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

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 nL1 of 1.10-1.35 and a thickness tL1 of 80-150 nm. The second layer 12 has a refractive index nL2 of 1.30-1.55 and a thickness tL2 of 25 nm or less.

Description

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

[0001] 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.

[0002] Conventionally, techniques for preventing or reducing light reflection from the surface of an article have been known.

[0003] For example, Patent Document 1 describes a substrate having a coating formed on its surface, the coating including predetermined hollow spherical silica-based particles and a matrix for forming a coating. These silica-based particles have pores inside their shells, and a solvent or gas is contained within the pores. Because the silica-based particles have a low refractive index, the coating also has a low refractive index, resulting in excellent anti-reflection properties.

[0004] Patent Document 2 describes an anti-reflection film having, from the lower layer side, a hard coat layer, a high refractive index layer, and a low refractive index layer 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 ZrO. The synthetic resin is a UV- or electron beam-curable synthetic resin.

[0005] Patent Document 3 describes an antireflection laminate including a coating film formed by one-coat coating 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 to middle part of the coating film, and the medium to high refractive index particles are unevenly distributed in the middle to lower part.

[0006] Japanese Patent Application Laid-Open No. 2001-233611 Japanese Patent Application Laid-Open No. 2001-350001 Japanese Patent Application Laid-Open No. 2007-272132

[0007] The techniques described in Patent Documents 1 to 3 need to be reconsidered from the viewpoint of antireflection performance. The present invention provides a novel antireflection coating that is advantageous from the viewpoint of antireflection performance.

[0008] The present invention provides an anti-reflection film provided on a substrate, the anti-reflection film comprising a first layer and a second layer in this order from the surface side of the anti-reflection film, the first layer having a refractive index n of 1.10 to 1.35. L1 and a thickness of 80 nm to 150 nm, wherein the second layer has a refractive index n of 1.30 to 1.55. L2 and an anti-reflective coating having a thickness of 25 nm or less.

[0009] The above anti-reflection film is advantageous in terms of anti-reflection performance.

[0010] FIG. 1 is a cross-sectional view showing an example of an antireflection coating according to the present invention. FIG. 2 is a side view showing an example of an optical component equipped with an antireflection coating according to the present invention. FIG. 3A is a cross-sectional view showing another example of an antireflection coating according to the present invention. FIG. 3B is a cross-sectional view showing yet another example of an antireflection coating according to the present invention. FIG. 3C is a cross-sectional view showing the state of first hollow fine particles in the antireflection coating shown in FIG. 3A. FIG. 3D is a cross-sectional view showing the state of first hollow fine particles in the antireflection coating shown in FIG. 3A. FIG. 4 is a cross-sectional view showing yet another example of an antireflection coating according to the present invention. FIG. 5 is a graph showing the reflection spectrum of the antireflection coating according to Example 1. FIG. 6 is a graph showing the reflection spectrum of the antireflection coating according to Example 4. FIG. 7 is a graph showing the reflection spectrum of the antireflection coating according to Example 5. FIG. 8 is a graph showing the reflection spectrum of the antireflection coating 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.

[0011] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the following description is for illustrative purposes only and is not intended to limit the scope of the present invention.

[0012] 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 can be provided include optical elements such as optical filters, lenses, and polarizers, various displays, eyeglasses, and transparent shields. It is conceivable to form an anti-reflection film that suppresses light reflection from the surface of an optical article by coating the 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, automobile windshields, and shields such as helmets and goggles. The anti-reflection film can suppress light reflection from the surface of such articles or substrates and increase the amount of light transmitted through such articles or substrates. Here, an anti-reflection film is composed of a single layer or multiple layers made of different materials, under different manufacturing conditions, and by different methods, and is provided on the surface of an article or substrate to prevent or reduce light reflection from the surface of the article or substrate.

[0013] For example, the reflectance of one surface of a transparent dielectric made of glass, resin, or the like is typically around 4-5%. Therefore, the overall reflectance, taking into account reflections on both the front and back surfaces, can be 8-10% for a single plate-shaped transparent dielectric. For example, imaging devices such as cameras typically include an optical system containing multiple lenses made of transparent dielectrics such as glass and resin. The amount of reflection from the lens surfaces in the optical system is very large, significantly reducing the amount of light reaching the light-receiving surface of an imaging element such as a CCD or CMOS. Furthermore, reflected light from the surface of these lenses made of transparent dielectrics 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, potentially causing undesirable phenomena such as ghosting or flare. Therefore, it is important to form an anti-reflective coating on the surface of an article or substrate that performs functions such as light transmission or refraction to suppress reflections on the surface.

[0014] As shown in FIG. 1, the anti-reflection film 1a is a film provided on a substrate 3. The anti-reflection film 1a comprises, in order from its surface side, a first layer 11 and a second layer 12. The substrate 3 may be an article for transmitting and utilizing light in a desired wavelength range. 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 of 1.10 to 1.35. L1 and a thickness t of 80 nm to 150 nm L1 The second layer 12 has a refractive index n L2 and a thickness t of 25 nm or less L2 With this configuration, the anti-reflection film 1a can exhibit high anti-reflection performance. L1 and refractive index n L2 is the refractive index at the D line (wavelength 589.3 nm).

[0015] In the anti-reflection coating 1a, for example, in a reflection spectrum showing the wavelength when light having a wavelength of 300 nm to 1200 nm is incident at an incident angle of 5° and the reflectance for that wavelength, the minimum reflectance r min 300-1200 can be less than 1%. min 300-1200 is preferably 0.5% or less, and more preferably 0.2% or less. Unless otherwise specified, the reflectance of an anti-reflection film 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°.

[0016] In the anti-reflection film 1a, the minimum reflectance r in the wavelength range of 400 nm to 800 nm min 400-800 is not limited to a specific value. min 400-800 is, for example, 0.5% or less. In this case, the anti-reflection film 1a is more likely to exhibit high anti-reflection performance. min 400-800 is preferably 0.2% or less.

[0017] In the anti-reflection film 1a, the range λ where the reflectance is 2.5% or less in the wavelength range of 300 nm to 1200 nm range / 2.5 is not limited to a specific value. range / 2.5 is, for example, 400 nm or more. This allows the anti-reflection film 1a to more easily exhibit high anti-reflection performance. range / 2.5 The wavelength may be 450 nm or more, or 500 nm or more. Hereinafter, unless otherwise specified, the wavelength and wavelength range corresponding to a predetermined reflectance also refer to the wavelength determined from the reflectance spectrum.

[0018] In the anti-reflection film 1a, the range λ in which the reflectance is 1.0% or less in the wavelength range of 300 nm to 1200 nm range / 1.0 is not limited to a specific value. range / 1.0 is, for example, 250 nm or more. This allows the anti-reflection film 1a to more easily exhibit high anti-reflection performance. range / 1.0 may be 300 nm or more, 350 nm or more, or 400 nm or more.

[0019] 1 , in the antireflection coating 1a, the second layer 12 is formed, for example, in direct contact with the surface of the substrate 3. Another layer or film may be disposed between the second layer 12 and the surface of the substrate 3 in the thickness direction of the antireflection coating 1a.

[0020] In the anti-reflection film 1a, for example, n L1 <n L2 In this case, the antireflection film 1a is more likely to exhibit high antireflection performance.

[0021] Second layer thickness t L2 is preferably 15 nm or less, more preferably 10 nm or less, and even more preferably 5 nm or less. This allows the antireflection film 1a to more easily exhibit high antireflection performance.

[0022] As shown in FIG. 1, in the anti-reflection coating 1a, the first layer 11 and the second layer 12 form a first multi-layer structure 10. The thickness t LLis, for example, 100 nm to 160 nm. In this case, the anti-reflection film 1a is more likely to exhibit high anti-reflection performance. D : 589.3 nm) LD and thickness t LL Gat LL = λ D / (4n LD ) the reflectance at the D line is minimized when the thickness t LL It is advantageous from the viewpoint of high anti-reflection performance that the thickness is 100 nm to 160 nm.

[0023] In the anti-reflection film 1a, the thickness t LL and any wavelength λ X [nm] is, for example, λ X / 6≦t LL ≦λ X In this case, the anti-reflection coating 1a may satisfy the condition of wavelength λ X In addition, the wavelength range in the reflection spectrum where the reflectance is equal to or less than a predetermined value can be widened, which is advantageous. 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), or may be 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.

[0024] Refractive index n of the substrate sb When the refractive index of the anti-reflection film is n1, it is possible to adjust the optical thickness of the anti-reflection film to 1 / 4 of the predetermined wavelength λ. sb -n1 2 The smaller the absolute value of the value, the smaller the reflectance at the wavelength λ corresponding to that refractive index. Therefore, it may be desirable from the viewpoint of reducing 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.

[0025] As shown in FIG. 1 , the first multilayer structure 10 includes, for example, first hollow particles 21 and a first binder 31. The first binder 31 binds the first hollow particles 21. With this configuration, the first layer 11 and the second layer 12 are likely to have the desired refractive index and thickness, and the anti-reflection coating 1a is more likely to exhibit high anti-reflection performance. In addition, as will be described later, the inclusion of the first hollow particles 21 in the first multilayer structure 10 not only reduces the effective refractive index of the anti-reflection coating 1a, but is also expected to improve mechanical strength such as peel resistance and abrasion resistance, as well as weather resistance such as moisture resistance. In this specification, "fine particles" refers to particles having an average particle diameter of less than 1 μm.

[0026] Even if the material forming the outer shell of the first hollow particles 21 has a predetermined refractive index, the hollow portions 21a inside the particles can be considered to be filled with air. Therefore, 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. 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 portions 21a. The refractive index of a specific wavelength of the first hollow microparticle may be widely known, or it may be determined by, for example, an effective medium approximation method using the Bruggemann equation, 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.

[0027] The material forming the outer shell of the first hollow microparticles 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 microparticles 21 are silicon oxide (silica) and magnesium fluoride. Examples of organic materials forming the outer shell of the first hollow microparticles 21 are polystyrene and polyethylene. These materials may be used alone or two or more materials may be mixed and used. From the viewpoint of ease of manufacturing the hollow microparticles, the main component of the outer shell of the first hollow microparticles 21 is preferably silicon oxide. In this specification, the main component is the component that is contained in the largest amount by mass.

[0028] The shape of the first hollow fine particles 21 is not limited to a specific shape. The first hollow fine particles 21 may be substantially spherical, may have an irregular shape, or may have a specific shape linked in a chain shape.

[0029] Average particle diameter D of the first hollow fine particles 21 p is not limited to a specific value. p is, for example, 5 to 200 nm. p When the average particle diameter D is 5 nm or more, the manufacturing cost of the first hollow fine particles 21 tends 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 portions 21a. pBy having a diameter of 200 nm or less, scattering of light incident on the first hollow fine particles 21 is suppressed, and the haze of the anti-reflection coating 1a is likely to be prevented from increasing. The size and shape of the fine particles can be confirmed and measured, for example, by observation using a scanning electron microscope (SEM). The average particle diameter of the fine particles can be determined by acquiring a 100,000x magnification SEM image of a cross section perpendicular to the main surface of an article or the like on which a film containing the fine particles is formed, identifying the fine particles, approximating the shape of the fine particles to a circle, measuring their diameter, and then using the arithmetic mean value of the diameters of the fine particles contained in a predetermined area, for example, a 500 nm square area including all layers constituting the anti-reflection coating. This method is convenient when determining the average particle diameter of 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 including the area of ​​each fine particle may be identified as the approximate circle.

[0030] Average particle diameter D p is preferably 10 to 100 nm, more preferably 30 to 80 nm.

[0031] The outer shell of the first hollow fine particle 21 may be crystalline, polycrystalline, or amorphous.

[0032] Thickness t of the outer shell of the first hollow fine particle 21 S is not limited to a specific value. S is, for example, 1 to 50 nm. S When the thickness t 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. S When the thickness t of the outer shell of the hollow fine particle is 50 nm or less, the first hollow fine particle 21 can be easily produced. S 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 the effective medium approximation method using the Bruggemann equation.

[0033] The first hollow fine particles 21 have an average particle diameter D p The thickness of the outer shell t S The ratio t S / D pis not limited to a specific value. S / D p is, for example, 1 / 50 to 1 / 5.

[0034] The first hollow microparticles 21 may be hollow microparticles whose surfaces have been modified. For example, microparticles may be used that have been pre-reacted 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 a reactive functional group such as an amino group, an epoxy group, a methacrylic group, or a vinyl group. Furthermore, compounds known as coupling agents may be used as such compounds. Coupling agents include, for example, components such as Si, Ti, or Al. In this specification, Si is considered to be a metal component.

[0035] In manufacturing the anti-reflection coating 1a, the particles for the first hollow particles 21 may be provided as a powder or as a particle dispersion. The particle dispersion may be in a colloidal state. For example, colloidal silica, which is a colloidal dispersion of silicon oxide particles, may be used. The use of a particle dispersion stably maintains the dispersion state of the particles, tends to reduce the haze of the anti-reflection coating 1a, and tends to result in high transparency. The dispersion medium for the dispersion may be alcohols, ketones, esters, ethers, aromatic hydrocarbons, or amides. Examples of alcohols include methanol, ethanol, isopropanol, butanol, and octanol. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of esters include ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. Examples of ethers include ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, and diethylene glycol monobutyl ether. Examples of aromatic hydrocarbons include benzene, toluene, and xylene. Examples of amides include dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Among these, methanol, isopropanol, butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, propylene glycol monomethyl ether, toluene, and xylene are preferred as dispersion media.

[0036] The first hollow fine particles 21 may be Suluria 1110 (silicon oxide, nominal average particle diameter of approximately 50 nm, solid content of approximately 20% by mass) manufactured by JGC Catalysts and Chemicals Co., Ltd., or Suluria 4110 (silicon oxide, nominal average particle diameter: 50 nm to 60 nm, solid content of approximately 20 to 25% by mass) manufactured by the same company. These are hollow fine particles whose outer shell is mainly composed of silicon oxide.

[0037] The anti-reflection coating 1a contains a binder such as a first binder 31. The binder binds the fine particles contained in the anti-reflection coating 1a to each other and to the substrate or underlayer, etc. A binder is essentially a material for binding materials such as particles, pigments, and substrates within a layer. However, in this specification, a component that solidifies to form a uniform structure within a layer that does not contain pigments or particles, etc., is also considered to be a binder.

[0038] The binder material contained in the anti-reflection 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 is cured by heating or irradiation with electromagnetic waves such as light. When the binder precursor is liquid, the precursor of the anti-reflection film 1a can be easily prepared in the production thereof, and the addition, dispersion, colloidalization, or dissolution of fine particles can be easily performed.

[0039] The binder precursor may be, for example, a monomer or oligomer having a polymerizable unsaturated group, such as an acrylic group, a vinyl group, or an allyl group, in the molecule. 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 binder precursors include 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 also be a compound obtained by the addition reaction of a glycidyl group-containing compound, such as alkyl glycidyl ether, allyl glycidyl ether, or glycidyl (meth)acrylate, with (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.

[0040] 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. x and R y is a functional group containing at least a carbon atom, M is a metal atom, and n and m represent the number of functional groups substantially contained in one molecule. x m M (OR y ) n Formula (A)

[0041] The metal component is selected from the group consisting of, for example, Si, Ti, Nb, Zr, and Al. The binder precursor may preferably 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. R1 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. 1 4-n Si(OR 2 ) n Formula (B)

[0042] Such alkoxysilanes undergo hydrolysis in the presence of water, generating silanol groups (-Si-OH), which then undergo condensation polymerization to generate siloxane bonds (-O-Si-O-) between multiple molecules. This increases the molecular weight, producing a polymer, making it relatively easy to obtain binders containing silica or silsesquioxane. Silica is produced by the reaction of a tetrafunctional alkoxysilane in which n = 4 in formula (B). Silsesquioxane is produced by the reaction of a trifunctional alkoxysilane in which n = 3 in formula (B).

[0043] Silica is the main component of glass. Ordinary glass requires a process of melting silica sand at very high temperatures. However, solidification of a silica-containing composition using alkoxysilane is advantageous in that it can be achieved at low temperatures. Additionally, binders that use alkoxysilane as part of their raw materials can contain silica, etc., which is advantageous from the standpoint of durability. Furthermore, binders that use alkoxysilane as part of their raw materials are likely to have desired properties, such as affinity with the particles or the formation of hydrogen bonds with the particles, even when containing particles whose main component is silicon oxide, such as silica, and are expected to increase the binding strength of the particles. Additionally, the difference in refractive index between the binder and the particles is likely to be small, which tends to increase the transparency of a layer or film containing the binder and the particles.

[0044] The alkoxysilane contained in the binder precursor is not limited to a specific alkoxysilane. Examples of the alkoxysilane 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, and methyltriethoxysilane. 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 propyloxy)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,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 binder precursor may be a hydrolyzate of these alkoxysilanes having silanol groups, orThe binder or binder precursor may contain a plurality of alkoxysilanes, a hydrolyzate of a plurality of alkoxysilanes, or a polymer of a hydrolyzate of a plurality of alkoxysilanes.

[0045] The alkoxysilane contained in the binder precursor may have, in addition to the alkoxy group, a reactive functional group or a polymerizable unsaturated group such as an acryloyl group or an epoxy group in one molecule. Examples of such alkoxysilanes include 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-methacryloxypropyl Tris(trifluoroacetoxy)silane, 3-glycidoxypropyltriacetoxysilane, 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.

[0046] The first binder 31 contains, for example, at least one selected from the group consisting of alkoxysilane, a hydrolyzate of alkoxysilane, and a polymer of a hydrolyzate of alkoxysilane, which makes it easier for the antireflection coating 1a to exhibit high antireflection performance.

[0047] The second layer 12 includes, for example, the first binder 31 present near the surface of the substrate 3 and a portion of the outer shell of the first hollow fine particles 21 present near the surface of the substrate 3. Some of the first hollow fine particles 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 substantially filled with solid matter and contains almost no hollow or void spaces where air is present. For example, if the main component of the outer shell of the first hollow fine particles 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 primarily composed of silicon oxide. In this case, the refractive index of the second layer 12 is close to that of silicon oxide or a modified silicon oxide. Meanwhile, the first layer 11 includes the outer shell of the first hollow fine particles 21, the hollow portions 21a of the first hollow fine particles 21, and the voids between the first hollow fine particles 21. Thus, air with a refractive index of approximately 1 is present in the first layer 11. Therefore, the first layer 11 and the second layer 12 are likely to have the desired refractive index and thickness, and n L1 <n L2 The larger the volume of air in the first layer 11, the higher the refractive index n L1 tends to be small, and n L1 <n L2 The conditions are easy to meet.

[0048] The thickness of the second layer 12 is, for example, equal to or larger than the average particle diameter D of the first hollow fine particles 21. p Furthermore, the thickness of the second layer 12 is smaller than the thickness t S It may be smaller.

[0049] The substrate 3 is not limited to a specific substrate as long as it has an anti-reflection coating 1a formed on its surface. The optical properties of the anti-reflection coating 1a may be determined in consideration of 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 also 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 functions such as 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, which allows it to diffract light and perform a predetermined function.

[0050] 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.

[0051] Fig. 2 is a side view showing an example of an optical component including a substrate 3 and an anti-reflection coating 1a. As shown in Fig. 2, the substrate 3 may be a lens such as a convex lens.

[0052] 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 include 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 a sol-gel method. In this case, it is easy to form a structure of the wavelength size of light. The raw materials of the glass used in the sol-gel method are metals and compounds having alkoxy groups.

[0053] The resin contained in the base material 3 is not limited to a specific resin. Examples of the resin include acrylic (methacrylic) resin, styrene resin, polycarbonate resin, polyolefin resin, epoxy resin, polyethylene resin, polypropylene resin, ABS resin, polyamide resin, polyacetal resin, and polyethylene terephthalate resin.

[0054] The refractive index n of the substrate 3 at the D line SB is, for example, 1.20 to 2.50, may be 1.30 to 2.30, or may be 1.35 to 2.00.

[0055] The anti-reflection coating 1a or a layer included in the anti-reflection coating 1a can be produced, for example, by solidifying a predetermined liquid composition.

[0056] The liquid composition contains a binder precursor and, if necessary, fine particles. The liquid composition may further contain an organic polymer. Examples of the organic polymer may be polyethers such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, or may be a polyisocyanate compound. This allows the organic polymer to act as a crosslinking agent when the liquid composition is cured, thereby improving the mechanical properties, such as hardness and scratch resistance, light resistance, and weather resistance, of the anti-reflection coating 1a.

[0057] 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.

[0058] When the binder precursor partially contains an alkoxysilane or its hydrolyzate, the liquid composition may contain water to promote hydrolysis, and an acid (acid catalyst) or alkali (alkali catalyst) that acts as a catalyst. Examples of acids (acid catalysts) include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, formic acid, and acetic acid. Examples of alkali catalysts include 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 characterized by being substantially halogen-free, having a small acid dissociation constant (pKa) (pKa = 3.7 (formic acid), 4.7 (acetic acid)), and being strong acids, making them desirable as acid catalysts. 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 a polysilane structure can be formed without hydrolysis. From this perspective, the use of formic acid and acetic acid is also desirable. In addition, since formic acid has a fairly simple structure among organic acids, it is easy for it to exhibit the desired properties as an acid catalyst.

[0059] The liquid composition may be prepared, for example, by adding the catalyst dropwise to a liquid containing an alkoxysilane while stirring the liquid, which prevents the reaction caused by the catalyst from proceeding too quickly due to the addition of a large amount of catalyst compound at once, and thus reduces the likelihood of the reaction being biased.

[0060] The liquid composition may contain a solvent. The solvent also contributes to the dispersion of, for example, fine particles, etc., making it easier for the liquid composition to have the desired viscosity during the manufacturing process of the anti-reflection coating 1a. In addition, the coating operation of the liquid composition or the quality of the coating film can be easily adjusted to the desired level. Metal alkoxide compounds such as alkoxysilanes, which are raw materials for the binder 31, may be poorly soluble in the 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 include methanol, ethanol, isopropanol, butanol, octanol, 1-methoxy-2-propanol, and 3-methoxy-3-methyl-1-butanol. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of esters include ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. Examples of ethers include ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, and diethylene glycol monobutyl ether. Examples of aromatic hydrocarbons include benzene, toluene, and xylene. Examples of amides include dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Organic acids such as acetic acid and formic acid may also be used as solvents in preparing 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 is preferably used as the solvent. These solvents may be used alone, or two or more of them may be mixed and used.

[0061] The liquid composition may contain a compound having both hydrophilic and hydrophobic properties, such as a surfactant and a silane coupling agent, for the purpose of preventing aggregation of the fine particles.

[0062] The liquid composition can be prepared by selecting the types of microparticles, binder precursors, solvents, catalysts, and the above-mentioned compounds, adjusting the composition ratio of each component using known methods and conditions, and mixing them while causing a reaction of some of the compounds as necessary.

[0063] In the liquid composition that serves as the precursor for the first multilayer structure 10 of the antireflective coating 1a, the ratio of the mass of the solid content of the first hollow particles 21 to the mass of the solid content of the liquid composition is not limited to a specific value. This ratio is, for example, 80% to 99.5%. This configuration facilitates the first layer 11 and the second layer 12 to have the desired refractive index and thickness. The precursor of the first binder 31 in the liquid composition may function, for example, to bind the first hollow particles 21 together or to the surface of the substrate 3. Any amount of the precursor of the first binder 31 present in excess of the amount necessary for binding the first hollow particles may migrate toward the surface of the substrate 3 during the production of the antireflective coating 1a, solidify, and form part of the second layer 12. As described above, the second layer 12 is filled with a solid containing a portion of the outer shells of the hollow particles 21 and the first binder 31, and is a layer in the first multilayer structure 10 that has a relatively high refractive index. The first binder 31 includes, for example, a hydrolyzate of an alkoxysilane or a polymer thereof.

[0064] 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.

[0065] 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 alkoxysilane hydrolysates. In this case, the alkoxysilanes include tetrafunctional alkoxysilanes and trifunctional alkoxysilanes, and the ratio of the amount of substance of the tetrafunctional alkoxysilane to the amount of substance of the 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 are likely to have the desired refractive index and thickness. In addition, the first multi-layer structure 10 is likely to have the desired mechanical strength and high transparency.

[0066] The antireflective coating 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 then solidifying the liquid composition. The mass ratio of the first hollow fine particles 21 to the liquid composition is 80% to 99.5%. The antireflective coating 1a contains a first layer 11 and a second layer 12, which are separated from each other. According to this method, the antireflective coating 1a having the first layer 11 and the second layer 12 can be produced relatively easily using a single liquid composition.

[0067] The method for applying the liquid composition, which is a precursor of the anti-reflection coating 1a, along the substrate 3 is not limited to a specific method. Examples of such methods 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 depending on the required thickness of the coating film. For example, in the case of dip coating, 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 of the first multi-layer structure 10, LL is 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 spin coating, when the rotation angular velocity is ω [radian / second], the thickness of the coating film is proportional to η 1 / 3 / ω 2 / 3is proportional to.

[0068] The method for solidifying the liquid composition is not limited to a specific method. The solidification of the liquid composition may be carried out according to a method that dries the coating film by heating or polymerizes the binder precursor or the like. In this case, heating may be carried out in an environment maintained at about room temperature, particularly in an environment without artificial heating means, such as in a container, a thermostatic chamber, or on a desk, where the liquid composition is left to dry or react and solidify. The solidification of the liquid composition may be carried out by irradiating it with electromagnetic waves such as visible light, ultraviolet light, or microwaves to polymerize the binder precursor or the like.

[0069] A 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; solidification due to a mechanism associated with mixing of the liquid composition; or a combination of these mechanisms. Furthermore, solidification includes the generation of a solid containing organic and inorganic compounds as a result of reaction or drying of the liquid composition; the removal of organic matter from the liquid composition to obtain a substantially inorganic solid; and the generation of a mixture of these solids.

[0070] The surface of the substrate 3 to which the liquid composition is to be applied may be subjected to various cleaning or surface treatments before application of the liquid composition. The cleaning method for 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 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. These cleaning or surface treatments are expected to provide advantages such as improving the wettability of the liquid composition on the surface of the substrate 3 or generating hydroxyl groups that easily bond with compounds contained in the liquid composition.

[0071] In the manufacture of the antireflective coating 1a, preferably, after forming a coating of the liquid composition along the surface of the substrate 3, the liquid composition may be allowed to gel relatively slowly. In this case, the fluidity of the microparticles or binder precursors can be maintained to a certain extent before the liquid composition gels. For this reason, it is more desirable to solidify the layer constituting the antireflective coating 1a by drying or reacting the liquid composition with heat 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 account the properties required of the antireflective coating 1a and the heat resistance temperature of the substrate 3. For example, if the heating temperature of the liquid composition is high, 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.

[0072] As described above, the refractive index n of the second layer 12 L2 is 1.30 to 1.55, and the thickness t L2 In addition, the refractive index n L1 is 1.10 to 1.35, and the thickness t L1 The physical parameters of each layer of the antireflection coating 1a may be measured or calculated as follows: The average particle diameter D of the hollow fine particles 21 is measured or calculated from an SEM image of the cross section of the antireflection coating 1a. p and the thickness t of the first multi-layer structure 10 consisting of the first layer 11 and the second layer 12. LL, is measured. In addition, the reflection spectrum of the antireflection coating 1a is measured using 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 are successively changed, assuming that each layer is filled with a uniform medium, to calculate the reflection spectrum. Then, fitting is performed. In fitting, for example, the refractive index and thickness of each layer are determined so that a specific error parameter between the actual reflection spectrum measured using a spectrophotometer or the like and the calculated reflection spectrum is minimized. The main function of the antireflection coating 1a is to prevent reflection on the surface of a transparent optical article or substrate. Therefore, the reflectance may be low in the actually measured reflection spectrum of the antireflection coating 1a. For this reason, for example, the antireflection coating 1a may be formed on the surface of a silicon wafer with a known refractive index dispersion using the same method and conditions as when formed on the surface of the substrate 3, and the actually measured reflection spectrum of the antireflection coating 1a formed on the surface of the silicon wafer may be used for fitting. In calculating the reflection spectrum, the thickness t of the second layer 12 may be determined so that a specific error parameter between the actual reflection spectrum measured using a spectrophotometer or the like and the calculated reflection spectrum is minimized. L2 is the thickness t of the outer shell of the hollow fine particle 21 S In calculating the reflectance spectrum, the thickness t of the second layer 12 may be assumed to be smaller than L2 The value of the parameter corresponding to may be uniquely determined to a specific thickness, such as 4 nm or 2 nm, determined in consideration of the amount of solid content in the liquid composition.

[0073] 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 include a correlation coefficient, a root mean square (rms value), a mean square (MS value), and a mean absolute difference (MA value). When determining each parameter related to the anti-reflection coating 1a, the integral of the absolute difference at each wavelength between 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 determined for each unit wavelength (e.g., 1 nm), the sum of the absolute differences 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 wavelength λ, and r s is the calculated reflectance at wavelength λ. m -r s is the absolute value of the reflectance difference, and λ1 and λ2 indicate the integration range or the range over which the sum is calculated. The sum of the absolute reflectance differences is determined according to the following formula (2):

[0074]

[0075]

[0076] In the antireflection 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 can be 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 400 nm to 850 nm.

[0077] The anti-reflection coating 1a can be modified from various viewpoints. For example, the anti-reflection coating 1a may be modified to the anti-reflection coating 1b shown in FIG. 3A or 3B. The anti-reflection coating 1b has the same configuration as the anti-reflection coating 1a, except for portions that will be particularly described. The same reference numerals are used to designate components of the anti-reflection coating 1b that are the same as or correspond to those of the anti-reflection coating 1a, and detailed description thereof will be omitted. The above description of the anti-reflection coating 1a also applies to the anti-reflection coating 1b, unless technically inconsistent.

[0078] 3A or 3B, the anti-reflection coating 1b further includes a third layer 13 disposed between the second layer 12 and the substrate 3 in the thickness direction of the anti-reflection coating 1b. The third layer 13 has a refractive index n of 1.35 to 2.25. L3 and a thickness t of 60 nm to 200 nm M3 With this configuration, the anti-reflection film 1b is likely to exhibit high anti-reflection performance. The anti-reflection film 1b is likely to have low reflectance at a specific wavelength, for example, at the design central wavelength, and is likely to have a large low-reflection band, which is a wavelength band in which the reflectance is kept below a specific value. L3 is the value at the D line (589.3 nm).

[0079] Refractive index n L3 In the anti-reflection film 1b, n L1 <n L3 <n L2 In this case, the anti-reflection film 1b is more likely to exhibit high anti-reflection performance. L1 <n L2 ≦n L3 The thickness t M3 may be between 70 nm and 180 nm.

[0080] In the anti-reflection film 1b, the minimum value r of the reflectance in the wavelength range of 300 nm to 1200 nm min(2) 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 film 1b, the wavelength range λ where the reflectance is 1% or less at wavelengths of 300 nm to 1200 nm isrange / 1.0 is, for example, 250 nm or more.

[0081] The material of the third layer 13 is not limited to a specific material as long as the third layer 13 has the above-described refractive index and thickness. The third layer 13 may be a layer containing a dielectric material such as a metal oxide or a metal fluoride. The third layer 13 may be a dielectric film fabricated by a physical method such as vacuum deposition, sputtering, or ion plating (hereinafter referred to as "physical vapor deposition"), or a so-called dielectric multilayer film in which multiple dielectric layers are stacked. The dielectric material is not limited to a specific material. Examples of dielectric materials include SiO2, MgF2, TiO2, Ta2O3, AlF3, CaF2, Al2O3, ZrO2, WO3, CeO2, ITO, ATO, and mixtures thereof. Such a dielectric layer can be fabricated by a known method such as physical vapor deposition.

[0082] 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, and solidifying it. In this case, as shown in FIG. 3B , the curable liquid composition that serves as the precursor of the third layer 13 may contain fine particles 33 and may also 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, equipment such as an evaporator required for physical vapor deposition methods is not required, which tends to reduce the production cost of the anti-reflection coating 1b. When the third layer 13 is produced using a curable liquid composition, the third layer 13 may contain only the second binder 32 without containing the fine particles 33, as shown in FIG. 3A .

[0083] When the third layer 13 is formed by solidifying a curable liquid composition, the refractive index of the microparticles 33 contained in the third layer 13 is, for example, 1.25 to 2.75. The material of the microparticles 33 contained in the third layer 13 is not limited to a specific material. The microparticles 33 may be hollow or solid microparticles containing metal oxides or metal fluorides such as SiO2, MgF2, TiO2, Ta2O3, AlF3, CaF2, Al2O3, ZrO2, WO3, CeO2, indium tin oxide (ITO), and antimony tin oxide (ATO). The microparticles 33 may contain multiple types of microparticles selected from these microparticles. The microparticles 33 may also be resin microparticles. The microparticles 33 may include solid microparticles whose main component is, for example, polymethyl methacrylate, polyethylene, polystyrene, benzoguanamine (melamine), or silicone, or may contain multiple types of microparticles selected from these.

[0084] The third layer 13 may include the following layers (i) or (ii), or (i) and (ii): (i) a layer including a dielectric film containing 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, or (ii) a layer including oxide fine 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 fine particles.

[0085] 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 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 include, among metal oxides, titanium oxide (TiO2; refractive index = 2.50 to 2.75; specific gravity 4.1 to 4.4), zirconium oxide (ZrO2; refractive index = 2.00 to 2.20; specific gravity 5.5), cerium oxide (CeO2; 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 fine particles 33 may include silicon oxide (SiO2; refractive index = 1.41 to 1.48). If it is reasonable from the viewpoint of anti-reflection performance, the fine particles 33 may be hollow fine particles.

[0086] 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 tends to be low. When the average particle diameter of the fine particles 33 is 200 nm or less, it tends to be possible to prevent the haze of the anti-reflection film 1b from increasing due to scattering caused by incident 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 is set to be equal to or smaller than the average particle diameter D of the first hollow fine particles 21. p It can be measured in the same way as the measurement method of .

[0087] 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 a desired refractive index. As described above, the third layer 13 does not need to contain fine particles. Even when 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 antireflection coating 1b has a predetermined antireflection performance. In this case, the third layer 13 contains, for example, a binder 32 as a main component. In this case, there is no need to procure, adjust, and mix fine particles in preparing the liquid composition that is the precursor of the third layer 13, which tends to reduce the manufacturing cost of the antireflection coating 1b.

[0088] 3C and 3D are cross-sectional views showing the state of the first hollow fine particles 21 in the anti-reflection coating shown in FIG. 3A. As shown in FIGS. 3C and 3D, in the anti-reflection coating 1b, some of the first hollow fine particles 21 contained in the first layer 11 and the second layer 12 may be present at the interface between the third layer 13 and the substrate 3 of the third layer 13. For example, after the formation of the third layer 13, as the coating of the liquid composition that is the precursor of the first multi-layer structure 10 solidifies, some of the hollow fine particles 21 contained in the first layer 11 and the second layer 12 are buried in the third layer 13, resulting in some of the first hollow fine particles 21 being present at the interface between the third layer 13 and the substrate 3 of the third layer 13. In FIG. 3C, the area surrounded by a two-dot chain line indicates the portion of the hollow fine particles 21 buried in the third layer 13. From the viewpoint of realizing such a state in which some of the first hollow fine particles 21 are 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, if 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, mixing of the precursor of the first binder 31 and the precursor of the second binder 32 is likely to occur during the production of the anti-reflection coating 1b. For example, if pores are present in the third layer 13, a liquid composition applied to the surface of the third layer 13 distal to the substrate 3 may penetrate into the pores and fill them. As a result, the second binder 32 may contain the same type of compound as some of the compounds contained in the first binder 31, and the first binder 31 and the second binder 32 may become homogenous. As a result, it is believed that the surface of the third layer 13 softens, and some of the first hollow fine particles 21 become embedded in the third layer 13 and are present at the boundary surface of the third layer 13 distal to the substrate 3. Note that the first binder 31 and the second binder 32 being similar not only means that the components and compositions of both are the same, but also means that the types of compounds contained in the binders, such as alkoxysilanes, are similar, specifically including 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 part of the uncured liquid composition is likely to seep into areas with such pores.

[0089] As shown in FIG. 3C , within a range having a predetermined cross-sectional area of ​​the cross section of the anti-reflection coating 1b, the first hollow particles 21 present at the boundary of the third layer 13 distal to the substrate 3 can be identified and the number of first hollow particles 21 can be counted. Additionally, as shown in FIG. 3D , for each first hollow particle 21 present at this boundary, the proportion of the portion present on the third layer 13 side of the first hollow particle 21 as a whole can be determined. An SEM image of the cross section of the anti-reflection coating 1b at 100,000 magnification is acquired to identify the first layer 11, the second layer 12, and the third layer 13. Then, a target cross section of 500 nm square is designated so as to include all layers in the thickness direction. The first hollow particles 21 present at the boundary of the third layer 13 distal to the substrate 3 and included in the target cross section are identified, and the first hollow particles 21 are approximated by circles. N is the number of first hollow particles 21 included in the target cross section and having portions belonging to the second layer 12 and the third layer 13. M1 , the total area S of the approximate circle of the first hollow fine particle 21 having the portion belonging to the second layer 12 and the third layer 13 L The area S of the partial circle (a shape with a part of the circle missing) included in the region on the third layer 13 side M The ratio S M / S L In the anti-reflection coating 1b, the number N M1 is, for example, 1 to 5, and preferably 3 to 5. 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, and therefore 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 tends to be high.

[0090] 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, Ltd., JMT-150B, JMT-150AO, JMT-150ANO, and MTY-700BS manufactured by Teika Corporation, STT-65C-S and STT-30EHJ manufactured by Titanium Industries Co., Ltd., and OPTOLAKE series manufactured by JGC Catalysts and Chemicals. The fine particles 33 may also 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 also 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 microparticles 33 may be silicon oxide microparticles such as those in the QSG series manufactured by Shin-Etsu Chemical Co., Ltd., the Snowtex series manufactured by Nissan Chemical Industries, Ltd., or the Sururia series manufactured by JGC Catalysts and Chemicals. The microparticles 33 may be magnesium fluoride nanoparticles manufactured by Stella Chemifa. The microparticles 33 may be aluminum oxide microparticles such as those in the Aluminasol 100, 200, and 500 series manufactured by Nissan Chemical Industries, Ltd., or those in the AS-150T and AS-1501 series manufactured by Sumitomo Osaka Cements Co., Ltd. The microparticles 33 may be polyethylene microparticles such as those in the polyethylene particles manufactured by Corefront Co., Ltd. or the Mipelon series manufactured by Mitsui Chemicals, Inc. The microparticles 33 may be polystyrene microparticles such as polystyrene particles manufactured by Corefront Co., Ltd. or polybeads polystyrene manufactured by Techno Chemical Co., Ltd. The microparticles 33 may be ITO microparticles such as those in the ITO series manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd. or those in the P-120 and P-130 series manufactured by JGC Catalysts and Chemicals. The fine particles 33 may be ATO fine particles such as the TI series manufactured by Mitsubishi Materials Electronic Chemicals Corporation. Other fine particles may be added as the fine particles 33, and one type of fine particle may be used alone, or two or more types of fine particles may be mixed together. Furthermore, when conductive fine particles such as ITO and ATO are used as the fine particles 33, the anti-reflection film 1b can exhibit an anti-static function. The fine particles 33 are selected and combined appropriately depending on the application and function required of the anti-reflection film 1b.

[0091] When the third layer 13 is formed 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 of the binder described for the antireflection coating 1a. The second binder 32 may contain at least one selected from the group consisting of alkoxysilane, a hydrolyzate of an alkoxysilane, and a polymer of a hydrolyzate of an alkoxysilane.

[0092] The liquid composition that is the precursor of the third layer 13 may contain, in addition to the precursors of the microparticles 33 and the second binder 32, a crosslinking agent, a polymerization initiator, a leveling agent, a surfactant, a silane coupling agent, etc. as necessary.

[0093] 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 in 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.

[0094] The antireflection coating 1b can be produced, for example, by a method including the following steps (Ib), (IIb), and (IIIb). The antireflection coating 1b includes a first layer and a second layer, which are separated from each other in this order from the surface of the antireflection coating 1b. (Ib) A third layer 13 containing a dielectric 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) The first liquid composition is solidified.

[0095] 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 for applying the second liquid composition onto the substrate 3 is not limited to a specific method. Examples of such methods include roll coating, spray coating, spin coating, coating with a dispenser, inkjet coating, screen printing, and dip coating. Furthermore, for each application method, the conditions for each method can be set depending on the thickness required for the second coating film.

[0096] The method for solidifying the liquid composition is not limited to a specific method. The solidification of the liquid composition may be carried out according to a method that dries the coating film by heating or polymerizes the binder precursor or the like. In this case, heating may be carried out in an environment maintained at about room temperature, particularly in an environment without artificial heating means, such as in a container, a thermostatic chamber, or on a desk, where the liquid composition is left to dry or react and solidify. The solidification of the liquid composition may be carried out by irradiating it with electromagnetic waves such as visible light, ultraviolet light, or microwaves to polymerize the binder precursor or the like.

[0097] The surface of the substrate 3 to which the liquid composition is to be applied may be subjected to various cleaning or surface treatments before application of the liquid composition. The cleaning method for 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 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. These cleaning or surface treatments are expected to provide advantages such as improving the wettability of the liquid composition on the surface of the substrate 3 or generating hydroxyl groups that easily bond with compounds contained in the liquid composition.

[0098] In the production of the antireflective coating 1b, it is preferable to form a coating film of the liquid composition 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 extent before the liquid composition gels. For this reason, it is more preferable to heat the layer constituting the antireflective coating 1b by drying or reacting 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 account the properties required of the antireflective coating 1b, the heat resistance temperature of the substrate 3, and the like. For example, if the heating temperature of the liquid composition is high, 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.

[0099] The parameters of the anti-reflection coating 1b can be calculated in the same manner as the parameters of the anti-reflection coating 1a. For example, an anti-reflection coating 1b is formed on the surface of a substrate 3 or the like, and an anti-reflection coating is formed on the surface of a silicon wafer using the same method and conditions as the anti-reflection coating 1b. SEM images of the cross section are obtained, the thickness of each layer is measured, and the particles contained in each layer are identified, and the average particle diameter and number N are calculated. M1 , and the ratio S M / S L are measured and calculated. Furthermore, the reflection spectrum of the antireflection coating 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 from the actually measured reflection spectrum is minimized within an allowable range. In this way, the parameters of each layer of the antireflection coating 1b can be calculated. The circumstances of the error parameter are as described for the antireflection coating 1a.

[0100] The anti-reflection coating 1a may be modified, for example, to an anti-reflection coating 1c shown in FIG. 4. The anti-reflection coating 1c has the same configuration as the anti-reflection coating 1a, except for portions that will be particularly described. The same reference numerals are used to designate components of the anti-reflection coating 1c that are the same as or correspond to those of the anti-reflection coating 1a, and detailed descriptions thereof will be omitted. The above descriptions regarding the anti-reflection coatings 1a and 1b also apply to the anti-reflection coating 1c, unless technically inconsistent.

[0101] 4, the anti-reflection coating 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 anti-reflection coating 1c. The fourth layer 14 is disposed between the third layer 13 and the substrate 3 in the thickness direction of the anti-reflection coating 1c. The third layer 13 has a refractive index n of 1.30 to 2.25. L3 and a thickness t of 60 nm to 200 nm M3 The fourth layer 14 has a refractive index n L4 and a thickness t of 25 nm or less M4 The refractive index n L3 and n L4 is a value at the D line (589.3 nm). With such a 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 at or below a specific value, is likely to be large.

[0102] In the anti-reflection film 1c, the minimum value r of reflectance in the wavelength range of 300 nm to 1200 nm min(2) is, for example, 1% or less, preferably 0.5% or less, and more preferably 0.2% or less. In the reflection spectrum of the anti-reflection film 1c in the wavelength range of 300 nm to 1200 nm, the wavelength range λ where the reflectance is 1% or less is range / 1.0 is, for example, 250 nm or more.

[0103] Refractive index n L3 is preferably 1.40 to 2.00. M3 is preferably 80 nm to 160 nm. L4 is preferably 1.35 to 1.50.M4 is preferably 20 nm or less.

[0104] For example, in the anti-reflection film 1c, n L3 <n L4 This allows the antireflection film 1c to more easily exhibit high antireflection performance. In the antireflection film 1c, it is preferable that n L1 <n L2 and n L3 <n L4 The conditions are met.

[0105] 4, in the antireflection coating 1c, the first layer 11 and the second layer 12 form a first multi-layer structure 10. In addition, the third layer 13 and the fourth layer 14 form a second multi-layer structure 20. The first multi-layer structure 10 includes first hollow particles 21 and a first binder 31 that binds the first hollow particles 21 together. The second multi-layer structure 20 includes second hollow particles 22 and a second binder 32 that binds the second hollow particles 22 together. With this configuration, the antireflection coating 1c is more likely to exhibit high antireflection performance.

[0106] In the antireflection 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 antireflection film 1c is more likely to exhibit high antireflection performance.

[0107] 4 , the second layer 12 includes, for example, a first portion 12 a and a second portion 12 b. The first portion 12 a is a layered portion disposed on the first layer 11 side of the second layer 12. The second portion 12 b is a layered portion disposed on the third layer 13 side of the second layer 12.

[0108] The anti-reflection coating 1c can be manufactured using, for example, a group of liquid compositions that are precursors of the anti-reflection coating 1c. The group of liquid compositions includes a first liquid composition and a second liquid composition. The first liquid composition includes, for example, precursors of the first hollow fine particles 21 and the first binder 31. The first liquid composition can form the first layer 11 and the first portion 12a of the second layer 12 by solidifying. The second liquid composition includes precursors of the second hollow fine particles 22 and the second binder 32 by solidifying. The second liquid composition can form the second portion 12b of the second layer 12, the third layer 13, and the fourth layer 14 by solidifying.

[0109] The antireflection coating 1c can be produced, for example, by a method including the following steps (Ic) and (IIc): (Ic) forming the second portion 12b of the second layer 12, the third layer 13, and the fourth layer 14 by at least one process selected from the group consisting of drying a second coating film obtained by applying the second liquid composition along the surface of the substrate 3 and a reaction of the second coating film; and (IIc) forming the first portion 12a and the first layer 11 of the second layer 12 by at least one process selected from the group consisting of drying a first coating film obtained by applying the first liquid composition onto the second portion 12b of the second layer 12 and a reaction of the first coating film, and then combining the first portion 12a and the second portion 12b to form the second layer 12.

[0110] The anti-reflection coating 1c may be produced by a method including, for example, 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 hydrolyzates of alkoxysilanes is applied to 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 hydrolyzates of alkoxysilanes is applied to the surface of a solidified product of the second liquid composition; (IVd) The first liquid composition is solidified.

[0111] The antireflection coating 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 antireflection coating 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 hydrolyzed product of alkoxysilane, and a part of the second fine particle.

[0112] In (Id), the mass ratio of the second fine particles to the second liquid composition is, for example, 5% to 75%. In (IIId), the mass ratio of the first hollow fine particles 21 to the first liquid composition is, for example, 80 to 99.5%.

[0113] 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 an alkoxysilane hydrolysate and an alkoxysilane hydrolysate polymer. The predetermined alkoxysilane is, for example, an alkoxysilane that is a precursor of at least one selected from the group consisting of an alkoxysilane hydrolysate and an alkoxysilane hydrolysate polymer, such that 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 molar ratio of trifunctional alkoxysilane to tetrafunctional alkoxysilane is 1 / 4 to 4. According to this configuration, in step (IIc), the first portion 12a and the second portion 12b are united to form substantially the same 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.

[0114] As shown in FIG. 4 , in the anti-reflection coating 1c, the fourth layer 14, which is closest to the substrate 3 among the first layer 11, second layer 12, third layer 13, and fourth layer 14, contains the material that constitutes the outer shell of the hollow microparticles 22. For example, if the first binder 31 and the second binder 32 contain at least one selected from the group consisting of alkoxysilane hydrolysates and polymers of alkoxysilane hydrolysates, and the first hollow microparticles 21 and the second hollow microparticles 22 are composed of compounds primarily composed of silicon oxide, the fourth layer 14 can be filled with a compound primarily composed of silicon oxide. For example, if the outer shell of the second hollow microparticles 22, which are composed of compounds primarily composed of silicon oxide, contains an alkoxysilane hydrolysate or a polymer of the hydrolysate as the main component, the fourth layer 14 will have almost no air-filled portions such as hollow portions or voids, and will be filled with alkoxysilane, alkoxysilane hydrolysates, and polymers of alkoxysilane hydrolysates. Therefore, the refractive index n of the fourth layer 14 is L4 The refractive index n of the fourth layer 14 of the material forming the outer shell of the hollow fine particle 22 can be a value not significantly different from that of silicon oxide or its modified product. L4 and t M4 As long as the thickness is 25 nm or less, the layer may contain materials other than silicon oxide.

[0115] The third layer 13 can 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 shells and hollow portions of the second hollow particles 22, and air having a refractive index of about 1 exists in the hollow portions of the second hollow particles 22 and in the gaps between the second hollow particles 22. Therefore, the refractive index n of the third layer 13 increases as the proportion of the region including such air increases. L3The surface roughness tends to be low. Before the first liquid composition is applied, the second liquid composition is applied, and during the process of forming the second region 12b, the third layer 13, and the fourth layer 14, some of the second hollow particles 22 may be present at the interface of the second region 12b distal to the substrate 3. Like the fourth layer 14, the second region 12b may contain, in addition to the second binder 32, a compound that forms the outer shell of the second hollow particles 22, for example, containing silicon oxide as a main component. When the layer that forms the antireflection coating 1c contains alkoxysilane, a hydrolyzate of alkoxysilane, or a polymer of a hydrolyzate of alkoxysilane, and the second hollow particles 22 are composed of a compound containing silicon oxide as a main component, the second region 12b may be filled with a compound containing silicon oxide as a main component. When the hollow microparticles composed of a compound mainly composed of silicon oxide are formed of a compound mainly composed of an alkoxysilane hydrolysate or a polymer of an alkoxysilane hydrolysate, the second portion 12b is less likely to contain hollow portions or voids, etc., and is filled with the alkoxysilane, the alkoxysilane hydrolysate, or the alkoxysilane hydrolysate polymer. Therefore, in the anti-reflection coating 1c, the refractive index of the second portion 12b can be a value not significantly different from the refractive index of silicon oxide or a modified silicon oxide.

[0116] In step (IIc), the first portion 12a of the second layer 12 and the first layer 11 are formed separately. The formation of the first layer 11 and the first portion 12a in the antireflection coating 1c corresponds to the formation of the first layer 11 and the second layer 12 in the antireflection coating 1a, respectively. Therefore, for the formation of the first layer 11 and the first portion 12a in the antireflection coating 1c, the description of the "second layer 12" in the antireflection coating 1a can be read as the "first portion 12a."

[0117] In the anti-reflection coating 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 primary 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 primary component, as 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 them is 0.01 or less.

[0118] The ratio M 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 L is, for example, the ratio M 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. H With this configuration, the antireflection film 1c is more likely to exhibit high antireflection performance.

[0119] In the liquid composition group which is a precursor of the anti-reflection film 1c, the ratio M L and ratio M H is preferably 0.05≦M H / M L ≦0.85, and more preferably 0.2≦M H / M L ≦0.7 is satisfied, which makes it easier for the antireflection film 1c to exhibit high antireflection performance.

[0120] Ratio M L is, for example, 80% to 99.5%, preferably 85% to 99.5%, more preferably 90% to 99.5%, and even more preferably 95% to 99%. H is, for example, 5% to 70%, and preferably 10% to 50%.

[0121] The method for applying the first and second liquid compositions, which are precursors of the anti-reflection coating 1c, is not limited to a specific method. Examples of such methods include roll coating, spray coating, spin coating, coating with a dispenser, inkjet coating, screen printing, and dip coating. The conditions for the application method are adjusted depending on the desired thickness of the coating film.

[0122] The method for solidifying the first liquid composition and the second liquid composition is not limited to a specific method. The solidification of these liquid compositions may be carried out by a method that dries the coating film by heating or polymerizes the binder precursor or the like. In this case, heating may be carried out in an environment maintained at about room temperature, particularly in an environment without artificial heating means, such as in a container, a thermostatic chamber, or on a desk, where the liquid composition is left to dry or react and solidify. The solidification of the liquid composition may be carried out by polymerizing the binder precursor or the like by irradiation with electromagnetic waves such as visible light, ultraviolet light, or microwaves.

[0123] 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 method for 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 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. These cleaning or surface treatments are expected to provide advantages such as improving the wettability of the liquid composition on the surface of the substrate 3 or generating hydroxyl groups that easily bond with compounds contained in the liquid composition.

[0124] In the production of the antireflective coating 1c, preferably, after forming a coating film of the liquid composition along the surface of the substrate 3, the liquid composition may be allowed to gel relatively slowly. In this case, the fluidity of the microparticles or binder precursor can be maintained to a certain extent before the liquid composition gels. For this reason, it is more preferable to heat the layer constituting the antireflective coating 1c by drying or reacting 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 of the antireflective coating 1c, the heat resistance temperature of the substrate 3, and the like. For example, if the heating temperature of the liquid composition is high, 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.

[0125] The parameters of the antireflection coating 1c can be calculated in the same manner as the parameters of the antireflection coating 1a. For example, an antireflection coating 1c is prepared on the surface of a substrate 3 or the like, and an antireflection coating is prepared on the surface of a silicon wafer using the same method and conditions as the antireflection coating 1c. The process involves obtaining an SEM image of the cross section, measuring the thickness of each layer, identifying the particles contained in each layer, and determining the average particle diameter and the number N. M1 , and the ratio S M / S L are measured and calculated. Furthermore, the reflection spectrum of the antireflection coating 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 from the actually measured reflection spectrum is minimized within an allowable range. In this way, the parameters of each layer of the antireflection coating 1c can be calculated. The circumstances of the error parameter are as described for the antireflection coating 1a.

[0126] The antireflection coatings 1a, 1b, and 1c can be modified in various respects. For example, the antireflection coating may include 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 greater.

[0127] The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0128] <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 a 0.3 mass % formic acid aqueous solution manufactured by Kishida Chemical Co., Ltd. were mixed and stirred to obtain binder precursor A1, which was a transparent liquid composition. The molar ratio of TEOS to MTES in binder precursor A1 was 7:3.

[0129] <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 binder precursor A2, which was a transparent liquid composition. The molar ratio of TEOS to MTES in binder precursor A2 was 5:5.

[0130] <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 Binder Precursor A3, which was a transparent liquid composition. The molar ratio of TEOS to MTES in Binder Precursor A3 was 3:7.

[0131] <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 Binder Precursor A4, which was a transparent liquid composition. The molar ratio of TEOS to MTES in Binder Precursor A4 was 1:9.

[0132] <Binder Precursor A5> 19.2 g of TEOS, 36.1 g of n-propyltrimethoxysilane (n-PTMS), 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 binder precursor A5, which was a transparent liquid composition. The molar ratio of TEOS to n-PTMS in binder precursor A5 was 3:7.

[0133] <Liquid Composition B1> 0.14 g of binder precursor A1 and Sururia 4110 (a dispersion of approximately 20 mass% of substantially 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, Ltd. 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.

[0134] <Liquid composition B2> 2.7 g of binder precursor A2 and Sururia 4110 manufactured by JGC Catalysts and Chemicals, Ltd. were added to 82.3 g of a mixed liquid of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol 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 liquid composition B2 containing hollow fine particles and the binder precursor.

[0135] <Liquid Composition B3> 4.4 g of binder precursor A3 and Sururia 4110 manufactured by JGC Catalysts and Chemicals, Ltd. 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 content mass of the fine particles relative to the total solid content mass was 90%, and the mixture was mixed and stirred to prepare liquid composition B3 containing hollow fine particles and binder precursor.

[0136] <Liquid Composition B4> 3.7 g of binder precursor A4 and Sururia 4110 manufactured by JGC Catalysts and Chemicals, Ltd. were added to 81.3 g of a mixed liquid of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol 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 liquid composition B4 containing hollow fine particles and binder precursor.

[0137] <Liquid Composition B5> 4.4 g of binder precursor A5 and Sururia 4110 manufactured by JGC Catalysts and Chemicals, Ltd. 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 content mass of the fine particles relative to the total solid content mass was 95%, and the mixture was mixed and stirred to prepare liquid composition B5 containing hollow fine particles and binder precursor.

[0138] <Liquid Composition B6> 14.8 g of 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 liquid composition B6 containing the binder precursor.

[0139] <Liquid composition B7> 14.8 g of binder precursor A1 and Sururia 4110 manufactured by JGC Catalysts and Chemicals, Ltd. were added to 82.8 g of a mixed liquid of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol so that the solid content mass of the fine particles relative to the total solid content mass was 13.1%, and the mixture was mixed and stirred to prepare liquid composition B7 containing the fine particles and the binder precursor.

[0140] <Liquid Composition B8> 14.8 g of binder precursor A3 and Sururia 4110 manufactured by JGC Catalysts and Chemicals, Ltd. were added to 82.8 g of a mixed liquid of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol 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 liquid composition B8 containing the fine particles and the binder precursor.

[0141] <Liquid Composition B9> 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, Ltd. were added to 71.4 g of a mixed liquid of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol 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 liquid composition B9 containing the fine particles and the binder precursor.

[0142] <Liquid composition B10> 0.04 g of binder precursor A1 and Sururia 4110 manufactured by JGC Catalysts and Chemicals, Ltd. were added to 86.2 g of a mixed liquid of 1-methoxy-2-propanol and 3-methoxy-3-methyl-1-butanol so that the solid content mass of the fine particles relative to the total solid content mass was 99.8%, and the mixture was mixed and stirred to prepare liquid composition B10 containing hollow fine particles and the binder precursor.

[0143] Example 1 A substrate was made of Corning borosilicate glass D263 T eco (refractive index n D A substrate (with a refractive index of 1.5230) was used. The substrate was properly cleaned 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, followed by spin coating to form a coating film. The substrate had a square shape with a side length of 70 mm in plan view. Next, the substrate with the coating film formed thereon was placed inside a thermostatic dryer and left at 30°C for 30 minutes, after which the temperature inside the thermostatic dryer was adjusted to 200°C and maintained at 200°C for 10 minutes. The temperature inside the thermostatic dryer was then allowed to naturally cool to room temperature, and the substrate with the low refractive index layer was removed from the thermostatic dryer, thereby producing the antireflection film of Example 1.

[0144] Example 2 A substrate was prepared using Corning borosilicate glass D263 T eco (refractive index n DA substrate (of 1.5230 mm diameter) was used, and the substrate was properly washed with an alkaline solution and an organic solvent. 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 had been formed was left standing inside the thermostatic chamber. After 10 minutes had passed, the substrate was removed from the thermostatic chamber and left standing in a room at room temperature of 25°C to cool the substrate, thereby producing an antireflection film according to Example 2.

[0145] 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.

[0146] Example 4: As a substrate, a Corning borosilicate glass D263 T eco (refractive index n D A substrate (H: 1.5230) was used, and the substrate was properly cleaned with an alkaline solution and an organic solvent. An appropriate amount of Liquid Composition B6 was dropped onto one major 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 with the coating film formed thereon was left standing inside the thermostatic chamber. After 10 minutes, the substrate was removed from the thermostatic chamber and left standing in a room at room temperature of 25°C to cool the substrate, thereby forming a lower layer according to Example 4. Next, an appropriate amount of Liquid Composition B1 was dropped onto the surface of this lower layer, 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 with the coating film formed thereon was left standing inside the thermostatic chamber. After 10 minutes, the substrate was removed from the thermostatic chamber and left standing in a room at room temperature of 25°C to cool the substrate, thereby producing an anti-reflection film according to Example 4.

[0147] 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.

[0148] 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.

[0149] Example 7 An anti-reflection film according to Example 7 was produced in the same manner as in Example 4, except that Liquid Composition B9 was used instead of Liquid Composition B6.

[0150] Example 8 A substrate was prepared using Corning borosilicate glass D263 T eco (refractive index n D A substrate (w / w 1.5230) was used, and the substrate was properly cleaned with an alkaline solution and an organic solvent. A SiO2 monolayer film was formed on one major surface of the substrate by vacuum deposition. The thickness of the SiO2 monolayer film was 103 nm. Next, an appropriate amount of Liquid Composition B3 was dropped onto the surface of the SiO2 monolayer film, and a coating film was formed by spin coating. The temperature inside the thermostatic chamber was previously adjusted to 200°C, and the substrate with the coating film formed thereon was left standing inside the thermostatic chamber. After 10 minutes, the substrate was removed from the thermostatic chamber and left standing in a room at room temperature of 25°C to cool the substrate, thereby producing the anti-reflection film of Example 8.

[0151] 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.

[0152] Table 1 shows the anti-reflection films according to the examples and the conditions for the liquid compositions used to prepare these anti-reflection films.

[0153] <Antireflection film for fitting> For fitting of the reflectance 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 the base material instead of the D263 T eco substrate.

[0154] <Measurement of reflectance and reflection spectrum> For the antireflection coating according to each example, the reflection spectrum was measured at an incident angle of 5° using a UV-visible-near-infrared 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 a film formed on a 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.

[0155] <Observation of the Cross Section of the Antireflective Film> The antireflective 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 vapor deposition to prepare a sample. The sample was observed using a Hitachi High-Technologies field emission scanning electron microscope (FE-SEM) SU8220, and a 100,000-magnification SEM image of the cross section of the antireflective film according to each example was obtained. In the obtained 100,000-magnification SEM image of the cross section of the antireflective film according to each example, a 500 nm square region was identified so as to include all layers in the thickness direction, and fine particles present within the region were identified, 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 were recognizable within more than half of the circle's area were identified, and the diameter of those circles was measured, and the measured value was defined as the diameter of each fine particle. The arithmetic average of the diameters of all fine particles present in the 500 nm square region was calculated to obtain the average particle diameter D of the fine particles contained in each layer of the antireflective film according to each example. p asked for.

[0156] In addition, in each SEM image of the cross section of the anti-reflection coating according to Examples 4 to 9, particles approximated by a circle were identified in a 500 nm square area that was specified so as to include all layers in the thickness direction, and the number N of particles that were partially buried in the layer closest to the substrate at the boundary between the layers was calculated. M1 In addition, the area S of the approximate circle of the particle that is partly buried in the layer closer to the substrate at the boundary between the layers was calculated. L and the area S corresponding to the partially circular part buried in the approximate circle. M Calculate the ratio S M / S Lasked for.

[0157] In each of the SEM images, a substantially 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 anti-reflection coatings according to Examples 1 to 3, the thickness t of the entire layer including the first layer and the second layer was LL In the SEM images of the cross sections of the antireflection coatings according to Examples 4 and 7, the thickness t of the entire layer including the first layer and the second layer was measured. LL and the thickness of the third layer t M3 In the SEM images of the cross sections of the antireflection coatings according to Examples 5 and 6, the thickness t of the entire layer including the first layer and the second layer was measured. LL and the thickness t of the layer including the third and fourth layers MM was measured. In Examples 1 to 3, the first layer and the second layer were arranged in this order facing the substrate. In Examples 4 and 7, the first layer, the second layer, and the third layer were arranged in this order facing 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 facing the substrate. 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. In Figs. 9 and 10, the areas surrounded by white dashed lines indicate the average particle diameter D p , the number of particles N M1 , ratio S M / S L 5 shows a 500 nm square area selected for determining .

[0158] <Fitting of Reflection Spectra> Using TFCalc (registered trademark), an optical thin film coating property calculation software manufactured by HULINKS, parameters such as the refractive index and thickness of the layers included in each film according to each Example were calculated by fitting the measured reflection spectrum of the film according to each Example formed on a silicon wafer with the reflection spectrum calculated by simulation. The refractive index and thickness calculated in this way can be considered as the refractive index and thickness of each layer in the antireflection coating according to each Example.

[0159] For Examples 1 to 3, the refractive index n of the first layerL1 , the refractive index of the second layer n L2 , the thickness of the first layer t L1 , and the thickness of the second layer t L2 The thickness of the second layer t L2 It can be assumed that the binder contained in the second layer is unevenly distributed on the surface of the second layer and the substrate, and the thickness t L2 could be assumed to be 2 nm.

[0160] For Examples 4 and 7, the refractive index n L1 , the refractive index of the second layer n L2 , the refractive index of the third layer n L3 , the thickness of the first layer t L1 , the thickness of the second layer t L2 , and the thickness of the third layer t M3 The thickness of the second layer t L2 It can be assumed that the binder contained in the second layer is unevenly distributed on the surface of the second layer and the substrate, and the thickness t L2 could be assumed to be 2 nm.

[0161] For Examples 5, 6, and 9, the refractive index of the first layer n L1 , the refractive index of the second layer n L2 , the refractive index of the third layer n L3 , the refractive index of the fourth layer n L4 , the thickness of the first layer t L1 , the thickness of the second layer t L2 , the thickness of the third layer t M3 , and the thickness of the fourth layer t M4 The thickness of the second layer t L2 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 and second layers.

[0162] <Adhesion Test> The adhesion test of the antireflection coating according to the example was carried out under the conditions and by the method (cross-cut peel test) in accordance with Japanese Industrial Standards (JIS) K5600-5-6. Six vertical and horizontal cut lines were made at 1 mm intervals on the surface of the antireflection coating according to the example, forming a cut line pattern of 25 squares with a side length of 1 mm in plan view. This antireflection coating substrate was placed on a flat glass table, and adhesive tape was applied to the antireflection coating with a pressure of 3.3 N / cm. 2 The adhesive tape was applied with a surface pressure of 100 psi, and then peeled off from the surface of the anti-reflection film over one second while lifting the edge of the tape at a 60° angle. The adhesive tape used was cleanroom cellophane tape CRCT-18 manufactured by Nichiban Co., Ltd. Cellophane tape is a registered trademark. The application and peeling of the adhesive tape was performed twice over the entire surface of the anti-reflection film on which the cut line pattern was formed. The adhesion of each anti-reflection film was evaluated according to the following evaluation criteria. The results are shown in Table 2. As shown in Table 2, the anti-reflection films of Examples 1 to 8 had high adhesion to the anti-reflection film of Example 9. A: Of the 25 squares, 0 squares peeled off. B: Of the 25 squares, 0 or more but less than 5% of the squares peeled off. C: Of the 25 squares, 5% or more but less than 15% of the squares peeled off. D: Of the 25 squares, 15% or more but less than 35% of the squares peeled off. E: The number of peeled squares out of 25 squares is 35% or more.

[0163]

[0164]

Claims

1. An anti-reflective coating provided on a substrate, The anti-reflective coating comprises a first layer and a second layer, in order from the surface side of the anti-reflective coating. The aforementioned layer has a refractive index n of 1.10 to 1.

35. L1 and having a thickness of 80 nm to 150 nm, The second layer has a refractive index n of 1.30 to 1.

55. L2 and having a thickness of 25 nm or less, Anti-reflective coating.

2. n L1 <n L2 The following conditions are met: The anti-reflective coating according to claim 1.

3. The anti-reflective film comprises first hollow fine particles and a first binder that binds the first hollow fine particles, and the content of the first hollow fine particles in the anti-reflective film is 80% to 99.5% by mass. The anti-reflective coating according to claim 1 or 2.

4. The first hollow fine particles have an average particle size D of 5 nm to 200 nm. p Having, The anti-reflective coating according to claim 3.

5. The first binder comprises at least one selected from the group consisting of alkoxysilanes, hydrolysates of alkoxysilanes, and polymers of hydrolysates of alkoxysilanes. The anti-reflective coating according to claim 3.

6. The minimum reflectance within the wavelength range of 400 nm to 800 nm is 0.5% or less. The anti-reflective coating according to claim 1 or 2.

7. The range λ in which the reflectance is 1% or less within the wavelength range of 300 nm to 1200 nm. range / 1.0 It is 250 nm or more. The anti-reflective coating according to claim 1 or 2.

8. The third layer is further disposed between the second layer and the substrate, The third layer has a refractive index n of 1.30 to 2.

25. L3 and having a thickness of 60 nm to 200 nm, The anti-reflective coating according to claim 1 or 2.

9. n L1 <n L3 <n L2 where the condition is satisfied The anti-reflective coating according to claim 8.

10. The aforementioned first layer and the aforementioned second layer constitute a first multilayer structure, The first multilayer structure includes first hollow fine particles and a first binder that binds the first hollow fine particles together. The third layer includes at least a second binder. The anti-reflective coating according to claim 8.

11. A third layer is disposed between the second layer and the substrate, The system further comprises a fourth layer disposed between the third layer and the substrate, The third layer has a refractive index n of 1.30 to 2.

25. L3 and having a thickness of 60 nm to 200 nm, The fourth layer has a refractive index n of 1.30 to 1.

55. L4 and having a thickness of 25 nm or less, The anti-reflective coating according to claim 1 or 2.

12. The aforementioned first layer and the aforementioned second layer constitute a first multilayer structure, The third and fourth layers have a second multilayer structure. The first multilayer structure includes first hollow fine particles and a first binder that binds the first hollow fine particles together. The second multilayer structure includes second hollow fine particles and a second binder that binds the second hollow fine particles together. The anti-reflective coating according to claim 11.

13. 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.

14. A liquid composition, First hollow particle and A compound comprising at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes, The mass ratio of the first hollow fine particles to the solid content of the liquid composition is 80% to 99.5%. Liquid composition.

15. The alkoxysilane includes tetrafunctional alkoxysilanes and trifunctional alkoxysilanes. The ratio of the amount of substance of the tetrafunctional alkoxysilane to the amount of substance of the trifunctional alkoxysilane is 1 / 9 to 9. The liquid composition according to claim 14.

16. A group of liquid compositions, A first liquid composition comprising first hollow fine particles and a precursor of the first binder, A second liquid composition comprising a second hollow fine particle and a precursor of a second binder, The first liquid composition is capable of forming a first layer and a first portion of the second layer upon solidification. The second liquid composition is capable of forming a second portion of the second layer, a third layer, and a fourth layer upon solidification. A group of liquid compositions.

17. The aforementioned layer has a refractive index n of 1.10 to 1.

35. L1 and having a thickness of 80 nm to 150 nm, The second layer has a refractive index n of 1.30 to 1.

55. L2 and having a thickness of 25 nm or less, The third layer has a refractive index n of 1.30 to 2.

25. L3 and having a thickness of 60 nm to 200 nm, The fourth layer has a refractive index n of 1.30 to 1.

55. L4 and having a thickness of 25 nm or less, The group of liquid compositions according to claim 16.

18. The 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 the 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. The group of liquid compositions according to claim 16 or 17.

19. A method for manufacturing an anti-reflective coating, A first liquid composition comprising first hollow fine particles and at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes is applied to a substrate. The first liquid composition is solidified, The mass ratio of the first hollow fine particles to the first liquid composition is 80% to 99.5%. The anti-reflective coating comprises a first layer and a second layer separated in order from the surface of the anti-reflective coating. A method for manufacturing an anti-reflective coating.

20. The aforementioned layer has a refractive index n of 1.10 to 1.

35. L1 and having a thickness of 80 nm to 150 nm, The second layer has a refractive index n of 1.30 to 1.

55. L2 and having a thickness of 25 nm or less, n L1 <n L2 The following conditions are met: A method for manufacturing an anti-reflective film according to claim 19.

21. The anti-reflective coating has a minimum reflectance of 0.5% or less in the wavelength range of 400 nm to 800 nm, and a reflectance of 1% or less in the wavelength range of 300 nm to 1200 nm. range / 1.0 Having a reflectance spectrum of 250 nm or more, A method for manufacturing an anti-reflective film according to claim 19 or 20.

22. The second layer comprises a part of the outer shell of the first hollow microparticle and a part of the polymer of the hydrolyzed alkoxysilane. A method for manufacturing an anti-reflective film according to claim 19 or 20.

23. A method for manufacturing an anti-reflective coating, Forming a third layer containing a dielectric on the substrate, A first liquid composition comprising first hollow fine particles and at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes is applied to the surface of the third layer. The first liquid composition is solidified, The anti-reflective coating comprises a first layer and a second layer separated in order from the surface of the anti-reflective coating, The aforementioned layer has a refractive index n of 1.10 to 1.

35. L1 and having a thickness of 80 nm to 150 nm, The second layer has a refractive index n of 1.30 to 1.

55. L2 and having a thickness of 25 nm or less, The third layer has a refractive index n of 1.30 to 2.

25. L3 and having a thickness of 60 nm to 200 nm, n L1 <n L2 The following conditions are met: A method for manufacturing an anti-reflective coating.

24. The third layer includes the following layers (i) and / or (ii): A method for manufacturing an anti-reflective film according to claim 23. (i) SiO 2 MgF 2 , TiO 2 Ta 2 O 3 AlF 3 CaF 2 Al 2 O 3 , ZrO 2 WO 3 , CEO 2 A layer comprising a dielectric film containing one or more oxides selected from the group consisting of indium tin oxide and antimony tin oxide. (ii) SiO 2 , TiO 2 , ZrO 2 , CEO 2 A layer comprising oxide fine particles composed of one or more materials selected from the group consisting of indium tin oxide and antimony tin oxide, and a binder for binding the oxide fine particles.

25. A method for manufacturing an anti-reflective coating, A second liquid composition comprising a second fine particle containing an oxide and at least one selected from the group consisting of alkoxysilanes and hydrolysates of alkoxysilanes is applied to a substrate. To solidify the second liquid composition, A first liquid composition comprising first hollow fine particles 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. The first liquid composition is solidified, The anti-reflective coating comprises, in order from the surface of the anti-reflective coating, a first layer, a second layer, a third layer, and a fourth layer, separated from each other. The second layer comprises a portion of the outer shell of the first hollow microparticle, a portion of the polymer of the hydrolyzed alkoxysilane, and a portion of the second microparticle. A method for manufacturing an anti-reflective coating.

26. The aforementioned layer has a refractive index n of 1.10 to 1.

35. L1 and having a thickness of 80 nm to 150 nm, The second layer has a refractive index n of 1.30 to 1.

55. L2 and having a thickness of 25 nm or less, The third layer has a refractive index n of 1.30 to 2.

25. L3 and having a thickness of 60 nm to 200 nm, The fourth layer has a refractive index n of 1.30 to 1.

55. L4 and having a thickness of 25 nm or less, n L1 <n L2 and n L3 <n L4 The following conditions are met: A method for manufacturing an anti-reflective film according to claim 25.

27. The 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 manufacturing an anti-reflective film according to claim 25 or 26.