Deflecting plate and liquid crystal display device

• US 8,537,309 B2
• Filed: 11/08/2005
• Issued: 09/17/2013
• Est. Priority Date: 11/09/2004
• Status: Active Grant

• Current Assignee: ZEON Corporation
• Original Assignee: ZEON Corporation
• Inventors: Toyoshima, Tetsuya, Arakawa, Kouhei
• Primary Examiner(s): Robinson, Mark
• Assistant Examiner(s): Chiem, Erin
• Application Number:
  US11/667,275
• Publication Number:
  US 20070285777A1
• Time in Patent Office: 2,870 Days
• Field of Search: 349/96
• US Class Current: 349/96
• CPC Class Codes: B32B 2457/20 Displays, e.g. liquid crystal displays, plasma displays
• CPC Class Codes: G02B 1/105 Protective coatings
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02F 1/133502 Antiglare, refractive index matching layers
• CPC Class Codes: G02F 1/133528 Polarisers

Abstract

The present invention provides a polarizer plate including at least a protective layer A, a polarizer, and a protective layer B in that order, the protective layer A including at least layers a and b respectively including a thermoplastic resin as a main component, the layer a having a flexural modulus higher than that of the layer b; and a liquid crystal display device including a light source, an incident-side polarizer plate, a liquid crystal cell, and an exit-side polarizer plate in that order, the incident-side polarizer plate and/or the exit-side polarizer plate being the polarizer plate of the present invention. According to the present invention, a polarizer plate exhibiting high tenacity and high surface hardness and a liquid crystal display device including the polarizer plate are provided.

Claims

1. A polarizer plate comprising at least a protective layer A, a polarizer formed of polyvinyl alcohol, and a protective layer B in that order,

the protective layer A being obtained by coextrusion and including at least layers a and b respectively including a thermoplastic resin as a main component,

the layer a having a flexural modulus of 3 GPa to 4 GPa and the layer b being formed of at least one kind of resin selected from the group consisting of an alicyclic structure-containing polymer, a cellulose polymer, a polyester polymer, a polycarbonate polymer, a polysulfone polymer, a polyethersulfone polymer, a vinyl aromatic polymer, a polyolefin polymer, a polyvinyl alcohol polymer, a polyvinyl chloride polymer, and a poly(meth)acrylate polymer and having a flexural modulus of 2.1 GPa to 3.0 GPa and a thickness of 5 to 52 μ

m,

wherein the flexural modulus of layer a is higher than the flexural modulus of layer b, and

wherein a difference in flexural modulus between the layers a and b is 0.2 GPa to 1.2 GPa.

2. The polarizer plate according to claim 1, wherein the protective layer A has a water vapor transmission rate of 10 g/day·

m² or less.

3. The polarizer plate according to claim 1, wherein the protective layer B is a layer exhibiting birefringence.

4. A liquid crystal display device comprising a light source, an incident-side polarizer plate, a liquid crystal cell, and an exit-side polarizer plate in that order, wherein the incident-side polarizer plate and/or the exit-side polarizer plate is the polarizer plate according to claim 1.

5. A liquid crystal display device comprising a light source, an incident-side polarizer plate, a liquid crystal cell, and an exit-side polarizer plate in that order, wherein the exit-side polarizer plate is the polarizer plate according to claim 1.

6. A liquid crystal display device comprising a light source, an incident-side polarizer plate, a liquid crystal cell, and an exit-side polarizer plate in that order, wherein the incident-side polarizer plate and/or the exit-side polarizer plate is the polarizer plate according to claim 1, and wherein the polarizer plate according to claim 1 is disposed so that the layer b is located closer to the liquid crystal cell than is the layer a.

7. The polarizer plate according to claim 1, wherein the protective layer A includes the layer a, the layer b, and a layer c.

8. The polarizer plate according to claim 7, wherein the layer b and the layer c are formed of a poly(meth)acrylate polymer.

9. The polarizer plate according to claim 1, wherein the layer b is provided adjacent to the polarizer.

10. The polarizer plate according to claim 1, wherein the thermoplastic resin is at least one thermoplastic resin selected from the group consisting of a vinyl aromatic polymer, a poly(meth)acrylate polymer, a polyacrylonitrile polymer, a vinyl alicyclic hydrocarbon polymer, and a hydrogenated product thereof.

11. The polarizer plate according to claim 1, where the layer b is formed by at least one thermoplastic resin selected from the group consisting of an alicyclic structure-containing polymer, a cellulose polymer, and a polyester polymer.

12. The polarizer plate according to claim 1, where the layer b is formed by at least one thermoplastic resin selected from the group consisting of an alicyclic structure-containing polymer, a cellulose polymer and a polycarbonate polymer.

13. The polarizer plate according to claim 1, where the protective layer A has a three-layer structure formed of the layers a, x, and b or a five-layer structure formed of the layers a, x, b, x, and a, wherein the layer x is an adhesive layer.