JP2016061794A - Antireflection film, polarizing plate, cover glass, image display device, and production method of antireflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antireflection film having a moth-eye structure having a low reflectance, no cloudiness and excellent scratch resistance, and a production method of an antireflection film by which an antireflection film can be produced in an easy process, and to provide a polarizing plate, a cover glass and an image display device including the antireflection film.SOLUTION: The antireflection film includes, in the following order, a plastic substrate, a permeation layer, and an antireflection layer that comprises metal oxide fine particles having an average primary particle diameter of 50 nm or more and 250 nm or less and a thickening compound. The permeation layer comprises a polymerized product of a (meth)acrylate compound having a molecular weight of 400 or less. The antireflection layer has a moth-eye structure having a rugged pattern formed by the metal oxide fine particles.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an antireflection film, a polarizing plate, a cover glass, an image display device, and a method for producing an antireflection film.

  In image display devices such as cathode ray tube display (CRT), plasma display (PDP), electroluminescence display (ELD), fluorescent display (VFD), field emission display (FED), and liquid crystal display (LCD), An antireflection film may be provided in order to prevent a decrease in contrast and reflection of an image due to reflection of external light on the display surface.

  As an antireflection film, an antireflection film having a fine uneven shape with a period equal to or less than the wavelength of visible light on the surface of the substrate, that is, an antireflection film having a so-called moth eye structure is known. With the moth-eye structure, it is possible to create a refractive index gradient layer in which the refractive index continuously changes from air to the bulk material inside the substrate, thereby preventing light reflection.

  As an antireflection film having a moth-eye structure, Patent Document 1 discloses that a coating liquid containing a transparent resin monomer and fine particles is applied on a transparent substrate and cured to form a transparent resin in which the fine particles are dispersed. An anti-reflection film having a moth-eye structure manufactured by etching a resin is described.

  Patent Document 2 describes an antireflection film having a moth-eye structure obtained by polymerizing a (meth) acrylic polymerizable composition containing urethane (meth) acrylate and ester (meth) acrylate.

JP 2009-139796 A JP 2011-002759 A

  However, in the techniques of Patent Documents 1 and 2, it is necessary to perform shaping by etching or transfer using a mold on the transparent resin, and the manufacturing process of the antireflection film may be complicated. Further, in the technique of Patent Document 2, since a hard material cannot be used, the scratch resistance may be insufficient.

Therefore, the present inventor has examined the production of a moth-eye structure without performing shaping by etching or transfer using a mold.
On the base material, a composition (coating liquid) containing particles and a binder resin or a binder resin forming compound was applied and a film having a moth-eye structure was simply formed by curing.
(1) If the content of the particles is high and the content of the binder resin or binder resin-forming compound is low at the stage before coating, the particles aggregate from the coating solution to the film. , Uneven structure (moth eye structure) with a uniform surface is not possible. As a result, the antireflection function is deteriorated. Furthermore, if the particles are aggregated too much, the aggregated part acts as a large scatterer, so that the film becomes cloudy and haze is generated. As a result, the contrast is deteriorated, and the beautiful blackening of the screen by the antireflection film is also lost.
(2) When the content of the particles is low and the content of the binder resin or the binder resin forming compound is high at the stage after coating, the particles are buried in the binder resin or the binder resin forming compound, resulting in a concavo-convex structure. It has been found that there is a problem that it cannot be formed and sufficient antireflection performance cannot be obtained.

  That is, an object of the present invention is to provide an antireflection film having a moth-eye structure with low reflectance, no cloudiness, and excellent scratch resistance, and a method for producing an antireflection film that can be produced by a simple method. is there. Another object of the present invention is to provide a polarizing plate, a cover glass, and an image display device including an antireflection film.

As a result of intensive studies by the present inventors, the coating solution for forming the antireflection layer contains a low molecular weight monomer that easily permeates the base material or the lower layer and a compound that tends to hinder the cohesive force of the particles (thickening compound). The particles can be prevented from agglomerating with each other, and the particles protrude due to the infiltration of the monomer, so that when the film is completed, the height of the protrusions and the protrusions in the uneven structure formed by the particles It was found that the interval between them can be adjusted optimally. As a result, it was found that a moth-eye structure having low reflection, excellent surface uniformity, and excellent scratch resistance can be easily produced.
When the soaking of the monomer occurs, the apparent particle content in the coating film increases, so if there is no thickening compound, the particles will aggregate between the application of the coating solution and the film formation. . The thickening effect of the thickening compound hinders the cohesive force of the particles, and even if the apparent content of particles in the coating film increases, the particles protrude without being aggregated, and a desired uneven structure can be obtained.
This effect cannot be obtained simply by increasing the solid content concentration of the coating solution and increasing the viscosity of the coating solution. This is because the solvent is volatilized by drying after the coating solution is applied, but the monomer infiltrates into the substrate or the lower layer thereafter, and the apparent particle content in the coating film increases, so the coating solution solids. It can be presumed that the increase in the partial concentration cannot prevent the cohesive force of the particles in this process.

  That is, the said subject is solved by the following structures.

[1]
An antireflection film having a plastic substrate, a permeation layer, an antireflection layer containing metal oxide fine particles having an average primary particle size of 50 nm to 250 nm and a thickening compound in this order,
The penetration layer includes a polymer of a (meth) acrylate compound having a molecular weight of 400 or less,
The antireflection layer is an antireflection film having a moth-eye structure having an uneven shape formed by the metal oxide fine particles.
[2]
The antireflection film according to [1], wherein the antireflection layer further contains a binder resin.
[3]
The antireflection film as described in [1], wherein the thickening compound contained in the antireflection layer also serves as a binder resin.
[4]
The antireflection film according to any one of [1] to [3], wherein the permeation layer further contains the thickening compound.
[5]
The antireflection film according to [4], wherein the concentration of the thickening compound in the permeation layer is lower than the concentration of the thickening compound in the antireflection layer.
[6]
The concave / convex shape of the antireflection layer is such that B / A, which is a ratio of the distance A between the apexes of adjacent convex portions and the distance B between the centers of the adjacent convex portions and the concave portions, is 0.6 or more. The antireflection film according to any one of [1] to [5].
[7]
The antireflection film according to any one of [1] to [6], wherein the metal oxide fine particles contain only metal oxide fine particles having an average primary particle size of 50 nm to 250 nm.
[8]
The anti-reflection film according to any one of [1] to [7], wherein the thickening compound is a urethane compound.
[9]
The said urethane compound is an antireflection film as described in [8] which is a tetrafunctional or more urethane (meth) acrylate.
[10]
The said thickening compound is an antireflection film of any one of [1]-[9] whose viscosity in 100 degreeC is 15-100000 mPa * s.
[11]
The plastic substrate according to any one of [1] to [10], wherein the plastic substrate is a substrate containing cellulose acylate.
[12]
The antireflection film according to any one of [1] to [11], wherein the metal oxide fine particles are silica particles.
[13]
The antireflection film according to any one of [1] to [12], wherein the indentation hardness of the metal oxide fine particles is 400 MPa or more.
[14]
The antireflection film according to any one of [1] to [13], wherein the metal oxide fine particles are fired silica particles whose surface is modified with a compound having a (meth) acryloyl group.
[15]
The antireflection film according to any one of [6] to [14], wherein the half width of the distribution of the distance A is 200 nm or less.
[16]
A polarizing plate having the antireflection film according to any one of [1] to [15] as a protective film for a polarizing plate.
[17]
A cover glass having the antireflection film according to any one of [1] to [15] as a protective film.
[18]
An image display device comprising the antireflection film according to any one of [1] to [15] or the polarizing plate according to [16].
[19]
A plastic substrate, a permeation layer, and an antireflection layer containing metal oxide fine particles having an average primary particle size of 50 nm or more and 250 nm or less and a thickening compound in this order, and the antireflection layer includes the plastic substrate. A method for producing an antireflection film having a moth-eye structure having a concavo-convex shape formed by the metal oxide fine particles on the surface opposite to the side interface,
A functional layer provided on a plastic substrate or a plastic substrate, a thickening compound, a (meth) acrylate compound having a molecular weight of 400 or less, metal oxide fine particles having an average primary particle size of 50 nm or more and 250 nm or less, A composition for forming an antireflection layer containing a solvent is applied, the (meth) acrylate compound is allowed to permeate into the plastic substrate or a functional layer provided on the plastic substrate, and the metal oxide fine particles are introduced into the functional layer. Projecting from the surface opposite to the plastic substrate side interface;
Polymerizing the (meth) acrylate compound to form a permeation layer containing a polymer of the (meth) acrylate compound, and an antireflection layer having a moth-eye structure formed by the metal oxide fine particles;
The manufacturing method of the antireflection film which has this.
[20]
The composition for forming an antireflective layer is the method for producing an antireflective film according to [19], wherein the viscosity at 100 ° C. is 15 to 100 mPa · s.

  According to the present invention, it is possible to provide an antireflection film having a moth-eye structure having a low reflectance, no cloudiness, and excellent scratch resistance, and a method for producing an antireflection film that can be produced by a simple method. Moreover, according to this invention, the polarizing plate, the cover glass, and image display apparatus containing the said antireflection film can be provided.

It is a schematic diagram which shows an example of the antireflection film of this invention.

  The antireflection film of the present invention has an antireflection film comprising a plastic substrate, a permeation layer, metal oxide fine particles having an average primary particle diameter of 50 nm to 250 nm, and an antireflection layer containing a thickening compound in this order. The penetration layer includes a polymer of a (meth) acrylate compound having a molecular weight of 400 or less, and the antireflection layer has a moth-eye structure having an uneven shape formed by the metal oxide fine particles. It is a prevention film.

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

An example of a preferred embodiment of the antireflection film of the present invention is shown in FIG.
An antireflection film 10 in FIG. 1 includes a plastic substrate 1, a permeation layer 5, and an antireflection layer 2. The antireflection layer 2 has a moth-eye structure having a concavo-convex shape formed by the metal oxide fine particles 3 on the surface opposite to the interface on the penetrating layer 5 side.
The antireflection layer 2 contains metal oxide fine particles 3 and a thickening compound, and the thickening compound is preferably contained in the binder resin 4. As will be described later, the thickening compound may also serve as the binder resin.

(Moth eye structure)
The surface of the antireflection layer on the side opposite to the interface on the substrate side has a moth-eye structure having a concavo-convex shape formed by metal oxide fine particles.
Here, the moth-eye structure refers to a processed surface of a substance (material) for suppressing light reflection, and a structure having a periodic fine structure pattern. In particular, for the purpose of suppressing the reflection of visible light, it refers to a structure having a fine structure pattern with a period of less than 780 nm. It is preferable that the period of the fine structure pattern is less than 380 nm because the color of the reflected light is eliminated. A period of 100 nm or more is preferable because light with a wavelength of 380 nm can recognize a fine structure pattern and is excellent in antireflection properties. The presence or absence of the moth-eye structure can be confirmed by observing the surface shape with a scanning electron microscope (SEM), an atomic force microscope (AFM), or the like, and examining whether the fine structure pattern is formed.

The concavo-convex shape of the antireflection layer of the antireflection film of the present invention is such that the distance A between the vertices of the adjacent convex portions and the distance between the vertices of the adjacent convex portions and the concave portion (the depth of the concave portion or the convex portion). It is preferable that B / A, which is a ratio to (height) B, is 0.6 or more. When B / A is 0.6 or more, the depth of the concave portion increases with respect to the distance between the convex portions, and a refractive index gradient layer in which the refractive index changes more gradually from the air to the inside of the antireflection layer is formed. Therefore, the reflectance can be further reduced.
B / A can be controlled by including an appropriate amount of metal oxide fine particles, a thickening compound, and a (meth) acrylate compound having a molecular weight of 400 or less in the composition for forming an antireflection layer. Therefore, it is preferable to appropriately design the blending ratio of the thickening compound, the metal oxide fine particles, and the (meth) acrylate compound having a molecular weight of 400 or less. Further, the thickening compound and the (meth) acrylate compound having a molecular weight of 400 or less permeate into the base material or the lower layer or volatilize in the step of producing the moth-eye structure, Since the volume ratio of the metal oxide fine particles may be different from the blending ratio in the composition for forming an antireflection layer, it is preferable to appropriately set matching with the substrate.
Furthermore, in order to make B / A 0.6 or more and to reduce the reflectance, it is preferable that the metal oxide fine particles forming the convex portions are uniformly spread at a high filling rate, but the filling rate is It is also preferred that it is not too high. This is because if the filling rate is too high, adjacent particles come into contact with each other to reduce the B / A of the concavo-convex structure. From the above viewpoint, it is preferable that the content of the metal oxide fine particles forming the convex portion is adjusted so as to be uniform throughout the antireflection layer. The filling rate can be measured as the area occupancy of the particles located on the most surface side when observing the metal oxide fine particles forming convex portions from the surface by SEM or the like, preferably 30% to 95%, 40 -90% is more preferable, and 50-85% is still more preferable.

A method for measuring B / A, which is a ratio of the distance A between the apexes of adjacent convex portions and the distance B between the center between the apexes of adjacent convex portions and the concave portion, will be described in more detail below.
B / A can be measured by cross-sectional SEM observation of the antireflection film. The antireflection film sample is cut with a microtome to obtain a cross section, and SEM observation is performed at an appropriate magnification (about 5000 times). For easy observation, the sample may be subjected to appropriate processing such as carbon deposition and etching. B / A is the distance between the vertices of adjacent protrusions at the interface between the air and the sample, and the vertices of adjacent protrusions in the plane perpendicular to the substrate surface including the vertices of the adjacent protrusions. The distance between the straight line connecting the two and the vertical bisector reaching the particle or the binder resin is defined as B, and when 100 points are measured, the average value of B / A is calculated.
In the SEM photograph, there are cases where the distance A between the vertices of the adjacent convex portions and the distance B between the vertices of the adjacent convex portions and the concave portion B cannot be measured accurately with respect to all the projected and recessed portions. However, in that case, the length may be measured by paying attention to the convex portion and the concave portion shown on the near side in the SEM image.
Note that the concave portion needs to be measured at the same depth as the particles forming the two adjacent convex portions to be measured in the SEM image. This is because if the distance to a particle or the like reflected on the near side is measured as B, B may be estimated small.

  B / A is preferably 0.6 or more, more preferably 0.7 or more, and still more preferably 0.8 or more. Moreover, from the viewpoint that the moth-eye structure can be firmly fixed and has excellent scratch resistance, it is preferably 0.9 or less.

[Plastic substrate]
The plastic substrate in the antireflection film of the present invention will be described.
The plastic substrate can be variously used, for example, cellulose resin; cellulose acylate (triacetate cellulose, diacetyl cellulose, acetate butyrate cellulose), polyester resin; polyethylene terephthalate, (meth) acrylic resin, Examples include base materials containing polyurethane-based resins, polycarbonates, polystyrenes, olefin-based resins, etc. From the viewpoint of easy production of a permeation layer, base materials containing cellulose acylate, polyethylene terephthalate, or (meth) acrylic resins. Preferably, a substrate containing cellulose acylate or (meth) acrylic resin is more preferable, and a substrate containing cellulose acylate is still more preferable. As the cellulose acylate, a substrate described in JP 2012-093723 A or the like can be preferably used.

Moreover, as a plastic base material containing (meth) acrylic-type resin, the thermoplastic resin which consists of (meth) acrylic-type resin which has a (meth) acrylic-type polymer as a main component can be used. However, having a (meth) acrylic polymer as a main component means that the base material contains 50% by mass or more of a (meth) acrylic polymer.
The (meth) acrylic polymer is a concept including both a methacrylic polymer and an acrylic polymer. The (meth) acrylic polymer also includes acrylate / methacrylate derivatives, in particular, acrylate ester / methacrylate ester (co) polymers. More specifically, a base material described in JP-A No. 2014-95731 can be used.

  The thickness of the plastic substrate is usually about 10 μm to 1000 μm, but is preferably 20 μm to 200 μm, more preferably 25 μm to 100 μm from the viewpoint of good handleability, high transparency, and sufficient strength. preferable. As the transparency of the plastic substrate, those having a transmittance of 90% or more are preferable.

  The plastic substrate may be provided with another functional layer on the surface when the permeation layer can be formed when the antireflection layer is laminated. For example, it may be provided with a hard coat layer for imparting hard coat properties to the substrate, an easy adhesion layer for imparting adhesion to other layers, a layer for imparting antistatic properties, etc. A plurality of them may be provided.

[Penetration layer]
The antireflection film of the present invention has a permeation layer between the plastic substrate and the antireflection layer.
In the present invention, the osmotic layer is a layer (region) containing a component contained in a plastic substrate component or a functional layer and a polymer of a (meth) acrylate compound having a molecular weight of 400 or less. A compound may be included. The permeation layer in the present invention is a plastic substrate or a functional layer provided on a plastic substrate, a thickening compound, a (meth) acrylate compound having a molecular weight of 400 or less, and an average primary particle size of 50 nm to 250 nm. In the functional layer provided on the plastic substrate or the plastic substrate, the composition for forming an antireflection layer containing the metal oxide fine particles and the solvent is applied, and the (meth) acrylate compound having a molecular weight of 400 or less is applied. Obtained by infiltration. At this time, the thickening compound may penetrate into the plastic substrate.
In addition, the thickening compound refers to a compound in which the viscosity of the solid content is increased by containing it.
In the present invention, hereinafter, the plastic substrate refers to a portion that contains a plastic substrate component and does not contain a thickening compound and a polymer of a (meth) acrylate compound having a molecular weight of 400 or less. The antireflection layer includes a metal oxide fine particle and a thickening compound and refers to a portion different from the permeation layer.
In addition, the permeation layer is obtained by cutting the antireflection film of the present invention with a microtome and analyzing the cross section with a time-of-flight secondary ion mass spectrometer (TOF-SIMS), and the plastic substrate component and the molecular weight are 400 or less. It can be measured as a portion where the polymer of the (meth) acrylate compound is detected together, and the film thickness in this region can also be measured from the cross-sectional information of TOF-SIMS.
In addition, the permeation layer can also be detected by detecting another layer between the base material and the antireflection layer, for example, by cross-sectional observation using a reflection spectral film thickness meter or TEM (transmission electron microscope) using light interference. It can be measured. As the reflective spectral film thickness meter, FE-3000 (manufactured by Otsuka Electronics Co., Ltd.) or the like can be used.
The thickness of the permeation layer is preferably 0.1 μm or more and 5 μm or less from the viewpoint of forming a moth-eye layer without increasing the particle content in the coating composition.
From the viewpoint that the osmotic layer can be efficiently formed, the osmotic layer preferably contains a base material permeable solvent, and more preferably contains a solvent that is permeable to the base material and does not swell the base material. preferable. 10-95 mass% is preferable and, as for content of the base-material penetrating solvent in the composition for antireflection layer formation, 20-90 mass% is more preferable.

((Meth) acrylate compound having a molecular weight of 400 or less)
The permeation layer of the antireflection film of the present invention contains a polymer obtained by polymerizing a (meth) acrylate compound having a molecular weight of 400 or less.
The (meth) acrylate compound having a molecular weight of 400 or less has a low particle content in the stage before coating, and does not aggregate the particles with a high content of binder resin or binder resin forming compound. Has a function of penetrating the base material to form a permeation layer and projecting the particles. The (meth) acrylate compound having a molecular weight of 400 or less can be used without limitation as long as it is a polymerizable compound having a molecular weight of 400 or less and having a (meth) acryloyl group, but the film strength after polymerization and curing can be increased. Therefore, it is preferable to have two or more (meth) acryloyl groups in one molecule. Furthermore, since the penetration layer is formed by polymerization and curing after penetrating into the base material, it is preferable that the compatibility with the material constituting the base material is good from the viewpoint of transmittance and light scattering.
Specific examples of (meth) acrylate having a molecular weight of 400 or less include 2-hydroxyethyl methacrylate (HEMA), 1,4-butanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trimethylolpropane triacrylate, Glycidyl (meth) acrylate, alkylene oxide-modified acrylate and the like can be preferably used. In addition, among the products on the market, Biscote # 195, Biscote # 295 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), Blemmer G, Blemmer GMR, Blemmer PDE-200 (manufactured by NOF Corporation), KAYARAD PET30 (Nippon Kayaku) NK ester A-TMPT (manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like can be used.
The molecular weight of the (meth) acrylate compound having a molecular weight of 400 or less is preferably 150 to 400, more preferably 200 to 350. By being more than a lower limit, it can volatilize in a manufacturing process and can suppress the contamination of the process in a manufacturing machine, and by being below an upper limit, it becomes easy to osmose | permeate a base material or a functional layer.

[Antireflection layer]
The antireflection layer includes metal oxide fine particles having an average primary particle diameter of 50 nm or more and 250 nm or less and a thickening compound.
A moth-eye structure is formed by the metal oxide fine particles on the surface of the antireflection layer opposite to the interface on the permeation layer side. The antireflection layer in the present invention is prepared by, for example, applying the antireflection layer forming composition on a plastic substrate in the production method described later, and applying a (meth) acrylate compound having a molecular weight of 400 or less in the plastic substrate. When the permeation layer is formed by permeation, it is formed on the permeation layer. The antireflection layer may further contain a binder resin, or a thickening compound may also serve as the binder resin.

  The thickness of the antireflection layer is preferably 0.05 to 5 μm, and more preferably 0.1 to 1 μm.

(Metal oxide fine particles)
The metal oxide fine particles forming the moth-eye structure of the antireflection layer will be described.
The metal oxide fine particles have an average primary particle size of 50 nm or more and 250 nm or less.

As the metal oxide fine particles, metal oxide fine particles having an average primary particle diameter of 50 nm or more and 250 nm or less and a dispersion degree Cv value of the average primary particle diameter of 10% or less can be suitably used. The degree of dispersion Cv is
Cv value = ([standard deviation of average primary particle size] / [average particle size]) × 100 (1)
Is a value (unit:%) that can be obtained by calculation, and the smaller the value, the greater the average primary particle size. The average primary particle size is measured using a scanning electron microscope (SEM). The average particle diameter of the metal oxide fine particles and the standard deviation thereof are calculated based on the measured values of the particle diameters of 200 or more metal oxide fine particles. In addition, the average particle diameter here means the maximum diameter of a circumscribed circle when the particles are not spherical. Also in the case of a mixture of a plurality of types of particles having different average primary particle sizes, the Cv value as a whole particle is calculated.
When the average primary particle size is 50 nm or more, it can function as an antireflection layer having a moth-eye structure, and when it is 250 nm or less, Bragg diffraction due to regular arrangement of metal oxide fine particles hardly occurs in the visible light region. The color development (coloring) phenomenon derived from this is not shown. Therefore, it is preferable that the Cv value is small because particle aggregation is less likely to occur and an antireflection layer having a low reflectance and a high transmittance can be formed without coloring. The average primary particle size is preferably from 100 nm to 220 nm, and more preferably from 120 nm to 200 nm. The Cv value is preferably 1 to 10%, more preferably 1 to 5%.
From the reason that the Cv value can be reduced, it is preferable that the metal oxide fine particles contain only metal oxide fine particles having a primary particle size of 50 nm to 250 nm, and only metal oxide fine particles having a primary particle size of 100 nm to 220 nm. It is more preferable to contain only metal oxide fine particles having a primary particle size of 120 nm to 200 nm.
The average primary particle size of the metal oxide fine particles refers to a cumulative 50% particle size of the volume average particle size. When measuring the average primary particle size of the metal oxide fine particles contained in the antireflection layer, it can be measured by an electron micrograph. For example, the antireflection film is observed from the surface side by SEM observation at an appropriate magnification (about 5000 times), the diameter of each of the 100 primary particles is measured, the volume is calculated, and the cumulative 50% particle size is calculated. The average primary particle size can be obtained. When the particles are not spherical, the average value of the major and minor diameters is regarded as the diameter of the primary particles. At this time, for easy observation, the sample may be appropriately subjected to carbon deposition, etching, or the like.

In the present invention, the indentation hardness of the metal oxide fine particles is preferably 400 MPa or more, more preferably 450 MPa or more, and most preferably 550 MPa or more. It is preferable that the indentation hardness of the metal oxide fine particles is 400 MPa or more because durability against pressure in the thickness direction of the moth-eye structure is increased. Further, the indentation hardness of the metal oxide fine particles is preferably 1000 MPa or less so as not to be brittle and easy to break.
The indentation hardness of the metal oxide fine particles can be measured with a nanoindenter or the like. As a specific measuring method, the sample can be measured by arranging metal oxide fine particles on a substrate (glass plate, quartz plate, etc.) harder than itself so as not to overlap one or more stages and pushing with a diamond indenter. At this time, it is preferable to fix with a resin or the like so that the particles do not move. However, when fixing with resin, it adjusts so that a part of particle | grain may be exposed. Moreover, it is preferable to specify a pushing position with a tribo indenter.
Also in the present invention, particles are arranged on a substrate, a sample in which particles are bound and fixed using a small amount of curable resin so as not to affect the measurement value, and the sample is measured by an indenter. Was used to determine the indentation hardness of the metal oxide fine particles.

  Examples of the metal oxide fine particles include silica particles, titania particles, zirconia particles, and antimony pentoxide particles. From the viewpoint that moth-eye structures are easily formed because haze is not easily generated because the refractive index is close to that of many binders. Silica particles are preferred.

The metal oxide fine particles are particularly preferably calcined silica particles because the surface hydroxyl group amount is moderately large and the particles are hard particles.
The calcined silica particles are manufactured by a known technique in which silica particles are obtained by hydrolyzing and condensing a hydrolyzable silicon compound in an organic solvent containing water and a catalyst, and then the silica particles are calcined. For example, JP2003-176121A, JP2008-137854A, and the like can be referred to.
Although it does not specifically limit as a raw material silicon compound which manufactures a burning silica particle, Chlorosilanes, such as tetrachlorosilane, methyltrichlorosilane, phenyltrichlorosilane, dimethyldichlorosilane, diphenyldichlorosilane, methylvinyldichlorosilane, trimethylchlorosilane, methyldiphenylchlorosilane Compounds: tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, trimethoxyvinylsilane, triethoxyvinylsilane, 3-glycidoxypropyltrimethoxysilane, 3-chloro Propyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3- (2-aminoethylamino) propyltrimethoxy Silane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-chloropropylmethyldimethoxysilane, Alkoxysilane compounds such as diphenyldimethoxysilane, diphenyldiethoxysilane, dimethoxydiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane; tetraacetoxysilane, methyltriacetoxysilane, phenyltriacetoxysilane, dimethyldiacetoxysilane, diphenyldiacetoxysilane Acyloxysilane compounds such as trimethylacetoxysilane; dimethylsilanediol, diphenylsilanediol, tri Silanol compounds such as chill silanol; and the like. Of the above-exemplified silane compounds, the alkoxysilane compound is particularly preferred because it is more easily available and the resulting fired silica particles do not contain halogen atoms as impurities. As a preferred form of the calcined silica particles according to the present invention, it is preferred that the halogen atom content is substantially 0% and no halogen atoms are detected.
Although a calcination temperature is not specifically limited, 800-1300 degreeC is preferable and 1000 degreeC-1200 degreeC is more preferable.

  The calcined silica particles are preferably calcined silica particles whose surface is modified with a compound having a (meth) acryloyl group. By using calcined silica particles whose surface is modified with a compound having a (meth) acryloyl group, effects such as improvement in dispersibility in the composition for forming an antireflection layer, improvement in film strength, and prevention of aggregation can be expected. . For specific examples of the surface treatment method and preferred examples thereof, reference can be made to the descriptions in [0119] to [0147] of JP-A-2007-298974.

  The shape of the metal oxide fine particles is most preferably spherical, but there is no problem even if the shape is not spherical such as indefinite.

  The metal oxide fine particles may be used by firing commercially available particles. As specific examples, IPA-ST-L (average primary particle size 50 nm, silica sol manufactured by Nissan Chemical Industries, Ltd.), IPA-ST-ZL (average primary particle size 80 nm, silica sol manufactured by Nissan Chemical Industries, Ltd.) , Snowtex MP-1040 (average primary particle size 100 nm, silica manufactured by Nissan Chemical Industries, Ltd.), Snowtex MP-2040 (average primary particle size 200 nm, silica manufactured by Nissan Chemical Industries, Ltd.), Seahoster KE-P10 ( Average primary particle size 150 nm, Nippon Shokubai Co., Ltd. amorphous silica), Seahoster KE-P20 (average primary particle size 200 nm, Nippon Shokubai Co., Ltd. amorphous silica), ASFP-20 (average primary particle size 200 nm, Nippon Electrochemical) (Alumina manufactured by Kogyo Co., Ltd.) and the like can be preferably used. Furthermore, as long as the requirements of the metal oxide fine particles of the present invention are satisfied, commercially available particles may be used as they are.

  The half-value width of the distribution of the distance A between the vertices of adjacent convex portions in the antireflection layer is preferably 200 nm or less. The half-value width of the distribution of A is 200 nm or less, which means that the distribution of the distance between particles is narrow (sharp), and the particles are uniformly present without coming close or extremely separated. It is preferable from the viewpoint of reduction and reflectance reduction. The half width of the A distribution is more preferably 125 nm or less, and further preferably 100 nm or less.

  The content of the metal oxide fine particles in the antireflection layer is preferably 50 to 95% by mass, and more preferably 60 to 90% by mass with respect to the total mass of the antireflection layer. When the content of the metal oxide fine particles is 50% by mass or more, although depending on the particle diameter, the surface tends to have a moth-eye structure. Further, when the content of the metal oxide fine particles is 95% by mass or less, the particles can be bound to the film.

(Thickening compound)
The antireflection layer of the present invention contains a thickening compound in order to suppress aggregation of the metal oxide fine particles. As used herein, the thickening compound means that the viscosity of the solid content increases when it is contained, and the viscosity is higher than that of the (meth) acrylate compound having a molecular weight of 400 or less. The thickening compound is not particularly limited as long as it is soluble in the composition for forming an antireflection layer. From the viewpoint of compatibility with metal oxide fine particles, a (meth) acrylate compound having a molecular weight of 400 or less, and the like. Appropriate ones can be selected. Examples of the thickening compound include organic polymer thickeners, inorganic oxide thickeners, and the like, which are highly effective in suppressing aggregation of particles, and include metal oxide fine particles and (meth) acrylate having a molecular weight of 400 or less. From the viewpoint of good compatibility, it is preferably a urethane compound, and from the viewpoint of excellent scratch resistance, it is more preferably a tetrafunctional or higher functional urethane (meth) acrylate. The thickening compound may also serve as a binder. In this case, an organic acrylic low molecular weight compound or the like can be preferably used as the thickening compound.
The viscosity of the thickening compound is preferably 15 to 100,000 mPa · s, more preferably 30 to 10,000 mPa · s at 100 ° C. It is because the aggregation suppression effect of particle | grains can be expressed in the heat-drying process by which a (meth) acrylate compound with a molecular weight of 400 or less is infiltrated into a base material by being in said range.

<Organic polymer thickener>
Examples of organic polymer thickeners include, but are not limited to:
Poly-ε-caprolactone, poly-ε-caprolactone diol, poly-ε-caprolactone triol, polyvinyl acetate, poly (ethylene adipate), poly (1,4-butylene adipate), poly (1,4-butylene glutarate), poly (1,4-butylene succinate), poly (1,4-butylene terephthalate), poly (ethylene terephthalate), poly (2-methyl-1,3-propylene adipate), poly (2-methyl-1,3-propylene) Glutarate), poly (neopentyl glycol adipate), poly (neopentyl glycol sebacate), poly (1,3-propylene adipate), poly (1,3-propylene glutarate), polyvinyl butyral, polyvinyl formal, polyvinyl acetal, poly Examples include livinylpropanal, polyvinylhexanal, polyvinylpyrrolidone, polyacrylic acid ester, polymethacrylic acid ester, cellulose acetate, cellulose propionate, cellulose acetate butyrate, polystyrene, and polyurethane.

  The molecular weight of the organic polymer thickener is preferably from 30,000 to 400,000 in terms of number average molecular weight, more preferably from 4,000 to 300,000, particularly preferably from 50,000 to 200,000.

  When the thickening compound is a polymer of a monomer having a polymerizable group, the calculated value of the molecular weight between crosslinks of the thickening compound is preferably 500 or more, more preferably 550 or more, and still more preferably 700 or more. The thickening effect increases as the molecular weight between crosslinks increases. The calculated value of the molecular weight between crosslinks is a polymer in which all the polymerizable groups of the monomer are polymerized, and (a) a total of 3 or more carbon atoms substituted with 3 or more carbon atoms and / or silicon atoms. An atomic group sandwiched between (a) and (a), (b) and (b), or (a) and (b), where (b) is a silicon atom substituted with an atom and / or an oxygen atom The total atomic weight of However, since a compound containing a fluorine atom and a silicon atom has a lower refractive index than a compound not containing these atoms, when used as a binder resin for an antireflection layer, the reflectance may be slightly impaired depending on the substrate. Therefore, a compound containing no fluorine atom or silicon atom is more preferable.

<Inorganic oxide thickener>
Examples of the inorganic oxide thickener include, but are not limited to, the following.
Known viscosity modifiers and thixotropic properties such as smectite, tetrasilica mica, bentonite, silica, montmorillonite and polyacrylic acid soda described in JP-A-8-325491, JP10-219136 ethylcellulose, polyacrylic acid, organic clay, etc. Agents can be used.

  The thickening compound may also serve as a binder resin. In this case, as the thickening compound, an organic acrylic low molecular weight compound can be preferably used, and a high viscosity compound is preferable. Moreover, since it is preferable that the refractive index changes gently also in regions other than the moth-eye structure, the thickening compound may penetrate into the substrate. When the thickening compound is present in the permeation layer, the thickening compound is preferably used more effectively for suppressing the aggregation of particles in the antireflection layer. The concentration is preferably lower than the concentration of the thickening compound in the layer.

  The content of the thickening compound in the antireflection layer is preferably from 1 to 50 mass%, more preferably from 5 to 40 mass%, based on the mass of the antireflection layer. When the content of the thickening compound is 1% by mass or more, the effect of suppressing the aggregation of particles is sufficiently obtained, and when the content of the thickening compound is 50% by mass or less, the surface has a moth-eye structure depending on the particle size. Cheap.

<Binder resin>
As described above, the antireflection layer may further contain a binder resin.
The binder resin is preferably formed by a crosslinking reaction or a polymerization reaction of a curable compound (preferably an ionizing radiation curable compound) that is a compound having a polymerizable group. As the curable compound, an ionizing radiation curable polyfunctional monomer or polyfunctional oligomer can be used.
The functional group of the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer is preferably a light, electron beam, or radiation polymerizable group, and among them, a photopolymerizable functional group is preferable.
Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group is preferable.

Specific examples of the compound having a polymerizable unsaturated group include (meth) acrylic acid diesters of alkylene glycol such as neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate, propylene glycol di (meth) acrylate;
(Meth) acrylic acid diesters of polyoxyalkylene glycols such as triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate;
(Meth) acrylic acid diesters of polyhydric alcohols such as pentaerythritol di (meth) acrylate;
(Meth) acrylic acid diesters of ethylene oxide or propylene oxide adducts such as 2,2-bis {4- (acryloxy · diethoxy) phenyl} propane and 2-bis {4- (acryloxy · polypropoxy) phenyl} propane And the like.

  Furthermore, epoxy (meth) acrylates, urethane (meth) acrylates, and polyester (meth) acrylates are also preferably used as the photopolymerizable polyfunctional monomer.

  Among these, esters of polyhydric alcohol and (meth) acrylic acid are preferable. More preferably, a polyfunctional monomer having 3 or more (meth) acryloyl groups in one molecule is preferable. For example, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, PO modified trimethylolpropane tri (meth) acrylate, EO Modified tri (meth) acrylate phosphate, trimethylolethane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa ( (Meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-chlorohexane tetramethacrylate, polyurethane polyacrylate Over DOO, polyester polyacrylate and caprolactone-modified tris (acryloyloxyethyl) isocyanurate.

  Specific compounds of polyfunctional acrylate compounds having a (meth) acryloyl group include KAYARAD DPHA, DPHA-2C, PET-30, TMPTA, TPA-320, TPA-330, RP-1040, T-1420, D-310, DPCA-20, DPCA-30, DPCA-60, GPO-303 (manufactured by Nippon Kayaku Co., Ltd.), NK ester A-TMPT, A-TMMT, A -TMM3, A-TMM3L, A-9550 (manufactured by Shin-Nakamura Chemical Co., Ltd.), V # 3PA, V # 400, V # 36095D, V # 1000, V # 1080, Biscote # 802 (Osaka Organic Chemical ( Co., Ltd.) and the esterified product of (meth) acrylic acid, SIRIUS-501, SUBARU-501 (Osaka Organic Chemical Industry) Dendrimers polyfunctional acrylate Ltd.)), and the like. Also, purple light UV-1400B, UV-1700B, UV-6300B, UV-7550B, UV-7600B, UV-7605B, UV-7610B, UV-7620EA, UV-7630B, UV-7630B, UV-7640B. UV-6630B, UV-7000B, UV-7510B, UV-7461TE, UV-3000B, UV-3200B, UV-3210EA, UV-3210EA, UV-3310EA, UV-3310B, UV-3500BA , UV-3520TL, UV-3700B, UV-6100B, UV-6640B, UV-2000B, UV-2010B, UV-2250EA, UV-2750B (manufactured by Nippon Synthetic Chemical Co., Ltd.), UL-503LN (manufactured by Kyoeisha Chemical Co., Ltd.), Unidic 17-80 17-813, V-4030, V-4000BA (Dainippon Ink Chemical Co., Ltd.), EB-1290K, EB-220, EB-5129, EB-1830, EB-4858 (Daicel UCB ( Ltd.), High Corp AU-2010, AU-2020 (manufactured by Tokushi Co., Ltd.), Aronix M-1960 (manufactured by Toagosei Co., Ltd.), Art Resin UN-3320HA, UN-3320HC, UN-3320HS, UN -904 (manufactured by Negami Kogyo Co., Ltd.), NK Oligo U-4HA, U-15HA (manufactured by Shin-Nakamura Chemical Co., Ltd.), etc., trifunctional or more urethane acrylate compounds, Aronix M-8100, M-8030, M -9050 (manufactured by Toagosei Co., Ltd., KRM-8307 (manufactured by Daicel Cytec Co., Ltd.)) Things like can be suitably used. Particularly DPHA and PET-30 is preferably used.

  Furthermore, resins having three or more (meth) acryloyl groups, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins And oligomers or prepolymers such as polyfunctional compounds such as polyhydric alcohols.

  Further, dendrimers described in JP-A-2005-76005 and JP-A-2005-36105 and norbornene ring-containing monomers as described in JP-A-2005-60425 can also be used.

  A silane coupling agent having a polymerizable group can be used because of its excellent binding property to metal oxide fine particles, and a silane compound having a (meth) acryloxy group can be preferably used. For example, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxypropyldimethylmethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 2- (meth) acryloxyethyltrimethoxysilane, 2- (meth) acryloxyethyltriethoxysilane, 4- (meth) acryloxybutyltrimethoxysilane, 4- (Meth) acryloxybutyltriethoxysilane can be raised. Specifically, KBM-503, KBM-5103, X-40 (manufactured by Shin-Etsu Chemical Co., Ltd.), and silane coupling agents X-12-1048, X-12-1049, X described in JP-A-2014-123091 -12-1050 (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used.

  Two or more polyfunctional monomers may be used in combination. Polymerization of the monomer having an ethylenically unsaturated group can be performed by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.

<Dispersant>
The antireflection layer of the antireflection film of the present invention may contain a dispersant from the viewpoint of preventing aggregation of particles. The dispersant is not particularly limited, but is preferably an anionic compound such as a sulfate or phosphate, a cationic compound such as an aliphatic amine salt or a quaternary ammonium salt, a nonionic compound or a polymer compound. And a steric repulsion group are more preferred because they have a high degree of freedom in selection.
A commercial item can also be used as a dispersing agent. For example, DISPERBYK160, DISPERBYK161, DISPERBYK162, DISPERBYK163, DISPERBYK164, DISPERBYK166, DISPERBYK167, DISPERBYK171, DISPERBYK180, DISPERBYK182, DISPERBYK2000, DISPERBYK2001, DISPERBYK2164, Bykumen, BYK-P104, BYK-P104S, BYK-220S, Anti-Terra203, Anti-Terra204, Anti-Terra 205 (manufactured by Big Chemie Japan Co., Ltd.), Solsperse 20000, Solsperse 55000 (manufactured by Nippon Lubrizol Co., Ltd.), EFKA4310, EFKA4320 (BASF JA) Made emissions Co., Ltd.), and the like.
When the antireflection layer contains a dispersant, the content of the dispersant is preferably 0.01% by mass or more and 20% by mass or less, and 0.05% by mass or more and 10% by mass or less with respect to the amount of particles. More preferably, it is 0.1% by mass or more and 5% by mass or less.

<Leveling agent>
The antireflection layer of the antireflection film of the present invention may contain a leveling agent (also referred to as an antifouling agent).
As a specific example of the leveling agent, a conventionally known leveling agent such as fluorine-based or silicone-based can be used. The coating composition for forming an antireflection layer to which a leveling agent is added can impart coating stability, slipperiness, antifouling property, and scratch resistance to the coating film surface during coating or drying.

In the antireflection film of the present invention, the integrated reflectance is preferably 3% or less over the entire wavelength range of 380 to 780 nm, and more preferably 2% or less.
The antireflection film of the present invention preferably has a haze value of 5% or less, more preferably 3% or less.

[Hard coat layer]
In the present invention, a hard coat layer may be provided between the plastic substrate and the permeation layer.
The hard coat layer can be formed of the same material as the binder resin of the antireflection layer.
In order to form a permeation layer when an antireflection layer is laminated on the hard coat layer, a (meth) acrylate compound having a molecular weight of 400 or less can permeate when the antireflection layer forming composition is applied. A method in which the hard coat layer is half-cured in advance and is fully cured after the penetration layer is formed is preferable. If produced using such a method, it is possible to provide hard coat properties as well as antireflection properties.

From the viewpoint of imparting sufficient durability and impact resistance to the film, the thickness of the hard coat layer is usually about 0.5 μm to 50 μm, and preferably 1 μm to 20 μm.
Further, the strength of the hard coat layer is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test. Furthermore, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

<Other ingredients>
In addition to the above components, a solvent, a polymerization initiator, an antistatic agent, an antiglare agent, and the like can be appropriately added to the coating composition for forming a hard coat layer. Furthermore, various additives, such as a reactive or non-reactive leveling agent and various sensitizers, may be mixed.

<Solvent of coating composition for forming hard coat layer>
Specific examples of the solvent include isopropanol (IPA), methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), toluene and the like.

<Polymerization initiator>
If necessary, radicals and cationic polymerization initiators may be appropriately selected and used. These polymerization initiators are decomposed by light irradiation and / or heating to generate radicals or cations to advance radical polymerization and cationic polymerization.

<Antistatic agent>
Specific examples of the antistatic agent include a conventionally known antistatic agent such as a quaternary ammonium salt, a conductive polymer, and conductive fine particles within a range in which the permeation layer can be formed when the antireflection layer is laminated. Can be used.

<Anti-glare agent>
Anti-glare agents such as styrene beads (refractive index 1.59), polymethyl methacrylate beads (refractive index 1.49), and fine anti-glare agents such as methyl methacrylate-styrene copolymer are conventionally known anti-glare agents. May be used as long as the permeation layer can be formed when the antireflection layer is laminated. When using a fine grain anti-glare agent, the addition amount is preferably 2 to 30 parts by mass, more preferably 10 to 25 parts by mass with respect to 100 parts by mass of the curable resin composition.

<Refractive index modifier>
For the purpose of controlling the refractive index of the hard coat layer, the binder of the hard coat layer is formed with a permeation layer when a high refractive index monomer or inorganic particles or both are laminated with an antireflection layer as a refractive index adjusting agent. Can be added as much as possible. In addition to the effect of controlling the refractive index, the inorganic particles also have the effect of suppressing cure shrinkage due to the crosslinking reaction. In the present invention, after the hard coat layer is formed, a polymer formed by polymerizing the polyfunctional monomer and / or the high refractive index monomer and the like and inorganic particles dispersed therein are referred to as a binder.

<Leveling agent>
As the leveling agent, the same as the antireflection layer can be used. . The coating composition for forming a hard coat layer to which a leveling agent is added can impart coating stability to the coating film surface during coating or drying, and an antireflection layer is laminated to form a permeation layer evenly. In order to improve the scratch resistance, a compound that is extracted to the upper layer and hardly remains on the surface of the functional layer when a coating solution for forming an antireflection layer is applied is preferable. For example, a compound described in Japanese Patent No. 4474114 Etc. can be preferably used.

[Method for producing antireflection film]
The production method of the antireflection film of the present invention is as follows:
A plastic substrate, a permeation layer, and an antireflection layer containing metal oxide fine particles having an average primary particle size of 50 nm or more and 250 nm or less and a thickening compound in this order, and the antireflection layer includes the plastic substrate. A method for producing an antireflection film having a moth-eye structure having a concavo-convex shape formed by the metal oxide fine particles on the surface opposite to the side interface,
A functional layer provided on a plastic substrate or a plastic substrate, a thickening compound, a (meth) acrylate compound having a molecular weight of 400 or less, metal oxide fine particles having an average primary particle size of 50 nm or more and 250 nm or less, A composition for forming an antireflection layer containing a solvent is applied, the (meth) acrylate compound is allowed to permeate into the plastic substrate or a functional layer provided on the plastic substrate, and the metal oxide fine particles are introduced into the functional layer. Projecting from the surface opposite to the plastic substrate side interface;
Polymerizing the (meth) acrylate compound to form a permeation layer containing a polymer of the (meth) acrylate compound, and an antireflection layer having a moth-eye structure formed by the metal oxide fine particles;
It is a manufacturing method of the antireflection film which has this.
In the above production method, the solvent is volatilized by heating or the like.
Details of each component in the composition for forming an antireflection layer are as described above.

(Solvent with permeability to plastic substrate)
The solvent (substrate permeable solvent) having permeability to the plastic substrate in the present invention will be described.
The solvent having permeability to the plastic substrate is a solvent having a solubility to the surface of the plastic substrate.
Since the solvent has a solubility to the surface of the plastic substrate, a (meth) acrylate compound having a molecular weight of 400 or less penetrates into the plastic substrate, and a moth-eye structure can be uniformly formed.
Here, in the present invention, the solvent having the ability to dissolve the transparent substrate is a substrate film having a size of 24 mm × 36 mm (thickness 80 μm) in a 15 ml bottle containing the solvent at room temperature (25 ° C.). When the soaked solution was analyzed by gel permeation chromatography (GPC) after being soaked for 60 seconds, the base material component (if the base material has a plurality of layers, the surface It means a solvent having a peak area of (component) of 400 mV / sec or more. Alternatively, a base film with a size of 24 mm × 36 mm (thickness 80 μm) is allowed to age for 24 hours at room temperature (25 ° C.) in a 15 ml bottle containing the above solvent, and the film is completely dissolved by shaking the bottle as appropriate. What loses its shape also means a solvent having solubility in the substrate. A solvent that does not swell with respect to the base material is a base film having a size of 24 mm × 36 mm (thickness 80 μm) that is allowed to age for 24 hours at room temperature (25 ° C.) in a 15 ml bottle containing the solvent. After that, it is taken out from the solvent and measured on each side, and it becomes larger than the original size.
As the substrate-penetrating solvent, ethanol, IPA, dimethyl carbonate, methyl acetate, ethyl acetate, butyl acetate, acetone, etc. are preferably used in the case of a cellulose acylate substrate, although it varies depending on the components constituting the plastic substrate. However, it does not depend on this if it does not swell the substrate. Acetone and ethanol are more preferable because they have good compatibility with the metal oxide fine particles.
In the case of an acrylic substrate, ethanol, IPA, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, acetone, methyl ethyl ketone (MEK), cyclopentanone, cyclohexanone, methyl acetate, ethyl acetate and the like are preferable.
For example, when the functional layer has a hard coat layer, ethanol, IPA, methyl ethyl ketone (MEK), acetone and the like are preferable.

  The composition for forming an antireflection layer may contain a solvent other than the substrate-penetrating solvent.

  In the antireflection layer forming composition, from the viewpoint of imparting coating properties without inhibiting binder penetration, the content of the base material penetrating solvent is 5 masses with respect to the total mass of the antireflection layer forming composition. % Or more and 90% by mass or less is preferable.

  The solid content concentration of the antireflection layer forming composition is preferably 5% by mass or more and 90% by mass or less from the viewpoint of efficiently forming the permeation layer.

  In the composition for forming an antireflective layer, the total content of the (meth) acrylate compound, the thickening compound and the binder resin having a molecular weight of 400 or less is the composition for forming the antireflective layer from the viewpoint of efficiently forming the permeation layer. It is preferable that it is 50 mass% or more and 97 mass% or less with respect to the mass of the total solid of a thing.

<Polymerization initiator>
The composition for forming an antireflection layer may contain a polymerization initiator.
When the polymerizable compound contained in the composition for forming an antireflection layer is a photopolymerizable compound, it preferably contains a photopolymerization initiator.
As photopolymerization initiators, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, Examples include fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, and coumarins. Specific examples, preferred embodiments, commercially available products, and the like of the photopolymerization initiator are described in paragraphs [0133] to [0151] of JP-A-2009-098658, and can be suitably used in the present invention as well. it can.

  “Latest UV Curing Technology” {Technical Information Association, Inc.} (1991), p. 159, and “UV Curing System” written by Kiyomi Kato (published by the General Technology Center in 1989), p. Various examples are also described in 65-148 and are useful in the present invention.

  The content of the photopolymerization initiator in the antireflective layer forming composition is sufficiently high to polymerize the polymerizable compound contained in the antireflective layer forming composition, and low enough not to increase the starting point excessively. For the reason that the amount is set, 0.5 to 8% by mass is preferable and 1 to 5% by mass is more preferable with respect to the total solid content in the composition for forming an antireflection layer.

  A method for applying the composition for forming an antireflection layer is not particularly limited, and a known method can be used. Examples include dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, and die coating.

  When the composition for forming an antireflection layer is applied onto a plastic substrate, a solvent having permeability to the plastic substrate penetrates into the plastic substrate. At this time, a (meth) acrylate compound having a molecular weight of 400 or less also penetrates into the plastic substrate. Thereafter, the binder resin-forming polymerizable compound is cured by irradiation with ionizing radiation or heating to form a permeation layer and an antireflection layer. At this time, it is preferable to permeate so that the thickness of the permeation layer is greater than twice the thickness of the antireflection layer. By forming in this way, a uniform moth-eye structure can be formed after coating without aggregation of the particles before coating.

The content of the metal oxide fine particles in the composition for forming an antireflection layer is preferably 5% by mass or more and 50% by mass or less in the solid content, more preferably 10% by mass or more and 45% by mass or less, and 15 More preferably, it is at least 40% by mass. Above the lower limit, many convex portions of the moth-eye structure can be formed, so that the antireflection property is more easily improved. When the upper limit is below the upper limit, aggregation in the liquid hardly occurs and the moth-eye structure is easily formed.
The content of the thickening compound or the compound that becomes a thickening compound by polymerization in the composition for forming an antireflection layer is preferably 1% by mass to 95% by mass in the solid content, and preferably 5% by mass to 90% by mass. The content is more preferably 10% by mass or more and 85% by mass or less.

  Further, the content ratio of the metal oxide fine particles and the thickening compound in the composition for forming an antireflection layer is (the total of the metal oxide fine particles / thickening compound, the binder resin, and the (meth) acrylate compound having a molecular weight of 400 or less. Is preferably 10/90 to 95/5, more preferably 20/80 to 90/10, and even more preferably 30/70 to 85/15. When (mass of metal oxide fine particle / mass of thickening compound or compound which becomes polymerized thickening compound) is 10/90 or more, B / A of the concavo-convex shape of the moth-eye structure increases, and the reflectance decreases. Therefore, it is preferable. When the mass of the metal oxide fine particles / the viscosity increasing compound or the mass of the compound that is polymerized to become the viscosity increasing compound is 95/5 or less, the adhesion between the metal oxide fine particles and the substrate is increased, or the production process This is preferable because the metal oxide fine particles hardly aggregate and do not cause failure, haze, or deterioration of reflectance.

[Protective film for polarizing plate]
The antireflection film of the present invention can be used as a surface protective film for a polarizing film (protective film for polarizing plate).
Of the two polarizer protective films, the film other than the antireflection film of the present invention is preferably an optical compensation film having an optical compensation layer comprising an optically anisotropic layer. The optical compensation film (retardation film) can improve the viewing angle characteristics of the liquid crystal display screen. A known film can be used as the optical compensation film, but the optical compensation film described in JP-A-2001-100042 is preferable in terms of widening the viewing angle.

Prior to the bonding with the polarizer, the antireflection film of the present invention can be saponified. The saponification treatment is a treatment in which an optical film is immersed in a heated alkaline aqueous solution for a certain period of time and washed with water, followed by acid washing for neutralization. As long as the surface of the transparent support to be bonded to the polarizing film is hydrophilized, any processing conditions can be used. The concentration of the processing agent, the temperature of the processing agent solution, and the processing time are appropriately determined. The processing conditions are determined so that processing can be performed within 3 minutes from the need to ensure the performance. As general conditions, the alkali concentration is 3% by mass to 25% by mass, the treatment temperature is 30 ° C. to 70 ° C., and the treatment time is 15 seconds to 5 minutes. Sodium hydroxide and potassium hydroxide are preferable as the alkali species used for the alkali treatment, sulfuric acid is preferable as the acid used for the acid cleaning, and ion-exchanged water or pure water is preferable as the water used for the water cleaning.
The surface of the plastic substrate opposite to the side where the antireflection layer of the present invention is provided is saponified and bonded to a polarizer using an aqueous polyvinyl alcohol solution.

  An ultraviolet curable adhesive can also be used for bonding the antireflection film of the present invention and the polarizer. It is preferable to provide an ultraviolet curable adhesive layer on the surface of the plastic substrate opposite to the one provided with the antireflection layer of the present invention. In particular, for the purpose of improving productivity by drying for a short time, a specific ultraviolet curable resin is used. It is preferable to use and attach to a polarizer.

[Polarizer]
The polarizing plate of the present invention is a polarizing plate having a polarizer and at least one protective film for protecting the polarizer, and at least one of the protective films is the antireflection film of the present invention. The polarizer may be sandwiched between the protective film and the retardation film, or may be a combination of the protective film and the polarizer.

  Examples of the polarizer include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. The iodine-based polarizing film and the dye-based polarizing film can be generally produced using a polyvinyl alcohol film.

[cover glass]
The cover glass of the present invention has the antireflection film of the present invention as a protective film.

[Image display device]
The image display device of the present invention has the antireflection film or the polarizing plate of the present invention.
The antireflection film and polarizing plate of the present invention are preferably used for image display devices such as liquid crystal display devices (LCD), plasma display panels (PDP), electroluminescence displays (ELD), and cathode ray tube display devices (CRT). In particular, a liquid crystal display device is preferable.
In general, a liquid crystal display device has a liquid crystal cell and two polarizing plates arranged on both sides thereof, and the liquid crystal cell carries a liquid crystal between two electrode substrates. Furthermore, one optically anisotropic layer may be disposed between the liquid crystal cell and one polarizing plate, or two optically anisotropic layers may be disposed between the liquid crystal cell and both polarizing plates. The liquid crystal cell is preferably in TN mode, VA mode, OCB mode, IPS mode or ECB mode.

  The present invention will be described more specifically with reference to the following examples. The materials, reagents, amounts and ratios of substances, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.

[Synthesis of Silica Particles a-1]
A 200 L reactor equipped with a stirrer, a dropping device and a thermometer was charged with 67.54 kg of methyl alcohol and 26.33 kg of 28% by mass aqueous ammonia (water and catalyst), and the liquid temperature was kept at 33 ° C. while stirring. Adjusted. Meanwhile, a dropping device was charged with a solution prepared by dissolving 12.70 kg of tetramethoxysilane in 5.59 kg of methyl alcohol. While maintaining the liquid temperature in the reactor at 33 ° C., the above solution was dropped from the dropping device over 1 hour, and after completion of the dropping, stirring was further performed for 1 hour while maintaining the liquid temperature at the above temperature. Hydrolysis and condensation of methoxysilane was performed to obtain a dispersion containing a silica particle precursor. This dispersion was subjected to air-drying under the conditions of a heating tube temperature of 175 ° C. and a reduced pressure of 200 torr (27 kPa) using an instantaneous vacuum evaporation apparatus (Crox System CVX-8B type manufactured by Hosokawa Micron Co., Ltd.). Particles a-1 were obtained, the average primary particle size was 200 nm, the particle size dispersion (Cv value) was 3.5%, and the indentation hardness was 330 MPa.

[Preparation of Silica Particles a-2]
25 kg of silica-based hollow fine particle dispersion sol (Catalyst Kasei Kogyo Co., Ltd .: Thruria 1420-120, average particle size 120 nm, concentration 20.5 wt%, dispersion medium: isopropanol, particle refractive index 1.20) in a crucible Then, isopropanol was evaporated in an oven at 100 ° C. to obtain silica particles a-2. The average primary particle size of the obtained silica particles was 120 nm, and the degree of particle size dispersion (Cv value) was 5.0%. The indentation hardness was 300 MPa.

[Preparation of calcined silica particles b-1]
5 kg of silica particles a-1 were placed in a crucible, fired at 900 ° C. for 1 hour using an electric furnace, cooled, and then ground using a grinder to obtain pre-classified fired silica particles. Furthermore, calcination silica classification b-1 was obtained by performing crushing and classification using a jet crushing and classifying machine (IDS-2 type, manufactured by Nippon Puma Co., Ltd.). The average particle diameter of the obtained silica particles was 200 nm, and the degree of dispersion (Cv value) of the particle diameter was 3.5%. The indentation hardness was 400 MPa.

[Production of Silane Coupling Agent-treated Silica Particles c-1]
5 kg of pre-classified sintered silica particles b-1 were charged into a 20 L Henschel mixer (FM20J type, manufactured by Mitsui Mining Co., Ltd.) equipped with a heating jacket. A solution prepared by dissolving 45 g of 3-acryloxypropyltrimethoxysilane (KBM5103 manufactured by Shin-Etsu Chemical Co., Ltd.) in 90 g of methyl alcohol was added dropwise to the stirred silica particles b-1. Then, it heated up to 150 degreeC over about 1 hour, mixing and stirring, and heat-processed by hold | maintaining at 150 degreeC for 12 hours. In the heat treatment, scrapes on the wall surface were scraped while the scraping device was always rotated in the direction opposite to the stirring blade. Moreover, the wall deposits were also scraped off using a spatula as appropriate. After heating, the mixture was cooled and pulverized and classified using a jet pulverizer to obtain silane coupling agent-treated silica particles c-1. The average primary particle size was 200 nm, and the degree of dispersion (Cv value) of the particle size was 3.7%. The indentation hardness was 400 MPa.

[Measurement of indentation hardness of metal oxide particles]
8 g of each metal oxide particle, 0.3 g of Irgacure 184 (manufactured by BASF Japan Ltd.), 7.7 g of KAYARAD PET30 (manufactured by Nippon Kayaku Co., Ltd.) were added to 91 g of ethanol, and after stirring for 10 minutes, The dispersion was carried out for 10 minutes with a sonic disperser to obtain a 15 mass% dispersion. This dispersion is applied to a glass plate at a wet application amount of about 3 ml / m ² , and an ultraviolet ray with an irradiation amount of 600 mJ / cm ² is applied with an air-cooled metal halide lamp while purging with nitrogen so that the atmosphere has an oxygen concentration of 0.1% by volume or less. Was cured by irradiation. Thereafter, it was observed with SEM that the metal oxide particles were not stacked in one or more stages. This sample was measured for indentation hardness of the metal oxide particles using a triboindenter (TI-950 manufactured by Heiditron Co., Ltd.) under the measurement conditions of a diamond indenter with a diameter of 1 μm and an indentation load of 0.05 mN.

[Preparation of silica particle dispersion]
70 parts by mass of ethanol and 30 parts by mass of the above silica particles a-1 are put into a glass mixing tank, stirred for 10 minutes, and then ultrasonically dispersed for 30 minutes while continuing the stirring, whereby silica particles having a solid content concentration of 30% Dispersion liquid a-1 was prepared. Similarly, silica particle dispersions a-2 to 4 were prepared in the same manner as silica particle dispersion a-1, except that silica particles a-1 and ethanol were changed to have the composition shown in Table 1 below. . The unit of the coating solution concentration is “mass%”.

[Preparation of composition for forming antireflection layer]
Each component was added so that it might become a composition of antireflection layer forming composition A-1 of following Table 2, the obtained composition was thrown into a mixing tank, it stirred for 60 minutes, and an ultrasonic disperser for 30 minutes And filtered through a polypropylene filter having a pore size of 5 μm to obtain a coating solution A-1 for forming an antireflection layer (solid content concentration 20% by mass).
In the same manner as in the composition A-1 for forming an antireflection layer, each component was mixed so as to have the composition shown in Table 2 below, and adjusted so that the composition ratio (mass basis) shown in Table 2 was obtained. Layer forming compositions A-2 to A-13 were prepared.
In the following Table 2, the numerical value of each component represents the amount (parts by mass) added. The unit of the coating solution concentration is “mass%”.

(Measurement method of viscosity)
The viscosity of the thickening compound, the binder resin, and the (meth) acrylate compound having a molecular weight of 400 or less was measured using a thermal rheometer Physica MCR301 (manufactured by Anton Paar) at a heating temperature of 100 ° C. and a shear rate of 17.8 (1 / s). It was measured.

The compounds used are shown below.
DPHA ・ ・ KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.
# 802 Biscoat # 802 manufactured by Osaka Organic Chemical Industry Co., Ltd.
PET30 ・ ・ KAYARAD PET30 manufactured by Nippon Kayaku Co., Ltd.
U-4HA ·· NK Oligo U-4HA manufactured by Shin-Nakamura Chemical Co., Ltd.
A-TMPT, Shin-Nakamura Chemical Co., Ltd. NK ester A-TMPT
BMR made by GMR, NOF Corporation GMR
BR-85--Mitsubishi Rayon Co., Ltd. PMMA Dianar BR-85
UR-8300 ・ ・ Toyobo Co., Ltd. urethane modified copolymer polyester resin Byron UR-8300
Irgacure 184, a photopolymerization initiator manufactured by BASF Japan Ltd.

[Example 1]
[Preparation of antireflection film]
As a base material having a thickness of 100 μm, on a PET (Cosmo Shine A4100, manufactured by Toyobo Co., Ltd.), a coating solution A-1 for forming an antireflection layer is applied at a wet coating amount of about 2.8 ml / m ² using a gravure coater. After coating and drying at 120 ° C. for 5 minutes, the film is cured by irradiation with an ultraviolet ray with an irradiation amount of 600 mJ / cm ² with an air-cooled metal halide lamp while purging with nitrogen so that the atmosphere has an oxygen concentration of 0.1% by volume or less. Prevention film A-1 was produced. At this time, the wet coating amount was finely adjusted to measure the particle occupancy, and the highest one was adopted as the antireflection film A-1. The base material is changed from PET to a cellulose triacetate film (TG40UL, manufactured by Fuji Film Co., Ltd., tack), and the antireflection film A-2 is applied in the same manner as described above using the coating solution A-1 for forming an antireflection layer. Produced. Further, the substrate is changed from PET to a cellulose triacetate film (TG40UL, manufactured by Fuji Film Co., Ltd., tack), and instead of the antireflection layer-forming coating solution A-1, an antireflection layer-forming coating solution A-2 to Antireflection films A-3 to A-14 were prepared in the same manner except that A-13 was used and the wet coating amount was the same as when antireflection film A-1 was prepared.

(Evaluation of antireflection film)
Various characteristics of the antireflection film were evaluated by the following methods. The results are shown in Table 3.

(Confirmation of penetration layer)
The cross section of the sample cut out to about 3 mm square was thinned until a section of several 10 nm was produced by microtome and electrolytic polishing, and observed with a TEM (transmission electron microscope) to observe the presence or absence of the permeation layer.

(Integral reflectance)
The back surface of the antireflection film (cellulose triacetate film side) is roughened with sandpaper, then treated with black ink, and the back surface reflection is eliminated. The adapter is attached to the spectrophotometer V-550 (manufactured by JASCO Corporation). With ARV-474 attached, the integrated reflectance at an incident angle of 5 ° was measured in the wavelength region of 380 to 780 nm, and the average reflectance was calculated to evaluate the antireflection property.

(B / A, half width of A distribution)
The antireflection film sample was cut with a microtome to obtain a cross section, and the cross section was etched for 10 minutes after carbon deposition. Using a scanning electron microscope (SEM), 20 fields of view were observed and photographed at a magnification of 5000 times. In the obtained image, at the interface between the air and the sample, the distance A between the vertices of the adjacent convex portions and the distance B between the vertices of the adjacent convex portions and the concave portion are measured by 100 points, and B / A It was calculated as an average value. The half-value width of the A distribution was also calculated.

(Steel wool scratch resistance evaluation)
A rubbing test was performed on the surface of the antireflection layer of the antireflection film using a rubbing tester to obtain an index of scratch resistance.
Evaluation environmental conditions: 25 ° C., 55% RH
Rubbing material: Steel wool (Nippon Steel Wool Co., Ltd., gelled No. 0000)
Wrap around the tip (1 cm x 1 cm) of the tester that comes into contact with the sample. Band fixing Movement distance (one way): 13 cm,
Rubbing speed: 13 cm / second,
Load: 150 g / cm ²
Tip contact area: 1 cm × 1 cm,
Number of rubs: 10 reciprocations The oily black ink was applied to the back side of the rubbed sample and visually observed with reflected light to evaluate the scratches on the rubbed part.
A: Even if you look very carefully, no scratches are visible.
B: When looked very carefully, weak scratches are visible, but they are slight and not a problem.
C: A weak flaw can be seen if looked carefully, but it does not matter. D: A moderate flaw is seen and the flaw is conspicuous.
E: There are scratches that can be seen at first glance and are very conspicuous

(Haze)
The total haze value (%) of the obtained film was measured according to JIS-K7136. Nippon Denshoku Industries Co., Ltd. haze meter NDH4000 was used for the apparatus.

  As shown in Table 3, in the antireflection sample of the present invention, a moth-eye structure and a permeation layer could be confirmed, and both exhibited excellent reflectance and scratch resistance. In the samples (A-6, 7, 8, 10) using the urethane compound as the thickening compound, it can be seen that the reflectance and haze are particularly low, and the aggregation of particles can be effectively suppressed. Moreover, when a thickening compound serves also as a binder function, it turns out that it is excellent in especially abrasion resistance (A-4-6, 11-13). On the other hand, in Comparative Sample A-1, there is no haze and the particles are not agglomerated, but since there is no osmotic layer, the moth-eye structure cannot be formed and the reflectance is high. Even in Comparative Example Sample A-2, since there is no (meth) acrylic compound having a molecular weight of 400 or less, the permeation layer is thin, the moth-eye structure is unclear, and the reflectance is high. In Comparative Sample A-14, since there is no thickening compound, the particles aggregate and the reflectance and haze are deteriorated.

[Example 2]
[Production of plastic substrate with hard coat layer]
(Preparation of composition for forming hard coat layer)
Into the mixing tank, 10.5 parts by mass of methyl acetate, 10.5 parts by mass of MEK, 22.52 parts by mass of PET30, 6.30 parts by mass of urethane monomer (U-4HA), 0.84 parts by mass of Irgacure 184 are added and stirred. Then, the mixture was filtered through a polypropylene filter having a pore diameter of 0.4 μm to obtain a hard coat layer composition B-1 (solid content concentration: 58 mass%).
Similarly, a hard coat layer composition B-2 was produced in the same manner as the hard coat layer composition B-1, except that the ratio was changed to the composition shown in Table 4. The numerical value of each component of Table 4 is a mass part.

(Production of plastic substrate with hard coat layer)
On the cellulose triacetate film (TG40UL, manufactured by FUJIFILM Corporation), the hard coat layer coating solution B-1 was applied using a gravure coater. After drying at 60 ° C., a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) is used while purging with nitrogen so that the oxygen concentration becomes 1% by volume, and an irradiation dose of 20 mJ / cm ² . The coating layer was cured by irradiating with ultraviolet rays to form a hard coat layer having a film thickness of 6 μm, and a plastic substrate B-1 with a hard coat layer was produced.
Similarly, a plastic substrate B-2 with a hard coat layer was produced in the same manner except that the hard coat layer coating solution B-1 was changed to the hard coat layer coating solution B-2. Further, a plastic substrate B- with a hard coat layer was prepared in the same manner except that the hard coat layer coating solution B-1 was changed to a hard coat layer coating solution B-2 and the irradiation amount was changed to 300 mJ / cm ^2. 3 was produced.

[Preparation of antireflection film]
(Preparation of composition for forming antireflection layer)
In the same manner as in the antireflection layer forming composition A-1 of Example 1, the antireflection layer forming composition A-12 was applied onto the film samples B-1 to B-3 using a gravure coater at 120 ° C. After drying for 5 minutes, the film is cured by irradiating with an ultraviolet ray with an irradiation amount of 600 mJ / cm ² with an air-cooled metal halide lamp while purging with nitrogen so that the oxygen concentration becomes 0.1% by volume or less, and antireflection film B-1 -B-3 was produced.

(Pencil hardness)
The pencil hardness evaluation described in JIS K5400 was performed. The antireflection film sample was conditioned at a temperature of 25 ° C. and a humidity of 60% RH for 3 hours, then tested on the antireflection layer surface using a test pencil specified in JIS S6006, and evaluated according to the following criteria.
A: After the test you can't see the rest B: You can see the weak after the test but there is no problem

  Samples B-1 and B-2 showed good reflectance and scratch resistance even when the plastic substrate was a substrate having a hard coat layer. Furthermore, even in the pencil hardness 2H test, the scratch was weak and was an excellent level. On the other hand, in Comparative Sample B-3, the base material when the antireflection layer-forming coating solution was applied was not in a semi-cured state, so that the osmotic layer was not formed, and the reflectance deteriorated.

DESCRIPTION OF SYMBOLS 1 Plastic base material 2 Antireflection layer 3 Metal oxide fine particle 4 Binder resin 5 Penetration layer 10 Antireflection film A Distance between the vertexes of adjacent convex parts B Distance between the center between the vertexes of adjacent convex parts and the concave parts

Claims (20)

An antireflection film having a plastic substrate, a permeation layer, an antireflection layer containing metal oxide fine particles having an average primary particle size of 50 nm to 250 nm and a thickening compound in this order,
The permeation layer includes a polymer of a (meth) acrylate compound having a molecular weight of 400 or less,
The antireflection layer is an antireflection film having a moth-eye structure having an uneven shape formed by the metal oxide fine particles.   The antireflection film according to claim 1, wherein the antireflection layer further contains a binder resin.   The antireflection film according to claim 1, wherein the thickening compound contained in the antireflection layer also serves as a binder resin.   The antireflection film according to claim 1, wherein the osmotic layer further contains the thickening compound.   The antireflection film according to claim 4, wherein the concentration of the thickening compound in the permeation layer is lower than the concentration of the thickening compound in the antireflection layer.   The concave-convex shape of the antireflection layer is such that B / A, which is a ratio of the distance A between the vertices of adjacent convex portions and the distance B between the centers of the adjacent convex portions and the concave portions, is 0.6 or more. The antireflection film according to any one of claims 1 to 5.   The antireflection film according to any one of claims 1 to 6, comprising only metal oxide fine particles having an average primary particle size of 50 nm or more and 250 nm or less as the metal oxide fine particles.   The antireflection film according to claim 1, wherein the thickening compound is a urethane compound.   The antireflection film according to claim 8, wherein the urethane compound is a tetrafunctional or higher urethane (meth) acrylate.   The anti-reflection film according to claim 1, wherein the thickening compound has a viscosity at 100 ° C. of 15 to 100,000 mPa · s.   The said plastic base material is a base material containing a cellulose acylate, The antireflection film of any one of Claims 1-10.   The antireflection film according to claim 1, wherein the metal oxide fine particles are silica particles.   The antireflection film according to claim 1, wherein the indentation hardness of the metal oxide fine particles is 400 MPa or more.   The antireflection film according to any one of claims 1 to 13, wherein the metal oxide fine particles are fired silica particles whose surface is modified with a compound having a (meth) acryloyl group.   The antireflection film according to any one of claims 6 to 14, wherein a half-value width of the distribution of the distance A is 200 nm or less.   The polarizing plate which has an antireflection film of any one of Claims 1-15 as a protective film for polarizing plates.   A cover glass having the antireflection film according to any one of claims 1 to 15 as a protective film.   The image display apparatus which has an antireflection film of any one of Claims 1-15, or the polarizing plate of Claim 16. A plastic substrate, an infiltration layer, and an antireflection layer containing metal oxide fine particles having an average primary particle size of 50 nm or more and 250 nm or less and a thickening compound in this order, and the antireflection layer includes the plastic substrate. A method for producing an antireflection film having a moth-eye structure having a concavo-convex shape formed by the metal oxide fine particles on the surface opposite to the side interface,
A functional layer provided on a plastic substrate or a plastic substrate, a thickening compound, a (meth) acrylate compound having a molecular weight of 400 or less, metal oxide fine particles having an average primary particle size of 50 nm or more and 250 nm or less, An antireflection layer-forming composition containing a solvent is applied, the (meth) acrylate compound is infiltrated into the plastic substrate or a functional layer provided on the plastic substrate, and the metal oxide fine particles are Projecting from the surface opposite to the plastic substrate side interface;
Polymerizing the (meth) acrylate compound to form a permeation layer containing a polymer of the (meth) acrylate compound and an antireflection layer having a moth-eye structure formed by the metal oxide fine particles;
The manufacturing method of the antireflection film which has this.   The method for producing an antireflection film according to claim 19, wherein the composition for forming an antireflection layer has a viscosity at 100 ° C. of 15 to 100 mPa · s.

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