Polarizing plate and image display apparatus comprising same

Patent metadata

Field	Value
Publication number	US-9971067-B2
Application number	US-201415024706-A
Country	US
Kind code	B2
Filing date	Sep 19, 2014
Priority date	Sep 30, 2013
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

The present invention relates to a polarizing plate including: a polarizer; and a protective layer formed on at least one surface of the polarizer, in which the protective layer is a cured product of a radical curable composition including: (A) an acid anhydride-based compound having at least one unsaturated double bond between carbons; (B) a vinyl-based compound having at least one electron donor group; (C) a radical initiator; and (D) a cation generator, and an image display device including the same.

First claim

The invention claimed is:

1. A polarizing plate comprising:
a polarizer; and
a protective layer formed on at least one surface of the polarizer,
wherein the protective layer is a cured product of a radical curable composition comprising: (A) an acid anhydride-based compound having at least one unsaturated double bond between carbons; (B) a vinyl-based compound having at least one electron donor group; (C) a radical initiator; and (D) a cation generator.

2. The polarizing plate of claim 1 , wherein in the polarizer and the protective layer, adhesive strength is secured through a covalent bond generated as a result of an esterification reaction between a hydroxy group of the polarizer and an acid anhydride group of the protective layer.

3. The polarizing plate of claim 1 , wherein in terms of a content of the acid anhydride-based compound and the vinyl-based compound, a blending equivalent ratio represented by the following Equation (1) is 0.8 to 1.0;
Blending equivalent ratio= M/N,   Equation (1):

wherein in Equation (1), M is the number of unsaturated double bonds between carbons, which are capable of participating in a polymerization in a molecule comprising an acid anhydride group comprised in the acid anhydride-based compound; and N is the number of unsaturated double bonds between carbons, which are capable of participating in a polymerization in a molecule comprised in the vinyl-based compound.

4. The polarizing plate of claim 1 , wherein the acid anhydride-based compound is one or more compounds selected from the group consisting of compounds represented by the following [Formula I] to [Formula IV]:

wherein in [Formula I], R 1 is a (meth)acryloyl group, a (meth)acryloylalkyl group, or a (meth)acryloyloxy alkyl group; R 2 is a halogen atom or a C 1˜10 alkyl group; a is an integer of 1 and 2; b is an integer of 0 to 2; and X 1 is a single bond, —O—, —CO—, —COO—, or —OCO—,

wherein in [Formula II], R 3 to R 5 are each independently hydrogen or a halogen atom; or a C 1˜10 alkyl group, a C 4˜14 cycloalkyl group, a C 6˜14 aryl group or a combination thereof,

wherein in [Formula III], R 6 and R 7 are each independently hydrogen or a halogen atom; or a C 1˜10 alkyl group, a C 4˜14 cycloalkyl group, a C 6˜14 aryl group or a combination thereof, and

wherein in [Formula IV], R 8 to R 11 are each independently hydrogen or a halogen atom; or a C 1˜10 alkyl group, a C 4˜14 cycloalkyl group, a C 6˜14 aryl group or a combination thereof.

5. The polarizing plate of claim 1 , wherein the electron donor group of the vinyl-based compound is a functional group represented by the following [Formula A] or [Formula B]:

wherein in [Formula A], R 12 is hydrogen or a C 1˜10 alkyl group, and

wherein in [Formula B], R 13 is hydrogen or a C 1˜10 alkyl group.

6. The polarizing plate of claim 1 , wherein the vinyl-based compound is a compound represented by the following [Formula V]:

wherein in [Formula V], R 14 is hydrogen or a C 1˜10 alkyl group; R 15 is a c-valent C 1˜10 aliphatic chain, a C 4˜14 aliphatic ring, a C 6˜14 aromatic ring, or a combination thereof; c is an integer of 1 to 4; and X 2 is —O— or —OCO—.

7. The polarizing plate of claim 1 , wherein the radical curable composition further comprises a radical polymerizable compound represented by the following [Formula VI]:

wherein in [Formula VI], R 16 is an ester group (—COO—), an amide group (—CON—), or a thioate group (—COS—); R 17 is a C 1˜10 alkyl group, a C 4˜10 cycloalkyl group, or a combination thereof, and in this case, R 17 has at least one hydroxy substituent in a molecule thereof; and R 18 is hydrogen, or a C 1˜10 alkyl group.

8. The polarizing plate of claim 7 , wherein the radical curable composition comprises 1 to 50 parts by weight of the acid anhydride-based compound and the vinyl-based compound; 40 to 97 parts by weight of the radical polymerizable compound; 1 to 10 parts by weight of the radical initiator; and 1 to 10 parts by weight of the cation generator based on 100 parts by weight of the entire composition.

9. The polarizing plate of claim 1 , wherein the radical curable composition after curing has a glass transition temperature of 60° C. or more.

10. The polarizing plate of claim 1 , wherein the radical curable composition has a viscosity of 10 to 200 cP.

11. The polarizing plate of claim 1 , wherein the protective film has a thickness of 0.5 to 20 μm.

12. The polarizing plate of claim 1 , wherein a protective film is further attached, through an adhesive layer, to a surface opposite to a surface of the polarizer, on which said protective layer is formed previously.

13. The polarizing plate of claim 1 , further comprising an adhesion layer at an upper portion of the protective layer.

14. The polarizing plate of claim 1 , wherein the polarizer is a polyvinyl alcohol-based film comprising iodine or a dichroic dye.

15. An image display device comprising the polarizing plate of claim 1 .

Assignees

• Lg Chemical Ltd

Inventors

• Park Kwang-Seung
• Lee Mi-Rin
• Park Jun-Wuk
• Huh Eun-Soo

Classifications

• G02B1/08

  made of polarising materials · CPC title

• G02B5/305

  including organic materials, e.g. polymeric layers · CPC title

• G02B1/14 Primary

  Protective coatings, e.g. hard coatings · CPC title