JPWO2014054592A1 - Transparent surface material with adhesive layer, method for producing the same, and display device - Google Patents

Abstract

Provided are a transparent surface material with an adhesive layer in which bubbles at the interface between an object to be bonded and an adhesive layer rapidly disappear, a method for producing the same, and a display device. A peelable protective film that covers a transparent face material, an adhesive layer formed on at least one surface of the transparent face material, and a surface of the adhesive layer opposite to the transparent face material side; The protective film has a pressure-sensitive adhesive layer-containing transparent surface material having an oxygen permeability of 100 cc / m 2 · day · atm or less.

Description

  The present invention relates to a transparent surface material with an adhesive layer that can be suitably used for protecting a display panel of a display device, a manufacturing method thereof, a display device, and a manufacturing method of a display device.

Conventionally, a transparent surface material (protective plate) that can be bonded to the display panel is used to protect the display panel of the display device.
The said transparent surface material has an adhesion layer for bonding with a display panel (to-be-bonded object), and this adhesive layer is provided as a transparent surface material with the adhesion layer covered with the protective film.
When bonding the display panel and the protective plate, the display panel and the protective plate are placed through the adhesive layer under a reduced pressure atmosphere so that no bubbles (voids) remain at the interface between the display panel and the adhesive layer. After pasting, the method of returning this to atmospheric pressure atmosphere may be taken (refer to patent documents 1 and patent documents 2).
According to this method, even if bubbles remain at the interface, the pressure difference between the pressure in the bubbles (depressurized state) and the pressure applied to the adhesive layer (atmospheric pressure) is returned to the atmospheric pressure atmosphere. Reduces the volume of the bubbles and the bubbles disappear.

International Publication No. 2012-0777726 International Publication No. 2012-0777727

However, in the conventional transparent surface material with an adhesive layer, it may take time for the bubbles (voids) remaining at the interface between the display panel (bonded object) and the adhesive layer to disappear. As a result of confirmation by the present inventors, it has been found that, particularly when the transparent surface material with the adhesive layer is stored for a long period of time, it takes a long time for the bubbles to disappear.
Then, this invention provides the transparent surface material with the adhesion layer from which the bubble of the interface of to-be-bonded object and an adhesion layer lose | disappears rapidly, its manufacturing method, a display apparatus, and the manufacturing method of a display apparatus.

The transparent face material with an adhesive layer of the present invention covers a transparent face material, an adhesive layer formed on at least one surface of the transparent face material, and a surface of the adhesive layer opposite to the transparent face material side. The protective film has an oxygen permeability of 100 cc / m ² · day · atm or less.
The protective film preferably has a gas barrier layer formed from a layer containing an inorganic compound.
The ten-point average roughness Rz of the surface of the protective film on the pressure-sensitive adhesive layer side is preferably 0.2 to 20 μm.
Moreover, it is preferable that the said transparent surface material is a protective plate of a display apparatus.

The method for producing a transparent surface material with an adhesive layer of the present invention comprises: a transparent surface material; an adhesive layer formed on one surface of the transparent surface material; and a surface opposite to the transparent surface material side of the adhesive layer. A method for producing a transparent surface material with an adhesive layer comprising a protective film that can be peeled, wherein the transparent surface material is a film having an oxygen permeability of 100 cc / m ² · day · atm or less as the protective film. After supplying the photocurable resin composition or the thermosetting resin composition on the top, in a reduced pressure atmosphere of 1 kPa or less, the protective film is in contact with the side of the transparent surface material to which the composition is supplied, Laminating the transparent face material through the composition to form a laminate, and then placing the laminate in a pressure atmosphere of 50 kPa or more to cure the photocurable resin composition or the thermosetting resin composition. Features.
After a protective film having an oxygen permeability of 100 cc / m ² · day · atm or less is attached to the support surface material, it may be laminated on the transparent surface material as described above to form a laminate.
In the above-described method for producing a transparent surface material with an adhesive layer, the protective film is formed of a support material having one surface abutting against the adhesive layer, and the other surface of the support material. It is preferable to have a gas barrier layer. Moreover, it is preferable that 10-point average roughness Rz of the surface at the side of the said adhesion layer of the said protective film is 0.2-20 micrometers.

  The display device of the present invention is a display device having a display panel and a transparent surface material bonded via a pressure-sensitive adhesive layer on the viewing-side surface of the display panel, wherein the transparent surface material and the pressure-sensitive adhesive layer are The protective film of the transparent surface material with an adhesive layer described above is peeled off.

  A method for manufacturing a display device according to the present invention is a method for manufacturing a display device having a display panel and a transparent surface material that is bonded to a surface on the viewing side of the display panel via an adhesive layer, the adhesive layer described above. Manufacturing method of bonding the display panel with the transparent surface material with the adhesive layer from which the protective film described above was peeled off after peeling off the protective film of the transparent surface material with the adhesive layer obtained by the manufacturing method of the transparent surface material with attachment It is.

  Even if the transparent surface material with an adhesive layer of the present invention is not used immediately after production, for example, after producing the transparent surface material with an adhesive layer, the surface of the display panel of the display device is manufactured for the production of the display device. Even when it does not immediately bond to the transparent surface material with the pressure-sensitive adhesive layer, the bubbles formed at the interface between the material to be bonded and the pressure-sensitive adhesive layer can be quickly extinguished when bonded to the material to be bonded.

It is sectional drawing which shows an example of the transparent surface material with the adhesion layer of this invention. It is sectional drawing which shows typically the 1st example of the protective film used for the transparent surface material with the adhesion layer of FIG. It is sectional drawing which shows the 2nd example of a protective film typically. It is sectional drawing which shows the 3rd example of a protective film typically. It is a top view explaining the manufacturing process goods obtained in the step of the manufacturing process (a) of the transparent surface material with an adhesion layer. It is sectional drawing explaining the manufacturing process goods obtained at the step of the manufacturing process (a) of the transparent surface material with an adhesion layer. It is a top view explaining the manufacturing process goods obtained in the step of the manufacturing process (b) of the transparent surface material with an adhesion layer. It is sectional drawing explaining the manufacturing process goods obtained in the step of the manufacturing process (b) of the transparent surface material with an adhesion layer. It is sectional drawing explaining the manufacturing process goods obtained in the step of the manufacturing process (c) of the transparent surface material with an adhesion layer. It is sectional drawing which shows the example of the display apparatus using the transparent surface material with the adhesion layer of FIG. It is a perspective view which shows the mode of the space | gap in the interface of a display panel and an adhesion layer at the time of bonding the transparent surface material with the adhesion layer from which the protective film was peeled off, and a display panel through the adhesion layer.

In this specification, “transparent” in the “transparent surface material” means that the surface material and the display surface of the display panel are bonded to each other without a gap through an adhesive layer, and then the whole or part of the display image of the display panel. Means a state that can be visually recognized through the face material without receiving optical distortion. Therefore, even if part of the light incident on the face material from the display panel is absorbed and reflected by the face material, or the visible material has a low visible ray transmittance due to a change in optical phase, the surface If the display image on the display panel can be viewed through the material without optical distortion, it can be said to be “transparent”.
“(Meth) acrylate” means acrylate or methacrylate.

<Transparent surface material with adhesive layer>
FIG. 1 is a cross-sectional view showing an example of a transparent surface material with an adhesive layer of the present invention.
The transparent surface material 1 with an adhesive layer includes a protective plate 10 (that is, a transparent surface material), a light shielding printing portion 12 (light shielding portion) formed in a frame shape on the periphery of the surface of the protection plate 10, and a light shielding printing portion 12. Has a pressure-sensitive adhesive layer 14 formed on the surface of the protective plate 10 on the side on which is formed, and a peelable protective film 16 (protective material) that covers the surface of the pressure-sensitive adhesive layer 14. Reference numeral 13 denotes a light-transmitting portion that is an area surrounded by the light-shielding printing portion 12.
The transparent surface material 1 with an adhesive layer can manufacture a display apparatus by peeling the protective film 16 and bonding with a display panel.
Although FIG. 1 illustrates the case where the adhesive layer 14 is formed on one side of the transparent surface material 1, the adhesive layer 14 may be formed on both surfaces of the transparent surface material 1. The surface of the adhesive layer is also covered with a peelable protective film 16.

(Protective plate)
The protection plate 10 (that is, the transparent surface material) is provided on the image display surface side (viewing side) of the display panel described later to protect the display panel. Examples of the protective plate 10 include a glass plate or a transparent resin plate. The glass plate is not only highly transparent with respect to light emitted from and reflected from the display panel, but also has light resistance, low birefringence, high planar accuracy, surface scratch resistance, and high mechanical strength. Is most preferred.
A glass plate is also preferred from the viewpoint of sufficiently transmitting light for curing the photocurable resin composition in the production process described later.

  Examples of the material of the glass plate include glass materials such as soda lime glass, and high transmittance glass (also referred to as white plate glass) having lower iron content and less bluishness is more preferable. In order to improve safety, tempered glass may be used as the protective plate 10. In particular, when a thin glass plate is used, it is preferable to use a chemically strengthened glass plate. Examples of the material of the transparent resin plate include highly transparent resin materials (such as polycarbonate and polymethyl methacrylate).

  The protective plate 10 may be subjected to a surface treatment in order to improve the interfacial adhesive force with the adhesive layer 14. Examples of the surface treatment include a method of treating the surface of the protective plate 10 with a silane coupling agent, a method of forming a silicon oxide thin film by an oxidation flame using a frame burner, and the like.

  In order to increase the contrast of the display image, the protective plate 10 may be provided with an antireflection layer on the surface opposite to the side on which the adhesive layer 14 is formed. Further, depending on the purpose, a part or the whole of the protective plate 10 is colored, or a part or the whole of the surface of the protective plate 10 is polished to form a glass to scatter light, or a part of the surface of the protective plate 10 Alternatively, the transmitted light may be refracted or reflected by forming fine irregularities on the entire surface. Further, a colored film, a light scattering film, a photorefractive film, a light reflecting film, or the like may be attached to a part or the whole of the surface of the protective plate 10.

The shape of the protective plate 10 is preferably rectangular in order to match the outer shape of the display device.
Depending on the outer shape of the display device, a protective plate that covers the entire display surface of the display panel and has a curved shape in the outer shape can be used.
What is necessary is just to set the magnitude | size of the protective plate 10 suitably according to the external shape of a display apparatus. From the viewpoint of mechanical strength and transparency, the thickness of the protective plate 10 is preferably 0.5 to 25 mm in the case of a glass plate. In applications such as television receivers and PC displays used indoors, 1 to 6 mm is preferable from the viewpoint of weight reduction of the display device, and 3 to 20 mm is preferable in public display applications installed outdoors. When chemically strengthened glass is used, the thickness of the glass is preferably about 0.5 to 1.5 mm in terms of strength. In the case of a transparent resin plate, 2 to 10 mm is preferable.

(Shading printing part)
The light-shielding printing unit 12 hides wiring members and the like connected to the display panel so that areas other than the image display area of the display panel, which will be described later, are not visible from the protective plate 10 side. The light-shielding printing unit 12 can be formed on the surface on which the adhesive layer 14 is formed or on the opposite surface. In terms of reducing the parallax between the light-shielding printing unit 12 and the image display area, it is preferable to form the surface on the side where the adhesive layer 14 is formed. When the protective plate 10 is a glass plate, it is preferable to use a ceramic printing ink containing a black pigment for the light shielding printing portion 12 because of high light shielding properties.
When the wiring member of the display panel has a structure that cannot be seen from the side of the display panel, or is concealed by another member such as a casing of the display device, or the object to be bonded other than the display panel and protection In the case where the transparent surface material 1 with the pressure-sensitive adhesive layer from which the film has been peeled off is bonded, the light-shielding print portion 12 may not be formed on the protective plate 10.

(Adhesive layer)
The adhesive layer 14 includes a layered portion 18 that extends along the surface of the protective plate 10 and a weir-shaped portion 20 that surrounds the layered portion 18 in a form in contact with the periphery of the layered portion 18. By having the weir-like portion 20 in the pressure-sensitive adhesive layer 14, it is possible to prevent the peripheral portion of the layer-like portion 18 from spreading outward and to reduce the thickness of the peripheral portion, and to keep the entire thickness of the layer-like portion 18 uniform. it can. By making the entire thickness of the layered portion 18 uniform, it is preferable to easily suppress a void from remaining at the interface in bonding with another face material (that is, an object to be bonded).

It is preferable that the upper surface 14a on the protective film 16 side of the adhesive layer 14 has a rough surface structure that follows the rough surface structure of the lower surface 16a on the adhesive layer 14 side in the protective film 16 described later. That is, it is preferable to form the adhesive layer 14 so that the shape of the surface 16a in contact with the adhesive layer of the protective film described later can be transferred to the adhesive layer.
When the upper surface 14a has a rough surface structure that is substantially the same as or close to the surface roughness (Rz, Ra) of the surface of the protective film 16a described later, the object to be bonded and the adhesive layer are bonded to each other when bonded to the object to be bonded. The bubbles formed at the interface can be quickly extinguished. In addition, the action mechanism considered as a reason for obtaining such an effect will be described later.
An adhesive layer having a sufficiently small elastic modulus may be used in order to quickly eliminate bubbles at the time of bonding, and the surface roughness of the 14a surface of the adhesive layer is determined by the method specified in JIS B0601 (2001) described later. It may be difficult to measure the height directly.

In the adhesive layer 14, the thickness of the dam-like portion 20 may be slightly thicker than the thickness of the layered portion 18, in that a void open to the outside is less likely to occur when the display panel and the transparent surface material with the adhesive layer are bonded. Although it is preferable, it is not this limitation. When the thickness of the dam-like part 20 is thicker, it is more preferable that the difference between the thickness of the dam-like part 20 and the thickness of the layered part 18 does not exceed 20 μm. Even if the surface of the layer-shaped portion 18 is not flat and the thickness of the layer-shaped portion 18 is not constant, the thickness of the weir-shaped portion 20 is at least part of the region where the weir-shaped portion 20 is adjacent to the layer-shaped portion 18. It is preferable that the thickness is slightly larger than the thickness of the layered portion 18.
Moreover, when the thickness of the dam-like portion 20 is thicker than the thickness of the layered portion 18, even when a gap remains at the interface with the display panel at the peripheral edge of the adhesive layer 14 when pasting to the display panel. Since the gap is blocked by the weir-like portion 20, the gap is not opened to the outside and becomes an independent gap. Therefore, after bonding the transparent surface material 1 with the adhesive layer to the display panel in a reduced pressure atmosphere and then returning it to the atmospheric pressure atmosphere, the pressure in the gap (that is, the pressure in the reduced pressure state) and the adhesive The volume of the voids is reduced by the pressure difference from the pressure applied to the layer 14 (that is, atmospheric pressure), and the voids tend to disappear quickly.

(Layered part)
The layered portion 18 is a layer made of a transparent resin obtained by curing a liquid curable resin composition for forming a layered portion (hereinafter referred to as a first composition).

The shear modulus at 25 ° C. of the layered portion 18 is preferably 10 ³ to 10 ⁷ Pa, and more preferably 10 ⁴ to 10 ⁶ Pa. Furthermore, 10 ⁴ to 10 ⁵ Pa is particularly preferable in order to eliminate the gap at the time of bonding in a shorter time. If the shear modulus is 10 ³ Pa or more, the shape of the layered portion 18 can be maintained. Moreover, even when the thickness of the layered portion 18 is relatively thick, the thickness can be maintained uniformly throughout the layered portion 18, and when the transparent surface material 1 with the adhesive layer and the display panel are bonded, a display is performed. It is difficult for voids to occur at the interface between the panel and the adhesive layer 14. Moreover, when the shear modulus is 10 ⁴ Pa or more, it is easy to suppress deformation of the layered portion when a protective film described later is peeled off.
If the shear modulus is 10 ⁷ Pa or less, the layered portion 18 can exhibit good adhesion when bonded to a display panel. Moreover, since the molecular mobility of the resin material forming the layered portion 18 is relatively high, after bonding the display panel and the transparent surface material 1 with the adhesive layer in a reduced-pressure atmosphere, this is returned to the atmospheric pressure atmosphere. The volume of the void is likely to decrease due to the pressure difference between the pressure in the void (pressure in a state of reduced pressure) and the pressure applied to the layered portion 18 (that is, atmospheric pressure), and the volume has decreased. The gas in the gap is easily dissolved in the layered portion 18 and absorbed.

  The thickness of the layered portion 18 is preferably 0.03 to 2 mm, and more preferably 0.1 to 0.8 mm. If the thickness of the layered portion 18 is 0.03 mm or more, the layered portion 18 can effectively buffer an impact caused by an external force from the protective plate 10 side, and the display panel can be protected. Moreover, in the manufacturing method of the display apparatus of this embodiment, even if the foreign material which does not exceed the thickness of the layered part 18 mixes between the display panel and the transparent surface material 1 with the adhesion layer, the thickness of the layered part 18 is reduced. There is little influence on the light transmission performance without much change. If the thickness of the layered portion 18 is 2 mm or less, it is difficult for voids to remain in the layered portion 18, and the entire thickness of the display device does not become unnecessarily thick. As a method of adjusting the thickness of the layered portion 18, a method of adjusting the thickness of the weir-shaped portion 20 and adjusting the supply amount of the liquid first composition supplied to the surface of the protective plate 10, or a liquid And a method of adjusting the shrinkage ratio during curing of the first composition.

(Weir)
The dam member 20 is made of a transparent resin formed by applying and curing a liquid curable resin composition for forming a dam member (hereinafter referred to as a second composition). Since the area outside the image display area of the display panel is relatively narrow, the width of the weir 20 is preferably narrow. The width of the weir 20 is preferably 0.5 to 2 mm, and more preferably 0.8 to 1.6 mm. Further, the thickness of the dam-like portion 20 is substantially equal to the average thickness of the layer-like portion excluding the region where the dam-like portion and the layer-like portion are close to each other, or, as described above, 0.0. The thickness is preferably 005 to 0.05 mm, more preferably 0.01 to 0.03 mm.

The shear elastic modulus at 25 ° C. of the weir-shaped portion 20 is preferably larger than the shear elastic modulus at 25 ° C. of the layered portion 18. If the shear elastic modulus of the weir-like part 20 is larger than the shear elastic modulus of the layered part 18, the display panel is attached to the peripheral part of the adhesive layer 14 when the display panel and the transparent surface material 1 with the adhesive layer are bonded. Even if voids remain at the interface between the adhesive layer 14 and the adhesive layer 14, the voids are not easily opened to the outside, and are easily formed as independent voids. Therefore, after pasting the display panel and the transparent surface material 1 with the adhesive layer in a reduced pressure atmosphere, when the pressure is returned to the atmospheric pressure atmosphere, the pressure in the gap (that is, the pressure in the reduced pressure state). ) And the pressure applied to the pressure-sensitive adhesive layer 14 (that is, atmospheric pressure), the volume of the void is reduced and the void is likely to disappear.
Further, the thickness of the dam-like portion is determined in at least a part of the region where the dam-like portion 20 is adjacent to the layer-like portion 18 by making the shear modulus of the dam-like portion 20 larger than the shear elastic modulus of the layer-like portion 18. However, it becomes easy to manufacture the transparent surface material 1 with the adhesion layer which is slightly larger than the thickness of the layered portion.
As a method of adjusting the thickness of the weir 20, a method of adjusting the supply amount of the second composition for forming the weir 10 supplied to the surface of the protective plate 10, or the viscosity and curing of the second composition For example, a method of adjusting the shrinkage rate at the time may be mentioned.

  As will be described later, since the protective film 16 having a high gas barrier property is used for the transparent face material 1 with the adhesive layer, outside air (for example, oxygen, nitrogen, water vapor, etc.) permeates the protective film 16 during storage. Thus, mixing and dissolution in the adhesive layer 14 can be suppressed.

(Protective film)
(First example)
The protective film 16 protects the surface of the pressure-sensitive adhesive layer 14 and maintains the shape of the pressure-sensitive adhesive layer 14 until immediately before the transparent surface material 1 with the pressure-sensitive adhesive layer is bonded to the display panel.
FIG. 2 is a cross-sectional view schematically showing a protective film 16 </ b> A that is a first example of the protective film 16.
16 A of protective films are the 1st support material 3, the barrier layer 4 (namely, gas barrier layer) formed in the whole upper surface 3a, the 2nd support material 5 laminated | stacked on the upper surface 4a of the barrier layer 4, A third support member 7 laminated on the upper surface 5 a of the second support member 5 via the adhesive layer 6 and a slightly adhesive layer 8 formed on the upper surface 7 a of the third support member 7 are provided.

The first support material 3 is used by bringing the lower surface 3b into contact with the adhesive layer 14, and is preferably a film made of a resin such as polyethylene, polypropylene, or a fluorine resin. In particular, use of a polyolefin-based resin (polyethylene, polypropylene, etc.) is preferable because peeling from the adhesive layer 14 becomes easy.
Although the suitable thickness of the 1st support material 3 changes with materials, when using comparatively flexible films, such as polyethylene and a polypropylene, 0.02-0.2 mm is preferable. When the thickness is 0.02 mm or more, excessive deformation of the protective film 16A can be suppressed when the protective film 16A is peeled from the adhesive layer 14. If the thickness of the protective film 16A is 0.2 mm or less, the protective film 16A is easily bent at the time of peeling, and the peeling operation can be facilitated.

On the lower surface 3b of the first support material 3, when the adhesive layer 14 is easily peeled off, or when bonded to the display panel, voids formed at the interface between the display panel and the adhesive layer are rapidly disappeared. Therefore, the surface may be roughened. At this time, it is preferable that the lower surface 3b has a rough surface structure in which the ten-point average roughness Rz defined in JIS B0601 (2001) is 2.0 to 20 μm.
The ten-point average roughness Rz of the lower surface 3b is more preferably 2.0 to 10 μm, and further preferably 2.0 to 6 μm. Since the lower surface 3b has a rough surface structure having Rz in the above-described range, the upper surface of the adhesive layer 14 on the protective film 16 side can be easily formed into a rough surface structure following the rough surface structure of the lower surface 3b. Moreover, it is preferable that arithmetic mean roughness Ra of the lower surface 3b is 0.2-1.0 micrometer.

By bonding another layer capable of forming a rough surface structure to the lower surface 3b of the first support member 3, the rough surface structure can be provided on the surface opposite to the slightly adhesive layer 8 of the protective film 16A. For example, it is preferable to form a rough surface structure on the lower surface 3b of the first support material 3 made of polypropylene by a polymer blend layer made of polypropylene and polyethylene, both of which are polyolefin-based, because peeling from the adhesive layer is easy.
Further, a back layer can be provided on the lower surface 3b to facilitate peeling from the adhesive layer.
For the back layer, it is preferable to use a film having relatively low adhesion, such as polyethylene, polypropylene, and fluorine resin. In order to facilitate peeling, a release agent such as silicone may be applied to the lower surface 3b or the back layer as long as the adhesive layer 14 is not adversely affected.

The gas barrier layer 4 is a layer that prevents gas (for example, oxygen gas, nitrogen gas, water vapor, etc.) from the outside from passing through the protective film 16 and entering the adhesive layer 14, and is a low gas permeable material. Preferably it consists of. The gas permeability can be used as a measure by measuring “oxygen permeability” according to the standard of JIS K 7126.
The “oxygen permeability” of the protective film 16 on which the gas barrier layer 4 is formed is preferably 100 cc / m ² · day · atm or less. Thus, after the transparent surface material 1 with the adhesive layer is manufactured and before it is used, that is, after the transparent surface material with the adhesive layer is manufactured, the display of the display device is manufactured for manufacturing the display device. It is possible to prevent outside air from passing through the protective film 16 and being mixed into the adhesive layer 14 until the panel is bonded to the transparent surface material with the adhesive layer.

The material of the gas barrier layer 4 is not particularly limited as long as a predetermined oxygen permeability is obtained. For example, the gas barrier layer 4 depends on inorganic compounds such as oxides, nitrides, sulfides, carbides, clay-based materials, inorganic compounds, or clay and resin. A complex or the like is preferred.
Specifically, silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), silicon nitride, silicon oxynitride, aluminum oxynitride, magnesium oxide, zinc oxide, indium oxide, tin oxide, and layered silicate clay Examples thereof include crystals, and silicon oxide (SiO ₂ ) and aluminum oxide (Al ₂ O ₃ ) are particularly preferable.

  If the thickness of the gas barrier layer 4 is 0.01 μm or more (for example, 0.02 to 2 μm), the gas barrier property can be improved, which is preferable.

The second support material 5 and the third support material 7 are preferably films made of a polyester resin excellent in gas barrier properties, particularly polyethylene terephthalate (hereinafter referred to as PET). As the polyester resin, polyethylene naphthalate (PEN) can be used in addition to PET.
In addition, polyamide resins such as nylon-6 and nylon-66 can also be used. Polyvinyl alcohol may also be used.

  The thickness of the second support material 5 and the third support material 7 is preferably 5 to 50 μm when a film made of a polyester-based resin such as PET is used. If this thickness is 5 μm or more, the gas barrier property can be improved, and if it is 50 μm or less, the protective film 16 is easily bent at the time of peeling, and the peeling operation can be facilitated.

  For the adhesive layer 6 (which may be a pressure-sensitive adhesive layer), acrylic, rubber-based, silicone-based, urethane-based adhesives and pressure-sensitive adhesives can be used.

The slightly adhesive layer 8 is used to attach the protective film 16A to the support surface material 10 described later in a peelable manner, and it is possible to use ethylene vinyl acetate, acrylic resin, styrene resin or the like as the adhesive layer. An ethylene vinyl acetate resin that can be made and exhibits self-adhesiveness is preferred. When polyprolene or the like is used for the first support material 3 to be described later, it is preferable that the ethylene vinyl acetate resin can be integrally formed with the first support material 3 by a molding method such as a co-extrusion method.
Since the slightly adhesive layer 8 is peeled after being adhered to the support surface material 10 in the production of the transparent surface material with an adhesive layer 1 of the present invention, the adhesive force is weaker than that of the adhesive layer 14.
The adhesive strength of the adhesive surface of the slightly adhesive layer 8 is preferably 0.02 to 0.2 N in a 25 mm wide test body in a 180 ° peeling test at a peeling speed of 300 mm / min with respect to the acrylic plate, and is 0.04 to 0.00. 1N is more preferable. When the adhesive strength is 0.02 N or more, it is possible to adhere to the support surface material 10, and when it is 0.2 N or less, it is easy to peel the protective film 16 from the support surface material 10.
The support surface material 10 is used to hold the protective film 16A in the process of overlaying and adhering the protective film 16A to the adhesive layer 14 in the display device manufacturing method described later.

The “oxygen permeability” of the protective film 16 is 100 cc / m ² · day · atm or less, preferably 10 cc / m ² · day · atm or less. Thereby, after this transparent surface material 1 with an adhesion layer is manufactured, until it is used for bonding with a to-be-bonded body, outside air permeate | transmits the protective film 16 and mixes into the adhesion layer 14. Can be prevented. The oxygen permeability of the protective film 16 can be measured using a gas permeation measuring device K-315-N (corresponding to JIS K7126) of TRS Tsukuba Riseki Co., Ltd. in an environment of 25 ° C. using O ₂ gas.

As will be described later, when the pressure-sensitive adhesive layer 14 is formed of a photocurable composition and is formed by irradiating ultraviolet light, short wavelength visible light, or the like through the protective film 16 to cure the photocurable resin composition, The protective film 16 needs to have sufficient transparency with respect to the wavelength of light irradiated in a state where it is in contact with the adhesive layer 14.
In this case, it is preferable that the transmittance | permeability of the ultraviolet-ray (wavelength 360nm) of a protective film is 50% or more.

  On the other hand, the pressure-sensitive adhesive layer 14 can also be formed from a thermosetting composition or the like. In this case, it is not necessary to irradiate light through the protective film 16, so that the protective film 16 has a low light-transmitting protective material (for example, You may use the thing which has foil materials consisting of metals, such as aluminum.

The protective film 16A can be produced, for example, by the following method.
The upper surface 3a of the first support material 3 is laminated on the second support material 5 on which the barrier layer 4 is formed by thermal fusion or the like, and the third support material 7 on which the slightly adhesive layer 8 is formed on the upper surface 7a is bonded to the adhesive layer. The protective film 16A shown in FIG.
The formation method of the barrier layer 4 is not particularly limited, and can be formed on the surface of the second support material 5 or the first support material 3 by vapor deposition, sputtering method, plasma CVD method, sol-gel method, wet method, or the like.
Further, if a transparent conductive layer is formed between the third support material 7 and the slightly adhesive layer 8, that is, the upper surface 7a, and a part of the protective film is left on the transparent surface material with the adhesive layer and bonded to the display panel, In the case where a conductive layer is formed on the surface of the display panel that is visible like an IPS mode display panel, it is preferable to easily connect the conductive layer to the conductive layer.

(Second example)
FIG. 3 is a cross-sectional view schematically showing a protective film 16 </ b> B that is a second example of the protective film 16. In the following description, parts common to the protective film 16A of the first example are denoted by the same reference numerals and description thereof is omitted.
The protective film 16B is formed on the first support member 3, the barrier layer 4 formed on the upper surface 3a thereof, the second support member 5 laminated on the upper surface 4a of the barrier layer 4, and the upper surface 5a of the second support member 5. And the formed slightly adhesive layer 8.
The protective film 16B can be produced, for example, by the following method.
The second support material 5 on which the barrier layer 4 is formed is laminated on the upper surface 3a of the first support material 3 by heat fusion or the like, and the slight adhesion layer 8 is formed on the upper surface 5a of the second support material 5 to protect the second support material 5. Film 16B is obtained.

(Third example)
FIG. 4 is a cross-sectional view schematically showing a protective film 16 </ b> C that is a third example of the protective film 16.
The protective film 16 </ b> C includes the first support material 3, the barrier layer 4 formed on the upper surface 3 a, and the slightly adhesive layer 8 formed on the upper surface 4 a of the barrier layer 4.
The protective film 16C can be produced, for example, by the following method.
The protective film 16C is obtained by forming the slightly adhesive layer 8 on the upper surface 4a of the barrier layer 4 formed on the upper surface 3a of the first support material 3.

[Method for producing transparent surface material with adhesive layer]
The manufacturing method of the transparent surface material with the adhesion layer of this embodiment is a method which has the following process (a)-(e) in this order.
(A) The process of apply | coating a liquid 2nd composition to the peripheral part of the surface of a transparent surface material, and forming a non-hardened or semi-hardened dam-like part.
(B) The process of supplying a liquid 1st composition to the area | region enclosed by the weir-like part.
(C) In a reduced pressure atmosphere of 1 kPa or less, a support surface material on which a protective film is attached is stacked on the first composition so that the protective film is in contact with the first composition, The process of obtaining the laminated body by which the uncured layered part which consists of a 1st composition was sealed with the protective film and the dam-like part.
(D) A step of curing the uncured layered portion in a state where the laminate is placed under a pressure atmosphere of 50 kPa or more to form an adhesive layer having the layered portion and the weir-shaped portion.
(E) The process of peeling a support surface material from a protective film.

Hereinafter, step (a) to step (e) will be described in detail.
(Process (a))
First, a liquid-like 2nd composition is apply | coated to the peripheral part of the surface of a transparent surface material, and a dam-like part is formed.
The application is performed using a printing machine, a dispenser, or the like. The weir-like portion may be in an uncured state or in a partially cured state that is partially cured. When the second composition is a photocurable composition, partial weir-like curing is performed by light irradiation. For example, the photocurable resin composition is partially cured by irradiating ultraviolet light or visible light having a short wavelength from a light source (ultraviolet lamp, high pressure mercury lamp, UV-LED, etc.).

The viscosity of the second composition is preferably 500 to 3000 Pa · s, more preferably 800 to 2500 Pa · s, and still more preferably 1000 to 2000 Pa · s. If the viscosity is 500 Pa · s or more, the shape of the uncured weir can be maintained for a relatively long time, and the height of the uncured weir can be sufficiently maintained. If the viscosity is 3000 Pa · s or less, an uncured weir can be formed by coating.
In addition, even when the viscosity of the second composition forming the weir-like portion is less than 500 Pa · s, if the second composition is a photocurable composition, light is applied immediately after the application. The viscosity of the second composition after the light irradiation may be set to the above-described preferable range. From the viewpoint of ease of application, the viscosity at the time of application of the second composition is preferably 500 Pa · s or less, and more preferably 200 Pa · s or less.
In addition, the viscosity of a 2nd composition and the 1st composition mentioned later in this specification says what was measured using the E-type viscosity meter at 25 degreeC.

  The second composition may be a photocurable resin composition or a thermosetting resin composition. As the second composition, it can be cured at a low temperature and has a high curing rate, and the second composition having a low viscosity can be increased in viscosity by light irradiation immediately after coating, so that the curable compound and the photopolymerization initiator ( A photocurable resin composition containing C) is preferred.

  As a 2nd composition, since it is easy to adjust a viscosity to the said range, as said curable compound, it has 1 or more types of the oligomer (A) which has a sclerosing | hardenable group and whose number average molecular weight is 30,000-100000. And a monomer (B) having a curable group and a molecular weight of 125 to 600, and the ratio of the monomer (B) is the sum of the oligomer (A) and the monomer (B) (100 %) Is preferably 15 to 50% by mass. When the viscosity is adjusted to the above range by light irradiation immediately after coating, the proportion of the monomer (B) is 30 to 70 in the total (100% by mass) of the oligomer (A) and the monomer (B). What is mass% is preferable.

Examples of the curable group of the oligomer (A) include addition polymerizable unsaturated groups (acryloyloxy group, methacryloyloxy group, etc.) or combinations of unsaturated groups and thiol groups. A group selected from an acryloyloxy group and a methacryloyloxy group is preferable from the viewpoint that a curing rate is high and a highly transparent weir-like part is obtained.
As the oligomer (A), those having an average of 1.8 to 4 curable groups per molecule from the viewpoint of curability of the photocurable resin composition for forming the weir-like part and mechanical properties of the weir-like part. preferable. Examples of the oligomer (A) include urethane oligomers having a urethane bond, poly (meth) acrylates of polyoxyalkylene polyols, poly (meth) acrylates of polyester polyols, and the like after curing by molecular design of urethane chains. The urethane oligomer (A1) is preferable from the viewpoint that the mechanical properties of the resin, the adhesiveness to the transparent surface material or the display panel can be adjusted widely. One or more oligomers (A) may be used.

Examples of the curable group of the monomer (B) include addition polymerizable unsaturated groups (acryloyloxy group, methacryloyloxy group and the like), a combination of an unsaturated group and a thiol group, and the like. A group selected from an acryloyloxy group and a methacryloyloxy group is preferable from the viewpoint that a curing rate is high and a highly transparent weir-like part is obtained.
The monomer (B) preferably contains a monomer (B3) having a hydroxyl group from the viewpoint of adhesion between the transparent surface material or the display panel and the weir-like part and solubility of various additives described later. Specifically, the hydroxyl group-containing monomer (B3) includes a hydroxy acrylate having a hydroxyalkyl group having 1 to 2 hydroxyl groups and 3 to 8 carbon atoms, or hydroxymethacrylate (2-hydroxypropyl acrylate, 2-hydroxy). Butyl acrylate, 4-hydroxybutyl acrylate, 6-hydroxyhexyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl methacrylate, etc.), preferably 4-hydroxybutyl acrylate, or 2-hydroxybutyl methacrylate is particularly preferred. Monomer (B) may be used alone or in combination of two or more.

  Examples of the photopolymerization initiator (C) include acetophenone series, ketal series, benzoin or benzoin ether series, phosphine oxide series, benzophenone series, thioxanthone series, and quinone series. By using two or more kinds of photopolymerization initiators (C) having different absorption wavelength ranges in combination, the curing time can be further increased, or the surface curability of the weir-like portion can be increased. When adjusting the viscosity of the second resin composition to the above preferred range by light irradiation immediately after coating, it is particularly preferred to use two or more photopolymerization initiators (C) having different absorption wavelength ranges in combination.

(Process (b))
After the step (a), the liquid first composition is supplied to a region surrounded by the weir-shaped portion.
The supply amount of the first composition is such that a space formed by the weir-shaped portion, the transparent surface material, and the protective film is filled with the first composition, and the space between the transparent surface material and the protective film is a predetermined interval ( That is, the amount is set in advance so that the layered portion has a predetermined thickness. At this time, it is preferable to consider in advance volume reduction due to cure shrinkage of the first composition. Therefore, the amount is preferably such that the thickness of the supplied liquid first composition is slightly thicker than the predetermined thickness of the layered portion formed by curing.
Examples of the supply method include a method in which a transparent surface material is placed flat and is supplied in a dot shape, a linear shape, or a planar shape by a supply means such as a dispenser or a die coater.

The viscosity of the first composition is preferably 0.05 to 50 Pa · s, more preferably 1 to 20 Pa · s. When the viscosity is 0.05 Pa · s or more, the proportion of the monomer (B ′) described later can be suppressed, and the decrease in physical properties of the layered portion can be suppressed. Moreover, since the component having a low boiling point is reduced, volatilization in a reduced-pressure atmosphere described later is suppressed, which is preferable. If the viscosity is 50 Pa · s or less, voids hardly remain in the layered portion.
The viscosity of the first composition is measured using an E-type viscometer at 25 ° C.

  The first composition may be a photocurable resin composition or a thermosetting resin composition. As the first composition, a photocurable resin composition containing a curable compound and a photopolymerization initiator (C ′) is preferable because it can be cured at a low temperature and has a high curing rate.

  As a 1st composition, it is 1 or more types of the oligomer (A ') which has a sclerosing | hardenable group and whose number average molecular weight is 1000-100000 from the point which adjusts a viscosity to the said range easily. And one or more monomers (B ′) having a curable group and a molecular weight of 125 to 600, the ratio of the monomer (B ′) being the oligomer (A ′) and the monomer (B ′) And the total (100% by mass) is preferably 40 to 80% by mass.

  Examples of the curable group of the oligomer (A ′) include addition polymerizable unsaturated groups (acryloyloxy group, methacryloyloxy group, etc.), or a combination of an unsaturated group and a thiol group. And the group chosen from an acryloyloxy group and a methacryloyloxy group from the point from which a highly transparent layered part is obtained is preferable.

Examples of the curable group of the monomer (B ′) include addition-polymerizable unsaturated groups (acryloyloxy group, methacryloyloxy group, etc.) or combinations of unsaturated groups and thiol groups. And the group chosen from an acryloyloxy group and a methacryloyloxy group from the point from which a highly transparent layered part is obtained is preferable.
As the monomer (B ′), one having 1 to 3 curable groups per molecule is preferable from the viewpoint of the curability of the layered portion-forming photocurable resin composition and the mechanical properties of the layered portion.

  Examples of the photopolymerization initiator (C ′) include acetophenone series, ketal series, benzoin or benzoin ether series, phosphine oxide series, benzophenone series, thioxanthone series, and quinone series.

(Process (c))
After the step (b), the transparent surface material supplied with the first composition is put into a decompression device, and the transparent surface material is placed so that the surface of the first composition is on the fixed support disk in the decompression device. Lay flat.
A movement support mechanism that can move in the vertical direction is provided in the upper part of the decompression device, and a support surface material (for example, a glass plate) is attached to the movement support mechanism. A protective film is attached to the lower surface of the support surface material. When the protective film has a concavo-convex structure, the surface having the concavo-convex structure of the protective film is stuck so as to face the surface supplied with the first composition.
The supporting face material is placed at a position above the transparent face material and not in contact with the first composition. That is, the first composition on the transparent surface material and the protective film adhered to the surface of the support surface material are opposed to each other without being brought into contact with each other.

  After disposing the transparent surface material and the support surface material at predetermined positions, the inside of the pressure reducing device is depressurized to form a predetermined reduced pressure atmosphere. After the inside of the decompression device becomes a predetermined decompressed atmosphere, the support surface material supported by the moving support mechanism is moved downward, and the protective film is adhered on the first composition on the transparent surface material. The support surface materials thus overlapped so that the surface of the protective film is in contact with the first composition. Hereinafter, this superposition is referred to as a laminate.

By the overlapping, the first composition is sealed in the space surrounded by the surface of the transparent surface material, the surface of the protective film adhered to the support surface material, and the weir-like portion.
At the time of superposition, the first composition is expanded by the weight of the support surface material, the pressure from the moving support mechanism, etc., the first composition fills the space, and an uncured layered portion is formed. . Thereafter, when exposed to a high-pressure atmosphere in step (d), an uncured layered portion with few or no voids is formed.

  The reduced pressure atmosphere at the time of superposition is 1 kPa or less, preferably 10 to 300 Pa, and more preferably 15 to 100 Pa. If the reduced-pressure atmosphere is extremely low pressure, each component (curable compound, photopolymerization initiator, polymerization inhibitor, chain transfer agent, light stabilizer, etc.) contained in the first composition may be adversely affected. For example, if the reduced-pressure atmosphere is extremely low pressure, each component may be vaporized, and it may take time to provide the reduced-pressure atmosphere.

  The time from when the transparent surface material and the support surface material are overlapped to the time when the reduced pressure atmosphere is released is not particularly limited, and the reduced pressure atmosphere may be released immediately after sealing the first composition. After sealing the object, the reduced pressure state may be maintained for a predetermined time.

(Process (d))
After releasing the reduced pressure atmosphere in the step (c), the laminate is placed in a pressure atmosphere having an atmospheric pressure of 50 kPa or more.
When the laminated body is placed in a pressure atmosphere of 50 kPa or more, the transparent surface material and the support surface material are pressed in a direction in close contact with the increased pressure. Therefore, if there is a void in the sealed space in the laminate, the uncured layered portion flows in the void, and the entire sealed space is uniformly filled with the uncured layered portion.

  The time from when the laminate is placed in a pressure atmosphere of 50 kPa or more to the start of curing of the uncured layered portion (hereinafter referred to as high pressure holding time) is not particularly limited. When the process from taking out the laminated body from the decompression device to the curing device and starting the curing is performed under an atmospheric pressure atmosphere, the time required for the process becomes the high pressure holding time. Therefore, if there are no voids already in the sealed space of the laminate when placed in an atmospheric pressure atmosphere, or if the voids disappear during the process, the uncured layered part can be cured immediately. it can. When it takes time for the voids to disappear, the laminate is held in an atmosphere at a pressure of 50 kPa or more until the voids disappear. In addition, since there is usually no problem even if the high pressure holding time is increased, the high pressure holding time may be increased due to other necessity in the process. The high-pressure holding time may be a long time of one day or longer, but is preferably within 6 hours from the viewpoint of production efficiency, more preferably within 1 hour, and particularly within 10 minutes from the viewpoint of further increasing production efficiency. preferable.

  Next, an uncured layered portion and an uncured or semi-cured weir-shaped portion are cured to form an adhesive layer having the layered portion and the weir-shaped portion. At this time, the uncured or semi-cured weir-shaped portion may be cured simultaneously with the curing of the uncured layered portion, or may be cured in advance before the uncured layered portion is cured.

  When the uncured layered portion and the uncured or semi-cured weir-shaped portion are made of a photocurable composition, they are cured by irradiation with light. For example, the photocurable resin composition is cured by irradiating ultraviolet light or short wavelength visible light from a light source (ultraviolet lamp, high pressure mercury lamp, UV-LED, etc.). When a light-shielding printing part is formed on the peripheral edge of the transparent surface material, or a transparent resin film on which an antireflection layer is provided on the transparent surface material and an antireflection layer is formed, or the antireflection film and its transparent When an adhesive layer or the like provided between the face material does not transmit ultraviolet rays, light is irradiated from the support face material side.

(Process (e))
By peeling the supporting face material from the protective film, an adhesive layer having sufficient adhesive strength was previously formed on the transparent face material, and the generation of voids at the interface between the transparent face material and the adhesive layer was sufficiently suppressed. A transparent surface material with an adhesive layer is obtained.

〔Concrete example〕
Hereinafter, the manufacturing method of the transparent surface material 1 with the adhesion layer of FIG. 1 is demonstrated concretely using drawing.

(Process (a))
As shown in FIG. 5 and FIG. 6, a weir-like portion-forming photocurable resin composition is applied by a dispenser (not shown) or the like along the light-shielding printing portion 12 at the peripheral portion of the protective plate 10 (transparent surface material). Thus, an uncured weir 22 is formed.

(Process (b))
Next, as shown in FIG. 7 and FIG. 8, a layered portion-forming photocurable resin composition 26 is supplied to a rectangular region 24 surrounded by the uncured weir-shaped portion 22 of the protective plate 10. The supply amount of the photocurable resin composition for forming a layered portion 26 is such that the space sealed by the uncured weir-like portion 22, the protective plate 10 and the protective film 16 (see FIG. 9) is photocurable for forming the layered portion. The amount is set in advance so as to be filled with the resin composition 26.

As shown in FIGS. 7 and 8, the layered portion forming photocurable resin composition 26 is supplied by placing the protective plate 10 flat on the lower surface plate 28 and using a dispenser 30 that moves in the horizontal direction. It is carried out by supplying the curable resin composition 26 in the form of a line, a band or a dot.
The dispenser 30 is horizontally movable in the entire range of the region 24 by a known horizontal movement mechanism including a pair of feed screws 32 and a feed screw 34 orthogonal to the feed screw 32. Instead of the dispenser 30, a die coater may be used.

(Process (c))
Next, as shown in FIG. 9, the protective plate 10 and the protective film 16 are attached so that the lower surface 16 a faces the surface to which the layered portion forming photocurable resin composition 26 is supplied. The face material 36 is carried into the decompression device 38. An upper surface plate 42 having a plurality of suction pads 40 is disposed in the upper portion of the decompression device 38, and a lower surface plate 44 is disposed in the lower portion. The upper surface plate 42 can be moved in the vertical direction by an air cylinder 46.
The support surface material 36 is attached to the suction pad 40 with the surface to which the protective film 16 is attached facing down. The protective plate 10 is fixed on the lower surface plate 44 with the surface to which the layered portion forming photocurable resin composition 26 is supplied facing up.

  Next, the air in the decompression device 38 is sucked by the vacuum pump 48. After the atmospheric pressure in the decompression device 38 reaches a decompressed atmosphere of, for example, 15 to 100 Pa, the protection plate 10 waiting underneath while the support surface material 36 is attracted and held by the suction pad 40 of the upper surface plate 42. Then, the air cylinder 46 is moved downward. And the protection board 10 and the support surface material 36 with which the protective film 16 was stuck are piled up through the uncured weir-like part 22. FIG. In this way, a laminate in which the uncured layered portion made of the layer-shaped portion-forming photocurable resin composition 26 is sealed with the protective plate 10, the protective film 16, and the uncured weir-shaped portion 22 is formed, and the reduced pressure atmosphere The laminate is held for a predetermined time under.

(Process (d))
Next, after the inside of the decompression device 38 is, for example, an atmospheric pressure atmosphere, the stacked body is taken out from the decompression device 38. When the laminate is placed in an atmospheric pressure atmosphere, the surface of the laminate on the side of the protective plate 10 and the surface on the side of the support surface 36 are pressed by the atmospheric pressure, and the uncured layered portion in the sealed space becomes the protective plate 10. Pressurized with the support surface material 36. By this pressure, the uncured layered portion in the sealed space flows, and the entire sealed space is uniformly filled with the uncured layered portion.

  Next, light (ultraviolet light or visible light having a short wavelength) is irradiated from the support surface material 36 side to the weir-like portion 22 and the uncured layered portion, the uncured layered portion inside the laminate is cured, and the layered portion and An adhesive layer having a weir-like portion is formed.

(Process (e))
Subsequently, the transparent surface material 1 with the adhesion layer is obtained by peeling the support surface material 36 from the protective film 16.

[Display device]
FIG. 10 is a cross-sectional view showing an example of a display device obtained by the transparent surface material with an adhesive layer of the present embodiment.
The display device 2 includes the display panel 50 and the transparent surface material 1 with the adhesive layer bonded to the display panel 50 so that the adhesive layer 14 is in contact with the display panel 50.
The display device 2 is connected to the protection plate 10, the display panel 50, the layered portion 18 sandwiched between the protection plate 10 and the display panel 50, the weir-like portion 20 surrounding the layered portion 18, and the display panel 50. And a flexible printed wiring board 60 (FPC) on which a driving IC for operating the display panel 50 is mounted.

(Display panel)
As shown in FIG. 10, in the display panel 50 of this embodiment, a transparent substrate 52 provided with a color filter and a transparent substrate 54 provided with a TFT are bonded with a liquid crystal layer 56 interposed therebetween, and this is a pair of polarizing plates 58. 2 is an example of a liquid crystal panel having a configuration sandwiched between two. However, the display panel is not limited to the liquid crystal panel shown in FIG.

  The display panel 50 changes its optical characteristics by an external electric signal between a pair of electrodes, at least one of which is a transparent electrode, or between a substrate having a plurality of electrode pairs formed in the same plane and a transparent substrate. Display material to be sandwiched. There are liquid crystal panels, EL panels, plasma panels, electronic ink panels, and the like depending on the type of display material. Further, the display panel 50 has a structure in which a pair of face materials, at least one of which is a transparent substrate, is bonded, and is arranged so that the transparent substrate side is in contact with the layered portion. At this time, in some display panels, an optical film such as a polarizing plate or a retardation plate may be provided on the outermost layer side of the transparent substrate on the side in contact with the layered portion 18. In this case, the layered portion 18 is in a state of joining the optical film on the display panel and the protective plate.

A surface treatment may be performed on the bonding surface of the display panel 50 with the layered portion 18 in order to improve the interfacial adhesive force with the weir-shaped portion 20. The surface treatment may be performed only on the peripheral edge or on the entire surface of the face material. Examples of the surface treatment method include a treatment method using an adhesion primer or the like which can be processed at a low temperature.
The thickness of the display panel 50 is about 0.4 to 4 mm in the case of a liquid crystal panel operated by a TFT, and is often about 0.2 to 3 mm in the case of an EL panel.

(shape)
The shape of the display panel 50 is a rectangle. The dimensions of the protection plate 10 and the display panel 50 may be substantially equal, or the protection plate 10 may be made slightly larger than the display panel 50 in view of the relationship with other housings that house the display device. Conversely, the protective plate 10 may be made slightly smaller than the display panel 50 depending on the structure of another casing.

[Manufacturing method of display device]
In order to manufacture the display device, after peeling the protective film (protective material) from the transparent surface material with the adhesive layer of this embodiment, the adhesive layer is in contact with the display panel and the transparent surface material with the adhesive layer. Laminate and paste.
The manufacturing method of the display device may be a method including steps S1 and S2 described below.

(Step S1: Protective film peeling step)
In this step, the protective film is peeled from the transparent surface material with the adhesive layer, which is covered with the protective film. Hereinafter, the transparent surface material with the pressure-sensitive adhesive layer from which the protective film has been peeled is referred to as the transparent surface material with the peeled pressure-sensitive adhesive layer. The protective film may be peeled in the air or in a reduced pressure atmosphere. After peeling the protective film, until the transparent surface material with the peeled adhesive layer is transferred to the inside of the vacuum container used in Step S2, the peeled adhesive layer with the adhesive layer is not exposed to the atmosphere in a reduced pressure atmosphere. If it can be stored, it is preferable to carry out peeling of the protective film under a reduced pressure atmosphere. However, it is often difficult to actually remove the protective film in a reduced pressure atmosphere due to production facilities and the like. In that case, there is no particular problem even if the protective film is peeled off in the air. It is preferable to carry out the peeling of the protective film in the air in that it is not necessary to prepare a vacuum container for the protective film peeling step. It is preferable to perform step S2 promptly after the protective film is peeled off.

(Process S2: Pasting process)
In this step, in the bonding apparatus, the display panel and the peeled adhesive layer-attached transparent surface material are bonded together so that the adhesive layer is in contact with the display panel. At this time, in the decompression container of the pasting apparatus, it is preferable to paste the display panel and the peeled transparent surface material with the adhesive layer in a reduced pressure atmosphere. By pasting in a reduced pressure atmosphere, voids are less likely to occur at the interface between the display panel and the adhesive layer. Inside the decompression vessel, after maintaining the decompressed atmosphere for a predetermined time, the decompressed atmosphere is released to normal pressure. The reduced pressure atmosphere at the time of pasting is 1 kPa or less. Furthermore, the reduced pressure atmosphere is preferably 10 to 500 Pa, and more preferably 15 to 200 Pa.

  The time from when the display panel and the peeled adhesive layer-attached transparent surface material are overlapped to the release of the reduced-pressure atmosphere is preferably a short time from the viewpoint of production efficiency. For example, it is preferably within 1 minute, and more preferably within 10 seconds. After the display panel and the peeled adhesive layer-attached transparent face material are bonded, the adhesive layer that is not fully cured is irradiated with light again or heated to accelerate the curing of the adhesive layer. The cured state may be stabilized.

  When the peeled adhesive layer with a peeled adhesive layer is flexible, the peeled adhesive layer with the peeled adhesive layer is curved so that the side of the peeled adhesive layer with the peeled adhesive layer is convex. The transparent surface material with a peeled adhesive layer may be bonded to the display panel gradually from one end side to the other end side. According to this method, since the gas existing in the space between the peeled adhesive layer-attached transparent surface material and the display panel is pushed out from one end side to the other end side, the display panel, the adhesive layer, It becomes difficult to generate voids at the interface.

As shown in FIG. 11, immediately after bonding the peeled adhesive layer-attached transparent surface material 1 and the display panel 50, a gap M <b> 1 that is a sealed space at the interface between the display panel 50 and the adhesive layer 14, Although M2 may occur, most of the voids M1 and M2 generated immediately after bonding disappear after a predetermined time.
The present inventors inferred the mechanism of disappearance of voids generated immediately after bonding as follows.
Three processes of P1, P2, and P3 can be considered as the process of decreasing the volume of the void.

(Process P1: Volume reduction by bonding differential pressure)
In the process P1, after the display panel and the peeled adhesive layer-attached transparent surface material are bonded in a reduced pressure atmosphere, when the pressure is returned to the normal pressure atmosphere, the pressure in the void in the reduced pressure state and the adhesive layer are externally applied. This is a process in which a differential pressure with respect to the pressure (atmospheric pressure) applied is generated, and the volume of the void is reduced by this differential pressure. The period of the process P1 is, for example, about several seconds. That is, the void volume rapidly decreases after a few seconds from when the pressure is returned to the atmospheric pressure.

(Process P2: Volume reduction by absorption of gas in voids into adhesive layer)
Process P2 is a process in which the volume confined in the void is reduced by the gas confined in the void being absorbed and dissolved in the adhesive layer in contact with the void. The period of the process P2 is, for example, about several minutes to several tens of minutes. The rate of void volume reduction in process P2 is slower than the rate of void volume reduction in process P1.

(Process P3: Volume reduction due to gas diffusion in the adhesive layer)
In the process P3, as the gas dissolved in the adhesive layer in the process P2 diffuses from the periphery of the void to the outside thereof, the gas in the void is reabsorbed and re-dissolved in the adhesive layer in contact with the void. This is a process of decreasing the volume of the. That is, the gas concentration remaining in the voids through the process P2 and the gas concentration dissolved in the adhesive layer around the voids are almost in equilibrium. However, this time, the gas concentration dissolved in the adhesive layer around the void and the gas concentration in the adhesive layer at a position away from the void are in a non-equilibrium state. It spreads outside. Through this process, the gas in the gap is reabsorbed and re-dissolved in the adhesive layer in contact with the gap. The period of the process P3 is, for example, several hours or more. The rate of void volume reduction in the process P3 depends on the diffusion rate of the gas in the adhesive layer, and is therefore slower than the rate of void volume reduction in the process P2. The void disappears almost completely through the process P3.

As described above, immediately after the peeled adhesive layer-attached transparent surface material 1 and the display panel 50 are bonded, voids (M1 and M2 in FIG. 11) are generated at the interface between the display panel 50 and the adhesive layer 14.
As a result of the study by the present inventors, it has been found that the conventional transparent surface material with an adhesive layer tends to require a long time for void disappearance when stored for a long time after production. In the transparent face material 1 with a layer, even when it is used for pasting with a to-be-bonded body after a long period of time has elapsed since manufacture, the gap disappears in a short time.

The reason why the void disappears in a short time when the transparent surface material 1 with an adhesive layer of the present embodiment is used can be inferred as follows.
As described above, since the protective film 16 having a low oxygen permeability is used for the transparent surface material 1 with the adhesive layer (see FIG. 1), the transparent surface material 1 with the adhesive layer is under reduced pressure (step (c) )), And can prevent outside air (oxygen, nitrogen, etc.) from passing through the protective film 16 and being mixed into the adhesive layer 14 before being used for bonding with the object to be bonded. .
For this reason, even when the transparent surface material 1 with the adhesive layer is stored for a long time under normal pressure, a state in which the gas (oxygen, nitrogen, water vapor, etc.) derived from the outside air is hardly contained in the adhesive layer 14 is maintained.
Since the gas contained in the adhesive layer 14 is small and the adhesive layer 14 has a large allowable amount capable of dissolving the gas, the gas in the gap is quickly absorbed and dissolved in the adhesive layer 14 in the processes P2 and P3. Is done.
Therefore, when manufacturing the display device, when the peeled adhesive layer-attached transparent surface material 1 is bonded to an object to be bonded (display panel or the like), the gap at the interface between the object to be bonded and the adhesive layer is shortened in a short time. Can be eliminated.
In addition, in order to reduce the gas content dissolved in the adhesive layer 14, it is not necessary to take measures such as deaeration drying prior to the step S2, so that the manufacturing process of the display device can be simplified.

  As described above, the transparent surface material 1 with an adhesive layer (see FIG. 1) is manufactured by bonding the protective film 16 having a rough surface structure on the lower surface 16a to the adhesive layer. At the time of bonding, if the lower surface 16a is not a rough surface structure and has high smoothness, the portion that has been in contact with the lower surface 16a and the adhesive layer 14 may surround a wide area. . In this case, there is no escape space for the gas (oxygen, nitrogen, etc.) in the surrounded region, and there is a possibility that the gas remains as a void in a compressed state.

On the other hand, when the lower surface 16a has a rough surface structure at the time of bonding, a large number of convex portions come into contact with each other at the stage where the lower surface 16a and the adhesive layer 14 have started to come in contact with each other. It is thought that it does not surround the area. In that case, the gas remaining at the stage where contact has begun is exhausted to the outside through the gaps between the many protrusions that have previously contacted. And at the stage where the space | gap of the transparent surface material 1 with the adhesion layer lose | disappeared, it is thought that only a small amount of gas left in the last stage of contact will be absorbed and melt | dissolved in the adhesion layer 14. FIG.
That is, in the transparent surface material 1 with the adhesive layer of the present invention in which the lower surface 16 of the protective film 16 has a rough surface structure, since the gas contained in the adhesive layer 14 is particularly small, the adhesive layer 14 dissolves the gas. Since there is much tolerable amount, the gas in the space | gap produced when bonding with a to-be-bonded body (display panel 50 grade | etc.,) Will be absorbed and melt | dissolved in the adhesion layer 14 rapidly in process P2 and P3. .

When the protective film 16 having the lower surface 16a having a rough surface structure is used, the rough surface structure is transferred to the adhesive layer 14, and the upper surface 14a on the protective film 16 side of the adhesive layer 14 also follows the lower surface 16a. A rough surface structure or a similar rough surface structure is considered. As a result, when the upper surface 14a and the object to be bonded are in contact with each other when the object to be bonded (the display panel 50 or the like) is bonded, a large number of the convex portions are in contact with each other. Does not encircle. In this case, the gas remaining at the stage where contact has begun is exhausted to the outside through the gaps between the many protrusions that have previously contacted. Therefore, in order to eliminate the voids, the adhesive layer 14 only needs to absorb a small amount of gas left in the final stage of contact.
Furthermore, the gas left in the final stage of contact exists in a dispersed state as extremely small voids, and large voids are unlikely to remain. Therefore, each space | gap is absorbed simultaneously by the adhesive layer surrounding the circumference | surroundings.
That is, when the transparent surface material 1 with the adhesive layer of the present invention in which the lower surface 16 of the protective film 16 has a rough surface structure, the gas to be absorbed by the adhesive layer 14 is small, and each gas is dispersed. Since it exists, it is thought that the gas in the space | gap produced when bonding with a to-be-bonded body (display panel 50 grade | etc.,) Is rapidly absorbed and melt | dissolved in the adhesion layer 14 in process P2, P3.

The technical scope of the present invention is not limited to the embodiment described above, and various modifications can be made without departing from the spirit of the present invention.
In this invention, the peripheral part of the protective film of the transparent surface material with an adhesion layer can also be airtightly joined to a protective plate (transparent surface material) over the perimeter under pressure reduction conditions. For example, the peripheral edge portion of the protective film 16 of the transparent face material 1 with the adhesive layer shown in FIG. 1 is hermetically bonded to any position (side surface, lower surface, upper surface, etc.) of the protective plate 10 under the reduced pressure condition. can do.
As a result, the adhesive layer 14 is hermetically wrapped in the protective film 16, so it is possible to reliably prevent outside air from being mixed into the adhesive layer 14.
Moreover, it is possible to prevent the outside air from being mixed into the adhesive layer by encapsulating the transparent surface material with the adhesive layer in an enclosure made of a film having a gas barrier property under reduced pressure conditions.

In the said embodiment, although the transparent surface material with an adhesion layer was bonded to the display panel and the method of manufacturing a display apparatus (laminated body) was demonstrated, the transparent surface material with an adhesion layer is used for coordinate input devices, such as a touch panel, for example. You may paste and use.
Further, the transparent surface material may be a transparent surface material with a transparent electrode that constitutes a touch panel portion in a display device with a touch panel. An adhesive layer can also be formed on both surfaces of the transparent surface material on which the touch panel is formed, and the protective plate and the display panel can be bonded via a touch panel substrate on which the adhesive layer is formed on both surfaces.
In the above production method, the gas content of the adhesive layer is reduced by placing the adhesive layer under reduced pressure conditions in the production process of the transparent surface material with the adhesive layer, but the gas content of the adhesive layer is reduced under reduced pressure. As long as it is before the process of bonding a transparent surface material with an adhesion layer to a thing to be pasted, any process may be sufficient as the process which decreases.

  The inventor has demonstrated through experiments the effect of void disappearance in the method of manufacturing the display device of the present embodiment. The experimental results will be described in the following [Example] section.

Below, the example implemented in order to confirm the effectiveness of this invention is shown.
[Example 1]
(Transparent surface material)
Black pigment on the outer periphery of the translucent part so that the translucent part has a length of 70 mm and a width of 70 mm in the center of the glass plate on one surface of soda lime glass having a length of 100 mm, a width of 100 mm and a thickness of 1.3 mm A light-shielding print portion was formed by printing and baking an organic ink containing sinter so that the thickness after firing was about 10 μm, and a transparent surface material A (protective plate A) was obtained.

(Protective film)
The protective film 16 (16B) shown in FIG. 3 was used.
A self-adhesive layer is formed on the surface 3a of the first support material 3 (polypropylene film), and a roughened back layer is formed on the surface 3b (back surface) by a co-extrusion method and biaxially stretched (manufactured by Phutamura Chemical) FSA-300M, thickness 30 μm) and a barrier film (IB-PET-, manufactured by Dai Nippon Printing Co., Ltd.) formed by an PVD method on one side of the second support material 5 (PET film) as a gas barrier layer 4 PXB, thickness 12 μm).
A barrier film is bonded to the surface 3a of the first support material 3 from the gas barrier layer 4 side, and a slightly adhesive layer 8 (acrylic adhesive, thickness 3 μm) is formed on the surface 5a of the second support material 5. Thus, protective film 16 (16B) was obtained.
The oxygen permeability of the protective film 16 was 8 cc / m ² · day · atm, and the nitrogen permeability was ² cc / m ² · day · atm.

(Support surface material)
Soda lime glass having a length of 100 mm, a width of 100 mm, and a thickness of 1.1 mm was used as the support surface material B.

(Laminated objects such as display panels)
Adhering a polarizing plate with an adhesive layer (Polatechno Co., Ltd., KN-18240T) on one surface of soda lime glass with a length of 90 mm, a width of 90 mm, and a thickness of 1.7 mm to be used instead of a liquid crystal display panel Interfacial material C was designated.

(Photo-curable resin composition for weir-like portion formation)
Bifunctional polypropylene glycol whose molecular terminal is modified with ethylene oxide (number average molecular weight calculated from hydroxyl value: 4,000) and hexamethylene diisocyanate are mixed in a molar ratio of 6 to 7, and then isobornyl acrylate is mixed. After diluting with IBXA (manufactured by Osaka Organic Chemical Industry Co., Ltd.), to the prepolymer obtained by reacting at 70 ° C. in the presence of a tin compound catalyst, 2-hydroxyethyl acrylate in a molar ratio of approximately 1: 2. In addition, by reacting at 70 ° C., a urethane acrylate oligomer (hereinafter referred to as UC-1) solution diluted with 30% by mass of isobornyl acrylate was obtained. The number of curable groups of UC-1 was 2, and the number average molecular weight was about 55,000. The viscosity of the UC-1 solution at 60 ° C. was about 580 Pa · s.

90 parts by mass of the UC-1 solution and 10 parts by mass of 2-hydroxybutyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light ester HOB) were uniformly mixed to obtain a mixture. 100 parts by weight of the mixture, 0.9 part by weight of 1-hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, manufactured by Ciba Specialty Chemicals, IRGACURE 184), bis (2,4,6-trimethylbenzoyl) ) -Phenylphosphine oxide (photopolymerization initiator, Ciba Specialty Chemicals, IRGACURE 819) 0.1 parts by mass, 2,5-di-t-butylhydroquinone (polymerization inhibitor, manufactured by Tokyo Chemical Industry Co., Ltd.) Was uniformly mixed to obtain a photocurable resin composition D for weir-like portion formation.
Defoaming treatment is performed by placing the photocurable resin composition D for forming the weir-like portion in the container in an open state in a decompression device, reducing the pressure in the decompression device to about 20 Pa, and holding for 10 minutes. It was. It was about 1470 Pa.s when the viscosity at 25 degrees C of the photocurable resin composition D for weir-like part formation was measured.

(Photocurable resin composition for layered portion formation)
A bifunctional polypropylene glycol whose molecular terminal is modified with ethylene oxide (number average molecular weight calculated from hydroxyl value: 4,000) and isophorone diisocyanate are mixed at a molar ratio of 4 to 5 in the presence of a tin compound catalyst. The urethane acrylate oligomer (hereinafter referred to as UA-1) is obtained by adding 2-hydroxyethyl acrylate at a molar ratio of about 1: 2 to the prepolymer obtained by reacting at 70 ° C. and reacting at 70 ° C. .) The number of curable groups of UA-1 was 2, the number average molecular weight was about 24,000, and the viscosity at 25 ° C. was about 830 Pa · s.
40 parts by mass of UA-1, 30 parts by mass of 2-hydroxybutyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light ester HOB) and 30 parts by mass of n-dodecyl methacrylate were uniformly mixed, and 100 parts by mass of the mixture 0.3 part by mass of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (photopolymerization initiator, manufactured by Ciba Specialty Chemicals, IRGACURE 819), 2,5-di-t-butylhydroquinone 0.04 parts by mass (polymerization inhibitor, manufactured by Tokyo Chemical Industry Co., Ltd.), 0.3 parts by mass of UV absorber (manufactured by Ciba Specialty Chemicals, TINUVIN 109), and n-dodecyl mercaptan (chain transfer agent, Kao) 0.3 parts by mass of Thiocalcol 20) manufactured by the company was uniformly dissolved to obtain a composition PD.
Next, 70 parts by mass of the composition PD and the same bifunctional polypropylene glycol having molecular ends modified with ethylene oxide (number average molecular weight calculated from the hydroxyl value: 4,000), the same as those used in the synthesis of UA-1. And 30 parts by mass of 1) were uniformly dissolved to obtain a photocurable resin composition E for forming a layered part.

(Attaching the protective film to the support surface material)
A protective film was attached to one side of the supporting surface material using a rubber roll so that the slightly adhesive surface of the protective film was in contact with the supporting surface material, to prepare a supporting surface material B on which the protective film was adhered.

(Transparent surface with adhesive layer)
A transparent surface material with an adhesive layer was prepared by the following steps (a) to (e).
(Process (a))
Dispensing the photocurable resin composition D for forming the weir-like portion so as to have a width of about 1 mm and a coating thickness of about 0.6 mm over the entire circumference at a position of about 2 mm from the end of one surface of the transparent surface material A Was applied to form an uncured weir.
(Process (b))
In a region inside the uncured weir-like portion applied to the transparent face material A, the layered portion-forming photocurable resin composition E is placed at a plurality of locations using a dispenser so that the total mass becomes 3.5 g. Supplied.
While the photocurable resin composition E for forming a layered portion was supplied, there was no breakage such as breakage, and the shape of the uncured weir-shaped portion was maintained.

(Process (c))
The transparent surface material A was placed flat on a lower surface plate in a decompression device in which a pair of surface plate raising and lowering devices are installed so that the surface of the layered portion forming photocurable resin composition E is on top. . Using the electrostatic chuck on the lower surface of the upper surface plate of the lifting device in the decompression device, the support surface material B with the protective film adhered is vertically spaced from the support surface material B with the protective film adhered. It was hold | maintained so that it might be set to 30 mm.

The decompression device was sealed and evacuated until the pressure in the decompression device reached about 10 Pa. The upper and lower surface plates are brought close to each other by an elevating device in the decompression device, and the transparent surface material A and the support surface material B to which the protective film is attached are passed through the photocurable resin composition E for layered portion formation. The pressure was applied at a pressure of 2 kPa and held for 1 minute. Static electricity is removed from the electrostatic chuck, the supporting surface material is separated from the upper surface plate, and the pressure reducing device is returned to the atmospheric pressure atmosphere in about 15 seconds. A layered portion is formed by the transparent surface material A, the protective film, and the uncured weir-shaped portion. The laminated body F with which the uncured layered part which consists of the photocurable resin composition E for use was sealed was obtained.
In the laminated body F, the shape of the uncured weir-like portion was maintained in an almost initial state.

(Process (d))
The uncured weir-like portion and the uncured layer-like portion of the laminate F are uniformly irradiated with ultraviolet rays from a chemical lamp and visible light of 450 nm or less from the support surface material B side, An adhesive layer was formed by curing the uncured layered portion. In spite of the fact that the step of removing voids required during the production by the conventional injection method is unnecessary, defects such as voids remaining in the adhesive layer were not confirmed. Moreover, defects such as leakage of the photocurable resin composition for forming a layered portion from the weir-shaped portion were not confirmed. Further, the thickness of the adhesive layer was a target thickness (about 0.4 mm).

(Process (e))
By peeling off the supporting surface material B from the protective film, a transparent surface material G1 with an adhesive layer to which the protective film was attached was obtained.

(Manufacture of display devices (laminates))
The produced transparent surface material with adhesive layer G1 was stored in a thermostatic chamber for 120 hours under the condition of 100 ° C. After removing from the thermostatic chamber, the transparent surface material G2 with the adhesive layer from which the protective film was peeled off in the air (hereinafter referred to as the transparent surface material G2 with the peeled adhesive layer) was moved up and down within a minute. An adhesive pad and an electrostatic chuck were used to hold the upper surface plate in the decompression device in which the device was installed so that the surface of the adhesive layer faced downward.
The bonded surface material C is placed on the upper surface of the lower surface plate of the lifting device in the decompression device so that the polarizing plate bonded to the bonded surface material C faces the pressure-sensitive adhesive layer of the peeled-off transparent surface material with adhesive layer G2. It was arrange | positioned and it was made to hold | maintain so that the distance with the transparent surface material G1 with an adhesion layer might be set to 30 mm.

The decompression device was sealed and evacuated until the pressure in the decompression device reached about 10 Pa. The time until the pressure in the decompression device decreased to 10 Pa was 31 seconds. This reduced pressure state (10 Pa) was maintained for 2 minutes.
After adjusting the arrangement so that the center surface of the peeled adhesive layer with adhesive layer G2 and the surface material C to be bonded coincide with each other, the upper and lower surface plates are brought close to each other by the lifting device in the decompression device. The polarizing plate attached to the face material C and the peeled adhesive layer-attached transparent face material G2 were pressure-bonded with a pressure of 2 kPa through the adhesive layer of the peeled adhesive layer-attached transparent face material G2, and held for 10 seconds. . Static electricity was removed from the electrostatic chuck, the bonded body was separated from the upper surface plate, and the inside of the decompression device was returned to atmospheric pressure in about 20 seconds to obtain a laminate H.

  When the laminated body H was observed immediately after lamination with the peeled adhesive layer-attached transparent surface material G2, the polarizing plate surface adhered to the bonded face material C and the adhesive layer of the peeled adhesive layer-attached transparent surface material G2 Many fine voids (bubbles) were observed at the interface. The laminate H was allowed to stand, and the time until voids disappeared (void disappearance time) was measured. The results are shown in Table 1. The void disappearance time was the average of the results of three samples.

[Example 2]
The transparent surface material with an adhesive layer produced by the same production method as in [Example 1] is stored for 240 hours in a thermostatic chamber at 40 ° C., and the same as the bonding method described in [Example 1]. A laminate was obtained under the following conditions.

Example 3
The adhesive layer-attached transparent surface material produced by the same production method as in [Example 1] is stored in a constant temperature bath for 300 hours in the atmosphere at 25 ° C., and the bonding method described in [Example 1] A laminate was obtained under the same conditions.

[Comparative Example 1]
As a protective film, a self-adhesive layer is formed on one surface of a polypropylene film, and a roughened back layer is formed on the other surface by a coextrusion method, and a biaxially stretched film (FSA-010M, manufactured by Futamura Chemical Co., Ltd., thickness) 46 μm) was used.
The oxygen permeability of this protective film was 1,980 cc / m ² · day · atm, and the nitrogen permeability was 450 cc / m ² · day · atm.
The transparent surface material with an adhesive layer produced by the same production method as in [Example 1] is stored in a thermostatic bath at 100 ° C. for 120 hours, and similar to the bonding method described in [Example 1]. A laminate was obtained under the following conditions. When observed immediately after lamination, a large number of fine voids (bubbles) were observed at the interface between the bonding surface material C and the adhesive layer of the transparent surface material with adhesive layer G1, and even after 24 hours storage at room temperature, the fine voids were observed. It remained.

[Comparative Example 2]
The transparent surface material with an adhesive layer produced by the same production method as in [Comparative Example 1] is stored for 240 hours in a thermostatic chamber under the condition of 40 ° C., and is the same as the bonding method described in [Comparative Example 1]. A laminate was obtained under the following conditions.

[Comparative Example 3]
The adhesive layer-attached transparent face material produced by the same production method as in [Example 1] is stored in the thermostatic chamber for 300 hours in the atmosphere at 25 ° C., and the bonding method described in [Comparative Example 1] A laminate was obtained under the same conditions.

[Achievement of reduced pressure during the production of the laminate and the time of disappearance of bubbles after bonding]
The storage conditions of the transparent surface material G1 with the adhesive layer used to manufacture the laminate H, the time required to reduce the pressure in the decompression device in the manufacturing process of the display device to 10 Pa, and the same as in Example 1 After the laminated body was prepared under the conditions, the time until the gap at the interface between the polarizing plate surface adhered to the bonding surface material C and the adhesive layer of the transparent surface material G2 with peeled adhesive layer disappeared (void) (Disappearance time) was measured. The reduced pressure holding time before the lamination of the peeled adhesive layer with a transparent layer G2 was 2 minutes. The results are shown in Table 1.

As shown in Table 1, it was confirmed that in the examples using the protective film having a low oxygen permeability, the gap disappearance time was shortened as compared with the comparative example. In particular, it is considered that it corresponds to the case where the transparent surface material with the adhesive layer is stored in the atmosphere for a long time until the production of the laminate. The gap disappearance time after lamination with the face material C can be remarkably shortened.
Further, the longer the time until the pressure in the decompression device is reduced to 10 Pa, the longer the void disappearance time tends to be.

The present invention can be used for a display device including various display panels, a coordinate input device, and the like.
The specification, claims, and drawings of Japanese Patent Application No. 2012-222051 filed in Japan on October 4, 2012 and Japanese Patent Application No. 2012-227975 filed in Japan on October 15, 2012 And the entire contents of the abstract are hereby incorporated by reference into the present disclosure.

1: transparent surface material with adhesive layer, 2: display device, 10: transparent surface material (protective plate), 3: first support material, 4: gas barrier layer (barrier layer), 14: adhesive layer,
16: protective film, 50: display panel.

Claims (8)

Transparent face material,
An adhesive layer formed on at least one surface of the transparent face material;
A peelable protective film that covers the surface of the adhesive layer opposite to the transparent face material side,
The protective film has a pressure-sensitive adhesive layer-containing transparent surface material having an oxygen permeability of 100 cc / m ² · day · atm or less.   The said protective film is a transparent surface material with the adhesion layer of Claim 1 which has a gas barrier layer formed from the layer containing an inorganic compound.   The said protective film is a transparent surface material with the adhesion layer of Claim 1 or 2 whose ten-point average roughness Rz of the surface at the side of the said adhesion layer is 2.0-20 micrometers.   The transparent surface material with the adhesion layer as described in any one of Claims 1-3 whose said transparent surface material is a protection board of a display apparatus. With an adhesive layer comprising a transparent surface material, an adhesive layer formed on at least one surface of the transparent surface material, and a peelable protective film that covers the surface of the adhesive layer opposite to the transparent surface material side A method for producing a transparent face material,
As the protective film, a film having an oxygen permeability of 100 cc / m ² · day · atm or less is used.
After supplying the photocurable resin composition or the thermosetting resin composition on the transparent face material, the protective film is in a reduced pressure atmosphere of 1 kPa or less, and the side of the transparent face material on which the composition is supplied. A laminate is formed by laminating on the transparent surface material through the composition so as to come into contact, and then placed under a pressure atmosphere of 50 kPa or more to cure the photocurable resin composition or the thermosetting resin composition. The manufacturing method of the transparent surface material with the adhesion layer characterized by the above-mentioned.   The manufacturing method of the transparent surface material with the adhesion layer of Claim 5 using the film whose ten-point average roughness Rz of the surface at the side of the said adhesion layer is 2.0-20 micrometers as said protective film. A display device comprising a display panel and a transparent surface material bonded via a pressure-sensitive adhesive layer on the surface on the viewing side of the display panel,
The said transparent surface material and the said adhesion layer peel | peel the said protective film of the transparent surface material with an adhesion layer as described in any one of Claims 1-4, The display apparatus characterized by the above-mentioned. A manufacturing method of a display device having a display panel and a transparent surface material to be bonded via an adhesive layer on a surface on the viewing side of the display panel,
After peeling off the protective film of the transparent surface material with the adhesive layer obtained by the production method according to claim 5, the display panel is bonded to the transparent surface material with the adhesive layer from which the protective film is peeled off. A manufacturing method of a display device characterized by the above.

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