JP2009244898A - Antiglare film having antifouling property - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antiglare film excellent in antifouling property without degradation of various performances as the antiglare film, and to provide a polarization plate and a transmission display device using the antiglare film. <P>SOLUTION: The antiglare film includes a transparent substrate film and at least one or more resin layers laminated thereon, the top layer of which is an antiglare layer having irregularities, a surface of the antiglare layer having antifouling property. The polarization plate and the transmission display device use this antiglare film. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an antiglare film provided on the surface of a high-definition image display such as a CRT or a liquid crystal panel used for image display of a computer, a word processor, a television, etc., a polarizing film using the antiglare film, and a transmissive display device. .

  In the display as described above, an anti-glare film for diffusing the light emitted from the inside to some extent is mainly dazzling when viewing the display surface when the light emitted from the inside goes straight without diffusing on the display surface. It is provided on the display surface.

  This anti-glare film is formed, for example, by applying a resin containing a filler such as silicon dioxide (silica) to the surface of a transparent base film as disclosed in Patent Document 1, Patent Document 2, and the like. It is.

  These antiglare films are a type in which an irregular shape is 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 film thickness of the coating film is added to the resin. There is a type in which a concavo-convex shape is formed on the surface, or a type in which a concavo-convex shape is transferred by laminating a film having ruggedness on the surface of the layer.

JP-A-6-18706 Japanese Patent Laid-Open No. 10-20103

  The conventional anti-glare film as described above has silicone oil added as a leveling agent at the time of forming the surface layer, and has a certain degree of anti-fouling property. For example, fingerprint adhesion during handling, other lipophilic substances There is a problem that the antifouling property is insufficient and the quality of the display image is deteriorated when the surface is dirty.

  Further, the antiglare film for the polarizing film has a triacetate cellulose film as a transparent base film, and after forming a necessary layer on the base film, it is saponified with an alkaline aqueous solution, and has a polarizing polyvinyl alcohol film. Although it is manufactured by pasting with an adhesive, the silicone oil that is usually used as a leveling agent and present on the outermost surface is decomposed and removed by the alkali treatment, and this antiglare film is completely antifouling. For example, there is a problem that the quality of the displayed image is further deteriorated due to loss of the property, easily contaminated by fingerprints, plasticizers, other oils, and the like.

  Accordingly, an object of the present invention is to solve the above-mentioned conventional problems, and without reducing various performances as an antiglare film, an antiglare film excellent in antifouling properties, a polarizing plate and a transmission type using the antiglare film It is to provide a display device.

  The above object is solved by the present invention described below. That is, the present invention is an antiglare film in which at least one resin layer is laminated on a transparent substrate film and the uppermost layer is an antiglare layer having irregularities, and the surface of the antiglare layer is an antiglare layer. An antiglare film characterized by having a soiling property, a polarizing plate using the antiglare film, and a transmissive display device are provided.

  In the present invention, in order for the antiglare film to have a significant antifouling property, it has been found that the contact angle of the surface with respect to triacetin is preferably> 43 deg. It has also been found that the antifouling property can be achieved by including a fluorine-modified compound in the antiglare layer. In addition, when the base film is a triacetate film, it has been found that the contact angle with respect to triacetin on the surface of the antiglare layer can be maintained at> 43 deg even after the antiglare film is alkali-treated. It was.

Sectional drawing which shows the anti-glare film which concerns on the example of embodiment of this invention. Sectional drawing which shows the manufacturing process of the anti-glare film. Sectional drawing which shows the polarizing plate using the anti-glare film of this invention. Sectional drawing which shows the transmissive display apparatus using the anti-glare film of this invention.

Next, exemplary 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 example of the present invention is formed by laminating at least one resin layer on a transparent base film 12, and an antiglare layer 18 having irregularities as an uppermost layer. The antiglare film is characterized in that the surface of the antiglare layer has antifouling properties.

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

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

  In this invention, it obtains by laminating | stacking at least 1 layer or more of resin layers on the said transparent base film 12, and forming the glare-proof layer 18 which has an unevenness | corrugation in the uppermost layer and has antifouling property. The antiglare layer 18 can be formed from the light transmissive resin 14 containing the light transmissive fine particles 16 and the fluorine-modified compound. As the translucent resin 14, there are three types of resins which are mainly cured by ultraviolet rays and electron beams, that is, ionizing radiation curable resins, ionizing radiation curable resins mixed with a thermoplastic resin and a solvent, and thermosetting resins. Is used.

  The film forming component of the ionizing radiation curable resin composition is preferably one having an acrylate-based functional group, such as a relatively low molecular weight polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin, alkyd resin. , Spiroacetal resins, polybutadiene resins, polythiol polyene resins, oligomers or prepolymers of polyfunctional compounds such as polyhydric alcohols such as (meth) acrylates, and reactive diluents such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene , Methyl styrene, N-vinyl pyrrolidone and other monofunctional monomers as well as polyfunctional monomers such as polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate Compare diate glycol, 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. A large amount can be used.

  Furthermore, in order to make the ionizing radiation curable resin composition into an ultraviolet curable resin composition, acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethyl Lam monosulfide, thioxanthones, and n-butylamine, triethylylamine, poly-n-butylphosphine and the like can be mixed and used as a photosensitizer. In particular, in the present invention, it is preferable to mix urethane acrylate as an oligomer and dipentaerythritol hexa (meth) acrylate as a monomer.

  Furthermore, as the translucent resin 14 for forming the antiglare layer 18, a solvent-drying resin may be included in the ionizing radiation curable resin as described above. As the solvent-drying resin, a thermoplastic resin is mainly used. As the type of solvent-drying thermoplastic resin to be added to the ionizing radiation curable resin, those usually used are used, but when using the cellulose-based resin such as TAC as described above as the transparent substrate film 12, ionizing radiation is used. Cellulose resins such as nitrocellulose, acetyl cellulose, cellulose acetate propionate, and ethyl hydroxyethyl cellulose are advantageous as solvent-drying resins to be included in the curable resin in terms of adhesion and transparency of the coating film.

  The reason for this is that when toluene is used as the solvent for the above cellulose-based resin, the transparent substrate film 12 is made of toluene, which is a non-soluble solvent for polyacetylcellulose, which is the transparent substrate film 12. Even when a coating containing this solvent-drying resin is applied, the adhesion between the transparent substrate film 12 and the coating film resin can be improved, and this toluene is a polyacetylcellulose which is a transparent substrate film. This is because the surface of the transparent base film 12 is not whitened, and the transparency is maintained.

  The translucent fine particles 16 to be contained in the antiglare layer 18 are preferably plastic beads, particularly those having high transparency and values that require a difference in refractive index from the matrix resin (translucent resin 14). preferable. Plastic beads include melamine beads (refractive index 1.57), acrylic beads (refractive index 1.49), acrylic-styrene beads (refractive index 1.54), polycarbonate beads, polyethylene beads, polystyrene beads, polyvinyl chloride beads, etc. Used. As described above, those plastic beads having a particle diameter of 0.5 to 5 μm are appropriately selected and used.

  When the above-mentioned translucent fine particles 16 as the organic filler are added, the organic filler is likely to settle in the resin composition (translucent resin 14), so that an inorganic filler such as silica is used to prevent sedimentation. May be added. The more inorganic filler is added, the more effective the prevention of sedimentation of the organic filler is, but it has an adverse effect on the transparency of the coating film. Therefore, it is preferable to prevent sedimentation when an inorganic filler having a particle size of 0.5 μm or less is contained in an amount of less than 0.1% by weight so as not to impair the transparency of the coating film with respect to the translucent resin 16. Can do. When an inorganic filler that is an anti-settling agent for preventing settling of the organic filler is not added, the organic filler is precipitated at the bottom when applied to the transparent substrate film 12, so that it is thoroughly stirred and used. That's fine.

  In the present invention, the antiglare layer is formed on the transparent substrate film by using the antiglare layer forming composition obtained by adding a fluorine-modified compound to the above antiglare layer forming composition. An antiglare film is obtained. Examples of the fluorine-modified compound include monomers, oligomers and polymers of perfluoroalkyl sulfonates and perfluoroalkyl carboxylates, and among these, fluorine-modified monomers or 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 even by subjecting the obtained antiglare film to an alkali treatment later. Dirtyness is maintained.
The fluorine-modified compound is preferably used in an amount of about 0.5 to 1.0 parts by weight per 100 parts by weight of the solid content of the composition for forming an antiglare layer. If the amount used is less than the above range, satisfactory antifouling properties cannot be obtained, and the contact angle of the antiglare layer or the antiglare layer after alkali treatment with respect to triacetin cannot be> 43 deg. On the other hand, even if the amount used exceeds the above range, the contact angle cannot be further improved, and the hardness of the antiglare layer is unfavorable.

  As a curing method of the ionizing radiation curable resin composition containing the fluorine-modified compound as described above, the curing method of the ionizing radiation curable resin composition is a normal curing method, that is, is cured by irradiation with electron beams or ultraviolet rays. be able to. For example, in the case of electron beam curing, 50 emitted from various electron beam accelerators such as a Cockloft Walton type, a handigraph type, a resonant transformation type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type. An ultraviolet ray emitted from rays such as an ultra-high pressure mercury lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, a carbon arc, a xenon arc, or a metal halide lamp is used when an electron beam having an energy of ˜1000 KeV, preferably 100-300 KeV is used. Etc. are available.

Here, in general, the refractive index of the ionizing radiation curable resin is about 1.5, which is about the same as that of glass, but when the refractive index of the resin used is low in comparison with the refractive index of the translucent particles. , TiO ₂ (refractive index; 2.3 to 2.7), Y ₂ O ₃ (refractive index; 1.87), La ₂ O ₃ (refractive index), which are fine particles having a high refractive index. 1.95), ZrO ₂ (refractive index; 2.05), A1 ₂ O ₃ (refractive index; 1.63), etc. are added to such an extent that the diffusibility of the coating film can be maintained, and the refractive index is increased. Can be adjusted.

  Next, a process of forming the antiglare layer 18 on the surface of the transparent substrate film 12 will be described with reference to FIG. As shown in FIG. 2 (B), a transparent resin 14 containing a fluorine-modified compound and a transparent fine particle 16 is applied to the transparent substrate film 12 shown in FIG. Then, the shaping film 19 having fine irregularities formed on the surface is laminated so that the surface is in contact with the coating layer (see FIG. 2C), and then the light-transmitting resin 14 is an electron beam or In the case of an ultraviolet curable resin, these anti-glare layers are obtained by irradiating these electron beams or ultraviolet rays through the shaping film 19, and in the case of a solvent-drying resin, after heating and curing, the shaping film 19 is cured. Peel from 18.

  If it does in this way, the glare-proof layer 18 will be in a smooth state as a whole, and the fine unevenness | corrugation previously formed in the shaping film 19 will be shape | molded. Therefore, the surface of the diffusion layer 18 can be made smoother as compared with 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, the example of embodiment of the polarizing plate concerning this invention shown by FIG. 3 is demonstrated. As shown in FIG. 3, the polarizing plate 20 of the example of this embodiment is provided with the same antiglare film 11 on one surface (upper surface side in FIG. 3) of the polarizing layer (polarizing element) 22. It is a configuration. The polarizing layer 22 is laminated between TAC films 12A and 24, which are two transparent substrate films, and has a three-layer structure. The first layer and the third layer are made of polyvinyl alcohol (PVA) with iodine. In addition, the intermediate second layer is made of a PVA film. The antiglare film 11 has a structure in which an antiglare layer 18 is laminated on a TAC film 12A.

  The TAC provided on both outer sides of the polarizing layer 22 and serving as a transparent substrate film does not have birefringence and the polarization is not disturbed. Therefore, even when laminated with the PVA and PVA + iodine films serving as the polarizing elements, the polarization is not disturbed. Therefore, a liquid crystal display device with excellent display quality can be obtained using such a polarizing plate 20. As a polarizing element constituting the polarizing layer 22 in the polarizing plate 20 as described above, a polyvinyl formal film, a polyvinyl acetal film, an ethylene-vinyl acetate copolymer system, a PVA film dyed with iodine or a dye and stretched. Film. In addition, when laminating the film constituting the polarizing layer 22, the TAC films 12 and 24 may be saponified with an alkaline aqueous solution in order to increase adhesion and prevent static electricity. This alkali treatment is preferably performed, for example, using an aqueous alkali solution such as 2N potassium hydroxide or sodium hydroxide at a temperature of about 40 to 80 ° C. for about 60 to 120 seconds. By such saponification, the surface of the TAC film becomes hydrophilic and the adhesion to the PVA film is improved.

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

  Liquid crystal modes used in the liquid crystal panel 34 in the liquid crystal display device 30 include twisted nematic type (TN), super twisted nematic type (STN), guest-host type (GH), phase transition type (PC), and polymer. Any of dispersion type (PDLC) or the like may be used. The liquid crystal drive mode 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, MIM, etc. is adopted. Further, the liquid crystal panel 34 may be either a color type or a monochrome type.

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 size 1 μm) 7 parts by weight Fluorine-modified acrylic oligomer (DEFENSA MCF-323 made 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 onto 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 haze of the antiglare film thus obtained was 13, and the contact angle measurement using triacetin was 60 °. This film was immersed in a 2N aqueous solution of caustic potassium for 90 seconds at 60 ° and saponified, and the contact angle measurement using triacetin was 53 °. This antiglare film was excellent in antifouling property, and no fingerprint was attached even when the finger was pressed against the surface.

Example 2
Pentaerythritol triacrylate (PETA) 100 parts by weight Silica filler (secondary particle size 1 μm) 7 parts by weight Fluorine-modified acrylic oligomer (DEFENSA MCF-323, manufactured by Dainippon Ink and Chemicals)
0.2 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 onto 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 haze of the antiglare film thus obtained was 13, and the contact angle measurement using triacetin was 68 °. The film was immersed in a 2N aqueous solution of caustic potassium for 90 seconds at 60 ° and saponified, and the contact angle measurement using triacetin was 50 °. This antiglare film was excellent in antifouling property, 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 size 1 μm) 7 parts by weight Fluorine-modified silicone (XC98-A5382 made by Toshiba Silicone) 5 parts by weight Toluene 130 parts by weight The above materials are mixed to form an antiglare layer The paint was used. This paint was applied onto 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 haze of the antiglare film thus obtained was 13, and the contact angle measurement using triacetin was 7 °. The contact angle measurement using triacetin after the film was immersed in a 2N aqueous solution of caustic potassium for 90 seconds at 60 ° and saponified 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 size 1 μm) 7 parts by weight Fluorine modified silicone (XC98-A5382 made by Toshiba Silicone) 0.2 parts by weight Toluene 130 parts by weight Antiglare by mixing the above materials A layer-forming paint was obtained. This paint was applied onto 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 using triacetin of 35 °. The contact angle measurement using triacetin after the film was immersed in a 2N aqueous solution of caustic potassium for 90 seconds at 60 ° and saponified 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 an antiglare layer-forming coating material. This paint was applied onto 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 haze of the antiglare film thus obtained was 13, and the contact angle measurement using triacetin was 43 °. The film was immersed in a 2N aqueous solution of caustic potassium for 90 seconds at 60 ° and saponified, and the contact angle measurement 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.

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

10, 11: Anti-glare film 12: Transparent substrate film 14: Translucent resin 16: Translucent fine particles 18: Anti-glare layers 20, 32, 36: Polarizing plate 22: Polarizing layer 30: Liquid crystal display device 34: Liquid crystal panel

Claims (6)

  An antiglare film for a display in which at least one resin layer is laminated on a transparent substrate film, and the uppermost layer is an antiglare layer having irregularities, the antiglare layer comprising an ionizing radiation curable resin and A display comprising: a composition for forming an antiglare layer containing a fluorine-modified monomer or fluorine-modified oligomer that is polymerized and cured together with the resin, cured by ultraviolet or electron beam irradiation, and the surface thereof has antifouling properties Antiglare film for use.   The antiglare film for a display according to claim 1, wherein the antifouling property is represented as a contact angle with respect to triacetin of> 43 deg, and a contact angle with respect to triacetin of the antiglare layer after alkali treatment is represented as> 43 deg.   A method for producing an antiglare film for a display in which at least one resin layer is laminated on a transparent substrate film and the uppermost layer is an antiglare layer having irregularities, and the antiglare layer is cured with ionizing radiation. A composition for forming an antiglare layer comprising a mold resin and a fluorine-modified monomer or fluorine-modified oligomer that is polymerized and cured together with the resin is cured by ultraviolet or electron beam irradiation, and the surface thereof is in contact with triacetin A method for producing an antiglare film for a display having an antifouling property in which the angle is represented as> 43 deg and the contact angle of the antiglare layer after alkali treatment with triacetin is represented as> 43 deg.   A polarizing film using the antiglare film for a display according to claim 1 or 2.   The polarizing film according to claim 4, wherein the antiglare film for display is saponified.   A transmissive display device using the display antiglare film according to claim 1.

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