KR20160082454A - Complex reflective polarized light film - Google Patents

Abstract

The present invention relates to a complex reflective polarizing film. More specifically, the present invention relates to a complex reflective polarizing film which minimizes an optical loss, has excellent reliability even in a module manufacturing process of a display or the like or in a using environment of high temperature and humidity while having excellent brightness, has an excellent exterior quality, and has significantly excellent color reproduction. The complex polarizing film comprises a light diffusion layer and a reliability support layer.

Description

Complex reflective polarized light film < RTI ID = 0.0 >

The present invention relates to a composite reflective polarizing film, and more particularly to a composite reflective polarizing film which minimizes light loss, has excellent brightness, is excellent in reliability even in a module manufacturing process of a display or the like or in a high temperature / high humidity environment during use, And has remarkably excellent color reproducibility.

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 at least 50% of the light emitted from the backlight is absorbed by the back side optical film (absorption type polarizing film). Thus, a reflective polarizing film may be provided between the optical cavity and the liquid crystal assembly to enhance the utilization efficiency of the backlight in the liquid crystal display.

The reflective polarizing film prevents the optical performance from deteriorating due to light loss and slimes the reflective polarizing film according to the thickness of the display panel that is slimmer. The reflective polarizing film can be manufactured in a simple manner of manufacturing process, minimization of defects in the manufacturing process, Continuous research is continuing.

1 is a diagram showing the optical principle of a conventional reflective polarizing film. Specifically, 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, Direction 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, and is then transmitted to the liquid crystal assembly.

The selective reflection of the S polarized light and the transmission of the P polarized light to the incident light of the reflective polarizing film are carried out 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 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 the incident polarized light is transmitted to the liquid crystal assembly. On the other hand, the reflected S-polarized light is reflected in a randomized state in the diffusive reflection plane of the optical cavity as described above, and is transmitted to the reflective polarizing film again. 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 such a structure that an isotropic optical layer and an anisotropic optical layer having different refractive indexes are alternately laminated and stretched to have optical thickness and refractive index between each optical layer that can be optimized for selective reflection and transmission of incident polarized light. There is a problem that the manufacturing process of the reflective polarizing film is complicated. Particularly, since each optical layer of the reflective polarizing film 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 the incident polarized light, so that the number of stacked layers of the optical layer excessively increases 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 polarizing film (DBEF). Specifically, in the multilayer reflective polarizing film, the skin layers 9 and 10 are formed on both sides of the substrate 8. The substrate 8 is divided into four groups (1, 2, 3, 4), where each of the isotropic and anisotropic layers is alternately layered 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 polarizing film included in the display panel is limited in thickness of the base material in order to make it slim, when an adhesive layer is formed on the base material and / or the skin layer, the base material 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 for producing the above conventional multilayer reflective polarizing film 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, And then 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 reflection type polarizing film are frequently released even when the decrease in luminance is reduced in terms of cost reduction.

Thus, a reflective polarizing film is proposed in which a birefringent polymer stretched in the longitudinal direction is arranged inside a substrate instead of a multilayer reflective polarizing film, and a dispersion capable of achieving the function of the reflective polarizing film is dispersed. Fig. 3 is a perspective view of a reflective polarizing film 20 including a rod-shaped polymer, in which birefringent polymers 22 stretched in the longitudinal direction are arranged in one direction in 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 reflective polarizing film. However, as compared with the above-described alternately stacked reflective 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 laminated reflective polarizing film, there has been a problem in that an excessive number of birefringent polymers 22 must be disposed in the substrate. Specifically, in order to have optical properties similar to those of the above-described laminated reflective polarizing film 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 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. 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 polarizing film, a problem that a bright line appearance is observed due to the space between the layers and the space between the dispersion bodies has occurred.

As described above, the reflective polarizing films proposed so far have all the disadvantages. Particularly, the multi-layer reflective polarizing films have a problem in that the production cost is remarkably high because they are used in actual products, The polymer dispersion type reflective polarizing film in which the polymer is dispersed in the substrate may be more preferable because of problems such as poor quality due to the intervention of foreign matter generated during production, complexity of the manufacturing process, and reduction of brightness due to a very large amount of adhesive layer .

However, since the polymer dispersed type reflective polarizing film developed up to now has a translucency of the base material and foreign objects are displayed on the outer surface of the film, the defect ratio of the appearance is large, and the light leakage, the bright line appearance phenomenon, the narrow viewing angle, Is lowered.

In addition, there is a problem that the reliability is remarkably reduced due to bending of the reflective polarizing film due to high heat conditions applied in a process of manufacturing a reflective polarizing film as a module such as a backlight unit and / or heat generated in an environment where such a module is used there was.

Furthermore, in order to solve such a problem, the composite film obtained by adding a separate structure to the polymer-dispersed reflective polarizing film can not solve the problem of lowering the reliability of the reflective polarizing film. There is a problem in that luminance is significantly reduced at the same time. If the decrease in brightness is minimized, it is difficult to prevent the appearance of foreign objects in appearance, and the total thickness of the optical film included in the backlight unit or the like is increased due to the separate structure, It was impossible to satisfy all of the properties simultaneously. Furthermore, since a separate configuration is required to be inserted one by one into the backlight unit or the normal display manufacturer, the manufacturing cost is increased and the production time is prolonged.

Disclosure of the Invention The present invention has been conceived in order to solve the above-described problems, and it is an object of the present invention to provide a light emitting device which minimizes light loss and has excellent brightness, is excellent in reliability in a module manufacturing process of a display or the like or in a high temperature / And a composite reflective polarizing film capable of remarkably improving color reproducibility and realizing a very slim display and capable of drastically improving the manufacturing process, manufacturing cost and manufacturing time of a display including a backlight unit.

According to an aspect of the present invention, there is provided a composite reflective polarizing film comprising a reflective polarizing film in which a polymer is dispersed in a substrate, the composite reflective polarizing film comprising: a light-diffusing layer formed on an upper surface of a reflective polarizing film; And a reliable supporting layer formed on the lower surface of the reflective polarizing film, wherein the thickness of the reflective polarizing film and the thickness of the reliability supporting layer satisfy the following relational expression (1).

[Relation 1]

According to a preferred embodiment of the present invention, the light-diffusing layer may be formed by curing a photo-curable polymer resin or a thermosetting polymer resin including at least one polymer resin.

According to another preferred embodiment of the present invention, the light diffusion layer may include at least one fine pattern 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, the fine pattern may include a microlens.

According to another preferred embodiment of the present invention, the light-diffusing layer may include a bead coating layer.

According to another preferred embodiment of the present invention, the reliability supporting layer may be a polyester film stretched in at least one direction.

According to another preferred embodiment of the present invention, a first primer layer for enhancing adhesion between the reflective polarizing film and the reliable supporting layer may be further included.

According to another preferred embodiment of the present invention, the reliability supporting layer may have a coefficient of thermal expansion of 4 to 35 μm / m · ° C. at a temperature of 70 to 80 ° C.

According to another preferred embodiment of the present invention, the reflective polarizing film includes a base material and a plurality of dispersing bodies contained in the base material, the plurality of dispersing materials transmitting the 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 base material have different refractive indexes in at least one axial direction from the base material, 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 is included in at least three groups according to the cross-sectional area, the first group of the disperse bodies of the group is 0.2 to 2.0 탆 ² , and the second group dispersion of the cross-sectional area is less than ² 5.0㎛ from 2.0㎛ ^2, greater than the cross-sectional area of the dispersion according to the third group is ² or less from 10.0㎛ 5.0㎛ than ^2, the dispersion of the first group to third group is randomly It can yeoldoel.

According to another preferred embodiment of the present invention, the reflective polarizing film comprises: a core layer including a base material and a plurality of dispersants contained in the base material; And an integrated skin layer formed on at least one side of the core layer.

According to another 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 dispersions of the first group among the dispersions having the aspect ratio of 1/2 or less may be 30 to 50%, and the number of dispersoids of the third group may be 10 to 30% .

According to another preferred embodiment of the present invention, the ratio of the number of dispersions of the first group to the number of dispersions of the third group among the dispersions having the aspect ratio of 1/2 or less may be 3 to 5: 1.

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 reflective polarizing film may be stretched in at least one axial direction.

According to another preferred embodiment of the present invention, the thickness of the reflective polarizing film and the thickness of the reliability supporting layer may satisfy the following relational expression (2).

[Relation 2]

According to another preferred embodiment of the present invention, the haze value of the composite reflective polarizing film may be 65% or more.

According to another aspect of the present invention, there is provided a composite reflective polarizing film comprising a reflective polarizing film in which a polymer is dispersed in a substrate, the composite reflective polarizing film comprising: a reliable supporting layer formed on an upper surface of the reflective polarizing film; And a light diffusion layer formed on the upper surface of the reliability supporting layer, wherein the thickness of the reflective polarizing film and the thickness of the reliability supporting layer satisfy the following relational expression (1).

[Relation 1]

In order to solve the above problems, the present invention provides a backlight unit including a composite reflective polarizing film according to the present invention.

Further, in order to solve the above-described problems, the present invention provides a liquid crystal display device including a backlight unit according to the present invention.

Hereinafter, terms used in this specification will be described.

As used herein, the term " the dispersant has birefringence "means that, when light is irradiated to fibers having different refractive indexes along the direction, the light incident on the dispersant is refracted into two or more lights having different directions.

As used herein, the term "isotropic" means that, when light passes through an object, the refractive index is constant regardless of the direction.

As used herein, the term "anisotropy" means that the optical properties of an object are different depending on the direction of light, and an anisotropic object has birefringence and corresponds to isotropy.

The term "optical modulation" as used herein means that the irradiated light reflects, refracts, scatters, changes the intensity of light, the period of waves, or the nature of light.

As used herein, the term "aspect ratio" means the ratio of the minor axis length to the major axis length based on the vertical cross section in the longitudinal direction of the dispersion.

As used herein, the terms spatially relative, "below", "beneath", "lower", "above", " And can be used to easily describe a correlation between one component and other components as shown in the drawings. Spatially relative terms should be understood in terms of the directions shown in the drawings, including the different directions of components at the time of use or operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element . Thus, the exemplary term "below" can include both downward and upward directions. The components can also be oriented in different directions, so that spatially relative terms can be interpreted according to orientation.

Also, these spatially relative terms "upper," "upper," "upper," "lower," "lower," and "lower" include both the meaning of "directly" and "indirectly".

The composite reflective polarizing film according to the present invention minimizes light loss, has excellent brightness, and is excellent in reliability in a module manufacturing process of a display or the like or in a high temperature / humidity environment during use, has excellent film appearance quality, It is possible to realize an excellent and highly slim display, and the manufacturing process, manufacturing cost and manufacturing time of the display including the backlight unit can be remarkably improved.

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 reflective polarizing film including a bar-shaped polymer.
4 is a cross-sectional view showing a path of light incident on a birefringent graphite sheet used for a reflective polarizing film.
5 is a cross-sectional view of a composite reflective polarizing film according to a preferred embodiment of the present invention.
6 is a cross-sectional view of a reflective polarizing film in which a dispersion is randomly dispersed in a substrate according to a preferred embodiment of the present invention.
FIG. 7 is a longitudinal sectional view of the dispersion body used in a preferred embodiment of the present invention. FIG.
8 is a perspective view of a reflective polarizing film according to a preferred embodiment of the present invention.
9 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention.
10 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention.
11 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention.
12 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention.
13 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention.
14 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention.
15 is a cross-sectional view of a light diffusing layer in a composite reflective polarizing film according to a preferred embodiment of the present invention.
16 is a cross-sectional view of a light diffusing layer in a composite reflective polarizing film according to a preferred embodiment of the present invention.
17 is a cross-sectional view of a light diffusing layer in a composite reflective polarizing film according to a preferred embodiment of the present invention.
18 is a cross-sectional view of a composite reflective polarizing film according to a preferred embodiment of the present invention.
Figure 19 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.
Fig. 20 is a side view of Fig. 19. Fig.
21 is a schematic view of a process of forming a fine pattern according to a preferred embodiment of the present invention.
22 is a cross-sectional view showing the detailed structure of the molding part of Fig.
23 is a schematic view of a process of forming a fine pattern according to another preferred embodiment of the present invention.
24 is a schematic view of a process of forming a fine pattern according to another preferred embodiment of the present invention.
25 is a cross-sectional view of a laminated reflective film and a reliable support layer according to a preferred embodiment of the present invention.
26 is a cross-sectional view of a liquid crystal display device according to a preferred embodiment of the present invention.
27 is a liquid crystal display device employing a composite reflective polarizing film according to a preferred embodiment of the present invention.
28 is a schematic view of an apparatus for producing a plate-shaped polymer dispersed reflective polarizing film included in a preferred embodiment of the present invention.
FIG. 29 is a perspective view illustrating a coupling structure of a separation plate of a sea-island type extrusion orifice capable of producing a plate-shaped polymer dispersed reflective polarizing film included in a preferred embodiment of the present invention.
30 is a cross-sectional view of a plate-shaped polymer-dispersed reflective polarizing film according to a preferred embodiment of the present invention.

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

As described above, in the polymer-dispersed reflective polarizing film, since the substrate is translucent and the foreign object is displayed on the outer surface of the film, the defective rate of the appearance is large, and the light leakage, bright line phenomenon, narrow viewing angle, The material of the base material in a conventional polymer-dispersed reflective polarizing film is a polycarbonate-based material, and a high thermal condition applied in a process of manufacturing a reflective polarizing film by a module such as a backlight unit and / There is a problem in that the reliability is remarkably reduced, for example, the reflection polarizing film is bent due to heat generated in an environment where the polarizing film is exposed. Furthermore, in order to solve such a problem, the composite film obtained by adding a separate structure to the polymer-dispersed reflective polarizing film can not solve the problem of lowering the reliability of the reflective polarizing film. At the same time, there is a problem that the luminance is remarkably reduced, and when the decrease in the luminance is minimized, it is difficult to prevent the appearance of foreign objects in the appearance, and all the desired physical properties can not be satisfied at the same time. Further, due to the separate configuration, the total thickness of the optical film included in the backlight unit or the like has increased, and thus, a slim display can not be realized. Further, since the backlight unit or the normal manufacturing process must be inserted one by one, There was a problem with this extension.

According to a first embodiment of the present invention, there is provided a composite reflective polarizing film comprising a reflective polarizing film in which a polymer is dispersed in a substrate, the composite reflective polarizing film comprising: a light-diffusing layer formed on an upper surface of a reflective polarizing film; And a reliable supporting layer formed on the lower surface of the reflective polarizing film, wherein the thickness of the reflective polarizing film and the thickness of the reliability supporting layer satisfy the following relational expression 1: I tried to solve it. Thereby, it is possible to minimize the optical loss and to have excellent luminance, and at the same time, there is no change in the external appearance such as film crying or wrinkling even in a module manufacturing process of a display or the like or a high heat / There is no deficiency such as appearance, light leakage, and dotted line occurrence, so that the quality is excellent and the color reproducibility can be remarkably improved.

[Relation 1]

5 is a cross-sectional view of a composite reflective polarizing film according to an exemplary embodiment of the present invention. The composite reflective polarizing film 1000 includes a light diffusing layer 100 formed on the upper surface of the reflective polarizing film 200, And a first primer layer 400 for enhancing adhesion between the reflective polarizer film 200 and the reliabilization support layer 300. The first support layer 400 may include a first support layer 400 formed on the lower surface of the film 200,

First, the reflective polarizing film 200 will be described.

The reflective polarizing film included in the preferred embodiment of the present invention can be inserted into Korean Patent Application No. 2013-0169215 and Korean Patent Application No. 2013-0169217 by the same applicant.

The reflective polarizer film 200 may be a conventional polymer-dispersed reflective polarizer film in which a polymer is dispersed in a substrate. The conventional polymer-injected reflective polarizing film may be a reflective polarizing film for a publicly known tube including a rod-shaped polymer as shown in Fig. 3. The present invention is particularly limited to the shape, the number of the polymer, I never do that.

However, as described above, the reflective polarizing film in which the polymer is dispersed in the conventional substrate has a problem that the light leakage, the bright line viewing phenomenon, the wide viewing angle are narrow, the light loss can not be minimized, and the luminance is lowered.

Accordingly, according to a preferred embodiment of the present invention, the reflective polarizing film comprises a base material and a plurality of dispersing bodies contained in the base material to transmit the first polarized light to be externally irradiated and to reflect the second polarized light, Wherein at least 80% of the plurality of dispersions contained in the substrate have different refractive indexes in at least one axial direction with respect to the substrate, and the aspect ratio of the minor axis length to the major axis length Wherein the dispersoids having an aspect ratio of 1/2 or less are contained in at least three groups according to the cross-sectional area, the first group of the dispersoids have a cross-sectional area of 0.2 to 2.0 占 퐉 ² , and the body cross-sectional area is less than ² from 5.0㎛ 2.0㎛ ^2, greater than the cross-sectional area of the dispersion according to the third group is ² or less from 10.0㎛ 5.0㎛ than ^2, the dispersion of the first group to the third group at random times It can be.

According to another preferred embodiment of the present invention, the reflective polarizing film may include an integrated skin layer formed on at least one surface of the core layer to protect the core layer.

Further, according to another preferred embodiment of the present invention, the reflective polarizing film comprises the above-described base material and the reflective polarized light including a plurality of dispersions contained in the base material and satisfying the conditions according to a preferred embodiment of the present invention The film may be a core layer and an integrated skin layer formed on at least one side of the core layer. The skin layer may further contribute to protection of the core layer.

The reflection polarizing film according to another embodiment including the skin layer and the skin layer may be different in use, and various general liquid crystal display devices such as a display may be provided with a reflection polarizing film And it may be preferable to use a reflective polarizing film not including a skin layer in a portable liquid crystal display device, for example, a portable electronic device, a smart electronic device, or a smart phone, but the present invention is not limited thereto.

On the other hand, the composite reflective polarizing film according to the present invention may include a reliable supporting layer, which will be described later, on one side of the reflective polarizing film to achieve the object of protecting the core layer without providing a skin layer for protecting the core layer.

Hereinafter, the reflective polarizing film will be specifically described with respect to the reflective polarizing film including the skin layer.

Specifically, FIG. 6 is a cross-sectional view of a reflective polarizing film in which a dispersion is randomly dispersed in a substrate according to a preferred embodiment of the present invention. A core layer 210 in which a plurality of dispersions 212 to 217 are randomly dispersed and arranged in a base material 211 and a skin layer 220 formed integrally on at least one surface of the core layer.

First, the core layer 210 will be described.

In the core layer, 80% or more of a plurality of dispersions contained in the substrate should have an aspect ratio of a minor axis length to a major axis length of 1/2 or less, more preferably 90% or more The aspect ratio value should be 1/2 or less.

Specifically, FIG. 7 is a vertical section in the longitudinal direction of the dispersion used in a preferred embodiment of the present invention, wherein the long axis length is a and the short axis length is b, and the long axis length a and the short axis length b The relative length ratio (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. 6, the first group of dispersions 202 and 203 having the smallest cross-sectional area and the second group of dispersions 204 and 205 having an intermediate cross-sectional area and the third group 206 and 207 having the largest cross- ) Are dispersed randomly. In this case, a sectional area of the first group ² 0.2 ~ 2.0㎛, the cross-sectional area of the second group is ² or less 5.0㎛ from 2.0 ㎛ ^2, greater than the cross-sectional area of the third group is ² or less 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 minimizing the light loss while maximizing the wide viewing angle, minimizing the light loss, and maximizing the luminance improvement, compared to the conventional dispersion type reflective polarizing film.

FIG. 8 is a perspective view of a reflective polarizing film according to an embodiment of the present invention. A plurality of random dispersions 208 extend in the longitudinal direction within a base material 201 of a core layer 210, 220 are formed on the top and / or bottom of the core layer 210. In this case, each of the random dispersions 208 may be elongated in various directions, but it is preferable to elongate in parallel in any one direction, more preferably, elongation in the 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 reflective polarizing film including a dispersion within a substrate, the magnitude of the substantial agreement 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, the refractive index of the refractive index of the x-axis direction of the dispersion nX _1, y is the axial refractive index nY ₁ and z-axis direction nZ _1, the refractive index of the base material nX _2, nY ₂ and nZ when _2, plane birefringence between nX ₁ and nY ₁ 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.

The thickness of the core layer in the present invention is preferably 20 to 350 占 퐉, more preferably 50 to 250 占 퐉. However, the present invention is not limited thereto. For example, Accordingly, the thickness of the core layer can be designed differently. 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.

Next, the skin layer 220 that can be included on at least one side of the core layer will be described.

The skin layer component may be a conventionally used component and is not particularly limited as long as it is used in a reflective polarizing film. Preferably, the component is polyethylene naphthalate (PEN), co-polyethylene naphthalate (co-PEN) (PS), polymethylmethacrylate (PMMA), polybutylene terephthalate (PBT), polybutylene terephthalate (PBT), and polyethylene terephthalate (PET), polycarbonate 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) Polymers may be used singly or in combination. Can be and is more preferably dimethyl-2,6-naphthalene dicarboxylate, dimethyl terephthalate and ethylene glycol, Im chroman-hexane dimethanol monomers days properly co-polymerization, such as PEN (CHDM).

According to a preferred embodiment of the present invention, the thickness of the skin layer may be 10 to 500 mu m, but is not limited thereto.

On the other hand, when the skin layer is formed, it is also integrally formed between the core layer 210 and the skin layer 220. 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 prepared simultaneously with the core layer and then the stretching process is performed, the skin layer of the present invention can be stretched in at least one axial direction, unlike the case of adhering the unstretched skin layer after stretching the conventional core layer . 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.

Next, the light-diffusing layer 100 formed on the upper surface of the reflective polarizing film 200 will be described.

The light diffusing layer 100 maximizes the light collecting effect and prevents irregular reflection on the surface, thereby remarkably improving the brightness. The haze value of the composite reflective polarizing film through scattering of light is increased, It can minimize defects. The light diffusing layer 100 may be formed on the reflective polarizing film 200 or on an adhesive layer (not shown) formed on the reflective polarizing film 200.

According to a preferred embodiment of the present invention, the light diffusion layer 100 may include a fine pattern. The fine pattern is not particularly limited as far as it is a fine pattern capable of improving brightness and improving the light collecting effect, but more preferably the fine pattern is composed of a prism, a lenticular, a microlens, a triangular pyramid and a pyramid pattern , And each of the patterns may be formed by forming a pattern alone or in combination, more preferably, it may be any one or more of a lenticular, a microlens, and a prism, and more preferably, May be a microlens capable of simultaneously satisfying all physical properties.

Specifically, FIG. 9 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention. In the reflective polarizing film 200, a plurality of dispersing bodies are elongated in the longitudinal direction of the substrate 200, . 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. The light diffusing layer 100 formed on the reflective polarizing film 200 can perform an enhanced light converging function and a brightness enhancing function by including a fine pattern. FIG. 9 shows a light diffusing layer 110 including a lenticular pattern, .

To describe the lenticular pattern more specifically, the height h of the lenticular may be 10 to 50 탆. If the height of the lenticular pattern is less than 10 탆, the pattern may be difficult to implement. If the height of the lenticular pattern is more than 50 탆, the brightness may decrease due to an increase in the total amount of light.

Further, the pitch 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 defined as c and the long axis radius is defined as d per lenticular lens, the ratio of the major axis / minor axis (b / a) can be 1.0 to 3.0. If the ratio of the long axis / short axis (d / c) is out of the above range, there is a problem that the luminance line concealing efficiency for 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 ends of the lower end of the lens must satisfy the range of 30 to 80 degrees. At this time, if? Is less than 30 占 the bright line concealing efficiency is lowered, and if? Is greater than 80 占 there is a problem that it becomes difficult to manufacture the lens pattern. When the sectional shape of the lenticular lens is triangular, it is preferable that the vertex angle &thetas; satisfies 90 to 120 DEG for the hue line concealment effect.

In addition, the lenticular shape may be formed as a pattern having the same height and pitch as shown in Fig. 9, or lenticular patterns 111 having different heights and pitch as shown in Fig. 10 may be mixed.

Meanwhile, FIG. 11 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention, wherein the light diffusion layer 112 includes a microlens pattern. To describe the microlens pattern specifically, the height of the microlens may be 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.

Also, the microlens patterns may be formed in a pattern having the same height and diameter as shown in FIG. 11, or microlens patterns 113 having different heights and diameters as shown in FIG. 12 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.

Meanwhile, FIG. 13 is a perspective view of a composite reflective polarizing film according to an exemplary embodiment of the present invention, wherein the light diffusion layer 113 includes a prism pattern. To describe the prism pattern, the height (a) of the prism may be 10 to 50 탆. 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, .

In addition, the prism shape may be formed of the pattern 113 having the same height and pitch as shown in FIG. 13, or the prism patterns 115 having different heights and pitch as shown in FIG. 14 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 a linear prism shape, a vertical section is a triangle, and a vertex of the triangle opposing the lower surface forms an angle of 60 to 110 degrees.

The light-diffusing layer including the above-described fine pattern may be formed by curing including at least one polymer resin of a photocurable polymer resin or a thermosetting polymer resin. As a preferable example of the polymer resin, a polymer resin including a thermosetting or photocurable acrylic resin may be used. However, the kind of the polymer resin used may be changed depending on the shape of the fine pattern specifically included in the light diffusion layer. For example, the prism pattern may include an unsaturated fatty acid ester, an aromatic vinyl compound, an unsaturated fatty acid and a derivative thereof, and 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 light diffusion layer may be made of a material having a higher refractive index than the reflective polarizing film.

Further, according to a preferred embodiment of the present invention, the light-diffusing layer may include a bead coating layer. 15 to 17 are cross-sectional views of a light diffusion layer according to a preferred embodiment of the present invention. The bead coating layer may be a coating layer (see FIG. 15) in which the beads 108 are included in the resin layer 107, (See Fig. 16), a bead is attached to the upper surface of the resin layer (see Fig. 17) and / or a bead is directly attached to the upper surface of the reflective polarizing film without the resin layer Lt; / RTI > The diameter of the beads may be 0.1 to 100 탆, and when the beads satisfying such diameters are included, excellent optical properties may be realized. The density of the beads in the bead coating layer and the spacing between the beads can be designed differently according to the desired optical properties, and are not particularly limited in the present invention. However, if the distance between the beads is too small, the light transmission characteristics may be disadvantageous as the number of beads included per unit area increases. It is preferable that the distance between the beads is about 1 탆 or more.

The beads may include at least one of organic beads and inorganic beads. Examples of the organic beads include acrylic, styrene, melamine formaldehyde, propylene, ethylene, silicone, urethane, methyl (meth) acrylate, polycarbonate A homopolymer or a copolymer obtained by using a monomer can be exemplified. Examples of the inorganic beads include silica, zirconia, calcium carbonate, barium sulfate, and titanium oxide.

The resin constituting the resin layer is not particularly limited in the present invention but may be a UV curable material. Examples of the (meth) acrylate or polyfunctional (meth) acrylate monomer include 2-hydroxyethyl (meth) (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, butoxyethyl (meth) acrylate, ethyldiethylene glycol Rate, cycle

(Meth) acrylates such as hexyl (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentadiene (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (Meth) acrylate, isobornyl (meth) acrylate, N-vinylpyrrolidone, N-vinylcaprolactam, diacetone acrylamide, isobutoxymethyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, Acrylate, pentaerythritol tetra (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, Acrylate, dicyclopentane di (meth) acrylate, dicyclodecane dimethanol di (meth) acrylate, tripropylene glycol di (meth) acrylate, (Meth) acrylate and the like, and the above listed materials may be used singly or in combination.

In addition to the above-listed resins, additives may further be included, and as the additive, a material having high lubricity may be applied. For example, at least one of a silicone-based additive and a fluorine-based additive may be applied. Specifically, a reactive monomer having a silicon group or a reactive oligomer (for example, a silicone group-containing vinyl compound, a silicon group-containing (meth) acrylate compound, a (meth) acryloxy group-containing organosiloxane, A fluoroalkyl group-containing (meth) acrylate compound, a fluorine polyacrylate, etc.) having a fluorine group or a fluorine group, a reactive monomer or a reactive oligomer having a fluorine group A resin (e.g., polydimethylsiloxane, fluoropolymer, etc.), a silicone group or a surfactant having a fluorine group or an oil (for example, dimethylsilicone oil) may be used alone or in combination.

The content ratio of the UV curable material and the additive may range from 100: 0.001 by weight to 100: 10 by weight, and preferably from 100: 0.01 by weight to 100: 5 by weight.

Further, in addition to the UV curable material and the additive, a photoinitiator may be further included. Wherein the photoinitiator is selected from the group consisting of at least one free radical initiator selected from benzyl ketaldehyde, benzoin ethers, acetophenone derivatives, ketoxime ethers, benzophenone, benzo or thioxanthone compounds, onium salts, ferrocenium salts ferrocenium salts, and diazonium salts, or a mixture thereof.

The degree of physical properties of the composite reflective polarizing film may vary depending on the specific shape of the fine pattern described above. Specifically, when the fine pattern is a prism and / or a lenticular shape, While the increase in the haze value of the composite reflective polarizing film may be relatively lower than that in the case of the microlens shape. In addition, when the light diffusion layer does not include a fine pattern and has a bead coating layer, the haze value of the composite reflective polarizing film may be remarkably increased to realize a very good surface appearance quality, while the light transmittance is significantly lowered, The optical properties can be significantly reduced as compared with when the fine pattern is a microlens shape. Accordingly, the shape of the light-diffusing layer can be selected in accordance with the desired physical properties required. However, in order to simultaneously exhibit not only optical characteristics such as light condensation and luminance but also improvement in surface appearance quality by increasing the haze value of the composite reflective polarizing film, It may be more preferable to include a microlens-shaped fine pattern.

Meanwhile, a primer layer (not shown) may be selectively formed on the upper surface of the skin layer 220a of the reflective polarizer film 200. [ This can improve the adhesion, appearance, and electrooptical characteristics of the light diffusion layer 100 laminated. Examples of the material include, but are not limited to, acrylic, ester, and urethane. The adhesive layer can be formed thinner than the other layers, and the thickness of the adhesive layer can be adjusted to improve the light transmittance and reduce the reflectance. The thickness of the adhesive layer may be from 5 nm to 300 nm. If the thickness of the adhesive layer is less than 5 nm, the adhesion between the reflective polarizing film and the light diffusion layer may be insignificant. If the thickness of the adhesive layer exceeds 300 nm, unevenness or molecular aggregation may occur during the adhesive treatment.

Next, the reliability supporting layer 300 formed on the lower surface of the reflective polarizing film 200 will be described.

The reliability supporting layer 300 significantly improves the thermal reliability degradation caused by various processes for manufacturing a backlight unit and the like, including the dispersed polymer in the substrate, and further improves the haze, It is possible to minimize the decrease in luminance that may occur when a separate structure is included to improve the reliability.

The reliability of the composite reflective polarizing film in the description of the present invention means that the reflective polarizing film usually has a very high coefficient of thermal expansion due to the nature of the material thereof and is therefore suitable for manufacturing a module such as a composite reflective polarizing film and a backlight unit and / The surface of the reflective polarizing film is not affected by changes in appearance such as wrinkles and curvature such as curtains and / or deterioration of luminance due to high temperature in a humid environment, and wrinkles and bends appear on the outer appearance, Means that there is no panel unevenness due to a gap difference between the mountain portion and the valley portion and that there is no appearance damage such as being easily torn or damaged in the stretched direction when the reflective polarizing film is stretched on at least one axis .

를 만족시켜야 한다.The composite reflective polarizing film according to the present invention can provide reliability such as wrinkles and bending of the reflective polarizing film due to high temperature during manufacture and / or use, or easy tearing of the reflective polarizing film, and at the same time, (1) according to the present invention,

.

If the thickness of the reliability supporting layer exceeds twice the thickness of the reflective polarizing film, the objective reliability can be remarkably improved and the haze of the composite reflective polarizing film is greatly increased, thereby remarkably improving the appearance defects in which the foreign body is exposed There is a possibility that the optical characteristic such as luminance, which is one of the most important physical properties due to the reliability support layer, is remarkably increased and the optical characteristics are lowered when compared with the case where the reliability support layer is not included.

Therefore, the thickness of the reliability supporting layer should be not more than twice the thickness of the reflective polarizing film, and when the above conditions are satisfied, not only the desired optical characteristics are exhibited, but also problems such as thermal reliability and appearance defects can be effectively removed.

According to a preferred embodiment of the present invention, in order to remarkably exhibit all desired physical properties, the reliability supporting layer can satisfy the following relational expression 2 in relation to the reflective polarizing film.

[Relation 2]

If the thickness of the reliability supporting layer is less than 0.3 times the thickness of the reflective polarizing film, the reduction of the brightness can be minimized compared to when the reliability supporting layer is not included, but the reliability of the composite reflective polarizing film is remarkably poor. In addition, if the thickness of the reliability supporting layer exceeds 1.4 times the thickness of the reflective polarizing film, it is possible to exhibit the desired reliability, the improvement of the appearance quality through an excellent haze value, and the like, This can be.

Meanwhile, the composite reflective polarizing film according to the present invention can significantly improve the reliability as described above, and at the same time, in order to maintain optical properties such as brightness, according to a preferred embodiment of the present invention, , The thermal expansion coefficient can be in the range of 4 to 35 占 퐉 / m 占 폚, and more preferably in the temperature range of 70 to 80 占 폚, the thermal expansion coefficient can be in the range of 10 to 25 占 퐉 / m 占 폚. It is possible to prevent a change in appearance such as wrinkles and bending of the reflective polarizing film due to high temperature even in a high temperature and high humidity environment of a module manufacturing process such as a composite reflective polarizing film and a backlight unit and / As the optical property is prevented from deteriorating, excellent composite reflective polarizing film can have excellent reliability. If the above range is not satisfied, there may be a problem that physical properties such as desired optical characteristics, reliability and prevention of defective surface appearance may not be realized. Specifically, there is a problem that a thermal expansion coefficient of 35 μm / m ° C, the problem can be further exacerbated, and the composite reflective polarizing film may not be used in a backlight unit. When the thermal expansion coefficient is less than 4 μm / m · ° C., A reliability supporting layer having a characteristic can greatly deteriorate the optical characteristics, and a material having a thermal expansion coefficient of less than 4 占 퐉 / m 占 폚 while having the optical characteristic required for an optical film is rarely developed, Because it is expensive, it is very difficult to use it as a product reliability virtual trust base.

On the other hand, the material of the reliability supporting layer is not particularly limited when it satisfies the relational expression 1 according to the present invention, but it may preferably be a polyester resin in consideration of optical characteristics, heat resistance, chemical resistance, mechanical properties and economical efficiency. The polyester resin may be at least one selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytetramethylene terephthalate (PTT), polyhexylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, (Phenoxy) ethane-4,4'-dicarboxylate, polyethylene isophthalate / nephthalate copolymer, polybutylene terephthalate / isophthalate copolymer and polybutylene terephthalate / decane-dicarboxylate (PET), or modified polyethylene terephthalate, and more preferably polyethylene terephthalate (PET). [0033] The term " polyethylene terephthalate . As a non-limiting example of the modified polyethylene terephthalate, ethyleneglycol as a diol component and a sulfonated metal salt other than terephthalic acid as an acid component may be further included as a monomer. For example, dimethylsulfone isophthalate sodium salt, Can be. Further, it may further include an aromatic polycarboxylic acid other than terephthalic acid as a monomer, and for example, it may be any one or more of dimethyl terephthalate, isophthalate and dimethyl isophthalate. Further, as the diol component, a diol component other than ethylene glycol may be further included as a monomer. Examples of such a diol component include neopentyl glycol, diethylene glycol, neopentyl glycol, 1,3-propanediol, , 1,6-hexanediol, and the like. The specific composition and composition ratio of the modified polyethylene terephthalate are not particularly limited in the present invention.

Further, the reliability supporting layer may be a film stretched in at least one direction, more preferably a biaxially stretched film, and more preferably a biaxially stretched film in order to further improve physical properties such as improved strength, dimensional stability, It may be a film thermally fixed at 175 to 225 占 폚 after biaxial stretching, more preferably a polyethylene terephthalate film heat-fixed after biaxial stretching.

According to a preferred embodiment of the present invention, the thickness of the reliability supporting layer may be 10 to 600 mu m, and more preferably, the thickness may be reduced to minimize the decrease in luminance as the thickness of the supporting layer is increased, More preferably 60 to 300 占 퐉, and still more preferably 100 to 200 占 퐉. Thus, the properties of a composite reflective polarizing film such as a desired reliability can be realized at the same time while minimizing a luminance drop caused by including a reliability supporting layer. If the thickness of the reliable supporting layer is less than 10 mu m, the desired reliability can not be realized and it may not cover the appearance of foreign matter on the appearance of the reflective polarizing film. In particular, when the reflective polarizing film does not include the skin layer, The film may not be able to function properly. If the thickness of the reliable support layer exceeds 600 탆, high reliability can be realized, but there may be a problem that the brightness significantly decreases due to the thickness of the thick reliability support layer. However, the present invention is not limited to the above-described preferable thickness range of the reliability supporting layer and can be adjusted depending on the thickness of the reflective polarizing film to be used.

According to a preferred embodiment of the present invention, a first primer layer may be further provided between the reflective polarizing film and the reliability supporting layer for enhancing adhesion.

The first primer layer may be formed by curing a photopolymerizable resin or a thermosetting polymeric resin and including at least one polymer resin. As a specific type of such a polymer resin, any polymer resin capable of minimizing the luminance reduction due to the primer layer can be used without limitation, and examples of the material include silicone polymers, urethane polymers, SU-polymers having a silicone-urethane hybrid structure, acrylics, isocyanates, Based resin, a polyvinyl alcohol-based polymer, a gelatin-based polymer, a vinyl-based polymer, a latex-based polymer, a polyester-based polymer and a water-based polyester polymer. By way of non-limiting example, it may be a UV curable adhesive composition containing oligomers and monomers in a weight ratio of about 20-80%: 80-20%.

As the oligomer, one or more oligomers selected from urethane, epoxy acrylate, and polyester series may be applied. Examples of the monomer include DPHA (Dipentaerythritol Hexaacrylate), DPPA (Dipentaerythritol Pentaacrylate), TMPTA (trimethylolpropane triacrylate), TMPTMA (Trimethylol propane triacrylate), HDDA (Hexanedioldiacrylate), DPGDA 2-Hydroxyethyl acrylate (2-HEA), 2-Hydroxyethyl Methacrylate (2-HEMA), and 2-Hydroxyethyl acrylate (TPE) ≪ / RTI > may be applied. More specifically, as a non-limiting example of this, DPAH (5-30%), DPPA (5-30%), TMTPA (3-20), PEA (10-50%), IBOA %), 2-HEMA (1 to 10), 2-HEA (1 to 10%), and other monomers (1 to 30%).

The first primer layer may be formed thinner than the other layers, and the thickness of the first primer layer may be adjusted to improve the light transmittance and reduce the reflectance. The thickness of the first primer layer may be 1 占 퐉 to 10 占 퐉. If the thickness of the first primer layer is less than 1 mu m, adhesion between the reflective polarizer film and the reliability supporting layer may be insufficient. If the thickness of the first primer layer exceeds 10 mu m, Lt; / RTI >

As described above, the composite reflective polarizing film according to the first embodiment of the present invention may have a haze value of 65% or more, preferably 73% or more, and more preferably 85% or more, of the composite reflective polarizing film .

By satisfying the haze value, it is possible to prevent the appearance of various foreign substances, bubbles, etc., which may be contained in the film in the manufacturing process, thereby improving the appearance quality. If the above range is not satisfied, there is a problem that the quality of the outer appearance is deteriorated and a separate device or another separate structure must be added in order to prevent visible foreign substances. And there is a problem that the manufacturing time and manufacturing cost are increased due to the added structure.

According to a second embodiment of the present invention, there is provided a composite reflective polarizing film comprising a reflective polarizing film in which a polymer is dispersed in a substrate, the composite reflective polarizing film comprising: a reliable supporting layer formed on an upper surface of the reflective polarizing film; And a light diffusion layer formed on the upper surface of the reliability supporting layer, wherein the thickness of the reflective polarizing film and the thickness of the reliability supporting layer satisfy the following relational expression (1).

[Relation 1]

Prior to the description of the second embodiment of the present invention, the second embodiment will be described focusing on differences from the first embodiment described above.

The composite reflective polarizing film according to the second embodiment of the present invention is different from the first embodiment in the stacking order of the reflective polarizing film, the light diffusing layer, and the reliability supporting layer. Specifically, Fig. Sectional view of the reflective polarized light, showing a reliable supporting layer 300 'formed on the reflective polarizing film 200' and a light-diffusing layer 100 'formed on the reliability supporting layer 300'.

The composite reflective polarizing film according to the second embodiment of the present invention may have a somewhat reduced luminance due to the reliable supporting layer as compared with the composite reflective polarizing film according to the first embodiment, It is possible to prevent the expression and defects of the surface appearance.

According to a third aspect of the present invention, there is provided a composite reflective polarizing film comprising a reflective polarizing film in which a polymer is dispersed in a substrate, the composite reflective polarizing film comprising: a light-diffusing layer formed on an upper surface of a reflective polarizing film; And a reliable supporting layer formed on an upper surface of the light diffusing layer, the composite reflective polarizing film satisfying the following conditions (1) and (2).

(1) Reliability The support layer has a thermal expansion coefficient of 4 to 35 μm / m · ° C. at a temperature range of 70 to 80 ° C., and (2) the haze value of the composite reflective polarizing film is 65% or more.

Prior to the description of the third embodiment of the present invention, the third embodiment will be described focusing on differences from the first embodiment described above.

The composite reflective polarizing film according to the third embodiment of the present invention is different from the first embodiment in the stacking order of the reflective polarizing film, the light diffusing layer, and the reliability supporting layer, and the composite reflective polarizing film according to the third embodiment of the present invention Compared with the composite reflective polarizing film according to one embodiment, the reliability can be reduced due to the support layer, but there is an advantage that excellent reliability expression and a defect in surface appearance similar to that of the first embodiment can be prevented. However, in the case of the composite reflection film according to the third embodiment, the light diffusion layer may include a fine pattern, more preferably a prism pattern, in order to improve the decreasing optical characteristics.

Next, a method for producing a composite reflective polarizing film according to a preferred embodiment of the present invention will be described. However, the manufacturing method described below is a preferred embodiment, and the present invention is not limited thereto.

A composite reflective polarizing film according to a preferred embodiment of the present invention includes a reflective polarizing film in which a polymer is dispersed in a substrate, the method comprising the steps of: (1) forming a light diffusing layer on the upper surface of the reflective polarizing film; ; And (2) forming a reliable support layer on the lower surface of the reflective polarizing film. However, the steps (1) and (2) may be performed in any order.

First, in step (1), a step of forming a light diffusion layer on the upper surface of the reflective polarizing film will be described.

According to a preferred embodiment of the present invention, the reflective polarizing film includes: (a) a base material and a plurality of dispersing materials contained in the base material, the plurality of dispersing materials for transmitting the 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 at least one axial direction from the base material, and the ratio of the short axis length to the major axis length Of the first group among the groups is 0.2 to 2.0 占 퐉 ² , and the second group of the second group of the second group contains 0.2 to 2.0 占 퐉 ² , and the second Group has a dispersoid cross-sectional area of more than 2.0 mu m ² to 5.0 mu m < ² > or less, a third group of dispersoids has a cross-sectional area of more than 5.0 mu m ² to 10.0 mu m ² or less, ; . ≪ / RTI >

According to a preferred embodiment of the present invention, there is provided a method for manufacturing a polarizing plate, comprising the steps of: (a) forming an integrated skin layer on at least one surface of the core layer using the reflective polarizing film produced through the step (a) ; ≪ / RTI > a reflective polarizing film can be produced.

The description of the core layer and the skin layer is omitted because they are the same as those described above, and the manufacturing process will be mainly described below.

Hereinafter, the process of performing both the above (a) and (b) will be described, but the present invention is not limited thereto. In addition, the steps (a) and (b) may be performed through an integral process which will be described later, not intermittently.

Specifically, first, the base component, the dispersion component and the skin layer component are supplied to the extruding portion. The base component can be used without limitation as long as it is used in a reflective polarizing film in which a conventional dispersion is dispersed. Preferably, the base component is 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 It is possible to use amide (PA), polyacetal (POM), phenol, epoxy (EP), urea (UF), melanin (MF), unsaturated polyester (UP) It can be a PEN.

The dispersion component can be used without limitation as long as it is usually used in a reflective polarizing film in which a dispersion is dispersed. Preferably, the component is polyethylene naphthalate (PEN), co-polyethylene naphthalate (co-PEN), polyethylene terephthalate (PET) (PS), polymethylmethacrylate (PMMA), polybutylene terephthalate (PBT), polypropylene (PP), polypropylene (PP) (PE), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile blend (SAN), ethylene vinyl acetate (EVA) (PA), polyacetal (POM), phenol, epoxy (EP), urea (UF), melanin (MF), unsaturated polyester (UP), silicone (SI) and cycloolefin polymers, Can be used and more desirable It may be a 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 may be a conventionally used component, but is not particularly limited as long as it is used in a reflective polarizing film, and preferably polyethylene naphthalate (PEN), co-polyethylene naphthalate (co-PEN) (PS), polymethylmethacrylate (PMMA), polybutylene terephthalate (PBT), polybutylene terephthalate (PBT), and polyethylene terephthalate (PET), polycarbonate 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) Polymers may be used singly or in combination. Monomers such as dimethyl-2,6-naphthalene dicarboxylate, dimethyl terephthalate and ethylene glycol, cyclohexanedimethanol (CHDM), etc. may be 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 19 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 20 is a side view of Figure 19. 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. 19, since the substrate on which the skin layer conveyed through the channel 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 the steps of: cooling and smoothing a reflection polarized film transferred from a flow control unit; And a step of thermally fixing the stretched reflective polarizing film.

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

Thereafter, a process of stretching the reflective polarizing film through the smoothing step is performed.

The stretching may be performed through a conventional stretching process of a reflective polarizing film, thereby causing a refractive index difference between a base component and a dispersing component to cause light modulation at the interface, and the spreading induced first component Dispersion component) is further reduced in aspect ratio through 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 polarizing film can be manufactured through a step of heat-setting the stretched reflective polarizing film. 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 step of forming a light diffusion layer on the upper surface of the produced reflective polarizing film is performed.

At this time, an adhesive layer may be further formed on the upper surface of the reflective polarizing film to facilitate the formation of the light diffusion layer. As a result, the adhesive strength, appearance, and electrooptic characteristics of the light diffusion layer can be improved. Examples of the material include, but are not limited to, acrylic, ester, and urethane. The adhesive layer can be formed thinner than other layers, and the thickness of the primer layer can be adjusted to improve the light transmittance and reduce the reflectance. The thickness of the adhesive layer may be from 5 nm to 300 nm. If the thickness of the adhesive layer is less than 5 nm, the adhesion between the reflective polarizing film and the light diffusion layer may be insignificant. If the thickness of the adhesive layer exceeds 300 nm, unevenness or molecular aggregation may occur during the adhesive layer treatment.

 According to a preferred embodiment of the present invention, the light diffusion layer may form a fine pattern on at least one surface or form a bead coating layer, thereby maximizing the light collecting effect and preventing irregular reflection on the surface, thereby remarkably improving the brightness. The fine pattern may be at least one pattern selected from the group consisting of a prism, a lenticular, a micro lens, a triangular pyramid, and a pyramid pattern, and each of these patterns 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 bead coating layer may be a coating layer in which the beads are contained in the resin layer, a part of the beads is embedded in the upper part of the resin layer, beads are attached to the upper surface of the resin layer and / Beads may be directly formed.

The material of the light diffusion layer is preferably a polymer resin including a thermosetting or photo-curable acrylic resin. 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 light diffusion layer may be made of a material having a higher refractive index than the reflective polarizing film.

A specific method of forming the light diffusion layer including such a fine pattern on the upper surface of the reflective polarizing film is not particularly limited in the present invention, but it is preferable that the inverse pattern of the fine pattern is a master roll, Can be formed on the reflective polarizing film through the molded pattern molding film.

According to a preferred embodiment of the present invention, in a method using a master roll in which a reverse pattern of the fine pattern is formed, 1-i) prisms, a lenticular, a microlens, a triangular pyramid, a bead and a pyramid pattern Applying a reflective polarizing film to a master roll formed on an outer surface in a reversed phase pattern with respect to at least one selected fine pattern and applying the molten polymer resin to the pattern surface of the master roll or the reflective polarizing film; And 1-ii) curing the polymer resin by applying at least one of light and heat while the polymer resin is press-formed on the pattern surface of the master roll, and separating the polymer resin.

The method may further include the step of secondarily curing the polymer resin by irradiating UV or heat again after the step 1-ii).

21 is a schematic view of a process of forming a fine pattern according to a preferred embodiment of the present invention, and FIG. 22 is a cross-sectional view showing a detailed structure of the forming unit of FIG. In FIG. 22, the reflection type polarizing film 770 is released from the star trolley 755, passes through the guide roll 754, and passes through the infrared lamp 751. In this process, the reflection type polarizing film 770 is surface-modified by the infrared rays of the infrared lamp to improve the adhesion with the light diffusion layer 771. The reflective polarizing film 770 leaving the star trolley 755 is guided to the master roll 705 via the pattern guide roll 764 so that the patterned surface of the master roll 705 from the injection portion 742, The polymer as the material of the reflective polarizing film 770 is applied and combined with the reflective polarizing film 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. At this time, the temperature around the curing unit 752 is 20 to 30 ° C, and the temperature of the heat generated when the resin is cured is 40 to 80 ° C, and the glass transition temperature of the resin (Tg: Temperature that represents a changed characteristic, such as soft rubber, before undergoing a phase change). The light diffusing layer 771, which has completely transferred the pattern of the master roll surface in the glass transition state, passes through the pattern guide roll 764 again and is reflected by the reflective polarizing film 770 and the light diffusing layer 771, (772), passed through a guide roll (754) and wound on a finish roll (756).

As shown in FIG. 20, the end face of the reflective polarizing film 772 formed with the turn formed by irradiating UV light twice is a face contrary to the end face of the master roll 705. For example, If the surface is an engraved surface, the reflective polarizing film 772 on which the turn is formed becomes an embossed surface of the embossed surface.

Next, in the case of a method using a mold film for pattern formation in which an inverse pattern of a fine pattern is formed, a film having transparency, flexibility, predetermined tensile strength and durability can be used as the material of the mold film for pattern formation, It is preferable to use a film.

In this case, according to a preferred embodiment of the present invention, the step (1) may include: 1-1) a step of repeating the steps of: 1-1) forming at least one fine pattern selected from the group consisting of reflective polarizing film and prism, lenticular, microlens, triangular pyramid, bead, Transferring a mold-forming mold film formed on one surface of a pattern which is in a reverse phase to that of the pattern-forming mold film; 1-2) bringing the upper surface of the reflective polarizing film and the pattern-forming mold film into contact with one surface of the patterned surface; 1-3) filling a void space between two films formed by the pattern by injecting a fluid material between the adhered reflective polarizing film and the mold film for pattern formation; 1-4) curing the filled material and separating the mold film for pattern formation.

Preferably, the step of filling the material between the two reflective films formed by the pattern by uniformly applying pressure between the reflective polarizing film and the mold film for pattern formation between steps 1-3) and 1-4) .

Preferably, the step 1-4) may include the step of applying at least one of heat and light to the material filled in the void space between the two films formed by the pattern.

23 is a schematic view of a process of forming a fine pattern according to another preferred embodiment of the present invention.

First, the reflective polarizing film 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 polarizing film 810 is attracted by the guide roll 830c to be engaged with the molding mold 842. [ Here, the guide roll 830c performs a gap adjusting function to adjust the thickness of the pattern of the coating liquid applied to the reflective polarizing film 810, that is, the angle of the light diffusing layer of which the light diffusion layer is made of resin. More specifically, when the guide roll 830c is in close contact with the master roll 844, the pattern of the light diffusion layer can be made thinner. On the contrary, when the guide roll 830c is further separated from the master roll, It can be formed thick. The pattern thickness of the light diffusion layer can be adjusted by the viscosity of the coating liquid, the patterning speed, and the tension of the reflective polarizing film in addition to the interval between the guide roll 830c and the master roll 844.

The coating liquid is injected into the reflective polarizing film 810 at a position where the guide roll 830c and the master roll 844 are engaged with each other by the coating liquid injecting means 860 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 and / or UV emitted from the curing means 870. The patterned coating liquid is cured and applied to the reflective polarizing film. The cured and applied reflective polarizing film is separated from the molding die 842 while being guided by the guide roll 830d. The patterned reflective polarizing film 812 is transferred by the guide roll 830e, 2 roll 850. As shown in Fig. Here, the guide roll 830d performs a peeling function to separate the reflective polarizing film 812 on which the coating solution is applied, that is, the light diffusion layer, from the molding die 842. [

The reflective polarizing film 810 and the reflective polarizing film 812 having the light-diffusing layer formed on one surface thereof are connected to each other and are classified for ease of explanation. That is, the reflective polarizing film 810 refers to a state before the light diffusion layer is formed, and the reflective polarizing film 812 having the light diffusion layer formed thereon passes through the pattern molding portion 840, It means that it is applied and finished. In Fig. 23, only a part of the pattern layer formed on the reflective polarizing film 812 on which the light-diffusing layer is formed is shown. In reality, the light-diffusing layer is also formed on the reflective polarizing film wound on the second roll 850.

24 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 polarizing film 910, so that the reflective polarizing film 912 on which the light-diffusing 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 the reflective polarizing film 910 is wound and a second roll 950 on which the reflective polarizing film 912 on which the light- Guide rolls 930a to 930f provided on both sides for conveying the reflective polarizing film having the reflective polarizing film and the light diffusing layer are provided between the first roll 920 and the second roll 950. Between the guide roll 930c and the guide roll 930d, a master roll 946 of the pattern molding unit 940 is tightly adhered to apply the coating liquid to the reflective polarizing film 910. It goes without saying that the number and positions of the guide rolls 930a to 930f may be changed depending on 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 reflective polarizing film 910, pattern guide rolls 947a to 947d for conveying the forming mold and a fourth roll 948 for winding the conveyed forming 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.

The shaping mold 942 is conveyed by the master roll 946 and the guide rolls 947a to 947d while being wound on the third roll 944 in contrast to the embodiment of Figure 23 and is fed to the reflective polarizing film 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 the reflective polarizing film 910, and a pattern defect due to the seam or a discontinuity in the pattern is caused in the reflective polarizing film 912 in which the light- The pattern is uniformly formed over the entire region without the formation of the pattern. In FIG. 24, only a part of the pattern embodying the pattern is shown in the forming mold, but in actual practice, the pattern is implemented throughout the forming mold.

A coating liquid injecting means 960 for injecting a coating liquid is provided at a point where the reflective polarizing film 910 is drawn into the pattern molding portion 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 means 970 for curing the coating liquid by irradiating heat or UV is provided at a point where the reflective polarizing film and the forming mold 942 are closely contacted with each other.

On the other hand, the method of forming the bead coating layer on the reflective polarizing film is not particularly limited, but the bead coating layer forming composition may be coated on the reflective polarizing film by a conventional method. Preferably, the coating method may be formed by any one of comma coating, reverse coating, gravure coating, braid coating, silk screen coating and slot die head coating. At this time, the bead coating layer may be formed so that the bead is contained in the resin layer by adjusting the bead diameter included in the composition and the thickness according to the amount of the applied composition, or the bead coating layer may be formed with only a part of the bead embedded therein. The coated composition may be cured through light and / or heat depending on the kind of resin contained, depending on the usual conditions, and the light may preferably be UV.

Next, in step (2) according to a preferred embodiment of the present invention, a step of forming a reliable supporting layer on the lower surface of the reflective polarizing film is performed.

According to a preferred embodiment of the present invention, the step (2) comprises the steps of: 2-1) forming a first primer layer on the upper surface of the reliability supporting layer to enhance adhesion between the reflective polarizing film and the reliability supporting layer; And 2-2) bonding the first primer layer and the lower surface of the reflective polarizing film so as to be in contact with each other.

According to a preferred embodiment of the present invention, in the step 2-1), the reflective polarizing film may be stretched in at least one axial direction, and the reliability supporting layer may be a uniaxially stretched polyethylene terephthalate film.

The first primer layer may form at least one polymer resin of a photocurable polymer resin or a thermosetting polymer resin on the lower surface of the reflective polarizing film or on the upper surface of the reliable support layer, . As a specific type of such a polymer resin, any polymer resin capable of minimizing the luminance reduction due to the primer layer can be used without limitation, and examples of the material include silicone polymers, urethane polymers, SU-polymers having a silicone-urethane hybrid structure, acrylics, isocyanates, Based resin, a polyvinyl alcohol-based polymer, a gelatin-based polymer, a vinyl-based polymer, a latex-based polymer, a polyester-based polymer and a water-based polyester polymer. Such a polymer resin can be formed by coating the upper surface of the reliability supporting layer by a conventional method.

Examples of the material and thickness of the first primer layer are the same as those described above.

Next, in step 2-2), a step of joining the lower surface of the reflective polarizing film to the formed first primer layer is performed. At this time, the first primer layer may be cured after being laminated to the reflective polarizing film in a semi-cured state and cured or coated in the state of being laminated to the reflective polarizing film. The curing can be determined according to the kind of the polymer resin used as the first primer layer, and can be preferably cured through heat and / or light, and a specific method of performing the curing is a known method And is not particularly limited in the present invention.

Meanwhile, the steps (1) and (2) according to the method for producing a composite reflective polarizing film according to a preferred embodiment of the present invention can be performed independently of the order, .

FIG. 25 is a cross-sectional view of a laminated reflective polarizing film and a reliability supporting layer according to a preferred embodiment of the present invention, in which a first primer layer 400 is formed on the lower surface of the reflective polarizing film 200 The reliability supporting layer 300 is laminated so that the first primer layer 400 is in contact with the lower surface of the reflective polarizing film 200 and then the laminated reflective polarizing film / first primer layer / Troll 755 or the first roll 820 of FIG. 23 to form a light diffusion layer on the upper surface of the reflective polarizing film.

The composite reflective polarizing film described above may be employed in a light source assembly or a liquid crystal display including the same, and may be used to enhance light efficiency. The light source assembly may be classified as a direct light source assembly in which the lamp is located at the bottom, an edge light source assembly in which the lamp is located at the side, and the like. The composite reflective polarizing film according to embodiments of the present invention may be applied to any kind of light source assembly . It is also applicable to a back light assembly disposed below the liquid crystal panel or a front light assembly disposed above the liquid crystal panel. Hereinafter, as an example of various applications, a composite reflective polarizing film according to an exemplary embodiment as shown in FIG. 5 is applied to a liquid crystal display including an edge light source assembly.

26 is a cross-sectional view of a liquid crystal display device according to an exemplary embodiment of the present invention. The liquid crystal display device 2700 includes a backlight unit 2400 and a liquid crystal panel assembly 2500.

The backlight unit 2400 includes a composite reflective polarizing film 2111 for modulating the optical characteristics of the emitted light. The other components included in the backlight unit and the positional relationship between the other components and the composite reflective polarizing film 2111 Is not particularly limited in the present invention.

26, a light source 2410, a light guide plate 2415 for guiding light emitted from the light source 2410, a reflection film 2320 disposed below the light guide plate 2415, And a composite reflective polarizing film 2111 disposed on the upper side of the light guide plate 2415. [

At this time, the light sources 2410 are disposed on both sides of the light guide plate 2415. The light source 2410 may be a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), or an external electro fluorescent lamp (EEFL). In another embodiment, the light source 2410 may be disposed only on one side of the light guide plate 2415. [

The light guide plate 2415 moves the light emitted from the light source 2410 through total internal reflection, and emits the light upward through a scattering pattern or the like formed on the lower surface of the light guide plate 2415. A reflective film 2420 is disposed under the light guide plate 2415 to reflect the light emitted downward from the light guide plate 2415 upward.

A composite reflective polarizing film 2111 is disposed on the upper side of the light guide plate 2415. Since the composite reflective polarizing film 2111 has been described in detail above, a duplicate description will be omitted. Other optical sheets may be further disposed above or below the composite reflective polarizing film 2111. [ For example, a liquid crystal film that partially reflects incident circularly polarized light, a retardation film that converts circularly polarized light into linearly polarized light, and / or a protective film may be further provided.

The light source 2410, the light guide plate 2415, the reflection film 2420 and the composite reflection polarizing film 2111 can be received by the bottom chassis 2440.

The liquid crystal panel assembly 2500 includes a first display panel 2511, a second display panel 2512 and a liquid crystal layer (not shown) interposed therebetween. The liquid crystal panel assembly 2500 includes a first display panel 2511 and a second display panel 2512 And a polarizing plate (not shown) attached to the surface of the polarizing plate.

The liquid crystal display device 2700 may further include a top chassis 2600 covering the edges of the liquid crystal panel assembly 2500 and surrounding the sides of the liquid crystal panel assembly 2500 and the backlight unit 2400.

Specifically, FIG. 27 shows an example of a liquid crystal display device adopting the composite reflective polarizing film of the present invention, in which a reflection plate 3280 is inserted on a frame 3270, and a cold cathode fluorescent lamp (3290). An optical film 3320 is disposed on the upper surface of the cold cathode fluorescent lamp 3290 and the optical film 3320 is disposed in the order of the diffusion plate 3321, the composite reflective polarizing film 3322, and the absorbing polarizing film 3323 However, the structure of the optical film and the stacking order between the respective structures may vary depending on the purpose, and some of the constituent elements may be omitted or a plurality thereof may be provided. Further, a phase difference film (not shown) or the like can also be inserted at an appropriate position in the liquid crystal display device. On the other hand, the liquid crystal display panel 3310 may be positioned on the upper surface of the optical film 3320 by being inserted into the mold frame 3300.

The light emitted from the cold cathode fluorescent lamp 3290 reaches the diffuser plate 3321 of the optical film 3320. The light transmitted through the diffuser plate 3321 passes through the composite reflective polarizing film 3322 to cause the light to proceed in the direction perpendicular to the optical film 3320 while the light is modulated. Specifically, the P wave transmits the reflection polarizing film without loss, but in the case of the S wave, light modulation (reflection, scattering, refraction, etc.) occurs and is reflected by the reflection plate 3280, which is the back surface of the cold cathode fluorescent lamp 3290, The properties of the light are randomly changed into a P wave or an S wave, and then pass through the composite reflective polarizing film 3322 again. And then reaches the liquid crystal display panel 3310 after passing through the absorption polarizing film 3323. [ Meanwhile, the cold cathode fluorescent lamp 3290 may be replaced with an LED.

The embodiments described above can effectively exhibit a plurality of light modulation characteristics and can improve brightness by using the composite reflective polarizing film according to one embodiment of the present invention, It is possible to prevent appearance defects appearing on the appearance and to secure the reliability of the composite reflective polarizing film even in a high temperature and high humidity environment where a liquid crystal display device is used. Further, since the light-diffusing layer and the light-collecting layer having functions are integrated with the reflective polarizing film, the thickness of the light source assembly can be reduced, and the assembling process can be simplified. Accordingly, the image quality of a liquid crystal display including such a light source assembly can be improved.

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

The present invention will now be described more specifically with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

≪ 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. 18 and 19, which corrected the flow rate and pressure gradient. Specifically, the width of the die inlet was 200 mm, the thickness was 10 mm, the width of the die outlet was 1,260 mm, the thickness was 2.5 mm, and the flow rate was 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 ° C for 2 minutes to produce a randomly distributed reflective polarizing film having a thickness of 120 μm (thickness including a skin layer of 300 μm). (Nx: 1.88, ny: 1.58, nz: 1.58) of the polyethelene naphthalate (PEN) component of the produced reflective polarizing film, and the content of terephthalate, ethyl glycol and cyclohexanedimethanol 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. At this time, the thickness of the core layer was 120 占 퐉, and the thickness of the skin layer was 40 占 퐉, respectively, and the total thickness of the reflective polarizing film was 200 占 퐉.

Thereafter, the produced reflective polarizing film was subjected to a process as shown in FIG. 21 to form a light-diffusing layer including a urethane acrylic micro lens pattern having a refractive index of 1.59 on the upper surface of the reflective polarizing film. At this time, the height of the lens in the microlens pattern was 20 mu m.

On the other hand, DPHA (Dipentaerythritol Hexaacrylate) was applied on one surface of a polyethylene terephthalate (PET) film (EXCEL, Toray Advanced Material) having a thickness of 188 탆 and biaxially stretched four times in the longitudinal direction and in the transverse direction, 15 weight% of dipentaerythritol pentaacylate (DPPA), 12 weight% of trimethylolpropane triacylate (TMPTA), 25 weight% of phenoxyethyl acrylate (PEA), 20 weight% of isobornyl methacrylate (IBOA) A reliable support layer having a thickness of 5 탆 was formed on the back surface of the reflective polarizing film on which the light diffusion layer was formed and an adhesive containing 2 wt% of 2-hydroxyethyl acrylate (2-HEA) and 2 wt% of 2-hydroxyethyl acrylate (2-HEA) The PET film was laminated such that the surfaces with the adhesive were in contact with each other to produce a composite reflective polarizing film as shown in Table 1.

≪ Examples 2 to 14 >

A composite reflective polarizing film was produced in the same manner as in Example 1 except for the conditions of Table 1 or 2 below.

The height of the lenticular lens of Example 8 was 20 mu m and the pitch was 40 mu m, and the height of the prism pattern of Example 9 was 20 mu m and the pitch was 40 mu m.

≪ Example 15 >

A polymer reflective polarizing film was prepared in the same manner as in Example 1 except that a randomly dispersed reflective polarizing film dash was produced by the following method to prepare a composite reflective polarizing film as shown in Table 2. [

The plate-like polymer dispersed reflective polarizing film was processed as shown in Fig. 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, a refractive index of 1.64 and a refractive index obtained by polymerizing 90 wt% of polycarbonate and 10 wt% of polycyclohexylene dimethylene terephthalate (PCTG) as a skin layer component 1.58 were injected into the first extruding part 220, the second extruding part 221 and the third extruding part 222, respectively. The extrusion temperature of the first component and the second component was adjusted to 295 캜 and the Cap flow meter was calibrated through IV adjustment to adjust the polymer flow, and the skin layer was subjected to the extrusion process at a temperature of 280 캜. The first component was transferred to the first pressurizing means (230, Kawasaki gear pump) and the second component was also transferred to the second pressurizing means (231, Kawasaki gear pump). The discharge amounts of the first pressurizing means are respectively 8.9 kg / h and 8.9 kg / h, respectively. And a sea-island type mixed flow was produced by using a sea-island type extrusion-opening as shown in Fig. Specifically, the number of layers of the fourth component distribution plate (T4) was 400, the diameter of the hole of the component supply channel was 0.17 mm, and the number of the component supply channels was 25,000. The diameter of the discharge port of the sixth corrugated distribution plate was 15 mm x 15 mm. In the three-layered feed block, skin layer components flowed from the third extruded portion through the flow path to form a skin layer on the upper and lower surfaces of the sea-island composite stream (core layer polymer). Spreading was induced in the coat hanger dies of Figs. 19 and 20 in which the core layer polymer having the skin layer formed so as to have an aspect ratio of the sea-island complex flow of 1/30295 was corrected for flow velocity and pressure gradient. Specifically, the width of the die inlet is 200 mm, the thickness is 20 mm, the width of the die outlet is 960 mm, the thickness is 2.4 mm, The flow rate was 1 m / min. Then, a smoothing process was performed on the cooling and casting rolls and stretched 6 times in the MD direction. As a result, the major axis length of the first component was not changed but the minor axis length was decreased. Thereafter, thermal fixation was carried out through an IR heater at 180 DEG C for 2 minutes to produce a reflective polarizing film in which the polymer was dispersed as shown in Fig. The refractive index of the first component of the produced reflective polarizing film was (nx: 1.88, ny: 1.64, nz: 1.64) and the refractive index of the second component was 1.64. The aspect ratio of the polymer was approximately 1/180000, the number of layers was 400, the minor axis length (thickness direction) was 84 nm, the major axis length was 15.5 mm, and the average optical thickness was 138 nm. The prepared reflective polarizing film core layer had a thickness of 59 탆, and the skin layer had a total thickness of 141 탆.

≪ Example 16 >

A composite reflective polarizing film as shown in Table 2 below was prepared in the same manner as in Example 1 except for the conditions shown in Table 2 below.

At this time, the PET film used as the reliability supporting layer in Example 16 was a PET film (TSI) having a coefficient of thermal expansion of 36.25 占 퐉 / m 占 폚 at a temperature range of 70 to 80 占 폚.

≪ Comparative Examples 1 to 4 >

A composite reflective polarizing film was produced in the same manner as in Example 1 except for the conditions shown in Table 3 below.

<Experimental Example>

The following properties were evaluated for the reflection type polarizers prepared by the above-mentioned Examples and Comparative Examples, and the results are shown in Tables 1 to 3.

1. Relative luminance

The brightness of the composite reflective polarizing film was measured in the following manner. The panel was assembled on a 32 "direct-type backlight unit equipped with a diffusion plate and a composite reflective polarizing film, and the brightness was measured at nine points using a BM-7 measuring apparatus 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 composite reflective polarizing film of Example 1 is taken as 100 (standard).

2. Visible lines

The panel was assembled on a 32 "direct underlying type backlight unit equipped with a composite reflective polarizing film, a diffusion plate, a diffusion sheet, a prism sheet, and a brightness enhancement film, and the appearance of the bright line was evaluated. Specifically, The number of bright lines was evaluated as 0 excellent, 1 good, 2 to 3 normal, and 4 to 5 or more poor.

3. Polarization degree

The degree of polarization was measured using a RETS-100 analyzer from OTSKA.

4. Haze measurement

The haze was measured using a haze and permeability meter (manufactured by Nippon Denshoku Kogyo Co.).

5. Whether a foreign object

The appearance of the composite reflective polarizing film was visually observed to evaluate whether the foreign substance in the film was visible to the naked eye. As a result, the result was expressed as 0 when no foreign matter was observed and 1 to 5 according to the degree of foreign matter being visually observed.

6. Reliability assessment

The composite reflective polarizing film was allowed to stand at 60 DEG C and 75% relative humidity, and then 96 hours was first observed. After that, the degree of change was observed up to 1000 hours to evaluate whether the appearance of the composite reflective polarizing film was changed or wrinkles were formed . The evaluation results were 0 for no change in appearance, and 1 to 5 for the greater degree of change.

Specifically, as can be seen from Tables 1 to 3,

Examples 1 to 5 were superior to those of Examples 6 and 7 in luminance, polarization and bright line appearance. According to a preferred embodiment of the present invention, Example 1 belonging to the 1/3 group range 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.

It can also be seen from Examples 1, 8 and 9 that when the shape of the fine pattern included in the light-diffusing layer is a microlens, it is remarkably excellent in the manifestation of higher haze properties when it is a prism or a lenticular shape, It can be confirmed that Example 1 is superior in physical properties such as appearance of foreign bodies.

Also, among the composite reflective polarizing films satisfying the relational expression 1 according to the present invention, the composite reflective polarizing film according to Examples 1 and 11 to 13, which satisfy the relational expression 2 according to the present invention, It can be confirmed that it is satisfied with various physical properties such as reliability and optical properties at the same time as Examples 10 and 14.

In addition, it can be confirmed that Example 15 in which the reflection type polarizing film of the plate-type polymer dispersion type is changed is poor in optical characteristics such as luminance than Example 1. [

In addition, even in the case of including the reliability supporting layer, it is confirmed that the reliability of Example 16 in which the coefficient of linear expansion exceeds 35 占 퐉 / m 占 폚 was significantly lowered.

Also, in Example 1 including the reliability supporting layer, it can be confirmed that excellent physical properties are realized in the reliability evaluation, but it can be confirmed that the reliability of Comparative Example 1 in which only the remaining components are the same and the reliability supporting layer is omitted is remarkably decreased.

In addition, in Comparative Examples 2 and 3 in which the light-diffusing layer was not included, the haze value was remarkably lowered compared with Example 1 containing the light-diffusing layer, and it was found to be poor in bright line appearance and foreign matter was remarkably displayed.

Further, in Comparative Example 4 in which Relative Formula 1 according to the present invention was unsatisfactory, it was confirmed that the optical properties such as luminance were remarkably lowered as compared with Example 1.

Claims (20)

A composite reflective polarizing film comprising a reflective polarizing film in which a polymer is dispersed in a substrate,
A light diffusion layer formed on an upper surface of the reflective polarizing film; And
And a reliable supporting layer formed on a lower surface of the reflective polarizing film,
Wherein the thickness of the reflective polarizing film and the thickness of the reliability supporting layer satisfy the following relational expression (1).
[Relation 1]

The method according to claim 1,
Wherein the light diffusing layer comprises at least one polymer resin selected from the group consisting of a photocurable polymer resin and a thermosetting polymer resin. The method according to claim 1,
Wherein the light diffusion layer comprises at least one fine pattern selected from the group consisting of a prism, a lenticular, a micro lens, a triangular pyramid, and a pyramid pattern. The method of claim 3,
Characterized in that the fine pattern comprises a microlens. The method according to claim 1,
Wherein the light diffusing layer comprises a bead coating layer. The method according to claim 1,
Wherein the reliability supporting layer is a polyester film stretched in at least one direction. The method according to claim 1,
Wherein the thickness of the reflective polarizing film and the thickness of the reliability supporting layer satisfy the following relational expression (2).
[Relation 2]

The method according to claim 1,
And a first primer layer for enhancing adhesion between the reflective polarizing film and the reliable supporting layer. The method according to claim 1,
Wherein the reliability supporting layer satisfies a thermal expansion coefficient of 4 to 35 占 퐉 / m 占 폚 at a temperature range of 70 to 80 占 폚. The liquid crystal display according to claim 1, wherein the reflective polarizing film
And a plurality of dispersing members contained in the substrate to transmit the first polarized light emitted from the outside and reflect the second polarized light,
The plurality of dispersing bodies are different in refractive index from the substrate 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 with respect to a vertical cross section in the longitudinal direction,
The dispersions having the aspect ratio of 1/2 or less are included in at least three groups according to the cross-sectional area,
Dispersion of the cross-sectional area of the first group of the group is 0.2 ~ ² 2.0㎛, and dispersion of 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 dispersion according to the third group is greater than ² from 5.0㎛ 10.0 占 퐉 ² or less,
Wherein the dispersions of the first group to the third group are randomly arranged. 11. The method of claim 10,
The reflective polarizing film
A core layer comprising a substrate and a plurality of dispersions contained in the substrate; And
And an integrated skin layer formed on at least one side of the core layer. 11. The method of claim 10,
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. 11. The method of claim 10,
Wherein the number of dispersions of the first group is 30 to 50% and the number of dispersions of the third group is 10 to 30% among the dispersions having the aspect ratio of 1/2 or less. 11. The method of claim 10,
Wherein the ratio of the number of dispersions of the first group to the number of dispersions of the third group among the dispersions having the aspect ratio of 1/2 or less is 3 to 5: 1. 11. The method of claim 10,
Wherein the refractive index of the base material and the dispersion body is 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. The method according to claim 1,
Wherein the reflective polarizing film is stretched in at least one axial direction. The method according to claim 1,
Wherein the composite reflective polarizing film has a haze value of 65% or more. A composite reflective polarizing film comprising a reflective polarizing film in which a polymer is dispersed in a substrate,
A reliable supporting layer formed on the upper surface of the reflective polarizing film; And
And a light diffusion layer formed on the upper surface of the reliability supporting layer,
Wherein the thickness of the reflective polarizing film and the thickness of the reliability supporting layer satisfy the following relational expression (1).
[Relation 1]

A backlight unit comprising a composite reflective polarizing film according to any one of claims 1 to 18. A liquid crystal display device comprising the backlight unit according to claim 18.

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