JP5341790B2 - Touch panel film and touch panel using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film for touch panel that has long-term stable durability by preventing film peeling between an HC layer and a multilayer sputtered film even under a severe environment, and to provide a touch panel using the same. <P>SOLUTION: MS films 3 each having thickness of 30 to 300 nm are sequentially formed, comprising an HC layer 41 mainly composed of an ultraviolet-curing resin provided on one principal plane of a base film 40, a first refraction layer (middle refraction layer) 42 on the HC layer 41, a second refraction layer (lower refraction layer) 43, and a transparent conductive layer 13. In a region at the depth of at least 10 nm from a surface in contact with the MS film 3 of the HC layer 41, the ratio B/A of the number B of inorganic elements in inorganic oxide to the number A of organic elements in organic components of the layer is set to 0.05 to 0.35 in the ratio of the number of elements, and the ratio B/A is set to be constant or gradually reduce toward a depth direction from the surface. Thus, a region 410 rich in inorganic oxide components is formed. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  TECHNICAL FIELD The present invention relates to a film for a touch panel and a touch panel using the film, and particularly relates to a technique for improving the adhesion of components of the film.

2. Description of the Related Art In electronic devices such as personal digital assistants (PDAs), notebook computers, OA devices, medical devices, car navigation systems, and various manufacturing devices driven by FA, touch panels for combining input means with displays are widely used. Yes.
As a typical touch panel system, there is a resistive film type. This is a film with a transparent conductive film (film for a touch panel) in which a transparent electrode film (transparent conductive film) such as indium tin oxide (ITO) is formed on one side of a transparent planar member, and is arranged oppositely at a predetermined interval. Has a configuration. Since the touch panel has good transparency, it is directly disposed on the surface of a display such as a liquid crystal display (LCD) or an organic EL display (OELD) during use.

  In the resistive touch panel, a predetermined region of one film is pressed and deformed by a user's finger or a stylus pen, etc., and input is made by bringing the film into contact with the other film and energizing it. Therefore, the base film which is the main material of the transparent planar member is required to have transparency and sufficient input resistance (for example, pen input durability and keystroke durability). Polyethylene terephthalate (PET), polycarbonate (PC), norbornene A transparent film material such as a cyclic olefin resin is used. Further, a hard coating layer (hereinafter simply referred to as “HC layer”) formed of an ultraviolet curable resin or the like is disposed on the surface, thereby improving the strength.

In addition to the resistive touch panel, there are other types of touch panels such as ultrasonic, optical, and capacitive touch panels. In particular, a capacitive touch panel can incorporate multi-touch and gestures as an input function, and thus has become popular in recent years.
In the capacitive touch panel, position detection is performed by using a current flowing through the capacitance between the finger and the transparent electrode, which is generated when the surface is touched with the finger. One of the transparent electrodes is used for X-coordinate detection and the other is used for Y-coordinate detection, and these can be positioned oppositely to detect the position. The difference between the electrodes is that the electrodes are insulated by the entire surface bonding of a plastic film or an adhesive.

By the way, in the film for touch panels in recent years, further enhancement of functionality has been sought. For example, as shown in the transparent conductive film described in Patent Document 1, a film in which an inorganic layer such as silicon oxide (SiO ₂ ) is laminated on the surface of the HC layer of the transparent planar member (hereinafter simply referred to as “MS film”) In some cases, good transparency can be ensured. A transparent electrode made of indium tin oxide (ITO) or the like is disposed on the outermost surface of the plurality of inorganic layers such as silicon oxide (SiO ₂ ).

Japanese Patent No. 3366864 JP-A-9-123333 JP-A-8-294989 Japanese Patent Laid-Open No. 8-62590 WO2008 / 069217 JP 2008-165984 A

However, such a conventional film for a touch panel has a problem that it is difficult to say that the adhesion between the laminated layers is sufficient.
That is, the touch panel is generally used in the atmosphere with the display, but is subjected to various temperature and humidity changes and external light irradiation depending on the use environment. In applications such as outdoor applications and navigation systems, touch panels are more susceptible to the effects of sunlight, ultraviolet irradiation, high temperature, and high humidity environments than indoor applications. When used in factories or public facilities, it may be continuously irradiated by various illumination light sources such as mercury lamps.

  During such storage or immediately after the start of use for the touch panel, oxygen and water vapor in the environmental atmosphere diffuse and penetrate into the interface between the MS film and the HC layer of the touch panel film. In this state, for example, when ultraviolet light or light on the short wavelength side of visible light (for example, light with a wavelength of 300 nm to 550 nm) is irradiated from the outside at a high illuminance for a long time, the HC layer in contact with the MS film is extremely exposed. Oxidation and hydrolysis occur in the shallow surface region (about 10 nm or less). As a result of these chemical reactions, the organic polymer constituting the resin on the surface of the HC layer becomes low in molecular weight, and there is a possibility that the adhesiveness with the MS film may be ultimately lowered.

This problem of light resistance is a problem that should be solved by all means in order to continue to use the touch panel well.
The present invention has been made in view of the above problems, and even in a harsh environment, it prevents a decrease in adhesion between the HC layer and the MS film and exhibits stable light resistance over a long period of time. It aims at providing the film for touch panels which can be used, and a touch panel using the same.

  In order to solve the above problems, the present invention provides a film for a touch panel in which an ultraviolet curable resin layer and a transparent inorganic oxide layer are sequentially laminated on one surface of a transparent substrate, and the thickness of the transparent inorganic oxide layer Is 30 nm or more and 300 nm or less, and the ultraviolet curable resin layer comprises both an organic component and an inorganic oxide, and at least the organic layer in the layer in a region within a depth of 10 nm from the surface in contact with the transparent inorganic oxide layer. The ratio B / A of the number B of inorganic elements in the inorganic oxide to the number A of organic elements in the component was 0.05 to 0.35 in terms of the element number ratio.

Here, the inorganic oxide contains at least one element of Si, Zr, Sn, and Sb,
The ratio B / A can be defined as the ratio of the number of elements (Si + Zr + Sn + Sb) / C between the sum of each element constituting the inorganic oxide contained in the ultraviolet curable resin layer and the organic component carbon. In this case, the ratio B / A can be set to be constant or gradually decreased from the surface in the depth direction in the ultraviolet curable resin layer.

Further, the present invention is a touch panel film in which an ultraviolet curable resin layer and a transparent inorganic oxide layer are sequentially laminated on one surface of a transparent substrate, and the thickness of the transparent inorganic oxide layer is 30 nm or more and 300 nm or less. The ultraviolet curable resin layer has an average primary particle size of 5 to 40 nm and is composed of inorganic oxide fine particles (inorganic oxide) made of at least one of SiO ₂ , ZrO ₂ , SnO ₂ , and antimony tin oxide (ATO). It is also possible to adopt a configuration in which so-called nanoparticles made of a product are dispersed in a range of 20 wt% to 90 wt%. By adjusting in this way, the ratio B / A of the inorganic oxide to the organic component in the region 10 nm deep from the surface in contact with the transparent inorganic oxide film layer is in the range of 0.05 to 0.35. can do.

In addition, it is desirable that the inorganic oxide in the present invention does not contain TiO ₂ . This is because TiO ₂ has the property of accelerating the decomposition reaction of the organic component in the presence of light due to its photocatalytic activity, so when present in the ultraviolet curable resin layer, the resin layer deteriorates relatively early, This is because the adhesion between the MS film and HC may be reduced. However, in the actual manufacturing process, TiO ₂ may be mixed at an impurity level (for example, 2 wt% or less in the ultraviolet curable resin layer). Small enough to be ignored.

Here, the transparent inorganic oxide layer can also be comprised by the multilayered structure which laminated | stacked at least 2 or more types of different layers.
In addition, the transparent inorganic oxide layer may be formed by laminating a first layer having a first refractive index and a transparent conductive film in the same order from the ultraviolet curable resin layer side.
Alternatively, the transparent inorganic oxide layer includes, from the ultraviolet curable resin layer side, a second layer having a second refractive index different from the first refractive index, a first layer having the first refractive index, and a transparent conductive material. It can also be set as the structure formed by laminating | stacking a film | membrane in the same order.

Alternatively, the transparent inorganic oxide layer may be a transparent conductive film directly disposed on the ultraviolet curable resin layer, and the transparent conductive film may have a thickness of 30 nm or more.
Alternatively, the transparent inorganic oxide layer includes a second layer having a second refractive index different from the first refractive index and a first layer having the first refractive index on the ultraviolet curable resin layer. It is also possible to laminate in order and repeat the lamination of the second layer and the first layer two or more, and a transparent conductive film is formed on the other surface of the transparent substrate. In this case, one of the first layer and the second layer can be composed of an inorganic oxide layer containing one or more of TiO ₂ , Ta ₂ O ₅ , and Nb ₂ O _5. It is. Also, one of the first layer and the second layer can be composed of an inorganic oxide layer containing at least one of SiO ₂ and SnO ₂ .

Alternatively, a layer containing a fluorosilane or fluorine resin is laminated on the uppermost surface of the transparent inorganic oxide layer, and a transparent conductive film is formed on the other surface of the transparent substrate. .
Alternatively, the transparent inorganic oxide layer is formed by laminating a low density siloxane layer on an ultraviolet curable resin layer, and an ultraviolet curable resin layer and a transparent conductive film are sequentially laminated on the other surface of the transparent substrate. It can also be set as the structure which is.

Moreover, the present invention is a touch panel in which a pair of substrates with a transparent conductive film are arranged at a predetermined interval in a state where the transparent conductive films face each other, and as at least one of the substrates with a transparent conductive film, It was set as the structure using the film for touchscreens of any one of above-described this invention.
Moreover, the present invention is a touch panel in which a pair of substrates with a transparent conductive film are arranged at a predetermined interval in a state in which the transparent conductive films face each other, and at least one of the substrates with a transparent conductive film includes: The touch panel film according to any one of the present invention described above, wherein the touch panel film is arranged so that the transparent inorganic oxide layer is oriented on the touch side surface.

In the touch panel film of the present invention having the above-described configuration, the ultraviolet curable resin layer (HC layer) formed on the transparent substrate has a predetermined inorganic content on the surface facing the transparent inorganic oxide layer (MS film) and in the vicinity thereof. A region rich in oxide components is provided.
Thus, in the present invention, in the region near the surface where the ultraviolet curable resin layer (HC layer) is in contact with the transparent inorganic oxide layer (MS film), a large amount of inorganic oxide is present in the ultraviolet curable resin layer (HC layer). It becomes a structure and it is aimed so that a mutual component may be similar, and both affinity is improved significantly. Therefore, the ultraviolet curable resin layer (HC layer) is dramatically improved in the adhesion of the transparent inorganic oxide layer (MS film) as compared with the conventional case, and does not easily peel off.

  In order to exert the effect, the inorganic oxide in the HC layer has a ratio of the inorganic oxide to the organic component (the ratio B / A) in a region 10 nm deep from the surface of the HC layer in contact with the transparent inorganic oxide film layer. It must be in the range of 0.05 to 0.35, preferably 0.1 to 0.3. Further, the ratio B / A is maintained even in a region deeper than 10 nm, or the ratio is continuously decreased from the composition.

Here, when the ratio B / A is less than 0.1, the light resistance, which is the main effect of the present invention, cannot be obtained. Moreover, since 0.35 has too much inorganic oxide on the surface of HC, it becomes easy to generate | occur | produce a crack on the surface.
As a method for adjusting the ratio B / A of the inorganic oxide to the organic component in a region 10 nm deep from the surface of the HC layer to 0.05 or more and 0.35 or less, for example, (1) Si described in Patent Document 1 (2) Method of contacting a surface with a silane coupling agent in a gas phase (surface modification with a silane coupling agent), (3) Silicone component (ultraviolet light) It is also possible to use a method of mixing them with or without heat reactivity. However, in the methods exemplified in (1) to (3), the effect of the present invention cannot be obtained at all, and the light resistance may be lowered.

The reason why the effect of the present invention is obtained is that, in the present invention, the inorganic oxide dispersed in the HC layer and the UV curable resin forming the HC layer are physically bonded by the so-called anchoring effect or the like. For this reason, this point is decisively different from (1) to (3) exemplified.
In the present invention, the inorganic oxide on the surface of the HC layer in the vicinity of the surface in contact with the MS film is originally rich and is not easily affected by the photo-oxidative degradation of the organic polymer. Even if the deterioration occurs, it is considered that the MS film is hardly peeled off due to the anchor action.

  Therefore, in the touch panel film of the present invention, oxygen is diffused and penetrated into the film during use or storage of the touch panel film, and the film is relatively high energy on the short wavelength side of ultraviolet rays or visible light from the outside. Even if the light is continuously received, it is stable by preventing the peeling between the UV curable resin layer (HC layer) and the transparent inorganic oxide layer (MS film) and exhibiting excellent light resistance for a long period of time. It is possible to maintain the form.

  As a result, a highly reliable touch panel having high input durability over a long period can be expected.

2 is a schematic cross-sectional view showing a configuration of a film for a touch panel according to Embodiment 1. FIG. 6 is a schematic cross-sectional view showing a configuration of a film for a touch panel according to Embodiment 2. FIG. 6 is a schematic cross-sectional view showing a configuration of a film for a touch panel according to Embodiment 3. FIG. FIG. 6 is a schematic cross-sectional view illustrating a configuration of a touch panel film according to a fourth embodiment. FIG. 10 is a schematic cross-sectional view showing a configuration of a film for a touch panel according to Embodiment 5. It is typical sectional drawing which shows the structure of the film for touchscreens of Embodiment 6. FIG. FIG. 20 is a perspective view showing a configuration of an LCD with a resistive touch panel according to a seventh embodiment. FIG. 10 is a cross-sectional view showing a configuration of an LCD with a resistive touch panel according to a seventh embodiment. 10 is a graph showing a reflection spectrum of Example 3. 10 is a graph showing a reflection spectrum of Example 4.

Embodiments of the present invention will be described below, but the present invention is naturally not limited to these embodiments, and can be appropriately modified and implemented without departing from the technical idea of the present invention. .
<Embodiment 1>
(Configuration of film with transparent conductive film)
FIG. 1 is a cross-sectional view showing a laminated structure of touch panel film 1 according to the first embodiment.

Touch panel film 1 (hereinafter simply referred to as “film 1”) is an MS film 3 including a middle refractive layer 42, a low refractive layer 43, and a transparent conductive film 13 on one main surface of the transparent planar member 4. Formed and configured.
In the resistive touch panel, the film 1 is used by arranging a pair (two sheets) so that the transparent conductive films 13 face each other as described in the seventh embodiment (described later). (See films 1a and 1b and transparent conductive films 13a and 13b in FIG. 8). In FIG. 1, as indicated by arrows, the upper part of the drawing is illustrated as the facing side, and the lower part of the drawing is illustrated as the input side (touch side surface).

The transparent planar member 4 is configured by forming HC (hard coat layers) 41 and 44 which are ultraviolet curable resin layers on both surfaces of a base film 40.
The base film 40 is a transparent substrate made of a resin film having excellent touch panel characteristics such as transparency and flexibility and keystroke durability. Although the material is not limited, examples of the material satisfying the above characteristics include polyethylene terephthalate (PET), polycarbonate (PC), cyclic polyolefin resins such as norbornene, polyether sulfone (PES), and the like. Examples of commercially available products include “Cosmo Shine A4300” manufactured by Toyobo Co., Ltd., “Arton” series manufactured by JSR, and “Zeonor” series manufactured by Nippon Zeon.

  The HC layers 41 and 44 are provided for the purpose of protecting the base film 40 and providing the film 1 with a predetermined hardness, transparency, and the like. The thickness is preferably in the range of 1 μm to 10 μm. As a material, an organic component such as an ultraviolet curable acrylic resin or a urethane resin is a main component, and an inorganic oxide (an oxide containing at least one element of Si, Zr, Sn, and Sb) is included therein. Among these, at least the HC layer 41 is a main characteristic part of the present invention, and the ratio of the inorganic oxide in the surface in contact with the MS film 3 and its neighboring region is higher to a predetermined value than in other regions. Is set. The “neighboring region” here refers to a region at least 10 nm in depth from the surface. However, the ratio of the inorganic oxide over a deeper region may be higher than that in other regions.

  Specifically, in the HC layer 41, the number B of inorganic elements in the inorganic oxide (here, Si component) with respect to the number A of organic elements in the organic component (here, carbon component) in the surface in contact with the MS film 3 and in the vicinity thereof. , Zr, Sn, Sb) ratio B / A (ie, (Si + Zr + Sn + Sb) / C) is adjusted to be 0.05 to 0.35, preferably 0.1 to 0.3. ing.

Such HC layers 41 and 44 can be configured using a method as disclosed in Patent Document 5, for example. Patent Document 5 includes (a) a condensate of an organosilicon compound represented by R _n SiX _4-n as a main component, and (b) a metal chelate compound, a metal organic acid salt compound, two or more hydroxyl groups, or a hydrolyzable group. A photo-sensitive compound sensitive to light having a wavelength of 350 nm or less and / or a compound derived therefrom, selected from the group consisting of metal compounds having the following: hydrolysates thereof, and condensates thereof; c) An organic-inorganic composite containing an ultraviolet curable compound. Such an organic-inorganic composite is prepared by applying a paint containing the raw materials (a), (b) and (c) to the surface of the base film 40, volatilizing and removing the solvent, and then polymerizing the surface with ultraviolet rays. Can be configured. The surface of the HC layer obtained in this way is rich in inorganic oxide (siloxane) component. Further, the HC layer has a gradient composition from the surface toward the depth direction.

Moreover, the method etc. which are described as an Example of patent document 6 can also be utilized. Patent Document 6 is composed of a binder component, and conductive powder and high refractive index powder dispersed in the binder component. The conductive powder is 0.1 to 30% by mass of tin hydroxide powder and 70 to 70%. The present invention relates to a composition for forming a transparent conductive film comprising 99.9% by mass of other conductive powder, a transparent conductive film formed from such a composition, and the like. In order to carry out the present invention, it is not particularly necessary to use an insulating powder such as SiO ₂ or ZrO ₂ instead of a conductive powder. As a method for carrying out the present invention, the description in Patent Document 6 can be referred to.

By these methods, since the region 410 rich in inorganic oxide component is formed on the surface of the HC layer 41, compared with the conventional HC layer not having such a region 410 rich in inorganic oxide component, the HC layer The compatibility with the MS film 3 laminated on 41 is improved, and excellent adhesion is exhibited.
That is, when a conventional film for a touch panel receives light in a low wavelength region of ultraviolet to visible light having a wavelength of about 300 nm or more and about 550 nm or less at a high illuminance for a long time, the HC layer and the transparent inorganic oxide layer (the present invention In this case, it has been confirmed that peeling is likely to occur between the transparent planar member 4 and the MS film 3). Furthermore, the inventors of the present application have made extensive studies and found that the ease of peeling depends on the total thickness of the MS film. That is, as the touch panel film is used, the organic polymer of the HC layer facing the MS film is low molecular weight when irradiated with light of the above wavelength in the presence of oxygen or moisture diffused and penetrated into the film. (Deteriorates). Then, due to the stress inherent in the interface between the MS film and the HC layer, peeling occurs at the location where the HC deteriorates. The reason for this is considered to be that the MS film is more easily peeled off because its stress increases as its thickness increases. The inventors of the present application do not peel off at the strict interface between the transparent inorganic oxide layer and the HC layer, but peel off at a place entering the inside of the HC by about several nm from the surface layer of the HC. I found out.

  In order to solve such a problem, the film 1 is provided with a region 410 rich in a predetermined inorganic oxide component on the surface of the HC layer 41, so that oxidation or hydrolysis near the surface is higher than that of the HC layer made of only an organic polymer. The adhesion between the MS film 3 and the HC layer 41 is improved as compared with the prior art, and separation of both is effectively prevented. For this reason, even if the film 1 is used over a long period of time, the touch panel function is maintained by stable adhesion.

Such an effect of the present invention is particularly useful in that a stable operation of the touch panel can be maintained by preventing peeling of each layer in a use environment where light having a wavelength of about 300 nm to 550 nm is continuously irradiated. It is expensive.
In addition to the first embodiment, the configuration of the HC layer rich in inorganic oxide components is applied only to at least the HC layer 41 on which the MS film 3 is laminated in common with each of the following embodiments. In addition to this, it may be applied to the HC layer 44 as shown in FIG. A region 440 rich in inorganic oxide components is formed on the surface of the HC layer 44 (the lower surface in FIG. 1).

Further, the HC layer only needs to be formed on at least one main surface of the base film 40, but it is desirable to provide the HC layer on both surfaces in order to obtain mechanical strength and the like. By providing the HC layer 44 also on the lower surface side of the base film 40, the operability (writing property) of the user's finger or stylus pen as an input means, antifouling property, fingerprint resistance, antifouling property and surface resistance Abrasion and the like are imparted.
Further, at least one of the HC layers 41 and 44 may be subjected to a known surface treatment such as embossing.

The regions 410 and 440 rich in the inorganic oxide component can be confirmed and quantitatively analyzed by X-ray Photoelectron Spectroscopy (XPS). The depth profile of the HC layer can also be measured by using sputter etching with Ar ions at the time of XPS measurement.
The MS film 3 is configured as a transparent inorganic oxide layer in which the middle refractive layer 42, the low refractive layer 43, and the transparent conductive film 13 are laminated in order from the transparent planar member 4 side. Any of these can be formed using any of various thin film forming methods (for example, sputtering method, electron beam method, ion beam method, vacuum deposition method, plasma CVD method, Cat-CVD method, MBE method, etc.). The sputtering method is suitably used for such applications that require uniformity in thickness and surface resistance. By carrying out these film formations, the total thickness of the MS film 3 is set to 30 nm or more and 300 nm or less, here 120 nm. Each layer that is a constituent element of the MS film 3 has predetermined transparency and refractive index, and is disposed to impart optical characteristics to the film 1 such as prevention of reflection of external light.

Middle refractive layer 42 is a first layer of transparent inorganic material having a thickness of about 60 nm, if illustrated SiON or _SiO 2 -SnO ₂ based, _or may be a film of SiO 2 -TiO ₂ system.
The refractive index of the middle refractive layer 42 is set to about 1.6 to 1.9 (wavelength 630 nm), which is higher than the refractive index of the low refractive layer 43 described later.

The low refraction layer 43 is a second refraction layer in the MS film 3 and is a second layer containing an inorganic component whose main component is silicon oxide (SiO ₂ ). The layer thickness is set to 15 nm to 60 nm and the refractive index is set to about 1.46 (wavelength 630 nm).
Thus, the middle refractive layer 42 and the low refractive layer 43 are configured as layers having different refractive indexes, and by using these, good optical properties (transparency) are imparted to the film 1.

The middle refractive layer 42 and the low refractive layer 43 may be repeatedly laminated, but if the number of laminated layers is increased too much, the film 1 may be warped or a crack may be generated in the MS film 3. It is necessary to keep in mind.
The transparent conductive film 13 is made of ITO having a known resistance value (surface resistance), antimony-added tin oxide, fluorine-added tin oxide, aluminum-added zinc oxide, potassium-added zinc oxide, silicon-added zinc oxide, potassium-added zinc oxide, zinc oxide. -Using any one or more materials such as tin oxide, indium oxide-tin oxide, indium oxide-tungsten oxide, indium oxide-titanium oxide, or other metal materials, CVD, vacuum deposition, It is formed by forming a film by a method such as sputtering or ion beam. Here, it is configured as a resistance film (transparent electrode film) using only ITO. As an example of setting for film formation, the surface resistance is 200 to 1 kΩ / sq. The thickness is 20 nm or more and 40 nm or less, and the refractive index is about 1.9-2.

  Here, in general, in a film for a touch panel, oxygen or water vapor diffuses and penetrates into the film as it is used. When the oxygen is invaded and the use is continued for a long time in the presence of light, the resin molecules in the HC layer are reduced in molecular weight due to photo-oxidation degradation. When the film is continuously irradiated with light having a wavelength of 300 nm or more and 550 nm or less, the frequency of occurrence of this oxidation reaction is increased. According to the study by the inventors, it is considered that such a process reduces the adhesion between the MS film and the HC layer.

  On the other hand, in the film 1 of the present invention, as described above, the affinity between the MS film 3 and the HC layer 41 is improved by providing the surface 410 of the HC layer 41 and the region 410 rich in the inorganic oxide component in the vicinity thereof. As a result, the close contact with each other has been dramatically improved. Therefore, even if the organic component of the HC layer 41 in the vicinity of the interface continuously receives light irradiation with the constant wavelength from the outside in a state where oxygen diffuses and penetrates into the film 1, the MS film 3 remains in the HC layer. It does not peel easily from the surface of 41.

By providing such excellent light resistance, the film 1 exhibits stable adhesion.
Therefore, according to the film 1 of the present invention, by improving the adhesion between the MS film 3 and the HC layer 41, light having a relatively high illuminance such as ultraviolet rays having a short wavelength caused by a mercury lamp or a xenon lamp in the atmosphere. Even under the usage environment where irradiation is performed, stable adhesion is exhibited over a long period of time, and a touch panel having excellent light resistance can be realized, which is very useful.

Hereinafter, embodiments of the film for a touch panel other than those described above will be described focusing on differences from the first embodiment.
<Embodiment 2>
FIG. 2 is a partial cross-sectional view showing the configuration of the touch panel film 1A of the second embodiment.

The feature of the film 1A shown in this figure is that the middle refractive layer 42 is omitted and the low refractive layer 43 is formed directly on the HC layer 41. In this example, the MS film 3 includes only the low refractive layer 43 and the transparent conductive film 13. The thickness of the MS film 3 is set to about 35 nm to 90 nm.
Also in the film 1A of the second embodiment, the affinity between the HC layer 41 and the MS film 3 (particularly the low refractive layer 43) is provided in the same manner as the film 1 by disposing the region 410 rich in inorganic oxide components. Is improved, and the adhesion between the two is improved.

  That is, even when the manufactured film 1A is stored in the atmosphere and continuously irradiated with light having a wavelength of about 300 nm to 550 nm, the HC layer is formed in the vicinity of the interface between the HC layer 41 and the middle refractive layer 42. It is possible to suppress the degradation reaction 41 (reaction in which the organic component has a low molecular weight). In addition, even during use of the touch panel, sufficient input durability is exhibited, and peeling of components can be prevented and stable touch panel characteristics can be maintained over a long period of time.

<Embodiment 3>
FIG. 3 is a partial cross-sectional view showing the configuration of the touch panel film 1B of the third embodiment.
The characteristic of the film 1B shown in this figure is that the transparent conductive film 13 is formed directly on the HC layer 41 without using the middle refractive layer and the low refractive layer.

Also in the film 1B having such a configuration, good light resistance and touch panel characteristics are exhibited as in the first and second embodiments.
In addition, the third embodiment has a particularly good peeling prevention effect when the transparent conductive film 13 is relatively thick. In general, the thickness of the transparent conductive film 13 of the resistive touch panel is about 15 nm to 40 nm. However, when the thickness is 40 nm or more, the stress of the film 13 itself is increased, so that the followability with the transparent planar member 4 is reduced. To do. For this reason, it becomes easy to produce the adhesive fall between HC layer and a transparent conductive film.

  However, in the present invention, the adhesion between the HC layer 41 and the transparent conductive film 13 is improved. Therefore, even if the thickness of the transparent conductive film 13 is 30 nm or more, the film 13 is the HC layer 41. Does not peel easily from the side. For this reason, even in the configuration in which the transparent conductive film 13 is directly formed on the HC layer 41, stable adhesion is exhibited over a long period of time, and a touch panel with excellent durability is realized.

<Embodiment 4>
FIG. 4 is a partial cross-sectional view showing the configuration of the touch panel film 1 </ b> C of the fourth embodiment.
The film 1C shown in this figure has the same laminated structure of the MS film 3 and the transparent planar member 4 as that of the film 1 of the first embodiment. However, in the transparent planar member 4, the HC layers 41A and 42A have a predetermined structure. The nano-particles 50 are dispersed.

The nanoparticles 50 are made of inorganic pigments (one or more of SiO ₂ , ZrO ₂ and antimony tin oxide (ATO)), and are composed of inorganic fine particles having an average primary particle size (5 to 40 nm).
The addition concentration of the nanoparticles 50 is adjusted so that the concentration in the HC layers 41A and 44A is 20% by weight to 90% by weight in the coating film after drying (not including the organic solvent). Has been. Even in the HC layer set in this way, the number of inorganic elements B in the inorganic oxide component (here, the number of elements of Si, Zr, Sn, and Sb with respect to the number A of organic elements of the organic component on the HC surface and its vicinity) (Sum) ratio B / A (that is, (Si + Zr + Sn + Sb) / C) can be 0.05 or more and 0.35 or less.

Also in the film 1C having the HC layers 41A and 44A using such nanoparticles 50, as in the first embodiment, oxygen penetrates into the film 1C and is irradiated with visible light having a wavelength of 350 nm or more and 550 nm or less. In the environment, excellent light durability is exhibited mainly between the MS film 3 and the HC layer 41A, and good touch panel characteristics can be obtained.
In the fourth embodiment, in each of the HC layers 41A and 44A, the configuration in which the nanoparticles 50 are dispersed throughout each layer is exemplified. However, as in the HC layer 41 of the first embodiment, for example, the MS film Alternatively, the nanoparticles 50 may be unevenly distributed in the vicinity of the surface in direct contact with 3. As a manufacturing method in this case, a plurality of paints (usually including an organic solvent) as materials of the HC layer are prepared and applied stepwise to the surface of the base film 40, and the nanoparticles 50 are formed as the uppermost surface portion. An example is application and drying of a paint in which is dispersed. Even with such a configuration, it is considered that the adhesion between the HC layer 41A and the MS film 3 can be improved.

<Embodiment 5>
FIG. 5 is a partial cross-sectional view showing the configuration of the touch panel film 1D of the fifth embodiment. In this figure, the upper surface of the paper is the input surface side (touch side) surface, and the lower surface is the opposite surface side (display side) surface.
The film 1D shown in this figure is the same as the film 1B of Embodiment 3 in which the HC layers 41 and 44 are formed on both surfaces of the base film 40, and the transparent conductive film 13 is laminated on the surface of the HC layer 41 on the opposite surface side. Basic structure. A configuration in which the middle refractive layer 42a, the low refractive layer 43a, the middle refractive layer 42b, and the low refractive layer 43b are sequentially laminated on the HC layer 44 on the input surface side, and the lubricant layer 45 is disposed as the uppermost layer. Have The middle refractive layers 42a and 42b and the low refractive layers 43a and 43b have the same composition. The film thickness of the MS film 3 is set to about 220 nm. As described above, by alternately laminating the middle refractive layer and the low refractive layer, the film 1D is provided with good antireflection (AR) characteristics.

The lubricant layer 45 is a layer provided in order to improve the writing input characteristic with the pen of a touch panel by providing the film 1 with lubricity. Further, by providing the lubricant layer 45, it is possible to reduce the external force generated in the MS film 3 due to the frictional force generated along with the input. Here, a known fluorosilane-based fluorine antifouling agent (for example, “OPTOOL ^TM DSX” manufactured by Daikin Industries, Ltd.) is used.

The thickness of the lubricant layer 45 is very thin and can be about 1 nm.
In the fifth embodiment, the MS film 3 is configured by a multilayer structure in which layers formed of two or more different materials are stacked. However, the stacking order of the layers may be any. . In the example of FIG. 5, the low refractive layer 43a (or 43b) is first laminated on the HC layer 44, and the middle refractive layer 42a (or 42b) is laminated on the low refractive layer 43a (or 43b). Good.

In addition, the set of lamination units of the low refractive layer and the middle refractive layer may be laminated by repeating two or more. The middle refractive layer can be composed of an inorganic oxide layer containing one or more of TiO ₂ , Ta ₂ O ₅ and Nb ₂ O ₅ . Of these, the refractive index of the layer using Nb ₂ O ₅ alone can be adjusted to 2.3.
Further, the low refractive layer can be composed of an inorganic oxide layer containing at least one of SiO ₂ and SnO ₂ . The refractive index of the layer using SiO ₂ alone can be adjusted to 1.46, and the refractive index of the layer formed of SiO ₂ and SnO ₂ can be adjusted to 1.9.

  The film thicknesses of these low-refractive layer and medium-refractive layer can be arbitrarily adjusted, and can be adjusted, for example, in the range of about 10 nm to about 120 nm. As described above, by using one or more stacked units of the low refractive index layer and the middle refractive layer, reflection of visible light (for example, visible light having a wavelength near 550 nm) that is easy for humans to detect, as shown in a performance confirmation experiment described later. The rate can be effectively reduced, and a good effect can be expected in combination with the light resistance of the HC layer 44. However, if it is too thick, the visible light transmittance is lowered, and if it is too thin, it is difficult to obtain sufficient strength and reflectance.

Further, the present invention is not limited to this configuration, and the stacking order can be reversed. Alternatively, the middle refractive layer 45 and the low refractive layer 46 may be laminated in multiple stages. By adjusting the layer structure as described above, an MS film that matches the AR characteristics required for the touch panel can be obtained.
<Embodiment 6>
FIG. 6 is a partial cross-sectional view showing the configuration of the touch panel film 1E of the sixth embodiment. In this figure, the upper surface of the paper is the input surface side (touch side) surface, and the lower surface is the opposite surface side (display side) surface.

The film 1E shown in this figure has the basic structure of the film 1B of the third embodiment. The middle refractive layer 42a and the low refractive layer 43a are sequentially laminated on the HC layer 44 on the input surface side, and the uppermost layer thereof. The low-density siloxane layer 46 is formed.
Here, the low-density siloxane layer 46 is a layer formed by applying and drying a predetermined material based on a sol-gel method, and has a large number of fine spaces (bubbles of several to several tens of nm) inside. This is a layer in which a methyl group, an ethyl group or a fluorine group is present. Thus becomes lower refractive index than the refractive index 1.46 of the bulk SiO ₂ (density of 2.22g / cm ^3), it is possible to impart good AR properties to the film 1E.

Examples of the chemical structure of the layer 46 include a configuration in which, for example, a siloxane bond skeleton is mainly used, and an appropriate amount of a fluorosilane compound, a methyl group, an ethyl group, or the like is introduced. In this configuration, since the introduced fluorosilane compound or methyl group is bonded to the Si atom, the density of the network structure mainly composed of SiO ₂ can be reduced, and the low-density siloxane layer 46 having a sufficiently low refractive index. Can be formed.

Also in such a film 1E, as in the first embodiment, good adhesion is exhibited between the HC layer 44 and the MS film 3, and it is effectively prevented from causing peeling. In addition, by using the low density siloxane layer 46, a touch panel with good transparency can be realized.
<Embodiment 7>
FIG. 7 is an assembly diagram showing a configuration example of a resistive film type touch panel 2 (hereinafter simply referred to as “touch panel 2”) according to the seventh embodiment and an LCD combined therewith. FIG. 8 is a cross-sectional view of the touch panel 2.

  As shown in FIGS. 7 and 8, the touch panel 2 is formed by laminating an antireflection (AR) film 11, a film 1a, a spacer 15, a wiring board 30, a rib spacer 17, a film 1b and the like in order from the top. An LCD 201 is laminated on the lower surface of the film 1b in the same order via a plurality of intermediate layers 20 including an adhesive layer and the like, and an LCD-integrated touch panel is formed as a whole. Among these structures, the film 1 for touch panels of Embodiment 1 is used for film 1a, 1b.

Of course, the display combined with the touch panel 2 is not limited to the LCD, but may be other types of displays such as CRT, organic EL, PDP, and electronic paper.
The touch panel 2 employs a so-called “4-wire type” input detection method.
The AR film 11 is obtained by sequentially forming a hard coat layer and an antireflection layer from the base film on the input surface (touch surface) side using triacetyl cellulose (TAC) or PET as a base film. Usually, the AR film 11 and the film 1a are used by being bonded to each other through an adhesive layer (not shown).

The films 1a and 1b are arranged in a pair so that the transparent conductive films 13a and 13b formed on each side face each other at a predetermined interval. A carrier having a desired surface roughness is pressure-bonded to at least one opposing surface side of each film 1a, 1b (embossing molding), or SiO ₂ or the like is formed in the HC paint before the HC layer 41 is formed. It is also preferable to subject the surface to fine unevenness using a method of dispersing fine particles (average particle diameter of several μm) as appropriate. Thereby, generation | occurrence | production of the Newton ring in film 1a, 1b can be suppressed effectively, and visibility can be improved. In addition, what is necessary is just to implement the said Newton ring prevention process suitably as needed.

  Here, the transparent conductive films 13a and 13b are formed in a predetermined stripe pattern on the surface of the low refractive layer 43. The overall pattern of the transparent conductive films 13a and 13b is formed in a rectangular shape in the example shown in FIG. 7, but is not limited to this. Further, lead lines 131, 132, 141, 142 are arranged along a pair of sides parallel to the y-axis or x-axis of the transparent conductive films 13a, 13b, respectively, so as to form xy orthogonal coordinates as a whole. Has been. The lead wires 131, 132, 141, 142 are provided with electrode terminals 131a, 132a, 141a, 142a. In FIG. 7, reference numeral 133 denotes a connection line between the electrode terminal 132 a and the lead wire 132.

Around the transparent conductive films 13a and 13b, a rib spacer 17 having a height of about 50 μm, which is formed of any one of an adhesive material, an adhesive sheet, and a double-faced tape having an adhesive material layer on both sides of a plastic film, is disposed. Thereby, normally, the transparent conductive films 13a and 13b are arranged to face each other at a constant interval 16.
Further, on the surface of the transparent conductive film 13b, hemispherical projection spacers 15 are arranged at regular intervals in a matrix along the xy direction, and unnecessary contact between the transparent conductive films 13a and 13b is avoided. . The protrusion spacer 15 is made of a transparent photocurable acrylic resin, and is set to have a size of, for example, a height of 10 μm and a diameter of 10 μm to 50 μm according to the facing distance of the films 1a and 1b. In FIG. 7, for the convenience of illustration, the size of the protrusion spacer 15 is schematically shown larger than the actual size. The protrusion spacer 15 may have a shape other than a hemispherical shape, such as a conical shape or a cylindrical shape.

  A flexible connector 30 is interposed between the transparent conductive films 13a and 13b in accordance with the positions of the electrode terminals 131a, 132a, 141a, and 142a on the films 1a and 1b. In the flexible connector 30, wirings 302 to 305 made of a material having good conductivity such as Au, Ag, and Cu are formed on the surface of the flexible substrate 301 made of a resin material such as PET or polyimide. Become. Electrode terminals 302a to 305a are formed on the wirings 302 to 305, and are connected to the electrode terminals 131a, 132a, 141a, and 142a.

The input detection principle (4-wire type) of the touch panel 2 applies a DC voltage of about 0 to 5 V between the lead lines 131 and 132 along the y axis during driving. When an input is made by the user, position data in the y-axis direction is acquired using the lead lines 141 and 142 along the x-axis as voltage detection electrodes.
Next, a voltage is applied between the lead lines 141 and 142 along the x axis, and position data in the x axis direction is acquired using the lead lines 131 and 132 along the y axis as voltage detection electrodes. Thus, coordinate information for both xy is obtained. In the touch panel 2, by repeating this detection step alternately, input information from the user is sequentially acquired, and a GUI (Graphical User Interface) is realized.

  Here, the main feature of the touch panel 2 of the seventh embodiment is that the film 1 for touch panel of the first embodiment is used for the films 1a and b having the transparent conductive films 13a and 13b on one side, respectively. As described in the first embodiment, the films 1a and 1b are provided with the region 410 rich in a predetermined inorganic oxide component in the HC layer 41, so that the adhesion mainly with the MS film 3 is improved. Yes. For this reason, the touch panel 2 is laminated so that the components maintain strong adhesion, and can exhibit excellent input durability over a long period of time.

Therefore, by obtaining such an effect, the touch panel 2 is used in the field where the ultraviolet irradiation amount is relatively large, or used in a car navigation system that is likely to be in a high temperature environment, and light with a wavelength of 300 nm to 550 nm is emitted. Even when continuously used in an environment where irradiation is continuously performed, stable input characteristics can be maintained over a long period of time.
In addition, the structure of the touch panel of this invention is not limited to the structure of FIG.7 and FIG.8, For example, it is good also as what is called FG type which comprises the base film in the film 1b with a glass substrate.

  Moreover, although the example which utilizes the film 1 of Embodiment 1 as the film 1a, 1b was shown in the touch panel 2, it is naturally not limited to this in the film 1a, 1b, Other than this of Embodiment 2-6 Any of the films 1A to 1E can be applied. In this case, the film of another embodiment can be applied to one film and the other film, respectively.

  When any one of the films 1 and 1A to 1C exemplified in the first to fourth embodiments is applied, the MS films 3 of the respective films illustrated in FIGS. (Surface side). On the other hand, when any one of the films 1D and 1E exemplified in the fifth and sixth embodiments is applied, the MS film 3 of each film shown in FIGS. 5 and 6 is the input surface side (touch side surface) of the touch panel or the LCD 201. Note that it is oriented sideways.

Moreover, in the structure of the said FG type, instead of a glass substrate, the laminated body (FFG type) which adheres the film material of the said planar member to a glass plate or a resin board suitably with an adhesive material. Or F-FP type) may be provided. Further, the number of laminated films and the glass substrate, the order of lamination, and the like can be appropriately changed and adjusted.
Furthermore, the input method of the touch panel to which the present invention is applied may be any method, for example, a capacitance type.

<Film production method>
Here, the manufacturing method of the film 1 for touch panels of Embodiment 1 is mainly illustrated.
In the following, steps 1 and 2 exemplify the case where HC layers having the same structure are formed on both main surfaces of the base film.
In addition, although the formation method of each layer is illustrated, since the lamination order of each component changes depending on embodiment, it should be noted that the film formation order should be set according to each.

1. A PET film (“Cosmo Shine A4300” manufactured by Toyobo Co., Ltd.) having a thickness of 188 μm and a width of 300 mm is prepared as the base film 40.
2. Production of HC layer (production of HC layer of Embodiments 1 to 3, 5, and 6 (HC layer having an inorganic oxide component-rich region based on the description in Patent Document 5))
First, according to the Example of patent document 5, the ultraviolet curable coating material which contains a polysiloxane bond in a large quantity in a film | membrane is obtained.

The adjusted paint is applied to one main surface of the base film 40 based on, for example, a roll coating method. Thereafter, the coating film is dried to remove excess solvent. When the solvent is removed, the composition in the so-called paint is separated, and the ratio of the number of elements between the inorganic oxide (polysiloxane) component and the organic component in the vicinity of the coating film surface of the paint (the ratio B / A described above) is , And adjusted so as to be larger than other areas of the coating film. After the solvent is volatilized and removed, the coating material is UV-cured by irradiating with ultraviolet rays using a high pressure mercury lamp or the like to polymerize the resin material. Thereby, the HC layer 41 having a final thickness (about 1 μm or more and about 10 μm or less) is formed. A similar layer is also formed on the other main surface of the base film 40 to form the HC layer 44. Finally, the SiO ₂ in the polysiloxane has an Si / C element number ratio Si / C of 0.05 to 0.35 in a region within a depth of 10 nm from the surface in the finally formed HC layer. Adjust to be within the range.

The element ratio in the region within 10 nm depth from the surface can be constant, but is set so that the element ratio is gradually decreased from the surface in the depth direction so as to have a so-called gradient composition. May be. In this case, in addition to performing the method described in Patent Document 5 described above, there may be mentioned a method in which paints having different polysiloxane contents are divided into several stages and applied in layers.
(Preparation of HC layer (inorganic oxide nanoparticle dispersed HC layer) of Embodiment 4)
An ultraviolet (UV) curable resin material and a nano-oxide particle material containing at least one element (inorganic component) of Si, Zr, Sn, and Sb are added, MEK, MIBK, isobutyl alcohol (IBA), ethyl alcohol, A paint (volatile solution) is prepared by adding a solvent such as methyl alcohol, normal butyl alcohol (NBA), cyclohexanone (CAN), diacetylacetone (DAA), butyl acetate or isopropyl alcohol (IPA). As these materials, various commercially available products that are uniformly dispersed in a powder or an organic solvent can be used.

  The UV curable resin may be any resin having a vinyl group in the skeleton. For example, trimethylolpropane triacrylate as a trifunctional monomer or its EO-modified, PO-modified product, pentaerythritol tetraacrylate as a 4-functional monomer, hexafunctional Examples of the monomer include dipentaerythritol hexaacrylate. In addition, an oligomer component containing a vinyl group may be appropriately selected and introduced.

As the polymerization initiator, for example, Irgacure 907 (2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one) manufactured by Ciba Specialty Chemicals Co., Ltd. is used.
As the nanoparticle 50, inorganic oxide fine particles made of an inorganic pigment (one or more of SiO ₂ , ZrO ₂ , antimony tin oxide (ATO)) and having a primary particle diameter of about 5 nm to 40 nm are used.

  The added concentration of the nanoparticles 50 is 50% by weight or more and 90% by weight in the HC layers 41A and 44A to be finally formed in a weight% concentration in the coating film after drying (not including an organic solvent). Adjust to be within range. Thus, in the HC layer, the ratio B / A of the number B of inorganic elements in the inorganic oxide to the number A of organic elements in the organic component is set to 0.05 to 0.35 in terms of the number of elements. adjust.

When the ratio B / A of the number B of inorganic elements in the inorganic oxide to the number A of organic elements in the organic component in the layer is higher than 0.35 in terms of the number of elements, the polymerization rate at the time of ultraviolet curing There is a tendency to decrease. This is considered due to the fact that the inorganic oxide component occupies a considerable volume in the ultraviolet curable resin and thus inhibits the radical polymerization reaction.
The polymerization rate can be estimated from the disappearance of the C═C bond after the cured film by infrared absorption spectrum measurement or the like.

For a specific method of forming the HC layer using the fourth embodiment, for example, the description in Patent Document 6 can be referred to.
3. Production of Medium Refractive Layer A film to be deposited is placed inside the sputtering deposition apparatus. Then, the inside of the apparatus is sufficiently decompressed, and a gas such as oxygen or nitrogen is introduced, and sputtering using silicon as a target is performed. As a result, an inorganic layer having a refractive index of 1.74 made of silicon oxonitride (SiON) is formed on the HC layer 41 to form the middle refractive layer 42. The refractive index of SiON can be controlled by the flow rate ratio of oxygen and nitrogen gas during sputtering.

The final film thickness is set to 60 nm (range of 45 nm to 70 nm).
In addition to the above-described composition, the middle refraction layer 42 can be formed of, for example, a SiO ₂ —SnO ₂ -based composition. Further, the film forming method is not limited to a vacuum film forming method such as a sputtering method, and a predetermined material may be used and a film may be formed by wet coating based on a sol-gel method in an air atmosphere. For example, on the outermost surface of the HC layer 41, an organic / inorganic composite material including an inorganic component (for example, titanium oxide sol) containing one or more compounds containing at least one of Si, Ti, Al, and Zr. It is also possible to disperse and form a particulate inorganic filler having a predetermined particle size. As the particulate inorganic filler, at least one of TiO ₂ , SiO ₂ , Al ₂ O ₃ , and ZrO ₂ can be used. The average particle diameter is not specifically limited, For example, about 10 nm-70 nm can be illustrated. The layer thickness can be set to 40 nm or more and 90 nm or less.

Here, for example, the refractive index of ZrO ₂ alone is about 2.2 to 2.4, but decreases to a range of 1.6 to 1.9 by combining with an organic material. Moreover, a preferable light transmission characteristic is realizable by making a film thickness into the said range. Production of Low Refractive Layer A film to be deposited is placed inside the deposition apparatus. After sufficiently reducing the pressure inside the apparatus, oxygen gas is introduced, and sputtering is performed using a Si material as a target. Thereby, a SiO ₂ film having a thickness of 30 nm (range of 15 nm or more and 35 nm or less) is formed on the middle refraction layer 42, and a second refraction layer (low refraction layer) 43 is obtained.

In addition, the film formation method of the low refraction layer 43 is not limited to the thin film formation method similarly to the middle refraction layer 42, and may be formed by other formation methods. For example, it can be formed by a sol-gel method using a solution in which a SiO ₂ component is dispersed. The sol-gel method is one of the coating methods, and the production efficiency is good when forming a film over a relatively large area.
5. Production of Transparent Conductive Film A film to be deposited is placed inside the sputtering deposition apparatus. While reducing the pressure inside the apparatus, Ar and oxygen gas are introduced, and sputtering is performed using a ceramic target or the like in which indium oxide and tin oxide are mixed and sintered in the target. The flow ratio of Ar gas and oxygen gas is appropriately set to a value confirmed in advance so as to obtain predetermined touch panel characteristics (surface resistance and transparency). Further, the discharge power and sputtering time required for sputtering are also adjusted as appropriate. As a result, the final product has a surface resistance of 200 Ω / sq. 1 kΩ / sq. A transparent conductive film 13 (ITO film) having a thickness of 20 nm to 40 nm is obtained below. The crystallinity of the transparent conductive film 13 is, for example, a low SnO ₂ composition of an In ₂ O ₃ —SnO ₂ ceramic target when the film is formed by the sputtering method (the SnO ₂ composition is contained in 3 to 10 wt%). And can be controlled by adjusting the substrate temperature.

As the transparent conductive film material, besides ITO, antimony-added lead oxide, fluorine-added tin oxide, aluminum-added zinc oxide, potassium-added zinc oxide, silicon-added zinc oxide, zinc oxide-tin oxide system, indium oxide-tin oxide, One or more types selected from tin oxide films can be exemplified.
Thereby, the MS film 3 is formed.

The transparent conductive film 13 can also be formed by a coating method in the same manner as the low refractive layer 43 and the middle refractive layer 42. In this case, a thiophene-based conductive polymer material such as PSS / PEDOT or a paint in which a conductive material such as carbon nanotube is dispersed in a binder can be used.
6). Preparation of Lubricant Layer For example, “OPTOOL ^™ DSX” manufactured by Daikin Industries, Ltd. is diluted with perfluorohexane to a concentration of 0.1% by weight. Next, this paint is applied to the surface of the MS film by the gravure method and dried to obtain a fluorine-based lubricant layer having a final thickness of about 1 nm.

7). Preparation of Low Density Siloxane Layer A predetermined volume of a fluorosilane compound or an organic silane material having a methyl group, an ethyl group, or the like is prepared.
These materials are made into a paint based on a sol-gel method, and are applied and dried to form a layer made of low-density siloxane.

  Specifically, organic silane materials such as diethyldiethoxysilane, ethyltriethoxysilane, and tetraethoxysilane partially hydrolyzed and dehydrated, and alcohol organic solvents such as IPA and IBA, water, A paint containing hydrochloric acid is used as a paint. A low-density siloxane layer can be obtained by applying this paint to a desired thickness by a gravure coating method, a spin coating method, a dip coating method, or the like.

The touch panel film of the present invention is completed by the above procedure.
<Performance confirmation experiment>
Next, in order to confirm the performance of the present invention, examples will be described, and the results of various experiments will be described.
(HC layer of Embodiments 1-3, 5-6 (Performance confirmation experiment of HC layer having inorganic oxide component rich region according to Patent Document 5)
A confirmation test was performed on the adhesion between the HC layer and the MS film in the case of using the HC layer shown in the first to third embodiments.

As a sample of the example, a configuration similar to that of Embodiment 1 was produced based on the above-described film manufacturing method.
As a sample for the comparative example, an HC film containing no siloxane component was prepared.
The specific creation procedure is as follows.
(Preparation of paint)
8 parts by weight of epoxy acrylate, 22 parts by weight of dipentaerythritol hexaacrylate, 1.5 parts by weight of photopolymerization initiator (Irgacure 184 manufactured by Ciba Specialty Chemicals Co., Ltd.), 70 parts by weight of MEK and cyclohexanone 50:50 mixed solvent The paint prepared in step 1 was prepared.
(HC film formation)
The paint was applied and formed on a base film (PET film, Toyobo Cosmo Shine A4300-188 μm thickness) with a Meyer bar (# 10), and then the organic solvent was volatilized at 80 ° C. Next, an HC film of about 5 μm was obtained by irradiating ultraviolet rays using a high-pressure mercury lamp in a nitrogen purge atmosphere.

In both the examples and the comparative examples, a plurality of samples in which the thickness of the HC layer was changed were produced.
As a test method, first, a total of 100 squares were half-cut with a cutter on the 1 mm square surface of the MS film formed on the sample touch panel film. Next, using an ultraviolet fade meter (carbon arc) manufactured by Suga Test Instruments Co., Ltd., a sample having a predetermined wavelength is continuously applied to each sample from the surface opposite to the surface on which the half-cut MS film is formed. Irradiated with ultraviolet rays. During this ultraviolet irradiation, a sample was taken out from the testing machine every 48 hours, and a cellophane tape manufactured by Nichiban Co., Ltd. was attached to the surface of the MS film to perform a peeling test of the MS film. The occurrence of peeling at this time was confirmed visually.

In addition, although verification of this effect was implemented to 1200 hr at the maximum, it was not implemented any more.
The test results are shown in Table 1.

表１に示す結果から、実施例のサンプルは比較例のサンプルに比べ、長時間にわたる紫外線照射を受けても剥離の発生が抑制され、良好な耐光耐久性を有していることが確認できた。特に、実施例のサンプルは、ＨＣ層の厚みを増加させても剥離の発生が効果的に防止できる点は高く評価できる。すなわち、本発明はＨＣ層の厚みにそれほど依存することなく、ＭＳ膜とＨＣ層間の剥離を防止する効果が認められるため、設計上の制約が小さく、実際に本発明を実現する上で極めて有用性が高いと考えられる。
（実施の形態４のＨＣ層（無機酸化物ナノ粒子分散型ＨＣ層）の性能確認実験）
実施の形態４に示したナノ粒子を用いた場合における、ＨＣ層とＭＳ膜との密着性について確認試験を行った。実施例と比較例の各サンプルは以下のものを用意した。

From the results shown in Table 1, it was confirmed that the sample of the example was suppressed in the occurrence of peeling even when subjected to ultraviolet irradiation over a long period of time and had good light resistance compared to the sample of the comparative example. . In particular, the sample of the example can be highly evaluated in that the occurrence of peeling can be effectively prevented even when the thickness of the HC layer is increased. That is, the present invention is not very dependent on the thickness of the HC layer, and the effect of preventing the separation between the MS film and the HC layer is recognized. Therefore, the design restrictions are small, and it is extremely useful for actually realizing the present invention. It is considered that the nature is high.
(Performance confirmation experiment of HC layer (inorganic oxide nanoparticle dispersed HC layer) of Embodiment 4)
A confirmation test was performed on the adhesion between the HC layer and the MS film in the case of using the nanoparticles shown in the fourth embodiment. The following samples were prepared for each of the examples and comparative examples.

Example 1;
“A4300-188 μm thickness” manufactured by Toyobo Co., Ltd. was prepared as a PET base film (transparent substrate).
Z7524 manufactured by JSR Corporation was used as a coating material containing 35 to 40% by weight of SiO ₂ nanoparticles in the solvent-dried HC layer. This was coated on the base film, the solvent was removed, and ultraviolet rays were applied to form an HC layer having a thickness of 5 μm.

The element number ratio measurement result by XPS on the HC surface obtained here was Si / C = 0.225.
Example 2;
A paint containing ATO, SnO ₂ , and ZrO ₂ nanoparticles was prepared in the same manner as described in Patent Document 6. This was applied onto the base film, the solvent was removed, and ultraviolet rays were applied to form a 2 μm thick HC layer.

The element number ratio measurement result by XPS on the HC surface obtained here was (Zr + Sn + Sb) /C=0.119.
Comparative Example 1;
In the sample of Example 2, a configuration different only in that the nanoparticles were not added was separately prepared.

In the analysis by XPS of the HC surface obtained here, elements such as Si, Zr, Sn, and Sb could not be confirmed within the measurement range.
Next, ITO (30 nm) / SiO ₂ (60 nm) / SiO ₂ —SnO ₂ (refractive index 1.70, 30 nm) / Si (1 nm) is formed on each HC layer produced in the order from the upper layer to the lower layer. An MS film having a laminated structure was laminated. The ITO film formation temperature was set to 150 ° C., and the film formation temperatures for the other layers were set to 60 ° C.

Thus, the touch panel films of Examples 1 and 2 and Comparative Example 1 were produced.
Subsequently, each of the prepared samples was irradiated with light at a high illuminance with a wavelength of 300 nm or more and 550 nm using a UV fade meter manufactured by Suga Test Instruments Co., Ltd. at room temperature. At this time, the time when peeling occurred was measured. The presence or absence of peeling was confirmed visually.
In addition, although verification of this effect was implemented to 1680 hr at maximum, it was not implemented any more.

  The experimental results are shown in Table 2.

表２に示すように、比較例１では試験開始後２４０時間程度で剥離を発生することが確認された。
これに対し、実施例１、２は、いずれも１２００時間またはそれ以上の剥離寿命を発揮することが確認された。特に実施例２については、１６８０時間経過後も剥離を発生することがなく、安定したタッチパネル用フィルム特性を発揮できることが分かる。

As shown in Table 2, in Comparative Example 1, it was confirmed that peeling occurred about 240 hours after the start of the test.
On the other hand, it was confirmed that both Examples 1 and 2 exhibited a peeling life of 1200 hours or longer. Especially about Example 2, it turns out that peeling does not generate | occur | produce after 1680-hour progress, but the film characteristic for stable touch panels can be exhibited.

The reason why such a result was obtained was that, in Examples 1 and 2, the HC layer was rich in inorganic oxide components due to the compounding of nanoparticles, so the affinity for the MS layer made of inorganic material was increased. It is considered that the adhesion is improved. On the other hand, in Comparative Example 1 in which the HC layer in which such nanoparticles are not dispersed is disposed, the adhesiveness is less than that in Examples 1 and 2 and it seems that peeling occurred early.
(Performance confirmation experiment on antireflection characteristics of multilayer structure of low refractive index layer and middle refractive index layer)
When the film of the present invention is used on a touch panel, it is important to reduce external light reflection on the display surface and improve visibility over a long period of use. Therefore, the antireflection characteristics when the MS film is configured with a low refractive layer and a middle refractive layer having a predetermined composition and film thickness as a multilayer structure were examined.

As Example 3, a film in which a first layer to a fourth layer, which are inorganic oxide layers shown below, were sequentially laminated from the HC layer side was produced. Each of these layers was formed using various ceramic targets by placing a film to be deposited inside a sputtering apparatus, depressurizing the inside of the apparatus, and introducing Ar gas and O ₂ gas. Here, the first layer and the second layer, and the third layer and the fourth layer correspond to the stacked units mentioned in the fifth embodiment, respectively.

The first layer (medium refractive layer) was a niobium oxide (Nb ₂ O ₅ ) layer having a thickness of 13 nm and a refractive index of 2.3.
The second layer (low refractive layer) was a silicon oxide (SiO ₂ ) layer having a thickness of 25 nm and a refractive index of 1.46.
The third layer (medium refractive layer) was a niobium oxide (Nb ₂ O ₅ ) layer having a thickness of 112 nm and a refractive index of 2.3.

The fourth layer (low refractive layer) was a silicon oxide (SiO ₂ ) layer having a thickness of 90 nm and a refractive index of 1.46.
As Example 4, a film was prepared by sequentially laminating the first to fourth layers, which are the inorganic oxide layers shown below, from the HC layer side. The film forming conditions were set in substantially the same manner as in Example 3 except for the materials. Here, the first layer and the second layer, and the third layer and the fourth layer correspond to the stacked units mentioned in the fifth embodiment, respectively.

The first layer (medium refractive layer) was a silicon oxide-tin oxide (SiO ₂ —SnO ₂ ) layer having a film thickness of 25 nm and a refractive index of 1.9.
The second layer (low refractive layer) was a silicon oxide (SiO ₂ ) layer having a thickness of 28 nm and a refractive index of 1.46.
The third layer (medium refractive layer) was a silicon oxide-tin oxide (SiO ₂ —SnO ₂ ) layer having a film thickness of 85 nm and a refractive index of 1.9.

The fourth layer (low refractive layer) was a silicon oxide (SiO ₂ ) layer having a thickness of 90 nm and a refractive index of 1.46.
In Examples 3 and 4, the film formation surface was used as a measurement surface, and the back surface was roughened with sandpaper to block reflection, and then subjected to measurement of a 5 ° regular reflection spectrum. The measurement results are shown in FIGS.

  As shown in the results shown in FIGS. 9 and 10, it was found that in both Examples 3 and 4, the visible light reflectance in the vicinity of a wavelength of 550 nm that can be easily detected by humans can be reduced. Moreover, it can be confirmed that the visible light reflectance is suppressed to some extent in other wavelength regions. Thereby, when the films of Examples 3 and 4 are disposed on the display surface, good antireflection characteristics can be expected.

In Examples 3 and 4, since the HC layer is formed, it can be expected that the above-described good antireflection characteristics will be exhibited over a long period of time.
In Examples 3 and 4, a two-unit laminated structure is used. However, even with a laminated structure having more than this unit, the same or higher reflectance prevention characteristics can be expected. However, in this case, attention should be paid to a decrease in visible light transmittance.

<Other matters>
In the above embodiment, the case where the MS layer is formed only on one main surface of the transparent planar member has been shown in order to explain the characteristics of each component, but the present invention is naturally not limited to this, An MS film can be formed on each main surface. In this case, the configuration of the present invention (HC layer having an inorganic oxide component-rich region by composition separation or inorganic oxide nanoparticle-dispersed HC layer) is applied to each of the HC layers provided on both peripheral surfaces of the transparent substrate. Keep in mind what to do.

The touch panel film of the present invention is a touch panel for a car navigation system that is assumed to be used in outdoor use with a relatively large amount of ultraviolet irradiation or in high temperature and high humidity conditions, in addition to a touch panel applied to a display of a personal computer. It can be used for a wide range of purposes.
Of course, the film for a touch panel of the present invention can be further improved in reliability by being used as a constituent element of a touch panel mounted on any other display.

1, 1A-1E, 1a, 1b Film for touch panel 2 Touch panel 3 Multilayer inorganic oxide layer (MS film)
4 Transparent planar member 13, 13a, 13b Transparent conductive film (transparent electrode film)
40 Base film 41, 41A, 44, 44A Hard coat (HC) layer 42, 42a, 42b Middle refractive layer (first refractive layer)
43, 43a, 43b Low refractive layer (second refractive layer)
45 Lubricant layer 46 Low density siloxane layer 50 Nanoparticles (inorganic oxide fine particles)
131, 132, 141, 142 Lead line 133 Connection line 131a, 132a, 141a, 142a Electrode terminals 302, 303, 304, 305 Lead lines 302a to 305a Electrode terminal 301 Flexible substrate 410, 440 Inorganic oxide component rich region

Claims (12)

A film for a touch panel in which an ultraviolet curable resin layer and a transparent inorganic oxide layer are sequentially laminated on one surface of a transparent substrate,
The thickness of the transparent inorganic oxide layer is 30 nm or more and 300 nm or less,
The ultraviolet curable resin layer contains both an organic component and an inorganic oxide, and is an inorganic material with respect to the number A of organic elements in the organic component of the layer in a region within a depth of 10 nm from at least the surface in contact with the transparent inorganic oxide layer. The ratio B / A of the number of inorganic elements B in the oxide is 0.05 to 0.35 in terms of the number of elements. A film for a touch panel. The inorganic oxide component contains at least one element of Si, Zr, Sn, Sb,
The ratio B / A is an element number ratio (Si + Zr + Sn + Sb) / C of the sum of each element constituting the inorganic oxide component contained in the ultraviolet curable resin layer and carbon of the organic component,
2. The touch panel film according to claim 1, wherein the ratio B / A is set to be constant or gradually decreased in the depth direction from the surface of the ultraviolet curable resin layer. The ultraviolet curable resin layer has an average primary particle size of 5 to 40 nm, and inorganic oxide fine particles composed of at least one of SiO ₂ , ZrO ₂ , SnO ₂ , and ATO are 20 wt% or more and 90 wt%. The film for a touch panel according to claim 1, wherein the film is dispersed in the following range. The transparent inorganic oxide layer has a multilayer structure in which at least two or more different layers are laminated. The film for a touch panel according to any one of claims 1 to 3. The touch panel according to claim 4, wherein the transparent inorganic oxide layer is formed by laminating a first layer having a first refractive index and a transparent conductive film in the same order from the ultraviolet curable resin layer side. Film. The transparent inorganic oxide layer includes a second layer having a second refractive index different from the first refractive index, a first layer having a first refractive index, and a transparent conductive film from the ultraviolet curable resin layer side. These are laminated | stacked in the same order. The film for touchscreens of Claim 4 characterized by the above-mentioned. The transparent inorganic oxide layer is a transparent conductive film directly disposed on the ultraviolet curable resin layer,
The thickness of the said transparent conductive film is 30 nm or more. The film for touch panels of Claim 4 characterized by the above-mentioned. The transparent inorganic oxide layer includes a second layer having a second refractive index different from the first refractive index and a first layer having the first refractive index in the same order on the ultraviolet curable resin layer. Laminating, repeating the lamination unit of the second layer and the first layer two or more,
The film for touch panels according to claim 4, wherein an ultraviolet curable resin layer and a transparent conductive film are sequentially laminated on the other surface of the transparent substrate. A layer containing a fluorine-based lubricant is laminated on the top surface of the transparent inorganic oxide layer,
The transparent conductive film is formed in the other surface of a transparent substrate. The film for touchscreens of Claim 8 characterized by the above-mentioned. The said transparent inorganic oxide layer is a low density siloxane layer, and the transparent conductive film is formed in the other surface of a transparent substrate. The film for touchscreens of Claim 4 characterized by the above-mentioned. A pair of substrates with a transparent conductive film is a touch panel arranged with a certain interval in a state where the transparent conductive films face each other,
At least one of the said board | substrates with a transparent conductive film is the film for touchscreens in any one of Claims 5-7. The touchscreen characterized by the above-mentioned. A pair of substrates with a transparent conductive film is a touch panel arranged with a certain interval in a state where the transparent conductive films face each other,
At least one of the substrates with the transparent conductive film is a film for a touch panel according to any one of claims 8 to 10,
A touch panel film is disposed such that the transparent inorganic oxide layer is oriented on the touch side surface.

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