阅读说明：本技术 层叠体及其制造方法以及触控面板 (Laminate, method for manufacturing same, and touch panel ) 是由 三浦拓也 于 2019-01-30 设计创作，主要内容包括：本发明提供了一种层叠体,其依次具有由树脂A形成的第1树脂层、导电层及由树脂B形成的第2树脂层,在25℃时,上述树脂A的储能模量为500MPa以上且20000MPa以下,在25℃时,上述树脂B的储能模量为10MPa以上且1000MPa以下。(The present invention provides a laminate comprising a 1 st resin layer made of a resin A, an electrically conductive layer, and a 2 nd resin layer made of a resin B in this order, wherein the storage modulus of the resin A is 500MPa or more and 20000MPa or less at 25 ℃, and the storage modulus of the resin B is 10MPa or more and 1000MPa or less at 25 ℃.)

1. A laminate comprising a 1 st resin layer made of a resin A, a conductive layer and a 2 nd resin layer made of a resin B in this order,

the resin A has a storage modulus of 500MPa or more and 20000MPa or less at 25 ℃,

the resin B has a storage modulus of 10MPa or more and 1000MPa or less at 25 ℃.

2. The laminate according to claim 1, wherein the thickness of the 1 st resin layer is 1 μm or more and 100 μm or less,

the thickness of the 2 nd resin layer is 1 μm or more and 100 μm or less.

3. The laminate according to claim 1 or 2, wherein the resin A comprises a polymer containing an alicyclic structure,

the resin B contains a block copolymer hydride capable of introducing an alkoxysilyl group.

4. The laminate according to any one of claims 1 to 3, wherein the glass transition temperature of the resin A is 130 ℃ or higher.

5. The laminate according to any one of claims 1 to 4, wherein the conductive layer comprises at least 1 conductive material selected from a metal, a conductive metal oxide, a conductive nanowire and a conductive polymer.

6. A touch panel comprising the laminate according to any one of claims 1 to 5, wherein the laminate comprises a 1 st resin layer, a conductive layer and a 2 nd resin layer in this order from the viewing side,

the laminate can be bent with the viewing side surface as the outer side.

7. A method for producing a laminate according to any one of claims 1 to 5, comprising:

preparing a 1 st resin layer;

forming a conductive layer on the 1 st resin layer;

and a step of forming a 2 nd resin layer on the conductive layer.

Technical Field

The invention relates to a laminate, a method for manufacturing the same, and a touch panel.

Background

Conventionally, as a transparent conductive member, a conductive glass in which an indium oxide thin film is formed on a glass plate has been known. However, since the base material of the conductive glass is glass, the conductive glass has poor flexibility and is difficult to apply to a corresponding application. Therefore, a laminate using a resin has been proposed as a transparent conductive member having excellent flexibility (patent document 1).

Disclosure of Invention

Problems to be solved by the invention

The laminate described in patent document 1 includes a flexible base material, a conductive layer formed on the flexible base material, and a binder layer formed on the conductive layer. However, such a conventional laminate has insufficient bending resistance. Specifically, in the case of a conventional laminate, when the folding operation is repeated, whitening or cracking of the conductive layer tends to occur at the folding portion. Therefore, further improvement in the bending resistance is required.

The present invention has been made in view of the above problems, and an object thereof is to provide a laminate having excellent bending resistance and a method for producing the same; and a touch panel having the laminate.

Means for solving the problems

The present inventors have conducted intensive studies in order to solve the above problems. As a result, the present inventors have found that a laminate having a 1 st resin layer formed of a resin a, an electrically conductive layer, and a 2 nd resin layer formed of a resin B in this order, and both the resin a and the resin B having a predetermined storage modulus, can suppress a change in appearance and cracking of the electrically conductive layer when bending operations are repeated, and have completed the present invention.

That is, the present invention includes the following.

[1] A laminate comprising a 1 st resin layer made of a resin A, a conductive layer and a 2 nd resin layer made of a resin B in this order,

the resin A has a storage modulus of 500MPa or more and 20000MPa or less at 25 ℃,

the resin B has a storage modulus of 10MPa or more and 1000MPa or less at 25 ℃.

[2] The laminate according to [1], wherein the thickness of the 1 st resin layer is 1 μm or more and 100 μm or less,

the thickness of the 2 nd resin layer is 1 μm or more and 100 μm or less.

[3] The laminate according to [1] or [2], wherein the resin A comprises a polymer containing an alicyclic structure,

the resin B contains a block copolymer hydride into which an alkoxysilyl group can be introduced.

[4] The laminate according to any one of [1] to [3], wherein the glass transition temperature of the resin A is 130 ℃ or higher.

[5] The laminate according to any one of [1] to [4], wherein the conductive layer contains at least 1 conductive material selected from a metal, a conductive metal oxide, a conductive nanowire and a conductive polymer.

[6] A touch panel comprising the laminate according to any one of [1] to [5] so that a 1 st resin layer, a conductive layer and a 2 nd resin layer are provided in this order from a viewing side,

the laminate can be bent with the viewing side surface as the outer side.

[7] A method for producing a laminate according to any one of [1] to [5], comprising:

preparing a 1 st resin layer;

forming a conductive layer on the 1 st resin layer;

and forming a 2 nd resin layer on the conductive layer.

Effects of the invention

According to the present invention, a laminate having excellent bending resistance and a method for producing the same can be provided; and a touch panel having the laminate.

Drawings

Fig. 1 is a sectional view schematically showing a laminate according to an embodiment of the present invention.

Fig. 2 is a sectional view schematically showing a laminate according to an embodiment of the present invention.

Detailed Description

The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples described below, and may be modified and implemented arbitrarily without departing from the scope and range of equivalents of the claims of the present invention.

[1. contents of laminate ]

Fig. 1 and 2 are sectional views schematically showing a laminate 10 according to an embodiment of the present invention.

As shown in fig. 1, a laminate 10 according to one embodiment of the present invention includes a 1 st resin layer 110 made of a resin a, a conductive layer 120, and a 2 nd resin layer 130 made of a resin B in this order in a thickness direction. Further, each of the resin A and the resin B has a storage modulus in a predetermined range at 25 ℃.

Such a laminate 10 is excellent in bending resistance. Here, the bending resistance of the laminate 10 means the following properties: even if the laminate 10 is repeatedly subjected to a bending operation, appearance changes such as cracking and whitening of the conductive layer 120 are less likely to occur. Therefore, even when the folding operation is repeated, the laminate 10 can suppress whitening at the folded portion and the occurrence of cracks in the conductive layer. In particular, as shown in fig. 2, the laminate 10 has high resistance to bending with the surface 110D on the 1 st resin layer 110 side as the outer side and the surface 130U on the 2 nd resin layer 130 side as the inner side.

In addition, in the laminate 10 having the 1 st resin layer 110 and the 2 nd resin layer 130 as the resin layers on both sides of the conductive layer 120, curling due to a difference in thermal shrinkage of each layer is small as compared with a laminate having a resin layer only on one side of the conductive layer. Therefore, the laminate 10 can generally suppress curling due to heat.

The laminate 10 may have any layer other than the 1 st resin layer 110, the conductive layer 120, and the 2 nd resin layer 130. However, the 1 st resin layer 110 and the conductive layer 120 are preferably in direct contact. Also, the conductive layer 120 is preferably in direct contact with the 2 nd resin layer 130. Herein, the manner in which certain two layers are in contact is "direct" meaning that there is no other layer between the two layers. Further, the laminate 10 is particularly preferably a 3-layer film having only the 1 st resin layer 110, the conductive layer 120, and the 2 nd resin layer 130.

[2. the 1 st resin layer ]

The 1 st resin layer is a resin layer formed of a resin a having a storage modulus in a prescribed range at 25 ℃. The specific storage modulus of the resin a contained in the 1 st resin layer at 25 ℃ is usually 500MPa or more, preferably 800MPa or more, particularly preferably 1100MPa or more, usually 20000MPa or less, preferably 18000MPa or less, particularly preferably 16000MPa or less.

By forming the conductive layer between the 1 st resin layer formed of the resin a having the storage modulus in the above range and the 2 nd resin layer formed of the resin B having the storage modulus in the predetermined range, cracking of the conductive layer due to bending can be suppressed. Further, the resin a is less likely to cause whitening due to warping. Therefore, the bending resistance of the laminate can be improved. In particular, when the storage modulus of the resin a is not less than the lower limit of the above range, the heat-resistant dimensional stability can be improved. Further, when the storage modulus of the resin a is not more than the upper limit of the above range, the internal residual stress can be reduced.

The storage modulus of the resin can be measured at a frequency of 1Hz using a dynamic viscoelasticity measuring apparatus. The specific measurement conditions used in the following examples can be employed.

As the resin a, a resin containing a polymer and further optionally containing an optional component can be used. The polymer can be used alone in 1, also can be used in any ratio of 2 or more. The polymer contained in the resin a is preferably a resin containing a polymer having an alicyclic structure. Hereinafter, the alicyclic structure-containing polymer may be referred to as "alicyclic structure-containing polymer" as appropriate.

Since the alicyclic structure-containing polymer is excellent in mechanical strength, the bending resistance of the laminate can be effectively improved. In addition, the alicyclic structure-containing polymer generally has excellent transparency, low water absorption, moisture resistance, dimensional stability and lightweight property.

The alicyclic structure-containing polymer is a polymer having an alicyclic structure in a repeating unit, and examples thereof include a polymer obtainable by a polymerization reaction using a cyclic olefin as a monomer, and a hydrogenated product thereof. Further, as the alicyclic structure-containing polymer, any of a polymer having an alicyclic structure in the main chain and a polymer having 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. Examples of the alicyclic structure include 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 included in 1 alicyclic structure is preferably 4 or more, more preferably 5 or more, still more preferably 6 or more, preferably 30 or less, still more preferably 20 or less, and particularly preferably 15 or less. When the number of carbon atoms included in 1 alicyclic structure is within the above range, mechanical strength, heat resistance, and moldability can be highly balanced.

The proportion of the repeating unit 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 or more. By increasing the proportion of the repeating unit having an alicyclic structure as described above, heat resistance can be improved.

In addition, in the alicyclic structure-containing polymer, the remaining portion other than the repeating unit having an alicyclic structure is not particularly limited and can be appropriately selected depending on the purpose of use.

As the alicyclic structure-containing polymer, either a polymer having crystallinity or a polymer having no crystallinity may be used, or both of them may be used in combination. Here, the polymer having crystallinity means a polymer having a melting point Mp. The polymer having a melting point Mp is a polymer that can be observed by a Differential Scanning Calorimeter (DSC). By using the alicyclic structure-containing polymer having crystallinity, the mechanical strength of the laminate can be particularly effectively improved, and therefore the bending resistance can be remarkably improved. Further, by using the alicyclic structure-containing polymer having no crystallinity, the production cost of the laminate can be reduced.

Examples of the alicyclic structure-containing polymer having crystallinity include the following polymers (. alpha.) to polymers (). Among these, the polymer (. beta.) having a crystalline alicyclic structure is preferable because a laminate having excellent heat resistance can be easily obtained.

Polymer (α): a ring-opened polymer of a cyclic olefin monomer having crystallinity.

Polymer (β): a hydride of the polymer (. alpha.) having crystallinity.

Polymer (γ): addition polymers of cyclic olefin monomers having crystallinity.

Polymer (): a hydride of the polymer (γ) having crystallinity.

Specifically, the alicyclic structure-containing polymer having crystallinity is more preferably a ring-opened polymer of dicyclopentadiene having crystallinity and a hydrogenated product of the ring-opened polymer of dicyclopentadiene having crystallinity, and particularly preferably a hydrogenated product of the ring-opened polymer of dicyclopentadiene having crystallinity. The ring-opened polymer of dicyclopentadiene is a polymer in which the proportion of the constituent unit derived from dicyclopentadiene is usually 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more, and still more preferably 100% by weight based on the total constituent units.

The alicyclic structure-containing polymer having crystallinity may not be crystallized before the production of the laminate. However, after the laminate is produced, the alicyclic structure-containing polymer having crystallinity contained in the laminate can usually have a high degree of crystallinity by crystallization. The specific range of the crystallinity can be appropriately selected depending on the desired performance, and is preferably 10% or more, and more preferably 15% or more. When the degree of crystallization of the alicyclic structure-containing polymer contained in the laminate is not less than the lower limit of the above range, the laminate can be provided with high heat resistance and chemical resistance. The crystallinity can be measured by X-ray diffraction.

The melting point Mp of the alicyclic structure-containing polymer having crystallinity is preferably 200 ℃ or higher, more preferably 230 ℃ or higher, and preferably 290 ℃ or lower. By using the alicyclic structure-containing polymer having crystallinity and having such a melting point Mp, a laminate having a further excellent balance between moldability and heat resistance can be obtained.

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

On the other hand, examples of the alicyclic structure-containing polymer having no crystallinity include: (1) norbornene-based polymers, (2) monocyclic cyclic olefin polymers, (3) cyclic conjugated diene polymers, (4) vinyl alicyclic hydrocarbon polymers, and hydrogenated products thereof. Among these, norbornene polymers and hydrogenated products thereof are more preferable from the viewpoint of transparency and moldability.

Examples of the norbornene-based polymer include: a ring-opening polymer of a norbornene monomer, a ring-opening copolymer of a norbornene monomer and another monomer capable of ring-opening copolymerization, and a hydrogenated product thereof; addition polymers of norbornene monomers, addition copolymers of norbornene monomers and other copolymerizable monomers, and the like. Among these, the hydrogenated ring-opening polymers of norbornene monomers are particularly preferred from the viewpoint of transparency.

The above-mentioned alicyclic structure-containing polymer may be selected from, for example, the polymers disclosed in Japanese patent laid-open publication No. 2002-321302.

Since there are various commercially available products as the resin containing the alicyclic structure-containing polymer having no crystallinity, a resin having desired characteristics can be appropriately selected from these and used. Examples of such commercially available products include products having trade names of "ZEONOR" (manufactured by JAPONIC corporation), "ARTON" (manufactured by JSR corporation), "APEL" (manufactured by Mitsui chemical corporation), and "TOPAS" (manufactured by POLY PLASTIC CORPORATION).

The weight average molecular weight (Mw) of the polymer contained in the resin a is preferably 10000 or more, more preferably 15000 or more, particularly preferably 20000 or more, preferably 100000 or less, more preferably 80000 or less, and particularly preferably 50000 or less. The polymer having such a weight average molecular weight is excellent in balance among mechanical strength, moldability and heat resistance.

The molecular weight distribution (Mw/Mn) of the polymer contained in the 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, more preferably 3.4 or less, and particularly preferably 3.3 or less. When the molecular weight distribution is not less than the lower limit of the above range, the productivity of the polymer can be improved and the production cost can be suppressed. Further, by setting the molecular weight distribution to be equal to or less than the upper limit value, the amount of the low-molecular component is reduced, so that relaxation at the time of high-temperature exposure can be suppressed, and the stability of the laminate can be improved.

The weight average molecular weight Mw and the number average molecular weight Mn of the polymer can be measured as values in terms of polyisoprene by gel permeation chromatography (hereinafter, abbreviated as "GPC") using cyclohexane as a solvent. In the case where the resin is insoluble in cyclohexane, toluene can be used as the solvent. When the solvent is toluene, the weight average molecular weight Mw and the number average molecular weight Mn can be measured as values in terms of polystyrene.

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

The resin a may contain any component in combination with the polymer. Examples of the 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; colorants such as dyes and pigments; and an antistatic agent. These optional components may be used alone in 1 kind, or may be used in combination in an optional ratio of 2 or more kinds. However, from the viewpoint of remarkably exerting the effect of the present invention, it is preferable that the content ratio of any component is small.

The glass transition temperature Tg of the resin A is preferably 130 ℃ or higher, more preferably 140 ℃ or higher, and still more preferably 150 ℃ or higher. By providing the resin a with the glass transition temperature Tg as high as described above, the heat resistance of the resin a can be improved, and therefore, the dimensional change of the 1 st resin layer in a high-temperature environment can be suppressed. Since there is a method of forming a conductive layer under a high-temperature environment such as a vapor deposition method or a sputtering method, the conductive layer can be formed appropriately by providing resin a with excellent heat resistance as described above. In particular, when a conductive layer having a fine pattern shape is to be formed, it is useful that the resin a has excellent heat resistance. From the viewpoint of easily obtaining the resin a, the upper limit of the glass transition temperature of the resin a is preferably 200 ℃ or lower, more preferably 190 ℃ or lower, and particularly preferably 180 ℃ or lower. The glass transition temperature can be measured by the method described in the examples described later.

The 1 st resin layer generally has high transparency. The specific total light transmittance of the 1 st resin layer is preferably 70% or more, more preferably 80% or more, and further preferably 90% or more. The total light transmittance can be measured in the wavelength range of 400nm to 700nm using an ultraviolet-visible spectrophotometer.

The haze of the 1 st resin layer is preferably 5% or less, more preferably 3% or less, particularly preferably 1% or less, ideally 0%. The fog was measured at 5 spots using a haze meter NDH-300A manufactured by Nippon Denshoku industries Co., Ltd according to JIS K7361-1997, and the average value thus obtained was used.

The thickness of the 1 st resin layer is preferably 1 μm or more, more preferably 10 μm or more, particularly preferably 13 μm or more, preferably 100 μm or less, more preferably 80 μm or less, and particularly preferably 60 μm or less. When the thickness of the 1 st resin layer is not less than the lower limit of the above range, the 1 st resin layer can suppress the penetration of moisture into the conductive layer. Therefore, deterioration of the conductive layer due to moisture can be effectively suppressed. On the other hand, by setting the thickness of the 1 st resin layer to be equal to or less than the upper limit of the above range, stress due to bending can be reduced, and therefore the bending resistance of the laminate can be effectively improved.

The method for producing the 1 st resin layer is not limited. Examples of the method for producing the 1 st resin layer include a melt molding method and a solution casting method. Among them, the melt molding method is preferable from the viewpoint of suppressing the residual of volatile components such as a solvent in the 1 st 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, in order to obtain the 1 st resin layer excellent in mechanical strength and surface accuracy, an extrusion molding method, an inflation molding method, and a press molding method are preferable, and an extrusion molding method is particularly preferable from the viewpoint of enabling the 1 st resin layer to be produced efficiently and easily.

[3. conductive layer ]

The conductive layer generally contains a material having conductivity (hereinafter sometimes referred to as "conductive material" as appropriate). Examples of such a conductive material include a metal, a conductive metal oxide, a conductive nanowire, and a conductive polymer. Further, 1 kind of the conductive material may be used alone, or 2 or more kinds may be used in combination at an arbitrary ratio. Among them, from the viewpoint of improving the bending resistance of the laminate, the conductive layer preferably contains at least 1 conductive material selected from a metal, a conductive nanowire, and a conductive polymer.

Examples of the metal include gold, platinum, silver, and copper. Among them, silver, copper and gold are preferable, and silver is more preferable. These metals may be used alone in 1 kind, or may be used in combination in 2 or more kinds at an arbitrary ratio. When the conductive layer is formed using these metals, a transparent conductive layer can be obtained by forming the conductive layer into a thin wire shape. For example, a transparent conductive layer can be obtained by forming a conductive layer as a lattice-shaped metal mesh layer.

The metal-containing conductive layer can be formed by, for example, a method of forming by applying a composition for forming a conductive layer containing metal particles. In this case, the conductive layer forming composition can be printed in a predetermined lattice pattern to obtain a conductive layer as a metal mesh layer. Further, for example, a conductive layer as a metal mesh layer can be formed by applying a composition for forming a conductive layer containing a silver salt and forming fine metal wires into a predetermined lattice pattern by exposure treatment and development treatment. For details of such a conductive layer and a method for forming the same, reference can be made to japanese patent laid-open nos. 2012 and 18634 and 2003 and 331654.

Examples of the conductive metal oxide include ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), IWO (indium tungsten oxide), ITiO (indium titanium oxide), 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. The conductive metal oxide can be used alone in 1 kind, also can be used in any ratio of combination using 2 or more.

The conductive layer containing a conductive metal oxide can be formed by a formation method including a film formation method such as 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 gold plating method, or a combination thereof. Among these, vapor deposition and sputtering are preferable, and sputtering is particularly preferable. Since the conductive layer can be formed to have a uniform thickness by the sputtering method, the occurrence of a locally thin portion in the conductive layer can be suppressed.

The conductive nanowire is a conductive material having a needle-like or wire-like shape and a diameter of nanometer size. The conductive nanowire may be linear or curved. Such conductive nanowires are formed in a mesh shape by forming gaps between the conductive nanowires, and thus a good conductive path can be formed even with a small amount of conductive nanowires, and a conductive layer with low resistance can be realized. Further, since the conductive wire is formed in a mesh shape and the opening is formed in a gap between the meshes, a conductive layer having high light transmittance can be obtained.

The ratio of the thickness d to the length L (aspect ratio: L/d) of the conductive nanowire is preferably 10 to 100000, more preferably 50 to 100000, and particularly preferably 100 to 10000. When such a conductive nanowire having a large aspect ratio is used, the conductive nanowires cross well, and high conductivity can be exhibited by a small amount of the conductive nanowires. As a result, a laminate having excellent transparency can be obtained. Here, the "thickness of the conductive nanowire" means a diameter of the conductive nanowire when the cross section of the conductive nanowire is circular, a minor diameter of the conductive nanowire when the cross section of the conductive nanowire is elliptical, and a longest diagonal line of the conductive nanowire when the cross section of the conductive nanowire is polygonal. The thickness and length of the conductive nanowire can be measured by a scanning electron microscope or a transmission electron microscope.

The thickness of the conductive nanowire is preferably less than 500nm, more preferably less than 200nm, still more preferably 10nm to 100nm, and particularly preferably 10nm to 50 nm. This can improve the transparency of the conductive layer.

The length of the conductive nanowire is preferably 2.5 to 1000. mu.m, more preferably 10 to 500. mu.m, and particularly preferably 20 to 100. mu.m. This can improve the conductivity of the conductive layer.

Examples of the conductive nanowire include a metal nanowire made of a metal, a conductive nanowire including a carbon nanotube, and the like.

As the metal contained in the metal nanowire, a metal having high conductivity is preferable. Preferred examples of the metal include gold, platinum, silver, and copper, and among them, silver, copper, and gold are preferred, and silver is more preferred. Further, a material obtained by subjecting the metal to plating treatment (e.g., gold plating treatment) may be used. Further, the above-mentioned materials may be used alone in 1 kind, or may be used in combination in 2 or more kinds at an arbitrary ratio.

As the method for producing the metal nanowire, any appropriate method can be adopted. Examples thereof include: a method of reducing silver nitrate in solution; and a method of applying a voltage or a current to the surface of the precursor from the tip of the probe, and extracting the metal nanowire from the tip of the probe to continuously form the metal nanowire. In the method of reducing silver nitrate in a solution, silver nanowires can be synthesized by reducing a silver salt such as silver nitrate in a liquid phase in the presence of a polyol such as ethylene glycol and polyvinylpyrrolidone. Silver nanowires of uniform size can be mass-produced according to the methods described in Xia, Y.et., chem.Mater. (2002), 14, 4736-.

Examples of the carbon nanotubes include so-called multi-wall carbon nanotubes, double-wall carbon nanotubes, and single-wall carbon nanotubes having a diameter of 0.3 to 100nm and a length of about 0.1 to 20 μm. Among them, from the viewpoint of high conductivity, single-layer or double-layer carbon nanotubes having a diameter of 10nm or less and a length of 1 to 10 μm are preferable. In addition, the aggregate of carbon nanotubes preferably does not contain impurities such as amorphous carbon and catalytic metal. As the method for producing the carbon nanotube, any appropriate method can be adopted. Carbon nanotubes produced by arc discharge are preferably used. Carbon nanotubes produced by the arc discharge method are preferable because they have excellent crystallinity.

The conductive layer including the conductive nanowire can be formed by a forming method including, for example, the following steps: the conductive nanowire is dispersed in a solvent to obtain a conductive nanowire dispersion, and the conductive nanowire dispersion is coated and dried.

Examples of the solvent contained in the conductive nanodispersion include water, an alcohol-based solvent, a ketone-based solvent, an ether-based solvent, a hydrocarbon-based solvent, an aromatic solvent, and the like, and among them, water is preferably used from the viewpoint of reducing environmental load. Further, 1 kind of solvent may be used alone, or 2 or more kinds may be used in combination at an arbitrary ratio.

The concentration of the conductive nanowires in the conductive nanowire dispersion liquid is preferably 0.1 to 1 wt%. This enables formation of a conductive layer having excellent conductivity and transparency.

The conductive nanowire dispersion can contain any component in combination with the conductive nanowires and the solvent. Examples of the optional component include a corrosion inhibitor for inhibiting corrosion of the conductive nanowire, a surfactant for inhibiting aggregation of the conductive nanowire, a binder polymer for holding the conductive nanowire in the conductive layer, and the like. In addition, any of the components can be used alone in 1, also can be used in any ratio of 2 or more.

Examples of the method for applying the conductive nanowire dispersion include a spray coating method, a bar coating method, a roll coating method, a die coating method, an inkjet coating method, a screen coating method, a dip coating method, a slot die coating method, a relief printing method, a gravure printing method, and a gravure printing method. As the drying method, any suitable drying method (for example, natural drying, air-blast drying, heat drying) can be adopted. For example, in the case of heat drying, the drying temperature may be 100 to 200 ℃ and the drying time may be 1 to 10 minutes.

The proportion of the conductive nanowires in the conductive layer is preferably 80 to 100 wt%, and more preferably 85 to 99 wt% based on the total weight of the conductive layer. This can provide a conductive layer having excellent electrical conductivity and light transmittance.

Examples of the conductive polymer include polythiophene-based polymer, polyacetylene-based polymer, polyparaphenylene-based polymer, polyaniline-based polymer, polyparaphenylene-vinylene-based polymer, polypyrrole-based polymer, polyphenylene-based polymer, and polyester-based polymer modified with an acrylic polymer. Among them, polythiophene-based polymers, polyacetylene-based polymers, polyparaphenylene-based polymers, polyaniline-based polymers, polyparaphenylene vinylene-based polymers, and polypyrrole-based polymers are preferable.

Among them, polythiophene-based polymers are particularly preferable. By using the polythiophene-based polymer, a conductive layer having excellent transparency and chemical stability can be obtained. Specific examples of the polythiophene-based polymer include: a polythiophene; poly (3-C) such as poly (3-hexylthiophene)_1-8Alkyl-thiophenes); poly (3, 4-ethylidene bisOxythiophene), poly (3, 4-propylenedioxythiophene), poly [3,4- (1, 2-cyclohexylene) dioxythiophene]Poly (3,4- (cyclo) alkylenedioxythiophenes) and the like; polythienylenevinylenes and the like. Here, "C" is_1-8The alkyl group represents an alkyl group having 1 to 8 carbon atoms. The conductive polymer can be used alone in 1 kind, also can be used in any ratio of 2 or more.

The conductive polymer is preferably polymerized in the presence of an anionic polymer. For example, the polythiophene-based polymer is preferably subjected to oxidative polymerization in the presence of an anionic polymer. Examples of the anionic polymer include polymers having a carboxyl group, a sulfonic acid group, or salts thereof. An anionic polymer having a sulfonic acid group such as polystyrenesulfonic acid is preferably used.

The conductive layer containing a conductive polymer can be formed by a forming method including, for example, coating and drying a conductive layer forming composition containing a conductive polymer. As for the conductive layer containing a conductive polymer, japanese patent application laid-open publication No. 2011-175601 can be referred to.

The conductive layer is formed using the conductive material as described above, and therefore has conductivity. The conductivity of the conductive layer can be represented by, for example, a surface resistance value. The specific surface resistance value of the conductive layer can be set according to the use of the laminate. In one embodiment, the surface resistance value of the conductive layer is preferably 1000 Ω/sq or less, more preferably 900 Ω/sq or less, and particularly preferably 800 Ω/sq or less. The lower limit of the surface resistance value of the conductive layer is not particularly limited, but is preferably 1 Ω/sq. or more, more preferably 2.5 Ω/sq. or more, and particularly preferably 5 Ω/sq. or more, from the viewpoint of easy production.

The conductive layer may be formed in the entire region between the 1 st resin layer and the 2 nd resin layer, or may be formed in a partial region. For example, the conductive layer may be formed by patterning the conductive layer in a pattern having a predetermined planar shape. Here, the planar shape refers to a shape when viewed in 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, in the case where the laminate is used as a circuit substrate, the planar shape of the conductive layer may be patterned to correspond to the wiring shape of the circuit. In addition, for example, when the laminate is used as a touch panel sensor film, the planar shape of the conductive layer is preferably a pattern that works well as a touch panel (for example, a capacitive touch panel), and specific examples thereof include patterns described in japanese patent publication No. 2011-511357, japanese patent publication No. 2010-164938, japanese patent publication No. 2008-310550, japanese patent publication No. 2003-511799, and japanese patent publication No. 2010-541109.

The conductive layer generally has high transparency. Thus, visible light is generally able to transmit through the conductive layer. The specific transparency of the conductive layer can be adjusted according to the use of the laminate. The specific total light transmittance of the conductive layer is preferably 80% or more, more preferably 90% or more, and further preferably 95% or more.

The thickness of the conductive layer per 1 layer is preferably 0.010 μm or more, more preferably 0.020 μm or more, particularly preferably 0.025 μm or more, preferably 10 μm or less, more preferably 3 μm or less, and particularly preferably 1 μm or less. This can improve the transparency of the conductive layer.

[4. 2 nd resin layer ]

The 2 nd resin layer is a resin layer formed of a resin B having a storage modulus in a prescribed range at 25 ℃. The specific storage modulus of the resin B contained in the 2 nd resin layer at 25 ℃ is usually 10MPa or more, preferably 15MPa or more, particularly preferably 30MPa or more, usually 1000MPa or less, preferably 950MPa or less, particularly preferably 900MPa or less.

By forming the conductive layer between the 2 nd resin layer formed of the resin B having the storage modulus in the above range and the 1 st resin layer formed of the resin a, the bending resistance of the laminate can be improved. In particular, by setting the storage modulus of the resin B to the lower limit value or more of the above range, the heat resistance can be improved. In addition, the bending resistance can be improved by setting the storage modulus of the resin B to the upper limit value or less of the above range.

In the combination of the 1 st resin layer and the 2 nd resin layer described above, the storage modulus of the resin B contained in the 2 nd resin layer is generally smaller than the storage modulus of the resin a contained in the 1 st resin layer. Therefore, the flexibility of the 2 nd resin layer is superior to the flexibility of the 1 st resin layer, and therefore the 2 nd resin layer is superior in resistance to deformation. Therefore, the laminate can usually exhibit particularly high bending resistance against bending in a direction in which the surface on the 1 st resin layer side is the outer side and the surface on the 2 nd resin layer side is the inner side.

As the resin B, a resin containing a polymer and further optionally containing an optional component can be used. The polymer can be used alone in 1, also can be used in any ratio of 2 or more. As the polymer contained in the resin B, a block copolymer hydride is preferable. The block copolymer hydride is a hydrogenated block copolymer. In the following description, the above-mentioned block copolymer may be referred to as "block copolymer [1 ]" as appropriate. In the following description, the hydrogenated product of the block copolymer [1] may be referred to as "hydrogenated product [2 ].

The block copolymer [1] preferably comprises a polymer block [ a ] containing an aromatic vinyl compound unit and a polymer block [ B ] containing a chain conjugated diene compound unit (a linear conjugated diene compound unit, a branched conjugated diene compound unit, etc.). Among the block copolymers [1], particularly preferred are: the block copolymer [1] has 2 or more polymer blocks [ A ] per 1 molecule, and the block copolymer [1] has 1 or more polymer blocks [ B ].

The polymer block [ A ] is a polymer block containing an aromatic vinyl compound unit. The aromatic vinyl compound unit herein means a structural unit having a structure obtained 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; styrenes having an alkyl group having 1 to 6 carbon atoms as a substituent, such as α -methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2, 4-dimethylstyrene, 2, 4-diisopropylstyrene, 4-tert-butylstyrene, and 5-tert-butyl-2-methylstyrene; styrenes having a halogen atom as a substituent, such as 4-chlorostyrene, dichlorostyrene, and 4-monofluorostyrene; styrenes having an alkoxy group having 1 to 6 carbon atoms as a substituent, such as 4-methoxystyrene; styrenes having an aryl group as a substituent, such as 4-phenylstyrene; and vinylnaphthalenes such as 1-vinylnaphthalene and 2-vinylnaphthalene. These may be used alone in 1 kind, or may be used in combination in an arbitrary ratio in 2 or more kinds. Among these, styrene having an alkyl group having 1 to 6 carbon atoms as a substituent, and other aromatic vinyl compounds not having a polar group are preferable from the viewpoint of reducing the hygroscopicity, and styrene is particularly preferable from the viewpoint of being industrially easily available.

The content of the aromatic vinyl compound unit in the 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 2 nd resin layer can be improved.

The polymer block [ A ] may contain an arbitrary structural unit in addition to the aromatic vinyl compound unit. The polymer block [ A ] may contain 1 arbitrary structural unit alone, or may contain 2 or more arbitrary structural units in combination at an arbitrary ratio.

Examples of the optional structural unit that can be contained in the polymer block [ a ] include a chain conjugated diene compound unit. Here, the chain conjugated diene compound unit means a structural unit having a structure obtained 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 ones as those exemplified as the chain conjugated diene compound corresponding to the chain conjugated diene compound unit contained in the polymer block [ B ].

Examples of the optional structural unit that can be contained in the polymer block [ a ] include a structural unit having a structure obtained by polymerizing an optional unsaturated compound other than the aromatic vinyl compound and the chain-like conjugated diene compound. Examples of the optional unsaturated compound include: vinyl compounds such as chain 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, a linear olefin having 2 to 20 carbon atoms per 1 molecule, such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-eicosene, 4-methyl-1-pentene, 4, 6-dimethyl-1-heptene, is preferable; a vinyl compound having no polar group such as a cyclic olefin having 5 to 20 carbon atoms per 1 molecule, such as vinylcyclohexene, more preferably a chain olefin having 2 to 20 carbon atoms per 1 molecule, and particularly preferably ethylene or propylene.

The content of any structural unit in the 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 the polymer blocks [ A ] in the 1-molecule block copolymer [1] is preferably 2 or more, preferably 5 or less, more preferably 4 or less, and particularly preferably 3 or less. The plural polymer blocks [ A ] in the molecule 1 may be the same as or different from each other.

The polymer block [ B ] is a polymer block containing a chain-like conjugated diene compound unit. As described above, the chain conjugated diene compound unit means a structural unit having a structure obtained by polymerizing a chain conjugated diene compound.

Examples of the chain conjugated diene compound corresponding to the chain conjugated diene compound unit contained in the polymer block [ B ] include straight chain conjugated diene compounds and branched chain conjugated diene compounds. Specific examples of the chain conjugated diene compound include 1, 3-butadiene, isoprene, 2, 3-dimethyl-1, 3-butadiene, 1, 3-pentadiene, and the like. These may be used alone in 1 kind, or may be used in combination in an arbitrary ratio in 2 or more kinds. Among these, chain-like conjugated diene compounds containing no polar group are preferable from the viewpoint of reducing the hygroscopicity, and 1, 3-butadiene and isoprene are particularly preferable.

The content of the chain conjugated diene compound unit in the 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 making the amount of the chain conjugated diene compound units in the polymer block [ B ] as large as described above, the flexibility of the 2 nd resin layer can be improved.

The polymer block [ B ] may contain an arbitrary structural unit in addition to the chain conjugated diene compound unit. The polymer block [ B ] may contain 1 arbitrary structural unit alone, or may contain 2 or more arbitrary structural units in combination at an arbitrary ratio.

Examples of the optional structural unit that can be contained in the polymer block [ B ] include an aromatic vinyl compound unit and a structural unit having a structure obtained by polymerizing an optional unsaturated compound other than an aromatic vinyl compound and a chain-like conjugated diene compound. Examples of the aromatic vinyl compound unit and the structural unit having a structure obtained by polymerizing an arbitrary unsaturated compound include the same structural units as those exemplified as the structural units that can be contained in the polymer block [ a ].

The content of any structural unit in the 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. By reducing the content of an arbitrary structural unit in the polymer block [ B ], the flexibility of the 2 nd resin layer can be improved.

The number of the polymer blocks [ B ] in the 1-molecule block copolymer [1] is usually not less than 1, and may be not less than 2. When the number of the polymer blocks [ B ] in the block copolymer [1] is 2 or more, these polymer blocks [ B ] may be the same as or different from each other.

The block form of the block copolymer [1] may be a chain-type block or a radial-type block. Among them, the chain-type block is preferable because it is excellent in mechanical strength. In the case where the block copolymer [1] has a chain-type block form, the viscosity of the 2 nd resin layer can be suppressed to a desired low value by making both ends of the molecular chain of the block copolymer [1] be the polymer blocks [ a ].

Particularly preferred block forms of the block copolymer [1] are: a triblock copolymer in which the polymer block [ A ] is bonded to both ends of the polymer block [ B ] as represented by [ A ] to [ B ] to [ A ]; as shown in [ A ] - [ B ] - [ A ] - [ B ] - [ A ], a pentablock copolymer in which the polymer block [ B ] is bonded to both ends of the polymer block [ A ] and the polymer block [ A ] is further bonded to the other ends of the two polymer blocks [ B ], respectively. In particular, the triblock copolymers [ A ] - [ B ] - [ A ] are particularly preferable because they can be easily produced and the physical properties can be easily controlled within a desired range.

In the block copolymer [1], the ratio (wA/wB) of the weight fraction wA of the polymer block [ A ] in the whole block copolymer [1] to the weight fraction wB of the polymer block [ B ] in the whole block copolymer [1] is preferably in 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, preferably 85/15 or less, more preferably 70/30 or less, and particularly preferably 55/45 or less. When the ratio wA/wB is not less than the lower limit of the above range, the rigidity and heat resistance of the 2 nd resin film can be improved, and birefringence can be reduced. When the ratio wA/wB is equal to or less than the upper limit of the above range, the flexibility of the 2 nd resin layer can be improved. Here, the weight fraction wA of the polymer block [ A ] represents the weight fraction of the whole of the polymer block [ A ], and the weight fraction wB of the polymer block [ B ] represents the weight fraction of the whole of the polymer block [ B ].

The weight average molecular weight (Mw) of the block copolymer [1] is preferably 30000 or more, more preferably 40000 or more, particularly preferably 50000 or more, preferably 200000 or less, more preferably 150000 or less, particularly preferably 100000 or less.

The molecular weight distribution (Mw/Mn) of the 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 the molecular weight distribution (Mw/Mn) of the block copolymer [1] can be measured as values in terms of polystyrene by Gel Permeation Chromatography (GPC) using Tetrahydrofuran (THF) as a solvent.

As the method for producing the block copolymer [1], for example, the method described in International publication No. 2015/099079 and Japanese patent application laid-open No. 2016-204217 can be used.

The hydride [2] is a polymer obtained by hydrogenating the unsaturated bond of the block copolymer [1 ]. Here, both of the aromatic and nonaromatic carbon-carbon unsaturated bonds in the main chain and side chain of the block copolymer [1] are contained in the unsaturated bond of the hydrogenated block copolymer [1 ].

Hydride [2]]The hydrogenation ratio (c) is preferably 90% or more, more preferably 97% or more, and still more preferably 99% or more. Hydrides [2] unless otherwise stated]The hydrogenation ratio of (2) is in the block copolymer [1]]The ratio of the bond to be hydrogenated in the aromatic and non-aromatic carbon-carbon unsaturated bonds in the main chain and the side chain of (2). The higher the hydrogenation ratio, the better the transparency, heat resistance and weather resistance of the 2 nd resin layer can be made, and the more easily the birefringence of the 2 nd resin layer can be reduced. Here, the hydride [2]]Can be obtained by using¹H-NMR was measured.

In particular, the hydrogenation rate of the nonaromatic carbon-carbon unsaturated bond is preferably 95% or more, and more preferably 99% or more. By increasing the hydrogenation rate of the nonaromatic carbon-carbon unsaturated bond, the light resistance and oxidation resistance of the 2 nd resin layer can be further improved.

The hydrogenation ratio of the aromatic carbon-carbon unsaturated bond is preferably 90% or more, more preferably 93% or more, and particularly preferably 95% or more. By increasing the hydrogenation rate of aromatic carbon-carbon unsaturated bonds, the glass transition temperature of the polymer block obtained by hydrogenating the polymer block [ A ] is increased, and therefore, the heat resistance of the 2 nd resin layer can be effectively improved. Further, the photoelastic coefficient of the resin B can be reduced.

The weight average molecular weight (Mw) of the hydride [2] is preferably 30000 or more, more preferably 40000 or more, further preferably 45000 or more, preferably 200000 or less, more preferably 150000 or less, further preferably 100000 or less. By setting the weight average molecular weight (Mw) of the hydride [2] within the above range, the mechanical strength and heat resistance of the 2 nd resin layer can be improved, and the birefringence of the 2 nd resin layer can be easily reduced.

The molecular weight distribution (Mw/Mn) of the 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 setting the molecular weight distribution (Mw/Mn) of the hydride [2] within the above range, the mechanical strength and heat resistance of the 2 nd resin layer can be improved, and the birefringence of the 2 nd resin layer can be easily reduced.

The weight average molecular weight (Mw) and the molecular weight distribution (Mw/Mn) of the hydride [2] can be measured as values in terms of polystyrene by Gel Permeation Chromatography (GPC) using Tetrahydrofuran (THF) as a solvent.

The above-mentioned hydride [2] can be produced by hydrogenating the block copolymer [1 ]. As the hydrogenation method, a hydrogenation method which can increase the hydrogenation rate and which causes less chain scission reaction of the block copolymer [1] is preferable. Examples of such hydrogenation methods include the methods described in International publication No. 2015/099079 and Japanese patent application laid-open No. 2016 and 204217.

In the hydride [2] contained in the resin B, an alkoxysilyl group may be introduced. Hereinafter, the hydride [2] into which an alkoxysilyl group has been particularly introduced may be referred to as "alkoxysilyl-modified product [3 ]. The introduction of the alkoxysilyl group makes the alkoxysilyl-modified product [3] exhibit high adhesion to other materials. Therefore, the 2 nd resin layer formed of the resin B containing the alkoxysilyl-modified product [3] has excellent adhesion to the conductive layer, and therefore the mechanical strength of the entire laminate can be improved. Therefore, the use of the alkoxysilyl group-modified product [3] can improve the bending resistance in particular.

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

The amount of the alkoxysilyl group introduced into the alkoxysilyl-modified product [3] is preferably 0.1 part by weight or more, more preferably 0.2 part by weight or more, particularly preferably 0.3 part 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, based on 100 parts by weight of the hydride [2] before introduction of the alkoxysilyl group. When the amount of the introduced alkoxysilyl group is controlled within the above range, the degree of crosslinking between alkoxysilyl groups decomposed by moisture or the like can be suppressed from excessively increasing, and therefore, the adhesion of the 2 nd resin layer can be maintained high.

The amount of the alkoxysilyl group introduced can be used¹H-NMR spectrum was measured. In addition, when the introduced amount of the alkoxysilyl group is measured, the number of times of integration can be increased when the introduced amount is small.

The weight average molecular weight (Mw) of the alkoxysilyl-modified product [3] is generally not much changed from the weight average molecular weight (Mw) of the hydride [2] before introduction of the alkoxysilyl group because the amount of the alkoxysilyl group introduced is small. However, when the alkoxysilyl group is introduced, the hydride [2] is generally subjected to a modification reaction in the presence of a peroxide, and therefore the hydride [2] tends to undergo a crosslinking reaction and a chain scission reaction, and the molecular weight distribution tends to change greatly. The weight average molecular weight (Mw) of the alkoxysilyl-modified product [3] is preferably 30000 or more, more preferably 40000 or more, still more preferably 45000 or more, preferably 200000 or less, more preferably 150000 or less, and particularly preferably 100000 or less. The molecular weight distribution (Mw/Mn) of the alkoxysilyl-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 or more. When the weight average molecular weight (Mw) and the molecular weight distribution (Mw/Mn) of the alkoxysilyl-modified product [3] are within these ranges, good mechanical strength and tensile elongation of the 2 nd resin layer can be maintained.

The weight average molecular weight (Mw) and the molecular weight distribution (Mw/Mn) of the alkoxysilyl-modified product [3] can be measured as polystyrene converted values by Gel Permeation Chromatography (GPC) using tetrahydrofuran as a solvent.

The alkoxysilyl-modified product [3] can be produced by introducing an alkoxysilyl group into the hydride [2] of the block copolymer [1 ]. Examples of the method for introducing an alkoxysilyl group into the hydride [2] include the methods described in International publication No. 2015/099079 and Japanese patent application laid-open No. 2016-204217.

The proportion of the polymer such as the hydride [2] (including the alkoxysilyl-modified product [3]) in the resin B is preferably 80 to 100% by weight, more preferably 90 to 100% by weight, and particularly preferably 95 to 100% by weight. By setting the ratio of the polymer in the resin B to the above range, the storage modulus of the resin B can be easily controlled to the above range.

The resin B may contain any component in combination with the above polymer. Examples of the optional component include the same components as those that can be contained in the resin a. In addition, any of the components can be used alone in 1, also can be used in any ratio of 2 or more.

The 2 nd resin layer generally has high transparency. The specific total light transmittance of the 2 nd resin layer is preferably 70% or more, more preferably 80% or more, and further preferably 90% or more. The haze of the 2 nd resin layer is preferably 5% or less, more preferably 3% or less, particularly preferably 1% or less, and ideally 0%.

The thickness of the 2 nd resin layer is preferably 1 μm or more, more preferably 10 μm or more, particularly preferably 15 μm or more, preferably 100 μm or less, more preferably 80 μm or less, and particularly preferably 60 μm or less. When the thickness of the 2 nd resin layer is not less than the lower limit of the above range, the penetration of moisture into the conductive layer can be suppressed by the 2 nd resin layer. Therefore, deterioration of the conductive layer due to moisture can be effectively suppressed. On the other hand, by setting the thickness of the 2 nd resin layer to be equal to or less than the upper limit of the above range, stress due to bending can be reduced, and therefore the bending resistance of the laminate can be effectively improved.

The method for manufacturing the 2 nd resin layer is not limited. Examples of the method for producing the 2 nd resin layer include a melt molding method and a solution casting method. Among them, the melt molding method is preferable from the viewpoint that the residue of volatile components such as a solvent in the 2 nd resin layer can be suppressed. Further, in order to obtain the 2 nd resin layer excellent in mechanical strength and surface accuracy, among the melt molding methods, an extrusion molding method, an inflation molding method and a press molding method are preferable, and from the viewpoint of enabling the 2 nd resin layer to be produced efficiently and easily, an extrusion molding method is particularly preferable.

[5. optional layers ]

The laminate may further include any layer in combination with the 1 st resin layer, the conductive layer, and the 2 nd resin layer described above, as necessary. For example, the laminate may have any layer at a position such as the 1 st resin layer on the side opposite to the conductive layer and the 2 nd resin layer on the side opposite to the conductive layer. Examples of the optional layer include a support layer, a hard coat layer, a refractive index matching layer, an adhesive layer, a retardation layer, a polarizer layer, and an optical compensation layer.

[6. physical Properties and thickness of laminate ]

The laminate has excellent bending resistance. Therefore, even when the laminate is repeatedly bent, the appearance change such as cracking or whitening of the conductive layer can be suppressed. For example, in one embodiment, even when the folding is repeated 1 ten thousand times in accordance with the folding test described in the example described later, the cracking and the change in the appearance of the conductive layer at the folded portion can be suppressed, and the cracking and the change in the appearance of the conductive layer can be preferably eliminated.

The principle that the laminate can exhibit 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 principle described below.

The resin B included in the 2 nd resin layer has excellent flexibility because it has a storage modulus in an appropriate range. Therefore, when the laminate is bent, the 2 nd resin layer is easily deformed, and can absorb stress caused by bending. Further, since the 1 st resin layer formed of the resin a having an appropriate storage modulus is provided on the opposite side of the conductive layer from the 2 nd resin layer, it is possible to further effectively suppress concentration of a large stress in the conductive layer. Therefore, cracks in the conductive layer due to stress caused by bending can be effectively suppressed.

Further, since the 1 st resin layer and the 2 nd resin layer have storage moduli in an appropriate range, breakage of the 1 st resin layer and the 2 nd resin layer is less likely to occur in the case of bending the laminate. Further, due to the action of an appropriate storage modulus, peeling of the 1 st resin layer and the conductive layer and peeling of the 2 nd resin layer and the conductive layer are less likely to occur. Therefore, since the minute voids due to the breakage or peeling are less likely to be generated, the rise of the fog at the bent portion is less likely to be caused, and thus the change in the appearance such as whitening can be suppressed.

Since the laminate includes the 1 st resin layer and the 2 nd resin layer having flexibility as layers for supporting the conductive layer, the laminate is generally superior in impact resistance and processability as compared with conductive glass. Further, the laminate is generally lighter than the conductive glass.

From the viewpoint of using the laminate as an optical member, the total light transmittance of the laminate is preferably 70% or more, more preferably 80% or more, and further preferably 90% or more.

From the viewpoint of improving the image clarity of the image display device on which the laminate is mounted, the haze of the laminate is preferably 5% or less, more preferably 3% or less, particularly preferably 1% or less, and ideally 0%.

The thickness of the laminate is preferably 2 μm or more, more preferably 5 μm or more, further preferably 7.5 μm or more, particularly preferably 10 μm or more, preferably 200 μm or less, more preferably 175 μm or less, and particularly preferably 150 μm or less. When the thickness of the laminate is not less than the lower limit of the above range, the mechanical strength of the laminate can be improved, and wrinkles can be prevented when the conductive layer is formed. Further, by setting the thickness of the laminate to be equal to or less than the upper limit of the above range, the laminate can be made particularly excellent in bending resistance, and the laminate can be further made thinner.

[7. method for producing laminate ]

The method for producing the laminate is not limited. For example, from the viewpoint of easily producing the laminate, the laminate is preferably produced by a production method including the steps of: preparing a 1 st resin layer; forming a conductive layer on the 1 st resin layer; and a step of forming a 2 nd resin layer on the conductive layer.

In the step of preparing the 1 st resin layer, for example, the 1 st resin layer is formed from the resin a according to the above-described method for producing the 1 st resin layer.

In the step of forming the conductive layer, for example, the conductive layer is formed on the 1 st resin layer according to the above-described method of forming the conductive layer. The conductive layer may be formed on the 1 st resin layer through any interlayer bonding. However, the conductive layer is preferably formed directly on the 1 st resin layer. Here, the manner of forming another layer over a certain layer is "directly" means that there is no other layer between the 2 layers.

In the step of forming the 2 nd resin layer, the 2 nd resin layer is formed on the opposite side of the conductive layer from the 1 st resin layer. The 2 nd resin layer may be formed on the conductive layer through any layer bonding. For example, after the 2 nd resin layer is prepared by the above-described method for producing the 2 nd resin layer, the 2 nd resin layer may be bonded to the conductive layer with an adhesive or bonding agent. However, the 2 nd resin layer is preferably formed directly on the conductive layer. For example, the 2 nd resin layer can be directly formed on the conductive layer by heating the 2 nd resin layer as necessary and pressure-bonding it to the surface of the conductive layer. Further, for example, the 2 nd resin layer can be directly formed on the conductive layer by applying a coating liquid containing the resin B and a solvent to the conductive layer and drying the coating liquid as necessary.

The method for producing a laminate may further include any step in combination with the above steps.

[8. touch Panel ]

The laminate described above can be used for various optical applications. The laminate can be used as a member of a touch panel, for example. The laminate is excellent in bending resistance, and therefore is particularly suitable for a touch panel having flexibility.

In the touch panel having the laminate, the orientation of the laminate is arbitrary. For example, in the touch panel, the 1 st resin layer, the conductive layer, and the 2 nd resin layer may be provided in this order from the viewing side. For example, in the touch panel, the 2 nd resin layer, the conductive layer, and the 1 st resin layer may be provided in this order from the viewing side.

In general, a touch panel is often used in a state where a surface on the viewing side is curved outward. Therefore, the orientation of the laminate provided in the touch panel is preferably set so that a touch panel that can be bent with the viewing-side surface as the outer side can be obtained. As described above, the laminate generally has high resistance to bending with the surface on the 1 st resin layer side as the outer side. Therefore, in order to allow the laminate to be bent with the viewing-side surface of the laminate as the outer side, the laminate is preferably oriented in the order of the 1 st resin layer, the conductive layer, and the 2 nd resin layer from the viewing side. Thus, a touch panel that can be bent with the viewing side surface as the outer side can be obtained.

The touch panel generally has an image display element in combination with a laminate. Examples of the image display element include a liquid crystal display element and an organic electroluminescence display element (hereinafter, may be referred to as an "organic EL display element" as appropriate). In general, the laminate is provided on the viewing side of the image display element.

In order to obtain a touch panel having flexibility, it is preferable to use an image display element having flexibility (flexible display element) as the image display element. Examples of such a flexible image display element include an organic EL display element.

In general, an organic EL display element includes a first electrode layer, a light-emitting layer, and a second electrode layer in this order on a substrate, and can generate light in the light-emitting layer by applying a voltage from the first electrode layer and the second electrode layer. Examples of the material constituting the organic light-emitting layer include materials of a polyparaphenylene vinylene system, a polyfluorene system, and a polyvinyl carbazole system. The light-emitting layer may have a laminate of a plurality of layers having different luminescent colors, or a mixed layer in which a layer of a certain pigment is doped with a different pigment. The organic EL display element may further 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 forming layer, and a charge generation layer.