IP Library Granted Patent US 10,983,391
Granted Patent B2
US 10,983,391 · App. 16/619,689 · Granted Apr 20, 2021

Polarizing plate with retardation layer and image display device

Inventors: Takeharu Kitagawa (Ibaraki, JP); Hirofumi Katami (Ibaraki, JP); Shusaku Goto (Ibaraki, JP)
Assignee: NITTO DENKO CORPORATION
G02F1/133528G02B5/3083G02F1/133634C09J7/29G02F2001/133637G02F2001/133638
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Quick Facts
Patent No.
US 10,983,391
App. No.
16/619,689
Granted
Apr 20, 2021
Kind
B2
Abstract

There is provided a polarizing plate with a retardation layer that can achieve an image display apparatus having excellent durability and excellent weatherability, and having an excellent hue. A polarizing plate with a retardation layer according to an embodiment of the present invention includes in this order: a polarizing plate including a protective layer and a polarizer; a retardation layer; and a pressure-sensitive adhesive layer. The protective layer has a light transmittance at a wavelength of 380 nm of 10% or less. The polarizing plate has a light transmittance at a wavelength of 380 nm of 5% or less. The pressure-sensitive adhesive layer has a light transmittance at a wavelength of 405 nm of 5% or less. The polarizing plate with a retardation layer has a light transmittance at a wavelength of 405 nm of 3% or less.

Claims (42)

1. A polarizing laminate, comprising in this order:

a polarizing plate including a protective layer and a polarizer;

a retardation layer; and

a pressure-sensitive adhesive layer;

a conductive layer or an isotropic substrate with a conductive layer between the retardation layer and the pressure-sensitive adhesive layer,

wherein the protective layer has a light transmittance at a wavelength of 380 nm of 10% or less,

wherein the polarizing plate has a light transmittance at a wavelength of 380 nm of 5% or less,

wherein the pressure-sensitive adhesive layer has a light transmittance at a wavelength of 405 nm of 5% or less, and

wherein the polarizing laminate has a light transmittance at a wavelength of 405 nm of 3% or less.

2. The polarizing laminate according to claim 1 , wherein the retardation layer comprises a polycarbonate-based resin film.

3. The polarizing laminate according to claim 2 , further comprising another retardation layer between the retardation layer and the pressure-sensitive adhesive layer.

4. The polarizing laminate according to claim 1 , wherein the retardation layer comprises an alignment fixed layer of a liquid crystal compound.

5. The polarizing laminate according to claim 4 , wherein the retardation layer has a laminated structure of a first alignment fixed layer of a liquid crystal compound and a second alignment fixed layer of a liquid crystal compound.

6. The polarizing laminate according to claim 1 , wherein the polarizer has a thickness of 10 μm or less.

7. The polarizing laminate according to claim 1 , wherein the protective layer has a thickness of 30 μm or less.

8. The polarizing laminate according to claim 7 , wherein the protective layer has a moisture permeability of 20 g/m 2 ·24 h or less.

9. The polarizing laminate according to claim 1 , wherein the polarizing plate and the retardation layer are directly laminated.

10. The polarizing laminate according to claim 1 , wherein the polarizing plate has a reflection hue value b* of −1.5 or less.

11. The polarizing laminate according to claim 1 , wherein the polarizer has a crossed hue value “b” of −1.5 or less.

12. An image display apparatus, comprising the polarizing laminate of claim 1 .

13. A polarizing laminate, comprising in this order:

a polarizing plate including a protective layer and a polarizer;

a retardation layer;

another retardation layer; and

a pressure-sensitive adhesive layer,

wherein the retardation layer comprises a polycarbonate-based resin film, has a refractive index characteristics of nx>ny≥nz, has an Re(550) of from 80 nm to 200 nm, and has an Re(450)/Re(550) of 0.8 or more and less than 1,

wherein the another retardation layer has a refractive index characteristics of nz>nx=ny,

wherein an angle formed by a slow axis of the retardation layer and an absorption axis of the polarizer is from 38° to 52°,

wherein the protective layer is a laminate having an inner layer having a UV-absorbing ability and outer layers arranged on both sides of the inner layer, has a light transmittance at a wavelength of 380 nm of 10% or less, and has a moisture permeability of 20 g/m 2 ·24 h or less,

wherein the pressure-sensitive adhesive layer contains a UV absorber, and a dye compound whose absorption spectrum has a maximum absorption wavelength present in the wavelength region of from 380 nm to 430 nm, and has a light transmittance at a wavelength of 405 nm of 5% or less,

wherein the polarizing plate has a light transmittance at a wavelength of 380 nm of 5% or less, and

wherein the polarizing laminate has a light transmittance at a wavelength of 405 nm of 3% or less.

14. A polarizing laminate, comprising in this order:

a polarizing plate including a protective layer and a polarizer;

a retardation layer; and

a pressure-sensitive adhesive layer,

wherein the retardation layer has a laminated structure of a first alignment fixed layer of a liquid crystal compound and a second alignment fixed layer of a liquid crystal compound, one of the first alignment fixed layer and the second alignment fixed layer functions as a λ/4 plate, and the other functions as a λ/2 plate,

wherein an angle formed by a slow axis of the first alignment fixed layer and an absorption axis of the polarizer is about 15°, and an angle formed by a slow axis of the second alignment fixed layer and the absorption axis of the polarizer is about 75°,

wherein the protective layer is a laminate having an inner layer having a UV-absorbing ability and outer layers arranged on both sides of the inner layer, has a light transmittance at a wavelength of 380 nm of 10% or less, and has a moisture permeability of 20 g/m 2 ·24 h or less,

wherein the pressure-sensitive adhesive layer contains a UV absorber, and a dye compound whose absorption spectrum has a maximum absorption wavelength present in the wavelength region of from 380 nm to 430 nm, and has a light transmittance at a wavelength of 405 nm of 5% or less,

wherein the polarizing plate has a light transmittance at a wavelength of 380 nm of 5% or less, and

wherein the polarizing laminate has a light transmittance at a wavelength of 405 nm of 3% or less.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 5, 2019
From: KITAGAWA, TAKEHARU; KATAMI, HIROFUMI; GOTO, SHUSAKU
To: NITTO DENKO CORPORATION
Reel/Frame 051193/0471 →
Priority Claims (1)
JP JP2017-114212 · Jun 9, 2017 · national
Continuity (1)
Related Publication 20200142255A1 · May 7, 2020