TW202214037A - Display device and base material laminate - Google Patents

Abstract

The problem of the present invention aims at a bendable display device to realize a display device that can suppress the layer or member with fragile anti-flexibility from breaking while facing the bending of the display device. The display device as a solution means is bendable and has: an optical film member, a first adhesive layer, a window member, a second adhesive layer and a laminated structure body. Wherein, the window member is laminated on one surface of the optical film member via the first adhesive layer, and the laminated structure body is laminated on another surface of the optical film member via the second adhesive layer and includes a panel member. The display device is characterized by: the surface of the laminate structure body at the second adhesive layer side having a layer that is more easily broken than the window member and the optical film member while performing the bending deformation; making the relation of the following equations (1), (2) and (3) be established between the following strain differences A, A', B and B', so that the extension rate of the easy-to-break layer after performing the bending deformation is suppressed to be a value smaller than the breaking extension rate: bending the display device at an angle of 180 DEG in a manner of the window member facing outwards, and allowing the bending deformation to be formed under the state of being an angle of 180 DEG, when the interval between the parallel and opposite the outermost surfaces of the display device is 4mm, the difference between the strain of the direction generated by one surface of the optical film member being orthogonal to the bending radius direction and the strain of the direction generated by the surface of the window member facing the surface of the first adhesive layer being orthogonal to the bending radius direction is determined to be A; using the outside and inside after performing the bending deformation and the same manner after allowing the display device to be bent and deformed so as to bend the optical film member and the window member at an angle of 180 DEG under the state of respective single-layer, and allowing the bending deformation to be formed under the state of bending at an angle of 180 DEG, when the interval between the parallel and opposite outermost surfaces of each optical film member and each window member is 4mm, the difference between the strain of the direction generated by the outside surface of the optical film member being orthogonal to the bending radius direction and the strain of the direction generated by the inside surface of the window member being orthogonal to the bending radius direction is determined to be A'; bending the display device at an angle of 180 DEG in a manner of the window member facing outwards and allowing the bending deformation to be formed under the state of bending at an angle of 180 DEG, when the interval between the parallel and opposite outermost surfaces of the display device is 4mm, the difference between the strain of the direction generated by another surface of the optical film member being orthogonal to the bending radius direction and the strain of the direction generated by the surface of the second adhesive layer facing the surface of the laminated structure body being orthogonal to the bending radius direction is determined to be B; and using the outside and inside after performing the bending deformation and the same manner after allowing the display device to be bent and deformed so as to bend the optical film member and the laminated structure body at an angle of 180 DEG under the state of respective single-layer, and allowing the bending deformation to be formed under the state of bending at an angle of 180 DEG, when the interval between the parallel and opposite outermost surfaces of each optical film member and each laminated structure body is 4mm, the difference between the strain of the direction generated by the inside surface of the optical film member being orthogonal to the bending radius direction and the strain of the direction generated by the outside surface of the laminated structure body being orthogonal to the bending radius direction is determined to be B'. 0.3 < A/A' < 1.2 (1) B/B' < 1.7A/A'-0.15 (2) 0 < B/B' < 1.25 (3).

Description

Display device and substrate laminate

The present invention relates to a display device configured to be foldable and a substrate laminate used for the display device.

For example, as shown in Patent Document 1, a touch-sensor-integrated organic EL display device is known. Regarding the organic EL display device of Patent Document 1, as shown in FIG. 1 , an optical laminate 920 is provided on the viewing side of the organic EL display panel 901 , and a touch panel 930 is provided on the viewing side of the optical laminate 920 . The optical laminate 920 includes a polarizer 921 and a retardation film 923 having protective films 922 - 1 and 922 - 2 bonded to both surfaces, and the polarizer 921 is provided on the viewing side of the retardation film 923 . In addition, the touch panel 930 has a structure in which the transparent conductive films 916-1 and 916-2 are arranged with the spacer 917 interposed therebetween, and the transparent conductive films 916-1 and 916-2 have substrate films 915-1 and 915- 2 and the structure of the transparent conductive layers 912-1 and 912-2.

On the other hand, realization of a bendable organic EL display device, which is an organic EL display device with better portability, has been expected in recent years. prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2014-157745

The problem to be solved by the invention However, for example, the conventional organic EL display device shown in Patent Document 1 is not designed in consideration of the bending function. As long as the plastic film is used for the organic EL display panel substrate, flexibility can be imparted to the organic EL display panel. However, the transparent conductive layer included in the touch sensor member constituting the conventional organic EL display device, the thin film sealing layer of the organic EL display panel, the hard coat layer provided on the surface of the window member, and other layers with fragile resistance to flexure are The organic EL display device breaks when it is bent.

Therefore, an object of the present invention is to realize a display device that can suppress the breakage of a layer or member having a fragile resistance to bending when facing the display device when it is bent.

means of solving problems One aspect of the present invention provides a display device which is bendable and has: an optical film member, a first adhesive layer, a window member, a second adhesive layer, and a laminated structure, wherein the window member is formed through the first adhesive layer. The laminated layer is on one side of the optical film member, and the laminated structure system is laminated on the other side of the optical film member through the second adhesive layer and includes a panel member; The display device is characterized by: The above-mentioned laminated structure has a layer on the surface on the side of the above-mentioned second adhesive layer that is more likely to be broken than the above-mentioned window member and optical film member when being bent and deformed; The following equations (1), (2), and (3) are established between the following strain differences A, A', B, and B', whereby the elongation of the easily fractured layer after bending deformation is determined by Suppress to a value smaller than the elongation at break: The display device is bent at an angle of 180° with the window member facing outward, and the bending is deformed so that the distance between the parallel opposite outermost surfaces of the display device in the state of being bent at an angle of 180° is 4 mm, the strain in the direction orthogonal to the bending radius direction generated on the aforesaid surface of the optical film member, and the strain in the direction orthogonal to the bending radius direction generated on the surface of the window member facing the first adhesive layer The difference is set to A; The optical film member and the window member were bent at an angle of 180° in the state of each single layer in the same manner as after the display device was bent and deformed at an angle of 180°, and the bending When the distance between the parallel facing outermost surfaces of the optical film member and the window member in a state of being bent at an angle of 180° is 4 mm, the direction of the bending radius generated on the outer surface of the optical film member and the bending radius direction are formed. The difference between the strain in the orthogonal direction and the strain in the direction orthogonal to the bending radius direction generated on the inner surface of the window member is set as A'; The display device is bent at an angle of 180° with the window member facing outward, and the bending is deformed so that the distance between the parallel opposite outermost surfaces of the display device in the state of being bent at an angle of 180° is At 4 mm, the strain in the direction orthogonal to the bending radius direction generated on the other surface of the optical film member, and the direction orthogonal to the bending radius direction generated on the surface of the laminated structure facing the second adhesive layer. The difference in strain is set as B; The optical film member and the laminated structure were bent at an angle of 180° in the state of each single layer in the same manner as after the display device was bent and deformed so that the outer side and the inner side were bent and deformed at an angle of 180°. It is deformed such that when the distance between the parallel opposite outermost surfaces of the optical film member and the laminated structure is 4 mm in a state of being bent at an angle of 180°, the inner surface of the optical film member is deformed and warped. The difference between the strain in the direction perpendicular to the radial direction and the strain in the direction perpendicular to the bending radius direction generated on the outer surface of the laminate structure is defined as B'; 0.3＜A/A’＜1.2 ・・・・(1) B/B’＜1.7A/A’-0.15 ・・・・(2) 0＜B/B’＜1.25 ・・・・(3).

The said window member can be made to have a hard-coat layer on the surface opposite to the said 1st adhesive layer.

The aforementioned optical film member can be a circularly polarizing functional film laminate in which a retardation film is laminated on a polarizing film.

The polarizing film can be a laminate in which a polarizer and a polarizer protective film on at least one side of the polarizer are laminated.

The aforementioned polarizer protective film may be made of an acrylic resin.

The layer which can be more easily broken than the window member and the optical film member is a film sealing layer formed on the surface of the panel member on the side of the second adhesive layer.

The laminated structure may be one in which a film sealing layer is formed on the surface of the panel member on the side of the second adhesive layer, and a third adhesive layer is formed on the surface of the film sealing layer on the opposite side to the panel member. A touch sensor member is laminated, and a transparent conductive layer is formed on the surface of the touch sensor member opposite to the panel member, and the transparent conductive layer is compared with the window member and the optical film. The form of the layer where the member is more easily fractured is laminated on the aforementioned second adhesive layer.

The relationship of the following formula (4) can be further established between the differences A and A' of the aforementioned strains. 0.8＜A/A’ ・・・・(4)

The shear modulus of elasticity of the second adhesive layer can be made larger than the shear modulus of elasticity of the first adhesive layer.

A fourth adhesive layer can be further provided on the surface of the panel member opposite to the second adhesive layer, and a protective member can be provided through the fourth adhesive layer.

The shear modulus of elasticity of the fourth adhesive layer can be made smaller than the shear modulus of elasticity of the second adhesive layer and smaller than the shear modulus of elasticity of the third adhesive layer.

One aspect of the present invention provides a substrate laminate, which is used in the display device and has: the optical film member; the window member, which is laminated on one surface of the optical film member through the first adhesive layer; The control sensor member is laminated on the other side of the optical film member through the second adhesive layer and includes the transparent conductive layer.

Invention effect According to the present invention, for a display device configured to be bendable, it is possible to realize a display device capable of suppressing breakage of a layer or member that is fragile against bending when facing the display device's bending.

Hereinafter, embodiments of the display device of the present invention will be described in detail with reference to the drawings.

[Optical film member] The optical film member used in the display device of the present invention can be a polarizer, a polarizing film, a film such as a protective film formed of a transparent resin material or a retardation film, etc., or a combination of some or all of them, and can be used in particular for polarized light. Thin-film laminates are circularly polarizing functional thin-film laminates in which retardation films are laminated. In addition, the said optical film member does not contain adhesive layers, such as a 1st adhesive layer mentioned later.

The thickness of the aforementioned optical film member is preferably 92 μm or less, preferably 60 μm or less, and more preferably 10 to 50 μm. If it is within the aforementioned range, deflection is not hindered, and it is a preferable aspect. ＜Polarizer＞ The polarizer contained in the optical film member of the present invention can be a polyvinyl alcohol (PVA)-based resin in which iodine has been oriented and stretched by a stretching step such as air stretching (dry stretching) or a boric acid water stretching step.

The manufacturing method of the polarizer is represented by the manufacturing method (monolayer stretching method) described in Japanese Patent Laid-Open No. 2004-341515, which includes a step of dyeing a monolayer of PVA-based resin and a step of stretching. In addition, for example, Japanese Patent Laid-Open No. 51-069644, Japanese Patent Laid-Open No. 2000-338329, Japanese Patent Laid-Open No. 2001-343521, International Publication No. 2010/100917, The production method described in Japanese Patent Laid-Open No. 073563 and Japanese Patent Laid-Open No. 2011-2816 includes a step of stretching a PVA-based resin layer and a resin substrate for stretching in a laminate state, and a step of dyeing. With this production method, even if the PVA-based resin layer is thin, it is supported by the resin substrate for stretching, so that it can be stretched without causing problems such as breakage due to stretching.

The thickness of the aforementioned polarizer is 20 μm or less, preferably 12 μm or less, preferably 9 μm or less, more preferably 1 to 8 μm, and particularly preferably 3 to 6 μm. If it is within the aforementioned range, deflection is not hindered, and it is a preferable aspect.

＜Polarizing film＞ As long as the characteristics of the present invention are not impaired, the polarizer can also be attached with a polarizer protective film (not shown in the drawings) on at least one side through an adhesive (layer). An adhesive can be used for the subsequent treatment of the polarizer and the polarizer protective film. Examples of the adhesive include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, and water-based polyesters. The aforementioned adhesive is generally used as an adhesive composed of an aqueous solution, and generally contains a solid content of 0.5 to 60% by weight. In addition to the above, as the adhesive for the polarizer and the polarizer protective film, an ultraviolet curable adhesive, an electron beam curable adhesive, and the like can be mentioned. The adhesive for electron beam curable polarizing films exhibits good adhesiveness to the above-mentioned various polarizer protective films. Further, the adhesive used in the present invention may contain a metal compound filler. In addition, in this invention, what bonded a polarizer and a polarizer protective film through the adhesive (layer) may be called a polarizing film.

<Retardation film> The optical film member used in the present invention may include a retardation film, and the retardation film may be obtained by extending a polymer film or by orienting and immobilizing a liquid crystal material. In this specification, the retardation film refers to one having birefringence in the plane and/or thickness direction.

The retardation film can be enumerated as antireflection retardation film (refer to Japanese Patent Laid-Open No. 2012-133303 Gazette [0221], [0222], [0228]), and phase difference film for viewing angle compensation (refer to Japanese Patent Laid-Open No. 2012- 133303 Gazette [0225], [0226]), a tilt alignment retardation film for viewing angle compensation (refer to Japanese Patent Laid-Open No. 2012-133303 Gazette [0227]), etc.

The retardation film is not particularly limited as long as it substantially has the above-mentioned functions, such as retardation value, arrangement angle, three-dimensional birefringence, single-layer or multi-layer, and known retardation films can be used.

The thickness of the aforementioned retardation film is preferably 20 μm or less, preferably 10 μm or less, more preferably 1 to 9 μm, and particularly preferably 3 to 8 μm. If it is within the aforementioned range, deflection is not hindered, and it is a preferable aspect.

In the present specification, Re[550] means the in-plane retardation value measured with light having a wavelength of 550 nm at 23°C. Re[550] can be set by the formula: Re[ 550]=(nx-ny)×d. In addition, the slow axis refers to the direction in which the in-plane refractive index becomes the largest.

The in-plane birefringence Δn of nx-ny of the present invention is 0.002-0.2, preferably 0.0025-0.15.

The retardation film is preferably such that the in-plane retardation value (Re[550]) measured with light having a wavelength of 550 nm at 23° C. is larger than the in-plane retardation value (Re[450]) measured with light having a wavelength of 450 nm. A retardation film having such wavelength dispersion properties can exhibit a long-wavelength-like retardation as long as the aforementioned ratio is within this range, and an ideal retardation property can be obtained at each wavelength in the visible region. For example, when used in an organic EL display, a retardation film having such wavelength dependence can be produced as a quarter-wave plate, and a circular polarizer can be produced by laminating it with a polarizing plate, thereby realizing the wavelength dependence of hue. Less neutral polarizers and display devices. On the other hand, when the aforementioned ratio is outside this range, the wavelength dependence of the reflected hue becomes large, and a problem of coloring occurs in the polarizing plate or the display device.

The ratio of Re[550] to Re[450] of the retardation film (Re[450]/Re[550]) is 0.8 or more and less than 1.0, and preferably 0.8 to 0.95.

The retardation film is preferably such that the in-plane retardation value (Re[550]) measured with light with a wavelength of 550 nm at 23° C. is smaller than the in-plane retardation value (Re[650]) measured with light with a wavelength of 650 nm. The retardation film with this wavelength dispersion characteristic has a fixed retardation value in the red region. For example, when it is used in a liquid crystal display device, it can improve the phenomenon of light leakage due to the viewing angle, or the phenomenon that the displayed image is red (also known as the phenomenon of red). redness).

The ratio of Re[650] to Re[550] of the retardation film (Re[550]/Re[650]) is 0.8 or more and less than 1.0, and preferably 0.8 to 097. By making Re[550]/Re[650] into the said range, when the said retardation film is used for an organic EL display, for example, more excellent display characteristics can be acquired.

Re[450], Re[550], and Re[650] can be measured using the product name "AxoScan" manufactured by Axometrics.

In one embodiment, the retardation film of the present invention is produced by extending and orienting a polymer film.

The above-mentioned method of extending the polymer film may adopt any appropriate extending method according to the purpose. The above-mentioned stretching methods suitable for the present invention include, for example, a lateral uniaxial stretching method, a longitudinal and lateral simultaneous biaxial stretching method, and a longitudinal and lateral stepwise biaxial stretching method. Any appropriate stretching machine, such as a tenter stretching machine, a biaxial stretching machine, etc., can be used as a mechanism for stretching. Preferably, the above-mentioned stretching machine is provided with a temperature control mechanism. When heating and stretching, the internal temperature of the stretching machine can be continuously changed, or it can be continuously changed. The step may be performed once or divided into two or more times. The extending direction is preferably in the film width direction (TD direction) or diagonally.

In another embodiment, as the retardation film of the present invention, a retardation layer prepared by orienting and immobilizing a liquid crystal material by lamination can be used. Each retardation layer may be an orientation cured layer of a liquid crystal compound. By using a liquid crystal compound, the difference between nx and ny of the obtained retardation layer can be made much larger than that of the non-liquid crystal material, so the thickness of the retardation layer required to obtain the desired in-plane retardation can be reduced even more many. As a result, the circularly polarizing plate (finally, the organic EL display device) can be made thinner. The term "orientation-cured layer" in this specification refers to a layer in which the liquid crystal compound is oriented in a predetermined direction within the layer, and the orientation state thereof has been fixed. In the present embodiment, it means that the rod-like liquid crystal compound is aligned in the slow axis direction of the retardation layer (surface alignment). As a liquid crystal compound, the liquid crystal compound (nematic liquid crystal) whose liquid crystal phase is a nematic phase is mentioned, for example. As such a liquid crystal compound, for example, a liquid crystal polymer or a liquid crystal monomer can be used. The expression mechanism of the liquid crystallinity of the liquid crystal compound may be lyotropic or thermotropic. Each of the liquid crystal polymer and the liquid crystal monomer may be used alone or in combination.

When the liquid crystal compound is a liquid crystal monomer, the liquid crystal monomer is preferably a polymerizable monomer and a crosslinkable monomer. This is because the alignment state of the liquid crystal monomer can be fixed by polymerizing or crosslinking the liquid crystal monomer. After the liquid crystal monomers are aligned, for example, the above-mentioned alignment state can be fixed by polymerizing or crosslinking the liquid crystal monomers with each other. Here, a polymer is formed by polymerization, and a three-dimensional network structure is formed by cross-linking, but these are non-liquid crystalline. Therefore, the formed retardation layer does not change into a liquid crystal phase, a glass phase, or a crystal phase due to a temperature change, which is peculiar to a liquid crystal compound, for example. As a result, the layer becomes a retardation layer with excellent stability not affected by temperature changes.

The temperature range in which the liquid crystal monomer exhibits liquid crystallinity varies depending on the type. Specifically, the temperature range is preferably 40°C to 120°C, more preferably 50°C to 100°C, and most preferably 60°C to 90°C.

Any appropriate liquid crystal monomer can be used as the above-mentioned liquid crystal monomer. For example, polymerizable mesogenic compounds described in Japanese Patent Application Laid-Open No. 2002-533742 (WO00/37585), EP358208 (US5211877), EP66137 (US4388453), WO93/22397, EP0261712, DE19504224, DE4408171, GB2280445 and the like can be used. Specific examples of the polymerizable mesogen compound include BASF's trade name LC242, Merck's trade name E7, and Wacker-Chem's trade name LC-Silicon-CC3767. The liquid crystal monomer is preferably, for example, a nematic liquid crystal monomer.

The alignment curing layer of the liquid crystal compound can be formed by the following method: performing alignment treatment on the surface of a predetermined substrate, and applying a coating liquid containing the liquid crystal compound on the surface to align the liquid crystal compound in the direction corresponding to the above alignment treatment , and fix the orientation state. In one embodiment, the base material is any suitable resin film, and the orientation curing layer formed on the base material can be transferred to the surface of the polarizer. At this time, the angle formed by the absorption axis of the polarizer and the slow axis of the liquid crystal alignment cured layer was arranged to be 15°. In addition, the retardation of the liquid crystal alignment cured layer was λ/2 (about 270 nm) with respect to the wavelength of 550 nm. In addition, a liquid crystal alignment solidified layer with a wavelength of λ/4 (about 140 nm) relative to a wavelength of 550 nm is formed on the transferable substrate in the same manner as described above, and the absorption axis of the polarizer and the slowness of the 1/4 wavelength plate are formed. It was laminated on the half-wave plate side of the laminate of the polarizer and the half-wave plate so that the angle formed by the axis was 75°.

<Polarizer protective film> As the polarizer protective film made of a transparent resin material used in the display device of the present invention, cycloolefin-based resins such as norbornene-based resins, olefin-based resins such as polyethylene and polypropylene, polyester-based resins, and (meth)acrylic-based resins can be used Wait.

The thickness of the aforementioned polarizer protective film is preferably 5-60 μm, preferably 10-40 μm, more preferably 10-30 μm, and surface treatment layers such as anti-glare layer and anti-reflection layer can be appropriately provided. If it is within the aforementioned range, deflection is not hindered, and it is a preferable aspect. The moisture permeability of the polarizer protective film used in the optical laminate of the present invention is 200 g/m ² or less, preferably 170 g/m ² or less, more preferably 130 g/m ² or less, especially 90 g/m ² or less.

[window widget] The window member is arranged on the outermost surface on the viewing side of the display device in order to prevent damage to the optical film member, the touch sensor member, and the panel member.

The window member generally includes a window film or a window glass. A hard coat may also be provided on the window film or window glass. The window glass may be, for example, a thin glass substrate. High flexibility, high transparency, and high hardness are required for an optical laminate applied to a bendable display device. The material of the window film is not particularly limited as long as it satisfies these physical properties.

＜Window Film＞ As a window film, a transparent resin film is mentioned, for example. The resin constituting the transparent resin film can be, for example, selected from the group consisting of polyimide-based resins, polyamide-based resins, polyester-based resins, cellulose-based resins, acetate-based resins, styrene-based At least one of oxygen-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.

＜Hard Coating＞ The hard coat layer is formed by applying a hardening coating agent on the surface of a layer (eg, a window film) serving as a base and hardening it.

As the coating agent, for example, an optical film application can be used. Coating agents include, for example, acrylic-based coating agents, melamine-based coating agents, urethane-based coating agents, epoxy-based coating agents, polysiloxane-based coating agents, and inorganic-based coating agents. limited to such.

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, surface lubricants agents, leveling agents, antioxidants, light stabilizers, ultraviolet absorbers, polymerization inhibitors, antifouling materials, etc., but not limited to these.

[1st adhesive layer] The first adhesive layer used in the display device of the present invention can pass through it and layer the window member on an area of the optical film member. The adhesive composition constituting the first adhesive layer used in the display device of the present invention includes acrylic adhesives, rubber-based adhesives, vinyl alkyl ether-based adhesives, polysiloxane-based adhesives, polyester-based adhesives, poly Amide-based adhesives, urethane-based adhesives, fluorine-based adhesives, epoxy-based adhesives, polyether-based adhesives, etc. Moreover, the adhesive which comprises a 1st adhesive layer can be used individually or in combination of 2 or more types. However, from the viewpoints of transparency, workability, durability, adhesion, and resistance to deflection, it is preferable to use an acrylic adhesive alone.

<(Meth)acrylic polymer> When an acrylic adhesive is used as the adhesive composition constituting the first adhesive layer, it is preferable to contain a (meth)acrylic monomer having a linear or branched alkyl group having 1 to 24 carbon atoms as a monomer unit (meth)acrylic polymers. By using the (meth)acrylic-type monomer which has the said linear or branched C1-C24 alkyl group, the adhesive layer excellent in flexibility can be obtained. In addition, the (meth)acrylic polymer in the present invention refers to an acrylic polymer and/or a methacrylic polymer, and the (meth)acrylate refers to an acrylate and/or a methacrylate.

Specific examples of the (meth)acrylic monomer having a linear or branched C1-C24 alkyl group constituting the main skeleton of the (meth)acrylic polymer include methyl (meth)acrylate. ester, ethyl (meth)acrylate, n-butyl (meth)acrylate, tertiary butyl (meth)acrylate, tertiary butyl (meth)acrylate, isobutyl (meth)acrylate, (meth)acrylate base) n-amyl acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethyl (meth)acrylate Hexyl ester, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, (meth)acrylate base) isodecyl acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, etc., among which the glass transition temperature (Tg) is generally low The monomer is still a viscoelastic body in a faster speed region when it is flexed, so from the viewpoint of flexibility, the (methyl) with a linear or branched carbon number of 4-8 alkyl groups is used. ) acrylic monomers are preferred. As for the said (meth)acrylic-type monomer, 1 type or 2 or more types can be used.

The (meth)acrylic monomer system having the linear or branched C1-24 alkyl group described above constitutes the main component of the total monomers of the (meth)acrylic polymer. Here, the so-called main component means that among the total monomers constituting the (meth)acrylic polymer, the (meth)acrylic monomer having a linear or branched alkyl group having 1 to 24 carbon atoms is preferably 80 to 100% by weight, preferably 90 to 100% by weight, more preferably 92 to 99.9% by weight, particularly preferably 94 to 99.9.

When an acrylic adhesive is used as the adhesive composition constituting the first adhesive layer, a (meth)acrylic polymer containing a hydroxyl-containing monomer having a reactive functional group as a monomer unit is preferably contained. By using the aforementioned hydroxyl-containing monomer, an adhesive layer excellent in adhesiveness and flexibility can be obtained. The aforementioned hydroxyl-containing monomer system is a compound containing a hydroxyl group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group and a vinyl group.

Specific examples of the aforementioned hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxy (meth)acrylate. Hydroxyalkyl (meth)acrylates such as hexyl ester, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, etc. hydroxymethylcyclohexyl)-methacrylate, etc. From the viewpoint of durability or adhesion, among the aforementioned hydroxyl group-containing monomers, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are also suitable. Moreover, the said hydroxyl-containing monomer can use 1 type or 2 or more types.

Moreover, the monomeric unit which comprises the said (meth)acrylic-type polymer may contain monomers, such as a carboxyl group-containing monomer which has a reactive functional group, an amine group-containing monomer, and an amide group-containing monomer. It is preferable to use these monomers from the viewpoint of the adhesiveness in a humid-heat environment.

When an acrylic adhesive is used as the adhesive composition constituting the first adhesive layer, a (meth)acrylic polymer containing a carboxyl group-containing monomer having a reactive functional group as a monomer unit may be contained. By using the aforementioned carboxyl group-containing monomer, an adhesive layer excellent in adhesion in a humid-heat environment can be obtained. The aforementioned carboxyl group-containing monomer system is a compound containing a carboxyl group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group and a vinyl group.

Specific examples of the carboxyl group-containing monomer include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itonic acid, maleic acid, fumaric acid, crotonic acid, and the like.

When an acrylic adhesive is used as the adhesive composition constituting the first adhesive layer, a (meth)acrylic polymer containing an amine group-containing monomer having a reactive functional group as a monomer unit may be contained. By using the aforementioned amine group-containing monomer, an adhesive layer with excellent adhesion in a humid-heat environment can be obtained. The aforementioned amine group-containing monomer system is a compound containing an amine group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group and a vinyl group.

Specific examples of the aforementioned amine group-containing monomer include N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, and the like.

When an acrylic adhesive is used as the adhesive composition constituting the first adhesive layer, a (meth)acrylic polymer containing an amide group-containing monomer having a reactive functional group as a monomer unit may be contained. By using the aforementioned amide group-containing monomer, an adhesive layer excellent in adhesiveness can be obtained. The aforementioned amide group-containing monomer system is a compound containing an amide group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group and a vinyl group.

Specific examples of the aforementioned amide group-containing monomer include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl acrylamide, N-methyl (meth) acrylamide, N-butyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-methylol ( Meth) acrylamide, N-methylol-N-propane (meth) acrylamide, aminomethyl (meth) acrylamide, aminoethyl (meth) acrylamide, mercaptomethyl ( Acrylamide monomers such as meth)acrylamide and mercaptoethyl (meth)acrylamide; N-(meth)acryloyl morpholin, N-(meth)acrylamide N-(meth)acryloyl pyrrolidine and other N-acryloyl heterocyclic monomers; N-vinyl pyrrolidone, N-vinyl-ε-caprolactamide, etc. containing N-vinyl lactamide Monomers, etc.

As a monomer unit constituting the aforementioned (meth)acrylic polymer, the blending ratio (total amount) of the aforementioned reactive functional group in the total monomer constituting the aforementioned (meth)acrylic polymer is preferably 20 % by weight or less, preferably 10% by weight or less, more preferably 0.01 to 8% by weight, particularly preferably 0.01 to 5% by weight, and most preferably 0.05 to 3% by weight. When it exceeds 20 weight%, since a crosslinking point will increase and an adhesive agent (layer) loses flexibility, there exists a tendency for stress relaxation property to become poor.

In addition to the above-mentioned monomer having a reactive functional group, other comonomers may be introduced into the monomer units constituting the (meth)acrylic polymer within a range not impairing the effects of the present invention. The blending ratio is not particularly limited, but in the total monomers constituting the (meth)acrylic polymer, it is preferably 30% by weight or less, not more preferably. If it exceeds 30 weight%, especially when the thing other than a (meth)acrylic-type monomer is used, the reaction point with a film will become few and there exists a tendency for adhesive force to fall.

In this invention, when using the said (meth)acrylic-type polymer, the range of the weight average molecular weight (Mw) of 1,000,000 - 2,500,000 is generally used. If considering durability, especially considering heat resistance or flexibility, it should be 1.2 million to 2.2 million, and preferably 1.4 million to 2 million. If the weight-average molecular weight is less than 1 million, when polymer chains are cross-linked to each other to ensure durability, the number of cross-linking points increases compared to those with a weight-average molecular weight of 1 million or more, and the adhesive (layer) is lost. Due to its flexibility, the dimensional change between the outer side (convex side) and the inner side (concave side) of the bending that occurs between the films during bending cannot be alleviated, and each film is prone to breakage. In addition, if the weight average molecular weight is more than 2.5 million, a large amount of diluent solvent is required to adjust the viscosity required for coating, which increases the cost, which is unfavorable, and the polymer chain of the obtained (meth)acrylic polymer is not good. The entanglement with each other becomes complicated, and the flexibility deteriorates, so that the film is prone to breakage when flexed. In addition, the weight average molecular weight (Mw) means the value calculated by polystyrene conversion measured by GPC (gel permeation chromatography; Gel Permeation Chromatography).

For the production of the (meth)acrylic polymer, known production methods such as solution polymerization, block polymerization, emulsion polymerization, and various radical polymerizations can be appropriately selected. Moreover, any of a random copolymer, a block copolymer, a graft copolymer, etc. may be sufficient as the obtained (meth)acrylic-type polymer.

In the aforementioned solution polymerization, as a polymerization solvent, for example, ethyl acetate, toluene and the like can be used. As a specific example of solution polymerization, a polymerization initiator can be added under a stream of inert gas such as nitrogen, and it is generally carried out under the reaction conditions of about 50-70° C. and about 5-30 hours.

The polymerization initiator, chain transfer agent, emulsifier, etc. used in the radical polymerization are not particularly limited and can be appropriately selected and used. Moreover, the weight average molecular weight of a (meth)acrylic-type polymer can be controlled by the usage-amount of a polymerization initiator, a chain transfer agent, and reaction conditions, and the usage-amount can be adjusted suitably according to the kind of them.

As said polymerization initiator, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[ 2-(5-Methyl-2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis(2-methylpropionamidine)disulfate, 2,2'-azobis(2-methylpropionamidine)disulfate Nitrobis(N,N'-dimethyleneisobutylamidine), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate (trade name: VA-057, azo initiators such as Wako Pure Chemical Industries, Ltd., potassium persulfate, ammonium persulfate and other persulfates, bis(2-ethylhexyl) peroxydicarbonate, bis(2-ethylhexyl) peroxydicarbonate, etc. 4-tertiary butyl cyclohexyl) peroxydicarbonate, di-tertiary butyl peroxydicarbonate, tertiary butyl peroxyneodecanoate, tertiary hexyl peroxytrimethyl acetate, peroxide Tertiary butyl trimethyl acetate, dilauryl peroxide, di-n-octyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, bis(4-methylbenzyl) peroxide, dibenzyl peroxide, tertiary butyl perisobutyrate, 1,1-bis(tertiary hexyl peroxy) cyclohexane, A combination of peroxide-based initiators such as tertiary butyl hydroperoxide and hydrogen peroxide, a combination of persulfate and sodium bisulfite, a combination of peroxide and sodium ascorbate, and a combination of peroxides and reducing agents Redox-based initiators and the like, but are not limited to these.

The aforementioned polymerization initiators may be used in combination of one or more kinds, but the total content is, for example, about 0.005 to 1 part by weight relative to 100 parts by weight of the total monomers constituting the aforementioned (meth)acrylic polymer, preferably It is about 0.02-0.5 weight part.

In addition, when a chain transfer agent, an emulsifier used in the emulsion polymerization, or a reactive emulsifier is used, a conventionally known one can be appropriately used. In addition, these addition amounts can be suitably determined in the range which does not impair the effect of this invention.

＜Crosslinking agent＞ The adhesive composition constituting the first adhesive layer may contain a crosslinking agent. As the crosslinking agent, an organic crosslinking agent or a polyfunctional metal chelate compound can be used. The organic-based crosslinking agent includes an isocyanate-based crosslinking agent, a peroxide-based crosslinking agent, an epoxy-based crosslinking agent, an imine-based crosslinking agent, and the like. Polyfunctional metal chelates are covalently or coordinately bonded polyvalent metals and organic compounds. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. Examples of atoms that can be covalently or coordinately bonded in the organic compound include oxygen atoms and the like, and examples of the organic compound include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, ketone compounds, and the like. Among them, an isocyanate-based crosslinking agent (especially a trifunctional isocyanate-based crosslinking agent) is preferable from the viewpoint of durability, and a peroxide-based crosslinking agent and an isocyanate-based crosslinking agent (especially a difunctional one) are preferred. An isocyanate-based crosslinking agent) is preferable from the viewpoint of flexibility. Both peroxide-based cross-linking agents and difunctional isocyanate-based cross-linking agents can form soft two-dimensional cross-links, while tri-functional isocyanate-based cross-linking agents can form relatively firm three-dimensional cross-links. Two-dimensional crosslinks, which are softer crosslinks, are favored upon flexing. However, if there is only two-dimensional cross-linking, it will lack durability and easily peel off. Therefore, a hybrid cross-linking of two-dimensional cross-linking and three-dimensional cross-linking is preferred. Therefore, a trifunctional isocyanate-based cross-linking agent and peroxide are used together. A cross-linking agent or a difunctional isocyanate-based cross-linking agent is the preferred form.

The usage amount of the aforementioned crosslinking agent is, for example, preferably 0.01 to 10 parts by weight, preferably 0.03 to 2 parts by weight, relative to 100 parts by weight of the (meth)acrylic polymer. It is a preferable aspect that it is excellent in flexural resistance as it exists in the said range. ＜Other additives＞ In addition, the adhesive composition constituting the first adhesive layer may also contain other known additives, such as various silane coupling agents, polyether compounds of polyalkylene glycols such as polypropylene glycol, colorants, Pigments and other powders, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, antiaging agents, light stabilizers, UV absorbers, polymerization inhibitors, anti-aging agents Electrostatic agents (alkali metal salts of ionic compounds or ionic liquids, etc.), inorganic or organic fillers, metal powders, granules, foils, etc. In addition, a redox system in which a reducing agent is added may be employed within a controllable range.

[Other adhesive layers] The second adhesive layer used in the display device of the present invention is a layer through which the laminated structure can be bulk-layered on the other side of the optical film member.

The third adhesive layer used in the display device of the present invention is a layer that can touch the sensor member through the area layer of the film sealing layer opposite to the panel member.

In addition, the second adhesive layer, the third adhesive layer, and further other adhesive layers may have the same composition (same adhesive composition) and the same properties, or may have different properties, without particular limitation.

<Forming an adhesive layer> The multiple adhesive layers of the present invention are preferably formed from the aforementioned adhesive composition. The method of forming an adhesive layer includes, for example, a method of forming an adhesive layer by drying and removing a polymerization solvent and the like after applying the above-mentioned adhesive composition to a release-treated separator or the like. Moreover, after apply|coating the said adhesive composition to a polarizing film etc., it can also manufacture by the method etc. of drying and removing a polymerization solvent etc., and forming an adhesive layer etc. in a polarizing film. In addition, at the time of coating the adhesive composition, one or more solvents other than the polymerization solvent may be appropriately added separately.

Polysiloxane release liners should be used for the separation parts that have been peeled off. When the adhesive composition of the present invention is coated on the backing material and dried to form an adhesive layer, the method of drying the adhesive may be an appropriate method depending on the purpose. It is desirable to employ a method of drying the above-mentioned coating film by heating. For example, the heating and drying temperature is preferably 40 to 200°C, preferably 50 to 180°C, and particularly preferably 70 to 170°C when preparing an acrylic adhesive using a (meth)acrylic polymer. By setting the heating temperature within the above range, an adhesive having excellent adhesive properties can be obtained.

A suitable drying time can be adopted. For example, the above drying time is preferably 5 seconds to 20 minutes, preferably 5 seconds to 10 minutes, and more preferably 10 seconds to 5 minutes when an acrylic adhesive containing a (meth)acrylic polymer is to be prepared. .

Various methods can be adopted for the coating method of the aforementioned adhesive composition. Specifically, for example, roll coating, touch roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, knife coating, and air knife coating may be mentioned. Methods such as coating, curtain coating, lip coating, and extrusion coating using a die coater or the like are used.

The thickness of the adhesive layer used in the display device of the present invention is preferably 1-200 μm, preferably 5-150 μm, and more preferably 10-100 μm. The adhesive layer may be a single layer or a laminated structure. Within the aforementioned range, bending is not hindered, and it is also preferable from the viewpoint of adhesion (holding resistance). Furthermore, when there are plural layers of adhesive layers, all the adhesive layers are preferably within the aforementioned range. The upper limit of the glass transition temperature (Tg) of the adhesive layer used in the laminate for a flexible image display device of the present invention is preferably 0°C or lower, preferably -20°C or lower, and more preferably -25°C or lower. As long as the Tg of the adhesive layer is within the above range, the adhesive layer is not easily hardened even in the region of high speed when flexed, and the stress relaxation is excellent, so that the flexibility of flexing or foldable can be realized. video display device.

[Panel widget] The panel member may include a panel base such as an image display panel and a substrate holding the image display panel. A sealing member (film sealing layer etc.) may be arrange|positioned at the viewing side of an image display panel. The substrate should just be one that can hold the image display panel and has appropriate strength and flexibility. A resin sheet etc. can be used for such a board|substrate. The material of the resin sheet is not particularly limited, and can be appropriately selected according to the type of the panel.

The image display panel can use a well-known thing. The image display panel can be, for example, an electroluminescence (EL: Electro Luminescence) panel. The image display panel is not limited to an organic EL panel, but may also be a liquid crystal panel, an electrophoretic display panel (electronic paper), or the like. For example, a flexible liquid crystal panel can be formed by using a flexible substrate such as a resin substrate as a transparent substrate sandwiching a liquid crystal layer.

<Film sealing layer> Thin Film Encapsulation (TFEE: Thin Film Encapsulation) has the function of preventing the aforementioned image display panel from being exposed to moisture and/or air. The thin-film sealing layer is formed in the form of an inorganic and organic multilayer film formed by alternately laminating passivation films and resin films on the light-emitting layer. In addition, the constituent material of the thin film sealing layer may include materials with low water permeability, such as inorganic materials and resins such as silicon nitride, silicon oxynitride, carbon oxide, carbon nitride, and aluminum oxide.

[touch sensor member] The touch sensor can be used, for example, in the field of image display devices. The touch sensor can be, for example, a resistive film type, a capacitive type, an optical type or an ultrasonic type, but is not limited to these.

Capacitive touch sensors generally have a transparent conductive layer. Such a touch sensor may be, for example, a laminate of a transparent conductive layer and a transparent substrate. As a transparent base material, a transparent film is mentioned, for example.

<Transparent conductive layer> The transparent conductive layer is not particularly limited, and conductive metal oxides, metal nanowires, and the like can be used. The metal oxide includes, for example, indium oxide (ITO: Indium Tin Oxide) containing tin oxide, and tin oxide containing antimony. The transparent conductive layer can also be a conductive pattern composed of metal oxide or metal. The shape of the conductive pattern includes stripes, squares, lattices, and the like, but is not limited to these.

＜Transparent film＞ As the transparent film, for example, a transparent resin film can be used. Examples of resins constituting the transparent film include polyester-based resins (including polyarylate-based resins), acetate-based resins, polyether-based resins, polycarbonate-based resins, polyamide-based resins, and polyimide-based resins. Resins, polyolefin-based resins, acrylic 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 resin, cellulose resin, epoxy resin, urethane resin, etc. The transparent film may contain one of these resins, or two or more of them. Among these resins, polyester-based resins, polyimide-based resins and polyether-based resins are preferred. However, the resin constituting the transparent film is not limited to these resins.

[protection member] The protective member is laminated on the face side opposite to the second adhesive layer of the panel member through the fourth adhesive layer. The protective member is attached to the back of the flexible image display panel and functions as a reinforcing plate for reinforcing mechanical strength, and is used to protect the flexible image display panel from damage or impact on the resin substrate, and is formed into a film shape.

[Laminated structure] The laminated structure of the present invention has a panel member. In addition, the laminated structure has a layer which is more easily broken than the window member and the optical film member when it is bent and deformed on the surface on the side of the second adhesive layer described later in the display device.

[display device] The display device of the present invention has: an optical film member, a first adhesive layer, a window member laminated on one side of the optical film member through the first adhesive layer, a second adhesive layer, and a second adhesive layer laminated on the other side of the optical film member through the second adhesive layer. A laminated structure, and the display device of the present invention is configured to be bendable.

FIG. 2 is a cross-sectional view showing an embodiment of the display device of the present invention. The display device 100 includes an optical film member 110 , a first adhesive layer 120 , a window member 130 laminated on one side of the optical film member 110 through the first adhesive layer 120 , a second adhesive layer 140 and laminated through the second adhesive layer 140 on The laminated structure 101 on the other surface of the optical film member 110 . The laminated structure 101 includes the panel member 150 . The display device 100 is configured to be bendable.

Although optional, the window member 130 may have a hard coat layer 131 on the surface opposite to the first adhesive layer 120 .

Although optional, the optical film member 110 may be a circularly polarizing functional film laminate 115 in which the retardation film 113 is laminated on the polarizing film 111 . The circularly polarizing functional film laminate 115 is used for, for example, generating circularly polarized light or compensating for viewing angles, etc., in order to prevent light incident from the viewing side of the polarizing film 111 from being internally reflected and then being emitted to the viewing side.

Although optional, the polarizing film 111 may be a laminate in which the polarizer 117 and the polarizer protective film 119 on at least one side of the polarizer 117 are laminated.

Although optional, the polarizer protective film 111 may include an acrylic resin.

The laminated structure 101 has a layer which is more easily broken than the window member 130 and the optical film member 110 when being bent and deformed on the surface on the side of the second adhesive layer 140 .

Although it is optional, the laminated structure 101 may be one of the following: further includes a third adhesive layer 160, a film sealing layer 151 is formed on the surface of the panel member 150 on the side of the second adhesive layer 140, and the film sealing layer The surface of the touch sensor member 151 opposite to the panel member 150 is laminated with a touch sensor member 170 through the third adhesive layer 160, and a transparent conductive member 170 is formed on the surface of the touch sensor member 170 opposite to the panel member 150. layer 171, and the transparent conductive layer 171 is laminated on the second adhesive layer 140 in the form of a layer that is more easily broken than the window member 130 and the optical film member 110.

Although it is optional, a fourth adhesive layer 180 may be provided on the opposite side of the panel member 150 to the aforementioned third adhesive layer 160 , and a protective member 190 may be laminated through the fourth adhesive layer 180 .

In the display device 100, the following equations (1), (2), and (3) are established between the following strain differences A, A', B, and B', so that the aforementioned easy-to-break strain after bending deformation is established. The elongation of the layer is suppressed to a value smaller than the elongation at break: the display device 100 is bent at an angle of 180° toward the outside as the window member 130 , and the bending is deformed so that it is bent at an angle of 180°. In the state where the distance between the outermost surfaces of the display device 100 facing in parallel is 4 mm, the strain in the direction perpendicular to the bending radius direction is generated on one surface of the optical film member 110 and the first adhesive layer on the surface of the window member 130 The difference of the strain in the direction orthogonal to the bending radius direction generated on the surface of 120 is set as A; the optical film member 110 and The window member 130 is bent at an angle of 180° in the state of each single layer, and the bending is deformed to be the most parallel opposite of the optical film member 110 and the window member 130 in the state of being bent at an angle of 180°. When the distance between the surfaces is 4 mm, the difference between the strain generated on the outer surface of the optical film member 110 in the direction orthogonal to the bending radius direction and the strain generated on the inner surface of the window member 130 in the direction orthogonal to the bending radius direction. The difference is set as A'; the display device 100 is bent at an angle of 180° with the window member 130 facing the outside, and the bending is deformed to be parallel to the opposite side of the display device 100 in the state of being bent at an angle of 180°. When the distance between the outermost surfaces is 4 mm, the strain generated on the other surface of the optical film 110 in the direction perpendicular to the bending radius direction, and the direction of the bending radius generated on the surface of the laminated structure 101 facing the second adhesive layer 140 and the bending radius direction The difference between the strains in the orthogonal directions is set as B; the optical thin film member 110 and the laminated structure 101 are placed between the respective single layers in the same manner as the outer and inner sides after bending and deformation are the same as those after bending and deformation of the aforementioned display device. When bent at an angle of 180° in the state, and deformed so that the distance between the parallel facing outermost surfaces of the optical film member 110 and the laminated structure 101 in the state bent at an angle of 180° becomes 4 mm The difference between the strain generated on the inner surface of the optical film member 110 in the direction orthogonal to the bending radius direction and the strain generated on the outer surface of the laminated structure 101 in the direction orthogonal to the bending radius direction is defined as B'. 0.3＜A/A’＜1.2 ・・・・(1) B/B’＜1.7A/A’-0.15 ・・・・(2) 0＜B/B’＜1.25 ・・・・(3)

A is the strain generated on the outer surface of the optical film member 110 in the direction perpendicular to the bending radius direction when the first adhesive layer 120 is present between the optical film member 110 and the window member 130 to be bent and deformed, A' is the difference between the strain generated on the inner surface of the window member 130 in the direction perpendicular to the bending radius direction, and A' is when the optical film member 110 and the window member 130 are bent and deformed in a single-layered state. The difference A' between the strain generated on the outer surface of the optical film member 110 in the direction orthogonal to the bending radius direction and the strain generated on the inner surface of the window member 130 in the direction orthogonal to the bending radius direction, the first adhesion The harder the layer 120 is, the smaller the value of A/A' is, that is, we believe that A/A' will be an indicator of the hardness of the first adhesive layer 120 in the construction of the display device 100 . Similarly, the harder the second adhesive layer 140 is, the smaller the value of B/B' is, that is, we believe that B/B' will be an indicator of the hardness of the second adhesive layer 140 in the configuration of the display device 100 .

In this regard, in a laminate in which a plurality of layers and/or members are laminated through a plurality of adhesive layers, bending displacement occurs on the surfaces of the layers and/or members facing each other across the adhesive layers. The layers affect each other and affect the elongation rate of each layer and/or member. The inventors have focused on this and found for the first time that by properly selecting the hardness of a plurality of adhesive layers, when bending and deforming the laminated body, the laminated body can be suppressed. The elongation of the flexurally fragile layer and/or member contained in the body, thereby inhibiting fracture of the flexurally fragile layer and/or member. Therefore, using A/A' and B/B', the first adhesive layer 120 is appropriately selected so as to satisfy the equations (1) to (3) that define the conditions for A/A' and B/B' The respective hardnesses of the second adhesive layer 140 and the second adhesive layer 140 can suppress the elongation of the layer that is easy to break during bending deformation to a value smaller than the elongation at break, thereby suppressing the breakage of the layer that is easy to break.

Here, in terms of the factors determining the hardness of the adhesive layer, the shear modulus of elasticity G' of the adhesive layer is the main control factor, and the thickness of the adhesive layer is also a factor. The smaller the thickness of the adhesive layer, the harder the adhesive layer.

Although it is optional, the shear modulus of elasticity G' of the second adhesive layer 140 can be made larger than the shear modulus of elasticity G' of the first adhesive layer 110. In this regard, the present inventors discovered for the first time that in a laminate in which a plurality of layers and/or members are laminated through a plurality of adhesive layers, when a certain adhesive layer is hardened, when the laminate is bent, the adhesive layer is laminated on the adhesive layer. The strain of the layer or member outside the layer will be displaced to the tensile side, and the strain of the layer or member laminated inside the adhesive layer will be displaced to the compression side. Moreover, the shear elastic modulus G' of the adhesive layer is the main control factor for the hardness of the adhesive layer, so by making the above structure, the transparency of the fragile layer generated inside the second adhesive layer 140 can be further reduced. Tensile strain of the conductive layer 171 or the film sealing layer 151 .

Although it is optional, the shear modulus of elasticity G' of the fourth adhesive layer 180 can be smaller than the shear modulus of elasticity G' of the second adhesive layer 140 and smaller than the shear modulus of elasticity G of the third adhesive layer 160 '. When an adhesive layer is softened, the strain of the layer or member laminated on the outside of the adhesive layer will be displaced to the compression side, and the strain of the layer or member laminated on the inside of the adhesive layer will be displaced to the tensile side. Moreover, the shear elastic modulus G' of the adhesive layer is the main control factor for the hardness of the adhesive layer, so by making the above structure, the transparent layer which is formed outside the fourth adhesive layer 180 and is a fragile layer can be further reduced. Tensile strain of the conductive layer 171 or the film sealing layer 151 .

Although it is an optional option, the relationship of 0.8<A/A' can be established between the strain differences A and A'. When an adhesive layer is softened, the strain of the layer or member laminated on the outside of the adhesive layer will be displaced to the compression side, and the strain of the layer or member laminated on the inside of the adhesive layer will be displaced to the tensile side. In addition, the harder the first adhesive layer 120 is, the smaller the value of A/A' is. Therefore, by making the above configuration, the difference between the hard coat layer 131 formed on the layer outside the first adhesive layer 120 can be reduced. tensile strain.

As described above, in a laminate in which a plurality of layers and/or members are laminated through a plurality of adhesive layers, when a certain adhesive layer is hardened, the strain of the layer or member laminated on the outside of the adhesive layer when the laminate is bent will be displaced to the tensile side, and the strain of the layers or components laminated inside the adhesive layer will be displaced to the compression side. Therefore, when it is desired to suppress the rupture of a layer that is vulnerable to deflection inside an adhesive layer, the hardness of the adhesive layer may be changed to a larger value, and when a layer that is vulnerable to deflection outside an adhesive layer is to be restrained from being ruptured , the hardness of the adhesive layer can be changed to the smaller one.

For example, in the design process of the display device, when the easy-to-break layer located inside the first adhesive layer or the second adhesive layer is broken or predicted to be broken in the laminated structure, the first adhesive layer or the second By changing the hardness of at least one of the adhesive layers to a larger one, breakage of the easily breakable layer can be suppressed. At this time, among the factors determining the hardness of the adhesive layer, there are, for example, the shear modulus of elasticity G' of the adhesive layer and the thickness of the adhesive layer. By changing to the smaller one or by changing the elastic modulus of at least one of the first adhesive layer or the second adhesive layer to the higher one, the breakage of the easily breakable layer can be suppressed.

In addition, at this time, the easily fractured layer of the laminated structure is located outside the third adhesive layer and the fourth adhesive layer, so by changing the hardness of at least one of the third adhesive layer or the fourth adhesive layer to the smaller one , For example, changing the thickness of the third adhesive layer to a larger one, and/or changing the shear modulus of elasticity G' of at least one of the third adhesive layer or the fourth adhesive layer to a lower one, can prevent easy breakage rupture of the layer.

The display device shown in FIG. 3 is basically the same as that shown in FIG. 2 , except that the layer that is more easily broken than the window member 130 and the optical film member 110 is the transparent conductive layer 171 in the display device of FIG. 3 . The transparent conductive layer 171 is formed on the surface of the touch sensor member 170 laminated between the second adhesive layer 140 and the panel member 150 on the side opposite to the panel member 150 , and compared to the window member 130 and the panel member 150 , the transparent conductive layer 171 is formed. In the display device of FIG. 4 , the more easily fractured layer of the optical film member 110 is the film sealing layer 151 formed on the surface of the panel member 150 on the side of the second adhesive layer 140 .

[Base material laminate] The substrate laminate 103 of the present invention is used for display devices, and the layer of the substrate laminate 103 that is more easily broken than the window member and the optical film member is a transparent conductive layer, and the transparent conductive layer is formed on the second adhesive layer. The surface of the touch sensor member between the layers and the panel member on the opposite side to the panel member; and the base material laminate 103 has: an optical film member; the window member is transmitted through the first adhesive layer On one side of the optical film member; and the touch sensor member, which is laminated on the other side of the optical film member through the second adhesive layer and includes the transparent conductive layer.

Example Hereinafter, the display device and the base material laminate of the present invention will be further described using the following examples. In addition, the display device and the substrate laminate of the present invention are not limited by these embodiments. [Example 1]

[Polarizer] An amorphous polyethylene terephthalate (hereinafter also referred to as “PET”) (IPA copolymerized PET) film (thickness: 100 μm) having 7 mol % isophthalic acid units was prepared as a thermoplastic resin base material, and the The surface is corona treated (58W/m2/min). On the other hand, 1 wt % of acetyl acetyl group-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: GOHSEFIMER Z200 (average degree of polymerization: 1200, degree of saponification: 98.5 mol%, ethyl acetate) was prepared. Acetylation degree: 5 mol %) PVA (polymerization degree 4200, saponification degree 99.2%), and a PVA-based resin is prepared as a coating solution of a PVA aqueous solution of 5.5 wt% so that the film thickness after drying becomes After coating at 12 μm and drying by hot air for 10 minutes in a gas atmosphere of 60° C., a laminate having a layer of PVA-based resin provided on the base material was produced.

Next, this laminate was first stretched by 1.8 times the free end at 130° C. in air (air-assisted stretching) to produce an extended laminate. Next, by immersing the stretched layered body in a boric acid-insoluble aqueous solution having a liquid temperature of 30° C. for 30 seconds, an insolubilization step was performed on the PVA layer in which the PVA molecules contained in the stretched layered body were oriented. The boric acid-insoluble aqueous solution in this step is such that the content of boric acid is 3 parts by weight relative to 100 parts by weight of water. And by dyeing this extended laminated body, a colored laminated body is produced. The coloring laminate system is to immerse the stretched laminate in a dyeing solution containing iodine and potassium iodide at a liquid temperature of 30°C for any period of time so that the transmittance of the PVA layer constituting the final polarizer is 40-44%. This is obtained by dyeing the PVA layer contained in the stretched laminate with iodine. In this step, the dyeing solution uses water as a solvent, and the concentration of iodine is set in the range of 0.1-0.4 wt %, and the concentration of potassium iodide is set in the range of 0.7-2.8 wt %. The concentration ratio of iodine to potassium iodide is 1 to 7. Next, the step of subjecting the PVA molecules of the iodine-adsorbed PVA layer to a cross-linking treatment was performed by immersing the colored laminate in a boric acid cross-linking aqueous solution at 30° C. for 60 seconds. In the boric acid cross-linking aqueous solution in this step, the content of boric acid is 3 parts by weight relative to 100 parts by weight of water, and the content of potassium iodide is 3 parts by weight relative to 100 parts by weight of water.

Then, the obtained colored laminate was stretched 3.05 times in the same direction as previously stretched in air at a stretching temperature of 70° C. in a boric acid aqueous solution (stretching in boric acid water) to obtain an optical film with a final stretch magnification of 5.50 times. Laminated body. The optical thin film 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 an aqueous solution having a potassium iodide content of 4 parts by weight relative to 100 parts by weight of water. The optical thin-film laminate after cleaning was subjected to a drying step using warm air at 60°C and dried. The thickness of the polarizer contained in the obtained optical film laminate was 5 µm.

[Polarizer protective film] The polarizer protective film is obtained by extruding a methacrylic resin pellet having a glutarimide ring unit into a film shape and then extending. The polarizer protective film has a thickness of 40µm and is an acrylic film with a moisture permeability of 160g/m ² .

[Polarizing film] Next, the polarizer and the polarizer protective film were bonded together using an adhesive shown below to prepare a polarizing film.

，日本化藥公司製 The aforementioned adhesive (active energy ray hardening type adhesive) was prepared by mixing the components according to the mixing table described in Table 1, and stirring at 50° C. for 1 hour to prepare an adhesive (active energy ray hardening type adhesive A) . The numerical value in the table refers to the blending amount (addition amount), which indicates the solid content or the solid content ratio (weight basis), and indicates the weight % when the total amount of the composition is 100 weight %. The ingredients used are as follows. HEAA: Hydroxyethyl acrylamide M-220: ARONIX M-220, tripropylene glycol diacrylate), manufactured by Toagosei Co., Ltd. ACMO: Acrylomorphine AAEM: 2-Acetylacetoxyethylmethyl Acrylates, Nippon Synthetic Chemical Co., Ltd. UP-1190: ARUFON UP-1190, Toagosei Co., Ltd. IRG907: IRGACURE907, 2-methyl-1-(4-methylthiophenyl)-2-mfolinprop-1 - Ketone, DETX-S manufactured by BASF: KAYACURE DETX-S, diethyl 9-oxothio𠮿

, manufactured by Nippon Kayaku Co., Ltd.

[Table 1]

In addition, in the Example and the comparative example using the said adhesive agent, after laminating|stacking the said polarizer protective film and the said polarizer through this adhesive agent, it irradiates an ultraviolet-ray to harden this adhesive agent, and an adhesive agent layer is formed. Ultraviolet irradiation was performed using a gallium-filled metal halide lamp (manufactured by Fusion UV Systems, Inc., trade name "Light HAMMER10", valve: V valve, peak illuminance: 1600 mW/cm ² , cumulative irradiation dose 1000/mJ/cm ² ( Wavelength 380~440nm).

[retardation film] The retardation film (1/4 wavelength retardation plate) of this embodiment is composed of two layers, the retardation layer for 1/4 wavelength plate and the retardation layer for 1/2 wavelength plate, which are oriented and immobilized by the liquid crystal material. The retardation film. Specifically, it is manufactured according to the following procedures.

(liquid crystal material) A polymerizable liquid crystal material (manufactured by BASF: trade name Paliocolor LC242) exhibiting a nematic liquid crystal phase 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 photopolymerization initiator (manufactured by BASF: Irgacure 907, trade name) for the polymerizable liquid crystal material was dissolved in toluene. In addition, in order to improve the coating property, about 0.1 to 0.5% of the MEGAFACE series manufactured by DIC was added according to the thickness of the liquid crystal, and a liquid crystal coating liquid was prepared. The liquid crystal coating liquid was applied on the alignment substrate by a bar coater, heated and dried at 90° C. for 2 minutes, and then cured with ultraviolet rays in a nitrogen atmosphere to be oriented and immobilized. As the base material, for example, a liquid crystal coating layer such as PET can be used to transfer the liquid crystal coating layer. And in order to improve the coating property, the fluorine-based polymer of the MEGAFACE series made by DIC is added to about 0.1% to 0.5% according to the thickness of the liquid crystal layer, and MIBK (methyl isobutyl ketone), cyclohexanone or MIBK and cyclohexane are used. A mixed solvent of hexanone was dissolved in a solid content concentration of 25% to prepare a coating liquid. The coating liquid was applied to a base material with a wire bar, and after a drying step set at 65° C. for 3 minutes, it was hardened with ultraviolet rays in a nitrogen atmosphere to be oriented and fixed. As the base material, for example, a liquid crystal coating layer such as PET can be used to transfer the liquid crystal coating layer.

(manufacturing step) The manufacturing steps of this embodiment will be described with reference to FIG. 4 . The manufacturing step 20 is to provide the substrate 14 with rolls and feed the substrate 14 from a supply reel 21 . The manufacturing step 20 is to apply the coating liquid of the ultraviolet curable resin 10 on the substrate 14 with the die 22 . In this manufacturing step 20, the roll plate 30 is a cylindrical forming mold, and the uneven shape of the orientation film for a quarter-wavelength plate with respect to a quarter-wavelength retardation plate is formed on the peripheral side surface thereof. The manufacturing step 20 is to press the substrate 14 coated with the ultraviolet curable resin on the peripheral side surface of the roll plate 30 by the pressing roller 24, and irradiate the ultraviolet rays with the ultraviolet irradiation device 25 composed of the high pressure mercury lamp, so that the ultraviolet curable resin is irradiated with ultraviolet rays. hardening. Thereby, in the manufacturing process 20, the uneven|corrugated shape formed in the peripheral side surface of the roll plate 30 is transcribe|transferred to the base material 14 so that it may become 75 degrees with respect to the MD direction. After that, the base material 14 and the cured ultraviolet curable resin 10 are integrally peeled off from the roll plate 30 by the peeling roller 26 , and then the liquid crystal material is applied by the die 29 . After that, the liquid crystal material is cured by ultraviolet irradiation with the ultraviolet irradiation device 27, and the configuration of the retardation layer for a quarter-wavelength plate is prepared by these procedures.

Next, in step 20 , the substrate 14 is transported to the die head 32 by the transport roller 31 , and the coating of the ultraviolet curable resin 12 is applied on the retardation layer for 1/4 wavelength plate of the substrate 14 by the die head 32 . Cloth liquid. In this manufacturing step 20, the roll plate 40 is a cylindrical forming mold, and the uneven shape of the orientation film for a half-wavelength plate with respect to a quarter-wavelength retardation plate is formed on the peripheral side surface thereof. In the manufacturing step 20, the substrate 14 coated with the ultraviolet curable resin is pressed against the peripheral side surface of the roll plate 40 by the pressing roller 34, and the ultraviolet curable resin is irradiated with ultraviolet rays by the ultraviolet irradiation device 35 composed of a high-pressure mercury lamp. hardening. Thereby, in the manufacturing process 20, the uneven|corrugated shape formed in the peripheral side surface of the roll plate 40 is transcribe|transferred to the base material 14 so that it may become 15 degrees with respect to the MD direction. After that, the base material 14 and the cured ultraviolet curable resin 12 are integrally peeled off from the roll plate 40 by the peeling roller 36 , and then the liquid crystal material is applied by the die 39 . After that, the liquid crystal material is cured by ultraviolet irradiation with the ultraviolet irradiation device 37, and the structure of the retardation layer for a half-wave plate is produced by these procedures, and the retardation layer for a quarter-wave plate, 1 A retardation film with a thickness of 7 μm composed of two layers of retardation layer for /2 wavelength plate.

[Optical film member (circularly polarizing functional film laminate)] Using the above-mentioned adhesive, the retardation film and the polarizing film obtained through the above procedure were continuously bonded together by a roll-to-roll method, and the axis angle between the slow axis and the absorption axis was 45° to produce a laminated film (circular). polarizing function thin film laminate).

[1st adhesive layer] The adhesive layer constituting the first adhesive layer of this example was produced by the following method. <Preparation of acrylic oligomer> <Oligomer A> As monomer components, 60 parts by weight of dicyclopentyl methacrylate (DCPMA) and 40 parts by weight of methyl methacrylate (MMA), 3.5 parts by weight of α-thioglycerol as a chain transfer agent, and toluene as a polymerization solvent were mixed 100 parts by weight, and stirred at 70° C. for 1 hour under a nitrogen atmosphere. Next, 0.2 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator was charged and reacted at 70°C for 2 hours, then the temperature was raised to 80°C and the reaction was performed 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 (oligomer A) was obtained. The weight average molecular weight of oligomer A was 5100, and the glass transition temperature (Tg) was 130°C. <Oligomer B> A solid acrylic oligomer was obtained in the same manner as the preparation of oligomer A, except that the monomer components were changed to 60 parts by weight of dicyclohexyl methacrylate (CHMA) and 40 parts by weight of butyl methacrylate (BMA) polymer (oligomer B). The weight average molecular weight of the oligomer B was 5000, and the glass transition temperature (Tg) was 44°C.

(polymeric prepolymer) As monomer components for prepolymer formation, 43 parts by weight of lauryl acrylate (LA), 44 parts by weight of 2-ethylhexyl acrylate (2EHA), 6 parts by weight of 4-hydroxybutyl acrylate (4HBA), and N -7 parts by weight of vinyl-2-pyrrolidone (NVP) and 0.015 part by weight of "IRGACURE 184" manufactured by BASF as a photopolymerization initiator, and irradiated with ultraviolet rays to polymerize to obtain a prepolymer composition (polymerization rate; about 10%).

(preparation of adhesive composition) To 100 parts by weight of the above-mentioned prepolymer composition, 0.07 part by weight of 1,6-hexanediol diacrylate (HDDA), 1 part by weight of the above-mentioned oligomer A, and a silane coupling agent ("KBM403" manufactured by Shin-Etsu Chemical Co., Ltd.) were added. ): 0.3 parts by weight was used as a post-addition component, and these were uniformly mixed to prepare an adhesive composition. Hereinafter, this adhesive composition is also referred to as adhesive composition 1 .

(Manufacture of adhesive sheet) A 75µm thick polyethylene terephthalate (PET) film ("DIAFOIL MRF75" manufactured by Mitsubishi Chemical Co.) with a polysiloxane-based mold release layer on the surface was used as a base material (a double release film). ), the above-mentioned photocurable adhesive composition was applied on the substrate so that the thickness was 50 μm to form a coating layer. A 75µm-thick PET film (“Diafoil MRE75” manufactured by Mitsubishi Chemical Co.) with a single-sided polysiloxane release treatment was pasted on the coating layer as a cover sheet (also a light release film). The laminated body was photocured by irradiating ultraviolet rays from the cover sheet side with the irradiation intensity of the irradiation surface directly under the lamp being adjusted to 5 mW/cm ² , to form an adhesive sheet with a thickness of 50 µm. Hereinafter, the adhesive layer of any thickness of the adhesive composition 1 produced by the same method is also referred to as the adhesive layer 1 .

[Second adhesive layer] The adhesive layer constituting the second adhesive layer of this example was produced under the same conditions as the first adhesive layer except that the thickness was 15 µm.

[3rd adhesive layer] The adhesive layer constituting the third adhesive layer of this example was produced by the following method. <Preparation of (meth)acrylic polymer A1> A monomer mixture containing 99 parts by weight of butyl acrylate (BA) and 1 part by weight of 4-hydroxybutyl acrylate (HBA) was fed into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction pipe, and a cooler.

In addition, 0.1 part by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator was fed with ethyl acetate relative to 100 parts by weight of the monomer mixture (solid content), and nitrogen gas was introduced while stirring slowly. After nitrogen substitution, the liquid temperature in the flask was maintained at around 55°C, and a polymerization reaction was performed for 7 hours. Then, ethyl acetate was added to the obtained reaction liquid, and the solution of the (meth)acrylic-type polymer A1 whose solid content concentration was adjusted to 30% and the weight average molecular weight of 1,600,000 was prepared.

<Preparation of acrylic adhesive composition> With respect to 100 parts by weight of the solid content of the obtained (meth)acrylic polymer A1 solution, an isocyanate-based crosslinking agent (trade name: TAKENATE D110N, trimethylolpropane diisocyanate, Mitsui Chemicals Co., Ltd.) was blended. )) 0.1 parts by weight, peroxide-based crosslinking agent benzyl peroxide (trade name: NYPER BMT, manufactured by NOF Corporation) 0.3 parts by weight, silane coupling agent (trade name: KBM403, Shin-Etsu Chemical Co., Ltd.) Industrial Co., Ltd.) 0.08 parts by weight to prepare an acrylic adhesive composition. Hereinafter, this adhesive composition is also referred to as adhesive composition 2 .

＜Production of adhesive sheet＞ The aforementioned acrylic adhesive composition was uniformly coated on a polyethylene terephthalate film with a thickness of 38 μm treated with a polysiloxane-based release agent (PET film, transparent The surface of the substrate) was dried in an air circulation constant temperature oven at 155°C for 2 minutes to form an adhesive layer (the third adhesive layer) with a thickness of 20 μm on the surface of the substrate. On the coating layer, a polyethylene terephthalate film (PET film, transparent substrate, separator) with a thickness of 38µm that has been treated with polysiloxane peeling on one side is attached as a cover sheet (also a light peeling film) . Hereinafter, the adhesive layer of any thickness of the adhesive composition 2 produced by the same method is also referred to as the adhesive layer 2 .

[4th adhesive layer] The adhesive layer constituting the fourth adhesive layer of this example was fabricated under the same conditions as the first adhesive layer except that the thickness was 25 µm.

[window widget] As a window member, a transparent polyimide film (manufactured by KOLON Corporation, product name "C_50", thickness 50 µm (hereinafter also referred to as "window film 1")) as a window film was used as a single-sided device. With acrylic hard coat (thickness 10µm).

The hard coat layer is formed using a coating agent for a hard coat layer. More specifically, firstly, after coating the coating agent on one side of the transparent polyimide film to form a coating layer, the coating layer and the transparent polyimide film were heated at 90° C. for 2 minutes. Next, the coating layer was irradiated with ultraviolet rays at a cumulative light amount of 300 mJ/cm ² using a high-pressure mercury lamp to form a hard coat layer. The window component is created through the above procedure.

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

[touch sensor member] As a transparent resin substrate, a cycloolefin-based resin substrate (“ZEONOR” manufactured by Japan ZEON Co., Ltd., thickness: 25 µm, in-plane birefringence: 0.0001) was prepared.

Next, a diluted solution of a hard coating composition composed of a binder resin is coated on the transparent resin substrate, and a diluted solution of the hard coating composition containing the binder resin and a plurality of particles is coated on the underside of the transparent resin substrate Then, after drying these, ultraviolet rays are irradiated on both surfaces to harden the hard coat composition. Thereby, the first cured resin layer (thickness 1µm) containing no particles was formed on the upper surface of the transparent resin substrate, and the second cured resin layer (thickness 1µm) containing particles was formed under the transparent resin substrate.

In addition, as the particle system, cross-linked acrylic/styrene resin particles (“SSX105” manufactured by Sekisui Plastics Co., Ltd., diameter 3 µm) were used. As the binder resin, urethane-based polyfunctional polyacrylate (manufactured by DIC Corporation, "UNIDIC") was used.

Next, a diluent (“OPSTAR Z7412” manufactured by JSR Corporation, refractive index 1.62) of an optical adjustment composition containing zirconia particles and an ultraviolet curable resin was applied on the top surface of the first cured resin layer, and dried at 80° C. for 3 After a few minutes, UV rays are irradiated. Thereby, an optical adjustment layer (thickness 0.1 µm) was formed on the upper surface of the first cured resin layer.

Next, an ITO layer (thickness: 40 nm), which is an amorphous transparent conductive layer, is formed on the optical adjustment layer by sputtering.

Thereby, the amorphous transparent conductive film provided with the 2nd cured resin layer, the transparent resin base material, the 1st cured resin layer, the optical adjustment layer, and the amorphous transparent conductive layer in this order was produced.

Next, the obtained amorphous transparent conductive thin film was subjected to heat treatment at 130° C. for 90 minutes to crystallize the ITO layer.

[Panel widget] As the panel base, a polyimide resin film ("UPILEX" manufactured by Ube Industries, Ltd., thickness 25µm) made of BPDA (biphenyltetracarboxylic dianhydride) was prepared.

Next, an ITO layer (thickness: 40 nm), which is an amorphous transparent conductive layer, was formed on the polyimide resin film by sputtering.

Next, the obtained amorphous transparent conductive thin film was subjected to heat treatment at 130° C. for 90 minutes to crystallize the ITO layer.

Then, the obtained ITO layer and the transparent conductive film with the ITO layer were used as substitutes for the film sealing layer and the panel member, respectively. Hereinafter, the ITO layer of the substitute for the film sealing layer is also referred to as "the ITO layer in place of the film sealing layer" or "the substitute for ITO layer".

[protection member] The protective member of this example uses a polyimide resin base material ("UPILEX" manufactured by Ube Industries, Ltd., thickness 50 µm) using BPDA (biphenyltetracarboxylic dianhydride) as a raw material.

Various evaluations were performed as follows for each of the obtained members, layers, and films. The properties of each obtained adhesive layer, hard coat layer, polarizer protective film, ITO layer, and substitute ITO layer are shown in Tables 2-1 to 2-3.

[Example 2] Except using the adhesive composition 2 as the adhesive composition constituting the adhesive layer of the second adhesive layer, the respective members, layers, films, and laminates were manufactured and produced under the same conditions as in Example 1, and were carried out in the following manner. various assessments. The properties of each obtained adhesive layer, hard coat layer, polarizer protective film, ITO layer, and substitute ITO layer are shown in Tables 2-1 to 2-3.

[Example 3] Each member, layer, film, and laminate were fabricated and fabricated under the same conditions as in Example 1, except that the following adhesive layer was used as the adhesive layer constituting the second adhesive layer, and various evaluations were performed as follows. The properties of each obtained adhesive layer, hard coat layer, polarizer protective film, ITO layer, and substitute ITO layer are shown in Tables 2-1 to 2-3.

The adhesive layer constituting the second adhesive layer of this example was produced by the following method. <Preparation of (meth)acrylic polymer A3> When the liquid temperature in the flask was maintained at around 55°C for 7 hours, the polymerization reaction was carried out so that the blending ratio (weight ratio) of ethyl acetate and toluene was 95/5, and the preparation was made according to The (meth)acrylic polymer A1 was carried out in the same manner. <Preparation of acrylic adhesive composition> With respect to 100 parts by weight of the solid content of the obtained (meth)acrylic polymer A1 solution, 0.15 parts by weight of trimethylolpropane/toluene diisocyanate (manufactured by Japan Polyurethane Industry Co., Ltd., trade name: CORONATE L) and 0.08 weight part of silane coupling agent (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) was prepared to prepare an acrylic adhesive composition. Hereinafter, this adhesive composition is also referred to as adhesive composition 3 .

＜Production of adhesive sheet＞ The aforementioned acrylic adhesive composition was uniformly coated on a polyethylene terephthalate film with a thickness of 38 μm treated with a polysiloxane-based release agent (PET film, transparent The surface of the substrate) was dried in an air circulation constant temperature oven at 155°C for 2 minutes to form an adhesive layer (second adhesive layer) with a thickness of 15 μm on the surface of the substrate. Then, a polyethylene terephthalate film (PET film, transparent substrate, separator) with a thickness of 38µm, which has been treated with polysiloxane peeling on one side, is attached to the coating layer as a cover sheet (with light peeling). film). Hereinafter, the adhesive layer of any thickness of the adhesive composition 3 produced by the same method is also referred to as the adhesive layer 3 .

[Example 4] Each member, layer, film, laminate was fabricated and fabricated under the same conditions as in Example 1, except that the following adhesive layer was used as the adhesive layer constituting the second adhesive layer, and the display device and the substrate laminate were fabricated as follows body, and perform various assessments in the following manner. The properties of each obtained adhesive layer, hard coat layer, polarizer protective film, ITO layer, and substitute ITO layer are shown in Tables 2-1 to 2-3.

The adhesive layer constituting the second adhesive layer of this example was produced by the following method.

2-ethylhexyl acrylate (2EHA): 63 parts by weight, N-vinyl-2-pyrrolidone (NVP): 15 parts by weight, methyl methacrylate ( MMA): 9 parts by weight, 2-hydroxyethyl acrylate (HEA): 13 parts by weight, 2,2'-azobisisobutyronitrile as a polymerization initiator: 0.2 parts by weight, and ethyl acetate 133 as a polymerization solvent parts by weight, and stirring was performed for 1 hour while introducing nitrogen gas. After removing oxygen in the polymerization system as described above, the temperature was raised to 65° C. and allowed to react for 10 hours, and then ethyl acetate was added to obtain an acrylic polymer solution with a solid content concentration of 30% by weight. Moreover, the weight average molecular weight of the acrylic polymer in the said acrylic polymer solution was 800,000.

Next, an isocyanate-based crosslinking agent (trade name "TAKENATE D110N" was added to the above-mentioned acrylic polymer solution so as to be 1.1 parts by weight in terms of solid content with respect to 100 parts by weight of the acrylic polymer (solid content), Mitsui Chemicals Co., Ltd.), and mixed to prepare an adhesive composition. Hereinafter, this adhesive composition is also referred to as adhesive composition 4 . ＜Production of adhesive sheet＞ The aforementioned adhesive composition 4 was uniformly coated on a polyethylene terephthalate film (PET film, transparent substrate, separator) with a thickness of 38 μm treated with a polysiloxane-based release agent by a spray coater. ), then a coating layer was formed on the PET substrate, and the resultant was put into an oven at 130° C. to dry the coating layer for 3 minutes to form an adhesive sheet with an adhesive layer with a thickness of 15 μm on one side of the PET substrate . On the coating layer, a polyethylene terephthalate film (PET film, transparent substrate, separator) with a thickness of 38µm that has been treated with polysiloxane peeling on one side is attached as a cover sheet (also a light peeling film) . Hereinafter, the adhesive layer of any thickness of the adhesive composition 4 produced by the same method is also referred to as the adhesive layer 4 .

The display device and the substrate laminate of the present embodiment were produced by the following method.

The adhesive layer is transferred from the release film to one of the components sandwiching the adhesive layers, and the components are laminated by sandwiching the adhesive layers, and then pressed with a hand ink roller. From the obtained laminate, a rectangular sample having a width of 30 mm and a length of 100 mm was cut out, and each member of the laminate was adhered to obtain a sample for evaluation.

[Examples 5 to 7, 9, 10, 12, 13, 19, 22, 27, 28, Comparative Example 3] Change the combination of the types of adhesive layers (adhesive layers 1 to 4) constituting the first adhesive layer, the second adhesive layer, the third adhesive layer, and the fourth adhesive layer as shown in Tables 2-1 to 2-3, except Other than that, each member, layer, film, and laminate were fabricated and fabricated under the same conditions as in Example 1, and various evaluations were performed as follows. The properties of each obtained adhesive layer, hard coat layer, polarizer protective film, ITO layer, and substitute ITO layer are shown in Tables 2-1 to 2-3.

[Example 21, 23] Change the combination of the types of adhesive layers (adhesive layers 1 to 4) constituting the first adhesive layer, the second adhesive layer, the third adhesive layer, and the fourth adhesive layer as shown in Tables 2-1 to 2-3, and Except having made the thickness of the 1st adhesive layer 25 micrometers, each member, a layer, a film, and a laminated body were manufactured and produced under the same conditions as Example 1, and various evaluations were performed as follows. The properties of each obtained adhesive layer, hard coat layer, polarizer protective film, ITO layer, and substitute ITO layer are shown in Tables 2-1 to 2-3.

[Examples 8, 11, 14, 15 to 18, 20, 24 to 26, Comparative Examples 1, 2, 4, 5] Change the combination of the types of adhesive layers (adhesive layers 1 to 4) constituting the first adhesive layer, the second adhesive layer, the third adhesive layer, and the fourth adhesive layer as shown in Tables 2-1 to 2-3, except Other than that, each member, layer, film, laminate, display device, and base laminate were fabricated and fabricated under the same conditions as in Example 4, and various evaluations were performed as follows. The properties of each obtained adhesive layer, hard coat layer, polarizer protective film, ITO layer, and substitute ITO layer are shown in Tables 2-1 to 2-3.

[Examples 29 to 31, Comparative Example 5] Change the combination of the types of adhesive layers (adhesive layers 1 to 4) constituting the first adhesive layer, the second adhesive layer, the third adhesive layer, and the fourth adhesive layer as shown in Tables 2-1 to 2-3, and A transparent polyimide film made of DU PONT-TORAY CO., LTD., product name "KAPTON (registered trademark) H type" as the window film for the window member (hereinafter this window film is also referred to as "window film 2") is used. ”), except that each member, layer, film, and laminate were fabricated and fabricated under the same conditions as in Example 1, and various evaluations were performed as follows. The properties of each obtained adhesive layer, hard coat layer, polarizer protective film, ITO layer, and substitute ITO layer are shown in Tables 2-1 to 2-3.

[Evaluate] (measurement thickness) The thickness of the polarizer, polarizer protective film, retardation film, each adhesive layer, transparent film, window film, and protective member was measured using a dial gauge (manufactured by Mitutoyo Corporation). In addition, the thickness of the ITO layer and the substitute ITO layer was measured based on the image image|photographed by a transmission electron microscope (TEM). (Determination of the shear modulus of elasticity G' of the adhesive layer) The separators were peeled off from the adhesive sheets of the Examples and Comparative Examples, and multiple layers of the adhesive sheets were laminated to produce a test sample with a thickness of about 1.5 mm. The test sample was punched out into a disk shape with a diameter of 7.9 mm, sandwiched between parallel plates, and the dynamic viscoelasticity was measured under the following conditions using the "Advanced Rheometric Expansion System (ARES)" manufactured by Rheometric Scientific. As a result, the shear modulus of elasticity G' was read.

(measurement conditions) Deformation Mode: Twist Measurement temperature: -40℃~150℃ Heating rate: 5°C/min Measurement frequency: 1Hz

(Measurement of strain and stress) A retardation film belonging to an optical film member, a laminate of a polarizer and a polarizer protective film, a laminate of a polarizer and a polarizer protective film, a transparent resin substrate with an ITO layer belonging to a touch sensor member, a touch sensor member A transparent resin base material for the control sensor member, an alternative transparent resin base material for a panel member with an alternative ITO layer, an alternative transparent resin base material for the panel member, and a film for protecting the member, and the resulting window film, polarizer, The polarizer protective film, the adhesive layer 1, the adhesive layers 2, 3 and the adhesive layer 4 were cut out to a sample with a width of 10 mm and a length of 100 mm. Each obtained sample was set on a tensile tester (manufactured by Shimadzu Corporation, product name "Autograph AG-IS"), and the strain and stress when stretched at 200 mm/min were measured to obtain a strain-stress curve. The stress is obtained by converting the thickness and width into Pa units. In addition, each adhesive layer is made by laminating a plurality of adhesive layers to produce an adhesive layer with a thickness of 100 µm.

In addition, when it is difficult to make an adhesive layer with a thickness of 100 µm, the strain-stress curve can also be obtained by the following method. 1. Calculate the strain-stress curve for a sample in advance according to the above method, and divide the curve by the tensile modulus of elasticity calculated from the slope of the curve in the strain range of 0.05% to 0.25%, thereby making a normalized Strain-stress curve. 2. The shear elastic modulus G' of the sample to be measured is obtained by measuring by the above method. 3. Measure the components of the sample to be measured, and obtain the Passone's ratio ν. 4. The tensile elastic modulus E' and the shear elastic modulus G' establish the relationship of E'=2G'(1+ν), so E is calculated from the G' and ν measured in the above 2. and 3. '. 5. By multiplying the normalized strain-stress curve prepared in 1. above by the tensile modulus of elasticity E' obtained in 4. above, the strain-stress curve of the sample to be measured can be obtained.

(Simulation of the difference in strain in the direction orthogonal to the bending radius direction) From the obtained strain-stress curves of each member and film, the strain in the direction orthogonal to the bending radius direction of each member, layer, and film when bending and deforming in each Example and each Comparative Example was obtained by simulation, and A was calculated. /A', B/B', 1.7A/A'-0.15. The results are shown in Tables 2-1 to 2-3.

＜Computer simulation software＞ The simulation software system uses Marc made by MSC Software of nonlinear finite element analysis software.

＜Model＞ 1. Layer composition The layer structure of the model is the same as the cross-sectional structure of the display device of the embodiment of FIG. 12 . 2. Model size The length was set to 100 mm, and the thickness was set to the total thickness of each member having the cross-sectional configuration shown in FIG. 12 , and a mesh was created in two dimensions of thickness and length. 3. Bending method As shown in Figure 5, set a curve with a length of 48mm at both ends, and fix the end of the grid 10mm to the curve (rigid model), rotate the curve on the left side by 180°, and make the outermost surface of the grid become the outer side. Bend. The bending diameter was set to be 4 mm between the outermost surfaces of the meshes facing in parallel in a state in which the left curve was rotated by 180°. 4. Enter the physical value of each layer For window films, polarizer protective films, polarizers, transparent resin substrates for touch sensor components, substitute transparent resin substrates for panel components, and protective components), the strain-stress curve data of the tensile test of each component The strain and stress are converted into true strain (ln(strain+1), true stress (stress×(strain+1)), respectively, and the type is entered as signed_eq_mechanical_Strain in the table. The material properties of this part of the mesh Set the Type to Hypoelastic and select the stress-strain curve for this material from the table.

此處，γ=ε+1，f係標稱應力，ε係標稱應變。 For the adhesive layer, first, the strain-stress curve data of the tensile test was fitted by the following Mooney-Rivlin formula, and the coefficients C10, C01, and C11 were calculated. Then, set the type of material property of this part of the mesh to Mooney, and input the calculated coefficients C10, C01, and C11.

Here, γ=ε+1, f is the nominal stress, and ε is the nominal strain.

Regarding the retardation film, the type of material properties of the part of the mesh was set to isotropic elastoplasticity, and the laminated body of the retardation film, the polarizer and the polarizer protective film of the optical film member obtained in the tensile test was obtained. The difference between the strain-test force curve data and the strain-test force curve data of the laminate of the polarizer and the polarizer protective film obtained in the tensile test, and the obtained difference corresponds to the strain- Divide the value of the curve of the test force curve by the cross-sectional area (width × thickness) of the retardation film, and calculate the slope of the curve corresponding to the strain-stress curve of the retardation film in the range of 0.05%~0.25%, This is input as the elastic modulus of the retardation film.

For the ITO layer, the substitute ITO layer, and the hard coat layer, the type of material properties of this part of the mesh is also set to isotropic elastic-plastic, and according to the adhesion of the touch sensor member obtained in the tensile test The difference between the strain-test force curve of the transparent resin substrate of the ITO layer and the strain-test force curve data of the transparent resin substrate of the touch sensor component, the difference between the data of the panel component with the substitute ITO layer obtained in the tensile test The difference between the strain-test force curve of the substitute transparent resin substrate and the strain-test force curve of the substitute transparent resin substrate of the panel member, the strain-test force curve of the window film with the hard coat obtained in the tensile test and the The difference between the strain-test force curves of the window film was calculated and entered separately.

<Simulation result> About each member of each Example and each comparative example, the strain (Elastic Strain in Preferred Sys) in the direction orthogonal to the bending radius direction of a flexure part was calculated (refer FIG. 6). Calculated for Comparative Example 1, Examples 9 to 11, Examples 28, 4, 8 and 11, Examples 8 and 14 to 16, and Examples 17 to 20 in the direction orthogonal to the bending radius direction of the flexure part The distribution of the strain in the lamination direction is shown in Fig. 8 to Fig. 11 .

In addition, for the hard coat layer, polarizer protective film, ITO layer, and ITO layer replacing the film sealing layer of each example and each comparative example, the calculated values and the deflection portion are listed in Tables 2-1 to 2-3. Whether the value of the outermost layer and the elongation of each layer and film in the strain in the direction orthogonal to the bending radius direction is lower than the elongation at break.

In addition, for each example and each comparative example, A/A', 1.7 calculated from the calculated strain in the direction orthogonal to the bending radius direction of the flexure portion are listed in Tables 2-1 to 2-3. A/A'-0.15-B/B', B/B' each value. 11 shows a graph showing the relationship between A/A' and B/B.

(Assessment of occurrence of rupture) For the samples of the display devices of the substitutes obtained in Examples 4, 8, 11, 14 to 18, 20, 24 to 26, and Comparative Examples 1, 2, and 4, the presence or absence of the hard coat layer and polarizer was confirmed during bending. The protective film, the ITO layer, and the ITO layer of the replacement film sealing layer were broken.

Specifically, as shown in FIG. 12 , the display device is bent 180 degrees, the glass plate is used to press the outside of the bent display device, and a 4mm plate is inserted between the glass plates, so that the display devices are most parallel to each other. The flexed state was maintained so that the distance between the surfaces was 4 mm, and the rupture of each layer and film was evaluated. The bending diameter is the same as that of the simulated model, and the distance between the parallel facing outermost surfaces of the display device in a state where the display device is bent at an angle of 180° is set to be 4 mm.

For the ITO layer and the ITO layer replacing the thin-film sealing layer, the occurrence of cracking was evaluated by whether the resistance value of the ITO layer increased after flexing. The electrical resistance value was attached to the surface of the ITO layer with a conductive tape (stub-shaped terminal), and was arranged so that the electrical resistance could be measured from the outside of the display device, and the electrical resistance value was measured with a measuring device. For the ITO layer, a sheet resistance of 50Ω/□ is used, and the resistance value between the short tab-shaped terminals before bending is about 165Ω, and the resistance value in the bending state is more than 1.1 times the resistance value before bending. were assessed as having ruptured.

For the hard coat layer and polarizer protective film, the occurrence of cracking was evaluated by microscope observation or cross-sectional SEM observation after deflection.

The rupture evaluation results of each example and each comparative example are listed in Tables 2-1 to 2-3.

(Calculate elongation at break) Regarding the elongation at break of the polarizer protective film, the elongation at break was calculated as follows. First, the same flexural test as the flexural test used for evaluating the occurrence of cracking was performed after changing the bending diameter, and the bending diameter at which the cracking occurred was confirmed. Then, let the bending diameter at which the rupture occurs be the bending diameter, and use the single layer of the polarizer protective film as a model, the same simulation as the above simulation is performed, and the strain in the direction perpendicular to the bending radius of the flexure portion is calculated, and it is taken as Elongation at break.

In addition, regarding the elongation at break of the hard coat layer, the ITO layer, and the substitute ITO layer, the fracture elongation of the window film with the hard coat layer, the transparent resin substrate, and the substitute transparent resin substrate laminated with the polarizer protection is calculated. The calculation method of the elongation at break of the film was calculated by the same calculation method, and it was taken as the respective elongation at break.

The calculated elongation at break of the hard coat layer, polarizer protective film, ITO layer, and substitute ITO layer of each example and each comparative example is listed in Tables 2-1 to 2-3.

[table 2-1]

[Table 2-2]

[Table 2-3]

[table 3]

[Table 4]

[table 5]

[Table 6]

(Evaluate) From Tables 2-1 to 2-3 and Figure 11, the following can be seen. That is, if 0.3<A/A'<1.2・・・(1), B/B'<1.7A/A'-0.15・・・(2), 0<B/B'<1.25・・・In the display devices of Comparative Examples 1 to 5 of (3), the elongation of the ITO layer at the time of bending deformation was calculated by simulation to be larger than 1.50% of the elongation at break of the ITO layer. That is, it was shown that the ITO layer was broken. In the display devices of Comparative Examples 1, 2, and 4 actually produced, cracks also occurred in the ITO layer. On the other hand, in the display devices of Examples 1 to 31 satisfying the above equations (1) to (3), the elongation of the ITO layer at the time of bending deformation calculated by simulation is less than 1.50% of the elongation at break of the ITO layer . That is, it was shown that the ITO layer did not break. In the actual display devices of Examples 4, 8, 11, 14-18, 20, 24-26, no cracks were observed in the ITO layer. In this way, the simulation results of the Examples and Comparative Examples are very consistent with whether or not cracks occurred in the actually produced Examples and Comparative Examples. Therefore, it can be seen that in the display device of each embodiment, the elongation of the ITO layer during bending deformation can be made smaller than the elongation at break of the ITO layer by satisfying the above equations (1) to (3). That is, the breakage of the ITO layer can be suppressed.

In addition, in the display devices of Examples 1 to 31, the elongation of the polarizer protective film calculated by the simulation is also lower than the elongation at break (4.00%). In the display devices of 14-18, 20, and 24-26, no cracks were observed in the polarizer protective film. In this way, the simulation results of the Examples and Comparative Examples are very consistent with whether or not cracks occurred in the actually produced Examples and Comparative Examples. Therefore, it can be seen that in the display device of each embodiment, the elongation of the polarizer protective film during bending deformation can be made to be higher than the fracture elongation of the polarizer protective film by being constructed in such a way as to satisfy the above formulas (1) to (3). The rate is smaller, that is, the breakage of the polarizer protective film can be suppressed.

In addition, in the display devices of Examples 1 to 14, 19 to 24, 27, and 29 to 31, the elongation of the ITO layer calculated by the simulation was lower than the elongation at break, and the elongation of the substitute ITO layer calculated by the simulation was The ratio was also lower than the elongation at break (0.65%), and in the display devices of Examples 4, 8, 11, 14, 20, and 24 actually produced, no cracking was observed in the substitute ITO layer. In this way, the simulation results of the Examples and Comparative Examples are very consistent with whether or not cracks occurred in the actually produced Examples and Comparative Examples. Therefore, in the display devices of Examples 1-14, 19-24, 27, 29-31, the elongation of the substitute ITO layer during bending deformation can also be made smaller than that of the substitute ITO layer, that is, The fracture of the substitute ITO layer is suppressed.

In addition, in the display devices of Examples 1 to 17, 21, 23, 25, 26, 28 to 31, the elongation of the ITO layer calculated by the simulation was lower than the elongation at break, and the hard coat layer calculated by the simulation The elongation was also lower than the elongation at break (4.00%), and in the display devices of Examples 4, 8, 11, 14-17, 25, and 26, no cracking was observed in the hard coat layer. In this way, the simulation results of the Examples and Comparative Examples are very consistent with whether or not cracks occurred in the actually produced Examples and Comparative Examples. Therefore, it can be seen that the display devices of Examples 1 to 17, 21, 23, 25, 26, and 28 to 31 are configured so as to satisfy 0.8<A/A'<1.2 and 0<B/B'<0.9 , the elongation of the hard coating during bending deformation can also be made smaller than that of the hard coating, that is, the fracture of the hard coating can be suppressed.

In the display devices of Examples 1 to 14, 21, 23, and 29 to 31, all of the ITO layer, the polarizer protective film, the ITO layer in place of the film sealing layer, and the hard coat layer were calculated by simulation. The elongation during bending deformation is lower than the elongation at break, and in the actual display devices of Examples 4, 8, 11, and 14, no ITO layer, polarizer protective film, and ITO replacing the film sealing layer were observed. All layers and hard coats are cracked. In this way, the simulation results of the Examples and Comparative Examples are very consistent with whether or not cracks occurred in the actually produced Examples and Comparative Examples. Therefore, it can be seen that in the display devices of Examples 1 to 14, 21, 23, and 29 to 31, the bending can be achieved by configuring so as to satisfy 0.8<A/A'<0.975 and 0.3<B/B'<0.9 The total elongation of the ITO layer, the polarizer protective film, the ITO layer that replaces the film sealing layer, and the hard coat layer during deformation is smaller than that of each layer and film, that is, the breakage of each layer and film can be suppressed.

In Table 3, Comparative Example 1 and Examples 9 to 11, Comparative Example 2 and Examples 12 to 14, Comparative Example 5 and Examples 29 to 31 of Tables 2-1 to 2-3 are rearranged for easy comparison. From Tables 2-1 to 2-3, Table 3, and Figure 7, the following can be seen.

The display devices of Examples 1 to 4 are display devices with the same structure except for the second adhesive layer. The shear modulus of elasticity G' of the second adhesive layer is the larger in order, and the elongation of the ITO layer and The elongation of the ITO layer substituted for the thin film sealing layer is the smaller in order.

In addition, the display devices of Examples 5 to 8 have the same structure except for the second adhesive layer, and the third adhesive layer is not the adhesive layer 1 of Examples 1 to 4 but the display device of the adhesive layer 2. The second adhesive layer The shear elastic modulus G' is the larger in the order, and the elongation of the ITO layer and the elongation of the ITO layer replacing the film sealing layer are the smaller in the order.

In addition, the display devices of Comparative Example 1 and Examples 9 to 11 have the same structure except for the second adhesive layer, and the third adhesive layer is not the adhesive layer 2 of Examples 1 to 4 or the adhesive layer of Examples 5 to 8. 3. For the display device of the adhesive layer 4, the shear modulus G' of the second adhesive layer is the larger in the order, and the elongation of the ITO layer and the elongation of the ITO layer that replaces the film sealing layer are in the order for the lesser.

In addition, the display devices of Comparative Example 2 and Examples 12 to 14 have the same structure except for the second adhesive layer, and the third adhesive layer is not the adhesive layer 1 of Examples 1 to 4 and the adhesive layer of Examples 5 to 8. 2. In Comparative Example 1 and Examples 9 to 11, the adhesive layer 1 of the display device is the adhesive layer 2. The shear elastic modulus G' of the second adhesive layer is the larger in the order, and the elongation of the ITO layer And the elongation of the ITO layer that replaces the film sealing layer is the smaller in the order.

In addition, the display devices of Comparative Example 5 and Examples 29 to 31 have the same structure except for the second adhesive layer, and the first adhesive layer, the third adhesive layer and the fourth adhesive layer have the same properties as those of Comparative Example 2 and Example 12. The structure of the display device and the window film of the window member is not the window film 1 of Examples 1 to 14 and Comparative Examples 1 to 2 but the display device of the window film 2, and the shear elastic modulus G' of the second adhesive layer is in the order of whichever is greater, and the elongation of the ITO layer and the elongation of the ITO layer substituted for the thin-film encapsulation layer are the smaller in order.

From the above, it can be seen that by increasing the shear modulus G' of the second adhesive layer, the elongation of the ITO layer during bending deformation and the elongation of the ITO layer that replaces the film sealing layer can be reduced, that is, the ITO can be suppressed. layer and the breakage of the ITO layer in place of the thin film sealing layer.

Table 4 is a rearrangement of Examples 28, 4, 8, and 11 of Tables 2-1 to 2-3 for easier comparison. From Tables 2-1 to 2-3, Table 4, and Figure 8, the following can be seen.

The display devices of Examples 28, 4, 8, and 11 are display devices with the same structure except for the third adhesive layer. The elongation rate is the greater in the order.

As can be seen from the above, by reducing the shear modulus of elasticity G' of the third adhesive layer, the elongation of the ITO layer at the time of bending deformation can be reduced, that is, the breakage of the ITO layer can be suppressed.

Table 5 is a rearrangement of Example 8 and Examples 14 to 16 of Tables 2-1 to 2-3 for easier comparison. From Tables 2-1 to 2-3, Table 5, and Fig. 9, the following can be understood.

The display devices of Examples 8 and 14 to 16 are display devices with the same structure except for the fourth adhesive layer. The shear elastic modulus G' of the fourth adhesive layer is the larger in order, and the extension of the ITO layer The ratio and the elongation of the ITO layer substituted for the film sealing layer are in the order of the greater.

As can be seen from the above, by reducing the shear modulus of elasticity G' of the fourth adhesive layer, the elongation of the ITO layer during bending deformation and the elongation of the ITO layer that replaces the film sealing layer can be reduced, that is, the ITO layer can be suppressed. And the fracture of the ITO layer that replaces the film sealing layer.

Table 6 rearranges Example 8, Examples 21 to 22, and Example 11 and Examples 23 to 24 of Table 1 for ease of understanding. From Tables 2-1 to 2-3, Table 6, and Figure 10, the following matters can be seen.

The display devices of Examples 17 to 20 are display devices with the same structure except for the first adhesive layer. The shear elastic modulus G' of the first adhesive layer is the larger in the order, and the elongation of the hard coat layer whichever is greater in the order of the system.

In addition, the display devices of Examples 8, 21, and 22 are display devices as follows: the structure is the same except for the first adhesive layer, and the third adhesive layer is not the adhesive layer 3 of Examples 17 to 20, but is adhesive layer 4, and the fourth adhesive layer is not the adhesive layer 4 of Examples 17-20 but the adhesive layer 1. The shear elastic modulus G' of the first adhesive layer of Examples 8 and 21 is the same, but the thickness of the first adhesive layer of Example 21 is smaller than that of the first adhesive layer of Example 8. Therefore, compared with Example 8, the hardness of the first adhesive layer of Example 21 is higher. Also, as mentioned above, in terms of the factor determining the hardness of the adhesive layer, the shear modulus of elasticity G' of the adhesive layer is the main control factor. The modulus of elasticity G' is more than 2 times larger, so compared with Example 21, the hardness of the first adhesive layer of Example 22 is greater. Therefore, the hardness of the first adhesive layer is the larger in the order, and the elongation of the hard coat layer is the larger in the order.

In addition, the display devices of Examples 11, 23, and 24 have the same structure except for the first adhesive layer, and the fourth adhesive layer is not the adhesive layer 3 of Examples 17 to 20 but the display device of the adhesive layer 4. The hardness of the adhesive layer is the larger in the order, and the elongation of the hard coat layer is the larger in the order.

As can be seen from the above, by reducing the hardness of the first adhesive layer, the elongation of the hard coat layer at the time of bending deformation can be reduced, that is, the breakage of the hard coat layer can be suppressed.

The arrows in the strain distribution diagrams of FIGS. 7 to 10 indicate that the corresponding layers and films when the hardness of the corresponding adhesive layer increases, the strain is displaced to the tensile direction or the displacement to the compression direction. In addition, the broken line represents the elongation at break of the corresponding layers and films.

As can be seen from FIGS. 7 to 10 , in the display devices of each example and each comparative example in which a plurality of layers and components are laminated through a plurality of adhesive layers, when a certain adhesive layer is hardened, the display device is laminated on the display device during bending. The strain of the layer or component outside the adhesive layer will be displaced to the tensile direction, and the strain of the layer or component laminated inside the adhesive layer will be displaced to the compressive direction.

For example, with respect to Comparative Example 1 and Examples 9 to 11, referring to FIG. 7 , in the ranking, the shear modulus G' of the second adhesive layer is larger, that is, the hardness of the second adhesive layer increases, and the As the hardness of the second adhesive layer increases, the strain of the layer or member outside the second adhesive layer is displaced to the tensile direction, and the strain of the layer or member inside the second adhesive layer is displaced to the compression direction. The same applies to the groups of Examples and/or Comparative Examples in FIGS. 8 to 10 .

In the above, the present invention has been described with reference to the drawings for specific embodiments, but the present invention can be further modified in addition to the configurations described in the drawings. Therefore, the present invention is not limited by the structures described in the drawings, and its scope should be construed as being limited by the scope of the appended claims and their equivalents.

10: UV curable resin 12: UV curable resin 14: Substrate 20: Manufacturing Steps 21: Reel 22: Die head 24: Pressure roller 25: UV irradiation device 26: Peeling Roller 27: UV irradiation device 29: Die head 30: Roll version 31: Conveyor roller 32: Die head 34: Pressure roller 35: UV irradiation device 36: Peeling Roller 37: UV irradiation device 39: Die head 40: Roll version 100: Display device 101: Laminated structure 103: Base material laminate 110: Optical film components 111: polarizing film 113: retardation film 115: Circularly polarizing functional thin film laminate 117: Polarizer 119: Polarizer protective film 120: 1st adhesive layer 130: Window widget 131: Hard Coating 133: Window Film 140: Second Adhesive Layer 150: Panel Components 151: Film sealing layer 153: Panel Base 160: 3rd adhesive layer 170: Touch Sensor Components 171: Transparent conductive layer 173: Transparent Film 180: 4th adhesive layer 190: Protection components 900: organic EL display device 901: Organic EL Display Panel 912-1, 912-2: Transparent conductive layer 915-1, 915-2: Substrate films 916-1, 916-2: Transparent conductive films 917: Dividers 920: Optical Laminate 921: Polarizer (polarizing film) 922-1, 922-2: Protective film 923: retardation film (retardation layer, retardation film) 930: Touch Panel

FIG. 1 is a cross-sectional view showing a conventional organic EL display device. FIG. 2 is a cross-sectional view showing a display device according to an embodiment of the present invention. 3 is a cross-sectional view showing a display device according to another embodiment of the present invention. FIG. 4 is a diagram showing a method of manufacturing a retardation film used in an example. FIG. 5 is a diagram showing a simulation method according to an embodiment of the present invention. FIG. 6 is a graph illustrating the strain orthogonal to the bending radius direction. FIG. 7 is a diagram showing the strain distribution in the lamination direction of Examples and Comparative Examples in which the shear modulus G′ of the second adhesive layer was changed. FIG. 8 is a diagram showing the strain distribution in the lamination direction of the example in which the shear modulus G' of the third adhesive layer was changed. FIG. 9 is a diagram showing the strain distribution in the lamination direction of the example in which the shear modulus G' of the fourth adhesive layer was changed. FIG. 10 is a diagram showing the strain distribution in the lamination direction of the example in which the shear modulus G′ of the first adhesive layer was changed. Fig. 11 is a graph showing the relationship between A/A' and B/B'. FIG. 12 is a diagram showing the evaluation method of rupture.

Claims (9)

A display device is characterized in that it is bendable and has: an optical film member, a first adhesive layer, a window member, a second adhesive layer, a laminate structure including a panel member, a fourth adhesive layer, and a protective member, wherein the window The member is laminated on one side of the optical film member through the first adhesive layer, the laminate structure system including the panel member is laminated on the other side of the optical film member through the second adhesive layer, and the fourth adhesive layer is attached to the panel. The surface of the member opposite to the second adhesive layer, and the protective member passes through the fourth adhesive layer; wherein, The above-mentioned laminated structure has a layer on the surface on the side of the above-mentioned second adhesive layer which is more easily broken than the above-mentioned window member and optical film member when subjected to bending deformation, In the laminated structure system, a film sealing layer is formed on the surface of the panel member on the side of the second adhesive layer, and a touch sensor is formed on the surface of the film sealing layer on the opposite side of the panel member through the third adhesive layer. component, and a transparent conductive layer is formed on the surface of the touch sensor component opposite to the panel component, The transparent conductive layer is laminated on the second adhesive layer in the form of a layer that is more easily broken than the window member and the optical film member when deformed by bending, The shear modulus of elasticity of the fourth adhesive layer is smaller than the shear modulus of elasticity of the second adhesive layer, and is smaller than the shear modulus of elasticity of the third adhesive layer, The elongation at break of the aforementioned easily breakable layer is greater than 1.27%; The following equations (1), (2), and (3) are established between the following strain differences A, A', B, and B', whereby the elongation of the easily fractured layer after bending deformation is determined by Suppress to a value smaller than the elongation at break: The display device is bent at an angle of 180° with the window member facing outward, and in the state of being bent at an angle of 180°, the display device is bent and deformed into the outermost surface parallel to the display device. When the distance between each other is 4 mm, the strain in the direction orthogonal to the bending radius direction generated on the aforesaid surface of the optical film member, and the bending radius direction generated on the surface of the window member facing the first adhesive layer is orthogonal to the bending radius direction. The difference of the strain in the direction is set as A; The above-mentioned optical film member and the window member in the state of each single layer are bent at an angle of 180° so that the outer and inner sides after bending and deformation are the same as those after bending and deformation of the above-mentioned display device, and after bending and deformation In the state of bending at an angle of 180°, the optical film member and the window member are respectively bent and deformed so that the distance between the parallel opposite outermost surfaces of the optical film member and the window member is 4 mm. The difference between the strain generated on the outer surface of the film member in the direction orthogonal to the bending radius direction and the strain generated on the inner surface of the window member in the direction orthogonal to the bending radius direction is set as A'; The display device is bent at an angle of 180° with the window member facing outward, and in the state of being bent at an angle of 180°, the display device is bent and deformed into the outermost surface parallel to the display device. When the distance between each other is 4 mm, the strain generated on the other surface of the optical film member in the direction perpendicular to the bending radius direction, and the surface of the laminated structure facing the second adhesive layer, which is perpendicular to the bending radius direction. The difference of strain in the intersecting direction is set as B; The optical film member and the laminated structure were bent at an angle of 180° in the same manner as after bending and deforming the outer side and inner side in the same manner as after bending and deforming the above-mentioned display device in the state of each single layer, and In the state of bending at an angle of 180°, each of the optical film member and the laminated structure is bent and deformed so that the distance between the parallel opposite outermost surfaces of the optical film member and the laminated structure is 4 mm, The difference between the strain generated on the inner surface of the optical film member in the direction orthogonal to the bending radius direction and the strain generated on the outer surface of the laminate structure in the direction orthogonal to the bending radius direction is defined as B'; 0.3＜A/A’＜1.2 ・・・・(1) B/B’＜1.7A/A’-0.15 ・・・・(2) 0＜B/B’＜1.25 ・・・・(3). The display device of claim 1, wherein the window member has a hard coat layer on the surface opposite to the first adhesive layer. The display device according to claim 1 or 2, wherein the optical film member is a circularly polarizing functional film laminate in which a retardation film is laminated on a polarizing film. The display device according to claim 3, wherein the polarizing film is a laminate comprising a polarizer and a polarizer protective film on at least one side of the polarizer. The display device of claim 4, wherein the polarizer protective film comprises an acrylic resin. The display device of claim 1 or 2, wherein the layer more easily broken than the window member and the optical film member is a film sealing layer formed on the surface of the panel member on the side of the second adhesive layer. The display device of claim 2, wherein the relationship of the following formula (4) is further established between the aforementioned strain differences A and A': 0.8 <A/A’ ・・・・(4). The display device of claim 1 or 2, wherein the shear modulus of elasticity of the second adhesive layer is greater than the shear modulus of elasticity of the first adhesive layer. A substrate laminate for use in the display device according to any one of claims 1 to 8 and having: The aforementioned optical film member; The window member is laminated on one side of the optical film member through the first adhesive layer; and The touch sensor member including the transparent conductive layer is laminated on the other side of the optical film member through the second adhesive layer.

Images