JP2013257358A - Polarizing plate and image display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate that has anti-glare characteristics and has improved tightness of black during display of black in an image display device, and an image display device using the polarizing plate.SOLUTION: Provided is a polarizing plate in which at least one of protective films protecting both surfaces of a polarizing film has a layer containing fine particles and resin on a transparent film; the maximum sectional height of the surface of the protective films is 1.0 to 3.0 μm, and the average inclination angle is equal to or less than 1 degree; and values of the transmissive sharpness of the protective films measured through four optical sieves (widths: 2 mm, 1 mm, 0.5 mm, and 0.125 mm) are 70% or more, respectively. Also provided is an image display device using the polarizing plate.

Description

  The present invention relates to a polarizing plate and an image display device using the same, and more specifically, by specifying the maximum cross-sectional height, average inclination angle, and transparent clarity of a protective layer film that protects a polarizing film, anti-glare properties are achieved. The present invention relates to a polarizing plate having improved black tightening at the time of black display of an image display device and an image display device using the same.

  In recent years, liquid crystal display devices (LCD) have been widely used because they are thin, lightweight, and have low power consumption. The liquid crystal display device includes a liquid crystal cell and a polarizing plate. The polarizing plate is usually composed of a protective film and a protective film, and is obtained by dyeing a polarizing film made of a polyvinyl alcohol film with iodine, stretching, and laminating protective films on both sides thereof. In the transmissive liquid crystal display device, the polarizing plates are attached to both sides of the liquid crystal cell. In the reflective liquid crystal display device, the reflective plate, the liquid crystal cell, and the polarizing plate are usually arranged in this order.

  At present, a hard coat film having an antiglare property in which an antiglare layer is coated on a transparent film substrate is widely used as the protective film. In order to prevent reflection of an outside scene on the display surface, a hard coat film having antiglare properties is usually formed by applying a mixture of organic or inorganic fine particles and a binder resin or a curable resin to a substrate to form irregularities on the surface. As a result, antiglare properties are exhibited. In order to improve the antiglare property, it is necessary to increase the uneven shape or increase the frequency of the unevenness. However, if the irregularities are large or the frequency increases, the haze value (degree) of the anti-glare layer increases and anti-glare properties can be obtained, but the screen is blurred due to the reflection of external light, or the haze value increases. As a result, there has been a problem that the image definition is lowered and the visibility of the display image is deteriorated. Furthermore, when the haze value of the surface, which is a general evaluation of conventional anti-glare hard coat films, is lowered, the degree of white blurring due to the reflection of external light can be suppressed, but so-called scintillation (glare, As a technique to eliminate this, a method of increasing the haze value inside the antiglare layer was used, but due to the internal haze caused by the difference in refractive index between the fine particles and the resin The transmittance was lowered, the display brightness of the display device was lowered, and at the same time, the coating film became whitish due to the internal haze, so that the contrast was greatly lowered.

  For example, in Japanese Patent Application Laid-Open No. 11-326608 (Patent Document 1), the average particle diameter is 0.5 to 5.0 μm, and the difference in refractive index from the transparent resin is 0.02 to 0.20. An antiglare film containing translucent fine particles is disclosed. By setting the difference in refractive index between the translucent resin constituting the antiglare layer and the translucent fine particles contained therein to 0.02 to 0.20, an image can be obtained without reducing diffusion and antiglare properties. In this case, the image definition can be maintained high even if the haze value is increased to reduce glare. However, the haze of the film specifically obtained is as high as 10% or more and has an antiglare property, while the coating film becomes whitish and the transmittance and contrast are remarkably reduced.

  Japanese Patent Application Laid-Open No. 2008-286878 (Patent Document 2) discloses that, in an antiglare film, the difference in refractive index between a cured binder and a light-transmitting fine particle is as small as 0 to 0.05. Therefore, the light transmittance in the antiglare hard coat layer can be improved, and the arithmetic average roughness (Ra) measured in accordance with JIS B 0601-1994 on the surface of the antiglare hard coat layer. Is suppressed to a small range of 0.01 to 0.30 μm and the average interval of unevenness (Sm) of 10 to 300 μm, while diffusing light on the surface (outer surface) of the antiglare hard coat layer, Light transmittance can be maintained, and the anti-glare film is said to be able to exhibit a good balance between suppression of glare and improvement of transmission clarity. However, the arithmetic average roughness (Ra) is 0.01 to 0.30 μm and the average interval of unevenness (Sm) is not so small as 10 to 300 μm, and most of the antiglare films currently on the market are Applicable to the range. In addition, the film obtained specifically has an arithmetic average roughness (Ra) of 0.1 μm or more, an image sharpness value measured through an optical comb having a width of 2 mm is less than 70%, and 60 ° reflection. When the measured image sharpness value is 60% or less, the antiglare property is not sufficient, but glare prevention on the high-definition panel is insufficient, and the whiteness of the coating film is not taken into consideration. The problem remains that the contrast is significantly reduced.

JP 11-326608 A JP 2008-286878 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a polarizing plate that has anti-glare properties and has improved black tightening during black display of an image display device, and an image display device using the same.

The present invention provides the following [1] to [2].
[1] A polarizing plate having a polarizing film and two protective films protecting both surfaces of the polarizing film, wherein at least one of the protective films has a layer containing fine particles and a resin on a transparent film And the maximum represented by the difference between the maximum height in the evaluation area and the minimum height in the evaluation area when the average value of the height in the evaluation area on the surface of the protective film is zero. The cross-sectional height is 1.0 to 3.0 μm, the average inclination angle of the unevenness on the surface of the protective film is 1 degree or less, and further, a transmission sharpness measuring device based on JIS K 7105-1981 of the protective film is used. A polarizing plate characterized by having a transmission sharpness value measured through four optical combs (width 2 mm, 1 mm, 0.5 mm, 0.125 mm) of 70% or more.
[2] An image display device using the polarizing plate according to [1].

  ADVANTAGE OF THE INVENTION According to this invention, while having anti-glare property, the polarizing plate which improved the black tightening at the time of black display of an image display apparatus, and an image display apparatus using the same can be provided.

  Hereinafter, embodiments of the present invention will be described in detail.

  The polarizing plate of the present invention is a polarizing plate having a polarizing film and two protective films protecting both surfaces of the polarizing film, and the polarizing film is dyed with iodine or a dye and stretched. A polyvinyl formal film, a polyvinyl acetal film, an ethylene-vinyl acetate copolymer saponified film, and the like, wherein at least one of the protective films has a layer containing fine particles and a resin on a transparent film, and Maximum cross-section height expressed by the difference between the maximum height in the evaluation area and the minimum height in the evaluation area when the average height in the evaluation area on the surface of the protective film is zero. 1.0 to 3.0 μm, the average inclination angle of the irregularities on the surface of the protective film is 1 degree or less, and a transmission sharpness measuring device based on JIS K 7105-1981 of the protective film The transmission sharpness values measured through the four optical combs (width 2 mm, 1 mm, 0.5 mm, 0.125 mm) are 70% or more each. The image display device of the present invention includes a transmissive display body and a light source device that irradiates the transmissive display body from the back surface, and the polarizing plate according to the present invention is formed on the surface of the transmissive display body. It has been made. The image display device is used for a transmissive display device, and is used for display display of a television, a computer, a word processor, or the like. In particular, it is used on the outermost surface of a high-definition image display such as a cathode ray tube display (CRT), a plasma display (PDP), an electroluminescence display (ELD), or a liquid crystal display (LCD).

Here, “maximum cross-sectional height” is as defined above, but as defined in JIS B0601, it is a value calculated from the cross-sectional curve (measurement curve) of the film surface that is the object of measurement. is there. The surface of the antiglare hard coat film provided with the antiglare hard coat layer containing the fine particles and the resin as in the present invention has not only fine irregular shapes but also undulations. A measurement curve (usually called a cross-section curve) measured with a surface roughness measuring machine is between a waviness curve and a roughness curve.
There is a relationship of cross-sectional curve = waviness curve + roughness curve. Therefore, the “maximum cross-sectional height” in the present invention evaluates a cross-sectional curve including a “surface waviness component”. In the 2001 version of JIS, the maximum cross-sectional height is represented by the symbol “Pt”.

In addition, the above “average inclination angle” refers to the slope of a line segment that divides a cross-sectional curve (measurement curve) of the film surface to be measured at a constant interval ΔX and connects the start points of the cross-sectional curves in each section. (Inclination angle: The inclination angle is obtained by calculating the absolute value of tan ⁻¹ (determined by ΔYi / ΔX) and averaging the values (θa) (see FIG. 1), that is, the average inclination angle (θa ) Is a value defined by the following formula.

  The reason why the polarizing plate using the protective film of the present invention and the image display device using the same are excellent in antiglare property and black tightening at the time of black display of the image display device is presumed as follows.

  The haze value of the protective film is generated by light being refracted and scattered due to irregularities on the surface of the transparent film containing fine particles and a resin (hereinafter sometimes referred to as “antiglare hard coat layer”). There is surface haze and internal haze caused by light being refracted and scattered due to the presence of fine particles in the antiglare hard coat layer, and the average value of the height in the evaluation area of the surface of the protective film is zero (0), the maximum cross-sectional height represented by the difference between the maximum height in the evaluation region and the minimum height in the evaluation region is 1.0 to 3.0 μm, and the surface of the protective film When the average inclination angle of the unevenness is 1 degree or less, the surface property such as the undulation of the specific region or the gentle (loose) surface unevenness can be obtained, and the refraction and scattering of light caused by the unevenness of the surface can be suppressed. Therefore, surface haze is difficult to express Because it can suppress the loss of light due to light refraction and scattering, it can suppress the decrease in transmittance, and the protective film is whitish and cloudy due to the scattered light on the antiglare hard coat layer surface, so it has excellent transparency it is conceivable that.

  In addition, when the maximum cross-sectional height of the surface of the protective film exceeds 3.0 μm, refraction and scattering of light due to unevenness on the surface is strengthened, so that surface haze is easily developed, and light refraction and scattering are caused by light refraction and scattering. Loss of transmittance is a concern due to loss, and it is easy to obtain antiglare properties due to scattered light on the surface of the antiglare hard coat layer, but it is difficult to suppress the phenomenon that the antiglare hard coat film becomes whitish and cloudy. And transparency are apt to decrease.

  Further, the lower limit of the maximum cross-sectional height is not particularly limited, but when the maximum cross-sectional height is less than 1.0 μm, the unevenness of the film surface becomes too small, and thus the scattered light on the surface of the antiglare hard coat layer. It becomes difficult to obtain the antiglare property due to.

  Further, when the average inclination angle is larger than 1 degree (more than 1 degree), refraction and scattering of light due to surface unevenness is enhanced, so that surface haze is easily developed, and light loss due to refraction and scattering of light. As a result, there is concern about a decrease in transmittance, and anti-glare properties due to scattered light on the surface of the anti-glare hard coat layer can be easily obtained, but it is difficult to suppress the phenomenon that the protective film becomes whitish, so transparency and clear transmission are clear. There is a problem that the degree tends to decrease.

  Accordingly, in the present invention, the maximum cross-sectional height of the surface of the protective film is preferably 1.0 μm or more and 3.0 μm or less, and more preferably the maximum cross-sectional height is 1.2 μm or more and 2.5 μm or less. It is.

  The average inclination angle of the protective film surface is preferably 1 degree or less, more preferably the average inclination angle is 0.9 degree, and still more preferably the average inclination angle is 0.7 degree or less. . Although there is no restriction | limiting in particular about the lower limit of the said average inclination angle, From a glare-proof viewpoint, it is preferable that it is 0.1 degree or more.

  In the present invention, the “evaluation region” is a measurement region.

  Moreover, in the anti-glare hard coat film of the present invention, it is measured through four optical combs (width 2 mm, 1 mm, 0.5 mm, 0.125 mm) using a transmission sharpness measuring device based on JIS K 7105-1981. By setting each of the transmission sharpness values to 70% or more, the image sharpness is high, the whitishness (white blur) of the coating film is reduced, the contrast is suppressed, and the visibility of the display can be improved. .

  The transparent film that can be used in the present invention is not particularly limited. For example, a polyethylene terephthalate film (PET; refractive index 1.665), a polycarbonate film (PC; refractive index 1.582), a triacetyl cellulose film (TAC) ; Refractive index 1.485), norbornene film (NB; refractive index 1.525) can be used, and the film thickness is not particularly limited, but about 25 μm to 250 μm is generally used. Since the refractive index of a general ionizing radiation curable resin is about 1.52, a TAC film or NB film close to the refractive index of the resin is preferable in order to increase the visibility. A PET film is preferred.

  The resin used in the present invention can be used without particular limitation as long as it is a resin that forms a film. In particular, it imparts hard properties (pencil hardness, scratch resistance) to the surface of the antiglare hard coat layer, and also provides antiglare hard. An ionizing radiation curable resin is preferred in that a large amount of heat is not required when forming the coat layer. In addition, the antiglare hard coat layer is a leveling agent, antifoaming agent, lubricant, ultraviolet absorber, light stabilizer, polymerization inhibitor, wetting and dispersing agent, rheology control agent, antioxidant as long as the effect of the present invention is not changed. An agent, an antifouling agent, an antistatic agent, a conductive agent and the like may be contained as necessary.

  The ionizing radiation curable resin is not particularly limited as long as it is a transparent resin that is cured by irradiation with an electron beam or ultraviolet rays. For example, a urethane acrylate resin, a polyester acrylate resin, and an epoxy acrylate resin It can select suitably from resin etc. Preferred examples of the ionizing radiation curable resin include those composed of an ultraviolet curable polyfunctional acrylate having two or more (meth) acryloyl groups in the molecule. Specific examples of the UV curable polyfunctional acrylate having two or more (meth) acryloyl groups in the molecule include neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and trimethylol. Polyol polyacrylates such as propane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, bisphenol A diglycidyl Epoxys such as diacrylate of ether, diacrylate of neopentyl glycol diglycidyl ether, di (meth) acrylate of 1,6-hexanediol diglycidyl ether ( A) Polyester (meth) acrylate, polyhydric alcohol, polyisocyanate and hydroxyl group-containing (meta) which can be obtained by esterifying acrylate, polyhydric alcohol and polyhydric carboxylic acid and / or anhydride and acrylic acid ) Urethane (meth) acrylate obtained by reacting acrylate, polysiloxane poly (meth) acrylate, and the like.

  The ultraviolet curable polyfunctional acrylate may be used alone or in combination of two or more, and the content thereof is preferably 50 to 95% by weight with respect to the resin solid content of the antiglare hard coat layer coating material. is there. In addition to the polyfunctional (meth) acrylate, preferably 10% by weight or less of 2-hydroxy (meth) acrylate, 2-hydroxypropyl (meth) based on the resin solid content of the antiglare hard coat layer coating. ) Monofunctional acrylates such as acrylate and glycidyl (meth) acrylate can also be added.

  In addition, a polymerizable oligomer used for the purpose of adjusting the hardness can be added to the antiglare hard coat layer. Examples of such oligomers include terminal (meth) acrylate polymethyl (meth) acrylate, terminal styryl poly (meth) acrylate, terminal (meth) acrylate polystyrene, terminal (meth) acrylate polyethylene glycol, terminal (meth) acrylate acrylonitrile-styrene copolymer. Macromonomers such as polymers and terminal (meth) acrylate styrene-methyl methacrylate copolymers can be mentioned, and the content thereof is preferably 5 to 50 weights based on the resin solid content in the antiglare hard coat coating material. %.

  The material for forming the fine particles used in the present invention is not particularly limited. For example, silica (refractive index 1.420 to 1.460), vinyl chloride resin (refractive index 1.530), acrylic resin (refractive index 1.. 490), (meth) acrylic resin (refractive index 1.520 to 1.530), polystyrene resin (refractive index 1.590), melamine resin (refractive index 1.650), polyethylene resin, polycarbonate resin, acrylic-styrene copolymer. Resin (refractive index 1.490-1.590) etc. can be mentioned, A microparticle may be used independently or it is also possible to use 2 or more types together. Further, the refractive index of the fine particles is not limited, but in order to further obtain the effects of the present invention, the fine particles have a refractive index difference of 0.001 with respect to the refractive index of the resin used for the antiglare hard coat layer. It is preferable to use fine particles having a refractive index of ˜0.200, and it is more preferable to use fine particles having a refractive index difference of 0.001 to 0.100.

  In the present invention, the coating thickness of the antiglare hard coat layer is preferably 0.5 to 1.5 times the average particle size of the fine particles constituting the antiglare hard coat layer, more preferably 0. .8 to 1.2 times. The average particle size of the fine particles is preferably 1.0 to 4.0 μm, and the average particle size of the fine particles is more preferably 3.0 to 4.0 μm in order to impart high pencil hardness.

When the coating film thickness is less than 0.5 times the average particle size of the fine particles constituting the antiglare hard coat layer, the fine particles are not fixed in the coating film, and the hardness of the coating film surface is remarkably deteriorated.
On the other hand, when the coating thickness exceeds 1.5 times the average particle size of the fine particles constituting the antiglare hard coat layer, no antiglare property can be obtained. The average particle diameter of the fine particles can be measured by, for example, a laser diffraction scattering method.

  Further, when the average particle size of the fine particles is 4 μm or more, the antiglare is more than necessary when the coating thickness of the antiglare hard coat layer is set to 0.5 to 1.5 times the average particle size of the fine particles. And the scattering of external light on the surface of the coating film becomes large, and the surface becomes whitish due to the scattering of light, and the visibility of the display is remarkably lowered. On the other hand, when the average particle size of the fine particles is smaller than 1.0 μm, the coating film thickness must be reduced, so that the hard property is lacking.

  In the present invention, the fine particles are preferably blended in the antiglare hard coat layer in an amount of 0.05 to 3 parts by weight, more preferably 0.075 to 1 part by weight based on 100 parts by weight of the resin. Preferably, 0.1 to 0.5 part by weight is blended.

  When the amount of fine particles is less than 0.05 parts by weight with respect to 100 parts by weight of the resin, the coating thickness of the antiglare hard coat layer is 0.5 to 1.5 times the average particle size of the fine particles. When set, no antiglare property is obtained. Moreover, when the compounding quantity of microparticles exceeds 3 weight part with respect to 100 weight part of said resin, a haze value will become high and the transmittance | permeability and contrast will fall.

  Therefore, as described above, the protective film of the present invention has a layer containing fine particles and a resin on the transparent film, and the average value of the height in the evaluation region of the surface of the protective film is zero. The maximum cross-sectional height represented by the difference between the maximum height in the evaluation region and the minimum height in the evaluation region is 1.0 to 3.0 μm, and the average inclination angle of the unevenness on the surface of the protective film is 1 The transmission sharpness value measured through four optical combs (width 2 mm, 1 mm, 0.5 mm, 0.125 mm) using a transmission sharpness measuring device based on JIS K 7105-1981 of the protective film The fine particles have an average particle size of 1.0 to 4.0 μm, and the coating thickness of the antiglare hard coat layer is equal to the average particle size of the fine particles. 0.5 to 1.5 times It is preferable amount of the child is 0.05 to 3 parts by weight based on 100 parts by weight of the resin. Moreover, it is preferable that the haze value of this protective film is 0.1-5.0%, More preferably, a haze value is 0.1-3.5%, More preferably, a haze value is 0.1-0.1%. 2.0%.

  The antiglare hard coat layer can be formed by applying and drying a paint obtained by dissolving and dispersing the resin and fine particles in a solvent on a transparent film. The solvent can be appropriately selected depending on the solubility of the resin, and may be any solvent that can uniformly dissolve or disperse at least solids (resin, fine particles, catalyst, curing agent, and other additives). Examples of such solvents include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons ( Cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (methanol, ethanol, isopropanol, Butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides, amides and the like. Further, the solvents may be used alone or in combination.

  The coating method of the anti-glare hard coat layer is not particularly limited, but the coating thickness can be adjusted by gravure coating, micro gravure coating, bar coating, slide die coating, slot die coating, dip coating, etc. Coating is possible with an easy method. The film thickness of the coated antiglare hard coat layer can be measured by observing a cross-sectional photograph of the antiglare film with a microscope or the like and actually measuring from the coating film interface to the surface.

  In the protective film of the present invention, the 60 ° specular gloss is preferably 70% or more and 95% or less, and the 20 ° specular gloss is preferably 30% or more and 90% or less. Further, the luminous transmittance ( The transmission Y value) is preferably 92.00 or more.

  In the protective film of the present invention, in addition to the antiglare hard coat layer containing fine particles and resin, a functional layer such as an antireflection layer or an antistatic layer can be provided on the transparent film. However, by providing such a functional layer, surface undulations may be canceled and the desired anti-glare property may not be obtained, so a functional layer is provided on the anti-glare hard coat layer containing fine particles. In this case, the thickness of the functional layer is desirably 0.5 μm or less.

  It is also possible to provide a functional layer under the antiglare hard coat layer. Examples of the functional layer include a refractive index control layer for improving the antireflection function, an easy adhesion layer for obtaining adhesion between the base material and the antiglare hard coat layer, and an antistatic layer.

  In the protective film of the present invention, in addition to the antiglare hard coat layer containing fine particles and a resin, a functional layer such as an antireflection layer or an antistatic layer is provided on the transparent film. When provided on the coat layer, if the coating thickness of the antiglare hard coat layer is set to be equal to or less than the average particle size of the fine particles constituting the antiglare hard coat layer, the antiglare hard coat layer and the functional layer are combined. The applied coating thickness needs to be 0.5 to 1.5 times the average particle size of the fine particles constituting the antiglare hard coat layer.

  The protective film of the present invention is a protective film in the case where a functional layer such as an antireflection layer or an antistatic layer is provided on the antiglare hard coat layer containing fine particles and resin on the transparent film. Maximum represented by the difference between the maximum height in the evaluation area and the minimum height in the evaluation area when the average height in the evaluation area of the surface, that is, the surface of the functional layer is zero. It is necessary that the cross-sectional height is 1.0 to 3.0 μm and the average inclination angle of the irregularities on the surface of the functional layer is 1 degree or less.

  The following examples illustrate the invention, but are not intended to limit the invention.

  The average particle size of the fine particles was measured with a laser diffraction particle size analyzer SALD2200 (manufactured by Shimadzu Corporation). The thickness of the coating film was measured by observing the cross section with a scanning electron microscope manufactured by Keyence Corporation. Unless otherwise specified, “parts” and “%” described below represent “parts by weight” and “% by weight”, respectively.

[Example 1]
<Preparation of paint>
To 70.0 g of toluene, 0.09 g of acrylic-styrene copolymer particles (manufactured by Sekisui Plastics Co., Ltd., average particle size 2.0 μm, refractive index: 1.525) was added and stirred sufficiently. In this solution, 27.45 g of an acrylic ultraviolet curable resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., refractive index: 1.52) and Irgacure 184 (photopolymerization initiator, manufactured by Ciba Specialty Chemical Co., Ltd.) 50 g, 0.96 g of BYK325 (leveling agent, manufactured by Big Chemie Co., Ltd.) was added, and the mixture was sufficiently stirred to prepare a paint.
<Protective film production>
The above-mentioned paint was applied to Fuji TAC (triacetylcellulose film, manufactured by Fuji Film Co., Ltd.) with Meyer bar # 4 (manufactured by RDS), dried at 80 ° C. for 1 minute, and then irradiated with 350 mJ / cm ² ultraviolet light (light source) : UV lamp manufactured by Fusion Japan) and cured. The thickness of the obtained coating film was 1.6 μm.

[Example 2]
<Preparation of paint>
Example 1 except that the acrylic-styrene copolymer particles used in Example 1 were changed to melamine resin-silica composite particles (manufactured by Nissan Chemical Industries, Ltd., average particle size 2.0 μm, refractive index 1.650). A paint was prepared in the same manner as described above.
<Protective film production>
A protective film was produced in the same manner as in Example 1. The thickness of the obtained coating film was 1.6 μm.

[Example 3]
<Preparation of paint>
To 80.00 g of toluene, 0.02 g of acrylic particles (manufactured by Soken Chemical Co., Ltd., average particle size 1.5 μm, refractive index: 1.49) was added and sufficiently stirred. Acrylic UV curable resin (Toyo Ink Mfg. Co., Ltd., refractive index: 1.49) 18.02 g and Irgacure 184 (photopolymerization initiator, Ciba Specialty Chemicals Co., Ltd.) 1.00 g BYK325 (leveling agent, manufactured by Big Chemie Co., Ltd.) (0.96 g) was added and sufficiently stirred to prepare a paint.
<Protective film production>
A protective film was produced in the same manner as in Example 1. The thickness of the obtained coating film was 1.2 μm.

[Example 4]
<Preparation of paint>
The same method as in Example 1 except that the acrylic-styrene copolymer particles used in Example 1 were changed to particles having an average particle size of 3.0 μm (manufactured by Sekisui Plastics Co., Ltd., refractive index 1.525). A paint was prepared.
<Protective film production>
A protective film was produced in the same manner as in Example 1 except that the Mayer bar used in Example 1 was changed to # 5. The thickness of the obtained coating film was 3.4 μm.

[Example 5]
<Preparation of paint>
To 70.0 g of toluene, 0.75 g of acrylic-styrene copolymer particles (manufactured by Sekisui Plastics Co., Ltd., average particle size 2.0 μm, refractive index: 1.525) was added and stirred sufficiently. 26.79 g of acrylic ultraviolet curable resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., refractive index: 1.52) and Irgacure 184 (photopolymerization initiator, manufactured by Ciba Specialty Chemicals Co., Ltd.) 50 g, 0.96 g of BYK325 (leveling agent, manufactured by Big Chemie Co., Ltd.) was added, and the mixture was sufficiently stirred to prepare a paint.
<Protective film production>
A protective film was produced in the same manner as in Example 1. The thickness of the obtained coating film was 1.6 μm.

[Example 6]
<Preparation of paint>
To 70.0 g of toluene, 0.02 g of acrylic-styrene copolymer particles (manufactured by Sekisui Plastics Co., Ltd., average particle size 2.0 μm, refractive index: 1.525) was added and stirred sufficiently. In this solution, 27.52 g of an acrylic ultraviolet curable resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., refractive index: 1.52) and Irgacure 184 (photopolymerization initiator, manufactured by Ciba Specialty Chemical Co., Ltd.) 50 g, 0.96 g of BYK325 (leveling agent, manufactured by Big Chemie Co., Ltd.) was added, and the mixture was sufficiently stirred to prepare a paint.
<Protective film production>
A protective film was produced in the same manner as in Example 1. The thickness of the obtained coating film was 1.6 μm.

[Example 7]
<Preparation of paint>
To 45.0 g of toluene, 0.17 g of acrylic-styrene copolymer particles (manufactured by Sekisui Plastics Co., Ltd., average particle size 4.0 μm, refractive index: 1.525) was added and stirred sufficiently. In this solution, 51.12 g of an acrylic ultraviolet curable resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., refractive index: 1.52) and Irgacure 184 (photopolymerization initiator, manufactured by Ciba Specialty Chemicals Co., Ltd.) 75 g, 0.96 g of BYK325 (leveling agent, manufactured by Big Chemie Co., Ltd.) was added, and the mixture was sufficiently stirred to prepare a paint.
<Protective film production>
A protective film was produced in the same manner as in Example 1. The thickness of the obtained coating film was 3.6 μm.

[Example 8]
<Preparation of paint>
0.18 g of acryl-styrene copolymer particles (manufactured by Sekisui Plastics Co., Ltd., average particle size 3.3 μm, refractive index: 1.525) was added to 65.0 g of butyl acetate and sufficiently stirred. Acrylic ultraviolet curable resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., refractive index: 1.52) 32.50 g and Irgacure 184 (photopolymerization initiator, manufactured by Ciba Specialty Chemicals Co., Ltd.) 75 g and 0.57 g of BYK325 (leveling agent, manufactured by Big Chemie Co., Ltd.) were added and stirred sufficiently to prepare a coating material.
<Protective film production>
A protective film was produced in the same manner as in Example 1 except that the Meyer bar used in Example 1 was changed to # 6. The thickness of the obtained coating film was 2.9 μm.

[Comparative Example 1]
<Preparation of paint>
To 82.00 g of toluene, 0.18 g of acrylic-styrene copolymer particles (manufactured by Sekisui Plastics Co., Ltd., average particle size: 3.0 μm, refractive index: 1.525) was added and sufficiently stirred. Acrylic ultraviolet curable resin (Nippon Synthetic Chemical Industry Co., Ltd., refractive index: 1.52) 15.96 g and Irgacure 184 (photopolymerization initiator, Ciba Specialty Chemical Co., Ltd.) 90 g and 0.96 g of BYK325 (leveling agent, manufactured by Big Chemie Co., Ltd.) were added and sufficiently stirred to prepare a paint.
<Protective film production>
A protective film was produced in the same manner as in Example 1. The thickness of the obtained coating film was 1.2 μm.

[Comparative Example 2]
<Preparation of paint>
0.45 g of acrylic-styrene copolymer particles (manufactured by Sekisui Plastics Co., Ltd., average particle size: 3.0 μm, refractive index: 1.525) was added to 52.5 g of toluene and sufficiently stirred. In this solution, 43.69 g of an acrylic ultraviolet curable resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., refractive index: 1.52) and Irgacure 184 (photopolymerization initiator, manufactured by Ciba Specialty Chemicals Co., Ltd.) 38 g, BYK325 (leveling agent, manufactured by Big Chemie Co., Ltd.) (0.96 g) was added, and the mixture was sufficiently stirred to prepare a paint.
<Protective film production>
A protective film was produced in the same manner as in Example 8. The thickness of the obtained coating film was 6.9 μm.

[Comparative Example 3]
<Preparation of paint>
Acrylic-styrene particles (manufactured by Sekisui Plastics Co., Ltd., average particle size 2.0 μm, refractive index: 1.525) were added to 70.0 g of toluene, and the mixture was sufficiently stirred. Acrylic ultraviolet curable resin (Nippon Synthetic Chemical Industry Co., Ltd., refractive index: 1.52) 24.54 g and Irgacure 184 (photopolymerization initiator, Ciba Specialty Chemicals Co., Ltd.) 50 g, 0.96 g of BYK325 (leveling agent, manufactured by Big Chemie Co., Ltd.) was added, and the mixture was sufficiently stirred to prepare a paint.
<Protective film production>
A protective film was produced in the same manner as in Example 1. The thickness of the obtained coating film was 1.8 μm.

[Comparative Example 4]
<Preparation of paint>
60.0 g of toluene, 33.0 g of acrylic UV curable resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., refractive index: 1.520) and Irgacure 184 (photopolymerization initiator, manufactured by Ciba Specialty Chemicals Co., Ltd.) 1.50 g and 0.50 g of BYK325 (leveling agent, manufactured by Big Chemie Co., Ltd.) were added and sufficiently stirred to prepare a paint.
<Protective film production>
A protective film was produced in the same manner as in Example 1. The thickness of the obtained coating film was 3.4 μm.

[Comparative Example 5]
<Preparation of paint>
The same method as in Example 1 except that the acrylic-styrene copolymer particles used in Example 1 were changed to particles having an average particle diameter of 5.0 μm (manufactured by Sekisui Plastics Co., Ltd., refractive index 1.525). A paint was prepared.
<Protective film production>
A protective film was produced in the same manner as in Example 1 except that the Meyer bar used in Example 1 was changed to # 10. The thickness of the obtained coating film was 5.6 μm.

  The antiglare hard coat films of Examples and Comparative Examples produced as described above were evaluated for the following items, and the results are summarized in the table below.

(1) Maximum cross-sectional height It was measured using a three-dimensional surface roughness meter “VertScan2.0” manufactured by Ryoka System Co., Ltd. The maximum height value (P) in the evaluation region and the minimum height value (V) in the evaluation region when the average value (Ave) of the height in the evaluation region of the region cross-sectional curve parameter obtained by measurement is zero. ) To determine the maximum cross-sectional height (Pt). The measurement conditions are set as follows.
<Optical conditions>
Camera: SONY HR-50 1/3 type Objective: 10 x (10 times)
Tube: 1 x Body
Relay: No Relay
Filter: 530 white
-Light quantity adjustment: Automatically performed so that the value of Lamp falls within the range of 50-95.
<Measurement conditions>
Mode: Wave
Size: 640 × 480
Range (μm): Start (5), Stop (−10)

(2) Average inclination angle The average inclination angle of the concavo-convex portions on the film surface was measured using a three-dimensional surface roughness meter “VertScan2.0” manufactured by Ryoka System Co., Ltd.

(3) Haze value The haze value was measured using a haze meter “HM150” manufactured by Murakami Color Research Laboratory.

(4) Luminous transmittance (transmission Y value)
Murakami Color Research Laboratory “integrated sphere high-speed spectral transmission measurement system DOT-3” was used, and the measurement was carried out according to JISZ8722.

  Here, the luminous transmittance is obtained from Y = K∫S (λ) y (λ) T (λ) dλ. S (λ): spectral distribution of wavelength 400 to 700 nm, y (λ): color matching function, T (λ): spectral solid angle transmittance, Y: luminous transmittance.

(5) Transmission clarity Measurement was carried out using a Suga Test Instruments Co., Ltd. image clarity measuring device “ICM-1DP”. The measurement was performed using an optical comb having widths of 2 mm, 1 mm, 0.5 mm, and 0.125 mm, and the measured values at each width and the sum thereof were calculated.

(6) Glossiness (20 degrees, 60 degrees)
Using a gloss meter (GM-3D) manufactured by Murakami Color Research Laboratory, apply a black vinyl tape (Nitto Vinyl Tape, PROSELF No. 21 (wide)) to the opposite side of the coating and measure the glossiness at 20 or 60 degrees. did.

(7) Pencil hardness It carried out based on JISK5400 using HEIDON14 by Shinto Scientific.

(8) Glitter Each protective film was layered on a liquid crystal display (LCD) having a resolution of 150 ppi that was displayed in green on the entire surface, and the degree of occurrence of glittering screen was visually evaluated. In addition, a clear type hard coat film which does not generate glare was previously set on the LCD surface. The case where there was no glare and the case where the glare was slight was designated as “◯”, and the case where the glare was large and the visibility deteriorated was designated as “X”.

(9) White bokeh, whitish White bokeh due to reflection of external light is applied with a black vinyl tape (Nitto Vinyl Tape, PROSELF No. 21 (wide)) on the opposite side of the coating as black density using a Macbeth densitometer. It was measured. 2.15 or more is “◯”, 2.10 or more and less than 2.15 is “Δ”, and less than 2.10 is “x”. In addition, the whitishness of the coating film due to the transmitted light is that the coating surface is on the observer side, and when the white fluorescent lamp is viewed through the protective film, light diffuses in the film due to internal haze. The state which became whitish was visually evaluated. Those with no whiteness and slight whiteness were indicated with “◯”, those with a slight whiteness were indicated with “△”, and those with a white coating film were indicated with “X”.

(10) Anti-glare property Anti-glare property is a line width drawn through an anti-glare hard coat film with 10 straight lines drawn at 1mm width intervals reflected on the coated surface of the protective film, with the coated surface facing the observer. The state where the line width is blurred and difficult to see due to light scattering was visually evaluated. “◯” indicates that the line width cannot be recognized, and “X” indicates that the line width can be recognized.

(11) Black tightening during black display (display performance)
The surface film on the viewing side provided in the liquid crystal display device (32 "TV: AQUIOS-LC32P1, manufactured by Sharp Corporation) using a VA liquid crystal cell is peeled off, and the above protective film is used instead of the coating surface on the viewing side. The liquid crystal display device was displayed in black in a 300 lux bright room and evaluated visually, and the following judgment was made. Cannot be felt, black display with low brightness and excellent contrast under bright room is `` ○ '', while white display is too bright and unacceptable as black display, bright room “×” indicates low contrast.

Claims (2)

  A polarizing plate having a polarizing film and two protective films protecting both surfaces of the polarizing film, wherein at least one of the protective films has a layer containing fine particles and a resin on a transparent film, and Maximum cross-section height expressed by the difference between the maximum height in the evaluation area and the minimum height in the evaluation area when the average height in the evaluation area on the surface of the protective film is zero. Is 1.0 to 3.0 μm, and the average inclination angle of the unevenness on the surface of the protective film is 1 degree or less, and further, using a transmission sharpness measuring device based on JIS K 7105-1981, A polarizing plate, wherein each of the values of transmitted sharpness measured through an optical comb (width 2 mm, 1 mm, 0.5 mm, 0.125 mm) is 70% or more.   An image display device using the polarizing plate according to claim 1.