Phase difference plate comprising polymer film containing compound having rod-shaped molecular structure

• US 20060144291A1
• Filed: 03/07/2006
• Published: 07/06/2006
• Est. Priority Date: 03/14/2001
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Takeuchi, Hiroshi, Fujii, Takamichi, Sata, Hiroaki, Kawanishi, Hiroyuki
• Granted Patent: US 7,559,986 B2
• Time in Patent Office: Days
• US Class Current: 106/170.480
• CPC Class Codes: C09K 2323/02 Alignment layer characterised by chemical composition
• CPC Class Codes: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: C09K 2323/035 Ester polymer, e.g. polycarbonate, polyacrylate or polyester
• 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 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n

Abstract

A phase difference plate which comprises one sheet of polymer film containing a compound having a rod-shaped molecular structure and exhibiting a maximum absorption wavelength (λmax) of less than 250 nm in an ultraviolet spectrum of its solution and which exhibits a retardation value as measured at a wavelength of 450 nm (Re450) of 60 to 135 nm and a retardation value as measured at a wavelength of 590 nm (Re590) of 100 to 170 nm, where the relationship: Re590-Re450>2 nm is satisfied. The phase difference plate functions as a λ/4 plate.

Claims

1. A cellulose ester film comprising a compound represented by the following formula (II):

Ar¹-L¹-X-L³-Ar²  

 

(II)

in which each of Ar¹ and Ar² is independently an aromatic group;

each of L² and L³ is independently a divalent linking group selected from the group consisting of an alkylene group, —

O—

, —

CO— and

combinations thereof; and

X is 1,4-cyclohexylene, vinylene or ethynylene.

2. The cellulose ester film as defined in claim 1, wherein the compound represented by the formula (II) behaves as a liquid crystal.

3. The cellulose ester film as defined in claim 1, wherein the compound represented by the formula (II) is a rod-shaped compound.

4. The cellulose ester film as defined in claim 1, wherein the cellulose ester film is made of cellulose acetate.

5. The cellulose ester film as defined in claim 4, wherein the cellulose acetate has an acetic acid content in the range of 45.0 to 62.5%.

6. The cellulose ester film as defined in claim 1, wherein the cellulose ester film is a film stretched by 3 to 100%.

7. The cellulose ester film as defined in claim 1, wherein a refractive index of nx along the slow axis in the film plane, a refractive index of ny in the direction perpendicular to the slow axis in the film plane and a refractive index of nz along the depth of the film satisfy a condition of 1≦

(nx−

nz)/(nx−

ny)≦

2.

8. The cellulose ester film as defined in claim 1, wherein the compound represented by the formula (II) has a linear molecular structure.

9. The cellulose ester film as defined in claim 1, wherein the cellulose ester film contains the compound represented by the formula (II) in an amount of 0.01 to 20 weight parts based on 100 weight parts of the cellulose ester film.