Laminate

Abstract

To provide a laminate which comprises a polarization film and a phase difference layer, in which adhesiveness between the polarization film and the phase difference layer is satisfactory, and of which the durability is improved.SOLUTION: The present invention relates to a laminate 100 in which a polarization film 11, a first cured product layer 12 and a first phase difference layer 13 are successively stacked. In the laminate, the first cured product layer contains a cured product of a first active energy ray curable composition, the first active energy ray curable composition contains (A) a cationic polymerizable compound and (B) a photo-cationic polymerization initiator. The (B) photo-cationic polymerization initiator is contained in 1 mass% or more and 10 mass% or less with respect to the cationic polymerizable compound (A) in 100 mass%, and the cationic polymerizable compound (A) contains an oxetane compound in 45 mass% or more with a total mass of the cationic polymerizable compound (A) defined as a reference.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminate, and further to an image display device including the same. [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 laminate composed of a polarizing film and a retardation layer is known as an optical laminate having antireflection properties. Patent Document 1 proposes a laminate in which a polarizing film and a retardation layer are bonded together with an adhesive layer made of an active energy ray-curable adhesive composition. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 183333 Summary of the Invention [Problem to be solved by the invention]

[0005] In the laminate proposed in Patent Document 1, the adhesion between the polarizing film and the retardation layer is insufficient, and the durability is also unsatisfactory.

[0006] An object of the present invention is to provide a laminate comprising a polarizing film and a retardation layer, which has good adhesion between the polarizing film and the retardation layer and is excellent in durability. [Means for solving the problem]

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

[20] . [1] A laminate in which a polarizing film, a first cured material layer, and a first retardation layer are laminated in this order, wherein the thickness of the first retardation layer is 10 μm or less, the first cured material layer contains a cured product of a first active energy ray-curable composition, and the first active energy ray-curable composition is (A) a cationic polymerizable compound and (B) a photocationic polymerization initiator, the (B) photocationic polymerization initiator is contained in an amount of 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the (A) cationically polymerizable compound, The cationically polymerizable compound (A) contains an oxetane compound in an amount of 45 mass % or more based on the total mass of the cationically polymerizable compound (A). [2] The first active energy ray-curable composition (C) a photosensitizer showing a maximum absorption at wavelengths longer than 400 nm, in an amount of 0.1 parts by mass or more and 3.0 parts by mass or less per 100 parts by mass of the cationically polymerizable compound (A); Contains 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 laminate according to [1], comprising an anthracene-based compound represented by the formula: [3] The laminate according to [1] or [2], wherein the oxetane compound is at least one selected from the group consisting of 3-ethyl-3-hydroxymethyloxetane, xylylenebisoxetane, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, and 3-ethyl-3-(cyclohexyloxymethyl)oxetane. [4] The laminate according to any one of [1] to [3], wherein the cationically polymerizable compound (A) contains an alicyclic epoxy compound in an amount of 10% by mass or more and 50% by mass or less, based on the total mass of the cationically polymerizable compound (A). [5] The laminate according to any one of [1] to [4], wherein the photocationic polymerization initiator (B) is at least one ionic compound selected from the group consisting of aromatic sulfonium salts and aromatic iodonium salts. [6] The laminate according to any one of [1] to [5], wherein the first active energy ray-curable composition has a viscosity at 25°C of 200 mPa·s or less. [7] The laminate according to any one of [1] to [6], wherein the first active energy ray-curable composition satisfies the following formula (1): (J A / J B )×100≧60(%) (1) [J A represents the amount of heat (unit: mJ / g) measured by a differential scanning calorimeter when the first active energy ray-curable composition is irradiated with ultraviolet light having a peak at a wavelength of 365 nm through a substrate having 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, J B represents the amount of heat (mJ / g) measured by a differential scanning calorimeter when the first active energy ray-curable composition is irradiated with ultraviolet light having a peak at a wavelength of 365 nm without passing through a substrate.] [8] The laminate according to any one of [1] to [7], wherein the storage modulus of the first cured product layer at 80°C is 300 MPa or more. [9] The laminate according to any one of [1] to [8], wherein the first cured product layer has a thickness of 0.5 μm or more and 10 μm or less.

[10] The laminate according to any one of [1] to [9], wherein the first retardation layer has a light transmittance of 0% or more and 50% or less at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm.

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

[10] , wherein the first retardation layer 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.

[12] A second cured material layer and a second retardation layer are laminated in this order on the side of the first retardation layer opposite to the first cured material layer, The laminate according to any one of [1] to

[11] , wherein the second cured product layer contains a cured product of a second active energy ray-curable composition, and at least one of the first retardation layer and the second retardation layer 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.

[13] The laminate according to

[12] , wherein the first retardation layer is a half-wave retardation layer, and the second retardation layer is a quarter-wave retardation layer.

[14] The laminate according to

[12] , wherein the first retardation layer is a half-wave retardation layer or a quarter-wave retardation layer, and the second retardation layer is a positive C plate.

[15] The laminate according to any one of

[12] to

[14] , wherein at least one of the first retardation layer and the second retardation layer includes a liquid crystal layer capable of generating retardation.

[16] The laminate according to any one of

[12] to

[15] , wherein at least one of the first retardation layer and the second retardation layer has a thickness of 0.5 μm or more and 50 μm or less.

[17] A circularly polarizing plate comprising the laminate according to any one of [1] to

[16] .

[18] An image display device comprising: an image display panel; and the laminate according to any one of [1] to

[17] , which is disposed on the viewing side of the image display panel.

[19] The image display device according to

[18] , wherein the laminate is oriented so that the polarizing film is on the viewing side.

[20] An organic electroluminescence display device comprising the image display device according to

[18] or

[19] . [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a laminate comprising a polarizing film and a retardation layer, which has good adhesion between the polarizing film and the retardation layer and is excellent in durability. [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] 1 is a schematic cross-sectional view showing a laminate of the present invention. [Figure 4] 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] <Laminate> The laminate of the present invention will be described with reference to Fig. 1. The laminate 100 shown in Fig. 1 includes a polarizing film 11, a first cured product layer 12, and a first retardation layer 13 laminated in this order. The thickness of the laminate 100 may be, for example, 3 μm or more and 100 μm or less, and preferably 3 μm or more and 60 μm or less.

[0012] The laminate 100 may be elongated or sheet-like. When the laminate 100 is sheet-like, the shape of the laminate 100 in a planar view may be substantially rectangular. A planar view refers to a view from the thickness direction of the 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 recess (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.

[0013] There are no particular limitations on the size of the laminate 100. When the laminate 100 is in the form of a sheet 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.

[0014] (polarizing film) The polarizing film 11 can be an absorption polarizer that absorbs linearly polarized light with a vibration plane parallel to its absorption axis and transmits linearly polarized light with a vibration plane perpendicular to the absorption axis (parallel to its transmission axis). A suitable polarizing film 11 is a polarizer in which a dichroic dye is adsorbed and aligned on a uniaxially stretched polyvinyl alcohol-based resin film. The polarizing film 11 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 with water after the crosslinking liquid treatment.

[0015] 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.

[0016] In this specification, "(meth)acrylic" means at least one selected from acrylic and methacrylic. The same applies to "(meth)acryloyl", "(meth)acrylate", etc.

[0017] 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.

[0018] A film formed from such a polyvinyl alcohol-based resin is used as the raw film for the polarizer. The method for forming the polyvinyl alcohol-based resin is not particularly limited, and known methods can be used. The thickness of the polyvinyl alcohol-based raw film is not particularly limited, but in order to make the thickness of the polarizer 15 μm or less, it is preferable to use one that is 5 μm or more and 35 μm or less. More preferably, it is 20 μm or less.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] The thickness of the polarizing film 11 is usually 30 μm or less, preferably 28 μm or less, more preferably 20 μm or less, even more preferably 15 μm or less, and particularly preferably 10 μm or less. The thickness of the polarizing film 11 is usually 2 μm or more, and preferably 3 μm or more.

[0024] The polarizing film 11 may be a cured film formed by polymerizing a liquid crystal compound, in which a dichroic dye is oriented, as described in, for example, JP 2016-170368 A. The dichroic dye may have absorption in the wavelength range of 380 nm to 800 nm, and organic dyes are preferred. Examples of dichroic dyes include azo compounds. The liquid crystal compound is a liquid crystal compound that can be polymerized while remaining oriented, and may have a polymerizable group in the molecule. Alternatively, a polarizer may be formed from a dichroic dye having liquid crystal properties, as described in WO 2011 / 024891.

[0025] (1st cured material layer) The first cured material layer 12 is disposed between the polarizing film 11 and the first retardation layer 13 to bond the polarizing film 11 and the first retardation layer 13. The first cured material layer 12 contains a cured product of the first active energy ray-curable composition. When the first cured material layer 12 contains a cured product of the first active energy ray-curable composition, good durability and adhesion tend to be easily obtained. In the present invention, the durability and adhesion are evaluated according to the methods described in the Examples section below.

[0026] The thickness of the first cured material layer 12 may be, for example, 10 μm or less, preferably 8 μm or less, more preferably 7 μm or less, even more preferably 6 μm or less, and particularly preferably 4 μm or less. The thickness of the first cured material layer 12 may be, for example, 0.5 μm or more, preferably 1 μm or more, and more preferably 2 μm or more.

[0027] (First active energy ray-curable composition) The first active energy ray-curable composition is a cationically polymerizable composition that is cured by irradiation with active energy rays. The first active energy ray-curable composition contains 100 parts by mass of a cationically polymerizable compound (A) and 1 to 10 parts by mass of a photocationic polymerization initiator (B) relative to 100 parts by mass of the cationically polymerizable compound (A). The first active energy ray-curable composition preferably further contains 0.1 to 3.0 parts by mass of a photosensitizer (C) that exhibits maximum absorption at wavelengths longer than 400 nm relative to 100 parts by mass of the cationically polymerizable compound (A).

[0028] (Cationically polymerizable compound (A)) The cationically polymerizable compound (A) is a component that can undergo cationic polymerization and harden when irradiated with active energy rays. The adhesive strength is developed by the polymerization and hardening of the cationically polymerizable compound (A). The cationically polymerizable compound (A) contains 45 mass% or more of an oxetane compound (A1) based on the total mass of the cationically polymerizable compound (A). By containing 45 mass% or more of the oxetane compound (A1) in the first active energy ray-hardenable composition, the viscosity of the active energy ray-hardenable composition decreases, making it easier to apply a thin film, and the elastic modulus of the cured product is improved, tending to make it easier to obtain good durability.

[0029] (Oxetane compound (A1)) In this specification, the oxetane compound (A1) is a compound having an oxetanyl group, and may be an aliphatic compound, an alicyclic compound, or an aromatic compound. The oxetane compound (A1) in this specification is a compound having no epoxy group. The oxetane compound (A1) may be a monofunctional oxetane compound having only one oxetanyl group, or a polyfunctional oxetane compound having two or more oxetanyl groups. The oxetane compound (A1) is preferably a polyfunctional oxetane compound, and more preferably a bifunctional oxetane compound having two oxetanyl groups.

[0030] Specific examples of the oxetane compound (A1) 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 (A1) include 3-ethyl-3-(methyl) 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 (A1), one type of oxetane compound may be used alone, or different types may be used in combination. Among these, at least one selected from the group consisting of 3-ethyl-3-hydroxymethyloxetane, xylylenebisoxetane, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, and 3-ethyl-3-(cyclohexyloxymethyl)oxetane is preferred.

[0031] As the oxetane compound (A1), 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.

[0032] The content of the oxetane compound (A1) in the cationically polymerizable compound (A) is 45% by mass or more, preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more, based on the total mass of the cationically polymerizable compound (A). The content of the oxetane compound (A1) in the cationically polymerizable compound (A) may be, for example, 90% by mass or less, preferably 80% by mass or less, and even more preferably 75% by mass or less. When the content of the oxetane compound (A1) is 90% by mass or less, a decrease in adhesion tends to be less likely to occur. Furthermore, when the oxetane compound (A1) contains a polyfunctional oxetane compound and a monofunctional oxetane compound, the polyfunctional oxetane compound preferably accounts for 50 mass% or more, more preferably 60 mass% or more, and even more preferably 70 mass% or more of the total mass of the oxetane compound (A1).

[0033] (Other cationically polymerizable compounds) The cationically polymerizable compound (A) may further contain at least one selected from the group consisting of an alicyclic epoxy compound (A2), an aliphatic epoxy compound (A3), and an aromatic epoxy compound (A4).

[0034] When the cationic polymerizable compound (A) contains an alicyclic epoxy compound (A2), the content of the alicyclic epoxy compound (A2) may be, for example, 10 to 50 parts by mass, preferably 10 to 40 parts by mass, more preferably 10 to 35 parts by mass, and even more preferably 10 to 30 parts by mass, per 100 parts by mass of the cationic polymerizable compound (A). When the content of the alicyclic epoxy compound (A2) is 10 parts by mass or more, the curing rate of the cationic polymerizable compound tends to be less likely to decrease. Furthermore, when the content of the alicyclic epoxy compound (A2) is 50 parts by mass or less, the viscosity increase of the cationic polymerizable compound is suppressed, and thin-film coating tends to be easier. When the cationically polymerizable compound (A) contains an aliphatic epoxy compound (A3), the content of the aliphatic epoxy compound (A3) may be, for example, 1 part by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the cationically polymerizable compound (A), and from the viewpoint of adhesion, is preferably 2.5 parts by mass or more and 40 parts by mass or less, and more preferably 5 parts by mass or more and 30 parts by mass or less. When the cationically polymerizable compound (A) contains an aromatic epoxy compound (A4), the content of the aromatic epoxy compound (A4) may be, for example, 10 to 50 parts by mass, preferably 15 to 40 parts by mass, and more preferably 20 to 30 parts by mass, per 100 parts by mass of the cationically polymerizable compound (A). When the content of the aromatic epoxy compound (A4) is 50 parts by mass or less, a decrease in adhesion tends to be less likely to occur. The curing rate of the cationically polymerizable compound (A) is improved by using an oxetane compound (A1) in combination with an alicyclic epoxy compound (A2). The ratio of oxetane compound (A1):alicyclic epoxy compound (A2) is 4:1 to 1:1, more preferably 3:1 to 1:1, and even more preferably 2:1 to 1:1. Within the above range, curing proceeds efficiently, and the resulting cured product has a dense crosslinked structure.

[0035] The first active energy ray-curable composition preferably does not contain a solvent. Each component will be described in detail below.

[0036] (Alicyclic epoxy compound (A2)) The alicyclic epoxy compound (A2) is a compound having one or more alicyclic epoxy groups. The alicyclic epoxy compound (A2) may further have an epoxy group other than the alicyclic epoxy group, so long as it has 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):

[0037] [ka]

[0038] 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 group (CH2) and the resulting group is bonded to another chemical structure can be an alicyclic epoxy compound (A2). m One or more hydrogen atoms in the alicyclic epoxy compound (A2) may be appropriately substituted with a linear alkyl group such as a methyl group or an ethyl group. The curing rate of the first active energy ray-curable composition can be adjusted by the alicyclic epoxy compound (A2).

[0039] Specific examples of the alicyclic epoxy compound (A2) 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.

[0040] Among the alicyclic epoxy compounds (A2), 3,4-epoxycyclohexylmethyl and 3,4-epoxycyclohexanecarboxylate are preferably used because they have suitable curability and are available at relatively low cost. As the alicyclic epoxy compound (A2), one type of alicyclic epoxy compound may be used alone, or different types may be used in combination.

[0041] As the alicyclic epoxy compound (A2), commercially available products can be used, and examples thereof include the "Celloxide (registered trademark)" series and "EHPE3150" and "Cyclomer (registered trademark)" sold by Daicel Corporation, and the "Cyracure UVR" series sold by The Dow Chemical Company, respectively, under their trade names.

[0042] In the present invention, the aliphatic epoxy compound (A3) includes a monofunctional aliphatic epoxy (A3-1) having one epoxy group, and a polyfunctional aliphatic epoxy (A3-2) having two or more epoxy groups. From the viewpoint of maintaining the cohesive strength of the cured product and improving adhesion, the polyfunctional aliphatic epoxy is preferred.

[0043] The monofunctional aliphatic epoxy (A3-1) can adjust the viscosity of the first active energy ray-curable composition. Examples of the monofunctional aliphatic epoxy (A3-1) 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 aliphatic epoxy (A3-1), one type of monofunctional epoxy compound may be used alone, or different types may be used in combination.

[0044] The polyfunctional aliphatic epoxy (A3-2) is a compound having two or more epoxy groups and no aromatic ring. However, the polyfunctional aliphatic epoxy (A3-2) referred to in this specification does not include compounds having an alicyclic epoxy group, which are included in the alicyclic epoxy compound (A2). The polyfunctional aliphatic epoxy (A3-2) can adjust the adhesion of the cured adhesive layer.

[0045] The polyfunctional aliphatic epoxy (A3-2) 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 (A3), an active energy ray-curable adhesive having low viscosity and easy application can be obtained.

[0046] [ka]

[0047] 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 -C n 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.

[0048] The divalent alicyclic hydrocarbon group may be, for example, a divalent alicyclic hydrocarbon group having 4 to 8 carbon atoms, and examples thereof include divalent groups represented by the following formula (b-1).

[0049] [ka]

[0050] 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.

[0051] 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, and 2-methyl-2,4-pentanediol. Examples of suitable alkylene glycols include alkanediols such as 1,6-hexanediol, 2,4-diethyl-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 and cyclohexanedimethanol.

[0052] From the viewpoint of obtaining a first active energy ray-curable composition having low viscosity and easy application, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and neopentyl glycol diglycidyl ether are preferred. As the aliphatic epoxy compound (A3), one type of aliphatic epoxy compound may be used alone, or different types may be used in combination.

[0053] The aliphatic epoxy compound (A3) may be a commercially available product, such as "EP-4088S" or "ED-523T" (both manufactured by ADEKA Corporation), "EX-211L" or "EX-212L" (all manufactured by Nagase ChemteX Corporation).

[0054] Aromatic epoxy compounds (A4) The aromatic epoxy compound (A4) includes a monofunctional aromatic epoxy (A4-1) having one epoxy group and a polyfunctional aromatic epoxy (A4-2) having two or more epoxy groups, but the aromatic epoxy compound (A4) in this specification excludes a compound having an alicyclic epoxy group in the molecule, which is included in the alicyclic epoxy compound (A2).

[0055] Examples of monofunctional aromatic epoxies (A4-1) include monoglycidyl ethers of monohydric phenols such as phenol, cresol, and butylphenol, or bisphenol derivatives such as bisphenol A and bisphenol F, or their alkylene oxide adducts; 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 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.

[0056] The monofunctional aromatic epoxy (A4-1) can be a commercially available product, such as "EX-142", "EX-146", "EX-147", or "EX-121" (all manufactured by Nagase ChemteX Corporation).

[0057] Specific examples of polyfunctional aromatic epoxies (A4-2) 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 (A5) 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 (A5) may be used alone or in combination with different compounds.

[0058] The polyfunctional aromatic epoxy (A4-2) 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 "jE R828EL" (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).

[0059] The above-mentioned curable components [oxetane compound (A1), alicyclic epoxy compound (A2), aliphatic epoxy compound (A3), aromatic epoxy compound (A4)] are preferably used without being diluted with an organic solvent or the like, so that the first active energy ray-curable composition is solvent-free.

[0060] The above-mentioned curable component is usually liquid at room temperature, has appropriate fluidity even without a solvent, and is selected to provide appropriate adhesive strength. The first active energy ray-curable composition containing an appropriate photocationic polymerization initiator can eliminate the need for drying equipment to evaporate the solvent in the step of bonding the linear polarizer and the 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 speed, thereby improving the production speed.

[0061] (Other curing components) The cationically polymerizable compound (A) contained in the first active energy ray-curable composition is not limited to the above-mentioned curable components, and may contain a cationically polymerizable curable component other than the above-mentioned cationically polymerizable curable components, and a radically polymerizable curable component. Examples of the radically polymerizable curable component include an acrylic compound.

[0062] However, since radical polymerization tends to result in large cure shrinkage, the first active energy ray-curable composition preferably contains only a cationically polymerizable curable component as the cationically polymerizable compound (A).

[0063] (Photocationic Polymerization Initiator (B)) The first active energy ray-curable composition contains the photocationic polymerization initiator (B), and thereby can form an adhesive layer by curing the cationically polymerizable compound (A) through cationic polymerization upon irradiation with active energy rays.

[0064] By including 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 lead to increased hygroscopicity of the cured product and reduced 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 cationic polymerizable compound (A). The content of the cationic photopolymerization initiator (B) in the first active energy ray-curable composition is preferably 1.5 to 8 parts by mass, more preferably 2 to 6 parts by mass, per 100 parts by mass of the total amount of the cationic polymerizable compound (A).

[0065] The cationic photopolymerization 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 cationic polymerizable compound (A). Because the cationic photopolymerization initiator (B) acts catalytically in the presence of light, it exhibits excellent storage stability and workability even when mixed with the cationic polymerizable compound (A). Examples of compounds that generate cationic species or Lewis acids upon irradiation with active energy rays and can be used as the cationic photopolymerization initiator (B) include aromatic diazonium salts; onium salts such as aromatic iodonium salts and aromatic sulfonium salts; and iron-arene complexes. The cationic photopolymerization initiator (B) is preferably at least one ionic compound selected from the group consisting of aromatic sulfonium salts and aromatic iodonium salts.

[0066] Examples of aromatic diazonium salts include benzenediazonium hexafluoroantimonate, benzenediazonium hexafluorophosphate, and benzenediazonium hexafluoroborate.

[0067] Examples of aromatic iodonium salts include diphenyliodonium tetrakis(pentafluorophenyl)borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, and di(4-nonylphenyl)iodonium hexafluorophosphate.

[0068] 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.

[0069] Examples of iron-arene complexes include xylene-cyclopentadienyliron(II) hexafluoroantimonate, cumene-cyclopentadienyliron(II) hexafluorophosphate, and xylene-cyclopentadienyliron(II) tris(trifluoromethylsulfonyl)methanide.

[0070] 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.

[0071] 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.

[0072] (Photosensitizer (C)) By including a photosensitizer (C) (hereinafter also referred to as photosensitizer (C)) that exhibits maximum absorption at wavelengths longer than 400 nm in the first active energy ray-curable composition, the curability of the adhesive can be improved compared to when the first active energy ray-curable composition does not contain the photosensitizer (C). Furthermore, when adhering a linear polarizer to a retardation layer laminate (described later), even if the retardation layer or the adhesive layer between the retardation layers has low UV transmittance, the active energy ray-curable adhesive composition can be cured by irradiating UV light from the retardation layer side. Furthermore, linear polarizers placed on the viewing side often contain a UV absorber, and conventionally, irradiating UV light from the linear polarizer side has not been able to sufficiently cure the active energy ray-curable adhesive composition. However, by using a specific amount of photosensitizer (C) as in the present invention, it is also possible to cure the active energy ray-curable adhesive composition by irradiating UV light from the linear polarizer side.

[0073] 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 above cationic photopolymerization initiator (B) exhibits a maximum absorption in the wavelength region around 300 nm or shorter, and generates cationic species or Lewis acids in response to light of a wavelength in that vicinity, thereby initiating cationic polymerization of a cationically polymerizable curable component, but the anthracene compound represented by general formula (I) exhibits a maximum absorption in the wavelength region longer than 400 nm, and therefore can also respond to light of a longer wavelength.

[0074] 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:

[0075] The content of the photosensitizer (C) in the first active energy ray-curable composition is preferably 0.1 parts by mass or more and 5.0 parts by mass or less, more preferably 0.5 parts by mass or more and 3.0 parts by mass or less, relative to 100 parts by mass of the total amount of the cationically polymerizable compound (A). (Photosensitizing Coagent (D)) The first active energy ray-curable composition may contain a photosensitizing aid (D). The photosensitizing aid (D) is preferably a naphthalene-based photosensitizing aid.

[0076] 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:

[0077] By including a naphthalene-based photosensitizing aid in the first active energy ray-curable composition, the curing rate of the adhesive can be improved compared to when the naphthalene-based photosensitizing aid is not included. 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 the cationically polymerizable compound (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 the cationically polymerizable compound (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 the cationically polymerizable compound (A).

[0078] (Additive component (E)) The first active energy ray-curable composition may contain an additive component (E) as an optional other component, 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 control agent, a plasticizer, an antifoaming agent, a leveling agent, a dye, and an organic solvent.

[0079] 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 cationically polymerizable compound (A).

[0080] The above-mentioned cationic photopolymerization initiator (B), photosensitizer (C), photosensitization aid (D), and additive component (E) may be added without a solvent when preparing the first active energy ray-curable composition, or may be added directly after diluting with a solvent. The above-mentioned numerical ranges of the contents are all numerical ranges based on the solid content.

[0081] (viscosity) The viscosity of the first active energy ray-curable composition may be any viscosity that allows application by various methods, but its viscosity at 25°C may be, for example, 200 mPa·s or less, preferably 10 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.

[0082] (Curing method) The first active energy ray-curable composition can be used in the form of an electron beam curable type or an 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.

[0083] In the electron beam curing type, any suitable electron beam irradiation conditions can be adopted as long as they are conditions capable of curing the first active energy ray-curable 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 preferably 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 may not be cured sufficiently. If the exposure dose is more than 100 kGy, the optical layer may be damaged, resulting in reduced mechanical strength and yellowing, and the desired optical properties may not be obtained.

[0084] 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.

[0085] In the ultraviolet curing type, the light irradiation intensity of the first active energy ray curable 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 radiation 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 photocationic polymerization initiator (B), photosensitizer (C), and sensitization aid (D), 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 required cumulative light amount in 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.) varies depending on the combination of the types of the first retardation layer 13 and the second retardation layer 30 and the adhesive type.

[0086] The light source used to polymerize and cure the first active energy ray-curable composition by irradiation with active energy rays in the present invention is not particularly limited, and examples thereof include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, 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.

[0087] The first active energy ray-curable composition preferably satisfies the following formula (1) from the viewpoint of durability and adhesion. (J A / J B )×100≧60(%) (1) [In the formula, J A represents the amount of heat (unit: mJ / g) measured by a differential scanning calorimeter when the first active energy ray-curable composition is irradiated with ultraviolet light having a peak at a wavelength of 365 nm through a substrate having 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, J B represents the amount of heat (unit: mJ / g) measured by a differential scanning calorimeter when the first active energy ray-curable composition is irradiated with ultraviolet light having a peak at a wavelength of 365 nm without passing through a substrate.] Heat amount J A and J B can be measured according to the method described in the Examples section below.

[0088] By using the first active energy ray-curable composition satisfying formula (1), good water resistance and adhesion tend to be easily obtained. In addition, it becomes possible to cure the active energy ray-curable composition by irradiating it with active energy rays from the side of a retardation layer having low ultraviolet transmittance or the polarizing film 11, which has been difficult to achieve in the past.

[0089] The left side of formula (1) is 70% or more, more preferably 80% or more. The left side of formula (1) is usually 100% or less, for example, less than 100%, 90% or less.

[0090] The storage modulus of the first cured material layer 12 at 80°C may be, for example, 300 MPa or more, and from the viewpoint of preventing cracks from occurring during processing, it is preferably 500 MPa or more, more preferably 900 MPa or more, and even more preferably 1000 MPa or more. The storage modulus at 80°C can be measured according to the measurement method described in the Examples section below.

[0091] (1st retardation layer) The first retardation layer 13 is not particularly limited as long as it includes at least one retardation 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 normal dispersion or a retardation layer with reverse wavelength dispersion. As long as the first retardation layer 13 includes at least one retardation layer, it may consist of only a retardation layer, or may include other layers in addition to the retardation layer. Examples of other layers include a substrate layer, an alignment film layer, and a protective layer. Note that the other layers do not affect the retardation value.

[0092] Examples of the retardation-exhibiting 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. The first retardation layer 13 preferably contains a liquid crystal layer capable of exhibiting retardation. When the first retardation layer 13 contains a liquid crystal layer, the surface of the first retardation layer 13 opposite to the first cured product layer 12 is preferably a liquid crystal layer capable of exhibiting retardation. A retardation-exhibiting layer that is a liquid crystal layer is generally easier to make thinner than a retardation-exhibiting layer that is a stretched film.

[0093] The first retardation layer 13 may have a light transmittance of 0% to 50% (preferably 0% to 10%) at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm. The light transmittance can be measured according to the measurement method described in the Examples section below. The first retardation layer 13 may have a light transmittance of 0% to 5% at a wavelength of 380 nm and a light transmittance of 10% or more at a wavelength of 400 nm.

[0094] When the first retardation layer 13 is made of only a retardation-exhibiting layer, the thickness is 0.5 μm or more and 10 μm or less, and preferably 0.5 μm or more and 5 μm or less. When the first retardation layer 13 includes layers other than the retardation-exhibiting layer (such as a substrate layer, an alignment film layer, and a protective layer), the total thickness is 0.5 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less.

[0095] 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.

[0096] 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.

[0097] 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).

[0098] 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.

[0099] 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.

[0100] 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 (b): Re(450)≦Re(550)≦Re(650) (b) Here, Re(λ) represents the in-plane retardation value for light with a wavelength of λ nm.

[0101] The optical properties of the first retardation layer 13 can be adjusted by the alignment state of the liquid crystal compound constituting the retardation-exhibiting layer or the stretching method of the stretched film constituting the retardation-exhibiting layer.

[0102] (1) 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 retardation layer and other layers. As shown in FIG. 2, the retardation layer 30 is formed by laminating a substrate layer 31, an alignment layer 32, and a liquid crystal retardation layer 33 in this order. The retardation layer is not limited to the retardation layer 30 shown in FIG. 2 as long as it includes the liquid crystal retardation layer 33. The retardation layer may be formed by peeling the substrate layer 31 from the retardation layer 30 and only comprising the alignment layer 32 and the retardation layer 33, or by peeling the substrate layer 31 and the alignment layer 32 from the retardation layer 30 and only comprising the liquid crystal retardation layer 33. From the viewpoint of thinning, the retardation layer is preferably formed by peeling the substrate layer 31, and more preferably by only comprising the liquid crystal retardation layer 33. The substrate layer 31 functions as a support layer that supports the alignment layer 32 and the liquid crystal retardation layer 33 formed on the substrate layer 31. The base layer 31 is preferably a film made of a resin material.

[0103] 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."

[0104] 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.

[0105] 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.

[0106] The thickness of the base layer 31 is not particularly limited, but it is preferable that the base layer 31 is not included so that the total thickness of the first retardation layer 13 is 10 μm or less.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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).

[0115] (2) Retardation layer having a stretched film as a 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.

[0116] 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.

[0117] 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.

[0118] 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.).

[0119] Polymethacrylic acid esters and polyacrylic acid esters (hereinafter, polymethacrylic acid esters and polyacrylic acid esters may be collectively referred to as (meth)acrylic resins) are readily available on the market.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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].

[0124] 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.

[0125] (Other layers) The laminate 100 may further include other layers in addition to the polarizing film 11, the first cured material layer 12, and the first retardation layer 13. The other layers will be described with reference to FIG. 3. As shown in FIG. 3, the laminate 100 may include a second cured material layer 14 and a second retardation layer 15 laminated in this order on the side of the first retardation layer 13 opposite to the first cured material layer 12. Furthermore, the laminate 100 may include a thermoplastic resin film 16 laminated via an adhesive layer 17 on the side of the polarizer 11 opposite to the first cured material layer 12. Furthermore, the laminate 100 may include a pressure-sensitive adhesive layer 18 on the side of the second retardation layer 15.

[0126] (Second cured material layer) The second cured material layer 14 is disposed between the first retardation layer 13 and the second retardation layer 15, and bonds the first retardation layer 13 and the second retardation layer 15. The second cured material layer 14 contains a cured product of the second active energy ray-curable composition.

[0127] The second active energy ray-curable composition may be any composition that can be cured by irradiation with active energy rays, and may be, for example, a cationically polymerizable adhesive composition or a radically polymerizable adhesive composition. The second active energy ray-curable composition may contain neither a photosensitizer nor a photosensitizing aid. Examples and preferred ranges of the cationically polymerizable adhesive composition are the same as those described for the first active energy ray-curable composition.

[0128] The thickness of the second cured material layer 14 may be, for example, 20 μm or less, preferably 10 μm or less, more preferably 6 μm or less, and even more preferably 5 μm or less. The thickness of the second cured material layer 14 may be, for example, 0.5 μm or more, and preferably 1 μm or more.

[0129] (Second retardation layer) The second retardation layer 15 is not particularly limited as long as it is a retardation layer including at least one retardation-exhibiting layer that imparts a predetermined retardation to light. The examples and preferred ranges of the second retardation layer 15 are the same as those of the first retardation layer 13. Hereinafter, a laminate in which the second retardation layer 15 and the first retardation layer 13 are bonded via the second cured product layer 14 is also referred to as a retardation layer laminate.

[0130] The second retardation layer 15 preferably includes a liquid crystal layer capable of expressing retardation. When the second retardation layer includes a liquid crystal layer, the surface of the second retardation layer 15 on the side of the second cured product layer 14 is preferably a liquid crystal layer capable of expressing retardation. When the laminate includes a first retardation layer and a second retardation layer, at least one of the first retardation layer and the second retardation layer preferably includes a liquid crystal layer capable of expressing retardation.

[0131] The second retardation layer 15 can have a light transmittance of 0% to 90% at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm. The second retardation layer 15 may have a light transmittance of 0% to 80% at a wavelength of 380 nm and a light transmittance of 50% or more at a wavelength of 400 nm. When the laminate includes a first retardation layer and a second retardation layer, at least one of the first retardation layer and the second retardation layer 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.

[0132] The thickness of the second retardation layer 15 is preferably 0.5 μm or more and 50 μm or less, and more preferably 0.5 μm or more and 5 μm or less.

[0133] Examples of the combination of the first retardation layer 13 and the second retardation layer 15 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.

[0134] In the case of i), it is preferable that the first retardation layer 13 is a half wavelength layer and the second retardation layer 15 is a quarter wavelength layer.

[0135] In the case of ii), it is preferable that the first retardation layer 13 is a half-wave layer and the second retardation layer 15 is an optical compensation layer, and it is more preferable that the first retardation layer 13 is a half-wave layer and the second retardation layer 15 is a positive C plate.

[0136] In the case of iii), it is preferable that the first retardation layer 13 is a quarter-wave layer and the second retardation layer 15 is an optical compensation layer, and it is more preferable that the first retardation layer 13 is a quarter-wave layer and the second retardation layer 15 is a positive C plate.

[0137] (thermoplastic resin film) The thermoplastic resin film 16 can be disposed on the viewing side of the laminate. The thermoplastic resin film 16 can function as a protective film for protecting the polarizing film 11. A laminate in which the polarizing film 11 and the thermoplastic resin film 16 are laminated via the adhesive layer 17 is also called a linear polarizing plate. Although not shown, the thermoplastic resin films may be disposed on both sides of the polarizer. The thermoplastic resin film is preferably disposed on one side of the polarizer, and is preferably disposed only on the viewing side of the laminate from the viewpoint of thinning.

[0138] The material of the thermoplastic resin film 16 is not particularly limited, but examples 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 16 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 10 μm or more. Furthermore, the thermoplastic resin film 16 may or may not have a retardation.

[0139] The thermoplastic resin film 16 may contain one or more additives such as rubber particles, lubricants, fluorescent whitening agents, dispersants, heat stabilizers, light stabilizers, ultraviolet absorbers, infrared absorbers, antistatic agents, and antioxidants, as needed.

[0140] (adhesive layer) The adhesive layer 17 can be disposed to bond the thermoplastic resin film 16 and the polarizing film 11. The adhesive layer 17 preferably contains a cured product of an aqueous adhesive composition. The aqueous adhesive composition can be, for example, a composition that uses a polyvinyl alcohol resin or a urethane resin as a main component and contains a crosslinking agent or a curing compound such as an isocyanate compound or an epoxy compound to improve adhesion.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] The water-based adhesive composition may contain an ultraviolet absorber, a filler, a flow control agent, an antifoaming agent, a leveling agent, a pigment, an organic solvent, and the like.

[0145] 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.

[0146] The aqueous adhesive composition can be applied to one or both sides of a polarizer or a thermoplastic resin film, and then the two films are bonded together. The water is evaporated by heating, and the thermal crosslinking reaction is allowed to proceed, thereby sufficiently bonding the two films together.

[0147] The thickness of the adhesive layer 17 may be, for example, 20 μm or less, preferably 10 μm or less, and more preferably 5 μm or less. The thickness of the adhesive layer 17 may be, for example, 0.1 μm or more.

[0148] (Adhesive layer) The laminate 100 may have a pressure-sensitive adhesive layer 18 on the second retardation layer 15 side. The pressure-sensitive adhesive layer 18 can be composed of a pressure-sensitive adhesive composition containing a resin such as a (meth)acrylic, rubber, urethane, ester, silicone, or polyvinyl ether resin as a main component. Among these, a pressure-sensitive adhesive composition having a (meth)acrylic resin as a base polymer, 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 18 is usually 3 μm or more and 30 μm or less, and preferably 3 μm or more and 25 μm or less.

[0149] 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.

[0150] 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.

[0151] (Method of manufacturing laminate) An example of a method for producing a laminate of the present invention will be described with reference to Fig. 4. As shown in Fig. 4(A), a linear polarizing plate 10 is produced by laminating a polarizing film 11 and a thermoplastic resin film 16 via an adhesive layer 17. As shown in Fig. 4(B), a first retardation layer 13 including a first retardation layer 21, a first alignment layer 22, and a first base layer 23, and a second retardation layer 15 including a second retardation layer 26, a second alignment layer 25, and a second base layer 24 are prepared. As shown in Fig. 4(C), the first retardation layer 13 and the second retardation layer 15 are laminated via a second cured material layer 14 to produce a retardation layer laminate 50 in which the first base layer 23, the first alignment layer 22, the first retardation layer 21, the second cured material layer 14, the second retardation layer 26, the second alignment layer 25, and the second base layer 24 are laminated in this order. As shown in FIG. 4(D), the polarizing film 11 side of the linear polarizing plate 10 and the first retardation layer 13 side of the retardation layer laminate 50 are laminated via the first cured product layer 12 to obtain a laminate 70.

[0152] As a method for bonding the polarizing film 11 and the thermoplastic resin film 16, an aqueous adhesive composition may be applied to either or both of the bonding surfaces of the polarizing film 11 and the thermoplastic resin film 16, and the other bonding surface is then laminated thereon, followed by curing the aqueous adhesive composition that constitutes the adhesive layer 17.

[0153] Examples of a method for bonding the first retardation layer 13 and the second retardation layer 15 include a method in which an active energy ray-curable composition is applied to either or both of the bonding surface of the first retardation layer 13 and the bonding surface of the second retardation layer 15, the other bonding surface is laminated thereon, and the active energy ray-curable adhesive constituting the second cured material layer 14 is cured. The active energy rays for curing the second cured material layer 14 can be irradiated from either or both of the first retardation layer 13 and the second retardation layer 15.

[0154] Examples of a method for bonding the linear polarizer 10 and the retardation layer laminate 50 include a method in which an active energy ray-curable 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 50, the other bonding surface is laminated thereon, and the active energy ray-curable adhesive constituting the first cured material layer 12 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 50. The active energy rays for curing the first cured material layer 12 can be applied from either or both of the linear polarizer 10 and the retardation layer laminate 50.

[0155] 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 on the surface. The aqueous adhesive composition and the active energy ray-curable 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.

[0156] The laminate of the present invention may be a laminate as shown in Fig. 4(D), or may be a laminate obtained by peeling off at least one of the first base layer 23 and the second base layer 24. The laminate may also be a laminate obtained by peeling off the first base layer 23 and the first alignment layer 22 from the laminate shown in Fig. 4(D), or a laminate obtained by peeling off the second base layer 24 and the second alignment layer 25 from the laminate shown in Fig. 4(D).

[0157] (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.

[0158] The laminate can function as a circular polarizer or an antireflection film. The laminate can be placed 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]

[0159] 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.

[0160] (viscosity measurement) The active energy ray-curable composition was adjusted to a temperature of 25° C. using an E-type viscometer ("TVE-25" manufactured by Toki Sangyo Co., Ltd.), and then the viscosity was measured at 10 rpm.

[0161] (Calorie measurement) The active energy ray-curable adhesive composition was placed in a differential scanning calorimeter, and the active energy ray-curable adhesive composition was irradiated with ultraviolet light having a peak at a wavelength of 365 nm. B The amount of heat (unit: mJ / g) was measured. The active energy ray-curable adhesive composition was irradiated with ultraviolet light having a peak at a wavelength of 365 nm through a substrate having 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. A (unit: mJ / g) was measured.

[0162] (Light transmittance measurement) The λ / 4 retardation layer and the positive C plate were cut into a size of 30 mm × 30 mm, and the transmittance was measured in the wavelength range of 200 to 510 nm using a UV-visible spectrophotometer "UV-2450" manufactured by Shimadzu Corporation.

[0163] (Measurement of storage modulus at 80°C) The prepared active energy ray-curable composition was coated on one side of a polyethylene terephthalate film (product name "Toyobo Ester Film E7002", manufactured by Toyobo Co., Ltd.) using a coating machine (bar coater, manufactured by Daiichi Rika Co., Ltd.) so that the film thickness after curing would be approximately 10 μm. Next, a "D bulb" manufactured by Fusion UV Systems Inc. was used to apply the coating with an integrated light dose of 1,000 mJ / cm. 2 The adhesive was cured by irradiating it with ultraviolet light so that the adhesive became uniform. This was cut into a size of 5 mm x 30 mm, and the polyethylene terephthalate film was peeled off to obtain a cured film of the adhesive. The cured film thus obtained was gripped with the 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, and the storage modulus at a temperature of 80°C was determined by setting the tensile and contraction frequency to 1 Hz and the heating rate to 3°C / min.

[0164] (Adhesion measurement) An acrylic adhesive (film thickness: 25 μm) was attached to the positive C-plate side of the laminate produced in the examples and comparative examples, and after cutting to a size of 200 mm long x 25 mm wide, the adhesive layer surface was attached to a soda glass substrate. Next, a cutter blade was inserted between the polarizer and the λ / 4 retardation layer, and the film was peeled off 30 mm from the edge in the longitudinal direction. The peeled portion was then gripped with the gripping part 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 an atmosphere of 23°C and 55% relative humidity, in accordance with JIS K 6854-2:1999 "Adhesives - Peel Adhesion Strength Test Method - Part 2: 180° Peel." The average peel strength over a 170 mm length, excluding the 30 mm around the gripping part, was determined and evaluated according to the following criteria. The results are shown in Table 1. 〇: 180° peel force is 0.5N or more ×: 180° peel force is less than 0.5N

[0165] (Durability evaluation) The laminates prepared in the examples and comparative examples were cut into pieces measuring 30 mm x 30 mm, and subjected to a moist heat test in which they were left in a moist heat environment at a temperature of 80°C and a relative humidity of 90% for 24 hours. The polarization degree and retardation value were measured before and after the test, and the absolute value of the difference was calculated. Evaluation was performed according to the following criteria. Polarization standard: ◎: 1.0 or less 〇: More than 1.0 but less than 3.0 ×: More than 3.0 In-plane retardation value criteria: ◎: 0.5 or less 〇: More than 0.5 but less than 1.0 ×: over 1.0 To measure the degree of polarization, a Shimadzu UV-2450 ultraviolet-visible spectrophotometer equipped with an optional accessory, a film holder with polarizer, was used to measure the transmission spectra in the transmission axis direction and absorption axis direction of the polarizer in the wavelength range of 380 nm to 780 nm, and the degree of polarization was calculated using the UV-Probe software that came with the spectrophotometer. The in-plane retardation value was measured using a phase difference measuring device "KOBRA-WR" manufactured by Oji Scientific Instruments Co., Ltd., and the in-plane retardation value R e I asked. The in-plane retardation value Re is calculated by the following formula: R e =(n x -n y )×d (The refractive index in the in-plane slow axis direction (the direction in the plane where the refractive index is maximum) is n x , the refractive index in the in-plane fast axis direction (the direction perpendicular to the in-plane slow axis direction) is n y , where d is the thickness of the laminate.

[0166] (Preparation of First Active Energy Ray-Curable 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 first active energy ray-curable compositions (adhesives 1 to 13). The cationic polymerization initiator (B-1) was blended as a 50% propylene carbonate solution, and the solid content is shown in Table 1. The viscosity measurement results and calorimetry results are shown in Table 2.

[0167] [Table 1]

[0168] (Cationically polymerizable compound (A)) A-1: 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane (trade name: OXT-221, manufactured by Toagosei Co., Ltd., viscosity 0.012 Pa s (temperature 25°C), refractive index 1.45 (wavelength 589 nm)) A-2: 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Corporation, viscosity 0.25 Pa·s (temperature 25°C), refractive index 1.50 (wavelength 589 nm)) A-3: 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (trade name: EHPE3150, manufactured by Daicel Corporation, viscosity greater than 30 Pa·s (temperature 25°C), refractive index 1.54 (wavelength 589 nm)) A-4: Neopentyl glycol diglycidyl ether (trade name: EX-211L, manufactured by Nagase ChemteX Corporation, viscosity 0.02 Pa·s (temperature 25°C), refractive index 1.45 (wavelength 589 nm)) A-5: 2-Ethylhexyl glycidyl ether (trade name: EX-121, manufactured by Nagase ChemteX Corporation, viscosity 0.004 Pa·s (temperature 25°C), refractive index 1.43 (wavelength 589 nm)) A-6: Bisphenol A epoxy resin (trade name: jER828, manufactured by Mitsubishi Chemical Corporation, viscosity 13 Pa·s (temperature 25°C), refractive index 1.57 (wavelength 589 nm)) A-7: Xylylene bisoxetane (product name: OXT-121, manufactured by Toagosei, viscosity 0.15 Pa·s (temperature 25°C), refractive index 1.51 (wavelength 589 nm))

[0169] (Photocationic Polymerization Initiator (B)) B-1: CPI-100P (San-Apro Co., Ltd., 50% by weight solution)

[0170] (Photosensitizer (C)) C-1: 9,10-dibutoxyanthracene

[0171] (Photosensitizing Coagent (D)) D-1: 1,4-diethoxynaphthalene

[0172] [Table 2]

[0173] (Second active energy ray-curable composition) A second active energy ray-curable composition was prepared by mixing 70 parts by mass of 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Corporation), 20 parts by mass of neopentyl glycol diglycidyl ether (trade name: EX-211L, manufactured by Nagase ChemteX Corporation), 10 parts by mass of 2-ethylhexyl glycidyl ether (trade name: EX-121, manufactured by Nagase ChemteX Corporation), 2.25 parts by mass (solid content) of a cationic polymerization initiator (trade name: CPI-100P, manufactured by San-Apro Co., Ltd.), and 2 parts by mass of 1,4-diethoxynaphthalene, followed by degassing.

[0174] (Acrylic adhesive sheet A) (1) Preparation of materials The following acrylic base polymer (H-1), isocyanate crosslinking agent (H-2), and silane coupling agent (H-3) were prepared. (H-1) Copolymer of butyl acrylate, methyl acrylate, acrylic acid and hydroxyethyl acrylate (H-2) Ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate (solids concentration 75%) ("Coronate L" (trade name), manufactured by Tosoh Corporation) (H-3) 3-Glycidoxypropyltrimethoxysilane, liquid ("KBM-403" (trade name), manufactured by Shin-Etsu Chemical Co., Ltd.)

[0175] (2) Preparation of Adhesive 1 100 parts by mass of the acrylic base polymer (H-1), 0.2 parts by mass of an isocyanate-based crosslinking agent (H-2), and 0.2 parts by mass of a silane coupling agent (H-3) were mixed, thoroughly stirred, and diluted with ethyl acetate to prepare adhesive 1.

[0176] (3) Preparation of acrylic adhesive sheet A The pressure-sensitive adhesive 1 prepared above was coated onto a release paper and heat-treated at 90°C for 1 minute to obtain an acrylic pressure-sensitive adhesive sheet A. The resulting pressure-sensitive adhesive layer was peeled off from the release paper and its thickness was measured to be 5µm. The thickness of the pressure-sensitive adhesive layer was measured using a contact film thickness meter (Nikon Corporation, trade name "DIGIMICRO MH-15M").

[0177] (Acrylic adhesive sheet B) The adhesive 1 used in producing the acrylic adhesive sheet A was coated on a release paper so that the adhesive layer had a thickness of 25 μm, and then heated at 90° C. for 1 minute to obtain an acrylic adhesive sheet B.

[0178] (Preparation of linear polarizer) A 20 μm thick polyvinyl alcohol film with a degree of polymerization of 2,400 and a saponification degree of 99.9% or greater was uniaxially stretched to a stretch ratio of 4.5x on a roll heated to 125°C. While maintaining tension, the film was immersed in water at 28°C for 30 seconds, followed by a 30-second dye bath at 28°C containing 0.05 parts by weight of iodine and 5 parts by weight of potassium iodide per 100 parts by weight of water. The film was then immersed for 110 seconds in a 64°C boric acid aqueous solution 1 containing 5.5 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water. The film was then immersed for 30 seconds in a 67°C boric acid aqueous solution 2 containing 5.5 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water. The film was then rinsed with 10°C pure water and dried at 80°C to obtain a polarized film. The resulting polarized film had a thickness of 7 μm.

[0179] Furthermore, a 25 μm-thick cycloolefin film (COP film) with a hard coat layer was attached to one side of the obtained polarizing film opposite the hard coat layer via an aqueous adhesive (thickness: 0.1 μm), and the resulting film was dried at 90°C to obtain a linear polarizing plate 1 having a laminated structure of COP film / aqueous adhesive (adhesive layer) / polarizer. The aqueous adhesive was prepared by adding 3 parts of acetoacetyl-modified polyvinyl alcohol (Z-200, manufactured by Nippon Synthetic Chemicals) and 1.5 parts of water-soluble polyamide epoxy resin (Sumirez Resin 650, manufactured by Sumika Chemtex, an aqueous solution with a solids concentration of 30%) to 100 parts of water.

[0180] (Production of λ / 4 retardation layer) A coating solution containing a rod-shaped polymerizable nematic liquid crystal monomer was applied to a λ / 4 alignment transparent resin substrate with an alignment film laminated thereon, and solidified while maintaining the refractive index anisotropy, to obtain a 1 μm-thick retardation layer on the transparent resin substrate. The obtained λ / 4 retardation layer had a light transmittance of 0% at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm.

[0181] (Manufacturing positive C plates) A composition for forming a vertical alignment film was applied to one side of the substrate film to a thickness of 3 μm, and 200 mJ / cm 2 A vertical alignment film was produced by irradiating the vertical alignment layer with ultraviolet light. A composition for forming a positive C plate was applied onto the vertical alignment layer and dried, and then the coating was irradiated with ultraviolet light (UV) to polymerize the polymerizable liquid crystal compound, thereby obtaining a positive C plate. The obtained positive C plate had a light transmittance of 80% at a wavelength of 380 nm and a light transmittance of 90% or more at a wavelength of 400 nm.

[0182] (Production of retardation layer laminate) The λ / 4 retardation layer and the liquid crystal layer side of the positive C plate were subjected to corona treatment. The liquid crystal layers were bonded together using a laminator using a second active energy ray-curable composition so that the thickness of the cured layer was 2 μm, thereby obtaining a laminate. The obtained laminate was irradiated from the positive C-plate side with an ultraviolet irradiation device (manufactured by Fusion UV Systems Co., Ltd.) at an accumulated light dose of 400 mJ / cm 2 The second active energy ray-curable composition was cured by ultraviolet irradiation with UV-A to form a second cured material layer, thereby obtaining a retardation layer laminate having a laminated structure of "λ / 4 retardation layer" (first retardation layer) / adhesive layer (second cured material layer) / "positive C plate" (second retardation layer).

[0183] Example 1 The alignment film and transparent resin substrate on the λ / 4 retardation layer side of the obtained retardation layer laminate were peeled off, and the surface of the linear polarizer opposite to the thermoplastic resin film was attached to the liquid crystal layer of the λ / 4 retardation layer using adhesive 1. The thickness of the first cured product layer made of adhesive 1 was 2 μm, and the angle formed between the transmission axis of the polarizer and the slow axis of the λ / 4 retardation layer was 45°. Next, the alignment film and transparent resin substrate on the positive C plate side were peeled off to obtain a laminate of Example 1 having a laminate structure of COP film (thermoplastic resin film) / water-based adhesive (adhesive layer) / polarizer / first cured product layer (cured product layer of adhesive 1) / "λ / 4 retardation layer" (first retardation layer) / second cured product layer (cured product layer of second active energy ray-curable composition) / "positive C plate" (second retardation layer). The evaluation results of storage modulus, adhesion, and durability at 80°C are shown in Table 3.

[0184] <Examples 2 to 10 and Comparative Examples 1 to 3> Laminates of Examples 2 to 11 and Comparative Examples 1 to 3 were produced in the same manner as in Example 1, except that adhesives 2 to 10 and adhesives 11 to 13 were used instead of adhesive 1. The results are shown in Table 3.

[0185] <Comparative Example 4> An acrylic pressure-sensitive adhesive sheet A with an adhesive layer thickness of 5 μm was attached to the surface of the linear polarizer opposite to the thermoplastic resin film to form an acrylic pressure-sensitive adhesive layer A. The alignment film and transparent resin substrate on the λ / 4 retardation layer side of the retardation layer laminate were peeled off. The liquid crystal layer of the λ / 4 retardation layer of the retardation layer laminate was attached to the acrylic pressure-sensitive adhesive layer A of the linear polarizer. The angle formed by the transmission axis of the polarizer and the slow axis of the λ / 4 retardation layer was 45°. Next, the alignment film and transparent resin substrate on the positive C plate side were peeled off to obtain a laminate of Comparative Example 1 having a laminate structure of COP film (thermoplastic resin film) / water-based adhesive (adhesive layer) / polarizer / acrylic pressure-sensitive adhesive layer A / "λ / 4 retardation layer" (first retardation layer) / second cured product layer (cured product layer of second active energy ray-curable composition) / "positive C plate" (second retardation layer). The water resistance of the obtained laminate was evaluated. The results are shown in Table 3.

[0186] <Comparative Example 5> A laminate of Comparative Example 5 was obtained in the same manner as in Comparative Example 4, except that an acrylic pressure-sensitive adhesive layer B having a thickness of 25 μm was formed using an acrylic pressure-sensitive adhesive sheet B instead of forming an acrylic pressure-sensitive adhesive layer A having a thickness of 5 μm using an acrylic pressure-sensitive adhesive sheet A in Comparative Example 4. The results are shown in Table 3.

[0187] [Table 3] [Explanation of symbols]

[0188] 10 Linear polarizing plate, 11 Polarizing film, 12 First cured product layer, 13 First retardation layer, 14 Second cured product layer, 15 Second retardation layer, 16 Thermoplastic resin film, 17 Adhesive layer, 18 Pressure-sensitive adhesive layer, 20 First retardation layer, 21 Base layer, 22 Alignment layer, 23 Retardation layer, 24 Base layer, 25 Alignment layer, 26 Retardation layer, 30 Retardation layer, 31 Base layer, 32 Alignment layer, 33 Retardation layer, 50 Retardation layer laminate, 70 Laminate, 100 Laminate

Claims

1. A laminate in which a polarizing film, a first cured material layer, and a first retardation layer are laminated in this order, wherein the thickness of the first retardation layer is 10 μm or less, the first cured material layer contains a cured product of a first active energy ray-curable composition, and the first active energy ray-curable composition is Contains a cationically polymerizable compound (A) and a photocationic polymerization initiator (B), the photocationic polymerization initiator (B) is contained in an amount of 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the cationically polymerizable compound (A), the cationically polymerizable compound (A) contains, based on the total mass of the cationically polymerizable compound (A), 45% by mass or more and 90% by mass or less of an oxetane compound, 10 parts by mass or more and 50 parts by mass or less of an alicyclic epoxy compound, 30 parts by mass or less of an aliphatic epoxy compound, and 40 parts by mass or less of an aromatic epoxy compound; The first active energy ray-curable composition is a photosensitizer (C) that exhibits maximum absorption at wavelengths longer than 400 nm, in an amount of 0.1 parts by mass or more and 3.0 parts by mass or less per 100 parts by mass of the cationically polymerizable compound (A); Contains The photosensitizer (C) is represented by the following general formula (I): 【Chemical 1】]] (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, R ３ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) A laminate comprising an anthracene-based compound represented by the formula:

2. 2. The laminate according to claim 1, wherein the oxetane compound is at least one selected from the group consisting of 3-ethyl-3-hydroxymethyloxetane, xylylenebisoxetane, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, and 3-ethyl-3-(cyclohexyloxymethyl)oxetane.

3. The laminate according to claim 1 or 2, wherein the cationically polymerizable compound (A) contains an alicyclic epoxy compound in an amount of 10% by mass or more and 50% by mass or less based on the total mass of the cationically polymerizable compound (A).

4. The laminate according to any one of claims 1 to 3, wherein the photocationic polymerization initiator (B) is at least one ionic compound selected from the group consisting of aromatic sulfonium salts and aromatic iodonium salts.

5. The laminate according to any one of claims 1 to 4, wherein the first active energy ray-curable composition has a viscosity at 25°C of 200 mPa·s or less.

6. The laminate according to any one of claims 1 to 5, wherein the first cured material layer has a storage modulus at 80°C of 300 MPa or more.

7. The laminate according to any one of claims 1 to 6, wherein the first cured material layer has a thickness of 0.5 µm or more and 10 µm or less.

8. The first retardation layer has a light transmittance of 0% or more and 50% or less at a wavelength of 380 nm, and a light transmittance of 30% or more at a wavelength of 400 nm. The laminate according to any one of claims 1 to 7.

9. The first retardation layer 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. The laminate according to any one of claims 1 to 8.

10. a second cured material layer and a second retardation layer are laminated in this order on the opposite side of the first cured material layer of the first retardation layer, The second cured product layer contains a cured product of a second active energy ray-curable composition, and at least one of the first retardation layer and the second retardation layer has a light transmittance at a wavelength of 380 nm of 0% or more and 10% or less, and a light transmittance at a wavelength of 400 nm of 30% or more. The laminate according to any one of claims 1 to 9.

11. The laminate according to claim 10 , wherein the first retardation layer is a half-wave retardation layer and the second retardation layer is a quarter-wave retardation layer.

12. The laminate according to claim 10 , wherein the first retardation layer is a half-wave retardation layer or a quarter-wave retardation layer, and the second retardation layer is a positive C-plate.

13. The laminate according to any one of claims 10 to 12, wherein at least one of the first retardation layer and the second retardation layer includes a liquid crystal layer capable of generating retardation.

14. The laminate according to any one of claims 10 to 13, wherein at least one of the first retardation layer and the second retardation layer has a thickness of 0.5 µm or more and 50 µm or less.

15. A circularly polarizing plate comprising the laminate according to any one of claims 1 to 14.

16. An image display device comprising: an image display panel; and the laminate according to any one of claims 1 to 14, disposed on a viewing side of the image display panel.

17. The image display device according to claim 16 , wherein the laminate is oriented so that the polarizing film is on the viewing side.

18. An organic electroluminescence display device comprising the image display device according to claim 16 or 17.

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