TWI459041B - Anti-glare film, anti-glare film manufacturing method, polarizing film and image display device - Google Patents

Description

Anti-glare film, anti-glare film manufacturing method, polarizing plate and image display device

The present invention relates to an anti-glare film, a method of manufacturing the anti-glare film, a polarizing plate, and an image display device.

An image display device such as a cathode ray tube display device (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), or an electronic paper is usually provided with an optical laminate which is antireflection on the outermost surface. Such an antireflection optical layering system suppresses image reflection or reduces reflectance by light diffusion or interference.

One of the optical laminates for antireflection is known to have an antiglare film having an antiglare layer having an uneven shape formed on the surface of a transparent substrate. This anti-glare film diffuses external light by the uneven shape of the surface, thereby preventing deterioration of visibility.

In the anti-glare film, for example, an anti-glare film in which a resin containing a filler such as silica is applied to the surface of the transparent base film to form an anti-glare layer is known (for example, refer to Patent Documents 1 and 2).

The anti-glare film has the following types: a type in which a cohesive particle or an inorganic and/or an organic filler is added to the resin to form a concavo-convex shape on the surface of the layer; or a film having a concavo-convex film laminated on the surface of the layer to transfer the concavo-convex shape Or a type in which a compound constituting a binder such as two or more kinds of polymers is compatible with each other and phase-separated, thereby forming a type of uneven shape or the like.

The anti-glare film of any of the above types is obtained by utilizing the surface shape of the anti-glare layer to obtain light diffusion and anti-glare effects, and in order to improve the anti-glare property, it is necessary to increase the uneven shape, but if the unevenness is increased, There is a problem that the haze value (turbidity value) of the coating film rises to cause whitening, resulting in a decrease in transmission clarity.

In addition, in the prior type of anti-glare film, there is also a problem that the surface of the film produces a glittering phenomenon called surface flicker, which causes a decrease in visibility of the display screen.

Moreover, in recent years, the high definition of liquid crystal displays has been progressing, and if the previous anti-glare film is used in a high definition liquid crystal display, the occurrence of surface flicker is a more serious problem.

Further, the adhesive resin constituting the antiglare layer is currently an antiglare layer which is cured by ultraviolet irradiation of an ultraviolet curable adhesive resin. Although the antiglare layer is hard, the ability to withstand impact is weak.

In the step of manufacturing the polarizing plate or the step of bonding the polarizing plate and the liquid crystal element, the radius of curvature of the anti-glare film may be reduced, or the load may be locally applied, if an anti-glare layer having the above hard but less impact resistant layer is used. The anti-glare film has the problem that the anti-glare layer is cracked. Further, the liquid crystal display requires high crack resistance, but the local microcrack generated by the load becomes a starting point for cracking, and therefore the antiglare film is required to have crack resistance, that is, impact resistance.

Further, the antiglare film produced by polymerizing and shrinking the ultraviolet curable resin also has a problem of curling.

Patent Document 3 describes an antiglare material obtained by mixing resin beads which are swollen by a solvent by 70% or more with a binder resin.

An anti-glare film having an anti-glare layer formed by using resin beads which are previously swollen by such a solvent can improve the adhesion between the resin beads and the interface of the adhesive resin, and can improve the impact resistance of the anti-glare layer. Therefore, it is expected to be applied to a high definition display.

However, the antiglare film having the antiglare layer formed by using the resin beads which are previously swollen with a solvent improves the adhesion between the swollen resin beads in the antiglare layer and the interface of the binder resin, and is merely due to Since the anchor effect generated by the interface is obtained, there is still room for further improvement in adhesion and the like.

Therefore, in the conventional antiglare film, the impact resistance of the entire antiglare layer is insufficient, and when it is applied to the above-described polarizing plate manufacturing step or the like or a liquid crystal display, cracking of the antiglare layer cannot be sufficiently prevented.

Patent Document 1: Japanese Patent Laid-Open No. Hei 6-18706

Patent Document 2: Japanese Patent Laid-Open No. 10-20103

Patent Document 3: Japanese Laid-Open Patent Publication No. 2005-281476

In view of the above circumstances, an object of the present invention is to provide an anti-glare film which has excellent surface impact resistance and excellent impact resistance, and which can suitably suppress the occurrence of cracks and curls, and a method for producing the anti-glare film, which is applied to the anti-glare film. Polarizer and image display device.

The present invention is an anti-glare film having a light-transmitting substrate and a diffusion layer formed on at least one surface of the light-transmitting substrate, the surface having an uneven shape, and the anti-glare film is characterized by the above The diffusion layer applies a coating liquid containing a layered inorganic compound, organic fine particles (A), and a radiation curable adhesive containing a (meth) acrylate monomer as an essential component to at least one side of the light-transmitting substrate. And the content of the layered inorganic compound in the coating liquid is 2 to 40 parts by mass based on 100 parts by mass of the radiation curable adhesive, and the layer is formed by drying to form a coating film. The inorganic compound is contained in the above diffusion layer in a random alignment state.

In the antiglare film of the present invention, the layered inorganic compound is preferably talc.

Further, the coating liquid preferably contains a solvent which swells the organic fine particles (A).

Further, it is preferable that the coating liquid further contains fine particles (B), and the organic fine particles (A) in the diffusion layer have an impregnation layer impregnated with a radiation-curable adhesive and have particles (B) larger than those in the diffusion layer. The average particle size of the average particle size is large.

The above fine particles (B) are preferably fine particles having a lipophilicity higher than that of the organic fine particles (A).

Further, when the difference between the refractive index of the radiation curable adhesive and the refractive indices 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} preferably satisfied. Said (1).

|Δ _A |<|Δ _B | (1)

Moreover, the present invention is a method for producing 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 a concave-convex shape on the surface. The manufacturing method is characterized by the step of applying a layered inorganic compound, organic fine particles (A), and a (meth) acrylate monomer as essential components to at least one surface of the light-transmitting substrate. The coating liquid of the radiation-curable adhesive is dried to form a coating film, and the coating film is cured to form the diffusion layer; and the layered inorganic compound in the diffusion layer is contained in the diffusion layer in a random alignment state. in.

Further, the present invention is also a polarizing plate comprising a polarizing element, wherein the anti-glare film of the present invention is provided on a surface of the polarizing element.

Further, the present invention is also an image display device comprising the antiglare film of the present invention or the polarizing plate of the present invention on the outermost surface.

Hereinafter, the present invention will be described in detail.

The anti-glare 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 a concave-convex shape on the surface.

The light-transmitting substrate is preferably a substrate having smoothness, heat resistance, and excellent mechanical strength. Specific examples of the material for forming the light-transmitting substrate include polyester (polyethylene terephthalate, polyethylene naphthalate), cellulose triacetate, and cellulose diacetate. Cellulose acetate butyrate, polyamide, polyimine, polyether oxime, polyfluorene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate A thermoplastic resin such as polycarbonate, or a polyurethane or a cyclic polyolefin is preferably a polyester (polyethylene terephthalate, polyethylene naphthalate) or cellulose triacetate. ester.

The light-transmitting substrate is preferably used in the form of the above-mentioned flexible film-like body. However, a plate of the thermoplastic resin may be used in accordance with a use form requiring hardenability, or a glass plate or the like may be used. Plate-shaped body.

The thickness of the light-transmitting substrate is preferably 20 to 300 μm, more preferably 200 μm, and the lower limit is 30 μm. When the light-transmitting substrate is a plate-like body, it may be a thickness larger than the thickness.

Further, when a diffusion layer is formed on the light-transmitting substrate, physical treatment such as corona discharge treatment, plasma treatment, saponification treatment, or oxidation treatment may be performed in advance in order to improve adhesion, and an anchor agent may be applied in advance. (anchor agent) or a coating called a primer.

In the antiglare film of the present invention, the diffusion layer is coated with a coating layer containing a layered inorganic compound, organic fine particles (A), and a radiation curable adhesive containing a (meth) acrylate monomer as an essential component. Drying is performed on at least one surface of the light-transmitting substrate to form a coating film, and the coating film is cured. Further, in the present invention, the diffusion layer means a cured coating film layer unless otherwise specified.

The layered inorganic compound is not particularly limited, and examples thereof include montmorillonite, beidellite, iron bentonite, saponite, lithium bentonite, zinc bentonite, strontite, vermiculite, halloysite, and kaolinite. , Ande stone, Dick stone, talc, pyrophyllite, mica, pearl mica, muscovite, phlogopite, four mica, mica, serpentine, chlorite, chlorite (cookeite), green Nantite, etc. The layered inorganic compound may be a natural substance or a composition. Further, the layered inorganic compound may be subjected to an organic surface treatment.

The particle diameter of the layered inorganic compound can be expressed by an average particle diameter D50 (particle diameter distribution median diameter) measured by a laser diffraction scattering type particle size distribution measurement method. A preferred particle size range is from 0.1 to 9 μm, more preferably from 0.3 to 5 μm.

When the cross section of the actual antiglare film is observed by SEM or the like, the layered inorganic compound is present in the form of plate-like particles having a major axis of about 0.3 to 5 μm.

In order to solve the problem of the present invention, the above-mentioned particle size is too small to exhibit an effect, and if it is too large, the transparency of the entire anti-glare film may be affected.

The particle diameter which can be measured by the result of cross-sectional observation using SEM is more preferably a plate-like particle having a long axis of about 0.3 to 2.5 μm. Further, when the long axis was measured, the average value of the major axes of the ten plate-like particles observed by the SEM cross-section observation was taken.

In the antiglare film of the present invention, the layered inorganic compound is contained in the diffusion layer in a random alignment state. In addition, the term "random" refers to the extension of the long axis or the major axis of the layered inorganic compound in the region in which the thickness of the diffusion layer and the direction perpendicular to the thickness direction (10 μm) are formed in the cross section of the diffusion layer. The lines are in a state of not being parallel to each other. At this time, it is preferred that the layered inorganic compound having a long axis parallel is less than 30%, more preferably less than 20%.

When the layered inorganic compound is contained in the diffusion layer in a random alignment state, even if the diffusion layer receives stress from various directions due to deformation or the like, the starting point of the crack can be prevented. In addition, even when the ultraviolet ray is irradiated during the production of the diffusion layer, the layered inorganic compound contained in a random alignment state can alleviate damage caused by ultraviolet irradiation, and can also suitably prevent the occurrence of the produced anti-glare film. curly.

It is presumed that the above-mentioned layered inorganic compound has a multi-layer structure in which the layers are bonded by van der Waals force, and the bonding force between the layers is weak, so that when subjected to an impact, the sheared by the interlayer can be absorbed. Stress, which makes it easier to absorb shocks. Further, by allowing such a layered inorganic compound to be contained in the diffusion layer in a random alignment state, the impact absorption effect can be exhibited by the stress applied to the diffusion layer from all directions.

In other words, the antiglare film of the present invention is extremely excellent in impact resistance by allowing the layered inorganic compound to be contained in the diffusion layer in a random alignment state.

Among them, the layered inorganic compound is preferably an inorganic compound containing Si, Al, Mg, and O elements, and a compound containing the elements is preferably talc. The talc is easily and freely dispersed due to its physical properties and crystal structure, and is present in the radiation-curable adhesive of the above coating liquid, and the effect of the above-described anti-glare film of the present invention can be suitably obtained.

Further, for example, when the diffusion layer contains fine particles (B) to be described later, the organic fine particles (A) are crosslinked acrylic particles, and the fine particles (B) are polystyrene, if the layered inorganic compound is talc, it may be appropriately The agglomeration of the above organic fine particles (A) and fine particles (B) is controlled. As a result, the obtained antiglare film can achieve high level of antiglare property, blush resistance, and surface flicker resistance.

It is speculated that this is because the above talc is a substance having a relatively lipophilic property. That is, the organic fine particles (A) (crosslinked acrylic resin) have a hydrophilic property, the fine particles (B) (polystyrene) have a lipophilic property, and the oleophilic compound having a high lipophilicity can adjust the aggregation of the two fine particles.

Further, the talc is in the form of a layered structure, and also includes a needle-like or fibrous shape under a cross-sectional microscope.

In the coating liquid, the content of the layered inorganic compound is 2 to 40 parts by mass based on 100 parts by mass of the radiation curable adhesive. When the amount is less than 2 parts by mass, the impact resistance of the antiglare film of the present invention is insufficient. When the amount is more than 40 parts by mass, the viscosity of the coating liquid for the diffusion layer is increased, and the coating film surface cannot be controlled. Bump. In addition, when the content of the layered inorganic compound is out of the above range, if the amount of addition is too small, it is not uniformly present in the entire diffusion layer in a random alignment state, and thus the organic microparticles (A) which are present together cannot be appropriately controlled. Condensation causes surface flicker, and conversely, if it exists excessively, the contrast cannot be sufficiently prevented from falling. A preferred lower limit of the content of the layered inorganic compound is 2 parts by mass, and a preferred upper limit is 30 parts by mass. By setting the content within this range, the impact resistance effect can be further exerted, and the surface unevenness can be more easily controlled.

The organic fine particles (A) are fine particles which form irregularities on the surface of the diffusion layer and exhibit surface diffusion function, and examples of the material constituting the organic fine particles (A) include polyoxymethylene resin, polyester, and polystyrene. , acrylic resin, polyacrylic acid-styrene copolymer resin, olefin resin, and the like. Among them, an acrylic resin can be preferably used, and a crosslinked acrylic resin of a type which changes the degree of crosslinking such as a crosslinking density at the time of producing fine particles is more preferable. Further, in the present specification, the concept of "resin" also includes a resin component such as a reactive or non-reactive polymer, a monomer, or an oligomer.

Furthermore, in order to suppress the surface flicker of the anti-glare film of the present invention, it is more preferable that the organic fine particles (A) have a refractive index difference Δ _A with respect to a radiation-curable adhesive to be described later, thereby providing the diffusion layer with an internal diffusion function. .

Specifically, when the fine particles (B) to be described later are not used, the refractive index difference Δ _{A is} preferably 0.1 or less, and when the fine particles (B) described later are used, the refractive index difference Δ _{A is} preferably 0.04 or less.

The crosslinked acrylic resin is preferably, for example, a polymerization initiator such as persulfuric acid or a crosslinking agent such as ethylene glycol dimethacrylate, and acrylic acid, acrylate, methacrylic acid, and methyl group by a suspension polymerization method or the like. A homopolymer or copolymer obtained by polymerizing an acrylic monomer such as a acrylate, acrylamide or acrylonitrile.

The above acrylic monomer is particularly preferably a crosslinked acrylic resin obtained by using methyl methacrylate.

The average particle diameter of the organic fine particles (A) in the coating film is, for example, preferably in the range of 0.5 to 15.0 μm. In particular, a range of 1.0 to 10.0 μm is more suitable. When the average particle diameter is less than 0.5 μm, the antiglare film and the surface scintillation resistance of the antiglare film of the present invention may be insufficient. When the average particle diameter is less than 15.0 μm, the display of the antiglare film of the present invention may be used. The image caused by blurring of the image contour lacks the roughness caused by the fine density, and the image quality is degraded.

In addition, the above-mentioned average particle diameter refers to an arithmetic mean of the particle diameters of the particles included in the diffusion layer, and is an amorphous particle having a wide particle size distribution. The particle size of the most particles is present by particle size distribution measurement. Further, when it is only in the state of fine particles, the above particle diameter can be measured by a Coulter counter method or the like. However, in addition to the method, the method of measuring the fine particles in the cured film may be performed by SEM observation of the cross section of the actually produced anti-glare film, by taking a photograph of the cross-section, or by using a transmissive optical microscope. The surface of the anti-glare film was observed to measure.

In the antiglare film of the present invention, the organic fine particles (A) preferably have an impregnation layer impregnated with the radiation curable adhesive described later in the diffusion layer. In the following description, the organic fine particles (A) in 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 adhesion between the organic fine particles (A2) and the cured product of the radiation-curable adhesive of the diffusion layer (hereinafter also referred to as "adhesive resin") is extremely excellent. Further, since the impregnated layer of the organic fine particles (A2) is formed in a state in which the radiation-curable adhesive is mixed, the refractive index of the impregnated layer is the refractive index of the radiation-curable adhesive and the refraction of the organic fine particles (A). The refractive index between the rates can suitably reduce the reflection of the transmitted light of the diffusion layer at the interface between the organic fine particles (A2) (the impregnated layer) and the adhesive resin. Further, since the impregnation layer has an appropriate layer thickness, the central portion of the organic fine particles (A2) maintains the refractive index of the initial organic fine particles (A), so that internal diffusion does not decrease, and surface flicker can be effectively prevented.

Further, as described later, the above-mentioned impregnated layer is a layer which is suitably formed by swelling the organic fine particles (A) by the radiation-curable adhesive and/or a solvent, so that the organic fine particles (A2) become extremely flexible. Microparticles.

Therefore, a convex portion is formed on the surface of the diffusion layer corresponding to the position of the organic fine particles (A2) in the diffusion layer, and the shape of the convex portion can be made gentle. Furthermore, this point will be described in more detail later.

The impregnation layer is a layer in which the radiation-curable adhesive is impregnated from the outer surface of the organic fine particles (A2) in the diffusion layer toward the center thereof. In addition, a layer formed by impregnating a low molecular weight component, which is a low-molecular weight component of the impregnated layer-based radiation-curable adhesive, is difficult to be impregnated with a polymer or oligomer of a polymer of a radiation-curable adhesive having a high molecular weight component. However, even oligomers or polymers have a relatively small molecular weight, or sometimes impregnated with the monomer when the monomer is impregnated.

The impregnation layer can be determined, for example, by observing the cross section of the diffusion layer by SEM or the like and observing the cross section of the organic fine particles (A2) therein. The detailed method is: cutting the diffusion layer in the thickness direction, and performing SEM observation on the cross section containing at least one or more organic fine particles (A2) at a magnification of 3,000 to 50,000 times, and impregnating the organic fine particles with the radiation hardening type adhesive. (A2) is a part of the boundary between the organic fine particles (A2) and the surrounding radiation-curing adhesive, and it is measured by SEM photographs, etc., and it is found that the radiation hardening type adhesive is the deepest in the organic fine particles (A2). The thickness of the two points was measured in the same manner for the total of five organic fine particles (A2), and the average value of the measurement results at 10 points was calculated. When it is assumed that other fine particles or the like are contained in addition to the organic fine particles (A2), the thickness of the impregnated layer in the fine particles can be measured in the same manner as described above.

Further, the radiation-curable adhesive impregnated in the impregnation layer may be impregnated with all of the components constituting the radiation-curable adhesive, or may be partially impregnated as one of the components constituting the radiation-curable adhesive. By.

Further, the average thickness of the impregnation layer is preferably from 0.01 to 1.0 μm. If it is less than 0.01 μm, the effect obtained by forming the impregnation layer described above may not be sufficiently obtained. When the thickness is more than 1.0 μm, the internal diffusion function of the organic fine particles (A2) may not be sufficiently exhibited, and may not be sufficient. The situation of preventing the effect of surface flicker is obtained. A more preferable lower limit of the average thickness of the above-mentioned impregnated layer is 0.1 μm, and a more preferable upper limit is 0.8 μm. By making the average thickness of the impregnation layer within this range, the above effects can be further exerted. Further, the diameter of the center portion of the impregnated layer in which the organic fine particles (A2) are not formed is preferably at least the wavelength of light from the viewpoint of ensuring the internal diffusion function and preventing surface flicker.

In addition, the average thickness of the above-mentioned impregnation layer means the average value of the thickness of the impregnation layer of the cross section of the organic microparticles (A) observed in the SEM photograph of the cross section of the anti-glare film.

Here, the organic fine particles generally have a crosslinked structure, and depending on the degree of crosslinking, the degree of swelling caused by the radiation-curable adhesive and/or solvent is different, and generally, if the degree of crosslinking of the organic fine particles is increased, the degree of swelling is increased. When the degree of crosslinking is low, the degree of swelling is increased. Therefore, for example, when the material constituting the above organic fine particles (A2) is the above-mentioned crosslinked acrylic resin, the degree of crosslinking of the crosslinked acrylic resin can be appropriately adjusted, whereby the thickness of the above-mentioned impregnated layer is controlled within a desired range. Further, from the viewpoint of antireflection property and prevention of surface flicker, it is more preferable that the organic fine particles (A2) have a higher degree of crosslinking as they are closer to the center portion, and it is preferably a comparative layer of the organic fine particles (A2). The thickness, the inner side is the degree of cross-linking of non-impregnation, and the closer to the surface, the lower the degree of cross-linking.

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 preferably used. To satisfy the following formula (2).

0.01μm<D _A 2-D _A 1<1.0μm (2)

In the above formula (2), when "D _A 2-D _A 1" is 0.01 μm or less, the thickness of the impregnation layer is too thin, and the effect obtained by forming the impregnation layer cannot be obtained. Happening. When "D _A 2-D _A 1" is 1.0 μm or more, the internal diffusion function cannot be sufficiently exhibited, and the effect of preventing surface flicker may not be sufficiently obtained.

_{A more} preferable lower limit of the above "D _A 2-D _A 1" is 0.1 μm, and a more preferable upper limit is 0.5 μm. By setting "D _A 2-D _A 1" within this range, the above effects can be further exerted.

Further, it is preferable that the organic fine particles (A) are not aggregated in the thickness direction (longitudinal direction) of the diffusion layer in the diffusion layer. When the organic fine particles (A) in the diffusion layer are aggregated and deposited in the thickness direction of the diffusion layer, 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 present invention is The anti-glare film produces whitish or surface flicker. Further, the aggregation of the organic fine particles (A) in the above-mentioned diffusion layer can be suitably prevented by, for example, containing the above-mentioned layered inorganic compound, and when talc is used as the layered inorganic compound, the above organic compound can be particularly suitably prevented. Coagulation of microparticles (A). Further, when the organic fine particles (A) are aggregated in a direction (lateral direction) perpendicular to the thickness direction of the diffusion layer, the above problem is less likely to occur than the aggregation in the longitudinal direction, but if the agglomerate is too large, Since the same problem occurs, it is preferable to add a layered inorganic compound as in the case of aggregation in the longitudinal direction.

Further, in the anti-glare film of the present invention, when the organic fine particles (A) have an impregnation layer in the diffusion layer, the organic fine particles (A) are, for example, previously obtained by using organic fine particles having different degrees of crosslinking. The anti-glare film is prepared by applying the liquid, and the organic fine particles satisfying the preferable impregnation degree can be selected and used. Since the selection of the organic fine particles is affected by the composition other than the organic fine particles forming the diffusion layer, that is, all the resin compounds contained in the matrix binder, various additives, solvents, and the like, the degree of crosslinking is not always uniform. Therefore, in general, fine particles having various degrees of crosslinking are added to the selected matrix composition in advance, and the diffusion layer is temporarily cured to measure the thickness of the impregnation layer by the above method, thereby selecting particles.

In addition, the content of the organic fine particles (A) in the coating liquid is not particularly limited, but is preferably 0.5 to 30 parts by mass based on 100 parts by mass of the radiation-curable adhesive to be described later. When it is less than 0.5 part by mass, a sufficient uneven shape may not be formed on the surface of the diffusion layer, and the antiglare property of the antiglare film of the present invention may be insufficient. On the other hand, when the amount is more than 30 parts by mass, the organic fine particles (A) are likely to be agglomerated in the coating liquid, and the diffusion layer is aggregated in the longitudinal direction or the transverse direction, and is formed on the surface of the diffusion layer. The protrusions thereby produce whitish or surface flicker. A more preferred lower limit of the content of the organic fine particles (A) is 1.0 part by mass, and a more preferred upper limit is 20 parts by mass. By being within this range, the above effects can be more reliably exhibited.

The coating liquid preferably further contains fine particles (B). The fine particles (B) are mainly used for obtaining fine particles which are internally diffused, and by containing the fine particles (B), it is possible to more suitably prevent the surface of the formed diffusion layer from being flickered. Specifically, the fine particles (B) and the difference between the refractive index of the radiation-curable adhesive Δ _B is larger than the organic fine particles (A) and a refractive index difference of the radiation-curable adhesive Δ _A, is preferably 0.2 or less. If it exceeds 0.2, the excessively strong internal diffusion, resulting in a fear of generating white danger decrease in contrast, if the difference is smaller than the refractive index Δ _A, excessively weaken the internal diffusion, the presence can not be sufficiently suppressed flicker surface. In order to obtain the above effects, the refractive index difference Δ _B is more preferably 0.01 or more and 0.1 or less.

Such fine particles (B) are preferably particles which are not swollen by the radiation curable adhesive and/or solvent in the coating liquid. This is because if the fine particles (B) have an impregnation layer, the diffusion of the interface between the fine particles (B) and the binder is reduced.

Here, the "non-swelling particles" include a case where the particles are not swollen by the radiation-curable adhesive and/or the solvent at all, and also slightly swelled. The above-mentioned "slightly swelled" refers to a case where the fine particles (B) form the same impregnation layer as the organic fine particles (A2) in the diffusion layer, but the average thickness of the impregnated layer is smaller than the above organic The impregnation layer of the microparticles (A) is less than 0.1 μm.

To determine whether or not the fine particles (B) in the diffusion layer are formed with an impregnation layer, for example, the cross section of the fine particles (B) of the diffusion layer can be observed by using 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 swelled by the radiation-curable adhesive and/or the solvent include inorganic fine particles such as cerium oxide fine particles, or polystyrene, melamine resin, polyester, or acrylic resin having improved crosslinking degree. The organic fine particles such as an olefin resin or a copolymer thereof are preferably organic fine particles which are easy to control the refractive index and the particle diameter. These fine particles (B) may be used singly or in combination of two or more.

Among them, the polystyrene microparticles and/or the acrylic-styrene copolymer microparticles are easily obtained because of their high refractive index and easy to set a refractive index difference with the binder (the refractive index of the ordinary radiation-curing adhesive is about 1.48 to 1.54). Internal diffusion can be suitably used. In the following, the microparticles (B) will be described as organic particles.

Here, when the organic fine particles of the acrylic resin or the styrene resin are produced by a generally known production method, an acrylic-styrene copolymer resin is used as the material, and if it is a core-shell type fine particle, it is composed of an acrylic resin. The fine particles are used as the core polystyrene fine particles, or conversely, the fine particles composed of the styrene resin are used as the core polyacrylic acid fine particles. In the present specification, the difference between the acrylic fine particles, the styrene fine particles, and the acrylic-styrene copolymerized fine particles can be determined based on the properties of the fine particles and the closest to which resin. For example, if the refractive index of the fine particles is less than 1.50, it can be regarded as acrylic fine particles, and if it is 1.50 or more and less than 1.59, it can be regarded as an acrylic-styrene copolymer fine particle, and if it is 1.59 or more, it can be regarded as a styrene fine particle.

The average particle diameter of the fine particles (B) is not particularly limited, and may be the same as the average particle diameter of the organic fine particles (A). In the case where the organic fine particles (A) are swollen by the radiation-curable adhesive and/or a solvent to form an impregnation layer, the organic fine particles are preferably used in order to sufficiently obtain the effect of adding the fine particles (B). A) the average particle diameter is larger than the fine particles (B) in the diffusion layer, and further, the average particle diameter of the organic fine particles (A) and the fine particles (B), that is, the organic fine particles (A) and the fine particles (B) in the state of the material When the average particle diameter is D _A 1 and D _B 1, respectively, when the average particle diameters of the organic fine particles (A2) and the fine particles (B2) in the diffusion layer are D _A 2 and D _B 2 , respectively, the above D _A 1 , D _B 1 , D _A 2 and D _B 2 preferably satisfy the following formula (3).

1.0μm>D _A 2-D _A 1>D _B 2-D _B 1≧0 (3)

By satisfying the above formula (3), the uneven shape of the surface of the diffusion layer can be made smooth, and the change in the refractive index of the particles due to the impregnation of the particles which contribute to the internal diffusion by the binder or the like can be suppressed, so that the internal diffusion can be easily maintained. And by impregnation, the difference in refractive index between the surface of the particle and the binder is reduced to suppress reflection, so that the anti-glare film of the present invention can be more reliably prevented from being whitened, and surface flicker can be prevented.

In the case where the refractive index difference Δ _B 2 between the fine particles (B) in the diffusion layer and the radiation-curable adhesive is large (for example, when the refractive index difference of Δ _B 2 is 0.02 or more), More preferably, D _A 2 is larger than the above D _B 2 . The reason for this is that by making the average particle diameter of the fine particles (B) having an internal diffusibility larger than that of the organic fine particles (A) small, the fine particles (B) can be widely distributed inside the diffusion layer, and the antiglare of the present invention can be alleviated. The surface of the film is scintillated or rough.

In the anti-glare film of the present invention, the fine particles (B) may be prepared by, for example, using an application liquid of organic fine particles having different degrees of crosslinking, and the organic fine particles satisfying the preferred degree of impregnation may be used.

The content of the fine particles (B) in the coating liquid is not particularly limited, but is preferably 0.5 to 30 parts by mass based on 100 parts by mass of the radiation-curable adhesive to be described later. When the amount is less than 0.5 part by mass, the antiglare film of the present invention is likely to cause surface flicker. On the other hand, when it is more than 30 parts by mass, the contrast of the image display layer using the antiglare film of the present invention may be lowered. A more preferred lower limit of the content of the fine particles (B) is 1.0 part by mass, and a more preferred upper limit is 20 parts by mass. By being within this range, the above effects can be more reliably exhibited.

In the antiglare film of the present invention, the radiation curable adhesive contains a (meth) acrylate monomer as an essential component.

The radiation-curable adhesive may preferably be one in which the organic fine particles (A) are swollen, and preferably has transparency. For example, an external radiation-curable resin which is cured by ultraviolet rays or electron beams may be mentioned. In the present specification, the term "(meth)acrylate" means methacrylate and acrylate. Further, since the monomer in the present specification forms a polymer film by free radiation curing, the monomer contains all molecules which can constitute a constituent unit of the basic structure of the polymer film, and has an unsaturated bond. That is, if the oligomer or prepolymer is the basic unit of the cured film, it also contains an oligomer or a prepolymer. In the present invention, the above monomer is preferably 5,000 or less having a small molecular weight.

The (meth) acrylate monomer may, for example, be a compound having one or two 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, and N-vinylpyrrolidone. Examples of the compound having two or more unsaturated bonds include polymethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and diethyl ether. Diol (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, isomeric cyanuric acid EO modified di(meth) acrylate, isomeric cyanuric acid EO modification Tris(meth)acrylate, trimethylolpropane PO modified tri(meth)acrylate, trimethylolpropane PO modified tri(meth)acrylate, di-trimethylolpropane tetra(a) Acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol penta (meth) acrylate, dipentaerythritol hexa(meth) acrylate, 1,6-hexanediol A reaction product of a polyfunctional compound such as (meth) acrylate or neopentyl glycol di(meth)acrylate with a (meth) acrylate or the like (for example, a poly(meth) acrylate of a polyhydric alcohol). Further, an urethane (meth) acrylate or a polyester (meth) acrylate having two or more unsaturated bonds may also be mentioned.

In the case where the hard coat property of the diffusion layer is important, the radiation-curable adhesive is preferably an acrylate having a reactive group having three or more functional groups, 50% by mass or more of all monomer components.

The above-mentioned free radiation hardening type resin, in addition to the above (meth) acrylate monomer, a relatively low molecular weight polyester resin having an unsaturated double bond, a polyether resin, an acrylic resin, an epoxy resin, an amine ester resin, an alkyd A resin, a spiroacetal resin, a polybutadiene resin, a polythiol polyene resin, or the like can also be used as the above-mentioned free radiation curable resin.

When an ultraviolet curable resin is used as the above-mentioned free radiation curable resin, the coating liquid preferably contains a photopolymerization initiator.

Specific examples of the above photopolymerization initiator include acetophenones, benzophenones, Michler's benzoylbenzoate, and α-amyloxime ester. 9-oxosulfur (thioxanthone), propiophenone, benzil, benzoin, acylphosphine oxido. Further, it is preferably used by mixing a photosensitizer, and specific examples of the photosensitizer include n-butylamine, triethylamine, poly-n-butylphosphine, and the like.

In the photopolymerization initiator, when the ultraviolet curable resin is a resin having a radical polymerizable unsaturated group, it is preferred to use acetophenone, benzophenone, or 9-oxosulfide alone or in combination. (thioxanthone), benzoin, benzoin methyl ether, etc. Further, when the ultraviolet curable resin is a resin having a cationically polymerizable functional group, the photopolymerization initiator is preferably an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic hydrazine or a metal fragrant (metallocene). The compound, benzoin sulfonate or the like is used singly or as a mixture.

The amount of the photopolymerization initiator added is preferably from 0.1 to 10 parts by mass based on 100 parts by mass of the ultraviolet curable resin.

Further, the above-mentioned free radiation curable resin may be used in combination with a solvent-drying resin (a resin which forms a film by drying only a solvent added to adjust a solid content when a thermoplastic resin or the like is applied). At this time, the solvent-drying type resin acts as an additive, and mainly uses an free radiation curing type resin. The amount of the solvent-drying resin to be added is preferably 40% by mass or less based on the total solid content of the resin component contained in the coating liquid.

The solvent-drying type resin is mainly a thermoplastic resin. As the above thermoplastic resin, a thermoplastic resin which is usually exemplified can be used. By adding the solvent-drying resin described above, it is possible to effectively prevent coating film defects on the coated surface.

Specific examples of the preferred thermoplastic resin include a styrene resin, a (meth)acrylic resin, a vinyl acetate resin, a vinyl ether resin, a halogen-containing resin, an alicyclic olefin resin, and a polycarbonate. An ester resin, a polyester resin, a polyamide resin, a cellulose derivative, a polyoxyn resin, a rubber or an elastomer.

The above thermoplastic resin is usually preferably a resin which is amorphous and soluble in an organic solvent (particularly, a solvent which can dissolve a plurality of polymers or a curable compound). Particularly preferred are resins having high moldability, film formability, transparency, and weather resistance, such as styrene resins, (meth)acrylic resins, alicyclic olefin resins, polyester resins, and cellulose derivatives. (cellulose esters, etc.) and the like. In particular, a (meth)acrylic resin is particularly preferable in terms of a good balance of affinity, hardness, and optical characteristics with an acrylate monomer.

According to a preferred embodiment of the present invention, in the case where the material of the light-transmitting substrate is a cellulose resin such as triacetyl cellulose (TAC), a specific example of the thermoplastic resin may be a fiber. A plain resin such as nitrocellulose, acetaminophen, cellulose acetate propionate, ethyl hydroxyethyl cellulose or the like. By using the above-mentioned cellulose-based resin, the adhesion and transparency of the light-transmitting substrate and the underlying uneven layer formed as needed can be improved.

The coating liquid may further contain a thermosetting resin. Examples of the thermosetting resin include a phenol resin, a urea resin, a diallyl phthalate resin, a melamine resin, a guanamine resin, an unsaturated polyester resin, a polyurethane resin, an epoxy resin, and an amino alcohol. An acid resin, a melamine-urea co-condensation resin, an anthracene resin, a polydecane resin, or the like. When a thermosetting resin is used, a curing agent such as a crosslinking agent or a polymerization initiator, a polymerization accelerator, a solvent, a viscosity adjuster, or the like may be used in combination as needed.

In the anti-glare film of the present invention, when the difference between the refractive index of the radiation-curable adhesive after curing and the refractive index of the organic fine particles (A) and the fine particles (B) is Δ _A and Δ _B , respectively, Δ _A and Δ _B preferably satisfy the following formula (1).

|Δ _A |<|Δ _B | (1)

By satisfying the above formula (1), internal diffusion having a small diffusion angle due to the organic fine particles (A) and internal diffusion having a large diffusion angle by the fine particles (B) can be obtained, and no surface flicker and screen brightness can be obtained. An anti-glare film excellent in uniformity.

Further, the method for measuring the refractive index of the radiation-curable adhesive, the organic fine particles (A) and the fine particles (B) may be any method, for example, by the Beck method, the minimum declination method, or the partial deviation method. Angle analysis, mode-line method, ellipsometry, etc. are performed. In each method, in addition to the measurement of the material itself, fine particles taken out from the film of the anti-glare film produced in a certain form may be measured, or some measurement methods may be similarly applied to the coating film itself.

Further, when the radiation curable adhesive contains the above-mentioned (meth) acrylate and other resins and additives, the refractive index of the radiation curable adhesive refers to all resin components other than the hardened microparticles. And the refractive index of the additive.

A preferred method for measuring the refractive index is a radiation curable adhesive, and a method in which only the binder portion is cut out from the cured film and the Beck method is used for measurement. Further, the phase difference can be measured using a penetrating phase shift laser microinterference measuring device PLM-OPT manufactured by NTT Advanced Technology, whereby the refractive index difference between the organic fine particles and the resin component can be measured. Therefore, the refractive index of the organic fine particles can be determined by the refractive index ± refractive index difference of the resin component obtained above.

The coating liquid preferably further contains a solvent.

The solvent is not particularly limited, and examples thereof include an alcohol (for example, methanol, ethanol, isopropanol, butanol, benzyl alcohol) and a ketone (for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone). , cyclopentanone), esters (eg methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg hexane, Cyclohexane), halogenated hydrocarbons (eg dichloromethane, chloroform, carbon tetrachloride), aromatic hydrocarbons (eg benzene, toluene, xylene), guanamine (eg dimethylformamide, dimethylamine) Indoleamine, N-methylpyrrolidone), ether (eg diethyl ether, two Alkane, tetrahydrofuran), ether alcohol (for example 1-methoxy-2-propanol), and the like.

The radiation curable adhesive and the solvent may each be selected to have a property of swelling the organic fine particles (A), and any one of them may be selected to have a property of swelling the organic fine particles (A).

Further, it is more preferable that at least the solvent has a property of swelling the organic fine particles (A) because the organic fine particles can be made irrespective of the degree of swelling of the radiation-curable adhesive. (A) The presence of a solvent of a swelling property, and more reliably forms the impregnation layer of the above organic fine particles (A). It is presumed that the organic fine particles (A) are swollen by first acting on the organic fine particles (A), and then the low molecular weight component contained in the radiation hardening adhesive is impregnated into the organic fine particles (A). .

In the anti-glare film of the present invention, the combination of the radiation-curable adhesive and the solvent is preferably a (meth) acrylate monomer as a radiation-curable adhesive and the organic fine particles (A) as a solvent. A ketone and/or an ester having a strong swelling property is used in combination, and a (meth) acrylate monomer is used as a radiation-curing adhesive because it has a small molecular weight and is easily impregnated. Moreover, by adjusting the degree of swelling of the organic fine particles (A) by mixing and using the above solvent, the amount of impregnation of the low molecular weight component contained in the radiation curable adhesive can be controlled.

Further, when cellulose triacetate (hereinafter also referred to as TAC substrate) is used as the light-transmitting substrate, the interface adhesion between the diffusion layer and the light-transmitting substrate is improved. Further, it is preferable to use a solvent which can swell the TAC substrate and impregnate the TAC substrate with a solvent and a low molecular weight component in the resin component. More preferably, the solvent for swelling the organic fine particles (A) is co-operating with a solvent impregnated in the TAC substrate. That is, when the solvent impregnated into the TAC substrate is substantially the same as the solvent used in the preparation of the organic fine particles (A) having the impregnated layer in advance, the balance of the compound contained in the coating liquid is extremely stable. An excellent coating liquid which can be stably processed even when the antiglare film is processed for a long period of time is obtained.

Such a solvent is preferably methyl isobutyl ketone or the like. Further, the low molecular weight component in the resin component is preferably pentaerythritol tri(meth)acrylate, pentaerythritol penta (meth)acrylate, dipentaerythritol penta(meth)acrylate, Dipentaerythritol hexa(meth) acrylate or the like.

The above coating liquid can be prepared by mixing the above respective materials.

The method of preparing the coating liquid by mixing the above respective materials is not particularly limited, and for example, a paint shaker or a bead mill can be used.

The diffusion layer can be formed by applying the coating liquid onto at least one surface of the light-transmitting substrate, drying it to form a coating film, and curing the coating film.

The coating method of the coating liquid is not particularly limited, and examples thereof include a roll coating method, a mayer 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 can be appropriately determined in consideration of the uneven shape formed on the surface, the material to be used, and the like. When it is 1 μm or more, the hard coat property is excellent, and when it is 20 μm or less, curling is unlikely to occur, and therefore it is preferably about 1 to 20 μm. The thickness of the coating film is more preferably 2 to 15 μm, still more preferably 2 to 10 μm.

The thickness of the diffusion layer can be measured by SEM observation or the like of the cross section of the diffusion layer. In the measurement, the thickness from the surface position of the diffusion layer where the organic fine particles (A2) were not present to the interface of the light-transmitting substrate was measured at 5 or more points, and the average value thereof was determined.

Further, as described above, the organic fine particles (A2) may be formed by swelling the organic fine particles (A) by the radiation-curable adhesive and/or a solvent, and impregnating the organic fine particles (A) with a radiation-curable adhesive. The organic fine particles (A2) can be prepared by the impregnation layer and can be prepared in the coating liquid or in the coating film formed by coating the light-transmitting substrate.

The diffusion layer can be formed by curing the coating film formed on the above-mentioned light-transmitting substrate.

The method of curing the coating film is not particularly limited, and it is preferably carried out by ultraviolet irradiation. In the case of curing by ultraviolet rays, it is preferred to use ultraviolet rays in a wavelength region of 190 to 380 nm. The ultraviolet curing can be performed, for example, using 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: Cockcroft-Walton Type, Van de Graaff Type, resonant transformer type, insulated core transformer type, linear type, Various electron beam accelerators such as Dynamitron Type and high frequency type.

Further, in order to cause the layered inorganic compound to be in a random alignment state in the diffusion layer, it is preferred to use a supersonic wave or the like to make the talc isoelectricity neutral and have fewer lattice defects, for example, by using ultrasonic waves or the like. The layered inorganic compound is uniformly dispersed with the organic fine particles (A), the radiation-curable adhesive, a solvent, and the like, and when the coating liquid is applied onto the light-transmitting substrate, the coating liquid is not divided as much as possible, and convection is reduced during drying. A coating film is formed. By forming the coating film in this manner, the layered inorganic compound can be prevented from being aligned in the coating film, and then the coating film is cured, whereby the layered inorganic compound is contained in the formed diffusion layer in a random alignment state.

Further, in order to obtain a random alignment state, it is more preferable to add 0.0002 to 2.0% by mass of a surfactant such as a fluorine-based or a decane-based surfactant to the coating liquid. This is because the convection at the time of drying can be suppressed more effectively, and the alignment due to convection can be prevented. When the amount of addition is less than 0.0002% by mass, the effect of suppressing convection is insufficient. When the amount is more than 2.0% by mass, the hardness or 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 at least the organic fine particles (A) in the diffusion layer.

Further, when the organic fine particles (A) are the organic fine particles (A2) having the impregnated layer, the convex portion (A) preferably has a height and/or an average tilt angle and contains the following element (1), The height of the convex portion (hereinafter, also referred to as a convex portion (C)) at the position of the diffusion layer (C) of all the organic fine particles (C) of (2) and (3) corresponding to the position of the organic fine particles (C) and/or Or the average tilt angle is small.

Element (1): A diffusion layer (C) is formed 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); the element (2): a diffusion layer ( The organic fine particles (C) in C) have the same average particle diameter as the organic fine particles (A) in the diffusion layer; the element (3): the organic fine particles (C) do not form the impregnated layer in the diffusion layer (C).

The convex portion (A) corresponding to the position of the organic fine particles (A2) has a smaller height and/or an average inclination angle than the convex portion (C), and has a gentle shape. The antiglare film of the present invention having the diffusion layer in which such a convex portion (A) is formed can obtain excellent antiglare properties and blush resistance.

The reason for this is considered to be that the organic fine particles (A2) are very rich in soft particles as compared with the organic fine particles (C). In other words, when the coating film is cured, the radiation-curable adhesive is hardened and shrunk, but the hardening shrinkage of the surface of the organic fine particles (A2) is not accompanied by the hardening shrinkage of the surface of the organic fine particles (A2). It is reduced due to the above-mentioned radiation hardening type bonding amount being small. Further, it is presumed that since the organic fine particles (A2) are fine particles which are extremely rich in flexibility, the organic fine particles (A2) are deformed by hardening and shrinkage of the coating film. As a result, the height and/or the average tilt angle of the formed convex portion (A) is lower than that of the convex portion (C) formed by the surface of the diffusion layer (C) containing the harder organic fine particles (C). smooth.

In addition, the height of the above-mentioned convex portion is obtained by observing the surface of the anti-glare film using AMF, and the convex portion existing on the surface, and other convex portions adjacent to the convex portion and the convex portion. The difference between the concave portions was measured as the height n (n is 1 to 10) of the convex portion. Then, the heights of any of the ten convex portions thus obtained are averaged.

In the antiglare film of the present invention, since the layered inorganic compound is contained in the diffusion layer in a random alignment state, even if the diffusion layer receives stress from various directions due to deformation or the like, the starting point of the crack can be prevented. Further, even when the diffusion layer is formed, ultraviolet irradiation is performed, and the layered inorganic compound contained in a random alignment state can alleviate damage caused by ultraviolet irradiation, and can effectively prevent curling of the produced anti-glare film. .

In other words, the layered inorganic compound is contained in the diffusion layer in a random alignment state, whereby the antiglare film of the present invention is extremely excellent in impact resistance.

Further, the anti-glare film of the present invention comprising the diffusion layer containing the organic fine particles (A2) is difficult to accumulate strain due to stress in various directions due to deformation or the like, and therefore organic fine particles in the diffusion layer (A2) The adhesion to the cured product of the radiation-curable adhesive is extremely excellent. Further, the antiglare film of the present invention preferably has no crack in the mandrel test under the condition that the diameter of the mandrel is 10 mm, more preferably 8 mm, and still more preferably 6 mm.

Further, since the impregnation layer is formed in the organic fine particles (A2) in the diffusion layer, and the impregnation layer is formed in a state in which a radiation-curable adhesive is mixed, the diffusion layer and the organic fine particles in the diffusion layer are formed. The difference in refractive index between the cured product of (A) (the impregnated layer) and the radiation-curable adhesive is reduced, and the reflection at the interface can be appropriately reduced. Further, since the impregnation layer has an appropriate layer thickness, the center of the organic fine particles (A) is maintained at the initial refractive index of the organic fine particles (A), so that moderate internal diffusibility can be exhibited, and surface flicker can be suitably prevented.

Further, the height of the convex portion formed at the position of the corresponding organic fine particles (A) of the diffusion layer can be made low, and the shape can be formed into a gentle shape.

Therefore, the anti-glare film of the present invention can achieve high levels of anti-glare, blush resistance and surface scintillation resistance.

The turbidity value of the anti-glare film of the present invention is preferably 30% or less. If it is more than 30%, the anti-glare film of the present invention may be whitened, and the image quality of the image display device may be poor.

In addition, the turbidity value is a value measured by the turbidity meter HR100 (manufactured by Murakami Color Research Laboratory Co., Ltd., trade name) according to the turbidity (haze) prescribed by JIS-K7136. Further, the turbidity in the present invention is a value measured by the method.

Further, the method of producing the above-described antiglare film of the present invention is also one of the present inventions.

In other words, the method for producing an anti-glare film according to the present invention includes a light-transmitting substrate and a method for producing a diffusion layer having a concavo-convex shape on at least one surface of the light-transmitting substrate, and the manufacturing method is characterized in that: A step of applying a radiation-curable adhesive containing a layered inorganic compound, organic fine particles (A), and a (meth) acrylate monomer as an essential component to at least one surface of the light-transmitting substrate. The coating liquid is dried to form a coating film, and the coating film is cured to form the diffusion layer; and the layered inorganic compound in the diffusion layer is contained in the diffusion layer in a random alignment state.

In the method for producing an anti-glare film of the present invention, the material constituting the coating liquid may be the same as those described in the above-described anti-glare film of the present invention.

Further, the step of forming the diffusion layer may be the same as the method described in the above-described antiglare film of the present invention.

Further, a polarizing plate having a polarizing element and having the following characteristics is one of the features of the present invention. The polarizing plate of the present invention is characterized in that the surface of the polarizing element is bonded to a light-transmitting substrate or the like. Anti-glare film.

The polarizing element is not particularly limited, and for example, a polyvinyl alcohol film which is dyed by iodine or the like and extended, a polyvinyl formaldehyde film, a polyvinyl acetal film, an ethylene-vinyl acetate copolymer saponified film, or the like can be used. In the lamination treatment of the polarizing element and the antiglare film of the present invention, it is preferred to subject the light-transmitting substrate to a saponification treatment. By the saponification treatment, the adhesiveness becomes good and an antistatic effect can also be obtained.

The present invention also provides an image display device comprising the above-described anti-glare film or the polarizing plate on the outermost surface. Examples of the image display device include LCD, PDP, FED, ELD (organic EL, inorganic EL), CRT, touch panel, and electronic paper.

The LCD includes a transmissive display and a light source device that illuminates the transmissive display from the back surface. In the case where 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 including the above anti-glare film, the light source of the light source device is irradiated from the lower side of the anti-glare film. Further, in the STN type liquid crystal display device, a phase difference 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 needed.

The PDP includes a front glass substrate and a back glass substrate that is disposed to face the surface glass substrate and enclose a discharge gas therebetween. In the case where the image display device of the present invention is a PDP, the anti-glare film is provided on the surface of the surface glass substrate or the front plate (glass substrate or film substrate).

The other image display device may be an ELD device that vapor-deposits zinc sulfide or a diamine-based substance that emits a voltage on a glass substrate as an illuminant, controls display of a voltage applied to the substrate, or converts the electric signal into Light, an image display device such as a CRT that produces an image visible to the human eye. At this time, the anti-glare film is provided on the outermost surface of each display device or the surface of the front plate thereof as described above.

The anti-glare film of the present invention can be used for display on a television, a computer or the like in any case. In particular, it can be preferably used for the surface of a display for high definition image such as a liquid crystal panel, a PDP, an ELD, a touch panel, or an electronic paper.

In the anti-glare film of the present invention, the layered inorganic compound is contained in the diffusion layer in a random alignment state. Therefore, even when the diffusion layer receives stress from various directions due to deformation or the like, the starting point of the crack can be prevented. In addition, even when the ultraviolet ray is irradiated during the production of the diffusion layer, the layered inorganic compound contained in a random alignment state can alleviate damage caused by ultraviolet irradiation, and can also suitably prevent the occurrence of the produced anti-glare film. curly.

The contents of the present invention are illustrated by the following examples, but the contents of the present invention are not limited by the examples.

(Example 1)

First, triacetyl cellulose (manufactured by Fujifilm Co., Ltd., thickness: 80 μm) was prepared as a light-transmitting substrate.

Then, a mixture of neopentyl alcohol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA) and cellulose acetate propionate (SAP) was used (mass ratio: PETA/DPHA/SAP=82/7/ 11) As a radiation curable adhesive (refractive index: 1.51), 1-hydroxycyclohexyl phenyl ketone: Irgacure 184 (manufactured by BASF Corporation) was used as a photopolymerization initiator (100 parts by mass relative to the binder) 5% by mass of low-crosslinking acrylic particles (refractive index: 1.49, average particle diameter: 5.0 μm) as an organic fine particle (A), relative to radiation, in an amount of 6.0 parts by mass based on 100 parts by mass of the radiation-curable adhesive. 100 parts by mass of the curable adhesive is 5.0 parts by mass of polystyrene particles (refractive index: 1.59, average particle diameter: 3.5 μm) as fine particles (B), and 8.0 parts by mass based on 100 parts by mass of the radiation curable adhesive. The talc particles (refractive index: 1.57, average particle diameter: 0.8 μm) were used as the layered inorganic compound. Further, 0.003 parts by mass of a non-reactive fluorine-based surfactant is added as a surfactant to 100 parts by mass of the radiation-curable pressure-sensitive adhesive. A mixture of toluene and methyl isobutyl ketone (mass ratio: 8:2) in an amount of 190 parts by mass based on 100 parts by mass of the radiation-curable adhesive was prepared as a solvent, thereby preparing a coating liquid.

By applying the coating liquid supply amount and the coating amount to the same by the gravure printing method (coating liquid supply amount/coating amount=1.0), the obtained coating liquid is applied to the light-transmitting substrate without division. The film was dried by drying at 70 ° C for 1 minute at a flow rate of 1.2 m/s to form a coating film.

Then, the coating film was irradiated with ultraviolet rays (200 mJ/cm ^{2 in a} nitrogen atmosphere) to cure the radiation-curable adhesive to form a diffusion layer, thereby producing an anti-glare film. Further, the film thickness of the diffusion layer was set to 6.0 μm.

(Examples 2 to 11 and Comparative Examples 1 to 5)

In addition to the types of the organic fine particles (A) and the fine particles (B) to be added to the coating liquid, the type and content of the layered inorganic compound, the presence or absence of the surfactant, and the (coating amount/coating amount) An anti-glare film was produced in the same manner as in Example 1 except as shown in FIG.

The details of the symbols indicated in the organic fine particles (A), the fine particles (B), the layered inorganic compound and the solvent shown in Table 1 are as follows. In addition, in Table 1, the content of the layered inorganic compound is a content (parts by mass) based on 100 parts by mass of the radiation curable adhesive.

(Organic Microparticles A)

A: highly crosslinked acrylic particles (refractive index of 1.49, average particle diameter of 5.0 μm, manufactured by Soken Chemical Co., Ltd.)

B: low crosslinked acrylic particles (refractive index of 1.49, average particle diameter of 5.0 μm, manufactured by Soken Chemical Co., Ltd.)

(Microparticle B)

C: polystyrene particles (refractive index: 1.59, average particle diameter: 3.5 μm, manufactured by Amika Chemical Co., Ltd.)

(layered inorganic compound)

M: talc (refractive index: 1.57, average particle diameter: 0.8 μm, Nano Talc, manufactured by Nippon Talc Co., Ltd.)

N: bentonite (refractive index of 1.52, average particle diameter of 0.1 to 0.5 μm, Kunipia F, manufactured by Kunimine Industries, Ltd.)

Further, the particle diameter of the layered inorganic compound is an average particle diameter D50 measured by a laser diffraction scattering type particle size distribution measurement method.

(solvent)

Y: a mixture of toluene and methyl isobutyl ketone (mass ratio 8:2)

Z: a mixture of toluene and isopropanol (mass ratio of 7:3)

The antiglare films obtained in the examples and the comparative examples were subjected to the following evaluations. The evaluation results are shown in Table 2.

(random alignment state of layered inorganic compound)

The antiglare film obtained in the examples and the comparative examples was cut in the thickness direction, and the cross section of the diffusion layer was subjected to SEM observation on the thickness of the diffusion layer and the region perpendicular to the thickness direction (10 μm). Thereby, the alignment state of the layered inorganic compound was evaluated.

Further, Fig. 1 shows a cross-sectional SEM photograph of a diffusion layer of the antiglare film of Example 1.

◎: Among the layered inorganic compounds observed, the extension of the major axis or the major axis is less than 20% of the extension of the major axis or the major axis of the other layered inorganic compound;

○: in the layered inorganic compound observed, the extension of the major axis or the major axis is 20% or more and less than 30% in parallel with the extension of the major axis or the major axis of the other layered inorganic compound;

X: Among the layered inorganic compounds observed, the extension of the major axis or the major axis is 30% or more parallel to the extension of the major axis or the major axis of the other layered inorganic compound.

(turbidity)

The turbidity of the anti-glare film obtained in the examples and the comparative examples was measured using a haze meter HR100 (manufactured by Murakami Color Research Laboratory Co., Ltd.) in accordance with the turbidity (haze) prescribed in JIS-K7136.

(mandrel test)

The anti-glare film obtained in the examples and the comparative examples was subjected to a mandrel test in accordance with JIS K5600 on Φ 6 mm, Φ 8 mm, and Φ 10 mm of the mandrel, and evaluated according to the following criteria.

◎: no crack occurs at Φ 6mm

○: no crack occurs at Φ 8mm

△: no crack occurs at Φ 10mm

×: Crack occurred at Φ 10mm

(contrast)

The anti-glare film obtained in the examples and the comparative examples was bonded to a black acrylic plate using a transparent adhesive film for an optical film, and the test was performed in all directions by 20 subjects under a light room condition of 1000 Lx. The surface state of the glare film was evaluated visually. It was judged whether or not the glossy black was reproducible and evaluated according to the following criteria.

◎: The answer is good for more than 15 people.

○: The answer is good for 10 to 14 people.

△: The answer is good for 5 to 9 people.

×: The answer is good for 4 or less people.

(sparkling surface)

The polarizing plate on the outermost surface of the LCD TV "KDL-40×2500" manufactured by Sony Corporation was peeled off, and a polarizing plate having an uncoated surface was attached.

Next, a transparent adhesive film for an optical film is used on the polarizing plate (a product having a total light transmittance of 91% or more, a haze of 0.3% or less, and a film thickness of 20 to 50 μm, for example, an MHM series: Rirong Chemical Co., Ltd. The company made the same, and attached the anti-glare film obtained in the examples and the comparative examples so that the side of the diffusion layer became the outermost surface.

The liquid crystal television was placed in a room with an illuminance of about 1,000 Lx, and white screen display was performed. The visually functional evaluation was performed from the top, bottom, left and right angles by the subjects of the subjects from about 1.5 to 2.0 m from the liquid crystal television. It was judged whether or not surface flicker was observed in the white screen display, and evaluation was performed according to the following criteria.

◎: The answer is good for more than 15 people.

○: The answer is good for 10 to 14 people.

△: The answer is good for 5 to 9 people.

×: The answer is good for 4 or less people.

(thickness of the impregnated layer of organic fine particles (A))

The anti-glare film was cut in the thickness direction, and the thickness of the two layers of the impregnation layer formed by the cross section of the five organic fine particles (A) was measured at 10 points in the SEM observation of the cross section of the diffusion layer, and the average value was calculated.

As shown in Table 2, as a result of SEM cross-section observation of the anti-glare film of the example, the layered inorganic compound was contained in the diffusion layer in a random alignment state, and the talc particles were observed in the cross section, and the long axis was about 0.5~. A linear substance of about 1.5 μm was observed, and the bentonite particles were observed to be linear substances of about 0.1 to 0.8 μm, and the evaluations of turbidity, mandrel test, contrast, and surface flicker were good.

Since the antiglare film of Comparative Example 1 did not contain a layered inorganic compound in the diffusion layer, evaluation of the mandrel test, contrast, and surface flicker was inferior. The anti-glare film of Comparative Example 2 has a small content of the layered inorganic compound added at the time of preparing the coating liquid, and the evaluation of the mandrel test, the contrast and the surface flicker is poor, and the layered inorganic compound also has a large amount of non-random alignment. State. Further, the antiglare film of Comparative Example 3 had a large content of the layered inorganic compound added at the time of preparing the coating liquid, and was not uniformly applied to the transparent substrate. Further, in the antiglare films of Comparative Examples 4 and 5, many of the layered inorganic compounds in the diffusion layer were not formed in a random alignment state, and evaluations of the mandrel test, contrast, and surface flicker were inferior.

[Industrial availability]

The anti-glare film of the present invention can be suitably used for a display of a cathode ray tube display device (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), a touch panel, an electronic paper, and the like. In particular, it can be suitably used for a high definition display.

Fig. 1 is a cross-sectional SEM photograph of a diffusion layer of an anti-glare film obtained in Example 1.

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 a concave-convex shape on the surface, the anti-glare film being characterized in that the diffusion layer is A coating liquid containing a layered inorganic compound, organic fine particles (A), and a radiation curable adhesive containing a (meth) acrylate monomer as an essential component and a surfactant is applied to the light-transmitting substrate. At least one surface is dried to form a coating film, and the coating film is cured. The layered inorganic compound is contained in the diffusion layer in a random alignment state which is not aligned by the convection of the coating liquid, and the average particle is contained in the diffusion layer. The diameter is 0.3~5μm. The anti-glare film of claim 1 is characterized in that the layered inorganic compound is talc. An anti-glare film according to claim 1 or 2, wherein the coating liquid contains a solvent which swells the organic fine particles (A). An anti-glare film according to claim 1 or 2, wherein the coating liquid further contains fine particles (B), and the organic fine particles (A) in the diffusion layer have an impregnation layer impregnated with a radiation-curable adhesive, and have An average particle diameter larger than the average particle diameter of the fine particles (B) in the diffusion layer. The anti-glare film of claim 4, wherein the fine particles (B) are higher in lipophilicity than the fine particles of the organic fine particles (A). The anti-glare film of the fourth aspect of the invention, wherein the difference between the refractive index of the radiation-curable adhesive 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 satisfy the following formula (1): |Δ _A |<|Δ _B | (1). A method for producing 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 a concave-convex shape on the surface, the manufacturing method is characterized in that A step of applying a radiation-curable adhesive containing a layered inorganic compound, organic fine particles (A), and a (meth) acrylate monomer as an essential component to at least one surface of the light-transmitting substrate. And a coating liquid of the surfactant, drying to form a coating film, and curing the coating film to form the diffusion layer; the layered inorganic compound in the diffusion layer is not aligned by the convection of the coating liquid It is contained in the state of the alignment, and the average particle diameter is 0.3 to 5 μm. A polarizing plate comprising a polarizing element, wherein an anti-glare film of the first or second aspect of the patent application is provided on a surface of the polarizing element. An image display device comprising an anti-glare film or a polarizing plate according to claim 1 or 2 on the outermost surface, wherein the polarizing plate is provided with a polarizing element, and the anti-glare film is provided on a surface of the polarizing element.