CN-114902097-B - Polarizing plate with retardation layer and image display device

Abstract

The invention provides a polarizing plate with a phase difference layer, which suppresses damage marks. A polarizing plate with a retardation layer comprises a polarizing plate (10) comprising a polarizer (11) and a protective layer (12) provided at least on the visible side of the polarizer (11), and a retardation layer (30) bonded to the opposite side of the polarizing plate (10) from the visible side via an adhesive layer (20). The thickness of the polarizer is 12 μm or less, and the residual depth of the adhesive layer under a load of 3N is 11 μm or less.

Inventors

• New land truth
• KATO MEGUMI
• NAKA KIYOSHI

Assignees

• 日东电工株式会社

Dates

Publication Date

20260505

Application Date

20201218

Priority Date

20191227

Claims (9)

1. 1. A polarizing plate with a retardation layer, comprising: Polarizing plate comprising polarizer and protective layer provided at least on visible side of the polarizer, and A retardation layer bonded to the opposite side of the polarizing plate from the viewing side via an adhesive layer, The thickness of the polarizer is 3-8 μm, The adhesive layer is composed of an acrylic adhesive composition, The acrylic pressure-sensitive adhesive composition comprises a (meth) acrylic polymer, wherein the (meth) acrylic polymer is contained in an amount of 50 wt% or more in the solid content of the pressure-sensitive adhesive composition, The (meth) acrylic polymer contains 20000/4203 wt% to 7 wt% of carboxyl group-containing monomer units and 0.05 wt% to 0.1 wt% of hydroxyl group-containing monomer units, The adhesive layer has a residual depth of 11 [ mu ] m or less when subjected to a load of 3N.
2. 2. The polarizing plate with a retardation layer as claimed in claim 1, wherein, The thickness of the adhesive layer is 6-15 mu m.
3. 3. The polarizing plate with a retardation layer as claimed in claim 1 or 2, wherein, The thickness of the protective layer on the visible side is 30 μm or more.
4. 4. The polarizing plate with a retardation layer as claimed in claim 1 or 2, wherein, The retardation layer exhibits refractive index characteristics of nx > nz > ny.
5. 5. The polarizing plate with a retardation layer as claimed in claim 4, wherein, The Nz coefficient of the phase difference layer is 0.3-0.7.
6. 6. The polarizing plate with a retardation layer as claimed in claim 4, wherein, The retardation layer has an in-plane retardation Re (550) of 250-350 nm, a thickness of 150 [ mu ] m or less, and a photoelastic coefficient of 1.0X10 -12 m 2 /N or more.
7. 7. The polarizing plate with a retardation layer as claimed in claim 4, wherein, The retardation layer contains a cyclic olefin resin.
8. 8. The polarizing plate with a retardation layer as claimed in claim 1 or 2, wherein, The slow axis of the phase difference layer forms an angle of 90 DEG + -7 DEG or 0 DEG + -7 DEG with the absorption axis of the polarizer.
9. 9. An image display device comprising the polarizing plate with a retardation layer according to any one of claims 1 to 8.

Description

Polarizing plate with retardation layer and image display device Technical Field The present invention relates to a polarizing plate with a retardation layer and an image display device. Background In image display devices (e.g., liquid crystal display devices, organic EL display devices, and quantum dot display devices), a polarizing plate is often disposed on at least one side of an image display unit due to the image formation method. In a polarizing plate disposed on the visible side of an image display device, a retardation film (polarizing plate with a retardation layer) may be laminated on the image display unit side for the purpose of preventing reflection of external light, reflection of background, improvement of hue, and the like. With the reduction in thickness of image display devices, there is also a strong demand for the reduction in thickness of polarizing plates with retardation layers. In order to cope with such a demand, the thickness of the polarizer is being reduced. However, it is difficult to handle a polarizing plate with a retardation layer including a thin polarizer, and for example, damage marks (typically, a plurality of minute cracks in a certain region) may be generated due to an external force caused by a handling error of an operator. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2013-200445 Disclosure of Invention Problems to be solved by the invention The present invention has been made to solve the above-described problems, and a main object of the present invention is to provide a polarizing plate with a retardation layer, in which a flaw mark is suppressed. Means for solving the problems The polarizing plate with a retardation layer according to an embodiment of the present invention includes a polarizing plate including a polarizer and a protective layer provided at least on a visible side of the polarizer, and a retardation layer bonded to an opposite side of the polarizing plate from the visible side via an adhesive layer. The thickness of the polarizer is 12 μm or less, and the residual depth of the adhesive layer under a load of 3N is 11 μm or less. In one embodiment, the thickness of the adhesive layer is 6 μm to 15 μm. In one embodiment, the thickness of the protective layer on the visible side is 30 μm or more. In one embodiment, the retardation layer exhibits refractive index characteristics of nx > nz > ny. In one embodiment, the Nz coefficient of the retardation layer is 0.3 to 0.7. In one embodiment, the retardation layer has an in-plane retardation Re (550) of 250nm to 350nm, a thickness of 150 μm or less, and a photoelastic coefficient of 1.0X10 -12m2/N or more. In one embodiment, the retardation layer includes a cyclic olefin resin. In one embodiment, the slow axis of the retardation layer is substantially orthogonal or substantially parallel to the absorption axis of the polarizer. According to other aspects of the present invention, an image display apparatus may be provided. The image display device includes the polarizing plate with a retardation layer. ADVANTAGEOUS EFFECTS OF INVENTION According to the embodiment of the present invention, by using the adhesive layer having a specific residual depth in the polarizing plate with the retardation layer including the thin polarizing plate, the polarizing plate with the retardation layer in which the damage trace is suppressed can be realized. Drawings Fig. 1 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to an embodiment of the present invention. Symbol description 10. Polarizing plate 11. Polarizer 12. Protective layer 20. Adhesive layer 30. Phase difference layer 100. Polarizing plate with phase difference layer Detailed Description Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments. (Definition of terms and symbols) The terms and symbols in the present specification are defined as follows. (1) Refractive index (nx, ny, nz) "Nx" is a refractive index in a direction in which the refractive index in the plane reaches the maximum (i.e., the slow axis direction), "ny" is a refractive index in a direction orthogonal to the slow axis in the plane (i.e., the fast axis direction), and "nz" is a refractive index in the thickness direction. (2) In-plane phase difference (Re) "Re (λ)" is the in-plane retardation measured at 23℃with light of wavelength λnm. For example, "Re (550)" is the in-plane retardation measured at 23℃with light having a wavelength of 550 nm. When the thickness of the layer (film) is d (nm), re (λ) can be obtained by the formula Re (λ) = (nx-ny) x d. (3) Retardation in thickness direction (Rth) "Rth (λ)" is a phase difference in the thickness direction measured at 23 ℃ with light of wavelength λnm. For example, "Rth (550)" is a phase difference in the thickness direction measured at 23 ℃ with light having a wavelength