JP6735891B2 - Flexible laminate and image display device including the same - Google Patents

Description

The present invention relates to a flexible laminate and an image display device including the same.

In various image display devices such as a liquid crystal display device and an organic electroluminescence (EL) display device, there is known a flexible display capable of bending a display panel using a flexible base material (for example, Patent Documents 1 and 2).

Korean Published Patent No. 10-2016-0053788 Korean Published Patent No. 10-2017-0993610

A flexible base material has excellent flexibility characteristics, but tends to be inferior in impact resistance as compared with glass used in a conventional image display device.

An object of the present invention is to provide a flexible laminate having excellent impact resistance and an image display device including the same.

The present invention provides the following flexible laminate and image display device.
[1] A flexible laminate including a front plate, a first adhesive layer, a circularly polarizing plate, a second adhesive layer, and a touch sensor panel in this order,
The thickness of the front plate is a [μm], the thickness of the first pressure-sensitive adhesive layer is b [μm], the thickness of the circularly polarizing plate is c [μm], and the thickness of the second pressure-sensitive adhesive layer is d [μm]. , And the thickness of the touch sensor panel is e [μm], the following formula (1):
(B+d)/(a+b+c+d+e)≧0.2 (1)
Flexible laminate that satisfies the relationship of.

[2] The thickness b of the first pressure-sensitive adhesive layer and the thickness d of the second pressure-sensitive adhesive layer are represented by the following formula (2):
1≦b/d≦6 (2)
The flexible laminate according to [1], which satisfies the relationship of

[3] The flexible laminate according to [1] or [2], wherein the thickness b of the first adhesive layer is larger than the thickness d of the second adhesive layer.

[4] The thickness b of the first pressure-sensitive adhesive layer is 10 μm or more,
The thickness d of the said 2nd adhesive layer is a flexible laminated body in any one of [1]-[3] which is 10 micrometers or more.

[5] The rigidity of the front plate at a temperature of 23° C. and a relative humidity of 55% is 90 MPa·mm or more and 700 MPa·mm or less,
The rigidity of the circularly polarizing plate at a temperature of 23° C. and a relative humidity of 55% is 40 MPa·mm or more and 400 MPa·mm or less,
The flexible laminate according to any one of [1] to [4], wherein the touch sensor panel has a rigidity of 15 MPa·mm or more and 700 MPa·mm or less at a temperature of 23° C. and a relative humidity of 55%.

[6] The storage elastic modulus of the first pressure-sensitive adhesive layer at a temperature of 25° C. and a relative humidity of 50% is 0.01 MPa or more and 0.15 MPa or less,
The flexible laminate according to any one of [1] to [5], wherein the storage modulus of the second pressure-sensitive adhesive layer at a temperature of 25° C. and a relative humidity of 50% is 0.01 MPa or more and 0.15 MPa or less.

[7] Total thickness t of the thickness a of the front plate, the thickness b of the first adhesive layer, the thickness c of the circularly polarizing plate, the thickness d of the second adhesive layer, and the thickness e of the touch sensor panel. [Μm] is represented by the following formula (3):
t=a+b+c+d+e (3)
The flexible laminate according to any one of [1] to [6], wherein t is 250 μm or less.

[8] The flexible laminate according to any one of [1] to [7], wherein the front plate is a resin film or a resin film with a hard coat layer having a hard coat layer on at least one surface of the resin film. body.

[9] The flexible laminate according to any one of [1] to [8], wherein the flexible laminate has a limit number of bends of 50,000 times or more in a bending test.

[10] An image display device, comprising the flexible laminate according to any one of [1] to [9], wherein the front plate is arranged on the front surface.

ADVANTAGE OF THE INVENTION According to this invention, the flexible laminated body excellent in impact resistance and the image display apparatus provided with the same can be provided.

It is a schematic sectional drawing which shows an example of the flexible laminated body of this invention typically. It is a schematic sectional drawing which shows typically an example of the image display apparatus of this invention.

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 below, the scales are appropriately adjusted and shown to facilitate understanding of the respective components, and the scales of the respective components shown in the drawings do not necessarily match the actual scales of the components.

(Flexible laminate)
FIG. 1 is a schematic cross-sectional view schematically showing an example of the flexible laminate of this embodiment. The flexible laminate 100 includes a front plate 10, a first pressure-sensitive adhesive layer 20, a circularly polarizing plate 30, a second pressure-sensitive adhesive layer 40, and a touch sensor panel (hereinafter, also referred to as “TS panel”) 50. As shown in FIG. 1, the flexible laminate 100 includes a front plate 10, a first pressure-sensitive adhesive layer 20, a circularly polarizing plate 30, a second pressure-sensitive adhesive layer 40, and a TS panel 50, which are stacked in this order from the viewing side. There is.

The flexible laminate 100 has flexibility, and thus can be applied to an image display device (flexible display) that can be bent, rolled, and the like. The flexible laminate 100 of the present embodiment can be made particularly excellent in flexibility to bend with the front plate 10 side facing inward. Having flexibility means that the flexible laminate 100 can be bent without causing cracks. The flexible laminate 100 has flexibility such that the limit number of bends, which is the number of bends in which cracks and floating of the adhesive layer occur in the bent region, is 50,000 or more in a bendability test in Examples described later. Is preferable, and the limit number of flexing times is more preferably 100,000 times or more, and further preferably 200,000 times or more. The flexibility test can be performed by the method of Examples described later.

The flexible laminate 100 can form an image display device as described above, and can be particularly preferably used for a flexible display that can be bent or wound. Moreover, since the flexible laminate 100 includes the circularly polarizing plate 30, it can be used as an antireflection film in an organic electroluminescence (EL) display device, for example.

In the flexible laminate 100, the thickness of the front plate 10 is a [μm], the thickness of the first pressure-sensitive adhesive layer 20 is b [μm], the thickness of the circularly polarizing plate 30 is c [μm], and the second pressure-sensitive adhesive layer 40 is the same. When the thickness is d [μm] and the thickness of the TS panel 50 is e [μm], the following formula (1):
(B+d)/(a+b+c+d+e)≧0.2 (1)
Meet the relationship. Below, the total thickness t [μm] of the front plate 10, the first pressure-sensitive adhesive layer 20, the circularly polarizing plate 30, the second pressure-sensitive adhesive layer 40, and the TS panel 50 is represented by the following formula (3):
t=a+b+c+d+e (3)
May be expressed as.

(B+d)/t in the above formula (1) (where t is represented by the above formula (3)) is preferably 0.25 or more, and may be 0.3 or more. , 0.35 or more, usually 0.65 or less, and may be 0.6 or less.

Since the first pressure-sensitive adhesive layer 20 and the second pressure-sensitive adhesive layer 40 are layers formed of a pressure-sensitive adhesive, compared to other layers (front plate 10, circularly polarizing plate 30, TS panel 50) forming the flexible laminate 100. Therefore, the rigidity is low and the shock absorption tends to be excellent. Therefore, when the flexible laminate 100 satisfies the relationship of the formula (1), the first adhesive layer 20 and the second adhesive layer 40 can be formed in the flexible laminate 100 with a certain thickness or more. As a result, the impact resistance of the entire flexible laminate 100 can be improved and the impact resistance can be improved.

On the other hand, when the flexible laminate does not satisfy the relationship of the formula (1), the impact absorbability of the entire flexible laminate decreases, and as a result, the impact resistance tends to decrease.

In recent years, image display devices have been made thinner and lighter, and members used in the image display devices tend to be thinner and lighter, and thus the flexible laminate 100 is also required to have a smaller thickness. There is. When reducing the thickness of the flexible laminate 100, the thickness of each layer (the front plate 10, the first pressure-sensitive adhesive layer 20, the circularly polarizing plate 30, the second pressure-sensitive adhesive layer 40, the TS panel 50) forming the flexible laminate 100. Is required to be small. At this time, the front plate 10, the circularly polarizing plate 30, and the TS panel 50 usually need to have a certain thickness in order to realize the function of each layer. Therefore, it is necessary to reduce the thickness of these layers. There is a limit to. On the other hand, the first pressure-sensitive adhesive layer 20 and the second pressure-sensitive adhesive layer 40 can have a small thickness as long as the layers can be adhered to each other. 2 It has been found that when the thickness d of the pressure-sensitive adhesive layer 40 becomes too small, the strength required for the flexible laminate 100 tends to decrease. In the flexible laminate 100 of the present embodiment, the thickness b of the first pressure-sensitive adhesive layer 20 and the thickness d of the second pressure-sensitive adhesive layer 40 are set as described above with respect to the total thickness t represented by the above formula (3). Is set so as to satisfy the relationship of the expression (1). Therefore, even in the flexible laminate 100 having a small total thickness t described above, excellent impact resistance can be realized.

The total thickness t represented by the above formula (3) is not particularly limited and may be, for example, 1000 μm or less, but is 250 μm or less so as to correspond to thinning and exhibit good flexibility. Is more preferable, 220 μm or less is more preferable, 200 μm or less, 180 μm or less, 150 μm or less, usually 40 μm or more, and 70 μm or more may be preferable. ..

In the flexible laminate 100, the thickness b of the first pressure-sensitive adhesive layer 20 and the thickness d of the second pressure-sensitive adhesive layer 40 are expressed by the following formula (2):
1≦b/d≦6 (2)
It is preferable to satisfy the relationship of. Since the thickness b of the first adhesive layer 20 is preferably larger than the thickness d of the second adhesive layer 40, b/d in the above formula (2) is preferably more than 1. It is more preferably 0.2 or more, and may be 1.5 or more, or may be 2 or more. Further, b/d in the above formula (2) is preferably 5.5 or less, more preferably 5.2 or less, and may be 5 or less.

Since the flexible laminate 100 satisfies the relation of the above formula (1) and the thickness b of the first pressure-sensitive adhesive layer 20 and the thickness d of the second pressure-sensitive adhesive layer 40 have the relation of the above formula (2), In particular, it is possible to obtain the flexible laminate 100 having excellent flexibility in which the front plate 10 side is bent inside. According to the relationship of the above formula (2), when the flexible laminate 100 is bent with the front plate 10 side as the inner side, the stress generated in the front plate 10 is less likely to be transmitted to the circularly polarizing plate 30, so that the flexible plate is flexible. It is presumed that it is possible to suppress the occurrence of cracks inside the laminate 100 (in particular, the circularly polarizing plate 30).

The shape of the flexible laminated body 100 in the surface direction is not particularly limited, but it is preferably a rectangular shape, and more preferably a rectangular shape. When the flexible laminate 100 has a rectangular shape, the length of the long side is preferably 50 mm to 300 mm, may be 100 mm to 280 mm, and the length of the short side is, for example, 30 mm to 250 mm. Is preferable, and may be 60 mm to 220 mm. The flexible laminate 100 may have a rounded rectangular shape in which at least one of the corners of the rectangular shape is rounded, or a rectangular shape having a cutout portion on at least one side. Further, the flexible laminated body 100 may be provided with a hole penetrating in the laminating direction.

(Front plate)
The front plate 10 is a plate-shaped body that can function as a layer for protecting display elements and the like of the image display device and can transmit light, and the plate-shaped body is usually made of glass or resin. Is preferred. The front plate 10 may be arranged on the outermost surface of the image display device. The front plate 10 is preferably a resin film or a resin film with a hard coat layer in which a hard coat layer is provided on at least one surface of the resin film to further improve hardness. Further, the front plate 10 may have a blue light cut function, a viewing angle adjustment function, and the like.

The resin film forming the front plate 10 is not limited as long as it is a resin film capable of transmitting light. For example, triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, polyester, polystyrene, polyamide, polyetherimide, poly(meth)acrylic, polyimide, polyether. Sulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl (meth)acrylate, polyethylene terephthalate, polybutylene Examples thereof include films formed of polymers such as terephthalate, polyethylene naphthalate, polycarbonate and polyamide imide. These polymers may be used alone or in combination of two or more. When the image display device 300 is a flexible display, it is formed of a polymer such as polyimide, polyamide, or polyamideimide, which can be configured to have excellent flexibility, high strength, and high transparency. The resin film is preferably used.

The resin film with a hard coat layer forming the front plate 10 may have a hard coat layer on one side of the resin film, or may have a hard coat layer on both sides of the resin film. When the resin film has hard coat layers on both sides, the composition and thickness of each hard coat layer may be the same or different from each other. The resin film with a hard coat layer can improve hardness and scratch resistance as compared with a resin film having no hard coat layer.

The hard coat layer of the resin film with a hard coat layer is, for example, a cured layer of an ultraviolet curable resin. Examples of the ultraviolet curable resin include (meth)acrylic resins such as monofunctional (meth)acrylic resins, polyfunctional (meth)acrylic resins, and polyfunctional (meth)acrylic resins having a dendrimer structure; silicone resins. Resin; polyester resin; urethane resin; amide resin; epoxy resin and the like. The hard coat layer may contain an additive in order to improve the strength. The additive is not limited and includes inorganic fine particles, organic fine particles, or a mixture thereof.

The rigidity of the front plate 10 at a temperature of 23° C. and a relative humidity of 55% is preferably 90 MPa·mm or more, more preferably 150 MPa·mm or more, further preferably 200 MPa·mm or more, and It is preferably 700 MPa·mm or less, more preferably 500 MPa·mm or less, and further preferably 400 MPa·mm or less. When the rigidity of the front plate 10 decreases, the strength of the flexible laminate 100 tends to decrease, and when the rigidity of the front plate 10 increases, the flexibility of the flexible laminate 100 tends to decrease. Further, when the rigidity of the front plate 10 is in the above range, the flexible laminate 100 satisfying the above formula (1) can suitably obtain the flexible laminate 100 having excellent impact resistance. Further, when the flexible laminate 100 satisfies the relations of the above formulas (1) and (2), it is possible to preferably obtain the flexible laminate 100 having excellent flexibility and excellent impact resistance.

The rigidity of the front plate 10 is obtained by multiplying the tensile modulus Ea [MPa] of the front plate 10 at a temperature of 23° C. and a relative humidity of 55% by the thickness [mm] of the front plate 10 (Ea [MPa]×a [μm]× It can be calculated by 10 ⁻³ ). The thickness a of the front plate 10 may be, for example, 30 μm or more and 500 μm or less, preferably 50 μm or more and 250 μm or less, and more preferably 50 μm or more and 100 μm or less. The tensile modulus Ea of the front plate 10 may be, for example, 500 MPa or more and 10000 MPa or less, preferably 1000 MPa or more and 9000 MPa or less, more preferably 2000 MPa or more and 8000 MPa or less, and further preferably 3000 MPa or more and 7000 MPa or less.

The rigidity of the front plate 10 can be calculated by the product of the tensile elastic modulus [MPa] of the entire front plate 10 at a temperature of 23° C. and a relative humidity of 55% and the thickness of the entire front plate 10 [mm].

(First adhesive layer)
The first pressure-sensitive adhesive layer 20 is a layer for bonding the front plate 10 and the circularly polarizing plate 30 and can be formed using a pressure-sensitive adhesive composition. The thickness b of the first pressure-sensitive adhesive layer 20 is not particularly limited as long as it can satisfy the relationships of the above formulas (1) and (2), but is preferably 5 μm or more, more preferably 7 μm or more, The thickness is more preferably 10 μm or more, may be 20 μm or more, and is usually 100 μm or less, preferably 90 μm or less, and more preferably 80 μm or less.

The first adhesive layer 20 preferably has a storage elastic modulus Gb at a temperature of 25° C. and a relative humidity of 50% of 0.01 MPa or more, more preferably 0.05 MPa or more, and 0.07 MPa or more. Is more preferable, 0.15 MPa or less is preferable, 0.12 MPa or less is more preferable, and 0.1 MPa or less is further preferable.

When the storage elastic modulus Gb of the first pressure-sensitive adhesive layer 20 is not within the above range, the flexibility of the flexible laminate 100 tends to decrease. Further, when the storage elastic modulus Gb of the first pressure-sensitive adhesive layer 20 is in the above range, the flexible laminate 100 satisfies the above formula (1), so that the flexible laminate 100 excellent in impact resistance is preferably used. Obtainable. Further, when the flexible laminate 100 satisfies the relations of the above formulas (1) and (2), it is possible to preferably obtain the flexible laminate 100 having good flexibility and excellent impact resistance.

The first pressure-sensitive adhesive layer 20 can be composed of a pressure-sensitive adhesive composition containing a resin such as (meth)acrylic, rubber-based, urethane-based, ester-based, silicone-based, or polyvinyl ether-based resin as a main component. Among them, a pressure-sensitive adhesive composition containing a (meth)acrylic resin as a base polymer, which is excellent in transparency, weather resistance, heat resistance, etc., is preferable. The pressure-sensitive adhesive composition may be an active energy ray curable type or a thermosetting type.

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

The pressure-sensitive adhesive composition may contain only the above base polymer, but usually further contains a crosslinking agent. As the cross-linking agent, a metal ion having a valence of 2 or more and forming a carboxylic acid metal salt with a carboxyl group; a polyamine compound forming an amide bond with a carboxyl group; Examples thereof include epoxy compounds and polyols that form an ester bond with a carboxyl group; and polyisocyanate compounds that form an amide bond with a carboxyl group. Of these, polyisocyanate compounds are preferable.

The active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by being irradiated with an active energy ray such as an ultraviolet ray or an electron beam, and has adhesiveness even before irradiation with the active energy ray. It is a pressure-sensitive adhesive composition having a property that it can be brought into close contact with an adherend such as the above, and can be cured by irradiation with an active energy ray to adjust the adhesion. The active energy ray-curable pressure-sensitive adhesive composition is preferably UV-curable. The active energy ray-curable pressure-sensitive adhesive composition further contains an active energy ray-polymerizable compound in addition to the base polymer and the crosslinking agent. Further, if necessary, a photopolymerization initiator, a photosensitizer and the like may be contained.

The pressure-sensitive adhesive composition includes fine particles for imparting light-scattering properties, beads (resin beads, glass beads, etc.), glass fibers, resins other than the base polymer, tackifiers, fillers (metal powder and other inorganic powders). Etc.), antioxidants, ultraviolet absorbers, dyes, pigments, colorants, defoamers, corrosion inhibitors, photopolymerization initiators, and other additives.

The 1st adhesive layer 20 can be formed by apply|coating the organic solvent dilution liquid of the said adhesive composition on a base material, and making it dry. When the active energy ray-curable pressure-sensitive adhesive composition is used, the formed pressure-sensitive adhesive layer can be irradiated with an active energy ray to obtain a cured product having a desired degree of curing.

(Circular polarization plate)
The circularly polarizing plate 30 may include a linear polarizing plate 31 and a retardation layer 32. The linear polarizing plate 31 is disposed on the first adhesive layer 20 side and the retardation layer 32 is disposed on the second adhesive layer 40 side. Can be placed. The circularly polarizing plate 30 can convert light (external light) incident from the viewing side of the image display device having the flexible laminate 100 through the flexible laminate 100 into circularly polarized light. Since the circularly polarizing plate 30 can absorb the external light reflected by the display element, the flexible laminate 100 can be provided with a function as an antireflection film.

The circularly polarizing plate 30 preferably has a rigidity of 40 MPa·mm or more at a temperature of 23° C. and a relative humidity of 55%, more preferably 100 MPa·mm or more, further preferably 150 MPa·mm or more, and , 400 MPa·mm or less, more preferably 350 MPa·mm or less, further preferably 300 MPa·mm or less. When the rigidity of the circularly polarizing plate 30 decreases, the strength of the flexible laminate 100 tends to decrease, and when the rigidity of the circularly polarizing plate 30 increases, the flexibility of the flexible laminate 100 tends to decrease. Moreover, when the rigidity of the circularly polarizing plate 30 is in the above range, the flexible laminate 100 satisfying the above formula (1) can suitably obtain the flexible laminate 100 having excellent impact resistance. Further, when the flexible laminate 100 satisfies the relations of the above formulas (1) and (2), it is possible to preferably obtain the flexible laminate 100 having excellent flexibility and excellent impact resistance.

The rigidity of the circularly polarizing plate 30 is obtained by multiplying the tensile elastic modulus Ec [MPa] of the entire circularly polarizing plate 30 at a temperature of 23° C. and a relative humidity of 55% by the total thickness [mm] of the circularly polarizing plate 30 (Ec [MPa]× It can be calculated by c [μm]×10 ⁻³ ).

(Linear polarizing plate)
The linearly polarizing plate 31 has a function of selectively transmitting linearly polarized light in one direction from unpolarized light such as natural light. Examples of the linear polarizing plate 31 include a stretched film in which a dye having absorption anisotropy is adsorbed, or a film including a film obtained by coating and curing a dye having absorption anisotropy as a polarizer. Examples of the dye having absorption anisotropy include dichroic dyes. As the dichroic pigment, specifically, iodine or a dichroic organic dye is used. The dichroic organic dye includes a dichroic direct dye composed of a disazo compound such as CI DIRECT RED 39, and a dichroic direct dye composed of a compound such as trisazo and tetrakisazo. The film coated with a dye having absorption anisotropy, which is used as a polarizer, is a stretched film on which a dye having absorption anisotropy is adsorbed, or a composition or a dichroic dye containing liquid crystallinity. Examples thereof include a film having a layer obtained by applying a composition containing a colorant and a polymerizable liquid crystal and curing the composition. A film coated with a dye having absorption anisotropy and cured is preferable because it has no limitation in the bending direction as compared with a stretched film to which a dye having absorption anisotropy is adsorbed.

(Polarizing plate having a stretched film as a polarizer)
A linear polarizing plate provided with a stretched film having a dye having absorption anisotropy adsorbed thereon as a polarizer will be described. The stretched film, which is a polarizer and has a dye having absorption anisotropy adsorbed, is usually a step of uniaxially stretching a polyvinyl alcohol-based resin film, by staining the polyvinyl alcohol-based resin film with a dichroic dye, It is manufactured through a step of adsorbing a dichroic dye, a step of treating the polyvinyl alcohol-based resin film on which the dichroic pigment is adsorbed with an aqueous boric acid solution, and a step of washing with water after the treatment with the aqueous boric acid solution. Such a polarizer may be used as it is as a linear polarizing plate, or one in which a transparent protective film is attached may be used as a linear polarizing plate. The thickness of the thus obtained polarizer is preferably 2 μm to 40 μm.

The polyvinyl alcohol-based resin is obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate resin, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer 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 saponification degree of the polyvinyl alcohol resin is usually about 85 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 can also be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, preferably 1,500 to 5,000.

A film formed from such a polyvinyl alcohol-based resin is used as a raw film for a polarizer. The method for forming a film of the polyvinyl alcohol-based resin is not particularly limited, and the film can be formed by a known method. The film thickness of the polyvinyl alcohol-based raw film can be set to, for example, about 10 μm to 150 μm.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before dyeing with the dichroic dye, simultaneously with dyeing, or after dyeing. When the uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before the boric acid treatment or during the boric acid treatment. It is also possible to carry out uniaxial stretching in these plural stages. In the uniaxial stretching, it may be uniaxially stretched between rolls having different peripheral speeds, or may be uniaxially stretched using a heat roll. The uniaxial stretching may be dry stretching in which stretching is performed in the atmosphere, or wet stretching in which a polyvinyl alcohol-based resin film is swollen with a solvent. The draw ratio is usually about 3 to 8 times.

The thickness of the linearly polarizing plate provided with the stretched film as a polarizer may be, for example, 1 μm or more and 400 μm or less, 5 μm or more, 7 μm or more, and 100 μm or less, It may be 50 μm or less, 20 μm or less, or 10 μm or less. The tensile elastic modulus at a temperature of 25° C. of a linearly polarizing plate provided with a stretched film as a polarizer may be, for example, 1000 MPa or more and 5000 MPa or less.

The material of the protective film to be attached to one side or both sides of the polarizer is not particularly limited, for example, cyclic polyolefin resin film, triacetyl cellulose, cellulose acetate-based resin consisting of diacetyl cellulose. Films known in the art such as resin films, polyester resin films made of resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polycarbonate resin films, (meth)acrylic resin films, polypropylene resin films, etc. Can be mentioned. From the viewpoint of thinning, the thickness of the protective film is usually 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, and usually 5 μm or more, preferably 20 μm or more. .. The protective film may or may not have a retardation.

(Polarizing plate having a film formed of a liquid crystal layer as a polarizer)
A linear polarizing plate including a film formed of a liquid crystal layer as a polarizer will be described. As a film coated with a dye having absorption anisotropy used as a polarizer, a composition containing a dichroic dye having liquid crystallinity, or a composition containing a dichroic dye and a liquid crystal compound is used as a base material. Examples thereof include films obtained by applying and curing. The film may be used as a linear polarizing plate after peeling off the base material or together with the base material, or may be used as a linear polarizing plate having a protective film on one side or both sides thereof. Examples of the protective film include the same one as the linear polarizing plate including the stretched film as a polarizer.

Specific examples of the film obtained by applying the dye having absorption anisotropy include films described in JP2013-37353A and JP2013-33249A.

The film obtained by coating and curing a dye having absorption anisotropy is preferably thin, but if it is too thin, the strength tends to be low and the processability tends to be poor. 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. The thickness of the linear polarizing plate provided with the film formed of the liquid crystal layer as a polarizer may be, for example, 1 μm or more and 50 μm or less, and the temperature of the linear polarizing plate provided with the film formed of the liquid crystal layer as a polarizer is 23° C. The tensile elastic modulus at a humidity of 55% may be, for example, 500 MPa or more and 5000 MPa or less.

(Retardation layer)
The retardation layer 32 may be one layer or two or more layers. Moreover, you may have the overcoat layer which protects the surface of a retardation layer, and the base material film which supports a retardation layer. The retardation layer 32 includes a λ/4 layer, and may further include a λ/2 layer and a positive C layer. When the retardation layer 32 includes a λ/2 layer, a λ/2 layer and a λ/4 layer are sequentially stacked from the linear polarizing plate 31 side. When the retardation layer 32 includes a positive C layer, a λ/4 layer and a positive C layer may be sequentially stacked from the linear polarizing plate 31 side, and the positive C layer and the λ/4 layer may be sequentially stacked from the linear polarizing plate 31 side. You may laminate.

The retardation layer 32 may be formed of the resin film exemplified as the material of the protective film, or may be formed of a layer in which a polymerizable liquid crystal compound is cured. The retardation layer 32 may further include an alignment film or a substrate film, and may have a bonding layer for bonding the λ/4 layer and the λ/2 layer or the positive C layer. .. The laminating layer is a pressure-sensitive adhesive layer or an adhesive layer, and can be formed using the above-mentioned pressure-sensitive adhesive composition or a known adhesive composition. Known adhesive compositions include water-based adhesive compositions such as aqueous polyvinyl alcohol-based resin solutions and water-based two-component urethane-based emulsion adhesives; active energy ray-curable type that cures by irradiation with active energy rays such as ultraviolet rays. An adhesive composition etc. can be mentioned.

The thickness of the retardation layer may be, for example, 1 μm or more and 50 μm or less, and the tensile elastic modulus at a temperature of 23° C. and a relative humidity of 55% of a linear polarizing plate including a film formed of a liquid crystal layer as a polarizer is, for example, 1000 MPa or more. It may be 4000 MPa or less.

(Second adhesive layer)
The second pressure-sensitive adhesive layer 40 is a layer for bonding the circularly polarizing plate 30 and the TS panel 50, and can be formed using a pressure-sensitive adhesive composition. The thickness d of the second pressure-sensitive adhesive layer 40 is not particularly limited as long as it can satisfy the relationships of the above formulas (1) and (2), but is preferably 10 μm or more, more preferably 20 μm or more, It is more preferably 25 μm or more, may be 30 μm or more, and is usually 80 μm or less, preferably 70 μm or less, and more preferably 60 μm or less.

The second adhesive layer 40 has a storage elastic modulus Gd at a temperature of 25° C. and a relative humidity of 50% of preferably 0.01 MPa or more, more preferably 0.05 MPa or more, and 0.07 MPa or more. Is more preferable, it is preferably 0.15 MPa or less, more preferably 0.12 MPa or less, and further preferably 0.1 MPa or less.

When the storage elastic modulus Gd of the second pressure-sensitive adhesive layer 40 decreases, the impact resistance of the flexible laminate 100 tends to decrease, and when the storage elastic modulus Gd of the second adhesive layer 40 increases, the flexibility of the flexible laminate 100 increases. Flexibility tends to decrease. Further, when the storage elastic modulus Gd of the second pressure-sensitive adhesive layer 40 is in the above range, the flexible laminated body 100 satisfies the above formula (1), so that the flexible laminated body 100 excellent in impact resistance is preferably used. Obtainable. Further, when the flexible laminate 100 satisfies the relations of the above formulas (1) and (2), it is possible to preferably obtain the flexible laminate 100 having excellent flexibility and excellent impact resistance.

As the pressure-sensitive adhesive composition forming the second pressure-sensitive adhesive layer 40, those exemplified as the pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer 20 can be used. The pressure-sensitive adhesive composition forming the second pressure-sensitive adhesive layer 40 may be the same as or different from the pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer 20. Further, the formation of the second pressure-sensitive adhesive layer 40 can be performed in the same manner as the formation of the first pressure-sensitive adhesive layer 20.

(Touch sensor panel)
The TS panel 50 is not limited to a detection method as long as it is a sensor that can detect a touched position, and includes a resistance film method, a capacitive coupling method, an optical sensor method, an ultrasonic method, and an electromagnetic inductive coupling method. An example is a surface acoustic wave type TS panel. A resistive film type or capacitive coupling type TS panel is preferably used because of its low cost.

An example of a resistive film type TS panel is a pair of substrates arranged to face each other, an insulating spacer sandwiched between the pair of substrates, and a transparent conductive film provided as a resistive film on the inner front surface of each substrate. It is composed of a film and a touch position detection circuit. In the image display device provided with the resistive film type touch sensor panel, when the surface of the front plate 10 is touched, the opposing resistive films are short-circuited and a current flows through the resistive film. The touch position detection circuit detects the voltage change at this time, and the touched position is detected.

An example of the capacitive coupling type TS panel includes a substrate, a position detection transparent electrode provided on the entire surface of the substrate, and a touch position detection circuit. In the image display device provided with the capacitive coupling type TS panel, when the surface of the front plate 10 is touched, the transparent electrode is grounded via the capacitance of the human body at the touched point. The touch position detection circuit detects the grounding of the transparent electrode, and the touched position is detected.

The TS panel 50 may include only the touch sensor pattern layer, or may include the touch sensor pattern layer and a support layer that supports the touch sensor pattern layer. When the TS panel 50 includes the touch sensor pattern layer and the support layer, the touch panel pattern layer and the support layer may be bonded together by the bonding layer, and the touch sensor pattern layer is formed on the support layer without the bonding layer. May be. The laminating layer is a pressure-sensitive adhesive layer or an adhesive layer, and can be formed using the above-mentioned pressure-sensitive adhesive composition and adhesive composition.

The touch sensor pattern layer included in the TS panel 50 may include a conductive layer such as an electrode and a wiring. The conductive layer is preferably formed so as not to be visually recognized when used in the flexible laminate as the TS panel 50. The touch sensor pattern layer may include a separation layer. The separation layer may be formed on a substrate such as glass, and may be provided to separate the touch sensor pattern layer formed on the separation layer from the substrate together with the separation layer. The separation layer is preferably an inorganic layer or an organic layer. Examples of the material forming the inorganic layer include silicon oxide. As a material for forming the organic material layer, for example, a (meth)acrylic resin composition, an epoxy resin composition, a polyimide resin composition, or the like can be used. The touch sensor pattern layer may further include at least one protective layer. The protective layer can be provided in contact with the conductive layer to support the conductive layer. The protective layer includes at least one of an organic insulating film and an inorganic insulating film, and these films can be formed by a spin coating method, a sputtering method, a vapor deposition method, or the like. The conductive layer may be a transparent conductive layer made of a metal oxide such as ITO, or a metal layer made of a metal such as aluminum, copper, silver or gold. Further, the touch sensor pattern layer may be composed of only conductive layers such as electrodes and wirings. The support layer is preferably a resin film. For example, a cyclic olefin resin film, a polyester resin film such as a polyethylene terephthalate resin film, an acrylic resin film, a triacetyl cellulose resin film, or the like can be used.

The rigidity of the TS panel 50 at a temperature of 23° C. and a relative humidity of 55% is preferably 15 MPa·mm or more, more preferably 50 MPa·mm or more, further preferably 100 MPa·mm or more, and 150 MPa. It is even more preferable that it is 700 MPa·mm or less, more preferably 600 MPa·mm or less, still more preferably 500 MPa·mm or less. As the rigidity of the TS panel 50 decreases, the strength of the flexible laminate 100 tends to decrease, and when the rigidity of the TS panel 50 increases, the flexibility of the flexible laminate 100 tends to decrease. Further, when the rigidity of the TS panel 50 is in the above range, the flexible laminate 100 satisfying the above formula (1) can suitably obtain the flexible laminate 100 having excellent impact resistance. Further, when the flexible laminate 100 satisfies the relations of the above formulas (1) and (2), it is possible to preferably obtain the flexible laminate 100 having excellent flexibility and excellent impact resistance.

The rigidity of the TS panel 50 is obtained by multiplying the tensile elastic modulus Ee [MPa] of the entire TS panel 50 at a temperature of 23° C. and a relative humidity of 55% by the total thickness [mm] of the TS panel 50 (Ee [MPa]×e [μm]. ]×10 ⁻³ ). The thickness e of the TS panel 50 may be, for example, 5 μm or more and 500 μm or less, 5 μm or more and 100 μm or less, or 5 μm or more and 50 μm or less. The tensile elastic modulus Ee of the touch sensor panel may be, for example, 1000 MPa or more and 7000 MPa or less, or may be 1200 MPa or more and 6000 MPa or less.

(Image display device)
FIG. 2 is a schematic cross-sectional view schematically showing an example of the image display device of this embodiment. The image display device 300 includes the flexible laminate 100 including the front plate 10 arranged on the front surface (viewing side) thereof, the display laminate 200 including the display unit, and the bonding layer 60. The display laminated body 200 is laminated on the TS panel 50 side with the bonding layer 60 interposed therebetween. Such an image display device 300 can be a touch panel display device because the flexible laminate 100 includes the TS panel 50.

The image display device 300 may be a flexible display panel. The image display device which is a flexible display may be configured to be foldable with the surface of the front plate 10 inside, or may be configured to be wound with the surface of the front plate 10 inside. Good.

The bonding layer 60 is for bonding the TS panel 50 and the display laminated body 200 in the flexible laminated body 100. When laminating the flexible laminated body 100 and the display laminated body 200, for example, the laminating layer 60 is provided on the TS panel 50 of the flexible laminated body 100, and the display laminated body 200 is laminated on the laminating layer 60. May be. The bonding layer 60 is a pressure-sensitive adhesive layer or an adhesive layer, and can be formed using the pressure-sensitive adhesive composition and the adhesive composition described above.

Examples of the display unit included in the display laminate 200 include a display unit including a display element such as a liquid crystal display element, an organic EL display element, an inorganic EL display element, a plasma display element, and a field emission display element.

The image display device 300 can be used as a mobile device such as a smartphone or a tablet, a television, a digital photo frame, an electronic signboard, a measuring instrument or measuring instrument, an office device, a medical device, a computer device, or the like.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "%" and "parts" in Examples and Comparative Examples are% by mass and parts by mass.

[Measurement of thickness]
The thickness of each layer forming the flexible laminate was measured by the following procedure. The flexible laminate was cut using a laser cutter, and the cross section of the cut flexible laminate was observed using a transmission electron microscope (SU8010, manufactured by Horiba Ltd.), and from the obtained observation image, the flexible laminate was obtained. The thickness of each of the layers was measured.

[Measurement of tensile modulus]
A rectangular small piece having a long side of 110 mm and a short side of 10 mm was cut out from a member forming each layer forming the flexible laminate using a super cutter. Then, with the upper and lower grips of a tensile tester [Autograph AG-Xplus tester manufactured by Shimadzu Corporation], both ends of the measurement sample in the long side direction were sandwiched so that the distance between the grips was 5 cm, and the temperature was 23°C. In an environment with a relative humidity of 55%, the measurement sample is pulled in the length direction of the measurement sample at a pulling speed of 4 mm/min, and the obtained stress-strain curve has a linear slope between 20 and 40 MPa, and a relative temperature of 23° C. The tensile elastic modulus [MPa] at a humidity of 55% was calculated. At this time, the thickness value of each layer measured as described above was used as the thickness for calculating the stress.

[Calculation of rigidity]
The rigidity was calculated by calculating the product of the thickness value and the tensile elastic modulus value measured above.

[Measurement of storage elastic modulus]
Using a rheometer (Anton Parr, MCR-301), a temperature of 25° C. was measured for each measurement sample in which each pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer or second pressure-sensitive adhesive layer) was stacked to a thickness of 150 μm. The storage elastic modulus (Gb, Gd) was measured under the conditions of humidity 50%, stress 1% and frequency 1 Hz.

[Impact resistance test]
A touch sensor of a flexible laminate obtained in each of Examples and Comparative Examples by using an optical adhesive sheet (8146-04, manufactured by 3M) having a thickness of 100 μm on glass (Soda Glass 1.1T, manufactured by JMC Glass). The panel side was fixed and the sample for evaluation was prepared. This evaluation sample was placed in an impact resistance tester (Drop Tester, manufactured by TAEWON TECH CO.) so that the front plate side was facing up, and then the test was performed from a position 5 cm above the surface of the evaluation panel on the front plate side. An impact resistance test was conducted at a temperature of 25° C. in which the sphere was allowed to fall freely and collide with the evaluation sample. This impact resistance test was performed while changing the weight of the test sphere, and the weight of the test sphere when the glass under the evaluation sample was broken was determined. The weight of the test ball when the glass of the evaluation sample was broken,
A is 100 g or more,
If the amount is 50 g or more and less than 100 g, B,
C when less than 50 g,
As a result, the impact resistance was evaluated.

[Flexibility test]
A flexibility test was conducted at a temperature of 25° C. according to the following procedure. A flexible tester (CFT-720C, manufactured by Covotech) was installed with the flexible laminates obtained in each Example and Comparative Example in a flat state (non-bent state) so that the front plate side was the inner side. After bending the flexible laminate so that the distance between the front plates facing each other when bent was 4.0 mm, a bending operation was performed to restore the original flat state. When this bending operation was performed once, the number of times of bending was counted as one, and this bending operation was repeated. The number of times of bending when cracks and floating of the pressure-sensitive adhesive layer occurred in the region bent by the bending operation was confirmed as the limit number of times of bending. The occurrence of cracks and floating of the pressure-sensitive adhesive layer in the bent area due to the bending operation,
A when the number of bends reaches 200,000 times and is not seen,
When the number of flexing times is 100,000 or more and less than 200,000, it is B,
When the number of flexing is 50,000 times or more and less than 100,000 times, C,
D when the number of bends is less than 50,000,
As a result, the flexibility test was evaluated.

[Example 1]
(Preparation of front plate)
As the front plate, a resin film with a hard coat layer having a thickness of 50 μm in which hard coat layers were formed on both sides of the resin film was prepared. The resin film was a polyimide resin film having a thickness of 30 μm, and each of the hard coat layers had a thickness of 10 μm and was a layer formed from a composition containing a dendrimer compound having a polyfunctional acrylic group at the terminal.

(Preparation of first adhesive layer)
The acrylic pressure-sensitive adhesive composition was applied onto the release film and dried to prepare a first pressure-sensitive adhesive layer with a release film on which a first pressure-sensitive adhesive layer was formed. The thickness of the first pressure-sensitive adhesive layer was 50 μm, and the storage elastic modulus Gb at a temperature of 25° C. and a relative humidity of 50% was 0.09 MPa.

(Preparation of circularly polarizing plate)
After forming a photo-alignment film on the substrate, a composition containing a dichroic dye and a polymerizable liquid crystal compound is applied to the substrate, aligned and cured to form a polarizer having a thickness of 2.5 μm (temperature 23° C., relative Tensile elastic modulus at humidity 55%: 937 MPa) was obtained. A 25 μm-thick triacetyl cellulose (TAC) film (manufactured by Konica Minolta Co., Ltd., temperature 23° C., tensile elastic modulus at relative humidity 55%: 3282 MPa) as a protective film is pasted onto this polarizer via an adhesive layer. After combining, the base material was peeled off to obtain a linear polarizing plate.

The λ/4 layer side of the retardation layer, which will be described later, was attached to the surface of the linear polarizing plate obtained by peeling the base material to obtain a circularly polarizing plate. The retardation layer had a thickness of 14 μm and had a layer structure in which a pressure-sensitive adhesive layer, a λ/4 layer, a pressure-sensitive adhesive layer, and a positive C layer were laminated in this order. Each adhesive layer had a thickness of 5 μm and a storage elastic modulus of 0.6 MPa at a temperature of 25° C. and a relative humidity of 50%. The λ/4 layer had a layer in which a liquid crystal compound was cured and an alignment film, and had a thickness of 3 μm. The positive C layer had a layer in which a liquid crystal compound was cured and an alignment film, and had a thickness of 1 μm.

(Preparation of second adhesive layer)
An acrylic pressure-sensitive adhesive composition was applied onto the release film and dried to prepare a second pressure-sensitive adhesive layer with a release film on which a second pressure-sensitive adhesive layer was formed. The thickness of the second pressure-sensitive adhesive layer was 10 μm, and the storage elastic modulus Gd at a temperature of 25° C. and a relative humidity of 50% was 0.1 MPa.

(Preparation of touch sensor panel (1))
A touch sensor pattern layer was prepared as a TS panel (1). The touch sensor pattern layer includes an ITO layer as a transparent conductive layer and a cured layer of an acrylic resin composition as a separation layer, has a thickness of 7 μm, and has a tensile strength at a temperature of 23° C. and a relative humidity of 55%. The elastic modulus was 4510 MPa. The rigidity of the TS panel (1) was 31.6 MPa·mm.

(Preparation of flexible laminate)
Corona treatment was performed on one surface of the front plate and the surface of the first adhesive layer with the release film on the first adhesive layer side, and the corona-treated surfaces were bonded together. Next, the surface exposed by peeling off the release film adhered to the first pressure-sensitive adhesive layer and the surface of the circularly polarizing plate on the side of the linear polarizing plate are subjected to corona treatment, and the corona-treated surfaces are bonded together. Thus, a composite of the front plate and the circularly polarizing plate was obtained. Subsequently, corona treatment was performed on the surface of the composite on the positive C layer side and the surface of the second adhesive layer with release film on the second adhesive layer side, and the corona treated surfaces were bonded together. Next, the release film adhered to the second pressure-sensitive adhesive layer is peeled off, and the exposed surface is subjected to corona treatment, and the corona-treated surface and the transparent conductive layer side of the TS panel (1) are bonded together to form a flexible laminate. Got the body The corona treatments performed above were performed at a frequency of 20 kHz, a voltage of 8.6 kV, a power of 2.5 kW, and a speed of 6 m/min.

The obtained flexible laminate has a total thickness t [μm] of the front plate 10, the first pressure-sensitive adhesive layer 20, the circularly polarizing plate 30, the second pressure-sensitive adhesive layer 40, and the TS panel 50 (represented by the above formula (3). The thickness) was 158.5 μm and the length was 177 mm×width 105 mm. An impact resistance test and a bending test were performed on the flexible laminate. The results are shown in Table 1.

[Example 2]
A flexible laminate was prepared by the same procedure as in Example 1 except that the first adhesive layer and the second adhesive layer having the thickness and the storage elastic modulus at a temperature of 25° C. shown in Table 1 were used. .. An impact resistance test and a bending test were performed on the obtained flexible laminate. The results are shown in Table 1.

[Example 3]
(Preparation of touch sensor panel (2))
The TS panel (2) was prepared by stacking a touch sensor pattern layer, an adhesive layer, and a support layer in this order. The touch sensor pattern layer includes an ITO layer as a transparent conductive layer and a cured layer of an acrylic resin composition as a separation layer, has a thickness of 7 μm, and has a tensile strength at a temperature of 23° C. and a relative humidity of 55%. The elastic modulus was 4510 MPa. The adhesive layer is provided on the separation layer side of the touch sensor pattern layer, has a thickness of 3 μm, a tensile elastic modulus of 12309 MPa at a temperature of 23° C. and a relative humidity of 55%, and the support layer has a thickness of 13 μm. It was a cyclic polyolefin (COP) resin film having a tensile elastic modulus of 1785 MPa at a temperature of 23° C. and a relative humidity of 55%. The rigidity of the TS panel (2) was 42.6 MPa·mm.

(Preparation of flexible laminate)
As the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer, those having a thickness and a storage elastic modulus at a temperature of 25° C. shown in Table 1 were used, except that the TS panel (2) was used instead of the TS panel (1). Produced a flexible laminate in the same manner as in Example 1. An impact resistance test and a bending test were performed on the obtained flexible laminate. The results are shown in Table 1.

[Examples 4 and 5]
A flexible laminate was prepared by the same procedure as in Example 1 except that the first adhesive layer and the second adhesive layer having the thickness and the storage elastic modulus at a temperature of 25° C. shown in Table 1 were used. .. An impact resistance test and a bending test were performed on the obtained flexible laminate. The results are shown in Table 1.

[Example 6, Comparative Example 1]
(Preparation of touch sensor panel (3))
As the support layer, a procedure similar to that of the TS panel (2) except that a cyclic polyolefin (COP) resin film having a thickness of 23 μm and a tensile modulus of elasticity of 1628 MPa at a temperature of 23° C. and a relative humidity of 55% was used. Then, a TS panel (3) was prepared. The rigidity of the TS panel (3) was 53.7 MPa·mm.

[Examples 7 and 8]
A flexible laminate was prepared by the same procedure as in Example 1 except that the first adhesive layer and the second adhesive layer having the thickness and the storage elastic modulus at a temperature of 25° C. shown in Table 1 were used. .. An impact resistance test and a bending test were performed on the obtained flexible laminate. The results are shown in Table 1.

(Preparation of flexible laminate)
As the first adhesive layer and the second adhesive layer, those having the thickness and the storage elastic modulus at a temperature of 25° C. described in Table 1 were used, and the TS panel (3) was used instead of the TS panel (1). Produced a flexible laminate in the same manner as in Example 1. An impact resistance test and a bending test were performed on the obtained flexible laminate. The results are shown in Table 1.

10 front plate, 20 first adhesive layer, 30 circularly polarizing plate, 31 linearly polarizing plate, 32 retardation layer, 40 second adhesive layer, 50 touch sensor panel, 60 bonding layer, 100 flexible laminate, 200 display Laminate, 300 image display device.

Claims (11)

A flexible laminate including a front plate, a first adhesive layer, a circularly polarizing plate, a second adhesive layer, and a touch sensor panel in this order,
The thickness of the front plate is a [μm], the thickness of the first pressure-sensitive adhesive layer is b [μm], the thickness of the circularly polarizing plate is c [μm], and the thickness of the second pressure-sensitive adhesive layer is d [μm]. , And the thickness of the touch sensor panel is e [μm], the following formula (1):
(B+d)/(a+b+c+d+e)≧ 0.34 (1)
Meet the relationship,
A flexible laminate in which the thickness a of the front plate is 30 μm or more . The thickness b of the first pressure-sensitive adhesive layer and the thickness d of the second pressure-sensitive adhesive layer are represented by the following formula (2):
1≦b/d≦6 (2)
The flexible laminate according to claim 1, which satisfies the relationship. The flexible laminate according to claim 1, wherein the thickness b of the first pressure-sensitive adhesive layer is larger than the thickness d of the second pressure-sensitive adhesive layer. The thickness b of the first pressure-sensitive adhesive layer is 10 μm or more,
The thickness d of the said 2nd adhesive layer is 10 micrometers or more, The flexible laminated body of any one of Claims 1-3. The rigidity of the front plate at a temperature of 23° C. and a relative humidity of 55% is 90 MPa·mm or more and 700 MPa·mm or less,
The rigidity of the circularly polarizing plate at a temperature of 23° C. and a relative humidity of 55% is 40 MPa·mm or more and 400 MPa·mm or less,
The flexible laminate according to claim 1, wherein the touch sensor panel has a rigidity at a temperature of 23° C. and a relative humidity of 55% of 15 MPa·mm or more and 700 MPa·mm or less. The storage elastic modulus of the first pressure-sensitive adhesive layer at a temperature of 25° C. and a relative humidity of 50% is 0.01 MPa or more and 0.15 MPa or less,
The flexible laminate according to any one of claims 1 to 5, wherein a storage elastic modulus of the second pressure-sensitive adhesive layer at a temperature of 25°C and a relative humidity of 50% is 0.01 MPa or more and 0.15 MPa or less. The total thickness t [μm] of the thickness a of the front plate, the thickness b of the first adhesive layer, the thickness c of the circularly polarizing plate, the thickness d of the second adhesive layer, and the thickness e of the touch sensor panel. Is expressed by the following formula (3):
t=a+b+c+d+e (3)
The flexible laminate according to any one of claims 1 to 6, wherein t is 250 µm or less. The flexible laminate according to claim 1, wherein the front plate is a resin film or a resin film with a hard coat layer having a hard coat layer on at least one surface of the resin film. The flexible laminate according to any one of claims 1 to 8, wherein the flexible laminate has a limit number of bends of 50,000 times or more in a bendability test. The circularly polarizing plate includes, in order from the first pressure-sensitive adhesive layer side, a linear polarizing plate and a retardation layer,
The said linear polarizing plate is a flexible laminated body of any one of Claims 1-9 which contains a protective film and a polarizer in order from the said 1st adhesive layer side. Comprising a flexible laminate according to any one of claims 1 to 10, wherein the front plate is disposed in front, the image display device.

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