TW202043819A - Laminate and image display device - Google Patents

Abstract

The purpose of this invention is to provide: a flexible laminate comprising a front surface sheet and a circular polarizing plate with an adhesive layer on both sides thereof, wherein even if left for a long period of time in a flexed state under a high temperature, high humidity environment with the front surface sheet on the inside, the waves which occur on the surface on the front surface sheet side in the bent portion is small, providing a laminate with excellent visibility; and an image display device equipped with said laminate. This invention provides a laminate comprising a front surface sheet and a circular polarizing plate with adhesive layer on both sides, wherein if the thickness of the front surface sheet is defined as a [[mu]m], the thickness of the circular polarizing plate with adhesive layer on both sides is defined as b [[mu]m], and the moisture and heat-resistant modulus of elasticity at a front surface sheet temperature of 60 DEG C and a relative humidity of 90%RH is defined as c[MPa], the condition [(b/a)*c] ≥ 2200 is satisfied.

Description

Laminated body and image display device

The present invention relates to a laminated body and an image display device including the laminated body.

Patent Document 1 proposes that in an image display device having an image display panel, an adhesive layer, and a flexible film in this order, the adhesive layer is arranged separately from the image display panel in the curved area. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Korean Published Patent 10-2016-0069560

[The problem to be solved by the invention] A laminated body including a front surface plate and a circular polarizing plate with adhesive layers on both sides is placed in a high temperature and high humidity environment in a curved state, and when released from the curved state, the curved portion may fluctuate. Such undulations sometimes reduce the smoothness of the surface. If the smoothness of the surface decreases, for example, the reflected image will be distorted and visibility will decrease. The object of the present invention is to provide a laminate and an image display device including the laminate, the laminate being a bendable laminate having a front surface plate and a circular polarizing plate having adhesive layers on both sides, wherein After the front panel side is the inner side and is left for a long time in a curved state under a high temperature and high humidity environment, the curved part has small undulations on the surface of the front panel side, and the visibility is excellent. [Means to solve the problem]

The present invention provides the following laminate and image display device. [1] A laminated body comprising a front surface plate and a circular polarizing plate with adhesive layers on both sides, and when the thickness of the front surface plate is a [μm], the circle with adhesive layers on both sides When the thickness of the polarizing plate is set to b [μm], and the tensile elastic coefficient of the front surface plate at a temperature of 60°C and a relative humidity of 90% RH is set to c [MPa], the laminate satisfies the following formula ( 1): [(B/a)×c]≧2200 (1). [2] The layered body according to [1], wherein the a and the c satisfy the following formula (2): a/c≦0.03 (2). [3] The laminate according to [1] or [2], wherein the front surface plate has a hard coat layer. [4] The laminate according to any one of [1] to [3], wherein the circularly polarizing plate with adhesive layers on both sides includes a first adhesive layer, a linear polarizing plate, and a retardation layer in this order , And the second adhesive layer. [5] The laminate according to [4], wherein the linear polarizing plate includes a thermoplastic resin film having a hard coat layer on at least one surface. [6] An image display device including the laminated body according to any one of [1] to [5]. [Effects of the invention]

According to the present invention, it is possible to provide a laminate and an image display device including the laminate. The laminate is a bendable laminate having a front surface plate and a circularly polarizing plate having adhesive layers on both sides, wherein After the front panel side is the inner side and is left for a long time in a curved state under a high temperature and high humidity environment, the curved part has small undulations on the surface of the front panel side, and the visibility is excellent.

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 the following drawings, the scales are appropriately adjusted to make the components easy to understand, and the scales of the respective components shown in the drawings may not necessarily match the scales of the actual components.

＜Laminated body＞ Fig. 1 is a schematic cross-sectional view of a laminate according to an embodiment of the present invention. The laminated body 100 shown in FIG. 1 includes a front surface plate 10 and a circular polarizing plate 20 with adhesive layers on both surfaces.

The laminate 100 can be bent at least in the direction in which the front surface plate 10 is inside. Being able to bend means that it can be bent in a direction where the front surface plate 10 is inside without cracking.

When the thickness of the front surface plate 10 is set to a [μm], the thickness of the circular polarizing plate 20 with adhesive layers on both sides is set to b [μm], and the front surface plate 10 is set at a temperature of 60°C and a relative humidity of 90% When the coefficient of tensile elasticity in RH (hereinafter, sometimes referred to as the “tensile elastic coefficient”) is set to c [MPa], the layered body 100 satisfies the following formula (1). In this specification, unless otherwise specified, the coefficient of tensile elasticity means a value measured in an environment with a temperature of 60°C and a relative humidity of 90%RH. [(B/a)×c]≧2200 (1)

Since the laminated body 100 satisfies the formula (1), even after the front surface plate 10 is placed on the inner side and left for a long time in a high-temperature and high-humidity environment, it can be restrained from being bent on the front surface plate 10 side. The undulations produced on the surface can ensure uniform visibility. The front surface plate 10 and the circular polarizing plate 20 with adhesive layers on both sides are selected to satisfy the above formula (1). From the viewpoint of improving the surface undulation, the laminate 100 preferably satisfies the following formula (1a), and more preferably satisfies the following formula (1b): [(B/a)×c]≧3000 (1a) [(B/a)×c]≧4000 (1b). In addition, the laminated body 100 preferably satisfies the following formula (1c): [(B/a)×c]≦10000 (1c).

The inventors found that a laminate with a front surface plate and a circular polarizing plate with adhesive layers on both sides of the front surface plate as the inner side, and placed in a curved state for a long time in a high-temperature and high-humidity environment, sometimes the curved part The surface of the front panel side of the front panel has undulations, which cannot ensure uniform visibility. As a result of the research, it was found that the thickness of the front surface plate and the thickness of the circular polarization plate with the adhesive layer on both sides were adjusted so that the laminate of the front surface plate and the circular polarizing plate with adhesive layers on both sides satisfies the formula (1). , And the tensile elastic coefficient of the front surface plate, can suppress the above-mentioned fluctuations.

In this specification, the coefficient of tensile elasticity is measured by the method described in the column of Examples described later.

Regarding the laminate 100, from the viewpoint of suppressing undulations, it is preferable that a and c satisfy the following formula (2): a/c≦0.03 (2).

Regarding the laminate 100, from the viewpoint of suppressing undulations, it is more preferable to satisfy the following formula (2a): a/c≦0.02 (2a).

Regarding the laminate 100, from the viewpoint of suppressing undulation, it is preferable to satisfy the following formula (2b): a/c≧0.009 (2b).

The shape of the laminated body 100 in the plane direction may be, for example, a square shape, preferably a square shape having long sides and short sides, and more preferably a rectangular shape. When the shape of the laminate 100 in the plane direction is a rectangle, the length of the long side may be, for example, 10 mm or more and 1400 mm or less, and preferably 50 mm or more and 600 mm or less. The length of the short side is, for example, 5 mm or more and 800 mm or less, preferably 30 mm or more and 500 mm or less, and more preferably 50 mm or more and 300 mm or less. For each layer constituting the optical layered body 100, R processing may be performed on the corner portion, or the end portion may be cut or punched.

The thickness of the layered body 100 varies depending on the functions required of the layered body and the purpose of the layered body, and therefore is not particularly limited. For example, it is 20 μm or more and 500 μm or less, preferably 30 μm or more and 400 μm or less, and more preferably 50 μm or more and 300 μm or less.

The laminated body 100 can be used, for example, in a display device or the like. The display device is not particularly limited, and examples thereof include organic electroluminescence (EL) display devices, inorganic electroluminescence (inorganic EL) display devices, liquid crystal display devices, electroluminescence display devices, and the like. The laminated body 100 suppresses undulations after bending, so it is suitable for a flexible display.

[Front Panel] The front surface plate 10 may be a plate-shaped body capable of transmitting light. The front panel 10 may include only one layer, or may include two or more layers. As an example, a plate-shaped body made of resin (for example, a resin plate, a resin sheet, a resin film, etc.), a plate-shaped body made of glass (for example, a glass plate, a glass film, etc.), etc. are mentioned. The front surface plate may be the layer constituting the most surface of the display device.

From the viewpoints of suppressing the undulation after bending and reducing the thickness of the laminate, the thickness a [μm] of the front surface plate 10 may be, for example, 10 μm or more and 100 μm or less, preferably 20 μm or more and 85 μm or less, more preferably It is 30 μm or more and 70 μm or less. In the present invention, the thickness of each layer can be measured in accordance with the thickness measurement method described in the column of Examples described later.

The tensile elastic coefficient c [MPa] of the front surface plate 10 at a temperature of 60° C. and a relative humidity of 90% RH may be, for example, 1500 MPa or more, and from the viewpoint of suppressing undulations after bending, it is preferably 2000 MPa or more and 20000 MPa Below, it is more preferably 2000 MPa or more and 10000 MPa or less. The coefficient of tensile elasticity can be determined by, for example, the selection of the material or thickness of the plate-shaped body constituting the front surface plate, the composition of the hard coat-forming composition for forming the hard coat described later, or the selection of the thickness of the hardened product, and the The combination of these is adjusted to the above range.

When the front surface plate 10 is a plate-shaped body made of resin, the plate-shaped body made of resin is, for example, a resin film capable of transmitting light. As the thermoplastic resin constituting the resin plate-shaped body such as resin film, for example, chain polyolefin resin (polyethylene resin, polypropylene resin, polymethylpentene resin, etc.), cyclic polyolefin resin Polyolefin resins such as resins (norbornene resins, etc.); cellulose resins such as triacetyl cellulose; polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate Polyester resins such as esters; polycarbonate resins; ethylene-vinyl acetate resins; polystyrene resins; polyamide resins; polyether imine resins; polymethyl (meth)acrylate resins (Meth)acrylic resins; polyimide resins; polyether ether resins; polyvinyl chloride resins; polyvinyl chloride resins; polyvinylidene chloride resins; polyvinyl alcohol resins; polyethylene condensation Aldehyde resin; polyether ketone resin; polyether ether ketone resin; polyether ether resin; polyamide imine resin, etc. The thermoplastic resin can be used alone or in combination of two or more. Among them, as the thermoplastic resin constituting the front surface plate, cyclic polyolefin resins, polyimine resins, polyamide resins, and polyamide resins are preferred from the viewpoints of flexibility, strength, and transparency. The amide resin is more preferably a polyamide resin. As a specific example of the polyimide-based resin, the polyimide film described in JP 2018-119141 A and the like can be cited.

The front surface plate 10 may be a film provided with a hard coat layer on at least one surface of a base film. As the base film, a film made of the above-mentioned resin can be used. The hard coat layer can be formed on one side of the base film or on both sides. By providing a hard coat layer, a resin film with improved hardness and scratch resistance can be made.

The hard coat layer may include a hardened product of a hard coat layer forming composition (hereinafter also referred to as a HC (hard coat) layer forming composition) containing an active energy ray curable resin. Examples of ultraviolet curable resins include acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins. In order to increase the strength, the hard coat layer may contain additives. The additives are not limited, and include inorganic fine particles, organic fine particles, or a mixture of these. The composition for forming the HC layer can be prepared, for example, according to the method described in Korean Laid-open Patent 10-2018-0127050 and the like.

When the front surface plate 10 is a glass plate, it is preferable to use tempered glass for display as the glass plate. By using a glass plate, the front surface plate 10 having excellent mechanical strength and surface hardness can be constructed.

When the laminated body 100 is used in a display device, the front surface plate 10 not only has the function of protecting the front surface (screen) of the display device (functioning as a window film), but also has the function of being detected by the touch sensor panel 30 The touch control operation surface function, in addition, can also have blue light blocking function, viewing angle adjustment function, etc.

[Circular polarizing plate with adhesive layer on both sides] The circular polarizer 20 with adhesive layers on both sides preferably includes a first adhesive layer, a linear polarizer, a retardation layer, and a second adhesive layer in sequence. In this embodiment, the thickness of the circular polarizer 20 with adhesive layers on both sides can be from the surface of the first adhesive layer on the opposite side of the linear polarizer to the straight line in the second adhesive layer. The polarizing plate side is the distance between the surfaces on the opposite side. A circular polarizing plate in which the linear polarizing layer and the retardation layer are arranged such that the absorption axis of the linear polarizing plate and the retardation axis of the retardation layer are at a predetermined angle can exhibit an anti-reflection function. When the retardation layer includes a λ/4 plate, the angle formed by the absorption axis of the linear polarizer and the slow axis of the λ/4 plate may be 45°±10°. The linear polarizing plate and the retardation layer can be bonded by the bonding layer described later. Hereinafter, sometimes the first adhesive layer and the second adhesive layer are collectively referred to as an adhesive layer.

The thickness b of the circular polarizer 20 with adhesive layers on both sides may be, for example, 10 μm or more and 200 μm or less, preferably 15 μm or more and 150 μm or less, and more preferably 20 μm or more and 100 μm or less.

(Straight Polarizing Plate) Examples of linear polarizing plates include those comprising a stretched film or stretched layer on which a dichroic dye is adsorbed, or a film obtained by coating and curing a composition containing a dichroic dye and a polymerizable compound as a polarizer. Film etc. As the dichroic dye, specifically, iodine or a dichroic organic dye can be used. Dichroic organic dyes include dichroic direct dyes containing C.I. Direct Red 39 and other bisazo compounds, and dichroic direct dyes containing compounds such as trisazo and tetraazo.

As a polarizer, a film formed by coating and curing a composition containing a dichroic dye and a polymerizable compound, including coating a composition containing a dichroic pigment having liquid crystallinity, or a film containing two colors A film containing a cured product of a polymerizable liquid crystal compound, such as a layer obtained by curing the composition of a polymerizable liquid crystal and a polymerizable liquid crystal. A film formed by applying and curing a composition containing a dichroic dye and a polymerizable compound has no limitation on the bending direction, and therefore is preferable.

The linear polarizing plate may be composed of only a polarizing plate, or may include, in addition to the polarizing plate, a protective layer, a thermoplastic resin film, a substrate, an alignment film, and a protective layer described later. The thickness of the linear polarizing plate is, for example, 2 μm or more and 100 μm or less, preferably 10 μm or more and 60 μm or less.

(1) Linear polarizer with stretched film or stretched layer as polarizer First, a linear polarizing plate provided with a stretched film to which a dichroic dye is adsorbed as a polarizing plate will be described. As a polarizer, a stretched film adsorbing a dichroic dye can usually be manufactured through the following steps: a step of uniaxially stretching a polyvinyl alcohol-based resin film; A step of dyeing to adsorb the dichroic pigment; and a step of treating the polyvinyl alcohol-based resin film with the dichroic pigment adsorbed with a boric acid aqueous solution; and a step of washing with water after the treatment with the boric acid aqueous solution. This polarizing plate can be used as a linear polarizing plate as it is, or a polarizing plate in which a thermoplastic resin film described later is bonded to one or both sides of the polarizing plate can be used as a linear polarizing plate. The thickness of the polarizing plate is preferably 2 μm or more and 40 μm or less.

The polyvinyl alcohol-based resin is obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and other monomers copolymerizable therewith is used. 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.

The degree of saponification of the polyvinyl alcohol-based resin is usually 85 mol% to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may also be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 or more and 10,000 or less, preferably 1,500 or more and 5,000 or less.

Next, a description will be given of a linear polarizing plate provided with a stretched layer to which a dichroic dye is adsorbed as a polarizing plate. The stretched layer of the polarizing plate to which the dichroic dye is adsorbed can usually be manufactured through the following steps: the step of applying the coating solution containing the above-mentioned polyvinyl alcohol-based resin on the base film, and the resulting laminated film The step of axial stretching, the step of dyeing the polyvinyl alcohol resin layer of the monoaxially stretched laminate film with a dichroic dye, and adsorbing the dichroic dye to prepare a polarizer, using a boric acid aqueous solution The step of treating the film on which the dichroic dye is adsorbed, and the step of washing with water after treatment with an aqueous boric acid solution. If necessary, the base film can be peeled and removed from the polarizer. The material and thickness of the base film may be the same as the material and thickness of the thermoplastic resin film described later.

The polarizing plate as a stretched film or stretched layer may be assembled in a laminate in a form in which a thermoplastic resin film is bonded on one or both sides. This thermoplastic resin film can function as a protective film or retardation film for polarizing plates. The thermoplastic resin film may be, for example, a film containing resins such as polyolefin resins such as chain polyolefin resins (polypropylene resins, etc.), cyclic polyolefin resins (norbornene resins, etc.); triethyl Cellulose resins such as cellulose; polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; polycarbonate resins; (methyl) Acrylic resin; or a mixture of these.

From the viewpoint of thinning, the thickness of the thermoplastic resin film is usually 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, still more preferably 80 μm or less, further preferably 60 μm or less, and usually 5 μm or more, preferably 20 μm or more. The thermoplastic resin film may or may not have a phase difference. The thermoplastic resin film can be bonded to a polarizing plate using an adhesive layer, for example.

(2) A linear polarizing plate equipped with a film formed by coating and curing a composition containing a dichroic dye and a polymerizable compound as a polarizer A linear polarizing plate provided with a film obtained by coating and curing a composition containing a dichroic dye and a polymerizable compound as a polarizer will be described. As a polarizer, a film formed by coating and curing a composition containing a dichroic dye and a polymerizable compound may include: coating a composition containing a liquid crystal dichroic dye on a substrate, Or a film obtained by hardening a composition containing a dichroic dye and a liquid crystal compound. The film can be peeled off or used as a linear polarizing plate together with the base material, or a configuration having a thermoplastic resin film on one or both sides thereof can also be used as a linear polarizing plate.

The substrate may be a thermoplastic resin film. The example and thickness of the base material may be the same as those exemplified in the description of the above-mentioned thermoplastic resin film. The substrate may be a thermoplastic resin film having a hard coat layer, an anti-reflection layer, or an anti-static layer on at least one surface. The substrate may be formed with a hard coat layer, an anti-reflection layer, an anti-static layer, etc., only on the surface on the side where the polarizing plate is not formed. The base material may form a hard coat layer, an anti-reflection layer, an anti-static layer, etc. only on the surface of the side on which the polarizing plate is formed. The example of the hard coat layer is the same as the example of the composition for HC layer formation in the description of the said front surface board.

As a thermoplastic resin film, the same thing as the linear polarizing plate provided with the said stretched film or a stretched layer as a polarizing plate is mentioned. The thermoplastic resin film can be bonded to a polarizing plate using an adhesive layer, for example.

The film formed by applying and curing a composition containing a dichroic dye and a polymerizable compound is preferably thin, but if the film is too thin, the strength decreases and the workability tends to deteriorate. The thickness of the film is usually 20 μm or less, preferably 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less.

As a film formed by applying and curing a composition containing a dichroic dye and a polymerizable compound, specifically, Japanese Patent Laid-Open No. 2013-37353 or Japanese Patent Laid-Open No. 2013-33249 can be cited. The film described in.

(Alignment film) The alignment film can be arranged between the above-mentioned substrate and a layer of a cured product of a composition containing a dichroic dye having liquid crystallinity, or a composition containing a dichroic dye and a liquid crystal compound. The alignment film has an alignment restricting force to align the liquid crystal layer formed thereon in a desired direction. Examples of the alignment film include an alignment polymer layer containing an alignment polymer, a photoalignment polymer layer containing a photoalignment polymer, and a groove-groove alignment with a concave-convex pattern or a plurality of grooves on the layer surface. membrane. The thickness of the alignment film may be, for example, 10 nm or more and 500 nm or less, preferably 10 nm or more and 200 nm or less.

The aligning polymer layer can be formed by coating a composition obtained by dissolving the aligning polymer in a solvent on a substrate, removing the solvent, and performing a rubbing treatment as necessary. In this case, the alignment restriction force in the alignment polymer layer containing the alignment polymer can be arbitrarily adjusted according to the surface state of the alignment polymer or the friction conditions.

The photo-alignable polymer layer can be formed by coating a composition containing a polymer or monomer having a photoreactive group and a solvent on the substrate layer and irradiating it with polarized light. In this case, the alignment restriction force in the photoalignment polymer layer can be arbitrarily adjusted according to the polarized light irradiation conditions of the photoalignment polymer.

The groove alignment film can be formed, for example, by a method in which a concave-convex pattern is formed by exposing, developing, etc., the surface of the photosensitive polyimide film through an exposure mask having a pattern-shaped slit; A method in which an uncured layer of active energy ray curable resin is formed on a plate-shaped master disk with grooves on the surface, and the layer is transferred to the base material and cured; by forming active energy rays on the base material, it is hardened A method of forming an uncured layer of a flexible resin, and pressing a roll-shaped master disk with unevenness on the layer to form unevenness, and curing the layer.

(The protective layer) The protective layer can be used to protect the surface of the polarizer. When the linear polarizing plate includes a thermoplastic resin film, the protective layer may be arranged on the opposite side of the polarizing plate to the thermoplastic resin film. As the protective layer, the resin film exemplified as the material of the above-mentioned thermoplastic resin film may be contained, or it may be a coating type protective layer. The coating type protective layer may be, for example, a protective layer formed by coating and curing a cationic curable composition such as epoxy resin or a radical curable composition such as (meth)acrylate, or a coating poly The protective layer formed by drying aqueous solutions of vinyl alcohol resins, etc., may contain plasticizers, ultraviolet absorbers, infrared absorbers, coloring agents such as pigments or dyes, fluorescent whitening agents, dispersants, and Heat stabilizer, light stabilizer, antistatic agent, antioxidant, slip agent, etc.

The thickness of the protective layer can be, for example, 200 μm or less, and preferably 0.1 μm or more and 100 μm or less.

(Retardation layer) The retardation layer may include one or more retardation layers. The retardation layer may be a positive A layer and a positive C layer such as a λ/4 layer and a λ/2 layer. The retardation layer may include the resin film exemplified as the material of the above-mentioned thermoplastic resin film, or may include a layer formed by curing a polymerizable liquid crystal compound. The retardation layer may further contain an alignment film or a substrate. The thickness of the retardation layer may be, for example, 1 μm or more and 50 μm or less.

(Adhesive layer) The first adhesive layer is an adhesive layer of the circular polarizing plate 20 with adhesive layers on both sides. The first adhesive layer is arranged for bonding the circular polarizing plate 20 with adhesive layers on both sides and the front surface plate 10 together. The second adhesive layer is an adhesive layer of the circular polarizing plate 20 with adhesive layers on both sides. The second adhesive layer is arranged to bond the circularly polarizing plate 20 with adhesive layers on both sides and the back plate described later. The adhesive layer can be formed using an adhesive composition. The adhesive layer may have a single-layer structure or a multilayer structure, but is preferably a single-layer structure. The first adhesive layer and the second adhesive layer may each include the same type of adhesive layer, or may also include different types of adhesive layers.

The adhesive composition may be an adhesive composition mainly composed of resins such as (meth)acrylic, rubber, urethane, ester, silicone, or polyvinyl ether. Among them, an adhesive composition using a (meth)acrylic resin excellent in transparency, weather resistance, heat resistance, etc., as a base polymer is preferred. The adhesive composition can be an active energy ray hardening type or a heat hardening type.

As the (meth)acrylic resin (raw polymer) used in the adhesive composition, for example, butyl (meth)acrylate, methyl (meth)acrylate, and ethyl (meth)acrylate are preferably used. , Hexyl (meth)acrylate, octyl (meth)acrylate, lauryl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, 2-(meth)acrylate A polymer or copolymer in which one or two or more of (meth)acrylates such as ethylhexyl and isobornyl (meth)acrylate are used as monomers.

The base polymer is preferably copolymerized with a polar monomer. Examples of polar monomers include (meth)acrylic acid, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide, N,N-dimethyl A monomer having a carboxyl group, a hydroxyl group, an amino group, an amino group, an epoxy group, etc., such as an amino group ethyl (meth)acrylate and glycidyl (meth)acrylate.

The adhesive composition may only contain the base polymer, but usually contains a crosslinking agent. Examples of the crosslinking agent include: a metal ion having a valence of two or more and forming a carboxylic acid metal salt with a carboxyl group; a polyamine compound forming an amide bond with a carboxyl group; a polyepoxy compound or Polyols, which form ester bonds with carboxyl groups; polyisocyanate compounds, which form amide bonds with carboxyl groups. Among them, polyisocyanate compounds are preferred.

The so-called active energy ray-curable adhesive composition refers to the following adhesive composition, which has the property of being irradiated with active energy rays such as ultraviolet rays or electron rays to be cured, and thus has adhesiveness before active energy ray irradiation It can be closely adhered to adherends such as films, and can be cured by the irradiation of active energy rays to adjust the properties of adhesion.

The active energy ray curable adhesive composition is preferably an ultraviolet curable adhesive composition. The active energy ray-curable adhesive composition contains an active energy ray polymerizable compound in addition to the raw material polymer and crosslinking agent. In addition, if necessary, a photopolymerization initiator, photosensitizer, etc. are also contained.

As the active energy ray polymerizable compound, for example, a (meth)acrylate monomer having at least one (meth)acryloyloxy group in the molecule; obtained by reacting two or more functional group-containing compounds and having (Meth)acrylic compounds such as (meth)acryloxy group-containing compounds such as (meth)acrylic acid ester oligomers of at least two (meth)acryloxy groups.

The adhesive composition may contain fine particles, beads (resin beads, glass beads, etc.), glass fibers, resins other than raw polymers, tackifiers, fillers (metal powder or other inorganic powders, etc.) for imparting light scattering properties. , Antioxidants, UV absorbers, antistatic agents, dyes, pigments, colorants, defoamers, anticorrosive agents, photopolymerization initiators and other additives.

The adhesive layer can be formed by coating the adhesive composition, for example, an organic solvent diluent on the substrate, and drying it. When an active energy ray-curable adhesive composition is used, by irradiating the formed adhesive layer with active energy rays, a cured product having a desired degree of curing can be obtained.

The thickness of the first adhesive layer and the second adhesive layer are, for example, 0.5 μm or more and 100 μm or less, preferably 0.7 μm or more and 50 μm or less, and more preferably 1 μm or more and 30 μm or less.

The storage elastic coefficient of the adhesive layer at 25° C. is preferably 0.01 MPa to 1.0 MPa, more preferably 0.02 MPa to 0.1 MPa. The storage elasticity coefficient is measured under the following conditions, for example. A plurality of adhesive layers are laminated with a thickness of 0.6 mm. A cylinder with a diameter of 8 mm (height 0.6 mm) was punched out from the obtained adhesive layer and used as a sample for measuring the coefficient of storage elasticity. According to Japanese Industrial Standards (JIS) K7244-6, the viscoelasticity measuring device can be used to measure by the torsion shear method. The frequency can be set to 1 Hz.

[Other elements] The laminate 100 may be bonded to the back plate via the second adhesive layer. Examples of the back panel include display elements such as touch sensor panels and organic EL display elements, or combinations of these.

FIG. 2 shows a schematic cross-sectional view of a laminate 200 of another form. The laminated body 200 includes a front surface plate 10 and a circular polarizing plate 20 with adhesive layers on both sides. The circular polarizer 20 with adhesive layers on both sides has a first adhesive layer 30, a linear polarizer 40, a bonding layer 50, a retardation layer 60, and a second adhesive layer 70 in this order, and the linear polarizer 40 has a base material in turn 41. The alignment film 42, the polarizer 43, and the protective layer 44. The retardation layer 60 has a λ/4 layer 61, a bonding layer 62, and a positive C layer 63 in this order.

(Laminated layer) The bonding layer 50 and the bonding layer 62 are an adhesive layer or an adhesive layer, and can be formed using an adhesive composition or an adhesive composition. The bonding layer may be a single-layer structure or a multilayer structure, but preferably a single-layer structure. The adhesive composition may be the same as the adhesive composition exemplified in the description of the above-mentioned adhesive layer.

The adhesive composition may be a well-known adhesive composition, and examples thereof include: aqueous adhesive compositions such as polyvinyl alcohol-based resin aqueous solutions and aqueous two-component urethane-based emulsion adhesives; Active energy ray curable adhesive composition etc. cured by irradiating active energy rays such as ultraviolet rays.

The thickness of the bonding layer 50 and the bonding layer 62 is, for example, 0.5 μm or more and 100 μm or less, preferably 0.7 μm or more and 50 μm or less, and more preferably 1 μm or more and 30 μm or less.

The laminated body 200 can be manufactured by a method including the step of bonding the layers constituting the laminated body to each other via an adhesive layer or an adhesive layer. When bonding the layers to each other via an adhesive layer or an adhesive layer, in order to improve adhesion, it is preferable to perform surface activation treatment such as corona treatment on one or both of the bonding surfaces.

The polarizing plate 43 may be formed on the substrate 41 via the alignment film 42. The polarizing plate 43 can be formed by coating and curing a composition for forming a polarizing plate containing a dichroic dye and a polymerizable liquid crystal compound. In addition to the aforementioned dichroic dye and polymerizable liquid crystal compound, the composition for forming a polarizer preferably further contains a polymerization initiator, a leveling agent, and a solvent, and may further contain a photosensitizer, a polymerization inhibitor, and the like.

The retardation layer 60 can be manufactured by coating a composition for forming a retardation layer containing a polymerizable liquid crystal compound on the substrate and when the alignment film is present, and polymerizing the polymerizable liquid crystal compound. The composition for forming the retardation layer further contains a solvent and a polymerization initiator, and may further contain a photosensitizer, a polymerization inhibitor, a leveling agent, and the like. The base material and the alignment film may be formed in the retardation layer, or may be peeled from the retardation layer without becoming a constituent element of the laminate.

The coating and drying of the composition for forming a polarizer and the composition for forming a retardation layer, and the polymerization of the polymerizable liquid crystal compound can be performed by a conventionally known coating method, drying method, and polymerization method.

The adhesive layer 30 and the adhesive layer 70 can be prepared as adhesive sheets. The adhesive sheet can be produced, for example, by dissolving or dispersing the adhesive composition in an organic solvent such as toluene or ethyl acetate to prepare an adhesive liquid, and using it to form a sheet on a release film that has been subjected to a mold release treatment. A layer containing an adhesive is formed in a shape, and another release film is attached to the adhesive layer. Each layer can be attached by attaching the adhesive sheet from which one release film is peeled to one layer, then peeling off the other release film, and attaching the other layer. The laminated body 200 can be manufactured by attaching a circularly polarizing plate on which the adhesive layer 30 and the adhesive layer 70 are formed to the front surface plate 10, or by joining the front surface plate 10 on which the adhesive layer 30 is formed and the The circular polarizing plate with the adhesive layer 70 is laminated to manufacture, and it can be manufactured by bonding the front surface plate 10 on which the adhesive layer 30 is formed and the circular polarizing plate to form the adhesive layer 70.

＜Image display device＞ The image display device is not particularly limited, and examples thereof include organic electroluminescence (organic (electroluminescence, EL)) display devices, inorganic electroluminescence (inorganic EL) display devices, liquid crystal display devices, touch panel display devices, Electroluminescence display devices, etc. Since the image display device of this embodiment has a flexible laminated body, it can be used suitably for a flexible display, and is especially suitable for an organic EL display device. [Example]

Hereinafter, the present invention will be explained in more detail with examples. In the example, "%" and "parts" are mass% and mass parts unless otherwise specified.

[Layer thickness] The measurement was performed using a contact-type film thickness measurement device ("MS-5C" manufactured by Nikon Co., Ltd.). However, the polarizing plate, retardation layer, and alignment film were measured using a laser microscope (LEXT, manufactured by Olympus Co., Ltd.).

[Measurement method of tensile elasticity coefficient] The tensile modulus of elasticity is measured in accordance with JIS K7161 using a universal testing machine (UTM (Universal Testing Machine, autograph) AG-X, Shimadzu Corporation). Regarding the tensile conditions, under a humid and heat resistant environment (temperature 60℃, humidity 90%RH), the speed is set to 4 mm/min, the width is set to 10 mm, and the punctuation distance is set to 50 mm.

[Ups and Downs Evaluation] On the laminate obtained in each of the Examples and Comparative Examples, a polyethylene terephthalate (PET) film was bonded via an adhesive layer provided in the laminate to obtain a test piece. The PET film imitates an image display element, and its thickness is 100 μm. The laser cut test piece was subjected to a damp and heat resistance bending test under the following conditions, and then the undulation of the bent portion was measured using an interference microscope. Regarding the undulations, the interference microscope is installed so that the front surface of the laminate is located above, as the height of the highest and lowest portions of the unevenness observed by the interference microscope on the front surface of the curved portion of the laminate. The average of the difference (n=6) is calculated. (Damp heat resistance bending test) In the state where the laminated body is bent with a radius of curvature of 1 mm (1R) with the front surface plate side on the inside, it is left for 10 days in an atmosphere with a temperature of 60°C and a relative humidity of 90%RH.

[Visibility] Regarding the laminate after the undulation evaluation, the bent state was released to be in a flat state. The laminated body was set under a fluorescent lamp so that the front panel side was upward, and the image of the fluorescent lamp reflected on the surface of the laminated body was observed. In the curved part, the case where no distortion is observed in the image of the fluorescent lamp is set as ○, and the case where distortion is observed in the image of the fluorescent lamp is set as ×.

[Front Panel 1] (Polyamide imide film) In a nitrogen atmosphere, add 14.67g (45.8) of 2,2'-bis(trifluoromethyl)benzidine (TFMB) to a 1L separable flask equipped with a stirring blade mmol) and 233.3 g of N,N-dimethyl acetamide (DMAc) whose water content is adjusted to 200 ppm, while stirring at room temperature, dissolve TFMB in DMAc. Next, 4.283 g (13.8 mmol) of 4,4'-oxy diphthalic dianhydride (4,4'-oxy diphthalic dianhydride, OPDA) was added to the flask, and it was stirred at room temperature for 16.5 hours. Then, 4,4'-oxy bis (benzoyl chloride) (4,4'-oxy bis (benzoyl chloride), OBBC) 1.359 g (4.61 mmol) and terephthaloyl chloride (terephthaloyl chloride) were added to the flask. chloride, TPC) 5.609 g (27.6 mmol), stirred at room temperature for 1 hour. Next, 4.937 g (48.35 mmol) of acetic anhydride and 1.501 g (16.12 mmol) of 4-picoline were added to the flask, and after stirring at room temperature for 30 minutes, the temperature was raised to 70°C in an oil bath, and stirred for 3 hours to obtain The reaction solution. After the obtained reaction liquid was cooled to room temperature, 360 g of methanol and 170 g of ion-exchanged water were added to obtain a precipitate of polyimide. This was immersed in methanol for 12 hours, filtered and recovered, and washed with methanol. Next, the precipitate was dried under reduced pressure at 100° C. to obtain a polyamideimide (PAI) resin with a thickness of 50 μm.

(Composition 1 for HC layer formation) Composition 1 for HC layer formation contains: 30 parts by mass of multifunctional acrylate (Miramer M340, manufactured by Miwon Specialty Chemical), propylene glycol monomethyl ether dispersion of nanosilica gel Body (12 nm, solid content 40%) 50 parts by mass, 17 parts by mass of ethyl acetate, photopolymerization initiator (Irgacure-184, manufactured by Ciba Corporation) 2.7 parts by mass 0.3 parts by mass of fluorine-based additives (KY1203, manufactured by Shin-Etsu Chemical Co., Ltd.).

(Preparation of the front surface plate 1) The composition for forming the HC layer was coated on one surface of the polyimide film, and the obtained coating film was dried at a temperature of 80°C for 5 minutes, and ultraviolet (Ultraviolet, UV) irradiation device (SPOT CURE SP-7, manufactured by USHIO Electric Co., Ltd.), irradiates UV light with an exposure amount of 500 mJ/cm ² (365 nm standard) to form the HC layer 1. The coating is applied so that the thickness after curing becomes 10.0 μm. As described above, the front surface plate 1 having a polyamideimide film with a 1/50 μm HC layer was obtained.

[Front surface plate 2] In the preparation of the polyamide imide film of the front surface plate 1, 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA) 6.140 g was used instead of OPDA4.283 g , Instead of TFMB 14.67 g (45.8 mmol) and use TFMB 8.809 g (27.5 mmol) and 2,2'-dimethyl benzidine MB 3.889 g (18.3 mmol), and the front surface plate 1 Preparation of polyimide film Similarly, a polyimide resin having a thickness of 40 μm was obtained.

[Front panel 3] Prepare cycloolefine (COP) film (thickness 40 μm, manufactured by Zeon Co., Ltd.).

[Front Panel 4] Prepared Triacetyl Cellulose (TAC) membrane (thickness 40 μm).

[Preparation of composition for forming polarizing plate] (Polymerizable liquid crystal compound) As the polymerizable liquid crystal compound, a polymerizable liquid crystal compound represented by formula (1-6) [hereinafter also referred to as compound (1-6)] and a polymerizable liquid crystal compound represented by formula (1-7) [hereinafter also referred to as compound (1-7)].

[化1]

[化2]

Compounds (1-6) and compounds (1-7) were written by Lub et al., "Royal Dutch Journal of Chemistry, Recl.Trav.Chim.Pays-bas", 115, 321-328 ( 1996).

(Dichroic pigment) As the dichroic dye, the azo dye described in the examples of JP 2013-101328 A represented by the following formulas (2-1a), (2-1b), and (2-3a) is used.

[化3]

[化4]

[化5]

(Preparation of composition for forming polarizing plate) The composition for forming a polarizer comprises 75 parts by mass of compound (1-6), 25 parts by mass of compound (1-7), and the above formulas (2-1a), (2-1b), ( 2-3a) 2.5 parts by mass of each of the azo dyes, 2-dimethylamino-2-benzyl-1-(4-morpholinylphenyl)butane-1- as a polymerization initiator 6 parts by mass of ketone (Irgacure 369, manufactured by BASF Japan), 1.2 parts by mass of polyacrylate compound (BYK-361N, manufactured by BYK-Chemie) as a leveling agent, and as a solvent 400 parts by mass of toluene were mixed, and the resulting mixture was stirred at 80°C for 1 hour to prepare.

[Adhesive layer 1] The adhesive composition forming the adhesive layer 1 was prepared at the ratio of each component shown in Table 1 below. The adhesive composition was coated on the release-treated surface of the release-treated polyethylene terephthalate film (thickness 38 μm) with an applicator so that the thickness after drying was 25 μm. The coating layer was dried at 100° C. for 1 minute to obtain a film including the adhesive layer 1. Then, another polyethylene terephthalate film (thickness 38 μm) that was subjected to a mold release treatment was bonded to the adhesive layer 1. Then, it was cured for 7 days at a temperature of 23°C and a relative humidity of 50%RH. The symbols in the monomer column in Table 1 have the following meanings. BA: Butyl acrylate MMA: methyl acrylate EHA: 2-ethylhexyl acrylate AA: Acrylic The crosslinking agent and silane coupling agent in Table 1 used the following substances. Cross-linking agent: Coronate L (manufactured by Tosoh Corporation) Silane coupling agent: KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.)

[Adhesive layer 2] The film provided with the adhesive layer 2 was obtained in the same manner as the adhesive layer 1 except that the thickness after drying was 5 μm.

[Adhesive layer 3] The adhesive composition forming the adhesive layer 3 was prepared at the ratio of each component shown in Table 1 below. The adhesive composition was coated on the release-treated surface of the release-treated polyethylene terephthalate film (thickness 38 μm) with an applicator so that the thickness after drying was 5 μm. The coating layer was dried at 100° C. for 1 minute to obtain a film including the adhesive layer 3. Then, another polyethylene terephthalate film (thickness: 38 μm) that was subjected to a mold release treatment was attached to the adhesive layer. Then, it was cured for 7 days under the conditions of a temperature of 23°C and a relative humidity of 50%RH.

[表1] Table (表)1 Adhesive composition [mass parts] Storage elasticity coefficient G'[MPa] at 25℃ Thickness [μm] Monomers constituting (meth)acrylic resin Crosslinking agent Silane coupling agent BA MMA HEA AA Adhesive layer 1 98 4 0 1 0.6 0.5 0.5 0.08 25 Adhesive layer 2 98.4 0 1 0.6 0.5 0.5 0.08 5 Adhesive layer 3 68 30 1 1 3 0.5 0.7 5

[Substrate 1] Prepare a triacetyl cellulose (TAC) film (thickness 25 μm).

[Substrate 2] (Composition 2 for HC layer formation) Make 18-functional dendrimer acrylate (Miramer SP1106, Miwon Specialty Chemical Company) 2.0 parts by mass, 6 Functional urethane acrylate with acryl group (Miramer PU-620D, Miwon Speciality Chemical) 10.0 parts by mass, trifunctional acrylate with acryl group 8 parts by mass of monomer (M340, Miwon Speciality Chemical), 2 parts by mass of photopolymerization initiator (Irgacure (registered trademark) 184, made by BASF), and 0.1 parts by mass of leveling agent (BYK-UV3530, BYK-Chemie Japan Co., Ltd.) was dissolved in 70 parts by mass of methyl ethyl ketone (MEK) and stirred and mixed to obtain a hard coat Formation composition 2.

(Production of base material 2) The above-mentioned HC layer forming composition 2 was coated on one side of a cycloolefin (COP) film (thickness 13 μm), and the obtained coating film was dried at a temperature of 80°C for 5 minutes, A UV irradiation device (SPOT CURE SP-7, manufactured by USHIO Electric Co., Ltd.) was used to irradiate UV light with an exposure amount of 500 mJ/cm ² (365 nm standard) to form the HC layer 2. The coating is applied so that the thickness after curing reaches 2 μm. As described above, substrate 2 is obtained.

[λ/4 layer] 5 parts (weight average molecular weight: 30,000) of a photo-alignment material of the following structure and 95 parts of cyclopentanone were mixed, and the resulting mixture was stirred at 80°C for 1 hour, thereby obtaining a composition for forming a horizontal alignment film .

[化6]

With respect to 100 parts of a mixture of the following polymerizable liquid crystal compound A and polymerizable liquid crystal compound B in a mass ratio of 90:10, 1.0 part of leveling agent (F-556; DIC) is added Manufactured by the company), and 6 parts of 2-dimethylamino-2-benzyl-1-(4-morpholinylphenyl)butan-1-one (Irgacure )369 (Irg369)", manufactured by BASF Japan Co., Ltd.).

N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration was 13%, and the mixture was stirred at 80°C for 1 hour to obtain a composition for forming a retardation layer ( 1).

The polymerizable liquid crystal compound A is produced by the method described in JP 2010-31223 A. In addition, the polymerizable liquid crystal compound B is produced by the method described in JP 2009-173893 A. The molecular structure of each is shown below.

(Polymerizable liquid crystal compound A)

[化7]

(Polymerizable liquid crystal compound B)

[化8]

Using a corona treatment device (AGF-B10, manufactured by Kasuga Electric Co., Ltd.), under the conditions of an output of 0.3 kW and a processing speed of 3 m/min, the film containing cycloolefin polymer (COP) (Zeon Co., Ltd., Japan) The base film made by the company, ZF-14, thickness 23 μm) was corona treated once. The composition for forming a horizontal alignment film was coated on the surface of the corona-treated substrate using a bar coater. The coating film was dried at 80° C. for 1 minute, and polarized UV exposure was performed using a polarized UV irradiation device (SPOT CURE SP-7; manufactured by Ushio (USHIO) Electric Co., Ltd.) with a cumulative light amount of 100 mJ/cm ² . The thickness of the obtained horizontal alignment film was measured with a laser microscope (LEXT, manufactured by Olympus Co., Ltd.) and it was 100 nm.

Next, the composition (1) for forming the retardation layer was passed through a PTFE membrane filter with a pore size of 0.2 μm (Advantec Toyo Co., Ltd.) under an environment of room temperature 25°C and humidity 30%RH. Manufacture, product number: T300A025A), and use a bar coater to coat it on a substrate film with an alignment film kept at 25°C. After drying the coating film at 120°C for 1 minute, use a high-pressure mercury lamp (UNICURE VB-15201BY-A, manufactured by USHIO Electric Co., Ltd.) to irradiate ultraviolet rays (under nitrogen atmosphere, wavelength: 365) nm, the cumulative amount of light at a wavelength of 365 nm: 1000 mJ/cm ² ) to produce an optical film. The thickness of the obtained coating film was measured with a laser microscope (LEXT, manufactured by Olympus Co., Ltd.) and found to be 2 μm.

In this way, a layered body (retardation layer 1) in which a layer (λ/4 layer) formed by curing a polymerizable liquid crystal compound, a horizontal alignment film, and a base film are sequentially laminated is obtained. The retardation layer 1 shows reverse wavelength dispersion.

[Positive C floor] As a composition for forming a vertical alignment film, 2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, dipentaerythritol triacrylate, and bis(2-vinyloxy) were mixed in a ratio of 1:1:4:5. Ethyl ether, as a polymerization initiator, a mixture obtained by adding LUCIRIN TPO at a ratio of 4% was used.

The composition (2) for forming the retardation layer is prepared by preparing a photopolymerizable nematic liquid crystal compound (manufactured by Merck, RMM28B) and a solvent to have a solid content of 1 g to 1.5 g. The solvent uses methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK) and cyclohexanone (CHN) in a mass ratio (MEK: MIBK: CHN) as 35:30: A mixed solvent in the ratio of 35.

Prepare a polyethylene terephthalate (PET) film with a thickness of 38 μm as the base film. The composition for forming a vertical alignment film was coated on one side of the base film so that the film thickness was 3 μm, and the vertical alignment film was irradiated with 200 mJ/cm ² of ultraviolet rays to produce a vertical alignment film.

The composition for forming a retardation layer (2) is coated on the vertical alignment layer by a die coating method. The coating amount is 4 g (wet) to 5 g (wet). The coating film was dried under the conditions of a drying temperature of 75°C and a drying time of 120 seconds. Then, ultraviolet (UV) is irradiated to the coating film to polymerize the polymerizable liquid crystal compound. The thickness of the obtained coating film was measured with a laser microscope (LEXT, manufactured by Olympus Co., Ltd.) and found to be 1 μm.

In this way, a layered body (retardation layer 2) in which a layer (positive C layer) formed by curing a polymerizable liquid crystal compound, a vertical alignment film, and a base film were sequentially laminated was obtained. In the retardation layer 2, the total thickness of the layer formed by curing the polymerizable liquid crystal compound and the alignment film is 4 μm.

[Phase Difference Layer] The above-mentioned retardation layer 1 and the retardation layer 2 were bonded via the adhesive layer 3 so that the surface opposite to the surface of the base film side became the bonding surface, to obtain a base film/horizontal alignment film/(λ /4 layer)/adhesive layer 3/positive C layer/vertical alignment film/base film composition retardation layer.

<Example 1> First, the base material 1 was prepared. The composition for forming an alignment film was coated on the substrate 1 by a bar coating method. The coating film was dried at 80°C for 1 minute. Next, the coating film was irradiated with polarized light UV using the above-mentioned UV irradiation device and the wire grid to impart alignment performance to the coating film. The exposure level is 100 mJ/cm ² (365 nm reference). The wire grid uses UIS-27132## (manufactured by USHIO Electric Co., Ltd.). In this way, an alignment film is formed. The thickness of the alignment film is 100 nm.

On the formed alignment film, the composition for forming a polarizer is coated by a bar coating method. After heating and drying the coating film at 100°C for 2 minutes, it was cooled to room temperature. Using the above-mentioned UV irradiation device, the coating film was irradiated with ultraviolet rays at a cumulative light amount of 1200 mJ/cm ² (365 nm reference) to form a polarizing plate. The thickness of the obtained polarizing plate was 3 μm. A composition containing polyvinyl alcohol and water was coated on the polarizing plate so that the thickness after drying was 0.5 μm, and dried at a temperature of 80° C. for 3 minutes to form a protective layer. In this way, a linear polarizing plate having a configuration of base material 1 / alignment film / polarizing plate / protective layer was produced.

After corona treatment is applied to the surface of the front surface plate 1 opposite to the HC layer 1 and the surface of the adhesive layer 1 exposed by peeling off one of the films with the adhesive layer 1 , Attach the two together.

Next, the surface of the adhesive layer 1 exposed by peeling the other polyethylene terephthalate film from the adhesive layer 1 and the surface of the linear polarizing plate on the side of the base material 1 are corona treated, and then they are pasted Together. Then, after corona treatment was performed on the surface of the protective layer side of the linear polarizer and the surface of the adhesive layer 3 exposed by peeling off one of the polyethylene terephthalate films of the film provided with the adhesive layer 3, the two者 Fitting. Next, another polyethylene terephthalate film is peeled from the adhesive layer 3 to expose the adhesive layer 3. In this way, a laminate having a constitution of front surface plate 1/adhesive layer 1/base material 1/alignment film/polarizer/protective layer/adhesive layer 3 was obtained.

The base film used for formation of the retardation layer 1 was peeled from the said retardation layer. The exposed λ/4 layer and the adhesive layer 3 are bonded together. The angle formed by the absorption axis of the polarizer and the slow axis of the λ/4 layer is 45°. Next, the base film for forming the retardation layer 2 is peeled off to expose the positive C layer. Then, another film provided with the adhesive layer 1 is prepared, and one of the polyethylene terephthalate films is peeled off to expose the surface of the adhesive layer 1. After corona treatment was performed on the exposed surface of the positive C layer and the surface of the adhesive layer 1, they were bonded together. Next, another polyethylene terephthalate film is peeled off from the adhesive layer 1. In this way, a front surface plate 1/adhesive layer 1/substrate 1/alignment film/polarizer/protective layer/adhesive layer 3/(λ/4 layer)/adhesive layer 3/positive C layer/adhesive is obtained The laminate of Example 1 with the structure of layer 1. The results are shown in Table 2. In Example 1, the circularly polarizing plate with adhesive layers on both sides includes adhesive layer 1/substrate 1/alignment film/polarizer/protective layer/adhesive layer 3/(λ/4 layer)/adhesive layer 3 /Positive C layer/Adhesive layer 1.

<Example 2> Except that the front surface plate 2 was used instead of the front surface plate 1 in Example 1, the laminate of Example 2 was obtained in the same manner as in Example 1. The results are shown in Table 2.

<Example 3> Except that the front surface plate 3 was used instead of the front surface plate 1 in Example 1, a laminate of Example 3 was obtained in the same manner as in Example 1. The results are shown in Table 2.

<Example 4> In Example 1, instead of preparing the substrate 1, the alignment film forming composition was coated on the substrate 1, and the substrate 2 was prepared, and the alignment film forming composition was coated on the HC layer 2 of the substrate 2. And, instead of using the film provided with the adhesive layer 1, except having used the film provided with the adhesive layer 2, it carried out similarly to Example 1, and obtained the laminated body of Example 4. The results are shown in Table 2.

<Comparative example 1> Except that in Example 4, the front surface 4 was used instead of the front surface plate 1, the laminate of Comparative Example 1 was produced in the same manner as in Example 4. The results are shown in Table 2.

[Table 2] Table 2 Example 1 Example 2 Example 3 Example 4 Comparative example 1 Front panel Front panel 1 Front panel 2 Front panel 3 Front panel 1 Front panel 4 Front panel composition (thickness in parentheses [μm]) HC layer 1 (10)/PAI (50) PAI (40) COP (40) HC layer 1 (10)/PAI (50) TAC (40) Front surface plate thickness (a) [μm] 60 40 40 60 40 Tensile coefficient of elasticity (c) [MPa] (60°C, 90%RH) 3103.4 4,157.1 1361.1 3103.4 731.4 Thickness of circular polarizer with adhesive layer on both sides (b) [μm] 94.6 94.6 94.6 44.6 44.6 [(B/a)×c] 4893 9831.5 3219.0 2306.9 815.5 a/c 0.019 0.01 0.029 0.019 0.055 Fluctuation [μm] 24.4 25.9 48.2 54.1 118.9 Visibility ○ ○ ○ ○ ×

10: Front panel 20: Circular polarizing plate with adhesive layer on both sides 30: The first adhesive layer/adhesive layer 40: Linear polarizer 41: Substrate 42: Alignment film 43: Polarizer 44: protective layer 50: Laminated layer 60: retardation layer 61:λ/4 layer 62: Laminated layer 63: Positive C layer 70: second adhesive layer/adhesive layer 100, 200: layered body

Fig. 1 is a schematic cross-sectional view showing a laminated body according to an aspect of the present invention. Fig. 2 is a schematic cross-sectional view showing a laminated body according to an aspect of the present invention.

10: Front panel

20: Circular polarizing plate with adhesive layer on both sides

100: layered body

Claims (6)

A laminated body comprising a front surface plate and a circular polarizing plate with adhesive layers on both sides, when the thickness of the front surface plate is set to a [μm], the circular polarizing plate with adhesive layers on both sides When the thickness is set to b [μm], and the tensile elasticity coefficient of the front surface plate at a temperature of 60° C. and a relative humidity of 90% RH is set to c [MPa], the laminate satisfies the following formula (1): [(B/a)×c]≧2200 (1). The laminated body according to claim 1, wherein the a and the c satisfy the following formula (2): a/c≦0.03 (2). The laminate according to claim 1 or 2, wherein the front surface plate has a hard coat layer. The laminate according to any one of claims 1 to 3, wherein the circularly polarizing plate with adhesive layers on both sides includes a first adhesive layer, a linear polarizing plate, a retardation layer, and a second adhesive layer in this order Agent layer. The laminate according to claim 4, wherein the linear polarizing plate includes a thermoplastic resin film having a hard coat layer on at least one surface. An image display device including the laminate according to any one of claims 1 to 5.

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