JP2001215310A - Non-glare layer and optical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a non-glare layer which can prevent deterioration of a display quality level of a clear image by preventing reflection of outside view and suppressing glaring of the image. SOLUTION: An optical member has a non-glare layer, consisting of a transparent resin layer having a fine rugged structure on the surface, the standard deviation of the height H of a projected part 12 making the depth of the deepest bottom 11 in the fine detailed rugged structure of the surface as a reference L1 is 0.3 μm or less, or the standard deviation of the interval S of top and a bottom making the average height of the uneven parts 11 and 12 as a reference L2 is 10 μm or less, a non-glare layer on at least one side of a transparent film base material, a polarizing plate, or an elliptically polarizing plate. Various display devices, such as a liquid crystal display device which enables keeping definition also in the case of an image with high definition by miniaturizing of pixel sizes, or the like, and is excellent in a display quality level, are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-glare layer suitable for preventing reflection of external scenery and glare in various display devices.

[0002]

2. Description of the Related Art Conventionally, in various display devices such as a CRT, a plasma display, and a liquid crystal display device, the display device is provided on a surface of a screen or the like in order to prevent an image from being disturbed due to a scene reflected by external light of a fluorescent lamp. As a non-glare layer to be obtained, a resin layer containing transparent fine particles and having a thickness of about 5 to 10 μm has been known. This has a non-glare effect by irregularly reflecting external light with a fine uneven structure on the surface. However, with the recent improvement in image quality due to miniaturization of pixel size and higher quality due to flat panel technology, the conventional non-glare layer has a problem that the unevenness of the image causes glare in the image and lowers the display quality. .

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to develop a non-glare layer capable of preventing glare of an image while preventing reflection of an outside scene and preventing deterioration in display quality of a clear image.

[0004]

According to the present invention, there is provided a transparent resin layer having a fine uneven structure on the surface, wherein the standard deviation of the height of the convex portion based on the depth of the deepest valley in the fine uneven surface structure is zero. .3 μm or less, or a non-glare layer characterized in that the standard deviation of the peak-to-valley interval based on the average height of the irregularities is 10 μm or less, and the non-glare layer is at least a transparent film substrate, a polarizing plate or an elliptically polarizing plate. An optical member characterized by being provided on one side is provided.

[0005]

According to the present invention, the above-mentioned fine surface unevenness structure in which the unevenness of the height of the convex portions or the interval between the peaks and valleys is suppressed is effectively prevented from reflecting an external scene, and the pixel size is reduced. Thus, even in the case of a high-definition image, it is possible to obtain a variety of display devices, such as a liquid crystal display device, which can suppress the occurrence of glare and maintain the sharpness, and are excellent in display quality such as visibility.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A non-glare layer according to the present invention comprises a transparent resin layer having a fine uneven structure on its surface, and has a standard height of a convex portion based on the depth of the deepest valley in the fine uneven surface structure. The deviation is 0.3 μm or less, or the standard deviation of the peak-valley interval based on the average height of the unevenness is 10 μm or less. An example is shown in FIG. FIG. 1
(A) illustrates the height H of the convex portion 12 with the depth of the deepest valley portion 11 as a reference L1, and FIG. 1 (b) illustrates the peak and valley with the average height of the unevenness as a reference L2. This is an explanation of the interval S.

The non-glare layer can be formed by a method of roughening the surface of the transparent resin layer to a predetermined state by an appropriate method such as embossing or buffing, but it is more transparent than the formation efficiency. The method of forming with a transparent resin containing fine particles is preferable. As the transparent fine particles, for example, silica and alumina, titania and zirconia, tin oxide and indium oxide,
One or two or more of appropriate ones which are insoluble in a combined resin and the like, such as inorganic particles which may be conductive, such as cadmium oxide and nonmonium oxide, and organic particles which are formed of a crosslinked or uncrosslinked polymer. Can be used. Particularly, those having excellent transparency are preferable. The average particle size of the transparent fine particles is
15 from the viewpoint of the ease of forming the surface
μm or less, preferably 0.1 to 10 μm, particularly preferably 0.5 to 5 μm.

As the transparent resin for containing the transparent fine particles, one or more suitable resins having excellent transparency can be used. Incidentally, examples thereof include acetate resins and carbonate resins, arylate resins and sulfone resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyether sulfone resins and polyamide resins, polyimide resins and styrene resins. And olefin-based resins such as cyclic polyolefins, acrylic resins, fluorine-based resins, and resins such as acrylics, urethanes, acrylic urethanes, epoxies, and silicones that are cured by heat or ultraviolet rays. Curable resins are more preferably used than hard coat properties or scratch resistance for the purpose of preventing scratches on the surface.

The formation of the non-glare layer using the transparent fine particles is carried out, for example, by forming a transparent resin containing the transparent fine particles into a film by an appropriate method such as an extrusion molding method, or by applying a liquid of the transparent resin containing the transparent fine particles and drying. In the case of a curable resin, use a method suitable for the resin type, such as a method in which transparent fine particles are blended with the monomer resin and applied, followed by a curing treatment. Can be. The amount of the transparent fine particles can be appropriately determined from the viewpoint of non-glare properties and the like, but is generally 50 parts by weight or less per 100 parts by weight of the transparent resin, preferably 2 to 40 parts by weight, particularly 5 to 5 parts by weight.
30 parts by weight.

In the above, according to the present invention, as shown in FIG. 1A, based on the height H of the convex portion 12 with the depth of the deepest valley portion 11 as a reference L1, the height of the convex portion group is determined. Of the surface fine unevenness having a standard deviation of 0.3 μm or less, or a peak-to-valley interval S with the average height of the unevenness as a reference L2 as shown in FIG.
Is a surface fine uneven structure having a standard deviation of 10 μm or less. This makes it possible to form a non-glare layer that can suppress the occurrence of glare while effectively preventing the reflection of the outside scene by forming a fine surface uneven structure that does not reduce the sharpness of a high-definition image due to a reduction in pixel size or the like. .

If the standard deviation of the height of the projections exceeds 0.3 μm, or if the standard deviation of the peak-to-valley interval exceeds 10 μm, glare tends to occur. A concave-convex structure that is preferable from the viewpoint of suppressing glare is one in which the dispersion of the height or / and the peak-to-valley interval of the group of protrusions is as small as possible, and especially the standard deviation of the height of the protrusions is 0.20 μm or less, particularly 0.1 μm or less. It has a standard deviation of 15 μm or less and / or a peak-valley interval of 8 μm or less, particularly 6 μm or less.

The thickness of the transparent resin layer can be appropriately determined depending on the formability of the above-mentioned fine surface unevenness structure, but is generally 1 to 30 μm, preferably 2 to 20 μm, from the viewpoint of scratch resistance and thinning.
μm, especially 5 to 10 μm.

The non-glare layer may be provided directly on a display device to which the device is applied, a method for directly providing the display device with a member such as a polarizing plate or an elliptically polarizing plate, or an antiglare sheet provided on the surface of a transparent film substrate. One or two or more layers can be provided at appropriate places on the surface of the display device or the like by an appropriate method such as a method of providing the display device directly or on a member forming the display device.

In the above, as the transparent film substrate for supporting the non-glare layer, one or two or more of appropriate ones such as the transparent resin exemplified in the above-mentioned non-glare layer can be used. There is no particular limitation. Above all, those made of a resin having excellent transparency, mechanical strength, heat stability, water resistance and the like are preferable.

The thickness of the transparent film substrate can be appropriately determined according to the strength and light transmittance. Generally 500 μm or less, especially 10-30
The thickness is 0 μm, especially 15 to 200 μm. The surface of the transparent film substrate may be subjected to an appropriate treatment such as a corona treatment, an ultraviolet irradiation treatment, a plasma treatment, a sputter etching treatment, an undercoat treatment, etc. for the purpose of improving the adhesion of a layer attached thereto. .

On the other hand, as a polarizing plate or an elliptically polarizing plate to which the above-mentioned non-glare layer is attached as an antiglare sheet as required, a polarizing film or a polarizing film protected by a transparent protective layer, and a retardation plate and a polarizing film are laminated. A suitable device used for forming a liquid crystal display device or the like can be used, and the type is not particularly limited.

Incidentally, as a specific example of the polarizing film, iodine and / or diamine is added to a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, and an ethylene / vinyl acetate copolymer-based partially saponified film. Examples thereof include stretched films obtained by adsorbing a chromatic dye, and oriented polyene films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride. The transparent protective layer provided as necessary on one side or both sides of the polarizing film may be formed by using an appropriate material such as the transparent resin exemplified in the above non-glare layer, an appropriate method such as a coating method or a laminating method of a film. Can be formed.

Examples of a retardation plate for obtaining an elliptically polarizing plate by laminating with a polarizing plate include suitable polymers such as polycarbonate, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polypropylene, other polyolefins, polyarylate and polyamide. A birefringent film obtained by stretching a film made of, a liquid crystal polymer having been subjected to an alignment treatment, and an alignment layer thereof supported by a transparent film substrate. The retardation plate may be one in which two or more kinds of retardation films or the like are laminated to control optical characteristics such as retardation.

The non-glare layer may be provided on one or both sides of the transparent film substrate, the polarizing plate, or the elliptically polarizing plate as described above, and one or more layers may be provided at appropriate positions on the display device.
When applied to the display device, it can be applied in a state where an appropriate optical layer such as an anti-reflection layer is provided.
The same applies to a case where an optical member is formed by providing a non-glare layer on an appropriate member.

The anti-reflection layer is provided for the purpose of suppressing surface reflection of external light. For example, the anti-reflection layer may be formed of a multilayer coating film of an inorganic oxide having a different refractive index or a coating film of a low refractive material such as a fluorine compound. It can be formed on the non-glare layer as an interference film or the like. In addition, for example, when a non-glare layer is used as an anti-reflection layer that reflects a fine uneven structure on the lower surface by an appropriate coating method such as a vapor deposition method such as a vacuum deposition method or an ion plating method, a sputtering method, a plating method or a sol-gel method, or the like. It can also serve as a combination.

Further, the non-glare layer and the optical member may be provided with a transparent conductive layer for the purpose of preventing static charge and shielding electromagnetic waves. The transparent conductive layer may be one layer or two layers at an appropriate place inside or on the surface of the layer forming the transparent film substrate or the optical member.
More than one layer can be provided. The formation of the transparent conductive layer includes, for example, a coating method of a transparent conductive paint, a vacuum deposition method and a sputtering method of a conductive material, an ion plating method and a chemical vapor deposition method, a spray pyrolysis method and a chemical plating method, an electroplating method and the like. It can be performed by an appropriate method such as a combined method.

The conductive materials include, for example, indium oxide and tin oxide, indium / tin mixed oxide and cadmium oxide, titanium oxide and indium, tin and gold, silver and platinum,
Appropriate materials such as palladium and copper, aluminum and nickel, chromium and titanium, iron and cobalt, copper iodide and their alloys can be used alone or in combination of two or more, and there is no particular limitation, and any of known materials is used. sell.

Further, on the surface of the non-glare layer or the optical member, a fluorine-based surface treatment coat can be provided for the purpose of making it difficult for stains such as fingerprints to adhere, and for facilitating the wiping of the adhered stains. In forming the coat, an appropriate fluorine-based compound that can form a film having a small surface energy, such as a fluorine-based resin or a fluorine-based silane coupling agent, can be used.

In addition, an adhesive layer may be provided on one or both surfaces of the antiglare sheet or the optical member, particularly on the surface having no non-glare layer, for the purpose of bonding to other members. For forming the pressure-sensitive adhesive layer, a pressure-sensitive adhesive having a base polymer of an appropriate polymer such as an acrylic polymer, a silicone-based polymer, polyester, polyurethane, polyether, or synthetic rubber can be used, and is not particularly limited. Among them, those having excellent optical transparency such as acrylic pressure-sensitive adhesives and exhibiting adhesive properties such as appropriate wettability, cohesiveness and adhesiveness are preferable,
In addition, those having excellent weather resistance and heat resistance are particularly preferable.

Incidentally, examples of the above-mentioned acrylic pressure-sensitive adhesive include an alkyl group having 20 or less carbon atoms such as a methyl group, an ethyl group, a butyl group, and an ethylhexyl group (meth).
Acrylic polymer using one or more alkyl ester of acrylic acid as a main component, and one of appropriate monomer components other than acrylic acid alkyl ester for the purpose of improving adhesive properties as required. Examples of the base polymer include those obtained by copolymerizing a kind or two or more kinds.

The attachment of the pressure-sensitive adhesive layer to the transparent film substrate, the optical member, or the like can be performed, for example, by directly applying the pressure-sensitive adhesive liquid on the transparent film substrate or the like by an appropriate developing method such as a casting method or a coating method. Alternatively, it can be performed by an appropriate method such as a method of forming an adhesive layer on a separator and transferring it onto a transparent film substrate or the like according to the above. The thickness of the adhesive layer can be appropriately determined according to the adhesive force and the like, and is generally 1 to 500 μm.
It is said.

If necessary, the adhesive layer may contain, for example, natural or synthetic resins, especially, tackifying resins, fillers, pigments, coloring agents, and antioxidants. Alternatively, a transparent particle may be blended to form an adhesive layer exhibiting light diffusion. Further, the adhesive layer can be provided as a superimposed layer of different compositions or types. When the adhesive layer is exposed on the surface, it is preferable to cover and protect the surface with a separator or the like until practical use.

The non-glare layer, the transparent film substrate, and the optical member are treated with an ultraviolet absorber such as a salicylate compound, a benzophenone compound, a benzotriazole compound, a cyanoacrylate compound, or a nickel complex salt compound. UV absorption ability can be imparted by such means. The non-glare layer and the optical member according to the present invention can be applied to various display devices such as a CRT, a plasma display, and a liquid crystal display device.

[0029]

EXAMPLE 1 Spherical transparent fine particles having an average particle size of 2 μm were added to 100 parts (parts by weight, the same applies hereinafter) of an ultraviolet-curable polyfunctional acrylic monomer.
7 parts, 3 parts of a photopolymerization initiator and an organic solvent were mixed and mixed with a homogenizer, and a dispersion having a solid content concentration of 50% by weight was applied to one surface of a 50 μm-thick triacetyl cellulose film by a bar coater, and then passed through a high-pressure mercury lamp. An antiglare sheet was obtained by forming a non-glare layer having a thickness of 8 μm by curing treatment with ultraviolet rays. The result of measuring the surface fine unevenness structure of this anti-glare sheet with a surface roughness meter and examining the height of the convexity based on the depth of the deepest valley on any continuous straight line from the recording of the surface unevenness shape , The standard deviation of the height of the convex group is 0.12 μm.
m.

An adhesive layer was provided on the back surface of the anti-glare sheet, and the mask pattern was adhered to a glass plate and fixed on a light table via a non-glare layer on the surface. Was less likely to occur. Further, when the antiglare sheet was applied to a color TFT liquid crystal display device of high definition image quality, no reduction in image clarity was observed, and there was no reflection of the outside scenery and the antiglare effect was excellent.

Example 2 Example 1 except that the amount of the spherical transparent fine particles was changed to 20 parts.
An anti-glare sheet was obtained according to the following. The surface irregularity structure of this anti-glare sheet was measured with a surface roughness meter, and from the recording of the surface irregularity shape, the peak-to-valley interval was determined based on the average height of the irregularities on an arbitrary continuous straight line. Is 5.82
μm. When the mask pattern of this antiglare sheet was visually recognized in accordance with the above, glare was less generated than in the conventional antiglare sheet. Further, when the antiglare sheet was applied to a color TFT liquid crystal display device of high definition image quality, no reduction in image clarity was observed, and there was no reflection of the outside scenery and the antiglare effect was excellent.

Comparative Example 1 The standard deviation of the height of the convex group was 0.58 μm according to Example 1.
Obtaining the anti-glare sheet and visually observing the mask pattern,
More glare occurred than in Example 1.

Comparative Example 2 An anti-glare sheet having a standard deviation of peak-to-valley spacing of 22.3 μm was obtained in accordance with Example 2 and the mask pattern was visually observed. As a result, more glare occurred than in Example 2.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a height (a) of a convex portion and a gap between peaks and valleys (b).

[Explanation of symbols]

 11: deepest valley 12: convex L1, L2: standard H: convex height S: peak-valley spacing

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Shibata 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Tomomori Masada 1-1-1, Shimohozumi, Ibaraki-shi, Osaka No. 2 Nitto Denko Corporation F term (reference) 2H042 BA04 BA20 2K009 AA12 BB11 CC03 CC09 DD02 DD03 EE03

Claims (3)

[Claims] 1. A transparent resin layer having a fine uneven structure on the surface, wherein a standard deviation of a height of a convex portion with respect to a depth of a deepest valley in the fine uneven structure on the surface is 0.3 μm or less, or A non-glare layer, wherein a standard deviation of a peak-to-valley interval based on an average height of unevenness is 10 μm or less. 2. The non-glare layer according to claim 1, wherein the fine uneven structure on the surface is based on the inclusion of transparent fine particles. 3. An optical member comprising the non-glare layer according to claim 1 on at least one side of a transparent film substrate, a polarizing plate or an elliptically polarizing plate.