JP2012247779A - Antiglare film, and polarizer plate and display device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antiglare film excellent in blackness by calculating the blackness in consideration of diffusion reflectance and haze, and a polarizer plate and a display device including the antiglare film.SOLUTION: There is provided an antiglare film containing an antiglare layer formed by applying and curing an antiglare coating composition on a transparent substrate, and having the diffusion reflectance (SCE) and the haze which satisfy a mathematical formula 1 as shown below. There are also provided a polarizer plate and a display device including the antiglare film.

Description

  The present invention relates to an antiglare film, a polarizing plate using the same, and a display device.

  The antiglare film has a function of reducing reflection of external light by using irregular reflection by the surface protrusion, and various display panels such as a liquid crystal display (LCD), a plasma display (PDP), and a cathode ray tube (CRT). It is disposed on the surface of an electroluminescent display (EL) or the like, and is used for the purpose of preventing a decrease in contrast due to reflection of external light or preventing a decrease in visibility of the display due to image reflection.

  However, the conventional anti-glare film has excellent anti-glare property because the irregular reflection of external light is severe when the surface unevenness is severe, but the blackness (blackness) is lowered and the contrast ratio of the displayed image is lowered. There are disadvantages. On the contrary, when the surface roughness of the conventional anti-glare film is weak, the anti-glare property, which is a specific purpose of the anti-glare film, decreases because the external light cannot be sufficiently diffusely reflected. There is a disadvantage that the performance is greatly reduced.

  Recently, the trend is changing in the direction of obtaining high blackness and obtaining excellent blackness even if some anti-glare properties are sacrificed. As a result, the evaluation of blackness is attracting attention as an important factor. However, in the conventional case, since the antiglare degree and the blackness are visually evaluated, the objectivity of evaluation is not high. For this reason, a method for measuring the surface roughness and evaluating the anti-glare degree and the blackness has been presented. However, since the surface roughness is an arithmetic average value that does not reflect the standard deviation of the roughness, the appearance changes greatly. However, there is a problem that a lot of parts that are different from a visual part occur, such as the average value of roughness does not change.

  The present invention is for solving the above-described conventional problems, and an object thereof is to provide an antiglare film excellent in blackness by incorporating an objective evaluation method of blackness.

  Another object of the present invention is to provide a polarizing plate and a display device excellent in blackness.

  In order to achieve the above object, the present invention includes an antiglare layer formed by coating and curing an antiglare coating composition on a transparent substrate, and the antiglare layer has a diffuse reflectance (SCE). And a haze satisfy the following mathematical formula 1.

  The value of the mathematical formula 1 is more preferably 1 to 5.0.

  The diffuse reflectance is measured with an ISO standard d / 8 structure, the light source is a pulsed Zenon lamp (D65), and a 6-inch integrating sphere is used to measure the reflectance from 360 nm to 740 nm at intervals of 10 nm. The reflectance is converted into a Y value calculated by CIE1931.

  The antiglare coating composition comprises a translucent resin (A), translucent particles (B), a photoinitiator (C), and a solvent (D), and the translucent particles have an average of The particle size is preferably 1 to 10 μm.

  It is preferable that 0.5-20 weight part of the said translucent particle | grain is contained with respect to 100 weight part of the whole anti-glare antireflection coating composition.

  The present invention for achieving the above object provides a polarizing plate including the antiglare film according to the present invention.

  The present invention for achieving the above object provides a display device comprising the antiglare film according to the present invention.

  According to the present invention, an antiglare film having excellent blackness can be obtained by calculating the blackness in consideration of diffuse reflectance and haze. Therefore, the antiglare film can be usefully applied to polarizing plates and display devices.

The present invention will be described in detail below.
The antiglare film according to the present invention comprises an antiglare layer formed by coating and curing an antiglare coating composition on a transparent substrate, and the antiglare layer comprises diffuse reflectance (SCE) and haze. Satisfies the following mathematical formula 1. An antiglare film that satisfies the following mathematical formula 1 exhibits excellent blackness characteristics.

  First, the antiglare coating composition according to the present invention will be described as follows. The antiglare coating composition according to the present invention comprises a translucent resin (A), translucent particles (B), a photoinitiator (C), and a solvent (D).

Translucent resin (A)
If the said translucent resin is generally used in the said field | area, it will be used without a restriction | limiting.

  The translucent resin can preferably contain a photocurable (meth) acrylate oligomer and / or a photocurable monomer.

  As the (meth) acrylate oligomer, for example, epoxy (meth) acrylate, urethane (meth) acrylate, and the like can be used, and urethane (meth) acrylate is more preferably used.

  The urethane (meth) acrylate can be produced by reacting a polyfunctional (meth) acrylate having a hydroxy group in the molecule and a compound having an isocyanate group in the presence of a catalyst.

  Specific examples of the (meth) acrylate having a hydroxy group in the molecule include 2-hydroxyethyl (meth) acrylate, 2-hydroxyisopropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and caprolactone ring-opening hydroxyacrylate. , At least one selected from the group consisting of a pentaerythritol tri / tetra (meth) acrylate mixture and a dipentaerythritol penta / hexa (meth) acrylate mixture.

  Further, the compound having an isocyanate group specifically includes 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,8-diisocyanatooctane, 1,12-diisocyanatododecane, 1,5-diisocyanato-2-methylpentane, trimethyl-1,6-diisocyanatohexane, 1,3-bis (isocyanatomethyl) cyclohexane, trans-1,4-cyclohexene diisocyanate, 4,4′-methylenebis ( Cyclohexyl isocyanate), isophorone diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, xylene-1,4-diisocyanate, tetramethylxylene-1,3-diisocyanate, 1-chloromethyl-2,4- Diisocyanate, 4,4'-methylenebis (2,6-dimethyl) Le phenyl isocyanate), 4,4'-oxybis (phenyl isocyanate) can be trifunctional isocyanate derived from hexamethylene diisocyanate, and from the group consisting of toluene diisocyanate tri methane-propanol adduct of at least one.

  The photocurable monomer specifically has an unsaturated group such as a (meth) acryloyl group, a vinyl group, a styryl group, or an allyl group as a photocurable functional group in the molecule, Among these, a (meth) acryloyl group is more preferable.

  Examples of the monomer having the (meth) acryloyl group include neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate, propylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and dipropylene. Glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, 1,2,4-cyclohexanetetra ( (Meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaery Ritolol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol tri (meth) acrylate, tripentaerythritol hexatri (meth) Acrylate, bis (2-hydroxyethyl) isocyanurate di (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, isooctyl (meth) acrylate, isodexyl (meth) acrylate, Stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, isobol You can select at least one from the group consisting ol (meth) acrylate.

  The photocurable (meth) acrylate oligomers and / or photocurable monomers exemplified above can be used alone or in combination of two or more.

  Although the said translucent resin is not restrict | limited in particular, It is good to contain 1-80 weight part with respect to 100 weight part of the said anti-glare coating composition whole. When the content of the translucent resin is less than 1 part by weight based on the above criteria, it is difficult to improve the hardness sufficiently, and when it exceeds 80 parts by weight, curling becomes severe.

Translucent particles (B)
The translucent particles are not particularly limited as long as they are generally used for imparting antiglare properties, and any of them can be used.

  Examples of the translucent particles include silica particles, silicone resin particles, melamine resin particles, acrylic resin particles, styrene resin particles, acrylic-styrene resin particles, polycarbonate resin particles, polyethylene resin particles, and chloride. Vinyl resin particles and the like can be used. The above-mentioned translucent particles can be used alone or in admixture of two or more.

  The average particle diameter of the translucent particles is preferably 1 to 10 μm. When the average particle diameter of the translucent particles is less than 1 μm, it is difficult to form irregularities on the surface of the antiglare layer, and thus the antiglare property is low. When it exceeds 10 μm, the surface of the antiglare layer is rough. Therefore, there is a disadvantage that visibility is lowered.

  Moreover, it is preferable that 0.5-20 weight part of said translucent particles are contained with respect to 100 weight part of the said anti-glare coating composition whole. When the translucent particles are less than 0.5 parts by weight based on the above criteria, the antiglare property is deteriorated, and when they are more than 20 parts by weight, the antiglare layer is severely whitened.

Photoinitiator (C)
If the said photoinitiator is used in the said field | area, it can be used without a restriction | limiting. Preferably, the photoinitiator may be at least one selected from the group consisting of hydroxyketones, aminoketones, and hydrogen deprivation photoinitiators.

  Specific examples of the photoinitiator include 2-methyl-1- [4- (methylthio) phenyl] 2-morpholinepropan-1-one, diphenylketone benzyldimethylketal, 2-hydroxy-2-methyl-1 -Phenyl-1-one, 4-hydroxycyclophenyl ketone, dimethoxy-2-phenylatetophenone, anthraquinone, fluorene, triphenylamine, carbazole, 3-methylacetophenone, 4-chloroacetophenone, 4,4-dimethoxyacetophenone, 4 1, 4-diaminobenzophenone, 1-hydroxycyclohexyl phenyl ketone, and at least one selected from the group consisting of benzophenone can be used.

  The said photoinitiator can use 0.1-10 weight part with respect to 100 weight part of the whole anti-glare coating composition. When the content of the photoinitiator is less than 0.1 parts by weight based on the above criteria, the curing rate is slow, and when it exceeds 10 parts by weight, the antiglare layer may crack due to overcuring.

Solvent (D)
If the said solvent is generally used in the said field | area, it can be used without a restriction | limiting.

  For example, the above solvents include alcohols (methanol, ethanol, isopropanol, butanol, methyl cellosolve, ethyl cellosolve, etc.), ketones (methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, cyclohexanone, etc.), hexane A system (hexane, heptane, octane, etc.), a benzene system (benzene, toluene, xylene, etc.) and the like are preferably used. The above-mentioned solvents can be used alone or in combination of two or more.

  The content of the solvent may be 10 to 95 parts by weight with respect to 100 parts by weight of the entire antiglare coating composition. When the solvent is less than 10 parts by weight based on the above criteria, the viscosity is increased and workability is lowered. When the solvent is more than 95 parts by weight, the curing process takes a long time and the economy is lowered.

  The antiglare coating composition described above contains at least one selected from the group consisting of an antioxidant, a UV absorber, a light stabilizer, a leveling agent, a surfactant, and an antifouling agent in addition to the above components. Further can be included.

  The antiglare film according to the present invention comprises an antiglare layer formed by coating and curing the antiglare coating composition on at least one surface of a transparent substrate.

  Any film can be used as the transparent substrate as long as it is a transparent film. For example, the transparent substrate includes cellulose (diacetylcellulose, triacetylcellulose, acetylcellulose butylene, etc.) having cycloolefin-containing monomer units such as norbornene and polycyclic norbornene-based monomers. Rate, isobutyl ester cellulose, propionyl cellulose, butyryl cellulose, acetylpropionyl cellulose), ethylene-vinyl acetate copolymer, polyester, polystyrene, polyamide, polyetherimide, polyacryl, polyimide, polyethersulfone, polysulfone, polyethylene, polypropylene , Polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether keto , Polyethersulfone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyurethane, and epoxy can be used, and unstretched, uniaxially or biaxially stretched film can be used. Can be used. Preferably, a uniaxially or biaxially stretched polyester film excellent in transparency and heat resistance, or a triacetyl cellulose film having no transparency and optical anisotropy can be used.

  The above-mentioned transparent substrate is preferably thin, but if it is too thin, the strength will decrease and the processability will be poor, and if it is too thick, the transparency will decrease or the weight of the polarizing plate will increase. A problem occurs. Therefore, the transparent substrate preferably has a thickness of about 8 to 1,000 μm, more preferably 40 to 100 μm.

  The application of the antiglare coating composition is not limited, and can be appropriately performed by a method selected from, for example, a die coater, an air knife, a reverse roll, a spray, a blade, casting, a gravure, a microgravure, or a spin coating.

  The thickness of the antiglare layer formed by applying the antiglare coating composition is 1 to 30 μm, preferably about 1 to 20 μm, more preferably 3 to 15 μm.

After applying the antiglare coating composition, it is dried at a temperature of 30 to 150 ° C. for 10 seconds to 1 hour, preferably 30 seconds to 10 minutes. When drying is completed, the antiglare coating composition is cured. In the case of photocuring, the antiglare coating composition is cured by irradiating UV light to form an antiglare layer. The irradiation amount of the UV light is about 0.01 to 10 J / cm ² , preferably 0.1 to ² J / cm ² .

  In this case, in the antiglare film of the present invention, the diffuse reflectance (SCE) and the haze satisfy the mathematical formula 1. That is, the diffuse reflectance and haze of the antiglare film are measured, the diffuse reflectance is multiplied by haze, and the numerical range is preferably 0.1 to 5.0, and preferably 1 to 5.0. Further preferred. An antiglare film satisfying such a range exhibits satisfactory blackness.

  When haze is applied to the diffuse reflectance and the numerical range is less than 0.1, there is a problem that the glare of external light cannot be prevented because the antiglare property is weak, and exceeds 5.0. In this case, there is a problem that the scattering is severe and the blackness is lowered.

  The above diffuse reflectance is measured with an ISO standard d / 8 structure (use of diffuse illumination, 8 degree light receiving method), and the light source is reflected from 360 nm to 740 nm at intervals of 10 nm using a pulsed Zenon lamp (D65) and a 6 inch integrating sphere. The reflectance is measured, and the reflectance measured with the above wavelength is converted into a Y value calculated by CIE 1931 and used. Such diffuse reflectance can be easily measured by using a diffuse reflectance measuring instrument used in this field.

  In addition, the said haze can be measured with the haze measuring device normally used in the said field | area.

  The polarizing plate according to the present invention is provided with the above-described antiglare film according to the present invention.

  That is, the polarizing plate of the present invention can be formed by laminating the above-described antiglare film of the present invention on one surface or both surfaces of a normal polarizer. The polarizer may be provided with a protective film on at least one surface.

  The polarizer is uniaxial by adsorbing a dichroic substance such as iodine or a dichroic dye on a hydrophilic polymer film such as a polyvinyl alcohol film or an ethylene-vinyl acetate copolymer partially saponified film. A polyene-based oriented film such as a stretched film, a dehydrated polyvinyl alcohol product or a dehydrochlorinated polyvinyl chloride product can be used. Preferably, it can consist of a dichroic substance such as a polyvinyl alcohol film and iodine. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.

  When the polarizer is provided with a protective film on at least one surface, the protective film preferably has excellent transparency, mechanical strength, thermal safety, water shielding property, isotropic property, and the like. Can.

  For example, as the protective film, polyester films such as polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate; cellulose films such as diacetyl cellulose and triacetyl cellulose; polycarbonate films; polymethyl (meth) acrylate, polyethyl (meth) Acrylic films such as acrylates; Styrene films such as polystyrene and acrylonitrile-styrene copolymers; Polyolefin films such as polyethylene, polypropylene, cyclo- or norbornene structures, and ethylene-propylene copolymers; Polyimide-based films Polyethersulfone film; sulfone film and the like can be used. Of the protective films listed above, a triacetyl cellulose film can be preferably used in terms of excellent transparency and no optical anisotropy. The thickness in particular of the said protective film is not restrict | limited, It is preferable that it is 8-1000 micrometers, and it is more preferable that it is 40-100 micrometers.

The display device according to the present invention includes the antiglare film according to the present invention.
As an example, the display device may include a polarizing plate provided with an antiglare film as described above.

  When a polarizing plate provided with the antiglare film of the present invention is included in a display device, a display device having excellent visibility can be provided. The antiglare film of the present invention can also be used by being attached to a window of a display device.

  The antiglare film of the present invention is used in reflective, transmissive, transflective LCDs or LCDs of various drive systems such as TN, STN, OCB, HAN, VA, and IPS. The antiglare hard coating film of the present invention is also used in various display devices such as a plasma display, a field emission display, an organic EL display, an inorganic EL display, or electronic paper.

  The above display device can be easily formed by adopting a configuration known in the art, in addition to the application of the antiglare film according to the present invention, and a detailed description thereof will be omitted.

  The display device according to the present invention described above can exhibit excellent light diffusibility, transmission clarity, and good front luminance.

  The present invention is further embodied by the following examples and production examples, and the following production examples and examples are only specific illustrations of the present invention, and limit or limit the protection scope of the present invention. It is not a thing.

(Production Example 1) Production of antiglare coating composition 25 parts by weight urethane acrylate (manufactured by Miwon Shoji Co., SC2153), 18.5 parts by weight pentaerythritol triacrylate (manufactured by Miwon Shoji Co., Ltd., M340), 2 parts by weight translucent Particles (acrylic resin particles, average particle size 4.5 μm), 50 parts by weight methyl ethyl ketone (manufactured by Oi Chemical Co., Ltd.), 4 parts by weight photoinitiator (manufactured by BASF (formerly CIBA), I-184), A 0.5 part by weight leveling agent (BYK Chemi, BYK378) was blended using a stirrer and filtered using a PP material filter to produce a composition having a refractive index of 1.49.

(Production Example 2) Production of antiglare coating composition 25 parts by weight urethane acrylate (manufactured by Miwon Shoji Co., SC2153), 18.5 parts by weight pentaerythritol triacrylate (manufactured by Miwon Shoji Co., Ltd., M340), 2 parts by weight translucent Particles (acrylic resin particles, average particle size 3 μm), 50 parts by weight methyl ethyl ketone (manufactured by Oi Kakin Co., Ltd.), 4 parts by weight photoinitiator (manufactured by BASF, I-184), 0.5 part by weight leveling agent ( BYK Chemi Corporation, BYK378) was blended using a stirrer and filtered using a PP material filter to produce a composition having a refractive index of 1.49.

(Production Example 3) Production of anti-glare coating composition 25 parts by weight urethane acrylate (manufactured by Miwon Shoji Co., SC2153), 18.5 parts by weight pentaerythritol triacrylate (manufactured by Miwon Shoji Co., Ltd., M340), 2 parts by weight translucent Particles (acrylic resin particles, average particle size 2 μm), 50 parts by weight methyl ethyl ketone (manufactured by Oi Chemical Co., Ltd.), 4 parts by weight photoinitiator (manufactured by BASF, I-184), 0.5 part by weight leveling agent ( BYK Chemi Corporation, BYK378) was blended using a stirrer and filtered using a PP material filter to produce a composition having a refractive index of 1.49.

(Production Example 4) Manufacture of antiglare coating composition 26 parts by weight urethane acrylate (manufactured by Miwon Shoji Co., SC2153), 18.5 parts by weight pentaerythritol triacrylate (manufactured by Miwon Shoji Co., Ltd., M340), 1 part by weight translucent Particles (acrylic resin particles, average particle size 4.5 μm), 50 parts by weight methyl ethyl ketone (manufactured by Oi Kakin Co., Ltd.), 4 parts by weight photoinitiator (BASF, I-184), 0.5 part by weight leveling An agent (BYK Chemi, BYK378) was blended using a stirrer and filtered using a PP material filter to produce a composition having a refractive index of 1.49.

(Production Example 5) Production of antiglare coating composition 25 parts by weight urethane acrylate (manufactured by Miwon Shoji Co., SC2153), 18.5 parts by weight pentaerythritol triacrylate (manufactured by Miwon Shoji Co., Ltd., M340), 2 parts by weight translucent Particles (styrene resin particles, average particle size 4.5 μm), 50 parts by weight methyl ethyl ketone (manufactured by Oi Kakin Co., Ltd.), 4 parts by weight photoinitiator (manufactured by BASF, I-184), 0.5 part by weight leveling An agent (BYK Chemi, BYK378) was blended using a stirrer and filtered using a PP material filter to produce a composition having a refractive index of 1.49.

(Examples 1-8 and Comparative Examples 1-2)
An anti-glare film is applied to one side of an 80 μm thick triacetyl cellulose film by applying the anti-glare coating composition produced in the above production example as shown in Table 1 below, and then UV-curing after heating and drying. Manufactured.

<Experimental example>
The physical properties of the antiglare antireflection film produced as described above were measured and the results are shown in Table 1 below.

1) Diffuse reflectance (SCE) (%)
After the manufactured anti-glare film is bonded to the black acrylic plate, the diffuse reflectance (SCE) of the integrating sphere reflectance on the surface of the coating layer is measured using a spectrophotometer (CM-3700d, manufactured by Konica Minolta). Measured.

2) Haze (%)
After joining the manufactured anti-glare film to a glass plate, the haze of the film was measured with a transmittance meter (HZ-1 manufactured by Suga).

3) Blackness After the manufactured antiglare film is bonded to a black acrylic plate so that the coating surface faces the surface, the fluorescent lamp is reflected under a three-wavelength fluorescent lamp, and the part at a distance of 5 cm from the fluorescent lamp reflected image is reflected. The blackness was evaluated by visual comparison.
◎: Near black ○: Near black gray X: Gray

  As shown in Table 1 above, in the example in which the value obtained by multiplying the diffuse reflectance (SCE) by haze is included in the scope of the present invention, the blackness is higher than that in the comparative example deviating from the scope of the present invention. It can be confirmed that it is very excellent.

Claims (7)

Comprising an antiglare layer formed by coating and curing an antiglare coating composition on a transparent substrate;
The antiglare layer is characterized in that the diffuse reflectance (SCE) and haze satisfy the following mathematical formula 1.

  The antiglare film according to claim 1, wherein the value of the mathematical formula 1 is 1 to 5.0.   The diffuse reflectance is measured with an ISO standard d / 8 structure, the light source is a pulsed Zenon lamp (D65), and a 6-inch integrating sphere is used to measure the reflectance from 360 nm to 740 nm at intervals of 10 nm, and is measured according to the wavelength. The antiglare film according to claim 1, wherein the reflectance is converted into a Y value calculated by CIE1931.   The antiglare coating composition comprises a translucent resin (A), translucent particles (B), a photoinitiator (C), and a solvent (D), and the translucent particles have an average The antiglare film according to any one of claims 1 to 3, wherein the particle size is 1 to 10 µm.   The antiglare film according to claim 4, wherein the translucent particles are contained in an amount of 0.5 to 20 parts by weight with respect to 100 parts by weight of the entire antiglare antireflection coating composition.   A polarizing plate comprising the antiglare film of any one of claims 1 to 5.   A display device comprising the antiglare film according to claim 1.