Optical film, circularly polarizing plate and organic electroluminescent display device

Patent metadata

Field	Value
Publication number	US-9720140-B2
Application number	US-201414785774-A
Country	US
Kind code	B2
Filing date	Apr 16, 2014
Priority date	Apr 23, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

Provided is an optical film containing a cellulose derivative, the optical film having an in-plane retardation Ro 550 within the range of 120 to 160 nm measured at a wavelength of 550 nm under an atmosphere of a temperature of 23° C. and a relative humidity of 55%, and a ratio Ro 450 /Ro 550 within the range of 0.65 to 0.99, Ro 450 /Ro 550 being a ratio of an in-plane retardation Ro 450 measured at a wavelength of 450 nm to the in-plane retardation Ro 550 measured at a wavelength of 550 nm, wherein, a substituent of a glucose skeleton in the cellulose derivative satisfies the requirements (a) and (b) which are described in the specification, and the optical film contains a compound A satisfying the following condition defined by Expression (a1) which is described in the specification.

First claim

The invention claimed is:

1. An optical film comprising a cellulose derivative having a glucose skeleton containing a substituent, the optical film having an in-plane retardation Ro 550 within a range of 120 to 160 nm measured at a wavelength of 550 nm under an atmosphere of a temperature of 23° C. and a relative humidity of 55%, and a ratio Ro 450 /Ro 550 within a range of 0.65 to 0.99, Ro 450 /Ro 550 being a ratio of an in-plane retardation Ro 450 measured at a wavelength of 450 nm to the in-plane retardation Ro 550 measured at a wavelength of 550 nm,
wherein, the substituent of the glucose skeleton in the cellulose derivative satisfies the following requirements (a) and (b), and
the optical film contains a compound A satisfying the following condition defined by an Expression (a1),
requirement (a): a part of the substituent contained in the glucose skeleton of the cellulose derivative is a substituent having a multiple bond, and an average degree of substitution of the substituent having a multiple bond is within a range of 0.1 to 3.0 per glucose skeleton unit,
requirement (b): a maximum absorption wavelength of the substituent having a multiple bond is within a range of 220 to 400 nm,
( Sw−S )≧0.30,  Expression (a1):

wherein S represents an orientation degree of the compound A in the optical film, and Sw represents an orientation degree of the compound A in the optical film in the presence of water.

2. The optical film described in claim 1 , wherein the compound A satisfies the following condition defined by an Expression (a2), and the compound A contains a plurality of ring structures including a heterocyclic ring in a long axis of the compound A,
0.50≦( na−nb )≦1.50,  Expression (a2):

wherein n a represents a refractive index in a long axis direction of the compound A, and n b represents a refractive index in an orthogonal direction to the long axis direction of the compound A.

3. The optical film described in claim 1 , wherein the compound A is a compound having a structure represented by the following Formula (1):
A 1 -L 1 -W 1 -L 2 -B L 3 -W 2 -L 4 n A 2   Formula (1)

wherein A 1 and A 2 each represent an alkyl group, a cycloalkyl group, an aromatic hydrocarbon ring or an aromatic heterocyclic ring, L 1 , L 2 , L 3 and L 4 each represent a single bond or a divalent linking group, W 1 and W 2 each represent an aromatic heterocyclic ring or an aliphatic heterocyclic ring, B represents an aromatic hydrocarbon ring, an aliphatic hydrocarbon ring, an aromatic heterocyclic ring or aliphatic heterocyclic ring, n represents an integer of 0 to 5, provided that when n is 2 or more, a plurality of L 3 , L 4 and W 2 are the same or different.

4. The optical film described in claim 1 , wherein the average degree of substitution of the substituent having a multiple bond is within the range of 0.2 to 3.0 per glucose skeleton unit.

5. The optical film described in claim 1 , wherein the average degree of substitution of the substituent having a multiple bond at positions 2, 3, and 6 of the glucose skeleton satisfies the following Expression (1),
0<(Average degree of substitution at position 2+Average degree of substitution at position 3)−Average degree of substitution at position 6.  Expression (1):

6. The optical film described in claim 1 , wherein the maximum absorption wavelength of the substituent having a multiple bond is within a range of 220 to 300 nm.

7. The optical film described in claim 1 , wherein the substituent having a multiple bond contains an aromatic ring.

8. The optical film described in claim 1 , wherein the optical film has a thickness within a range of 20 to 60 μm.

9. The optical film described in claim 1 , wherein the optical film is a long film having a slow axis in a direction of 40 to 50° with respect to a longitudinal direction of the optical film.

10. A circularly polarizing plate comprising the optical film described in claim 1 and a polarizer element bonded to the optical film.

11. An organic electroluminescent display device provided with the circularly polarizing plate described in claim 10 .

Assignees

• Konica Minolta Inc

Inventors

• Fujisawa Rie
• Kiuchi Hiroyoshi
• Fukusaka Kiyoshi
• Suzuki Takatugu
• Kita Hiroshi

Classifications

• H05B33/02

  Details · CPC title

• C07D213/69

  Two or more oxygen atoms · CPC title

• C07D249/08

  1,2,4-Triazoles; Hydrogenated 1,2,4-triazoles · CPC title

• G02B5/3083

  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 title

• C07C235/56

  having the nitrogen atom of at least one of the carboxamide groups bound to a carbon atom of a six-membered aromatic ring · CPC title