JP6726282B2 - Composite reflective polarizing film - Google Patents

Description

The present invention relates to a composite reflective polarizing film, and more particularly, to minimize light loss and have excellent brightness, while being highly reliable even in a high heat/humidity environment during a module manufacturing process such as a display or during use. , A composite reflective polarizing film having excellent film appearance quality and remarkably excellent color reproducibility.

Flat panel display technology is mainly dominated by liquid crystal displays (LCDs), projection displays and plasma displays (PDPs), which have already secured the market in the television field, and also field emission displays (FEDs) and electroluminescence displays (ELDs). Is expected to occupy the field by each characteristic as the related technology improves. Liquid crystal displays are currently used in notebook PCs, personal computer monitors, LCD TVs, automobiles, aircraft, etc., and account for about 85% of the flat plate market. Enjoys a boom.

Conventional liquid crystal displays place a liquid crystal and an electrode matrix between a pair of light absorbing optical films. In a liquid crystal display, the liquid crystal portion has an optical state that is changed by causing the electric field generated by applying a voltage to the two electrodes to move the liquid crystal portion. Such a process displays an image by using polarized light in a specific direction for "pixels" having information. For this reason, liquid crystal displays include front and back optical films that induce polarization.

Optical films used in such liquid crystal displays do not always have high utilization efficiency of light emitted from a backlight. This is because 50% or more of the light emitted from the backlight is absorbed by the back side optical film (absorption type polarizing film). Therefore, in a liquid crystal display, a reflective polarizing film may be installed between the optical cavity and the liquid crystal assembly in order to enhance the utilization efficiency of the backlight light.

The reflective polarizing film prevents deterioration of optical performance due to light loss, and at the same time, the reflective polarizing film is slimmed according to the thickness of the display panel to be slimmed, which simplifies the manufacturing process and causes defects in the manufacturing process. Continued research continues in the direction of minimization, productivity and economics.

FIG. 1 is a diagram showing the optical principle of a conventional reflective polarizing film. Specifically, the P-polarized light of the light traveling toward the optical cavity robbed liquid crystal assembly is transmitted to the liquid crystal assembly through the reflective polarization film, and the S-polarized light is reflected from the reflective polarization film to the optical cavity. The light is reflected by the diffuse reflection surface of the optical cavity in a randomized polarization direction, is further transmitted to the reflective polarization film, and eventually the S polarization is converted into P polarization that can pass through the polarizer of the liquid crystal assembly. After passing through the reflective polarizing film, the light is transmitted to the liquid crystal assembly.

The selective reflection of S-polarized light and the transmission of P-polarized light with respect to the incident light of the reflective polarizing film are performed by a flat optical layer having an anisotropic refractive index and a flat optical layer having an isotropic refractive index. This is made by the difference in the refractive index between the optical layers in the state of being alternately laminated with each other, the setting of the optical thickness of each optical layer and the change of the refractive index of the optical layers by the extension treatment of the laminated optical layers.

That is, the light incident on the reflective polarizing film repeats the reflection action of S-polarized light and the transmission action of P-polarized light while passing through each optical layer, and eventually only P-polarized light of the incident polarized light is transmitted to the liquid crystal assembly. On the other hand, as described above, the reflected S-polarized light is reflected by the diffuse reflection surface of the optical cavity with the polarization state being randomized, and is further transmitted to the reflective polarizing film. As a result, it is possible to reduce power loss as well as loss of light generated from the light source.

However, in such a conventional reflective polarizing film, flat plate-shaped isotropic optical layers and anisotropic optical layers having different refractive indexes are alternately laminated and subjected to stretching treatment to selectively reflect and transmit incident polarized light. Since the reflective polarizing film is manufactured to have an optical thickness and a refractive index between the respective optical layers that can be optimized, the manufacturing process of the reflective polarizing film is complicated. In particular, since each optical layer of the reflective polarizing film has a flat plate structure and P-polarized light and S-polarized light must be separated corresponding to a wide range of incident angles of incident polarized light, the number of laminated optical layers is There was a problem that the production cost increased exponentially due to excessive increase. In addition, there is a problem that optical performance may be deteriorated due to light loss due to a structure in which the number of laminated optical layers is excessively formed.

FIG. 2 is a cross-sectional view of a conventional multilayer reflective polarizing film (DBEF). Specifically, in the multilayer reflective polarizing film, the skin layers 9 and 10 are formed on both surfaces of the base material 8. The base material 8 is divided into four groups 1, 2, 3, and 4, and each group is formed by alternately laminating isotropic layers and anisotropic layers to form approximately 200 layers. Meanwhile, separate adhesive layers 5, 6, and 7 are formed between the four groups 1, 2, 3, and 4 that form the substrate 8. Also, since each group has a very thin thickness, in and out of 200 layers, if these groups are individually co-extruded, each group may be damaged, so that each group is protected by a protective layer ( PBL) was included in many cases. In this case, there has been a problem that the thickness of the base material is increased and the manufacturing cost is increased. In addition, in the case of the reflective polarizing film included in the display panel, the thickness of the base material is limited for slimming. Therefore, when the adhesive layer is formed on the base material and/or the skin layer, only the thickness of the adhesive layer is formed. Since the amount of the base material is reduced, there is a problem that the improvement of optical properties is not very good. Furthermore, since the inside of the base material and the base material and the skin layer are bonded by the adhesive layer, there is a problem that the delamination phenomenon occurs when an external force is applied, a long time has passed, or the storage location is not good. there were. In addition, there is a problem that not only the defective rate becomes excessively high in the process of attaching the adhesive layer, but also destructive interference with the light source occurs due to the formation of the adhesive layer.

Skin layers 9 and 10 are formed on both surfaces 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 to bond them. When a conventional polycarbonate skin layer and a base material in which PEN-coPEN are alternately laminated are integrated through co-extrusion, peeling may occur due to the lack of compatibility, and a stretching process is performed with 55% crystallinity inside and outside. At this time, there is a high risk of birefringence with respect to the extension axis. Along with this, in order to apply the polycarbonate sheet in the non-stretching step, there was no choice but to form an adhesive layer. As a result, the addition of the adhesive layer process causes a decrease in yield due to the occurrence of external foreign matter and process defects.Usually, when a polycarbonate unstretched sheet with a skin layer is produced, birefringence due to uneven shear pressure due to the winding process occurs. However, to control this, additional control such as deformation of the polymer molecular structure and speed control of the extrusion line is required, which causes a decrease in productivity.

The conventional method for manufacturing a multilayer reflective polarizing film will be briefly described. Four groups having different average optical thicknesses forming a substrate are separately co-extruded, and then four more co-extruded four groups. After stretching the group, the four stretched groups are bonded with an adhesive to produce a substrate. This is because if the base material is stretched after the adhesive is adhered, a peeling phenomenon occurs. Then, skin layers are adhered to both surfaces of the base material. After all, in order to form a multi-layered structure, a two-layered structure is folded to form a four-layered structure, and a group (209 layers) is formed through a process of forming a multi-layered structure of a continuous folding method. Since coextrusion does not change the thickness, it is difficult to form groups inside the multilayer in one step. As a result, in reality, four groups having different average optical thicknesses must be coextruded separately and then bonded together.

Since the above process is performed intermittently, the manufacturing cost is significantly increased, and as a result, the cost is the highest among all the optical films included in the backlight unit. Along with this, from the viewpoint of cost reduction, there has been a serious problem in that liquid crystal displays excluding the reflective polarizing film are frequently released even though the reduction in brightness is reduced.

Along with this, instead of a multilayer reflective polarizing film, we propose a reflective polarizing film in which a birefringent polymer that extends in the length direction is arranged inside the substrate to disperse a dispersion that can achieve the function of the reflective polarizing film. Was done. FIG. 3 is a perspective view of the reflective polarizing film 20 including a rod-shaped polymer, in which a birefringent polymer 22 extending in the length direction is arranged in one direction inside a substrate 21. Through this, the light modulation effect can be induced by the birefringent interface between the base material 21 and the birefringent polymer 22 to perform the function of the reflective polarizing film. However, since the light in the entire visible light wavelength region is less likely to be reflected as compared with the above-mentioned alternately laminated reflective polarizing films, there arises a problem that the light modulation efficiency is very poor. Accordingly, in order to have a transmittance and a reflectance similar to those of the reflective polarizing films that are alternately laminated, there is a problem that an excessively large number of birefringent polymers 22 must be arranged inside the substrate. Specifically, in the case of manufacturing a display panel having a width of 32 inches based on the vertical cross section of the reflective polarizing film, the width is 1580 mm, and the height (thickness) is 400 μm or less. In order to have optical properties similar to those of the reflective polarizing film, a minimum of 100 million or more circular or elliptical birefringent polymers 22 having a cross-sectional diameter in the length direction of 0.1 to 0.3 μm should be included. However, in this case, not only the production cost becomes excessively high, but also the equipment becomes excessively complicated, and it is almost impossible to manufacture the equipment for producing this, so that it is difficult to be commercialized. There was a problem. In addition, since it is difficult to form the optical thickness of the birefringent polymer 22 included in the sheet in various ways, it is difficult to reflect light in the entire visible light region, which causes a problem that physical properties are reduced. ..

In order to overcome this, a technical idea including a birefringent sea-island thread inside the substrate has been proposed. FIG. 4 is a cross-sectional view of a birefringent sea-island thread contained inside a base material, wherein the birefringent sea-island thread generates a light modulation effect at a light modulation interface between an inner island part and a sea part. Therefore, unlike the birefringent polymer described above, optical physical properties can be achieved without arranging a very large number of sea-island threads. However, since the birefringent sea-island yarn is a fiber, there are problems in compatibility with the polymer base material, ease of handling, and adhesion. As a result, light scattering is induced due to the circular shape, the reflection polarization efficiency for light wavelengths in the visible light region decreases, the polarization characteristics deteriorate compared to existing products, and there is a limit to improving brightness. In addition, in the case of the sea-island thread, the sea component region is subdivided while reducing the island bonding phenomenon, so light leakage due to the generation of pores, that is, a factor of deterioration of light characteristics due to the light loss phenomenon occurred. .. In addition, there is a problem in that the structure is formed in the form of a woven fabric, and there is a limit in improving reflection and polarization characteristics due to the limit of the layer structure. In addition, in the case of the dispersion-type reflective polarizing film, there was a problem that the visibility of bright lines was observed due to the distance between layers and the space between the dispersions.

As described above, the reflective polarizing films proposed to date each have all disadvantages, and in particular, the multilayer reflective polarizing film has a remarkably high manufacturing cost, so that it is difficult to use it in an actual product. However, there is a problem that the product cost is increased, and there are problems such as poor quality due to the intervention of foreign substances that occur while joining multiple layers, complexity of the manufacturing process, and decrease in brightness due to the inclusion of too many adhesive layers. A polymer-dispersed reflective polarizing film in which a polymer is dispersed inside a substrate is more preferable.

However, in the polymer-dispersed reflective polarizing film developed to date, since the base material is semi-transparent, the appearance defect rate is high as foreign matter is expressed in the appearance of the film, light leakage, and the phenomenon of bright line visibility, Since the wide viewing angle is narrow and the light loss cannot be minimized, there is a problem that the brightness is lowered.

In addition, reliability is remarkable such that the reflective polarizing film is bent due to high heat conditions applied in the process of manufacturing the reflective polarizing film in a module such as a backlight unit and/or heat generated in the environment in which such a module is used. There was a problem to decrease.

Consequently, in order to solve such a problem, even in the case of a composite film in which a separate structure is added to the polymer-dispersed reflective polarizing film, the problem of reliability deterioration occurring in the reflective polarizing film still remains unsolved. However, if the appearance of foreign matter is reduced, at the same time, there is a problem that the brightness is significantly reduced.If the decrease in brightness is minimized, it is difficult to prevent the appearance of foreign matter from occurring. I could not be satisfied at the same time.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has a minimum light loss and excellent brightness, and at the same time, in a module manufacturing process such as a display or in a high heat/humidity environment during use. Another object of the present invention is to provide a method for producing a composite reflective polarizing film having excellent reliability, excellent film appearance quality, and remarkably excellent color reproducibility.

In order to solve the above-described problems, the present invention is a composite reflective polarizing film including a reflective polarizing film having a polymer dispersed inside a substrate, wherein the composite reflective polarizing film is formed on an upper surface of the reflective polarizing film. A composite reflective polarizing film comprising: a light diffusing layer; and a reliability supporting layer formed on the lower surface of the reflective polarizing film; and satisfying the following conditions (1) and (2).

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

According to a preferred embodiment of the present invention, the light diffusion layer comprises at least one fine pattern selected from the group consisting of prisms, lenticulars, microlenses, triangular pyramids and pyramid patterns; and bead coating. It may include any one or more of layers. Here, the fine pattern may include a micro lens.

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

According to another preferred embodiment of the present invention, the reliability support layer may have a thickness of 10 to 600 μm.

According to another preferred embodiment of the present invention, under the condition (1), the reliability supporting layer may satisfy a coefficient of linear expansion of 10 to 25 μm/m·° C. in a temperature range of 70 to 80° C.

According to still another preferred embodiment of the present invention, the reflective polarizing film includes a base material, a first polarized light included in the base material, which transmits an externally emitted first polarized light, and reflects a second polarized light. A plurality of dispersions for allowing the plurality of dispersions to have a refractive index different from that of the base material in at least one axial direction, among the plurality of dispersions contained in the base material. 80% or more have an aspect ratio of the length of the minor axis to the length of the major axis of 1/2 or less based on the vertical cross section in the longitudinal direction, and the dispersion having the aspect ratio of 1/2 or less is Depending on the area, it may be included in at least three groups, the first group of the dispersions has a cross-sectional area of 0.2 to 2.0 μm ² , and the second group of the dispersions may have a cross-sectional area of 2. 0μm is ² from exceeding 5.0 .mu.m ² or less, the cross-sectional area of the dispersion of the third group is a 10.0 [mu] m ² or less from 5.0 .mu.m ² exceeded, dispersions of the first group to third group, It may be arranged at random.

According to another preferred embodiment of the present invention, a core layer including a substrate and a plurality of dispersions contained in the substrate; and an integrated layer formed on at least one surface of the core layer. A skin layer;

According to another preferred embodiment of the present invention, the haze value of the composite reflective polarizing film under the condition (2) may be 73% or more.

Further, the present invention provides a composite reflective polarizing film including a reflective polarizing film in which a polymer is dispersed inside a substrate, wherein the composite reflective polarizing film is a reliability supporting layer formed on an upper surface of the reflective polarizing film; And a light diffusing layer formed on the upper surface of the reliability supporting layer, which satisfies the following conditions (1) and (2).

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

The present invention also provides a composite reflective polarizing film including a reflective polarizing film having a polymer dispersed inside a substrate, wherein the composite reflective polarizing film is a light diffusing layer formed on an upper surface of the reflective polarizing film; And a reliability supporting layer formed on the upper surface of the diffusion layer, which satisfies the following conditions (1) and (2).

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

The present invention also provides a composite reflective polarizing film including a reflective polarizing film having a polymer dispersed inside a substrate, wherein the composite reflective polarizing film includes a light diffusion layer formed on an upper surface of the reflective polarizing film; A reliability support layer formed on the lower surface of the polarizing film; and a light-collecting layer formed on the lower surface of the reliability support layer; and satisfying the following conditions (1) and (2): And a composite reflective polarizing film.

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

According to a preferred embodiment of the present invention, the light collecting layer includes a support part and a prism pattern formed on the support part, and the prism pattern part faces a lower surface of the reliability support layer. Can be formed as.

According to another preferred embodiment of the present invention, the supporting part may have a thickness of 10 to 300 μm.

The present invention also provides a composite reflective polarizing film including a reflective polarizing film having a polymer dispersed inside a substrate, wherein the composite reflective polarizing film includes a light diffusion layer formed on an upper surface of the reflective polarizing film; A reliability supporting layer formed on the lower surface of the polarizing film; and a light collecting layer including a supporting portion and formed on the lower surface of the reliability supporting layer; Provided is a composite reflective polarizing film, wherein the value of the following mathematical formula 1 with respect to the thickness of the layer and the thickness of the support of the light collecting layer is 0.3 to 2.0.

According to a preferred embodiment of the present invention, the value of Equation 2 below with respect to the thickness of the reliability support layer and the thickness of the support portion of the light collection layer may be 0.25 to 4.

On the other hand, the present invention provides a composite reflective polarizing film comprising a reflective polarizing film in which a polymer is dispersed inside a substrate, wherein the composite reflective polarizing film is a light diffusing layer formed on an upper surface of the reflective polarizing film; A reliability support layer formed on the lower surface of the polarizing film; and a multi-functional layer formed under the reliability support layer for guiding and collecting light emitted from a light source. Provided is a composite reflective polarizing film which satisfies (1) and condition (2).

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

According to a preferred embodiment of the present invention, the multi-functional layer includes a fine pattern layer that collects light emitted from a light source; a fine pattern layer formed under the fine pattern layer, supporting the fine pattern layer and a light source. A light guide layer for guiding the irradiated light;

The present invention also provides a backlight unit including the composite reflective polarizing film according to the present invention.

Consequently, the present invention provides a liquid crystal display device including the backlight unit according to the present invention.

The terms used in this specification will be described below.

As used herein, the term "dispersion having birefringence" means that when light is applied to a fiber having a different refractive index depending on the direction, the light incident on the dispersion is equal to or greater than two lights with different directions. Means to be refracted by.

The term "isotropic" as used herein means that the index of refraction of light as it passes through an object is constant regardless of direction.

The term "anisotropic" used in this specification means that an optical property of an object is different depending on a direction of light, and an anisotropic object has birefringence and isotropic property. Corresponding to.

As used herein, the term "light modulation" means that the emitted light is reflected, refracted, scattered, or the light intensity, the period of waves, or the nature of light is changed. ..

The term "aspect ratio" as used herein means the ratio of the length of the minor axis to the length of the major axis with respect to the vertical cross section of the length of the dispersion.

As used herein, the spatially relative terms "below," "beneath," "lower," "above," " “Upper” and the like can be used to easily describe the correlation of one component with another, as shown in the drawing. Spatial relative terms should be understood as terms that include different orientations of the components during use or operation, in addition to the orientation shown in the drawings. For example, when flipping a component shown in the drawing, a component described as "below" or "beneath" of another component is "above" another component. Can be placed. Thus, the exemplary term "below" can include both an orientation of above and below. The components can be oriented in other directions as well, with which the spatially relative terms can be interpreted by orientation.

In addition, such spatially relative terms “upper”, “upper”, “upper”, “lower”, “lower” and “lower” are “directly” and “indirectly”. (Indirectly) is included.

The method for manufacturing the composite reflective polarizing film according to the present invention minimizes light loss and has excellent brightness, and at the same time, the film is distorted or wrinkled even in a module manufacturing process such as a display or in a high heat/humidity environment during use. There is no appearance change such as occurrence, it is excellent in reliability, and there are no defects such as foreign matter appearing in the film appearance, light leakage, bright lines, etc., so it is excellent in quality and outstanding in color reproducibility. Suitable for manufacturing.

It is a schematic diagram explaining the principle of the conventional reflective polarizing film. It is sectional drawing of the multilayer reflective polarizing film (DBEF) currently used. It is a perspective view of the reflective polarizing film containing a rod-shaped polymer. It is sectional drawing which shows the path|route of the light which injected into the birefringent sea-island thread used for a reflective polarizing film. 1 is a cross-sectional view of a composite reflective polarizing film according to a first preferred embodiment of the present invention. 1 is a cross-sectional view of a reflective polarizing film in which a dispersion is randomly dispersed inside a substrate according to a preferred embodiment of the present invention. FIG. 2 is a vertical cross-sectional view of a dispersion used in a preferred embodiment of the present invention. 1 is a perspective view of a reflective polarizing film according to a preferred embodiment of the present invention. 1 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention. 1 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention. 1 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention. 1 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention. 1 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention. 1 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention. 3 is a cross-sectional view of a light diffusion layer in a composite reflective polarizing film according to a preferred embodiment of the present invention. 3 is a cross-sectional view of a light diffusion layer in a composite reflective polarizing film according to a preferred embodiment of the present invention. 3 is a cross-sectional view of a light diffusion layer in a composite reflective polarizing film according to a preferred embodiment of the present invention. 1 is a cross-sectional view of a composite reflective polarizing film according to a preferred embodiment of the present invention. FIG. 3 is a cross-sectional view of a coat-hanger die, which is one type of preferable flow control unit applicable to the present invention. It is a side view of FIG. 3 is a schematic view of a fine pattern forming process according to a preferred embodiment of the present invention. It is sectional drawing which shows the detailed structure of the shaping|molding part of FIG. 6 is a schematic view of a fine pattern forming process according to another exemplary embodiment of the present invention. 6 is a schematic view of a fine pattern forming process according to another exemplary embodiment of the present invention. FIG. 3 is a cross-sectional view of a reflective film and a reliability support layer that are stacked according to a preferred embodiment of the present invention. FIG. 6 is a cross-sectional view of a composite reflective polarizing film according to a second preferred embodiment of the present invention. 1 is a perspective view of a light collecting layer included in a preferred embodiment of the present invention. 6 is a schematic view of a process of forming a fine pattern of a light collecting layer according to a preferred embodiment of the present invention. 6 is a schematic view of a process of forming a fine pattern of a light collecting layer according to a preferred embodiment of the present invention. 1 is a cross-sectional view of a liquid crystal display device according to a preferred embodiment of the present invention. 1 is a liquid crystal display device using a composite reflective polarizing film according to a preferred embodiment of the present invention. 1 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. 1 is a perspective view showing a joint structure of a die-distributor plate of a sea-island type extrusion die capable of producing a plate-shaped polymer dispersed reflective polarizing film included in a preferred embodiment of the present invention. 1 is a cross-sectional view of a plate-shaped polymer dispersed reflective polarizing film according to a preferred embodiment of the present invention.

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

As described above, the polymer-dispersed reflective polarizing film has a semi-transparent base material, and thus has a high defect rate in appearance as foreign matter is expressed in the film appearance, and light leakage, a bright line visual recognition phenomenon, and a wide viewing angle. Has a problem in that the light loss cannot be minimized and the brightness is reduced due to the narrow width, and the high heat condition and/or the high heat condition applied in the process of manufacturing the reflective polarizing film in a module such as a backlight unit. There is a problem that the reliability is remarkably reduced such that the reflective polarizing film is bent due to the heat generated in the environment in which such a module is used. Consequently, in order to solve such a problem, even in the case of a composite film in which a separate structure is added to the polymer-dispersed reflective polarizing film, the problem of reliability deterioration occurring in the reflective polarizing film still remains unsolved. However, if the appearance of foreign matter is reduced, at the same time, there is a problem that the brightness is significantly reduced.If the decrease in brightness is minimized, it is difficult to prevent the appearance of foreign matter from occurring. I could not be satisfied at the same time.

Therefore, in the first embodiment of the present invention, in the composite reflective polarizing film including the reflective polarizing film in which the polymer is dispersed in the base material, the composite reflective polarizing film is a light formed on the upper surface of the reflective polarizing film. A composite reflective polarizing film comprising: a diffusion layer; and a reliability supporting layer formed on the lower surface of the reflective polarizing film; and satisfying the following conditions (1) and (2). , Sought to solve the problems mentioned above. Through this, the light loss is minimized and the brightness is excellent.At the same time, the film is not distorted or wrinkled even in a module manufacturing process such as a display or in a high heat/humidity environment during use. It is excellent in reliability and has no defects such as appearance of foreign matter in the film appearance, light leakage, and generation of dotted lines, so that the quality is excellent and the color reproducibility can be remarkably improved.

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

Referring to FIG. 5, the composite reflective polarizing film 1000 according to the first embodiment is formed on the light diffusing layer 100 formed on the upper surface of the reflective polarizing film 200 and the lower surface of the reflective polarizing film 200. A reliable support layer 300 may be included, and a first primer layer 400 may be included between the reflective polarizing film 200 and the reliable support layer 300 to enhance adhesion.

First, the reflective polarizing film 200 will be described.

The reflective polarizing film 200 may be a normal polymer-dispersed reflective polarizing film having a polymer dispersed inside a substrate. The ordinary polymer jet reflective polarizing film may be a known and conventional reflective polarizing film containing a rod-shaped polymer as shown in FIG. 3, and the present invention includes the shape of the polymer dispersed in the substrate and the number of polymers. The dispersion form is not particularly limited.

However, as described above, the reflective polarizing film in which the polymer is dispersed inside the conventional substrate has light leakage, a phenomenon of visual recognition of bright lines, a wide viewing angle is narrow, and light loss cannot be minimized. There was a problem of deterioration.

Accordingly, according to a preferred embodiment of the present invention, the reflective polarizing film transmits the first polarized light, which is included in the base material and the base material and is externally irradiated, and reflects the second polarized light. A plurality of dispersions for allowing the plurality of dispersions to have a refractive index different from that of the base material in at least one axial direction, among the plurality of dispersions contained in the base material. 80% or more have an aspect ratio of the length of the minor axis to the length of the major axis of 1/2 or less based on the vertical cross section in the longitudinal direction, and the dispersion having the aspect ratio of 1/2 or less is Depending on the area, it may be included in at least three groups, the first group of the dispersions has a cross-sectional area of 0.2 to 2.0 μm ² , and the second group of the dispersions may have a cross-sectional area of 2. 0μm is ² from exceeding 5.0 .mu.m ² or less, the cross-sectional area of the dispersion of the third group is a 10.0 [mu] m ² or less from 5.0 .mu.m ² exceeded, dispersions of the first group to third group, It can be arranged randomly.

In addition, according to another preferred embodiment of the present invention, the reflective polarizing film includes the above-mentioned substrate and a plurality of dispersions satisfying the conditions according to the preferred embodiment of the present invention. A reflective polarizing film including a body may be used as a core layer, and a structure including an integrated skin layer formed on at least one surface of the core layer may be included. By further including a skin layer, the core layer may be protected. Can contribute.

The reflective polarizing film according to one embodiment that does not include a skin layer and the reflective polarizing film according to another embodiment that includes a skin layer may be different in use. In the case of portable liquid crystal display devices, such as portable electronic devices, smart electronic devices, and smartphones, it is preferable to use a reflective polarizing film that does not include a skin layer, but is not limited thereto. Absent.

On the other hand, the composite reflective polarizing film according to the present invention includes the reliability supporting layer described below on one surface of the reflective polarizing film so that the composite reflective polarizing film can protect the core layer even if it does not have a skin layer for protecting the core layer. Can also be achieved.

The reflective polarizing film including the skin layer will be specifically described below.

Referring to FIG. 6, a core layer 210 in which a plurality of dispersion bodies 202 to 207 are randomly dispersed and arranged inside a base material 201, and a skin layer integrally formed on at least one surface of the core layer 210. A reflective polarizing film including 220 may be implemented.

In the core layer 210, 80% or more of the plurality of dispersions contained in the base material have an aspect ratio of a length of a short axis to a length of a long axis with reference to a vertical cross section in the length direction. May be 1/2 or less, and more preferably 90% or more can satisfy the aspect ratio value of 1/2 or less.

Specifically, FIG. 7 is a vertical cross-section of a dispersion used in a preferred embodiment of the present invention, in which the length of the major axis is a and the length of the minor axis is b. In this case, the relative length ratio (aspect ratio) of the major axis length (a) and the minor axis length (b) may be 1/2 or less. In other words, when the length (a) of the major axis is 2, the length (b) of the minor axis may be smaller than or equal to 1 which is 1/2 thereof, or may be the same. If the ratio of the length of the short axis to the length of the long axis is more than 1/2 in the total number of the dispersions in an amount of 20% or more, it is difficult to achieve desired optical properties. ..

The dispersion having an aspect ratio of ½ or less may include three or more groups having different cross-sectional areas. Referring to FIG. 6, the first group of dispersions 202, 203 having the smallest cross-sectional area and the second group of dispersions 204, 205 having a medium cross-sectional area and the third group having the largest cross-sectional area. All of the dispersions 206 and 207 are randomly dispersed. In this case, the cross-sectional area of the first group is 0.2 to 2.0 [mu] m ^2, the cross-sectional area of the second group is from 2.0 .mu.m ² exceeding 5.0 .mu.m ² or less, the cross-sectional area of the third group is at 10.0 [mu] m ² or less from 5.0 .mu.m ² exceeded, dispersions of the first group, the dispersion of the dispersion, and a third group of the second group are arranged at random. If the dispersion of any one of the dispersions of the first to third groups is not included, it is difficult to achieve desired optical properties (see Table 1).

In this case, preferably, the number of the 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, among the dispersions having an aspect ratio of 1/2 or less, the number of dispersions corresponding to the first group satisfies 30 to 50%, and the number of dispersions corresponding to the third group is 10 to 30%. The optical properties can be improved through this (see Table 1).

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

Preferably, the number of the dispersions corresponding to the second group among the dispersions having the aspect ratio of 1/2 or less can satisfy 25 to 45%. Further, a dispersion having a cross-sectional area outside the range of the first to third dispersions may be included as a residual amount in the dispersion having an aspect ratio of 1/2 or less. As a result, it is possible to maximize the improvement in brightness while improving the visibility of bright lines as compared with the conventional dispersion-type reflective polarizing film, wide viewing angle, and minimizing light loss.

FIG. 8 is a perspective view of a reflective polarizing film included in a preferred embodiment of the present invention, in which a plurality of random dispersions 208 extend in a length direction inside a base material 201 of a core layer 210. The skin layer 220 is formed on the upper portion and/or the lower portion of the core layer 210. In this case, each of the random dispersions 208 may extend in various directions, but it is advantageous that the random dispersions 208 extend in parallel to any one of the directions, more preferably perpendicular to the light emitted from the external light source. Stretching parallel to the stretched body in the direction of rotation is effective in maximizing the light modulation effect.

In addition, according to a preferred embodiment of the present invention, a birefringent interface may be formed between the dispersion (first component) and the substrate (second component) contained inside the substrate. Specifically, in a reflective polarizing film including a dispersion inside a substrate, the size of the substantial match or mismatch of the refractive indices according to the X, Y and Z axes in the space between the substrate and the dispersion is determined by the axis. Affects the degree of scattering of light polarized along. Generally, the scattering power varies in proportion to the square of the refractive index mismatch. Therefore, the greater the degree of refractive index mismatch along a particular axis, the more strongly the rays polarized along that axis will be scattered. Conversely, if the discrepancy due to a particular axis is small, rays polarized along that axis will be scattered to a lesser extent. When the index of refraction of the substrate substantially matches the index of refraction of the dispersion by any axis, incident light polarized into an electric field parallel to such axis is related to the size, morphology and density of the parts of the dispersion. Pass through the dispersion without scattering without scattering. Also, if the indices of refraction along that axis are substantially matched, the ray of light is substantially unscattered and passes through the object. More specifically, the first polarized light (P-wave) is transmitted without being affected by the birefringent interface formed at the boundary between the base material and the dispersion, while the second polarized light (S-wave) is transmitted by the base material. Light modulation occurs due to the influence of the birefringent interface formed at the boundary between the dispersions. Through this, the P wave is transmitted, and the S wave undergoes light modulation such as scattering and reflection of light, and eventually polarization is separated.

Therefore, when the substrate and the dispersion form a birefringent interface, a light modulation effect can be induced. Therefore, when the substrate is optically isotropic, the dispersion has a birefringence. If, on the contrary, the substrate is optically birefringent, the dispersion can be optically isotropic. Specifically, the dispersion has a refractive index nX _{1 in} the x-axis direction, a refractive index nY _{1 in} the y-axis direction and a refractive index nZ ₁ in the z-axis direction, and the refractive indices of the base material are nX ₂ and nY. _{When 2} and nZ ₂ , in-plane birefringence between nX ₁ and nY ₁ can occur. More preferably, at least one of the X-, Y-, and Z-axis refractive indices of the base material and the dispersion may be different, and more preferably, when the elongation axis is the X-axis, refraction in the Y-axis and Z-axis directions is performed. The difference in refractive index may be 0.05 or less, and the difference in refractive index in the X-axis direction may be 0.1 or more. On the other hand, if the difference in refractive index is 0.05 or less, it is usually interpreted as matching.

Further, in the present invention, the thickness of the core layer is preferably 20 to 350 μm, more preferably 50 to 250 μm, but is not limited thereto, and specific applications and inclusion of the skin layer. The thickness of the core layer may be designed differently depending on the thickness of the skin layer. Also, the number of the total dispersion may be 25,000,000 to 80,000,000 when the thickness of the substrate is 120 μm based on 32 inches, but is not limited thereto.

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

The skin layer component can be used without limitation as long as it is a component that is usually used and is usually used in a reflective polarizing film, but preferably polyethylene naphthalate (PEN) and copolyethylene naphthalate (co- PEN), polyethylene terephthalate (PET), polycarbonate (PC), polycarbonate (PC) alloy, polystyrene (PS), heat-resistant polystyrene (PS), polymethyl methacrylate (PMMA), polybutylene terephthalate (PBT), polypropylene (PP), Polyethylene (PE), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile mixture (SAN), ethylene vinyl acetate (EVA), polyamide (PA), polyacetal (POM) ), phenol, epoxy (EP), iodine (UF), melanin (MF), unsaturated polyester (UP), silicone (SI) and cycloolefin polymers can be used alone or in combination, more preferably dimethyl. It may be co-PEN in which monomers such as -2,6-naphthalenedicarboxylate, dimethyl terephthalate and ethylene glycol, cyclohexanedimethanol (CHDM) are appropriately polymerized.

According to a preferred embodiment of the present invention, the skin layer may have a thickness of 30 to 500 μm, 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, not only the deterioration of optical properties due to the adhesive layer can be prevented, but more layers can be added to the limited thickness, so that the optical properties can be remarkably improved. Consequently, the skin layer is produced at the same time as the core layer, and then the stretching step is performed.Thus, unlike the case of adhering the unstretched skin layer after stretching the conventional core layer, the skin layer of the present invention is It may be stretched in at least one axial direction. Through this, the surface hardness is improved, the scratch resistance is improved, and the heat resistance is improved as compared with the unstretched skin layer.

Next, the light diffusion layer 100 formed on the upper surface of the reflective polarizing film 200 described above will be described. The light diffusion layer 100 can improve the light collection effect, prevent irregular reflection on the surface and significantly increase the brightness, and increase the haze value of the composite reflective polarizing film through the scattering of light to increase the haze value. It is possible to minimize the appearance defect in which foreign matter appears. The light diffusion layer 100 may be formed on the reflective polarizing film 200 or an adhesive layer (not shown) formed on the reflective polarizing film 200.

The light diffusion layer 100 may include a fine pattern. The fine pattern is not particularly limited in specific structure as long as it is a fine pattern capable of simultaneously improving the brightness, the light-collecting effect and the haze value of the composite reflective polarizing film, but more preferably the fine pattern is , Prisms, lenticulars, microlenses, triangular pyramids, and pyramid patterns, each of which may include one or more patterns, each of which may be individually patterned or combined. It may be formed by any of the above, and may be one or more of a lenticular lens, a microlens, and a prism, and more preferably a microlens capable of simultaneously satisfying all the physical properties.

Specifically, FIG. 9 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention, wherein the reflective polarizing film 200 has a plurality of dispersions extending in a longitudinal direction inside a substrate. And these form the core layer 210. In this case, the dispersion may extend in various directions, but it is advantageous to extend in parallel to any one direction, and more preferably, the direction perpendicular to the light emitted from the external light source. Stretching parallel to each other is effective in maximizing the light modulation effect. The light diffusion layer 100 formed on the reflective polarizing film 200 may include a fine pattern to perform an improved light condensing function and a brightness enhancement function. FIG. 9 illustrates a light diffusion layer including a lenticular pattern. 110 is shown.

More specifically, the lenticular pattern may have a height h of 10 to 50 μm. If the height of the lenticular pattern is less than 10 μm, it may be difficult to implement the pattern. If the height of the lenticular pattern exceeds 50 μm, the brightness may decrease due to an increase in the total reflection amount of light.

The lenticular pitch may be 20 to 100 μm. If the pitch of the lenticular pattern is less than 20 μm, the condensing effect of the lens shape is somewhat inferior due to the increase of the valley portion of the film per unit area, and the precision of the shape processing is limited and the pattern shape is too narrow. However, if the thickness exceeds 100 μm, the possibility of moire between the pattern structure and the panel becomes very large.

On the other hand, when the minor axis radius of the elliptical cross section is defined as c and the major axis radius is defined as d per lenticular lens, the major axis/minor axis (b/a) ratio must satisfy 1.0 to 3.0. You can If the ratio of the major axis/minor axis (d/c) is out of the above range, there may be a problem that the efficiency of hiding the bright lines for the light passing through the birefringent polarizing layer is poor.

Further, when defining the height h of the lenticular lens, the tangent angle α at both end points of the lower end of the lens must satisfy the range of 30 to 80°. At this time, if α is smaller than 30°, the bright line hiding efficiency is poor, and if it is larger than 80°, it is difficult to manufacture a lens pattern. When the lenticular lens has a triangular cross-sectional shape, it is preferable that the vertex angle θ satisfies 90 to 120° for the effect of hiding the bright lines.

Further, the lenticular shape may be formed with a pattern having the same height and pitch as shown in FIG. 9, or lenticular patterns 111 having different heights and pitches may be mixed as shown in FIG. 10.

Meanwhile, FIG. 11 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention, in which the light diffusion layer 112 includes a microlens pattern. To describe the microlens pattern in detail, the height of the microlens may be 10 to 50 μm. If the height of the microlens pattern is less than 10 μm, the light-collecting effect may be slightly inferior and it may be difficult to implement the pattern. If it exceeds 50 μm, the moire phenomenon is likely to occur and the pattern is visible in the image. Can occur.

In addition, the diameter of the microlens may be 20 to 100 μm. It may be preferably 30 to 60 μm. Within the above range, the appearance characteristics are good, and the microlens condensing function and light diffusion characteristics are excellent, so that actual manufacturing can be facilitated. If the diameter of the microlens pattern is less than 20 μm, there may be a problem of low light collection efficiency for incident light incident at an invalid angle, and if it exceeds 100 μm, the light collection efficiency for vertical light may decrease. However, the problem of the moire phenomenon may occur.

Further, the microlens pattern may also be formed with a pattern having the same height and diameter as shown in FIG. 11, or the microlens patterns 113 having different heights and diameters may be mixed as shown in FIG. Such a microlens pattern has a large difference in optical characteristics depending on the density (Density) and the impregnation degree (Aspect Ratio) of the lens. Therefore, the density is maximized and the impregnation degree may be 1/2. Ideal.

Meanwhile, FIG. 13 is a perspective view of a composite reflective polarizing film according to a preferred embodiment of the present invention, in which the light diffusion layer 113 includes a prism pattern. To describe the prism pattern in detail, the height h of the prism may be 10 to 50 μm. If the height of the prism pattern is less than 10 μm, the base film may be damaged by pressure when manufacturing the shape of the prism pattern part, and if it exceeds 50 μm, the transmittance of light incident on the light source may be increased. The problem of diminishing can occur.

In addition, the pitch of the prism may be 20 to 100 μm. If the pitch of the prism pattern is less than 20 μm, the engraving may not be performed well, and a complicated problem may occur in the implementation and manufacturing process of the pattern layer. If the pitch exceeds 100 μm, the moire phenomenon is likely to occur and the image The problem that the pattern is visible may occur.

In addition, the prism shape may be formed by patterns 113 having the same height and pitch as shown in FIG. 13, or prism patterns 115 having different heights and pitches may be mixed as shown in FIG. Such a prism pattern may be made of a material having a higher refractive index than the base film, which means that if the base film has a higher refractive index, a part of the light incident on the rear surface of the base film will be at the surface of the prism pattern. This is because the light may be totally reflected and may not enter the prism structure. The prism shape is preferably a linear prism shape, and the vertical cross section is a triangle, and the apex of the triangle facing the lower surface forms an angle of 60 to 110°.

The light diffusion layer including the above-described fine pattern may be formed by curing by 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 photocuring acrylic resin can be used. However, the type of polymer resin used depending on the shape of the fine pattern specifically included in the light diffusion layer can be changed and used differently. For example, for the prism pattern, unsaturated fatty acid ester, aromatic vinyl compound, unsaturated fatty acid and its derivative, vinyl cyanide compound such as methacrylonitrile, etc. can be used, and specifically, urethane acrylate, methacrylic acrylate resin, etc. can be used. Can be used. Also, the light diffusion layer may be made of a material having a higher refractive index than the reflective polarizing film.

Also, according to a preferred embodiment of the present invention, the light diffusion layer may include a bead coating layer. Specifically, the bead coating layer may be a coating layer in which the beads 108 are included in the resin layer 107 (see FIG. 15), and a part of the beads is embedded in the upper portion of the resin layer (see FIG. 16). In this case, unlike the case shown in FIG. 16, the protruding beads may be different in at least a part of the beads, and the diameter of the included beads may also be different in part. Can be configured to. Further, as shown in FIG. 17, beads may be attached to the upper surface of the resin layer and/or beads may be directly attached to the upper surface of the reflective polarizing film without the resin layer. The beads may have a diameter of 0.1 to 100 μm, and when beads including such a diameter are included, excellent optical properties can be realized. In the present invention, the density of the beads and the spacing between the beads in the bead coating layer can be designed differently depending on the desired optical physical properties, and are not particularly limited in the present invention. However, when the distance between the beads is too small, the light transmission characteristics may become disadvantageous as the number of beads included per unit area increases, and the distance between the beads is preferably about 1 μm or more. , But is not limited to this.

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, and polycarbonate. Examples thereof include homopolymers and copolymers obtained by using the above monomers. Examples of the inorganic beads include silica, zirconia, calcium carbonate, barium sulfate, titanium oxide and the like.

The resin constituting the resin layer is not particularly limited in the present invention, but may be a UV curable substance, and examples of the (meth)acrylate or the polyfunctional (meth)acrylate monomer include 2-hydroxyethyl (meth). ) Acrylate, 2-hydroxypropyl(meth)acrylate, tetrahydrofurfuryl(meth)acrylate, butoxyethyl(meth)acrylate, ethyldiethylene glycol(meth)acrylate, 2-ethylhexyl(meth)acrylate, cyclohexyl(meth)acrylate, phenoxyethyl. (Meth)acrylate, dicyclopentadiene (meth)acrylate, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methyltriethylene diglycol (meth)acrylate, isobornyl (meth)acrylate, N-vinylpyrrolidone, N- Vinylcaprolactam, diacetone acrylamide, isobutoxymethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, t-octyl (meth)acrylamide, dimethylaminoethyl (meth)acrylate, acryloylmorpholine, dicyclepentenyl (meth) Acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth) Acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane trioxyethyl (meth)acrylate, tricyclodecanedi It may be methanol di(meth)acrylate, dicyclodecane dimethanol di(meth)acrylate, tripropylene glycol di(meth)acrylate, dicyclopentane di(meth)acrylate, dicyclopentadiene di(meth)acrylate, etc. The substances listed above can be used alone or in combination.

In addition to the resins listed above, an additive may be further included, and a substance having high lubricity may be applied as the additive. For example, at least one of a silicon-based additive and a fluorine-based additive may be applied. Specifically, a reactive monomer or reactive oligomer having a silicon group (for example, a silicon group-containing vinyl compound, a silicon group-containing (meth)acrylate compound, a (meth)acryloxy group-containing organosiloxane, and a silicon polyacrylate). Etc.), a reactive monomer or reactive oligomer having a fluorine group (for example, a fluoroalkyl group-containing vinyl compound, a fluoroalkyl group-containing (meth)acrylate compound, a fluorine polyacrylate, etc.), a silicon group or a fluorine group. Resins (for example, polydimethylsiloxane, fluoropolymers, etc.), surfactants or oils having silicon groups or fluorine groups (for example, dimethylsilicone oil, etc.), etc. may be applied alone or in combination.

The ratio of the UV curable material to the additive may be in the range of 100:0.001 to 100:10 by weight, preferably 100:0.01 to 100:5 by weight. It is possible. Also, a photoinitiator may be further included in addition to the UV curable material and the additive. The photoinitiator is at least one free radical initiator selected from benzyl ketals, benzoin ethers, acetophenone derivatives, ketoxime ethers, benzophenone, benzo or thioxanthone compounds, onium salts. , One or more cationic initiators selected from among ferrocenium salts, and diazonium salts, or mixtures thereof.

As described above, the degree of physical properties exhibited by the composite reflective polarizing film through the light diffusion layer 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, a light-collecting effect is obtained. Although it can be further maximized, the increase in the haze value of the composite reflective polarizing film can be relatively reduced as compared with the case of the microlens shape. In addition, when the light diffusion layer does not include a fine pattern and is a bead coating layer, it is possible to significantly increase the haze value of the composite reflective polarizing film and realize a very excellent surface appearance quality. The transmittance is significantly reduced, and the optical characteristics such as the light collecting effect and the brightness may be significantly reduced as compared with when the fine pattern, preferably the fine pattern has a microlens shape. Therefore, the shape of the light diffusing layer can be selected differently depending on the desired physical properties, but not only through optical characteristics such as light collection and brightness, but also through an increase in the haze value of the composite reflective polarizing film. In order to improve the surface appearance quality at the same time, it is more preferable that the light diffusion layer includes a microlens-shaped fine pattern.

Meanwhile, an adhesive layer (not shown) may be selectively formed on the upper surface of the skin layer 220a of the reflective polarizing film 200. Through this, the adhesive strength, appearance, and electroluminescence characteristics of the light diffusion layer 100 can be improved. As the material, acrylic, ester, urethane and the like can be used, but the material is not limited thereto. The adhesive layer may be formed thinner than the other layers, and the thickness of the adhesive layer may be adjusted to improve the light transmittance and, at the same time, reduce the reflectance. The thickness of such an adhesive layer may be 5 nm to 300 nm. If the thickness of the adhesive layer is less than 5 nm, the adhesive force between the reflective polarizing film and the light diffusion layer may be very weak. If the thickness of the adhesive layer exceeds 300 nm, unevenness may occur during the treatment of the adhesive. Molecular masses can occur.

Next, the reliability support layer 300 formed on the lower surface of the reflective polarizing film 200 will be described. The reliability support layer 300 remarkably improves the decrease in thermal reliability caused by the reflective polarizing film including the polymer dispersed in the base material in various processes for manufacturing a backlight unit and further improves haze. As a result, it is possible to remarkably improve the defective appearance in which foreign matters, bright lines, etc. are manifested in the appearance, and at the same time, minimize the decrease in brightness that may occur when a separate structure is included for improving reliability.

In the description of the present invention, the reliability of the composite reflective polarizing film means that the reflective polarizing film usually has a very high coefficient of linear expansion due to the characteristics of its material, and the composite reflective polarizing film, a process for manufacturing a module such as a backlight unit. The surface of the reflective polarizing film is affected by the high temperature in a hot and humid environment of the product to which it is applied and the optical properties such as the change in appearance such as wrinkles like curtains, bending, and/or the resulting decrease in brightness. If there is no unevenness of the panel due to the difference in the pores between the crests and the troughs of the wrinkles due to the appearance of wrinkles and bends in the appearance, and the reflective polarizing film stretches in at least one axis, stretching This means that there is no visual damage such as easy bursting or damage in the specified direction.

The composite reflective polarizing film according to the present invention remarkably improves the reliability as described above, and at the same time, in order to maintain optical properties such as brightness, the reliability support layer according to the present invention has the condition (1) according to the present invention. As a linear expansion coefficient of 4 to 35 μm/m·° C. in the temperature range of 70 to 80° C., preferably a linear expansion coefficient of 10 to 25 μm/m·° C. in the temperature range of 70 to 80° C. Can be satisfied. In order to meet this, even in the high temperature and high humidity environment of the module manufacturing process such as the composite reflective polarizing film and the backlight unit and/or the high temperature and high humidity environment of the product to which this is applied, the reflective polarizing film may change its appearance due to high temperature and/or change in appearance. Alternatively, the excellent composite reflective polarizing film can be made to have excellent reliability in order to prevent the deterioration of the optical properties caused thereby. If the above range is not satisfied, there may be a problem in that desired physical properties such as optical characteristics, reliability, and prevention of surface appearance defect cannot be realized. Specifically, when the linear expansion coefficient exceeds 35 μm/m·° C. in the temperature range of 70 to 80° C., such a problem may be further deepened, and thus it is not used as a composite reflective polarizing film in a backlight unit. However, when the coefficient of linear expansion is less than 4 μm/m·°C, it is excellent in terms of reliability, but it is difficult to develop a material that has such thermal characteristics and excellent optical characteristics at the same time. However, even if it is developed, it is very expensive, and there is a problem that it is difficult to select it in terms of production cost.

On the other hand, the material of the reliability support layer is not limited as long as it satisfies the above-mentioned condition (1) of the present invention, but preferably has optical properties, heat resistance, chemical resistance, mechanical properties and economical efficiency. The polyester resin may be used in consideration of the above. The polyester-based resin is polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytetramethylene terephthalate (PTT), polyhexylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene-1,2-bis(phenoxy). ) Selected from the group consisting of ethane-4,4'-dicarboxylate, polyethylene isophthalate/terephthalate copolymer, polybutylene terephthalate/isophthalate copolymer, polybutylene terephthalate/decane-dicarboxylate copolymer and the like. It may contain at least one component, preferably polyethylene terephthalate (PET) or modified polyethylene terephthalate, more preferably polyethylene terephthalate (PET). As a non-limiting example of the modified polyethylene terephthalate, in addition to ethylene glycol which is a diol component as a monomer and terephthalic acid as an acidic component, a sulfonated metal salt may be further included. There may be sulfisophthalate sodium salt and the like. Further, an aromatic polycarboxylic acid other than terephthalic acid may be further included as a monomer, and as an example thereof, any one or more of dimethyl terephthalate, isophthalate and dimethyl isophthalate may be included. As a result, the diol component other than ethylene glycol can be further contained as a monomer. Examples of such a diol component may include neopentyl glycol, diethylene glycol, neopentyl glycol, 1,3-propanediol, 1,4-butanediol, 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 in order to further exhibit physical properties such as improved strength, dimensional stability and heat resistance, and more preferably biaxially stretched. The film may be a film, more preferably a film which is biaxially stretched and then heat set at 175 to 225° C., and more preferably a biaxially stretched and heat set polyethylene terephthalate film. sell.

In addition, the thickness of the reliability support layer may be 10 to 600 μm, and more preferably, the decrease in brightness due to the increase in the thickness of the support layer is minimized, and at the same time, the desired reliability is realized. In addition, the thickness may be 60 to 300 μm, more preferably 100 to 200 μm. Through this, it is possible to realize the physical properties of the composite reflective polarizing film, such as desired reliability, while minimizing the decrease in brightness that may occur due to the inclusion of the reliability support layer. If the thickness of the reliability support layer is less than 10 μm, the desired reliability cannot be realized and the appearance of foreign matter may not be covered in the appearance of the reflective polarizing film. If the film does not contain a skin layer, the protective function of the reflective polarizing film may not be performed well. If the thickness of the reliability supporting layer exceeds 600 μm, high reliability can be realized, but there is a problem that the thickness of the thicker reliability supporting layer significantly lowers the brightness. However, the thickness is not limited to the preferable thickness range of the reliability supporting layer, and may be adjusted differently depending on the thickness of the reflective polarizing film used.

Meanwhile, a first primer layer for enhancing adhesion may be further included between the reflective polarizing film 200 and the reliability support layer 300. The first primer layer may be formed by curing by including at least one polymer resin of a photocurable polymer resin or a thermosetting polymer resin. As a specific type of such a polymer resin, any polymer resin that can minimize the luminance reduction due to the primer layer can be used without limitation, and its material is a silicon-based, urethane-based, or silicon-urethane hybrid structure. The polymer resin containing a polymer substance classified into a SU polymer, an acrylic type, an isocyanate type, a polyvinyl alcohol type, a gelatin type, a vinyl type, a latex type, a polyester type, an aqueous polyester type, or the like. A non-limiting example to this 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 may be applied. Examples of the monomer include DPHA (Dipentaerythritol Hexaacrylate), DPPA (Dipentaerythritol Pentaacrylate), TMPTA (trimethyolylateproylate), TMPTMA(Acrylate), and TMPTMA(Acrylate). DPGDA (Dipropylene Glycol Diacrylate), TPGDA (Tripropylene Glycol Diacrylate), Phenoxyethyl acrylate (PEA), Isobornyl methacrylate (IBOA), 2-Hydroxyethyl methacrylate (2-HEMA), and 2-Hydroxyethyl acrylate. One or more monomers selected from HEA) can be applied. More specifically, as a non-limiting example for this, as the monomer, DPAH (5 to 30%), DPPA (5 to 30%), TMTPA (3 to 20), PEA (10 to 50%), IBOA ( 10 to 40%), 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 layers having different thicknesses, and the thickness of the first primer layer may be adjusted to improve the light transmittance, and at the same time, reduce the reflectance. You can The thickness of the first primer layer may be 1 μm to 10 μm. If the thickness of the first primer layer is less than 1 μm, the adhesion between the reflective polarizing film and the reliability support layer may be very weak, and if the thickness of the first primer layer exceeds 10 μm, the first When the primer layer is processed, unevenness and molecular agglomeration may occur.

As described above, the composite reflective polarizing film according to the first embodiment of the present invention has a haze value of 65% or more, preferably 73% or more, as the condition (2) according to the present invention. It may be preferably 85% or more, more preferably 90% or more.

By satisfying the haze value, it is possible to prevent the appearance of various foreign substances and bubbles that may be contained in the film during the manufacturing process, and improve the appearance quality. If the above range is not satisfied, the quality of the appearance deteriorates, and there is a problem in that a separate device or a separate other structure must be added in order to prevent foreign matter from appearing. This is not preferable in slimming the composite reflective polarizing film, and there is a problem that the manufacturing time and manufacturing cost are increased due to the added structure.

Meanwhile, the present invention includes an embodiment in which the light diffusing layer 100, the reflective polarizing film 200, and the reliability support layer 300 are laminated in the different order from the first embodiment according to the present invention. As shown in FIG. 18, the reflective polarizing film 200′, the reliability support layer 300′, and the light diffusing layer 100′ may be sequentially stacked and implemented. The composite reflective polarizing film as shown in FIG. 18 may reduce the brightness to some extent due to the reliability support layer as compared with the composite reflective polarizing film as shown in FIG. 5, but has a similar level of excellent reliability and poor surface appearance. Can be prevented.

Further, as another example, unlike FIG. 5 and FIG. 18, a composite reflective polarizing film may be embodied by laminating a reflective polarizing film, a light diffusing layer, and a reliability supporting layer in this order. When compared with the composite reflective polarizing film of FIG. 5, the reliability supporting layer may reduce the brightness, but has the advantage of being able to prevent the development of a similar level of excellent reliability and a poor surface appearance. is there. However, the light diffusing layer may include a fine pattern, more preferably a prism pattern, in order to improve the optical characteristics that decrease.

As described above, the first embodiment described above is manufactured by the following manufacturing method, but is not limited thereto. Specifically, the manufacturing process includes (1) forming a light diffusion layer on the upper surface of the reflective polarizing film; and (2) forming a reliability support layer on the lower surface of the reflective polarizing film. Thus, the steps (1) and (2) may be performed in any order. Hereinafter, the same description as each of the above-mentioned components will be omitted, and a specific description will be given focusing on the manufacturing method.

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

The reflective polarizing film includes (a) a base material and a plurality of dispersions that are included in the base material and that transmit the first polarized light emitted from the outside and reflect the second polarized light. The plurality of dispersions have a refractive index different from that of the base material in at least one axial direction, and 80% or more of the plurality of dispersions contained in the base material has a vertical cross section in the longitudinal direction. The aspect ratio of the length of the minor axis to the length of the major axis is 1/2 or less, and the dispersion having the aspect ratio of 1/2 or less is included in at least three groups according to the cross-sectional area. , the cross-sectional area of the dispersion of the first group among the groups is 0.2 to 2.0 [mu] m ^2, the cross-sectional area of the dispersion of the second group, the 2.0 .mu.m ² exceeding 5.0 .mu.m ² below There, step cross-sectional area of the dispersion of the third group is a 10.0 [mu] m ² or less from 5.0 .mu.m ² exceeded, dispersions of the first group to third group is to be arranged at random; Can be manufactured.

According to another preferred embodiment of the present invention, the reflective polarizing film manufactured through the step (a) is used as a core layer, and the skin layer integrated with at least one surface of the core layer is used as a step (b). The reflective polarizing film may be manufactured by further including the step of forming.

Hereinafter, the steps of performing both (a) and (b) will be specifically described, but the present invention is not limited thereto. Also, the steps (a) and (b) may be performed through an integrated process described below, not intermittently.

Specifically, first, the base material component, the dispersion component and the skin layer component are supplied to the extrusion section. The base material component and the dispersion component can be individually supplied to independent extrusion sections, in which case the extrusion sections can be composed of two or more. It is also included in the present invention that the polymer is supplied to one extrusion unit including a separate supply path and distribution port so as not to mix. The extrusion unit may be an extruder, which may further include a heating unit or the like so as to convert the supplied polymer in a solid state into a liquid state.

The viscosities of the polymers are designed to be different so that the dispersion components can be arranged inside the base component, and the base component preferably has better flowability than the dispersion component. To Next, while the base material component and the dispersion component pass through the mixing zone and the mesh filter zone, the dispersion component is randomly arranged in the base material through the difference in viscosity.

Next, at least one surface of the manufactured core layer is laminated with the skin layer component transferred in the extrusion section. Preferably the skin layer components are fully overlaid on both sides of the core layer. When skin layers are laminated on both sides, the material and thickness of the skin layers may be the same or different from each other.

Then, the spread is induced by the flow control unit so that the dispersion components contained inside the substrate can be randomly arranged. Specifically, the size of the cross-sectional area and the arrangement of the dispersion component are randomly adjusted by appropriately adjusting the extent of spreading of the substrate through a coat-hanger die that is a kind of flow control unit as shown in FIGS. 19 and 20. can do. Since the substrate on which the skin layers transferred through the flow path in FIG. 19 are superposed spreads left and right by the coat-hanger die, the dispersion component contained therein also spreads laterally.

According to a preferred embodiment of the present invention, cooling and smoothing the spread-induced reflective polarizing film transferred by the flow controller, and stretching the reflective polarizing film that has undergone the smoothing step. Heat-setting the stretched reflective polarizing film.

First, in the step of cooling and smoothing the polarizer transferred by the flow control unit, it is cooled by the method used in the production of ordinary reflective polarizing film to solidify it, and then the cast roll process etc. Through the smoothing step.

Then, a process of stretching the reflective polarizing film that has undergone the smoothing process is performed.

The stretching may be performed through a normal reflective polarizing film stretching process, which may induce a difference in refractive index between the base component and the dispersion component to induce a light modulation phenomenon at an interface. The aspect ratio of the induced first component (dispersion component) is further reduced through stretching. For this reason, the stretching step can preferably be uniaxial stretching or biaxial stretching, and more preferably uniaxial stretching. In the case of uniaxial stretching, the stretching direction may be the lengthwise direction of the first component. The stretch ratio may be 3 to 12 times. On the other hand, a method for changing an isotropic material to be birefringent is generally known. For example, when stretched under an appropriate temperature condition, the dispersion molecules are oriented and the material becomes birefringent. Can be.

Next, the final reflective polarizing film may be manufactured through a step of thermally fixing the stretched reflective polarizing film. The heat setting may be performed by a conventional method, preferably 180 to 200 for 0.1 to 3 minutes through an IR heater.

As described above, the step of forming the light diffusion layer on the upper surface of the reflective polarizing film that can be manufactured by the method described above is performed.

At this time, an adhesive layer may be further formed on the upper surface of the reflective polarizing film in order to facilitate the formation of the light diffusion layer and improve the adhesive strength, appearance, and electroluminescent properties of the light diffusion layer.

Explaining the manufacturing method when the light diffusion layer is a fine pattern, the specific method is not particularly limited in the present invention, preferably a master roll in which the reverse pattern of the fine pattern is engraved or the fine pattern The reverse pattern may be formed on the reflective polarizing film through the pattern forming mold film.

First, in the case of a method using a master roll in which an inverse pattern of the fine pattern is engraved, 1-i) any one selected from the group consisting of prisms, lenticulars, microlenses, triangular pyramids, beads and pyramid patterns A reflective polarizing film is closely transferred to a master roll in which a pattern having an opposite phase with respect to one or more fine patterns is formed on the outer surface, and a polymer resin melted on the pattern surface of the master roll or the reflective polarizing film. 1-ii) applying one or more of light and heat to cure the polymer resin while the polymer resin is pressure-molded on the pattern surface of the master roll, And a step of separating it.

In addition, after the step 1-ii), a step of irradiating UV or heat again to secondarily cure the polymer resin may be further included.

Specifically, FIG. 21 is a schematic view of a fine pattern forming process according to a preferred embodiment of the present invention, and FIG. 22 is a sectional view showing a detailed structure of a molding part of FIG. In FIG. 22, the reflective polarizing film 770 passes through the guide roll 754 while being fed from the start roll 755, and passes through the infrared lamp 751. In this process, the reflective polarizing film 770 is surface-modified by the infrared rays of the infrared lamp, and the adhesiveness with the light diffusion layer 771 is improved. When the reflective polarizing film 770 separated from the start roll 755 is drawn into the master roll 705 via the pattern guide roll 764, the pattern surface of the master roll 705 is injected from the injection part 742 to be a material for the light diffusion layer 771. Molecules are 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 by primary UV light emitted from a primary UV curing device 752 disposed below the master roll 705. At this time, the temperature around the curing device 752 is 20 to 30° C., the temperature of heat generated while the resin is curing is 40 to 80° C., and the glass transition temperature (Tg: high) of the resin is high. In the molecular resin, the temperature may be around a temperature at which the resin changes its characteristics like a soft rubber before undergoing a complete phase change from solid to liquid. The light diffusion layer 771 in which the pattern shape on the surface of the master roll is completely transferred in the glass transition state further passes through the pattern guide roll 764 and exits, and the reflection polarization film 770 and the light diffusion layer 771 are combined to form the reflection polarization film 772. And is passed through a guide roll 754 and wound on a finish roll 756.

As shown in FIG. 20, a cross section of the reflective polarizing film 772 having a turn formed by irradiating UV twice is a surface of a shape opposite to the cross section of the master roll 705. If it is an engraved surface, the turn-formed reflective polarizing film (772) becomes an embossed surface of embossing.

Next, in the case of a method using a pattern forming mold film in which a reverse pattern of a fine pattern is formed, the material of the pattern forming mold film is transparent and flexible, and has a predetermined tensile strength and durability. A film having the same can be used, and a PET film is preferably used.

In this case, according to a preferred embodiment of the present invention, the step (1) is selected from the group consisting of 1-1) reflective polarizing film and prism, lenticular, microlens, triangular pyramid, beads and pyramid pattern. Transferring a pattern-forming mold film having a pattern opposite in phase to any one or more of the formed fine patterns formed on one surface; 1-2) an upper surface of the reflective polarizing film and the pattern formation; And forming a pattern by injecting a fluid material between the closely attached reflective polarizing film and the pattern forming mold film. Filling the empty space between the two films; 1-4) curing the filled material and separating the patterning mold film.

Also, between the steps 1-3) and 1-4), pressure is applied to the reflective polarizing film and the pattern-forming mold film, which are in close contact with each other, so that the material is vacant between the two films formed by the pattern. The method may further include uniformly filling the space. In addition, the step 1-4) may include applying at least one of heat and light to the material filled in the empty space between the two films formed by the pattern.

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

First, the reflective polarizing film 810 wound on the first roll 820 is transported by the guide rolls 830a to 830c. At this time, the molding mold 842 of the pattern molding part 840 is also in a state of being transferred/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 meshes with the guide rolls 830c and 830d, the reflective polarizing film 810 meshes with the molding mold 842 while being guided by the guide roll 830c. Here, the guide roll 830c performs a gap adjusting function of adjusting the coating liquid applied to the reflective polarizing film 810, that is, the thickness of the pattern of the light diffusion layer in which the light diffusion layer is engraved with resin. More specifically, if the guide roll 830c is in close contact with the master roll 844, the pattern of the light diffusion layer can be formed thinner. On the contrary, when the guide roll 830c is further separated from the master roll, the pattern of the light diffusion layer can be changed. It can be formed thicker. The pattern thickness of the light diffusion layer can be adjusted by the viscosity of the coating liquid, the patterning speed, the tension of the reflective polarizing film, and the like, in addition to the distance between the guide roll 830c and the master roll 844.

On the other hand, the coating liquid is injected by the coating liquid injection means 860 at a point where the reflective polarizing film 810 is engaged with the guide roll 830c and the master roll 844, and the coating liquid is pushed between the patterns of the molding mold 842 to be filled and guided. The pressure is applied between the roll 830c and the master roll 844 to uniformly distribute the pattern. The coating liquid distributed between the patterns is cured by heat and/or UV emitted from the curing means 870. The reflective polarizing film on which the pattern-formed coating liquid is cured and applied is separated from the molding mold 842 while being guided by the guide roll 830d, and the reflective polarizing film 812 having the pattern is transferred by the guide roll 830e. And is wound on the second roll 850. Here, the guide roll 830d performs a peeling function of separating the reflective polarizing film 812 coated with the coating liquid, that is, the light diffusion layer from the molding mold 842.

The reflective polarizing film 810 and the reflective polarizing film 812 having the light diffusing layer formed on one surface are connected to each other, and the names are classified for convenience of description. That is, the reflective polarizing film 810 means a state before the light diffusing layer is formed, and the reflective polarizing film 812 having the light diffusing layer passes through the pattern molding part 840 and is patterned into a coating liquid. Is applied to the reflective polarizing film to be completed. Further, FIG. 23 shows only a part of the pattern layer formed on the reflective polarizing film 812 on which the light diffusion layer is formed, and actually, on the reflective polarizing film wound on the second roll 850. Also becomes a state in which the light diffusion layer is formed.

24 is a schematic view of a fine pattern forming process according to another preferred embodiment of the present invention. Specifically, this is an example in which the molding mold 942 is formed in a roll type so as to be as long as the length of the reflective polarizing film 910, so that the reflective polarizing film 912 having the light diffusion layer is seamless.

Also in the second embodiment of the optical member manufacturing apparatus according to the present invention, the first roll 920 around which the reflective polarizing film 910 is wound and the second roll 950 around which the reflective polarizing film 912 having the light diffusing layer are wound are provided on both sides. Guide rolls 930a to 930f for transporting the reflective polarizing film and the reflective polarizing film on which the light diffusion layer is formed are provided between the first roll 920 and the second roll 950. In addition, the master roll 946 of the pattern molding part 940 comes into close contact between the guide roll 930c and the guide roll 930d in order to apply the coating liquid having the pattern formed on the reflective polarizing film 910. Here, it is needless to say that the number and positions of the guide rolls 930a to 930f can be changed depending on the implementation state. The pattern molding unit 940 includes a film-shaped molding mold 942 in which the pattern shape is embodied, a third roll 944 around which the molding mold is wound, and a coating liquid to be injected is pressed onto the molding mold to follow the pattern of the molding mold. A master roll 946 for pattern-forming the coating liquid and applying it to the reflective polarizing film 910, pattern guide rolls 947a to 947d for transferring the molding mold, and a fourth roll 948 around which the transferred molding mold is wound. Of course, the number and positions of the pattern guide rolls 947a to 947d can be changed depending on the implementation state.

Unlike the embodiment of FIG. 23, the molding mold 942 has a pattern formed of the coating liquid on the reflective polarizing film 910 while being wound around the third roll 944 and being transferred by the master roll 946 and the guide rolls 947a to 947d. Is molded and then wound on a fourth roll 948. At this time, the molding mold 942 is preferably formed to have the same length as the reflective polarizing film 910, and the reflective polarizing film 912 on which the light diffusion layer including the pattern is formed is free from pattern defects and pattern disconnection due to seams. A pattern is formed uniformly over the entire area. In FIG. 24, only a part of the pattern in which the pattern is embodied in the molding mold is shown, but in an actual implementation, the pattern is embodied over the entire molding mold.

A coating liquid injecting means 960 for injecting a coating liquid is provided at a position where the reflective polarizing film 910 is drawn into the pattern molding part 940, that is, a position where the guide roll 930c and the master roll 946 are in close contact with each other. A curing unit 970 for irradiating heat or UV to cure the coating liquid is provided at a position where the molding mold 942 closely moves.

On the other hand, the method for forming the bead coating layer on the reflective polarizing film is not particularly limited, but the reflective polarizing film can be coated with the composition for forming a bead coating layer by an ordinary method. Preferably, the coating method may be formed by any one of comma coating, reverse coating, clavier coating, blade coating, silk screen coating and slot die head coating. At this time, the bead coat layer can be formed so that the beads are contained in the resin layer by adjusting the diameter of the beads contained in the composition and the thickness depending on the amount of the composition applied, or It is also possible to form a bead coat layer in which only a part is embedded. The coated composition may be cured by light and/or heat depending on the type of resin included according to the usual conditions, and the light may be preferably UV.

Next, as the step (2) according to the present invention, a step of forming a reliability support layer on the lower surface of the reflective polarizing film is performed.

The step (2) comprises: 2-1) forming a first primer layer on the upper surface of the reliability supporting layer to enhance the adhesion between the reflective polarizing film and the reliability supporting layer; And laminating the first primer layer and the lower surface of the reflective polarizing film so that they are in contact with each other.

As a method for forming the first primer layer on the reliability support layer, a known method can be selected. In the present invention, the method is not particularly limited, and a comma coating, a reverse coating, It may be formed by any one of a clavier coat, a blade coat, a silk screen coat and a slot die head coat.

Then, as a step 2-2), a step of laminating the formed first primer layer so that the lower surface of the reflective polarizing film is in contact with the first primer layer is performed. At this time, the first primer layer may be cured by being superposed on the reflective polarizing film in a semi-cured state, or may be cured after being superposed on the reflective polarizing film as it is in a coated state. A specific method for the curing is determined depending on the kind of the polymer resin used as the first primer layer, and preferably, the curing can be performed by applying heat and/or light. A method can be adopted, and the present invention is not particularly limited.

Meanwhile, the steps (1) and (2) according to the method for manufacturing the composite reflective polarizing film according to the preferred embodiment of the present invention may be performed in any order, and may be manufactured in a different order depending on manufacturing equipment. You can To explain this in detail, FIG. 25 is a cross-sectional view of a reflective polarizing film and a reliability support layer that are stacked according to a preferred embodiment of the present invention, in which the first primer is formed on the lower surface of the reflective polarizing film 200. The reliability support layer 300 on which the layer 400 is formed is superposed such that the first primer layer 400 abuts on the lower surface of the reflective polarizing film 200, and then the superposed reflective polarizing film/first primer layer/reliability 22 may be introduced into the start roll 755 of FIG. 22 or the first roll 820 of FIG. 23 to form a light diffusion layer on the upper surface of the reflective polarizing film.

Next, a composite reflective polarizing film according to a second embodiment of the present invention will be described. Referring to FIG. 26, the composite reflective polarizing film 1000 includes a light diffusion layer 100 formed on an upper surface of the reflective polarizing film 200, a reliability support layer 300 formed on a lower surface of the reflective polarizing film 200, and the reliability. A first primer layer 400 for enhancing adhesion between the reflective polarizing film 200 and the reliability support layer 300 and the reliability support layer 300, including a light collecting layer 600 formed on a lower surface of the support layer. A second primer layer 500 may be further included to enhance the adhesion of the light collecting layer 600.

Of the components of the second embodiment described above, the description of the same parts as those of the first embodiment will be omitted, and the differences and the components not provided in the first embodiment will be described.

The reliability support layer 300 may have a thickness of 10 to 300 μm according to a light-collecting layer 600, which will be described later, and more preferably minimizes a decrease in brightness and more easily realizes a desired reliability. Therefore, the thickness may be 30 to 200 μm, and more preferably 80 to 150 μm. If the thickness of the reliability support layer is less than 10 μm, the desired reliability may not be realized, and the desired reliability may be realized even if the reliability is complemented through a light collecting layer described later. In order to achieve this, a thick light-collecting layer must be used, and with this, the brightness can be significantly reduced, which may not cover the appearance of foreign matter in the appearance of the reflective polarizing film. In addition, if the reliability support layer has a thickness of more than 300 μm, a high reliability can be realized, but the brightness can be significantly reduced, and a product such as a backlight unit including a composite reflective polarizing film. In consideration of the above, the composite reflective polarizing film has only a limited thickness. There is a problem that the effect of layers is not realized. However, it is not limited to the preferable thickness range of the reliability supporting layer described above, and is adjusted differently depending on the thickness of the reflective polarizing film used and the range of the thickness of the supporting portion in the light collecting layer described later. Can be done.

The light collecting layer 600 formed on the lower surface of the reliability supporting layer 300 with the composite reflective polarizing film will be described.

Specifically, FIG. 27 is a perspective view of a light collecting layer included in a preferred embodiment of the present invention, wherein the light collecting layer 600 is formed on a support 620 and one surface of the support 620. A prism pattern part 610 may be included, and the prism pattern part 610 may be coupled to a lower surface of a reliability support layer (not shown) or a lower surface of a second primer layer (not shown). ..

The support part 620 plays a role of supporting the prism pattern part 610 included in the light collecting layer 600, and also has a function of further improving the reliability of the composite reflective polarizing film. That is, as the light collecting layer for the light collecting function is integrated with the composite reflective polarizing film, the light collecting layer can simultaneously perform not only the light collecting function but also the function of supporting the composite reflective polarizing film, Even if the reliability support layer is realized with a thin thickness due to the function of the light collecting layer, the composite reflective polarizing film has no problem in maintaining reliability as a whole, so all physical properties should be satisfied at the same time. Also, it can be very advantageous for thinning the optical film included in the backlight unit.

The supporting part 620 can be used without limitation if it is a material capable of supporting various structured patterns included for improving optical physical properties in the art and at the same time, a material that does not impede light transmission. .. Examples of this include polycarbonates, polysulfones, polyacrylates, polystyrenes, polyvinyl chlorides, polyvinyl alcohols, and polyvinyl alcohols. The material may include, but is not limited to, a poly norbornene-based material and a polyester (poly ester)-based material. However, in consideration of remarkably excellent supporting ability, product cost, heat resistance, and light transmittance, the supporting portion 620 preferably contains a polyester-based material, and more preferably the polyester-based material is polyethylene terephthalate ( PET). Also, the polyethylene terephthalate film may be a film stretched in at least one axial direction.

The thickness of the supporting part 620 is the height of the prism pattern part formed on the supporting part, the total thickness of the composite reflective polarizing film, the thickness of the reliability supporting layer, and the desired physical properties such as the minimum brightness reduction. Since it can be designed differently depending on the situation, it is not particularly limited. For the remarkable improvement in reliability of the composite reflective polarizing film due to the minimum supporting function for the light collecting layer and the reliability of the supporting layer It preferably has a thickness of 10 to 300 μm, more preferably 60 to 200 μm, and even more preferably 80 to 200 μm. If the thickness of the supporting portion is less than 10 μm, the supporting function of the prism pattern portion may not be performed smoothly, and the reliability of the composite reflective polarizing film may not be improved sufficiently. Further, if the thickness exceeds 300 μm, it may be advantageous for the reliability of the target composite reflective polarizing film to be exhibited, but there may be a problem that the optical characteristics such as brightness are significantly reduced.

On the other hand, from the aspect of reliability due to the reliability support layer and the support part, the support part may have a linear expansion coefficient of 4 to 35 μm/m° C. in the temperature range of 70 to 80° C. due to the phase rising effect. It is possible, and more preferably, the linear expansion coefficient can satisfy 10 to 25 μm/m·° C. in the temperature range of 70 to 80° C. By satisfying this, it is possible to prevent the reflective polarizing film from being wrinkled 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/or a product to which this is applied. Accordingly, the excellent composite reflective polarizing film can be made to have excellent reliability. Specifically, when the linear expansion coefficient exceeds 35 μm/m·° C. in the temperature range of 70 to 80° C., such a problem may be further deepened, so that it is not used as a composite reflective polarizing film in a backlight unit. However, when the coefficient of linear expansion is less than 4 μm/m·° C., it is excellent in terms of reliability, but the reliability supporting layer having such thermal characteristics is manufactured in a film shape in terms of material. Or the optical properties can be significantly deteriorated. Usually, in order to manufacture a material used for an optical film with a linear expansion coefficient of less than 4 μm/m·° C., a draw ratio is extremely high. There is a problem in that optical characteristics such as brightness are extremely deteriorated by increasing the thickness or increasing the thickness of itself.

Next, the prism pattern portion 610 formed on one surface of the support portion 620 will be described.

The prism pattern part 610 is for enhancing the light collecting function under the composite reflective polarizing film, and is formed of a plurality of prisms 611 and 612 formed on the supporting part 620 as shown in FIG. obtain. At this time, each prism 611 includes prism surfaces that are inclined on both sides with respect to the top ridge 611a. The apex angles of the prisms 611, 612 may be in the range of 45° to 135°, 60° to 130°, or 85° to 105°. The pitch of the prisms 611 may be about 20 to 100 μm, and the height may be about 10 to 60 μm. The prism 611 may be continuously formed from one side of the support 620 to the other side. Adjacent prisms 611, 612) may be adjacent to each other, but may be partially separated. Here, that the prisms 611 and 612 are adjacent to each other means that the bottom surfaces of the prisms are adjacent to each other.

In addition, the prisms 611 and 612 may be formed on the entire surface of the support part 620. When the support 620 has a rectangular shape in a plan view, the first direction X1 that is the extension direction of the prisms 611 and 612 may be parallel to the long side or the short side of the support 620. In some other examples, the first direction X1 may have an acute angle of intersection with the long side and/or the short side of the support 620. For example, the intersection angle may be in the range of ±5 to ±30°.

The prism pattern portion 610 includes a silicon-based, urethane-based, SU polymer having a silicon-urethane hybrid structure, an acrylic-based, an isocyanate-based, a polyvinyl alcohol-based, a gelatin-based, a vinyl-based, a latex-based, a polyester-based, a water-based polyester-based, or the like. It may be formed of a polymer resin, and preferably may be formed by curing with heat and/or light.

Meanwhile, according to an exemplary embodiment of the present invention, a second primer layer 500 may be further included between the reliability support layer and the light collecting layer to enhance adhesion.

The second primer layer 500 may be formed by curing by including at least one polymer resin of a photo-curable polymer resin or a thermosetting polymer resin. The material of the first primer layer may be used in the first embodiment. In addition, the second primer layer may be formed thinner than layers having different thicknesses, and the thickness of the second primer layer may be adjusted to improve light transmittance and reduce reflectance. can do. The thickness of the second primer layer may be 3 μm to 10 μm. If the thickness of the second primer layer is less than 3 μm, the adhesive force between the reliability support layer and the light collecting layer may be very weak. If the thickness of the second primer layer exceeds 10 μm, the second When the primer layer is processed, unevenness and molecular agglomeration may occur.

Meanwhile, the composite reflective polarizing film according to the second embodiment of the present invention may be embodied such that the value of Equation 1 below satisfies 0.3 to 2.0.

As can be seen from FIG. 26, the composite reflective polarizing film according to a preferred embodiment of the present invention includes a reflective polarizing film 200 and a reliability support layer 300 for maintaining reliability of the reflective polarizing film. The light collecting layer 600 is provided in order to enhance the optical properties and improve the optical properties, and the multi-functions are integrally combined. The light-collecting layer 600 includes a support portion 620 that supports the light-collecting layer. However, when the reliability support layer 300 provided to secure high reliability becomes thick, small wrinkles or bends are formed. However, there is a problem in that the optical properties such as brightness are significantly lowered, but the thinning of the composite reflective polarizing film is very unfavorable.

As a result, the support function of the reliability support layer provided to maintain the reliability of the composite reflective polarizing film is shared by the support portion 620 of the light collection layer 600 provided to enhance the light collecting power. The reliability of the composite reflective polarizing film can be achieved without increasing the reliability of the support layer 300, and at the same time, the deterioration of optical properties such as brightness that may occur due to the provision of the support layer can be minimized. .. Accordingly, in the composite reflective polarizing film according to a preferred embodiment of the present invention, the value of the following formula 1 according to the present invention should satisfy 0.3 to 2.0, preferably the value of the formula 1 is 0. It can be 6 to 1.6. Through this, the reliability of the composite reflective polarizing film can be remarkably improved and optical properties such as brightness can be exhibited at the same time. While maintaining the excellent physical properties, the composite reflective polarizing film can be made thin and slim. Highly preferred for mold displays.

If the value of Equation 1 according to the present invention is less than 0.3, the reflective polarizing film is distorted at high temperature, and wrinkles and/or bending and/or the composite reflective polarizing film is heated due to the difference in linear expansion coefficient between the reflective polarizing film and the reliability support layer. Therefore, it may be difficult to prevent appearance change such as bending as a whole, reliability may be significantly reduced, and the wrinkles and bending may induce the unevenness phenomenon of the panel. In addition, since the support portion becomes thin and the support function for the light collecting layer is reduced, it may be difficult to exhibit the original physical properties of the light collecting layer. Can be Further, if the value of the mathematical formula 1 exceeds 2.0, the optical properties such as brightness are significantly deteriorated, and the desired physical properties cannot be obtained, which is very preferable for thinning the composite reflective polarizing film. Absent.

On the other hand, even if the total thickness of the support portions 620 of the reliability support layer 300 and the light collection layer 600 satisfies the value of Equation 1 according to the present invention, the thickness of any one of the two layers is relatively large. If the thickness of the reflective polarizing film is too thick, it may not be possible to prevent changes in the appearance of wrinkles or bending of the reflective polarizing film, or there may be a problem of reduced brightness. Therefore, the composite reflective polarizing film according to a preferred embodiment of the present invention is represented by the following formula 2. The value can satisfy 0.25 to 4.0, more preferably 0.6 to 2.5, and more preferably 0.9 to 2.0.

If the value of Equation 2 is less than 0.25, the reliability supporting layer becomes relatively thin, and it may be difficult to prevent appearance changes such as wrinkles and bending that may occur in the reflective polarizing film. It may be difficult to prevent damage such as the polarizing film easily bursting. In addition, if the value of Expression 2 exceeds 4, the reliability supporting layer becomes too thick, and the optical properties such as brightness are significantly deteriorated.

The composite reflective polarizing film according to the second embodiment of the present invention includes (a) forming a light diffusing layer on the upper surface of the reflective polarizing film; and (b) forming a reliability support layer on the lower surface of the reflective polarizing film. And (c) forming a light collecting layer on the lower surface of the reliability supporting layer.

Since the steps (a) and (b) are the same as the steps (1) and (2) according to the first embodiment of the present invention, the detailed description thereof will be omitted.

In the second embodiment of the present invention, step (c) is a step of forming a light collecting layer on the lower surface of the reliability support layer. Hereinafter, step (c) will be described by taking the case where the light collecting portion of the light collecting layer has a prism pattern as an example.

The specific method of forming the prism pattern on the upper surface of the support portion is not particularly limited in the present invention, but preferably a master roll in which a reverse pattern of the prism pattern is engraved or a reverse pattern of the prism pattern is formed. The pattern forming mold film may be formed on the support.

First, in the case of a method using a master roll in which an inverse pattern of the prism pattern is engraved, according to a preferred embodiment of the present invention, a master having a pattern opposite to the prism pattern formed on the outer surface is formed. A step of closely transferring the support portion to the roll and applying a molten polymer resin to the pattern surface of the master roll or the support portion; while the polymer resin is pressure-molded on the pattern surface of the master roll Curing the polymer resin by applying at least one of light and heat and separating the polymer resin.

28 is a schematic view of a process of forming a fine pattern of a light collecting layer according to a preferred embodiment of the present invention. In FIG. 28, the supporting unit 1070 is extended from the start roll 1055 while being guided by the guide roll 1054. Through the infrared lamp 1051. In this process, the supporting portion 1070 is surface-modified by the infrared rays of the infrared lamp, and the adhesiveness with the prism pattern portion 1071 is improved. When the support portion 1070 separated from the start roll 755 is pulled into the master roll 1005 via the pattern guide roll 1064, the polymer that is the material of the prism pattern portion 1071 is formed on the pattern surface of the master roll 705 from the injection portion 1042. Is applied and bonded to the support portion 1070. In this process, the resin is a resin melted at room temperature, and can be primary cured by primary UV light emitted from a primary UV curing device 1052 arranged below the master roll 1005. At this time, the temperature around the curing device 1052 is 20 to 30° C., the enthusiasm temperature generated by curing the resin is 40 to 80° C., and the glass transition temperature (Tg: polymer) of the resin is Before the resin undergoes a complete phase change from a solid to a liquid, it may be at a temperature near the characteristic of changing like soft rubber). The prism pattern portion 1071 in which the pattern shape on the surface of the master roll is completely transferred in the glass transition state is further passed through the pattern guide roll 1064 and exits to the light collecting layer 1072 in which the support portion 1070 and the prism pattern portion 1071 are combined. After being formed, it passes through the guide roll 1054 and is wound on the finish roll 1056.

As shown in FIG. 28, the cross-section of the light-collecting layer 1072 having a turn formed by irradiating UV twice is a surface of a shape that is opposite to the cross-section of the master roll 1005. If the surface is an engraved surface, the turn-formed reflective polarizing film 772 is an embossed surface that is embossed.

Next, in the case of a method using a pattern forming mold film in which a reverse pattern of a prism pattern is formed, the material of the pattern forming mold film is transparent, flexible, and has a predetermined tensile strength and durability. Can be used, and it is preferable to use a PET film. In this case, according to a preferred embodiment of the present invention, transferring a pattern-forming mold film having a pattern opposite to the supporting part and the prism pattern formed on one surface; and an upper surface of the supporting part. And a step of bringing the pattern-formed one surface of the pattern-forming mold film into close contact with each other; injecting a fluid material between the closely-contacted support portion and the pattern-forming mold film to form two patterns formed by the pattern. Filling the empty spaces between the substrates; curing the filled material to separate the patterning mold film. Preferably, the method may further include the step of applying a pressure to the intimate support and the pattern forming mold film to uniformly fill the empty space between the two films formed by the pattern. Further, preferably, the curing may be performed by applying one or more of heat and light to the material filled in the empty space between the two films formed by the pattern.

FIG. 29 is a schematic view of a process of forming a fine pattern of a light collecting layer according to another preferred embodiment of the present invention. First, the support portion 1110 wound around the first roll 1120 has guide rolls 1130a to 1130c. Are transferred by. At this time, the molding mold 1142 of the pattern molding part 1140 is also in a state of being transported/rotated while being wound around the master roll 1144 and the pattern guide rolls 1146a and 1146b. At this time, since the master roll 1144 meshes with the guide rolls 1130c and 1130d, the support portion 1110 is guided by the guide roll 1130c and meshes with the molding mold 1142. Here, the guide roll 1130c performs a gap adjusting function of adjusting the thickness of the coating liquid applied to the supporting portion 1110, that is, the pattern thickness of the prism pattern portion in which the prism pattern portion is resin-engraved. More specifically, if the guide roll 1130c is in close contact with the master roll 1144, the pattern of the prism pattern portion can be formed thinner. On the contrary, when the guide roll 1130c is slightly separated from the master roll, the prism pattern portion The pattern can be formed thicker. The pattern thickness of the prism pattern portion can be adjusted by the viscosity of the coating liquid, the patterning speed, the tension of the reflective polarizing film, and the like, in addition to the distance between the guide roll 1130c and the master roll 1144.

On the other hand, at a point where the support portion 1110 meshes with the guide roll 1130c and the master roll 1144, the coating liquid is injected by the coating liquid injecting means 1160 and is pushed into the space between the patterns of the molding mold 1142 to be filled. The pressure is applied between the roll 1130c and the master roll 1144 to uniformly distribute the pattern. The coating liquid distributed between the patterns is cured by the heat and/or UV emitted from the curing unit 1170. The reflective polarizing film on which the pattern-formed coating liquid is cured and applied is separated from the forming mold 1142 while being guided by the guide roll 1130d, and the light-collecting layer 1112 on which the prism pattern portion is formed on the support portion 1110 is formed. Then, it is transported by the guide roll 1130e and wound on the second roll 1150. Here, the guide roll 1130d performs a peeling function of separating the supporting portion 1110 coated with the coating liquid, that is, the prism pattern portion from the molding mold 1042.

The support part 1110 and the support part 1110 on which the prism pattern part is formed on one surface are connected to each other, and their names are classified for convenience of description. That is, the support part 1110 means a state before the prism pattern part is formed, and the support part 1110 having the prism pattern part has the pattern formed coating liquid while passing through the pattern molding part 1040. It means a state in which it is applied to 1110 and completed. Further, FIG. 28 shows only a part of the pattern formed on the supporting portion 1110 on which the prism pattern portion is formed, and actually, also on the supporting portion wound on the second roll 1150). The prism pattern portion is formed.

The step (c) is a step of stacking the light collecting layer manufactured through the manufacturing process as shown in FIG. 28 or 29 on the lower surface of the reliability support layer, specifically, c-1). Forming a second primer layer on the lower surface of the reliability support layer to enhance the adhesion between the reliability support layer and the light collection layer; c-2) the second primer layer and one surface of the light collection layer Abuttingly overlapping.

As a method of forming the second primer layer below the reliability supporting layer in the step c-1), a known method can be selected. In the present invention, this is not particularly limited, and a comma coat ( coma coating), reverse coat, clavier coat, blade coat, silk screen coat, slot die head coat and the like.

Next, in step c-2), the second primer layer may be superposed on the formed second primer layer so that one surface of the light collecting layer, more preferably, the prism pattern portions of the light collecting layer are in contact with each other. At this time, the second primer layer may be cured in a semi-cured state by being superposed on the light-collecting layer, or may be cured after being superposed on the reflective polarizing film as it is. A specific method for the curing is determined according to the kind of the polymer resin used as the second primer layer, and preferably, the curing can be performed by heat and/or light. The above method can be adopted, and the present invention is not particularly limited.

In step c-2), the second primer layer is overlapped with the prism pattern portion of the light collecting layer so as to be in contact with each other, but the second primer layer may be added in order to improve optical characteristics and bond strength. The reverse phase intaglio may be engraved on all or part of the prism pattern. In this case, the degree of engraving may be engraved so as to correspond to a reverse phase of a part or all of the prism peak portion with reference to the cross section of one prism. When the crests of the prism pattern and the second primer layer having the intaglio pattern corresponding to the crests are aligned and bonded to each other, more improved optical characteristics and bonding strength can be exhibited.

At this time, a portion of the second primer layer where the reverse phase intaglio is not engraved can form a constant inclined surface with the supporting portion of the light collecting layer as a reference. An inclination angle of about 1 to 4.5 can be formed with respect to the surface, and in this case, as the incident angle can be further increased due to the obtuse pattern at the interface of the second primer layer, more light is refracted. Therefore, there is an advantage that more light can be collected in the upper direction and the brightness can be improved in general.

In the prism pattern of the second primer layer and the light collecting layer, the space between the upper surface of the support portion of the light collecting layer and the valleys of the prism pattern formed on the upper surface may be combined without a gap, or A space may be formed between the upper surface of the support of the light collecting layer and the valleys of the prism pattern formed on the upper surface, and the space may be filled with a vacuum or an air layer.

Meanwhile, the method of manufacturing the composite reflective polarizing film according to the second embodiment of the present invention may be manufactured by performing the steps (a) to (c) in any order.

This will be described in detail. The reliability support layer 300 having the first primer layer 400 formed on the lower surface of the reflective polarizing film 200 is arranged so that the first primer layer 400 contacts the lower surface of the reflective polarizing film 200. After first performing the step (b) of superimposing, the reflective polarizing film/first primer layer/reliable support layer, which is superposed for performing the step (a), is placed on the start roll 755 of FIG. 21 or the first layer of FIG. The light diffusing layer may be formed on the upper surface of the reflective polarizing film by being placed in the roll 820, and then step (c) may be performed.

In addition, after performing the step (b) of stacking the reflective polarizing film 200 and the reliability support layer 400, the step (c) of stacking the light condensing layer 600 on the lower surface of the reliability support layer 400 is performed to manufacture ( After performing the steps (b) to (c)) or superimposing the light collecting layer 600 on the lower surface of the reliability support layer 400 (c), the reflective polarizing film 200 and the reliability support layer 400 are removed. The laminated reflective polarizing film/reliable support layer/light-collecting layer is shown by being manufactured ((sequence (c) to (b)) by performing the superimposing (b) step. When the reflective polarizing film/reliable support layer/light collecting layer is put on the start roll 755 of FIG. 21 or the first roll 820 of FIG. 23 to form the light diffusing layer on the upper surface of the reflective polarizing film, Composite reflective polarizing films can be produced that include up to layers.

As described above, the steps (a) to (c) are performed regardless of the order, and the present invention does not particularly limit any particular order.

The composite reflective polarizing film manufactured according to the second exemplary embodiment includes the reliability support layer 300 for maintaining the reliability of the reflective polarizing film, and enhances light collection to exhibit improved optical properties. For this purpose, the light collecting layer 600 is provided, and the light collecting layer 600 is provided with a support portion 620 that performs a function of supporting the light collecting layer. However, the thickness of the reliability support layer 300 provided to ensure high reliability is provided. When the thickness becomes thicker, the change in appearance of small wrinkles and bending is reduced, but the composite reflective polarizing film due to the difference in the linear expansion coefficient between the reflective polarizing film and the reliability supporting layer is bent like a bimetal. Can occur frequently. In addition, as the thickness of the reliability support layer increases, there may be a problem that optical properties such as brightness deteriorate. Thereby, the reliability support layer 300 does not become thick, and the support function of the reliability support layer for maintaining the reliability of the composite reflective polarizing film supports the light collection layer 600 provided to enhance the light collecting power. Since the supporting portion 620 for dividing the composite reflective polarizing film divides it, it is possible to prevent a warp phenomenon in which the composite reflective polarizing film bends as a whole, and to reduce the deterioration of optical physical properties such as brightness that may occur due to the provision of the supporting layer. The target physical properties of the present invention, such as the minimization, can be realized.

Meanwhile, the composite reflective polarizing film according to the third embodiment of the present invention is a composite reflective polarizing film including a reflective polarizing film in which a polymer is dispersed inside a substrate, wherein the composite reflective polarizing film is formed on an upper surface of the reflective polarizing film. A light diffusing layer formed; a reliability supporting layer formed on a lower surface of the reflective polarizing film; a multi-layer formed under the reliability supporting layer for guiding and condensing light emitted from a light source And a functional layer, and is implemented so as to satisfy the following condition (1) and condition (2).

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

Hereinafter, differences from the above-described first and second embodiments will be mainly described.

The thickness of the reliability supporting layer may be 10 to 300 μm, and more preferably, the thickness is required to minimize a decrease in brightness due to an increase in the thickness of the supporting layer, and at the same time, achieve a desired reliability. May be 60-220 μm, more preferably 80-200 μm in thickness. Through this, it is possible to realize the physical properties of the composite reflective polarizing film, such as desired reliability, while minimizing the decrease in brightness that may occur due to the inclusion of the reliability support layer. If the thickness of the reliability support layer is less than 10 μm, the desired reliability may not be achieved only by the light guide layer of the multi-function layer described below, and the multi-function may be improved to improve the reliability. Even if the thickness of the light guide layer is increased, the reflective polarizing film may change in appearance such as wrinkles and bends. In addition, the multi-functional layer including the light guide layer having a large thickness can significantly reduce optical properties such as brightness. Also, if the thickness of the reliability supporting layer exceeds 300 μm, the brightness may be significantly reduced, and the thickness of the reliability supporting layer becomes thicker, which is not very preferable for thinning the composite reflective polarizing film. There is a problem that the use of the backlight unit including the polarizing film or the display unit including such a unit may be restricted in view of the trend toward slimness. In addition, there is a problem in that the thickness of the multi-functional layer, which will be described later, decreases due to the increase in the thickness of the reliability supporting layer, so that the intended effect of the multi-functional layer cannot be realized.

Next, the multi-functional layer may include a light guide layer and a fine pattern layer including a prism pattern formed on one surface of the light guide layer. At this time, since the fine pattern layer is the same as the fine pattern layer of the light collecting layer in the second embodiment, a detailed description thereof will be omitted.

The light guide layer plays a role of guiding the light emitted from the light source, and at the same time, a role of supporting the fine pattern layer included in the multi-functional layer, and a role of the reliability support layer. In charge of the function of further improving the reliability of the composite reflective polarizing film. Generally, in order to improve the light focusing function of the optical film included in the backlight unit, a fine pattern layer, which will be described later, must be included. In this case, the fine pattern layer is the same as the second embodiment described above. Similarly, it is common to provide a separate support layer for supporting the same. However, the multi-functional layer included in the present invention can support the fine pattern layer through the light guide layer without a separate support layer for supporting the fine pattern layer, and does not include a separate support layer. It may be possible to prevent a reduction in optical characteristics such as brightness, and at the same time, it may be further advantageous to reduce the thickness of the optical film included in the backlight unit. Furthermore, when a heat-resistant material is used for the light guide layer, the light guide layer can partially play the role of the reliability support layer from the aspect of reliability, which reduces the thickness of the reliability support layer. It is possible to realize all the desired physical properties, and at the same time, it is possible to make the optical film thinner, which is very preferable.

The material of the light guide layer can be used without limitation if it is a material of the light guide layer commonly used in the art, and preferred examples thereof include polycarbonate, polysulfone, and polyacrylate. Polyacrylate type, polystyrene type, polyvinyl chloride type, polyvinyl alcohol type, polynorbornene type, polyester (polyester) type 1 or 2 type substances. The above can be included.

However, in the case of a polysulfone or polyacrylic film among the above-mentioned materials, it is excellent in optical characteristics, but it is not preferable in improving the reliability of the composite reflective polarizing film because of its poor heat resistance. Since the material is very solid, it easily breaks, and in the manufacturing process, the composite reflective polarizing film cannot be compounded through a continuous manufacturing process, and each layer is individually cut onto the light guide layer. Since they have to be laminated, the production process is complicated and the productivity may be poor.

Accordingly, according to a preferred embodiment of the present invention, it is possible to wind the optical film around the roller due to its outstanding support ability for the fine pattern layer, product cost, heat resistance, light guiding property, and manufacturing process. When considering all flexibility, it is preferable to include a polycarbonate system. Through this, the other layers can be continuously compounded without cutting the light guide layer individually, and the film can be wound on the roller in the compounding process, which has the advantage of significantly increasing productivity. is there.

The thickness of the light guide layer is the minimum thickness required to maintain the function of the light guide layer, the height of the fine pattern layer formed on the layer, the total thickness of the composite reflective polarizing film, the minimization of brightness reduction, etc. Since it can be designed differently depending on the desired physical properties, it is not particularly limited, but the light guiding property to be achieved through the multi-functional layer, the support of the fine pattern layer and the reliability of the composite reflective polarizing film. From the aspect of (1), it is preferable to have a thickness of 400 to 1000 μm, and more preferably 600 to 900 μm in order to exhibit a remarkable phase-raising effect with the reliability support layer. If the thickness of the light guide layer is less than 400 μm, the light guide layer's original function of guiding light may be degraded. Also, if the thickness of the light guide layer exceeds 1000 μm, the brightness may be significantly reduced, and the thicker light guide layer is not very preferable for thinning the composite reflective polarization film. There is a problem that the use may be restricted in view of the tendency of slimming the backlight unit including the display unit and the display panel including the unit. Further, when considering the reliability of the composite reflective polarizing film, it is preferable that the total thickness of the reliability supporting layer and the light guide layer has a certain thickness range, but the increase of the thickness of the light guide layer does not occur. , The reliability of the composite reflective polarizing film is reduced because the reliability supporting layer does not prevent the reflective polarizing film from being wrinkled or bent. Very unfavorable in.

In addition, a second primer layer for enhancing adhesion may be further included between the reliability support layer and the multi-functional layer, which is the same as the second embodiment described above. The explanation is omitted.

Meanwhile, the third embodiment described above includes (A) a step of forming a light diffusion layer on the upper surface of the reflective polarizing film; and (B) a lower surface of the reflective polarizing film so that the upper surface of the reliability supporting layer abuts. And (C) a step of forming a multi-functional layer on the lower surface of the reliability support layer, the steps (A) to (B) being performed in order. It can be manufactured independently.

The steps (A) to (C) correspond to the steps (a) to (c) of the second ward (constituent) courtesy described above, and a multi-functional layer is formed instead of the light collecting layer of the step (c). The description of the manufacturing method is the same except that it is performed, and thus a detailed description thereof will be omitted.

On the other hand, in the composite reflective polarizing film manufactured according to the first to third embodiments of the present invention, the haze value of the composite reflective polarizing film may be 65% or more, preferably 73% or more, and It may preferably be 85% or more. By satisfying the haze value, it is possible to prevent the appearance of various foreign substances, bubbles and the like that may be contained in the film during the manufacturing process, and improve the appearance quality. If the above range is not satisfied, the quality of the appearance deteriorates, and there is a problem in that a separate device or a separate other structure must be added in order to prevent foreign matter from appearing. This is not preferable in slimming the composite reflective polarizing film, and there is a problem that the manufacturing time and manufacturing cost increase due to the added structure.

The composite reflective polarizing film described above may be used in a light source assembly or a liquid crystal display device including the same, and may be used to enhance light efficiency. The light source assembly is classified into a direct type light source assembly in which the lamp is located at the bottom and an edge type light source assembly in which the lamp is located at the side. However, the composite reflective polarizing film according to an embodiment of the present invention may include any type of light source assembly. It can also be used for. Further, the present invention is also applicable to a backlight assembly arranged below the liquid crystal panel and a front light assembly arranged above the liquid crystal panel. Hereinafter, as an example of various application examples, a case where the composite reflective polarizing film according to one embodiment as shown in FIG. 5 or FIG. 26 is applied to a liquid crystal display device including an edge type light source assembly will be described.

FIG. 30 is a cross-sectional view of a liquid crystal display device according to a preferred embodiment of the present invention, wherein the liquid crystal display device 2000 includes a backlight unit 2400 and a liquid crystal panel assembly 2500.

The backlight unit 2400 includes a composite reflective polarizing film 2111 that modulates the optical characteristics of the emitted light, where the other configuration included in the backlight unit and the position of the composite reflective polarizing film 2111 with the other configuration. The relationship is not particularly limited in the present invention because the relationship can be changed according to the purpose.

However, according to a preferred embodiment of the present invention, as shown in FIG. 30, a light source 2410, a light guide plate 2420 for guiding light emitted from the light source 2410, a reflective film 2315 disposed below the light guide plate 2420, and a light guide plate 2420. It may be constructed and arranged with a composite reflective polarizing film 2111 arranged above the light plate 2420.

At this time, the light sources 2410 are arranged on both sides of the light guide plate 2420. The light source 2410 may be an LED (Light Emitting Diode), a CCFL (Cold Cathode Fluorescent Lamp), an HCFL (Hot Cathode Fluorescent Lamp), an EEFL (External Electron Fluorescent), or the like. In another embodiment, the light source 2410 may be disposed only on one side of the light guide plate 2420.

The light guide plate 2420 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 2420. A reflection film 2415 is disposed below the light guide plate 2420 to reflect the light emitted downward from the light guide plate 2420 to the upper part.

The composite reflective polarizing film 2111 is disposed on the light guide plate 2420. Since the composite reflective polarizing film 2111 has been described in detail above, duplicate description will be omitted. Another optical sheet 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 can be further installed.

The light source 2410, the light guide plate 2420, the reflective film 2415, and the composite reflective polarizing film 2111 may be housed by the bottom chassis 2440.

The liquid crystal panel assembly 2500 includes a first display plate 2511, a second display plate 2212 and a liquid crystal layer (not shown) interposed therebetween, and is attached to the surfaces of the first display plate 2411 and the second display plate 2412, respectively. A polarizing plate (not shown) may be further included.

The liquid crystal display device 2000 may further include a top chassis 2600 that covers a frame of the liquid crystal panel assembly 2500 and surrounds side surfaces of the liquid crystal panel assembly 2500 and the backlight unit 2300.

On the other hand, FIG. 31 shows an example of a liquid crystal display device employing the composite reflective polarizing film of the present invention, in which a reflective plate 3280 is inserted on a frame 3270, and a cold cathode fluorescent lamp 3290 is positioned on the upper surface of the reflective plate 3280. To do. An optical film 3320 is disposed on the upper surface of the cold cathode fluorescent lamp 3290, and the optical film 3320 may include a diffusion plate 3321, a composite reflective polarizing film 3322, and an absorbing polarizing film 3323, which are included in the optical film. Further, the stacking order between the components can be changed depending on the purpose, and some components may be omitted or a plurality of components may be provided. As a result, a retardation film (not shown) or the like can also be inserted at an appropriate position in the liquid crystal display device. Meanwhile, the liquid crystal display panel 3310 may be disposed on the upper surface of the optical film 3320 by being fitted to the mold frame 3300.

The light path will be mainly described. Light emitted from the cold cathode fluorescent lamp 3290 reaches the diffusion plate 3321 of the optical film 3320. The light transmitted through the diffusing plate 3321 travels through the composite reflective polarizing film 3322 to cause the light modulation to travel in a direction perpendicular to the optical film 3320. Specifically, P-waves pass through the reflective polarizing film without loss, but in the case of S-waves, light modulation (reflection, scattering, refraction, etc.) occurs and is reflected on the back surface of the cold cathode fluorescent lamp 3290. After being reflected by the plate 3280 and the property of the light is changed to P wave or S wave at random, it further passes through the composite reflective polarizing film 3322. Then, after passing through the absorption polarization film 3323, the liquid crystal display panel 3310 is reached. Meanwhile, the cold cathode fluorescent lamp 3290 may be replaced with an LED.

The embodiment described above can effectively exhibit a plurality of light modulation characteristics by applying the composite reflective polarizing film according to one embodiment of the present invention, and can improve the brightness, light leakage, and bright line. It is possible to prevent the appearance defect in which the foreign matter appears in the appearance without causing the appearance, and at the same time, it is possible to ensure the reliability of the composite reflective polarizing film even in a hot and humid environment where the liquid crystal display device is used. In addition, since the light diffusion layer and the light collection layer having respective functions are integrated with the reflective polarization film, the thickness of the light source assembly can be reduced, and the assembly process can be simplified. Accordingly, the image quality of a liquid crystal display device including such a light source assembly may be improved.

On the other hand, in the present invention, the use of the reflective polarizing film has been mainly described in the liquid crystal display, but the present invention is not limited to this, and is widely used in flat panel display technology such as projection display, plasma display, field emission display and electroluminescent display. Can be done.

The present invention will be more specifically described through the following examples, but the following examples do not limit the scope of the present invention, which should be construed as helping the understanding of the present invention.

<Example 1>
Polyethylene naphthalate (PEN) having a refractive index of 1.65 as a dispersion component, and polycyclohexylene diene obtained by polymerizing 60% by weight of polycarbonate as a base component with terephthalate, ethyl glycol and cyclohexanedimethanol in a molar ratio of 1:2. A raw material containing 38% by weight of methylene terephthalate (PCTG) and 2% by weight of a heat stabilizer containing a phosphate was introduced into the first extrusion section and the second extrusion section, respectively. As a skin layer component, 60% by weight of polycarbonate contained 38% by weight of polycyclohexylene dimethylene terephthalate (PCTG) obtained by polymerizing terephthalate, ethyl glycol, and cyclohexanedimethanol at a molar ratio of 1:2, and a phosphate. 2% by weight of the obtained heat stabilizer was added to the third extrusion section.

The extrusion temperature of the base material component and the dispersion component was 245° C., and Cap. Rheometer confirms I. V. The flow of the polymer is corrected through adjustment, and the dispersion mixture is guided through the flow passage to which the Filtering Mixer is applied so that the dispersion is randomly dispersed inside the substrate. Thereafter, the skin layer component is provided on both sides of the substrate layer component. Overlaid. The polymer was induced for spreading with the coat-hanger dies of Figures 18 and 19 which compensate for flow rate and pressure gradient. Specifically, the width of the die inlet is 200 mm, the thickness is 10 mm, the width of the die outlet is 1,260 mm, the thickness is 2.5 mm, and the flow velocity is 1.0 m/ It was min. Then, it was cooled and subjected to a smoothing process with a cast roll, and stretched 6 times in the MD direction. Next, heat setting was performed using a heater chamber at 180° C. for 2 minutes to produce a random dispersion type reflective polarizing film having a thickness of 120 μm (the thickness including the skin layer was 300 μm). The refractive index of the polyethylene naphthalate (PEN) component of the produced reflective polarizing film is (nx: 1.88, ny: 1.58, nz: 1.58), and 60% by weight of polycarbonate contains terephthalate and ethyl glycol. Cyclohexanedimethanol 38% by weight of polycyclohexylene dimethylene terephthalate (PCTG) polymerized by a polymerization reaction at a molar ratio of 2% by weight of a heat stabilizer containing a phosphate has a refractive index of 1 It was 0.58. At this time, the thickness of the core layer was 120 μm, the thickness of the skin layer was 40 μm on each of the upper and lower surfaces, and the total thickness of the reflective polarizing film was 200 μm.

Then, the manufactured reflective polarizing film was subjected to a process as shown in FIG. 21 to form a light diffusing layer including a urethane acrylic microlens 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 μm.

On the other hand, as a reliability supporting layer, polyethylene terephthalate (PET) film (EXCELL, Toray's leading edge material) with a thickness of 188 μm was obtained by biaxially stretching in the longitudinal direction and the transverse direction four times in each direction and then heat-setting at 190° C. 15% by weight of DPHA (Dipentaerythritol Hexaacrylate), 15% by weight of DPPA (Dipentaerythritol Pentaacylate), 12% by weight of TMPTA (trimethylolpropane triacylate), 20% by weight of phenoxyethyl methacrylate (PEA) of phenoxyethyl acrylate (PEA), and 20% of phenoxyethyl acrylate (PEA) of phenoxyethyl acrylate (PEA). %, 2-hydroxyethyl methacrylate (2-HEMA) 8% by weight and 2-hydroxyethyl acrylate (2-HEA) 5% by weight after manufacturing a reliable support layer formed in a thickness of 5 μm. Then, the lower surface of the reflective polarizing film on which the light diffusion layer was formed and the surface of the PET film on which the adhesive was formed were laminated so as to be in contact with each other, to manufacture a composite reflective polarizing film as shown in Table 1.

<Examples 2 to 11>
A composite reflective polarizing film was manufactured in the same manner as in Example 1, except for the conditions shown in Table 1 below.

At this time, the height of the lenticular lens of Example 8 was 20 μm, the pitch was 40 μm, and the height of the prism pattern of Example 9 was 20 μm, and the pitch was 40 μm.

The reliability support layer used in Example 10 was a PET film (EXCELL, Toray Advanced Materials) having a linear expansion coefficient of 24.69 μm/m·° C. in the temperature range of 70 to 80° C.

The reliability support layer used in Example 11 was a PET film (Toyobo Co., Ltd.) having a linear expansion coefficient of 27.27 μm/m·° C. in the temperature range of 70 to 80° C.

<Example 12>
The same procedure as in Example 1 was carried out. Instead of the random dispersion type reflective polarizing film, a plate-shaped polymer dispersed reflective polarizing film prepared by the following method was prepared. A composite reflective polarizing film was produced.

The plate-shaped polymer dispersed reflective polarizing film was processed as shown in FIG. Specifically, a substance obtained by mixing PEN having a refractive index of 1.65 as a first component and dimethyl terephthalate and dimethyl-2,6-naphthalenedicarboxylate as a second component in a molar ratio of 6:4 is ethylene glycol. Co-PEN having a refractive index of 1.64 reacted with (EG) at a molar ratio of 1:2 and 90 wt% of polycarbonate as a skin layer component and polycyclohexylene dimethylene terephthalate (PCTG). A polycarbonate alloy having a refractive index of 1.58, which was polymerized at 10% by weight, was placed in each of the first extruding section 220, the second extruding section 221, and the third extruding section 222. The extrusion temperature of the first component and the second component was 295° C., and Cap. Rheometer confirms I. V. The polymer flow was corrected through adjustment and the skin layer was extruded at a temperature level of 280°C. 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 rate of the first pressurizing means is 8.9 kg/h in order, and the discharge rate of the second pressurizing means is 8.9 kg/h. A sea-island type composite flow was manufactured using the sea-island type extrusion die as shown in FIG. Specifically, in the sea-island type extrusion die, the number of island component layers of the fourth die distribution plate S4 is 400, and the diameter of the die hole of the island component supply passage is 0.17 mm. Was 25,000. The diameter of the discharge port of the sixth mouthpiece distribution plate was 15 mm×15 mm. In the feedblock having a three-layer structure, the skin layer components flowed from the third extruded portion through the flow channels to form skin layers on the upper and lower surfaces of the sea-island composite flow (core layer polymer). The core layer polymer with the skin layer formed was induced to spread by the coat-hanger die shown in FIGS. Specifically, the width of the die inlet was 200 mm, the thickness was 20 mm, the width of the die outlet was 960 mm, the thickness was 2.4 mm, and the flow velocity was 1 m/min. .. Then, it was cooled and subjected to a smoothing process with a cast roll, and stretched 6 times in the MD direction. As a result, in the first component, the length of the major axis of the cross section in the length direction did not change, but the length of the minor axis decreased. Then, heat fixing was performed at 180° C. for 2 minutes using an IR heater to manufacture a reflective polarizing film in which a polymer as shown in FIG. 34 was dispersed. The manufactured reflective polarizing film had a first component having a refractive index of (nx: 1.88, ny: 1.64, nz: 1.64) and a second component having a refractive index of 1.64. It was The aspect ratio of the polymer is about 1/18000, the number of layers is 400 layers, the length of the short axis (thickness direction) is 84 nm, the length of the long axis is 15.5 mm, and the average optical thickness is The length was 138 nm. At this time, the manufactured reflective polarizing film core layer had a thickness of 59 μm, and the skin layer had a total thickness of 141 μm on the upper and lower surfaces.

<Comparative Examples 1 to 4>
A composite reflective polarizing film was manufactured in the same manner as in Example 1, except for the conditions shown in Table 2 below.

At this time, as the reliability supporting layer in Comparative Example 4, a PET film (TSI) having a linear expansion coefficient of 36.25 μm/m·° C. in the temperature range of 70 to 80° C. was used.

<Experimental Example 1>
The following physical properties were evaluated for the composite reflective polarizing films manufactured through Examples 1 to 12 and Comparative Examples 1 to 5, and the results are shown in Tables 1 and 2.

1. Relative Brightness The brightness of the manufactured composite reflective polarizing film was measured as follows. After assembling the panel on the 32" direct type backlight unit provided with the diffuser plate and the composite reflective polarizing film, the brightness was measured at 9 points using the BM-7 measuring machine of Topcon Corporation and the average was measured. The relative brightness is a relative value of the brightness of other examples and comparative examples when the brightness of the composite reflective polarizing film of Example 1 is set to 100 (reference).

2. Bright line visibility After the panel was assembled on a 32" direct-type backlight unit provided with a composite reflective polarizing film, a diffusion plate, a diffusion sheet, a prism sheet, and a brightness enhancement film, the bright line visibility was evaluated. In the evaluation, when the number of the bright lines is 0, it is very good, when the number of the bright lines is 0, it is very good, when it is 2 or more, it is usually 4 to 5 or more. If so, it was evaluated as defective.

3. Polarization degree The polarization degree was measured using the RETS-100 analyzer of OTSKA.

4. Haze measurement

The haze was measured using a haze and a transmittance measuring device (a product of Nippon Denshoku Kogyo Co.) analysis equipment.

5. Appearance of foreign matter By visually observing the appearance of the composite reflective polarizing film, it is evaluated whether the foreign matter in the film is visible. As a result, if the foreign matter is not expressed, it is indicated by 0, depending on the degree to which the foreign matter is expressed. It was shown by 1-5.

6. Evaluation of reliability After the composite reflective polarizing film was left at 60° C. and relative humidity of 75%, it was first observed for 96 hours, and then the change degree was observed up to 1000 hours, and the appearance of the composite reflective polarizing film was distorted or wrinkled. It was evaluated whether there was a change such as occurrence of. As a result of the evaluation, the case where there is no change in appearance is shown as 0, and the more severe the change is, the case is shown as 1-5.

Specifically, as can be seen from Tables 1 and 2, Examples 1 to 5 were superior to Examples 6 and 7 in brightness, polarization degree, and bright line visibility.

On the other hand, Example 1, which belongs to the range of the 1/3 group according to a preferred embodiment of the present invention, showed superior optical physical properties as compared with Examples 2 to 4, which did not satisfy this requirement. As a result, the optical properties of Example 1 were extremely superior to those of Example 5 in which the content of one group was out of the range.

In addition, in Examples 1, 8 and 9, the case where the shape of the fine pattern included in the light diffusion layer is a microlens is remarkably excellent in the development of higher haze physical properties than the case where the shape is a prism or a lenticular shape. It can be confirmed that, along with this, Example 1 is more excellent in physical properties such as visual recognition of bright lines and appearance of foreign matter.

Further, when the linear expansion coefficient of the reliability support layer exceeds 25 μm/m·° C. through Examples 1, 10 and 11, the reliability may be lower than that of Examples 1 and 10. Can be confirmed.

In addition, in the case of Example 12 in which the plate-shaped polymer dispersion type reflective polarizing film was changed, it can be confirmed that the optical characteristics such as luminance and polarization degree were very poor as compared with Example 1.

In addition, in the case of Example 1 including the reliability supporting layer, it can be confirmed by the evaluation of the reliability that excellent physical properties are realized, but the remaining configuration is the same, and only the reliability supporting layer is used. It can be confirmed that Comparative Example 1 which does not include the reliability has the effect of improving the brightness by not including the reliability supporting layer, but the reliability is remarkably lowered.

In addition, in Comparative Examples 2 and 3 not including the light diffusion layer, it was confirmed that the haze value was remarkably reduced as compared with Example 1 including the light diffusion layer, and it was poor in visual recognition of the bright line, and the foreign matter was remarkably expressed. can do.

Further, it can be confirmed that in the case of Comparative Example 4 in which the linear expansion coefficient of the reliability support layer according to the present invention is not satisfied, the desired reliability cannot be achieved.

<Example 13>
Polyethylene naphthalate (PEN) having a refractive index of 1.65 as a dispersion component, and polycyclohexylene diene obtained by polymerizing 60% by weight of polycarbonate as a base component with terephthalate, ethyl glycol and cyclohexanedimethanol in a molar ratio of 1:2. Raw materials containing 38% by weight of methylene terephthalate (PCTG) and 2% by weight of a heat stabilizer containing a phosphate were introduced into the first extrusion section and the second extrusion section, respectively. As a skin layer component, 60% by weight of polycarbonate contained 38% by weight of polycyclohexylene dimethylene terephthalate (PCTG) obtained by polymerizing terephthalate, ethyl glycol, and cyclohexanedimethanol in a molar ratio of 1:2, and a phosphate. 2% by weight of the obtained heat stabilizer was added to the third extrusion section.

The extrusion temperature of the base material component and the dispersion component was 245° C., and Cap. Rheometer confirms I. V. The flow of the polymer is corrected through the adjustment, and the dispersion mixer is guided to pass through the flow passage to which the filtration mixer is applied so that the dispersion is randomly dispersed inside the base material. Thereafter, the skin layer component is overlaid on both sides of the base layer component. I matched it. The polymer was induced to spread with the coat-hanger dies of FIGS. 19 and 20, which compensate for flow rate and pressure gradient. Specifically, the width of the die inlet is 200 mm, the thickness is 10 mm, the width of the die outlet is 1,260 mm, the thickness is 2.5 mm, and the flow velocity is 1.0 m/ It was min. Then, it was cooled and subjected to a smoothing process with a cast roll, and stretched 6 times in the MD direction. Next, heat fixing was performed through a heater chamber at 180° C. for 2 minutes to produce a random dispersion type reflective polarizing film having a thickness of 120 μm (thickness including a skin layer was 300 μm). The refractive index of the polyethylene naphthalate (PEN) component of the manufactured reflective polarizing film was (nx: 1.88, ny: 1.58, nz: 1.58), and 60 wt% of polycarbonate was mixed with terephthalate and ethyl glycol. And cyclohexanedimethanol 38% by weight of polycyclohexylene dimethylene terephthalate (PCTG) polymerized at a molar ratio of 2 and a thermal stabilizer 2% by weight containing a phosphate have a refractive index of It was 1.58. At this time, the thickness of the core layer was 120 μm, the thickness of the skin layer was 40 μm on each of the upper and lower surfaces, and the total thickness of the reflective polarizing film was 200 μm.

Then, the manufactured reflective polarizing film was subjected to a process as shown in FIG. 21 to form a light diffusing layer including a urethane acrylic microlens 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 μm.

On the other hand, a polyethylene terephthalate (PET) film (EXCEL, Toray's leading edge material) having a thickness of 188 μm, which was biaxially stretched 4 times in the longitudinal direction and the transverse direction in the reliability support layer and then heat-fixed to 190, was used. 15% by weight of DPHA (Dipentaerythritol Hexaacrylate), 15% by weight of DPPA (Dipentaerythritol Pentaacylate), 12% by weight of TMPTA (trimethylolpropane triacylate), 20% by weight of phenoxyethyl methacrylate (PEA) (phenoethylethyl acrylate (PEA)) and 25% by weight of phenoxyethylmethacrylate (PEA) (PEA). %, 2-hydroxyethyl methacrylate (2-HEMA) 8 wt% and 2-hydroxyethyl acrylate (2-HEA) 5 wt% after forming a reliable support layer having a thickness of 5 μm. Then, the second primer layer and the prism pattern portion of the prepared light-collecting layer were adhered so as to come into contact with each other. At this time, the light-collecting layer was biaxially stretched 4 times in the longitudinal direction and the transverse direction in the supporting part, and then heat-fixed to 190, and a polyethylene terephthalate (PET) film (EXCEL, Toray) having a thickness of 100 μm. The upper surface of the tip material) was prepared so as to include a urethane acrylic prism pattern having a refractive index of 1.59 (height: 20 μm, pitch: 40 μm) through the process shown in FIG.

Thereafter, DPHA (Dipentaerythritol Hexaacrylate) 15% by weight, DPPA (Dipentaerythritol Pentaacylate) 15% by weight, TMPTA (trimethylethylpropane triacylate) 12% by weight, phenoxy (Phenoxy Aphenate), phenoxy on the upper surface of the reliability supporting layer.
The first primer containing 25% by weight, 20% by weight of isobornyl methacrylate (IBOA), 8% by weight of 2-hydroxyethyl methacrylate (2-HEMA) and 5% by weight of 2-hydroxyethyl acrylate (2-HEA) was 5 μm. And then laminated so that the lower surface of the reflective polarizing film having the light diffusing layer formed thereon and the surface of the reliability supporting layer having the first primer formed on the PET film contact each other. A composite reflective polarizing film as shown in Table 1 was manufactured.

<Examples 14 to 18>
A composite reflective polarizing film was manufactured in the same manner as in Example 13, except for the conditions shown in Table 3 below. At this time, the height of the lenticular lens of Example 14 was 20 μm, the pitch was 40 μm, and the height of the prism pattern of Example 15 was 20 μm, and the pitch was 40 μm. The reliability support layer used in Example 16 was a PET film (EXCELL, Toray's advanced material) having a linear expansion coefficient of 24.69 μm/m·° C. in the temperature range of 70 to 80° C. The reliability support layer used in Example 17 was a PET film (Toyobo Co., Ltd.) having a linear expansion coefficient of 27.27 μm/m·° C. in the temperature range of 70 to 80° C.

<Example 19>
A composite reflective polarizing film as shown in Table 3 is manufactured by the same procedure as in Example 13, except that the plate-shaped polymer dispersed reflective polarizing film in Example 12 is used instead of the random dispersion reflective polarizing film. did.

<Examples 20 to 22>
A composite reflective polarizing film as shown in Table 4 below was prepared in the same manner as in Example 13 except that the thickness of the reliability supporting layer and/or the light collecting layer supporting portion was changed under the conditions shown in Table 4 below. Manufactured.

<Comparative Examples 5 to 9>
A composite reflective polarizing film was manufactured in the same manner as in Example 13, except for the conditions shown in Table 4 below.

At this time, as the reliability support layer in Comparative Example 9, a PET film (TSI) having a linear expansion coefficient of 36.25 μm/m·° C. in the temperature range of 70 to 80° C. was used.

<Experimental example 2>
The following physical properties were evaluated with respect to the composite reflective polarizing films manufactured through Examples 13 to 22 and Comparative Examples 5 to 9, and the results are shown in Tables 3 and 4.

1. Relative brightness, degree of polarization, visual recognition of bright lines, haze, presence/absence of foreign substance expression, and reliability Physical properties were evaluated in the same manner as in Experimental Example 1. At this time, the relative brightness was shown relative to the other examples and comparative examples with reference to Example 13.

2. Whether or not the equation is satisfied: When the value of the following equation 1 satisfies 0.16 to 2.0, it is indicated by ◯, and when it is not satisfied, it is indicated by x, and the value of the following equation 2 satisfies 0.25 to 4.0. Cases are indicated by ○, and unsatisfactory cases are indicated by ×.

As can be seen from Tables 3 and 4, when the shape of the fine pattern included in the light diffusion layer in Examples 13 to 15 is a microlens, the haze is smaller than that of a prism or a lenticular shape. It can be confirmed that the physical properties are remarkably excellent, and along with this, it can be confirmed that Example 13 is further excellent in the physical properties such as the visibility of bright lines and the appearance of foreign substances.

Further, when the linear expansion coefficient of the reliability support layer exceeds 25 μm/m·° C. through Examples 13, 16 and 17, the reliability may be reduced as compared with Examples 13 and 16. Can be confirmed. Further, it can be confirmed that the reliability of Comparative Example 9 in which the coefficient of linear expansion of the reliability support layer exceeds 35 μm/m·° C. is not significantly better than that of the Examples.

In addition, in the case of Example 19 in which the reflection polarizing film of the plate-shaped polymer dispersion type was used, it can be confirmed from Example 13 that the optical characteristics such as brightness and degree of polarization were not very good.

On the other hand, it can be confirmed that in Comparative Example 5, which does not include the light-collecting layer, as compared with Example 13, the optical characteristics such as the brightness are significantly reduced. Further, it was possible to confirm that a warp phenomenon in which the film was bent as a whole was generated, although wrinkles did not occur on the surface of the film and bending did not occur.

Further, in the case of Comparative Example 6 which does not include the reliability supporting layer, the optical properties such as brightness were expressed at a similar level to that of Example 13, but wrinkles and bending occurred in the surface appearance of the film, and the film as a whole was formed. It is possible to confirm that a bending warp phenomenon has occurred.

In addition, in the case of Comparative Example 7 which does not satisfy the numerical formula 1 according to the present invention, it can be confirmed that defects such as wrinkles and bending occur on the surface, or a severe warpage phenomenon occurs on the film. In this case, although it is excellent in reliability, it can be confirmed that the luminance is remarkably lowered, and it is understood that the composite reflective polarizing film is not thinned and is very unfavorable.

In addition, even when the formula 1 according to the present invention is satisfied, the example 21 that does not satisfy the formula 2 has a defect in which wrinkles and bends are generated on the surface as compared with the example 1, and the example 22 is a light collecting layer. It can be confirmed that the thickness is so thin that the total brightness of the reliability support layer and the light collection layer is lower than that of the similar example 1, that is, the brightness.

Claims (17)

A composite reflective polarizing film comprising a reflective polarizing film having a polymer dispersed inside a substrate, wherein the composite reflective polarizing film is:
A light diffusing layer formed on the upper surface of the reflective polarizing film and including a fine pattern that is a microlens ;
A reliability support layer formed on the lower surface of the reflective polarizing film;
The reliability support layer is not formed on other surfaces in the composite reflective polarizing film except the lower surface of the reflective polarizing film,
The following conditions (1) and (2),
(1) The reliability support layer has a linear expansion coefficient of 4 to 25 μm/m·° C. in a temperature range of 70 to 80° C.
(2) The haze value of the composite reflective polarizing film is 73% or more,
A composite reflective polarizing film, which satisfies: The composite reflective polarizing film according to claim 1, wherein the reliability support layer is a polyester film stretched in at least one direction. The composite reflective polarizing film according to claim 1, wherein the reliability support layer has a thickness of 10 to 600 μm. The composite reflective polarizing film according to claim 1, wherein, under the condition (1), the reliability support layer has a linear expansion coefficient of 10 to 25 μm/m·°C in a temperature range of 70 to 80°C. The reflective polarizing film,
A plurality of dispersions for transmitting the first polarized light and the second polarized light, which are included in the base material and are irradiated from the outside, and which are included in the base material; The refractive index differs from the substrate in at least one axial direction,
80% or more of the plurality of dispersions contained in the base material have an aspect ratio of the length of the short axis to the length of the long axis of 1/2 or less based on the vertical cross section in the length direction. ,
The dispersion having an aspect ratio of ½ or less is included in at least three groups according to cross-sectional areas,
Sectional area of the dispersion of the first group among the groups is 0.2 to 2.0 [mu] m ^2, the cross-sectional area of the dispersion of the second group is an 5.0 .mu.m ² or less from the 2.0 .mu.m ² exceeded , The cross-sectional area of the third group of dispersions is more than 5.0 μm ² to 10.0 μm ² or less,
The composite reflective polarizing film according to claim 1, wherein the dispersions of the first to third groups are randomly arranged. The reflective polarizing film,
A core layer including a base material and a plurality of dispersions contained in the base material; and an integrated skin layer formed on at least one surface of the core layer. Item 5. The composite reflective polarizing film as described in Item 5 . A composite reflective polarizing film comprising a reflective polarizing film having a polymer dispersed inside a substrate, wherein the composite reflective polarizing film is:
A reliability support layer formed on the upper surface of the reflective polarizing film;
A light diffusing layer formed on the upper surface of the reliability supporting layer and including a fine pattern that is a microlens ;
The reliability support layer is not formed on other surfaces in the composite reflective polarizing film except the upper surface of the reflective polarizing film,
The following conditions (1) and (2),
(1) The reliability support layer has a linear expansion coefficient of 4 to 25 μm/m·° C. in a temperature range of 70 to 80° C.
(2) The haze value of the composite reflective polarizing film is 73% or more,
A composite reflective polarizing film, which satisfies: A composite reflective polarizing film comprising a reflective polarizing film having a polymer dispersed inside a substrate, wherein the composite reflective polarizing film is:
A light diffusing layer formed on the upper surface of the reflective polarizing film and including a fine pattern that is a microlens ;
A reliability support layer formed on the upper surface of the light diffusion layer;
The reliability support layer is not formed on the other surface in the composite reflective polarizing film except the upper surface of the light diffusion layer,
The following conditions (1) and (2),
(1) The reliability support layer has a linear expansion coefficient of 4 to 25 μm/m·° C. in a temperature range of 70 to 80° C.
(2) The haze value of the composite reflective polarizing film is 73% or more,
A composite reflective polarizing film, which satisfies: A composite reflective polarizing film comprising a reflective polarizing film having a polymer dispersed inside a substrate, wherein the composite reflective polarizing film is:
A light diffusing layer formed on the upper surface of the reflective polarizing film;
A reliability support layer formed on the lower surface of the reflective polarizing film;
A light collecting layer formed on a lower surface of the reliability support layer;
The reliability support layer is not formed on other surfaces in the composite reflective polarizing film except the lower surface of the reflective polarizing film,
The following conditions (1) and (2),
(1) The reliability support layer has a linear expansion coefficient of 4 to 25 μm/m·° C. in a temperature range of 70 to 80° C.
(2) The haze value of the composite reflective polarizing film is 73% or more,
A composite reflective polarizing film, which satisfies: The light collecting layer is
A support part and a prism pattern part formed on the support part,
The composite reflective polarizing film of claim 9 , wherein the prism pattern portion is formed to face a lower surface of the reliability support layer. The composite reflective polarizing film according to claim 10 , wherein the supporting part has a thickness of 10 to 300 µm. A composite reflective polarizing film comprising a reflective polarizing film having a polymer dispersed inside a substrate, wherein the composite reflective polarizing film is:
A light diffusing layer formed on the upper surface of the reflective polarizing film;
A reliability support layer formed on the lower surface of the reflective polarizing film;
A light collecting layer formed on a lower surface of the reliability supporting layer, the light collecting layer including a supporting portion;
The reliability support layer is not formed on other surfaces in the composite reflective polarizing film except the lower surface of the reflective polarizing film,
Formula 1 below for the thickness of the reflective polarizing film, the thickness of the reliability support layer, and the thickness of the support portion of the light collection layer,

The value of is 0.3-2.0, The composite reflective polarizing film characterized by the above-mentioned. The following Equation 2 for the thickness of the reliability support layer and the thickness of the support portion of the light collecting layer,

The value of is 0.25-4, The composite reflective polarizing film of Claim 12 characterized by the above-mentioned. A composite reflective polarizing film comprising a reflective polarizing film having a polymer dispersed inside a substrate, wherein the composite reflective polarizing film is:
A light diffusing layer formed on the upper surface of the reflective polarizing film and including a fine pattern that is a microlens ;
A reliability support layer formed on the lower surface of the reflective polarizing film;
A multi-function layer formed under the reliability support layer, for guiding and collecting light emitted from a light source,
The reliability support layer is not formed on other surfaces in the composite reflective polarizing film except the lower surface of the reflective polarizing film,
The following conditions (1) and (2),
(1) The reliability support layer has a linear expansion coefficient of 4 to 25 μm/m·° C. in a temperature range of 70 to 80° C.
(2) The haze value of the composite reflective polarizing film is 73% or more,
A composite reflective polarizing film, which satisfies: The multi-functional layer is
A fine pattern layer that collects light emitted from a light source;
The composite reflective polarizing film of claim 14 , further comprising: a light guide layer formed under the fine pattern layer, the light guide layer supporting the fine pattern layer and guiding light emitted from a light source. Backlight unit including a composite reflective polarizing film according to any one of claims 1~ 15 (unit). A liquid crystal display device comprising the backlight unit according to claim 16 .

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