Acrylic adhesive compositions for polarizing film and the polarizer film using the same

• US 6,800,366 B2
• Filed: 08/15/2002
• Issued: 10/05/2004
• Est. Priority Date: 12/21/2000
• Status: Active Grant

• Current Assignee: Shanjin Optoelectronics Company Limited
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Hwang, In-Seok, Sergey, Belyaev, Nikolay, Malimonenko, Chang, Suk-Ky, Sohn, Hye-Won, Sohn, Seung-Man, Han, Sang-Eon, Han, In-Cheon
• Primary Examiner(s): Buttner, David J.
• Assistant Examiner(s): Keehan, Christopher
• Application Number:
  US10/203,879
• Publication Number:
  US 20030054166A1
• Time in Patent Office: 782 Days
• Field of Search: 428/355.AC, 428/1.31, 524/190, 524/205, 524/208, 524/246, 524/293, 524/369, 524/481, 524/484, 524/485, 524/486, 524/81, 524/155, 524/167, 524/170, 524/172, 524/186, 524/189, 524/197, 524/210, 524/700, 524/707, 524/715, 524/722, 524/736, 524/741, 524/743, 353/20
• US Class Current: 428/355.0AC
• CPC Class Codes: C09J 133/062 Copolymers with monomers not covered by C09J133/06
• CPC Class Codes: C09J 2301/302 the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
• CPC Class Codes: C09K 2323/031 Polarizer or dye
• CPC Class Codes: Y10T 428/2891 including addition polymer from alpha-beta unsaturated carboxylic acid [e.g., acrylic acid, methacrylic acid, etc.] Or derivative thereof

Abstract

The present invention provides an acrylic pressure sensitive adhesive composition having an element with a positive stress optical coefficient for a polarizing film and a polarizing film using the same.

Claims

1. An acrylic pressure sensitive adhesive (PSA) composition for a polarizer comprising a component having a positive stress optical coefficient, wherein the component having a positive stress optical coefficient is an aromatic compound represented by formula 1:

wherein

X and Y, and R₁ and R₂ are substituted groups selected from C₁˜

C₂₀ alkyl, C₁˜

C₂₀ alkoxy, C₆˜

C₂₀ aryl, hydrogen, cyano, chloride, bromide, hydroxy, dimethyl amine, or cumyl;

A—

B is —

CH═

N—

, —

N═

N—

, —

N═

N(O)—

, —

COO—

, —

CH₂O—

, —

C(R₁)CO—

, —

COO—

CH₂—

, —

C═

C—

, —

C≡

C—

, —

S—

, —

SO₂—

, -Φ

(R₁)—

, —

CH═

N-Φ

(R₁)—

N═

CH—

, —

C═

C-Φ

(R₁)—

N═

C—

, —

C═

C-Φ

(R₁)—

C═

C—

, —

C═

C—

Φ

(R₁) -Φ

(R₂) —

C═

C—

, —

C═

N-Φ

(R₁) -Φ

(R₂)—

N═

C—

, —

C═

N-Φ

(R₁)-Φ

(R₂)—

C═

C—

that act as cores, or a core of naphthalene or anthracene, or A—

B can be eliminated for direct connection;

wherein when a is an integer of 1 to 3, b is an integer of 0 to 3; and

when a is 0, b is an integer of 1 to 3.

2. The acrylic PSA composition according to claim 1, wherein the composition comprises:

(a) 100 parts by weight of an acrylic copolymer forming a cross-linking structure; and

(b) 0.01 to 30 parts by weight of the component having a positive stress optical coefficient.

3. The acrylic PSA composition according to claim 1, wherein the component having a positive stress optical coefficient has an asymmetric molecular structure in the direction of a long axis.

4. The acrylic PSA composition according to claim 3, wherein the molecular weight of the component having a positive stress optical coefficient is equal to or less than 2,000.

5. The acrylic PSA composition according to claim 1, wherein the aromatic compound is selected from a group consisting of biphenyl, trans-stilbene, azobenzene, p-terphenyl, m-terphenyl, cumylphenylbenzoate, diphenylacetylene, 4-ethylbiphenyl, 4′

-pentyl-4-biphenyl carbonitrile, 4-biphenylcarbonitrile, 4′

-pentylbiphenyl, 4′

-pentoxy-4-biphenylcarbonitrile, 4′

-hexyl-4-biphenylcarbonitrile, 4′

-octyl-4-biphenyl carbonitrile, trans-4-octyl-4′

-ethoxystilbene, naphthalene, anthracene, 4′

-methoxybenzylideneaminostilbene, 4′

-methoxybenzylideneaminoazobenzene, and a mixture thereof.

6. The acrylic PSA composition according to claim 2, wherein the acrylic PSA composition further comprises c) 0.01 to 10 parts by weight of a multi-functional cross-linking compound based on 100 parts by weight of the acrylic copolymer.

7. The acrylic PSA composition according to claim 1, wherein the crosslinking density of the acrylic adhesive composition ranges from 1 to 95%.

8. A polarizer comprising a PSA layer that is formed on either surface of the polarizer, wherein the PSA layer comprises the acrylic PSA composition according to claim 1.

9. The polarizer according to claim 8, wherein the polarizer has a protection film with a positive stress optical coefficient.

10. The polarizer according to claim 9, wherein the polarizer protection film comprises triacetyl cellulose.

11. The polarizer according to claim 8, wherein the polarizer further comprises at least one selected from the group consisting of retardation films, films for wide viewing angle, and films for brightness enhancement.