JP2013084026A - Touch sensor for touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch sensor for a touch panel that is suitable as a touch sensor of a touch panel using a capacitance system, does not impair the appearance of a display, and is high in a manufacturing yield.SOLUTION: There is provided a touch sensor for a touch panel in which two light transmissive conductive materials are arranged so as to face each other via an adhesive layer. The light transmissive conductive materials have a metal mesh pattern with the thickness of a thin metal wire equal to or smaller than 1.25 μm on a base material. The storage modulus at 23°C of an adhesive composition composing the adhesive layer is 1×10Pa or less.

Description

  The present invention relates to a touch sensor used for a touch panel, and more particularly to a touch sensor suitably used for a projection capacitive touch panel.

  In electronic devices such as personal digital assistants (PDAs), notebook PCs, OA devices, medical devices, and car navigation systems, touch panels are widely used as input means for these displays.

  The touch panel includes an optical method, an ultrasonic method, a capacitance method, a resistance film method, and the like depending on a position detection method. In the resistive film type touch panel, a light-transmitting conductive material and a glass with a transparent conductor layer are arranged to face each other with a spacer interposed therebetween. It has a structure that measures voltage. On the other hand, a capacitive touch panel is basically characterized by having a transparent conductor layer on a substrate, has no moving parts, and has high durability and high transmittance. It is applied in applications.

  As a transparent electrode (light transmissive conductive material) for use in a touch panel, a material in which a light transmissive conductive film made of ITO is generally formed on a substrate has been used. However, since the ITO conductive film has a large refractive index and a large surface reflection of light, there is a problem that the total light transmittance is lowered, and since the flexibility is low, the ITO conductive film cracks when bent and the electric resistance value is low. There was a problem of getting higher.

  In addition, there are conductivity and light transmittance as performance required for a conductive material having a light transmissive conductive film. However, when a conductive thin film such as ITO is formed, a certain degree of film thickness is required to increase the conductivity. There is a problem in that a thin body film is required, thereby reducing the transmittance. Therefore, in order to produce a light-transmitting conductive material having high conductivity and high light transmittance, in recent years, metal fine wires are formed in a mesh pattern on a light-transmitting substrate, and the line width and spacing of the metal thin wires are further increased. A light-transmitting conductive material that maintains high light transmittance and imparts high conductivity by adjusting the pattern shape or the like is known.

  After forming a thin catalyst layer on the substrate and forming a resist pattern on the substrate as a light-transmitting conductive material that forms fine metal wires in a mesh pattern, the metal layer is laminated on the resist openings by plating. A semi-additive method for forming a conductive pattern by removing a resist layer and a base metal protected by the resist layer is disclosed in, for example, Japanese Unexamined Patent Application Publication Nos. 2007-287994 and 2007-287953. .

  In recent years, a method using a silver salt photographic light-sensitive material using a silver salt diffusion transfer method as a conductive material precursor has also been proposed. For example, in JP-A-2003-77350, JP-A-2005-250169, JP-A-2007-188655, etc., a conductive material precursor having a physical development nucleus layer and a silver halide emulsion layer at least in this order on a substrate. A technique for forming a metallic silver pattern by allowing a soluble silver salt forming agent and a reducing agent to act on the body in an alkaline solution is disclosed. Patterning by this method can reproduce a uniform line width, and since silver has the highest conductivity among metals, higher conductivity can be obtained with a thinner film thickness than other methods. Furthermore, the silver pattern film obtained by this method has an advantage that it is more flexible and resistant to bending than the ITO conductive film.

  A touch panel using the projected capacitive method among the capacitive methods is manufactured by attaching a light-transmitting conductive material in which a plurality of electrodes are patterned on the same plane to each other with an adhesive. Yes. However, when a metal mesh pattern is used as a light-transmitting conductive material with patterned electrodes, there is a problem in that the appearance of the display viewed through the touch panel may be impaired due to irregular reflection of light rays due to the thickness of the thin metal wires. It was. Such a problem can be improved by reducing the thickness of the fine line of the metal mesh pattern. However, before and after bonding with an adhesive, the conductivity of the light-transmitting conductive material may change, and it may become impossible to use as a touch sensor for a touch panel, and an improvement has been demanded.

  On the other hand, Patent Document 1 describes a pressure-sensitive adhesive having a specific storage elastic modulus as a pressure-sensitive adhesive used for a base-less double-sided pressure-sensitive adhesive sheet having a large difference in peel force between heavy and light release films. It is described that the pressure-sensitive adhesive layer of the optical member-bonded pressure-sensitive adhesive sheet excellent in absorption and durability has a specific storage elastic modulus.

JP 2010-168425 A JP 2010-77287 A

  An object of the present invention is to provide a touch sensor for a touch panel that does not impair the appearance of a display and has a high manufacturing yield.

The above object of the present invention is achieved by the following invention.
(1) A touch sensor for a touch panel arranged such that two light-transmitting conductive materials face each other with an adhesive layer interposed therebetween, wherein the light-transmitting conductive material has a thickness of a thin metal wire on a substrate. A touch sensor for a touch panel, having a metal mesh pattern of 25 μm or less and having a storage elastic modulus at 23 ° C. of a pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer of 1 × 10 ⁶ Pa or lower.

  According to the present invention, it is possible to provide a touch sensor for a touch panel that does not impair the appearance of the display and has a high manufacturing yield.

An example of an electrode pattern included in the light-transmitting conductive material of the present invention

  Hereinafter, the present invention will be described in detail.

  The light transmissive conductive material included in the touch sensor for a touch panel of the present invention has a metal mesh pattern on a base material. As the metal mesh pattern, a known shape having a metal thin wire as a side can be used, for example, a triangle such as a regular triangle, an isosceles triangle, a right triangle, a square such as a square, a rectangle, a rhombus, a parallelogram, a trapezoid, (Positive) Hexagon, (Positive) Octagon, (Positive) Dodecagon, (Positive) N-gonal such as Dodecagon, Circle, Ellipse, Star, etc. Or a combination pattern of two or more types can be used. Further, even if the side is not a straight line, it may be constituted by, for example, a zigzag line or a wavy line. Furthermore, a stripe pattern or a brickwork pattern as disclosed in Japanese Patent Application Laid-Open No. 2002-223095 can also be used. Any of these shapes can be used in the present invention, but a square, a regular triangle, and a regular hexagon are preferable.

  In the present invention, when the unit figure is a square, the fine line interval of the metal mesh pattern is the length of one side of the square. If the unit graphic is not a square, a square having the same area as the unit graphic is calculated, and the length of one side is defined as the fine line interval in the unit graphic. The fine wire interval of the metal mesh pattern is preferably 400 μm or less. The line width of the fine metal wires of the metal mesh pattern is preferably 20 μm or less, more preferably 1 to 15 μm, and still more preferably 1 to 10 μm. The sheet resistance of the surface (conductive portion) provided with such a metal mesh pattern is preferably 500 Ω / □ or less, more preferably 200 Ω / □, as measured by the four-terminal method (terminal spacing 5 mm) of JIS K7134. □ or less, more preferably 100Ω / □ or less.

  FIG. 1 shows an example of an electrode pattern composed of a metal mesh included in the light-transmitting conductive material of the present invention. In FIG. 1, a is a metal mesh pattern part (conductive part), b is an electrode terminal part, and c is a non-image part (non-conductive part). The touch sensor for a touch panel of the present invention is arranged so that two light-transmitting conductive materials face each other with an adhesive layer interposed therebetween. At that time, in the non-image portion c included in one light-transmitting conductive material, It arrange | positions so that the metal mesh pattern part a which the other light transmissive conductive material has may be located. In FIG. 1, an example of an electrode pattern included in one light transmissive conductive material is shown as a pattern 1, and an example of an electrode pattern included in the other light transmissive conductive material is shown as a pattern 2.

  In the present invention, the metal mesh pattern is preferably made of gold, silver, copper, nickel, aluminum, and a composite material thereof. As a method of forming these metal mesh patterns, a method using a silver salt photosensitive material, a method of applying electroless plating or electrolytic plating to a silver image obtained by using the same method, a silver paste using a screen printing method, etc. A method of printing conductive ink, a method of printing conductive ink such as silver ink by inkjet method, or forming a conductive layer by vapor deposition or sputtering, forming a resist film on it, exposure, development, etching A known method such as a method obtained by removing a resist layer, a method of attaching a metal foil such as a copper foil, forming a resist film thereon, exposing, developing, etching, removing a resist layer, etc. be able to. Among them, a method using a silver salt photosensitive material that can reduce the thickness of the metal mesh pattern to be manufactured and can easily form an extremely fine metal pattern is preferable. As a method of using this silver salt photosensitive material, JP2003-77350A, JP2005250169A, JP2007-188655A, JP2007-129205A, JP2008-153596A. In particular, when a silver salt diffusion transfer method as described in JP-A-2003-77350, JP-A-2005-250169, or JP-A-2007-188655 is used, a metal mesh is used. The thickness of the pattern can be reduced, which is particularly preferable.

  If the thickness of the metal mesh pattern produced by these methods (thickness of the fine metal wire) is too thick, when the light-transmitting conductive material is bonded to the touch sensor, the light is irregularly reflected by the thickness of the fine metal wire. The appearance of the displayed display may be impaired, and if it is too thin, it will be difficult to ensure the conductivity necessary for the touch panel. Therefore, the thickness needs to be 1.25 micrometers or less, 0.05-1 micrometer is preferable, More preferably, it is 0.1-0.5 micrometer.

  As a base material used for the light-transmitting conductive material of the present invention, plastic, glass, rubber, ceramics and the like are preferably used. These substrates preferably have a total light transmittance of 60% or more. Among plastics, a resin film having flexibility is preferably used in terms of excellent handleability. Specific examples of the resin film used as the substrate include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylic resins, epoxy resins, fluorine resins, silicone resins, polycarbonate resins, diacetate resins, Examples thereof include resin films having a thickness of 50 to 300 μm made of triacetate resin, polyarylate resin, polyvinyl chloride, polysulfone resin, polyether sulfone resin, polyimide resin, polyamide resin, polyolefin resin, cyclic polyolefin resin, and the like. A known layer such as an easy-adhesion layer may be provided on the substrate.

  In addition to the base material and the metal mesh pattern located on the base material, the light-transmitting conductive material of the present invention has a known layer such as a hard coat layer, an antireflection layer, an adhesive layer and an antiglare layer on the metal mesh pattern. It can be provided on the side far from the material) or on the side opposite to the mesh pattern of the substrate. Moreover, well-known layers, such as a physical development nucleus layer, an easily bonding layer, and an adhesive bond layer, can be provided between a base material and a metal mesh pattern.

  The pressure-sensitive adhesive layer in the present invention will be described. The pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive as a main component, and is used for bonding light-transmitting conductive materials. Here, the main component means that 50% by mass or more of the total solid content of the adhesive layer is an adhesive, preferably 65% by mass or more, and more preferably 85% by mass or more. The thickness of the pressure-sensitive adhesive layer is not particularly limited. However, in the case where the two conductive surfaces are arranged on the pressure-sensitive adhesive layer side, the thickness for maintaining a state where there is no conduction between the respective light-transmitting conductive materials is necessary. is there. On the other hand, if the thickness is too large, the distance between the electrode patterns of the two light-transmitting conductive materials can be increased, and the user may feel uncomfortable when viewing it, and the appearance of the touch sensor may be impaired. The preferred thickness of the pressure-sensitive adhesive layer is 5 to 300 μm, more preferably 10 to 200 μm.

In the touch sensor for a touch panel of the present invention, the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer has a storage elastic modulus at 23 ° C. of 1 × 10 ⁶ Pa or lower and a storage elastic modulus of 2.0 × 10 ⁵ Pa or lower. It is more preferable that If a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive composition having a storage modulus that is too high is used, the fine wire of the metal mesh pattern of the light-transmitting conductive material may break, and the desired conductivity cannot be obtained. In some cases, it was a defective touch sensor. If the storage elastic modulus is too small, peeling after sticking tends to occur, so the lower limit is preferably about 1 × 10 ⁴ Pa. The storage elastic modulus can be measured by a method described in JP 2010-168425 A, JP 2010-77287 A, or the like.

The pressure-sensitive adhesive layer may have a single-layer structure of the same component, or may have a multilayer structure composed of pressure-sensitive adhesives having different components, for example, a strong pressure-sensitive adhesive layer and a weak pressure-sensitive adhesive layer. In such a case, the storage elastic modulus at 23 ° C. of the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer in contact with the metal mesh pattern of the light-transmitting conductive material is 1 × 10 ⁶ Pa or less.

  The pressure-sensitive adhesive used in the pressure-sensitive adhesive composition is not particularly limited, and an acrylic pressure-sensitive adhesive or a rubber-based pressure-sensitive adhesive can be used, but an acrylic pressure-sensitive adhesive that is highly transparent and widely used for optical applications is preferable.

  Examples of the rubber-based adhesive include natural rubber, a copolymer of natural rubber and an acrylic component such as methyl methacrylate, a styrene block copolymer and a hydrogenated product thereof, and a styrene-butadiene-styrene block copolymer and Examples thereof include hydrogenated products. These may be used singly or in combination of two or more.

  As acrylic pressure-sensitive adhesives, hydroxyl-containing monomers such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxyhexyl (meth) acrylate are copolymerized. (Meth) acrylic polymers, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl ( Has an alkyl group such as (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isomyristyl (meth) acrylate, etc. That include those acrylic monomer is copolymerized. These may be used singly or in combination of two or more.

  The acrylic polymer can be produced by any known production method such as solution polymerization, bulk polymerization, and emulsion polymerization.

  In the said adhesive composition, tackifiers, such as a tackifier, can be used suitably.

  In the pressure-sensitive adhesive composition, a crosslinking agent can be appropriately used. Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, an oxazoline crosslinking agent, and a peroxide.

  Isocyanate-based crosslinking agents include diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, diisocyanate adducts modified with various polyols, isocyanurate rings, burettes and allophanates. Examples include the formed polyisocyanate compound.

  The pressure-sensitive adhesive composition may contain other known additives, for example, powders such as vulcanizing agents, tackifiers, colorants, pigments, dyes, surfactants, plasticizers, surfaces Applications that use lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, UV absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particles, foils, etc. Depending on the case, it can be added appropriately.

  There is no restriction | limiting in particular about the method of bonding together two light transmissive conductive materials using the said adhesive composition. For example, a method in which a pressure-sensitive adhesive layer is applied to an arbitrary support, the pressure-sensitive adhesive layer is transferred to one light-transmitting conductive material, and then the other light-transmitting conductive material is bonded. There is a method in which a pressure-sensitive adhesive layer is applied to a transparent conductive material and another light-transmitting conductive material is bonded. Regarding the direction of bonding, when the conductive surfaces (metal mesh pattern side) of the two light transmissive conductive materials are arranged on the pressure-sensitive adhesive layer side, one of the two light transmissive conductive materials transmits light. When the conductive surface (metal mesh pattern side) of the conductive material and the non-conductive surface (metal mesh pattern side and the opposite side through the support) of the other light-transmissive conductive material are arranged on the adhesive layer side In either case, the present invention can be applied.

  Examples of the method of coating the adhesive (adhesive layer) on an arbitrary support or light-transmitting conductive material include a reverse coater, a comma coater, a lip coater, and a die coater, which can be selected according to the purpose. it can.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to a following example, unless the summary is exceeded.

<Example 1>
A polyethylene terephthalate film having a thickness of 100 μm was used as the substrate. The total light transmittance of this substrate was 91%.

  Next, according to the following prescription, a physical development nucleus layer coating solution was prepared, applied onto a substrate, and dried to provide a physical development nucleus layer.

<Preparation of palladium sulfide sol>
Liquid A Palladium chloride 5g
Hydrochloric acid 40ml
1000ml distilled water
B liquid sodium sulfide 8.6g
1000ml distilled water
Liquid A and liquid B were mixed with stirring, and 30 minutes later, the solution was passed through a column filled with an ion exchange resin to obtain palladium sulfide sol.

<Preparation of physical development nucleus layer coating solution> per 1 m ^{2 of the} palladium sulfide sol 0.4 mg
0.2% aqueous 2 mass% glyoxal solution
Surfactant (S-1) 4mg
Denacol EX-830 50mg
(Polyethylene glycol diglycidyl ether manufactured by Nagase ChemteX Corporation)
10 mass% SP-200 aqueous solution 0.5 mg
(Nippon Shokubai Co., Ltd. polyethyleneimine; average molecular weight 10,000)

  Subsequently, an intermediate layer, a silver halide emulsion layer, and a protective layer having the following composition were coated on the physical development nucleus layer in order from the side closer to the substrate to obtain a silver salt photosensitive material 1. The silver halide emulsion was prepared by a general double jet mixing method for photographic silver halide emulsions. This silver halide emulsion was prepared with 95 mol% of silver chloride and 5 mol% of silver bromide, and an average grain size of 0.15 μm. The silver halide emulsion thus obtained was subjected to gold sulfur sensitization using sodium thiosulfate and chloroauric acid according to a conventional method. The silver halide emulsion thus obtained contains 0.5 g of gelatin per gram of silver.

<Intermediate layer composition / per 1 m ² >
Gelatin 0.5g
Surfactant (S-1) 5mg
Dye 1

<Silver halide emulsion layer composition / 1m ² per>
Gelatin 0.5g
Silver halide emulsion 4.0g Equivalent to silver 1-Phenyl-5-mercaptotetrazole 3mg
Surfactant (S-1) 20mg

<Protective layer composition / per 1 m ² >
1g of gelatin
Amorphous silica matting agent (average particle size 3.5μm) 10mg
Surfactant (S-1) 10mg

  The silver salt light-sensitive material 1 obtained in this way and a transparent original having the pattern 1 of FIG. 1 on the same plane are in close contact with each other, and through a resin filter that cuts light of 400 nm or less with a contact printer using a mercury lamp as a light source. Exposed. The metal mesh pattern portion (conductive portion) a of the pattern 1 and the pattern 2 in FIG. 1 is formed of a mesh whose unit figure having a line width of 7 μm and a fine line interval of 300 μm is a square.

  Thereafter, the film was immersed in the following diffusion transfer developer at 20 ° C. for 90 seconds, and then the silver halide emulsion layer, intermediate layer and protective layer were removed by washing with warm water at 40 ° C. and dried. Thus, a light transmissive conductive material 1-1 having a metal mesh pattern having the shape of pattern 1 in FIG. 1 was obtained. The obtained light transmissive conductive material had an image with the same line width and fine line spacing as the transparent original. When the film thickness of the metal mesh pattern was examined with a confocal microscope (Latertec Corp., Optics C130), it was 0.1 μm.

  Also, a 100 mm square metal mesh pattern composed of a square mesh with the same line width and line spacing as the metal mesh pattern portion (conductive portion) a of the light transmissive conductive material 1-1 is used as the light transmissive conductive material 1-1. It produced similarly. When the sheet resistance of this metal mesh pattern was measured by the four-terminal method of JIS K7134 (terminal interval 5 mm), it was 50Ω / □.

  In the same manner as the light-transmitting conductive material 1-1, a light-transmitting conductive material 1-2 having a metal mesh pattern having the shape of the pattern 2 in FIG. 1 was obtained.

  The resistance of the terminal part b of the obtained light transmissive conductive material 1-1 was measured with a tester. The obtained results are shown in Table 1 (before bonding).

<Diffusion transfer developer composition>
Potassium hydroxide 25g
Hydroquinone 18g
1-phenyl-3-pyrazolidone 2g
Potassium sulfite 80g
N-methylethanolamine 15g
Potassium bromide 1.2g
Total volume with water 1000mL
Adjust to pH = 12.2.

  Next, the adhesive composition used for an adhesive layer was produced as follows.

  In a reaction vessel, 233 parts by mass of ethyl acetate as a solvent, 98 parts by mass of butyl acrylate, 1.0 part by mass of acrylic acid, 1.0 part by mass of 4-hydroxybutyl acrylate, 2,2′-azobisisobutyro After adding 0.1 part by mass of nitrile and carrying out nitrogen substitution, the temperature was raised to 55 ° C. and a polymerization reaction was carried out for 15 hours. An acrylic polymer solution having a weight average molecular weight of 970,000 was obtained. 40 parts by mass of a styrene oligomer (Picolastic A75, manufactured by Eastman Chemical Co., Ltd.) is added as a tackifier to 100 parts by mass of the solid content of the acrylic polymer, and isocyanurate trimer of hexamethylene diisocyanate (Mitsui Chemicals). 0.1 part by mass of Takenate D-170N (manufactured by Polyurethane Co., Ltd.) was added to prepare an adhesive composition.

  The storage elastic modulus of the produced pressure-sensitive adhesive composition was measured under the following conditions, and the storage elastic modulus (G ′) at 23 ° C. was measured. The results are shown in Table 1.

  TA Instruments ARES, deformation mode: torsion, measurement frequency: constant frequency 1 Hz, heating rate: 5 ° C./min, measurement temperature: measured from near glass transition temperature of adhesive to 160 ° C., shape: parallel plate 8 .0mmφ, sample thickness: 0.5-2mm (initial stage)

  This pressure-sensitive adhesive composition was applied to the conductive surface (metal mesh pattern side) of the light-transmitting conductive material 1-1 so that the dry thickness was 25 μm, and dried at 120 ° C. for 3 minutes to form a pressure-sensitive adhesive layer. .

  After alignment, the conductive surface (metal mesh pattern side) of the light transmissive conductive material 1-2 was bonded to the light transmissive conductive material 1-1 on which the pressure-sensitive adhesive layer was applied. Thereafter, the nip roll pressure of the film laminating machine was adjusted to 0.5 MPa / m, and the pressure was applied while being conveyed at a speed of 1 m / min to produce a touch sensor.

  The electrical resistance between the terminals on the light transmissive conductive material 1-1 side of the obtained touch sensor was measured with a tester. The results are shown in Table 1 (after bonding).

  The obtained touch sensor was placed on a display depicting a night scene and its appearance quality was evaluated. The case where the display screen looks uncomfortable is indicated as ◯, the case where the display screen is somewhat uncomfortable, △, the case where the display screen appears whitish and uncomfortable, is indicated as ×, ○ and △ are allowed as touch sensors, and × is not possible. These results are shown in Table 1.

<Example 2>
The pressure-sensitive adhesive composition was prepared as follows.

  In a reaction vessel, 233 parts by mass of ethyl acetate as a solvent, 98 parts by mass of butyl acrylate, 1.0 part by mass of acrylic acid, 1.0 part by mass of 4-hydroxybutyl acrylate, 2,2′-azobisisobutyro After adding 0.1 part by mass of nitrile and carrying out nitrogen substitution, the temperature was raised to 55 ° C. and a polymerization reaction was carried out for 15 hours. An acrylic polymer solution having a weight average molecular weight of 970,000 was obtained. To 100 parts by mass of the solid content of this acrylic polymer, 30 parts by mass of styrene and 0.15 parts by mass of benzoyl peroxide as a polymerization initiator were added, and the atmosphere was replaced with nitrogen for 5 hours at 60 ° C., 70 A graft polymerization reaction was performed at 0 ° C. for 8 hours to obtain a modified acrylic polymer. To 100 parts by mass of this modified acrylic polymer, 80 parts by mass of a copolymer of α-methylstyrene and styrene (Eastman Chemical Co., Crystallex 3085), a tolylene diisocyanate adduct of trimethylolpropane (manufactured by Nippon Polyurethane Co., Ltd., Coronate L) 0.15 parts by mass was added to prepare an adhesive composition.

  A touch sensor was prepared and evaluated in the same manner as in Example 1 except that the pressure-sensitive adhesive composition was used. These results are shown in Table 1.

<Example 3>
The pressure-sensitive adhesive composition was prepared as follows.

  In a reaction vessel, 233 parts by mass of ethyl acetate as a solvent, 98.5 parts by mass of butyl acrylate, 0.5 parts by mass of acrylic acid, 1.0 part by mass of 4-hydroxybutyl acrylate, 2,2′-azobisiso After adding 0.1 mass of butyronitrile and carrying out nitrogen substitution, it heated up at 55 degreeC and performed the polymerization reaction for 15 hours. An acrylic polymer solution having a mass average molecular weight of 1,120,000 was obtained. While adding 40 parts by weight of styrene and 10 parts by weight of acryloylmorpholine and 0.25 parts by weight of benzoyl peroxide as a polymerization initiator with respect to 100 parts by weight of the solid content of this acrylic polymer, the temperature was changed to 60 ° C. For 5 hours and at 70 ° C. for 8 hours to obtain a modified acrylic polymer. 100 parts by mass of this modified acrylic polymer, 80 parts by mass of a styrene oligomer (SX-85, manufactured by Yasuhara Chemical Co., Ltd.) as a tackifier, 0.15 mass of a tolylene diisocyanate adduct of trimethylolpropane (manufactured by Nippon Polyurethane Co., Ltd., Coronate L) Part was added and the adhesive composition was produced.

  A touch sensor was prepared and evaluated in the same manner as in Example 1 except that the pressure-sensitive adhesive composition was used. These results are shown in Table 1.

<Comparative Example 1>
The pressure-sensitive adhesive composition was prepared as follows.

A reaction vessel was charged with 80 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of acrylic acid, and 0.6 parts by mass of Irgacure-184 (manufactured by Ciba Geigy) as a photopolymerization initiator. Was irradiated with ultraviolet rays at an irradiation dose of about 100 mJ / cm ² . To the viscous material obtained by this irradiation, 1 part by mass of trimethylolpropane triacrylate was blended as an internal crosslinking agent to prepare a pressure-sensitive adhesive composition.

  A touch sensor was prepared and evaluated in the same manner as in Example 1 except that the pressure-sensitive adhesive composition was used. These results are shown in Table 1.

<Example 4>
The light transmissive conductive material 2-1 was used in the same manner as in Example 1 except that the silver halide emulsion per 1 m ^{2 of the} silver halide emulsion layer of Example 1 was changed to 2.0 g (use pattern 1 in FIG. 1). 2-2 (using pattern 2 in FIG. 1) was prepared. The thickness of the metal mesh pattern measured with a confocal microscope (Latertec Corp., Optics C130) was 0.05 μm.

  A 100 mm square metal mesh pattern composed of a square mesh with the same line width and line spacing as the metal mesh pattern portion (conductive portion) a of the light transmissive conductive material 2-1 is used as the light transmissive conductive material 2-1. It produced similarly. When the sheet resistance of this metal mesh pattern was measured by the four-terminal method of JIS K7134 (terminal interval 5 mm), it was 480Ω / □.

  A touch sensor was prepared and evaluated in the same manner as in Example 1 except that the light-transmitting conductive materials 2-1 and 2-2 were used. These results are shown in Table 1.

<Example 5>
The light-transmitting conductive material 1-1 of Example 1 was subjected to electrolytic nickel plating using the following plating solution under the conditions of a liquid temperature of 60 ° C., a current density of 2 A / cm ² , and a plating time of 2 minutes. A transparent conductive material 3-1 was produced. The thickness of the metal mesh pattern after plating measured by a confocal microscope (Lasertec Corporation, Optics C130) was 0.5 μm. Similarly, the light transmissive conductive material 1-2 was plated to produce a light transmissive conductive material 3-2.

  A 100 mm square metal mesh pattern composed of a square mesh with the same line width and line spacing as the metal mesh pattern portion (conductive portion) a of the light transmissive conductive material 3-1 is used as the light transmissive conductive material 3-1. It produced similarly. When the sheet resistance of this metal mesh pattern was measured by the four-terminal method of JIS K7134 (terminal interval 5 mm), it was 20Ω / □.

<Plating solution>
240 g of nickel sulfate
Nickel chloride 45g
Boric acid 30g
Bring the total volume to 1000 mL with water.
Adjust to pH = 4.6.

  A touch sensor was prepared and evaluated in the same manner as in Example 1 except that the light-transmitting conductive materials 3-1 and 3-2 were used. These results are shown in Table 1.

<Example 6>
Electrolytic nickel plating was performed on the light-transmitting conductive material 1-1 of Example 1 using the plating solution of Example 5 under conditions of a liquid temperature of 60 ° C., a current density of 2 A / cm ² , and a plating time of 4 minutes. A light-transmitting conductive material 4-1 was produced. The thickness of the fine metal wire after plating measured by a confocal microscope (Latertec Corp., Optics C130) was 1.0 μm. Similarly, the light transmissive conductive material 1-2 was plated to produce a light transmissive conductive material 4-2.

  A 100 mm square metal mesh pattern made of a square mesh with the same line width and line interval as the metal mesh pattern portion (conductive portion) a of the light transmissive conductive material 4-1 is referred to as the light transmissive conductive material 4-1. It produced similarly. When the sheet resistance of this metal mesh pattern was measured by the four-terminal method of JIS K7134 (terminal interval 5 mm), it was 10Ω / □.

  A touch sensor was prepared and evaluated in the same manner as in Example 1 except that the light-transmitting conductive materials 4-1 and 4-2 were used. These results are shown in Table 1.

<Comparative example 2>
Electrolytic nickel plating was performed on the light-transmitting conductive material 1-1 of Example 1 using the plating solution of Example 5 under conditions of a liquid temperature of 60 ° C., a current density of 2 A / cm ² , and a plating time of 6 minutes. A light-transmitting conductive material 5-1 was produced. The thickness of the metal fine wire after plating measured with a confocal microscope (Latertec Corp., Optics C130) was 1.5 μm. Similarly, the light transmissive conductive material 1-2 was plated to produce a light transmissive conductive material 5-2.

  A 100 mm square metal mesh pattern made of a square mesh with the same line width and line spacing as the metal mesh pattern portion (conductive portion) a of the light transmissive conductive material 5-1 is used as the light transmissive conductive material 3-1. It produced similarly. When the sheet resistance of this metal mesh pattern was measured by the four-terminal method of JIS K7134 (terminal interval 5 mm), it was 5Ω / □.

  A touch sensor was prepared and evaluated in the same manner as in Example 1 except that the light-transmitting conductive materials 5-1 and 5-2 were used. These results are shown in Table 1.

  From the results in Table 1, it can be seen that a touch sensor that is suitable as a touch sensor for a touch panel using a capacitance method and that has a high manufacturing yield can be obtained.

a Metal mesh pattern part (conductive part)
b Electrode terminal part c Non-image part (non-conductive part)

Claims (1)

A touch sensor for a touch panel arranged such that two light transmissive conductive materials face each other through an adhesive layer, wherein the light transmissive conductive material has a thickness of a thin metal wire on a base material of 1.25 μm or less A touch sensor for a touch panel, wherein the storage elastic modulus at 23 ° C. of the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer is 1 × 10 ⁶ Pa or less.

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