JP6411389B2 - Front protective plate for display device and display device - Google Patents

Description

  The present invention relates to a front protective plate for a display device and a display device including the same. In particular, the present invention relates to a front protective plate for a display device having a light shielding layer in which a white color is not easily yellowed, and a display device including the same.

  In recent years, touch panels have been rapidly spread as position input devices used in combination with display panels in various display devices such as smartphones and tablet PCs (personal computers). Various types of touch panels, such as electromagnetic induction systems and resistive film systems, have been known for a long time, and have been used for various applications. Recently, multi-touch (multi-point simultaneous input) has attracted particular attention. It is a capacitive touch panel capable of

FIG. 11 is a diagram schematically illustrating an example of the display device 200 including the touch panel 20. FIG. 11A is an exploded plan view, and the cross-sectional view of FIG. 11B is the exploded plan view of FIG. 11A when the front protective plate 40 for a display device is cut along line CC. It is sectional drawing of only the front surface protection board 40 for display apparatuses. The touch panel 20 is disposed on the front side (the front side in the drawing) that is the light output side of the display light from the display panel 30 with respect to the display panel 30. Further, in order to protect the touch panel 20, a front protective plate for display device 40 is disposed on the front side of the touch panel 20, which is the side from which the display light from the display panel 30 passes through the touch panel 20 and emits light (Patent Literature). 1, Patent Document 2, Patent Document 3).
As shown in FIG. 11, the display device front protective plate 40 normally has an opaque area A2 at the outer periphery of the display area A1, and a light shielding layer 41 is formed in the opaque area A2. The opaque area A2 prevents the touch panel 20 disposed on the back side of the display device front protective plate 40 from seeing the wiring 7 and connectors on the outer peripheral portion so as not to impair the appearance. Further, visible information 9 such as a product logo is appropriately provided in the opaque region A2, and the opaque region A2 also serves as a decoration part of the front protective plate 40 for display device.

Between the members of the front protective plate 40 for the display device, the touch panel 20 and the display panel 30, a resin is used without providing a space in order to reduce display light loss due to interface reflection and external light reflection to make the display easier to see. In some cases, the layers are buried in close contact.
Further, in order to meet the demands for thinning, lightening, and reduction in the number of parts, various integrations such as integration of the front protective plate 40 for the display device and the touch panel 20 or integration of the touch panel 20 and the display panel 30 are possible. A form has been proposed and put into practical use (Patent Document 1, Patent Document 2).

JP 2009-193587 A Utility Model Registration No. 3153971 JP 2008-266473 A ([0009], [0030], FIG. 2)

By the way, the light shielding layer 41 in the opaque region A2 is usually black from the viewpoint of light shielding properties, but recently, a white design such as pure white or ivory color is desired by changing the taste. Sometimes.
Therefore, if the shielding layer 41 is constituted by a white resin layer containing a white pigment in a resin binder instead of a black pigment such as carbon black so that a white design can be expressed, a white color is temporarily provided. The design can be expressed. However, in this configuration, it has been found that the color of the light shielding layer 41 is yellowed by heat and deteriorates the design. The yellowing is considered to be caused by the resin component used in the light shielding layer 41 being denatured by heat. When the color of the light shielding layer 41 is black, the resin component is not noticeable even when yellowing occurs. I think that the. In particular, when the transparent electrode for the touch panel is added to the front protective plate 40 for the display device in addition to the light shielding layer 41 for the integration of the components, the yellowing is post-baked or fired when the transparent electrode is formed. This was remarkable because a high temperature of 200 ° C. or higher was applied by the heat treatment.

  Therefore, an object of the present invention is to make it difficult for the light-shielding layer expressing a white color to be yellowed in the front protective plate for a display device. Moreover, it is providing the display apparatus provided with such a front surface protection plate for display apparatuses.

In the present invention, a front protective plate for a display device and a display device having the following configuration are provided.
(1) A front protective plate for a display device having a central display area and an opaque area that is provided on an outer periphery of the display area and shields visible light,
A light-transmitting substrate, and a light-shielding layer provided in the opaque region on any one of a first surface of the light-transmitting substrate and a second surface opposite to the first surface; ,
An oxygen barrier layer provided on the one surface so as to cover the light shielding layer;
A transparent electrode formed on the one surface and extending from the display region to a portion of the opaque region having the light shielding layer, and made of a transparent conductor thin film;
An opaque wiring provided on the one surface so as to be electrically connected to the transparent electrode at a portion of the light shielding layer;
Having at least
The light-shielding layer has a white color by having a white resin layer,
The white resin layer includes at least a white pigment in a resin binder made of a cured curable resin.
Front protective plate for display devices.

(2) A front protective plate for a display device having a central display area and an opaque area that is provided on the outer periphery of the display area and shields visible light,
A light-transmitting substrate, and a light-shielding layer provided in the opaque region on any one of a first surface of the light-transmitting substrate and a second surface opposite to the first surface; ,
A transparent electrode provided on the one surface so as to extend from the display region to a portion of the opaque region having the light shielding layer;
An opaque wiring provided on the one surface so as to be electrically connected to the transparent electrode at a portion of the light shielding layer;
Having at least
The light-shielding layer has a white color by having a white resin layer,
The white resin layer includes at least a white pigment in a resin binder made of a cured product of a curable resin,
The transparent electrode is made of a conductive layer whose layer itself is opaque, and is made of a conductive mesh that ensures transparency by being formed in a mesh shape at least in the display region.
Front protective plate for display devices.

(3) A front protective plate for a display device having a central display area and an opaque area provided on the outer periphery of the display area and shielding visible light,
A light-transmitting substrate, and a light-shielding layer provided in the opaque region on any one of a first surface of the light-transmitting substrate and a second surface opposite to the first surface; ,
A first transparent electrode provided on the one surface and extending from the display region to a portion of the opaque region having the light shielding layer, made of a transparent conductive thin film, insulated from each other and intersecting each other And a transparent electrode composed of a second transparent electrode;
An opaque wiring provided on the one surface so as to be electrically connected to the transparent electrode at a portion of the light shielding layer;
An overcoat layer that electrically insulates the first transparent electrode and the second transparent electrode from each other at their intersections;
Having at least
The light-shielding layer has a white color by having a white resin layer,
The white resin layer includes at least a white pigment in a resin binder made of a cured product of a curable resin,
The transparent electrode and the overcoat layer are formed at a temperature of less than 200 ° C.,
Front protective plate for display devices.
(4) A display device comprising the front protective plate for a display device according to any one of (1) to (3) and a display panel.
(5) The display device according to (4), wherein the display panel is a liquid crystal panel or an electroluminescent panel.

According to the front protective plate for a display device of the present invention, the light-shielding layer that expresses a white color can be made difficult to yellow.
According to the display device of the present invention, the display device front protective plate included in the display device has the above-described effect.

The partial expanded sectional view which shows typically 1st Embodiment of the front surface protection plate for display apparatuses by this invention. The top view which looked at the front surface protection plate for display apparatuses of 1st Embodiment from the 2nd surface S2 side. The partial expanded sectional view which shows typically 2nd Embodiment of the front surface protection plate for display apparatuses by this invention. It is the top view which looked at the front-surface protection plate for display apparatuses of 2nd Embodiment from the 2nd surface S2 side, (a) is a general view, (b) is a mesh shape example of an electroconductive mesh. The partial expanded sectional view which shows typically 3rd Embodiment of the front surface protection plate for display apparatuses by this invention. The graph which shows the reflection spectrum for demonstrating the meaning of yellowing. The graph which illustrates the improvement effect of yellowing on an xy chromaticity diagram. Sectional drawing explaining the measuring method of the color of a light shielding layer. The partial expanded sectional view explaining visible information. Sectional drawing which illustrates typically one Embodiment of the display apparatus by this invention. An exploded plan view (a) showing an example of a conventional front protective plate for a display device and a display device, and a cross-sectional view (b) of the front protective plate for a display device along line CC in the exploded plan view.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are conceptual diagrams, and the scale relations, aspect ratios, and the like of components may be exaggerated as appropriate for convenience of explanation.

[A] Definition of terms:
Hereinafter, definitions of main terms used in the present invention will be described here.

The “front side” is the side from which the display light from the display panel is emitted when the front protective plate for display device is used in combination with the display panel in the front protective plate for display device or other components. This means the side that observes the panel display.
The “back side” means a side opposite to the “front side”, and means a side where display light of the display panel enters in the front protective plate for display device or other components.
Any one of the “first surface” and the “second surface” is the “front side”, and which surface is the “front side” is arbitrary. In the present specification, the surface on which the light shielding layer 2 is necessarily provided is referred to as a “second surface”, and this second surface is the back surface.

[B] Front protective plate for display device:
Hereinafter, a front protective plate for a display device according to the present invention will be described.

<< First Embodiment: Method A >>
A first embodiment of a front protective plate for a display device according to the present invention will be described with reference to a partially enlarged sectional view of FIG. 1 and a plan view of FIG. In the present embodiment, both the transparent electrode 6 and the wiring 7 are for touch panels. The transparent electrode 6 is an example formed for a projected capacitive touch panel.

  A front protective plate 10 for a display device according to this embodiment shown in FIGS. 1 and 2 has a central display area A1 and an opaque area A2 that is provided on the outer periphery of the display area A1 and shields visible light. . The front protective plate 10 for a display device according to the present embodiment includes two surfaces, a translucent substrate 1, a first surface S1 of the translucent substrate 1, and a second surface S2 opposite to the first surface S1. Of these, on the second surface S2, a white resin layer 3 is provided as the light shielding layer 2 provided in the opaque region A2, and the white resin layer 3 causes the light shielding layer 2 to exhibit a white color.

  In the present embodiment, the light shielding layer 2 is provided on the second surface S2 of the translucent substrate 1, and the first surface S1 is viewed through the display area A1 with the second surface S2 on the back side. It is the form assumed to be used toward the viewer V side of the display panel.

The white resin layer 3 contains at least a white pigment as a coloring pigment in a resin binder made of a cured product of a photosensitive resin as a curable resin.
The white resin layer 3 is formed by applying a white photosensitive resin composition containing a white pigment and an uncured photosensitive resin on the translucent substrate 1 and patterning it by a photolithography method. .

  Thus, in the present embodiment, the white design expression is expressed by the light-shielding layer 2 while the white resin layer 3 expresses white as a white color, and the light-shielding layer 2 is a constituent layer of the light-shielding layer 2 and is shielded together with the backing layer 8 described later. It is a layer that also secures the nature. For this reason, the light shielding layer 2 is a decorative layer for decorating the front protective plate 10 for a display device in addition to the function of hiding the wiring 7 and the like.

  In order to prevent yellowing of the white design, in the present embodiment, the oxygen blocking layer 4 is provided on the surface of the second surface S2, which is one surface after the light shielding layer 2 of the translucent substrate 1 is formed. Is formed on the entire surface of the second surface S2 so as to cover the entire surface of the white resin layer 3 and including the display region A1. Since the oxygen blocking layer 4 is transparent, it can also be formed in the display area A1.

In the present embodiment, in order to improve the light shielding property of the light shielding layer 2, on one surface after the white resin layer 3 and the oxygen blocking layer 4 as the light shielding layer 2 of the translucent substrate 1 are formed. A backing layer 8 is formed immediately above the white resin layer 3 on the surface of a certain second surface S2.
The backing layer 8 is formed on the white resin layer 3 via an oxygen blocking layer 4 described later. That is, the backing layer 8 is formed on the surface of the white resin layer 3 in contact with the surface of the oxygen blocking layer 4 after the oxygen blocking layer 4 is formed.
The backing layer 8 is formed as a black resin layer in the present embodiment, and this black resin layer is a white resin by a black resin composition in which the white pigment contained in the white resin layer 3 is replaced with a black pigment. It is formed in the same manner as the resin layer 3.

  In the present embodiment, on the surface of the second surface S2, which is one surface of the translucent substrate 1 after the light shielding layer 2 composed of the white resin layer 3 and the backing layer 8 and the oxygen blocking layer 4 are formed. The first overcoat layer 5a is formed on the entire surface.

On the surface of the first overcoat layer 5a, the opaque area A2 in which the light shielding layer 2 is formed and the opaque wiring 7 itself, and the touch panel extending from the display area A1 so as to be electrically connected to the wiring 7 The first transparent electrode 6a among the transparent electrodes 6 for position detection is formed.
In the drawing, the wiring 7 is schematically drawn only for the first transparent electrode 6a.
The first transparent electrode 6a and the second transparent electrode 6b of the transparent electrode 6 are also schematically drawn.

In the present embodiment, a touch panel structure in which the first transparent electrode 6a and the second transparent electrode 6b are formed on the same surface as the transparent electrode 6 for position detection of the touch panel is employed. That is, the first transparent electrode 6a and the second transparent electrode 6b are formed on the surface of the second surface S2, which is the same surface of the translucent substrate 1.
For this reason, the first transparent electrode 6a and the second transparent electrode 6b are formed to be insulated from each other on the surface of the first overcoat layer 5a.
Various patterns are known for the pattern of the first transparent electrode 6a and the second transparent electrode 6b in the projection capacitive method, and there is no particular limitation. Typically, the plurality of first transparent electrodes 6a extend in the first direction, and the second transparent electrode has a direction intersecting the first direction, usually a direction orthogonal thereto as the second direction. 6b is a pattern extending in the second direction. The same applies to the present embodiment as shown in the plan view of FIG.

The intersection of the first transparent electrode 6a and the second transparent electrode 6b is insulated by the third overcoat layer 5c. The third overcoat layer 5c is necessary at least at the intersection between the first transparent electrode 6a and the second transparent electrode 6b. Only one of the first transparent electrode 6a and the second transparent electrode 6b is formed on the same surface in a pattern in which the intersection with the other electrode is missing. An overcoat layer 5c is formed, and thereafter, a transparent electrode is formed as a connection portion that electrically connects the missing portion.
Referring to the cross-sectional view of FIG. 1, since the transparent electrode 6 on the side close to the translucent substrate 1 is the first transparent electrode 6a, the intersecting portion is after the first transparent electrode 6a is formed. A third overcoat layer 5c is formed on the intersecting portion, a transparent electrode for connection is formed across the intersecting portion, and the second transparent electrode 6b is completed.

  Both the first transparent electrode 6a and the second transparent electrode 6b extend from the position detection region in the central display region A1 to a portion overlapping the light shielding layer 2 in the opaque region A2, and are electrically connected to the wiring 7. ing.

  Furthermore, in the present embodiment, after the second transparent electrode 6b is formed, the second over electrode is almost entirely formed on the second surface S2 on the side where the transparent electrode 6 and the wiring 7 of the translucent substrate 1 are formed. A coat layer 5b is formed to protect the surface on the back side of the front protective plate 10 for a display device from scratches, including the surfaces of the first transparent electrode 6a and the second transparent electrode 6b. Although not shown, the second overcoat layer 5b does not form a portion where the wiring 7 is connected to the control circuit via a flexible printed wiring board (FPC), and exposes the wiring 7.

With the above-described configuration, the display device front protective plate 10 according to the present embodiment can express a white color design as the design expressed by the light shielding layer 2. In addition, in addition to the transparent electrode 6 that requires heat treatment at 200 ° C. or higher, first, second, and third overcoat layers 5a, 5b, and 5c that require heat treatment at 200 ° C. or higher are formed. In spite of this, the oxygen blocking layer 4 prevents the yellowing of white that the light shielding layer 2 is to produce.
Furthermore, it also has a touch panel function, which is effective for reducing the number of parts and reducing the weight.

  In the present invention, the front protective plate 10 for a display device includes the transparent electrode 6 and the wiring 7 including the first embodiment. Since the transparent electrode 6 and the wiring 7 are for a touch panel in the present embodiment, in the present embodiment, the front protective plate 10 for a display device is also used as a touch panel substrate. Such integration with the touch panel function can be achieved by reducing the number of parts and reducing the thickness in accordance with the integration of some of the functions required for the touch panel. In the form in which all the functions are integrated, an effect of further reducing the number of parts can be obtained.

  Hereinafter, each component will be further described in detail.

[Display area A1 and opaque area A2]
As illustrated in the plan view of FIG. 2, the display device front protective plate 10 has a display area A <b> 1 at the center and an opaque area A <b> 2 that shields visible light at the outer periphery of the display area A <b> 1. The display area A1 is an area through which the display panel displays the content displayed by the display device front protective plate 10 when the display device front protective plate 10 is applied to the display panel. The opaque area A2 is an opaque area for hiding the wiring 7 and the connector, or for hiding the wiring and the connector that the display panel has on the outer periphery. Further, the opaque area A2 is an area that also serves as a decoration portion by visible information such as a color expressed by the logo, a logo or a mark provided as appropriate.

[Translucent substrate 1]
The translucent substrate 1 is not particularly limited as long as it is transparent to at least visible light and has a mechanical strength capable of protecting the surface of the display panel to which the front protective plate 10 for a display device is applied. Typically, a glass plate can be used. In particular, as the glass plate, chemically strengthened glass is preferable in that it has excellent mechanical strength compared to float glass and can be made thinner by that amount. Chemically tempered glass is typically glass whose mechanical properties have been reinforced by a chemical method by exchanging part of ionic species such as by replacing sodium with potassium in the vicinity of the surface of the glass.
Resin can also be used for the translucent substrate 1. For example, as the resin, an acrylic resin, a polycarbonate resin, a cycloolefin resin, a polyester resin, or the like can be used. By using a resin for the light-transmitting substrate 1, the weight can be reduced and flexibility can be provided.

[Light shielding layer 2]
The light shielding layer 2 in the present embodiment is formed in a portion of the opaque region A2 of the second surface S2 on the back side which is the display panel side of the translucent substrate 1. The light shielding layer 2 is provided in the entire area in the opaque area A2. In other words, the opaque region A2 is formed as an opaque region by the light shielding layer 2.
In the present embodiment, the light shielding layer 2 is formed in the opaque region A2 of the surface of the second surface S2 as one of the first surface S1 and the second surface S2 of the translucent substrate 1.
The light shielding layer 2 has a wiring 7 and a control circuit on its outer peripheral part with respect to a central position detection region as a touch panel, or a wiring and a control circuit on its outer peripheral part with respect to its central display region. In the display device combined with the display panel, it has a function of preventing the appearance from being impaired.

  The light shielding layer 2 has a function of improving the appearance design as well as a light shielding property for hiding unnecessary parts. That is, in this invention, it also has a function as a decoration layer expressing the design of a white color. Further, the light shielding layer 2 is configured such that yellowing due to heating of the white resin layer 3 does not easily occur due to the oxygen blocking layer 4.

  The light-shielding property of the light-shielding layer 2 depends on the required specifications and expression color, but in terms of transmittance, it is 3% or less (1.5 or more at the optical density OD), more preferably 1% or less. (Optical density OD2.0 or higher), more preferably 0.01% or lower (optical density OD4.0 or higher) in transmittance is desirable.

(What is a white color?)
In the present invention, to exhibit a white color, in addition to pure white (pure white), ivory, beige, reddish white (light pink), yellowish white that is yellowish white, Bluish white, bluish white, greenish white, greenish white, purple white, purple white, brownish white, brownish white, blackish gray (light gray), silvery white It includes chromatic and whitish colors, and achromatic and whitish colors such as silver white and gold white.
If these white colors are numerically shown, they can be defined using various color systems. In particular, if shown by the Munsell color system (JIS Z 8721), which is one of the conventional color systems, in the present invention, the white color is a lightness of 8.0 or more in the Munsell color system. Further, it can be defined as a color having a saturation of 2.0 or less. There is no particular limitation on the hue. Any color is acceptable.

In the Munsell color system, all colors are represented by three attributes of brightness, saturation, and hue. In the Munsell color system, this brightness is 10 for the brightest ideal white and 0 for the darkest ideal black. In the present invention, since it is a white color, the brightness is set to 8 even if it is small, and is set to 8.0 or more. In the Munsell color system, the saturation is 0 for an achromatic color, the value increases as the color becomes darker, and the maximum value varies with lightness and hue but is 14 at maximum. In the present invention, even if a color other than white is added, it is a whitish color, so the saturation is 2 at the maximum and is 2.0 or less.
The three attributes of the Munsell color system can be measured with a commercially available spectrophotometer, spectrophotometer, or the like.

  A white color in which the effect of the present invention, in which yellowing is less noticeable, is a whitish color. If this is expressed by the Munsell color system, it is more effective in the case of a color of 9.0 or more in lightness, a color of 1.0 or less in saturation, and the lightness is 9.0 or more. And a color with a saturation of 1.0 or less is more effective.

[White resin layer 3]
The white resin layer 3 is formed of a layer containing a color pigment for expressing a white color in a resin binder made of a cured product of a curable resin.
In the present embodiment, a photosensitive resin is used as the curable resin. For this reason, the white resin layer 3 includes a layer containing a color pigment for expressing a white color in a resin binder made of a cured product of a photosensitive resin.

  The formation method of the white resin layer 3 is not particularly limited. For example, a colored photosensitive resin composition containing a colored pigment and an uncured photosensitive resin is applied on the surface of the light-transmitting substrate 1. After coating, the film can be formed by a so-called photolithography method in which exposure is performed in a predetermined pattern and development is performed. In the present embodiment, the white resin layer 3 is formed by a photolithography method.

(Color pigment)
As a color pigment used for the white resin layer 3, a white pigment is usually used as a main pigment. Furthermore, in order to express white colors such as ivory and light gray other than pure colors, color pigments exhibiting any color including black pigments can be used in combination.

As the white pigment, titanium oxide, silica, talc, kaolin, clay, barium sulfate, calcium hydroxide, and the like can be used.
Of these, titanium oxide is typical. Titanium oxide has crystal types, rutile type and anatase type, but the rutile type is preferred. In this embodiment, rutile type titanium oxide is also used. This is because the rutile type has a lower catalytic activity than the anatase type, and the binder resin is not easily altered during heating.

  As the colored pigment other than white, for example, a red pigment, a yellow pigment, a blue pigment, a green pigment, a purple pigment, a black pigment, and the like can be used.

  As the red pigment, for example, a red pigment such as diketopyrrolopyrrole, anthraquinone, or perylene can be used, and as the yellow pigment, for example, a yellow pigment such as isoindoline or anthraquinone is used. The blue pigment can be a blue pigment such as copper phthalocyanine or anthraquinone, and the green pigment can be a green pigment such as phthalocyanine or isoindoline. As the purple pigment, a quinacridone-based or dioxazine-based purple pigment can be used.

More specifically, for example, an anthraquinone pigment red 177 (PR177) is used as a red pigment, an isoindoline pigment yellow 139 (PY139) is used as a yellow pigment, and a copper is used as a blue pigment. Phthalocyanine pigment blue PB15: 6 (PB15: 6), etc. can be used.
As the purple pigment, quinacridone-based quinacridone (PV19), dioxazine-based dioxazine violet (PV23), or the like can be used.

Examples of the black pigment include titanium black (low-order titanium oxide, titanium oxynitride, etc.), carbon black, and the like.
The black pigment can be used in a color with reduced brightness by being used together with a white pigment or a color pigment of a color other than the white pigment together with the white pigment.

  The size of the color pigment particles is usually 1 μm or less in average particle size, preferably about 0.03 to 0.5 μm.

  The color pigment may be appropriately selected according to the white color to be expressed, and only the white pigment may be used. Accordingly, the color pigments may be used alone, or a plurality of types of color pigments of the same type or different colors may be used.

  The white resin layer 3 can adjust the opacity or transparency of the white resin layer 3 itself depending on the film thickness and the content of the color pigment. The film thickness of the white resin layer 3 is, for example, 1 to 50 μm.

  The content of the color pigment depends on the transparency of the white color expressed by the white resin layer 3, the denseness expected of the white color, etc., but the white resin layer containing the color pigment and the resin binder The pigment concentration expressed as a percentage of the amount of the colored pigment with respect to the total solid content of 3, for example, is about 10 to 80%. In other words, the color pigment is in the range of 10 to 80 parts by mass with respect to 100 parts by mass of the total solid content of the white resin layer 3.

(Curable resin)
As said curable resin used as the resin component of the resin binder which disperse | distributes and holds a color pigment, 1 or more types of resin chosen from photosensitive resin and a thermosetting resin can be used.

  Examples of the photosensitive resin include photosensitive resins having a photoreactive group such as an acrylic resin, an epoxy resin, a polyimide resin, a polyvinyl cinnamate resin, and a cyclized rubber. One or more can be used. In the acrylic resin, for example, a photosensitive resin composed of an alkali-soluble resin, a polyfunctional acrylate monomer, a photopolymerization initiator, and other additives can be used as a resin component of the resin binder.

As the alkali-soluble resin, one or more kinds of methacrylic acid ester copolymers such as benzyl methacrylate-methacrylic acid copolymer, cardo resins such as epoxy acrylate having a bisphenol fluorene structure, and the like can be used.
Examples of the polyfunctional acrylate monomers include trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like. The above can be used.
In the present invention, (meth) acrylate means either methacrylate or acrylate.

  As the photopolymerization initiator, one or more alkylphenone series, oxime ester series, triazine series, titanate series and the like can be used. For example, in the alkylphenone series, (2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Irgacure (registered trademark) 907, manufactured by BASF Japan Ltd.)), 2- In benzyl-2-dimethylamino-1- (4-monofoliophenyl) butanone-1 (Irgacure (registered trademark) 369, manufactured by BASF Japan Ltd.), an oxime ester system, 1,2-octanedione, 1- [ 4- (phenylthio) phenyl]-, 2- (O-benzoyloxime) (Irgacure (registered trademark) OXE01, manufactured by BASF Japan Ltd.) and the like can be used.

  As the thermosetting resin, for example, one or more of acrylic resin, epoxy resin, polyester resin, polyimide resin, and the like can be used.

  In addition to the above, the resin binder of the white resin layer 3 may contain various known additives such as a photosensitizer, a dispersant, a surfactant, a stabilizer, and a leveling agent.

(Formation of white resin layer 3)
The formation method of the white resin layer 3 is not particularly limited in the present invention, but the white resin layer 3 is formed of a colored pigment and a yellow pigment in a resin binder containing an uncured product of the curable resin. It can be formed by a white curable resin composition containing a variation correcting compound.
The white curable resin composition further contains a solvent for the purpose of adjusting the coating suitability when the resin composition is applied on the surface of the light-transmitting substrate 1 or the printing suitability when printing. Can be included.
As the solvent, for example, one or more of propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl cellosolve, 3-methoxybutyl acetate, and the like can be used.

  When a photosensitive resin is used as the curable resin, a material for a color resist that has been conventionally adjusted for color filter use may be used as the color pigment and the uncured product of the photosensitive resin.

  When a photosensitive resin is used as the curable resin, a method of applying the white curable resin composition on the surface of the light-transmitting substrate 1 is, for example, a spin coating method, a roll coating method, a die coating method, or a spray coating method. Further, a known coating method such as a bead coating method can be used.

  When a photosensitive resin is used as the curable resin, a white curable resin composition (white photosensitive resin composition) is applied on the surface of the translucent substrate 1 and then exposed using a photolithography technique. The white resin layer 3 having a predetermined pattern can be formed on a part of the surface of the translucent substrate 1 by patterning through predetermined steps such as development and baking.

  When a thermosetting resin is used as the curable resin of the white curable resin composition, the white resin layer 3 having a predetermined pattern is formed into a pattern by printing using an ink made of the white curable resin composition. Can be formed. There is no restriction | limiting in particular as a printing method, For example, an offset printing method, a flexographic printing method, an inkjet printing method etc. are employ | adopted suitably.

[Oxygen barrier layer 4]
The oxygen blocking layer 4 is a layer that prevents oxygen in the air from coming into contact with the white resin layer 3 that easily yellows. For this reason, the oxygen barrier layer 4 is a layer having a low oxygen permeability.
The oxygen blocking layer 4 may be formed so as to cover at least the white resin layer 3 with the white resin layer 3, but may be formed on the entire surface of the display area A1 and the opaque area A2. When it is formed on the entire surface, a transparent layer is used so as not to hinder the display in the display area A1. In the present embodiment, the oxygen blocking layer 4 is formed as a transparent layer.

The oxygen blocking layer 4 is not particularly limited as long as it exhibits a low oxygen permeability that does not cause yellowing when the white resin layer 3 is exposed to a high temperature during heat treatment of other layers by oxygen. Absent. For example, as the oxygen blocking layer 4, inorganic materials such as silicon oxide, aluminum oxide, silicon oxynitride, silicon nitride, or acrylic resin, polyester resin, epoxy resin, polyvinyl alcohol resin, cellulose resin, polyvinyl cinnamate An organic material such as a resin or a polyimide resin can be used.
The material and thickness of the oxygen blocking layer 4 are such that the oxygen permeability [cm ³ / (m ² · d · atm)] of the layer is 1 under the conditions of JIS K7126-2 Method A, 23 ° C., 50% RH. It is set to be 0 or less, preferably 0.1 or less.
If the oxygen permeability is too large, yellowing may occur and become noticeable, and if it is too small, it will only result in excess performance.
The oxygen blocking layer 4 can be formed by a physical or chemical vapor deposition method such as a sputtering method for an inorganic material, and can be formed by a coating method for a resin material.

[Overcoat layer 5]
Each of the first overcoat layer 5a, the second overcoat layer 5b, and the third overcoat layer 5c can be formed of different materials, but in this embodiment and each embodiment to be described below, Are all made of the same material. Therefore, in the present specification, these are collectively referred to simply as “overcoat layer 5”.

The overcoat layer 5 is preferably a transparent resin, which is also a curable resin in terms of heat resistance, and for example, an epoxy resin, an acrylic resin, a polyimide resin, and the like can be used. A thermosetting epoxy resin or the like can be used. The overcoat layer 5 is also electrically insulating. The overcoat layer 5 can be formed by the same coating method as the light shielding layer 2.
Moreover, as the curable resin, the photosensitive resin described in the white resin layer 3 can be used. In the case of a photosensitive resin, a photolithography method can be used when partially forming.
When the overcoat layer 5 is formed, a heat treatment called post-baking or baking is performed. The heat treatment requires a high temperature of 200 ° C. or higher, and the white resin layer 3 is easily yellowed by the influence of this heat. The heat treatment at 200 ° C. or higher is, for example, 200 ° C. or 230 ° C., and is about 300 ° C. at the maximum. The heat treatment time is about 10-30 mim, usually about 15-30 min.

In the mode A of the present invention in which the oxygen blocking layer 4 is essential, the overcoat layer 5 is not essential. However, when it is necessary to further improve the reliability, the first overcoat layer 5a and the second overcoat layer 5 are used. It is preferable to provide either or both of the overcoat layer 5b. The first overcoat layer 5a improves reliability against migration at the interface between the light shielding layer 2 and the wiring 7, or prevents disconnection of the transparent electrode 6 at the step portion between the formation portion and the non-formation portion of the light shielding layer 2. The second overcoat layer 5b provides the reliability improvement effect by covering the light shielding layer 2, the transparent electrode 6, the wiring 7 and the like as a whole.
In the case where the first transparent electrode 6a and the second transparent electrode 6b intersect each other as in the present embodiment and it is necessary to electrically insulate both electrodes at the intersection, at least the intersection In addition, a third overcoat layer 5c as an insulating layer is required.

[Transparent electrode 6]
In the present invention, the transparent electrode 6 includes a first transparent electrode 6a and a second transparent electrode 6b that are formed to be insulated from each other.
The first transparent electrode 6a and the second transparent electrode 6b are all made of the same material in the same embodiment in this embodiment and each embodiment to be described later. Therefore, in the present specification, when these are collectively referred to, they are also simply referred to as “transparent electrode 6”.

In the present embodiment, the transparent electrode 6 is a transparent conductor thin film whose layer itself is transparent. Examples of the transparent electrode 6 made of a transparent conductive thin film include ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), AZO (Aluminum Zinc Oxide), and the like. What formed the pattern of the transparent conductor thin film can be used.
When the transparent electrode 6 is formed as a transparent conductor thin film, a heat treatment called post-baking is performed in order to increase conductivity. The heat treatment requires a high temperature of 200 ° C. or higher, and the white resin layer 3 is easily yellowed by the influence of this heat.

[Wiring 7]
For the wiring 7, for example, a metal (including alloys thereof) such as silver, gold, copper, chromium, platinum, aluminum, palladium, and molybdenum can be used. For example, a metal layer of an alloy (also referred to as APC) made of silver, palladium, and copper, which is formed by sputtering and then patterned by photolithography, can be used.
When the wiring 7 is formed, heat treatment at a high temperature of 200 ° C. or higher is usually unnecessary.

[Backing layer 8]
In the present embodiment, as illustrated in FIG. 1, the light shielding layer 2 also has a backing layer 8 on the back side of the white resin layer 3. The backing layer 8 here is provided via the oxygen barrier layer 4. As a result, the light shielding layer 2 is composed of the white resin layer 3 and the backing layer 8 in this order from the translucent substrate 1 side.
The backing layer 8 is preferably provided as a layer for supplementing the light shielding property when the white resin layer 3 alone is insufficient in the light shielding property. As the backing layer 8, for example, a black layer or a reflective layer can be used. The black layer absorbs light to improve the light shielding property, and the reflective layer reflects light to improve the light shielding property.
As the black layer, for example, a black resin layer containing a black pigment in a resin binder can be used. Also in this embodiment, a black resin layer is used.
As the reflective layer, for example, a metal reflective layer made of a metal thin film containing silver, aluminum, or the like can be used.

  In the present invention, the backing layer 8 is not essential. However, when the backing layer 8 is used and the backing layer 8 is also a white color in the resin layer, and there is a concern about yellowing, the oxygen blocking layer 4 is formed with the white resin after the backing layer 8 is formed. It is preferably formed so as to cover the backing layer 8 together with the layer 3.

〔Production method〕
Each layer constituting the front protective plate 10 for a display device of the present embodiment is formed as follows, for example. First, the white resin layer 3 that becomes a part of the light shielding layer 2 is formed in a pattern in the region to be the opaque region A2 of the second surface S2 of the translucent substrate 1.
Next, the oxygen blocking layer 4 is formed on the entire surface on the side where the light shielding layer 2 is formed. Thereafter, the backing layer 8 which is the remaining constituent element of the light shielding layer 2 is patterned on the surface of the oxygen blocking layer 4 in the white resin layer 3 to complete the light shielding layer 2.
Next, the first overcoat layer 5a is formed on the entire surface. Next, the wiring 7 is patterned on the portion of the light shielding layer 2 that is the opaque region A2 on the surface of the first overcoat layer 5a. Next, on the surface of the first overcoat layer 5a, as the transparent electrode 6, all of the first transparent electrode 6a and the second transparent electrode 6b where the intersecting portion is divided and lost are simultaneously formed on the same surface. Form a pattern. At this time, the transparent electrode 6a and the transparent electrode 6b are formed in a pattern so as to be formed in contact with the wiring 7 formed on the surface of the light shielding layer 2, respectively.
Next, the third overcoat layer 5c is patterned at the intersection, and the remaining defective portion of the second transparent electrode 6b is patterned across the third overcoat layer 5c. The entire transparent electrode 6b is completed. Finally, by forming the second overcoat layer 5b on the entire surface, the front protective plate 10 for a display device integrated with a touch panel function is created.

<< Second Embodiment: Method B >>
A second embodiment of the front protective plate for a display device according to the present invention will be described with reference to a partially enlarged sectional view of FIG. 3 and a plan view of FIG. 4A is an overall view, and FIG. 4B is an enlarged view showing a mesh shape example of a conductive mesh.

In this embodiment, instead of omitting the oxygen blocking layer 4 provided in the first embodiment, a transparent electrode 6 made of a transparent conductive thin film is formed of a conductive layer whose layer itself is opaque, and a display region This is an example using the transparent electrode 6 made of a conductive mesh in which the conductive layer is formed in a mesh shape in A1. Further, the transparent electrode 6 is made of the same material as the wiring 7.
Since other components are the same as those in the first embodiment, description thereof will be omitted, and here, a transparent electrode 6 using a conductive mesh, which is a new component, will be described.
In addition, in the system B of the present invention as in the present embodiment, whether or not each layer of the overcoat layer 5 is necessary is the same as that in the above-described system A embodiment.

[Transparent electrode 6: Conductive mesh]
The transparent electrode 6 in this embodiment uses a conductive mesh in which an opaque conductive layer is formed in a mesh shape. Since it is an opaque conductive layer, unlike the transparent electrode 6 made of the transparent conductive thin film used in the first embodiment, a heat treatment at 200 ° C. or higher is not necessary to increase the conductivity. And even if it is an opaque electroconductive layer, transparency can also be ensured by forming as an electroconductive mesh. For this reason, the width | variety of the line which comprises the mesh pattern of an electroconductive mesh is 30 micrometers or less from an invisible viewpoint, Preferably it is 10 micrometers or less.

  For the opaque conductive layer, for example, the materials listed in the wiring 7 can be used. That is, for the opaque conductive layer, for example, metals (including alloys thereof) such as silver, gold, copper, chromium, platinum, aluminum, palladium, and molybdenum can be used. For example, a metal layer of an alloy (also referred to as APC) made of silver, palladium, and copper, which is formed by sputtering and then patterned by photolithography, can be used.

  In the present embodiment, the transparent electrode 6 is simultaneously formed as a layer of the same material as the wiring 7. However, in the present invention, the transparent electrode 6 and the wiring 7 may be formed of different materials.

  In the present invention, a material and a method that do not require pattern formation by a photolithography method may be employed for the opaque conductive layer. For example, the transparent electrode 6 can be formed by pattern-printing a conductive ink containing metal particles such as silver, gold, copper, and aluminum and a resin binder as a conductive mesh by a printing method such as inkjet printing.

  The mesh pattern shape of the conductive mesh is not particularly limited. For example, the mesh pattern shape is a square lattice shape shown in FIG. 4B or a triangular lattice shape, a hexagonal lattice shape (honeycomb shape), a brick pile shape, etc., although not shown.

In the front protective plate 10 for a display device according to this embodiment having the above-described configuration, a white color design can be expressed as a design expressed by the light shielding layer 2. In addition, since the transparent electrode 6 is a conductive mesh of a conductive layer that does not require a heat treatment at 200 ° C. or higher, white yellowing that the light shielding layer 2 tries to express is less likely to occur. .
Furthermore, it also has a touch panel function, which is effective for reducing the number of parts and reducing the weight.

<< Third Embodiment: Method C >>
With reference to the partially enlarged sectional view of FIG. 5, a third embodiment of the front protective plate for a display device according to the present invention will be described.
In this embodiment, in the first embodiment, the material of all overcoat layers 5 of the first, second and third overcoat layers 5a, 5b and 5c is changed and formed at a temperature of less than 200 ° C. This is an example of layering.
Since the other components are the same as those in the first embodiment, description thereof will be omitted. Here, the overcoat layer 5 formed as a new component at a temperature of less than 200 ° C. explain.
As in this embodiment, in the system C of the present invention, as the overcoat layer 5, at least the first transparent electrode 6a and the second transparent electrode 6b are electrically insulated from each other at the intersections. The third overcoat layer 5c is an essential layer. At the same time, the transparent electrode 6 includes a first transparent electrode 6a and a second transparent electrode 6b that are insulated from each other and intersect each other.
Further, as in the present embodiment, the first overcoat layer 5a and the second overcoat layer 5b are further provided as the overcoat layer 5 to improve the reliability as in the above embodiment. Can do.

[Overcoat layer 5: low temperature type overcoat layer]
The overcoat layer 5 in this embodiment does not require heat treatment at 200 ° C. or higher, and even if heat treatment is necessary, the overcoat layer 5 can be formed by heat treatment at less than 200 ° C. Adopted. The term “less than 200 ° C.” means, for example, 100 ° C. or more and less than 200 ° C., and preferably about 140 to 180 ° C. even when heated.
Conventionally, heat treatment at 200 ° C. or higher is necessary because even if the overcoat layer 5 is formed by a photolithography method, the unpatterned curing reaction of the layer patterned by exposure is advanced and a high-quality overcoat is obtained. This is because layer 5 is formed.

  In this specification, even if heat treatment is necessary, those that can be formed by heat treatment at less than 200 ° C. or those that do not require heat treatment are collectively referred to as “low temperature type”.

  Various types of resin compositions used for the overcoat layer 5 formed by the photolithography method have been conventionally known. For example, non-polymerizable polymer (A), photopolymerizable compound (B), photopolymerization A polymerizable composition containing an initiator (C) and a solvent (D) as essential components is known.

In order to form the low temperature type overcoat layer 5 with such a polymerizable composition, as the polymerizable composition, for example, thermal polymerization is combined with photopolymerization, and thermal polymerization capable of thermal polymerization to the photopolymerizable compound (B). A polymerizable composition using a compound having a polymerizable functional group and a non-polymerizable polymer (A) using a compound having a thermally polymerizable functional group capable of reacting with the thermally polymerizable functional group is used. The non-polymerizable polymer (A) is a heat-polymerizable polymer.
Examples of the thermally polymerizable functional group in the photopolymerizable compound (B) include an isocyanate group, an amino group, and an epoxy group. For example, it is a polymerizable compound such as a monomer or a prepolymer having both an acryloyl group and an isocyanate group.
Examples of the thermally polymerizable functional group in the non-polymerizable polymer (A) include a hydroxyl group and a carboxyl group. For example, it is an acrylic copolymer having a hydroxyl group and a carboxyl group.
In addition to such a polymerizable compound, a polyfunctional photopolymerizable compound such as dipentaerythritol hexaacrylate (DPHA) can be used in combination as the photopolymerizable compound (B).

  Specific examples of the photopolymerizable composition capable of patterning the low temperature type overcoat layer 5 include the polymerizable compositions shown in the following (I) to (III). .

(I)
Cationic polymerizable compounds having two or more polyfunctional acrylate monomers (A), radical photopolymerization initiators (B), epoxy groups and / or alkoxy groups containing acidic groups such as carboxyl groups and sulfo groups or salts thereof (C) A photopolymerizable composition comprising a siloxane compound (D) having two or more hydrolyzable alkoxy groups, and an acid generator (E). This is a negative photopolymerizable composition capable of alkali development.
The component (A) is, for example, a succinic acid adduct of pentaerythritol triacrylate, a succinic acid adduct of dipentaerythritol pentaacrylate, and the like.
The component (B) is, for example, an acetophenone derivative such as 2-methyl-1- (4- (methylthio) phenyl) -2-morpholino-1-propanone (Irgacure 907 (registered trademark), BASF Japan Ltd.), or , Triazine derivatives, O-acyl oxime (oxime ester) derivatives, benzophenone derivatives, etc.
The component (C) is, for example, an etherified melamine resin obtained by etherifying a methylol group of methylolated melamine with methyl alcohol, ethyl alcohol, or the like, for example, methyl etherified melamine,
The component (D) is, for example, acrylate-modified polysiloxane, 3-acryloyloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and the like.
The component (E) is a compound that generates an acid by heat or light. For example, a sulfonimide compound such as N- (trifluoromethylsulfonyloxy) succinimide and a disulfonyldiazomethane such as bis (trifluoromethylsulfonyl) diazomethane. Compounds, sulfonium salts [onium salts such as bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluorophosphate, and the like.

(II)
An alkali-soluble polymer (A) having a carboxyl group and a hydroxyl group, a photopolymerizable compound (B) having a functional group capable of reacting with a hydroxyl group and a photopolymerizable functional group, a photopolymerization initiator (C), 4- A polymerizable composition comprising a thermal acid generator (D) that generates an acid by heat, such as hydroxyphenyl, benzyl, methylsulfonium hexafluoroantimonate.
The component (B) is, for example, a monomer or a prepolymer having both an acryloyl group and an isocyanate group.

(III)
A polymerizable composition comprising an alkali-soluble copolymer (A) copolymerized with an unsaturated carboxylic acid, a polyfunctional polymerizable compound (B) having an ethylenically unsaturated bond, and a photopolymerization initiator (C).
The component (A) is, for example, an acrylic copolymer having a carboxyl group,
The component (B) is, for example, dipentaerythritol pentamethacrylate (DPPA), dipentaerythritol hexaacrylate (DPHA), etc.
Component (C) is, for example, 4- (phenylthio) phenyldiphenylsulfonium tris (pentafluoroethyl) trifluorophosphate.

Using the photopolymerizable composition that can be formed by a heat treatment (post-bake) of less than 200 ° C. as described above, the white resin layer 3 is yellowed by being formed as the low temperature type overcoat layer 5. It becomes difficult to occur.
As a result, in the front protective plate 10 for a display device in the present embodiment, a white color design can be expressed as a design expressed by the light shielding layer 2. In addition, since the overcoat layer 5 is a low-temperature type overcoat layer 5 formed by a heat treatment at less than 200 ° C., the white yellowing that the light shielding layer 2 is intended to express is less likely to occur. Yes.
Furthermore, it also has a touch panel function, which is effective for reducing the number of parts and reducing the weight.

《What is yellowing》
Here, the meaning of yellowing will be described. Yellowing generally means that the original color is yellowish. In particular, it is easily noticeable when the original color is white such as white. Yellowing and yellowing means that the object absorbs a lot of light having a wavelength of 380 to 550 nm, particularly 400 to 450 nm, in the visible light region, and as a result, the complementary yellow component becomes an object color. It is to be included a lot.

  FIG. 6 is a graph schematically showing a reflection spectrum for explaining the meaning of yellowing. In the case of an ideal white color before yellowing, the reflection spectrum Sw in the visible light region of 380 to 780 nm shows a constant reflection over the wavelength region. When this turns yellow, as shown by the reflection spectrum Sy, in addition to the wavelength range of 380 to 550 nm, the reflectance decreases even in the range exceeding the wavelength of 550 nm. In the present invention, including “reflection spectrum with decreasing rate”, it is called “yellowing”. In the figure, the reflectance gradually decreases from around the wavelength of 700 nm. The term “entirely” means that, in addition to a spectrum in which the reflectance decreases uniformly as the wavelength changes from a long wavelength to a short wavelength, it also includes a wave-like decrease with increase / decrease.

[Example of occurrence of yellowing]
Table 1 and the xy chromaticity diagram of FIG. 7 illustrate the occurrence of yellowing in the light shielding layer 2 composed of the white resin layer 3 and the backing layer 8 of the black resin layer.

Table 1 shows that the white resin layer 3 formed by curing the white resin composition is 200 ° C. when the backing layer 8, the overcoat layer 5, the transparent electrode 6, the wiring 7, and the like are formed thereafter. The total heating time of the above heat treatment is shown.
In Table 1, the conventional form, method A corresponding to the first embodiment, method B corresponding to the second embodiment, method C corresponding to the form of the third embodiment, and method B and method C The difference between the total heating times obtained by accumulating the heat treatment time of 200 ° C. or higher is shown in each of the “method B + C” forms employing both of the above.

  In the table, in each of the oxygen blocking layer 4, the overcoat layer 5, the transparent electrode 6, and the backing layer 8, the heat treatment conditions when heat treatment at 200 ° C. or higher is necessary are all at 230 ° C. for 0.5 h. is there.

  As shown in Table 1, the total heating time is 3.0 h in the past, but the mode A (corresponding to the first embodiment) in which the oxygen blocking layer 4 is provided is the same as the conventional time. Since the time covered with the oxygen blocking layer 4 can be excluded, only the time for forming the oxygen blocking layer 4 needs to be taken into account, and can be reduced to 0.5 h as compared with the conventional case.

  Even in the form of method B using the conductive mesh for the transparent electrode 6 (corresponding to the second embodiment), the total heating time is 2.0 h, which can be reduced compared to the conventional case.

  In the form of the system C (corresponding to the third embodiment) in which the overcoat layer 5 does not require heat treatment at a high temperature and adopts the low temperature type overcoat layer 5, the total heating time is 1.5 h, which is compared with the conventional case. Can be less.

  In the mode B + C form (corresponding to the combination of the second embodiment and the third embodiment) using a conductive mesh for the transparent electrode 6 and employing the low temperature type overcoat layer 5, the total heating time is 5h, which is very small compared to the prior art.

FIG. 7 is a graph illustrating how the white color of the white resin layer 3 after the formation becomes when yellowing occurs. The reflected color obtained by measuring the light shielding layer 2 is indicated by the x and y values of the Yxy color system. In the drawing, the coordinate Cw is a white point indicated by white when the CIE standard light source C is used as the light source.
The coordinate Cs indicates an initial state before the white resin layer 3 formed by curing the resin composition is further formed with another layer.
The coordinate Cy indicates a yellowing state when another layer is formed after the white resin layer 3 is formed and a high heat is applied at 230 ° C. for a total heating time of 3.0 h as a heat treatment at 200 ° C. or higher.
The coordinate CyA is, for example, when the total heating time is 0.5 h according to the method A, the coordinate CyB is, for example, when the total heating time is 2.0 h according to the method B, and the coordinate CyC is, for example, when the total heating time is 1.5 h according to the method C Are shown respectively. Thus, the longer the time of exposure to the high temperature of the heat treatment, the larger the color change due to yellowing.

  The reflected color is measured with a spectrophotometer using a CIE standard light source as a light source, and is measured with the black layer Bk superimposed on the back side of the white resin layer 3 as shown in FIG. This is because when the front protective plate 10 for a display device is applied to the display device, even if light is transmitted from the front side to the back side of the light shielding layer 2, the object from the component that is located behind the light shielding layer 2 and is hidden. This is to prevent the original color of the light shielding layer 2 from being shifted by reflected light including color.

<Deformation>
The front protective plate 10 for a display device of the present invention can take other forms other than the above-described forms. Some of these will be described below.

[Combination with method A]
In Table 1, the method A, the method B, the method C, and the method B + C have been described as measures for making yellowing difficult. However, in the present invention, a combination of different methods can be adopted besides this.
For example, the oxygen blocking effect by the oxygen blocking layer 4 in the method A is moderately reduced by combining the yellowing suppressing effect by the oxygen blocking layer 4 with the yellowing suppressing effect by other methods. This is when it is difficult to occur. As specific examples, system A + B, system A + C, and system A + B + C are used.
The combination with the method A using the oxygen barrier layer 4 has an advantage that the options that can be determined in consideration of the cost of each method, the ease of production, the suitability of the available manufacturing equipment, and the like can be expanded.

[Multi-layer white resin layer 3]
In the above-described embodiment, the white resin layer 3 is formed as a so-called “solid layer” in which the film thickness is constant over the entire opaque region A2. Such a white resin layer 3 may have a single layer structure or a multilayer structure of two or more layers.
When the white resin layer 3 has a multi-layer structure, each layer may be the same color or may represent a whited white color by all layers including layers of different colors.

[Use of transparent electrode 6 and wiring 7]
In the embodiment described above, the use of the transparent electrode 6 and the wiring 7 is a touch panel.
In a form in which the transparent electrode 6 is used for a touch panel, as a position detection system for the touch panel, in a position detection system in which the transparent electrode 6 has two layers on different surfaces, at least one of them may be provided.

  In the present invention, the front protective plate 10 for a display device has a touch panel function, in addition to the transparent electrode 6 and the wiring 7, in addition, for example, a part of the touch panel function such as a connector or a control circuit, or the entire touch panel function. May be integrated.

  The front protective plate 10 for a display device that integrates all the functions necessary for a touch panel can also be called a touch panel. The front protective plate 10 for a display device that integrates a part of functions necessary as a touch panel can also be referred to as a touch panel member.

[Visible information 9]
In the conventional front protective plate 40 for a display device illustrated in FIG. 11, a product logo mark or the like is formed as visible information 9 in the opaque region A <b> 2 where the light shielding layer 2 is formed.
In the present invention, the visible information 9 is not essential, but any visible information 9 such as a product logo, an operation explanation character, symbol, or pattern can be provided for the opaque region A2.

The visible information 9 can be provided, for example, in a non-formation part of the white resin layer 3 in the opaque region A2 so that it can be seen from the front side. The visible information 9 is visible information that is expressed by a color and a shape when the portion of the non-forming portion of the white resin layer 3 is viewed from the front side.
As illustrated in the cross-sectional view of FIG. 9, the visible information 9 is formed by providing a visible information forming layer 9 </ b> L in the non-formed portion of the white resin layer 3, so that the visible information forming layer 9 </ b> L is viewed from the front side. Can be expressed by the color and shape of
As the visible information forming layer 9L, a layer such as a metal layer or a colored resin layer having a color or a surface appearance different from that of the white resin layer 3 can be used. As the metal layer, a metal thin film such as silver or aluminum can be used. As the colored resin layer, a resin composition layer containing a color pigment or metal powder can be used.

  In the case where the visible information forming layer 9L also has a white color, when the white resin layer 3 is covered with the oxygen blocking layer 4, the visible information forming layer 9L is also preferably covered with the oxygen blocking layer 4.

[C] Display device:
The display device according to the present invention is a display device including at least the display device front protective plate 10 and a display panel.

A display device according to the present invention will be described with reference to the embodiment shown in FIG. A display device 100 shown in the figure includes a display device front protective plate 10 and a display panel 30 in order from the front side on the observer V side above the drawing.
The display device front protective plate 10 includes at least a transparent electrode 6 and a wiring 7 as a touch panel function in addition to the light shielding layer 2 including the white resin layer 3 and the overcoat layer 5. The display device front protective plate 10 includes other functions as a touch panel function, for example, a connector, a control circuit, etc., so that a part or all of the functions of the touch panel are integrated. It is good.
In the drawing, it is schematically depicted that the overcoat layer 5 is also provided.

  The transparent electrode 6 and the wiring 7 included in the front protective plate 10 for a display device are typically for a projected capacitive touch panel capable of multi-touch (multi-point simultaneous input). Any of various known position detection touch panels that require a transparent electrode, such as a surface capacitance method, a resistance film method, and an electromagnetic induction method, may be used.

  The display panel 30 is typically a liquid crystal display panel or an electroluminescence (EL) panel, but may be an electronic paper panel, a display device using a cathode ray tube, or various known display panels.

By using the display device 100 having the above-described configuration, wiring that is present in the outer peripheral portion of the position detection area of the touch panel or the outer peripheral portion of the display area of the display panel 30 is unnecessary for the display content itself. Various components such as the connector and the control circuit can be hidden to prevent the appearance from being damaged.
In addition, the white color expressed by the white resin layer 3 in the light shielding layer 2 of the front protective plate 10 for a display device is hardly yellowed, and a product with high designability is possible.

[Deformation as display device]
The display device 100 of the present invention can take other forms besides the above-described form. Some of these will be described below.

[Front protective plate 10 for display device with integrated touch panel function]
A structure in which a transparent electrode 6 for a touch panel to be integrated is composed of two layers of a first transparent electrode 6a and a second transparent electrode 6b that are insulated from each other, and these two layers are formed on different substrates. In such a case, one of these substrates is also used as the translucent substrate 1 of the front protective plate 10 for a display device, so that it is integrated with one transparent electrode, and the other transparent electrode and substrate are combined. The display device 100 can be configured by being incorporated as a touch panel constituent member separate from the front protection plate 10 for the display device and the display panel 30. What is necessary is just to select the structure suitable for various conditions, such as the manufacturing equipment which can be used, an assembly process, as what structure the front surface protection plate 10 for display apparatuses and a touch panel function are integrated.

  Even in such a configuration, since the touch panel function is integrated, the number of parts is reduced, the number of assembling steps is reduced, and the cost can be reduced. In addition, the white color expressed by the white resin layer 3 in the light shielding layer 2 of the front protective plate 10 for a display device is hardly yellowed, and a product with high designability is possible.

[Interposition of resin layer such as adhesive sheet]
In the display device 100 according to the embodiment illustrated in FIG. 10, the display device front protective plate 10 and the display panel 30 have a gap and an air layer. However, in the present invention, Between the front protective plate 10 for display device and the display panel 30, the space between the constituent members may be filled with a resin layer such as an adhesive layer. Since the light reflection on the surface of the member is reduced by the resin layer, the display can be more easily seen.

For the resin layer, a pressure-sensitive adhesive sheet, a solidified layer of the applied resin liquid, or the like can be used.
As the pressure-sensitive adhesive sheet, an optical grade sheet excellent in transparency is preferable, and as such a pressure-sensitive adhesive sheet, an acrylic pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, an epoxy-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, or the like is used. Can be used.

[D] Application:
Applications of the display device front protective plate 10 and the display device 100 according to the present invention are not particularly limited. For example, a mobile phone such as a smartphone, a portable information terminal such as a tablet PC, a personal computer, a car navigation system, a digital camera, an electronic notebook, a game machine, an automatic ticket vending machine, an ATM terminal, a POS terminal, and the like.

DESCRIPTION OF SYMBOLS 1 Translucent substrate 2 Light shielding layer 3 White resin layer 4 Oxygen blocking layer 5 Overcoat layer 5a First overcoat layer 5b Second overcoat layer 5c Third overcoat layer 6 Transparent electrode 6a First transparent Electrode 6b Second transparent electrode 7 Wiring 8 Backing layer 9 Visible information 9L Visible information forming layer 10 Front protective plate for display device 20 Touch panel 30 Display panel 40 Front protective plate for conventional display device 41 (Conventional) light shielding layer 100 Display Device 200 Conventional display device A1 Display area A2 Opaque area Bk Black layer S1 First surface S2 Second surface
V observer

Claims (2)

A method for manufacturing a front protective plate for a display device having a central display region and an opaque region that is provided on an outer periphery of the display region and shields visible light,
A white color is exhibited by having a white resin layer in the opaque region on any one of the first surface of the translucent substrate and the second surface opposite to the first surface. Producing a light shielding layer;
A transparent electrode provided on the one surface so as to extend from the display region to a portion of the opaque region having the light shielding layer, and the light shielding on the one surface with respect to the transparent electrode. Producing an opaque wiring provided to be electrically connected at a portion of the layer,
The white resin layer includes at least a white pigment in a resin binder made of a cured product of a curable resin,
The white resin layer has a lightness of 8.0 or more and a saturation of 2.0 or less in the Munsell color system.
The transparent electrode is made of the layer itself opaque conductive layer, at least the display region, made of a metallic conductive mesh ensuring through property by being formed into a mesh, capacitance type Configure the touch panel,
The transparent electrode is formed at a temperature of less than 200 ° C.
A method for manufacturing a front protective plate for a display device. The transparent electrode is composed of a first transparent electrode and a second transparent electrode that are insulated from each other and intersect each other,
When producing the transparent electrode, an overcoat layer that electrically insulates the first transparent electrode and the second transparent electrode from each other at their intersections is further produced,
The overcoat layer is formed at a temperature of less than 200 ° C.
The manufacturing method of the front surface protection plate for display apparatuses of Claim 1.