PRESSURE-SENSITIVE ADHESIVE LAYER ATTACHED POLARIZING FILM AND IMAGE DISPLAY

• US 20150293287A1
• Filed: 08/27/2013
• Published: 10/15/2015
• Est. Priority Date: 08/31/2012
• Status: Active Grant

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Yasui, Atsushi, Toyama, Yuusuke, Fujihara, Arata, Kimura, Tomoyuki
• Granted Patent: US 10,422,935 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C08K 5/0075 Antistatics
• CPC Class Codes: C08K 5/34 Heterocyclic compounds having nitrogen in the ring
• CPC Class Codes: C08K 5/43 Compounds containing sulfur bound to nitrogen
• CPC Class Codes: C09J 133/06 of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
• CPC Class Codes: C09J 133/14 of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen
• CPC Class Codes: C09J 2203/318 for the production of liquid crystal displays
• CPC Class Codes: C09J 2301/302 the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
• CPC Class Codes: C09J 2301/408 additives as essential feature of the adhesive layer
• CPC Class Codes: C09J 2433/00 Presence of (meth)acrylic polymer
• CPC Class Codes: C09J 7/385 Acrylic polymers
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid
• CPC Class Codes: G02F 1/133528 Polarisers

Abstract

A pressure-sensitive adhesive layer attached polarizing film of invention includes a polarizing film; and a pressure-sensitive adhesive layer provided on the polarizing film, wherein the polarizing film comprises a polarizer and a transparent protective film provided on only one side of the polarizer, the pressure-sensitive adhesive layer is provided on a side of the polarizer opposite to the side on which the transparent protective film is provided, and the pressure-sensitive adhesive layer is made from a pressure-sensitive adhesive composition including a (meth)acryl-based polymer (A), an onium-anion salt (B1), and an alkali metal salt (B2). The pressure-sensitive adhesive layer attached polarizing film has a pressure-sensitive adhesive layer possessing an antistatic function and satisfactory durability even after a humidity test under severe conditions and is less prone to degradation of optical properties even after a humidity test under severe conditions.

Claims

1. A pressure-sensitive adhesive layer attached polarizing film, comprising:

a polarizing film; and

a pressure-sensitive adhesive layer provided on the polarizing film, wherein

the polarizing film comprises a polarizer and a transparent protective film provided on only one side of the polarizer, the pressure-sensitive adhesive layer is provided on a side of the polarizer opposite to the side on which the transparent protective film is provided, and

the pressure-sensitive adhesive layer is made from a pressure-sensitive adhesive composition comprising a (meth)acryl-based polymer (A), an onium-anion salt (B1), and an alkali metal salt (B2).

2. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, wherein the onium-anion salt (B1) is an onium-fluorine-containing imide anion salt.

3. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, wherein the onium of the onium-anion salt (B1) is at least one selected from a nitrogen-containing onium, a sulfur-containing onium, and a phosphorus-containing onium.

4. The pressure-sensitive adhesive layer attached polarizing film according to claim 3, wherein the onium of the onium-anion salt (B1) is at least one selected from ammonium, pyrrolidinium, piperidinium, and sulfonium.

5. The pressure-sensitive adhesive layer attached polarizing film according to claim 4, wherein the onium of the onium-anion salt (B1) is pyrrolidinium.

6. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, wherein the onium of the onium-anion salt (B1) has no unsaturated bond.

7. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, wherein the onium of the onium-anion salt (B1) is an alkyl onium having an alkyl group of 1 to 4 carbon atoms.

8. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, which contains 0.1 to 10 parts by weight of the onium-anion salt (B1) based on 100 parts by weight of the (meth)acryl-based polymer (A).

9. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, wherein the alkali metal of the alkali metal salt (B2) is lithium.

10. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, which contains 0.01 to 5 parts by weight of the alkali metal salt (B2) based on 100 parts by weight of the (meth)acryl-based polymer (A).

11. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, wherein the polarizer has a thickness of 10 μ

m or less.

12. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, wherein the (meth)acryl-based polymer (A) comprises an alkyl (meth)acrylate monomer unit and a hydroxyl group-containing monomer unit.

13. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, wherein the (meth)acryl-based polymer (A) comprises an alkyl (meth)acrylate monomer unit and a carboxyl group-containing monomer unit.

14. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, wherein the pressure-sensitive adhesive composition further comprises a crosslinking agent (C).

15. The pressure-sensitive adhesive layer attached polarizing film according to claim 14, which contains 0.01 to 20 parts by weight of the crosslinking agent (C) based on 100 parts by weight of the (meth)acryl-based polymer (A).

16. The pressure-sensitive adhesive layer attached polarizing film according to claim 14, wherein the crosslinking agent (C) is at least one selected from an isocyanate compound and a peroxide.

17. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, further comprising 0.001 to 5 parts by weight of a silane coupling agent (D) based on 100 parts by weight of the (meth)acryl-based polymer (A).

18. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, further comprising 0.001 to 10 parts by weight of a polyether-modified silicone compound based on 100 parts by weight of the (meth)acryl-based polymer (A).

19. The pressure-sensitive adhesive layer attached polarizing film according to claim 1, wherein the (meth)acryl-based polymer (A) has a weight average molecular weight of 500,000 to 3,000,000.

20. An image display, comprising at least one piece of the pressure-sensitive adhesive layer attached polarizing film according to claim 1.