JP2009218034A - Transparent conductive film and touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent conductive film and a touch panel for raising durability and flexibility for pen writing and improving the pen-writing durability in the vicinity of a frame. <P>SOLUTION: The transparent conductive film includes a transparent base material, a cushion layer formed on one surface of the transparent base material, a hard-coated layer formed on the cushion layer, an adhesive layer formed on the other surface of the transparent base material, and a first transparent conductive film formed on the adhesive layer. Film thickness of the adhesive layer of the transparent conductive film is 5-15 nm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transparent conductive film and a touch panel. In particular, it relates to a transparent electrode, a touch panel, a transparent conductive film useful as an electromagnetic wave shielding film, and a touch panel.

  Transparent conductive films have the property of having both conductivity and optical transparency, and are therefore used industrially as transparent electrodes, electromagnetic shielding films, planar heating films, antireflection films, etc. ing. In recent years, transparent conductive films have attracted attention as electrodes for touch panels.

  There are various types of touch panels such as a capacitive coupling method, an optical method, and a resistive film method. Among them, the transparent conductive film is used in a resistance film type that identifies a touch position by contacting upper and lower electrodes and a capacitive coupling method that senses a change in capacitance. In particular, the resistive film method can be used for pen input and is relatively inexpensive, so that it is widely used for portable terminals and portable game machines. In this resistive film method, contact between conductive films is not avoided on the principle of operation, and the development of transparent conductive films with high dot durability has been promoted in order to extend the hit point life of the touch panel. In addition, with the thinning of the mobile terminal, a highly flexible transparent conductive film with input durability near the frame is desired.

Due to the thin frame of liquid crystal panels and the diversification of usage environments, high durability of touch panels incorporated in displays is required. For that purpose, high durability of the transparent conductive film used as an electrode is indispensable (refer patent document 1).
JP2007-213886

  An object of the present invention is to provide a transparent conductive film and a touch panel that improve pen writing durability and flexibility, and improve pen writing durability in the frame periphery.

  The invention according to claim 1 of the present invention includes a transparent substrate, a cushion layer formed on one surface of the transparent substrate, a hard coat layer formed on the cushion layer, and another layer on the transparent substrate. A transparent conductive film comprising: an adhesion layer formed on one surface; and a first transparent conductive film formed on the adhesion layer.

  The invention according to claim 2 of the present invention is the transparent conductive film according to claim 1, wherein the thickness of the adhesion layer is 5 nm or more and 15 nm or less.

In the invention according to claim 3 of the present invention, the elastic modulus of the cushion layer is 1 × 10 ⁴ N / m ² or more and 1 × 10 ⁶ N / m ² or less, and the thickness of the cushion layer is 1 μm or more and 50 μm or less. The transparent conductive film according to claim 1, wherein the transparent conductive film is formed.

  The invention according to claim 4 of the present invention is the transparent conductive film according to claim 1, wherein the film thickness of the first transparent conductive film is 5 nm or more and 50 nm or less.

  The invention according to claim 5 of the present invention includes a transparent substrate, a cushion layer formed on one surface of the transparent substrate, a hard coat layer formed on the cushion layer, and another layer on the transparent substrate. An adhesion layer formed on one surface; a first transparent conductive film formed on the adhesion layer; and a second transparent conductive film disposed opposite to the first transparent conductive film with a spacer interposed therebetween. The touch panel is characterized by comprising a touch panel.

  The invention according to claim 6 of the present invention is the touch panel according to claim 5, wherein the thickness of the adhesion layer is 5 nm or more and 15 nm or less.

In the invention according to claim 7 of the present invention, the elastic modulus of the cushion layer is 1 × 10 ⁴ N / m ² or more and 1 × 10 ⁶ N / m ² or less, and the thickness of the cushion layer is 1 μm or more and 50 μm or less. The touch panel according to claim 5, wherein the touch panel is provided.

  The invention according to claim 8 of the present invention is the touch panel according to claim 5, wherein the film thickness of the first transparent conductive film is 5 nm or more and 50 nm or less.

  ADVANTAGE OF THE INVENTION According to this invention, while improving pen writing durability and flexibility, the transparent conductive film and touch panel which improve pen writing durability in a frame peripheral part can be provided.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In the embodiments, the same components are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 1, a transparent conductive film 1 according to an embodiment of the present invention includes a cushion layer 3 on one surface of a transparent substrate 2, a hard coat layer 4 on the cushion layer 3, and a transparent substrate 2. An adhesive layer 5 is provided on the other surface, and a first transparent conductive film 6 is provided on the adhesive layer 5.

  The transparent conductive film 1 according to the embodiment of the present invention includes a cushion layer 3 between the hard coat layer 4 and the transparent substrate 2. By providing the cushion layer 3 between the hard coat layer 4 and the transparent substrate 2, pen writing durability when the transparent conductive film 1 is mounted on the touch panel 11 can be enhanced.

  The transparent conductive film 1 according to the embodiment of the present invention includes an adhesion layer 5 between the transparent substrate 2 and the first transparent conductive film 6. By providing the adhesion layer 5 between the transparent substrate 2 and the first transparent conductive film 6, the flexibility of the transparent conductive film 1 is improved, and the pen writing durability of the frame portion when mounted on the touch panel 11 is improved. Can increase the sex.

  Examples of the material for forming the transparent substrate 2 according to the embodiment of the present invention include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polyamides such as nylon 6 and nylon 66 Polyimide; Polyarylate; Polycarbonate; Polyacrylate; Polyethersulfone, polysulfone, and a copolymer film of these copolymers that are not stretched or stretched can be used. Also, other plastic films with high transparency can be used. The thickness of the transparent substrate 2 can be 10 μm or more and 200 μm considering the flexibility of the transparent substrate 2. In the material of the transparent substrate 2, polyethylene terephthalate or the like can be preferably used.

  In addition, these transparent base materials 2 can perform surface treatments, such as an easily bonding process, a plasma process, and a corona treatment, and can improve adhesiveness.

  As the transparent resin material forming the cushion layer 3 according to the embodiment of the present invention, a polyester resin, a polyamide resin, a polyacrylic resin, a polyurethane resin, a silicon resin, or a copolymer thereof can be used. Moreover, other transparent resin which satisfy | fills the characteristic of the cushion layer 3 mentioned later can be used.

  Further, the cushion layer 3 includes photopolymerization initiators such as acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, n-butylamine, triethylamine, poly-n-butylphosphine, etc. These photosensitizers may be contained.

The hardness of the cushion layer 3 is in the range of 1 × 10 ⁴ N / m ^{2 to} 1 × 10 ⁶ N / m ² in terms of elastic modulus, and the thickness of the cushion layer 3 is in the range of 1 μm to 50 μm. It is characterized by that. More preferably, the thickness of the cushion layer 3 is 5 μm or more and 10 μm.

When the elastic modulus representing the hardness of the cushion layer 3 exceeds 1 × 10 ⁶ N / m ² , the cushion layer 3 becomes hard and cushioning properties cannot be obtained, and the ITO that is the first transparent conductive film 6 (described later) ) Cracks. On the other hand, if it is less than 1 × 10 ⁴ N / m ² , the cushion layer 3 becomes inelastic and easily deforms by pressurization.

  When the thickness of the cushion layer 3 is less than 1 μm, good cushioning properties cannot be obtained, and when the thickness of the cushion layer 3 is greater than 50 μm, the transparency is impaired.

  As a material for forming the hard coat layer 4 according to the embodiment of the present invention, bifunctional or higher functional (meth) acrylates and multi-sensitive acrylates can be used. Any material can be suitably used as long as it has two or more reactive acrylic groups in the molecule. For example, polyethylene glycol diacrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate , Ethoxylated polypropylene glycol dimethacrylate, propoxylated ethoxylated bisphenol A diacrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, tricyclodecane dimethanol (meta ) Acrylate, ethoxylated cyclohexanedimethanol di (meth) acrylate, ethoxylated glycerin triacrylate, trimethylolpropane tri (meth) a Relate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexaacrylate, etc. The present invention is not limited to these.

  Further, as the material for forming the hard coat layer 4, urethane (meth) acrylate can be used by polyfunctional (meth) acrylate. Any material can be suitably used as the urethane (meth) acrylate as long as it has a urethane bond and a (meth) acrylate structure in the molecule. For example, what is produced | generated from diisocyanate, diol, and a hydroxyl-containing (meth) acrylate can be used. For example, as the diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3-dimethyl-4,4-diphenyl diisocyanate , And kishirange diisocyanate. For example, as the diol, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,9-nanonediol, neopentyl glycol, 1,4-cyclohexanediol, Examples thereof include polyethylene oxide diol, polypropylene oxide diol, polytetramethylene oxide diol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, polycaprolactone diol, polyester dial, and polycarbonate diol. Examples of acrylates having hydroxyl groups include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 4-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 2-hydroxyethyl acrylate caprolactone-modified products. , 2-hydroxyethyl acrylate oligomer, 2-hydroxypropyl acrylate oligomer, pentaerythritol triacrylate and the like can be mentioned as examples, but the invention is not limited thereto.

  Polyester acrylate can also be used as the polyfunctional acrylate of the material forming the hard coat layer 4. Examples of the polyester acrylate include those that can be easily formed by reacting a polyester polyol with a 2-hydroxy acrylate or 2-hydroxy acrylate monomer in general, but the invention is not limited thereto.

  Further, epoxy acrylate can also be used as a material for forming the hard coat layer 4. The epoxy acrylate is an acrylate obtained by opening an epoxy group of an epoxy resin and acrylated with acrylic acid, and those using an aromatic ring or an alicyclic epoxy can be more preferably used.

  The above acrylate can be suitably used by using only one kind or by mixing two or more kinds.

  Furthermore, a photopolymerization initiator can be used for the hard coat layer 4. Examples of the photopolymerization initiator include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, etc., but the present invention is not limited thereto. Further, n-butylamine, triethylamine, poly-n-butylphosphine and the like can be mixed and used as a photosensitizer.

  These resins and photopolymerization initiators can be dissolved in a solvent and the solid content can be adjusted to 30% by weight or more and 80% by weight or less, more preferably 40% by weight or more and 60% by weight or less, and coated on the substrate.

  As a method for applying the cushion layer 3 and the hard coat layer 4, methods such as a dipping method, a roll coating method, a screen printing method, and a spray method can be used.

  As a material for forming the adhesion layer 5 according to the embodiment of the present invention, for example, an inorganic compound such as an oxide, sulfide, or fluoride can be used. Preferably, silicon oxide, aluminum oxide, or the like can be suitably used.

  The thickness of the adhesion layer 5 is preferably 5 nm or more and 15 nm or less. When the film thickness of the adhesion layer 5 is less than 5 nm, it is difficult to obtain film uniformity, and when the film thickness of the adhesion layer 5 exceeds 15 nm, the transparency is lowered.

  Examples of the conductive material for forming the first conductive thin film 6 according to the embodiment of the present invention include oxides such as indium oxide, tin oxide, and zinc oxide, and mixed oxides thereof. However, it is not limited to these. In particular, a mixed oxide (ITO) of indium oxide and tin oxide can be preferably used.

  The conductive material of the first conductive thin film 6 can contain additives such as Al, Zr, Ga, Si, and W as necessary.

  The film thickness of the first transparent conductive film 6 is preferably 5 nm or more and 50 nm or less. When the film thickness of the first transparent conductive film 6 is less than 5 nm, it becomes difficult to obtain film uniformity. When the film thickness of the first transparent conductive film 6 exceeds 50 nm, the transparency is lowered. End up.

  The method for producing the adhesion layer 5 and the first transparent conductive film 6 of the present invention is not particularly limited, but is preferably produced by using a vacuum film-forming method such as a sputtering method, a vacuum deposition method, an ion plating method, a CVD method or the like. can do.

  As shown in FIG. 4, the touch panel 11 according to the embodiment of the present invention includes a cushion layer 3 on one surface of the transparent substrate 2, a hard coat layer 4 on the cushion layer 3, and the other of the transparent substrate 2. The transparent conductive film 1 provided with the adhesion layer 5 on the surface and the first transparent conductive film 6 on the adhesion layer 5, the first transparent conductive film 6 of the transparent conductive film 1 disposed opposite to the first transparent conductive film 6 via the spacer 9. 2 transparent conductive films 7 and a substrate 8 are provided.

  The transparent conductive film 1 which concerns on embodiment of this invention can be used suitably for the touch panel of a resistance film system among touch panels. The resistive film type touch panel 11 includes a second transparent conductive film 7 and a substrate 8 which are disposed to face the first transparent conductive film 6 of the transparent conductive film 1 according to the embodiment of the present invention. ing. The first transparent conductive film 6 and the second transparent conductive film 7 are kept away from each other by the spacer 9. The hard coat layer 4 side of the transparent conductive film 1 becomes the front surface of the touch panel 11, and characters and the like are input by the pen 10.

  In the touch panel 11 according to the embodiment of the present invention, two electrodes (a first transparent conductive film 6 and a second transparent conductive film) are formed by the spacer 9 in a state where the pen 10 and the hard coat layer 4 are not touched. No current flows because 7) is not in contact. On the other hand, when the hard coat layer 4 is touched with the pen 10, the hard coat layer 4 bends due to pressure, and a current flows in contact with the electrode (second transparent conductive film 7) on the substrate 8 (glass surface) side. At this time, the position input by the pen 9 is detected by measuring the voltage division ratio due to the resistance between the first transparent conductive film 6 of the transparent conductive film 1 and the second transparent conductive film 7 of the substrate 8. Can do.

  The material of the transparent conductive film 1 is omitted because it has been described above, and the material of the substrate 8 and the second transparent conductive film 7 will be described. The material of the substrate 8 is not limited to glass and can be used as long as it is transparent. Further, the same material and the same forming method as those of the transparent substrate 2 described above can be used. The same material and the same manufacturing method as the first transparent conductive film 6 can be used for the second transparent conductive film 7, and the film thickness of the second transparent conductive film 7 is the same as that of the first transparent conductive film 6. It may be the same.

  In addition, the transparent conductive film 1 which concerns on embodiment of this invention may equip the surface of the hard-coat layer 4 with another functional layer. Examples of other functional layers include an antireflection layer and an antifouling layer.

  Hereinafter, the present invention will be specifically described based on examples.

  First, as shown in FIG. 1, a PET film having a thickness of 100 μm was used for the transparent base material 2 of the transparent conductive film 1.

Next, the cushion layer 3 was formed on one surface on the transparent substrate 2. The cushion layer 3 is manufactured by Shin-Nakamura Chemical Co., Ltd., 100 parts by weight of urethane acrylate represented by the trade name “U-2PPA”, manufactured by Ciba Specialty Chemicals, 5 parts by weight of Irgacure 907, manufactured by Junsei Chemical Co., Ltd. A coating solution in which 100 parts by weight of methyl ethyl ketone was stirred and mixed was applied by a bar coating method to a cured film thickness of 10 μm, dried, and semi-cured by irradiation with 40 mJ / cm ² ultraviolet rays.

Next, the hard coat layer 4 was formed on the cushion layer 3. The hard coat layer 4 is manufactured by Nippon Synthetic Chemical Co., Ltd., 100 parts by weight of urethane acrylate represented by the trade name “1700B”, manufactured by Ciba Specialty Chemicals, 3 parts by weight of Irgacure 184, manufactured by Ciba Specialty Chemicals, Darocur TPO 2 parts by weight, manufactured by Junsei Chemical Co., Ltd., 100 parts by weight of methyl ethyl ketone, stirred and mixed, the coating solution was applied by a bar coating method to a cured film thickness of 5 μm, dried, and irradiated with 400 mJ / cm ² ultraviolet rays. Formed.

  Next, the adhesion layer 5 was formed on the other surface of the transparent substrate 2 (the side opposite to the cushion layer 3). The adhesion layer 5 was formed by forming a film using silicon oxide by a direct current magnetron sputtering method.

  Next, a first transparent conductive film 6 was formed on the adhesion layer 5. The first transparent conductive film 6 was formed by forming a film by direct current magnetron sputtering using ITO which is a mixed oxide of indium oxide and tin oxide.

[Comparative Example 1]
As shown in FIG. 2, the first transparent conductive film 6 is the same as in Example 1 except that the first transparent conductive film 6 is formed directly on the other surface of the transparent substrate 2 (on the side opposite to the cushion layer 3). Thus, a transparent conductive film 1 was formed.

[Comparative Example 2]
First, as shown in FIG. 3, a PET film having a thickness of 100 μm was used for the transparent base material 2 of the transparent conductive film 1.

Next, the hard coat layer 4 was formed on one surface of the transparent substrate 2. The hard coat layer 4 is manufactured by Nippon Synthetic Chemical Co., Ltd., 100 parts by weight of urethane acrylate represented by the trade name “1700B”, manufactured by Ciba Specialty Chemicals, 3 parts by weight of Irgacure 184, manufactured by Ciba Specialty Chemicals, Darocur TPO 2 parts by weight, manufactured by Junsei Chemical Co., Ltd., 100 parts by weight of methyl ethyl ketone, stirred and mixed, the coating solution was applied to a cured film thickness of 15 μm by the bar coating method, dried, and irradiated with 400 mJ / cm ² ultraviolet rays. Formed.

  Next, a first transparent conductive film 6 was formed on the other surface of the transparent substrate 2 (on the side opposite to the hard coat layer 4). The first transparent conductive film 6 was formed by forming a film by direct current magnetron sputtering using ITO which is a mixed oxide of indium oxide and tin oxide.

  Using the transparent conductive film 1 formed in the above examples and comparative examples, as shown in FIG. 4, a touch panel 11 was formed, and pen writing durability was evaluated. The pen 10 is a pen with a pen tip radius of 0.8 mm made of polyacetal, weighted by 220 g from the top surface of the hard coat layer 4 with a plotter, and written 100,000 katakana characters from A to N. And the ratio R / Ro between the resistance value Ro before pen writing and the resistance value R after pen writing was evaluated. The results are shown in Table 1.

  Using the transparent conductive film 1 formed according to the above examples and comparative examples, as shown in FIG. 4, a touch panel 11 was formed, and bending durability was evaluated. For bending durability, with a transparent conductive film on the outside, a cylindrical bar with a diameter of 5 mm was subjected to a load of 200 g and rested for 1 minute, then returned to its original state and measured for a resistance value R. Evaluation was performed using the value of the ratio R / Ro. The results are shown in Table 1.

  From the result shown in Table 1, the transparent conductive film 1 of the structure of Example 1 and Comparative Example 1 which has a layer with cushioning properties is excellent in pen-writing durability compared with Comparative Example 2 without a layer with cushioning properties. You can see that In addition, Example 1 having the adhesion layer 5 was superior in bending durability as compared with Comparative Example 1 and Comparative Example 2 having no adhesion layer 5, and was able to improve flexibility.

It is a schematic sectional drawing which shows the transparent conductive film which concerns on embodiment of this invention. 2 is a schematic cross-sectional view showing a transparent conductive film of Comparative Example 1. FIG. It is a schematic sectional drawing which shows the transparent conductive film of the comparative example 2. It is a schematic sectional drawing which shows the touchscreen which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent conductive film 2 Transparent base material 3 Cushion layer 4 Hard-coat layer 5 Adhesion layer 6 1st transparent conductive film 7 2nd transparent conductive film 8 Board | substrate 9 Spacer 10 Pen 11 Touch panel

Claims (8)

A transparent substrate;
A cushion layer formed on one surface of the transparent substrate;
A hard coat layer formed on the cushion layer;
An adhesion layer formed on the other surface of the transparent substrate;
A first transparent conductive film formed on the adhesion layer;
A transparent conductive film comprising:   The transparent conductive film according to claim 1, wherein the adhesion layer has a thickness of 5 nm to 15 nm. The elastic modulus of the cushion layer is 1 × 10 ⁴ N / m ² or more and 1 × 10 ⁶ N / m ² or less, and the thickness of the cushion layer is 1 μm or more and 50 μm or less. The transparent conductive film as described.   The transparent conductive film according to claim 1, wherein the first transparent conductive film has a thickness of 5 nm to 50 nm. A transparent substrate;
A cushion layer formed on one surface of the transparent substrate;
A hard coat layer formed on the cushion layer;
An adhesion layer formed on the other surface of the transparent substrate;
A first transparent conductive film formed on the adhesion layer;
A second transparent conductive film disposed opposite to the first transparent conductive film via a spacer;
A touch panel comprising:   The touch panel according to claim 5, wherein the adhesion layer has a thickness of 5 nm to 15 nm. 6. The elastic coefficient of the cushion layer is 1 × 10 ⁴ N / m ² or more and 1 × 10 ⁶ N / m ² or less, and the thickness of the cushion layer is 1 μm or more and 50 μm or less. The touch panel described.   The touch panel according to claim 5, wherein the first transparent conductive film has a thickness of 5 nm to 50 nm.

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