IP Library Granted Patent US 8,994,899
Granted Patent B2
US 8,994,899 · App. 13/353,395 · Granted Mar 31, 2015

Polarizing plate comprising a polyethylene terephthalate film having an in-plane phase difference and a coating layer having a haze value and liquid crystal display provided with the same

Inventors: So-Hee Yu (Uiwang-si, KR); Tae-Hwan Kwon (Uiwang-si, KR); Jae-Bin Song (Uiwang-si, KR); Hae-Ryong Chung (Uiwang-si, KR)
Assignee: Cheil Industries, Inc.
G02B5/305G02F1/133528G02F1/13363
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Quick Facts
Patent No.
US 8,994,899
App. No.
13/353,395
Filed
Jan 19, 2012
Granted
Mar 31, 2015
Kind
B2
Art Unit
2871
USPC
349/96
Abstract

A polarizing plate includes a polarizer, a thin film on the polarizer, the thin film having an in-plane phase difference (Ro) of about 500 nm to about 3000 nm, and a coating layer disposed on one side of the thin film and having a haze value of about 15% to about 35%.

Claims (36)

1. A polarizing plate, comprising:

a polarizer;

a polyethylene terephthalate film on the polarizer, the polyethylene terephthalate film having an in-plane phase difference (Ro) of about 500 nm to about 3000 nm; and

a coating layer disposed on one side of the polyethylene terephthalate film and having a haze value of about 15% to about 35%.

2. The polarizing plate as claimed in claim 1 , further comprising an adhesive layer interposed between the polarizer and the polyethylene terephthalate film, wherein:

the adhesive layer is formed of an adhesive including polyvinyl alcohol and a cross-linking agent,

the cross-linking agent includes a compound with an aldehyde group, and

the cross-linking agent is included in an amount of about 0.5 wt % to about 1.5 wt % based on the total amount of polyvinyl alcohol.

3. The polarizing plate as claimed in claim 2 , wherein the cross-linking agent includes a polyethylene imine, glyoxal, or a combination thereof.

4. The polarizing plate as claimed in claim 2 , further comprising at least one of:

a first auxiliary adhesive layer interposed between the polyethylene terephthalate film and the adhesive layer, the first auxiliary adhesive layer including a polyester-based resin, a polyvinyl acetate-based resin, or a combination thereof; and

a second auxiliary adhesive layer interposed between the polyethylene terephthalate film and the coating layer, the second auxiliary adhesive layer including a polyester-based resin, a polyvinyl acetate-based resin, or a combination thereof.

5. The polarizing plate as claimed in claim 1 , wherein the polyethylene terephthalate film has a thickness of about 25 μm to about 60 μm.

6. The polarizing plate as claimed in claim 1 , wherein the polyethylene terephthalate film includes an ultraviolet (UV) absorber, and has transmittance of less than about 10% at about 380 nm.

7. A liquid crystal display (LCD) including the polarizing plate as claimed in claim 1 disposed at a front side thereof.

8. A liquid crystal display (LCD), comprising:

a liquid crystal panel, the liquid crystal panel including first and second substrates facing each other, and including a liquid crystal layer disposed between the first and second substrates;

a backlight part configured to supply light to a back side of the liquid crystal panel;

a first polarizing plate positioned at a front side of the liquid crystal panel, the first polarizing plate including:

a polarizer,

a polyethylene terephthalate film on the polarizer, the polyethylene terephthalate film having an in-plane phase difference (Ro) of about 500 nm to about 3000 nm, and

a coating layer disposed on one side of the polyethylene terephthalate film and having a haze value of about 15% to about 35%; and

a second polarizing plate positioned between the liquid crystal panel and the backlight part.

9. The LCD as claimed in claim 8 , further comprising an adhesive layer interposed between the polarizer and the polyethylene terephthalate film, wherein:

the adhesive layer is formed of an adhesive including polyvinyl alcohol and a cross-linking agent,

the cross-linking agent includes a compound having an aldehyde group, and

the cross-linking agent is included in an amount of about 0.5 wt % to about 1.5 wt % based on the total amount of polyvinyl alcohol.

10. The LCD as claimed in claim 9 , wherein the cross-linking agent includes a polyethylene imine, glyoxal, or a combination thereof.

11. The LCD as claimed in claim 9 , further comprising at least one of:

a first auxiliary adhesive layer interposed between the polyethylene terephthalate film and the adhesive layer, the first auxiliary adhesive layer including a polyester-based resin, a polyvinyl acetate-based resin, or a combination thereof; and

a second auxiliary adhesive layer interposed between the polyethylene terephthalate film and the coating layer, the second auxiliary adhesive layer including a polyester-based resin, a polyvinyl acetate-based resin, or a combination thereof.

12. The LCD as claimed in claim 8 , wherein the polyethylene terephthalate film has a thickness of about 25 μm to about 60 μm.

13. The LCD as claimed in claim 8 , wherein the polyethylene terephthalate film includes an ultraviolet (UV) absorber with transmittance of less than about 10% at about 380 nm.

14. The LCD as claimed in claim 8 , wherein the LCD has a TN mode, and further comprises a WV compensation film positioned on a back side of the polyethylene terephthalate film, the WV compensation film including a discotic liquid crystal.

15. The LCD as claimed in claim 8 , wherein the LCD has a VA mode, and further comprises a drawn TAC-based compensation film positioned on a back side of the polyethylene terephthalate film.

16. The LCD as claimed in claim 8 , wherein the LCD is a horizontal electric field type, and further comprises an A plate, a C plate, or a mixed compensation film thereof on a back side of the polyethylene terephthalate film.

Assignments (4)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 4, 2026
From: WUXI HENGXIN OPTOELECTRONIC MATERIALS CO., LTD.
To: HOARDSUN HENGXIN(WUXI) MATERIALS CO., LTD.
Reel/Frame 075049/0450 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 14, 2025
From: SAMSUNG SDI CO., LTD.
To: WUXI HENGXIN OPTOELECTRONIC MATERIALS CO., LTD.
Reel/Frame 073062/0496 →
MERGER Recorded Jun 16, 2025
From: CHEIL INDUSTRIES INC.
To: SAMSUNG SDI CO., LTD.
Reel/Frame 071636/0099 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 19, 2012
From: YU, SO-HEE; KWON, TAE-HWAN; SONG, JAE-BIN; CHUNG, HAE-RYONG
To: CHEIL INDUSTRIES, INC.
Reel/Frame 027558/0169 →
Priority Claims (2)
KR 10-2009-0072156 · Aug 5, 2009 · national
KR 10-2010-0072454 · Jul 27, 2010 · national
Continuity (2)
Continuation PCTKR2010004993 · Jul 29, 2010
Related Publication 20120113356A1 · May 10, 2012