U.S. patent application number 14/911097 was filed with the patent office on 2016-07-14 for photo-alignment material and photo-alignment method.
This patent application is currently assigned to TOKYO INSTITUTE OF TECHNOLOGY. The applicant listed for this patent is DIC CORPORATION, TOKYO INSTITUTE OF TECHNOLOGY. Invention is credited to Motoi Kinoshita, Isa Nishiyama, Atsushi Shishido.
Application Number | 20160202560 14/911097 |
Document ID | / |
Family ID | 52468281 |
Filed Date | 2016-07-14 |
United States Patent
Application |
20160202560 |
Kind Code |
A1 |
Kinoshita; Motoi ; et
al. |
July 14, 2016 |
PHOTO-ALIGNMENT MATERIAL AND PHOTO-ALIGNMENT METHOD
Abstract
A photo-alignment material in which an alignment film can be
formed parallel to a vibration direction of light and a tilt angle
of the alignment film is easily controlled and a photo-alignment
method using the photo-alignment material are provided. A
photo-alignment material of the present invention contains a
photo-responsive substance having a threshold value of responding
light intensity.
Inventors: |
Kinoshita; Motoi; (Tokyo,
JP) ; Shishido; Atsushi; (Tokyo, JP) ;
Nishiyama; Isa; (Kitaadachi-gun, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOKYO INSTITUTE OF TECHNOLOGY
DIC CORPORATION |
Tokyo
Tokyo |
|
JP
JP |
|
|
Assignee: |
TOKYO INSTITUTE OF
TECHNOLOGY
Tokyo
JP
DIC CORPORATION
Tokyo
JP
|
Family ID: |
52468281 |
Appl. No.: |
14/911097 |
Filed: |
August 6, 2014 |
PCT Filed: |
August 6, 2014 |
PCT NO: |
PCT/JP2014/070747 |
371 Date: |
February 9, 2016 |
Current U.S.
Class: |
427/457 |
Current CPC
Class: |
C09K 19/56 20130101;
G02F 1/133788 20130101; C09K 2323/00 20200801; C09K 2323/02
20200801; C08L 101/00 20130101; C08F 2/48 20130101; G03H 1/02
20130101; G02F 1/133711 20130101; G03H 2001/026 20130101 |
International
Class: |
G02F 1/1337 20060101
G02F001/1337; C09K 19/56 20060101 C09K019/56 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 14, 2013 |
JP |
2013-168669 |
Claims
1-27. (canceled)
28. A photo-alignment material, comprising: a photo-responsive
substance having a threshold value of responding light
intensity.
29. The photo-alignment material according to claim 28, further
comprising: an oligomer and/or a polymer.
30. The photo-alignment material according to claim 28, further
comprising: an anisotropic substance.
31. The photo-alignment material according to claim 28, wherein the
photo-responsive substance is an anisotropic substance which does
not cause a photochemical reaction, and a long axis direction of
the photo-responsive substance is aligned parallel to a vibration
direction of light by irradiating the light having light intensity
of greater than or equal to the threshold value.
32. The photo-alignment material according to claim 28, wherein the
threshold value of the light intensity is less than or equal to 10
W/cm.sup.2.
33. A photo-alignment method, comprising: irradiating the
photo-alignment material according to claim 28 with light having
light intensity of greater than or equal to the threshold
value.
34. The photo-alignment method according to claim 33, wherein the
light to be irradiated to the photo-alignment material is
irradiated at an angle with respect to a normal direction of a
layer comprising the photo-alignment material.
35. The photo-alignment method according to claim 34, wherein the
angle is less than or equal to 10 degrees with respect to the
normal direction of the layer comprising the photo-alignment
material.
36. An optical anisotropic material, comprising: the
photo-alignment material according to claim 28 wherein at least a
part of the photo-alignment material has alignment-control ability
by irradiating at least the part with light having light intensity
of greater than or equal to the threshold value.
37. An optical element formed of a lens, a retardation film, or a
hologram, comprising: the photo-alignment material according to
claim 28 wherein at least a part of the photo-alignment material
has alignment-control ability by irradiating at least the part with
light having light intensity of greater than or equal to the
threshold value.
38. An alignment film, comprising: the photo-alignment material
according to claim 28 wherein at least a part of the
photo-alignment material has alignment-control ability by
irradiating at least the part with light having light intensity of
greater than or equal to the threshold value.
39. A display element formed of a liquid crystal display element or
electronic paper, comprising: the photo-alignment material
according to claim 28 wherein at least a part of the
photo-alignment material has alignment-control ability by
irradiating at least the part with light having light intensity of
greater than or equal to the threshold value.
40. An optical anisotropic body, comprising: p1 the photo-alignment
material according to claim 28 wherein at least a part of the
photo-alignment material has alignment-control ability by
irradiating at least the part with light having light intensity of
greater than or equal to the threshold value.
41. A manufacturing method of an alignment film, comprising steps
of: forming a film of the photo-alignment material according to
claim 28 on a substrate; and photo-aligning at least a part of the
photo-alignment material by irradiating at least the part of the
film of the photo-alignment material with light having light
intensity of greater than or equal to the threshold value.
42. The manufacturing method of an alignment film according to
claim 41, wherein a long axis direction of the photo-responsive
substance is aligned parallel to a vibration direction of light by
irradiating the light such that the light intensity is greater than
or equal to the threshold value.
43. The manufacturing method of an alignment film according to
claim 41, wherein the light to be irradiated to the photo-alignment
material is irradiated at an angle with respect to a normal
direction of a layer comprising the photo-alignment material.
44. The manufacturing method of an alignment film according to
claim 43, wherein the angle is less than or equal to 10 degrees
with respect to the normal direction of the layer comprising the
photo-alignment material.
45. A manufacturing method of a liquid crystal display element,
comprising steps of: manufacturing an alignment film by the
manufacturing method of an alignment film according to claim 41;
preparing a substrate cell by bonding two substrates such that a
surface on which the alignment film is provided is positioned on an
inner side and an interval between the substrates has a
predetermined value; preparing a liquid crystal cell by filling the
cell with a liquid crystal composition; and interposing the liquid
crystal cell between polarizing plates.
46. A manufacturing method of an optical anisotropic body,
comprising steps of: manufacturing an alignment film by the
manufacturing method of an alignment film according to claim 41;
applying a polymerizable liquid crystal composition onto a surface
of the substrate on which the alignment film is provided; and
polymerizing the polymerizable liquid crystal composition.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a photo-alignment material
and a photo-alignment method using the photo-alignment
material.
[0003] 2. Description of Related Art
[0004] A liquid crystal is a high-functional material having
fluidity and high refractive index anisotropy, and has
self-organizability and a cooperative effect which are not seen in
other materials. Further, in the liquid crystal, it is possible to
freely control molecular arrangement by a substrate surface
treatment or an external field. For example, an alignment film
represented by polyimide or a silane coupling agent is formed on
the surface of the substrate, and thus, liquid crystal molecules
can be arranged parallel to or perpendicular to the substrate. In
addition, when an electric field is used as the external field, an
alignment change is performed by applying a voltage such that the
liquid crystal molecules which have been arranged parallel to the
substrate are arranged perpendicular to the substrate. Therefore,
dynamic alignment control of the liquid crystal molecules can be
performed. A method of controlling the alignment has been widely
used as an operating principle of current liquid crystal
displays.
[0005] In order to use the liquid crystal in a liquid crystal
display, a liquid crystal memory element, or the like, a technology
of controlling the alignment of the liquid crystal is important.
Currently, initial alignment of the liquid crystal is controlled by
the alignment film represented by rubbing polyimide. Then,
alignment driving of the liquid crystal is controlled by the
electric field.
[0006] In the related art, a method has been used in which an
alignment film is formed by a photochemical process of irradiating
a film formed by using an azo compound with light and of allowing
the film to exhibit liquid crystal alignment properties.
[0007] On the other hand, a photophysical control method (the
Janossy effect, hereinafter, referred to as a "photophysical
process") based on a mutual interaction between excitation
polarization of a dye such as anthraquinone and a photoelectric
field is known as a technology of controlling the alignment by
using light (for example, refer to NPL 1).
[0008] The photochemical process and the photophysical process are
significantly different from each other in that the photochemical
process is a method using a linear optical effect in which a
response is indicated even with respect to extremely weak light,
whereas the photophysical process is a method using a non-linear
optical effect.
[0009] [NPL 1] Janossy I. et al. Mol. Cryst. Liq. Cryst., 1990,
179, 1.
SUMMARY OF THE INVENTION
[0010] When the alignment film is formed by using the photochemical
process, the alignment film is aligned perpendicular to a vibration
direction of light, and thus, an alignment film having a desired
tilt angle cannot be obtained.
[0011] The present invention has been made in consideration of the
circumstances described above, and an object of the present
invention is to provide a photo-alignment material in which an
alignment film or an optical anisotropic body can be formed by a
photophysical process, and a tilt angle of the alignment film or
the optical anisotropic body is easily controlled, and a
photo-alignment method using the photo-alignment material.
[0012] The present inventors have found that an alignment film or
an optical anisotropic body is formed by using a photo-alignment
material containing a photo-responsive substance having a threshold
value of responding light intensity, and thus, the alignment film
or the optical anisotropic body can be formed by a photophysical
process, and a tilt angle of the alignment film can be controlled,
and have completed the present invention.
[0013] That is, the present invention provides a photo-alignment
material containing a photo-responsive substance having a threshold
value of responding light intensity.
[0014] In addition, the present invention provides a
photo-alignment method of irradiating a photo-alignment material
containing a photo-responsive substance having a threshold value of
responding light intensity with light having a light intensity of
greater than or equal to the threshold value.
[0015] According to the present invention, an alignment film or an
optical anisotropic body can be formed by using a photophysical
process, and a tilt angle of the alignment film can be
controlled.
DESCRIPTION OF EMBODIMENTS
[0016] Embodiments of a photo-alignment material and a
photo-alignment method of the present invention will be
described.
[0017] Furthermore, this embodiment will be specifically described
in order to allow the gist of the present invention to be easily
understood, but the present invention is not limited to this
embodiment, unless otherwise particularly stated.
[0018] [Photo-Alignment Material]
[0019] A photo-alignment material of the present invention contains
a photo-responsive substance having a threshold value of responding
light intensity.
[0020] A compound having a threshold value of responding light
intensity is used as the photo-responsive substance. Specifically,
the photo-responsive substance is not particularly limited insofar
as the photo-responsive substance has a molecular structure having
anisotropy in absorption with respect to light. As a
photo-responsive substance, in which even when a photochemical
reaction is caused or is not caused, it is preferable that the
influence of the reaction with respect to alignment of an
anisotropic substance be small, and for example, a compound is used
in which even when light in a visible light region or a region
other than the visible light region is irradiated, a threshold
value is obtained in responding light intensity by absorbing the
light.
[0021] In the present invention, the means that the
photo-responsive substance responds when irradiated with the light
indicates that the photo-responsive substance is aligned at the
time of being irradiated with the light. More specifically, the
photo-responsive substance being aligned indicates that a long axis
direction of the photo-responsive substance is aligned parallel to
a vibration direction of the light (an electric field vector of
polarized light).
[0022] In order to further decrease light intensity (light energy)
to be irradiated, it is preferable that a threshold value (the
minimum value) of necessary light intensity further decrease, and
for example, the threshold value be preferably less than or equal
to 10 W/cm.sup.2, more preferably less than or equal to 5
W/cm.sup.2, and even more preferably less than or equal to 1
W/cm.sup.2. In addition, in order to control the photo-responsive
substance such that the photo-responsive substance is aligned in
specific light intensity, it is preferable that the threshold value
of the necessary light intensity be adjusted to be in a specific
range. Furthermore, the threshold value of the necessary light
intensity indicates the minimum value of light intensity which is
necessary for the alignment of the photo-responsive substance.
[0023] A dichromatic dye is used as such a photo-responsive
substance, for example, as a photo-responsive substance responding
to light in a visible light region. The dichromatic dye is not
particularly limited, and examples of the dichromatic dye include
an anthraquinone-based dye, a merocyanine-based dye, a styryl-based
dye, an azomethine-based dye, a quinone-based dye, a
quinophthalone-based dye, a perylene-based dye, an indigo-based
dye, a tetrazine-based dye, a stilbene-based dye, a benzidine-based
dye, and the like. In addition, oligothiophene is also preferably
used.
[0024] Examples of the photo-responsive substance include an
oligothiophene-based compound denoted by General Formula (I-1)
shown below.
##STR00001##
[0025] (In the formula, R.sup.1 and R.sup.2 each independently
represent a hydrogen atom, an alkyl group having 1 to 14 carbon
atoms, an alkenyl group having 2 to 14 carbon atoms, an alkynyl
group having 2 to 14 carbon atoms, an alkoxy group having 1 to 14
carbon atoms, a cyano group (--CN), and a nitro group (--NO.sub.2),
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CO--, --OCO--, or --COO-- in the manner that oxygen
atoms are not directly adjacent to each other, one or more hydrogen
atoms of the alkyl group, the alkenyl group, the alkynyl group, and
the alkoxy group may be arbitrarily substituted with a halogen
atom, and n represents 1 to 8.)
[0026] R.sup.1 and R.sup.2 each independently preferably represent
an alkyl group having 1 to 10 carbon atoms (--C.sub.nH.sub.2n+1),
--OC.sub.nH.sub.2n+1, --N(C.sub.nH.sub.2n+1).sub.2,
--COOC.sub.nH.sub.2n+1, a cyano group (--CN), and a nitro group
(--NO.sub.2), and more preferably represent an alkyl group having 2
to 5 carbon atoms (--C.sub.nH.sub.2n+1), --OC.sub.nH.sub.2n+1,
--N(C.sub.nH.sub.2n+1).sub.2, --COOC.sub.nH.sub.2n+1.
[0027] n is preferably 1 to 5, and more preferably 1 to 3.
[0028] It is preferable that General Formula (I-1) described above
be a compound denoted by General Formula (I-2) shown below.
##STR00002##
[0029] (In the formula, R.sup.1 and R.sup.2 are identical to
R.sup.1 and R.sup.2 of General Formula (I-1) described above.)
[0030] Specifically, examples of the compound denoted by General
Formula (I-2) described above include a compound denoted by shown
below General Formula (I-3) as a compound having symmetry,
##STR00003##
[0031] a compound denoted by General Formula (I-4) shown below,
or
##STR00004##
[0032] a compound of which R.sup.1 and R.sup.2 each represent
--C.sub.4H.sub.9, --OC.sub.4H.sub.9, --N(C.sub.4H.sub.9).sub.2,
--COOC.sub.4H.sub.9, and --CN.
[0033] In addition, Examples of the compound denoted by above
General Formula (I-2) described above include a compound of which
R.sup.1 represents --C.sub.4H.sub.9 or --N(C.sub.4H.sub.9).sub.2,
and R.sup.2 represents --CN or --NO.sub.2 as a compound having
asymmetry.
[0034] In addition, examples of the compound denoted by General
Formula (I-1) described above include a compound denoted by General
Formula (I-5) shown below, and
##STR00005##
[0035] an uncolored compound denoted by General Formula (I-6) shown
below.
##STR00006##
[0036] In addition, examples of the oligothiophene-based compound
include a compound denoted by General Formula (I-7) shown
below.
##STR00007##
[0037] (In the formula, R.sup.1 and R.sup.2 are identical to
R.sup.1 and R.sup.2 of General Formula (I-1) described above, and n
represents 0 or 1.)
[0038] Examples of the compound denoted by General Formula (I-7)
described above include a compound denoted by General Formula (I-8)
shown below.
##STR00008##
[0039] (In the formula, n represents 0 or 1.)
[0040] In addition, examples of the photo-responsive substance
include a compound denoted by General Formula (I-9) shown
below.
##STR00009##
[0041] (In the formula, R.sup.1 and R.sup.2 are identical to
R.sup.1 and R.sup.2 of General Formula (I-1) described above.)
[0042] Examples of the compound denoted by General Formula (I-9)
described above include a compound denoted by General Formula
(I-10) shown below.
##STR00010##
[0043] In addition, examples of the photo-responsive substance
include a compound denoted by General Formula (I-11) shown
below.
##STR00011##
[0044] (In the formula, A.sup.1 and A.sup.2 each independently
represent a 1,4-phenylene group, a 2,5-thiophene group, and a
naphthalene-2,6-diyl group; R' and R'' each independently represent
a --CH.dbd.CH-- group and a --C.ident.C-- group; R.sup.1 and
R.sup.2 are identical to R.sup.1 and R.sup.2 of General Formula
(I-1) described above; n.sub.1 and n.sub.2 each independently
represent 0 to 8; and n.sub.3 and n.sub.4 each independently
represent 0 or 1.)
[0045] n.sub.1 and n.sub.2 are preferably 0 to 6, and are more
preferably 0 to 4.
[0046] Specifically, examples of the compound denoted by General
Formula (I-11) described above include compounds denoted by General
Formula (I-12) to General
[0047] Formula (I-19) shown below.
##STR00012##
[0048] (In the formula, R.sup.1 and R.sup.2 are identical to
R.sup.1 and R.sup.2 of General Formula (I-1) described above.)
##STR00013##
[0049] (In the formula, R.sup.1 and R.sup.2 are identical to
R.sup.1 and R.sup.2 of General Formula (I-1) described above.)
##STR00014##
[0050] (In the formula, R.sup.1 and R.sup.2 are identical to
R.sup.1 and R.sup.2 of General Formula (I-1) described above.)
##STR00015##
[0051] (In the formula, R.sup.1 and R.sup.2 are identical to
R.sup.1 and R.sup.2 of General Formula (I-1) described above.)
##STR00016##
[0052] (In the formula, R.sup.1 and R.sup.2 are identical to
R.sup.1 and R.sup.2 of General Formula (I-1) described above.)
##STR00017##
[0053] (In the formula, R.sup.1 and R.sup.2 are identical to
R.sup.1 and R.sup.2 of General Formula (I-1) described above.)
##STR00018##
[0054] (In the formula, R.sup.1 and R.sup.2 are identical to
R.sup.1 and R.sup.2 of General Formula (I-1) described above.)
##STR00019##
[0055] (In the formula, R.sup.1 and R.sup.2 are identical to
R.sup.1 and R.sup.2 of General Formula (I-1) described above.)
[0056] In addition, examples of the photo-responsive substance
include a coumarin-based compound denoted by General Formula (I-20)
shown below.
##STR00020##
[0057] (In the formula, R.sup.3 and R.sup.4 each independently
represent a hydrogen atom, an alkyl group having 1 to 14 carbon
atoms, an alkenyl group having 2 to 14 carbon atoms, an alkynyl
group having 2 to 14 carbon atoms, an alkoxy group having 1 to 14
carbon atoms, a cyano group (--CN), and a nitro group (--NO.sub.2),
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CO--, --OCO--, or --COO-- in the manner that oxygen
atoms are not directly adjacent to each other, and one or more
hydrogen atoms of the alkyl group, the alkenyl group, the alkynyl
group, and the alkoxy group may be arbitrarily substituted with a
halogen atom; and
[0058] B.sup.1 and B.sup.2 each independently represent a hydrogen
atom, an alkyl group having 1 to 14 carbon atoms, an alkenyl group
having 2 to 14 carbon atoms, an alkynyl group having 2 to 14 carbon
atoms, an alkoxy group having 1 to 14 carbon atoms, a cyano group
(--CN), a nitro group (--NO.sub.2), a phenyl group which may have a
substituent group (one or more --C.dbd. existing in the group may
be substituted with --N.dbd.), a naphthyl group which may have a
substituent group, a cyclohexyl group which may have a substituent
group (one or more --C-- existing in the group may be substituted
with --O-- or --S--), and any one group of General Formula (a),
(b), or (c) shown below, one or more CH.sub.2 groups of the alkyl
group may be substituted with --O--, --CO--, --OCO--, or --COO-- in
the manner that oxygen atoms are not directly adjacent to each
other, and one or more hydrogen atoms of the alkyl group, the
alkenyl group, the alkynyl group, and the alkoxy group may be
arbitrarily substituted with a halogen atom.)
##STR00021##
[0059] (In the formula, R.sup.5 represents a hydrogen atom, an
alkyl group having 1 to 14 carbon atoms, an alkenyl group having 2
to 14 carbon atoms, an alkynyl group having 2 to 14 carbon atoms,
an alkoxy group having 1 to 14 carbon atoms, a cyano group (--CN),
and a nitro group (--NO.sub.2), one or more CH.sub.2 groups of the
alkyl group may be substituted with --O--, --CO--, --OCO--, or
--COO-- in the manner that oxygen atoms are not directly adjacent
to each other, one or more hydrogen atoms of the alkyl group, the
alkenyl group, the alkynyl group, and the alkoxy group may be
arbitrarily substituted with a halogen atom.)
[0060] When R.sup.3 and R.sup.4 represent an alkyl group, an alkyl
group having 1 to 10 carbon atoms is preferable, and an alkyl group
having 1 to 5 carbon atoms is more preferable, and when B.sup.1 and
B.sup.2 represent an alkyl group, an alkyl group having 1 to 10
carbon atoms is preferable, and an alkyl group having 1 to 5 carbon
atoms is more preferable.
[0061] Examples of the compound denoted by General Formula (I-20)
described above include compounds denoted by General Formula (I-22)
to General Formula (I-24) shown below.
##STR00022##
[0062] (In the formula, R.sup.3 and R.sup.4 are identical to
R.sup.3 and R.sup.4 of General Formula (I-20) described above.)
##STR00023##
[0063] (In the formula, R.sup.3 and R.sup.4 are identical to
R.sup.3 and R.sup.4 of General Formula (I-20) described above.)
##STR00024##
[0064] (In the formula, R.sup.3 and R.sup.4 are identical to
R.sup.3 and R.sup.4 of General Formula (I-20) described above.)
[0065] In addition, examples of the coumarin-based compound include
a compound denoted by General Formula (I-25) shown below.
##STR00025##
[0066] (In the formula, B.sup.1 and B.sup.2 are identical to
B.sup.1 and B.sup.2 of General Formula (I-20) described above.)
[0067] When B.sup.1 and B.sup.2 represent an alkyl group, an alkyl
group having 1 to 10 carbon atoms is preferable, and an alkyl group
having 1 to 5 carbon atoms is more preferable.
[0068] Examples of the compound denoted by General Formula (I-25)
described above include compounds denoted by General Formula (I-26)
to General Formula (I-30) shown below.
##STR00026##
[0069] In addition, examples of the photo-responsive substance
include a compound denoted by General Formula (I-31) shown
below.
##STR00027##
[0070] (In the formula, R.sup.6 and R.sup.7 each independently
represent a hydrogen atom, an alkyl group having 1 to 14 carbon
atoms, an alkenyl group having 2 to 14 carbon atoms, an alkynyl
group having 2 to 14 carbon atoms, an alkoxy group having 1 to 14
carbon atoms, a cyano group (--CN), and a nitro group (--NO.sub.2),
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CO--, --OCO--, or --COO-- in the manner that oxygen
atoms are not directly adjacent to each other, and one or more
hydrogen atoms of the alkyl group, the alkenyl group, the alkynyl
group, and the alkoxy group may be arbitrarily substituted with a
halogen atom, and
[0071] B.sup.3 represents a hydrogen atom, an alkyl group having 1
to 14 carbon atoms, an alkenyl group having 2 to 14 carbon atoms,
an alkynyl group having 2 to 14 carbon atoms, an alkoxy group
having 1 to 14 carbon atoms, a cyano group (--CN), a nitro group
(--NO.sub.2), a phenyl group which may have a substituent group
(one or more --C.dbd. existing in the group may be substituted with
--N.dbd.), a naphthyl group which may have a substituent group, a
cyclohexyl group which may have a substituent group (one or more
--C-- existing in the group may be substituted with --O-- or
--S--), one or more CH.sub.2 groups of the alkyl group may be
substituted with --O--, --CO--, --OCO--, or --COO-- in the manner
that oxygen atoms are not directly adjacent to each other, and one
or more hydrogen atoms of the alkyl group, the alkenyl group, the
alkynyl group, and the alkoxy group may be arbitrarily substituted
with a halogen atom.)
[0072] When R.sup.6, R.sup.7, and B.sup.3 each independently
represent an alkyl group, an alkyl group having 1 to 10 carbon
atoms is preferable, and an alkyl group having 1 to 5 carbon atoms
is more preferable. In addition, when R.sup.6, R.sup.7, and B.sup.3
each independently represent an alkenyl group, an alkenyl group
having 2 to 10 carbon atoms is preferable, and an alkenyl group
having 2 to 5 carbon atoms is more preferable. In addition, B.sup.3
is preferably a phenyl group which may have a substituent group,
and an alkyl group having 1 to 14 carbon atoms, an alkenyl group
having 2 to 14 carbon atoms, and an alkoxy group having 1 to 14
carbon atoms are preferable as the substituent group, and an alkyl
group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10
carbon atoms, and an alkoxy group having 1 to 10 carbon atoms are
more preferable.
[0073] Examples of the compound denoted by General Formula (I-31)
described above include a compound denoted by General Formula
(I-32) shown below, and
##STR00028##
[0074] (In the formula, R.sup.6 is identical to R.sup.6 of General
Formula (I-31) described above.)
[0075] a compound denoted by General Formula (I-33) shown
below.
##STR00029##
[0076] (In the formula, R.sup.8 and R.sup.9 each independently
represent a hydrogen atom, or an alkyl group having 1 to 14 carbon
atoms, an alkenyl group having 2 to 14 carbon atoms, an alkynyl
group having 2 to 14 carbon atoms, an alkoxy group having 1 to 14
carbon atoms, a cyano group (--CN), and a nitro group (--NO.sub.2),
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CO--, --OCO--, or --COO-- in the manner that oxygen
atoms are not directly adjacent to each other, and one or more
hydrogen atoms of the alkyl group, the alkenyl group, the alkynyl
group, and the alkoxy group may be arbitrarily substituted with a
halogen atom.)
[0077] In addition, examples of the photo-responsive substance
include a compound denoted by General Formula (I-34) shown
below.
##STR00030##
[0078] (In the formula, R.sup.10 to R.sup.13 each independently
represent a hydrogen atom, an alkyl group having 1 to 14 carbon
atoms, an alkenyl group having 2 to 14 carbon atoms, an alkynyl
group having 2 to 14 carbon atoms, an alkoxy group having 1 to 14
carbon atoms, a cyano group (--CN), and a nitro group (--NO.sub.2),
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CO--, --OCO--, or --COO-- in the manner that oxygen
atoms are not directly adjacent to each other, and one or more
hydrogen atoms of the alkyl group, the alkenyl group, the alkynyl
group, and the alkoxy group may be arbitrarily substituted with a
halogen atom.)
[0079] R.sup.10 to R.sup.13 each independently preferably represent
a hydrogen atom and an alkyl group having 1 to 10 carbon atoms in
which a CH.sub.2 group of an alkyl group is substituted with
--COO-- or --OCO--, and more preferably represent a hydrogen atom
and an alkyl group having 1 to 5 carbon atoms in which a CH.sub.2
group of an alkyl group is substituted with --COO-- or --OCO--.
[0080] Examples of the compound denoted by General Formula (I-34)
described above include a compound denoted by General Formula
(I-35) shown below, and
##STR00031##
[0081] (In the formula, R.sup.14 and R.sup.15 each independently
represent a hydrogen atom or an alkyl group having 1 to 10 carbon
atoms.)
[0082] a compound denoted by General Formula (I-36) shown
below.
##STR00032##
[0083] (In the formula, R.sup.14 to R.sup.17 each independently
represent a hydrogen atom or an alkyl group having 1 to 10 carbon
atoms.)
[0084] In addition, examples of the photo-responsive substance
include a compound denoted by General Formula (I-37) shown
below.
##STR00033##
[0085] (In the formula, B.sup.4 represents a hydrogen atom, an
alkyl group having 1 to 14 carbon atoms, an alkenyl group having 2
to 14 carbon atoms, an alkynyl group having 2 to 14 carbon atoms,
an alkoxy group having 1 to 14 carbon atoms, a cyano group (--CN),
a nitro group (--NO.sub.2), a phenyl group which may have a
substituent group (one or more --C.dbd. existing in the group may
be substituted with --N.dbd.), a naphthyl group which may have a
substituent group, a cyclohexyl group which may have a substituent
group (one or more --C-- existing in the group may be substituted
with --O-- or --S--), and NR.sup.18R.sup.19 (R.sup.18 and R.sup.19
each independently represent a hydrogen atom, an alkyl group having
1 to 14 carbon atoms, an alkenyl group having 2 to 14 carbon atoms,
an alkynyl group having 2 to 14 carbon atoms, an alkoxy group
having 1 to 14 carbon atoms, a cyano group (--CN), and a nitro
group (--NO.sub.2), one or more CH.sub.2 groups of the alkyl group
may be substituted with --O--, --CO--, --OCO--, or --COO-- or a
1,4-phenylene group in the manner that oxygen atoms are not
directly adjacent to each other, and one or more hydrogen atoms of
the alkyl group, the alkenyl group, the alkynyl group, and the
alkoxy group may be arbitrarily substituted with a halogen
atom).)
[0086] An alkyl group having 1 to 14 carbon atoms, an alkenyl group
having 2 to 14 carbon atoms which may have a substituent group, and
a phenyl group are preferable as R.sup.18 and R.sup.19 of General
Formula (I-37).
[0087] Examples of the compound denoted by General Formula (I-37)
described above include a compound denoted by General Formula
(I-38) shown below,
##STR00034##
[0088] (In the formula, R.sup.18 and R.sup.19 are identical to
R.sup.18 and R.sup.19 of General Formula (I-37) described
above.)
[0089] a compound denoted by General Formula (I-39) shown below,
and
##STR00035##
[0090] (In the formula, R.sup.20 represents a hydrogen atom or an
alkyl group having 1 to 14 carbon atoms.)
[0091] a compound denoted by General Formula (I-40) shown
below.
##STR00036##
[0092] (In the formula, R.sup.21 represents a hydrogen atom or an
alkyl group having 1 to 14 carbon atoms.)
[0093] In addition, examples of the photo-responsive substance
include a dioxazine-based compound denoted by General Formula
(I-41) shown below.
##STR00037##
[0094] (In the formula, X.sup.1 and X.sup.2 each independently
represent a hydrogen atom, a fluorine atom, or a chlorine atom;
and
[0095] B.sup.5 to B.sup.8 each independently represent a hydrogen
atom, an alkyl group having 1 to 14 carbon atoms, an alkenyl group
having 2 to 14 carbon atoms, an alkynyl group having 2 to 14 carbon
atoms, an alkoxy group having 1 to 14 carbon atoms, a cyano group
(--CN), a nitro group (--NO.sub.2), a phenyl group which may have a
substituent group (one or more --C.dbd. existing in the group may
be substituted with --N.dbd.), a naphthyl group which may have a
substituent group, and a cyclohexyl group which may have a
substituent group (one or more --C-- existing in the group may be
substituted with --O-- or --S--), one or more CH.sub.2 groups of
the alkyl group may be substituted with --O--, --CO--, --OCO--, or
--COO-- in the manner that oxygen atoms are not directly adjacent
to each other, one or more hydrogen atoms of the alkyl group, the
alkenyl group, the alkynyl group, and the alkoxy group may be
arbitrarily substituted with a halogen atom, and n.sub.6 and
n.sub.7 each independently represent 1 to 14.)
[0096] B.sup.5 to B.sup.8 each independently preferably represent
an alkyl group having 1 to 10 carbon atoms, an alkoxy group having
1 to 10 carbon atoms, a phenyl group which may have a substituent
group, and a cyclohexyl group which may have a substituent group,
and an alkyl group having 1 to 10 carbon atoms and an alkoxy group
having 1 to 10 carbon atoms are preferable as the substituent
group.
[0097] Examples of the compound denoted by General Formula (I-41)
described above include a compound denoted by General Formula
(I-42) shown below, and
##STR00038##
[0098] a compound denoted by General Formula (I-43) shown
below.
##STR00039##
[0099] In addition, examples of the photo-responsive substance
include an anthraquinone-based compound denoted by General Formula
(I-44) shown below.
##STR00040##
[0100] (In the formula, B.sup.9 to B.sup.12 each independently
represent a hydrogen atom, a hydroxy group, an alkyl group having 1
to 14 carbon atoms, an alkenyl group having 2 to 14 carbon atoms,
an alkynyl group having 2 to 14 carbon atoms, an alkoxy group
having 1 to 14 carbon atoms, a cyano group (--CN), a nitro group
(--NO.sub.2), a phenyl group which may have a substituent group
(one or more --C.dbd. existing in the group may be substituted with
--N.dbd.), a naphthyl group which may have a substituent group, a
cyclohexyl group which may have a substituent group (one or more
--C-- existing in the group may be substituted with --O-- or
--S--), and NR.sup.18R.sup.19 (R.sup.18 and R.sup.19 each
independently represent a hydrogen atom, an alkyl group having 1 to
14 carbon atoms, an alkenyl group having 2 to 14 carbon atoms, an
alkynyl group having 2 to 14 carbon atoms, an alkoxy group having 1
to 14 carbon atoms, a cyano group (--CN), and a nitro group
(--NO.sub.2), one or more CH.sub.2 groups of the alkyl group may be
substituted with --O--, --CO--, --OCO--, or --COO-- or a
1,4-phenylene group in the manner that oxygen atoms are not
directly adjacent to each other, and one or more hydrogen atoms of
the alkyl group, the alkenyl group, the alkynyl group, and the
alkoxy group may be arbitrarily substituted with a halogen atom);
and
[0101] R.sup.22 to R.sup.25 each independently represent a hydrogen
atom, an alkyl group having 1 to 14 carbon atoms, an alkenyl group
having 2 to 14 carbon atoms, an alkynyl group having 2 to 14 carbon
atoms, an alkoxy group having 1 to 14 carbon atoms, a cyano group
(--CN), and a nitro group (--NO.sub.2), one or more CH.sub.2 groups
of the alkyl group may be substituted with --O--, --CO--, --OCO--,
or --COO-- in the manner that oxygen atoms are not directly
adjacent to each other, and one or more hydrogen atoms of the alkyl
group, the alkenyl group, the alkynyl group, and the alkoxy group
may be arbitrarily substituted with a halogen atom.)
[0102] Examples of the compound denoted by General Formula (I-44)
described above include a compound denoted by General Formula
(I-45) shown below,
##STR00041##
[0103] a compound denoted by General Formula (I-46) shown below,
and
##STR00042##
[0104] a compound denoted by General Formula (I-47) shown
below.
##STR00043##
[0105] In addition, examples of the anthraquinone-based compound
include a compound denoted by General Formula (I-48) shown
below.
##STR00044##
[0106] (In the formula, B.sup.9 to B.sup.12 are each independently
identical to B.sup.9 to B.sup.12 of General Formula (I-44)
described above; and
[0107] R.sup.22, R.sup.23, and R.sup.26 each independently
represent a hydrogen atom, an alkyl group having 1 to 14 carbon
atoms, an alkenyl group having 2 to 14 carbon atoms, an alkynyl
group having 2 to 14 carbon atoms, an alkoxy group having 1 to 14
carbon atoms, a cyano group (--CN), and a nitro group (--NO.sub.2),
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CO--, --OCO--, or --COO-- in the manner that oxygen
atoms are not directly adjacent to each other, and one or more
hydrogen atoms of the alkyl group, the alkenyl group, the alkynyl
group, and the alkoxy group may be arbitrarily substituted with a
halogen atom.)
[0108] Examples of the compound denoted by General Formula (I-48)
described above include a compound denoted by General Formula
(I-49) shown below.
##STR00045##
[0109] Further, examples of the photo-responsive substance include
a compound denoted by General Formula (I-50) shown below,
##STR00046##
[0110] (In the formula, R.sup.27 represents a hydrogen atom, an
alkyl group having 1 to 14 carbon atoms, an alkenyl group having 2
to 14 carbon atoms, an alkynyl group having 2 to 14 carbon atoms,
an alkoxy group having 1 to 14 carbon atoms, a cyano group (--CN),
and a nitro group (--NO.sub.2), one or more CH.sub.2 groups of the
alkyl group may be substituted with --O--, --CO--, --OCO--, or
--COO-- in the manner that oxygen atoms are not directly adjacent
to each other, and one or more hydrogen atoms of the alkyl group,
the alkenyl group, the alkynyl group, and the alkoxy group may be
arbitrarily substituted with a halogen atom.)
[0111] a compound denoted by General Formula (I-51) shown
below,
##STR00047##
[0112] (In the formula, R.sup.28 to R.sup.30 each independently
represent a hydrogen atom, an alkyl group having 1 to 14 carbon
atoms, an alkenyl group having 2 to 14 carbon atoms, an alkynyl
group having 2 to 14 carbon atoms, an alkoxy group having 1 to 14
carbon atoms, a cyano group (--CN), and a nitro group (--NO.sub.2),
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CO--, --OCO--, or --COO-- in the manner that oxygen
atoms are not directly adjacent to each other, and one or more
hydrogen atoms of the alkyl group, the alkenyl group, the alkynyl
group, and the alkoxy group may be arbitrarily substituted with a
halogen atom.)
[0113] a compound denoted by General Formula (I-52) shown
below,
##STR00048##
[0114] a compound denoted by General Formula (I-53) shown
below,
##STR00049##
[0115] a compound denoted by General Formula (I-54) shown
below,
##STR00050##
[0116] (In the formula, R.sup.31 and R.sup.32 each independently
represent a hydrogen atom, an alkyl group having 1 to 14 carbon
atoms, an alkenyl group having 2 to 14 carbon atoms, an alkynyl
group having 2 to 14 carbon atoms, an alkoxy group having 1 to 14
carbon atoms, a cyano group (--CN), and a nitro group (--NO.sub.2),
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CO--, --OCO--, or --COO-- in the manner that oxygen
atoms are not directly adjacent to each other, and one or more
hydrogen atoms of the alkyl group, the alkenyl group, the alkynyl
group, and the alkoxy group may be arbitrarily substituted with a
halogen atom.)
[0117] a compound denoted by General Formula (I-55) shown
below,
##STR00051##
[0118] (In the formula, Y.sup.1 and Y.sup.2 each independently
represent a hydrogen atom, a fluorine atom, an alkyl group having 1
to 14 carbon atoms, an alkenyl group having 2 to 14 carbon atoms,
an alkynyl group having 2 to 14 carbon atoms, an alkoxy group
having 1 to 14 carbon atoms, a cyano group (--CN), and a nitro
group (--NO.sub.2), one or more CH.sub.2 groups of the alkyl group
may be substituted with --O--, --CO--, --OCO--, or --COO-- in the
manner that oxygen atoms are not directly adjacent to each other,
and one or more hydrogen atoms of the alkyl group, the alkenyl
group, the alkynyl group, and the alkoxy group may be arbitrarily
substituted with a halogen atom.)
[0119] a compound denoted by General Formula (I-56) shown below,
and
##STR00052##
[0120] (In the formula, R.sup.33 and R.sup.34 each independently
represent a hydrogen atom, an alkyl group having 1 to 14 carbon
atoms, an alkenyl group having 2 to 14 carbon atoms, an alkynyl
group having 2 to 14 carbon atoms, an alkoxy group having 1 to 14
carbon atoms, a cyano group (--CN), and a nitro group (--NO.sub.2),
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CO--, --OCO--, or --COO-- in the manner that oxygen
atoms are not directly adjacent to each other, and one or more
hydrogen atoms of the alkyl group, the alkenyl group, the alkynyl
group, and the alkoxy group may be arbitrarily substituted with a
halogen atom.)
[0121] a compound denoted by General Formula (I-57) shown
below.
##STR00053##
[0122] (In the formula, R.sup.35 to R.sup.38 each independently
represent a hydrogen atom, an alkyl group having 1 to 14 carbon
atoms, an alkenyl group having 2 to 14 carbon atoms, an alkynyl
group having 2 to 14 carbon atoms, an alkoxy group having 1 to 14
carbon atoms, a cyano group (--CN), and a nitro group (--NO.sub.2),
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CO--, --OCO--, or --COO-- in the manner that oxygen
atoms are not directly adjacent to each other, and one or more
hydrogen atoms of the alkyl group, the alkenyl group, the alkynyl
group, and the alkoxy group may be arbitrarily substituted with a
halogen atom.)
[0123] In General Formula (I-51), General Formula (I-54), General
Formula (I-56), and General Formula (I-57) described above,
R.sup.28 to R.sup.38 are preferably an alkyl group having 1 to 10
carbon atoms and an alkenyl group having 2 to 10 carbon atoms, and
are more preferably an alkyl group having 1 to 5 carbon atoms and
an alkenyl group having 2 to 5 carbon atoms.
[0124] Specifically, examples of the compound denoted by General
Formula (I-56) described above include a compound in which R.sup.33
and R.sup.34 each represent a C.sub.2H.sub.5 group.
[0125] In addition, specifically, examples of the compound denoted
by General Formula (I-57) described above include a compound in
which R.sup.35 to R.sup.38 each represent a C.sub.2H.sub.5
group.
[0126] Among the compounds, the oligothiophene-based compound is
preferable from the viewpoint of a low threshold value of
responding light intensity.
[0127] In addition, a conjugated liquid crystal compound can be
used as the photo-responsive substance. A rod-like liquid crystal
compound is preferable as liquid crystal compound which can
function as such a photo-responsive substance.
[0128] It is preferable that an anisotropic substance be further
contained in the photo-alignment material in a case of being
applied to an alignment film of a liquid crystal display element,
or the like.
[0129] A liquid crystal is used as the anisotropic substance.
[0130] It is preferable that a compound denoted by General Formula
(LC) shown below be contained as the liquid crystal.
##STR00054##
[0131] (In General Formula (LC), R.sup.LC represents an alkyl group
having 1 to 15 carbon atoms, one or more CH.sub.2 groups of the
alkyl group may be substituted with --O--, --CH.dbd.CH--, --CO--,
--OCO--, --COO--, or C.ident.C-- in the manner that oxygen atoms
are not directly adjacent to each other, and one or more hydrogen
atoms of the alkyl group may be arbitrarily substituted with a
halogen atom,
[0132] A.sup.LC1 and A.sup.LC2 each independently represent one
selected from the group consisting of:
[0133] (a) a trans-1,4-cyclohexylene group (in this group, one
CH.sub.2 group or two or more CH.sub.2 groups which are not
adjacent to each other may be substituted with an oxygen atom or a
sulfur atom),
[0134] (b) a 1,4-phenylene group (in this group, one CH group or
two or more CH groups which are not adjacent to each other may be
substituted with a nitrogen atom), and
[0135] (c) a 1,4-bicyclo(2.2.2)octylene group, a
naphthalene-2,6-diyl group, a decahydronaphthalene-2,6-diyl group,
a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, or a chroman-2
6-diyl group,
[0136] one or more hydrogen atoms included in the group (a), the
group (b), or the group (c) described above may be respectively
substituted with F, Cl, CF.sub.3, or OCF.sub.3;
[0137] Z.sup.LC represents a single bond, --CH.dbd.CH--,
--CF.dbd.CF--, --C.ident.C--, --CH.sub.2CH.sub.2--,
--(CH.sub.2).sub.4--, --OCH.sub.2--, --CH.sub.2O--, --OCF.sub.2--,
--CF.sub.2O--, --COO--, or OCO--;
[0138] Y.sup.LC represents a hydrogen atom, a fluorine atom, a
chlorine atom, a cyano group, and an alkyl group having 1 to 15
carbon atoms, one or more CH.sub.2 groups of the alkyl group may be
substituted with --O--, --CH.dbd.CH-, --CO--, --OCO--, --COO--,
--C.ident.C--, --CF.sub.2O--, and --OCF.sub.2-- in the manner that
oxygen atoms are not directly adjacent to each other, one or more
hydrogen atoms of the alkyl group may be arbitrarily substituted
with a halogen atom;
[0139] a represents an integer of 1 to 4, when a represents 2, 3,
or 4;
[0140] when a plurality of A.sup.LC1s exist, the plurality of
A.sup.LC1s may be identical to each other or different from each
other, and
[0141] when a plurality of Z.sup.LCs exist, the plurality of
Z.sup.LCs may be identical to each other or different from each
other.)
[0142] It is preferable that the compound denoted by General
Formula (LC) described above be one or more compounds selected from
a compound group denoted by General Formula (LC1) and General
Formula (LC2) shown below.
##STR00055##
[0143] (In the formula, R.sup.LC11 and R.sup.LC21 each
independently represent an alkyl group having 1 to 15 carbon atoms,
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CH.dbd.CH13 , --CO--, --OCO--, --COO--, or
C.ident.C-- in the manner that oxygen atoms are not directly
adjacent to each other, one or more hydrogen atoms of the alkyl
group may be arbitrarily substituted with a halogen atom;
[0144] A.sup.LC11 and A.sup.LC21 each independently represent any
one of the following structures,
##STR00056##
[0145] (in the structures, one or more CH.sub.2 groups of a
cyclohexylene group may be substituted with an oxygen atom, one or
more CH groups of a 1,4-phenylene group may be substituted with a
nitrogen atom, and one or more hydrogen atoms of the structure may
be substituted with F, Cl, CF.sub.3, or OCF.sub.3);
[0146] X.sup.LC11, X.sup.LC12, and X.sup.LC21 to X.sup.LC23 each
independently represent a hydrogen atom, Cl, F, CF.sub.3, or
OCF.sub.3;
[0147] Y.sup.LC11 and Y.sup.LC21 each independently represent a
hydrogen atom, Cl, F, CN, CF.sub.3, OCH.sub.2F, OCHF.sub.2, or
OCF.sub.3;
[0148] Z.sup.LC11 and Z.sup.LC21 each independently represent a
single bond, --CH.dbd.CH--, --CF.dbd.CF--, --C.ident.C--,
--CH.sub.2CH.sub.2--, --(CH.sub.2).sub.4--, --OCH.sub.2--,
--CH.sub.2O--, --OCF.sub.2--, --CF.sub.2O--, --COO--, or OCO--;
[0149] m.sup.LC11 and m.sup.LC21 each independently represent an
integer of 1 to 4; and
[0150] when a plurality of A.sup.LC11s, A.sup.LC21s, Z.sup.LC11s,
and Z.sup.LC21s exist, the plurality of A.sup.LC11s, A.sup.LC21s,
Z.sup.LC11s, and Z.sup.LC21s may be identical to each other or
different from each other.)
[0151] R.sup.LC11 and R.sup.LC21 each independently preferably
represent an alkyl group having 1 to 7 carbon atoms, an alkoxy
group having 1 to 7 carbon atoms, and an alkenyl group having 2 to
7 carbon atoms, and more preferably represent an alkyl group having
1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms,
and an alkenyl group having 2 to 5 carbon atoms, and even more
preferably represent a straight-chained group, and an alkenyl group
having the following structure is most preferable.
##STR00057##
[0152] (In the formula, a bond with respect to a ring structure is
formed on a right end.)
[0153] It is preferable that A.sup.LC11 and A.sup.LC21 each
independently have the following structure.
##STR00058##
[0154] Y.sup.LC11 and Y.sup.LC21 each independently preferably
represent F, CN, CF.sub.3, or OCF.sub.3, preferably represent F or
OCF.sub.3, and particularly preferably represent F.
[0155] Z.sup.LC11 and Z.sup.LC21 preferably represent a single
bond, --CH.sub.2CH.sub.2--, --COO--, --OCO--, --OCH.sub.2--,
--CH.sub.2O--, --OCF.sub.2--, or CF.sub.2O--, preferably represent
a single bond, --CH.sub.2CH.sub.2--, --OCH.sub.2--, --OCF.sub.2--,
or CF.sub.2O--, and more preferably represent a single bond,
--OCH.sub.2--, or CF.sub.2O--.
[0156] It is preferable that m.sup.LC11 and m.sup.LC21 represent 1,
2, or 3, it is preferable that m.sup.LC11 and m.sup.LC21 represent
1 or 2 in a case of emphasizing preservation stability and response
speed at a low temperature, and it is preferable that m.sup.LC11
and m.sup.LC21 represent 2 or 3 in order to improve the upper limit
value of a nematic phase upper limit temperature.
[0157] It is preferable that the compound denoted by General
Formula (LC1) described above be one or more compounds selected
from the group consisting of compounds denoted by General Formula
(LC1-a) to General Formula (LC1-c) shown below.
##STR00059##
[0158] (In the formula, R.sup.LC11, Y.sup.LC11 , X.sup.LC11, and
X.sup.LC12 are each independently identical to R.sup.LC11,
Y.sup.LC11, X.sup.LC11, and X.sup.LC12 of General Formula (LC1)
described above, A.sup.LC1a1, A.sup.LC1a2, and A.sup.LC1b1
represent a trans-1,4-cyclohexylene group, a
tetrahydropyran-2,5-diyl group, and a 1,3-dioxane-2,5-diyl group,
and X.sup.LC1b1, X.sup.LC1b2, and X.sup.LC1c1 to X.sup.LC1c4 each
independently represent a hydrogen atom, Cl, F, CF.sub.3, or
OCF.sub.3.)
[0159] R.sup.LC11s each independently preferably represent an alkyl
group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7
carbon atoms, and an alkenyl group having 2 to 7 carbon atoms, and
more preferably represent an alkyl group having 1 to 5 carbon
atoms, an alkoxy group having 1 to 5 carbon atoms, and an alkenyl
group having 2 to 5 carbon atoms.
[0160] It is preferable that X.sup.LC11 to X.sup.LC1c4 each
independently represent a hydrogen atom or F.
[0161] It is preferable that Y.sup.LC11s each independently
represent F, CF.sub.3, or OCF.sub.3.
[0162] In addition, it is preferable that the compound denoted by
General Formula (LC1) described above be one or more compounds
selected from the group consisting of compounds denoted by General
Formula (LC1-d)to General Formula (LC1-m) shown below.
##STR00060## ##STR00061##
[0163] (In the formula, R.sup.LC11, Y.sup.LC11, X.sup.LC11, and
X.sup.LC12 are each independently identical to R.sup.LC11,
Y.sup.LC11, X.sup.LC11, and X.sup.LC12 of General Formula (LC1)
described above;
[0164] A.sup.LC1d1, A.sup.LC1f1, A.sup.LC1g1, A.sup.LC1j1,
A.sup.LC1k1, A.sup.LC1k2, and A.sup.LC1m1 to A.sup.LC1m3 represent
a 1,4-phenylene group, a trans-1,4-cyclohexylene group, a
tetrahydropyran-2,5-diyl group, and a 1,3-dioxane-2,5-diyl
group;
[0165] X.sup.LC1d1, X.sup.LC1d2, X.sup.LC1f1, X.sup.LC1f2,
X.sup.LC1g1, X.sup.LC1g2, X.sup.LC1h1, X.sup.LC1h2, X.sup.LC1i1,
X.sup.LC1i2, X.sup.LC1j1 to X.sup.LC1j4, X.sup.LC1k1, X.sup.LC1k2,
X.sup.LC1m1, and X.sup.LC1m2 each independently represent a
hydrogen atom, Cl, F, CF.sub.3, or OCF.sub.3, and
[0166] Z.sup.LC1d1, Z.sup.LC1e1, Z.sup.LC1j1, Z.sup.LC1k1, and
Z.sup.LC1m1 each independently represent a single bond,
--CH.dbd.CH--, --CF.dbd.CF--, --C.ident.C--, --CH.sub.2CH.sub.2--,
--(CH.sub.2).sub.4--, --OCH.sub.2--, --CH.sub.2O--, --OCF.sub.2--,
--CF.sub.2O--, --COO--, or OCO--.)
[0167] R.sup.LC11s each independently preferably represent an alkyl
group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7
carbon atoms, and an alkenyl group having 2 to 7 carbon atoms, and
more preferably represent an alkyl group having 1 to 5 carbon
atoms, an alkoxy group having 1 to 5 carbon atoms, and an alkenyl
group having 2 to 5 carbon atoms.
[0168] It is preferable that X.sup.LC11 to X.sup.LC1m2 each
independently represent a hydrogen atom or F. It is preferable that
Y.sup.LC11s each independently represent F, CF.sub.3, or
OCF.sub.3.
[0169] It is preferable that Z.sup.LC1d1 to Z.sup.LC1m1 each
independently represent --CF.sub.2O-- and --OCH.sub.2--.
[0170] It is preferable that the compound denoted by General
Formula (LC2) described above be one or more compounds selected
from the group consisting of compounds denoted by General Formula
(LC2-a) to General Formula (LC2-g) shown below.
##STR00062##
[0171] (In the formula, R.sup.LC21, Y.sup.LC21, and X.sup.LC21 to
X.sup.LC23 are each independently identical to R.sup.LC21,
Y.sup.LC21, and X.sup.LC21 to X.sup.LC23 of General Formula (LC2)
described above;
[0172] X.sup.LC2d1 to X.sup.LC2d4, X.sup.LC2e1 to X.sup.LC2e4,
X.sup.LC2f1 to X.sup.LC2f4, and X.sup.LC2g1 to X.sup.LC2g4 each
independently represent a hydrogen atom, Cl, F, CF.sub.3, or
OCF.sub.3, and
[0173] Z.sup.LC2a1, Z.sup.LC2b1, Z.sup.LC2c1, Z.sup.LC2d1,
Z.sup.LC2e1, Z.sup.LC2f1, and Z.sup.LC2g1 each independently
represent a single bond, --CH.dbd.CH--, --CF.dbd.CF--,
--C.ident.C--, --CH.sub.2CH.sub.2--, --(CH.sub.2).sub.4--,
--OCH.sub.2--, --CH.sub.2O--, --OCF.sub.2--, --CF.sub.2O--,
--COO--, or OCO--.)
[0174] R.sup.LC21s each independently preferably represent an alkyl
group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7
carbon atoms, and an alkenyl group having 2 to 7 carbon atoms, and
more preferably represent an alkyl group having 1 to 5 carbon
atoms, an alkoxy group having 1 to 5 carbon atoms, and an alkenyl
group having 2 to 5 carbon atoms.
[0175] It is preferable that X.sup.LC21 to X.sup.LC2g4 each
independently represent a hydrogen atom or F, and
[0176] it is preferable that Y.sup.LC21s each independently
represent F, CF.sub.3, or OCF.sub.3.
[0177] It is preferable that Z.sup.LC2a1 to Z.sup.LC2g4 each
independently represent --CF.sub.2O-- and --OCH.sub.2--.
[0178] In addition, it is preferable that the compound denoted by
General Formula (LC) described above be one or more compounds
selected from a compound group denoted by General Formula (LC3) to
General Formula (LC5) shown below.
##STR00063##
[0179] (In the formula, R.sup.LC31, R.sup.LC32, R.sup.LC41,
R.sup.LC42, R.sup.LC51, and R.sup.LC52 each independently represent
an alkyl group having 1 to 15 carbon atoms, one or more CH.sub.2
groups of the alkyl group may be substituted with --O--,
--CH.dbd.CH--, --CO--, --OCO--, --COO--, or C.ident.C-- in the
manner that oxygen atoms are not directly adjacent to each other,
one or more hydrogen atoms of the alkyl group may be arbitrarily
substituted with a halogen atom;
[0180] A.sup.LC31, A.sup.LC32, A.sup.LC41, A.sup.LC42, A.sup.LC51,
and A.sup.LC52 each independently represent any one of the
following structures,
##STR00064##
[0181] (in the structures, one or more CH.sub.2 groups of a
cyclohexylene group may be substituted with an oxygen atom, one or
more CH groups of a 1,4-phenylene group may be substituted with a
nitrogen atom, and one or more hydrogen atoms in the structure may
be substituted with Cl, CF.sub.3, or OCF.sub.3);
[0182] Z.sup.LC31, Z.sup.LC32, Z.sup.LC41, Z.sup.LC42, Z.sup.LC51,
and Z.sup.LC51 each independently represent a single bond,
--CH.dbd.CH--, --C.ident.C--, --CH.sub.2CH.sub.2--,
--(CH.sub.2).sub.4--, --COO--, --OCH.sub.2--, --CH.sub.2O--,
--OCF.sub.2--, or CF.sub.2O--;
[0183] Z.sup.5 represents a CH.sub.2 group or an oxygen atom;
[0184] X.sup.LC41 represents a hydrogen atom or a fluorine
atom,
[0185] m.sup.LC31, m.sup.LC32, m.sup.LC41, m.sup.LC42, m.sup.LC51,
and m.sup.LC52 each independently represent 0 to 3,
m.sup.LC31+m.sup.LC32, m.sup.LC41+m.sup.LC42 and
m.sup.LC51+m.sup.LC52 represent 1, 2, or 3; and
[0186] when a plurality of A.sup.LC31s to A.sup.LC52s, and
Z.sup.LC31s to Z.sup.LC52s exist, the plurality of A.sup.LC31s to
A.sup.LC52s, and Z.sup.LC31s to Z.sup.LC52s may be identical to
each other or different from each other.)
[0187] It is preferable that R.sup.LC31 to R.sup.LC52 each
independently represent an alkyl group having 1 to 7 carbon atoms,
an alkoxy group having 1 to 7 carbon atoms, and an alkenyl group
having 2 to 7 carbon atoms, and an alkenyl group having the
following structure is most preferable,
##STR00065##
[0188] (In the formula, a bond with respect to a ring structure is
formed on a right end.)
[0189] it is preferable that A.sup.LC31 to A.sup.LC52 each
independently represent the following structure, and
##STR00066##
[0190] it is preferable that Z.sup.LC31 to Z.sup.LC51 each
independently represent a single bond, --CH.sub.2O--, --COO--,
--OCO--, --CH.sub.2CH.sub.2--, --CF.sub.2O--, --OCF.sub.2--, or
OCH.sub.2--.
[0191] It is preferable that the compound denoted by General
Formula (LC3) described above be one or more compounds selected
from a compound group denoted by General Formula (LC3-a) and
General Formula (LC3-b) shown below.
##STR00067##
[0192] (In the formula, R.sup.LC31, R.sup.LC32, A.sup.LC31, and
Z.sup.LC31 are each independently identical to R.sup.LC31,
R.sup.LC32, A.sup.LC31, and Z.sup.LC31 of above General Formula
(LC3) described above;
[0193] X.sup.LC3b1 to X.sup.LC3b6 represent a hydrogen atom or a
fluorine atom, a combination of at least one of X.sup.LC3b1 and
X.sup.LC3b2 or X.sup.LC3b3 and X.sup.LC3b4 represents a fluorine
atom;
[0194] m.sup.LC3a1 represents 1, 2, or 3;
[0195] m.sup.LC3b1 represents 0 or 1, and
[0196] when a plurality of A.sup.LC31s and Z.sup.LC31s exist, the
plurality of A.sup.LC31s and Z.sup.LC31s may be identical to each
other or different from each other.)
[0197] It is preferable that R.sup.LC31 and R.sup.LC32 each
independently represent an alkyl group having 1 to 7 carbon atoms,
an alkoxy group having 1 to 7 carbon atoms, an alkenyl group having
2 to 7 carbon atoms, or an alkenyloxy group having 2 to 7 carbon
atoms.
[0198] A.sup.LC31 preferably represents a 1,4-phenylene group, a
trans-1,4-cyclohexylene group, a tetrahydropyran-2,5-diyl group,
and a 1,3-dioxane-2,5-diyl group, and more preferably represents a
1,4-phenylene group and a trans-1,4-cyclohexylene group.
[0199] Z.sup.LC31 preferably represents a single bond,
--CH.sub.2O--, --COO--, --OCO--, and --CH.sub.2CH.sub.2--, and more
preferably represents a single bond.
[0200] It is preferable that General Formula (LC3-a) described
above represent General Formula (LC3-a1) to General Formula
(LC3-a4) shown below.
##STR00068##
[0201] (In the formula, R.sup.LC31 and R.sup.LC32 are each
independently identical to R.sup.LC31 and R.sup.LC32 of General
Formula (LC3) described above.)
[0202] It is preferable that R.sup.LC31 and R.sup.LC32 each
independently represent an alkyl group having 1 to 7 carbon atoms,
an alkoxy group having 1 to 7 carbon atoms, and an alkenyl group
having 2 to 7 carbon atoms, and it is more preferable that
R.sup.LC31 represent an alkyl group having 1 to 7 carbon atoms, and
R.sup.LC32 represent an alkoxy group having 1 to 7 carbon
atoms.
[0203] General Formula (LC3-b) described above preferably
represents General Formula (LC3-b1) to General Formula (LC3-b12)
shown below, more preferably represents General Formula (LC3-b1),
General Formula (LC3-b6), General Formula (LC3-b8), and General
Formula (LC3-b11) shown below, even more preferably represents
General Formula (LC3-b1) and General Formula (LC3-b6) shown below,
and most preferably represents General Formula (LC3-b1) shown
below.
##STR00069## ##STR00070##
[0204] (In the formula, R.sup.LC31 and R.sup.LC32 are each
independently identical to R.sup.LC31 and R.sup.LC32 of General
Formula (LC3) described above.)
[0205] It is preferable that R.sup.LC31 and R.sup.LC32 each
independently represent an alkyl group having 1 to 7 carbon atoms,
an alkoxy group having 1 to 7 carbon atoms, and an alkenyl group
having 2 to 7 carbon atoms, and it is more preferable that
R.sup.LC31 represent an alkyl group having 2 or 3 carbon atoms, and
R.sup.LC32 represent an alkyl group having 2 carbon atoms.
[0206] It is more preferable that General Formula (LC4) described
above be one or more compounds selected from the group consisting
of compounds denoted by General Formula (LC4-a) to General Formula
(LC4-c) shown below, and General Formula (LC5) described above be
one or more compounds selected from the group consisting of
compounds denoted by General Formula (LC5-a) to General Formula
(LC5-c) shown below.
##STR00071##
[0207] (In the formula, R.sup.LC41, R.sup.LC42, and X.sup.LC41 are
each independently identical to R.sup.LC41, R.sup.LC42, and
X.sup.LC41 of General Formula (LC4) described above,
[0208] R.sup.LC51 and R.sup.LC52 are each independently identical
to R.sup.LC51 and R.sup.LC52 of General Formula (LC5) described
above, and
[0209] Z.sup.LC4a1, Z.sup.LC4b1, Z.sup.LC4c1, Z.sup.LC5a1,
Z.sup.LC5b1, and Z.sup.LC5c1 each independently represent a single
bond, --CH.dbd.CH--, --C.ident.C--, --CH.sub.2CH.sub.2--,
--(CH.sub.2).sub.4--, --COO--, --OCH.sub.2--, --CH.sub.2O--,
--OCF.sub.2--, or CF.sub.2O--.)
[0210] It is preferable that R.sup.LC41, R.sup.LC42, R.sup.LC51,
and R.sup.LC52 each independently represent an alkyl group having 1
to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, an
alkenyl group having 2 to 7 carbon atoms, or an alkenyloxy group
having 2 to 7 carbon atoms.
[0211] Z.sup.LC4a1 to Z.sup.LC5c1 each independently preferably
represent a single bond, --CH.sub.2O--, --COO--, --OCO--, and
--CH.sub.2CH.sub.2--, and more preferably represent a single
bond.
[0212] It is preferable that the compound denoted by General
Formula (LC) described above be a liquid crystal composition
containing one or more compounds denoted by General Formula (LC6)
shown below.
##STR00072##
[0213] (In the formula, R.sup.LC61 and R.sup.LC62 each
independently represent an alkyl group having 1 to 15 carbon atoms,
one or more CH.sub.2 groups of the alkyl group may be substituted
with --O--, --CH.dbd.CH--, --CO--, --OCO--, --COO--, or C.ident.C--
in the manner that oxygen atoms are not directly adjacent to each
other, one or more hydrogen atoms of the alkyl group may be
arbitrarily substituted with a halogen, and A.sup.LC61 to
A.sup.LC63 each independently represent any one of the
following,
##STR00073##
[0214] (in the structure, one or more CH.sub.2CH.sub.2 groups of a
cyclohexylene group may be substituted with --CH.dbd.CH--,
--CF.sub.2O--, and --OCF.sub.2--, and one or more CH groups of a
1,4-phenylene group may be substituted with a nitrogen atom);
[0215] Z.sup.LC61 and Z.sup.LC62 each independently represent a
single bond, --CH.dbd.CH--, --C.ident.C--, --CH.sub.2CH.sub.2--,
--(CH.sub.2).sub.4--, --COO--, --OCH.sub.2--, --CH.sub.2O--,
--OCF.sub.2--, or CF.sub.2O--; and
[0216] m.sup.iii1 represents 0 to 3. Here, compounds denoted by
General Formula (LC1) to General Formula (LC5) described above are
excluded.)
[0217] It is preferable that R.sup.LC61 and R.sup.LC62 each
independently represent an alkyl group having 1 to 7 carbon atoms,
an alkoxy group having 1 to 7 carbon atoms, and an alkenyl group
having 2 to 7 carbon atoms, it is most preferable that the alkenyl
group be an alkenyl group having the following structure,
##STR00074##
[0218] (In the formula, a bond with respect to a ring structure is
formed on a right end.)
[0219] it is preferable that A.sup.LC61 to A.sup.LC63 each
independently have the following structure, and
##STR00075##
[0220] it is preferable that Z.sup.LC61 and Z.sup.LC62 each
independently represent a single bond, --CH.sub.2CH.sub.2--,
--COO--, --OCH.sub.2--, --CH.sub.2O--, --OCF.sub.2--, or
CF.sub.2O--.
[0221] It is more preferable that General Formula (LC6) described
above be one or more compounds selected from the group consisting
of compounds denoted by General Formula (LC6-a) to General Formula
(LC6-m) shown below.
##STR00076## ##STR00077##
[0222] (In the formula, R.sup.LC61 and R.sup.LC62 each
independently represent an alkyl group having 1 to 7 carbon atoms,
an alkoxy group having 1 to 7 carbon atoms, an alkenyl group having
2 to 7 carbon atoms, or an alkenyloxy group having 2 to 7 carbon
atoms.)
[0223] In addition, the liquid crystal may be any one of a rod-like
liquid crystal (a nematic liquid crystal and a smectic liquid
crystal), a disk-like (discotic) liquid crystal, a bending type
liquid crystal (a banana liquid crystal), and a liquid crystal in
which chirality is imparted to the liquid crystal described
above.
[0224] The type of liquid crystal (a rod-like liquid crystal, a
disk-like liquid crystal, or a bending type liquid crystal) is
suitably selected in order to obtain desired refractive index
anisotropy. When high responsibility is necessary, a nematic liquid
crystal, which is a liquid crystal close to a liquid, is
preferable, and when stable alignment properties are necessary, a
smectic liquid crystal which is close to a solid is preferably
used. It is possible to use a unique liquid crystal phase in a
chiral liquid crystal, and in this case, a liquid crystal in which
a part or all thereof is chiral may be used or a liquid crystal and
a chiral non-liquid crystal may be mixed. In addition, any one of a
monomer, a dimer, a multimer (an oligomer) of greater than or equal
to a trimer, and a polymer may be used as the liquid crystal. When
high responsibility is necessary, a monomer is preferable, and when
stable alignment properties are necessary, a dimer, a multimer (an
oligomer) of greater than or equal to a trimer, and a polymer are
preferable.
[0225] When the anisotropic substance is contained in the
photo-alignment material, a ratio of the photo-responsive substance
in the photo-alignment material is preferably greater than or equal
to 0.01 mol % and less than or equal to 30 mol %, and more
preferably greater than or equal to 0.05 mol % and less than or
equal to 10 mol %, in a molar ratio.
[0226] When the ratio of the photo-responsive substance in the
photo-alignment material is in the range described above, the
photo-alignment material is irradiated with light such that light
intensity is greater than or equal to a threshold value, and thus,
it is possible to easily align the anisotropic substance contained
in the photo-alignment material in an arbitrary direction according
to the alignment of the photo-responsive substance.
[0227] Furthermore, here, the arbitrary direction in which the
photo-responsive substance and the anisotropic substance are
aligned is a direction in which a long axis direction of the
substance (molecules) is parallel to a vibration direction of the
light.
[0228] In order to reduce the threshold value of the light
intensity, the photo-alignment material can contain an oligomer
and/or a polymer.
[0229] In this case, the oligomer and/or the polymer may be mixed
in a photo-alignment material, or a low-molecular-weight compound
having a polymerizable group may be mixed and then may be
polymerized.
[0230] In particular, examples of the oligomer and/or the polymer
include polyacrylate, polymethacrylate, polyacrylamide,
polymethacrylamide, polymethyl methacrylate, and the like. A degree
of polymerization or the presence or absence of liquid
crystallinity may be determined in consideration of solubility with
respect to the photo-alignment material.
[0231] The low-molecular-weight compound having a polymerizable
group may have liquid crystallinity or may not have liquid
crystallinity, and it is preferable that the low-molecular-weight
compound having a polymerizable group have liquid crystallinity.
Furthermore, having liquid crystallinity indicates including a
rigid portion referred to as mesogen and having alignment
properties. Examples of the polymerizable compound having liquid
crystallinity include a rod-like polymerizable liquid crystal
compound having a rigid portion referred to as mesogen in which a
plurality of structures are connected, such as a 1,4-phenylene
group and 1,4-cyclohexylene group and a (meth)acryloyl oxy group,
and a polymerizable functional group such as a vinyl oxy group and
an epoxy group, as disclosed in Japanese Unexamined Patent
Application, First Publication No. H7-294735, Japanese Unexamined
Patent Application, First Publication No. H8-3111, Japanese
Unexamined Patent Application, First Publication No. H8-29618,
Japanese Unexamined Patent Application, First Publication No.
H11-80090, Japanese Unexamined Patent Application, First
Publication No. H11-148079, Japanese Unexamined Patent Application,
First Publication No. 2000-178233, Japanese Unexamined Patent
Application, First Publication No. 2002-308831, and Japanese
Unexamined Patent Application, First Publication No. 2002-145830,
or Handbook of Liquid Crystals (edited by D. Demus, J. W. Goodby,
G. W. Gray, H. W. Spiess, V. Vill, published by Wiley-VCH Verlag
GmbH & Co., 1998), Kikan Kagaku Sosetsu No. 22, Liquid Crystal
Chemistry (The Chemical Society of Japan, 1994), a rod-like
polymerizable liquid crystal compound having a maleimide group as
disclosed in Japanese Unexamined Patent Application, First
Publication No. 2004-2373 and Japanese Unexamined Patent
Application, First Publication No. 2004-99446, a rod-like
polymerizable liquid crystal compound having an allyl ether group
as disclosed in Japanese Unexamined Patent Application, First
Publication No. 2004-149522, or a discotic polymerizable compound
disclosed in, for example, Handbook of Liquid Crystals (edited by
D. Demus, J. W. Goodby, G. W. Gray, H. W. Spiess, V. Vill,
published by Wiley-VCH Verlag GmbH & Co., 1998), Kikan Kagaku
Sosetsu No.22, Liquid Crystal Chemistry (The Chemical Society of
Japan, 1994), or Japanese Unexamined Patent Application, First
Publication No. H07-146409.
[0232] The total content of the oligomer and/or the polymer in the
photo-alignment material is preferably greater than or equal to 0.1
mol % and less than or equal to 15 mol %, more preferably greater
than or equal to 2 mol % and less than or equal to 13 mol %, and
even more preferably greater than or equal to 5 mol % and less than
or equal to 11 mol %.
[0233] When the content of the oligomer and/or the polymer in the
photo-alignment material is in the range described above, it is
possible to reduce the threshold value of the light intensity.
[0234] When the oligomer is added to the photo-alignment material,
and even a polymerization initiator does not exist, polymerization
progresses, and the polymerization initiator may be contained in
order to accelerate polymerization. Examples of the polymerization
initiator include benzoin ethers, benzophenones, acetophenones,
benzyl ketals, acyl phosphine oxides, and the like.
[0235] When the photo-alignment material of the present invention
is irradiated with light, the photo-responsive substance contained
in the photo-alignment material is aligned such that the long axis
direction thereof is parallel to the vibration direction of the
light. For this reason, for example, alignment of anisotropic
molecules is controlled by the light, and thus, a refractive index
of the photo-alignment material can be spatially and regionally
modulated or distributed. Accordingly, the photo-alignment material
is used as an optical anisotropic material of an optical element
exhibiting an optical function. Specifically, the photo-alignment
material is applied to a display element controlling a transmitted
light quantity of the light by using birefringence of the
anisotropic substance (the liquid crystal), such as a liquid
crystal display element or electronic paper, a lens, a retardation
film, a hologram, an alignment film, a 3D printer, a prism, a
mirror, a filter, and the like. When the anisotropic substance is
contained in the photo-alignment material, when the photo-alignment
material is irradiated with the light, and the photo-responsive
substance is aligned, according to this, the anisotropic substance
is also aligned such that the long axis direction thereof is
parallel to the vibration direction of the light.
[0236] When the photo-alignment material of the present invention
is applied to the alignment film, for example, the photo-alignment
material is applied to an alignment film of a liquid crystal
display element.
[0237] When the photo-alignment material of the present invention
is applied to the liquid crystal display element, an alignment film
formed of the alignment material of the present invention is formed
on a substrate of the liquid crystal display element.
[0238] The liquid crystal display element is useful to an active
matrix liquid crystal display (AM-LCD) element, a twisted nematic
(TN) liquid crystal display element, a super-twisted nematic liquid
crystal display (STN-LCD) element, OCB-LCD, an in-plane switching
liquid crystal display (IPS-LCD) element, and a liquid crystal
display element in a fringe-field switching (FFS) mode, is
particularly useful to AM-LCD including an active matrix address
device, and can be used in a transmission type or reflection type
liquid crystal display element.
[0239] According to the photo-alignment material of the present
invention, the photo-alignment material containing the
photo-responsive substance having a threshold value of responding
light intensity is irradiated with light having light intensity of
greater than or equal to the threshold value, and thus, the
photo-responsive substance contained in the photo-alignment
material is aligned. The photo-responsive substance is aligned to
be parallel to the vibration direction of the light, and thus, it
is possible to easily control a tilt angle of the alignment
film.
[0240] [Photo-Alignment Method]
[0241] A photo-alignment method of the present invention is a
method using the photo-alignment material of the present invention,
and is a method in which the photo-alignment material containing
the photo-responsive substance having a threshold value of
responding light intensity is irradiated with light having light
intensity of greater than or equal to the threshold value, and the
photo-responsive substance contained in the photo-alignment
material is aligned.
[0242] The same photo-responsive substances as those used in the
photo-alignment material of the present invention are used as the
photo-responsive substance.
[0243] In addition, the oligomer and/or the polymer can be further
contained in the photo-alignment material, as with the
photo-alignment material of the present invention.
[0244] In addition, the anisotropic substance can be further
contained in the photo-alignment material, as with the
photo-alignment material of the present invention.
[0245] Here, a photo-alignment method in a case of manufacturing
the alignment film by using the photo-alignment material of the
present invention will be exemplified.
[0246] Light irradiation is performed with respect to the
photo-alignment material of the present invention, and thus, the
photo-responsive substance, or the photo-responsive substance and
the anisotropic substance can be aligned.
[0247] <Manufacturing Method of Alignment Film>
[0248] Examples of a manufacturing method of an alignment film
include a method in which the photo-alignment material is dissolved
in a solvent and is applied onto a substrate, a coating film is
formed, and then, the coating film is irradiated with light, and
the photo-responsive substance is aligned such that the long axis
direction thereof is parallel to a vibration direction of polarized
light. In addition, examples of a manufacturing method of an
alignment film include a method in which when the photo-alignment
material contains the anisotropic substance, the coating film is
irradiated with light, and the photo-responsive substance is
aligned such that the long axis direction thereof is parallel to
the vibration direction of the light, and thus, the anisotropic
substance is aligned such that the long axis direction thereof is
parallel to the vibration direction of the light.
[0249] It is preferable that the solvent used for dissolving the
photo-alignment material be a solvent which dissolves the
photo-alignment material of the present invention and other
components to be arbitrarily used and not react therewith, examples
of the solvent include an organic solvent such as
1,1,2-trichloroethane, N-methyl pyrrolidone, butoxy ethanol,
.gamma.-butyrolactone, ethylene glycol, polyethylene glycol
monomethyl ether, propylene glycol, 2-pyrrolidone, N,N-dimethyl
formamide, phenoxy ethanol, tetrahydrofuran, dimethyl sulfoxide,
methyl isobutyl ketone, and cyclohexanone, and two or more of
organic solvents may be used in combination.
[0250] Examples of the material of the substrate forming the
alignment film include glass, silicon, polyethylene terephthalate,
polybutylene terephthalate, polyether sulfone, polycarbonate,
triacetyl cellulose, and the like.
[0251] When the substrate is used for the liquid crystal display
element, an electrode layer such as an ITO film formed of Cr, Al,
and In.sub.2O.sub.3--SnO.sub.2, and an NESA layer formed of
SnO.sub.2 may be disposed on the substrate, and the electrode layer
is patterned by using a photoetching method or a method using a
mask at the time of forming the electrode layer.
[0252] Further, a color filter layer or the like may be formed on
the substrate.
[0253] Examples of a method of applying a solution containing the
photo-alignment material onto the substrate include a method such
as spin coating, die coating, gravure coating, flexo printing, and
ink jet printing.
[0254] It is preferable that a solid content concentration of the
solution at the time of being applied be 0.5 mass % to 10 mass %,
and it is more preferable that the solid content concentration be
selected from the range in consideration of a method of applying
the solution onto the substrate, viscosity, volatility, and the
like.
[0255] In addition, it is preferable that the coating surface be
heated after being coated, and thus, the solvent is removed, and in
drying conditions, a drying temperature be preferably 50.degree. C.
to 300.degree. C., and more preferably 80.degree. C. to 200.degree.
C., and a drying times be preferably 5 minutes to 200 minutes, and
more preferably 10 minutes to 100 minutes.
[0256] The coating film formed by the method described above is
subjected to linear polarized light irradiation from a normal
direction of the coating film surface (a normal direction of the
coating film containing the photo-alignment material), and
non-polarized light irradiation or linear polarized light
irradiation from an oblique direction with respect to a normal
direction of the coating film surface (a normal direction of the
coating film containing the photo-alignment material), and thus,
the photo-responsive substance, or the photo-responsive substance
and the anisotropic substance can be aligned. In addition, the
linear polarized light irradiation from the normal direction of the
coating film surface, and the non-polarized light irradiation or
the linear polarized light irradiation from the oblique direction
with respect to the normal direction of the coating film surface
may be performed in combination. In order to apply a desired
pretilt angle to the alignment film, the linear polarized light
irradiation from the oblique direction with respect to the normal
direction of the coating film surface is preferable.
[0257] The light to be irradiated to the photo-alignment material
is irradiated from the oblique direction with respect to the normal
direction of the coating film containing the photo-alignment
material, and thus, for example, even when the photo-responsive
substance is aligned such that the long axis direction thereof is
perpendicular to the vibration direction of the light before light
irradiation, the light can be irradiated from the oblique direction
with respect to the long axis direction of the photo-responsive
substance. Accordingly, the photo-responsive substance can be
efficiently aligned such that the long axis direction thereof is
parallel to the vibration direction of the light. Further, when the
photo-alignment material is irradiated with the light, an angle
with respect to a normal direction of a layer containing the
photo-alignment material is preferably greater than or equal to 0
degrees and less than or equal to 15 degrees, and more preferably
greater than or equal to 0 degrees and less than or equal to 10
degrees, and the photo-responsive substance can be more efficiently
aligned such that the long axis direction thereof is parallel to
the vibration direction of the light.
[0258] For example, an ultraviolet ray and a visible light ray
including light having a wavelength of 150 nm to 800 nm can be used
as the light to be irradiated to the coating film, and an
ultraviolet ray of 270 nm to 450 nm is particularly preferable.
[0259] Examples of a light source include a xenon lamp, a
high-pressure mercury lamp, a super-high-pressure mercury lamp, a
metal halide lamp, and the like. Linear polarized light can be
obtained by using a polarization filter or a polarization prism
with respect to light from the light source. In addition,
ultraviolet light and visible light obtained from the light source
may limit an irradiation wavelength range by using an interference
filter, a color filter, or the like.
[0260] In addition, examples of the manufacturing method of an
alignment film can include a method in which the photo-alignment
material containing any one of the low-molecular-weight compound
having a polymerizable group, the oligomer, and the polymer is
used, the photo-alignment material is dissolved in the solvent
described above and is applied onto the substrate, the coating film
is formed, and then, the coating film is heated or irradiated with
light, each of the low-molecular-weight compounds having a
polymerizable group and/or the oligomer are polymerized, and thus,
alignment control is exhibited, and the alignment film is obtained.
In addition, the alignment of the photo-responsive substance or the
anisotropic substance and the exhibition of the alignment control
due to the polymerization of the low-molecular-weight compound
having a polymerizable group and/or the oligomer may be
simultaneously performed by the light irradiation with respect to
the photo-alignment material, or the alignment of the
photo-responsive substance or the anisotropic substance and the
exhibition of alignment control due to the polymerization of the
low-molecular-weight compound having a polymerizable group and/or
the oligomer may be separately performed by a method of using two
or more types of light rays having different wavelengths in
combination.
[0261] In addition, in all of the manufacturing methods of an
alignment film, an alignment film is further manufactured on the
substrate on which the alignment film is formed in advance, and
thus, it is possible to impart control of an alignment direction
and an alignment angle due to the photo-alignment material of the
present invention to the substrate.
[0262] In addition, when the photo-alignment material of the
present invention is used, the low-molecular-weight compound having
a polymerizable group and/or the oligomer are subjected to thermal
polymerization in the heating step described above, and it is
possible to prepare a polymer on the substrate, and in this case,
it is preferable that the polymerization initiator be contained in
the photo-alignment material. Alternatively, the solvent is removed
in the heating step described above, and then, non-polarized light
is irradiated, and the low-molecular-weight compound having a
polymerizable group and/or the oligomer are subjected to
photopolymerization. Therefore, it is possible to prepare a polymer
on the substrate, and it is possible to use the thermal
polymerization and the photopolymerization in combination.
[0263] When the polymer is prepared on the substrate by the thermal
polymerization, the heating temperature is not particularly limited
insofar as the polymerization of the low-molecular-weight compound
having a polymerizable group and/or the oligomer sufficiently
progresses, and in general, the heating temperature is
approximately 50.degree. C. to 250.degree. C., and more preferably
approximately 70.degree. C. to 200.degree. C. In addition, the
polymerization initiator may or may not be added to the
photo-alignment material.
[0264] When the polymer is prepared on the substrate by the
photopolymerization, it is preferable that an ultraviolet ray of
non-polarized light be used in the light irradiation. In addition,
it is preferable that the polymerization initiator not be contained
in the photo-alignment material.
[0265] The film thickness of the alignment film formed by the
manufacturing method described above is preferably approximately 10
nm to 250 nm, and more preferably approximately 10 nm to 100
nm.
[0266] In the present invention, the alignment indicates a
direction when the anisotropic substance such as the
photo-responsive substance contained in the photo-alignment
material or the liquid crystal contained in the photo-alignment
material is directed towards a predetermined direction, indicates a
direction of a molecular long axis in a case of rod-like molecules,
and indicates a normal direction with respect to a disk surface in
a case of disk-like molecules.
[0267] In the present invention, the pretilt angle indicates an
angle between the alignment direction of the liquid crystal
molecules or the polymerizable liquid crystal molecules and the
substrate surface.
[0268] In the present invention, an optical axis indicates a
direction in which a refractive index is constant, birefringence
does not occur even when light which is not polarized is incident,
and a normal light ray and an abnormal light ray are coincident
with each other or a shift between the normal light ray and the
abnormal light ray is minimized, in the liquid crystal display
element or the optical anisotropic body.
[0269] In the present invention, the polymerizable liquid crystal
indicates a compound which exhibits a liquid crystal phase and has
a polymerizable chemical structure.
[0270] In the present invention, homogeneous alignment indicates
alignment in which a pretilt angle is greater than or equal to 0
degrees and less than or equal to 20 degrees.
[0271] In the present invention, homeotropic alignment indicates
alignment in which a pretilt angle is greater than or equal to 70
degrees and less than or equal to 90 degrees. An angle of the
optical axis with respect to the substrate surface and the pretilt
angle may or may not be coincident with each other.
[0272] [Manufacturing Method of Liquid Crystal Display Element]
[0273] For example, it is possible to manufacture a liquid crystal
cell in which a liquid crystal composition is interposed between a
pair of substrates, and a liquid crystal display element using the
liquid crystal cell by using the alignment film formed by the
method described above, as follows.
[0274] A liquid crystal cell can be manufactured by preparing two
substrates on which an alignment film is formed, and by arranging a
liquid crystal that is arranged between the two substrates. In
addition, the alignment film described above may be formed on only
one substrate of the two substrates.
[0275] Examples of a manufacturing method of a liquid crystal cell
include the following methods.
[0276] First, two substrates are arranged such that alignment films
thereof face each other, a peripheral portion is bonded by using a
sealing agent in a state where a predetermined gap (a cell gap) is
maintained between the two substrates, injection and filling of a
liquid crystal is performed with respect to the cell gap
partitioned by the substrate surface and the sealing agent, and
then, an injection hole is sealed. Therefore, it is possible to
manufacture a liquid crystal cell.
[0277] In addition, the liquid crystal cell can also be
manufactured by a method referred to as a One Drop Fill (ODF)
method. As a sequence thereof, for example, an ultraviolet curable
sealing agent is applied to a predetermined portion on a substrate
on which an alignment film is formed, a liquid crystal is dripped
onto the surface of the alignment film, another substrate is then
bonded such that the alignment films face each other, and after
that, the entire substrate is irradiated with ultraviolet light,
and a sealing agent is cured. Therefore, it is possible to
manufacture a liquid crystal cell.
[0278] Even when the liquid crystal cell is manufactured by any
method, it is preferable that fluid alignment in a case of
performing injection be removed by performing heating up to a
temperature at which the used liquid crystal has an isotropic
phase, and then, by gradually performing cooling to room
temperature.
[0279] For example, an epoxy resin or the like can be used as the
sealing agent.
[0280] In addition, in order to maintain the cell gap to be
constant, it is possible to use beads such as silica gel, alumina,
and an acrylic resin as a spacer before bonding the two substrates,
and the spacer may be sprayed onto a coating film of the alignment
film, or the two substrates may be bonded after mixing the spacer
and the sealing agent.
[0281] A polarizing plate is bonded to the outer surface of the
liquid crystal cell manufactured as described above, and thus, it
is possible to obtain a liquid crystal display element.
[0282] Examples of the polarizing plate include a polarizing plate
formed of an "H film" in which iodine is absorbed while stretching
and aligning polyvinyl alcohol, a polarizing plate in which the H
film is interposed between cellulose acetate protective films, or
the like.
[0283] [Manufacturing Method of Optical Anisotropic Body]
[0284] For example, it is possible to manufacture an optical
anisotropic body such as a retardation film, which is useful in an
optical anisotropic film used for optical compensation of the
liquid crystal display element, by using the alignment film formed
by the method described above, as follows.
[0285] When a polymerizable liquid crystal composition is applied
onto the alignment film, a known and common coating method such as
bar coating, spin coating, roll coating, gravure coating, spray
coating, die coating, cap coating, and a dipping method may be
used.
[0286] At this time, in order to increase coating properties, a
known and common organic solvent may be added to the polymerizable
liquid crystal composition. In this case, the organic solvent is
removed by performing natural drying, heat drying, decompression
drying, decompression heat drying, and the like after the
polymerizable liquid crystal composition is applied onto the
alignment film.
[0287] In order to obtain the optical anisotropic body by using the
alignment film, the polymerizable liquid crystal composition is
applied onto the alignment film, and polymerization is performed in
a state where the polymerizable liquid crystal composition is
aligned. Examples of a method of polymerizing the polymerizable
liquid crystal composition include a method of irradiating an
active energy ray, a thermal polymerization method, and the like.
The polymerizable liquid crystal composition contains a
polymerizable compound. Examples of the polymerizable compound
which can be used include a photopolymerizable monomer or the like
in which polymerization progresses by an energy ray such as
light.
[0288] Specifically, a bifunctional monomer denoted by General
Formula (II) shown below is preferable.
##STR00078##
[0289] (In the formula, X.sup.41 and X.sup.42 each independently
represent a hydrogen atom or a methyl group, Sp.sup.41 and
Sp.sup.42 each independently represent a single bond, an alkylene
group having 1 to 8 carbon atoms, or --O--(CH.sub.2)s-(in the
formula, s represents an integer of 2 to 7, and an oxygen atom is
bonded to an aromatic ring), Z.sup.41 represents --OCH.sub.2--,
--CH.sub.2O--, --COO--, --OCO--, --CF.sub.2O--, --OCF.sub.2--,
--CH.sub.2CH.sub.2--, --CF.sub.2CF.sub.2--, --CH.dbd.CH--COO--,
--CH.dbd.CH--OCO--, --COO--CH.dbd.CH--, --OCO--CH.dbd.CH--,
--COO--CH.sub.2CH.sub.2--, --OCO--CH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2--COO--, --CH.sub.2CH.sub.2--OCO--,
--COO--CH.sub.2--, --OCO--CH.sub.2--, --CH.sub.2--COO--,
--CH.sub.2--OCO--, --CY.sup.1.dbd.CY.sup.2-- (in the formula,
Y.sup.1 and Y.sup.2 each independently represent a fluorine atom or
a hydrogen atom), --C.ident.C--, or a single bond,
[0290] M.sup.41 represents a 1,4-phenylene group, a
trans-1,4-cyclohexylene group, or a single bond, and in all of the
1,4-phenylene groups of the formula, an arbitrary hydrogen atom may
be substituted with a fluorine atom.)
[0291] A diacrylate derivative in which both of X.sup.41 and
X.sup.42 represent a hydrogen atom and a dimethacrylate derivative
in which both of X.sup.41 and X.sup.42 have a methyl group are
preferable, and a compound in which one of X.sup.41 and X.sup.42
represents a hydrogen atom, and the other has a methyl group is
also preferable. In a polymerization rate of the compound, a
polymerization rate of the diacrylate derivative is the fastest, a
polymerization rate of the dimethacrylate derivative is the
slowest, and a polymerization rate of an asymmetrical compound is
between the polymerization rates of the diacrylate derivative and
the dimethacrylate derivative, and a preferred aspect can be used
according to the application.
[0292] Sp.sup.41 and Sp.sup.42 each independently represent a
single bond, an alkylene group having 1 to 8 carbon atoms, or
--O--(CH.sub.2)s-, and in a PSA display element, it is preferable
that at least one of Sp.sup.41 and Sp.sup.42 be a single bond, and
a compound in which both of Sp.sup.41 and Sp.sup.42 represent a
single bond or an aspect in which one of Sp.sup.41 and Sp.sup.42
represents a single bond, and the other represents an alkylene
group having 1 to 8 carbon atoms or --O--(CH.sub.2)s-. In this
case, 1 to 4 alkyl groups are preferable, and s is preferably 1 to
4.
[0293] Z.sup.41 preferably represents --OCH.sub.2--, --CH.sub.2O--,
--COO--, --OCO--, --CF.sub.2O--, --OCF.sub.2--,
--CH.sub.2CH.sub.2--, --CF.sub.2CF.sub.2--, or a single bond, more
preferably represents --COO--, --OCO--, or a single bond, and
particularly preferably represents a single bond.
[0294] M.sup.41 represents a 1,4-phenylene group in which an
arbitrary hydrogen atom may be substituted with a fluorine atom, a
trans-1,4-cyclohexylene group, or a single bond, and preferably
represents a 1,4-phenylene group or a single bond. When M.sup.41
represents a ring structure other than a single bond, it is also
preferable that Z.sup.41 represent a linking group other than a
single bond, and when M.sup.41 represents a single bond, it is
preferable that Z.sup.41 represent a single bond.
[0295] From this viewpoint, in General Formula (II) described
above, specifically, it is preferable that a ring structure between
Sp.sup.41 and Sp.sup.42 have the following structure.
[0296] In General Formula (II) described above, when M.sup.41
represents a single bond, and the ring structure is formed of two
rings, the ring structure preferably represents General Formula
(IIa-1) to General Formula (IIa-5) shown below, more preferably
represents General Formula (IIa-1) to General Formula (IIa-3), and
particularly preferably represents General Formula (IIa-1).
##STR00079##
[0297] (In the formula, both terminals are bonded to Sp.sup.41 and
Sp.sup.42.)
[0298] In a polymerizable compound having such a skeleton, an
alignment-regulating force after polymerization is optimized for a
PSA type liquid crystal display element, and an excellent alignment
state can be obtained. Therefore, display unevenness is suppressed
or does not occur.
[0299] As described above, compounds denoted by General Formula
(II-1) to General Formula (II-4) shown below are particularly
preferable as the photopolymerizable monomer, and among the
compounds, a compound denoted by General Formula (II-2) shown below
is most preferable.
##STR00080##
[0300] (In the formula, Sp.sup.50 represents an alkylene group
having 2 to 5 carbon atoms.)
[0301] When the photopolymerizable monomer is added to the
polymerizable liquid crystal composition of the present invention
and even the polymerization initiator does not exist, the
polymerization progresses, but the polymerization initiator may be
contained in order to accelerate the polymerization. Examples of
the polymerization initiator include benzoin ethers, benzophenones,
acetophenones, benzyl ketals, acyl phosphine oxides, and the
like.
[0302] A polymerization operation of the polymerizable liquid
crystal composition is simple in a case of a method of irradiating
an active energy ray, and thus, a method is preferable in which
photopolymerization is performed by irradiation of light such as an
ultraviolet ray. In a case of photopolymerization, the
photopolymerization may be performed by the same method as that in
a case of preparing the alignment film by photopolymerization. The
irradiation intensity of the ultraviolet ray is preferably in a
range of 1 W/m.sup.2 to 10 kW/m.sup.2, and is particularly
preferably in a range of 5 W/m.sup.2 to 2 kW/m.sup.2.
[0303] It is preferable that the polymerization of the
polymerizable liquid crystal composition by heating be performed at
a temperature at which the polymerizable liquid crystal composition
exhibits a liquid crystal phase or a temperature lower than the
temperature described above, and when a thermal polymerization
initiator which discharges radicals by heating is used, it is
particularly preferable that a thermal polymerization initiator of
which a cleavage temperature is in the temperature range described
above be used. In addition, it is possible to use the thermal
polymerization initiator and the photopolymerization initiator in
combination. The heating temperature also depends on a transition
temperature from a liquid crystal phase to an isotropic phase of
the polymerizable liquid crystal composition, and the heating is
preferably performed at a temperature lower than a temperature at
which heterogeneous polymerization occurs due to heat. The heating
temperature is preferably 20.degree. C. to 300.degree. C., more
preferably 30.degree. C. to 200.degree. C., and particularly
preferably 30.degree. C. to 120.degree. C. In addition, for
example, when a polymerizable group is a (meth)acryloyl oxy group,
it is preferable that the heating be performed at a temperature
lower than 90.degree. C.
[0304] In the present invention, the optical axis of the optical
anisotropic body can be adjusted by controlling the pretilt angle
using the photo-alignment layer, and in order to set an angle of
the optical axis with respect to the substrate surface to 0 degrees
to 45 degrees, it is preferable that the pretilt angle be 0 degrees
to 45 degrees, and in order to set the angle of the optical axis to
the substrate surface to 45 degrees to 90 degrees, it is preferable
that the pretilt angle be 45 degrees to 90 degrees.
[0305] Examples of a manufacturing step of the alignment film and
the optical anisotropic body include the following methods.
[0306] A film formed of the photo-alignment material described
above is prepared on the substrate, as a first step.
[0307] The film formed of the photo-alignment material is
irradiated with light of greater than or equal to a threshold value
of necessary light intensity in order to align a photo-responsive
substance, at least the photo-responsive substance is aligned,
alignment control is imparted to the film, and an alignment film is
formed, as a second step.
[0308] A polymerizable liquid crystal composition film is prepared
on the alignment film, as a third step.
[0309] The polymerizable liquid crystal composition film is
polymerized, and an optical anisotropic body is formed, as a fourth
step. At this time, in the fourth step, a polymerization reaction
and a cross-linking reaction may simultaneously progress in the
alignment film.
[0310] In addition, examples of another manufacturing method
include the following methods.
[0311] A film formed of the photo-alignment material is prepared on
a substrate, as a first step.
[0312] A polymerizable liquid crystal composition film is prepared
on an alignment film, as a second step.
[0313] The film formed of the photo-alignment material and the
polymerizable liquid crystal composition film is irradiated with
light of greater than or equal to a threshold value of necessary
light intensity in order to align a photo-responsive substance, at
least the photo-responsive substance is aligned, alignment control
is imparted to the film, and an alignment film is formed, as a
third step.
[0314] The polymerizable liquid crystal composition film is
polymerized, and an optical anisotropic body is formed, as a fourth
step.
[0315] Furthermore, the third step and the fourth step may
simultaneously progress. Accordingly, it is possible to reduce the
number of steps.
[0316] By repeating the steps a plurality of times, it is possible
to laminate the optical anisotropic body over a plurality of
layers.
[0317] That is, the alignment film and the optical anisotropic body
may be laminated on the optical anisotropic body after the optical
anisotropic body is formed on the alignment film, or the optical
anisotropic body may be further laminated after the optical
anisotropic body is formed on the alignment film.
[0318] The optical an isotropic body having a plurality of optical
anisotropic body layers obtained as described above can be used in
applications such as simultaneously performing optical compensation
of a liquid crystal layer and a polarizing plate of a liquid
crystal display element, simultaneously performing optical
compensation and brightness improvement of the liquid crystal layer
of the liquid crystal display element, or simultaneously performing
optical compensation and brightness improvement of the polarizing
plate of the liquid crystal display element.
[0319] In addition, when only a specific portion is polymerized by
ultraviolet irradiation using a mask and then an alignment state of
an unpolymerized portion is changed over an electric field, a
magnetic field, a temperature, or the like, and after that, the
unpolymerized portion is polymerized, it is possible to obtain an
optical anisotropic body including a plurality of regions of which
alignment directions are different from each other.
[0320] In addition, even when the alignment of the polymerizable
liquid crystal composition in an unpolymerized state is regulated
in advance over the electric field, the magnetic field, the
temperature, or the like at the time of polymerizing only the
specific portion by the ultraviolet irradiation using the mask, and
the polymerizable liquid crystal composition is polymerized by
being irradiated with light from the mask while maintaining the
state, it is possible to obtain an optical anisotropic body
including a plurality of regions of which alignment directions are
different from each other.
[0321] In order to stabilize solvent resistance and heat resistance
of the obtained optical anisotropic body, it is possible to perform
a heat-aging treatment with respect to the optical anisotropic
body. In this case, it is preferable that heating be performed at a
temperature higher than or equal to a glass transition point of the
polymerizable liquid crystal composition film. In general, the
heating temperature is preferably 50.degree. C. to 300.degree. C.,
more preferably 80.degree. C. to 240.degree. C., and particularly
preferably 100.degree. C. to 220.degree. C.
[0322] The optical anisotropic body obtained by the steps described
above can be used as a single optical anisotropic body by peeling
off the optical anisotropic body layer from the substrate, and can
be used as an optical anisotropic body in a state where the optical
anisotropic body layer is not peeled off from the substrate. In
particular, it is difficult for the optical anisotropic body to
contaminate other members, and thus, the optical anisotropic body
is useful at the time of being used as a laminated substrate or
being used by being bonded to other substrates.
[0323] According to the photo-alignment method of the present
invention, the photo-alignment material containing the
photo-responsive substance having a threshold value of responding
light intensity is irradiated with light having light intensity of
greater than or equal to the threshold value, and the
photo-responsive substance contained in the photo-alignment
material is aligned. Accordingly, the photo-responsive substance is
aligned to be parallel to the vibration direction of the light, and
thus, it is possible to easily control the tilt angle of the
alignment film.
EXAMPLES
[0324] Hereinafter, the present invention will be further described
in detail with reference to examples, but the present invention is
not limited to the examples.
Example 1
[0325] A tetrahydrofuran (THF) solution containing 5 mass % of a
photo-responsive substance denoted by General Formula (III) shown
below (oligothiophene TR5, manufactured by Merck KGaA) (a
photo-alignment material (a)) was prepared.
##STR00081##
[0326] Next, one surface of a glass substrate attached with an ITO
electrode was coated with the THF solution by spin coating, and
then vacuum drying was performed at 40.degree. C.
[0327] Next, the glass substrate coated with the photo-alignment
material (a) was irradiated with argon ion laser light (a
wavelength of 488 nm) from a direction perpendicular to the one
surface of the glass substrate, and thus, a glass substrate (A)
coated with the photo-alignment material (a) which had been
subjected to light irradiation was obtained. In the irradiation of
the argon ion laser light, the light intensity was 5 W/cm.sup.2,
and the irradiation time was 60 seconds.
[0328] Next, a liquid crystal cell was prepared by using two glass
substrates (A), and by using the photo-alignment material (a) which
had been subjected to the light irradiation as an alignment film.
The two glass substrates (A) were bonded such that the surface
coated with the photo-alignment material (a) which had been
subjected to the light irradiation was arranged on the inner side
and an interval between the two glass substrates (A) was 5 .mu.m,
and thus, a glass cell was prepared.
[0329] Next, the cell was filled with 4-cyano-4'-pentyl biphenyl
denoted by General Formula (IV) shown below as a nematic liquid
crystal at a temperature just higher than a transparent point, and
cooling was performed to room temperature, and thus, a liquid
crystal cell (1) of Example 1 was obtained.
##STR00082##
[0330] The obtained liquid crystal cell (1) was observed with a
polarization microscope (Product Name: Olympus BX50, manufactured
by OLYMPUS CORPORATION), and thus, it was possible to confirm that
liquid crystal molecules were horizontally aligned in a direction
identical to a vibration surface of polarized light of the
irradiated argon ion laser light, and it was found that a dye which
had been subjected to light irradiation could be used as a material
for aligning the liquid crystal molecules.
[0331] The liquid crystal cell (1) was interposed between two
polarizing plates which were arranged in cross-nicol, and the
alignment direction of the liquid crystal molecules was disposed in
a direction of 45 degrees with respect to a polarization axis of
the polarizing plate, and thus, the light was transmitted.
[0332] In addition, when an electric field was applied to the ITO
electrodes of the two glass substrates (A) from the outside, the
alignment direction of the liquid crystal molecules was changed,
and thus, the light was not transmitted.
[0333] As described above, it was found that the liquid crystal
cell (1) of Example 1 functioned as a liquid crystal display
element using the photo-alignment material formed of the
photo-responsive substance.
Example 2
[0334] In Example 2, a glass cell was prepared by the same method
as that in Example 1 except that two substrates of a glass
substrate on which a comb-like electrode (an ITO transparent
electrode, Distance between Electrodes: 10 .mu.m, and Electrode
Width: 10 .mu.m) was disposed and a glass substrate on which an
electrode was not disposed were used instead of the glass substrate
attached with the ITO electrode, the substrate was coated with a
THF solution, and thus, a glass substrate (B1) on which the
comb-like electrode coated with the photo-alignment material (a)
which had been subjected to the light irradiation was disposed and
a glass substrate (B2) on which the electrode coated with the
photo-alignment material (a) which had been subjected to the light
irradiation was not disposed were obtained.
[0335] In addition, a liquid crystal composition (LC7) having a
composition denoted by General Formula (LC7) shown below,
##STR00083##
[0336] was prepared.
[0337] Next, the cell was filled with the liquid crystal
composition (LC7) at a temperature accurately higher than a
transparent point, and cooling was performed to room temperature,
and thus, a liquid crystal cell (2) of Example 2 was obtained.
[0338] The obtained liquid crystal cell (2) was observed with a
polarization microscope, and thus, it was possible to confirm that
liquid crystal molecules were horizontally aligned in a direction
identical to a vibration surface of polarized light of the
irradiated argon ion laser light, and it was found that a dye which
had been subjected to light irradiation could be used as a material
for aligning the liquid crystal molecules.
[0339] The liquid crystal cell (2) was interposed between two
polarizing plates which were arranged in cross-nicol, and the
alignment direction of the liquid crystal molecules was disposed in
a direction of 45 degrees with respect to a polarization axis of
the polarizing plate, and thus, the light was transmitted.
[0340] In addition, when an electric field was applied between the
ITO electrodes from the outside, the alignment direction of the
liquid crystal molecules was changed, and thus, the light was not
transmitted.
[0341] As described above, it was found that the liquid crystal
cell (2) of Example 2 functioned as a liquid crystal display
element using the photo-alignment material formed of the
photo-responsive substance.
Example 3
[0342] One surface of a glass substrate attached with an ITO
electrode was coated with a THF solution, and then vacuum drying
was performed at 40.degree. C., as with Example 1.
[0343] Next, the coated glass substrate was irradiated with argon
ion laser light (a wavelength of 488 nm) from a direction at an
oblique angle of 5 degrees with respect to a normal direction of
the one surface of the glass substrate, and thus, a glass substrate
(C) coated with the photo-alignment material (a) which had been
subjected to light irradiation was obtained. In the irradiation of
the argon ion laser light, the light intensity was 10 W/cm.sup.2,
and the irradiation time was 300 seconds.
[0344] Next, a liquid crystal cell was prepared by using two glass
substrates (C). The two glass substrates (C) were bonded such that
the surface coated with the photo-alignment material (a) which had
been subjected to the light irradiation was arranged on the inner
side, light irradiation directions were opposite to each other
(anti-parallel), and an interval between the two glass substrates
(C) was 5 .mu.m, and thus, a glass cell was prepared.
[0345] In addition, a liquid crystal composition (LC8) having a
composition denoted by General Formula (LC8) shown below,
##STR00084## ##STR00085##
[0346] was prepared.
[0347] Next, the cell was filled with the liquid crystal
composition (LC8) at a temperature accurately higher than a
transparent point, and cooling was performed to room temperature,
and thus, a liquid crystal cell (3) of Example 3 was obtained.
[0348] An oblique angle of the liquid crystal in the liquid crystal
cell was optically measured by a crystal rotation method, and thus,
the oblique angle was 88 degrees. Accordingly, it was found that
the liquid crystal cell (3) of Example 3 had a fine oblique angle
from the normal direction of the one surface of the glass substrate
which was necessary for a perpendicular alignment mode.
[0349] The liquid crystal cell was interposed between two
polarizing plates which were arranged in cross-nicol, and thus, a
dark field was obtained.
[0350] In addition, when an electric field was applied to the ITO
electrodes of the two glass substrates (C) from the outside, the
alignment direction of the liquid crystal molecules was changed,
and thus, the light was not transmitted.
[0351] As described above, it was found that the liquid crystal
cell (3) of Example 3 functioned as a liquid crystal display
element using the photo-alignment material formed of the
photo-responsive substance.
Synthesis Example 1
[0352] (Preparation of Polymerizable Liquid Crystal Composition
(LC-A))
[0353] 15 parts by mass of a compound denoted by General Formula
(V) shown below, and
##STR00086##
[0354] 15 parts by mass of a compound denoted by General Formula
(VI) shown below,
##STR00087##
[0355] were dissolved in 70 parts by mass of xylene, and then, 1.2
parts by mass of a photopolymerization initiator (Product Name:
Irgacure 907, manufactured by BASF SE) and 0.3 parts by mass of an
acrylic copolymer denoted by General Formula (VII) shown below,
##STR00088##
[0356] were added thereto, and thus, a solution was prepared.
[0357] The obtained solution was filtered with a membrane filter of
0.45 .mu.m, and thus, a polymerizable liquid crystal composition
(LC-A) was obtained.
Example 4
[0358] In Example 4, a glass substrate (D) coated with the
photo-alignment material (a) which had been subjected to the light
irradiation by the same method as that in Example 1 except that a
glass substrate on which the ITO electrode was not disposed was
used.
[0359] Next, an optical anisotropic body was manufactured by using
the glass substrate (D), and by using the photo-alignment material
(a) which had been subjected to the light irradiation as an
alignment film. The surface of the glass substrate (D) coated with
the photo-alignment material (a) which had been subjected to the
light irradiation was coated with a polymerizable liquid crystal
composition (LC-A) by spin coating, and drying was performed at
80.degree. C. for 1 minute.
[0360] Next, the polymerizable liquid crystal composition (LC-A)
applied onto the glass substrate (D) was irradiated with an
ultraviolet ray of 1 J/cm.sup.2 under a nitrogen atmosphere, and
the polymerizable liquid crystal composition (LC-A) was
polymerized, and thus, an optical anisotropic body (1) was
obtained.
[0361] The alignment direction of the obtained optical anisotropic
body (1) was observed with a polarization microscope, and thus, it
was confirmed that horizontal (homogeneous) alignment was obtained.
Thus, it was found that an optical anisotropic body could be
prepared in which homogeneous alignment of the liquid crystal was
fixed.
Synthesis Example 2
[0362] (Preparation of Polymerizable Liquid Crystal Composition
(LC-B))
[0363] 43 parts by mass of a compound denoted by General Formula
(V) described above, 43 parts by mass of a compound denoted by
General Formula (VI) described above, and 14 parts by mass of a
compound denoted by General Formula (VIII) shown below,
##STR00089##
[0364] were dissolved in 70 parts by mass of propylene glycol
monomethyl ether acetate, and then 2 parts by mass of a
photopolymerization initiator (Product Name: Irgacure 651,
manufactured by BASF SE) was added thereto, and thus, a solution
was prepared. The obtained solution was filtered with a membrane
filter of 0.45 .mu.m, and thus, a polymerizable liquid crystal
composition (LC-B) was obtained.
Example 5
[0365] In Example 5, a glass substrate (E) coated with the
photo-alignment material (a) which had been subjected to the light
irradiation was obtained by the same method as that in Example 3
except that a glass substrate on which an ITO electrode was not
disposed was used.
[0366] Next, an optical anisotropic body was prepared by using the
glass substrate (E), and by using the photo-alignment material (a)
which had been subjected to the light irradiation as an alignment
film. The surface of the glass substrate (E) coated with the
photo-alignment material (a) which had been subjected to the light
irradiation was coated with a polymerizable liquid crystal
composition (LC-B) by spin coating, and vacuum drying was performed
at 80.degree. C. for 1 minute.
[0367] Next, the polymerizable liquid crystal composition (LC-B)
applied onto the glass substrate was irradiated with an ultraviolet
ray of 1 J/cm.sup.2 under a nitrogen atmosphere, the polymerizable
liquid crystal composition (LC-B) was polymerized, and thus, an
optical anisotropic body (2) was obtained. The alignment direction
of the obtained optical anisotropic body (2) was observed with a
polarization microscope, and thus, it was confirmed that
perpendicular (homeotropic) alignment was obtained. Thus, it was
found that an optical anisotropic body could be prepared in which
homeotropic alignment of the liquid crystal was fixed.
Synthesis Example 3
[0368] (Preparation of Polymerizable Liquid Crystal Composition
(LC-C))
[0369] A mixture (MC-C) of 43 mol % of polymerizable liquid crystal
denoted by General Formula (IX) shown below,
##STR00090##
[0370] 37 mol % of a polymerizable liquid crystal denoted by
General Formula (X) shown below, and
##STR00091##
[0371] 20 mol % of a compound denoted by General Formula (XI) shown
below,
##STR00092##
[0372] was prepared.
[0373] Next, 99.4 mol % of the mixture (MC-C) and 0.1 mol % of a
dye denoted by General Formula (III) described above
(oligothiophene TR5, manufactured by Merck KGaA) (a
photo-responsive substance) were dissolved in THF, and then, 0.5
mol % of a photopolymerization initiator (Product Name: Irgacure
907, manufactured by BASF SE) was added and mixed, vacuum drying
was performed at 40.degree. C., and thus, a polymerizable liquid
crystal composition (LC-C) (a photo-alignment material (b))
containing the dye was obtained.
Example 6
[0374] A glass cell having a thickness of 10 .mu.m using a glass
substrate on which an ITO electrode was disposed and a glass
substrate on which the electrode was not disposed was filled with
the polymerizable liquid crystal composition (LC-C).
[0375] Next, the glass cell was irradiated with argon ion laser
light (a wavelength of 488 nm) from a direction perpendicular to
one surface of the glass cell such that the argon ion laser light
was even with respect to the entire glass cell and a vibration
surface of polarized light of the laser light was directed towards
a predetermined direction. In the irradiation of the argon ion
laser light, the light intensity was 5 W/cm.sup.2, and the
irradiation time was 60 seconds. The glass cell after the laser
light irradiation was observed using a polarization microscope, and
thus, it was confirmed that liquid crystal molecules were
horizontally aligned in a direction identical to the vibration
surface of the polarized light of the argon ion laser light.
[0376] Next, the entire glass cell was irradiated with an
ultraviolet ray of 1 J/cm.sup.2, and the polymerizable liquid
crystal composition (LC-C) was polymerized, and thus, the alignment
of the liquid crystal molecules was fixed.
[0377] After that, in the glass cell, the glass substrate on which
the electrode was not disposed was peeled off, and thus, a glass
substrate (F) was obtained in which the alignment of the
polymerizable liquid crystal molecules was fixed in a state of
being induced.
[0378] Next, a liquid crystal cell was prepared by using two glass
substrates (F), and by using a polymerizable liquid crystal
composition film fixed to the glass substrate as an alignment film.
The glass cell was prepared by the same method as that in Example 1
using the two glass substrates (F), the cell was filled with
4-cyano-4'-pentyl biphenyl denoted by General Formula (IV)
described above as a nematic liquid crystal at a temperature
accurately higher than a transparent point, and then, cooling was
performed to room temperature, and thus, a liquid crystal cell (4)
of Example 6 was obtained.
[0379] The obtained liquid crystal cell (4) was observed with a
polarization microscope, and thus, it was confirmed that the liquid
crystal molecules were horizontally aligned in a direction
identical to the vibration surface of the polarized light of the
irradiated argon ion laser light.
[0380] The liquid crystal cell (4) was interposed between two
polarizing plates which were arranged in cross-nicol, and the
alignment direction of the liquid crystal molecules was disposed in
a direction of 45 degrees with respect to a polarization axis of
the polarizing plate, and thus, the light was transmitted.
[0381] In addition, when an electric field was applied to the ITO
electrodes of the two glass substrates (F) from the outside, the
alignment direction of the liquid crystal molecules was changed,
and thus, the light was not transmitted.
[0382] As described above, it was found that the liquid crystal
cell (4) of Example 6 functioned as a liquid crystal display
element.
Example 7
[0383] In Example 7, a glass substrate (G) was obtained in which
the alignment of the polymerizable liquid crystal molecules was
fixed in a state of being induced by the same method as that in
Example 6 except that a glass substrate on which an ITO electrode
was not disposed was used.
[0384] Next, an optical anisotropic body was prepared by using the
glass substrate (G), and by using the fixed polymerizable liquid
crystal composition film as an alignment film. The surface of the
glass substrate (G) including the polymerizable liquid crystal
composition film was coated with the polymerizable liquid crystal
composition (LC-A) by spin coating, and then, drying was performed
at 80.degree. C. for 1 minute.
[0385] Next, the polymerizable liquid crystal composition (LC-A)
applied onto the glass substrate was irradiated with an ultraviolet
ray of 1 J/cm.sup.2 under a nitrogen atmosphere, and the
polymerizable liquid crystal composition (LC-A) was polymerized,
and thus, an optical anisotropic body (3) was obtained. The
alignment direction of the obtained optical anisotropic body (3)
was observed with a polarization microscope, and thus, it was
confirmed that horizontal (homogeneous) alignment was obtained.
Thus, it was found that an optical anisotropic body could be
prepared in which homogeneous alignment of the liquid crystal was
fixed.
INDUSTRIAL APPLICABILITY
[0386] The present invention can be used, for example, as a liquid
crystal display element, a retardation lens, and a manufacturing
method thereof
* * * * *