JP2012212092A - Transmission type transparent screen and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission type transparent screen satisfying both of high transparency and visibility of an image in projection of a projector, and to provide a manufacturing method thereof.SOLUTION: In the transmission type transparent screen, light-diffusion fine particles are two-dimensionally disposed at least on one surface of a light transmission support. The transmission type transparent screen is formed by applying a porous layer coating liquid that includes inorganic fine particles with an average secondary particle size of 500 nm or less, and resin binder, on the one surface, and after a falling-drying-rate period in a drying process or after finishing the drying, applying a coating liquid including light-diffusion fine particles with a void volume of the porous layer or less by a preliminary measurement type coating method and drying it.

Description

  The present invention relates to a rear projection type transmissive screen in which an image projected from a projector can be viewed from the opposite side of the projector across the screen, and has a low haze and excellent transparency, and an image projected from the projector The present invention relates to a see-through transmissive screen having excellent visibility and a plate making method thereof.

  At present, so-called rear projection type transmission screens, in which the image projected from the projector is viewed from the opposite side of the projector across the screen, are becoming popular in place of advertising media such as posters, signs, signboards, etc. There is no need to re-paste, and the content can be changed immediately, and digital content that is not only static but also dynamic advertisement can be projected as it is on a large screen as digital signage.

  This rear projection type transmission screen generally uses a polarizing film, a Fresnel lens sheet, a lenticular lens sheet or the like (for example, Patent Document 1), and has high brightness, high contrast, and very high visibility. Although expensive, it was very expensive and it was almost impossible to see through the screen. A screen using light-transmitting beads having high brightness and high contrast (for example, Patent Document 2) has also been proposed. However, since the screen itself is also opaque, it is similarly impossible to see through the other side of the screen. It was impossible.

  On the other hand, most of the shop's show windows face the road where customers pass, and if you can not only see the products in the shop through the window but also replace the window with digital signage if necessary, you can advertise Since it is very useful as a medium, there is an increasing need for a see-through transmissive screen with a show window attached type.

  As such a transparent transmission screen, the transparent binder and the average particle diameter of 1.0 to 10 μm and the relative refractive index n with respect to the refractive index of the transparent binder are 0.91 <n <1.09 (where n It has been proposed to provide a light scattering layer containing spherical fine particles satisfying ≠ 1) (for example, Patent Documents 3 and 4).

  However, it is difficult to sufficiently satisfy both the transparency and the visibility of the image at the time of projection by the projector, and further improvement has been demanded.

Japanese Patent Laid-Open No. 6-165095 International Publication No. 99/050710 Pamphlet Japanese Patent No. 3993980 Japanese Patent No. 4129275

  An object of the present invention is to provide a transmissive screen capable of see-through excellent in see-through and visibility of an image when projected by a projector, and a method for manufacturing the same.

The object is achieved by the following invention.
(1) A see-through transmissive screen in which light diffusing fine particles are two-dimensionally arranged on at least one surface of a light transmissive support.
(2) The above light-transmitting support is a support having a porous layer containing inorganic fine particles having an average secondary particle diameter of 500 nm or less and a resin binder on at least one surface of a light-transmitting substrate. The see-through transmissive screen according to (1).
(3) The see-through transmissive screen according to (1) or (2) above, wherein the light diffusing fine particles have an average particle diameter of 0.15 to 2.75 μm.
(4) The see-through transmissive screen according to any one of (1) to (3), wherein the light diffusing fine particles have an average particle size of 0.35 to 0.80 μm.
(5) A porous layer coating solution containing inorganic fine particles having an average secondary particle size of 500 nm or less and a resin binder is applied to at least one surface of the light-transmitting substrate, and after the decreasing rate drying region during the drying process Alternatively, after the drying is finished, a coating liquid containing light diffusing fine particles is applied by a pre-weighing type coating method with a void volume of the porous layer or less, and dried. Method.

  According to the present invention, it is possible to provide a see-through transmissive screen excellent in see-through property and visibility of an image when projected by a projector, and a manufacturing method thereof.

Schematic sectional view showing an embodiment of the see-through transmissive screen of the present invention Schematic sectional view showing another embodiment of the transmissive screen of the present invention Schematic sectional view showing another embodiment of the transmissive screen of the present invention Schematic sectional view showing another embodiment of the transmissive screen of the present invention Schematic sectional view showing a conventional example of a transmissive screen that can be seen through

  The present invention is described in detail below.

  The see-through transmissive screen of the present invention is characterized in that light diffusing fine particles are two-dimensionally arranged on at least one surface of a light transmissive support. In the present invention, “perspective view” means that the haze of the entire screen is 60% or less.

The haze is a value defined below in JIS-K7105, and the lower the value, the better the transparency.
H = (Td / Tt) × 100 (%)
H: Haze Td: Diffuse light transmittance Tt: Parallel light transmittance

  1 to 4 are schematic cross-sectional views showing one embodiment or other embodiments of the see-through transmissive screen of the present invention, and FIG. 5 is a schematic cross-sectional view of a conventional see-through transmissive screen. Show. The two-dimensional arrangement in the present invention is a conventional diffusion layer structure (hereinafter referred to as a three-dimensional arrangement layer) in which a plurality of light diffusing fine particles 2 are overlapped in the Z-axis direction (depth direction) and connected with a binder or the like as shown in FIG. 1), for example, as shown in FIG. 1, the light diffusing fine particles 2 are arranged individually in a two-dimensional plane without overlapping in the Z-axis direction, and do not form a layer structure in which the light diffusing fine particles 2 are connected by a resin binder or the like. That means.

  Usually, when the light diffusing fine particles are applied to a light transmissive support such as a film, a binder for binding the light diffusing fine particles is required. In general, the coating liquid containing the light diffusing fine particles and the binder is diluted with an organic solvent or water for the purpose of adjusting the viscosity for ensuring coating properties, and is applied to the light-transmitting support and dried. However, in order to obtain a uniform coated surface, it is necessary to apply with a wet coating thickness equal to or larger than the diameter of the light diffusing fine particles, and as a result, the light diffusing fine particles are configured as a three-dimensional arrangement layer instead of a two-dimensional arrangement. The On the other hand, the see-through transmissive screen of the present invention can achieve both high transparency and image visibility at the time of projector projection by arranging such light diffusing fine particles in two dimensions. It becomes possible.

  As a method for obtaining the two-dimensional arrangement of the light diffusing fine particles of the present invention, for example, after applying and drying the adhesive layer 6 on the light-transmitting substrate 5, or attaching a double-sided adhesive tape, peeling the separate paper, and sticking After exposing the layer 6, there is a method in which the light diffusing fine particles 2 are sprayed and sprayed to adhere to the adhesive layer 6. From the viewpoint of productivity and uniform arrangement of the light diffusing fine particles, at least the light transmissive substrate is used. On one side, a porous layer coating liquid containing inorganic fine particles having an average secondary particle size of 500 nm or less and a resin binder is applied, and light diffusing fine particles are contained after the decreasing rate drying region during the drying process or after the drying is completed. A coating solution (hereinafter referred to as a light diffusing fine particle coating solution) is preferably applied by a pre-measuring type coating method with a void volume of the porous layer or less and dried. The structure of the transmission screen obtained by the former corresponds to the schematic sectional view of FIG. 3, and the structure of the transmission screen obtained by the latter corresponds to the schematic sectional view of FIG.

  By such a manufacturing method, the light diffusing fine particle coating liquid is instantaneously absorbed by the porous layer, and the light diffusing fine particles that have overlapped at the time of application do not overlap on the porous layer due to the flow rate and suction pressure of the coating liquid at that time The two-dimensional arrangement is tightly pressed and bonded. In addition, when a resin binder is contained in the coating liquid for binding of light diffusing fine particles, the resin binder works effectively in the vicinity of the contact surface with the light diffusing fine particles on the porous layer. The non-porous layer portion is completely absorbed in the porous layer, and as a result, it is two-dimensionally arranged without forming the layer structure in which the light diffusing fine particles are connected with the resin binder described above. Moreover, the transparency of the transmission screen is improved by such a porous layer.

  After applying the porous layer coating solution, in a state where the gap is not sufficiently formed, for example, applying the light diffusing fine particle coating solution in a constant rate drying region, or simultaneous multilayer coating of the porous layer coating solution and the light diffusing fine particle coating solution In some cases, the light diffusing fine particles form a three-dimensional arrangement layer, so that sufficient transparency cannot be obtained. In addition, when coating is performed in an amount exceeding the void volume of the porous layer, the coating solution that has not been absorbed in the porous layer remains on the surface, resulting in the same situation as the simultaneous multilayer coating, and the light diffusing fine particles are arranged in the three-dimensional arrangement layer. In some cases, sufficient transparency cannot be obtained. Further, it is not preferable because bubbles in the porous layer are generated on the wet film of the light diffusing fine particle coating solution and the surface quality is significantly deteriorated.

  The light diffusing fine particle coating solution may be applied after the reduction rate drying region, but also in the reduction rate drying region, the void volume of the porous layer at the time of the drying process increases as the drying process proceeds. The larger the void volume of the porous layer at the time of applying the light diffusing fine particle coating liquid, the better the two-dimensional arrangement of the light diffusing fine particles by the suction pressure described above. Even in the reduced rate drying region, it is preferably applied in the latter half, and it is more preferable to apply the light-diffusing fine particle coating solution after the drying is completed. Further, after the porous layer is applied, it may be wound up once, and then the light diffusion fine particle coating solution may be applied, or after winding, it may be applied after annealing treatment such as heating and humidity control. .

  The drying process is roughly divided into a constant rate drying region, a decreasing rate drying region, and a drying end point. In the constant rate drying region, which is the initial stage of drying, the water and solvent in the coating layer simply evaporate while taking away the latent heat of vaporization, so the surface temperature of the coating layer is the wet bulb temperature (in the equilibrium state of wet air). The temperature of the water droplet is lower, and the lower the air humidity, the lower it is.) In the rate-decreasing region, energy is required to dissociate the interaction between the substance contained in the coating layer and water, or moisture movement is inhibited by voids that begin to form. Since the movement speed of the solvent is lower than the evaporation speed of water or the solvent from the surface of the coating layer, and the latent heat of evaporation is gradually lost, the surface temperature of the coating layer becomes gradually higher than the wet bulb temperature. Since the latent heat of vaporization is not lost at the end of drying, the surface temperature of the coating layer becomes equal to the temperature of the dry air. Therefore, after the decreasing rate drying region in the present invention, the surface temperature of the coating layer is compared with the wet bulb temperature under the same conditions using a surface thermometer during the drying step, and the region after the region where the surface temperature is higher than the wet bulb temperature. That is.

  The void volume of the porous layer referred to in the present invention is the cumulative value from 3 nm to 400 nm of pore radius in the porous layer portion measured and processed using a mercury porosimeter (measuring instrument name Autopore II 9220 manufacturer micromeritics instrument corporation). By multiplying the pore volume (ml / g) by the dry solid content (g / square meter) of the porous layer, it can be obtained as a numerical value per unit area (square meter).

  The wet coating amount of the light diffusing fine particle coating solution is preferably not more than the void volume of the porous layer, more preferably not more than 90% by mass, particularly preferably not more than 85% by mass with respect to the void volume in the porous layer. .

  A pre-weighing type coating apparatus according to the present invention will be described. Various application methods can be roughly classified into a pre-weighing type and a post-weighing type. The pre-weighing type is a method in which a coating liquid that has been weighed so as to have a predetermined coating amount is applied. The post-weighing type is a coating method in which the coating is applied in excess of a predetermined coating amount, and then scraped to a predetermined coating amount later. Pre-weighing type application methods include slide bead method, curtain method, extrusion method, slot die method, gravure roll method, spray method, etc., and post-weighing type application methods include air knife method and blade coating method. And rod bar (wire bar) coating methods. In the gravure roll method, the coating liquid is excessively supplied onto the gravure roll, scraped off by a blade, and then transferred to a substrate for coating. Since there is no scraping step after application, it can be said to be a pre-weighing method.

  In the present invention, the light diffusing fine particle coating solution preferably uses a pre-weighing type coating device in order to give an accurate coating amount and not disturb the two-dimensional arrangement of the light diffusing fine particles in the porous layer. It is preferable to use a coating device having a slit for uniformly flowing out a coating solution in the coating width direction, such as a slot die, or a coating device using a gravure roll. When such a pre-weighing type coating apparatus is not used, the light diffusing fine particles form a three-dimensional arrangement layer, so that sufficient transparency may not be obtained.

  As the light diffusing fine particles of the present invention, any organic fine particles and inorganic fine particles can be used as long as they have the ability to diffuse light, but they do not have a secondary aggregate particle diameter from the viewpoint of transparency. It is preferable to use so-called monodispersed organic fine particles, and the shape is preferably spherical. The refractive index of the light diffusing fine particles is preferably 1.50 or more, and more preferably 1.60 or more.

  Examples of the organic fine particles used in the present invention include acrylic polymers, styrene-acrylic copolymers, vinyl acetate-acrylic copolymers, vinyl acetate polymers, ethylene-vinyl acetate copolymers, chlorinated polyolefin polymers, and ethylene. -Multi-component copolymers such as vinyl acetate-acrylic, SBR, NBR, MBR, carboxylated SBR, carboxylated NBR, carboxylated MBR, polyvinyl chloride, polyvinylidene chloride, polyester, polyolefin, polyurethane, polymethacrylate, polytetrafluoro Widely from conventionally known ones such as ethylene, polymethyl methacrylate, polycarbonate, polyvinyl acetal resin, rosin ester resin, episulfide resin, epoxy resin, silicone resin, silicone-acrylic resin, melamine resin, etc. Bukoto can. Moreover, what coat | covered fine particle surfaces, such as a melamine resin and an acrylic resin, with inorganic fine particles, such as a silica, can also be used. Further, even when composite particles composed of such organic fine particles and a small amount of inorganic fine particles (in which the proportion of inorganic fine particles is less than 50% by mass) are used, it can be substantially regarded as organic fine particles and used. Those in which a sulfur atom is introduced into the monomer of these polymers for the purpose of increasing the refractive index, and those in which a fluorine substituent is introduced to improve the weather resistance or lower the refractive index can also be used.

  The inorganic fine particles used in the present invention include silica, alumina, rutile titanium dioxide, anatase titanium dioxide, zinc oxide, zinc sulfide, lead white, antimony oxides, zinc antimonate, lead titanate, potassium titanate, zirconium oxide. , Oxide glass such as cerium oxide, hafnium oxide, tantalum pentoxide, niobium pentoxide, yttrium oxide, chromium oxide, tin oxide, molybdenum oxide, ATO, ITO, silicate glass, phosphate glass, borate glass These composite oxides or composite sulfides can be widely used. In the case of inorganic fine particles having photocatalytic activity, such as titanium oxide and zinc oxide, those having a very thin surface coated with silica, alumina, boron or the like can be used. Further, even when composite particles composed of inorganic fine particles and a small amount of organic polymer (the proportion of organic fine particles is less than 50% by mass) are used, they can be regarded as inorganic fine particles substantially.

  These organic fine particles and inorganic fine particles can be used singly or as a mixture of a plurality of kinds, and both organic fine particles and inorganic fine particles can also be mixed and used.

  In the present invention, when using light diffusing fine particles having an average particle diameter of 0.15 to 2.75 μm, particularly excellent visibility can be obtained. More preferably, it is 0.35-0.80 micrometer. The average particle diameter can be measured as a number median diameter using a laser scattering particle size distribution analyzer (for example, LA910 manufactured by Horiba, Ltd.).

  The upper limit of the coating amount for disposing the light diffusing fine particles of the present invention is an amount that is 77% or less as a projected area of the light diffusing fine particles, and more preferably an amount that is 60% or less. Further, the lower limit is an amount that becomes 5% or more, more preferably an amount that becomes 10% or more, as the projected area of the light diffusing fine particles. The projected area of the light diffusing fine particles is the total projection of the light diffusing fine particles on the field of view by taking an electron microscope image of the screen from the light diffusing fine particle side and measuring the number and size of the light diffusing fine particles in the field of view. It can be calculated from the area.

  In the light diffusing fine particle coating liquid in the present invention, a polymer resin is suitably used as a resin binder in addition to the light diffusing fine particles. Such a polymer resin is not particularly limited, but for example, a polyester resin. , Acrylic resins, acrylic urethane resins, polyester acrylate resins, polyurethane acrylate resins, epoxy acrylate resins, urethane resins, epoxy resins, polycarbonate resins, cellulose resins, acetal resins, vinyl resins, ( Light transmission of (meth) acrylic ester resin, polyethylene resin, polystyrene resin, polypropylene resin, polyamide resin, polyimide resin, melamine resin, phenol resin, silicone resin, fluorine resin, etc. Thermoplastic resin, thermosetting It may be used butter, an ionizing radiation-curable resin or the like.

  Although there is no restriction | limiting in particular in content of these resin binders, The range of 50-1500 mass% with respect to light-diffusion microparticles | fine-particles is preferable. More preferably, it is 50-1000 mass%, More preferably, it is 100-700 mass%.

  The light diffusing fine particle coating solution in the present invention further includes a cationic polymer, an antiseptic, a surfactant, a coloring dye, a coloring pigment, an ultraviolet absorber, an antioxidant, a pigment dispersant, an antifoaming agent, a leveling agent, and a fluorescence. Brightening agents, viscosity stabilizers, pH adjusters, and the like can also be added.

  Examples of inorganic fine particles having an average secondary particle diameter of 500 nm or less used in the porous layer of the present invention include various known fine particles such as amorphous synthetic silica, alumina, alumina hydrate, calcium carbonate, magnesium carbonate, titanium dioxide. Examples thereof include amorphous synthetic silica, alumina, or alumina hydrate that facilitates two-dimensional arrangement of light diffusing fine particles due to high suction pressure. A preferable average secondary particle diameter is 10 to 300 nm, and more preferably 20 to 200 nm. An average secondary particle diameter exceeding 500 nm is not preferable because sufficient transparency cannot be obtained.

  Amorphous synthetic silica can be roughly classified into wet method silica, gas phase method silica, and others depending on the production method. Wet method silica is further classified into precipitation method silica, gel method silica, and sol method silica according to the production method. Precipitated silica is produced by reacting sodium silicate and sulfuric acid under alkaline conditions, and the silica particles that have grown are agglomerated and settled, and are then commercialized through the steps of filtration, washing, drying, pulverization and classification. Precipitated silica is commercially available, for example, from Tosoh Silica Co., Ltd. as a nip seal and from Tokuyama Co., Ltd. as a Toxeal. Gel silica is produced by reacting sodium silicate and sulfuric acid under acidic conditions. During aging, the microparticles dissolve and reprecipitate so as to bind the other primary particles, so that the distinct primary particles disappear and form relatively hard aggregated particles having an internal void structure. For example, it is commercially available as nip gel from Tosoh Silica Co., Ltd., and as syloid and silo jet from Grace Japan Co., Ltd. The sol method silica is also called colloidal silica, which is obtained by heating and aging a silica sol obtained through metathesis of sodium silicate acid or the like through an ion exchange resin layer. For example, it is commercially available as Snowtex from Nissan Chemical Industries, Ltd. Yes.

  Vapor phase silica is also called a dry method as opposed to a wet method, and is generally made by a flame hydrolysis method. Specifically, a method of making silicon tetrachloride by burning with hydrogen and oxygen is generally known, but silanes such as methyltrichlorosilane and trichlorosilane can be used alone or in silicon tetrachloride instead of silicon tetrachloride. Can be used in a mixed state. Vapor phase silica is commercially available as Aerosil from Nippon Aerosil Co., Ltd. and QS type from Tokuyama Co., Ltd.

In the present invention, gas phase method silica can be preferably used. The average primary particle diameter of the vapor phase silica used in the present invention is preferably 30 nm or less, and preferably 15 nm or less in order to obtain higher transparency. More preferably, an average primary particle diameter of 3 to 15 nm (especially 3 to 10 nm) and a specific surface area by the BET method of 200 m ² / g or more (preferably 250 to 500 m ² / g) are used. The average primary particle diameter as used in the present invention is an average particle diameter obtained by measuring the diameter of a circle equal to the projected area of each of the 100 primary particles existing within a certain area by observation with an electron microscope. The BET method referred to in the present invention is one of the powder surface area measurement methods by the vapor phase adsorption method, and is a method for obtaining the total surface area, that is, the specific surface area of a 1 g sample from the adsorption isotherm. Usually, as the adsorbed gas, a large amount of nitrogen gas is used, and the most frequently used method is to measure the amount of adsorption from the pressure or volume change of the gas to be adsorbed. The most prominent expression for expressing the isotherm of multimolecular adsorption is the Brunauer, Emmett, and Teller formula, called the BET formula, which is widely used for determining the surface area. The adsorption amount is obtained based on the BET equation, and the surface area is obtained by multiplying the area occupied by one adsorbed molecule on the surface.

  Vapor phase silica is preferably dispersed in the presence of a cationic compound. The average secondary particle diameter of the dispersed vapor phase method silica is 500 nm or less, preferably 10 to 300 nm, more preferably 20 to 200 nm. As a dispersion method, gas phase method silica and a dispersion medium are premixed by ordinary propeller stirring, turbine type stirring, homomixer type stirring, etc., and then a media mill such as a ball mill, a bead mill, a sand grinder, a high pressure homogenizer, an ultrahigh pressure, etc. It is preferable to perform dispersion using a pressure disperser such as a homogenizer, an ultrasonic disperser, a thin film swirl disperser, or the like. The average secondary particle diameter as used in the present invention can be determined by photographing with a transmission electron microscope. For simplicity, a laser scattering particle size distribution meter (for example, LA910 manufactured by Horiba, Ltd.) is used. It can be measured as the number median diameter.

  In the present invention, wet process silica pulverized to an average secondary particle diameter of 500 nm or less can also be preferably used. As the wet method silica used here, precipitation method silica or gel method silica is preferable, and precipitation method silica is particularly preferable. The wet process silica particles used in the present invention are preferably wet process silica particles having an average primary particle diameter of 50 nm or less, preferably 3 to 40 nm, and an average aggregate particle diameter of 5 to 50 μm. It is preferable to use wet method silica fine particles finely pulverized to an average secondary particle diameter of 500 nm or less, preferably about 10 to 300 nm, more preferably about 20 to 200 nm in the presence of.

  A specific method for obtaining wet process silica fine particles having an average secondary particle diameter of 500 nm or less in the present invention will be described. First, silica particles and a cationic compound are mixed in a dispersion medium mainly composed of water, and at least one dispersion device such as a sawtooth blade type dispersion machine, a propeller blade type dispersion machine, or a rotor stator type dispersion machine is used. Used to obtain a preliminary dispersion. If necessary, an appropriate low boiling point solvent or the like may be added to the aqueous dispersion medium. The higher the solid content concentration of the silica pre-dispersion liquid, the more preferable, but when the concentration is too high, it becomes impossible to disperse, so the preferable range is 15 to 40% by mass, and more preferably 20 to 35% by mass. Next, the silica particles are pulverized by applying the silica pre-dispersion to mechanical means having a stronger shearing force to obtain a wet process silica fine particle dispersion having an average secondary particle size of 500 nm or less. As a mechanical means, a known method can be adopted, for example, a media mill such as a ball mill, a bead mill, a sand grinder, a high pressure homogenizer, a pressure disperser such as an ultra high pressure homogenizer, an ultrasonic disperser, a thin film swirl disperser, etc. Can be used.

  As the cationic compound used for the dispersion or pulverization of the gas phase method silica and the wet method silica, a cationic polymer can be preferably used. As the cationic polymer, polyethyleneimine, polydiallylamine, polyallylamine, alkylamine polymer, JP-A-59-20696, JP-A-59-33176, JP-A-59-33177, JP-A-59-155088, Sho 60-11389, Sho 60-49990, Sho 60-83882, Sho 60-109894, Sho 62-198493, Sho 63-49478, Sho 63-115780, Shosho 63-280681, No. 1-40371, No. 6-234268, No. 7-125411, No. 10-193976, etc. The polymer having is preferably used. In particular, diallylamine derivatives are preferably used as the cationic polymer. In terms of dispersibility and dispersion viscosity, the weight average molecular weight of these cationic polymers is preferably about 2,000 to 100,000, and particularly preferably about 2,000 to 30,000.

  As the alumina used in the present invention, γ-alumina which is a γ-type crystal of aluminum oxide is preferable, and among them, a δ group crystal is preferable. γ-alumina can make primary particles as small as about 10 nm. Usually, secondary particles of thousands to tens of thousands of nanometers are averaged by ultrasonic, high-pressure homogenizer, counter collision type jet crusher, etc. What grind | pulverized the particle diameter to 500 nm or less, Preferably about 20-300 nm can be used.

The alumina hydrate of the present invention is represented by a constitutive formula of Al ₂ O ₃ .nH ₂ O (n = 1 to 3). The alumina hydrate can be obtained by a known production method such as hydrolysis of aluminum alkoxide such as aluminum isopropoxide, neutralization of aluminum salt with alkali, hydrolysis of aluminate and the like. The average secondary particle diameter of the alumina hydrate used in the present invention is 500 nm or less, preferably 20 to 300 nm.

  The above-mentioned alumina and alumina hydrate used in the invention are used in the form of a dispersion dispersed by a known dispersant such as acetic acid, lactic acid, formic acid, nitric acid and the like.

  Two or more kinds of inorganic fine particles may be used in combination from the inorganic fine particles described above. For example, combined use of pulverized wet method silica and vapor phase method silica, combined use of finely pulverized wet method silica and alumina or alumina hydrate, and combined use of vapor phase method silica and alumina or alumina hydrate. . The ratio in the case of this combined use is preferably in the range of 7: 3 to 3: 7 in any aspect. The porous layer in the present invention means a layer formed by applying a coating solution containing the above-described inorganic fine particles with a total solid content of 50% by mass or more, more preferably 70% by mass or more. To do.

  In the present invention, as the resin binder used together with the inorganic fine particles constituting the porous layer, the same resin binder as that of the coating liquid having the light diffusing fine particles described above can be used, but hydrophilicity is high in transparency. A binder is preferably used. For example, polyvinyl alcohol, gelatin, polyethylene oxide, polyvinyl pyrrolidone, polyacrylic acid, polyacrylamide, polyurethane, dextran, dextrin, carrageenan (κ, ι, λ, etc.), agar, pullulan, water-soluble polyvinyl butyral, hydroxyethylcellulose, carboxymethylcellulose Etc. Two or more of these hydrophilic binders can be used in combination. When using a hydrophilic binder, it is important that the hydrophilic binder does not swell during the initial penetration of the ink and block the voids. From this point of view, a hydrophilic binder having a relatively low swellability around room temperature is preferable. Used. Preferred hydrophilic binders are completely or partially saponified polyvinyl alcohol and cation-modified polyvinyl alcohol.

  The content of the resin binder in the porous layer is preferably in the range of 5 to 40% by mass with respect to the inorganic fine particles having an average secondary particle diameter of 500 nm or less, and particularly 10 to 30% by mass forms fine voids. It is preferable for forming a porous layer.

The dry coating amount of the porous layer is preferably in the range of 10 to 50 g / m ² , more preferably in the range of 12 to 40 g / m ² , especially 15 to 15 in terms of inorganic fine particles having an average secondary particle diameter of 500 nm or less. A range of 35 g / m ² is preferred. The porous layer further includes cationic polymers, preservatives, surfactants, colored dyes, colored pigments, UV absorbers, antioxidants, pigment dispersants, antifoaming agents, leveling agents, fluorescent whitening agents, viscosity Stabilizers, pH adjusters and the like can also be added.

  The porous layer may be composed of two or more layers. In this case, the structures of the porous layers may be the same or different from each other.

  In the present invention, various known coating methods can be used as the coating method used for coating the porous layer. Examples include a slide bead method, a slide curtain method, an extrusion method, a slot die method, a gravure roll method, an air knife method, a blade coating method, and a rod bar coating method.

  As the light-transmitting support of the present invention, the light-transmitting substrate described later may be used as it is, or a light-transmitting support in which an adhesive layer, a porous layer, etc. are provided on the light-transmitting substrate. It may be used as a body. For such an adhesive layer, generally used synthetic resin adhesives such as acrylic, silicone, urethane, and rubber can be used. The haze of the light transmissive support is preferably 30% or less.

  The light-transmitting substrate of the present invention is not particularly limited as long as it has a light-transmitting property, such as a plate-like one made of glass or plastic, a film-like one, and the porous layer described above. A layer having a light-transmitting layer can be used. The type of glass is not particularly limited, but in general, oxide glass such as silicate glass, phosphate glass, and borate glass is practical, especially silicate glass and alkali silicate glass. Silicate glass such as soda lime glass, potassium lime glass, lead glass, barium glass, and borosilicate glass is preferred. As the plastic, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polypropylene, polyethylene, polyarylate, acrylic, acetylcellulose, polyvinyl chloride, etc. can be used. This is preferable because the mechanical strength is improved. The haze of the light transmissive substrate is preferably 30% or less.

  The thickness of the light-transmitting substrate of the present invention can be appropriately selected according to the applied material, but is generally about 10 μm to 30 mm, preferably about 20 μm to 20 mm.

  In addition, when an adhesive layer is provided on the surface of the light-transmitting substrate on which the light diffusing fine particles are disposed, the opposite surface, and both surfaces, and the light-transmitting substrate is attached to another substrate having light transmittance, 10-200 micrometers is preferable and, as for the thickness of a base material, 20-130 micrometers is still more preferable. By setting the light transmission type support to such a thickness, it is possible to obtain a transmission type screen that is easy to be attached and is thin and light and convenient for carrying.

  In addition, the surface of the light transmissive substrate of the light transmissive support may be subjected to easy adhesion treatment for the purpose of improving the adhesion between the light diffusing fine particles and the light transmissive support. A layer may be provided.

  The see-through transmissive screen of the present invention may have a known antireflection layer having a performance of canceling reflected light by utilizing the interference action of light by the layer interface on at least one surface. Thereby, the image projected from the projector can be clearly seen. As the antireflection layer, for example, a single layer provided with a highly transparent low refractive index layer such as silicon oxide or lithium fluoride so as to be an optical thin film having a quarter wavelength of the main wavelength, or such A material in which a high refractive index layer such as titanium oxide or zinc oxide is appropriately laminated on a low refractive index layer can be used.

  Furthermore, the see-through transmissive screen of the present invention can be provided with a known hard coat layer, anti-diffusion layer or anti-static layer for increasing the strength of the screen on the outermost surface opposite to the light diffusing fine particle arrangement surface. It is.

  The see-through transmissive screen of the present invention can be used by projecting the image of the projector from either the light diffusing fine particle arrangement side or the opposite side. In general, in the case of a transmissive screen, when light is irradiated in parallel with the normal of the screen, a so-called hot spot, a direct light from a projector lens, is unavoidable to the viewer. It is preferable to use it with a certain degree of angle.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, the content of this invention is not restricted to an Example. In addition, a part represents the mass part of solid content or a substantial component.

Example 1
A porous layer coating solution 1 having the following composition was applied to one side of a transparent polyethylene terephthalate film (hazy value 4%) having a thickness of 100 μm using a slide bead coating device, and hot air of 35 ° C. and 50 ° C. was sequentially sprayed. It dried and obtained the transparent support body which has a porous layer. In addition, the haze of the produced light-transmitting support was 10%. The coating amount of the porous layer coating liquid 1 was 21 g / m ² in terms of silica solid content. After completion of drying, the void volume was measured using a mercury porosimeter (measuring instrument name: Autopore II 9220, manufacturer: micromeritics instrument corporation), which was 25 ml / m ² . Further, the light diffusing fine particle coating solution 1 having the following composition was coated by a pre-measuring type coating method using a slanted gravure roll, and dried by blowing hot air at 50 ° C. The oblique gravure roll used here is a gravure roll having a diameter of 60 mm, an oblique line angle of 45 degrees, a number of lines of 90 lines / inch, and a groove depth of 110 μm, and was used in reverse rotation. The moisture coating amount of the light diffusing fine particle coating solution 1 was set to 20 ml / m ² by adjusting the rotational speed of the oblique gravure roll. The amount of moisture applied was determined from the amount of coating solution decreased per unit time during application. When the light diffusing fine particle coating liquid 1 was applied on the porous layer, water as a solvent in the coating liquid was instantaneously absorbed in the voids of the porous layer, and a uniform coated surface was obtained. Then, the other adhesive layer was coated and dried with the following adhesive layer coating solution so that the solid content coating amount was 10 g / m ² to provide an adhesive layer, and this adhesive layer was bonded to a 5 mm thick float glass. The transmission screen of Example 1 was produced. The projected area of the light diffusing fine particles of this transmissive screen was 27%.

<Preparation of silica dispersion 1>
After adding 4 parts of dimethyldiallylammonium chloride homopolymer (molecular weight 9,000) and 100 parts of gas phase method silica (average primary particle diameter 7 nm, specific surface area 300 m ² / g) to water to prepare a preliminary dispersion, a high-pressure homogenizer To prepare a silica dispersion having a solid concentration of 20%. The average secondary particle diameter was 130 nm when measured using LA910 manufactured by HORIBA, Ltd.

<Porous layer coating solution 1>
Silica dispersion 1 (as silica solid content) 100 parts polyvinyl alcohol 23 parts (saponification degree 88%, average polymerization degree 3500)
Boric acid 4 parts Nonionic surfactant 0.3 parts (Polyoxyethylene alkyl ether)
The whole solid content concentration was adjusted with water so as to be 12.85%.

<Light diffusion fine particle layer coating solution 1>
Gelatin 200 parts Light diffusing fine particles 100 parts (SSX-101: manufactured by Sekisui Plastics Co., Ltd., crosslinked polymethyl methacrylate, average particle size 1.6 μm, refractive index 1.49)
Nonionic surfactant 0.6 parts (polyoxyethylene alkyl ether)
It was adjusted with water so that the gelatin solid content concentration was 5.0%.

<Adhesive layer coating solution>
Acrylic adhesive 100 parts Isocyanate curing agent It was adjusted with ethyl acetate so that the solid content concentration of the whole 2.5 parts was 50%.

(Example 2)
A transmissive screen of Example 2 was produced in the same manner as in Example 1 except that the amount of light diffusing fine particles added in Example 1 was changed to 80 parts. The projected area of the light diffusing fine particles of the transmissive screen was 22%.

(Example 3)
A transmissive screen of Example 3 was produced in the same manner as in Example 1 except that the addition amount of the light diffusing fine particles of Example 1 was changed to 60 parts. The projected area of the light diffusing fine particles of this transmissive screen was 17%.

Example 4
A transmissive screen of Example 4 was produced in the same manner as in Example 1 except that the addition amount of the light diffusing fine particles of Example 1 was 40 parts. The projected area of the light diffusing fine particles of the transmission screen was 10%.

(Example 5)
A porous layer coating solution 2 having the following composition was applied to one side of the transparent polyethylene terephthalate film used in Example 1 by using a slide bead coating device, and dried by sequentially blowing hot air at 35 ° C. and 50 ° C. A light-transmitting support having a quality layer was obtained. In addition, the haze of the produced light-transmitting support was 18%. The coating amount of the porous layer coating liquid 2 was 20 g / m ² in terms of silica solid content. After completion of drying, the void volume was measured using a mercury porosimeter (measuring instrument name: Autopore II 9220, manufacturer: micromeritics instrument corporation), which was 25 ml / m ² . Subsequent steps were carried out in the same manner as in Example 4 to produce a transmission screen of Example 5. The projected area of the light diffusing fine particles of the transmission screen was 10%.

<Preparation of silica dispersion 2>
After adding 4 parts of dimethyldiallylammonium chloride homopolymer (molecular weight 9,000) and 100 parts of vapor phase method silica (average primary particle diameter 7 nm, specific surface area 300 m ² / g) to water to prepare a preliminary dispersion, silica dispersion The conditions at the time of preparing the liquid 1 were changed and the mixture was treated with a high-pressure homogenizer to produce a silica dispersion having a solid concentration of 20%. The average secondary particle diameter was 250 nm when measured using LA910 manufactured by HORIBA, Ltd.

<Porous layer coating solution 2>
Silica dispersion 2 (as silica solid content) 100 parts polyvinyl alcohol 23 parts (saponification degree 88%, average polymerization degree 3500)
Boric acid 4 parts Nonionic surfactant 0.3 parts (Polyoxyethylene alkyl ether)
The whole solid content concentration was adjusted with water so as to be 12.85%.

(Example 6)
The porous layer coating solution 1 is applied to one side of the transparent polyethylene terephthalate film used in Example 1 using a slide bead coating device, and dried by sequentially blowing hot air at 35 ° C. and 50 ° C. A light transmissive support was obtained. Note that the haze of the manufactured light-transmitting support was 6%. The coating amount of the porous layer coating liquid 1 was 6 g / m ² in terms of silica solid content. After completion of drying, the void volume was measured using a mercury porosimeter (measuring instrument name: Autopore II 9220, manufacturer: micromeritics instrument corporation), which was 8 ml / m ² . Further, the same light diffusing fine particle coating solution as in Example 1 was applied by a pre-weighing type application method using a slanted gravure roll so that the moisture application amount was 7 ml / m ² , and hot air at 50 ° C. was sprayed. Dried. When the light diffusing fine particle coating solution was applied on the porous layer, water as a solvent in the coating solution was instantaneously absorbed into the voids of the porous layer, and a uniform coated surface was obtained. Subsequent steps were performed in the same manner as in Example 1, and a transmission screen of Example 6 was produced. The projected area of the light diffusing fine particles of this transmission screen was 9%.

(Example 7)
A transmissive screen of Example 7 was produced in the same manner as in Example 1 except that the light diffusing fine particle coating solution 1 of Example 1 was changed to the following light diffusing fine particle coating solution 2. The projected area of the light diffusing fine particles of the transmission screen was 10%.

<Light diffusion fine particle layer coating solution 2>
Gelatin 200 parts Light diffusing fine particles 200 parts (SSX-104: manufactured by Sekisui Plastics Co., Ltd., cross-linked polymethyl methacrylate, average particle diameter 4.0 μm, refractive index 1.49)
Nonionic surfactant 0.6 parts (polyoxyethylene alkyl ether)
It was adjusted with water so that the gelatin solid content concentration was 5.0%.

(Example 8)
A transmissive screen of Example 8 was produced in the same manner as in Example 1 except that the light diffusing fine particle coating liquid 1 of Example 1 was changed to the following light diffusing fine particle coating liquid 3. The projected area of the light diffusing fine particles of the transmissive screen was 77%.

<Light diffusion fine particle layer coating solution 3>
Gelatin 200 parts Light diffusing fine particles 500 parts (acrylic resin fine particles, average particle size 0.1 μm, refractive index 1.49)
Nonionic surfactant 0.6 parts (polyoxyethylene alkyl ether)
It was adjusted with water so that the gelatin solid content concentration was 5.0%.

Example 9
A transmissive screen of Example 9 was produced in the same manner as in Example 1 except that the light diffusing fine particle coating liquid 1 of Example 1 was changed to the following light diffusing fine particle coating liquid 4. The projected area of the light diffusing fine particles of the transmissive screen was 60%.

<Light diffusion fine particle layer coating solution 4>
Gelatin 200 parts Light diffusing fine particles 300 parts (Grossdale 204S: made by Mitsui Chemicals, acrylic resin fine particles, average particle size 0.2 μm, refractive index 1.49)
Nonionic surfactant 0.6 parts (polyoxyethylene alkyl ether)
It was adjusted with water so that the gelatin solid content concentration was 5.0%.

(Example 10)
A transmissive screen of Example 10 was produced in the same manner as in Example 1 except that the light diffusing fine particle coating liquid 1 of Example 1 was changed to the following light diffusing fine particle coating liquid 5. The projected area of the light diffusing fine particles of the transmissive screen was 15%.

<Light diffusion fine particle layer coating solution 5>
Gelatin 200 parts Light diffusing fine particles 40 parts (Grossdale 207S: manufactured by Mitsui Chemicals, acrylic resin fine particles, average particle diameter 0.6 μm, refractive index 1.49)
Nonionic surfactant 0.6 parts (polyoxyethylene alkyl ether)
It was adjusted with water so that the gelatin solid content concentration was 5.0%.

(Example 11)
A transmissive screen of Example 11 was produced in the same manner as in Example 1 except that the light diffusing fine particle coating liquid 1 of Example 1 was changed to the following light diffusing fine particle coating liquid 6. The projected area of the light diffusing fine particles of the transmissive screen was 6%.

<Light diffusion fine particle layer coating solution 6>
Gelatin 200 parts Light diffusing fine particles 30 parts (Grossdale 110M: manufactured by Mitsui Chemicals, acrylic resin fine particles, average particle size 1.0 μm, refractive index 1.49)
Nonionic surfactant 0.6 parts (polyoxyethylene alkyl ether)
It was adjusted with water so that the gelatin solid content concentration was 5.0%.

(Example 12)
A transmissive screen of Example 12 was produced in the same manner as in Example 1 except that the light diffusing fine particle coating liquid 1 of Example 1 was changed to the following light diffusing fine particle coating liquid 7. The projected area of the light diffusing fine particles of the transmission screen was 12%.

<Light diffusion fine particle layer coating solution 7>
Gelatin 200 parts Light diffusing fine particles 35 parts (Opto beads 500S: manufactured by Nissan Chemical Industries, silica, melamine resin composite fine particles (mainly melamine resin), average particle size 0.5 μm, refractive index 1.65)
Nonionic surfactant 0.6 parts (polyoxyethylene alkyl ether)
It was adjusted with water so that the gelatin solid content concentration was 5.0%.

(Example 13)
A transmissive screen of Example 13 was produced in the same manner as in Example 1 except that the light diffusing fine particle coating liquid 1 of Example 1 was changed to the following light diffusing fine particle coating liquid 8. The projected area of the light diffusing fine particles of the transmissive screen was 9%.

<Light diffusion fine particle layer coating solution 8>
Gelatin 200 parts Light diffusing fine particles 45 parts (Opto beads 2000M: manufactured by Nissan Chemical Industries, Ltd., silica, melamine resin composite fine particles (mainly melamine resin), average particle size 2.0 μm, refractive index 1.65)
Nonionic surfactant 0.6 parts (polyoxyethylene alkyl ether)
It was adjusted with water so that the gelatin solid content concentration was 5.0%.

(Example 14)
A transmissive screen of Example 14 was produced in the same manner as in Example 1 except that the light diffusing fine particle coating solution 1 of Example 1 was changed to the following light diffusing fine particle coating solution 9. The projected area of the light diffusing fine particles of the transmissive screen was 7%.

<Light diffusion fine particle layer coating solution 9>
Gelatin 200 parts Light diffusing fine particles 200 parts (Opto beads 3500M: manufactured by Nissan Chemical Industries, Ltd., silica, melamine resin composite fine particles (mainly melamine resin), average particle size 3.5 μm, refractive index 1.65)
Nonionic surfactant 0.6 parts (polyoxyethylene alkyl ether)
It was adjusted with water so that the gelatin solid content concentration was 5.0%.

(Comparative Example 1)
A porous layer is not coated on one side of the transparent polyethylene terephthalate film used in Example 1, and the light-diffusing fine particle coating solution used in Example 1 is directly applied to a moisture application amount of 20 g / m ^2. A transmissive screen of Comparative Example 1 was produced in the same manner as in Example 1 except that coating was performed using a bar coater coating apparatus and drying was performed by blowing hot air at 50 ° C.

(Comparative Example 2)
A porous layer is not coated on one side of the transparent polyethylene terephthalate film used in Example 1, and the light-diffusing fine particle coating solution used in Example 2 is directly applied to a moisture application amount of 20 g / m ^2. A transmissive screen of Comparative Example 2 was produced in the same manner as in Example 2 except that coating was performed using a bar coater coating apparatus and drying was performed by blowing hot air at 50 ° C.

(Comparative Example 3)
A porous layer is not coated on one side of the transparent polyethylene terephthalate film used in Example 1, and the light-diffusing fine particle coating solution used in Example 3 is directly applied to a moisture application amount of 20 g / m ^2. A transmissive screen of Comparative Example 3 was produced in the same manner as in Example 3 except that coating was performed using a bar coater coating apparatus and drying was performed by blowing hot air at 50 ° C.

(Comparative Example 4)
A porous layer is not coated on one side of the transparent polyethylene terephthalate film used in Example 1, and the light-diffusing fine particle coating solution used in Example 4 is directly applied to a moisture application amount of 20 g / m ^2. A transmissive screen of Comparative Example 4 was produced in the same manner as in Example 4 except that coating was performed using a bar coater coating apparatus and drying was performed by blowing hot air at 50 ° C.

(Comparative Example 5)
Apply the slide bead on one side of the transparent polyethylene terephthalate film used in Example 1 so that the porous layer coating liquid 1 and the light diffusing fine particle coating liquid of Example 4 have the same moisture application amount as in Example 1. A transmissive screen of Comparative Example 5 was produced in the same manner as in Example 4 except that simultaneous multilayer coating was performed using an apparatus, and hot air of 35 ° C. and 50 ° C. was sequentially blown and dried.

(Comparative Example 6)
A single layer of porous layer coating solution 3 having the following composition was applied to one side of the transparent polyethylene terephthalate film used in Example 1 using a slide bead coating device, and hot air of 35 ° C. and 50 ° C. was sequentially blown and dried. A light-transmitting support having a porous layer was obtained. The produced support had a haze of 52%. The coating amount of the porous layer coating liquid 3 was 20 g / m ² in terms of silica solid content. After completion of drying, the void volume was measured using a mercury porosimeter (measuring instrument name: Autopore II 9220, manufacturer: micromeritics instrument corporation), which was 25 ml / m ² . Subsequent steps were performed in the same manner as in Example 4, and a transmission screen of Comparative Example 6 was produced. The projected area of the light diffusing fine particles of the transmission screen was 10%.

<Preparation of silica dispersion 3>
After adding 4 parts of dimethyldiallylammonium chloride homopolymer (molecular weight 9,000) and 100 parts of vapor phase method silica (average primary particle diameter 7 nm, specific surface area 300 m ² / g) to water to prepare a preliminary dispersion, silica dispersion The conditions at the time of preparing the liquid 1 were changed and the mixture was treated with a high-pressure homogenizer to produce a silica dispersion having a solid concentration of 20%. The average secondary particle size was 750 nm as measured using LA910 manufactured by Horiba.

<Porous layer coating solution 3>
Silica dispersion 3 (as silica solid content) 100 parts polyvinyl alcohol 23 parts (saponification degree 88%, average polymerization degree 3500)
Boric acid 4 parts Nonionic surfactant 0.3 parts (Polyoxyethylene alkyl ether)
The whole solid content concentration was adjusted with water so as to be 12.85%.

(Comparative Example 7)
Before using a slanted gravure roll on the porous layer of the light-transmitting support used in Example 6, the same light diffusing fine particle coating liquid as in Example 1 so that the moisture coating amount becomes 20 ml / m ^2. It apply | coated by the measurement type application | coating system, and it dried by blowing 50 degreeC hot air. At this time, the solvent in the light diffusing fine particle coating solution overflowed on the porous layer, and a good surface that could be used for subsequent evaluation was not obtained due to the bubbles generated from the porous layer.

(Comparative Example 8)
A transmissive screen of Comparative Example 8 was produced in the same manner as in Example 1 except that only the porous layer of Example 1 was coated and the light diffusing fine particle coating solution was not coated.

(Comparative Example 9)
The coating method of the light diffusing fine particle coating solution of Example 1 was applied by a fountain-air knife method which is not a pre-weighing type coating method. The conditions were adjusted to achieve the same moisture application amount of 20 g / m ² as in Example 1, but the solvent was instantaneously absorbed into the porous layer, and the target application amount could not be obtained. Further, bubbles generated from the porous layer As a result, a good surface that could be used for subsequent evaluation was not obtained.

(Comparative Example 10)
Before using a slanted gravure roll on the porous layer of the light-transmitting support used in Example 6, the same light diffusing fine particle coating liquid as in Example 1 so that the moisture coating amount becomes 10 ml / m ^2. It apply | coated by the measurement type application | coating system, and it dried by blowing 50 degreeC hot air. At this time, the solvent in the light diffusing fine particle coating solution overflowed on the porous layer, and a good surface that could be used for subsequent evaluation was not obtained due to the bubbles generated from the porous layer.

  Regarding the obtained transmission screens of Examples 1 to 14 and Comparative Examples 1 to 6 and 8, the transparency and the visibility of the image at the time of projector projection were evaluated according to the following criteria. These results are shown in Table 1.

<Transparency>
The transparency was evaluated by measuring haze using a HazeComputer HZ-2 manufactured by Suga Test Instruments.

<Visibility of images during projection by projector>
The visibility of the image when the projector is projected is based on the following evaluation criteria: the image is actually projected on the transmission screen by a digital projector (MP515ST, manufactured by BenQ), and the image projected on the screen from the opposite side of the projector Was evaluated visually. The projector irradiated with an angle of about 30 degrees with respect to the normal of the screen, and the evaluator visually evaluated the image at a position parallel to the screen.
◎◎: The brightness of the video is clearly higher than the following ◎ level and the visibility is very good ◎: The brightness of the video is extremely high and the visibility is very good ○: The brightness of the video is high and the visibility is good x: The brightness of the video Is low and visibility is low

  Regarding the obtained transmission screens of Examples 1 to 14 and Comparative Examples 1 to 6, when the light diffusing fine particles were observed with an electron microscope, the light diffusing fine particles were two-dimensionally arranged in Examples 1 to 14 and Comparative Example 6. However, in Comparative Examples 1 to 5, a part of the light diffusing fine particles overlapped to form a three-dimensional arrangement layer.

  From the results shown in Table 1, it can be seen that the see-through transmissive screen of the present invention and the manufacturing method thereof can provide a see-through transmissive screen satisfying both high see-through property and image visibility during projection by the projector. .

DESCRIPTION OF SYMBOLS 1 Transparent type | mold transparent screen 2 Light-diffusion fine particle 3 Porous layer 4 Light-transmissive support body 5 Light-transmissive base material 6 Adhesive layer 7 Conventional light-diffusion layer

Claims (5)

  A see-through transmissive screen in which light diffusing fine particles are two-dimensionally arranged on at least one surface of a light transmissive support.   The light transmissive support is a support having a porous layer containing inorganic fine particles having an average secondary particle diameter of 500 nm or less and a resin binder on at least one surface of a light transmissive substrate. The see-through transmissive screen as described.   3. The see-through transmissive screen according to claim 1, wherein the light diffusing fine particles have an average particle diameter of 0.15 to 2.75 [mu] m.   4. The see-through transmissive screen according to claim 1, wherein the light diffusing fine particles have an average particle size of 0.35 to 0.80 [mu] m.   A porous layer coating solution containing inorganic fine particles having an average secondary particle diameter of 500 nm or less and a resin binder is applied to at least one surface of the light-transmitting substrate, and after drying at a reduced rate in the drying process or after drying A method for producing a see-through transmissive screen, characterized in that after completion, a coating liquid containing light diffusing fine particles is applied by a pre-measuring type coating method with a void volume of the porous layer or less and dried.

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