KR100644013B1 - A prism-patterned broadband reflection typed brightness enhancement polarizer, the manufacturing method thereof and a liquid crystal display having the same - Google Patents

Abstract

The present invention relates to an integrated broadband reflective high brightness polarizing plate having a prism pattern, a method of manufacturing the same, and a liquid crystal display device having the same. The method of manufacturing the integrated broadband reflective high brightness polarizing plate of the present invention is (S1) a curable nematic structure having a specific structure. Preparing a plurality of cholesteric liquid crystal films formed by varying a mixing ratio of the liquid crystal compound and the curable chiral compound to have different selective reflection wavelength ranges; (S2) stacking the plurality of cholesteric liquid crystal films to produce a laminated cholesteric liquid crystal film having a broadband selective reflection wavelength region; (S3) manufacturing a broadband reflective polarizer by laminating a 1 / 4λ retardation film on one surface of the laminated cholesteric liquid crystal film; (S4) coating a photocurable resin solution on one surface of the broadband reflective polarizer; And (S5) forming a prism pattern by irradiating light while passing the surface coated with the photocurable resin liquid through a roll having an embossed prism pattern. Since the integrated broadband reflective high brightness polarizer manufactured according to the manufacturing method of the present invention has a wide range of selective reflection wavelength range of the cholesteric liquid crystal films constituting the polarizing plate, even if only a few liquid crystal films are stacked, the visible light region is covered. do. In addition, since the prism pattern coating film formed on one surface of the polarizing plate is integrated with the polarizing plate, light loss at the interface can be prevented. In addition, the manufacturing method of the present invention is economical because the manufacturing process can be shortened and the defect rate can be reduced.

Description

Integrated broadband reflective high brightness polarizer having a prism pattern, a method of manufacturing the same, and a liquid crystal display having the same.

1A and 1B are cross-sectional views illustrating structures of an integrated broadband reflective high brightness polarizer having a prism pattern, respectively, according to one embodiment of the present invention;

2 is a process chart showing a process of forming a prism pattern in the manufacturing method of the present invention,

3 is a selective reflection region spectrum of the laminated cholesteric liquid crystal film used in the integrated broadband reflective high brightness polarizer according to Example 1 of the present invention,

4 is a selective reflection region spectrum of the laminated cholesteric liquid crystal film used in the reflective polarizer according to Comparative Example 1.

The present invention relates to a broadband reflective polarizer having a laminated cholesteric liquid crystal film in which a plurality of cholesteric liquid crystal films formed to have different selective reflection wavelength ranges, a manufacturing method thereof, and a liquid crystal display device having the same. More particularly, the present invention relates to an integrated broadband reflective high brightness polarizer having a prism pattern formed on one surface of a broadband reflective polarizer, a manufacturing method thereof, and a liquid crystal display device having the same.

Display panels are widely used in display devices such as electronic calculators, electronic clocks, car navigation systems, office automation devices, mobile phones, laptop computers, and information communication terminals. For example, liquid crystal displays have transparent electrodes and alignment layers formed therein. The liquid crystal is injected between the opposing upper panel and the lower panel. Since the liquid crystal display device currently used uses linear polarization, the absorption type polarizing film is arrange | positioned before and behind a panel, and is used.

Absorption-type polarizing film is usually produced by adsorbing iodine or dichroic dye on a polyvinyl alcohol film and stretching it in a certain direction. The polarizing film thus prepared has weak mechanical strength in the direction of the transmission axis and shrinks due to heat or moisture. There is a disadvantage that the polarization function is significantly reduced. Therefore, it is used by the structure which adhere | attached with the adhesive agent between support bodies, such as a cellulose acetate film. As described above, the absorption type polarizing film using the polyvinyl alcohol film absorbs light vibrating in one direction and passes only the light vibrating to the other to make linearly polarized light. Therefore, the efficiency of the polarizing film cannot theoretically exceed 50%. This is a major cause of lowering the efficiency and brightness of the LCD.

On the other hand, if the reflective polarizing film manufactured using the cholesteric liquid crystal is further used between the liquid crystal panel having the absorption type polarizing film and the reflecting plate, the disadvantages of the absorption type polarizing film described above can be improved. The cholesteric liquid crystal has a selective reflection characteristic in which the twisted direction of the helical structure of the liquid crystal coincides with the circular polarization direction, and the wavelength reflects only circular polarized light such as the spiral pitch of the liquid crystal. By using this selective reflection characteristic, it is possible to manufacture a polarizing plate which converts unpolarized light of a certain wavelength band into a specific circularly polarized light. That is, when non-polarized light in which left circularly polarized light and right circularly polarized light are mixed in half is incident on a cholesteric liquid crystal film having a leftward or preferential spiral structure, circularly polarized light such as a spiral direction is reflected and circularly polarized light in the opposite direction is Is transmitted. At this time, the transmitted circularly polarized light changes to linearly polarized light while passing through the 1 / 4λ retardation film. On the other hand, the reflected circularly polarized light is changed by the polarization direction upon re-reflection in the reflecting plate, thereby transmitting the liquid crystal film. Therefore, the additional use of a polarizing film made of a cholesteric liquid crystal film can theoretically make the luminance always remarkable since there is no loss of light in theory.

However, since the backlight used in the liquid crystal display generates light in the visible light band (400 to 700 nm), which is mainly a color display area, the selective reflection area of the cholesteric liquid crystal film must cover all visible light areas. If not, light transmitted through the polarizing film in a non-polarized state is present, which degrades the image quality of the liquid crystal display. Since only one cholesteric liquid crystal film does not cover all of these visible light bands, a plurality of cholesteric liquid crystal films formed to have different selective reflection wavelength ranges as disclosed in Korean Patent Laid-Open Publication No. 1999-65280 The polarizing film should be manufactured by laminating | stacking. However, since the cholesteric liquid crystal compounds commonly used have a narrow width of the selective reflection wavelength region, at least four cholesteric liquid crystal films should be stacked to cover all visible light bands. Accordingly, the manufacturing process of the polarizing film is complicated and the economical efficiency is lowered, and the thickness of the manufactured polarizing plate is thick, which lowers the luminance characteristic.

In addition, the backlight unit of the liquid crystal display device is used by assembling a variety of functional films overlapping, in this case, each pass through each film, light scattering phenomenon occurs at the interface, the brightness is lowered. In particular, the prism film that improves the brightness by condensing the light generated from the light source to the front has a problem in that the defect rate is increased due to scratches or contamination due to foreign matters when assembled into the backlight unit.

The technical problem to be solved by the present invention is to solve the above problems, the width of the selective reflection wavelength region of the cholesteric liquid crystal films constituting the broadband reflective polarizer is wide enough to cover all visible light region even if only a few liquid crystal film laminated The present invention provides a thin-walled, economical, integrated broadband reflective high-brightness polarizing plate having a prism pattern coating film, and a liquid crystal display device having the same.

Another technical problem to be achieved by the present invention is to provide a method for manufacturing an integrated broadband reflective high brightness polarizer having the above-described characteristics, which is economical because it can shorten the manufacturing process and reduce the defective rate.

In order to achieve the above technical problem, the integrated broadband reflective high brightness polarizing plate having the prism pattern of the present invention comprises: (a) a broadband reflective polarizing plate having the following (i) and (ii); And (b) a prism pattern coating film formed on one surface of the broadband reflective polarizer.

(i) A plurality of cholesteric liquid crystal films formed to have different selective reflection wavelength regions by varying the mixing ratio of the curable nematic liquid crystal compound represented by the following Chemical Formula 1 and the curable chiral compound represented by the following Chemical Formula 2 Laminated cholesteric liquid crystal film having a wideband selective reflection wavelength range.

,

및 로 이루어진 군으로부터 선택된 어느 하나이고(m은 1~12의 정수이고 n은 1~3의 정수임), M은 메소겐 그룹으로서In Formula 1, S is a spacer

,

And Any one selected from the group consisting of (m is an integer from 1 to 12 and n is an integer from 1 to 3), M is a mesogen group

,

,

,

,

,

및

,

And

로

in

Any one selected from the group consisting of

,

및

로 이루어진 군으로부터 선택된 어느 하나이고(m은 1~12의 정수이고 n은 1~3의 정수임), M은 메소겐 그룹으로서

,

,

,

,

및

로 이루어진 군으로부터 선택된 어느 하나이고, C는 카이칼 그룹으로서

,

,

,

및

로 이루어진 군으로부터 선택된 어느 하나이다.In Formula 2, S is a spacer

,

And

Any one selected from the group consisting of (m is an integer from 1 to 12 and n is an integer from 1 to 3), M is a mesogen group

,

,

,

,

And

Any one selected from the group consisting of C is a caikal group

,

,

,

And

Any one selected from the group consisting of.

(ii) a 1 / 4λ retardation film laminated on one surface of the laminated cholesteric liquid crystal film.

In the integrated broadband reflective high brightness polarizer having the prism pattern of the present invention, the laminated cholesteric liquid crystal film has three center wavelengths of selective reflection wavelength range of 450 to 480 nm, 530 to 550 nm, and 590 to 610 nm, respectively. It is preferable that the cholesteric liquid crystal films are laminated.

In order to achieve the another technical problem of the present invention, the method of manufacturing an integrated broadband reflective high brightness polarizing plate having a prism pattern of the present invention (S1) is a curable nematic liquid crystal compound represented by the formula (1) and the curable represented by the formula (2) Preparing a plurality of cholesteric liquid crystal films formed by varying a mixing ratio of a chiral compound so as to have different selective reflection wavelength regions; (S2) stacking the plurality of cholesteric liquid crystal films to produce a laminated cholesteric liquid crystal film having a broadband selective reflection wavelength region; (S3) manufacturing a broadband reflective polarizer by laminating a 1 / 4λ retardation film on one surface of the laminated cholesteric liquid crystal film; (S4) coating a photocurable resin solution on one surface of the broadband reflective polarizer; And (S5) forming a prism pattern by irradiating light while passing the surface coated with the photocurable resin liquid through a roll having an embossed prism pattern.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the present invention. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, it is possible to replace them at the time of the present application It should be understood that there may be various equivalents and variations.

1A and 1B are cross-sectional views schematically illustrating structures of an integrated broadband reflective high brightness polarizer having a prism pattern, respectively, according to an embodiment of the present invention. Referring to Figure 1a, the integrated broadband reflective high brightness polarizing plate 10 of the present invention is (a) a broadband reflective polarizing plate, (i) laminated cholesteric liquid crystal film 11 and the laminated cholesteric liquid crystal film (Ii) a 1/4 lambda retardation film (13) laminated on one surface of (11), and (b) a prism pattern coating film (15) formed on one surface of the broadband reflective polarizing plate.

(a) Broadband Reflective Polarizer

(i) Laminated cholesteric liquid crystal film (11)

The laminated cholesteric liquid crystal film 11 may be formed to have a different selective reflection wavelength region by varying the mixing ratio of the curable nematic liquid crystal compound represented by the following Chemical Formula 1 and the curable chiral compound represented by the following Chemical Formula 2. It is a laminated cholesteric liquid crystal film having a broadband selective reflection wavelength region in which cholesteric liquid crystal films are laminated. As shown in FIGS. 1A and 1B, the laminated cholesteric liquid crystal film 11 has a structure in which cholesteric liquid crystal films 11a, 11b, and 11c having different selective reflection wavelength regions are stacked. The cholesteric liquid crystal films 11a, 11b, and 11c are made of a cholesteric liquid crystal formed by mixing a curable nematic liquid crystal compound represented by the following Chemical Formula 1 and a curable chiral compound represented by the following Chemical Formula 2.

<Formula 1>

,

및

로 이루어진 군으로부터 선택된 어느 하나이고(m은 1~12의 정수이고 n은 1~3의 정수임), M은 메소겐 그룹으로서In Formula 1, S is a spacer

,

And

Any one selected from the group consisting of (m is an integer from 1 to 12 and n is an integer from 1 to 3), M is a mesogen group

,

,

,

,

,

및

,

And

로

in

It is any one selected from the group consisting of.

<Formula 2>

,

및

로 이루어진 군으로부터 선택된 어느 하나이고(m은 1~12의 정수이고 n은 1~3의 정수임), M은 메소겐 그룹으로서

,

,

,

,

및

로 이루어진 군으로부터 선택된 어느 하나이고, C는 카이칼 그룹으로서

,

,

,

및

로 이루어진 군으로부터 선택된 어느 하나이다.In Formula 2, S is a spacer

,

And

Any one selected from the group consisting of (m is an integer from 1 to 12 and n is an integer from 1 to 3), M is a mesogen group

,

,

,

,

And

Any one selected from the group consisting of C is a caikal group

,

,

,

And

Any one selected from the group consisting of.

The width of the selective reflection region of the cholesteric liquid crystal film depends on the nematic liquid crystal compound. When the cholesteric liquid crystal film is manufactured using the curable nematic liquid crystal compound of Formula 1, the cholesteric liquid crystal having a large width of the selective reflection region is formed. Films can be produced. Accordingly, since only a small number of cholesteric liquid crystal films may be stacked to cover all visible light regions, a high-brightness polarizer having a small thickness and economical efficiency may be provided. On the other hand, since the curable chiral compound of Formula 2 is excellent in compatibility with the curable nematic liquid crystal compound of Formula 1, it contributes to the improvement of the polarization characteristics of the cholesteric liquid crystal film.

In the laminated cholesteric liquid crystal film 11, the selective reflection wavelength region of the cholesteric liquid crystal films 11a, 11b, and 11c is determined according to the mixing ratio of the curable nematic liquid crystal compound and the curable chiral compound. For example, if the mixing ratio of the cholesteric liquid crystal films is adjusted so that the center wavelengths of the selective reflection wavelengths are 450 to 480 nm, 530 to 550 nm, and 590 to 610 nm, respectively, only three cholesteric liquid crystal films are stacked. The visible light region can be covered efficiently.

(ii) 1 / 4λ retardation film (13)

One side of the laminated cholesteric liquid crystal film 11 is laminated with a 1/4 lambda retardation film 13 for changing circularly polarized light into linearly polarized light. As the 1 / 4λ retardation film, a commonly used 1 / 4λ retardation film may be used, and the retardation film having a refractive index in the thickness direction is larger than the refractive index in the planar direction (Japanese Patent Nos. 2612196, 2994013, 2818983, 3309452, and 3168850). And the like).

(b) Prism pattern coating film 15

The prism pattern coating film 15 is formed on one surface of the broadband reflective polarizer. As shown in FIGS. 1A and 1B, the prism pattern coating film 15 may be formed on the opposite side of the 1 / 4λ retardation film 13, or may be formed on the 1 / 4λ retardation film 13. It may be formed. The prism pattern coating film 15 may serve as a prism film that was conventionally assembled and used separately in the backlight unit. That is, by using the fine prism structure of the prism pattern, the light incident from the light source is focused in a specific direction (particularly, the normal direction of the light exit surface), thereby improving the efficiency of the backlight. The arrangement and shape of the prism pattern is not limited as long as it can condense light in a specific direction. For example, as disclosed in Japanese Patent Application Laid-open No. Hei 10-319216, a triangle, a semicircle, a wave, an egg, a cycle Patterns, such as an Lloyd shape, can be formed. Since the delta pattern is known to be useful for increasing the efficiency of the backlight, the delta pattern is particularly preferred.

Since the integrated broadband reflective high brightness polarizing plate having the above-described structure has a wide range of selective reflection wavelength range of the cholesteric liquid crystal films constituting the polarizing plate, even if only a few liquid crystal films are stacked, the visible light region is covered. In addition, since all components including the prism pattern coating film are integrated, light loss at the interface can be prevented.

Looking at the manufacturing method of the integrated broadband reflective high brightness polarizing plate of the present invention, for example, as follows.

First, a plurality of cholesteric liquid crystal films formed by varying the mixing ratio of the curable nematic liquid crystal compound represented by Formula 1 and the curable chiral compound represented by Formula 2 to have different selective reflection wavelength ranges are prepared. (Step S1). In more detail, the curable nematic liquid crystal compound of Formula 1 and the curable chiral compound of Formula 2 are dissolved in an organic solvent with a photoinitiator at a predetermined ratio, roll coated onto a substrate, and then passed through a dryer to dry the solvent. After the alignment, a cholesteric liquid crystal film having a predetermined selective reflection wavelength range is manufactured by UV irradiation. In the same manner, cholesteric liquid crystal films having different selective reflection wavelength ranges are prepared by varying the mixing ratio of the curable nematic liquid crystal compound of Formula 1 and the curable chiral compound of Formula 2.

Subsequently, a plurality of cholesteric liquid crystal films having different selective reflection wavelength regions are stacked to prepare a laminated cholesteric liquid crystal film having a wide band selective reflection wavelength region (step S2). The lamination method is not limited as long as it can integrate the respective cholesteric liquid crystal films, but it is convenient to laminate each other using an adhesive.

Then, a 1/4 λ phase difference film is laminated on one surface of the manufactured cholesteric liquid crystal film to prepare a broadband reflective polarizer (step S3). It is convenient to use the method of laminating retardation film using an adhesive as well.

Subsequently, the photocurable resin solution is coated on one surface of the broadband reflective polarizer (step S4). As the photocurable resin solution, it is preferable to use a liquid resin solution composed of monomers or oligomers which can be photocured without using a solvent. For example, a solution in which an acrylate monomer and an additive are formulated can be used. In particular, as the photocurable resin liquid, it is more preferable to use a resin which is cured by ultraviolet rays and electron beams as an oligomer or monomer having a structure containing a lot of benzene rings and mixtures thereof, and various monomers having aromatic groups can be used. Examples include oligomers having aromatic groups such as bisphenol A polyphenylene diacrylate, dibromo bisphenol A polyethoxylate diacrylate oligomer, 2-hydroxy-3-phenoxy-propyl acrylate and bisphenol A. Monomers having an aromatic group, such as diethylene diacrylate, may be used alone or in combination. A photoinitiator for curing the oligomer and / or monomer may be added to the composition. As a coating method, a resin solution having a predetermined thickness may be coated on the substrate using a gravure roll coater or a comma coater. At this time, the thickness of the coating liquid to be raised on the substrate film through the coater is preferably 10 to 45 μm, more preferably. Preferably it is 15-25 micrometers.

Finally, the prism pattern is formed by irradiating light while passing the surface coated with the photocurable resin liquid through a roll having an embossed prism pattern (step S5). 2 shows a process of forming a prism pattern. Referring to FIG. 2, the surface coated with the photocurable resin liquid passes through a roll in which the prism pattern is embossed, and the embossed prism pattern dips the photocurable resin liquid to form a pattern. On the other hand, the light irradiation apparatus on the opposite side of the roll is irradiated with light to fix the shaped pattern.

Hereinafter, examples will be described in detail to help understand the present invention. However, embodiments according to the present invention can be modified in many different forms, the scope of the invention should not be construed as limited to the following examples. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

Example 1

First, three cholesteric liquid crystal films having different selective reflection wavelength ranges were prepared. The curable nematic liquid crystal compound (LC1057 from BASF) and the curable chiral compound (LC756 from BASF) were dissolved in cyclopentanone at a concentration of 30% by weight. The content of the curable chiral compound added in the preparation of each cholesteric liquid crystal film was 7.7% by weight, 6.2% by weight and 5.5% by weight relative to the content of the curable nematic liquid crystal compound, respectively, and 5% by weight of the photoinitiator (IG184, Ciba). -Geigy) and 0.2% by weight of leveling agent (BYK361, BYK) were added as additives. Each of the prepared solutions was roll coated on a polyethylene terephthalate film coated with a horizontal alignment layer, and then the solvent was dried in the dryer to orient the liquid crystal, and then UV light irradiation was used to prepare cholesteric liquid crystal films, respectively. Drying conditions were 85 ℃, UV light irradiation was used a 300W (center wavelength 360nm) lamp. The center wavelengths of the selective reflection regions of the respective cholesteric liquid crystal films obtained were 470 nm, 535 nm, and 600 nm, respectively.

The prepared cholesteric liquid crystal films were pressure-bonded using an adhesive in the order of the central wavelength from the short wavelength to the long wavelength. The adhesive was in the form of a solution, as in the case of coating the liquid crystal material, after the thin film coating by a roll coating method, the solvent was dried and pressed in a dryer. After pressing, it was aged for a certain time and completely bonded. The thickness of the prepared cholesteric liquid crystal film was about 13 microns.

Subsequently, a 1 / 4λ retardation film (thickness 50 microns, retardation 110 nm, Nx: 1.5817, Ny: 1.5795, Nz) coated with a pressure sensitive adhesive (PSA) on a short wavelength surface of the laminated liquid crystal film prepared by the above-described method : 1.5778) was pressed at room temperature to prepare a broadband reflective polarizer.

Then, the ultraviolet curable resin liquid was coated on the retardation film attachment surface of the manufactured broadband reflective polarizing plate. The UV curable resin liquid composition is composed of 60% by weight of bisphenol A polyphenylene diacrylate oligomer and 40% by weight of 2-hydroxy-3-phenoxy-propyl acrylate monomer as an initiator. ) 3% by weight of the initiator "Darocure 1173" based on the total content of the curable composition.

Subsequently, the UV curable resin solution was coated to a thickness of 30 μm through the process shown in FIG. 2 and the pattern was imprinted to fix the right angle of the prism portion through a UV curing apparatus to manufacture an integrated broadband reflective high brightness polarizing plate. The prepared prism portion had a refractive index of 1.60 and a prism right angle of 90 degrees.

Example 2

An integrated broadband reflective high brightness polarizing plate was manufactured in the same manner as in Example 1 except that the prism pattern coating film was formed on the opposite side of the retardation film attaching surface.

Comparative Example 1

A reflective polarizing plate was manufactured in the same manner as in Example 1, except that the curable nematic liquid crystal compound and the curable chiral compound were each used (Merck Co., Ltd. RMS 02) and (Merck Co., Ltd. RMS 03), respectively.

Comparative Example 2

A broadband reflective polarizer was manufactured in the same manner as in Example 1, and then a prism film (3M BEF-II) was placed on the surface of the retardation film.

Comparative Example 3

A polarizing plate was manufactured in the same manner as in Comparative Example 1, and then a prism film (3M BEF-II) was placed on the surface of the retardation film.

When the luminance was measured by mounting the reflective polarizers of the examples and comparative examples manufactured by the above-described method on the panel of the liquid crystal display device, the luminance when the reflective polarizer was not used was 100. The relative luminance when using the reflective polarizer produced by the present invention was measured and shown in Table 1.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Relative brightness 175 176 154 170 150

3 is a selective reflection region spectrum of a laminated cholesteric liquid crystal film used in the integrated broadband reflective high brightness polarizer according to Example 1 of the present invention, and FIG. 4 is a laminated cholester used in the reflective polarizer according to Comparative Example 1 This is the selective reflection area spectrum of the liquid crystal film. Referring to FIG. 3, a polarizing plate using a laminated cholesteric liquid crystal film in which a cholesteric liquid crystal film formed of a curable nematic liquid crystal compound and a curable chiral compound according to the present invention is laminated is three liquid crystals having a wider selective reflection area. Even when only the film is laminated, it can be seen that it covers all the visible light region. However, as shown in FIG. 4, the polarizing plate of Comparative Example 1, which uses a laminated cholesteric liquid crystal film in which a cholesteric liquid crystal film formed of a conventional nematic liquid crystal compound and a chiral compound, is laminated, has a visible light band that cannot be covered. It can be seen that there is a problem in achieving the high brightness characteristics.

These results are reflected in the relative luminance data of Table 1. That is, the relative luminance (Examples 1 and 2) of the liquid crystal display device having the polarizing plate using the laminated cholesteric liquid crystal films of FIG. 3 is the relative luminance of the liquid crystal display device having the polarizing plate using the laminated cholesteric liquid crystal films of FIG. The luminance is much greater than the relative luminance (Comparative Examples 1 and 3). On the other hand, the liquid crystal display devices (Examples 1 and 2) with polarizing plates on which a prism pattern coating film is formed are superior to the liquid crystal display device (comparative example 2) with polarizing plates on which prism films are placed.

Since the integrated broadband reflective high brightness polarizing plate having the prism pattern of the present invention manufactured by the above method has a wide range of selective reflection wavelengths of the cholesteric liquid crystal films constituting the polarizing plate, it is visible even when only several liquid crystal films are stacked. All light areas are covered. In addition, since the prism pattern coating film formed on one surface of the polarizing plate is integrated with the polarizing plate, light loss at the interface can be prevented. In addition, the manufacturing method of the present invention is economical by shortening the manufacturing process, the manufactured polarizing plate is also relatively thin thickness is maximized the brightness improving characteristics when used in the liquid crystal display device.

Claims (8)

(a) a broadband reflective polarizing plate comprising the following (i) and (ii); And (i) A plurality of cholesteric liquid crystal films formed to have different selective reflection wavelength regions by varying the mixing ratio of the curable nematic liquid crystal compound represented by the following Chemical Formula 1 and the curable chiral compound represented by the following Chemical Formula 2 Laminated cholesteric liquid crystal film having a wideband selective reflection wavelength range, <Formula 1>

In Formula 1, S is a spacer

,

And

Any one selected from the group consisting of (m is an integer from 1 to 12 and n is an integer from 1 to 3), M is a mesogen group

,

,

,

And

in Any one selected from the group consisting of <Formula 2>

In Formula 2, S is a spacer

,

And

Any one selected from the group consisting of (m is an integer from 1 to 12 and n is an integer from 1 to 3), M is a mesogen group

,

,

,

,

And

Any one selected from the group consisting of C is a caikal group

,

,

,

And

Any one selected from the group consisting of (ii) a 1 / 4λ retardation film laminated on one surface of the laminated cholesteric liquid crystal film, (b) An integrated broadband reflective high brightness polarizing plate having a prism pattern, comprising a prism pattern coating film formed on one surface of the broadband reflective polarizing plate. The cholesteric liquid crystal film of claim 1, wherein the cholesteric liquid crystal film is formed by stacking three cholesteric liquid crystal films having a center wavelength of 450 nm, 480 nm, 530 nm, 550 nm, and 590 nm to 610 nm, respectively. An integrated broadband reflective high brightness polarizer having a prism pattern. The prism pattern of claim 2, wherein the laminated cholesteric liquid crystal film comprises three cholesteric liquid crystal films each having a center wavelength of 470 nm, 535 nm, and 600 nm in the selective reflection wavelength region. Having an integrated broadband reflective high brightness polarizer. (S1) preparing a plurality of cholesteric liquid crystal films formed by varying the mixing ratio of the curable nematic liquid crystal compound represented by the following formula (1) and the curable chiral compound represented by the following formula (2) each having a different selective reflection wavelength range Making; <Formula 1>

In Formula 1, S is a spacer

,

And

Any one selected from the group consisting of (m is an integer from 1 to 12 and n is an integer from 1 to 3), M is a mesogen group

,

,

,

And

in Any one selected from the group consisting of <Formula 2>

In Formula 2, S is a spacer

,

And

Any one selected from the group consisting of (m is an integer from 1 to 12 and n is an integer from 1 to 3), M is a mesogen group

,

,

,

,

And

Any one selected from the group consisting of C is a caikal group

,

,

,

And

Is any one selected from the group consisting of: (S2) stacking the plurality of cholesteric liquid crystal films to produce a laminated cholesteric liquid crystal film having a broadband selective reflection wavelength region; (S3) manufacturing a broadband reflective polarizer by laminating a 1 / 4λ retardation film on one surface of the laminated cholesteric liquid crystal film; (S4) coating a photocurable resin solution on one surface of the broadband reflective polarizer; And (S5) of the integrated broadband reflective high-brightness polarizing plate having a prism pattern comprising the step of irradiating light while passing the surface coated with the photocurable resin liquid on the embossed roll of the prism pattern; Manufacturing method. The cholesteric liquid crystal film according to claim 4, wherein the laminated cholesteric liquid crystal film is laminated with three cholesteric liquid crystal films in which the center wavelength of the selective reflection wavelength range is adjusted to 450 to 480 nm, 530 to 550 nm, and 590 to 610 nm, respectively. A method of manufacturing an integrated broadband reflective high brightness polarizing plate having a prism pattern, which is produced by The cholesteric liquid crystal film of claim 5, wherein the laminated cholesteric liquid crystal film is manufactured by stacking three cholesteric liquid crystal films, each of which is adjusted so that the center wavelength of the selective reflection wavelength range is 470 nm, 535 nm, and 600 nm, respectively. A method of manufacturing an integrated broadband reflective high brightness polarizer having a prism pattern. The method of manufacturing an integrated broadband reflective high brightness polarizing plate having a prism pattern according to claim 4, wherein the coating thickness of the photocurable resin liquid is 15 to 25 µm. A liquid crystal display device comprising the integrated broadband reflective high brightness polarizing plate according to any one of claims 1 to 3.

Images