviolet light (UV-B) to form a second cured layer, thereby obtaining a retardation layer laminate having a laminated structure of "λ / 2 retardation layer" (first retardation layer) / adhesive layer (second cured layer) / "λ / 4 retardation layer" (second retardation layer).

[0214] Example 1 The alignment film and transparent resin substrate on the λ / 2 retardation layer side of the obtained retardation layer laminate were peeled off, and the surface of the linear polarizing plate 1 opposite to the thermoplastic resin film was attached to the liquid crystal layer of the λ / 2 retardation layer using adhesive 2. The thickness of the first cured product layer made of adhesive 2 was 3 μm, and the angle formed between the transmission axis of the polarizer and the slow axis of the λ / 2 retardation layer was 15°. Next, the alignment film and transparent resin substrate on the λ / 4 retardation layer side were peeled off to obtain a laminate having a laminated structure of thermoplastic resin film / water-based adhesive (adhesive layer) / polarizer / first cured material layer / "λ / 2 retardation layer" (first retardation layer) / second cured material layer / "λ / 4 retardation layer" (second retardation layer). A 15 μm-thick acrylic pressure-sensitive adhesive layer 1 was laminated on the surface of the second retardation layer of the obtained laminate to obtain the laminate of Example 1. The obtained laminate was evaluated for metal corrosion resistance, the amount of iodine in the pressure-sensitive adhesive layer, and adhesion. The results are shown in Table 2.

[0215] <Comparative Example 1> The alignment film and transparent resin substrate on the λ / 2 retardation layer side of the obtained retardation layer laminate were peeled off, and the surface of the linear polarizer 1 opposite to the thermoplastic resin film was attached to the liquid crystal layer of the λ / 2 retardation layer using a 5 μm-thick acrylic pressure-sensitive adhesive layer 2 (storage modulus at 80° C.: 0.5 MPa, glass transition temperature: −45° C.). The angle between the transmission axis of the polarizer and the slow axis of the λ / 2 retardation layer was 15°. Next, the alignment film and transparent resin substrate on the λ / 4 retardation layer side were peeled off to obtain a laminate having a laminated structure of thermoplastic resin film / water-based adhesive (adhesive layer) / polarizer / adhesive layer / "λ / 2 retardation layer" (first retardation layer) / second cured product layer / "λ / 4 retardation layer" (second retardation layer). A 15 μm-thick acrylic adhesive layer 1 was laminated on the surface of the second retardation layer of the obtained laminate to obtain a laminate of Comparative Example 1. The obtained laminate was evaluated for metal corrosion resistance, the amount of iodine in the adhesive layer, and adhesion. The results are shown in Table 2.

[0216] [Table 2]

[0217] (Preparation of active energy ray-curable adhesive composition) The components shown in Table 3 were mixed in the blending ratios (units: parts by mass) shown in Table 3 and then degassed to prepare active energy ray-curable adhesive compositions (adhesives 3 to 5). The cationic polymerization initiator (B-2) was blended as a 50% propylene carbonate solution, and the solid content is shown in Table 3.

[0218] [Table 3]

[0219] (Cationically polymerizable compound (A)) A-7: 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Corporation) A-8: 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (trade name: EHPE3150, manufactured by Daicel Corporation) A-9: Neopentyl glycol diglycidyl ether (trade name: ED-523T, manufactured by ADEKA Corporation) A-10: 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane (trade name: OXT-221, manufactured by Toagosei Co., Ltd.) A-11: A compound represented by the following formula: [ka] (Photocationic Polymerization Initiator (B)) B-2: CPI-100P, manufactured by San-Apro Co., Ltd., 50% by weight solution (Photosensitizing Coagent (C)) C-2: 1,4-diethoxynaphthalene

[0220] <Examples 2 to 4> Laminates were obtained in the same manner as in Example 1, except that adhesive 2 was replaced with adhesives 3 to 5. The resulting laminates were evaluated for metal corrosion resistance, the amount of iodine in the pressure-sensitive adhesive layer, and adhesion. The results are shown in Table 4. The laminate of Example 2 had a laminated structure of thermoplastic resin film / water-based adhesive (adhesive layer) / polarizer / first cured product layer (cured product layer of adhesive 3) / "λ / 2 retardation layer" (first retardation layer) / second cured product layer (cured product layer of adhesive 1) / "λ / 4 retardation layer" (second retardation layer) / 15 μm pressure-sensitive adhesive layer. The laminate of Example 3 has a laminated structure of thermoplastic resin film / water-based adhesive (adhesive layer) / polarizer / first cured product layer (cured product layer of adhesive 4) / "λ / 2 retardation layer" (first retardation layer) / second cured product layer (cured product layer of adhesive 1) / "λ / 4 retardation layer" (second retardation layer) / 15 μm pressure-sensitive adhesive layer. The laminate of Example 4 has a laminated structure of thermoplastic resin film / water-based adhesive (adhesive layer) / polarizer / first cured product layer (cured product layer of adhesive 5) / "λ / 2 retardation layer" (first retardation layer) / second cured product layer (cured product layer of adhesive 1) / "λ / 4 retardation layer" (second retardation layer) / 15 μm pressure-sensitive adhesive layer.

[0221] <Comparative Example 2> A laminate was obtained in the same manner as in Example 1, except that Adhesive 2 was replaced with Adhesive 1. The obtained laminate was evaluated for metal corrosion resistance, the amount of iodine in the pressure-sensitive adhesive layer, and adhesion. The results are shown in Table 4. The laminate of Comparative Example 2 had a laminate structure of thermoplastic resin film / water-based adhesive (adhesive layer) / polarizer / first cured product layer (cured product layer of adhesive 1) / "λ / 2 retardation layer" (first retardation layer) / second cured product layer (cured product layer of adhesive 1) / "λ / 4 retardation layer" (second retardation layer) / 15 μm pressure-sensitive adhesive layer.

[0222] [Table 4] [Explanation of symbols]

[0223] REFERENCE SIGNS LIST 10 Linear polarizing plate, 11 Thermoplastic resin film, 12 Adhesive layer, 13 Polarizer, 14 First cured product layer, 20 Retardation layer, 30 First retardation layer, 31 Retardation layer, 32 Alignment layer, 33 Base layer, 40 Second retardation layer, 41 Base layer, 42 Alignment layer, 43 Retardation layer, 50 Second cured product layer, 60 Retardation laminate, 70 Pressure-sensitive adhesive layer, 80 Optical laminate, 100 Optical laminate

Claims

1. an optical laminate including a polarizer, a first cured product layer, a retardation layer, and a pressure-sensitive adhesive layer in this order; the polarizer is made of a polyvinyl alcohol resin containing iodine, the first cured product layer is a cured product of an active energy ray-curable adhesive composition, The retardation layer is a layer including a first retardation layer, a second cured material layer, and a second retardation layer in this order from the first cured material layer side, the first retardation layer and the second retardation layer are each independently formed of only a retardation-exhibiting layer which is a polymer of a polymerizable liquid crystal compound, the pressure-sensitive adhesive layer has an iodine content of 900 mg / kg or less after storing the optical laminate at a temperature of 80°C and a relative humidity of 90% for 250 hours; the polarizer and the first cured product layer are in direct contact with each other, the first cured material layer and the first retardation layer are in direct contact with each other, the first retardation layer and the second cured material layer are in direct contact with each other, the second cured material layer and the second retardation layer are in direct contact with each other, the second retardation layer and the pressure-sensitive adhesive layer are in direct contact with each other, The active energy ray-curable adhesive composition contains an epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule, and a polyfunctional oxetane compound (A5-1), and the content of the polyfunctional oxetane compound (A5-1) is greater than the content of the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule.

2. The optical laminate according to claim 1 , wherein the second cured material layer is an active energy ray-cured material layer.

3. The moisture permeability of the first cured material layer at a thickness of 30 μm at a temperature of 80° C. and a relative humidity of 90% is 1500 [g / (m ２ 3. The optical laminate according to claim 1, wherein the curing time is 24 hours or less.

4. 4. The optical laminate according to claim 1, wherein the first cured product layer has a storage modulus of 300 MPa or more at a temperature of 80°C.

5. The optical laminate according to any one of claims 1 to 4, wherein the second cured product layer has a storage modulus of 20 MPa or more at a temperature of 80°C.

6. The storage modulus (E １ ) is the storage modulus (E ２ 6. The optical laminate according to claim 1, wherein the thickness of the optical laminate is greater than 1 / 2 mm.

7. The glass transition temperature (Tg １ 7. The optical laminate according to claim 1, wherein the temperature is higher than 60°C.

8. The glass transition temperature (Tg ２ 8. The optical laminate according to claim 1, wherein the temperature is 40° C. or higher.

9. The glass transition temperature (Tg １ ) is the glass transition temperature (Tg ２ 9. The optical laminate according to claim 1, wherein the thickness of the optical laminate is greater than 1 / 2 mm.

10. 10. The optical laminate according to claim 1, wherein the content ratio (mass ratio) of the polyfunctional oxetane compound (A5-1) to the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule is the polyfunctional oxetane compound (A5-1) / the epoxy compound (A2-1) containing a tricyclic fused ring and two glycidyl ether groups in the molecule = 1.5 / 1 to 5 / 1.

Images