Polarizing plate and optical display device

Abstract

The invention discloses a polarizing plate for an optical display device and the optical display device. The polarizing plate comprises a polarizer; and a retardation layer laminated on one surface of the polarizer, wherein the retardation layer includes: a retardation layer that satisfies nxgt at a wavelength of 550 nm; nzgt; nzgt; (In the formula, nx, ny, and nz refer to the refractive index of the retardation film in the slow axis direction, the refractive index of the retardation film in the fast axis direction, and the refractive index of the retardation film in the thickness direction at a wavelength of 550 nm. ), the orientation direction of the main chain of the resin contained in the retardation film is about-5 DEG to about + 5 DEG with respect to the light absorption axis of the polarizer, and the retardation film has a biaxial degree of about 0.3 to about 0.7 at a wavelength of 550 nm.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefits of Korean Patent Application No. 10-2023-0086333 filed in the Korean Intellectual Property Office on July 4, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] One or more embodiments of the present disclosure relate to a polarizing plate and an optical display device including the polarizing plate. Background Art

[0004] The liquid crystal display device is a panel for an optical display device, and includes a liquid crystal panel, a viewer-side polarizer laminated on the upper surface of the liquid crystal panel, and a light source side polarizer laminated on the lower surface of the liquid crystal panel. Among the driving methods of the liquid crystal panel, the transverse electric field method is a method in which the liquid crystal compound responds in the direction of entering the substrate surface by an electric field including a component approximately parallel to the substrate surface of the liquid crystal panel. The transverse electric field method includes an in-plane switching (IPS) method and a fringe-field switching (FFS) method. The transverse electric field method can expand the contrast and the viewing angle and minimize the color change by providing a delay layer between the liquid crystal panel and the polarizer.

[0005] According to a comparative embodiment of the present invention, the retardation layer may be a laminate of a +C layer and a +A layer. For example, the polarizing plate may be laminated in the order of a polarizer, a +C layer, an adhesive layer, and a +A layer. However, such a polarizing plate is provided with two retardation layers, namely, a +C layer and a +A layer. Therefore, in order to provide a thinning effect of the polarizing plate, it may be beneficial to make the retardation layer into a single layer. Summary of the invention

[0006] One or more aspects of the disclosed embodiments are directed to a polarizing plate having a single-layer retardation film, improving visibility at all azimuth angles, and minimizing color change.

[0007] One or more aspects of the disclosed embodiments are directed to a polarizing plate having a single-layer retardation film and reduced light transmittance at all azimuth angles.

[0008] One or more aspects of the embodiments of the present disclosure are directed to a polarizing plate having an excellent thickness thinning effect by having a single-layer retardation film.

[0009] One or more aspects of the disclosed embodiments are directed to a polarizing plate having a single-layer retardation film and enabling roll-to-roll manufacturing.

[0010] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the embodiments presented in the disclosure.

[0011] According to one or more embodiments of the present disclosure, a polarizing plate is provided.

[0012] The polarizing plate includes a polarizer and a delay layer located on (for example, laminated on) one (for example, one) surface of the polarizer, wherein the delay layer includes a delay film satisfying nx>nz>ny at a wavelength of 550nm (here, nx, ny and nz refer to the refractive index of the delay film in the slow axis direction, the refractive index of the delay film in the fast axis direction and the refractive index of the delay film in the thickness direction at a wavelength of 550nm, respectively.), the orientation direction of the main chain of the resin contained in the delay film is about -5° to about +5° relative to the light absorption axis of the polarizer, and the delay film has a degree of biaxiality of about 0.3 to about 0.7 at a wavelength of 550nm.

[0013] According to one or more embodiments of the present disclosure, an optical display device includes a polarizing plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated into and constitute a part of the present disclosure. The accompanying drawings illustrate embodiments of the present disclosure and together with the description are used to explain the principles of the present disclosure. The above and other aspects, features and benefits of the present disclosure will become more apparent to those of ordinary skill in the art according to the following exemplary embodiments of the present disclosure described in detail with reference to the accompanying drawings, in which:

[0015] Figure 1 A cross-sectional view of a polarizing plate according to one or more embodiments of the present disclosure is shown.

[0016] Figure 2 A cross-sectional view of a polarizing plate according to one or more embodiments of the present disclosure is shown.

[0017] Figure 3 The light transmittance values ​​(Y-axis, unit: %) according to the biaxiality (NZ) of the retardation film at a wavelength of 550 nm and the in-plane retardation (X-axis, unit: nm) of the retardation film at a wavelength of 550 nm are shown when the polarizing plate is installed and driven by the transverse electric field method, wherein Figure 3, ■ is the light transmittance when the NZ of the retardation film at a wavelength of 550 nm is 0.4, ● is the light transmittance when the NZ of the retardation film at a wavelength of 550 nm is 0.5, and ▲ is the light transmittance when the NZ of the retardation film at a wavelength of 550 nm is 0.6.

[0018] [Explanation of Symbols]

[0019] 100: Polarizer

[0020] 200: Delay film

[0021] 300: Upper protective layer

[0022] 400: Lower protective layer DETAILED DESCRIPTION

[0023] The present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present disclosure belongs can easily implement the present disclosure. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein.

[0024] In order to clearly illustrate the present disclosure in the accompanying drawings, parts not related to the description are omitted, and the same reference numerals are given to the same or similar components throughout the disclosure. The length and thickness of each component in the accompanying drawings are for illustrative purposes only, and the present disclosure is not limited to the length and thickness shown in the accompanying drawings.

[0025] The terms used herein are only used for the purpose of describing exemplary embodiments and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular forms "a / an", "one", and "the" used herein are intended to include the plural forms as well. In addition, when describing embodiments of the present disclosure, the use of "may" means "one or more embodiments of the present disclosure".

[0026] In the present disclosure, “in-plane retardation (Re)” may be expressed as Equation A, “thickness direction retardation (Rth)” may be expressed as Equation B, and “biaxiality (NZ)” may be expressed as Equation C:

[0027] Formula A

[0028] Re=(nx–ny)×d

[0029] Formula B

[0030] Rth=((nx+ny) / 2–nz)×d

[0031] Formula C

[0032] NZ=(nx–nz) / (nx–ny).

[0033] In equations A to C, nx, ny, and nz are the refractive indices of the optical element in the slow axis direction, the fast axis direction, and the thickness direction at the measurement wavelength, respectively, and d is the thickness of the optical element (unit: nm). In equations A to C, the measurement wavelength may be any specific wavelength from 450 nm to 650 nm.

[0034] In the present disclosure, unless otherwise specified, nx, ny and nz may respectively refer to the refractive index of the optical element in the slow axis (the axis with the maximum refractive index in the in-plane direction), the fast axis (the axis with the minimum refractive index in the in-plane direction) and the thickness direction at a wavelength of 550 nm.

[0035] In the present disclosure, when describing an angle, "+" refers to a counterclockwise direction relative to a reference, and "-" refers to a clockwise direction relative to a reference.

[0036] In the present disclosure, “(meth)acrylic acid” may refer to acrylic acid and / or methacrylic acid.

[0037] In the present disclosure, when describing a numerical range, "X to Y" means "X is greater than X and Y is less than Y (X≤ and ≤Y)."

[0038] The polarizing plate according to one or more embodiments may include a single-layer delay film. The polarizing plate improves visibility at all azimuth angles, minimizes or reduces color changes, reduces light transmittance at all azimuth angles, and exhibits an excellent and beneficial thickness thinning effect. As used herein, "reducing light transmittance" means that when the polarizing plate is applied to an optical display device and driven, the transmittance of light emitted at all azimuth angles is reduced, thereby preventing light leakage. The lower the maximum value of the light transmittance, the more advantageous it is. In one or more embodiments, when the polarizing plate is driven, the maximum value of the light transmittance may be about 0.5% or less than 0.5%, for example, 0 to about 0.5% or about 0.1% to about 0.5%.

[0039] The polarizing plate according to one or more embodiments may include a single-layer retardation film, and the polarizing plate enables roll-to-roll manufacturing, thereby improving workability and economic feasibility of manufacturing the polarizing plate.

[0040] The polarizing plate of one or more embodiments may include a polarizer and a delay layer located on (for example, laminated on) one (for example, one) surface of the polarizer, wherein the delay layer may include a delay film satisfying nx>nz>ny at a wavelength of 550nm (here, nx, ny and nz refer to the refractive index of the delay film in the slow axis direction, the refractive index in the fast axis direction and the refractive index in the thickness direction at a wavelength of 550nm, respectively.), the orientation direction of the main chain of the resin contained in the delay film is about -5° to about +5° relative to the light absorption axis of the polarizer, and the delay film has a biaxiality of about 0.3 to about 0.7 at a wavelength of 550nm.

[0041] In one or more embodiments, the retardation layer may be laminated on the light incident surface of the internal light of the polarizer. Here, the "light incident surface of the internal light of the polarizer" is the surface on which the light emitted from the panel of the optical display device is incident on the polarizer, and the internal light may be the light emitted from the backlight unit.

[0042] The polarizing plate can be a polarizing plate on the audience side or a polarizing plate on the light source side.

[0043] According to one or more embodiments, the retardation layer may be located between the polarizer of the audience-side polarizing plate and the panel (e.g., liquid crystal panel) of the optical display device. In one or more embodiments, the light absorption axis of the polarizer in the audience-side polarizing plate may be substantially orthogonal to the orientation direction of the liquid crystal of the panel.

[0044] According to one or more embodiments, the retardation layer may be located between the polarizer of the light source side polarizing plate and the panel of the optical display device. In one or more embodiments, the light absorption axis of the polarizer in the light source side polarizing plate may be substantially orthogonal to the alignment direction of the liquid crystal of the panel.

[0045] The retardation film is a single-layer retardation film. This has the effect of thinning the thickness of the polarizing plate and improving the processability and economic feasibility of manufacturing the polarizing plate. Here, "single-layer retardation film" refers to a retardation film that includes only one layer (e.g., consists of only one layer) without two or more layers connected by an adhesive layer or a bonding layer.

[0046] According to one or more embodiments, the retardation film may have a thickness of about 40 micrometers (μm) to about 100 micrometers, such as about 40 μm, about 45 μm, about 50 μm, about 55 μm, about 60 μm, about 65 μm, about 70 μm, about 75 μm, about 80 μm, about 85 μm, about 90 μm, about 95 μm or about 100 μm, such as about 40 μm to about 80 μm. Within the above range, the retardation film can be applied to the polarizing plate and provide a thickness thinning effect.

[0047] In one or more embodiments, the retardation layer may include only the retardation film (eg, consist of only the retardation film). This has the effect of thinning the thickness of the polarizing plate and improving the processability and economic feasibility of manufacturing the polarizing plate.

[0048] According to one or more embodiments, the polarizing plate may have only a retardation film between the polarizer and an adherend (e.g., a panel for an optical display device). In one or more embodiments, in the polarizing plate, an adhesive layer, a retardation film, and an adhesive layer may be sequentially laminated on one surface of the polarizer, and the adhesive layer may be adhered to the adherend.

[0049] According to one or more embodiments, the polarizing plate may have a retardation film and one or more lower protective layers between the polarizer and an adherend (e.g., a panel for an optical display device). The lower protective layer may be present between the polarizer and the retardation film and / or between the retardation film and the adherend. In one or more embodiments, in the polarizing plate, the adhesive layer, the retardation film, the lower protective layer, and the adhesive layer may be sequentially laminated on one surface of the polarizer, and the adhesive layer may be adhered to the adherend.

[0050] In one or more embodiments, the lower protective layer may have an in-plane retardation of about 10 nanometers (nm) or less than 10 nm, such as about 0 nm, about 1 nm, about 2 nm, about 3 nm, about 4 nm, about 5 nm, about 6 nm, about 7 nm, about 8 nm, about 9 nm or about 10 nm, such as 0 nm to about 10 nm at a wavelength of 550 nm. Within the above range, the effect of protecting the polarizer can be provided without affecting the function and effect of the retardation film. The lower protective layer may be an optically transparent film or coating. For example, in one or more embodiments, the lower protective layer may be a film made of one or more resins selected from the following: cellulose resins including triacetylcellulose (TAC), polyester resins including polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate and polybutylene naphthalate, cyclic olefin copolymer (COC) resins, cyclic olefin polymer (COP) resins, polycarbonate resins, polyether sulfone resins, polysulfone resins, polyamide resins, polyimide resins, polyolefin resins, polyarylate resins, polyvinyl alcohol resins, polyvinyl chloride resins, polyvinylidene chloride resins and acrylic resins.

[0051] The retardation film satisfies nx>nz>ny at a wavelength of 550nm (here, nx, ny and nz refer to the refractive index of the retardation film in the slow axis direction, the refractive index in the fast axis direction and the refractive index in the thickness direction at a wavelength of 550nm, respectively.), and the orientation direction of the main chain of the resin contained in the retardation film is -5° to +5° relative to the light absorption axis of the polarizer. This makes it easy to improve visibility at all azimuths, minimize color changes and reduce light transmittance at all azimuths even when the polarizing plate is a single layer and has a retardation film that satisfies nx>nz>ny at a wavelength of 550nm.

[0052] The retardation film satisfies nx>nz>ny at a wavelength of 550nm. This ensures nx>ny and 0<(nx-nz) / (nx-ny)<1, so that when the retardation film is used, the change according to the viewing angle may be small, and when applied to a birefringent optical display panel, it can help improve the contrast or visibility in a black and white display and reduce color changes.

[0053] According to one or more embodiments of the present disclosure, (nx-ny) may be about 0.0022 to about 0.0075, for example, about 0.0022, about 0.0025, about 0.0030, about 0.0035, about 0.0040, about 0.0045, about 0.0050, about 0.0055, about 0.0060, about 0.0065, about 0.0070 or about 0.0075, for example, about 0.00275 to about 0.0075, and (nx- Nz) may be about 0.00066 to about 0.00525, such as about 0.00066, about 0.00070, about 0.00080, about 0.00090, about 0.0010, about 0.0015, about 0.0020, about 0.0025, about 0.0030, about 0.0035, about 0.0040, about 0.0045, about 0.0050 or about 0.00525, such as about 0.000825 to about 0.00525. Within the above range, when the retardation film is used, the change according to the viewing angle is small, and when applied to a birefringent optical display panel, it can help improve the contrast or visibility in a black and white display.

[0054] According to one or more embodiments of the present disclosure, in the delay film, nx may be about 1.500 to about 1.710, for example, about 1.500, about 1.550, about 1.600, about 1.650, about 1.700 or about 1.710, for example, about 1.500 to about 1.705, and ny may be about 1.480 to about 1.700, for example, about 1.480, about 1.500, about 1.550, about 1.600, about 1.650 or about 1.700, for example, about 1.485 to about 1.700, and nz may be about 1.500 to about 1.705, for example, about 1.500, about 1.550, about 1.600, about 1.650, about 1.700 or about 1.705, for example, about 1.500 to about 1.700. Within the above range, the above-mentioned ranges of (nx-ny) and (nx-nz) can be easily achieved, and the retardation film can be easily manufactured.

[0055] In the retardation film, the orientation direction of the main chain of the resin contained in the retardation film is about -5° to about +5° relative to the light absorption axis of the polarizer. This ensures that the retardation film is made of the composition for the retardation film described herein and that the retardation film satisfies the optical properties described herein, thereby providing the effect of improving visibility at all azimuth angles and reducing light transmittance at all azimuth angles.

[0056] According to one or more embodiments, the alignment direction of the main chain of the resin contained in the retardation film may be about -3° to about +3° and about 0° with respect to the light absorption axis of the polarizer. Within the above range, the above effects may be easily obtained.

[0057] The main chain orientation direction of the resin contained in the retardation film (i.e., the orientation direction of the main chain) can be measured by a suitable method known to a person skilled in the art. For example, the main chain orientation direction can be visually confirmed by checking the texture (grain) of the retardation film in the stretching direction. For example, the main chain orientation direction can be confirmed by measuring the crystal structure of the resin in the retardation film by X-ray measurement of the retardation film (e.g., X-ray diffraction (X-RD)), measuring the dynamic structure of the resin in the retardation film by nuclear magnetic resonance (NMR) measurement of the retardation film, and / or measuring the orientation direction by Raman and infrared spectroscopy measurement. The light absorption axis of the polarizer may be the machine direction of the polarizer.

[0058] When laminating the retardation film on the polarizer, the angle between the orientation direction of the main chain of the resin contained in the retardation film and the light absorption axis of the polarizer can be achieved by adjusting the angle between the orientation direction of the main chain and the light absorption axis of the polarizer.

[0059] According to one or more embodiments, the retardation film has a biaxiality of about 0.3 to about 0.7 at a wavelength of 550 nm. When the biaxiality is less than 0.3, the light transmittance in the black state increases at all viewing angles, which may make the black look poor. When the biaxiality exceeds 0.7, the light transmittance in the black state increases at all viewing angles, which may make the black look poor. For example, in one or more embodiments, the biaxiality may be about 0.3, about 0.31, about 0.32, about 0.33, about 0.34, about 0.35, about 0.36, about 0.37, about 0.38, about 0.39, about 0.4, about 0.41, about 0.42, about 0.43, about 0.44, about 0.45, about 0.46, about 0.47, about 0.48, about 0.49, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, about 10, about 11, about 12, about 13, about 14, about 15, about 16, about 17, about 18, about 19, about 20, about 21, about 22, about 23, about 24, about 25, about 26, about 27, about 28, about 29, about 30, about 31, about 32, about 33, about 34, about 35, about 36, about 37, about 38, about 39, about 31, about 32, about 33, about 34, about 35, about 36, about 37, about 38, about 39, about 30, about 31, about 32 51, about 0.52, about 0.53, about 0.54, about 0.55, about 0.56, about 0.57, about 0.58, about 0.59, about 0.6, about 0.61, about 0.62, about 0.63, about 0.64, about 0.65, about 0.66, about 0.67, about 0.68, about 0.69 or about 0.7, for example, about 0.4 to about 0.6, and within the above range, the effect may be significantly excellent and beneficial.

[0060] According to one or more embodiments, in the delay film, the value of expression 1 may be about 0.8 to about 1.2, and the value of expression 2 may be about 0.9 to about 1.1. Within the above range of the values ​​of expression 1 and expression 2, the delay film may be made of the composition for the delay film described herein, and may be easily provided to improve visibility at all viewing angles and reduce the light transmittance in the black state at all viewing angles. For example, in one or more embodiments, the value of expression 1 may be about 0.8, about 0.85, about 0.9, about 0.95, about 1.0, about 1.05, about 1.1, about 1.15 or about 1.2, such as about 0.9 to about 1.1, and the value of expression 2 may be about 0.9, about 0.95, about 1.0, about 1.05 or about 1.1, such as about 0.95 to about 1.05.

[0061] Expression 1

[0062] Re(450nm) / Re(550nm)

[0063] Expression 2

[0064] Re(650nm) / Re(550nm)

[0065] In Expression 1 and Expression 2, Re(450 nm), Re(550 nm), and Re(650 nm) are the in-plane retardations (unit: nm) of the retardation films at wavelengths of 450 nm, 550 nm, and 650 nm, respectively.

[0066] According to one or more embodiments, the retardation film has an in-plane retardation of about 220nm to about 300nm, such as about 220nm, about 225nm, about 230nm, about 235nm, about 240nm, about 245nm, about 250nm, about 255nm, about 260nm, about 265nm, about 270nm, about 275nm, about 280nm, about 285nm, about 290nm, about 295nm or about 300nm, such as about 250nm to about 280nm at a wavelength of 450nm to 650nm. Within the above range, the values ​​of Expression 1 and Expression 2 can be easily achieved, and the effect of reducing the light transmittance at all azimuth angles can be easily provided.

[0067] According to one or more embodiments, the retardation film may have an in-plane retardation of about 220 nm to about 300 nm and a biaxiality of about 0.3 to about 0.7 at a wavelength of 550 nm. Within the above range, the effect of reducing light transmittance at all azimuth angles may be easily provided. For example, in one or more embodiments, the in-plane retardation may be about 220 nm, about 225 nm, about 230 nm, about 235 nm, about 240 nm, about 245 nm, about 250 nm, about 255 nm, about 260 nm, about 265 nm, about 270 nm, about 275 nm, about 280 nm, about 285 nm, about 290 nm, about 295 nm, or 300 nm, and in one or more embodiments, the in-plane retardation is about 250 nm to about 280 nm, and the biaxiality may be about 0.3, about 0.35, about 0.4, about 0.45, about 0.5, about 0.55, about 0.6, about 0.65, or about 0.7, such as about 0.4 to about 0.6. Within the above range, the light transmittance can be significantly reduced to 0.5% or less than 0.5%.

[0068] Figure 3 The light transmittance value (Y-axis, unit: %) according to the biaxiality (NZ) of the retardation film at a wavelength of 550 nm and the in-plane retardation (X-axis, unit: nm) of the retardation film at a wavelength of 550 nm is shown when a polarizing plate (e.g., an in-plane switching (IPS) liquid crystal panel) is installed and driven by a lateral electric field method. Figure 3 , ■ is the light transmittance when the NZ of the retardation film at a wavelength of 550 nm is 0.4, ● is the light transmittance when the NZ of the retardation film at a wavelength of 550 nm is 0.5, and ▲ is the light transmittance when the NZ of the retardation film at a wavelength of 550 nm is 0.6.

[0069] Reference Figure 3It can be confirmed that when the in-plane retardation of the delay film at a wavelength of 550nm is 220nm to 300nm and the biaxiality is 0.3 to 0.7, especially when the in-plane retardation is 250nm to 280nm and the biaxiality is 0.4 to 0.6, the light transmittance is significantly reduced to 0.5% or less.

[0070] The retardation film may be formed of the composition for a retardation film.

[0071] The composition for a retardation film may include one or more of the aforementioned resins and one or more of the compounds represented by the following Chemical Formula I to Chemical Formula IV. The composition for a retardation film may allow the above-mentioned optical properties to be easily achieved.

[0072] In one or more embodiments, the resin may be a cellulose ester resin, and the resin may be included in the retardation film as a main component. Here, "main component" may mean that the component is contained in about 70 wt% or more, for example, about 75 wt% to about 99 wt%, or about 80 wt% to about 99 wt%, based on the solid content (e.g., amount) of the retardation film or the solid content of the composition for the retardation film.

[0073] The cellulose ester resin may include a cellulose ester resin in which at least a portion of hydrogen in the hydroxyl group (OH) of each of C2, C3 and C6 of cellulose is regioselectively substituted by one or more selected from the following: a plurality of aromatic -CO- groups as substituents and a plurality of first unsaturated or saturated (C 1-6 )alkyl-CO-group.

[0074] As used herein, an "aromatic -CO- group" may be: (i) (C 6-20 ) an aryl-CO- group, wherein the aryl group is unsubstituted or substituted with 1 to 5 R 1 or (ii) a heteroaryl-CO- group, wherein the heteroaryl group is a five- to ten-membered ring having 1 to 4 heteroatoms selected from N, O and S and the heteroaryl group is unsubstituted or replaced by 1 to 5 R 1 Replace. 1 As defined herein.

[0075] In one or more embodiments, the cellulose ester resin may include a cellulose ester resin in which at least a portion of the hydrogen in each of the hydroxyl groups (OH) of C2, C3, and C6 of cellulose is regioselectively substituted by one or more selected from the following, and at least a portion of the hydroxyl groups (OH) of each of C2, C3, and C6 is not regioselectively substituted: a plurality of aromatic -CO- groups as substituents and a plurality of first unsaturated or saturated (C 1-6)alkyl-CO-group.

[0076] According to one or more embodiments, the regioselectively substituted cellulose ester resin may include a plurality of alkyl-acyl or alkyl-CO- groups; a plurality of aryl-acyl or aryl-CO- groups; and a plurality of heteroaryl-acyl or heteroaryl-CO- groups.

[0077] In this disclosure, an acyl substituent or R—CO— group refers to a substituent having the structure shown below:

[0078]

[0079] In cellulose esters, these acyl or R-CO- groups may be bonded to the pyranose ring of cellulose through an ester bond (ie, through an oxygen atom).

[0080] The aromatic-CO-group may be an acyl substituent having an aromatic ring system. Examples of the aromatic-CO-group may include an aryl-CO-group and / or a heteroaryl-CO-group. Specific examples of the aromatic-CO-group may include benzoyl, naphthoyl, and furoyl, each of which may be unsubstituted or substituted.

[0081] The term "aryl-acyl" substituent refers to an acyl substituent in which "R" is an aryl group. The term "aryl" refers to a monovalent group formed by removing a hydrogen atom from a ring carbon of an arene (i.e., a monocyclic or polycyclic aromatic hydrocarbon). In the present disclosure, an aryl-acyl group may precede a carbon unit: for example, it may be (C 5-6 ) aryl-acyl, (C 6-12 ) aryl-acyl or (C 6-20 ) aryl-acyl. Examples of aryl groups suitable for use in various embodiments include phenyl, benzyl, tolyl, xylyl, and naphthyl, but the embodiments of the present disclosure are not limited thereto. These aryl groups may be substituted or unsubstituted.

[0082] The term "alkyl-acyl" refers to an acyl substituent in which "R" is an alkyl group. "Alkyl" refers to a monovalent group of a non-aromatic hydrocarbon from which a hydrogen atom has been removed, and may include heteroatoms. Alkyl groups suitable for use herein may have a linear form, a branched form, or a cyclic form, and may be saturated or unsaturated. Alkyl groups suitable for use herein may include any (C 1-20 ) alkyl, (C 1-12 ) alkyl, (C 1-5 ) alkyl or (C 1-3 In some embodiments, the alkyl group may be C 1-5 In some embodiments, the alkyl group may be C 1-3Straight chain alkyl. Non-limiting examples of suitable alkyl groups may include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl, cyclopentyl and cyclohexyl. Non-limiting examples of alkyl-acyl groups may include acetyl, propionyl and butyryl.

[0083] The term "haloalkyl" refers to an alkyl substituent in which one or more hydrogen atoms are replaced by halogen atoms. 1-6 ) alkyl. The haloalkyl group may have a straight chain form or a branched chain form. Non-limiting examples of the haloalkyl group may include chloromethyl, trifluoromethyl and dibromoethyl.

[0084] The term "heteroalkyl" refers to an alkyl group in which one or more carbon atoms are each replaced by a heteroatom such as N, O and / or S.

[0085] The term "heteroaryl" refers to an aryl group in which one or more carbon units of the aryl ring are each replaced by a heteroatom such as O, N and / or S. The heteroaryl ring may be monocyclic or polycyclic. In one or more embodiments, the units that make up the heteroaryl ring system may include, for example, a 5- to 20-membered ring system. A five-membered heteroaryl refers to a ring system in which the heteroaryl ring is formed by five atoms. Non-limiting examples of heteroaryls may include pyridyl, quinolyl, pyrimidinyl, and thienyl.

[0086] The term "alkoxy" refers to an alkyl group or alkyl-O- group terminally bonded to an oxy group. 1-6 ) alkoxy and the like. Non-limiting examples of alkoxy may include methoxy, ethoxy and propoxy.

[0087] The term "haloalkoxy" refers to an alkoxy group in which one or more of the hydrogen atoms are replaced by a halogen. 1-6 Non-limiting examples of halogenated alkoxy groups may include trifluoromethoxy, bromomethoxy, and 1-bromo-ethoxy.

[0088] The term "halo" refers to halogen, such as fluoro, chloro, bromo and / or iodo.

[0089] In the present disclosure, the term "degree of substitution (DS)" is used to describe the substitution level of sugar substituents as an anhydroglucose unit ("AGU"). In general, conventional cellulose includes three substitutable hydroxyl groups in each AGU. Therefore, DS can have a value from 0 to 3. However, due to end group contribution, low molecular weight cellulose mixed esters may have a total degree of substitution slightly higher than 3. Since DS is a statistical average, a value of 1 does not mean that all AGUs have a single substituent. In some embodiments, there may be unsubstituted anhydroglucose units, while some may have two substituents, and others may have three substituents, and it is more common for the values ​​of the embodiments to be non-integers. The total DS is defined as the average of all substituents in each anhydroglucose unit. The degree of substitution of each AGU may also refer to a specific substituent, such as a hydroxyl, acetyl, butyryl, or propionyl group. In one or more embodiments, the degree of substitution may represent the carbon unit of the anhydroglucose unit.

[0090] When the degree of substitution refers to the hydroxyl group (i.e., the degree of substitution of the hydroxyl group, DS OH ), the reference refers to the average number of hydroxyl groups per unsubstituted anhydroglucose. Therefore, DS is not used in calculating the total degree of substitution. OH .

[0091] Regioselectivity can be measured by determining the relative degree of substitution ("RDS") of the cellulose ester at C6, C3, and C2 using carbon-13 NMR spectroscopy. In the case of a single type of acyl substituent or when a second acyl substituent is present in a small amount (DS < 0.2), the RDS can be most easily measured in a direct manner by integration of ring carbon. When two or more acyl substituents are present in similar amounts, it may be necessary to fully substitute the cellulose ester with additional substituents in addition to determining the ring RDS to measure the RDS of each substituent independently by integration of the carbonyl carbon. In conventional cellulose esters, regioselectivity is generally not observed, and the RDS ratios of C6 / C3, C6 / C2, or C3 / C2 are generally close to 1 or less than 1. In essence, conventional cellulose esters are random copolymers. In contrast, when one or more acylating agents are added to cellulose dissolved in an appropriate solvent, the C6 position of the cellulose is acylated much faster than the C2 and C3 positions. Therefore, the C6 / C3 ratio and the C6 / C2 ratio are much greater than 1, which is characteristic of 6,3- or 6,2-enhanced regioselectively substituted cellulose esters.

[0092] According to one or more embodiments, cellulose esters generally include the following structure:

[0093]

[0094] In the above structure, R 2 , R 3 and R 6 may each independently be hydrogen (however, R 2 , R 3 and R 6 alkyl-acyl group or aryl-acyl group bonded to cellulose through an ester bond, and n is an integer greater than or equal to 1.

[0095] The cellulose esters prepared may have a degree of polymerization ("DP") (eg, the value of n) of 10 or greater, 50 or greater, 100 or greater, or 250 or greater.

[0096] The acylating agent may include an alkyl or aryl carboxylic acid anhydride, a carboxylic acid halide and / or a carboxylic acid ester containing the above alkyl or aryl groups suitable for use in the acyl substituent of the regioselectively substituted cellulose ester described herein, but is not limited thereto. Examples of suitable carboxylic acid anhydrides may include acetic anhydride, propionic anhydride, butyric anhydride, pivaloylanhydride, benzoic anhydride and naphthoyl anhydride, but embodiments of the present disclosure are not limited thereto. Examples of carboxylic acid halides may include chlorides or bromides of acetyl, propionyl, butyryl, pivaloyl, benzoyl and naphthoyl, but embodiments of the present disclosure are not limited thereto. Examples of carboxylic acid esters may include methyl esters of acetyl, propionyl, butyryl, pivaloyl, benzoyl and naphthoyl, but embodiments of the present disclosure are not limited thereto. In one or more embodiments, the acylating agent may be one or more carboxylic acid anhydrides selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride, pivaloyl anhydride, benzoyl anhydride and naphthoyl anhydride.

[0097] In one or more embodiments, the cellulose ester resin may include a cellulose ester resin that is regioselectively substituted with one or more of the following: a plurality of aromatic -CO- groups as substituents; a plurality of first unsaturated or saturated (C 1-6 ) an alkyl-CO- group; and a plurality of hydroxyl groups as substituents.

[0098] According to one or more embodiments, the cellulose ester resin may have a hydroxyl degree of substitution of about 0.2 to about 2.0, a degree of substitution at C2 of about 0.15 to about 0.8, a degree of substitution at C3 of about 0.05 to about 0.6, and a degree of substitution at C6 of about 0.05 to about 0.6, and a total degree of substitution of about 0.25 to about 2.5.

[0099] According to one or more embodiments, the cellulose ester resin may have a hydroxyl substitution degree of about 0.2 to about 2.0, a substitution degree of aromatic-CO groups or alkyl-CO groups at C2 of about 0.15 to about 0.8, a substitution degree of aromatic-CO groups or alkyl-CO groups at C3 of about 0.05 to about 0.6, a substitution degree of aromatic-CO groups or alkyl-CO groups at C6 of about 0.05 to about 0.6, and a total substitution degree of aromatic-CO groups and / or alkyl-CO groups of about 0.25 to about 2.5.

[0100] In one or more embodiments, the cellulose ester resin may have a first unsaturated or saturated (C 1-6 ) The degree of substitution (“DS FAk In one or more embodiments, the cellulose ester resin may have a first unsaturated or saturated (C 1-6 ) The degree of substitution of the alkyl-acyl substituent.

[0101] In one or more embodiments, the first unsaturated or saturated (C 1-20 The alkyl-CO- substituent may be acetyl, propionyl, butyryl, isobutyryl, 3-methylbutyryl, valeryl, 4-methylvaleryl, 3-methylvaleryl, 2-methylvaleryl, hexanoyl, or crotonyl. In one or more embodiments, the first unsaturated or saturated (C 1-6 The alkyl-CO- substituent may be acetyl, propionyl or crotonyl.

[0102] In one or more embodiments or in combination with any other embodiment, the cellulose ester resin may further include a plurality of second (C 1-20 )alkyl-CO-substituent. In one or more embodiments, the second (C 1-20 ) The degree of substitution (“DS SAk ”) can be from about 0.05 to about 0.6.

[0103] In one or more embodiments, the second (C 1-20 The alkyl-CO-substituent may be an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a 3-methylbutyryl group, a valeryl group, a 4-methylvaleryl group, a 3-methylvaleryl group, a 2-methylvaleryl group, a hexanoyl group, a pivaloyl group, or a 2-ethylhexanoyl group. 1-20The alkyl-CO-substituent may be acetyl, isobutyryl, 3-methylbutyryl, valeryl, 4-methylvaleryl, 3-methylvaleryl, 2-methylvaleryl, hexanoyl, or 2-ethylhexanoyl. 1-20 The alkyl-CO- substituent may be acetyl or 2-ethylhexanoyl.

[0104] In one or more embodiments or in combination with any other embodiment, the aromatic -CO- group may be (C 6-20 ) aryl-CO- groups, wherein the aryl group may be unsubstituted or substituted with 1 to 5 R 1 In one or more embodiments, the aromatic -CO- group may be unsubstituted or substituted with 1 to 5 R 1 In one or more embodiments, the aromatic -CO- group may be unsubstituted or substituted with 1 to 5 R 1 In one or more embodiments, the aromatic -CO- group may be unsubstituted or substituted with 1 to 5 R 1 Substituted naphthoyl.

[0105] In one or more embodiments or in combination with any other embodiment, the aromatic -CO- group can be unsubstituted or R 1 In one or more embodiments, the cellulose ester resin has a total DS of about 0.40 to about 1.20. ArCO In one or more embodiments, C2DS ArCO With C3DS ArCO The sum may be from about 0.30 to about 0.75.

[0106] In one or more embodiments or in combination with any other embodiment, the aromatic -CO- group can be unsubstituted or substituted with 1 to 5 R 1 In one or more embodiments, the cellulose ester resin has a total DS of about 0.30 to about 0.6. ArCO In one or more embodiments, C2DS ArCO With C3DS ArCO The sum of C2DS may be from about 0.20 to about 0.40. ArCO With C3DS ArCO The sum may be from about 0.30 to about 0.40.

[0107] In one or more embodiments or in combination with any other embodiments, the aromatic -CO- group may be a heteroaryl-CO- group, wherein the heteroaryl group may be a five- to ten-membered ring having 1 to 4 heteroatoms independently selected from N, O, and S, and wherein the heteroaryl group may be unsubstituted or substituted with 1 to 5 R1 In one or more embodiments, the heteroaryl-CO-group may be a pyridyl-CO-group, a pyrimidyl-CO-group, a furanyl-CO-group, or a pyrrolyl-CO-group. In one or more embodiments, the heteroaryl-CO-group may be a 2-furoyl group.

[0108] In one or more embodiments or in combination with any other embodiment, the cellulose ester resin has a totDS of about 0.4 to about 1.6 ArCO (e.g., total DS ArCO In one or more embodiments or in combination with any other embodiment, the cellulose ester resin has a totDS of about 1.0 to about 1.6. ArCO (e.g., total DS ArCO In one or more embodiments or in combination with any other embodiment, the cellulose ester resin has a totDS of about 0.3 to about 1.25. ArCO (e.g., total DS ArCO In one or more embodiments or in combination with any other embodiment, the cellulose ester resin has a totDS of about 0.4 to about 1.2. ArCO (e.g., total DS ArCO In one or more embodiments or in combination with any other embodiment, the cellulose ester resin has a totDS of about 0.4 to about 0.8. ArCO (e.g., total DS ArCO In one or more embodiments or in combination with any other embodiment, the cellulose ester resin has a totDS of about 0.3 to about 0.8. ArCO (e.g., total DS ArCO In one or more embodiments or in combination with any other embodiment, the cellulose ester resin has a totDS of about 0.3 to about 0.6. ArCO (e.g., total DS ArCO In one or more embodiments or in combination with any other embodiment, the cellulose ester resin has a totDS of about 0.2 to about 0.6. ArCO (e.g., total DS ArCO In one or more embodiments or in combination with any other embodiment, the cellulose ester resin has a totDS of about 0.2 to about 0.5. ArCO (e.g., total DS ArCO In one or more embodiments or in combination with any other embodiment, the cellulose ester resin has a totDS of about 0.8 to about 1.2. ArCO (e.g., total DS ArCO In one or more embodiments or in combination with any other embodiment, the cellulose ester resin has a totDS of about 0.5 to about 1.1.ArCO (e.g., total DS ArCO ).

[0109] In one or more embodiments or in combination with any other embodiments, DS OH In one or more embodiments or in combination with any other embodiments, DS OH In one or more embodiments or in combination with any other embodiments, DS OH In one or more embodiments or in combination with any other embodiments, DS OH In one or more embodiments or in combination with any other embodiments, DS OH In one or more embodiments or in combination with any other embodiments, DS OH In one or more embodiments or in combination with any other embodiments, DS OH From about 0.5 to about 0.8.

[0110] In one or more embodiments or in combination with any other embodiment, the C2DS ArCO With C3DS ArCO The sum is about 0.3 to about 1.25. In one or more embodiments or in combination with any other embodiment, C2DS ArCO With C3DS ArCO The sum is about 0.2 to about 0.4. In one or more embodiments or in combination with any other embodiment, C2DS ArCO With C3DS ArCO The sum is about 0.3 to about 0.4. In one or more embodiments or in combination with any other embodiment, C2DS ArCO With C3DS ArCO The sum is about 0.4 to about 1.2. In one or more embodiments or in combination with any other embodiment, C2DS ArCO With C3DS ArCO The sum is about 0.4 to about 1.1. In one or more embodiments or in combination with any other embodiment, C2DS ArCO With C3DS ArCO The sum is about 0.4 to about 1.0. In one or more embodiments or in combination with any other embodiment, C2DS ArCO With C3DS ArCO The sum is about 0.5 to about 1.1. In one or more embodiments or in combination with any other embodiment, C2DS ArCO With C3DS ArCOThe sum is about 0.6 to about 1.0. In one or more embodiments or in combination with any other embodiment, C2DS ArCO With C3DS ArCO The sum is about 0.6 to about 1.25. In one or more embodiments or in combination with any other embodiment, C2DS ArCO With C3DS ArCO The sum is about 0.30 to about 0.75.

[0111] In one or more embodiments, the composition for a retardation film, ie, the retardation film, may further include a component A, wherein the component A includes one or more selected from the compounds represented by Chemical Formula I to Chemical Formula IV:

[0112] Chemical formula I

[0113]

[0114] Chemical formula II

[0115]

[0116] Chemical formula III

[0117]

[0118] Chemical formula IV

[0119]

[0120] In Chemical Formulae I to IV,

[0121] Ring A may be (C 6-20 ) aryl or a five- to ten-membered heteroaryl group containing 1 to 4 heteroatoms independently selected from N, O and S;

[0122] Ring B may be (C 6-20 ) aryl or a five- to ten-membered heteroaryl group containing 1 to 4 heteroatoms independently selected from N, O and S;

[0123] Ring C may be (C 6-20 ) aryl or a five- to ten-membered heteroaryl group containing 1 to 4 heteroatoms independently selected from N, O and S;

[0124] R 1 Can be: saturated or unsaturated (C 1-20 ) alkyl; saturated or unsaturated halogenated (C 1-20 ) alkyl; (C 6-20 ) aryl; a five- to ten-membered heteroaryl group containing 1 to 4 heteroatoms independently selected from N, O and S; or -CH2C(O)-R3 ;

[0125] R 2 may be independently hydrogen, saturated or unsaturated (C 1-20 ) alkyl, or saturated or unsaturated halogenated (C 1-20 )alkyl;

[0126] R 3 Can be saturated or unsaturated (C 1-20 ) alkyl, saturated or unsaturated halogenated (C 1-20 ) alkyl, (C 6-20 ) aryl or a five- to ten-membered heteroaryl containing 1 to 4 heteroatoms independently selected from N, O and S, wherein the aryl or heteroaryl may be unsubstituted or substituted with 1 to 5 R 6 replace;

[0127] Each R 5 can be independently hydroxyl, cyano, saturated or unsaturated (C 1-20 ) alkyl, saturated or unsaturated halogenated (C 1-20 ) alkyl, saturated or unsaturated (C 1-20 ) alkoxy, saturated or unsaturated halogenated (C 1-20 ) alkoxy or halo;

[0128] Each R 6 can be independently hydroxyl, cyano, saturated or unsaturated (C 1-20 ) alkyl, saturated or unsaturated halogenated (C 1-20 ) alkyl, saturated or unsaturated (C 1-20 ) alkoxy, saturated or unsaturated halogenated (C 1-20 ) alkoxy, or halo, or (C 6-20 ) aryl, wherein the aryl group may be unsubstituted or substituted with 1 to 5 R 7 replace;

[0129] Each R 7 can be independently hydroxyl, saturated or unsaturated (C 1-6 ) alkyl, saturated or unsaturated halogenated (C 1-6 ) alkyl, or saturated or unsaturated (C 1-6 ) alkoxy;

[0130] R 8 Can be saturated or unsaturated (C 1-20 ) alkyl, saturated or unsaturated halogenated (C 1-20 ) alkyl, saturated or unsaturated (C 1-20 ) alkoxy, or saturated or unsaturated halogen (C 1-20 )alkoxy; and

[0131] Each R 9 Can be R4 -O-group, hydroxyl group, saturated or unsaturated (C 1-20 ) alkyl, a saturated or unsaturated hetero(C 1-20 ) alkyl, saturated or unsaturated halogenated (C 1-20 ) alkyl, saturated or unsaturated (C 1-20 )alkyl-CO-(C 1-20 )alkyl-group, saturated or unsaturated (C 1-20 )alkyl-COO-(C 1-20 )alkyl-group, saturated or unsaturated (C 1-20 )alkyl-COO-group, saturated or unsaturated (C 1-20 )alkyl-O-CO-group, saturated or unsaturated (C 1-20 )alkyl-CO-group, saturated or unsaturated (C 1-20 )alkoxy-(C 1-20 )alkyl-CO-O-(C 1-20 ) alkyl, saturated or unsaturated (C 1-20 )alkoxy-(C 1-20 )alkyl-O-CO-(C 1-20 ) alkyl, saturated or unsaturated (C 1-20 )alkoxy-(C 1-20 )alkyl-COO-(C 1-20 ) alkyl, (C 1-20 )alkoxy-(C 1-20 )alkyl-O-CO-(C 1-20 )alkyl-(C 6-10 ) aryl, or a five- to ten-membered heteroaryl group containing 1 to 4 heteroatoms independently selected from N, O and S;

[0132] R 4 Can be saturated or unsaturated (C 1-20 ) alkyl, saturated or unsaturated halogenated (C 1-20 ) alkyl, or saturated or unsaturated (C 1-20 )alkyl-CO-(C 1-20 )alkyl, each of which may be independently unsubstituted or substituted with 1 to 3 hydroxyl groups, saturated or unsaturated (C 1-20 ) alkyl, saturated or unsaturated halogenated (C 1-20 ) alkyl, saturated or unsaturated (C 1-20 ) alkoxy, saturated or unsaturated halogenated (C 1-20 ) alkoxy, saturated or unsaturated hydroxyl (C 1-20 ) alkyl, saturated or unsaturated (C 1-20 )alkoxy-(C 1-20 ) alkyl, saturated or unsaturated (C1-20 ) alkoxy-hydroxy (C 1-20 ) alkyl, saturated or unsaturated (C 1-20 )alkoxy-(C 1-20 )alkyl-CO-(C 1-20 ) alkyl, saturated or unsaturated (C 1-20 )alkyl-CO group, saturated or unsaturated (C 1-20 )alkyl-COO group, saturated or unsaturated (C 1-20 )alkyl-O-CO-(C 1-20 ) alkyl, saturated or unsaturated (C 1-20 )alkyl-COO-(C 1-20 ) alkyl, saturated or unsaturated (C 1-20 )alkoxy-(C 1-20 )alkyl-COO-(C 1-20 ) alkyl, or (C 1-20 )alkoxy-(C 1-20 )alkyl-O-CO-(C 1-20 )alkyl;

[0133] Each of these groups may be unsubstituted or substituted with 1 to 3 hydroxyl groups, saturated or unsaturated (C 1-20 ) alkyl, saturated or unsaturated halogenated (C 1-20 ) alkyl, saturated or unsaturated (C 1-20 ) alkoxy, saturated or unsaturated halogenated (C 1-20 ) alkoxy, saturated or unsaturated hydroxyl (C 1-20 ) alkyl, saturated or unsaturated (C 1-20 )alkoxy-(C 1-20 ) alkyl, saturated or unsaturated (C 1-20 ) alkoxy-hydroxy (C 1-20 ) alkyl, saturated or unsaturated (C 1-20 )alkoxy-(C 1-20 )alkyl-CO-(C 1-20 )alkyl-group, saturated or unsaturated (C 1-20 )alkyl-CO group, saturated or unsaturated (C 1-20 )alkyl-COO group, saturated or unsaturated (C 1-20 )alkyl-O-CO-(C 1-20 ) alkyl group, saturated or unsaturated (C 1-20 )alkyl-COO-(C 1-20 ) alkyl, saturated or unsaturated (C 1-20 )alkoxy-(C 1-20 )alkyl-COO-(C 1-20 ) alkyl, or (C 1-20 )alkoxy-(C1-20 )alkyl-O-CO-(C 1-20 )alkyl;

[0134] Each n can independently be 0, 1, 2, 3, 4 or 5;

[0135] Each m can independently be 0, 1, 2, 3 or 4;

[0136] k can be 0, 1, 3 or 4.

[0137] According to one or more embodiments, component A may be 1,3-diphenyl-1,3-propanedione, avobenzone, 2-hydroxy-4-(octyloxy)phenyl(phenyl)methanone, (2-hydroxy-4-methoxyphenyl)(2-hydroxyphenyl)methanone, 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-(hexyloxy)phenol (Tinuvin 1577), 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl]-5-[2-hydroxy-3-(dodecyloxy and tridecyloxy)propoxy]phenol (Tinuvin 400) , 2-(4-(4,6-bis([1,1'-biphenyl]-4-yl)-1,3,5-triazine-2-yl)-3-hydroxyphenoxy)propanoic acid isooctyl ester (Tinnafin 479), 6,6'-(6-(2,4-dibutoxyphenyl)-1,3,5-triazine-2,4-diyl)bis(3-butoxyphenol) (Tinnafin 460), 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl)-5-(3-((2-ethylhexyl)oxy)-2-hydroxypropoxy)phenol (Tinnafin 405), 7-diethylamino-4-methylcoumarin, or a combination thereof (e.g., any suitable combination).

[0138] According to one or more embodiments, based on the total solid content of 100% by weight of the composition, component A can be present in an amount of about 1% by weight or greater than 1% by weight. In one or more embodiments, based on the total solid content of 100% by weight of the composition, component A can be present in a range of about 1% by weight to about 30% by weight. In one or more embodiments, based on the total solid content of 100% by weight of the composition, component A can be present in a range of about 1% by weight to about 20% by weight. In one or more embodiments, based on the total solid content of 100% by weight of the composition, component A can be present in a range of about 1% by weight to about 15% by weight. Within the above range, the effect of the present disclosure can be easily achieved.

[0139] In one or more embodiments, the composition for the delay film may further include a plasticizer to increase the workability and flexibility of the delay film. The plasticizer may be included in an amount of about 0.1 wt % to about 10 wt %, for example, about 0.1 wt % to about 5 wt %, based on the total solid content of the delay film or the composition for the delay film. Within the above range, the glass transition temperature and melting temperature of the material forming the delay film can be reduced, and the film can be manufactured at a lower temperature and / or the film can be manufactured in a simplified manner.

[0140] The plasticizer may be at least one selected from the following: phosphate plasticizers, phthalate plasticizers, terephthalate plasticizers, trimellitate plasticizers, benzoate plasticizers, glycolate plasticizers, citrate plasticizers, polyol ester plasticizers, polyol plasticizers, polyester plasticizers and / or the like.

[0141] Non-limiting examples of glycolate-type plasticizers can include methylphthaloyl methyl glycolate, ethylphthaloyl ethyl glycolate, propylphthaloyl propyl glycolate, butylphthaloyl butyl glycolate, octylphthaloyl octyl glycolate, methylphthaloyl ethyl glycolate, ethylphthaloyl methyl glycolate, ethylphthaloyl propyl glycolate, methylphthaloyl butyl glycolate, ethylphthaloyl butyl glycolate, butylphthaloyl methyl glycolate, butylphthaloyl ethyl glycolate, propylphthaloyl butyl glycolate, butylphthaloyl propyl glycolate, methylphthaloyl octyl glycolate, ethylphthaloyl octyl glycolate, octylphthaloyl methyl glycolate, and octylphthaloyl ethyl glycolate.

[0142] According to one or more embodiments, the delay film can be manufactured by solution casting and stretching the composition for the delay film. According to one or more embodiments, the delay film can be manufactured by preparing a casting solution using the composition for the delay film itself, or adding a solvent to the composition for the delay film, applying the casting solution to a substrate, and drying the substrate to manufacture an unstretched film, and stretching the unstretched film in the machine direction of the unstretched film.

[0143] In one or more embodiments, the orientation direction of the main chain of the resin contained in the delay film can be adjusted by the viscosity of the composition for the delay film, the concentration of the resin in the composition for the delay film, etc., and the stretching direction and stretching ratio of the unstretched film when manufacturing the unstretched film.

[0144] In one or more embodiments, the slow axis of the retardation film may be about -5° to about +5°, for example, about -3° to about +3°, or about 0° relative to the light transmission axis of the polarizer. Within the above range, the effects of the present disclosure may be easily achieved.

[0145] In one or more embodiments, the slow axis of the retardation film may be substantially parallel to the lateral direction of the retardation film.

[0146] The polarizer may convert incident natural light or polarized light into linear polarized light in a specific direction. The polarizer may have a thickness of about 2 μm to about 30 μm, and in one or more embodiments, may have a thickness of about 4 μm to about 25 μm, and may be used in a polarizing plate within the range.

[0147] The polarizer can be manufactured from a film containing a polyvinyl alcohol-based resin as a main component by a suitable method known to those skilled in the art. For example, the polarizer can be a polarizer manufactured by iodine dyeing and stretching. The polarizer can have a light absorption axis and a light transmission axis orthogonal to the light absorption axis in an in-plane direction, and the light absorption axis can be a machine direction (machine direction, MD), and the light transmission axis can be a transverse direction (transverse direction, TD) (orthogonal to the MD).

[0148] In one or more embodiments, the polarizing plate may further include an upper protective layer located on an upper surface of the polarizer.

[0149] The upper protective layer may include one or more of an optically transparent protective coating and a protective film. The protective coating may include a coating formed of a composition comprising an active energy ray-curable compound. The protective film may be an optically transparent film, such as a film made of one or more resins selected from the following: a cellulose resin including triacetyl cellulose (TAC), a polyester resin including polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate and polybutylene naphthalate, a cyclic polyolefin resin, a polycarbonate resin, a polyether sulfone resin, a polysulfone resin, a polyamide resin, a polyimide resin, a polyolefin resin, a polyarylate resin, a polyvinyl alcohol resin, a polyvinyl chloride resin and a polyvinylidene chloride resin. In one or more embodiments, a TAC film and / or a PET film may be used.

[0150] The upper protective layer may have a thickness of about 0.1 μm to about 100 μm, for example, about 5 μm to about 70 μm, or about 15 μm to about 45 μm, and may be used in a polarizing plate within the range.

[0151] The upper protective layer may be attached to an adherend through an adhesive layer. If (for example, when) there is no problem with the function of the polarizing plate even if the upper protective layer is omitted, the upper protective layer may not be provided.

[0152] In one or more embodiments, the polarizing plate may further include an adhesive layer on its lowermost surface. The adhesive layer is used to attach the polarizing plate to the panel. The adhesive layer may be formed of a suitable adhesive composition known to those skilled in the art.

[0153] Reference Figure 1 In one or more embodiments, the polarizing plate may include a polarizer 100, an upper protective layer 300 located on (e.g., laminated on) an upper surface of the polarizer 100, and a delay film 200 located on (e.g., laminated on) a lower surface of the polarizer 100.

[0154] Reference Figure 2 In one or more embodiments, the polarizing plate may include a polarizer 100, an upper protective layer 300 located on (e.g., laminated on) the upper surface of the polarizer 100, and a delay film 200 and a lower protective layer 400 sequentially located on (e.g., laminated on) the lower surface of the polarizer 100.

[0155] Optical display equipment

[0156] According to one or more embodiments, the optical display device may include a polarizing plate. The optical display device may include a liquid crystal display device. The polarizing plate may be included in the optical display device as a viewer-side polarizing plate. In one or more embodiments, the liquid crystal display device may be a liquid crystal display device in an in-plane switching (IPS), fringe field switching (FFS), advanced super dimension switching (ADS) or plane to line switching (PLS) mode as a homogeneous alignment mode.

[0157] According to one or more embodiments, a liquid crystal display device may include a liquid crystal panel, a viewer-side polarizing plate located on one side surface of the liquid crystal panel, and a light source-side polarizing plate located on the other side surface of the liquid crystal panel. The light absorption axis of the polarizer in the viewer-side polarizing plate may be substantially orthogonal to the light absorption axis of the polarizer in the light source-side polarizing plate. When the light absorption axis of the polarizer in the viewer-side polarizing plate is 0°, the light absorption axis of the polarizer in the light source-side polarizing plate may be 90°, and the rubbing direction of the liquid crystal in the liquid crystal panel may be 90°.

[0158] Hereinafter, the configuration and operation of the present disclosure will be described in more detail through exemplary embodiments of the present disclosure. However, these are merely presented as examples of the present disclosure and should not be interpreted as limiting the present disclosure in any way.

[0159] Example 1

[0160] An unstretched film was manufactured by a solution casting method using a composition for a retardation film (comprising a regioselectively substituted cellulose ester resin as a main component; Eastman Chemical Ltd.) comprising a regioselectively substituted cellulose ester resin (in the cellulose ester resin, the C2 substitution degree of the propionyl group was 0.26, the C3 substitution degree of the propionyl group was 0.34, the C6 substitution degree of the propionyl group was 0.53, the total substitution degree of the propionyl group was 2.33, and the substitution degree of the hydroxyl group was 1.87.). The manufactured unstretched film was stretched at a stretch ratio of 1.5 times in the machine direction of the unstretched film to manufacture a retardation film (in-plane retardation at a wavelength of 550 nm: 270 nm; biaxiality: 0.6; thickness: 56 μm; nx=1.5323; ny=1.5275; and nz=1.5294).

[0161] A polyvinyl alcohol-based film (TS#20, Kuraray, Japan, thickness before stretching: 20 μm) was uniaxially stretched 6 times in a machine direction of the film in an iodine aqueous solution at 55° C. to produce a polarizer having a light transmittance of 45%.

[0162] The polarizing plate is manufactured by laminating a polyethylene terephthalate (PET) film and an antireflection layer on the upper surface of the manufactured polarizer and laminating the manufactured retardation film on the lower surface of the polarizer. In the manufactured polarizing plate, the main chain orientation direction of the cellulose ester resin selectively substituted in the retardation film forms an angle of 0° with respect to the light absorption axis of the polarizer (the mechanical direction of the polarizer) .

[0163] Instance 2 to Instance 5

[0164] A polarizing plate was manufactured in substantially the same manner as in Example 1, except that the retardation film was changed by using a regioselectively substituted cellulose ester-based resin having a changed degree of substitution, changing the solution casting conditions, and changing the stretching ratio.

[0165] Comparative Examples 1 to 4

[0166] A polarizing plate was manufactured in substantially the same manner as in Example 1, except that the retardation film was changed by using a regioselectively substituted cellulose ester-based resin having a changed degree of substitution, changing the solution casting conditions, and changing the stretching ratio.

[0167] The following physical properties were evaluated using each of the polarizing plates of Examples and Comparative Examples, and are shown in Table 1.

[0168] (1) Optical properties of retardation films: The optical properties of each of the retardation films were measured using AxoScan.

[0169] (2) Angle: The angle formed by the main chain orientation direction of the cellulose ester resin in the delay film relative to the light absorption axis of the polarizer in the polarizing plate (the mechanical direction of the polarizer) is calculated by measuring the light absorption axis of the polarizer by Aike scanning when the delay film and the polarizer are separated, and measuring the main chain orientation direction of the cellulose ester resin by X-ray diffraction (XRD) method, as the relative angle between the light absorption axis and the main chain orientation direction.

[0170] (3) Maximum light transmittance (unit: %): In a Samsung Electronics television (TV) model provided with an IPS liquid crystal panel, the polarizing plate manufactured in each of the examples and comparative examples was attached and operated instead of the viewer-side polarizing plate. The maximum light transmittance in the black state at all viewing angles was calculated using the Extended Jones Matrix method using the TECHWIZ 1D (SANAI SYSTEM, South Korea) simulation software program. However, the reduction in light transmittance due to the color filter inside the panel was excluded from the above calculation. A lower maximum light transmittance means that light leakage can be prevented and visibility can be improved.

[0171] (4) Black visibility and color: In a Samsung Electronics TV model provided with an IPS liquid crystal panel, the polarizing plate manufactured in each of the examples and comparative examples was attached and operated instead of the viewer-side polarizing plate. In addition, black visibility and color were evaluated using a visual evaluation method.

[0172] Table 1

[0173]

[0174] *The retardation films of the examples and comparative examples each satisfy nx>nz>ny at a wavelength of 550 nm.

[0175] As shown in Table 1, the polarizing plate of the present disclosure includes a single-layer retardation film, and provides the effects of improving visibility at all viewing angles, minimizing color changes, and improving light leakage by reducing the maximum light transmittance at all viewing angles in a black state. On the other hand, as shown in Table 1, the above effects of the polarizing plate of the comparative example having a retardation film that does not satisfy the optical properties of the present disclosure are reduced compared to the examples.

[0176] According to one or more embodiments, a polarizing plate having a single-layer retardation film is provided, which improves visibility at all azimuth angles and minimizes color change.

[0177] According to one or more embodiments, there is provided a polarizing plate having a single-layer retardation film and reducing light transmittance at all azimuth angles.

[0178] According to one or more embodiments, a polarizing plate having an excellent thickness thinning effect by having a single-layer retardation film is provided.

[0179] According to one or more embodiments, a polarizing plate having a single-layer retardation film and enabling roll-to-roll manufacturing is provided.

[0180] In the present disclosure, it should be understood that the terms “comprise(s) / comprising”, “include(s) / including” or “have / has / having” specify the presence of stated features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0181] Throughout this disclosure, when it is mentioned that a component such as a layer, film, region, or plate is placed "on" another component, it should be understood that the component can be directly on the other component or another component can be sandwiched therebetween. In some embodiments, "directly on" may mean that there are no additional layers, films, regions, plates, etc. between the layer, film, region, plate, etc. and another part. For example, "directly on" may mean that two layers or two components are disposed without using an additional component such as an adhesive component therebetween.

[0182] In the present disclosure, although the terms "first", "second", etc. are used herein to describe one or more elements, components, regions and / or layers, these elements, components, regions and / or layers should not be limited by these terms. These terms are only used to distinguish one component from another component.

[0183] The terms "substantially," "about," or similar terms utilized herein are used as terms of approximation rather than terms of degree, and are intended to account for the inherent deviations in measured or calculated values ​​that one of ordinary skill in the art would recognize. As used herein, "about" is inclusive of the stated value and means that the particular value is within an acceptable range of deviation as determined by one of ordinary skill in the art, taking into account the measurement in question and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "about" may mean within one or more standard deviations, or within ±30%, 20%, 10%, or 5% of the stated value.

[0184] Any numerical range listed herein is intended to include all subranges of the same numerical precision included in the listed range. For example, the range of "1.0 to 10.0" is intended to include all subranges between the listed minimum value of 1.0 and the listed maximum value of 10.0 (and including the two values), i.e., having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as (for example) 2.4 to 7.6. Any maximum numerical limit listed herein is intended to include all lower numerical limits included therein, and any minimum numerical limit listed in the present disclosure is intended to include all higher numerical limits included therein. Therefore, the applicant reserves the right to modify the disclosure (including the claims) to explicitly list any subranges included in the range explicitly listed herein.

[0185] In the context of the present disclosure, and unless defined otherwise, the terms “use”, “using” and “used” may be considered synonymous with the terms “utilize”, “utilizing” and “utilized”, respectively.

[0186] The foregoing is an illustration of some embodiments of the present disclosure and should not be construed as limiting the present disclosure. Although some embodiments have been described, it will be readily understood by those skilled in the art that various modifications in the embodiments can be implemented without departing from the spirit and scope of the present disclosure. It should be understood that, unless otherwise specified, the description of features or aspects in each embodiment should generally be considered to be applicable to other similar features or aspects in other embodiments. Therefore, it is obvious to those of ordinary skill in the art that, unless otherwise specifically specified, the features, characteristics and / or elements described in conjunction with a particular embodiment may be used alone or in combination with the features, characteristics and / or elements described in conjunction with other embodiments. Therefore, it should be understood that the foregoing is an illustration of various exemplary embodiments and should not be construed as being limited to the specific embodiments disclosed herein, and various modifications to the disclosed embodiments and other exemplary embodiments are intended to be included in the spirit and scope of the present disclosure as defined in the appended claims and their equivalents.

Claims

1. A polarizing plate, comprising: Polarizer; as well as A retardation layer is located on the first surface of the polarizer, wherein the retardation layer comprises a retardation film satisfying nx>nz>ny at a wavelength of 550 nm, nx, ny and nz are respectively the refractive index of the retardation film in the slow axis direction, the refractive index of the retardation film in the fast axis direction and the refractive index of the retardation film in the thickness direction at a wavelength of 550 nm, The orientation direction of the main chain of the resin contained in the retardation film is -5° to +5° relative to the light absorption axis of the polarizer, and The retardation film has a biaxiality of 0.3 to 0.7 at a wavelength of 550 nm. 2 . The polarizing plate according to claim 1 , wherein the retardation film is a single-layer retardation film. 3 . The polarizing plate according to claim 1 , wherein the retardation film has an in-plane retardation of 220 nm to 300 nm at a wavelength of 550 nm.

4. The polarizing plate according to claim 1, wherein in the retardation film, the value of Expression 1 is 0.8 to 1.2, and the value of Expression 2 is 0.9 to 1.1, Expression 1 Re(450nm) / Re(550nm) Expression 2 Re(650nm) / Re(550nm) In Expression 1 and Expression 2, Re(450 nm), Re(550 nm), and Re(650 nm) are the in-plane retardation of the retardation film at wavelengths of 450 nm, 550 nm, and 650 nm, respectively, and the unit of the in-plane retardation is nm. 5 . The polarizing plate according to claim 1 , wherein a slow axis of the retardation film is −5° to +5° with respect to a light transmission axis of the polarizer. The polarizing plate according to claim 1 , wherein a slow axis of the retardation film is parallel to a transverse direction of the retardation film. The polarizing plate according to claim 1 , wherein the retardation film is stretched in a machine direction. 8 . The polarizing plate according to claim 1 , wherein (nx−ny) is 0.0022 to 0.0075, and (nx−nz) is 0.00066 to 0.00525. 9 . The polarizing plate of claim 1 , wherein nx is from 1.500 to 1.710, ny is from 1.480 to 1.700, and nz is from 1.500 to 1.

705. 10 . The polarizing plate according to claim 1 , wherein the resin is a main component of the retardation film. 11 . The polarizing plate according to claim 1 , wherein the resin is a cellulose ester-based resin.

12. The polarizing plate according to claim 11, wherein in the cellulose ester resin, at least a portion of hydrogen in each of the hydroxyl groups of C2, C3 and C6 of cellulose is regioselectively substituted by one or more selected from the following: a plurality of aromatic -CO- groups as substituents and a plurality of first unsaturated or saturated (C 1-6 )alkyl-CO-group.

13. The polarizing plate according to claim 12, wherein the cellulose ester resin has a hydroxyl substitution degree of 0.2 to 2.0, a substitution degree of 0.15 to 0.8 at C2, a substitution degree of 0.05 to 0.6 at C3, and a substitution degree of 0.05 to 0.6 at C6, and a total substitution degree of 0.25 to 2.

5. 14 . The polarizing plate according to claim 1 , wherein the retardation layer consists of the retardation film. 15 . The polarizing plate according to claim 1 , wherein the retardation layer has a thickness of 40 μm to 100 μm. 16 . The polarizing plate according to claim 1 , wherein a protective layer is located on a second surface of the polarizer, the second surface being opposite to the first surface of the polarizer.

17. An optical display device comprising the polarizing plate according to claim 1.

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