Optical film, polarizing plate, and image display device

Patent metadata

Field	Value
Publication number	US-2018201701-A1
Application number	US-201815922212-A
Country	US
Kind code	A1
Filing date	Mar 15, 2018
Priority date	Sep 30, 2015
Publication date	Jul 19, 2018
Grant date	—

Abstract

An object of the present invention is to provide an optical film having an optically anisotropic layer having excellent durability, and a polarizing plate and an image display device using the same. This optical film of the present invention is an optical film at least having an optically anisotropic layer, in which the optically anisotropic layer is a layer obtained by polymerizing a polymerizable liquid crystal composition containing a predetermined liquid crystal compound and a polymerization initiator, and the optically anisotropic layer has a density of 1.20 g/cm 3 or more and a crosslinking point density of 0.0016 mol/cm 3 or more.

First claim

What is claimed is:

1 . An optical film comprising, at least:
an optically anisotropic layer, wherein the optically anisotropic layer is a layer obtained by polymerizing a polymerizable liquid crystal composition containing a liquid crystal compound represented by Formula (1) and a polymerization initiator, and the optically anisotropic layer has a density of 1.20 g/cm 3 or more and a crosslinking point density of 0.0016 mol/cm 3 or more,

in Formula (1),
Ar 1 represents an n-valent aromatic group,
L 1 represents a single bond, —COO—, or —OCO—,
A represents an aromatic ring having 6 or more carbon atoms or a cycloalkylene ring having 6 or more carbon atoms,
Sp represents a single bond, a linear or branched alkylene group having 1 to 12 carbon atoms, or a divalent linking group in which one or more —CH 2 — groups that constitute a linear or branched alkylene group having 1 to 12 carbon atoms are substituted with —O—, 13 S—, —NH—, —N(Q)-, or —CO—,
Q represents a polymerizable group,
m represents an integer of 0 to 2, and
n represents an integer of 1 or 2,
where all of L, A, Sp, and Q, a plurality of which are provided depending on the number of m or n, may be the same or different from each other.

2 . The optical film according to claim 1 ,
wherein the optically anisotropic layer has a density of 1.25 g/cm 3 or more.

3 . The optical film according to claim 1 ,
wherein the optically anisotropic layer satisfies Expression (I),
0.75 ≤Re (450)/ Re (550) 1.00   (I)

in Expression (I), Re(450) represents an in-plane retardation of the optically anisotropic layer at a wavelength of 450 nm, and Re(550) represents an in-plane retardation of the optically anisotropic layer at a wavelength of 550 nm.

4 . The optical film according to claim 2 ,
wherein the optically anisotropic layer satisfies Expression (I),
0.75 ≤Re (450)/ Re (550)≤1.00   (I)

in Expression (I), Re(450) represents an in-plane retardation of the optically anisotropic layer at a wavelength of 450 nm, and Re(550) represents an in-plane retardation of the optically anisotropic layer at a wavelength of 550 nm.

5 . The optical film according to claim 1 ,
wherein the polymerizable liquid crystal composition contains a polymerizable compound other than the liquid crystal compound represented by Formula (1).

6 . The optical film according to claim 2 ,
wherein the polymerizable liquid crystal composition contains a polymerizable compound other than the liquid crystal compound represented by Formula (1).

7 . The optical film according to claim 3 ,
wherein the polymerizable liquid crystal composition contains a polyrnerizable compound other than the liquid crystal compound represented by Formula (1).

8 . The optical film according to claim 5 ,
wherein the polymerizable compound is a compound having a mesogen group.

9 . The optical film according to claim 8 ,
wherein the compound having a mesogen group has at least one ring structure selected from the group consisting of a benzene ring and a cyclohexane ring.

10 . The optical film according to claim 8 ,
wherein the number of cyclohexane rings in the compound having a mesogen group is 2 or less.

11 . The optical film according to claim 9 ,
wherein the number of cyclohexane rings in the compound having a mesogen group is 2 or less,

12 . The optical film according to claim 9 ,
wherein the ring structure has a substituent having a van der Waals volume of 0.30 Å 3 or less.

13 . The optical film according to claim 10 ,
wherein the ring structure has a substituent having a van der aa s volume of 0.30 Å 3 or less.

14 . The optical film according to claim 1 ,
wherein the polymerization initiator is an oxime type polymerization initiator.

15 . The optical film according to claim 2 ,
wherein the polymerization initiator is an oxime type polymerization initiator.

16 . The optical film according to claim 3 ,
wherein the polymerization initiator is an oxime type polymerization initiator.

17 . The optical film according to claim 5 ,
wherein the polymerization initiator is an oxime type polymerization initiator.

18 . The optical film according to claim 8 ,
wherein the polymerization initiator is an oxime type polymerization initiator.

19 . A polarizing plate comprising:
the optical film according to claim 1 ; and a polarizer.

20 . An image display device comprising:
the optical film according to claim 1 ; or the polarizing plate according to claim 19 .

Assignees

• Fujifilm Corp

Inventors

• Muramatsu Ayako
• Sato Hiroshi
• Saito Kengo
• Komiyama Takashi
• Takahashi Keita

Classifications

• G02F1/133528

  Polarisers · CPC title

• C08F20/30 Primary

  containing aromatic rings in the alcohol moiety · CPC title

• C09K19/3804 Primary

  with mesogenic groups in the main chain · CPC title

• G02B5/3025

  Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state (G02B5/3008, G02B5/3016 take precedence) · CPC title

• G02B5/3091

  for use in the UV · CPC title