CN-116547596-B - Polarizing plate and polarizing plate with phase difference layer

Abstract

Provided is a polarizing plate which is extremely thin and has excellent adhesion and curved surface following properties. The polarizing plate of the present application comprises a polarizing material and protective layers disposed on both sides of the polarizing material, wherein the protective layers comprise an epoxy resin having an aromatic skeleton and a diol skeleton, the epoxy resin has a glass transition temperature of 40 ℃ or less, and the polarizing plate has an elongation of 1.40mm or more in a puncture test.

Inventors

• MIWA KAZUYA
• Gao Yongxingyou

Assignees

• 日东电工株式会社

Dates

Publication Date

20260508

Application Date

20211228

Priority Date

20210208

Claims (6)

1. 1. A polarizing plate comprises a polarizer and protective layers disposed on both sides of the polarizer, The protective layer comprises an epoxy resin having an aromatic skeleton and a diol skeleton, the epoxy resin having a glass transition temperature of 40 ℃ or less, The polarizing plate has an elongation of 1.40mm or more in a puncture test, The protective layer is composed of a photocationally polymerized cured product of the epoxy resin or a solid product of a coating film of an organic solvent solution of the epoxy resin.
2. 2. The polarizing plate according to claim 1, wherein the polarizing material is composed of a polyvinyl alcohol resin film containing a dichroic substance, and an orientation function of the polyvinyl alcohol resin is 0.30 or less.
3. 3. The polarizing plate according to claim 1 or 2, which has a total thickness of 20 μm or less.
4. 4. The polarizing plate according to claim 1 or 2, which has a puncture strength of 300g or more.
5. 5. The polarizing plate according to claim 1 or 2, wherein the protective layer has a glass transition temperature of 0 ℃ or higher.
6. 6. A polarizing plate with a retardation layer comprising the polarizing plate according to any one of claims 1 to 5, a retardation layer, and a protective layer.

Description

Polarizing plate and polarizing plate with phase difference layer Technical Field The present invention relates to a polarizing plate and a polarizing plate with a retardation layer. Background In many image display devices (e.g., liquid crystal display devices and organic EL display devices), a polarizing plate is disposed on at least one side of a display unit due to an image forming method. In recent years, the reduction in thickness and flexibility of image display devices have been advanced, and along with this, the reduction in thickness of polarizing plates has been strongly desired. However, when the conventional thin polarizing plate is applied to a flexible image display device, there are problems in that the adhesion of the polarizing plate is reduced and the follow-up property of the polarizing plate to a curved surface is reduced. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2015-210474 Disclosure of Invention Problems to be solved by the invention The present invention has been made to solve the above-described conventional problems, and a main object thereof is to provide a polarizing plate which is extremely thin, has excellent adhesion, and has excellent curved surface following properties. Solution for solving the problem The polarizing plate of the present invention comprises a polarizing material and protective layers disposed on both sides of the polarizing material, wherein the protective layers comprise an epoxy resin having an aromatic skeleton and a diol skeleton, the epoxy resin has a glass transition temperature of 40 ℃ or less, and the elongation of the polarizing plate at the time of a puncture test is 1.40mm or more. In one embodiment, the polarizer is made of a polyvinyl alcohol resin film containing a dichroic material, and the orientation function of the polyvinyl alcohol resin film is 0.30 or less. In one embodiment, the protective layer is composed of a photocationally polymerized cured product of the epoxy resin or a solid product of a coating film of an organic solvent solution of the epoxy resin. In 1 embodiment, the total thickness of the polarizing plate is 20 μm or less. In 1 embodiment, the puncture strength of the polarizing plate is 300g or more. In 1 embodiment, the protective layer has a glass transition temperature of 0 ℃ or higher. In another aspect of the present invention, a polarizing plate with a retardation layer is provided. The polarizing plate with a retardation layer includes a retardation layer, the polarizer, and the protective layer. ADVANTAGEOUS EFFECTS OF INVENTION According to the present invention, the protective layer disposed on both sides of the polarizer includes an epoxy resin having an aromatic skeleton and a diol skeleton, and the glass transition temperature of the epoxy resin is 40 ℃ or less, whereby a polarizing plate having excellent adhesion and excellent curved surface following property despite being extremely thin can be obtained. Drawings Fig. 1 is a schematic cross-sectional view of a polarizing plate according to 1 embodiment of the present invention. Detailed Description A. Outline of polarizing plate Fig. 1 is a schematic cross-sectional view of a polarizing plate according to 1 embodiment of the present invention. The polarizing plate 100 illustrated in the figure includes a polarizer 10 and protective layers 20 and 30 disposed on both sides of the polarizer 10. When the polarizing plate 100 is applied to an image display device, it may be disposed on the visual recognition side of the display unit or on the opposite side (back side) to the visual recognition side. The polarizing plate may be elongated or sheet-like. When the polarizing plate is elongated, it is preferable that the polarizing plate be wound in a roll shape. Typically, the polarizing plate has an adhesive layer as an outermost layer on one side, and can be attached to the display unit. The surface protective film and/or the carrier film may be temporarily adhered to the polarizing plate in a releasable manner, as necessary, and the polarizing plate may be reinforced and/or supported. In the case where the polarizing plate includes an adhesive layer, the separator is temporarily adhered to the surface of the adhesive layer in a releasable manner, the adhesive layer is protected until before actual use, and the polarizing plate can be rolled up. In an embodiment of the present invention, the protective layer includes an epoxy resin having an aromatic skeleton and a diol skeleton, and the epoxy resin has a glass transition temperature of 40 ℃ or less. With such a configuration, a polarizing plate excellent in adhesion and curved surface following property can be realized. The protective layer is preferably composed of a photo-cationic cured product of an epoxy resin having an aromatic skeleton and a diol skeleton or a cured product of a coating film of an organic solvent solution of the epoxy resin. With suc