JP6738448B1 - Transparent conductive film and touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To pattern a transparent conductive layer on a transparent film, wherein the transparent film containing a cyclic olefin resin is formed on a substrate containing a cyclic olefin resin via an adhesive layer. Provided is a transparent conductive film in which deterioration of visibility when used in a touch panel is suppressed.
[Solution]
At least a transparent conductive layer, a transparent film containing a cyclic olefin-based resin, an adhesive layer, and a substrate containing a cyclic olefin-based resin is a transparent conductive film laminated in this order,
The adhesive layer is releasably laminated from the transparent film,
The ratio of the thickness of the base material to the thickness of the transparent film (thickness of the base material/thickness of the transparent film) is 1.0 or more,
The thickness of the substrate is 40 to 200 μm,
A transparent conductive film in which the peeling force of the adhesive layer from the transparent film is 0.02 N/25 mm or more.
[Selection diagram] None

Description

The present invention relates to a transparent conductive film and a touch panel.

Conventionally, a touch panel for detecting an input position using a transparent conductive film is known. Various configurations of this touch panel have been conventionally studied, but an electrostatic capacitance type touch panel is known as an example.

For example, the touch panel disclosed in Patent Document 1 is configured such that a dielectric layer is interposed between a pair of transparent conductive films each having a transparent conductive layer having a predetermined pattern shape, and a finger or the like is operated. When the surface is touched, the touch position can be detected by utilizing the change in the electrostatic capacitance caused by being grounded via the human body.

JP, 2003-173238, A JP2012-66477A JP-A-7-068690

As a base material for a touch panel, it is known to use a base material sheet formed of a cyclic olefin resin such as a thermoplastic norbornene resin having optical isotropy (see, for example, Patent Document 2). Further, for example, in Patent Document 3, when a substrate film is laminated on a surface opposite to a surface on which a transparent electrode is formed and processed, the transparent electrode film is continuously processed without damage in a heating step. Describes a technique for reducing the difference in linear expansion coefficient between the base film and the transparent electrode film.

On the other hand, conventionally, a transparent conductive film used for a touch panel is manufactured as follows, for example.

First, a transparent conductive layer made of a conductive material such as indium tin oxide (ITO) is formed on one surface of the transparent film by using a film forming technique such as a sputtering method or a vacuum deposition method. Next, a resist material is applied (printed) on the surface of the transparent conductive layer in a predetermined patterning shape by a screen printing method or the like and then cured to form a resist film (protective film). The applied resist is usually dried or cured by heating, or an ultraviolet curing method using a metal halide lamp or the like. Then, the transparent conductive film and the transparent substrate on which the resist film having a predetermined pattern shape is formed are dipped in an etching solution such as an acid solution for a predetermined time, so that the conductive film portion not exposed by the resist film (exposed After removing the (part), the resist film is peeled or dissolved with an alkaline solution or the like to obtain a conductive film in which a transparent conductor having a predetermined pattern shape is formed on one surface of the transparent substrate.

However, when the transparent film is made of a material containing a transparent resin, patterning is performed in the step of curing the resist applied on the transparent conductive layer formed on the surface of the transparent film, or in the heating step after the patterning of the transparent conductive layer. The difference in the degree of shrinkage of the transparent film due to heat between the pattern part and the non-patterning part causes undulations on the surface of the transparent conductive film, and there is a step (pattern irregularity) particularly near the boundary between the patterning part and the non-patterning part. There is a problem that the pattern shape is visually recognized and the visibility of the touch panel is deteriorated.

As a result of studies by the present inventors, a decrease in visibility due to such unevenness of the transparent film is caused by a transparent film containing a cyclic olefin resin on a substrate containing a cyclic olefin resin via an adhesive layer. It has been revealed that in the transparent conductive film formed in step 1, when a transparent conductive layer is patterned on the transparent film, it occurs remarkably.

Further, in the touch panel, a cover member such as a cover glass is laminated on the transparent conductive layer of the transparent film via a transparent adhesive sheet to protect the transparent conductive layer. When laminating the cover member, in the transparent conductive film, a void is formed between the transparent conductive layer and the transparent pressure-sensitive adhesive sheet formed in a pattern, and the pattern of the transparent conductive layer is visually recognized, A problem was also found that the visibility of the touch panel deteriorates.

Under such circumstances, the present invention provides a transparent film containing a cyclic olefin resin, a transparent conductive film formed on a base material containing a cyclic olefin resin via an adhesive layer, on a transparent film. The main purpose of the present invention is to provide a transparent conductive film in which deterioration of visibility when used in a touch panel is suppressed by patterning the transparent conductive layer. Another object of the present invention is to provide a touch panel using the transparent conductive film.

The present inventor has conducted extensive studies in order to solve the above-mentioned problems of the conventional technology. As a result, at least a transparent conductive layer, a transparent film containing a cyclic olefin resin, a pressure-sensitive adhesive layer, a substrate containing a cyclic olefin resin is a transparent conductive film laminated in this order, the pressure-sensitive adhesive layer is , Is laminated so as to be peelable from the transparent film, and the ratio of the thickness of the base material to the thickness of the transparent film (the thickness of the base material/the thickness of the transparent film) is set to a predetermined value or more, and the thickness of the base material is set to a predetermined range. By setting the peeling force from the transparent film of the adhesive layer to a predetermined value or more, the visibility of the touch panel is deteriorated due to the unevenness due to the patterning of the transparent conductive layer, and the transparent conductive layer formed when the cover member is laminated. It was found that the deterioration of the visibility of the touch panel due to the gap between the transparent adhesive sheet and the transparent adhesive sheet is effectively suppressed. The present invention is an invention completed through further studies based on such findings.

That is, the present invention provides the inventions of the following modes.
Item 1. At least a transparent conductive layer, a transparent film containing a cyclic olefin-based resin, an adhesive layer, and a substrate containing a cyclic olefin-based resin is a transparent conductive film laminated in this order,
The adhesive layer is releasably laminated from the transparent film,
The ratio of the thickness of the base material to the thickness of the transparent film (thickness of the base material/thickness of the transparent film) is 1.0 or more,
The thickness of the substrate is 40 to 200 μm,
A transparent conductive film in which the peeling force of the adhesive layer from the transparent film is 0.02 N/25 mm or more.
Item 2. Item 2. The transparent conductive film according to Item 1, wherein the peeling force of the adhesive layer from the transparent film is 0.03 to 1.0 N/25 mm.
Item 3. Item 3. A touch panel comprising at least a transparent adhesive sheet and a cover member laminated in this order on the transparent conductive layer of the transparent conductive film according to Item 1 or 2.

According to the present invention, it is possible to provide a transparent conductive film in which deterioration of visibility when used for a touch panel is effectively suppressed. Further, according to the present invention, it is possible to provide a touch panel using the transparent conductive film.

It is a schematic diagram of a transparent conductive film. It is a schematic diagram of a touch panel with a substrate. It is a schematic diagram of a touch panel.

The transparent conductive film of the present invention includes at least a transparent conductive layer, a transparent film containing a cyclic olefin-based resin (hereinafter sometimes simply referred to as “transparent film”), an adhesive layer, and a group containing a cyclic olefin-based resin. A material (hereinafter sometimes simply referred to as “base material”) is a transparent conductive film laminated in this order. In the transparent conductive film of the present invention, the adhesive layer is laminated so as to be peelable from the transparent film, and the ratio of the thickness of the base material to the thickness of the transparent film (thickness of the base material/thickness of the transparent film) is , 1.0 or more, the thickness of the substrate is 40 to 200 μm, and the peeling force of the adhesive layer from the transparent film is 0.02 N/25 mm or more. The transparent conductive film of the present invention satisfies all of these constitutions, so that a transparent film containing a cyclic olefin resin is formed on a substrate containing a cyclic olefin resin via an adhesive layer. In the transparent conductive film, when the transparent conductive layer on the transparent film is patterned, deterioration of visibility when used in a touch panel is suppressed.

Hereinafter, the transparent conductive film of the present invention and the touch panel using the same will be described in detail.

In addition, in this specification, the numerical value connected by "-" means the numerical range which includes the numerical value before and behind "-" as a lower limit and an upper limit. When a plurality of lower limit values and a plurality of upper limit values are described separately, arbitrary lower limit values and upper limit values can be selected and connected by "...".

1. Transparent Conductive Film As shown in the schematic view of FIG. 1, the transparent conductive film 10 of the present invention includes at least a transparent conductive layer 4, a transparent film 1 containing a cyclic olefin resin, an adhesive layer 2, and a cyclic olefin. A base material 3 containing a system resin is a transparent conductive film laminated in this order. In the schematic view of FIG. 1, the transparent conductive layer 4 is laminated on the transparent film 1 in a pattern (partially), but in the state of the transparent conductive film 10, the transparent conductive layer 4 is formed. May be formed on the entire surface of the transparent film 1, and the transparent conductive layer 4 may be formed in a pattern when applied to the touch panel. Further, the transparent conductive layer 4 may be formed in a pattern in the state of the transparent conductive film 10.

As described above, the transparent conductive layer 4 is a layer arranged on the surface of the transparent film 1 opposite to the adhesive layer 2 side, and when the transparent conductive film 10 of the present invention is applied to a touch panel. , Patterned into a predetermined shape. The patterning of the transparent conductive layer 4 is not particularly limited, and the patterning of the transparent conductive layer 4 applied to a known touch panel can be adopted. That is, the pattern shape of the transparent conductive layer 4 can be any shape as long as the contact point of a finger or the like can be detected.

For example, the transparent conductive layer 4 can be formed as an assembly of a plurality of strip-shaped conductive portions extending in parallel on the surface of the transparent film 1, and the strip-shaped conductive portions of each transparent conductive layer 4 can be formed when a touch panel is formed. Moreover, in a plan view, the strip-shaped conductive portions can be arranged so that their longitudinal directions are orthogonal to each other. Further, the transparent conductive layer 4 can be connected to an external drive circuit through a routing circuit made of conductive ink or the like.

Examples of the material forming the transparent conductive layer 4 include indium tin oxide (ITO), indium oxide, antimony-added tin oxide, fluorine-added tin oxide, aluminum-added zinc oxide, gallium-added zinc oxide, silicon-added zinc oxide, and zinc oxide. -Tin oxide type, indium oxide-tin oxide type, zinc oxide-indium oxide-magnesium oxide type, zinc oxide, transparent conductive material such as tin oxide film, or metal material such as tin, copper, aluminum, nickel, chromium, A metal oxide material can be given as an example, and a combination of two or more of these may be formed.

Further, as a material for forming the transparent conductive layer 4, ultrafine conductive carbon fibers such as carbon nanotubes, carbon nanohorns, carbon nanowires, carbon nanofibers, and graphite fibrils, and ultrafine metal fibers such as silver nanowires are dispersed in a polymer material. It is also possible to use a composite material or a conductive polymer material.

The method for forming the transparent conductive layer 4 is not particularly limited, and a known method capable of forming a transparent conductive layer having a predetermined thickness on the surface of the transparent film 1 can be adopted. Examples of the method for forming the transparent conductive layer 4 include PVD methods such as a sputtering method, a vacuum vapor deposition method, an ion plating method, a CVD method, a coating method, and a printing method.

Although the thickness of the transparent conductive layer 4 varies depending on the material, it is preferably about 1 nm to 100 nm, more preferably about 10 to 50 nm.

Further, as a method of patterning the transparent conductive layer 4, a known method can be used, for example, a mask portion having a desired pattern shape is formed on the surface of the transparent conductive layer 4 formed on the entire surface of the transparent film 1. Then, the exposed portion is removed by etching with an acid solution or the like, and then the mask portion is dissolved with an alkali solution or the like. Further, the transparent conductive layer 4 may be patterned by photolithography.

The transparent film 1 is a layer located between the transparent conductive layer 4 and the adhesive layer 2. The transparent film 1 is not particularly limited and, for example, a known film such as an optical film used for an input device such as a liquid crystal display device, an EL display device, a touch panel can be used.

The cyclic olefin-based resin contained in the transparent film 1 is a polymer compound having a main chain composed of carbon-carbon bonds and having a cyclic hydrocarbon structure in at least a part of the main chain. This cyclic hydrocarbon structure is introduced by using a compound (cyclic olefin) having at least one olefinic double bond in the cyclic hydrocarbon structure, as represented by norbornene or tetracyclododecene, as a monomer. To be done.

The cyclic olefin-based resin is produced from the production method thereof by the addition (co)polymer of a cyclic olefin or its hydrogenated product, the addition copolymer of a cyclic olefin and an α-olefin or its hydrogenated product, and the ring-opening (co ) Polymers or hydrogenated products thereof.

Examples of the cyclic olefin include a monocyclic cyclic olefin such as cyclopentene, cyclohexene, cyclooctene, cyclopentadiene, and 1,3-cyclohexadiene, and other polycyclic cyclic olefins, which may be used alone or in combination of two or more kinds. be able to. In particular, it is preferable to use bicyclo[2.2.1]hept-2-ene (conventional name: norbornene) alone.

Specific examples of the α-olefin copolymerizable with the cyclic olefin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene and 3 Examples thereof include ethylene or α-olefin having 2 to 20 carbon atoms, preferably 2 to 8 carbon atoms such as -ethyl-1-pentene and 4-methyl-1-pentene. These α-olefins may be used alone or in combination of two or more, but ethylene is preferably used alone.

Among the above-mentioned cyclic olefin resins, the addition copolymer of cyclic olefin and α-olefin or its hydrogenated product has a good balance of properties and cost. Among them, the cyclic olefin resin, which is a copolymer of norbornene and ethylene, is particularly preferable because the ratio of norbornene and ethylene can be easily adjusted and the glass transition point (Tg) can be easily adjusted by the ratio.

The cyclic olefin-based resin may contain other copolymerizable unsaturated monomer components within a range that does not impair the properties thereof. If necessary, a thermoplastic resin, an inorganic or organic filler, various compounding agents and the like may be contained.

The method for producing the cyclic olefin resin is not particularly limited, for example, a monomer composition containing a cyclic olefin and α-olefin is introduced into a reactor, a polymerization catalyst and a polymerization solvent are added thereto, and a predetermined reaction temperature and a reaction A method of reacting under pressure to obtain a polymerization solution and then removing the solvent can be mentioned. The reaction temperature and the reaction pressure can be appropriately set so that the content ratio of the cyclic olefin and the α-olefin in the resin is within a desired range.

As commercially available cyclic olefin resins, TOPAS (manufactured by Polyplastics Co., Ltd.), Apel (manufactured by Mitsui Chemicals, Inc.), Zeonex (manufactured by Nippon Zeon Co., Ltd.), Zeonoa (manufactured by Nippon Zeon Co., Ltd.), Arton (Japan Synthetic Rubber Co., Ltd.) Manufactured). Among them, TOPAS6017S-04 and the like can be exemplified as the cyclic olefin resin having a glass transition point (Tg) of 170° C. or higher.

In addition to the cyclic olefin resin, the transparent film 1 may further contain a styrene elastomer described later.

The thickness of the transparent film 1 is not particularly limited as long as the ratio of the thickness of the base material 3 to the thickness of the transparent film 1 is 1.0 or more, but the deterioration of visibility when used in a touch panel is more preferable. From the viewpoint of suppressing more effectively, the thickness is preferably 10 to 100 μm, more preferably 13 to 50 μm, and further preferably 23 to 40 μm.

The adhesive layer 2 is composed of a transparent adhesive. The adhesive layer 2 is a layer for adhering the base material 3 described below so that the base material 3 can be peeled from the transparent film 1.

In the transparent conductive film 10 of the present invention, the peeling force of the adhesive layer 2 from the transparent film 1 is set to 0.02 N/25 mm or more. As the peeling force, the lower limit is preferably 0.03 N/25 mm or more, and 0.05 N/25 mm or more, from the viewpoint of more effectively suppressing deterioration of visibility when used in a touch panel. More preferably. The upper limit is preferably 2.5 N/25 mm or less, more preferably 1.00 N/25 mm or less, and further preferably 0.70 N/25 mm or less. When the peeling force is 0.02 N/25 mm or more, pattern unevenness, which is a problem that occurs in the heating step after patterning the transparent conductive layer, can be suppressed, and the peeling force is 2.5 N/25 mm or less. Thus, it is possible to preferably suppress the formation of voids between the transparent conductive layer formed in a pattern and the transparent pressure-sensitive adhesive sheet, which is a problem that occurs when the cover member is laminated on the transparent conductive film.

In the measurement of the peeling force, a transparent conductive film is used as a test piece, the interface between the adhesive layer and the transparent film is peeled off, and the peeling force is measured. The measurement environment is 23° C., and the adhesive force (N/25 mm) at 180° (peeling angle) is measured under the conditions of a pulling speed of 0.3 m/min and a pulling speed of 10 m/min to obtain the peeling force. The size of the test piece is 25 mm in the width direction and 200 mm in the length direction, and the adhesive force is measured in the length direction (direction in which the adhesive layer and the substrate are separated from the transparent conductive film). As a device for detecting the peeling speed, a commercially available peeling tester (for example, HEIDON-17 (manufactured by Shinto Kagaku)) is used.

As the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer 2, known ones can be used as long as the peeling force of the pressure-sensitive adhesive layer 2 from the transparent film 1 reaches the above value, and examples thereof include an acrylic polymer and silicone. Appropriately select a base polymer made of polymer such as polymer, polyester, polyurethane, polyamide, polyvinyl ether, vinyl acetate/vinyl chloride copolymer, modified polyolefin, epoxy system, fluorine system, rubber system such as natural rubber and synthetic rubber. Can be used. In particular, an acrylic pressure-sensitive adhesive is preferably used because it is excellent in optical transparency, exhibits appropriate wettability, cohesiveness, adhesiveness and other adhesive properties, and is also excellent in weather resistance and heat resistance.

The method for forming the pressure-sensitive adhesive layer 2 is not particularly limited, and a method of applying the pressure-sensitive adhesive composition to a release liner, drying and then transferring to the base material 3 (transfer method), or directly applying the pressure-sensitive adhesive composition to the base material 3. Examples thereof include coating and drying methods (direct copying method) and coextrusion methods. As the pressure-sensitive adhesive, a tackifier, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a silane coupling agent, or the like can be appropriately used as necessary.

The thickness of the adhesive layer 2 is not particularly limited, but is preferably 5 to 100 μm, more preferably 10 to 50 μm from the viewpoint of more effectively suppressing deterioration of visibility when used in a touch panel. , And more preferably 15 to 35 μm.

In the transparent conductive film 10, the base material 3 is a peelable base material that is laminated on the transparent film 1 via the adhesive layer 2 and is used to protect the transparent film 1. Specifically, the base material 3 is used to protect the transparent film 1 in the process of producing a transparent conductive film containing a cyclic olefin resin, a distribution process, and the like, and is a laminate of the transparent conductive layer 4 and the transparent film 1. When used as a touch panel, it is peeled off from the transparent conductive film 10 together with the adhesive layer 2.

The base material 3 contains a cyclic olefin resin. The cyclic olefin-based resin contained in the base material 3 may be one type or two or more types, respectively.

The base material 3 is laminated on the transparent film 1 containing a cyclic olefin resin and is used to protect the transparent film 1. Therefore, the base material 3 needs to contain a cyclic olefin resin. By containing the cyclic olefin-based resin in the base material 3, in the transparent conductive film 10 laminated with the transparent film 1 containing the cyclic olefin-based resin, the physical properties such as the heat shrinkage rate of the base material 3 and the transparent film 1 are improved. In the same manner, the occurrence of defects during manufacturing (for example, curling due to the difference in heat shrinkage) is suppressed.

The cyclic olefin-based resin contained in the base material 3 is not particularly limited and, for example, the same cyclic olefin-based resin as the transparent film 1 is exemplified. In addition to the cyclic olefin resin, the base material 3 may further contain a styrene elastomer.

The styrene-based elastomer is a copolymer of styrene and a conjugated diene such as butadiene or isoprene, and/or a hydrogenated product thereof. The styrene-based elastomer is a block copolymer in which styrene is a hard segment and conjugated diene is a soft segment, and the vulcanization step is unnecessary, and is preferably used. Further, hydrogenated ones have high thermal stability and are more preferable.

Examples of the styrene elastomer include styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-isoprene-butadiene-styrene block copolymer ( SIBS), styrene-ethylene-ethylene-propylene-styrene copolymer (SEEPS) and the like.

The styrene-based elastomer used in the present invention preferably has a small difference in refractive index from the cyclic olefin-based resin in terms of transparency. Specifically, the difference in refractive index is within ±0.02, more preferably ±0.015. It is preferably within.

In the base material 3, the styrene content in the styrene-based elastomer is preferably 15% by mass or more, and 30% by mass, from the viewpoint of more effectively suppressing deterioration of visibility when used in a touch panel. It is more preferably at least 50% by mass, further preferably at least 50% by mass.

In the base material 3, the content of the styrene-based elastomer in the base material 3 is 0.1% by mass or more from the viewpoint of more effectively suppressing deterioration of visibility when used in a touch panel. The content is preferably 0.5% by mass or more, more preferably 1% by mass or more. Further, the content of the styrene elastomer is preferably less than 20% by mass, more preferably 15% by mass or less, and further preferably 10% by mass or less. In the base material 3, it is particularly preferable that the content of the styrene-based elastomer having a styrene content of 15% by mass or more, further 30% by mass or more, further 50% by mass or more satisfies these contents. ..

In addition to the cyclic olefin-based resin and the styrene-based elastomer, various additives may be added to the base material 3 as needed, as long as the characteristics thereof are not impaired. The various compounding agents are not particularly limited as long as they are used in optical films and the like, and examples thereof include antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, lubricants, antistatic agents, flame retardants, and dyes. And coloring agents such as pigments, near-infrared absorbing agents, compounding agents such as fluorescent whitening agents, and fillers.

The base material 3 may be colorless and transparent or colored and transparent.

The base material 3 has a thickness of 40 to 200 μm. The thickness of the base material 3 is preferably 50 to 200 μm from the viewpoint of more effectively suppressing deterioration of visibility when used in a touch panel.

In the transparent conductive film of the present invention, the ratio of the thickness of the base material 3 to the thickness of the transparent film 1 (thickness of the base material 3/thickness of the transparent film 1) is 1.0 or more. From the viewpoint of more effectively suppressing the deterioration of visibility when used in a touch panel, the lower limit of the ratio is preferably 1.1 or more, more preferably 1.2 or more. From the viewpoint of productivity, the upper limit value is preferably 5.0 or less, more preferably 4.5 or less, still more preferably 4.0 or less.

The base material 3 can be formed using a resin composition containing a cyclic olefin resin. Specifically, a polymerization solution of a cyclic olefin-based resin (optionally further containing a styrene-based elastomer) is prepared, and the solvent is removed under high temperature and reduced pressure conditions to obtain a molten mixture. The mixture is extruded to produce pellets. Then, using this pellet, the base material 3 having a predetermined thickness, preferably 20 to 300 μm, can be molded by the T-die method or the calender method. However, the manufacturing method is not limited to this, and for example, the pellets may be manufactured after melt-kneading and adding the cyclic olefin-based resin.

The base material 3 is preferably formed by biaxial stretching of the resin composition. In the biaxial stretching, for example, it is formed by stretching an unstretched film of the resin composition in MD (machine direction) and TD (direction orthogonal to MD). By biaxially stretching, the toughness is higher than that of the unstretched substrate 3, and cracking of the film alone can be suppressed.

Further, a hard coat layer may be further laminated on the side of the base material 3 opposite to the adhesive layer 2. The Martens hardness of the hard coat layer is preferably 150 to 220 N/mm ² . Since the Martens hardness is 150 N/mm ² , the effect of suppressing scratches on the substrate 3 can be enhanced, and the Martens hardness of 220 N/mm ² suppresses cracking of the hard coat layer. You can

The material forming the hard coat layer is not particularly limited as long as it can protect the base material 3, and examples thereof include an acrylic material.

The thickness of the hard coat layer is not particularly limited, but is preferably about 1 to 5 μm.

2. Touch Panel As shown in the schematic view of FIG. 3, the touch panel 21 of the present invention is a base material in which at least a transparent adhesive sheet 5 and a cover member 6 are laminated in this order on the transparent conductive layer of the transparent conductive film 10. The adhesive layer 2 and the base material 3 are peeled off from the attached touch panel 20 (see FIG. 2 ). That is, of the touch panels, the touch panel 20 with the base material is before the adhesive layer 2 and the base material 3 are peeled off, and the touch panel 21 is the touch panel 21 with the adhesive layer 2 and the base material 3 peeled off. It is a thing.

The details of the transparent conductive film 10 are as described in the section “1. Transparent conductive film”. As described above, in the touch panel 21, the transparent conductive layer 4 is patterned into a predetermined shape.

The transparent adhesive sheet 5 is an adhesive transparent sheet formed so as to cover the transparent conductive layer 4 formed in a pattern, and includes a cover member 6 of the touch panel, a transparent conductive layer 4 and a laminated body of the transparent film 1. Is a layer provided for adhering.

The material forming the transparent adhesive sheet 5 is not particularly limited as long as it is used for bonding the cover member of the touch panel and the transparent conductive layer, and examples thereof include an acrylic material.

The thickness of the transparent adhesive sheet 5 is not particularly limited, but is preferably about 10 to 200 μm, more preferably about 20 to 150 μm.

The material forming the cover member 6 is not particularly limited, and materials used for known touch panels can be used, and examples thereof include glass and resin. The cover member made of glass is cover glass, and the cover member made of resin is cover resin. As the resin that constitutes the cover resin, for example, polycarbonate, acrylic resin, and a laminate of these are generally used, and are suitable for the present invention.

The thickness of the cover member 6 is not particularly limited, but is preferably about 0.05 to 2.0 mm, more preferably about 0.1 to 1.5 mm.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

Example 1-5 and Comparative Example 1-4
<Production of transparent conductive film>
Using a φ32 mm single screw extruder, cycloolefin copolymer (manufactured by Polyplastics Co., Ltd.) as cyclic olefin resin, Septon series (manufactured by Kuraray Co., Ltd., styrene content 60 mass%) as styrene elastomer, While kneading the content to be 10% by mass (screw rotation speed 150 rpm), extruding from a coat hanger die (300 mm width, gap 1.3 mm) (extrusion temperature 310° C., discharge rate 20 kg/hr), roll The base material having the thickness shown in Table 2 was obtained.

On the obtained base material, a resin composition for forming an adhesive layer containing the components shown in Table 1 with an adhesive, an additive and a cross-linking agent is used, and the thickness of the adhesive layer becomes a value shown in Table 2. In this way, one side of the base material was coated using a wire bar coater. Next, the resin composition for forming an adhesive layer on the substrate is heat-treated at 80° C. for 2 to 5 minutes to dry the diluting solvent contained in the resin composition for forming an adhesive layer, and then a UV irradiation device ( The adhesive layer was formed on one surface of the base material by curing with an integrated light amount of 200 mJ/cm ² using Heraeus Co., Ltd.).

Next, a transparent film with a transparent conductive layer (thickness shown in Table 2) in which a conductive layer (ITO) is laminated on a transparent film (cycloolefin-based transparent film) is prepared, and the transparent conductivity of the film is prepared. The surface opposite to the layer was laminated on the pressure-sensitive adhesive layer to obtain a transparent conductive film.

<Manufacture of touch panel with base material>
The obtained transparent conductive film was cut into a 5 cm square. Next, eight polyimide tapes (3 mm width) were attached in parallel to the transparent conductive layer so as to be spaced by 3 mm. Then, the laminated body to which the polyimide tape is attached is immersed in an ITO etching solution (“ITO-06N” manufactured by Kanto Chemical Co., Inc.) for 1 minute to remove the transparent conductive layer in the portion to which the polyimide tape is not attached, and rinse and By peeling the polyimide tape after drying, the transparent conductive layer of the transparent conductive film was patterned. Next, after leaving the patterned transparent conductive film for 1 hour at 150° C., a transparent adhesive sheet (NNEA0M manufactured by Gunze Co., thickness 100 μm) and a cover glass (thickness 700 μm) were placed on the transparent conductive layer. By sequentially stacking and pressing from the cover glass, a base material/adhesive layer/transparent film/patterned transparent conductive layer/transparent adhesive sheet/cover glass were laminated in that order to obtain a touch panel with a base material. ..

<Measurement of peeling force>
Using the transparent conductive film obtained above as a test piece, the interface between the adhesive layer and the transparent film was peeled off, and the peeling force was measured. The measurement environment was 23° C., and the adhesive force (N/25 mm) at 180° (peeling angle) was measured under the conditions of a pulling speed of 0.3 m/min and a pulling speed of 10 m/min to obtain the peeling force. The test piece had a size of 25 mm in the width direction and 200 mm in the longitudinal direction, and the adhesive strength was measured in the longitudinal direction (the direction in which the adhesive layer and the base material are separated from the transparent conductive film). A peeling tester HEIDON-17 (manufactured by Shinto Chemical Co., Ltd.) was used as a device for detecting the peeling speed. The results are shown in Table 2.

<Visibility evaluation>
The touch panel with a substrate obtained as described above was used as a test piece, and the cover glass of the test piece was placed on the upper side of a white sheet. Next, the test piece was visually observed from the cover glass side, and the visibility was evaluated according to the following criteria. The results are shown in Table 2.
◎: The pattern of the transparent conductive layer is not visible at all ○: The pattern irregularities of the transparent conductive layer are visible, but there is no problem in practical use ×: The pattern of the transparent conductive layer is visible

1 Transparent Film 2 Adhesive Layer 3 Base Material 4 Transparent Conductive Layer 5 Transparent Adhesive Sheet 6 Cover Member 10 Transparent Conductive Film 20 Touch Panel with Base Material 21 Touch Panel

Claims (3)

At least, a transparent conductive layer, a transparent fill beam formed by the cyclic olefin-based resin, and an adhesive layer, a transparent conductive film and the substrate are laminated in this order, including a cyclic olefin resin,
In the transparent conductive film, the transparent conductive layer is laminated only on one side of the transparent film,
The adhesive layer is releasably laminated from the transparent film,
The ratio of the thickness of the base material to the thickness of the transparent film (thickness of the base material/thickness of the transparent film) is 1.0 or more,
The thickness of the substrate is 40 to 200 μm,
A transparent conductive film in which the peeling force of the adhesive layer from the transparent film is 0.02 N/25 mm or more. The transparent conductive film according to claim 1, wherein a peeling force of the adhesive layer from the transparent film is 0.03 to 1.0 N/25 mm. A touch panel, wherein at least a transparent adhesive sheet and a cover member are laminated in this order on the transparent conductive layer of the transparent conductive film according to claim 1.