TWI588020B - 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.

In 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, an antireflection optical is usually disposed on the outermost surface. Laminated body. Such an optical laminate for antireflection suppresses reflection of an image or reduces reflectance by diffusion or interference of light.

As one of the optical laminates for antireflection, an antiglare film having an antiglare layer having an uneven shape is formed on the surface of a transparent substrate. The anti-glare film can prevent the visibility from deteriorating by diffusing external light by utilizing the uneven shape of the surface. Further, such an anti-glare film is usually provided on the outermost surface of the image display device, and therefore a certain degree of hard coat property is also required.

In the conventional anti-glare film, for example, it is known to apply a resin containing a filler such as silica to form an anti-glare layer (see, for example, Patent Documents 1 and 2).

Such a conventional anti-glare film has a type in which agglomerated particles or inorganic and/or organic fillers are added to the resin to form a concavo-convex shape on the surface of the layer, or a film having irregularities is laminated on the surface of the layer to transfer the type of the concavo-convex shape. Alternatively, the type of the concavo-convex shape or the like is formed by phase-separating the compatibility of the compounds constituting the binder with two or more kinds of polymers.

Any of the above-mentioned types of anti-glare films obtains light diffusion and anti-glare effects by the action of the surface shape of the anti-glare layer, and in order to improve the anti-glare property, it is necessary to increase the uneven shape of the surface of the anti-glare layer. A method of increasing the unevenness of the surface of the anti-glare layer is, for example, a method of forming an aggregate in which the fine particles are aggregated in the anti-glare layer. For example, Patent Document 3 discloses that the primary particles as fine particles are aggregated. An anti-glare layer of condensed particles.

However, the particles of the agglomerated form in Patent Document 3 have the following problems, and the average particle diameter of the primary particles is extremely small at 0.005 to 0.03 μm, and it is actually difficult to arbitrarily control the aggregation form in which such fine primary particles are aggregated in a large amount, and it is impossible to The uneven shape of the surface of the formed anti-glare layer is controlled to a desired shape.

In addition, for example, Patent Document 4 describes an optical layered body in which the total fog value and the internal haze value have a specific relationship, and the antiglare layer having the uneven shape on the outermost surface contains the agglomerated fine particles.

However, the anti-glare layer described in Patent Document 4 does not investigate the control of the aggregation state of the fine particles, and contains a large amount of aggregates which are aggregated in the thickness direction of the anti-glare layer or in the plane of the anti-glare layer. Condensed by the direction of condensation. Therefore, the optical laminate described in Patent Document 4 has a problem that a large number of large convex portions are formed on the surface of the anti-glare layer, and the occurrence of fading cannot be sufficiently controlled, and the brilliance of the so-called flicker is also generated, and The visibility of the display is reduced.

Further, for example, Patent Document 5 discloses an antiglare layer including an aggregate containing fine particles, and the fine uneven shape on the surface of the antiglare layer is an arithmetic mean roughness Ra and a root mean square inclination RΔ _q within a specific range. Glare film.

However, in the case where the aggregate of the anti-glare layer-based fine particles described in Patent Document 5 is agglomerated in the in-plane direction of the anti-glare layer, the anti-glare layer containing such an aggregate does not have sufficient antiglare properties, but also in the in-plane direction. Condensed aggregates increase the amount of reflected light and cause fading.

Further, for example, Patent Document 6 describes an anti-glare film having a surface roughness of ten on the surface of the anti-glare layer in a specific range, and the anti-glare layer contains particles of an amorphous aggregate.

However, in Patent Document 6, the aggregation state of the particles of the amorphous aggregates contained in the antiglare layer is not studied, but the aggregates in which the particles are aggregated in the height direction of the antiglare layer are described in the antiglare layer. Or agglomerates in which particles are condensed in the direction of the surface of the anti-glare layer. Therefore, the anti-glare film described in Patent Document 6 has a problem in that a large number of large convex portions are formed on the surface of the anti-glare layer, and the occurrence of fading cannot be sufficiently suppressed, and the brilliance of the so-called flicker is generated to cause display. The visibility of the picture is reduced.

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. 2009-008782

Patent Document 4: International Publication No. 2008-020587

Patent Document 5: Japanese Laid-Open Patent Publication No. 2008-233870

Patent Document 6: JP-A-2008-191310

The present invention has been made in view of the above circumstances, and an object thereof is to provide an anti-glare which is excellent in anti-glare property, can sufficiently suppress generation of fading, has high contrast, can also prevent occurrence of flicker, and is also hard-coated. A film, a method for producing the antiglare film, a polarizing plate to which the antiglare film is applied, and an image display device.

The present invention relates to an anti-glare film which has 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, wherein the diffusion layer is A coating liquid containing the fine particles (A) and a radiation-curable adhesive containing a (meth) acrylate monomer as an essential component is applied onto at least one surface of the light-transmitting substrate, and dried to form a coating film. And the coating film is cured, and 50% or more of the fine particles (A) in the diffusion layer are formed by aggregating a line connecting the centers of the opposite sides with respect to the surface of the light-transmitting substrate. 2 aggregates.

In the antiglare film of the present invention, it is preferable that the two microparticles (A) forming the agglomerate form a straight line connecting the centers of the microparticles (A) and the surface of the light transmissive substrate to have an inclination angle of 20 to 70°.

Further preferably, the coating liquid further contains a layered inorganic compound.

Further preferably, the layered inorganic compound is talc.

Moreover, it is preferable that 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.

Further preferably, the fine particles (A) are styrene fine particles and/or acrylic acid-styrene copolymerized fine particles.

Further, preferably, when the average particle diameter of the fine particles (A) is D _A , the thickness T of the D _A with respect to the diffusion layer satisfies the following formula (A): (1.34 × D _A ) < T < (1.94 ×D _A ) (A).

Further, it is preferable that the coating liquid further contains organic fine particles (B), and the average particle diameter of the organic fine particles (B) in the diffusion layer is larger than the fine particles (A) in the diffusion layer.

Further preferably, the organic fine particles (B) in the diffusion layer are not aggregated.

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

Further, it is preferable that the organic fine particles (B) in the diffusion layer have an impregnation layer impregnated with a radiation-curable adhesive, and the average thickness of the impregnation layer is 0.01 to 1.0 μm.

Further, when the average particle diameter of the organic fine particles (B) is D _B , the thickness T of the D _B with respect to the diffusion layer satisfies the following formula (B): D _B <T (B).

Further, the present invention is also a method for producing an anti-glare film, which is used for producing an anti-glare having a light-transmitting substrate and a diffusion layer having at least one surface of the light-transmitting substrate and having a concave-convex shape on its surface. A film comprising: a radiation curable adhesive containing fine particles (A) and a (meth) acrylate monomer as an essential component on 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 50% or more of the fine particles (A) in the diffusion layer are formed to connect the centers of the centers with respect to the light-transmitting group. An aggregate formed by agglomerating the surface of the material at an oblique angle.

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

The invention is described in detail below.

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 concavo-convex shape on its surface.

The light-transmitting substrate preferably has 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, cellulose diacetate, and cellulose acetate butyrate. , polyamine, polyimine, polyether oxime, polyfluorene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate A thermoplastic resin such as a polyurethane or a cyclic polyene is preferably a polyester (polyethylene terephthalate or polyethylene naphthalate) or a cellulose triacetate.

The light-transmitting substrate is preferably used as a film body having flexibility, and a plate of the thermoplastic resin or a plate-like body of a glass plate may be used depending on the aspect of the hardenability.

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-shaped body, the thickness may exceed the thickness.

Further, when the light-transmitting substrate is formed with an antiglare layer thereon, in order to improve adhesion, in addition to physical treatment such as corona discharge treatment, plasma treatment, saponification treatment, or oxidation treatment, a fixing agent may be previously prepared. Coating of an anchoring agent or a coating known as a primer.

In the anti-glare film of the present invention, the diffusion layer is applied to the light-transmitting layer containing a fine particle (A) and a radiation-curable adhesive containing a (meth) acrylate monomer as an essential component. At least one surface of the substrate is dried to form a coating film, and the coating film is cured.

In the present specification, the term "monomer" includes all molecules which form a polymer film for free radiation hardening and which can constitute a constituent unit of the basic structure of the polymer film. That is, if the oligomer or prepolymer is a basic unit of the cured film, an oligomer or a prepolymer is also included.

In the present invention, the monomer is preferably a smaller one having a weight average molecular weight of 5,000 or less.

Further, in the present invention, the diffusion layer is a cured coating layer unless otherwise specified.

The fine particles (A) have microparticles having an internal diffusion function and a function of forming a convex portion on the surface of the diffusion layer.

Fig. 1 is a cross-sectional view schematically showing a state of an aggregate in the above diffusion layer.

As shown in FIG. 1, the anti-glare film 10 of the present invention is formed in a diffusion layer 12 formed on at least one surface of a light-transmitting substrate 11, and an agglomerate in which two fine particles (A) 13 are aggregated is formed. The two fine particles (A) 13 forming the aggregate are agglomerated so that the straight lines connecting the centers of the ones are inclined at an oblique angle with respect to the surface of the light-transmitting substrate 11.

Since the diffusion layer has such agglomerates, the antiglare film of the present invention is excellent in antiglare property, and can sufficiently suppress the occurrence of fading, and can further preferably prevent the occurrence of flicker.

In the anti-glare film of the present invention, the fine particles (A) in the diffusion layer are formed into two aggregates which are formed by aggregating a straight line connecting the centers of the respective layers at an oblique angle with respect to the surface of the light-transmitting substrate.

The above-mentioned "straight line connecting the centers of the centers" means a center of a shape drawn by a cross section of the two fine particles (A) constituting the agglomerate in a cross section in which the diffusion layer of the anti-glare film of the present invention is cut along the thickness direction thereof. Straight line. The above-mentioned "center of the shape depicted by the cross section" means that the shape of the cross section is generally a circle, and therefore refers to the center of the circle. When the shape depicted by the cross section is a circle, it means the center of gravity of the cross section.

Further, it is preferable that the two microparticles (A) constituting the agglomerate are connected to each other at a center line and have an inclination angle of 20 to 70° with respect to the surface of the light-transmitting substrate. If it is less than 20°, the antiglare film of the present invention is inferior in antiglare property, and the aggregate contained in the diffusion layer reflects external light to cause fading. On the other hand, when it exceeds 70°, the convex portion formed on the surface of the diffusion layer at the position corresponding to the aggregate may become excessively large, and the antiglare film of the present invention may cause fading and flicker. A more preferable lower limit of the above inclination angle is 30°, and a more preferable upper limit is 60°. When the above inclination angle is within the above range, the balance between the antiglare property, the fading resistance, and the anti-flicking property is extremely excellent.

In the present specification, when the inclination angle is less than 20°, it is considered that two fine particles (A) are aggregated in parallel with respect to the surface of the light-transmitting substrate, and when the inclination angle exceeds 70°, two are regarded as two. The fine particles (A) are vertically aggregated with respect to the surface of the light-transmitting substrate.

In the antiglare film of the present invention, 50% or more of the fine particles (A) in the diffusion layer form the aggregate.

Here, the above-mentioned "50% or more of the above-described aggregates" means that when the microparticles (A) are randomly observed in the cross section of the diffusion layer by a microscope such as SEM or a transmission type or a reflection type optical microscope, 10 or more fine particles ( A) The above agglomerates are formed.

When the fine particles (A) forming the agglomerates are less than 50%, the antiglare property of the antiglare film of the present invention is insufficient, or the occurrence of fading or flicker cannot be sufficiently suppressed. A preferred lower limit of the ratio of the fine particles (A) forming the agglomerates is 65%, and a lower limit is 80%. When the lower limit of the ratio of the fine particles (A) forming the agglomerate is 65%, the anti-glare property and the anti-fading property are more preferable, and when the lower limit of the above ratio is 80%, sufficient anti-glare property and contrast can be obtained.

Further, the fine particles (A) in which the aggregates are not formed in the diffusion layer are less than 50%. In other words, in the above-mentioned diffusion layer, the number of the single-particle fine particles (A) and the two fine particles (A) are condensed perpendicularly or in parallel with respect to the surface of the light-transmitting substrate. The total number of the fine particles (A) of the aggregate and the number of the fine particles (A) constituting the aggregate of the three or more fine particles (A) are less than 10 when randomly measuring 20 fine particles (A). One.

Such fine particles (A) are preferably particles which are not swollen by the radiation curable adhesive and/or solvent in the coating liquid.

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 include slight swelling. In the case of the above-mentioned diffusion layer, the fine layer (A) forms the same impregnation layer as the organic fine particles (B) described later, but the average thickness of the impregnation layer is smaller than that of the organic fine particles (B). The impregnated layer formed in the layer was less than 0.1 μm.

The determination as to whether or not the fine particles (A) in the diffusion layer form an impregnation layer can be performed, for example, by observing a cross section of the fine particles (A) of the diffusion layer by a microscope (SEM or the like).

In the following description, the fine particles (A) in the diffusion layer are also referred to as "fine particles (A2)".

Examples of the fine particles (A) that are not swollen by the radiation-curable adhesive and/or the solvent include inorganic particles such as cerium oxide fine particles, or polystyrene resin, melamine resin, polyester resin, acrylic resin, and the like. An organic resin such as an olefin resin or a copolymer such as these copolymers is used to increase the degree of crosslinking. These fine particles (A) may be used singly or in combination of two or more.

Among them, it is preferable to easily control the refractive index or the particle diameter of the organic fine particles, and it is easy to set the refractive index difference with the radiation-curable adhesive (normally, the refractive index of the radiation-curable adhesive is about 1.48 to 1.54). It is preferred to use melamine microparticles, polystyrene microparticles, and/or acrylic acid-styrene copolymer microparticles. In addition, the case where the fine particles (A) are organic fine particles will be described below. In the present specification, the term "resin" also includes the concept of a resin component such as a monomer or an oligomer.

Here, when the organic fine particles composed of an acrylic resin, a polystyrene resin, and an acrylic-styrene copolymer are produced by a generally known production method, an acrylic-styrene copolymer resin is used as a material. Further, when the fine particles are of a core-shell type, there are acrylic fine particles in which fine particles of fine particles composed of an acrylic resin are used for the core, or microparticles composed of a styrene resin are used in the opposite core. Therefore, in the present specification, the distinction between the acrylic fine particles, the polystyrene fine particles, and the acrylic-styrene copolymerized fine particles is determined by which resin (for example, the refractive index) of the fine particles is 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. If the refractive index of the fine particles is 1.50 or more and less than 1.59, it can be regarded as an acrylic-styrene copolymer fine particle, and if the refractive index of the fine particles is 1.59 or more, It can be regarded as styrene microparticles.

In addition, in the case where there are "high crosslinking" and "low crosslinking" for the fine particles, the "high crosslinking" and "low crosslinking" are defined as follows.

Preparation of the following coating liquid: a mixture of radiation hardening type binder (pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA) and polymethyl methacrylate (PMMA) (mass ratio) ; PETA / DPHA / PMMA = 86 / 5 / 9)) 100 parts by mass, blended with 190 parts by mass of a mixture of toluene and methyl isobutyl ketone (mass ratio of 8:2).

The fine particles were immersed in the obtained coating liquid for 24 hours, and it was found that the pulverized fine particles were defined as "low crosslinking", and the fine particles which were not found to be swelled were defined as "high crosslinking".

Here, as described above, in order to provide the antiglare film with sufficient antiglare performance, it is preferable to form a large convex portion on the surface of the diffusion layer. For example, if the diffusion layer contains fine particles having a large particle diameter, it is easy to easily A large convex portion is formed on the surface of the diffusion layer. However, when the diffusion layer contains fine particles having a large particle size, the surface thereof becomes rough (the image of the image of the display to which the anti-glare film of the present invention is applied lacks the density of the image, and the image quality is lacking. The density is reduced and the image quality is lowered. Further, in order to prevent the fine particles from falling off and the like, it is necessary to thicken the diffusion layer. Therefore, the formed anti-glare film is curled or cracked due to curing shrinkage of the binder component at the time of formation of the diffusion layer.

The inventors of the present invention have focused on the relationship between the antiglare property of such a diffusion layer and the size of the contained microparticles, and as a result of the investigation, by selecting relatively small particles as the microparticles contained in the diffusion layer, and The fine particles are in a specific agglomerated form in the diffusion layer, and the problem of selecting the above-mentioned large-sized fine particles can be avoided, and an anti-glare film capable of exhibiting sufficient antiglare performance can be obtained.

In other words, in the present invention, the fine particles (A) contained in the diffusion layer are selected to have smaller particle diameters than the fine particles previously added to exhibit sufficient antiglare performance.

The average particle diameter of the fine particles (A) is specifically preferably in the range of 0.5 to 10.0 μm. If it is less than 0.5 μm, the above-mentioned aggregates cannot be formed at a specific ratio, and the antiglare performance of the antiglare film of the present invention is insufficient. On the other hand, when it exceeds 10.0 μm, the uneven shape formed on the surface of the diffusion layer becomes large, and the anti-glare film of the present invention causes fading or flicker. A more preferred lower limit is 1.0 μm, and a more preferred upper limit is 8.0 μm.

Further, the average particle diameter of the fine particles (A) is the particle diameter in the coating film, and if the shape of each of the fine particles contained is a single particle, it means an arithmetic mean value, and if it has a wide particle size distribution The amorphous microparticles refer to the particle diameter of the microparticles which are most present according to the particle size distribution measurement. Further, as for the particle diameter, in the state of only the fine particles, it can be measured by a Coulter counter method or the like. However, the fine particles present in the coating film exhibit a particle diameter different from that of the powder state due to swelling or the like. Therefore, the average particle diameter of the fine particles (A) in the diffusion layer of the antiglare film of the present invention is preferably. It was measured by photographing by a transmission optical microscope or by taking a SEM photograph of a cross section.

In the anti-glare film of the present invention, when the average particle diameter of the fine particles (A) forming the agglomerates is D _A , the agglomerates are formed according to the positional relationship of the inclination angles of the two fine particles (A). When the inclination angle between the line connecting the centers of the fine particles (A) and the surface of the light-transmitting substrate is defined as θ, the height in the thickness direction of the aggregates in which the two fine particles (A) are adjacent is:

1/2D _A + D _A sin θ + 1/2 D _A = D _A (1 + sin θ).

At this time, if an approximate value of sin20°≒0.34 and sin70°≒0.94 is used, the height in the thickness direction of the aggregate at a tilt angle of 20° is (1.34×D _A ), and the thickness direction of the aggregate at a tilt angle of 70°. Since the height is (1.94 × D _A ), it is preferable that the positional relationship between the above D _A and the thickness T of the diffusion layer satisfies the following formula (A):

(1.34 × D _A ) <T < (1.94 × D _A ) (A).

The agglomerate can be preferably formed by satisfying the relationship of the average particle diameter D _{A of the} agglomerated fine particles (A) and the thickness T of the diffusion layer to the above formula (A).

In other words, when the thickness of the diffusion layer is 1.34 times or less of the average particle diameter, the inclination angle between the straight line connecting the centers of the two fine particles (A) constituting the aggregate and the surface of the light-transmitting substrate is too small. When the ratio is 1.94 times or more, the inclination angle between the straight line connecting the centers of the two fine particles (A) constituting the aggregate and the surface of the light-transmitting substrate becomes excessive.

A more preferable range is based on the positional relationship of the inclination angles of the above two fine particles (A), and the following formula (A') of an approximate value of sin 30 ° ≒ 0.50 and sin 60 ° ≒ 0.87 is used:

(1.50 × D _A ) < T < (1.87 × D _A ) (A').

Further, the thickness T of the diffusion layer means an average value of the thickness of the diffusion layer measured from the SEM photograph of the cross section of the anti-glare film.

Further, unless otherwise specified, the above D _A represents the average particle diameter of the fine particles (A) in the diffusion layer after curing.

In the anti-glare film of the present invention, as the fine particles (A), for example, an anti-glare film is prepared by using a coating liquid of organic fine particles having different degrees of crosslinking, and an organic fine particle having a uniform degree of impregnation can be selected and used. .

The content of the fine particles (A) in the coating liquid is not particularly limited, and is preferably 0.5 to 30 parts by mass based on 100 parts by mass of the radiation-curable adhesive described later. If it is less than 0.5 part by mass, the antiglare property of the antiglare film of the present invention is insufficient, and flicker is likely to occur. On the other hand, when it exceeds 30 parts by mass, the contrast of the image display layer using the anti-glare film of the present invention is lowered. A more preferred lower limit of the content of the fine particles (A) is 1 part by mass, and a more preferred upper limit is 20 parts by mass. By being within this range, the above effects can be obtained more surely.

The coating liquid preferably further contains organic fine particles (B).

The difference in refractive index between the organic fine particles (B) and the binder is preferably less than 0.04.

The organic fine particles (B) are mainly formed by forming a convex portion on the surface of the diffusion layer at a position corresponding to the organic fine particles (B), and can be formed in the formed diffusion layer by containing such organic fine particles (B). Smooth bumps with both anti-glare and contrast.

The material constituting the organic fine particles (B) is preferably swelled by a radiation-curable adhesive and/or a solvent to be described later, and specific examples thereof include a polyoxyxylene resin, a polyester resin, and a styrene resin. An acrylic resin, an olefin resin, or a copolymer of the above, wherein an acrylic resin is preferably used, and in the case of producing fine particles, a crosslinked acrylic acid of a type which changes the degree of crosslinking such as a crosslinking density is preferably used. Resin. In the present specification, the term "resin" also includes the concept of a resin component such as a reactive or non-reactive polymer, a monomer, or an oligomer.

Here, the organic fine particles composed of an acrylic resin, a styrene resin, and an acrylic-styrene copolymer are all made of an acrylic-styrene copolymer resin as a material when produced by a generally known production method. In addition, when the organic fine particles (B) are core-shell type fine particles, there are styrene fine particles in which fine particles of acrylic particles are used for the core, or acrylic fine particles in which fine particles composed of a styrene resin are used in the opposite core. Therefore, in the present specification, the distinction between the acrylic fine particles, the styrene fine particles, and the acrylic-styrene copolymerized fine particles is determined by which resin (for example, the refractive index) of the fine particles is 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. If the refractive index of the fine particles is 1.50 or more and less than 1.59, it can be regarded as an acrylic-styrene copolymer fine particle, and if the refractive index of the fine particles is 1.59 or more, It can be considered as styrene microparticles.

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

The above acrylic monomer is particularly preferably a crosslinked acrylic resin obtained by using methyl methacrylate. In addition, since the thickness of the impregnation layer to be described later can be controlled by adjusting the degree of swelling by the radiation-curable adhesive and/or solvent described later, it is preferable to change the impregnation amount of the radiation-curable adhesive to a preferable range. The extent of cross-linking.

The average particle diameter of the organic fine particles (B) is not particularly limited, and may be equivalent to the average particle diameter of the fine particles (A). However, it is preferable that the average particle diameter of the organic fine particles (B) in the diffusion layer is larger than the fine particles (A2) in the diffusion layer. When the average particle diameter of the organic fine particles (B) in the diffusion layer is equal to or less than the average particle diameter of the fine particles (A2) in the diffusion layer, the effect of adding the fine particles (A) is hardly obtained.

Further preferably, when the average particle diameter of the organic fine particles (B) in the diffusion layer is D _B , the thickness T of the D _B with respect to the diffusion layer satisfies the following formula (B):

D _B <T (B).

When the average particle diameter D _{B of} the organic fine particles (B) does not satisfy the above formula (B), that is, when the average particle diameter D _B of the organic fine particles (B) is equal to or greater than the thickness T of the diffusion layer, the organic The irregularities formed on the surface of the diffusion layer by the fine particles (B) become large, and the anti-glare film of the present invention is inferior in hard coatability or causes a decrease in contrast when applied to an image display device.

In the antiglare film of the present invention, it is preferred that the organic fine particles (B) in the diffusion layer have an impregnation layer impregnated with a radiation curable adhesive described later. In the following description, the organic fine particles (B) in the diffusion layer, which is the organic fine particles (B) in which the impregnation layer is formed, are also referred to as "organic fine particles (B2)". The cured product of the radiation-curable adhesive (hereinafter also referred to as a binder resin) of the organic fine particles (B2) and the diffusion layer is excellent in adhesion by the impregnation layer. Further, since the impregnated layer in the organic fine particles (B2) is formed in a state in which the radiation-curable adhesive is mixed with the material constituting the organic fine particles (B2), the refractive index of the impregnated layer becomes the refractive index of the radiation-curable adhesive. The refractive index between the refractive index of the organic fine particles (B) and the reflection of the transmitted light of the above-mentioned diffusion layer at the interface between the organic fine particles (B2) (the impregnated layer) and the binder resin can be preferably reduced. Further, at the same time, the impregnation layer has a moderate layer thickness, and the center of the organic fine particles (B2) maintains the refractive index of the initial organic fine particles (B), so that internal diffusion does not decrease, and flicker can be preferably prevented.

Further, as described later, the impregnation layer is a layer formed by swelling the organic fine particles (B) by the radiation-curable adhesive and/or a solvent. Therefore, the organic fine particles (B2) are extremely flexible fine particles. Therefore, the shape of the convex portion formed at the position of the surface of the diffusion layer corresponding to the organic fine particles (B2) can be made gentle. Again, this aspect is described in more detail below.

The impregnation layer is a layer formed by impregnating a center of the organic fine particles (B2) in the diffusion layer with a radiation-curable adhesive to the center thereof. Further, the impregnated layer is a layer of a low-molecular-weight component of a radiation-curable adhesive, that is, a layer mainly composed of a monomer, and a polymer or oligomer of a polymer of a radiation-curable adhesive having a high molecular weight component. Hard to irrigate. However, even oligomers or polymers are relatively small in molecular weight or impregnated together when impregnating the monomers.

The impregnation layer can be discriminated by, for example, microscopic observation (SEM or the like) of the cross section of the organic fine particles (B2) in the diffusion layer.

Further, the radiation-curable adhesive impregnated in the impregnated layer may be all components of the impregnation, or may be one of the components of the impregnation.

The above impregnated layer preferably has an average thickness of 0.01 to 1.0 μm. If it is less than 0.01 μm, the effect of forming the above-mentioned impregnation layer cannot be sufficiently obtained. When the thickness exceeds 1.0 μm, the internal diffusion function of the organic fine particles (B2) cannot be sufficiently exhibited, and the anti-flicking effect cannot be sufficiently 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. The above effects can be further exerted by being within this range. Further, from the viewpoint that the diameter of the central portion of the impregnation layer is not formed in the organic fine particles (B2) to ensure the internal diffusion function and to prevent flicker, the wavelength of light is preferably equal to or higher than the wavelength of light.

Further, the average thickness of the above-mentioned impregnated layer means the average value of the thickness of the impregnated layer of the organic fine particles (B2) observed by the SEM photograph of the cross section of the antiglare film. Specifically, it is possible to observe and photograph any five parts of the cross section of the diffusion layer in which one or more microparticles having an impregnation layer are present in the cross section of the diffusion layer by SEM, and then measure two pieces of one microparticle. The thickness of the impregnated layer was determined as the average value at the measured value of 10. The measurement of the thickness of the impregnation layer is carried out by selecting a portion where the boundary between the binder resin and the fine particles around the two microparticles is relatively clear and the maximum impregnation is performed.

Here, the organic fine particles usually have a crosslinked structure, and the degree of swelling caused by the radiation-curable adhesive or solvent differs depending on the degree of crosslinking. Generally, if the degree of crosslinking becomes high, the degree of swelling becomes low, and cross-linking is obtained. When the degree is low, the degree of swelling becomes high. Therefore, for example, when the material constituting the organic fine particles (B) is the crosslinked acrylic resin, the thickness of the impregnation layer of the organic fine particles (B2) can be controlled by appropriately adjusting the degree of crosslinking of the crosslinked acrylic resin. Need range. Further, from the viewpoint of antireflection performance and anti-flicking, it is more preferable that the degree of crosslinking is increased as the organic fine particles (B2) are at the center portion, and it is preferable to be in comparison with the impregnation layer of the organic fine particles (B2). The thickness, the inner side is the degree of cross-linking of non-impregnation, and the lower the degree of cross-linking of the surface. The same applies to the above fine particles (A).

Further, when the average particle diameter of the organic fine particles (B) is D _B 1 and the average particle diameter of the organic fine particles (B2) in the diffusion layer is D _B 2 , the D _B 1 and D _{B are} preferably used. 2 satisfies the following formula (2):

0.01 μm < D _B 2-D _B 1 < 1.0 μm (2).

In the above formula (2), when "D _B 2-D _B 1" is 0.01 μm or less, the thickness of the impregnation layer is too thin, and the effect of forming the impregnation layer cannot be obtained. When "D _B 2-D _B 1" is 1.0 μm or more, the unevenness formed on the surface is excessively large, and the internal diffusion function cannot be sufficiently exhibited, and the anti-flicking effect cannot be sufficiently obtained. A more preferable lower limit of the above "D _B 2-D _B 1" is 0.1 μm, and a more preferable upper limit is 0.5 μm. By setting "D _B 2-D _B 1" to this range, the above effects can be further exerted.

Further, in the anti-glare film of the present invention, when the organic fine particles (B) have an impregnation layer in the diffusion layer, the organic fine particles (B) are coated with organic fine particles having different degrees of crosslinking, for example. The liquid is made into an anti-glare film, and it is preferable to use organic fine particles having the same degree of impregnation as the preferred one.

Further, in the anti-glare film of the present invention, when the organic fine particles (B) in the diffusion layer form an impregnation layer, the average particle diameters of the fine particles (A) and the organic fine particles (B) are respectively set to D _A 1 and D _B 1, when the average particle diameters of the fine particles (A2) and the organic fine particles (B2) in the diffusion layer are respectively D _A 2 and D _B 2 , the above D _A 1 , D _B 1 , D _A 2 and D _B 2 satisfies the following formula (3): 1.0 μm>D _B 2-D _B 1>D _A 2-D _A 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 binder or the like to the particles which contribute to the internal diffusion can be suppressed, and thus the internal diffusion can be easily maintained. Further, the reflection of the surface of the particles in the diffusion layer can be reduced, so that the fading of the anti-glare film of the present invention and the anti-flicking can be more reliably prevented.

Further, it is preferable that the organic fine particles (B) do not aggregate in the thickness direction (longitudinal direction) of the diffusion layer in the diffusion layer. When the organic fine particles (B) in the diffusion layer are aggregated as in the thickness direction of the diffusion layer, the surface of the diffusion layer at a position corresponding to the aggregated organic fine particles (B) may be formed to be large. The convex portion produces fading or flicker in the anti-glare film of the present invention. Further, the aggregation of the organic fine particles (B) in the diffusion layer can be preferably prevented by, for example, containing a layered inorganic compound described later. Further, when the aggregation of the organic fine particles (B) is perpendicular to the thickness direction of the diffusion layer (lateral direction), the above problem is less likely to occur than the aggregation in the longitudinal direction, but if the agglomerates become excessively large, Since the same problem also occurs, it is preferable to add a layered inorganic compound in the same manner as in the case of aggregation in the longitudinal direction.

The content of the organic fine particles (B) in the coating liquid is not particularly limited, and is preferably 0.5 to 30 parts by mass based on 100 parts by mass of the radiation-curable adhesive described later. If it 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 property of the antiglare film of the present invention becomes insufficient. On the other hand, when the amount is more than 30 parts by mass, the organic fine particles (B) are likely to aggregate in the coating liquid, and the diffusion layer tends to aggregate in the longitudinal or transverse direction, and forms a larger surface on the surface of the diffusion layer. Fading or flickering. A more preferred lower limit of the content of the organic 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 obtained more surely.

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

By containing the above (meth) acrylate monomer as an essential component, the above-mentioned diffusion layer can be contained in the state in which the above-mentioned diffusion layer is not damaged by the hard coat property.

The above-mentioned radiation-curable adhesive is preferably one in which the organic fine particles (B) are swollen, and preferably, the transparent radiation-curable resin is cured by ultraviolet rays or electron beams. In the present specification, the term "(meth)acrylate" means methacrylate and acrylate.

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, neopentyl alcohol tri (meth) acrylate, neopentyl alcohol penta (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, ACE modified bis(meth) acrylate, isomeric cyanuric acid EO modified tri(meth) acrylate, trimethylolpropane PO modified tri(meth) acrylate, trihydroxyl Methylpropane EO modified tri(meth)acrylate, bis(trimethylolpropane)tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol A reaction product of a polyfunctional compound such as di(meth)acrylate or neopentyl glycol di(meth)acrylate with (meth)acrylate or the like (for example, a poly(meth)acrylate of a polyhydric alcohol).

Further, an amine (meth) acrylate or a polyester (meth) acrylate having two or more unsaturated bonds may also be mentioned.

The above-mentioned free radiation hardening type resin may, in addition to the above compounds, 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 resin, or a snail. An acetalacetal resin, a polybutadiene resin, a polythiol polyene resin or the like is used as the above-mentioned free radiation hardening type resin.

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

Specific examples of the photopolymerization initiator include acetophenones, benzophenones, Michelin benzoyl benzoate, α-amyloxime ester, and 9- Oxygen and sulfur (thioxanthon), propiophenone, diphenylethylenedione, benzoin, fluorenylphosphine oxide. Further, it is preferred to use a photosensitizer in combination, and specific examples thereof include n-butylamine, triethylamine, and poly-n-butylphosphine.

When the ultraviolet curable resin is a resin having a radical polymerizable unsaturated group, the photopolymerization initiator is preferably used singly or in combination: acetophenone, benzophenone, 9-oxosulfur Class, 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 used singly or in combination: an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic sulfonium salt, Metal aromatic compounds, benzoin sulfonate, and the like.

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

The above-mentioned free-radiation-curable resin may be used in combination with a solvent-drying resin (a resin obtained by drying a solvent which is added by adjusting a solid component, such as a thermoplastic resin to form a film). In this case, the solvent-drying type resin is mainly used as an additive, and an free radiation curing type resin is mainly used. 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, those generally 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. A resin, a polyester resin, a polyamide resin, a cellulose derivative, a polyoxyn resin, a rubber or an elastomer.

The 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.

According to a preferred embodiment of the present invention, when the material of the light-transmitting substrate is a cellulose resin such as cellulose triacetate "TAC", a specific example of the thermoplastic resin is, for example, a cellulose resin. Nitrocellulose, cellulose acetate, cellulose acetate propionate, ethyl hydroxyethyl cellulose, and the like. By using the above cellulose-based resin, the adhesion and transparency of the light-transmitting substrate and the diffusion layer 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 alkyd. Resin, melamine-urea co-condensation resin, enamel resin, polydecane resin, and 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.

When in the antiglare film of the present invention is preferably in the difference in refractive index, respectively fine particles (A) and organic fine particles (B) The refractive index of the set of the radiation-curable adhesive △ △ _A and _B, the above △ _A and Δ _B satisfy the following formula (1): |Δ _B |<|Δ _A | (1).

By satisfying the above formula (1), it is possible to obtain an internal diffusion having a small diffusion angle of the fine particles (B) and an internal diffusion having a large diffusion angle of the fine particles (A) without flicker and excellent uniformity of screen brightness. Anti-glare film.

Further, the method for measuring the refractive index of the radiation-curable adhesive, the fine particles (A) and the organic fine particles (B) may be any method, for example, by the Becke method, the minimum declination method, the off-angle analysis, and the modality. The measurement is performed by a mode-line method, an ellipsometry method, or the like.

Further, when the radiation curable adhesive contains the (meth) acrylate and other resins, the refractive index of the radiation curable adhesive refers to the refractive index of all the resin components contained in the fine particles.

A preferred method for measuring the refractive index is a radiation curable adhesive, and a method in which only the adhesive portion is removed from the cured film and measured by the Becke method is exemplified. Alternatively, the phase difference can be measured by using a transmission type phase shift laser micro-interference measuring device PLM-OPT manufactured by NTT Advanced Technology, and 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 previously.

The coating liquid preferably further contains a solvent.

The solvent is not particularly limited, and examples thereof include water, an alcohol (for example, methanol, ethanol, isopropanol, butanol, and benzyl alcohol), and a ketone (for example, acetone, methyl ethyl ketone, and methyl isobutyl ketone. 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 (such as dichloromethane, chloroform, carbon tetrachloride), aromatic hydrocarbons (such as benzene, toluene, xylene), decylamine (such as dimethylformamide, dimethyl Ethyl acetamide, N-methylpyrrolidone), ether (e.g., diethyl ether, dioxane, tetrahydrofuran), ether alcohol (e.g., 1-methoxy-2-propanol), and the like.

In the anti-glare film of the present invention, the radiation-curable adhesive and the solvent may be selected such that the organic fine particles (B) are swollen, and the organic fine particles (B) may be selected by using only one of them. The nature of swelling.

In addition, as for the formation of the impregnation layer of the organic fine particles (B), there is a solvent having the property of swelling the organic fine particles (B), and the degree of swelling of the radiation-curable adhesive can be more sure. It is more preferable that at least the above solvent has a property of swelling the organic fine particles (B). It is presumed that the above-mentioned solvent acts on the organic fine particles (B) to swell the organic fine particles (B), and then impregnates the low molecular weight component contained in the radiation curable adhesive.

In the anti-glare film of the present invention, the combination of the radiation-curable adhesive and the solvent is preferably a combination of a (meth) acrylate monomer which is small in molecular weight and which is easily impregnated as a radiation-curable adhesive, and a solvent. A ketone or an ester system having a strong property of swelling the above organic fine particles (B).

Further, by adjusting the degree of swelling of the organic fine particles (B) 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 or the interference fringe generated at the interface is prevented. It is preferred 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. It is more preferable if the solvent for swelling the organic fine particles (B) is common to the solvent impregnated with the TAC substrate. That is, when the solvent for the TAC substrate is substantially the same as the solvent used to prepare the organic fine particles (B) having the impregnated layer in advance, the balance of the compound contained in the coating liquid becomes a very stable state, and when the antiglare film is processed for a long time. It can also be made into a stable coating and excellent coating liquid.

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.

Further, the coating liquid preferably contains a layered inorganic compound. The reason is that the formed diffusion layer contains the layered inorganic compound, and the hard coat property, the curl resistance, the ultraviolet ray resistance, the crack resistance, and the like of the diffusion layer can be improved. Further, an aggregate of the above fine particles (A) can be preferably formed. Further, when the organic fine particles (B) are contained, the fine particles (A) are preferably aggregated, and aggregation of the fine particles (A) and the organic fine particles (B) can be prevented.

In order to maintain the transparency of the antiglare film of the present invention, the layered inorganic compound preferably has a particle diameter D50 (laser diffraction method) of 0.3 to 5.0 μm, more preferably 0.5 to 3.0 μm. Since the layered inorganic compound is a plate-like particle, the particle diameter is D50. For example, when talc having a D50 of 0.6 μm is used, if the cross-sectional SEM observation of the diffusion layer is performed, it is found that the majority of the particles have a long diameter of about 0.6 μm. .

The layered inorganic compound is not particularly limited, and examples thereof include montmorillonite, beidellite, nontronite, saponite, hectorite, smectite, strontite, vermiculite, and halloysite. Kaolin, Ande stone, Dick stone, talc, pyrophyllite, mica, pearl mica, muscovite, phlogopite, mica, mica, serpentine, chlorite, cookeite, Green mudstone group (nantite) and so on. The layered inorganic fine particles may be natural or synthetic.

The layered inorganic compound is preferably an inorganic compound containing Si, Al, Mg or O elements, and a compound containing such an element, preferably talc.

When the talc is contained as the layered inorganic compound, for example, when the crosslinked acrylic particles are used as the organic fine particles (B) and styrene is used as the fine particles (A), the prevention of the fine particles (A) in the diffusion layer can be preferably controlled. Formation of aggregates, aggregation of organic fine particles (B) in the diffusion layer, and aggregation of fine particles (A) and organic fine particles (B). As a result, the anti-glare property, the anti-fading property, and the anti-flicking property of the obtained anti-glare film can be achieved at a high level.

It is speculated that it is caused by the above-mentioned talc being a substance having high lipophilicity. That is, it is presumed that the fine particles (A) (styrene) have lipophilic properties, and the organic fine particles (B) (crosslinked acrylic resin) have various properties of hydrophilicity, and the talc having high lipophilicity adjusts the aggregation of the two fine particles.

In addition, the above-mentioned layered inorganic compound means an inorganic compound which is a layered structure, and also includes a needle-like or fibrous shape in a cross-sectional microscope observation.

Further, in the copolymerized fine particles of acrylic acid-styrene, it is easy to impart moderate hydrophilicity or lipophilicity by changing the ratio of the highly hydrophilic acrylic component to the lipophilic styrene component, so that the layered layer can be easily used. The cohesive properties of inorganic compounds.

When the coating film contains the layered inorganic compound, the content thereof is preferably adjusted to be more than 1 part by mass and 40 parts by mass or less based on 100 parts by mass of the radiation curable adhesive. When the amount is 1 part by mass or less, the effect of containing the layered inorganic compound cannot be sufficiently obtained, and if it exceeds 40 parts by mass, the viscosity of the coating liquid becomes too high, so that the surface of the antiglare film of the present invention cannot be obtained smoothly. Sex, but the optical properties are poor, or the viscosity of the coating liquid becomes too high to be coated. A more preferred lower limit of the content of the layered inorganic compound is 2 parts by mass, and a more preferred upper limit is 30 parts by mass. By this range, the preferable aggregation and inclination angle of the above fine particles can be obtained more surely.

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 beads 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 Meyer 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. The dry film thickness is preferably from about 1 to 20 μm, more preferably from 2 to 15 μm. The reason is that if the film thickness is less than 1 μm, the hard coat property is inferior, and if it exceeds 20 μm, curling or cracking easily occurs.

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 five or more points, and the average value thereof was determined.

Here, in the antiglare film of the present invention, the fine particles (A) in the diffusion layer form the two aggregates.

Such agglomerates can be formed, for example, by the following method when the coating liquid contains a layered inorganic compound.

In other words, first, the type and amount of the layered inorganic compound (for example, talc) suitable for agglomerating the two fine particles (A) are determined in advance based on the degree of hydrophilicity/hydrophobicity of the fine particles (A).

Then, the layered inorganic compound to be determined is mixed with the fine particles (A) and the like in the coating liquid, and the coating film formed using the coating liquid is in the above film thickness range.

The reason why the agglomerates are formed by such a method is still unclear, but it is presumed to be affected by the difference in lipophilicity or surface tension between the lower translucent substrate and the upper air layer in the coating film.

Further, as described above, the organic fine particles (B) having the impregnated layer are preferably prepared by swelling the organic fine particles (B) by the radiation-curable adhesive and/or solvent to impregnate the organic fine particles (B). The radiation-curable adhesive is used to form an impregnation layer; and the preparation of the organic fine particles (B) having the impregnation layer may be carried out in the coating liquid or in a 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. When curing by ultraviolet rays, it is preferred to use ultraviolet rays in a wavelength region of 190 to 380 nm. The curing of the ultraviolet rays can be performed, for example, by 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 fluorescent lamp, or the like. Specific examples of the electron beam source include various electron beam accelerators such as a Cockcroft-Walton type, a Van de Graaff type, a resonant transformer type, an insulated nuclear transformer type, a linear type, a high frequency high voltage (dynamitron type), and a high frequency type.

In the antiglare film of the present invention, the diffusion layer has an uneven shape on the surface.

It is preferable that the uneven shape on the surface of the diffusion layer has a convex portion (hereinafter also referred to as a convex portion (A)) at a position corresponding to the aggregate of the fine particles (A) in the diffusion layer.

Since the convex portion (A) formed on the surface of the diffusion layer is formed by the aggregate, the particle diameter can be further improved, so that sufficient anti-glare performance can be exhibited, and since the particles are obliquely present, they are parallel to each other. The area of the particles irradiated by the external light is smaller, and the reflection at the interface with the binder can be further reduced, so that the occurrence of fading can be preferably prevented. Further, since it is not necessary to thicken the thickness of the diffusion layer, it is possible to preferably prevent the occurrence of cracking of the antiglare film of the present invention or cracking of the diffusion layer.

Further, when the diffusion layer contains the organic fine particles (B) having the impregnation layer, the convex portion formed at a position corresponding to the organic fine particles (B) of the diffusion layer (hereinafter also referred to as a convex portion (hereinafter also referred to as a convex portion) The height of B)) is lower than the surface of the diffusion layer (C) containing the organic fine particles (C) which completely satisfy the following requirements (1), (2) and (3), corresponding to the above organic fine particles (C) The height of the convex portion (hereinafter also referred to as convex portion (C)) at the position.

Necessary condition (1): A diffusion layer (C) is formed under the same conditions as the diffusion layer containing the organic fine particles (B) except that the organic fine particles (C) are used instead of the organic fine particles (B); necessary condition (2): diffusion layer The organic fine particles (C) in (C) have the same average particle diameter as the organic fine particles (B) in the diffusion layer; the necessary condition (3): the organic fine particles (C) are not formed with the impregnated layer in the diffusion layer (C) .

The convex portion (B) at the position corresponding to the organic fine particles (B) of the diffusion layer has a lower height and/or average inclination angle than the convex portion (C), and has a gentle shape. The anti-glare film of the present invention having the diffusion layer forming such a convex portion (B) can further improve anti-glare properties and fade resistance.

The reason is considered to be that the organic fine particles (B) in the diffusion layer are very flexible microparticles as compared with the organic fine particles (C). In other words, when the coating film is cured, the radiation-curable adhesive causes hardening and shrinkage, and the surface of the organic fine particles (B) hardens and contracts, compared with the hardening shrinkage of the surface of the organic fine particles (B). The above radiation hardening type bonding amount is small, and thus becomes small. However, since the organic fine particles (B) are very flexible fine particles, the organic fine particles (B) are deformed by the hardening shrinkage of the coating film. As a result, it is estimated that the height and/or the average inclination angle of the formed convex portion (B) is compared with the convex portion (C) formed on the surface of the diffusion layer (C) containing the harder organic fine particles (C). , lower and smoother.

Further, the height of the convex portion is observed by the AFM to observe the surface of the anti-glare film, and the difference between the height of the convex portion existing on the surface and the concave portion between the convex portion adjacent to the convex portion is measured as the height of the convex portion. n (n is 1 to 10). Then, the values of 10 arbitrary heights of the convex portions obtained in this manner are averaged and obtained.

The fine particles (A) in the diffusion layer of the anti-glare film of the present invention form two aggregates at a specific ratio, and the two fine particles (A) of the aggregate are connected to the surface of the light-transmitting substrate. The line of the isocenter is agglomerated in such a manner as to be inclined. Therefore, the anti-glare film of the present invention can form a convex portion formed on the surface thereof at a position corresponding to the aggregate of the fine particles (A) at a moderate height, and is excellent in anti-glare property, and can sufficiently suppress the occurrence of fading. Further, it is possible to preferably prevent the occurrence of flicker. Further, since it is not necessary to thicken the above-mentioned diffusion layer, it is possible to preferably prevent the occurrence of cracking of the antiglare film of the present invention or cracking of the diffusion layer.

Further, when the diffusion layer contains the organic fine particles (B) having the impregnation layer, the anti-glare film of the present invention is excellent in adhesion between the organic fine particles (B) in the diffusion layer and the cured product of the radiation-curable adhesive. By. Furthermore, the antiglare film of the present invention preferably does not produce a turtle in a mandrel test under the condition that the diameter of the mandrel is 10 mm, more preferably 8 mm, and particularly preferably 6 mm. crack.

Further, when the impregnation layer is formed in the organic fine particles (B) in the diffusion layer, the impregnation layer is formed by mixing a radiation-curable adhesive, and therefore the organic fine particles (B) in the diffusion layer (the impregnation layer) The refractive index difference with the cured product of the radiation hardening type binder is reduced, and the reflection at the interface can be more preferably reduced. Further, at the same time, the impregnation layer has a moderate layer thickness, and the center of the organic fine particles (B) maintains the refractive index of the initial organic fine particles (B), so that moderate internal diffusibility can be exhibited, and flicker can be preferably prevented.

Further, the convex portion formed at the position corresponding to the organic fine particles (B) of the diffusion layer can have a low height and a gentle shape. Therefore, the anti-glare property, the anti-fading property, the anti-flicking property, and the like of the anti-glare film of the present invention can be achieved at a higher level.

The method of producing such an anti-glare film of the present invention is also one of the inventions.

That is, the method for producing an anti-glare film of the present invention is 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 its surface. A method of coating a radiation-curable adhesive containing fine particles (A) and a (meth) acrylate monomer as an essential component on 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 50% or more of the fine particles (A) in the diffusion layer are formed so as to connect the centers of the centers with respect to the light-transmitting group. An aggregate formed by agglomerating the surface of the material at an oblique angle.

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

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

In addition, the polarizing plate is one of the inventions, and is a polarizing element. The anti-glare film of the present invention is provided by bonding a light-transmitting substrate or the like to the surface of the polarizing element.

The polarizing element is not particularly limited, and for example, a polyvinyl alcohol film which is dyed by iodine or the like and stretched, 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 saponification treatment, the adhesiveness becomes good, and an antistatic effect can also be obtained.

The present invention is also an image display device in which the anti-glare film or the polarizing plate is provided 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 system includes a transmissive display body and a light source device that illuminates the transmissive display body from the back surface. 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 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 can 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 is sealed with a discharge gas therebetween. When the image display device of the present invention is a PDP, the antiglare film is provided on the surface of the surface glass substrate or the front panel (glass substrate or film substrate).

The other image display device may be an ELD device that vaporizes a zinc sulfide or a diamine substance that emits light after application of a voltage, vaporizes the light-emitting body on a glass substrate, controls the voltage applied to the substrate, and displays the electric signal. An image display device such as a CRT that produces light for human eyes. In this case, the anti-glare film is provided on the outer surface of each of the display devices as described above or on the surface of the front panel.

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

The fine particles (A) in the diffusion layer of the anti-glare film of the present invention form two aggregates at a specific ratio, and the two fine particles (A) of the aggregate are connected to each other with respect to the surface of the light-transmitting substrate. The line of the center is condensed in such a manner as to be inclined. Therefore, the anti-glare film of the present invention can have a convex portion formed on the surface thereof at a position corresponding to the aggregate of the fine particles (A) at a moderate height, and is excellent in anti-glare property, and since the particles are obliquely present, Compared with the case of parallel side by side, the area of the particles irradiated by the external light is smaller, and the reflection at the interface with the adhesive is further reduced, so that the generation of fading can be sufficiently suppressed, and the contrast is high, and it is preferably prevented. The occurrence of flicker, and thus also hard coating. Further, since it is not necessary to thicken the above-mentioned diffusion layer, it is possible to preferably prevent the occurrence of cracking of the antiglare film of the present invention or cracking of the diffusion layer.

The content of the present invention is illustrated by the following examples, but the contents of the present invention are not construed as being limited by the examples.

(Example 1)

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

Then, a mixture of neopentyl alcohol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), and polymethyl methacrylate (PMMA) was used (mass ratio: PETA/DPHA/PMMA=86/ 5/9) (refractive index: 1.51) As a radiation curable adhesive, 1-hydroxycyclohexyl phenyl ketone: Irgacure 184 (manufactured by BASF Corporation) (5 parts by mass based on 100 parts by mass of the binder solid content) was used. The photopolymerization initiator contains 12.0 parts by mass of highly crosslinked polystyrene particles (refractive index of 1.59, average particle diameter of 4.0 μm) as fine particles (A) with respect to 100 parts by mass of the radiation curable adhesive. 100 parts by mass of the radiation-curable adhesive and containing 20.0 parts by mass of talc particles (refractive index: 1.57, average particle diameter D50: 0.8 μm) as a layered inorganic compound, which is blended with respect to 100 parts by mass of the radiation curable adhesive. A coating liquid was prepared by using 190 parts by mass of a mixture of toluene and methyl isobutyl ketone (mass ratio of 8:2) as a solvent.

The obtained coating liquid was allowed to stand for 24 hours, and then applied to a light-transmitting substrate by gravure printing, and dried at 70 ° C at a flow rate of 1.2 m/s, and dried for 1 minute to form a coating film.

Then, the coating film was irradiated with ultraviolet rays (200 mJ/cm ^{2 in a} nitrogen atmosphere), and the radiation-curable adhesive was cured to form a diffusion layer, thereby producing an anti-glare film. Further, the thickness of the diffusion layer was 6.6 μm.

(Examples 2 to 7, Comparative Examples 1 to 9, and Reference Example 1)

An anti-glare film was produced in the same manner as in Example 1 except that the thickness of each component added to the coating liquid and the thickness of the formed diffusion layer was set as shown in Table 1.

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

(Microparticle A)

A: Highly crosslinked polystyrene particles (refractive index: 1.59, average particle diameter: 4.0 μm, manufactured by Amika Chemical Co., Ltd.)

B: Highly crosslinked acrylic acid-polystyrene particles (refractive index: 1.57, average particle diameter: 3.5 μm, manufactured by Amika Chemical Co., Ltd.)

C: highly crosslinked polystyrene particles (refractive index: 1.59, average particle diameter: 2.0 μm, manufactured by Soken Chemical Co., Ltd.)

D: highly crosslinked polystyrene particles (refractive index: 1.59, average particle diameter: 9.0 μm, manufactured by Amika Chemical Co., Ltd.)

(Organic Microparticles B)

E: low cross-linked acrylic particles (refractive index 1.49, average particle diameter 5.0 μm, manufactured by Soken Chemical Co., Ltd.)

(layered inorganic compound)

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

N: bentonite (refractive index 1.52, average particle diameter 0.5 μm, manufactured by Ho Jun Co., Ltd.)

(radiation hardening type adhesive)

P: a mixture of neopentyl alcohol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), and polymethyl methacrylate (PMMA) (mass ratio: PETA/DPHA/PMMA=86/5 /9) (refractive index 1.51)

Q: Neopentyl alcohol triacrylate (PETA) (refractive index 1.51)

R: a mixture of 60 parts of vinyl acetate resin and 40 parts of methyl methacrylate resin (refractive index 1.47)

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

(Measurement of aggregates)

The antiglare films obtained in the examples, the comparative examples, and the reference examples were cut along the thickness direction, and 20 microparticles (A) were randomly observed by the cross-sectional SEM, and the "two microparticles (A) were formed to form a line connecting the centers of the two. The ratio of the aggregates formed by the condensation of the surface of the light-transmitting substrate at an inclination angle of 20 to 70°.

(Measurement of the tilt angle of the aggregate)

The antiglare films obtained in the examples, the comparative examples, and the reference examples were cut in the thickness direction, and 20 microparticles (A) were randomly observed by a cross-sectional SEM, and the agglomerates obtained by agglomerating the two microparticles (A) were measured and connected. The average value of the inclination angle formed by the straight line of the center with respect to the surface of the light-transmitting substrate was evaluated based on the following criteria.

○: The average value of the inclination angle is in the range of 30 to 60°

△: The average value of the inclination angle is 30 to 60°, but it is in the range of 20 to 70°.

×: The average value of the inclination angle is outside the range of 20 to 70°

In addition, FIG. 2 is a cross-sectional SEM photograph of an aggregate in which two fine particles (A) in a diffusion layer of the antiglare film of Example 1 are agglomerated.

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

The anti-glare film containing the organic fine particles (B) in the diffusion layer was cut along the thickness direction, and five organic fine particles (B) were observed by observing the cross-sectional SEM in a total of 10 places at each of the organic fine particles (B). The thickness of the impregnation layer formed in the cross section is measured, and the average value thereof is calculated.

Further, Fig. 3 shows one of the cross-sectional SEM photographs of the diffusion layer of the anti-glare film of Example 2, and Fig. 4 shows one of the cross-sectional SEM photographs of the diffusion layer of the anti-glare film of Example 3.

(contrast)

The anti-glare film obtained in the examples, the comparative examples and the reference examples was bonded to the black acrylic plate with a transparent adhesive film using an optical film, and the anti-glare film was applied from all directions to the subject under the condition of 1000 Lx of the bright room. The surface state was evaluated visually. It was judged whether or not the vivid black color could be reproduced, and the evaluation was performed based on the following criteria.

◎: The answer is good for more than 10 people

○: 9-8 people answered with good people

△: 7-5 people answered as good people

×: The number of people who answered well is less than 4

(anti-glare and scintillation evaluation)

The polarizing plate of the outermost surface of the LCD TV "KDL-40×2500" manufactured by Sony Corporation was peeled off, and a polarizing plate without surface coating was attached.

Then, a transparent adhesive film for an optical film (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) is used as the outermost surface of the diffusion layer side. The anti-glare film obtained in the examples, the comparative examples, and the reference examples was attached to the manufacture of Nippon Chemical Co., Ltd., and the like.

The liquid crystal television is placed in a room with an illuminance of about 1000 Lx, and a white screen display is performed. The subject is 15 people from a distance of about 1.5 to 2.0 m from the liquid crystal television, and the anti-glare and flicker are from the upper, lower, left and right angles. Visual function evaluation was performed separately. Evaluation was performed based on the following criteria.

◎: The answer is good for more than 10 people

○: 9-8 people answered with good people

△: 7-5 people answered as good people

×: The answer is good for 4 or less people

(hard coating)

According to JIS K5600-5-4 (1999), the pencil hardness test was performed on the surfaces of the anti-glare films of the examples, the comparative examples, and the reference examples by dividing five lines with a load of 750 g and 3H.

○: In the pencil hardness test of 3H, the number of scratches is 2 or less.

△: 3 to 4 scratches in the pencil hardness test of 3H

×: 5 scratches in the pencil hardness test of 3H

As shown in Table 2, the anti-glare films of Examples 1, 2, 4 and 7 were excellent in contrast, anti-glare property, scintillation and hard coatability. The slanting angle of the fine particles (A) of the anti-glare film of Example 3 is in the range of 60 to 70°, so that the evaluation of the scintillation is poor, and the content of the layered inorganic compound of the anti-glare film of Example 5 is less than that of the first embodiment. Therefore, the hard coating property is poor, and the content of the layered inorganic compound of the antiglare film of Example 6 is much larger than that of Example 1, etc., the viscosity of the coating liquid is high, and the surface smoothness of the antiglare film is poor, so contrast, anti-glare property, and The evaluation of the flicker was poor, but the whole was judged to be a good result.

On the other hand, the anti-glare film of the comparative example was not excellent in contrast, anti-glare property, flicker, and hard coat property.

Further, since the average particle diameter of the organic fine particles (B) of the antiglare film of Reference Example 1 is equal to or greater than the thickness of the diffusion layer, contrast and hard coatability are inferior.

[Industrial availability]

The anti-glare film of the invention can be preferably applied to 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. Especially high-definition displays.

10. . . Anti-glare film

11. . . Light transmissive substrate

12. . . Diffusion layer

13. . . Microparticles (A)

Fig. 1 is a cross-sectional view schematically showing a state of aggregates in a diffusion layer of an anti-glare film of the present invention.

2 is a cross-sectional SEM photograph showing an aggregate of two fine particles (A) in a diffusion layer of the antiglare film of Example 1.

3 is a cross-sectional SEM photograph of a diffusion layer of the anti-glare film of Example 2.

4 is a cross-sectional SEM photograph of a diffusion layer of the anti-glare film of Example 3.

10. . . Anti-glare film

11. . . Light transmissive substrate

12. . . Diffusion layer

13. . . Microparticles (A)

Claims (13)

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 diffusion layer containing fine particles (A) and containing A coating liquid of a radiation curable adhesive having a methyl acrylate monomer as an essential component is applied onto at least one surface of the light-transmitting substrate, dried to form a coating film, and the coating film is cured. 50% or more of the fine particles (A) in the diffusion layer, and two aggregates formed by aggregating a line connecting the centers of the opposite sides with respect to the surface of the light-transmitting substrate; the coating liquid further The organic fine particles (B) are contained, and the average particle diameter of the organic fine particles (B) in the diffusion layer is larger than the fine particles (A) in the diffusion layer; the organic fine particles (B) in the diffusion layer are impregnated with radiation hardening type bonding The impregnated layer of the agent has an average thickness of 0.01 to 1.0 μm. An anti-glare film according to the first aspect of the invention, wherein the two microparticles (A) forming the agglomerate are connected to each other at a center line and at an inclination angle of 20 to 70° with respect to the surface of the light-transmitting substrate. An anti-glare film according to claim 1 or 2, wherein the coating liquid further contains a layered inorganic compound. An anti-glare film according to claim 3, wherein the layered inorganic compound is talc. The anti-glare film of the third aspect of the invention, wherein 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. The anti-glare film according to claim 1 or 2, wherein the fine particles (A) are polystyrene fine particles and/or acrylic-styrene copolymerized fine particles. The anti-glare film according to claim 1 or 2, wherein when the average particle diameter of the fine particles (A) is D _A , the thickness T of the D _A with respect to the diffusion layer satisfies the following formula (A): 1.34 × D _A ) < T < (1.94 × D _A ) (A). An anti-glare film according to claim 1 or 2, wherein the organic fine particles (B) in the diffusion layer are not aggregated. An anti-glare film according to claim 1 or 2, wherein the coating liquid contains a solvent which causes the organic fine particles (B) to swell. The anti-glare film according to claim 1 or 2, wherein when the average particle diameter of the organic fine particles (B) is D _B , the thickness T of the D _B with respect to the diffusion layer satisfies the following formula (B): D _B <T (B). A method for producing an anti-glare film 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; and having the following steps: Applying a coating liquid containing the fine particles (A) and a radiation-curable adhesive containing a (meth) acrylate monomer as an essential component to at least one surface of the light-transmitting substrate, and drying to form a coating film And forming the diffusion layer by hardening the coating film; 50% or more of the fine particles (A) in the diffusion layer are formed in such a manner that a line connecting the centers of each other is inclined at an oblique angle with respect to a surface of the light-transmitting substrate Agglomerated aggregate; the coating liquid further contains organic fine particles (B), and the average particle diameter of the organic fine particles (B) in the diffusion layer is larger than the fine particles (A) in the diffusion layer; organic in the diffusion layer The fine particles (B) have an impregnation layer impregnated with a radiation hardening type adhesive, and the average thickness of the impregnation layer is 0.01 to 1.0 μm. A polarizing plate comprising a polarizing element; and an anti-glare film of the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth or tenth patent of the patent application on the surface of the polarizing element. An image display device having an anti-glare film of the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth or tenth patent application or a polarizing plate of claim 12 on the outermost surface.