WO2013047556A1 - Touch panel and method for producing touch panel - Google Patents

Abstract

In the present invention, a touch panel is provided with: a plurality of first transparent electroconductive patterns extending in a first direction; a plurality of second transparent electroconductive patterns extending in a second direction orthogonal to the first direction; a plurality of first peripheral wirings electrically connected to each of the first transparent electroconductive patterns; and a plurality of second peripheral wirings electrically connected to each of the second transparent electroconductive patterns. The first and second peripheral wirings and the first and second transparent electroconductive patterns are electrically connected via a U-shaped insulating film which opens on one end. The first and second transparent electroconductive patterns cover all of the first and second peripheral wirings which are not covered by the insulating film. Provided thereby is a touch panel making it possible to achieve favorable contact (conduction) with the peripheral wirings even in a contact region in which is interposed a through-hole formed in the insulating film, and making it possible to prevent corrosion of the peripheral wirings.

Description

Touch panel and method for manufacturing touch panel

The present invention relates to a touch panel and a touch panel manufacturing method, and more particularly, to a touch panel technology to which a transparent conductive pattern including a binder and conductive fibers is applied.

In recent years, touch panels have attracted attention. The touch panel is mainly applied to a small size such as a PDA (personal digital assistant) or a mobile phone, but it is considered that the touch panel will be increased in size by being applied to a display for a personal computer.

ITO (Indium Tin Oxide) is used as the transparent electrode of the touch panel. However, indium, which is a raw material of ITO, is expensive and has a limit to stable supply, a manufacturing process is high because a vacuum process is required for thin film production, and an ITO film is brittle and inferior in bending resistance. There are challenges.

Therefore, it has been studied to use a transparent conductive film containing fine metal wires (conductive fibers) as the transparent electrode of the touch panel. Patent Document 1 discloses that a transparent conductive film having both high conductivity and good transparency produced by transferring a transparent conductive fiber layer onto a transparent film substrate is suitably used for a touch panel or the like.

JP 2009-231029

In an electronic device such as a touch panel, electrode wirings are electrically connected through a through hole formed in an insulating film. However, in the case of the method described in Patent Document 1, there is a problem in that contact between the electrode wirings is insufficient in the contact region, and contact cannot be obtained, resulting in poor conduction.

The present invention has been made in consideration of such problems. Even when the transparent conductive film is formed by transfer, sufficient contact with the peripheral wiring can be achieved even in the contact region through the through-hole formed in the insulating film, and good contact (conduction) with the peripheral wiring can be achieved. An object is to provide a touch panel that can prevent corrosion of peripheral wiring.

The touch panel according to an aspect of the present invention includes a transparent substrate, a plurality of first transparent conductive patterns formed along the first direction on the transparent substrate, and including a binder and conductive fibers, and the transparent A plurality of second transparent conductive patterns formed on a substrate along a second direction orthogonal to the first direction and including a binder and conductive fibers; and each of the second transparent conductive patterns formed on the transparent substrate. A plurality of first peripheral wirings electrically connected to the end portions of one transparent conductive pattern, and a plurality of second peripheral lines formed on the transparent substrate and electrically connected to the end portions of the second transparent conductive patterns A first connection structure that connects the wiring, the first transparent conductive pattern and the first peripheral wiring, and a second connection structure that connects the second transparent conductive pattern and the second peripheral wiring. The first connection structure includes A first peripheral wiring, a U-shaped first insulating film formed on the first peripheral wiring and having an opening for exposing a part of the first peripheral wiring; and the exposed first peripheral wiring. The first transparent conductive pattern is provided, and the ratio of the film thickness of the first insulating film to the opening length of the first insulating film (opening length of the first insulating film / film thickness of the first insulating film) is 25 or more. It is.

In the touch panel according to an aspect of the present invention, preferably, the second connection structure is formed on the second peripheral wiring and the second peripheral wiring to expose a part of the second peripheral wiring. And a second transparent conductive pattern covering the exposed second peripheral wiring, and the film thickness of the second insulating film and the opening of the second insulating film. The ratio to the length (opening length of the second insulating film / film thickness of the second insulating film) is 25 or more.

Preferably, the ratio of the thickness of the first transparent conductive pattern to the thickness of the first insulating film (the thickness of the first insulating layer / the thickness of the first transparent conductive pattern) is 5 or more and 20 or less, And / or the ratio of the thickness of the second transparent conductive pattern to the thickness of the second insulating film (the thickness of the second insulating layer / the thickness of the second transparent conductive pattern) is 5 or more and 20 or less.

Preferably, the conductive fiber is a silver nanowire.

Preferably, the first peripheral wiring and the second peripheral wiring are made of a metal film.

Preferably, the conductive fiber has a minor axis of 50 nm or less.

According to another aspect of the present invention, a method for manufacturing a touch panel includes a step of forming a plurality of first peripheral wirings and a plurality of second peripheral wirings on a transparent substrate, and the first peripheral wirings on the first peripheral wirings. A U-shaped first insulating film having an opening for exposing a part of the peripheral wiring and / or a U having an opening for exposing a part of the second peripheral wiring on each of the second peripheral wirings. Forming a second insulating film having a letter shape, forming a conductive layer including a binder and conductive fibers on a transfer substrate, and forming the conductive layer on the transfer substrate on the transparent substrate. Transferring, covering the exposed portion of the first peripheral wiring and / or the second peripheral wiring, and electrically connecting the first peripheral wiring and the second peripheral wiring to the conductive layer; A plurality of first transparent conductive patterns extending in the first direction by patterning the conductive layer; And a step of forming a plurality of second transparent conductive patterns extending in a second direction perpendicular to the first direction.

Preferably, when the conductive layer on the transfer base material is transferred onto the transparent substrate, the transparent substrate has a temperature range of 90 ° C. or more and 120 ° C. or less.

Preferably, when the conductive layer on the transfer base material is transferred onto the transparent substrate, the transfer pressure is in the range of 0.4 MPa to 0.8 MPa.

According to the present invention, even when the transparent conductive film is formed by transfer, sufficient contact with the peripheral wiring can be achieved in the contact region, so that good contact (conduction) between the peripheral wiring and the transparent conductive film can be formed. Further, corrosion of peripheral wiring can be prevented.

The top view which shows the touch panel by this embodiment typically Plan view of contact area including peripheral wiring and insulating film Sectional drawing along the AA line in the top view shown to FIG. 2A Plan view of contact area including peripheral wiring, insulating film, and transparent conductive pattern Sectional drawing along the BB line in the top view shown to FIG. 3A Schematic showing an example of conductive layer transfer material Schematic showing another example of conductive layer transfer material Explanatory drawing explaining the transfer method using a conductive layer transfer material (the 1) Explanatory drawing explaining the transfer method using a conductive layer transfer material (the 2) Explanatory drawing explaining the transfer method using a conductive layer transfer material (the 3) Schematic diagram showing multiple connection structures (Part 1) Schematic showing multiple connection structures (part 2) Schematic showing multiple connection structures (Part 3) Schematic showing another connection structure (part 1) Schematic showing another connection structure (part 2) Table showing manufacturing conditions and evaluation results

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The present invention will be described by the following preferred embodiments, but can be modified in many ways without departing from the scope of the present invention, and other embodiments than the present embodiment are utilized. be able to. Accordingly, all modifications within the scope of the present invention are included in the claims.

Hereinafter, the wiring structure and the touch panel according to the present embodiment will be described with reference to FIGS. 1 to 3B.

The touch panel 10 includes a transparent substrate 20, a plurality of first transparent conductive patterns 30 and a plurality of second transparent conductive patterns 40 formed on the transparent substrate 20. Each first transparent conductive pattern 30 is disposed along a first direction, and each second transparent conductive pattern 40 is disposed along a second direction orthogonal to the first direction.

The first transparent conductive pattern 30 includes a plurality of first sensing units 32 and a first connection unit 34 that electrically connects the plurality of first sensing units 32. The first sensing part 32 has a wide rhombus shape, and the first connection part 34 has a narrow strip shape. With respect to the first transparent conductive pattern 30, the first sensing part 32 and the first connection part 34 are integrally formed.

The second transparent conductive pattern 40 includes a plurality of second sensing units 42 and a second connection unit 44 that electrically connects the plurality of second sensing units 42. The second sensing part 42 has a wide rhombus shape, and the second connection part 44 has a narrow strip shape. The second connection portion 44 is formed on the insulating film 50 formed on the first connection portion 34. That is, an insulating film 50 having substantially the same shape as the first connection portion 34 is formed on the first connection portion 34 having a strip shape, and the strip-shaped first connection portion having a narrower width than the insulating film 50 is formed on the insulation film 50. Two connecting portions 44 are formed. Regarding the second transparent conductive pattern 40, the second sensing part 42 and the second connection part 44 are formed as separate bodies. The insulating film 50 is required to be transparent. Therefore, as a material of the insulating film 50, the inorganic _{materials, SiO 2, SiOx, SiNx,} SiOxNy (X, Y each is an arbitrary integer), as the organic material, acrylic resin or the like.

The first transparent conductive pattern 30 and the second transparent conductive pattern 40 are arranged so that the first sensing unit 32 and the second sensing unit 42 do not overlap in plan view. On the other hand, the 1st connection part 34 and the 2nd connection part 44 are arrange | positioned so that it may cross | intersect by planar view. However, the first connection portion 34 and the second connection portion 44 are electrically separated by the insulating film 50.

By arranging the first transparent conductive pattern 30 and the second transparent conductive pattern 40 as described above, a so-called regularly arranged diamond pattern is configured. Each of the first transparent conductive pattern 30 and the second transparent conductive pattern 40 is composed of a transparent conductive film containing conductive fibers and a binder.

The structure of the conductive fiber is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably a solid structure or a hollow structure. Here, the solid structure fiber may be referred to as a wire, and the hollow structure fiber may be referred to as a tube.

A conductive fiber having an average minor axis length of 5 nm to 1,000 nm and an average major axis length of 1 μm to 100 μm may be referred to as “nanowire”.

In addition, a conductive fiber having an average minor axis length of 1 nm to 1,000 nm and an average major axis length of 0.1 μm to 1,000 μm and having a hollow structure may be referred to as “nanotube”.

The material of the conductive fiber is not particularly limited as long as it has conductivity, and can be appropriately selected according to the purpose, but is preferably at least one of metal and carbon. Among these, the conductive fiber is preferably at least one of metal nanowires, metal nanotubes, and carbon nanotubes.

From the viewpoint of transparency and haze, the average minor axis length is preferably 50 nm or less.

The binder is an organic high molecular polymer, and at least one group that promotes alkali solubility in a molecule (preferably a molecule having an acrylic copolymer as a main chain) (for example, a carboxyl group, a phosphate group, It can be appropriately selected from alkali-soluble resins having a sulfonic acid group or the like.

As a material of the transparent substrate 20, for example, a transparent glass substrate such as non-alkali glass or soda glass, or a transparent synthetic resin substrate such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PES (polyether sulfone), or the like Can be used. From the viewpoint of transparency and dimensional stability, it is preferable to use alkali-free glass or PET.

The sensor area S is formed on the transparent substrate 20 by the plurality of first transparent conductive patterns 30 and the plurality of second transparent conductive patterns 40. A plurality of first peripheral wirings 60 and a plurality of second peripheral wirings 70 are formed in the outer peripheral region of the sensor area S on the transparent substrate 20. The first peripheral wiring 60 is electrically connected to one end of the first transparent conductive pattern 30 at one end thereof. The first peripheral wiring 60 is electrically connected to an external connection terminal (not shown) at the other end. The first peripheral wiring 60 includes a narrow line portion 60a, a pad portion 60b wider than the line portion 60a at one end, and a pad 60c wider than the line portion 60a at the other end.

The second peripheral wiring 70 is electrically connected to one end of the second transparent conductive pattern 40 at one end thereof. The second peripheral wiring 70 is electrically connected to an external connection terminal (not shown) at the other end. The second peripheral wiring 70 includes a narrow line portion 70a, a pad portion 70b that is wider than the line portion 70a at one end, and a pad 70c that is wider than the line portion 70a at the other end.

The first peripheral wiring 60 and the second peripheral wiring 70 are made of a metal film. The metal film is made of, for example, a material such as Al, Ag, Cu, Mo, Ti, Cr, or an alloy thereof. The metal film may be composed of a laminated film of a plurality of materials. For example, a laminated film made of Mo (or Mo alloy) / Al (or Al alloy) / Mo (or Mo alloy) may be used.

The first transparent conductive pattern 30 includes a wide connection portion 36 that is electrically connected to the pad portion 60b at one end thereof. The connecting portion 36 is electrically connected to the pad portion 60b through a U-shaped insulating film 38.

The second transparent conductive pattern 40 includes a wide connection portion 46 that is electrically connected to the pad portion 70b at one end thereof. The connecting portion 46 is electrically connected to the pad portion 70b through a U-shaped insulating film 48.

FIG. 2A is an enlarged plan view showing the pad portion 60b (70b) and the insulating film 38 (48) in the contact region. FIG. 2B is a cross-sectional view along the line AA. On a transparent substrate (not shown), a narrow line portion 60a (70a) and a pad portion 60b (70b) wider than the line portion 60a (70a) are formed at one end of the line portion 60a (70a). Is done. A U-shaped insulating film 38 (48) having an opening for exposing part of the pad portion 60b (70b) is formed on the pad portion 60b (70b). In the present embodiment, the contact hole for connecting the upper and lower wirings is formed of a U-shaped insulating film 38 (48) that is open in plan view. On the other hand, a normal contact hole is formed of an insulating film that surrounds the entire periphery in plan view. In the present embodiment, the shape of the insulating film is different from the conventional one.

The U-shaped insulating film 38 (48) has a predetermined opening length L (distance between the opposing insulating films 38). The U-shaped insulating film 38 (48) has a predetermined film thickness t1.

FIG. 3A is an enlarged plan view showing the pad portion 60b (70b), the insulating film 38 (48), and the connection portion 36 (46) in the contact region. 3B is a cross-sectional view taken along the line BB in FIG. 3A. The connecting portion 36 (48) is formed so as to cover all of the pad portion 60b (70b) exposed from the opening of the U-shaped insulating film 38 (48).

As shown in FIG. 3B, one side of the U-shaped insulating film 38 (48) is open, so that the connection portion 36 (46) and the pad portion 60b (70b) are reliably electrically connected ( Contacted).

According to the connection structure of the present embodiment, even when the transparent conductive film (connection portions 36 and 46) is formed by transfer, the insulating film 38 (48) has a U-shape that opens one side. The transparent conductive film (connection portions 36, 46) and the peripheral wiring ( pad portions 60b, 70b) can be reliably electrically connected (contacted).

Further, the transparent conductive film (connection portions 36 and 46) is formed so as to cover all exposed portions of the peripheral wiring ( pad portions 60b and 70b). As a result, corrosion of peripheral wiring can be prevented.

Furthermore, the ratio of the thickness t1 of the insulating film 38 (48) to the opening length L of the insulating film 38 (48) (the opening length L of the insulating film / the thickness t1 of the insulating film) needs to be 25 or more. is there. By setting this range, the peripheral wiring can be reliably electrically connected (contacted) without disconnecting the transparent conductive film containing the conductive fibers and the binder.

A preferable insulating film thickness t1 is 0.2 μm or more and 3.0 μm or less, and an opening length L is preferably 50 μm or more.

Further, when the thickness t2 of the connecting portion 36 (46) is set, the ratio of the thickness t2 of the connecting portion 36 (46) and the thickness t1 of the insulating film 38 (48) (thickness t1 / insulating thickness of the connecting portion). The film thickness t2) is preferably 5 or more and 20 or less. By setting it within this range, insulation other than the connection portion is good, and the peripheral wiring is reliably electrically connected (contacted) without disconnecting the transparent conductive film containing the conductive fiber and the binder. be able to.

<Transparent conductive film>
The transparent conductive film contains at least a binder and conductive fibers. The binder is not particularly limited, but preferably contains a photosensitive compound and, if necessary, other components.

[Conductive fiber]
The material of the conductive fiber is not particularly limited as long as it has conductivity, and can be appropriately selected according to the purpose. It is preferable that it is at least any one of a metal and carbon, and among these, it is preferable that the said conductive fiber is at least any one of a metal nanowire, a metal nanotube, and a carbon nanotube.

<< Metal nanowires >>
-material-
There is no restriction | limiting in particular as a material of the said metal nanowire, According to the objective, it can select suitably.

-metal-
Examples of the metal include copper, silver, gold, platinum, palladium, nickel, tin, cobalt, rhodium, iridium, iron, ruthenium, osmium, manganese, molybdenum, tungsten, niobium, tantalum, titanium, bismuth, antimony, and lead. Or alloys thereof. Among these, silver and an alloy with silver are preferable in terms of excellent conductivity.

Examples of the metal used in the alloy with silver include gold, platinum, osmium, palladium, iridium and the like. These may be used alone or in combination of two or more.

-shape-
There is no restriction | limiting in particular as a shape of the said metal nanowire. It can be appropriately selected depending on the purpose, and can take any shape such as a columnar shape, a rectangular parallelepiped shape, or a columnar shape with a polygonal cross section. In applications where high transparency is required, a cylindrical shape or a cross-sectional shape with rounded polygonal corners is preferable.

The cross-sectional shape of the metal nanowire can be examined by applying a metal nanowire aqueous dispersion on a substrate and observing the cross-section with a transmission electron microscope (TEM).

-Average minor axis length and average major axis length-
The average minor axis length of the metal nanowire (sometimes referred to as “average minor axis diameter” or “average diameter”) is preferably 1 nm to 50 nm, more preferably 10 nm to 40 nm, and even more preferably 15 nm to 35 nm. .

When the average minor axis length is less than 1 nm, the oxidation resistance may be deteriorated and the durability may be deteriorated. When the average minor axis length is more than 50 nm, scattering due to metal nanowires occurs and sufficient transparency is obtained. There are times when you can't.

The average minor axis length of the metal nanowires was determined by observing 300 metal nanowires using a transmission electron microscope (TEM; manufactured by JEOL Ltd., JEM-2000FX). The average minor axis length was determined. In addition, the shortest axis length when the short axis of the metal nanowire is not circular is the shortest axis.

The average major axis length (sometimes referred to as “average length”) of the metal nanowire is preferably 1 μm to 50 μm, more preferably 5 μm to 45 μm, and even more preferably 10 μm to 40 μm.

If the average major axis length is less than 1 μm, it may be difficult to form a dense network and sufficient conductivity may not be obtained. If the average major axis length exceeds 50 μm, the metal nanowires are too long and manufactured. Sometimes entangled and agglomerates may occur during the manufacturing process.

The average major axis length of the metal nanowire is, for example, observed with 300 metal nanowires using a transmission electron microscope (TEM; manufactured by JEOL Ltd., JEM-2000FX). The average major axis length was determined. In addition, when the said metal nanowire was bent, the circle | round | yen which makes it an arc was considered and the value calculated from the radius and curvature was made into the major axis length.

-Production method-
There is no restriction | limiting in particular as a manufacturing method of the said metal nanowire, Although it may manufacture by what kind of method, a metal ion is reduce | restored, heating in the solvent which melt | dissolved the halogen compound and the dispersion additive as follows. It is preferable to manufacture by.

In addition, as a method for producing metal nanowires, JP2009-215594A, JP2009-242880A, JP2009-299162A, JP2010-84173A, and JP2010-86714A are disclosed. Etc. can be used.

<< Metal Nanotubes >>
-material-
There is no restriction | limiting in particular as a material of the said metal nanotube, What kind of metal may be sufficient, For example, the material of the above-mentioned metal nanowire etc. can be used.

-shape-
The shape of the metal nanotube may be a single layer or a multilayer, but a single layer is preferable from the viewpoint of excellent conductivity and thermal conductivity.

-Average minor axis length, average major axis length, thickness-
The thickness of the metal nanotube (difference between the outer diameter and the inner diameter) is preferably 3 nm to 80 nm, and more preferably 3 nm to 30 nm.

When the thickness is less than 3 nm, the oxidation resistance is deteriorated and the durability may be deteriorated. When the thickness is more than 80 nm, scattering due to the metal nanotube may occur.

The average major axis length of the metal nanotubes is preferably 1 μm to 40 μm, more preferably 3 μm to 35 μm, still more preferably 5 μm to 30 μm.

<< Carbon nanotube >>
The carbon nanotube (CNT) is a substance in which a graphite-like carbon atomic surface (graphene sheet) is a single-layer or multilayer coaxial tube. The single-walled carbon nanotubes are called single-walled nanotubes (SWNT), the multi-walled carbon nanotubes are called multi-walled nanotubes (MWNT), and the double-walled carbon nanotubes are also called double-walled nanotubes (DWNT). In the conductive fiber used in the present invention, the carbon nanotube may be a single wall or a multilayer, but a single wall is preferable from the viewpoint of excellent conductivity and thermal conductivity.

-aspect ratio-
The aspect ratio of the conductive fiber is preferably 10 or more. The aspect ratio generally means the ratio between the long side and the short side of a fibrous material (ratio of average major axis length / average minor axis length).

The method for measuring the aspect ratio is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method for measuring with an electron microscope.

When measuring the aspect ratio of the conductive fiber with an electron microscope, it is only necessary to confirm whether the aspect ratio of the conductive fiber is 10 or more with one field of view of the electron microscope. In addition, the aspect ratio of the entire conductive fiber can be estimated by measuring the major axis length and the minor axis length of the conductive fiber separately.

In the case where the conductive fiber is in a tube shape, the outer diameter of the tube is used as the diameter for calculating the aspect ratio.

The aspect ratio of the conductive fiber is not particularly limited as long as it is 10 or more, and can be appropriately selected according to the purpose, but is preferably 50 to 1,000,000, preferably 100 to 1,000,000. More preferred.

When the aspect ratio is less than 10, network formation by the conductive fibers may not be performed and sufficient conductivity may not be obtained. When the aspect ratio exceeds 1,000,000, the conductive fibers may be formed or handled thereafter. In this case, since the conductive fibers are entangled and aggregate before film formation, a stable liquid may not be obtained.

-Ratio of conductive fibers with an aspect ratio of 10 or more-
The ratio of the conductive fibers having an aspect ratio of 10 or more is preferably 50% or more, more preferably 60% or more, and particularly preferably 75% or more in volume ratio in the total conductive composition. Hereinafter, the ratio of these conductive fibers may be referred to as “the ratio of conductive fibers”.

If the ratio of the conductive fibers is less than 50%, the conductive material contributing to the conductivity may decrease and the conductivity may decrease. At the same time, a voltage concentration may occur because a dense network cannot be formed. , Durability may be reduced. In addition, particles having a shape other than the conductive fiber are not preferable because they do not greatly contribute to conductivity and have absorption. In particular, in the case of metal, transparency may be deteriorated when plasmon absorption such as a spherical shape is strong.

Here, the ratio of the conductive fibers is, for example, when the conductive fibers are silver nanowires, the silver nanowire aqueous dispersion is filtered to separate the silver nanowires from the other particles. The ratio of the conductive fibers can be determined by measuring the amount of silver remaining on the filter paper and the amount of silver that has passed through the filter paper using an ICP emission analyzer. By observing the conductive fibers remaining on the filter paper with a TEM, observing the short axis lengths of 300 conductive fibers and examining their distribution, the short axis length is 200 nm or less and the long axis length is It confirms that it is an electroconductive fiber whose length is 1 micrometer or more. Note that the filter paper has a short axis length of 200 nm or less in the TEM image and the longest axis of particles other than conductive fibers having a long axis length of 1 μm or more is measured, and is at least twice the longest axis. And it is preferable to use the thing of the length below the shortest length of the long axis of an electroconductive fiber.

Here, the average minor axis length and the average major axis length of the conductive fiber can be obtained by observing a TEM image or an optical microscope image using, for example, a transmission electron microscope (TEM) or an optical microscope. In the present invention, the average minor axis length and the average major axis length of the conductive fibers are obtained by observing 300 conductive fibers with a transmission electron microscope (TEM) and obtaining the average value. is there.

The conductive layer containing conductive fibers and a binder (photosensitive resin) in one layer is described below, but the photosensitive layer (patterning material) containing the photosensitive resin is not necessarily integrated with the conductive layer containing conductive fibers. The conductive layer and the photosensitive layer (patterning layer) may be laminated, or the photosensitive layer (patterning layer) may be laminated and transferred after the conductive layer is transferred to the transfer target, or the resist material may be printed. A patterning mask may be formed.

<< Binder >>
The binder is an organic high molecular polymer, and at least one group (for example, carboxyl group, phosphate group) that promotes alkali solubility in a molecule (preferably a molecule having an acrylic copolymer as a main chain). , Sulfonic acid groups, etc.) can be selected appropriately from alkali-soluble resins.

Among these, those that are soluble in an organic solvent and that can be developed with a weak alkaline aqueous solution are preferable, and those that have an acid-dissociable group and become alkali-soluble when the acid-dissociable group is dissociated by the action of an acid. Particularly preferred.

Here, the acid dissociable group represents a functional group capable of dissociating in the presence of an acid.

For the production of the binder, for example, a known radical polymerization method can be applied. Polymerization conditions such as temperature, pressure, type and amount of radical initiator, type of solvent, etc. when producing an alkali-soluble resin by the radical polymerization method can be easily set by those skilled in the art, and the conditions are determined experimentally. Can be determined.

The organic polymer is preferably a polymer having a carboxylic acid in the side chain (photosensitive resin having an acidic group).

Examples of the polymer having a carboxylic acid in the side chain include, for example, JP-A-59-44615, JP-B-54-34327, JP-B-58-12777, JP-B-54-25957, JP-A-59-53836, As described in JP-A-59-71048, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer, maleic acid copolymer, partial ester A maleic acid copolymer, etc., an acidic cellulose derivative having a carboxylic acid in the side chain, a polymer having a hydroxyl group with an acid anhydride added, and a polymer having a (meth) acryloyl group in the side chain Polymers are also preferred.

Among these, benzyl (meth) acrylate / (meth) acrylic acid copolymers and multi-component copolymers composed of benzyl (meth) acrylate / (meth) acrylic acid / other monomers are particularly preferable.

Furthermore, a high molecular polymer having a (meth) acryloyl group in the side chain and a multi-component copolymer composed of (meth) acrylic acid / glycidyl (meth) acrylate / other monomers are also useful. The polymer can be used by mixing in an arbitrary amount.

In addition to the above, 2-hydroxypropyl (meth) acrylate / polystyrene macromonomer / benzyl methacrylate / methacrylic acid copolymer, 2-hydroxy-3-phenoxypropyl acrylate / polymethyl described in JP-A-7-140654 Methacrylate macromonomer / benzyl methacrylate / methacrylic acid copolymer, 2-hydroxyethyl methacrylate / polystyrene macromonomer / methyl methacrylate / methacrylic acid copolymer, 2-hydroxyethyl methacrylate / polystyrene macromonomer / benzyl methacrylate / methacrylic acid copolymer , Etc.

As the specific structural unit in the alkali-soluble resin, (meth) acrylic acid and other monomers copolymerizable with the (meth) acrylic acid are suitable.

Examples of other monomers copolymerizable with the (meth) acrylic acid include alkyl (meth) acrylates, aryl (meth) acrylates, and vinyl compounds. In these, the hydrogen atom of the alkyl group and aryl group may be substituted with a substituent.

Examples of the alkyl (meth) acrylate or aryl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and pentyl (meth). Acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, tolyl (meth) acrylate, naphthyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meta ) Acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and the like. These may be used individually by 1 type and may use 2 or more types together.

Examples of the vinyl compound include styrene, α-methylstyrene, vinyl toluene, glycidyl methacrylate, acrylonitrile, vinyl acetate, N-vinyl pyrrolidone, tetrahydrofurfuryl methacrylate, polystyrene macromonomer, polymethyl methacrylate macromonomer, CH ₂ ═CR. ₁ R ₂ , CH ₂ ═C (R ₁ ) (COOR ₃ ) [wherein R ₁ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ₂ represents an aromatic hydrocarbon ring having 6 to 10 carbon atoms. R ₃ represents an alkyl group having 1 to 8 carbon atoms or an aralkyl group having 6 to 12 carbon atoms. ] And the like. These may be used individually by 1 type and may use 2 or more types together.

The weight average molecular weight of the binder is preferably from 1,000 to 500,000, more preferably from 3,000 to 300,000, and even more preferably from 5,000 to 200,000, from the viewpoints of alkali dissolution rate, film physical properties and the like. .

Here, the weight average molecular weight is measured by gel permeation chromatography and can be determined using a standard polystyrene calibration curve.

The content of the binder is preferably 40% by mass to 95% by mass with respect to the entire conductive layer, more preferably 50% by mass to 90% by mass, and still more preferably 70% by mass to 90% by mass. When the content is in the range, both developability and conductivity of the metal nanowire can be achieved.

-Photosensitive compounds-
The said photosensitive compound means the compound which provides the function which forms an image by exposure, or gives the trigger to it. Specific examples include (1) a compound that generates acid upon exposure (photoacid generator), (2) a photosensitive quinonediazide compound, and (3) a photoradical generator. These may be used individually by 1 type and may use 2 or more types together. Moreover, a sensitizer etc. can also be used together for sensitivity adjustment.

-(1) Photoacid generator--
(1) As the photoacid generator, a photoinitiator for photocationic polymerization, a photoinitiator for radical photopolymerization, a photodecolorant for dyes, a photochromic agent, an actinic ray used for a micro resist, etc. Alternatively, known compounds that generate an acid upon irradiation with radiation and a mixture thereof can be appropriately selected and used.

The (1) photoacid generator is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, Examples include disulfone and o-nitrobenzyl sulfonate. Among these, imide sulfonate, oxime sulfonate, and o-nitrobenzyl sulfonate, which are compounds that generate sulfonic acid, are particularly preferable.

Further, a group capable of generating an acid upon irradiation with actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the resin, such as US Pat. No. 3,849,137, German Patent No. 3914407. Description, JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853 The compounds described in JP-A-63-146029, etc. can be used.

Furthermore, compounds that generate an acid by light described in each specification such as US Pat. No. 3,779,778 and European Patent 126,712 can also be used.

-(2) Quinonediazide compound--
The (2) quinonediazide compound can be obtained, for example, by subjecting 1,2-quinonediazidesulfonyl chlorides, hydroxy compounds, amino compounds and the like to a condensation reaction in the presence of a dehydrochlorinating agent.

The blending amount of the (1) photoacid generator and the (2) quinonediazide compound is based on the difference in dissolution rate between the exposed part and the unexposed part, and the allowable range of sensitivity, with respect to 100 parts by weight of the total amount of the binder. The amount is preferably 1 to 100 parts by weight, more preferably 3 to 80 parts by weight.

The (1) photoacid generator and the (2) quinonediazide compound may be used in combination.

In the present invention, among the above (1) photoacid generators, compounds that generate sulfonic acid are preferable, and the following oxime sulfonate compounds are particularly preferable from the viewpoint of high sensitivity.

When a compound having a 1,2-naphthoquinonediazide group is used as the (2) quinonediazide compound, high sensitivity and good developability are obtained.

Among the above (2) quinonediazide compounds, the following compounds in which D is independently a hydrogen atom or a 1,2-naphthoquinonediazide group are preferred from the viewpoint of high sensitivity.

--- (3) Photoradical generator--
The photoradical generator has a function of directly absorbing light or being photosensitized to cause a decomposition reaction or a hydrogen abstraction reaction to generate a polymerization active radical. The photo radical generator is preferably one having absorption in a wavelength region of 300 nm to 500 nm.

The photo radical generator may be used alone or in combination of two or more. The content of the photo radical generator is preferably 0.1% by mass to 50% by mass and more preferably 0.5% by mass to 30% by mass with respect to the total solid content of the coating liquid for the transparent conductive film. Preferably, 1% by mass to 20% by mass is more preferable. In the numerical range, good sensitivity and pattern formability can be obtained.

The photo radical generator is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a group of compounds described in JP-A-2008-268884. Among these, triazine compounds, acetophenone compounds, acylphosphine (oxide) compounds, oxime compounds, imidazole compounds, and benzophenone compounds are particularly preferable from the viewpoint of exposure sensitivity.

As the photo radical generator, from the viewpoint of exposure sensitivity and transparency, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1 -Butanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, , 2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, N, N-diethylaminobenzophenone, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (o-benzoyloxime)] is preferred.

The coating liquid for the transparent conductive film may be used in combination with a photoradical generator and a chain transfer agent in order to improve exposure sensitivity.

Examples of the chain transfer agent include N, N-dialkylaminobenzoic acid alkyl esters such as N, N-dimethylaminobenzoic acid ethyl ester, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzoimidazole, Heterocycles such as N-phenylmercaptobenzimidazole, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione Mercapto compounds having an aliphatic polyfunctional mercapto compound such as pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptobutyrate), 1,4-bis (3-mercaptobutyryloxy) butane, etc. Is mentioned. These may be used individually by 1 type and may use 2 or more types together.

The content of the chain transfer agent is preferably 0.01% by mass to 15% by mass, more preferably 0.1% by mass to 10% by mass, based on the total solid content of the coating liquid for the transparent conductive film. More preferably, the content is 5 to 5% by mass.

-Other ingredients-
Examples of the other components include various additives such as a crosslinking agent, a dispersing agent, a solvent, a surfactant, an antioxidant, an antisulfurizing agent, a metal corrosion inhibitor, a viscosity modifier, and an antiseptic.

-Crosslinking agent-
The crosslinking agent is a compound that forms a chemical bond by free radical or acid and heat to cure the conductive layer, and is substituted with at least one group selected from, for example, a methylol group, an alkoxymethyl group, and an acyloxymethyl group. Melamine compounds, guanamine compounds, glycoluril compounds, urea compounds, phenol compounds or phenol ether compounds, epoxy compounds, oxetane compounds, thioepoxy compounds, isocyanate compounds, or azide compounds; methacryloyl groups or And compounds having an ethylenically unsaturated group containing an acryloyl group. Among these, an epoxy compound, an oxetane compound, and a compound having an ethylenically unsaturated group are particularly preferable in terms of film properties, heat resistance, and solvent resistance.

The oxetane resin can be used alone or in combination with an epoxy resin. In particular, when used in combination with an epoxy resin, the reactivity is high, which is preferable from the viewpoint of improving film properties.

The content of the crosslinking agent is preferably 1 part by weight to 250 parts by weight, and more preferably 3 parts by weight to 200 parts by weight with respect to 100 parts by weight of the total amount of the binder.

-Dispersant-
The dispersant is used for preventing and dispersing the conductive fibers. The dispersant is not particularly limited as long as the conductive fibers can be dispersed, and can be appropriately selected according to the purpose. For example, a commercially available low molecular pigment dispersant or polymer pigment dispersant can be used. In particular, a polymer dispersant having a property of adsorbing to conductive fibers is preferably used. For example, polyvinylpyrrolidone, BYK series (manufactured by Big Chemie), Solsperse series (manufactured by Nippon Lubrizol, etc.), Ajisper series ( Ajinomoto Co., Inc.).

The content of the dispersant is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 40 parts by weight, and more preferably 1 to 30 parts by weight with respect to 100 parts by weight of the binder. Particularly preferred.

When the content is less than 0.1 parts by mass, the conductive fibers may aggregate in the dispersion, and when it exceeds 50 parts by mass, a stable liquid film cannot be formed in the coating process. Application unevenness may occur.

--solvent--
The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, ethyl lactate , 3-methoxybutanol, water, 1-methoxy-2-propanol, isopropyl acetate, methyl lactate, N-methylpyrrolidone (NMP), γ-butyrolactone (GBL), propylene carbonate, and the like. These may be used individually by 1 type and may use 2 or more types together.

--- Metal corrosion inhibitor ---
There is no restriction | limiting in particular as said metal corrosion inhibitor, Although it can select suitably according to the objective, For example, thiols, azoles, etc. are suitable.

By containing the metal corrosion inhibitor, a further excellent rust prevention effect can be exhibited.

While the metal corrosion inhibitor is dissolved in the coating liquid for the transparent conductive film, it is added in a state dissolved in a suitable solvent, or powder, or after producing a conductive film with the coating liquid for the transparent conductive film described later, This can be applied by immersing in a metal corrosion inhibitor bath.

Next, a method for manufacturing a touch panel using a transfer method will be described with reference to FIGS. 4 to 6C.

(Conductive layer transfer material)
A conductive layer transfer material is used in the touch panel manufacturing method. A transfer base, a cushion layer for improving the transfer uniformity to the transfer target, and a conductive layer containing a binder and conductive fibers are provided in this order on the transfer base. The conductive layer transfer material preferably has an adhesion layer on the conductive layer, and has other layers such as an antifouling layer, a UV cut layer, and an antireflection layer as necessary. Also good. Moreover, in order to prevent a functional layer such as a conductive layer from being damaged or to prevent performance deterioration, an easily adhesive protective film may be laminated.

The conductive layer transfer material is not particularly limited in its shape, structure, size and the like as long as it has the above-described configuration, and can be appropriately selected according to the purpose. Examples of the structure include a single-layer structure and a laminated structure, and the size can be appropriately selected depending on the application and the like.

The conductive layer transfer material is flexible and preferably transparent, and the transparent includes colorless and transparent, colored transparent, translucent, colored translucent and the like.

Here, FIG. 4 is a schematic view showing an example of the conductive layer transfer material. The conductive layer transfer material 6 in FIG. 4 has a transfer base 1 and a cushion layer 2 and a conductive layer 3 in this order on one surface of the base.

FIG. 5 is a schematic view showing another example of the conductive layer transfer material. The conductive layer transfer material 7 in FIG. 5 is obtained by providing the adhesion layer 4 on the conductive layer 3 in the conductive layer transfer material 6 in FIG. 4.

In addition, although illustration is abbreviate | omitted, the conductive layer in the said conductive layer transfer material may be patterned, and does not need to be patterned. Examples of the patterning include electrode shapes applied with an existing ITO transparent conductive film. Specifically, stripe patterns and diamond patterns disclosed in WO 2005/114369 pamphlet, WO 2004/061808 pamphlet, JP 2010-33478 A, and JP 2010-44453 A are referred to. Etc.

The total average thickness A of the conductive layer and the cushion layer and the average thickness B of the transfer substrate satisfy the following formula: A / B = 0.01 to 0.7, and A / B = 0.02 to It is preferable to satisfy 0.6. If the A / B is less than 0.01, the transfer uniformity to the transfer medium may be lowered, and if it exceeds 0.7, the curl balance may be lost.

The average thickness of the transfer substrate is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 μm to 500 μm, more preferably 3 μm to 400 μm, and even more preferably 5 μm to 300 μm.

When the average thickness is less than 1 μm, it may be difficult to handle the conductive layer transfer material, and when it exceeds 500 μm, the rigidity of the transfer substrate may be increased, and transfer uniformity may be impaired.

The average thickness of the conductive layer is preferably 0.01 μm to 2 μm, and more preferably 0.03 μm to 1 μm. If the average thickness is less than 0.01 μm, the in-plane conductivity distribution may be non-uniform, and if it exceeds 2 μm, the transmittance may be lowered and the transparency may be impaired.

The average thickness of the cushion layer is preferably 1 μm to 50 μm, more preferably 1 μm to 30 μm, and even more preferably 5 μm to 20 μm. When the average thickness is less than 1 μm, transfer uniformity may be impaired, and when it exceeds 50 μm, the curl balance of the transfer material may be lowered.

Here, the average thickness of the transfer substrate, the average thickness of the conductive layer, and the average thickness of the cushion layer are embedded by, for example, SEM observation after taking out a cross section of the material by microtome cutting or by embedding with an epoxy resin. Then, it can be measured by TEM observation of a section prepared with a microtome. The average thickness of each of these layers is an average value measured at 10 points.

<Transfer substrate>
There is no restriction | limiting in particular about the shape, structure, size, etc. of the said transfer base material, According to the objective, it can select suitably, For example, a film form, a sheet form, etc. are mentioned as said shape. Examples of the structure include a single layer structure and a laminated structure. The size can be appropriately selected according to the application.

There is no restriction | limiting in particular as said transfer base material, According to the objective, it can select suitably, For example, a semiconductor substrate which has a transparent glass substrate, a synthetic resin sheet (film), a metal substrate, a ceramic board, a photoelectric conversion element. Etc. If necessary, the substrate can be subjected to pretreatment such as chemical treatment such as a silane coupling agent, plasma treatment, ion plating, sputtering, gas phase reaction method, vacuum deposition and the like.

Examples of the transparent glass substrate include white plate glass, blue plate glass, and silica-coated blue plate glass. Further, a thin glass substrate having a thickness of 10 μm to several hundred μm developed recently may be used.

Examples of the synthetic resin sheet include a polyethylene terephthalate (PET) sheet, a polycarbonate sheet, a triacetyl cellulose (TAC) sheet, a polyethersulfone sheet, a polyester sheet, an acrylic resin sheet, a vinyl chloride resin sheet, and an aromatic polyamide resin sheet. , Polyamideimide sheet, polyimide sheet and the like.

Examples of the metal substrate include an aluminum plate, a copper plate, a nickel plate, and a stainless plate.

The total visible light transmittance of the transfer substrate is preferably 70% or more, more preferably 85% or more, and still more preferably 90% or more. If the total visible light transmittance is less than 70%, the transmittance may be low and may cause a problem in practical use.

In the present invention, a transfer substrate that is colored to the extent that the object of the present invention is not hindered can also be used.

<Cushion layer>
There is no restriction | limiting in particular about the shape, structure, size, etc. of the said cushion layer, According to the objective, it can select suitably, For example, a film | membrane form, a sheet form, etc. are mentioned as said shape. Examples of the structure include a single layer structure and a laminated structure. The size can be appropriately selected according to the application.

The cushion layer is a layer that plays a role of improving transferability with the transfer target, and contains at least a polymer, and further contains other components as necessary.

-polymer-
The polymer is not particularly limited as long as it is a thermoplastic resin that softens when heated, and can be appropriately selected according to the purpose. For example, acrylic resin, styrene-acrylic copolymer, polyvinyl alcohol, polyethylene, ethylene-acetic acid Vinyl copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, polyvinyl chloride, gelatin; cellulose nitrate, cellulose triacetate, cellulose diacetate, cellulose acetate butyrate, cellulose acetate propionate, etc. Cellulose ester: Homopolymer or copolymer containing vinylidene chloride, vinyl chloride, styrene, acrylonitrile, vinyl acetate, alkyl (1 to 4 carbon atoms) acrylate, vinyl pyrrolidone, soluble polyester, polycarbonate Boneto, soluble polyamide. These may be used individually by 1 type and may use 2 or more types together.

The polymer used for the cushion layer is preferably a thermoplastic resin that is softened by heating. The glass transition temperature of the cushion layer is preferably 40 ° C to 150 ° C. If it is lower than 40 ° C., it may be too soft at room temperature to be inferior in handling properties, and if it is higher than 150 ° C., the cushion layer may not be softened by the heat laminating method and the transferability of the conductive layer may be inferior. Further, the glass transition temperature may be adjusted by adding a plasticizer or the like.

Examples of the other components include organic polymer materials described in paragraph [0007] and subsequent paragraphs of JP-A-5-72724, various plasticizers for adjusting adhesive force with the transfer substrate, supercooling materials, Examples thereof include adhesion improvers, surfactants, mold release agents, thermal polymerization inhibitors, and solvents.

The cushion layer can be formed by applying a coating solution for the cushion layer containing the polymer and, if necessary, the other components, onto a transfer substrate and drying it.

The other components are not particularly limited and may be appropriately selected depending on the intended purpose. For example, fillers, surfactants, antioxidants, sulfurization inhibitors, metal corrosion inhibitors, viscosity modifiers, preservatives And various other additives.

The cushion layer can be formed by applying a coating solution for the cushion layer containing the polymer and, if necessary, the other components, onto a base material and drying it.

The coating method is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a roll coating method, a dip coating method, a spin coating method, a casting method, a die coating method, a blade coating method, a bar coating method, a gravure method Examples thereof include a coating method, a curtain coating method, a spray coating method, and a doctor coating method.

Here, FIGS. 6A to 6C are diagrams showing an example of a transfer method using the conductive layer transfer material 6 of the present invention.

FIG. 6A shows a transfer substrate 1 and a conductive layer transfer material 6 having a cushion layer 2 and a conductive layer 3 in this order on one surface of the transfer substrate. As shown in FIG. 6B, the cushion layer 2 and the conductive layer 3 of the conductive layer transfer material 6 shown in FIG. 6A are pressed and heated using a laminator on a glass substrate 8 (corresponding to a transparent substrate of a touch panel) as a transfer target. And paste them together. Subsequently, as shown in FIG. 6C, the cushioning layer 2 and the conductive layer 3 are transferred to the glass substrate 8 by peeling the transfer substrate 1.

When transferring the conductive layer 3 on the transfer substrate 1 onto the glass substrate 8, it is preferable that the glass substrate 8 has a temperature range of 90 ° C. or higher and 120 ° C. or lower. By setting it as this range, the conductive layer 3 can be transferred onto the glass substrate 8 without insulating the conductive layer. When the substrate temperature is lower than 90 ° C., the conductive layer 3 cannot be transferred onto the glass substrate 8, and when it exceeds 120 ° C., the conductive fibers are deformed by heat, and the conductive layer 3 is insulated.

Further, when the conductive layer 3 on the transfer substrate 1 is transferred onto the glass substrate 8, the transfer pressure is preferably in the range of 0.4 MPa to 0.8 MPa. By setting this range, the conductive layer 3 can be transferred onto the glass substrate 8 without disconnection. If the transfer pressure is less than 0.4 MPa, the conductive layer is not transferred to the glass substrate due to insufficient pressure at the time of transfer. If the transfer pressure exceeds 0.8 MPa, the conductive fiber is crushed and the conductive layer is disconnected due to the transfer pressure.

Next, after transferring the conductive layer 3 onto the glass substrate 8, the conductive layer 3 is exposed and developed to form a plurality of first transparent conductive patterns and a plurality of second transparent conductive patterns.

The touch panel can be manufactured through the above steps.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Synthesis Example 1)
<Synthesis of binder (A-1)>
7.79 g of methacrylic acid (MAA) and 37.21 g of benzyl methacrylate (BzMA) are used as monomer components constituting the copolymer, and 0.5 g of azobisisobutyronitrile (AIBN) is used as a radical polymerization initiator. These were polymerized in 55.00 g of a solvent propylene glycol monomethyl ether acetate (PGMEA) to obtain a PGMEA solution (solid content concentration: 45% by mass) of the binder (A-1) represented by the following formula. . The polymerization temperature was adjusted to 60 to 100 ° C.

The weight average molecular weight (Mw) of the binder (A-1) was measured using gel permeation chromatography (GPC). As a result, the weight average molecular weight (Mw) in terms of polystyrene was 30,000, and the molecular weight distribution (Mw / Mn) was 2.21.

(Preparation Example 1)
-Preparation of silver nanowire aqueous dispersion-
The following additive solutions A, G, and H were prepared in advance.

[Additive liquid A]
0.51 g of silver nitrate powder was dissolved in 50 mL of pure water. Then, 1N ammonia water was added until it became transparent. And pure water was added so that the whole quantity might be 100 mL.

[Additive liquid G]
An additive solution G was prepared by dissolving 0.5 g of glucose powder in 140 mL of pure water.

[Additive liquid H]
An additive solution H was prepared by dissolving 0.5 g of HTAB (hexadecyl-trimethylammonium bromide) powder in 27.5 mL of pure water.

Next, a silver nanowire aqueous dispersion was prepared as follows.

410 mL of pure water was placed in a three-necked flask, and 82.5 mL of additive solution H and 206 mL of additive solution G were added through a funnel while stirring at 20 ° C. (first stage). To this solution, 206 mL of additive solution A was added at a flow rate of 2.0 mL / min and a stirring rotation speed of 800 rpm (second stage). Ten minutes later, 82.5 mL of additive liquid H was added (third stage). Thereafter, the internal temperature was raised to 75 ° C. at 3 ° C./min. Then, the stirring rotation speed was reduced to 200 rpm and heated for 5 hours.

After the obtained aqueous dispersion was cooled, an ultrafiltration module SIP1013 (manufactured by Asahi Kasei Co., Ltd., molecular weight cut off 6,000), a magnet pump, and a stainless steel cup were connected with a silicone tube to form an ultrafiltration device. .

The obtained aqueous dispersion (aqueous solution) was put into a stainless steel cup, and ultrafiltration was performed by operating a pump. When the filtrate from the module reached 50 mL, 950 mL of distilled water was added to the stainless steel cup for washing. The above washing was repeated until the conductivity reached 50 μS / cm or less, followed by concentration to obtain a silver nanowire aqueous dispersion of Preparation Example 1.

For the silver nanowires in the silver nanowire aqueous dispersion of Preparation Example 1 obtained, the average minor axis length and the average major axis length were measured as follows. The results are shown in Table 1.

<Average minor axis length (average diameter) and average major axis length of silver nanowires>
Using a transmission electron microscope (TEM; JEM-2000FX, manufactured by JEOL Ltd.), 300 silver nanowires were observed, and the average minor axis length and average major axis length of the silver nanowires were determined.

<Coefficient of variation of minor axis length of silver nanowires>
Using a transmission electron microscope (TEM; JEM-2000FX, manufactured by JEOL Ltd.), 300 short axis lengths of the silver nanowires were observed, and the amount of silver transmitted through the filter paper was measured. Of silver nanowires having a major axis length of 5 μm or more was determined as a ratio (%) of silver nanowires having an aspect ratio of 10 or more.

The silver nanowires were separated when determining the ratio of silver nanowires using a membrane filter (Millipore, FALP 02500, pore size 1.0 μm).

<Sample No. 101 conductive layer transfer material>
<< Formation of cushion layer >>
On a polyethylene terephthalate (PET) film having an average thickness of 30 μm as a base material, a cushion layer coating solution having the following composition was applied and dried to form a cushion layer having an average thickness of 10 μm.

-Composition of coating solution for cushion layer-
Methyl methacrylate / 2-ethylhexyl acrylate / benzyl methacrylate / methacrylic acid copolymer (copolymerization composition ratio (molar ratio) = 55/30/10/5, weight average molecular weight = 100,000, glass transition temperature (Tg) = 70 ° C) ... 6.0 parts by mass Styrene / acrylic acid copolymer (copolymerization composition ratio (molar ratio) = 65/35, weight average molecular weight = 10,000, glass transition temperature (Tg) = 100 ° C.) -14.0 parts by mass-BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd.) ... 9.0 parts by mass-Mega-Fuck F-780-F (manufactured by Dainippon Ink & Chemicals, Inc.) ... 5 parts by mass-Methanol ... 10.0 parts by mass-Propylene glycol monomethyl ether acetate ... 5.0 parts by mass-Methyl ethyl ketone ... 55.5 parts by mass << Preparation of conductive layer>>
-Preparation of silver nanowire MFG dispersion (Ag-1)-
Polyvinylpyrrolidone (K-30, manufactured by Wako Pure Chemical Industries, Ltd.) and 1-methoxy-2-propanol (MFG) are added to the silver nanowire aqueous dispersion of Preparation Example 1, and after centrifuging, decantation is performed. The supernatant water was removed at, MFG was added, redispersion was performed, and the operation was repeated three times to obtain an MFG dispersion (Ag-1) of silver nanowires. The final MFG addition amount was adjusted so that the silver content was 1% by mass of silver.

-Preparation of negative conductive layer composition-
0.241 parts by mass of binder (A-1) of Synthesis Example 1, 0.252 parts by mass of KAYARAD DPHA (manufactured by Nippon Kayaku Co., Ltd.), 0.0252 parts by mass of IRGACURE 379 (manufactured by Ciba Specialty Chemicals Co., Ltd.), crosslinking EHPE-3150 (manufactured by Daicel Chemical Co., Ltd.) 0.0237 parts by mass, Megafac F781F (manufactured by DIC Corporation) 0.0003 parts by mass, propylene glycol monomethyl ether acetate (PGMEA) 0.9611 parts by mass, and 1 44.3 parts by mass of -methoxy-2-propanol (MFG) and 18.0 parts by mass of the MFG dispersion of silver nanowire (Ag-1) were added and stirred to prepare a negative conductive layer composition.

-Formation of conductive layer-
The obtained negative conductive layer composition was applied onto the film on which the cushion layer was formed and dried to form a conductive layer having an average thickness of 0.1 μm. As described above, sample No. 101 conductive layer transfer material was produced.

<Formation of transparent conductive film>
The transparent conductive film was formed by the following method.

[Transfered material]
A plurality of objects to be transferred including a metal layer and insulating films having different shapes having openings for exposing a part of the metal layer were prepared on a glass substrate having a thickness of 0.7 mm.

[Transcription]
The conductive layer and cushion layer of the conductive layer transfer material were transferred to a transfer target (a glass substrate having a thickness of 0.7 mm). The cushion layer is removed by shower development.

〔exposure〕
From the mask, 40 mJ / cm ² (illuminance 20 mW / cm ² ) exposure was performed with a high-pressure mercury lamp i-line (365 nm). In addition, since this electrically conductive film is comprised from the negative type conductive layer composition, a transparent conductive film is formed in the part irradiated with i line | wire.

〔developing〕
The exposed substrate was subjected to shower development for 30 seconds (shower pressure 0.04 MPa) with a developer in which 5 g of sodium bicarbonate and 2.5 g of sodium carbonate were dissolved in 5,000 g of pure water. Next, it rinsed with the shower of pure water.

[Connection structure]
7A to 7C show connection structures 1 to 3 each including a metal layer 100 (corresponding to peripheral wiring), an insulating film 102, and a transparent conductive film 104 (corresponding to a transparent conductive pattern) including silver nanowires. Regarding the connection structures 1 to 3, the insulating film 102 has a U-shape that opens in one direction, and the transparent conductive film 104 covers all exposed portions of the metal layer 100. In the connection structure 1 shown in FIG. 7A, the opening direction of the insulating film 102 is the same direction as the direction in which the transparent conductive film 104 extends. In the connection structure 2 shown in FIG. 7B, the opening direction of the insulating film 102 is opposite to the direction in which the transparent conductive film 104 extends. In the connection structure 3 shown in FIG. 7C, the opening direction of the insulating film 102 is a direction orthogonal to the extending direction of the transparent conductive film 104.

FIGS. 8A and 8B show connection structures 4 and 5 including a metal layer 100, an insulating film 102, and a transparent conductive film 104, respectively. In the connection structure 4 shown in FIG. 8A, the insulating film 102 has a rectangular shape that surrounds the exposed portion of the metal layer 100, and does not include an open portion. The transparent conductive film 104 covers all exposed portions of the metal layer 100.

8B, the opening direction of the insulating film 102 is opposite to the direction in which the transparent conductive film 104 extends, and the transparent conductive film 104 covers only a part of the exposed portion of the metal layer 100.

[Production conditions]
For the connection structures 1 to 5, a plurality of samples 1 to 21 having different thicknesses of the insulating film 102, the opening length of the insulating film 102, the temperature of the glass substrate during transfer, the transfer pressure, and the thickness of the transparent conductive film 104 are different. Prepared.

[Evaluation]
With respect to Samples 1 to 21, the contact property between the metal layer 100 and the transparent conductive film 104 and the corrosiveness of the metal layer 100 were evaluated. The contact property was evaluated by measuring a resistance value between the metal layer 100 and the transparent conductive film 104 using a tester. Those having a resistance value of 1 MΩ or more were judged to have poor contact properties. The corrosivity was evaluated by immersing the sample in an alkaline developer (potassium hydroxide aqueous solution) for 10 minutes and checking for corrosion. The table shown in FIG. 9 shows the manufacturing conditions and evaluation results of Samples 1 to 21.

In Samples 1 to 3, since the insulating film 102 has a U shape in a plan view and the opening length / film thickness is 25 or more, good results were obtained in terms of contact properties and corrosivity. In sample 4, since the insulating film 102 is a rectangle surrounding the exposed portion and does not have an open portion, good results with respect to contactability were not obtained. Regarding sample 5, since a part of the metal layer 100 was not covered with the transparent conductive film 104, good results were not obtained with respect to corrosivity.

The connection structure 2 was applied to samples 6 to 21. For Samples 8 and 9, since the opening length / film thickness was 25 or less, good results were not obtained for contactability.

As for the samples 16 and 20, the transparent conductive film 104 was not transferred, so that a good result was not obtained for the contact property.

<Modification>
FIG. 1 illustrates a touch panel to which the connection structure according to the present invention is applied in both vertical and horizontal directions. However, the configuration of the present invention is not limited to these examples. For example, a touch panel to which the connection structure according to the present invention is applied in any one of the vertical and horizontal directions is naturally possible.

DESCRIPTION OF SYMBOLS 10 ... Touch panel, 20 ... Transparent substrate, 30 ... 1st transparent conductive pattern, 32 ... 1st sensing part, 34 ... 1st connection part, 36 ... Connection part, 38 ... 1st insulating film, 48 ... 2nd transparent conductive pattern , 42 ... second sensing part, 44 ... second connecting part, 46 ... connecting part, 40 ... second insulating film, 50 ... insulating film, 60 ... first peripheral wiring, 70 ... second peripheral wiring, S ... sensor area

Claims (10)

1. A touch panel,
   A transparent substrate;
   A plurality of first transparent conductive patterns formed along the first direction on the transparent substrate and including a binder and conductive fibers;
   A plurality of second transparent conductive patterns formed on the transparent substrate along a second direction orthogonal to the first direction and including a binder and conductive fibers;
   A plurality of first peripheral wirings formed on the transparent substrate and electrically connected to ends of the first transparent conductive patterns;
   A plurality of second peripheral wirings formed on the transparent substrate and electrically connected to ends of the second transparent conductive patterns;
   A first connection structure for connecting the first transparent conductive patterns and the first peripheral wirings;
   A second connection structure for connecting each second transparent conductive pattern and each second peripheral wiring;
   The first connection structure includes:
   The first peripheral wiring, a U-shaped first insulating film formed on the first peripheral wiring and having an opening for exposing a part of the first peripheral wiring, and the exposed first peripheral wiring The first transparent conductive pattern covering
   The ratio of the film thickness of the first insulating film to the opening length of the first insulating film (opening length of the first insulating film / film thickness of the first insulating film) is 25 or more.
   Touch panel.
2. The second connection structure includes:
   The second peripheral wiring, a U-shaped second insulating film formed on the second peripheral wiring and having an opening for exposing a part of the second peripheral wiring, and the exposed second peripheral wiring And the second transparent conductive pattern covering
   The ratio of the film thickness of the second insulating film to the opening length of the second insulating film (the opening length of the second insulating film / the film thickness of the second insulating film) is 25 or more.
   The touch panel according to claim 1.
3. The ratio (film thickness of the first insulating layer / film thickness of the first transparent conductive pattern) between the film thickness of the first transparent conductive pattern and the film thickness of the first insulating film is 5 or more and 20 or less. Touch panel as described in 1.
4. The ratio between the thickness of the second transparent conductive pattern and the thickness of the second insulating film (the thickness of the second insulating layer / the thickness of the second transparent conductive pattern) is 5 or more and 20 or less. The touch panel described.
5. The touch panel according to claim 1, wherein the conductive fiber is a silver nanowire.
6. The touch panel according to claim 1, wherein the first peripheral wiring and the second peripheral wiring are made of a metal film.
7. The touch panel according to any one of claims 1 to 6, wherein the conductive fiber has a minor axis of 50 nm or less.
8. Forming a plurality of first peripheral wirings and a plurality of second peripheral wirings on a transparent substrate;
   A U-shaped first insulating film having an opening for exposing a part of the first peripheral wiring on each first peripheral wiring, and / or the second peripheral wiring on each second peripheral wiring. Forming a U-shaped second insulating film having an opening for exposing a portion thereof;
   Forming a conductive layer containing a binder and conductive fibers on a transfer substrate;
   The conductive layer on the transfer substrate is transferred onto the transparent substrate, covers the first peripheral wiring and / or the exposed portion of the second peripheral wiring, and each of the first peripheral wiring and the second peripheral wiring. Electrically connecting to the conductive layer;
   Patterning the conductive layer to form a plurality of first transparent conductive patterns extending in a first direction and a plurality of second transparent conductive patterns extending in a second direction orthogonal to the first direction;
   A method for manufacturing a touch panel comprising:
9. The method for manufacturing a touch panel according to claim 8, wherein when the conductive layer on the transfer base material is transferred onto the transparent substrate, the transparent substrate is in a temperature range of 90 ° C or higher and 120 ° C or lower.
10. The method for manufacturing a touch panel according to claim 8 or 9, wherein when the conductive layer on the transfer substrate is transferred onto the transparent substrate, a transfer pressure is in a range of 0.4 MPa to 0.8 MPa.

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