JPH07325203A - Antiglare antireflection film, polarizing plate and liquid crystal display device - Google Patents

Abstract

(57) [Abstract] [Purpose] It has antiglare property and antireflection property at the same time and can reduce the reflection of light at the interface between each internal layer. Excellent adhesion,
An object is to provide an antireflection film having a high antireflection effect, and a polarizing plate and a liquid crystal display device using the antireflection film. [Structure] An antiglare layer 2 having a fine uneven surface is formed on the transparent substrate film 1 directly or via another layer. The low refractive index layer 3 having a low refractive index is formed. This low refractive index layer 3
Are formed by laminating two different types of first low refractive index layer 4 and second low refractive index layer 5 in this order. The refractive index of the antiglare layer 2 is a layer in contact with the surface of the antiglare layer 2 opposite to the surface in contact with the low refractive index layer 3 (for example, transparent substrate film, primer layer, adhesive agent). Layer, second hard coat layer, etc.).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various displays such as word processors, computers and televisions, surfaces of polarizing plates used in liquid crystal display devices, optical lenses such as transparent plastic sunglasses lenses, prescription eyeglass lenses, and camera finder lenses. The present invention relates to an antiglare antireflection film which is excellent in antireflection of the surfaces of various instrument covers and window glass of automobiles and trains.

[0002]

2. Description of the Related Art Conventionally, transparent substrates such as glass and plastic have been used for curved mirrors, rearview mirrors, goggles, displays such as window glasses and personal computers and word processors, and various other commercial displays. When observing visual information of objects, characters, and figures through a substrate, or an image from a reflective layer through a transparent substrate with a mirror, the surface of these transparent substrates is reflected by light, making it difficult to see the internal visual information. was there.

As a method of preventing the reflection of such a transparent substrate, conventionally, a method of applying an antireflection coating on the surface of glass or plastic, or a film thickness of 0.1 μm on the surface of a transparent substrate such as a glass / plastic substrate. To the extent of MgF ₂ and S
A method for forming a thin film such as iO ₂ by vapor deposition or sputtering, and a thin film such as MgF ₂ or SiO ₂ is formed on a hard coat layer obtained by coating a plastic surface such as a plastic lens with an ionizing radiation curable resin. There was a method of forming a coating film having a low refractive index on a hard coat layer made of an ionizing radiation curable resin or the like.

Film thickness of 0.1 μm formed on the glass
A thin film of MgF _{2 to} the extent is further described. When incident light is vertically incident on the thin film, a specific wavelength is λ _o , the refractive index of the antireflection film for this wavelength is n _o , the thickness of the antireflection film is h, and the refractive index of the substrate is n _g . Then, it is already known that the condition for the antireflection film to prevent 100% of light reflection and to transmit 100% of light needs to satisfy the relations of the following expressions (1) and (2). (Science Library Physics = 9 "Optics" 70-72, Showa 55
Published by Science Co., Ltd.).

[0005]

## EQU1 ## n _o = √n _g Equation (1)

[0006]

[Number 2] n _o h = λ _o / 4 formula (2)

The refractive index of glass n _g = about 1.5 and M
gF2 film refractive index n _o = 1.38, the wavelength of the incident light lambda _o =
Since it is already known to be 5500Å (reference), by substituting these values into the equation (2), it is calculated that the optimum thickness h of the antireflection film is about 0.1 μm.

According to the above equation (1), light reflection is 100
%, It is understood that it is sufficient to select a material in which the refractive index of the upper coating film is approximately the square root of the refractive index of the lower coating film. It has been conventionally practiced to prevent light reflection by setting the refractive index of the coating film to a value slightly lower than the refractive index of the underlying coating film.

Conventionally, the surface of a display or the like has been subjected to an antiglare treatment in order to diffuse the light emitted from the outside or the inside thereof to the extent that the surface of the display or the like is not dazzled. Such anti-glare treatment includes, for example,
A resin containing a filler such as silicon dioxide was coated on the display surface, or an antiglare substrate formed by coating a resin containing a filler such as silicon dioxide on a transparent substrate was attached to the display surface. .

In particular, a film-shaped polarizing element which functions as a light shutter is provided on the surface of a display body such as a liquid crystal display. However, since the polarizing element itself is inferior in hardware performance, glass or transparent plastic is used. A polarizing plate is formed by being protected by a transparent protective substrate made of a plate or a plastic such as a transparent plastic film. However, the transparent protective substrate itself made of a plastic such as a transparent plastic plate or a transparent plastic film is also easily scratched, and thus in recent years, such a polarizing plate having a hard performance has been developed.
As such a technique, for example, Japanese Patent Laid-Open No. 1-10573
There is one described in Japanese Patent Publication No. 8.

This publication discloses a transparent protective substrate provided with a hard performance and an antiglare property, that is, a triacetate film for light control, which is laminated on a polarizing element to form a polarizing plate. This film is a triacetate film having excellent scratch resistance by providing a cured coating film made of an ultraviolet curable epoxy acrylate resin on one surface of an unsaponified triacetate film.

In order to further impart antiglare property to the triacetate film having excellent scratch resistance, conventionally, a resin composition obtained by adding amorphous silica to the UV-curable epoxy acrylate resin is applied to the surface of the triacetate film. Then it is cured. When the thus obtained triacetate film is attached to a polarizing element to form a polarizing plate, saponification with an alkali is performed to improve the adhesiveness with the polarizing element and to prevent static electricity, and then ,
A polarizing plate is manufactured by bonding it to a polarizing element.

[0013]

However, a film thickness of 0.1 μm is formed on the surface of a transparent substrate such as a glass / plastic substrate.
A method of forming a thin film of MgF ₂ or SiO ₂ of about m by vapor deposition or sputtering, or MgF ₂ or SiO on a hard coat layer obtained by coating a plastic surface such as a plastic lens with an ionizing radiation curable resin. _{In the} conventional antireflection film obtained by a method of forming a thin film such as _2, a method of forming a coating film having a low refractive index on the hard coat layer made of an ionizing radiation curable resin or the like,
The MgF ₂ film alone has a sufficiently low refractive index, but has poor adhesion to a plastic substrate or hard coat layer, hard performance, etc., and the SiO ₂ film alone has a plastic substrate or hard coat layer. Although it has excellent adhesiveness with and hard performance, it has a problem that it has a poor optical antireflection effect because it does not have a sufficiently low refractive index.

Further, since the coating film formed for improving the hard performance of the transparent protective substrate such as the conventional transparent plastic film and transparent plastic plate is usually as thick as several μm, the light incident from the outside is the coating film. Since the light is reflected at the interface with other layers, it has been a cause of reducing the antireflection effect.

On the other hand, in the conventional antireflection film having the antireflection layer formed on the outermost surface of the transparent plastic film, since the low refractive index layer has a thin thickness of about 0.1 μm,
The formed antireflection film was inferior in hard performance and was apt to be scratched.

Therefore, an object of the present invention is to have antiglare property and antireflection property at the same time, and it is possible to reduce the reflection of light at the interface between the respective internal layers, and further, to combine the low refractive index layer and the antiglare layer. An object of the present invention is to provide an antireflection film having excellent interlayer adhesion and a high antireflection effect, and a polarizing plate and a liquid crystal display device using the antireflection film.

[0017]

In order to solve the above-mentioned problems, the antiglare antireflection film of the present invention has a fine surface either directly on the transparent substrate film or through another layer. An uneven antiglare layer is formed, and on the antiglare layer,
In an antiglare antireflection film formed by forming a low refractive index layer having a refractive index lower than that of the antiglare layer, the low refractive index layer has two different types of first low refractive index layer and second low refractive index. The layers are formed by laminating in this order, and the refractive index of the antiglare layer is a layer in contact with the surface of the antiglare layer opposite to the surface in contact with the low refractive index layer (for example, Transparent substrate film, primer layer, adhesive layer, second hard coat layer, etc.).

In the antireflection film of the present invention, one of the first low refractive index layer and the second low refractive index layer is Si.
It is desirable that consist O _x, wherein the first as a combination of the low refractive index layer and the second low refractive index layer, a first low refractive index layer: MgF _2, the second low-refractive index layer: SiO _x, first A low refractive index layer: SiO _x and a second low refractive index layer: MgF ₂ can be considered. Further, the film thickness of each of the first low refractive index layer and the second low refractive index layer is preferably 10 to 100 nm, and further, the total film thickness thereof is preferably 50 to 200 nm.

The first low refractive index layer and the second low refractive index layer can be formed by a vapor phase method, and preferably the plasma CVD method can be used as the vapor phase method.

The antiglare layer preferably comprises a layer containing a binder resin as a main component, and may further have a hard property. As the light-sensitive molecule or atom of the binder resin, one or more kinds of molecules selected from (1) aromatic ring, (2) halogen atom other than F, (3) atom of S, N and P. And / or those containing an atom can be used, and further, a thermosetting resin and / or an ionizing radiation curable resin can also be used.

The thickness of the antiglare layer may be 0.5 μm or more, and ultrafine particles of high refractive index (eg ZnO, Ti) having a refractive index of 1.5 or more higher than that of the binder resin.
O ₂ , Ce ₂ O ₃ , Sb ₂ O ₅ , SnO ₂ , ITO, C
eO ₂ etc.) may be contained. The polarizing plate of the present invention is characterized in that the antiglare antireflection film of the present invention is laminated on a polarizing element.

The liquid crystal display device of the present invention is characterized in that the polarizing plate of the present invention is used as a constituent element of the liquid crystal display device. Hereinafter, each configuration of the present invention will be described in more detail.

Antiglare property and antireflection property In the present invention, the antiglare property is defined by fine irregularities on the surface of the antiglare layer formed on the surface of a display or the like, or by a matting agent disposed in the antiglare layer. A phenomenon in which the reflection of external light is diffused and becomes diffuse reflection, which reduces the reflection on the screen of a fluorescent lamp or the like. In such an antiglare layer, transmitted light from the display body is diffused, so that there is a drawback that the resolution and the contrast are lowered.

In the present invention, antireflection means that the reflection energy of external light is reduced by an interference action, so that the reflection of external light is slightly reduced and the amount of transmitted light from the display body is increased (that is, Reflection is reduced), so that the resolution and contrast are increased.

Therefore, the antiglare antireflection film becomes an antireflection film having antiglare properties imparted to the antireflection property,
For example, when such a film is used for a display device,
At the same time as low reflection, the transmittance is remarkably increased, the image is bright, the contrast is improved, and the visibility is good.

In the present invention, the antiglare antireflection is intended to make up for the defects of both the antiglare property and the antireflection property, such as regular reflection of light, diffuse reflection, reflection of external light and contrast. Has been improved. In particular, a film having an antiglare property has a drawback that the light transmitted from the back is diffused and transmitted, and when such a film is used for a display device, the image on the surface becomes dark. The antiglare antireflection film of the invention has a characteristic that the transmittance is remarkably increased at the same time as the low reflection, so that the image is bright and
It has the features of improved contrast and good visibility. The properties of the above-mentioned antiglare, antireflection and antiglare antireflection are shown in Table 1 below.

[0027]

[Table 1]

Transparent Substrate Film As the transparent substrate film, triacetyl cellulose film, diacetyl cellulose film, acetate butyrate cellulose film, polyether sulfone film, polyacrylic resin film, polyurethane resin film, polyester film, polycarbonate. Films, polysulfone films, polyether films, trimethylpentene films, polyetherketone films, (meth) acrylonitrile films and the like can be used, but especially triacetyl cellulose film,
Further, uniaxially stretched polyester is preferably used because it is excellent in transparency and has no optical anisotropy. Its thickness is usually 8μ
Those having a thickness of about m to 1000 μm are preferably used.

Antiglare Layer On the surface of the antiglare layer of the present invention, fine irregularities having an antiglare property are formed. The method of forming such fine irregularities is performed by using a mat-shaped imprinting film having fine irregularities on the surface, or by applying a matting material 6 such as plastic beads to a binder resin. It can be carried out by forming a coating film with a hydrophilic paint or by using surface shaping and addition of a matting material in combination. When fine irregularities are formed on the surface without using a mat material for imparting the antiglare property, the transparency of the resulting antiglare antireflection film is not particularly impaired.

The shape-imparting film used for forming the fine unevenness by the shape-imparting is a plastic film such as PET film having releasability provided with desired unevenness, or a plastic film such as PET film. Conventionally known ones such as those provided with a fine concavo-convex layer can be used.

FIG. 1 shows the layer structure of the antiglare antireflection film of the present invention obtained by using the above-mentioned shaped film, 1 being a transparent substrate film, 2 an antiglare layer, 3 Is a low refractive index layer, 4 is a first low refractive index layer, and 5 is a second low refractive index layer.

For the mat member described above, for example, plastic beads are highly transparent and have a refractive index close to that of the matrix resin, and therefore, they can be preferably used. When the matte material has a refractive index as close as possible to that of the resin, the transparency of the coating film is not impaired and the antiglare property can be increased. Examples of such plastic beads include acrylyl beads, polycarbonate beads, polystyrene beads, and vinyl chloride beads. The particle size of these plastics is preferably 1 to 10 μm.

Further, since these mat materials easily settle in the resin composition, an inorganic filler such as silica may be added to prevent this from occurring. The more the inorganic filler is added, the more effective it is in preventing the matting material from settling.
Since it has a bad influence on the transparency of the coating film, it is preferably added in an amount of less than 0.1% by weight. The silica used in this case differs from silica having a particle size of about 5 μm, which is used as a conventional mat material, in that the particle size is very small, and the effect of addition is not effective in imparting antiglare properties. Further, the amount of its use is also different in that the conventional mat material is used in an amount of 1 to 30% by weight, whereas the amount of use is extremely small in the present invention. Incidentally, when the present invention is carried out without adding an inorganic filler which is an anti-settling material for preventing the mat material from settling, the mat material is settled to the bottom when the paint is used. Good.

FIG. 2 shows the layer structure of the antiglare antireflection film of the present invention when the mat material is added to the resin constituting the antiglare layer. It is what is formed.

Although not shown in the drawing, the antiglare coating may be surface-molded on the antiglare coating.

As the binder resin that can be used in the antiglare layer, any resin (for example, thermoplastic resin, thermosetting resin, ionizing radiation curing resin, etc.) can be used as long as it is transparent. be able to. In order to impart hardness to the antiglare layer and impart excellent hard performance to the finally obtained antiglare antireflection film, the thickness of the antiglare layer is 0.5 μm or more, preferably 3 μm or more. The hardness can be maintained and the hard performance can be imparted to the antiglare antireflection film.

In the present invention, the term "giving hard performance" or "hard coat" means JISK540.
In the pencil hardness test shown in 0, the pencil hardness test is H or higher.

In order to further improve the hardness of the antiglare layer, the binder resin used in the antiglare layer is a reaction curable resin, that is, a thermosetting resin and / or an ionizing radiation curable resin. Is desirable. The thermosetting resin,
Phenol resin, urea resin, diallyl phthalate resin,
Melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea co-condensation resin, silicon resin, polysiloxane resin, etc. are used, and if necessary, a crosslinking agent for these resins is used. A curing agent such as a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier, etc. are added and used.

As the ionizing radiation curable resin,
Preferably, those having an acrylate-based functional group, for example, relatively low molecular weight polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin,
Alkyd resin, spiro acetal resin, polybutadiene resin, polythiol polyene resin, oligomer or prepolymer such as (meth) acrylate of polyfunctional compound such as polyhydric alcohol and ethyl (meth) acrylate, ethylhexyl (meth) acrylate as reactive diluent , Styrene, methylstyrene, N-vinylpyrrolidone, and other monofunctional and polyfunctional monomers such as trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di ( (Meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, etc. Which relatively high content can be used.

Particularly preferably, a mixture of polyester acrylate and polyurethane acrylate is used. The reason is that polyester acrylate is suitable for obtaining a hard coat because the coating is very hard, but polyester acrylate alone has a low impact resistance and becomes brittle, so that the coating has impact resistance and flexibility. Polyurethane acrylate is used together to impart the property. The mixing ratio of polyurethane acrylate to 100 parts by weight of polyester acrylate is 30 parts by weight or less. This is because if the value exceeds this value, the coating film becomes too soft and loses its hardness.

Further, in order to use the above ionizing radiation curable resin as an ultraviolet curable resin, acetophenones, benzophenones, Michler benzoyl benzoate, α-amyloxime ester and tetramethyl are used as photopolymerization initiators therein. Thiuram monosulfide, thioxanthone, and n-butylamine, triethylamine, tri-n-butylphosphine and the like can be mixed and used as a photosensitizer. Particularly in the present invention, it is desirable to mix urethane acrylate as an oligomer and dipentaerythritol hexaacrylate as a monomer.

Particularly, it is preferable that the solvent-drying resin is contained in an amount of 10 parts by weight or more and 100 parts by weight or less with respect to 100 parts by weight of the ionizing radiation-curable resin. The solvent drying type resin,
Thermoplastic resins are mainly used. The type of solvent-drying resin to be added to the ionizing radiation-curable resin is the one that is normally used, but especially when a mixture of polyester acrylate and polyurethane acrylate is used for the ionizing radiation-curable resin, the solvent used As the dry resin, poly (methyl methacrylate) or poly (butyl methacrylate) can keep the hardness of the coating film high. Moreover, in this case, since the refractive index is close to that of the main ionizing radiation-curable resin, the transparency of the coating film is not impaired, and the transparency is particularly advantageous in terms of low haze value, high transmittance, and compatibility. .

When a cellulosic resin such as triacetyl cellulose is used as the transparent substrate film, the solvent-drying resin contained in the ionizing radiation-curable resin is nitrocellulose, acetyl cellulose or cellulose acetate propionate. Cellulose resins such as ethyl hydroxyethyl cellulose are advantageous in terms of adhesion and transparency of the coating film.

The reason is that when toluene is used as a solvent in the above cellulose-based resin, the transparent base material film is used in spite of using toluene which is a non-soluble solvent of triacetyl cellulose. Adhesion between the transparent substrate film and the coating resin can be improved even if a coating material containing this solvent-drying resin is applied on top of this. This is because the acetyl cellulose film is not dissolved, so that the surface of the transparent substrate film is not whitened and there is an advantage that transparency is maintained.

For forming the antiglare layer, a method of coating on the transparent substrate film or a method of transferring onto the transparent substrate film by transfer can be used.

When the antiglare layer shown in FIG. 1 is formed, the former coating method may be carried out directly on the transparent substrate film or through another layer, for example, by a gravure reverse coating method for the antiglare layer. Of the resin composition described above, and then a mat-shaped patterning film having fine irregularities on the surface of the formed coating film is laminated with the irregular surface of the coating film side, and then the obtained laminate It can be formed by subjecting the coating film to heat treatment and / or ionizing radiation irradiation treatment to cure the coating film, and then peeling off the patterning film.

In the latter transfer method, the resin composition for the antiglare layer is applied onto the uneven surface of the shape-imparting film by, for example, a gravure reverse coating method to form a coating film. On the other hand, on at least one of the front and back surfaces of the transparent substrate film, directly or through another layer, a transfer film on which the coating film of the above step is formed is laminated with the coating film as an inner side, and this laminate The article can be formed by subjecting the article to heat treatment and / or ionizing radiation irradiation treatment to cure the coating film, and then peeling the shaped film from the cured laminate of the coating film. In the transfer method, the coating film may be cured before laminating.

When the antiglare layer shown in FIG. 2 is formed, the antiglare coating material may be applied onto the transparent substrate film 1.
Of course, it is also possible to further perform surface shaping on the antiglare layer of FIG.

Since the antiglare layer according to the present invention is a coating film formed by coating, the thickness thereof is 0.5 μm or more as described above, and the vapor phase method (for example, vacuum deposition, sputtering, ion plating, plasma) is used. It is thicker than the film thickness by the CVD method). Thus, the obtained antireflection film has hard performance.

In order to increase the refractive index of the antiglare layer, a binder resin having a high refractive index is used, or high refractive index fine particles having a refractive index higher than that of the binder resin used for the antiglare layer. Is added to the binder resin, or these are used in combination.

The binder resin having a high refractive index includes
A resin containing an aromatic ring, a halogenated element other than F, for example, a resin containing Br, I, Cl, etc., a resin containing an atom such as S, N, P, etc. are mentioned, and at least one of these conditions is satisfied. It is desirable because the resin has a high refractive index.

Examples of the above resins include styrene resins such as polystyrene, polyethylene terephthalate, polyvinylcarbazole, and polycarbonate of bisphenol A.

Examples of the above resin include polyvinyl chloride,
Examples thereof include polytetrabromobisphenol A glycidyl ether.

The high refractive index fine particles include, for example, ZnO.
(Refractive index 1.90), TiO ₂ (refractive index 2.3-2.
7), CeO ₂ (refractive index 1.95), Sb ₂ O ₅ (refractive index 1.71) SnO ₂ , ITO (refractive index 1.95),
Y ₂ O ₃ (refractive index 1.87), La ₂ O ₃ (refractive index 1.
95), ZrO ₂ (refractive index 2.05), Al ₂ O ₃ (refractive index 1.63) and the like. Among these high refractive index fine particles, it is preferable to use ZnO, TiO ₂ , CeO ₂ or the like, because the antireflection film of the present invention is further provided with a UV shielding effect, which is preferable. Further, by using antimony-doped SnO ₂ or ITO, electron conductivity is improved, dust is prevented from adhering due to an antistatic effect, or the antireflection film of the present invention is used as a CRT.
It is preferable because it can provide an electromagnetic wave shielding effect when used for. The particle size of the high refraction fine particles is preferably 400 nm or less in order to make the hard coat layer transparent.

When an ionizing radiation curable resin is used as a binder resin in the antiglare layer, it can be cured by the curing method, that is, irradiation with an electron beam or ultraviolet rays. For example, in the case of electron beam curing, 50 to 1000 KeV emitted from various electron beam accelerators such as Cockloft-Walton type, Van de Graaff type, resonance transformer type, insulating core transformer type, linear type, dynamitron type, and high frequency type, An electron beam or the like having an energy of 100 to 300 KeV is preferably used, and in the case of ultraviolet curing, an ultrahigh pressure mercury lamp,
Ultraviolet rays emitted from light rays of a low-pressure mercury lamp, carbon arc, xenon arc, metal halide lamp, etc. can be used.

Low Refractive Index Layer A low refractive index layer is formed on and in contact with the antiglare layer. The refractive index n _L of this low refractive index layer is the refractive index n _L of the antiglare layer.
_It goes without saying that the range is lower than _H ,
As is clear from the formulas (1) and (2), when the thickness of the low refractive index layer is h _L , the following formula (3) and the following formula (4)

[0057]

[Formula 3] n _L = √n _H formula (3)

[0058]

Equation 4] _{n L h L = λ O /} 4 Equation (4) the closer so as to satisfy the relationship, the antireflection effect is enhanced.

The total film thickness of the low refractive index layer is calculated by the above formula (3).
And (4) are preferably selected, but in consideration of securing the film strength and the like, 50 to 200 nm,
It is desirable to set the thickness to about 80 to 150 nm. If it is less than 50 nm, the center wavelength according to the above formula (4) at which reflection should be prevented shifts to a shorter wavelength than the visible light region, so that the antireflection effect is significantly reduced, and 200 nm
If the value exceeds, the central wavelength according to the above formula (4) for preventing reflection shifts to a wavelength longer than the visible light region, so that the antireflection effect is significantly reduced.

The low-refractive index material used for forming the low-refractive index layer may be any one as long as it satisfies the above conditions, and the inorganic material is suitable because it has a high hardness and a film can be formed by a vapor phase method. used.

Examples of the low refractive index inorganic material include:
LiF (refractive index 1.4), MgF ₂ (refractive index 1.4),
3NaF · AlF ₃ (refractive index 1.4) AlF ₃ (refractive index 1.4), NaMgF ₃ (refractive index 1.36), Na ₃ A
IF ₆ (cryolite, refractive index 1.33), SiO _x (x:
1.8 <x <2.2, refractive index 1.40 to 1.46) and the like.

Since this low refractive index layer is formed on the antiglare layer having fine irregularities on the surface, the low refractive index layer material is formed in the concave portions of the fine irregularities of the antiglare layer by forming the low refractive index. Concentrate so that the surface of the low refractive index layer is not flat.

As a method of forming the low refractive index layer, a vapor phase method is preferable, and for example, it is desirable to form it by a vacuum vapor deposition method, a sputtering method, an ion plating method, a plasma CVD method or the like. In particular, a film formed of SiO _x ,
More preferably, the film formed by the plasma CVD method has a good film hardness, becomes a scratch resistant film, and has excellent adhesiveness with other resin layers, so that heat damage to the transparent base film may be prevented. It is preferable because it can be reduced as compared with the gas phase method.

In the antiglare antireflection film of the present invention, as shown in FIG. 1 or 2, the low refractive index layer 3 has two different types of first low refractive index layer 4 and second low refractive index layer 5. Are laminated in this order. The first low-refractive index layer 4 and the second low-refractive index layer 5 may be formed by using two different kinds of low-refractive index inorganic materials as described above, but the film strength, the adhesion, and the scratch resistance. Considering the above, 2
It is preferable that one of the low refractive index layers is a SiO _x film.

When SiO _x is used for the first low refractive index layer 4, the strength of the antiglare antireflection film is increased and a low refractive index layer excellent in adhesion to the antiglare layer 2 is formed. You can

Further, when SiO _x is used for the second low refractive index layer 5, the strength of the antiglare antireflection film is increased, the adhesion to the lower first refractive index layer is good, and the surface is further improved. It is possible to obtain an antiglare antireflection film having excellent scratch resistance and having vapor deposition particles colliding with the lower first low refractive index layer, in which the film strength of the first low refractive index layer is increased.

Further, the SiO _x film has a slightly higher antireflection effect when used as the second low refractive index layer than when used as the first low refractive index layer.

Since the refractive index is not so low only with the above-mentioned SiO _x film, the optical antireflection effect is poor.
a low refractive index inorganic material having a lower refractive index than iO _x ,
The other low refractive index layer is formed. In this case, especially Mg
The use of F ₂ is preferable in that water resistance is imparted and vapor deposition can be performed with low power, so that heat damage to the transparent substrate film is small.

The thickness of each of the first low refractive index layer and the second low refractive index layer is preferably 10 to 100 nm from the viewpoints of optical characteristic function and manifestation of mechanical strength. Although the total ideal film thickness of the two layers has been described above, it is desirable that the film thicknesses of the two layers are equal to each other in order to develop the characteristics of the films of the two layers in a well-balanced manner.

Other Layers In addition to the above-mentioned layers, the antiglare and antireflection film of the present invention may further be provided with layers for imparting respective functionalities. For example, for the purpose of improving the adhesiveness of the adhesion between the transparent substrate film and the antiglare layer, a primer layer or an adhesive layer may be provided on the transparent substrate film, or,
A plurality of hard coat layers may be provided to improve the hard performance. As described above, the refractive index of the other layer formed between the transparent substrate film and the antiglare layer is preferably an intermediate value between the refractive index of the transparent substrate film and the refractive index of the antiglare layer.

The other layer may be formed by directly or indirectly coating on the transparent substrate film as described above, or by forming the antiglare layer on the transparent substrate film by transfer. In this case, another layer is formed by coating on the antiglare layer previously formed on the transfer film having fine irregularities on the surface, and then the transparent substrate film and the transfer film are placed with the coated surface inside. Other layers may be transferred onto the transparent substrate film by laminating the transfer film and then peeling off the transfer film.

An adhesive may be applied to the lower surface of the antiglare antireflection film of the present invention. In this case, the antiglare antireflection film is attached to an object to be antireflection, for example, a polarizing element. It can be worn and used.

By laminating the antiglare antireflection film of the present invention on a polarizing plate and a polarizing element of a liquid crystal display device, a polarizing plate having improved antireflection properties can be obtained. For this polarizing element, a polyvinyl alcohol film, a polyvinyl former film, a polyvinyl acetal film, an ethylene-vinyl acetate copolymer saponified film obtained by dyeing with iodine or a dye and stretching can be used. In order to increase the adhesiveness and prevent static electricity in this laminating process, the transparent base film of the antiglare antireflection film is, for example, a triacetyl cellulose film,
The triacetyl cellulose film is saponified. This saponification treatment may be performed before or after applying the antiglare layer to the triacetyl cellulose film.

FIG. 3 shows an example of a polarizing plate using the antireflection film of the present invention. In the figure, 7 is the antiglare antireflection film of the present invention, and as described above, the TAC film (abbreviation of triacetylcellulose film) 8 as the transparent substrate film, the antiglare layer 9, the first low refractive index Rate layer 11
And the low refractive index layer 10 including the second low refractive index layer 12. The antiglare antireflection film 7 is laminated on the polarizing element 13, while the TAC film 14 is laminated on the other surface of the polarizing element 13.
An adhesive layer is provided between the layers of the polarizing plate, if necessary. In particular, it is desirable to provide an adhesive layer between the antiglare layer 9 and the TAC film 8. The layer structure of the polarizing plate shown in FIG. 3 can be simply expressed as TAC film / polarizing element / antiglare antireflection film.

FIG. 4 shows an example of a liquid crystal display device using the antiglare antireflection film of the present invention. Liquid crystal display element 1
5, the polarizing plate shown in FIG. 3, that is, the TAC film /
A polarizing plate having a layer structure made of a polarizing element / antiglare antireflection film is laminated, and a polarizing plate having a layer structure made of TAC film / polarizing element / TAC film is laminated on the other surface of the liquid crystal display element 15. It is laminated.
Further, as shown in FIG. 4, the backlight is illuminated from the lower side of FIG. The antiglare antireflection film of the present invention is usually arranged on the emission side of a backlight. Also, the bottom surface TAC
The surface of the film 13 may be subjected to usual antireflection treatment. In the STN type liquid crystal display device, a retardation plate is inserted between the liquid crystal display element and the polarizing plate. An adhesive layer is provided between the respective layers of the liquid crystal display device as needed.

[0076]

【Example】

[Example 1] A triacetyl cellulose film (FT-UV-80: trade name, manufactured by Fuji Photo Film Co., Ltd., refractive index 1.49) having a thickness of 80 µm was prepared as a transparent substrate film. On the other hand, ZnO ultrafine particles (ZS-300: trade name, manufactured by Sumitomo Cement, refractive index 1.9) on a PET film (T-600: trade name, manufactured by Diamond Foil) with a thickness of 50 μm having fine irregularities on the surface. ) And an ionizing radiation curable resin (HN-2: trade name, manufactured by Mitsubishi Yuka, refractive index 1.54) in a weight ratio of 2: 1 to obtain a resin composition of 7 μm.
It was applied by a gravure reverse coat so as to have m / dry, and was irradiated with an electron beam at 175 kV for 4 Mrad to cure the coating film, thereby forming an antiglare layer having a high refractive index and having a hard property. An adhesive (Takelac: trade name, manufactured by Takeda Pharmaceutical Co., Ltd.) was applied on the obtained PET film to a thickness of 4 μm / dry.
To form an adhesive layer by gravure reverse coating, and then laminate on the transparent substrate film through the adhesive layer, and after aging at 40 ° C. for 3 days, the PET film Was peeled off to obtain an antiglare layer.

Next, a MgF ₂ film having a film thickness shown in Table 1 below is formed on the antiglare layer by a vacuum deposition method, and then a SiO _x film is further formed by a plasma CVD method to reduce the thickness. A refractive index layer was formed to obtain each antiglare antireflection film.

As a comparative example to Example 1, instead of the above low refractive index layer, SiO _x was added by plasma CVD to 10 times.
An antiglare antireflection film formed to a thickness of 00Å and an antiglare antireflection film formed of MgF ₂ to a thickness of 1000Å by a vacuum vapor deposition method were prepared, respectively, and total light transmittance (T) and diffuse transmittance were measured. (D), linear transmittance (PT), haze value (H = D / T), and hardness were compared with Example 1. The results are shown in Table 2 below.

[0079]

[Table 2]

Example 2 A triacetyl cellulose film having a thickness of 80 μm (FT-UV-80: trade name, manufactured by Fuji Photo Film Co., Ltd., refractive index 1.49) was used, and a particle size of 5 μm was used.
m polymethylmethacrylate beads and ionizing radiation curable resin (HN-2: trade name, manufactured by Mitsubishi Yuka, refractive index 1.5
4) and ZnO ultrafine particles (ZS-300: trade name, manufactured by Sumitomo Cement, refractive index 1.9) in a weight ratio of 1:10:20.
The resin mixed at a ratio of 6 μm / dry was applied by gravure reverse coating, and the electron beam was applied at 15
The coating film was cured by irradiation with 4 Mrad at 0 kV. The surface of the cured coating film formed on the triacetyl cellulose film had fine irregularities formed by the fine particles of polymethylmethacrylate beads. On this cured coating film, a low-refractive-index layer having a film thickness shown in Table 1 below was formed by a vacuum deposition method in the order of a SiO _x film and a MgF ₂ film to obtain each antiglare antireflection film. It was

As a comparative example to Example 2, instead of the low refractive index layer, SiO _x was 1000Å by vacuum deposition.
Anti-glare anti-reflective film formed in a uniform thickness, and MgF
Each of the antiglare antireflection films formed with ₂ having a thickness of 1000Å was prepared, and total light transmittance (T), diffuse transmittance (D), linear transmittance (PT), haze value (H = D /
T) and hardness were compared with Example 2. The results are shown in Table 3 below.

[0082]

[Table 3]

[0083]

According to the antireflection film of the present invention, a low refractive index layer having a lower refractive index than the antiglare layer is formed on the antiglare layer formed on the transparent substrate film,
And, the low refractive index layer is composed of two different layers, and the refractive index of the antiglare layer is in contact with the surface of the antiglare layer opposite to the surface in contact with the low refractive index layer. Since it has a higher refractive index than that of the layer, it reduces reflection of light at the interface between the antiglare layer and the layer in contact with the surface opposite to the surface of the low refractive index layer in contact with the antiglare layer. be able to. Therefore, the antiglare antireflection film of the present invention has an antiglare property and an excellent antireflection effect.

Further, as described above, by forming the low refractive index layer into two layers, the respective defects of the low refractive index material can be mutually eliminated. For example, when the first low-refractive index layer is a MgF ₂ film and the second low-refractive index layer is a SiO _x film, the strength of the antireflection film is increased, and the optical antireflection with excellent scratch resistance of the surface is also provided. A highly effective antiglare antireflection film can be obtained.

Further, the first low refractive index layer 5 is formed of a SiO _x film and a second
When the low refractive index layer is a MgF ₂ film, the strength of the antireflection film is increased and the adhesion to the antiglare layer is excellent,
Furthermore, an antiglare antireflection film having a high optical antireflection effect can be obtained. In addition, the antiglare / antireflection effect described above is imparted to a laminate of the antiglare / antireflection film of the present invention laminated by laminating, pasting or the like, for example, a polarizing plate or a liquid crystal display device.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a layer structure of an antiglare antireflection film of the present invention.

FIG. 2 is a cross-sectional view showing another layer structure of the antiglare antireflection film of the present invention.

FIG. 3 is a cross-sectional view showing the layer structure of a polarizing plate laminated with the antiglare antireflection film of the present invention.

FIG. 4 is a cross-sectional view showing a layer structure of a liquid crystal display device using a polarizing plate laminated with an antiglare antireflection film of the present invention.

[Explanation of symbols]

 1 Transparent Base Film 2 Antiglare Layer 3 Low Refractive Index Layer 4 First Low Refractive Index Layer 5 Second Low Refractive Index Layer 6 Mat Material 7 Antiglare Antireflection Film 8 TAC Base Film 9 Antiglare Layer 10 Low Refraction Index layer 11 First low refractive index layer 12 Second low refractive index layer 13 Polarizing element 14 TAC film 15 Liquid crystal display element

Claims (18)

[Claims] 1. An antiglare layer having a fine uneven surface is formed on the transparent substrate film directly or through another layer, and the antiglare layer is formed on the antiglare layer more than the antiglare layer. In an antireflection film formed by forming a low refractive index layer having a low refractive index, the low refractive index layer is formed by laminating two different types of first low refractive index layer and second low refractive index layer in this order. And the refractive index of the antiglare layer is higher than the refractive index of the layer in contact with the surface of the antiglare layer opposite to the surface in contact with the low refractive index layer. Anti-glare anti-reflection film. 2. The antiglare antireflection film according to claim 1, wherein the antiglare layer comprises a layer containing a binder resin as a main component. 3. The antiglare antireflection film according to claim 1, wherein either the first low refractive index layer or the second low refractive index layer is SiO _x (x: 1.8 <x <2. An antiglare antireflection film comprising: 2). 4. The anti-glare and anti-reflection film according to claim 3, wherein the first low refractive index layer with MgF _2, the second
An antiglare antireflection film, wherein the low refractive index layer is made of SiO _x . 5. The antiglare reflection film according to claim 3, wherein the first low refractive index layer is made of SiO _x and the second low refractive index layer is made of MgF _2. Prevention film. 6. The antiglare antireflection film according to claim 1, 2, 3, 4 or 5, wherein the first layer and the second layer each have a thickness of 10 to 100 nm. Anti-reflective film. 7. The antiglare antireflection film as claimed in claim 1, wherein the total film thickness of the low refractive index layers is 50 to 200 nm. Anti-glare anti-reflection film. 8. The antiglare antireflection film as claimed in claim 1, 2, 3, 4, 5, 6 or 7, wherein the low refractive index layer is formed by a vapor phase method. Dazzling anti-reflection film. 9. The antiglare antireflection film according to claim 8, wherein the vapor phase method is a plasma CVD method. 10. The method according to claim 1, 2, 3, 4, 5, 6, 7,
The antiglare antireflection film as described in 8 or 9, wherein the antiglare layer has a hard performance. 11. Claims 2, 3, 4, 5, 6, 7, 8,
In the antiglare antireflection film as described in 9 or 10, (1) an aromatic ring, (2) a halogen atom other than F, (3) S, N, as an optical molecule or atom of the binder resin.
An antiglare antireflection film comprising one or more kinds of molecules and / or atoms selected from the atom of P. 12. The method according to claim 1, 2, 3, 4, 5, 6, 7,
The antiglare antireflection film as described in 8, 9, 10 or 11, wherein the binder resin is a thermosetting resin and / or an ionizing radiation curable resin. 13. The method according to claim 1, 2, 3, 4, 5, 6, 7,
The antireflection film as described in 8, 9, 10, 11 or 12, wherein the antiglare layer has a thickness of 0.5 μm or more. 14. Claims 1, 2, 3, 4, 5, 6, 7,
In the antiglare antireflection film as described in 8, 9, 10, 11, 12 or 13, the antiglare layer contains high refractive index ultrafine particles having a refractive index of 1.5 or more higher than that of the binder resin. An antiglare antireflection film characterized by: 15. The antiglare antireflection film according to claim 14, wherein the high refractive index fine particles are ZnO or Ti.
O ₂ , Ce ₂ O ₃ , Sb ₂ O ₅ , SnO ₂ , ITO, C
An antiglare antireflection film comprising one or more kinds of fine particles selected from eO ₂ . 16. The method according to claim 1, 2, 3, 4, 5, 6, 7,
The antiglare antireflection film as described in 8, 9, 10, 11, 12, 13, 14 or 15, wherein the other layer is provided with an adhesive layer, a primer layer and / or a hard coat layer. Anti-glare anti-reflection film to be. 17. The method according to claim 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15 or 16
A polarizing plate, wherein the antiglare antireflection film as described above is laminated on a polarizing element. 18. A liquid crystal display device, wherein the polarizing plate according to claim 17 is used as a constituent element of a liquid crystal display device.