JP2011174976A - Antiglare film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antiglare film which has high contrast when it is disposed on a liquid crystal display surface and finger print wiping-off performance, and which suppresses electrification without using an expensive antistatic agent when a protection film is peeled. <P>SOLUTION: The antiglare film includes a transparent base material and an antiglare layer provided on one surface of the base material. The antiglare film is characterized in that: the total haze (Hz) is in the range of 1.0-8.0%; the reduction rate of contrast under darkroom conditions is ≤3.0%; the contact angle to water after being subjected to an alkali treatment is 90-140°; and the absolute value of frictional electrification voltage is ≤1.0 kV. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an antiglare film provided on the surface of a window or a display. In particular, the present invention relates to an antiglare film provided on the surface of a display such as a liquid crystal display (LCD), a CRT display, an organic electroluminescence display (ELD), a plasma display (PDP), a surface electric field display (SED), or a field emission display (FED). .

  In displays such as liquid crystal displays, CRT displays, EL displays, and plasma displays, an anti-glare film having a concavo-convex structure on the surface is displayed in order to prevent deterioration in visibility due to external light being reflected on the display surface during viewing. It is known to provide on the surface.

As a technique for forming an antiglare film, for example, a coating liquid in which particles are mixed in a binder matrix forming material is applied, and the particles are dispersed in the binder matrix, thereby forming an uneven structure on the surface of the antiglare film. A technique is known (Patent Document 1).
In the antiglare film having the concavo-convex structure thus formed on the surface, the external light incident on the antiglare film is scattered by the surface concavo-convex structure, so that the image of the external light becomes unclear and the external light is applied to the display surface. It becomes possible to prevent a decrease in visibility due to reflection.

Various techniques are disclosed for an antiglare film using a binder matrix and particles. For example, the following techniques are disclosed.
A technology that uses a binder matrix resin, spherical particles, and amorphous particles in combination (Patent Document 2).
A technique using a binder matrix resin and a plurality of particles having different particle diameters (Patent Document 3).

  The following techniques are also disclosed. By providing an uneven structure on the surface, it is possible to prevent a drop in visibility due to the reflection of external light, but at the same time as an internal haze is provided as a method to eliminate the trade-off relationship that glare occurs. Although there is a technique for suppressing the lens effect that causes the glare by scattering, there is a problem that the contrast is lowered due to scattering of transmitted light (Patent Document 4).

Further, in addition to the adsorption of dust and the generation of static electricity due to the surface charge of the display, in the liquid crystal display, the VA (Vertical Alignment) mode in which charges are applied in the horizontal direction and the IPS (In-Plane Switching) mode are disturbed by static electricity. Although there is a technique for imparting antistatic properties to suppress the above-mentioned, the above effect is weak because the polarizing plate exists between the liquid crystal cell and the antistatic layer formed on the outermost surface because of a decrease in transmittance. There is a problem that the generation of static electricity cannot be prevented (Patent Document 5).

  Therefore, there is also a technique for imparting antistatic properties to an adhesive layer that bonds a liquid crystal cell and a polarizing plate closer to the liquid crystal cell, instead of the antiglare film on the outermost surface (Patent Document 6).

Thus, the anti-glare film of various structures is disclosed for various purposes.
The performance of the antiglare film used on the front surface of the display varies depending on the display. In other words, the optimum antiglare film varies depending on the resolution of the display and the purpose of use. Therefore, various anti-glare films are required according to the purpose.

JP-A-6-18706 JP 2003-260748 A JP 2004-004777 A JP 2000-314875 A JP 2002-254573 A JP 2003-294951 A

  The anti-glare film used on the outermost surface of the display was required to have a function to suppress the reflection, but as the customer demand increased, the distance between the user and the display increased as in the case of a TV monitor. In an application for visually recognizing from a position, high visibility having high contrast is required while suppressing reflection. On the other hand, in applications such as notebook personal computers and desktop personal computers that are viewed from close positions, with the demand for higher resolution of the panel resolution, it is also required to reduce the phenomenon (glare) that the displayed image flickers. In recent years, there has been a demand for providing antifouling properties such as the ability to wipe off attached dirt such as fingerprints and sebum on the display surface, and there is also a demand for cost reduction by selecting a high value-added function.

  However, high anti-glare properties and contrast improvement are contradictory properties, and the surface irregularities are reduced to improve contrast, and when cleared, the anti-glare properties decrease because they do not scatter external light. It was difficult to achieve both.

  Specifically, the anti-glare film has an uneven structure on the surface of the anti-glare layer, thereby scattering the external light incident on the surface of the anti-glare film and blurring the image of the external light reflected on the surface of the anti-glare film. It is. When the anti-glare layer is composed of a binder matrix and particles, the irregularities on the surface of the anti-glare layer are the surface haze formed when the particles are single or agglomerate and protrude from the surface, and the internal due to scattering of transmitted light by the internal scattering particles Formed by haze.

  As a method for eliminating glare, a method of scattering transmitted light and suppressing a lens effect that causes glare, that is, a method of adding internal scattering particles has been used.

  However, increasing the surface haze and the internal haze increases the total haze, leading to a decrease in contrast. In anti-glare films, high anti-glare properties and improvement in contrast are in a trade-off relationship, making it difficult to achieve both.

  In addition, in conventional anti-glare films, dirt such as fingerprints and sebum adhering to the surface due to high anti-glare performance is not conspicuous, so high anti-stain properties are not required for anti-glare films. However, in a clear antiglare film for the purpose of improving contrast, the attached dirt tends to be noticeable, and both high contrast and sufficient dirt wiping properties are required.

  Furthermore, in conventional anti-glare films, anti-staining properties and anti-static properties were added for high value-added products, but adding anti-static functions leads to increased costs, so only necessary functions are provided. There is a demand for cost reduction by selecting and assigning.

  However, when antifouling property is imparted by a fluorine-containing compound having a polymerizable group, the fluorine has a charge, so that the surface potential becomes higher compared to a conventional antiglare film having no antistatic function, and the The antistatic function is necessary because the property is greatly impaired and causes problems, and the cost has not been reduced.

  Therefore, in the present invention, the antiglare film has (A) a high contrast, (B) a sufficient antiglare property, (C) a high antifouling property, and (D) a low charge. Therefore, the present invention provides an antiglare film that satisfies the requirement.

In order to solve the above-mentioned problems, the invention according to claim 1 is an antiglare film comprising a transparent substrate and an antiglare layer on one surface thereof, (a) JIS-K7105 of the antiglare film. -The total haze (Hz) specified in -1981 is in the range of 1.0% to 8.0%, and (b) the anti-glare layer has a contrast reduction rate of 3.0 under dark room conditions. (C) the water contact angle after alkali treatment of the antiglare layer is in the range of 90 degrees to 140 degrees,
An antiglare film characterized by satisfying all the numerical ranges defined in (a), (b), and (c), and having an absolute value of a frictional voltage of 1.0 kV or less. .

  The invention according to claim 2 is that the binder matrix of the antiglare layer forming coating liquid of the antiglare layer is an ionizing radiation curable acrylic material, and the antiglare layer forming coating liquid is The antiglare according to claim 1, wherein the particles contained in the binder matrix are methyl methacrylate, and the antiglare layer-forming coating liquid further contains a fluorine-containing compound having a polymerizable group. It is a film.

  The invention according to claim 3 is characterized in that the anti-glare layer according to claim 1 has an average film thickness defined by JIS-K5600-1999 of 4 μm or more and 10 μm or less. The antiglare film according to claim 1.

  The invention according to claim 4 is characterized in that the antiglare film according to any one of claims 1 to 3 and a first polarizing plate are provided on the antiglare layer-free surface of the antiglare film. It is an anti-glare polarizing plate.

  The invention according to claim 5 includes, in order from the observer side, the antiglare polarizing plate according to claim 4, a liquid crystal cell, a second polarizing plate, and a backlight unit in this order, and the antiglare A transmissive liquid crystal display in which a liquid crystal cell is held on the non-glare layer-free surface side of a polarizing plate.

  By setting it as the anti-glare film of the said structure, according to invention of Claim 1, the total haze (Hz) prescribed | regulated by JIS-K7105-1981 of an anti-glare film is 1.0% or more and 8.0%. The contrast reduction rate under the dark room conditions of the antiglare layer is 3.0% or less, and the water contact angle after the alkali treatment of the antiglare layer is 90 degrees or more and 140 degrees or less. Yes, and by making the absolute value of the frictional band voltage 1.0 kV or less, the antiglare film has (A) high contrast, (B) sufficient antiglare property, and (C) high antifouling. And (D) a small charge amount can be satisfied.

  In addition, by forming an antiglare layer with an ionizing radiation curable acrylic material applied on a transparent substrate, it can have sufficient crack resistance and pencil hardness when provided on the display surface, and methacrylic acid. The particles containing methyl have good compatibility with the binder matrix forming material, and the behavior of the particles in the binder matrix can be easily controlled. Furthermore, by containing at least a fluorine-containing compound having a polymerizable group in the antiglare layer, antifouling properties on the surface of the antiglare film can be provided.

  Moreover, since it can have sufficient crack resistance and pencil hardness and the degree of curling of the film can be suppressed, an antiglare film having an advantage that it is easy to handle even in the processing step can be obtained. Furthermore, the image displayed on the display is clear, and sufficient visibility of the image can be obtained even when used in an environment with external light or illumination.

  Therefore, the antiglare film according to the present invention can satisfy the high antifouling property and not to be charged while having high contrast and sufficient antiglare property. If the antiglare film is used, the effect of the invention can be achieved. A transmissive liquid crystal display having the above can be obtained.

It is a cross-sectional schematic diagram of the anti-glare film of one Example of this invention. It is a transmissive liquid crystal display using the anti-glare film of one Example of this invention. It is a schematic diagram of the die-coater coating device of one Example of this invention.

  The cross-sectional schematic diagram of the anti-glare film of this invention was shown in FIG.

  The antiglare film (1) of the present invention comprises an antiglare layer (12) on a transparent substrate (11). The antiglare layer (12) of the antiglare film (1) of the present invention comprises a binder matrix (120) and particles (121).

  The antiglare film of the present invention is formed by applying a coating liquid for forming an antiglare layer on a transparent substrate. The binder matrix forming material of the present invention is a solid of the coating liquid for forming an antiglare layer. This refers to the minute minus the particles.

  Therefore, the binder matrix forming material includes additives such as a photopolymerization initiator and a surface conditioner, a thermoplastic resin, and the like as required in addition to the acrylic material.

  In the antiglare film of the present invention, the antiglare film is provided with a transparent substrate and an antiglare layer on one surface thereof, and the total haze defined by JIS-K7105-1981 of the antiglare film. (Hz) is in the range of 1.0% to 8.0%, the contrast reduction rate of the antiglare layer under darkroom conditions is 3.0% or less, and the antiglare layer is polymerizable. A water contact angle after alkali treatment of the antiglare layer is 90 ° or more and 140 ° or less, and an absolute value of a frictional voltage is 1.0 kV or less. And

Moreover, the total haze (H _T ) defined by JIS-K7105-1981 of the antiglare film is in the range of 1.0% or more and 8.0% or less. In the case where the total haze (H _T ) of the antiglare film is less than 1.0%, the degree of unevenness is small, and it becomes impossible to sufficiently scatter outside light. In addition to being unable to provide an antiglare film, glare may occur when the obtained film is bonded to a high-definition display. On the other hand, when the total haze (H _T ) exceeds 8.0%, the contrast is lowered and the antiglare film has a strong white-brown feeling.

In addition, the total haze (H _T ) shown here is the sum of surface haze (H 2 _{O 2} ) caused by only the surface irregularities of the antiglare film and internal haze (H ₁ ) caused only by the inside of the antiglare layer. the value _(H O + H _I) is the total haze of the antiglare film _(H T) (or also referred to as a whole haze.) shows a.

  The internal haze of the antiglare layer is determined by measuring the antiglare film in a state where the irregularities on the surface of the antiglare layer are canceled using a transparent adhesive or the like according to JIS-K7105-1981. Can do.

  Further, the contrast reduction rate of the antiglare layer under dark room conditions is in the range of 3.0% or less. If the contrast reduction rate under dark room conditions of the antiglare layer is more than 3.0%, the antiglare film has a strong whitish feeling even within the total haze range. If the contrast reduction rate under dark room conditions of the antiglare layer is 3.0% or less, a film with a high contrast black display can be obtained.

  In addition, the reduction rate of contrast shows the reduction rate of the contrast of an anti-glare film from the value measured in the state without an anti-glare film.

  Further, the antiglare layer contains at least a fluorine-containing compound having a polymerizable group. In the anti-glare film, by adding a fluorine-containing compound having a polymerizable group to the anti-glare layer, the fluorine compound and the acrylic material forming the anti-glare layer can be bonded at the time of forming the anti-glare layer, Even if the surface of the antiglare layer is wiped with a cloth or the like a plurality of times, the antiglare layer can be maintained. In the case of a fluorine-containing compound having no polymerizable group, since the compound exists in a state of floating on the surface of the antiglare layer, it is removed from the surface by wiping with a cloth or the like. There is a drawback that it does not settle on the surface of the antiglare layer. Moreover, although a silicone type compound is also mentioned as a compound which provides high antifouling property, the same malfunction will arise also when a silicone type compound is added.

  Furthermore, the water contact angle of the antiglare layer after alkali treatment is in the range of 90 ° to 140 °. Even if the water contact angle before the alkali treatment is within the above range, if the water contact angle after the alkali treatment of the antiglare layer exceeds 90 degrees, it not only exhibits sufficient dirt wiping performance but also has poor durability. End up. In addition, in order to adhere it sufficiently when placing it on the outermost surface of the display by providing an adhesive layer on the surface opposite to the antiglare layer surface, or when using it as it is as a protective film for polarizing plates After the outermost layer is formed on the transparent substrate, saponification treatment may be performed, and durability by alkali treatment is required. When the water contact angle after alkali treatment of the antiglare layer exceeds 140 degrees, it has a high antifouling function without causing problems in the characteristics, but it is used as an antiglare film because the material is expensive. Not suitable for.

  The alkali treatment is performed by immersing the film in an alkali solution for an appropriate time. After being immersed in an alkaline solution, the film is sufficiently washed with water and dried so that no alkali component remains in the film.

  In addition, the absolute value of the frictional voltage is in the range of 1.0 kV or less. When the absolute value of the frictional voltage exceeds 1.0 kV, dust is likely to adhere due to static electricity, or static electricity is generated due to peeling electrification in the subsequent process of attaching a protective film or the like to the surface of the antiglare film. There is not. If the absolute value of the frictional voltage is in the range of 1.0 kV or less, there is no problem in practical use.

  Note that the frictional voltage is obtained by measuring the surface potential of static electricity generated by rubbing the surface of the antiglare film.

Further, in the antiglare film of the present invention, by using particles made of a copolymer of styrene and methyl methacrylate or particles made of methyl methacrylate, the compatibility with the binder matrix forming material is good and the dispersed state is achieved. There is no bias, the behavior of particles in the binder matrix can be easily controlled, and unevenness in appearance can be suppressed.
In particular, a homopolymer of methyl methacrylate or a copolymer of styrene and methyl methacrylate is preferable.

  Moreover, when forming the coating film of the antiglare layer, the average film thickness defined by JIS-K5600-1999 is preferably in the range of 4 μm or more and 10 μm or less. When the average film thickness of the antiglare layer is less than 4 μm, sufficient pencil hardness cannot be ensured. In addition, when the average film thickness of the antiglare layer exceeds 10 μm, in addition to high cost, the radius of curvature of the antiglare layer when the antiglare film is bent increases, so Since this force becomes large, it becomes impossible to obtain an antiglare film having sufficient crack resistance. In addition, since the curing shrinkage of the antiglare layer increases, the stress difference from the base material increases, and the degree of curling of the film cannot be suppressed, making it difficult to handle during the processing step. A problem such as breakage and bubble biting may occur due to the floating at the end of the material.

  The average film thickness (T) can be determined by an electronic micrometer or a fully automatic fine shape measuring instrument, and the particle diameter (R) of the particles can be measured by a light scattering particle size distribution measuring method.

  The antiglare film of the present invention is provided with a functional layer having antireflection performance, antistatic performance, electromagnetic wave shielding performance, infrared absorption performance, ultraviolet absorption performance, color correction performance, and the like as necessary. Examples of these functional layers include an antireflection layer, an antistatic layer, an electromagnetic wave shielding layer, an infrared absorption layer, an ultraviolet absorption layer, and a color correction layer. These functional layers may be a single layer or a plurality of layers. The functional layer may have a plurality of functions as a single layer, such as an antireflection layer having color correction performance. In addition, these functional layers may be provided between the transparent substrate and the antiglare layer, or may be provided on the antiglare layer. In the present invention, a primer layer, an adhesive layer, or the like may be provided between each layer in order to improve adhesion between various layers.

  FIG. 2 shows a transmissive liquid crystal display using the antiglare film of the present invention. In the transmissive liquid crystal display shown in FIG. 2A, an antiglare polarized light having an antiglare film (1) bonded to one surface and a first polarizing plate (2) on an antiglare layer-free surface. A plate (200), a liquid crystal cell (3), a second polarizing plate (4), and a backlight unit (5) are provided in this order. At this time, the antiglare film (1) side becomes the observation side, that is, the display surface.

  In Fig.2 (a), it is a transmissive | pervious liquid crystal display provided with the transparent base material (11) of an anti-glare film (1), and the transparent base material of a 1st polarizing plate (2) separately.

  The backlight unit (5) includes a light source and a light diffusing plate. The liquid crystal cell (3) has a structure in which an electrode is provided on one transparent substrate, an electrode and a color filter are provided on the other transparent substrate, and liquid crystal is sealed between both electrodes. In the first and second polarizing plates provided so as to sandwich the liquid crystal cell (3), the polarizing layer (23, 43) is sandwiched between the transparent base materials (21, 22, 41, 42). It has become.

  Moreover, in FIG.2 (b), the glare-proof film (1) provided with the glare-proof layer (12) on one surface of the transparent base material (11), and the glare-proof layer non-formation of the said glare-proof film A polarizing layer (23) and a transparent substrate (22) are sequentially provided on the surface to form an antiglare polarizing plate (210), and the antiglare polarizing plate (210), the liquid crystal cell (3), and the second A polarizing plate (4) and a backlight unit (5) are provided in this order. At this time, the antiglare layer (12) side of the antiglare film (1) is the observation side, that is, the display surface.

  In FIG.2 (b), the anti-glare polarization | polarized-light provided with the polarizing layer (23) and the transparent base material (22) in this order as a 1st polarizing plate in the anti-glare layer non-formation surface of an anti-glare film. It is a transmissive liquid crystal display provided with a plate (210).

  Similar to FIG. 2A, the backlight unit (5) includes a light source and a light diffusion plate. The liquid crystal cell has a structure in which an electrode is provided on one transparent substrate, an electrode and a color filter are provided on the other transparent substrate, and liquid crystal is sealed between both electrodes. In the first and second polarizing plates provided so as to sandwich the liquid crystal cell (3), the polarizing layer (23, 43) is sandwiched between the transparent base materials (11, 22, 41, 42) and It has become.

  Moreover, in the transmissive liquid crystal display of this invention, you may provide another functional member. Other functional members include, for example, a diffusion film, a prism sheet, a brightness enhancement film for effectively using light emitted from a backlight, and a phase difference film for compensating for a phase difference between a liquid crystal cell and a polarizing plate. However, the transmissive liquid crystal display of the present invention is not limited to these.

  Next, it shows about the manufacturing method of the anti-glare film of this invention.

  In the method for producing an antiglare film of the present invention, a coating solution for forming an antiglare layer containing at least a binder matrix-forming material and particles that are cured by ionizing radiation is applied onto a transparent substrate, and then applied onto the transparent substrate. The antiglare layer can be formed on the transparent substrate by providing a film forming step and a curing step of curing the binder matrix forming material with ionizing radiation.

  An ionizing radiation curable acrylic material can be used as the binder matrix forming material. Examples of ionizing radiation curable acrylic materials include monofunctional or polyfunctional (meth) acrylate compounds such as polyhydric alcohol acrylic acid or methacrylic acid ester, diisocyanate and polyhydric alcohol, and acrylic acid or methacrylic acid hydroxy ester, etc. A polyfunctional urethane (meth) acrylate compound as synthesized from the above can be used. Besides these, polyether resins having an acrylate functional group, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and the like can be used.

  In the present invention, “(meth) acrylate” refers to both “acrylate” and “methacrylate”. For example, “urethane (meth) acrylate” indicates both “urethane acrylate” and “urethane methacrylate”.

  Examples of the monofunctional (meth) acrylate compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl ( (Meth) acrylate, t-butyl (meth) acrylate, glycidyl (meth) acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofurfuryl acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) ) Acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, benzyl (Meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phosphoric acid (meth) acrylate, ethylene oxide modified phosphoric acid (meth) acrylate, phenoxy (meta) ) Acrylate, ethylene oxide modified phenoxy (meth) acrylate, propylene oxide modified phenoxy (meth) acrylate, nonylphenol (meth) acrylate, ethylene oxide modified nonylphenol (meth) acrylate, propylene oxide modified nonylphenol (meth) acrylate, methoxydiethylene glycol (meth) Acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) acryloyloxyethyl hydrogen phthalate, 2- (meth) acryloyloxypropyl hydrogen Phthalate, 2- (meth) acryloyloxypropyl hexahydrohydrogen phthalate, 2- (meth) acryloyloxypropyl tetrahydrohydrogen phthalate, dimethylaminoethyl (meth) acrylate, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate , Hexafluoropropyl (meth) acrylate, octafluoropropyl (meth) acrylate, octafluoropropyl (meth) acrylate, 2 -Adamantane derivatives mono (meth) acrylates such as adamantyl acrylate having a monovalent mono (meth) acrylate derived from adamantane and adamantanediol.

  Examples of the bifunctional (meth) acrylate compound include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di (meth) acrylate, and nonanediol di (meth). ) Acrylate, ethoxylated hexanediol di (meth) acrylate, propoxylated hexanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (Meth) acrylate, neopentyl glycol di (meth) acrylate, ethoxylated neopentyl glycol di (meth) acrylate, tripropylene glycol Ruji (meth) acrylate, di (meth) acrylate, such as hydroxypivalic acid neopentyl glycol di (meth) acrylate.

  Examples of the trifunctional or higher functional (meth) acrylate compound include trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, and tris 2-hydroxy. Ethyl isocyanurate tri (meth) acrylate, tri (meth) acrylate such as glycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, etc. Trifunctional (meth) acrylate compounds, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol te Trifunctional or higher polyfunctionality such as la (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane hexa (meth) acrylate ( Examples thereof include a (meth) acrylate compound and a polyfunctional (meth) acrylate compound obtained by substituting a part of these (meth) acrylates with an alkyl group or ε-caprolactone.

  Moreover, as a urethane (meth) acrylate compound, the compound obtained by making a polyhydric alcohol, a polyvalent isocyanate, and a hydroxyl-containing acrylate react can be used, Specifically, Kyoeisha Chemical Co., Ltd. make, UA-306H. , UA-306T, UA-306I, etc., manufactured by Nippon Synthetic Chemical Co., Ltd., UV-1700B, UV-6300B, UV-7600B, UV-7605B, UV-7640B, UV-7650B, etc., Shin-Nakamura Chemical Co., Ltd., U-4HA U-6HA, UA-100H, U-6LPA, U-15HA, UA-32P, U-324A, etc., manufactured by Daicel UCB, Ebecryl-1290, Ebecryl-1290K, Ebecryl-5129, etc., manufactured by Negami Industrial Co., Ltd. UN-3220HA, UN-3220HB, UN-322 HC, it can be used UN-3220HS like.

  As the binder matrix forming material, a thermoplastic resin or the like can be added in addition to the ionizing radiation curable acrylic material. Examples of the thermoplastic resin include cellulose derivatives such as acetylcellulose, nitrocellulose, acetylbutylcellulose, ethylcellulose, and methylcellulose, vinyl acetate and copolymers thereof, vinyl chloride and copolymers thereof, vinylidene chloride and copolymers thereof, and the like. Acetal resins such as acrylic resins, polyvinyl formal, polyvinyl butyral, acrylic resins and copolymers thereof, acrylic resins such as methacrylic resins and copolymers thereof, polystyrene resins, polyamide resins, linear polyester resins, polycarbonate resins, etc. it can. By adding a thermoplastic resin, the adhesion between the transparent substrate and the antiglare layer can be improved. Moreover, the curling of the anti-glare film manufactured can be suppressed by adding a thermoplastic resin.

  Moreover, when using an ultraviolet-ray as ionizing radiation, a photoinitiator is added to the coating liquid for anti-glare layer formation. Although a well-known photoinitiator can be used for a photoinitiator, it is preferable to use what was suitable for the binder matrix formation material to be used. As the photopolymerization initiator, benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl methyl ketal, and alkyl ethers thereof are used. The usage-amount of a photoinitiator is 0.5 weight part-20 weight part with respect to binder matrix formation material. The amount is preferably 1 part by weight to 5 parts by weight.

  The particles used in the present invention include acrylic particles (refractive index 1.49), acrylic / styrene particles (refractive index 1.49 to 1.59), polystyrene particles (refractive index 1.59), polycarbonate particles (refractive index). 1.58), melamine particles (refractive index 1.66), epoxy particles (refractive index 1.58), polyurethane particles (refractive index 1.55), nylon particles (refractive index 1.50), polyethylene particles (1. 50 to 1.56), polypropylene particles (refractive index 1.49), silicone particles (refractive index 1.43), polytetrafluoroethylene particles (refractive index 1.35), polyvinylidene fluoride particles (refractive index 1.42). ), Polyvinyl chloride particles (refractive index 1.54), polyvinylidene chloride particles (refractive index 1.62), glass particles (refractive index 1.48), silica (refractive index 1.43), etc. It can be used. In the present invention, the particles may be a plurality of types of particles.

  As the transparent substrate used in the present invention, glass, plastic film or the like can be used. The plastic film only needs to have appropriate transparency and mechanical strength. For example, polyethylene terephthalate (PET), triacetyl cellulose (TAC), diacetyl cellulose, acetyl cellulose butyrate, polyethylene naphthalate (PEN), cycloolefin polymer, polyimide, polyethersulfone (PES), polymethyl methacrylate (PMMA), A film such as polycarbonate (PC) can be used. Among them, a triacetyl cellulose film can be suitably used because it has little birefringence and good transparency. In particular, when the antiglare film of the present invention is provided on the surface of a liquid crystal display, as a transparent substrate. Triacetyl cellulose (thickness 35 μm to 80 μm) is preferably used.

  Further, as shown in FIG. 2B, it is also possible to provide a polarizing layer on the surface opposite to the surface on which the antiglare layer of the transparent substrate is provided. At this time, as a polarizing layer, what consists of extended polyvinyl alcohol (PVA) which added the iodine can be illustrated. At this time, the polarizing layer is held between transparent substrates.

  A solvent is added to the coating solution for forming the antiglare layer as necessary. By adding a solvent, it is possible to uniformly disperse the particles and the binder matrix, and to adjust the viscosity of the coating liquid to an appropriate range when coating the antiglare layer forming coating liquid on the transparent substrate. Become.

  In the present invention, when triacetyl cellulose is used as a transparent substrate and an anti-glare layer is provided directly on the triacetyl cellulose film without any other functional layer, tri-cellulose is used as a solvent for the anti-glare layer forming coating solution. It is preferable to use a mixed solvent of a solvent that dissolves or swells the acetylcellulose film and a solvent that does not dissolve or swell the triacetylcellulose film. By using the mixed solvent, sufficient adhesion is obtained at the interface between the triacetylcellulose film and the antiglare layer. It can be set as the anti-glare film which has.

  At this time, as a solvent for dissolving or swelling the triacetyl cellulose film, ethers such as dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, dioxane, dioxolane, trioxane, tetrahydrofuran, anisole and phenetole, and acetone are used. , Methyl ketones such as methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, and ethylcyclohexanone, as well as ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate , Esters such as methyl propionate, ethyl propionate, n-pentyl acetate, and γ-ptyrolactone, and methyl cellosolve, Cellosolve, butyl cellosolve, cellosolve such as cellosolve acetate. These can be used alone or in combination of two or more.

  Solvents that do not dissolve or swell the triacetyl cellulose film include aromatic hydrocarbons such as toluene, xylene, cyclohexane and cyclohexylbenzene, hydrocarbons such as n-hexane, methyl isobutyl ketone, methyl butyl ketone and the like. Examples include ketones. These can be used alone or in combination of two or more.

  In the present invention, a fluorine-containing compound having a polymerizable group is added so that the water contact angle of the antiglare layer after alkali treatment is in the range of 90 ° to 140 °. Examples of the fluorine-containing compound having a polymerizable group include a fluoroalkyl group (perfluoroalkyl group) in which part or all of the hydrogen atoms of an alkyl group are substituted with fluorine atoms, and a carbon-carbon unsaturated divalent compound. A compound having a heavy bond can be exemplified.

  As such a fluorine-containing compound having a polymerizable group of the present invention, OPTOOL DAC (manufactured by Daikin Industries, Ltd.), SUA1900L10, SUA1900L6 (manufactured by Shin-Nakamura Chemical Co., Ltd.), UT3971 (manufactured by Nippon Gosei Co., Ltd.) Defencer TF3001, Defencer TF3000, Defencer TF3028 (Dainippon Ink Co., Ltd.), Light Procoat AFC3000 (Kyoeisha Chemical Co., Ltd.), KNS5300 (Shin-Etsu Silicone Co., Ltd.), UVHC1105, UVHC8550 (GE Toshiba Silicone ( However, it is not limited to this as long as it has an effect of setting the water contact angle of the antiglare layer after alkali treatment to a range of 90 ° to 140 °.

  In the present invention, in order to prevent the occurrence of coating film defects such as repellency and unevenness in the antiglare layer (coating film) to be applied and formed, an additive called a surface conditioner is added to the coating liquid for forming the antiglare layer. May be added. Surface modifiers are also called leveling agents, antifoaming agents, interfacial tension modifiers, and surface tension modifiers, depending on their function, all of which reduce the surface tension of the coating film (antiglare layer) that is formed. Is provided.

  Moreover, in the coating liquid for anti-glare layer formation of this invention, you may add another additive other than the surface regulator mentioned above in the coating liquid. However, it is preferable that these additives do not affect the transparency and light diffusibility of the antiglare layer to be formed.

  As a functional additive, an antistatic agent, an ultraviolet absorber, an infrared absorber, a refractive index adjuster, an adhesion improver, a curing agent, and the like can be used. Functions other than the anti-glare function such as an ultraviolet absorption function and an infrared absorption function can be provided.

  The antiglare layer-forming coating solution is applied onto a transparent substrate to form a coating film. For example, as a coating method for applying a coating solution for forming an antiglare layer on a transparent substrate, a coating method using a roll coater, a reverse roll coater, a gravure coater, a knife coater, a bar coater, or a die coater. Can be used. Among them, it is preferable to use a die coater that can be applied at a high speed by a roll-to-roll method. The solid content concentration of the coating liquid varies depending on the coating method. Solid content concentration should just be about 30 to 70 weight% by weight ratio.

  Next, the die coater coating apparatus of the present invention will be described. FIG. 3 shows a schematic diagram of the die coater coating apparatus of the present invention. In the die coater coating apparatus of the present invention, a die head (30) and a coating liquid tank (32) are connected by a pipe (31), and a coating for forming an antiglare layer in the coating liquid tank (32) is performed by a liquid feed pump (33). The liquid is sent into the die head (30). The antiglare layer forming coating solution fed to the die head (30) discharges the coating solution from the slit gap, and a coating film is formed on the transparent substrate (11). By using the roll type transparent substrate (11) and the rotating roll (35), a coating film can be continuously formed on the transparent substrate by a roll-to-roll method.

  An antiglare layer is formed by irradiating the coating film obtained by applying the coating liquid on the transparent substrate with ionizing radiation. As the ionizing radiation, ultraviolet rays and electron beams can be used. In the case of ultraviolet curing, a light source such as a high pressure mercury lamp, a low pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a carbon arc, or a xenon arc can be used. In the case of electron beam curing, electron beams emitted from various electron beam accelerators such as cockloftwald type, bandegraph type, resonant transformer type, insulated core transformer type, linear type, dynamitron type, and high frequency type can be used. . The electron beam preferably has an energy of 50 to 1000 KeV. An electron beam having an energy of 100 to 300 KeV is more preferable.

  In addition, you may provide a drying process before and after the process of forming an anti-glare layer by hardening. Moreover, you may perform hardening and drying simultaneously. In particular, when the coating liquid contains a binder matrix material, particles, and a solvent, it is necessary to provide a drying step before irradiation with ionizing radiation in order to remove the solvent of the formed coating film. Examples of the drying means include heating, air blowing, and hot air.

  As described above, the antiglare film of the present invention is produced.

  Examples are shown below.

Example 1
A triacetyl cellulose film (TD-80U manufactured by Fuji Photo Film) was used as a transparent substrate. As a binder matrix forming material, pentaerythritol triacrylate (94.5 parts by weight, refractive index 1.48) which is an acrylic material, and Irgacure 184 (manufactured by Ciba Japan) (5 parts by weight) which is a photopolymerization initiator, An OPTOOL DAC (manufactured by Daikin Industries) (0.4 parts by weight), which is a fluorine-containing compound having a polymerizable group, was prepared. Further, particles containing methyl methacrylate having a refractive index of 1.53 were prepared as particles, and the total amount was 100 parts by weight.

  Further, toluene (70 parts by weight) and dioxolane (30 parts by weight) were prepared as solvents, and a binder matrix forming material, particles, and a solvent were mixed to obtain a coating solution for forming an antiglare layer.

And the anti-glare layer coating liquid was apply | coated on the triacetyl cellulose using the die-coater coating device, and the coating film was obtained. By drying the resulting coating film to remove the solvent contained in the coating film, and then irradiating it with ultraviolet light at 400 mJ / cm ^{2 in} an atmosphere having an oxygen concentration of 0.03% or less using a high pressure mercury lamp. The coating film was cured to produce an antiglare film having an antiglare layer on a transparent substrate. The average film thickness (H) of the obtained antiglare layer was 5.8 μm.

Particle refractive index (n _A ) of (Example 1): 1.53, average film thickness (T) of antiglare layer: 5.8 μm, particle content (parts by weight): 5 parts by weight, particle diameter: 5. 0 μm, fluorine-containing compound content: 0.4 parts by weight based on the average film thickness (T), particle refractive index (n _A ), particle content (parts by weight), particle diameter (R) of each antiglare layer The antiglare films of (Example 1) to (Example 6) and (Comparative Example 1) to (Comparative Example 3) were prepared by changing the value of the fluorine-containing compound content (parts by weight). In (Comparative Example 2), a fluorine-containing additive having no polymerizable group: F470 (manufactured by DIC) was used as the fluorine-containing compound. Specific contents will be described below.

  (Example 2) is an example in which the antiglare layer of (Example 1) is changed to an average film thickness (T): 8.0 μm.

  (Example 3) is an example in which the antiglare layer of (Example 1) is changed to an average film thickness (T): 4.9 μm.

(Example 4) is the antiglare layer of (Example 1), with an average film thickness (T): 6.4 μm, a particle diameter (R): 4.0 μm, and a particle refractive index (n _A ): 1. 53, Particle content (parts by weight): This is an example in which the content is changed to 3.0 parts by weight.

  (Example 5) is an example in which the antiglare layer of (Example 1) is changed to fluorine-containing compound content (parts by weight): 0.6 parts by weight.

  (Example 6) is an example in which the antiglare layer of (Example 1) is changed to fluorine-containing compound content (parts by weight): 0.2 parts by weight.

(Comparative Example 1) is the antiglare layer of (Example 1), with an average film thickness (T): 5.9 μm, a particle diameter (R): 4.0 μm, and a particle refractive index (n _A ): 1. This is an example of changing to 54.

  (Comparative Example 2) changed the antiglare layer of (Example 1) to an average film thickness (T): 5.7 μm and a fluorine-containing additive having no polymerizable group as a fluorine-containing compound: F470. It is an example.

  (Comparative Example 3) is an example in which the antiglare layer of (Example 1) was changed to fluorine-containing compound content (parts by weight): 1.0 part by weight.

  Unless otherwise specified, the operation in (Example 1) is assumed.

  In (Example 2) to (Example 6) and (Comparative Example 1) to (Comparative Example 3), binder matrix forming materials (acrylic material, photopolymerization initiator, fluorine-containing compound), solvent Is applied using the same material as in (Example 1) by the same die coater coating apparatus as in (Example 1). Moreover, the antiglare film was produced on the same conditions as (Example 1) as drying conditions and ultraviolet irradiation conditions.

  (Table 1) shows antiglare layer-forming coating solutions used in the preparation of antiglare layers of (Example 1) to (Example 6) and (Comparative Example 1) to (Comparative Example 3).

About the anti-glare films obtained in (Example 1) to (Comparative Example 6) and (Comparative Example 1) to (Comparative Example 3), “average film thickness (T)”, “particle refractive index (n _A )”. It was subjected to measurement of (binder matrix _(n M)), "" particle size (R) ". Each measurement method is shown below.

"Average film thickness (T)"
Using an electronic micrometer (Anritsu K351C), according to JIS-K5600-1999, the local thickness (t) of the specified portion uniformly distributed over the entire effective surface area is measured, and the average thickness is averaged. Thickness (T). The effective surface area was 0.1 m square, and the specified number of locations was 10.

“Refractive index of particles (n _A ) (binder matrix (n _M ))”
There are the following three methods for measuring the refractive index of the fine particles, and any one of the methods is applied depending on the characteristics of the fine particles.

  The first method is an extrapolation method that utilizes the fact that fine particles dissolve in a solvent. The refractive index of particles is extrapolated from the concentration of the dissolved particles and their refractive index. Looking for. This method has the premise that the particles must be dissolved in the solution.

  The second method is the Becke line method, in which fine particles are set on the slide, the dispersion is dropped, and the Becke lines generated inside and outside the edges of the fine particles are visually observed with a microscope. . At this time, the lens barrel is moved up and down, and the refractive index of the dispersion is adjusted until the Becke line is confirmed, and this is obtained from the refractive index of the dispersion. When the particles are very small, it is difficult to confirm the Becke line.

  The third method is the so-called immersion method, which is very similar to the Becke's line method, where the refractive index of the dispersion is changed, light is irradiated, and the scattered light from the fine particles in the dispersion is visually observed. The refractive index when it becomes invisible due to is the refractive index of the fine particles. However, since the immersion method observes changes in scattered light by visual observation, a subjective factor is inevitably introduced.

The refractive index (n _A ) of the particles of the present invention was measured by a liquid immersion method which is a third method.

The refractive index (n _M ) of the binder matrix was measured by a Becke line detection method (immersion method) using a binder matrix-forming material excluding particles and a coating liquid composed of a solvent, dried and UV-cured.

“Particle size (R)”
The particle diameter (R) of the particles was measured by a light scattering particle size distribution measurement method.

  Specifically, there is a light scattering / diffraction method in one group of particle diameter measurement methods, and the light scattering particle size distribution measurement method is one of the particle size and particle size distribution measurement methods. The scattering phenomenon that occurs when light strikes a minute particle floating inside changes depending on the particle size, refractive index, wavelength of incident light, etc., but the relationship between the particle size and the amount of scattered light is known. The particle size distribution can be obtained by measuring the amount of scattered light and the number of occurrences. This is a method for specifying the central particle size from the obtained particle size distribution. In addition, although not used in the present invention, the particle diameter can be measured by several methods based on JIS-Z8901.

In Table 1, “average film thickness (T)”, “particle refractive index (n _A ) (binder matrix (n _M ))” and “particle diameter (R) of the antiglare films obtained in Examples and Comparative Examples are shown. ) "Is shown.

  In addition, for the antiglare films obtained in (Example 1) to (Comparative Example 6) and (Comparative Example 1) to (Comparative Example 3), (1) total haze (2) contrast, (3) Friction voltage, (4) Water contact angle, (5) were evaluated. Each evaluation method is shown below.

"Total Haze"
The haze was measured according to JIS-K7105-1981 using a haze meter (NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.).

"contrast"
An anti-glare film is attached to a liquid crystal monitor (BUFFLO FTD-W2023ADSR) via an adhesive, and the luminance (white luminance) when displaying white on the liquid crystal monitor using a luminance meter (LS-100, manufactured by Konica Minolta), black The luminance at the time of display (black luminance) was measured, and the value obtained by dividing the white luminance by the black luminance was taken as the contrast. The measurement was performed under dark room conditions. At this time, the value measured for the antiglare film in the absence of the antiglare film was taken as 100%, and the reduced ratio was taken as the reduction rate.

"Friction band voltage"
Affixed to a black plastic plate with an adhesive and wiped the surface of the antiglare layer 3 times with Ben Cotton (Ben Cotton M-3 manufactured by Asahi Kasei Co., Ltd.) under an environment of 25 ° C.-50%. The charge amount was measured with a digital electrostatic potential measuring device (KSD-0103 manufactured by Kasuga Electric Co., Ltd.).

"Water contact angle"
Using a contact angle meter (CA-X type manufactured by Kyowa Interface Chemical Co., Ltd.), a droplet having a diameter of 1.8 mm is formed on the needle tip in a dry state (20 ° C.-65% RH), and this is formed on the surface of the antiglare layer. Drops were made in contact with. The contact angle is an angle formed by a tangent to the liquid surface at a point where the solid and the liquid are in contact with the solid surface, and is defined as an angle on the side including the liquid. Distilled water was used as the liquid.

  The water contact angle was measured after alkali-treating the antiglare film. The alkali treatment is performed by immersing in a 1.5N sodium hydroxide aqueous solution heated to 50 ° C. for 2 minutes. After being immersed in the alkaline solution, the film is sufficiently washed with water and sufficiently dried so that no alkali component remains in the film.

  Table 2 shows the evaluation results of “total haze”, “contrast”, “friction band voltage”, and “water contact angle” of the antiglare films obtained in Examples and Comparative Examples.

  Therefore, in (Example 1) to (Example 6), compared with the anti-glare films of (Comparative Example 1) to (Comparative Example 3), (A) has a high contrast, (B) It was possible to obtain an antiglare film having sufficient antiglare properties, (C) having high antifouling properties, and (D) having a small charge amount. Furthermore, in (Example 1), it was able to be set as the anti-glare film provided with the high anti-glare property which can satisfy | fill all the items.

DESCRIPTION OF SYMBOLS 1 Anti-glare film 11 Transparent base material 12 Anti-glare layer 120 Binder matrix 121 Particles T Average thickness of anti-glare layer 2 First polarizing plate 21 Transparent base material 22 Transparent base material 23 Polarizing layer 200 Anti-glare polarizing plate 210 Anti-glare Dazzling polarizing plate 3 Liquid crystal cell 30 Die head 31 Piping 32 Coating liquid tank 33 Liquid feed pump 35 Rotating roll 4 Second polarizing plate 41 Transparent base material 42 Transparent base material 43 Polarizing layer 5 Backlight unit

Claims (5)

A transparent substrate and an antiglare film comprising an antiglare layer on one surface thereof,
(A) The total haze (Hz) prescribed | regulated by JIS-K7105-1981 of the said anti-glare film exists in the range of 1.0% or more and 8.0% or less, and
(B) The antiglare layer has a contrast reduction rate of 3.0% or less under dark room conditions,
(C) The water contact angle after alkali treatment of the antiglare layer is in the range of 90 degrees to 140 degrees,
Satisfy all the numerical ranges defined in (a), (b) and (c),
The antiglare film is characterized in that the absolute value of the frictional voltage is 1.0 kV or less. The binder matrix of the antiglare layer forming coating liquid of the antiglare layer is an ionizing radiation curable acrylic material, and the particles contained in the binder matrix of the antiglare layer forming coating liquid are methyl methacrylate. Yes,
The antiglare film according to claim 1, further comprising a fluorine-containing compound having a polymerizable group in the antiglare layer-forming coating solution.   3. An antiglare film, wherein the antiglare layer according to claim 1 has an average film thickness defined by JIS-K5600-1999 of 4 μm or more and 10 μm or less.   An anti-glare polarizing plate comprising the anti-glare film according to any one of claims 1 to 3 and a first polarizing plate on an anti-glare layer-free surface of the anti-glare film.   The anti-glare polarizing plate according to claim 4, a liquid crystal cell, a second polarizing plate, and a backlight unit are provided in this order from the observer side, and the anti-glare layer non-forming surface side of the anti-glare polarizing plate A transmissive liquid crystal display characterized by holding a liquid crystal cell.