JP2015158544A - Antireflective coating material for optical element, antireflection film, and optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antireflection film for an optical element, in which generation of air bubbles on an interface is inhibited and cracks in the film are prevented, and an optical element.SOLUTION: The antireflection film for an optical element comprises at least an epoxy resin, a colorant, and fine particles. The fine particles have a film elastic modulus (Ef), described by the following expression (1), of 0.01 GPa or more and 7 GPa or less and have an average particle diameter of 50 nm or more and 200 nm or less; and the fine particles are included in a content of 7 mass% or more and 25 mass% or less in the antireflection film. Expression (1): Ef=(Ec-EmVm)/Vf, where Ef represents a film elastic modulus (GPa) of the fine particles; Ec represents a film elastic modulus (GPa) of a composite material comprising 20 pts.mass of the fine particles and 80 pts.mass of an epoxy resin; Em represents a film elastic modulus (GPa) of a single epoxy resin; Vm represents a volume ratio of the epoxy resin; and Vf represents a volume ratio of the fine particles.

Description

  The present invention relates to an antireflection coating for an optical element, an antireflection film, and an optical element having the antireflection film.

  Conventionally, optical elements used in optical devices such as cameras, binoculars, microscopes, and semiconductor exposure apparatuses are provided with a black anti-reflection film outside the optically effective portion as necessary to reduce stray light. Yes. The stray light that reaches the outer periphery of the lens of the optical element is sufficiently absorbed by the antireflection film, and unnecessary light such as flare and ghost is reduced.

  The antireflection film for an optical element is a coating film formed mainly on the surface of an optical member that is a constituent member of the optical element, for example, glass. Here, the glass may be a lens or a prism. Other optical glasses may also be used.

  Here, the role of the antireflection film for the optical element will be described with reference to the drawings. FIG. 1 is a schematic view showing an optical member having an antireflection film formed outside the optically effective surface. Specifically, FIG. 1 shows an example of a lens provided with an antireflection film for an optical element. As shown in FIG. 1, the antireflection film 1 for an optical element is formed on an arbitrary outer peripheral portion 7 outside the optically effective surface 9 of the lens 2. Here, of the light incident on the lens 2, the light (incident light 3) that does not hit the outer peripheral portion that is the optically effective surface 8 of the lens 2 is transmitted as transmitted light 4. On the other hand, light (incident light 5) that hits the outer peripheral portion 7 of the lens 2 out of the light incident on the lens 2 hits the antireflection film 1 provided on the outer peripheral portion 7 of the lens 2. If the antireflection film 1 is not formed, the light hitting the outer peripheral portion 7 of the lens 2 is reflected from the inner surface and goes out of the lens 2 as the inner surface reflected light 6 not related to the image. The inner surface reflected light 6 causes flare, ghost, and the like, which are elements that deteriorate the image. For this reason, it is necessary to provide the antireflection film 1 on the outer periphery of the lens 2 for the purpose of preventing the occurrence of flare, ghost, and the like. By providing the antireflection film 1 here, it is possible to reduce internal reflection with respect to the incident light 5 from an oblique direction. As a result, the internal reflection light 6 that adversely affects the image is reduced, and flare and ghost can be prevented.

  This antireflection film is expected to have an effect of reducing stray light that enters the antireflection film from the inside of the optical element, and is required to suitably reduce reflected light called internal reflection. In addition, an optical element on which an antireflection film is formed is required to have high quality in terms of appearance. Further, in addition to the above-mentioned reduction of internal reflection and high appearance quality, the antireflection film is required to have environmental durability, that is, resistance under high temperature and high humidity.

  In recent years, since an optical element on which an antireflection film is formed is configured in various shapes, the antireflection film is often provided at a position that can be seen by a user, and a higher appearance quality is required. Specifically, it is required to suppress appearance defects due to bubbles generated when an antireflection paint for an optical element is applied.

  Since the edge portion where the antireflection film is formed has irregularities, air bubbles are inevitably involved when applying the antireflection coating for the optical element. FIG. 2 is an explanatory diagram showing the growth state of bubbles when an antireflection paint is applied, and shows the growth state of bubbles generated when the coating film 12 is dried after the antireflection paint is applied to the lens 11. . Here, as shown in FIG. 2, the entrained bubbles 13 are combined with other bubbles to form large bubbles 14 or remain at the interface or rupture and penetrate to the film surface.

  In the optical element formed with such an antireflection film, the remaining bubbles are seen as innumerable white spots, and the quality of the appearance is deteriorated. Conventionally, in order to suppress poor appearance due to bubbles, a method of suppressing bubble growth by reducing the fluidity of the paint with silica fine particles and a low boiling point solvent and increasing the viscosity is known (see Patent Document 1). .

JP 2012-155180 A

  However, when silica fine particles are used as in Patent Document 1 to suppress bubbles generated at the interface between the outer peripheral portion of the optical member and the antireflection film when an antireflection coating for an optical element is applied, the silica fine particles There are problems that the antireflection film itself has a high elastic modulus due to a plurality of types of inorganic fine particles containing, and the antireflection film is easily broken under high temperature and high humidity, resulting in poor environmental durability.

  The present invention has been made in view of such background art, and provides an antireflection coating for an optical element that suppresses the generation of bubbles at the interface of the antireflection film and prevents the antireflection film from cracking. To do. In addition, the present invention provides an antireflection film for an optical element that suppresses the generation of bubbles at the interface and prevents film cracking, and an optical element having the antireflection film.

An antireflective coating that solves the above problem is an antireflective coating for optical elements containing at least an epoxy resin, a colorant, fine particles, and a solvent, and is represented by the following formula (1) of the fine particles. The film elastic modulus (Ef) is 0.01 GPa or more and 7 GPa or less, the average particle diameter of the fine particles is 50 nm or more and 200 nm or less, and the content of the fine particles is 3% by mass or more and 14% by mass or less. And
Formula (1) Ef = (Ec−EmVm) / Vf
(In the formula, Ef is the film elastic modulus (GPa) of fine particles, Ec is the film elastic modulus (GPa) of a composite material composed of 20 parts by mass of fine particles and 80 parts by mass of epoxy resin, and Em is the film elastic modulus (GPa) of a single epoxy resin. Vm represents the volume ratio of the epoxy resin, and Vf represents the volume ratio of the fine particles.)

An antireflection film that solves the above problem is an antireflection film for an optical element containing at least an epoxy resin, a colorant, and fine particles, and the film elasticity of the fine particles represented by the following formula (1): The rate (Ef) is 0.01 GPa or more and 7 GPa or less, the average particle diameter of the fine particles is 50 nm or more and 200 nm or less, and the content of the fine particles is 7% by mass or more and 25% by mass or less.
Formula (1) Ef = (Ec−EmVm) / Vf
(In the formula, Ef is the film elastic modulus (GPa) of fine particles, Ec is the film elastic modulus (GPa) of a composite material composed of 20 parts by mass of fine particles and 80 parts by mass of epoxy resin, and Em is the film elastic modulus (GPa) of a single epoxy resin. Vm represents the volume ratio of the epoxy resin, and Vf represents the volume ratio of the fine particles.)

  An optical element that solves the above problem is an optical element having an antireflection film outside the optically effective surface of an optical member, wherein the antireflection film is the antireflection film described above.

  According to the present invention, it is possible to provide an antireflection coating for an optical element that suppresses the generation of bubbles at the interface of the antireflection film and prevents the antireflection film from cracking. In addition, according to the present invention, it is possible to provide an antireflection film for an optical element that suppresses generation of bubbles at the interface and prevents film cracking, and an optical element having the antireflection film.

It is the schematic which shows the optical member by which the antireflection film is formed out of the optical effective surface. It is explanatory drawing which shows the growth state of the bubble at the time of apply | coating an antireflection coating.

  Hereinafter, preferred embodiments of the present invention will be described.

(Anti-reflective paint)
First, the antireflection paint according to the present invention will be described.

An antireflection paint according to the present invention is an antireflection paint for an optical element containing at least an epoxy resin, a colorant, fine particles, and a solvent, and is a film represented by the following formula (1) of the fine particles. The elastic modulus (Ef) is 0.01 GPa to 7 GPa, the average particle diameter of the fine particles is 50 nm to 200 nm, and the content of the fine particles is 3% to 14% by mass. .
Formula (1) Ef = (Ec−EmVm) / Vf
(In the formula, Ef is the film elastic modulus (GPa) of fine particles, Ec is the film elastic modulus (GPa) of a composite material composed of 20 parts by mass of fine particles and 80 parts by mass of epoxy resin, and Em is the film elastic modulus (GPa) of a single epoxy resin. Vm represents the volume ratio of the epoxy resin, and Vf represents the volume ratio of the fine particles.)

  The antireflection paint of the present invention contains at least an epoxy resin, a colorant, fine particles, second fine particles, a solvent, and other components.

  The epoxy resin contained in the antireflection paint of the present invention preferably has good adhesion to a substrate such as glass or plastic. Moreover, in order to improve the refractive index of the whole film, it is more preferable that the refractive index of the curable epoxy resin itself is also high. The content of the epoxy resin contained in the antireflection coating of the present invention is preferably 5% by mass or more and 50% by mass or less, and preferably 10% by mass or more and 40% by mass or less.

  Examples of the fine particles contained in the antireflection paint of the present invention include rubber-based, polyethylene-based, polyethersulfone-based, epoxy-based, acrylic-based, polystyrene-based, polyphenylene sulfide-based, polyamide-imide-based organic fine particles, and mixtures thereof. .

As for the film elastic modulus (Ef) of the fine particles, the value of the film elastic modulus (Ef) represented by the following formula (1) is 0.01 GPa to 7 GPa, preferably 0.1 GPa to 7 GPa.
Formula (1) Ef = (Ec−EmVm) / Vf

  The film elastic modulus (Ef: GPa) of the fine particles is measured using a dynamic viscoelasticity tester (Rhegel-E4000). First, a sample of a single epoxy resin and a sample of a composite material composed of 20 parts by mass of fine particles and 80 parts by mass of an epoxy resin are prepared. Each sample is formed to have a width of 5 mm, a length of 30 mm, and a thickness of 100 μm. The film elastic modulus (Em: GPa) of the single epoxy resin is measured. Further, the film elastic modulus (Ec: GPa) of the composite material is measured. Assuming that the volume (V) ratio of the constituent material in the composite material is equal to the ratio of the cross section, the elastic modulus of the fine particles is calculated from the above formula (1) according to the composite law. Vm represents a volume ratio of the epoxy resin, and Vf represents a volume ratio of the fine particles.

  If the film elastic modulus of the fine particles exceeds 7 GPa, bubbles in the antireflection film can be suppressed, but the environmental durability is low and film cracking occurs. Also, if fine particles having a film elastic modulus of less than 0.01 GPa are formed in the antireflection film, the mechanical film characteristics are not sufficiently improved, so that practical use is difficult.

  The content of the fine particles contained in the antireflection coating of the present invention is 3% by mass to 15% by mass, preferably 3% by mass to 14% by mass. When the content of the fine particles of the present invention is less than 3% by mass, the generation of bubbles cannot be suppressed. On the other hand, when the content of fine particles exceeds 15% by mass, the environmental durability is low and film cracking occurs.

  Furthermore, the average particle size of the fine particles contained in the antireflection paint of the present invention is 50 nm to 200 nm, preferably 50 nm to 100 nm. When the average particle size of the fine particles is less than 50 nm, the stability of the antireflection coating is deteriorated. When the average particle diameter exceeds 200 nm, scattering by fine particles increases, so that the function as an antireflection film is lowered and the effect of suppressing bubbles is weakened.

  The colorant contained in the antireflection paint of the present invention is generally a dye. However, instead of the dye, an organic compound that absorbs visible light having a wavelength of 400 nm to 700 nm and has transparency and can be dissolved in any solvent may be used. Note that one kind of dye may be used, or the absorption of internally reflected light may be adjusted by mixing several kinds of dyes such as black, red, yellow, and blue.

  The content of the colorant contained in the antireflection coating of the present invention is 5% by mass or more and 30% by mass or less, preferably 10% by mass or more and 15% by mass or less.

  The antireflection paint of the present invention preferably further contains second fine particles. As the second fine particles, inorganic fine particles having a refractive index (nd) of 2.2 or more are preferable.

  Since the inorganic fine particles having a refractive index (nd) of 2.2 or more have an effect of increasing the refractive index of the antireflection film, the effect of further reducing internal reflection is brought about. On the other hand, when the inorganic fine particles having a refractive index (nd) lower than 2.2 are used, the refractive index difference relative to the substrate is increased because the increase in the refractive index of the antireflection film is small. For this reason, the internal reflection preventing effect is lowered. The refractive index here refers to the refractive index of the d-line. The refractive index of the inorganic fine particles is preferably 2.2 or more and 3.5 or less. As an example of the inorganic fine particles of the second fine particles, nano-dispersed fine particles of titanium oxide, zirconium oxide, aluminum oxide, yttrium oxide, cadmium oxide, diamond, strontium titanate, germanium, and the like can be given.

  The average particle size of the inorganic fine particles having a refractive index (nd) of 2.2 or more is 10 nm to 100 nm, preferably 10 nm to 20 nm. The average particle diameter of the inorganic fine particles having a refractive index (nd) of 2.2 or more is preferably small, but the lower limit of the practical size is about 10 nm in view of the level of dispersion technology. Moreover, it is not preferable that the average particle diameter exceeds 100 nm because the refractive index cannot be improved efficiently. The average particle diameter of the inorganic fine particles is defined as the actual size of the particles present in the antireflection film. For example, when the average particle size of the inorganic fine particles is aggregated, the aggregated mass is defined as a particle, and the size of this mass is used as an evaluation factor for the average particle size.

  The content of the second fine particles contained in the antireflection paint of the present invention is 10% by mass to 40% by mass, preferably 20% by mass to 35% by mass. When the content of the second fine particles is less than 10% by mass, the increase in the refractive index of the formed thin film is reduced, so that the internal reflection is increased. On the other hand, if the content of the second fine particles exceeds 40% by mass, the adhesion and durability of the coating film are lowered, which is not preferable.

  The antireflection paint of the present invention can further contain other components. As one of the other components, for the purpose of forming irregularities on the surface and suppressing the reflection of the surface, particles having a larger particle diameter than the above-described fine particles may be included. Examples of the particles having a large particle diameter include silica, sericite, and a mixture thereof.

  The average particle size of these large particles is preferably 1 μm or more and 11 μm or less, and preferably 9 μm or more and 11 μm or less. When the average particle diameter is less than 1 μm, the unevenness difference is reduced and it becomes difficult to suppress surface reflection. On the other hand, when the average particle diameter exceeds 11 μm, the surface reflection is small, but the film thickness varies greatly, so that it is difficult to form a coating film with high accuracy.

  Further, as other optional components, an optional coupling agent, an optional plasticizer, an optional antifoaming agent, an optional leveling agent, an optional antifungal agent, an optional antioxidant and the like may be contained.

  The solvent contained in the antireflection paint of the present invention is preferably an organic solvent. The organic solvent is not particularly limited as long as it can dissolve necessary components such as a curable resin and a colorant, but known low-polar organic solvents such as hydrocarbon solvents and aromatic solvents, ethers, and the like. It is possible to select a known polar organic solvent such as a system solvent, an ester solvent, a ketone solvent, or an amide solvent, more preferably a known organic solvent such as an ether solvent, an ester solvent, a ketone solvent, or an amide solvent. One or more polar organic solvents, more preferably propylene glycol monomethyl ether (hereinafter referred to as PGMEA) and propylene glycol monomethyl ether acetate (hereinafter referred to as PGMEA) can be selected.

  The content of the solvent contained in the antireflection paint of the present invention is 5% by mass or more and 50% by mass or less, preferably 10% by mass or more and 15% by mass or less.

  In the antireflection paint of the present invention, the viscosity of the antireflection paint is preferably 50 mPa · s or more and 1000 mPa · s or less, more preferably 100 mPa · s or more and 1000 mPa · s or less. When the viscosity of the antireflection paint is less than 50 mPa · s, the amount of bubbles generated increases. On the other hand, when the viscosity of the antireflective coating exceeds 1000 mPa · s, the coatability is remarkably deteriorated, and application failure may occur.

  In addition to the organic solvent, curable resin, and colorant described above, an additive may be appropriately added to the antireflection paint of the present invention. Hereinafter, specific additives will be described.

  In the present invention, when an epoxy resin is used as the curable resin contained in the antireflection paint of the present invention, it is preferable that the paint further contains a curing agent. The curing agent only needs to be able to cure the epoxy, and examples thereof include, but are not limited to, amine-based, acid anhydride-based, and imidazole-based curing agents.

  The antireflection paint of the present invention may contain a material (refractive index control agent) for controlling the refractive index of the antireflection film to be applied and formed. Examples of the refractive index control agent include, but are not limited to, coal tar and the like in addition to inorganic fine particles having a refractive index (nd) of 2.2 or more.

(Production method of anti-reflection paint)
The antireflection paint of the present invention can be prepared by adding the above-mentioned materials, mixing and dispersing. Examples of the mixing / dispersing method include a ball mill, a bead mill, a collision dispersing device, a planetary rotary stirring device, a homogenizer, a stirrer, and the like, but any method may be used.

  Incidentally, inorganic fine particles having a refractive index (nd) of 2.2 or more need to be nano-dispersed. As a specific method of nano-dispersion, there is a method of nano-dispersing with a bead mill or a collision dispersing device. Further, it may be synthesized by a sol-gel method and nano-dispersed at the time of synthesis, or a commercial product nano-dispersed in advance may be used.

  Moreover, you may add arbitrary surface treating agents and a dispersing agent regarding manufacture of a slurry. As the material of the inorganic fine particles having a refractive index (nd) of 2.2 or more, titanium oxide, zirconium oxide, and aluminum oxide having a high refractive index and high transparency are preferable.

  Although any organic solvent can be used as the solvent for the slurry, the boiling point of the organic solvent used is preferably 40 ° C. or higher and 140 ° C. or lower in order to easily adjust the boiling point of the final paint.

(Antireflection film)
Next, the antireflection film of the present invention will be described.

The antireflection film according to the present invention is an antireflection film for an optical element that contains at least an epoxy resin, a colorant, and fine particles, and the film elastic modulus of the fine particles represented by the following formula (1) ( Ef) is 0.01 GPa to 7 GPa, the average particle diameter of the fine particles is 50 nm to 200 nm, and the content of the fine particles is 7 mass% to 25 mass%.
Formula (1) Ef = (Ec−EmVm) / Vf
(In the formula, Ef is the film elastic modulus (GPa) of fine particles, Ec is the film elastic modulus (GPa) of a composite material composed of 20 parts by mass of fine particles and 80 parts by mass of epoxy resin, and Em is the film elastic modulus (GPa) of a single epoxy resin. Vm represents the volume ratio of the epoxy resin, and Vf represents the volume ratio of the fine particles.)

  The antireflection film of the present invention is composed of a composition obtained by removing the solvent from the composition of the antireflection paint described above.

  Therefore, the antireflection film of the present invention contains at least an epoxy resin, a colorant, fine particles, second fine particles, and other components. Each component contained in the antireflection film is the same as each component except for the solvent contained in the above-described antireflection paint, but the content of each component is different.

  The content of each component of the antireflection film will be described below.

  The content of the epoxy resin contained in the antireflection film of the present invention is desirably 5% by mass or more and 40% by mass or less, and preferably 10% by mass or more and 30% by mass or less.

  The content of fine particles having a film elastic modulus (Ef) of 0.01 GPa or more and 7 GPa or less contained in the antireflection film of the present invention is 7% by mass or more and 25% by mass or less, preferably 10% by mass or more and 20% by mass or less. When the content of the fine particles of the present invention is less than 7% by mass, the generation of bubbles cannot be suppressed. On the other hand, if the content of the fine particles exceeds 25% by mass, the environmental durability is low and film cracking occurs.

  The content of the colorant contained in the antireflection film of the present invention is 5% by mass to 35% by mass, preferably 10% by mass to 30% by mass.

  The content of the second fine particles contained in the antireflection film of the present invention is 5% by mass to 35% by mass, preferably 10% by mass to 15% by mass. When the content of the second fine particles is less than 5% by mass, the increase in the refractive index of the formed thin film is reduced, so that the internal reflection is increased. On the other hand, when the content of the second fine particles exceeds 35% by mass, the adhesion and durability of the coating film are lowered, which is not preferable.

  The thickness of the antireflection film of the present invention is not particularly limited, but is 0.5 μm to 100 μm, preferably 1 μm to 50 μm.

  The antireflection film of the present invention is characterized by containing, in particular, fine particles having a film elastic modulus of 0.01 GPa to 7 GPa and an average particle diameter of 50 nm to 200 nm in a range of 7% by mass to 25% by mass. Is. This feature brings about the effect of suppressing bubbles that cause poor appearance when forming an antireflection film for an optical element and preventing film cracking.

(Optical element)
The optical element of the present invention is an optical element having an antireflection film outside the optically effective surface of the optical member, wherein the antireflection film is the above-described antireflection film of the present invention.

  The optical element of the present invention can be used as an element constituting an optical apparatus such as a lens, a prism, a reflecting mirror, or a diffraction grating. For example, it can be used as an optical element used in any one of a camera, binoculars, a microscope, and a semiconductor exposure apparatus, in which a light shielding film is formed outside the optically effective surface.

  As an application method of the anti-reflection paint to the outside of the optical effective surface of the optical element as a substrate, depending on the desired application shape, dip method, spin coating method, slit coating method, electrostatic coating method, brushing, Various known methods such as application using an application jig such as a sponge or bar coater can be selected.

  As a drying process and a baking process of the antireflection coating after application, various processes can be selected within a range satisfying desired characteristics and according to the type and amount of the selected curing agent.

  The drying temperature is from room temperature to 100 ° C., more preferably from 40 ° C. to 80 ° C., still more preferably from 40 ° C. to 60 ° C. The drying time can be a time of 10 minutes to 24 hours, more preferably 30 minutes to 24 hours, and still more preferably 1 hour to 24 hours.

  The firing temperature is 40 ° C. or higher and 300 ° C. or lower, more preferably 40 ° C. or higher and 250 ° C. or lower, and still more preferably 40 ° C. or higher and 200 ° C. or lower. The firing time can be 10 minutes to 10 hours, more preferably 10 minutes to 6 hours.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. The present invention is not limited to these examples. In addition, evaluation of the bubble in the Example and comparative example of this invention, and the film crack evaluation under environmental durability were performed with the following method.

  (1) The average particle size of the fine particles was measured using a particle size distribution / zeta potential measuring device (DT1200). The average particle diameter of the fine particles indicates a value measured by particle size distribution measurement.

  (2) The film elastic modulus (Ef) of the fine particles was measured using a dynamic viscoelasticity tester (Rheogel-E4000).

(3) Evaluation of bubbles The film thickness after firing on one surface of a flat glass of a glass material S-LAH65 [product name] (manufactured by OHARA) whose base surface was treated with a # 120 count as a substrate for an evaluation sample An antireflection paint was applied so as to be 5 μm, dried at room temperature for 1 hour, and then baked at 200 ° C. for 2 hours to form an antireflection film. The sample on which the antireflection film was formed was observed from the mirror surface side using an optical microscope, and the number of bubbles having a maximum diameter of 1 μm or more per 1 cm ² was counted.

(4) Evaluation of film crack under environmental durability Evaluation of film crack under environmental durability of the obtained antireflection film was performed by the following method.

  As a substrate for an evaluation sample, the surface of the glass S-LAH65 [product name] (manufactured by OHARA) with a rough surface treated with a # 120 count is applied to one surface of the flat glass so that the film thickness after firing is 5 μm. An antireflection coating was applied, dried at room temperature for 1 hour, and then baked at 200 ° C. for 2 hours to form an antireflection film.

  Thereafter, the flat glass on which the antireflection film was formed was exposed to an atmosphere at a temperature of 85 ° C. and a humidity of 95% for 6 hours, and the occurrence of film cracking was observed from the interface between the glass and the antireflection film with a microscope and visually. In Table 4, the evaluation of film cracking is as follows: ◯ indicates that there is no film cracking, △ indicates that there are minute cracks that can be visually observed, but does not adversely affect the appearance of the interface between the glass and the antireflection film, and × indicates that Film cracks can be observed, and the appearance of the interface between the glass and the light-shielding film is markedly deteriorated.

  Moreover, the fracture toughness value of the obtained antireflection film was measured with a micro Vickers hardness meter (HMV-G).

Example 1
2.80 g of acrylic fine particle acreset BP [product name] (manufactured by Nippon Shokubai Co., Ltd.) having a membrane elastic modulus of 3.0 GPa in a stirring vessel, 7 g of epoxy resin jER828 [product name] (manufactured by Mitsubishi Chemical Corporation) , Titania dispersion ND139 [product name] (manufactured by Teika, titania concentration 25 mass% PGME dispersion, average primary particle size 15 nm) 40 g, dye (1) VALIFAST-BLACK 3810 [product name] (manufactured by Orient Chemical) 2 g, dye (2) VALIFAST-RED3320 [product name] (manufactured by Orient Chemical Co., Ltd.) 3.0 g, dye (3) VALIFAST-YELLOW 3108 [product name] (manufactured by Orient Chemical Co., Ltd.) 1.2 g, dye (4) VALIFAST- BLUE2620 [Product name] (Orient Chemical Co., Ltd.) 3.8 g, silane coupling agent KB 403 [product name] (manufactured by Shin-Etsu Silicone) 6.5 g, fungicide Sintol M-100 [product name] (manufactured by Sumika Enviro Science) 0.5 g, propylene glycol monomethyl ether (PGME) (Kishida Chemical Co., Ltd.) 24 g), and stirred with a planetary rotary stirrer HM-500 [product name] (manufactured by Keyence Corporation) for 20 minutes. 0.1 g of epoxy resin curing agent EH-6019 [product name] (manufactured by ADEKA) was added to 9 g of the obtained antireflection coating, and the mixture was stirred for 3 minutes with a planetary rotating stirrer HM-500 [product name] (manufactured by Keyence). .

  The obtained anti-reflection coating was formed on the rough surface of the flat glass with a spin coater so that the film thickness after firing was 5 μm, dried at room temperature for 1 hour, and then at 200 ° C. for 2 hours in a constant temperature oven. Baked. Since components other than the solvent in the antireflection coating have the composition of the antireflection film, the concentration of the acrylic fine particles in the antireflection film at this time was 7.6% by mass. Moreover, the average particle diameter was 100 nm from the result of the particle size distribution measurement. Table 1 shows the obtained antireflection paint and antireflection film, and Table 4 shows the evaluation results of bubbles in the antireflection film and the evaluation results of film cracking under environmental durability.

(Example 2)
4.15 g of acrylic fine particle acreset BP [product name] (manufactured by Nippon Shokubai Co., Ltd.) with a membrane elastic modulus of 3.0 GPa in a stirring vessel, 7 g of epoxy resin jER828 [product name] (manufactured by Mitsubishi Chemical Corporation) , Titania dispersion ND139 [product name] (manufactured by Teika, titania concentration 25 mass% PGME dispersion, average primary particle size 15 nm) 40 g, dye (1) VALIFAST-BLACK 3810 [product name] (manufactured by Orient Chemical) 2 g, dye (2) VALIFAST-RED3320 [product name] (manufactured by Orient Chemical Co., Ltd.) 3.0 g, dye (3) VALIFAST-YELLOW 3108 [product name] (manufactured by Orient Chemical Co., Ltd.) 1.2 g, dye (4) VALIFAST- BLUE2620 [Product name] (Orient Chemical Co., Ltd.) 3.8 g, silane coupling agent KB 6.3 [Product name] (Shin-Etsu Silicone Co., Ltd.) 6.5g, Antifungal Sintor M-100 [Product Name] (Suika Enviro Science Co., Ltd.) 0.5g, PGME (Kishida Chemical Co., Ltd.) 24g The mixture was stirred for 20 minutes with a planetary rotary stirrer HM-500 [product name] (manufactured by Keyence Corporation). 0.1 g of epoxy resin curing agent EH-6019 [product name] (manufactured by ADEKA) was added to 9 g of the obtained antireflection coating, and the mixture was stirred for 3 minutes with a planetary rotating stirrer HM-500 [product name] (manufactured by Keyence). .

  The obtained anti-reflection coating was formed on the rough surface of the flat glass with a spin coater so that the film thickness after firing was 5 μm, dried at room temperature for 1 hour, and then at 200 ° C. for 2 hours in a constant temperature oven. Baked. At this time, the concentration of the acrylic fine particles in the antireflection film was 10% by mass, and the average particle size was 100 nm. Table 1 shows the obtained antireflection paint and antireflection film, and Table 4 shows the evaluation results of bubbles in the antireflection film and the evaluation results of film cracking under environmental durability.

(Example 3)
In a stirring vessel, 12.45 g of acrylic fine particle acreset BP [product name] (manufactured by Nippon Shokubai Co., Ltd.) whose membrane elastic modulus is 3.0 GPa, 7 g of epoxy resin jER828 [product name] (manufactured by Mitsubishi Chemical Corporation) , Titania dispersion ND139 [product name] (manufactured by Teika, titania concentration 25 mass% PGME dispersion, average primary particle size 15 nm) 40 g, dye (1) VALIFAST-BLACK 3810 [product name] (manufactured by Orient Chemical) 2 g, dye (2) VALIFAST-RED3320 [product name] (manufactured by Orient Chemical Co., Ltd.) 3.0 g, dye (3) VALIFAST-YELLOW 3108 [product name] (manufactured by Orient Chemical Co., Ltd.) 1.2 g, dye (4) VALIFAST- BLUE 2620 [product name] (made by Orient Chemical Co., Ltd.) 3.8 g, silane coupling agent K M403 [product name] (manufactured by Shin-Etsu Silicone) 6.5g, fungicide Sintor M-100 [product name] (manufactured by Sumika Enviro Science) 0.5g, PGME (manufactured by Kishida Chemical) 24g The mixture was stirred for 20 minutes with a planetary rotary stirrer HM-500 [product name] (manufactured by Keyence Corporation). 0.1 g of epoxy resin curing agent EH-6019 [product name] (manufactured by ADEKA) was added to 9 g of the obtained antireflection coating, and the mixture was stirred for 3 minutes with a planetary rotating stirrer HM-500 [product name] (manufactured by Keyence). .

  The obtained anti-reflection coating was formed on the rough surface of the flat glass with a spin coater so that the film thickness after firing was 5 μm, dried at room temperature for 1 hour, and then at 200 ° C. for 2 hours in a constant temperature oven. Baked. At this time, the concentration of the acrylic fine particles in the antireflection film was 25% by mass, and the average particle size was 100 nm. Table 1 shows the obtained antireflection paint and antireflection film, and Table 4 shows the evaluation results of bubbles in the antireflection film and the evaluation results of film cracking under environmental durability.

Example 4
In a stirring vessel, 4.15 g of rubber-based fine particles having a film elastic modulus of 0.01 GPa, 7 g of epoxy resin jER828 [product name] (manufactured by Mitsubishi Chemical), titania dispersion ND139 [product name] (manufactured by Teika) , Titania concentration 25 mass% PGME dispersion, average primary particle size 15 nm) 40 g, dye (1) VALIFAST-BLACK3810 [product name] (product of Orient Chemical) 1.2 g, dye (2) VALIFAST-RED3320 [product name] (Orient Chemical Co., Ltd.) 3.0 g, Dye (3) VALIFAST-YELLOW 3108 [Product Name] (Orient Chemical Co., Ltd.) 1.2 g, Dye (4) VALIFAST-BLUE 2620 [Product Name] (Orient Chemical Co., Ltd.) 8 g, silane coupling agent KBM403 [product name] (manufactured by Shin-Etsu Silicone) 6. g, 0.5 g of the fungicide Sintol M-100 [product name] (manufactured by Sumika Enviro Science Co., Ltd.) and 24 g of PGME (manufactured by Kishida Chemical Co., Ltd.), and planetary rotary stirrer HM-500 [product name] ( (Made by Keyence) for 20 minutes. 0.1 g of epoxy resin curing agent EH-6019 [product name] (manufactured by ADEKA) was added to 9 g of the obtained antireflection coating, and the mixture was stirred for 3 minutes with a planetary rotating stirrer HM-500 [product name] (manufactured by Keyence). .

  The obtained anti-reflection coating was formed on the rough surface of the flat glass with a spin coater so that the film thickness after firing was 5 μm, dried at room temperature for 1 hour, and then at 200 ° C. for 2 hours in a constant temperature oven. Baked. At this time, the concentration of the rubber-based fine particles in the antireflection film was 10% by mass, and the average particle size was 100 nm. Table 2 shows the obtained antireflection paint and antireflection film, and Table 4 shows the evaluation results of bubbles in the antireflection film and the evaluation results of film cracking under environmental durability.

(Example 5)
In a stirring vessel, 4.15 g of polystyrene-based fine particles IMMUTEXI [product name] (manufactured by JSR) having a membrane elastic modulus of 3.5 GPa, 7 g of epoxy resin jER828 [product name] (manufactured by Mitsubishi Chemical), titania dispersion Liquid ND139 [product name] (manufactured by Teica, titania concentration 25 mass% PGME dispersion, average primary particle size 15 nm) 40 g, dye (1) VALIFAST-BLACK3810 [product name] (manufactured by Orient Chemical) 1.2 g, dye (2) VALIFAST-RED3320 [product name] (manufactured by Orient Chemical Co., Ltd.) 3.0 g, dye (3) VALIFAST-YELLOW3108 [product name] (manufactured by Orient Chemical Co., Ltd.) 1.2 g, dye (4) VALIFAST-BLUE2620 [product] Name] (Orient Chemical Co., Ltd.) 3.8 g, silane coupling agent K M403 [product name] (manufactured by Shin-Etsu Silicone) 6.5g, fungicide Sintor M-100 [product name] (manufactured by Sumika Enviro Science) 0.5g, PGME (manufactured by Kishida Chemical) 24g The mixture was stirred for 20 minutes with a planetary rotary stirrer HM-500 [product name] (manufactured by Keyence Corporation). 0.1 g of epoxy resin curing agent EH-6019 [product name] (manufactured by ADEKA) was added to 9 g of the obtained antireflection coating, and the mixture was stirred for 3 minutes with a planetary rotating stirrer HM-500 [product name] (manufactured by Keyence). .

  The obtained anti-reflection coating was formed on the rough surface of the flat glass with a spin coater so that the film thickness after firing was 5 μm, dried at room temperature for 1 hour, and then at 200 ° C. for 2 hours in a constant temperature oven. Baked. At this time, the concentration of the polystyrene fine particles in the antireflection film was 10% by mass, and the average particle size was 50 nm. Table 2 shows the obtained antireflection paint and antireflection film, and Table 4 shows the evaluation results of bubbles in the antireflection film and the evaluation results of film cracking under environmental durability.

(Example 6)
In a stirring vessel, 4.15 g of polyamideimide-based fine particle Trepearl PPS (product name) (manufactured by Toray Industries, Inc.) having a modulus of fine particles of 7.0 GPa, 7 g of epoxy resin jER828 [product name] (manufactured by Mitsubishi Chemical Corporation), titania Dispersion ND139 [product name] (manufactured by Teika, titania concentration 25 mass% PGME dispersion, average primary particle size 15 nm) 40 g, dye (1) VALIFAST-BLACK3810 [product name] (product of Orient Chemical Co.) 1.2 g, Dye (2) VALIFAST-RED3320 [Product Name] (made by Orient Chemical Co., Ltd.) 3.0 g, Dye (3) VALIFAST-YELLOW 3108 [Product Name] (made by Orient Chemical Co., Ltd.) 1.2 g, Dye (4) VALIFAST-BLUE2620 [ Product name] (Orient Chemical Co., Ltd.) 3.8 g, silane coupling agent K M403 [product name] (manufactured by Shin-Etsu Silicone) 6.5g, fungicide Sintor M-100 [product name] (manufactured by Sumika Enviro Science) 0.5g, PGME (manufactured by Kishida Chemical) 24g The mixture was stirred for 20 minutes with a planetary rotary stirrer HM-500 [product name] (manufactured by Keyence Corporation). 0.1 g of epoxy resin curing agent EH-6019 [product name] (manufactured by ADEKA) was added to 9 g of the obtained antireflection coating, and the mixture was stirred for 3 minutes with a planetary rotating stirrer HM-500 [product name] (manufactured by Keyence). .

  The obtained anti-reflection coating was formed on the rough surface of the flat glass with a spin coater so that the film thickness after firing was 5 μm, dried at room temperature for 1 hour, and then at 200 ° C. for 2 hours in a constant temperature oven. Baked. At this time, the concentration of the polyamideimide fine particles in the antireflection film was 10% by mass, and the average particle size was 200 nm. Table 2 shows the obtained antireflection paint and antireflection film, and Table 4 shows the evaluation results of bubbles in the antireflection film and the evaluation results of film cracking under environmental durability.

(Comparative Example 1)
In a stirring vessel, 4.15 g of silica fine particle Aeosil R972 [product name] (manufactured by Nippon Aerosil Co., Ltd.) with a membrane elastic modulus of 73 GPa, 7 g of epoxy resin jER828 [product name] (manufactured by Mitsubishi Chemical Corporation), titania dispersion ND139 [product name] (manufactured by Teica, titania concentration 25% by mass PGME dispersion, average primary particle size 15 nm) 40 g, dye (1) VALIFAST-BLACK3810 [product name] (product of Orient Chemical) 1.2 g, dye ( 2) VALIFAST-RED3320 [product name] (made by Orient Chemical Co., Ltd.) 3.0 g, dye (3) VALIFAST-YELLOW3108 [product name] (made by Orient Chemical Co., Ltd.) 1.2 g, dye (4) VALIFAST-BLUE2620 [product name] ] (Orient Chemical Co., Ltd.) 3.8g, silane coupling agent K M403 [product name] (manufactured by Shin-Etsu Silicone) 6.5g, fungicide Sintor M-100 [product name] (manufactured by Sumika Enviro Science) 0.5g, PGME (manufactured by Kishida Chemical) 24g The mixture was stirred for 20 minutes with a planetary rotary stirrer HM-500 [product name] (manufactured by Keyence Corporation). 0.1 g of epoxy resin curing agent EH-6019 [product name] (manufactured by ADEKA) was added to 9 g of the obtained antireflection coating, and the mixture was stirred for 3 minutes with a planetary rotating stirrer HM-500 [product name] (manufactured by Keyence). .

  The obtained anti-reflection coating was formed on the rough surface of the flat glass with a spin coater so that the film thickness after firing was 5 μm, dried at room temperature for 1 hour, and then at 200 ° C. for 2 hours in a constant temperature oven. Baked. At this time, the concentration of the silica fine particles in the antireflection film was 10% by mass, and the average particle size was 50 nm. Table 3 shows the obtained antireflection paint and antireflection film, and Table 4 shows the evaluation results of bubbles in the antireflection film and the evaluation results of film cracking under environmental durability.

(Comparative Example 2)
In a stirring vessel, 16 g of acrylic fine particle acreset BPA [product name] (manufactured by Nippon Shokubai Co., Ltd.) whose elastic modulus is 3.0 GPa, epoxy resin jER828 [product name] (manufactured by Mitsubishi Chemical Corporation) 7 g, titania dispersion Liquid ND139 [product name] (manufactured by Teica, titania concentration 25 mass% PGME dispersion, average primary particle size 15 nm) 40 g, dye VALIFAST-BLACK3810 [product name] (product of Orient Chemical Co.) 1.2 g, dye VALIFAST-RED3320 [Product Name] (Orient Chemical Co., Ltd.) 3.0 g, Dye VALIFAST-YELLOW 3108 [Product Name] (Orient Chemical Co., Ltd.) 1.2 g, Dye VALIFAST-BLUE 2620 [Product Name] (Orient Chemical Co., Ltd.) 3.8 g, Silane coupling agent KBM403 [product name] (Shin-Etsu Siri 6.5 g, fungicide Sintol M-100 [product name] (manufactured by Sumika Enviro Science Co., Ltd.) 0.5 g, PGME (manufactured by Kishida Chemical Co., Ltd.) 24 g, and planetary rotating stirrer HM The mixture was stirred at −500 [product name] (manufactured by Keyence Corporation) for 20 minutes. 0.1 g of epoxy resin curing agent EH-6019 [product name] (manufactured by ADEKA) was added to 9 g of the obtained antireflection coating, and the mixture was stirred for 3 minutes with a planetary rotating stirrer HM-500 [product name] (manufactured by Keyence). .

  The obtained anti-reflective coating was formed on the rough surface of the above flat glass with a spin coater so that the film thickness after firing was 5 μm, dried at room temperature for 1 hour, and then fired at 200 ° C. for 2 hours in a constant temperature oven. did. At this time, the concentration of the acrylic fine particles in the antireflection film was 30% by mass, and the average particle size was 500 nm. Table 3 shows the obtained antireflection paint and antireflection film, and Table 4 shows the evaluation results of bubbles in the antireflection film and the evaluation results of film cracking under environmental durability.

(Comparative Example 3)
In a stirring vessel, 1.95 g of polyamideimide fine particle trepal PPS [product name] (manufactured by Toray Industries, Inc.) whose elastic modulus of the fine particles was 7.0 GPa, 7 g of epoxy resin jER828 [product name] (manufactured by Mitsubishi Chemical Corporation), Titania dispersion ND139 [product name] (manufactured by Teica, titania concentration 25 mass% PGME dispersion, average primary particle size 15 nm) 40 g, dye (1) VALIFAST-BLACK3810 [product name] (product of Orient Chemical Co.) 1.2 g , Dye (2) VALIFAST-RED3320 [product name] (made by Orient Chemical Co., Ltd.) 3.0 g, dye (3) VALIFAST-YELLOW3108 [product name] (made by Orient Chemical Co., Ltd.) 1.2 g, dye (4) VALIFAST-BLUE2620 [Product Name] (Orient Chemical Co., Ltd.) 3.8 g, silane coupling agent 6.5 g of BM403 [product name] (manufactured by Shin-Etsu Silicone), 0.5 g of the fungicide Sintor M-100 [product name] (manufactured by Sumika Enviro Science), and 24 g of PGME (manufactured by Kishida Chemical Co., Ltd.) The mixture was stirred for 20 minutes with a planetary rotary stirrer HM-500 [product name] (manufactured by Keyence Corporation). 0.1 g of epoxy resin curing agent EH-6019 [product name] (manufactured by ADEKA) was added to 9 g of the obtained antireflection coating, and the mixture was stirred for 3 minutes with a planetary rotating stirrer HM-500 [product name] (manufactured by Keyence). .

  The obtained anti-reflection coating was formed on the rough surface of the flat glass with a spin coater so that the film thickness after firing was 5 μm, dried at room temperature for 1 hour, and then at 200 ° C. for 2 hours in a constant temperature oven. Baked. At this time, the concentration of the polyamideimide fine particles in the antireflection film was 5% by mass, and the average particle size was 200 nm. Table 3 shows the obtained antireflection paint and antireflection film, and Table 4 shows the evaluation results of bubbles in the antireflection film and the evaluation results of film cracking under environmental durability.

(Comparative Example 4)
In a stirring vessel, 16 g of polyamideimide fine particle trepal PPS [product name] (manufactured by Toray Industries, Inc.) having an elastic modulus of 7.0 GPa, 7 g of epoxy resin jER828 [product name] (manufactured by Mitsubishi Chemical Corporation), titania dispersion ND139 [product name] (manufactured by Teica, titania concentration 25% by mass PGME dispersion, average primary particle size 15 nm) 40 g, dye (1) VALIFAST-BLACK3810 [product name] (product of Orient Chemical) 1.2 g, dye ( 2) VALIFAST-RED3320 [product name] (made by Orient Chemical Co., Ltd.) 3.0 g, dye (3) VALIFAST-YELLOW3108 [product name] (made by Orient Chemical Co., Ltd.) 1.2 g, dye (4) VALIFAST-BLUE2620 [product name] ] (Orient Chemical Co., Ltd.) 3.8g, silane coupling agent KBM 03 [Product name] (Shin-Etsu Silicone) 6.5g, Antifungal Sintor M-100 [Product name] (Suika Enviro Science) 0.5g, PGME (Kishida Chemical) 24g The mixture was stirred for 20 minutes with a planetary rotary stirrer HM-500 [product name] (manufactured by Keyence Corporation). 0.1 g of epoxy resin curing agent EH-6019 [product name] (manufactured by ADEKA) was added to 9 g of the obtained antireflection coating, and the mixture was stirred for 3 minutes with a planetary rotating stirrer HM-500 [product name] (manufactured by Keyence). .

  The obtained anti-reflection coating was formed on the rough surface of the flat glass with a spin coater so that the film thickness after firing was 5 μm, dried at room temperature for 1 hour, and then at 200 ° C. for 2 hours in a constant temperature oven. Baked. At this time, the concentration of the polyamideimide fine particles in the antireflection film was 30% by mass, and the average particle size was 200 nm. Table 3 shows the obtained antireflection paint and antireflection film, and Table 4 shows the evaluation results of bubbles in the antireflection film and the evaluation results of film cracking under environmental durability.

(Note 1) The composition of the antireflection film is a composition of components obtained by removing propylene glycol monomethyl ether as a solvent and propylene glycol monomethyl ether contained in the second fine particles from the composition of the antireflection coating. The content of fine particles in the antireflection film is a value obtained from the composition of the antireflection film.

  In Comparative Example 2, although the generation of bubbles was small, the average particle size of the fine particles was large, so that scattering occurred, and the appearance of the antireflection film was entirely white and the quality was lowered. Film cracking occurred when the fracture toughness value was 1.30 MPa · m1 / 2 or less.

  From all the examples and comparative example 4, when 7 mass% or more of the fine particles having an elastic modulus of 0.01 GPa or more and 7 GPa or less are contained in the antireflection film for optical elements, the generation of bubbles can be suppressed, and the antireflection with high appearance quality can be achieved. It is shown that a film is obtained. Further, from all the Examples and Comparative Example 3, if the antireflection film for optical elements contains fine particles having a film elastic modulus of 0.01 GPa or more and 7 GPa or less in an amount of 25% by mass or less, film cracking under environmental durability is suppressed. It is shown that an antireflection film having a sufficient film quality for practical use and an optical element comprising the same can be obtained.

  Since the antireflection film and antireflection film of the present invention can suppress the generation of bubbles at the interface of the antireflection film for optical elements and prevent film cracking, the antireflection film and antireflection film of the present invention can be used for optical elements and light shielding members. it can.

DESCRIPTION OF SYMBOLS 1 Antireflection film 2 Lens 3 Light which does not hit outer peripheral part (incident light)
4 Transmitted light 5 Light hitting the outer periphery (incident light)
6 Inner reflection light 7 Outer peripheral part 8 Optical effective surface 9 Out of optical effective surface 11 Lens 12 Coating film 13 Bubble 14 Large bubble

Claims (15)

An antireflection paint for an optical element containing at least an epoxy resin, a colorant, fine particles, and a solvent, and a film elastic modulus (Ef) represented by the following formula (1) of the fine particles is 0.01 GPa An antireflective coating composition having a particle size of 7 GPa or less, an average particle diameter of the fine particles of 50 nm to 200 nm, and a content of the fine particles of 3% to 14% by mass.
Formula (1) Ef = (Ec−EmVm) / Vf
(In the formula, Ef is the film elastic modulus (GPa) of fine particles, Ec is the film elastic modulus (GPa) of a composite material composed of 20 parts by mass of fine particles and 80 parts by mass of epoxy resin, and Em is the film elastic modulus (GPa) of a single epoxy resin. Vm represents the volume ratio of the epoxy resin, and Vf represents the volume ratio of the fine particles.)   The antireflection paint according to claim 1, wherein the fine particles are organic fine particles.   The antireflection paint according to claim 1, wherein the colorant is a dye.   The antireflection paint according to any one of claims 1 to 3, wherein the antireflection paint further contains second fine particles made of an inorganic compound.   The antireflection paint according to claim 4, wherein the second fine particles have a refractive index of 2.2 or more.   6. The antireflection paint according to claim 4, wherein the second fine particles contain titanium oxide.   The antireflection paint according to any one of claims 4 to 6, wherein an average particle size of the second fine particles is 10 nm or more and 100 nm or less. An antireflection film for an optical element containing at least an epoxy resin, a colorant, and fine particles, and a film elastic modulus (Ef) represented by the following formula (1) of the fine particles is 0.01 GPa to 7 GPa And an average particle diameter of the fine particles is 50 nm or more and 200 nm or less, and a content of the fine particles is 7 mass% or more and 25 mass% or less.
Formula (1) Ef = (Ec−EmVm) / Vf
(In the formula, Ef is the film elastic modulus (GPa) of fine particles, Ec is the film elastic modulus (GPa) of a composite material composed of 20 parts by mass of fine particles and 80 parts by mass of epoxy resin, and Em is the film elastic modulus (GPa) of a single epoxy resin. Vm represents the volume ratio of the epoxy resin, and Vf represents the volume ratio of the fine particles.)   The antireflection film according to claim 8, wherein the fine particles are organic fine particles.   The antireflection film according to claim 8, wherein the colorant is a dye.   The antireflection film according to any one of claims 8 to 10, wherein the antireflection film further contains second fine particles made of an inorganic compound.   The antireflection film according to claim 11, wherein the second fine particles have a refractive index of 2.2 or more.   The antireflection film according to claim 11, wherein the second fine particles contain titanium oxide.   The antireflection film according to any one of claims 11 to 13, wherein an average particle diameter of the second fine particles is 10 nm or more and 100 nm or less.   An optical element having an antireflection film outside the optically effective surface of the optical member, wherein the antireflection film is the antireflection film according to any one of claims 8 to 14.

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