KR20190018412A - Transparent conductive film and touch panel - Google Patents

Abstract

The transparent conductive film comprises a transparent resin film, a cured resin layer and a transparent conductive layer in this order, and the cured resin layer is a cured product film obtained by curing a resin composition containing an epoxy resin having a weight average molecular weight of 3000 or more.

Description

Transparent conductive film and touch panel

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

Conventionally, it is known that an image display device is provided with a film for a touch panel in which a transparent wiring layer made of indium tin composite oxide (ITO) or the like is formed. The film for a touch panel is generally produced by patterning an ITO layer in a wiring pattern in a transparent conductive film in which an ITO layer is laminated on a transparent substrate. Further, in applications such as smart phones and tablets, a transparent resin film such as a plastic film is used as a transparent substrate in terms of thinness and weight.

As such a transparent conductive film, there is proposed a transparent conductive film having a transparent conductive layer (ITO layer) patterned (patterned) on at least one surface of a transparent resin film with a cured resin layer interposed therebetween. Patent Document 1 discloses such a transparent conductive film.

Japanese Laid-Open Patent Publication No. 2009-76432

However, in the case of the transparent conductive film, cracks are generated on the surface of the transparent conductive film at the time of carrying or patterning, and the cracks are visually seen in white.

As a result of the investigation by the inventors of the present invention, it has been found that the interface between the transparent resin film and the cured resin layer is peeled off and the cured resin layer is deformed to be distorted or bulged with respect to the transparent resin film. I could not follow it and found out that there was a crack.

Further, the transparent conductive film is connected to the flexible wiring circuit substrate at its end portion, and a dynamic load is applied to the connection portion. As a result, the interface between the transparent resin film and the cured resin layer or the transparent conductive layer may be peeled off.

Therefore, a transparent conductive film having good adhesion between the transparent resin film and the cured resin layer is desired.

An object of the present invention is to provide a transparent conductive film excellent in adhesion between a transparent resin film and a cured resin layer and a touch panel comprising the transparent conductive film.

The present invention [1] is characterized by comprising a transparent resin film, a cured resin layer and a transparent conductive layer in this order, wherein the cured resin layer is a cured resin film obtained by curing a resin composition containing an epoxy resin having a weight- , And a transparent conductive film.

The present invention [2] includes the transparent conductive film according to [1], wherein the thickness of the cured resin layer is 150 nm or less.

The present invention [3] includes the transparent conductive film described in [1] or [2], wherein the epoxy resin is a rubber-modified epoxy resin.

The present invention [4] includes the transparent conductive film according to any one of [1] to [3], wherein the resin composition contains a curing accelerator and the curing accelerator contains antimony.

The present invention [5] comprises the transparent conductive film according to any one of [1] to [4], wherein the adhesion of the cured resin layer to the transparent resin film is 50 N / 25 mm or more.

The present invention [6] is a transparent conductive layer according to any one of [1] to [5], wherein the transparent conductive layer has a rate of change of surface resistance value before and after being left for 240 hours under an atmosphere of a temperature of 85 캜 and a humidity of 85% And a transparent conductive film.

The present invention [7] includes a touch panel comprising the transparent conductive film according to any one of [1] to [6].

The transparent conductive film of the present invention comprises a transparent resin film, a cured resin layer and a transparent conductive layer in this order, and the cured resin layer is a cured product film obtained by curing a resin composition containing an epoxy resin having a weight- All. Therefore, the adhesion between the transparent resin film and the cured resin layer is excellent. Therefore, it is possible to suppress the occurrence of cracks on the surface of the transparent resin film at the time of carrying, patterning, and the like, and it is possible to suppress peeling at the joint portion when connected to the flexible wiring circuit board.

1 is a cross-sectional view of a first embodiment of a transparent conductive film of the present invention.
Fig. 2 shows a cross-sectional view of a modification of the first embodiment of the transparent conductive film of the present invention (in which the transparent conductive layer is patterned).
Fig. 3 shows a cross-sectional view of a modification of the first embodiment of the transparent conductive film of the present invention (a form in which a transparent substrate is bonded to a transparent resin film).
4 is a cross-sectional view of a second embodiment of the transparent conductive film of the present invention.
Fig. 5 shows a cross-sectional view of a third embodiment of the transparent conductive film of the present invention.
6 is a schematic view of a test for measuring the adhesion of the resin cured layer.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In Fig. 1, the upper and lower direction of the paper surface is the upper side (one side in the thickness direction, one side in the first direction) and the lower side (the other side in the thickness direction, One side in the other direction). The left and right direction of the paper surface and the depth direction are plane directions orthogonal to the vertical direction. Other drawings are the same as in Fig.

≪ First Embodiment >

(Transparent conductive film)

Fig. 1 shows a transparent conductive film 10 which is a first embodiment of the transparent conductive film of the present invention. The transparent conductive film 10 shown in Fig. 1 has a transparent resin film 1, a cured resin layer 2 and a transparent conductive layer 3 in this order. Specifically, the transparent conductive film 10 includes a transparent resin film 1, a cured resin layer 2 disposed on the upper surface (one side in the thickness direction) of the transparent resin film 1, a cured resin layer 2 And a transparent conductive layer 3 disposed on the upper surface of the transparent conductive layer 3. The transparent conductive film 10 is preferably composed of a transparent resin film 1, a cured resin layer 2 and a transparent conductive layer 3.

(Transparent resin film)

The transparent resin film (1) is not particularly limited, but various plastic films having transparency and flexibility are used. For example, the material may be selected from the group consisting of a polyester resin (such as polyethylene terephthalate), an acetate resin, a polyether sulfone resin, a polycarbonate resin, a polyamide resin, a polyimide resin, a polyolefin resin, (Meth) acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, and the like. Preferable examples include polyester resins, polycarbonate resins and polyolefin resins, and polyester resins are more preferred.

The thickness of the transparent resin film 1 is not particularly limited, but is, for example, not less than 5 占 퐉, preferably not less than 20 占 퐉, more preferably not less than 40 占 퐉 and not more than 200 占 퐉, Mu m or less.

The surface of the transparent resin film 1 is subjected to etching treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion and oxidation in advance, The adhesion to the resin film 1 may be further improved. Before forming the cured resin layer 2, it may be damped and cleaned by solvent cleaning, ultrasonic cleaning or the like, if necessary.

(Cured resin layer)

The cured resin layer 2 is a cured resin film in which a resin composition containing an epoxy resin having a weight average molecular weight of 3000 or more (hereinafter, also referred to as " high molecular weight epoxy resin ") is cured. The high molecular weight epoxy resin is preferably a main component of the resin composition. The content of the main component is preferably 20% by weight or more, more preferably 40% by weight or more, more preferably 60% by weight or more based on the total amount of the resin composition Particularly preferred.

As the high molecular weight epoxy resin, those widely used can be used, and an epoxy group-containing compound having one or more, preferably two or more epoxy groups in the molecule such as glycidyl group, alicyclic epoxy group and aliphatic epoxy group can be used have. Specific examples thereof include epoxy resins such as epichlorohydrin-bisphenol A type epoxy resin, epichlorohydrin-bisphenol F type epoxy resin, tetrabromobisphenol A glycidyl ether type epoxy resin, novolak type epoxy resin, Phenol novolak type epoxy resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, glycidyl ether type epoxy resin of bisphenol A propylene oxide adduct, p-oxybenzoic acid-glycidyl ether ester type epoxy resin Aminophenol epoxy resin, diaminodiphenylmethane epoxy resin, alicyclic epoxy resin, N, N-diglycidyl aniline, N, N-diglycidyl-o-toluidine, triglycidyl Glycidyl ethers of polyhydric alcohols (glycerin and the like), hydantoin-type epoxy resins, epoxy group-containing polysiloxanes, unsaturated An epoxy resin having a weight average molecular weight of 3000 or more in an epoxy resin composed of an epoxy resin or the like of a polymer (petroleum resin or the like). The high molecular weight epoxy resin may be used alone, or two or more kinds thereof may be used in combination.

The weight average molecular weight of the high molecular weight epoxy resin may be 3,000 or more, preferably 3300 or more. The upper limit of the weight average molecular weight is preferably 5000, more preferably 4000 from the viewpoint of suppressing the embrittlement caused by excessive curing of the obtained cured resin layer. By setting the weight average molecular weight of the epoxy resin within the above range, the cured resin layer 2 having high adhesion with the transparent resin film 1 can be formed.

In the present specification, the weight average molecular weight is a value calculated by GPC (gel permeation chromatography, manufactured by TOSOH, HLC-8320GPC) and calculated by polystyrene conversion. The measurement conditions are as follows. Column: SHODEXGPC KF-802.5 (inner diameter 8.0 mm x length 300 mm) / GPC KF-G (inner diameter 4.6 mm x length 10 mm) Eluent: tetrahydrofuran (THF) / min, detector: differential refractometer (RI), column temperature: 40 占 폚, injection volume: 2 ml

The high molecular weight epoxy resin is preferably a rubber-modified epoxy resin. As a result, it is possible to favorably impart moisture resistance, chemical resistance, and oligomer release inhibition to the cured resin layer 2 while improving adhesion with the transparent resin film 1. The rubber component for modifying the epoxy resin is not particularly limited, and examples thereof include conjugated diene rubber such as butadiene rubber, acrylonitrile butadiene rubber, styrene butadiene rubber, butyl rubber, natural rubber, isoprene rubber and chloroprene rubber; Ethylene-propylene rubber, urethane rubber, silicone rubber, fluorine rubber, ethylene-vinyl acetate rubber and epichlorohydrin rubber. Of these, the conjugated diene rubber modification is preferable from the above viewpoints, and the butadiene rubber modification, the butyl rubber modification and the acrylonitrile butadiene rubber modification are more preferable. The rubber-modified epoxy resin may be used alone or in combination of two or more.

As a method for preparing the rubber-modified epoxy resin, conventionally known methods can be adopted. For example, a carboxyl group is introduced at the end of the polymer main chain of the rubber component, and the carboxyl group and the epoxy group of the epoxy resin are reacted with phosphorus catalyst or amine catalyst Or the like in the presence of a catalyst.

An epoxy resin having a weight average molecular weight of less than 3,000 (hereinafter, also referred to as " low molecular weight epoxy resin ") among the above-mentioned epoxy resins may be used together with the high molecular weight epoxy resin. As the low molecular weight epoxy resin, an alicyclic epoxy resin is preferable. As the alicyclic epoxy resin, known ones can be preferably employed, and examples thereof include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate,? -Caprolactone-modified 3 ', 4 Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 1,2-epoxy-4-vinylcyclohexane, 3,4-epoxycyclohexane-1-carboxylate, hydrogenated bisphenol A epoxy Resins and the like. The low molecular weight epoxy resin may be used alone or in combination of two or more kinds.

The resin composition preferably contains a curing accelerator. As a result, the curing reaction of the epoxy resin can be promptly and sufficiently promoted, and a cured film having high adhesion, moisture resistance and film strength can be formed. The curing accelerator is not particularly limited and includes, for example, an organic acid such as octanoic acid, stearic acid, acetylacetonate, naphthenic acid, salicylic acid and the like, and an organic metal salt such as zinc, copper, iron or antimony; Metal chelates and the like. Among them, it is preferable that the curing accelerator contains antimony. The antimony-containing curing accelerator can rapidly and sufficiently accelerate the curing reaction of the resin composition, and is capable of efficiently forming a stronger cured film having higher adhesion and moisture resistance. The curing accelerator may be used alone or in combination of two or more.

The content of the curing accelerator is not particularly limited, but may be 0.01 parts by weight or more, preferably 0.05 parts by weight or more, and more preferably 0.05 parts by weight or more, relative to the total amount (100 parts by weight) of the compound having an epoxy group in the resin composition 0.1 part by weight or more, for example, 5 parts by weight or less, preferably 4 parts by weight or less, more preferably 1 part by weight or less. If the content of the curing accelerator is less than the lower limit described above, the effect of accelerating the curing may be insufficient. On the other hand, if the content of the curing accelerator exceeds the upper limit, the cured product may be colored to deteriorate the color.

In addition to the epoxy resin, an acrylic resin, a urethane resin, an amide resin, a silicone resin, and the like may be appropriately added to the resin composition. In addition, various additives may be added to the resin composition. Examples of the additives include leveling agents, pigments, fillers, dispersants, plasticizers, ultraviolet absorbers, surfactants, antioxidants, thixotropic agents and the like.

(Physical Properties of Cured Resin Layer)

The adhesion of the cured resin layer 2 to the transparent resin film 1 is 50 N / 25 mm or more. The upper limit is not limited, but is, for example, 100 N / 25 mm. If the adhesive force of the cured resin layer 2 is less than 50 N / 25 mm, the adhesive force becomes insufficient and the adhesive strength between the transparent resin film 1 and the cured resin layer 2 And the cured resin layer 2 is deformed to cause a crack in the transparent electroconductive layer 3. As a result,

The adhesive force is measured by, for example, cutting the transparent conductive film 10 to a width of 25 mm and a length of 70 mm and successively cutting the transparent conductive layer 3 of the cut transparent conductive film 10 with an adhesive And then the film can be measured by pulling the transparent conductive film 10 along the longitudinal direction at an angle of 180 degrees at a rate of 0.3 mm / min using a peeling tester.

The cured resin layer 2 is formed between the transparent resin film 1 and the transparent conductive layer 3 and does not have a function as a conductor layer. That is, the cured resin layer 2 is formed as a dielectric layer so as to be able to be insulated between the transparent resin film 1 and the transparent conductive layer 3. Therefore, the cured resin layer 2 usually has a surface resistance of 1 x 10 ⁶ ? /? Or more, preferably 1 x 10 ⁷ ? / ?, more preferably 1 x 10 ⁸ ? / . The upper limit of the surface resistance of the cured resin layer 2 is not particularly limited. In general, the upper limit of the surface resistance of the cured resin layer (2), but the detection limit of 1 × 10 ¹³ Ω / □ or so, may be those exceeding 1 × 10 ¹³ Ω / □.

The thickness of the cured resin layer 2 is not particularly limited, but is preferably 150 nm or less, for example, 100 nm or less in view of adhesiveness, heat and humidity resistance, suppression of oligomer exudation from the transparent resin film (1) Or less, more preferably 50 nm or less, and, for example, 20 nm or more, and preferably 30 nm or more.

The cured resin layer 2 may be composed of two or more layers. In this case, the thickness of each cured resin layer is, for example, 20 nm or more, preferably 25 nm or more, and, for example, 60 nm or less, preferably 55 nm or less.

In this embodiment, by having the transparent conductive layer 3 and the cured resin layer 2, a good appearance can be obtained as a display element. From this point of view, the refractive index of the cured resin layer 2 preferably has a difference of 0.1 or more between the refractive index of the transparent conductive layer 3 and the refractive index of the cured resin layer 2. The difference between the refractive index of the transparent conductive layer 3 and the refractive index of the cured resin layer 2 is preferably 0.1 or more and 0.9 or less, more preferably 0.1 or more and 0.6 or less. The refractive index of the cured resin layer 2 is, for example, not less than 1.30, preferably not less than 1.38, more preferably not less than 1.40, and is, for example, not more than 2.50, preferably not more than 2.30. The refractive index is measured by Abbe's refractometer.

The method of forming the cured resin layer 2 is not particularly limited, but it is preferably formed by coating. First, the resin composition containing the above components is uniformly dissolved or dispersed in a solvent to prepare a coating solution. The solvent is not particularly limited and includes, for example, aromatic solvents such as toluene and xylene; Ketone solvents such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone; Examples of the solvent include diethyl ether, isopropyl ether, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, Ether-based solvents; Ester solvents such as ethyl acetate, butyl acetate, isopropyl acetate and ethylene glycol diacetate; Amide solvents such as dimethylformamide, diethylformamide and N-methylpyrrolidone; Cellosolve solvents such as methyl cellosolve, ethyl cellosolve and butyl cellosolve; Alcohol solvents such as methanol, ethanol and propanol; And halogen-based solvents such as dichloromethane and chloroform. The solvent may be used alone, or two or more solvents may be used in combination.

The solid content concentration of the coating solution is, for example, not less than 0.5% by weight, preferably not less than 1.0% by weight, more preferably not less than 1.5% by weight, and is, for example, not more than 2.5% by weight, preferably not more than 2.0% , More preferably not more than 1.9 wt%.

The cured resin layer 2 is formed by applying the coating solution on the transparent resin film 1 and curing it.

The coating method of the coating solution can be selected in a timely manner depending on the conditions of the coating solution and the coating process and can be appropriately selected depending on the conditions of the coating solution and the coating process. Examples of the coating method include a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, , A die coating method, an extrusion coating method, and the like.

Finally, the cured resin layer 2 can be formed by heating and curing the obtained coating film. As the heating method, for example, heating with a hot air dryer, an infrared dryer, a vacuum dryer, a microwave heating dryer or the like can be employed. The heating temperature is, for example, 100 占 폚 or higher, preferably 120 占 폚 or higher, for example, 200 占 폚 or lower, and preferably 180 占 폚 or lower. The heating time is, for example, 0.5 minutes or longer, preferably 1 minute or longer, and is, for example, 10 minutes or shorter, preferably 5 minutes or shorter.

(Transparent conductive layer)

The constituent material of the transparent conductive layer 3 is not particularly limited and may be selected from the group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium and tungsten And a metal oxide of at least one kind of metal. The metal oxide may further contain metal atoms shown in the above group, if necessary. Preferably, indium oxide (indium-tin composite oxide: ITO) containing tin oxide, tin oxide containing antimony, and the like can be given.

Although the thickness of the transparent conductive layer 3 is not particularly limited, a thickness of 10 nm or more is preferable in order to form a continuous coating film having a surface resistance of 1 x 10 < ³ > More preferably 15 nm or more, further preferably 20 nm or more, further preferably 35 nm or less, and further preferably 30 nm or less. When the thickness is less than 15 nm, the surface electrical resistance increases, and there is a fear that the continuous coating film becomes difficult to be formed. If it exceeds 35 nm, the transparency may be lowered.

As described above, the transparent conductive layer 3 preferably has a difference in refractive index from the cured resin layer 2 of 0.1 or more. The refractive index of the transparent conductive layer 3 is, for example, 1.95 or more and 2.05 or less.

The method for forming the transparent conductive layer 3 is not particularly limited, and conventionally known methods can be employed. Specifically, for example, a vacuum deposition method, a sputtering method, and an ion plating method can be mentioned. An appropriate method may be employed depending on the layer thickness required.

After the transparent conductive layer 3 is formed, it may be crystallized by heat treatment, for example, at a temperature in the range of 100 to 150 ° C, if necessary. The transparent conductive layer 3 is preferably a crystalline film from the viewpoint of good electrical properties.

For example, when the transparent conductive layer 3 is an ITO layer, the transparent conductive layer 3 is a crystalline film. The transparent conductive layer 3 is immersed in hydrochloric acid (concentration 5% by weight) at 20 캜 for 15 minutes, , And measuring the resistance between the terminals of about 15 mm. In this specification, after the transparent conductive film 10 is immersed in water (at 20 캜, concentration: 5% by weight), washed with water and dried, the inter-terminal resistance of 15 mm in the transparent conductive layer 3 is 10 kΩ, the transparent conductive layer 3 is assumed to be crystalline.

The rate of change of the surface resistance value of the transparent conductive layer 3 before and after the transparent conductive layer 3 is left for 240 hours in an atmosphere at a temperature of 85 캜 and a humidity of 85% is preferably 1.5 or less and more preferably 1.3 or less. As a result, even when the transparent conductive film 10 is placed in a severe environment, it can exhibit good electrical characteristics and can be used for various applications.

According to this transparent conductive film 10, the adhesion between the transparent resin film 1 and the cured resin layer 2 is excellent. Therefore, peeling of the cured resin layer 2 and the transparent resin film 1 can be prevented at the time of conveyance or pattern processing, and the cured resin layer 2 can be prevented from being warped or bulged. As a result, generation of cracks in the transparent conductive layer 3 on the upper surface of the cured resin layer 2 can be suppressed, and whitening can be prevented. Further, even in the case of bonding to the wiring circuit substrate, peeling at the bonding portion can be suppressed.

Further, the transparent conductive film 10 is excellent in heat and humidity resistance. That is, even under a high temperature and high humidity environment, the resistivity change can be suppressed. Also, the chemical resistance is excellent. That is, swelling or deformation of the cured resin layer 2 against isopropanol or an alkali solution can be suppressed. It is also possible to suppress oligomer exudation of the cured resin layer 2 at a high temperature.

(Modified example)

Although not shown, a hard coat layer, an easy adhesion layer, an anti-blocking layer, and the like may be formed on the surface of the transparent resin film 1 opposite to the surface on which the transparent conductive layer 3 is formed, if necessary.

In addition, as shown in Fig. 2, the transparent conductive layer 3 may be patterned (patterned). In the patterning, various embodiments can be formed as various patterns according to the application to which the transparent conductive film 10 is applied. The shape of the pattern may be, for example, a stripe shape or the like.

In the patterning, the transparent conductive layer 3 is covered with a mask for forming a pattern, for example, and the transparent conductive layer 3 is etched by an etching liquid. As the etching solution, an acid is preferably used. Examples of the acid include inorganic acids such as hydrogen chloride, hydrogen bromide, sulfuric acid, nitric acid, and phosphoric acid, organic acids such as acetic acid, and mixtures thereof, and aqueous solutions thereof.

As shown in Fig. 3, the transparent substrate 5 can be bonded to one side of the transparent conductive film 10 of the present embodiment via the transparent pressure-sensitive adhesive layer 4. Fig. That is, the transparent conductive film 10 shown in Fig. 3 has a transparent pressure-sensitive adhesive layer 4 on the transparent resin film 1 (the surface on which the transparent conductive layer 3 is not formed) of the transparent conductive film shown in Fig. 1 Is a transparent conductive film having a structure in which a transparent substrate 5 is bonded. The transparent substrate 5 may be a composite structure in which at least two transparent gas films are laminated by a transparent pressure-sensitive adhesive layer (4). The transparent conductive layer 3 may be patterned on the transparent conductive film 10 having such a structure.

The thickness of the transparent substrate 5 is, for example, 90 占 퐉 or more, preferably 100 占 퐉 or more, and, for example, 300 占 퐉 or less, preferably 250 占 퐉 or less. In the case of forming a plurality of base films forming the transparent base 5, the thickness of each base film is, for example, 10 占 퐉 or more, preferably 20 占 퐉 or more and, for example, 200 占 퐉 or less , Preferably not more than 150 mu m, and the total thickness of the transparent base body 5 including the pressure-sensitive adhesive layer transparent to these base films is controlled to fall within the above range. The gas film may be the same as the above-mentioned transparent resin film (1).

The pressure-sensitive adhesive layer (4) is not particularly limited as long as it has transparency. Specific examples thereof include polymers such as acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate / vinyl chloride copolymers, modified polyolefins, epoxy based, fluorine based, natural rubber, Rubber, or the like as a base polymer can be appropriately selected and used. In particular, an acrylic pressure-sensitive adhesive is preferably used because it has excellent optical transparency, exhibits adhesive properties such as appropriate wettability, cohesiveness and adhesiveness, and is also excellent in weather resistance and heat resistance.

The transparent base material 5 to be bonded via the pressure-sensitive adhesive layer 4 as described above gives a good mechanical strength to the transparent resin film 1 and is excellent in not only pen input durability and surface pressure durability but also, Contributing.

3, a hard coat layer (not shown) for protecting the outer surface is provided on the outer surface of the transparent substrate 5 (the surface opposite to the pressure-sensitive adhesive layer 4) (Resin layer) 6 may be formed. As the hard coat layer 6, for example, a cured coating of a curable resin such as a melanin resin, a urethane resin, an alkyd resin, an acrylic resin or a silicone resin can be given. The thickness of the hard coat layer 6 is preferably 0.1 mu m or more and 30 mu m or less. If the thickness is less than 0.1 탆, the hardness may be insufficient. If the thickness exceeds 30 탆, cracks may be generated in the hard coat layer 6 or curling may occur in the entire transparent substrate 5.

(Touch panel)

The transparent conductive film 10 of the present embodiment can be suitably applied to a touch panel such as an optical system, an ultrasonic system, a capacitive system, or a resistive film system. Particularly, it is preferable for a capacitive touch panel. Specifically, for example, the patterned transparent conductive film 10 shown in Fig. 2 is disposed on a protective substrate such as a protective glass to be used as a touch panel. The transparent conductive film of the present embodiment can be used in various applications such as, for example, an electrophoretic method, a twist ball method, a thermal rewritable method, an optical recording liquid crystal method, a polymer dispersed liquid crystal method, a guest / host liquid crystal method, , A chromatic system, an electric field deposition system, and the like.

≪ Second Embodiment >

In the first embodiment, one layer of the cured resin layer 2 is formed between the transparent resin film 1 and the transparent conductive layer 3. In the second embodiment, as shown in Fig. 4, In addition to the cured resin layer 2, an inorganic layer 9 is formed on the upper side thereof. That is, in the second embodiment, the cured resin layer 2 and the inorganic layer 9 are formed in this order from the transparent resin film 1 side. In Fig. 4, the transparent conductive layer 3 is not patterned, but may be patterned. The inorganic layer 9 may be patterned or not patterned.

As the material for the inorganic material layer (9) on the upper _{side, NaF (1.3), Na 3} AlF 6 (1.35), LiF (1.36), MgF 2 (1.38), CaF 2 (1.4), BaF 2 (1.3), SiO 2 ( 1.46), LaF ₃ (1.55), CeF ₃ (1.63), Al ₂ O ₃ (1.63) and the like [numerical values in parentheses of each material are refractive index of light]. Of these, SiO ₂ , MgF ₂ , and Al ₂ O ₃ are preferable, and SiO ₂ is particularly preferable. In addition to the above, composite oxides containing about 10 to 40 parts by weight of cerium oxide and about 0 to 20 parts by weight of tin oxide can be used for 100 parts by weight of indium oxide.

The inorganic layer 9 can be formed by a dry process such as a vacuum evaporation method, a sputtering method, an ion plating method, or a wet method (coating method). In the wet method, the SiO ₂ film can be preferably formed by coating silica sol or the like.

4 shows a case where the cured resin layer 2 is composed of two layers. For example, although not shown, the cured resin layer 2 may have three or more layers.

≪ Third Embodiment >

In the third embodiment, as shown in Fig. 5, the transparent resin film 1 has a transparent conductive layer 3 on both sides with a cured resin layer 2 interposed therebetween. In the transparent conductive film shown in Fig. 5, the transparent conductive layers 3 on both sides are not patterned, but may be patterned. Alternatively, only the transparent conductive layer 3 on one side may be patterned.

Example

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to the embodiments and the comparative examples. Specific values such as a blend ratio (content ratio), a physical property value and a parameter to be used in the following description are the same as the blend ratio (content ratio), the physical property value (The value defined as "less than" or "less than") or the lower limit value (the value defined as "greater than or equal to" or "greater than").

Example 1

(Formation of Cured Resin Layer)

, 100 parts by weight of AdekaPylthera CRX-49 having a rubber-modified epoxy resin (weight-average molecular weight of epoxy resin skeleton portion: 3500) as a main component, and 0.1 part by weight of Adekafiltera BUR-4B as an antimony curing accelerator , And 5000 parts by weight of methyl isobutyl ketone was added to this mixture to prepare a coating solution. The coating solution was applied to one side of a transparent resin film made of a polyethylene terephthalate film (hereinafter referred to as PET film) having a thickness of 50 占 퐉, and the coating film was dried at 195 占 폚 for 1 minute, Thereby forming a cured resin layer (refractive index of light: 1.51).

(Formation of transparent conductive layer)

Next, by a reactive sputtering method using a sintered material of 90% by weight of indium oxide and 10% by weight of tin oxide in an atmosphere of 0.4 Pa consisting of 98% of argon gas and 2% of oxygen gas on the cured resin layer, (Refractive index of light: 2.00) was formed on the transparent conductive film to obtain a transparent conductive film.

(Crystallization of ITO film)

The ITO layer was crystallized by heat treatment at 140 占 폚 for 90 minutes to prepare a transparent conductive film of the example (see Fig. 1).

Comparative Example 1

, 10 parts by weight of Adekafiltera BUR-12A containing a rubber-modified epoxy resin (weight-average molecular weight of epoxy resin skeleton part: 2000) as a main component and 0.001 part by weight of Adeka Piperera BUR-12B as an antimony curing accelerator , And 5000 parts by weight of methyl isobutyl ketone was added to this mixture to prepare a coating solution. In the same manner as in Example 1, a transparent conductive film of Comparative Example was prepared.

Comparative Example 2

, 10 parts by weight of Adekafiltera CRX-5 having a main component of acrylic-modified epoxy resin (weight-average molecular weight of epoxy resin skeleton part: 500) and 0.5 part by weight of zinc-based curing accelerator (Adekastab) Was prepared in the same manner as in Example 1 except that 5000 parts by weight of methyl isobutyl ketone was added to the coating solution to prepare a coating solution.

Comparative Example 3

10 parts by weight of AdekaPilater CRX-3 containing epoxy resin (weight-average molecular weight: 500) as a main component, which was not subjected to the denaturation treatment, and 0.5 part by weight of a zinc-based curing accelerator (Adekastab) Except that 5000 parts by weight of methyl isobutyl ketone was added to prepare a coating solution, to prepare a transparent conductive film.

The following evaluations were performed on the transparent conductive films of Examples and Comparative Examples. The results are shown in Table 1.

(1) adhesion between PET and cured resin layer

And a mixture of a subject and a curing agent in a weight ratio of 15: 2 was used to prepare a mixed resin by using an Epopix kit (a main curing agent) manufactured by Marumoto Struers. The ITO surface of the transparent conductive film of Examples and Comparative Examples, in which the mixed resin was dropped onto the SUS substrate, and then cut into 25 mm x 70 mm, was bonded to the mixed resin. Thereafter, the mixture was heated at 60 DEG C for 150 minutes in order to cure the mixed resin. Thus, as shown in Fig. 6, an adhesion measurement sample having the transparent conductive film 10 fixed on the SUS substrate 7 with an adhesive (mixed resin) 8 interposed therebetween was obtained.

The sample transparent conductive film 10 was peeled off at an angle of 180 DEG at a speed of 0.3 m / min using a peeling tester (Tabletop Three-row Autograph AG-50KNXD, manufactured by Shimadzu Corporation) ). The force generated at the time of peeling was measured as adhesion force.

Further, since the measurement upper limit adhesion value of the device is 50 N, when the transparent conductive film is broken in the middle and the measurement value exceeds the upper limit value, measurement is impossible, it is said to be " 50 N / 25 mm or more ".

After the above measurement, the residual shape of the film on the SUS substrate was confirmed. In the case where the shape of the cup shape was maintained at the size of 25 mm x 70 mm at the time of bonding, it was evaluated as " cup shape holding ". If only the shape of the size was not maintained and only the piece remained It was evaluated as " fracture ". In addition, in the " fracture ", it is found that the transparent conductive film is not subjected to interfacial peeling but cohesively broken, and the adhesion between the PET layer and the cured resin layer is good.

(2) Humidity Resistance

The surface resistance value (? /?) Of the ITO layer was measured by a division method according to JIS K7194 (1994), and this was regarded as an initial surface resistance value (R ₀ ). Then, the surface resistance value (R ₂₄₀ ) was measured when the sample was allowed to stand in a constant temperature and humidity chamber (LHL-113, manufactured by Especa) set to 85 ° C and 85% RH for 240 hours. From these, R ₂₄₀ / R ₀ was obtained as the resistance change ratio. A case where the rate of resistance change was 1.5 or less was evaluated as "", and a case where the rate of change exceeded 1.5 was evaluated as " x ".

(3) Solvent resistance

The transparent conductive films of Examples and Comparative Examples in which the ITO layer was patterned in a stripe pattern were used (see FIG. 2). The patterned transparent conductive film was immersed in isopropanol at 25 DEG C for 10 minutes, taken out, washed with pure water, and dried. The surface of the cured resin layer at that time was visually observed. Quot ;, "? &Quot;, "? &Quot;, "? &Quot;, and " X ".

(4) Alkali durability

The patterned transparent conductive film was immersed in an alkali solution (5 wt%) at 50 캜 for 5 minutes, taken out, cleaned with pure water, and dried. The surface of the cured resin layer at that time was visually observed. Quot ;, "? &Quot;, "? &Quot;, "? &Quot;, " Respectively.

(5) Existence of oligomer exudation

The patterned transparent conductive film was heat-treated at 160 DEG C for 2 hours. The exudation of the oligomer from the cured resin layer at that time was visually confirmed. The case where the exudation of oligomer was not observed was evaluated as " ", the case where the exudation of oligomer was observed slightly and the case where the exudation of oligomer was observed over a wide range was evaluated as "

From Table 1, it was confirmed that the transparent conductive film of the examples had excellent moisture and heat resistance, and also had a high adhesive force with the cured resin layer. It is also confirmed that the transparent conductive film of the examples is excellent in chemical resistance and can suppress the exudation of oligomer from the cured resin layer.

The above-mentioned invention is provided as an exemplary embodiment of the present invention, but this is merely an example, and should not be construed as limiting. Variations of the invention that are evident to one skilled in the art are included in the scope of the latter claims.

Industrial availability

INDUSTRIAL APPLICABILITY The transparent conductive film and the touch panel of the present invention can be applied to various industrial products, and are preferably used for, for example, an image display device.

1: transparent resin film
2: Cured resin layer
3: transparent conductive layer
4: Pressure-sensitive adhesive layer
5: Transparent gas
6: Hard coat layer
7: SUS substrate
8: Adhesive
9: inorganic layer
10: transparent conductive film

Claims (7)

A transparent resin film, a cured resin layer, and a transparent conductive layer in this order,
Wherein the cured resin layer is a cured film formed by curing a resin composition containing an epoxy resin having a weight average molecular weight of 3000 or more. The method according to claim 1,
Wherein the cured resin layer has a thickness of 150 nm or less. The method according to claim 1,
Wherein the epoxy resin is a rubber-modified epoxy resin. The method according to claim 1,
Wherein the resin composition contains a curing accelerator and the curing accelerator contains antimony. The method according to claim 1,
Wherein the adhesive strength of the cured resin layer to the transparent resin film is 50 N / 25 mm or more. The method according to claim 1,
Wherein the rate of change of the surface resistance value of the transparent conductive layer is about 1.5 or less before and after the transparent conductive layer is left in an atmosphere at a temperature of 85 캜 and a humidity of 85% for 240 hours. A touch panel comprising the transparent conductive film according to claim 1.

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