JPWO2016158578A1 - Transparent conductive sheet, touch panel module and touch panel device - Google Patents

Abstract

To suppress the occurrence of disconnection or short circuit due to migration of the metal material constituting the conductive layer. At least a conductive layer using a metal material as a conductive substance and an adhesive layer in contact with the conductive layer, wherein the adhesive layer is at least selected from the group consisting of a hydroxyl group, an alkoxy group, an amino group, and an amide group An acrylic copolymer having a hydrophilic acrylic monomer containing one kind of hydrophilic group as a copolymerization monomer component, and at least one migration inhibitor selected from the group consisting of a moisture absorbent and a metal ion scavenger; And a transparent conductive sheet in which the blending ratio of the hydrophilic acrylic monomer in the copolymerization monomer component of the acrylic copolymer is 15% by mass or more of the total weight of the acrylic copolymer, and the transparent conductive sheet. Touch panel module and touch panel device.

Description

  The present invention relates to a transparent conductive sheet, a touch panel module, and a touch panel device.

  A display with a touch panel that enables an operation by touching an image display surface is widely used in smartphones, tablet terminals, notebook computers, ticket vending machines, ATMs, and the like. The touch panel has a resistive film type that detects the position of the screen pressed by a finger or pen by measuring the voltage change, and a sensor that detects the weak current generated when you touch the screen with your finger, that is, the change in capacitance (charge). A capacitance method that senses and touches the touched position is known.

  In a capacitive touch panel, a configuration in which an ITO film (indium tin oxide) is provided as a transparent conductive film on a transparent resin film or glass substrate is widely adopted. However, since the ITO film has a large resistance, there is a problem that the response speed (the time from when the fingertip is touched until the position is detected) becomes slow as the screen size increases. For this reason, instead of an electrode made of a transparent metal oxide such as an ITO film, an electrode formed by arranging a large number of grids made of band-shaped conductive regions formed using a metal material such as metal fine particles is adopted. A method for reducing the surface resistance has also been proposed (for example, Patent Document 1).

  In the technique exemplified in Patent Document 1 and the like, due to the miniaturization of the conductive region such as the wiring configuring the conductive layer and the distance between the wirings becoming narrower, by the ionization of the metal material (silver, copper, etc.) configuring the wiring. It is known that disconnection or short circuit due to migration is likely to occur. In order to solve such a problem, a wiring board in which a reducing compound having a redox potential of 0.40 to 1.30 V is contained in a transparent adhesive layer provided in direct contact with a metal wiring containing silver. It has been proposed (Patent Document 2). In this technique, migration of silver ions is suppressed by reducing silver ions to metallic silver by a reducing compound such as a phenol compound, an amine compound, or a sulfur compound.

JP 2012-33147 A JP 2014-82446 A

  The present invention has been made in view of the above circumstances, a transparent conductive sheet capable of suppressing the occurrence of disconnection and short circuit due to migration of the metal material constituting the conductive layer, and a touch panel module manufactured using the same It is an object to provide a touch panel device.

The above-mentioned subject is achieved by the following present invention. That is,
The transparent conductive sheet of the present invention includes at least a conductive layer using a metal material as a conductive substance and an adhesive layer in contact with the conductive layer, and the adhesive layer includes a hydroxyl group, an alkoxy group, an amino group, and an amide group. Selected from the group consisting of an acrylic copolymer having, as a copolymerization monomer component, a hydrophilic acrylic monomer containing at least one hydrophilic group selected from the group consisting of: a water absorbent and a metal ion scavenger And a blending ratio of the hydrophilic acrylic monomer in the copolymer monomer component of the acrylic copolymer is 15% by mass or more of the total weight of the acrylic copolymer. It is characterized by that.

  The touch panel module of the present invention includes at least a conductive layer using a metal material as a conductive substance and an adhesive layer in contact with the conductive layer, and the adhesive layer includes a hydroxyl group, an alkoxy group, an amino group, and an amide group. At least one selected from the group consisting of an acrylic copolymer having, as a copolymerization monomer component, a hydrophilic acrylic monomer containing at least one hydrophilic group selected from the group consisting of: a water absorbent and a metal ion scavenger A blending ratio of the hydrophilic acrylic monomer in the copolymer monomer component of the acrylic copolymer is 15% by mass or more of the total weight of the acrylic copolymer. Features.

  The touch panel device of the present invention includes at least an image display device, a conductive layer using a metal material as a conductive substance, and an adhesive layer that is in contact with the conductive layer, provided on the image display surface side of the image display device. The pressure-sensitive adhesive layer includes an acrylic copolymer having, as a copolymerization monomer component, a hydrophilic acrylic monomer containing at least one hydrophilic group selected from the group consisting of a hydroxyl group, an alkoxy group, an amino group, and an amide group. , At least one migration inhibitor selected from the group consisting of a moisture absorbent and a metal ion scavenger, and the blending ratio of the hydrophilic acrylic monomer in the copolymerizable monomer component of the acrylic copolymer is It is characterized by being 15% by mass or more of the total weight of the acrylic copolymer.

  ADVANTAGE OF THE INVENTION According to this invention, the transparent conductive sheet which can suppress generation | occurrence | production of the disconnection and short circuit resulting from migration of the metal material which comprises a conductive layer, and the touch panel module and touch panel apparatus produced using this can be provided. .

It is a schematic plan view which shows an example of the transparent conductive sheet of this invention. It is a schematic plan view which shows the other example of the transparent conductive sheet of this invention. FIG. 3 is an enlarged plan view showing an example when the conductive region shown in FIGS. 1 and 2 is enlarged. It is a schematic cross section which shows an example of the cross-section of the transparent conductive sheet of this invention. It is a schematic cross section which shows the other example of the cross-section of the transparent conductive sheet of this invention. It is a schematic cross section which shows the other example of the cross-section of the transparent conductive sheet of this invention. It is a schematic cross section which shows the other example of the cross-section of the transparent conductive sheet of this invention. It is a schematic cross section showing an example of the touch panel device of this embodiment.

  The transparent conductive sheet of the present embodiment includes at least a conductive layer using a metal material as a conductive substance and an adhesive layer in contact with the conductive layer. The adhesive layer includes a hydroxyl group, an alkoxy group, an amino group, and an amide. Selected from the group consisting of an acrylic copolymer having a hydrophilic acrylic monomer containing at least one hydrophilic group selected from the group consisting of a group as a copolymerization monomer component, a moisture absorbent and a metal ion scavenger. At least one kind of migration inhibitor, and the blending ratio of the hydrophilic acrylic monomer in the copolymer monomer component of the acrylic copolymer is 15% by mass or more of the total weight of the acrylic copolymer. It is characterized by being.

  In the transparent conductive sheet of this embodiment, the pressure-sensitive adhesive layer includes an acrylic copolymer having a hydrophilic acrylic monomer as a copolymerization monomer component (hereinafter sometimes referred to as “hydrophilic polymer”). Therefore, when moisture enters from the outside, it is strongly attracted to the side of the pressure-sensitive adhesive layer (the hydrophilic polymer) in contact with the conductive layer.

  The pressure-sensitive adhesive layer further contains a migration inhibitor. This migration inhibitor is a substance that directly or indirectly suppresses the occurrence of metal ion migration, and a moisture absorbent and / or metal ion scavenger can be used. For this reason, the water molecule attracted to the pressure-sensitive adhesive layer is extremely easy to come into contact with the migration inhibitor. The moisture absorbent has a function of adsorbing and holding water molecules present in the system, and this function indirectly prevents contact between the water molecules that cause ionization of the metal and the metal. Suppress migration. In addition, the metal ion scavenger has a function of capturing and holding metal ions present in the system, and this function directly suppresses migration by capturing the metal ions and making them impossible to move.

  Therefore, even if moisture entering from the outside reacts with a metal material such as silver constituting the conductive layer to ionize the metal material, if the moisture absorber is used as the migration inhibitor, Since water molecules that trigger ionization are adsorbed by the moisture absorbent, the ionization reaction itself is inhibited. For this reason, metal ions that should cause migration are hardly generated in the system, and as a result, disconnection or short-circuiting of the conductive layer due to migration can be suppressed.

  In addition, even when moisture entering from the outside reacts with a metal material such as silver constituting the conductive layer to ionize the metal material, when using a metal ion scavenger as a migration inhibitor, Metal ions generated in the system are trapped by the metal ion scavenger. For this reason, since the density | concentration of the metal ion which can be migrated in a system becomes very small, the disconnection and short circuit of a conductive layer resulting from migration can be suppressed as a result.

  As the migration inhibitor, either a water absorbent or a metal ion scavenger may be used, or both may be used. When both a water absorbent and a metal ion scavenger are used as a migration inhibitor, water molecules that cause ionization can be adsorbed by the water absorbent as the first stage, and the water absorbent is temporarily used as the second stage. Even if the water molecules that could not be adsorbed by the reaction with the metal material generate metal ions, the metal ions can be captured by the metal ion scavenger, so that the disconnection and short circuit of the conductive layer can be suppressed more reliably.

  In addition, there exists a technique using the reducing agent (reducible compound) disclosed by patent document 2 instead of a migration inhibitor. However, since the reducing agent causes a chemical reaction to chemically reduce the substance, there is a possibility that the reducing agent chemically reacts with a substance existing in the system other than the metal ion to reduce and denature it. On the other hand, the migration inhibitor used in the transparent conductive sheet of the present embodiment, that is, the moisture absorbent and the metal ion scavenger only have a physical action such as adsorption / trapping on the substance. Compared with the agent, substances existing in the system other than metal ions are not denatured. Therefore, in the touch panel device manufactured using the transparent conductive sheet of the present embodiment, the pressure-sensitive adhesive layer and the conductive layer in contact therewith are not modified, and a stain or the like does not occur on the image display surface.

  Next, each layer which comprises a transparent conductive sheet is demonstrated in detail. First, the copolymer monomer component of the acrylic copolymer contained in the pressure-sensitive adhesive layer is a hydrophilic acrylic containing at least one hydrophilic group selected from the group consisting of a hydroxyl group, an alkoxy group, an amino group, and an amide group. At least system monomers are used.

  As the hydrophilic acrylic monomer, any known acrylic monomer containing at least one of a hydroxyl group, an alkoxy group, an amino group, and an amide group as a hydrophilic group can be used without limitation. Further, the hydrophilic acrylic monomer may contain two or more hydrophilic groups in one molecule, or may contain two or more hydrophilic groups in one molecule. Examples of such hydrophilic acrylic monomers include the monomers described below.

  Examples of the hydrophilic acrylic monomer containing a hydroxyl group include (meth) acrylates containing a hydroxyl group, and specific examples include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxy. A hexyl (meth) acrylate etc. can be mentioned.

  Examples of hydrophilic acrylic monomers containing alkoxy groups include (meth) acrylates containing alkoxy groups, and specifically include methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and ethoxydiethylene glycol (meth). Examples thereof include acrylate, methoxypolyethylene glycol (meth) acrylate, and ethoxypolyethylene glycol (meth) acrylate.

  Examples of the hydrophilic acrylic monomer containing an amino group include (meth) acrylates containing an amino group and having 1 to 20 carbon atoms, specifically, N, N-dimethylaminoethyl (meth) acrylate, N-acryloylmorpholine and the like can be mentioned, but N, N-dimethylaminoethyl (meth) acrylate is preferable from the viewpoint of copolymerizability.

  Examples of the hydrophilic acrylic monomer containing an amide group include (meth) acrylates containing an amide group and having 1 to 20 carbon atoms. Specifically, (meth) acrylamide, N-methylacrylamide, N, N-dimethyl (meth) acrylamide, aminoethyl (meth) acrylamide, N-methylaminoethyl (meth) acrylamide, and the like, but from the viewpoint of hydrophilicity, a monomer species in which hydrogen on the N atom is not substituted Are preferred, and (meth) acrylamide is particularly preferred.

  Moreover, the monomer containing 2 or more types of the said hydrophilic group can also be used. Examples of the monomer containing two or more hydrophilic groups include N-methylolacrylamide containing a hydroxyl group and an amide group.

  From the viewpoint of securing the hydrophilicity of the acrylic copolymer, the blending ratio of the hydrophilic acrylic monomer in the copolymerization monomer component of the acrylic copolymer is 15% by mass of the total weight of the acrylic copolymer. That is necessary. If the blending ratio is less than 15% by mass, it becomes difficult to attract the water molecules entering from the outside to the pressure-sensitive adhesive layer and bring the migration inhibitor into contact with the water molecules. The blending ratio in the case of using a hydrophilic acrylic monomer containing a functional group involved in crosslinking or a hydroxyl group, amino group or amide group that has a crosslinking accelerating action by a crosslinking agent described later is 15% by mass or more and 40% by mass. Or less, more preferably 15% by mass or more and 30% by mass or less. In addition, when the alkoxy group-containing hydrophilic acrylic monomer is used, the blending ratio is preferably 30% by mass or more and 99% by mass or less, and more preferably 40% by mass or more and 95% by mass or less. When a hydrophilic acrylic monomer containing a hydroxyl group, an amino group or an amide group and an alkoxy group-containing hydrophilic acrylic monomer are used in combination, the total is preferably 17% by mass or more, and 19% by mass % Or more is more preferable.

  In addition, as a copolymerization monomer component of the acrylic copolymer, the blending ratio of the hydrophilic acrylic monomer containing a hydrophilic group is adjusted so that the hydrophilicity of the acrylic copolymer is appropriate, or the pressure-sensitive adhesive layer From the viewpoint of ensuring other necessary characteristics in a well-balanced manner, it is preferable to include other monomers other than the hydrophilic acrylic monomer containing a hydrophilic group.

  As other monomers, known monomers can be used as appropriate, but it is usually preferable to use a monomer that does not contain any of a hydroxyl group, an alkoxyl group, an amino group, and an amide group, and this monomer may be an acrylic monomer. It may be a non-acrylic monomer. Examples of such hydrophobic monomers include acrylic monomers having an alkyl group having 1 to 20 carbon atoms, and specifically include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl. Examples include (meth) acrylic acid alkyl esters such as (meth) acrylate and 2-ethylhexyl acrylate. The weight average molecular weight of the acrylic copolymer is not particularly limited, but is preferably 100,000 to 2,000,000, and more preferably 300,000 to 200,000, in order to adjust the wettability to the conductive layer and the balance of the adhesive performance. More preferably, it is 1.5 million.

  Moreover, as a water | moisture-content absorber used as a migration inhibitor contained in an adhesive layer, in the temperature environment (about 0-50 degreeC) by which a touchscreen apparatus is normally utilized, it is a well-known well-functioning thing which can adsorb | suck and hold | maintain a water molecule. Substance is available. Specifically, i) inorganic water absorbents include, for example, zeolite, silica gel, activated alumina and the like, and ii) organic water absorbents include water-absorbing polymers such as polyacrylamide; glycerin, polyethylene glycol Examples thereof include polyhydric alcohols and polymers thereof; cellulose polymers such as methyl cellulose; hyaluronic acid; collagen.

  Moreover, as a metal ion scavenger used as a migration inhibitor contained in the pressure-sensitive adhesive layer, a well-known high function capable of capturing and holding metal ions in a temperature environment (about 0 to 50 ° C.) in which a touch panel device is normally used. In general, a substance having a group / structure (amino group, phosphino group, thiol group, ether bond, etc.) coordinated to a metal can be preferably used.

  Specific examples include metal chelate compounds such as acetylacetone, adenine, 2-aminoethanol, 2-aminoethanethiol, imidazole, ethylamine, ethylenediamine, catechol, diethylenetriamine, triethylenetetramine, pyridine, and 1,10-phenanthroline. .

  In addition, it forms chelates with crown ethers such as 18-crown-6-ether, tribenzo-18-crown-6-ether, dibenzo-18-crown-6-ether, 15-crown-5-ether, and metal ions. Examples thereof include chelate resins into which functional groups / structures such as polyamines and glucamine groups are introduced.

  As the metal ion scavenger, one having a high metal ion scavenging ability can be appropriately selected according to the metal material constituting the conductive layer. For example, when the metal ions to be captured are silver ions or copper ions, it is preferable to use 18-crown-6-ether, diethylenetriamine, or the like.

  The blending ratio of the migration inhibitor contained in the pressure-sensitive adhesive layer is not particularly limited. However, in order to avoid insufficient suppression of migration, the blending ratio is preferably 0.05% by mass or more, more preferably 0.2% by mass or more, and further preferably 0.5% by mass or more. Further, the blending ratio is preferably 10% by mass or less, more preferably 7% by mass or less, and more preferably 4% by mass or less because the effect of suppressing migration is saturated even when the blending ratio is too much. More preferably.

  The method for forming the pressure-sensitive adhesive layer is not particularly limited. Usually, a coating liquid containing a hydrophilic polymer and a migration inhibitor is applied to the surface of a support (also referred to as a separator), and volatile components are dried. The pressure-sensitive adhesive layer can be formed by curing for a certain period as necessary. It does not restrict | limit especially about drying conditions and curing conditions, A conventionally well-known method is employable. In addition to the hydrophilic polymer and the migration inhibitor, if necessary, a coating solution containing a reactive diluent is applied to the surface of the support and irradiated with active energy rays to form the adhesive layer. It can also be formed. In addition to the hydrophilic polymer and migration inhibitor, if necessary, a coating solution containing a polyfunctional monomer, a crosslinking agent, and a solvent is applied to the surface of the support, dried, and then applied to the adherend. In addition, the pressure-sensitive adhesive layer can be formed on the adherend by irradiating active energy rays. The reactive diluent is a chemical species having a polymerizable functional group such as a vinyl group, and refers to a chemical species having a relatively low molecular weight such as a monomer or an oligomer. Specifically, the monomer seed | species which comprises the acrylic type copolymer used for the transparent conductive sheet of this embodiment may be sufficient.

Examples of the active energy rays include ultraviolet rays, visible rays, infrared rays, and electron beams. The irradiation conditions of the active energy ray, usually, carried illuminance active energy rays 1~200mW / cm ² integrated light amount 300~500mJ / cm ² irradiation to. The polymerization rate by irradiation is preferably 90 to 100%. The polymerization rate can be determined by measuring the amount of residual monomer by gas chromatography. Although the thickness of an adhesive layer can be selected suitably, it is about 1-200 micrometers normally.

  As the support, known supports can be used as long as the coating layer can be formed. For example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, diacetyl cellulose film, Acetyl cellulose film, acetyl cellulose butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyether ether Ketone film, polyethersulfone film, polyetherimide film, polyimide film, fluorine resin film Beam, nylon film, a resin film such as an acrylic resin film.

  Further, the surface of the support may have releasability. In the case of a support having a releasable surface, a coating layer is formed on the surface having the releasability. Moreover, when using the transparent conductive sheet of this embodiment, the support body in which the surface has releasability is peeled from an adhesive layer beforehand before use. On the other hand, when the surface of the support does not have releasability, a transparent support that is transparent to at least the visible light region is used as the support.

  Moreover, the adhesive used for formation of an adhesive layer can be produced in the following procedures, for example. First, a raw material monomer containing a hydrophilic acrylic monomer is charged into a reaction vessel, heated to a predetermined temperature in an inert gas atmosphere such as nitrogen gas, and then a thermal polymerization initiator is added and reacted for a predetermined time. The thermal polymerization reaction is desirably allowed to proceed sufficiently so that unreacted raw material monomers do not remain. The migration inhibitor may be added to the raw material monomer or after polymerization.

  As the thermal polymerization initiator used in the thermal polymerization reaction, known thermal polymerization initiators can be used, and examples thereof include organic peroxides, organic hydroperoxides, organic peroxyketals, and azo compounds. .

  Here, as the organic peroxides, for example, dicumyl peroxide, di-tert-butyl peroxide, tert-butyl cumyl peroxide, dilauroyl peroxide, dibenzoyl peroxide, diacetyl peroxide, didecanoyl peroxide Examples thereof include oxide, diisononanoyl peroxide, and 2-methylpentanoyl peroxide. Organic hydroperoxides include tert-butyl hydroperoxide, cumyl hydroperoxide, 2,5-dimethyl-2,5-dihydroperoxyhexane, p-methane hydroperoxide, diisopropylbenzene hydroperoxide. Examples thereof include -oxide, t-hexyl peroxypivalate, t-butyl peroxypivalate, dimethyl-2,2'-azobismethylpropionate and the like.

  Organic peroxyketals include 1,1-bis (tert-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (tert-hexylperoxy) cyclohexane, 1,1- Bis (tert-butylperoxy) 3,3,5-trimethylcyclohexane is the azo compound. 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile , 2,2′-azobiscyclohexylnitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, dimethyl-2,2′-azo Examples thereof include bisisobutyrate.

  These polymerization initiators can be used in the range of 0.0001 parts by mass to 10 parts by mass with respect to 100 parts by mass of the raw material monomer.

  In addition, in order to control the weight average molecular weight Mw of the hydrophilic polymer, it is adjusted by adjusting the reaction conditions such as the type and amount of the thermal polymerization initiator, the reaction time and the reaction temperature, or using a chain transfer agent as appropriate. can do. Examples of the chain transfer agent include methyl mercaptan, n-dodecyl mercaptan, 2-mercaptoethanol, mercaptoisobutyl alcohol, thioglycerol, methyl thioglycolate, α-methylstyrene dimer, and the like.

  Moreover, you may use crosslinking agents, such as an isocyanate type crosslinking agent and an epoxy type crosslinking agent, suitably for an adhesive. The compounding quantity of a crosslinking agent can be made into the range of 0.01 mass part-20 mass parts with respect to 100 mass parts of acrylic copolymers.

  Examples of isocyanate crosslinking agents include isocyanate monomers such as tolylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, and trimethylolpropane. Illustrative examples include isocyanate compounds or isocyanurates obtained by addition reaction with bivalent or higher alcohol compounds and the like, burette type compounds and the like. Further, urethane prepolymer type isocyanates obtained by adding an isocyanate compound to known polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, and the like can be used.

  Epoxy crosslinking agents include bisphenol A epichlorohydrin type epoxy resin, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol glycidyl ether, trimethylolpropane triglycidyl. Examples include ether, diglycidyl aniline, diamine glycidyl amine, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N′-diamine glycidylaminomethyl) cyclohexane, and the like. .

  In addition, various additives such as an ultraviolet absorber, an antioxidant, and an antifoaming agent, and other polymers other than the hydrophilic polymer can be further added to the pressure-sensitive adhesive as necessary.

  The conductive layer contains a metal material, and the layer structure is not particularly limited as long as it has conductivity. For example, a metal having a diameter of several nanometers to several hundreds of nanometers and a length of about 1 μm to several hundreds of micrometers Conductive layer composed of an assembly of nanowires, metal film or conductive layer formed by patterning a film containing metal components such as metal fine particles with a diameter of several nanometers to several hundreds of nanometers into a predetermined shape, a diameter of several tens of micrometers to For example, a conductive layer using a metal wire of about several hundred μm as it is can be exemplified. Note that when metal nanowires or metal fine particles are used in forming the conductive layer, a solution or paste containing these metal materials in a dispersed manner can be used. As the metal element constituting the conductive layer, a known conductive metal can be used as appropriate, and examples thereof include Ag, Cu, and Au, and Ag is particularly preferable. In addition, when metal nanowires or metal fine particles are used as the metal component constituting the conductive layer, in addition to these metal components, the binder component or the like is used for maintaining and forming the shape of the conductive layer. The other components may be further included.

  Furthermore, the conductive layer is provided in contact with the pressure-sensitive adhesive layer. For this reason, the layer structure of a transparent conductive sheet or a touch panel module and a touch panel device produced using the same can be simplified and made thinner. The conductive layer is provided in contact with at least one surface of the pressure-sensitive adhesive layer (hereinafter referred to as “conductive layer forming surface”), but is provided so as to substantially cover the entire surface of the conductive layer forming surface without any gap. Instead, it is provided so as to cover a part of the conductive layer forming surface and to form a predetermined pattern shape. The pattern shape is not particularly limited as long as both the transparency in the whole plane direction necessary for functioning as a touch panel device and the sensing function can be compatible. In addition, the coverage of the conductive layer on the conductive layer forming surface can be selected as appropriate as long as the function as a touch panel device can be secured. For example, the range is from 0.1% to 70%, preferably from 1% to 50%. Of these, it is possible to appropriately select within a range of 2% to 40%.

Examples of such a pattern shape include those exemplified in the following (i) to (iii) in a plane space composed of a first direction and a second direction orthogonal to the first direction.
(I) A substantially square conductive region is electrically connected to a vertex of one conductive region and a vertex of another conductive region along the first direction (for example, two vertices are partially A pattern shape (for example, Japanese Patent Application Laid-Open No. 2012-79257) in which a plurality of conductive region rows formed by arranging a plurality of rows so as to overlap each other so as to connect two vertices are arranged along the second direction. The pattern shape illustrated in FIG.
(Ii) In the pattern shape (i), each conductive region has a pattern shape formed by arranging strip-shaped wiring so as to form a lattice shape (for example, FIG. 3 of JP 2012-33147 A). Etc.).
(Iii) A plurality of rows of strip-like conductive regions whose longitudinal direction is parallel to the first direction are arranged along the second direction, and each of the conductive regions is arranged so that the strip-like wiring forms a grid. The pattern shape formed by this (for example, the pattern shape illustrated by FIG. 7, 8 etc. of Unexamined-Japanese-Patent No. 2014-198811 etc.).

  The method for forming the conductive layer is not particularly limited, and a known method can be used as it is, or can be appropriately arranged and used, or two or more known methods can be used in combination. For example, a support with a conductive layer can be produced by the methods exemplified in the following (A) to (C).

(A) A method of patterning the metal film after forming a metal film on the surface of the support by a known film forming method such as sputtering, vacuum deposition, or electroless plating.
In this case, in the patterning, after further forming a photoresist film on the metal film, the photoresist film is exposed and developed to form a resist pattern, and the metal film exposed from the resist pattern is etched and selectively removed. Finally, the photoresist film remaining on the patterned metal film (conductive layer) is removed. Thereby, a support body with a conductive layer can be obtained.

(B) A method of forming a conductive layer on a support surface by printing a solution or paste containing metal nanowires or metal fine particles in a predetermined pattern shape (for example, see JP 2012-79257 A).
As the printing method, known printing such as offset printing, letterpress printing, intaglio printing, screen printing, ink jet printing and the like can be used. In addition, you may perform a heat processing and a pressurization process as needed after printing.

(C) A photosensitive layer is formed by applying a photosensitive composition containing silver halide and a binder to the surface of the support, and then exposing and developing the photosensitive layer to form a predetermined pattern shape. A method for forming a conductive layer having the conductive layer (see, for example, JP-A-2014-198811).

  Hereinafter, as an example, the case where a support with a conductive layer is produced by the method shown in (B) above will be described more specifically.

  In this case, first, a solution containing metal nanowires in a dispersed manner is applied to the surface of the first support (the surface having releasability), then dried, and further subjected to pressure treatment, so that a solid film shape is obtained. A conductive film is formed. Thereby, the 1st support body with an electrically conductive film is obtained. In addition, a heat-sensitive adhesive (for example, polyurethane-based adhesive) that does not exhibit tackiness at normal temperature but develops tackiness upon heating is screen-printed on the surface of the second support so as to have a predetermined pattern shape. Form using. Thereby, the 2nd support body with a heat-sensitive adhesive layer is obtained.

  Next, the first support with a conductive film and the second support with a heat-sensitive adhesive layer are heated and pressurized by a roll laminating method or the like so that the conductive film and the heat-sensitive adhesive layer are in close contact with each other. Paste. Subsequently, by peeling the second support from the first support, only the part corresponding to the pattern shape of the heat-sensitive adhesive layer of the conductive film provided on the surface of the first support is directed to the heat-sensitive adhesive layer side. Transition. As a result, a conductive film (conductive layer) having a pattern shape obtained by inverting the pattern shape of the heat-sensitive adhesive layer is formed on the surface of the first support.

  Here, when producing the transparent conductive sheet of this embodiment using the support body with a conductive layer which has the predetermined pattern shape obtained by the method illustrated to said (A)-(C), for example, the following A transparent conductive sheet can be produced by the procedure described above. First, the support body with an adhesive layer which prepared the adhesive layer which comprises the transparent conductive sheet of this embodiment on the surface of a support body is prepared.

  Next, the support with the conductive layer and the support with the pressure-sensitive adhesive layer are bonded together while being pressed by a roll laminating method or the like. At the time of bonding, the pressure-sensitive adhesive layer may be heated as necessary as long as the performance of the pressure-sensitive adhesive layer does not deteriorate. Thereby, the laminated body A by which the support body, the electroconductive layer, the adhesive layer, and the support body were laminated | stacked in this order can be obtained. In addition, the conductive layer, the pressure-sensitive adhesive layer, and the support can be separated from each other by transferring the conductive layer to the surface of the pressure-sensitive adhesive layer by peeling the support that is in contact with the conductive layer from the laminate A. The laminated body B laminated | stacked in order can be obtained. Moreover, the laminated body C which provided the protective layer in the surface by which the conductive layer of the laminated body B was provided can also be obtained. Furthermore, after peeling the support body contacted with the pressure-sensitive adhesive layer from the laminate A, the first support body, the first conductive layer, and the pressure-sensitive adhesive layer are further bonded to a support body with a conductive layer. And the laminated body D which laminated | stacked the 2nd conductive layer and the 2nd support body in this order can be obtained. Here, as the support used for forming the conductive layer and the protective layer, members of the same material as the support used for forming the pressure-sensitive adhesive layer can be used.

  In this case, the laminated body A, the laminated body B, the laminated body C, or the laminated body D can be used as the transparent conductive sheet of this embodiment. Moreover, you may use a support body with an adhesive layer as a support body of the method illustrated to said (A)-(C), and form a conductive layer directly on the surface of an adhesive layer. However, in this case, in the process of forming the conductive layer, it is preferable to select a conductive layer forming process that does not significantly deteriorate the adhesive properties of the pressure-sensitive adhesive layer surface. As exemplified above, transparent conductive sheets having various layer structures can be obtained by appropriately combining various manufacturing processes and intermediate members.

  Next, the transparent conductive sheet of this embodiment will be described more specifically with reference to the drawings. FIG. 1 and FIG. 2 are schematic plan views showing an example of the transparent conductive sheet of the present embodiment, specifically, an example showing the pattern shape of the conductive layer. In the figure, the X direction and the Y direction indicated by arrows are directions orthogonal to each other.

  In the transparent conductive sheet 10A (10) shown in FIG. 1, the square conductive region 100A (100) is partially divided in the X direction from the vertex of one conductive region 100A and the vertex of the other conductive region 100A. A conductive layer 20 </ b> A (20) having a pattern shape in which a plurality of conductive region rows 110 </ b> A (110) formed by arranging a plurality of rows in an overlapping manner is arranged along the Y direction. In the example shown in FIG. 1, lead electrode portions 112 are further provided on both ends in the X direction of the conductive region row 110A (110). In addition, the transparent conductive sheet 10B (10) shown in FIG. 2 has a pattern-shaped conductive layer 20B (a plurality of rows of strip-shaped conductive regions 100B (100) whose longitudinal direction is parallel to the X direction along the Y direction. 20). In the example shown in FIG. 2, one conductive region 100B constitutes one conductive region row 110B (110). In FIG. 1 and FIG. 2, the conductive region columns 110 are not connected but are electrically insulated. In addition to this, in the touch panel module and touch panel device to be described later, each conductive region row 110 shown in FIGS. 1 and 2 is a sensor composed of a printed wiring board (not shown) or the like via a lead wiring (not shown). Connected to the part.

  The conductive region 100 shown in FIGS. 1 and 2 may be a transparent solid film-like member, but may further have a secondary structure as illustrated in FIG. FIG. 3 is an enlarged plan view showing an example when the conductive region 100 shown in FIGS. 1 and 2 is enlarged. In the example shown in FIG. 3, the conductive region 100 has a secondary structure in which strip-like wirings 102 are arranged in a grid pattern.

  As illustrated in FIGS. 1 and 2, the conductive layer 20 usually includes a plurality of conductive regions 100 and is connected to each other between at least two conductive regions 100 selected from the plurality of conductive regions 100. It is arrange | positioned so that it may be electrically insulated without being. For this reason, in the narrowest part of the line width, such as the Y direction length of the connecting portion 120 of the two adjacent conductive regions 100A shown in FIG. 1 or the Y direction length of the conductive region 100B shown in FIG. If migration of the metal material constituting the conductive layer 20 occurs, disconnection is likely to occur. Further, the apex of the conductive region 100A constituting the first conductive region row 110A shown in FIG. 1 on the second conductive region row 110A side and one row of the conductive region 100A constituting the second conductive region row 110A. The length (gap length G1) between the second conductive region column 110B and the first conductive region column 110B and the second conductive region column 110B shown in FIG. In the portion where the distance between the two electrically insulated conductive regions 100 is the shortest, such as the gap length G2), a short circuit is likely to occur when migration of the metal material constituting the conductive layer 20 occurs. However, in the transparent conductive sheet 10 of this embodiment, since migration due to moisture in the atmosphere is suppressed as described above, it is extremely easy to prevent disconnection or short circuit.

  The line width at the narrowest line width is not particularly limited, but can be in the range of 10 nm to 1000 μm, for example. The lower limit of the line width is preferably 100 nm or more, more preferably 500 nm or more, further preferably 1 μm or more, and the upper limit of the line width is preferably 200 μm, more preferably 50 μm or less, and even more preferably 10 μm or less. Further, the gap length in the portion where the distance between the two electrically insulated conductive regions 100 is the shortest is not particularly limited, but may be in the range of 1 μm to 5000 μm, for example. The lower limit of the shortest distance is preferably 5 μm or more, more preferably 10 μm or more, further preferably 50 μm or more, and the upper limit of the shortest distance is preferably 1000 μm, more preferably 500 μm or less, and even more preferably 10 μm or less.

  The thickness of the conductive layer 20 is not particularly limited, but can be selected from a range of, for example, 10 nm to 1000 μm from the viewpoint of conductivity and transparency. The lower limit of the thickness is preferably 50 nm or more, more preferably 100 nm or more, and the upper limit of the thickness is preferably 100 μm or less, more preferably 10 μm or less, and most preferably 5 μm or less.

  4 to 7 are schematic cross-sectional views showing an example of the cross-sectional structure of the transparent conductive sheet of the present embodiment, specifically, between A1 and A2 in FIG. 1 or B1 in FIG. It is a figure which shows an example of the cross-sectional structure in the part in which the conductive layer 20 exists between B2. The transparent conductive sheet 10C (10) shown in FIG. 4 has a layer structure in which the substrate 40, the adhesive layer 30, and the conductive layer 20 are laminated in this order, and the transparent conductive sheet 10D shown in FIG. (10) has a layer structure in which the first base material 40A (40), the pressure-sensitive adhesive layer 30, the conductive layer 20, and the second base material 40B (40) are laminated in this order. In the transparent conductive sheet 10E (10) shown in FIG. 6, the first base material 40A (40), the first conductive layer 20C (20), the pressure-sensitive adhesive layer 30, and the second conductive layer 20D (20). ) And the second substrate 40B are laminated in this order. In the transparent conductive sheet 10F (10) shown in FIG. 7, the first substrate 40A (40) and the first substrate 40B Adhesive layer 30A (30), first conductive layer 20C (20), third substrate 40C (40), second The conductive layer 20D (20), a second adhesive layer 30B (30), a second substrate 40B has a stacked layer structure in this order.

  The transparent conductive sheet 10 of the present embodiment is not limited to the layer structure illustrated in FIGS. 4 to 7 as long as it includes at least one conductive layer 20 and one adhesive layer 30, respectively. As illustrated in FIG. 7, the conductive layer 20 and / or the pressure-sensitive adhesive layer 30 may be included in two or more layers. Moreover, although the transparent conductive sheet 10 of this embodiment may be comprised only from the conductive layer 20 and the adhesive layer 30, from a practical viewpoint, such as the handleability of the transparent conductive sheet 10, it is usually 1 It is particularly preferable that the substrate 40 includes more than one layer.

  As the base material 40, when the transparent conductive sheet 10 is produced, the support used for forming the conductive layer 20 and the pressure-sensitive adhesive layer 30, the protection formed by applying a protective layer forming solution or bonding a protective sheet, etc. A layer etc. can be mentioned. In addition, when the base material 40 is a member located in the outermost surface of the transparent conductive sheet 10, in other words, when it is the base material 40 in FIG. 4, and the base materials 40A and 40B in FIGS. The surface on the side in contact with the agent layer 30 or the conductive layer 20 may have releasability. In this case, when assembling the touch panel device or the touch panel module, the transparent conductive sheet 10 is used in a state in which the base material 40 having a surface-releasing property is peeled off. In the assembly of the touch panel device or the touch panel module, the substrate 40 to be peeled may be a transparent member or an opaque member. In other cases, the substrate 40 is transparent. Various members are used.

  When a touch panel device or a touch panel module is assembled using the transparent conductive sheet 10A having the pattern-shaped conductive layer 20A shown in FIG. 1, two conductive layers 20A are used in combination. In this case, the second conductive layer 20A is rotated 90 degrees in the XY plane with respect to the first conductive layer 20A, and each conductive region 100A constituting the second conductive layer 20A is In the conductive layer 20A, the conductive layer 20A is disposed so as to be positioned in a substantially square non-conductive region 130 surrounded by four conductive regions 100A. Moreover, also when assembling a touch panel device or a touch panel module using the transparent conductive sheet 10B having the pattern-shaped conductive layer 20B shown in FIG. 2, the two conductive layers 20B are used in combination. In this case, the second conductive layer 20B is arranged to rotate 90 degrees in the XY plane with respect to the first conductive layer 20B.

  Therefore, when assembling a touch panel device or a touch panel module using two transparent conductive sheets 10C shown in FIG. 4, the conductive layer 20 of the first transparent conductive sheet 10C and the conductive layer 20 of the second transparent conductive sheet 10C. And the arrangement relationship described above may be obtained. The same applies to the transparent conductive sheet 10D shown in FIG. Moreover, when assembling a touch panel device or a touch panel module using the transparent conductive sheet 10E shown in FIG. 6, the first conductive layer 20C and the second conductive layer 20D may be arranged as described above. The same applies to the transparent conductive sheet 10F shown in FIG.

  The touch panel device according to the present embodiment includes an image display device, a conductive layer using a metal material as a conductive substance provided on the image display surface side of the image display device, and an adhesive layer in contact with the conductive layer. The configuration is not particularly limited as long as it is included, and the touch panel module of the present embodiment includes a conductive layer using a metal material as a conductive substance and a pressure-sensitive adhesive layer in contact with the conductive layer. If so, the configuration is not particularly limited. However, in the touch panel device and the touch panel module, the same conductive layer and pressure-sensitive adhesive layer as the transparent conductive sheet of the present embodiment are used.

  FIG. 8 is a schematic cross-sectional view showing an example of the touch panel device of the present embodiment, and specifically, a schematic cross-sectional view showing an example of the touch panel device manufactured using the transparent conductive sheet 10F shown in FIG. . In the touch panel device 200 shown in FIG. 8, the transparent conductive sheet 10 </ b> F is bonded to the image display surface side 212 of the image display device 210 via the first fixing adhesive layer 220. Further, a transparent protective layer 240 is bonded to the side of the transparent conductive sheet 10F opposite to the side on which the image display device 210 is disposed via a second fixing adhesive layer 230.

  Here, as the image display device, a known image display device such as a liquid crystal display device, an organic EL display device, or a plasma display device can be used. Examples of the transparent protective layer 240 include a hard plastic substrate such as a glass substrate and a polycarbonate substrate, a soft resin layer whose surface is hard-coated, a sapphire substrate, and the like. As the fixing pressure-sensitive adhesive layers 220 and 230, known pressure-sensitive adhesives can be used as appropriate, but pressure-sensitive adhesives having high transmittance with respect to wavelengths in the visible light region are used.

  Moreover, as a touch panel module of this embodiment, the member which can assemble a touch panel apparatus substantially by adhere | attaching or fixing to the image display surface of an image display apparatus in a touch panel apparatus is mentioned. In addition, the touch panel module includes a sensor unit composed of a printed circuit board connected to the conductive layer 20 as illustrated in FIGS. 1 to 7, a lead wiring for connecting the sensor unit and the conductive layer 20, and the like. May further be included. For example, in the touch panel device 200 shown in FIG. 8, a member including a laminate in which the transparent conductive sheet 10F, the second fixing adhesive layer 230, and the transparent protective layer 240 are stacked in this order corresponds to the touch panel module 300. . When manufacturing the touch panel device of this embodiment, you may form in order the layer which functions as a touch panel on the image display surface of an image display device using the transparent conductive sheet of this embodiment. However, if the touch panel module of the present embodiment, which is a modularized member as described above, is prepared in advance, the touch panel module can be substantially simply attached to the image display surface of the image display device. A touch panel device can be manufactured.

  The touch panel device of the present embodiment is particularly preferably a capacitive touch panel device, but may be another type of touch panel device. In addition, the touch panel device of the present embodiment can be used for everything from a small screen having a diagonal line (screen size) of several inches to a large screen having several tens of inches or more than a hundred inches, such as a smartphone. It can be used in the screen size. The use of the touch panel device according to the present embodiment is not particularly limited. For example, a smartphone, a mobile phone, a notebook computer, a display monitor for a personal computer, a tablet terminal, a ticket vending machine, an ATM, having a screen size of about several inches to several tens of inches. Not only can it be used for various office equipment and industrial equipment display monitors, but it can also be used for home or commercial televisions with a screen size of about 20 to several tens of inches, and more than 20 screen sizes. Applications such as electronic signage (digital signage) of about an inch or more, guidance display boards, office equipment with image display devices such as table conference systems and whiteboards, and amusement equipment that require display on a larger screen are also included.

  However, the touch panel device of the present embodiment is not a conductive layer using a metal oxide such as ITO as a conductive substance, but a touch panel using a conductive layer using a metal material having a resistance lower than that of ITO. Since this function is implemented, it is suitable for applications that require a large screen display. From such a viewpoint, the diagonal length of the transparent conductive sheet, the touch panel module and the touch panel device of the present embodiment is preferably 8 inches or more, more preferably 12 inches or more, and 15 inches or more. Is more preferable. The upper limit of the diagonal length is not particularly limited, but is preferably 500 inches or less, and more preferably 300 inches or less, from a practical viewpoint such as handleability.

  In addition, when a moisture absorbent is included in the pressure-sensitive adhesive layer constituting the touch panel device of the present embodiment, the moisture absorbent adsorbs water molecules, so that the adsorption capacity of the moisture absorbent present in the system gradually decreases. Come on. However, when the power of the image display device is ON, the image display surface becomes larger and smaller and generates heat. Therefore, the adsorption capacity of the moisture absorbent can be recovered using heat from the image display surface side. Further, in order to more intentionally recover the adsorption capacity of the moisture absorbent, the touch panel device according to the present embodiment may have a function of energizing and heating the conductive layer and its surroundings by passing a current through the conductive layer. .

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

(Preparation of support with conductive layer)
1. Production of Support with Conductive Film As a solution in which metal nanowires are dispersed, an ethanol solution containing 0.625 wt% of silver nanowires (Silver Nanowires B Research Grade φ50 nm × 40 um, EM Japan Co., Ltd.), and copper nanowires ( Copper Nanowires A1 Research Grade φ100 nm × 30 μm, EM Japan Co., Ltd.) was prepared with an ethanol solution containing 0.625 wt%. Next, the ethanol solution containing each metal nanowire was hard-coated with a first support (thickness: 188 μm, high-transparency PET film (HF1C22-188) hard coated on one side) using a slot die coater. After applying a wet thickness of 20 μm on the surface and drying, pressure treatment was performed at a pressure of 2000 kN / m ² to form a uniform conductive film. Thereby, the support body with the electrically conductive film which consists of silver nanowires, and the support body with the electrically conductive film which consists of copper nanowires were obtained.

2. Production of Support with Heat-Sensitive Adhesive Layer Further, 100 parts by mass of CRISVON NT-810-45 (polyurethane resin manufactured by DIC, 45% solution) was dissolved in 62.5 parts by mass of methyl ethyl ketone and 62.5 parts by mass of toluene. An adhesive solution was prepared. Then, this thermal adhesive solution is subjected to pattern printing by a gravure printing method on a second support having a releasable surface (PET film having a thickness of 23 μm (Teijin Tetron Film G2 manufactured by Teijin DuPont Films)). By drying the coating film, a heat-sensitive adhesive layer having a thickness of about 0.5 μm to 0.8 μm was formed. The pattern shape of the heat-sensitive adhesive layer formed by pattern printing was a pattern shape (negative pattern shape) obtained by inverting the pattern shape shown in FIG. Here, the negative pattern shape is a pattern shape of the conductive layer 20B finally formed as shown in FIG. 2, and the line width of the conductive region 100B and the interval between two adjacent conductive regions 100B (gap length G2). ), A pattern shape with (line width, interval) = (10 μm, 190 μm) and a pattern shape with (line width, interval) = (20 μm, 180 μm) were prepared.

3. Production of Support with Conductive Layer Next, a first support with a conductive film and a second support having a heat-sensitive adhesive layer patterned in a negative pattern shape are obtained by combining a conductive film and a heat-sensitive adhesive layer. In a state where they are stacked so as to face each other, they are heated and pressurized by inserting between a pair of opposed rolls (metal heating roll and heat-resistant silicon roll) constituting the laminator, and a support with a conductive film and a heat-sensitive adhesive A support having a layer was laminated. The laminating conditions at this time were a metal heating roll temperature of 110 ° C., a roll nip pressure (linear pressure) of 30 kN / m, and a conveying speed of 5 m / min of the two superposed substrates passing between the pair of rolls. . Subsequently, when the temperature of the laminate obtained by bonding is lowered to about room temperature, the second support is peeled off from the laminate, whereby the conductive pattern having the pattern shown in FIG. 2 is formed on the first support. A support with a conductive layer in which the film (conductive layer 20B) remained was obtained.

  In addition, the conductive layer of the obtained support body with a conductive layer (first support body) was observed with a microscope. As a result, in any support with a conductive layer, the conductive layer was not damaged by the peeling step of peeling the second support, and the conductive film in the region that was in contact with the heat-sensitive adhesive layer was All were transferred to the second support side, and did not remain on the first support side. In addition, for each of the obtained support with a conductive layer, in order to quantitatively determine defective products resulting from the peeling process, the resistance value and the light transmittance were measured, and each value was ± 10% from the average value. Only the support with conductive layer within the range was selected and used for the production of transparent conductive sheets of Examples and Comparative Examples described later.

(Synthesis of polymer for adhesive layer)
The following monomers were used for the synthesis of the polymer used for the production of the pressure-sensitive adhesive layer.
<Hydrophilic acrylic monomer>
2HEA: 2-hydroxyethyl acrylate 2HEMA: 2-hydroxyethyl methacrylate 4HBA: 4-hydroxybutyl acrylate AM: acrylamide MEA: methoxyethyl acrylate ECA: ethoxydiethylene glycol acrylate

<Other monomers>
BA: n-butyl acrylate 2EHA: 2-ethylhexyl acrylate

<Synthesis of Polymer A1>
A reactor equipped with a stirrer, reflux condenser, thermometer, and nitrogen inlet pipe was charged with 2 HEA: 20 parts by mass, AM: 1 part by mass, BA: 69 parts by mass, 2EHA: 10 parts by mass and ethyl acetate as a solvent. The temperature was raised to 70 ° C. while introducing nitrogen gas. Next, 0.1 part by mass of a thermal polymerization initiator (2,2′-Azobisisobutyronitrile), trade name: AIBN, manufactured by Wako Pure Chemical Industries, Ltd.) was added with stirring and reacted for 10 hours to produce an acrylic copolymer (polymer). A1) was obtained. Table 1 shows the composition of the monomers used for the synthesis of the polymer A1.

<Synthesis of Polymers A2 to A30, B1 to B22, C1>
The synthesis was performed in the same manner as in the synthesis example of Polymer A1, except that the composition of the monomer used for the synthesis of the polymer was changed to the contents shown in Table 1. Table 1 shows the composition of the monomers used in the synthesis of these polymers.

(Preparation of transparent conductive sheet)
<Example 1>
Polymer A1: 100 parts by mass of trimethylolpropane-added tolylene diisocyanate (Coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.) as an isocyanate-based crosslinking agent and synthetic zeolite (silica) as a migration inhibitor / Alumina ratio = 18) 1 part by mass was added and defoamed while mixing to obtain a coating solution containing polymer A1. Next, the coating solution containing the polymer A1 is applied onto a support (polyethylene terephthalate (PET) film having a thickness of 100 μm) so that the thickness after drying is 50 μm, dried, and then subjected to a peeling treatment on the coated surface. The resulting PET film (thickness 25 μm) was bonded to prepare a support with an adhesive layer.

  Next, it has a pattern shape of (line width, interval) = (10 μm, 190 μm), a support with a conductive layer using silver nanowires and a support with an adhesive layer from which a peeled PET film has been peeled off The body was bonded so that the surface on which the conductive layer of the support with a conductive layer was formed and the surface on which the pressure-sensitive adhesive layer was formed on the support with the pressure-sensitive adhesive layer faced each other. The laminating is performed using the same laminator as that used for the production of the support with the conductive layer. The laminating conditions at this time are a roll nip pressure (linear pressure) of 30 kN / m and a pair. The conveying speed of the two superposed substrates passing between the rolls was 5 m / min. Then, the obtained laminate was allowed to stand at a temperature of 23 ° C. and a humidity of 65% for 7 days, whereby the pattern shape shown in FIG. 2 and the layer structure shown in FIG. 5 (first base material 40A (third support) A transparent conductive sheet having / adhesive layer 30 / conductive layer 20B / second base material 40B (first support) was obtained.

<Examples 2 to 30 and Comparative Examples 1 to 22>
A transparent conductive sheet was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer and the pattern shape of the conductive layer were changed to the contents shown in Tables 2 and 3.

<Reference Example 1>
An ITO film having a thickness of 200 nm was formed on the surface of the alkali-free glass substrate by a sputtering method. Next, after a resist film was formed on the ITO film, the resist film was exposed and developed using a photomask having a shape obtained by inverting the pattern shape shown in FIG. 2, and the resist film was patterned. Next, the ITO film-coated glass substrate on which the patterned resist film was formed was etched using an etchant, and then the resist film remaining on the ITO film was removed with a resist stripper. This obtained the glass substrate with the conductive layer which consists of an ITO film | membrane which has the pattern shape (Line width: 20 micrometers, space | interval: 180 micrometers) shown in FIG.

  Next, in Example 1, instead of the support with a conductive layer, the glass substrate with a conductive layer composed of the ITO film described above was attached to form a laminate, and then the support with the adhesive of this laminate was supported. Pressure was applied using a roller from the side where the body was provided. Subsequently, this laminated body was allowed to stand at a temperature of 23 ° C. and a humidity of 65% for 7 days, whereby the pattern shape shown in FIG. 2 and the layer structure shown in FIG. 5 (first substrate 40A (third support) / A transparent conductive sheet having pressure-sensitive adhesive layer 30 / conductive layer 20B / second base material 40B (non-alkali glass substrate)) was obtained.

(Evaluation)
When the external appearance of the transparent conductive sheet of each Example, Comparative Example and Reference Example was visually observed, the entire surface was transparent. Further, for the transparent conductive sheets of each Example, Comparative Example and Reference Example, migration, resistance value change rate and peeling resistance were evaluated, and the weight average molecular weight Mw of the polymer used for forming the adhesive layer was also measured. . Details are shown below.

<Measurement of weight average molecular weight Mw>
In addition, the weight average molecular weight Mw of each polymer shown in Table 1 was calculated | required as weight average molecular weight Mw by standard polystyrene conversion using the gel permeation chromatography (GPC). The measurement conditions are shown below.
-Measurement conditions-
Apparatus: HLC-8120 (manufactured by Tosoh Corporation)
Column: G7000HXL (manufactured by Tosoh Corporation)
GMHXL (manufactured by Tosoh Corporation)
G2500HXL (manufactured by Tosoh Corporation)
Sample concentration: 1.5 mg / ml (diluted with tetrahydrofuran)
Mobile phase solvent: Tetrahydrofuran Flow rate: 1.0 ml / min
Column temperature: 40 ° C

<Migration>
A state in which a voltage of 3.3 V is applied to both ends of each strip-like conductive region row 110B (conductive region 100B) constituting the conductive layer 20B in FIG. Then, it was allowed to stand for 500 hours in a high temperature and high humidity environment (temperature 85 ° C., humidity 85%). Thereafter, the conductive layer of the conductive transparent sheet energized in a high-temperature and high-humidity environment and its vicinity were observed with a scanning electron microscope, and the presence or absence and the extent of migration were evaluated. The evaluation criteria for the results shown in Tables 2 and 3 are as follows.

○: No migration is observed at all.
Δ: Some migration was observed.
X: Remarkable migration was observed.

<Evaluation of resistance value change rate>
In order to evaluate the change of the resistance value caused by migration of the metal material constituting the conductive layer, the transparent conductive sheets of each Example, Comparative Example and Reference Example are positioned at one end side in the Y direction in FIG. The wire resistance (kΩ) was measured by connecting a tester to both ends of the conductive region row 110B (conductive region 100B).

Here, the wire resistance is the resistance value Ri in the initial state after producing the transparent conductive sheet, and the transparent conductive sheet after measuring the resistance value Ri in a high temperature and high humidity environment (temperature 85 ° C., humidity 85%). The resistance value Rw after standing for 500 hours was measured. And resistance value change rate RCw (%) at the time of leaving a transparent conductive sheet in a high temperature, high humidity environment was calculated | required by the following Formula (1). The results are shown in Tables 2 and 3.
Formula (1) RCw = 100 × (Rw−Ri) / Ri

The evaluation criteria for the results shown in Tables 2 and 3 are as follows.
○: Resistance value change rate RC is 2% or less.
(Triangle | delta): Resistance value change rate RC exceeds 2% and is 5% or less.
X: Resistance value change rate RC exceeds 5%.

<Evaluation of peeling resistance>
After sticking the test piece which cut | disconnected the support body with an adhesive layer used for preparation of the transparent conductive sheet of each Example, a comparative example, and a reference example to 5 cm x 6 cm on the surface of a glass substrate, the roller of 2 kg in weight was attached. Three reciprocations were applied for pressure bonding. After crimping, the specimen was left for 500 hours in a high-temperature and high-humidity environment (temperature 85 ° C., humidity 85%). The results are shown in Tables 2 and 3.

The evaluation criteria for the results shown in Tables 2 and 3 are as follows.
◯: No cracking or peeling was observed.
(Triangle | delta): Some squeezing and peeling were observed.
X: Uki and peeling were observed.

10, 10A, 10B, 10C, 10D, 10E, 10F: Transparent conductive sheet 20, 20A, 20B, 20C, 20D: Conductive layer 30, 30A, 30B: Adhesive layer 40, 40A, 40B, 40C: Base material 100, 100A, 100B: conductive region 102: wiring
110, 110A, 110B: Conductive region row 112: Lead electrode portion 120: Connection portion 130: Nonconductive region 200: Touch panel device 210: Image display device 212: Image display surface 220, 230: Fixing adhesive layer 240: Transparent protective layer 300: Touch panel module

Claims (4)

A conductive layer using a metal material as a conductive substance;
A pressure-sensitive adhesive layer in contact with the conductive layer,
The pressure-sensitive adhesive layer includes an acrylic copolymer having a hydrophilic acrylic monomer containing at least one hydrophilic group selected from the group consisting of a hydroxyl group, an alkoxy group, an amino group, and an amide group as a copolymerization monomer component; And at least one migration inhibitor selected from the group consisting of a moisture absorbent and a metal ion scavenger,
The transparent conductive sheet, wherein a blending ratio of the hydrophilic acrylic monomer in the copolymerization monomer component of the acrylic copolymer is 15% by mass or more of the total weight of the acrylic copolymer.   The transparent conductive sheet according to claim 1, wherein at least the moisture absorbent is used as the migration inhibitor. A conductive layer using a metal material as a conductive substance;
A pressure-sensitive adhesive layer in contact with the conductive layer,
The pressure-sensitive adhesive layer includes an acrylic copolymer having a hydrophilic acrylic monomer containing at least one hydrophilic group selected from the group consisting of a hydroxyl group, an alkoxy group, an amino group, and an amide group as a copolymerization monomer component; And at least one migration inhibitor selected from the group consisting of a moisture absorbent and a metal ion scavenger,
The touch panel module, wherein a blending ratio of the hydrophilic acrylic monomer in a copolymerization monomer component of the acrylic copolymer is 15% by mass or more of a total weight of the acrylic copolymer. An image display device;
Provided on the image display surface side of the image display device, comprising at least a conductive layer using a metal material as a conductive substance and an adhesive layer in contact with the conductive layer,
The pressure-sensitive adhesive layer includes an acrylic copolymer having a hydrophilic acrylic monomer containing at least one hydrophilic group selected from the group consisting of a hydroxyl group, an alkoxy group, an amino group, and an amide group as a copolymerization monomer component; And at least one migration inhibitor selected from the group consisting of a moisture absorbent and a metal ion scavenger,
The touch panel device, wherein a blending ratio of the hydrophilic acrylic monomer in a copolymerization monomer component of the acrylic copolymer is 15% by mass or more of a total weight of the acrylic copolymer.

Images