JP2021059744A - Brittle material particulate, method of manufacturing brittle material film, and composite structure - Google Patents

Abstract

To provide a brittle material particulate capable of forming a transparent thick brittle material film even on a resin base material without requiring a ground layer, to provide a method of manufacturing a brittle material film using the brittle material particle, and to provide a composite structure having the brittle material film by the manufacturing method.SOLUTION: There is provided a brittle material particulate for forming a brittle material film on a base material by an aerosol deposition method (AD method), the brittle material particulate (except glass) including one or more kinds of materials selected from a group of compounds of a boron atom, a metal atom, and an oxygen atom, and mixtures of aluminum oxide and boron oxide. A method of manufacturing the brittle material film includes a step of forming the brittle material film by applying the brittle material particle onto the base material by the AD method. A composite structure has, on the base material, the brittle material film formed by the method of manufacturing the brittle material film.SELECTED DRAWING: None

Description

The present invention relates to fine particles of brittle material, a method for producing a film of brittle material, and a composite structure.

Conventionally, as a method of colliding a brittle material with a base material to form a brittle material structure on the surface of the base material, an aerosol gas deposit method (hereinafter, may be referred to as an AD method) is known (for example, Patent Document 1). reference). It is said that it is more difficult for the AD method to form a brittle material structure on the surface of a resin base material than a metal base material or a glass base material (see, for example, Patent Document 2).

International Publication No. 01/27348 Japanese Unexamined Patent Publication No. 2003-034003

In order to form a brittle material structure on the surface of the resin base material, for example, in Patent Document 2, a base layer made of a hard material in which a part of the brittle material structure bites into the surface of the resin base material is formed, and many base layers are formed on the base layer. The resin and the brittle material are characterized in that a brittle material structure is formed which is crystalline and has substantially no crystal orientation and further has substantially no grain boundary layer composed of a glass layer at the interface between the crystals. We are proposing a composite structure.

However, in the composite structure of Patent Document 2, it is necessary to form a specific base layer on the surface of the resin base material while heating the resin base material in a softened state. If the base layer is not formed, the structure is made of aluminum oxide. The film thickness is 9 μm, and there is a problem that the thickness cannot be increased.

Further, there are known brittle materials such as lithium manganate (LMO) and lead zirconate titanate (PZT) that can form a brittle material film having a thickness of 10 μm or more on a resin substrate. Such brittleness The brittle material film (brittle material structure) formed from the material is colored opaque and not transparent.

As described above, there has been no brittle material capable of forming a transparent brittle material film having a thick film thickness (for example, 10 μm or more) on the resin base material without providing the base layer.

Therefore, an object of the present invention is to provide brittle material fine particles capable of forming a transparent, thick, brittle material film on a resin base material without a base layer.

Another object of the present invention is to provide a method for producing a brittle material film using the above-mentioned brittle material fine particles.

Another object of the present invention is to provide a composite structure having a brittle material film according to the method for producing a brittle material film.

The brittle material fine particles according to the present invention are
Brittle material fine particles for forming a brittle material film on a substrate by the aerosol deposition method (AD method), from a compound of a boron atom, a metal atom and an oxygen atom, and a mixture of aluminum oxide and boron oxide. It is a brittle material fine particle (excluding glass) containing one or more selected from the above group. According to the brittle material fine particles according to the present invention, a transparent, thick, brittle material film can be formed on a resin base material even without a base layer.

In one embodiment of the brittle material fine particles according to the present invention, the metal atom is one or more selected from the group consisting of Zn, Mg and Al.

The method for producing a brittle material film according to the present invention includes a step of applying the above-mentioned brittle material fine particles onto a substrate by an aerosol deposition method (AD method) to form a brittle material film. It is a manufacturing method. According to the method for producing a brittle material film according to the present invention, a transparent, thick, brittle material film can be formed on a resin base material without a base layer.

The composite structure according to the present invention is a composite structure having a brittle material film according to the above-mentioned method for producing a brittle material film on a base material. According to the composite structure according to the present invention, it is also possible to have a transparent, thick, brittle material film without a base layer on the resin base material.

According to the present invention, it is possible to provide brittle material fine particles capable of forming a transparent, thick, brittle material film on a resin base material without a base layer. Further, according to the present invention, it is possible to provide a method for producing a brittle material film using the above-mentioned brittle material fine particles. Further, according to the present invention, it is possible to provide a composite structure having a brittle material film according to the method for producing a brittle material film.

Hereinafter, embodiments of the present invention will be described. These descriptions are for the purpose of exemplifying the present invention and do not limit the present invention in any way.

In the present invention, the term "compound" means a substance containing a solid solution and a mixed crystal in addition to a pure substance consisting of atoms of two or more kinds of elements, unless otherwise specified. Therefore, the "compound" in the present invention does not include a solid solution or a simple mixture that is not a mixed crystal. In the present invention, the "solid solution" means a state in which two or more substances existing as independent elements or compounds are solid and dissolved in each other. In the present invention, "mixed crystal" means a crystal formed by mixing two or more substances having different chemical components and having a crystal structure with each other.

In the present invention, two or more embodiments can be arbitrarily combined.

(Manufacturing method of brittle material film)
The method for producing a brittle material film according to the present invention includes a step of applying the brittle material fine particles according to the present invention onto a substrate by an aerosol deposition method (AD method) to form a brittle material film. This is a method for manufacturing a material film.

Hereinafter, the brittle material fine particles used in the method for producing a brittle material film according to the present invention, the brittle material film to be formed, the AD method, and the base material will be described as examples.

(Brittle material fine particles)
The brittle material fine particles according to the present invention are
Brittle material fine particles for forming a brittle material film on a substrate by the aerosol deposition method (AD method), from a compound of a boron atom, a metal atom and an oxygen atom, and a mixture of aluminum oxide and boron oxide. It is a brittle material fine particle (excluding glass) containing one or more selected from the above group.

According to the brittle material fine particles according to the present invention, a brittle material that is transparent and has a thick film thickness even on a resin substrate at a relatively low temperature (for example, 10 to 40 ° C., the same applies hereinafter) even if there is no base layer. A film can be formed. Further, conventionally, it has not been possible to form a transparent, thick, brittle material film on a resin base material at a relatively low temperature without a base layer. Therefore, according to the brittle material fine particles according to the present invention capable of forming such a brittle material film, the presence or absence of the base layer, the type of the base material, the transparency of the brittle material film, and the transparency of the brittle material film even at a relatively low temperature. The brittle material film can be formed regardless of the thickness of the brittle material film. That is, according to the brittle material fine particles according to the present invention, the brittle material film can be formed with or without the base layer, and even on the resin base material, it is on a base material other than the resin base material. Even if it can form a brittle material film, it can form a brittle material film regardless of whether it is transparent, opaque, colorless or colored, and it is brittle regardless of whether it is thick or thin. A material film can be formed.

Although it is not desired to be bound by the theory, the brittle material fine particles according to the present invention may form a transparent, thick, brittle material film on the resin base material even without the base layer. The reason for this is that the brittle material fine particles collide with the base material by the AD method, and the brittle material fine particles are shattered, and when they are deposited to form a brittle material film, the shattered brittle material fine particles are plastically deformed. It is presumed that this is because the voids between the brittle material fine particles that have been crushed and shattered by the energy of the AD method disappear. If there are voids between the brittle material fine particles constituting the brittle material film, it is presumed that light scattering occurs due to the difference in refractive index between the air in the voids and the brittle material fine particles, and the brittle material film becomes opaque. Is.

The brittle material fine particles according to the present invention are one or more selected from the group consisting of a compound of a boron atom (B), a metal atom (M) and an oxygen atom (O), and a mixture of aluminum oxide and boron oxide. Including. The brittle material fine particles may be used alone or in combination of two or more.

Examples of the metal atom (M) in the compound of the boron atom (B), the metal atom (M) and the oxygen atom (O) include sodium (Na), magnesium (Mg), indium (Al) and potassium (K). , Calcium (Ca), Scandium (Sc), Titanium (Ti), Vanadium (V), Chromium (Cr), Manganese (Mn), Iron (Fe), Cobalt (Co), Nickel (Ni), Copper (Cu) , Zinc (Zn), gallium (Ga), rubidium (Rb), strontium (Sr), zirconium (Zr), molybdenum (Mo), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag) , Cadmium (Cd), indium (In), tin (Sn), platinum (Pt), gold (Au), lead (Pb) and the like.

In one embodiment of the brittle material fine particles according to the present invention, the metal atom is one or more selected from the group consisting of Zn, Mg and Al. As a result, the transparency of the brittle material film is more excellent.

The compound of the boron atom (B), the metal atom (M), and the oxygen atom (O) contained in the brittle material fine particles may be a compound composed of at least these atoms, and is composed of only these three types of atoms. It may be a compound, or may be a compound consisting of only four types of atoms including a hydrogen atom (H) in addition to these three types of atoms.

In one embodiment of the brittle material fine particles according to the present invention, the compound is a compound of a boron atom, a metal atom, an oxygen atom and a hydrogen atom.

In one embodiment of the brittle material fine particles according to the present invention, the ratio (mol%) of the boron atom (B), the metal atom (M), the oxygen atom (O), and the hydrogen atom (H) in the compound is determined.
B = 10-50 mol%,
M = 5-30 mol%,
O = 30-70 mol%,
H = 0 to 40 mol%.

Further, the compound of the boron atom, the metal atom and the oxygen atom contained in the brittle material fine particles may be an anhydride or a hydrate.

In one embodiment of the brittle material microparticles according to the present invention, the compound is a hydrate.

In one embodiment of the brittle material fine particles according to the present invention, wherein the compound is rational formula _{2ZnO-3B 2 O 3 -3.5H 2} O, 4ZnO-B 2 O 3 -H 2 O, 2ZnO-2B 2 O 3 One or more selected from the group consisting of -3H ₂ O, 2 ZnO-3B ₂ O ₃ and 2 Zn (BO ₂ ) ₂ -3H _{2 O.}

In another embodiment of the brittle material microparticles according to the present invention, the compound is one or more selected from the group consisting of zinc borate, magnesium borate and aluminum borate.

Of the compounds of boron atom, metal atom and oxygen atom and the mixture of aluminum oxide and boron oxide contained in the brittle material fine particles, the compound is preferable because the brittle material film has higher transparency than the mixture. In one embodiment, the brittle material microparticles according to the present invention are compounds of boron atoms, metal atoms and oxygen atoms (ie, the brittle material microparticles do not contain a mixture of aluminum oxide and boron oxide).

As the compound of the boron atom, the metal atom and the oxygen atom contained in the brittle material fine particles according to the present invention, a commercially available product may be used. For example, zinc borate rational formula _{2ZnO-3B 2 O 3 -3.5H 2} O, and the like US Borax Inc. FireBrakeZB. For example, as the zinc borate of the demonstrative formula 4ZnO-B ₂ O _3- H ₂ O, FireBrake415 of US Borax Co., Ltd. and the like can be mentioned. For example, zinc borate rational formula _{2ZnO-2B 2 O 3 -3H 2} O, and the like Zibo WuweiIndustrial's Zinc borate 223B. For example, zinc borate rational formula _2ZnO-3B 2 _{O 3,} and the like FireBrake500 of US Borax Inc.. For example, magnesium borate rational formula _{2MgO-3B 2 O 3 -xH 2} O, and the like Tomita Seiyaku magnesium borate.

The mixture of aluminum oxide and boron oxide contained in the brittle material fine particles may be a mixture containing at least aluminum oxide and boron oxide, a mixture consisting only of aluminum oxide and boron oxide, or in addition to aluminum oxide and boron oxide. It may be a mixture containing one or more selected from the group consisting of aluminum hydroxide and boric acid.

Examples of the mixture of aluminum oxide and boron oxide contained in the brittle material fine particles include a mixture of aluminum oxide and boron oxide, a mixture of aluminum oxide, aluminum hydroxide and boron oxide, aluminum oxide, boron oxide and boric acid. Examples thereof include a mixture of aluminum oxide, aluminum hydroxide, boron oxide and boric acid.

As the mixture of aluminum oxide and boron oxide contained in the brittle material fine particles according to the present invention, a commercially available product may be used. For example, as a mixture of aluminum oxide, aluminum hydroxide, boron oxide, and boric acid, the trade name of Terada Yakusen Kogyo Co., Ltd. is aluminum borate (Al ₂ O _3- Al (OH) _3- B ₂ O _3- B ( OH) ₃ ) and the like can be mentioned.

The brittle material fine particles according to the present invention are not glass (fine particles of glass only). This is because the desired effect cannot be obtained even if only the glass is made into fine particles to form a brittle material film by the AD method.

The brittle material fine particles according to the present invention include, in addition to a compound of a boron atom, a metal atom and an oxygen atom, and a mixture of aluminum oxide and boron oxide, other compounds (the present invention) as long as the gist of the present invention is not deviated. It is not a "compound" of "compound" but a "compound" in a general sense. The same shall apply hereinafter). Examples of other compounds include boron oxide (B ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), glass and the like.

When the brittle material fine particles according to the present invention contain other compounds in addition to a compound of a boron atom, a metal atom and an oxygen atom, and a mixture of aluminum oxide and boron oxide, the boron atom and the metal in the brittle material fine particles The content ratio of one or more selected from the group consisting of a compound of an atom and an oxygen atom and a mixture of aluminum oxide and boron oxide is, for example, 20 to 99.9 mass with respect to the total mass of brittle material fine particles. %, Or 50-99.9% by mass. A high content ratio of a compound of a boron atom, a metal atom and an oxygen atom, and a mixture of aluminum oxide and boron oxide is preferable because the transparency of the brittle material film is improved.

The shape, particle size, particle size distribution, etc. of the brittle material fine particles according to the present invention may be appropriately adjusted and are not particularly limited. For example, the shape is preferably non-spherical. As for the particle size distribution, the number-based D50 is preferably 0.1 to 10 μm, and more preferably 0.7 to 3 μm.

Since the brittle material fine particles according to the present invention are harder than the resin base material, if a brittle material film having a sufficient thickness is formed on the surface of the resin base material, the resin base material is excellently scratch resistant. Brittleness and gas barrier properties can be imparted.

<Brittle material film>
The brittle material film is a film formed by using the above-mentioned brittle material fine particles.

The brittle material film may be transparent, opaque, thin, or thick. The brittle material film formed by using the brittle material fine particles according to the present invention can be a transparent and thick brittle material film.

To measure the transparency of the brittle material film, the surface of the brittle material film formed on the substrate is polished with a 3 μm diamond compound to remove surface scattered light, and then a haze meter product manufactured by Nippon Denshoku Kogyo Co., Ltd. This is done using the name NDH2000. The measuring method conforms to JIS K 7136, and the haze value is the ratio (percentage) of transmitted light deviated by 0.044 rad (2.5 °) or more from the incident light due to forward scattering. When the film thickness of the brittle material film is 10 μm or more, in order to eliminate the influence of the film thickness, the haze value at the location where the film thickness is 10 μm or less and the haze value at the location where the film thickness is 10 μm or more of the same sample are reduced to 10 μm. Calculate the corresponding haze value.

As described above, according to the brittle material fine particles according to the present invention, a brittle material film can be formed regardless of whether it is transparent or opaque. Therefore, the transparency of the brittle material film according to the present invention is not particularly limited, and for example, the haze value of the brittle material film may be 1 to 60. In the case of a transparent brittle material film, the haze value is preferably small. In one embodiment of the transparent brittle material film, the haze value of the brittle material film is 15 or less, 5 or less, 3 or less or 1 or less.

When the brittle material film is transparent, the surface of the object forming the brittle material film, such as the painted surface of a vehicle such as an automobile, a plastic window, or a display, is easily scratched, and the scratches impair the aesthetic appearance and visibility. In the case of an object to be used, it can be suitably used because it can impart excellent scratch resistance to the object and ensure aesthetics and visibility.

When the brittle material film is made opaque or colored, for example, a method of adding brittle materials having different refractive indexes and a method of adding a coloring pigment can be mentioned.

The film thickness of the brittle material film may be appropriately adjusted and is not particularly limited, and may be thick or thin as described above. The film thickness of the brittle material film is, for example, 1 to 30 μm. When the base material is a resin base material, the film thickness of the brittle material film is preferably 5 to 30 μm, preferably 10 to 30 μm, from the viewpoint of imparting excellent scratch resistance and gas barrier properties to the resin base material. Is more preferable.

<AD method>
Regarding the AD method, in the AD method used when forming a conventionally known brittle material film, for example, as described in Patent Document 2, conventional brittle material fine particles are ejected together with a carrier gas from an injection port of an apparatus. It is a technique of colliding with the surface of a base material to coat the surface of the base material with fine particles of brittle material, or to form a base layer made of fine particles of brittle material on the surface of the base material. On the other hand, the AD method using the brittle material fine particles according to the present invention in the method for producing a brittle material film according to the present invention has the same principle as the AD method used when forming a conventional brittle material film, and is brittle. This is a method in which the material fine particles are ejected together with the carrier gas from the injection port of the apparatus and collide with the surface of the base material to coat the surface of the base material with the brittle material fine particles. Therefore, the devices and conditions of the conventional AD method can be used. As a reference of the conventional AD method, in addition to Patent Document 2, for example, Japanese Patent Application Laid-Open No. 2003-073855, Japanese Patent Application Laid-Open No. 2006-130703, Japanese Patent Application Laid-Open No. 2012-243629, International Publication No. 2012/160979 and the like can be mentioned. Be done.

The temperature at which the brittle material fine particles are applied onto the base material by the AD method may be appropriately selected according to the type of the resin base material. When a resin base material is used as the base material, the temperature is, for example, 0 to 100 ° C, preferably 10 to 40 ° C. When a base material such as a metal base material or a glass base material other than the resin base material is used as the base material, the temperature is, for example, 0 to 200 ° C., preferably 10 to 100 ° C.

<Base material>
The base material on which the brittle material film is formed by the AD method is not particularly limited, and can be selected from known base materials. Examples of the base material include a resin base material, a glass base material, a metal base material, and the like.

As the resin base material, a known resin base material can be used. Examples of the resin base material include polycarbonate (PC), polyethylene terephthalate (PET), acrylonitrile, butadiene, styrene (ABS), polypropylene, acrylic resin, polystyrene, polyimide, and epoxy resin. Further, these resin base materials may contain additives such as pigments, coloring materials such as dyes, and functional inorganic substances.

Further, the resin base material includes a glass base material, a metal base material, and other base materials having a resin film (coating film or coating) on the surface of a base material other than the resin base material, which will be described later. This is because such a resin film is composed of a resin like a resin base material.

As the glass base material, a known glass base material can be used. Examples of the glass base material include float glass, tempered glass, heat-resistant glass, fireproof glass, design glass, colored glass, laminated glass, antique glass, retro glass, frosted glass, multilayer glass, and glass fiber.

As the metal base material, a known metal base material can be used. Examples of the metal base material include iron, stainless steel (alloy steel), aluminum, and copper.

In one embodiment, the substrate is one selected from the group consisting of resin substrates, glass substrates and metal substrates. In another embodiment, the substrate is two or more composite substrates selected from the group consisting of resin substrates, glass substrates and metal substrates.

The object (object to be coated) on which the brittle material film is formed by the AD method is not particularly limited and can be appropriately selected. Objects include, for example, displays of electronic devices such as home appliances; vehicles such as automobiles, trains, buses, and taxis (windows and painted bodies); ships; aircraft such as airplanes and helicopters (windows and painted bodies). Vending machines; Road signs; Signals; Street lights; LED, LCD, light bulb, etc. electric bulletin boards; Glasses, telescopes, cameras, video cameras (these housings and displays); Mirrors; Clothing; Footwear such as shoes; Rain gear such as umbrellas; packaging materials, etc.

In the method for producing a brittle material film according to the present invention, in addition to the step of applying the brittle material fine particles on the substrate by the AD method to form the brittle material film, other steps may be optionally included. Good. Examples of other steps include a step of pretreating the base material, a step of forming a base layer on the base material, and a step of post-treating the formed brittle material film.

(Composite structure)
The composite structure according to the present invention is a composite structure having a brittle material film according to the above-mentioned method for producing a brittle material film on a base material. Examples of the composite structure include those having a brittle material film on the above-mentioned object.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are for the purpose of exemplifying the present invention and do not limit the present invention in any way.

The details of the materials used in the examples are as follows.
Boron atoms and zinc (Zn) compounds of the atom and the oxygen atom and the hydrogen atom (hydrate of zinc borate), rational formula _{2ZnO-3B 2 O 3 -3.5H 2} O, In Table 1, zinc borate Notation: US Borax brand name FireBrakeZB
Compounds of boron atoms and magnesium (Mg) and oxygen atoms and hydrogen atoms, rational formula _{2MgO-3B 2 O 3 -xH 2} O, In Table 1, magnesium borate denoted: Tomita Pharmaceutical Co. trade name of boric acid Mixture of magnesium aluminum oxide, aluminum hydroxide, boron oxide, and boric acid: Product name of Terada Yakusen Kogyo Co., Ltd. Aluminum borate (Compound Al ₂ O _3- Al (OH) _3- B ₂ O _3- B (Differential formula Al 2 O 3-Al (OH) 3-B 2 O 3-B ( OH) ₃ )
Mixture of zinc borate and boron oxide: Mixage of zinc borate (trade name FireBrakeZB of US Borax) and boron oxide (trade name of US Borax Boric Oxide) (zinc borate: boron oxide (weight ratio) = 7: 3)
Boron Oxide (B ₂ O ₃ ): Brand name Boric Oxide of US Borax
Zinc oxide (ZnO): Reagent manufactured by Wako Junyaku Co., Ltd. Mixing of zinc oxide and boron oxide: Mixing of zinc oxide (reagent manufactured by Wako Junyaku Co., Ltd.) and boron oxide (trade name: Boric Oxide of US Borax) (zinc oxide: Zinc oxide (molar ratio) = 2: 3)

The details of the base material used in the examples are as follows.
Resin base material (polycarbonate, written as PC in Table 1): Product name of Nippon Test Panel Co., Ltd. Polycarbonate resin base material (polyethylene terephthalate, written as PET in Table 1): Product name PET of Japan Test Panel Co., Ltd.
Resin base material (glass coated with acrylic resin paint): Glass plate coated with resin paint with a film thickness of 35 μm Glass base material: Brand name of Japan Test Panel Co., Ltd. Glass metal base material: SPCC steel plate, Japan Test Panel Co., Ltd. Product name SPCC

The details of the film forming conditions by the AD method are as follows.
Gas: Dry air Gas amount: 5 L / min Temperature: Room temperature (about 25 ° C)
Film formation chamber pressure: 180 Pa
Substrate transfer speed: 30 mm / sec.
Number of film formations (number of scans): 6 to 24 times (adjusted so that the film thickness is 10 μm)

The materials shown in Table 1 were each subjected to ball milling for 10 minutes to obtain brittle material fine particles or comparative fine particles having a particle size of 0.1 to 10 μm.

(Examples 1 to 8 and Comparative Examples 1 to 3)
Using the brittle material fine particles or comparative fine particles shown in Table 1 and the base material, the brittle material fine particles were applied onto the base material by the AD method without forming a base layer to form a brittle material film. For each brittle material film, the 10 μm film forming property and the transparency of the brittle material film were evaluated as follows. The results are shown in Table 1.

<10 μm film formation property>
The case where a brittle material film having a film thickness of 10 μm or more could be formed was evaluated as ◯, and the case where it could not be formed was evaluated as x.

<Transparency of brittle material film>
The transparency of the brittle material film was measured by the method described above. Transparency was evaluated according to the following criteria. Example 8 in which a film was formed on a substrate that does not transmit light corresponds to any of ⊚, ◯, and × by visually comparing the transparency with other examples and comparative examples whose transparency has been evaluated. Was evaluated. ◎ indicates that it has the highest transparency.
⊚: Haze value 15 or less, or visually equivalent to haze value 15 or less ○: Haze value greater than 15 and equal to 60 or less, or visually greater than haze value 15 and equivalent to 60 or less ×: Haze value greater than 60 or visually equivalent to haze Equivalent to a value greater than 60

＊１：比較例１〜３の微粒子は比較微粒子である。

* 1: The fine particles of Comparative Examples 1 to 3 are comparative fine particles.

As shown in Table 1, in Examples, a transparent, thick brittle material film having a film thickness of 10 μm or more is formed on a resin base material, a metal base material, and a glass base material by the AD method even without a base layer. I was able to. However, in Comparative Example 1 using zinc oxide fine particles, it was not possible to form a brittle material film having a film thickness of 10 μm or more. Further, in Comparative Example 2 using the boron oxide fine particles, a transparent brittle material film could not be formed. Further, in Comparative Example 3 using a mixture of zinc oxide fine particles and boron oxide fine particles, the transparency of the brittle material film was insufficient.

According to the present invention, it is possible to provide brittle material fine particles capable of forming a transparent, thick, brittle material film on a resin base material without a base layer. Further, according to the present invention, it is possible to provide a method for producing a brittle material film using the above-mentioned brittle material fine particles. Further, according to the present invention, it is possible to provide a composite structure having a brittle material film according to the production method.

Claims (4)

It is a brittle material fine particle for forming a brittle material film on a substrate by an aerosol deposition method (AD method), and is composed of a compound of a boron atom, a metal atom and an oxygen atom, and a mixture of aluminum oxide and boron oxide. Brittle material fine particles (excluding glass) containing one or more selected from the group. The brittle material fine particles according to claim 1, wherein the metal atom is at least one selected from the group consisting of Zn, Mg and Al. A method for producing a brittle material film, which comprises a step of applying the brittle material fine particles according to claim 1 or 2 onto a substrate by an aerosol deposition method (AD method) to form a brittle material film. A composite structure having a brittle material film according to the method for producing a brittle material film according to claim 3 on a base material.