JP5727641B2 - Light transmissive conductive film, method for producing the same, and use thereof - Google Patents

Description

  The present invention relates to a light-transmitting conductive film, a manufacturing method thereof, and an application thereof.

  As a light-transmitting conductive film mounted on a touch panel, light transmission containing indium tin oxide (ITO) or the like directly or via another layer on at least one surface of a light-transmitting support layer made of plastic or the like Many light-transmitting conductive films having a conductive conductive layer are used.

  In many cases, the above-described film is used after a light-transmitting conductive layer (or further including the layer if any) is patterned by an etching process. When such a film is viewed from the top of the film surface on the side of the light-transmitting conductive layer, the same layer does not exist in the region (pattern region) where the light-transmitting conductive layer (or its upper layer) exists on the surface. A region where the lower layer is exposed (etching region) is observed. The pattern shape is, for example, a strip shape. In such a film, it is known that a so-called bone appearance phenomenon occurs in which the pattern shape is visually recognized.

  Although such a bone appearance phenomenon is an event caused by a plurality of factors, it is considered that a local deformation caused by etching processing contributes as one factor.

  For the purpose of suppressing this bone appearance phenomenon, for the purpose of suppressing local deformation itself, a sufficiently thick layer (for example, about 188 μm) may be used as a light-transmitting support layer as a film substrate, or another film may be used. Further, it has been proposed to bond them together. However, in recent years, there is a demand for thin and light films (for example, about 50 μm), and such means cannot be employed.

  Therefore, for the purpose of suppressing the bone appearance phenomenon, a method has been proposed in which fine irregularities are formed on the surface of the etching region to give a relatively high haze value and blur the appearance of the etching region (patent). Reference 1).

Japanese Patent Application Laid-Open No. 2012-133771

  In the light-transmitting conductive film in which the light-transmitting conductive layer is patterned, the present inventor has formed fine irregularities on the surface of the etched region according to the conventional technique for the purpose of improving the bone appearance phenomenon. Although there is a tendency to suppress the bone appearance phenomenon, this is an effect brought about by clouding the entire film, and not only the bone appearance phenomenon but also the display image itself when used on a touch panel. I found that there is a problem that it becomes difficult to see. In other words, the present inventor has found that the conventional method has a problem that the haze value becomes too high and the brightness of the screen is lowered when used on a touch panel. Furthermore, the present inventor has also found that there is another problem that the electrical resistance value of the light-transmitting conductive layer is increased when irregularities are formed on the surface of the etching region in the same manner according to the prior art. .

  Therefore, the present invention has improved the balance of three points of (1) the degree of suppression of the bone appearance phenomenon when the light-transmitting conductive layer is patterned, (2) haze value, and (3) electrical resistance value. An object is to provide a light-transmitting conductive film.

  The present inventor has conducted intensive studies and provided an intermediate layer having a plurality of protrusions having a convex curved surface having a relatively large curvature on the lower layer side of the light-transmitting conductive layer so that the surfaces having the protrusions face each other. The present inventors have found that the above problems can be solved. More details are as follows. By setting it as above-mentioned, it can be set as the state where multiple convex curved surfaces which have a larger curvature than the conventional one exist on the surface of the etching region. As a result, it is possible to effectively shake the interface reflection while suppressing the irregular reflection. Furthermore, when it is intended to suppress the bone appearance phenomenon by providing the protrusions having such a shape, the object can be achieved even if the number of protrusions per unit area is smaller than that of the conventional method. Thus, as a result, the bone appearance phenomenon can be effectively suppressed while maintaining the state in which the film surface is less disturbed, that is, the state in which the deterioration of the haze value and the electrical resistance value is suppressed as compared with the conventional case.

The present invention has been completed by further various studies based on these new findings, and is as follows.
Item 1
(A) a light transmissive support layer;
(B) an intermediate layer; and (C) a light transmissive conductive layer,
The intermediate layer (B) is disposed on at least one surface of the light transmissive support layer (A) directly or via one or more other layers, and the light transmissive conductive layer (C). Is a light transmissive conductive film disposed on at least one surface of the light transmissive support layer (A) via at least the intermediate layer (B):
The surface on the light-transmissive conductive layer (C) side of the intermediate layer (B) has a plurality of protrusions having a convex curved surface, and an angle θ between the convex curved surface and the surface of the intermediate layer (B) is A light-transmitting conductive film, characterized by being 50 ° or less.
Item 2
Item 2. The light transmissive conductive film according to Item 1, wherein the surface of the intermediate layer (B) has 100 to 10,000 protrusions per 1 mm ² .
Item 3
The intermediate layer (B) comprises a flat ellipsoid or spindle-shaped fine particle having a major axis (Major Axis) of 1 μm to 10 μm and an aspect ratio of the major axis to the minor axis of 1.5 or more, and a binder component. Containing, and the protrusion is formed by the fine particles,
Item 3. The light transmissive conductive film according to Item 1 or 2.
Item 4
Item 4. The light transmissive conductive film according to Item 3, wherein a difference in refractive index between the fine particles and the binder component is 0.1 or less.
Item 5
Item 5. The light transmittance according to any one of Items 1 to 4, wherein an average value of maximum heights of the protrusions with respect to the surface of the intermediate layer (B) as a reference surface is 0.1 μm to 1 μm. Conductive film.
Item 6
Item 6. The light-transmitting conductive material according to any one of Items 1 to 5, wherein at least a part of the light-transmitting conductive layer (C) is patterned and has a region where the intermediate layer (B) is exposed. the film.
Item 7
The touchscreen containing the light transmissive conductive film as described in any one of claim | item 1 -6.
Item 8
A method for producing the light transmissive conductive film according to any one of Items 3 to 6,
(1) A method comprising a step of forming the intermediate layer (B) using a raw material containing the binder component and the fine particles.
Item 9
Item 9. The method according to Item 8, wherein in the step (1), the intermediate layer (B) is formed by applying the raw material on a layer serving as a base.

  According to the present invention, a plurality of convex curved surfaces having relatively large curvatures can be present on the surface of the etching region, and as a result, interface reflection is effectively suppressed while suppressing irregular reflection. Can be shaken. According to the present invention, it is possible to effectively suppress the bone appearance phenomenon while appropriately suppressing the haze value.

It is sectional drawing which shows the light transmissive conductive film of this invention by which the intermediate | middle layer (B) and the light transmissive conductive layer (C) are arrange | positioned in this order on the single side | surface of a light transmissive support layer (A). . It is sectional drawing which shows the light transmissive conductive film of this invention by which an intermediate | middle layer (B) and a light transmissive conductive layer (C) are arrange | positioned in this order on both surfaces of a light transmissive support layer (A). . The first intermediate layer (B) and the light transmissive conductive layer (C) are disposed in this order on one surface of the light transmissive support layer (A), and the second surface is disposed on the other surface. It is sectional drawing which shows the light transmissive conductive film of this invention in which the intermediate | middle layer (B) is directly arrange | positioned. It is sectional drawing of the etching area | region of the state in which the some convex curve with comparatively large curvature exists on the surface of an etching area | region. It is sectional drawing of the etching area | region in the state in which the some convex curve with comparatively small curvature exists on the surface of an etching area | region. FIG. 4 is a top view, a side view, and a partially enlarged view showing a state in which fine particles partially embedded in the intermediate layer (B) protrude from the surface of the intermediate layer (B). It is a three-view figure which shows the external appearance of the fine particle of a flat ellipsoid. It is a trihedral view showing the appearance of flat spindle-shaped fine particles. It is a trihedral view showing the appearance of a spherically-shaped fine particle whose split plane does not pass through the center of the sphere. It is a schematic diagram which shows the processus | protrusion formed by irregularly shaped particle | grains. It is a schematic diagram which shows the protrusion formed of the protrusion provided in the lower layer of the intermediate | middle layer (B). It is a schematic diagram which shows the processus | protrusion formed by transcription | transfer of a type | mold. It is a schematic diagram which shows the protrusion formed by post-processing. The light-transmitting conductive material of the present invention has an intermediate layer (B), an undercoat layer (D), and a light-transmitting conductive layer (C) arranged in this order on one side of the light-transmitting supporting layer (A). It is sectional drawing which shows a film. The light-transmitting conductive material of the present invention, in which an intermediate layer (B), an undercoat layer (D), and a light-transmitting conductive layer (C) are arranged in this order on both surfaces of the light-transmitting support layer (A). It is sectional drawing which shows a film.

1. Light transmissive conductive film The light transmissive conductive film of the present invention comprises:
(A) a light transmissive support layer;
(B) an intermediate layer; and (C) a light transmissive conductive layer,
The intermediate layer (B) is disposed on at least one surface of the light transmissive support layer (A) directly or via one or more other layers, and the light transmissive conductive layer (C). Is a light transmissive conductive film disposed on at least one surface of the light transmissive support layer (A) via at least the intermediate layer (B):
The surface on the light-transmissive conductive layer (C) side of the intermediate layer (B) has a plurality of protrusions having a convex curved surface, and an angle θ between the convex curved surface and the surface of the intermediate layer (B) is It is a light-transmitting conductive film characterized by being 50 ° or less.

  In the present invention, “light-transmitting” means having a property of transmitting light (translucent). “Light transmissivity” includes transparency. “Light transmissivity” means, for example, the property that the total light transmittance is 80% or more, preferably 85% or more, more preferably 87% or more. In the present invention, the total light transmittance is measured based on JIS-K-7105 using a haze meter (trade name: NDH-2000 manufactured by Nippon Denshoku Co., Ltd. or equivalent).

  In this specification, when mentioning the relative positional relationship between two layers among a plurality of layers arranged on one surface of the light transmissive support layer (A), the light transmissive support layer (A) is used as a reference. One layer having a large distance from the light transmissive support layer (A) is referred to as “upper layer” and the like, and the other layer having a small distance from the light transmissive support layer (A) is referred to as “lower layer”. And so on.

  Unless otherwise specified in the following description of each layer, in the present invention, the thickness of each layer is a commercially available reflection spectral film thickness meter (Otsuka Electronics, FE-3000 (product name), or equivalent). Use to find. Alternatively, it may be obtained by observation using a commercially available transmission electron microscope. Specifically, the light-transmitting conductive film is thinly cut in a direction perpendicular to the film surface using a microtome or a focus ion beam, and the cross section is observed.

  In FIG. 1, the one aspect | mode of the transparent electroconductive film of this invention is shown. In this embodiment, the intermediate layer (B) and the light transmissive conductive layer (C) are arranged in this order on one surface of the light transmissive support layer (A).

  FIG. 2 shows another embodiment of the light transmissive conductive film of the present invention. In this embodiment, the intermediate layer (B) and the light transmissive conductive layer (C) are arranged in this order on both surfaces of the light transmissive support layer (A).

1.1 Light transmissive support layer (A)
In the present invention, the light transmissive support layer refers to a light transmissive conductive film containing a light transmissive conductive layer, which plays a role of supporting the layer containing the light transmissive conductive layer. Although it does not specifically limit as a light transmissive support layer (A), For example, in the light transmissive conductive film for touch panels, what is normally used as a light transmissive support layer can be used.

  Although the raw material of a light-transmissive support layer (A) is not specifically limited, For example, various organic polymers etc. can be mentioned. The organic polymer is not particularly limited. For example, polyester resin, acetate resin, polyether resin, polycarbonate resin, polyacrylic resin, polymethacrylic resin, polystyrene resin, polyolefin resin, polyimide resin, etc. Examples include resins, polyamide resins, polyvinyl chloride resins, polyacetal resins, polyvinylidene chloride resins, and polyphenylene sulfide resins. Although it does not specifically limit as polyester-type resin, For example, a polyethylene terephthalate (PET), a polyethylene naphthalate (PEN), etc. are mentioned. The material of the light transmissive support layer (A) is preferably a polyester resin, and particularly preferably PET. The light transmissive support layer (A) may be composed of any one of these, or may be composed of a plurality of types.

  Although the thickness of a light-transmissive support layer (A) is not specifically limited, For example, the range of 2-300 micrometers is mentioned.

1.2 Intermediate layer (B)
In the light transmissive conductive film of the present invention, the intermediate layer (B) is disposed on at least one surface of the light transmissive support layer (A) directly or via one or more other layers. The intermediate layer (B) is preferably disposed directly on the surface of the light transmissive support layer (A).

  The intermediate layer (B) may be directly disposed on both surfaces of the light transmissive support layer (A) (FIG. 3).

  The intermediate layer (B) has a plurality of protrusions having a convex curved surface on the side facing the light transmissive conductive layer (C), and an angle formed by the convex curved surface and the surface of the intermediate layer (B). It has the characteristic that θ is 50 ° or less.

  The protrusion has a feature that it has a convex curved surface having a relatively large curvature (a gentle curved surface). Due to such characteristics, an excellent effect of suppressing the bone appearance phenomenon while suppressing an increase in haze value can be obtained. For example, although an increase in haze value is suppressed as compared with a case where a protrusion having a curved surface with a smaller curvature (a sharp curved surface), for example, an intermediate layer (B) having a spherical protrusion instead, is used. The bone appearance phenomenon is effectively suppressed. In view of the above effects, the protrusion preferably further has a feature that it does not have or substantially does not have a bent surface.

This phenomenon is explained as follows. By arranging the intermediate layer (B), a plurality of convex curved surfaces having a relatively large curvature can be present on the surface of the etching region after etching. A cross-sectional view of the etching region in this state is shown in FIG. For comparison with the present invention, FIG. 5 shows a cross-sectional view of an etching region when a convex curved surface having a relatively small curvature is present on the surface of the etching region. Each of FIGS. 4 and 5 shows the light reflected from the surface of the etching region of light incident from a certain angle.
In this way, when a convex curved surface with a relatively large curvature is introduced on the surface, the reflected light is less likely to scatter than when a convex curved surface with a relatively small curvature is introduced, and the reflected light is more in a certain range. Easy to fit in. Thus, when reflected light is hard to scatter, the raise of a haze value can be suppressed. Further, even when a convex curved surface having a relatively large curvature is introduced on the surface, it is possible to effectively fluctuate the interface reflection that is considered to cause the bone appearance phenomenon.

  In terms of the effect of the present invention, the angle θ between the convex curved surface and the surface of the intermediate layer (B) is preferably 5 to 50 °, more preferably 15 to 30 °.

In the present invention, the angle θ formed by the convex curved surface and the surface of the intermediate layer (B) is measured as follows.
<Measurement method of θ>
1. Removal of upper layer by etching process (pre-measurement process)
The light-transmitting conductive film is immersed in 20% hydrochloric acid, and the etching process is continued until the surface resistance cannot be measured.

2. Method for Measuring θ A three-dimensional surface shape was measured using a non-contact type three-dimensional surface roughness meter under the conditions of a measurement magnification of 25 times and a measurement area of 283 μm × 213 μm. From the obtained three-dimensional surface shape, 25 convex curved surfaces were arbitrarily selected. The three-dimensional surface shape of each convex curved surface was viewed from an arbitrary direction, and the “angle between the roughness measurement reference surface and the convex curved surface” was calculated. The 25 calculated “angles between the roughness measurement reference surface and the convex surface” are arithmetically averaged, and “the convex surface becomes the surface of the intermediate layer (B) on the light-transmissive conductive layer (C) side. Angle θ ”.

In terms of the effect of the present invention, it is preferable that the surface of the intermediate layer (B) facing the light-transmissive conductive layer (C) has 100 to 10,000 protrusions per 1 mm ^2. 500 to 5,000 are more preferable, and 1,000 to 2,000 are more preferable.

  In the present invention, the number of protrusions per unit area is measured as follows.

<Method for measuring the number of protrusions per unit area>
1. Removal of upper layer by etching process (pre-measurement process)
The light-transmitting conductive film is immersed in 20% hydrochloric acid, and the etching process is continued until the surface resistance cannot be measured.

2. Method for measuring the number of protrusions Using a surface analysis software built in the non-contact type three-dimensional surface roughness meter, the three-dimensional 10-point average roughness (SRz) is obtained, and “the intermediate layer (B) having the protrusions” is calculated. The average value of the maximum heights of the protrusions with the surface as a reference surface.

  In terms of the effect of the present invention, the average value of the maximum height of the protrusions with the surface of the intermediate layer (B) having the protrusions as a reference surface is preferably 0.1 μm to 1 μm, preferably 0.2 μm to 0 μm. More preferably, the thickness is 6 μm.

  In the present invention, the average value of the maximum height of the protrusions is calculated as follows.

<Method of calculating the average value of the maximum height of the protrusions>
1. Removal of upper layer by etching process (pre-measurement process)
The light-transmitting conductive film is immersed in 20% hydrochloric acid, and the etching process is continued until the surface resistance cannot be measured.

2. Measuring method of maximum height of protrusion and average value thereof A three-dimensional surface shape is measured using a non-contact type three-dimensional surface roughness meter under conditions of a measurement magnification of 25 times and a measurement area of 283 μm × 213 μm. The maximum roughness (SRmax) of the protrusion and the three-dimensional 10-point average roughness (SRz) are obtained using surface analysis software incorporated in the non-contact type three-dimensional surface roughness meter. The maximum roughness (SRmax) of the protrusion is “the maximum height of the protrusion with the surface of the intermediate layer (B) having the protrusion as a reference surface”, and the three-dimensional 10-point average roughness (SRz) is “the protrusion. The maximum height of the protrusion with the surface of the intermediate layer (B) having a reference surface as the reference surface.

  In addition, when another layer having a thickness of several tens of nanometers such as an undercoat layer exists on the surface of the intermediate layer (B), the other layer was directly covered with the other layer without being removed. The uneven shape on the surface may be measured.

The protrusions are not particularly limited, but may correspond to, for example, a portion of fine particles partially embedded in the intermediate layer (B) protruding from the surface of the intermediate layer (B) (FIG. 6). ).
The shape of the fine particles is not particularly limited as long as it has the convex curved surface in part. For example, in addition to an ellipsoid, the shape shown in FIGS. The fine particles are not particularly limited, but a flat ellipsoid or spindle shape having a major axis (Major Axis) of 1 μm to 10 μm and an aspect ratio of a major axis to a minor axis of 1.5, or a shape similar thereto. Can be used. More specifically, an ellipsoid having a major axis (Major Axis) of 3 μm to 6 μm and an aspect ratio of a major axis to a minor axis of 2 or more can be used. The upper limit of the aspect ratio is not particularly limited, but is preferably 10 or less.

  As another aspect, the protrusion may be a protrusion formed by a peripheral binder component being raised, reflecting the shape of the fine particles or irregular fine particles that are entirely embedded in the intermediate layer (B). (FIG. 10). The deformed shape in this case is not particularly limited as long as it has a conical shape illustrated in FIG. For example, when conical fine particles as shown in FIG. 10 are embedded in the intermediate layer (B), the protrusion having a convex curved surface having a relatively large curvature (curved curved surface) as described above due to the wraparound of the binder component. Is formed.

  As another embodiment, the protrusion may be a protrusion provided on the lower layer of the intermediate layer (B) protruding from the surface of the intermediate layer (B) (FIG. 11). Similarly, the protrusion is a protrusion provided in the lower layer of the intermediate layer (B), and the peripheral binder component is raised to reflect the shape of the protrusion that is entirely embedded in the intermediate layer (B). It may be a projection formed by doing so.

  As another embodiment, the protrusion may be provided on the surface of the intermediate layer (B) by mold transfer (FIG. 12).

  As another aspect, after forming the intermediate layer (B), the protrusion may be provided on the surface of the intermediate layer (B) by post-processing (printing, inkjet, or the like) (FIG. 13).

  In the present invention, the volume average particle diameter of the fine particles is measured by an electric resistance test method using a Coulter counter type particle size meter.

  In the present invention, the aspect ratio between the major axis and minor axis of the fine particles is calculated as follows.

  A test piece having fine particles fixed in an epoxy resin is prepared, and the test piece is observed using a scanning electron microscope (SEM). Arbitrary 25 particles are selected from within the observation field, and the maximum length of the observed outer diameter of each particle is measured. If the number of particles observed is less than 25, the observation field is changed or a plurality of fields are observed to obtain a total of 25 measurement values.

  The fine particles are not particularly limited, but preferably, transparent organic polymer particles, transparent inorganic particles, organic-inorganic hybrid particles, and the like can be used.

  In the above, preferably, the intermediate layer (B) contains the fine particles and a binder component. The binder component is not particularly limited, and examples thereof include acrylic resins, silicone resins, melamine resins, and alkyd resins; and colloidal particles such as silica, zirconia, titania, and alumina. The intermediate layer (B) may contain any one of them as a binder component, or may contain a plurality of types as a binder component.

  In the above, it is preferable that the refractive index difference between the fine particles and the binder component is 0.1 or less. If the refractive index difference is within this range, it is preferable because uniform transmitted light can be obtained over the entire surface of the film when light is transmitted. What is necessary is just to select a material suitably so that a refractive index difference may exist in this range.

  The intermediate layer (B) is not particularly limited as long as the effects of the present invention are exhibited, but may further contain other components in addition to the fine particles. The other components are not particularly limited as long as the effects of the present invention are exhibited. For example, acrylic resins, silicone resins, melamine resins, and alkyd resins; and colloidal particles such as silica, zirconia, titania, and alumina. And silicon-based organic-inorganic hybrid polymers. In addition to the fine particles, the intermediate layer (B) may further contain any one of them, or may further contain a plurality of types.

  The thickness of the intermediate layer (B) is 0.5 to 5 μm, preferably 1 to 4 μm, more preferably 1 to 3 μm. When the thickness of the intermediate layer (B) is larger than 0.5 μm, there is an advantage that the particles are difficult to drop off. Further, when the thickness of the intermediate layer (B) is smaller than 5 μm, there is an advantage that the uniformity of the protrusion height is increased.

  In the present invention, the thickness of the intermediate layer (B) is measured as follows. Obtained by observation with a transmission electron microscope. Specifically, a light-transmitting conductive film is cut into thin pieces using a microtome or a focus ion beam, and the cross section is observed.

  The intermediate layer (B) can also be a layer having other additional functions. For example, you may provide the function as an optical adjustment layer to an intermediate | middle layer (B) simultaneously. In this case, the intermediate layer (B) may have, for example, a multilayer structure in which the upper portion has a low refractive region and the lower portion has a high refractive index region, and the boundary may not be clear.

  The method for disposing the intermediate layer (B) on the underlying layer is not particularly limited. For example, a method of applying a raw material to a film and then curing with heat, and an active energy such as ultraviolet rays or electron beams. Examples include a method of curing with a wire. From the viewpoint of productivity, a method of curing with ultraviolet rays is preferable.

More specifically, when the intermediate layer (B) contains the binder component and the fine particles, the intermediate layer (B) can be disposed on the underlying layer as follows.
(1) It can arrange | position by the method containing the process of forming the said intermediate | middle layer (B) using the raw material containing the said binder component and the said microparticles | fine-particles. In the step (1), it is more preferable to form the intermediate layer (B) by applying the raw material on a layer serving as a base.

  Alternatively, a desired protrusion can be provided on the surface of the intermediate layer (B) by a method such as imprinting without using the fine particles as described above.

1.3 Light transmissive conductive layer (C)
The light transmissive conductive layer (C) is disposed on one surface of the light transmissive support layer (A) directly or via one or more other layers.

  In the present invention, the light-transmitting conductive layer means a layer that conducts electricity and transmits visible light. Although it does not specifically limit as a light transmissive conductive layer (C), For example, what is normally used as a light transmissive conductive layer in the light transmissive conductive film for touch panels can be used.

  The material of the light transmissive conductive layer (C) is not particularly limited, and examples thereof include indium oxide, zinc oxide, tin oxide, and titanium oxide. The light transmissive conductive layer (C) is preferably a light transmissive conductive layer containing indium oxide doped with a dopant in terms of achieving both transparency and conductivity. The light transmissive conductive layer (C) may be a light transmissive conductive layer made of indium oxide doped with a dopant. Although it does not specifically limit as a dopant, For example, a tin oxide, a zinc oxide, those mixtures, etc. are mentioned.

In the case of using indium oxide doped with tin oxide as the material of the light transmissive conductive layer (C), indium oxide (III) (In ₂ O ₃ ) doped with tin oxide (IV) (SnO ₂ ) (Tin-doped indium oxide; ITO) is preferable. In this case, the addition amount of SnO ₂ is not particularly limited, and examples thereof include 1 to 15% by weight, preferably 2 to 10% by weight, and more preferably 3 to 8% by weight. Moreover, you may use as a raw material of a light-transmitting conductive layer (C) what added the other dopant to indium tin oxide in the range which the total amount of a dopant does not exceed the numerical range of the left description. Although it does not specifically limit as another dopant in the left, For example, selenium etc. are mentioned.

  The light transmissive conductive layer (C) may be composed of any one of the various materials described above, or may be composed of a plurality of types.

  The light transmissive conductive layer (C) is not particularly limited, but may be a crystalline or amorphous body, or a mixture thereof.

  The method for disposing the light transmissive conductive layer (C) may be either wet or dry, and is not particularly limited. Specific examples of the method for disposing the light transmissive conductive layer (C) include a sputtering method, a vacuum deposition method, an ion plating method, a CVD method, and a pulse laser deposition method.

1.4 Undercoat layer (D)
The light transmissive conductive film of the present invention has an undercoat layer directly or via one or more other layers on the surface of the light transmissive support layer (A) where the light transmissive conductive layer (C) is disposed. (D) may be arranged. When the undercoat layer (D) is disposed, at least one of the light transmissive conductive layers (C) is disposed at least through the undercoat layer (D) and the intermediate layer (B). It is arranged on the surface of (A). In this case, at least one of the light transmissive conductive layers (C) may be disposed adjacent to the undercoat layer (D). In this case, the undercoat layer (D) is usually disposed closer to the light transmissive conductive layer (C) than the intermediate layer (B).

  In FIG. 4, the one aspect | mode of the transparent electroconductive film of this invention is shown. In this embodiment, the intermediate layer (B), the undercoat layer (D), and the light transmissive conductive layer (C) are arranged adjacent to each other in this order on one surface of the light transmissive support layer (A). Yes.

  In FIG. 10, the one aspect | mode of the transparent electroconductive film of this invention is shown. In this embodiment, the intermediate layer (B), the undercoat layer (D), and the light transmissive conductive layer (C) are arranged adjacent to each other in this order on both surfaces of the light transmissive support layer (A).

  In FIG. 11, the one aspect | mode of the transparent electroconductive film of this invention is shown. In this embodiment, the first intermediate layer (B), the undercoat layer (D), and the light transmissive conductive layer (C) are adjacent to each other in this order on one surface of the light transmissive support layer (A). The second intermediate layer (B) is disposed directly on the other surface.

  Although the material of an undercoat layer (D) is not specifically limited, For example, you may have a dielectric property. The material for the undercoat layer (D) is not particularly limited. For example, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon alkoxide, alkylsiloxane and its condensate, polysiloxane, silsesquioxane, and Examples include polysilazane. The undercoat layer (D) may be composed of any one of them, or may be composed of a plurality of types. A light-transmitting underlayer containing silicon oxide is preferable, and a light-transmitting underlayer made of silicon oxide is more preferable.

  One layer of the undercoat layer (D) may be disposed. Alternatively, two or more layers may be arranged adjacent to each other or separated from each other via other layers.

  As for the thickness per layer of an undercoat layer (D), 15-40 nm etc. are mentioned. When two or more layers are disposed adjacent to each other, the total thickness of all the undercoat layers (D) adjacent to each other may be within the above range. In the example list shown on the left, the following are more preferable than the above.

  The method of disposing the undercoat layer (D) may be either wet or dry, and is not particularly limited. Examples of the wet include a sol-gel method and a method of applying a fine particle dispersion or colloid solution. It is done. Examples of the method for disposing the undercoat layer (D) include a method of laminating on an adjacent layer by a sputtering method, an ion plating method, a vacuum deposition method, or a pulse laser deposition method.

1.5 Other layers The light-transmitting conductive film of the present invention is provided on the surface of the light-transmitting support layer (A) where the intermediate layer (B) and the light-transmitting conductive layer (C) are disposed. At least one layer selected from the group consisting of the undercoat layer (D) and at least one other layer (E) may be further disposed.

  Although it does not specifically limit as another layer (E), For example, an adhesive layer etc. are mentioned.

  The adhesive layer is a layer that is disposed between two layers so as to be adjacent to each other and to adhere the two layers to each other. Although it does not specifically limit as a contact bonding layer, For example, what is normally used as a contact bonding layer in the transparent conductive film for touchscreens can be used. Although not particularly limited, for example, a coupling agent can be used. Corona treatment may be performed for the purpose of further improving the adhesion to one surface or both surfaces to be bonded as required.

1.6 Use of light-transmitting conductive film of the present invention The light-transmitting conductive film of the present invention is preferably used for touch panels. The light-transmitting conductive film of the present invention is particularly preferably used for a capacitive touch panel. A light-transmitting conductive film used for manufacturing a resistive touch panel generally requires a surface resistivity (sheet resistance) of about 160 to 1,000 Ω / sq. On the other hand, a light-transmitting conductive film used for manufacturing a capacitive touch panel generally has a lower surface resistivity. The light-transmitting conductive film of the present invention has a reduced resistivity, and is thus preferably used for the production of a capacitive touch panel. The details of the capacitive touch panel are as described in 2.

2. Capacitive touch panel of the electrostatic capacitance type touch panel <br/> invention of the present invention comprises a light transmissive, electrically-conductive film of the present invention, comprise other members according to necessity.

Specific examples of the configuration of the capacitive touch panel according to the present invention include the following configurations. The protective layer (1) side is used so that the operation screen side faces, and the glass (5) side faces the side opposite to the operation screen.
(1) Protective layer (2) Light transmissive conductive film of the present invention (Y-axis direction)
(3) Insulating layer (4) Light transmissive conductive film of the present invention (X-axis direction)
(5) Glass Although the capacitive touch panel of the present invention is not particularly limited, for example, it can be produced by combining the above (1) to (5) and other members as required according to a usual method. it can.

3. Production method of light transmissive conductive film of the present invention The light transmissive conductive film of the present invention can be produced by disposing each layer as described for each layer. For example, the light-transmissive support layer (A) may be sequentially disposed on the surface on which the light-transmissive conductive layer (C) is disposed from the lower layer side, but the arrangement order is not particularly limited. For example, first, another layer may be disposed on one surface of a layer that is not the light-transmissive support layer (A) (for example, the light-transmissive conductive layer (C)). Alternatively, one composite layer is obtained by arranging two or more layers adjacent to each other on the one hand, or at the same time, two or more layers are similarly disposed adjacent to each other on the other side. Thus, one type of composite layer may be obtained, and these two types of composite layers may be further arranged adjacent to each other.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
PET was used as the light transmissive support layer. An intermediate layer was formed by uniformly applying the coating liquid shown below on the PET surface and drying the resin liquid. The thickness of the obtained intermediate layer was 1.5 μm. The convex / concave shape of the convex surface appearing on the surface of the intermediate layer is measured using a three-dimensional surface roughness meter, the angle θ between the convex surface and the intermediate layer (B), the number of protrusions per unit area, the light of the intermediate layer The average value of the maximum height with the surface on the transparent conductive layer (C) side as the reference surface was determined. The obtained results are shown in Table 1. The coating solution was prepared as follows.

(Preparation of coating solution)
Dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd.) 75 parts by weight Epoxy acrylate (Nippon Kayaku Co., Ltd.) 20 parts by weight Macromonomer AA-6 (Toagosei Co., Ltd.) 11 parts by weight Photopolymerization initiator Irgacure 184 (Ciba Geigy) 7 parts by weight Ellipsoidal styrene resin fine particles 1 part by weight (volume average particle diameter 3 μm, aspect ratio 2, major axis length 4 μm, minor axis length 2 μm)
The above components were diluted with a mixed solvent of 35 parts by weight of butyl cellosolve and 94.5 parts by weight of methyl ethyl ketone, and stirred well to obtain a coating solution having a solid content of 40%.

A layer made of SiO ₂ (n _C = 1.460) having a thickness of 20 nm is formed as an optical interference layer on the intermediate layer, and a layer made of indium tin oxide (n _D = n = 4) is further formed thereon as a light-transmitting conductive layer. 1.938) was deposited to a thickness of 25 nm. Subsequently, it heat-processed at 150 degreeC for 1 hour. The obtained transparent transparent conductive film was evaluated for “evaluation of bone appearance phenomenon”, “haze value”, and “electric resistance value” according to the following methods.

(Comparative Example 1)
A light-transmitting conductive film was obtained in the same manner as in Example except that the ellipsoidal fine particles contained in the coating liquid were replaced with spherical styrene resin fine particles. The results evaluated in the same manner as in Examples are shown in Table 1.

(Examples 2-18 and Comparative Examples 2-4)
The light-transmitting conductive material is the same as in Example 1, except that the shape and blending amount of the ellipsoidal fine particles contained in the coating liquid, the thickness after drying and curing, the angle θ, the number of particles, the particle size, and the protrusion height are changed. A film was obtained. The results evaluated in the same manner as in Example 1 are shown in Tables 1 and 2.
The ellipsoidal particles used are the same ellipsoidal styrene resin fine particles (volume average particle diameter 3 μm, aspect ratio 2, major axis length 4 μm, minor axis length 2 μm) as in Example 1. Spherical styrenic resin fine particles (volume average particle diameter 3 μm, aspect ratio 1) were used as the shaped particles.

(Evaluation of bone appearance phenomenon)
The produced transparent conductive laminate was cut into a 5 cm square, and 8 pieces of 3 mm-wide polyimide tape were attached to the transparent conductive layer in parallel so as to have an interval of 3 mm. Next, the laminate with the polyimide tape attached is immersed in an ITO etching solution (trade name “ITO-06N”, manufactured by Kanto Chemical Co., Ltd.) for 1 minute to remove the ITO where the polyimide tape is not attached, and rinse. And the polyimide tape was peeled after drying, and the laminated body by which the ITO film | membrane of 3 mm width was patterned by the 3 mm space | interval was obtained. This film was visually observed to evaluate whether the ITO pattern corresponds to one of “not visible (な い)”, “substantially invisible (◯)”, and “slightly visible (×)”.

(Total light transmittance and haze value)
It measured according to JISK7361-1 using the Nippon Denshoku company haze meter (MDH2000).

(Electric resistance value)
The surface resistance was measured by a four-terminal method using a surface resistance meter (manufactured by MITSUBISHI CHEMICAL ANALYTECH, trade name: Loresta-EP).
The evaluation results are shown in Tables 1 and 2. “(Blending amount) *” in Tables 1 and 2 indicates the part by weight of the particles when the amount of the particles in Example 1 is 1 part by weight.

1 Light-transmissive conductive film 11 Light-transmissive support layer (A)
12 Middle layer (B)
121 Fine particles 122 Binder 13 Light transmissive conductive layer (C)
14 Undercoat layer (D)
15 Lower layer of intermediate layer (B) (may be light transmissive support layer (A))
151 Lower layer projection 2 Mold 3 Projection provided by post-processing

Claims (9)

(A) a light transmissive support layer;
(B) an intermediate layer; and (C) a light transmissive conductive layer,
The intermediate layer (B) is disposed on at least one surface of the light transmissive support layer (A) directly or via one or more other layers, and the light transmissive conductive layer (C). Is a light transmissive conductive film disposed on at least one surface of the light transmissive support layer (A) via at least the intermediate layer (B):
The surface on the light-transmissive conductive layer (C) side of the intermediate layer (B) has a plurality of protrusions having a convex curved surface,
And the angle (theta) which the said convex curve makes with the said surface of the said intermediate | middle layer (B) is 5-40 degrees, The light-transmitting conductive film characterized by the above-mentioned. The light-transmitting conductive film according to claim 1, wherein the surface of the intermediate layer (B) has 100 to 10,000 protrusions per 1 mm ² . The intermediate layer (B) is a flat ellipsoid having a major axis (Major Axis) of 1 μm to 10 μm and an aspect ratio of a major axis to a minor axis of 1.5 or more, or fine particles having a shape similar thereto, and a binder Containing the components, and the protrusions are formed by the fine particles.
The light-transmitting conductive film according to claim 1. The light-transmitting conductive film according to claim 3, wherein a difference in refractive index between the fine particles and the binder component is 0.1 or less. The light transmittance as described in any one of Claims 1-4 whose average value of the maximum height which makes the said surface of the said intermediate | middle layer (B) the reference | standard surface of the said protrusion is 0.1 micrometer-1 micrometer. Conductive film. The light-transmitting conductive material according to any one of claims 1 to 5, wherein at least a part of the light-transmitting conductive layer (C) is patterned and has a region where the intermediate layer (B) is exposed. the film. A touch panel containing the light transmissive conductive film according to claim 1. A method for producing the light transmissive conductive film according to any one of claims 3 to 6,
(1) A method comprising a step of forming the intermediate layer (B) using a raw material containing the binder component and the fine particles. The method according to claim 8, wherein in the step (1), the intermediate layer (B) is formed by applying the raw material on a layer serving as a base.

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