WO2021131393A1

WO2021131393A1 - Screen film and projection system provided with same

Info

Publication number: WO2021131393A1
Application number: PCT/JP2020/042568
Authority: WO
Inventors: 水谷拓雄; 吉田健一郎
Original assignee: マクセルホールディングス株式会社
Priority date: 2019-12-27
Filing date: 2020-11-16
Publication date: 2021-07-01
Also published as: JPWO2021131393A1

Abstract

A screen film 10 disclosed in the present application is provided with a transparent base material 11, a protective layer 12, a light diffusion layer 13 and a light diffusion adhesive layer 14; the protective layer 12 is arranged on one main surface side of the transparent base material 11; the light diffusion layer 13 and the light diffusion adhesive layer 14 are sequentially arranged in this order from the other main surface side of the transparent base material 11; the light diffusion layer 13 contains a first light-diffusing filler and a resin; the light diffusion adhesive layer 14 contains a second light-diffusing filler and an adhesive; and the difference between the refractive index of the first light-diffusing filler and the refractive index of the second light-diffusing filler is 0.50 or more.

Description

Screen film and projection system with it

The present application relates to a screen film having excellent optical characteristics, projectivity and scratch resistance, and a projection system equipped with the screen film.

In recent years, in commercial facilities that are entirely covered with glass, and in show windows of stores such as convenience stores, department stores, clothing, and automobiles, as advertisements, information, and information media, instead of conventional signs, posters, and large screen displays, windows are used. By pasting a transparent screen on the show window, the window itself can be made into a large screen, and advertisements and product information can be displayed from the indoor side using a projector while maintaining transparent visibility at a level where the indoor condition and products can be seen from the outside. The so-called digital signage, which projects and displays various other content images, has a very high eye-catching effect on people outside the room, and it is easy to respond to changes in the content, and it is convenient. (For example, Patent Documents 1 to 4).

Patent Document 1 describes a transmissive screen having a light diffusing layer containing a light diffusing element in a transparent binder, wherein the light diffusing element has a relative refractive index n with respect to the refractive index of the transparent binder. Transmissive screens have been proposed that use hollow beads of 0.75 or less and have an overall haze of 10-85%. In the transmissive screen of Patent Document 1, the refractive index of the light diffusing layer is lowered by using hollow beads which are spherical fine particles. However, if the relative refractive index is 0.75 or less, the light diffusing layer can be combined with the binder. It is considered that the difference in refractive index is not sufficient, and it is difficult to obtain sufficient projectivity only by using fine particles having a low refractive index.

Patent Document 2 includes a resin layer and inorganic particles contained in the resin layer, and the primary particles of the inorganic particles have a median diameter of 0.1 to 50 nm and a median diameter of 10 to 500 nm. A transparent screen film having a maximum particle size, the content of the inorganic particles being 0.015 to 1.2% by mass with respect to the resin, and the inorganic particles being metal-based particles has been proposed. There is. The transparent screen film of Patent Document 2 uses a film provided with a resin layer containing inorganic particles, but it is considered that sufficient projectability cannot be obtained only with the resin layer containing inorganic particles. Further, it is considered that the above-mentioned particles having a median diameter and the maximum particle size have a particle size distribution smaller than that in the visible light region in the coating film, so that a sufficient light scattering effect cannot be obtained and it is difficult to obtain projectability.

Patent Document 3 describes a resin medium, first particles having a median diameter of 50 nm or more and 360 nm or less dispersed in the resin medium, and median diameters dispersed in the resin medium of 500 nm or more. A light scatterer having a size of 5 μm or less and containing a second particle having a diamond structure, wherein the total content of the first particle and the second particle is 100 parts by mass of the resin medium. or less 20.0 parts by mass or more 0.01 part by mass, the particle number ratio M ₁ / M ₂ of the number of particles M ₁ and the second particle number M ₂ of the first particles in the 100 to 5000 A projection screen including a light scatterer having a total light transmittance of 80% or more has been proposed. The projection screen of Patent Document 3 uses a light scatterer containing particles having a diamond structure, but it is considered that sufficient projectability cannot be obtained by itself.

Patent Document 4 proposes a transparent heat shield member having a transparent screen function provided with a light diffusing adhesive layer using an adhesive in a transparent resin that disperses light diffusing particles. In the transparent heat shield member provided with the transparent screen function of Patent Document 4, the light diffusing filler is dispersed only in the light diffusing adhesive layer, and the difference in refractive index between the light diffusing filler and the adhesive is small, which is sufficient. It is considered that it is difficult to obtain a good projectivity.

Japanese Patent No. 4847329 Japanese Patent No. 5725834 Japanese Unexamined Patent Publication No. 2019-13657 Japanese Unexamined Patent Publication No. 2016-186627

The present application solves the above-mentioned problems of the conventional screen film, and provides a screen film having excellent optical characteristics, projectivity and scratch resistance, and a projection system including the screen film.

The screen film disclosed in the present application is a screen film including a transparent base material, a protective layer, a light diffusing layer, and a light diffusing adhesive layer, and the protective layer is one main surface side of the transparent base material. The light diffusing layer and the light diffusing adhesive layer are arranged in this order from the other main surface side of the transparent base material, and the light diffusing layer is composed of a first light diffusing filler and a resin. The light-diffusing adhesive layer contains a second light-diffusing filler and a pressure-sensitive adhesive, and has the refractive index of the first light-diffusing filler and the refractive index of the second light-diffusing filler. The difference between the two is 0.50 or more.

Further, the projection system disclosed in the present application is a projection system including the screen film disclosed in the present application and a projector.

The present application can provide a screen film having excellent optical characteristics, projectivity and scratch resistance, and a projection system including the screen film.

FIG. 1 is a schematic cross-sectional view showing an example of the screen film disclosed in the present application. FIG. 2 is a schematic view illustrating a method for evaluating the projectivity of a screen film disclosed in the present application.

(Screen film)
An embodiment of the screen film disclosed in the present application will be described. The screen film of the present embodiment includes a transparent base material, a protective layer, a light diffusing layer, and a light diffusing adhesive layer, and the protective layer is arranged on one main surface side of the transparent base material. The light diffusing layer and the light diffusing adhesive layer are arranged in this order from the other main surface side of the transparent base material, and the light diffusing layer contains a first light diffusing filler and a resin, and the light The diffusive adhesive layer contains a second light diffusing filler and a pressure-sensitive adhesive, and the difference between the refractive index of the first light diffusing filler and the refractive index of the second light diffusing filler is 0. .50 or more.

In the screen film of the present embodiment, since the light diffusing layer is arranged between the transparent base material and the light diffusing adhesive layer, the scratch resistance of the screen film can be improved. That is, after the screen film is applied, the film surface is easily damaged by contact during cleaning, scratches caused by nails, rain, chemicals such as cleaners, and other external factors. On the other hand, the protective layer can protect the surface to some extent, but the protective layer gradually deteriorates after many years of use. Therefore, if the light diffusing layer is located closer to the protective layer than the transparent base material, the light diffusing layer is also easily damaged due to deterioration of the protective layer due to long-term use, and if there is a deteriorated part in the light diffusing layer at the time of projection. A beautiful image cannot be projected. On the other hand, by arranging the light diffusing layer between the transparent base material and the light diffusing adhesive layer, the scratch resistance of the screen film can be improved and the projectivity can be maintained.

Further, by incorporating the light diffusing filler in both the light diffusing layer and the light diffusing adhesive layer, sufficient image brightness is obtained at the time of projection as compared with the case where the light diffusing filler is contained only in the light diffusing layer. Obtainable. That is, by incorporating the light diffusing filler in the light diffusing adhesive layer, the light diffused in the light diffusing adhesive layer can be efficiently further diffused in the light diffusing adhesive layer by utilizing the thickness of the light diffusing adhesive layer, and the light can be further diffused. Light transmitted without diffusing the diffusing layer can also be diffused by the light diffusing adhesive layer, and the brightness of the image can be improved.

Further, by setting the difference between the refractive index of the first light diffusing filler and the refractive index of the second light diffusing filler to 0.50 or more, a clearer image can be provided. That is, when the screen film of the present embodiment is used as a transmissive screen film, the light incident from the projector is transmitted to the human eye in the order of the protective layer, the transparent base material, the light diffusing layer, and the light diffusing adhesive layer. Is recognized as. Here, since the refractive index of the light diffusing layer is high, the light entering from the projector can be efficiently diffused by the filler in the light diffusing layer to provide a high-brightness image, but the diffused light is further diffused by the filler in the light diffusing adhesive layer. Is further diffused by. At this time, the larger the difference in refractive index between the filler of the light diffusing layer and the filler of the light diffusing adhesive layer, the clearer the image can be provided.

In the screen film of the present embodiment, the total light transmittance is preferably 60 to 90%, and the haze value is preferably 5.0 to 30.0%. The JIS standard for architectural window films (JIS K5759) stipulates that the total light transmittance is 60% or more as the definition of a transparent film. That is, if the total light transmittance is 60% or more, it can be said that the film is a transparent film in which information through the film can be recognized even when the film is not projected by the projector. Regarding the haze value, the lower the haze value, the less fogging, the easier it is to obtain information through the film during non-projection, and it can be said that the transparency is high. Diffusion may not be obtained and the projectivity may be insufficient. On the other hand, when the haze value is 30% or more, the projectivity is easily obtained, but the transparency at the time of non-projection becomes insufficient and the transparency may be lacking.

The protective layer preferably contains an ionizing radiation curable resin or a thermosetting resin. This is because these resins have high hardness and excellent scratch resistance.

The refractive index of the first light diffusing filler is preferably 1.85 or more and less than 2.75. The higher the refractive index of the filler used in the light diffusion layer, the more efficiently the light received during projection by the projector is reflected by the filler, and the image can be recognized clearly and at a high viewing angle.

The average particle size of the first light diffusing filler is preferably 0.05 to 1.5 μm. In order to efficiently scatter the light forward in the light diffusion layer with respect to the light projected by the projector, it is good to apply a phenomenon called "Mie scattering", in which the particle size of the particles is slightly higher than the visible light region. Light can be most efficiently scattered forward by existing in a region, that is, a region of about 0.3 to 1.2 μm. Therefore, when the average particle size of the filler is less than 0.05 μm, the filler is too fine and the light in the visible light region passes through the light diffusing layer, so that the light cannot be diffused efficiently and the projectivity is insufficient. Become. On the other hand, when the average particle size of the filler exceeds 1.5 μm, geometric scattering and absorption of light into the particles occur, the scattering of light in the forward direction becomes weak, and the internal haze rises due to the large particles, and the film becomes transparent. The sex drops.

Here, the average particle size means an average primary particle size or an average dispersed particle size. This is because when the filler particles are fine, the primary particles may aggregate and exist as aggregated particles. Usually, when comparing the same particles, the average dispersed particle size is larger than the average primary particle size.

The first light diffusing filler is preferably at least one selected from the group consisting of diamond, titanium oxide and zirconium oxide. These have a high refractive index, can efficiently diffuse light, have high brightness when projected, and can obtain an image having a wide viewing angle.

The content of the first light diffusing filler is preferably 0.5 to 5.0% by mass with respect to the total solid content of the light diffusing layer. If the content is less than 0.5% by mass, the transmitted light cannot be sufficiently diffused and the image is difficult to be clear, and if it exceeds 5.0% by mass, the transparency of the light diffusion layer is lowered.

The film thickness of the light diffusion layer is preferably 0.5 to 10.0 μm. If the film thickness is less than 0.5 μm, light cannot be sufficiently diffused, and if it exceeds 10 μm, the total light transmittance of the film tends to decrease, the haze value tends to increase, and the transparency at the time of non-projection decreases.

The refractive index of the second light diffusing filler is preferably 1.20 or more and less than 1.50. The larger the difference between the refractive index of the second light diffusing filler contained in the light diffusing adhesive layer and the refractive index of the first light diffusing filler contained in the light diffusing layer, the clearer the image can be recognized. Therefore, the refractive index of the second light diffusing filler is set lower than the refractive index of the first light diffusing filler. Further, as a result, the difference between the refractive index of the pressure-sensitive adhesive contained in the light-diffusing adhesive layer and the refractive index of the second light-diffusing filler becomes large, light can be efficiently diffused, and the light-diffusing layer can be diffused. The visible light diffused in the above can be made clearer, and the transmitted light can be diffused by the light diffusing adhesive layer without diffusing the light diffusing layer.

The second light diffusing filler is spherical, and its average particle size is preferably 0.1 to 1.5 μm. In this case as well, it is preferable to apply the phenomenon of "Mie scattering" as in the case of the first light diffusing filler. When the light diffusing filler is spherical, the light of the projector that travels straight and is incident is more efficiently scattered forward, and the visibility of the image from the front of the screen is improved. Further, when the average particle size is less than 0.1 μm, the particle size is smaller than that in the visible light region, so that visible light is transmitted and the light cannot be diffused efficiently, resulting in insufficient projectability. Further, when the average particle diameter exceeds 1.5 μm, geometric scattering and absorption of light into particles occur as in the light diffusion layer, the scattering of light in the forward direction becomes weak, and the internal haze rises due to the large particles. As a result, the transparency of the film decreases. As described above, the average particle size means the average primary particle size or the average dispersed particle size.

The content of the second light diffusing filler is preferably 0.2 to 5.0% by mass with respect to the total solid content of the light diffusing adhesive layer. If the content is less than 0.2% by mass, the transmitted light cannot be sufficiently diffused and the image is difficult to be clear, and if it exceeds 5% by mass, the transparency of the coating film is lowered and the adhesive strength is lowered. There is a concern that it will cause it to come off easily after it is applied to the window.

The light diffusing adhesive layer preferably contains an acrylic adhesive. When the screen film of the present embodiment is applied to the window glass, it is applied by a method generally called "watering". This is done by sufficiently moistening the window glass with water containing a surfactant, attaching a film, and removing the water that has entered the interface between the window glass and the film with a squeegee, etc., and at the same time removing air, dust, etc. at the interface. It is a method of pulling out and fixing together. Acrylic adhesives can easily control functional groups, and can easily form an adhesive layer with excellent water drainage during water application and adhesion to glass after construction. By dispersing the light diffusing filler in this acrylic pressure-sensitive adhesive, in addition to the light diffusing property of the single film of the light diffusing layer, the thickness of the light diffusing adhesive layer is used to efficiently diffuse light and increase the brightness. A high projected image can be provided.

The film thickness of the light diffusion adhesive layer is preferably 10 to 50 μm. If the film thickness is less than 10 μm, the adhesive strength is not sufficient and there is a risk of peeling after construction, and the light diffusing adhesive layer is thin, so that the light diffusing property is also poor. When the film thickness exceeds 50 μm, the adhesive force is saturated, the transmittance is lowered due to the thickness of the light diffusing adhesive layer, and the transparency at the time of non-projection is impaired.

The screen film of the present embodiment not only has a transmission screen function that allows the image projected from the projector to be visually recognized as a transmission image from the opposite side of the projector, but also reflects the projected image from the projector side. It also has a reflective screen function that can be visually recognized as.

Hereinafter, each component of the screen film of the present embodiment will be described.

<Transparent base material>
The transparent base material is not particularly limited as long as it is made of a translucent material. Examples of the transparent base material include polyester resins (for example, polyethylene terephthalate, polyethylene naphthalate, etc.), polycarbonate resins, polyacrylic acid ester resins (for example, polymethyl methacrylate, etc.), alicyclic polyolefin resins, and the like. Polystyrene resin (for example, polystyrene, acrylonitrile / styrene copolymer, etc.), polyvinyl chloride resin, polyvinyl acetate resin, polyether sulfone resin, cellulose resin (for example, diacetyl cellulose, triacetyl cellulose, etc.), A resin such as a norbornene-based resin processed into a film or a sheet can be used. Examples of the method for processing the resin into a film or sheet include an extrusion molding method, a calender molding method, a compression molding method, an injection molding method, and a method in which the resin is dissolved in a solvent and cast. Additives such as antioxidants, flame retardants, heat stabilizers, ultraviolet absorbers, glidants, and antistatic agents may be added to the resin. The thickness of the transparent base material is, for example, 10 μm or more and 500 μm or less, and is preferably 25 μm or more and 125 μm or less in consideration of workability and cost.

<Protective layer>
The protective layer is arranged on one main surface side of the transparent base material, but is usually formed directly on the main surface of the transparent base material. The protective layer can be made of an ionizing radiation curable resin or a thermosetting resin. Thereby, the scratch resistance of the protective layer can be improved.

The thickness of the protective layer is preferably 2 μm to 5 μm, more preferably 3 μm to 4 μm. When the thickness of the protective layer is within this range, sufficient scratch resistance can be obtained.

[Ionizing radiation curable resin]
The protective layer made of the ionizing radiation curable resin is formed by irradiating an ionizing radiation curable resin oligomer or an ionizing radiation curable resin monomer with ionizing radiation and curing the layer.

The weight average molecular weight of the ionizing radiation curable resin oligomer is preferably 10,000 to 100,000. When the weight average molecular weight is within the above range, the coatability of the protective layer forming coating liquid used for forming the protective layer can be improved, and the scratch resistance of the formed protective layer can be improved. In the present application, the weight average molecular weight of the oligomer is measured by a GPC (gel permeation chromatography) method.

That is, if the weight average molecular weight is less than 10,000, cissing may occur when the protective layer forming coating liquid is applied to a transparent substrate. Further, when the weight average molecular weight is larger than 100,000, the number of unsaturated bond groups which are reaction points per molecular weight when cured by ionizing radiation generally decreases, so that the crosslink density of the coating film decreases and protection is achieved. There is a tendency that the scratch resistance as a layer cannot be sufficiently exhibited.

As the ionizing radiation curable resin oligomer having a weight average molecular weight of 10,000 to 100,000, for example, a polyfunctional acrylate oligomer such as urethane-based, epoxy-based, or polyester-based can be used. Of these, urethane-based polyfunctional acrylate oligomers are preferable because they can easily balance the hardness and flexibility of the protective layer to be formed. The urethane-based polyfunctional acrylate oligomer can be obtained, for example, by reacting a urethane acrylate having a polymer of acrylate in the main chain skeleton and having a reactive acryloyl group at the end.

As for the above polyfunctional acrylate oligomer, a commercially available product can also be used. For example, "BPZA-66" and "BPZA-100" (trade name) manufactured by Kyoeisha Chemical Co., Ltd., "Acryt 8KX-012C" and "8KX-077" (trade name) manufactured by Taisei Fine Chemical Co., Ltd., and Hitachi Kasei Kogyo Co., Ltd. "Hitaroid 7975", "Hitaroid 7975D", "Hitaroid 7988" (trade name), "ACA-200M", "ACA-230AA", "ACA-Z250", "ACA-Z251", manufactured by Daisel Ornex. "ACA-Z300", "ACA-Z320" (trade name) and the like can be used.

An ionizing radiation-curable resin monomer can be used instead of the ionizing radiation-curable resin oligomer as long as the film-forming property of the protective layer-forming coating liquid on the transparent substrate is not deteriorated. A polyfunctional acrylate monomer having two or more saturated groups can be used. Specifically, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth). ) Acrylate, Trimethylol Propanetri (meth) Acrylate, Trimethylol Ethantri (Meta) Acrylate, Dipentaerythritol Tetra (Meta) Acrylate, Dipentaerythritol Penta (Meta) Acrylate, Dipentaerythritol Hexa (Meta) Acrylate, 1, Acrylate such as 2,3-cyclohexanetrimethacrylate; Polyurethane polyacrylate such as pentaerythritol triacrylate hexamethylenediisocyanate urethane prepolymer; Esters produced from polyhydric alcohol such as polyester polyacrylate and (meth) acrylic acid; 1 , 4-Divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, vinylbenzene such as 1,4-divinylcyclohexanone and derivatives thereof.

Further, the ionizing radiation curable resin monomer can be used by mixing with the ionizing radiation curable resin oligomer.

[Thermosetting resin]
As the heat-curable resin, for example, silicone resin, phenol resin, urea resin, diallyl phthalate resin, melamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin and the like can be used. The protective layer made of the thermosetting resin is formed by heating and curing the thermosetting resin precursor.

In order to improve the hardness of the formed protective layer, a silicone resin precursor is preferable as the thermosetting resin precursor, and among the silicone resin precursors, the thermosetting resin precursor composed of an alkoxysilane compound is the most. preferable.

Examples of the thermosetting resin precursor composed of the above alkoxysilane compound include "KP-86" (trade name) manufactured by Shinetsu Silicone Co., Ltd., "SHC-900" manufactured by Momentive Performance Materials Japan Co., Ltd., and "Tossguard 510". (Product name) and the like.

<Light diffusion layer>
The light diffusing layer is arranged on the side opposite to the side where the protective layer of the transparent base material is arranged, but is usually arranged directly on the transparent base material on the side opposite to the side where the protective layer is arranged. To. The light diffusing layer comprises a layer in which the first light diffusing filler is dispersed in a transparent resin.

The transparent resin generally has a refractive index different from that of the first light diffusing filler dispersed in the resin. The refractive index of the transparent resin is preferably selected in the range of 1.45 to 1.60. Further, the larger the absolute value of the difference between the refractive indexes of the transparent resin and the first light diffusing filler is, the more the light diffusing effect is obtained, so that the projectability and the angle dependence are excellent.

The transparent resin used for the light diffusion layer is not particularly limited as long as it has optical transparency, but is (meth) acrylic resin, acrylic urethane resin, polyester resin, polyester acrylate resin, polyurethane. (Meta) acrylate resin, epoxy (meth) acrylate resin, polyurethane resin, epoxy resin, polycarbonate resin, cellulose resin, acetal resin, vinyl resin, polyethylene resin, polystyrene resin, polypropylene resin , Polyethylene / vinyl acetate resin, polyamide resin, polyimide resin, melamine resin, phenol resin, silicone resin, fluororesin and other thermoplastic resins, thermosetting resin, ionizing radiation curable resin, and natural Known resins such as rubber-based, recycled rubber-based, chloroprene rubber-based, nitrile rubber-based, and styrene / butadiene rubber-based rubber-based resins can be preferably used. Further, in the transparent resin, one or more kinds of additives such as a cross-linking agent, an ultraviolet absorber, an antioxidant, an antistatic agent, a flame retardant, a plasticizer, and a colorant are added depending on the purpose. It may be a thing.

As the first light diffusing filler used for the light diffusing layer, if the difference in refractive index from the second light diffusing filler used for the light diffusing adhesive layer can be 0.50 or more, inorganic fine particles and organic fine particles can be used. Both can be used.

Examples of the inorganic fine particles include silica (refractive index: 1.46), alumina (refractive index: 1.77), rutile-type titanium dioxide (refractive index: 2.72), and anatase-type titanium dioxide (refractive index: 2.52). ), Zinc oxide (refractive index: 2.00), zinc sulfide, lead white (refractive index: 1.99), antimonides oxide, zinc antimonate, lead titanate, potassium titanate, barium titanate (refractive index: 2.41), zirconium oxide (refractive index: 2.21), cerium oxide, hafnium oxide (refractive index: 1.91), tantalum pentoxide, niobium pentoxide (refractive index: 2.32), yttrium oxide, oxidation Chromium, tin oxide (refractive index: 2.38), molybdenum oxide, indium tin oxide (refractive index: 1.86), antimony-doped tin oxide, calcium carbonate, talc, silicate glass, phosphate glass, hoe Conventionally known materials such as oxide glass such as acid salt glass, diamond (refractive index: 2.42), aluminum nitride (refractive index: 2.17), and silicon nitride (refractive index: 2.02) can be appropriately used. is there.

Among the above-mentioned inorganic fine particles, diamond, titanium oxide and zirconium oxide are preferable. This is because these inorganic fine particles have a refractive index in the range of 1.85 or more and less than 2.75. In particular, diamond having a higher refractive index is preferable. Among diamonds, polycrystalline diamond is more preferable in terms of dispersibility and cost. When polycrystalline diamond is used as the first light diffusible filler, the transparent resin is preferably a resin having a hydroxyl group such as a polyester resin. This is because polycrystalline diamond has high hydrophilicity and therefore has improved dispersibility with respect to a resin having a hydroxyl group.

Examples of the organic fine particles include an acrylic polymer, an acrylonitrile polymer, a styrene-acrylic copolymer, a vinyl acetate-acrylic copolymer, a vinyl acetate polymer, an ethylene-vinyl acetate copolymer, and a chlorinated polyolefin polymer. Multiple copolymers such as ethylene-vinyl acetate-acrylic, SBR, NBR, MBR, carboxylated SBR, carboxylated NBR, carboxylated MBR, polyvinyl chloride resin, polyvinylidene chloride resin, polyester resin, polyolefin resin , Polyurethane-based resin, Polymethacrylate-based resin, Polytetrafluoroethylene-based resin, Polymethylmethacrylate-based resin, Polycarbonate-based resin, Polypolyacetal-based resin, Rosin ester-based resin, Episulfide-based resin, Epoxy-based resin, Silicone-based resin, Conventionally known materials such as silicone-acrylic resin and melamine resin can be appropriately used.

The shape of the first light diffusing filler may be any shape such as spherical, flat, indefinite, star-shaped, and konpeito. Further, it may be hollow particles or core-shell particles. The light diffusing particles may be used alone or in combination of two or more.

The refractive index of the first light diffusing filler is preferably 1.85 or more and less than 2.75 as described above, and the average particle size of the first light diffusing filler is 0.05 as described above. It is preferably ~ 1.5 μm. Further, as described above, the content of the first light diffusing filler in the light diffusing layer is preferably 0.5 to 5.0% by mass with respect to the total solid content of the light diffusing layer. Further, the film thickness of the light diffusion layer is preferably 0.5 to 10.0 μm as described above.

The light diffusion layer may be formed on a transparent base material via an easy-adhesion layer, an adhesive layer, or the like.

The method for forming the light diffusion layer is not particularly limited, but the transparent resin is used as an organic solvent such as ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, xylene, or methanol. , It is preferable to form a coating material in which the first photodiffusible filler is dispersed in a solution dissolved in alcohol such as ethanol or water by applying and drying the coating on a transparent base material.

Dispersion of the first light diffusing filler in the transparent resin can be performed using various mixing / stirring devices and dispersion devices such as a dispenser, an agitator, a ball mill, an attritor, and a sand mill. Further, if necessary, a dispersant for the light diffusing filler may be added to disperse. The paint in which the light diffusing filler is dispersed is preferably defoamed before coating in order to prevent bubbles from remaining in the light diffusing layer after coating and drying.

The coating of the paint in which the first light diffusing filler is dispersed can be performed using a coater such as a die coater, a comma coater, a reverse coater, a dam coater, a doctor bar coater, a gravure coater, a micro gravure coater, or a roll coater. it can.

<Light diffusion adhesive layer>
The light diffusing adhesive layer is arranged outside the light diffusing layer, but is usually formed directly on the light diffusing layer. The light diffusing adhesive layer comprises a layer in which a second light diffusing filler is dispersed in a pressure-sensitive adhesive.

As the material of the pressure-sensitive adhesive, a material having a high visible light transmittance and a small difference in refractive index from the transparent base material is preferably used. Examples thereof include resins such as acrylic resins, silicone resins, polyester resins, epoxy resins, and polyurethane resins. In particular, acrylic resins have high optical transparency, wettability and adhesiveness. It is more preferably used because it has a good balance of forces, is highly reliable and has a good track record, and is relatively inexpensive.

Examples of the acrylic pressure-sensitive adhesive include homopolymers of acrylic monomers such as acrylic acid and its esters, methacrylic acid and its esters, acrylamide, and acrylonitrile, or copolymers thereof, and at least one of the above acrylic monomers and acetic acid. Examples thereof include copolymers with vinyl monomers such as vinyl, maleic anhydride, and styrene. The Tg (glass transition temperature) of the acrylic pressure-sensitive adhesive is preferably in the range of -60 ° C to -10 ° C and has a weight average molecular weight in the range of 100,000 to 2,000,000, particularly 500,000. Those in the range of ~ 1,000,000 are more preferable. As the acrylic pressure-sensitive adhesive, one or a mixture of two or more cross-linking agents such as isocyanate-based, epoxy-based, and metal chelating-based adhesives can be used, if necessary.

As the second light diffusing filler used for the light diffusing adhesive layer, if the difference in refractive index from the first light diffusing filler used for the light diffusing layer can be 0.50 or more, the above-mentioned first light Both inorganic fine particles and organic fine particles that can be used as a diffusible filler can be used.

As described above, the refractive index of the second light diffusing filler is preferably 1.20 or more and less than 1.50, the second light diffusing filler is spherical, and its average particle size is as described above. As shown above, it is preferably 0.1 to 1.5 μm. Further, as described above, the content of the second light diffusing filler in the light diffusing adhesive layer is preferably 0.2 to 5.0% by mass with respect to the total solid content of the light diffusing adhesive layer. .. Further, the film thickness of the light diffusion adhesive layer is preferably 10 to 50 μm as described above.

The method for forming the light-diffusing adhesive layer is not particularly limited, but a coating material obtained by adding a light-diffusing filler to a solution of the pressure-sensitive adhesive in an organic solvent and dispersing it is prepared. Using a coater such as a die coater, a comma coater, a reverse coater, a dam coater, a doctor bar coater, a gravure coater, a micro gravure coater, or a roll coater, first apply the paint on the release film, dry it, and then apply light diffusion adhesive. It is preferable to form the exposed surface of the layer by a method of bonding it to the surface of the light diffusion layer.

Next, an example of the screen film of the present embodiment will be described based on the drawings.

FIG. 1 is a schematic cross-sectional view showing an example of the screen film of the present embodiment. In FIG. 1, the screen film 10 includes a transparent base material 11, a protective layer 12, a light diffusing layer 13, and a light diffusing adhesive layer 14. The light diffusing layer 13 contains a first light diffusing filler and a resin, and the light diffusing adhesive layer 14 contains a second light diffusing filler and an adhesive, and has a refractive index of the first light diffusing filler. And the difference between the refractive index and the refractive index of the second light diffusing filler is set to 0.50 or more.

In the screen film 10, the light diffusing layer 13 is arranged between the transparent base material 11 and the light diffusing adhesive layer 14, and the protective layer 12 is the surface of the transparent base material 11 on which the light diffusing layer 13 is formed. Since it is arranged on the opposite side to the screen film 10, the scratch resistance of the screen film 10 can be improved. Further, since the difference between the refractive index of the first light diffusing filler and the refractive index of the second light diffusing filler is set to 0.50 or more, the optical characteristics and projectivity of the screen film 10 are improved. it can.

Although not shown in FIG. 1, by arranging a release layer made of a release film on the outer surface of the light diffusion adhesive layer 14, the handleability of the screen film before the screen film 10 is attached to a glass substrate or the like is improved. Can be done.

(Projection system)
Next, an embodiment of the projection system disclosed in the present application will be described. The projection system of the present embodiment includes the screen film disclosed in the above embodiment and a projector that projects an image on the screen film. Since the projection system of this embodiment includes the screen film disclosed in the above embodiment, it is excellent in projectivity and angle dependence as shown in Examples described later.

The projection system may also include, for example, a transmission device that transmits video data to the projector, a control device that controls the projector, and the like.

Hereinafter, the screen film disclosed in the present application will be described based on the examples. However, the screen film disclosed in the present application is not limited to the following examples.

(Example 1)
<Formation of protective layer>
First, as a transparent base material, a polyethylene terephthalate (PET) film "A4300" (trade name, thickness: 50 μm) manufactured by Toyobo Co., Ltd., which had both sides easily bonded, was prepared. Next, using a microgravure coater (manufactured by Yasui Seiki Co., Ltd.) on one side of the PET film, a hard coat paint "LCH2500" (trade name) manufactured by Toyochem Co., Ltd. is applied to a thickness of 3 μm after drying. After coating and drying, a PET film A with a protective layer having a thickness of 3 μm was formed by irradiating with an ultraviolet ray having a light amount of ^{300 mJ / cm 2 with a high-pressure mercury lamp and curing the film.}

<Formation of light diffusion layer>
Add 98.5 parts of pure water to 1.5 parts of polycrystalline diamond particles "DPC-0-2" (trade name, refractive index: 2.41) manufactured by Vision Development Co., Ltd., and add 98.5 parts of pure water to the ultrasonic disperser "UH-600". A diamond dispersion was prepared by performing a dispersion treatment at a liquid temperature of 30 ° C. and a pulse rate of 70% for 1 hour at "(trade name, manufactured by SMT).

Next, 39 parts of a polyester resin solution "Plus Coat RZ-105" (trade name, refractive index: 1.52, solid content concentration: 25% by mass) manufactured by GOO CHEMICAL CO., LTD. 40 parts of water and 5 parts of methanol were added, mixed and mixed with a disper, and then passed through a filter having a diameter of 5 μm to prepare a coating solution for forming a light diffusion layer. When the average particle size of the polycrystalline diamond in this coating liquid was measured by a laser diffraction / scattering type particle size distribution meter "LA-960V2" manufactured by HORIBA, the average dispersed particle size was 0.8 μm. The solid content concentration of the coating liquid was 10.0% by mass, and the filler content with respect to the total solid content was 2.4% by mass.

The coating liquid for forming the light diffusion layer is applied using a gravure coater to the opposite side of the surface on which the protective layer of the PET film A with the protective layer is formed so that the thickness after drying is 3 μm and dried. By doing so, the light diffusion layer A was formed.

<Formation of light diffusion adhesive layer>
First, as a release film, a PET film "J0-L" (trade name, thickness: 38 μm) manufactured by Nipper, which had one side treated with silicone, was prepared. In addition, Momentive Performance Materials Japan for 100 parts of the acrylic adhesive solution "SK Dyne 2094" (trade name, solid content concentration: 25% by mass, refractive index: 1.49) manufactured by Soken Kagaku Co., Ltd. Spherical silicone resin fine particles "XC99-A8808" (trade name, average particle diameter: 0.7 μm, refractive index: 1.42) 0.50 parts [3.5 parts for 100 parts of adhesive resin], Add 1.25 parts of an ultraviolet absorber (benzophenone type) manufactured by Wako Junyaku Co., Ltd. and 0.27 parts of a cross-linking agent "E-AX" (trade name, solid content concentration: 5% by mass) manufactured by Soken Kagaku Co., Ltd. After being dispersed and blended with a disper, defoaming was performed to prepare a coating solution for forming a light diffusing adhesive layer. The solid content concentration of this coating liquid was 26.2% by mass, and the filler content with respect to the total solid content was 1.9% by mass.

Next, the coating liquid for forming the light diffusing adhesive layer is applied to the surface of the release PET film on the silicone-treated side using a die coater so that the thickness after drying is 28 μm, and dried. By doing so, the light diffusing adhesive layer A was formed. Further, the light diffusing layer A prepared above is attached to the exposed surface of the light diffusing adhesive layer A, and the light diffusing adhesive layer A, the light diffusing layer A, and the protective layer are provided on the other surface of the PET film. The formed transparent screen film of Example 1 was produced.

(Example 2)
The dispersion time of the polycrystalline diamond "DPC-0-2" at the time of forming the light diffusion layer A was changed to 2.0 hours, and after the dispersion, the centrifuge "H-9R" (trade name, manufactured by Kokusan Co., Ltd.) was used. A diamond dispersion was prepared in the same manner as in Example 1 except that centrifugation was performed at 25 ° C. and 8000 rpm for 5 minutes using an LN rotor. The solid content concentration after centrifugation was 1.0% by mass.

A coating liquid for forming a light diffusion layer was prepared in the same manner as in Example 1 except that 16 parts of the above dispersion was used. The average dispersed particle size of diamond measured in the same manner as in Example 1 of this coating liquid was 0.3 μm, the solid content concentration was 10.0% by mass, and the filler content with respect to the total solid content was 2.4% by mass. It was. The light diffusing layer B was formed in the same manner as in Example 1 except that the coating liquid for forming the light diffusing layer was used. The light diffusing adhesive layer A was attached to the light diffusing layer B in the same manner as in Example 1 to prepare a transparent screen film of Example 2.

(Example 3)
A coating liquid for forming a light diffusion layer was prepared in the same manner as in Example 1 except that the dispersion time of the polycrystalline diamond “DPC-0-2” at the time of forming the light diffusion layer A was changed to 0.5 hours. The average dispersed particle size of diamond measured in the same manner as in Example 1 of this coating liquid was 1.2 μm, the solid content concentration was 10.0% by mass, and the filler content with respect to the total solid content was 2.4% by mass. It was. The light diffusing layer C was formed in the same manner as in Example 1 except that the coating liquid for forming the light diffusing layer was used. The light diffusing adhesive layer A was attached to the light diffusing layer C in the same manner as in Example 1 to prepare a transparent screen film of Example 3.

(Example 4)
The light diffusion layer D was formed in the same manner as in Example 1 except that the film thickness of the light diffusion layer A was changed to 1 μm. The light diffusing adhesive layer A was attached to the light diffusing layer D in the same manner as in Example 1 to prepare a transparent screen film of Example 4.

(Example 5)
The light diffusion layer E was formed in the same manner as in Example 1 except that the film thickness of the light diffusion layer A was changed to 8 μm. The light diffusing adhesive layer A was attached to the light diffusing layer E in the same manner as in Example 1 to prepare a transparent screen film of Example 5.

(Example 6)
Instead of the spherical silicone resin particles "XC99-8808" of the coating liquid for forming the light diffusing adhesive layer, the spherical silicone resin dispersion "SCK-010MW" manufactured by Chugoku Kako Co., Ltd. (trade name, primary particle diameter: 0.1 μm, The light diffusing adhesive layer B was formed in the same manner as in Example 1 except that the refractive index: 1.42) was replaced with the same amount of the solid content concentration of the silicone resin. The light diffusing layer A was attached to the light diffusing adhesive layer B in the same manner as in Example 1 to prepare a transparent screen film of Example 6.

(Example 7)
Instead of the spherical silicone resin particles "XC99-8808" of the coating liquid for forming the light diffusing adhesive layer, the spherical silicone resin dispersion "SCK-100MW" manufactured by Chugoku Kako Co., Ltd. (trade name: primary particle diameter: 1.1 μm, The light diffusing adhesive layer C was formed in the same manner as in Example 1 except that the refractive index: 1.42) was replaced with the same amount of the solid content concentration of the silicone resin. The light diffusing layer A was attached to the light diffusing adhesive layer C in the same manner as in Example 1 to prepare a transparent screen film of Example 7.

(Example 8)
Except for using 4.7 parts of the diamond dispersion obtained in Example 1, 39.7 parts of the polyester resin solution "Pluscoat RZ-105", 50.6 parts of pure water, and 5 parts of methanol. A coating solution for forming a light diffusion layer was prepared in the same manner as in Example 1. The average dispersed particle size of diamond measured in the same manner as in Example 1 of this coating liquid was 0.8 μm, the solid content concentration was 10.0% by mass, and the filler content with respect to the total solid content was 0.7% by mass. It was. The light diffusing layer F was formed in the same manner as in Example 1 except that the coating liquid for forming the light diffusing layer was used. The light diffusing adhesive layer A was attached to the light diffusing layer F in the same manner as in Example 1 to prepare a transparent screen film of Example 8.

(Example 9)
Except for using 31.3 parts of the diamond dispersion obtained in Example 1, 38.1 parts of the polyester resin solution "Pluscoat RZ-105", 25.6 parts of pure water, and 5 parts of methanol. A coating solution for forming a light diffusion layer was prepared in the same manner as in Example 1. The average dispersed particle size of diamond measured in the same manner as in Example 1 of this coating liquid was 0.8 μm, the solid content concentration was 10.0% by mass, and the filler content with respect to the total solid content was 4.7% by mass. It was. The light diffusing layer G was formed in the same manner as in Example 1 except that the coating liquid for forming the light diffusing layer was used. The light diffusing adhesive layer A was attached to the light diffusing layer G in the same manner as in Example 1 to prepare a transparent screen film of Example 9.

(Example 10)
Instead of polycrystalline diamond "DPC-0-2", 30.0 parts of titanium oxide "TTO-55" (trade name, refractive index: 2.72) manufactured by Ishihara Sangyo Co., Ltd., and 68.5 parts of pure water , Add 1.5 parts of Big Chemie's polymer dispersant "Dyspa-BYK180" (trade name) as a dispersant, put this in a 250 ml PP container, and add 200 g of zirconia beads with a diameter of 0.1 mm to a paint conditioner (Toyo). It was dispersed for 30 minutes in (manufactured by Seiki). After the dispersion, centrifugation was performed at 25 ° C. and 8000 rpm for 5 minutes using an LN rotor in a centrifuge "H-9R" to prepare a dispersion. The solid content concentration after centrifugation was 28.0% by mass. To 0.9 parts of this dispersion, 39 parts of polyester resin solution "Pluscoat RZ-105", 55.1 parts of pure water, and 5 parts of methanol were added, mixed and mixed with a disper, and then a filter having a diameter of 5 μm. A coating solution for forming a light diffusion layer was prepared by passing through. When the average particle size of titanium oxide in this coating liquid was measured with a laser diffraction / scattering type particle size distribution meter "LA-960V2" manufactured by HORIBA, the average dispersed particle size was 1.0 μm. The solid content concentration of the coating liquid was 10.0% by mass, and the filler content with respect to the total solid content was 2.5% by mass. The light diffusing layer H was formed in the same manner as in Example 1 except that the coating liquid for forming the light diffusing layer was used. The light diffusing adhesive layer A was attached to the light diffusing layer H in the same manner as in Example 1 to prepare a transparent screen film of Example 10.

(Example 11)
Instead of polycrystalline diamond "DPC-0-2", an aqueous dispersion of zirconium oxide "SZR-W" manufactured by Sakai Chemical Co., Ltd. (trade name, refractive index: 2.11, solid content concentration: 30% by mass) 1 To 0.0 parts, add 38.8 parts of polyester resin solution "Pluscoat RZ-105", 55.2 parts of pure water, and 5 parts of methanol, mix and mix with a dispersion, and then apply a filter with a diameter of 5 μm. By passing it through, a coating solution for forming a light diffusion layer was prepared. When the average particle size of zirconium oxide in this coating liquid was measured with a laser diffraction / scattering type particle size distribution meter "LA-960V2" manufactured by HORIBA, the average dispersed particle size was 0.2 μm. The solid content concentration of the coating liquid was 10.0% by mass, and the filler content with respect to the total solid content was 3.0% by mass. The light diffusing layer I was formed in the same manner as in Example 1 except that the coating liquid for forming the light diffusing layer was used. The light diffusing adhesive layer A was attached to the light diffusing layer I in the same manner as in Example 1 to prepare a transparent screen film of Example 11.

(Comparative Example 1)
The adhesive layer D was formed in the same manner as in Example 1 except that the spherical silicone resin fine particles “XC99-A8808” were removed from the light diffusing adhesive layer A instead of the light diffusing adhesive layer A of Example 1. A light diffusing layer A was attached to the adhesive layer D in the same manner as in Example 1 to prepare a transparent screen film of Comparative Example 1.

(Comparative Example 2)
A comparative example in which a light diffusing adhesive layer A prepared in the same manner as in Example 1 is attached to the PET film A with a protective layer produced in Example 1 instead of the light diffusing layer A, and the light diffusing layer is not included. No. 2 transparent screen film was produced.

(Comparative Example 3)
The coating liquid for forming a light diffusing layer prepared in Example 1 is applied to a PET film "A4300" which is a transparent base material so as to have a thickness of 3 μm in the same manner as in Example 1, and then dried. A protective layer was formed on the protective layer in the same manner as in Example 1 to form a PET film B with a protective layer. Instead of the light diffusing layer A, the light diffusing adhesive layer A produced in the same manner as in Example 1 is bonded to the PET film B with the protective layer, and the light diffusing layer is formed on the opposite side of the light diffusing adhesive layer A. Further, a transparent screen film of Comparative Example 3 was produced.

(Comparative Example 4)
Instead of the spherical silicone resin fine particles "XC99-A8808" used in the light diffusing adhesive layer A of Example 1, zinc oxide manufactured by Sakai Chemical Co., Ltd. (grade: 1 type, primary particle size: 0.75 μm, refractive index: The light diffusing adhesive layer E was formed in the same manner as in Example 1 except that 2.00) was used. The light diffusing layer I of the PET film A with the protective layer / light diffusing layer prepared in Example 11 is attached to the light diffusing adhesive layer E in the same manner as in Example 1, and the light diffusing layer I and the light diffusing adhesive layer are attached. A transparent screen film of Comparative Example 4 in which the difference in refractive index of the light diffusing filler contained in E was less than 5.0 was produced.

<Evaluation of transparent screen film>
The optical characteristics, projectivity, angle dependence and scratch resistance of Examples 1 to 11 and Comparative Examples 1 to 4 were evaluated as follows.

[optical properties]
In order to evaluate the optical characteristics, the total light transmittance and the haze value were measured as follows. A transparent screen film is attached to 3 mm float glass, and the translucency is measured using a haze meter "NDH2000" (trade name) manufactured by Nippon Denshoku Co., Ltd. with the glass surface as the incident light side, and conforms to JIS K7136-2000. The total light transmittance and the haze value were calculated.

[Projectiveness]
In order to evaluate the projectability, the brightness of the image projected on the transparent screen film by the projector was measured as follows.

As the projector, an ultra-short projection projector "MP-TW4011" using a laser light source manufactured by Maxell was used. The output of the projector is set to the standard mode, the brightness, contrast, and color depth are all set to the initial values, the image quality setting is set to 4, the video mode is "standard", ACCENTUALIZER "3", HDCR "3", and dynamic black is "effective". Each was set to and projected.

The brightness was measured according to the following procedure. First, the transparent screen film is attached to a transparent polycarbonate plate (model number: PCTA) manufactured by MISUMI with a thickness of 5 mm by watering so that air bubbles do not enter, and then cured at room temperature for 3 days to cure the transparent screen plate. Got

Next, as shown in FIG. 2, the screen film side of the transparent screen plate 30 composed of the transparent screen film 10 and the transparent polycarbonate plate 20 is installed on the projector 40 side, and the horizontal distance from the light source of the projector 40 to the transparent screen plate 30. The brightness of the measurement point was measured from the side opposite to the projector 40 by irradiating the projected light 50 from the projector 40 with the vertical distance from the light source to the measurement point being 450 mm. As the luminance meter 60, a color luminance meter “BM-7” manufactured by TOPCON was used, and the distance from the measurement point to the lens of the luminance meter 60 was set to 300 mm. All measurements were performed in a dark room, and white and black images were created with Microsoft's "PowerPoint" for the projected images, and these were projected to measure the brightness of the white and black.

The projectiveness was evaluated according to the following criteria.

It can be said that the higher the brightness at the time of white projection, the brighter the screen and the clearer the image can be provided. Therefore, luminance in white projections, 50 cd / m ² or more good (〇) ones, good ones ^{30 ~ 50cd / m 2 (△} ), was as bad (×) of lower than 30 cd / m ² ..

When the brightness at the time of black projection is high, a whitish image is likely to be obtained at the time of image projection, and it can be said that a screen capable of providing a high contrast image when the brightness at the time of black projection is low. Therefore, luminance in the black projections, good (〇) those less than 0.13cd / m ^2, a good but less than 0.13 or more ^{0.16cd / m 2 (△),} 0.16cd / m 2 or more Those were regarded as defective (x).

[Angle dependence]
The angle dependence of the transparent screen film was evaluated by projecting an image on a transparent screen plate with a projector in the same manner as the evaluation of projectability, and evaluating the image in the following three stages.
Excellent (○): When the image can be clearly recognized even when observing while changing the viewing angle Good (△): When observing while changing the viewing angle, there are some parts where the image can be recognized and some parts which are a little difficult to recognize. (×): When there are places where the image is difficult to recognize when observing while changing the viewing angle

[Scratch resistance]
A transparent screen film is attached to 3 mm float glass, and steel wool (# 0000) is fixed to the tip of a sliding part with a diameter of 15 mm using a sliding tester "HEIDON" manufactured by Shinto Kagaku Co., Ltd., and a load of 883 g is applied. After sliding the film surface 10 times back and forth at 4500 mm / min in this state, an image was projected on a transparent screen plate with a projector in the same manner as in the evaluation of projectivity, and the white brightness before and after sliding was measured. As a result, those having a brightness change rate of less than 10% as compared with the initial stage were regarded as excellent (◯), and those having a brightness change rate of 10% or more were regarded as defective (x).

The above results are shown in Tables 1 to 3. In addition, Tables 1 to 3 also show the layer structure of the transparent screen film and the difference in refractive index between the light diffusing filler of the light diffusing layer and the light diffusing filler of the light diffusing adhesive layer.

From the above evaluation results, the layer structure is a protective layer / PET film / light diffusing layer / light diffusing adhesive layer, and the difference in refractive index between the light diffusing filler of the light diffusing layer and the light diffusing filler of the light diffusing adhesive layer is 0. It can be seen that in Examples 1 to 11 having a value of .50 or more, almost satisfactory evaluations were obtained in all of the optical characteristics, projectivity, angle dependence and scratch resistance.

On the other hand, in Comparative Example 1 in which the adhesive layer was formed instead of the light diffusing adhesive layer, the white brightness was inferior, and in Comparative Example 2 in which the light diffusing layer was not formed, the white brightness and the angle dependence were inferior, and the light diffusing layer was formed. In Comparative Example 3 arranged between the protective layer and the transparent base material, the scratch resistance was inferior, and the difference in refractive index between the light diffusing filler of the light diffusing layer and the light diffusing filler of the light diffusing adhesive layer was 0.50. In Comparative Example 4, which was lower than that, the black brightness was inferior.

The present application can be implemented in a form other than the above as long as the purpose is not deviated. The embodiments disclosed in the present application are examples, and the present invention is not limited thereto. The scope of the present application shall be construed in preference to the description of the appended claims over the description of the specification described above, and all changes within the scope of the claims shall be included in the scope of the claims. It is something that can be done.

The screen film disclosed in the present application is excellent in optical characteristics, projectivity and scratch resistance, has a transmissive screen function and a reflective screen function, and can be applied to various transparent screens.

10 Screen film 11 Transparent base material 12 Protective layer 13 Light diffusion layer 14 Light diffusion adhesive layer 20 Transparent polycarbonate plate 30 Transparent screen plate 40 Projector 50 Projected light 60 Brightness meter

Claims

A screen film including a transparent base material, a protective layer, a light diffusing layer, and a light diffusing adhesive layer.
The protective layer is arranged on one main surface side of the transparent base material.
The light diffusing layer and the light diffusing adhesive layer are arranged in this order from the other main surface side of the transparent base material.
The light diffusing layer contains a first light diffusing filler and a resin.
The light diffusing adhesive layer contains a second light diffusing filler and an adhesive.
A screen film in which the difference between the refractive index of the first light diffusing filler and the refractive index of the second light diffusing filler is 0.50 or more.
The screen film according to claim 1, wherein the total light transmittance is 60 to 90% and the haze value is 5.0 to 30.0%.
The screen film according to claim 1 or 2, wherein the protective layer contains an ionizing radiation curable resin or a thermosetting resin.
The screen film according to any one of claims 1 to 3, wherein the refractive index of the first light diffusing filler is 1.85 or more and less than 2.75.
The screen film according to any one of claims 1 to 4, wherein the average particle size of the first light diffusing filler is 0.05 to 1.5 μm.
The screen film according to any one of claims 1 to 5, wherein the first light diffusing filler is at least one selected from the group consisting of diamond, titanium oxide and zirconium oxide.
The screen according to any one of claims 1 to 6, wherein the content of the first light diffusing filler is 0.5 to 5.0% by mass with respect to the total solid content of the light diffusing layer. the film.
The screen film according to any one of claims 1 to 7, wherein the film thickness of the light diffusion layer is 0.5 to 10.0 μm.
The screen film according to any one of claims 1 to 8, wherein the refractive index of the second light diffusing filler is 1.20 or more and less than 1.50.
The screen film according to any one of claims 1 to 9, wherein the second light diffusing filler is spherical and has an average particle size of 0.1 to 1.5 μm.
The content of any one of claims 1 to 10, wherein the content of the second light diffusing filler is 0.2 to 5.0% by mass with respect to the total solid content of the light diffusing adhesive layer. Screen film.
The screen film according to any one of claims 1 to 11, wherein the light diffusing adhesive layer contains an acrylic pressure-sensitive adhesive.
The screen film according to any one of claims 1 to 12, wherein the light diffusion adhesive layer has a film thickness of 10 to 50 μm.
A projection system including the screen film according to any one of claims 1 to 13 and a projector.