KR101871135B1 - Antireflection film, polarizing plate, and image display device - Google Patents

Abstract

And an object of the present invention is to provide an antireflection film having a low refractive index layer having a sufficiently low refractive index and having an excellent surface hardness and a uniform surface and an excellent antireflection performance. An antireflection film having a hard coat layer formed on a light-transmitting substrate and a low refractive index layer formed on the hard coat layer, wherein the low refractive index layer contains a (meth) acrylic resin, hollow silica fine particles, reactive silica fine particles, And the reactive silica fine particles in the low refractive index layer are distributed in the vicinity of the interface near the hard coat layer and / or near the interface near the hard coat layer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an antireflection film, a polarizing plate,

The present invention relates to an antireflection film, a polarizing plate and an image display device.

Image display devices such as cathode ray tube display (CRT), liquid crystal display (LCD), plasma display (PDP), electroluminescence display (ELD), field emission display (FED), touch panel, tablet PC, It is required that the image display surface in the image display surface is made less reflective by the light beam irradiated from the external light source to improve its visibility.

On the other hand, in general, by using an antireflection film having an antireflection layer formed on a light-transmitting substrate, the reflection on the image display surface of the image display device is reduced to improve the visibility.

As an antireflection film having an antireflection layer, there is known a structure in which a low refractive index layer having a refractive index lower than that of a conventional light-transmitting base is provided on the outermost surface.

The low refractive index layer should have a low refractive index in order to enhance the antireflection performance of the antireflection film, be provided on the outermost surface, have high hardness for preventing the occurrence of scratches, It is required to have excellent optical properties.

As the antireflection film formed on the outermost surface of the low refractive index layer, for example, Patent Document 1 discloses an antireflection film comprising hollow silica fine particles and a binder resin such as acrylate, An antireflection film having a low refractive index layer having a structure containing a low refractive index layer.

In recent years, however, the display quality required for an image display device has become very high, and the antireflection performance of the antireflection film is also required to be higher.

However, in the conventional antireflection film provided with the low refractive index layer containing the hollow silica fine particles, the antireflection performance can not be said to be sufficient and it can not sufficiently meet the recent demand for high display quality.

For example, Patent Document 2 discloses a method of blending a fluorine atom-containing polymer or a monomer into a material of a low refractive index layer. Since the fluorine atom-containing polymer or monomer is a material having a low refractive index, the low refractive index layer containing the fluorine atom-containing polymer or monomer can further reduce the refractive index than the low refractive index layer containing conventional hollow silica fine particles.

However, conventional low refractive index layers containing fluorine atom-containing polymers or monomers have a problem in that the hardness of the low refractive index layer becomes insufficient if these compounds are contained sufficiently to reduce the refractive index.

Therefore, there has been a demand for an antireflection film having a sufficient surface hardness and a low refractive index layer with a lower refractive index and having high antireflection performance.

Further, since such an antireflection film is usually provided on the outermost surface of an image display apparatus, it is also required to have excellent slidability.

[Prior Art Literature]

[Patent Literature]

(Patent Document 1) Japanese Patent Application Laid-Open No. 2003-292831

(Patent Document 2) Japanese Patent Application Laid-Open No. 2001-100004

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and has an object to provide an antireflection film having excellent antireflection performance, surface hardness and uniform surface, a low refractive index layer having a sufficiently low refractive index of the low refractive index layer, And an object of the present invention is to provide a polarizing plate and an image display device using the antireflection film.

The present invention relates to an antireflection film having a hard coat layer formed on a light-transmitting substrate and a low refractive index layer formed on the hard coat layer, wherein the low refractive index layer comprises a (meth) acrylic resin, hollow silica fine particles, reactive silica fine particles, And the reactive silica fine particles in the low refractive index layer are distributed in the vicinity of the interface near the hard coat layer and / or near the interface near the opposite side of the hard coat layer.

In the antireflection film of the present invention, the reactive silica fine particles in the low refractive index layer are unevenly distributed in the vicinity of the interface on the side opposite to the side of the hard coat layer, and the hard coat layer is in the state of being aligned in the interface direction It is preferable to have reactive silica fine particles.

The content of the reactive silica fine particles in the low refractive index layer is preferably 5 to 60 parts by mass based on 100 parts by mass of the (meth) acrylic resin.

The hollow silica fine particles preferably have an average particle diameter of 40 to 80 nm and a blending ratio to the (meth) acrylic resin (content of the hollow fine silica particles / content of the (meth) acrylic resin) of 0.90 to 1.60 Do.

It is preferable that the antifouling agent is localized in the vicinity of the interface on the side opposite to the hard coat layer of the low refractive index layer.

The antifouling agent is preferably a compound containing a reactive functional group and a fluorine atom and / or a silicon atom.

The (meth) acrylic resin may be at least one selected from the group consisting of pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta , A polymer or copolymer of at least one kind of monomer selected from the group consisting of trimethylolpropane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate and isocyanuric acid tri (meth) acrylate Do.

It is preferable that the low refractive index layer further contains a fluorine atom-containing resin.

The content of the reactive silica fine particles in the hard coat layer is preferably 15 to 60 parts by mass based on 100 parts by mass of the (meth) acrylic resin.

The present invention is also a polarizing plate comprising a polarizing element, wherein the polarizing plate is a polarizing plate characterized in that the above-mentioned anti-reflection film is provided on the surface of the polarizing element.

The present invention is also an image display device characterized by comprising the above-mentioned antireflection film or the above-mentioned polarizing plate.

Hereinafter, the present invention will be described in detail.

The present invention is an antireflection film in which a hard coat layer is formed on a light-transmitting substrate and a low refractive index layer is formed on the hard coat layer.

The inventors of the present invention have made intensive investigations on the antireflection film having the above-described structure. As a result, they have found that by incorporating reactive silica fine particles in a hard coat layer and containing reactive fine silica particles and hollow silica fine particles in a low refractive index layer, The reactive silica fine particles are distributed in the vicinity of the interface on the side opposite to the hard coat layer and the hollow silica fine particles in the low refractive index layer are densely packed so that the desired effect is achieved. It came.

Hereinafter, each layer constituting the antireflection film of the present invention will be described in detail.

The low refractive index layer

The low refractive index layer refers to a refractive index lower than the refractive index of a constituent other than the low refractive index layer such as a light transmitting substrate or a hard coat layer constituting the antireflection film of the present invention.

In the antireflection film of the present invention, the low refractive index layer contains (meth) acrylic resin, hollow silica fine particles, reactive silica fine particles and antifouling agent.

The hollow silica fine particles serve to lower the refractive index of the low refractive index layer while maintaining the layer strength of the low refractive index layer. In the present specification, the term "hollow-shaped silica fine particles" refers to a porous structural body containing a gas and / or a gas in the interior thereof. The porous fine structure of silica fine particles having a refractive index lowered in proportion to the occupancy of the gas relative to the original refractive index it means.

In the present invention, depending on the form, structure, aggregation state of the fine silica particles, dispersion state inside the coating film formed by using a composition for a low refractive index layer which will be described later and used for forming the low refractive index layer, Or silica fine particles capable of forming a nanoporous structure on at least a part of the surface.

In the antireflection film of the present invention, the hollow silica fine particles are contained in the low refractive index layer in a densely packed state. As a result, the surface of the low refractive index layer is excellent in uniformity, and the antireflection film of the present invention is excellent in surface hardness.

Further, the "densely packed state" means that there is almost no reactive silica fine particles to be described later between the adjacent hollow silica fine particles, thereby forming a state similar to the closest packing structure.

The reason that the hollow silica fine particles are contained in the low refractive index layer in a densely packed state is that the reactive silica fine particles contained in the low refractive index layer are present near the hard coat layer side interface of the low refractive index layer, It is presumed that it is localized in the vicinity of the interface on the opposite side. That is, the low refractive index layer is formed by applying a composition (hereinafter also referred to as a composition for a low refractive index layer) including a hollow silica fine particle, a reactive silica fine particle and a monomer component of a (meth) acrylic resin on a hard coat layer, And drying and curing the coating film. When the coating film is formed, the reactive silica fine particles contained in the coating film move to the vicinity of the interface on the side of the hard coat layer or the vicinity of the interface on the opposite side of the hard coat layer as described later. As a result, almost no reactive silica fine particles are present between the adjacent hollow fine silica particles in the formed coating film, and as a result, the hollow fine silica particles in the formed low refractive index layer become densely packed I guess.

Specific examples of the hollow silica fine particles are not particularly limited, and for example, silica fine particles produced by using the technique disclosed in Japanese Patent Application Laid-Open No. 2001-233611 are preferably used. Since hollow silica fine particles are easy to manufacture and have high hardness, when the low refractive index layer is formed by mixing with the organic binder, it becomes possible to improve the layer strength and to adjust the refractive index to be low.

In addition to the above-mentioned hollow silica fine particles, it is also possible to use a packing column, which is manufactured and used for the purpose of increasing the specific surface area, an adsorbent for adsorbing various chemicals to the porous portion of the surface, porous fine particles used for fixing the catalyst, Or a dispersion or an aggregate of hollow microparticles for the purpose of embedding in a low dielectric constant material. Specific examples thereof include colloidal silica UP series (trade name) having a structure in which fine silica particles produced by Nissan Chemical Industries, Ltd., in the form of chain, in a trade name of Nipsil or Nipgel manufactured by Nippon Silica Kogyo Co., Ltd. . Among them, those having a particle diameter within the preferable range of the present invention can be used.

The average particle diameter of the hollow fine silica particles is preferably 10 to 100 nm. When the average particle diameter of the hollow silica fine particles is within this range, excellent transparency can be imparted to the low refractive index layer. A more preferable lower limit is 40 nm, a more preferable upper limit is 80 nm, a more preferable lower limit is 45 nm, a more preferable upper limit is 75 nm, a most preferable lower limit is 50 nm, and a most preferable upper limit is 70 nm.

The average particle diameter of the hollow fine silica particles means a value measured by a dynamic light scattering method when the hollow fine silica particles are used alone. On the other hand, the average particle diameter of the hollow silica fine particles in the low refractive index layer was measured by observing the cross section of the low refractive index layer by STEM or the like, selecting 30 hollow fine silica fine particles, Is a value calculated as an average value.

The hollow silica fine particles preferably have a porosity of 1.5 to 80.0%. If it is less than 1.5%, the refractive index of the low refractive index layer can not be sufficiently lowered, and the antireflection performance of the antireflection film of the present invention may become insufficient. If it exceeds 80.0%, the strength of the hollow silica fine particles may be lowered and the strength of the entire low refractive index layer may become insufficient. The porosity of the hollow silica fine particles is more preferably 6.4% as the lower limit, more preferably 76.4% as the upper limit, more preferably 20.0% as the upper limit, and still more preferably 55.0% as the upper limit. By having the porosity in this range, the low refractive index layer can be made sufficiently low in refractive index and excellent in strength can be obtained.

The porosity of the hollow silica fine particles is measured by observing the cross section of the hollow silica fine particles by STEM or the like and measuring the thickness of the outer portion except for the diameter and the void portion thereof and determining that the hollow silica fine particles are spherical, The volume of the void portion of the shaped silica fine particles and the volume of the hollow fine silica particles when the void portion is absent are calculated to calculate the volume of the void portion of the hollow silica fine particles / The volume of hollow fine silica particles) x 100.

When a plurality of hollow silica fine particles differing in the average particle diameter and the thickness of the outer periphery portion are included in the low refractive index layer, the porosity of each hollow silica fine particle calculated by the above-mentioned method and the mixing ratio of the hollow fine silica particles (Hereinafter also referred to as "average porosity") of the hollow silica fine particles. Also in this case, it is preferable that the individual hollow silica fine particles have a porosity in the above-mentioned range.

In the antireflection film of the present invention, the hollow silica fine particles preferably have an average porosity of 10.0 to 40.0%. If it is less than 10.0%, the refractive index of the low refractive index layer can not be sufficiently lowered, and the antireflection performance of the antireflection film of the present invention may be insufficient. If it exceeds 40.0%, the strength of the hollow silica fine particles may be lowered and the strength of the entire low refractive index layer may become insufficient. A more preferable lower limit is 15.0%, and a more preferable upper limit is 35.0%. By having the porosity in this range, the low refractive index layer can be made sufficiently low in refractive index and excellent in strength can be obtained. From the viewpoint of low refractive index and strength, a more preferable lower limit of the average porosity of the hollow silica fine particles is 20.0%, and a more preferable upper limit is 30.0%.

The hollow silica fine particles preferably have a mixing ratio (content of hollow fine silica particles / content of (meth) acrylic resin) to a (meth) acrylic resin to be described later contained in the low refractive index layer of 0.90 to 1.60. If the compounding ratio is less than 0.90, the refractive index of the low refractive index layer is not sufficiently lowered, and the antireflection performance of the antireflection film of the present invention may become insufficient. If the compounding ratio exceeds 1.60, the uniformity of the surface of the low refractive index layer becomes insufficient, and the surface hardness of the antireflection film of the present invention may become insufficient. A more preferable lower limit of the compounding ratio is 1.00, and a more preferable upper limit is 1.50. Within this range, an antireflection film having excellent antireflection performance, surface uniformity and surface hardness can be obtained. Further, the surface uniformity of the low refractive index layer is increased, whereby the surface hardness (scratch resistance) is improved.

In the antireflection film of the present invention, it is preferable that the hollow silica fine particles have a dense filling structure in which two layers are laminated in the thickness direction of the low refractive index layer. By being contained in such a state, the antireflection film of the present invention can exhibit excellent transparency, surface uniformity and low refractive index.

The reactive silica fine particles are localized in the vicinity of the interface of the low refractive index layer on the side of the hard coat layer and / or on the opposite side of the hard coat layer, which will be described later, and the refractive index of the low refractive index layer is lowered, And it plays a role of increasing the hardness.

When the reactive silica fine particles are localized in the vicinity of the interface near the hard coat layer side of the low refractive index layer and in the vicinity of the interface near the opposite side of the hard coat layer, the surface hardness and the stainproofing property can be excellent.

When the reactive silica fine particles are localized in the vicinity of the interface of the hard coat layer side of the low refractive index layer, antifouling agents to be described later are distributed in the vicinity of the interface on the side opposite to the hard coat layer of the low refractive index layer, The amount of the antifouling agent present on the outermost surface increases, so that the antifouling performance of the antireflection film of the present invention is extremely excellent. On the other hand, when the reactive silica fine particles are localized in the vicinity of the interface on the side opposite to the hard coat layer of the low refractive index layer, the surface hardness of the low refractive index layer due to the localization of the reactive silica fine particles is further improved.

In addition, since the hollow silica fine particles are densely packed in the low refractive index layer as described above, the surface hardness of the low refractive index layer can be improved by the excellent surface uniformity. As a result, the anti-scratch property of the antireflection film of the present invention is excellent.

Here, the term "localized near the interface of the hard coat layer side or in the vicinity of the interface near the hard coat layer to be described later" means that the reactive silica fine particles are densely packed in the low refractive index layer (Hard coat layer side) or upward (opposite to the hard coat layer) of one hollow silica fine particle. More specifically, when the thickness of the low refractive index layer is divided into three equal parts in the cross section of the low refractive index layer and 1/3 area, 2/3 area and 3/3 area are sequentially arranged from the interface on the hard coat layer side , 70% or more of the reactive silica fine particles were contained in the 1/3 region, and that 70% or more of the reactive silica fine particles were localized in the 3/3 region in the hard coat layer side. It is judged that the reactive silica fine particles are unevenly distributed in the vicinity of the interface on the side opposite to the hard coat layer. The total amount of the reactive silica fine particles in the 1/3 region and the 3/3 region is distributed in a total amount of 70% or more, and the amounts of the reactive silica fine particles, which are ubiquitous in the 1/3 region and the 3/3 region, 3, it is determined that the reactive silica fine particles are localized in the vicinity of the interface between the hard coat layer side of the low refractive index layer and the interface near the opposite side of the hard coat layer.

The state in which such reactive silica fine particles are ubiquitous can be easily determined by observation of a cross section microscope (STEM, TEM) of the low refractive index layer when the antireflection film of the present invention is cut in the thickness direction.

It is not clear why the reactive silica fine particles are localized in the vicinity of the interface near the hard coat layer side and / or the interface near the hard coat layer in the low refractive index layer. However, for example, when the hard coat layer described later contains reactive silica fine particles, it is possible to control the localization of the reactive silica fine particles in the low refractive index layer by adjusting the addition amount of the reactive silica fine particles in the hard coat layer.

That is, when the hard coat layer does not contain reactive silica fine particles, if the low refractive index layer is formed on the hard coat layer, the reactive silica fine particles of the low refractive index layer can be localized near the hard coat layer side interface. On the other hand, when the hard coat layer contains the reactive silica fine particles in an amount of more than 25 parts by mass and 60 parts by mass or less based on 100 parts by mass of the resin component constituting the hard coat layer, The reactive silica fine particles of the low refractive index layer can be localized in the vicinity of the interface on the side opposite to the hard coat layer. When the hard coat layer contains the reactive silica fine particles in a range of 15 to 25 parts by mass with respect to 100 parts by mass of the resin component constituting the hard coat layer, the reactive silica fine particles of the low refractive index layer are added to the low refractive index layer It can be distributed in the vicinity of the interface between the hard coat layer side and the vicinity of the interface opposite to the hard coat layer.

As the reactive silica fine particles, commercially available products may be used. For example, MIBK-SDL, MIBK-SDMS, MIBK-SD (all manufactured by Nissan Chemical Industries, Ltd.), DP1021SIV, DP1039SIV, DP1117SIV Manufactured by Kasei Co., Ltd.).

The average particle diameter of the reactive silica fine particles is preferably 1 to 25 nm. When the thickness is less than 1 nm, aggregation tends to occur, and the filling degree is lowered, so that sufficient strength can not be obtained in the obtained low refractive index layer. On the other hand, when the thickness exceeds 25 nm, surface irregularities are formed in the low refractive index layer, so that sufficient strength may not be obtained. Further, the reflectance is increased, and it becomes difficult to exhibit sufficient antifouling property due to the antifouling agent to be described later.

A more preferable lower limit of the average particle diameter of the reactive silica fine particles is 5 nm, and a more preferable upper limit is 20 nm. Within this range, the low reflectance and hardness of the antireflection film of the present invention can be maintained.

In the present specification, the average particle diameter of the reactive silica fine particles means a value measured by cross-sectional observation (30 average values) such as BET method and STEM.

The content of the reactive silica fine particles in the low refractive index layer is preferably 5 to 60 parts by mass based on 100 parts by mass of a (meth) acrylic resin to be described later. If it is less than 5 parts by mass, the surface hardness of the low refractive index layer can not be made sufficiently high, and the antiscratchability of the antireflection film of the present invention may be lowered. When the amount is more than 60 parts by mass, the amount of reactive silica fine particles which are not in a ubiquitous state in the above-described low refractive index layer is increased and the hollow silica fine particles are not brought into the densely filled state described above. As a result, The uniformity may be deteriorated, and there is a possibility that the reflectance may rise. A more preferable lower limit of the content of the reactive silica fine particles is 10 parts by mass, and a more preferable upper limit is 50 parts by mass. Since the reactive silica fine particles are contained in this range, the surface hardness of the antireflection film of the present invention can be made very excellent.

The (meth) acrylic resin functions as a binder component of the hollow silica fine particles and the reactive silica fine particles described above in the low refractive index layer. Further, in the present specification, "(meth) acryl" means acryl or methacryl.

Examples of the (meth) acrylic resin include polymers and copolymers of (meth) acrylic monomers. The (meth) acrylic monomers are not particularly limited, and examples thereof include pentaerythritol tri (meth) (Meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tetra Acrylate, isocyanuric acid tri (meth) acrylate, and the like.

These (meth) acrylate monomers may be ones in which a part of the molecular skeleton thereof is modified or may be modified by addition of one or more kinds selected from the group consisting of ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, cyclic alkyl, aromatic, Can be used.

These (meth) acrylic monomers may be used alone, or two or more of them may be used in combination. These (meth) acrylic monomers satisfy the range of the refractive index as described later and are excellent in curing reactivity, and the hardness of the obtained low refractive index layer can be improved.

Among them, a (meth) acrylic resin having three or more functional groups is suitably used.

The (meth) acrylic resin (after curing) preferably has a refractive index of 1.47 to 1.53. It is practically impossible to reduce the refractive index to less than 1.47. When the refractive index exceeds 1.53, a low refractive index layer with a sufficiently low refractive index may not be obtained.

The (meth) acrylic monomer preferably has a weight average molecular weight of 250 to 1,000. If it is less than 250, the number of functional groups is decreased, and the hardness of the obtained low refractive index layer may be lowered. On the other hand, when the number-average molecular weight is more than 1,000, the functional group equivalent (the number of functional groups / the molecular weight) is generally small, so that the crosslinking density is low and a low refractive index layer with sufficient hardness can not be obtained.

The weight average molecular weight of the (meth) acrylic monomer can be determined by polystyrene conversion by gel permeation chromatography (GPC). As the solvent for the GPC moving phase, tetrahydrofuran or chloroform may be used. For the measurement column, a commercially available column of tetrahydrofuran or chloroform column may be used in combination. Examples of commercially available columns include Shodex GPC KF-801 and GPC-KF800D (all trade names, manufactured by Showa Denko K.K.). For the detector, RI (differential refractive index) detector and UV detector may be used. The weight average molecular weight can be appropriately measured by using a GPC system such as Shodex GPC-101 (manufactured by Showa Denko K.K.) using such a solvent, a column and a detector.

The low refractive index layer further contains a contaminant inhibitor.

The antireflection film of the present invention has antifouling performance because the low refractive index layer further contains the antifouling agent. Particularly when the reactive silica fine particles in the low refractive index layer are localized near the interface of the hard coat layer side, The content of the antifouling agent in the vicinity of the interface on the side opposite to the hard coat layer of the low refractive index layer becomes large, so that the antifouling performance of the antireflection film of the present invention is particularly excellent.

When the reactive silica fine particles are unevenly distributed in the vicinity of the interface on the side opposite to the hard coat layer in the low refractive index layer, the antifouling agent may be present on the side opposite to the hard coat layer of the low refractive index layer To some extent in the vicinity of the interface of the antifouling agent, and in this case, the antifouling performance of the antifouling agent can be improved to some extent. The reason why the antifouling agent is localized in the vicinity of the interface on the side opposite to the hard coat layer is not clear. However, for example, when a coating film formed on the hard coat layer is formed, It is presumed that the migration of the reactive silica fine particles is influencing the movement of the fine particles.

Thus, in the antireflection film of the present invention, the antifouling agent is contained in the low refractive index layer, so that the antifouling performance is excellent.

The antifouling agent is preferably a compound containing a reactive functional group and a fluorine atom and / or a silicon atom. By incorporating such a pollution preventive agent, it is possible to further improve the antifouling performance of the low refractive index layer to be formed.

As the compound containing a reactive functional group and a fluorine atom, for example, a reactive fluorine compound, in particular, a fluorine-containing monomer having an ethylenic unsaturated bond can be widely used. More specifically, for example, fluoroolefins For example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluorobutadiene, perfluoro-2,2-dimethyl-1,3-dioxol and the like.

Also, examples thereof include 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- (perfluorobutyl) ethyl (Meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate compounds having a fluorine atom in the molecule such as methyl (meth) acrylate and methyl (meth) acrylate; (Meth) acrylic acid having at least three fluorine atoms in the molecule and having from 1 to 14 carbon atoms, a fluoroalkyl group, a fluorocycloalkyl group or a fluoroalkylene group and at least two (meth) acryloyloxy groups, Ester compounds and the like.

Fluoropolymers and oligomers having fluorinated alkylene groups in the main chain, fluorinated polymers having fluorinated alkylene groups and fluorinated alkyl groups in the main chain and side chains, and oligomers can also be used. Among them, a fluorinated polymer having a fluorinated alkylene group and a fluorinated alkyl group in the main chain and the side chain is particularly suitably used in view of difficulty of bleeding out from the low refractive index layer.

Examples of the compound containing a reactive functional group and a silicon atom include a reactive silicone compound.

Specific examples thereof include (poly) dimethylsiloxane, (poly) dimethylsiloxane, (poly) diethylsiloxane, (poly) diphenylsiloxane, (poly) methylphenylsiloxane, alkyl (Meth) acryl-containing silicon, phenoxy group-containing silicon, phenol group-containing silicon, fluorine-containing silicon, fluorine-containing silicon, fatty acid ester-modified silicone, methyl hydrogen silicone, silanol group- Amino-modified silicone, carboxy-modified silicone, carbinol-modified silicone, epoxy-modified silicone, mercapto-modified silicone, fluorine-modified silicone, polyether-modified silicone and the like. Among them, a compound having a dimethylsiloxane structure is preferable because it is difficult to cause a problem of bleeding out from the low refractive index layer.

Examples of the compound containing a reactive functional group and a fluorine atom and a silicon atom include a silicon-containing vinylidene fluoride copolymer obtained by reacting the reactive fluorine compound with the reactive silicone compound.

The content of the antifouling agent is appropriately determined according to the antifouling property of the aimed low refractive index layer, but it is preferably 1 to 20 parts by mass per 100 parts by mass of the total of the hollow silica fine particles and the (meth) acrylic resin Do. If the amount is less than 1 part by mass, sufficient stainproofing performance may not be imparted to the low refractive index layer to be formed, and if it exceeds 20 parts by mass, the added antifouling agent may bleed out from the low refractive index layer. Further, the effect equivalent to the addition of the antifouling agent is not exhibited, and the production cost is increased, and the hardness and appearance of the obtained low refractive index layer are lowered, and the reflectance may be increased. A more preferable lower limit of the content of the antifouling agent is 2 parts by mass, and a more preferable upper limit is 15 parts by mass.

As the antifouling agent, a compound containing a reactive functional group and a compound containing a fluorine atom and / or a silicon atom together with a compound containing no reactive functional group may be added and used.

In the antireflection film of the present invention, it is preferable that the refractive index of the low refractive index layer is less than 1.45. If it is 1.45 or more, the antireflection performance of the antireflection film of the present invention becomes insufficient, and the display quality of a high level in a recent image display apparatus can not be satisfied. A more preferable lower limit is 1.25, and a more preferable upper limit is 1.43.

The film thickness (nm) (d _A ) of the low refractive index layer is represented by the following formula (I):

_{d A = mλ / (4n A} ) (I)

(Wherein,

n _A represents the refractive index of the low refractive index layer,

m represents a positive odd number, preferably 1,

lambda is a wavelength, preferably a value in the range of 480 to 580 nm)

Is satisfied.

Further, in the present invention, the low refractive index layer has the following formula (II):

_{120 <n A d A <145} (II)

Is preferable in terms of low reflectance.

It is preferable that the low refractive index layer has a haze value of 1% or less. If it exceeds 1%, the light transmittance of the antireflection film of the present invention is lowered, which may cause deterioration of the display quality of the image display apparatus. More preferably, it is 0.5% or less. In the present specification, the haze value is a value obtained in accordance with JIS K7136.

The low refractive index layer preferably has a hardness of not less than H, and more preferably not less than 2H, according to a pencil hardness test according to JIS K5600-5-4 (1999).

It is preferable that the low refractive index layer is free from scratches in an abrasion resistance test in which a friction load of 300 g / cm &lt; ² &gt;

The low refractive index layer is obtained by preparing a composition for a low refractive index layer containing the hollow silica fine particles, the reactive silica fine particles, the monomer component of the (meth) acrylic resin, the antifouling agent, and the like, using the coating composition for low refractive index layer .

The composition for the low refractive index layer preferably contains a solvent.

The solvent is preferably a mixed solvent of methyl isobutyl ketone (MIBK) and propylene glycol monomethyl ether (PGME) or propylene glycol monomethyl ether acetate (PGMEA). The use of such a mixed solvent makes it possible to appropriately form the low refractive index layer having the above-mentioned structure because the drying time of the solvent contained therein is different.

The mixing ratio of MIBK and PGME or PGMEA in the mixed solvent is preferably (MIBK / PGME or PGMEA) = (95/5) to (30/70) by mass ratio. By satisfying the mixing ratio in the above range, it becomes possible to form the low refractive index layer having the above-mentioned structure particularly properly. And more preferably (80/20) to (40/60).

The composition for the low refractive index layer may contain other solvent as long as it does not inhibit the formation of the low refractive index layer having the above-described structure. Such other solvents include, for example, alcohols such as methanol, ethanol, propanol, isopropanol, n-butanol, iso-butanol, t-butanol and benzyl alcohol; Ketones such as acetone, methyl ethyl ketone, cyclohexanone, heptanone, diisobutyl ketone and diethyl ketone; Esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate and PGMEA; Aliphatic hydrocarbons such as hexane and cyclohexane; Halogenated hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride; Aromatic hydrocarbons such as benzene, toluene and xylene; Amides such as dimethylformamide, dimethylacetamide and n-methylpyrrolidone; Ethers such as diethyl ether, dioxane and tetrahydrofuran; And ether alcohol such as 1-methoxy-2-propanol.

Further, the composition for the low refractive index layer may further contain other components as necessary.

Examples of the other components include photopolymerization initiators, leveling agents, polymerization accelerators, viscosity regulators, antistatic agents, antistatic agents, ultraviolet absorbers, and resins (monomers, oligomers, polymers) other than those described above.

When the composition for a low refractive index layer contains a resin system having a radically polymerizable unsaturated group, the photopolymerization initiator may be, for example, acetophenone (commercially available under the trade name Irgacure 184 (BASF) Cyclohexyl-phenyl-ketone), benzophenone, thioxanthone, benzoin, benzoin methyl ether, etc. These may be used alone, or two or more of them may be used in combination do.

When the composition for a low refractive index layer contains a resin system having a cationic polymerizable functional group, examples of the photopolymerization initiator include an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a metallocene compound, And sulfonic acid esters. These may be used alone, or two or more of them may be used in combination. Specific examples thereof include Irgacure 907, Irgacure 369, Irgacure 379, Irgacure 819, Irgacure 127, Irgacure 500, Irgacure 754 and Irgacure 250 manufactured by BASF. , Irgacure 1800, Irgacure 1870, Irgacure OXE01, DAROCUR TPO, DAROCUR1173; SpeedcureMBB, SpeedcurePBZ, SpeedcureITX, SpeedcureCTX, SpeedcureEDB, Esacure ONE, Esacure KIP150, Esacure KTO46 manufactured by Nippon Seibe Hagner; KAYACURE DETX-S, KAYACURE CTX, KAYACURE BMS and KAYACURE DMBI manufactured by Nippon Kayaku Co., Ltd. Among these, Irgacure 369, Irgacure 127, Irgacure 907, Esacure ONE, SpeedcureMBB, SpeedcurePBZ, and KAYACURE DETX-S are preferable.

Particularly preferred is 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2- Methyl-propan-1-one), Irgacure 184 (1-hydroxy-cyclohexyl-phenyl-ketone manufactured by BASF). 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 solid content of the resin component contained in the coating composition for low refractive index layer.

As the leveling agent, the polymerization promoter, the viscosity adjusting agent, the antistatic agent, the antistatic agent, the ultraviolet absorber, and the resin (monomer, oligomer, polymer) other than those described above, known ones may be used.

The method for producing the composition for a low refractive index layer is not particularly limited and examples of the hollow fine silica particles, the reactive silica fine particles, the monomer components of the (meth) acrylic resin and the antifouling agent and the solvent, And an initiator. For the mixing, a known method such as a paint shaker or a bead mill can be used.

The composition for the low refractive index layer can be formed by drying a coating film formed by applying the composition for a low refractive index layer on a hard coat layer described later and curing the coating film by irradiation with ionizing radiation and / or heating.

Preferable drying conditions of the coating film are 40 to 80 DEG C for 10 seconds to 2 minutes. By drying the coating film under such conditions, it becomes possible to appropriately form the low refractive index layer having the above-described structure.

The method for applying the composition for a low refractive index layer is not particularly limited and examples of the coating method include a spin coating method, a dipping method, a spraying method, a gravure coating method, a die coating method, a bar coating method, a roll coater method, And the like.

Hard coat layer

The antireflection film of the present invention has a hard coat layer between the light-transmitting substrate and the low refractive index layer.

In the present specification, the term "hard coat layer" means a hardness of not less than 2H in the pencil hardness test specified by JIS K5600-5-4 (1999). The pencil hardness is more preferably 3H or more. In addition, the hard coat layer preferably has a film thickness (at the time of curing) of 1 to 30 占 퐉, more preferably 2 to 15 占 퐉.

In the antireflection film of the present invention, it is preferable that the hard coat layer contains reactive silica fine particles. The reactive silica fine particles in the low refractive index layer described above are localized in the vicinity of the interface on the side opposite to the hard coat layer because the hard coat layer contains the reactive silica fine particles.

The reactive silica fine particles include the same ones as the reactive silica fine particles in the low refractive index layer described above.

The content of the reactive silica fine particles in the hard coat layer is preferably 15 to 60 parts by mass with respect to 100 parts by mass of the resin component constituting the hard coat layer. If it is less than 15 parts by mass, the hardness of the hard coat layer may become insufficient. If it exceeds 60 parts by mass, the adhesion with the light-transmitting substrate and the adhesion with the low refractive index layer are deteriorated, The total light transmittance may be lowered or the haze may be increased. A more preferred lower limit is 20 parts by mass, and a more preferable upper limit is 55 parts by mass.

The hard coat layer preferably has reactive silica fine particles contained in a state of being aligned in the direction of the interface from the vicinity of the interface on the side of the low refractive index layer. By having the reactive silica fine particles aligned in this way, it is possible to more suitably obtain the low refractive index layer having the above-described structure.

Here, the "state aligned in the direction of the interface from the vicinity of the interface on the low refractive index layer" means a state in which the reactive silica fine particles are aligned adjacent to each other along the interface direction in the vicinity of the interface with the low refractive index layer of the hard coat layer The uppermost portion of the reactive silica fine particles is in contact with the interface with the low refractive index layer of the hard coat layer and is aligned along the interface in the state of being adjacent to each other (Fig. 1).

The hard coat layer preferably also contains reactive silica fine particles randomly contained in the above-mentioned aligned state.

The hard coat layer may be formed by a composition for the hard coat layer containing the reactive silica fine particles and a resin and other optional components.

As the resin, transparency is suitably used. Specifically, an ionizing radiation curable resin, an ionizing radiation curable resin, and a solvent drying type resin (a resin to be cured by ultraviolet rays or electron beams A resin which is a coating film only by drying a solvent), or a thermosetting resin. The ionizing radiation-curable resin is preferably used.

Specific examples of the ionizing radiation curable resin include those having an acrylate-based functional group, for example, polyfunctional epoxy resins such as polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, polyhydric alcohols (Meth) allylate, and oligomers or prepolymers of the compounds. In addition, the (meth) acrylic resin used in the low refractive index layer is also used for the hard coat layer, and among them, a (meth) acrylic resin having three or more functional groups is preferable.

When the ionizing radiation curable resin is used as an ultraviolet curable resin, it is preferable to use a photopolymerization initiator.

Examples of the photopolymerization initiator include acetophenones, benzophenones, meihyl benzoyl benzoates,? -Amyl oxime esters, tetramethyl thiuram monosulfide, thioxanthones and the like. Preferably, it is Irgacure 184 (1-hydroxy-cyclohexyl-phenyl-ketone manufactured by BASF).

It is also preferable to use a mixture of photosensitizer. Specific examples thereof include, for example, n-butylamine, triethylamine, poly-n-butylphosphine and the like.

A non-reactive polymer may be used in admixture with the ionizing radiation curable resin. Examples of the non-reactive polymer include polyacrylic acid, polymethacrylic acid, polyacrylate, polymethacrylate, polyolefin, polystyrol, polyamide, polyimide, polyvinyl chloride, polyvinyl alcohol, polyvinyl butyrate Polycarbonate, and the like. By adding these non-reactive polymers, curling can be suppressed.

Examples of the thermosetting resin include phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine- Silicon resin, and polysiloxane resin.

When the thermosetting resin is used, a curing agent such as a crosslinking agent and a polymerization initiator, a polymerization accelerator, a solvent, a viscosity adjuster and the like may be further added, if necessary.

The hard coat layer is formed by applying a composition for a hard coat layer prepared by using each of the above-described materials onto a light-transmitting base material, drying the coating film if necessary, and curing it by ionizing radiation or heating .

The method for producing the composition for a hard coat layer, the method for forming a coating film, and the like may be the same methods as the above-mentioned low refractive index layer.

The hard coat layer may also contain a hardness and low-curling material such as a known antistatic agent and a high refractive index agent.

Light-transmitting substrate

The antireflection film of the present invention has a light-transmitting substrate.

The light-transmitting substrate preferably has smoothness and heat resistance, and is excellent in mechanical strength. Specific examples of the material forming the light-transmitting substrate include, for example, a polyester (polyethylene terephthalate, polyethylene naphthalate), cellulose triacetate, cellulose diacetate, cellulose acetate butyrate, polyester, polyamide, polyimide, poly (PMMA), polyurethane or the like, such as polyether sulfone, polysulfone, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate . Preferable examples include polyester (polyethylene terephthalate, polyethylene naphthalate) and cellulose triacetate.

It is preferable to use the thermoplastic resin as a flexible film-shaped body, and depending on the use form requiring curability, it is possible to use a plate of these thermoplastic resins, or a plate- May be used.

In addition, examples of the light-transmitting substrate include an amorphous olefin polymer (COP) film having an alicyclic structure. This is a base material in which a norbornene polymer, a monocyclic cycloolefin polymer, a cyclic conjugated diene polymer, a vinyl alicyclic hydrocarbon polymer and the like are used, for example, Zeonex or Zeonoa manufactured by Nippon Zeon Co., Ltd. (norbornene Sumitol FS-1700 manufactured by Sumitomo Bakelite Co., Ltd., Atton (modified norbornene-based resin) manufactured by JSR Corporation, ARMEL (cyclic olefin copolymer) manufactured by Mitsui Chemical Co., Ltd., Topas manufactured by Ticona And Omit-OZ-1000 series (alicyclic acrylic resin) manufactured by Hitachi Chemical Co., Ltd., and the like.

Further, FV series (low refractive index, low light modulus film) manufactured by Asahi Kasei Chemicals Co., Ltd. is also preferable as an alternative substrate of triacetyl cellulose.

The thickness of the light-transmitting substrate is preferably 3 to 300 占 퐉, more preferably, the lower limit is 20 占 퐉 and the upper limit is 100 占 퐉. In the case where the light-transmitting base material is in the form of a plate, the thickness may exceed the thickness of these materials. In forming the above-mentioned hard coat layer or the like on the light-transmitting base material, in addition to physical treatments such as corona discharge treatment and oxidation treatment, coating of an anchor agent or a primer may be applied in advance in order to improve adhesion .

The antireflection film of the present invention having a structure in which the hard coat layer is formed between the light-transmitting base material and the low refractive index layer includes a known antistatic agent and a binder resin between the hard coat layer and the light- The antistatic layer may be formed.

Further, the antireflection film of the present invention may comprise, as an optional layer, another hard coat layer, a contamination preventing layer, a high refractive index layer, a medium refractive index layer, or the like which is different from the above-mentioned hard coat layer. The antifouling layer, the high refractive index layer and the medium refractive index layer may be prepared by preparing a composition containing commonly used antifouling agents, a high refractive index agent, a high refractive index agent, a low refractive index agent and a resin, .

The total light transmittance of the antireflection film of the present invention is preferably 90% or more. If it is less than 90%, there is a possibility that the color reproducibility and visibility are impaired when mounted on the display surface. The total light transmittance is more preferably 93% or more, and still more preferably 95% or more.

The haze of the antireflection film of the present invention is preferably less than 1%, more preferably less than 0.5%.

The method for producing an antireflection film of the present invention is a method for producing an antireflection film comprising the steps of applying a composition for a hard coat layer on a light transmitting substrate to form a hard coat layer and applying the composition for a low refractive index layer to the hard coat layer, And a step of forming a layer.

The method of forming the hard coat layer and the low refractive index layer is as described above.

The antireflection film of the present invention can be a polarizing plate by providing the antireflection film of the present invention on the surface of the polarizing element on the side opposite to the side where the low refractive index layer is present in the antireflection film. Such a polarizing plate is also one of the present invention.

The polarizing element is not particularly limited, and examples thereof include a polyvinyl alcohol film, a polyvinyl formal film, a polyvinyl acetal film, and an ethylene-vinyl acetate copolymerization system saponified film which are dyed and stretched by iodine or the like.

In the lamination treatment of the polarizing element and the antireflection film of the present invention, the saponification treatment is preferably performed on the light-transmitting substrate (preferably, triacetyl cellulose film). By the saponification treatment, the adhesiveness is improved and an antistatic effect can be obtained.

The present invention is also an image display device comprising the antireflection film or the polarizing plate. The image display device may be an image display device such as an LCD, PDP, FED, ELD (organic EL, inorganic EL), CRT, touch panel, tablet PC,

The LCD includes a transmissive display body and a light source device for irradiating the transmissive display body from the back face. When the image display apparatus of the present invention is an LCD, the antireflection film of the present invention or the polarizing plate of the present invention is formed on the surface of the transmissive display body.

When the present invention is a liquid crystal display device having the antireflection film, the light source of the light source device is irradiated from the lower side of the optical laminate. Further, in the STN type liquid crystal display device, a retardation plate may be inserted between the liquid crystal display element and the polarizing plate. An adhesive layer may be provided between each layer of the liquid crystal display device, if necessary.

The PDP includes a front glass substrate (electrodes are formed on the front surface), a rear glass substrate (electrodes and minute grooves are disposed on the front glass substrate with a discharge gas sealed therebetween so as to oppose the front glass substrate, Green, and blue phosphor layers are formed). When the image display apparatus of the present invention is a PDP, the above-mentioned antireflection film may be provided on the surface of the surface glass substrate or on the front surface plate (glass substrate or film substrate) thereof.

The image display device includes an ELD device for depositing zinc sulfide, a diamine material, and a light emitting material, which emit light when a voltage is applied, on a glass substrate and controlling the voltage applied to the substrate to perform display, Or an image display device such as a CRT that generates a visible image of the image. In this case, the above-mentioned anti-reflection film is provided on the outermost surface of each display device or on the surface of its front face plate.

The image display apparatus of the present invention can be used in all cases for display on a television, a computer, a word processor, or the like. In particular, it can be appropriately used on the surface of a high-precision image display such as a CRT, a touch panel, a tablet PC, an electronic paper, a liquid crystal panel, a PDP, an ELD, and a FED.

The antireflection film of the present invention is excellent in surface hardness because the low refractive index layer has reactive silica fine particles unevenly distributed in the vicinity of the surface thereof. Further, in the conventional antireflection film, the existence of minute irregularities on the surface of the low refractive index layer was one of the reasons for the poor scratch resistance. However, the low refractive index layer having the above structure is a state in which the hollow silica fine particles are densely packed So that it has a very uniform surface. Thus, the antireflection film of the present invention has excellent surface hardness. Further, in the antireflection film of the present invention, since the low refractive index layer is mainly composed of the hollow silica fine particles and the reactive silica fine particles, the refractive index can be made sufficiently low and excellent antireflection performance can be obtained.

Therefore, the antireflection film of the present invention can be applied to various fields such as a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), a field emission display (FED) , A tablet PC, an electronic paper, and the like.

1 is a microscope photograph of a cross section of an antireflection film according to Example 1. Fig.
2 is a microphotograph of a section of the antireflection film according to Example 7. Fig.
3 is a microphotograph of a section of the antireflection film of Comparative Example 1. Fig.
4 is a microphotograph of a cross section of the antireflection film of Comparative Example 2. Fig.

The content of the present invention will be explained by the following examples, but the content of the present invention is not limited to these embodiments. Unless otherwise noted, "parts" and "%" are on a mass basis. Unless otherwise stated, each component amount is a solid amount.

(Preparation of composition (1) for hard coat layer)

The components shown below were mixed to prepare a composition (1) for a hard coat layer.

10 parts by mass of reactive silica fine particles (Z7537, product of JSR, solid content 50%, content of reactive silica fine particles 60%)

Urethane acrylate (UV1700B, manufactured by Nippon Gosei Co., Ltd., 10-function) 5.7 parts by mass

0.6 mass parts of a polymerization initiator (Irgacure 184; BASF)

Methyl ethyl ketone 3.3 parts by mass

2.3 parts by mass of methyl isobutyl ketone

The solid content ratio of the leveling agent in the hard coat layer composition (1) was 0.10%.

(Preparation of composition (2) for hard coat layer)

The components shown below were mixed to prepare a composition (2) for a hard coat layer.

5 parts by mass of polyester acrylate (Aronix M-9050, manufactured by Toagosei Co., Ltd., trifunctional)

11 parts by mass of urethane acrylate (UV1700B, manufactured by Nippon Gosei Co., Ltd., 10 parts)

0.5 parts by mass of a polymerization initiator (Irgacure 184; BASF)

10 parts by mass of methyl ethyl ketone

The solid content ratio of the leveling agent in the hard coat layer composition (2) was 0.10%.

(Preparation of composition (3) for hard coat layer)

The components shown below were mixed to prepare a hard coat layer composition (3).

4 parts by mass of reactive silica fine particles (Z7537, product of JSR, solid content 50%, content of reactive silica fine particles 60%)

Urethane acrylate (UV1700B, 10 parts by Nippon Gosei Co., Ltd.) 5.7 parts by mass

0.6 mass parts of a polymerization initiator (Irgacure 184; BASF)

Methyl ethyl ketone 3.3 parts by mass

2.3 parts by mass of methyl isobutyl ketone

The solid content ratio of the leveling agent in the hard coat layer composition (3) was 0.10%.

(Preparation of composition (1) for low refractive index layer)

The components shown below were mixed to prepare a composition (1) for a low refractive index layer.

(Solid content of the hollow silica fine particles: 20 mass% solution; methyl isobutyl ketone, average particle diameter: 55 nm, average porosity: 23.3%) 0.8 mass parts

0.05 parts by mass of pentaerythritol triacrylate (PETA)

0.05 parts by mass of dipentaerythritol hexaacrylate (DPHA)

0.1 mass parts of reactive silica fine particles (solids of the above reactive silica fine particles: 30 mass% solution; methyl isobutyl ketone, average particle diameter: 12 nm)

Pollution inhibitor (X-22-164E, manufactured by Shinetsu Chemical Co., Ltd.) 0.01 part by mass

0.01 part by mass of a polymerization initiator (IRGACURE 127; BASF)

MIBK 3 parts by mass

PGME 2 parts by mass

(Preparation of composition (2) for low refractive index layer)

The components shown below were mixed to prepare a composition (2) for a low refractive index layer.

(Solid content of the hollow silica fine particles: 20 mass% solution; methyl isobutyl ketone, average particle diameter: 60 nm, average porosity: 29.6%) 0.8 mass parts

0.1 part by mass of pentaerythritol triacrylate (PETA)

0.1 mass parts of reactive silica fine particles (solids of the above reactive silica fine particles: 30 mass% solution; methyl isobutyl ketone, average particle diameter: 12 nm)

(RS-74, manufactured by DIC, 20 mass% solution; methyl ethyl ketone) 0.01 mass part

Pollution inhibitor (TU2225, manufactured by JSR Corporation, 15 mass% solution; methyl isobutyl ketone) 0.01 mass part

0.01 part by mass of a polymerization initiator (IRGACURE 127; BASF)

MIBK 3 parts by mass

PGME 2 parts by mass

(Preparation of composition (3) for low refractive index layer)

The components shown below were mixed to prepare a composition (3) for a low refractive index layer.

(Solid content of the hollow silica fine particles: 20 mass% solution; methyl isobutyl ketone, average particle diameter: 55 nm, average porosity: 23.3%) 0.8 mass parts

0.08 parts by mass of pentaerythritol triacrylate (PETA)

0.08 part by mass of dipentaerythritol hexaacrylate (DPHA)

0.1 mass parts of reactive silica fine particles (solids of the above reactive silica fine particles: 30 mass% solution; methyl isobutyl ketone, average particle diameter: 12 nm)

Pollution inhibitor (X-22-164E, manufactured by Shinetsu Chemical Co., Ltd.) 0.01 part by mass

0.01 part by mass of a polymerization initiator (IRGACURE 127; BASF)

MIBK 3 parts by mass

PGME 2 parts by mass

(Preparation of composition (4) for low refractive index layer)

The components shown below were mixed to prepare a composition (4) for a low refractive index layer.

(Solid content of the hollow silica fine particles: 20 mass% solution; methyl isobutyl ketone, average particle diameter: 60 nm, average porosity: 29.6%) 0.8 mass parts

0.17 parts by mass of pentaerythritol triacrylate (PETA)

0.2 mass parts of reactive silica fine particles (solid content of the reactive silica fine particles: 30 mass% solution; methyl isobutyl ketone, average particle diameter: 12 nm)

(RS-74, manufactured by DIC, 20 mass% solution; methyl ethyl ketone) 0.01 mass part

Pollution inhibitor (TU2225, manufactured by JSR Corporation, 15 mass% solution; methyl isobutyl ketone) 0.01 mass part

0.01 part by mass of a polymerization initiator (IRGACURE 127; BASF)

MIBK 3 parts by mass

PGME 2 parts by mass

(Preparation of composition (5) for low refractive index layer)

The components shown below were mixed to prepare a composition (5) for a low refractive index layer.

(Solid content of the hollow silica fine particles: 20 mass% solution; methyl isobutyl ketone, average particle diameter: 60 nm, average porosity: 29.6%) 0.8 mass parts

0.1 part by mass of pentaerythritol triacrylate (PETA)

0.02 mass parts of reactive silica fine particles (solid content of the reactive silica fine particles: 30 mass% solution; methyl isobutyl ketone, average particle diameter: 12 nm)

(RS-74, manufactured by DIC, 20 mass% solution; methyl ethyl ketone) 0.01 mass part

Pollution inhibitor (TU2225, manufactured by JSR Corporation, 15 mass% solution; methyl isobutyl ketone) 0.01 mass part

0.01 part by mass of a polymerization initiator (IRGACURE 127; BASF)

MIBK 3 parts by mass

PGME 2 parts by mass

(Preparation of composition (6) for low refractive index layer)

The components shown below were mixed to prepare a composition (6) for a low refractive index layer.

(Solid content of the hollow silica fine particles: 20 mass% solution; methyl isobutyl ketone, average particle diameter: 55 nm, average porosity: 23.3%) 0.8 mass parts

0.05 parts by mass of pentaerythritol triacrylate (PETA)

0.05 parts by mass of dipentaerythritol hexaacrylate (DPHA)

0.1 mass parts of reactive silica fine particles (solids of the above reactive silica fine particles: 30 mass% solution; methyl isobutyl ketone, average particle diameter: 12 nm)

(RS-74, manufactured by DIC, 20 mass% solution; methyl ethyl ketone) 0.01 mass part

Pollution inhibitor (TU2225, manufactured by JSR Corporation, 15 mass% solution; methyl isobutyl ketone) 0.01 mass part

0.01 part by mass of a polymerization initiator (IRGACURE 127; BASF)

MIBK 4 parts by mass

PGMEA 1 part by mass

(Preparation of composition (7) for low refractive index layer)

The components shown below were mixed to prepare a composition (7) for a low refractive index layer.

(Solid content of the hollow silica fine particles: 20 mass% solution; methyl isobutyl ketone, average particle diameter: 60 nm, average porosity: 29.6%) 0.8 mass parts

0.2 parts by mass of pentaerythritol triacrylate (PETA)

0.1 mass parts of reactive silica fine particles (solids of the above reactive silica fine particles: 30 mass% solution; methyl isobutyl ketone, average particle diameter: 12 nm)

(RS-74, manufactured by DIC, 20 mass% solution; methyl ethyl ketone) 0.01 mass part

Pollution inhibitor (TU2225, manufactured by JSR Corporation, 15 mass% solution; methyl isobutyl ketone) 0.01 mass part

0.01 part by mass of a polymerization initiator (IRGACURE 127; BASF)

MIBK 3 parts by mass

PGME 2 parts by mass

(Preparation of composition (8) for low refractive index layer)

The components shown below were mixed to prepare a composition (8) for a low refractive index layer.

(Solid content of the hollow silica fine particles: 20 mass% solution; methyl isobutyl ketone, average particle diameter: 60 nm, average porosity: 29.6%) 0.8 mass parts

0.1 part by mass of pentaerythritol triacrylate (PETA)

0.25 parts by mass of reactive silica fine particles (solid content of the reactive silica fine particles: 30 mass% solution; methyl isobutyl ketone, average particle diameter: 12 nm)

(RS-74, manufactured by DIC, 20 mass% solution; methyl ethyl ketone) 0.01 mass part

Pollution inhibitor (TU2225, manufactured by JSR Corporation, 15 mass% solution; methyl isobutyl ketone) 0.01 mass part

0.01 part by mass of a polymerization initiator (IRGACURE 127; BASF)

MIBK 3 parts by mass

PGME 2 parts by mass

(Preparation of composition (9) for low refractive index layer)

The components shown below were mixed to prepare a composition (9) for a low refractive index layer.

(Solid content of the hollow silica fine particles: 20 mass% solution; methyl isobutyl ketone, average particle diameter: 60 nm, average porosity: 29.6%) 0.8 mass parts

0.1 part by mass of pentaerythritol triacrylate (PETA)

0.22 mass parts of reactive silica fine particles (solid content of the reactive silica fine particles: 30 mass% solution; methyl isobutyl ketone, average particle diameter: 12 nm)

(RS-74, manufactured by DIC, 20 mass% solution; methyl ethyl ketone) 0.01 mass part

Pollution inhibitor (TU2225, manufactured by JSR Corporation, 15 mass% solution; methyl isobutyl ketone) 0.01 mass part

0.01 part by mass of a polymerization initiator (IRGACURE 127; BASF)

MIBK 3 parts by mass

PGME 2 parts by mass

(Preparation of composition (10) for low refractive index layer)

(10) for a low refractive index layer was prepared by mixing the components shown below.

(Solid content of the hollow silica fine particles: 20 mass% solution; methyl isobutyl ketone, average particle diameter: 60 nm, average porosity: 29.6%) 0.8 mass parts

0.1 part by mass of pentaerythritol triacrylate (PETA)

Reactive fine silica particles (solid content of the reactive silica fine particles: 30 mass% solution; methyl isobutyl ketone, average particle diameter: 12 nm) 0.01 mass part

(RS-74, manufactured by DIC, 20 mass% solution; methyl ethyl ketone) 0.01 mass part

Pollution inhibitor (TU2225, manufactured by JSR Corporation, 15 mass% solution; methyl isobutyl ketone) 0.01 mass part

0.01 part by mass of a polymerization initiator (IRGACURE 127; BASF)

MIBK 3 parts by mass

PGME 2 parts by mass

(Preparation of composition (11) for low refractive index layer)

The components shown below were mixed to prepare a composition (11) for a low refractive index layer.

(Solid content of the hollow silica fine particles: 20 mass% solution; methyl isobutyl ketone, average particle diameter: 55 nm, average porosity: 23.3%) 0.8 mass parts

0.05 parts by mass of pentaerythritol triacrylate (PETA)

0.05 parts by mass of dipentaerythritol hexaacrylate (DPHA)

0.1 mass parts of reactive silica fine particles (solids of the above reactive silica fine particles: 30 mass% solution; methyl isobutyl ketone, average particle diameter: 12 nm)

(RS-74, manufactured by DIC, 20 mass% solution; methyl ethyl ketone) 0.01 mass part

Pollution inhibitor (TU2225, manufactured by JSR Corporation, 15 mass% solution; methyl isobutyl ketone) 0.01 mass part

0.01 part by mass of a polymerization initiator (IRGACURE 127; BASF)

MIBK 1 part by mass

MEK 4 parts by mass

(Example 1)

The composition for hard coat layer (1) was applied to one side of a cellulose triacetate film (thickness 80 占 퐉) at a wet weight of 30 g / m ² (dry weight 15 g / m ² ). Dried at 50 캜 for 30 seconds, and irradiated with ultraviolet rays of 50 mJ / cm ² to form a hard coat layer.

Subsequently, the composition (1) for a low refractive index layer was coated on the formed hard coat layer so as to have a thickness of 0.1 mu m after drying (25 DEG C x 30 seconds - 70 DEG C x 30 seconds). Then, the film was cured by ultraviolet irradiation at an irradiation dose of 192 mJ / m ² using an ultraviolet irradiator (a light source H valve manufactured by Fusion UV System Japan) to obtain an antireflection film. The film thickness was adjusted so that the minimum value of the reflectance was close to the wavelength of 550 nm.

In the low refractive index layer of the obtained antireflection film, the compounding ratio of the hollow fine silica particles to the (meth) acrylic resin (content of the hollow fine silica particles / content of the (meth) acrylic resin) was 1.60.

(Example 2)

An antireflection film was obtained in the same manner as in Example 1 except that the composition for a low refractive index layer (2) was used in place of the composition for a low refractive index layer (1).

In the low refractive index layer of the obtained antireflection film, the compounding ratio of the hollow fine silica particles to the (meth) acrylic resin (content of the hollow fine silica particles / content of the (meth) acrylic resin) was 1.60.

(Example 3)

A hard coat layer was formed by applying a hard coat layer composition (2) with a wet weight of 30 g / m ² (dry weight 15 g / m ² ) on one side of a cellulose triacetate film (thickness 80 탆) An antireflection film was obtained in the same manner as in Example 1 except that the composition for a low refractive index layer (2) was used on the coat layer to form a low refractive index layer.

(Example 4)

An antireflection film was obtained in the same manner as in Example 1 except that the composition for a low refractive index layer (3) was used in place of the composition for a low refractive index layer (1).

In the low refractive index layer of the obtained antireflection film, the compounding ratio of the hollow fine silica particles to the (meth) acrylic resin (the content of the hollow fine silica particles / the content of the (meth) acrylic resin) was 1.00.

(Example 5)

An antireflection film was obtained in the same manner as in Example 1 except that the composition for a low refractive index layer (4) was used in place of the composition for a low refractive index layer (1).

In the obtained low refractive index layer of the antireflection film, the compounding ratio of the hollow fine silica particles to the (meth) acrylic resin (the content of the hollow fine silica particles / the content of the (meth) acrylic resin) was 0.94.

(Example 6)

An antireflection film was obtained in the same manner as in Example 1 except that the composition for a low refractive index layer (5) was used in place of the composition for a low refractive index layer (1).

In the low refractive index layer of the obtained antireflection film, the compounding ratio of the hollow fine silica particles to the (meth) acrylic resin (content of the hollow fine silica particles / content of the (meth) acrylic resin) was 1.60.

(Example 7)

On one side of a cellulose triacetate film (thickness 80㎛), the hard coat layer composition (3) The wet weight of 30g / m ² (dry weight 15g / m ²⁾ coated to form a hard coat layer, and continuously, to form a hard An antireflection film was obtained in the same manner as in Example 1 except that the composition for a low refractive index layer (2) was used on the coat layer to form a low refractive index layer.

(Example 8)

An antireflection film was obtained in the same manner as in Example 1 except that the composition for a low refractive index layer (6) was used in place of the composition for a low refractive index layer (1).

In the low refractive index layer of the obtained antireflection film, the compounding ratio of the hollow fine silica particles to the (meth) acrylic resin (content of the hollow fine silica particles / content of the (meth) acrylic resin) was 1.60.

(Comparative Example 1)

Except that the composition for a low refractive index layer (11) was used in place of the composition for a low refractive index layer (1) and the low refractive index layer was formed using the composition for a low refractive index layer (11) An antireflection film was obtained in the same manner as in Example 1.

(Comparative Example 2)

Except that the composition for a low refractive index layer (12) having the same composition as the composition for a low refractive index layer (12) was prepared except that the composition for a low refractive index layer (12) was used, 1, an antireflection film was obtained.

(Comparative Example 3)

A composition (13) for a low refractive index layer in which fine silica particles having no reactive functional group on the surface thereof (MEK-ST, manufactured by Nissan Chemical Industries, Ltd.) were prepared in the composition for a low refractive index layer (1) An antireflection film was obtained in the same manner as in Example 1 except that the layer composition (13) was used.

(Reference Example 1)

An antireflection film was obtained in the same manner as in Example 1 except that the composition for a low refractive index layer (7) was used in place of the composition for a low refractive index layer (1). In the obtained low refractive index layer of the antireflection film, the compounding ratio of the hollow fine silica particles to the (meth) acrylic resin (the content of the hollow fine silica particles / the content of the (meth) acrylic resin) was 0.80.

(Reference Example 2)

An antireflection film was obtained in the same manner as in Example 1 except that the composition for a low refractive index layer (8) was used in place of the composition for a low refractive index layer (1).

In the low refractive index layer of the obtained antireflection film, the compounding ratio of the hollow fine silica particles to the (meth) acrylic resin (content of the hollow fine silica particles / content of the (meth) acrylic resin) was 1.60. The content of the reactive silica fine particles in the low refractive index layer was 75 parts by mass based on 100 parts by mass of the (meth) acrylic resin.

(Reference Example 3)

An antireflection film was obtained in the same manner as in Example 1 except that the composition for a low refractive index layer (9) was used in place of the composition for a low refractive index layer (1).

In the low refractive index layer of the obtained antireflection film, the compounding ratio of the hollow fine silica particles to the (meth) acrylic resin (content of the hollow fine silica particles / content of the (meth) acrylic resin) was 1.60. The content of the reactive silica fine particles in the low refractive index layer was 65 parts by mass based on 100 parts by mass of the (meth) acrylic resin.

(Reference Example 4)

An antireflection film was obtained in the same manner as in Example 1 except that the composition for a low refractive index layer (10) was used in place of the composition for a low refractive index layer (1).

In the low refractive index layer of the obtained antireflection film, the compounding ratio of the hollow fine silica particles to the (meth) acrylic resin (content of the hollow fine silica particles / content of the (meth) acrylic resin) was 1.60. The content of the reactive silica fine particles in the low refractive index layer was 3 parts by mass based on 100 parts by mass of the (meth) acrylic resin.

(evaluation)

The anti-reflection films obtained in Examples and Comparative Examples were subjected to the following evaluations. The results are shown in Table 1.

(Measurement of reflectance)

A black tape for preventing the reflection of the back surface of each of the obtained antireflection films was attached and the surface of the low refractive index layer was irradiated with a 5 ° specular reflection at 380 to 780 nm in a wavelength region of 380 to 780 nm using a spectroscopic reflectance meter "MCP3100 " manufactured by Shimadzu Corporation. Y values were measured. The results were evaluated according to the following criteria. The 5 ° specular reflection Y value is a value represented by the luminous reflectance calculated by measuring the 5 ° specular reflectance in a wavelength range from 380 to 780 nm and then calculating the brightness (viscous feel) (converted into MCP 3100).

Evaluation standard

○: 5 ° Regular reflection Y value less than 1.5%

×: 5 ° Regular reflection Y value is 1.5% or more

(Scratch resistance)

The surface of the low refractive index layer of the antireflection film obtained in the Examples and Comparative Examples was rubbed 10 times with a predetermined friction load of 300 g / cm ² using a # 0000 steel wool, and the presence or absence of peeling of the coating film thereafter was visually observed The results were evaluated according to the following criteria.

◎: No scratches

○: slight scratches

X: With scratches

(Antifouling property)

After the fingerprints were attached to the surfaces of the antireflection films obtained in Examples and Comparative Examples, Kimwipe (registered trademark) manufactured by Nippon Seisakusha Co., Ltd. was wiped off 30 times at a load of 150 g / cm &lt; ² &gt; Remaining state) was evaluated with the naked eye under the fluorescent lamp by attaching a black tape to the following criteria.

◎: No fingerprint left

○: Some fingerprints remain

X: Fingerprint remains

(Cross-section observation of the low refractive index layer)

The antireflection films obtained in the Examples and Comparative Examples were cut in the thickness direction, and their cross sections were observed by STEM (applied voltage: 30.0 kV, magnification: 200,000 times). Results of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 are shown in Fig. 1, Fig. 2, 3 and 4, respectively. In addition, the anti-reflection film obtained in Comparative Example 1 formed a vapor deposition layer containing carbon having a thickness of about 150 nm at the time of cross section observation. 1 to 4, a scale with a scale of 20 nm is shown at the lower right.

1 and 2, the anti-reflection film according to Example 1 was found to have reactive silica fine particles unevenly distributed in the vicinity of the interface on the side opposite to the hard coat layer of the low refractive index layer, and the anti- , The reactive silica fine particles distributed in the vicinity of the interface near the hard coat layer side of the low refractive index layer and the interface near the opposite side of the hard coat layer were found and all hollow silica fine particles were densely packed, The surface was very uniform.

Further, although not shown in the figure, the anti-reflection film according to Example 3 was found to have reactive silica fine particles distributed in the vicinity of the interface of the hard coat layer side of the low refractive index layer, and the hollow fine silica particles were also densely packed, The surface of the refractive index layer was in a very uniform state. Although not shown, the anti-reflection films according to Examples 2, 4 to 6, and 8 were all found to have reactive silica fine particles unevenly distributed in the vicinity of the interface on the side opposite to the hard coat layer of the low refractive index layer, The surface of the low refractive index layer was in a highly uniform state.

Furthermore, from Table 1, all of the antireflection films according to the examples had sufficient antifouling properties, antireflection properties, and scratch resistance.

From the results of the examples, it was found that the scratch resistance was the best in the following cases.

The reactive silica fine particles are localized on the side opposite to the hard coat layer of the low refractive index layer, and the amount of localized reactive silica fine particles is optimum (30 parts by mass or more based on 100 parts by mass of the (meth) acrylic resin).

When the hardness of the entire underlying layer (light-transmitting substrate and hard coat layer) of the low refractive index layer is high due to the presence of the reactive silica fine particles in the hard coat layer.

The antifouling property was found to be the best when the reactive silica fine particles were localized on the hard coat layer side of the low refractive index layer. This is presumably because the antifouling agent itself tends to come out to the surface of the low refractive index layer as much as there is no reactive silica fine particles on the outermost surface of the low refractive index layer and the antifouling agent exists on the entire outermost surface of the low refractive index layer.

On the other hand, as shown in Fig. 3, in the antireflection film of Comparative Example 1, the reactive silica fine particles are uniformly present in the low refractive index layer, and the hard coat layer side of the low refractive index layer, Reactive silica fine particles which were localized in the vicinity of the interface were not recognized and their surfaces were not uniform. This is presumably due to the fact that the drying speed was fast due to the inadequate solvent and drying conditions. In addition, the antireflection film of Comparative Example 1 also had a reduced antifouling property. Further, as shown in Fig. 4, the antireflection film of Comparative Example 2 had a uniform surface with the hollow silica fine particles being densely packed. However, since the low refractive index layer does not contain the reactive silica fine particles, It was disappointing. Although not shown in the figure, the antireflection film of Comparative Example 3 contained fine silica particles in a state in which hollow silica fine particles were densely packed and had a uniform surface, but contained silica fine particles having no reactive functional group in the low refractive index layer The scratch resistance was low.

Further, the antireflection film of Reference Example 1 had a low ratio of the hollow fine silica particles to the (meth) acrylic resin of the low refractive index layer, and the antireflection performance deteriorated. The antireflection films according to Reference Examples 2 and 3 had a large content of reactive silica fine particles in the low refractive index layer, and the localization of the reactive silica fine particles was insufficient and existed uniformly in the low refractive index layer, and the hollow fine silica particles were densely It was not in a charged state, and scratch resistance and antifouling property were deteriorated. In addition, the antireflection film of Reference Example 4 has a low content of reactive silica fine particles in the low refractive index layer, an uneven distribution of the reactive silica fine particles is insufficient and exists uniformly in the low refractive index layer, and the hollow silica fine particles are also densely packed State, and the abrasion resistance and antifouling property were deteriorated.

&Lt; Industrial Availability >

The antireflection film of the present invention is excellent in antireflection performance and surface hardness because it has a low refractive index layer including the above-described constitution. Therefore, the antireflection film of the present invention can be applied to various fields such as a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), a field emission display (FED) , A tablet PC, an electronic paper, and the like.

Claims (11)

An antireflection film having a hard coat layer formed on a light transmitting substrate and a low refractive index layer formed on the hard coat layer,
Wherein the low refractive index layer contains (meth) acrylic resin, hollow silica fine particles, reactive silica fine particles and antifouling agent, and
The reactive silica fine particles in the low refractive index layer are localized in the vicinity of the interface near the hard coat layer and / or near the interface near the hard coat layer,
Wherein the hollow silica fine particles are contained in a state of a densely packed structure laminated in two stages in the thickness direction of the low refractive index layer while being densely packed in the low refractive index layer
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