JP5120490B2 - Antiglare film, method for producing antiglare film, polarizing plate and image display device - Google Patents

Description

The present invention relates to an antiglare film, a method for producing the antiglare film, a polarizing plate, and an image display device.

In an image display device such as a cathode ray tube display device (CRT), a liquid crystal display (LCD), a plasma display (PDP), and an electroluminescence display (ELD), an optical laminate for preventing reflection is generally provided on the outermost surface. ing. Such an anti-reflection optical laminate suppresses the reflection of an image or reduces the reflectance due to light scattering or interference.

As one of the antireflection optical laminates, an antiglare film is known in which an antiglare layer having an uneven shape is formed on the surface of a transparent substrate. This antiglare film can prevent external light from being scattered due to the uneven shape of the surface, thereby preventing a decrease in visibility due to reflection of external light or reflection of an image.

As a conventional anti-glare film, for example, a film in which an anti-glare layer is formed by coating a resin containing a filler such as silicon dioxide (silica) on the surface of a transparent substrate film is known (for example, (See Patent Documents 1 and 2).
These antiglare films are a type that forms an uneven shape on the surface of the antiglare layer by agglomeration of particles such as cohesive silica, and an organic filler having a particle size larger than the film thickness of the coating film is added to the resin. There is a type in which a concavo-convex shape is formed on the layer surface, or a type in which a concavo-convex shape is transferred by laminating a film having a concavo-convex shape on the layer surface.

Such a conventional anti-glare film is designed to obtain a light diffusing and anti-glare action by the action of the surface shape of the anti-glare layer. Although it is necessary to make it large, there is a problem that when the unevenness becomes large, the haze value (haze value) of the coating film increases and white brown is generated, and the transmission sharpness decreases accordingly.
Further, the conventional type anti-glare film has a problem that a sparkle of so-called surface glare (scintillation) is generated on the film surface and the visibility of the display screen is lowered.

By the way, in recent years, higher definition of liquid crystal displays has been promoted. However, when a conventional antiglare film is applied to a high definition liquid crystal display, the occurrence of scintillation has become a more serious problem.
In addition, as the binder resin constituting the antiglare layer, a resin obtained by curing an ultraviolet curable binder resin by ultraviolet irradiation is used, but such an antiglare layer is hard but weak against impact. there were.
In the polarizing plate manufacturing process and the laminating process between the polarizing plate and the liquid crystal element, the radius of curvature of the antiglare film may be reduced or a local load may be applied. When an anti-glare film provided with an anti-glare layer is used, there is a problem that cracks occur in the anti-glare layer. Furthermore, liquid crystal displays are required to have high scratch resistance. However, since scratches are triggered by the occurrence of local microcracks caused by weighting, antiglare films have crack resistance, that is, impact resistance. It was required to have.
Furthermore, the antiglare film produced by polymerization shrinkage of the ultraviolet curable resin has a problem that curling may occur.

For example, Patent Document 3 describes an antiglare material obtained by mixing resin beads swollen 70% or more with a solvent into a binder resin.
Anti-glare film with anti-glare layer using resin beads swollen in advance with such a solvent can be expected to improve the adhesion at the interface between resin beads and binder resin. Therefore, it is expected to be applied to high definition displays.
However, the anti-glare film provided with the anti-glare layer using resin beads swollen with a solvent in advance is improved in adhesion at the interface between the swollen resin beads and the binder resin in the anti-glare layer. Therefore, there was room for further improvement in adhesion and the like.
For this reason, the conventional anti-glare film is insufficient as the impact resistance of the entire anti-glare layer, and cracks occur in the anti-glare layer when applied to the above-mentioned polarizing plate manufacturing process or a liquid crystal display. Was not able to be sufficiently prevented.

JP-A-6-18706 Japanese Patent Laid-Open No. 10-20103 JP 2005-281476 A

In view of the above-described situation, the present invention has an anti-glare film that has excellent impact resistance and can suitably suppress the occurrence of cracks, a method for producing the anti-glare film, and a polarizing plate to which the anti-glare film is applied. An object of the present invention is to provide an image display device.

The present invention is an antiglare film comprising a light-transmitting substrate and a diffusion layer formed on at least one surface of the light-transmitting substrate and having a concavo-convex shape on the surface. A coating solution containing a layered inorganic compound, organic fine particles (A), and a (meth) acrylate monomer as an essential component, and a surfactant, and at least one of the above light-transmitting substrates It is formed by coating and drying on the surface to form a coating film, and then curing the coating film. The layered inorganic compound is randomly oriented in the diffusion layer that is not oriented by convection of the coating liquid. It is contained in a state and has an average particle size of 0.3 to 5 μm.

In the antiglare film of the present invention, the layered inorganic compound is preferably talc.
Moreover, it is preferable that the said coating liquid contains the solvent which swells organic fine particles (A).
The coating liquid further contains fine particles (B), the organic fine particles (A) in the diffusion layer have an impregnation layer impregnated with a radiation curable binder, and the fine particles ( It is preferable to have an average particle size larger than the average particle size of B).
The fine particles (B) are preferably fine particles having higher lipophilicity than the organic fine particles (A).
Further, when the difference between the refractive index of the radiation curable binder and the refractive index of the organic fine particles (A) and the fine particles (B) is Δ _A and Δ _B , respectively, the Δ _A and Δ _B are expressed by the following formulas: It is preferable to satisfy (1).
| Δ _A | <| Δ _B | (1)

The present invention also provides a method for producing an antiglare film comprising a light transmissive substrate and a diffusion layer formed on at least one surface of the light transmissive substrate and having a concavo-convex shape on the surface. A radiation curable binder containing a layered inorganic compound, organic fine particles (A), and a (meth) acrylate monomer, and a surfactant as essential components is contained on at least one surface of the light-transmitting substrate. The coating liquid is applied and dried to form a coating film, and the coating film is cured to form the diffusion layer. The layered inorganic compound in the diffusion layer is formed by convection of the coating liquid. It is contained in the random orientation state which is not oriented, and it is also the manufacturing method of the anti-glare film characterized by the average particle diameter being 0.3-5 micrometers.

Moreover, this invention is a polarizing plate provided with a polarizing element, Comprising: The anti-glare film of this invention is provided on the surface of the said polarizing element, It is also a polarizing plate characterized by the above-mentioned.
Moreover, this invention is also an image display apparatus provided with the optical laminated body of this invention, or the polarizing plate of this invention in the outermost surface.
Hereinafter, the present invention will be described in detail.

The antiglare film of the present invention has a light-transmitting substrate and a diffusion layer formed on at least one surface of the light-transmitting substrate and having an uneven shape on the surface.
The light transmissive substrate preferably has smoothness and heat resistance and is excellent in mechanical strength. Specific examples of the material forming the light-transmitting substrate include polyester (polyethylene terephthalate, polyethylene naphthalate), cellulose triacetate, cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyethersulfone, polysulfone, and polypropylene. , Thermoplastic resins such as polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate or polyurethane, preferably polyester (polyethylene terephthalate, polyethylene naphthalate), cellulose triacetate Can be mentioned.

As the light transmissive substrate, an amorphous olefin polymer (Cyclo-Olefin-Polymer: COP) film having an alicyclic structure can also be used. This is a base material in which a norbornene polymer, a monocyclic olefin polymer, a cyclic conjugated diene polymer, a vinyl alicyclic hydrocarbon polymer resin, or the like is used. ZEONEX and ZEONOR (norbornene resin) manufactured by Sumitomo Bakelite Co., Ltd., Sumilite FS-1700 manufactured by Sumitomo Bakelite Co., Ltd., Arton (modified norbornene resin) manufactured by JSR Co., Ltd. Copolymer), Topas (cyclic olefin copolymer) manufactured by Ticona, Optretz OZ-1000 series (alicyclic acrylic resin) manufactured by Hitachi Chemical Co., Ltd., and the like. Further, the FV series (low birefringence, low photoelastic modulus film) manufactured by Asahi Kasei Chemicals Corporation is also preferable as an alternative base material for triacetylcellulose.

The light-transmitting substrate is preferably used as a film-like body rich in flexibility of the thermoplastic resin, but these thermoplastic resin plates are used depending on the use mode in which curability is required. It is also possible, or a glass plate plate may be used.

The thickness of the light transmissive substrate is preferably 20 to 300 μm, more preferably an upper limit of 200 μm and a lower limit of 30 μm. When the light-transmitting substrate is a plate-like body, the thickness may exceed these thicknesses.
In addition, the above light-transmitting base material is a coating called an anchor agent or primer in addition to physical treatment such as corona discharge treatment and oxidation treatment for improving adhesion when forming an antiglare layer thereon. Application may be performed in advance.

In the antiglare film of the present invention, the diffusion layer is formed by applying a coating liquid containing a layered inorganic compound, organic fine particles (A), and a radiation curable binder containing (meth) acrylate monomers as essential components to the light transmitting material. It is formed by applying and drying on at least one surface of a conductive substrate to form a coating film and curing the coating film.
The layered inorganic compound is not particularly limited. Examples include margarite, muscovite, phlogopite, tetrasilic mica, teniolite, antigolite, chlorite, cookite, and nanthite. These layered inorganic compounds may be natural products or synthetic products. The layered inorganic compound may be subjected to an organic surface treatment.
The particle diameter of these layered inorganic compounds is indicated by an average particle diameter D50 (median diameter of particle diameter distribution) measured by a laser diffraction / scattering particle size distribution measurement method. A preferred particle size range is 0.1 to 9 μm, more preferably 0.3 to 5 μm.
These layered inorganic compounds are present as plate-like particles of about 0.3 to 5 μm when the cross section of an actual antiglare film is observed with an SEM or the like. In order to solve the problem of the present invention, even if the particle diameter is too small, the effect cannot be exhibited, and if it is too large, the transparency of the entire antiglare film may be affected. It is a particle size that can be measured as a result of cross-sectional observation with SEM, and a more preferable range is 0.3 to 2.5 μm.

In the antiglare film of the present invention, the layered inorganic compound is contained in a random orientation state in the diffusion layer.
By containing the layered inorganic compound in a random orientation state in the diffusion layer, the diffusion layer can be a starting point for cracks even when stress is applied from various directions due to deformation or the like. Can be prevented. In addition, even when ultraviolet irradiation is performed at the time of producing the diffusion layer, the layered inorganic compound contained in a random orientation state reduces damage due to ultraviolet irradiation, and further, the manufactured antiglare film may be curled. It can prevent suitably.
This is because the layered inorganic compound has a multilayer structure in which the layers are bonded by van der Waals force, and the bonding force between the layers is weak. It is analogized that it is easier to absorb shocks by being able to absorb water. In addition, since such a layered inorganic compound is contained in the diffusion layer in a random orientation state, it is possible to exert the above-described shock absorbing effect against stress applied from all directions of the diffusion layer. It becomes.
That is, the antiglare film of the present invention is extremely excellent in impact resistance because the layered inorganic compound is contained in the diffusion layer in a random orientation state.

As such a layered inorganic compound, talc is particularly preferable. Talc is easy to disperse and exist in the radiation curable binder of the coating liquid in the vertical and horizontal directions due to its physical properties and crystal structure, and the effects of the above-described antiglare film of the present invention are extremely suitably obtained. be able to.
Furthermore, for example, when the diffusion layer contains fine particles (B) described later, the organic fine particles (A) are crosslinked acrylic beads, and the fine particles (B) are polystyrene, the layered inorganic compound is talc. Aggregation of the organic fine particles (A) and fine particles (B) can be suitably controlled. As a result, the antiglare film obtained can be achieved at a high level of antiglare property, white-brown prevention property, and scintillation prevention property.
This is presumed to be due to the fact that the talc is a highly lipophilic substance. That is, the organic fine particles (A) (cross-linked acrylic resin) have hydrophilic properties, and the fine particles (B) (polystyrene) have lipophilic properties. I guess that.

Content of the said layered inorganic compound in the said coating liquid is 2-40 mass parts with respect to 100 mass parts of said radiation-curable binders. If it is less than 2 parts by mass, the impact resistance of the antiglare film of the present invention will be insufficient, and if it exceeds 40 parts by mass, the viscosity of the coating solution for the diffusion layer will increase and coating will not be possible. The unevenness of the film surface cannot be controlled. In addition, when the content of the layered inorganic compound is out of the above range, if the addition amount is too small, the organic fine particles (A) present together may not be present in a random orientation state in the entire diffusion layer. Cannot be controlled appropriately, causing glare. Conversely, if it is excessively present, it is impossible to sufficiently prevent a decrease in contrast. The minimum with preferable content of the said layered inorganic compound is 4 mass parts, and a preferable upper limit is 30 mass parts. By being in this range, the impact resistance effect can be further exerted, and the surface irregularities can be controlled more easily.

The organic fine particles (A) are mainly fine particles that form irregularities on the surface of the diffusion layer to express the surface diffusion function. Examples of the material constituting the organic fine particles (A) include polyester and polystyrene. , Acrylic resin, polyacryl-styrene copolymer resin, olefin resin and the like. Of these, a crosslinked acrylic resin is preferably used. In the present specification, “resin” is a concept including resin components such as monomers and oligomers.
In order to suppress the scintillation of the antiglare film of the present invention, the organic fine particles (A) have a refractive index difference with respect to the radiation curable binder described later, and the diffusion layer has an internal diffusion function. More preferably.
Specifically, when the fine particle (B) described later is not used, the refractive index difference is preferably 0.1 or less. When the fine particle (B) described later is used, the refractive index difference is 0.04 or less. It is preferable that

Examples of the cross-linked acrylic resin include acrylic monomers such as acrylic acid and acrylic acid ester, methacrylic acid and methacrylic acid ester, acrylamide and acrylonitrile, a polymerization initiator such as persulfuric acid, and a cross-linking agent such as ethylene glycol dimethacrylate. A homopolymer or a copolymer obtained by polymerization using a suspension polymerization method or the like is preferable.
As the acrylic monomer, a cross-linked acrylic resin obtained using methyl methacrylate is particularly suitable.

As an average particle diameter of the said organic fine particle (A), the thing of the range of 0.5-15.0 micrometers is suitable, for example. In particular, the range of 1.0-10.0 micrometers is more suitable. When the average particle size is less than 0.5 μm, the antiglare film of the present invention may have insufficient antiglare properties. When it exceeds 15.0 μm, the antiglare film of the present invention is applied. The image on the display may become dull and the image quality may deteriorate.
In addition, the average particle diameter means an average particle diameter if each particle contained in the diffusion layer is a monodisperse type particle (particle having a single shape), and has a broad particle size distribution. In the case of an irregular-shaped particle having a particle size, it means the particle size of the most abundant particle by particle size distribution measurement. The particle size can be measured mainly by the Coulter counter method. In addition to this method, the laser diffraction method, SEM observation of the cross-section of the actually produced anti-glare film, measurement by photography, and measurement by observing the anti-glare film surface with a transmission optical microscope it can.

In the antiglare film of the present invention, the organic fine particles (A) preferably have an impregnation layer impregnated with a radiation curable binder described later in the diffusion layer. In the following description, the organic fine particles (A) on which the impregnation layer is formed, that is, the organic fine particles (A) in the diffusion layer are referred to as “organic fine particles (A2)”.
By having the impregnation layer, the organic fine particles (A2) have extremely excellent adhesion to the cured product of the radiation curable binder (hereinafter also referred to as binder resin) of the diffusion layer. Further, since the impregnation layer in the organic fine particles (A2) is formed in a state in which a radiation curable binder is mixed, the light transmitted through the diffusion layer is transmitted through the organic fine particles (A2) (impregnation layer) and the binder resin. It is possible to suitably prevent scattering at the interface.
Further, as will be described later, the impregnated layer is a layer that is preferably formed by swelling the organic fine particles (A) with the radiation curable binder and / or solvent. It becomes very flexible fine particles. For this reason, although it forms in the position corresponding to the organic fine particle (A2) in this diffusion layer on the surface of the said diffusion layer, the shape of this convex part can be made gentle. This point will be described in more detail later.

The impregnation layer is a layer formed by impregnating the radiation curable binder from the outer surface of the organic fine particles (A2) in the diffusion layer toward the center thereof. The impregnation layer is a layer formed mainly by impregnating a low molecular weight component in the radiation curable binder, that is, a monomer, and is difficult to impregnate a polymer of the radiation curable binder, that is, a polymer or an oligomer.
The impregnated layer can be identified, for example, by observing the cross section of the diffusion layer with an SEM or the like and observing the cross section of the organic fine particles (A2) therein. As a detailed method, the diffusion layer is cut in the thickness direction, and a cross section including at least one organic fine particle (A2) is observed with SEM at a magnification of 3,000 to 50,000 times. At the portion impregnated with the fine particles (A2), the boundary between the organic fine particles (A2) and the surrounding radiation curable binder is relatively clear, and the organic fine particles (A2) are most impregnated with the radiation curable binder. The thickness of the two points that are seen as being measured is measured with an SEM photograph or the like, the same is measured for a total of five organic fine particles (A2), and the average value of the measurement results of the ten points is calculated. If other fine particles are contained in addition to the organic fine particles (A2), the thickness of the impregnated layer on the fine particles can be measured in the same manner as described above.
The radiation curable binder impregnated in the impregnation layer may be impregnated with all the constituent components, or may be impregnated with a part of the constituent components.

The impregnated layer preferably has an average thickness of 0.01 to 1.0 μm. If it is less than 0.01 μm, the effects obtained by forming the above-mentioned impregnation layer may not be sufficiently obtained. If it exceeds 1.0 μm, the internal diffusion function of the organic fine particles (A2) is sufficiently exhibited. In some cases, the effect of preventing scintillation cannot be obtained sufficiently. The more preferable lower limit of the average thickness of the impregnated layer is 0.1 μm, and the more preferable upper limit is 0.8 μm. By being in this range, the above-mentioned effect can be exhibited more.
The average thickness of the impregnated layer means the average value of the thickness of the impregnated layer in the cross section of the organic fine particles (A) observed in the cross-sectional SEM photograph of the antiglare film.

Here, the organic fine particles generally have a cross-linked structure, but the degree of swelling by the radiation curable binder and / or solvent varies depending on the degree of the cross-linking, and the organic fine particles usually have a high degree of cross-linking. If so, the degree of swelling becomes low, and if the degree of crosslinking is low, the degree of swelling becomes high. Therefore, for example, when the material constituting the organic fine particles (A2) is the above-mentioned crosslinked acrylic resin, the thickness of the impregnated layer can be set to a desired range by appropriately adjusting the degree of crosslinking of the crosslinked acrylic resin. Can be controlled.

Further, when the average particle diameter of the organic fine particles (A) is D _A 1 and the average particle diameter of the organic fine particles (A2) in the diffusion layer is D _A 2, the D _A 1 and D _A 2 are as follows: It is preferable to satisfy the formula (2).
0.01 μm <D _A 2−D _A 1 <1.0 μm (2)
In the above formula (2), if “D _A 2 -D _A 1” is less than 0.01 μm, the thickness of the impregnated layer becomes too thin, and the effect obtained by forming the above impregnated layer is obtained. There are times when you can't. When “D _A 2 -D _A 1” exceeds 1.0 μm, the internal diffusion function may not be sufficiently exhibited, and the scintillation preventing effect may not be sufficiently obtained.
The more preferable lower limit of the “D _A 2-D _A 1” is 0.1 μm, and the more preferable upper limit is 0.5 μm. By having “D _A 2 -D _A 1” in this range, the above-described effects can be more exhibited.

The organic fine particles (A) are preferably not aggregated in the diffusion layer. When the organic fine particles (A) in the diffusion layer are aggregated, a large convex portion is formed on the surface of the diffusion layer at a position corresponding to the aggregated organic fine particles (A), and the antiglare film of the present invention has white brown. Or scintillation may occur. In addition, aggregation of the organic fine particles (A) in the diffusion layer can be suitably prevented by, for example, containing the above-described layered inorganic compound. When talc is used as the layered inorganic compound, the organic fine particles can be prevented. Aggregation of (A) can be particularly preferably prevented.

In the antiglare film of the present invention, when the organic fine particles (A) have an impregnation layer in the diffusion layer, the organic fine particles (A) may be, for example, organic fine particles having different degrees of crosslinking in advance. An anti-glare film may be prepared with a coating solution using, and organic fine particles matching a preferable degree of impregnation may be selected and used. The selection of the organic fine particles is influenced by the composition other than the organic fine particles forming the diffusion layer, that is, all the resin compounds, various additives, solvents, etc. contained in the matrix binder, so that the preferable degree of crosslinking is unified. Is not determined. Therefore, fine particles with various degrees of cross-linking are added to the matrix composition selected at each time, the diffusion layer is cured once, and the particles are selected by measuring the thickness of the impregnation layer by the method described above. To do.

Moreover, it is although it does not specifically limit as content of the organic fine particle (A) in the said coating liquid, It is preferable that it is 0.5-30 mass parts with respect to 100 mass parts of radiation-curable binders mentioned later. If the amount is less than 0.5 part by mass, a sufficient uneven shape cannot be formed on the surface of the diffusion layer, and the antiglare performance of the antiglare film of the present invention may be insufficient. On the other hand, when the amount exceeds 30 parts by mass, the organic fine particles (A) are aggregated in the coating liquid, and a large convex portion is formed on the surface of the diffusion layer, which may cause browning or scintillation. The minimum with more preferable content of the said organic fine particle (A) is 1.0 mass part, and a more preferable upper limit is 20 mass parts. By being in this range, the above-mentioned effect can be further ensured.

The coating liquid preferably further contains fine particles (B). The fine particles (B) are mainly fine particles for obtaining internal diffusion. By containing the fine particles (B), it is possible to more suitably prevent scintillation from occurring in the diffusion layer to be formed.
Such fine particles (B) are preferably particles that are not swollen by the radiation-curable binder and / or solvent in the coating liquid. This is because if the fine particles (B) have an impregnated layer, diffusion at the interface between the fine particles (B) and the binder decreases.
Here, “particles that are not swollen” include not only the case where the particles are not swollen by the radiation-curable binder and / or the solvent, but also a case where they are slightly swollen. In the case of “slightly swelled”, an impregnation layer similar to the organic fine particles (A2) is formed on the fine particles (B) in the diffusion layer. The case is smaller than the impregnated layer of organic fine particles (A) and less than 0.1 μm.
Whether or not an impregnation layer is formed on the fine particles (B) in the diffusion layer can be determined by, for example, observing a cross section of the fine particles (B) in the diffusion layer with a microscope (SEM or the like). .
In the following description, the fine particles (B) in the diffusion layer are referred to as “fine particles (B2)”.

Examples of the fine particles (B) that are not swollen by the radiation curable binder and / or solvent include inorganic fine particles such as silica fine particles, polystyrene, melamine resin, polyester, acrylic resin, olefin resin, and copolymers thereof. Among these organic fine particles, those having a higher degree of crosslinking can be mentioned, and organic fine particles whose refractive index and particle size are easily controlled are preferred. These fine particles (B) may be used alone or in combination of two or more.
Among these, since the refractive index is high and it is easy to provide a difference in refractive index from the binder (the refractive index of a normal radiation curable binder is about 1.48 to 1.54), and internal diffusion is easily obtained. Acrylic-styrene copolymer fine particles are preferably used. In the following description, it is assumed that the fine particles (B) are organic particles.
Here, the organic fine particles by acrylic resin and styrene resin are produced by a generally known production method. As materials, acrylic-styrene copolymer resin is used, or core-shell type fine particles are used. There are polystyrene fine particles using fine particles made of acrylic resin for the core, and conversely polyacryl fine particles using fine particles made of styrene resin for the core. In this specification, the distinction between the acrylic fine particles, the styrene fine particles, and the acrylic-styrene copolymer fine particles is determined by which resin has the closest characteristics. For example, if the refractive index of the fine particle is less than ˜1.50, it is regarded as an acrylic fine particle, if it is 1.50 or more and less than 1.59, it is regarded as an acrylic-styrene copolymer fine particle, and if it is 1.59 or more, it is regarded as a styrene fine particle. be able to.

The average particle size of the fine particles (B) is not particularly limited, but may be equal to the average particle size of the organic fine particles (A) described above. However, when the organic fine particles (A) is impregnated layer is swollen by the radiation-curable binder and / or solvent is formed, the average particle size of the organic fine particles (A) and fine particles (B), each D _A 1 and D _B 1, and the average particle diameters of the organic fine particles (A2) and fine particles (B2) in the diffusion layer are D _A 2 and D _B 2, respectively, D _A 1, D _B 1, D _A 2 and D _B 2 preferably satisfy the following formula (3).
D _A 2−D _A 1> D _B 2−D _B 1 ≧ 0 (3)
By satisfy | filling the said Formula (3), while making the unevenness | corrugation of the diffusion layer surface smooth, control of internal diffusion can be made easy, and it can be made more surely prevention of browning and prevention of scintillation.
Incidentally, when the refractive index difference between D B ₂ and radiation effects binder is large (for example, if having a refractive index difference of 0.02 or more) is more preferably D A ₂ is greater than D _{B 2.} In this case, since the inward diffusion of the diffusion layer by D B ₂ is large, the site showing the internal diffusion becomes to be more widely distributed in the diffusion layer, antiglare film generation of glaring and roughness in the present invention reduces It is to be done.

In the antiglare film of the present invention, as the fine particles (B), for example, an antiglare film is prepared in advance with a coating solution using organic fine particles having different crosslinking degrees, and the organic fine particles conform to a preferable degree of impregnation. Can be selected and used.

Although it does not specifically limit as content of microparticles | fine-particles (B) in the said coating liquid, It is preferable that it is 0.5-30 mass parts with respect to 100 mass parts of radiation-curable binders mentioned later. If it is less than 0.5 parts by mass, scintillation is likely to occur in the antiglare film of the present invention, whereas if it exceeds 30 parts by mass, the contrast of the image display layer using the antiglare film of the present invention is lowered. There are things to do. The minimum with more preferable content of the said microparticles | fine-particles (B) is 1.0 mass part, and a more preferable upper limit is 20 mass parts. By being in this range, the above-mentioned effect can be further ensured.

In the antiglare film of the present invention, the radiation curable binder contains a (meth) acrylate monomer as an essential component.
As such a radiation curable binder, those that swell the above-mentioned organic fine particles (A) are preferably exemplified, and transparent ones are preferable, for example, ionizing radiation curable resins that are cured by ultraviolet rays or electron beams. It is done. In the present specification, “(meth) acrylate” refers to methacrylate and acrylate. Moreover, in this specification, since the monomer is ionized radiation cured to form a polymer film, it includes all molecules that can be a structural unit of the basic structure of the polymer film and has an unsaturated bond. That is, if the oligomer or prepolymer is a basic unit of a cured film, the oligomer or prepolymer is also included. In the present invention, the monomer preferably has a small molecular weight of 5000 or less.

Examples of the (meth) acrylate monomer include compounds having one or more unsaturated bonds such as a compound having a (meth) acrylate functional group.
Examples of the compound having one unsaturated bond include ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone and the like. Examples of the compound having two or more unsaturated bonds include polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, polypropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) ) Acrylate, bisphenol F EO modified di (meth) acrylate, bisphenol A EO modified di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, isocyanuric acid EO modified di (meth) acrylate , Isocyanuric acid EO-modified tri (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane PO-modified tri (meth) acrylate Trimethylolpropane EO modified tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neo Examples thereof include polyfunctional compounds such as pentyl glycol di (meth) acrylate and reaction products such as (meth) allylate (for example, poly (meth) acrylate ester of polyhydric alcohol). Moreover, the urethane (meth) acrylate and polyester (meth) acrylate which have two or more unsaturated bonds are also mentioned.
In particular, when the hard coat property of the diffusion layer is important, the radiation curable binder is an acrylate having a trifunctional or higher functional group in 50% (mass ratio) of all monomer components. preferable.

As the ionizing radiation curable resin, in addition to the (meth) acrylate monomer, a relatively low molecular weight polyester resin having an unsaturated double bond, a polyether resin, an acrylic resin, an epoxy resin, a urethane resin, an alkyd resin, Spiroacetal resins, polybutadiene resins, polythiol polyene resins, and the like can also be used as the ionizing radiation curable resin.

When the ionizing radiation curable resin is used as an ultraviolet curable resin, the coating liquid preferably contains a photopolymerization initiator.
Specific examples of the photopolymerization initiator include acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime esters, thioxanthones, propiophenones, benzyls, benzoins, and acylphosphine oxides. It is done. In addition, it is preferable to use a mixture of photosensitizers, and specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine, and the like.

As the photopolymerization initiator, acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether, etc. are used alone or in combination when the ultraviolet curable resin is a resin system having a radical polymerizable unsaturated group. It is preferable. When the ultraviolet curable resin is a resin system having a cationic polymerizable functional group, the photopolymerization initiator includes aromatic diazonium salt, aromatic sulfonium salt, aromatic iodonium salt, metallocene compound, benzoin sulfonic acid. It is preferable to use esters or the like alone or as a mixture.
It is preferable that the addition amount of the said photoinitiator is 0.1-10 mass parts with respect to 100 mass parts of ultraviolet curable resin.

In addition, the ionizing radiation curable resin is used in combination with a solvent-drying resin (a thermoplastic resin, such as a resin that forms a film only by drying a solvent added to adjust the solid content during coating). It can also be used.
Examples of the solvent-drying resin include thermoplastic resins. As the thermoplastic resin, those generally exemplified are used. By adding the solvent-drying resin, coating film defects on the coated surface can be effectively prevented.
Specific examples of preferable thermoplastic resins include, for example, styrene resins, (meth) acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, and polyester resins. , Polyamide resins, cellulose derivatives, silicone resins, and rubbers or elastomers.
As the thermoplastic resin, it is usually preferable to use a resin that is non-crystalline and soluble in an organic solvent (particularly a common solvent capable of dissolving a plurality of polymers and curable compounds). In particular, resins with high moldability or film formability, transparency and weather resistance, such as styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) Etc. are preferred. In particular, a (meth) acrylic resin is particularly preferred because it has a good balance of affinity with acrylate monomers, hardness and optical properties.

According to a preferred embodiment of the present invention, when the material of the light-transmitting substrate is a cellulose resin such as triacetyl cellulose “TAC”, as a preferred specific example of the thermoplastic resin, a cellulose resin such as nitrocellulose, Examples include acetyl cellulose, cellulose acetate propionate, and ethyl hydroxyethyl cellulose. By using the cellulose-based resin, it is possible to improve the adhesion and transparency between the light-transmitting base material and the underlying uneven layer formed as desired.

The coating liquid may further contain a thermosetting resin. Examples of the thermosetting resin include phenol resin, urea resin, diallyl phthalate resin, melanin resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation resin, silicon resin. And polysiloxane resin. When a thermosetting resin is used, a curing agent such as a crosslinking agent and a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier, and the like can be used in combination as necessary.

In the antiglare film of the present invention, when the difference between the refractive index of the radiation curable binder and the refractive index of the organic fine particles (A) and the fine particles (B) is Δ _A and Δ _B , respectively, the Δ _A and delta _B, it is preferable to satisfy the following formula (1).
| Δ _A | <| Δ _B | (1)
By satisfying the above formula (1), there is no scintillation having both internal diffusion with a small diffusion angle due to organic fine particles (A) and internal diffusion with a large diffusion angle due to fine particles (B), and anti-glare with excellent uniformity of screen luminance A film can be obtained.
In addition, arbitrary methods are mentioned as a measuring method of the refractive index of the said radiation-curable binder, organic microparticles (A), and microparticles | fine-particles (B), For example, the Becke method, the minimum deflection angle method, a deflection angle analysis, mode * It can be measured by the line method, ellipsometry method or the like. In addition to measuring the material itself, each method can be used in the same manner for the coating film itself, depending on a method in which fine particles are taken out from the film of the produced antiglare film or a measuring method.
Further, when the radiation curable binder contains the (meth) acrylate and other resins, the refractive index of the radiation curable binder is the refractive index of all the resin components contained excluding fine particles. Say.

The coating liquid preferably further contains a solvent.
The solvent is not particularly limited. For example, water, alcohol (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone), ester ( Examples, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene chloride, chloroform) , Carbon tetrachloride), aromatic hydrocarbons (eg, benzene, toluene, xylene), amides (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ethers (eg, diethyl ether, dioxane, tetrahydrophenol) Emissions), ether alcohols (e.g., 1-methoxy-2-propanol) and the like.

The radiation curable binder and the solvent may both be selected from those having the property of swelling the organic fine particles (A), but only one of them has the property of swelling the organic fine particles (A). You may select and use.
In addition, the formation of the impregnated layer of the organic fine particles (A) is more reliable regardless of the degree of swelling of the radiation curable binder by the presence of a solvent having a property of swelling the organic fine particles (A). Therefore, it is more preferable that at least the solvent has a property of swelling the organic fine particles (A). It is assumed that this is because the organic fine particles (A) are first swelled by the action of the solvent, and then the low molecular weight components contained in the radiation curable binder are impregnated. is doing.
In the antiglare film of the present invention, the combination of the radiation curable binder and the solvent is a (meth) acrylate monomer and the organic solvent as the solvent because the molecular weight is small and the impregnation is easy. It is preferable to use a combination of a strong ketone and / or ester system that swells the fine particles (A).
Moreover, the amount of impregnation of the low molecular weight component contained in the radiation curable binder can be controlled by adjusting the degree of swelling of the organic fine particles (A) by mixing and using the solvent.

The said coating liquid can be prepared by mixing each material mentioned above.
A method for preparing the coating liquid by mixing the above materials is not particularly limited, and for example, a paint shaker or a bead mill may be used.

The said diffusion layer can be formed by apply | coating the said coating liquid on the at least one surface of the said translucent base material, drying, forming a coating film, and hardening this coating film.
The method for applying the coating liquid is not particularly limited, and examples thereof include a roll coating method, a Miya bar coating method, a gravure coating method, and a die coating method.

The thickness of the coating film formed by applying the coating liquid is not particularly limited, and is appropriately determined in consideration of the desired thickness of the diffusion layer, the uneven shape formed on the surface, the material to be used, and the like. Preferably, it is about 1-20 micrometers. If the thickness is less than 1 μm, the coating film hardness is low, and if it exceeds 20 μm, curling of the antiglare film is likely to occur due to polymerization shrinkage of the coating film. In order to make the above-mentioned effect more prominent, 2 to 15 μm is more preferable, and 2 to 10 μm is still more preferable.

As described above, the organic fine particles (A2) are preferably formed by swelling the organic fine particles (A) with the radiation curable binder and / or solvent and impregnating the radiation curable binder to form an impregnation layer. However, the organic fine particles (A2) may be prepared in the coating solution or in a coating film formed by coating on the light-transmitting substrate.

The diffusion layer can be formed by curing the coating film formed on the light transmissive substrate.
Although it does not specifically limit as a hardening method of the said coating film, It is preferable to carry out by ultraviolet irradiation. When curing by ultraviolet rays, it is preferable to use ultraviolet rays having a wavelength range of 190 to 380 nm. Curing with ultraviolet rays can be performed, for example, with a metal halide lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a carbon arc lamp, a black light fluorescent lamp, or the like. Specific examples of the electron beam source include various electron beam accelerators such as a cockcroft-wald type, a bandegraft type, a resonant transformer type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type.

In order to make the layered inorganic compound in a random orientation state in the diffusion layer, the layered inorganic compound such as talc, which is electrically neutral and has few lattice defects, is prepared by, for example, ultrasonic waves. Etc. to uniformly disperse with organic fine particles (A), radiation curable binders and solvents, etc., so that no share is applied when applying the coating liquid to the light transmissive substrate, and convection is reduced during drying. It is preferable to form a coating film. By forming the coating film in this way, the layered inorganic compound can be prevented from being oriented in the coating film, and then the layered inorganic compound is randomly oriented in the diffusion layer formed by curing the coating film. Will be included in the state.
Further, it is more preferable to add 0.0002 to 2.0% by mass of a fluorine-based or siloxane-based surfactant to the coating liquid in order to obtain a random alignment state. It is because the orientation by convection can be prevented by suppressing the convection at the time of drying more effectively. When the addition amount is less than 0.0002% by mass, the effect of suppressing convection becomes insufficient. When the addition amount exceeds 2.0% by mass, the hardness and scratch resistance of the formed diffusion layer may be lowered.

In the antiglare film of the present invention, the diffusion layer has an uneven shape on the surface.
The diffusion layer preferably has a convex portion (hereinafter also referred to as a convex portion (A)) at a position corresponding to the organic fine particles (A) in the diffusion layer.
Further, when the organic fine particles (A) are the organic fine particles (A2) having the above-described impregnation layer, the heights and / or average inclination angles of the convex portions (A) are the following requirements (1), (2 ) And (3) of the convex portion at the position corresponding to the organic fine particles (C) on the surface of the diffusion layer (C) containing the organic fine particles (C) satisfying all of (3) (hereinafter also referred to as convex portion (C)). It is preferred that the height and / or the average inclination angle be lower.
Requirement (1): Requirement for forming the diffusion layer (C) under the same conditions as the diffusion layer containing the organic fine particles (A) except that the organic fine particles (C) are used instead of the organic fine particles (A) (2) : The organic fine particles (C) in the diffusion layer (C) have the same average particle size as the organic fine particles (A) in the diffusion layer (3): The organic fine particles (C) are in the diffusion layer (C) Impregnation layer is not formed

The convex part (A) at a position corresponding to the organic fine particles (A2) has a gentle shape with a lower height and / or average inclination angle than the convex part (C). The antiglare film of the present invention having a diffusion layer having such a convex part (A) can be excellent in antiglare property and anti-glare property.
This is because the organic fine particles (A2) are very flexible as compared with the organic fine particles (C). That is, when the coating film is cured, the radiation curable binder causes curing shrinkage, but the curing shrinkage of the surface where the organic fine particles (A2) are located is the cure shrinkage of the surface where the organic fine particles (A2) are not located. In comparison, the amount of the radiation curable binder is small, so it becomes small. Further, since the organic fine particles (A2) are very flexible fine particles, the organic fine particles (A2) are deformed by the curing shrinkage of the coating film. As a result, the height and / or average inclination angle of the formed convex part (A) is compared with the convex part (C) formed on the surface of the diffusion layer (C) containing the harder organic fine particles (C). I guess it will be low and smooth.
The height of the convex portion refers to an inflection point at which the surface of the antiglare film is observed by AFM and changes from the convex portion to the concave portion present on the slope of the convex portion existing on the surface. It means the average value measured 10 points (arbitrary) to the apex.

The antiglare film of the present invention contains the above-mentioned layered inorganic compound in a random orientation state in the diffusion layer, and therefore the diffusion layer is subjected to stress from various directions due to deformation or the like. Can be prevented from becoming a starting point of cracks. In addition, even when ultraviolet irradiation is performed at the time of producing the diffusion layer, the layered inorganic compound contained in a random orientation state reduces damage due to ultraviolet irradiation, and further, the manufactured antiglare film may be curled. It can prevent suitably.
That is, the antiglare film of the present invention is extremely excellent in impact resistance because the layered inorganic compound is contained in the diffusion layer in a random orientation state.
Furthermore, the antiglare film of the present invention provided with a diffusion layer containing the organic fine particles (A2) has excellent adhesion between the organic fine particles (A2) in the diffusion layer and a cured product of the radiation curable binder. It will be. In addition, it is preferable that the anti-glare film of the present invention does not cause cracks in a mandrel test under the condition that the mandrel diameter is 10 mm, more preferably 8 mm, and even more preferably 6 mm.
The organic fine particles (A2) in the diffusion layer are formed with the above-described impregnation layer, and the impregnation layer is formed in a state where a radiation curable binder is mixed. Is suitable for suitably preventing internal light from being scattered at the interface between the organic fine particles (A) (impregnated layer) in the diffusion layer and the cured product of the radiation curable binder while suitably preventing the light transmitted through the diffusion layer from being scattered. Sex can be expressed.
Furthermore, the convex part formed in the position corresponding to the organic fine particles (A) of the diffusion layer can be formed into a gentle shape with a low height.
Therefore, the antiglare property, the anti-glare property and the scintillation property of the antiglare film of the present invention can be achieved at a high level.

The antiglare film of the present invention preferably has a haze value of 20% or less. If it exceeds 20%, the anti-glare film of the present invention may be white-brown, resulting in inferior image quality of the image display device.
In addition, the said haze value is the value measured using haze meter HR100 (Murakami Color Research Laboratory company make, brand name) according to the haze (cloudiness) prescribed | regulated to JIS-K7136.

The method for producing such an antiglare film of the present invention is also one of the present invention.
That is, the method for producing an antiglare film of the present invention includes an antiglare film having a light-transmitting substrate and a diffusion layer formed on at least one surface of the light-transmitting substrate and having an uneven shape on the surface. A radiation curable binder comprising a layered inorganic compound, organic fine particles (A), and a (meth) acrylate monomer as essential components on at least one surface of the light transmissive substrate, And applying a coating solution containing a surfactant, drying to form a coating film, curing the coating film to form the diffusion layer, and the layered inorganic compound in the diffusion layer. Is contained in a random orientation state that is not oriented by convection of the coating liquid, and has an average particle size of 0.3 to 5 μm.

In the method for producing an antiglare film of the present invention, examples of the material constituting the coating liquid are the same as those described in the above-described antiglare film of the present invention.
Moreover, the process similar to the method demonstrated in the anti-glare film of this invention mentioned above as the process of forming the said diffused layer is mentioned.

Also provided is a polarizing plate comprising a polarizing element, comprising the antiglare film of the present invention by bonding a light-transmitting substrate to the surface of the polarizing element. It is one of the inventions.

The polarizing element is not particularly limited, and for example, a polyvinyl alcohol film, a polyvinyl formal film, a polyvinyl acetal film, an ethylene-vinyl acetate copolymer saponified film, etc. dyed and stretched with iodine or the like can be used. In the laminating process of the polarizing element and the antiglare film of the present invention, it is preferable to saponify the light-transmitting substrate. By the saponification treatment, the adhesiveness is improved and an antistatic effect can be obtained.

This invention is also an image display apparatus provided with the said anti-glare film or the said polarizing plate on the outermost surface. The image display device may be a non-self-luminous image display device such as an LCD, or a self-luminous image display device such as a PDP, FED, ELD (organic EL, inorganic EL), or CRT.

An LCD that is a typical example of the non-self-luminous type includes a transmissive display and a light source device that irradiates the transmissive display from the back. When the image display device of the present invention is an LCD, the antiglare film of the present invention or the polarizing plate of the present invention is formed on the surface of the transmissive display.

In the case where the present invention is a liquid crystal display device having the antiglare film, the light source of the light source device is irradiated from below the antiglare film. Note that in the STN liquid crystal display device, a retardation plate may be inserted between the liquid crystal display element and the polarizing plate. An adhesive layer may be provided between the layers of the liquid crystal display device as necessary.

The PDP, which is the self-luminous image display device, includes a front glass substrate and a rear glass substrate disposed so as to face the front glass substrate with a discharge gas sealed therebetween. When the image display device of the present invention is a PDP, the above-described antiglare film is also provided on the surface of the surface glass substrate or the front plate (glass substrate or film substrate).

The self-luminous image display device is an ELD device that emits light when a voltage is applied, such as zinc sulfide or a diamine substance: a phosphor is deposited on a glass substrate, and the voltage applied to the substrate is controlled. It may be an image display device such as a CRT that converts light into light and generates an image visible to the human eye. In this case, the antiglare film described above is provided on the outermost surface of each display device as described above or the surface of the front plate.

In any case, the antiglare film of the present invention can be used for display display of a television, a computer, a word processor or the like. In particular, it can be suitably used for the surface of high-definition image displays such as CRT, liquid crystal panel, PDP, ELD and the like.

Since the antiglare film of the present invention contains a layered inorganic compound in a random orientation state in the diffusion layer, even if the diffusion layer is subjected to stress from various directions due to deformation or the like, It is possible to prevent cracks from starting. In addition, even when ultraviolet irradiation is performed at the time of producing the diffusion layer, the layered inorganic compound contained in a random orientation state reduces damage due to ultraviolet irradiation, and further, the manufactured antiglare film may be curled. It can prevent suitably.

2 is a cross-sectional SEM photograph of a diffusion layer of an antiglare film obtained in Example 1.

The contents of the present invention will be described with reference to the following examples, but the contents of the present invention should not be construed as being limited to these examples.

Example 1
First, triacetyl cellulose (manufactured by Fuji Film Co., Ltd., thickness 80 μm) was prepared as a light transmissive substrate.
Next, as a radiation curable binder, a mixture of pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), and cellulose acetate propionate (SAP) (mass ratio; PETA / DPHA / SAP = 82/7). / 11) (refractive index 1.51), and low cross-linked acrylic particles (refractive index 1.49, average particle size 5.0 μm) as organic fine particles (A), 100 parts by mass of radiation curable binder In contrast, 6.0 parts by mass of polystyrene particles (refractive index 1.59, average particle size 3.5 μm) as fine particles (B) are 5.0 parts by mass with respect to 100 parts by mass of the radiation curable binder. As a layered inorganic compound, talc particles (refractive index 1.57, average particle size 0.8 μm), radiation curable binder 100 mass Against was included 8.0 parts by weight. Furthermore, 0.003 parts by mass of a non-reactive fluorosurfactant as a surfactant was added to 100 parts by mass of the radiation curable binder. A coating solution was prepared by blending 190 parts by mass of a mixture of toluene and methyl isobutyl ketone (mass ratio 8: 2) as a solvent with respect to 100 parts by mass of the radiation curable binder.
The obtained coating liquid is adjusted so that the coating liquid supply amount and the coating amount coincide with each other (coating liquid supply amount / application amount = 1.0). Then, 70 ° C. dry air was passed at a flow rate of 1.2 m / s and dried for 1 minute to form a coating film.
Thereafter, the coating film was irradiated with ultraviolet rays (200 mJ / cm ² under a nitrogen atmosphere) to cure the radiation curable binder to form a diffusion layer, thereby producing an antiglare film. The film thickness of the diffusion layer was 6.0 μm.

(Examples 2-3, 5, 6, 8, 9, Comparative Examples 1-5, Reference Examples 1 and 2)
Table 1 shows the types of organic fine particles (A) and fine particles (B) to be added to the coating liquid, the types and contents of layered inorganic compounds, the presence or absence of surfactants, and the ratio of (coating liquid supply amount / coating amount). An antiglare film was produced in the same manner as in Example 1 except that the method was as described in 1.

Details of symbols shown in the organic fine particles (A), fine particles (B), layered inorganic compounds and solvents shown in Table 1 are as follows. Moreover, in Table 1, content of a layered inorganic compound shows content (mass part) with respect to 100 mass parts of radiation-curable binders.

(Organic fine particles A)
A: Highly cross-linked acrylic particles (refractive index 1.49, average particle size 5.0 μm, manufactured by Soken Chemical Co., Ltd.)
B: Low cross-linked acrylic particles (refractive index 1.49, average particle size 5.0 μm, manufactured by Soken Chemical Co., Ltd.)

(Fine particle B)
C: Polystyrene particles (refractive index 1.59, average particle size 3.5 μm, manufactured by Soken Chemical Co., Ltd.)

(Layered inorganic compound)
M: Talc (refractive index 1.57, average particle size 0.8 μm, nano talc manufactured by Nippon Talc Co., Ltd.)
N: Bentonite (refractive index 1.52, average particle size 0.1 to 0.5 μm, manufactured by Kunipia F Kunimine Industries)
In addition, the particle diameter of a layered inorganic compound is the average particle diameter D50 by the laser diffraction scattering type particle size distribution measuring method.

(solvent)
Y: Mixture of toluene and methyl isobutyl ketone (mass ratio 8: 2)
Z: Mixture of toluene and isopropyl alcohol (mass ratio 7: 3)

The following evaluation was performed about the anti-glare film obtained by the Example and the comparative example. The results are shown in Table 2.

(Orientation state of layered inorganic compound)
The antiglare films obtained in Examples and Comparative Examples were cut in the thickness direction, and the orientation state of the layered inorganic compound was evaluated by SEM observation of the cross section. In addition, the cross-sectional SEM photograph of the diffusion layer of the anti-glare film which concerns on Example 1 was shown in FIG.
○: The layered inorganic compound of 50% or less was not oriented. ×: The layered inorganic compound exceeding 50% was oriented.

(Haze)
The haze value of the antiglare films obtained in Examples and Comparative Examples was measured using a haze meter HR100 (manufactured by Murakami Color Research Laboratory Co., Ltd.) in accordance with haze (cloudiness) defined in JIS-K7136. .

(Mandrel test)
In accordance with JIS K5600, mandrel tests of the antiglare films obtained in Examples and Comparative Examples were performed with φ6 mm, φ8 mm, and φ10 mm of mandrels, and evaluated according to the following criteria.
◎: No crack at φ6 mm ○: No crack at φ8 mm Δ: No crack at φ10 mm ×: Crack at φ10 mm

(contrast)
The antiglare films obtained in Examples and Comparative Examples were bonded to a black acrylic plate using a transparent adhesive film for optical films, and the surface condition of the antiglare film was measured by 20 subjects at 1000 Lx. Visual sensory evaluation was performed from various directions under room conditions. It was determined whether or not glossy black color could be reproduced, and evaluated according to the following criteria.
◎: 15 or more people who answered good ○: 10-14 people who answered good Δ: 5-9 people who answered good ×: 4 or less people who answered good

(Glitter)
The polarizing plate on the outermost surface of the liquid crystal television “KDL-40X2500” manufactured by Sony Corporation was peeled off, and a polarizing plate without surface coating was attached.
Subsequently, the anti-glare films obtained in Examples and Comparative Examples are further coated on the transparent adhesive film for optical films (total light transmittance of 91% or more, haze of 0.3% so that the diffusion layer side is the outermost surface. Hereinafter, it was pasted by a product having a film thickness of 20 to 50 μm, for example, MHM series: manufactured by Niei Engineering Co., Ltd.
The subject was installed in a room under an environment with an illuminance of about 1,000 Lx, displayed on a white screen, and viewed from various angles up and down and left and right from a location about 1.5 to 2.0 m away from the liquid crystal television. Twenty people performed visual sensory evaluation. It was determined whether or not glare was observed on the white screen display, and evaluation was performed according to the following criteria.
◎: 15 or more people who answered good ○: 10-14 people who answered good Δ: 5-9 people who answered good ×: 4 or less people who answered good

(Thickness of impregnated layer of organic fine particles (A))
The antiglare film is cut in the thickness direction, and the SEM observation of the cross section of the diffusion layer is performed to determine the thickness of the impregnated layer formed on the cross section of the five organic fine particles (A) by 2 points each, for a total of 10 points. The average value was calculated.

As shown in Table 2, when the antiglare film according to the example was observed by SEM cross section, the layered inorganic compound was contained in the diffusion layer in a random orientation state, and in the cross section, the talc particles were about Observed as a linear substance of about 0.5 to 1.5 μm, bentonite particles are observed as a linear substance of about 0.1 to 0.8 μm, and each evaluation of haze value, mandrel test, contrast and glare It was good.
Since the antiglare film according to Comparative Example 1 did not contain a layered inorganic compound in the diffusion layer, it was inferior in each evaluation of mandrel test, contrast, and glare, and the haze value was as high as 22.7%. It was. The antiglare film according to Comparative Example 2 has a low content of the layered inorganic compound added during the preparation of the coating solution, has poor mandrel tests, contrast and glare evaluations, and the layered inorganic compound is in a non-random orientation state. There were many. Moreover, the antiglare film according to Comparative Example 3 contained a large amount of the layered inorganic compound added during the preparation of the coating solution, and could not be uniformly applied to the transparent substrate. Further, in the antiglare films according to Comparative Examples 4 and 5, most of the layered inorganic compounds in the diffusion layer were not in a random orientation state, and were inferior to the mandrel test, contrast, and glare evaluation. .

The antiglare film of the present invention is suitably used for displays such as cathode ray tube display devices (CRT), liquid crystal displays (LCD), plasma displays (PDP), electroluminescence displays (ELD), particularly high definition displays. Can do.

Claims (9)

An anti-glare film having a light-transmitting substrate and a diffusion layer formed on at least one surface of the light-transmitting substrate and having an uneven shape on the surface,
The diffusion layer comprises a layered inorganic compound, an organic fine particle (A), a radiation curable binder containing an (meth) acrylate monomer as essential components, and a coating liquid containing a surfactant. It is formed by applying and drying on at least one of the surfaces to form a coating film, and curing the coating film.
The layered inorganic compound is contained in the diffusion layer in a random orientation state that is not oriented by convection of the coating liquid, and has an average particle diameter of 0.3 to 5 μm. the film. The antiglare film according to claim 1, wherein the layered inorganic compound is talc. The antiglare film according to claim 1 or 2, wherein the coating liquid contains a solvent that swells the organic fine particles (A). The coating liquid further contains fine particles (B), the organic fine particles (A) in the diffusion layer have an impregnation layer impregnated with a radiation curable binder, and the fine particles (B) in the diffusion layer 4. The antiglare film according to claim 1, wherein the antiglare film has an average particle size larger than the average particle size. The antiglare film according to claim 4, wherein the fine particles (B) are fine particles having higher lipophilicity than the organic fine particles (A). When the difference between the refractive index of the radiation curable binder and the refractive index of the organic fine particles (A) and fine particles (B) is Δ _A and Δ _B , Δ _A and Δ _B are expressed by the following formula (1). The antiglare film according to claim 4 or 5, wherein:
| Δ _A | <| Δ _B | (1) A method for producing an antiglare film comprising a light transmissive substrate and a diffusion layer formed on at least one surface of the light transmissive substrate and having an uneven shape on the surface,
A coating containing a layered inorganic compound, organic fine particles (A), a radiation curable binder containing (meth) acrylate monomers as essential components, and a surfactant on at least one surface of the light transmissive substrate. Applying a liquid, drying to form a coating film, curing the coating film to form the diffusion layer,
The layered inorganic compound in the diffusion layer is contained in a random orientation state that is not oriented by convection of the coating liquid, and has an average particle diameter of 0.3 to 5 μm. A method for producing a film. A polarizing plate comprising a polarizing element,
A polarizing plate comprising the antiglare film according to claim 1 on the surface of the polarizing element. An image display device comprising the antiglare film according to claim 1, or the polarizing plate according to claim 8 on an outermost surface.

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