OPTICAL COMPENSATION FILM, POLARIZING PLATE AND LIQUID CRYSTAL DISPLAY

• US 20090079910A1
• Filed: 03/22/2006
• Published: 03/26/2009
• Est. Priority Date: 03/22/2005
• Status: Abandoned Application

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Nakamura, Ryo, Ito, Yoji
• Application Number:
  US11/815,768
• Publication Number:
  US 20090079910A1
• Time in Patent Office: Days
• US Class Current: 349/75
• CPC Class Codes: B32B 23/08 of synthetic resin
• CPC Class Codes: B32B 23/20 comprising esters
• CPC Class Codes: B32B 27/06 as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/28 comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42
• 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 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133633 using mesogenic materials
• CPC Class Codes: G02F 2202/40 Materials having a particular birefringence, retardation
• CPC Class Codes: G02F 2413/02 Number of plates being 2
• CPC Class Codes: G02F 2413/07 All plates on one side of the LC cell

Abstract

An optical compensation film is provided and has a cellulose acylate film coated with an optically anisotropic layer containing a liquid crystalline compound, cellulose having a glucose unit, a hydroxyl group of the glucose unit being substituted with an acyl group having at least two carbon atoms. The cellulose acylate film satisfies relationships specified in the specification.

Claims

1. An optical compensation film comprising:

a cellulose acylate film;

an optically anisotropic layer comprising a liquid crystalline compound,

wherein the cellulose acylate film comprises a cellulose having a glucose unit, a hydroxyl group of the glucose unit being substituted with an acyl group having at least two carbon atoms, and the cellulose acylate film satisfies relationships (I) and (II);

2.0≦

DS2+DS3+DS6≦

3.0 

 

(I)

DS6(DS2+DS3+DS6)≦

0.315 

 

(II)

wherein DS2 stands for a substitution degree of the hydroxyl group at 2-position of the glucose unit with the acyl group, DS3 stands for a substitution degree of the hydroxyl group at 3-position of the glucose unit with the acyl group, and DS6 stands for a substitution degree of the hydroxyl group at 6-position of the glucose unit with the acyl group.

2. The optical compensation film according to claim 1, wherein the cellulose acylate film contains a retardation developer comprising one of a rod-shaped compound and a discotic compound.

3. The optical compensation film according to claim 1, which has a difference between retardation values Re(550) under 25°

C.-10% RH and 25°

-80% RH conditions, Δ

Re (Re10% RH-Re80% RH), of 12 nm or below and has a difference between retardation values Rth(550) under 25°

C.-10% RH and 25°

-80% RH conditions, Δ

Rth (Rth10% RH-Rth80% RH), of 32 nm or below, wherein Re(λ

) is an in-plane retardation expressed in the units nm at a wavelength of λ

nm and Rth(λ

) is a thickness-direction retardation expressed in the units nm at a wavelength of λ

nm.

4. The optical compensation film according to claim 1, wherein the liquid crystalline compound is a discotic liquid crystalline compound.

5. The optical compensation film according to claim 1, wherein the liquid crystalline compound is a rod-shaped liquid crystalline compound.

6. The optical compensation film according to claim 5, wherein the cellulose acylate film has an Re(550) value of 20 nm to 150 nm and an Rth(550)/Re(550) ratio of 1.5 to 7, and the optically anisotropic layer has an Re(550) value of 0 nm to 10 nm and an Rth(550) value of −

80 nm to −

400 nm, wherein Re(λ

) is an in-plane retardation expressed in the units nm at a wavelength of λ

nm and Rth(λ

) is a thickness-direction retardation expressed in the units nm at a wavelength of λ

nm.

8. A polarizing plate comprising:

a polarizer; and

an optical compensation film according to claim 1.

9. A liquid crystal display comprising:

a liquid crystal cell; and

an optical compensation film according to claim 1.

10. The liquid crystal display according to claim 9, wherein the liquid crystal cell is of an IPS mode.

11. The liquid crystal display according to claim 9, wherein the liquid crystal cell is of an OCB mode.

7. An optical compensation film comprising:

a cellulose acylate film;

an optically anisotropic layer comprising a rod-shaped liquid crystalline compound,

wherein the cellulose acylate film comprises a cellulose having a glucose unit, a hydroxyl group of the glucose unit being substituted with an acyl group having at least two carbon atoms, and the cellulose acylate film satisfies relationships (I) and (II);

2.0≦

DS2+DS3+DS6≦

3.0 

 

(I)

DS6(DS2+DS3+DS6)≦

0.315 

 

(II)

wherein DS2 stands for a substitution degree of the hydroxyl group at 2-position of the glucose unit with the acyl group, DS3 stands for a substitution degree of the hydroxyl group at 3-position of the glucose unit with the acyl group, and DS6 stands for a substitution degree of the hydroxyl group at 6-position of the glucose unit with the acyl group.