WO2024080149A1

WO2024080149A1 - Anti-reflection film, liquid composition, liquid composition group, and method for manufacturing anti-reflection film

Info

Publication number: WO2024080149A1
Application number: PCT/JP2023/035315
Authority: WO
Inventors: 寿雄今井; 一瞳増田
Original assignee: 日本板硝子株式会社
Priority date: 2022-10-11
Filing date: 2023-09-27
Publication date: 2024-04-18

Abstract

An anti-reflection film 1a is a film provided on a substrate 3. The anti-reflection film 1a is provided with a first layer 11 and a second layer 12 in this order from the surface side. The first layer 11 has a refractive index n_L1 of 1.10-1.35 and a thickness t_L1 of 80-150 nm. The second layer 12 has a refractive index n_L2 of 1.30-1.55 and a thickness t_L2 of 25 nm or less.

Description

Anti-reflective film, liquid composition, liquid compositions, and method for producing anti-reflective film

The present invention relates to an anti-reflective film, a liquid composition, a group of liquid compositions, and a method for producing an anti-reflective film.

　Technologies for preventing or reducing light reflection from the surface of an object are known.

For example, Patent Document 1 describes a substrate on whose surface a coating containing specific hollow spherical silica-based particles and a matrix for forming a coating is formed. The silica-based particles have a cavity formed inside an outer shell having fine pores, and a solvent or gas is contained within the cavity. Since the silica-based particles have a low refractive index, the coating also has a low refractive index, and the coating has excellent anti-reflection performance.

Patent Document 2 describes an anti-reflection film having a hard coat layer, a high refractive index layer, and a low refractive index layer from the lower layer side on the surface of an organic film. The high refractive index layer is a synthetic resin thin film containing fine particles of a metal oxide such as _ZrO2 . The synthetic resin is an ultraviolet or electron beam curable synthetic resin.

Patent Document 3 describes an anti-reflection laminate including a coating film formed in one coat using a coating composition in which low refractive index particles and medium to high refractive index particles are dispersed in a binder resin. Silica particles treated with a fluorine-based compound are used as the low refractive index particles. As a result, due to the difference in specific gravity, the low refractive index particles are unevenly distributed in the upper and middle parts of the coating film, and the medium to high refractive index particles are unevenly distributed in the middle and lower parts.

JP 2001-233611 A JP 2001-350001 A JP 2007-272132 A

The techniques described in Patent Documents 1 to 3 have room for reexamination from the viewpoint of anti-reflection performance. The present invention provides a novel anti-reflection film that is advantageous from the viewpoint of anti-reflection performance.

The present invention relates to
An anti-reflection film provided on a substrate,
The antireflection film includes a first layer and a second layer in this order from a front surface side of the antireflection film,
The first layer has a refractive index n _L1 between 1.10 and 1.35 and a thickness between 80 nm and 150 nm;
The second layer has a refractive index n _L2 of 1.30 to 1.55 and a thickness of 25 nm or less.
Provide an anti-reflective coating.

The above anti-reflective coating is advantageous in terms of anti-reflective performance.

FIG. 1 is a cross-sectional view showing an example of an anti-reflection film according to the present invention. FIG. 2 is a side view showing an example of an optical component provided with an anti-reflection coating according to the present invention. FIG. 3A is a cross-sectional view showing another example of the antireflection film according to the present invention. FIG. 3B is a cross-sectional view showing still another example of the antireflection film according to the present invention. FIG. 3C is a cross-sectional view showing a state of first hollow fine particles in the antireflection coating shown in FIG. 3A. FIG. 3D is a cross-sectional view showing a state of first hollow fine particles in the antireflection coating shown in FIG. 3A. FIG. 4 is a cross-sectional view showing still another example of the antireflection film according to the present invention. FIG. 5 is a graph showing the reflection spectrum of the antireflection film according to Example 1. As shown in FIG. FIG. 6 is a graph showing the reflection spectrum of the antireflection film according to Example 4. FIG. 7 is a graph showing the reflection spectrum of the antireflection film according to Example 5. FIG. 8 is a graph showing the reflection spectrum of the antireflection film according to Example 7. FIG. 9 is an SEM image of a cross section of the antireflection coating according to Example 1. FIG. 10 is an SEM image of a cross section of the antireflection coating according to Example 5.

Below, an embodiment of the present invention will be described with reference to the attached drawings. Note that the following description is an example of the present invention, and the present invention is not limited to the following embodiment.

An anti-reflection film is provided, for example, on the surface of an optical article. Examples of optical articles on which an anti-reflection film is provided include optical elements such as optical filters, lenses, and polarizers, various displays, glasses, and transparent shields. It is possible to form an anti-reflection film that suppresses the reflection of light from the surface of the optical article by coating an optical article with a material having a predetermined refractive index. For example, anti-reflection films can play an important role in fields or applications such as optical elements such as lenses and filters, windows and structural materials used in buildings, windshields for automobiles, and shields such as helmets and goggles. The anti-reflection film can suppress the reflection of light from the surface of the article or substrate, and can increase the amount of light transmitted through the article or substrate. Here, the anti-reflection film is composed of a single layer or multiple layers made of different materials, fabrication conditions, and methods, and is provided on the surface of the article or substrate to prevent or reduce the reflection of light from the surface of the article or substrate.

For example, the reflectance of one surface of a transparent dielectric made of glass or resin is usually about 4 to 5%. Therefore, the overall reflectance considering the reflection on the front surface and the reflection on the back surface can be 8 to 10% for a single plate-shaped transparent dielectric. For example, an imaging device such as a camera usually has an optical system including multiple lenses made of transparent dielectrics such as glass and resin, and the amount of reflection from the lens surfaces in the optical system is very large, which greatly reduces the amount of light reaching the light receiving surface of an imaging element such as a CCD or CMOS. Furthermore, the reflected light from the surface of a lens made of a transparent dielectric such as glass or resin is repeatedly reflected or refracted by the internal structure of the imaging device or the surfaces of other lenses before reaching the light receiving surface of the imaging element, which can cause undesirable phenomena such as ghosts or flares. Therefore, it is important to form an anti-reflection film on the surface of an article or substrate that performs functions such as transmitting or refracting light, and to suppress reflection on the surface.

As shown in FIG. 1, the anti-reflection film 1a is a film provided on a substrate 3. The anti-reflection film 1a includes a first layer 11 and a second layer 12 in this order from the surface side. The substrate 3 may be an article for transmitting light in a desired wavelength range and using it. The substrate 3 may be a transparent dielectric. The second layer 12 is disposed between the first layer 11 and the substrate 3 in the thickness direction of the anti-reflection film 1a. The first layer 11 has a refractive index n _L1 of 1.10 to 1.35 and a thickness t _L1 of 80 nm to 150 nm. The second layer 12 has a refractive index n _L2 of 1.30 to 1.55 and a thickness t _L2 of 25 nm or less. With this configuration, the anti-reflection film 1a can exhibit high anti-reflection performance. The refractive indexes n _L1 and n _L2 are refractive indices at the D line (wavelength 589.3 nm).

In the antireflection coating 1a, for example, in the reflection spectrum showing the wavelength and the reflectance for light having a wavelength of 300 nm to 1200 nm incident at an incident angle of 5°, the minimum reflectance r _min ^300-1200 within the wavelength range of 300 nm to 1200 nm can be 1% or less. The reflectance r _min ^300-1200 is preferably 0.5% or less, and more preferably 0.2% or less. Hereinafter, unless otherwise specified, the reflectance of an antireflection coating or the like is the reflectance determined from the reflection spectrum when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 5°.

In the antireflection coating 1a, the minimum reflectance r _min ^400-800 in the wavelength range of 400 nm to 800 nm is not limited to a specific value. The reflectance r _min ^400-800 is, for example, 0.5% or less. In this case, the antireflection coating 1a is more likely to exhibit high antireflection performance. The reflectance r _min ^400-800 is preferably 0.2% or less.

In the antireflection coating 1a, the range λ _range/2.5 , in which the reflectance is 2.5% or less within the wavelength range of 300 nm to 1200 nm, is not limited to a specific value. The range λ _range/2.5 is, for example, 400 nm or more. This makes it easier for the antireflection coating 1a to exhibit high antireflection performance. The range λ _range/2.5 may be 450 nm or more, or may be 500 nm or more. Hereinafter, unless otherwise specified, the wavelength and wavelength range corresponding to a predetermined reflectance are also wavelengths determined from the reflection spectrum.

In the antireflection film 1a, the range λ _range/1.0 in which the reflectance is 1.0% or less in the wavelength range of 300 nm to 1200 nm is not limited to a specific value. The range λ _range/1.0 is, for example, 250 nm or more. This makes it easier for the antireflection film 1a to exhibit high antireflection performance. The range λ _range/1.0 may be 300 nm or more, 350 nm or more, or 400 nm or more.

As shown in FIG. 1, in the anti-reflection film 1a, the second layer 12 is formed, for example, in direct contact with the surface of the substrate 3. In the thickness direction of the anti-reflection film 1a, another layer or film may be disposed between the second layer 12 and the surface of the substrate 3.

In the antireflection film 1a, for example, the condition n _L1 <n _L2 is satisfied, in which case the antireflection film 1a is more likely to exhibit high antireflection performance.

The thickness t _L2 of the second layer is preferably 15 nm or less, more preferably 10 nm or less, and even more preferably 5 nm or less, so that the antireflection film 1a can more easily exhibit high antireflection performance.

As shown in FIG. 1, in the antireflection film 1a, the first layer 11 and the second layer 12 form a first multi-layer structure 10. The thickness t _LL of the first multi-layer structure 10 is, for example, 100 nm to 160 nm. In this case, the antireflection film 1a is more likely to exhibit high antireflection performance. When the substantial or representative refractive index n _LD and thickness t _LL of the first multi-layer structure 10 at the D line (wavelength λ _D : 589.3 nm) satisfy the condition t _LL = λ _D / (4n _LD ), the reflectance at the D line is minimized. For this reason, it is advantageous from the viewpoint of high antireflection performance that the thickness t _LL is 100 nm to 160 nm.

In the anti-reflection film 1a, the thickness t _LL and the arbitrary wavelength λ _X [nm] may satisfy, for example, the condition λ _X /6≦t _LL ≦λ _X /4. In this case, in the anti-reflection film 1a, the reflectance at the wavelength λ _X is likely to be low, and the wavelength range in the reflection spectrum where the reflectance is equal to or less than a predetermined value can be increased, which is advantageous. The wavelength λ _X is, for example, a specific wavelength included in the wavelength range of 400 nm to 800 nm, and may be the D line (wavelength 589.3 nm), a wavelength representative of the wavelength range of the light used, a central wavelength of the wavelength range of the light used, or the most important wavelength in the wavelength range of the light used. The most important wavelength in the wavelength range of the light used may be the wavelength corresponding to the lowest reflectance in a predetermined wavelength range.

When the refractive index of the substrate is n _sb and the refractive index of the antireflection film is n ₁ , it is possible to adjust the optical thickness of the antireflection film to 1/4 of a predetermined wavelength λ. In this case, the smaller the absolute value of n _sb -n ₁ ² , the smaller the reflectance at the wavelength λ corresponding to that refractive index. For this reason, it may be desirable from the viewpoint of reducing the reflectance that the effective refractive index of the antireflection film is low. When a low refractive index is required for the antireflection film, it is advantageous for the antireflection film to contain hollow fine particles.

As shown in FIG. 1, the first multilayer structure 10 includes, for example, first hollow fine particles 21 and a first binder 31. The first binder 31 binds the first hollow fine particles 21. With this configuration, the first layer 11 and the second layer 12 tend to have the desired refractive index and thickness, and the anti-reflection film 1a tends to exhibit high anti-reflection performance. In addition, by including the first hollow fine particles 21 in the first multilayer structure 10, as described below, the effective refractive index of the anti-reflection film 1a can be lowered, and mechanical strength such as peel resistance and abrasion resistance, as well as weather resistance such as moisture resistance, are expected to be improved. In this specification, fine particles are particles having an average particle diameter of less than 1 μm.

Even if the material forming the outer shell of the first hollow particles 21 has a predetermined refractive index, the hollow portion 21a inside can be considered to be filled with air. For this reason, the inclusion of the first hollow particles 21 in the first multilayer structure 10 tends to lower the effective refractive index. The first hollow particles 21 have, for example, a hollow balloon-type structure. The refractive index of the first hollow particles 21 is, for example, 1.10 to 1.40, preferably 1.15 to 1.40, and more preferably 1.17 to 1.35. Note that the refractive index of the first hollow particles 21 is not the refractive index of the material forming the outer shell of the first hollow particles 21, but the effective refractive index of the first hollow particles 21 including the effect of the hollow portion 21a. The refractive index of a specific wavelength of the first hollow microparticle may be widely known, or it may be calculated by obtaining representative or average values of the approximate spherical size of the hollow microparticle, the material and thickness of the outer shell of the hollow microparticle, etc., and using, for example, an effective medium approximation method using the Bruggemann equation.

The material forming the outer shell of the first hollow microparticle 21 is not limited to a specific material. The material may be an inorganic material, an organic material, or an organic-inorganic hybrid material. Examples of inorganic materials forming the outer shell of the first hollow microparticle 21 are silicon oxide (silica) and magnesium fluoride. Examples of organic materials forming the outer shell of the first hollow microparticle 21 are polystyrene and polyethylene. These materials may be used alone, or two or more types of materials may be mixed and used. From the viewpoint of ease of manufacturing hollow microparticles, the main component of the outer shell of the first hollow microparticle 21 is preferably silicon oxide. In this specification, the main component is the component that is contained most abundantly by mass.

The shape of the first hollow microparticles 21 is not limited to a specific shape. The first hollow microparticles 21 may be substantially spherical, may have an irregular shape, or may have a specific shape connected in a chain shape.

The average particle diameter D _p of the first hollow fine particles 21 is not limited to a specific value. The average particle diameter D _p is, for example, 5 to 200 nm. When the average particle diameter D _p is 5 nm or more, the manufacturing cost of the first hollow fine particles 21 is likely to be low. In addition, it is possible to prevent the refractive index from being insufficiently reduced due to the small volume of the hollow portion 21a. When the average particle diameter D _p is 200 nm or less, scattering is suppressed even when light is incident on the first hollow fine particles 21, and it is easy to prevent the haze of the antireflection film 1a from increasing. The size and shape of the fine particles can be confirmed and measured by observation using, for example, a scanning electron microscope (SEM). As the average particle diameter of the fine particles, an SEM image of 100,000 times the cross section perpendicular to the main surface of an article or the like on which a film containing fine particles is formed is obtained, the fine particles are identified, the shape of the fine particles is approximated to a circle, and the diameter is measured, and the arithmetic average value of the diameters of the fine particles included in a predetermined area, for example, within a 500 nm square range including all layers constituting the antireflection film, may be adopted. This method is convenient for determining the average particle diameter of the fine particles contained in an already solidified film or layer. When the shape of the fine particles is approximated to a circle in the SEM image, the circle with the smallest diameter that includes the area of each fine particle may be specified as the approximate circle.

The average particle size D _p is preferably 10 to 100 nm, and more preferably 30 to 80 nm.

The outer shell of the first hollow microparticle 21 may be crystalline, polycrystalline, or amorphous.

The thickness t _S of the outer shell of the first hollow fine particle 21 is not limited to a specific value. The thickness t _S is, for example, 1 to 50 nm. When the thickness t _S is 1 nm or more, the mechanical strength of the outer shell is likely to be high, and the hollow structure of the first hollow fine particle 21 is likely to be maintained in a desired state. When the thickness t _S is 50 nm or less, the first hollow fine particle 21 is easy to manufacture. The thickness t _S of the outer shell of the hollow fine particle may be estimated from the relationship between the substantial refractive index of the hollow fine particle, the volume of the approximate sphere of the hollow fine particle, the volume of the hollow portion, and the like, by an effective medium approximation method using the Bruggemann equation.

In the first hollow fine particles 21, the ratio t _S /D _p of the shell thickness t _S to the average particle diameter _D _p is not limited to a specific value and is, for example, _1/50 to 1/5.

The first hollow fine particles 21 may be hollow fine particles whose surfaces have been modified. For example, fine particles may be used that have been reacted in advance with a compound having a metal component, an alkyl group, and an alkoxy group in one molecule, or a hydrolyzate of such a compound. In this case, the compound may contain reactive functional groups such as amino groups, epoxy groups, methacryl groups, and vinyl groups. Compounds known as coupling agents may also be used as such compounds. Coupling agents include, for example, components such as Si, Ti, or Al. In this specification, Si is treated as a metal component.

In the manufacture of the anti-reflective film 1a, the particles for the first hollow particles 21 may be provided as a powder or as a dispersion of particles. The dispersion of particles may be in a colloidal state. For example, colloidal silica, which is a colloidal dispersion of silicon oxide particles, may be used. By using a dispersion of particles, the dispersion state of the particles is stably maintained, the haze of the anti-reflective film 1a tends to be low, and the anti-reflective film 1a tends to have high transparency. The dispersion medium of the dispersion may be alcohols, ketones, esters, ethers, aromatic hydrocarbons, or amides. Examples of alcohols are methanol, ethanol, isopropanol, butanol, and octanol. Examples of ketones are acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of esters are ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. The ethers are ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, and diethylene glycol monobutyl ether. The aromatic hydrocarbons are benzene, toluene, and xylene. Examples of amides are dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Among them, methanol, isopropanol, butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, propylene glycol monomethyl ether, toluene, and xylene are preferable as the dispersion medium.

The first hollow microparticles 21 may be Suluria 1110 (silicon oxide, average particle size (nominal) approximately 50 nm, solids concentration approximately 20% by mass) manufactured by JGC Catalysts and Chemicals, or Suluria 4110 (silicon oxide, average particle size (nominal): 50 nm to 60 nm, solids concentration approximately 20 to 25% by mass) manufactured by the same company. These are hollow microparticles whose outer shell is mainly composed of silicon oxide.

The anti-reflective film 1a contains a binder such as the first binder 31. The binder bonds the fine particles contained in the anti-reflective film 1a to each other and to the fine particles and the substrate or undercoat layer. A binder is originally a material for binding materials such as particles, pigments, and substrates within a layer, but in this specification, for example, a component that solidifies to form a uniform structure within a layer that does not contain pigments or particles is also treated as a binder.

The binder material contained in the anti-reflective film 1a is not limited to a specific material. The binder may be, for example, a compound or composition whose precursor is liquid and which hardens when heated or exposed to electromagnetic waves such as light. If the binder precursor is liquid, it is easy to prepare the precursor of the anti-reflective film 1a in the manufacture of the anti-reflective film 1a, and it is easy to add fine particles, disperse fine particles, make fine particles colloidal, or dissolve fine particles.

The binder precursor may be, for example, a monomer or oligomer having a polymerizable unsaturated group in the molecule, such as an acrylic group, a vinyl group, or an allyl group. The binder precursor may be a compound having one or more polymerizable unsaturated groups in one molecule. The binder precursor is not limited to a specific compound. Examples of the binder precursor are 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, neopentyl glycol mono(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolethane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate. The binder precursor may be a compound obtained by an addition reaction between a glycidyl group-containing compound, such as an alkyl glycidyl ether, an allyl glycidyl ether, and a glycidyl (meth)acrylate, and (meth)acrylic acid. The binder precursor may be a compound containing a polymerizable functional group, and may be a precursor of a silicone resin, an epoxy resin, a phenoxy resin, a novolac resin, a silicone acrylate resin, a melamine resin, a phenolic resin, a polyimide resin, or a urethane resin.

The binder precursor may contain a metal alkoxide having a metal component and an alkoxy group as shown in the following formula (A) or a hydrolyzate thereof: In formula (A), ^Rx and ^Ry are functional groups containing at least a carbon atom, M is a metal atom, and n and m are the numbers of functional groups substantially contained in one molecule.
R ^x _m M(OR ^y ) _n Formula (A)

The metal component is, for example, selected from the group consisting of Si, Ti, Nb, Zr, and Al. The binder precursor may desirably contain an alkoxysilane having Si and an alkoxy group represented by the following formula (B), a hydrolyzate thereof, or a polysilane obtained by polymerizing the hydrolyzate thereof. R ¹ and R ² are the same or different functional groups containing carbon atoms and hydrogen atoms, and n is an integer of 1 to 4.
R ¹ _4-n Si(OR ² ) _n Formula (B)

Such alkoxysilanes undergo hydrolysis in the presence of water, producing silanol groups (-Si-OH), which then undergo condensation polymerization to produce siloxane bonds (-O-Si-O-) between multiple molecules. This increases the molecular weight, producing a polymer, and it is relatively easy to obtain a binder containing silica or silsesquioxane. Silica is produced by the reaction of tetrafunctional alkoxysilanes in which n = 4 in formula (B). Silsesquioxanes are produced by the reaction of trifunctional alkoxysilanes in which n = 3 in formula (B).

Silica is the main component of glass. Ordinary glass requires a process of melting silica sand at a very high temperature. However, the solidification of a composition containing silica using alkoxysilane is advantageous in that it can be done at a low temperature. In addition, binders that contain alkoxysilane as part of the raw materials can contain silica, etc., so they are advantageous in terms of durability. In addition, binders that contain alkoxysilane as part of the raw materials are likely to have the desired characteristics in terms of affinity with the particles or formation of hydrogen bonds with the particles, even when containing fine particles whose main component is silicon oxide such as silica, and are expected to increase the binding strength of the fine particles. In addition, the difference in refractive index between the binder and the fine particles is likely to be small, and the transparency of a layer or film containing the binder and the fine particles is likely to be high.

The alkoxysilane contained in the binder precursor is not limited to a specific alkoxysilane. Examples of alkoxysilanes include tetramethoxysilane, tetraethoxysilane, tetra(i-propoxy)silane, trimethoxysilane, triethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, isobutyltriethoxysilane, methyltri-iso-propoxysilane, ethyltri-iso-propoxysilane, dimethoxysilane, diethoxysilane, methyldimethoxysilane, methyl Diethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldi(i-propoxy)silane, methylethyldimethoxysilane, methylethyldiethoxysilane, methylethyldi(i-propoxy)silane, methylpropyldimethoxysilane, methylpropyldiethoxysilane, methylpropyldi(i-propoxy)silane, methoxysilane, ethoxysilane, methylmethoxysilane, methylethoxysilane, dimethylmethoxysilane, dimethylethoxysilane trimethylmethoxysilane, trimethylethoxysilane, trimethyl(i-propoxy)silane, triethylmethoxysilane, triethylethoxysilane, triethyl(i-propoxy)silane, tripropylmethoxysilane, tripropylethoxysilane, tripropyl(i-propoxy)silane, methyldiethylmethoxysilane, methyldiethylethoxysilane, methyldiethyl(i-propoxy)silane, methyldipropylmethoxysilane, methyldipropylethoxysilane, methyldipropyl(i-propoxy)silane silane, ethyldimethylethoxysilane, ethyldimethyl(i-propoxy)silane, ethyldipropylmethoxysilane, ethyldipropylethoxysilane, ethyldipropyl(i-propoxy)silane, propyldimethylmethoxysilane, propyldimethylethoxysilane, propyldimethyl(i-propoxy)silane, propyldiethylmethoxysilane, propyldiethylethoxysilane, propyldiethyl(i-propoxy)silane, bis(trimethoxysilyl)methane, bis(triethoxysilyl)methane, bi Bis(trimethoxysilyl)ethane, bis(triethoxysilyl)ethane, 1,3-bis(trimethoxysilyl)propane, 1,3-bis(triethoxysilyl)propane, hexamethoxydisiloxane, hexaethoxydisiloxane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-hydroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, trifluoropropyltrimethoxysilane, trifluoropropyl Triethoxysilane, tetraacetoxysilane, tetrakis(trichloroacetoxy)silane, tetrakis(trifluoroacetoxy)silane, triacetoxysilane, tris(trichloroacetoxy)silane, tris(trifluoroacetoxy)silane, methyltriacetoxysilane, methyltris(trichloroacetoxy)silane, methyltris(trifluoroacetoxy)silane, methyldiacetoxysilane, methylbis(trichloroacetoxy)silane, methylbis(trifluoroacetoxy)silane, dimethylbis( trichloroacetoxy)silane, dimethylbis(trifluoroacetoxy)silane, methylacetoxysilane, methyl(trichloroacetoxy)silane, methyl(trifluoroacetoxy)silane, dimethylacetoxysilane, dimethyl(trichloroacetoxy)silane, dimethyl(trifluoroacetoxy)silane, trimethylacetoxysilane, trimethyl(trichloroacetoxy)silane, trimethyl(trifluoroacetoxy)silane, tetrachlorosilane, tetrabromosilane, tetrafluorosilane, trichlorosilane, tribromosilane, trifluorosilane, methyltrichlorosilane, methyltribromosilane, methyltrifluorosilane, methyldichlorosilane, methyldibromosilane, methyldifluorosilane, dimethyldichlorosilane, dimethyldibromosilane, dimethyldifluorosilane, methylchlorosilane, methylbromosilane, methylfluorosilane, dimethylchlorosilane, dimethylbromosilane, dimethylfluorosilane, trimethylchlorosilane, trimethylbromosilane, and trimethylfluorosilane. The binder or the binder precursor may be a hydrolyzate of these alkoxysilanes having silanol groups, or a compound in which the hydrolyzates of these alkoxysilanes are polymerized through siloxane bonds. The binder or the binder precursor may contain multiple alkoxysilanes, hydrolyzates of multiple alkoxysilanes, or polymers of hydrolyzates of multiple alkoxysilanes.

The alkoxysilane contained in the binder precursor may have, in addition to the alkoxy group, reactive functional groups such as acryloyl groups and epoxy groups or polymerizable unsaturated groups in one molecule. Examples of such alkoxysilanes are 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltriacetoxysilane, 3-acryloxypropyltris(trichloroacetoxy)silane, 3-acryloxypropyltris(trifluoroacetoxy)silane, 3-methacryloxypropyltriacetoxysilane, 3-methacryloxypropyltris(trichloroacetoxy)silane, 3-methacryloxypropyltris(trichloroacetoxy)silane, 3-methacryloxypropyltris(trichloroacetoxy)silane, 3-methacryloxypropyltris(trichloroacetoxy)silane, 3-methacryloxypropyltris(trifluoro ... These are 3-glycidoxypropyltris(trifluoroacetoxy)silane, 3-glycidoxypropyltris(trichloroacetoxy)silane, 3-glycidoxypropyltris(trifluoroacetoxy)silane, 3-acryloxypropyltrichlorosilane, 3-acryloxypropyltribromosilane, 3-acryloxypropyltrifluorosilane, 3-methacryloxypropyltrichlorosilane, 3-methacryloxypropyltribromosilane, 3-methacryloxypropyltrifluorosilane, 3-glycidoxypropyltrichlorosilane, 3-glycidoxypropyltribromosilane, and 3-glycidoxypropyltrifluorosilane.

The first binder 31 contains, for example, at least one selected from the group consisting of alkoxysilane, hydrolysates of alkoxysilane, and polymers of hydrolysates of alkoxysilane. This makes it easier for the anti-reflection film 1a to exhibit high anti-reflection performance.

The second layer 12 includes, for example, the first binder 31 present near the surface of the substrate 3 and a part of the outer shell of the first hollow fine particle 21 present near the surface of the substrate 3. A part of the first hollow fine particle 21 present near the surface of the substrate 3 may be in contact with the surface of the substrate 3. Therefore, the second layer 12 is almost filled with a solid and contains almost no hollow or void parts in which air exists. For example, when the main component of the outer shell of the first hollow fine particle 21 is silicon oxide and the first binder 31 contains a hydrolyzate of alkoxysilane or a polymer of the hydrolyzate, the second layer 12 can be composed of a material containing silicon oxide as the main component. In this case, the refractive index of the second layer 12 is close to the refractive index of silicon oxide or a modified product of silicon oxide. On the other hand, the first layer 11 includes the outer shell of the first hollow fine particle 21, the hollow part 21a of the first hollow fine particle 21, and the gap between the first hollow fine particles 21. Thus, air with a refractive index of about 1 exists in the first layer 11. For this reason, the first layer 11 and the second layer 12 are likely to have the desired refractive index and the desired thickness, and the condition n _L1 < n _L2 is likely to be satisfied. As the volume occupied by air in the first layer 11 increases, the refractive index n _L1 of the first layer 11 is likely to become smaller, and the condition n _L1 < n _L2 is likely to be satisfied.

The thickness of the second layer 12 is, for example, smaller than the average particle diameter _Dp of the first hollow fine particles 21. Furthermore, the thickness of the second layer 12 may be smaller than the thickness _ts of the outer shell.

The substrate 3 is not limited to a specific substrate, so long as the anti-reflection film 1a is provided on its surface. The optical properties of the anti-reflection film 1a may be determined by taking into consideration the optical properties of the substrate 3. The substrate 3 is, for example, a substrate used in an image display device such as a display. The substrate 3 may be an optical element such as an optical filter, a lens, or a diffraction element. An optical filter causes a predetermined physical change in incident light, and can perform the functions of transmission, reflection, absorption, diffusion, or a combination of these. A lens causes light to be focused or diverged by refraction. A diffraction element has unevenness on its surface or inside, and can diffract light to perform a predetermined function.

As shown in FIG. 1, the substrate 3 is, for example, flat. The substrate 3 may have a curved surface on all or part of its surface, or may have a smooth surface including irregularities. For example, when the substrate 3 is a lens, the surface of the substrate 3 may include a curved surface. In addition, the substrate 3 may be a substrate for a helmet windshield and a display screen of a head-mounted display. In this case, the entire substrate 3 is gently curved. When the substrate 3 is a diffraction element, the surface may have irregularities of the size of the wavelength of the light to be diffracted or close to that wavelength.

FIG. 2 is a side view showing an example of an optical component having a substrate 3 and an anti-reflection film 1a. As shown in FIG. 2, the substrate 3 may be a lens such as a convex lens.

The material of the substrate 3 is not limited to a specific material. The substrate 3 is, for example, a material that can function as an optical article. The substrate 3 has high transparency, and includes, for example, glass or resin. The glass is not limited to a specific glass. Examples of glass are soda-lime glass, borosilicate glass, aluminosilicate glass, (synthetic) quartz, lead glass, barium glass, phosphate glass, fluorophosphate glass, and lanthanum glass. The glass may be glass produced by the sol-gel method. In this case, it is easy to form a structure of the wavelength size of light. The raw material of the glass used in the sol-gel method is a metal and a compound having an alkoxy group.

The resin contained in the substrate 3 is not limited to a specific resin. Examples of resins include acrylic (methacrylic) resins, styrene resins, polycarbonate resins, polyolefin resins, epoxy resins, polyethylene resins, polypropylene resins, ABS resins, polyamide resins, polyacetal resins, and polyethylene terephthalate resins.

The refractive index n _SB of the substrate 3 at the D line is, for example, 1.20 to 2.50, may be 1.30 to 2.30, or may be 1.35 to 2.00.

The anti-reflective film 1a, or a layer contained in the anti-reflective film 1a, can be produced, for example, by solidifying a specific liquid composition.

The liquid composition contains a binder precursor and, if necessary, fine particles. The liquid composition may further contain an organic polymer, and examples of the organic polymer may be polyethers such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, or may be polyisocyanate compounds. As a result, when the liquid composition is cured, these organic polymers act as crosslinking agents, making it possible to improve the mechanical properties, such as hardness and scratch resistance, light resistance, or weather resistance of the anti-reflective film 1a.

A polymerization initiator may be added to the liquid composition. The polymerization initiator is selected from known polymerization initiators such as thermal radical generators, photoradical generators, thermal acid generators, and photoacid generators, depending on the reaction form of the polymerizable functional group or polymerizable monomer.

When the binder precursor partially contains alkoxysilane or its hydrolysate, the liquid composition may contain water for promoting hydrolysis, and acids (acid catalysts) or alkalis (alkali catalysts) that act as catalysts. Examples of acids (acid catalysts) are hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, formic acid, and acetic acid, and examples of alkali catalysts are ammonia, trialkylamine, sodium hydroxide, potassium hydroxide, choline, and tetraalkylammonium hydroxide. Among them, formic acid and acetic acid are organic acids that can dissolve alkoxysilane. In addition, these acids are desirable as acid catalysts because they are substantially free of halogens, have a small acid dissociation constant (pKa) (pKa = 3.7 (formic acid), 4.7 (acetic acid)), and are strong acids. When acetic acid and formic acid are used as acid catalysts, silanol groups are generated even when there is little or no water in the system, so that a polysilane structure can be formed without hydrolysis. From this viewpoint, the use of formic acid and acetic acid is also desirable. In addition, formic acid has a fairly simple structure among organic acids, making it easy to exhibit the desired properties as an acid catalyst.

The liquid composition may be prepared, for example, by dropping the catalyst into a liquid containing an alkoxysilane while stirring the liquid. This prevents the reaction in which the catalyst acts from proceeding too quickly by adding too much catalyst compound at once, making it less likely that the reaction will be biased.

The liquid composition may contain a solvent. The solvent also contributes to the dispersion of, for example, fine particles, etc., and the liquid composition is likely to have a desired viscosity in the manufacturing process of the anti-reflection film 1a. In addition, the coating work of the liquid composition or the quality of the coating film is likely to be adjusted to a desired level. The metal alkoxide compound such as alkoxysilane, which is the raw material of the binder 31, may not be easily dissolved in water required for hydrolysis immediately after mixing. For this reason, the liquid composition may contain an organic solvent that is compatible with both the metal alkoxide and water. The solvent contained in the liquid composition is not limited to a specific solvent. The solvent contained in the liquid composition may be alcohols, ketones, esters, ethers, aromatic hydrocarbons, or amides. Examples of alcohols are methanol, ethanol, isopropanol, butanol, octanol, 1-methoxy-2-propanol, and 3-methoxy-3-methyl-1-butanol. Examples of ketones are acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of esters are ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. Examples of ethers are ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, and diethylene glycol monobutyl ether. Examples of aromatic hydrocarbons are benzene, toluene, and xylene. Examples of amides are dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Organic acids such as acetic acid and formic acid may also be used as a solvent in the preparation of the liquid composition. Among these, at least one selected from the group consisting of methanol, isopropanol, butanol, 1-methoxy-2-propanol, 3-methoxy-3-methyl-1-butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, propylene glycol monomethyl ether, toluene, and xylene may be preferably used as a solvent. These solvents may be used alone, or two or more of them may be mixed and used.

The liquid composition may contain hydrophilic and hydrophobic compounds such as surfactants and silane coupling agents to prevent aggregation of the fine particles.

The liquid composition can be prepared by selecting the types of fine particles, binder precursor, solvent, catalyst, and the above compounds, adjusting the composition ratio of each component by known methods and conditions, and mixing them while causing a reaction of some of the compounds as necessary.

In the liquid composition that is the precursor of the first multilayer structure 10 of the anti-reflective coating 1a, the ratio of the mass of the solid content of the first hollow fine particles 21 to the mass of the solid content of the liquid composition is not limited to a specific value. The ratio is, for example, 80% to 99.5%. With such a configuration, the first layer 11 and the second layer 12 tend to have the desired refractive index and the desired thickness. The precursor of the first binder 31 in the liquid composition may, for example, function to bind the first hollow fine particles 21 together or to bind the first hollow fine particles 21 to the surface of the substrate 3, and the precursor of the first binder 31 contained in an amount exceeding that required for binding the first hollow fine particles may move toward the surface of the substrate 3 and solidify in the manufacture of the anti-reflective coating 1a to form a part of the second layer 12. As described above, the second layer 12 is filled with a solid containing a part of the outer shell of the hollow fine particles 21 and the first binder 31, and is a layer having a relatively high refractive index in the first multilayer structure 10. The first binder 31 contains, for example, a hydrolyzate of an alkoxysilane or a polymer thereof.

The ratio of the mass of the solid content of the first hollow microparticles 21 to the mass of the solid content of the liquid composition that is the precursor of the first multilayer structure 10 is preferably 90% or more, more preferably 95% or more, and even more preferably 99% or more.

The liquid composition, which is the precursor of the first multi-layer structure 10, contains, as a precursor of the first binder 31, at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes. In this case, the alkoxysilanes contain tetrafunctional alkoxysilanes and trifunctional alkoxysilanes, and the ratio of the amount of substance of tetrafunctional alkoxysilane to the amount of substance of trifunctional alkoxysilane is not limited to a specific value. The ratio is, for example, 1/9 to 9. In this case, the first layer 11 and the second layer 12 tend to have the desired refractive index and the desired thickness. In addition, the first multi-layer structure 10 tends to have the desired mechanical strength and high transparency.

The anti-reflective film 1a can be produced, for example, by applying a liquid composition containing first hollow fine particles 21 and at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes onto a substrate 3 and solidifying the liquid composition. The mass ratio of the first hollow fine particles 21 to the liquid composition is 80% to 99.5%. The anti-reflective film 1a contains a first layer 11 and a second layer 12 that are separated from each other. According to this method, the anti-reflective film 1a having the first layer 11 and the second layer 12 can be produced relatively easily from a single liquid composition.

The method of coating the liquid composition, which is the precursor of the anti-reflection film 1a, along the substrate 3 is not limited to a specific method. Examples of the method include roll coating, spray coating, spin coating, coating with a dispenser, coating with an inkjet, screen printing, and coating by dip. The conditions of the coating method are adjusted according to the required thickness of the coating film. For example, in the case of coating by dip, when the viscosity of the liquid composition is η [Pa·sec] and the lifting speed is v [m/sec], the thickness of the coating film, for example, the thickness t _LL of the first multi-layer structure 10, is proportional to η ^j ×v ^k . Here, the conditions j = 0.5 to 0.6 and k = 0.5 to 0.7 are satisfied. In addition, in coating by spin coating, when the rotation angular velocity is ω [radian/sec], the thickness of the coating film is proportional to η ^1/3 /ω ^2/3 .

The method of solidifying the liquid composition is not limited to a specific method. The liquid composition may be solidified according to a method that dries the coating film by heating or polymerizes the binder precursor, etc. In this case, heating may include leaving the liquid composition in an environment kept at about room temperature, particularly in an environment where there is no artificial heating means, for example, inside a container, in a thermostatic chamber, or on a desk, etc., and solidifying the liquid composition by drying or reaction. The liquid composition may be solidified by polymerizing the binder precursor, etc. by irradiation with electromagnetic waves such as visible light, ultraviolet light, and microwaves.

The term "coating film" refers to a liquid composition applied to the surface of a substrate or the like, regardless of whether the coating film is a sol or a gel. Solidification includes gelation of the liquid composition due to an increase in the molecular weight of the binder component contained in the liquid composition caused by polymerization of the compounds contained in the liquid composition, gelation of the liquid composition due to drying of the liquid composition caused by removal of the solvent or liquid by-products contained in the liquid composition by evaporation or the like, and solidification by a mechanism accompanying mixing of the liquid composition, or a combination of these mechanisms. Furthermore, solidification includes the reaction or drying of the liquid composition progressing to produce a solid containing organic and inorganic compounds, the removal of organic matter in the liquid composition to produce a solid that is mostly inorganic, and the production of a mixture of these solids.

The surface of the substrate 3 to which the liquid composition is applied may be subjected to various cleaning or surface treatments before application of the liquid composition. The cleaning of the surface of the substrate 3 is not limited to a specific method. The cleaning of the surface of the substrate 3 may be cleaning with an organic solvent or water, or may be acid or alkali cleaning involving immersion in an acid or alkali solution. Examples of surface treatments for the surface of the substrate 3 include mechanical treatments such as sandblasting and polishing, corona discharge treatment, flame treatment, UV- _O3 cleaning, and plasma irradiation treatment. It is expected that these cleaning or surface treatments will bring about advantages such as improved wettability of the liquid composition on the surface of the substrate 3, or the generation of hydroxyl groups that are easily bonded to compounds contained in the liquid composition.

In the manufacture of the anti-reflective film 1a, it is preferable to form a coating of the liquid composition along the surface of the substrate 3, and then allow the liquid composition to gel relatively slowly. In this case, the fluidity of the microparticles or binder precursor can be maintained to a certain degree before the liquid composition gels. For this reason, it is more preferable to dry or react the liquid composition by heating to solidify the layer constituting the anti-reflective film 1a, rather than rapidly solidifying the liquid composition by irradiating it with electromagnetic waves or the like. The heating temperature of the liquid composition is, for example, 600°C or less, preferably 400°C or less, more preferably 300°C or less, and even more preferably 250°C or less. The heating time of the liquid composition depends on the heating temperature, but is, for example, 2 hours or less, preferably 1 hour or less, more preferably 30 minutes or less, and even more preferably 15 minutes or less. Such heating conditions can be determined taking into consideration the properties required for the anti-reflective film 1a and the heat resistance temperature of the substrate 3. For example, if the liquid composition is heated to a high temperature, the resulting film will be dense and hard, but there is a trade-off in that cracks will easily occur and brittleness will become apparent.

As described above, the refractive index n _L2 of the second layer 12 is 1.30 to 1.55, and the thickness t _L2 of the second layer 12 is 25 nm or less. In addition, the refractive index n _L1 of the first layer 11 is 1.10 to 1.35, and the thickness t _L1 of the first layer 11 is 80 nm to 150 nm. The physical parameters of each layer of the antireflection film 1a may be measured or calculated as follows. The average particle diameter D _p of the hollow fine particles 21 and the thickness t _LL of the first multi-layer structure 10 consisting of the first layer 11 and the second layer 12 are measured from an SEM image or the like of the cross section of the antireflection film 1a. In addition, the reflection spectrum of the antireflection film 1a is measured with a spectrophotometer or the like. Next, using appropriate simulation software, the values of parameters corresponding to the refractive index and thickness of the first layer 11 and the second layer 12 when it is assumed that each layer is filled with a uniform medium are successively changed to calculate the reflection spectrum. Then, fitting is performed. In the fitting, the refractive index and thickness of each layer are determined so that a specific error parameter between the actual reflection spectrum measured by, for example, a spectrophotometer or the like and the calculated reflection spectrum is minimized. The main function of the antireflection film 1a is to prevent reflection on the surface of a transparent optical article or substrate. For this reason, the reflectance may be low in the actually measured reflection spectrum of the antireflection film 1a. For this reason, for example, the antireflection film 1a may be formed on the surface of a silicon wafer having a known refractive index dispersion by the same method and conditions as when the antireflection film 1a is formed on the surface of the substrate 3, and the actually measured reflection spectrum of the antireflection film 1a formed on the surface of the silicon wafer may be used for fitting. In the calculation of the reflection spectrum, it may be assumed that the thickness t _L2 of the second layer 12 is smaller than the thickness t _S of the outer shell of the hollow fine particle 21. In the calculation of the reflection spectrum, the value of the parameter corresponding to the thickness t _L2 of the second layer 12 may be uniquely determined to a specific thickness, for example, 4 nm or 2 nm, etc., determined in consideration of the amount of solid content in the liquid composition.

The specific error parameter between the measured reflectance spectrum and the calculated reflectance spectrum used for fitting is not limited to a specific parameter. Examples of the error parameter are a correlation coefficient, a root mean square value (rms value), a mean square value (MS value), and a mean absolute difference (MA value). When each parameter related to the anti-reflection film 1a is obtained, an integral value of the absolute difference at each wavelength in the measured reflectance spectrum and the calculated reflectance spectrum (IA value: Integrate of Absolute) may be used. When the measured reflectance spectrum and the calculated reflectance spectrum are obtained for each unit wavelength (for example, 1 nm), the sum of the absolute difference of the reflectance at each wavelength may be used instead of the IA value. The IA value is determined according to the following formula (1). In formula (1), r _m is the measured reflectance at a wavelength λ, and r _s is the calculated reflectance at a wavelength λ. |r _m -r _s | is the absolute value of the reflectance difference, and λ ₁ and λ ₂ indicate the integral range or the range for obtaining the sum. The sum of the absolute differences in reflectance is determined according to equation (2) below.

In the anti-reflection coating 1a, the sum of the absolute differences in the IA value or reflectance is preferably 20% or less, more preferably 18% or less, and even more preferably 15% or less. The range in which the sum of the absolute differences in the IA value or reflectance is determined may be, for example, within the range of 300 nm to 1200 nm. Taking into account the accuracy of the spectrophotometer used for the measurement, the range may be within the range of 350 nm to 900 nm, or within the range of 400 nm to 850 nm.

Anti-reflection film 1a can be modified from various viewpoints. Anti-reflection film 1a may be modified, for example, to anti-reflection film 1b shown in FIG. 3A or FIG. 3B. Anti-reflection film 1b is configured in the same manner as anti-reflection film 1a, except for the parts that will be specifically described. The same reference numerals are used to designate components of anti-reflection film 1b that are the same as or correspond to those of anti-reflection film 1a, and detailed description will be omitted. The above description of anti-reflection film 1a also applies to anti-reflection film 1b, unless there is a technical contradiction.

As shown in FIG. 3A or 3B, the antireflection film 1b further includes a third layer 13 disposed between the second layer 12 and the substrate 3 in the thickness direction of the antireflection film 1b. The third layer 13 has a refractive index n _L3 of 1.35 to 2.25 and a thickness t _M3 of 60 nm to 200 nm. With this configuration, the antireflection film 1b is likely to exhibit high antireflection performance. With the antireflection film 1b, the reflectance at a specific wavelength, for example, the design central wavelength, is likely to be low, and the low reflection band, which is a wavelength band in which the reflectance is kept below a specific value, is likely to be large. The refractive index n _L3 is a value at the D line (589.3 nm).

The refractive index n _L3 may be 1.40 to 1.85. In the antireflection film 1b, it is preferable that the condition n _L1 < n _L3 < n _L2 is satisfied. In this case, the antireflection film 1b is more likely to exhibit high antireflection performance. In the antireflection film 1b, the condition n _L1 < n _L2 ≦ n _L3 may be satisfied. The thickness t _M3 may be 70 nm to 180 nm.

In the antireflection coating 1b, the minimum value r _min(2) of the reflectance in the wavelength range of 300 nm to 1200 nm is, for example, 1% or less, more preferably 0.5% or less, and even more preferably 0.2% or less. In addition, in the reflection spectrum of the antireflection coating 1b, the wavelength range λ _range/1.0 in which the reflectance is 1% or less in the wavelength range of 300 nm to 1200 nm is, for example, 250 nm or more.

The material of the third layer 13 is not limited to a specific material as long as the third layer 13 has the above-mentioned refractive index and thickness. The third layer 13 may be a layer containing a dielectric material such as a metal oxide and a metal fluoride. The third layer 13 may be a dielectric film produced by a physical method such as vacuum deposition, sputtering, and ion plating (hereinafter referred to as "physical vapor deposition"), or may be a so-called dielectric multilayer film in which a plurality of dielectric materials are laminated. The material of the dielectric material is not limited to a specific material. Examples of the dielectric material are SiO ₂ , MgF ₂ , TiO ₂ , Ta ₂ O ₃ , AlF ₃ , CaF ₂ , Al ₂ O ₃ , ZrO ₂ , WO ₃ , CeO ₂ , ITO, ATO, and mixtures thereof. Such a dielectric layer can be produced by a known method using a physical vapor deposition method or the like.

The third layer 13 may be a layer obtained by applying a curable liquid composition along the surface of the substrate 3, drying and reacting the resulting coating to solidify it. In this case, as shown in FIG. 3B, the curable liquid composition that is the precursor of the third layer 13 may contain fine particles 33, and may contain a second binder 32 that binds the fine particles 33 together. When the third layer 13 is produced using such a curable liquid composition, an apparatus such as an evaporator required for a physical vapor deposition method is not required, and the production cost of the anti-reflection film 1b tends to be low. When the third layer 13 is produced using a curable liquid composition, as shown in FIG. 3A, the third layer 13 may not contain fine particles 33, and may contain only the second binder 32.

When the third layer 13 is produced by solidifying a curable liquid composition, the refractive index of the fine particles 33 contained in the third layer 13 is, for example, 1.25 to 2.75. The material of the fine particles 33 contained in the third layer 13 is not limited to a specific material. The fine particles 33 may be hollow or solid fine particles containing metal oxides or metal fluorides such as SiO ₂ , MgF ₂ , TiO ₂ , Ta ₂ O ₃ , AlF ₃ , CaF ₂ , Al ₂ O ₃ , ZrO ₂ , WO ₃ , CeO ₂ , indium tin oxide (ITO), and antimony tin oxide (ATO). The fine particles 33 may contain multiple types of fine particles selected from these fine particles. The fine particles 33 may be fine particles made of resin. The microparticles 33 may include, for example, solid microparticles whose main component is polymethylmethacrylate, polyethylene, polystyrene, benzoguanamine (melamine), or silicone, or may include multiple types of microparticles selected from among these.

The third layer 13 may include the following layers (i) or (ii), or (i) and (ii).
(i) a layer including a dielectric film including one or more _oxides selected from _the group consisting of _SiO2 , _MgF2 , _TiO2 , _Ta2O3 , _AlF3 , _CaF2 , _Al2O3 , _ZrO2 , _WO3 , _CeO2 , indium tin oxide, and antimony tin oxide; (ii) a layer including oxide particles composed of one or more materials selected from the group consisting of _SiO2 , _TiO2 , _ZrO2 , _CeO2 , indium tin oxide, and antimony tin oxide, and a binder for binding the oxide particles.

Since the third layer 13 is disposed closer to the substrate 3 in the thickness direction of the antireflection coating 1b than the first layer 11 and the second layer 12, it may be appropriate for the third layer 13 to have a relatively high refractive index in order to enhance the antireflection performance. In this case, for example, the fine particles 33 contained in the third layer 13 are preferably solid fine particles. In consideration of the refractive index required for the third layer 13, the fine particles 33 may contain, among metal oxides, for example, titanium oxide (TiO ₂ ; refractive index = 2.50 to 2.75; specific gravity 4.1 to 4.4), zirconium oxide (ZrO ₂ ; refractive index = 2.00 to 2.20; specific gravity 5.5), cerium oxide (CeO ₂ ; refractive index = 2.00 to 2.30; specific gravity 7.0), ATO (refractive index = 1.70 to 1.85; specific gravity 6.6), or ITO (refractive index = 1.90 to 2.20; specific gravity 7.1), or the like, and the fine particles 33 may contain silicon oxide (SiO ₂ ; refractive index = 1.41 to 1.48). When it is reasonable from the viewpoint of anti-reflection performance, the fine particles 33 may be hollow fine particles.

The average particle diameter of the fine particles 33 is not limited to a specific value. The average particle diameter is, for example, 5 nm to 200 nm. When the average particle diameter of the fine particles 33 is 5 nm or more, the manufacturing cost of the fine particles 33 is likely to be low. When the average particle diameter of the fine particles 33 is 200 nm or less, it is likely to prevent the haze of the anti-reflection film 1b from increasing due to scattering caused by the incidence of light. The average particle diameter of the fine particles 33 is preferably 10 to 100 nm, and more preferably 30 to 80 nm. The average particle diameter of the fine particles 33 contained in the third layer 13 can be measured by a method similar to the method for measuring the average particle diameter _Dp of the first hollow fine particles 21.

The content of the fine particles 33 in the solid content of the third layer 13 is not limited to a specific value. The content is, for example, 0% to 75% by mass. This makes it easier for the third layer 13 to have the desired refractive index. As described above, the third layer 13 does not need to contain fine particles. Even if the refractive index of the third layer 13 is required to be relatively high, the third layer 13 does not need to contain fine particles as long as the anti-reflection film 1b has a predetermined anti-reflection performance. In this case, the third layer 13 contains, for example, the binder 32 as a main component. In this case, it is not necessary to procure, adjust, and mix the fine particles in preparing the liquid composition that is the precursor of the third layer 13, and the manufacturing cost of the anti-reflection film 1b tends to be low.

3C and 3D are cross-sectional views showing the state of the first hollow fine particles 21 in the anti-reflective coating shown in FIG. 3A. As shown in FIG. 3C and 3D, in the anti-reflective coating 1b, a part of the first hollow fine particles 21 contained in the first layer 11 and the second layer 12 may be present at the boundary surface of the third layer 13 that is distal to the substrate 3 of the third layer 13. For example, after the formation of the third layer 13, as the coating film of the liquid composition that is the precursor of the first multi-layer structure 10 solidifies, a part of the hollow fine particles 21 contained in the first layer 11 and the second layer 12 is buried in the third layer 13, and thus a part of the first hollow fine particles 21 is present at the boundary surface of the third layer 13 that is distal to the substrate 3. In FIG. 3C, the part surrounded by the two-dot chain line shows the part of the hollow fine particles 21 buried in the third layer 13. From the viewpoint of realizing such a state in which a part of the first hollow fine particles 21 is buried in the third layer 13, it is considered that the components and composition of the third layer 13 are similar to the components and composition of the multi-layer structure 10. In particular, when the first binder 31 and the second binder 32 are similar and the precursors of the first binder 31 and the second binder 32 are also similar, the precursor of the first binder 31 and the precursor of the second binder 32 are likely to be mixed in the manufacture of the anti-reflection film 1b. For example, when pores are present in the third layer 13, the liquid composition applied to the surface of the third layer 13 distal to the substrate 3 may infiltrate the pores to fill them. As a result, the same type of compound as a part of the compound contained in the first binder 31 is also contained in the second binder 32, and the first binder 31 and the second binder 32 may become homogenous. As a result, it is considered that the surface of the third layer 13 is softened, and a part of the first hollow fine particles 21 is buried in the third layer 13 and exists at the boundary surface of the third layer 13 distal to the substrate 3. In addition, the first binder 31 and the second binder 32 being similar includes cases where the components and compositions of both are the same, as well as cases where the types of compounds contained in the binders, such as alkoxysilanes, are similar, specifically cases where the trifunctional alkoxysilanes or tetrafunctional alkoxysilanes contained in both are the same type of alkoxysilane. It is known that pores can be formed during solidification of a liquid composition containing alkoxysilane, and it is thought that a portion of the uncured liquid composition is likely to seep into such pores.

As shown in FIG. 3C, in a range having a predetermined cross-sectional area of the cross section of the anti-reflection film 1b, the first hollow fine particles 21 present at the boundary of the third layer 13 distal to the substrate 3 can be identified, and the number of the first hollow fine particles 21 can be counted. In addition, as shown in FIG. 3D, for each of the first hollow fine particles 21 present at this boundary, the proportion of the portion present on the third layer 13 side of the first hollow fine particles 21 in the whole may be obtained. A 100,000 times SEM image of the cross section of the anti-reflection film 1b is acquired, and the first layer 11, the second layer 12, and the third layer 13 are identified. Then, a target cross section of 500 nm square is specified so as to include all layers in the thickness direction. The first hollow fine particles 21 present at the boundary of the third layer 13 distal to the substrate 3 included in the target cross section are identified, and the first hollow fine particles 21 are approximated by a circle. The number N _M1 of the first hollow fine particles 21 included in the target cross section and having a portion belonging to the second layer 12 and the third layer 13, and the ratio S M /S _{L of the area S M of a partial circle (a shape with a part of a circle missing) included in the region on the third layer 13 side to the total area S L} _of _the _{approximation} circle of the first hollow fine particles 21 having a portion belonging to the second layer 12 and the third layer 13 are measured and calculated. In the anti-reflection coating 1b, the number N _M1 is, for example, 1 to 5, and preferably 3 to 5. The ratio S _M /S _L is, for example, 5% to 50%. When the first hollow fine particles 21 are present at the boundary of the third layer 13 distal to the substrate 3, the first hollow fine particles 21 are bound by both the binder of the third layer 13 and the binder of the layer in contact with the third layer 13, so that the bonding strength between the third layer 13 and the layer in contact with the boundary of the third layer 13 distal to the substrate 3 is likely to be high.

The fine particles 33 contained in the third layer 13 are not limited to specific fine particles. The fine particles 33 may be titanium oxide fine particles such as TTO-51 and TTO-55 series manufactured by Ishihara Sangyo Kaisha, JMT-150B, JMT-150AO, JMT-150ANO, and MTY-700BS manufactured by Teika Co., Ltd., STT-65C-S and STT-30EHJ manufactured by Titanium Industries Co., Ltd., and OPTOLAKE series manufactured by JGC Catalysts and Chemicals Co., Ltd. The fine particles 33 may be niobium oxide fine particles such as Nb-G6000, Nb-G6100, and Nb-G6600 manufactured by Taki Chemical Industry Co., Ltd., and niobium oxide manufactured by Mitsui Mining and Smelting Co., Ltd. The fine particles 33 may be zirconium oxide fine particles such as Zircostar manufactured by Nippon Shokubai Co., Ltd., and HXU-110JC manufactured by Sumitomo Osaka Cement Co., Ltd. The fine particles 33 may be silicon oxide fine particles such as the QSG series manufactured by Shin-Etsu Chemical Co., Ltd., the Snowtex series manufactured by Nissan Chemical Industries, Ltd., and the Sururia series manufactured by JGC Catalysts and Chemicals. The fine particles 33 may be magnesium fluoride nanoparticles manufactured by Stella Chemifa. The fine particles 33 may be aluminum oxide fine particles such as the Aluminasol 100, 200, and 500 series manufactured by Nissan Chemical Industries, Ltd., and the AS-150T and AS-1501 manufactured by Sumitomo Osaka Ceramics Co., Ltd. The fine particles 33 may be polyethylene fine particles such as polyethylene particles manufactured by Corefront Co., Ltd. and the Mipelon series manufactured by Mitsui Chemicals, Inc. The fine particles 33 may be polystyrene fine particles such as polystyrene particles manufactured by Corefront Co., Ltd. and polybeads polystyrene manufactured by Techno Chemical Co., Ltd. The fine particles 33 may be ITO fine particles such as the ITO series manufactured by Mitsubishi Materials Electronics Chemicals Co., Ltd., and P-120 and P-130 manufactured by JGC Catalysts and Chemicals Co., Ltd. The fine particles 33 may be ATO fine particles such as the T-I series manufactured by Mitsubishi Materials Electronics Chemicals Co., Ltd. As the fine particles 33, other fine particles may be added, and one type of fine particles may be used alone, or two or more types of fine particles may be mixed and used. In addition, when conductive fine particles such as ITO and ATO are used as the fine particles 33, the anti-reflection film 1b can exhibit an antistatic function. The fine particles 33 are selected and appropriately combined according to the application and function required of the anti-reflection film 1b.

When the third layer 13 is produced by solidifying a curable liquid composition, the second binder 32 contained in the third layer 13 is not limited to a specific binder. The second binder 32 may be selected taking into consideration the circumstances in the explanation of the binder given for the anti-reflection film 1a. The second binder 32 may contain at least one selected from the group consisting of alkoxysilane, hydrolysates of alkoxysilane, and polymers of hydrolysates of alkoxysilane.

The liquid composition that is the precursor of the third layer 13 may contain, in addition to the precursors of the fine particles 33 and the second binder 32, a crosslinking agent, a polymerization initiator, a leveling agent, a surfactant, a silane coupling agent, and the like, as necessary.

When the third layer 13 is produced by solidifying a curable liquid composition, it is not necessary for the third layer 13 to be formed in a state where it is separated into two layers during the process of solidifying a coating of a single type of liquid composition, as in the formation of the first multilayer structure 10 including the first layer 11 and the second layer 12. The optical parameters, such as the refractive index, may be approximately uniform throughout the entire third layer 3.

The antireflection film 1b can be produced, for example, by a method including the following steps (Ib), (IIb), and (IIIb): The antireflection film 1b includes a first layer and a second layer which are separated from each other in this order from the surface of the antireflection film 1b.
(Ib) A third layer 13 containing a dielectric material is formed on the substrate 3 .
(IIb) A first liquid composition containing first hollow fine particles 21 and at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes is applied to the surface of the third layer 13 .
(IIIb) Solidifying the first liquid composition.

In (Ib), the third layer 13 may be obtained by applying a second liquid composition containing a precursor of the second binder 32 onto the substrate 3 and solidifying the second liquid composition. In this case, the method of applying the second liquid composition onto the substrate 3 is not limited to a specific method. Examples of the method include roll coating, spray coating, spin coating, coating with a dispenser, inkjet coating, screen printing, and dip coating. In addition, for each application method, the conditions of each method can be set according to the thickness required for the second coating film.

In the manufacture of the anti-reflective film 1b, it is preferable to form a coating of the liquid composition and then allow the liquid composition to gel relatively slowly. In this case, the fluidity of the fine particles or the binder precursor can be maintained to a certain degree before the liquid composition gels. For this reason, it is more preferable to heat the layer constituting the anti-reflective film 1b to dry or react the liquid composition and solidify it. The heating temperature of the liquid composition is, for example, 600° C. or less, preferably 400° C. or less, more preferably 300° C. or less, and even more preferably 250° C. or less. The heating time of the liquid composition depends on the heating temperature, but is, for example, 2 hours or less, preferably 1 hour or less, more preferably 30 minutes or less, and even more preferably 15 minutes or less. Such heating conditions can be determined taking into consideration the properties required for the anti-reflective film 1b and the heat resistance temperature of the substrate 3. For example, if the heating temperature of the liquid composition is high, the resulting film becomes dense and hard, but there is a trade-off in that cracks are easily generated and brittleness becomes apparent.

The parameters of the anti-reflection film 1b can be calculated in the same manner as the parameters of the anti-reflection film 1a. For example, the anti-reflection film 1b is prepared on the surface of the substrate 3 or the like, and the anti-reflection film is prepared on the surface of a silicon wafer by the same method and conditions as the anti-reflection film 1b. SEM images of the cross section are obtained, the thickness of each layer is measured, the fine particles contained in each layer are identified, and the average particle size, the number N _M1 , and the ratio S _M /S _L are measured and calculated. Furthermore, the reflection spectrum of the anti-reflection film 1b is actually measured, and the reflection spectrum is calculated using the refractive index and thickness of each layer as variables, and the refractive index and thickness of each layer are specified so that the error parameter with the actually measured reflection spectrum is minimized within the allowable range. This allows the parameters of each layer of the anti-reflection film 1b to be calculated. The circumstances of the error parameters are as described for the anti-reflection film 1a.

Anti-reflection film 1a may be modified, for example, to anti-reflection film 1c shown in FIG. 4. Anti-reflection film 1c is configured in the same manner as anti-reflection film 1a, except for the parts that will be specifically described. The same reference numerals are used to designate components of anti-reflection film 1c that are the same as or correspond to those of anti-reflection film 1a, and detailed descriptions will be omitted. The above description of

anti-reflection films

1a and 1b also applies to anti-reflection film 1c, unless technically inconsistent.

As shown in FIG. 4, the antireflection film 1c further includes a third layer 13 and a fourth layer 14. The third layer 13 is disposed between the second layer 12 and the substrate 3 in the thickness direction of the antireflection film 1c. The fourth layer 14 is disposed between the third layer 13 and the substrate 3 in the thickness direction of the antireflection film 1c. The third layer 13 has a refractive index n _L3 of 1.30 to 2.25 and a thickness t _M3 of 60 nm to 200 nm. The fourth layer 14 has a refractive index n _L4 of 1.30 to 1.55 and a thickness t _M4 of 25 nm or less. The refractive indices n _L3 and n _L4 are values at the D line (589.3 nm). With this configuration, the antireflection film 1c is likely to exhibit high antireflection performance. In the antireflection film 1c, for example, the reflectance at a specific wavelength (design central wavelength) is likely to be low. The low reflection band, which is a wavelength range in which the reflectance is kept below a specific value, is likely to be large.

In the antireflection coating 1c, the minimum reflectance r _min(2) in the wavelength range of 300 nm to 1200 nm is, for example, 1% or less, preferably 0.5% or less, and more preferably 0.2% or less. In the reflection spectrum of the antireflection coating 1c in the wavelength range of 300 nm to 1200 nm, the wavelength range λ _range/1.0 in which the reflectance is 1% or less is, for example, 250 nm or more.

The refractive index n _L3 is preferably 1.40 to 2.00. The thickness t _M3 is preferably 80 nm to 160 nm. The refractive index n _L4 is preferably 1.35 to 1.50. The thickness t _M4 is preferably 20 nm or less.

For example, the antireflection film 1c may satisfy the condition n _L3 <n _L4 . This makes it easier for the antireflection film 1c to exhibit high antireflection performance. Preferably, the antireflection film 1c satisfies the conditions n _L1 <n _L2 and n _L3 <n _L4 .

As shown in FIG. 4, in the anti-reflective film 1c, the first layer 11 and the second layer 12 form a first multilayer structure 10. In addition, the third layer 13 and the fourth layer 14 form a second multilayer structure 20. The first multilayer structure 10 includes first hollow particles 21 and a first binder 31 that binds the first hollow particles 21 together. The second multilayer structure 20 includes second hollow particles 22 and a second binder 32 that binds the second hollow particles 22 together. With this configuration, the anti-reflective film 1c is more likely to exhibit high anti-reflective performance.

In the anti-reflection film 1c, the difference between the refractive index of the first binder 31 and the refractive index of the second binder 32 is not limited to a specific value. The difference is, for example, 0.01 or less. With this configuration, the anti-reflection film 1c is more likely to exhibit high anti-reflection performance.

As shown in FIG. 4, the second layer 12 includes, for example, a first portion 12a and a second portion 12b. The first portion 12a is a layered portion arranged on the first layer 11 side of the second layer 12. The second portion 12b is a layered portion arranged on the third layer 13 side of the second layer 12.

The anti-reflective film 1c can be manufactured, for example, using a liquid composition group that is a precursor of the anti-reflective film 1c. The liquid composition group includes a first liquid composition and a second liquid composition. The first liquid composition includes, for example, a precursor of the first hollow fine particles 21 and the first binder 31. The first layer 11 and the first portion 12a of the second layer 12 can be formed by solidifying the first liquid composition. The second liquid composition includes a precursor of the second hollow fine particles 22 and the second binder 32. The second portion 12b of the second layer 12, the third layer 13, and the fourth layer 14 can be formed by solidifying the second liquid composition.

The anti-reflection film 1c can be produced, for example, by a method including the following steps (Ic) and (IIc).
(Ic) The second portion 12b of the second layer 12, the third layer 13, and the fourth layer 14 are formed by at least one method selected from the group consisting of drying of a second coating film obtained by applying the above-mentioned second liquid composition along the surface of the substrate 3, and a reaction of the second coating film.
(IIc) The first portion 12a and the first layer 11 of the second layer 12 are formed by separating them, and the first portion 12a and the second portion 12b are formed by combining them together, by at least one method selected from the group consisting of drying the first coating film obtained by applying the above-mentioned first liquid composition onto the second portion 12b of the second layer 12 and reacting the first coating film.

The anti-reflection film 1c may be produced by, for example, a method including the following steps (Id), (IId), (IIId), and (IVd).
(Id) A second liquid composition containing second fine particles containing an oxide and at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes is applied onto a substrate 3 .
(IId) The second liquid composition is solidified.
(IIId) A first liquid composition containing first hollow fine particles 21 and at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes is applied to the surface of the solidified product of the second liquid composition.
(IVd) Solidifying the first liquid composition.

The anti-reflection film 1c includes, for example, a first layer 11, a second layer 12, a third layer 13, and a fourth layer 14, which are separated from each other in this order from the surface of the anti-reflection film 1c. The second layer 12 includes a part of the outer shell of the first hollow fine particle 21, a part of the polymer of the hydrolyzate of the alkoxysilane, and a part of the second fine particle.

In (Id), the mass ratio of the second microparticles to the second liquid composition is, for example, 5% to 75%. In (IIId), the mass ratio of the first hollow microparticles 21 to the first liquid composition is, for example, 80% to 99.5%.

Both the precursors of the first binder 31 and the second binder 32 may contain a predetermined alkoxysilane, and each of the first layer 11, the second layer 12, the third layer 13, and the fourth layer 14 may contain at least one of a hydrolyzate of an alkoxysilane and a polymer of a hydrolyzate of an alkoxysilane. The predetermined alkoxysilane is, for example, an alkoxysilane that is at least one precursor selected from the group consisting of a hydrolyzate of an alkoxysilane and a polymer of a hydrolyzate of an alkoxysilane, in which the difference in refractive index between the first binder 31 and the second binder 32 can be 0.01 or less. For example, in the predetermined alkoxysilane, the substance amount ratio of the trifunctional alkoxysilane to the tetrafunctional alkoxysilane is 1/4 to 4. According to this configuration, in the step (IIc), the first portion 12a and the second portion 12b are united to form a substantially identical layer, and the first layer 11, the second layer 12, the third layer 13, and the fourth layer 14 are arranged in this order toward the substrate 3.

As shown in Fig. 4, in the anti-reflection film 1c, the fourth layer 14, which is the closest to the substrate 3 among the first layer 11, the second layer 12, the third layer 13, and the fourth layer 14, contains a material that constitutes the outer shell of the hollow fine particles 22. For example, when the first binder 31 and the second binder 32 contain at least one selected from the group consisting of hydrolysates of alkoxysilanes and polymers of hydrolysates of alkoxysilanes, and the first hollow fine particles 21 and the second hollow fine particles 22 are composed of compounds mainly composed of silicon oxide, the fourth layer 14 can be filled with a compound mainly composed of silicon oxide. For example, when the outer shell of the second hollow fine particles 22 composed of a compound mainly composed of silicon oxide contains a hydrolysate of alkoxysilane or a polymer of the hydrolysate as a main component, the fourth layer 14 has almost no parts filled with air such as hollow parts and voids, and is filled with alkoxysilane, hydrolysates of alkoxysilane, and polymers of hydrolysates of alkoxysilane. Therefore, the refractive index n _L4 of the fourth layer 14 can be a value not significantly different from the refractive index of silicon oxide or a modified product thereof. The material forming the outer shell of the hollow fine particle 22 may contain a material other than silicon oxide, so long as the fourth layer 14 has a refractive index n _L4 of 1.30 to 1.55 and t _M4 is 25 nm or less.

The third layer 13 may be disposed at a position farther from the substrate 3 than the fourth layer 14. As shown in FIG. 4, the third layer 13 is a layer including the outer shell and hollow portion of the second hollow fine particle 22, and since air having a refractive index of about 1 exists in the hollow portion of the second hollow fine particle 22 and in the gap between the second hollow fine particles 22, the refractive index n _L3 of the third layer tends to be lower as the proportion of the region including such air in the third layer 13 increases. In the process in which the second liquid composition is applied before the first liquid composition is applied and the second portion 12b, the third layer 13, and the fourth layer 14 are formed, a part of the second hollow fine particle 22 may be present at the interface of the second portion 12b that is distal to the substrate 3. The second portion 12b may contain, for example, a compound constituting the outer shell of the second hollow fine particle 22 containing, for example, silicon oxide as a main component, in addition to the second binder 32, as in the fourth layer 14. When the layer constituting the anti-reflection film 1c contains alkoxysilane, hydrolyzate of alkoxysilane, or polymer of hydrolyzate of alkoxysilane, and the second hollow fine particles 22 are composed of a compound mainly composed of silicon oxide, the second portion 12b can be filled with a compound mainly composed of silicon oxide. When the hollow fine particles composed of a compound mainly composed of silicon oxide are formed of a compound mainly composed of a hydrolyzate of alkoxysilane or a polymer of hydrolyzate of alkoxysilane, the second portion 12b is unlikely to contain hollow portions and voids, and is filled with alkoxysilane, hydrolyzate of alkoxysilane, or polymer of hydrolyzate of alkoxysilane. Therefore, in the anti-reflection film 1c, the refractive index of the second portion 12b can be a value not significantly different from the refractive index of silicon oxide or modified silicon oxide.

In step (IIc), the first portion 12a and the first layer 11 of the second layer 12 are formed separately. The formation of the first layer 11 and the first portion 12a in the anti-reflective coating 1c corresponds to the formation of the first layer 11 and the second layer 12 in the anti-reflective coating 1a, respectively. Therefore, for the formation of the first layer 11 and the first portion 12a in the anti-reflective coating 1c, the explanation regarding the "second layer 12" of the anti-reflective coating 1a can be read as "first portion 12a".

In the anti-reflection film 1c, the first hollow particles 21 and the second hollow particles 22 may preferably be the same type of particles having an outer shell containing silicon oxide as a main component. The first hollow particles 21 and the second hollow particles 22 may be the same or different types of particles containing a component other than silicon oxide as a main component, so long as the refractive index and thickness of each layer are within a predetermined range. As described above, the first binder 31 and the second binder 32 are preferably selected so that the difference in refractive index between the two is 0.01 or less.

The ratio M _L of the mass of the solid content of the first hollow fine particles 21 to the mass of the solid content of the first liquid composition is greater than, for example, the ratio M _H of the mass of the solid content of the second hollow fine particles 22 to the mass of the solid content of the second liquid composition. With this configuration, the antireflection coating 1c is more likely to exhibit high antireflection performance.

In the liquid compositions which are precursors of the antireflection coating 1c, the ratios M _L and M _H preferably satisfy the condition of 0.05≦M _H /M _L ≦0.85, and more preferably satisfy the condition of 0.2≦M _H /M _L ≦0.7, so that the antireflection coating 1c can more easily exhibit high antireflection performance.

The ratio M _L is, for example, 80% to 99.5%, desirably 85% to 99.5%, more desirably 90% to 99.5%, and even more desirably 95% to 99%. M _H is, for example, 5% to 70%, desirably 10% to 50%.

The method of applying the first and second liquid compositions, which are precursors of the anti-reflective coating 1c, is not limited to a specific method. Examples of the method include roll coating, spray coating, spin coating, coating with a dispenser, inkjet coating, screen printing, and dip coating. The conditions of the application method are adjusted according to the desired thickness of the coating film.

The method of solidifying the first liquid composition and the second liquid composition is not limited to a specific method. These liquid compositions may be solidified according to a method that dries the coating by heating or polymerizes the binder precursor, etc. In this case, heating may include leaving the liquid composition in an environment kept at about room temperature, particularly in an environment where there is no artificial heating means, for example, inside a container, in a thermostatic chamber, or on a desk, etc., and solidifying the liquid composition by drying or reaction. The liquid composition may be solidified by polymerizing the binder precursor, etc. by irradiation with electromagnetic waves such as visible light, ultraviolet light, and microwaves.

The surface of the substrate 3 to which the second liquid composition is applied may be subjected to various cleaning or surface treatments before application of the second liquid composition. The cleaning of the surface of the substrate 3 is not limited to a specific method. The cleaning of the surface of the substrate 3 may be cleaning with an organic solvent or water, or may be acid or alkali cleaning accompanied by immersion in an acid or alkali solution. Examples of surface treatments for the surface of the substrate 3 include mechanical treatments such as sandblasting and polishing, corona discharge treatment, flame treatment, UV- _O3 cleaning, and plasma irradiation treatment. It is expected that these cleaning or surface treatments will bring about advantages such as improved wettability of the liquid composition on the surface of the substrate 3, or the generation of hydroxyl groups that are easily bonded to compounds contained in the liquid composition.

In the manufacture of the anti-reflective film 1c, it is preferable to form a coating of the liquid composition along the surface of the substrate 3, and then allow the liquid composition to gel relatively slowly. In this case, the fluidity of the microparticles or binder precursor can be maintained to a certain degree before the liquid composition gels. For this reason, it is more preferable to heat the layer constituting the anti-reflective film 1c to dry or react the liquid composition to solidify it. The heating temperature of the liquid composition is, for example, 600°C or less, preferably 400°C or less, more preferably 300°C or less, and even more preferably 250°C or less. The heating time of the liquid composition depends on the heating temperature, but is, for example, 2 hours or less, preferably 1 hour or less, more preferably 30 minutes or less, and even more preferably 15 minutes or less. Such heating conditions can be determined taking into consideration the properties required for the anti-reflective film 1c and the heat resistance temperature of the substrate 3. For example, if the heating temperature of the liquid composition is high, the resulting film becomes dense and hard, but there is a trade-off in that cracks are easily generated and brittleness becomes apparent.

The parameters of the anti-reflection film 1c can be calculated in the same manner as the parameters of the anti-reflection film 1a. For example, the anti-reflection film 1c is prepared on the surface of the substrate 3 or the like, and the anti-reflection film is prepared on the surface of a silicon wafer by the same method and conditions as the anti-reflection film 1c. SEM images of the cross section are obtained, the thickness of each layer is measured, the fine particles contained in each layer are identified, and the average particle size, the number N _M1 , and the ratio S _M /S _L are measured and calculated. Furthermore, the reflection spectrum of the anti-reflection film 1c is actually measured, and the reflection spectrum is calculated using the refractive index and thickness of each layer as variables, and the refractive index and thickness of each layer are specified so that the error parameter with the actually measured reflection spectrum is minimized within the allowable range. This allows the parameters of each layer of the anti-reflection film 1c to be calculated. The circumstances of the error parameters are as described for the anti-reflection film 1a.

The

anti-reflection films

1a, 1b, and 1c can be modified from various viewpoints. For example, the anti-reflection film may have k layers. In this case, the first layer 11, the second layer 12, the third layer 13, (omitted), and the kth layer may be arranged in this order toward the substrate 3. k is, for example, an integer of 5 or more.

The present invention will be explained in more detail using examples. Note that the present invention is not limited to the following examples.

<Binder Precursor A1>
44.6 g of tetraethoxysilane (TEOS) manufactured by Tokyo Chemical Industry Co., Ltd., 16.4 g of methyltriethoxysilane (MTES) manufactured by the same company, and 37.9 g of 0.3 mass % formic acid aqueous solution manufactured by Kishida Chemical Co., Ltd. were mixed and stirred to obtain binder precursor A1, which is a transparent liquid composition. The substance ratio of TEOS to MTES in binder precursor A1 was 7:3.

<Binder Precursor A2>
33.6 g of TEOS, 28.6 g of MTES, and 37.9 g of a 0.3 mass % formic acid aqueous solution manufactured by Kishida Chemical Co., Ltd. were mixed and stirred to obtain a binder precursor A2, which is a transparent liquid composition. The substance ratio of TEOS to MTES in the binder precursor A2 was 5:5.

<Binder Precursor A3>
19.0 g of TEOS, 38.0 g of MTES, and 37.9 g of a 0.3 mass % formic acid aqueous solution manufactured by Kishida Chemical Co., Ltd. were mixed and stirred to obtain a binder precursor A3, which is a transparent liquid composition. The substance ratio of TEOS to MTES in the binder precursor A3 was 3:7.

<Binder precursor A4>
5.8 g of TEOS, 45.2 g of MTES, and 37.9 g of a 0.3 mass % formic acid aqueous solution manufactured by Kishida Chemical Co., Ltd. were mixed and stirred to obtain a binder precursor A4, which is a transparent liquid composition. The substance ratio of TEOS to MTES in the binder precursor A4 was 1:9.

<Binder Precursor A5>
19.2 g of TEOS, 36.1 g of n-propyltrimethoxysilane (n-PTMS), and 37.9 g of 0.3 mass % formic acid aqueous solution manufactured by Kishida Chemical Co., Ltd. were mixed and stirred to obtain binder precursor A5, which is a transparent liquid composition. The mass ratio of TEOS to n-PTMS in binder precursor A5 was 3:7.

<Liquid composition B1>
0.14 g of binder precursor A1 and Sururia 4110 (a dispersion of approximately 20 mass% of roughly spherical hollow silica microparticles, 70 mass% of 2-propanol, and 10 mass% of methanol, with an average particle diameter (nominal) of 60 nm and a refractive index of 1.25) manufactured by JGC Catalysts and Chemicals were added to 86.0 g of a mixed liquid of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol so that the solid mass of the microparticles relative to the total solid mass was 99%, and the mixture was mixed and stirred to prepare a liquid composition B1 containing hollow microparticles and a binder precursor.

<Liquid composition B2>
To 82.3 g of a mixed solution of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol, 2.7 g of binder precursor A2 and Sururia 4110 manufactured by JGC Catalysts and Chemicals were added so that the solid content mass of the fine particles relative to the total solid content mass was 95%, and the mixture was mixed and stirred to prepare a liquid composition B2 containing hollow fine particles and a binder precursor.

<Liquid composition B3>
To 81.9 g of a mixed solution of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol, 4.4 g of binder precursor A3 and Sururia 4110 manufactured by JGC Catalysts and Chemicals were added so that the solid content mass of the fine particles relative to the total solid content mass was 90%, and the mixture was mixed and stirred to prepare a liquid composition B3 containing hollow fine particles and a binder precursor.

<Liquid composition B4>
To 81.3 g of a mixed solution of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol, 3.7 g of binder precursor A4 and Sururia 4110 manufactured by JGC Catalysts and Chemicals were added so that the solid content mass of the fine particles relative to the total solid content mass was 90%, and the mixture was mixed and stirred to prepare a liquid composition B4 containing hollow fine particles and a binder precursor.

<Liquid composition B5>
4.4 g of binder precursor A5 and Sururia 4110 manufactured by JGC Catalysts and Chemicals were added to 81.9 g of a mixed liquid of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol so that the solid mass of the fine particles relative to the total solid mass was 95%, and the mixture was mixed and stirred to prepare a liquid composition B5 containing hollow fine particles and a binder precursor.

<Liquid composition B6>
14.8 g of the binder precursor A1 was added to 82.8 g of a mixed liquid of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol, and the mixture was mixed and stirred to prepare a liquid composition B6 containing the binder precursor.

<Liquid composition B7>
To 82.8 g of a mixed solution of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol, 14.8 g of binder precursor A1 and Sururia 4110 manufactured by JGC Catalysts and Chemicals were added so that the solid mass of the fine particles relative to the total solid mass was 13.1%, and the mixture was mixed and stirred to prepare a liquid composition B7 containing fine particles and binder precursor.

<Liquid composition B8>
To 82.8 g of a mixed solution of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol, 14.8 g of binder precursor A3 and Sururia 4110 manufactured by JGC Catalysts and Chemicals were added so that the solid content mass of the fine particles relative to the total solid content mass was 10.0%, and the mixture was mixed and stirred to prepare a liquid composition B8 containing fine particles and binder precursor.

<Liquid composition B9>
To 71.4 g of a mixed liquid of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol, 15.7 g of binder precursor A1 and titanium oxide fine particles OPTOLAKE (average particle diameter 8 to 12 nm (nominal); solvent: methanol or the like) manufactured by JGC Catalysts and Chemicals were added so that the solid content mass of the fine particles relative to the total solid content mass was 54.2%, and the mixture was mixed and stirred to prepare a liquid composition B9 containing fine particles and a binder precursor.

<Liquid composition B10>
To 86.2 g of a mixed solution of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol, 0.04 g of binder precursor A1 and Sururia 4110 manufactured by JGC Catalysts and Chemicals were added so that the solid mass of the fine particles relative to the total solid mass was 99.8%, and the mixture was mixed and stirred to prepare a liquid composition B10 containing hollow fine particles and a binder precursor.

Example 1
As the substrate, a Corning borosilicate glass D263 T eco (refractive index n _D : 1.5230) having a thickness of 2.1 mm was used, and the substrate was properly washed with an alkaline solution and an organic solvent, and an appropriate amount of liquid composition B1 was dropped onto one main surface of the substrate to form a coating film by spin coating. This substrate was a square with a side length of 70 mm in plan view. Next, the substrate on which the coating film was formed was placed in a thermostatic dryer and left at 30°C for 30 minutes, and then the temperature inside the thermostatic dryer was adjusted to 200°C and the temperature was maintained at 200°C for 10 minutes. Thereafter, the temperature inside the thermostatic dryer was naturally lowered to room temperature, and the substrate provided with the low refractive index layer was taken out of the thermostatic dryer, and the anti-reflection film according to Example 1 was produced.

Example 2
As the base material, a substrate of D263 T eco (refractive index n _D : 1.5230), which is borosilicate glass manufactured by Corning Incorporated and has a thickness of 2.1 mm, was used, the substrate was properly washed with an alkaline solution and an organic solvent, and an appropriate amount of liquid composition B2 was dropped onto one main surface of the substrate, and a coating film was formed by spin coating. Next, the temperature inside the thermostatic chamber was adjusted to 200°C in advance, and the substrate on which the coating film was formed was left inside the thermostatic chamber, and after 10 minutes, the substrate was taken out of the thermostatic chamber, and the substrate was left in a room at room temperature of 25°C to cool the substrate, thereby producing an anti-reflection film according to Example 2.

Example 3
An anti-reflection film according to Example 3 was prepared in the same manner as in Example 2, except that Liquid Composition B4 was used instead of Liquid Composition B2.

Example 4
As the substrate, a Corning borosilicate glass D263 T eco (refractive index n _D : 1.5230) having a thickness of 2.1 mm was used, and the substrate was properly washed with an alkaline solution and an organic solvent, and an appropriate amount of liquid composition B6 was dropped onto one main surface of the substrate to form a coating film by spin coating. Next, the temperature inside the thermostatic chamber was adjusted to 200°C in advance, and the substrate on which the coating film was formed was left inside the thermostatic chamber, and after 10 minutes, the substrate was removed from the thermostatic chamber and left in a room at room temperature of 25°C to lower the temperature of the substrate, thereby forming the lower layer according to Example 4. Next, an appropriate amount of liquid composition B1 was dropped onto the surface of the lower layer to form a coating film by spin coating. Next, the temperature inside the thermostatic chamber was adjusted to 200°C in advance, and the substrate on which the coating film was formed was placed inside the thermostatic chamber. After 10 minutes had elapsed, the substrate was removed from the thermostatic chamber and placed in a room at room temperature of 25°C to cool the substrate, thereby producing an anti-reflection film according to Example 4.

Example 5
An anti-reflection film according to Example 5 was prepared in the same manner as in Example 4, except that Liquid Composition B8 was used instead of Liquid Composition B6, and Liquid Composition B2 was used instead of Liquid Composition B1.

Example 6
An anti-reflection film according to Example 6 was prepared in the same manner as in Example 4, except that Liquid Composition B7 was used instead of Liquid Composition B6, and Liquid Composition B5 was used instead of Liquid Composition B1.

Example 7
An anti-reflection film according to Example 7 was prepared in the same manner as in Example 4, except that Liquid Composition B9 was used instead of Liquid Composition B6.

Example 8
As the substrate, a Corning borosilicate glass D263 T eco (refractive index n _D : 1.5230) having a thickness of 2.1 mm was used, and the substrate was properly washed with an alkaline solution and an organic solvent, and a single layer of SiO ₂ was formed on one main surface of the substrate by a vacuum deposition method. The thickness of the SiO ₂ single layer was 103 nm. Next, an appropriate amount of liquid composition B3 was dropped onto the surface of the SiO ₂ single layer to form a coating film by spin coating. The temperature inside the thermostatic chamber was adjusted to 200 ° C in advance, and the substrate on which the coating film was formed was left inside the thermostatic chamber, and after 10 minutes, the substrate was removed from the thermostatic chamber, and the substrate was left in a room at room temperature of 25 ° C to cool the substrate, thereby producing an anti-reflection film according to Example 8.

<Example 9>
An anti-reflection film according to Example 9 was prepared in the same manner as in Example 4, except that Liquid Composition B8 was used instead of Liquid Composition B6, and Liquid Composition B10 was used instead of Liquid Composition B1.

Table 1 shows the conditions for the anti-reflective films in each example and the liquid compositions used to prepare these anti-reflective films.

<Anti-reflection coating for fitting>
For fitting of the reflection spectrum, a film corresponding to the antireflection film according to each example was prepared on a silicon wafer in the same manner as in each example, except that a silicon wafer was used as a base material instead of the D263 T eco substrate.

<Measurement of reflectance and reflectance spectrum>
The reflection spectrum of the antireflection coating according to each Example was measured at an incident angle of 5° using a UV-Vis-NIR spectrophotometer V-770 manufactured by JASCO Corporation. Furthermore, the reflectance at the D line (wavelength 589.6 nm) was obtained as a representative reflectance. The results are shown in Table 2. Similarly, the reflection spectrum of the film formed on the silicon wafer was also measured. The reflection spectra of the antireflection coatings according to Examples 1, 4, 5, and 7 are shown in Figures 5, 6, 7, and 8, respectively.

<Observation of the cross section of the anti-reflective coating>
The anti-reflective film according to each example was cut along a plane perpendicular to the main surface of the substrate, and the cut surface was subjected to a conductive treatment by carbon deposition to prepare a sample. The sample was observed using a field emission scanning electron microscope (FE-SEM) SU8220 manufactured by Hitachi High-Tech Corporation, and a 100,000-fold magnification SEM image of the cross section of the anti-reflective film according to each example was obtained. In the obtained 100,000-fold magnification SEM image of the cross section of the anti-reflective film according to each example, a 500 nm square region was specified so that all layers were included in the thickness direction, fine particles present in the region were specified, and the outline of each fine particle was approximated by a circle. In the circle approximating the outline of the fine particles present in the 500 nm square region, fine particles that can be recognized in more than half of the circle area were specified, and the diameter of the circle was measured, and the measured value was defined as the diameter of each fine particle diameter. The arithmetic average of the diameters of all fine particles present in the 500 nm square region was obtained, and the average particle diameter D _p of the fine particles contained in each layer of the anti-reflective film according to each example was obtained.

In addition, in each SEM image of the cross section of the antireflection coating according to Examples 4 to 9, fine particles approximated by a circle were identified in a 500 nm square region specified so as to include all layers in the thickness direction, and the number N _M1 of fine particles partly buried in the layer closer to the substrate at the boundary between layers was calculated. In addition, the area S _L of the approximate circle of the fine particles partly buried in the layer closer to the substrate at the boundary between layers and the area S _M corresponding to the partial circular portion buried in the approximate circle were calculated, and the ratio S _M /S _L was calculated.

In each of the above SEM images, an approximately straight line corresponding to the surface of the substrate was identified, and then the boundary line of each layer was identified so as to be parallel to the line, and the thickness of each layer was measured. In the SEM images of the cross sections of the antireflective coatings according to Examples 1 to 3, the thickness t _LL of the entire layer including the first layer and the second layer was measured. In the SEM images of the cross sections of the antireflective coatings according to Examples 4 and 7, the thickness t _LL of the entire layer including the first layer and the second layer and the thickness t _M3 of the third layer were measured. In the SEM images of the cross sections of the antireflective coatings according to Examples 5 and 6, the thickness t _LL of the entire layer including the first layer and the second layer and the thickness t _MM of the layer including the third layer and the fourth layer were measured. In Examples 1 to 3, the first layer and the second layer were arranged in this order toward the substrate. In Examples 4 and 7, the first layer, the second layer, and the third layer were arranged in this order toward the substrate. In Examples 5 and 6, the first layer, the second layer, the third layer, and the fourth layer were arranged in this order toward the substrate. FIG. 9 is a SEM image of a cross section of the antireflective coating according to Example 1. Fig. 10 is an SEM image of a cross section of the antireflection coating according to Example 5. In Fig. 9 and Fig. 10, the area surrounded by a white dashed line indicates a 500 nm square area selected for determining the average particle diameter _Dp , the number of fine particles _NMI , and the ratio _S / _SL .

<Reflectance spectrum fitting>
Using TFCalc (registered trademark), an optical thin film coating characteristic calculation software manufactured by HULINKS, the reflection spectrum of the film according to each embodiment formed on a silicon wafer was fitted to the reflection spectrum calculated by simulation to calculate parameters such as the refractive index and thickness of the layer included in each film according to each embodiment. The refractive index and thickness calculated in this way can be regarded as the refractive index and thickness of each layer in the anti-reflection film according to each embodiment.

The refractive index n _L1 of the first layer, the refractive index n _L2 of the second layer, the thickness t _L1 of the first layer, and the thickness t _L2 of the second layer were determined for Examples 1 to 3. It was assumed that the binder contained in the second layer was unevenly distributed on the surface between the second layer and the substrate, and it was assumed that the thickness t _L2 of the second _layer was 2 nm.

The refractive index _nL1 of the first layer, the refractive index _nL2 of the second layer, the refractive index _nL3 of the third layer, the thickness _tL1 of the first layer, the thickness _tL2 of the second layer, and the thickness _tM3 of the third layer were determined for Examples 4 and 7. It was assumed that the binder contained in the second layer was unevenly distributed on the surface between the second layer and the substrate, and it was assumed that the thickness _tL2 of the second _layer was 2 nm.

The refractive index _nL1 of the first layer, the refractive index _nL2 of the second layer, the refractive index _nL3 of the third layer, the refractive index _nL4 of the fourth layer, the thickness _tL1 of the first layer, the thickness _tL2 of the second layer, the thickness _tM3 of the third layer, and the thickness _tM4 of the fourth layer were determined for Examples 5, 6, and 9. The thickness _tL2 of the second layer was assumed to be 16 nm, which corresponds to the sum of 14 nm, which is the thickness of the outer shell of the hollow fine particles contained in the third layer, and 2 nm, which is the thickness of the binder unevenly distributed at the boundary between the first layer and the second layer.

<Adhesion test>
The adhesion test of the anti-reflective film according to the embodiment was carried out under the conditions and method (cross-cut peel test) according to Japanese Industrial Standards (JIS) K5600-5-6. Six cut lines were drawn vertically and horizontally at 1 mm intervals on the surface of the anti-reflective film according to the embodiment, forming a cut line pattern of 25 squares with a side length of 1 mm in plan view. The substrate with the anti-reflective film was placed on a flat glass table, and an adhesive tape was attached to the anti-reflective film with a surface pressure of 3.3 N/cm ² , and the adhesive tape was peeled off from the surface of the anti-reflective film over 1 second while lifting the end of the tape at an angle of 60°. The adhesive tape used was cleanroom cellophane tape CRCT-18 manufactured by Nichiban Co., Ltd. Cellophane tape is a registered trademark. The adhesive tape was attached and peeled off twice on the entire surface of the anti-reflective film on which the cut line pattern was formed. The adhesion of each anti-reflective film was evaluated according to the following evaluation criteria. The results are shown in Table 2. As shown in Table 2, the anti-reflective coatings according to Examples 1 to 8 had high adhesion to the anti-reflective coating according to Example 9.
A: Of the 25 squares, 0 were peeled off.
B: The number of peeled squares out of 25 squares is 0 or more and less than 5%.
C: The number of peeled squares out of 25 squares is 5% or more and less than 15%.
D: The number of peeled squares out of 25 squares is 15% or more and less than 35%.
E: The number of peeled squares out of 25 squares is 35% or more.

Claims

An anti-reflection film provided on a substrate,
The antireflection film includes a first layer and a second layer in this order from a front surface side of the antireflection film,
The first layer has a refractive index n L1 between 1.10 and 1.35 and a thickness between 80 nm and 150 nm;
The second layer has a refractive index n L2 of 1.30 to 1.55 and a thickness of 25 nm or less.
Anti-reflective coating.
The condition n L1 <n L2 is satisfied.
The anti-reflective coating according to claim 1 .
the anti-reflection film includes first hollow fine particles and a first binder that binds the first hollow fine particles, and a content of the first hollow fine particles in the anti-reflection film is 80% to 99.5% by mass;
The anti-reflection film according to claim 1 or 2.
The first hollow fine particles have an average particle diameter Dp of 5 nm to 200 nm.
The anti-reflective coating according to claim 3 .
The first binder includes at least one selected from the group consisting of alkoxysilane, a hydrolyzate of an alkoxysilane, and a polymer of a hydrolyzate of an alkoxysilane.
The anti-reflection film according to claim 3 or 4.
The minimum reflectance in the wavelength range of 400 nm to 800 nm is 0.5% or less.
The anti-reflection film according to any one of claims 1 to 5.
The range λ range/1.0 in which the reflectance is 1% or less in the wavelength range of 300 nm to 1200 nm is 250 nm or more.
The anti-reflection film according to any one of claims 1 to 6.
a third layer disposed between the second layer and the substrate;
The third layer has a refractive index n L3 of 1.30 to 2.25 and a thickness of 60 nm to 200 nm.
The anti-reflection film according to any one of claims 1 to 7.
The condition n L1 < n L3 < n L2 is satisfied.
The anti-reflective coating according to claim 8 .
The first layer and the second layer form a first multi-layer structure,
the first multilayer structure includes first hollow particles and a first binder that binds the first hollow particles,
The third layer includes at least a second binder.
The anti-reflection film according to claim 8 or 9.
a third layer disposed between the second layer and the substrate;
a fourth layer disposed between the third layer and the substrate,
The third layer has a refractive index n L3 of 1.30 to 2.25 and a thickness of 60 nm to 200 nm;
The fourth layer has a refractive index n L4 of 1.30 to 1.55 and a thickness of 25 nm or less;
The anti-reflection film according to any one of claims 1 to 7.
The first layer and the second layer form a first multi-layer structure,
the third layer and the fourth layer form a second multi-layer structure,
the first multilayer structure includes first hollow particles and a first binder that binds the first hollow particles,
the second multilayer structure includes second hollow particles and a second binder that binds the second hollow particles;
The anti-reflective coating according to claim 11.
The difference between the refractive index of the first binder and the refractive index of the second binder is 0.01 or less.
The anti-reflective coating according to claim 12.
A liquid composition comprising:
First hollow microparticles;
At least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes;
a mass ratio of the first hollow fine particles to a solid content of the liquid composition is 80% to 99.5%;
Liquid composition.
The alkoxysilanes include tetrafunctional alkoxysilanes and trifunctional alkoxysilanes;
the ratio of the amount of the tetrafunctional alkoxysilane to the amount of the trifunctional alkoxysilane is 1/9 to 9;
The liquid composition according to claim 14.
A liquid composition group,
a first liquid composition including a precursor of first hollow fine particles and a first binder;
a second liquid composition including a precursor of second hollow fine particles and a precursor of a second binder;
the first liquid composition is capable of forming a first layer and a first portion of a second layer by solidification of the first liquid composition;
the second liquid composition is capable of forming a second portion of the second layer, a third layer, and a fourth layer by solidification of the second liquid composition;
Liquid compositions.
The first layer has a refractive index n L1 between 1.10 and 1.35 and a thickness between 80 nm and 150 nm;
The second layer has a refractive index n L2 of 1.30 to 1.55 and a thickness of 25 nm or less;
The third layer has a refractive index n L3 of 1.30 to 2.25 and a thickness of 60 nm to 200 nm;
The fourth layer has a refractive index n L4 of 1.30 to 1.55 and a thickness of 25 nm or less;
17. The liquid compositions according to claim 16.
a ratio of the mass of the solid content of the first hollow fine particles to the mass of the solid content of the first liquid composition is greater than a ratio of the mass of the solid content of the second hollow fine particles to the mass of the solid content of the second liquid composition;
18. The liquid compositions according to claim 16 or 17.
A method for producing an anti-reflective coating, comprising the steps of:
applying a first liquid composition containing first hollow fine particles and at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes onto a substrate;
and solidifying the first liquid composition,
a mass ratio of the first hollow fine particles to the first liquid composition is 80% to 99.5%;
The antireflection film includes a first layer and a second layer separated from each other in this order from a surface of the antireflection film.
A method for manufacturing an anti-reflective coating.
The first layer has a refractive index n L1 between 1.10 and 1.35 and a thickness between 80 nm and 150 nm;
The second layer has a refractive index n L2 of 1.30 to 1.55 and a thickness of 25 nm or less;
The condition n L1 <n L2 is satisfied.
The method for producing the anti-reflection coating according to claim 19.
The antireflection film has a reflection spectrum in which the minimum reflectance in a wavelength range of 400 nm to 800 nm is 0.5% or less, and the range λ range/1.0 in which the reflectance in a wavelength range of 300 nm to 1200 nm is 1% or less is 250 nm or more.
The method for producing an anti-reflection film according to claim 19 or 20.
the second layer includes a part of the outer shell of the first hollow fine particle and a part of the polymer of the hydrolyzate of the alkoxysilane.
The method for producing the anti-reflection film according to any one of claims 19 to 21.
A method for producing an anti-reflective coating, comprising the steps of:
forming a third layer comprising a dielectric on the substrate;
applying a first liquid composition containing first hollow fine particles and at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes to a surface of the third layer;
and solidifying the first liquid composition,
the antireflection film includes a first layer and a second layer separated from each other in this order from a surface of the antireflection film,
The first layer has a refractive index n L1 between 1.10 and 1.35 and a thickness between 80 nm and 150 nm;
The second layer has a refractive index n L2 of 1.30 to 1.55 and a thickness of 25 nm or less;
The third layer has a refractive index n L3 of 1.30 to 2.25 and a thickness of 60 nm to 200 nm;
The condition n L1 <n L2 is satisfied.
A method for manufacturing an anti-reflective coating.
The third layer includes the following layers (i) and/or (ii):
The method for producing the anti-reflection coating according to claim 23.
(i) a layer including a dielectric film including one or more oxides selected from the group consisting of SiO2 , MgF2 , TiO2 , Ta2O3 , AlF3 , CaF2 , Al2O3 , ZrO2 , WO3 , CeO2 , indium tin oxide, and antimony tin oxide; (ii) a layer including oxide particles composed of one or more materials selected from the group consisting of SiO2 , TiO2 , ZrO2 , CeO2 , indium tin oxide, and antimony tin oxide, and a binder for binding the oxide particles.
A method for producing an anti-reflective coating, comprising the steps of:
applying a second liquid composition containing second fine particles containing an oxide and at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes onto a substrate;
allowing the second liquid composition to solidify; and
applying a first liquid composition containing first hollow fine particles and at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes to a surface of a solidified product of the second liquid composition;
and solidifying the first liquid composition,
the antireflection film includes a first layer, a second layer, a third layer, and a fourth layer, which are separated from each other in this order from a surface of the antireflection film,
the second layer includes a part of the outer shells of the first hollow fine particles, a part of a polymer of an alkoxysilane hydrolysate, and a part of the second fine particles.
A method for manufacturing an anti-reflective coating.
The first layer has a refractive index n L1 between 1.10 and 1.35 and a thickness between 80 nm and 150 nm;
The second layer has a refractive index n L2 of 1.30 to 1.55 and a thickness of 25 nm or less;
The third layer has a refractive index n L3 of 1.30 to 2.25 and a thickness of 60 nm to 200 nm;
The fourth layer has a refractive index n L4 of 1.30 to 1.55 and a thickness of 25 nm or less;
The conditions n L1 < n L2 and n L3 < n L4 are satisfied.
The method for producing the anti-reflection coating according to claim 25.
a mass ratio of the first hollow fine particles to the first liquid composition is 80% to 99.5%;
The mass ratio of the second fine particles to the second liquid composition is 5% to 75%.
A method for producing an anti-reflection coating according to claim 25 or 26.