JP2000194272A - Glare-proof shielding film having antifouling property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glare-proof shielding film excellent in antifouling property without lowering various performances peculiar to the film by forming a glare- proof shielding layer having ruggedness as the top layer. SOLUTION: One or more resin layers are laminated on a transparent base film 12 and a glare-proof shielding layer 18 having ruggedness is formed as the top layer to obtain the objective glare shielding film 10. The surface of the glare shielding layer 18 has antifouling property. The layer 18 is formed by using a resin composition curable with ionizing radiation and containing a fluorine modified compound such as a perfluoroalkylsulfonate monomer or oligomer. Since the fluorine modified monomer or oligomer is polymerized and cured together with the resin composition, superior antifouling property is maintained even after alkali treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer, a word processor, and a television set for displaying images.
The present invention relates to an antiglare film provided on the surface of a high-definition image display such as an RT and a liquid crystal panel, a polarizing film using the antiglare film, and a transmission type display device.

[0002]

2. Description of the Related Art In such a display, if light emitted mainly from the inside goes straight without diffusing on the display surface, the light emitted from the inside is diffused to some extent because it is dazzling when the display surface is visually observed. Is provided on the display surface.

This anti-glare film is disclosed in, for example,
As disclosed in JP-A-18706 and JP-A-10-20103, the transparent base film is formed by applying a resin containing a filler such as silicon dioxide (silica) to the surface.

[0004] These antiglare films are of a type in which irregularities are formed on the surface of the antiglare layer by agglomeration of particles such as cohesive silica, and an organic filler having a particle size larger than the thickness of the coating film is added to the resin. There is a type in which an uneven shape is formed on the surface of the layer, or a type in which a film having unevenness is laminated on the surface of the layer to transfer the uneven shape.

[0005]

The conventional anti-glare film as described above has a certain level of antifouling property in which silicone oil is added as a leveling agent when the surface layer is formed. Fingerprint attachment,
There is a problem that the antifouling property against other lipophilic substances is insufficient, and the quality of the displayed image is deteriorated when the surface is soiled.

Further, the antiglare film for the polarizing film uses a triacetate cellulose film as a transparent base film. After forming a necessary layer on the base film, a saponification treatment is carried out with an aqueous alkali solution to obtain a polarizing polyvinylidene. It is manufactured by laminating with an alcohol film and an adhesive.At this time, the silicone oil which is usually used as a leveling agent and is present on the outermost surface is decomposed and removed by the alkali treatment. There is a problem that it loses its antifouling property at all and is easily contaminated by, for example, fingerprints, plasticizers, other oils, etc., and the quality of the displayed image is further reduced.

Accordingly, an object of the present invention is to solve the above-mentioned conventional problems and to provide an antiglare film having excellent antifouling properties without deteriorating various performances as an antiglare film, and a polarizing plate using the antiglare film. And a transmissive display device.

[0008]

The above object is achieved by the present invention described below. That is, the present invention is an anti-glare film in which at least one or more resin layers are laminated on a transparent base film, and the uppermost layer is an anti-glare layer having irregularities, wherein the surface of the anti-glare layer is anti-glare. Provided are an anti-glare film having a stain, a polarizing plate using the anti-glare film, and a transmission type display device.

In the present invention, it has been found that, in order for the antiglare film to have a significant antifouling property, the contact angle of the surface with triacetin is preferably> 43 deg. Further, they have found that the above antifouling property can be achieved by including a fluorine-modified compound in the antiglare layer. Also, when the base film is a triacetate film, it has been found that even after alkali-treating the antiglare film, the antiglare layer can maintain the contact angle to triacetin at> 43 deg by including the fluorine-modified compound in the antiglare layer. Was.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, an antiglare film 10 according to an embodiment of the present invention includes, as shown in FIG. 1, at least one or more resin layers laminated on a transparent base film 12 and an uppermost layer having an antiglare layer 18 having irregularities. The anti-glare film is characterized in that the surface of the anti-glare layer has antifouling properties.

As a material of the transparent base film 12, there are a transparent resin film, a transparent resin plate, a transparent resin sheet and a transparent glass. Examples of the transparent resin film include a triacetate cellulose (TAC) film, a polyethylene terephthalate (PET) film, a diacetyl cellulose film, an acetate butyrate cellulose film, a polyether sulfone film, a polyacrylic resin film, a polyurethane resin film, a polyester film, Polycarbonate films, polysulfone films, polyether films, polymethylpentene films, polyetherketone films, (meth) acrylonitrile films, and the like can be used. The thickness is usually about 25 μm to 1000 μm.

As the transparent base film 12, a TAC having no birefringence can be used to form a polarizing plate by laminating an anti-glare film with a polarizing element (described later). It is particularly preferable because a liquid crystal display device having excellent display quality can be obtained.

In the present invention, at least one or more resin layers are laminated on the transparent substrate film 12, and an antiglare layer 18 having irregularities on the uppermost layer and having an antifouling property is formed. can get. This antiglare layer 18 can be formed from the light-transmitting fine particles 16 and the light-transmitting resin 14 containing a fluorine-modified compound. As the translucent resin 14, three types of resins mainly cured by ultraviolet rays and electron beams, that is, ionizing radiation-curable resin, a mixture of ionizing radiation-curable resin with a thermoplastic resin and a solvent, and a thermosetting resin Is used.

The film-forming component of the ionizing radiation-curable resin composition preferably has an acrylate functional group, for example, a polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin having a relatively low molecular weight. , Alkyd resins, spiro acetal resins, polybutadiene resins, polythiol polyene resins, oligomers or prepolymers of polyfunctional compounds such as polyhydric alcohols such as (meth) acrylates, and ethyl (meth) acrylate and ethylhexyl (meth) as reactive diluents Monofunctional monomers such as acrylate, styrene, methylstyrene, N-vinylpyrrolidone and polyfunctional monomers, for example, polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di ( TA) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, etc. Those containing a relatively large amount can be used.

Further, in order to make the above-mentioned ionizing radiation-curable resin composition into an ultraviolet-curable resin composition, acetophenones, benzophenones, Michler benzoyl benzoate, α-amyloxime ester, as photopolymerization initiators may be used. Tetramethyl turum monosulfide, thioxanthones, and n-butylamine, triethylylamine, poly-n-butylphosphine, and the like as photosensitizers can be used in combination. In particular, in the present invention, it is preferable to mix urethane acrylate as an oligomer and dipentaerythritol hexa (meth) acrylate as a monomer.

Further, as the light-transmitting resin 14 for forming the antiglare layer 18, a solvent-drying resin may be contained in the ionizing radiation-curable resin as described above. As the solvent drying type resin, a thermoplastic resin is mainly used.
As the type of the solvent-drying type thermoplastic resin to be added to the ionizing radiation-curable resin, a commonly used type is used. Particularly, when a cellulose-based resin such as TAC as described above is used as the transparent substrate film 12, ionizing radiation is used. Cellulose resins such as nitrocellulose, acetylcellulose, cellulose acetate propionate, and ethylhydroxyethylcellulose are advantageous as the solvent-drying resin contained in the curable resin in terms of adhesion and transparency of the coating film.

The reason is that when toluene is used as the solvent for the above-mentioned cellulose resin, the transparent base film 1
Despite the use of toluene, which is a solvent insoluble in polyacetylcellulose being 2, the transparent substrate film 12
Even if a coating containing the solvent-drying type resin is applied to the transparent substrate film, the adhesion between the transparent substrate film 12 and the coating resin can be improved, and the toluene can be used as the transparent substrate film of polyacetyl. This is because since the cellulose is not dissolved, the surface of the transparent substrate film 12 does not whiten, and there is an advantage that transparency is maintained.

The light-transmitting fine particles 16 contained in the anti-glare layer 18 are preferably plastic beads, and are particularly high in transparency and require a difference in refractive index from the matrix resin (light-transmitting resin 14). Are preferred. As plastic beads, melamine beads (refractive index 1.5
7), acrylic beads (refractive index: 1.49), acrylic
Styrene beads (refractive index 1.54), polycarbonate beads, polyethylene beads, polystyrene beads, PVC beads, and the like are used. As described above, the particle size of these plastic beads is appropriately selected and used from 0.5 to 5 μm.

When the above-mentioned light-transmitting fine particles 16 as an organic filler are added, the organic filler easily precipitates in the resin composition (light-transmitting resin 14). May be added.
In addition, the more the inorganic filler is added, the more effective it is to prevent the sedimentation of the organic filler, but it has a bad influence on the transparency of the coating film. Therefore, it is preferable to prevent sedimentation by adding an inorganic filler having a particle size of 0.5 μm or less to the translucent resin 16 in an amount of less than 0.1% by weight so as not to impair the transparency of the coating film. Can be. When not adding an inorganic filler which is an anti-settling agent for preventing settling of an organic filler,
When the organic filler is applied to the transparent base material film 12, the organic filler is precipitated at the bottom.

In the present invention, an antiglare layer is formed on the transparent substrate film using the antiglare layer forming composition obtained by adding a fluorine-modified compound to the above antiglare layer forming composition. Thereby, the antiglare film of the present invention is obtained. Examples of the fluorine-modified compound include perfluoroalkylsulfonic acid salts and perfluoroalkylcarboxylate monomers, oligomers, and polymers. Of these, fluorine-modified monomers and fluorine-modified oligomers are preferable.

Since such a fluorine-modified monomer or fluorine-modified oligomer is polymerized and cured together with the ionizing radiation-curable resin composition, it is not removed by alkali-treating the obtained antiglare film later. Excellent antifouling properties are maintained. The amount of the fluorine-modified compound used is:
It is preferably used in the range of about 0.5 to 1.0 part by weight per 100 parts by weight of the solid content of the composition for forming an antiglare layer. If the amount is less than the above range, satisfactory antifouling property cannot be obtained, and the contact angle of the antiglare layer or the antiglare layer after alkali treatment with triacetin cannot be set to> 43 deg. On the other hand, even when the amount used exceeds the above range, the contact angle cannot be further improved, and the hardness of the antiglare layer is undesirably reduced.

As for the method of curing the ionizing radiation-curable resin composition containing the above-mentioned fluorine-modified compound, the method of curing the ionizing radiation-curable resin composition is a usual curing method, that is, irradiation of electron beam or ultraviolet rays. Can be cured. For example, in the case of the electron beam curing, 50 is emitted from various electron beam accelerators such as Cockloft-Walton type, Handigraph type, Resonant transformation type, Insulating core transformer type, Linear type, Dynamitron type, High frequency type. An electron beam or the like having an energy of １０００1000 KeV, preferably 100-300 KeV is used.
Ultraviolet rays emitted from light rays such as a high-pressure mercury lamp, a low-pressure mercury lamp, a carbon arc, a xenon arc, and a metal halide lamp can be used.

Here, the ionizing radiation-curable resin generally has a refractive index of about 1.5, which is about the same as that of glass. However, compared to the refractive index of the translucent particles, the resin used has a lower refractive index. In this case, TiO ₂ (refractive index; 2.3 to 2.7), Y ₂ , which is fine particles having a high refractive index, is added to the translucent resin 14.
O ₃ (refractive index; 1.87), La ₂ O ₃ (refractive index; 1.9)
5) ZrO ₂ (refractive index; 2.05), A1 ₂ O ₃ (refractive index; 1.63), etc. are added to such an extent that the diffusivity of the coating film can be maintained, and the refractive index can be increased. it can.

Next, on the surface of the transparent substrate film 12,
The process of forming the antiglare layer 18 will be described with reference to FIG. As shown in FIG. 2B, the fluorine-modified compound and the light-transmitting fine particles 1 are applied to the transparent base film 12 shown in FIG.
6 is applied, and a shaping film 19 having fine irregularities formed on the surface is applied from above the applied layer.
Is laminated so that the surface thereof is in contact with the coating layer (see FIG. 2C). Then, when the light-transmitting resin 14 is an electron beam or an ultraviolet curable resin, these electron beams or ultraviolet rays are applied. Irradiation through the mold film 19, and in the case of a solvent drying type resin, after heating and curing,
9 is peeled off from the cured antiglare layer 18.

By doing so, the anti-glare layer 18 becomes a smooth state as a whole, and fine irregularities formed in advance on the molding film 19 are formed. Therefore, the surface of the diffusion layer 18 can be made smoother than in the case where the liquid translucent resin 14 in which the fluorine-modified compound and the translucent fine particles 16 are mixed is simply applied.

Next, an embodiment of the polarizing plate according to the present invention shown in FIG. 3 will be described. As shown in FIG. 3, the polarizing plate 20 of this embodiment is provided with the same anti-glare film 11 as described above on one surface (the upper surface side in FIG. 3) of the polarizing layer (polarizing element) 22. Configuration. The polarizing layer 22 is a two-layer transparent substrate film, TAC.
The film is laminated between the films 12A and 24 and has a three-layer structure. The first layer and the third layer are made of a film obtained by adding iodine to polyvinyl alcohol (PVA), and the intermediate second layer is made of a PVA film. I have. The anti-glare film 11
Has a configuration in which the antiglare layer 18 is laminated on the TAC film 12A.

The TAC provided on both outer sides of the polarizing layer 22 and serving as a transparent substrate film has no birefringence and does not disturb the polarized light. Not done. Therefore, a liquid crystal display device having excellent display quality can be obtained by using such a polarizing plate 20. As the polarizing element constituting the polarizing layer 22 in the polarizing plate 20 as described above, a PVA film dyed and stretched with iodine or a dye, a polyvinyl formal film, a polyvinyl acetal film, an ethylene-vinyl acetate copolymer Film. When laminating the films constituting the polarizing layer 22, in order to increase the adhesiveness and prevent static electricity,
The TAC films 12 and 24 may be subjected to a saponification treatment with an aqueous alkali solution. This alkali treatment is preferably performed at a temperature of about 40 to 80 ° C. for about 60 to 120 seconds using, for example, an alkaline aqueous solution of 2 N potassium hydroxide or sodium hydroxide. Such saponification renders the surface of the TAC film hydrophilic and improves the adhesion to the PVA film.

Next, an example of an embodiment in which the transmissive display device according to the present invention shown in FIG. 4 is a liquid crystal display device will be described. The liquid crystal display device 30 shown in FIG.
Is a transmission type liquid crystal display in which a polarizing plate 32 similar to the polarizing plate 20, a liquid crystal panel 34, and a polarizing plate 36 are laminated in this order, and a backlight 38 is disposed on the back surface on the polarizing plate 36 side. Device.

The liquid crystal modes used in the liquid crystal panel 34 of the liquid crystal display device 30 include a twisted nematic type (TN), a super twisted nematic type (STN), a guest-host type (GH), and a phase transition type (PC). And polymer dispersion type (PDLC). The driving mode of the liquid crystal may be either a simple matrix type or an active matrix type. In the case of the active matrix type, a driving method such as TFT or MIM is employed. Further, the liquid crystal panel 34 may be either a color type or a monochrome type.

[0030]

EXAMPLES Examples of the present invention will be described below in comparison with comparative examples. Example 1 Pentaerythritol triacrylate (PETA) 100 parts by weight Silica filler (secondary particle diameter 1 μm) 7 parts by weight Fluorine-modified acrylic oligomer (DEFENSA MCF-323 manufactured by Dainippon Ink) 1 part by weight Toluene 130 parts by weight

The above materials were mixed to obtain a coating for forming an antiglare layer. This paint was applied on a triacetyl cellulose film (TD-80UV 80 µm, manufactured by Fuji Photo Film) at 3 µm.
The resin was applied so as to have an m / dry, dried, and irradiated with an electron beam to cure the resin. The antiglare film thus obtained had a haze of 13 and a contact angle measurement of 60 ° using triacetin. This film was immersed in a 2N aqueous solution of potassium hydroxide at 60 ° for 90 seconds and saponified, and the contact angle measured using triacetin was 53 °. This antiglare film was excellent in antifouling properties, and no fingerprint was attached even when a finger was pressed against the surface.

Example 2 Pentaerythritol triacrylate (PETA) 100 parts by weight Silica filler (secondary particle diameter 1 μm) 7 parts by weight Fluorine-modified acrylic oligomer (DEFENSA MCF-323 manufactured by Dainippon Ink) 0.2 parts by weight Toluene 130 parts by weight Part The above materials were mixed to obtain a coating for forming an antiglare layer. This paint was applied on a triacetyl cellulose film (TD-80UV, 80 µm, manufactured by Fuji Photo Film) at 3 µm / dry, dried, and irradiated with an electron beam to cure the resin. The anti-glare film thus obtained had a haze of 13, and a contact angle measurement using triacetin of 68 °. This film was immersed in a 2N aqueous solution of potassium hydroxide at 60 ° for 90 seconds and saponified, and the contact angle measured using triacetin was 50 °. This antiglare film was excellent in antifouling properties, and no fingerprint was attached even when a finger was pressed against the surface.

Comparative Example 1 Pentaerythritol triacrylate (PETA) 100 parts by weight Silica filler (secondary particle diameter 1 μm) 7 parts by weight Fluorine-modified silicone (XC98-A5382 manufactured by Toshiba Silicone) 5 parts by weight Toluene 130 parts by weight The above materials are mixed. Thus, a coating for forming an antiglare layer was obtained. This paint was applied on a triacetyl cellulose film (TD-80UV, 80 µm, manufactured by Fuji Photo Film) at 3 µm / dry, dried, and irradiated with an electron beam to cure the resin. The antiglare film thus obtained had a haze of 13 and a contact angle measurement of 7 ° using triacetin. This film was immersed in 2N aqueous potassium hydroxide solution at 60 ° for 90 seconds and saponified, and the contact angle measured using triacetin was 13 °. This antiglare film was inferior in antifouling property, and when a finger was pressed against the surface, a clear fingerprint was attached and the film could not be wiped off.

Comparative Example 2 Pentaerythritol triacrylate (PETA) 100 parts by weight Silica filler (secondary particle diameter 1 μm) 7 parts by weight Fluorine-modified silicone (XC98-A5382 manufactured by Toshiba Silicone) 0.2 part by weight Toluene 130 parts by weight Was mixed to obtain a coating for forming an antiglare layer. This paint was applied on a triacetyl cellulose film (TD-80UV, 80 µm, manufactured by Fuji Photo Film) at 3 µm / dry, dried, and irradiated with an electron beam to cure the resin. The antiglare film thus obtained had a haze of 13 and a contact angle measurement of 35 ° using triacetin. This film was immersed in a 2N aqueous solution of potassium hydroxide at 60 ° for 90 seconds and saponified, and the contact angle measured using triacetin was 39 °. This antiglare film was inferior in antifouling property, and when a finger was pressed against the surface, a clear fingerprint was attached and the film could not be wiped off.

Comparative Example 3 Pentaerythritol triacrylate (PETA) 100 parts by weight Silica filler (secondary particle diameter 1 μm) 7 parts by weight Toluene 130 parts by weight The above materials were mixed to prepare a coating for forming an antiglare layer. This paint was applied on a triacetyl cellulose film (TD-80UV, 80 µm, manufactured by Fuji Photo Film) at 3 µm / dry, dried, and irradiated with an electron beam to cure the resin. The anti-glare film thus obtained had a haze of 13 and a contact angle measurement using triacetin of 43 °. This film was immersed in a 2N aqueous solution of potassium hydroxide at 60 ° for 90 seconds and saponified, and the contact angle measured using triacetin was 38 °. This antiglare film was inferior in antifouling property, and when a finger was pressed against the surface, a clear fingerprint was attached and the film could not be wiped off.

[0036]

According to the present invention, an antiglare film having excellent stain resistance is provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an antiglare film according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a manufacturing process of the anti-glare film.

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

FIG. 4 is a cross-sectional view illustrating a transmission type display device using the antiglare film of the present invention.

[Explanation of symbols]

 10, 11: anti-glare film 12: transparent base film 14: translucent resin 16: translucent fine particles 18: anti-glare layer 20, 32, 36: polarizing plate 22: polarizing layer 30: liquid crystal display device 34: liquid crystal panel

 ──────────────────────────────────────────────────続 き Continuing on the front page F-term (reference) 2H042 BA03 BA13 BA15 BA20 4F100 AA20H AH05B AK01A AK01B AK01C AK25 AL06B AR00A BA02 BA05 BA07 BA10A BA10B BA11C CA23 DD01B EH462 EJ082 EJ522 GB41 JBAJBA01 JB04BJBBJBA01 KK07 LL04 LL08

Claims (8)

[Claims] 1. An antiglare film comprising at least one resin layer laminated on a transparent substrate film, and an uppermost layer having an antiglare layer having irregularities, wherein the surface of the antiglare layer is antifouling. An antiglare film having properties. 2. The antiglare film according to claim 1, wherein the antifouling property is represented by a contact angle with triacetin as> 43 deg. 3. The anti-glare film according to claim 1, wherein the anti-glare layer contains a fluorine-modified compound. 4. The antiglare film according to claim 1, wherein the fluorine-modified compound is a fluorine-modified monomer or a fluorine-modified oligomer. 5. The anti-glare film according to claim 1, wherein the resin forming the anti-glare layer is a radiation-curable resin. 6. A polarizing film comprising the anti-glare film according to claim 1. 7. The polarizing film according to claim 6, wherein the antiglare film is subjected to a saponification treatment. 8. A transmissive display device using the antiglare film according to claim 1. Description: