KR20080080862A - Transmission-switching screen - Google Patents

Abstract

A transmission-variable screen is provided to implement a holographic projection screen and a rear projection screen according to the transparency changed by thermal energy. A transmission-variable screen comprises a variable medium(40) capable of changing the transmissivity, a pair of substrates(10,20) forming a cell by surrounding the variable medium, and a sealing units(30) sealing a pair of transparent substrates. The variable medium obtains by light-curing a composition, which is made of at least one water-soluble thermo-responsive polymeric material, a light curable hydrophilic monomer, a coupling agent, a photoinitiator, and an anti-shrinking agent.

Description

Transmittance variable screen {TRANSMISSION-SWITCHING SCREEN}

1 shows a partial cross sectional side view of a variable transmissive screen consisting of a sealing medium consisting of a variable media, a pair of substrates and a spacer or sealant of the present invention.

Figure 2 shows a part of a side cross-sectional view of a variable transmissivity screen consisting of the variable media of the present invention, a pair of substrates, heating means and sealing means consisting of spacers or sealants.

3 is a view showing a part of a side cross-sectional view of a bonded variable screen consisting of a variable medium of the present invention, a transparent substrate having a protruding transparent pattern, a smooth transparent substrate, and a sealing means composed of a spacer and a sealant.

Figure 4 shows a part of a side cross-sectional view of a variable transmittance screen comprising a plurality of bubble-formed variable media, a pair of substrates and sealing means consisting of spacers or sealants.

5 is a view showing a part of a side cross-sectional view of a bonded variable screen comprising a variable medium of the present invention, a transparent substrate having a concave transparent pattern, a smooth transparent substrate, and a sealing means composed of a spacer and a sealant.

<Explanation of symbols for the main parts of the drawings>

10: transparent substrate 1 20: transparent substrate 2

30: sealing means 40: variable media

50: pattern (convex and concave) 50a: bubble

20a: protective layer 20b: transparent heating means

140: light emitting means 150: protective reflection cover

FIELD OF THE INVENTION The present invention relates to projection screens, and more particularly to a multi-function, variable transmittance screen that can be used as a holographic screen or as a rear projection screen (bidirectional projection screen).

Existing front projection screens are designed to view the projected image from the front of the screen. Usually, substrates such as white cloth, film, and acrylic are used, and the surface of the substrate is processed in various ways to improve the properties of the screen. As a processing method, the surface of the substrate may be finely scratched, or fine particles such as glass beads may be coated or aluminum coated. The rear projection screen is designed to transmit an image projected behind the screen to the viewing space. Simple rear-projection screens process the surface of transparent film or transparent acrylic in many ways, such as by coating microparticles such as glass beads, as in front projection screens, or by numerous micro-optical lenses, such as fresnels and lenticulars. Improve the characteristics of the screen by forming a lens. Holographic screens are generally designed in a suitable manner, such as to form relief holograms on the surface of the permeable substrate, or to form volume holograms such as photopolymers, dichromate gelatin, silver halides, etc. within the permeable substrate.

Since the conventional front projection screen or rear projection screen is always an opaque white substrate, the application range is very limited. For example, when installed on the show window or glass window side of the store, it will be difficult to apply because it interferes with the internal and external view. In addition, optical lenticular screens, such as fresnel and lenticular lenticular screens, which perform best as rear projection screens, require complex manufacturing processes and require fine printing, extrusion and coating techniques. . The holographic screen has the advantage of realizing the image without disturbing the inside and outside view, but there is no function to block the view when desired, and the price is very expensive due to the difficulty of the manufacturing process.

Therefore, the present invention uses a relatively low cost raw material, simple structure and simple manufacturing equipment, laminated glass structure, while maintaining the transparent state in normal, freely converting light transmittance can be used as a holographic projection screen or rear projection screen It is an object to provide a variable rate screen.

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 is an embodiment of a transmission-switching screen of the present invention, as shown in the middle of the variable switching medium 40 (switching medium) a pair of substrate that is visible at least one portion transparent (10 and 20) enclosed with a pair of substrates, and with sealing means 30 employing spacers and / or sealants to space and seal the substrates 10 and 20. It shows the side of a variable screen filled and sealed in a cell. The spacing between the pair of substrates 10 and 20 filled with the variable media 40 of the present invention is not particularly limited, and may be approximately 0.1 to 10 mm, but a thickness of about 0.1 to 3 mm is preferable. . The substrates 10 and 20 used in the present invention may be glass or plastic, but should be transparent, and the substrate on one side may be a multilayer of one or more layers. That is, using a plurality of substrates overlapping, or the non-glare coating, anti-reflection coating, anti-static coating (anti-reflection coating) on the outer surface of the substrate constituting the cell of the variable screen functional coatings such as static coatings and selective absorption coatings that selectively absorb specific wavelengths. Types of glass that can be used include, but are not limited to, general transparent glass, translucent glass, etched glass, colored glass, tempered glass, laminated glass, wired glass, heat absorbing glass, heat reflecting glass, UV absorbing glass, metal coating glass, Plastic is not only transparent acrylic resin and polycarbonate, but also PET film, heat shield film, UV protection film, metal coated film or Saran film. Special films such as film made by Dow Product and Aclar film made by Allied Product can be used without limitation.

2 is a cross-sectional view of a variable screen according to an embodiment of the present invention. The difference from the embodiment of FIG. 1 is that a protective layer protects the transparent heat generating layer 20b and the transparent heat generating layer 20b on one transparent substrate. 20a is further provided. The transparent heat generating layer 20b has a low-e coating, an indium tin oxide coating, a fluorine-doped tin coating, a gold coating, a silver coating, and a silver coating. There is no restriction on the coating of transparent electrically conductive materials such as copper coating, and when the AC or DC electricity is applied to the transparent conductive coating layer, heat is generated. The protective layer 20a protecting the transparent heat generating layer 20b may be selectively deleted.

Sealing means (30) using spacers and / or sealants used in the present invention serve to block the external environment while allowing the variable media to maintain a constant thickness between the substrates. The spacer is a double-sided tape of a certain thickness, the sealant is polyvinyl butyral, epoxy resin, acrylic resin, isobutylene (polyvinyl butyral) used in the manufacture of ordinary multilayer glass or laminated glass isobutylene, silicon, polysulfide, or the like may be used, or frit, which is a low temperature molten glass paste, may be used. Such a sealant has a kind having different characteristics such as moisture curability, heat curability, and photocurability, and may be selected and used according to the needs of the manufacturing process of the bonded variable screen of the present invention. The transparent heat generating layer 20b forms a bus bar with silver at both ends of the coating layer so that electricity can flow evenly through the transparent electrically conductive coating layer, and then connect lead wires. Supplying direct current (DC current) or alternating current (AC current), forming a pattern of constant width and length of conductive silver or conductive carbon on the inner or outer surface of the substrates 10 and 20 to connect the conductors Various methods are selected, such as supplying a film or bonding a sheet formed with a pattern of conductive silver or conductive carbon that can generate heat on a separate film, that is, PET film, to the outside of the substrates 10 and 20 using an adhesive. Use it. As a general example of generating heat by forming a pattern from conductive silver or conductive carbon or fine tungsten wire, a pattern formation method of anti-fog hot wire of an automobile rear window, a windshield, or a side mirror may be applied. The present invention is based on the basic structure of Figures 1 and 2, it is possible to have a variable screen having a variety of different structures according to the application field or needs.

The switchable medium 40 includes at least one water-soluble thermo-responsive polymeric material selected, at least one light curable hydrophilic monomer selected, and a coupling agent. A light curable composition of a composition comprising an agent, a solvent, a photoinitiator and an anti-shrinking agent. The medium is transparent at room temperature and then absorbs external energy, that is, thermal energy. When received, the light transmittance is changed. The solvent used in the variable medium is selected from pure water, organic solvent, or a mixture thereof. The solvent is suitably 30 to 49% by weight based on the total weight of the variable medium. When 30% or less is used, the thermal sensitivity of the water-soluble thermally sensitive polymer is lowered. When 49% or more is used, the hydrophilic monomers have an effect on the dispersibility of water, thereby decreasing transparency, and the variable medium exhibits a thin gel property. When manufacturing a large-area variable screen vertically, the hydraulic pressure increases at the lower part, resulting in stress, and the thickness of the upper and lower parts is changed, and the adhesion between the variable medium and the substrate is lowered, so that the variable medium is separated from the substrate. The gel properties are strong. That is, since the substrate does not provide uniform and sufficient adhesive force to the variable medium, the lower part becomes thicker than the upper part, or peeling occurs, thus losing the value as a product, and thus it will not be possible to have a laminated glass structure which is one of the characteristics of the present invention. . The water-soluble thermosensitive polymer materials useful in the present invention should be dissolved in water to be a transparent solution, and any polymer material having a critical solution temperature (CST) that changes in transparency due to heat sensitivity and becomes precipitated or gel at a constant temperature. Can be used Specific examples of such water soluble thermosensitive polymers include polyN-vinyl caprolactam, poly N-isopropyl acrylamide and polymethylvinyl ether. The water soluble thermosensitive polymer material may be used in an amount of 5 to 30 wt% based on the total weight of the variable medium. When less than 5% by weight is used, the thermal sensitivity, that is, the change in transmittance is insufficient, and when more than 30% is used, the phase separation phenomenon is promoted, resulting in an inhomogeneous medium and cannot be used. The transparent aqueous solution of these water-soluble thermally sensitive polymer materials coagulates and precipitates as the temperature rises to change into an opaque state, and finally, phase separation occurs into two layers, a transparent upper layer and an opaque lower layer. This precipitation is known to be due to an increase in temperature or to interference with the hydration of an aqueous solution of thermally sensitive material by certain ions. However, phase-separated solutions are not practical to be used alone in variable screens requiring relatively stable and reversible media.

Thus, the inventors find a solution to overcome this phase separation phenomenon. In order to achieve a relatively stable and reversible variable medium, at least one water-soluble thermally sensitive polymer material is uniformly mixed with at least one photocurable hydrophilic monomer and a coupling agent, a solvent, a photoinitiator and an antishrinkant to cause a polymerization reaction. By irradiating ultraviolet rays or electron beams, a polymer material, that is, a variable medium, exhibiting properties that are completely different from those of the original thermosensitive polymer material, that is, a phase separation phenomenon does not occur while exhibiting a changed critical solution temperature. If only thermosensitive polymers, hydrophilic monomers, solvents, and photoinitiators are used without coupling agents or shrinkage inhibitors, the unreacted monomers remain in the media, even if cured by UV and electron beams. Deterioration proceeds relatively quickly, causing peeling due to weak adhesion to the substrate, shortening the life of the media, and eventually losing its value as a product due to uneven heat-sensitive characteristics or phase separation. . The photocurable hydrophilic monomer used in the variable media is preferably hydrophilic because it must be easily dispersed in water and maintained in a transparent state so as not to affect the transparent aqueous solution of the water-soluble thermosensitive polymer material. Is advantageous. In addition, the monomer is preferably monofunctional rather than polyfunctional, and when polyfunctional, i.e., bifunctional or more monomers are used, excessive shrinkage or partial shrinkage occurs when the photocuring reaction proceeds. It adversely affects the adhesion of the. That is, the bifunctional monomers are cross-linked with each other when polymerized by the initiator, thereby increasing the volume reduction rate, which becomes smaller than the volume of the original mixed composition, thereby increasing the substrates 10 and 20 and the spacer of the variable screen. And / or the medium in the cell composed of the sealing means 30 made of sealant has a high polymer shrinkage and shrinkage as a result of the shrinkage stress, so that the medium is separated from the substrate of the cell, resulting in peeling phenomenon. It is preferable not to use it as it falls, and you will have to use very small amounts even if you use it. Photocurable hydrophilic monomers can be used in any hydrophilic monomers that are dispersible in water and polymerized by an anionic radical, and specific examples thereof are hydroxyalkyl esters of unsaturated carboxylic acids, that is, acrylic acid. acid), methacrylic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, bishydroxyethyl methacrylate phosphate), hydroxy Hydroxypropyl acrylate, hydroxypropyl methacrylate, acrylamide, 2 (2-ethoxyethoxy) ethyl acrylate 2 (2-ethoxyethoxy) ethyl acrylate, hydroxy Methyl Acrylamide, Dimethyl Acrylamide lamide), and at least one can be selected. The photocurable hydrophilic monomer is suitably 31 to 50% by weight based on the total weight of the variable medium. When used at less than 31% by weight, the adhesion to the substrate is inferior, and when more than 50% by weight is used, the thermally sensitive properties of the water-soluble thermally sensitive polymer are degraded. In other words, when used at less than 31%, the medium exhibits a kind of thin gel property, and when applied vertically to a large-area variable screen, when it is placed vertically, the hydraulic pressure is increased in the lower part than the upper part so that the stress is generated. It is changed and adversely affects the adhesive strength, and the tendency of phase separation phenomenon is increased when the thermal energy is supplied for a long time. That is, since the substrate does not provide uniform and sufficient adhesive force to the variable medium, it cannot have a safety laminated glass structure, which is one of the characteristics of the present invention, and will exhibit unstable variable characteristics. The coupling agent used in the variable media is uniformly dispersed in the variable media and connected to each other in a three-dimensional network structure by hydrolysis reaction and poly / condensation reaction, and also partially fixes the thermosensitive polymer material and the photocurable hydrophilic monomer. At the same time, when the substrate is glass, it is also believed to cause condensation reaction with silanol of the glass to promote adhesion through chemical bonding. It is also believed that the coupling agent affects the thermal sensitivity of the variable media to some extent. Specific examples thereof may use most silane coupling agents, and preferred examples thereof include 3-glycidoxypropyl dimethyl ethoxysilane and 3-glycidoxypropyl methyl diethoxysilane. methyl diethoxysilane, 3-glycidoxypropyl trimethoxysilane, aminoethylaminopropyl trimethoxysilane, 3-methacryloxypropyl trimethoxysilane, etc. Most silane coupling agents can be used without limitation, and at least one can be selected and used. The methoxy or ethoxy functional groups included in the coupling agent also have a function of improving adhesion to the substrate of the variable screen. The concentration of coupling agent is generally about 0.1 to 10% by weight, preferably 0.5 to 7% by weight, based on the total weight of the variable medium. If less than 0.1% by weight does not significantly affect the adhesion, if more than 10% by weight can reduce the transparency of the light control medium or reduce the pot life of the composition (pot life).

Photoinitiators suitable for the present invention can be used any photoinitiator that can form radicals by light and react with photocurable hydrophilic monomers to cause polymerization. Specific examples of such photoinitiators are benzophenone ), Ethyl4- (dimethylamino) benzoate, benzyl dimethyl ketal, 1- (4- (2-hydroxyethoxy) -phenyl) -2-hydroxy 2-methyl-1-propane-1-one (1- (4- (2-hydroxyethoxy) -phenyl) -2-hydroxy-2-methyl-1-propane-1-one), 2-hydroxy-2 -Methyl-1-phenyl-propane- 1-one (2-hydroxy-2-methyl-1-phenyl-propane-1-one), trimethyl benzoyl diphenyl phosphine oxide (2,4,6-Trimethyl benzoyl diphenyl phosphine oxide) and bisacylphosphine oxide. Most photoinitiators can be used to form radicals by light to cause the hydrophilic monomer to cure. It said at least one or more kinds can be used. The concentration of the photoinitiator is generally about 0.1 to 10% by weight, preferably 0.2 to 7% by weight, for each monomer that can be polymerized. In the present invention, a shrinkage inhibiting agent is used. The shrinkage inhibiting agent reduces the volume reduction inevitably generated during the polymerization of the photocuring monomer, thereby suppressing the peeling phenomenon of the light control medium and the substrate due to the volume reduction. Except for the composition constituting the rest is impregnated between the numerous micropores of the shrinkage protector to improve the light transmittance of the shrinkage stabilizer increases the durability of the variable media, and also reduces the tendency of excessive phase separation of the thermosensitive polymer In addition, it plays a positive role in the thermosensitive properties. In addition, due to the chemical bonding caused by the condensation reaction between the silicon and silicon oxide on the surface of the shrinkage preventing agent and silanol produced by the hydrolysis reaction of the coupling agent, the fine particles of the shrinkage preventing agent evenly dispersed in the variable medium are formed in the three-dimensional structure of the coupling agent. The connection is fixed between the connection networks, allowing a more stable variable media. Suitable antishrinkants for the present invention can be used as a supersilicone, ie, aerosil, which is a porous material having a very large surface area to weight and does not significantly reduce transparency. When the variable medium is supplied with heat energy, its transmittance changes, and when the heat energy is removed again to return to its original transmittance, stress is generated by repeating the contraction and expansion of the volume. It reduces the stress that occurs during overexpansion and serves to reduce the tendency of peeling between the variable media and the substrates 10 and 20. Shrinkage inhibitors also increase the diffusivity of light, one of the screen's characteristics. In addition, when using a variable-permeability screen as a decorative window glass, bubbles generated during the addition of a shrinkage inhibitor, that is, due to the porosity of the shrinkage inhibitor, are generated in the early stages of the composition manufacturing, and the generated bubbles are left for a long time or subjected to vacuum defoaming. Although removed and used, the variable screen can be manufactured with bubbles formed to impart a function having a different effect. The concentration of the anti-shrinkage agent of the present invention will be suitably 1 to 200% by volume based on the total volume of the components consisting of thermosensitive polymer material, photocuring monomer, coupling agent, solvent and photoinitiator. The shrinkage inhibitor used in the present invention does not significantly affect the shrinkage preventing property when 1 volume% or less is used, and inconveniences to the manufacturing process due to excessive viscosity increase when 200 volume% or more is used.

In addition to the variable media of the present invention, various additives may be used. Any pigment or dye, which may be uniformly dispersed in water or a monomer, may give a color effect to the variable screen or absorb external light to improve contrast. And antioxidants and / or ultraviolet absorbers may additionally be used to reduce the deterioration of the properties of the monomers, which must be dispersible in water or monomers and the amount added is 0.01 to 5 weights for the variable media. % Will be suitable. In addition, when the variable medium contains water, it may freeze when used at sub-zero temperatures as well as the temperature of the image, and thus an organic solvent may be added. As the organic solvent, at least one selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, 2-butanol, ethylene glycol, and propylene glycol may be used as the alcohol water of the variable medium of the present invention. Can be. Such organic materials not only prevent freezing but also increase or decrease the heat response temperature of the variable medium, thereby improving the dispersibility or stability of some of the variable medium. The amount of organic solvent added varies from 0.01 to 40 for water in the variable medium, depending on the function of focusing on preventing freezing or increasing the response temperature or improving the dispersibility, or depending on the concentration of the variable medium, mutual affinity, and characteristics thereof. Weight percent is suitable, preferably 1-10 weight percent.

The manufacturing process of the variable screen of the present invention can be made as follows. Form a cell with a pair of substrates 10 and 20 and sealing means 30 such as spacers and sealants, and coating one side of the substrate when one of the substrates has a substrate having an electrically conductive coating layer other than the general substrate. In order to generate heat by uniformly flowing electricity to the transparent electrically conductive coating layer, a bus bar is formed at both ends of the coating layer with silver to the transparent heating means 20b having lead wires connected thereto. The variable media composition of the present invention is injected into an empty space of a made cell and then sealed. When the sealed screen is exposed to ultraviolet rays, electron beams, or visible light for a certain time, a polymer reaction of the variable media composition in the cell occurs, and the screen is completely transparent at room temperature but becomes translucent or almost opaque when thermal energy is supplied. The variable medium 40 becomes a variable screen laminated between the substrates. The method of supplying thermal energy naturally changes the transmittance when the summer temperature rises above the reaction temperature of the variable medium, or when the sunlight directly reaches and rises above the reaction temperature of the variable medium, the transmittance changes, or The transmittance may be changed by supplying thermal energy by supplying direct current or alternating current to heat the electrically conductive coating layer or the patterned heating wire. When the image is projected on the transmissive variable screen manufactured by such a process using a projector, a holographic projection screen or a rear projection screen may be implemented according to transparency.

Based on the above manufacturing process of the variable screen, other necessary processes may be added or deleted to manufacture the variable screen according to various other combinations. In other words, the variable screen having the structure as shown in Figs. 1 and 2 is normally transparent and then supplies heat energy to change the transmittance to illuminate the image from the rear to the projector to function as a holographic projection screen or to implement a rear projection screen. It can be a variable screen, and when using a substrate having a transparent electrically conductive coating on one side and a mirror glass substrate on the other side as a base of the variable screen, it is usually used as a mirror and then supplied electricity to the coating surface if necessary. It may be used as a front projection screen by lowering the light transmittance of the variable media by generating heat. Such a variable screen is a non-screen use as shown in Figs. 3 and 5 to make the desired convex pattern 50 or concave pattern 50 transparent on one side of the substrate, and adds an aesthetic surface in general, the transparent pattern is seen. When the transmittance is changed by receiving heat energy, the transparent transmittance variable glass having the transparent or translucent pattern may be used as the window glass of the building, and also on the side of the transmittance variable screens having the structures of FIGS. 1 to 2 and 3 to 5. When light is emitted by attaching light emitting means 140 such as a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED) lamp having a small diameter, a different effect can be obtained, which may give a billboard or an interior decoration, In order to increase the luminous effect, the protective cover 150 may be added. The present invention will be described in more detail with reference to the following examples, and the present invention is not limited to these examples.

Example 1

10.1 g of polyN-vinyl caprolactam as a water-soluble thermosensitive polymer, 23.2 g of hydroxyethyl methacrylate as a photocurable hydrophilic monomer, 2.2 g of 3-glycidoxypropyl trimethoxysilane as a coupling agent, 2- as a photoinitiator 0.75 g of hydroxy-2-methyl-1-phenyl-propane-1-one, 21.2 g of pure water, a composition consisting of aerosil 57 cm3 as a shrinkage agent, spaced between two sheets of 2 mm thick and 10 square centimeter soda ash glass plates It was injected into the inner space made of millimeter cells and sealed. The sealed cell was exposed to a 200W UV fluorescent lamp for about 1 hour to produce a variable screen. In the variable screen, light transmittance began to decrease around 35 ° C to 38 ° C, and when the projector was projected from the rear, a transparent holographic projection image was obtained, and a translucent projection image was realized at about 50 ° C. The variable screen was maintained at about 50 ° C. for 5 hours and then cooled to room temperature 20 ° C., showing no inherent phase separation at all.

Example 2

In the whole composition of Example 1, polymethylvinyl ether was used as the water-soluble thermosensitive polymer material, and the rest was used for the same material and composition ratio. The inside is made of cells of 2 millimeters spacing between the substrate, spacer and sealant connected by wires after dividing the grooves of the lattice pattern to form a concave pattern, and forming a bus bar with silver paste on both ends of the transparent conductive coated glass plate. It was sealed after being injected into the space. The sealed cell was exposed to a 200W UV fluorescent lamp for about 1 hour to produce a variable screen. When heat is generated by applying a constant voltage (220V) to the wires connected to both ends of the variable screen, the light transmittance begins to decrease around 35 ° C to 38 ° C, and a transparent holographic projection image is obtained when the projector is illuminated from the rear. A translucent projection image was implemented at around 50 ° C. The variable screen was maintained at about 50 ° C. for 5 hours and then cooled to room temperature 20 ° C., showing no inherent phase separation at all. In the transparent state, the lattice pattern shines beautifully, while in the translucent state, it is translucent overall, but the lattice pattern shows a different lattice pattern with a lower transmittance, and thus may be useful as decorative window glass. In addition, by attaching cold cathode fluorescent lamps of various colors to the side of the variable screen, the grid pattern with each color could be seen.

The present invention provides light control such as building windows, transport windows, glass doors, greenhouses, office partitions, shower stalls, bath tub enclosures, as well as screens or projection image screens that achieve holographic effects. It can be applied to various applications such as aesthetic interior products.

Claims (12)

As a variable screen, Variable media that can change the transmittance, A pair of substrates surrounding the variable media to form a cell, It consists of a sealing means for sealing a pair of transparent substrate, As a variable medium capable of changing the transmittance, (a) (a-1) at least one water-soluble thermosensitive polymer material selected from polyN-vinyl caprolactam, poly N-isopropyl acrylamide and polymethylvinyl ether, (a-2) photocurable hydrophilic monomers, (a-3) a solvent, (a-4) a coupling agent, (a-5) photoinitiators and (a-6) The variable transmissivity screen which can obtain the composition which consists of shrinkage inhibitors by photocuring. The method of claim 1, The variable medium (a), (a-1) 5-30% by weight of at least one water-soluble thermally sensitive polymer material, based on the total weight of the composition, (a-2) 31 to 50 wt% of the selected at least one photocurable hydrophilic monomer based on the total weight of the composition, (a-3) 30 to 49% by weight of solvent, based on the total weight of the composition, (a-4) 0.1 to 10% by weight of the coupling agent based on the total weight of the composition, (a-5) 0.1 to 10 weight% photoinitiator based on the total weight of monomers and (a-6) A variable transmittance screen which can obtain a composition consisting of 1 to 200% by volume of the shrinkage inhibiting agent based on the total volume of (a-1) to (a-5) by photo curing. The method of claim 1, Variable media (a) that can change the transmittance is a variable transmittance screen further comprises 0.01 to 5% by weight of additives (additives) based on the total weight of the variable medium. The method of claim 1, The substrate (b) is a variable transmittance screen further comprises a transparent heating means on the inner or outer surface of one of the substrate. The method of claim 1, The substrates (b) further comprises at least one of a transparent concave pattern and a transparent convex pattern on the inner or outer surface of the substrate. The method of claim 1, A variable transmittance variable screen further comprising a variable medium having a bubble pattern by photocuring with a plurality of bubbles in the variable medium (a) of the variable screen. The method of claim 1, A variable transmittance screen having light emitting means on at least one side of the variable screen. As a variable screen, (a) variable media capable of varying the transmittance, (b) a pair of substrates surrounding the variable media to form a cell, (c) sealing means for sealing a pair of transparent substrates, As a variable medium capable of changing the transmittance, (a) (a-1) at least one water-soluble thermosensitive polymer material selected from polyN-vinyl caprolactam, poly N-isopropyl acrylamide and polymethylvinyl ether, (a-2) photocurable hydrophilic monomers, (a-3) a solvent, (a-4) a coupling agent, (a-5) photoinitiator, (a-6) The variable transmissivity screen manufacturing method which can obtain the composition which consists of shrinkage inhibitors by photocuring. The method of claim 8, A variable media (a) capable of changing the transmittance is a method for manufacturing a variable transmittance screen further comprises 0.01 to 5% by weight of additives (additives) based on the total weight of the variable medium. The method of claim 8, The substrate (b) is a variable transmittance screen manufacturing method further comprises a transparent heating means on the inner or outer surface of one of the substrate. The method of claim 8, The substrates (b) further comprises at least one of a transparent concave pattern and a transparent convex pattern on the inner or outer surface of the substrate. The method of claim 8, A method of manufacturing a variable transmissivity screen, comprising a variable medium having a bubble pattern by photocuring with a plurality of bubbles in the variable medium (a) of the variable screen.

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