CN114514570A - Flexible image display device and optical laminate used therefor - Google Patents

Abstract

The present invention relates to a flexible image display device including a window member, a first member, a first laminate or a first panel member with a touch sensor, and a multilayer adhesive member, wherein the first laminate is a second member When the laminated body with the 3A member (including the panel member) includes the first laminated body, one of the first member and the second member is an optical film, and the other is an optical film or a touch sensor; In the case of the first panel member with a touch sensor, the first member is an optical film. E0×T0≦0.32 (E0: elastic modulus (GPa) of the window member, T0: thickness (mm) of the window member), the thickness of the first adhesive member disposed between the window member and the first member is 10 μm or less , the thickness of at least one layer of adhesive members other than the first adhesive member is 18 μm or more.

Description

Flexible image display device and optical laminate therefor

technical field

The present invention relates to a flexible image display device and an optical laminate including a multilayer adhesive member.

Background technique

A flexible image display device includes, for example, a panel member including a display panel, and an optical laminate disposed on the front surface of the panel member. The optical laminate may include, for example, a window member and an optical film, and may further include a touch sensor. An adhesive layer or an adhesive layer is arranged between each member included in the optical laminate and between the panel member and the optical laminate.

For example, Patent Document 1 proposes a foldable display device including a display panel, a polarizing member provided on the display panel, a window provided on the polarizing member, and a window provided between the display panel and the polarizing member. A first adhesive member, and a second adhesive member provided between the polarizing member and the window. Patent Document 1 describes that a foldable display device may include a touch sensing unit. In addition, Patent Document 1 describes a foldable display device including a window WD, a touch sensor unit TSU, a polarization member POL, and a display panel DP. A first adhesive member AD1 is arranged between the window WD and the touch sensor unit TSU, a fourth adhesive member AD4 is arranged between the touch sensor unit TSU and the polarizing member POL, and a fourth adhesive member AD4 is arranged between the polarizing member POL and the display panel DP. The second adhesive member AD2 is arranged therebetween.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Application Laid-Open No. 2017-126061 (Claim 1, [0132], [0138] and FIG. 7B )

SUMMARY OF THE INVENTION

The problem to be solved by the invention

In a flexible image display device, since the window member side is the surface (viewable side), a high pencil hardness is required for the surface on the window member side. However, even when a high pencil hardness is obtained only by the window member, the pencil hardness may be greatly reduced in a state in which the adhesive member is bonded to another member. On the other hand, if the pencil hardness is increased, when the flexible image display device is repeatedly bent in a high-temperature environment, peeling may occur between the members to be bonded, and high adhesiveness may not be ensured.

way of solving the problem

One aspect of the present invention relates to a flexible image display device comprising:

window components,

the first member laminated on the above-mentioned window member,

A first laminate or a first panel member with a touch sensor laminated on the window member via the first member, and

multi-layer adhesive components,

The first laminated body is a laminated body of a second member and a 3A member, the second member is laminated on the window member via the first member, and the 3A member is sandwiched between the first member and the second member. laminated on the above-mentioned window member,

When the above-mentioned flexible image display device includes the above-mentioned first laminate,

One of the first member and the second member is an optical film, and the other is an optical film or a touch sensor,

The above-mentioned 3A member includes at least a panel member,

The multi-layered adhesive member includes at least being disposed between the window member and the first member, disposed between the first member and the second member, and disposed between the second member and the 3A member the three layers,

When the above-mentioned flexible image display device includes the above-mentioned first panel member with a touch sensor,

The above-mentioned first member is an optical film,

The multi-layered adhesive member includes at least two layers arranged between the window member and the first member, and between the first member and the first panel member with a touch sensor,

When the elastic modulus (GPa) of the above-mentioned window member is E0 and the thickness (mm) of the above-mentioned window member is taken as T0, E0×T0≦0.32,

The thickness of the first adhesive member disposed between the window member and the first member satisfies the condition of 10 μm or less,

The thickness of at least one layer of the above-mentioned multilayered adhesive member other than the above-mentioned first adhesive member satisfies the condition of 18 μm or more.

Another aspect of the present invention relates to an optical laminate used in the above-mentioned flexible image display device,

The above-mentioned optical laminate includes:

window components,

the first member laminated on the above-mentioned window member,

a second laminate or a first spacer laminated on the window member via the first member, and

multi-layer adhesive components,

The second laminated body is a laminated body of a second member and a 3B member, the second member is laminated on the window member via the first member, and the 3B member is sandwiched between the first member and the second member. laminated on the above-mentioned window member,

When the said optical laminated body is equipped with the said 2nd laminated body,

One of the first member and the second member is an optical film, and the other is an optical film or a touch sensor,

The above-mentioned 3B member includes at least a second spacer,

The multi-layered adhesive member includes at least being disposed between the window member and the first member, disposed between the first member and the second member, and disposed between the second member and the 3B member the three layers,

When the said optical laminated body is provided with the 1st spacer,

The above-mentioned first member is an optical film,

The multi-layered adhesive member includes at least two layers arranged between the window member and the first member, and between the first member and the first spacer,

When the elastic modulus (GPa) of the above-mentioned window member is E0 and the thickness (mm) of the above-mentioned window member is taken as T0, E0×T0≦0.32,

The thickness of the said 1st adhesive member arrange|positioned between the said window member and the said 1st member satisfies the condition of 10 micrometers or less,

The thickness of at least one layer of the above-mentioned multilayered adhesive member other than the above-mentioned first adhesive member satisfies the condition of 18 μm or more.

effect of invention

High pencil hardness can be secured on the surface on the window member side of the flexible image display device and the optical laminate used therefor. In addition, when the flexible image display device is repeatedly bent in a high temperature environment, it is possible to ensure high adhesiveness between the laminated members.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a flexible image display device according to a first embodiment of the present invention.

2 is a schematic cross-sectional view of a flexible image display device according to a second embodiment of the present invention.

3 is a schematic cross-sectional view of a flexible image display device according to a third embodiment of the present invention.

Symbol Description

1, 101, 201: Flexible Image Display Device

11: Window components

111: Window Film

112: Hard coating

12, 12A, 12B: Optical film

121: Polarizer

122: Protective film

123, 124: retardation layer

13: Touch Sensor

131: Transparent conductive layer

132: Transparent film

14: Panel Components

141: Organic EL Panel

142: Film sealing layer

15A: 1st panel member with touch sensor

15B: Second panel member with touch sensor

L: 1st laminated body

21: Adhesive member (first adhesive member)

22, 23: Adhesive components

30: Decorative layer

Detailed ways

The flexible image display device of the present invention includes a window member, a first member laminated on the window member, a first laminated body of the window member or a first panel member with a touch sensor laminated on the window member via the first member, and a plurality of layers of adhesion member. The 1st laminated body is a laminated body of the 2nd member laminated|stacked on a window member via a 1st member, and the 3A member laminated|stacked via a 1st member and a 2nd member.

When the flexible image display device includes the first laminate, one of the first member and the second member is an optical film, and the other is an optical film or a touch sensor. The 3A member includes at least a panel member. In this case, the multi-layered adhesive member includes at least three elements disposed between the window member and the first member, disposed between the first member and the second member, and disposed between the second member and the 3B member Floor.

When the flexible image display device includes the first panel member with a touch sensor, the first member is an optical film. In this case, the multi-layered adhesive member includes at least two layers arranged between the window member and the first member, and between the first member and the first panel member with a touch sensor.

In addition, the present invention also includes an optical laminate used for the above-mentioned flexible image display device. The optical laminate includes a window member, a first member laminated on the window member, a second laminate or a first spacer laminated on the window member via the first member, and a multilayered adhesive member. The 2nd laminated body is a laminated body of the 2nd member laminated|stacked on a window member via a 1st member, and the 3B member laminated|stacked via a 1st member and a 2nd member.

When an optical laminated body is equipped with a 2nd laminated body, one of a 1st member and a 2nd member is an optical film, and the other is an optical film or a touch sensor. The 3B member includes at least the second spacer. The multilayered adhesive member includes at least three layers arranged between the window member and the first member, between the first member and the second member, and between the second member and the 3B member.

When the optical laminate includes the first separator, the first member is an optical film. In this case, the multi-layered adhesive member includes at least two layers arranged between the window member and the first member and between the first member and the first spacer.

The optical laminate is used for a flexible image display device in a state where the separator (specifically, the first separator or the second separator included in the 3B member) is peeled off. The above-mentioned flexible image display device includes the optical laminate in the state where the spacer is peeled off in the state where the window member is arranged on the visible side.

In the above-mentioned flexible image display device and optical laminate, when the elastic modulus (GPa) of the window member is E0 and the thickness (mm) of the window member is T0, E0×T0≦0.32. The product of the elastic modulus and the thickness (=E0×T0) represents the degree of toughness (or hardness) of the window member. It should be noted that the unit of E0×T0 is kN/mm.

The flexible image display device is used in a state where the surface on the side of the window member is on the visible side and exposed. Therefore, high damage resistance is required for the surface on the side of the window member. The damage resistance of the surface on the side of the window member can be evaluated, for example, by a pencil hardness test. However, it has been clarified that, even in the case where a high pencil hardness is obtained only by the window member, if a flexible image display device is produced by laminating other members (eg, optical films and touch sensors) and an adhesive member, the window member will The pencil hardness of the side surface is also greatly reduced. The adhesive member has high viscosity even in a state where the members are bonded together, unlike the bonding member that bonds the members together by curing. Therefore, if there is an adhesive member in the flexible image display device, when the surface on the side of the window member is pressed, the stress is relieved by the adhesive member. Damage reduction. When the optical laminate is provided with a multi-layered adhesive member, such a decrease in damage resistance becomes more remarkable. On the other hand, in the case of the cured adhesive member, relaxation of stress as in the case of the adhesive member is unlikely to occur, and almost no reduction in damage resistance is observed. In a flexible image display device, since high flexibility is required for the constituent member, it is considered that the influence on the pencil hardness by the adhesive member with high viscosity tends to become conspicuous.

In addition, the adhesive member is an adhesive agent after hardening, and has no fluidity. On the other hand, the adhesive member is a non-curable adhesive and has fluidity.

When the scratch resistance of the surface on the side of the window member is improved, the flexibility of the optical laminate or the flexible image display device tends to decrease. Even if the flexible image display device with high damage resistance on the surface on the side of the window member is repeatedly bent at room temperature (20° C. to 35° C.), peeling is unlikely to occur between the laminated members. However, it has been found that if the flexible image display device is repeatedly bent in a high temperature environment (for example, 60° C.), peeling may occur between the laminated members and high adhesiveness cannot be ensured.

In the flexible image display device and the optical laminate of the present invention, when E0×T0≦0.32, the thickness of the adhesive member (hereinafter referred to as the first adhesive member) disposed between the window member and the first member is 10 μm or less . Further, the thickness of at least one layer other than the first adhesive member among the multilayer adhesive members included in the flexible image display device or the optical laminate is made to satisfy the condition of 18 μm or more. By setting the thickness of the first adhesive member to be 10 μm or less, even if the flexible image display device and the optical laminate are provided with at least three layers or at least two layers of the adhesive member, the amount of the adhesive member when the surface on the side of the window member is pressed can be reduced. deformed. As a result, high damage resistance (more specifically, high pencil hardness) of the surface on the side of the window member can be ensured. In addition, by using at least three layers or at least two layers of the adhesive member, high flexibility of the optical laminate can also be ensured. In addition, by setting the thickness of at least one layer of the adhesive members other than the first adhesive member to be 18 μm or more, even if bending is repeated in a high temperature environment, peeling between the laminated members can be suppressed. That is, high adhesiveness can be ensured even in a high temperature environment.

In the flexible image display device of the present invention, it is possible to secure a high pencil hardness higher than F on the side of the window member. In addition, in the flexible image display device of the present invention, a high pencil hardness of H or more can be secured on the window member side.

In addition, in this specification, pencil hardness means the scratch hardness (pencil method) prescribed|regulated to JISK5600-5-4:1999. Pencil hardness can be measured based on JIS K 5600-5-4:1999 under the conditions of a load of 750 g and a temperature of 25°C.

For example, the hardness of each member in a flexible image display device represented by a window member or an optical laminate can be adjusted by adjusting the material, layer composition and/or thickness of each member.

(adhesive member)

The optical laminate or the flexible image display device includes a multi-layered adhesive member. More specifically, when the flexible image display device (or the optical laminate) includes the first laminate (or the second laminate), the flexible image display device (or the optical laminate) includes at least the one disposed between the window member and the first member. A three-layer adhesive member between the first member and the second member, and between the second member and the 3A member (or the 3B member). When the flexible image display device (or the optical laminate) includes the first touch sensor-equipped panel member (or the first spacer), the multi-layered adhesive member includes at least the first and second adhesive members disposed between the window member and the first member. A two-layer adhesive member between the member and the first panel member with touch sensor (or the first spacer). The multi-layered adhesive member may include such an adhesive member other than the three-layer or two-layer adhesive member disposed between adjacent members. Adhesive members other than the above-mentioned three-layer or two-layer adhesive members are arranged in each member other than the window member (specifically, selected from the first member, the second member, the 3A member (or the 3B member), the and at least one of the first touch-sensor-equipped panel members). Each adhesive member is usually layered. The number of the adhesive members in each member is not particularly limited, and may be 0 layers, one layer, or two or more layers. In this way, the adhesive member (that is, the multi-layered adhesive member) included in the flexible image display device or the optical laminate includes the adhesive member included between adjacent members and the adhesive member included in each member. Component of both.

The adhesive member contained in the flexible image display device or the optical laminate may be, for example, 8 layers or less, 7 layers or 6 layers or less, or 5 layers or 4 layers or less.

The thickness of the first adhesive member is 10 μm or less, and may be 8 μm or less or 6 μm or less. In the present invention, when the product of the elastic modulus E0 (GPa) of the window member and the thickness T0 (mm) of the window member E0×T0≦0.32, the thickness of the first adhesive member is set in such a range , high pencil hardness can be secured on the window member side of the flexible image display device regardless of the kind of material constituting each adhesive member.

From the viewpoint of easily securing higher flexibility in the flexible image display device, the thickness of each layer of the adhesive member is preferably 3 μm or more, more preferably 5 μm or more, may be 8 μm or more, or 10 μm or more, and may be is 13 μm or more.

The thickness of at least one layer of the adhesive member other than the first adhesive member in the multilayered adhesive member is 18 μm or more, and may be 20 μm or more. In the present invention, when the product of the elastic modulus E0 (GPa) of the window member and the thickness T0 (mm) of the window member is E0×T0≦0.32, at least one layer other than the first adhesive member The thickness of the adhesive member is set in such a range that even when the flexible image display device is repeatedly bent in a high-temperature environment, high adhesiveness between the laminated members can be ensured. The thickness of at least one adhesive member other than the first adhesive member may be 50 μm or less, or 40 μm or less, from the viewpoint of easily securing higher damage resistance on the surface on the window member side of the flexible image display device. 30μm or less.

The thickness of at least one layer of the adhesive members other than the first adhesive member may be 18 μm or more (or 20 μm or more). The thickness of at least two layers of the adhesive members other than the first adhesive member may be 18 μm or more or 20 μm or more. The thickness of the adhesive member having such a thickness may be 50 μm or less, 40 μm or less, or 30 μm or less from the viewpoint of easily securing higher damage resistance.

From the viewpoint of ensuring higher adhesiveness, the thickness of the adhesive member located on the outer side is 18 μm or more (or 20 μm or more) than the adhesive member located on the inner side in the state where the flexible image display device is bent. advantageous.

The thickness of the remaining adhesive members among the adhesive members other than the first adhesive member is not particularly limited. As described above, from the viewpoint of flexibility, the thickness of the remaining adhesive members may be, for example, 3 μm or more, 5 μm or more, 8 μm or more, 10 μm or more, or 13 μm or more. The thickness of the remaining adhesive members may be 50 μm or less, 40 μm or less, or 30 μm or less.

In addition, in the flexible image display device, there may be cases between the surface of the window member on the side of the first member and the touch sensor or the panel member with touch sensor (specifically, the first or second panel member with touch sensor). , and set the decorative layer in contact with any layer of the adhesive member. When the thickness of the adhesive member in the portion where the decorative layer is provided is small, the difference in height due to the decorative layer is hardly absorbed by the adhesive member. Therefore, from the viewpoint of easily absorbing the height difference caused by the decorative layer, the thickness of the adhesive member with which the decorative layer is in contact can be set to 10 μm or more. In the present invention, since the thickness of the first adhesive member is relatively small, a decoration is provided on the surface of the first member on the second member side or in the first member from the viewpoint of easily absorbing the height difference caused by the decorative layer. Layers are more beneficial.

From the viewpoint of easily absorbing the height difference caused by the decorative layer, the thickness of the adhesive member in contact with the decorative layer may be 1.5 times or more, 2 times or more, or 2.5 times or more of the thickness of the decorative layer, and further It can also be set to 3 times or more.

The upper limit value and the lower limit value of the thickness of the layer of the above-mentioned adhesive member can be arbitrarily combined.

The thickness of the adhesive member can be measured by cutting out a cross section of the flexible image display device or the optical laminate, obtaining an image of the cross section with a scanning electron microscope (SEM), and measuring the thickness of the adhesive member based on the image. The thickness of an adhesive member can be calculated|required by measuring the thickness at arbitrary multiple places (for example, 5 places) in the SEM image of the said cross section, in the part where a decorative layer is not formed, and averaging.

The storage elastic modulus at 25°C of each adhesive member is usually 10 MPa or less, and may be 3 MPa or less, 2 MPa or less, or 1.5 MPa or less. The storage elastic modulus at 25° C. of each adhesive member is preferably 1 MPa or less, and may be 0.3 MPa or less or 0.2 MPa or less, or may be 0.15 MPa or less or 0.1 MPa or less. When the storage elastic modulus of the adhesive member is within such a range, high adhesiveness can be ensured, and unlike the case of the cured adhesive member, the stress due to pressing is easily relieved, and the pencil hardness tends to decrease. According to the present invention, even when the flexible image display device includes multiple layers of the above-described adhesive member that easily relieves stress caused by pressing, high pencil hardness can be secured by controlling the thickness of the first adhesive member. The storage elastic modulus at 25° C. of each adhesive member may be 0.001 MPa or more, or 0.005 MPa or more.

The upper limit value and the lower limit value of the storage elastic modulus of the above-mentioned adhesive member can be arbitrarily combined.

On the other hand, the storage elastic modulus of the adhesive member at 25° C. is larger than 10 MPa, and may be 100 MPa or more, and is usually about 1 GPa. In this specification, the adhesive member refers to a member having such a storage modulus.

As such, the adhesive member can be distinguished from the adhesive member based on the storage modulus.

The storage modulus of the adhesive member can be measured based on JIS K 7244-1:1998. Specifically, first, a molded product having a thickness of about 1.5 mm was produced using an adhesive member. This molded product was punched into a disk shape with a diameter of 7.9 mm to prepare a test piece. This test piece was sandwiched between parallel plates, and the viscoelasticity was measured under the following conditions using a dynamic viscoelasticity measuring apparatus (for example, "Advanced Rheometric Expansion System (ARES)" manufactured by Rheometric Scientific), and the temperature at 25°C was determined. storage modulus. In addition, the storage elastic modulus of an adhesive member was calculated|required also in the case of an adhesive member.

(measurement conditions)

Deformation Mode: Twist

Measurement frequency: 1Hz

Measurement temperature: -40℃～+150℃

Heating rate: 5°C/min

From the viewpoint of ensuring high visibility of the panel member, the total light transmittance of each adhesive member is preferably 85% or more, and more preferably 90% or more.

The total light transmittance of the adhesive member can be measured based on JIS K 7136K:2000. For the measurement, a test piece obtained by arranging an adhesive member on an alkali-free glass (thickness 0.8 to 1.0 mm, total light transmittance of 92%) so as to have a thickness of about 1.5 mm can be used.

Each adhesive member is formed of an adhesive. The type of the adhesive is not particularly limited, and examples thereof include acrylic adhesives, rubber-based adhesives, silicone-based adhesives, urethane-based adhesives, vinyl alkyl ether-based adhesives, Polyvinylpyrrolidone-based adhesives, polyacrylamide-based adhesives, and cellulose-based adhesives, etc. The adhesive may contain, for example, base polymers, cross-linking agents, additives (eg, tackifiers, coupling agents, polymerization inhibitors, delayed cross-linking agents, catalysts, plasticizers, softeners, fillers, colorants agents, metal powders, ultraviolet absorbers, light stabilizers, antioxidants, anti-deterioration agents, surfactants, antistatic agents, surface lubricants, leveling agents, preservatives, particles of inorganic or organic materials (metal compounds particles (metal oxide particles, etc.), resin particles, etc.)), but not limited to these.

If the adhesive which can obtain the above-mentioned storage modulus is used as an adhesive, the effect by controlling the thickness of an adhesive member becomes more remarkable easily, and it is advantageous. The adhesives constituting at least two layers of the multi-layered adhesive members may be the same, and the adhesives constituting the respective adhesive members may be different.

The adhesive member can be formed by, for example, applying the adhesive constituting each adhesive member to one of the members sandwiching each adhesive member, or by transfer-molding the adhesive into a sheet shape. And each adhesive member is arrange|positioned between each member by laminating|stacking the other one of the members which hold|maintain each adhesive member on the adhesive member. When the adhesive member is included in each member, the adhesive member is also arranged in each member according to the case where it is arranged between the members. For example, on one of the layers (or laminates) that constitute each member and sandwich the adhesive member, the adhesive member is arranged by applying or transferring the adhesive as described above, and the other is placed on the other side. The layer (or laminate) is attached to the adhesive member, whereby the adhesive member can be arranged in each member.

(window member)

In order to prevent breakage of the optical film, the touch sensor, the panel member with the touch sensor, and the panel member, the window member is arranged on the outermost surface on the visible side of the flexible image display device or the optical laminate.

When the product of the elastic modulus E0 and the thickness T0 of the window member is E0×T0≦0.32, the properties of the adhesive member (among them, the first adhesive member) included in the flexible image display device or the optical laminate are very important to the window. The pencil hardness of the surface on the member side has an influence. In addition, the thickness of at least one layer of the adhesive members other than the first adhesive member affects the adhesiveness between the laminated members (or between the layers constituting each member) when the flexible image display device is repeatedly bent in a high-temperature environment affect. In the present invention, by controlling the thickness of the first adhesive member as described above, it is possible to secure high pencil hardness on the surface on the side of the window member. In addition, by controlling the thickness of at least one layer other than the first adhesive member as described above, high adhesiveness can be secured even in a high-temperature environment.

The window member is usually provided with a window film. High flexibility (high exchangeability, etc.), high transparency (high total light transmittance, low haze, etc.), and high hardness are required for a flexible image display device or an optical laminate applied to the flexible image display device . The material of the window film is not particularly limited as long as these physical properties are satisfied.

As a window film, a transparent resin film is mentioned, for example. Examples of the resin constituting the transparent resin film include polyimide-based resins, polyamide-based resins, polyester-based resins, cellulose-based resins, acetate-based resins, styrene-based resins, sulfone-based resins, At least one of epoxy-based resins, polyolefin-based resins, polyetheretherketone-based resins, sulfide-based resins, vinyl alcohol-based resins, urethane-based resins, acrylic resins, and polycarbonate-based resins. However, the resin constituting the transparent resin film is not limited to these resins.

The thickness of the window film is, for example, 20 μm or more and 500 μm or less, or may be 30 μm or more and 200 μm or less. When the window film has such a thickness, it is easy to achieve both high strength and high flexibility.

In this specification, with respect to materials or members (molded bodies) other than the adhesive member or other than the adhesive, transparent means that the total light transmittance of the test piece is 80% or more. For the measurement of the total light transmittance, a test piece having a thickness of about 1.5 mm made of a transparent material or member can be used. The total light transmittance can be measured according to the case of the adhesive member.

The window member may also be provided with a hard coating. From the viewpoint of easily obtaining the high damage prevention effect of the window film, the hard coat layer is preferably provided on at least the side opposite to the first member side of the window member. More specifically, it is preferable that the hard coat layer is provided at least on the surface of the window film on the side opposite to the first member side (that is, the visible side of the window film).

The thickness of the hard coat layer is, for example, 1 μm or more and 100 μm or less, or may be 1 μm or more and 50 μm or less. When the window member is provided with a multilayered hard coat layer, the thickness of each hard coat layer may be set within such a range.

A hard-coat layer can be formed by apply|coating a curable coating agent to the surface of the layer (for example, a window film) which becomes a base, and making it harden.

As the coating agent, for example, a coating agent for optical films can be used. Examples of the coating agent include acrylic-based coating agents, melamine-based coating agents, urethane-based coating agents, epoxy-based coating agents, silicone-based coating agents, and inorganic-based coating agents, but It is not limited to this.

The coating agent may also contain additives. Examples of additives include silane coupling agents, colorants, dyes, powders or particles (pigments, inorganic or organic fillers, particles of inorganic or organic materials, etc.), surfactants, plasticizers, antistatic agents additives, surface lubricants, leveling agents, antioxidants, light stabilizers, ultraviolet absorbers, polymerization inhibitors, antifouling materials, etc., but are not limited to these additives.

The window member may be provided with another layer (hereinafter referred to as layer A) as necessary. Examples of the layer A include antireflection layers, antiglare layers, antifouling layers, antiadhesion layers, hue adjustment layers, antistatic layers, easy adhesion layers, layers for preventing precipitation of ions or oligomers, and shock absorbing layers. , anti-scattering layer, etc. A window member may contain the layer A of one layer, and may contain the layer A of a plurality of layers. The layer A is provided, for example, on the surface side or the first member side of another layer or laminate (for example, a window film) constituting the window member. Layer A may be directly formed on other layers or laminates constituting the window film by coating or the like, or may be laminated via an adhesive member. In addition, the window member does not contain an adhesive member. Here, the adhesive member refers to an adhesive member having the above-described storage elastic modulus at 25°C.

The thickness T0 of the window member is, for example, 0.02 mm or more and 0.6 mm or less, or may be 0.03 mm or more and 0.3 mm or less.

The thickness T0 of the window member can be measured by cutting out a cross section of the flexible image display device or the optical laminate, and based on an image of the cross section obtained by SEM. The thickness T0 can be obtained by measuring the thickness at arbitrary plural places (for example, five places) in the SEM image of the cross section and averaging.

In addition, in this specification, the thickness of the member which comprises an optical laminated body or a flexible image display apparatus can be calculated|required in the case of the thickness T0 of a window member.

The elastic modulus E0 of the window member is, for example, 0.53GPa or less and 16GPa or less, or may be 1GPa or more and 15GPa or less, 1GPa or more and 10GPa or less, or 3GPa or more and 8GPa or less.

The elastic modulus E0 (GPa) of the window member is an average value (arithmetic average) obtained by preparing three samples for measurement of the window member, measuring the elastic modulus of each sample by a tensile test, and averaging. The tensile test can be performed under the following conditions using the following apparatus.

Tensile testing machine: Shimadzu Corporation, Autograph AG-1S

Control: Stroke

Punctuation distance: 100mm

Tensile speed: 50mm/min

Calculation range of elastic modulus: 10N/mm ² ～20N/mm ²

In addition, the sample for elastic modulus measurement was produced as follows. First, the elastic modulus in the longitudinal and transverse directions of the window member is measured. Next, the length of the direction with a high elastic modulus was set to 150 mm, and the length of the direction with a low elastic modulus was set to 10 mm, and the window member was cut into an elongated shape to prepare a sample. In the cutting of the window member, for example, a universal test piece cutter manufactured by Dumbbell Corporation can be used.

E0×T0 (kN/mm) may be 0.32 or less as long as it is 0.3 or less. In addition, E0×T0 is, for example, 0.01 or more, and may be 0.02 or more, 0.05 or more, 0.1 or more, or 0.2 or more. The above-mentioned upper limit value and lower limit value can be arbitrarily combined.

(1st member and 2nd member)

In the flexible image display device and the optical laminate, the first member is laminated on the window member. When the flexible image display device (or the optical laminate) includes the first laminate (or the second laminate), the second member is laminated on the window member via the first member. It is a state in which the adhesive member is sandwiched between the window member and the first member, and between the first member and the second member, respectively. When the flexible image display device (or the optical laminate) includes the first laminate (or the second laminate), one of the first member and the second member is an optical film, and the other is an optical film or a touch sensor . The flexible image display device (or the optical laminate) may include a 3A member (or a 3B member), and one of the first member and the second member may be an optical film, and the other may be a touch sensor. When the flexible image display device includes a first panel member with a touch sensor and when the optical laminate includes a first spacer, the first member may be an optical film. In addition, when the 3A member includes a second panel member with a touch sensor, the first member and the second member may each be an optical film.

Since the first member and the second member are included in the flexible image display device, they have appropriate strength and flexibility. Let the elastic modulus (GPa) of the 1st member and the 2nd member be E1 and E2, respectively, and let the thickness (mm) of the 1st member and the 2nd member be T1 and T2, respectively. In this case, it is preferable that the first member and the second member satisfy the following conditions, respectively. For each member, by making the product of the elastic modulus and the thickness within such a range, the effect by controlling the thickness of each layer in the adhesive member as described above can be obtained more easily.

0.01≤E1×T1≤0.35(1st member)

0.01≤E2×T2≤0.35(Second member)

In addition, each unit of E1*T1 and E2*T2 is kN/mm.

(optical film)

The optical film refers to a film that imparts an optical function. The optical film is usually a laminate including at least one layer having an optical function. As an optical film, the optical film utilized in the field|area of an image display apparatus etc. is mentioned. Each of the first member and the second member may be an optical film, or may be a single layer or a laminate of two or more layers constituting an optical film.

As a layer which has an optical function, the layer which has optical anisotropy (for example, an optically anisotropic film) is mentioned, for example. Examples of the layer having optical anisotropy include, but are not limited to, polarizers, retardation layers, viewing angle widening films, viewing angle limiting (privacy) films, brightness improving films, and optical compensation films. The laminate of two or more layers may have two or more kinds selected from these layers having optical anisotropy. In a laminate of two or more layers, all the layers having optical anisotropy may have different functions, or at least two layers may have the same function. For example, the laminate may include a polarizer and a retardation layer, or may include two types of retardation layers having different compositions.

The optical film may include at least one layer having an optical function and a substrate layer maintaining the layer (or a protective layer protecting the layer). For example, the polarizer includes at least a film-shaped polarizer, and may be composed of a polarizer and a protective film for protecting the polarizer.

The polarizer is not particularly limited, and polarizers available in the field of image display devices and the like can be used. As a polarizer, the film obtained by making a dichroic substance adsorb|suck to a hydrophilic polymer film, and carrying out uniaxial stretching, and a polyene type oriented film are mentioned, for example. Examples of the hydrophilic polymer constituting the hydrophilic polymer film include polyvinyl alcohol-based resins (including partially formalized polyvinyl alcohol-based resins) and partially saponified products of ethylene-vinyl acetate copolymers. As a dichroic substance, iodine and a dichroic dye are mentioned, for example. As a material constituting the polyene-based alignment film, for example, a dehydration-treated product of a polyvinyl alcohol-based resin and a dehydrochlorination-treated product of a polyvinyl chloride-based resin can be mentioned.

As the polarizer, a thin polarizer having a thickness of 10 μm or less can be used. Examples of thin polarizers include: Japanese Patent Laid-Open No. 51-069644, Japanese Patent Laid-Open No. 2000-338329, International Publication No. 2010/100917 Pamphlet, Japanese Patent No. 4691205, Japanese Patent No. 4751481 The polarizer described in the gazette No. The thin polarizer can be obtained by, for example, a manufacturing method including a step of stretching a polyvinyl alcohol-based resin layer and a resin base material layer in a laminated state, and a step of dyeing with a dichroic dye.

As the protective film, for example, a polymer film excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, and optical isotropy can be used. As a polymer material having such properties, the protective film may contain, for example, at least one resin selected from the group consisting of cellulose-based resins, polyolefin-based resins (including cyclic polyolefin-based resins), acrylic resins, Imide-based resins (including phenylmaleimide-based resins), polyamide-based resins, polycarbonate-based resins, polyester-based resins (including polyarylate-based resins), acetate-based resins, polyamide-based resins Ethersulfone-based resins, polyvinyl chloride-based resins, polyvinylidene chloride-based resins, polystyrene-based resins, polyvinyl alcohol-based resins, sulfide-based resins (eg, polyphenylene sulfide-based resins), polyetheretherketone-based resins Resins, epoxy resins, and urethane resins. However, the resin constituting the protective film is not limited to these polymer materials.

The optical film may contain one protective film, or may contain two or more protective films. A protective film may be arrange|positioned on the surface of one side of the layer (for example, a polarizer) which has an optical function, and may be arrange|positioned on both surfaces. In addition, the optical film may include two or more layers having an optical function in which a protective film is arranged on one surface. When the optical film includes two or more protective films (for example, when protective films are arranged on both side surfaces of a polarizer), the composition of all the protective films may be different, or at least two protective films may be used. The composition in the film is the same.

In addition to the polarizer or the polarizer, the optical film may further include another film (hereinafter referred to as layer B) that imparts an optical function other than the polarizer or the polarizer. As the layer B, for example, a layer used in the field of image display devices and the like can be mentioned. Layer B may be, for example, an optically anisotropic film. As the layer B, among the above-mentioned layers having optical anisotropy, a layer other than a polarizer or a polarizing plate can be mentioned. Specifically, as layer B, a retardation layer, a viewing angle widening film, a viewing angle limiting (privacy protection) film, a brightness improvement film, and an optical compensation film are mentioned, for example. The optical film may contain one layer of such layer B, or may contain two or more layers of such layer B. However, the layer B is not limited to this.

The thickness of the optical film is, for example, 5 μm or more and 500 μm or less, and may be 10 μm or more and 100 μm or less.

The thickness of the polarizing plate is, for example, 200 μm or less. From the viewpoint of easily securing high flexibility, the thickness of the polarizing plate is preferably 100 μm or less, more preferably 80 μm or less or 70 μm or less. The thickness of the polarizing plate is, for example, 10 μm or more.

The thickness of the layer B is, for example, 0.1 μm or more and 100 μm or less. When the polarizer does not have a protective film (that is, when the layer B also functions as a protective film), it is preferable that the thickness of the laminate of the layer B and the polarizer falls within the range described for the thickness of the polarizer. way to adjust the thickness of layer B.

In addition, the layer which comprises an optical film can be laminated|stacked on the adjacent layer directly by coating etc.. Moreover, the layer which comprises an optical film may be laminated|stacked on the adjacent layer via an adhesive member or an adhesive member. For example, the layer B may be laminated on the polarizer via an adhesive member, or may be laminated on the polarizer via an adhesive member. In addition, when two or more layers of adjacent layers B are provided, the adjacent layers B may be laminated via an adhesive member or any member of the adhesive member.

(touch sensor)

As the touch sensor, for example, a touch sensor used in the field of image display devices and the like can be used. Examples of the touch sensor include, but are not limited to, touch sensors of a resistive film method, an electrostatic capacitance method, an optical method, or an ultrasonic method. In the flexible image display device and the optical laminate, when an optical film is present between the touch sensor and the window member, high sensitivity can be easily obtained by using a capacitive touch sensor.

A capacitive touch sensor usually includes a transparent conductive layer. As such a touch sensor, the laminated body of a transparent conductive layer and a transparent base material is mentioned, for example. As a transparent base material, a transparent film is mentioned, for example.

The transparent conductive layer is not particularly limited, and conductive metal oxides, metal nanowires, or the like can be used. Examples of the metal oxide include tin oxide-containing indium oxide (ITO: Indium Tin Oxide) and antimony-containing tin oxide. The transparent conductive layer may be a conductive pattern made of metal oxide or metal. Although a stripe shape, a square shape, a lattice shape, etc. are mentioned as a shape of a conductive pattern, it is not limited to these shapes.

The surface resistance value of the transparent conductive layer is, for example, 0.1Ω/□ or more and 1000Ω/□ or less, and may be 0.5Ω/□ or more and 500Ω/□ or less.

The thickness of the transparent conductive layer is, for example, 0.005 μm or more and 10 μm or less, and may be 0.01 μm or more and 3 μm or less.

As the transparent film, for example, a transparent resin film can be used. Examples of the resin constituting the transparent resin film include polyester-based resins (including polyarylate-based resins), acetate-based resins, polyethersulfone-based resins, polycarbonate-based resins, polyamide-based resins, and polyimides. resins, polyolefin-based resins, acrylic resins, polyvinyl chloride-based resins, polyvinylidene chloride-based resins, polystyrene-based resins, polyvinyl alcohol-based resins, sulfide-based resins (for example, polyphenylene sulfide-based resins ), polyether ether ketone resin, cellulose resin, epoxy resin, urethane resin, etc. A transparent resin film may contain 1 type of these resins, and may contain 2 or more types. Among these resins, polyester-based resins, polyimide-based resins, and polyethersulfone-based resins are preferred. However, the resin constituting the transparent resin film is not limited to these resins.

From the viewpoint of improving the adhesiveness between the transparent conductive layer and the transparent base material, a surface-treated transparent base material can also be used as the transparent base material. As the surface treatment, a known surface treatment can be employed. In addition, if necessary, before laminating the transparent conductive layer, the transparent substrate may be subjected to, for example, dust removal or cleaning treatment (cleaning treatment with a solvent, ultrasonic waves, or the like).

If necessary, other layers (hereinafter referred to as layer C) other than the transparent conductive layer and the transparent base material may be provided in the touch sensor. For example, as the layer C, an inner lining layer or an oligomer precipitation preventing layer may be provided between the transparent conductive layer and the transparent substrate. In addition, the layer C may be laminated on the surface of at least one of the transparent conductive layer and the transparent base material. Examples of the layer C include functional layers having desired functions (eg, films imparting the above-mentioned optical functions (optical anisotropic films, etc.), layers having the above-mentioned optical functions), decorative substrate films, and the like. The decorated base film is laminated on the surface of the transparent conductive layer, for example. However, the layer C is not limited to these layers. If necessary, the layer C may be laminated on the transparent conductive layer or the transparent base material via an adhesive member or an adhesive member.

The thickness of the entire touch sensor is, for example, 5 μm or more and 250 μm or less, or may be 10 μm or more and 200 μm or less.

(third member)

In the flexible image display device and the optical laminate, the third member is laminated on the window member via the first member and the second member. And it is the state which pinched the adhesive member between the 2nd member and the 3rd member. The third member of the flexible image display device is referred to as the 3A member. The 3A member includes at least a panel member. The third member of the optical laminate is referred to as a 3B member. The 3B member includes at least a spacer (a second spacer). The optical laminate is included in the flexible image display device in a state where the spacer is peeled off. Any member of the panel member and the panel member with a touch sensor is not included in the 3B member. The 3A member and the 3B member may each be a laminate. The 3A member and the 3B member may each include an adhesive member or an adhesive member.

The 3A member should just contain a panel member at least. The 3A member may be, for example, a laminate of a panel member and a protective member that protects the panel member. When the 3A member includes a protective member, the protective member is usually laminated on the side opposite to the second member side of the panel member. That is, the protective member is provided on the side opposite to the visible side of the panel member. However, these are merely examples, and the 3A-th member is not limited to these. When the 3A member is a laminated body, the adjacent layers (or members, eg, a panel member and a protective member) constituting the laminated body may be laminated via an adhesive member or an adhesive member.

Let the elastic modulus (GPa) of the 3A member be E3, and let the thickness (mm) of the 3A member be T3. It is preferable that the 3A member satisfies the following formula.

0.01≤E3×T3≤0.35

In the 3A member, by setting the product of the elastic modulus and the thickness within such a range, it becomes easier to obtain the effect by controlling the thickness of the adhesive member as described above. It should be noted that the unit of E3×T3 is kN/mm.

The 3B member in an optical laminated body should just contain a spacer at least. The 3B member may be constituted only by the spacer. The 3B member is stacked on the second member so that the spacer is brought into contact with the adhesive member disposed on the side opposite to the first member side of the second member. Then, the spacer is peeled off from the optical laminate, and the exposed adhesive member is bonded to the 3A member (specifically, a panel member or a laminate including the panel member) to form a flexible image display device.

(Panel member)

The panel member includes, for example, at least an image display panel. A sealing member (film sealing layer, etc.) may be arranged on the visible side of the image display panel. The sealing member is usually directly arranged on the visible side surface of the image display panel.

As the image display panel, well-known ones can be used. As an image display panel, an organic electroluminescence (EL: Electro Luminescence) panel is mentioned, for example.

(protection member)

As the protective member, for example, a sheet or a film (or a substrate) that holds or protects the panel member is exemplified. The protective member should just be a member having moderate strength for protecting the panel member while holding the panel member, and moderate flexibility so as not to hinder the flexibility of the flexible image display device. As the protective member, a resin sheet or the like can be used. The material of the resin sheet is not particularly limited, and can be appropriately selected, for example, according to the type of the image display panel.

(Panel member with touch sensor)

The touch sensor-equipped panel member (specifically, each member of the first touch-sensor-equipped panel member and the second touch-sensor-equipped panel member included in the 3A member) is formed by integrating the touch sensor and the panel member. Such a panel member with a touch sensor includes, for example, a panel member of an electrostatic capacitance type touch sensor in which a metal mesh electrode is formed on a thin film sealing layer of an organic light emitting diode (OLED: Organic Light Emitting Diode). As the touch sensor, the above description can be referred to.

The panel member includes, for example, at least an image display panel. A sealing member (film sealing layer etc.) may be arrange|positioned on the visible side of an image display panel. The sealing member is usually directly arranged on the visible side surface of the image display panel.

As the image display panel, well-known ones can be used. As an image display panel, an organic electroluminescence (EL: Electro Luminescence) panel is mentioned, for example.

The touch sensor-equipped panel member may include a protective member. As a protective member, the sheet|seat or film (or board|substrate) which hold|maintains or protects a panel member is mentioned, for example. The protective member should just be a member having moderate strength for protecting the panel member while holding the panel member, and moderate flexibility so as not to hinder the flexibility of the flexible image display device. As the protective member, a resin sheet or the like can be used. The material of the resin sheet is not particularly limited, and can be appropriately selected, for example, according to the type of the image display panel.

Let the elastic modulus (GPa) of the panel member with a touch sensor be Ep, and let the thickness (mm) of the panel member with a touch sensor be Tp. In this case, it is preferable that the panel member with a touch sensor satisfies the following formula.

0.01≤Ep×Tp≤0.35

In the panel member with a touch sensor, by setting the product of the elastic modulus and the thickness within such a range, the effect by controlling the thickness of each adhesive member as described above can be obtained more easily. It should be noted that the unit of Ep×Tp is kN/mm.

(spacer)

As the spacer (specifically, each of the first spacer and the second spacer included in the 3B member), for example, a base material sheet and a release agent arranged on at least one surface of the base material sheet can be used. release sheet. The separator is arranged in a state in which the release agent is in contact with the adhesive member. More specifically, the first spacer is arranged in a state of being in contact with the adhesive member arranged on the opposite side to the window member of the first member. The second spacer is arranged in a state of being in contact with the adhesive member arranged on the side opposite to the first member side of the second member.

The base material sheet may be any material as long as it maintains the structure other than the first spacer or the third B member of the optical laminate, has moderate strength and flexibility, and can easily form a release agent layer. As the base sheet, a resin film, paper, a laminate thereof, or the like can be used. The material of the base sheet can be determined depending on the type of release agent, the structure of the optical laminate, and the like. As a resin film, a polyester film (polyethylene terephthalate film etc.), a polyolefin film (polypropylene film etc.) can be used, for example. The thickness of the base material sheet is not particularly limited, either, and can be selected in consideration of desired releasability. As a release agent, a well-known release agent can be used, and it is preferable to select a release agent so that the remaining amount of the adhesive member on the separator is small. For example, a silicone-based release agent and a fluorine-based release agent can be used.

(decorative layer)

The decorative layer is, for example, between the window member and the touch sensor or the touch sensor-equipped panel member (more specifically, the first touch-sensor-equipped panel member or the second touch-sensor-equipped panel member) to adhere to either layer Configuration of the way components contact. For example, the decorative layer may be provided on any of the surfaces including: the surface on the first member side of the window member, the first laminate side of the first member, or the first touch sensor-equipped panel member side (or The surface on the 1st separator side); When the 2nd member is an optical film, it is the surface on the 3A member side (or the 3B member side) of a 2nd member. Moreover, when at least one of the inside of a 1st member and the inside of a 2nd member contains an adhesive member, a decorative layer may be arrange|positioned so that it may contact this adhesive member. The decoration layer is usually provided in a frame-like pattern on the outer periphery of the display portion on which the image is to be displayed, and makes it impossible to visually recognize the lead-out wiring of the driving element or the touch sensor from the outside. However, the shape of the decorative layer is not limited to a frame shape, and may be a shape capable of shielding a lead wire or the like.

For the decorative layer, in addition to not reflecting the light from the visible side, it is also required to shield the light from the side opposite to the visible side. As such a decorative layer, for example, an ink layer, a metal thin film, or a thin film containing metal fine particles may be formed. The film containing metal fine particles, for example, contains metal fine particles and a binder resin. The decoration layer may be a single-layer structure or a laminated structure. The decorative layer of the laminated structure may be, for example, a laminated body of at least two selected from the group consisting of an ink layer, a metal thin film, and a thin film containing metal particles. The laminate also includes a laminate of two or more ink layers with different compositions, two or more metal thin films with different compositions, or two or more thin films containing metal fine particles with different compositions.

The thickness of the decorative layer is, for example, 20 μm or less, and may be 15 μm or less. The thickness of the decorative layer is preferably 10 μm or less, and may be 8 μm or less or 5 μm or less, from the viewpoint of easily eliminating the height difference caused by the decorative layer using the adhesive member. Moreover, when the thickness of a decoration layer is such a range, it becomes easy to ensure the high bending resistance of a flexible image display device and an optical laminated body. The thickness of the decoration layer is preferably 10 nm or more, more preferably 30 nm or more, or 50 nm or more, from the viewpoint of securing a higher shielding effect of the lead-out wiring. The above-mentioned upper limit value and lower limit value can be arbitrarily combined.

The decorative layer can be formed, for example, by applying a coating agent containing the constituent components of the decorative layer to the surface of a member or layer (excluding the adhesive member) in contact with the decorative layer. For example, the decorative layer can be formed by applying a coating agent containing the constituent components of the decorative layer to any of the surfaces including: the surface on the first member side of the window member; the first laminate of the first member The surface on the body side or the first panel member with touch sensor side (or the first spacer side); when the second member is an optical film, the 3A member side (or the 3B member side) of the second member s surface. In addition, the decorative layer can also be formed by depositing constituent components on the surface of a member or layer (excluding the adhesive member) in contact with the decorative layer by a vapor phase method. For example, the decorative layer can be formed by depositing constituent components on any of surfaces including: the surface on the first member side of the window member, the first laminate side or the first member of the first member by a vapor phase method. The surface of the panel member side (or the 1st spacer side) with a touch sensor; When the 2nd member is an optical film, it is the 3A member side (or the 3B member side) of a 2nd member. In the case of a metal thin film, in particular, by using a vapor phase method, a decorative layer having a small thickness can be easily formed. As a vapor phase method, a sputtering method, a vacuum vapor deposition method, a chemical vapor deposition (CVD: Chemical Vapor Deposition) method, an electron beam vapor deposition method, etc. are mentioned. Under these circumstances, if the decorative layer is formed on the surface of the layer or the laminate constituting the first member or the second member, the decorative layer can be formed in each member.

A primer layer may also be disposed on the surface of the member or layer (excluding the adhesive member) to which the coating agent is to be applied before coating. For example, when the decorative layer is provided on the surface on the first member side of the window member, a primer layer may be disposed between the decorative layer and the surface on the first member side of the window member. When the decorative layer is provided on the surface of the first member on the side of the first laminate or on the side of the first panel member with touch sensor (or on the side of the first spacer), the decorative layer may be laminated on the first member of the first member. A primer layer is arranged between the surfaces on the body side or the first panel member with touch sensor side (or the first spacer side). The undercoat layer contains, for example, at least one selected from the group consisting of metal compounds (metal oxides, metal nitrides, metal carbides, metal sulfides, etc.) and resin materials. The primer layer is preferably transparent.

It is preferable that the thickness of the primer layer is small, from the viewpoint that not only the height difference of the decorative layer can be easily absorbed by the adhesive member, but also the influence of the optical properties caused by the primer layer can be easily suppressed. The thickness of the undercoat layer is, for example, 500 nm or less, preferably 100 nm or less or 30 nm or less.

The flexible image display device and the optical laminate can be produced, for example, by arranging an adhesive member between the members (and between layers constituting the members if necessary) and laminating the constituent members. The order of lamination is not particularly limited.

For example, the window member and the first member may be laminated with the first adhesive member interposed therebetween, and then the first member and the second member may be laminated with the adhesive member interposed therebetween. In addition, after the first member and the second member are stacked with the adhesive member interposed therebetween, the first member and the window member may be stacked with the first adhesive member interposed therebetween. It is preferable to stick each adhesive member to one of the members sandwiching each adhesive member in advance.

In the optical laminate, before laminating the second member and the first member, an adhesive member may be disposed on the surface of the second member on the opposite side to the first member side. In addition, at an appropriate stage after laminating the second member and the first member, the adhesive member may be arranged on the surface of the second member on the opposite side to the first member side. In the optical laminate, before or after disposing the adhesive member on the surface of the second member, the spacer is laminated on the adhesive member disposed on the surface of the second member opposite to the first member side.

The flexible image display device can be produced by preliminarily producing an optical laminate, peeling off the 3B member (more specifically, a spacer) from the optical laminate, and affixing the exposed adhesive member to the 3A member. Fabrication of a flexible image display device. In addition, after laminating the 3A member and the second member with the adhesive member interposed therebetween, the first member may be stacked on the second member with the adhesive member interposed therebetween. Then, the window member was laminated on the first member with the adhesive member interposed therebetween, thereby producing an image display device. Alternatively, a laminate of the 3A member and the second member, and a laminate of the window member and the first member may be prepared in advance, and these laminates may be prepared in a state where the adhesive member is sandwiched between the first member and the second member. cascading.

These manufacturing methods are merely examples, and are not limited thereto. When a flexible image display device or an optical laminated body is provided with the panel member with a touch sensor, it can also manufacture by laminating|stacking each member according to these manufacturing methods.

FIG. 1 is a schematic cross-sectional view of a flexible image display device according to a first embodiment of the above aspect of the present invention. The flexible image display device 1 includes a laminate of a window member 11 , an optical film 12 as a first member, a touch sensor 13 as a second member, and a panel member 14 as a 3A member. The laminate of the touch sensor 13 as the second member and the panel member 14 as the 3A member corresponds to the first laminate L. The optical film 12 and the window member 11 are laminated in a state in which an adhesive member (first adhesive member) 21 is sandwiched between the optical film 12 and the window member 11 . The touch sensor 13 is laminated on the window member 11 with the optical film 1 interposed therebetween. An adhesive member 22 is interposed between the optical film 12 and the touch sensor 13 . The panel member 14 is laminated on the window member 11 in three layers with the optical film 12 and the touch sensor 1 interposed therebetween. An adhesive member 23 is interposed between the touch sensor 13 and the panel member 14 . The laminated body of the structure other than the panel member 14 and the spacer (not shown) in FIG. 1 corresponds to an optical laminated body.

The window member 11 includes, for example, a window film 111 and a hard coat layer 112 laminated on the window film 111 . The hard coat layer 112 is provided on the side opposite to the first member (optical film 12 ) side of the window member 11 (more specifically, the surface of the window film 111 on the opposite side to the first member side). Here, the product of the elastic modulus E0 of the window member 11 and the thickness T0 satisfies E0×T0≦0.32.

The optical film 12 includes a polarizing plate composed of a polarizer 121 and a protective film 122 , and a retardation layer 123 . The retardation layer 123 is disposed on the side of the touch sensor 13 serving as the second member, and is laminated on the side of the polarizer 121 of the polarizing plate.

The touch sensor 13 includes a transparent conductive layer 131 and a transparent film (touch sensor film) 132 as a transparent base material. The touch sensor 13 is arranged so that its transparent conductive layer 131 is in contact with the adhesive member 22 arranged between the optical film 12 and the touch sensor 13 .

The panel member 14 includes an organic EL panel (organic EL display) 141 and a film sealing layer 142 . The panel member 14 is arrange|positioned so that the film sealing layer 142 may contact the adhesive member 23 arrange|positioned between the touch sensor 13 and the panel member 14.

In the flexible image display device 1 and the optical laminate, E0×T0≦0.32 is controlled, and the thickness of the first adhesive member 21 is within the above-mentioned range. In addition, it is controlled so that the thickness of at least one layer of adhesive members other than the first adhesive member 21 falls within the above-mentioned range. Thereby, high pencil hardness can be ensured on the surfaces of the flexible image display device 1 and the optical laminate on the window member 11 side, and high adhesion between the laminated members can be ensured even if the flexible image display device is repeatedly bent in a high-temperature environment Connectivity.

In FIG. 1 , a frame-shaped decorative layer 30 is provided on the surface of the first member (optical film 12 ) on the second member (touch sensor 13 ) side. In this case, by setting the thickness of the adhesive member (specifically, the adhesive member 22 ) with which the decorative layer 30 contacts to 10 μm or more, the height difference caused by the decorative layer 3 can be effectively absorbed.

In addition, although the case where the decoration layer 30 is formed in the surface of the touch sensor 13 side of the optical film 12 is shown in FIG. 1, it is not limited to this case. The decorative layer 30 may be provided on the surface of the window member 11 on the side of the first member (optical film 12 ).

In FIG. 1, the case where the 1st member is the optical film 12, the 2nd member is the touch sensor 13, and the 3A member is a panel member is shown. However, it is not limited to this case, and the touch sensor as the first member may be laminated on the window member 11 , and the optical film as the second member may be laminated on the window member 11 via the touch sensor. Moreover, as a 3A member, the laminated body containing the above-mentioned panel member can be used.

2 is a schematic cross-sectional view of a flexible image display device according to a second embodiment. The flexible image display device 101 includes a window member 11 , an optical film 12A as a first member, and a laminate of the first laminate L. The 1st laminated body L has the structure which laminated|stacked the optical film 12B which is a 2nd member, and the 2nd panel member 15B with a touch sensor which is a 3A member. An adhesive member 21 is interposed between the window member 11 and the optical film 12A. The adhesive member 22 is interposed between the optical film 12A and the first laminate L, and the adhesive member 23 is interposed between the optical film 12B and the second touch sensor-equipped panel member 15B. Except for the structure of the optical film 12A and the 1st laminated body L which are 1st members, it is the same as that of 1st Embodiment, and the description of 1st Embodiment can be referred.

The optical film 12A is a polarizer composed of a polarizer 121 and a protective film 122 . In the optical film 12A, the polarizer 121 is arranged on the side of the adhesive member 22 (in other words, the side opposite to the window member 11 ). The optical film 12B is a laminate of the two retardation layers 123 and 124 .

About 2nd Embodiment, for example, the laminated body of the structure other than the 2nd panel member with touch sensor 15B and the spacer (2nd spacer) which is not shown in figure corresponds to an optical laminated body.

3 is a schematic cross-sectional view of a flexible image display device according to a third embodiment. The flexible image display device 201 is provided with the laminated body of the window member 11, the optical film 12 which is a 1st member, and 15 A of 1st panel members with a touch sensor. An adhesive member 21 is interposed between the window member 11 and the optical film 12 . The adhesive member 22 is interposed between the optical film 12 and the first panel member with touch sensor 15A. It is the same as that of 1st Embodiment except that the 1st panel member with a touch sensor 15A was arrange|positioned instead of the 1st laminated body L. Regarding the configurations other than the first panel member with touch sensor 15A, the description of the first embodiment can be referred to.

About 3rd Embodiment, the laminated body of the structure other than the 1st panel member with touch sensor 15A and the spacer (1st spacer) which is not shown in figure corresponds to an optical laminated body.

In both the second embodiment and the third embodiment, it is controlled so that E0×T0≦0.32, and the thickness of the first adhesive member 21 is within the above-mentioned range. In addition, it is controlled so that the thickness of at least one layer of adhesive members other than the first adhesive member 21 falls within the above-mentioned range. As a result, high pencil hardness can be ensured on the surfaces of the flexible image display devices 101 and 201 and the optical laminate on the window member 11 side, and even if the flexible image display device is repeatedly bent in a high-temperature environment, the adhesion between the laminated members can be ensured. High adhesion.

Example

Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

"Examples 1 to 4 and Comparative Examples 1 to 6"

(1) Preparation of samples for evaluation

A sample for evaluation of the flexible image display device 1 as shown in FIG. 1 was produced by the following method.

(a) Production of the window member 11

As the window member 11, a transparent polyimide film (manufactured by KOLON Corporation, product name "A_50_O", thickness 50 μm) as the window film 111 provided with an acrylic hard coat layer 112 (thickness 10 μm) on one side of the film was used member. The hard coat layer 112 is formed using a coating agent for hard coat layers. More specifically, first, a coating agent was applied on one side of a transparent polyimide film to form a coating layer, and the coating layer and the transparent polyimide film were heated at 90° C. for 2 minutes. Next, the hard coat layer 112 was formed by irradiating the coating layer with ultraviolet rays at a cumulative light amount of 300 mJ/cm ² using a high pressure mercury lamp. In this way, the window member 11 is produced. The elastic modulus E0 of the window member obtained by the aforementioned method was 4.7 GPa, and E0×T0 (=0.06 mm)=0.28.

In addition, the coating agent for hard coat layers was prepared as follows: 100 parts by mass of polyfunctional acrylate (manufactured by Aica Kogyo Co., Ltd., product name "Z-850-16") as matrix resin , 5 parts by mass of a leveling agent (manufactured by DIC, trade name: GRANDIC PC-4100), and 3 parts by mass of a photopolymerization initiator (manufactured by Ciba Japan, trade name: IRGACURE 907), and mixed with methyl isobutyl The ketone was diluted so that the solid content concentration was 50% by mass.

Regarding Comparative Example 6, a sample having only the window member 11 was produced.

(b) Production of the optical film 12

The optical film 12 was produced in the following procedure.

(Manufacture of polarizer 121)

As a thermoplastic resin base material, an amorphous polyethylene terephthalate film (100 μm in thickness) containing 7 mol % of isophthalic acid units was prepared, and the discharge amount was 58 W/m ² ·min. Corona discharge treatment was carried out on its surface.

Acetoacetyl-modified polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: GOHSEFIMER Z200 (average degree of polymerization 1200, degree of saponification 98.5 mol %, degree of acetoacetylation 5 mol %)) added with 1 mass % was prepared. For polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2%), an aqueous coating liquid containing 5.5 mass % of polyvinyl alcohol (PVA)-based resin was prepared.

The coating liquid was applied to the surface of the base material so that the film thickness after drying might be 12 μm, and it was dried by hot air in an atmosphere of 60° C. for 10 minutes, thereby producing a product with A laminate of layers of PVA-based resin.

First, the obtained laminate was subjected to free-end stretching (assisted stretching in an atmosphere) to 1.8 times in air at 130° C., thereby producing a stretched laminate. Next, the stretched laminate was immersed in an aqueous solution of boric acid insolubilization at a liquid temperature of 30° C. for 30 seconds to insolubilize the PVA layer in which the PVA molecules contained in the stretched laminate were oriented. The boric acid-insolubilized aqueous solution in this step is a boric acid aqueous solution having a boric acid content of 3 parts by mass with respect to 100 parts by mass of water. By dyeing the obtained stretched laminate, a colored laminate was produced. The colored laminate is formed by placing the stretched laminate in a dyeing solution containing iodine and potassium iodide at a liquid temperature of 30° C. so that the transmittance of the monomer constituting the PVA layer of the finally produced polarizer becomes 40 to 44% The PVA layer contained in the stretched laminate was dyed with iodine by dipping for a given time. In this step, the dyeing solution is an aqueous solution containing iodine and potassium iodide (iodine concentration: 0.1 to 0.4 mass %, potassium iodide concentration: 0.7 to 2.8 mass %, iodine to potassium iodide concentration ratio: 1:7). Next, the process of performing a crosslinking process on the PVA molecules of the PVA layer to which iodine is adsorbed is performed by immersing the colored laminate in a 30° C. boric acid crosslinking aqueous solution for 60 seconds. The boric acid crosslinking aqueous solution in this step is an aqueous solution containing boric acid and potassium iodide (boric acid content: 3 parts by mass relative to 100 parts by mass of water, potassium iodide content: 3 parts by mass relative to 100 parts by mass of water).

The obtained colored laminate was stretched to 3.05 times in a boric acid aqueous solution at a stretching temperature of 70° C. in the same direction as the above-mentioned in-air stretching (boric acid water stretching) to obtain a final stretch ratio. It is 5.50 times the laminated body. The obtained laminate was taken out from the boric acid aqueous solution, and the boric acid adhering to the surface of the PVA layer was washed with a potassium iodide aqueous solution (potassium iodide content: 4 parts by mass relative to 100 parts by mass of water). The laminated body after washing was dried by a drying step using hot air at 60°C. The thickness of the polarizer 121 contained in the laminated body after drying was 5 micrometers.

(Formation of protective film 122 )

As the protective film 122, an acrylic film obtained by extrusion molding a methacrylic resin pellet having a glutarimide ring unit into a film shape and then stretching was used. The thickness of the protective film was 40 μm. The protective film 122 and the polarizer 121 were bonded together using an adhesive (active energy ray-curable adhesive), and ultraviolet rays were irradiated under the following conditions to cure the adhesive, thereby producing a polarizing plate.

Gallium-encapsulated metal halide lamp: Fusion UV Systems. Inc., trade name "LightHAMMER10"

Valve: V valve

Peak illuminance: 1600mW/cm ²

Cumulative exposure: 1000mJ/cm ² (wavelength 380～440nm)

The adhesive was prepared by mixing the following components in such a ratio that their content in 100% by mass of the adhesive became the following value, and stirring at 50°C for 1 hour.

Hydroxyethylacrylamide...11.4% by mass

Tripropylene glycol diacrylate...57.1% by mass

Acryloylmorpholine...11.4% by mass

2-acetoacetoxyethyl methacrylate...4.6% by mass

Acrylic polymer (ARUFON UP-1190, manufactured by Toagosei Co., Ltd.)...11.4% by mass

2-Methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one...2.8% by mass

Diethylthioxanthone...1.3% by mass

(Fabrication of retardation layer 123 )

As the retardation layer 123, a retardation film including two layers of a retardation layer for a quarter-wave plate and a retardation layer for a half-wave plate in which the liquid crystal material was oriented and immobilized was used. As a material for forming the retardation layer for a half-wave plate and the retardation layer for a quarter-wave plate, a polymerizable liquid crystal material (manufactured by BASF, trade name Paliocolor LC242) showing a nematic liquid crystal phase was used. The retardation layer 123 is produced with reference to the descriptions in paragraphs [0118] to [0120] of JP-A No. 2018-28573.

(Production of Optical Film 12 )

Using the above-mentioned adhesive (active energy ray-curable adhesive), the polarizing plate obtained above and the retardation layer 123 were continuously bonded together by a roll-to-roll method. At this time, the lamination was performed so that the axis angle between the slow axis and the absorption axis would be 45°. The optical film 12 was produced as described above. The elastic modulus E1 of the optical film obtained by the method described above was 4.8 GPa, and E1×T1 (=0.05 mm)=0.24.

(c) Formation of the decorative layer

On the surface of the optical film 12 on the touch sensor 13 side, a frame-shaped black ink layer (width 15 mm, thickness 5 μm) was provided as a decorative layer 30 by screen printing. As the black ink, INQ-HF979 manufactured by Imperial Ink Co., Ltd. was used.

(d) Preparation of adhesive

Adhesives (a1) to (a3) for producing the adhesive members 21 to 23 were prepared in the following procedure.

(a1) Acrylic adhesive 1: Acrylic adhesive composition obtained in the following procedure

(Preparation of Acrylic Polymer Solution)

A monomer mixture containing 94.9 parts by mass of butyl acrylate, 5 parts by mass of acrylic acid, and 0.1 part by mass of 2-hydroxyethyl acrylate was added to a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube, and a condenser. With respect to 100 parts by mass of the monomer mixture, 0.1 part by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator was added together with ethyl acetate. While slowly stirring the obtained mixture, nitrogen gas was introduced and replaced with nitrogen gas. Next, the liquid temperature in the flask was maintained at around 55°C, and a polymerization reaction was performed for 7 hours. Ethyl acetate was added to the obtained reaction liquid, the concentration of the polymer component was adjusted to 30% by mass, and a solution of the acrylic polymer A1 having a weight average molecular weight of 1,600,000 was prepared.

(Preparation of Acrylic Adhesive 1)

With respect to 100 parts by mass of the polymer component of the solution of the acrylic polymer A1, 0.1 isocyanate-based crosslinking agent (trade name: Takenate D110N, trimethylolpropane xylylene diisocyanate, manufactured by Mitsui Chemicals Co., Ltd.) was mixed Parts by mass, peroxide-based crosslinking agent (benzoyl peroxide (trade name: NYPER BMT, manufactured by NOF Corporation)) 0.3 mass part, and silane coupling agent (trade name: KBM403, Shin-Etsu Chemical Co., Ltd. 0.08 parts by mass, whereby an acrylic adhesive 1 was prepared.

(a2) Acrylic adhesive 2: Acrylic adhesive composition obtained in the following procedure

(Preparation of Acrylic Polymer Solution)

A monomer mixture containing 94.9 parts by mass of butyl acrylate, 5 parts by mass of acrylic acid, and 0.1 part by mass of 2-hydroxyethyl acrylate was added to a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube, and a condenser. With respect to 100 parts by mass of the solid content of the monomer mixture, 0.1 part by mass of 2,2'-azobisisobutyronitrile as a polymerization initiator was added together with ethyl acetate. While slowly stirring the obtained mixture, nitrogen gas was introduced and replaced with nitrogen gas. Next, the liquid temperature in the flask was maintained at around 55°C, and a polymerization reaction was performed for 7 hours. Ethyl acetate was added to the obtained reaction liquid, the concentration of the polymer component was adjusted to 30% by mass, and a solution of the acrylic polymer A2 having a weight average molecular weight of 2 million was prepared.

(Preparation of Acrylic Adhesive 2)

With respect to 100 parts by mass of the polymer component of the solution of the acrylic polymer A2, 0.6 part by mass of an isocyanate-based crosslinking agent (trade name: Coronate L, trimethylolpropane toluene diisocyanate, manufactured by Nippon Polyurethane Industry Co., Ltd.), Acrylic adhesive 2 was prepared with 0.08 parts by mass of a silane coupling agent (trade name KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.).

(a3) Acrylic adhesive 3: Acrylic adhesive composition obtained in the following procedure

(Preparation of Acrylic Oligomers)

60 parts by mass of dicyclopentyl methacrylate and 40 parts by mass of methyl methacrylate as monomer components, 3.5 parts by mass of α-thioglycerol as a chain transfer agent, and 100 parts by mass of toluene as a polymerization solvent were mixed , and stirred at 70 °C for 1 hour in a nitrogen atmosphere. Next, 0.2 parts by mass of 2,2'-azobisisobutyronitrile as a thermal polymerization initiator was charged, and after reacting at 70°C for 2 hours, the temperature was raised to 80°C, and the reaction was conducted for 2 hours. Then, the reaction liquid was heated to 130 degreeC, and the toluene, the chain transfer agent, and the unreacted monomer were dried and removed, and the solid acrylic oligomer was obtained. The weight average molecular weight of the acrylic oligomer was 5100, and the glass transition temperature (Tg) was 130°C.

(Preparation of Prepolymer Composition)

43 parts by mass of lauryl acrylate, 44 parts by mass of 2-ethylhexyl acrylate, 6 parts by mass of 4-hydroxybutyl acrylate, 7 parts by mass of N-vinyl-2-pyrrolidone, and BASF as a photopolymerization initiator 0.015 parts by mass of "Irgacure 184" manufactured by the company was mixed, irradiated with ultraviolet rays, and polymerized to obtain a prepolymer composition (polymerization rate: about 10%).

(Preparation of Acrylic Adhesive 3)

To 100 parts by mass of the above-mentioned prepolymer composition were added 0.07 part by mass of 1,6-hexanediol diacrylate, 1 part by mass of the above-mentioned acrylic oligomer, and a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd. "KBM403J") 0.3 parts by mass, and mixed uniformly, whereby an acrylic adhesive 3 was prepared.

(e) Formation of adhesive layer

Using the adhesive prepared in (d) above (the adhesive shown in Table 1), the adhesive layer for forming each layer in the adhesive members 21 to 23 was formed. More specifically, the adhesives shown in Table 1 were uniformly applied to the release film using a spray coater, and dried in an air circulation type constant temperature oven at 155° C. for 2 minutes to form a surface of the release film. adhesive layer. As a release film, a 38-micrometer-thick polyethylene terephthalate film (transparent base material, separator) treated with a silicone-based release agent was used. The thickness of the adhesive layer was adjusted according to the coating amount of the adhesive so that the thicknesses of the respective adhesive members in the samples became the values in Table 1.

(f) Production of laminated body

Each member fabricated above is cut to a given size as required. The pressure-sensitive adhesive layer was transferred from the release film to one of the members sandwiching the respective pressure-sensitive adhesive members, and the respective members were laminated with the pressure-sensitive adhesive layer sandwiched therebetween, and were pressed together with a hand roll. In this way, a sample for evaluation in which each member was laminated by an adhesive member was produced. In addition, as the touch sensor 13 and the panel member 14, the transparent polyimide film (made by KOLON Corporation, product name "A_50_O", thickness 50 micrometers) was used as a dummy, respectively. In addition, the elastic modulus E2 (or E3) of the transparent polyimide film calculated|required by the method mentioned above is 6GPa, and E2 (or E3)*T2 (or T3)=0.3.

(2) Evaluation

(a) Storage modulus of bonded member

The storage elastic modulus of each adhesive member was calculated|required by the method mentioned above. The storage elastic modulus of the adhesive member using each acrylic adhesive is as follows.

Adhesion member using acrylic adhesive 1 (a1): 0.08MPa

Adhesion member using acrylic adhesive 2 (a2): 0.12MPa

Adhesion member using acrylic adhesive 3 (a3): 0.03MPa

(b) Pencil hardness test

The sample for evaluation was placed on a glass plate, and the pencil hardness of the surface on the side of the window member 11 (the surface of the hard coat layer 112 ) was measured.

Regarding Comparative Example 6, the pencil hardness of the surface of the hard coat layer 112 was measured using a sample having only the window member 11 .

(c) Adhesion (flexibility)

The sample for evaluation obtained above was cut out in a strip shape of 100 mm×20 mm with the direction of the absorption axis of the polarizer as the long side. The cut out sample was set in a no-load U-shaped expansion test machine (“Small Desktop Durability Tester DLMD111LHA” and “U-shaped expansion test jig” manufactured by Yuasa System Equipment Co., Ltd.) so that the window member side became the inner side of the curve, and The bending test was performed under the following conditions.

Environmental conditions: 60°C or 25°C, 55%RH

Test speed: 60rpm

Bending radius: R3

Bending times: 100,000 times

The state of peeling of the bent portion of the sample after the test was visually observed and evaluated according to the following criteria.

A: No peeling occurred between the laminated members.

B: Peeling was observed between the laminated members.

Table 1 shows the results of Examples 1 to 4 and Comparative Examples 1 to 6. In Table 1, Examples 1-4 are E1-E4, and Comparative Examples 1-6 are R1-R6.

[Table 1]

As shown in Table 1, in the case of having only the window member, a high pencil hardness (R6) of 4H was obtained on the surface on the side of the hard coat layer. However, when another member is laminated through the adhesive member, the pencil hardness of the surface on the side of the window member (specifically, the surface on the side of the hard coat layer) may be B and significantly decrease (R2 and R3). On the other hand, when the thickness of the 1st adhesive member is 10 micrometers or less, the fall of pencil hardness can be suppressed on the surface of the window member side, and high pencil hardness (E1-E4, R4, and R5) can be ensured. However, even if the thickness of the first adhesive member is 10 μm or less, when the total thickness of the adhesive members other than the first adhesive member is less than 18 μm, peeling occurs between the laminated members in a high temperature environment (60° C.). , cannot ensure high adhesion (R4 and R5). On the other hand, if the thickness of the first adhesive member is 10 μm or less, and the thickness of at least one layer other than the first adhesive member is 18 μm or more, both high pencil hardness and adhesion in a high temperature environment can be achieved. Connectivity. In addition, in the bending test at 25 degreeC, peeling did not generate|occur|produce in Examples 1-4 and Comparative Examples 1-5, and high adhesiveness was ensured.

"Examples 5 to 6 and Comparative Examples 7 to 10"

Samples for evaluation of the flexible image display device 201 shown in FIG. 3 were produced according to Examples 1 to 4. As a mock sample of the first panel member with touch sensor 15A, a transparent polyimide film (manufactured by KOLON Corporation, product name "A_50_O", thickness of 50 μm) as a mock sample.

For the formation of the pressure-sensitive adhesive layer, the pressure-sensitive adhesives (the pressure-sensitive adhesives shown in Table 2) prepared in the same manner as in Examples 1 to 4 were used. The thickness of the adhesive layer was adjusted according to the coating amount of the adhesive so that the thicknesses of the respective adhesive members in the samples reached the values in Table 2.

The obtained samples were used for evaluation in the same manner as in Examples 1 to 4.

Table 2 shows the results of Examples 5 to 6 and Comparative Examples 7 to 10. In Table 2, Examples 5-6 are E5-E6, and Comparative Examples 7-10 are R7-R10. Table 2 also shows the results of Comparative Example 6 (R6).

[Table 2]

As shown in Table 2, in the case of having only the window member, the pencil hardness of the surface on the side of the hard coat layer was 4H, which was very high (R6). However, when it is laminated|stacked with another member via an adhesive member, the pencil hardness is B and it may fall significantly (R8). On the other hand, if the thickness of the 1st adhesive member is 10 micrometers or less, the fall of pencil hardness can be suppressed on the surface of the window member side, and high pencil hardness (E5-E6) can be ensured. In addition, even if the thickness of the first adhesive member is 10 μm, when the total thickness of the adhesive members other than the first adhesive member is less than 18 μm, peeling occurs between the laminated members in a high temperature environment (60° C.). High adhesion cannot be ensured (R9 and R10). On the other hand, if the thickness of the first adhesive member is 10 μm or less, and the thickness of at least one layer other than the first adhesive member is 18 μm or more, both high pencil hardness and adhesion in a high temperature environment can be achieved. connectivity (E5 and E6). In addition, in Examples 5-6 and Comparative Examples 7-10, peeling of the bending part in a bending test was not confirmed, and favorable adhesiveness was able to be ensured.

The presently preferred embodiments of the present invention have been described above, but such disclosures are not to be construed as limiting. Those skilled in the art in the technical field to which the present invention pertains should be able to understand various modifications and alterations without error by reading the above disclosure. Therefore, all modifications and changes can be construed as being included in the appended claims without departing from the true spirit and scope of the present invention.

Claims (10)

1. A flexible image display device is provided with:

a window component,

A1 st member laminated on the window member,

A1 st laminate or a1 st touch sensor-equipped panel member laminated on the window member with the 1 st member interposed therebetween, and

a multi-layer adhesive member, the adhesive member,

wherein,

the 1 st laminate is a laminate of a2 nd member and a 3A th member, the 2 nd member being laminated on the window member via the 1 st member, the 3A th member being laminated on the window member via the 1 st member and the 2 nd member,

when the flexible image display device comprises the 1 st laminate,

one of the 1 st and 2 nd members is an optical film, and the other is an optical film or a touch sensor,

the 3A member comprises at least a panel member,

the multilayered adhesive member includes at least three layers disposed between the window member and the 1 st member, between the 1 st member and the 2 nd member, and between the 2 nd member and the 3 rd member,

when the flexible image display device includes the 1 st touch sensor-equipped panel member,

the 1 st component is an optical film,

the multilayered adhesive member includes at least two layers disposed between the window member and the 1 st member and between the 1 st member and the 1 st touch sensor-equipped panel member,

e0 XT 0 is not more than 0.32 when E0 is a modulus of elasticity (GPa) of the window member and T0 is a thickness (mm) of the window member,

the thickness of the 1 st adhesive member disposed between the window member and the 1 st member satisfies a condition of 10 μm or less,

the thickness of at least one layer of the multi-layer adhesive member other than the 1 st adhesive member satisfies a condition of 18 μm or more.

2. The flexible image display device according to claim 1, provided with the 3A means,

one of the 1 st and 2 nd members is the optical film, and the other is the touch sensor.

3. The flexible image display device according to claim 1 or 2,

the multi-layered adhesive member further comprises at least one layer disposed within the 3A member.

4. The flexible image display device of claim 1,

the 3A member comprises a2 nd touch sensor-equipped panel member,

the 1 st member and the 2 nd member are the optical film, respectively.

5. The flexible image display device according to any one of claims 1 to 4,

the thickness of each layer of the multi-layer adhesive member satisfies a condition of 3 [ mu ] m or more.

6. The flexible image display device according to any one of claims 1 to 5,

the hardness of the window member side is harder than that of F according to the pencil hardness test specified in JIS K5600-5-4: 1999.

7. The flexible image display device according to any one of claims 1 to 6,

each layer of the multilayered adhesive member satisfies a condition of 1MPa or less in storage modulus at 25 ℃.

8. The flexible image display device according to any one of claims 1 to 7,

the window member is provided with a hard coating,

the hard coat layer is provided at least on a side of the window member opposite to the 1 st adhesive member side.

9. An optical laminate used for the flexible image display device according to any one of claims 1 to 8,

the optical laminate comprises:

a window component,

A1 st member laminated on the window member,

A2 nd laminate or a1 st separator laminated on the window member with the 1 st member interposed therebetween, and a plurality of adhesive members,

wherein,

the 2 nd laminate is a laminate of a2 nd member and a 3B nd member, the 2 nd member being laminated on the window member via the 1 st member, the 3 rd member being laminated on the window member via the 1 st member and the 2 nd member,

when the optical laminate comprises the 2 nd laminate,

one of the 1 st and 2 nd members is an optical film, and the other is an optical film or a touch sensor,

the 3B member includes at least a2 nd spacer,

the multilayered adhesive member includes at least three layers disposed between the window member and the 1 st member, between the 1 st member and the 2 nd member, and between the 2 nd member and the 3 rd member,

when the optical laminate includes the 1 st spacer,

the 1 st component is an optical film,

the multilayered adhesive member includes at least two layers disposed between the window member and the 1 st member and between the 1 st member and the 1 st spacer,

e0 XT 0 is not more than 0.32 when E0 is a modulus of elasticity (GPa) of the window member and T0 is a thickness (mm) of the window member,

the thickness of the 1 st adhesive member disposed between the window member and the 1 st member satisfies a condition of 10 μm or less,

the thickness of at least one layer of the multi-layer adhesive member other than the 1 st adhesive member satisfies a condition of 18 μm or more.

10. The optical laminate according to claim 9, which comprises the 3B-member,

one of the 1 st and 2 nd members is the optical film, and the other is the touch sensor.

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