KR20140021279A - Integrated optical film - Google Patents

Abstract

An integral type optical film of the present invention can not only can prevent the separation because a reflective polarizing film and a light control film are integrally formed, the integral type optical film can also significantly improve handling property and assembly efficiency and also luminance. The reflective polarizing film of the present invention does not contain an extra adhesive layer and / or a protective layer (PBL) in an internal core and between the core layer and a skin layer because multiple groups with different average optical thicknesses are integrally formed. Additionally, the integrated optical film can reflect all of the S wave in the visible ray wavelength region because of the groups therewith. Therefore, the present invention has an advantage reducing manufacturing costs remarkably as well as maximizing optical properties in the limited thickness.

Description

[0001] INTEGRATED OPTICAL FILM [0002]

TECHNICAL FIELD [0001] The present invention relates to an integral optical film, and more particularly, to an integral optical film which is extremely advantageous in maximizing optical properties at a limited thickness.

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 polarizing film is provided between the optical cavity and the liquid crystal assembly.

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

The selective reflection of the S polarized light and the transmission of the P polarized light to the incident light of the reflection type polarizing film are performed in such a manner that a flat optical layer having anisotropic refractive index and a flat optical layer having an isotropic refractive index are alternately laminated, The refractive index difference, the optical thickness setting of each optical layer according to the stretching process of the laminated optical layer, and the refractive index change of the optical layer.

  That is, the light incident on the reflection type polarizing film repeats reflection of S polarized light and transmission of P polarized light while passing through each optical layer, and finally, only P polarized light of incident polarized light is transmitted to the liquid crystal assembly. On the other hand, as described above, the reflected S polarized light is reflected from the diffusive reflection surface of the optical cavity in a state where the polarization state is randomized and then transmitted to the reflective polarizing film. 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 polarizing film has a structure in which an isotropic optical layer and an anisotropic optical layer having different refractive indices are alternately laminated 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 There is a problem that the manufacturing process of the reflection type polarizing film is complicated. In particular, since each optical layer of the reflection type polarizing film has a flat plate structure, it is necessary to separate the P-polarized light and the S-polarized light corresponding to a wide incident angle range of the incident polarized light, so that the number of layers of the optical layer is excessively increased, As shown in FIG. 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 polarizing film (DBEF). Specifically, in the multilayer reflective polarizing film, the skin layers 9 and 10 are formed on both surfaces of the core layer 8. The core layer 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 approximately 200 layers. Separate adhesive layers 5, 6, and 7 are formed between the four groups 1, 2, 3, and 4 forming the core layer 8. 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 core layer becomes thick and the manufacturing cost rises. In addition, since the reflective polarizing film included in the display panel is limited in the thickness of the core layer for slimming, if the adhesive layer is formed on the core layer and / or the skin layer, the core layer is reduced by the thickness thereof. There was a bad problem. Further, since the inside of the core layer and the core layer and the skin layer are bonded by the adhesive layer, there is a problem that when the external force is applied, the elapse of 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 core layer 8 and separate adhesive layers 11 and 12 are formed between the core layer 8 and the skin layers 9 and 10 for bonding them. do. When the conventional skin layer of polycarbonate and PEN-coPEN are integrated with the alternately laminated core layer by co-extrusion, peeling may occur due to the compatibility member and the crystallization degree is about 15% There is a high risk of occurrence of birefringence. 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 for producing the conventional multilayer reflective polarizing film will be briefly described. After four co-extruded groups having different average optical thicknesses for forming the core layer are separately co-extruded, the four co-extruded four groups are stretched, The drawn four groups are bonded together with an adhesive to prepare a core layer. This is because the peeling phenomenon occurs when the core layer is stretched after bonding the adhesive. Thereafter, the skin layers are bonded to both sides of the core layer. 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 reflection type polarizing film are frequently released even when the decrease in luminance is reduced in terms of cost reduction.

Thus, a reflective polarizer is proposed in which a birefringent polymer stretched in the longitudinal direction is arranged in a substrate, not a multilayer reflective polarizing film, and a polymer capable of achieving the function of the reflective polarizing film is dispersed. 3 is a perspective view of a reflection type polarizing film 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 polarizing film. However, as compared with the above-mentioned alternately laminated reflection type polarizing film, 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 laminated reflective polarizer in the base material 21 having a width of 1580 mm and a height (thickness) of 400 m or less when a horizontal 32-inch display panel is manufactured on the basis of the vertical cross section of the reflective polarizing film At least 100% or more of the circular or elliptic birefringent polymer 22 having a cross-sectional diameter in the longitudinal direction of 0.1 to 0.3 탆 should be included. In this case, not only the production cost is excessively increased but also the equipment becomes excessively complicated, It is hardly possible to produce a facility for commercialization. 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. The birefringent chart can cause a light modulation effect at the light modulation interface of the internal part and the dissolution part, so that the optical properties can be achieved without arranging a very large number of chart marks like the above-mentioned birefringent polymer. 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.

However, when a reflection type polarizing film is inserted into an upper portion of the optical film, a gap is generated between the optical film and the reflection type polarizing film, so that natural light or a recycled P wave transmitted from the optical film does not reach the reflection type polarizing film, There has been a problem in that the temperature is lowered. In addition, since the reflective polarizing film and the diffusing film must be separately provided, a problem of remarkable increase in cost has arisen.

SUMMARY OF THE INVENTION It is a first object of the present invention to provide a monolithic optical film capable of improving luminance by preventing separation between an optical film and a reflective polarizing film.

A second object of the present invention is to provide a monolithic optical film employing a multilayer reflective polarizer with remarkably improved optical properties compared to a conventional multilayer reflective polarizer.

In order to solve the above-mentioned problems, the present invention relates to a light control film, a first layer integrally bonded to the light control film and having an in-plane birefringence for transmitting a first polarized light radiated from the outside and reflecting the second polarized light, Layer reflection polarizing film comprising a first layer and an alternately stacked second layer, wherein the first layer and the second layer have different refractive indices in at least one axial direction, and the first layer And the second layer are elongated in at least one axial direction, the first and second layers forming one repeating unit, the repeating units forming a group to reflect the transverse waves of the desired wavelength (S waves) , The groups are two or more, the groups are formed integrally, and the average optical thickness of the inter-group repeating units is different.

According to a preferred embodiment of the present invention, the core layer may include a skin layer integrally formed on at least one surface thereof.

According to a preferred embodiment of the present invention, the light control film may be a light diffusion film or a prism film.

According to a preferred embodiment of the present invention, an adhesive layer may be included between the reflective polarizing film and the light control film.

According to a preferred embodiment of the present invention, the absorption type polarizing film may be an iodine type or a dye type absorption type polarizing film.

According to a preferred embodiment of the present invention, the absorption type polarizing film may further include a protective film on at least one side thereof.

According to a preferred embodiment of the present invention, the first polarized light may be a longitudinal wave and the second polarized light may be a transverse wave.

According to another preferred embodiment of the present invention, the first layer is made of polyethylene naphthalate (PEN), copolyethylene naphthalate (co-PEN), polyethylene terephthalate (PET), polycarbonate (PC), polycarbonate (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 second layer is made of polyethylene naphthalate (PEN), copolyethylene naphthalate (co-PEN), polyethylene terephthalate (PET), polycarbonate (PC), polycarbonate (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 blend (SAN), ethylene vinyl acetate (EVA), polyamide (PA) ), Phenol, epoxy (EP), urea (UF), melamine (MF), unsaturated polyester (UP), silicone (SI), elastomer and cycloolefin polymer.

According to another preferred embodiment of the present invention, the repeating units may form three groups in order to reflect light of three wavelength bands.

According to another preferred embodiment of the present invention, the repeating units may form three groups to reflect light of four wavelength bands.

According to another preferred embodiment of the present invention, the desired wavelength may include a visible light band.

According to another preferred embodiment of the present invention, the optical thicknesses of the repeating units included in the same group may be within 30%, preferably within 20%, and more preferably within 15% of the average optical thickness.

According to another preferred embodiment of the present invention, the three reflection bands may include wavelength bands of 450 nm, 550 nm and 650 nm.

According to another preferred embodiment of the present invention, the four reflection bands may include wavelength bands of 350 nm, 450 nm, 550 nm and 650 nm.

According to another preferred embodiment of the present invention, the plurality of groups may have an average optical thickness of the repeating units of 5% or more, preferably 10% or more.

According to another preferred embodiment of the present invention, the repeating units included in one group may be at least 25, preferably at least 50, more preferably at least 100, and most preferably at least 150 repeating units.

According to another preferred embodiment of the present invention, the refractive index difference between the first layer and the second layer may be greater than the difference between the refractive indexes in the elongated axial direction and the refractive indices in the other axial directions.

According to another preferred embodiment of the present invention, the refractive indexes of the first layer and the second layer are such that the difference in refractive index between the two axial directions is 0.05 or less and the difference between the refractive indices in the other axial direction is 0.1 or more .

According to another preferred embodiment of the present invention, a birefringent interface may be formed between the first layer and the second layer.

According to another preferred embodiment of the present invention, the first layer has optical birefringence, and the second layer has optical isotropy.

According to another preferred embodiment of the present invention, an adhesive layer may not be formed between the group and the group.

According to another preferred embodiment of the present invention, an adhesive layer may not be formed between the core layer and the skin layer.

According to another preferred embodiment of the present invention, the skin layer may be stretched.

According to another preferred embodiment of the present invention, a backlight unit including the reflective polarizing film of the present invention is included.

According to another preferred embodiment of the present invention, the backlight unit may further include a reflection unit that reflects the modulated light from the reflection type polarizing film back to the reflection type polarizing film.

According to another preferred embodiment of the present invention, there is provided a liquid crystal display device including the backlight unit.

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

'Polymer has birefringence' means that when light is irradiated to fibers of different refractive index along the direction, the light incident on the polymer is refracted into two light beams with 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.

The 'aspect ratio' means the ratio of the shortening length to the longest length based on the vertical section in the longitudinal direction of the elongated body.

In the integrated optical film of the present invention, since the reflection type polarizing film and the light control film are integrally formed, not only can the separation be prevented, but also handling and assemblability are remarkably improved and brightness can be improved.

The reflective polarizing film of the present invention does not include a separate adhesive layer and / or a protective layer (PBL) in the core layer and between the core layer and the skin layer since a plurality of groups having different average optical thicknesses are integrally formed. This makes it possible to remarkably reduce the manufacturing cost and to maximize optical properties at a limited thickness. Also, since a plurality of groups having different average optical thicknesses are formed, all the S waves in the visible light wavelength range can be reflected. This makes it possible to remarkably reduce the manufacturing cost and to maximize optical properties at a limited thickness.

1 is a schematic view for explaining the principle of a conventional reflective polarizing film.
2 is a cross-sectional view of a currently used multilayer reflective polarizing film (DBEF).
3 is a perspective view of a reflection type polarizing film including a bar-shaped polymer.
4 is a cross-sectional view of an integral optical film according to a preferred embodiment of the present invention.
5 is a cross-sectional view of a multilayer reflective polarizing film according to a preferred embodiment of the present invention.
6 is a cross-sectional view of a multilayer reflective polarizing film according to another preferred embodiment of the present invention.
7 is a cross-sectional view of a multilayer reflective polarizing film according to another preferred embodiment of the present invention.
Fig. 8 is a perspective view of the claw distribution plates of the slit-type extrusion head which can be used in the present invention, Fig. 9 is a bottom view thereof, and Fig. 10 is a coupling diagram.
11 is a cross-sectional view of a multi-layer composite flow according to a preferred embodiment of the present invention.
12 is a schematic view including two first pressing means for forming two multi-layer composite streams according to a preferred embodiment of the present invention.
13 is a schematic view including two second pressurizing means for forming two multi-layer composite streams according to a preferred embodiment of the present invention.
FIG. 14 is a schematic view showing a laminated portion of a multilayer composite flow sheet and a skin layer according to a preferred embodiment of the present invention. FIG.
Figure 15 is a cross-sectional view of a coat-hanger die in accordance with a preferred embodiment of the present invention, and Figure 16 is a side view.
17 is a schematic view of an apparatus for manufacturing a multilayer reflective polarizer according to a preferred embodiment of the present invention.
18 is a schematic view of an apparatus for manufacturing a multilayer reflective polarizer according to another preferred embodiment of the present invention.
19 is a schematic diagram of an apparatus for manufacturing a multilayer reflective polarizer 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 present invention provides an integral optical film formed on the light control film and integrating the multilayer reflective polarizing film of the present invention.

The integration in the optical film of the present invention means that the light control film and the reflection type polarizing film are integrated by the interlayer bonding means and the bonding means is directly applied between the light control film and the reflection type polarizing film, When a protective film or a release film or the like is laminated on the substrate, it can be applied for multi-layer bonding purposes.

4 is a schematic view of an integrated optical film 30 which is a preferred embodiment of the present invention. An adhesive layer or an adhesive layer 32 and a multilayer reflective polarizing film 33 are sequentially laminated on a light control film 31, Respectively.

As shown in FIG. 4, the light emitted from the light source (not shown) reaches the light control film 31 and diffuses to the planar light source and / or is condensed. The light thus adjusted passes through the reflective polarizing film 33 (P polarized light) perpendicular to the stretching direction while passing therethrough, and polarized light (S polarized light) in the remaining stretching direction is reflected downward. In this process, the S polarized light is reflected again at the bottom, and the polarized light is changed and then comes up. The P polarized light passes through the changed polarized light, and the remaining S polarized light recycles and the brightness rises.

Therefore, by integrating the light control film 31 and the multilayer reflection type polarizing film 33, the integrated optical film 30 of the present invention can prevent the separation between the absorption type polarizing film and the reflection type polarizing film, .

First, the light control film of the present invention will be described. The light control film of the present invention may be a light diffusion film for diffusing the light emitted from the light source into a planar light source. The light control film may also be a combination of various optical films used in a liquid crystal display to control light. Preferably, the light-diffusing film and the reflective polarizing film may be integrated or integrated between the light-diffusing film and the reflective polarizing film and the condensing film (for example, a prism film). In this case, the light-condensing film may be located between the light-diffusing film and the reflective polarizing film or may be located above the reflective polarizing film.

The thickness of the pressure-sensitive adhesive layer or the adhesive layer is not particularly limited. However, the thickness of the pressure-sensitive adhesive layer or the adhesive layer is preferably 0.1 To 10 mu m.

Next, the multilayer reflective polarizing film used in the present invention will be described.

According to one preferred embodiment of the present invention, the multilayer reflective polarizing film of the present invention is a multilayer reflective polarizing film comprising a first layer having in-plane birefringence and a first layer having an in-plane birefringence in order to transmit the first polarized light irradiated from the outside and to reflect the second polarized light. Wherein the first layer and the second layer are different in refractive index in at least one axial direction and the first layer and the second layer are elongated in at least one axial direction, Layer and the second layer form one repeating unit, and the repeating units form a group for reflecting a transverse wave of a desired wavelength (S wave), wherein the groups are two or more, the groups are integrally formed, And the average optical thickness of the inter-group repeating units is different.

Preferably, a skin layer integrally formed on at least one side of the core layer may be optionally included.

5 is a cross-sectional view of a multilayer reflective polarizing film according to a preferred embodiment of the present invention. Specifically, skin layers 189 and 190 are integrally formed on both sides of the core layer 180, and the core layer 180 is divided into two groups A and B. In the drawing, a dotted line dividing groups A and B means a virtual line. In the group A, the first layers 181 and 183 corresponding to the first component and the second layers 182 and 184 corresponding to the second component are alternately stacked. Herein, the first layer 181 and the second layer 182 are defined as one repeating unit (R1), and the group A may include at least 25 repeating units. Group B also alternately stacks the first layer (185, 187) and the second layer (182, 184) corresponding to the second component. Herein, the first layer 185 and the second layer 186 are defined as one repeating unit (R2), and the group A may include at least 25 repeating units, preferably 50 or more, more preferably 50 or more, May be 100 or more, and most preferably 150 or more. The thicknesses of the first layer and the second layer may be the same.

Also preferably, the core layer may include a skin layer integrally formed on at least one side thereof, which may be selectively applied.

On the other hand, the average optical thicknesses of the repeating units (R1) included in the group A and the average optical thicknesses of the repeating units (R2) included in the group B are different. This makes it possible to reflect different wavelengths of S waves. In addition, the optical thickness of the repeating units contained in group A may have an optical thickness variation within 30%, preferably within 20%, more preferably within 15%, based on the average optical thickness of group A. Here, the optical thickness means n (refractive index) x d (physical thickness). On the other hand, the wavelength of light and the optical thickness are defined by the following relational expression (1).

[Relation 2]

? = 2 (n ₁ d ₁ + n ₂ d ₂ )

(Nm), n ₁ is refractive index of one layer, n ₂ is refractive index of two layers, d ₁ is physical thickness of one layer (nm), and d ₂ is physical thickness of two layers (nm).

Therefore, when the average optical thickness of the group A is 200 nm, it is possible to reflect a transverse wave (S wave) of a wavelength of 400 nm by the above-mentioned relational expression 2. [ In this case, if the thickness deviation is 20%, the wavelength band of about 320 to 480 nm can be covered. If the average optical thickness of the repeating units (R2) in the group B is 130 nm, the transverse wave (S wave) of 520 nm wavelength can be reflected by the relational expression 1. If the thickness deviation is 20%, the wavelength band of about 420 to 620 nm And in this case can be partially overlapped with the wavelength band of the group A, thereby maximizing the light modulation effect. In addition, since the first layer having the in-plane birefringence must transmit the P wave and reflect the S wave, the refractive index (n) can be set based on the thickness direction (refractive index of the z axis) through which the light passes and the average optical thickness can be calculated.

On the other hand, they are integrally formed without an adhesive layer between the group and the group. And is also integrally formed between the core layer and the skin layer. As a result, it is possible not only to prevent deterioration of optical properties due to the adhesive layer but also to add more layers to a limited thickness, thereby remarkably improving the optical properties and significantly reducing the manufacturing cost. 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.

The skin layer may be selectively formed.

6 is a cross-sectional view of a multilayer reflective polarizing film according to another preferred embodiment of the present invention. 5, three groups (A, B, and C) having different average optical thicknesses are formed in the core layer, and the average optical thicknesses of the inter-group repeating units are different from each other.

7 is a cross-sectional view of a multilayer reflective polarizing film according to another preferred embodiment of the present invention. Specifically, the core layer is formed of four groups, and each of the groups can be adjusted in the average optical thickness to cover the light wavelength band of 350 nm, 450 nm, 550 nm and 650 nm, respectively. In this case, the outer layer of the core layer is formed with groups having a large average optical thickness, and groups having a small average optical thickness in the inner layer can be formed. On the other hand, in order to cover the entire visible light region, the average optical thickness of the repeating units should be determined so as to correspond to various light wavelengths. To set the average optical thickness of the repeat units per group within the core layer to correspond to the optical wavelength band of 350 nm, 450 nm, 550 nm and 650 nm, the average optical thickness of the first component between the groups may be different by at least 5% , And more preferably 10% or more. This allows reflection of the S wave in the entire visible region.

According to a preferred embodiment of the present invention, a birefringence interface may be formed between the first layer and the second layer forming the core layer. Specifically, in the multilayer reflective polarizing film in which the first layer and the second layer are alternately laminated, the substantial coincidence or incoincidence of the refractive index along the X, Y and Z axes in the space between the first and second layers is It affects the degree of scattering of the polarized beam along the 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. If the refractive index of the second layer substantially coincides with the refractive index of the first layer along an axis, incident light polarized with an electric field parallel to this axis is not scattered regardless of the size, shape and density of the portion of the first layer Will pass through the first layer. 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 boundary between the second layer and the first layer, while the second polarized light (S wave) The light is affected by the birefringent interface formed at the boundary. 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, the first layer and the second layer may form a birefringence interface at the interface thereof to cause a light modulation effect, so that when the second layer is optically isotropic, the first layer may have birefringence. Specifically, when the refractive index in the x-axis direction 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 indexes of the second layer are nX2, nY2 and nZ2, Plane birefringence may occur. More preferably, the first layer and the second layer may differ in at least one of X, Y, and Z-axis refractive indexes, and more preferably, when the extension axis is the X-axis, Is 0.05 or less, and the difference in refractive index with respect to the X-axis can 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.

Meanwhile, according to a preferred embodiment of the present invention, the total number of layers of the multilayer reflective polarizing film may be 100 to 2000. The thickness range of the repeating unit can be appropriately designed according to the wavelength range of the desired light and the refractive index, and may preferably be 65 to 300 nm. The thicknesses of the first layer and the second layer forming the repeating unit may be substantially the same or different. In the present invention, the core layer may have a thickness of 10 to 300 占 퐉 and the skin layer may have a thickness of 50 to 190 占 퐉, but the present invention is not limited thereto.

Next, a method of producing a multilayer reflective polarizing film integrally formed without including the adhesive layer of the present invention will be described.

First, in step (1), the first component, the second component, and the skin layer component are supplied to the extruding portions, respectively. At this time, the skin layer component can be selectively added depending on the presence or absence of the skin layer. The first component is a polymer dispersed in the second component forming the base material, and may be used without limitation as long as it is used in a reflective polarizer in which a conventional polymer is dispersed. Preferably, the first component is polyethylene naphthalate (PEN), copolyethylene Polymers such as phthalates (co-PEN), polyethylene terephthalate (PET), polycarbonate (PC), polycarbonate (PC) alloys, polystyrene (PS), heat resistant polystyrene (PS), polymethylmethacrylate (PB), polypropylene (PP), polyethylene (PE), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyimide (PI), polyvinyl chloride (SAN), ethylene vinyl acetate (EVA), polyamide (PA), polyacetal (POM), phenol, epoxy (EP), urea (UF), melanin (MF), unsaturated polyesters (SI) and cycloolefin polymers Number and may be more preferably PEN.

The second component forms a substrate and can be used without limitation as long as it is used as a material of a substrate in a reflective polarizer in which a polymer is dispersed. Preferably, the second component is selected from the group consisting of polyethylene naphthalate (PEN), co-polyethylene naphthalate ), Polyethylene terephthalate (PET), polycarbonate (PC), polycarbonate (PC) alloy, polystyrene (PS), heat resistant polystyrene (PS), polymethylmethacrylate (PMMA), polybutylene terephthalate ), Polypropylene (PP), polyethylene (PE), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile (EVA), polyamide (PA), polyacetal (POM), phenol, epoxy (EP), urea (UF), melanin (MF), unsaturated polyester (UP) The olefin polymer may be used singly or in combination Can be used 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.

The skin layer component can be used without limitation as long as it is usually used in a reflective polarizer in which a polymer is dispersed. Preferably, the skin layer component may be a polyethylene terephthalate (PET), a polycarbonate (PC), a polycarbonate (PC) ), Heat resistant polystyrene (PS), polymethyl methacrylate (PMMA), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PE), acrylonitrile butadiene styrene (ABS), polyurethane ), Polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile blend (SAN), ethylene vinyl acetate (EVA), polyamide (PA), polyacetal (POM) (UF), melamine (MF), unsaturated polyesters (UP), silicon (SI) and cycloolefin polymers. The polycarbonate alloy is preferably made of a polycarbonate and a modified glycol polycyclohexylene dimethylene terephthalate (PCTG), more preferably a polycarbonate and a modified glycol polycyclohexane (PCTG) may be a polycarbonate alloy having a weight ratio of 5:95 to 95: 5. In the meantime, the skin layer of the present invention is preferably made of a material having a small change in refractive index in the spreading and stretching process, more preferably polycarbonate or polycarbonate glass.

Meanwhile, the first component, the second component, and the skin layer component may be separately supplied to the independent extrusion units. In this case, the extrusion unit may be composed of three 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.

On the other hand, the skin layer component can be selectively contained depending on the presence or absence of the skin layer.

Next, as step (2), two or more multi-layer composite streams in which the repeating units of the first component and the second component are alternately stacked are formed, and each of the multi-layer composite streams is formed so as to reflect a transverse wave , And the first component and the second component transferred from the extrusion unit are put into a plurality of compound extrusion compartments to form two or more multilayer composite streams having different average optical thicknesses of the repeating units.

8 to 10 are a perspective view, a bottom view, and a coupling view of the separating plates of the slit-type extrusion head which can be used in the present invention. FIG. 6 is a perspective view showing the coupling structure of the detent plates of the slit-type extrusion apparatus. FIG. The first receiving distribution plate S1 located at the upper end of the slit-shaped extrusion opening may be constituted by the first component supply path 50 and the second component supply path 51 in the interior thereof. So that the first component transferred through the extrusion portion can be supplied to the first component supply path 50 and the second component can be supplied to the second supply path 51. A plurality of such supply paths may be formed as the case may be. Polymers that have passed through the first receiving distribution plate S1 are transported to the second receiving distribution plate S2 located below. The first component injected through the first component supply path 50 is branched and transferred to the plurality of first component supply paths 52 and 53 along the flow path. In addition, the second component injected through the second component supply path (51) is branched and transferred to the plurality of second component supply paths (54, 55, 56) along the flow path. The polymers passing through the second separating distribution plate S2 are transported to the third separating distribution plate S3 located below.

The first component supplied through the first component supply paths 52 and 53 is connected to the first component supply paths 60, 61, 62, 63, 67, 68, 69, 70 along the flow path. Similarly, the second components injected through the second component supply paths 54, 55 and 56 are respectively connected to the second component supply paths 57, 58, 59, 64, 65, 66 , 71, 72 and 73 along the flow path. The first component introduced through the first component supply passages 60 and 67 of the first component supply passages formed in the third pickling distribution plate S3 is supplied to the first component supply passages 60 and 67, To the first flow path 74 of the first flow path 74. Likewise, the first component injected through the second component supply paths 57, 64 and 71 of the second component supply paths formed in the third pickling distribution plate S3 flows through the second component supply path 57, To the second one of the first and second flow paths (75). In this way, the first component transferred through the first component supply paths of the third holding distribution plate S3 is distributed to the odd-numbered flow paths 74, 76, 78, 80 of the fourth holding distribution board S4 And the second component transferred through the second component supply paths of the third component distribution plate S3 is transferred to the even flow channels 75, 77, 79 of the fourth component distribution plate S4. Whereby the first component and the second component can be alternately stacked. According to the above-described principle, the lower portion of the fourth housing distribution plate S4 may further include a separation plate (not shown) perpendicular to the flow direction of the fourth housing distribution plate and having a larger number of flow channels, It is obvious to those skilled in the art to extend the number of channels by the number. On the other hand, the first component transferred through the odd-numbered flow paths 74, 76, 78, 80 of the fourth bundled distribution plate S4 is divided into the odd-numbered flow paths 81, And the second component transferred through the even-numbered flow paths 75, 77 and 79 of the fourth holding distribution plate S4 is transferred to the fifth holding distribution plate 82, 84, 86, 88, 90, 91, 92 of the first to fifth flow paths S5, S5. Fig. 9 is a bottom view of the slit-type push-pulling apparatus of Fig. 8, and the outlet of the fifth pick-up distributing board S5 is integrally formed with a slit-type not separated by a hole type. Whereby the first component and the second component form respective layers. Therefore, the number of layers of the multilayer composite stream can be determined according to the number of slits in the fifth holding distribution board S5. The number of preferable layers may be 100 or more, more preferably 150 or more, more preferably 200 or more, and most preferably 300 or more. Thereafter, the multilayer composite flow is discharged through the discharge port 94 of the sixth holding distribution plate. 11 is a cross-sectional view of a multilayer composite flow, in which the first component 100, 102 and the second component 101, 103 are alternately laminated. In this case, one of the first component 100 and the deposited second component 101 can be defined as a repeating unit, and one compound stream includes a plurality of repeating units.

8-10 illustrate an example of a cowling distribution plate that can be used in a slit-type pushing-out apparatus that can be used in the present invention. In order to manufacture a multi-layer composite stream in which a first component and a second component are alternately stacked, It is obvious that a person skilled in the art will appropriately design and use the number, structure, size and shape of the holding hole, the slit size of the fifth holding distribution plate, and the size of the discharge port. On the other hand, the diameter of the slits in the bottom view of the fifth housing distribution plate may be 0.17 to 0.6 mm, and the diameter of the discharge port may be 5 to 50 mm, but the present invention is not limited thereto. The diameter of the slit and the like are well known to those skilled in the art.

On the other hand, the plurality of multi-layer composite streams have different optical thicknesses, the number of repeating units, etc. of the repeating units of alternately stacked first and second components forming different multi-layer composite streams to cover different wavelength ranges of light, can do. For this purpose, the size of the spinneret, the thickness of the slit, the shape, or the number of layers may be different from each other in each multilayer extrusion opening. The reflection type polarizing film finally manufactured through the spreading and stretching processes has a plurality of repeating units stacked to form one group, and each group can be set to have an average optical thickness different from each other.

More specifically, the optical thickness means n (refractive index) x d (physical thickness). Therefore, if two multilayer composite streams are formed, the optical thickness is proportional to the physical thickness (d) if there is no difference in refractive index between the first and second components of the multi-layer composite stream. Therefore, by varying the average value of the physical thickness (d) of the repeating units of the first component and the second component contained in each of the multi-layer composite streams, it is possible to derive the difference in optical thickness between the multi-layer composite streams. For this purpose, the thickness of the slits included in the slit-type extrusion opening can be designed differently for each extrusion opening, thereby making it possible to produce multi-layer composite streams having different average optical thicknesses.

 On the other hand, in order to cover the entire visible light region, the average optical thickness of the multilayer composite flow must be determined so as to correspond to various light wavelengths. For example, in order to set the average optical thicknesses of the repeating units of the multi-layer composite stream such that three complex streams are formed and correspond to 450 nm, 550 nm and 650 nm of the wavelength range of each light, the average optical thickness May be at least 5% different, more preferably at least 10% different. This allows reflection of the S wave in the entire visible region. In this case, the thicknesses of the first component and the second component forming the same repeating unit may be the same.

 Also, the number, the cross-sectional area, the shape, the diameter of the slit, and the like of the spinneret holes may be the same or different in the slit-type extrusion nozzle forming one multilayer composite flow. Furthermore, the optical thickness of the repeating units forming the same multi-layer composite stream may have a deviation of preferably within 30%, more preferably within 20%, and even more preferably within 15% of the average optical thickness. For example, if the average optical thickness of the repeating units of the first multi-layer composite stream is 200 nm, the repeating units forming the same first multi-layer composite stream may have an optical thickness variation within about 20%. On the other hand, the wavelength of light and the optical thickness are defined by the following relational expression (1).

[Relation 1]

λ = 4nd

Where? Is the wavelength of light (nm), n is the refractive index, d is the physical thickness (nm)

Therefore, when the optical thickness (nd) deviates, it is possible to cover not only the wavelength of the target light but also the wavelength range of the light including the target, thereby greatly improving uniform optical properties. On the other hand, d means the thickness of one layer, and since the repeating unit is composed of two layers of the first component and the second component, if the physical thicknesses of the first component and the second component are the same, Can be defined according to the following relation (2).

[Relation 2]

? = 2 (n ₁ d ₁ + n ₂ d ₂ )

(Nm), n ₁ is refractive index of one layer, n ₂ is refractive index of two layers, d ₁ is physical thickness of one layer (nm), and d ₂ is physical thickness of two layers (nm).

 The deviation of the optical thickness described above can be attained through imparting a deviation to the number, the cross-sectional area, the shape, the diameter of the slit or the like of the fixing hole in one slit-type extrusion mouth, or naturally achieved through a fine pressure distribution in the spreading process or the like You can.

Therefore, the plurality of multi-layered composite streams of the present invention can cover the entire visible light region by setting the average optical thicknesses of the repeating units constituting the composite stream differently, It is possible to reflect an S wave in a wide wavelength range by giving a deviation. Further, although FIGS. 8 to 10 illustrate the production of one multilayer composite stream in one slit-type extrusion slot, sections are added to the inside of the slit-type extrusion slot to produce a plurality of multi-layer composite streams, Is also included in the scope of the present invention corresponding to the integral slit-type extrusion mouthpiece. In addition, the thickness of the slit included in the slit-type extrusion slot can be designed differently for each extrusion slot to produce multi-layer composite streams having different average optical thicknesses.

 According to another preferred embodiment of the present invention, the first component conveyed in the extrusion part between steps (1) and (2) may include a plurality of components having different ejection amounts to have different average optical thicknesses 1 pressing means, respectively, into different slit-type extrusion ports. Specifically, FIG. 12 is a schematic diagram including a first pressing means for forming two multi-layered composite streams, in which a first component transferred from an extrusion portion (not shown) And is separately supplied to each of the slit-shaped extrusion ports 132, 133 in each of the first pressurizing means 130, 131. In this case, the first pressurizing means 130 and 131 have different discharge amounts, and an area difference occurs. When the slits 132 and 133 have the same specifications (when the diameters of the slits are the same) The average optical thickness of the first multi-layer composite stream and the second multi-layer composite stream formed through the second multi-layer composite stream may be different.

To this end, the discharge amount of the first pressurizing means 130 and 131 may be preferably 1 to 100 kg / hr, but is not limited thereto.

On the other hand, one first pressing means feeds the first component to the two slit-type push-pull corners and the two multi-layer composite streams formed by the two slit-type push-pull cores are joined to form one multi-layer composite stream, It is also possible that a group is formed. In this case, the final reflection type polarizing film may be formed of four groups through four first component pressing means and eight slit-type pressing and detaching mechanisms. It is also possible that one of the first pressing means transports the first component to three or more slit-shaped push-pull tabs.

According to another preferred embodiment of the present invention, the second component conveyed in the extrusion part between the step (1) and step (2) includes a plurality of components having different discharge amounts in order to have different average optical thicknesses Respectively, through the two pressing means. Specifically, FIG. 13 is a schematic diagram including two second pressing means for forming two multi-layer composite streams, in which a second component transferred from an extrusion (not shown) And is separately supplied to each of the slit-shaped extrusion seats 142, 143 in each of the second pressurizing means 140, 141. At this time, the first pressurizing means 150 and 151 have different discharging amounts, and through which the slits 152 and 153 have the same specifications (when the shape diameters of the supply conduits, etc. are the same) Layer composite stream and the second component of the second multi-layer composite stream may have different average optical thicknesses. For this, the discharge amount of the second pressing means 150 and 151 may be preferably 1 to 100 kg / hr, but is not limited thereto.

On the other hand, one second pressurizing means feeds the second component to the two slit-type extrusion drills, and the two multi-layer composite streams formed in the two slit-type extrusion drums are joined to form one multi-layer composite stream, It is also possible that a group is formed. In this case, the final reflection type polarizing film may be formed of four groups through four second component pressing means and eight slit-type extrusion / detaching mechanisms. It is also possible that one second pressing means transports the second component to three or more slit-shaped extrusion orifices.

In the next step (3), the two or more multilayer composite streams are combined into one to form a core layer. Specifically, FIG. 14 is a schematic view showing a laminated portion of a multi-layer composite flow, in which a plurality of multi-layer composite flows 161, 162, 163, and 164 manufactured through respective slit- Lt; / RTI > Meanwhile, the lapping step may be performed in a separate place, or in a case where an integral slit-type extrusion / detaching unit is used, the laminating unit may be joined together through a separate collecting / collecting distribution plate. When the number of the multi-layered composite streams is large, it is also possible to perform a multi-stage laminated structure in which some multi-layer composite streams are first lapped and lapped again to facilitate laminating. On the other hand, it is also possible that the skin layer component is laminated simultaneously or sequentially on the core layer with the core layer.

Meanwhile, a separate preliminary spreading step may be further carried out between the steps (2) and (3) or between the steps (3) and (4) to facilitate the spreading of the repeating units described below.

Next, in step (4), at least one side of the core layer laminated is joined with the skin layer component transferred from the extrusion part. 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. On the other hand, if the skin layer components are laminated at the same time or the skin layer is not formed as described above, this step may be omitted.

Next, in step (5), the skin layer is spread and the core layer is spread in the flow control part. Specifically, Figure 15 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 16 is a side view. The degree of spreading of the core layer can be appropriately adjusted to adjust the repeating unit to have an optical thickness suitable for reflecting light of a desired wavelength. This can be suitably designed in consideration of further reducing the optical thickness in the subsequent stretching process. Specifically, in FIG. 15, since the core layer having the skin layer sandwiched therebetween is spread widely from side to side in the coat-hanger die, the first component contained therein also spreads to the left and right. Also, as shown in the side view of FIG. 16, the coat hanger die is widely spread to the left and right but has a structure of shrinking up and down, so that the skin layer purges horizontally in the laminated core layer and shrinks in the thickness direction. This is based on Pascal's principle, in which the fluid in the enclosure is guided to spread widely in the width direction by the principle that the pressure is transmitted to the fine portion by a certain pressure. Therefore, the outlet size is wider in the width direction than the die inlet size, and the thickness is reduced. This requires the use of the Pascal principle in which the molten liquid material can flow and shape controlled by pressure in a closed system, preferably a polymer flow rate and viscosity induction such that a flow of laminar flow of less than 2,500 Reynolds numbers is preferred. When the flow of the turbulent flow is 2,500 or more, the induction of the plate-like type becomes uneven, and there is a possibility that the optical characteristic is varied. The left and right die width of the outlet of the coat-hanger die may be between 800 and 2,500 mm and the fluid flow of the polymer is required to regulate the pressure so that the Reynolds number does not exceed 2,500. The reason is that the polymer flow becomes turbulent and the arrangement of the cores may be disturbed. Also, the internal temperature may be 265 to 310 ° C.

The flow control unit may be a T-die or a manifold type Coat-hanger die capable of inducing the spread of the repeating unit, but is not limited thereto, and may be used without limitation as long as it can induce spreading of the core layer.

The manufacturing method of the present invention requires a separate adhesive layer and / or a protective layer (PBL) in the core layer since a plurality of multi-layer composite streams having different average optical thicknesses are manufactured using a plurality of composite extrusion / It is possible to reflect all of the S waves in the visible light wavelength range. Also, since the skin layer is formed on at least one surface of the core layer in a molten state, the skin layer is not subjected to a separate adhesion step. This makes it possible to remarkably reduce the manufacturing cost and to maximize optical properties at a limited thickness.

According to a preferred embodiment of the present invention, after the step (5), (6) cooling and smoothing the spreader-induced polarizer transferred from the flow controller, (7) stretching the polarizer through the smoothing step ; And (8) opening and fixing the stretched polarizer.

As a step of cooling and smoothing the polarizer fed from the flow control unit as the step (6), the smoothing step may be performed by cooling and solidifying the polarizer used in the manufacture of a conventional reflective polarizer, and then casting the same.

Thereafter, a step of stretching the polarizer through the smoothing step is performed. The stretching may be performed through a conventional stretching process of a reflective polarizer, thereby causing a refractive index difference between the first component and the second component to cause a light modulation phenomenon at the interface, and the stretch- The optical thickness corresponding to the desired wavelength range is finally obtained. Therefore, in order to adjust the optical thickness of the repeating unit in the final reflective polarizer, it can be appropriately set in consideration of the slit diameter, spreading inducing condition, and stretching ratio of the slit-type extrusion / 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 can be performed in the longitudinal direction. 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, when stretching under appropriate temperature conditions, polymer molecules may be oriented so that the material becomes birefringent.

Next, as a step (8), the final reflective polarizing film can be manufactured through a step of 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.

On the other hand, in the present invention, when the average optical thickness of the target repeating unit between groups is determined, it is possible to manufacture the reflective polarizing film of the present invention by appropriately controlling the slit size, the size of the flow control unit, will be.

According to another preferred embodiment of the present invention, there is provided an apparatus for manufacturing a multilayer reflective polarizer including a core layer in which a first component and a second component are alternately stacked and a skin layer formed on at least one surface of the core layer, Three or more extruders into which the one component, the second component, and the skin layer component are separately introduced; Layered composite streams in which the repeating units of the first component and the second component are alternately stacked, and each of the multi-layer composite streams includes a plurality of multi- A spin block including a composite extrusion nozzle for injecting a first component and a second component to produce two or more multi-layer composite streams having different average optical thicknesses of the repeating units; A collection block for forming a core layer by laminating two or more multi-layer composite streams transferred from the spin block part; A feed block part communicating with the extruder into which the skin layer component is injected and joining the skin layer to at least one surface of the core layer conveyed in the collection block part; And a flow control unit for guiding the spread of the core layer to which the skin layer conveyed in the feed block unit leads the spreading of the core layer.

17 is a schematic view of an apparatus for manufacturing a multilayer reflective polarizer in which a skin layer and a core layer are integrally formed according to a preferred embodiment of the present invention. Specifically, the first extrusion part 220 into which the first component is injected, the second extrusion part 221 into which the second component is injected, and the third extrusion part 222 into which the skin layer component is injected. The first extrusion part 220 is connected to the spin block part C including the four slit type extrusion tools 223, 224, 225 and 226. At this time, the first extruding unit 220 supplies the first component to the four slit-type extrusion seats 223, 224, 225, and 226 in a molten state. The second extruded portion 221 is also connected to the spin block portion C and supplies the second component to the four slit-shaped extrusion orifices 223, 224, 225, and 226 contained therein in a molten state. The four components of the multi-layer composite stream are alternately stacked with the first component and the second component through the four slit-type extrusion ports 223, 224, 225, and 226, and the average optical thicknesses of the repeating units are different. For this purpose, the respective slit diameters of the four slit-shaped extrusion ports may be different. The four slit-shaped pushing-in prongs 223, 224, 225 and 226 may be the slit-type pushing-out prongs shown in Fig. In addition, although four slit-type extrusion / detachment mechanisms have been described as an example, it is also within the scope of the present invention that a single slit-type extrusion / detachment mechanism can be used. The four multi-layer composite streams produced through the four slit-shaped extrusion ports 223, 224, 225 and 226 are joined together in the collection block section 227 to form one core layer. In this case, the collection block portion 227 may be formed separately or may be combined with the multi-layer composite streams in the form of a bundle of nuts in the slit-type extrusion slot when a single slit-type extrusion slot is used. The core layer laminated in the collection block portion 227 is conveyed to the feed block portion 228 and then joined with the skin layer component conveyed from the third extrusion portion 222. Therefore, the third extrusion portion 222 and the feed block portion 228 can communicate with each other. Thereafter, the core layer having the skin layer laminated thereon is transferred to the flow control section 229 and the spread of the first component is induced. Preferably, the flow control may be a T-die or a coat-hanger die. On the other hand, when the skin layer and the core layer are laminated together, the third extruding portion 222 can communicate with the collection block portion 227, in which case the feed block portion 228 can be omitted.

18 is a schematic view of an apparatus for producing a reflective polarizer in which a polymer is dispersed according to another preferred embodiment of the present invention. 17, the first extruding unit 220 feeds the first component to the four first pressing units 233, 234, 235, and 236. The first pressurizing means 233, 234, 235 and 236 have different discharge amounts and discharge the first component into the plurality of slit-shaped extrusion ports 241, 242, 243 and 244. The second extruding portion 221 feeds the second component to the four second pressing means 237, 238, 239, 240. The second pressurizing means 237, 238, 239 and 240 have discharge amounts different from each other and discharge the second component to the plurality of slit-shaped extrusion ports 241, 242, 243 and 244. Four multi-layer composite streams having different average optical thicknesses are produced through four slit-type extrusion ports 241, 242, 243, and 244. The first pushing means, the second pushing means, and the plurality of slit-shaped pushing-out portions form a spin block portion (C).

19 is a schematic diagram of an apparatus for producing a reflective polarizer in which a polymer is dispersed according to another preferred embodiment of the present invention. 18, in order to manufacture a multilayer reflective polarizing film having four groups, eight slit-type extrusion / detaching mechanisms are used instead of four slit-type extrusion / have. Specifically, the first pressing means 233 discharges the first component to the two slit-shaped pushing-out portions 250, 251. The second pressing means 234 also discharges the first component to the two slit-shaped pushing-out portions 250, 251. The two slit-shaped extrusion ports 250 and 251 have the same average optical thickness between the multilayer composite streams since the first component and the second component are transported through the same first pressing means and second pressing means. In this way, eight multi-layer composite streams are formed and the two multi-layer composite streams have the same average optical thickness. The two multilayer composite streams having the same average optical thickness are laminated in the first leg portions 258, 259, 260, and 261 to form four multi-layer composite streams, respectively, and the four multi- ) To form one core layer.

On the other hand, in FIG. 19, although it has been described that one first pressing means transfers the first component to two slit-type extrusion seals, it is possible to transfer the first component to two or more slit- And this can be equally applied to the second pressing means.

In the present invention, the use of the reflective polarizing film has been 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.

On the other hand, the specific structure and effects of the multilayer reflective polarizing film having the specific structure used in the present invention are described in Korean Patent Application No. 2011-0145856 as a reference.

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 >

Specifically, a mixture of PEN having a refractive index of 1.65 as a first component and dimethyl terephthalate and dimethyl-2,6-naphthalene dicarboxylate as a second component in a molar ratio of 6: 4 was mixed with ethylene glycol (EG) and 1 : 2 molar ratio of co-PEN having a refractive index of 1.64 were charged into the first extruder and the second extruder, respectively. The extrusion temperature of the first component and the second component was 295 캜, and Cap. The polymer flow was calibrated through adjustment and the skin layer was subjected to an extrusion process at a temperature level of 280 占 폚.

Four composite slurries having different average optical thicknesses were prepared by using four slit-type extrusion pots shown in Figs. Specifically, the first component transferred from the first extruder is distributed to the four slit-type extrusion drills, and the second component transferred from the second extruder is transferred to the four slit-type extrusion drills. One slit-type extrusion slot is composed of 300 layers. The thickness of the slit of the first slit-type extrusion slot on the bottom of the fifth slotted distribution plate of Fig. 9 is 0.26 mm, the slit thickness of the second slit-type extrusion slot is 0.21 mm , The slit thickness of the third slit-type extrusion nozzle was 0.17 mm, the slit thickness of the fourth slit-type extrusion nozzle was 0.30 mm, and the diameter of the discharge port of the sixth nozzle distribution plate was 15 mm 15 mm. Four composite streams discharged through the four slit-type extrusion ports were transported through a separate flow path and then lapped in a collection block to form one core layer polymer. The spread of the core layer polymer was induced in the coat hanger die of Figs. 15 and 16, 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 960 mm, the thickness is 0.78 mm, and the flow rate is 1 m / min. Then, a smoothing process was performed on the cooling and casting rolls and stretched 6 times in the MD direction. Followed by heat setting at 180 캜 for 2 minutes through an IR heater to produce a multilayer reflective polarizer. The refractive index (nx: 1.88, ny: 1.64, nz: 1.64) of the first component of the produced reflective polarizer was 1.64 and the refractive index of the second component was 1.64. The A group had 300 layers (150 repetition units), the thickness of the repeating unit was 168 nm, the average optical thickness was 275.5 nm, and the optical thickness variation was about 20%. The B group had 300 layers (150 repetition units), the thickness of the repeating unit was 138 nm, the average optical thickness was 226.3 nm, and the optical thickness variation was about 20%. The C group had 300 layers (150 repetition units), the thickness of the repeating unit was 110 nm, the average optical thickness was 180.4 nm, and the optical thickness variation was about 20%. The D group had 300 layers (150 repetition units), the thickness of the repeating unit was 200 nm, the average optical thickness was 328 nm, and the optical thickness variation was about 20%. The thickness of the core layer of the manufactured multilayer reflective polarizer is 92.4 탆.

Thereafter, a UV-curable adhesive was applied to one surface of the light-diffusing film, and then the above-prepared reflective polarizing film was attached to produce an integral optical film.

Since the reflective polarizing film 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 (15)

Light control film and
A multilayer reflector including a first layer having in-plane birefringence and a second layer alternately laminated with the first layer, the multilayer reflector being integrally bonded to the light control film and transmitting the first polarized light irradiated from the outside and reflecting the second polarized light, Type polarizing film;
Wherein the first layer and the second layer are different in refractive index in at least one axial direction and the first layer and the second layer are elongated in at least one axial direction, The two layers form one repeating unit, and the repeating units form a group for reflecting a transverse wave of a desired wavelength (S wave), and the groups are two or more, the groups are integrally formed, Lt; RTI ID = 0.0 > 1, < / RTI > wherein the average optical thickness of the units is different. The method according to claim 1,
Wherein the light control film is a light diffusion film or a prism film. The method according to claim 1,
And an adhesive layer between the reflective polarizing film and the light control film. The integrated polarizing film of claim 1, wherein the repeating units form three groups for reflecting light in three wavelength bands. The integrated polarizing film according to claim 1, wherein the repeating units form three groups for reflecting light in four wavelength bands. The integrated polarizing film of claim 1, wherein the desired wavelength comprises a visible light band. The method according to claim 1,
Wherein the optical thickness of the repeating units included in the same group has a thickness variation within 30% of the average optical thickness. The method according to claim 1,
Wherein the optical thicknesses of the repeating units included in the same group have a thickness variation within 20% of the average optical thickness. 5. The monolithic polarizing film of claim 4, wherein the three reflection bands include wavelength bands of 450 nm, 550 nm and 650 nm. 6. The monolithic polarizing film of claim 5, wherein the four reflection bands include wavelength bands of 350 nm, 450 nm, 550 nm and 650 nm. 2. The monolithic polarizing film of claim 1, wherein the plurality of groups are different in average optical thickness of the repeating units by 10% or more. The integrated polarizing film according to claim 1, wherein the number of repeating units contained in one group is 150 or more. 2. The method according to claim 1, wherein the refractive indexes of the first layer and the second layer are 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 is 0.1 or more. film. The method according to claim 1,
And a skin layer integrally formed on at least one side of the core layer. The method according to claim 1,
And an adhesive layer is not formed between the group and the group and between the core layer and the skin layer.

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