KR20170111936A - Coating composition for reflective polarizing film and method for manufacturing reflective polarizing film by thereof - Google Patents

Abstract

The present invention relates to a coating liquid composition for a reflective polarizing film and a method for producing the reflective polarizing film through the same. More specifically, the present invention relates to a coating liquid composition for a reflective polarizing film which is low in wettability, excellent in leveling, Therefore, the coating liquid composition of the reflection type polarizing film which has few coating portions, has no coating unevenness and does not dissolve the base material, has good adhesion with the substrate, does not cause contamination, and has a high yield. .

Description

TECHNICAL FIELD The present invention relates to a reflective polarizing film coating composition composition and a reflective polarizing film composition,

The present invention relates to a coating liquid composition for a reflective polarizing film and a method for producing the reflective polarizing film through the same. More specifically, the present invention relates to a polarizing film having a low wettability, A coating liquid composition of a reflection type polarizing film having good adhesion to a substrate and no contamination and a high yield because the coating is uneven and the substrate is not dissolved, To a process for producing the same.

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

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

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

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

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

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

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

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

Skin layers 9 and 10 are formed on both sides of the base material 8 and separate adhesive layers 11 and 12 are formed between the base material 8 and the skin layers 9 and 10 for bonding them.

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

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

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

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

In order to overcome this problem, a technical idea including a birefringent sea chart was proposed in the substrate. FIG. 4 is a cross-sectional view of a birefringent chart paper included in the inside of the base material. The birefringent chart paper can generate a light modulation effect at the light modulation interface of the internal part and the dissolution part, The optical properties can be achieved without arranging chart marks. However,

Fiber, problems of compatibility with a base material such as a polymer, ease of handling, and adhesiveness have arisen. Furthermore, the light-scattering is induced by the circular shape, and the reflection polarizing efficiency against the light wavelength in the visible light region is lowered. As a result, the polarizing characteristic is lowered compared with the existing product and the luminance improvement is limited. In addition, As the area is subdivided, due to the occurrence of pores, light leakage, that is, light loss phenomenon, has been caused. In addition, due to the structure of the fabric in the form of a structure, there is a problem that limitations are imposed on improvement of reflection and polarization characteristics due to limitations of the layer structure. Also, in the case of the dispersion type reflective polarizer, the problem of the appearance of the bright line appears due to the space between the layers and the space between the dispersion bodies.

Recently, a technique for constructing a skin layer of a reflective polarizer as a polycarbonate layer has been disclosed. In this case, toluene and methyl ethyl ketone (MEK) are used as a solvent for a bead coating layer coated on a polycarbonate material. Coating was carried out using the same additives. in this case Leveling and particle dispersion are good. However, since the solvent dissolves the polycarbonate material, process contamination and coating unevenness occur. In addition, since the wetting property is low, the leveling is excellent, the particles are dispersed well, the portion not coated is small, there is no coating unevenness, and the adhesion of the substrate to the substrate is low There is a problem that it is difficult to achieve the effect of not causing contamination and high yield.

KR 2011-0057764 Manufacturing method of A reflective polarizer

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a coating liquid which is low in wettability, leveling, And to provide a reflection type polarizing film coating composition having a low yield. In addition, at the same time, it is an object of the present invention to provide a reflection type polarizing film coating liquid composition which has no coating unevenness and does not dissolve the base material, has good adhesion with a substrate, does not cause contamination, and has a high yield.

In order to solve the above problems, the present invention provides a reflective polarizing film comprising a core layer and a polycarbonate skin layer formed on at least one side of the core layer, wherein the polycarbonate skin layer is coated with propylene glycol monomethyl ether (PGME ), A binder and bead particles.

According to a preferred embodiment of the present invention, the binder may be a urethane binder.

According to another preferred embodiment of the present invention, the bead particles may be acrylic bead particles.

According to another preferred embodiment of the present invention, the acrylic bead particles may have an average particle diameter of 1 to 50 μm.

According to another preferred embodiment of the present invention, the acrylic bead particles may have the same or different particle diameters.

According to another preferred embodiment of the present invention, the coating liquid composition may contain 35 to 55% by weight of the propylene glycol monomethyl ether, 35 to 50% by weight of the binder, and 1 to 25% by weight of the bead particles have.

According to another preferred embodiment of the present invention, the coating liquid composition may not contain any one or more additives selected from the group consisting of a defoaming agent and a dispersing agent.

According to another preferred embodiment of the present invention, the coating liquid composition may not contain both a defoaming agent and a dispersing agent.

According to another aspect of the present invention, there is provided a method of manufacturing a polarizing plate, comprising the steps of: (1) preparing a reflective polarizer including a core layer and a polycarbonate skin layer formed on at least one side of the core layer; And (2) coating at least one surface of the polycarbonate skin layer with the coating solution of any one of the first to seventh aspects.

According to another preferred embodiment of the present invention, (3) the coated polycarbonate skin layer may further be dried at 70 to 90 ° C for 0.5 to 2 minutes.

According to another preferred embodiment of the present invention, (4) the step of irradiating the dried polycarbonate skin layer with ultraviolet light (UV) at 70 to 90 Kw for 5 to 15 seconds may be further included.

According to another aspect of the present invention, there is provided a semiconductor device comprising: a core layer; A polycarbonate skin layer formed on at least one side of the core layer; And a coating layer comprising bead particles formed on at least one side of the polycarbonate skin layer, wherein the coating layer does not include a defoaming agent or a dispersing agent.

According to a preferred embodiment of the present invention, the coating layer includes a binder layer, and the thickness of the binder layer may be 10 to 150 [mu] m.

According to another preferred embodiment of the present invention, the bead particles may be acrylic bead particles.

According to another preferred embodiment of the present invention, the coating layer may not include both a defoaming agent and a dispersing agent.

According to another preferred embodiment of the present invention, the core layer and the polycarbonate skin layer may be integrally formed.

According to another preferred embodiment of the present invention, the core layer can disperse the second component inside the first component.

Hereinafter, terms used in this specification will be described.

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

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

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

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

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

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

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

Since the coating liquid composition of the reflective polarizing film of the present invention does not dissolve the recently used polycarbonate skin layer It has no coating unevenness, does not cause contamination, has good adhesion with a substrate, has low wettability, has excellent leveling, and has good dispersion of particles even when no additives are added, And the refractive index and the reflectance can be easily controlled.

1 is a schematic view for explaining the principle of a conventional reflective polarizer.
2 is a cross-sectional view of a currently used multi-layer reflective polarizer (DBEF).
3 is a perspective view of a reflection type polarizer including a bar-shaped polymer.
4 is a cross-sectional view showing a path of light incident on a birefringent chart used for a reflection type polarizer.
5 is a cross-sectional view of a reflection type polarizing film according to a preferred embodiment of the present invention.
6 is a cross-sectional view of a reflection type polarizing film according to a preferred embodiment of the present invention.
7 is a cross-sectional view of a dispersion according to a preferred embodiment of the present invention.
Figure 8 is a cross-sectional view of a coat-and-cardboard die in accordance with a preferred embodiment of the present invention, and Figure 9 is a side view.
10 is an exploded perspective view of a reflection type polarizing film in which a dispersion containing a reflection type polarizing film of the present invention is dispersed according to another preferred embodiment of the present invention.

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

As described above, in the conventional structure, a technique of forming a skin layer of a reflective polarizer with a polycarbonate layer is disclosed. In this case, toluene and methyl ethyl ketone (MEK) were used as a solvent for the bead coating layer coated on the polycarbonate material , Antifoaming agents and dispersants. In this case, Leveling and particle dispersion are good. However, since the solvent dissolves the polycarbonate material, process contamination and coating unevenness occur. In addition, since the wetting property is low, the leveling is excellent, the particles are dispersed well, the portion not coated is small, there is no coating unevenness, and the adhesion of the substrate to the substrate is low There is a problem that it is difficult to achieve the effect of not causing contamination and high yield.

Accordingly, the present invention provides a reflective polarizing film comprising a core layer and a polycarbonate skin layer formed on at least one side of the core layer, wherein the polycarbonate skin layer is coated with propylene glycol monomethyl ether (PGME), a binder and bead particles The present invention provides a reflection type polarizing film coating composition comprising the above-mentioned reflective polarizing film coating composition. As a result, since the recently used polycarbonate skin layer is not dissolved It has no coating unevenness, does not cause contamination, has good adhesion with a substrate, has low wettability, has excellent leveling, and has good dispersion of particles even when no additives are added, Can be achieved.

First, a coating liquid composition for coating the reflective polarizing film of the present invention will be described. Wherein the coating liquid composition comprises a core layer and a polycarbonate skin layer formed on at least one side of the core layer, the reflective polarizing film comprising, in order to coat the polycarbonate skin layer, propylene glycol monomethyl ether (PGME), a binder and bead particles .

First, the solvent used in the present invention will be described. The solvent used in the present invention is propylene glycol monomethyl ether (PGME), and is a solvent optimized for the coating of a polycarbonate base. By using propylene glycol monomethyl ether (PGME) as a solvent, leveling is excellent without addition of any additive. Since the particles are dispersed well, there are few uncoated parts, no coating unevenness, and a polycarbonate skin layer It does not dissolve and can facilitate coating.

On the other hand, the coating layer is coated with a coating liquid containing bead particles, a binder and the above-mentioned solvent, and dried. As a result, propylene glycol monomethyl ether (PGME) as a solvent component is volatilized and only the bead particles and the binder layer remain.

5 is a cross-sectional view of a reflection type polarizing film according to a preferred embodiment of the present invention. The reflective polarizing film 100 includes a core layer 110 in which a plurality of dispersions are randomly dispersed and arranged, a skin layer 120 and 140 formed on at least one surface of the core layer 110, And a coating layer 130, 150 formed on the substrate.

First, the coating layers 130 and 150 will be described. The coating layers 130 and 150 coat at least one surface of the skin layers 120 and 140. If at least one surface of the skin layers 120 and 140 is not coated, And the problem of poor permeability may occur.

The coating layers 130 and 150 include a binder 131. The binder 131 functions to fix the coating components of the coating layers 130 and 150. The binder 131 can be used without limitation as long as it is a commonly used binder and is preferably composed of an acrylic binder, a urethane binder, a urethane-acrylic copolymer binder, an ester binder, an ether binder, an amide binder, an amide binder and an epoxy binder The use of a urethane binder is more advantageous for preventing the coating layers 130 and 150 from being peeled off from the skin layers 120 and 140.

Meanwhile, the thickness of the binder layer may be 10 to 150 mu m. If the thickness of the binder layer is less than 10 mu m, it is difficult to fix the bead particles, so that the bead particles may be separated from the binder layer. If the thickness of the binder layer exceeds 150 mu m, Lt; / RTI >

In addition, the coating layers 130 and 150 include bead particles 132. The bead particles 132 can be used without limitation as long as they are the bead particles 132 normally used in the coating liquid. Preferably, the bead particles 132 may be selected from the group consisting of methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, n-butyl methacrylate, Acrylic acid, methacrylic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl acrylate, acrylamide, methylol acrylamide, glycidyl methacrylate, ethyl acrylate At least one or more selected from the group consisting of isobutyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, polyethylene, acrylic, polystyrene and polypropylene can be used. More preferably, .

Meanwhile, according to one preferred embodiment of the present invention, the acrylic bead particles may have an average particle diameter of 1 to 50 μm. If the average particle diameter of the acrylic bead particles is less than 1 mu m, there may occur a problem of coating unevenness. If the average particle diameter exceeds 50 mu m, a problem of poor leveling may occur.

According to another preferred embodiment of the present invention, the particle size of the acrylic bead particles may be the same or different, and the particle size of the acrylic bead particle may be larger or smaller than the thickness of the binder layer.

Meanwhile, the thickness of the coating layers 130 and 150 may be 10-180 탆, preferably 10.5-176 탆.

According to another preferred embodiment of the present invention, the coating liquid composition for coating the skin layers 120 and 140 comprises 35 to 55% by weight of the propylene glycol monomethyl ether (PGME), 35 to 55% by weight of the binder 131, To 50% by weight of the bead particles 132 and 1 to 25% by weight of the bead particles 132. If the amount of the propylene glycol monomethyl ether (PGME) is less than 35% by weight, the resulting composition may have a high wettability, a poor leveling property, a poor dispersion of particles, The coating layers 130 and 150 can be peeled off from the skin layers 120 and 140 and the coating layer is formed on the resulting coating layer Problems can arise. If the binder 131 is less than 35 wt%, the bead particles 132 are not fixed and the coating layers 130 and 150 may be peeled off from the skin layers 120 and 140, , The content of the bead particles 132 and the propylene glycol monomethyl ether (PGME) is relatively decreased, so that the particles are not dispersed well and the adhesion with the substrate may be poor. If the amount of the bead particles is less than 1% by weight, the coatability is not improved. If the amount of the beads is more than 25% by weight, the adhesion of the coating layers 130 and 150 to the base layer There may arise a problem of peeling.

On the other hand, the coating layers 130 and 150 are coated with the coating composition described above and then dried. As a result, the propylene glycol monomethic ether (PGME) can be all volatilized after coating. If the propylene glycol monomethic ether (PGME) is not volatilized, the coating layers 130 and 150 may be peeled off from the skin layers 120 and 140, resulting in uneven coating.

Meanwhile, according to another preferred embodiment of the present invention, the coating liquid composition may not contain any one or more additives selected from the group consisting of a defoaming agent and a dispersing agent.

Antifoaming agents are drugs used to remove harmful air bubbles. In the vesicular action, there is a pore action and a suppression action. The pale action can remove the generated air bubbles, but it can not prevent air bubbles from being generated. The air bubble action can prevent air bubbles, It can not be said. Common antifoaming agents include octyl alcohol, cyclohexanol, nonionic surfactants and the like.

Dispersant refers to a component added to disperse solid fine particles in a liquid and to make a stable solution. Commonly used dispersing agents include alkylalkoxysilane, siloxane, silane, and polycarboxylic acid.

Meanwhile, according to another preferred embodiment of the present invention, the coating liquid composition may not include both the antifoaming agent and the dispersant. Since the coating liquid composition according to the present invention exhibits the effect of reducing the production cost, simplifying the manufacturing process, and exhibiting a level of effect not significantly different from the coating liquid containing the defoaming agent and / or the dispersing agent, the addition of the defoaming agent and / There is no difference in effect between the coating liquids.

(1) preparing a reflective polarizer comprising a core layer and a polycarbonate skin layer formed on at least one side of the core layer, and (2) providing a polycarbonate skin layer on one side of the polycarbonate skin layer, And coating a coating liquid on the reflective polarizing film.

First, a step of preparing a reflective polarizer including a core layer and a polycarbonate skin layer formed on at least one side of the core layer will be described.

6 is a cross-sectional view of a reflection type polarizing film to which a coating liquid is not applied according to a preferred embodiment of the present invention. In FIG. 6, a plurality of dispersion bodies 201 to 206 are randomly dispersed in a base material 200, And a skin layer 207 integrally formed on at least one side of the core layer.

First, the core layer will be described. The core layer which can be applied to the present invention may be a multilayered semi-structured polarizer and a dispersed reflective polarizer in which the second component is dispersed in the first component, preferably a dispersed reflective polarizer.

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

The dispersion body having the aspect ratio of 1/2 or less includes three or more groups having different cross-sectional areas. Specifically, in FIG. 6, the first group of dispersions (201, 202) having the smallest cross-sectional area and the second group of dispersions (203, 204) having an intermediate cross-sectional area and the third group ) Are dispersed randomly. In this case, the cross-sectional area of the first group is 0.2 ~ 2.0㎛ ^2, and the cross-sectional area of the second group is ² or less from 5.0㎛ 2.0㎛ ^2, greater than the cross-sectional area of the third group is less than ² from 10.0㎛ 5.0㎛ than ^2, the The dispersoids of the first group, the dispersant of the second group and the dispersant of the third group are randomly arranged. If the dispersion of any one of the first to third groups of dispersants is not included, desired optical properties are difficult to achieve.

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

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

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

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

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

Meanwhile, according to one preferred embodiment of the present invention, the skin layer 207 is made of a polycarbonate base material, and a polycarbonate base material is used to prevent the occurrence of coating unevenness (stain) Do.

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

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

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

Next, the dispersion control unit induces spreading in the flow control unit so that the dispersion component contained in the substrate can be randomly arranged. Specifically, Figure 8 is a cross-sectional view of a coat-hanger die, which is one type of preferred flow control that may be applied to the present invention, and Figure 9 is a side view. The size and arrangement of the cross-sectional areas of the dispersion components can be controlled at random by appropriately adjusting the extent of spreading of the substrate. In FIG. 8, since the substrate on which the skin layer conveyed through the flow path is spread spreads widely left and right on the coat-hanger die, the dispersion component contained therein also spreads to the left and right.

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

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

Thereafter, a step of stretching the polarizer through the smoothing step is performed. The stretching can be performed through a conventional stretching process of a reflective polarizer, thereby causing a difference in refractive index between a base component and a dispersion component to cause a light modulation phenomenon at the interface, and the spreading induced first component Dispersion component) is further reduced in aspect ratio through stretching. For this purpose, the uniaxial stretching or biaxial stretching can be preferably performed in the stretching step, and more preferably uniaxial stretching can be performed. In the case of uniaxial stretching, stretching may be performed in the longitudinal direction of the first component. The stretching ratio may be 3 to 12 times. On the other hand, a method of changing an isotropic material to birefringent is commonly known. For example, in the case of stretching under an appropriate temperature condition, the dispersion molecules may be oriented so that the material becomes birefringent. Next, the final reflective polarizer can be manufactured through the steps of opening and fixing the stretched polarizer. The thermal fixation may be heat-set through a conventional method, preferably at 180 to 200 ° C for 0.1 to 3 minutes through an IR heater.

Next, (2) a step of coating any one of the coating liquids described above on at least one side of the polycarbonate skin layer will be described. The coating solution may be prepared by stirring propylene glycol monomethyl ether, a binder and bead particles at 1000 to 1500 rpm for 10 to 20 minutes in a stirrer.

Typically, the coating method can be largely divided into a dry coating and a wet coating. The wet coating is accomplished through solvent volatilization and curing processes after the coating material is mixed with the solvent and transferred to the surface of the material with a certain viscosity, while the dry coating is not used with a separate solvent.

Meanwhile, the coating method of the coating step can be used without limitation as long as it is generally used in a coating method. Preferably, a dry coating method such as chemical vapor deposition and ion beam sputtering, a gravure coating method using a wet coating method gravure coationg, microgravure coationg, capillary coationg and bar coating may be used. More preferably, microgravure coating may be used, but not limited thereto. Do not.

According to a preferred embodiment of the present invention, the step (2) may be followed by (3) drying the coated polycarbonate skin layer at 70 to 90 ° C for 0.5 to 2 minutes. The drying step serves to facilitate volatilization of the solvent. If the temperature of the drying step is less than 70 캜, the solvent may not be volatilized well, so that the coating layer may be peeled off from the skin layer, and coating unevenness may occur. When the temperature exceeds 90 캜, Since the coating layer and the skin layer are over-dried, the coating layer may peel off from the skin layer. If the drying time is less than 0.5 minutes, the solvent may not be volatilized well, so that the coating layer may be peeled off from the skin layer, resulting in uneven coating. If the drying time exceeds 2 minutes, There is a problem that the coating layer peels off from the skin layer because the layer is over-dried.

According to another preferred embodiment of the present invention, step (3) may be followed by (4) irradiating the dried polycarbonate skin layer with ultraviolet light (UV) at 70 to 90 Kw for 5 to 15 seconds. The step of irradiating ultraviolet rays functions to cure the coating layer to prevent peeling of the coating layer and the skin layer. If the ultraviolet ray (UV) is less than 70 Kw, the coating layer may not be cured well, and the coating layer and the skin layer may peel off. If the UV layer is over 90 Kw, the coating layer may be excessively cured, Problems can arise. If the ultraviolet ray irradiation time is less than 5 seconds, the coating layer may not be cured well and the coating layer and the skin layer may peel off. If the irradiation time exceeds 15 seconds, the coating layer is excessively cured, Can cause problems.

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

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

The present invention provides a method for producing a reflective layer comprising a core layer, a polycarbonate skin layer formed on at least one side of the core layer, and a coating layer comprising bead particles formed on at least one side of the polycarbonate skin layer, Type polarizing film.

According to a preferred embodiment of the present invention, the bead particles may be acrylic bead particles. If acrylic bead particles are not used as the bead particles, the problem of poor dispersibility of the particles may arise.

According to another preferred embodiment of the present invention, the coating layer may not include both a defoaming agent and a dispersing agent. If a defoaming agent and a dispersing agent are included, the yield may be poor and the adhesion may be relatively poor.

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

According to another preferred embodiment of the present invention, the core layer may disperse the second component in the interior of the first component, and may be preferably a dispersive reflective polarizer. The first component and the second component of the core layer are the same as those of the first component and the second component of the core layer of FIG. 6 described above, and the detailed description thereof will be omitted.

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

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, It will be understood that various changes and modifications may be made without departing from the scope of the present invention. For example, each component specifically shown in the embodiments of the present invention can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Hereinafter, the present invention will be described with reference to the following examples. The following examples are provided to illustrate the invention, but the scope of the present invention is not limited by the following examples.

≪ Example 1 >

(A) Preparation of reflective polarizing film

(PEN) having a refractive index of 1.65 as a dispersion component, and polycyclohexylenediamine (PEN) having a polymerization activity of 1: 2 by mole ratio of terephthalate, ethyl glycol and cyclohexane dimethanol to 60% by weight of polycarbonate as a base component A raw material containing 38% by weight of methyl cyclohexylene dimethylene terephthalate (PCTG) and 2% by weight of a heat stabilizer containing phosphate was charged into the first extruder and the second extruder, respectively. 100 parts by weight of polycarbonate as a skin layer component was added to the third extruding part.

The extrusion temperature of the base component and the dispersion component was adjusted to 245 占 폚, and Cap. The polymer flow was adjusted through adjustment, and the dispersion fluid was randomly dispersed in the substrate through the passage through which the filteration mixer was applied. Then, the skin layer components were laminated on both sides of the substrate layer component. The spread of the polymer was induced in the coat hanger die of Figures 8 and 9, which corrected the flow rate and pressure gradient. Specifically, the width of the die inlet is 200 mm, the thickness is 10 mm, the width of the die outlet is 1,260 mm, the thickness is 2.5 mm, and the flow rate is 1.0 m / min. Then, a smoothing process was performed on the cooling and casting rolls and stretched 6 times in the MD direction. Then, heat setting was carried out through a heater chamber at 180 캜 for 2 minutes to obtain a film having a thickness of 120 탆 (thickness including a skin layer of 300 탆) and the number of dispersions having a half or less of the number of dispersions was 1/2 %, A randomly dispersed polarizing film in which the number of dispersions belonging to the cross-sectional area ranges of 1 group, 2 group and 3 group in the dispersion having an aspect ratio of 1/2 or less was 49%, 39% and 12% Respectively. (Nx: 1.88, ny: 1.58, nz: 1.58) of the polyethelene naphthalate (PEN) component of the produced reflection type polarizing film and terephthalate, ethyl glycol and cyclohexanedimethanol 1 : 38% by weight of polycyclohexylene dimethylene terephthalate (PCTG) polymerized at a molar ratio of 2: 2, and the refractive index of 2% by weight of a phosphate-containing heat stabilizer was 1.58. The core layer thickness is 120 占 퐉, and the skin layer thickness is 90 占 퐉 at the top and bottom.

(B) Preparation of coating liquid

To prepare the coating solution, 43 wt% of urethane binder and 12 wt% of acrylic bead particles having an average particle diameter of 20 μm were added to 45 wt% of propylene glycolmotomethyl ether (PGME), and the mixture was stirred at 1500 rpm for 15 minutes in an agitator to prepare a coating solution Respectively.

(C) Reflective Polarizing Film Coating Step

The polarizing film thus prepared was coated with the above coating liquid using a 150 mesh microgravure roll to cover the upper surface of the skin layer above the core layer and the lower surface of the skin layer below the core layer. The coated polarizing film was dried at 80 DEG C for 1 minute and irradiated with ultraviolet (UV) at 80 Kw for 10 seconds to cure. The thickness of the binder layer of the produced reflection type polarizing film was 120 탆.

≪ Examples 2 to 16 >

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

division Composition and content of coating liquid Addition and content of additives solvent
(Type / weight%) bookbinder
(Type / weight%) Bead particle
(Type / average particle diameter (占 퐉)
/weight%) Defoamer
(Type / weight%) Dispersant
(weight%) Example 1 PGME ^{1 )} / 45 Urethane binder / 43 Acrylic bead particles / 20/12 - - Example 2 PGME / 37.5 Urethane binder / 37.5 Acrylic bead particles / 20/25 - - Example 3 PGME / 50 Urethane binder / 48 Acrylic bead particles / 20/2 - - Example 4 PGME / 45 Acrylic binders / 43 Acrylic bead particles / 20/12 - - Example 5 PGME / 45 Urethane binder / 43 Methacrylic acid / 20/12 - - Example 6 PGME / 45 Urethane binder / 43 Acrylic bead particles / 0.5/12 - - Example 7 PGME / 45 Urethane binder / 43 Acrylic bead particles / 55/12 - - Example 8 PGME / 25 Urethane binder / 50 Acrylic bead particles / 20/25 - - Example 9 PGME / 60 Urethane binder / 35 Acrylic bead particles / 20/5 - - Example 10 PGME / 55 Urethane binder / 25 Acrylic bead particles / 20/20 - - Example 11 PGME / 35 Urethane binder / 60 Acrylic bead particles / 20/5 - - Example 12 PGME / 51.5 Urethane binder / 48 Acrylic bead particles / 20/0.5 - - Example 13 PGME / 35 Urethane binder / 35 Acrylic bead particles / 20/30 - - Example 14 PGME / 43 Urethane binder / 43 Acrylic bead particles / 20/12 Octyl alcohol / 1 Alkylalkoxysilane / 1 Example 15 PGME / 44 Urethane binder / 43 Acrylic bead particles / 20/12 Octyl alcohol / 1 - Example 16 PGME / 44 Urethane binder / 43 Acrylic bead particles / 20/12 - Alkylalkoxysilane / 1 1) PGME represents propylene glycol monomethyl ether.

≪ Comparative Example 1 &

The coating solution was prepared in the same manner as in Example 1 except that 15% by weight of methyl ethyl ketone (MEK), 7.5% by weight of toluene and 15% by weight of ethyl acetate, 37.5% by weight of urethane binder and 25% .

≪ Comparative Example 2 &

The coating solution was prepared in the same manner as in Example 1 except that 20% by weight of methyl ethyl ketone (MEK), 10% by weight of toluene and 20% by weight of ethyl acetate, 48% by weight of urethane binder and 2% .

≪ Comparative Example 3 &

1% by weight of octyl alcohol as a defoaming agent, 1% by weight of alkylalkoxysilane as a dispersing agent, 14% by weight of methyl ethyl ketone (MEK) as a solvent, 7.5% by weight of toluene and 14% by weight of ethyl acetate, The coating liquid was prepared in the same manner as in Example 1 except that the coating liquid was prepared in terms of weight%.

≪ Comparative Example 4 &

1% by weight of octyl alcohol as a defoaming agent, 1% by weight of alkylalkoxysilane as a dispersing agent, 19% by weight of methyl ethyl ketone (MEK) as a solvent, 19% by weight of toluene and 19% by weight of ethyl acetate, 48% by weight of a urethane binder, The coating liquid was prepared in the same manner as in Example 1 except that the coating liquid was prepared in terms of weight%.

<Experimental Example>

remind Example  1 to 16 and Comparative Example  The following items 1 to 5 were evaluated for the reflective polarizing film coated through the coating solution of 1 to 2, and it is shown in Table 2.

1. Degree of occurrence of coating unevenness

In order to measure the degree of occurrence of coating unevenness (staining) of the reflective polarizing film coated through the coating liquids of Examples 1 to 16 and Comparative Examples 1 and 2, And the degree of occurrence of coating unevenness (stain) was measured with naked eyes. (X - very high, △ - high, ◇ - average, ○ - almost none, ◎ - none)

2. Wettability

In order to measure the wettability of the reflective polarizing film coated through the coating liquids of Examples 1 to 16 and Comparative Examples 1 and 2, for each reflective polarizing film, for 96 hours in a constant-temperature chamber at a temperature of 85 ° C and a relative humidity of 85% And allowed to stand at room temperature for 1 hour, and then the wettability of the reflective polarizing film was evaluated.

3. Leveling (Leveling)

The leveling was measured on the reflective polarizing film coated through the coating liquids of Examples 1 to 16 and Comparative Examples 1 and 2.

4. Uncoated

In order to measure the dispersing power of the coating liquids of Examples 1 to 16 and Comparative Examples 1 and 2, the number of uncoated portions of the reflective polarizing film coated through each coating liquid was measured to measure the dispersing power.

5. Micro Gravure  Pollution measurement

In order to measure the degree of contamination of the microgravure fabricating the reflective polarizing film coated through the coating liquids of Examples 1 to 16 and Comparative Examples 1 and 2, the driving distance required to clean the contaminated microgravure was measured, Were measured.

6. Attachment

To measure the adhesion of the skin layer and the coating layer of the reflective polarizing film coated through the coating solutions of Examples 1 to 16 and Comparative Examples 1 and 2, the adhesive strength of the coating layer was measured at 25 ° C using a push-pull gage at a rate of 1 mm / min (X - very bad, △ - poor, ◇ - average, ○ - good, ◎ - very good)

division Uncoated
(stain) Wettability
(ea / m ² ) Leveling Uncoated
(ea / m ² ) Micro
Gravure
Cleaning (m / s) Attachment Example 1 ◎ 0.14 Great 0.015 4500 ◎ Example 2 ◎ 0.1 Great 0.01 4000 ◎ Example 3 ◎ 0.2 Great 0.02 5000 ◎ Example 4 ○ 0.13 usually 0.014 5000 ◇ Example 5 ◇ 0.4 Good 0.04 4500 ◎ Example 6 ◇ 0.15 Good 0.015 4500 ○ Example 7 ◇ 0.6 usually 0.014 4500 ◇ Example 8 ○ 0.08 usually 0.008 4500 ◇ Example 9 ◇ 0.14 usually 0.016 4500 ◇ Example 10 ◇ 0.13 usually 0.013 4500 △ Example 11 ○ 0.17 Good 0.014 4500 △ Example 12 ○ 0.16 Good 0.15 4500 ○ Example 13 ◇ 0.12 usually 0.015 4500 ◇ Example 14 ◎ 0.13 Great 0.013 4500 ◎ Example 15 ◎ 0.14 Great 0.014 4500 ◎ Example 16 ◎ 0.13 Great 0.013 4500 ◎ Comparative Example 1 × 0.4 Good 0.05 1500 ◇ Comparative Example 2 × 0.7 usually 0.12 2000 ◇ Comparative Example 3 △ 0.2 Good 0.02 2000 ○ Comparative Example 4 △ 0.22 Good 0.026 2000 ○

As can be seen from the above Table 2, Examples 1 to 3, which satisfy both the composition and the content of the coating solution of the present invention, are coated unevenly in comparison with Examples 4 to 13 and Comparative Examples 1 and 2, ) Was not generated, the wettability was low, and the leveling, dispersing ability, adhesion and prevention of contamination of microgravity were all excellent. In addition, Examples 1 to 3, in which additives were not added, exhibited a level of effect comparable to Examples 14 to 16 including antifoaming agents and / or dispersants. By using propylene glycol monomethyl ether (PGME) as a solvent without using an additive, coating unevenness (dirt) was not generated, wettability was low, leveling, dispersing ability and adhesion were excellent, and microglia contamination It is possible to achieve the effect to be prevented.

Also, Example 1 using a urethane binder as a binder did not cause coating unevenness (stain) as compared with Example 4 using an acrylic binder as a binder, and was excellent in adhesion and prevention of contamination with microgravity. It can be seen that it is more advantageous to use the urethane binder as the binder.

Further, Example 1 using acrylic bead particles as bead particles did not cause coating unevenness (stain) as compared with Example 5 using methacrylic acid as bead particles, had low wettability, and was excellent in leveling and dispersing ability. It can be seen that it is more advantageous to use acrylic bead particles as the bead particles.

Further, in Example 1 using acrylic bead particles having an average particle diameter of 20 占 퐉, coating unevenness (stain) did not occur and wettability was lower than that in Example 6 using bead particles having an average particle diameter of 0.5 占 퐉, The coating film was not stained, the wettability was low, and the leveling and adhesion were excellent, compared with Example 7 using bead particles having an average particle diameter of 55 μm. As a result, it can be seen that it is more advantageous to use acrylic bead particles having an average particle diameter of 1 to 50 μm.

Further, Example 1 using 45 wt% of propylene glycol monomethyl ether (PGME) did not cause coating unevenness (stain) as compared with Example 8 using 25 wt% of propylene glycol monomethyl ether (PGME) And was superior in leveling, dispersing ability, and adhesion as compared with Example 9 in which propylene glycol monomethyl ether (PGME) was used in an amount of 60% by weight. It is thus understood that it is advantageous to use a coating liquid containing 35 to 55% by weight of propylene glycol monomethyl ether (PGME).

Example 1 using 43% by weight of a urethane binder showed no coating irregularity and excellent leveling and adhesion as compared with Example 10 using 25% by weight of a urethane binder, and 60% by weight of a urethane binder, Coating unevenness (dirt) was not generated, wettability was low, and leveling and adhesion were superior to those in Example 11. It can be seen that it is advantageous to use a coating liquid containing 35 to 50% by weight of the urethane binder.

In addition, Example 1 using 12 wt% of acrylic bead particles showed no coating unevenness, lower wettability, leveling, dispersibility, and adhesion as compared with Example 12 using 0.5 wt% of acrylic bead particles And no coating unevenness (stain) was generated as compared with Example 13 using 30 wt% of acrylic bead particles, and the leveling and adhesion were excellent. It can be seen from this that it is advantageous to use a coating liquid containing 1 to 25% by weight of acrylic bead particles.

Further, as can be seen from Table 2, Examples 1 to 3 in which additives are not used show that Example 14 containing both a defoaming agent and a dispersing agent, Example 15 including a defoaming agent alone, (Wetting property), leveling, dispersibility, adhesion and microgravure contamination, which were not significantly different from those in Example 16, and the solvent was dissolved in propylene glycol monomethyl ether (PGME) It is possible to achieve an effect of preventing coating contamination (unevenness), low wettability, excellent leveling, dispersing ability and adhesion, and at the same time, preventing contamination of micrograye, It can be seen that it is excellent.

Example 2 using a coating liquid containing 37.5 wt% of propylene glycol monomethyl ether (PGME) as a solvent contained 15 wt% of methyl ethyl ketone (MEK), 7.5 wt% of toluene and 15 wt% of ethyl acetate (No staining), low wettability, and excellent leveling, dispersing ability, adhesion and microgravure stain prevention as compared with Comparative Example 1 using the coating solution. Example 3 using a coating solution containing 50% by weight of propylene glycol monomethyl ether (PGME) as a solvent contained 20% by weight of methyl ethyl ketone (MEK), 10% by weight of toluene and 20% by weight of ethyl acetate (No staining), low wettability, and excellent leveling, dispersing ability, adhesion, and microgravure contamination, as compared with Comparative Example 2 using the coating solution. As a result, it was found that the use of propylene glycol monomethyl ether (PGME) as a solvent was free from occurrence of coating unevenness, low wettability, and further advantageous in leveling, dispersibility, adhesion and microgravure contamination prevention . In addition, in Comparative Examples 1 and 2, it was confirmed that the generation of unevenness was remarkably increased because the coating liquid dissolves the polycarbonate skin layer.

Example 1, which did not contain a defoaming agent and a dispersing agent but used propylene glycol monomethyl ether as a solvent in an amount of 45 wt%, contained 14 wt% of methyl ethyl ketone (MEK), 7.5 wt% of toluene, and ethyl (No staining), low wettability, and excellent leveling, dispersing ability, adhesion and microgravure stain prevention as compared with Comparative Example 3 using a coating liquid containing 14% by weight of acetate. Example 3, which did not contain a defoaming agent and a dispersing agent but used propylene glycol monomethyl ether as a solvent in an amount of 50 wt%, contained defoaming agent and dispersant and contained 19 wt% of methyl ethyl ketone (MEK), 10 wt% of toluene and ethyl (No staining), low wettability, and excellent leveling, dispersing ability, adhesion and microgravure stain prevention, as compared with Comparative Example 3 using a coating liquid containing 19 wt% of acetate. As a result, the use of propylene glycol monomethyl ether (PGME) as a solvent shows no occurrence of coating unevenness, low wettability, and is more advantageous in leveling, dispersibility, adhesion and prevention of microgravure contamination. In Comparative Examples 3 and 4, wetting, leveling, dispersing ability and adhesion were not adversely affected because additives were used. However, it was confirmed that the generation of unevenness was significantly increased because the coating liquid dissolved the polycarbonate skin layer due to the solvent component Could.

1 to 4: Substrate 5 to 7: Adhesive layer
8: substrate 9, 10: skin layer
11, 12: adhesive layer 20: reflective polarizer
21: substrate 22: birefringent polymer
100: reflection type polarizing film 110: core layer
120, 140: Skin layer 130, 150: Coating layer
131: Binder 132: Bead particles
200: Base material 201 to 206: Dispersion
207 Skin layer 270 Frame
280: reflector 290: cold cathode fluorescent lamp
300: mold frame 310: liquid crystal display panel
320: optical film 321: diffuser plate
322: light diffusion film 323: prism film
324: Reflective polarizer 325: Absorbing polarizing film

Claims (17)

A reflective polarizing film comprising a core layer and a polycarbonate skin layer formed on at least one side of a core layer, wherein the polycarbonate skin layer is coated with propylene glycol monomethyl ether (PGME), a binder Type polarizing film coating composition. The method according to claim 1,
Wherein the binder is a urethane binder. The method according to claim 1,
Wherein the bead particle is an acrylic bead particle. The method of claim 3,
Wherein the acrylic bead particles have an average particle size of 1 to 50 占 퐉. The method of claim 3,
Wherein the acrylic bead particles have the same or different particle diameters. The method according to claim 1,
Wherein the coating liquid composition comprises 35 to 55 wt% of propylene glycol monomethyl ether, 35 to 50 wt% of the binder, and 1 to 25 wt% of the bead particles. The method according to claim 1,
Wherein the coating liquid composition does not contain any one or more additives selected from the group consisting of a defoaming agent and a dispersing agent. The method of claim 7, wherein
Wherein the coating liquid composition does not contain both a defoaming agent and a dispersing agent. (1) preparing a reflective polarizer comprising a core layer and a polycarbonate skin layer formed on at least one side of the core layer; And
(2) coating at least one surface of the polycarbonate skin layer with the coating solution of any one of the items (1) to (7). 10. The method of claim 9,
(3) drying the coated polycarbonate skin layer at 70 to 90 DEG C for 0.5 to 2 minutes. 11. The method of claim 10,
(4) irradiating the dried polycarbonate skin layer with ultraviolet light (UV) at 70 to 90 Kw for 5 to 15 seconds. A core layer;
A polycarbonate skin layer formed on at least one side of the core layer; And
And a coating layer comprising bead particles formed on at least one side of the polycarbonate skin layer, wherein the coating layer does not contain a defoaming agent or a dispersant. 13. The method of claim 12,
Wherein the coating layer comprises a binder layer,
Wherein the thickness of the binder layer is 10 to 150 占 퐉. 13. The method of claim 12,
Wherein the bead particles are acrylic bead particles. The method of claim 12, wherein
Wherein the coating layer does not contain both a defoaming agent and a dispersing agent. 13. The method of claim 12,
Wherein the core layer and the polycarbonate skin layer are integrally formed. 13. The method of claim 12,
Wherein the core layer has a second component dispersed inside the first component.

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