JP4777441B2 - Transmission screen - Google Patents

Description

  The present invention relates to a transmission screen that can visually recognize an image from the front when an image from a projector is projected onto the back.

  Conventionally, transmissive screens using a polarizing film, a Fresnel lens sheet, a lenticular lens sheet, etc. have been put into practical use in order to achieve high brightness and high contrast. However, such a conventional transmission type screen is expensive because it uses a polarizing film or a lens sheet. In addition, an advertising method in which a transparent screen is pasted on the show window and a dynamic advertisement is projected onto the projector is conceivable. However, the conventional transmissive screen has no transparency, so the product cannot be seen from the outside. The problem was that the meaning of the show window disappeared.

  Accordingly, various proposals have been made to solve the above problems.

  In Patent Document 1, in order to improve the background visibility, a transmissive screen has transparency and a part having light diffusibility composed of transparent spherical fine particles and a transparent binder having a refractive index different from that of the spherical fine particles. It is disclosed that a configuration is formed by mixing the portions periodically or randomly.

  In Patent Document 2, in order to improve the background visibility, the transmissive screen includes spherical dielectric particles having a particle diameter sufficiently larger than the wavelength of light, and almost all incident light is in front of the traveling direction. It is disclosed to provide a forward-scattering light scattering layer having the property of being scattered and not scattered backwards.

Patent Document 3 discloses a light diffusing material comprising a resin film in which a light reflection preventing layer is provided on the front surface of a glass substrate and a diffusing agent is contained in the resin on the back surface of the glass substrate as a transmissive screen used in a rear projection type projection television. A transmission screen with a layer is disclosed.
JP 2006-133636 A JP 2001-242546 A JP-A-2005-250124

  However, the image obtained with the conventional transmission screen is not satisfactory in terms of contrast and lacks clarity.

  The object of the present invention is to allow the projector side to visually recognize the background of the screen without the image being projected on the screen, and from the opposite side of the projector to project a clear image with high contrast on the screen. It is an object of the present invention to provide a transmission screen that can visually recognize both an image and a background of the screen.

  The inventor of the present invention has the above-described problem by including a light scattering agent having a predetermined concentration in each of the base material layer and the main light scattering layer in the transmission screen composed of the laminated structure including the base material layer and the main light scattering layer. The present invention has been completed by finding that it can be solved.

  That is, the present invention is as described below.

(1) A main light scattering layer containing a first light scattering agent and a second light scattering agent formed on the main light scattering layer and having a lower concentration than the concentration of the first light scattering agent. a transmission type screen comprising a laminate comprising a substrate layer, the light transmittance of the laminate direction of the laminate is 70% contrast is 600: 1 or more der is, the main light-scattering layer The concentration of the first light scattering agent is 10 to 3000 ppm, and the concentration of the second light scattering agent in the base material layer is 0.1 to 4.5 ppm . The concentration of the first light scattering agent is based on the total mass of the main light scattering layer, and the concentration of the second light scattering agent is based on the total mass of the base material layer.

(2) The transmissive screen according to (1 ), wherein the main light scattering layer includes a first light-transmitting resin as a constituent component, and the base material layer includes a second light-transmitting resin as a constituent component.

(3) The transmission screen according to (2 ), wherein the first light transmitting resin and / or the second light transmitting resin is a methacrylic resin.

(4) Ratio (C ₁ / C) of the concentration (C ₁ ) of the first light scattering agent in the main light scattering layer to the concentration (C ₂ ) of the second light scattering agent in the base material layer The transmission screen according to any one of claims 1 to 3, wherein ₂ ) is 20/1 to 2000/1.

(5) The ratio (T ₁ / T ₂ ) of the thickness (T ₁ ) of the main light scattering layer to the thickness (T ₂ ) of the base material layer is 1/300 to 1/7. The transmissive screen according to any one of (4 ) to (4) .

(6) the main light-scattering layer has no film-like, in any one of the base layer is 1 to claim which is formed on one or both major surfaces of the main light-scattering layer (5) The transmissive screen as described.

  The transmissive screen of the present invention can produce a clear image with high contrast and has an effect of being excellent in background visibility. In addition, the addition of a light scattering agent to the base material layer has a favorable effect in terms of increasing the luminance uniformity of the image.

It is a perspective view of the transmission type screen concerning a 1st embodiment. It is sectional drawing which shows the use condition of the transmission type screen which concerns on 1st Embodiment. It is a perspective view of the transmission type screen concerning a 2nd embodiment. It is sectional drawing which shows the use condition of the transmission type screen which concerns on 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Main light scattering layer, 2 ... Base material layer, 3 ... Projector, 10 ... Transmission type screen which concerns on 1st Embodiment, 11 ... Transmission type screen which concerns on 2nd Embodiment .

  Hereinafter, preferred embodiments will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the drawings are exaggerated for easy understanding, and the dimensional ratios do not necessarily match those described.

  FIG. 1 is a perspective view of a transmission screen according to the first embodiment. A transmission screen 10 according to the first embodiment shown in FIG. 1 includes a main light scattering layer 1 and a base material layer 2 formed on the main light scattering layer 1. In the transmissive screen 10 according to the first embodiment, the main surface of the base material layer 2 (the main surface not in contact with the main light scattering layer 1) corresponds to the back surface on which an image is projected, and main light scattering is performed. The main surface of layer 1 (the main surface not in contact with base material layer 2) corresponds to the front surface for observing the image.

  The main light scattering layer 1 contains a first light scattering agent, and the substrate layer 2 contains a second light scattering agent. However, the concentration of the second light scattering agent in the base material layer 2 (the mass of the second light scattering agent based on the total mass of the base material layer 2) is the same as that of the first light scattering agent in the main light scattering layer 1. The concentration is lower than the concentration (the mass of the first light scattering agent based on the total mass of the main light scattering layer 1).

  FIG. 2 is a cross-sectional view showing a usage state of the transmissive screen 10 according to the first embodiment, and an image of the projector 3 is projected from the rear surface of the transmissive screen 10 (the main surface of the base material layer 2), that is, from the projector side. The projected image reaches the front surface of the transmissive screen 10 (the main surface of the main light scattering layer 1), that is, the image viewer side.

  FIG. 3 is a perspective view of a transmission screen according to the second embodiment. The transmissive screen 11 according to the second embodiment shown in FIG. 3 has the base material layer 2 formed on both sides of the main surface of the main light scattering layer 1. In the transmissive screen 11 according to the second embodiment, the main surface of one base material layer 2 (the main surface not in contact with the main light scattering layer 1) corresponds to the back surface on which the image is projected, and the other The main surface of the substrate layer 2 (the main surface not in contact with the main light scattering layer 1) corresponds to the front surface for observing the image.

  The main light scattering layer 1 contains a first light scattering agent, and the substrate layer 2 contains a second light scattering agent. However, as in the first embodiment, the concentration of the second light scattering agent in the substrate layer 2 (the mass of the second light scattering agent based on the total mass of the substrate layer 2) is the main light scattering. The concentration is lower than the concentration of the first light scattering agent in the layer 1 (the mass of the first light scattering agent based on the total mass of the main light scattering layer 1).

  FIG. 4 is a cross-sectional view showing a usage state of the transmissive screen 11 according to the second embodiment, and an image of the projector 3 is displayed from the rear surface (the main surface of one base material layer 2) of the transmissive screen 11, that is, from the projector side. The projected image reaches the front surface of the transmission screen 11 (the main surface of the other base material layer 2)), that is, the image observer side.

  Since the transmissive screen 10 according to the first embodiment and the transmissive screen 11 according to the second embodiment have the above-described configuration, the projector can visually recognize the background of the screen without displaying an image on the screen. From the opposite side of the projector, a clear image with high contrast can be projected on the screen, and the screen image and the screen background can be viewed together.

  The main light scattering layer 1 is preferably composed of the first light-transmitting resin, and the base material layer 2 is preferably composed of the second light-transmitting resin. That is, the main light scattering layer 1 preferably contains a light transmissive resin and a first light scattering agent, and the base material layer 2 contains a second light transmissive resin and a second light scattering agent. preferable. The first light scattering agent and the second light scattering agent may be the same or different, and the first light transmitting resin and the second light transmitting resin may be the same or different. May be.

  As the first light transmissive resin and the second light transmissive resin, various thermoplastic resins can be applied, but preferably a methacrylic resin, a polycarbonate resin, a styrene resin, a cyclic olefin resin, an amorphous resin. An optical material such as a polyester resin, more preferably a methacrylic resin.

  Here, a methacrylic resin means what can be obtained by copolymerizing 70 weight% or more of methyl methacrylate or ethyl methacrylate, and the monomer which has a copolymerizability with these.

  Examples of monomers copolymerizable with methyl methacrylate or ethyl methacrylate include butyl methacrylate, ethyl methacrylate, methyl methacrylate, propyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, and 2-ethylhexyl methacrylate. Applicable to acrylic acid esters such as methacrylic acid esters, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, 2-ethylhexyl acrylate, unsaturated acids such as methacrylic acid, acrylic acid, etc. Is possible.

  As the first light transmissive resin and the second light transmissive resin, heat-resistant methacrylic resin, low-hygroscopic methacrylic resin, impact-resistant methacrylic resin, and the like are also applicable. The impact-resistant methacrylic resin refers to a methacrylic resin with improved impact resistance. For example, a methacrylic resin is blended with a rubber elastic body. An example of the rubber elastic body is a multistage polymer produced by a multistage sequential polymerization method in which an elastic layer and an inelastic layer are alternately generated around an acrylic polymer core material. By blending this rubber elastic body with a methacrylic resin, an impact-resistant methacrylic resin can be obtained.

  When a polycarbonate resin is used as the first light transmissive resin and the second light transmissive resin, a polymer derived from a dihydric phenol compound represented by bisphenol A may be used as the polycarbonate resin. preferable. The production method of the polycarbonate resin is not particularly limited, and production methods such as a phosgene method, a transesterification method, or a solid phase polymerization method can be applied.

  The cyclic olefin resin used as the first light transmissive resin and the second light transmissive resin is a polymer containing a cyclic olefin skeleton in a polymer chain such as norbornene or cyclohexadiene, or a copolymer containing these. Yes, it belongs to amorphous thermoplastic resin. The manufacturing method is not particularly limited. For example, as an example of a cyclic olefin resin mainly composed of norbornene, “Topas” (trade name) manufactured by Ticona Co., Ltd., which is an ethylene-norbornene copolymer, can be applied. As an example of a cyclopentadiene ring-opening polymer, Is applicable to “Zeonex” (trade name) manufactured by Nippon Zeon Co., Ltd.

  The styrenic resin used as the first light-transmitting resin and the second light-transmitting resin is a homopolymer, a copolymer or a polymer blend obtained from these polymers and other resins. is there. In the present invention, it is particularly preferable to use an ABS resin which is a copolymer resin of polystyrene, acrylonitrile and styrene, or an MS resin which is a copolymer resin of methacrylic acid ester and styrene (hereinafter referred to as methacrylic acid ester and styrene resin). The copolymer may be referred to as “MS”). Further, transparent reinforced polystyrene in which rubber is distributed in the styrene resin phase can be preferably used. There is no restriction | limiting in particular in the manufacturing method of a styrene-type resin.

  Examples of the amorphous polyester used as the first light transmissive resin and the second light transmissive resin include aliphatic glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, and hexamethylene glycol. , Alicyclic glycols such as cyclohexanedimethanol, bisphenol, aromatic dihydroxy compounds such as 1,3-bis (2-hydroxyethoxy) benzene, 1,4-bis (hydroxyethoxy) benzene, or two or more of these Selected dihydroxy compound units and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and 2,6-naphthalene dicarboxylic acid, and aliphatic dicarboxylic acids such as oxalic acid, adipic acid, sebacic acid, succinic acid and undecadicarboxylic acid , Alicyclic rings such as hexahydroterephthalic acid Dicarboxylic acid, or a polyester formed from dicarboxylic acid units selected from two or more of these and can be applied to amorphous resin.

  The method for producing the amorphous polyester is not particularly limited. Examples of commercially available brands that can be easily obtained as amorphous polyester include KODAR PTEC and PCTA, which are products of Eastman Kodak Company.

  As described above, the main light scattering layer 1 preferably contains the first light scattering agent and the first light-transmitting resin, and the base material layer 2 has the second light scattering agent and the second light-transmitting property. Although it is preferable to contain a resin, the main light scattering layer 1 and the base material layer 2 may contain additional components other than these as necessary.

  Examples of the additive component include a soft polymer. Examples of the soft polymer include an olefin soft polymer composed of an α-olefin, an isobutylene soft polymer composed of isobutylene, and a diene composed of a conjugated diene such as butadiene and isoprene. Soft polymers, cyclic olefin-based soft polymers composed of cyclic olefins such as norbornene and cyclopentene, organic polysiloxane-based soft polymers, soft polymers composed of α, β-unsaturated acids and their derivatives, unsaturated alcohols and amines or A soft polymer made of the acyl derivative or acetal, a polymer of an epoxy compound, fluorine rubber, or the like can be applied.

  As the additive component, in addition to the above, a plasticizer, an antioxidant, an antistatic agent, a coloring material, a filler, and the like may be used as long as the transparency of the transmission screen is not impaired.

  Materials applicable as the first light scattering agent and the second light scattering agent include inorganic fine particles such as calcium carbonate, alumina, titanium dioxide, silicon dioxide, and glass beads, styrene crosslinked beads, MS crosslinked beads, and siloxane based crosslinking. Examples thereof include organic fine particles such as beads. In addition, hollow cross-linked fine particles made of highly transparent resin materials such as methacrylic resin, polycarbonate resin, MS resin, and cyclic olefin resin, hollow fine particles made of glass, and the like are also applicable as the light scattering agent. The light scattering agent is preferably dispersed in the resin constituting the main light scattering layer 1 and the base material layer 2.

  As a light scattering agent for the main light scattering layer, which is important for forming an image, transparent fine particles improve the color reproducibility of the entire projected image rather than white fine particles such as titanium dioxide. preferable. Examples of the transparent fine particles include inorganic fine particles such as alumina, silicon dioxide, and glass beads, and organic fine particles such as styrene crosslinked beads, MS crosslinked beads, and siloxane crosslinked beads.

  Moreover, the shape of the first light scattering agent and the second light scattering agent is not particularly limited, and for example, a light scattering agent such as a true spherical shape, a spherical shape, a cubic shape, a hexagonal shape, or an indefinite shape can be applied. It is. Furthermore, the particle size of the light scattering agent is preferably in the range of 0.02 μm to 10 μm, and more preferably in the range of 0.1 μm to 2 μm.

  As described above, the concentration of the second light scattering agent in the base material layer 2 is lower than the concentration of the first light scattering agent in the main light scattering layer 1. The minimum value of the concentration of the second light scattering agent in the base material layer 2 is 0. However, since the luminance uniformity of the image can be increased, the concentration of the second light scattering agent in the base material layer 2 is 0. Is preferably exceeded.

  The concentration of the light scattering agent is the weight fraction (ppm) of the first light scattering agent based on the total mass of the main light scattering layer 1 or the second light scattering agent based on the total mass of the base material layer 2. It can be expressed in weight fraction (ppm).

  The concentration of the first light scattering agent in the main light scattering layer 1 is preferably 10 to 3000 ppm, more preferably 100 to 2500 ppm, and still more preferably 500 to 2000 ppm. On the other hand, the concentration of the second light scattering agent in the base material layer 2 is preferably 0.1 to 4.5 ppm, more preferably 0.3 to 4 ppm, and further preferably 0.5 to 3 ppm.

The ratio (C ₁ / C ₂ ) of the concentration (C ₁ ) of the first light scattering agent 1 in the main light scattering layer 1 to the concentration (C ₂ ) of the second light scattering agent in the substrate layer 2 is It is preferably 20/1 to 2000/1, and more preferably 100/1 to 1000/1. As described above, the addition of the light scattering agent to the base material layer as well as the main light scattering layer has a preferable effect of improving the luminance uniformity of the image.

Moreover, it is preferable that the main light-scattering layer 1 and the base material layer 2 are specific thickness ratios. Specifically, the ratio (T ₁ / T ₂ ) of the thickness (T ₁ ) of the main light scattering layer 1 to the thickness (T ₂ ) of the base material layer 2 is 1/300 to 1/7. Preferably, it is 1/200 to 1/15, more preferably 1/100 to 1/25.

  Furthermore, the thickness of the main light scattering layer 1 varies depending on the type of the first light scattering agent, but is preferably in the range of 20 μm to 500 μm. When the thickness of the main light scattering layer 1 is 20 μm or more, the imaging performance is excellent, and when it is 500 μm or less, the light transmittance is high and the background visibility is improved.

  The main light scattering layer 1 and the base material layer 2 each contain components constituting the main light scattering layer 1 (preferably containing a first light scattering agent and a first light transmitting resin, and containing other additive components) And a component constituting the base material layer 2 (preferably containing a second light scattering agent and a second light-transmitting resin, and may contain other additive components). It can obtain by forming in a shape. As the thermoplastic resin sheet, any of an extruded sheet produced by extrusion molding and a cast sheet produced by a casting method can be applied.

  In the transmission type screen of the present invention, the light transmittance in the stacking direction of the laminate comprising the main light scattering layer 1 and the base material layer 2 is 70% or more, and the contrast is 600: 1 or more.

  Here, the light transmittance means the total light transmittance measured according to JIS K7361, and the light transmittance is preferably 70% or more, and more preferably 80% or more. By setting the light transmittance to 70% or more, the projector side can visually recognize the background of the screen without displaying the image on the screen, and the opposite side of the projector displays a clear image with high contrast on the screen. Will be able to.

  Contrast is obtained by forming a white image and a black image with a projector from the back of the transmissive screen, measuring each brightness with a luminance meter from the front, And luminance min. Is a value obtained by measuring. The contrast is the brightness max. : Luminance min. Can be expressed as brightness max. / Luminance min. It can also be expressed as The contrast of 600: 1 or more means that the contrast ratio (luminance max / luminance min) is 600 or more. When the contrast is 600: 1 or more, the sharpness of the image is sufficiently high and the performance as a transmission screen is enhanced. The contrast is preferably 600: 1 or more, and more preferably 700: 1 or more.

  The transmissive screen of the present invention is not limited to the form of the transmissive screen 10 according to the first embodiment and the transmissive screen 11 according to the second embodiment, and various modifications are possible. For example, another layer may be provided between the main light scattering layer 1 and the base material layer 2 of the transmissive screen 10 or 11 as long as the above light transmittance and contrast are maintained. Examples of such a layer include a coupling agent layer that improves the adhesion between the main light scattering layer 1 and the base material layer 2. Further, an antistatic agent layer or a surface protective layer may be provided on the outermost surface of the transmission screen.

  Next, a method for manufacturing a transmission screen will be described.

  As described above, the base layer and the main light scattering layer of the transmissive screen are the first light transmissive resin or the second light transmissive resin (hereinafter collectively referred to as “light transmissive resin”). ), The first light-scattering agent or the second light-scattering agent (hereinafter collectively referred to simply as “light-scattering agent”) is dispersed, and the obtained light-transmitting resin composition is extruded or It can be obtained by forming it into a sheet by a casting method. The method for producing the light transmissive resin composition is not particularly limited as long as the light scattering agent fine particles are uniformly dispersed in the light transmissive resin, but a preferable method will be described later.

  When manufacturing a light-transmitting resin composition containing light-transmitting resin and light-scattering agent fine particles as a base layer and a main light-scattering layer of a transmission screen, the light-scattering agent particles are uniformly in the light-transmitting resin. As a dispersion method, for example, the following method (1) or (2) can be applied.

(1) A method of melt-kneading a transparent thermoplastic resin to be a base material layer and a main light scattering layer and fine particles of a light scattering agent with an extruder:
In this case, the light scattering agent dispersion is prepared by dispersing the light scattering agent fine particles in an organic liquid, preferably using an ultrasonic generator. The prepared light scattering agent dispersion and light transmissive resin are mixed, and the mixture is melt-kneaded with an extruder. At that time, the organic liquid to be used is not limited as long as the fine particles of the light scattering agent are not dissolved and swelled and are uniformly dispersed. Depending on the dispersion state, several kinds of organic liquids can be mixed and used at an arbitrary ratio.

  The organic liquid referred to here includes not only general organic liquids but also polymerizable monomers that constitute light-transmitting resins, so that the light scattering agent particles hardly dissolve, swell, etc., and are uniform. If it disperses | distributes, it will not specifically limit. Moreover, you may mix and use several types of organic liquids in arbitrary ratios by the dispersion state of the fine particle of a light-scattering agent.

  As the general organic liquid, ketones such as acetone and methyl ethyl ketone, aromatics such as xylene and toluene, and alcohols such as methanol and ethanol can be applied. As the polymerizable monomer, for example, when the light-transmitting resin is a methacrylic resin, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, 2-ethylhexyl methacrylate Methacrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, acrylic acid esters such as 2-ethylhexyl acrylate, unsaturated acids such as methacrylic acid and acrylic acid, etc. Is applicable.

  The mixing ratio of the light scattering agent fine particles and the organic liquid can be arbitrarily determined in consideration of the dispersibility of the light scattering agent fine particles. It is preferable to mix in the range of 0.001 to 80 parts by weight.

  Also, the mixing ratio of the light scattering agent dispersion composed of the light scattering agent fine particles and the organic liquid and the light transmitting resin can be arbitrarily determined in consideration of the handling property in the mixing extrusion process. The dispersion is preferably mixed in the range of 0.001 to 10 parts by weight with respect to 100 parts by weight of the permeable resin.

  The method for mixing the light scattering agent dispersion into the light-transmitting resin is not particularly limited, and for example, the light scattering agent dispersion can be mixed by a mixing method such as mixing with a Henschel mixer, mixing with a super floater, or mixing with a tumbler.

  Also, the extruder used for melt kneading the above mixture does not necessarily need to be a unique one, and any ordinary single-screw or twin-screw extruder may be used. However, from the viewpoint of removing the volatile components of the organic liquid used for dispersion, an extruder capable of devolatilization under reduced pressure of preferably 300 Torr or less is preferable at the vent port. Further, as the die, it is preferable to use a multilayer die capable of controlling the thickness of each layer.

  From the viewpoint of preventing secondary aggregation of the light scattering agent fine particles, it is preferable in production to use a twin screw extruder. The temperature of the extruder can be arbitrarily set depending on the type of light transmissive resin to be used. For example, when a methacrylic resin is used as the light transmissive resin, the temperature is around 180 ° C to 260 ° C.

(2) A method of obtaining a screen by polymerization by a casting method:
In this case, a method of dispersing the fine particles of the light scattering agent in the raw material monomer of the light-transmitting resin or the monomer copolymerizable with this monomer, preferably using an ultrasonic generator Is applicable. In this case, the light scattering agent particles are preferably dispersed in advance in a part of the raw material monomer, and then mixed with a partially polymerized polymer solution or the like. The amount ratio between the light scattering agent fine particles and the raw material monomer in which the light scattering agent is dispersed can be arbitrarily determined from the dispersibility, the viscosity at the time of preparation, the handling property, and the like.

  Further, the polymerization conditions such as the polymerization temperature, polymerization time, polymerization initiator amount and the like in the casting method and the method for forming the sheet (cast plate) are not particularly limited. As a method for forming the sheet, for example, a glass cell casting method, a continuous casting method, or the like can be applied.

  The surface of the transmissive screen obtained by the production method (1) or (2) has a specular gloss because the light scattering agent concentration is low, and is preferable for obtaining a high contrast.

  In addition, the ultrasonic generator used for dispersion | distribution of microparticles | fine-particles is not specifically limited, A commercially available ultrasonic cleaner, an ultrasonic stirrer, etc. can be used. For example, an ultrasonic cleaner having an ultrasonic frequency of 28 kHz to 100 kHz is generally used. The irradiation time by the ultrasonic generator can be arbitrarily set depending on the dispersion state of the light scattering agent fine particles, but it is generally preferable to irradiate for about 1 to 60 minutes.

  Hereinafter, the embodiments of the present invention will be specifically described based on examples, but the present invention is not limited to these examples. The results obtained in each example are shown in Table 1.

[Example 1]
Delpet LP-1 (methacrylic resin: manufactured by Asahi Kasei Chemicals Co., Ltd.) was blended with 2.5 ppm of alumina having an average particle size of 0.5 μm as a light scattering agent to prepare a base layer resin. Further, a resin for main light scattering layer prepared by blending 1000 ppm of the alumina with Delpet LP-1 was prepared. The base layer resin is loaded into an extruder having a screw diameter of 120 mmφ and L / D (extruded length / extruded diameter) = 32, and the main light scattering layer resin is further used as an extruder having a screw diameter of 40 mmφ and L / D = 32. Using these extruders, a laminated sheet having a thickness of 8 mm, a width of 1120 mm, and a length of 2300 mm was extruded to obtain a screen. The thickness of the coating layer of the screen was 200 μm, and the light transmittance was 90%.

  Here, as a method for measuring the average particle diameter of the light scattering agent, the light scattering agent fine particles are dispersed in an organic liquid by ultrasonic waves, and the obtained dispersion is measured using a microtrack method, and is 50%. The cumulative particle size was taken as the average particle size.

  The laminated sheet is set up as a screen, and a “white” image and a “black” image are formed on the sheet with a projector from the back, and each brightness is measured with a luminance meter from the front. / Luminance min. The contrast.

  In addition, "NTSC Test Signal Generator 435" (manufactured by Leader Electronics Corporation) was used as a "white" and "black" generator, and was projected on a screen with "Intelligent Projector iP-55" (manufactured by Avionics, Japan). . As the luminance meter, BM-7 (manufactured by Topcon Corporation) was used.

  As a result, the contrast (luminance max./luminance min.) Was 910: 1, which was a high contrast that was not found in the past.

[Example 2]
A multilayer sheet was extruded in the same manner as in Example 1 except that the amount of the light scattering agent in the base material layer was 0.5 ppm, and a screen having a light transmittance of 91% was obtained. The contrast of this screen was 800: 1, which was as high as in Example 1.

[Example 3]
A multilayer sheet was extruded in the same manner as in Example 1 except that the amount of the light scattering agent in the base material layer was 4.5 ppm, and a screen having a light transmittance of 86% was obtained. The contrast of this screen was 620: 1, which was inferior to that of Example 1, but higher than that of the existing transmission type screen (Comparative Example 2).

[Example 4]
A multilayer sheet was extruded in the same manner as in Example 2 except that the light scattering agent for the base material layer was changed to titanium dioxide having an average particle size of 0.3 μm to obtain a screen having a light transmittance of 89%. The contrast of this screen was 780: 1, which was as high as in Example 1.

[Example 5]
A multilayer sheet was extruded in the same manner as in Example 1 except that the average particle diameter of alumina was 1 μm, and a screen having a light transmittance of 88% was obtained. The contrast of this screen was 820: 1, which was as high as in Example 1.

[Example 6]
A multilayer sheet was extruded in the same manner as in Example 4 except that the light scattering agent concentration of the base material layer was set to 0.1 ppm to obtain a screen having a light transmittance of 91%. The contrast of this screen was 650: 1, indicating a high contrast.

[Comparative Example 1]
A multilayer sheet was extruded in the same manner as in Example 1 except that the amount of the light scattering agent in the base material layer was changed to 5 ppm to obtain a screen having a light transmittance of 84%. The contrast of this screen was 570: 1, which was inferior to the example.

[Comparative Example 2]
A multilayer sheet was extruded in the same manner as in Example 1 except that no light scattering agent was added to the base material layer to obtain a screen having a light transmittance of 91%. The contrast of this screen was 400: 1, which was inferior to the examples.

[Comparative Example 3]
In this comparative example, a highly transparent screen “Dilad Screen T40Si” (manufactured by Kimoto Co., Ltd.) was bonded to one side of a transparent methacrylic resin plate (8 mm thick) to obtain a screen having a light transmittance of 73%. The contrast of this screen was 420: 1.

  The image projected on the transmission screen of the present invention is clear, and it is excellent in background visibility as well as being used as a general screen. Therefore, advertisement, promotion and guidance means in a show window, public facilities, company lobby, etc. Can be suitably used.

  In addition, since all processing methods applicable to the base resin used are possible, for example, it is possible to project an image on a processed dome shape, and as a screen with an unprecedented design. It can be used suitably.

Claims (6)

A main light scattering layer containing a first light scattering agent, and a base material layer formed on the main light scattering layer and containing a second light scattering agent having a concentration lower than the concentration of the first light scattering agent A transmissive screen comprising a laminate comprising:
The light transmittance of the laminate direction of the laminate is 70% contrast is 600: Ri 1 or der,
The concentration of the first light scattering agent in the main light scattering layer is 10 to 3000 ppm, and the concentration of the second light scattering agent in the base material layer is 0.1 to 4.5 ppm. Mold screen. The rear projection screen according to claim 1, wherein the main light-scattering layer is a component of the first light-transmissive resin, the base layer is to be a constituent component of the second light transmitting resin. The transmissive screen according to claim 2, wherein the first light transmissive resin and / or the second light transmissive resin is a methacrylic resin. The ratio (C ₁ / C ₂ ) of the concentration (C ₁ ) of the first light scattering agent in the main light scattering layer to the concentration (C ₂ ) of the second light scattering agent in the substrate layer. It is 20 / 1-2000 / 1, The transmission type screen as described in any one of Claims 1-3 . Any ratio _(T 1 / _{T 2)} the claims 1-4 is 1 / 300-1 / 7 of the thickness of the base layer thickness of the main light-scattering layer to the _{(T 2) (T 1)} A transmissive screen according to claim 1. The transmission according to any one of claims 1 to 5 , wherein the main light scattering layer has a film shape, and the base material layer is formed on one or both of the main surfaces of the main light scattering layer. Mold screen.

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