KR20150079170A - Reflective polizer having random dispersion type - Google Patents

Abstract

A reflective polarizer of the present invention improves bright line seeing phenomenon, has wide optical viewing angle, minimizes optical loss, and maximizes brightness improvement compared to an existing dispersion type reflective polarizer. When implementing the reflective polarizer, a group dispersion can be formed with simple control. Accordingly, productivity improvement can be maximized through process simplification.

Description

[0001] The present invention relates to a randomly dispersed reflective polarizer,

Disclosed herein is a randomly distributed reflective polarizer, and more particularly, to a randomly dispersed reflective polarizer capable of maximizing luminance improvement while minimizing optical loss.

Flat panel display technology is mainly composed of liquid crystal display (LCD), projection display, and plasma display (PDP), which have already secured a market in the TV field. In addition, field emission display (FED) and electroluminescence display (ELD) And it is expected to occupy the field according to each characteristic. Liquid crystal displays are currently being used in a wide range of applications such as notebook computers, personal computer monitors, liquid crystal TVs, automobiles, and aircrafts, accounting for 80% of the flat panel market, and booming demand for LCDs worldwide.

Conventional liquid crystal displays place a liquid crystal and an electrode matrix between a pair of light absorbing optical films. In liquid crystal displays, the liquid crystal portion has an optical state that changes accordingly by moving the liquid crystal portion by an electric field generated by applying a voltage to the two electrodes. This process displays an image by using a polarized light in a specific direction as a 'pixel' containing information. For this reason, liquid crystal displays include a front optical film and a rear optical film that induce polarization.

The optical film used in such a liquid crystal display does not necessarily have a high utilization efficiency of light emitted from the backlight. This is because 50% or more of the light emitted from the backlight is absorbed by the back side optical film (absorption type polarizing film). Therefore, in order to improve the utilization efficiency of the backlight in the liquid crystal display, a reflection type polarizer is provided between the optical cavity and the liquid crystal assembly.

1 is a view showing the optical principle of a conventional reflective polarizer. Specifically, the P polarized light from the optical cavity toward the liquid crystal assembly is transmitted through the reflective polarizer to the liquid crystal assembly. The S polarized light is reflected from the reflective polarizer into the optical cavity, Direction is reflected in a randomized state and is then transmitted to the reflective polarizer so that the S polarized light is converted into P polarized light that can pass through the polarizer of the liquid crystal assembly and is transmitted to the liquid crystal assembly after passing through the reflective polarizer.

The selective reflection of the S polarized light and the transmission of the P polarized light with respect to the incident light of the reflective polarizer are performed in such a manner that the refractive index of each optical layer in the state of alternately stacking the flat optical layer having the anisotropic refractive index and the flat optical layer having the isotropic refractive index The optical thickness of each of the optical layers in accordance with the difference and the elongation process of the laminated optical layer, and the change of the refractive index of the optical layer.

That is, the light incident on the reflective polarizer repeats the reflection of the S polarized light and the transmission of the P polarized light while passing through each optical layer, and finally, only the P polarized light of the incident polarized light is transmitted to the liquid crystal assembly. On the other hand, as described above, the reflected S polarized light is reflected in the polarization state of the diffused reflection plane of the optical cavity in a randomized state and then transmitted to the reflective polarizer. As a result, it is possible to reduce the waste of power with loss of light generated from the light source.

However, such a conventional reflective polarizer has a structure in which an isotropic optical layer and an anisotropic optical layer having different refractive indexes are alternately stacked and subjected to an elongation treatment, whereby the optical thickness and refractive index of each optical layer, which can be optimized for selective reflection and transmission of incident polarized light, The manufacturing process of the reflection type polarizer is complicated. In particular, since each optical layer of the reflective polarizer has a flat plate structure, the P polarized light and the S polarized light must be separated in accordance with a wide incident angle range of incident polarized light, so that the number of layers of the optical layer is excessively increased and the production cost exponentially There was an increasing problem. Further, there is a problem that optical performance is deteriorated due to optical loss due to the structure in which the number of layers of the optical layer is excessively formed.

2 is a cross-sectional view of a conventional multilayer reflective polarizer (DBEF). Specifically, in the multilayer reflective polarizer, skin layers 9 and 10 are formed on both sides of the base material 8. The substrate 8 is divided into four groups (1, 2, 3, 4), in which each of the isotropic layers and the anisotropic layers are alternately stacked to form about 200 layers. Separate bonding layers 5, 6 and 7 are formed between the four groups 1, 2, 3 and 4 forming the substrate 8, respectively. In addition, since each group has a very thin thickness of about 200 layers, these groups often contain a protective layer (PBL) since individual groups can be damaged if they are individually pneumatically shipped. In this case, there is a problem that the thickness of the base material becomes thick and the production cost rises. In addition, since the reflective polarizer included in the display panel has a limitation on the thickness of the substrate in order to make it slim, when the adhesive layer is formed on the substrate and / or the skin layer, the substrate is reduced by the thickness thereof, there was. Furthermore, since the inside of the substrate and the substrate and the skin layer are bonded with the adhesive layer, there is a problem that when the external force is applied, the elapsed time elapses, or the storage place is poor, delamination occurs. In addition, not only the defect rate is excessively increased in the process of adhering the adhesive layer, but also the destructive interference to the light source occurs due to the formation of the adhesive layer.

Skin layers 9 and 10 are formed on both sides of the base material 8 and separate adhesive layers 11 and 12 are formed between the base material 8 and the skin layers 9 and 10 for bonding them. When the conventional skin layer of polycarbonate and PEN-coPEN are integrated through co-extrusion with a substrate laminated alternately, peeling may occur due to the compatibility member and the birefringence to the elongation axis during the stretching process due to the crystallization degree of about 15% There is a high risk of occurrence. Accordingly, in order to apply the polycarbonate sheet of the non-smelting process, an adhesive layer has to be formed. As a result, the yield decreases due to external foreign matters and process defects due to the addition of the adhesive layer process. Generally, in producing a polycarbonate-free sheet of the skin layer, birefringence occurs due to uneven shear pressure due to the winding process, It is necessary to control the molecular structure of the polymer and speed control of the extrusion line in order to compensate for the deterioration of productivity.

The method of producing the conventional multilayer reflective polarizer described above will be briefly described. After four co-extruded groups having different average optical thicknesses forming the substrate are separately co-extruded, the four co-extruded four groups are stretched, Four groups are adhered with an adhesive to prepare a substrate. This is because when the base material is stretched after the adhesive is adhered, the peeling phenomenon occurs. Thereafter, the skin layer is adhered to both surfaces of the substrate. As a result, in order to construct a multi-layer structure, a two-layer structure is folded to form a four-layer structure, and a group (209-layer) is formed through a process of forming a multi-layer structure in a continuous folding manner. It was difficult to form a group in the multilayer in the process. As a result, four groups having different average optical thicknesses have to be separately co-extruded and bonded.

Since the above-described process is intermittently performed, a remarkable increase in the manufacturing cost has been brought about. As a result, the cost of all the optical films included in the backlight unit is the most expensive. As a result, there has been a serious problem that liquid crystal displays other than the reflective polarizer are frequently released even when the decrease in luminance is reduced in terms of cost reduction.

Thus, there has been proposed a reflective polarizer in which a birefringent polymer stretched in the longitudinal direction is arranged in a substrate, not a multilayer reflective polarizer, and a dispersion capable of achieving the function of the reflective polarizer is dispersed. 3 is a perspective view of a reflective polarizer 20 including a rod-shaped polymer, in which birefringent polymers 22 stretched in the longitudinal direction are arranged in one direction inside the base material 21. Fig. The birefringent interface between the base material 21 and the birefringent polymer 22 causes a light modulation effect to perform the function of the reflection type polarizer. However, as compared with the above-mentioned alternately stacked reflective polarizer, it is difficult to reflect light in the entire wavelength range of visible light, resulting in a problem that the light modulation efficiency is too low. Accordingly, in order to have a transmittance and a reflectance similar to those of the alternately stacked reflective polarizer, an excessively large number of birefringent polymers 22 must be disposed inside the substrate. Specifically, in order to have optical properties similar to those of the above-described laminate-type reflective polarizer in the substrate 21 having a width of 1580 mm and a height (thickness) of 400 μm or less when a horizontal 32-inch display panel is manufactured on the basis of the vertical cross section of the reflective polarizer, At least 100% of circular or elliptical birefringent polymer 22 having a cross-sectional diameter in the longitudinal direction of 0.1 to 0.3 탆 must be contained. In this case, not only the production cost is excessively increased but also the facilities are excessively complicated, There is a problem that it is difficult to produce the facility itself and thus it is difficult to commercialize it. Further, since it is difficult to make various optical thicknesses of the birefringent polymer 22 contained in the sheet, it is difficult to reflect light in the entire visible light region, and there is a problem that the physical properties are reduced.

In order to overcome this problem, a technical idea including a birefringent sea chart was proposed in the substrate. FIG. 4 is a cross-sectional view of a birefringent chart paper included in the inside of the base material. The birefringent chart paper can generate a light modulation effect at the light modulation interface of the internal part and the dissolution part, The optical properties can be achieved without arranging chart marks. However, since the fiber is a birefringent graphite sheet, compatibility with a base material such as a polymer, ease of handling, and adhesiveness have been encountered. Furthermore, the light-scattering is induced by the circular shape, and the reflection polarizing efficiency against the light wavelength in the visible light region is lowered. As a result, the polarizing characteristic is lowered compared with the existing product and the luminance improvement is limited. In addition, As the area is subdivided, due to the occurrence of pores, light leakage, that is, light loss phenomenon, has been caused. In addition, due to the structure of the fabric in the form of a structure, there is a problem that limitations are imposed on improvement of reflection and polarization characteristics due to limitations of the layer structure. Also, in the case of the dispersion type reflective polarizer, the problem of the appearance of the bright line appears due to the space between the layers and the space between the dispersion bodies.

Disclosure of the Invention The present invention has been conceived to solve the above-mentioned problems, and it is an object of the present invention to provide a dispersion type polarizing element capable of maximizing brightness enhancement while minimizing light loss, To provide a reflective polarizer.

In order to solve the above-mentioned problem, in order to transmit a first polarized light to be externally irradiated and to reflect a second polarized light, a plurality of dispersing bodies are contained in the substrate, and the plurality of dispersing bodies are arranged in at least one axial direction Wherein at least 80% of the plurality of dispersions contained in the base material have different refractive indices and the aspect ratio of the minor axis length to the major axis length is 1/2 or less and the aspect ratio is 1/2 or less dispersions are a group includes more than two different cross-sectional area, the cross-sectional area of the first group is 0.2 ~ 2.0㎛ ^2, and the cross-sectional area of the second group is at most ² from 5.0㎛ 2.0㎛ ^2, greater than the cross-sectional area of the third group 5.0㎛ 10.0㎛ ² and ² from below, greater than the first group of the dispersion, a second group of the dispersion and the dispersion of the third group are randomly arranged core layer; And an integrated skin layer formed on at least one side of the core layer.

According to a preferred embodiment of the present invention, the number of dispersions of the third group among the dispersions having the aspect ratio of 1/2 or less may be 10% or more.

According to another preferred embodiment of the present invention, the number of the first groups in the dispersion having the aspect ratio of 1/2 or less may be 30 to 50%, the number of the third groups may be 10 to 30% Is the number of dispersions of the first group / the number of dispersions of the third group is 3 to 5 days.

According to another preferred embodiment of the present invention, the number of the second group of the dispersions having the aspect ratio of 1/2 or less may be 25 to 45%.

According to another preferred embodiment of the present invention, the refractive index of the base material and the dispersion body may be 0.05 or less in refractive index with respect to the two axial directions, and the difference in refractive index with respect to the remaining one axial direction may be 0.1 or more.

According to another preferred embodiment of the present invention, the reflection type polarizer may be at least one stretched in the axial direction.

According to another preferred embodiment of the present invention, a structured surface layer formed on at least one side of the substrate may be included.

According to another preferred embodiment of the present invention, a primer layer for enhancing adhesion between the skin layer and the structured surface layer may be further included.

According to another preferred embodiment of the present invention, the structured surface layer may be a fine patterned layer.

According to another preferred embodiment of the present invention, the fine pattern may be at least one selected from the group consisting of a prism, a lenticular, a microlens, a triangular pyramid, and a pyramid pattern.

According to another preferred embodiment of the present invention, there is provided a polarizing plate comprising: (1) a plurality of dispersing bodies in a substrate for transmitting a first polarized light irradiated from the outside and reflecting the second polarized light, Wherein at least 80% of the plurality of dispersions contained in the substrate have an aspect ratio of a minor axis length to a major axis length of 1/2 or less with respect to a vertical cross section in the longitudinal direction, and the aspect ratio is not more than half the dispersion comprise at least three groups are different from the cross-sectional area, the cross-sectional area of the first group ² 0.2 ~ 2.0㎛, the cross-sectional area of the second group is less than a ^second 5.0㎛ ² from 2.0㎛ , and the third group of cross-sectional area is less than ² 5.0㎛ 10.0㎛ ² from the first group of the dispersion, the dispersion of the second element group and the third group distributed randomly arranged in the core layer of the body; And an integrated skin layer formed on at least one side of the core layer to produce a randomly dispersed reflective polarizer.

According to another preferred embodiment of the present invention, a step of forming a primer layer for enhancing adhesion between the skin layer and the structured surface layer may be further included between steps (1) and (2).

According to another preferred embodiment of the present invention, the structured surface layer may be a fine patterned layer, and more preferably, the fine pattern is formed of a material selected from the group consisting of prism, lenticular, microlens, triangular pyramid and pyramid pattern It can be more than one.

According to another preferred embodiment of the present invention, the structured surface layer may be a fine patterned layer, and more preferably, the fine pattern is formed of a material selected from the group consisting of prism, lenticular, microlens, triangular pyramid and pyramid pattern It can be more than one.

According to another preferred embodiment of the present invention, the step (2) may be performed through a mold film for pattern formation.

According to another preferred embodiment of the present invention, the step (2) includes the steps of: a) transferring the reflective polarizer; b) transferring the mold film for pattern formation formed on one surface of the reversed phase pattern of the structured surface layer; c) bringing the one surface of the pattern-forming mold film into contact with the reflective polarizer; d) filling fluid between the patterns by injecting a fluid material into a region where the reflective polarizer and the mold film for pattern formation are in close contact with each other; e) applying the material to the reflective polarizer by curing the material filled between the patterns; And f) separating the mold film for pattern formation and the reflective polarizer coated with the material, wherein the steps a) and b) may be performed in any order.

According to still another preferred embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: (a) applying pressure to the skin layer and the mold film adhering to each other between steps (d) .

According to another preferred embodiment of the present invention, the step e) may include irradiating heat or UV to the material filled between the patterns.

According to another preferred embodiment of the present invention, the step (2) comprises the steps of: i) closely feeding a reflective polarizer to a master roll formed on one side of a reverse-phase pattern of the structured surface layer, Or applying the molten polymer resin to the reflective polarizer; And ii) UV-curing the polymer resin by irradiating UV or heat while the polymer resin is press-formed on the pattern surface of the master roll, and separating the polymer resin.

According to another preferred embodiment of the present invention, the polymer resin may be secondarily cured by irradiating UV or heat again after the step ii).

According to another preferred embodiment of the present invention, the substrate is made of polyethylene naphthalate (PEN), copolyethylene naphthalate (co-PEN), polyethylene terephthalate (PET), polycarbonate (PC), polycarbonate (PS), 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 blend (SAN), ethylene vinyl acetate (EVA), polyamide (PA), polyacetal , Epoxies (EP), urea (UF), melamine (MF), unsaturated polyesters (UP), silicones (SI), elastomers and cycloolefin polymers.

According to another preferred embodiment of the present invention, the dispersion may be formed of at least one selected from the group consisting of polyethylene naphthalate (PEN), copolyethylene naphthalate (co-PEN), polyethylene terephthalate (PET), polycarbonate (PC) (PS), heat resistant polystyrene (PS), polymethyl methacrylate (PMMA), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PE), acrylonitrile butadiene styrene (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile (SAN), ethylene vinyl acetate (EVA), polyamide (PA) , Phenol, epoxy (EP), urea (UF), melamine (MF), unsaturated polyester (UP), silicone (SI), elastomers and cycloolefin polymers.

According to another preferred embodiment of the present invention, the refractive index difference between the substrate and the dispersion body may be larger than the difference between the refractive indexes in the elongated axial directions and the refractive indexes in the other axial directions.

According to another preferred embodiment of the present invention, the refractive index of the substrate and the dispersion body may be 0.05 or less in refractive index with respect to the two axial directions, and the difference in refractive index with respect to the remaining one axial direction may be 0.1 or more.

According to another preferred embodiment of the present invention, the dispersion may be elongated in the longitudinal direction.

According to another preferred embodiment of the present invention, a birefringence interface may be formed between the dispersion and the substrate.

According to another preferred embodiment of the present invention, the dispersion has optical birefringence, and the substrate may be optically isotropic.

Hereinafter, terms used in this specification will be briefly described.

'Dispersion has birefringence' means that when the light is irradiated to fibers having different refractive indexes along the direction, the light incident on the dispersion is refracted into two lights having different directions.

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

'Anisotropy' means that the optical properties of an object are different according to the direction of light, and anisotropic objects have birefringence and correspond to isotropy.

'Light modulation' means that the irradiated light reflects, refracts, scatters, changes the intensity of the light, the period of the wave or the nature of the light.

'Aspect ratio' means the ratio of the short axis length to the long axis length based on the vertical cross section in the longitudinal direction of the dispersion.

The reflective polarizer of the present invention has a wider line viewing angle and a wider viewing angle than the conventional dispersion type reflective polarizer, maximizing the luminance improvement while minimizing the light loss, maximizing the luminance improvement while maximizing the wide viewing angle and minimizing the light loss .

In addition, it is possible to form a group dispersion body by simple control in the implementation of a reflective polarizer, thereby maximizing the productivity improvement by simplifying the process.

1 is a schematic view for explaining the principle of a conventional reflective polarizer.
2 is a cross-sectional view of a currently used multi-layer reflective polarizer (DBEF).
3 is a perspective view of a reflection type polarizer including a bar-shaped polymer.
4 is a cross-sectional view showing a path of light incident on a birefringent chart used for a reflection type polarizer.
5 is a cross-sectional view of a random reflective polarizer according to an embodiment of the present invention.
6 is a perspective view of a random reflective polarizer according to an embodiment of the present invention.
7 is a cross-sectional view of a dispersion according to a preferred embodiment of the present invention.
FIG. 8 is a perspective view of a reflective polarizer in which a lenticular pattern is regularly formed according to a preferred embodiment of the present invention, and FIG. 9 is a perspective view of a reflective polarizer in which a lenticular pattern is irregularly formed.
FIG. 10 is a perspective view of a reflective polarizer in which microlenses are regularly formed according to a preferred embodiment of the present invention, and FIG. 11 is a perspective view of a reflective polarizer in which microlenses are irregularly formed.
FIG. 12 is a perspective view of a reflective polarizer in which a prism pattern is regularly formed according to a preferred embodiment of the present invention, and FIG. 13 is a perspective view of a reflective polarizer in which a prism pattern is irregularly formed.
Figure 14 is a cross-sectional view of a coat-hanger die in accordance with a preferred embodiment of the present invention, and Figure 15 is a side view.
FIG. 16 is a schematic view of a process of forming a fine pattern according to an embodiment of the present invention, and FIG. 17 is a cross-sectional view showing a detailed structure of the forming unit of FIG.
18 is a schematic view of a process of forming a fine pattern according to a preferred embodiment of the present invention.
19 is a schematic view of a process of forming a fine pattern according to a preferred embodiment of the present invention.
20 is an exploded perspective view of a reflective polarizer in which a dispersion containing a reflective polarizer of the present invention is dispersed according to another preferred embodiment of the present invention.

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

The randomly scattering type reflective polarizer of the present invention includes a plurality of dispersing bodies in a substrate for transmitting a first polarized light radiated from the outside and reflecting the second polarized light, Wherein at least 80% of the plurality of dispersions contained in the base material have different refractive indexes in the axial direction of the substrate and the aspect ratio of the minor axis length to the major axis length is 1/2 or less with respect to the vertical cross section in the longitudinal direction, cross-sectional area of 1/2 or less the dispersion comprise at least three groups are cross-sectional area different from the first group is 0.2 ~ 2.0㎛ ^2, and the cross-sectional area of the second group is at most ² from 5.0㎛ 2.0㎛ ^2, greater than 3 and from the cross-sectional area of the ^second group is greater than 5.0㎛ 10.0㎛ ² or less, dispersion of the first group, second group and third group of dispersion of the dispersion is randomly arranged core layer; And an integrated skin layer formed on at least one side of the core layer. As a result, it is possible to maximize the brightness enhancement while minimizing the light loss and wide viewing angle while improving the bright line visibility compared to the conventional dispersive reflective polarizer.

5 is a cross-sectional view of a reflective polarizer in which a dispersion body is randomly dispersed in a substrate according to a preferred embodiment of the present invention. And a skin layer 207 integrally formed on at least one surface of the core layer. The skin layer 207 may be formed by a plurality of dispersions 201 to 206 randomly dispersed in the substrate 200.

First, the core layer will be described. In the core layer, at least 80% of the plurality of dispersions contained in the substrate should have an aspect ratio of the short axis length to the major axis length of 1/2 or less, more preferably 90% or more based on the vertical cross section in the longitudinal direction, The aspect ratio value should be 1/2 or less. Fig. 7 is a vertical section of the dispersion in the longitudinal direction of the dispersion which can be used in the present invention. The ratio of the relative length of the major axis length a to the minor axis length b (aspect ratio ) Should be less than 1/2. In other words, when the major axis length (a) is 2, the minor axis length (b) should be less than or equal to 1, which is 1/2 thereof. If the dispersion having a ratio of the minor axis length to the major axis length of 1/2 is contained in an amount of 20% or more of the total dispersion, the desired optical properties are difficult to achieve.

The dispersion body having the aspect ratio of 1/2 or less includes three or more groups having different cross-sectional areas. Specifically, in FIG. 5, the first group of dispersions (201, 202) having the smallest cross-sectional area and the second group of dispersions (203, 204) having the medium cross- ) Are dispersed randomly. In this case, the cross-sectional area of the first group is 0.2 ~ 2.0㎛ ^2, and the cross-sectional area of the second group is ² or less from 5.0㎛ 2.0㎛ ^2, greater than the cross-sectional area of the third group is less than ² from 10.0㎛ 5.0㎛ than ^2, the The dispersoids of the first group, the dispersant of the second group and the dispersant of the third group are randomly arranged. If the dispersion of any one of the first to third groups of dispersions is not included, desired optical properties are difficult to achieve (see Table 1).

In this case, preferably, the number of dispersions of the third group among the dispersions having the aspect ratio of 1/2 or less may be 10% or more. If it is less than 10%, improvement in optical properties may be insufficient. More preferably, the number of dispersions corresponding to the first group of the dispersions having the aspect ratio of 1/2 or less is 30 to 50%, and the number of dispersions corresponding to the third group is 10 to 30% This can improve optical properties (see Table 1)

On the other hand, more preferably, when the number of dispersants of the first group / the number of dispersants of the third group is 3 to 5, it may be very advantageous to maximize optical properties (see Table 1)

Preferably, the number of dispersions corresponding to the second group among the dispersions having the aspect ratio of 1/2 or less can satisfy 25 to 45%. Also, the dispersions which are out of the range of the cross-sectional areas of the first to third dispersions may be contained in the dispersion in which the aspect ratio is 1/2 or less.

As a result, it is possible to maximize the luminance improvement while maximizing the wide viewing angle and maximizing the luminance improvement while minimizing the light loss, while minimizing the loss of light and minimizing the light loss, while improving the bright line visibility compared to the conventional dispersive reflective polarizer.

And is also integrally formed between the core layer and the skin layer 207. As a result, deterioration of optical properties due to the adhesive layer can be prevented, and more layers can be added to a limited thickness, so that optical properties can be remarkably improved. Further, since the skin layer is produced simultaneously with the core layer and then the stretching process is performed, unlike the conventional adhesion of the core layer after stretching to the unstretched skin layer, the skin layer of the present invention can be stretched in at least one axial direction. As a result, the surface hardness is improved as compared with the non-drawn skin layer, and the scratch resistance is improved and the heat resistance can be improved.

FIG. 6 is a perspective view of a reflective polarizer according to an exemplary embodiment of the present invention. Referring to FIG. 6, a plurality of random dispersive bodies 211 are extended in the longitudinal direction within a substrate 210, As shown in FIG. In this case, each of the random dispersions 211 can be elongated in various directions, but it is preferable to elongate them in parallel in any one direction, more preferably, elongate in a direction perpendicular to the light irradiated from the external light source Elongation parallel to the trunk is effective in maximizing the light modulation effect.

According to a preferred embodiment of the present invention, a birefringent interface may be formed between the dispersion (first component) contained in the substrate and the substrate (second component). Specifically, in a reflection type polarizing element including a dispersion in a substrate, the magnitude of the substantial coincidence or inconsistency of the refractive index along the X, Y and Z axes in space between the substrate and the dispersion body depends on the scattering of the polarized light along its axis . Generally, the scattering ability changes in proportion to the square of the refractive index mismatch. Thus, the greater the degree of discrepancy in refractive index along a particular axis, the more scattered light rays are polarized along that axis. Conversely, when the inconsistency along a particular axis is small, the polarized light rays along the axis are scattered to a lesser degree. When the refractive index of the substrate is substantially coincident with the refractive index of the dispersion along an axis, the incident light polarized by the electric field parallel to this axis is not scattered regardless of the size, shape and density of the dispersion, something to do. Also, when the refractive index along the axis is substantially coincident, the light rays pass through the object without being substantially scattered. More specifically, the first polarized light (P wave) is transmitted without being influenced by the birefringent interface formed at the interface between the substrate and the dispersion body, while the second polarized light (S wave) is transmitted through the birefringent Modulation of light is affected by the interface. As a result, the P wave is transmitted and the S wave is modulated by light such as scattering and reflection of light, resulting in separation of polarized light.

Therefore, since the base material and the dispersion body can form a birefringent interface to cause a light modulation effect, when the base material is optically isotropic, the dispersion material can have birefringence, and conversely, when the base material has optical birefringence The dispersion body may have optical isotropy. Specifically, when the refractive index in the x-axis direction of the dispersion 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 index of the base is nX2, nY2 and nZ2, Birefringence may occur. More preferably, at least one of the X, Y, and Z axis refractive indexes of the substrate and the dispersion body may be different, and more preferably, when the elongation axis is the X axis, the difference in refractive indexes in the Y axis and Z axis directions is not more than 0.05 , And the difference in refractive index with respect to the X-axis direction may be 0.1 or more. On the other hand, when the difference in the refractive index is 0.05 or less, it is interpreted as matching.

In the present invention, the thickness of the base layer may be 20-180 탆, but is not limited thereto, and the thickness of the skin layer may be 50-500 탆, but is not limited thereto. The number of the total dispersions may be 25,000,000 to 80,000,000 when the thickness of the substrate is 120 占 퐉 based on 32 inch, but is not limited thereto.

FIG. 6 is a perspective view of a reflective polarizer having a structured surface layer according to a preferred embodiment of the present invention, in which a plurality of dispersing members are elongated in the longitudinal direction, and they form a core layer. In this case, each of the dispersing bodies may be elongated in various directions, but it is preferable to elongate them in parallel in any one direction, more preferably in a direction perpendicular to the light irradiated from the external light source Elongation is effective in maximizing the light modulation effect. A primer layer (not shown) may be selectively formed on one surface of the skin layer 212. This makes it possible to improve the adhesion, appearance and electrophotographic characteristics of the structured surface layer. Examples of the material include, but are not limited to, acrylic, ester, and urethane. The primer layer can be formed thinner than the other layers, and the thickness of the primer layer can be adjusted to improve the light transmittance and reduce the reflectance.

The thickness of such a primer layer may be from 5 nm to 300 nm. If the thickness of the primer layer is less than 5 nm, the adhesion between the core layer and the structured surface layer may be insufficient. If the thickness of the primer layer exceeds 300 nm, unevenness or molecular aggregation may occur during primer treatment.

Meanwhile, the reflective polarizer of the present invention can form a structured surface layer on at least one surface to maximize the light collecting effect and prevent irregular reflection on the surface, thereby remarkably improving the brightness. The structured surface layer may be formed on the substrate or formed on the primer layer.

The structured surface layer that can be applied in the present invention is a structure capable of improving the light collecting effect, and may be a fine pattern layer. The fine patterns that can be applied in this case may be any one or more selected from the group consisting of prisms, lenticular, microlenses, triangular pyramid, and pyramid patterns, and each of them may be formed by forming a pattern alone or in combination.

In FIG. 8, the skin layer 212 and the lenticular pattern layer 213 are formed on one surface of the base layer of the reflective polarizer, and the height (a) of the lenticular may be 10 to 50 μm. If the height of the lenticular pattern is less than 10 mu m, it may be difficult to realize the pattern layer. If the height of the lenticular pattern is more than 50 mu m, the brightness may decrease due to an increase in the total reflection amount of light.

The pitch (b) of the lenticular may be 20 to 100 mu m. If the pitch of the lenticular pattern is less than 20 占 퐉, the convergence effect of the lens shape is somewhat deteriorated due to an increase in the valley portion of the film per unit area, and the limitation of the accuracy of shape processing and the pattern shape are too narrow, If the thickness exceeds 100 탆, the possibility of occurrence of moire between the pattern structure and the panel becomes very large.

On the other hand, when the short axis radius of the elliptical cross section is a and the long axis radius is b, the ratio of the major axis / minor axis (b / a) is 1.0 to 3.0 per lenticular lens. If the ratio of the major axis / minor axis (b / a) is out of the above-mentioned range, there may arise a problem that the luminance line concealing efficiency for the light passing through the birefringent polarizing layer is inferior.

Further, in defining the height h of the lenticular lens, the tangent angle alpha at both end points of the lower end of the lens must be between 30 and 80 degrees. At this time, if? Is less than 30 degrees, the luminance line concealment efficiency is lowered, and if it is larger than 80 degrees, there is a problem that lens pattern production becomes difficult. When the cross-sectional shape of the lenticular lens is triangular, it is preferable that the vertex angle &thetas; satisfies 90 to 120 degrees for the hue line concealment effect.

On the other hand, the lenticular shape may be formed as a pattern having the same height and pitch as shown in Fig. 8, or lenticular patterns having different heights and pitch as shown in Fig. 9 may be mixed.

FIG. 10 shows a microlens pattern layer formed on one surface of the reflective polarizer. Referring to FIG. 10, the microlens may have a height of 10 to 50 .mu.m. If the height of the microlens pattern is less than 10 mu m, the light collecting effect is somewhat deteriorated, and the pattern implementation may be difficult. When the height exceeds 50 mu m, the moiré phenomenon tends to occur and the pattern may appear in the image.

Further, the diameter of the microlenses may be 20 to 100 mu m. Preferably 30 to 60 mu m. The light-converging function and the light-diffusing property of the microlens can be excellent while the appearance characteristic is good in the above-mentioned range, and the microlens can be actually manufactured easily. If the diameter of the microlens pattern is less than 20 mu m, there is a problem of low condensing efficiency with respect to the incident light incident at an angle that is not effective. If the diameter exceeds 100 mu m, the condensing efficiency with respect to the vertical light is reduced. May occur.

On the other hand, the microlens pattern layer may be formed as a pattern having the same height and diameter as shown in FIG. 10, or microlens patterns having different heights and diameters as shown in FIG. 11 may be mixed. It is ideal that the microlens pattern increases the density to a maximum and has a degree of impregnation of 1/2 because the optical characteristics vary greatly depending on the density and the aspect ratio of the lens.

In FIG. 12, a prism pattern layer 213 is formed on one surface of the reflective polarizer, and the height (a) of the prism may be 10 to 50 μm. If the height of the prism pattern is less than 10 mu m, the base film may be damaged by pressure when manufacturing the shape of the prism pattern portion. If the height exceeds 50 mu m, the light transmittance of the light incident on the light source may be reduced.

Also, the pitch b of the prism may be 20 to 100 mu m. If the pitch of the prism pattern is less than 20 탆, the embossing is difficult and the complication of the pattern layer implementation and manufacturing process may occur. If the pitch exceeds 100 탆, the moire phenomenon tends to occur, .

On the other hand, the prism shape may be formed in a pattern having the same height and pitch as shown in FIG. 12, or prism patterns having different heights and pitches as shown in FIG. 13 may be mixed. Such a prism pattern may be made of a material having a refractive index higher than that of the base film. If the refractive index of the base film is higher, a part of the light incident on the back surface of the base film may not be incident on the prism structure Because. Preferably, the prism shape is preferably a linear prism shape, the vertical section is triangular, and the triangle has an angle of 60 to 110 degrees with respect to a vertex opposed to the lower surface.

The material of the structured surface layer is preferably a polymer resin including a thermosetting or photocurable acrylic resin or the like. For example, the prism pattern can be an unsaturated fatty acid ester, an aromatic vinyl compound, an unsaturated fatty acid and a derivative thereof, or a vinyl cyanide compound such as methacryl nitrile. Specific examples thereof include uretanic acrylate, methacrylic acrylate Resin or the like can be used. The structured surface layer can also be made of a material having a higher refractive index than the reflective polarizer.

Next, a method for producing a reflective polarizer in which the dispersion of the present invention is dispersed will be described.

First, as step (1), the base component, the dispersion component, and the skin layer component are supplied to the extruder. The base component can be used without limitation as long as it is used in a reflective polarizer in which a conventional dispersion is dispersed. Preferably, the base component is polyethylene naphthalate (PEN), co-polyethylene naphthalate (co-PEN), polyethylene terephthalate (PET) (PS), polymethylmethacrylate (PMMA), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PS), polyethylene terephthalate (PC), polycarbonate (PE), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile blend (SAN), ethylene vinyl acetate (PA), polyacetal (POM), phenol, epoxy (EP), urea (UF), melanin (MF), unsaturated polyester (UP), silicone (SI) and cycloolefin polymers, May be a PEN.

The dispersion component can be used without limitation as long as it is usually used in a reflective polarizer in which a dispersion is dispersed. Preferably, the dispersion component is selected from the group consisting of polyethylene naphthalate (PEN), co-polyethylene naphthalate (co-PEN), polyethylene terephthalate (PET) (PS), polymethyl methacrylate (PMMA), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PS), polyethylene terephthalate (PE), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile blend (SAN), ethylene vinyl acetate (PA), polyacetal (POM), phenol, epoxy (EP), urea (UF), melamine (MF), unsaturated polyester (UP), silicone (SI) and cycloolefin polymers may be used alone or in combination And more preferably Dimethyl-2,6-naphthalene dicarboxylate, dimethyl terephthalate and ethylene glycol, hexanediol di Im croissant monomers such as methanol (CHDM) they can be suitably polymerized co-PEN.

The skin layer component may be a conventionally used component, but may be any of those used in reflective polarizers, preferably polyethylene naphthalate (PEN), copolyethylene naphthalate (co-PEN), polyethylene (PS), polymethylmethacrylate (PMMA), polybutylene terephthalate (PBT), poly (ethylene terephthalate), poly (ethylene terephthalate) Polypropylene (PP), polyethylene (PE), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile blend (EVA), polyamide (PA), polyacetal (POM), phenol, epoxy (EP), urea (UF), melanin (MF), unsaturated polyester (UP) Alone or in combination. Can and may be more preferably, dimethyl 2,6-naphthalenedicarboxylate, dimethyl terephthalate and ethylene glycol, Im chroman-hexane dimethanol (CHDM), such as the monomers are suitably polymerized co-PEN.

On the other hand, the base component and the dispersion component may be supplied separately to the extruders, and in this case, the extruder may be composed of two or more. It is also included in the present invention to feed one extruded portion including a separate supply path and a distribution port so that the polymers do not mix. The extruder may be an extruder, which may further include a heating means or the like to convert the supplied polymers in the solid phase into a liquid phase.

The viscosity of the base component is designed to be different from that of the dispersion component so that there is a difference in polymer flow so that the dispersion component can be arranged inside the base component. The following base component and the dispersion component pass through the mixing zone and the mesh filter zone, and the dispersion component is randomly arranged in the base material with a difference in viscosity.

Then, at least one surface of the core layer is joined with the skin layer component transferred from the extrusion portion. Preferably, the skin layer component may be laminated on both sides of the core layer. When the skin layers are laminated on both sides, the material and the thickness of the skin layer may be the same or different from each other.

Next, the dispersion control unit induces spreading in the flow control unit so that the dispersion component contained in the substrate can be randomly arranged. Specifically, Figure 14 is a cross-sectional view of a coat-hanger die, which is a type of preferred flow control that may be applied to the present invention, and Figure 15 is a side view. The size and arrangement of the cross-sectional areas of the dispersion components can be controlled at random by appropriately adjusting the extent of spreading of the substrate. In FIG. 14, since the substrate on which the skin layer transferred through the flow path is spread spreads widely from side to side in the coat-hanger die, the dispersion component contained therein also spreads to the left and right.

According to a preferred embodiment of the present invention, there is provided a method of manufacturing a liquid crystal display device, comprising: cooling and smoothing a spreader-derived polarizer transferred from a flow control unit; stretching the polarizer through the smoothing step; And a step of opening and fixing the stretched polarizer.

First, the step of cooling and smoothing the polarizer transferred from the flow control unit may be performed by cooling the same used in the production of a general reflective polarizer, solidifying it, and then performing a smoothing step through a casting roll process or the like.

Thereafter, a step of stretching the polarizer through the smoothing step is performed. The stretching can be performed through a conventional stretching process of a reflective polarizer, thereby causing a refractive index difference between a base component and a dispersing component to cause a light modulation phenomenon at the interface, and the spreading induced first component Body component) is further reduced in aspect ratio by stretching. For this purpose, the uniaxial stretching or biaxial stretching can be preferably performed in the stretching step, and more preferably uniaxial stretching can be performed. In the case of uniaxial stretching, stretching may be performed in the longitudinal direction of the first component. The stretching ratio may be 3 to 12 times. On the other hand, a method of changing an isotropic material to birefringent is commonly known. For example, in the case of stretching under an appropriate temperature condition, the dispersion molecules may be oriented so that the material becomes birefringent.

Next, the final reflective polarizer can be manufactured through the steps of opening and fixing the stretched polarizer. The thermal fixation may be heat-set through a conventional method, preferably at 180 to 200 ° C for 0.1 to 3 minutes through an IR heater.

Next, a structured surface layer is formed on at least one surface of the reflective polarizer (core layer) manufactured as the step (2). At this time, a primer layer may be further formed on at least one surface of the core layer to facilitate the formation of the structured surface layer. This makes it possible to improve the adhesion, appearance and electrophotographic characteristics of the structured surface layer. Examples of the material include, but are not limited to, acrylic, ester, and urethane. The primer layer can be formed thinner than the other layers, and the thickness of the primer layer can be adjusted to improve the light transmittance and reduce the reflectance.

The thickness of such a primer layer may be from 5 nm to 300 nm. If the thickness of the primer layer is less than 5 nm, the adhesion between the core layer and the structured surface layer may be insufficient. If the thickness of the primer layer exceeds 300 nm, unevenness or molecular aggregation may occur during primer treatment.

Meanwhile, the reflective polarizer of the present invention can form a structured surface layer on at least one surface to maximize the light collecting effect and prevent irregular reflection on the surface, thereby remarkably improving the brightness.

The structured surface layer that can be applied in the present invention is a structure capable of improving the light collecting effect, and may be a fine pattern layer. The fine patterns that can be applied in this case may be any one or more selected from the group consisting of prisms, lenticular, microlenses, triangular pyramid, and pyramid patterns, and each of them may be formed by forming a pattern alone or in combination. Also, even when a pattern is formed alone, the pattern may be constant, or the height, the pitch, and the like may be differently arranged.

The material of the structured surface layer is preferably a polymer resin including a thermosetting or photocurable acrylic resin or the like. For example, the prism pattern can be an unsaturated fatty acid ester, an aromatic vinyl compound, an unsaturated fatty acid and a derivative thereof, or a vinyl cyanide compound such as methacryl nitrile. Specific examples thereof include uretanic acrylate, methacrylic acryl Late resin and the like can be used. The structured surface layer can also be made of a material having a higher refractive index than the reflective polarizer.

On the other hand, the fine pattern layer can be produced through a mold film for pattern formation. As the material of the mold film for pattern formation, a film having transparency, flexibility, predetermined tensile strength and durability can be used, and it is preferable to use a PET film.

In this case, according to a preferred embodiment of the present invention, the step (2) comprises the steps of: i) transferring the reflective polarizer to the master roll formed on one surface of the patterned reverse phase of the structured surface layer, Or applying a molten polymer resin to the core layer surface; And ii) UV-curing the polymer resin by irradiating UV or heat while the polymer resin is press-formed on the pattern surface of the master roll, and separating the polymer resin.

According to another preferred embodiment of the present invention, the polymer resin may be secondarily cured by irradiating UV or heat again after the step ii).

16 is a schematic view showing a process of forming a fine pattern according to a preferred embodiment of the present invention, and FIG. 17 is a cross-sectional view showing the detailed structure of the forming unit of FIG. In FIG. 16, the reflective polarizer 770 is released from the star trolley 755 and passes through the guide roll 754 and the infrared lamp 751. In this process, the reflection type polarizer 770 is surface-modified by the infrared rays of the infrared lamp, and the adhesion with the pattern formation layer 771 is improved. The reflective polarizer 770 leaving the star trolley 755 enters the master roll 705 via the pattern guide roll 764 so that the patterned surface of the master roll 705 from the injection unit 742, (771) material, a pattern layer polymer is applied and merged with the base layer (770). In this process, the resin is a resin melted at room temperature and can be primary-cured due to the primary UV light emitted from the primary UV curing unit 752 provided under the master roll 705. In this case, the temperature around the curing unit 752 is 20 to 30 ° C, the temperature of the heat generated when the resin is cured is 40 to 80 ° C, and the glass transition temperature (Tg:

A temperature that indicates a change in properties such as soft rubber before undergoing a complete phase change from solid to liquid). In the glass transition state, the pattern forming layer 771, which completely copies the pattern shape of the master roll surface, passes through the pattern guide rolls 764 again, and a pattern in which the reflection type polarizing element 770 and the pattern forming layer 771 are combined is formed Shaped by the reflection type polarizer 772, passed through the guide roll 754, and wound on the finish roll 756.

As shown in FIG. 16, the cross section of the reflection type polarizer 772 having the turn formed by irradiating UV light twice is a surface contrary to the cross section of the master roll 705. For example, If it is an engraved surface, the reflective polarizer 772 with the turn formed becomes the embossed surface of the emboss.

In this case, according to a preferred embodiment of the present invention, the step (2) includes the steps of: a) transferring the reflective polarizer; b) transferring the mold film for pattern formation formed on one surface of the reversed phase pattern of the structured surface layer; c) bringing the one side of the reflective polarizer and the one side of the pattern-forming mold film into contact with each other; d) filling fluid between the patterns by injecting a fluid material into a region where the reflective polarizer and the mold film for pattern formation are in close contact with each other; e) applying the material to the reflective polarizer by curing the material filled between the patterns; And f) separating the mold film for pattern formation and the reflective polarizer coated with the material, wherein the steps a) and b) may be performed in any order.

Advantageously, a step of filling the material evenly between the patterns by applying pressure between the reflective polarizer and the mold film adhered between steps d) and e) may be further included.

Advantageously, the step e) may comprise irradiating the material filled between the patterns with heat or UV.

18 is a schematic view of a process of forming a fine pattern according to another preferred embodiment of the present invention. First, the reflective polarizer 810 wound on the first roll 820 is conveyed by guide rollers 830a through 830c. At this time, the shaping mold 842 of the pattern molding unit 840 is also conveyed / rotated while being wound around the master roll 844 and the pattern guide rolls 846a and 846b. At this time, since the master roll 844 is engaged with the guide rolls 830c and 830d, the reflective polarizer 810 is attracted to the guide roll 830c and engaged with the molding die 842. [ Here, the guide roll 830c performs a gap adjusting function to adjust the thickness of the pattern layer of the coating liquid applied to the reflective polarizer 810, that is, the angled reflective polarizer 812 in which the pattern layer is made of resin. More specifically, when the guide roll 830c is brought into close contact with the master roll 844, the pattern layer of the reflective polarizer can be made thinner. On the contrary, when the guide roll 830c is further separated from the master roll, The pattern layer can be formed thicker. The thickness of the reflective polarizer pattern layer can be controlled by the viscosity of the coating liquid, the patterning speed, and the tension of the reflective polarizer in addition to the interval between the guide roll 830c and the master roll 844.

The coating liquid is injected by the coating liquid injecting means 860 at the point where the guide roll 830c and the master roll 844 are engaged with each other by the reflective polarizer 810 and is pushed into the patterns of the molding die 842, Is uniformly distributed and pattern-formed by the pressure between the guide roll 830c and the master roll 844. [ The coating liquid distributed between the patterns is cured by heat or UV emitted from the curing means 870. The reflection type polarizing element having the patterned coating liquid cured and applied is separated from the molding die 842 while being guided by the guide roll 830d and the reflective polarizing element 812 having the pattern is conveyed by the guide roll 830e, 2 roll 850. As shown in Fig. Here, the guide roll 830d performs a peeling function for separating the reflective polarizer 812 having the coating liquid applied thereto, that is, the pattern layer formed thereon, from the molding die 842.

In the above description, the reflective polarizer 810 and the reflective polarizer 812 having the pattern layer are connected to each other and are classified for ease of explanation. That is, the reflective polarizer 810 refers to a state before the pattern is formed, and the reflective polarizer 812 having the pattern layer formed thereon is coated with the coating liquid, which is patterned while passing through the pattern molding portion 840, And the state is completed. 18 shows only a part of the pattern layer formed on the reflective polarizer 812 on which the pattern layer is formed. In reality, the reflective polarizer wound on the second roll 850 also has a pattern layer formed thereon.

19 is a schematic view of a process of forming a fine pattern according to another preferred embodiment of the present invention. Specifically, the forming mold 942 is formed into a roll type with a length corresponding to the length of the reflective polarizer 910, so that the reflective polarizer 912 on which the pattern layer is formed has no seams.

The second embodiment of the optical member manufacturing apparatus according to the present invention also includes a first roll 920 on which a reflective polarizer 910 is wound and a second roll 950 on which a reflective polarizer 912 with a pattern layer is wound Guide rolls 930a to 930f are provided between the first roll 920 and the second roll 950 for transferring the reflective polarizer having the reflective polarizer and the pattern layer formed on both sides thereof. Between the guide roll 930c and the guide roll 930d, a master roll 946 of the pattern molding portion 940 is closely attached to apply the coating liquid to the reflective polarizer 910. It goes without saying that the number and position of the guide rollers 930a to 930f may be changed according to the operation state. The pattern molding unit 940 includes a film forming mold 942 in which a pattern shape is implemented, a third roll 944 on which a forming mold is wound, a pressing roll 944 for pressing the coating liquid onto the forming mold, A master roll 946 for shaping and applying this to the reflection type polarizer 910, pattern guide rolls 947a to 947d for conveying the forming mold, and a fourth roll 948 for conveying the formed molding mold. It goes without saying that the number and position of the pattern guide rolls 947a to 947d can be changed according to the operation state.

Unlike the embodiment shown in Fig. 18, the above-described forming mold 942 is wound on the third roll 944 while being fed by the master roll 946 and guide rolls 947a to 947d to the reflection type polarizer 910 After the pattern of the coating liquid is formed, it is wound on the fourth roll 948. At this time, it is preferable that the forming mold 942 is formed to have the same length as that of the reflection type polarizer 910, and the reflection type polarizer 912 having the pattern layer formed thereon can be provided with the entire area So that the pattern is uniformly formed. Although only a part of the pattern embodied in the pattern layer of the forming mold is shown in Fig. 19, in actual practice, the pattern is implemented throughout the forming mold.

A coating liquid injecting unit 960 for injecting a coating liquid is provided at a point where the reflective polarizer 910 is drawn into the pattern molding unit 940, that is, at a point where the guide roll 930c and the master roll 946 are in close contact with each other A curing unit 970 for curing the coating liquid by irradiating heat or UV is provided at a point where the reflection type polarizer and the forming mold 942 are in close contact with each other.

Specifically, FIG. 20 shows an example of a liquid crystal display device employing the reflective polarizer of the present invention, in which a reflection plate 280 is inserted on a frame 270, a cold cathode fluorescent lamp 290 is mounted on the upper surface of the reflection plate 280, . An optical film 320 is disposed on the upper surface of the cold cathode fluorescent lamp 290. The optical film 320 includes a diffusion plate 321, a light diffusion film 322, a prism film 323, a reflection type polarizer 324 and the absorption polarizing film 325 are stacked in this order, but the order of lamination may be changed depending on the purpose, or a part of the constituent elements may be omitted or a plurality of them may be provided. For example, the diffusion plate 321, the light diffusion film 322, the prism film 323, and the like may be omitted from the overall configuration and may be changed in order or formed at different positions. Further, a phase difference film (not shown) or the like can also be inserted at an appropriate position in the liquid crystal display device. Meanwhile, the liquid crystal display panel 310 may be positioned on the upper surface of the optical film 320 by being inserted into the mold frame 300.

The light emitted from the cold cathode fluorescent lamp 290 reaches the diffuser plate 321 of the optical film 320. The light transmitted through the diffusion plate 321 passes through the light diffusion film 322 in order to advance the proceeding direction of the light perpendicularly to the optical film 320. The film having passed through the light diffusion film 322 reaches the reflection type polarizer 324 after passing through the prism film 323, thereby causing light modulation. Specifically, the P wave passes through the reflection type polarizer 324 without loss, but light modulation (reflection, scattering, refraction, etc.) occurs in the case of the S wave and is reflected again by the reflection plate 280, which is the back surface of the cold cathode fluorescent lamp 290 And the properties of the light are randomly changed into a P wave or an S wave, and then pass through the reflective polarizer 324 again. And then reaches the liquid crystal display panel 310 after passing through the absorption polarizing film 325. [ As a result, when the reflective polarizer of the present invention is inserted into a liquid crystal display device due to the above-described principle, remarkable improvement in luminance can be expected as compared with a general reflective polarizer. Meanwhile, the cold cathode fluorescent lamp 290 may be replaced with an LED.

In the present invention, the use of the reflective polarizer is described mainly with respect to the liquid crystal display, but the present invention is not limited thereto, and can be widely used in flat panel display technologies such as projection display, plasma display, field emission display and electroluminescence display.

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

≪ Example 1 >

(PEN) having a refractive index of 1.65 as a dispersion component, and polycyclohexylenediamine (PEN) having a polymerization activity of 1: 2 by mole ratio of terephthalate, ethyl glycol and cyclohexane dimethanol to 60% by weight of polycarbonate as a base component 38% by weight of methyl cyclohexylene dimethylene terephthalate (PCTG) and 2% by weight of a heat stabilizer containing phosphate The raw materials were respectively fed into the first extruder and the second extruder. 38% by weight of polycyclohexylene dimethylene terephthalate (PCTG) polymerized with 60% by weight of polycarbonate as a skin layer component and terephthalate, polymerization reaction of ethyl glycol and cyclohexane dimethanol at a molar ratio of 1: 2, 2 wt% of a phosphate stabilizer was added to the third extruder.

The extrusion temperature of the base component and the dispersion component was adjusted to 245 占 폚, and Cap. The polymer flow was adjusted through adjustment, and the dispersion fluid was randomly dispersed in the substrate through the passage through which the filteration mixer was applied. Then, the skin layer components were laminated on both sides of the substrate layer component. The spread of the polymer was induced in the coat hanger die of Figs. 14 and 15, which corrected the flow rate and pressure gradient. Specifically, the width of the die inlet is 200 mm, the thickness is 10 mm, the width of the die outlet is 1,260 mm, the thickness is 2.5 mm, and the flow rate is 1.0 m / min. Then, a smoothing process was performed on the cooling and casting rolls and stretched 6 times in the MD direction. Then, heat setting was performed through a heater chamber at 180 캜 for 2 minutes to produce a randomly dispersed polarizer having a thickness of 120 탆 (thickness including a skin layer: 300 탆) as shown in Table 1. (Nx: 1.88, ny: 1.58, nz: 1.58) of the poly (ethylene terephthalate) (PEN) component of the prepared reflection type polarizer and 60% by weight of polycarbonate was mixed with terephthalate, ethyl glycol and cyclohexane dimethanol 1: 38 wt.% Of polycyclohexylene dimethylene terephthalate (PCTG) polymerized in a molar ratio of 2: 1 and a refractive index of 2 wt.% Of a phosphate-containing heat stabilizer was 1.58. The core layer thickness is 120 占 퐉, and the skin layer thickness is 90 占 퐉 at the top and bottom.

Thereafter, the produced reflective polarizer was subjected to the same process as shown in FIG. 19 to prepare a reflective polarizer having a urethane acrylic prism pattern layer having a refractive index of 1.59. The height in the prism pattern was 20 mu m and the pitch was 40 mu m.

≪ Examples 2 to 5 and Comparative Examples 1 and 2 >

A randomly dispersed reflective polarizer was produced in the same manner as in Example 1 except for the conditions shown in Table 1 below.

<Experimental Example>

The following properties of the reflective polarizer prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were evaluated, and the results are shown in Table 1.

1. Relative luminance

In order to measure the brightness of the produced reflective polarizer, the following procedure was performed. The panel was assembled on a 32 "direct-type backlight unit equipped with a diffuser plate and a reflective polarizer, and the brightness was measured at nine points using a BM-7 meter of Topcon Co. The average value was shown.

Relative luminance is a relative value of the luminance of the other embodiments and the comparative example when the luminance of the reflective polarizer of Example 1 is taken as 100 (standard).

2. Visible lines

A reflective polarizer, a diffusion plate, a diffusion sheet, a prism sheet, and a brightness enhancement film

The panel was assembled on a 32 "direct-type backlight unit, and then the bright line appearance was evaluated. Specifically, the bright line visibility was evaluated by visually observing a bright line, and the number of bright lines was evaluated as 0 excellent, 1 good, 2 to 3 normal, and 4 to 5 or more poor.

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Aspect ratio 95 95 95 90 82 73 93 1 group 49 46 37 40 62 45 72 2 groups 39 48 30 43 23 44 28 3 groups 12 6 33 17 15 11 0 1/3 group 4.1 7.7 1.2 2.4 4.1 4.5 - Relative luminance  100 94 95 98 97 91 90 Polarization degree  81 78 78 80 79 78.5 73 Bright line appearance Very good Good Good usually usually Bad Bad

Aspect ratio: The number of dispersions in which the aspect ratio is 1/2 or less out of the total number of dispersants is expressed as%.

1 group, 2 groups and 3 groups: The number of dispersions in the cross-sectional area ranges of 1 group, 2 groups and 3 groups of the present invention among the dispersions whose aspect ratio is 1/2 or less is expressed as%.

1/3 group: 1 group number / 3 group number in%

As can be seen from the above Table 1, Examples 1 to 5 satisfying the range of the present invention are superior to Comparative Examples 1 and 2 in which the luminance, the polarization degree and the bright line appearance are all satisfactory. On the other hand, Example 1 belonging to the 1/3 group of the present invention exhibited excellent optical properties as compared with Examples 2 to 4 which do not satisfy this requirement. Furthermore, the optical properties of Example 1 were superior to those of Example 5 in which the content of one group was out of the range.

Since the reflective polarizer of the present invention has excellent light modulation performance, it can be widely used in fields where optical modulation is required. Specifically, it can be widely used in flat panel display technologies such as a liquid crystal display device, a projection display, a plasma display, a field emission display, and an electroluminescence display which require high brightness such as a mobile display, an LCD and an LED.

Claims (20)

A plurality of dispersing bodies disposed in the substrate so as to transmit the first polarized light to be externally irradiated and to reflect the second polarized light, wherein the plurality of dispersing bodies have refractive indexes different from each other in the at least one axial direction, Wherein at least 80% of the plurality of dispersions contained in the substrate have an aspect ratio of a minor axis length to a major axis length of 1/2 or less based on a vertical cross section in the longitudinal direction, and the cross- comprising at least three groups, the cross-sectional area of the first group is 0.2 ~ 2.0㎛ ^2, and the cross-sectional area of the second group is ² or less from 5.0㎛ 2.0㎛ ^2, greater than the cross-sectional area of the third group is from more than 5.0 10.0㎛ ² , The first group of dispersions, the second group of dispersions and the third group of dispersions are randomly arranged core layers;
And an integrated skin layer formed on at least one surface of the core layer. The method according to claim 1,
Wherein the number of dispersions of the third group among the dispersions having the aspect ratio of 1/2 or less is 10% or more. The method according to claim 1,
Wherein the number of the first groups of the dispersions having the aspect ratio of 1/2 or less is 30 to 50% and the number of the third groups is 10 to 30%. The method according to claim 1,
Wherein the number of dispersions of the first group / the number of dispersions of the third group is 3 to 5 among the dispersions having the aspect ratio of 1/2 or less. The method according to claim 1,
Wherein the refractive index of the base material and the dispersion body is 0.05 or less in refractive index with respect to two axial directions and the difference in refractive index with respect to the remaining one axial direction is 0.1 or more. The method according to claim 1,
Characterized in that the reflective polarizer is stretched in at least one axial direction, The method according to claim 1,
And a structured surface layer formed on at least one surface of the skin layer. 8. The method of claim 7,
And a primer layer for enhancing adhesion between the skin layer and the structured surface layer. 9. The method according to claim 7 or 8,
Wherein the structured surface layer is a fine patterned layer. 10. The method of claim 9,
Wherein the fine pattern is at least one selected from the group consisting of a prism, a lenticular, a micro lens, a triangular pyramid, and a pyramid pattern. (1) comprises a plurality of dispersing bodies inside a substrate for transmitting a first polarized light irradiated from the outside and reflecting the second polarized light, wherein the plurality of dispersing bodies have different refractive indexes in at least one axial direction Wherein at least 80% of the plurality of dispersions contained in the substrate have an aspect ratio of a minor axis length to a major axis length of 1/2 or less based on a vertical cross section in the longitudinal direction, includes groups of 3 or more the cross-sectional area different from the cross-sectional area of the first group is 0.2 ~ 2.0㎛ ^2, and the cross-sectional area of the second group is greater than ² 2.0㎛ 5.0㎛ ² or less, the cross-sectional area of the third group is greater than ² 5.0㎛ 10.0㎛ ² or less, dispersion of the first group, second group and third group of dispersion dispersed randomly arranged in the core layer of the body; And an integrated skin layer formed on at least one side of the core layer, the randomly distributed reflective polarizer comprising:
(2) A step of forming a structured surface layer on at least one side of the substrate. 12. The method of claim 11,
And a primer layer for enhancing adhesion between the skin layer and the structured surface layer. &Lt; RTI ID = 0.0 &gt; 8. &lt; / RTI &gt; 12. The method of claim 11,
Wherein the structured surface layer is a fine patterned layer. 14. The method of claim 13,
Wherein the fine pattern is at least one selected from the group consisting of a prism, a lenticular, a micro lens, a triangular pyramid, and a pyramid pattern. 13. The method according to claim 11 or 12,
Wherein the step (2) is performed through a pattern-forming mold film. 16. The method of claim 15, wherein step (2)
a) transferring the reflective polarizer;
b) transferring the mold film for pattern formation formed on one surface of the reversed phase pattern of the structured surface layer;
c) bringing the one side of the reflective polarizer and the one side of the pattern-forming mold film into contact with each other;
d) filling fluid between the patterns by injecting a fluid material into a region where the reflective polarizer and the mold film for pattern formation are in close contact with each other;
e) applying the material to the reflective polarizer by curing the material filled between the patterns; And
f) separating the mold film for pattern formation and the reflective polarizer coated with the material,
Wherein the steps a) and b) are performed independently of the order. 17. The method of claim 16,
Between step d) and step e)
Further comprising the step of filling the material between the second pattern and the second pattern by applying pressure to the substrate and the mold film in close contact with each other. 17. The method of claim 16,
Wherein the step (e) comprises the step of irradiating heat or UV to the material filled between the patterns. 16. The method of claim 15, wherein step (2)
I) contacting and transferring a base material to a master roll formed on one side of a pattern that is a reverse phase of the structured surface layer, and applying molten polymer resin to the pattern side of the master roll or the reflection type polarizer; And
Ii) UV-curing the polymer resin by irradiating UV or heat while the polymer resin is press-formed on the pattern surface of the master roll, and separating the polymer resin. 20. The method of claim 19,
Curing the polymer resin by irradiating UV or heat again after the step ii); Wherein the polarizer is a polarizer.

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