JP2016504621A - Anti-glare film and polarizing plate provided with the same - Google Patents

Abstract

The present invention relates to an antiglare film, and more specifically, an antiglare layer forming composition containing a reactive (meth) acrylate resin, translucent particles and a photoinitiator is applied to one surface of a transparent substrate film. The antiglare layer comprises a formed antiglare layer, and has a height variance value of 0.05 to 0.3 μm2, and a skewness value of 0.5 to 2. It is related with the anti-glare film characterized by being 0.0.

Description

  The present invention relates to an antiglare film and a polarizing plate provided with the same.

  Examples of the image display device include a liquid crystal display device (LCD), an electroluminescence (EL) display device, a plasma display (PDP), and a field emission display (FED).

  When such various image display apparatuses are exposed to external light such as natural light or illumination light, the contrast is lowered while the light incident on the surface of the image display apparatus is reflected, and the visibility is lowered due to the image reflection. In addition, the screen becomes dazzling, character recognition is difficult, eye fatigue tends to increase, or headaches are induced.

  In order to solve such problems, anti-glare films that have the function of inducing irregular reflection of light by the surface protrusion and reducing the reflection of light and are arranged on the surface of various image display devices are mainly used. It was done.

  An antiglare film is formed by applying a resin containing filler particles such as silica or resin beads to the surface of a transparent base film, and the surface of the transparent antiglare film is formed by agglomeration of silica or the like. Some have surface irregularities formed by adding organic filler particles having a particle diameter larger than the thickness of the applied resin film.

  On the other hand, Korean Patent No. 1,067,546 (Patent Document 1) contains at least one surface of a transparent substrate film containing cured resin, silica fine particles, and silicon resin fine particles by ionizing radiation, and fine irregularities are formed on the surface. An antiglare film is disclosed.

  However, the anti-glare film according to the above document has a high haze value of 35% or more. Thus, when the haze value of an anti-glare film rises, there exists a problem that the clarity and visibility of a display fall.

  Japanese Patent Publication No. 2009-104076 (Patent Document 2) relates to an antiglare film in which the antiglare property is controlled in the range of kurtosis and skewness, and the kurtosis of the antiglare layer is 3 or less. There is disclosed an antiglare film having an antiglare layer in which the absolute value of the skewness of the height of the antiglare layer is 1 or less.

  However, the kurtosis and the skewness are merely statistical values indicating the distribution of the surface unevenness, and have no correlation with the height of the surface unevenness. Therefore, even if it is included in the numerical value range of the skewness disclosed in the above document, there is a problem that the surface unevenness is small and the haze is high or the surface unevenness is large and the antiglare property may not appear. There is.

Korean Registered Patent No. 1,067,546 Japanese Unexamined Patent Publication No. 2009-104076

  The present invention uses the height variance of the antiglare layer and the skewness value simultaneously as parameters for indicating the optical characteristics of the antiglare film, and has low haze and excellent transmission clarity. An object of the present invention is to provide an antiglare film.

In order to achieve the object of the present invention, the present invention comprises applying a composition for forming an antiglare layer comprising a reactive (meth) acrylate resin, translucent particles and a photoinitiator to one surface of a transparent substrate film. The anti-glare layer comprises a formed anti-glare layer, and has a height variance value of 0.05 to 0.3 μm ² and a skewness value of 0.5 to 2. Provided is an antiglare film characterized by being zero.

  The composition for forming an antiglare layer is a mixture of a reactive (meth) acrylate resin and translucent particles in a weight ratio of 96.0: 4.0 to 98.5: 1.5. it can.

  The translucent particles comprise large particles and small particles, the average particle size of the large particles is 1.05 to 1.25 times the thickness of the antiglare layer, and the average particle size of the small particles is The average particle size of the large particles may be 0.5 to 0.9 times.

  The large particles and the small particles may be mixed at a weight ratio of 25:75 to 75:25.

  The composition for forming an antiglare layer comprises at least one selected from the group consisting of a solvent, a photoinitiator, an antioxidant, a UV absorber, a light stabilizer, a labeling agent, a surfactant, and an antifouling agent. Further can be included.

  The haze of the antiglare film may be 1 to 10%, and the transmission sharpness may be 200% or more.

  In order to achieve another object of the present invention, the polarizing plate may include the antiglare film.

The anti-glare film according to the present invention has an anti-glare property by having a height variance of 0.05 to 0.3 μm ² and a skewness of 0.5 to 2.0. In addition to being excellent, it has the advantages of high transparency and low haze value.

The antiglare film of the present invention is an antiglare layer formed by applying a composition for forming an antiglare layer containing a reactive (meth) acrylate resin, translucent particles and a photoinitiator to one surface of a transparent substrate film. And the antiglare layer has a height variance value of 0.05 to 0.3 μm ² and a skewness value of 0.5 to 2.0. And

  Hereinafter, the present invention will be described in more detail, but this is for the purpose of explaining the present invention and does not limit the scope of the present invention.

  The antiglare layer is formed by curing the composition for forming an antiglare layer, and is a layer containing “resin for antiglare layer” and “translucent particles”.

  In this case, “resin for antiglare layer” means a film formed by curing a composition containing (meth) acrylate resin, and formed by curing a composition containing (meth) acrylate resin. The translucent particles are distributed inside the antiglare layer resin.

  The composition for forming an antiglare layer contains a reactive (meth) acrylate resin, translucent particles, and a photoinitiator.

  The reactive (meth) acrylate resin forms a cured layer and is used to improve hardness and scratch resistance. The reactive (meth) acrylate resin is not particularly limited, and those known in the art can be used. Preferably, a photocurable acrylic resin can be used. The reactive (meth) acrylate resin may be one or more reactive acrylate oligomers, one or more reactive acrylate monomers, or a mixture of oligomers and monomers. it can.

  The kind of the reactive acrylate oligomer is not particularly limited, and those known in the art can be used, and preferably, the urethane acrylate oligomer can be used. For example, a compound having an isocyanate group in the molecule and a (meth) acrylate compound having a hydroxy group in the molecule can be polymerized. Examples of the compound having an isocyanate group in the molecule include 1,3-bis (isocyanatomethyl) cyclohexane, 4,4′-methylenebis (cyclohexyl isocyanate), 4,4′-methylenebis (2,6-dimethylphenylisocyanate), 4,4′-oxybis (phenylisocyanate), acryloylethylisocyanate, methacryloylethylisocyanate, 4,4′-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate and its trimer, 1,4-diisocyanatobutane, 1,6 -Diisocyanatohexane, 1,8-diisocyanatooctane, 1,12-diisocyanatodecane, 1,5-diisocyanato-2-methylpentane, trimethyl-1,6-diisocyanatohexane, trans-1, 4 Cyclohexene diisocyanate, isophorone diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, xylene-1,4-diisocyanate, tetramethylxylene-1,3-diisocyanate, 1-chloromethyl-2,4-diisocyanate Diisocyanate compounds such as: triisocyanates derived from the diisocyanate compounds; adducts obtained by reacting 3 mol of the diisocyanate compound with 1 mol of a polyhydric alcohol-based compound such as trimethylolpropane; Isocyanurate bodies; burette bodies in which the remaining 1 mole of diisocyanate is condensed to diisocyanate urea obtained from 2 moles of the above 3 moles of diisocyanate compound The recited, it may be used alone or in combination. The kind of (meth) acrylate compound having a hydroxy group in the molecule is not particularly limited. For example, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. may be mentioned, and these may be used alone or in combination of two or more. Can be used. The method for producing the urethane (meth) acrylate oligomer is not particularly limited, and usual arbitrary polymerization reaction, block polymerization reaction, graft polymerization reaction, and the like can be used. For example, it can be produced by a method in which a compound having an isocyanate group in the molecule and a (meth) acrylate compound having a hydroxy group in the molecule are reacted at an appropriate equivalent ratio.

  The kind of reactive (meth) acrylate monomer is not particularly limited, and those known in the art can be used. For example, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, (meth) acrylic ester, trimethylolpropane tri (meth) Acrylate, glycerol tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol (meth) acrylate, 1,3-butanediol di (meth) acrylate 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, bis (2-hydroxyethyl) isocyanurate di (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (Meth) acrylate, hydroxybutyl (meth) acrylate, isooctyl (meth) acrylate, iso-dexyl (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, isoborneol ( At least one selected from the group consisting of (meth) acrylates can be used.

  The translucent particles are those that form irregularities on the surface of the antiglare film to impart antiglare properties to the film, and are not limited to organic particles or inorganic particles as long as they are generally used in the field. Can be used.

  As the organic particles, at least one selected from the group consisting of melamine beads, acrylic beads, acrylic-styrene beads, polycarbonate beads, polyethylene beads, and vinyl chloride beads can be used. As the inorganic particles, at least one selected from the group consisting of calcium bicarbonate (heavy coal), light calcium carbonate, barium sulfate, silica, and alumina can be used.

  The average particle size of the large particles of the antiglare layer forming composition is preferably 1.05 to 1.25 times the thickness of the antiglare layer. In this case, the thickness of the anti-glare layer means the thickness of the “resin of the anti-glare layer” in the anti-glare layer where the irregularities are formed.

  If the average particle size of the large particles is larger than the above value, the height of the unevenness on the coating surface becomes large, which may cause a problem that haze increases. If the average particle size is smaller than the above value, the unevenness on the coating surface disappears. Thus, a problem that the antiglare property is reduced can occur.

  The average particle size of the small particles preferably includes particles that are 0.5 to 0.9 times the diameter of the average particle of the large particles. When the average particle size of the small particles deviates from the above numerical value, there may be a problem that it is difficult to realize sufficient antiglare property in a state where the transmission clarity is high.

  The large particles and the small particles can be mixed at a weight ratio of 25:75 to 75:25. When the content of large particles is lower than the above ratio or is not included, unevenness is too small on the surface, the dispersion value becomes low, and sufficient antiglare property may not appear, and the content of large particles When larger than said ratio, the space | interval between unevenness | corrugations is wide and the glare-proof property of the surface of a glare-proof layer can disappear partially.

  The composition for forming an antiglare layer is preferably a mixture of a reactive (meth) acrylate resin and particles in a weight ratio of 96.0: 4.0 to 98.5: 1.5. If the particles are contained in a larger amount than the above ratio, a problem of increasing the haze of the coating film can occur. If the particles are contained in a smaller amount than the above ratio, the problem that the antiglare property cannot be sufficiently exhibited. A point can be generated.

  The photoinitiator can be used without limitation as long as it is commonly used in the art.

  Specifically, 2-methyl-1- [4- (methylthio) phenyl] 2-morpholinepropanone-1, diphenyl ketone benzyl dimethyl ketal, 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, 4,4-diamino-benzophenone, 1- At least one selected from the group consisting of hydroxycyclohexyl phenyl ketone and benzophenone can be used.

  The composition for forming an antiglare layer further comprises at least one selected from the group consisting of a solvent, a photoinitiator, an antioxidant, a UV absorber, a light stabilizer, a labeling agent, a surfactant, and an antifouling agent. Can be included.

  The solvent is used for improving the coating property. Specifically, alcohols such as methanol, ethanol, isopropyl alcohol, butanol, isobutyl alcohol, methyl glycol, methyl glycol acetate, methyl cellosolve, ethyl cellosolve, butyl cellosolve; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diacetone alcohol, etc. Ketones; esters such as methyl formate, methyl acetate, ethyl acetate, ethyl lactate, butyl acetate; nitrogen-containing compounds such as nitromethane, N-methylpyrrolidone, N, N-dimethylformamide; propylene glycol monomethyl ether, diisopropyl ether, Ethers such as tetrahydrofuran, dioxane, dioxolane; methylene chloride, chloroform, trichloroethane, tetrachloro Halogenated hydrocarbons such as Tan; dimethyl sulfoxide, and other materials such as propylene carbonate. The solvents exemplified above can be used alone or in combination of two or more.

  The antiglare film comprises an antiglare layer formed by applying the composition for forming an antiglare layer on one surface of a transparent substrate film.

  Any film can be used as the transparent substrate as long as it is a transparent film. Specifically, as the transparent substrate, cycloolefin derivatives having units of monomers containing cycloolefin such as norbornene and polycyclic norbornene monomers, diacetylcellulose, triacetylcellulose, acetylcellulose butyllate, Cellulose selected from isobutyl ester cellulose, propionyl cellulose, butyryl cellulose or acetylpropionyl cellulose, ethylene-vinyl acetate copolymer, polyester, polystyrene, polyamide, polyetherimide, forliacryl, polyimide, polyethersulfone, polysulfone , Polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone Polyetheretherketone, polyethersulfone, polymethylmethacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyurethane, epoxy can be used, unstretched uniaxial or Biaxially stretched films can be used. Of these, a uniaxial or biaxially stretched polyester film excellent in transparency and heat resistance, a cycloolefin derivative film excellent in transparency and heat resistance, and capable of responding to an increase in size of the film, transparency And from the point that there is no optical anisotropy, a triacetyl cellulose film can be used suitably.

  The method for applying the composition for forming an antiglare layer on a transparent substrate is not particularly limited. For example, a method such as a die coater, an air knife, a reverse roll, a spray, a blade, a casting, a gravure, or a spin coating is used. Can do.

  The drying step of the composition for forming an antiglare layer can be performed at a temperature of 30 to 150 ° C. for 10 seconds to 1 hour, preferably 30 seconds to 10 minutes.

The curing stage of the composition for forming an antiglare layer can be photocuring, and the irradiation amount of UV light is about 0.01 to 10 J / cm ² , preferably 0.1 to ² J / cm ^2. Can be.

  The thickness of the antiglare layer formed on the transparent substrate is preferably 2.5 to 15 μm. When it is thinner than the above thickness, the hardness of the coating layer is insufficient, and when it is thicker than the above thickness, cracks can occur in the coating layer during handling.

The anti-glare layer formed after the curing has a height variation of 0.05 to 0.3 μm ² and a skewness of 0.5 to 2.0. At this time, the variance and skewness are calculated by the following formulas 1 and 2.

The variance has a correlation with the height of the unevenness, and the smaller the variance value, the lower the height of the unevenness. The anti-glare film according to the present invention has a dispersion value of the anti-glare layer height of 0.05 to 0.3 μm ² . When the variance is less than 0.05 μm ² , there is a problem that the antiglare property is lowered, and when it is more than 0.3 μm ² , there is a problem that haze is increased.

  The skewness has a correlation with the distribution of the surface height, and the smaller the skewness value, the smaller the unevenness distribution with the higher surface height. The antiglare film according to the present invention has an antiglare layer height having a skewness value of 0.5 to 2.0. When the skewness is less than 0.5, there is a problem that the unevenness distribution is small and the antiglare property is lowered, and when the skewness is more than 2.0, the unevenness distribution is large, There is a problem that the antiglare property becomes sharp.

  The present invention provides a polarizing plate 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 according to 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.

  Hereinafter, the present invention will be described more specifically with reference to the following examples and comparative examples. The following examples are only a part of specific examples of the present invention, and limit the protection scope of the present invention. It is not limited.

[Examples and Comparative Examples]
Production of Antiglare Layer-Forming Composition An antiglare layer-forming composition having the components and contents (parts by weight) shown in Table 1 below was produced.

Manufacture of anti-glare film in which anti-glare layer is formed on one surface of transparent substrate After stirring the composition for forming anti-glare layer prepared above for 6 hours, on a 60 μm thick triacetyl cellulose (TAC) film, Meyer After coating with a bar, the coating was dried at 100 ° C. for 1 minute and photocured using 400 mJ / cm ² ultraviolet rays to produce an antiglare film having an antiglare layer formed thereon.

  In order to compare the properties of the antiglare films produced above, the physical properties were measured as follows, and the results are shown in Table 2.

(1) Surface height dispersion and skewness measurement The surface height of the antiglare layer of the antiglare film produced in Production Example 2 was measured. The measurement uses a color 3D laser microscope (Keyence Corporation, VK-9510 product), the objective lens magnification of the microscope is set to 20 times, and the surface size of the measurement object is 675 μm (horizontal) × 506 μm (vertical) Set. All measured surface heights were extracted at 256 x 192 pixels using a program on a 3D microscope system.

  An average value of all the extracted surface heights was obtained, and a variance value and a skewness value were obtained using Equation 1 and Equation 2 below.

(2) Haze measurement The haze value of the antiglare film was measured using a haze meter (Murakami Co., Ltd.). The haze of the coating film has a correlation with the turbidity of the coating film, and the higher the haze, the more turbid the film is. The haze is preferably 10 or less.

(3) Measurement of transmission clarity The transmission clarity of the antiglare film was measured using a transmission clarity measuring device (Suga, ICM-1T product). The transmission sharpness was determined by adding the numerical values of the transmission sharpness of the slit intervals of 0.01 mm, 0.5 mm, 1.0 mm, and 2.0 mm. The value of the transmitted sharpness has a correlation with the sharpness, and the larger the numerical value of the transmitted sharpness, the clearer the image.

(4) Measurement of reflection sharpness After joining a black acrylic board on the anti-glare layer of the anti-glare film produced in Production Example 2, 45 using a sharpness meter (Suga, ICM-1T product). The reflection line brightness at a degree angle was measured. The reflection line brightness was obtained by adding the numerical values at slit intervals of 0.5 mm, 1.0 mm, and 2.0 mm. The value of the reflection definition is correlated with the antiglare property, and the smaller the value of the reflection definition is, the higher the antiglare property is.

(5) Anti-glare evaluation After joining a black acrylic plate on the anti-glare layer of the anti-glare film, reflect the three-wavelength standlight on the surface of the anti-glare layer, and confirm the degree of stand light shape clearly visible did.

-Evaluation method-
○: The shape of the stand light collapses and is visually recognized. Δ: The shape of the stand light is partially clearly visible. ×: The shape of the stand light is clearly visible.

Claims (7)

Comprising an antiglare layer formed by applying a composition for forming an antiglare layer comprising a reactive (meth) acrylate resin, translucent particles and a photoinitiator to one surface of a transparent substrate film;
The antiglare layer has a height variation value of 0.05 to 0.3 μm ² and a skewness value of 0.5 to 2.0. .   The composition for forming an antiglare layer is characterized in that a reactive (meth) acrylate resin and translucent particles are mixed in a weight ratio of 96.0: 4.0 to 98.5: 1.5. Item 2. An antiglare film according to Item 1.   The translucent particles include large particles and small particles, and the average particle size of the large particles is 1.05 to 1.25 times the thickness of the antiglare layer, and the average particle size of the small particles is The antiglare film according to claim 1, wherein the antiglare film is 0.5 to 0.9 times the average particle size of the large particles.   The anti-glare film according to claim 3, wherein the large particles and the small particles are mixed in a weight ratio of 25:75 to 75:25.   The composition for forming an antiglare layer comprises at least one selected from the group consisting of a solvent, a photoinitiator, an antioxidant, a UV absorber, a light stabilizer, a labeling agent, a surfactant, and an antifouling agent. The antiglare film according to claim 1, further comprising:   The antiglare film according to any one of claims 1 to 5, wherein the antiglare film has a haze of 1 to 10% and a transmission clarity of 200% or more.   A polarizing plate comprising the antiglare film according to claim 1.