JP3707263B2 - Front plate for display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display front plate.
[0002]
[Prior art]
The display front plate is a front plate used by being disposed on the front surface of the display device. Among display devices, flop plasma display device is useful as a large display device.
[0003]
The front plate used in such a plasma display serves as a protective plate for protecting the screen of the plasma display device, adjusts the color of the display display, reflects external light, and prevents reflection, plasma display electromagnetic waves generated from the device, even those responsible for various functions such as the ability to shield the infrared certain. These functions are given, for example, by laminating various functional plastic films that give the above functions to one or both sides of a transparent substrate. For laminating a functional plastic film to a transparent substrate, for example, acrylic A pressure sensitive adhesive or the like is used.
[0004]
On the other hand, a plasma display has a larger calorific value than a conventional cathode ray tube (CRT) having a relatively large calorific value. Therefore, a front plate used for a plasma display is different from a conventional CRT front plate. In comparison, durability at higher temperatures is also required. Furthermore, it is also assumed that the plasma display is used in high temperatures, for example, in open-air under hot weather, saunas, and the like.
[0005]
However, when a transparent resin substrate is used as the transparent substrate, bubbles may easily occur inside the front plate when used under high temperature drying or high temperature and humidity, and therefore, various conditions over a long period of time. In the use of the plasma display apparatus below, there was concern about the generation of bubbles inside the front plate.
[0006]
In order to suppress the generation of such bubbles, a glass substrate may be used as the transparent substrate, but there is a problem that it is relatively weak against impact and tends to be heavy.
Moreover, when using a transparent resin substrate as a transparent substrate, a hard coat layer is provided on the surface of the transparent resin substrate and used as a hard coat transparent resin substrate, and a functional plastic film may be bonded to one or both sides. Although it is conceivable, in addition to requiring an extra step of providing a hard coat layer on the transparent resin substrate, foreign matter may be mixed in the step of providing a hard coat layer, and it could not be said that it was sufficiently satisfactory .
[0007]
[Problems to be solved by the invention]
Internal Accordingly, the present inventors have found that in de Isupurei for front plate obtained by laminating a plastic film through a pressure-sensitive adhesive layer to a transparent resin substrate, high-temperature dryness under even when used for a long period of time under high temperature and high humidity the result of extensive studies to develop the generated difficulty decoction Isupurei front panel for the air bubbles, the plastic film having a specific moisture permeability as a plastic film for imparting functionality to the transparent substrate through an adhesive layer The bonded front plate was found to be less likely to generate air bubbles over a long period of time even under high temperature drying and high temperature and humidity, and reached the present invention.
[0008]
[Means for Solving the Problems]
That is, the present invention is, on at least one surface of the transparent resin substrate, a Lud Isupurei front panel for such a via a pressure-sensitive adhesive layer laminate plastic film is laminated, the moisture permeability of the plastic film there is provided a front plate, characterized in that at 10g / m ^2/24 hours or more.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The transparent resin substrate is applied to a de Isupurei for the front plate of the present invention, for example, acrylic resin plate, a polycarbonate resin plate, polyethylene terephthalate plate, polyethylene, such as polyolefin resin plate made of polypropylene thermoplastic resin plate such as Is mentioned. Although the hard coat layer may be provided on the surface of the transparent resin substrate, the effect of the present invention is remarkable when a transparent resin substrate not provided with the hard coat layer is used. The transparent substrate may have an infrared shielding function for shielding infrared rays, for example. The infrared shielding function can be imparted, for example, by containing a compound that absorbs infrared rays. The thickness of the transparent resin substrate is not particularly limited, but is usually about 0.1 to 20 mm.
[0010]
De Isupurei for the front plate of the present invention, on one or both sides of such a transparent resin substrate, a pressure sensitive although plastic films via an adhesive layer is laminated, the plastic film is its moisture permeability 10 g / m ² / It must be 24 hours or longer. Here, the moisture permeability is measured according to JIS Z 0208.
[0011]
Moisture permeability tends bubbles are generated in the high temperature drying under is less than 10g / m ^2/24 hours, preferably 20g / m ^2/24 hours or more. Incidentally, such a moisture permeability is usually at most 1500g / m ^2/24 hours.
[0012]
Such plastic film has a color adjustment function of display display color, an anti-reflection function of external light, an anti-reflection function, an anti-contamination layer for preventing contamination, an electromagnetic wave shielding function for shielding electromagnetic waves generated from a plasma display, Various functions such as an infrared shielding function for shielding infrared rays generated from the plasma display are added.
[0013]
The color tone adjusting function can be imparted, for example, by including a dye, a pigment or the like in the plastic film.
The antireflection function of external light can be imparted, for example, by providing an antireflection film on the outer surface of the plastic film (the surface opposite to the side laminated on the transparent resin substrate). An antireflection film is a layer that can reduce the reflectance of visible light, for example, a thin film in which layers made of a low refractive index substance and layers made of a high refractive index substance are alternately laminated, a low refractive index Examples thereof include a thin film made of a material having a thickness of about 0.05 to 0.3 μm.
The reflection preventing function can be imparted, for example, by providing fine irregularities on the outer surface of the plastic film.
The antifouling layer may be provided, for example, by applying a substance capable of preventing the adhering of fouling to the outer surface of the plastic film, for example, by applying a coupling agent such as a fluorine coupling agent or a silane coupling agent and then drying. The coupling agent is usually applied diluted in a solvent.
[0014]
The electromagnetic wave shielding layer can be applied by, for example, a method of providing a transparent conductive layer over the entire surface or a method of providing a lattice-shaped conductive layer on one surface or both surfaces of a plastic film. Examples of the transparent conductive layer include a layer made of indium-tin composite oxide (ITO), and a thin film in which conductive metal layers and transparent high refractive index layers are alternately stacked. Examples of the conductive metal layer include silver and a layer containing silver as a main component. Examples of the lattice-shaped conductive layer include a conductive thin film provided in a lattice shape, a conductive mesh in which conductive fibers are woven in a lattice shape, and the like.
Examples of the infrared shielding function include a method in which a compound capable of absorbing infrared rays is contained in a plastic film, and a method in which a layer that reflects infrared rays is provided on one side or both sides of a plastic film. Examples of the layer that reflects infrared rays include a layer made of silver.
[0015]
One of these functions may be given to one plastic film, and two or more functions may be given. For example, when an electromagnetic wave shielding layer is a thin film in which silver or a conductive metal layer mainly composed of silver and a dielectric layer are alternately laminated, the conductive metal layer reflects infrared rays. A shielding function can also be provided.
[0016]
The material of the plastic film is not particularly limited as long as it satisfies the above moisture permeability and can be laminated on a transparent resin plate with a pressure-sensitive adhesive. For example, a cellulose resin such as triacetyl cellulose (TAC) is used. And polyester resins such as polycarbonate resin (PC) and polyethylene terephthalate (PET); acrylic resins such as polymethyl methyl methacrylate (PMMA); and polyolefin resins such as polyethylene and polypropylene.
The thickness of the plastic film is appropriately selected within a range satisfying moisture permeability, and is not particularly limited, but is, for example, about 10 μm to 300 μm.
[0017]
In the display front plate of the present invention, such a plastic film is laminated on a transparent resin substrate via a pressure-sensitive adhesive layer. Examples of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer include an acrylic pressure - sensitive adhesive and a urethane pressure-sensitive adhesive. Although the thickness of a pressure sensitive adhesive layer is not specifically limited, Usually, it is about 10-200 micrometers.
[0018]
Laminates used for the de Isupurei front plate of the present invention, for example, a pressure sensitive adhesive layer provided on one side of a plastic film, which can be produced by bonding a transparent resin substrate. Alternatively, a pressure-sensitive adhesive layer may be applied to the surface of the transparent resin substrate, and a plastic film may be bonded thereon. The bonding method is not particularly limited. For example , a transparent resin substrate having a predetermined size and a plastic film cut into a predetermined size may be overlapped and then pressed, or a predetermined size may be used. The transparent resin substrate and the belt-shaped plastic film may be overlaid and then pressed, and then the belt-shaped plastic film may be cut.
[0019]
The laminated plate thus obtained is used as a front plate mounted on the front surface of a display device, particularly a plasma display device.
[0020]
【The invention's effect】
Since the front plate for display of the present invention is less likely to generate air bubbles over a long period of time even under high temperature drying or high temperature and humidity, compared with the conventional CRT front plate, it is under higher temperature drying and higher temperature and humidity. It can be used for a front panel for a plasma display that requires durability underneath, and is excellent in durability over a long period of time. Also, a display device for use at high temperatures, may be used as a front plate of that.
[0021]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.
[0022]
In addition, evaluation of the laminated board obtained by each Example was performed with the following method.
(1) Durability under high temperature drying The laminate was allowed to stand for 120 hours under drying at 80 ° C., and then both surfaces of the laminate were visually observed and evaluated according to the following criteria.
○: Bubbles are not generated.
(Triangle | delta): Generation | occurrence | production of a bubble is recognized in a part of edge part.
X: Generation | occurrence | production of a bubble is recognized by both an edge part and the center part.
(2) Durability at high temperature and high humidity The laminate was allowed to stand at 60 ° C. and 90% humidity for 120 hours, and then both surfaces of the laminate were visually observed and evaluated according to the following criteria.
○: Bubbles are not generated.
(Triangle | delta): Generation | occurrence | production of a bubble is recognized in a part of edge part.
X: Generation | occurrence | production of a bubble is recognized by both an edge part and the center part.
(3) Moisture permeability of plastic film Measured according to JIS Z 0208.
[0023]
Example 1
TAC film [thickness: 139 μm] on both sides of a transparent resin plate (manufactured by Sumitomo Chemical Co., Ltd., “Sx0000”, acrylic resin plate, thickness 3 mm, size 200 mm × 300 mm, no hard coat layer on the surface) plastic film having an antireflection function pressure sensitive adhesive layer is provided on a surface opposite the antireflection layer is provided on one side [ "ReaLook 2201", manufactured by NOF Corporation, moisture permeability 234g / m ^2/24 Time, size 200 mm × 300 mm] was laminated on the pressure-sensitive adhesive layer side to obtain a laminate. The evaluation results of this laminate are shown in Table 1. Even if this laminated plate is used as a plasma display front plate arranged in front of the plasma display, bubbles are hardly generated inside for a long period of time.
[0024]
Example 2
On one surface of the same transparent resin plate (“Sx0000”, thickness 3 mm, size 200 mm × 300 mm, no hard coat layer on the surface) used in Example 1, an antireflection function plastic film [“Realak 2201 ”200 mm × 300 mm in size” on the pressure-sensitive adhesive layer side and a plastic film having an anti-glare function on the other side [TAC film with fine irregularities on the surface, thickness 84 μm, moisture permeability 227 g / the m ^2/24 hr] was laminated via an acrylic pressure sensitive adhesive, to obtain a laminate. The evaluation results of this laminate are shown in Table 1. Even if this laminated plate is used as a plasma display front plate arranged in front of the plasma display, bubbles are hardly generated inside for a long period of time.
[0025]
Example 3
On one surface of the same transparent resin plate [“Sx0000”, thickness 3 mm, size 200 mm × 300 mm, no hard coat layer on the surface] used in Example 1, PET film [thickness 23 μm, moisture permeability 24 g / m ^2/24 hours, the size of 200 mm × 300 mm], were laminated via an acrylic pressure sensitive adhesive, to obtain a laminate. The evaluation results of this laminate are shown in Table 1. Even if this laminated plate is used as a plasma display front plate arranged in front of the plasma display, bubbles are hardly generated inside for a long period of time.
[0026]
Example 4
Instead of the PET film, acrylic resin film having a hard coat layer on one side [thickness 130 .mu.m, moisture permeability 24g / m ^2/24 hours, 200 mm × 300 mm size] using acrylic and the hard coat layer side to the outside A laminate is obtained in the same manner as in Example 3 except that the laminate is laminated on the transparent resin plate (“Sx0000”) via a pressure-sensitive adhesive. Even if this laminate is left for a long period of time under high temperature drying or high temperature and high humidity, almost no bubbles are generated inside. Further, even if this laminated plate is used as a plasma display front plate disposed on the front surface of the plasma display, bubbles are hardly generated inside for a long period of time.
[0027]
Example 5
Instead of the PET film, polycarbonate resin film having a hard coat layer on one side [thickness 129Myuemu, moisture permeability 29g / m ^2/24 hours, 200 mm × 300 mm size] using acrylic and the hard coat layer side to the outside A laminate is obtained in the same manner as in Example 3 except that the laminate is laminated on the transparent resin plate (“Sx0000”) via a pressure-sensitive adhesive. Even if this laminate is left for a long period of time under high temperature drying or high temperature and high humidity, almost no bubbles are generated inside. Further, even when this laminated plate is used as a front plate for a plasma display by being arranged on the front surface of the plasma display, almost no bubbles are generated inside for a long period of time.
[0028]
Comparative Example 1
On one surface of the same transparent resin plate (“Sx0000”, thickness 3 mm, size 200 mm × 300 mm, no hard coat layer on the surface) used in Example 1, an antireflection function plastic film [“Realak 2201 ”, 200 mm × 300 mm in size” on the pressure-sensitive adhesive layer side, and has a thin film with silver layers and indium oxide layers alternately laminated on one side over the entire surface, PET film having an infrared shielding function [thickness 50 [mu] m, moisture permeability 0g / m ^2/24 hours, 200 mm × 300 mm size] were laminated via an acrylic pressure sensitive adhesive, to obtain a laminate. The evaluation results of this laminate are shown in Table 1. When this laminated plate is disposed on the front surface of the plasma display as a front plate for plasma display and used for a long period of time, there is a possibility that bubbles are generated between the PET film and the transparent resin substrate.
[0029]
Comparative Example 2
On one side of the same transparent resin plate [“Sx0000”, thickness 3 mm, size 200 mm × 300 mm, no hard coat layer on the surface] used in Example 1, PET film [thickness 184 μm, moisture permeability 3 g / m ^2/24 hours, a 200 mm × 300 mm] size are laminated via an acrylic pressure sensitive adhesive, to obtain a laminate. The evaluation results of this laminate are shown in Table 1. When this laminated plate is disposed on the front surface of the plasma display as a front plate for plasma display and used for a long period of time, there is a possibility that bubbles are generated between the PET film and the transparent resin substrate.
[0030]
[Table 1]

Claims (2)

On at least one surface of a transparent resin substrate, a display front plate comprising a laminate of plastic film is laminated via a pressure sensitive adhesive layer, the moisture permeability is ² 0g / m 2/24 hours of the plastic film A display front plate characterized by the above. The display front plate according to claim 1, which is used in a plasma display device.