KR20110108856A - Brightness enhancement film - Google Patents

Abstract

Even if the number of island components in the birefringent island-in-the-sea yarn is drastically increased, the present invention provides a luminance-enhanced film that can not only prevent the bonding but also improve the phenomenon of cows.

Description

Brightness Enhancement Film {BRIGHTNESS ENHANCEMENT FILM}

The present invention relates to a luminance-enhanced film, and more particularly, to a luminance-enhanced film that can not only prevent the lamination but also improve the cow phenomenon even if the number of birefringent island-in-the-sea components is significantly increased.

Flat panel display technology is mainly made up of liquid crystal display (LCD), projection display, and plasma display (PDP), which have already secured market in TV, and related technologies such as field emission display (FED) and electroluminescent display (ELD) With the improvement of the market, it is expected to occupy the field according to each characteristic. LC displays are currently expanding their range of use, including notebooks, personal computer monitors, liquid crystal TVs, automobiles, and airplanes, accounting for about 80% of the flat panel market. have.

Conventional LC displays place liquid crystals and electrode matrices between a pair of light absorbing optical films. In an LC display, the liquid crystal portion has an optical state that is changed accordingly by moving the liquid crystal portion by an electric field generated by applying a voltage to two electrodes. This process displays an image of a 'pixel' carrying information using polarization in a specific direction. For this reason, LC displays include front and back optical films that induce polarization.

  The luminance-enhanced film of such an LC display is not necessarily a high utilization efficiency of light emitted from the backlight. This is because at least 50% of the light emitted from the backlight is absorbed by the rear optical film. Thus, in order to increase the utilization efficiency of the backlight light in the brightness enhancement film, the brightness enhancement film is provided between the optical cavity and the liquid crystal assembly.

  1A is a view showing the optical principle of a conventional brightness enhancement film. Specifically, P-polarized light from the optical cavity to the liquid crystal assembly passes through the luminance-enhanced film to be transmitted to the liquid crystal assembly, and S-polarized light is reflected from the luminance-enhanced film to the optical cavity and then polarized light on the diffuse reflection surface of the optical cavity. The direction is reflected in a randomized state and then transmitted to the luminance-enhanced film so that S-polarized light is converted into P-polarized light that can pass through the polarizer of the liquid crystal assembly, and then passed through the luminance-enhanced film and then transferred to the liquid crystal assembly.

The selective reflection of S-polarized light and the transmission of P-polarized light with respect to the incident light of the luminance-enhanced film have a refractive index between the optical layers in a state where an optical layer on a plate having anisotropic refractive index and an optical layer on a plate having an isotropic refractive index are alternately stacked. It is made by the optical thickness setting of each optical layer and the refractive index change of the optical layer according to the difference and the stretching process of the stacked optical layers.

  That is, the light incident on the luminance-enhanced film repeats the reflection of S-polarized light and the transmission of P-polarized light while passing through each optical layer, and eventually only the P-polarized light of the incident polarization is transmitted to the liquid crystal assembly. On the other hand, the reflected S-polarized light is reflected in a state in which the polarization state is randomized at the diffuse reflection surface of the optical cavity and is transmitted to the luminance-enhanced film as described above. As a result, power loss can be reduced together with the loss of light generated from the light source.

  However, such a conventional brightness enhancement film is laminated with anisotropic optical layer and anisotropic optical layer on a plate having different refractive indices and stretched to obtain optical thickness and refractive index between each optical layer that can be optimized for selective reflection and transmission of incident polarization. Since it is manufactured to have, there is a problem that the manufacturing process of the luminance-enhanced film is complicated. In particular, since each optical layer of the luminance-enhanced film has a flat plate structure, it is necessary to separate P-polarized light and S-polarized light in response to a wide range of incident angles of incident polarization, so that the number of optical layers is excessively increased and the production cost is exponentially increased. There was a growing problem. In addition, due to the structure in which the number of laminated layers of the optical layer is excessively formed, there is a problem that the optical performance decrease due to light loss.

Accordingly, it has been found that the luminance-enhanced film including the birefringent island-in-the-sea yarn inside the substrate is advantageous in overcoming the above-described problem. Specifically, when the birefringent island-in-the-sea yarns were used, it was confirmed that the effects of light modulation efficiency and luminance improvement were remarkably improved compared with the case of using the conventional birefringent fibers. Among the parts constituting the island-in-the-sea yarn, the island component has anisotropy, and the sea portion partitioning the island component has isotropy. In this case, not only the interface between the island-in-the-sea yarn and the base material, but also the interface between the island components and the sea portion constituting the inside of the island-in-the-sea yarn has a birefringent interface, so that a birefringent interface occurs only at the interface between the base material and the birefringent fibers. Compared to the fiber, the light modulation effect is significantly increased, so that it can be applied to the actual industrial site by replacing the laminated luminance-enhanced film. Therefore, the use of birefringent island-in-the-sea yarn is superior to the use of conventional birefringent fibers, and the efficiency of brightness enhancement is excellent, and the optical properties of the island component and sea portion are different in the birefringent island-in-the-sea island, so that the birefringence in the island-in-sea yarn What can form an interface is that the brightness enhancement efficiency can be remarkably improved as compared with the case where it is not.

On the other hand, in order to maximize the light modulation efficiency, the larger the area of the birefringent interface inside the birefringent islands, the more advantageous, the number of island components in the birefringent islands should be larger. However, the conventional islands and islands are arranged concentrically around a single spinning core inside the islands, and the cross-sectional structure of the island is not abnormal when the number of island components is small, but when the number of island components increases (about 300 or more), in the case of the island component adjacent to the spinning core formed in the center of the island-in-the-sea yarn, the density becomes large, and a phenomenon of agglomeration (conjugation phenomenon) occurs in the conductive parts located around the spinning core in the spinning process. More specifically, FIG. 1B is a cross-sectional view of a conventional islands-in-the-sea yarn (the island component 331 degrees), wherein the island components 12 are arranged concentrically around a single radiation core 11 in the island-in-the-sea yarn, The cross-sectional area of the island component is 30 to 70%. This cross-sectional structure does not have an abnormality when the number of island components is small, but when the number of island components increases (about 300 or more) or when the ratio of the cross-sectional area of the island components in the islands of the sea island becomes high, a spinning core formed at the center of the islands In the case of the island component adjacent to (11), the density becomes large, and in the spinning process, the phenomenon of agglomeration of the islands located around the spinning core occurs. In other words, as the number of island components in the islands of the sea island increases, there is a side effect (conjugation phenomenon) in which the island components of the central island of the islands agglomerate to form a lump.

Therefore, the birefringent island-in-the-sea yarn having a cross-sectional shape of a conventional island-in-the-sea yarn has a problem that the birefringence interface is reduced due to the degree of conduction bonding, and thus the optical modulation efficiency is not significantly improved.

The present invention has been made to solve the above-described problems, the first problem to be solved by the present invention includes a birefringent sea island that does not occur even when the number of island components significantly conjugation and shearing phenomenon It is to provide a brightness enhancement film.

A second object of the present invention is to provide an island-in-the-sea yarn that can be used in a luminance-enhanced film and has color development in itself.

In order to solve the 1st subject of this invention mentioned above, it is described; A birefringent island-in-the-sea yarn is included in the substrate to generate a light modulation effect, and the birefringent island-in-the-sea yarn includes a core portion and a plurality of island component groups radially formed around the core portion to prevent the joining therein. It provides a brightness enhancement film containing a birefringent islands.

According to an exemplary embodiment of the present invention, a boundary portion having a smaller number of island components per unit area (μm 2) formed at a boundary between adjacent island component groups than the number of island components per unit area (μm 2) in the island component group is formed. And adjacent boundary component groups can be partitioned by the boundary.

According to another preferred embodiment of the present invention, the boundary portion may be formed radially around the core portion.

According to another preferred embodiment of the present invention, the number of island components per unit area (μm ² ) of the core portion may be smaller than the number of island components per unit area (μm ² ) of the island component group, and preferably 1 / It may be 2 or less or 1/3 or less. Also, the number of island components per unit area (μm ² ) of the boundary portion may be smaller than the number of island components per unit area (μm ² ) in the island component group, and preferably, 3/4 or less or 1/2 or less.

According to another preferred embodiment of the present invention, at least one annular boundary portion may be formed around the core portion.

According to another preferred embodiment of the present invention, the cross-sectional shape of the island component group may be a sector, an isosceles triangle or an isosceles trapezoid.

According to another preferred embodiment of the present invention, the number of the plurality of island component groups may be 10 to 50, the number of island components contained in one island component group may be 800 to 2000.

According to another preferred embodiment of the present invention, the total number of island components contained in the birefringent islands in the yarn may be 20000 ~ 30000 pieces.

According to another preferred embodiment of the present invention, the birefringent island-in-the-sea yarn may have an A value of 500 or more.

[Relationship 1]

A = number of strands / strands of mono yarn

According to another preferred embodiment of the present invention, the birefringent island-in-the-sea yarn is woven in the form of a fabric, one of the weft or warp of the fabric is a birefringent island-in-the-sea yarn and the other may be a fiber.

According to another preferred embodiment of the present invention, the melting start temperature of the island component of the birefringent island-in-the-sea yarn may be higher than the melting temperature of the fiber.

According to another preferred embodiment of the present invention, the birefringent island-in-the-sea yarn may be woven into mono yarns.

According to another preferred embodiment of the present invention, a birefringent interface may be formed at the boundary between the island component and the sea portion of the birefringent island-in-the-sea yarn, and more preferably, the optical property of the island component is birefringent, and the optics of the sea portion The property may be isotropic.

According to another preferred embodiment of the present invention, the fiber may be an isotropic fiber having optical properties.

According to another preferred embodiment of the present invention, the fiber may be any one or more fibers selected from the group consisting of polymer fibers, natural fibers and inorganic fibers.

According to another preferred embodiment of the present invention, the melting start temperature of the island component of the birefringent island-in-the-sea yarn may be higher than the melting temperature of the sea portion.

According to another preferred embodiment of the present invention, the melting start temperature of the island component of the birefringent island-in-the-sea yarn may be 30 ° C. or more higher than the melting temperature of the fiber, and the melting start temperature of the island component of the birefringent island-in-the-sea yarn is dissected. It may be at least 30 ° C. above the melting temperature of the minute.

According to another preferred embodiment of the present invention, the fiber and / or sea portion may be part or all melted.

According to another preferred embodiment of the present invention, the sea portion of the fiber and the birefringent island-in-the-sea yarn may be the same component.

According to another preferred embodiment of the present invention, the refractive index of the substrate and the birefringent island-in-the-sea yarn may have a difference in refractive index of 0.05 or less in two axial directions and a difference in refractive index of the other one axial direction of 0.1 or more. .

According to another preferred embodiment of the present invention, the refractive index of the substrate in the x-axis direction is nX1, the y-axis refractive index is nY1 and the z-axis refractive index is nZ1, the birefringent islands of the refractive index is nX2, nY2 and When nZ2, at least one of the X, Y, and Z-axis refractive indices of the substrate and the birefringent island-in-the-sea yarn may coincide.

According to another preferred embodiment of the present invention, the refractive index of the sea portion and the island component of the birefringent island-in-the-sea yarn has a difference in refractive index of 0.05 or less in two axial directions, and a difference in refractive index of one remaining axial direction in 0.1 It may be abnormal.

According to another preferred embodiment of the present invention, the refractive index in the x-axis direction in the longitudinal direction of the island component of the birefringent island-in-the-sea yarn is nX3, the refractive index in the y-axis direction is nY3 and the refractive index in the z-axis direction is nZ3, the sea portion When the refractive index of the x-axis direction is nX4, the y-axis direction of the refractive index nY4 and the z-axis direction of the refractive index is nZ4, at least any one of the X, Y, Z-axis refractive index of the substrate and the birefringent islands.

According to another preferred embodiment of the present invention, the absolute value of the difference between the refractive index of the nX3 and nX4 may be 0.1 or more.

According to another preferred embodiment of the present invention, the diameter of the birefringent island-in-the-sea yarn may be 10 ~ 100 ㎛.

In order to solve the second problem of the present invention described above, there is provided a island-in-the-sea yarn comprising a core portion preventing the joining of the island inside the island-in-the-sea yarn and a plurality of island component groups radially formed around the core portion.

According to another preferred embodiment of the present invention, the island component per unit area of the inner group (㎛ ²⁾ island component per unit area formed on a boundary between the groups adjacent than the number of island component (㎛ ²⁾ a small number of the island component boundary Are formed and adjacent islands groups can be partitioned by the boundaries.

According to another preferred embodiment of the present invention, the boundary portion may be formed radially around the core portion.

According to another preferred embodiment of the present invention, the boundary portion may be formed radially around the core portion.

According to another preferred embodiment of the present invention, the number of island components per unit area (μm 2) of the core portion may be smaller than the number of island components per unit area (μm 2) of the island component group.

According to another preferred embodiment of the present invention, at least one annular boundary portion may be formed around the core portion.

According to another preferred embodiment of the present invention, the cross-sectional shape of the island component group may be a sector, an isosceles triangle or an isosceles trapezoid.

According to another preferred embodiment of the present invention, the number of the plurality of island component groups may be 10 to 50, the number of island components contained in one island component group may be 800 to 2000.

According to another preferred embodiment of the present invention, the total number of island components contained in the birefringent islands in the yarn may be 20000 ~ 30000 pieces.

The terms used herein are briefly described.

'Fiber has birefringence' means that when light is irradiated on a fiber having a different refractive index according to the direction, the light incident on the polymer is refracted by two lights having different directions.

'Isotropic' means that when light passes through an object, the refractive index is constant regardless of the direction.

'Anisotropy' means that the optical properties of an object are different depending on the direction of light. Anisotropic objects have birefringence and correspond to isotropy.

'Light modulation' means that the irradiated light is reflected, refracted, scattered, or the intensity of the light, the period of the wave, or the nature of the light is changed.

The 'core portion' refers to a radially conductive island group and a portion that is the radiation center of the boundary portion, and means a portion having a predetermined area in order to prevent conduction in the cross section of the island-in-the-sea yarn.

The 'melting start temperature' refers to the temperature at which the melting of a polymer begins, and the 'melting temperature' refers to the temperature at which melting occurs most rapidly. Therefore, when the melting temperature of a polymer is observed by DSC, if the end point of the endothermic peak due to melting is the melting start temperature, the temperature corresponding to the vertex of the endothermic peak is the melting temperature.

'Photochromic fiber' refers to a fiber whose color is expressed by the interference of light due to the structural / optical design of the fiber, rather than being colored by the physical / chemical combination of a material having a color such as a dye or a pigment. Means.

In the luminance-enhanced film including the birefringent island-in-the-sea yarn according to the present invention, even when the number of island components is 20,000 or more, the aggregation of island components does not occur in the central portion of the islands of the islands. Therefore, since more than 20,000 islands can be formed inside one island-in-the-sea yarn, the area of the light modulation interface can be maximized, so that the light modulation effect is significantly increased. Therefore, the luminance-enhanced film including the island-in-the-sea yarn of the present invention has excellent light modulation effect, and thus, compared with the case of using a conventional island-in-the-sea yarn having about 500 birefringent fibers or island components, Since the area is significantly increased, the brightness is dramatically improved.

In addition, even when weaving a birefringent island-in-the-sea yarn in the form of a woven fabric and including it in the luminance-enhanced film, since the number of island components is large in the mono yarn (birefringent island-in-the-sea yarn), desired improvement in luminance can be achieved only by mono yarn. In the case of weaving a birefringent island-in-the-sea yarn for weaving to improve the luminance, weaving and trimming are not generated.

Furthermore, the island-in-the-sea yarn that can be applied to the luminance-enhanced film of the present invention can arrange the island components, thereby reducing the fineness of the island components, which is very advantageous for producing ultra-fine yarns, and the number of island components in one island-in-the-sea yarn is more than 20,000. Microfiber can be produced, significantly reducing the production cost. In addition, in the case of using the island-in-the-sea yarn without using microfiber yarn, it can be used as a photochromic fiber by expressing a specific color according to the island-in-sea ratio and fiber diameter without adding a compound causing color development such as dye due to its excellent light modulation effect. Can be. The photochromic fiber of the present invention may be colored in various colors depending on the intensity, position and viewing angle of light.

1A is a schematic diagram illustrating the principle of a conventional brightness enhancing film.
1B is a cross-sectional photograph of a conventional birefringent island-in-the-sea yarn.
FIG. 2A is a cross-sectional photograph of a birefringent island-in-the-sea yarn, and FIG. 2B is a capped partial plate for manufacturing the birefringent island-in-the-sea yarn of FIG. 2A, and FIGS. 2C and 2D are electron microscopes of the fabric including the birefringent island-in-the-sea yarn of FIG. 2A. It is a photograph.
3 is an electron micrograph of a cross-sectional view of the island-in-the-sea yarn in accordance with a preferred embodiment of the present invention.
Figure 4 is an electron micrograph of the island-in-the-sea cross-section according to a preferred embodiment of the present invention.
5 is a photograph of the fabric used in the luminance-enhanced film including the island-in-the-sea yarn of the present invention according to a preferred embodiment of the present invention.
Figure 6 is a cross-sectional view of the detention part partial plate for island-in-the-sea manufacture according to a preferred embodiment of the present invention.
7 is a cross-sectional view of the lower plate of the island for manufacturing sea islands according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail with reference to the accompanying drawings.

As described above, the island-in-the-sea yarn manufactured using the spinneret for manufacturing the island-in-the-sea yarn is arranged in a concentric shape around a single spinning core or randomly arranged without the spinning core. Such a cross-sectional structure is not abnormal when the number of island components is small, but when the number of island components increases (about 300 or more), the density of islands adjacent to the spinning core formed at the center of the island is increased, In the spinning process, agglomeration occurs in the conductive parts located around the spinning core. In other words, as the number of island components in the islands of the sea island increases, the island components of the center portion of the islands of the islands agglomerate to form a mass (FIG. 1B).

Accordingly, the inventors of the present invention manufactured a luminance-enhanced film employing birefringent island-in-the-sea yarns having the number of mono-conducting components of 1016 through Korean Patent Application No. 2009-7642 through spinnerets including the depressed partial plate of FIG. 2B. . FIG. 2A is a birefringent island-in-the-sea yarn of 1016 degrees described above, and even when the number of birefringent island-in-the-sea yarns exceeds 500, the splice phenomenon does not occur in the center portion of the island-in-the-sea yarn. However, even in the case of the birefringent island-in-the-sea yarn (mono yarn) of FIG. 2A, the mono yarn (diameter: 19 mu m) itself has low light modulation efficiency, so it is actually 40 de (denier) / 12 fila (strand). , 80/24 (de / fila) was plywooded and woven into a fabric and placed inside the luminance-enhanced film. Specifically, FIGS. 2C and 2D show the fabric 60 including the birefringent island-in-the-sea yarn of FIG. 2A, wherein the fabric 60 is a warp and the birefringent island-in-the-sea yarn 61 (monosa) is 80/24 ( de / fila) and weaved isotropic fibers 62 as weft yarns to weave the fabric. As a result, the light modulation efficiency was improved, but the diameter of the mono yarn was small and the number of strands was increased. Some trims (A, B, and C of FIG. 2C) appeared in some mono yarns, resulting in the occurrence of blemishes and defects in the luminance-enhanced film. It became. Furthermore, the birefringent islands of Korea Patent Application No. 2009-7642 by themselves were still more likely to have a splicing phenomenon when the number of island components exceeds 10,000.

Accordingly, in the present invention, in order to solve the first problem of the present invention, a birefringent island-in-the-sea yarn comprising a base material, a core part for preventing conjugation inside the base material, and a plurality of island component groups radially formed around the core part. The above-mentioned problem was solved by providing an included luminance-enhanced film. As a result, even when the number of island components in the birefringent island-in-the-sea yarn is more than 20,000, the doping phenomenon does not occur. Therefore, since the birefringent interface is increased in the birefringent island-in-the-sea yarn, it is possible to maintain high luminance even when only mono yarn is used without fabricating the birefringent island-in-the-sea yarn in fabric production. As a result, no entanglement and trimming between the mono yarns contained in the luminance-enhanced film do not occur, so that no phenomenon occurs. As a result, not only the defects appear in the luminance-enhanced film but also the reverse polarization phenomenon does not appear, so that the luminance can be maintained uniformly.

When the birefringent islands included in the luminance-enhanced film of the present invention in detail with reference to Figure 3, Figure 3 is a birefringent islands included in the luminance-enhanced film according to an embodiment of the present invention As a cross-sectional photograph (1000 times magnification), the birefringent island-in-the-sea yarn of the present invention includes a core portion 510 for preventing the joining and a plurality of island component groups 520 and 530 radially formed around the core portion 510. Include.

First, the core portion 510 formed inside the birefringent island-in-the-sea yarn will be described. The core part 510 of the present invention is formed inside the birefringent island-in-the-sea yarn to prevent the joining. Preferably, the core part 510 is formed at the center of the birefringent island-in-the-sea yarn and surrounded by the vertices of the island component groups 520 and 530. Can be. In general, as the number of birefringent island-in-the-sea yarns increases, the density of the island-in-the-sea components increases in the central portion of the island-in-the-sea yarns, resulting in the formation of a joint. Accordingly, in the present invention, the core portion 510 is formed inside the birefringent island-in-the-sea yarn to prevent the bonding even when the number of the island components is significantly increased. On the other hand, preferably, the core part 510 is much more resistant to conjugation as the number of island components per unit area (μm ² ) is smaller than the number of island components per unit area (μm ² ) in the island component group. It is advantageous. Specifically, C in FIG. 3 is a constant region of the core portion, and A is a constant region inside the island component group. When comparing C and A, the number of island components per unit area (μm ² ) is much smaller than that of A. have. In the process of spinning through the spinneret, the birefringent sea island causes the island component to expand and disperse due to the dieswelling phenomenon. Therefore, if the empty space (the same is true when only sea component is formed) is formed in the center part of island island in the early stage of spinning, island component will be dispersed and expand to the center part of island island at the end of spinning. Since the island component does not exist, the die-bonded island component does not generate a conjugation phenomenon where the island components are agglomerated together at the center of the island-in-the-sea yarn. As a result, in the early stages of spinning, empty spaces are formed in the core portion of the island-in-the-sea yarn, but the island component is expanded and dispersed to the core portion by die swelling during the spinning process. However, since there was almost no island component in the core portion of the island-in-the-sea yarn from the beginning, even if dieswelling occurred, the island component of the island component per unit area (μm ² ) was larger than the number of island components in the island component group. The number is remarkably small. Preferably, the number of (μm ² ) islands per unit area may be 1/2 or less, and more preferably 1/3 or less. On the other hand, the basis of the unit area is enough to compare the number of island components of the core portion 510 and the island component groups 520 and 530 on the same basis, and preferably compare the number of island components per μm ² . May be, but is not limited thereto.

On the other hand, according to a preferred embodiment of the present invention, the core portion 510 has a predetermined diameter and the area according to the degree that no doping occurs, wherein the predetermined diameter and area is the diameter of the birefringent islands, It may have an appropriate size or more depending on the number of island components. Preferably, when the shape of the core part 510 is circular, the diameter may be 0.2 to 5 μm, and when the elliptical shape is the long axis, the diameter of the major axis may be 0.5 to 10 μm. The length to the vertex may be 0.5 to 10 μm, but the length of the vertex is not limited thereto, and the core part 510 may be a region having a smaller density of the island component than the island component group to prevent the joining.

Next, the island component groups 520 and 530 and the boundary portion 540 separating the island component groups 520 and 530 will be described. First, the island component of the present invention refers to an ultrafine fiber contained in the birefringent island-in-the-sea yarn, and the island components are gathered to form one island component group, and a plurality of island component groups exist. In detail, a plurality of island component groups 520 and 530 of the present invention are radially formed around the core part 510 described above, and the plurality of island component groups 520 and 530 are adjacent island component groups 520. It may be partitioned by the boundary portion 540 formed between the, 530. In this case, the boundary portion 540 may be formed radially around the core portion 510. In this case, the number of boundary portions 540 may be one or more smaller than the number of island component groups. On the other hand, preferably, the boundary formed between adjacent island component groups 520 and 530 similarly to the core portion 510 is also a boundary between neighboring island component groups rather than the number of island components per unit area (μm ² ) within the island component group. The small number of (μm ² ) island components per unit area formed in the is very advantageous to prevent the conduction. Specifically, B in FIG. 3 is a predetermined region of the boundary portion 540, and A is a predetermined region inside the island component group 520. When B and A are compared, B is the number of island components per unit area (μm ² ) compared to A. It can be seen that is relatively small. In the process of spinning through the spinneret, the birefringent sea island causes the island component to expand around due to the dieswelling phenomenon. Therefore, if the boundary portion (which may be formed as a sea component) is formed between the island component group and the group at the beginning of spinning, the island component expands to the boundary portion after the radiation is completed. Since no powder is present, the diced island component can expand to the boundary of the island-in-the-sea yarn to reduce the density of the island component within the island component group. As a result, it is possible to solve the problem of the joining caused by the high density of the island component. Furthermore, since there was almost no island component at the boundary of the island-in-the-sea yarn at the beginning of radiation, even if dieswelling occurred, per unit area of the island component group (µm ² ), as per unit area of the boundary region (µm ² ) The number of island components is remarkably small. Preferably, the number of (μm ² ) island components per unit area may be 3/4 or less, and more preferably 1/2 or less. On the other hand, the basis of the unit area is enough to compare the number of island components of the boundary portion 540 and the island component groups 520 and 530 on the same basis, and preferably the number of island components per μm ² can be compared. However, it is not limited thereto.

Meanwhile, according to another preferred embodiment of the present invention, the boundary portion may be radially formed around the core portion, and at least one annular boundary portion may be formed around the core portion, and the annular boundary portion may be continuous or intermittent. Can be.

According to one aspect of the present invention, the cross-sectional shape of the island component group may be applied without limitation as long as it can be formed radially about the core portion 510, but preferably may be a fan, an isosceles triangle, or an equilateral trapezoid.

According to another aspect of the present invention, the number of the plurality of island component groups may be preferably 10 to 50, and the number of island components included in one island component group may be preferably 800 to 2000. .

According to another aspect of the present invention, the total number of island components included in the birefringent island-in-the-sea yarn may be 20000 to 30000. Specifically, FIGS. 3 and 4 are optical photographs of birefringent islands in accordance with the preferred embodiment of the present invention, wherein the birefringent islands have 20 island component groups and the number of island components included in one island component group There are 1250 and 25,000 islands are included in the total birefringent islands. Therefore, the birefringent island-in-the-sea yarn according to the present invention preferably forms 10000 or more, more preferably 20,000 or more, of the island components therein, and when used in the brightness-enhanced film, it is possible to improve the brightness while preventing the occurrence of cows. The effect can be maximized.

Meanwhile, the diameter of the birefringent island-in-the-sea yarn of the present invention is not limited, but preferably 10 to 100 μm, more preferably 40 to 100 μm.

On the other hand, as described above, even when the number of birefringent islands in which the number of island components of FIG. 2A is 1016 is greater than 500, the degree of conduction does not occur, but the number of island components is 10000 or more under the same conditions. In this case, not only the splicing but also the weaving with 80/24 (de / fila) and weaving it as weft or warp of the fabric as shown in FIGS. Was done. Thus, according to another aspect of the present invention, when the birefringent island-in-the-sea yarn of the present invention has an A value of 500 or more, entanglement and trimming between the mono yarns contained in the luminance-enhanced film do not occur, so that no hair loss occurs. Do not. As a result, not only the defects appear in the luminance-enhanced film but also the reverse polarization phenomenon does not appear, so that the luminance can be maintained uniformly.

[Relationship 1]

A = the number of strands in the mono yarn / the number of strands

In other words, in the conventional birefringent islands, when the number of islands is 300, 50 strands are used, or when the number of islands is 1016, 12 strands are used. The values are 6, 84.7, far below 500. On the contrary, when the birefringent island-in-the-sea yarn of the present invention is used at 25000 degrees (1 strand), 15000 degrees (2 strands), or the like, the A value is 25000, 7500, and thus exceeds 500. At this time, since the use of mono yarns rather than plunging multiple strands significantly reduces the possibility of occurrence of hair phenomena due to fiber entanglement and fiber trimming, more preferably A value is 1000 or more, 5000 or more, 10000 or more. Alternatively, it is advantageous to use birefringent island-in-the-sea yarn of 20000 or more, and most preferably, the use of 10000 or 20,000 or more birefringent island-in-the-sea yarns in combination with mono yarn or two strands is used to prevent fiber entanglement and hair phenomena. It is effective and most preferably weaving in the form of mono yarns is most effective. Figure 5 is a birefringent island-in-the-sea yarn (25000 number of island components) of the preferred embodiment of the present invention as a woven fabric with a mono yarn inclined as shown in FIG. Does not occur.

On the other hand, if the birefringent island-in-the-sea yarns are not fused with mono yarns having the same number of island components, and mono yarns having various numbers of island components are fused together (for example, 10 mono yarns having 300 islands and the figure In the case of 10 mono yarns having 500 parts), the average value may be defined as the number of island parts of a mono yarn.

According to another aspect of the present invention, the melting start temperature of the island portion of the birefringent island-in-the-sea yarn may be higher than the melting temperature of the fiber and / or sea portion. When the birefringent island-in-the-sea yarn is included in the luminance-enhanced film itself, the birefringent island-in-the-sea yarn is easily moved in the lamination process or the like, so it is difficult to properly arrange it. Therefore, when the woven fabric including the birefringent island-in-the-sea yarn is woven and the fabric is placed between the substrates and laminated, the birefringent island-in-the-sea yarn is fixed so that it can be properly disposed. However, when the birefringent island-in-the-sea yarn in the luminance-enhanced film is inserted into the form of the fabric rather than the fiber itself, when it is included and used in the liquid crystal display, the light is irradiated from the outside even when the fiber constituting the fabric is used as a transparent material. (In the case of the light passing through the luminance-enhanced film in the light source of the liquid crystal display) The phenomenon that the inner fabric (fiber) is visible to the outside appeared to be a big obstacle to commercialization.

Accordingly, the present invention solves the above-described problem by providing a luminance-enhanced film in which the melting start temperature of the island portion of the birefringent island-in-the-sea yarn is higher than the melting temperature of the fiber and / or sea portion.

First, the fabric included in the luminance-enhanced film of the present invention will be described with reference to FIG. 5 is a schematic representation of a fabric that may be used in the present invention. First, the fabric may be made of weft and warp yarns, either of which are weft yarns or warp yarns, which are birefringent islands, and the other is fiber. In other words, when the birefringent island-in-the-sea yarn is used as the weft yarn, the fiber is inclined, and when the birefringent island-in-the-sea yarn is used as the warp yarn as shown in FIG. On the other hand, weft and warp constituting the fabric may be a transparent material so that light can be transmitted.

According to an aspect of the present invention, the melting start temperature of the island portion of the birefringent island-in-the-sea yarn may be higher than the melting temperature of the fiber. Through this, the fabric is placed between the substrates and subjected to heat and / or pressure to perform the lamination process when the lamination process is carried out at a temperature between the melting temperature of the fiber and the melting start temperature of the coating portion. It is not melted because it is not, but because the lamination process is performed at a temperature higher than the melting temperature of the fiber, the fiber is partially or fully melted. As a result, the weaved weft or warp fibers are melted in the lamination process and become part of the substrate, leaving only the birefringent islands in the final luminance-enhanced film. Therefore, the fiber visible phenomenon that occurs when including the fabric can be significantly improved. Therefore, the melting initiation temperature of the island portion of the birefringent island-in-the-sea yarn is higher than the melting temperature of the fiber, but preferably the melting initiation temperature of the island portion of the birefringent island-in-the-sea yarn may be 30 ° C. or more higher than the melting temperature of the fiber, and more preferably. Preferably higher than 50 ° C.

Further, the melting start temperature of the island portion of the birefringent island-in-the-sea yarn may be higher than the melting temperature of the sea portion, and more preferably, the melting start temperature of the island portion of the birefringent island-in-the-sea yarn may be 30 ° C. or more higher than the melting temperature of the sea portion. have. As a result, the sea portion of the birefringent island-in-the-sea yarn may be partially or fully melted. On the other hand, according to a preferred embodiment of the present invention, the melting start temperature of the island portion of the birefringent islands may be 130 ~ 430 ℃, the melting temperature of the isotropic fibers may be 100 ~ 400 ℃, the birefringent islands Melting temperature of the sea portion of the yarn may be 100 ~ 400 ℃ and the lamination temperature may be 100 ~ 420 ℃ but is not limited thereto.

After all, the luminance-enhanced film including the fabric according to the present invention has a melting start temperature of the isotropic fibers forming the weft or warp of the fabric is lower than the melting start temperature of the birefringent islands of the warp yarn forming another weft or warp, the melting start temperature of the isotropic fibers When the lamination process is performed at a temperature between the temperature of the birefringent island-in-the-sea yarn and some or all of the isotropic fibers are melted, it is possible to solve the fiber visible phenomenon of the luminance-enhanced film. Furthermore, since the melting temperature of the sea portion of the birefringent island-in-the-sea yarn is lower than the melting start temperature of the island portion, when the lamination process is performed at the temperature therebetween, part or all of the sea portion is melted and the lamination process is performed at the temperature therebetween. If part or all of the seam is melted to have the effect of laminating the sheet and the fabric into a single layer without a separate adhesive.

Next, the description that can be used in the present invention will be described. Materials used for the substrate include thermoplastic and thermosetting polymers that transmit a desired wavelength of light and may be a transparent or translucent material that is easy to transmit light. Preferably suitable substrates may be amorphous or semicrystalline and may comprise homopolymers, copolymers or blends thereof. Specifically poly (carbonate) (PC); Syndiotactic and isotactic poly (styrene) (PS); Alkyl styrenes; Alkyl, aromatic and aliphatic ring containing (meth) acrylates including poly (methylmethacrylate) (PMMA) and PMMA copolymers; Ethoxylated and propoxylated (meth) acrylates; Polyfunctional (meth) acrylates; Acrylated epoxy; Epoxy; And other ethylenically unsaturated substances; Cyclic olefins and cyclic olefin copolymers; Acrylonitrile butadiene styrene (ABS); Styrene acrylonitrile copolymer (SAN); Epoxy; Poly (vinylcyclohexane); PMMA / poly (vinylfluoride) blends; Poly (phenylene oxide) alloys; Styrene block copolymers; Polyimide; Polysulfones; Poly (vinyl chloride); Poly (dimethylsiloxane) (PDMS); Polyurethane; Unsaturated polyesters; Polyethylene; Poly (propylene) (PP); Poly (alkane terephthalates) such as poly (ethylene terephthalate) (PET); Poly (alkane naphthalate) such as poly (ethylene naphthalate) (PEN); Polyamides; Ionomers; Vinyl acetate / polyethylene copolymers; Cellulose acetate; Cellulose acetate butyrate; Fluoropolymers; Poly (styrene) -poly (ethylene) copolymers; PET and PEN copolymers, including polyolefin PET and PEN; And poly (carbonate) / aliphatic PET blends. More preferably, polyethylene naphthalate (PEN), polyethylene naphthalate copolymer (co-PEN) polyethylene terephthalate (PET), polycarbonate (PC), polycarbonate (PC) alloy, polystyrene (PS), heat-resistant polystyrene (PS), polymethyl methacrylate (PMMA), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PE), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile mixture (SAN), ethylene vinyl acetate (EVA), polyamide (PA), polyacetal (POM), phenol, epoxy (EP), urea. (UF.MF), Unsaturated polyester (UP), Silicone (SI), Elastomer, Cycloolefin polymer (COP, Japan ZEON, JSR) can be used alone or in combination, more preferably birefringence The same components as the sea parts of the yarn may be used. Furthermore, the substrate may contain additives such as antioxidants, light stabilizers, heat stabilizers, lubricants, dispersants, ultraviolet absorbers, white pigments, fluorescent whitening agents, and the like, and the substrate is optically isotropic, so long as the above properties are not impaired. Can be.

On the other hand, the substrate may be configured in the same manner as the components and optical properties of the sea portion and / or fiber components and the optical properties of the substrate in consideration of various physical properties. In this case, part or all of the substrate may be melted in the lamination process, thereby improving adhesion between the birefringent islands and the substrate without using a separate adhesive. In this case, the substrate may have a three-stage layer, and specifically, the three-stage layer may be composed of a laminated structure of skin layer (A1) / core layer (B1) / skin layer (A2) by co-extrusion of a polymer. have. The skin layer corresponding to the fabric and corresponding to the outside of the sheet may have the same melting temperature as sea areas and / or fibers in order to improve adhesion with birefringent island-in-the-sea yarns, and the core layer may deform the sheet due to heat generation of the lamp. Materials with higher melting temperatures than sea areas and / or fibers may be used to prevent this.

Therefore, when the fabric of the structure described above is laminated between the sheets of the three-layer structure, the skin layer (A1) / core layer (B1) / skin layer (A2) / fabric / skin layer (A3) / core layer (B2) / It has the structure of the skin layer A4. At this time, when the skin layer and the sea portion and / or the melting temperature of the fiber is the same, the skin layer (A2, A3) and the fabric layer which is melted and laminated on the fabric layer may form almost one layer. have.

Next, the fibers that can be used as the weft or warp of the fabric of the present invention will be described. The fiber may be woven with birefringent island-in-the-sea yarn to form a fabric, and may be used without limitation as long as it satisfies the above-mentioned temperature conditions. Preferably, the fiber is optical in view of being woven perpendicular to the birefringent island-in-the-sea yarn. It is preferable that it is isotropic fiber. This is because when the fiber also has birefringence, light modulated through the birefringent island-in-the-sea yarn may not pass through the fiber. On the other hand, the fibers may be used alone or mixed with polymer fibers, natural fibers, inorganic fibers (glass fibers, etc.), and more preferably, fibers of the same material as the sea component of the birefringent island-in-the-sea yarn.

Next, the birefringent island-in-the-sea yarn used as the weft or warp yarn of the fabric of the present invention will be described. The birefringent island-in-the-sea yarn that may be used in the present invention may have different optical characteristics of the island portion and the sea portion in order to maximize light modulation efficiency. More preferably, the island portion is anisotropic and the sea portion may be isotropic.

Specifically, in an island-in-the-sea island comprising an optically isotropic sea portion and an island portion having anisotropy, the magnitude of the substantial coincidence or mismatch of the refractive indices along the X, Y, and Z axes in space affects the degree of scattering of the polarized light along the axis. Crazy In general, the scattering power varies in proportion to the square of the refractive index mismatch. Thus, the greater the degree of mismatch in refractive index along a particular axis, the more strongly scattered light polarized along that axis. Conversely, when the mismatch along a particular axis is small, the light polarized along that axis is scattered to a lesser extent. If the refractive index of the sea portion along a certain axis substantially coincides with the refractive index of the island portion, the incident light polarized by an electric field parallel to this axis will not be scattered regardless of the size, shape, and density of the portion of the island. Will pass. Also, when the refractive indices along that axis are substantially coincident, the light beam passes through the object without being substantially scattered. More specifically, FIG. 4 is a cross-sectional view showing a path of light transmitted through the birefringent island-in-the-sea yarn of the present invention. In this case, the P wave (solid line) is transmitted without being affected by the interface between the birefringent island-in-the-sea yarn and the interface between the island and the sea inside the birefringent island-in-the-sea yarn, while the S-wave (dotted line) The modulation of light occurs due to the influence of the birefringence interface between the boundary surface of the island and the sea portion inside the islands of the islands and / or birefringent islands.

The above-mentioned light modulation phenomenon at the birefringent interface mainly occurs at the interface between the substrate and the sea portion within the interface between the substrate and the birefringent island-in-the-sea yarn and inside the birefringent island-in-the-sea yarn. Specifically, when the optical property of the base material is isotropic, light modulation occurs at the interface between the base material and the birefringent island-in-the-sea yarn as in the case of ordinary birefringent fibers. More specifically, the refractive index of the substrate and the birefringent island-in-the-sea yarn may have a difference in refractive index of 0.05 or less in two axial directions, and a difference in refractive index of one remaining axial direction may be 0.1 or more. More specifically, when the refractive index in the x-axis direction of the substrate is nX1, the refractive index in the y-axis direction is nY1 and the refractive index in the z-axis direction is nZ1, and the refractive indexes of the birefringent island-in-the-sea yarns are nX2, nY2 and nZ2, At least one of the X, Y, and Z-axis refractive indices of the island-in-the-sea yarn may coincide, and the refractive index of the birefringent island-in-the-sea yarn may be nX2> nY2 = nZ2.

On the other hand, in the present invention, the optical quality of the island portion and the sea portion of the birefringent island-in-the-sea yarn is advantageous to create a birefringent interface. Specifically, when the island portion is anisotropic and the sea portion is isotropic, a birefringence interface may be formed at the interface between the island portion and the sea portion, and more preferably, the refractive index may be 0.05 or less in difference between the two indexes. It is preferable that the difference in refractive index with respect to one axial direction is 0.1 or more. In this case, P wave passes through the birefringent interface of island-in-the-sea yarn, but S wave can cause light modulation. In more detail, the refractive index in the x-axis direction in the longitudinal direction of the island portion of the birefringent island-in-the-sea yarn is nX3, the refractive index in the y-axis direction is nY3 and the refractive index in the z-axis direction is nZ3, and the refractive index in the x-axis direction of the sea portion When the refractive index in the nX4 and y-axis directions is nY4 and the refractive index in the z-axis direction is nZ4, at least one of the X, Y, and Z-axis refractive indices of the substrate and the birefringent island-in-the-sea yarn may coincide, and the refractive indices of the nX3 and nX4 The absolute value of the difference of may be 0.1 or more. Most preferably, the difference in refractive index in the longitudinal direction of the sea portion and the island portion of the island-in-the-sea yarn is 0.1 or more, and the optical modulation efficiency may be maximized when the refractive indices of the sea portion and the island portion in the remaining two axial directions substantially coincide. have. On the other hand, it is advantageous to increase the light modulation efficiency when the refractive index of the sea portion of the substrate and the birefringent islands.

Therefore, it is effective to improve the light modulation efficiency by selecting a material in which the refractive indexes in the two axial directions are substantially the same in the island portion and the sea portion of the birefringent islands.

The sea portion and / or island portion of the birefringent island-in-the-sea yarn that may be used in the present invention may be polyethylene naphthalate (PEN), copolyethylene naphthalate (co-PEN), polyethylene terephthalate (PET), polycarbonate (PC), Polycarbonate (PC) alloy, polystyrene (PS), heat-resistant polystyrene (PS), polymethyl methacrylate (PMMA), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PE), acrylo Nitrile Butadiene Styrene (ABS), Polyurethane (PU), Polyimide (PI), Polyvinyl Chloride (PVC), Styrene Acrylonitrile Mixture (SAN), Ethylene Vinyl Acetate (EVA), Polyamide (PA), Poly It may be at least one of acetal (POM), phenol, epoxy (EP), urea (UF), melanin (MF), unsaturated polyester (UP), silicone (SI), elastomer and cycloolefin polymer. Preferably, the material and the sea portion have substantially the same refractive index in two axial directions, but selecting a material having a large difference in refractive index in one axial direction is effective to improve the light modulation efficiency. However, most preferably, a birefringent island-in-the-sea yarn uses polyethylene naphthalate (PEN) as the island portion, and copolyethylene naphthalate and a polycarbonate alloy alone or mixed to be used as a sea portion are common materials. As compared with the birefringent island-in-the-sea yarns of Article 3, the luminance is remarkably improved. In particular, when the polycarbonate alloy (alloy) is used as the sea portion, it is possible to produce a birefringent island-in-the-sea yarn having the best optical modulation properties. In this case, the polycarbonate alloy is preferably made of polycarbonate and modified glycol polycyclohexylene dimethylene terephthalate (PCTG), and more preferably polycarbonate and modified glycol poly Cyclohexylene dimethylene terephthalate (PCTG) is a polycarbonate alloy consisting of a weight ratio of 15: 85 ~ 85: 15 is effective to increase the brightness. If the polycarbonate is added less than 15%, the viscosity of the polymer required to secure the radioactivity is high, and the ordinary spinning machine cannot be used. If the polycarbonate is more than 85%, the glass transition temperature increases, and after the nozzle discharge, the radiation tension increases to secure radioactivity. Has a difficult problem.

Most preferably, the polycarbonate and the modified glycol polycyclohexylene dimethylene terephthalate (PCTG) in a weight ratio of 4: 6 to 6: 4 exhibit the best effect on brightness enhancement. Furthermore, it is effective to improve the light modulation efficiency by selecting a material in which the refractive index in the two axial directions is substantially the same, but the difference in the refractive index in the one axial direction is large.

On the other hand, methods for changing an isotropic material to birefringence are commonly known and, for example, when drawn under suitable temperature conditions, the polymer molecules can be oriented so that the material becomes birefringent. The birefringent island-in-the-sea yarn of the present invention may be manufactured by a coextrusion method or the like, but is not limited thereto.

Therefore, if the conventional island-in-the-sea yarn utilizes the remaining island portion as a micro-fine fiber by eluting the sea portion regardless of whether it is birefringent or not to produce the microfiber yarn, in the present invention, the sea portion and island portion are not eluted. It is assumed that the island-in-the-sea yarn having different optical properties is used by itself. In the present invention, only the case where the island portion is composed of anisotropy and the sea portion is isotropic is assumed, but the object of the present invention may be achieved in the opposite case. .

As a result, in order to maximize the light modulation efficiency of the birefringent island-in-the-sea yarn as described above, the optical properties of the island portion and the sea portion should be different, and the area of the light modulation interface should be wide. For this purpose, the number of the drawing parts should be large, and preferably, the number of drawing parts should exceed 500. However, even when the refractive index of the island portion is anisotropic and the refractive index of the sea portion is arranged isotropically in the conventional islands and islands, when the number of the island portions exceeds 500, the island portion is agglomerated, and the area of the optical modulation interface is reduced and the light is reduced. There is a fatal problem of poor modulation efficiency. Accordingly, the birefringent island-in-the-sea yarn of the present invention can prevent the islands from clumping together. As a result, the optical modulation efficiency of the island-in-the-sea yarn is maximized, and when the birefringent island-in-the-sea yarn according to the embodiment of the present invention is added to the luminance-enhanced film and the luminance-enhanced film described below, a significant improvement in light modulation effect and luminance can be expected.

On the other hand, according to a preferred embodiment of the present invention, the luminance-enhanced film of the present invention may have a structured surface layer on its surface, and more specifically, the structured surface layer may be formed on the surface from which light is emitted. The structured surface layer may be prismatic, lenticular or convex. In detail, the surface on which the light on the luminance-enhanced film is emitted may have a curved surface having a convex lens shape. The curved surface may focus or defocus light transmitted through the surface. In addition, the light exit surface may have a prism pattern.

Next, the method of manufacturing the birefringent island-in-the-sea yarn of the present invention will be described. The birefringent island-in-the-sea yarn of the present invention can be applied without any limitation as long as it is a method capable of producing a conventional island-in-the-sea yarn such as a composite spinning process. The spinnerets and spinnerets used can be used as long as they can produce birefringent islands, but generally the spinnerets and yarns are designed to substantially match the arrangement of the islands in the cross-section of the birefringent islands. Can be used. Specifically, a sea component flowed from a flow channel designed to fill the gap between the island component extruded from a hollow pin or a spinning nozzle appropriately designed to allow the island portion to be partitioned inside the spinneret, and the flow of water Although it can be used without any limitation as long as the spinneret capable of forming the island-in-the-sea yarn by extruding from the discharge port while gradually thinning, the birefringent island-in-the-sea yarn of the present invention can be used, but preferably the sphere shown in FIG. It can be emitted through a spinneret including a gold platelet. Figure 6 is a cross-sectional view of the portion of the detentional portion plate for the island-in-the-sea yarn manufacturing according to an embodiment of the present invention specifically formed in the center and radially around the core portion 121, the core portion 121 to prevent the conduction And a plurality of island component supply paths 122 formed along the outer circumference of the island component supply parts 123 and 124 and the island component supply parts 123 and 124 formed therein, and including a plurality of sea component supply paths. It is designed to include a plurality of sea component supply unit 125, Korean Patent Application No. 10-2010-0027670 for this is inserted as a reference. On the other hand, the spinneret for spinning the birefringent island-in-the-sea yarn of the present invention may include the above-described preferred spherical partial plate, it can be used in various combinations according to the shape and specifications of the desired island-in-the-sea yarn. For example, the discharge port, which is a portion where the depressed upper part plate of the present invention is placed on the upper part and the actual sea island is discharged, may be configured in the shape of a funnel. Meanwhile, as shown in FIG. 5, the lower plate 130 may include flow paths 52 and 53 for allowing polymers supplied from each island component supply unit and sea component supply unit to flow toward one discharge port 131. Can be. In this case, the flow paths 132 and 133 may be designed in various numbers and shapes according to the arrangement of the spinneret, and the discharge hole 131 may be formed in an area where the flow path and the flow path intersect.

Furthermore, in order to facilitate the distribution and mixing of island components and sea components in addition to the detention part partial plate of the present invention, forming a spinneret by providing a separate distribution plate with an appropriate number on the upper part and / or the lower part part of the depart part distribution plate. It is possible.

Next, a method of manufacturing the luminance-enhanced film of the present invention will be described. First, after weaving a fabric including a birefringent island-in-the-sea yarn having the above-described configuration, the fabric may be placed between the substrate and the substrate, and then laminated. The substrate usable at this time may preferably have a three-layer structure of a skin layer / core layer / skin layer. After the lamination process, the skin layer (A1) / core layer (B) / skin layer (A2) / fabric layer (C) / skin layer (A3) / core layer (B2) / skin layer (A4) A layer may be formed, and as described above, all or part of these parts may be melted if the sea layers of the birefringent islands and the fibers have the same melting temperature as the skin layers A2 and A3 corresponding to the fabric layer. At this time, the lamination process may be performed in a roll-to-roll, hot press, etc., but preferably carried out in a vacuum hot press is effective in preventing the generation of bubbles to improve the adhesion and brightness. In this case, the degree of vacuum in the pressurizing and heating steps is 5 to 500 torr, the applied pressure is 1.0 to 100 kgf / cm ² and the process time is preferably 1 to 30 minutes. As described above, the lamination temperature may be appropriately selected and applied at a temperature between the melting start temperature of the island portion of the birefringent island-in-the-sea yarn and the melting temperature of the fiber and / or sea portion. On the other hand, when the vacuum degree is less than 5 torr, there is a fear that the process efficiency is lowered, and when it exceeds 500 torr, there is a fear that bubble removal is insufficient. In addition, the applied pressure is 1.0kgf / cm ² Less than When the adhesion of the film may not be sufficient and when it exceeds 100 kgf / cm ² , the pressure may be excessive to disturb the tissue of the fabric and collapse the arrangement of the fibers. If the process time is less than 1 minute, bubble removal and adhesion may be insufficient, and if it exceeds 30 minutes, it is not preferable in terms of process efficiency.

The luminance-enhanced film of the present invention can be widely used in flat panel display technologies such as liquid crystal displays, LED TVs, projection displays, plasma displays, field emission displays and electroluminescent displays.

Hereinafter, the present invention will be described in detail by Examples and Experimental Examples. The following Examples and Experimental Examples are only illustrative of the present invention, and the scope of the present invention is not limited to the following Examples and Experimental Examples.

≪ Example 1 >

Isotropic PC alloy containing polycarbonate and modified glycol polycyclohexylene dimethylene terephthalate (PCTG) in a 5: 5 solution (nx = 1.57, ny = 1.57, nz = 1.57, melting temperature: 145 ° C) , Anisotropic PEN (nx = 1.88, ny = 1.57, nz = 1.57, melting start temperature: 262 ° C.). In order to obtain a birefringent island-in-the-sea yarn of the same cross-section as shown in FIG. 3, the composition is injected into a spinneret including a portion of the upper portion of the depressor plate (12 outlets) corresponding to FIG. 6 and a lower plate (1 outlet) of FIG. 7. Birefringent island-in-the-sea yarn (mono sand, island component number: 25040, diameter: 66.5 mu m) was prepared. At this time, POY (partial alignment yarn) 85/1 having a spinning speed of 2500MPM was prepared, and the FY 40/1 was prepared by performing 2.1 times stretching at a temperature of 140 degrees.

The prepared birefringent island-in-the-sea yarn (monosa) was inclined (40de / 1fila), and the isotropic PC alloy fiber (melting temperature: 145 ° C) having the same composition as the sea component was used as the weft yarn (POY 60/24). Weaving with fabric.

FIG. 5 is an SEM photograph of the surface of the fabric prepared in Example 1. FIG. It can be seen from the photograph that the trimming does not occur in the birefringent islands used as a slope.

Comparative Example 1

Isotropic PC alloy containing polycarbonate and modified glycol polycyclohexylene dimethylene terephthalate (PCTG) in a 5: 5 solution (nx = 1.57, ny = 1.57, nz = 1.57, melting temperature: 145 ° C) , Anisotropic PEN (nx = 1.88, ny = 1.57, nz = 1.57, melting start temperature: 262 ° C.).

In order to obtain a birefringent island-in-the-sea yarn having a cross-section as shown in FIG. 2A, the composition is injected into a spinneret including the spherical partial plate as shown in FIG. 2 corresponding to FIG. 2A, and the birefringent island-in-the-sea yarn having a cross-section of FIG. 2A (monosa, The number of island components: 1016, the diameter: 19㎛) was prepared. POY 85/12 was prepared at a spinning speed of 2500 MPM and a spinning temperature of 290 degrees, followed by 2.1 times stretching at 140 degrees to produce FY 40/12. The two islands of the island-in-the-sea yarn FY 40/12 were braided (80de / 24fila) and then inclined, and woven into a fabric using an isotropic PC alloy fiber (melting temperature: 145 ° C.), the same as that of the sea component.

Figure 2c is a SEM photograph of the surface of the fabric prepared through Comparative Example 1. Through the above picture, it can be seen that the trimming occurred in the birefringent islands used as a slope.

Since the luminance-enhanced film of the present invention has excellent optical modulation performance, it can be widely used in optical devices such as cameras and liquid crystal display devices requiring high brightness such as mobile phones, LCDs, LED TVs, and the like.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical spirit of the present invention, and such modifications and modifications belong to the appended claims. .

60 fabric 61 slope
62: weft

Claims (42)

materials;
A birefringent island-in-the-sea yarn is included in the substrate to generate a light modulation effect, and the birefringent island-in-the-sea yarn has a core portion for preventing the joining therein and a plurality of island component groups radially formed around the core portion. Luminance-enhanced film containing but not including birefringent islands. The method of claim 1,
The island component per unit area of the inner group (㎛ ²⁾ island component per unit area formed on a boundary between the groups adjacent than the number of island component (㎛ ²⁾ the number of the island component is formed with a small border the island component group adjacent by the interface portion Brightness enhancement film, characterized in that partitioned. The method of claim 2,
The boundary portion is luminance-enhanced film, characterized in that formed in the radial centered on the core. The method of claim 1,
The island component per unit area of the inner group (㎛ ²⁾ per unit area than the number of the core portion of the island component (㎛ ²⁾ brightness enhancement film characterized in that a small number of the island component. The method of claim 4, wherein
The island component per unit area of the inner group (㎛ ²⁾ per unit area than the number of the core portion of the island component (㎛ ²⁾ Number of island component a brightness enhancement film, characterized in that not more than one-half or one-third of. The method of claim 3,
Brightness-enhanced film, characterized in that one or more annular boundary portion is formed around the core portion. The method of claim 1,
The cross-sectional shape of the island component group is a luminance-enhanced film, characterized in that the sector, isosceles triangle or equilateral trapezoid. The method of claim 1,
The brightness enhancing film, characterized in that the number of the plurality of island component groups 10 to 50. The method of claim 8,
The luminance-enhanced film, characterized in that the number of island components contained in one island component group is 800 ~ 2000. The method of claim 1,
The luminance-enhanced film, characterized in that the total number of islands contained in the birefringent island-in-the-sea yarn is 20000 ~ 30000. The method of claim 2,
The island component per unit area of the inner group (㎛ ²⁾ per unit area than the number of boundary unit of the island component (㎛ ²⁾ Number of island component is 3/4 or brightness enhancement film is not more than 1/2, characterized in. The method of claim 1,
The birefringent island-in-the-sea yarn is a luminance-enhanced film, characterized in that the A value of the relation 1 below.
[Relationship 1]
A = number of strands / strands of mono yarn The method of claim 1,
The birefringent island-in-the-sea yarn is woven in the form of a fabric, wherein one of the weft or warp of the fabric is a birefringent island-in-the-sea yarn and the other is a brightness-enhanced film. The method of claim 13,
The melt-starting temperature of the island component of the birefringent island-in-the-sea yarn is higher than the melting temperature of the fiber. The method of claim 13,
The birefringent island-in-the-sea yarn is luminance-enhanced film characterized in that it is woven into mono yarns. The method of claim 1,
And a birefringence interface is formed at a boundary between the island component and the sea portion of the birefringent island-in-the-sea yarn. The method of claim 13,
The fiber is a brightness-enhanced film, characterized in that the optical properties are isotropic fibers. The method of claim 13,
Said fiber is any one or more fibers selected from the group consisting of polymer fibers, natural fibers and inorganic fibers. The luminance-enhanced film of claim 13, wherein a melting start temperature of the island component of the birefringent island-in-the-sea yarn is higher than a melting temperature of the sea portion. The luminance-enhanced film of claim 13, wherein a melting start temperature of the island component of the birefringent island-in-the-sea yarn is 30 ° C or more higher than a melting temperature of the fiber. The luminance-enhanced film of claim 13, wherein a melting start temperature of the island component of the birefringent island-in-the-sea yarn is 30 ° C or more higher than a melting temperature of the sea portion. The method of claim 13,
The fiber is a luminance-enhanced film, characterized in that some or all of the melted. The method of claim 13,
Part or all of the sea portion of the birefringent island-in-the-sea yarn is melt-enhanced film. The method of claim 13,
Luminance-enhanced film, characterized in that the sea portion of the fiber and the birefringent island-in-the-sea yarn is the same component. The luminance-enhanced film of claim 13, wherein the optical property of the island component is birefringent, and the optical property of the sea portion is isotropic. The luminance-enhanced film of claim 1, wherein the refractive index of the substrate and the birefringent island-in-the-sea yarn is 0.05 or less in two axial directions, and the difference in refractive index in one remaining axial direction is 0.1 or more. . 2. The substrate according to claim 1, wherein when the refractive index in the x-axis direction of the substrate is nX1, the refractive index in the y-axis direction is nY1, the refractive index in the z-axis direction is nZ1, and the refractive indices of the birefringent island-in-the-sea yarns are nX2, nY2 and nZ2. A luminance-enhanced film, characterized in that at least one of the refractive indexes of the X, Y, and Z axes of the birefringent island-in-the-sea yarns coincides. The method of claim 1, wherein the refractive index of the sea portion and the island component of the birefringent island-in-the-sea yarn has a difference in refractive index of 0.05 or less in two axial directions, the difference in refractive index of the other one axial direction is 0.1 or more Reinforced film. 27. The refractive index of the birefringent island-in-the-sea yarn of the island component is nX3, the refractive index in the y-axis direction is nX3, the refractive index in the y-axis direction is nY3, and the refractive index in the z-axis direction is nZ3. When the refractive index of the nX4, y-axis direction is nY4 and the refractive index of the z-axis direction is nZ4, at least any one of the X, Y, Z-axis refractive index of the base material and the birefringent island-in-the-sea yarn coincides. 30. The luminance-enhanced film of claim 29, wherein an absolute value of a difference between refractive indexes of nX3 and nX4 is 0.1 or more. The method of claim 1,
The diameter of the birefringent island-in-the-sea yarn is luminance-enhanced film, characterized in that 10 ~ 100㎛. A birefringent island-in-the-sea yarn comprising a core portion for preventing conduction to the inside of the island-in-the-sea yarn and a plurality of island component groups radially formed around the core portion. 33. The method of claim 32,
The island component per unit area of the inner group (㎛ ²⁾ island component per unit area formed on a boundary between the groups adjacent than the number of island component (㎛ ²⁾ the number of the island component is formed with a small border the island component group adjacent by the interface portion The birefringent islands characterized in that the compartment. The method of claim 33, wherein
The boundary portion is birefringent islands characterized in that the radially formed around the core portion. The method of claim 33, wherein
Use may be birefringent as the island component per unit area of the inner group (㎛ ²⁾ it characterized in that the number of island component count per area unit than the core portion (㎛ ²⁾ of the island component is small. The method of claim 33, wherein
And at least one annular boundary portion formed around the core portion. The method of claim 33, wherein
The cross-sectional shape of the island component group is a birefringent islands characterized in that the sector, isosceles triangle or equilateral trapezoid. The method of claim 33, wherein
The number of the plurality of island component groups is birefringent islands, characterized in that 10 to 50. The method of claim 33, wherein
Birefringent islands characterized in that the number of islands contained within one island component group is 800 ~ 2000. The method of claim 33, wherein
The birefringent island-in-the-sea yarn is characterized in that the total number of islands contained in the birefringent island-in-the-sea yarn is 20000 ~ 30000. 36. The method of claim 35,
Use may be birefringent, it characterized in that the island component groups, the number per unit area of the inner (㎛ ²⁾ per unit area than the number of island component core portion unit (㎛ ²⁾ of the island component in the 1/2 or 1/3 or less. The method of claim 33, wherein
If birefringence is to use the number of the island component per unit area of the inner group (㎛ ²⁾ per unit area of the boundary than the number of island component (㎛ ²⁾ island component wherein not more than 3/4 or 1/2.

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