JPH09193333A - Anti-glare film - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide an antiglare film having excellent resolution and contrast of characters and images displayed on a display screen, that is, excellent transmission clarity. The present invention provides an antiglare film having an antiglare layer having an uneven surface on a transparent substrate, wherein the uneven surface is a substantially flat surface, and recesses are isolated and distributed.
And the average interval (Sm) 60 to 18 of the unevenness of the uneven surface
0 μm, center line average roughness (Ra) 0.05 to 0.2, gloss 60 to 80%, haze 3 to 8%, transmission clarity 2
00 or more, in particular, the antiglare layer is formed of an ionizing radiation-curable resin, and the antiglare layer is an agent in which fine particles having a particle size of 0.05 to 5 μm are dispersed at least in the vicinity of the surface. Made of mold film,
By using, it is possible to provide an antiglare film having the above-mentioned problems and having scratch resistance and improved transmission clarity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antiglare film used for the surface of various displays such as CRT displays, liquid crystal displays and plasma displays, especially for the surface of high definition displays.

[0002]

2. Description of the Related Art Conventionally, the surface of a display or the like has been subjected to an antiglare treatment in order to diffuse or reflect light from the outside or inside of the display surface so as not to be dazzled. Such an antiglare treatment is carried out, for example, by coating a resin containing a filler such as silicon dioxide on the display surface or coating a resin containing a filler such as silicon dioxide on a transparent substrate. The base material was attached to the display surface.

In particular, a film-shaped polarizing element which functions as a light shutter is provided on the surface of a display body such as a liquid crystal display. However, since the polarizing element itself is poor in scratch resistance, it is made of glass or transparent. A polarizing plate is formed by being protected by a transparent protective substrate such as a plastic plate or a transparent plastic film. However, since the transparent protective substrate itself made of a plastic such as a transparent plastic plate or a transparent plastic film is also easily scratched, in recent years, such a polarizing plate having a scratch-resistant surface has been developed.

For example, JP-A-1-105738 discloses a triacetate film having excellent scratch resistance, chemical resistance and antiglare property, which is used for forming a polarizing plate by being laminated on a polarizing film. An unsaponified triacetate film provided with a cured coating film of an ultraviolet-curable epoxy acrylate resin on one surface, and in particular, the cured coating film contains an amorphous silica in the ultraviolet-curable epoxy acrylate resin. An antiglare film comprising the composition is disclosed.

However, a cured film having improved scratch resistance and chemical resistance with improved adhesion to a triacetate film can be obtained, which has the advantage of lowering the glossiness. Since it was dispersed in a curable epoxy acrylate resin, there was a drawback that when the amount of amorphous silica was increased to suppress glossiness, the transmittance decreased and the transmission clarity decreased. .

[0006]

The problem to be solved by the present invention is to solve the drawbacks described in the prior art of the present invention and to have excellent resolution and contrast of characters and images displayed on the display screen. That is, it is to provide an antiglare film having excellent transmission clarity and scratch resistance.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have found that in an antiglare film having an antiglare layer having an uneven surface on a transparent substrate, the uneven surface is substantially flat. It is an anti-glare film in which concave portions are isolated and distributed on the surface, and the average spacing (Sm) of the irregularities of the irregular surface is 60 to 180 μm, and the center line average roughness (Ra).
An antiglare film having a thickness of 0.05 to 0.2 μm, a gloss of 60 to 80%, a haze value of 3 to 8%, and a transmission clarity of 200 or more, and particularly, the antiglare layer is an ionizing radiation curable type. Formed of a resin, the antiglare layer formed of a shaped film, and the shaped film is a thermoplastic resin in which fine particles having a particle diameter of 0.05 to 5 μm are dispersed at least near the surface. By using an anti-glare film that is an extrusion-molded film made of a resin, and that the shaped film is a co-extruded biaxially stretched polyester film of fine particle-dispersed polyester and polyester, light shielding is performed inside the film. The present invention has found an antiglare film having excellent transmission clarity and scratch resistance because it can exhibit an antiglare effect without lowering the transmittance because there is no fine particle that becomes a transparent film. Was completed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to an antiglare film having an antiglare layer having an uneven surface on a transparent substrate, wherein the uneven surface is a substantially flat surface and concave portions are distributed independently from each other. It is a feature.

Further, the average spacing (Sm) between the irregularities on the irregular surface.
60 to 180 μm, center line average roughness (Ra) 0.05 to
The value is 0.2, the gloss is 60 to 80%, the haze value is 3 to 8%, and the transmission clarity is 200 or more.

The antiglare layer formed of an ionizing radiation curable resin is effective for scratch resistance.

Further, it is preferable that the antiglare layer is formed of a patterned film. It is preferable that the shape-imparting film is an extrusion-molded film made of a thermoplastic resin in which fine particles having a particle diameter of 0.05 to 5 μm are dispersed at least near the surface.

Further, it is preferable that the shaped film is a coextrusion-molded biaxially stretched polyester film of fine particle-dispersed polyester and polyester.

Any transparent plastic film can be used as the transparent substrate of the present invention. For example, triacetyl cellulose, acetyl cellulose butyrate film, polyethylene film, polypropylene film, polystyrene film, polyester film. , A polycarbonate film, a polyacrylic resin film, a (meth) acrylonitrile film, a polyurethane resin film, a polyvinyl alcohol film, a polyvinyl chloride film, a polysulfone film, a polyether sulfone film, a polymethylpentene film, and the like. In particular, triacetyl cellulose film and uniaxially stretched polyethylene terephthalate film are excellent in film strength and transparency,
It is preferably used because it has no optical anisotropy. Its thickness is about 8 to 1000 μm.

As the antiglare layer of the present invention, a transparent resin can be used, and for example, a thermoplastic resin, a thermosetting resin, an ionizing radiation curable resin or the like can be used. By setting the thickness of the antiglare layer to 0.5 μm or more, preferably 3 μm or more, scratch resistance can be imparted.

In order to further improve the scratch resistance of the antiglare layer, the transparent resin used for the antiglare layer is a reactive curable resin, that is, a thermosetting resin and / or an ionizing radiation curable resin. It is preferable to use a resin or the like. The thermosetting resin, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea co-condensation resin, silicon resin,
A polysiloxane resin or the like is used, and if necessary, a crosslinking agent, a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier, etc. are added and used.

As the ionizing radiation curable resin, a polymer, a prepolymer or a monomer which undergoes a cross-linking polymerization reaction or the like by ionizing radiation to be solidified is used. Specifically, a radical polymerization system comprising a compound having a (meth) acryloyl group such as (meth) acrylamide, (meth) acrylonitrile, (meth) acrylic acid, (meth) acrylic acid ester (here, (meth) acryloyl) Means acryloyl or methacryloyl), epoxy, cyclic ether, cyclic acetal, lactone, vinyl monomer, cyclic siloxane and aryldiazonium salt,
Cationic polymerization system composed of a combination with a diaryl iodonium salt, etc., a compound having a thiol group, for example, trimethylolpropane trithioglycolate, trimethylolpropane tripropylate, polyene / thiol system composed of pentaerythritol tetrathioglycol and a polyene compound. Etc. can be used.

A radical generator or an oxygen absorber may be added as a reaction accelerator for the ionizing radiation curable resin. Further, as a photoreaction initiator in the case of curing by ultraviolet rays,
Benzoin, benzoin methyl ether, acetophenone, benzophenone, Michler's ketone, diphenyl sulfide, dibenzyl sulfide, diethyl oxide, triphenyl biimidazole, isopropyl-N,
One kind or two or more kinds of N-dimethylaminobenzoate and the like, relative to 100 parts by weight of the ionizing radiation curable resin,
0.1 to 10 parts by weight can be mixed and used.

Further, a thermoplastic resin may be added to the above ionizing radiation curable resin, if necessary. For example,
Examples thereof include polyethylene, polystyrene, polymethyl methacrylate, polybutyl methacrylate and the like. Also,
Fillers such as calcium carbonate, silica, alumina, etc., viscosity reducing agents, leveling agents, colorants, bright pigments, etc. may be added. Further, wax, silicone, a fluorine-based compound, a reactive compound such as silicon acrylate or fluorinated acrylate, and the like can be added.

In the method of forming an uneven surface on the surface of the antiglare layer in the method for producing an antiglare film of the present invention, an imprint film having fine irregularities on the surface is used for imprinting or And / or by applying a coating material in which a matting agent such as fine particles is added to a binder to form a coating film, or by using the above-described shaping and addition of a matting agent in combination. it can. When fine irregularities are formed on the surface by a mold without using a matting agent for imparting antiglare property, the effect of not particularly impairing transparency is exhibited.

As a method for producing the antiglare film of the present invention by patterning, a transparent base material is coated with a coating liquid containing a transparent resin, the solvent is dried and removed, and at least it has flexibility. The shape-imparting film having a fine uneven surface on one surface thereof is superposed on the above-mentioned transparent resin coated surface, and the shape is applied by pressure and / or heating, and then the shape-imparting film is peeled and removed. The above coating liquid may be applied to the uneven surface of the patterning film. Similarly to the above, after drying the solvent of the coating liquid, the transparent base materials are superposed and the same procedure as above is performed.

When the transparent resin is a reaction curable resin, a transparent base material is coated with a coating liquid containing the reaction curable resin, and the solvent is dried and removed.
A shaped film having a fine uneven surface on one side thereof, superposed on the coated surface of the reaction curable resin, through a transparent substrate, or through the shaped film, after curing by heat treatment or ionizing radiation irradiation, The patterning film is peeled and removed. The above coating liquid may be applied to the uneven surface of the shape-imparting film, and after drying the solvent of the coating solution similar to the above, the transparent substrates are superposed, and the following curing and peeling of the shape-imparting film are as described above. Follow the same procedure.

When the transparent resin is an ionizing radiation curable resin, a transparent base material is coated with a coating liquid containing the ionizing radiation curable resin, and the solvent is dried and removed. , A shape-imparting film having a fine uneven surface on one surface thereof, superposed on the coating surface of the ionizing radiation-curable resin, through a transparent substrate, or through the shape-imparting film, after being cured by irradiation with ionizing radiation Then, the patterning film is peeled and removed. The above coating liquid may be applied to the uneven surface of the shape-imparting film, and after drying the solvent of the coating solution like the above, the transparent base materials are superposed, and thereafter curing by irradiation of ionizing radiation and peeling of the shape-imparting film. Is performed in the same procedure as above.

In the present invention, ionizing radiation means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing or cross-linking molecules, such as visible rays, ultraviolet rays, X-rays and the like. There are electromagnetic waves or particle beams such as electron beams, but ultraviolet rays or electron beams are usually used.

As an ionizing radiation irradiation device used for curing the ionizing radiation curable resin of the present invention, when irradiating with ultraviolet rays, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a black light lamp, a metal halide lamp. You can use a light source such as. Also, when irradiating with an electron beam, Cockloft Wald type, Banderaf type, resonant transformer type, insulating core transformer type,
Alternatively, various types of electron beam accelerators such as linear type, dynamitron type, and high frequency type are used. When irradiating with an electron beam,
Usually 100 to 1000 KeV, preferably 100 to 3
0.1 to 30 Mr of electrons having an energy of 00 keV
Irradiate with a dose of about ad.

As a method of applying the ionizing radiation curable resin to the transparent substrate, gravure, gravure reverse,
Examples include roll coat and comma coat. The viscosity of the ionizing radiation curable resin at the time of coating is 1000 c
It is preferably ps or less. Both use as a solventless type containing no volatile solvent and use of a volatile solvent can be selected. Therefore, in the case of a solventless type, a method of heating an ionizing radiation curable resin having a high viscosity at room temperature at about 40 ° C. to 70 ° C. to lower the viscosity to 1000 cps or less can be adopted.

The shape-imparting film has a fine uneven surface formed by applying a coating liquid containing fine particles onto a base film, or a fine uneven surface formed directly on the plastic film surface by a sand blast method or the like. A layer is formed, a fine uneven layer is formed on the surface of a plastic film in which fine particles are dispersed in a thermoplastic resin and extruded, and a mold having a fine uneven surface formed by etching or plating is used. A film made of a thermoplastic resin having fine irregularities formed by heating and pressing, or a mold having the above-mentioned fine irregularities is used to pour an ionizing radiation-curable resin and cure it by irradiation with ionizing radiation. It is possible to use, for example, those provided with a fine uneven surface by molding.

Of these, when the shaped film is an extruded film made of a thermoplastic resin in which fine particles having a particle size of 0.05 to 5 μm are dispersed at least in the vicinity of the surface, examples of the thermoplastic resin include ethyl cellulose. , Cellulose nitrate, cellulose acetate, ethyl hydroxycellulose, cellulose derivative such as cellulose acetate propionate, polystyrene, styrene resin or styrene copolymer such as poly α-methylstyrene, polymethyl methacrylate, polyethyl methacrylate, polyacrylic Acrylic resins such as ethyl acetate and polybutyl acrylate, polyvinyl chloride, polyvinyl acetate, vinyl chloride / vinyl acetate copolymers, vinyl polymers such as polyvinyl butyral, rosin, rosin-modified maleic acid resin, rosin-modified phenolic resin, Polymerized rosin etc. Natural or synthetic resins such as rosin ester resin, coumarone resin, vinyltoluene resin, polyamide resin can be used.

The fine particles used in the above-mentioned shaped film include inorganic fine particles such as calcium carbonate, barium sulfate, silica, alumina, glass balloons and shirasu balloons, polyurethane resins, epoxy resins, acrylic resins,
Organic fine particles such as plastic beads such as polyester resin, nylon resin, fluororesin, vinyl chloride resin and vinyl chloride-vinyl acetate copolymer resin can be used.

Further, when the shaped film is a coextrusion-molded biaxially stretched polyester film of fine particle-containing polyester and polyester, the polyester may be an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid or naphthalenedicarboxylic acid, or A polyester produced by polycondensing the ester with ethylene glycol or diethylene glycol, and examples thereof include polyethylene terephthalate, polybutylene terephthalate, and polyethylene-2,6-naphthalate. This polyester may be a homopolymer or a copolymer of the third component.

In the case of the coextrusion-molded biaxially stretched polyester film, as shown in FIG. 2, the fine particle-dispersed polyester film has the same thickness as the average particle diameter of the fine particles, ie, 0.05 to 5 μm. Preferably 0.5-3
μm can be used.

Further, as shown in FIG. 5, the uneven surface having the above-mentioned surface shape is such that concave portions are isolated and distributed on a substantially flat surface.

The surface shape of the antiglare film formed by using the above-mentioned pattern-forming film has an average spacing (S
m) 60 to 180 μm, center line average roughness (Ra) 0.0
It is 5 to 0.2 μm.

Further, the surface shape has a ten-point average roughness (Rz) of 0.4 to 1.4 μm and a maximum height (Rmax).
It is 0.7 to 1.7 μm.

Further, the diameter and height of the concave portion of the above surface shape are respectively not less than the maximum wavelength of the spectrum band of the light used and not more than 100 μm, preferably 0.5 to 5 μm, and 2000 to 2,000 on the substantially flat surface. There are 8000 pieces / mm ² .

A polarizing plate using the antiglare film of the present invention is obtained by laminating the antiglare film on a polarizing element. For this polarizing element, a polyvinyl alcohol film, a polyvinyl formal film, a polyvinyl acetal film, an ethylene-vinyl acetate copolymer saponified film, which is dyed with iodine or a dye and stretched, can be used. In order to increase adhesiveness and to prevent static electricity in this laminating treatment, when the transparent base film of the antiglare film is, for example, a triacetyl cellulose film, the triacetyl cellulose film is saponified. To do. This saponification treatment may be performed before or after applying the hard coat to the triacetyl cellulose film.

FIG. 3 shows an example of a polarizing plate using the antiglare film of the present invention. A laminated body including a triacetyl cellulose film (hereinafter referred to as a TAC film) 3 as a transparent substrate and an antiglare layer 2 in the figure corresponds to the antiglare film of the present invention, and this antiglare film is a polarizing element 8 On the other hand, the other surface of the polarizing element 8 is TA
The C film 9 is laminated. An adhesive is provided between the layers of the polarizing plate, if necessary.

FIG. 4 shows an example of a liquid crystal display device using the antiglare film of the present invention. On the liquid crystal display element 11,
The polarizing plate shown in FIG. 3, that is, a polarizing plate having a layer structure of TAC film / polarizing element / anti-glare film is laminated, and the other surface of the liquid crystal display element 11 has T
A polarizing plate having a layer structure of AC film / polarizing element / TAC film is laminated. In the STN type liquid crystal display device, a retardation plate is inserted between the liquid crystal display element 11 and the polarizing plate. An adhesive layer is provided between the respective layers of the liquid crystal display device as needed.

[0038]

EXAMPLES Next, examples of the antiglare film of the present invention will be specifically described.

(Example 1) On a TAC film (FT-UV80 manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm, a multifunctional acrylate UV-curable resin liquid composition having the following composition (manufactured by Dainichi Seika, Seika Beam EXG40-) was used. 13) is applied by a roll coating method so as to be 8 g / m ² after drying, the solvent is removed by heating and drying, and the following polyester film having a fine uneven surface on the surface as a patterning film is laminated on the coated surface, Ultraviolet irradiation from the back side of the patterning film was performed with a mercury lamp 160W2 lamp from a distance of 10 cm at a passing speed of 13 m / min to cure the ultraviolet curable resin. Shaped film: Silica-based fine particles (average particle size 1 to 2 μm)
Polyester film thickness: 25 μm Surface shape: Sm 90 μm, Ra 0.11 μm Next, the patterning film was peeled and removed to obtain an antiglare film. The antiglare film had the following surface shape. Centerline average roughness (Ra): 0.11 μm Average spacing of irregularities (Sm): 90 μm Ten-point average roughness (Rz): 0.9 μm Maximum height (Rmax): 1.2 μm The antiglare film is as follows. Optical characteristics of. Haze: 5% Gloss: 72% Transmission clarity: 273%

The evaluation method in the present invention is as follows.

[Average spacing of irregularities (Sm)] JISB-0
According to 601, the measurement was performed using SEF-30 manufactured by Kosaka Laboratory.

[Center Line Average Roughness (Ra)] JISB-0
According to 601, the measurement was performed using SEF-30 manufactured by Kosaka Laboratory.

[10-point average roughness (Rz)] JISB-06
According to No. 01, it was measured using SEF-30 manufactured by Kosaka Laboratory.

[Maximum Height (Rmax)] JISB-06
According to No. 01, it was measured using SEF-30 manufactured by Kosaka Laboratory.

[Haze (Haze Value)] The haze was measured according to JIS K-7105 using a haze meter manufactured by Toyo Seiki.

[Glossiness] In accordance with JISK-7105,
Murakami Color Research Laboratory GM-30 was used to measure the surface glossiness at a 60-degree angle.

[Transmission sharpness] It was measured according to JISK-7105 using an image measuring device ICM-1DP manufactured by Suga Test Instruments.

[0048]

The present invention is embodied in the form described above and has the following effects.

In an antiglare film having an antiglare layer having an uneven surface on a transparent substrate, the average spacing (Sm) of the unevenness of the uneven surface is 60 to 180 μm, and the center line average roughness (Ra).
0.05-0.2, gloss 60-80%, haze value 3
-8% and a transmission clarity of 200 or more are used for the surface of various displays such as liquid crystal displays, especially for the surface of high-definition displays, and diffuse or reflect light from the outside or inside on the display surface. hand,
You can see a clear and clear image.

Further, since the antiglare layer is formed of an ionizing radiation-curable composition, the surface of the antiglare layer can have scratch resistance, and in particular, polarized light of a display body such as a liquid crystal display. Since the element substrate itself has poor scratch resistance,
The protective layer of such an antiglare film can improve scratch resistance.

Further, since the antiglare layer is formed of a patterning film, the surface shape having the fine uneven surface specified above can be accurately reproduced.

Further, since the shape-imparting film is an extrusion-molded film made of a thermoplastic resin in which fine particles having a particle diameter of 0.05 to 5 μm are dispersed at least in the vicinity of the surface, the fine uneven surface specified above is formed. It is possible to accurately and stably reproduce the surface shape possessed.

Further, the shape-imparting film is a coextrusion-molded biaxially stretched polyester film of fine particle-dispersed polyester and polyester, so that the surface shape having the fine uneven surface specified above, particularly the average interval of the unevenness. (S
m) 60 to 180 μm, center line average roughness (Ra) 0.0
5 to 0.2 μm can be accurately and stably replicated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of an antiglare film of the present invention.

FIG. 2 is a cross-sectional view showing an example of a coextrusion molded biaxially stretched polyester film of a shaped film of the present invention.

FIG. 3 is a cross-sectional view showing an example of a polarizing plate using the antiglare film of the present invention.

FIG. 4 is a cross-sectional view showing an example of a liquid crystal display device using the antiglare film of the present invention.

FIG. 5 is a perspective view showing an embodiment of the antiglare film of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anti-glare film 2 Anti-glare layer 3 Transparent base material 4 Shaped film 5 Fine particles 6 Thermoplastic resin 7 Polarizing plate 8 Polarizing element 9 Transparent base material (TAC film) 10 Liquid crystal display device 11 Liquid crystal display element 12 Recessed portion

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G02B 1/11 G09F 9/00 316Z G09F 9/00 316 7639-4F B29C 55/12 // B29C 55 / 12 G02B 1/10 A B29K 67:00 B29L 9:00

Claims (6)

[Claims] 1. An anti-glare film having an anti-glare layer having an uneven surface formed on a transparent substrate, wherein the uneven surface is a substantially flat surface and recesses are distributed isolated from each other. Anti-glare film to be. 2. An average spacing (Sm) 60 of the irregularities of the irregular surface.
˜180 μm, center line average roughness (Ra) 0.05˜0.
The antiglare film according to claim 1, which has a gloss of 60 to 80%, a haze value of 3 to 8%, and a transmission sharpness of 200 or more. 3. An antiglare film, characterized in that the antiglare layer according to claim 1 is formed of an ionizing radiation curable resin. 4. An antiglare film, characterized in that the antiglare layer according to any one of claims 1 to 3 is formed of a patterning film. 5. The antiglare film, wherein the shaped film according to claim 4 is an extruded film made of a thermoplastic resin in which fine particles having a particle diameter of 0.05 to 5 μm are dispersed at least near the surface. . 6. An antiglare film, wherein the patterning film according to claim 5 is a coextrusion molded biaxially stretched polyester film of fine particle dispersed polyester and polyester.