JP7207333B2 - LAMINATED PRODUCT AND MANUFACTURING METHOD THEREOF AND TOUCH PANEL - Google Patents

Description

TECHNICAL FIELD The present invention relates to a laminate, its manufacturing method, and a touch panel.

2. Description of the Related Art Conventionally, as a transparent conductive member, there has been known a conductive glass in which an indium oxide thin film is formed on a glass plate. However, since the base material of the conductive glass is glass, it is inferior in flexibility and difficult to apply depending on the application. Therefore, as a transparent conductive member having excellent flexibility, a laminate using a resin has been proposed (Patent Document 1).

JP 2017-65217 A

The laminate described in Patent Document 1 includes a flexible base material, a conductive layer formed on the flexible base material, and an adhesive layer formed on the conductive layer. However, such a conventional laminate does not have sufficient bending resistance. Specifically, when the conventional laminate is repeatedly bent, whitening or cracking of the conductive layer tends to occur at the bent portion. Therefore, there has been a demand for further improvement in bending resistance.

The present invention was invented in view of the above problems, and aims to provide a laminate having excellent bending resistance, a method for producing the same, and a touch panel provided with the laminate.

The inventor of the present invention has made intensive studies to solve the above problems. As a result, the present inventors found that a first resin layer made of a resin A having a predetermined storage elastic modulus, a conductive layer, a second resin layer made of a resin B having a predetermined storage elastic modulus, In this order, the inventors have found that the laminate can suppress appearance change and cracking of the conductive layer when the bending operation is repeated, and completed the present invention.
That is, the present invention includes the following.

[1] A first resin layer made of resin A, a conductive layer, and a second resin layer made of resin B are provided in this order,
The storage modulus of the resin A at 25° C. is 500 MPa or more and 20000 MPa or less,
The laminate, wherein the storage elastic modulus of the resin B at 25°C is 10 MPa or more and 1000 MPa or less.
[2] the first resin layer has a thickness of 1 μm or more and 100 μm or less;
The laminate according to [1], wherein the second resin layer has a thickness of 1 μm or more and 100 μm or less.
[3] The resin A contains a polymer containing an alicyclic structure,
The laminate according to [1] or [2], wherein the resin B contains a hydrogenated block copolymer into which an alkoxysilyl group may be introduced.
[4] The laminate according to any one of [1] to [3], wherein the resin A has a glass transition temperature of 130° C. or higher.
[5] Any one of [1] to [4], wherein the conductive layer contains at least one conductive material selected from the group consisting of metals, conductive metal oxides, conductive nanowires and conductive polymers. The laminate according to .
[6] A touch panel comprising the laminate according to any one of [1] to [5] such that the first resin layer, the conductive layer and the second resin layer are provided in this order from the viewing side. hand,
The touch panel, wherein the laminated body can be bent with the viewing side surface facing outward.
[7] A method for producing a laminate according to any one of [1] to [5],
preparing a first resin layer;
forming a conductive layer on the first resin layer;
and forming a second resin layer on the conductive layer.

ADVANTAGE OF THE INVENTION According to this invention, the laminated body which has the outstanding bending resistance, its manufacturing method, and the touchscreen provided with the said laminated body; can be provided.

FIG. 1 is a cross-sectional view schematically showing a laminate according to one embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a laminate according to one embodiment of the invention.

Hereinafter, the present invention will be described in detail by showing embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and can be arbitrarily modified without departing from the scope of the claims of the present invention and their equivalents.

[1. Overview of Laminate]
1 and 2 are cross-sectional views each schematically showing a laminate 10 according to one embodiment of the present invention.
As shown in FIG. 1, a laminate 10 according to an embodiment of the present invention includes a first resin layer 110 made of resin A, a conductive layer 120, and a second resin layer 130 made of resin B. are provided in this order in the thickness direction. Further, resin A and resin B each have a storage modulus within a predetermined range at 25°C.

Such a laminate 10 has excellent bending resistance. Here, the bending resistance of the laminate 10 means a property that the conductive layer 120 is less likely to crack and change in appearance such as whitening even if the laminate 10 is repeatedly bent. Therefore, even if the laminate 10 is repeatedly folded, it is possible to suppress the occurrence of whitening and cracking of the conductive layer at the folded portion. In particular, as shown in FIG. 2, the laminate 10 has high resistance to bending with the surface 110D on the first resin layer 110 side facing outward and the surface 130U facing the second resin layer 130 facing inside.

In addition, compared to a laminate having a resin layer on only one side of the conductive layer, the laminate 10 having the first resin layer 110 and the second resin layer 130 as resin layers on both sides of the conductive layer 120 has a difference in thermal contraction between the layers. Small curl. Therefore, the laminate 10 can generally suppress curling due to heat.

The laminate 10 may include arbitrary layers in addition to the first resin layer 110 , the conductive layer 120 and the second resin layer 130 . However, it is preferable that the first resin layer 110 and the conductive layer 120 are in direct contact with each other. Moreover, it is preferable that the conductive layer 120 and the second resin layer 130 are in direct contact with each other. Here, "directly" in which two layers are in contact means that there is no other layer between the two layers. Furthermore, it is particularly preferable that the laminate 10 is a film having a three-layer structure including only the first resin layer 110 , the conductive layer 120 and the second resin layer 130 .

[2. First resin layer]
The first resin layer is a resin layer made of resin A having a storage elastic modulus within a predetermined range at 25°C. Specific storage elastic modulus of the resin A contained in the first resin layer at 25° C. is usually 500 MPa or more, preferably 800 MPa or more, particularly preferably 1100 MPa or more, and usually 20000 MPa or less, preferably 18000 MPa or less, and particularly preferably 16000 MPa or less.

A conductive layer is formed between the first resin layer formed of resin A having a storage modulus within the above range and the second resin layer formed of resin B having a storage modulus within a predetermined range. By doing so, cracking of the conductive layer due to bending can be suppressed. In addition, the resin A is less likely to whiten due to bending. Therefore, the bending resistance of the laminate can be improved. In particular, when the storage elastic modulus of Resin A is equal to or higher than the lower limit of the above range, heat-resistant dimensional stability can be improved. Moreover, internal residual stress can be made small by the storage elastic modulus of resin A being below the upper limit of the said range.

The storage modulus of the resin can be measured using a dynamic viscoelasticity measuring device at a frequency of 1 Hz. As specific measurement conditions, the conditions of Examples described later can be adopted.

As the resin A, a resin containing a polymer and optionally containing optional components can be used. One type of polymer may be used alone, or two or more types may be used in combination at an arbitrary ratio. As the polymer contained in the resin A, a resin containing a polymer containing an alicyclic structure is preferable. Hereinafter, a polymer containing an alicyclic structure may be referred to as an "alicyclic structure-containing polymer" as appropriate.

Since the alicyclic structure-containing polymer has excellent mechanical strength, it can effectively improve the bending resistance of the laminate. In addition, alicyclic structure-containing polymers are usually excellent in transparency, low water absorption, moisture resistance, dimensional stability and lightness.

The alicyclic structure-containing polymer is a polymer containing an alicyclic structure in a repeating unit, and includes, for example, a polymer obtainable by a polymerization reaction using a cyclic olefin as a monomer, or a hydride thereof. mentioned. Moreover, as the alicyclic structure-containing polymer, both a polymer containing an alicyclic structure in the main chain and a polymer containing an alicyclic structure in the side chain can be used. Among them, the alicyclic structure-containing polymer preferably contains an alicyclic structure in its main chain. The alicyclic structure includes, for example, a cycloalkane structure, a cycloalkene structure, and the like, and a cycloalkane structure is preferable from the viewpoint of thermal stability and the like.

The number of carbon atoms contained in one alicyclic structure is preferably 4 or more, more preferably 5 or more, more preferably 6 or more, preferably 30 or less, more preferably 20 or less, Particularly preferably, it is 15 or less. When the number of carbon atoms contained in one alicyclic structure is within the above range, mechanical strength, heat resistance, and moldability are highly balanced.

The proportion of repeating units having an alicyclic structure in the alicyclic structure-containing polymer is preferably 30% by weight or more, more preferably 50% by weight or more, still more preferably 70% by weight or more, and particularly preferably 90% by weight. That's it. Heat resistance can be improved by increasing the ratio of repeating units having an alicyclic structure as described above.
In addition, in the alicyclic structure-containing polymer, the remainder other than the repeating unit having an alicyclic structure is not particularly limited, and can be appropriately selected according to the purpose of use.

As the alicyclic structure-containing polymer, either one having crystallinity or one not having crystallinity may be used, or both may be used in combination. Here, a polymer having crystallinity means a polymer having a melting point Mp. A polymer having a melting point Mp is a polymer whose melting point Mp can be observed with a differential scanning calorimeter (DSC). By using the crystalline alicyclic structure-containing polymer, the mechanical strength of the laminate can be particularly effectively increased, so that the bending resistance can be remarkably improved. Moreover, the production cost of the laminate can be reduced by using the alicyclic structure-containing polymer having no crystallinity.

Examples of the crystalline alicyclic structure-containing polymer include the following polymers (α) to (δ). Among these, the polymer (β) is preferable as the alicyclic structure-containing polymer having crystallinity because a laminate having excellent heat resistance can be easily obtained.
Polymer (α): A ring-opening polymer of a cyclic olefin monomer and having crystallinity.
Polymer (β): A hydride of polymer (α) and having crystallinity.
Polymer (γ): A crystalline addition polymer of cyclic olefin monomers.
Polymer (δ): A hydride or the like of polymer (γ) having crystallinity.

Specifically, the crystalline alicyclic structure-containing polymer includes a ring-opening polymer of dicyclopentadiene having crystallinity, and a hydride of a ring-opening polymer of dicyclopentadiene. It is more preferable to have crystallinity, and particularly preferable is a hydrogenated ring-opening polymer of dicyclopentadiene having crystallinity. Here, the ring-opening polymer of dicyclopentadiene means that the ratio of structural units derived from dicyclopentadiene to all structural units is usually 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more, More preferably, it refers to 100% by weight of polymer.

The crystalline alicyclic structure-containing polymer may not be crystallized before manufacturing the laminate. However, after the laminate is produced, the crystalline alicyclic structure-containing polymer contained in the laminate is usually crystallized, and thus can have a high degree of crystallinity. A specific crystallinity range can be appropriately selected according to desired performance, but is preferably 10% or more, more preferably 15% or more. By setting the crystallinity of the alicyclic structure-containing polymer contained in the laminate to the lower limit value or more of the above range, the laminate can be provided with high heat resistance and chemical resistance. Crystallinity can be measured by X-ray diffractometry.

The melting point Mp of the crystalline alicyclic structure-containing polymer is preferably 200° C. or higher, more preferably 230° C. or higher, and preferably 290° C. or lower. By using such a crystalline alicyclic structure-containing polymer having a melting point Mp, it is possible to obtain a laminate having a further excellent balance between moldability and heat resistance.

The alicyclic structure-containing polymer having crystallinity as described above can be produced, for example, by the method described in International Publication No. 2016/067893.

On the other hand, non-crystalline alicyclic structure-containing polymers include, for example, (1) norbornene-based polymers, (2) monocyclic cyclic olefin polymers, (3) cyclic conjugated diene polymers, and (4) Examples include vinyl alicyclic hydrocarbon polymers and hydrides thereof. Among these, norbornene-based polymers and their hydrides are more preferable from the viewpoint of transparency and moldability.

Examples of norbornene-based polymers include ring-opening polymers of norbornene-based monomers, ring-opening copolymers of norbornene-based monomers and other ring-opening copolymerizable monomers, and hydrides thereof; Examples thereof include copolymers, addition copolymers of norbornene-based monomers and other copolymerizable monomers, and the like. Among these, hydrogenated ring-opening polymers of norbornene-based monomers are particularly preferred from the viewpoint of transparency.
The alicyclic structure-containing polymer is selected, for example, from polymers disclosed in JP-A-2002-321302.

Various products are commercially available as the resin containing the alicyclic structure-containing polymer having no crystallinity, and among them, the one having the desired properties can be appropriately selected and used. Examples of such commercially available products include trade names "ZEONOR" (manufactured by Nippon Zeon Co., Ltd.), "Arton" (manufactured by JSR Corporation), "Appel" (manufactured by Mitsui Chemicals, Inc.), and "TOPAS" (manufactured by Polyplastics Co., Ltd.). (manufactured) product group.

The weight average molecular weight (Mw) of the polymer contained in Resin A is preferably 10,000 or more, more preferably 15,000 or more, particularly preferably 20,000 or more, and more preferably 100,000 or less. is 80,000 or less, particularly preferably 50,000 or less. A polymer having such a weight average molecular weight has an excellent balance of mechanical strength, moldability and heat resistance.

The molecular weight distribution (Mw/Mn) of the polymer contained in Resin A is preferably 1.2 or more, more preferably 1.5 or more, particularly preferably 1.8 or more, preferably 3.5 or less, and more preferably 1.5 or more. It is preferably 3.4 or less, particularly preferably 3.3 or less. When the molecular weight distribution is at least the lower limit of the above range, the productivity of the polymer can be enhanced and the production cost can be suppressed. In addition, since the amount of the low-molecular-weight component is reduced when the content is equal to or less than the upper limit, it is possible to suppress the relaxation during exposure to high temperature and enhance the stability of the laminate.

The weight average molecular weight Mw and number average molecular weight Mn of the polymer can be measured in terms of polyisoprene by gel permeation chromatography (hereinafter abbreviated as "GPC") using cyclohexane as a solvent. Toluene can be used as a solvent if the resin is not soluble in cyclohexane. When the solvent is toluene, the weight average molecular weight Mw and the number average molecular weight Mn can be measured in terms of polystyrene.

The proportion of the polymer in resin A is preferably 80% to 100% by weight, more preferably 90% to 100% by weight, and still more preferably 80% to 100% by weight, from the viewpoint of obtaining a laminate having particularly excellent heat resistance and bending resistance. It is preferably 95% to 100% by weight, particularly preferably 98% to 100% by weight.

Resin A may contain optional components in combination with the polymer described above. Examples of optional components include inorganic fine particles; stabilizers such as antioxidants, heat stabilizers, ultraviolet absorbers and near-infrared absorbers; resin modifiers such as lubricants and plasticizers; coloring agents such as dyes and pigments. and antistatic agents. As these optional components, one type may be used alone, or two or more types may be used in combination at any ratio. However, from the viewpoint of exhibiting the effect of the present invention remarkably, it is preferable that the content of the optional component is small.

The glass transition temperature Tg of Resin A is preferably 130° C. or higher, more preferably 140° C. or higher, and even more preferably 150° C. or higher. Since the resin A has a high glass transition temperature Tg as described above, the heat resistance of the resin A can be enhanced, so that the dimensional change of the first resin layer in a high-temperature environment can be suppressed. Methods for forming the conductive layer include formation methods in a high-temperature environment such as a vapor deposition method and a sputtering method. It is possible to do In particular, resin A having excellent heat resistance is useful when it is desired to form a conductive layer having a fine pattern shape. The upper limit of the glass transition temperature of Resin A is preferably 200° C. or lower, more preferably 190° C. or lower, and particularly preferably 180° C. or lower, from the viewpoint of facilitating availability of Resin A. The glass transition temperature can be measured by the method described in Examples below.

The first resin layer usually has high transparency. Specifically, the total light transmittance of the first resin layer is preferably 70% or higher, more preferably 80% or higher, and even more preferably 90% or higher. Total light transmittance can be measured in the wavelength range of 400 nm to 700 nm using an ultraviolet-visible spectrometer.
The haze of the first resin layer is preferably 5% or less, more preferably 3% or less, particularly preferably 1% or less, and ideally 0%. Haze is measured at 5 points using Nippon Denshoku Industries Co., Ltd.'s "Turbidimeter NDH-300A" in accordance with JIS K7361-1997, and the average value obtained therefrom can be adopted.

The thickness of the first resin layer is preferably 1 µm or more, more preferably 10 µm or more, particularly preferably 13 µm or more, and preferably 100 µm or less, more preferably 80 µm or less, and particularly preferably 60 µm or less. When the thickness of the first resin layer is equal to or greater than the lower limit value of the range, the first resin layer can suppress penetration of moisture into the conductive layer. Therefore, deterioration of the conductive layer due to moisture can be effectively suppressed. On the other hand, when the thickness of the first resin layer is equal to or less than the upper limit of the above range, the stress caused by bending can be reduced, so that the bending resistance of the laminate can be effectively improved.

There is no restriction on the manufacturing method of the first resin layer. Examples of the method for producing the first resin layer include a melt molding method and a solution casting method. Among them, the melt molding method is preferable because it can suppress the residual of volatile components such as solvent in the first resin layer. More specifically, the melt molding method can be classified into an extrusion molding method, a press molding method, an inflation molding method, an injection molding method, a blow molding method, a stretch molding method, and the like. Among these methods, the extrusion molding method, the inflation molding method and the press molding method are preferable in order to obtain a first resin layer having excellent mechanical strength and surface precision, and from the viewpoint of efficiently and easily producing the first resin layer. , the extrusion method is particularly preferred.

[3. conductive layer]
The conductive layer usually contains a material having conductivity (hereinafter sometimes referred to as “conductive material” as appropriate). Such conductive materials include, for example, metals, conductive metal oxides, conductive nanowires, conductive polymers, and the like. Moreover, one type of the conductive material may be used alone, or two or more types may be used in combination at an arbitrary ratio. Above all, from the viewpoint of increasing the bending resistance of the laminate, the conductive layer preferably contains at least one conductive material selected from the group consisting of metals, conductive nanowires, and conductive polymers.

Metals include, for example, gold, platinum, silver and copper. Among them, silver, copper and gold are preferred, and silver is more preferred. One type of these metals may be used alone, or two or more types may be used in combination at an arbitrary ratio. When the conductive layer is formed from these metals, a transparent conductive layer can be obtained by forming the conductive layer in a thin line shape. For example, a transparent conductive layer can be obtained by forming the conductive layer as a metal mesh layer formed in a grid pattern.

A conductive layer containing a metal can be formed, for example, by a forming method including applying a conductive layer-forming composition containing metal particles. At this time, a conductive layer as a metal mesh layer can be obtained by printing the composition for forming a conductive layer in a predetermined lattice pattern. Furthermore, the conductive layer can be formed as a metal mesh layer by, for example, applying a conductive layer-forming composition containing a silver salt, and forming fine metal wires in a predetermined lattice pattern by exposure and development. For details of such a conductive layer and a method for forming the same, reference can be made to Japanese Patent Application Laid-Open No. 2012-18634 and Japanese Patent Application Laid-Open No. 2003-331654.

Examples of conductive metal oxides include ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), IWO (indium tungsten oxide), ITiO (indium titanium oxide), and AZO (aluminum zinc oxide). , GZO (gallium zinc oxide), XZO (zinc-based special oxide), IGZO (indium gallium zinc oxide), and the like. Among these, ITO is particularly preferable from the viewpoint of light transmittance and durability. One type of conductive metal oxide may be used alone, or two or more types may be used in combination at an arbitrary ratio.

A conductive layer containing a conductive metal oxide can be formed by, for example, a vapor deposition method, a sputtering method, an ion plating method, an ion beam assisted vapor deposition method, an arc discharge plasma vapor deposition method, a thermal CVD method, a plasma CVD method, a plating method, and these methods. It can be formed by a formation method including a deposition method such as a combination. Among these, the vapor deposition method and the sputtering method are preferable, and the sputtering method is particularly preferable. Since a conductive layer having a uniform thickness can be formed by the sputtering method, it is possible to suppress the occurrence of locally thin portions in the conductive layer.

A conductive nanowire refers to a conductive material having a needle-like or thread-like shape and a nanometer-sized diameter. Conductive nanowires may be straight or curved. Such conductive nanowires can form a good electrical conduction path even with a small amount of conductive nanowires by forming gaps between the conductive nanowires to form a network, and the electrical resistance can realize a conductive layer with a small In addition, since the conductive wire forms openings in the meshes of the mesh, a conductive layer with high light transmittance can be obtained.

The ratio of the thickness d to the length L of the conductive nanowire (aspect ratio: L/d) is preferably 10 to 100,000, more preferably 50 to 100,000, and particularly preferably 100 to 10,000. When conductive nanowires having a large aspect ratio are used in this way, the conductive nanowires can cross each other satisfactorily, and a small amount of conductive nanowires can exhibit high conductivity. As a result, a laminate having excellent transparency can be obtained. Here, the "thickness of the conductive nanowire" means the diameter when the cross section of the conductive nanowire is circular, the minor axis when the cross section is elliptical, and the short diameter when the cross section is polygonal. means the longest diagonal. The thickness and length of conductive nanowires can be measured by scanning electron microscopy or transmission electron microscopy.

The thickness of the conductive nanowires is preferably less than 500 nm, more preferably less than 200 nm, even more preferably 10 nm to 100 nm, particularly preferably 10 nm to 50 nm. Thereby, the transparency of the conductive layer can be enhanced.

The length of the conductive nanowires is preferably between 2.5 μm and 1000 μm, more preferably between 10 μm and 500 μm, particularly preferably between 20 μm and 100 μm. Thereby, the conductivity of the conductive layer can be enhanced.

Examples of conductive nanowires include metal nanowires made of metal and conductive nanowires containing carbon nanotubes.

A highly conductive metal is preferable as the metal contained in the metal nanowires. Examples of suitable metals include gold, platinum, silver and copper, of which silver, copper and gold are preferred, and silver is more preferred. Alternatively, a material obtained by subjecting the above metal to plating (for example, gold plating) may be used. Furthermore, one of the above materials may be used alone, or two or more of them may be used in combination at any ratio.

Any appropriate method can be adopted as a method for producing metal nanowires. For example, a method of reducing silver nitrate in a solution; a method of applying a voltage or current from the tip of a probe to the surface of the precursor to pull out metal nanowires at the tip of the probe to continuously form the metal nanowires; mentioned. In the method of reducing silver nitrate in solution, silver nanowires can be synthesized by liquid phase reduction of a silver salt such as silver nitrate in the presence of a polyol such as ethylene glycol and polyvinylpyrrolidone. Uniformly sized silver nanowires are described, for example, in Xia, Y.; et al. , Chem. Mater. (2002), 14, 4736-4745; Xia, Y.; et al. , Nano letters (2003) 3(7), 955-960, mass production is possible.

As carbon nanotubes, for example, so-called multi-walled carbon nanotubes, double-walled carbon nanotubes, single-walled carbon nanotubes, etc. having a diameter of about 0.3 nm to 100 nm and a length of about 0.1 μm to 20 μm are used. Among them, single-walled or double-walled carbon nanotubes having a diameter of 10 nm or less and a length of 1 μm to 10 μm are preferable because of their high conductivity. In addition, it is preferable that the aggregate of carbon nanotubes does not contain impurities such as amorphous carbon and catalyst metals. Any appropriate method can be adopted as a method for producing carbon nanotubes. Carbon nanotubes produced by an arc discharge method are preferably used. A carbon nanotube produced by an arc discharge method is preferable because of its excellent crystallinity.

A conductive layer containing conductive nanowires can be formed, for example, by a forming method including coating and drying a conductive nanowire dispersion obtained by dispersing conductive nanowires in a solvent.

Solvents contained in the conductive nanowire dispersion include, for example, water, alcohol solvents, ketone solvents, ether solvents, hydrocarbon solvents, aromatic solvents, and the like. , preferably water. Moreover, a solvent may be used individually by 1 type, and may be used in combination of 2 or more types by arbitrary ratios.

The concentration of the conductive nanowires in the conductive nanowire dispersion is preferably between 0.1 wt% and 1 wt%. Thereby, a conductive layer having excellent conductivity and transparency can be formed.

The conductive nanowire dispersion can include optional ingredients in combination with the conductive nanowires and the solvent. Examples of optional components include a corrosion inhibitor that suppresses corrosion of conductive nanowires, a surfactant that suppresses aggregation of conductive nanowires, a binder polymer for holding conductive nanowires in a conductive layer, and the like. Moreover, arbitrary components may be used individually by 1 type, and may be used in combination of 2 or more types by arbitrary ratios.

Examples of coating methods for the conductive nanowire dispersion include spray coating, bar coating, roll coating, die coating, inkjet coating, screen coating, dip coating, slot die coating, relief printing, and intaglio. A printing method, a gravure printing method, and the like can be mentioned. Any appropriate drying method (eg, natural drying, air drying, heat drying) can be employed as the drying method. For example, in the case of heat drying, the drying temperature can be 100° C. to 200° C., and the drying time can be 1 minute to 10 minutes.

The proportion of conductive nanowires in the conductive layer is preferably between 80% and 100% by weight, more preferably between 85% and 99% by weight, relative to the total weight of the conductive layer. Thereby, a conductive layer having excellent conductivity and light transmittance can be obtained.

Examples of conductive polymers include polythiophene-based polymers, polyacetylene-based polymers, polyparaphenylene-based polymers, polyaniline-based polymers, polyparaphenylene vinylene-based polymers, polypyrrole-based polymers, polyphenylene-based polymers, and polyesters modified with acrylic polymers. A polymer etc. are mentioned. Among them, polythiophene-based polymer, polyacetylene-based polymer, polyparaphenylene-based polymer, polyaniline-based polymer, polyparaphenylenevinylene-based polymer and polypyrrole-based polymer are preferred.

Among these, polythiophene-based polymers are particularly preferred. By using a polythiophene-based polymer, a conductive layer having excellent transparency and chemical stability can be obtained. Specific examples of polythiophene-based polymers include polythiophene; poly(3-C _1-8 alkyl-thiophene) such as poly(3-hexylthiophene); poly(3,4-ethylenedioxythiophene), poly(3,4 -propylenedioxythiophene), poly(3,4-(cyclo)alkylenedioxythiophene) such as poly[3,4-(1,2-cyclohexylene)dioxythiophene]; . Here, "C _1-8 alkyl" refers to an alkyl group having 1 to 8 carbon atoms. Moreover, the said conductive polymer may be used individually by 1 type, and may be used in combination of 2 or more types by arbitrary ratios.

The conductive polymer is preferably polymerized in the presence of an anionic polymer. For example, a polythiophene-based polymer is preferably oxidatively polymerized in the presence of an anionic polymer. Anionic polymers include polymers having carboxyl groups, sulfonic acid groups, or salts thereof. Preferably, an anionic polymer having sulfonic acid groups such as polystyrene sulfonic acid is used.

A conductive layer containing a conductive polymer can be formed, for example, by a forming method including applying a conductive layer-forming composition containing a conductive polymer and drying. Japanese Patent Laid-Open No. 2011-175601 can be referred to for a conductive layer containing a conductive polymer.

Since the conductive layer is made of a conductive material as described above, it has conductivity. The conductivity of the conductive layer can be represented, for example, by a surface resistance value. A specific surface resistance value of the conductive layer can be set according to the use of the laminate. In one embodiment, the surface resistance of the conductive layer is preferably 1000Ω/sq. Below, more preferably 900Ω/sq. Below, particularly preferably 800Ω/sq. It is below. Although the lower limit of the surface resistance of the conductive layer is not particularly limited, it is preferably 1 Ω/sq. above, more preferably 2.5Ω/sq. above, particularly preferably 5Ω/sq. That's it.

The conductive layer may be formed entirely or partially between the first resin layer and the second resin layer. For example, the conductive layer may be patterned into a pattern having a predetermined planar shape. Here, the planar shape refers to the shape when viewed from the thickness direction of the layer. The planar shape of the pattern of the conductive layer can be set according to the use of the laminate. For example, when the laminate is used as a circuit board, the planar shape of the conductive layer may be formed into a pattern corresponding to the wiring shape of the circuit. Further, for example, when the laminate is used as a sensor film for a touch panel, the planar shape of the conductive layer is preferably a pattern that works well as a touch panel (for example, a capacitive touch panel). 2011-511357, JP-A-2010-164938, JP-A-2008-310550, JP-A-2003-511799, and JP-A-2010-541109.

A conductive layer usually has a high transparency. Therefore, visible light can normally pass through this conductive layer. The specific transparency of the conductive layer can be adjusted depending on the application of the laminate. Specifically, the total light transmittance of the conductive layer is preferably 80% or higher, more preferably 90% or higher, and still more preferably 95% or higher.

The thickness of each conductive layer is preferably 0.010 µm or more, more preferably 0.020 µm or more, particularly preferably 0.025 µm or more, and preferably 10 µm or less, more preferably 3 µm or less, and particularly preferably 1 µm or less. is. Thereby, the transparency of the conductive layer can be enhanced.

[4. Second resin layer]
The second resin layer is a resin layer made of resin B having a storage elastic modulus within a predetermined range at 25°C. Specific storage elastic modulus at 25° C. of the resin B contained in the second resin layer is usually 10 MPa or more, preferably 15 MPa or more, particularly preferably 30 MPa or more, and usually 1000 MPa or less, preferably 950 MPa or less, particularly preferably 900 MPa or less.

Lamination by forming a conductive layer between the second resin layer formed of resin B having a storage modulus in the above range and the first resin layer formed of resin A as described above The bending resistance of the body can be improved. In particular, when the storage elastic modulus of Resin B is equal to or higher than the lower limit of the range, the heat resistance can be enhanced. Further, when the storage elastic modulus of the resin B is equal to or less than the upper limit of the range, the bending resistance can be enhanced.

In the combination of the first resin layer and the second resin layer as described above, the storage modulus of the resin B contained in the second resin layer is usually higher than the storage modulus of the resin A contained in the first resin layer. rate becomes smaller. Therefore, the second resin layer is superior in flexibility to the first resin layer, and is therefore superior in resistance to deformation. Therefore, the laminate can exhibit particularly high bending resistance when it is bent in a direction in which the surface on the first resin layer side is on the outside and the surface on the second resin layer side is on the inside.

As the resin B, a resin containing a polymer and optionally containing optional components can be used. One type of polymer may be used alone, or two or more types may be used in combination at an arbitrary ratio. As the polymer contained in the resin B, a hydrogenated block copolymer is preferable. The block copolymer hydride is a hydride obtained by hydrogenating a block copolymer. In the following description, the block copolymer may be referred to as "block copolymer [1]" as appropriate. In addition, in the following description, the hydride of the block copolymer [1] may be appropriately referred to as "hydride [2]".

Block copolymer [1] comprises a polymer block [A] containing an aromatic vinyl compound unit and a chain conjugated diene compound unit (straight chain conjugated diene compound unit, branched chain conjugated diene compound unit, etc.) It is preferable to include a polymer block [B] containing Among them, the block copolymer [1] is composed of two or more polymer blocks [A] per one molecule of the block copolymer [1] and one or more polymers per one molecule of the block copolymer [1]. It is particularly preferred to have block [B].

Polymer block [A] is a polymer block containing an aromatic vinyl compound unit. Here, the aromatic vinyl compound unit means a structural unit having a structure formed by polymerizing an aromatic vinyl compound.

Examples of the aromatic vinyl compound corresponding to the aromatic vinyl compound unit of the polymer block [A] include styrene; α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4 -Styrenes having an alkyl group having 1 to 6 carbon atoms as a substituent, such as dimethylstyrene, 2,4-diisopropylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene; 4-chloro Styrenes having a halogen atom as a substituent, such as styrene, dichlorostyrene, and 4-monofluorostyrene; Styrenes having an alkoxy group having 1 to 6 carbon atoms as a substituent, such as 4-methoxystyrene; 4-phenylstyrene styrenes having an aryl group as a substituent such as; vinylnaphthalenes such as 1-vinylnaphthalene and 2-vinylnaphthalene; One of these may be used alone, or two or more of them may be used in combination at any ratio. Among these, aromatic vinyl compounds containing no polar group, such as styrene and styrenes having an alkyl group having 1 to 6 carbon atoms as a substituent, are preferred because they can reduce hygroscopicity, and they are easy to obtain industrially. Therefore, styrene is particularly preferred.

The content of aromatic vinyl compound units in polymer block [A] is preferably 90% by weight or more, more preferably 95% by weight or more, and particularly preferably 99% by weight or more. By increasing the amount of the aromatic vinyl compound unit in the polymer block [A] as described above, the hardness and heat resistance of the second resin layer can be enhanced.

Polymer block [A] may contain any structural unit in addition to the aromatic vinyl compound unit. The polymer block [A] may contain any structural unit singly or may contain two or more types in combination at any ratio.

Arbitrary structural units that may be included in the polymer block [A] include, for example, chain conjugated diene compound units. Here, the chain conjugated diene compound unit means a structural unit having a structure formed by polymerizing a chain conjugated diene compound. Examples of the chain conjugated diene compound corresponding to the chain conjugated diene compound unit include the same examples as the chain conjugated diene compound corresponding to the chain conjugated diene compound unit of the polymer block [B]. mentioned.

Further, as the arbitrary structural unit that the polymer block [A] may contain, for example, a structural unit having a structure formed by polymerizing an arbitrary unsaturated compound other than an aromatic vinyl compound and a chain conjugated diene compound. mentioned. Examples of arbitrary unsaturated compounds include vinyl compounds such as linear vinyl compounds and cyclic vinyl compounds; unsaturated cyclic acid anhydrides; unsaturated imide compounds; and the like. These compounds may have a substituent such as a nitrile group, an alkoxycarbonyl group, a hydroxycarbonyl group, or a halogen group. Among these, from the viewpoint of hygroscopicity, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-eicosene, chain olefins having 2 to 20 carbon atoms per molecule such as 4-methyl-1-pentene and 4,6-dimethyl-1-heptene; cyclic olefins having 5 to 20 carbon atoms per molecule such as vinylcyclohexane; , vinyl compounds having no polar group are preferred, chain olefins having 2 to 20 carbon atoms per molecule are more preferred, and ethylene and propylene are particularly preferred.

The content of any structural unit in polymer block [A] is preferably 10% by weight or less, more preferably 5% by weight or less, and particularly preferably 1% by weight or less.

The number of polymer blocks [A] in one molecule of block copolymer [1] is preferably 2 or more, preferably 5 or less, more preferably 4 or less, and particularly preferably 3 or less. A plurality of polymer blocks [A] in one molecule may be the same or different.

Polymer block [B] is a polymer block containing a chain conjugated diene compound unit. As described above, the chain conjugated diene compound unit refers to a structural unit having a structure formed by polymerizing a chain conjugated diene compound.

Examples of the linear conjugated diene compound corresponding to the linear conjugated diene compound unit of the polymer block [B] include linear conjugated diene compounds and branched conjugated diene compounds. Specific examples of chain conjugated diene compounds include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene and the like. One of these may be used alone, or two or more of them may be used in combination at any ratio. Among them, a linear conjugated diene compound containing no polar group is preferred, and 1,3-butadiene and isoprene are particularly preferred, since they can reduce hygroscopicity.

The content of chain conjugated diene compound units in polymer block [B] is preferably 90% by weight or more, more preferably 95% by weight or more, and particularly preferably 99% by weight or more. By increasing the amount of chain conjugated diene compound units in the polymer block [B] as described above, the flexibility of the second resin layer can be improved.

The polymer block [B] may contain any structural unit other than the chain conjugated diene compound unit. The polymer block [B] may contain any structural unit alone, or may contain two or more types in combination at any ratio.

The optional structural units that may be included in the polymer block [B] include, for example, aromatic vinyl compound units and any unsaturated compounds other than aromatic vinyl compounds and chain conjugated diene compounds that are polymerized to form A structural unit having a structure can be mentioned. These aromatic vinyl compound units and structural units having a structure formed by polymerizing any unsaturated compound include, for example, those exemplified as those that may be contained in the polymer block [A]. Same example as

The content of any structural unit in polymer block [B] is preferably 10% by weight or less, more preferably 5% by weight or less, and particularly preferably 1% by weight or less. The low content of any structural unit in the polymer block [B] can improve the flexibility of the second resin layer.

The number of polymer blocks [B] in one molecule of block copolymer [1] is usually 1 or more, but may be 2 or more. When the number of polymer blocks [B] in block copolymer [1] is two or more, those polymer blocks [B] may be the same or different.

The block form of the block copolymer [1] may be a linear block or a radial block. Among them, a chain type block is preferable because of its excellent mechanical strength. When the block copolymer [1] has the form of a chain type block, the second resin layer is desired to be sticky because both ends of the molecular chain of the block copolymer [1] are polymer blocks [A]. can be kept to a low value.

A particularly preferred block form of the block copolymer [1] is represented by [A]-[B]-[A], where the polymer block [A] is bound to both ends of the polymer block [B]. triblock copolymer; polymer block [B] is bound to both ends of polymer block [A] as represented by [A]-[B]-[A]-[B]-[A] and a pentablock copolymer in which polymer block [A] is bonded to the other end of both polymer blocks [B]. In particular, [A]-[B]-[A] triblock copolymers are particularly preferred because they are easy to produce and their physical properties can be easily adjusted within desired ranges.

In the block copolymer [1], the weight fraction wA of the polymer block [A] in the whole block copolymer [1] and the weight fraction wA of the polymer block [B] in the whole block copolymer [1] and the weight fraction wB (wA/wB) preferably falls within a specific range. Specifically, the ratio (wA/wB) is preferably 30/70 or more, more preferably 40/60 or more, particularly preferably 45/55 or more, and more preferably 85/15 or less, further preferably 70/30 or less, particularly preferably 55/45 or less. When the ratio wA/wB is equal to or higher than the lower limit of the range, the rigidity and heat resistance of the second resin layer can be improved, and birefringence can be reduced. Further, when the ratio wA/wB is equal to or less than the upper limit of the range, the flexibility of the second resin layer can be improved. Here, the weight fraction wA of the polymer block [A] indicates the weight fraction of the entire polymer block [A], and the weight fraction wB of the polymer block [B] indicates the entire polymer block [B]. shows the weight fraction of

The weight average molecular weight (Mw) of the block copolymer [1] is preferably 30,000 or more, more preferably 40,000 or more, particularly preferably 50,000 or more, and preferably 200,000 or less. More preferably 150,000 or less, particularly preferably 100,000 or less.
The molecular weight distribution (Mw/Mn) of block copolymer [1] is preferably 3 or less, more preferably 2 or less, particularly preferably 1.5 or less, and preferably 1.0 or more.
The weight-average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of the block copolymer [1] were measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and converted to polystyrene values. measurable.

As a method for producing the block copolymer [1], for example, the methods described in WO 2015/099079 and JP 2016-204217 can be employed.

The hydride [2] is a polymer obtained by hydrogenating the unsaturated bond of the block copolymer [1]. Here, the unsaturated bonds of the block copolymer [1] to be hydrogenated include aromatic and non-aromatic carbon-carbon unsaturation of the main chain and side chains of the block copolymer [1]. Any combination is included.

The hydrogenation rate of the hydride [2] is preferably 90% or higher, more preferably 97% or higher, particularly preferably 99% or higher. Unless otherwise specified, the hydrogenation rate of the hydride [2] is, of the aromatic and non-aromatic carbon-carbon unsaturated bonds of the main chain and side chains of the block copolymer [1], Percentage of hydrogenated bonds. The higher the degree of hydrogenation, the better the transparency, heat resistance and weather resistance of the second resin layer, and the easier it is to reduce the birefringence of the second resin layer. Here, the hydrogenation rate of the hydride [2] can be determined by ¹ H-NMR measurement.

In particular, the hydrogenation rate of non-aromatic carbon-carbon unsaturated bonds is preferably 95% or more, more preferably 99% or more. By increasing the hydrogenation rate of the non-aromatic carbon-carbon unsaturated bonds, the light resistance and oxidation resistance of the second resin layer can be further increased.

Also, the hydrogenation rate of aromatic carbon-carbon unsaturated bonds is preferably 90% or more, more preferably 93% or more, and particularly preferably 95% or more. By increasing the hydrogenation rate of the aromatic carbon-carbon unsaturated bond, the glass transition temperature of the polymer block obtained by hydrogenating the polymer block [A] is increased, so the heat resistance of the second resin layer is improved. can be effectively enhanced. Furthermore, the photoelastic coefficient of resin B can be lowered.

The weight average molecular weight (Mw) of the hydride [2] is preferably 30,000 or more, more preferably 40,000 or more, still more preferably 45,000 or more, and preferably 200,000 or less, more preferably 150,000 or less, even more preferably 100,000 or less. By keeping the weight average molecular weight (Mw) of the hydride [2] within the above range, the mechanical strength and heat resistance of the second resin layer can be improved, and the birefringence of the second resin layer can be reduced. easy.

The molecular weight distribution (Mw/Mn) of hydride [2] is preferably 3 or less, more preferably 2 or less, particularly preferably 1.8 or less, and preferably 1.0 or more. By keeping the molecular weight distribution (Mw/Mn) of the hydride [2] within the above range, the mechanical strength and heat resistance of the second resin layer can be improved, and the birefringence of the second resin layer can be reduced. easy to do

The weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of the hydride [2] can be measured in terms of polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent.

The aforementioned hydride [2] can be produced by hydrogenating the block copolymer [1]. As the hydrogenation method, a hydrogenation method capable of increasing the hydrogenation rate and causing less chain scission reaction of the block copolymer [1] is preferable. Such hydrogenation methods include, for example, the methods described in International Publication No. 2015/099079 and JP-A-2016-204217.

An alkoxysilyl group may be introduced into the hydride [2] contained in the resin B. Among the hydrides [2], alkoxysilyl group-introduced ones are hereinafter sometimes referred to as "alkoxysilyl group-modified products [3]" as appropriate. Due to the introduction of the alkoxysilyl group, the alkoxysilyl group-modified product [3] exhibits high adhesion to other materials. Therefore, since the second resin layer formed of the resin B containing the alkoxysilyl group-modified product [3] has excellent adhesion to the conductive layer, the mechanical strength of the laminate as a whole can be improved. Therefore, by using the alkoxysilyl group-modified product [3], the bending resistance can be particularly improved.

The alkoxysilyl group-modified product [3] is a polymer obtained by introducing an alkoxysilyl group into the hydride [2] of the block copolymer [1] described above. At this time, the alkoxysilyl group may be directly bonded to the hydride [2] described above, or may be indirectly bonded via a divalent organic group such as an alkylene group.

The amount of the alkoxysilyl group introduced in the alkoxysilyl group-modified product [3] is preferably 0.1 parts by weight or more, more preferably 0.1 part by weight, relative to 100 parts by weight of the hydride [2] before the introduction of the alkoxysilyl group. It is 2 parts by weight or more, particularly preferably 0.3 parts by weight or more, preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and particularly preferably 3 parts by weight or less. When the amount of the alkoxysilyl group to be introduced is within the above range, the degree of cross-linking between the alkoxysilyl groups decomposed by moisture or the like can be suppressed from becoming excessively high, so that the adhesion of the second resin layer can be maintained at a high level. can.
The amount of alkoxysilyl groups introduced can be measured by ¹ H-NMR spectrum. When measuring the introduction amount of the alkoxysilyl group, if the introduction amount is small, the measurement can be performed by increasing the number of accumulations.

Since the amount of alkoxysilyl groups to be introduced is small, the weight average molecular weight (Mw) of the alkoxysilyl group-modified product [3] is usually the weight average molecular weight (Mw) of the hydride [2] before introducing the alkoxysilyl group ( Mw) does not change significantly. However, when introducing an alkoxysilyl group, the hydride [2] is usually subjected to a modification reaction in the presence of a peroxide. tends to change significantly. The weight average molecular weight (Mw) of the alkoxysilyl group-modified product [3] is preferably 30,000 or more, more preferably 40,000 or more, even more preferably 45,000 or more, and preferably 200,000 or less. More preferably 150,000 or less, still more preferably 100,000 or less. Further, the molecular weight distribution (Mw/Mn) of the alkoxysilyl group-modified product [3] is preferably 3.5 or less, more preferably 2.5 or less, particularly preferably 2.0 or less, and preferably 1.0. That's it. When the weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of the alkoxysilyl group-modified product [3] are within this range, the second resin layer can maintain good mechanical strength and tensile elongation.
The weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of the alkoxysilyl group-modified product [3] can be measured as polystyrene equivalent values by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent. .

Alkoxysilyl group-modified product [3] can be produced by introducing an alkoxysilyl group into hydride [2] of block copolymer [1] described above. Methods for introducing an alkoxysilyl group into the hydride [2] include, for example, the methods described in International Publication No. 2015/099079 and JP-A-2016-204217.

The proportion of polymer such as hydride [2] (including alkoxysilyl group-modified product [3]) in resin B is preferably 80% to 100% by weight, more preferably 90% to 100% by weight, especially It is preferably 95% to 100% by weight. By keeping the proportion of the polymer in the resin B within the above range, it is easy to keep the storage modulus of the resin B within the range described above.

Resin B may contain optional components in combination with the polymer described above. Examples of the optional component include the same examples as those of the optional component that the resin A may contain. Moreover, arbitrary components may be used individually by 1 type, and may be used in combination of 2 or more types by arbitrary ratios.

The second resin layer usually has high transparency. Specifically, the total light transmittance of the second resin layer is preferably 70% or higher, more preferably 80% or higher, and even more preferably 90% or higher. The haze of the second resin layer is preferably 5% or less, more preferably 3% or less, particularly preferably 1% or less, and ideally 0%.

The thickness of the second resin layer is preferably 1 µm or more, more preferably 10 µm or more, particularly preferably 15 µm or more, and preferably 100 µm or less, more preferably 80 µm or less, and particularly preferably 60 µm or less. When the thickness of the second resin layer is equal to or greater than the lower limit value of the range, the second resin layer can suppress penetration of moisture into the conductive layer. Therefore, deterioration of the conductive layer due to moisture can be effectively suppressed. On the other hand, when the thickness of the second resin layer is equal to or less than the upper limit value of the above range, the stress caused by bending can be reduced, so that the bending resistance of the laminate can be effectively improved.

There is no limitation on the manufacturing method of the second resin layer. Examples of the method for producing the second resin layer include a melt molding method and a solution casting method. Among them, the melt molding method is preferable because it can suppress the residual of volatile components such as a solvent in the second resin layer. Furthermore, in order to obtain a second resin layer excellent in mechanical strength and surface precision, among the melt molding methods, extrusion molding, inflation molding and press molding are preferable, and the second resin layer can be efficiently and easily manufactured. The extrusion molding method is particularly preferable from the viewpoint that it is possible.

[5. any layer]
The layered product may further include any layer in combination with the above-described first resin layer, conductive layer and second resin layer, if necessary. For example, the laminate may have any layer on the side of the first resin layer opposite to the conductive layer, the side of the second resin layer opposite to the conductive layer, or the like. Examples of optional layers include support layers, hard coat layers, index matching layers, adhesive layers, retardation layers, polarizer layers, and optical compensation layers.

[6. Physical properties and thickness of the laminate]
The laminate has excellent folding resistance. Therefore, even when the laminate is repeatedly bent, cracking of the conductive layer and changes in appearance such as whitening can be suppressed. For example, in an embodiment, even when folding is repeated 10,000 times in a folding test described later in Examples, cracking and appearance change of the conductive layer at the folded portion can be suppressed, and preferably the conductive layer Cracks and appearance changes can be eliminated.

The mechanism by which the laminate exhibits such excellent bending resistance as described above is presumed to be as follows. However, the technical scope of the present invention is not limited to the mechanism described below.

The resin B contained in the second resin layer has a storage elastic modulus within an appropriate range, and thus has excellent flexibility. Therefore, when the laminate is bent, the second resin layer is easily deformed and can absorb the stress caused by the bending. Furthermore, since the first resin layer is provided on the opposite side of the conductive layer from the second resin layer with the resin A having an appropriate storage elastic modulus, it is possible to further effectively suppress the concentration of large stress in the conductive layer. . Therefore, cracking of the conductive layer due to stress generated by bending can be effectively suppressed.
In addition, since the first resin layer and the second resin layer have a storage modulus within an appropriate range, the first resin layer and the second resin layer are unlikely to break when the laminate is bent. Furthermore, due to the action of an appropriate storage elastic modulus, peeling between the first resin layer and the conductive layer and peeling between the second resin layer and the conductive layer are less likely to occur. Therefore, since minute voids due to the breakage or peeling described above are less likely to occur, the haze is less likely to increase at the bent portion, and thus changes in appearance such as whitening are suppressed.

Since the laminate includes the first resin layer and the second resin layer having flexibility as layers for supporting the conductive layer, it is usually superior in impact resistance and workability as compared to conductive glass. Additionally, laminates are typically lighter than conductive glass.

From the viewpoint of using the laminate as an optical member, the total light transmittance of the laminate is preferably 70% or higher, more preferably 80% or higher, and even more preferably 90% or higher.
In addition, the haze of the laminate is preferably 5% or less, more preferably 3% or less, particularly preferably 1% or less, from the viewpoint of improving the image clarity of an image display device incorporating the laminate. is 0%.

The thickness of the laminate is preferably 2 µm or more, more preferably 5 µm or more, still more preferably 7.5 µm or more, particularly preferably 10 µm or more, and preferably 200 µm or less, more preferably 175 µm or less, and particularly preferably 150 µm or less. be. When the thickness of the laminate is at least the lower limit of the above range, the mechanical strength of the laminate can be increased, and wrinkles can be prevented when the conductive layer is formed. Moreover, when the thickness of the laminate is equal to or less than the upper limit of the above range, the bending resistance of the laminate can be particularly improved, and the thickness of the laminate can be reduced.

[7. Laminate manufacturing method]
There are no restrictions on the method of manufacturing the laminate. For example, from the viewpoint of easily manufacturing the above-described laminate, the laminate includes a step of preparing a first resin layer; a step of forming a conductive layer on the first resin layer; It is preferable to manufacture by a manufacturing method including the step of forming a resin layer.

In the step of preparing the first resin layer, for example, the first resin layer is formed from the resin A by the method for manufacturing the first resin layer described above.

In the step of forming the conductive layer, for example, the conductive layer is formed on the first resin layer by the method of forming the conductive layer described above. The conductive layer may be indirectly formed on the first resin layer via any layer. However, the conductive layer is preferably formed directly on the first resin layer. Here, "directly" in which another layer is formed on a certain layer means that there is no other layer between these two layers.

In the step of forming the second resin layer, the second resin layer is formed on the opposite side of the conductive layer to the first resin layer. The second resin layer may be indirectly formed on the conductive layer via any layer. For example, after preparing the second resin layer by the method for manufacturing the second resin layer described above, the second resin layer may be attached to the conductive layer via a pressure-sensitive adhesive or an adhesive. However, the second resin layer is preferably formed directly on the conductive layer. For example, the second resin layer can be formed directly on the conductive layer by pressing the second resin layer onto the surface of the conductive layer while heating as necessary. Alternatively, for example, the second resin layer can be formed directly on the conductive layer by applying a coating liquid containing the resin B and a solvent onto the conductive layer and drying it as necessary.

The method for manufacturing a laminate may further include optional steps in combination with the steps described above.

[8. touch panel]
The laminate described above can be used for various optical applications. A laminate can be used, for example, as a member of a touch panel. Since the laminate has excellent bending resistance, it is particularly suitable for a flexible touch panel.

In the touch panel provided with the laminate, the orientation of the laminate is arbitrary. For example, in the touch panel, the first resin layer, the conductive layer, and the second resin layer may be provided in this order from the viewing side. Further, for example, in the touch panel, the second resin layer, the conductive layer, and the first resin layer may be provided in this order from the viewing side.

In general, it is considered that a touch panel is often used in a curved state with the viewing side surface facing outward. Therefore, it is preferable to set the direction of the laminated body provided in the touch panel so that a bendable touch panel can be obtained with the viewing side surface facing outward. As described above, the laminate generally has high resistance to bending with the first resin layer side facing outward. Therefore, in order to make the laminate bendable with the viewer side surface of the laminate facing outward, the orientation of the laminate is such that the first resin layer, the conductive layer, and the second resin layer are arranged in this order from the viewer side. It is preferable to set it so that it is provided. Thereby, it is possible to obtain a touch panel that can be bent with the viewing side surface facing outward.

A touch panel usually includes an image display element combined with a laminate. Examples of image display devices include liquid crystal display devices and organic electroluminescence display devices (hereinafter sometimes referred to as “organic EL display devices” as appropriate). Usually, the laminate is provided on the viewing side of the image display element.

In order to obtain a flexible touch panel, it is preferable to employ a flexible image display element (flexible display element) as the image display element. An example of such a flexible image display element is an organic EL display element.

An organic EL display element usually comprises a first electrode layer, a light emitting layer and a second electrode layer in this order on a substrate, and the light emitting layer emits light when a voltage is applied from the first electrode layer and the second electrode layer. can occur. Examples of materials constituting the organic light-emitting layer include polyparaphenylenevinylene-based, polyfluorene-based, and polyvinylcarbazole-based materials. Further, the light-emitting layer may have a laminate of layers emitting light of different colors, or a mixed layer in which a certain dye layer is doped with a different dye. Furthermore, the organic EL display element may include functional layers such as a barrier layer, a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, an equipotential surface formation layer, and a charge generation layer.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the examples shown below, and can be arbitrarily modified without departing from the scope of the claims of the present invention and their equivalents.

In the following description, "%" and "parts" representing amounts are by weight unless otherwise specified. In the following description, unless otherwise specified, "sccm" is the unit of gas flow rate, and the amount of gas flowing per minute is the volume (cm ³ ). Further, the operations described below were performed under normal temperature and pressure conditions unless otherwise specified.

[Evaluation method]
[Method for measuring molecular weight]
The weight average molecular weight and number average molecular weight of the polymer were measured by gel permeation chromatography using tetrahydrofuran as an eluent and converted to standard polystyrene at 38°C. As a measuring device, HLC8320GPC manufactured by Tosoh Corporation was used.

[Method for measuring hydrogenation rate]
The hydrogenation rate of the polymer was measured by ¹ H-NMR measurement.

[Measurement method of glass transition temperature Tg and melting point Mp]
Using a differential scanning calorimeter (DSC), the temperature was raised at 10°C/min to determine the glass transition temperature Tg and melting point Mp of the sample.

[Method for Measuring Ratio of Racemo Diad in Polymer]
Using ortho-dichlorobenzene-d ⁴ /1,2,4-trichlorobenzene (TCB)-d ₃ (mixing ratio (mass basis) 1/2) as a solvent, at 200 ° C., applying an inverse-gated decoupling method, ¹³ C-NMR measurement of the polymer was performed. From the results of this ¹³ C-NMR measurement, a 43.35 ppm signal derived from the meso dyad and a 43.43 ppm signal derived from the racemo dyad, with the 127.5 ppm peak of ortho-dichlorobenzene-d ⁴ as the standard shift. identified. Based on the intensity ratio of these signals, the proportion of racemo dyads in the polymer was determined.

[Method for measuring storage modulus of resin]
A measuring film having a thickness of 1 mm was obtained from the resin as a sample by an extrusion molding method. For this measurement film, the storage modulus at 25° C. was measured using a dynamic viscoelasticity measuring device (“ARES” manufactured by TA Instruments) under the measurement conditions of shear mode and frequency of 1 Hz.

[Evaluation of bending resistance by folding test]
A folding test was performed on the laminated film. In this folding test, a bending tester (“TCDM111LH” manufactured by Yuasa Systems Co., Ltd.) was used to perform folding operation 10,000 times on the laminated film with a radius of curvature of 5 mm. After that, the laminated film was visually observed and evaluated according to the following criteria.
"Good": No change from before the test. Alternatively, a slightly white portion can be seen in the laminated film.
"Poor": The laminated film is whitened. Alternatively, the laminated film cracks during the test.

[Evaluation method of dimensional change due to conductive layer formation by sputtering]
Regarding Examples 1, 2 and 4 to 7 and Comparative Examples 1 and 2 in which an ITO layer was formed as a conductor layer on the first resin layer by sputtering, whether the formation of the conductive layer by sputtering caused a dimensional change in the first resin layer. evaluated what Specifically, the length and width of the first resin layer were measured before and after sputtering. It was then investigated whether the measured length and width would change due to sputtering.

For reference, in Example 3 as well, it was evaluated whether or not the formation of the conductive layer caused a dimensional change in the first resin layer. Specifically, the length and width of the first resin layer were measured before and after drying the dispersion applied on the first resin layer at 120°C. Then, it was investigated whether the measured length and width changed due to drying.

[Production Example 1: Production of Si-modified resin containing alkoxysilyl group-modified product of block copolymer hydride]
(First step: elongation of first block St by polymerization reaction)
550 parts of dehydrated cyclohexane, 25 parts of styrene, and 0.475 parts of dibutyl ether were charged into a sufficiently dried and nitrogen-substituted stainless steel reactor equipped with a stirrer, and n-butyllithium was stirred at 60°C. 0.68 part of the solution (15% by weight hexane solution) was added to initiate the polymerization reaction, and the first-stage polymerization reaction was carried out. One hour after the initiation of the reaction, a sample was sampled from the reaction mixture and analyzed by gas chromatography (GC). As a result, the polymerization conversion rate was 99.5%.

(Second step: elongation of second block Ip by polymerization reaction)
50 parts of dehydrated isoprene was added to the reaction mixture obtained in the first step, and stirring was continued for 30 minutes. Subsequently, the second-stage polymerization reaction was started. One hour after initiation of the polymerization reaction in the second stage, a sample was sampled from the reaction mixture and analyzed by GC to find that the polymerization conversion rate was 99.5%.

(Third step: elongation of third block St by polymerization reaction)
25 parts of dehydrated styrene was added to the reaction mixture obtained in the second step, and then the polymerization reaction in the third step was started. One hour after initiation of the polymerization reaction in the third stage, a sample was sampled from the reaction mixture and the weight average molecular weight Mw and number average molecular weight Mn of the block copolymer were measured. Further, the sample sampled at this time was analyzed by GC, and the polymerization conversion rate was almost 100%. Immediately thereafter, 0.5 part of isopropyl alcohol was added to the reaction mixture to stop the reaction. A mixture containing a block copolymer was thus obtained.

The obtained block copolymer was found to be a polymer having a triblock molecular structure of 1st block St-2nd block Ip-3rd block St=25-50-25 (weight ratio). The block copolymer had a weight average molecular weight (Mw) of 47200 and a molecular weight distribution (Mw/Mn) of 1.05.

(Fourth step: hydrogenation of block copolymer)
Next, the mixture containing the above block copolymer is transferred to a pressure-resistant reactor equipped with a stirring device, and a diatomaceous earth-supported nickel catalyst (“T-8400RL” manufactured by Süd Chemie Catalyst Co., Ltd.) 3.0 as a hydrogenation catalyst. parts and 100 parts of dehydrated cyclohexane were added and mixed. The inside of the reactor was replaced with hydrogen gas, hydrogen was supplied while stirring the solution, and a hydrogenation reaction was carried out at a temperature of 190° C. and a pressure of 4.5 MPa for 8 hours. The hydrogenated block copolymer contained in the reaction solution obtained by the hydrogenation reaction had a weight average molecular weight (Mw) of 49,900 and a molecular weight distribution (Mw/Mn) of 1.06.

(Step 5: Removal of volatile components)
After completion of the hydrogenation reaction, the reaction solution was filtered to remove the hydrogenation catalyst. Thereafter, a phenolic antioxidant pentaerythrityl tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (“Songnox 1010” manufactured by Matsubara Sangyo Co., Ltd.) was added to the reaction solution. 2.0 parts of xylene solution in which 1 part was dissolved was added and dissolved.
Then, from the above reaction solution, using a cylindrical concentration dryer ("Control" manufactured by Hitachi, Ltd.) at a temperature of 260 ° C. and a pressure of 0.001 MPa or less, the solvent cyclohexane, xylene and other volatile components are removed. bottom. The melted polymer was extruded through a die in the form of a strand, and after cooling, a pelletizer was used to prepare pellets of the resin containing the hydride of the block copolymer.
The weight-average molecular weight (Mw) of the hydrogenated block copolymer contained in the obtained resin pellets was 49,500, the molecular weight distribution (Mw/Mn) was 1.10, and the hydrogenation rate was almost 100%.

(Step 6: Modification with Ethylenically Unsaturated Silane Compound)
Per 100 parts of the resin pellets, 3.0 parts of vinyltrimethoxysilane and 2,5-dimethyl-2,5-di(t-butylperoxy)hexane ("Perhexa (registered trademark)" manufactured by NOF Corporation) 25B") was added to give a mixture. This mixture was kneaded using a twin-screw extruder at a resin temperature of 220° C. and a residence time of 60 to 70 seconds, and extruded into strands. After the extruded mixture was air-cooled, it was cut by a pelletizer to obtain 96 parts of resin pellets containing an alkoxysilyl group-modified hydrogenated block copolymer.

10 parts of resin pellets containing an alkoxysilyl group-modified product were dissolved in 100 parts of cyclohexane to obtain a solution. This solution was poured into 400 parts of dehydrated methanol to coagulate the alkoxysilyl group-modified product, and the coagulate was collected by filtration. The filtrate was vacuum-dried at 25° C. to isolate 9.0 parts of crumbs of the alkoxysilyl group-modified product.
When the FT-IR spectrum of the alkoxysilyl group-modified product was measured, new absorption bands derived from Si—OCH ₃ groups at 1090 cm ⁻¹ and Si—CH ₂ groups at 825 cm ⁻¹ and 739 cm ⁻¹ were found to be vinyltrimethoxy Si—OCH ₃ groups of silane were observed at positions different from absorption bands (1075 cm ⁻¹ , 808 cm ⁻¹ and 766 cm ⁻¹ ) derived from Si—CH groups.
Further, when the ¹ H-NMR spectrum (in deuterated chloroform) of the alkoxysilyl group-modified product was measured, a peak due to protons of the methoxy group was observed at 3.6 ppm. From this peak area ratio, it was confirmed that 1.8 parts of vinyltrimethoxysilane were bonded to 100 parts of the hydride of the block copolymer before modification.
The resin containing the alkoxysilyl group-modified product thus obtained is appropriately referred to as hydrogenated block resin X1.

[Production Example 2: Production of Si-modified resin containing alkoxysilyl group-modified product of hydrogenated block copolymer]
(First to Third Stages: Production of Block Copolymer by Polymerization Reaction)
The amount of styrene charged in the first stage was changed from 25 parts to 30 parts. Also, the amount of the n-butyllithium solution (15% by weight hexane solution) charged in the first step was changed from 0.68 parts to 0.61 parts. Furthermore, the amount of isoprene charged in the second stage was changed from 50 parts to 40 parts. Also, the amount of styrene charged in the third stage was changed from 25 parts to 30 parts. Except for the above, the same operations as (first step) to (third step) of Production Example 1 were performed to obtain a mixture containing a block copolymer. The obtained block copolymer had a weight average molecular weight (Mw) of 80,400, a molecular weight distribution (Mw/Mn) of 1.03, and wA/wB = 60/40.

(Fourth step: hydrogenation of block copolymer)
Next, the above block copolymer was hydrogenated by the same operation as in Production Example 1 (fourth step). The hydrogenated block copolymer contained in the reaction solution obtained by the hydrogenation reaction had a weight average molecular weight (Mw) of 80,400 and a molecular weight distribution (Mw/Mn) of 1.04.

(Step 5: Removal of volatile components)
By the same operation as in Production Example 1 (fifth step), an antioxidant was added to the hydride of the block copolymer and concentration and drying were performed to obtain 95 parts of resin pellets containing the hydride of the block copolymer. made.
The weight average molecular weight (Mw) of the hydrogenated block copolymer contained in the obtained resin pellets was 80,200, the molecular weight distribution (Mw/Mn) was 1.04, and the hydrogenation rate was almost 100%. rice field.

(Step 6: Modification with Ethylenically Unsaturated Silane Compound)
Using the pellets of the above resin, the same operation as in Production Example 1 (Step 6) was performed to obtain a resin containing an alkoxysilyl group-modified hydrogenated block copolymer. The resin containing the alkoxysilyl group-modified product thus obtained is appropriately referred to as hydrogenated block resin X2.

[Production Example 3: Production of Si-modified resin containing alkoxysilyl group-modified hydride of block copolymer]
(First to Third Stages: Production of Block Copolymer by Polymerization Reaction)
The amount of styrene charged in the first stage was changed from 25 to 35 parts. Also, the amount of the n-butyllithium solution (15% by weight hexane solution) charged in the first step was changed from 0.68 parts to 0.32 parts. Furthermore, the amount of isoprene charged in the second stage was changed from 50 parts to 30 parts. Also, the amount of styrene charged in the third stage was changed from 25 parts to 35 parts. Except for the above, the same operations as (first step) to (third step) of Production Example 1 were performed to obtain a mixture containing a block copolymer. The obtained block copolymer had a weight average molecular weight (Mw) of 141,000, a molecular weight distribution (Mw/Mn) of 1.04, and wA/wB=70/30.

(Fourth step: hydrogenation of block copolymer)
Next, the above block copolymer was hydrogenated by the same operation as in Production Example 1 (fourth step). The hydrogenated block copolymer contained in the reaction solution obtained by the hydrogenation reaction had a weight average molecular weight (Mw) of 143,000 and a molecular weight distribution (Mw/Mn) of 1.06.

(Step 5: Removal of volatile components)
Addition of the antioxidant to the hydride of the block copolymer and concentration and drying were carried out in the same manner as in Production Example 1 (Step 5), except that the temperature of the concentration dryer was changed from 260°C to 270°C. 88 parts of resin pellets containing a hydrogenated block copolymer were prepared.
The weight-average molecular weight (Mw) of the hydrogenated block copolymer contained in the obtained resin pellets was 142,000, the molecular weight distribution (Mw/Mn) was 1.41, and the hydrogenation rate was almost 100%. rice field.

(Step 6: Modification with Ethylenically Unsaturated Silane Compound)
Using the pellets of the above resin, the same operation as in Production Example 1 (Step 6) was performed to obtain a resin containing an alkoxysilyl group-modified hydrogenated block copolymer. The resin containing the alkoxysilyl group-modified product thus obtained is appropriately referred to as hydrogenated block resin X3.

[Production Example 4: Production of crystalline resin COP2 containing hydride of ring-opening polymer of dicyclopentadiene]
After sufficiently drying the metal pressure-resistant reactor, the atmosphere was replaced with nitrogen. Into this pressure-resistant reactor, 154.5 parts of cyclohexane, 42.8 parts of a 70% cyclohexane solution of dicyclopentadiene (endo body content of 99% or more) (30 parts as the amount of dicyclopentadiene), and 1-hexene 1.9 parts was added and warmed to 53°C.

A solution was prepared by dissolving 0.014 parts of tetrachlorotungstenphenylimide (tetrahydrofuran) complex in 0.70 parts of toluene. To this solution, 0.061 part of a 19% diethylaluminum ethoxide/n-hexane solution was added and stirred for 10 minutes to prepare a catalyst solution.
This catalyst solution was added to the pressure reactor to initiate the ring-opening polymerization reaction. Thereafter, the mixture was allowed to react for 4 hours while maintaining the temperature at 53° C. to obtain a solution of a ring-opening polymer of dicyclopentadiene.
The obtained ring-opening polymer of dicyclopentadiene had a number average molecular weight (Mn) and a weight average molecular weight (Mw) of 8,750 and 28,100, respectively. was 3.21.

0.037 parts of 1,2-ethanediol was added as a terminator to 200 parts of the obtained solution of the ring-opening polymer of dicyclopentadiene, heated to 60° C., and stirred for 1 hour to terminate the polymerization reaction. let me 1 part of a hydrotalcite-like compound (“Kyoward (registered trademark) 2000” manufactured by Kyowa Chemical Industry Co., Ltd.) was added thereto, heated to 60° C., and stirred for 1 hour. After that, 0.4 part of a filter aid ("Radiolite (registered trademark) #1500" manufactured by Showa Kagaku Kogyo Co., Ltd.) is added, and a PP pleated cartridge filter ("TCP-HX" manufactured by ADVANTEC Toyo Co., Ltd.) is used as an adsorbent. The solution was filtered off.

To 200 parts of the solution of the ring-opening polymer of dicyclopentadiene after filtration (polymer amount: 30 parts), 100 parts of cyclohexane was added, 0.0043 parts of chlorohydridocarbonyltris(triphenylphosphine)ruthenium was added, and hydrogen was added. A hydrogenation reaction was carried out at a pressure of 6 MPa and 180° C. for 4 hours. As a result, a reaction liquid containing a hydride of a ring-opening polymer of dicyclopentadiene was obtained. This reaction solution was a slurry solution due to deposition of hydride.

The hydride contained in the reaction solution and the solution were separated using a centrifugal separator and dried under reduced pressure at 60° C. for 24 hours to obtain a crystalline hydride of a ring-opening polymer of dicyclopentadiene 28. 5 copies were obtained. This hydride had a hydrogenation rate of 99% or more, a glass transition temperature Tg of 93°C, a melting point Mp of 262°C, and a racemo dyad ratio of 89%.

An antioxidant (tetrakis[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane) was added to 100 parts of the hydride of the resulting ring-opening polymer of dicyclopentadiene. ; After mixing 1.1 parts of BASF Japan's "Irganox (registered trademark) 1010"), a twin-screw extruder equipped with four die holes with an inner diameter of 3 mmΦ ("TEM-37B" manufactured by Toshiba Machine Co., Ltd.) put in. The resin was molded into strands by hot-melt extrusion molding using a twin-screw extruder, and then chopped with a strand cutter to obtain pellets of the crystalline resin COP2. This crystalline resin COP2 is a resin (glass transition temperature: 92° C., melting point Mp: 260° C.) containing a hydride of a ring-opening polymer of dicyclopentadiene as a crystalline alicyclic structure-containing polymer.
The operating conditions of the twin-screw extruder were as follows.
- Barrel set temperature = 270°C to 280°C.
• Die set temperature = 250°C.
- Screw rotation speed = 145 rpm.
- Feeder rotation speed = 50 rpm.

[Example 1]
(1-1. Preparation of first resin layer)
As the first resin layer, a resin film (“Zeonor Film ZF16” manufactured by Nippon Zeon Co., Ltd.; thickness 50 μm; resin glass transition temperature 160° C.) formed of a norbornene-based polymer as an alicyclic structure-containing polymer was prepared. .

(1-2. Formation of conductive layer)
The surface of the first resin layer was subjected to corona treatment in air at a discharge amount of 150 W/m ² /min. An ITO layer having a thickness of 25 nm was formed as a conductive layer by performing sputtering on the corona-treated surface of the first resin layer using a film winding type magnetron sputtering apparatus. The sputtering was performed using baked tin oxide and indium oxide as targets, an argon (Ar) flow rate of 150 sccm, an oxygen (O ₂ ) flow rate of 10 sccm, an output of 4.0 kW, a degree of vacuum of 0.3 Pa, and a film transport speed of 0. .5 m/min. As a result, a multilayer film including the first resin layer and the conductive layer was obtained.

(1-3. Formation of second resin layer)
The hydrogenated block resin X1 produced in Production Example 1 was extruded into a film to obtain a film as a second resin layer having a thickness of 50 μm. This second resin layer was thermally laminated to the conductive layer side surface of the multilayer film using a vacuum laminator ("PVL0505S" manufactured by Nisshinbo Mechatronics Co., Ltd.). Specifically, this thermal lamination was performed according to the following procedure.
A second resin layer was placed on top of the conductive layer of the multilayer film. The multilayer film and the second resin layer were preheated at a temperature of 150° C. for 5 minutes under reduced pressure. After that, the multilayer film and the second resin layer were crimped for 10 minutes at a temperature of 150° C. and a pressure of 0.03 MPa.
As a result, a laminated film comprising the first resin layer/conductive layer/second resin layer was obtained. This laminated film was evaluated by the method described above. As a result of the folding test, there was no change in the folding portion.

[Example 2]
A stretched film having a thickness of 13 μm was obtained by stretching the resin film prepared as the first resin layer in Example 1 at a temperature of 180°C. This resin film was used as the first resin layer.
Also, by changing the extrusion molding conditions, the thickness of the film of the hydrogenated block resin X1 as the second resin layer was changed to 5 μm.
A laminated film comprising the first resin layer/conductive layer/second resin layer was manufactured and evaluated by the same operations as in Example 1 except for the above items. As a result of the folding test, there was no change in the folding portion.

[Example 3]
As a conductive nanowire dispersion, a dispersion containing silver nanowires (“Clear Ohm” manufactured by Cambrios Technologies Corporation) was prepared. Using a bar coater, the above dispersion was applied onto the same first resin layer as used in Example 1 and dried at 120°C. As a result, a conductive layer having a thickness of 1 μm was formed on the first resin layer to obtain a multilayer film including the first resin layer and the conductive layer. On this multilayer film, a second resin layer is thermally laminated by the same method as the method of forming the second resin layer in Example 1 to obtain a laminated film comprising a first resin layer/a conductive layer/a second resin layer. Obtained. This laminated film was evaluated by the method described above. As a result of the folding test, there was no change in the folding portion.

[Example 4]
Resin pellets of a norbornene-based polymer (“Zeonor” manufactured by Nippon Zeon Co., Ltd.; glass transition temperature: 126° C.) were prepared as an alicyclic structure-containing polymer. The resin pellets were molded using a T-die type film extruder to obtain a resin film having a thickness of 50 μm. A laminated film comprising the first resin layer/conductive layer/second resin layer was produced and evaluated in the same manner as in Example 1, except that this resin film was used as the first resin layer. As a result of the folding test, there was no change in the folding portion.

[Example 5]
A stretched film having a thickness of 40 μm was obtained by stretching the resin film prepared as the first resin layer in Example 1 at a temperature of 180°C. This resin film was used as the first resin layer.
Further, the hydrogenated block resin X2 produced in Production Example 2 was extruded into a film shape to obtain a film having a thickness of 50 μm. A film of this hydrogenated block resin X2 was used as the second resin layer.
A laminated film comprising the first resin layer/conductive layer/second resin layer was manufactured and evaluated by the same operations as in Example 1 except for the above items. As a result of the folding test, there was no change in the folding portion.

[Example 6]
A stretched film having a thickness of 30 μm was obtained by stretching the resin film prepared as the first resin layer in Example 1 at a temperature of 180°C. This resin film was used as the first resin layer.
Further, the hydrogenated block resin X3 produced in Production Example 3 was extruded into a film shape to obtain a film having a thickness of 30 μm. A film of this hydrogenated block resin X3 was used as the second resin layer.
A laminated film comprising the first resin layer/conductive layer/second resin layer was manufactured and evaluated by the same operations as in Example 1 except for the above items. As a result of the folding test, there was no change in the folding portion.

[Example 7]
Pellets of the crystalline resin COP2 produced in Production Example 4 were molded using a T-die film extruder to obtain a resin film having a thickness of 50 μm. A laminated film comprising the first resin layer/conductive layer/second resin layer was produced and evaluated in the same manner as in Example 1, except that this resin film was used as the first resin layer. As a result of the folding test, there was no change in the folding portion.

[Comparative Example 1]
As the second resin layer, the same resin film as used as the first resin layer in Example 1 was used. A laminate film comprising the first resin layer/conductive layer/second resin layer was manufactured and evaluated by the same operation as in Example 1 except for the above items. As a result of the folding test, cracks occurred in the first resin layer, the second resin layer and the conductive layer after 1000 folding times. In addition, after the folding test, the folded portion turned white.

[Comparative Example 2]
(Formation of conductive layer)
A polyethylene terephthalate film ("Lumirror T-60" manufactured by Toray Industries, Inc., thickness 38 μm, storage modulus at 25° C. 4000 MPa, melting point Mp 260° C., glass transition temperature 70° C.) was used instead of the resin film formed of a norbornene-based polymer. It was used as the first resin layer. A conductive layer was formed on the first resin layer by the same method as the method for forming the conductive layer in Example 1, except for the above matters, to obtain a multilayer film comprising the first resin layer and the conductive layer.

(Formation of adhesive layer corresponding to second resin layer)
67 parts by weight of butyl acrylate, 14 parts by weight of cyclohexyl acrylate, 27 parts by weight of 4-hydroxybutyl acrylate, 9 parts by weight of hydroxyethyl acrylate, 0.05 parts by weight of photopolymerization initiator (manufactured by BASF "Irgacure 651"), and light A monomer mixture was obtained by mixing 0.05 part by weight of a polymerization initiator ("Irgacure 184" manufactured by BASF). This monomer mixture was partially photopolymerized by exposing it to ultraviolet rays in a nitrogen atmosphere to obtain a partially polymerized product (acrylic polymer syrup) having a polymerization rate of about 10% by weight. To 100 parts by weight of the obtained partial polymer, 0.15 parts by weight of dipentaerythritol hexaacrylate ("KAYARAD DPHA" manufactured by Nippon Kayaku Co., Ltd.), 0.15 parts by weight of a silane coupling agent ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) .3 parts by weight were added and uniformly mixed to obtain an acrylic pressure-sensitive adhesive composition.

The above acrylic pressure-sensitive adhesive composition was applied onto the release-treated surface of a release film ("Diafoil MRF #38" manufactured by Mitsubishi Plastics, Inc.) so that the thickness after forming the pressure-sensitive adhesive layer was 100 μm. to form an adhesive composition layer. Next, a release film (“Diafoil MRN#38” manufactured by Mitsubishi Plastics, Inc.) was coated on the surface of the adhesive composition layer so that the release-treated surface of the release film faced the adhesive composition layer. . This shielded the pressure-sensitive adhesive composition layer from oxygen.

After that, the pressure-sensitive adhesive composition layer is irradiated with ultraviolet rays under the conditions of an illuminance of 5 mW/cm ² and a light amount of 1500 mJ/cm ² , and the pressure-sensitive adhesive composition layer is photocured to form a release film/adhesive layer/release film. A pressure-sensitive adhesive sheet was obtained. A release film coated on both sides of the pressure-sensitive adhesive layer functions as a release liner. The weight average molecular weight (Mw) of the acrylic polymer used as the base polymer of the pressure-sensitive adhesive layer was 2,000,000.

The release film on one side of the adhesive sheet was peeled off. The surface of the pressure-sensitive adhesive layer exposed by peeling was attached to the conductive layer of the multilayer film. After that, the other release film was peeled off to obtain a laminated film having an adhesive layer corresponding to the first resin layer/conductive layer/second resin layer. This laminated film was evaluated by the method described above. As a result of the folding test, the folding part turned white.

[result]
The results of the above Examples and Comparative Examples are shown in Table 1 below. In the table below, the abbreviations have the following meanings.
"COP": Norbornene-based polymer.
"COP2": Crystalline resin COP2.
"PET": polyethylene terephthalate.
"Silver Nano": Silver nanowires.
"Resin X1": Hydrogenated block resin X1 containing an alkoxysilyl group-modified hydrogenated block copolymer.
"Resin X2": Hydrogenated block resin X2 containing an alkoxysilyl group-modified product of a hydrogenated block copolymer.
"Resin X3": Hydrogenated block resin X3 containing an alkoxysilyl group-modified product of a hydrogenated block copolymer.
"Tg": glass transition temperature.

REFERENCE SIGNS LIST 10 laminate 110 first resin layer 110D first resin layer side surface of laminate 120 conductive layer 130 second resin layer 130U second resin layer side surface of laminate

Claims (7)

A laminate for a touch panel comprising, in this order, a first resin layer made of resin A, a conductive layer, and a second resin layer made of resin B,
The storage modulus of the resin A at 25° C. is 500 MPa or more and 20000 MPa or less,
The storage modulus of the resin B at 25° C. is 10 MPa or more and 1000 MPa or less ,
A laminate in which the resin A contains a polymer having a melting point and containing an alicyclic structure . The thickness of the first resin layer is 1 μm or more and 100 μm or less,
The laminate according to claim 1, wherein the second resin layer has a thickness of 1 µm or more and 100 µm or less. 3. The laminate according to claim 1, wherein the resin B contains a hydrogenated block copolymer into which an alkoxysilyl group may be introduced. The laminate according to any one of claims 1 to 3, wherein the resin A has a glass transition temperature of 130°C or higher. The laminate according to any one of claims 1 to 4, wherein the conductive layer contains at least one conductive material selected from the group consisting of metals, conductive metal oxides, conductive nanowires and conductive polymers. . A touch panel comprising the laminate according to any one of claims 1 to 5 so that the first resin layer, the conductive layer and the second resin layer are provided in this order from the viewing side,
The touch panel, wherein the laminated body can be bent with the viewing side surface facing outward. A method for producing a laminate according to any one of claims 1 to 5,
preparing a first resin layer;
forming a conductive layer on the first resin layer;
and forming a second resin layer on the conductive layer.

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