JP5526542B2 - Laminated film for touch panel - Google Patents

Description

  The present invention relates to a laminated film for a touch panel in which a hard coat layer and a transparent conductive thin film layer are laminated on at least one surface of a substrate made of a polyester film. In particular, the present invention relates to a transparent conductive film used for a finger input touch panel that can be operated by a person touching a screen.

A transparent conductive film obtained by laminating a transparent thin film having a low resistance on a substrate made of a polyester film is widely used as a transparent electrode of a touch panel.
In recent years, cases where touch panels are used in mobile devices such as mobile phones and mobile music terminals have increased.
The finger touch panel is used in a characteristic way that it is repeatedly pressed, so it is durable and transparent considering screen visibility, anti-glare properties, fingerprint smudges, and easy to remove stains. As a required characteristic, many patents have been filed and known for manufacturing methods and products.
However, conventionally known transparent conductive films are intended to solve only the physical requirements of strong, transparent and non-staining, and people who feel how the surface feels when they touch it. Manufacturing that considered the senses and sensibilities of was not made. Therefore, there is no disclosure of a technique related to a study for improving the tactile sensation when touching with a finger or the like.

On the other hand, in recent years, transparent touch panels using a transparent conductive film are frequently used. A transparent touch panel inputs predetermined information or the like to a computer or the like by pressing a predetermined position with a finger or a pen. When a predetermined position is pressed with a finger or a pen, reflection of external light and reflected light generated at the interface with the air layer become very problematic, making it difficult to view the screen. In addition, so-called Newton's rings occur due to distortion caused by pressing of the transparent conductive film, and the transparent conductive layer of the transparent conductive film is repeatedly contacted and non-contacted. The so-called sticking occurred and there was a problem. For this reason, in order to prevent reflection of external light on the substrate surface, a method for preventing reflection by forming an inorganic vapor deposition layer, a method for providing a hard coat layer containing fine particles such as silica, and applying a matte coating have been proposed. ing. Furthermore, it has been proposed to provide a transparent conductive layer on a roughened film.
For this purpose, it has been studied to provide protrusions on the surface (Patent Documents ~).
However, these touch panel films described in Patent Documents 1 to 4 can improve slipperiness and antiglare properties, but are not considered to improve the tactile sensation when touching with a finger, and are comfortable to humans. Providing a touch panel that has a tactile sensation has not been sufficiently achieved.
JP-A-6-322164 JP 2002-36452 A JP 2003-45234 A JP 2008-110550 A

  In view of the above-described conventional problems, an object of the present invention is to provide a transparent conductive laminated film for a touch panel having excellent tactile sensation when touched with a finger.

This invention is made | formed in view of the above situations, Comprising: The laminated film for touchscreens which could solve said subject consists of the following structures.
1. A laminated film in which a hard coat layer is laminated on one side of a substrate made of a polyester film and a transparent conductive layer made of a metal oxide is laminated on the other side, and the hard coat layer is averaged in the cured resin A porous silica fine particle having a particle diameter of 2.0 to 7 μm and a pore volume of 1.7 ml / g or more is blended, and 1 to 3 mass of the porous silica fine particle is added to 100 parts by mass of the cured resin. The surface average roughness of the hard coat layer is 0.08 to 0.30 μm, the average friction coefficient MIU of the KES surface friction characteristic value is 0.13 to 0.17, and the variation MMD of the friction coefficient is 0. A laminated film for a touch panel, which is 0.006 to 0.015 .

  The laminated film for a touch panel of the present invention is designed for surface characteristics of the touch surface of the finger based on the result of sensory evaluation of the touch feeling that the monitor is actually touched with a finger after being incorporated in the touch panel. A touch panel can be provided.

The laminated film for a touch panel of the present invention is a laminated film in which a hard coat layer is laminated on one surface of a substrate made of a polyester film, and a transparent conductive layer made of a metal oxide is laminated on the other surface, Touch panel designed to have excellent tactile sensation when touched with a finger based on the sensory evaluation results of the coating layer area surface average roughness Sa, KES surface friction characteristic value average friction coefficient MIU, friction coefficient variation MMD Laminated film.
Hereinafter, each layer will be described in detail.

(Base material made of polyester film)
Examples of the substrate made of the polyester film used in the present invention include a biaxially stretched film made of polyethylene terephthalate or polyethylene-2,6-naphthalate.
As a raw material for the polyester film used in the present invention, a copolyester resin may be used, or another organic polymer may be blended. Particularly preferred is a biaxially stretched film made of polyethylene terephthalate.

It is preferable that the thickness of the base material which consists of a polyester film used by this invention is 10-300 micrometers, More preferably, it is 70-260 micrometers. If the thickness of the plastic film is less than 10 μm, the mechanical strength is insufficient, which is not preferable. On the other hand, if the thickness exceeds 300 μm, the thickness of the touch panel becomes too thick, which is not suitable for mobile devices.
Further, the substrate made of the polyester film used in the present invention preferably has high transparency, and the total light transmittance is preferably 88% or more, more preferably 90% or more, and particularly preferably 92% or more. . A highly transparent biaxially stretched film made of polyethylene terephthalate that does not contain fine particles for forming surface protrusions, and Cosmo Shine (registered trademark) manufactured by Toyobo Co., Ltd. is preferred.

  The substrate made of a polyester film used in the present invention is a corona discharge treatment, a glow discharge treatment, a flame treatment, in a range that does not impair the purpose of the present invention in order to increase the adhesion with the hard coat layer and the transparent conductive thin film layer. Surface activation treatment such as ultraviolet irradiation treatment, electron beam irradiation treatment, and ozone treatment may be performed.

  The base material comprising the polyester film used in the present invention has an anchor coat coating layer for the purpose of improving adhesion with a hard coat layer and a transparent conductive thin film layer, imparting chemical resistance, and preventing precipitation of low molecular weight substances such as oligomers. May be provided. The coating method for providing the coating layer is not particularly limited, and conventionally known methods such as a bar coating method, a gravure coating method, and a reverse coating method can be employed. The thickness of the coating layer is preferably in the range of 0.01 to 1 μm.

(Hard coat layer)
In order to provide scratch resistance of the outermost layer (pen input surface) when used as a touch panel, the surface opposite to the transparent conductive thin film surface of the base film (the outermost layer input surface when used as a touch panel) It is preferable to provide a coat layer. The hard coat layer preferably has a pencil hardness of 2H or more. When the hardness is less than 2H, the hard coat layer of the transparent conductive film is insufficient in terms of scratch resistance.

  Examples of the hard coat layer in the present invention include an acrylic hard coat layer and a silicone hard coat layer. The thickness of the hard coat layer is preferably 0.5 to 10 μm. If the thickness is less than 0.5 μm, the scratch resistance tends to be insufficient, and if it is thicker than 10 μm, it is not preferable from the viewpoint of productivity. More preferably, it is 2-6 micrometers.

In the present invention, the hard coat layer has an area surface average roughness Sa of 0.08 to 0.30 μm and an average friction coefficient MIU of KES surface friction characteristic value of 0.13 to 0 in order to improve the touch feeling when the touch panel is formed. .17, Fluctuation coefficient variation MMD needs to be 0.006 to 0.015, and for that purpose, it is important to provide protrusions on the surface of the hard coat layer. Examples of the method for providing protrusions on the surface of the hard coat layer include a method of blending fine particles in a cured resin and a method of embossing.
When a hard coat layer is obtained by blending fine particles in the above cured resin, fine particles are blended with the prepolymer, oligomer and / or monomer for obtaining a cured resin as a main component, and if necessary The coating liquid (hereinafter also referred to as hard coating liquid) dissolved and dispersed in an organic solvent containing a photopolymerization initiator or radical generator is coated on a substrate made of a polyester film, and then the ionizing radiation is dried while the solvent is dried. Alternatively, the hard coat layer is formed by crosslinking and curing by heat.

  Examples of the prepolymer, oligomer, and / or monomer for obtaining the cured resin used in the hard coat liquid include prepolymers, oligomers, and / or monomers such as polyfunctional acrylic resins, melamine resins, and silicone resins. Can be mentioned.

As a monomer for obtaining a cured resin used for the hard coat liquid, a monomer composed of an ultraviolet curable polyfunctional acrylate having two or more (meth) acryloyl groups in the molecule is preferable. . For example, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. A polyfunctional acrylate is mentioned.
Examples of the prepolymer and / or oligomer for obtaining the curable resin used in the hard coat liquid include polyfunctional compounds such as low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, and silicone resins. Examples include acrylate and / or methacrylate.
One kind of prepolymer, oligomer and / or monomer for obtaining these curable resins may be used, or two or more kinds thereof may be used in combination, or may be used in combination with the photopolymerizable prepolymer. Good.

As the fine particles to be blended in the hard coat liquid, those having an average particle diameter of 2.0 to 7 μm are preferably used. When the average particle size is less than 2.0 μm, sufficient unevenness cannot be imparted to the surface of the hard coat layer, so that the tactile sensation upon finger input when used for a touch panel is inferior. When the average particle size is larger than 7 μm, the surface of the film becomes too rough, the touch feeling at the time of finger input when used for a touch panel is deteriorated and the visibility is lowered, and the object of the present invention cannot be achieved.
The kind of fine particles may be inorganic particles or organic particles, but porous silica-based fine particles are preferable. In particular, those having a pore volume of 1.7 ml / g or more are preferable because the transparency of the laminated film is excellent.
The fine particles are used in a range of 0.5 to 20 parts by mass with respect to 100 parts by mass of the cured resin. When the blending amount is less than 2 parts by mass, sufficient unevenness cannot be imparted to the surface of the hard coat layer, and therefore the tactile sensation at the time of finger input when used for a touch panel is inferior. If it exceeds 25 parts by mass, the surface of the film becomes too rough, and the visibility when used for a touch panel is lowered, making it unsuitable for use in the present invention. A more preferable blending amount is 2 to 10 parts by mass, and a range of 3 to 15 parts by mass is particularly suitable. When porous silica-based fine particles having a pore volume of 1.7 ml / g or more are used as fine particles, a smaller blending amount is preferable, and a range of 1 to 3 parts by mass is preferable with respect to 100 parts by mass of the cured resin. It is. Furthermore, in addition to the above fine particles, when a fine particle having an average particle size in the range of 10 to 100 nm is used in combination, the tactile sensation at the time of finger input when used for a touch panel may be improved.

  In addition to the curable resin and fine particles, the hard coat liquid used in the present invention includes a photopolymerization initiator or a radical generator as necessary, and an antioxidant, an ultraviolet absorber, and a light stabilizer as necessary. , A leveling agent, an antifoaming agent and the like can be prepared by dissolving or dispersing in a solvent.

  Examples of the photopolymerization initiator blended in the hard coat liquid as necessary include, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, dimethylaminoacetophenone, 2-hydroxy-2-methyl-1-phenylpropane- Radical-generating photopolymerization initiators such as 1-one, 1-hydroxycyclohexyl phenyl ketone, 4- (2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, and aryldiazonium Acid-generating light such as salts, diaryliodonium salts, triarylsulfonium salts, 2-nitrobenzyl esters of sulfonic acids, iminosulfonates, 1-oxo-2-diazonaphthoquinone-4-sulfonate derivatives, etc. Initiator, and the like. If necessary, a photosensitizer such as anthracene or thioxanthone may be used in combination. These may be used alone or in combination of two or more. The compounding quantity of a photoinitiator is the range of 0.2-10 mass parts with respect to 100 mass parts of the said curable prepolymer and / or curable monomer. You may mix | blend thermal radical generators, such as a peroxide compound, as needed.

  Examples of the solvent used for the hard coat liquid include heptane, cyclohexane, toluene, xylene, methylene chloride, ethylene chloride, propanol, butanol, acetone, methyl ethyl ketone, isophorone, ethyl acetate, and ethyl cellosolve.

As a coating method for providing the hard coat layer in the present invention, for example, a bar coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method or the like can be adopted.
Examples of the method for crosslinking and curing after drying the hard coat liquid include normal heat treatment, electron beam or ultraviolet ray irradiation treatment. For example, in the case of an electron beam irradiation treatment, 50 to 50 emitted from various electron beam accelerators such as a Cockloft Walton type, a handigraph type, a resonant transformation type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type. An electron beam having an energy of 1000 keV, preferably 100 to 300 keV is used. In the case of ultraviolet irradiation treatment, an ultraviolet generator such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, or a metal halide lamp can be used.

(Area surface average roughness Sa of the hard coat layer)
It is important that the hard coat layer in the present invention has an area surface average roughness Sa of 0.08 to 0.30 μm in order to improve the tactile sensation when a touch panel is formed. When the area surface average roughness Sa is less than 0.08, the surface is too smooth, the touch feeling is deteriorated, and the touch feeling is uncomfortable. When the area surface average roughness Sa is larger than 0.25 μm, the surface roughness becomes excessively large, and the surface roughness becomes unpleasant and the touch feeling is deteriorated. Preferably, it is 0.08 to 0.25 μm, and more preferably 0.08 to 0.20 μm.

(KES friction characteristics of hard coat layer)
In the present invention, it is important that the average friction coefficient MIU of the KES surface friction characteristic value is 0.13 to 0.17 in order to improve the touch feeling when the hard coat layer is formed as a touch panel. When the average friction coefficient MIU of the KES surface friction characteristic value is less than 0.13, the surface of the touch panel is very slippery, the finger stop is poor when touched, and the touch panel is difficult to operate and uncomfortable. If it is greater than 0.17, the surface of the touch panel will be extremely slippery, and when touched, the surface will feel unnecessarily sticky and sticky, resulting in an unpleasant tactile sensation.
In the hard coat layer of the present invention, the average friction coefficient MIU of the KES surface friction characteristic value is set in the above range in order to improve the touch feeling when the touch panel is used, and the friction coefficient variation MMD is 0.006 to 0.015. It is important to. When the variation MMD of the KES surface friction characteristic value is less than 0.006, the surface is too smooth, the touch feeling is deteriorated, and the touch feeling is uncomfortable. If it is larger than 0.015, the friction coefficient fluctuates greatly, so that the surface roughness becomes excessively large and the surface becomes uncomfortable and the touch feeling deteriorates. Preferably it is 0.006-0.013, More preferably, it is 0.07-0.11 micrometer.

(Transparent conductive thin film layer)
Examples of the transparent conductive thin film in the present invention include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, and indium-zinc composite oxide. . Of these, indium-tin composite oxides are preferable from the viewpoints of environmental stability and circuit processability.
In the present invention, a transparent conductive thin film layer is laminated, and the surface resistance value of the laminated film for a touch panel is preferably 50 to 2000 Ω / □, more preferably 100 to 1500 Ω / □, so that the laminated film for the touch panel is a touch panel or the like. Can be used for When the surface resistance value is less than 50Ω / □ or exceeds 2000Ω / □, the position recognition accuracy of the touch panel is deteriorated, which is not preferable.

  The thickness of the transparent conductive thin film is preferably in the range of 4 to 30 nm, more preferably 10 to 25 nm. When the film thickness of the transparent conductive thin film is less than 4 nm, it is difficult to form a continuous thin film, and it is difficult to obtain good conductivity. On the other hand, when the film thickness of the transparent conductive thin film is larger than 30 nm, when the transparent conductive thin film layer is patterned, it becomes difficult to make the optical characteristics of the portion having the transparent conductive thin film layer close to the portion not having the transparent conductive thin film layer.

  The layer structure of the transparent conductive thin film may be a single layer structure or a laminated structure of two or more layers. In the case of a transparent conductive thin film having a laminated structure of two or more layers, the metal oxides constituting each layer may be the same or different.

As a method for forming a transparent conductive thin film in the present invention, a vacuum vapor deposition method, a sputtering method, a CVD method, an ion plating method, a spray method, and the like are known. Can be used as appropriate.
For example, in the case of the sputtering method, a normal sputtering method using an oxide target, a reactive sputtering method using a metal target, or the like is used. At this time, oxygen, nitrogen, or the like may be introduced as a reactive gas, or means such as ozone addition, plasma irradiation, or ion assist may be used in combination. In addition, a bias such as direct current, alternating current, and high frequency may be applied to the substrate as long as the object of the present invention is not impaired.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these Examples. In addition, the performance of the laminated film for touch panels was measured and evaluated by the following method.

(1) Surface roughness (region surface average roughness Sa)
Using a non-contact surface roughness meter (Ryoka System Digital Image Information Processing System Micromap VertScan), the area surface average roughness Sa was measured under an environment of 23 ° C. and 50% RH. The average value of five measurements was adopted.

(2) Friction property measurement Among the KES texture tester series manufactured by Kato Tech Co., Ltd., a KES-SE surface property tester for measuring surface properties was used. The measurement conditions were a standard friction element (fingerprint type), load during friction: low load condition (25 gf), and measurement sensitivity H (high sensitivity 20 g / V). Other conditions such as the friction distance and friction speed are as specified in the equipment specifications. (Friction distance 30 mm, analysis distance 20 mm, sample moving speed 1 mm / sec) This apparatus rubs the surface of the sample using a frictional device imitating a human fingertip, and the average friction coefficient “ Two measurement measures are obtained: "MIU" (unitless) and coefficient of friction variation "MMD" (unitless). As a texture tester, the texture (for example, surface characteristics expressed as smooth or rough) is mainly measured by physical property values. All data used in the present invention were carried out in a standard recommended environment for film measurement at 23 ° C. and 50% RH. As the number of measurements, an average value of five measurements was adopted as in the case of normal fabric measurement.

(3) Scratch resistance After scratching the surface of the hard coat layer 30 times with steel wool # 0000, the surface of the hard coat layer was visually observed for scratches. The case where was marked as x.
(4) Surface resistivity It measured by the 4-terminal method based on JIS-K-7194. As a measuring machine, Lotest AMCP-T400 manufactured by Mitsubishi Yuka Co., Ltd. was used.
(5) Sensory evaluation of tactile sensation when touched with a finger 25 healthy men and women from 20 to 50 years old, a total of 50 people were collected as subjects. Each test subject entered an environmental test chamber conditioned at 23 ° C. and 50% RH and allowed to rest in the environment for a while, and then presented all types of touch panels using the laminated films of the examples or comparative examples as samples. Then, it was touched as a touch panel for finger input, and a questionnaire and an interview survey were conducted on the tactile sensation when touched. The questionnaire items are the viewpoints of “surface slipperiness”, “feeling of sticking to fingers”, “feeling of surface roughness”, and “good touch feeling when touching with fingers”. Each item was scored by a 9-point scale of 0 to 8 points. The average value of subjects was calculated for each item, and sensory values for tactile sensation evaluation were obtained. The higher the score, the more easily the surface is slippery, the feeling of sticking to the finger, the feeling of surface roughness, and the total tactile feel when touching with a finger. Is a good direction.

[Example 1]
<Preparation of hard coat film>
Wet gel silica fine particles having an average particle size of 2.5 μm and a pore volume of 2.0 ml / g in 100 parts by mass of a photopolymerization initiator-containing ultraviolet curable acrylic resin (Daiichi Seika Kogyo Co., Ltd., Seika Beam EXF-01J) 1 part by mass of a mixed solvent of toluene / MEK (80/20: mass ratio) as a solvent was added so that the solid content concentration was 50% by mass, and the mixture was stirred and uniformly dissolved to prepare a coating solution.
On the easy-adhesion layer of a biaxially oriented transparent PET film (Toyobo Co., Ltd., A4100, thickness 188 μm) having an easy-adhesion layer on one side, the coating solution prepared so that the thickness of the coating film becomes 5 μm is It applied using. After drying at 80 ° C. for 1 minute, the coating film was cured by irradiating with ultraviolet rays (light quantity: 300 mJ / cm ² ) using an ultraviolet ray irradiation device (UB042-5AM-W type, manufactured by Eye Graphics Co., Ltd.). .

<Formation of transparent conductive thin film>
Next, a transparent conductive thin film made of indium-tin composite oxide was formed as a transparent conductive thin film layer on the opposite surface of the hard-coated biaxially oriented PET film. At this time, the pressure before sputtering was 0.0001 Pa, and the target was indium oxide containing 36% by mass of tin oxide (manufactured by Sumitomo Metal Mining Co., Ltd., density: 6.9 g / cm ³ ). DC of ² W / cm ² Power was applied. Further, Ar gas was flowed at 130 sccm, O ₂ gas was flowed at an O ₂ flow rate at which the surface resistance value was minimized, and a film was formed by DC magnetron sputtering in an atmosphere of 0.4 Pa. The center roll temperature was 0 ° C. and sputtering was performed.
<Production of touch panel>
This transparent conductive film is used as one panel plate, and the other panel plate is composed of an indium-tin composite oxide thin film (tin oxide content: 10% by mass) having a thickness of 20 nm by plasma CVD on a glass substrate. A transparent conductive thin film (Nippon Soda Co., Ltd., S500) was used. A touch panel was prepared by arranging the two panel plates with epoxy beads having a diameter of 30 μm so that the transparent conductive thin film faces each other, and used as a sample for sensory evaluation of the tactile sensation of finger input to the touch panel.

[Example 2]
A laminated film for a touch panel was produced in the same manner as in Example 1 except that the blending amount of the fine particles blended in the hard coat liquid was changed to 2 times.

Example 3
A laminated film for a touch panel was produced in the same manner as in Example 1 except that the blending amount of the fine particles blended in the hard coat liquid was changed to 3 times.

[ Reference Example 1 ]
A laminated film for a touch panel was produced in the same manner as in Example 1 except that the blending amount of the fine particles blended in the hard coat liquid was changed to 4 times.

[Comparative Example 1]
A laminated film for a touch panel was produced in the same manner as in Example 1 except that a transparent conductive thin film was formed on a biaxially oriented transparent PET film (A4340, thickness 188 μm) without hard coating.
[Comparative Example 2]
A laminated film for a touch panel was produced in the same manner as in Example 1 except that no fine particles were blended in the hard coat liquid.
[Comparative Example 3]
A laminated film for a touch panel was produced in the same manner as in Example 1 except that the amount of fine particles blended in the hard coat liquid was changed to ½.
[Comparative Example 4]
A laminated film for a touch panel was produced in the same manner as in Example 1 except that the fine particles blended in the hard coat liquid were changed to colloidal silica fine particles (Nissan Chemical Industries, Snowtex OL, average particle size 40 nm).
[Comparative Example 5]
A laminated film for a touch panel was produced in the same manner as in Example 1 except that the amount of fine particles blended in the hard coat liquid was changed to 8 times.
[Comparative Examples 6-8]
A laminated film for a touch panel was produced in the same manner as in Example 1 except that the hard coat surface of the hard coat biaxially oriented PET film produced in Comparative Example 2 was embossed, and irregularities were imparted to the hard coat surface.

From the results shown in Table 1, the laminated films for touch panels described in Examples 1 to 3 and Reference Example 1 that satisfy the scope of the present invention are “surface slipperiness” in the sensory evaluation of touch feeling performed by 50 subjects. "Score is high, easy to slip," Sucking to finger "rating is low, there is little sticking to finger," Surface roughness "score is slightly high, and the surface is slightly uneven , And “good overall tactile sensation when touched with a finger” scored as high as 4.9 or more, and the direction was excellent in tactile sensation when touched. On the other hand, the laminated films for touch panels described in Comparative Examples 1 to 7 generally have a low “slip on the surface” score, a direction in which it is difficult to slide, and a high “feel to stick to finger” score. Higher direction, “Surface roughness” rating is low or too high, outside the appropriate range of surface roughness, and “Total tactile feel when touched with a finger” rating Was as low as 4.5 or less, and was evaluated to be inferior to the touch when touched.

  The laminated film for a touch panel of the present invention gives an appropriate surface roughness and slipperiness to the touch panel input screen by using it as an upper electrode of the touch panel. A touch panel having a tactile sensation that a person feels comfortable without feeling pleasant or uncomfortable can be provided.

It is the schematic of the laminated film for touchscreens of this invention.

Explanation of symbols

1: Hard coat layer 2: Polyester film (base material)
3: Transparent conductive thin film layer

Claims (1)

A laminated film in which a hard coat layer is laminated on one side of a substrate made of a polyester film and a transparent conductive layer made of a metal oxide is laminated on the other side, and the hard coat layer is averaged in the cured resin A porous silica fine particle having a particle diameter of 2.0 to 7 μm and a pore volume of 1.7 ml / g or more is blended, and 1 to 3 mass of the porous silica fine particle is added to 100 parts by mass of the cured resin. The surface average roughness of the hard coat layer is 0.08 to 0.30 μm, the average friction coefficient MIU of the KES surface friction characteristic value is 0.13 to 0.17, and the variation MMD of the friction coefficient is 0. A laminated film for a touch panel, which is 0.006 to 0.015 .