JP4754955B2 - Conductive film for touch panel and conductive film manufacturing method for touch panel - Google Patents

Description

  The present invention relates to a conductive film for a touch panel used as a transparent conductive film for a display of a touch panel and a method for producing the same. Specifically, the present invention relates to a conductive film for a touch panel that is stable even under severe conditions of high temperature and high humidity, and has little deterioration due to sliding, and a method for manufacturing the same.

2. Description of the Related Art A touch panel that is arranged on a display device such as a CRT or an LCD and can input data, instructions, and commands by pressing with a finger or a pen while watching the display is widely used.
A transparent conductive film for a touch panel (hereinafter referred to as TP) is made of a polyethylene terephthalate film (hereinafter sometimes referred to as PET film) or a transparent conductive material such as indium tin oxide (hereinafter sometimes referred to as ITO). It is manufactured by being attached by a technique such as sputtering. For example, in a resistive film type touch panel, in general, a transparent conductive glass plate in which ITO is attached by a method such as sputtering and a transparent conductive film in which ITO is attached to a plastic film such as the PET film by a method such as sputtering. Are used as electrodes facing each other through a spacer. There are amorphous and crystalline ITOs, and it is generally known that crystalline ITO is superior to amorphous ITO in terms of strength and environmental resistance (for example, patents). Reference 1). It is well known that ITO is amorphous after sputtering, but is then converted to crystalline ITO by heat treatment at a temperature of 100 ° C. or higher.

  However, although crystalline ITO itself is superior in strength compared to amorphous one, it can be used for TP to slide hundreds of thousands of times with a pen or finger. When it is bent or rolled in the process of manufacturing TP, or when it is placed in a harsh environment such as 85 ° C, 85% humidity or 90 ° C, the ITO layer may crack or peel off from the PET film. There was a problem that the value increased greatly and it did not function as an electrode for TP. Since amorphous ITO is inferior in chemical stability, there is a problem that the resistance value fluctuates in a severe environment of 85 ° C. and humidity of 85%. In recent years, TP is required for car navigation mounted on a car, and a transparent conductive film having a small change in resistance value under a severe environment is required.

  JP-A-8-064034

  An object of the present invention is to solve all the conventional problems and achieve the following objects. That is, an object of the present invention is to provide a conductive film for a touch panel having a small change in resistance value even in a harsh environment and having good sliding characteristics, and a method for producing the same.

  The present inventor has intensively studied to solve the above-mentioned problem of crystalline ITO, and it is common to apply a temperature of about 150 ° C. in the process of crystallizing the amorphous ITO after sputtering. However, the PET film of the substrate shrinks by 1% or more after this treatment, and the inorganic transparent conductive material such as ITO hardly expands or shrinks even after heat treatment at 150 ° C. Because of this, at the interface between the ITO layer and the PET film, it is estimated that the ITO layer is peeled off, micro cracks are occurring, or such a situation is likely to occur, In order to take advantage of the strength and environmental resistance of crystallization 1TO itself, the PET film used as the substrate is pre-treated to keep the thermal shrinkage at 150 ° C low. Depositing a ITO by a technique such as sputtering using, if the ITO over the temperature of the subsequent order of 100 ° C. to 250 DEG ° C. using those crystallized, it found that the above problems can be solved at once, have reached the present invention.

That is, the means for solving the above problems are as follows.
<1> Obtained by attaching a conductive film to a substrate having a shrinkage in the longitudinal direction (MD) and the transverse direction (TD) of 0.5% or less when heated at 150 ° C. for 1 hour, A conductive film for a touch panel, wherein the substrate includes at least a biaxially stretched polyethylene terephthalate film, the conductive film is a metal oxide conductive film, and includes 50% by weight or more of a crystallized portion.
<2> The conductive film for a touch panel according to <1>, wherein the substrate further includes a cured layer in which a crosslinkable substance is cured and formed.
<3> The conductive film for a touch panel according to <2>, wherein the substrate has a cured layer in which a thermally crosslinkable substance is cured and formed as a cured layer.
<4> The conductive film for a touch panel according to <3>, wherein the base further has a cured layer in which a crosslinkable substance by light or electron beam is cured and formed.
<5> The conductive film for a touch panel according to <4>, wherein the substrate has a cured layer formed by curing a crosslinkable substance by light or electron beam on both sides of the PET film layer.
<6> The conductive film for a touch panel according to any one of <1> to <5>, wherein the conductive film is ITO (indium tin oxide).
<7> A conductive film is attached to a substrate that has been pretreated so that the thermal shrinkage in the MD and TD directions when heated at 150 ° C. for 1 hour is 0.5% or less. The transparent conductive film according to any one of <1> to <6>, wherein the heat treatment is performed at 250 ° C.
<8> The substrate includes at least one cured layer, and the cured layer heat-treats the PET film at a temperature between 100 ° C. and 180 ° C., or the PET film between 100 ° C. and 180 ° C. The conductive film for a touch panel according to <7>, which is obtained by curing a crosslinkable substance on at least one surface of the PET film after heat treatment at a temperature.
<9> At least one cured layer simultaneously heat-treats the PET film at a temperature between 100 ° C. and 180 ° C. or after heat-treating the PET film at a temperature between 100 ° C. and 180 ° C. The conductive film for a touch panel according to <8>, which is obtained by curing a crosslinkable substance on at least one surface of the PET film before the PET film is cooled to room temperature.
<10> After at least one cured layer heat-treats the PET film at a temperature between 120 ° C. and 180 ° C. or after heat-treating the PET film at a temperature between 120 ° C. and 180 ° C. The conductive film for a touch panel according to <8>, which is obtained by curing a crosslinkable substance on at least one surface of the PET film.
<11> The conductive film for a touch panel according to <3>, wherein a thickness of a cured layer obtained by curing the crosslinkable substance with heat is 0.3 μm to 10 μm.
<12> The conductive film for a touch panel according to <4>, wherein the pencil hardness of the surface of the conductive film opposite to the conductive film is 3H or more.
<13> The conductive film for a touch panel according to any one of <1> to <12>, wherein at least one of the cured layers is a layer having an antiglare function having a haze value of 1 to 20%.
<14> The conductive film for a touch panel according to any one of <1> to <13>, wherein the base has an antiglare layer, and the conductive film is attached to the antiglare layer.
<15> The touch panel according to any one of <1> to <14>, further including a second substrate on an opposite surface to the conductive film of the first substrate, which is the substrate, via an adhesive layer. Conductive film.
<16> A substrate having at least a biaxially stretched polyethylene terephthalate film and a cured layer in which a crosslinkable substance is cured and formed, and when heated at 150 ° C. for 1 hour, the longitudinal direction (MD) and the transverse direction ( TD) a substrate preparation step for preparing a substrate having a shrinkage ratio of 0.5% or less, a conductive film attachment step for attaching a conductive film to the substrate prepared by the substrate preparation step, and a conductive film attached. And a crystallization step of heat-treating the substrate at 100 ° C. to 250 ° C. In the substrate preparation step, at least one cured layer is heat-treated at a temperature between 100 ° C. and 180 ° C. At the same time, or after heat-treating the PET film at a temperature between 100 ° C. and 180 ° C., the crosslinkable substance is cured on at least one surface of the PET film. A method for producing a conductive film for a touch panel, wherein the film is formed by curing.
<17> In the substrate preparation step, at least one cured layer is subjected to heat treatment of the PET film at a temperature between 100 ° C. and 180 ° C., or at the same time, the PET film is heated at a temperature between 100 ° C. and 180 ° C. After the heat treatment and before the PET film is cooled to room temperature, the crosslinkable substance is cured on at least one surface of the PET film to form a cured film. Manufacturing method of conductive film for touch panel.
<18> In the state in which the base preparation step cures the thermally crosslinkable substance on at least one surface of the PET film, a force of 5 kg / cm ^{2 to} 50 kg / cm ² is applied in the longitudinal direction (MD). The manufacturing method of the conductive film for touchscreens as described in said <16> including the process hardened at the temperature of the range of 100 to 180 degreeC.

Hereinafter, embodiments of the present invention will be described.
The conductive film for a touch panel of the present invention attaches a conductive film to a substrate whose shrinkage in the longitudinal direction (MD) and the transverse direction (TD) is 0.5% or less when heated at 150 ° C. for 1 hour. A conductive film for a touch panel, wherein the substrate includes at least a biaxially stretched PET film, the conductive film is a metal oxide conductive film, and includes 50% by weight or more of a crystallized portion. .

The conductive film of the present invention has transparency because it uses a PET film as a main component of the substrate, and is used as a transparent conductive film of a touch panel. Although there is no restriction | limiting in particular in the transparency of the electroconductive film of this invention, When using for TP, transparency is important and it is preferable that the transmittance | permeability of visible light is 70% or more, and it is 85% or more. It is more preferable. Transparency changes in addition to the transmittance of the PET film as a base material, depending on the type of various crosslinkable substances, thickness and curing conditions, the degree of oxidation and thickness of ITO, the difference in crystalline and amorphous types, etc. However, it is preferable to adjust all these factors to obtain high transparency.
The PET film may be modified so as not to impair characteristics such as transparency and heat resistance. The PET film may contain additives added for various purposes such as antioxidants, ultraviolet absorbers, colorants, and lubricants. In addition, in order to improve the adhesion of a conductive material such as a curable substance or ITO attached to the surface, corona treatment or plasma treatment is performed, or an easy-adhesion layer such as acrylic resin for improving adhesiveness is provided in advance. The coated one is often used, but is preferably used.

  The thickness of the PET film is not particularly limited, but when used for TP, a film having a thickness of 50 to 400 μm is preferable, particularly a film having a thickness of 80 to 250 μm, in terms of workability and waist strength. Is preferred. When applying this technique when bonding two PET and improving slidability, it is preferable that the sum total of two PET film thickness is the said thickness.

The substrate may be composed only of a biaxially stretched PET film, but preferably has a cured layer in which a crosslinkable substance is cured and formed in addition to the PET film layer. The hardened layer may be a single layer or a plurality of hardened layers. Moreover, the hardened layer may be laminated | stacked on the electrically conductive film side of PET film, may be laminated | stacked on the opposite side to a electrically conductive film, and may be laminated | stacked on both sides.
The cured layer on which the crosslinkable substance is cured is formed on the surface of the PET film, the PET film is stabilized against heat, and ITO is attached to the film at a temperature of about 150 ° C. Since the dimensional change is small even when the paste is cured, the sliding resistance of the conductive film is remarkably improved.

  The crosslinkable substance is not particularly limited, and a known substance can be used. However, a heat crosslinkable substance, a light crosslinkable substance such as an ultraviolet ray crosslinkable substance, a crosslinkable substance by an electron beam, or the like may be used. it can. For example, thermal crosslinkable substances, light crosslinkable substances and electron beam crosslinkable substances include melanin resins, urethane resins, urethane acrylic resins, alkyd resins, acrylic resins, silicon resins, epoxy resins, etc. Mold resins and the like, and two or more of these may be mixed, or a hybrid of two or more of the structures may be used. Initiators and molecular weight regulators are prepared for curing.

  An example of the crosslinkable substance used in the present invention will be given. For example, a crosslinkable monomer having two or more acrylic or methacrylic double bonds in the molecule, a crosslinkable monomer having two or more allyl groups in the molecule, or two or more in the molecule And a crosslinkable monomer having an aromatic vinyl double bond, or an oligomer or polymer thereof.

  Examples of commercially available crosslinkable monomers having two or more acrylic or methacrylic double bonds in the molecule include Biscoat 700 (Osaka Organic Chemical Co., Ltd.), KAYARAD R-551 (Japan) Kayaku Co., Ltd.), Aronix M-315 (Toa Gosei Co., Ltd.), Aronix M-210 (Same), BP-4PA (Kyoeisha Yushi Co., Ltd.), BP-4EA (same), Ubimer UVSA -1002 (manufactured by Mitsubishi Yuka Co., Ltd.), Ubimer UVSA-2006 (same), and the like.

  Examples of the crosslinkable monomer having two or more allyl groups in the molecule include diallyl phthalate, diallyl terephthalate, diallyl isophthalate, triallyl isocyanurate, triallyl cyanurate, and diethylene glycol bisallyl carbonate. Can do.

  Furthermore, as a crosslinkable monomer having two or more aromatic vinyl double bonds in the molecule, for example, divinylbenzene, diisopropenylbenzene, divinyltoluene, trivinylbenzene, diisopropenyltoluene, divinyl Naphthalene, diisopropenylnaphthalene, 4,4′-divinylbiphenyl, 4,4′-diisopropenylbiphenyl and the like can be mentioned.

Furthermore, among the crosslinkable substances, examples of the oligomer include oligomers of the crosslinkable monomer, and the degree of polymerization is usually about 2 to 1,000, preferably about 2 to 100.
Furthermore, among the crosslinkable substances, examples of the polymer include polyether polyurethanes, polyester polyurethanes, polycaprolactone polyurethanes and the like having an ethylenically unsaturated group derived from an acrylic or methacrylic double bond at the molecular end.
Furthermore, what added the silane coupling agent to the epoxy acrylate prepolymer can also be used, and the addition amount of the silane coupling agent is generally 0.5 to 1% by weight, epoxy group, amino group Those having a mercapton group are preferable.
As the urethane-based resin, those obtained by curing a polyol compound having two or more hydroxyl groups in one molecule with a polyfunctional isocyanate compound are suitably used. Examples of the polyol compound include polyether polyols such as ethylene glycol and diethylene glycol, epoxy resin-modified polyols, polyester polyols, saponified ethylene vinyl alcohol copolymers, and phenoxy resins.

In addition, when a crosslinkable substance is used as a heat crosslinkable substance, the other monomer, oligomer, or polymer which has thermopolymerization may be added.
In this case, if the proportion of the heat-crosslinkable substance is reduced, a strong coating film cannot be obtained. Therefore, the proportion is at least 20 wt% or more, preferably 30 wt% or more, more preferably 50 wt% or more. It is necessary.
Moreover, when using as a heat-crosslinkable substance, you may add a radical polymerization initiator.
Examples of the radical polymerization initiator include peroxides and azo compounds, and more specifically, benzoyl peroxide, L-butylperoxybenzoate, azobisisobutyronitrile, and the like. . These radical polymerization initiators can be used alone or in combination of two or more.
The addition amount of the radical polymerization initiator is 0 to 2 parts by weight, preferably 0.001 to 1 part by weight based on 100 parts by weight of the thermally crosslinkable substance.

On the other hand, when the crosslinkable substance is used as a photocrosslinkable substance such as ultraviolet rays, other monomers, oligomers or polymers having photopolymerization may be added. In this case, if the proportion of the photocrosslinkable substance is reduced, a strong coating film cannot be obtained. Therefore, the proportion is at least 20% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more. It is necessary.
Moreover, when using as a photocrosslinkable substance, you may add a photoinitiator.
Examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, acetophenone, benzophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3- Methyl acetophenone, 4-chlorobenzophenone, 4-4′-dimethoxybenzophenone, 4-4′-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy 2-methylpropan-1-one, 2-hydroxy-2-methyl-phenylpropan-1-one, thioxanthone compounds, 2-methyl-1- [4- (methyl Thio) phenyl] -2-morpholinophenyl no-1-one, 2,4,6-trimethylbenzoyl diphenyl - phosphine oxide. These photopolymerization initiators can be used alone or in combination of two or more.
The addition amount of a photoinitiator is 0-5 weight part with respect to 100 weight part of photocrosslinkable substances, Preferably it is 0.1-3 weight part, More preferably, it is 0.2-3 weight part. The photopolymerization initiator can be used in combination with a photosensitizer (polymerization accelerator) such as an amine compound as necessary.

  In addition to the solvent added as necessary, the crosslinkable substance used in the present invention may contain a reactive diluent, an antioxidant, a polymerization inhibitor, a leveling agent, a surfactant and the like.

These curable resins can also be used in combination, and several layers such as laminating a cured layer by light such as ultraviolet rays on a thermally cured layer can be applied. From the viewpoint of transparency and the like, an acrylic resin, a urethane acrylic resin, or a silicon resin is preferably used. A composition obtained by adding various additives such as an antistatic agent and a polymerization initiator is usually diluted with a solution and adjusted so that the solid content of the crosslinkable resin is 20 to 80% by weight.
The thickness of the layer after curing is not particularly limited, but may be 0.3 μm or more from the viewpoint of imparting stability to suppress changes due to heat of the PET film, preventing damage to the substrate, and sliding resistance. Preferably, it is 0.5 μm, more preferably 1 μm or more. Further, from the viewpoint of productivity, one layer is preferably 10 μm or less, more preferably 5 μm or less, particularly in the case of a thermosetting cured layer, from the viewpoint of productivity required for curing, 5 μm or less. It is particularly preferred that

FIG. 1 illustrates a preferred configuration of the conductive film for a touch panel of the present invention. FIG. 1A shows a conductive film having a base 1 and a conductive film 2, wherein the base 1 has a cured layer 4 in which a crosslinkable substance is cured and formed on one side of a PET film 3. In this example, the conductive film 2 is provided. FIG. 1B shows an example in which the substrate 1 has a cured layer 4 in which a crosslinkable substance is cured and formed on one side of the PET film 3, and the conductive film 2 is formed on the opposite surface of the PET film 3. . In the present invention, the cured layer is not essential, but in the case of such an embodiment having the cured layer, it may be provided on the conductive film side of the PET film or on the opposite side of the conductive film. , May be provided on both sides. In any case, as the cured layer, a cured layer in which a thermally crosslinkable substance is cured and formed, a cured layer in which a crosslinkable substance by light is cured and a crosslinkable substance by electron beam is cured and formed. A layer appropriately selected from the cured layers and the like can be used. As the pre-cured layer, the PET film 3 has a cured layer in which a crosslinkable substance is cured and formed by heat. As described in detail later, it can be manufactured by a simplified process and has excellent sliding resistance. It is preferable at the point which can obtain property.
1C, D, E, and F are examples in which there are a plurality of hardened layers 4. For example, in FIGS. 1C and 1D, the hardened layer 4a includes a hardened layer on which a thermally crosslinkable substance is hardened. Examples of the cured layer 4b include a configuration having a cured layer in which a light or electron beam crosslinkable substance is cured and formed.

  As a preferred embodiment of the conductive film of the present invention, the substrate includes a cured layer in which a thermally crosslinkable substance is cured and formed, and at least one crosslinkable substance by light or electron beam is cured and formed. And a conductive film having a cured layer formed. As the cured layer, it is preferable to use a cured layer in which a crosslinkable material is cured and formed by heat in that the process can be simplified and excellent sliding resistance can be obtained. In such applications where scratch prevention is required, it is insufficient in hardness to provide the scratch-preventing effect of the conductive film for the TP touch surface with only a thermosetting resin. In general, when used as a TP electrode, it is touched with a finger or a pen or rubbed with a pen, so that the opposite surface (touch surface) of the conductive film such as an ITO layer is not easily damaged. In addition, a high hardness of 3H or more is required. Thermally crosslinkable substances usually have a limit of hardness H or 2H at a thickness of 5 μm or less, and a hardness higher than this is required unless long-term curing is economically disadvantageous or the film thickness is increased. It is difficult to put out. On the other hand, the hardened layer cross-linked by light or electron beam can obtain 3H hardness in a short time.

  Therefore, for example, in the configuration of FIGS. 1C and 1D, as a cured layer mainly for low shrinkage and thermal stabilization, the cured layer 4a is a thermosetting resin layer having a thickness of 5 μm or less, and a scratch preventing layer for obtaining surface hardness is obtained. As a hardened layer that also serves as a role, a hardened layer (in particular, an ultraviolet curable resin layer or an electron beam curable resin layer) in which a hardened layer 4b is cured with a light-curing or electron beam crosslinkable substance having a high curing speed and sufficient hardness. It is preferable that both productivity and high hardness can be achieved, and that the resistance value does not fluctuate even under severe conditions and that the sliding resistance is excellent. From the viewpoint of preventing scratches, it is preferable that the cured layer on which the crosslinkable substance by light or electron beam is cured and formed is provided at least on the side opposite to the conductive film 2 of the PET film 3 to be a touch surface.

  In the present invention, it is preferable to first form a cured layer 4a that is crosslinked by heat on one side of the PET film 3, to stabilize against heat, and then to form a layer that is crosslinked and cured by light or an electron beam. In FIG. 1C, the thermosetting layer 4 a and the light or electron beam curing layer 4 b are overlapped on the touch surface, and the conductive film is directly formed on the PET layer 3. In FIG. 1D, a thermosetting layer 4a and a light or electron beam curing layer 4b are formed on both sides of the PET layer 3, and the conductive film 2 is formed on the thermosetting layer 4a. FIG. 1D shows that a hardened layer is formed at least on both sides, and that it is difficult to warp when used as an electrode. This is a preferable configuration in that it is difficult for the above to occur. Further, the hardened layer of 4a or 4b can be a hardened layer having an antiglare effect in order to enhance the visibility of the TP used outside.

  The hardened layer that is crosslinked by heat is not used for the conventional resin layer provided on the touch surface opposite to the ITO surface for the purpose of preventing scratches because the hardness is slightly insufficient as described above. Currently used TP electrodes often have a cured layer that is cross-linked by light on the TP touch surface.

It is also preferable to further provide a hardened layer from the viewpoint of further improving the sliding resistance. For example, in FIGS. 1E and 1F, the cured layer 4a has a cured layer on which a thermally crosslinkable substance is cured, and the cured layers 4b and 4c are cured with a light or electron beam crosslinkable substance. And the like having a cured layer formed. The structure in which the 4b and 4c layers are present on both sides of the PET film provides a hardness of 3H or higher on the touch surface, can provide anti-Newton ring performance, and has a cured layer on both sides, so that a mechanical strength balance can be obtained. It is the most preferable configuration because it is difficult to warp, and by making the both surfaces 3H or more, it is difficult to generate scratches or the like in the process or handling. In FIG. 1E and FIG. 1F, first, a cured layer 4a that is crosslinked by heat is applied to the PET film layer 3, and dried and cured at 100 ° C. to 180 ° C. After this, a hardened layer that can be cross-linked by light or electron beam can be formed either on the 4a layer or on the non-coated surface of the 4a layer, and then the hardened layer can be similarly formed on the opposite surface. . In this case, it is desirable to select the type, thickness, and degree of crosslinking of the resin so that the touch surface of TP is 3H or more. The hardness of the surface to which the conductive film such as ITO is applied is not necessarily 3H, but it is possible to suppress the generation of scratches in the process and handling, and considering the balance of mechanical strength on both sides, the type of resin , Thickness, degree of crosslinking, etc. can be selected.
In addition, when providing a hardened layer on both sides, selecting ones with the same thermal expansion coefficient on both sides can balance the strength and cause wrinkles or cracks when exposed to high heat. It is preferable in terms of difficulty. 1E and 1F are the most preferable configurations from the viewpoint of practical use for TP.
When laminating a cured layer on which a thermally crosslinkable substance is cured and a cured layer on which a crosslinkable substance by light or electron beam is cured, the overall thickness of the overcoated layer depends on the required hardness. However, if it is about 3H which is generally required, 2 μm to 10 μm is preferable. Judging comprehensively from productivity, low shrinkage, its stability, hardness, etc., the thermosetting resin layer is 0.5 μm to 5 μm, and the ultraviolet curable layer applied on this is 1 to 6 μm. Is preferred.

In addition, the cured layer (at least one layer when there are a plurality of cured layers) for processing necessary for the conductive film for TP, such as prevention of image glare, antireflection, and prevention of Newton rings. Various additives can be added to or treated. For these purposes, the substrate may be further coated with heat or ultraviolet curable resin.
The anti-Newton ring effect can be imparted to the hardened layer below the surface on which the conductive film is formed, for example, the 4c layer in FIG. 1E and the 4b layer in FIG. 1F. Specifically, organic particles such as acrylic particles and inorganic particles such as silica particles are included in the resin component that is cross-linked by light or electron beam so that the haze value is 0.5 to 3%. Can be cured. When blended so that the haze value is small, the anti-Newton ring effect is small, and when it is large, glare may occur in the image. The haze value of this layer is between 0.5% and 3%, It is preferable to adjust. These particles are preferably mixed with particles having different diameters than those having a uniform particle diameter from the viewpoint of achieving a balance between anti-Newton ring property and prevention of image glare. Specifically, a mixture of particles having different diameters in the range of 1 to 6 μm is preferable, and a mixture of particles having different diameters in the range of 2 to 5 μm is more preferable.

  Anti-glare is preferred for displays used externally. Also in the case of providing the antiglare effect, for example, the layers 4a, 4b, and 4c in FIGS. E and F can be selected by controlling the haze value and selecting the total haze value. Generally, the haze value is selected between 2% and 20%. The haze value can be obtained by curing a resin component that is cross-linked with acrylic particles or silica particles mixed therein. In order to obtain a target haze value, it is preferable to adjust 4b and 4c obtained by curing a resin that crosslinks with light or an electron beam as the same haze value from the viewpoint of reducing the number of types of resin for obtaining a cured layer. Further, an embodiment in which at least one of the cured layers is a layer having an antiglare function having a haze value of 1 to 20% is preferable.

Moreover, it is preferable to give an antiglare and Newton ring prevention effect by including a silica particle etc. also in the hardening layer on the opposite side to the electrically conductive film of PET film.
In the case of a clear coat, it is preferable that none of the hardened layers contain particles such as silica or acrylic, and the overall haze value is preferably suppressed to 2% or less. Also in this case, generation of Newton rings may be avoided, silica or acrylic particles can be contained in the cured layer below the ITO layer, and it is preferable to adjust the haze value to 2% or less.
Silica particles are amorphous and porous, and a typical example is silica gel. A typical example of organic particles is acrylic particles. The average particle diameter is usually 30 μm or less, preferably about 2 to 15 μm, and the blending ratio is such that the particles are 0.1 to 10 parts by weight with respect to 100 parts by weight of the curable resin. Is preferred. Further, when the layer in contact with the conductive film of the substrate is an antiglare layer or an anti-Newton ring layer containing particles, the sliding resistance can be further improved. In other words, when a hardened layer containing particles such as silica is attached to give an effect of preventing Newton's ring, a conductive substance is formed on top of this, and the hardened layer containing particles becomes conductive. Since it is possible to improve the sliding resistance when it is at the lower part of the film, it is a preferable configuration.

The conductive film of the present invention is required to have a shrinkage in the longitudinal direction (MD) and the transverse direction (TD) of 0.5% or less when heated at 150 ° C. for 1 hour. Here, “the shrinkage in the longitudinal direction (MD) and the transverse direction (TD) when heated at 150 ° C. for 1 hour” is the room temperature after measuring the substrate at room temperature and then heating to 150 ° C. for 1 hour. This is the shrinkage rate measured by measuring again and measuring.
In order to satisfy the dimensional stability by heat and the sliding test of 250g 100,000 times at TP, it can be obtained by setting the thermal shrinkage rate at 150 ° C. of the conductive film of the present invention to 0.5% or less for both MD and TD. In order to satisfy the sliding test of 500 g and 300,000 times, the shrinkage ratio of MD and TD is preferably 0.4% or less, and more preferably 0.3% or less.

  There is no particular limitation on the method for reducing shrinkage, but it is necessary to reduce the shrinkage rate of the substrate before attaching the conductive film. In addition, at least one cured layer is crosslinked at the same time when the PET film is heat-treated at a temperature between 100 ° C. and 180 ° C. or after the PET film is heat-treated at a temperature between 100 ° C. and 180 ° C. In order to suppress and stabilize the shrinkage rate of the PET film, it is preferable that the material is obtained by curing at least one surface of the PET film. The heat treatment is more preferably performed at 120 ° C. or more, and particularly preferably at a temperature between 120 ° C. and 160 ° C. It is well known to anneal at a temperature around 150 ° C. to crystallize the ITO after depositing the ITO layer. In this case, as the transparent conductive film including the cured layer, the thermal shrinkage rate in the MD and TD directions can be 0.5% or less. However, the conductive film such as ITO and the organic matter such as PET film can be used. Due to the difference in thermal characteristics, this annealing treatment may leave stress between the ITO layer and the organic interface, and the ITO layer may be peeled off by sliding with a pen or the like, or the layer may be cracked.

  The PET film used as a material for the layer formed by the PET film of the substrate can be produced by a known method such as a melt extrusion method. From the viewpoint of surface smoothness, transparency, mechanical strength, heat resistance, etc., the degree of modification and the production method can be selected. From this point of view, a PET film produced by biaxial stretching is particularly preferable. A biaxially stretched film is stretched vertically and horizontally, and generally contracts greatly when heated. When the method of the present invention is used, it is preferable in that a biaxially stretched film can be kept low and stabilized. The surface of the PET film manufactured in this way is often coated to prevent surface glare and anti-glare and prevent reflection when used as a touch panel, so easy adhesion treatment is applied to one or both sides. You may use what was done. As the easy adhesion treatment, known methods such as corona discharge, ultraviolet irradiation, plasma treatment, sputter etching treatment, and primer treatment can be used. The coating agent for the easy-adhesion layer in the primer treatment is not particularly limited as long as it has the effect. For example, it is known to apply a polyester polymer or an acrylic polymer. It is also possible to include fine particles such as silica as a lubricant in this layer.

The shrinkage rate of the biaxially stretched PET film at 150 ° C. for 1 hour is usually 1.0 to 1.8% in MD (flow direction) and 0.1 to 1.0% in TD (lateral direction). . In order to reduce the shrinkage without providing a cured layer, the produced biaxially stretched PET film was continuously applied with a tension of about ² kg / cm ² to 50 kg / cm ^2, while A method of performing a heat treatment at ℃ to 180 ° C., a method of once winding a PET film in a roll shape, placing the roll in an electric furnace or the like, and performing a treatment at a temperature around 150 ° C., and both. A method or the like can be used.
The conductive film of the present invention may be prepared by preparing a PET film that has been subjected to a low shrinkage treatment in advance by the above-described method and laminating a cured layer on the PET film. In order to obtain a PET film having a shrinkage ratio in the range, a long-time treatment is required, resulting in a cost problem. Using a biaxially stretched film that has a low shrinkage rate of 0.5% or more at 150 ° C. for 1 hour as a material, a low shrinkage step and a step of laminating a thermosetting layer are performed simultaneously or continuously online. It is preferable from the viewpoint of improving the sliding resistance in the case of cost and a conductive film.

In a preferred embodiment of the present invention, the crosslinkable hardened layer material is cured film formation, from the roll of PET film, it is continuously fed while applying a stress of 2 kg / cm ² to 50 kg / cm ² PET A crosslinkable substance is applied to the film by a method such as a die coater, reverse coater, gravure coater, micro gravure coater, spray coater, slot orifice coater, roll coater, or screen printing. In the case of a substance, it can be prepared by a method such as passing through a furnace set at 100 ° C. to 180 ° C., curing and winding. At this time, curing of the crosslinkable substance and heat treatment of the PET film are simultaneously performed at a temperature of 100 ° C. to 180 ° C. Usually, it is preferable from the viewpoint of productivity that the furnace is cured for 1 to 60 minutes. The furnace may be a single chamber, but by dividing the chamber into several chambers and adjusting the temperature, generation of bubbles can be suppressed, the curing rate can be increased, and the smoothness of the cured film can be increased. This method is preferable in that it is not necessary to heat-treat the PET film in advance to reduce the shrinkage, and the process can be simplified. In addition, the substrate on which the heat treatment of the PET film and the cured layer are simultaneously cured has good sliding resistance.

  When the crosslinkable substance to be applied is to first cure a crosslinkable substance by light (for example, UV crosslinkable substance) or an electron beam crosslinkable substance instead of a thermally crosslinkable substance, thereby enhancing the thermal stability of the PET film. Apply the crosslinkable substance before passing through the furnace as in the case of the heat crosslinkable substance, pass through the furnace set at 100 ° C. to 180 ° C., and then cure by applying ultraviolet rays or the like, After passing through a furnace set at 100 ° C. to 180 ° C., it is cooled and coated with a crosslinkable substance, dried through a furnace set at about 20 ° C. to 130 ° C., and then cured by applying ultraviolet light or the like. . For the purpose other than stabilization of the PET film, for example, to increase the hardness to 3H, a known method can be used for coating and curing a substance that crosslinks with light or an electron beam. For example, an ultraviolet curable resin can be applied to a PET film with a gravure coater, dried and then irradiated with ultraviolet rays to be cured.

Examples of the conditions for curing the photocrosslinkable substance include irradiation with ultraviolet rays having a wavelength in the range of 200 to 500 nm for 0.1 seconds or longer, preferably 0.5 to 60 seconds.
Here, the integrated amount of irradiation is usually from 30 to 5.000 mj / cm ² , and as a light source, a low pressure mercury lamp, a high pressure mercury lamp, a carbon arc, a metal halide lamp, a mercury discharge tube, a tungsten lamp, A halogen lamp, a sodium discharge tube, a neon discharge tube, or the like can be used.

  The shrinkage rate can be controlled by the tension of the PET film when the curable resin is applied, the furnace temperature, the curing rate, and the like.

A conductive film is formed by attaching a conductive substance to the substrate having a low shrinkage rate by sputtering or the like to form a conductive film, thereby forming a conductive film based on a low-shrinkage PET film. Can do. In the case of a configuration having a cured layer on one side of the PET film, the conductive substance may be attached to either the surface on the side where the cured layer is provided or the surface on the side where the cured layer is not provided. Good.
The conductive film of the present invention is a metal oxide conductive film and contains 50% by weight or more of crystallized portions. The metal oxide conductive film is a conductive film substantially made of a metal oxide, typically ITO, but known metal oxides such as tin oxide and zinc oxide are used, and mixtures and alloys thereof. including. In addition to ITO, indium oxide is mainly used and gallium oxide, titanium oxide, germanium oxide or the like is mixed. By adding such a thing, crystallization may become easy. The conductive film of the present invention contains 50% by weight or more of a crystallized portion and is substantially a crystalline metal oxide. The crystallized portion can be measured by X-ray diffraction or the like. By combining the low-shrinkage substrate and the crystalline conductive film, the sliding property of the crystalline conductive film is remarkably improved, and the resistance value does not fluctuate even in harsh environments and the conductivity is good. A film is obtained.

As a representative of the conductive film, crystallized ITO is described below. As a method for forming ITO on the polymer film, a known method such as a DC magnetron sputtering method, an RF magnetron sputtering method, an ion plating method, or a vacuum deposition method can be used. From the viewpoint of film uniformity, the DC magnetron sputtering method is preferred. As a target for sputtering, a mixed sintered target of In ₂ O ₃ and SnO ₂ can be used. Alternatively, reactive sputtering may be performed using a metal target of In and Sn. From the viewpoint of productivity, it is preferable to use a mixed sintered target.
The concentration of SnO ₂ in the In—Sn—O material is not particularly limited, but is preferably 2 to 20 wt%, and In—Sn— having 4 to 13 wt% SnO ₂ from the viewpoint of reducing the resistance value. O-based materials are preferred.
It is possible to deposit ITO on the polymer film by sputtering using the In—Sn—O target thus selected. ITO formed by sputtering is generally amorphous. The method for crystallizing this is not particularly limited, and a known method can be used as appropriate. It is considered that the influence on the generation of crystal nuclei in the ITO film is largely due to the atmosphere during sputtering and the partial pressure of oxygen to be added. In general, when the oxygen partial pressure to be added is increased, indium oxide is stoichiometrically close to In ₂ O ₃ , and thus tends to be a crystal nucleus. In order to avoid the influence of residual gas as much as possible in the film forming atmosphere, the degree of vacuum is preferably 10 ⁻⁶ Torr or less. It is preferable to introduce oxygen together with an inert gas such as argon gas after controlling the residual gas in the vacuum chamber, and the partial pressure of oxygen is preferably 1 to 10 × 10 ⁻⁵ Torr. Nitrogen, water, etc. may be added.

Conversion to crystalline ITO is usually carried out by keeping it in a bath set at a temperature between 100 ° C. and 200 ° C. for several minutes or longer. In the PET film of the present invention, it is preferably carried out in the range of 100 ° C. to 200 ° C. in view of deformability and efficiency. Especially preferably, it is 120 to 170 degreeC. It can be carried out while continuously feeding the film or batchwise. The atmosphere during the overheat treatment is preferably air, but there is no problem even if nitrogen or the like is mixed. The crystal particle diameter is preferably 0.5 μm or less because disconnection is likely to occur if the crystal particle diameter is large from the viewpoint of bending resistance.
The thickness of the ITO layer can be selected depending on the properties required for TP, such as conductivity and transparency, but it is usually preferably 50 mm or more from the viewpoint of conductivity, and 400 mm or less from the viewpoint of transparency. preferable.

  The temperature at which sputtering is performed is not particularly limited as long as a resistance value suitable for TP can be imparted, but is preferably 60 ° C to 200 ° C. In order to sufficiently oxidize the ITO film and improve the adhesion of the ITO film, the temperature is preferably 60 ° C. or higher, more preferably 100 ° C. or higher. If it is 200 ° C. or higher, the oligomer remaining in the PET film may be precipitated and become cloudy, and the PET substrate may be deformed, which is not preferable. Thus, even during sputtering, a high temperature is required, and thus warpage may occur. However, the PET film stabilized by the thermosetting resin of the present invention has a feature that warpage does not occur.

  When a high refractive material is attached under the conductive film or on the opposite surface of the PET film and a low refractive material is attached thereon, a low reflection conductive film can be obtained. The high refractive material can be deposited by attaching titanium oxide or zirconium oxide by a technique such as vapor deposition or sputtering, or by containing these particles in a material that is cured by ultraviolet rays or heat. The low refractive material can be deposited by depositing SiOx (x = 1 to 2) or the like, which is a dielectric shown below, by vapor deposition or sputtering, or by curing a fluorine-based resin with heat or ultraviolet rays. This layer for low reflection may be applied on either side of the PET film or on both sides for further low reflection. In recent years, the demand for TP having a high transmittance has increased, and an antireflection layer can be preferably used.

It may be preferable to form a transparent dielectric thin film on the conductive thin film because the transparency and scratch resistance may be further improved. The dielectric thin film is preferably smaller than the refractive index of the conductive thin film, usually having a refractive index of 1.3 to 1.8. For example, CaF ₂ , MgF ₂ , Al ₂ O ₃ , SiOx (x = 1-2) and the like are used, and among these, SiOx is inexpensive and preferable. These materials can be used in combination of two or more. The film thickness of the dielectric is not particularly limited, but is usually 100 to 3000 mm, preferably 200 to 1500 mm. When it is thin, it is difficult to obtain a continuous thin film. When it is too thick, conductivity and transparency are deteriorated and cracks are likely to occur.

  Further, when the conductive film is used in a display device or the like, fingerprints or dirt may be generated on the surface thereof during processing or use. In order to solve this problem, a water repellent or antifouling layer can be attached to the outermost layer surface opposite to the surface on which the conductive film is formed. Examples of the material having such an effect include a fluorine-containing resin such as a silicon-containing compound, a polytetrafluoroethylene, a polychlorotrifluoroethylene, or the like containing a combination of a dimethylpolysiloxane containing a hydroxyl group or a vinyl group and a methylhydropolysiloxane. In addition, molybdenum sulfide or the like is used alone or in combination. These formation methods are not particularly limited, and a coating method, a spray method, a vacuum deposition method, a sputtering method, a baking method, or the like can be used depending on the material to be used. The thickness of the treatment layer is not particularly limited, but is usually about 100 to 50 μm. This treatment can be carried out in combination of two or more, and is efficient when used in combination with a curable resin.

The conductive film of the present invention has good sliding resistance in the above-described configuration, but the above-mentioned base is the first base, and an adhesive layer is provided on the surface of the first base opposite to the conductive film. And may further have a second substrate. Here, not only the first substrate but also the second substrate can be further improved in sliding resistance by setting the thermal shrinkage rate to 0.5% or less by the method already described. Only the first substrate may have a low shrinkage, but it is preferable that both the substrates have a low shrinkage using the method of the present invention because the effect of sliding resistance is increased.
As a configuration having such a second substrate, for example, a transparent substrate may be bonded to the other surface of the low-shrinkable substrate on which the conductive thin film is formed via a transparent adhesive layer. For this bonding, a pressure-sensitive adhesive layer may be provided on a transparent substrate, and a low-shrinkage substrate on which the conductive thin film is formed may be bonded to the transparent substrate. A pressure-sensitive adhesive layer may be provided on the shrinkable substrate, and a transparent substrate may be bonded thereto. From the viewpoint that the pressure-sensitive adhesive layer can be continuously formed with the film base as a roll, it is advantageous in terms of productivity to provide the pressure-sensitive adhesive layer on the low-shrinkage substrate.

In addition, for example, a second transparent substrate is bonded to the first substrate with low shrinkage via a transparent adhesive layer, and the total thickness is 40 to 300 μm. A conductive thin film may be provided.
The adhesive layer can be used without particular limitation as long as it has transparency, and examples thereof include an acrylic adhesive, a silicone adhesive, and a rubber adhesive. From the viewpoint of improving the scratch resistance and hit point characteristics of the conductive film, the elastic modulus is set in the range of 1 × 10 ⁵ to 1 × 10 ⁷ dyn / cm ² , and the thickness is set to 1 μm or more, usually in the range of ⁵ to 100 μm. It is desirable to do. When the above elastic modulus is less than 1 × 10 ⁵ dyn / cm ² , the pressure-sensitive adhesive layer becomes inelastic. Therefore, it is easily deformed by pressurization, causing irregularities in the substrate and the conductive thin film, and the processed cut surface. The pressure-sensitive adhesive sticks out easily from the surface, and the effect of improving the scratch resistance and the spot characteristics is reduced. On the other hand, if the elastic modulus exceeds 1 × 10 ⁷ dyn / cm ² , the pressure-sensitive adhesive layer becomes hard and the cushioning effect cannot be expected, so the scratch resistance and the hitting point characteristics cannot be improved, and the effect of bonding cannot be expected. . Further, when the thickness of the pressure-sensitive adhesive layer is less than 1 μm, the cushioning effect cannot be expected, so that the scratch resistance and the hit point characteristics cannot be improved, and the effect of bonding cannot be expected. If the thickness is too large, the transparency may be impaired, and it is difficult to obtain good results in terms of forming an adhesive layer, bonding workability of a transparent substrate, and cost.

  When the second transparent substrate bonded through the pressure-sensitive adhesive layer in the configuration having the second substrate is required to be flexible even after bonding, the plastic film is When flexibility is not particularly required, a glass plate or a film-like or plate-like plastic is used. When the transparent substrate is a plastic film, it may be the aforementioned low-shrinkage PET film or another plastic film. Specific examples of the film material include polyimide, polyethersulfone, polyetheretherketone, polycarbonate, polypropylene, polyamide, polyacryl, acetylcellulose, polyarylate, polysulfone, and norbornene-based polymers. The norbornene-based polymer includes a polymer obtained by ring-opening polymerization or addition polymerization of a monomer having a norbornene structure and another polymerizable monomer added as necessary. Trade names ZEONEX and ZEONOR, which are non-polar norbornene-based polymers, trade names Arton, which is a polar norbornene-based polymer from JSR Corporation, and trade names, Apel and Hext, developed by Mitsui Chemicals, Inc. Examples thereof include, but are not limited to those listed here, and polymers containing norbornene-based structures are included.

  In the configuration having the second substrate, the thickness of the second transparent substrate bonded via the pressure-sensitive adhesive layer is preferably in the range of 2 to 300 μm. If it is thinner than 2 μm, the mechanical strength is not obtained and the significance of making a laminated structure is scarce, and it is difficult to apply a pressure-sensitive adhesive layer in the form of a roll or to perform a continuous operation such as a hard coating process described later. In addition to this, wrinkles or the like may occur in pasting. From such a viewpoint, the thickness is preferably 10 μm or more, and particularly preferably 20 μm or more. When the thickness is 300 μm or more, the roll shape causes a curl, and not only continuous work is difficult, but also the curl remains and cannot be used. From such a viewpoint, the preferable thickness is 250 μm or less, and particularly preferably 230 μm or less.

  As described above, according to the present invention, the conductive film is attached to a substrate having a contraction rate in the longitudinal direction (MD) and the transverse direction (TD) of 0.5% or less when heated at 150 ° C. for 1 hour. When the substrate includes at least a biaxially stretched polyethylene terephthalate film, the conductive film is a metal oxide conductive film and includes 50% by weight or more of a crystallized portion, when used as an electrode of TP, Even when exposed to high temperatures in the manufacturing process, there is no warping, the electrode position is small, the resistance value does not fluctuate even in harsh environments, and a conductive film with extremely improved sliding resistance can be obtained. It was. In particular, a conductive film obtained by attaching a conductive film to a substrate obtained by curing a crosslinkable resin on a PET film while heat-treating at 100 to 180 ° C. was extremely excellent in the above-mentioned sliding resistance.

  The method for producing a conductive film for a touch panel of the present invention is a substrate having at least a biaxially stretched PET film and a cured layer on which a crosslinkable substance is cured and formed, and heated at 150 ° C. for 1 hour. A base preparation step for preparing a base body having a shrinkage ratio of 0.5% or less in both the longitudinal direction (MD) and the transverse direction (TD), and a conductive film for attaching the conductive film to the base body prepared by the base body preparation step An adhesion process and a crystallization process in which the substrate on which the conductive film is adhered is heat-treated at 100 ° C. to 250 ° C. In the substrate preparation step, at least one cured layer is formed on the PET film at 100 ° C. to 180 ° C. Simultaneously with the heat treatment at a temperature between 0 ° C. or after the PET film is heat treated at a temperature between 100 ° C. and 180 ° C., And also cured on one surface is formed by curing deposited. According to the manufacturing method of the present invention, there is no warpage even when exposed to high temperatures in the manufacturing process, the electrode position is less distorted, the resistance value does not fluctuate even in harsh environments, and the sliding resistance is greatly improved. A conductive film can be obtained.

  The most effective method is a method in which a heat-crosslinking type resin is first applied to a PET film, and is dried and cured at a temperature of 100 ° C. to 180 ° C. for several minutes to several hours. According to this method, the dimensional stability and thermal stability of the PET film can be simultaneously performed in one step, and a conductive film having extremely excellent sliding resistance can be produced. Although the process is two steps, it is also possible to heat-treat the PET film at 100 ° C. to 180 ° C. in advance and apply and cure a resin that crosslinks with heat, light or electron beam. The PET film obtained by curing the crosslinkable material thus obtained is further laminated with a crosslinkable cured layer according to the purpose. A conductive layer such as ITO is attached to the PET film on which the cured layer is laminated. In the present invention, before the conductive layer such as inorganic ITO is attached, it is necessary that the PET film has a reduced shrinkage with respect to heat and is stabilized.

In the substrate preparation step, at least one cured layer is crosslinked after the PET film is heat-treated at a temperature between 100 ° C. and 180 ° C. and before the PET film is cooled to room temperature. According to the method of curing this material on at least one surface of the PET film and forming a cured film, it is possible to easily produce a conductive film having good sliding resistance.
In particular, using a biaxially stretched PET film that has not been subjected to a low shrinkage treatment, a cured layer that has been crosslinked and cured by heat is subjected to heat treatment at a temperature between 100 ° C. and 180 ° C. and at least one of the PET films. It is possible to use an inexpensive material by curing it on the surface, eliminating the need for a heat treatment process on the PET film in advance, and having less resistance variation even under harsh environments, and being resistant to sliding. A very good conductive film can be produced.

Hereinafter, the present invention will be described more specifically with reference to examples.
Example 1 A biaxially stretched 188 μm thick PET film (A4300 manufactured by Toyobo Co., Ltd.) was continuously supplied with a gravure coater on a roll at a tension of 10 kg / cm ² with an acrylic resin (Soken) A solution prepared by dissolving 100 parts by weight of U-230 (chemical) and 30 parts by weight of a curing agent (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) in 100 parts by weight of toluene was applied so that the thickness of the coating layer after drying was 2 μm.
Acrylic resin simultaneously with drying while supplying this continuously to a drying furnace consisting of four chambers each having a length of 5 m set at 120 ° C., 140 ° C., 150 ° C. and 130 ° C. at a rate of 2 m / min. Was cured. Let the obtained film be the film A1.
A direct current type sputtering apparatus capable of continuously supplying the film A1 in a roll shape on the surface opposite to the coated surface of the film A1 in an atmosphere of 0.30 Pa composed of 80% argon gas and 20% oxygen. A transparent amorphous conductive thin film made of a composite oxide (ITO) of indium oxide and tin oxide having a thickness of 25 nm is attached by a reactive sputtering method using a target made of a tin alloy (tin 6 wt%), A transparent conductive film (film B1) having a total light transmittance of 88.2% and a surface resistance value of 420Ω / □ was obtained. The B1 film was heat-treated for 24 hours with a hot air dryer maintained at 150 ° C., and the conductive thin film was crystallized to obtain a film B2. The thermal contraction rate of the film A1 is shown in Table 1, the characteristic values of the film B2 are shown in Table 2, and the characteristics of the film B2 as the TP electrode are shown in Tables 3 and 4.
(Comparative Example 1) Tables 2 to 4 show the evaluation results of the characteristics of the film B1 in Example 1 before performing the heat treatment (crystallization) for 24 hours with a hot air dryer maintained at 150 ° C.

Example 2 A film B4 was obtained in the same manner as in Example 1 except that ITO was attached to the coated surface of the film A1 instead of attaching ITO to the surface opposite to the coated surface of the film A1. . The evaluation results are shown in Tables 1 to 4.
(Comparative Example 2) Tables 2 to 4 show the evaluation results of the characteristics of the film (film B3) before being subjected to heat treatment (crystallization) for 24 hours with a hot air dryer maintained at 150 ° C in Example 2. It was.

(Example 3) After obtaining the film A1 in the same manner as in Example 1, 100 parts by weight of Aurex 344 made of Chinese paint and 5 parts of Irgacure 184 were added to 100 parts by weight of toluene. The solution (coating agent solution) obtained in this way was continuously applied with a die coater to a thickness of 3 μm, consisting of the same four chambers as in Example 1, and set to 70 ° C., 100 ° C., 110 ° C., and 90 ° C. The film was supplied to the drying oven at 20 m / min and dried, and then irradiated with ultraviolet rays with a 120 W / cm high-pressure mercury lamp and cured to obtain a film A3. In the same manner as in Example 1, ITO was attached to the surface opposite to the coated surface of the film A3, and heat treatment was performed to obtain a film B5. The evaluation results of the characteristics are shown in Tables 1 to 4.

(Example 4) On the coated surface of the film A1 obtained in Example 1, 5 parts by weight of silica particles having an average particle diameter of 4 μm were added to the coating agent solution of Example 3, and a solution mixed uniformly was used. The film A4 was obtained by applying, drying and curing in the same manner as in Example 3. ITO was adhered to the surface opposite to the coated surface of this film A4 in the same manner as in Example 1, and then heat treatment was performed to obtain a film B6. The evaluation results of the characteristics are shown in Tables 1 to 4.

(Example 5) A solution obtained by adding 2 parts by weight of silica particles having an average particle diameter of 4 μm to the coating agent solution of Example 3 on the surface opposite to the coating surface of the film A3 obtained in Example 3 and mixing them uniformly. Was coated, dried and cured in the same manner to obtain a film A5 coated on both sides. ITO was attached to the coated surface of the film A5 containing silica particles in the same manner as in Example 1, and heat treatment was performed for 24 hours with a hot air drier maintained at 150 ° C. to obtain a film B8. The evaluation results of the characteristics are shown in Tables 1 to 4.
(Comparative Example 3) Tables 2 to 4 show the evaluation results of the characteristics of the film (film B7) before being subjected to the heat treatment (crystallization) for 24 hours in the hot air dryer maintained at 150 ° C. in Example 5. .

(Example 6) The same coating liquid as in Example 4 was applied to the surface opposite to the coating surface of the film A4 obtained in Example 4, dried and cured to obtain a double-side coated film A6. In the same manner as in Example 1, ITO was adhered to the first coated surface of the film A6, and heat treatment was performed to obtain a film B9. The evaluation results of the characteristics are shown in Tables 1 to 4.

(Examples 7-9) Using the film A3 of Example 3, the film A5 of Example 5, and the film A6 of Example 6, the TiO ₂ layer has a thickness of 500 mm and the SiO ₂ layer has a thickness of 600 mm under the ITO surface. Thus, after providing by sputtering method sequentially, ITO was made to adhere and heat-processed like Example 1, and the film B10, the film B11, and the film B12 were obtained. The evaluation results of the characteristics are shown in Tables 1 to 4.

Example 10 A biaxially stretched 188 μm thick PET film (A4300, manufactured by Toyobo Co., Ltd.) was diluted with toluene from Aurex 344 made in China paint of Example 3 in a die coater so as to have a thickness of 6 μm. While being continuously fed at a tension of 10 kg / cm ^2, it is dried through a four-room drying oven set at 80 ° C., 100 ° C., 120 ° C., and 150 ° C., and then 120 W / cm The film was cured by irradiating with ultraviolet light with a high pressure mercury lamp to obtain a film A7. ITO was adhered to the surface of the film A7 that was not coated in the same manner as in Example 1, and heat treatment was performed to obtain a film B13. The evaluation results of the characteristics are shown in Tables 1 to 4.

(Example 11) A coating liquid containing silica particles of Example 5 was applied to the surface opposite to the coated surface of film A7 of Example 10 in the same manner as in Example 5, dried and cured to obtain film A8. . TiO ₂ , SiO ₂ , and ITO having the same structure as in Example 7 were sequentially attached to the coated surface of the film A8 containing silica particles by sputtering, and heat treatment was performed to obtain a film B14. The evaluation results of the characteristics are shown in Tables 1 to 4.

Example 12 A 188 μm thick Toyobo A4300 roll was allowed to stand in a thermostatic layer set at 150 ° C. for 24 hours for heat treatment. A UV curable coating solution similar to that in Example 4 was applied thereto, dried and cured in the same manner as in Example 4 to obtain A9. In the same manner as in Example 4, ITO was attached to A9 and heat treatment was performed to obtain a film B15. The evaluation results of the characteristics are shown in Tables 1 to 4.

Comparative Example 4 A biaxially stretched 188 μm thick PET film (A4300 manufactured by Toyobo) (film A2) was coated with ITO in the same manner as in Example 1 without applying a coating solution. In the same manner as above, heat treatment was performed to obtain a film B16. The evaluation results of these characteristics are shown in Tables 1 to 4.

(Comparative Example 5) A solution prepared by diluting the Chinese paint Aurex 344 of Example 3 with toluene was applied to one side of the film A12 so as to have a thickness of 6 μm, and the film was formed at 80 ° C., 100 ° C., 100 ° C., 100 ° C. After drying through a drying furnace consisting of four chambers set with a UV irradiation with a 120 W / cm high-pressure mercury lamp, the film A10 is obtained, and ITO is applied and heat-treated in the same manner as in Example 1. And film B17 was obtained. The evaluation results of the characteristics are shown in Tables 1 to 4.

Evaluation was performed as follows.
(Heat shrinkage)
The thermal contraction rate was calculated from the dimensions before and after the heat treatment after the 10 cm square film A was left in an electric furnace set at 150 ° C. for 1 hour and then cooled to room temperature.
(Resistance value)
The resistance values in Table 2 were determined by measuring 50 points at equal intervals of 700 mm in width and 1 m in length using the 4-terminal method, and calculating the average value.
(Transmittance)
For the transmittance, the transmittance of light having a wavelength of 550 nm was measured using a spectral transmittance meter.
(Pencil hardness)
The pencil hardness was set to a hardness that did not scratch 10 times with a load of 500 g using Mitsubishi Uni.
(Haze value)
The haze value was calculated by measuring parallel transmittance and diffuse transmittance with a haze meter.
(Sledge)
For the warp, 10 cm square film B was left in an electric furnace set at 150 ° C. for 60 minutes, and the lift of the edge was measured.
(Linear slidability and character slidability)
For linear slidability and character slidability, a TP module was prepared through glass ITO and a spacer, and a slidability test was performed.
The linear sliding resistance is 0.8R polyacetal pen with a load of 250g and 500g and reciprocated 50,000 times for 100,000 times and 150,000 times for 300,000 times. And the rate of increase in resistance value from the initial value was calculated.
Character sliding resistance was also measured in the same manner as the linear sliding test.
(Resistance value change due to high temperature and humidity)
An ITO film 210 mm square sample was placed in a high-temperature and high-humidity bath at 60 ° C. 90% or 85 ° C. 85%, and after maintaining for 240 hours, the resistance value of the film was measured to show the rate of change from the initial resistance value.

  As shown in the examples, the conductive film for a touch panel of the present invention has a small warp after heat treatment at 150 ° C. for 1 hour and is subjected to a linear and character sliding test when used as an electrode of TP. It can be seen that the change in the resistance value is small, and the TP electrode has extremely excellent environmental resistance and durability.

  The transparent conductive film of the present invention can be used as a transparent electrode for displays such as TP.

FIG. 1A is a diagram illustrating an example of a conductive film for a touch panel according to the present invention. FIG. 1B is a diagram showing another example of the conductive film for a touch panel of the present invention. FIG. 1C is a diagram showing another example of the conductive film for a touch panel of the present invention. FIG. 1D is a diagram illustrating another example of the conductive film for a touch panel of the present invention. FIG. 1E is a diagram showing another example of the conductive film for a touch panel of the present invention. FIG. 1F is a diagram illustrating another example of the conductive film for a touch panel according to the present invention.

Claims (8)

The substrate shrinkage of not more than either 0.5% in the longitudinal direction when heated pressurized one hour at 0.99 ° C. (MD) and transverse direction (TD), obtained by depositing a conductive film, said substrate A touch panel comprising at least a biaxially stretched polyethylene terephthalate film and a cured layer formed by curing a crosslinkable substance , wherein the conductive film is a metal oxide conductive film and includes 50% by weight or more of a crystallized portion. Conductive film. The conductive film for a touch panel according to claim 1, wherein the substrate has a cured layer in which a thermally crosslinkable substance is cured and formed as a cured layer. The conductive film for a touch panel according to claim 2, wherein the base further has a cured layer in which a crosslinkable substance by light or electron beam is cured and formed. The conductive film for a touch panel according to claim 3, wherein the substrate has a cured layer formed by curing a crosslinkable substance by light or electron beam on both sides of the polyethylene terephthalate film. The conductive film for a touch panel according to claim 1, wherein the conductive film is indium tin oxide. A conductive film is attached to a substrate that has been pretreated so that the thermal shrinkage in the MD and TD directions is 0.5% or less when heated at 150 ° C. for 1 hour, and then further heated to 100 ° C. to 250 ° C. The transparent conductive film according to claim 1, wherein the heat treatment is performed. At least one cured layer is crosslinked after the polyethylene terephthalate film is heat treated at a temperature between 100 ° C. and 180 ° C. or after the polyethylene terephthalate film is heat treated at a temperature between 100 ° C. and 180 ° C. The conductive film for a touch panel according to claim 6, wherein the conductive film is obtained by curing at least one surface of the polyethylene terephthalate film. A substrate having at least a biaxially stretched polyethylene terephthalate film and a cured layer on which a crosslinkable substance is cured and formed, which is heated in the longitudinal direction (MD) and transverse direction (TD) when heated at 150 ° C. for 1 hour. A substrate preparation step of preparing a substrate having a shrinkage rate of 0.5% or less, a conductive film attachment step of attaching a conductive film to the substrate prepared by the substrate preparation step, and a substrate to which the conductive film is attached. A crystallization step in which heat treatment is performed at 100 ° C. to 250 ° C., and in the substrate preparation step, at least one layer of the cured layer is subjected to heat treatment at a temperature between 100 ° C. and 180 ° C. at the same time as the polyethylene terephthalate film. Alternatively, after the polyethylene terephthalate film is heat-treated at a temperature between 100 ° C. and 180 ° C., the crosslinkable substance is added to the polyethylene. Method for producing a conductive film for the touch panel, and forming and curing the film formation by curing at least one surface of terephthalate film.

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