IP Library Granted Patent US 11,719,869
Granted Patent B2
US 11,719,869 · App. 16/770,813 · Granted Aug 8, 2023

Polarizing plate, polarizing plate-carrier film laminate, method for preparing polarizing plate-carrier film laminate, method for preparing polarizing plate, and active energy ray curable composition

Inventors: Mi So Lee (Daejeon, KR); Yoonkyung Kwon (Daejeon, KR); Jin Woo Kim (Daejeon, KR); Dong Uk Kim (Daejeon, KR)
Assignee: SHANJIN OPTOELECTRONICS (SUZHOU) CO., LTD.
G02B5/305B32B7/023B32B7/12B32B27/18B32B27/306B32B27/38B32B37/10B32B37/1284B32B38/10G02B1/18G02F1/133528B32B2037/243B32B2305/72B32B2307/42
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Quick Facts
Patent No.
US 11,719,869
App. No.
16/770,813
Granted
Aug 8, 2023
Kind
B2
Abstract

A polarizing plate and a polarizing plate-carrier film laminate are provided. A method for manufacturing a polarizing plate-carrier film laminate and a method for manufacturing a polarizing plate using the same polarizing plate-carrier film laminate are also provided. An active energy ray curable composition for a polarizing plate protective layer is also provided.

Claims (30)

1. A method for manufacturing a polarizing plate-carrier film laminate, comprising:

supplying a carrier film to a first surface of a polarizer;

supplying a protective film to a second surface of the polarizer;

forming a protective layer by supplying an active energy ray curable composition between the polarizer and the carrier film wherein the active energy ray curable composition comprises a bisphenol F epoxy compound, an oxetane compound, a polyol compound, and an epoxy compound which does not contain an aromatic ring, or a cured product thereof; and wherein the active energy ray curable composition includes 18 parts by weight of the bisphenol F epoxy compound, 30 to 80 parts by weight of the oxetane compound, and 1 to 20 parts by weight of the polyol compound based on 100 parts by weight of the epoxy compound which does not contain an aromatic ring, wherein the bisphenol F epoxy compound has a viscosity at 25° C. of 2,000 cps to 5,000 cps;

forming a bonding agent layer by supplying a photocurable bonding agent composition between the polarizer and the protective film;

pressurizing a laminate in which the carrier film, the protective layer, the polarizer, the bonding agent layer, and the protective film are sequentially laminated by disposing a pair of pressurization means on opposing surfaces of the laminate; and

curing the protective layer and the bonding agent layer by irradiating the protective layer and the bonding agent layer with an active energy ray.

2. The method of claim 1 , wherein the active energy ray curable composition has a viscosity of 50 cps to 200 cps at room temperature.

3. A polarizing plate comprising:

a polarizer;

a bonding agent layer and a protective film sequentially provided on one surface of the polarizer; and

a protective layer which is directly attached to the other surface of the polarizer,

wherein the protective layer is a resin layer comprising an active energy ray curable composition comprising a bisphenol F epoxy compound, an oxetane compound, a polyol compound, and an epoxy compound which does not contain an aromatic ring, or a cured product thereof; and

wherein the active energy ray curable composition includes 18 parts by weight of the bisphenol F epoxy compound, 30 to 80 parts by weight of the oxetane compound, and 1 to 20 parts by weight of the polyol compound based on 100 parts by weight of the epoxy compound which does not contain an aromatic ring, wherein the bisphenol F epoxy compound has a viscosity at 25° C. of 2,000 cps to 5,000 cps.

4. The polarizing plate of claim 3 , wherein a bonding strength (X1) of the protective layer with respect to the polarizer is 4B or more when measured by an ASTM standard cross-cut tape test in accordance with D3359-87.

5. The polarizing plate of claim 3 , wherein an epoxy equivalent weight of the bisphenol F epoxy compound is 120 g/eq or more.

6. The polarizing plate of claim 3 , wherein the bisphenol F epoxy compound has a viscosity of 2,000 cps to 3,500 cps at 25° C.

7. The polarizing plate of claim 3 , wherein the protective layer has a thickness of 4 μm to 11 μm.

8. The polarizing plate of claim 3 , wherein the active energy ray curable composition has a glass transition temperature of 90° C. or more after curing.

9. The polarizing plate of claim 3 , wherein the polarizer is a polyvinyl alcohol-based film.

10. The polarizing plate of claim 3 , wherein a bonding strength (X1) of the protective layer with respect to the polarizer is 4B to 5B when measured by an ASTM standard cross-cut tape test in accordance with D3359-87.

11. The polarizing plate of claim 3 , wherein an epoxy equivalent weight of the bisphenol F epoxy compound is 120 g/eq to 500 g/eq.

12. The polarizing plate of claim 3 , wherein the active energy ray curable composition has a glass transition temperature from 100° C. to 150° C. after curing.

13. A polarizing plate-carrier film laminate comprising:

the polarizing plate according to claim 3 ; and

a carrier film on a surface opposite to a surface of the protective layer of the polarizing plate which is in contact with the polarizer.

14. The polarizing plate-carrier film laminate of claim 13 , wherein X2 calculated according to the following General Equation 1 is 0.95 to 1:

X 2=(Area of the remaining protective layer after the ASTM standard cross-cut tape test)/(Area of the entire peeled surface).   [General Equation 1]

15. The polarizing plate-carrier film laminate of claim 13 , wherein a peel strength (X3) of the protective layer with respect to the carrier film is 40 gf/5 cm or less.

16. A method for manufacturing a polarizing plate, comprising: peeling off the carrier film from the protective layer of the polarizing plate-carrier film laminate according to claim 13 .

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 30, 2023
From: SHANJIN OPTOELECTRONICS (SUZHOU) CO., LTD.
To: SHANJIN OPTOELECTRONICS (NANJING) CO., LTD.
Reel/Frame 065393/0902 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 20, 2021
From: LG CHEM LTD.
To: SHANJIN OPTOELECTRONICS (SUZHOU) CO., LTD.
Reel/Frame 056316/0198 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 9, 2020
From: LEE, MI SO; KWON, YOONKYUNG; KIM, JIN WOO; KIM, DONG UK
To: LG CHEM, LTD.
Reel/Frame 052880/0375 →
Priority Claims (1)
KR 10-2017-0173268 · Dec 15, 2017 · national
Continuity (1)
Related Publication 20200393603A1 · Dec 17, 2020