CN-122018069-A - Polarizing plate and optical display device

Abstract

The invention provides a polarizing plate and an optical display device comprising the same, wherein the polarizing plate comprises a polarizer, a polarizer protection layer and a lamination body of a positive A layer and a positive C layer, wherein the polarizer protection layer and the lamination body are sequentially laminated from the polarizer on one surface of the polarizer, the polarizer protection layer is an anisotropic optical layer, the in-plane retardation (Re) is more than 10nm and the biaxial degree (NZ) is more than 0.9 and less than or equal to 1.2 under the wavelength of 550nm, and the slow axis of the polarizer protection layer is parallel to the light absorption axis of the polarizer.

Inventors

• Pu Zhihuan
• JIN FENGCHUN
• Bian Bingzhou
• Jin Runding
• GUO DAXI
• Cui Hengzhun
• Pu Yien

Assignees

• 昊盛恒新(无锡)材料有限公司

Dates

Publication Date

20260512

Application Date

20260327

Priority Date

20250327

Claims (10)

1. 1. A polarizing plate includes a polarizer, a polarizer protective layer laminated in this order from the polarizer on one surface of the polarizer, and a laminate of a positive A layer and a positive C layer, The polarizer protective layer is an anisotropic optical layer, The polarizer protective layer has an in-plane retardation Re of 10nm or more and a biaxial degree NZ of 0.9 or more and 1.2 or less at a wavelength of 550nm, The slow axis of the polarizer protective layer is parallel to the light absorption axis of the polarizer.
2. 2. The polarizing plate according to claim 1, wherein the polarizer protective layer has an in-plane retardation of 10 to 1000nm at a wavelength of 550 nm.
3. 3. The polarizing plate according to claim 1, wherein a slow axis of the polarizer protective layer is parallel to a mechanical direction of the polarizer protective layer.
4. 4. The polarizing plate according to claim 1, wherein the polarizer protective layer is a polyester-based, polymethyl methacrylate-based or cyclic olefin polymer-based film.
5. 5. The polarizing plate according to claim 1, wherein the polarizer protective layer has a thickness of 20 μm or less.
6. 6. The polarizing plate according to claim 1, wherein the positive a layer is a liquid crystal layer and the positive C layer is a liquid crystal layer.
7. 7. The polarizing plate according to claim 1, wherein the polarizer protective layer, the positive a layer, and the positive C layer are laminated in this order from the polarizer.
8. 8. The polarizing plate according to claim 1, wherein the positive C layer has a thickness direction retardation of-150 nm to-50 nm at a wavelength of 550 nm.
9. 9. The polarizing plate according to claim 1, wherein the positive a layer has an in-plane retardation of 100nm to 160nm at a wavelength of 550 nm.
10. 10. An optical display device comprising the polarizing plate according to any one of claims 1 to 9.

Description

Polarizing plate and optical display device The present application claims priority from korean patent office, application No. 10-2025-0039485, korean patent application No. 3/27 of 2025 entitled "polarizing plate and optical display device", the entire contents of which are incorporated herein by reference. Technical Field The present invention relates to a polarizing plate and an optical display device. Background The liquid crystal display apparatus and the organic light emitting device display apparatus each include a polarizing plate. In particular, since the organic light emitting device display apparatus includes the polarizing plate, reflection due to external light can be effectively removed, and thus a clear image quality can be achieved. The polarizing plate includes a polarizer and a retardation layer sequentially laminated on a lower surface of the polarizer. The retardation layer may be formed by applying a composition for a liquid crystal layer in the case of a liquid crystal layer, although a resin film may be used, and thus, the effect of thinning a polarizing plate can be provided. The polarizing plate may further include a protective film between the polarizer and the retardation layer. The protective film can improve the mechanical strength of the polarizing plate. In general, the protective film should not affect the optical effect of the retardation layer, and therefore an isotropic protective film is generally used. The isotropic protective film is a film having the same refractive index nx in the slow axis direction and the same refractive index ny in the fast axis direction at a wavelength of 550 nm. Therefore, the isotropic protective film is an unstretched protective film, and the thickness of the polarizing plate may be increased. The background of the invention is disclosed in Japanese laid-open patent No. 2006-251659 and the like. Disclosure of Invention Technical problem The purpose of the present invention is to provide a polarizing plate that provides the optical effect, barrier effect and thin effect of a phase difference layer. Another object of the present invention is to provide a polarizing plate that provides an optical effect, a barrier effect, and a thin effect of a laminate of a positive a layer and a positive C layer. Solution to the problem One aspect of the present invention is a polarizing plate. The polarizing plate includes a polarizer, and a polarizer protective layer and a laminate of a positive A layer and a positive C layer laminated in this order from the polarizer on one surface of the polarizer, wherein the polarizer protective layer is an anisotropic optical layer, and has an in-plane retardation (Re) of 10nm or more and a biaxial degree (NZ) of 0.9 or more and 1.2 or less at a wavelength of 550nm, and a slow axis of the polarizer protective layer is parallel to a light absorption axis of the polarizer. Another aspect of the present invention is an optical display device. The optical display device includes the polarizing plate of the present invention. Effects of the invention The polarizing plate of the present invention, although the protective layer of the polarizer has anisotropy, does not adversely affect the optical performance of the polarizing plate, and provides an optical effect of a laminate of a positive a layer and a positive C layer while providing a blocking effect, thereby improving the reliability of the polarizing plate, and by providing a slim effect, it is possible to provide a slim effect of an optical display device. Drawings Fig. 1 is a sectional view of a polarizing plate according to an embodiment of the present invention. Fig. 2 is a cross-sectional view of a polarizing plate according to another embodiment of the present invention. Detailed Description The present invention is described in detail with reference to the accompanying drawings to enable those skilled in the art to easily practice the same. The present invention may be embodied in a variety of different forms and is not limited to the embodiments described herein. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The expression in the singular includes the expression in the plural unless the context clearly indicates otherwise. In the drawings, for the purpose of clearly explaining the present invention, parts not related to the explanation are omitted, and the same reference numerals are given to the same or similar constituent elements throughout the specification. The length and size of each component in the drawings are for the purpose of explaining the present invention, and the present invention is not limited to the length and size of each component described in the drawings. In the present specification, "upper" and "lower" are defined with reference to the drawings, and "upper" may be changed to "lower" and "lower" may be changed to "upper" depending on the view a