KR20120021184A - Composition for polarizing film, polarizing film, method of manufacturing the same, and liquid crystal display provided with the polarizing film - Google Patents

Abstract

PURPOSE: A composite material for a polarizing film, the polarizing film, a manufacturing method thereof, and a liquid crystal display apparatus including the same are provided to reduce the thickness of a display apparatus. CONSTITUTION: A liquid crystal display apparatus comprises a liquid crystal display panel(10) and a polarizing film(20). The polarizing film is located on the upper part and the lower part of the liquid crystal display panel. The liquid crystal display panel comprises a first display panel(100), a second display panel(200), and a liquid crystal layer(300). The liquid crystal layer is arranged between the first display panel and the second display panel. The major axis of a liquid crystal molecule is arranged approximately parallel to the surface of the first display panel and the second display panel without an electric field when the liquid crystal molecule has positive dielectric permittivity anisotropy. The major axis of the liquid crystal molecule is arranged almost vertical to the surface of the first display panel and the second display panel when the electric field is applied.

Description

The composition for polarizing films, a polarizing film, the manufacturing method, and the liquid crystal display device provided with the said polarizing film TECHNICAL FIELD

It relates to the liquid crystal display device provided with the composition for polarizing films, a polarizing film, its manufacturing method, and the said polarizing film.

Liquid crystal displays (LCDs) are one of the flat panel displays that are widely used at present. The liquid crystal display includes two display panels on which an electric field generating electrode is formed and a liquid crystal layer interposed therebetween, and the transmittance of light changes as the liquid crystal rotates due to the electric field formed between the electric field generating electrodes. The image is displayed according to the change.

The liquid crystal display device includes a polarizing plate attached to an outer side of the display panel. The polarizing plate transmits only light oscillating in a specific direction and absorbs or reflects other light to control the direction of light incident on the display panel or the light exiting from the display panel.

The polarizing plate generally includes a polarizer and a protective layer for protecting the same. For example, polyvinyl alcohol (PVA) may be used as the polarizer, and triacetyl cellulose (TAC) may be used as the protective layer.

However, the polarizer including the polarizer and the protective layer may not only have a complicated process and a high production cost, but also have a thicker polarizer, which may affect the thickness of the display device.

One embodiment provides a composition for a polarizing film that can simplify a process, lower a production cost, and implement a thin display device.

Another embodiment provides a polarizing film including the composition for the polarizing film and uniaxially stretched.

Another embodiment provides a method of manufacturing the polarizing film.

Another embodiment provides a liquid crystal display device including the polarizing film.

According to one embodiment, a polyolefin resin comprising a polypropylene and a polyethylene-polypropylene copolymer; And it provides the composition for polarizing films containing a dichroic dye.

According to another embodiment, a polyolefin resin including a polypropylene and a polyethylene-polypropylene copolymer; And a dichroic dye, and provide a uniaxially stretched polarizing film.

According to yet another embodiment, a polyolefin resin including a polypropylene and a polyethylene-polypropylene copolymer; And mixing and melting the dichroic dye, preparing the sheet by pressing the molten mixture into a mold, and uniaxially stretching the sheet.

According to another embodiment, a first display panel and a second display panel facing each other, a liquid crystal layer positioned between the first display panel and the second display panel, and an outer side of at least one of the first display panel and the second display panel. A polarizing film comprising a polyolefin resin comprising a polypropylene and a polyethylene-polypropylene copolymer; And a dichroic dye and uniaxially stretched.

The polypropylene may have a melt flow index (MFI) of about 0.1 g / 10 min to about 5 g / 10 min.

The polyethylene-polypropylene copolymer may include about 1% by weight to about 50% by weight of ethylene groups based on the total content of the copolymer.

The polyethylene-polypropylene copolymer may have a melt flow index (MFI) of about 5 g / 10 min to about 15 g / 10 min.

The polyolefin resin may include the polypropylene and the polyethylene-polypropylene copolymer in a weight ratio of about 1: 9 to about 9: 1.

The polyolefin resin may have a melt flow index (MFI) of about 1 g / 10 min to about 15 g / 10 min.

The polyolefin resin may have a haze of about 5% or less and may have a crystallinity of about 50% or less.

The dichroic dye may have a dichroic ratio of about 1.5 to about 14.

The dichroic dye may have an absorbance of about 0.38 or less in light of all wavelengths of 380 nm to 780 nm.

The dichroic dye may be included in an amount of about 0.05 parts by weight to about 2 parts by weight based on 100 parts by weight of the polyolefin resin.

The difference between the solubility parameter of the polyolefin resin and the solubility parameter of the dichroic dye may be about 10 or less.

The polarizing film may have a total light transmittance of about 20% or more in the wavelength range of the visible light region (eg, about 380 nm to about 780 nm).

The polarizing film may have an optical polarization efficiency of about 85% or more in the wavelength range of the visible light region (eg, about 380 nm to about 780 nm).

The polarizing film may have a thickness of about 25 μm to about 150 μm.

In the manufacturing method, uniaxially stretching the sheet may be stretched at about 300% to about 1000% elongation.

A polarizing film composition, a polarizing film manufactured using the same, and a display device including the same may be provided to simplify the process, lower the production cost, and implement a thin display device.

1 is a cross-sectional view illustrating a liquid crystal display device according to an embodiment.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

First, a composition for a polarizing film and a polarizing film according to an embodiment are described.

According to one embodiment, a composition for a polarizing film includes a polyolefin resin including polypropylene and a polyethylene-polypropylene copolymer; And dichroic dyes.

In addition, the polarizing film according to another embodiment includes the composition for the polarizing film and is uniaxially stretched.

The polypropylene and the polyethylene-polypropylene copolymer may be simple blended.

The polyolefin resin is excellent in moisture resistance as a hydrophobic resin.

The polypropylene has excellent mechanical strength, and the polyethylene has excellent haze characteristics.

The polyolefin resin may include polypropylene and a polyethylene-polypropylene copolymer, thereby improving haze characteristics by preventing crystallization of polypropylene while having excellent mechanical strength. In addition, the polyolefin resin may prevent the phase separation of polyethylene by including the polyethylene in the form of a copolymer with the polypropylene.

The polypropylene may have a melt flow index (MFI) of about 0.1 g / 10 min to about 5 g / 10 min. Here, the melt flow index (MFI) represents the amount of the polymer flowing in the molten state per 10 minutes, and is related to the viscosity of the polymer in the molten state. That is, the smaller the melt flow index (MFI), the higher the viscosity of the polymer, and the larger the melt flow index (MFI), the lower the viscosity of the polymer. When the melt flow index (MFI) of the polypropylene is in the above range, it is possible to effectively improve the workability, it can effectively improve the physical properties of the final product. Specifically, the polypropylene may have a melt flow index (MFI) of about 0.5 g / 10 min to about 5 g / 10 min.

The polyethylene-polypropylene copolymer may include about 1% by weight to about 50% by weight of ethylene groups based on the total content of the copolymer. When the content of the ethylene group in the polyethylene-polypropylene copolymer is within the above range, it is possible to effectively prevent or alleviate the phase separation of the polypropylene and the polyethylene-polypropylene copolymer. In addition, it is possible to increase the elongation when stretching while having excellent light transmittance and orientation, thereby realizing improved polarization characteristics. Specifically, the polyethylene-polypropylene copolymer may include about 1 wt% to about 25 wt% of ethylene groups based on the total content of the copolymer.

The polyethylene-polypropylene copolymer may have a melt flow index (MFI) of 5 g / 10 min to 15 g / 10 min. When the melt flow index (MFI) of the polyethylene-polypropylene copolymer is in the above range, it is possible to effectively improve the workability, it is possible to effectively improve the physical properties of the final product. Specifically, the polyethylene-polypropylene copolymer may have a melt flow index (MFI) of about 10 g / 10 min to about 15 g / 10 min.

The polyolefin resin may include the polypropylene and the polyethylene-polypropylene copolymer in a weight ratio of about 1: 9 to about 9: 1. When the polypropylene and the polyethylene-polypropylene copolymer are included in the above range, it is possible to effectively improve the haze characteristics by preventing crystallization of the polypropylene while having excellent mechanical strength. Specifically, the polyolefin resin may include the polypropylene and the polyethylene-polypropylene copolymer in a weight ratio of about 4: 6 to about 6: 4, more specifically about 5: 5.

The polyolefin resin may have a melt flow index (MFI) of about 1 g / 10 min to about 15 g / 10 min. When the melt flow index (MFI) of the polyolefin resin is within the above range, excessive crystals are not formed in the resin, thereby ensuring excellent light transmittance and having a viscosity suitable for manufacturing into a film, thereby improving workability. . Specifically, the polyolefin resin may have a melt flow index (MFI) of about 5 g / 10 min to about 15 g / 10 min.

The polyolefin resin may have a haze of about 5% or less. When the haze of the polyolefin resin is within the above range, the transmittance may increase to have excellent optical properties. Specifically, the polyolefin resin may have a haze of about 2% or less, and more specifically, about 0.5% to about 2% haze.

The polyolefin resin may have a crystallinity of about 50% or less. When the crystallinity degree of the said polyolefin resin is in the said range, haze can be lowered and the outstanding optical characteristic can be achieved. Specifically, the polyolefin resin may have a crystallinity of about 30% to about 50%. In some embodiments, the polyolefin resin can have a crystallinity of about 45% or less.

The dichroic dye is a material having a property of transmitting a polarization orthogonal component of one of two polarization orthogonal components to a predetermined wavelength region.

The dichroic dye may be dispersed in the polyolefin resin and elongated in the uniaxial direction and arranged in one direction.

Such dichroic dyes include, for example, azo compounds, anthraquinone compounds, phthalocyanine compounds, azomethine compounds, indigoid or thioindigoid compounds, and merocyanine compounds. Compound, 1,3-bis dicyano methylene indan (1,3-bis (dicyanomethylene) indan) compound, azulene compound, quinophthalonic compound, triphenodioxazine (triphenodioxazine ) -Based compound, indolo [2,3, b] quinoxaline-based compound, imidazo [1,2-b] -1,2,4 triazine (imidazo [1] , 2-b] -1,2,4 triazines) compound, tetrazine (tetrazines) compound, benzo (benzo) compound, naphtoquinones compound, or a combination thereof The compound can be mentioned.

The dichroic dye may have a dichroic ratio of about 1.5 to about 14. Here, the dichroic ratio is a value obtained by dividing the polarization absorption in the direction parallel to the axis of the polymer by the polarization absorption in the vertical direction thereof, and may indicate the degree in which the dichroic dyes are arranged side by side in one direction.

In this embodiment, the dichroic dye may have a dichroic ratio of about 1.5 to about 14, and having a dichroic ratio in the above range, the dichroic dye may have sufficient compatibility with the polyolefin. Specifically, the dichroic ratio of the dichroic dye may be about 1.5 to about 10.

By having a dichroic ratio in the above range it is possible to melt kneading with the polymer and to induce the orientation of the dye according to the orientation of the polymer chain can improve the polarization characteristics.

The dichroic dye may have an absorbance of about 0.38 or less in light of all wavelengths from about 380 nm to about 780 nm. When the absorbance of the dichroic dye is in the above range, it may exhibit excellent color reproducibility. Specifically, the dichroic dye may have an absorbance of about 0.31 to about 0.37 in light of all wavelengths of about 380 nm to about 780 nm.

The dichroic dye may be included in an amount of about 0.05 parts by weight to about 2 parts by weight based on 100 parts by weight of the polyolefin resin. By including the dichroic dye in the above range can exhibit sufficient polarization characteristics. Specifically, the dichroic dye may be included in an amount of about 0.05 part by weight to about 1.5 parts by weight, and more specifically about 0.05 part by weight to about 1 part by weight based on 100 parts by weight of the polyolefin resin.

The difference between the solubility parameter of the polyolefin resin and the solubility parameter of the dichroic dye may be about 10 or less. In this case, the polyolefin and the dichroic dye may have excellent compatibility or compatibility. Specifically, the difference between the solubility parameter of the polyolefin resin and the solubility parameter of the dichroic dye may be about 5 or less.

The polarizing film may have a total transmittance of about 20% or more in the visible light (about 380 nm to about 780 nm) wavelength range. When the light transmittance of the polarizing film is within the above range, it is possible to reproduce a clear image. Specifically, the polarizing film may have a total light transmittance of about 30% or more, specifically about 30% to about 50% in light of about 380 nm to about 780 nm.

The polarizing film may have a polarizing efficiency (PE) of about 85% or more in the visible light (about 380 nm to about 780 nm) wavelength range. When the polarization efficiency of the polarizing film is within the above range, it is possible to reproduce a clear image. Specifically, the polarizing film may have a polarization efficiency of about 90% to about 99% in light having a wavelength of about 380 nm to about 780 nm.

By having sufficient light transmittance and polarization efficiency as mentioned above, it can apply to a liquid crystal display device etc. efficiently.

The polarizing film may have a thickness of about 25 μm to about 150 μm.

Hereinafter, the manufacturing method of the said polarizing film is demonstrated.

The manufacturing method of the said polarizing film is a polyolefin resin containing the said composition for polarizing films, specifically a polypropylene and a polyethylene-polypropylene copolymer; And mixing and melting the dichroic dye, putting the molten mixture into a mold and pressing to prepare a sheet, and uniaxially stretching the sheet.

Unless otherwise described below, the composition for the polarizing film, polypropylene, polyethylene-polypropylene copolymer, polyolefin resin, dichroic dye, and polarizing film are as described above.

In the mixing and melting of the polyolefin resin and the dichroic dye, the dichroic dye may be mixed in an amount of about 0.05 part by weight to about 2 parts by weight based on 100 parts by weight of the polyolefin resin.

The step of preparing a sheet of the molten mixture may be formed by pressing with a high pressure press at a relatively high temperature of about 200 ℃ to about 230 ℃, or by ejecting to a chill roll through a T-die (T-die) It may be, but is not limited thereto.

Uniaxially stretching the sheet may be performed at about 110 ° C to about 150 ° C.

In addition, the uniaxial stretching of the sheet may be performed at an elongation of about 300% to about 1000%, specifically, at an elongation of about 400% to about 1000%. The elongation here refers to the ratio of the length before the stretching and the length after the stretching of the sheet, and means the extent that the sheet is stretched after uniaxial stretching.

Hereinafter, a liquid crystal display including the polarizing film will be described with reference to FIG. 1.

1 is a cross-sectional view illustrating a liquid crystal display device according to an embodiment.

Referring to FIG. 1, the liquid crystal display includes a liquid crystal display panel 10 and a polarizing film 20 positioned below and above the liquid crystal display panel 10.

The liquid crystal display panel 10 may be a twisted nematic (TN) mode or a patterned vertical alignment (PVA) mode.

The liquid crystal display panel 10 includes a first display panel 100, a second display panel 200, and a liquid crystal layer 300 interposed between the first display panel 100 and the second display panel 200.

The first display panel 100 may include, for example, a thin film transistor (not shown) formed on a substrate (not shown) and a first field generating electrode (not shown) connected thereto. 200 may include, for example, a color filter (not shown) and a second field generating electrode (not shown) formed over a substrate (not shown).

The liquid crystal layer 300 may include a plurality of liquid crystal molecules. The liquid crystal molecules may have positive or negative dielectric anisotropy. When the liquid crystal molecules have positive dielectric anisotropy, their long axes are oriented substantially parallel to the surface of the first display panel 100 and the second display panel 200 in the absence of an electric field, and the long axes of the liquid crystal molecules are applied in the state where an electric field is applied. The display panel 100 may be aligned to be substantially perpendicular to the surfaces of the first display panel 100 and the second display panel 200. On the contrary, when the liquid crystal molecules have negative dielectric anisotropy, in the absence of the electric field, the major axis thereof is oriented almost perpendicular to the surfaces of the first display panel 100 and the second display panel 200, and in the state where the electric field is applied. The long axis may be oriented substantially parallel to the surfaces of the first display panel 100 and the second display panel 200.

The polarizing film 20 is positioned outside the liquid crystal display panel 10 and is illustrated as being formed on the lower and upper portions of the liquid crystal display panel 10, but the present invention is not limited thereto, and the lower and upper portions of the liquid crystal display panel 10 are not limited thereto. It may be formed only in either.

As described above, the polarizing film 20 includes a polyolefin resin including polypropylene and a polyethylene-polypropylene copolymer; And a uniaxially oriented film containing a dichroic dye, and consists of a single layer without a separate protective layer.

Unless otherwise described below, the descriptions of the polypropylene, polyethylene-polypropylene copolymer, polyolefin resin, dichroic dye, and polarizing film are as described above.

Since the polyolefin resin has hydrophobicity, not only has sufficient moisture resistance, but also excellent mechanical strength, and thus it is not necessary to provide a separate protective layer. Therefore, it is not necessary to provide an expensive protective layer such as triacetyl cellulose (TAC), thereby lowering the manufacturing cost and forming a thin overall thickness of the polarizing film.

In the above, only the example in which the polarizing film is applied to the liquid crystal display device has been described.

Example

The present invention will be described in more detail with reference to the following Examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

Example  1: Preparation of polarizing film composition and polarizing film

100 parts by weight of polyolefin resin containing polypropylene resin (HU300, made by Samsung Total) and polyethylene-polypropylene copolymer resin (polyethylene ratio: 10% by weight, RJ565, made by Samsung Total) at 5: 5 (weight ratio), and CIBA -BLACK Dichroic dye 0.5 part by weight is mixed to prepare a composition for a polarizing film. The composition for polarizing film is then melted at a temperature of about 230 ° C. The molten mixture is then placed in a sheet-like mold and pressed with a roller to produce a film. The film is then uniaxially stretched at 115 ° C. Thereby, a polarizing film is manufactured. The thickness of the produced polarizing film is 50 micrometers.

Example  2: Production of Polarizing Film Composition and Polarizing Film

A composition for polarizing films and a polarizing film were prepared in the same manner as in Example 1 except that 0.25 parts by weight of CIBA-BLACK dichroic dye was mixed. The thickness of the produced polarizing film is 50 micrometers.

Example  3: Production of polarizing film composition and polarizing film

Except for using polyolefin resin containing 4: 6 (weight ratio) of polypropylene resin (HU300, made by Samsung Total) and polyethylene-polypropylene copolymer resin (polyethylene ratio: 10% by weight, RJ565, made by Samsung Total) , The composition for a polarizing film and a polarizing film are manufactured by the same method as Example 1. The thickness of the produced polarizing film is 50 micrometers.

Example  4: Production of composition for polarizing film and polarizing film

Except for using polyolefin resin containing polypropylene resin (HU300, made by Samsung Total) and polyethylene-polypropylene copolymer resin (polyethylene ratio: 10% by weight, RJ565, made by Samsung Total) at 6: 4 (weight ratio). , The composition for a polarizing film and a polarizing film are manufactured by the same method as Example 1. The thickness of the produced polarizing film is 50 micrometers.

Comparative example  1: Preparation of polarizing film composition and polarizing film

100 parts by weight of polypropylene resin (HU300, Samsung Total Co., Ltd.) and 0.5 parts by weight of CIBA-BLACK dichroic dye are mixed to prepare a composition for a polarizing film. The composition for polarizing film is then melted at a temperature of about 230 ° C. The molten mixture is then placed in a sheet-like mold and pressed with a roller to produce a film. The film is then uniaxially stretched at 115 ° C. Thereby, a polarizing film is manufactured. The thickness of the produced polarizing film is 50 micrometers.

Comparative example  2: Production of Polarizing Film Composition and Polarizing Film

A polarizing film composition and a polarizing film were prepared in the same manner as in Comparative Example 1 except that 0.25 parts by weight of CIBA-BLACK dichroic dye was mixed with 100 parts by weight of polypropylene resin (HU300, manufactured by Samsung Total). The thickness of the produced polarizing film is 50 micrometers.

Comparative example  3: Production of polarizing film composition and polarizing film

Polyethylene-polypropylene copolymer resin (polyethylene ratio: 10% by weight, RJ565, manufactured by Samsung Total) was used instead of polypropylene resin, and 0.5 parts by weight of CIBA-BLACK dichroic dye based on 100 parts by weight of polyethylene-polypropylene copolymer resin. Except having mixed, the composition for polarizing films and a polarizing film are manufactured by the method similar to the comparative example 1.

Comparative example  4: Production of composition for polarizing film and polarizing film

A polyethylene-polypropylene copolymer resin (polyethylene ratio: 10% by weight, RJ565, manufactured by Samsung Total) was used in place of the polypropylene resin, and 0.25 parts by weight of the CIBA-BLACK dichroic dye based on 100 parts by weight of the polyethylene-polypropylene copolymer resin. Except having mixed, the composition for polarizing films and a polarizing film are manufactured by the method similar to the comparative example 1.

Test Example  One: Haze  Measure

The haze of the resin used in Examples 1 to 4 and Comparative Examples 1 to 4 was measured using a spectrophotometer device (KONICA MINOLTA, CM-3600d) to measure the haze obtained by passing through the sample. At this time, the result at the time of making the elongation 1000% is shown in Table 1 below.

Test Example  2: crystallinity measurement

The crystallinity of the resins used in Examples 1 to 4 and Comparative Examples 1 to 4 is measured using a Dynamic Scanning Calorimetry instrument (Perkin-Elmar, 8500). Here, the degree of crystallinity is defined as the value obtained by dividing the integral value of the exothermic peak generated by heating and cooling of the film sample obtained by stretching by the integral value of the exothermic peak that appears when the crystallinity is 100%. At this time, the result at the time of making the elongation 1000% is shown in Table 1 below.

Haze (%) Crystallinity (%) Example 1 (elongation: 1000%) 1.58 42.5 Example 3 (elongation: 1000%) 1.70 41.0 Example 4 (elongation: 1000%) 1.72 44.0 Comparative Example 1 (Elongation: 1000%) 9.80 58.0 Comparative Example 3 (Elongation: 1000%) 5.40 55.0

As shown in Table 1, it can be seen that the haze and crystallinity characteristics of the resins used in Examples 1 to 4 are superior to the haze and crystallinity characteristics of the resins used in Comparative Examples 1 to 4.

Test Example  3: Dichroic ratio  And polarization efficiency measurements

Light transmittance in the wavelength range of the visible light region (eg, about 380 nm to about 780 nm) according to the elongation of the polarizing films according to Examples 1 to 4 and Comparative Examples 1 to 4, specifically, parallel to the transmission axis of the polarizing film The light transmittance of the polarizing film with respect to the incident light and the light transmittance of the polarizing film with respect to the light incident perpendicularly to the transmission axis of the polarizing film are measured using a UV-VIS Spectrophotometer (JASCO, V-7100).

Dichroic ratio (DR) and polarizing efficiency (PE) are obtained using the measured light transmittance.

The dichroic ratio is obtained by the following equation.

[Equation 1]

DR = Abs _？ / Abs _⊥

In the above equation (1)

DR is dichroic,

Abs _{? Is} the light absorbance of the polarizing film with respect to light incident in parallel with the transmission axis of the polarizing film,

Abs _⊥ is the light absorption of the polarizing film to the light incident perpendicular to the transmission axis of the polarizing film.

Polarization efficiency is calculated by the following equation.

[Equation 2]

PE (%) = [(T _？ -T _⊥ ) / (T _？ + T _⊥ )] ^1/2 ⅹ 100

In Equation 2,

PE is the polarization efficiency,

T _{? Is} the light transmittance of the polarizing film with respect to light incident in parallel with the transmission axis of the polarizing film,

T _⊥ is the light transmittance of the polarizing film with respect to light incident perpendicularly to the transmission axis of the polarizing film.

The results are shown in Table 2 below.

Elongation (%) 300 600 1000 Example  One T _？ (%) 1.54 1.67 3.44 T _⊥ (%) 0.0072 0.0082 0.012 Dichroic ratio 3.32 3.35 3.51 Polarization Efficiency (%) 99.53 99.51 99.65 Permeability (%) 29.95 33.20 36.73 Example  3 T _？ (%) 16.48 17.056 15.368 T _⊥ (%) 1.3 1.175 0.325 Dichroic ratio 2.41 2.43 2.82 Polarization Efficiency (%) 92.40 93.33 97.91 Permeability (%) 28.01 29.82 30.19 Example  4 T _？ (%) 22.66 23.452 21.131 T _⊥ (%) 0.884 0.799 0.221 Dichroic ratio 2.82 2.85 3.30 Polarization Efficiency (%) 96.17 96.65 98.96 Permeability (%) 29.31 30.82 32.67 Comparative example  One T _？ (%) 16.9 21.34 25.7 T _⊥ (%) 1.04 0.71 1.28 Dichroic ratio 2.56 3.2 3.21 Polarization Efficiency (%) 94.02 96.73 95.14 Permeability (%) 24.10 25.66 28.21 Comparative example  3 T _？ (%) 20.59 29.47 32.27 T _⊥ (%) 1.152 0.923 0.864 Dichroic ratio 2.56 3.2 3.21 Polarization Efficiency (%) 94.55 96.92 97.36 Permeability (%) 26.58 27.93 30.69 Example  2 T _？ (%) 22.66 23.45 21.13 T _⊥ (%) 0.68 0.61 0.17 Dichroic ratio 2.12 2.21 2.62 Polarization Efficiency (%) 97.06 97.43 99.20 Permeability (%) 25.16 29.69 32.63 Comparative example  2 T _？ (%) 22.53 20.7 16.84 T _⊥ (%) 1.73 1.68 1.22 Dichroic ratio 3.3 3.21 3.43 Polarization Efficiency (%) 92.59 92.19 93.00 Permeability (%) 22.95 23.20 26.73 Comparative example  4 T _？ (%) 23.66 21.74 17.68 T _⊥ (%) 1.095 0.96 0.33 Dichroic ratio 3.3 3.21 3.43 Polarization Efficiency (%) 95.47 95.68 98.15 Permeability (%) 24.82 24.44 28.71

As shown in Table 2, it is confirmed that the polarization efficiency and transmittance of the polarizing films prepared in Examples 1, 3 and 4 are superior or at least corresponding to the polarization efficiency and transmittance of the polarizing films prepared in Comparative Examples 1 and 3 Can be. In addition, it can be confirmed that the polarization efficiency and transmittance of the polarizing film prepared in Example 2 are superior to the polarization efficiency and transmittance of the polarizing films prepared in Comparative Examples 2 and 4.

These results are shown because the haze and crystallinity characteristics of the resins used in Examples 1 to 4 are superior to the haze and crystallinity characteristics of the resins used in Comparative Examples 1 to 4.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of the invention.

10: liquid crystal display panel, 20: polarizing film,
100: first display panel, 200: second display panel,
300: liquid crystal layer

Claims (18)

Polyolefin resins including polypropylene and polyethylene-polypropylene copolymers;
And dichroic dyes
Composition for a polarizing film comprising a.
The method of claim 1,
The polypropylene composition for a polarizing film having a melt flow index (MFI) of 0.1 g / 10min to 5 g / 10min.
The method of claim 1,
The polyethylene-polypropylene copolymer is a composition for a polarizing film comprising 1 to 50% by weight of an ethylene group based on the total content of the copolymer.
The method of claim 1,
The polyethylene-polypropylene copolymer is a composition for polarizing film having a melt flow index (MFI) of 5 g / 10min to 15 g / 10min.
The method of claim 1,
The polyolefin resin is a composition for a polarizing film comprising the polypropylene and the polyethylene-polypropylene copolymer in a weight ratio of 1: 9 to 9: 1.
The method of claim 1,
The polyolefin resin is a composition for a polarizing film having a melt flow index (MFI) of 1 g / 10min to 15 g / 10min.
The method of claim 1,
The polyolefin resin is a composition for polarizing films having a haze of 5% or less.
The method of claim 1,
The polyolefin resin is a composition for polarizing film having a crystallinity of 50% or less.
The method of claim 1,
The dichroic dye is a composition for a polarizing film having a dichroic ratio of 1.5 to 14.
The method of claim 1,
The dichroic dye is a composition for a polarizing film having an absorbance of 0.38 or less in light of all wavelengths of 380nm to 780nm.
In claim 1,
The dichroic dye is a composition for a polarizing film is contained in 0.05 to 2 parts by weight based on 100 parts by weight of the polyolefin resin.
The method of claim 1,
The difference between the solubility parameter of the said polyolefin resin and the solubility parameter of the said dichroic dye is 10 or less compositions.
It contains the composition for polarizing films of any one of Claims 1-12,
The polarizing film uniaxially stretched.
The method of claim 13,
The polarizing film is a polarizing film having a total light transmittance of 20% or more and a polarization efficiency of 85% or more in the wavelength range of 380 nm to 780 nm.
In claim 13,
The polarizing film is a polarizing film having a thickness of 25㎛ to 150㎛.
Melting the composition for polarizing film according to any one of claims 1 to 12,
Putting the molten mixture into a mold and pressing to prepare a sheet, and
Uniaxially stretching the sheet
Method for producing a polarizing film comprising a.
The method of claim 16,
Uniaxially stretching the sheet is a method of producing a polarizing film that is stretched at an elongation of 300% to 1000%.
A first display panel and a second display panel facing each other,
A liquid crystal layer between the first display panel and the second display panel, and
A polarizing film positioned outside at least one of the first display panel and the second display panel.
Including,
The polarizing film is a polarizing film according to claim 13
Liquid crystal display.

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