JP6736049B2 - Glass composite, transparent screen including the same, and image projection system including the same - Google Patents

Description

The present invention relates to a glass composite for a transparent screen, which achieves both visibility of projection light and visibility of transmitted light by anisotropically scattering and reflecting projection light, and further has scratch resistance, abrasion resistance and long-term stability. In particular, the present invention relates to a screen for a projector, and a video projection system including the screen, which can improve the antifouling property and the antifouling property.

Conventionally, a combination of a Fresnel lens sheet and a lenticular lens sheet has been used as a screen for a projector. 2. Description of the Related Art In recent years, there has been an increasing demand for project display of product information, advertisements and the like while maintaining the transparency of the show windows of department stores and the like, and transparent partitions of event spaces. In addition, it is said that in the future, the demand for transparent screens used for head-up displays, wearable displays, etc. will increase more and more.

However, the conventional projector screen has a low transparency, and thus has a technical problem that it cannot be applied to a transparent partition or the like. Therefore, various screens that can realize high transparency have been proposed. For example, on a plastic film or sheet, 7 parts by weight of aluminum scale and 25 parts by weight of pearl pigment scale coated with titanium dioxide having mica as a matrix are mixed and printed with an ink as a filler to form a light reflection layer. A reflective screen characterized by the above has been proposed (see Patent Document 1). Further, on the substrate, 100 to 100 parts by weight of a binder resin, 10 to 80 parts by weight of a non-reefing type scaly aluminum paste as a light reflecting agent, and a light diffusing agent of 50% by weight or more based on the light reflecting agent is used. A reflective screen for a projector, which is characterized by providing a diffusion layer, has been proposed (see Patent Document 2). Furthermore, a reflective screen has been proposed in which a light diffusion layer formed of a continuous layer made of a transparent resin and a dispersion layer made of anisotropic transparent particles is laminated on a light reflection substrate. (See Patent Document 3).

JP-A-3-119334 JP, 10-186521, A JP, 2004-54132, A

However, the present inventors have found that Patent Documents 1 to 3 have the following technical problems. Since the reflective screen described in Patent Document 1 has a scale particle coated on the surface of the substrate at a high concentration, the image cannot be clearly recognized due to the glare of the coating film, and a white vinyl chloride film is used for the substrate. However, there is a technical problem that it is impossible to see through. The reflective screen described in Patent Document 2 contains a scale-like aluminum paste as a light-reflecting agent in a high concentration of 10 to 80 weight, and there is a technical problem that the obtained film cannot be seen through. In the reflection screen described in Patent Document 3, the anisotropic transparent particles dispersed in the dispersion layer are non-metallic particles of mica, talc, and montmorillonite, and since talc and montmorillonite are clay-based particles, regular reflectance is high. Is low, and there is a technical problem that it cannot be suitably used as a reflective transparent screen. Furthermore, although the screens described in Patent Documents 1 to 3 have improved scratch resistance and antifouling property to some extent, peeling occurs from the scratched part when scratched once because it is a coating layer of an organic material. However, due to the interaction between the coating layer and the oil content of the fingerprint, there is a problem that the fingerprint is difficult to wipe off, and higher scratch resistance, abrasion resistance, long-term stability and antifouling property are desired.

The present invention has been made in view of the above technical problems, and an object thereof is excellent visibility of projection light and visibility of transmitted light by anisotropically scattering and reflecting projection light, and a viewing angle. It is intended to provide a glass composite for a transparent screen, which is widely used, has improved scratch resistance and antifouling property, and is not deteriorated with time even during long-term use. Another object of the present invention is to provide a transparent screen provided with the glass composite, and an image projection system provided with the glass composite or the transparent screen and a projection device.

In order to solve the above technical problems, the present inventors have conducted extensive studies, and as a result, by dispersing at least one of the glittering flaky fine particles and substantially spherical fine particles in the inorganic glass, the above technical problems It was found that a glass composite which can be suitably used for a transparent screen can be obtained. The present invention has been completed based on such findings.

That is, according to one aspect of the present invention,
Provided is a glass composite for a transparent screen, which comprises an inorganic glass and at least one of glittering flaky fine particles and substantially spherical fine particles.

In the aspect of the present invention, the average diameter of the primary particles of the glittering flaky fine particles is preferably 0.01 to 100 μm.

In the aspect of the present invention, the specular reflectance of the glittering flaky fine particles is preferably 12% or more.

In the aspect of the present invention, it is preferable that the glittering flaky fine particles have an average aspect ratio of 3 to 800.

In the aspect of the present invention, the glittering flaky fine particles include aluminum, copper, tin-cobalt alloy, silver, platinum, gold, titanium, nickel, tin, indium, chromium, titanium oxide, aluminum oxide, and zinc sulfide. It is preferable to use metal-based particles selected from the group consisting of the following: a glittering material in which glass is coated with a metal or a metal oxide, or a glittering material in which natural mica or synthetic mica is coated with a metal or a metal oxide.

In the aspect of the present invention, the inorganic glass is preferably at least one selected from the group consisting of water glass, a sol-gel material, and a glass material having a softening temperature of 150 to 650°C.

In the aspect of the present invention, the content of the bright flaky fine particles is preferably 0.01 to 5.0 mass% with respect to the inorganic glass.

In the aspect of the present invention, the difference between the refractive index n ₂ of the substantially spherical fine particles and the refractive index n ₁ of the inorganic glass is represented by the following mathematical formula (1):
|n ₁ −n ₂ |≧0.1 (1)
It is preferable to satisfy.

In the aspect of the present invention, the substantially spherical fine particles are preferably at least one selected from the group consisting of zirconium oxide, titanium oxide, zinc oxide, cerium oxide, barium titanate, and strontium titanate.

In the aspect of the present invention, the median diameter of the primary particles of the substantially spherical fine particles is preferably 0.1 to 100 nm.

In the aspect of the present invention, the content of the substantially spherical fine particles is preferably 0.0001 to 2.0 mass% with respect to the inorganic glass.

In the aspect of the present invention, it is preferable that the glass composite is for a transmissive transparent screen or a reflective transparent screen.

According to another aspect of the present invention, there is provided a glass composite laminate comprising the glass composite of and a substrate.

According to another aspect of the present invention, there is provided a reflective transparent screen including the above glass composite.

According to another aspect of the present invention, there is provided a transmissive transparent screen comprising the above glass composite.

According to another aspect of the present invention, there is provided a vehicle member including the glass composite body, the transmissive transparent screen, or the reflective transparent screen.

According to another aspect of the present invention, there is provided a building member comprising the glass composite, the transmissive transparent screen, or the reflective transparent screen.

According to another aspect of the present invention, there is provided a video projection system comprising the glass composite, the transmissive transparent screen or the reflective transparent screen, and a projection device.

The glass composite for a transparent screen according to the present invention, when used as a transparent screen, can anisotropically scatter and reflect projection light without impairing transparency, thereby projecting a clear image on the transparent screen, Excellent viewing angle, scratch resistance, abrasion resistance, stain resistance, and long-term stability. That is, the glass composite according to the present invention can achieve both visibility of projected light and visibility of transmitted light, and can be suitably used as a transparent screen. Further, such a transparent screen can be suitably used for a glass window, a head-up display, a wearable display and the like.

1 is a schematic cross-sectional view in the thickness direction of an embodiment of a glass composite body according to the present invention. 1 is a schematic view showing an embodiment of a transparent screen and a video projection system according to the present invention.

<Glass composite>
The glass composite according to the present invention comprises an inorganic glass and at least one of glittering flaky fine particles and substantially spherical fine particles, and further laminates other layers such as an antireflection layer, an adhesive layer, and a substrate. You may. By using at least one of the glittering flaky fine particles and the substantially spherical fine particles to be described later, light is anisotropically scattered and reflected in the glass composite to improve the viewing angle. Inorganic glass is a material that has excellent scratch resistance and is chemically stable, so that it does not easily change over time when used for a long period of time. In particular, when photoactive particles such as titanium oxide are dispersed in the resin as glittering flaky fine particles or substantially spherical fine particles, deterioration of the resin is promoted, and thus it may not be used for a long period of time. In the present invention, the use of the inorganic glass makes it possible to produce a transparent screen that can be used for a long period of time even when photoactive fine particles are used.

The glass composite according to the present invention is transparent and can be suitably used as a transparent screen. The glass composite according to the present invention is excellent in visibility of projection light and visibility of transmitted light by anisotropically scattering and reflecting projection light, has a wide viewing angle, high transparency, and further excellent scratch resistance. It has abrasion resistance and long-term stability. Such a glass composite can be suitably used as a reflective transparent screen used for a head-up display, a wearable display and the like. In the present invention, the term “transparent” is sufficient if it is transparent to the extent that transmissivity and visibility can be realized according to the application, and includes being semitransparent.

FIG. 1 shows a schematic cross-sectional view in the thickness direction of one embodiment of the glass composite body according to the present invention. The laminated body 15 of the glass composite includes a glass composite 13 in which the glittering flaky fine particles 11 and the substantially spherical fine particles 12 are dispersed in the inorganic glass 10, and a base material 14. Such a laminated body of the glass composite body 15 anisotropically scatters the projection lights 16 and 17 so that the viewer 19 can visually recognize the scattered light 18.

The glass composite has a haze value of preferably 50% or less, more preferably 1% or more and 40% or less, more preferably 1.3% or more and 30% or less, and even more preferably 1.5%. It is 20% or less, and most preferably 2% or more and 10% or less. The total light transmittance is preferably 70% or more, more preferably 75% or more, further preferably 80% or more, and still more preferably 85% or more. When the haze value is within the above range, the transparency is high, the transmission visibility can be further improved, and the screen performance is excellent. In addition, in this invention, the haze value of a glass composite body is based on JIS-K-7361 and JIS-K-7136 using a turbidimeter (Nippon Denshoku Industries Co., Ltd. product number: NDH-5000). Can be measured.

The glass composite has a reflected front luminous intensity of preferably 3 or more and 60 or less, more preferably 4 or more and 50 or less, and further preferably 4.5 or more and 40 or less. Further, in the glass composite, the value obtained by multiplying the transmitted front luminosity by 1000 is preferably 1.5 or more, more preferably 2.0 or more, still more preferably 3.0 or more and 50 or less. .. When the value obtained by multiplying the reflected front light intensity and the transmitted front light intensity of the glass composite by 1000 is within the above range, the brightness of the reflected light is high and the performance as a reflective screen is excellent. In the present invention, the reflected light intensity and the reflected light intensity improvement rate of the glass composite are values measured as follows.
(Reflected front brightness)
The measurement was performed using a goniophotometer (manufactured by Nippon Denshoku Industries Co., Ltd., product number: GC5000L). The incident angle of the light source was set to 45 degrees, and the reflected light intensity in the 0 degree direction was set to 100 when a standard white plate having a whiteness of 95.77 was placed on the measurement stage. At the time of measuring the sample, the incident angle of the light source was set to 15 degrees, and the intensity of the reflected light in the 0 degree direction was measured.
(Transmitted front brightness)
The measurement was performed using a goniophotometer (manufactured by Nippon Denshoku Industries Co., Ltd., product number: GC5000L). The incident angle of the light source was set to 0 degree, and the transmitted light intensity in the 0 degree direction was 100 when nothing was placed on the measurement stage. In the sample measurement, the incident angle of the light source was set to 15 degrees, and the intensity of the transmitted light in the 0 degree direction was measured.

The glass composite has an image clarity of preferably 70% or more, more preferably 75% or more, still more preferably 80% or more, still more preferably 85% or more, and particularly preferably 90%. % Or more. When the image clarity of the glass composite is within the above range, the image seen through the transparent screen becomes extremely clear. In the present invention, the image clarity is a value of image clarity (%) when measured with an optical comb width of 0.125 mm in accordance with JIS K7374.

The thickness of the glass composite is not particularly limited, but is preferably 0.1 μm to 20 mm, more preferably 0.5 μm to, from the viewpoints of use, productivity, handleability, and transportability. It is 15 mm, and more preferably 1 μm to 10 mm.

(Inorganic glass)
As the inorganic glass forming the glass composite, it is preferable to use one having good dispersibility of the glittering flaky fine particles or substantially spherical fine particles to be described later, water glass, a sol-gel material, or a fine powder of glass having a low softening point. It is particularly preferable to use the dispersion liquid of. Since these glass materials are in a liquid state, they have good dispersibility of glittering flaky fine particles or substantially spherical fine particles and are excellent in moldability. In the present specification, the glass composite may be fine particle-dispersed glass (glass composite) obtained by curing liquid inorganic glass by a curing reaction such as sintering or hydrolysis reaction of sol-gel, and melted. Fine particle-dispersed glass (glass composite) obtained by dispersing fine particles in inorganic glass (silica sand, soda ash, glass scraps such as limestone and cullet) and cooling may be used.

(Water glass)
Water glass is a concentrated aqueous solution of alkali silicate, and sodium is usually contained as an alkali metal. A typical water glass can be represented by Na ₂ O.nSiO ₂ (n: any positive number). Commercially available water glass has n in the range of 2 to 4. Commercially available water glasses include Nos. 1 to 3 as aqueous sodium silicate solutions, and the ratio of SiO ₂ to Na ₂ O increases in this order. When water is evaporated from water glass, a water-containing glass, which contains about 10 to 30 mass% of water and forms a solid that is hard to crack and has elasticity, and exhibits a function as a binder having adhesiveness. In some cases, K ₂ O may be partially contained in place of Na ₂ O, and even in this case, the molar ratio with SiO ₂ is preferably in the above range. The function as a binder tends to form a coating film with higher mechanical strength as the molecular weight of the polysilicate ion contained in water glass is higher, but cracks may easily form in the coating film, so as a coating solution It is preferable to use water glass that is contained at an optimum molar ratio of SiO _{2 to} Na ₂ O, depending on the concentration and pH of water glass contained when used, and the ratio with respect to hydroxyapatite. As the water glass, sodium silicate manufactured by Fuji Chemical Co., Ltd. can be used.

(Sol-gel material)
The sol-gel material is a group of compounds that undergo hydrolysis and polycondensation under the action of heat, light, a catalyst, or the like to be cured. For example, it is a metal alkoxide (metal alcoholate), a metal chelate compound, a metal halide, a liquid glass, a spin-on glass, or a reaction product thereof, which may contain a catalyst for accelerating the curing reaction. Further, a part of the metal alkoxide functional group may have a photoreactive functional group such as an acrylic group. The sol-gel materials may be used alone or in combination of a plurality of types, depending on the required physical properties. The cured film of the sol-gel material refers to a state in which the polymerization reaction of the sol-gel material has proceeded sufficiently. The sol-gel material is chemically bonded and strongly adheres to the surface of the inorganic substrate during the polymerization reaction. Therefore, by using a cured film of a sol-gel material as the glass composite, a stable glass composite can be formed.

The metal alkoxide is a group of compounds obtained by reacting an arbitrary metal species with a catalyst such as a hydrolysis catalyst with water or an organic solvent. It is a compound group in which a functional group such as a group is bonded. Examples of the metal species of the metal alkoxide include silicon, titanium, aluminum, germanium, boron, zirconium, tungsten, sodium, potassium, lithium, magnesium and tin.

Examples of the metal alkoxide having a metal species of silicon include dimethyldiethoxysilane, diphenyldiethoxysilane, phenyltriethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, p-styryltriethoxysilane, methylphenyldiethoxysilane, and the like. 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane (MTES), 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3 -Methacryloxypropyltriethoxysilane, 3-acryloxypropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane Silane, 3-aminopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 3-mercaptopropyltriethoxysilane, triethoxysilane (TEOS), diphenylsilanediol, dimethylsilanediol, etc. Or a group of compounds in which the ethoxy group of these compounds is replaced with a methoxy group, a propyl group, an isopropyl group, a hydroxy group, or the like. Among these, TEOS, tetramethoxysilane (TMOS) in which the ethoxy group of TEOS is replaced with a methoxy group, and MTES are particularly preferable. These may be used alone or in combination of a plurality of types.

When TEOS, MTES or a mixture thereof is used, the mixing ratio thereof can be, for example, 1:1 by molar ratio. This sol solution produces an amorphous silica by carrying out hydrolysis and polycondensation reactions. As a synthesis condition, an acid such as hydrochloric acid or an alkali such as ammonia may be added to adjust the pH of the solution. The pH is preferably 4 or less or 10 or more. Further, water may be added to carry out hydrolysis. The amount of water added can be 1.5 times or more the molar ratio of the metal alkoxide species.

A silsesquioxane compound can also be used as the metal alkoxide. Silsesquioxane is a general term for a compound group represented by SiO _1.5 , and is a compound in which one organic group and three oxygen atoms are bonded to one silicon atom. The metal halide is a group of compounds in which the functional group for hydrolytic polycondensation in the above metal alkoxide is replaced with a halogen atom.

As the metal chelate compound, titanium diisopropoxy bis acetyl acetonate, titanium tetrakis acetyl acetonate, titanium dibutoxy bis octylene glycolate, zirconium tetrakis acetyl acetonate, zirconium dibutoxy bis acetyl acetonate, aluminum tris acetyl acetonate, Examples thereof include aluminum dibutoxy monoacetylacetonate, zinc bisacetylacetonate, indium trisacetylacetonate, and polytitanium acetylacetonate.

Examples of the liquid glass include TGA series manufactured by Apollo Ring Co., Ltd., and other sol-gel compounds can be added depending on required physical properties. As the spin-on glass, for example, OCD series manufactured by Tokyo Ohka Co., Ltd., ACCUGLASS series manufactured by Honeywell, etc. can be used.

Various acids and bases can be used as the catalyst for promoting the curing. The various acids include not only inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid, but also organic acids such as various carboxylic acids, unsaturated carboxylic acids and acid anhydrides. Further, when the curing is photocuring, a photopolymerization initiator, a photoacid generator, a photosensitizer and the like used in the UV curable resin can be used.

The sol-gel material may contain a solvent before use. Suitable solvents include, for example, methanol, ethanol, isopropyl alcohol (IPA), butanol, alcohols such as 2-butanol, hexane, heptane, octane, decane, aliphatic hydrocarbons such as cyclohexane, benzene, toluene, xylene, and the like. Aromatic hydrocarbons such as mesitylene, ethers such as diethyl ether, tetrahydrofuran, dioxane, ketones such as acetone, methyl ethyl ketone, isophorone, cyclohexanone, butoxyethyl ether, hexyloxyethyl alcohol, methoxy-2-propanol, benzyloxyethanol Ether alcohols such as, ethylene glycol, glycols such as propylene glycol, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, glycol ethers such as propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, esters such as γ-butyrolactone, phenol, Phenols such as chlorophenol, amides such as N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone, halogen-based solvents such as chloroform, methylene chloride, tetrachloroethane, monochlorobenzene and dichlorobenzene, 2 Examples thereof include a hetero element-containing compound such as carbon sulfide, water, and a mixed solvent thereof. In particular, ethanol and isopropyl alcohol, or a solvent obtained by mixing them with water is preferable.

The sol-gel material includes polyethylene glycol, polyethylene oxide, hydroxypropyl cellulose, polyvinyl alcohol for adjusting viscosity, alkanolamines such as triethanolamine which is a solution stabilizer, β-diketone such as acetylacetone, β-ketoester, formamide, Dimethylformamide, dioxane and the like may be applied.

(Low softening point glass material)
The low softening point glass material preferably has a softening temperature in the range of 150 to 620°C, more preferably in the range of 200 to 600°C, and most preferably in the range of 250 to 550°C. As a glass material of the range, the heat treatment _PbO-B 2 _{O 3 -based, PbO-B 2 O 3 -SiO} 2 _{system, PbO-ZnO-B 2 O} 3 system, a mixture comprising an acid component and a metal chloride The lead-free low softening point glass etc. obtained by doing can be used. Among these, it is preferable to use lead-free low softening point glass, which has particularly low environmental pollution. The low softening point glass material is preferably so-called glass frit, which is melted in the curing step described later. As the low softening point glass material, it is preferable to use a powder having a median diameter in the range of 1 to 50 μm. The low softening point glass material may be mixed with a binder, a polar solvent, a high boiling point organic solvent or the like in order to improve the dispersibility of fine particles and the moldability.

As the binder, a urethane resin, an acrylic resin, an acrylic silicon resin, a non-chlorinated polyolefin resin, a polyester resin, cellulose acetate or the like can be used, and among them, acrylic resin and cellulose acetate are particularly preferable. The binder concentration is preferably 0.2 to 40 parts by mass, more preferably 0.5 to 20 parts by mass, and still more preferably 1 to 10 parts by mass with respect to the mass of the low softening point glass material.

The polar solvent is preferably water, alcohol (methanol, ethanol, isopropyl alcohol, etc.), acetone, methyl ethyl ketone, butyl acetate, ethyl acetate, petroleum ether or the like. The amount of the solvent used is preferably 100 to 900 parts by mass, more preferably 150 to 800 parts by mass, and further preferably 200 to 500 parts by mass with respect to the mass of the low softening point glass material.

The high-boiling organic solvent is not particularly limited, but mineral oil, vegetable oil, synthetic drying oil and the like can be used, for example, terpine oil, butyl carbitol acetate, xylene, butyl cellosolve, terpineol, cellosolve acetate, alkyl alcohol, acetate, It is preferable to use propionate, higher alkyl ester, pine oil and the like. The high boiling point organic solvent is preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass, and still more preferably 3 to 10 parts by mass with respect to the mass of the low softening point glass material.

(Glittering flaky fine particles)
As the glittering flaky fine particles, a glittering material that can be processed into flakes can be preferably used. The specular reflectance of the glittering flaky fine particles is preferably 12.0% or more, more preferably 15.0% or more, still more preferably 20.0% or more and 80.0% or less. In the present invention, the specular reflectance of the glittering flaky fine particles is a value measured as follows.
(Regular reflectance)
It was measured using a spectrophotometer (manufactured by Konica Minolta Co., Ltd., product number: CM-3500d.) The glittering flaky fine particles dispersed in an appropriate solvent (water or methyl ethyl ketone) had a film thickness of 0. The coated glass plate was coated and dried to a thickness of 5 mm or more, and the specular reflectance of the obtained coated glass plate when light is incident on the coated film from the glass surface at an angle of 45 degrees with respect to the normal to the glass surface. By measuring the regular reflectance when the glittering flaky fine particles are formed into a coating film, the reflection performance of the glittering flaky fine particles can be grasped in consideration of the oxidation state of the surface of the fine particles.

As the metal material used for the metal-based fine particles, a metal having excellent reflectivity of projection light is used. Specifically, the metallic material has a reflectance R at a measurement wavelength of 550 nm of preferably 50% or more, more preferably 55% or more, further preferably 60% or more, and still more preferably 70% or more. Is. Hereinafter, in the present invention, the “reflectance R” refers to the reflectance when light is incident on the metal material in the vertical direction. The reflectance R can be calculated by the following equation (1) using the values of the refractive index n and the extinction coefficient k, which are the intrinsic values of the metal material. n and k are, for example, Handbook of Optical Constants of Solids: Volume 1 (by Edward D. Palik), PB Johnson and RW Christy, PHYSICAL REVIEW B, Vol.6, No.12, 4370-4379 (1972). Have been described.
^{R = {(1-n)} 2 + k 2} / {(1 + n) 2 + k 2} Equation (1)
That is, the reflectance R(550) at the measurement wavelength of 550 nm can be calculated from n and k when measured at the wavelength of 550 nm. For the metal material, the absolute value of the difference between the reflectance R(450) at the measurement wavelength 450 nm and the reflectance R(650) at the measurement wavelength 650 nm is within 25% with respect to the reflectance R(650) at the measurement wavelength 550 nm. Yes, it is preferably within 20%, more preferably within 15%, and further preferably within 10%. By using such a metal material, when it is used as a reflective transparent screen, it has excellent projection light reflectivity and color reproducibility, and excellent screen performance.

The metal material used for the metal-based fine particles preferably has a real number term ε'of dielectric constant of -60 to 0, more preferably -50 to -10. The real term ε'of the dielectric constant can be calculated by the following equation (2) using the values of the refractive index n and the extinction coefficient k.
ε′=n ² −k ² Formula (2)
Although the present invention is not bound to any theory, the following action occurs when the real number term ε'of the dielectric constant of the metal material satisfies the above numerical range, and the transparent light scatterer serves as a reflective transparent screen. It is considered that it can be preferably used. That is, when light enters the metal-based fine particles, an oscillating electric field due to the light is generated in the metal-based fine particles, but at the same time, reverse electric polarization occurs due to free electrons of the metal-based fine particles to shield the electric field. When the real number light ε'of the dielectric constant is 0 or less, the light is completely shielded and the light cannot enter into the metal-based fine particles, that is, there is no diffusion due to surface irregularities or light absorption by the metal-based fine particles. Assuming an ideal state, all the light will be reflected by the surface of the metal-based fine particles, so the light reflectivity is strong. When ε'is larger than 0, the vibration of the free electrons of the metal-based fine particles cannot follow the vibration of light, so the oscillating electric field due to the light cannot be completely canceled out, and the light enters the metal-based fine particles. It is transparent. As a result, only a part of light is reflected on the surface of the metal-based fine particles, and the light reflectivity becomes low.

Any metal material may be used as long as it satisfies the above reflectance R, preferably a dielectric constant, and a pure metal or an alloy may be used. The pure metal is preferably one selected from the group consisting of aluminum, silver, platinum, titanium, nickel and chromium. As the metal-based fine particles, it is possible to use fine particles made of these metal materials or fine particles obtained by coating these metal materials with resin, glass, natural mica or synthetic mica. The shape of the metal-based fine particles is not particularly limited, and flaky fine particles or substantially spherical fine particles can be used. Table 1 shows the refractive index n and the extinction coefficient k at various measurement wavelengths, and Table 2 shows the reflectances R and ε'calculated using these values, for various metal materials.

As the glittering flaky fine particles, depending on the kind of the inorganic glass to be dispersed, for example, aluminum, silver, copper, platinum, gold, titanium, nickel, tin, tin-cobalt alloy, metal-based fine particles such as indium and chromium. , Or metallic fine particles composed of titanium oxide, aluminum oxide and zinc sulfide, a glittering material obtained by coating glass with a metal or a metal oxide, or a glittering material obtained by coating natural mica or synthetic mica with a metal or a metal oxide. Can be used.

The glittering flaky fine particles have an average primary particle diameter of preferably 0.01 to 100 μm, more preferably 0.05 to 80 μm, still more preferably 0.1 to 50 μm, and even more preferably 0.5 to 30 μm. .. Further, the glittering flaky fine particles have an average aspect ratio (=average diameter of the glittering flaky fine particles/average thickness) of preferably 3 to 800, more preferably 4 to 700, further preferably 5 to 600, and even more preferably Is 10 to 500. When the average diameter and the average aspect ratio of the glittering flaky fine particles are within the above ranges, when the glass composite is used for a transparent screen, a sufficient scattering effect of projection light can be obtained without impairing the visibility of transmission. This makes it possible to project a clear image. In the present invention, the average diameter of the glittering flaky fine particles was measured using a laser diffraction particle size distribution measuring device (manufactured by Shimadzu Corporation, product number: SALD-2300). The average aspect ratio was calculated from an SEM (manufactured by Hitachi High-Technologies Corporation, trade name: SU-1500) image.

As the glittering flaky fine particles, commercially available products may be used, and for example, aluminum powder manufactured by Daiwa Metal Powder Co., Ltd., metal-coated glass manufactured by Matsuo Sangyo Co., Ltd. (Metashine series) can be preferably used. ..

The content of the glittering flaky fine particles in the glass composite can be appropriately adjusted according to the regular reflectance of the glittering flaky fine particles, and is preferably 0.0001 to 5.0 mass with respect to the inorganic glass. %, preferably 0.0005 to 3.0% by mass, and more preferably 0.001 to 1.0% by mass. By dispersing the glittering flaky fine particles in the inorganic glass at a low concentration within the above range to form a glass composite, the projection light emitted from the light source is anisotropically scattered and reflected, thereby And the visibility of transmitted light can be improved.

(Substantially spherical fine particles)
The substantially spherical fine particles may include true spherical particles, or may include spherical particles having irregularities or protrusions. Refractive index n ₁ and substantially the refractive index n ₂ of the spherical fine particles of an inorganic glass, the following equation (1):
_{| N 2 -n 1 | ≧ 0.1} ··· (1)
It is preferable that the following formula (2):
_{| N 2 -n 1 | ≧ 0.15} ··· (2)
It is more preferable to satisfy the following formula (3):
3.0≧|n ₂ −n ₁ |≧0.2 (3)
It is more preferable to satisfy. When the refractive indexes of the inorganic glass and the substantially spherical fine particles forming the glass composite satisfy the above mathematical formula, light is anisotropically scattered in the glass composite, and the viewing angle can be improved. In addition, by using substantially spherical fine particles, light can be scattered in all directions and brightness can be improved.

As the substantially spherical fine particles having a high refractive index, for example, the refractive index n ₂ is preferably 1.80 to 3.55, more preferably 1.9 to 3.3, and further preferably 2.0 to. It is possible to use metal-based particles obtained by atomizing a metal oxide or a metal salt, which is 3.0. Examples of the metal oxide include zirconium oxide (ZrO ₂ , n=2.40), zinc oxide (ZnO ₂ , n=2.40), titanium oxide (TiO ₂ , n=2.72), and cerium oxide. (CeO ₂ , n=2.20) and the like. Examples of the metal salt include barium titanate (BaTiO ₃ , n=2.40) and strontium titanate (SrTiO ₃ , n=2.37). These substantially spherical fine particles may be used alone or in combination of two or more.

The median diameter of primary particles of substantially spherical fine particles is preferably 0.1 to 100 nm, more preferably 0.2 to 70 nm, and further preferably 0.5 to 50 nm. When the median diameter of the primary particles of the substantially spherical fine particles is within the above range, when used as a transparent screen, a sufficient diffusion effect of projection light can be obtained without impairing the visibility of transmission, resulting in a clear screen. The image can be projected. In the present invention, the median diameter (D ₅₀ ) of the primary particles of the inorganic fine particles was measured by a dynamic light scattering method using a particle size distribution measuring device (Otsuka Electronics Co., Ltd., trade name: DLS-8000). It can be determined from the particle size distribution.

The content of the substantially spherical fine particles can be appropriately adjusted according to the thickness of the glass composite and the refractive index of the fine particles. The content of the fine particles in the glass composite is preferably 0.0001 to 2.0% by mass, more preferably 0.001 to 1.0% by mass, and further preferably 0 based on the inorganic glass. 0.005-0.5% by mass, and even more preferably 0.01-0.3% by mass. If the content of the substantially spherical fine particles in the glass composite is within the above range, while ensuring the transparency of the glass composite, by anisotropically and sufficiently diffusing the projection light emitted from the projection device, It is possible to achieve both visibility of diffused light and visibility of transmitted light.

The concentration of the bright flaky fine particles and/or the substantially spherical fine particles with respect to the inorganic glass is such that the thickness of the glass composite is t (μm), and the bright flaky fine particles and/or the substantially spherical shape with respect to the inorganic glass. When the concentration of the fine particles is c (mass %), t and c are represented by the following mathematical formula (I):
0.05≦(t×c)≦50 (I)
Preferably satisfies
0.1≦(t×c)≦40 (I-2)
More preferably,
0.15≦(t×c)≦35 (I-3)
More preferably,
0.3≦(t×c)≦30 (I-4)
It is even more preferable to satisfy the following. When the thickness t and the concentration c of the glass composite satisfy the above mathematical expression (I), the dispersion state of the fine particles in the glass composite is sparse (the concentration of the fine particles in the glass composite is low), and therefore the glass composite is straightforward. The ratio of transmitted light is increased (the ratio of light that does not collide with fine particles is increased), and as a result, a clear image can be displayed on the screen without impairing the visibility of transmitted light. When two or more types of glittering flaky fine particles and/or substantially spherical fine particles are contained, the concentration c is the total concentration of all fine particles.

The thickness of the glass composite is not particularly limited, but is preferably 0.01 μm to 1 mm, more preferably 0.1 μm to 500 μm, and further preferably 1 μm to 300 μm. When the thickness of the cured film is within the above range, the function as a transparent screen can be sufficiently exhibited. The glass composite may have a single-layer structure or a multi-layer structure in which two or more layers are laminated by coating or the like.

The glass composite has a scratch hardness of HB or more, preferably H or more, more preferably 2H or more, measured according to JIS-K5600-5-4 (scratch hardness method). Is more preferable.

(Antireflection layer)
The antireflection layer is a layer for improving image visibility by reducing reflection of external light and reflection of incident light from the projector on the layer surface. Furthermore, the antireflection layer suppresses a part of the light emitted from the light source from being reflected on the screen surface, and as a result, the amount of light entering the glass composite increases, so that the antireflection layer has a brightness improving effect. The antireflection layer may be laminated on the viewer side of the glass composite, or may be laminated on both sides. The antireflection layer may be a single layer, or may be a multi-layer laminate of resins having different refractive indexes in order to prevent reflection in the entire wavelength region.

The antireflection layer can be formed using a resin that does not impair the transmission visibility and desired optical properties of the glass composite. As such a resin, for example, a resin curable by ultraviolet rays or electron beams, that is, an ionizing radiation curable resin, a mixture of an ionizing radiation curable resin with a thermoplastic resin and a solvent, and a thermosetting resin should be used. However, among these, ionizing radiation curable resins are particularly preferable.

Further, the antireflection layer may be composed of a thin film layer of an inorganic material such as metal and metal oxide that does not impair the transmission visibility and desired optical properties of the glass composite. The inorganic material is not particularly limited, but for example, TiO ₂ (n=2.72), ZrO ₂ , (n=2.40), and SiO are taken into consideration in consideration of vapor deposition easiness, translucency, and the like. ₂ (n=1.46), magnesium fluoride (MgF ₂ , (n=1.39), calcium fluoride (CaF ₂ , (n=1.39), CeO ₂ (n=2.45), oxidation) Examples thereof include tin (SnO ₂ , n=2.30), tantalum (V) oxide (Ta ₂ O ₅ , n=2.12), indium oxide (In ₂ O ₃ n=2.00), and the like.

The thickness of the antireflection layer is preferably 50 nm to 100 μm, more preferably 80 nm to 80 μm, and further preferably 90 nm to 100 μm. When the thickness of the antireflection layer is in the above range, an excellent antireflection function can be imparted while maintaining high transparency.

(Base material)
The base material is a support for forming the glass composite into a thin film. The base material is specifically a substrate made of an inorganic material such as metal, ceramics, soda glass, quartz glass, sapphire substrate, quartz, silicon substrate, polyethylene terephthalate (PET), polyethylene terephthalate (PEN), polycarbonate (PC). ), cycloolefin polymer (COP), polymethylmethacrylate (PMMA), polystyrene (PS), polyimide (PI), polyarylate, and other resin substrates can be used. The substrate may be transparent or opaque, but for example, an optically transparent base material in the visible light region of 400 nm to 780 nm can be used not only as a transparent screen but also for various optical applications other than the screen. Particularly preferred. When used in the ultraviolet region, it is preferable to use a substrate containing quartz glass or sapphire glass, which has a high transmittance of ultraviolet rays. A surface treatment or an easy-adhesion layer may be provided on the substrate in order to improve the adhesiveness, and a gas barrier layer may be provided in order to prevent the intrusion of gas such as moisture or oxygen. Further, when the curing reaction includes a high temperature step such as sintering, it is preferable to use a material that is not softened or damaged at a high temperature. Specifically, a glass substrate having a softening temperature of 600°C or higher is preferable, one having a softening temperature of 650°C or higher is more preferable, and one having a softening temperature of 700°C or higher is most preferable. The base material may be a flat plate, or may have any shape depending on the purpose of use. The thickness of the base material can be appropriately changed according to the application and material so that the strength thereof is appropriate. For example, it may be in the range of 10 μm to 1 mm (1000 μm), and may be a thick plate of 1 mm or more.

(Adhesive layer)
The adhesive layer is a layer for adhering a substrate, an antireflection layer, etc. on at least one surface of the glass composite. It is also possible to provide an adhesive layer on both sides of the glass composite and produce a laminated structure in which the glass composite is sandwiched between base materials. The pressure-sensitive adhesive layer is preferably formed using a pressure-sensitive adhesive composition that does not impair the transmission visibility and desired optical properties of the glass composite. Examples of the adhesive composition include natural rubber-based, synthetic rubber-based, poly(meth)acrylic-based, polyvinyl ether-based, polyurethane-based, polysilicone-based, polyvinyl alcohol-based and the like. Specific examples of the synthetic rubber system include styrene-butadiene rubber, acrylonitrile-butadiene rubber, polyisobutylene rubber, isobutylene-isoprene rubber, styrene-isoprene block copolymer, styrene-butadiene block copolymer, styrene-ethylene-butylene block. A copolymer is mentioned. Specific examples of polyvinyl alcohol include polyvinyl butyral and ethylene-vinyl acetate resin. Specific examples of the poly-silicone type include dimethyl polysiloxane and the like. Among these, polyvinyl alcohol adhesives and acrylic adhesives are preferable. These adhesives can be used alone or in combination of two or more.

The acrylic resin pressure-sensitive adhesive is a polymer containing at least a (meth)acrylic acid alkyl ester monomer. It is generally a copolymer of a (meth)acrylic acid alkyl ester monomer having an alkyl group having about 1 to 18 carbon atoms and a monomer having a carboxyl group. In addition, (meth)acrylic acid means acrylic acid and/or methacrylic acid. Examples of the (meth)acrylic acid alkyl ester monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, sec-propyl (meth)acrylate, and (meth)acrylic acid. n-butyl, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, (meth)acrylic acid Examples thereof include n-octyl, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, undecyl (meth)acrylate, and lauryl (meth)acrylate. The (meth)acrylic acid alkyl ester is usually copolymerized in the acrylic pressure-sensitive adhesive in a proportion of 30 to 99.5 parts by mass.

Further, as the monomer having a carboxyl group forming the acrylic resin adhesive, a monomer containing a carboxyl group such as (meth)acrylic acid, itaconic acid, crotonic acid, maleic acid, monobutyl maleate and β-carboxyethyl acrylate. Can be mentioned.

In addition to the above, the acrylic resin pressure-sensitive adhesive may be copolymerized with a monomer having another functional group within a range not impairing the properties of the acrylic resin pressure-sensitive adhesive. Examples of monomers having other functional groups include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and monomers containing a hydroxyl group such as allyl alcohol; (meth)acrylamide, N-methyl. Monomers containing amide groups such as (meth)acrylamide and N-ethyl(meth)acrylamide; monomers containing amide groups and methylol groups such as N-methylol(meth)acrylamide and dimethylol(meth)acrylamide; aminomethyl( Monomers having functional groups such as amino group-containing monomers such as (meth)acrylate, dimethylaminoethyl (meth)acrylate and vinylpyridine; epoxy group-containing monomers such as allyl glycidyl ether and (meth)acrylic acid glycidyl ether Can be mentioned. In addition to these, fluorine-substituted (meth)acrylic acid alkyl esters, (meth)acrylonitrile, and the like, vinyl group-containing aromatic compounds such as styrene and methylstyrene, vinyl acetate, vinyl halide compounds, and the like can be given.

A commercially available adhesive may be used as the adhesive, for example, SK dyne 2094, SK dyne 2147, SK dyne 1811L, SK dyne 1442, SK dyne 1435, and SK dyne 1415 (above, manufactured by Soken Chemical Co., Ltd.), Olivine EG-655, Olivine BPS5896 (above, manufactured by Toyo Ink Co., Ltd.) and the like (above, trade name) can be preferably used.

<Method for producing glass composite>
The method for producing a glass composite according to the present invention is not particularly limited, using a glass composite material in which at least one of glittering flaky fine particles or substantially spherical fine particles is dispersed in the inorganic glass, The glass composite can be formed by a conventionally known molding method. For example, the method for producing a glass composite according to the present invention includes (1) a step of producing an inorganic glass solution in which at least one of glittering flaky fine particles and substantially spherical fine particles, inorganic glass, and a solvent are mixed, (2) The method includes the steps of applying an inorganic glass solution to a substrate to form a coating film, (3) drying a solvent, and (4) curing the coating film. The glass composite is industrially manufactured by dispersing the fine particles in an inorganic glass melted at a high temperature such as a float method and a roll-out method, and molding and cooling to produce a plate-shaped glass composite. You can also

(1) Inorganic glass solution preparation step The inorganic glass solution is prepared by mixing at least one of glittering flaky fine particles or substantially spherical fine particles, inorganic glass, and a solvent, and if necessary, a binder, a high-boiling organic solvent, a catalyst, etc. Is prepared by adding and dispersing. Since the inorganic glass solution is a solid dispersion, long-term storage stability is not always sufficient. Therefore, at least one of the glittering flaky fine particles or substantially spherical fine particles, an inorganic glass, if necessary, a binder containing a binder, a catalyst, a high boiling point organic solvent, etc. is prepared in advance, and a solvent is added to the paste at the time of use. It is preferable to add and disperse to prepare a glass material solution. In this case, the paste can be prepared by a known dispersion method.

The dispersion method is not particularly limited, and it can be carried out using a dispersion device that is commonly used for dispersing pigments and the like. As the dispersing device, mixers such as disperser, homomixer and planetary mixer, homogenizer (manufactured by M Technique Co., Ltd., trade name: CLEARMIX, PRIMIX Co., tradename: FILMIX), ball mill, sand mill (Simmar Enterprise) SUZU company: product name: Dynomill), attritor, wet jet mill (Genus product: product name Genus PY, medialess disperser (manufactured by Nara Machinery Co., product name MICROS), and other roll mills.

(2) Application step The application of the prepared inorganic glass solution to the substrate is carried out by a known method, for example, spin coating, dip coating, bar coating, flow coating, roll coating, spray coating, die coating, inkjet, gravure coating, etc. It can be carried out. Above all, bar coating, die coating and spin coating are preferable from the viewpoint that the sol-gel solution can be uniformly applied to a substrate having a relatively large area and the application can be completed quickly before the sol solution is cured.

(3) Drying Step After the coating step, the substrate is held in the atmosphere or under reduced pressure to evaporate the solvent in the applied coating film. If this holding time is short, the solvent remains and the durability deteriorates. The holding temperature is preferably in the range of 10 to 200°C, more preferably 10 to 100°C. If the holding temperature is higher than this range, the curing reaction will proceed rapidly, which is not preferable, and if the holding temperature is lower than this range, the curing reaction will take a long time, and the productivity will decrease, which is not preferable.

(4) Curing step The curing reaction is preferably carried out at 200 to 700° C., though it depends on the type of inorganic glass. If the temperature is 200° C. or lower, the curing will be insufficient and the strength of the glass composite after curing will be low. At 700°C or higher, the base material may be damaged. The curing time is preferably about 5 minutes to 1 hour, more preferably about 10 to 30 minutes. Oxidation of glittering flaky fine particles or substantially spherical fine particles may start at a temperature of 450° C. or higher. Therefore, when the curing reaction is performed in such a temperature range, a low oxygen atmosphere (nitrogen gas, argon gas, etc. It is preferably carried out in an active gas or in a vacuum).

<Transparent screen>
The transparent screen according to the present invention comprises the above glass composite. The transparent screen may be made of only the above glass composite, the substrate coated with the inorganic glass solution may be used as it is, or the transparent screen may be further provided with a support such as a transparent partition. The transparent screen may have a flat surface, a curved surface, or an uneven surface.

The transparent screen according to the present invention may be a rear projection type screen (transmission type screen) or a front projection type screen (reflection type screen). That is, in the image display device including the transparent screen according to the present invention, the position of the light source may be on the side opposite to the viewer with respect to the screen (transmissive screen) or on the viewer side (reflective type). screen). Such a transparent screen anisotropically scatters and reflects the projection light emitted from the light source to provide excellent visibility of the projection light and transmitted light, a wide viewing angle, and excellent antiglare and brightness. I have.

The haze value of the transparent screen is preferably 50% or less, more preferably 1% or more and 40% or less, still more preferably 1.3% or more and 30% or less, still more preferably 1.5% or more. It is 20% or less. In addition, the transparent screen has a total light transmittance of preferably 70% or more, more preferably 75% or more, further preferably 80% or more, and still more preferably 85% or more. The transparent screen has a diffuse transmittance of preferably 1.5% or more and 60% or less, more preferably 1.7% or more and 55% or less, and more preferably 1.9% or more and 50% or less. And more preferably 2.0% or more and 45% or less. If the haze value and the total light transmittance are within the above range, the transparency is high and the transmission visibility can be further improved. If the diffuse transmittance is within the above range, the incident light is efficiently diffused. Since the viewing angle can be further improved, the performance as a screen is excellent. In the present invention, the haze value, total light transmittance, and diffuse transmittance of the transparent screen are measured by using a turbidimeter (manufactured by Nippon Denshoku Industries Co., Ltd., product number: NDH-5000) according to JIS-K-7361 and It can be measured according to JIS-K-7136.

The transparent screen has an image clarity of preferably 70% or more, more preferably 75% or more, further preferably 80% or more, still more preferably 85% or more, and particularly preferably 90%. That is all. When the image clarity of the transparent screen is within the above range, the image seen through the transparent screen becomes extremely clear. In the present invention, the image clarity is a value of image clarity (%) when measured with an optical comb width of 0.125 mm in accordance with JIS K7374.

The transparent screen has a reflection front luminous intensity of preferably 3 or more and 60 or less, more preferably 4 or more and 50 or less, and further preferably 4.5 or more and 40 or less. Further, in the transparent screen, the value obtained by multiplying the transmitted front luminosity by 1000 is preferably 1.5 or more, more preferably 2.0 or more, still more preferably 3.0 or more and 50 or less. When the value obtained by multiplying the reflected front light intensity and the transmitted front light intensity of the transparent screen by 1000 is within the above range, the brightness of the reflected light is high and the performance as a reflective screen is excellent. In the present invention, the reflected light intensity and the reflected light intensity improvement rate of the transparent screen are values measured as follows.
(Reflected front brightness)
The measurement was performed using a goniophotometer (manufactured by Nippon Denshoku Industries Co., Ltd., product number: GC5000L). The incident angle of the light source was set to 45 degrees, and the reflected light intensity in the 0 degree direction was set to 100 when a standard white plate having a whiteness of 95.77 was placed on the measurement stage. At the time of measuring the sample, the incident angle of the light source was set to 15 degrees, and the intensity of the reflected light in the 0 degree direction was measured.
(Transmitted front brightness)
The measurement was performed using a goniophotometer (manufactured by Nippon Denshoku Industries Co., Ltd., product number: GC5000L). The incident angle of the light source was set to 0 degree, and the transmitted light intensity in the 0 degree direction was 100 when nothing was placed on the measurement stage. In the sample measurement, the incident angle of the light source was set to 15 degrees, and the intensity of the transmitted light in the 0 degree direction was measured.

(Support)
The support is for supporting the glass composite. The support may be any one that does not impair the transmission visibility of the transparent screen and the desired optical characteristics, and examples thereof include a transparent partition, a glass window, a head-up display for passenger cars, and a wearable display.

<Vehicle parts>
A vehicle member according to the present invention comprises the above glass composite or transparent screen. Examples of vehicle members include windshields and side windows. By providing the above-mentioned glass composite or transparent screen in the vehicle member, it is possible to display a clear image on the vehicle member without providing a separate screen.

<Building materials>
A building member according to the present invention comprises the above glass composite or transparent screen. Examples of the building member include a window glass of a house, a convenience store and a glass wall of a roadside store. Since the building member is provided with the above glass composite or transparent screen, a clear image can be displayed on the building member without providing a separate screen.

<Video projection system>
An image projection system according to the present invention comprises the above-mentioned glass composite or a see-through reflective screen, and a projection device. The projection device is not particularly limited as long as it can project an image on the screen, and for example, a commercially available front projector can be used.

A schematic diagram of one embodiment of the transparent screen and the image projection system according to the present invention is shown in FIG. The transparent screen 23 includes a transparent partition (support) 22 and a glass composite laminate 21 on the side of the viewer 24 on the transparent partition 22. The glass composite laminate 21 may include an adhesive layer for attachment to the transparent partition 22. In the case of a transmissive screen, the image projection system includes a transparent screen 23 and a projection device 25A installed on the opposite side (back side) of the viewer 24 with respect to the transparent partition 22. The projection light 26A emitted from the projection device 25A enters from the back side of the transparent screen 23 and is anisotropically scattered by the transparent screen 23, so that the viewer 24 can visually recognize the scattered light 27A. In the case of a reflective screen, the image projection system includes a transparent screen 23 and a projection device 25B installed on the same side (front side) as the viewer 24 with respect to the transparent partition 22. The projection light 26B emitted from the projection device 25B enters from the front side of the transparent screen 23 and is anisotropically scattered by the transparent screen 23, so that the viewer 24 can visually recognize the scattered light 27B.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

In Examples and Comparative Examples, various physical properties and measuring methods for performance evaluation are as follows.
(1) Haze Using a turbidimeter (manufactured by Nippon Denshoku Industries Co., Ltd., product number: NDH-5000), a haze of a glass composite laminate (with a quartz glass substrate) described below in accordance with JIS K7136. Was measured. Further, the haze of only the quartz glass used as the substrate was measured, and the haze of the glass composite was calculated by subtracting the haze value of the quartz glass substrate from the haze value of the laminated body of glass composites (with the quartz glass substrate). (Since the haze value of the glass plate is almost 0, it does not substantially affect the haze value of the glass composite).
(2) Total light transmittance Using a turbidimeter (manufactured by Nippon Denshoku Industries Co., Ltd., product number: NDH-5000), in accordance with JIS K7361-1, a laminate of glass composites (with a quartz glass substrate) ) Was measured for total light transmittance.
(3) Diffusive Transmittance Using a turbidimeter (manufactured by Nippon Denshoku Industries Co., Ltd., product number: NDH-5000), a laminate of glass composites (with a quartz glass substrate) in accordance with JIS K7361-1 The diffuse transmittance was measured.
(4) Reflective frontal light intensity It was measured using a goniophotometer (manufactured by Nippon Denshoku Industries Co., Ltd., product number: GC5000L). The incident angle of the light source was set to 45 degrees, and the reflected light intensity in the 0 degree direction was set to 100 when a standard white plate having a whiteness of 95.77 was placed on the measurement stage. At the time of measuring the sample, the incident angle of the light source was set to 15 degrees, and the intensity of the reflected light in the 0 degree direction was measured.
(5) Transmitted frontal light intensity Measurement was performed using a goniophotometer (manufactured by Nippon Denshoku Industries Co., Ltd., product number: GC5000L). The incident angle of the light source was set to 0 degree, and the transmitted light intensity in the 0 degree direction was 100 when nothing was placed on the measurement stage. In the sample measurement, the incident angle of the light source was set to 15 degrees, and the intensity of the transmitted light in the 0 degree direction was measured.
(6) Viewing angle It was measured using a goniophotometer (manufactured by Nippon Denshoku Industries Co., Ltd., product number: GC5000L). The incident angle of the light source was set to 0 degree, and the transmitted light intensity in the 0 degree direction was 100 when nothing was placed on the measurement stage. At the time of measuring the sample, the transmitted light intensity from -85 degrees to +85 degrees was measured in steps of 1 degree while the incident angle of the light source was 0 degree. The viewing angle was defined as the range in which the transmitted light intensity was 0.001 or more in the measurement range.
(7) Regular reflectance A spectrocolorimeter (manufactured by Konica Minolta Co., Ltd., product number: CM-3500d) was used to measure the glittering flaky fine particles dispersed in an appropriate solvent (water or methyl ethyl ketone) on a slide glass. The coated glass plate was coated and dried to give a film thickness of 0.5 mm or more, and light was incident on the coating film from the glass surface at an angle of 45 degrees with respect to the normal to the glass surface. The regular reflectance at that time was measured.
(8) Image clarity Image clarity (% when measured with an optical comb width of 0.125 mm, using an image clarity measuring device (manufactured by Suga Test Instruments Co., Ltd., product number: ICM-1T) according to JIS K7374. ) Was defined as the image clarity. The larger the value of the image definition, the higher the transmission image clarity.
(9) Scratch hardness JIS-K5600-5-4 The scratch hardness method was used to evaluate the hardness of the glass composite.
(10) Screen performance A mobile LED mini manufactured by Onkyo Digital Solutions Co., Ltd. was added to the glass composite body produced as a transparent screen below from a position 50 cm away from the normal direction of the glass composite body at an angle of 15 degrees. The image was projected using the projector PP-D1S. Next, after adjusting the focus knob of the projector so that the focus is on the screen surface, visually observing the image projected on the glass composite from two places, 1 m in front and 1 m in the rear of the glass composite. It was visually evaluated based on the following criteria. The performance as a reflective screen can be evaluated by observing from the front of the screen, and the performance as a transmissive screen can be evaluated by observing from the back.
[Evaluation criteria]
A: The image could be visually recognized extremely clearly.
◯: The image was clearly visible.
Δ: The outline and hue of the image were slightly blurred and visually recognized.
X: The outline of the image was blurred and was unsuitable for use as a screen.

[Example 1]
(1) Inorganic glass solution preparation process Water glass (sodium silicate aqueous solution, Kishida Chemical Co., Ltd., trade name: water glass No. 3) was prepared as an inorganic glass material. To the water glass, 0.13 mass% of flaky aluminum fine particles A (average diameter of primary particles 1 μm, aspect ratio 25, regular reflectance 16.8%) was added as glittering flaky fine particles to sodium silicate, Further, isopropyl alcohol was added so that the concentration of sodium silicate was 20% by mass, and the mixture was stirred at 23° C. and a humidity of 45% to obtain an inorganic glass solution A.
(2) Application step A quartz glass plate (100×100×2 mm, Ya=83%, Tg=63%, T1500=59%, T850=47%, haze ratio=washed with the inorganic glass solution A as a substrate. 0%) and coated with a bar coater. A doctor blade (YOSHIMITSU SEIKI) was used as the bar coater. Although this doctor blade was designed so that the film thickness of the coating film would be 5 μm, an imide tape having a thickness of 35 μm was attached to the doctor blade so that the film thickness of the coating film was adjusted to 40 μm. A coated film was obtained.
(3) Drying Step The coated glass plate was heat-treated at 100° C. for 10 minutes on a hot plate to dry the coating film. The film thickness after drying was 7 μm.
(4) Curing Step The coating film obtained in the drying step is dried at room temperature and further heated and dried in a drying oven at 250° C. for 10 minutes to provide a glass composite and a substrate (quartz glass plate). A laminate of glass composites was formed. When the cross section was confirmed with a transmission electron microscope (TEM), the thickness of the obtained glass composite was 5 μm.
(5) Evaluation of transparent screen When the produced glass composite laminate was directly used as a transparent screen, the haze value was 4.7%, the diffuse transmittance was 4.1%, and the total light transmittance was It was 88.1%, the image clarity was 91%, the scratch hardness was 6H, and it had high transparency and scratch resistance.
In addition, the transmitted front luminous intensity (×1000) measured by the goniophotometer was 1.08, and it was found that the transmitted front luminous intensity was excellent. The reflected front luminous intensity measured by the goniophotometer was 9.6, and it was found that the reflected front luminous intensity was excellent. The viewing angle measured with a goniophotometer was ±16 degrees, which proved to be excellent in viewing angle characteristics. Further, the surface on which the glass composite was formed was hard to be attached with fingerprints, and even if the fingerprints were attached, it could be easily wiped off. Further, when the screen performance was evaluated, it was possible to visually recognize a clear image both in the front observation and the rear observation, and particularly in the front observation.

[Example 2]
(1) Inorganic glass solution preparation step A liquid prepared by mixing 530 parts by mass of ethanol, 45 parts by mass of water, and 0.2 parts by mass of concentrated hydrochloric acid was added with 54.3 parts by mass of tetraethoxysilane (TEOS) as a sol-gel material and methyltriethoxy. 45.7 parts by weight of silane (MTES) was added dropwise, and 0.70% by weight of flaky aluminum fine particles A as glittering flaky fine particles was added to the total mass of TEOS and MTES. % For 2 hours to obtain an inorganic glass solution B.
(2) Coating Step In the same manner as in Example 1, the inorganic glass solution B was applied as a base material onto a washed quartz glass plate to obtain a coating film having a thickness of 10 μm.
(3) Drying Step The coating film obtained in the above step was dried at room temperature, and further dried at 40° C. for 20 minutes and at 80° C. for 10 minutes.
(4) Curing Step The coating film obtained in the drying step is held at 300° C. for 1 hour using an oven under a nitrogen atmosphere, and a glass composite body including a glass composite body and a base material (quartz glass plate). A laminated body of was obtained. The film thickness of the glass composite after curing was 2 μm.
(5) Evaluation of transparent screen The produced glass composite laminate was directly used as a transparent screen. The haze value was 17.7%, the diffuse transmittance was 13.2%, and the total light transmittance was It was 74.7%, the image clarity was 86%, the scratch hardness was 7H, and it had sufficient transparency and high scratch resistance.
The transmitted front luminous intensity (×1000) measured with a goniophotometer was 3.57, and it was found that the transmitted front luminous intensity (×1000) was excellent. The reflected front luminous intensity measured by the goniophotometer was 32.7, and it was found that the reflected front luminous intensity was excellent. The viewing angle measured with a goniophotometer was ±28 degrees, and it was found that the viewing angle characteristics were excellent. Moreover, as a result of visually evaluating the visibility, it was possible to visually recognize the image clearly. Further, the surface on which the glass composite was formed was hard to be attached with fingerprints, and even if the fingerprints were attached, it could be easily wiped off. Further, when the screen performance was evaluated, it was possible to visually recognize a clear image both in the front observation and the rear observation, and particularly in the front observation.

[Example 3]
(1) Inorganic glass solution preparation process For lead borosilicate glass frits (low softening point glass consisting of 78% by mass of PbO, 10% by mass of SO ₂ , and 12% by mass of Ba ₂ O ₃ ) substantially spherical fine particles As zirconium oxide (manufactured by Kanto Denka Kogyo Co., Ltd., primary particle median diameter 10 nm, refractive index 2.40) was added in an amount of 0.15% by mass and pine oil was added in an amount of 10% by mass, and kneaded to prepare a paste. Inorganic glass solution C was prepared by mixing isopropyl alcohol so that the lead borosilicate glass frit) concentration in the paste was 20% by mass, and dispersing with a dissolver.
(2) Coating Step The inorganic glass solution C was coated on a washed quartz glass plate as a base material using a dip coating method to obtain a coating film having a film thickness of 120 μm.
(3) Drying Step The coated film was dried at 200° C. for 15 minutes to remove isopropyl alcohol.
(4) Curing Step By sintering the coating film obtained in the drying step at 580° C. for 20 minutes, a glass composite including a glass composite (glass composite) and a substrate (quartz glass plate) is obtained. A laminate was prepared. The thickness of the obtained glass composite was 100 μm.
(5) Evaluation of transparent screen When the produced glass composite laminate was directly used as a transparent screen, the haze value was 10.2%, the diffuse transmittance was 9.0%, and the total light transmittance was It was 88.7%, the image clarity was 92%, the scratch hardness was 7H, and it had high transparency and scratch resistance.
The transmitted front luminous intensity (×1000) measured with a goniophotometer was 2.66, which proved to be excellent in the transmitted front luminous intensity. The reflected front luminous intensity measured by the goniophotometer was 1.2, and it was found that the reflected front luminous intensity was excellent. The viewing angle measured with a goniophotometer was ±22 degrees, which proved to be excellent in viewing angle characteristics. Further, the surface on which the glass composite was formed was hard to be attached with fingerprints, and even if the fingerprints were attached, it could be easily wiped off. Further, when the screen performance was evaluated, it was possible to visually recognize a clear image both in the forward observation and the backward observation, and particularly in the backward observation.

[Example 4]
In the step (1) of preparing an inorganic glass solution in Example 1, instead of the flaky aluminum fine particles A, titanium oxide (TiO ₂ ) coated mica (manufactured by Topy Industries, Ltd., trade name: HeliosR10S, average diameter of primary particles 12 μm) A glass composite (thickness 20 μm) and a substrate (quartz glass plate) were prepared in the same manner as in Example 1 except that 0.03% by mass of aspect ratio 80 and regular reflectance 16.5% was used. A laminate of glass composites was produced.
When the produced glass composite laminate was directly used for a transparent screen, the haze value was 3.2%, the diffuse transmittance was 3.0%, and the total light transmittance was 92.3%. The image clarity was 90%, the scratch hardness was 6H, and it had high transparency and scratch resistance.
The transmitted front luminous intensity (×1000) measured with a goniophotometer was 0.56, and it was found that the transmitted front luminous intensity was excellent. The reflected front luminosity measured with a goniophotometer was 5.5, and it was found that the reflected front luminosity was excellent. The viewing angle measured with a goniophotometer was ±12 degrees, which proved to be excellent in viewing angle characteristics. Further, the surface on which the glass composite was formed was hard to be attached with fingerprints, and even if the fingerprints were attached, it could be easily wiped off. Furthermore, when the screen performance was evaluated, a clear image could be visually recognized at the time of forward observation, but the outline and hue of the image were slightly blurred at the time of backward observation.

[Example 5]
In (1) Inorganic glass material solution preparation step of Example 1, instead of the flaky aluminum fine particles A, flaky aluminum fine particles B (average diameter of primary particles: 10 μm, aspect ratio: 300, regular reflectance: 62.8%) were used. A glass including a glass composite (thickness 20 μm) and a substrate (quartz glass plate) in the same manner as in Example 1 except that 0.03% by mass and 0.6% by mass of zirconium oxide as substantially spherical fine particles were added. A composite laminate was prepared.
When the produced glass composite laminate was directly used for a transparent screen, the haze value was 12.1%, the diffuse transmittance was 10.7%, and the total light transmittance was 88.5%. The image clarity was 85%, the scratch hardness was 6H, and it had high transparency and scratch resistance.
The transmitted front luminous intensity (×1000) measured by a goniophotometer was 13.62, and it was found that the transmitted front luminous intensity was excellent. The reflected front luminous intensity measured by a goniophotometer was 3.5, and it was found that the reflected front luminous intensity was excellent. The viewing angle measured with a goniophotometer was ±26 degrees, which proved to be excellent in viewing angle characteristics. Further, the surface on which the glass composite was formed was hard to be attached with fingerprints, and even if the fingerprints were attached, it could be easily wiped off. Furthermore, when the screen performance was evaluated, an extremely clear image could be visually recognized both in the front observation and in the rear observation.

[Example 6]
In the step (1) of preparing an inorganic glass solution of Example 3, titanium oxide (trade name: MT-01, trade name: MT-01, refractive index 2.72, median diameter of primary particle: 10 nm) was used instead of zirconium oxide. A glass composite laminate including a glass composite (thickness: 5000 μm) and a substrate (quartz glass plate) was produced in the same manner as in Example 3 except that 0.003% by mass was added and the coating step was repeated 50 times. did.
Using the produced glass composite laminate as it was as a transparent screen, the haze value was 9.1%, the diffuse transmittance was 7.7%, and the total light transmittance was 84.2%. The image clarity was 88%, the scratch hardness was 7H, and it had high transparency and scratch resistance.
The transmitted front luminous intensity (×1000) measured by the goniophotometer was 3.12, which proved to be excellent in the transmitted front luminous intensity. The reflected front luminous intensity measured by the goniophotometer was 2.3, and it was found that the reflected front luminous intensity was excellent. The viewing angle measured with a goniophotometer was ±24 degrees, which proved to be excellent in viewing angle characteristics. Further, the surface on which the glass composite was formed was hard to be attached with fingerprints, and even if the fingerprints were attached, it could be easily wiped off. Further, when the screen performance was evaluated, it was possible to visually recognize a clear image both in the forward observation and the backward observation, and particularly in the backward observation.

[Example 7]
In the inorganic glass material solution preparation step (1) of Example 1, 0.85 of silver fine particles (average diameter of primary particles: 1 μm, aspect ratio: 200, regular reflectance: 32.8%) was replaced by 0.85 instead of the flaky aluminum fine particles A. A glass composite laminate including a glass composite (thickness: 20 μm) and a base material (quartz glass plate) was produced in the same manner as in Example 1 except that the addition of mass% was performed.
When the produced glass composite laminate was directly used for a transparent screen, the haze value was 5.4%, the diffuse transmittance was 3.8%, and the total light transmittance was 70.1%. The image clarity was 75%, the scratch hardness was 6H, and it had high transparency and scratch resistance.
The transmitted front luminous intensity (×1000) measured by a goniophotometer was 1.32, and it was found that the transmitted front luminous intensity was excellent. The reflected front luminosity measured with a goniophotometer was 13.8, and it was found that the reflected front luminosity was excellent. The viewing angle measured with a goniophotometer was ±15°, which proved to be excellent in viewing angle characteristics. Further, the surface on which the glass composite was formed was hard to be attached with fingerprints, and even if the fingerprints were attached, it could be easily wiped off. Further, when the screen performance was evaluated, it was possible to visually recognize a clear image both in the front observation and the rear observation, and particularly in the front observation.

[Example 8]
In the same manner as in Example 3, except that zirconium oxide was not added and 0.002% by mass of the flaky aluminum fine particles A was added as the bright flaky fine particles in the inorganic glass solution preparation step of Example 3 A glass composite laminate including a glass composite (thickness 80 μm) and a substrate (quartz glass plate) was prepared.
Using the produced glass composite laminate as it was as a transparent screen, the haze value was 2.0%, the diffuse transmittance was 1.8%, and the total light transmittance was 90.1%. The image clarity was 84%, the scratch hardness was 7H, and it had high transparency and scratch resistance.
The transmitted front luminous intensity (×1000) measured by the goniophotometer was 0.81 and it was found that the transmitted front luminous intensity was excellent. The reflected front luminosity measured by the goniophotometer was 5.2, and it was found that the reflected front luminosity was excellent. The viewing angle measured with a goniophotometer was ±15°, which proved to be excellent in viewing angle characteristics. Further, the surface on which the glass composite was formed was hard to be attached with fingerprints, and even if the fingerprints were attached, it could be easily wiped off. Further, when the screen performance was evaluated, it was possible to visually recognize a clear image both in the front observation and the rear observation, and particularly in the front observation.

[Comparative Example 1]
Instead of the water glass aqueous solution used in (1) Inorganic glass solution manufacturing process of Example 1, an acrylic solution (trade name: Acrypet VH, manufactured by Mitsubishi Rayon Co., Ltd.) was dissolved in toluene to 20% by mass. Zirconium oxide was added to the acrylic resin in an amount of 0.60 mass% instead of the flaky aluminum fine particles A, and the mixture was stirred at 23° C. and a humidity of 45% for 5 hours to obtain a fine particle-dispersed acrylic solution.
(2) Coating Step In the same manner as in Example 1, the fine particle-dispersed acrylic solution was coated on a cleaned quartz glass plate as a substrate to obtain a coating film having a thickness of 12 μm.
(3) Drying Step The coating film obtained in the above step was dried at room temperature, further dried at 40° C. for 20 minutes, at 80° C. for 1 hour, and under reduced pressure for 12 hours. The film thickness of the fine particle-dispersed acrylic layer after drying was 3 μm.
(4) Evaluation of transparent screen When the produced laminate of the fine particle-dispersed acrylic layer and the quartz glass substrate was directly used as a transparent screen, the haze value was 12.2% and the diffuse transmittance was 10.3%. The total light transmittance was 84.8%, the image clarity was 84%, the scratch hardness was 3B, and the film was transparent, but the scratch resistance was poor. Further, the transmitted front luminous intensity (×1000) measured with a goniophotometer was 2.54, the reflected front luminous intensity was 1.1, and the viewing angle was ±20°. Further, fingerprints were easily attached to the surface on which the fine particle dispersed acrylic layer was formed, and the attached fingerprints could not be easily wiped off. Further, when the screen performance was evaluated, it was possible to visually recognize a clear image both in the forward observation and the backward observation, and particularly in the backward observation.

[Comparative example 2]
A fine particle-dispersed acrylic layer was produced in the same manner as in Comparative Example 1 except that 0.03% by mass of aluminum fine particles A was added to the acrylic resin pellets instead of zirconium oxide. When the produced laminate of the fine particle-dispersed acrylic layer and the quartz glass substrate was directly used as a transparent screen, the haze value was 4.7%, the diffuse transmittance was 4.1%, the total light transmittance was 88.1%, The image clarity was 88% and the scratch hardness was 3B. Although it was transparent, the scratch resistance was poor. Further, the transmitted front luminous intensity (×1000) measured with a goniophotometer was 1.02, the reflected front luminous intensity was 9.6, and the viewing angle was ±16°. Further, fingerprints were easily attached to the surface on which the fine particle dispersed acrylic layer was formed, and the attached fingerprints could not be easily wiped off. Further, when the screen performance was evaluated, it was possible to visually recognize a clear image both in the front observation and the rear observation, and particularly in the front observation.

[Comparative Example 3]
In Comparative Example 1, instead of zirconium oxide, mica particles (manufactured by Yamaguchi Mica Co., Ltd., trade name: A-21S, average particle diameter 23 μm, aspect ratio 70, positive) A fine particle-dispersed acrylic layer was produced in the same manner as in Comparative Example 1 except that 0.20% by mass of the reflectance of 9.8% was added to the acrylic resin pellet. When the produced laminate of the fine particle-dispersed acrylic layer and the quartz glass substrate was directly used as a transparent screen, the haze value was 0.5%, the diffuse transmittance was 0.4%, and the total light transmittance was 88.3%. The image clarity was 70% and the scratch hardness was 3B, and although it was transparent, the scratch resistance was poor. Further, the transmitted front luminous intensity (×1000) measured by a goniophotometer is 0.00, the reflected front luminous intensity is 0.0, the viewing angle is ±6°, the transmitted front luminous intensity, the reflected Both the front luminous intensity and the viewing angle were inferior. It was. Further, fingerprints were easily attached to the surface on which the fine particle dispersed acrylic layer was formed, and the attached fingerprints could not be easily wiped off. Furthermore, when the screen performance was evaluated, the outline of the image was blurred during forward observation, which was unsuitable for use as a screen, and the outline and hue of the image were visually blurred during backward observation.

Table 3 shows the details of the glass composite or the fine particle-dispersed acrylic layer used in Examples and Comparative Examples.

Table 4 shows various physical properties and results of performance evaluation of the transparent screens (glass composite laminate or fine particle dispersed acrylic layer laminate) used in Examples and Comparative Examples.

10 Inorganic glass 11 Bright flaky fine particles 12 Approximately spherical fine particles 13 Glass composite 14 Base material 15, 21 Laminate of glass composite 16, 17, 26A, 26B Projected light 18, 27A, 27B Scattered light 19, 24 Viewer 22 Transparent partition (support)
23 Transparent screen 25A, 25B Projector

Claims (18)

A glass composite for a transparent screen, comprising an inorganic glass and glittering flaky fine particles and substantially spherical fine particles mixed in the inorganic glass, and having a haze value of 50% or less. The glass composite according to claim 1, wherein an average diameter of primary particles of the glittering flaky fine particles is 0.01 to 100 µm. The glass composite according to claim 1, wherein the glittering flaky fine particles have a regular reflectance of 12% or more. The glass composite according to any one of claims 1 to 3, wherein the glittering flaky fine particles have an average aspect ratio of 3 to 800. The glittering flaky fine particles are a metal selected from the group consisting of aluminum, silver, copper, platinum, gold, titanium, nickel, tin, tin-cobalt alloy, indium, chromium, titanium oxide, aluminum oxide, and zinc sulfide. 5. A glittering material in which a systematic particle, glass is coated with a metal or a metal oxide, or a glittering material in which natural mica or synthetic mica is coated with a metal or a metal oxide. Glass complex. The glass composite according to any one of claims 1 to 5, wherein the inorganic glass is at least one selected from the group consisting of water glass, a sol-gel material, and a glass material having a softening temperature of 150 to 650°C. body. The glass composite according to any one of claims 1 to 6, wherein the content of the bright flaky fine particles is 0.0001 to 5.0 mass% with respect to the inorganic glass. The difference between the refractive index n ₂ of the substantially spherical fine particles and the refractive index n ₁ of the inorganic glass is represented by the following mathematical formula (1):
|n ₁ −n ₂ |≧0.1 (1)
The glass composite according to any one of claims 1 to 7 , which satisfies the above condition. The substantially spherical particles, zirconium oxide, zinc oxide, titanium oxide, cerium oxide, barium titanate, and is at least one selected from the group consisting of strontium titanate, in any one of claims 1-8 The glass composite described. The median diameter of the primary particles of the substantially spherical particles, is 0.1 to 100 nm, a glass composite according to any one of claims 1-9. Said generally the content of the spherical fine particles, the inorganic is 0.0001 to 2.0 wt% with respect to the glass, the glass composite according to any one of claims 1 to 10. Is for transmission transparent screen for or reflective transparent screen, glass composite according to any one of claims 1 to 11. And glass composite according to any one of claims 1 to 12 and a base material, a laminate of glass composite. Claims comprising a stack of glass composite according to glass composite or claim 13 according to any one of claims 1 to 12, transmission transparent screen. Claims comprising a stack of glass composite according to glass composite or claim 13 according to any one of claims 1 to 12, the reflection type transparent screen. Glass composite according to any one of claims 1 to 12 laminates of the glass composite according to claim 13, the reflection type according to a transmission type transparent screen according to claim 14 or claim 15, A vehicle member having a transparent screen. Glass composite according to any one of claims 1 to 12 laminates of the glass composite according to claim 13, the reflection type according to a transmission type transparent screen according to claim 14 or claim 15, Building material with a transparent screen. Glass composite according to any one of claims 1 to 12 laminates of the glass composite according to claim 13, the reflection type according to a transmission type transparent screen according to claim 14 or claim 15, An image projection system including a transparent screen and a projection device.