JP2014191806A - Production method of conductive sheet for touch panel and conductive sheet for touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive sheet for a touch panel which reduces reflection of external light and haze and gives excellent visibility of a displayed image, and a production method of the sheet.SOLUTION: A production method of an electrode sheet for a touch panel is provided, and the method comprises: a step of forming a rugged resin layer on at least one surface side of a transparent substrate, the resin layer having a rugged pattern on the outermost surface thereof, in which an average interval Sm of the rugged pattern ranges from 1.0 to 5.0 μm and a ten-point average roughness Rz of the ruggedness ranges from 0.3 to 2.0 μm; a step of forming a conductive metal layer by depositing a conductive metal by a vapor phase process on the rugged resin layer; a step of forming a patterned resist layer on the conductive metal layer; a step of forming a conductive metal pattern by etching the conductive metal layer present in an opening of the patterned resist layer; and a coating step of coating the conductive metal pattern side with a transparent resin.

Description

  The present invention relates to a method for manufacturing a conductive sheet for a touch panel, and a conductive sheet for a touch panel.

  In recent years, touch panels have become widespread as input devices for various electronic devices. Various position detection systems such as a resistive film system have been put to practical use as touch panels, and recently, capacitive touch panels capable of simultaneous multi-point input are attracting attention.

  FIG. 3 is a schematic plan view showing an example of the touch panel 20 based on the projected capacitive method, which is a kind of capacitive method. FIG. 4 is a schematic cross-sectional view showing an example of the A-A ′ cut surface of FIG. 3. The touch panel 20 includes a sensor electrode 12A extending in the X-axis direction and a sensor electrode 12B extending in the Y-axis direction, and each sensor electrode is connected to the extraction circuit 13. As shown in FIG. 4, the sensor electrode 12A and the sensor electrode 12B are arranged at positions that do not overlap each other in the Z-axis direction. In the example of FIG. 4, the sensor electrode 12 </ b> A is formed on one side of the transparent substrate 11, and the sensor electrode 12 </ b> B is formed on the surface of the transparent substrate 11 opposite to the sensor electrode 12 </ b> A. The sensor electrode 12A and the sensor electrode 12B may be arranged so as to be insulated from each other so as not to overlap with each other in the Z-axis direction. Examples of other forms include the examples of FIGS. 5 and 6. . In the example of FIGS. 5 and 6, the transparent base material 11 </ b> A on which the sensor electrode 12 </ b> A is formed and the transparent base material 11 </ b> B on which the sensor electrode 12 </ b> B is formed are bonded to each other via the adhesive layer 14. Yes.

As the electrode used for the sensor electrode, a transparent electrode such as ITO is conventionally used from the viewpoint of the visibility of the displayed image. However, due to the demand for high sensitivity of the touch panel, it is non-transparent with a small surface resistance. Metallic materials are also being studied.
When a non-transparent metal material is used, the sensor electrode is formed of a conductive metal pattern having an opening from the viewpoint of the visibility of a displayed image (for example, Patent Document 1).
3A is an individual sensor electrode 12A, and 12A (2) and 12A (3) in FIG. 3 are partially enlarged views of the sensor electrode 12A. As shown in 12A (1) of FIG. 3, the sensor electrode 12A has a shape in which a plurality of sensor electrode elements 12C arrayed apart in the X-axis direction are electrically connected at the corner portions by electrode element connection portions 12D. I am doing. In the example of FIG. 3, the shape of the sensor electrode element 12C is a square shape in the main part except the peripheral part, and both ends in the X-axis direction are triangular shapes that are cut in half in the Y-axis direction. ing. And as shown to 12A (2) of FIG. 3, each electrode element 12C is formed from the grid | lattice-like electroconductive metal pattern 12F which has the opening part 12E with a square shape. Since the conductive metal pattern 12F has the opening 12E, the transparency of the display of the image display panel can be seen to the extent that the visibility of the display through the touch panel is not impaired while using a non-transparent metal material. Secured.

According to the conductive metal pattern, it is possible to ensure transparency, but generally a non-transparent metal material has a gloss and reflects external light, so that the contrast of the image display panel is lowered and the visibility is reduced. There was a problem of getting worse.
Conventionally, a technique for blackening the surface of the conductive metal pattern on the viewer side is known for this problem.

  In Patent Document 2, an electromagnetic wave shielding member is formed by laminating a metal foil having at least one surface blackened by a chromate treatment in advance on a base material and forming a mesh made of a metal thin film by an etching treatment. A method is disclosed. The technique of Patent Document 2 is to simultaneously etch a portion of the metal foil that has been blackened and a portion that has not been blackened. In general, a portion that has been blackened and a portion that has not been blackened have different etching rates, and thus the shape of a mesh made of a metal thin film may be poor. Moreover, the method of laminating a metal foil on a substrate sometimes has insufficient adhesion.

  In Patent Document 3, using a mask having a dot-shaped through portion, a half-etching step of forming a halftone dot that is a recess that does not penetrate the metal foil on the surface of the metal foil, and the mask from the surface of the metal foil. A method of forming an image on a metal thin film having a mask removing step to be removed and having a blackening step between the half etching step and the mask removing step is disclosed. The technique of Patent Document 3 performs a blackening process after the etching process, but the blackening process is for increasing the contrast between the half-etched recesses of the metal thin film and the non-half-etched protrusions. In this case, only the bottom and side surfaces of the concave portion of the metal thin film are blackened, and the surface of the convex portion of the metal thin film is not blackened.

  On the other hand, in Patent Document 4, a metal foil of a conductive material having a roughened bonding surface to an adhesive layer is bonded to a transparent plastic substrate via an adhesive layer, and the metal foil is bonded to the adhesive layer. A method for producing a display film is described, which includes a step of transferring a rough surface shape of the surface. Patent Document 4 discloses that adhesion is improved by bonding a roughened metal foil to an adhesive layer. Patent Document 4 does not disclose a rough surface shape, and suppresses external light reflection by a blackening process.

JP 2011-070536 A JP 2003-86991 A JP 2010-280105 A Japanese Patent No. 3388682

  This invention is made | formed in view of the said situation, and it aims at providing the electrically conductive sheet for touchscreens which external light reflection and haze were reduced, and were excellent in the visibility of a display image, and its manufacturing method.

In the method for producing a conductive sheet for a touch panel according to the present invention, the outermost surface has a concavo-convex shape on at least one surface side of a transparent substrate, the average interval of the concavo-convex is Sm, and the ten-point average roughness of the concavo-convex Is Rz,
Sm is 1.0 to 5.0 μm,
Forming a concavo-convex resin layer having Rz of 0.3 to 2.0 μm;
Depositing a conductive metal on the concavo-convex resin layer by a vapor phase method to form a conductive metal layer;
Forming a patterned resist layer on the conductive metal layer;
Forming a conductive metal pattern by etching the conductive metal layer present in the opening of the patterned resist layer;
And a coating step of coating the conductive metal pattern side with a transparent resin.

The conductive sheet for a touch panel according to the present invention has an uneven resin layer having an uneven shape on the outermost surface, a conductive metal pattern, and a transparent resin layer in this order on at least one surface side of the transparent substrate.
At the interface between the concavo-convex resin layer and the conductive metal pattern, when the average interval of the concavo-convex of the concavo-convex resin layer is Sm and the ten-point average roughness of the concavo-convex is Rz,
Sm is 1.0 to 5.0 μm,
Rz is 0.3 to 2.0 μm.

  ADVANTAGE OF THE INVENTION According to this invention, external light reflection and haze are reduced, The electrically conductive sheet for touchscreens which were excellent in the visibility of a display image, and its manufacturing method can be provided.

Drawing 1 is an outline process figure showing an example of the manufacturing method of the conductive sheet for touchscreens concerning the present invention. FIG. 2 is a schematic cross-sectional view showing an example of a conductive sheet for a touch panel obtained by the method for manufacturing a conductive sheet for a touch panel according to the present invention. FIG. 3 is a schematic plan view showing an example of a touch panel using a projected capacitive method. FIG. 4 is a schematic cross-sectional view showing an example of the A-A ′ cut surface of FIG. 3. FIG. 5 is a schematic cross-sectional view showing another example of the A-A ′ cut surface of FIG. 3. FIG. 6 is a schematic cross-sectional view showing another example of the A-A ′ cut surface of FIG. 3. FIG. 7 is a schematic view showing an example of a method for forming an uneven resin layer using a roll mold.

  Hereinafter, the conductive sheet for a touch panel and the manufacturing method thereof according to the present invention will be described in order.

[Method for producing conductive sheet for touch panel]
In the method for producing a conductive sheet for a touch panel according to the present invention, the outermost surface has a concavo-convex shape on at least one surface side of a transparent substrate, the average interval of the concavo-convex is Sm, and the ten-point average roughness of the concavo-convex Is Rz,
Sm is 1.0 to 5.0 μm,
Forming a concavo-convex resin layer having Rz of 0.3 to 2.0 μm;
Depositing a conductive metal on the concavo-convex resin layer by a vapor phase method to form a conductive metal layer;
Forming a patterned resist layer on the conductive metal layer;
Forming a conductive metal pattern by etching the conductive metal layer present in the opening of the patterned resist layer;
And a coating step of coating the conductive metal pattern side with a transparent resin.

  The production method of the present invention will be described with reference to the drawings. Drawing 1 is an outline process figure showing an example of the manufacturing method of the conductive sheet for touchscreens concerning the present invention. In the example of FIG. 1, a transparent substrate is first prepared (FIG. 1 (A)). Next, the concavo-convex resin layer 2 having the concavo-convex shape whose outermost surface is the specific Sm and Rz is formed on one surface side of the transparent substrate 1 (FIG. 1B). A conductive metal layer 3 is formed on the uneven resin layer 2 by depositing a conductive metal by a vapor phase method (FIG. 1C). A patterned resist layer 4 is formed over the conductive metal layer 3 (FIG. 1D). Next, the conductive metal pattern 5 is formed by removing the conductive metal layer 3 present in the opening of the patterned resist layer 4 by an etching method (FIG. 1E). Thereafter, the patterned resist layer 4 is usually removed (FIG. 1F). By covering the conductive metal pattern 5 side with the transparent resin 6, a conductive sheet for a touch panel provided with the conductive metal pattern is obtained (FIG. 1G). By performing the said process on the both surfaces side of a transparent base material, an electrode sheet provided with a conductive metal pattern on both surfaces of the transparent base material 1 can also be manufactured (FIG. 2).

In the production method of the present invention, since the concavo-convex resin layer is formed on the outermost surface of the transparent substrate, a desired concavo-convex shape which is more stable than the case where the concavo-convex shape is provided on the metal thin film side is formed. And in order to deposit a conductive metal on the uneven | corrugated resin layer which has the said desired uneven | corrugated shape by a gaseous-phase method, the said specific uneven | corrugated shape is given to the transparent base material side surface of the obtained conductive metal pattern. It can be given as it is. In the present invention, the uneven shape of the uneven resin layer is such that the average interval Sm of the unevenness is 1.0 to 5.0 μm, and the ten-point average roughness Rz of the uneven shape is 0.3 to 2.0 μm. Is set. As a result, external light reflection by the surface of the conductive metal pattern on the transparent substrate side is suppressed. In the manufacturing method of the present invention, since the conductive metal layer for forming the conductive metal pattern is formed by a vapor phase method, the conductive metal adheres to the surface of the concavo-convex resin layer having the concavo-convex shape without any gap. Moreover, the adhesiveness of the uneven resin layer and the conductive metal pattern can also be improved. Furthermore, since the manufacturing method of this invention coat | covers transparent resin on the opposite side to the transparent base material of an electroconductive metal pattern, the uneven | corrugated shape of an uneven | corrugated resin layer can be filled and haze can be reduced.
From these things, according to the manufacturing method of this invention, external light reflection and haze are reduced, and manufacture of the electrically conductive sheet for touchscreens which was excellent in the visibility of a display image is attained. In addition, according to the manufacturing method of the present invention, the conductive metal does not need to be blackened, and in this case, there is no problem that the etching rate of the conductive metal and the blackened layer is different, and the normal production is not performed. The conductive metal pattern can be formed by the film etching process, and the productivity is excellent.

  In addition, the definition of the average interval Sm of unevenness and the ten-point average roughness Rz used in the present invention is based on JIS B0601 1994, and is handled by a surface roughness measuring instrument (model number: SE-3400 / manufactured by Kosaka Laboratory). It is also described in the manual (revised 1995, 07, 20).

In this invention, the average space | interval Sm of unevenness | corrugation and the ten-point average roughness Rz use the value measured on condition of the following using the surface roughness measuring device (model number: SE-3400 / made by Kosaka Laboratory).
1) Surface roughness detector stylus:
Model number / SE2555N (2 μm standard) manufactured by Kosaka Laboratory Ltd. (tip radius of curvature 2 μm / vertical angle: 90 degrees / material: diamond)
2) Measurement conditions of surface roughness measuring instrument:
Reference length (cutoff value λc of roughness curve): 0.8 mm
Evaluation length (reference length (cut-off value λc) × 5): 4.0 mm
Contact speed of stylus: 0.1 mm / s
Hereafter, each process of the manufacturing method of this invention is demonstrated in detail in order.

<Process for forming uneven resin layer>
This step is a step of forming an uneven resin layer on the transparent substrate. The concavo-convex resin layer is usually formed using a concavo-convex resin layer forming composition. Each configuration will be described below.

(Transparent substrate)
In the present invention, the transparent substrate is not particularly limited as long as it has transparency and has a desired insulating property, and may be appropriately selected from conventionally known materials used for touch panel applications.
Specifically, for example, transparent inorganic materials such as glass and ceramics, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate; acrylic resins such as polymethyl methacrylate; polyolefin resins such as cycloolefin polymers A cellulose-based resin such as triacetylcellulose; a polycarbonate-based resin; and a resin substrate such as a polyimide-based resin. Among them, it is preferable to use a resin base material from the viewpoint of handleability and weight reduction, and from the viewpoint of light transmission, it is more preferable to use a polyester resin base material or an acrylic resin base material. It is even more preferable to use a biaxially stretched polyester base material from the viewpoint of mechanical strength. Moreover, the resin base material which has flexibility is preferable from the point applicable to the roll-to-roll system which is excellent in productivity.
When the two sensor electrodes are manufactured using different transparent substrates, the two transparent substrates may be the same substrate or different substrates.

  The transparent substrate preferably has a transmittance in the visible light region of 80% or more, and more preferably 90% or more. Here, the transmittance | permeability of a transparent base material can be measured by JISK7361-1 (the test method of the total light transmittance of a plastic-transparent material).

  What is necessary is just to set the thickness of a transparent base material suitably in the range which can provide self-supporting property to a base material. Specifically, it is preferably in the range of 20 to 300 μm, more preferably in the range of 40 to 120 μm.

In the present invention, the transparent substrate may be appropriately subjected to known easy adhesion treatment such as corona discharge treatment on the surface thereof.
In the present invention, the transparent substrate may be composed of a single layer or a laminate having a plurality of layers. Examples of the laminate include those obtained by laminating a known hard coat layer, adhesion adjusting layer, low refractive index layer, high refractive index layer and the like on the resin base material.

(Rough resin forming composition)
The concavo-convex resin-forming composition contains at least a resin and may contain other additives as appropriate.
The resin used for forming the concavo-convex resin layer can be appropriately selected and used from resins that retain the formed concavo-convex shape. In the present invention, the “resin” is a concept including a resin component such as a monomer (monomer), an oligomer and a prepolymer in addition to a polymer polymer (polymer) which is a so-called narrowly defined resin. Specific examples of the resin include, for example, an ionizing radiation curable resin, a thermosetting resin, a thermoplastic resin, and the like. From the viewpoint of excellent moldability and mechanical strength, it may contain an ionizing radiation curable resin. preferable. The ionizing radiation means electromagnetic waves or charged particles having energy that can be cured by polymerizing molecules. For example, all ultraviolet rays (UV-A, UV-B, UV-C), visible rays, gamma rays , X-rays, electron beams and the like.

As the resin, an ionizing radiation curable resin is preferable because it is excellent in moldability and mechanical strength. In the present invention, being excellent in moldability means that it can be accurately molded into a desired shape.
Among them, the resin composition used in the present invention preferably contains at least one selected from the group consisting of acrylate-based, epoxy-based, and polyester-based ionizing radiation curable resins, and further includes an acrylate having a (meth) acryloyl group. It is preferable to include at least one selected from ionizing radiation curable resins.
Here, the (meth) acryloyl group represents each of an acryloyl group and a methacryloyl group, and the (meth) acrylate represents each of an acrylate and a methacrylate.

  Specific examples of the acrylate ionizing radiation curable resin include, for example, a (meth) acrylate oligomer, a prepolymer, or a monomer. Specifically, (meth) acrylate oligomers or prepolymers include relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyenes. Examples include oligomers or prepolymers composed of (meth) acrylic acid esters of polyfunctional compounds such as resins and polyhydric alcohols. In addition, (meth) acrylate monomers include ethyl (meth) acrylate, ethylhexyl (meth) acrylate, hexanediol (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) An acrylate etc. are mentioned. In addition, (meth) acrylate means an acrylate or a methacrylate.

Moreover, you may use conventionally well-known resin as a vapor deposition anchor use from the point which is excellent in the adhesiveness with the said transparent base material and the electroconductive metal mentioned later, and heat resistance.
As the resin used for the vapor deposition anchor, a resin having high heat resistance is preferable, and a mixture of a thermosetting resin and a thermoplastic resin is preferable.
It is preferable to use polyisocyanate as the thermosetting resin.
Examples of the thermoplastic resin include epoxy resins; acrylic resins such as polymethyl methacrylate and polyacrylic amide; polystyrene resins; cellulose resins such as nitrocellulose and ethyl cellulose; polyester resins; thermoplastic urethane resins. Modified olefin resins such as chlorinated polyethylene and chlorinated polypropylene; vinyl resins such as vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, butyral resins, amorphous polyolefins having a norbornene structure, etc. Can be mentioned. Further, the thermoplastic resin may have a reactive group capable of reacting with the thermosetting resin. These thermoplastic resins can be used individually by 1 type or in mixture of 2 or more types.

  The resin is usually used as a coating solution dissolved or dispersed in a solvent from the viewpoint of coating properties. As long as the effect of the present invention is not impaired, the coating liquid is, as necessary, a polymerization initiator, a polymerization inhibitor, an antioxidant, a viscosity modifier, a refractive index modifier, a fluorine for improving moldability. Or a silicon-based lubricant may be included. These may be appropriately selected from conventionally known materials.

When an ionizing radiation curable resin is used as the resin, a sensitizer may be added as a photopolymerization initiator or photopolymerization accelerator.
Specific examples of the photopolymerization initiator include acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethylchuram monosulfide when the ionizing radiation curable resin has a radical polymerizable functional group. Benzoins, benzoin methyl ether, thioxanthones, propiophenones, benzyls, acylphosphine oxides, 1-hydroxy-cyclohexyl-phenyl-ketone, and the like, and these are used alone or in combination. 1-Hydroxy-cyclohexyl-phenyl-ketone is available, for example, under the trade name Irgacure 184 (manufactured by Ciba Specialty Chemicals). Moreover, as α-aminoalkylphenones, for example, trade names Irgacure 907 and 369 are available.
Moreover, you may mix and use a photosensitizer. Specific examples of the photosensitizer include -butylamine, triethylamine, poly-n-butylphosphine and the like.
The addition amount of the photopolymerization initiator is preferably 0.1 to 10 parts by mass and more preferably 0.5 to 8 parts by mass with respect to 100 parts by mass of the ionizing radiation curable resin.

  Moreover, you may further contain a translucent fine particle etc. as a refractive index regulator, for example. As the light-transmitting fine particles, either inorganic type or organic type can be suitably used. Specific examples of translucent fine particles include, for example, polystyrene, melamine resin, acrylic resin, acrylic-styrene resin, benzoguanamine resin, benzoguanamine / formaldehyde condensation resin, polycarbonate resin, polyethylene, silicone resin and other plastic beads, silica (indefinite shape) Silica), alumina, zirconia, calcium carbonate, glass and the like.

  From the viewpoint of suppressing haze, the refractive index of the uneven resin layer is such that the refractive index difference between the refractive index of the transparent substrate and the refractive index of the transparent resin for coating described later is within 0.14. preferable. Therefore, it is preferable to use the resin and the refractive index adjusting agent in appropriate combination so that the refractive index difference is within the above range.

(Method for forming uneven resin layer)
The formation method of the uneven resin layer can be appropriately selected from conventionally known methods. For example, in addition to the sand blasting method and the shaping method, a method of forming a concavo-convex shape by phase separation by spinodal decomposition and the like can be mentioned.

  The sand blasting method is a method for forming a concavo-convex shape in the concavo-convex resin layer forming layer by spraying fine particles onto the concavo-convex resin layer forming layer, which has been cured in advance, at a high pressure. According to the sand blasting method, sand blast particles are randomly scattered, so that the concavo-convex shape can be easily formed in the concavo-convex resin layer.

Specifically, for example, on the transparent substrate, a coating liquid in which the above-described resin and each component used as necessary are dissolved or dispersed is applied, and a curing treatment is appropriately performed according to the type of the resin. It is set as the uneven | corrugated resin layer forming layer. By uniformly spraying the fine particles onto the uneven resin layer forming layer, an uneven resin layer having a uniform uneven shape can be obtained.
As the fine particles, inorganic fine particles such as metal particles, silica, alumina, and glass are preferably used. The average particle diameter of these particles is preferably 50 to 300 μm.
Also for sandblasting machine, preferably blast pressure of the particles 0.1 to 0.2 MPa, blasting content is preferably 10 to 20 g / cm ^2. Furthermore, the distance between the uneven resin layer forming layer and the fine particle injection port is preferably 500 to 600 mm.
Moreover, what is necessary is just to select suitably from the conventionally well-known methods as said coating method. For example, gravure coating method, reverse coating method, knife coating method, dip coating method, spray coating method, air knife coating method, spin coating method, roll coating method, printing method, dip pulling method, curtain coating method, die coating method, casting Method, bar coating method, extrusion coating method, E-type coating method and the like. What is necessary is just to set the film thickness of the uneven | corrugated resin layer forming layer suitably.

In the molding method, a desired concavo-convex shape is formed on the concavo-convex resin layer-forming layer comprising a coating solution obtained by applying the coating liquid in which the resin and each component used as necessary are dissolved or dispersed on the transparent substrate. After forming the concavo-convex shape of the concavo-convex resin layer forming original plate to the concavo-convex resin layer formation layer, the desired concavo-convex shape is formed by curing the resin of the concavo-convex resin layer formation layer. And a method of peeling the original plate for forming an uneven resin layer.
The uneven shape of the original for forming an uneven resin layer is an original having a shape corresponding to the uneven shape included in the uneven resin layer.

The concavo-convex resin layer forming original plate is not particularly limited as long as it is not deformed and worn when used repeatedly, and may be made of metal or resin. Usually, metal is preferably used because it is excellent in deformation resistance and wear resistance.
The concavo-convex shape of the original plate may be formed by a sand blast method or a bead shot method, or may be formed by anodizing a metal layer such as an aluminum layer.

Examples of the shape of the original for forming an uneven resin layer include a flat plate shape and a roll shape, and are not particularly limited, but a roll shape is preferable from the viewpoint of improving productivity. In the present invention, it is preferable to use a roll-shaped mold (hereinafter sometimes referred to as “roll mold”) as the original plate for forming the microprojection structure.
As the roll mold, for example, as described above, a cylindrical metal material is used as a base material, and the aluminum layer provided on the peripheral side surface of the base material directly or through various intermediate layers, as described above. In other words, the concavo-convex shape is produced by repeating the anodizing treatment and the etching treatment.

  As the spinodal decomposition method, for example, a mixture of an ionizing radiation curable resin as the resin and an incompatible resin with the ionizing radiation curable resin is used, and the resin and, if necessary, the transparent resin. A coating solution in which each component used is dissolved or dispersed is applied to form a coating film, and the solvent is evaporated from the coating film to form a phase separation structure having a regular or periodic average interphase distance. Then, the method of forming an uneven | corrugated shape by hardening | curing ionizing radiation curable resin by light irradiation is mentioned.

(Uneven shape)
The uneven resin layer has an Sm of 1.0 to 5.0 μm and an Rz of 0.3 when the average interval of the unevenness of the uneven resin layer is Sm and the ten-point average roughness of the unevenness is Rz. It has the relationship of -2.0 micrometers. Since the concavo-convex shape of the concavo-convex resin layer satisfies the above relationship, external light that is specularly reflected in the conductive metal pattern is appropriately diffusely reflected in the vicinity of the regular reflection angle. Therefore, necessary anti-glare properties can be obtained. Sm is preferably 1.0 to 5.0 μm and more preferably 1.0 to 3.0 μm from the viewpoint of contrast in a bright place. Rz is preferably 0.3 to 2.0 μm and more preferably 0.3 to 1.5 μm from the viewpoint of contrast in a bright place.
What is necessary is just to set the thickness of an uneven | corrugated resin layer suitably. Especially, it is preferable that it is 1-20 micrometers, and it is more preferable that it is 2-10 micrometers.

<Process for forming conductive metal layer>
This step is a step of forming a conductive metal layer by depositing a conductive metal by a vapor phase method. The vapor phase method used in the present invention may be appropriately selected from conventionally known methods. Specific examples of the vapor phase method include a physical vapor phase method such as a vapor deposition method and a sputtering method, and a chemical vapor phase method such as a chemical vapor deposition (CVD) method.
In the manufacturing method of the present invention, since the conductive metal is deposited by a vapor phase method, the conductive metal is deposited without any gaps on the surface of the concavo-convex layer having the concavo-convex shape, thereby providing the desired concavo-convex shape on the surface of the conductive metal. Thus, an external light reflection preventing function can be provided. Furthermore, adhesion is excellent by depositing a conductive metal on the uneven surface.

(Conductive metal)
In the present invention, the conductive metal can be appropriately selected from conventionally known materials used for touch panel applications. In the present invention, a transparent conductive metal oxide such as tin-doped indium oxide (ITO) or antimony-doped tin oxide (ATO) may be used, but even when an opaque conductive metal is used, it is satisfactory. Since a thin sheet pattern can be formed and a conductive sheet having excellent transmittance can be obtained, it is preferable to select a metal having a low surface resistance. Specific examples of such metals include, for example, copper, silver, gold, iron, aluminum, nickel, cobalt, tin, tungsten, chromium, titanium, palladium, manganese, zinc, rhodium, etc. Two or more types may be used, or an APC alloy containing silver, palladium and copper, or an alloy such as stainless steel may be used. From the viewpoint of conductivity, copper, aluminum, or nickel is preferable.
Moreover, when providing magnetic field shielding properties, a paramagnetic metal may be used as the conductive metal.

  What is necessary is just to set the film thickness of a conductive metal suitably in desired thickness according to a use. Specifically, it is preferably 0.01 μm to 10 μm, more preferably 0.3 μm to 5.0 μm, from the viewpoint of achieving both conductivity and visibility of the electrode sheet.

<Step of forming a patterned resist layer>
This step is a step of forming a patterned resist layer on the conductive metal layer. The method for forming the patterned resist layer is appropriately selected from conventionally known methods depending on the combination with the resist material to be used.
For example, using a known printing method capable of printing a resist material in a pattern, a method of printing in a pattern on a conductive metal layer, or using a photocurable resin as a resist material, the photocurable resin After printing the entire surface on the conductive metal layer, a patterned resist layer can be formed by exposing through an arbitrary mask pattern and developing.
The resist material only needs to have etching resistance and heat resistance, and may be appropriately selected from conventionally known resist materials.

  The pattern shape of the patterned resist layer may be the same pattern as the desired conductive metal pattern, and may be set as appropriate according to the shape of the desired conductive metal pattern. For example, the resist layer pattern is formed so as to have the following conductive metal pattern.

The shape of the conductive metal pattern in a plan view is a known pattern in which both conductivity and light transmittance are compatible, such as a mesh (lattice or net) shape or a stripe (stripe or parallel line group) shape. Among them, a mesh shape is preferable, and besides a square lattice shape, a regular pattern such as a rectangular lattice, a rhombus lattice, a hexagonal lattice, or a triangular lattice may be used, or an irregular mesh pattern including openings having a random shape may be used.
The mesh shape of the conductive metal pattern has a plurality of openings having these shapes, and the openings are line portions (line portions or line portions) that define the openings. The line portion usually has a uniform line width.
What is necessary is just to set suitably the line | wire width of the line part of an electroconductive metal pattern by the required light transmittance and surface resistivity. For example, the line width can be 50 μm or less, preferably 30 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. Moreover, from the point which avoids a disconnection and ensures electroconductivity, it is preferable to set it as 1 micrometer or more, and it is more preferable to set it as 3 micrometers or more.

The thickness of the patterned resist layer may be adjusted as appropriate. Specifically, it is usually in the range of 5 to 50 μm, and preferably 5 to 10 μm.
The line width of the patterned resist layer is preferably 1 to 50 μm, more preferably 3 to 30 μm, and still more preferably 3 to 10 μm. Moreover, it is preferable that the width | variety of the part which the transparent base material which the pattern-like resist layer has not adhered is exposed is 100-500 micrometers, and it is more preferable that it is 200-400 micrometers.

<Process for forming conductive metal pattern>
This step is a step of forming a conductive metal pattern by etching the conductive metal layer present in the opening of the patterned resist layer.
The etching method may be appropriately selected from conventionally known methods, and may be a wet etching method using an etchant or a dry etching method.

An etching solution for performing the wet etching method may be appropriately selected from conventionally known etching solutions according to the type of the conductive metal. Specifically, for example, ferric chloride / hydrochloric acid-based, hydrochloric acid / nitric acid-based, hydrobromic acid-based etching solutions, and the like can be given.
The wet etching may be a shower method or an immersion method.

  You may have the process of removing the said pattern-like resist layer as needed after an etching. The method for removing the patterned resist layer may be a known method, which can be removed by peeling or dissolving using an appropriately selected solvent or the like.

<Coating process for coating transparent resin>
This step is a step of covering the conductive metal pattern side with a transparent resin. By this step, in the opening where the conductive metal pattern is not formed, the concavo-convex shape on the surface of the concavo-convex resin layer is covered with the transparent resin, thereby suppressing haze.

The transparent resin used for coating is not particularly limited as long as it exhibits desired hardness and heat resistance after coating. Among these, from the point of suppressing haze, the refractive index of the transparent resin for coating is a resin in which the refractive index difference between the refractive index of the concavo-convex resin layer and the refractive index of the transparent substrate is within 0.14, respectively. It is preferable to select.
Specifically, for example, when a polyethylene terephthalate substrate having a refractive index of 1.58 is used as the transparent substrate, it is preferable to select and use a transparent resin having a refractive index of 1.44 to 1.72. .

  As the transparent resin used for the coating, it is preferable to use a conventionally known adhesive. By using the adhesive, the touch panel member as shown in FIG. 5 or 6 can be formed while covering the uneven shape.

  Specific examples of the adhesive include, for example, when a polyethylene terephthalate base material having a refractive index of 1.58 is used, bisphenol A type epoxy resin, bisphenol F type epoxy resin, tetrahydroxyphenylmethane type epoxy resin, novolak type epoxy resin, Resorcinol type epoxy resin, polyalcohol / polyglycol type epoxy resin, polyolefin type epoxy resin, epoxy resin such as alicyclic or halogenated bisphenol (all having a refractive index of 1.55 to 1.60) can be used. Other than the epoxy resin, (di) enes such as natural rubber (n = 1.52), polyisoprene (n = 1.521), poly 1,2-butadiene (n = 1.50), polyoxyethylene ( n = 1.4563), polyethers such as polyoxypropylene (n = 1.4495), polyesters such as polyvinyl acetate (n = 1.4665), polyvinyl propionate (n = 1.4665), polyurethane (N = 1.5 to 1.6), ethyl cellulose (n = 1.479), polyvinyl chloride (n = 1.54 to 1.55), polyacrylonitrile (n = 1.52), polymethacrylonitrile (N = 1.52), polysulfone (n = 1.633), polysulfide (n = 1.6), phenoxy resin (n = 1.5 to 1.6) and the like are preferable. That.

The method for coating the transparent resin may be any method that covers at least the uneven shape of the opening. The transparent resin may be applied over the entire surface, or only the opening may be coated in a pattern. The transparent resin is preferably applied over the entire surface from the viewpoint that the process is easy and the conductive metal pattern is protected.
For example, the transparent resin is coated by applying a coating solution in which the transparent resin and each component used as necessary are dissolved or dispersed by a conventionally known coating method.
Specific examples of the coating method include those similar to the coating method in the uneven resin layer forming layer.
The film thickness of the transparent resin layer only needs to be thicker than the concavo-convex shape of the concavo-convex resin layer, and may be set as appropriate. Among these, it is preferably 0.5 to 100 μm, preferably 0.5 to 50 μm. It is more preferable that

The haze of the electrode sheet for a touch panel thus obtained is preferably 5% or less, and more preferably 3% or less.
In the present invention, the haze value is measured according to JIS K-7136. In the case of a conductive sheet in which a conductive metal pattern is formed on one side of a transparent substrate as shown in FIG. 1G, the haze value is measured by overlapping two sheets as shown in FIG. 5 or FIG. On the other hand, in the case of the electrode sheet in which the conductive electrode pattern is formed on both surfaces of the transparent substrate as shown in FIG. 2, the haze of the electrode sheet alone may be measured.
As the haze meter, HM-150 manufactured by Murakami Color Research Laboratory Co., Ltd. can be used.

[Conductive sheet for touch panel]
The conductive sheet for a touch panel according to the present invention has an uneven resin layer having an uneven shape on the outermost surface, a conductive metal pattern, and a transparent resin layer in this order on at least one surface side of the transparent substrate.
At the interface between the concavo-convex resin layer and the conductive metal pattern, when the average interval of the concavo-convex of the concavo-convex resin layer is Sm and the ten-point average roughness of the concavo-convex is Rz,
Sm is 1.0 to 5.0 μm,
Rz is 0.3 to 2.0 μm.

In the conductive sheet for a touch panel of the present invention, the concavo-convex resin layer and the conductive metal pattern are adjacent to each other, and an interface where the concavo-convex resin layer and the conductive metal pattern are in contact, that is, one side of the conductive metal pattern. Since it has the above-mentioned specific concavo-convex shape, external light reflection is suppressed with respect to the surface. On the other hand, in the opening part of a conductive metal pattern, since the said specific uneven | corrugated shape does not exist, it is low haze.
For these reasons, by using the conductive sheet for a touch panel of the present invention, external light reflection and haze are reduced, and a touch panel with excellent display image visibility can be manufactured.

  About each structure of the electrically conductive sheet for touchscreens of this invention, it can be set as the thing similar to what was described in the manufacturing method of the said electrically conductive sheet for touchscreens. That is, the conductive metal pattern of the conductive sheet for a touch panel of the present invention can be formed by depositing a conductive metal by a vapor phase method.

The touch panel manufactured using the conductive sheet for a touch panel according to the present invention is used, for example, disposed on a display surface of an image display panel such as a liquid crystal panel, or a monochrome or color printed matter expressed by halftone dots. You may arrange | position and use on surfaces, such as a photograph formed in photographic paper.
An image display device including a touch panel using the conductive sheet of the present invention includes, for example, a portable information terminal such as a tablet computer, various telephones such as a smartphone, a television receiver, a personal computer, an electronic book terminal, a monitor display, a digital camera, The present invention can be widely applied to image display devices having position input means such as a digital photo frame, measuring instrument, medical device, amusement device, office device, cash dispenser, electronic blackboard, and vending machine.

  Hereinafter, the present invention will be specifically described with reference to examples. Note that the present invention is not limited by these descriptions.

(Example 1: Production of conductive sheet for touch panel)
(1) Continuous belt-shaped and uncolored transparent biaxially stretched polyethylene terephthalate (PET) film (thickness: 100 μm) on one surface side with a ratio of zirconia fine particles (average particle diameter 40 nm) / acrylic UV curable resin = 57/43 20 parts by mass, initiator (Irgacure 184, manufactured by BASF) 5 parts by mass, surfactant TF-1682 0.1 parts by mass dissolved in propylene glycol monomethyl ether (PGME) was applied by a bar coater, After drying at 80 ° C., an ultraviolet ray having an exposure amount of 100 mj was irradiated to form a concavo-convex resin layer forming layer (refractive index of 1.58) having a thickness of 7 μm. The surface of the uneven resin layer forming layer was treated by sand blasting so that Rz was 0.7 μm and Sm was 1.0 μm.
The average interval Sm of the unevenness and the ten-point average roughness Rz were confirmed under the following conditions using a surface roughness measuring instrument (model number: SE-3400 / manufactured by Kosaka Laboratory).
1) Surface roughness detector stylus:
Model number / SE2555N (2 μm standard) manufactured by Kosaka Laboratory Ltd. (tip radius of curvature 2 μm / vertical angle: 90 degrees / material: diamond)
2) Measurement conditions of surface roughness measuring instrument:
Reference length (cutoff value λc of roughness curve): 0.8 mm
Evaluation length (reference length (cut-off value λc) × 5): 4.0 mm
Contact speed of stylus: 0.1 mm / s

Next, a copper layer (conductive metal layer) having a thickness of 1.5 μm was formed by a vapor deposition method using a vacuum vapor deposition machine.
Next, a casein-based photosensitive negative resist was applied to the entire surface of the copper by a dipping method, and contact exposure was performed by irradiating ultraviolet rays from a mercury lamp using a photomask. A photomask having the shape of 12A in FIG. 2 having a mesh pattern portion having a square opening shape, a mesh pattern width of 3 μm, a mesh pattern pitch of 300 μm, and a bias angle of 49 degrees was used.
Next, the laminate after the contact exposure was developed with water, hardened, and baked at 100 ° C.
Next, an etching was performed by spraying a ferric chloride solution of 50 ° C. and 42 ° Baume as an etching solution by a spray method to form an opening.
Subsequently, it was washed with water, the resist was peeled off, washed, and further dried at 60 ° C. to form a first conductive metal pattern having a mesh pattern portion (X film).

(2) A second conductive metal pattern was formed in the same manner as (1) above except that a mask pattern (having the shape of 12B in FIG. 2) different from (1) was used (Y film) .
After covering the fine uneven layer on the conductive metal pattern side surface of the X film and the Y film using an optical adhesive material having a refractive index of 1.58, respectively, the conductive metal pattern side surface of the X film and The conductive sheet for touch panels was manufactured by bonding the surface of the Y film on the conductive metal pattern side through the optical adhesive material.
The conductive metal pattern of the X film and the conductive metal pattern of the Y film were bonded so as not to overlap each other as shown in FIG.

(Example 2: Production of conductive sheet for touch panel)
In Example 1, the setting of the sandblast method was changed so that Rz on the surface of the uneven resin layer forming layer was 1.5 μm and Sm was 2.0 μm, and the thickness of the copper layer (conductive metal layer) was 3 A conductive sheet for a touch panel of Example 2 was obtained in the same manner as Example 1 except that the thickness was changed to 0.0 μm.

(Comparative Example 1: Production of conductive sheet for touch panel)
In Example 1, the setting of the sandblasting method was changed so that the Rz on the surface of the uneven resin layer forming layer was 0.2 μm and Sm was 0.8 μm, and the optical adhesive material had a refractive index of 1.58. Except having changed, it carried out similarly to Example 1, and obtained the conductive sheet for touchscreens of the comparative example 1. FIG.

(Comparative Example 2: Production of conductive sheet for touch panel)
In Example 1, the setting of the sand blast method was changed so that the Rz on the surface of the uneven resin layer forming layer was 1.5 μm and Sm was 5.2 μm, and the optical adhesive material had a refractive index of 1.58. Except having changed, it carried out similarly to Example 1, and obtained the conductive sheet for touchscreens of the comparative example 2. FIG.

(Comparative Example 3: Production of conductive sheet for touch panel)
In Example 1, the setting of the sandblast method was changed so that Rz on the surface of the uneven resin layer forming layer was 0.2 μm and Sm was 3.0 μm, and the optical adhesive material had a refractive index of 1.58. Except having changed, it carried out similarly to Example 1, and obtained the conductive sheet for touchscreens of the comparative example 2. FIG.

(Transmittance evaluation)
The spectral transmittance at a wavelength of 380 to 780 nm of the conductive sheets obtained in Examples and Comparative Examples was measured with a spectrophotometer V-7100 manufactured by JASCO Corporation, and luminous transmittance (specified in JIS Z 8701). Stimulation value Y). The results are shown in Table 1.
[Evaluation criteria for luminous transmittance]
○: Luminous transmittance was 70% or more.
X: The luminous transmittance was less than 70%.

(Haze evaluation)
The haze of the electrically conductive sheet obtained by the Example and the comparative example was measured based on JIS-K7105 using the brand name NDH2000 type | mold made by Nippon Denshoku Industries Co., Ltd. The results are shown in Table 1.
[Haze Evaluation Criteria]
○: Haze was 3% or less.
X: Haze was over 3%.

(External light reflection evaluation)
The conductive sheets obtained by Examples and Comparative Examples are placed on a black display device, and a fluorescent lamp is projected from the front surface of the display device on which the conductive sheet is placed, and the fluorescent lamp is reflected. Was visually observed. The results are shown in Table 1.
[External light reflection evaluation criteria]
○: I didn't mind the reflection of fluorescent lights.
X: Reflection of fluorescent light was recognized.

[Summary of results]
In the conductive sheets of Examples 1 and 2 manufactured by the manufacturing method according to the present invention, the conductive metal pattern has an average interval Sm of 1.0 to 5.0 μm and a ten-point average roughness Rz of 0.00. Since the uneven shape of 3 to 2.0 μm is provided, and the opening is covered with the adhesive material whose uneven shape is a transparent resin, it is possible to achieve both low haze and suppression of external light reflection, It was revealed that the luminous transmittance was excellent and the display image was excellent in visibility.
In the conductive sheets of Comparative Examples 1 to 3, since the concavo-convex shape of the opening was covered with the adhesive material, the haze was good, but the reflection was recognized because Sm and Rz were out of the above range. The contrast of the displayed image was lowered.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2, 2A, 2B Concavity and convexity resin layer 3 Conductive metal layer 4 Patterned resist layer 5, 5A, 5B Conductive metal pattern 6, 6A, 6B Transparent resin 10 Touch panel electrode sheet 11, 11A, 11B Transparent base Material 12A X direction sensor electrode 12B Y direction sensor electrode 12C Sensor electrode element 12D Sensor electrode element connection portion 12E Opening portion 12F Conductive metal pattern 13 Extraction circuit 14 Adhesive layer 20 Touch panel 21 Concavity and convexity resin layer 21 'Concavity and convexity resin layer forming layer 31 Coating device 32 Roll mold 33 Pressing roller 34 Peeling roller

Claims (2)

A method for manufacturing an electrode sheet for a touch panel,
When the outermost surface has an uneven shape on at least one surface side of the transparent substrate, the average interval of the unevenness is Sm, and the ten-point average roughness of the unevenness is Rz,
Sm is 1.0 to 5.0 μm,
Forming a concavo-convex resin layer having Rz of 0.3 to 2.0 μm;
Depositing a conductive metal on the concavo-convex resin layer by a vapor phase method to form a conductive metal layer;
Forming a patterned resist layer on the conductive metal layer;
Forming a conductive metal pattern by etching the conductive metal layer present in the opening of the patterned resist layer;
The manufacturing method of the electrode sheet for touchscreens which has a coating process which coat | covers transparent resin on the said conductive metal pattern side. On at least one surface side of the transparent substrate, the outermost surface has an uneven resin layer having an uneven shape, a conductive metal pattern, and a transparent resin layer in this order,
At the interface between the concavo-convex resin layer and the conductive metal pattern, when the average interval of the concavo-convex of the concavo-convex resin layer is Sm and the ten-point average roughness of the concavo-convex is Rz,
Sm is 1.0 to 5.0 μm,
The electrode sheet for touch panels whose Rz is 0.3-2.0 micrometers.