KR101102008B1 - Diffusion film having diffusing and shielding function and Preparing thereof - Google Patents

Abstract

The present invention is a diffusion film having a diffusion and shielding function by extrusion stamping method and a method of manufacturing the same, and more particularly, in the production of a diffusion film, the polymer resin into three layers of the surface layer, the intermediate layer and the back layer on the film Melt extruding; Engraving the extruded film such that the surface layer is provided with a lens shape and roughness, and the back layer is provided with roughness; And it relates to a diffusion film having a diffusion and shielding function and a method for producing the same comprising the step of cooling the stamped film.

Diffusion film, extrusion stamping, shielding function, light diffusing agent

Description

Diffusion film having diffusing and shielding function and Preparing Technical}

The present invention is a diffusion film having a diffusion and shielding function and a method for manufacturing the same, and more particularly, in the diffusion film having a diffusion and shielding function by applying an extrusion stamping manufacturing technology to the light diffusion film for a backlight unit and a method for manufacturing the same. It is about.

Recently, various flat panel display devices have been developed. The flat panel display devices include liquid crystal displays (LCDs), plasma display panels (PDPs), and field emission displays (FEDs). In addition, studies are being actively conducted to improve the display quality of such flat panel displays.

Among them, LCD is a device that injects liquid crystal between two sheets of glass and applies power to the electrodes installed on the upper and lower glass plates to change the arrangement of liquid crystal molecules and display images in each pixel. Such an LCD display device is usually composed of an LCD panel unit, a driver, and a backlight unit. The LCD panel does not emit light by itself and has only a function of transmitting light on the rear surface. Therefore, in the absence of light, that is, at night or indoors, it is a structure that can not display images without the help of backlight. The backlight unit refers to a system for implementing the backlight of such an LCD.

The backlight unit is largely composed of a lamp, sheets, a mechanism part, and a driving circuit. Since the lamp alone cannot produce uniform light over the entire area, the light guide plate, diffuser plate, reflector plate, prism, frame, etc., sheets and mechanisms are provided.

There are various methods for the backlight unit. Currently, the most widely used method is a cold cathode fluorescent lamp (LFT) having a light guiding panel (LGP) printed with a reflection pattern in the center by side light method. The cold cathode fluorescent lamp is placed on the edge. At this time, the reflective pattern printed on the light guide plate is printed in a structure to reduce the phenomenon that the brightness difference occurs depending on the position of the lamp is located at the edge of the panel. Although the method of printing the reflective pattern on the light guide plate is high in productivity, the light loss caused by the printing pattern material itself is inferior in efficiency, and the larger the LCD, the worse the uniformity of the overall brightness.

Since the light guide plate method does not provide sufficient brightness, a direct method in which a plurality of lamps are arranged at regular intervals under the diffuser plate is used. In this method, several fluorescent lamps are arranged in a row on the rear surface of the diffusion sheet to improve luminance and improve uniformity than the photometric type. In order to display a bright screen, the backlight source must be very bright. This is because the light from the light source goes through several steps before reaching the LCD, and loses its original brightness in the process. In addition, the uniformity of light throughout the screen is lost because of the scattering effect.

One way to overcome this problem is to increase the size of the light source, but this is expensive installation cost, high power consumption, and also has a problem of increasing the weight a lot. Thus, several attempts have been made to improve the light source brightness without loss as much as possible during the transmission process.

In flat panel display devices such as LCDs and projection TVs, a diffuser is an optical element that plays an important role in reaching light from the light source to the viewer's eyes. The diffuser plate uniformly distributes the light from the light source and plays an important role in the direct type than in the case of LCD. Structural metering is a structure where light guided by a light guide can be uniformly distributed throughout the screen, but in the case of a direct type, several light sources are distributed below the screen, so that the point just above the light source and the point between the light source and the light source Because there is a difference in the light intensity, you have to offset it.

The most important optical properties of the optical film used to improve visibility in the backlight unit are light transmittance and haze, which require a total amount of light of 60% or more and 85% or more of light for visible light. In order to satisfy these characteristics, a light diffusion film generally has a surface diffusion method of refraction or dispersion in many directions using surface roughness and a bulk diffusion film method having an inherent light dispersion element.

The surface diffusion type diffusion film uses a rough surface exposed to air to maximize the difference in refractive index between the material of the diffusion film and the surrounding medium as much as possible to spread the incident light at the largest angle. For example, light diffusivity is imparted by forming irregularities on the film surface. There is a light diffusing film in which the unevenness is formed on the surface of the transparent resin made of a polyester resin, a polymethyl methacrylate resin or a polycarbonate resin. However, it is difficult to simultaneously obtain excellent light transmittance and light diffusivity only by imparting irregularities to the surface by embossing or sand blasting. In addition, the temperature in the backlight unit generally rises from 80 ° C to 90 ° C, and when the humidity is high, shape deformation may occur severely, so that a material having excellent optical properties while having high heat resistance and low moisture absorption rate is used.

The bulk diffusion film is a light diffusing agent such as fine particles dispersed within the film, and is usually made of a transparent resin made of a resin such as polymethyl methacrylate, polycarbonate, etc., calcium carbonate, titanium dioxide, glass beads, silica particles, polystyrene There are light diffusing plates in which particles, silicone resin particles, crosslinked polymer particles and the like are dispersed.

Regarding the method of using surface roughness, which is a method of using unevenness in the film, Korean Laid-Open Patent Publication No. 2007-0026524 discloses an optical film, a light-diffusion film, a manufacturing method thereof, and a method of using the same. An optical film containing 80% by weight or more of carbonate was made to have a mean surface roughness of 0.5 µm or more on the surface to impart a diffusion effect. However, in the above technology, there is a problem that the shielding function against the bright line is not good and the viewing angle is narrow.

Due to the problems described above, it is desired to develop a diffusion film having a wide viewing angle while having excellent diffusion and shielding performance.

In order to solve the problems as described above, an object of the present invention is to provide a diffuser film having a bright line shielding ability and a wide viewing angle.

In addition, an object of the present invention is to provide a diffusion film having a diffusion and shielding function and a method of manufacturing the same that can be produced in a desired stamping shape is controlled by the residual stress of the polymer material of the diffusion film.

In addition, an object of the present invention is to provide a diffusion film having a diffusion and shielding function and its manufacturing method by improving the physical properties as an optical film, such as brightness, transparency, cloudiness.

In order to achieve the above object, the present invention is a multi-layered diffusion film consisting of a surface layer, an intermediate layer and a back layer, the lens shape and roughness is given to the surface layer, characterized in that the roughness is given to the back layer. Provided is a diffusion film having a diffusion and shielding function.

In another aspect, the present invention provides a diffusion film having a diffusion and shielding function produced by the diffusion film is extrusion.

In another aspect, the present invention provides a diffusion film having a diffusion and shielding function, characterized in that the roughness applied to the surface layer or the back layer has a Rz value of 4 to 10 µm and a Ra value of 1 to 2 µm.

In another aspect, the present invention provides a diffusion film having a diffusion and shielding function, characterized in that the lens shape is uniformly arranged in the same size in the surface layer.

In another aspect, the present invention provides a diffusion film having a diffusion and shielding function, characterized in that the diameter of the lens layer of the surface layer is 40 to 60㎛.

In another aspect, the present invention provides a diffusion film having a diffusion and shielding function, wherein the intermediate layer comprises 10 to 90% by weight of copolyester and 10 to 90% by weight of polycarbonate as a blend or composition of copolyester and polycarbonate.

In the present invention, the intermediate layer is methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, normal butyl methacrylate, normal butyl methyl methacrylate, acrylic acid, methacrylic acid, hydroxyethyl methacrylate, hydride Monomer selected from oxypropyl methacrylate, hydroxyethyl acrylate, acrylamide, metalolacrylamide, glycidyl methacrylate, ethyl acrylate, isobutyl acrylate, normal butyl acrylate and 2-ethylhexyl acrylate It has a diffusion and shielding function further comprising one or more selected light diffusing particles consisting of beads and silicone-based spherical particles made of a homopolymer, copolymer or terpolymer, polyethylene, polystyrene, polypropylene, acrylic and olefin copolymer Provide a diffusion film.

In another aspect, the present invention provides a method for producing a diffusion film, comprising: melt-extruding a polymer resin into three layers of a surface layer, an intermediate layer, and a back layer on a film; Engraving the extruded film such that the surface layer is provided with a lens shape and roughness, and the back layer is provided with roughness; And it provides a method for producing a diffusion film having a diffusion and shielding function comprising the step of cooling the stamped film.

In another aspect, the present invention provides a method for producing a diffusion film having a diffusion and shielding function of the cooling step is quenching, 4 to 20 ℃ cooling air.

In another aspect, the present invention provides a method for producing a diffusion film having a diffusion and shielding function, characterized in that the lens shape is uniformly arranged in the same size in the surface layer.

In another aspect, the present invention provides a method for producing a diffusion film having a diffusion and shielding function, characterized in that the lens shape is uniformly arranged in the same size in the surface layer.

The present invention also provides a method for producing a diffusion film having a diffusion and shielding function, characterized in that the diameter of the lens layer of the surface layer is 40 to 60㎛.

In another aspect, the present invention provides a method for producing a diffusion film having a diffusion and shielding function wherein the intermediate layer comprises 10 to 90% by weight of copolyester and 10 to 90% by weight of polycarbonate as a blend or composition of copolyester and polycarbonate. do.

In the present invention, the intermediate layer is methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, normal butyl methacrylate, normal butyl methyl methacrylate, acrylic acid, methacrylic acid, hydroxyethyl methacrylate, Selected from hydroxypropyl methacrylate, hydroxyethyl acrylate, acrylamide, metalolacrylamide, glycidyl methacrylate, ethyl acrylate, isobutyl acrylate, normal butyl acrylate and 2-ethylhexyl acrylate Diffusion and shielding functions further comprising one or more selected light-diffusing particles consisting of beads and silicone-based spherical particles made of homopolymers, copolymers or terpolymers of monomers, polyethylene, polystyrene, polypropylene, acrylic and olefin copolymers It provides a method for producing a diffusion film having.

Diffusion film according to the present invention is produced by applying the extrusion stamping manufacturing technology, excellent diffusion and shielding function and has a wide viewing angle effect.

In addition, the diffusion film and the manufacturing method of the diffusion and shielding function according to the present invention can be produced in the desired stamping shape to reduce the defective rate of the product and has a good shape reproducibility effect.

In addition, the diffusion film and its manufacturing method having a diffusion and shielding function according to the present invention has the effect of improving the optical properties as an optical film, such as brightness, transparency, blurring.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, it should be noted that in the drawings, the same components or parts denote the same reference numerals as much as possible. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

As used herein, the term "film" is used to mean a film, sheet, plate, or the like having a predetermined width and thickness.

The term "lens shape" is used to mean lenticular, hemispherical lens shape, and the like.

1 is a cross-sectional view of a diffusion film according to an exemplary embodiment of the present invention, and an optical film may be formed including a surface layer 110, an intermediate layer 120, and a back layer 130.

Figure 2 shows a manufacturing process of the diffusion film according to an embodiment of the present invention.

The present invention is to produce a diffusion film by applying the extrusion engraving manufacturing technology that the film extruded from the T-die 210 through the engraving pattern 231 of the pattern roll 230, the lens shape 111 and roughness 112 ) Can be expressed. In addition, the roughness 131 is provided on the surface of the back layer 130 by the first roller 220.

In the diffusion film, the polymer resin of the surface layer 110 may be polycarbonate-based, and as a non-limiting example, preferably an aromatic polycarbonate, more preferably bisphenol-A [2,2-bis (4-hydroxyphenyl). ) Propane] may be a polycarbonate. A material having a benzoyl group may be added to the polycarbonate to prevent yellowing due to ultraviolet rays. Non-limiting examples of the benzoyl group include benzotriazol, benzoxazinone, and benzotriazole.

In addition, the back layer 130 may be made of the same material as the surface layer 110 to prevent yellowing due to ultraviolet rays generated from the lamp.

In addition, the material of the polymer resin of the intermediate layer 120 may be made of a blend or composition of copolyester and polycarbonate, and may specifically include 10 to 90% by weight of copolyester and 10 to 90% by weight of polycarbonate. . However, the present specification is described as the material, but is not limited thereto.

The material of the intermediate layer 120 may be preferably made of a blend or a composition in a specific ratio of copolyester and polycarbonate, and specific ratios of 10 to 90% by weight of copolyester and 10 to 90% by weight of polycarbonate It may include.

The copolyester may be terephthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid or a mixture thereof as the acid component, and ethylene glycol and 1,4-cyclohexanedimethanol (CHDM) may be used as the glycol component. . Non-limiting examples of suitable copolyesters include poly (1,4-cyclohexylenedimethylene terephthalate) (PCT), poly (1,4-cyclohexylenedimethylene naphthalenedicarboxylate) (PCN), poly (1,4-cyclohexylenedimethylene 1,4-cyclohexanedicarboxylate) (PCC) can be used.

The material has a feature that the process moisture content is relatively low to maintain shape stability even at high humidity.

Meanwhile, the intermediate layer 120 may further include light diffusing particles. Since the light diffusing particles should be compatible with a binder (resin) containing particles, organic particles having a similar refractive index to materials and spherical silicon having a low refractive index The particles were examined and used, and inorganic particles having a refractive index of 1.50-1.80 can be used. Particularly, the particle selection to be used is advantageous for solving the problem such as showing the bright line due to the spherical particles whose refractive index difference is 0.1 to 0.2 from the material to increase the shielding ability, and can maximize the diffusion effect with a relatively small particle amount. It is very advantageous.

The refractive index of the diffusing agent particles used increases the light diffusion effect as the difference between the material and the refractive index is larger, but when the refractive index difference is too large, it is disadvantageous in terms of increasing the brightness, so that the proper refractive index difference is obtained and sometimes similar to the material. It is preferable to use the particle | grains with a big difference.

Non-limiting examples of light diffusing particles that can be used in the present invention include methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, normal butyl methacrylate, normal butyl methyl methacrylate, acrylic acid, methacrylic acid, Hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl acrylate, acrylamide, metalolacrylamide, glycidyl methacrylate, ethyl acrylate, isobutyl acrylate, normal butyl acrylate and 2 Homopolymers, copolymers or terpolymers of monomers selected from ethylhexyl acrylates, beads made from copolymers of polyethylene, polystyrene, polypropylene, acrylics and olefins, and silicone-based spherical particles can be used. Preferably, the material is spherical particles between 1 micron and 10 microns having a refractive index difference of about 0.1 to about 0.2. Spherical organic particles having such a difference in refractive index can be easily dispersed in the resin because they have densities similar to those of the material used in the present invention (about 1.10 to 1.30 g / cm 3).

The light diffusing particles used in the present invention may use different ones in type and / or size. For example, light diffusion efficiency can be enhanced by mixing two or more kinds of particles having a difference in refractive index rather than a single type. In addition, light diffusing efficiency may be increased by using particles having similar refractive indices and different sizes, and by applying porous particles, the brightness may be increased while maximizing light diffusing efficiency after assembling the backlight unit.

Using particles of uniform particle size requires a large amount of particles to produce a predetermined light diffusing effect, which results in not only economic inefficiency, but also lowering the overall light transmittance. According to one embodiment of the present invention, the size of the light diffusing particles can be used to increase the light diffusion effect while reducing the particle content by using two kinds of particles of size 20 to 30 microns and 1 to 15 microns.

The light diffusing particles may be used at 0.5 to 30% by weight, preferably 1 to 15% by weight, based on the total weight of the interlayer resin. When the light-diffusing particles are 0.5% by weight or less, a predetermined light-diffusion effect cannot be obtained. When the light-diffusing particles are more than 30% by weight, the light transmittance is lowered, the dispersibility of the particles is lowered, and uniform particle dispersion cannot be obtained.

The material of the intermediate layer 120 is a polycarbonate and copolyester is made of a blend or composition as described above has a property that the glass transition temperature is lower than the surface layer 110 made of a polycarbonate, the intermediate layer 120 Since the glass transition temperature of the c) is lower than that of the surface layer 110, the dimensional stability is improved.

On the other hand, the diffusion film according to the present invention is provided with a multi-layer diffusion film of the melt extrusion stamping method, in the manufacturing process diagram of Figure 2 T-die 210 in the surface layer 110, the intermediate layer 120 and the back layer ( The film with three layers each of 130) is extruded. In the pattern roll 230, the relief pattern 231 has a shape capable of imparting a roughness 112 between the lens shape 111 and the lens shape to the surface layer 110. Also, the engraving pattern 221 of the first roller 220 is provided with a drawing shape so that the roughness 131 can be applied to the back surface layer 130 when the drawing is performed.

Improving the light scattering effect by providing the illumination 112 between the lenses of the surface layer 110, and has a feature that can provide a shielding effect through the light scattering effect by applying the illumination (131) of the back layer 130. The roughness 112 and 131 may be imparted so that the Rz value is 4 to 10 μm and the Ra value is 1 to 2 μm. The shielding function is effectively generated within the above range, and there is an effect of reducing defects due to stains, etc., generated during processing, and reducing scratches during processing and moving means.

The film having the three layers is extruded and passed between the first roller 220 and the pattern roll 230, so that the lens layer 111 is formed on the surface layer 110 through the relief pattern 231 of the pattern roll 230. And roughness 112 is applied to the surface of the back layer 130 through the relief pattern 221 of the first roller 220.

Thereafter, the diffusion film is cooled between the pattern roll 230 and the second roller, and is cooled between the pattern roll 230 and the second roller 240 (region B) (see FIG. 2). To this end, by forming a quenching condition in the B region to drastically lower the surface temperature of the film, by limiting the fluidity of the polymer chain due to the residual stress of the polymer chain as the film is cured to minimize the possibility of shape change .

Specifically, the surface of the embossed shape may be further provided with a cooling means such as an air knife to fix the shape expressed on the film. At this time, the cooling temperature is preferably 4 to 20 ℃, more preferably 4 to 10 ℃.

Figure 3 is a schematic perspective view of the diffusion film produced by the preferred embodiment of the present invention, the lens shape 111 of the surface layer 110 may be arranged uniformly in close contact with a plurality of lenses of the same size. In addition, Figure 4 shows the position of the lens shape in the diffusion film produced according to an embodiment of the present invention, the lens shape is arranged uniformly while forming an angle of 60 ° in the form of an equilateral triangle when connecting the origin of the round shape do.

On the other hand, the diameter of the lens shape 111 of the surface layer 110 is preferably 40 to 60㎛. Although the light condensing effect is excellent within the above range, when the diameter exceeds 60 μm, moiré phenomenon occurs, and the lens shape 111 of less than 40 μm has a small diameter, resulting in processing limitations.

Hereinafter, embodiments of the present invention will be described in detail.

Example 1

A polycarbonate resin containing bisphenol-A [2,2-bis (4-hydroxyphenyl) propane] was used as the resin for the surface layer and the back layer, and a benzoyl group material was added. As the resin of the intermediate layer, a polycarbonate-based resin containing a polyester-based resin mainly containing 1,4-cyclohexanedicarboxylic acid and bisphenol-A [2,2-bis (4-hydroxyphenyl) propane] It was mix | blended in the ratio of 1: 1, and it mixed and mixed methylmethacrylate as 15 weight% of the weight of resin of an intermediate | middle layer as a light-diffusion agent. Subsequently, the resin was manufactured by screw coextrusion at 270 ° C., and the lens shape was the same size, the diameter was 40 μm, the height of the lens shape was 18 μm, and the roughness of the surface layer and the back layer was Rz value. The diffusion film was manufactured by operating the pattern roll and the first roller so that the 6 mu m and the average Ra value were 1.0 mu m.

Examples 2 and 3

The same process as in Example 1, except that the diameter of the lens shape was 50㎛, 60㎛, respectively, and the pattern roll was operated so that the height is 23㎛, 28㎛, respectively, to prepare a diffusion film.

Example 4

The same process as in Example 1, except that the roughness of the surface layer and the back layer was a diffusion film was prepared by operating the pattern roll and the first roller so that the Rz value is 10㎛, the average Ra value is 2.0㎛.

Examples 5 and 6

The same process as in Example 4, except that the diameter of the lens shape is 50㎛, 60㎛, respectively, the pattern roll was operated so that the height is 23㎛, 28㎛, respectively, to prepare a diffusion film.

Comparative Examples 1 to 3

In the same manner as in Examples 1 to 3, a diffusion film was prepared without imparting roughness to the diffusion film surface layer and the back layer.

* Test Methods

1. Transmittance (TT) and haze (Haze): Measured by ASTM D1003 method using NIPPON DENSHOKU 300A analyzer.

2. Luminance: Measure the film on the stage equipped with TOPCON BM-7 under the conditions of 16.5V and Dimming value of 2.8V with CCFL voltage mounted on backlight unit (diffusion plate-diffusion film-prism-diffusion film). .

Table 1 shows the results of testing optical characteristics such as transmittance for each of Examples and Comparative Examples.

division Transmittance (%) Haze (%) Brightness (cd / m 2) Example 1 65 92 9630 Example 2 68 94 9660 Example 3 67 94 9710 Example 4 66 92 9650 Example 5 69 91 9460 Example 6 65.5 92.5 9340 Comparative Example 1 58 88 8880 Comparative Example 2 57 90 8650 Comparative Example 3 58 89 8630

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. It will be clear to those who have knowledge of.

Figure 1 shows a cross-sectional view of the diffusion film produced by the preferred embodiment of the present invention.

Figure 2 shows a schematic view of the manufacturing process of the diffusion film according to an embodiment of the present invention.

Figure 3 shows a schematic perspective view of the diffusion film produced by the preferred embodiment of the present invention.

Figure 4 shows the position of the lens shape in the diffusion film produced by the preferred embodiment of the present invention.

Claims (14)

In the diffusion film of the multi-layer structure consisting of a surface layer, an intermediate layer and a back layer, Roughness is provided between the plurality of lens shapes and the lens shape to the surface layer, and the roughness is given to the back layer, The roughness applied to the surface layer or the back layer is a diffusion film with a diffusion and shielding function, characterized in that the Rz value of 4 to 10㎛, Ra value of 1 to 2㎛. The method of claim 1, The diffusion film is a diffusion film having a diffusion and shielding function manufactured by extrusion extrusion method. delete The method according to claim 1 or 2, The surface layer is a diffusion film having a diffusion and shielding function, characterized in that the lens shape is uniformly arranged in the same size. 5. The method of claim 4, Diffusing film having a diffusion and shielding function, characterized in that the diameter of the lens layer of the surface layer is 40 to 60㎛. The method according to claim 1 or 2, The interlayer is a blend or composition of copolyester and polycarbonate, the diffusion film having a diffusion and shielding function comprising 10 to 90% by weight of copolyester and 10 to 90% by weight of polycarbonate. The method according to claim 1 or 2, The intermediate layer is methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, normal butyl methacrylate, normal butyl methyl methacrylate, acrylic acid, methacrylic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate Homopolymers of monomers selected from latex, hydroxyethyl acrylate, acrylamide, metarollacrylamide, glycidyl methacrylate, ethyl acrylate, isobutyl acrylate, normal butyl acrylate and 2-ethylhexyl acrylate, A diffusion film having a diffusion and shielding function further comprising at least one light diffusing particle made of a copolymer or a terpolymer, polyethylene, polystyrene, polypropylene, acryl and olefin-based beads and silicon-based spherical particles. In the manufacturing method of the diffusion film, Melt-extruding the polymer resin into three layers of a surface layer, an intermediate layer, and a back layer on a film; Engraving the extruded film such that the surface layer is provided with a lens shape and roughness, and the back layer is provided with roughness; And Method for producing a diffusion film having a diffusion and shielding function comprising the step of cooling the stamped film. The method of claim 8, The cooling step is quenching, but a method for producing a diffusion film having a diffusion and shielding function consisting of 4 to 20 ℃ cooling air. The method of claim 8, The roughness applied to the surface layer or the back layer is Rz value of 4 to 10㎛, Ra value of 1 to 2㎛ manufacturing method of the diffusion film having a diffusion and shielding function. The method of claim 8, The surface layer is a method of manufacturing a diffusion film having a diffusion and shielding function, characterized in that the lens shape is uniformly arranged in the same size. The method of claim 11, Lens surface diameter of the surface layer is a manufacturing method of the diffusion film having a diffusion and shielding function, characterized in that 40 to 60㎛. The method of claim 8, The intermediate layer is a blend or composition of the copolyester and polycarbonate 10 to 90% by weight of the copolyester and 10 to 90% by weight of the polycarbonate containing a diffusion and shielding method for producing a film. The method of claim 8, The intermediate layer is methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, normal butyl methacrylate, normal butyl methyl methacrylate, acrylic acid, methacrylic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate Homopolymers of monomers selected from latex, hydroxyethyl acrylate, acrylamide, metarollacrylamide, glycidyl methacrylate, ethyl acrylate, isobutyl acrylate, normal butyl acrylate and 2-ethylhexyl acrylate, Preparation of diffusion film having a diffusion and shielding function further comprising one or more selected light diffusing particles consisting of beads and silicon-based spherical particles made of a copolymer or terpolymer, polyethylene, polystyrene, polypropylene, acryl and olefin copolymer Way.

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