KR20200081288A - Flexible laminate and image display device having the same - Google Patents

Abstract

Provided are a flexible laminate having impact resistance and excellent flexibility and an image display device having the same. The flexible laminate includes a front plate, a first adhesive layer, a circularly polarizing plate, a second adhesive layer, and a touch sensor panel in this order. The following formula (i) {Ea × (a + b)} / (a + b + c + d + e) >= 1.5 is satisfied, wherein the thickness of the front plate is a [μm], the thickness of the first adhesive layer is b [μm], the thickness of the circularly polarizing plate is c [μm], the thickness of the second adhesive layer is d [μm], the thickness of the touch sensor panel is e [μm], the tensile modulus of the front plate is Ea [GPa] at 23°C and relative humidity of 55%.

Description

Flexible laminate and an image display device having the same {FLEXIBLE LAMINATE AND IMAGE DISPLAY DEVICE HAVING THE SAME}

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

In the field of various image display devices, such as a liquid crystal display device and an organic electroluminescence (EL) display device, a flexible display is known that enables folding or the like of a display panel using a flexible substrate (for example, Patent Document 1). , 2).

Patent Document 1: Publication of Korean Patent Publication No. 10-2016-0053788 Patent Document 2: Publication of Korean Patent Publication No. 10-2017-0093610

The flexible substrate has excellent flexibility, but tends to have poor impact resistance compared to glass used in conventional image display devices. On the other hand, if it is desired to improve the impact resistance of a flexible substrate, the flexible properties tend to decrease.

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

The present invention provides the following flexible laminate and image display device.

[1] A flexible laminate comprising a front plate, a first adhesive layer, a circular 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 adhesive layer is b [µm], the thickness of the circular polarizing plate is c [µm], the thickness of the second adhesive layer is d [µm] and the touch When the thickness of the sensor panel is e[µm], the tensile modulus at the temperature of 23°C of the front panel and the relative humidity of 55% is Ea[GPa], the following formula (i):

{Ea×(a+b)}/(a+b+c+d+e)≥1.5 (i)

Flexible laminate that satisfies the relationship of

[2] The tensile modulus Ea [GPa] of the front plate, 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 (ii):

b/(Ea×d)≥0.3 (ii)

The flexible laminate according to [1], which satisfies the relationship of

[3] The stiffness at the temperature of 23° C. and the relative humidity of 55% of the front plate is 0.09 GPa·mm or more and 0.7 GPa·mm or less,

The circular polarizing plate has a rigidity at a temperature of 23° C. and a relative humidity of 55% of 40 MPa·mm or more and 400 MPa·mm or less,

The flexible laminate according to [1] or [2], wherein the stiffness at the temperature of the touch sensor panel at 23°C and the relative humidity of 55% is 15 MPa·mm or more and 700 MPa·mm or less.

[4] The storage elastic modulus at a temperature of 25°C and a relative humidity of 50% of the first adhesive layer is 0.01 MPa or more and 0.15 MPa or less,

The flexible laminate according to any one of [1] to [3], wherein a storage elastic modulus at a temperature of 25°C and a relative humidity of 50% of the second pressure-sensitive adhesive layer is 0.01 MPa or more and 0.15 MPa or less.

[5] 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 circular polarizing plate, the thickness d of the second adhesive layer, and the thickness e of the touch sensor panel , The following formula (iii):

t=a+b+c+d+e (iii)

When represented by, t is the flexible laminate according to any one of [1] to [4], which is 250 µm or less.

[6] The flexible laminate according to any one of [1] to [5], wherein the front plate is a resin film or a resin film having a hard coat layer having a hard coat layer on at least one surface of the resin film.

[7] The flexible laminate according to any one of [1] to [6], wherein the number of times of limit bending in a flexural test in which the front plate side is bent toward the inside is 50,000 or more.

[8] The flexible laminate according to any one of [1] to [7], in which the number of times of limit bending in the flexibility test in which the front plate side is bent to the outside is 50,000 or more.

[9] An image display device comprising the flexible laminate according to any one of [1] to [8], wherein the front plate is disposed on the front surface.

ADVANTAGE OF THE INVENTION According to this invention, the flexible laminated body which has impact resistance, but is excellent in bending property, and the image display apparatus provided with it can be provided.

1 is a schematic cross-sectional view schematically showing an example of the flexible laminate of the present invention.
2 is a schematic cross-sectional view schematically showing an example of the image display device of the present invention.

Hereinafter, although embodiment of this invention is described, referring drawings, this invention is not limited to the following embodiment. In all of the following drawings, the scales are appropriately adjusted in order to make each component easy to understand, and the scales of the components shown in the drawings and the scales of the actual components do not necessarily match.

(Flexible laminate)

1 is a schematic cross-sectional view schematically showing an example of the flexible laminate of the present embodiment. The flexible laminate 100 may be referred to as a front panel 10, a first adhesive layer 20, a circular polarizing plate 30, a second adhesive layer 40, and a touch sensor panel (hereinafter referred to as "TS panel"). (50). The flexible laminate 100 is, as shown in Figure 1, from the viewer side, the front plate 10, the first pressure-sensitive adhesive layer 20, the circular polarizing plate 30, the second pressure-sensitive adhesive layer 40 and the TS panel 50 are stacked in this order.

The flexible laminate 100 has flexibility, and accordingly, it can be applied to an image display device (flexible display) capable of folding or winding. The flexible laminate 100 of the present embodiment is particularly excellent in flexibility (hereinafter sometimes referred to as "flexibility (in)") to bend with the front plate 10 side inward. Specifically, the flexible laminate 100 has a limiting number of times of bending, which is a limit of number of times of bending, which is the number of times of bending of cracks or pressure-sensitive adhesive layers in a bent region, in a flexural (in) test in Examples described later. It is possible to have, the number of times of limit bending is preferably 100,000 times or more, more preferably 200,000 times or more.

In addition, in one embodiment of the flexible laminate 100, in addition to the above-mentioned flexibility (in), the front plate 10 side may be bent to the outside (hereinafter referred to as “flexibility (out)”). .) can also be made excellent. Specifically, the flexible laminate 100 is preferably in the flexural (out) test in Examples to be described later, having a flexural property of a limit of 50,000 or more, and more preferably a limit of flexion of 100,000 or more. And more preferably 200,000 times or more.

The flexible laminate 100 can constitute an image display device as described above, and can be suitably used for a flexible display capable of folding or winding. In addition, since the flexible laminate 100 includes a circular polarizing plate 30, it can also be used as an antireflection film in, for example, an organic electroluminescence (EL) display device.

Flexible laminate 100, the thickness of the front plate 10 a [㎛], the thickness of the first pressure-sensitive adhesive layer 20 b [㎛], the thickness of the circular polarizing plate 30 c [㎛], the 2 The thickness of the pressure-sensitive adhesive layer 40 is set to d[µm], the thickness of the TS panel 50 is e[µm], the temperature of the front plate is 23°C, and the tensile modulus at 55% relative humidity is Ea[GPa]. When, the following formula (i):

{Ea×(a+b)}/(a+b+c+d+e)≥1.5 (i)

Satisfies the relationship. Hereinafter, the total thickness t [µm] of the front plate 10, the first adhesive layer 20, the circular polarizing plate 30, the second adhesive layer 40, and the TS panel 50 is expressed by the following formula (iii). :

t=a+b+c+d+e (iii)

It may be represented by.

In the formula (i), {Ea×(a+b)}/t(b+d)/t (where t is represented by the formula (iii)) is preferably 1.65 or more, more preferably 1.70 or more Preferably, it may be 2.00 or more, 2.50 or more, and usually 6.00 or less, 5.50 or less, 5.00 or less, or 4.50 or less.

The flexible laminate 100 is provided on the image display device such that the front plate 10 side is the front side (viewing side). Therefore, from the viewpoint of the impact resistance of the flexible laminate 100, it is preferable that the thickness a of the front plate 10 and the thickness b of the first pressure-sensitive adhesive layer 20 positioned on the front side of the image display device are large. In addition, from the viewpoint of the impact resistance of the flexible laminate 100, it is preferable that the tensile modulus Ea of the front plate 10 is also large. On the other hand, from the viewpoint of the flexibility of the flexible laminate 100, the smaller the total thickness t represented by the formula (iii), the smaller. Therefore, in order to achieve both impact resistance and flexibility in the flexible laminate 100, in {Ea×(a+b)}/t of the formula (i), it is considered that the denominator can be made small and the molecule can be made large. .

When the flexible laminate 100 satisfies the relationship of the formula (i) above, a good impact resistance is obtained, and in particular, the flexible laminate excellent in bending property (in) for bending the front plate 10 side inward. (100).

Although the total thickness t represented by the above formula (iii) is not particularly limited, in recent years, image display devices have been made thinner and lighter in weight, and members used in the image display devices tend to require thinner and lighter weight, and are flexible laminated. The sieve 100 is also required to have a small thickness. Therefore, the flexible laminate 100 is also required to support thinning, and the thickness is preferably 250 µm or less, more preferably 220 µm or less, 200 µm or less, or 180 µm or less, It may be 150 µm or less, usually 40 µm or more, and 70 µm or more.

The flexible laminate 100 has the following formula (iv):

(b+d)/t≥0.5 (iv)

It is preferable to satisfy. (B+d)/t in the formula (iv) is more preferably 0.5 or more, more preferably 0.6 or more, and may be 0.65 or more, usually 0.9 or less, or 0.8 or less. When the flexible laminate 100 satisfies the relationship of formula (iv), in the flexible laminate 100, the first pressure-sensitive adhesive layer 20 and the second pressure-sensitive adhesive layer 40 can be formed with a thickness equal to or greater than a predetermined value. . Thereby, while ensuring the flexibility of the flexible laminated body 100, the shock absorption of the whole flexible laminated body 100 can be improved and the impact resistance can be improved.

In the flexible laminate 100, the tensile modulus Ea of the front plate 10, the thickness b of the first pressure-sensitive adhesive layer 20, and the thickness d of the second pressure-sensitive adhesive layer 40 are represented by the following formula (ii):

b/(Ea×d)≥0.3 (ii)

It is desirable to satisfy the relationship. The b/(Ea×d) in the formula (ii) is preferably 0.40 or more, more preferably 0.50 or more, and is usually 3.0 or less, preferably 2.5 or less, more preferably 2.0 or less, and may be 1.8 or less. .

The flexible laminate 100 is flexible. From the viewpoint of providing good flexibility (in) and flexibility (out) to the flexible laminate 100, it is preferable that the thickness d of the second pressure-sensitive adhesive layer 40 is small (that is, b/d is large). In addition, when the shear stress at the time of bending the flexible laminate 100 becomes small, it becomes easy to flex the flexible laminate 100. Therefore, it is preferable that the tensile modulus Ea of the front plate 10 is small (that is, 1/Ea is large). Therefore, in order to make the flexibility (in) and the bendability (out) good in the flexible laminate 100, it is good to make the denominator small and the molecule large in b/(Ea×d) of the formula (ii). I think.

Since the flexible laminate 100 satisfies the relationship of the above formula (ii), in particular, in addition to the above-described flexibility (in), it can be said to be excellent in the flexibility (out) that is bent toward the outside of the front plate 10 side. have.

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 represented by the following formula (v):

0.5≤b/d≤7 (v)

It is desirable to satisfy the relationship. Since the thickness b of the first pressure-sensitive adhesive layer 20 is preferably larger than the thickness d of the second pressure-sensitive adhesive layer 40, b/d in the formula (v) is more preferably 1 or more, and more preferably 1.5 or more. And may be 2 or more, or 3 or more. Moreover, it is preferable that b/d in said Formula (v) is 6 or less, it is more preferable that it is 5.5 or less, and 5 or less may be sufficient. Since the thickness b of the first pressure-sensitive adhesive layer 20 and the thickness d of the second pressure-sensitive adhesive layer 40 are in the relationship of the formula (v), in particular, the flexibility to bend the front plate 10 side inwardly An excellent flexible laminate 100 can be obtained.

The shape of the flexible laminate 100 is not particularly limited in the plane direction, but 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, and may be 100 mm to 280 mm, and the length of the short side is preferably 30 mm to 250 mm, for example, 60 mm to 220 mm may be sufficient. The flexible laminate 100 may be a rounded rectangular shape in which R processing is performed on at least one of the corners of the rectangular shape, or may be a rectangular shape having a cutout on at least one side. In addition, a hole portion penetrating in the lamination direction may be formed in the flexible laminate 100.

(Front panel)

The front plate 10 can function as a layer for protecting a display element or the like of the image display device, and is a plate-shaped body that can transmit light, and the plate-shaped body is usually made of glass or resin. The front plate 10 may be disposed on the outermost surface of the image display device. It is preferable that the front plate 10 is a resin film or a resin film with a hard coat layer, which further improves hardness by forming a hard coat layer on at least one surface of the resin film. In addition, the front plate 10 may have a blue light cut function, a viewing angle adjustment function, or 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, Polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl (meth And films formed of polymers such as acrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, and polyamideimide. These polymers may be used alone or in combination of two or more. When the image display device 300 is a flexible display, a resin film formed of a polymer such as polyimide, polyamide, polyamide imide, which has excellent flexibility and can be configured to have high strength and high transparency is suitably Is used.

The resin film provided with the hard coat layer constituting 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 a hard coat layer is provided on both surfaces of the resin film, 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 property compared with the resin film which does not have a 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; Polyester resins; Urethane-based resins; Amide resins; And epoxy-based resins. The hard coat layer may contain additives in order to improve the strength. The additive is not limited, and examples include inorganic fine particles, organic fine particles, or mixtures thereof.

The front plate 10 preferably has a rigidity at a temperature of 23° C. and a relative humidity of 55% of 0.090 GPa·mm or more, more preferably 0.12 GPa·mm or more, still more preferably 0.2 GPa·mm or more, and 0.25 It is more preferable that it is GPa*mm or more, and it is preferable that it is 0.7 GPa*mm or less, it may be 0.6 GPa*mm or less, and it may be 0.5 GPa*mm or less. When the rigidity of the front plate 10 decreases, the flexibility of the flexible laminate 100 improves, while the impact resistance tends to decrease, and when the rigidity of the front plate 10 increases, the flexibility of the flexible laminate 100 increases. While the impact resistance is improved, the flexibility tends to decrease. In addition, when the rigidity of the front plate 10 is within the above-mentioned range, the flexible laminate 100 satisfies the relationship of the formula (i) or the formulas (i) and (ii), thereby It is possible to suitably obtain the flexible laminate 100 having impact properties and excellent flexibility.

The stiffness of the front plate 10 is the product of the tensile modulus Ea[GPa] at a temperature of 23°C and a relative humidity of 55% of the entire front plate 10 and the thickness [mm] of the entire front plate 10 (Ea[ GPa] × a [µm] × 10 ^-3 ). The thickness a of the front plate 10 may be, for example, 30 μm or more and 200 μm or less, preferably 50 μm or more and 150 μm or less, more preferably 50 μm or more and 100 μm or less, or 90 μm or less. The tensile modulus Ea of the front plate 10 is, for example, preferably 1 GPa or more, more preferably 2 GPa or more, still more preferably 3 GPa or more, and further preferably 30 GPa or less, and more preferably 20 GPa or less. And more preferably 10 GPa or less.

(First adhesive layer)

The first adhesive layer 20 is a layer for bonding the front plate 10 and the circular polarizing plate 30, and can be formed using an adhesive composition. The thickness b of the first pressure-sensitive adhesive layer 20 is not particularly limited as long as the relationship between the above formulas (i) and (ii) can be satisfied, but is preferably 5 μm or more, more preferably 7 μm or more, and 10 It is more preferable that it is 20 micrometers or more, may be 20 micrometers or more, may be 30 micrometers or more, and is usually 200 micrometers or less, preferably 100 micrometers or less, and more preferably 80 micrometers or less.

The first pressure-sensitive adhesive layer 20 preferably has a storage elastic modulus Gb at a temperature of 25°C and a relative humidity of 50% of 0.005 MPa or more, preferably of 0.007 MPa or more, of 0.01 MPa or more, and of preferably 0.2 MPa or less. It may be 0.17 MPa or less, or may be 0.15 MPa or less.

When the storage elastic modulus Gb of the first adhesive layer 20 decreases, the impact resistance of the flexible laminate 100 tends to decrease, and when the storage elastic modulus Gb of the first adhesive layer 20 increases, the flexible laminate 100 ) Has a tendency to decrease the flexibility. In addition, when the storage elastic modulus Gb of the first pressure-sensitive adhesive layer 20 is in the above-described range, the flexible laminate 100 has the relationship between the formula (i) or the formulas (i) and (ii). By being satisfactory, the flexible laminate 100 having impact resistance and excellent flexibility can be suitably obtained.

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

Examples of the (meth)acrylic resin (base polymer) used in the pressure-sensitive adhesive composition include (meth)acrylic acid such as butyl (meth)acrylate, ethyl (meth)acrylate, isooctyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Polymers or copolymers using one or two or more of the esters as monomers are suitably used. It is preferable to copolymerize a polar monomer to the base polymer. Examples of the polar monomers include (meth)acrylic acid, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid hydroxyethyl, (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylate, and glycidyl And monomers having a carboxyl group, hydroxyl group, amide group, amino group, or epoxy group, such as (meth)acrylate.

The pressure-sensitive adhesive composition may contain only the base polymer, but usually contains a crosslinking agent. As a crosslinking agent, it is a bivalent or more metal ion, and forms a carboxylate metal salt between carboxyl groups; A polyamine compound, which forms an amide bond between carboxyl groups; A polyepoxy compound or polyol, which forms an ester bond between carboxyl groups; As a polyisocyanate compound, what forms an amide bond between carboxyl groups is illustrated. Especially, a polyisocyanate compound is preferable.

The active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by irradiation with active energy rays such as ultraviolet rays or electron beams, and can be adhered to adherends such as films with adhesiveness even before irradiation with active energy rays. It is a pressure-sensitive adhesive composition having properties that can be cured to adjust the adhesion. It is preferable that the active energy ray-curable pressure-sensitive adhesive composition is an ultraviolet curable type. 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. In addition, a photopolymerization initiator, a photosensitizer, or the like may be added as necessary.

The pressure-sensitive adhesive composition includes fine particles, beads (resin beads, glass beads, etc.) for imparting light scattering properties, glass fibers, resins other than the base polymer, tackifiers, fillers (metal powder or other inorganic powder, etc.), antioxidants, Additives such as ultraviolet absorbers, dyes, pigments, colorants, antifoaming agents, corrosion inhibitors, and photopolymerization initiators may be included.

The first pressure-sensitive adhesive layer 20 can be formed by applying an organic solvent dilution of the pressure-sensitive adhesive composition onto a substrate and drying it.

(Circular polarizer)

The circular polarizing plate 30 may have 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 a second adhesive It can be arranged on the layer 40 side. The circularly polarizing plate 30 can convert light emitted from the display element side of the image display device having the flexible laminate 100 through the flexible laminate 100 into circularly polarized light. In addition, since the circularly polarizing plate 30 can suppress the emission of reflected light of external light, the flexible laminate 100 can be provided with a function as an antireflection film.

The circular polarizing plate 30 preferably has a stiffness of 40 MPa·mm or more at a temperature of 23° C. and a relative humidity of 55%, and may be 80 MPa·mm or more, 100 MPa·mm or more, and 700 MPa· It is preferably mm or less, may be 600 MPa·mm or less, 500 MPa·mm or less, 400 MPa·mm or less, 200 MPa·mm or less, or 100 MPa·mm or less. When the rigidity of the circularly polarizing plate 30 decreases, the flexibility of the flexible laminate 100 improves, while the impact resistance tends to decrease, and when the rigidity of the circularly polarizing plate 30 increases, when the rigidity of the circularly polarizing plate 30 increases, While the impact resistance is improved, the flexibility tends to decrease. In addition, when the rigidity of the circularly polarizing plate 30 is within the above-mentioned range, the flexible laminate 100 satisfies the relationship between the formula (i) or the formulas (i) and (ii). It is possible to suitably obtain the flexible laminate 100 having impact properties and excellent flexibility.

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

(Straight polarizing plate)

The linearly polarizing plate 31 has a function of selectively transmitting linearly polarized light in one direction from non-polarized light such as natural light. Examples of the linearly polarizing plate 31 include a stretched film obtained by adsorbing a dye having absorption anisotropy, or a film including a film cured by applying a dye having absorption anisotropy as a polarizer. Examples of the dye having anisotropy of absorption include a dichroic dye. As a dichroic dye, iodine or an organic dye of dichroism is specifically used. For the dichroic organic dye, C.I. Dichroic direct dyes containing diazo compounds such as DIRECT RED 39, and dichroic direct dyes containing compounds such as tris azo and tetrakis azo are included. As a film coated with a dye having absorption anisotropy, which is used as a polarizer, a stretched film in which a dye having absorption anisotropy is adsorbed, or a composition comprising a dichroic dye having liquid crystallinity or a composition comprising a dichroic dye and a polymerizable liquid crystal And a film having a layer obtained by applying and curing the composition. A film cured by applying a dye having absorption anisotropy is preferable because there is no restriction in the bending direction compared to a stretched film adsorbing a dye having absorption anisotropy.

(Polarizing plate provided with a stretched film as a polarizer)

A linear polarizing plate comprising a stretched film adsorbing a dye having absorption anisotropy as a polarizer will be described. The stretched film which adsorbed the dye having absorption anisotropy, which is a polarizer, is usually a step of uniaxially stretching a polyvinyl alcohol-based resin film, a process of adsorbing the dichroic dye by dyeing the polyvinyl alcohol-based resin film with a dichroic dye, and It has a process of treating a polyvinyl alcohol-based resin film adsorbed with a dichroic dye with an aqueous solution of boric acid, and is produced through a process of washing with water after treatment with an aqueous solution of boric acid. Such a polarizer may be used as a straight polarizing plate as it is, or a transparent protective film bonded to one or both surfaces thereof may be used as a straight polarizing plate. The thickness of the polarizer thus obtained 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-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. Other monomers copolymerizable with vinyl acetate include, for example, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, (meth)acrylamides having an ammonium group, and the like.

The saponification degree of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may 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 of such a polyvinyl alcohol-based resin is used as a raw film for a polarizer. The method for forming the polyvinyl alcohol-based resin is not particularly limited, and can be formed by a known method. The film thickness of the polyvinyl alcohol-based fabric film can be, for example, about 10 μm to 150 μm.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after dyeing with a dichroic dye. When uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before boric acid treatment or may be performed during boric acid treatment. Moreover, it is also possible to uniaxially stretch in these multiple steps. In the uniaxial stretching, uniaxial stretching may be performed between rolls having different circumferential speeds, or uniaxial stretching may be performed using a hot roll. Further, the uniaxial stretching may be dry stretching in which stretching is performed in the air, or wet stretching in which a polyvinyl alcohol-based resin film is swelled using a solvent to perform stretching. The draw ratio is usually about 3 to 8 times.

The thickness of the linear polarizing plate provided with the stretched film as a polarizer may be, for example, 1 µm or more and 100 µm or less, 5 µm or more, 7 µm or more, or 700 µm or less, or 50 µm or less, 20 It may be less than or equal to µm, or less than or equal to 10 µm. The tensile elastic modulus at a temperature of 25°C of a linear polarizing plate provided with a stretched film as a polarizer may be, for example, 1 GPa or more and 20 GPa or less.

The material of the protective film bonded to one side or both sides of the polarizer is not particularly limited, but, for example, a cellulose acetate-based resin film containing a resin such as a cyclic polyolefin-based resin film, triacetyl cellulose, diacetyl cellulose, polyethylene terephthalate, And films known in the art, such as polyester-based resin films, polycarbonate-based resin films, (meth)acrylic-based resin films, and polypropylene-based resin films, including resins such as polyethylene naphthalate and polybutylene terephthalate. have. 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 further preferably 5 µm or more and 20 µm or more. The protective film may or may not have a phase difference.

(Polarizing plate provided with a film formed of a liquid crystal layer as a polarizer)

A linear polarizing plate comprising a film formed of a liquid crystal layer as a polarizer will be described. As a film coated with a dye having absorption anisotropy, which is used as a polarizer, a film obtained by applying a composition comprising a dichroic dye having liquid crystallinity or a composition comprising a dichroic dye and a liquid crystal compound to a substrate and curing the film, etc. Can be lifted. This film may be used as a linear polarizing plate by peeling the base material or together with the base material, or may be used as a linear polarizing plate in a structure having a protective film on one side or both surfaces thereof. As said protective film, the thing similar to the linearly polarizing plate provided with the said stretched film as a polarizer is mentioned.

Examples of the film obtained by applying the dye having absorption anisotropy include films described in JP 2013-37353 A, JP 2013-33249 A, and the like.

The film obtained by applying and curing the dye having absorption anisotropy is preferably thinner, but if it is too thin, the strength is lowered and the workability 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. and a relative humidity of 55%. The tensile modulus may be, for example, 0.5 GPa or more and 5 GPa or less.

(Phase difference 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, or the base film which supports a retardation layer. The retardation layer 32 includes a λ/4 layer, and may further include a λ/2 layer or a positive C layer. When the phase difference layer 32 includes a λ/2 layer, sequentially λ/2 layers and λ/4 layers are stacked from the straight polarizing plate 31 side. When the retardation layer 32 includes a positive C layer, the λ/4 layer and the positive C layer may be sequentially stacked from the straight polarizing plate 31 side, and the sequential positive C layer and λ/ from the straight polarizing plate 31 side may be stacked. Four layers may be stacked.

The retardation layer 32 may be formed of a resin film exemplified as a material for the above-described 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 base film, or may have a bonding layer for bonding the λ/4 layer and the λ/2 layer. The bonding layer is an adhesive layer or an adhesive layer, and can be formed using the above-described adhesive composition or a known adhesive composition. Examples of the known adhesive composition include water-based adhesive compositions such as aqueous polyvinyl alcohol-based resins and aqueous two-component urethane emulsion adhesives; And active energy ray-curable adhesive compositions that cure by irradiating active energy rays such as ultraviolet rays.

The entire retardation layer may have a thickness of 1 µm or more and 50 µm or less, for example.

(Second adhesive layer)

The second pressure-sensitive adhesive layer 40 is a layer for bonding the circular polarizing plate 30 and the TS panel 50, and can be formed using the pressure-sensitive adhesive composition. The thickness d of the second pressure-sensitive adhesive layer 40 is not particularly limited as long as the relationship between the above formulas (i) and (ii) can be satisfied, but is preferably 5 μm or more, may be 10 μm or more, and may be 15 μm or more It may be, may be 20 µm or more, and is usually 100 µm or less, preferably 80 µm or less, and more preferably 60 µm or less.

The second pressure-sensitive adhesive layer 40 preferably has a storage modulus Gd at a temperature of 25° C. and a relative humidity of 50% of 0.01 MPa or more, may be 0.02 MPa or more, may be 0.03 MPa or more, or may be 0.05 MPa or more, and , 0.2 MPa or less, preferably 0.15 MPa or less, 0.12 MPa or less, or 0.10 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 pressure-sensitive adhesive layer 40 increases, the flexible laminate 100 ) Has a tendency to decrease the flexibility. In addition, when the storage elastic modulus Gd of the second pressure-sensitive adhesive layer 40 is in the above-mentioned range, the flexible laminate 100 satisfies the relationship of the above formula (i) or the above formulas (i) and (ii). By doing so, it is possible to suitably obtain the flexible laminate 100 having impact resistance and excellent flexibility.

As an adhesive composition which comprises the 2nd adhesive layer 40, what was illustrated as the adhesive composition which comprises the 1st adhesive layer 20 can be used. The pressure-sensitive adhesive composition constituting the second pressure-sensitive adhesive layer 40 may be the same as or different from the pressure-sensitive adhesive composition constituting the first pressure-sensitive adhesive layer 20. Further, the formation of the second pressure-sensitive adhesive layer 40 can also be performed in the same manner as the formation of the first pressure-sensitive adhesive layer 20.

(Touch sensor panel)

If the TS panel 50 is a sensor capable of detecting the touched position, the detection method is not limited, and the resistance film method, the capacitive coupling method, the optical sensor method, the ultrasonic method, the electromagnetic induction coupling method, the surface acoustic wave method, etc. The TS panel is illustrated. Because of the low cost, a TS panel of a resistive film type or capacitive coupling type is suitably used.

An example of the resistive film type TS panel includes a pair of substrates disposed opposite each other, an insulating spacer sandwiched between the pair of substrates, a transparent conductive film provided as a resistive film on the entire inside surface of each substrate, and a touch. It is comprised by a position detection circuit. In an image display device provided with a resistive film type touch sensor panel, when the surface of the front panel 10 is touched, the opposing resistive film is shorted, and a current flows through the resistive film. The touch position detection circuit detects a change in voltage at this time, and the touched position is detected.

An example of the capacitive coupling type TS panel is composed of a substrate, a transparent electrode for position detection provided on the front 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 panel 10 is touched, the transparent electrode is grounded through the capacitance of the human body at the touched point. The touch position detection circuit detects the ground of the transparent electrode, and the touched position is detected.

The TS panel 50 may be composed of only a touch sensor pattern layer, or may include a touch sensor pattern layer and a support layer supporting the touch sensor pattern layer. When the TS panel 50 includes a touch sensor pattern layer and a support layer, both may be joined by a bonding layer, or a touch sensor pattern layer may be formed on the support layer without passing through the bonding layer. The bonding layer is an adhesive layer or an adhesive layer, and can be formed using the above-described adhesive composition and adhesive composition.

The touch sensor pattern layer of the TS panel 50 may include a conductive layer such as an electrode or wiring. It is preferable that the conductive layer is formed so as not to be visible when used as a flexible laminate as the TS panel 50. The touch sensor pattern layer may include a separation layer. The separation layer is formed on a substrate such as glass, and can be installed 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 material layer or an organic material layer. Examples of the material for forming the inorganic material layer include silicon oxide. As the material for forming the organic layer, for example, (meth)acrylic resin composition, epoxy resin composition, polyimide resin composition, or the like can be used. The touch sensor pattern layer may also include at least one protective layer. The protective layer may 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 spin coating, sputtering, vapor deposition, or the like. The conductive layer may be a transparent conductive layer containing a metal oxide such as ITO, or a metal layer containing a metal such as aluminum, copper, silver, or gold. Further, the touch sensor pattern layer may be composed of only a conductive layer such as an electrode or wiring. The support layer is preferably a resin film. For example, polyester resin films such as cyclic olefin resin films and polyethylene terephthalate resin films, acrylic resin films, and triacetyl cellulose resin films can be used.

The TS panel 50 preferably has a stiffness of 15 MPa·mm or more at a temperature of 23° C. and a relative humidity of 55%, and may be 50 MPa·mm or more, 100 MPa·mm or more, and 700 MPa or less. It is preferable that it may be 600 MPa·mm or less, or 500 MPa·mm or less. When the rigidity of the TS panel 50 decreases, the flexibility of the flexible laminate 100 improves, while the impact resistance tends to decrease, and when the rigidity of the TS panel 50 increases, the flexibility of the flexible laminate 100 increases. While the impact resistance is improved, the flexibility tends to decrease. Further, when the stiffness of the TS panel 50 is within the above-mentioned range, the flexible laminate 100 satisfies the relationship between the formula (i) or the formulas (i) and (ii), thereby providing good It is possible to suitably obtain the flexible laminate 100 having impact properties and excellent flexibility.

The stiffness [MPa·mm] of the TS panel 50 is the product of the tensile modulus Ee [MPa] at a temperature of 23° C. and a relative humidity of 55% of the TS panel 50 and the thickness [mm] of the TS panel 50. It can be calculated by (Ee[MPa]×e[µm]×10 ^-3 ). The thickness e of the TS panel 50 may be, for example, 3 µm or more and 100 µm or less, 5 µm or more and 50 µm or less, 5 µm or more and 30 µm or less, or 5 µm or more and 20 µm or less. The tensile modulus Ee of the touch sensor panel may be, for example, 1 GPa or more and 7 GPa or less, or 1.2 GPa or more and 6 GPa or less.

(Image display device)

2 is a schematic cross-sectional view schematically showing an example of the image display device of the present embodiment. The image display device 300 includes a flexible laminate 100 including a front plate 10 disposed on its front side (viewer side), a display laminate 200 including a display unit, and a bonding layer 60 ), the display laminate 200 is laminated on the circular flat plate 50 side of the flexible laminate 100 through the bonding layer 60. Since the flexible laminate 100 includes the TS panel 50, such an image display device 300 can be used as a touch panel display device.

The image display device 300 may be a flexible display panel. The image display device as a flexible display may be configured such that the front panel 10 surface can be folded inside and folded, or the front panel 10 surface can be folded inside to be wrapped.

The bonding layer 60 is for bonding the circular polarizing plate 30 and the display laminate 200 in the flexible laminate 100. When laminating the flexible laminate 100 and the display laminate 200, for example, the bonding layer 60 is formed on the circular polarizing plate 30 of the flexible laminate 100, and on the bonding layer 60 The display stack 200 may be stacked. The bonding layer 60 is an adhesive layer or an adhesive layer, and may be formed using the above-described adhesive composition and adhesive composition.

Examples of the display unit included in the display stacked body 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 type display element.

The image display device 300 can be used as mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic signage, measuring and measuring instruments, office equipment, medical equipment, and computerized equipment.

[Example]

Hereinafter, the present invention will be described in more detail by examples, but the present invention is not limited by these examples. "%" and "part" in an Example and a comparative example are mass% and mass part, unless otherwise specified.

[Measurement of thickness]

The thickness of each layer constituting the flexible laminate was measured in 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 Seisakusho), and the flexible laminate was obtained from the obtained observation. The thickness of each layer constituting the was measured.

[Measurement of tensile modulus]

The tensile modulus was measured using a tensile tester (AG-1S, manufactured by Shimadzu Corporation) at a temperature of 23°C and a relative humidity of 55%. When the measurement target was a retardation layer, the tensile modulus of elasticity in the slow axis direction was measured.

[Calculation of stiffness]

Stiffness was calculated by calculating the product of the value of the thickness measured above and the value of the tensile modulus.

[Measurement of storage modulus]

For the measurement sample in which each pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer or second pressure-sensitive adhesive layer) was stacked to have a thickness of 150 µm, using a rheometer (Anton Parr, MCR-301), the temperature was 25°C and the relative humidity was 50%. , Storage modulus (Gb, Gd) was measured under the conditions of 1% stress and 1 Hz frequency.

[Shock resistance test]

On a glass (Soda Glass 1.1T, manufactured by JMC Glass), using a 100 µm thick optical adhesive sheet (8146-04, manufactured by 3M), a touch sensor panel of a flexible laminate obtained in each Example and Comparative Example By fixing the side, a sample for evaluation was prepared. After installing this sample for evaluation, the front panel side is placed on the impact resistance test device (Drop Tester, manufactured by TAEWON TECH CO.), and the test sphere is free from the position of 5 cm above the surface of the front panel side of the evaluation panel. The impact resistance test which falls and collides with the sample for evaluation was performed at the temperature of 25 degreeC. This impact resistance test was performed while changing the weight of the test sphere, to determine the weight of the test sphere when the glass at the bottom of the sample for evaluation broke. The weight of the test tool when the glass of the evaluation sample is broken,

A for 100 g or more, A,

B when 50 g or more and less than 100 g,

C less than 50 g

The impact resistance was evaluated.

[Flexibility test]

(1) Flexibility (in) test

In order to evaluate the bendability (in) which bends at the temperature of 25°C with the front plate side inward, the bendability (in) test was performed in the following procedure. The flexible laminate obtained in each of the Examples and Comparative Examples was installed in a flexure tester (CFT-720C, manufactured by Covotech) in a flat state (non-flexed state), and the front panel side was turned inside to face the opposite side. After bending the flexible laminate so that the distance between the front plates was 4.0 mm, a bending operation was performed to return to the original flat state. When this bending operation was performed once, the number of times of bending was counted, and this bending operation was repeated. The number of bends when cracks or excitation of the pressure-sensitive adhesive layer occurred in a region bent by a bending operation was confirmed as the limit bend number. The occurrence of cracks or lifting of the pressure-sensitive adhesive layer in the bent region due to the bending operation,

A is the case where the number of bends is not visible even after reaching 200,000 times.

B, when the number of bendings was seen from 100,000 times to less than 200,000 times,

The case where the number of bends was seen from 50,000 to less than 100,000 is C,

The case where the number of bends was seen less than 50,000 times is D

The evaluation of the flexibility test (in) was carried out.

(2) Flexibility (out) test

In order to evaluate the bendability (out) of bending the front panel side outward, an operation of bending the flexible laminate is performed so that the distance between the TS panel sensors is 4.0 mm when the front panel side is bent to the outside. Except for the above, the bending operation was repeated in the same procedure as in the above (1) Flexibility (in) test to check the number of limit bendings. The evaluation of the bendability (out) test was also performed in the same manner as the evaluation of the bendability (in) test.

[Example 1]

(Preparation of front panel)

As the front plate, a resin film with a hard coat layer having a thickness of 60 µm was formed with a hard coat layer formed on one side of the resin film. The resin film was a polyimide-based resin film having a thickness of 50 μm, the hard coat layer had a thickness of 10 μm, and was a layer formed of a composition containing a dendrimer compound having a polyfunctional acrylic group at the terminal.

(Preparation of the first adhesive layer)

On the release film, an acrylic pressure-sensitive adhesive composition was applied 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 modulus Gb at a temperature of 25° C. and a relative humidity of 50% was 0.09 MPa.

(Preparation of circular polarizing plate)

A polyvinyl alcohol (PVA) film having an average polymerization degree of about 2,400, a saponification degree of 99.9 mol% or more, and a thickness of 20 μm was prepared. After immersing the PVA film in pure water at 30°C, iodine dyeing was performed by immersing it in an aqueous solution having an iodine/potassium iodide/water mass ratio of 0.02/2/100 at 30°C (iodine dyeing process). The PVA film subjected to the iodine dyeing process was immersed in an aqueous solution having a potassium iodide/boric acid/water mass ratio of 12/5/100 at 56.5°C to carry out boric acid treatment (boric acid treatment step). The PVA film which had been subjected to the boric acid treatment step was washed with pure water at 8° C., and then dried at 65° C. to obtain a polarizer in which iodine was adsorbed and oriented in polyvinyl alcohol. The stretching of the PVA film was performed in an iodine dyeing step and a boric acid treatment step. The total draw ratio of the PVA film was 5.3 times. The thickness of the obtained polarizer was 7 µm.

The obtained polarizer and a 13 µm-thick cycloolefin polymer (COP) film (ZF-14, manufactured by Nippon Zeon Co., Ltd., in-plane phase difference value at a wavelength of 550 nm of 1 nm) were bonded with a nip roll through an aqueous adhesive. . It dried at 60 degreeC for 2 minutes, maintaining the tension of the obtained bonding body at 430 Nm, and obtained the linear polarizing plate which has a COP film on one side. In addition, the water-based adhesive contains 100 parts of water, 3 parts of a carboxyl group-modified polyvinyl alcohol ("Kurarefoval KL318", manufactured by Kurabe Corporation), and 3 parts of water-soluble polyamide epoxy resin ("Sumirez resin 650" (solid content concentration 30 % Aqueous solution), manufactured by Taoka Kagaku Kogyo Co., Ltd.) 1.5 parts.

On the polarizer side of the linear polarizer obtained above, a retardation film was laminated through an adhesive layer. As the retardation film, those in which the λ/2 layer and the λ/4 layer were bonded through an ultraviolet curing adhesive were used. The λ/2 layer had a layer cured by a liquid crystal compound and an alignment film, and had a thickness of 3 μm. The pressure-sensitive adhesive layer had a thickness of 5 μm, a storage elastic modulus at a temperature of 25° C. and a relative humidity of 50% of 0.6 MPa. The λ/4 layer had a layer cured by a liquid crystal compound and an alignment film, and had a thickness of 2 μm.

(Preparation of the second adhesive layer)

On the release film, an acrylic pressure-sensitive adhesive composition was applied 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 modulus Gd at a temperature of 25°C and a relative humidity of 50% was 0.1 MPa.

(Preparation of touch sensor panel)

A touch sensor pattern layer was prepared as a TS panel. 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 modulus of 4510 MPa at a temperature of 23°C and a relative humidity of 55%. It was. The rigidity of the TS panel was 31.6 MPa·mm.

(Production of flexible laminate)

Corona treatment was performed on one surface of the front plate and the first adhesive layer side of the first adhesive layer provided with the release film, and the corona-treated surfaces were joined together. Subsequently, the release film adhered to the first pressure-sensitive adhesive layer is peeled off, and corona treatment is performed on the exposed side and the side of the linearly polarizing plate on the side of the linearly polarizing plate, and the corona-treated surfaces are joined to each other to form a composite of the front plate and the circularly polarizing plate. Got. Subsequently, corona treatment was performed on the surface of the composite on the side of the λ/4 layer and the surface of the second pressure sensitive adhesive layer of the second pressure sensitive adhesive layer with the release film, and the surfaces of the corona treatment were bonded. Subsequently, the release film adhered to the second pressure-sensitive adhesive layer was peeled off to perform corona treatment on the exposed surface, and the transparent conductive layer side of the TS panel and the corona-treated surface were bonded to obtain a flexible laminate. In addition, the corona treatment performed above was 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 adhesive layer 20, the circular polarizing plate 30, the second adhesive layer 40, and the TS panel 50 (the formula ( The thickness indicated by iii) was 157 µm, and a length of 177 mm×width of 105 mm. The flexible laminate was subjected to impact resistance tests, flexural (in) tests, and flexural (out) tests. Table 1 shows the results.

[Examples 2 to 9 and Comparative Example 1]

As the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer, one having a thickness described in Table 1 and a storage elastic modulus at a temperature of 25°C was used, and as a front plate, one surface of the resin film having the thickness described in Table 1 was shown in Table 1 A flexible laminate was produced in the same procedure as in Example 1 except that the one having the hard coat layer having the thickness described in the above was used, and that having the thickness and stiffness shown in Table 1 was used as the TS panel. The resin films used for the front plate were all polyimide-based resin films, and the hard coat layers used for the front plate were all formed of a composition containing a dendrimer compound having a polyfunctional acrylic group at the terminal. The obtained flexible laminate was subjected to an impact resistance test, a flexural (in) test, and a flexural (out) test. Table 1 shows the results.

10: front plate, 20: first adhesive layer, 30: circular polarizing plate, 31: linear 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 (9)

A flexible laminate comprising a front plate, a first adhesive layer, a circular 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 adhesive layer is b [µm], the thickness of the circular polarizing plate is c [µm], the thickness of the second adhesive layer is d [µm] and the touch When the thickness of the sensor panel is e[µm], the tensile modulus at the temperature of 23°C of the front panel and the relative humidity of 55% is Ea[GPa], the following formula (i):
{Ea×(a+b)}/(a+b+c+d+e)≥1.5 (i)
Flexible laminate that satisfies the relationship of According to claim 1, The tensile modulus Ea [GPa] of the front plate, the thickness b of the first pressure-sensitive adhesive layer, and the thickness d of the second pressure-sensitive adhesive layer, the following formula (ii):
b/(Ea×d)≥0.3 (ii)
Flexible laminate that satisfies the relationship of The rigidity at 23° C. and relative humidity of 55% of the front plate is 0.09 GPa·mm or more and 0.7 GPa·mm or less, according to claim 1 or 2,
The circular polarizing plate has a rigidity at a temperature of 23° C. and a relative humidity of 55% of 40 MPa·mm or more and 400 MPa·mm or less,
The rigid laminate at a temperature of 23° C. and a relative humidity of 55% of the touch sensor panel is 15 MPa·mm or more and 700 MPa·mm or less. The storage modulus of any one of claims 1 to 3 at a temperature of 25°C and a relative humidity of 50% of the first pressure-sensitive adhesive layer is 0.01 MPa or more and 0.15 MPa or less,
The flexible laminate having a storage elastic modulus at a temperature of 25°C and a relative humidity of 50% of the second pressure-sensitive adhesive layer is 0.01 MPa or more and 0.15 MPa or less. The thickness a of the front plate, the thickness b of the first adhesive layer, the thickness c of the circular polarizing plate, the thickness d of the second adhesive layer and the touch sensor panel according to any one of claims 1 to 4, The total thickness t [µm] of the thickness e of the following formula (iii):
t=a+b+c+d+e (iii)
When represented by, t is a flexible laminate of 250 ㎛ or less. The flexible laminate according to any one of claims 1 to 5, 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 side of the resin film. The flexible laminate according to any one of claims 1 to 6, wherein the flexible laminate has a limit number of flexures of 50,000 or more in a bending test in which the front plate side is bent inward. The flexible laminate according to any one of claims 1 to 7, wherein the flexible laminate has a limit number of flexures of 50,000 or more in a flexibility test in which the front plate side is bent outward. An image display device comprising the flexible laminate according to any one of claims 1 to 8, wherein the front plate is disposed on the front surface.

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