U.S. patent application number 13/557969 was filed with the patent office on 2016-08-25 for liquid crystal composition and liquid crystal display device.
This patent application is currently assigned to JNC PETROCHEMICAL CORPORATION. The applicant listed for this patent is Yukihiro FUJITA, Yoshimasa FURUSATO. Invention is credited to Yukihiro FUJITA, Yoshimasa FURUSATO.
Application Number | 20160244399 13/557969 |
Document ID | / |
Family ID | 48010487 |
Filed Date | 2016-08-25 |
United States Patent
Application |
20160244399 |
Kind Code |
A9 |
FUJITA; Yukihiro ; et
al. |
August 25, 2016 |
LIQUID CRYSTAL COMPOSITION AND LIQUID CRYSTAL DISPLAY DEVICE
Abstract
To provide a liquid crystal composition satisfying at least one
characteristic such as a high maximum temperature of a nematic
phase, a low minimum temperature thereof, a small viscosity, a
suitable optical anisotropy, a large negative dielectric
anisotropy, a large specific resistance, a high stability to
ultraviolet light and heat, or a liquid crystal composition having
a suitable balance regarding at least two characteristics, and an
AM device having a short response time, a large voltage holding
ratio, a large contrast ratio and a long service life; a liquid
crystal composition contains a specific compound having a
polymerizable group as a first component, and may contain a
specific compound having a large negative dielectric anisotropy and
a low minimum temperature as a second component or a specific
compound having a small viscosity or a large maximum temperature as
a third component, and a liquid crystal display device contains the
composition.
Inventors: |
FUJITA; Yukihiro;
(Ichihara-shi, JP) ; FURUSATO; Yoshimasa;
(Ichihara-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FUJITA; Yukihiro
FURUSATO; Yoshimasa |
Ichihara-shi
Ichihara-shi |
|
JP
JP |
|
|
Assignee: |
JNC PETROCHEMICAL
CORPORATION
Tokyo
JP
JNC CORPORATION
Tokyo
JP
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20130027654 A1 |
January 31, 2013 |
|
|
Family ID: |
48010487 |
Appl. No.: |
13/557969 |
Filed: |
July 25, 2012 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C09K 19/3068 20130101;
C09K 19/54 20130101; C09K 2019/3071 20130101; C09K 2019/123
20130101; C09K 2019/122 20130101; C07C 69/52 20130101; C09K 19/3402
20130101; C09K 2019/3043 20130101; C09K 2323/00 20200801; C09K
19/542 20130101; C09K 2019/3422 20130101; G02F 2001/13712 20130101;
C09K 19/3066 20130101; C09K 2019/548 20130101; C09K 2019/3078
20130101; C09K 2019/3425 20130101; C09K 19/0208 20130101; C09K
2019/0448 20130101; C09K 2019/3015 20130101; G02F 1/133365
20130101; C09K 19/44 20130101; Y10T 428/10 20150115; G02F
2001/13706 20130101 |
International
Class: |
C09K 19/56 20060101
C09K019/56; G02F 1/13 20060101 G02F001/13; G02F 1/1333 20060101
G02F001/1333; C09K 19/30 20060101 C09K019/30; C09K 19/54 20060101
C09K019/54; C09K 19/02 20060101 C09K019/02; C07C 69/52 20060101
C07C069/52; C09K 19/34 20060101 C09K019/34 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 27, 2011 |
JP |
2011-164298 |
Claims
1. A liquid crystal composition containing at least one compound
selected from the group of compounds represented by formula (1) as
a first component: ##STR00045## wherein R.sup.1, R.sup.2, R.sup.3,
R.sup.4, R.sup.5 and R.sup.6 are independently hydrogen, halogen,
hydroxy, --CH.sub.2OH, --SF.sub.5, --NO.sub.2, P-Sp- or alkyl
having 1 to 30 carbons, the alkyl is straight-chain, branched-chain
or cyclic, the alkyl may have an unsaturated bond, and in the
alkyl, at least one of non-adjacent --CH.sub.2-- may be replaced by
--O--, --S--, --CO--, --CO--O-- or --O--CO--, and in the groups, at
least one of hydrogen may be replaced by halogen; P is a
polymerizable group; Sp is a single bond or alkylene having 1 to 20
carbons, and in the alkylene, at least one of hydrogen may be
replaced by halogen or --CN, and in the groups, at least one of
non-adjacent --CH.sub.2-- may be independently replaced by --O--,
--S--, --NH--, --NR.sup.7--, --SiR.sup.7R.sup.8--, --CO--, --COO--,
--OCO--, --OCO--O--, --S--CO--, --CO--S--, --NR.sup.7--CO--O--,
--O--CO--NR.sup.7--, --NR.sup.7--CO--NR.sup.8--, --CH.dbd.CH-- or
--C.ident.C--; at least one of R.sup.1, R.sup.2, R.sup.3, R.sup.4,
R.sup.5 and R.sup.6 is P-Sp-; Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4,
Z.sup.5 and Z.sup.6 are independently a single bond, --O--, --S--,
--CO--, --CO--O--, --O--CO--, --O--CO--O-- or alkylene having 1 to
12 carbons; Z.sup.7 is independently --O--, --S--, --CO--,
--CO--O--, --O--CO--, --O--CO--O--, --OCH.sub.2--, --CH.sub.2O--,
--SCH.sub.2--, --CH.sub.2S--, --CF.sub.2O--, --OCF.sub.2--,
--CF.sub.2S--, --SCF.sub.2--, --(CR.sup.7R.sup.8).sub.m--,
--(CR.sup.7.dbd.CR.sup.8).sub.m--, --C.ident.C--,
--CR.sup.7.dbd.CR.sup.8--CO--O--, --O--CO--CR.sup.7.dbd.CR.sup.8--,
--CO--NR.sup.7--, --NR.sup.7--CO--, --CO--S--, --S--CO--,
--O--CO--CR.sup.7--CR.sup.8--O--, --O--CR.sup.7--CR.sup.8--CO--O--,
--CR.sup.7.dbd.CR.sup.8--CO--, --CO--CR.sup.7.dbd.CR.sup.8--,
--C(.dbd.CR.sup.7R.sup.8)--,
--O--CO--CR.sup.7R.sup.8--CR.sup.9R.sup.10--O--,
--O--CR.sup.7R.sup.8--CR.sup.9R.sup.10--CO--O-- or a single bond;
R.sup.7, R.sup.8, R.sup.9 and R.sup.10 independently hydrogen,
halogen or alkyl having 1 to 12 carbons, the alkyl is
straight-chain, branched-chain or cyclic, the alkyl may have an
unsaturated bond, and in the alkyl, at least one of non-adjacent
--CH.sub.2-- may be replaced by --O--, --S--, --CO--, --CO--O--, or
--O--CO--, and in the groups, at least one of hydrogen may be
replaced by halogen; m is 1, 2, 3 or 4; and n is an integer from 1
to 12.
2. The liquid crystal composition according to claim 1, wherein, in
formula (1), R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and
R.sup.6 are independently hydrogen, hydroxy, alkyl having 1 to 12
carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12
carbons, alkenyl having 2 to 12 carbons in which at least one of
hydrogen is replaced by fluorine, or a group selected from the
group of groups represented by formula (P-1) to formula (P-9); and
at least one of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and
R.sup.6 is a group selected from the group of groups represented by
formula (P-1) to formula (P-9): ##STR00046## wherein X.sup.2 and
X.sup.2 are independently hydrogen, --CH.sub.3, --C.sub.2H.sub.5 or
halogen; and X.sup.3 is hydrogen, --CH.sub.3, --C.sub.2H.sub.5,
halogen or --CF.sub.3.
3. The liquid crystal composition according to claim 1, wherein the
first component is at least one compound selected from the group of
compounds represented by formula (1-1) to formula (1-2):
##STR00047## wherein R.sup.1 and R.sup.2 are independently
hydrogen, halogen, hydroxy, --CH.sub.2OH, --SF.sub.5, --NO.sub.2,
P-- or alkyl having 1 to 12 carbons, the alkyl is straight-chain,
branched-chain or cyclic, the alkyl may have an unsaturated bond,
and in the alkyl, at least one of non-adjacent --CH.sub.2-- may be
replaced by --O--, --S--, --CO--, --CO--O-- or --O--CO--, and in
the groups, at least one of hydrogen may be replaced by halogen;
and P is acryloyloxy or methacryloyloxy.
4. The liquid crystal composition according to claim 1, wherein a
ratio of the first component is in the range of 0.05 part by weight
to 10 parts by weight based on 100 parts by weight of a liquid
crystal composition excluding the first component.
5. The liquid crystal composition according to claim 1, further
containing at least one compound selected from the group of
compounds represented by formula (2) as a second component:
##STR00048## wherein R.sup.11 and R.sup.12 are independently alkyl
having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl
having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which
at least one of hydrogen is replaced by fluorine; ring A and ring C
are independently 1,4-cyclohexylene, 1,4-phenylene, 1,4-phenylene
in which at least one of hydrogen is replaced by fluorine or
chlorine, or tetrahydropyran-2,5-diyl; ring B is
2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene,
2,3-difluoro-5-methyl-1,4-phenylene,
3,4,5-trifluoronaphthalene-2,6-diyl or
7,8-difluorochroman-2,6-diyl; Z.sup.8 and Z.sup.9 are independently
a single bond, ethylene, methyleneoxy or carbonyloxy; p is 1, 2 or
3; r is 0 or 1; and a sum of p and r is 3 or less.
6. The liquid crystal composition according to claim 5, wherein the
second component is at least one compound selected from the group
of compounds represented by formula (2-1) to formula (2-19):
##STR00049## ##STR00050## wherein R.sup.11 and R.sup.12 are
independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12
carbons or alkenyl having 2 to 12 carbons, or alkenyl having 2 to
12 carbons in which at least one of hydrogen is replaced by
fluorine.
7. The liquid crystal composition according to claim 5, wherein a
ratio of the second component is in the range of 10% by weight to
90% by weight based on the weight of a liquid crystal composition
excluding the first component.
8. The liquid crystal composition according to claim 1, further
containing at least one compound selected from the group of
compounds represented by formula (3) as a third component:
##STR00051## wherein R.sup.13 and R.sup.14 are independently alkyl
having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl
having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which
at least one of hydrogen was replaced by fluorine; ring D and ring
E are independently 1,4-cyclohexylene, 1,4-phenylene,
2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene or
2,5-difluoro-1,4-phenylene; Z.sup.10 is independently a single
bond, ethylene, methyleneoxy or carbonyloxy; and s is 1, 2 or
3.
9. The liquid crystal composition according to claim 5, further
containing at least one compound selected from the group of
compounds represented by formula (3) as a third component:
##STR00052## wherein R.sup.13 and R.sup.14 are independently alkyl
having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl
having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which
at least one of hydrogen is replaced by fluorine; ring D and ring E
are independently 1,4-cyclohexylene, 1,4-phenylene,
2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene or
2,5-difluoro-1,4-phenylene; Z.sup.10 is independently a single
bond, ethylene, methyleneoxy or carbonyloxy; and s is 1, 2 or
3.
10. The liquid crystal composition according to claim 8, wherein
the third component is at least one compound selected from the
group of compounds represented by formula (3-1) to formula (3-13):
##STR00053## ##STR00054## wherein R.sup.13 and R.sup.14 are
independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12
carbons or alkenyl having 2 to 12 carbons, or alkenyl having 2 to
12 carbons in which at least one of hydrogen is replaced by
fluorine.
11. The liquid crystal composition according to claim 9, wherein
the third component is at least one compound selected from the
group of compounds represented by formula (3-1) to formula (3-13):
##STR00055## ##STR00056## wherein R.sup.13 and R.sup.14 are
independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12
carbons or alkenyl having 2 to 12 carbons, or alkenyl having 2 to
12 carbons in which at least one of hydrogen is replaced by
fluorine.
12. The liquid crystal composition according to claim 8, wherein a
ratio of the third component is in the range of 10% by weight to
90% by weight based on the weight of a liquid crystal composition
excluding the first component.
13. The liquid crystal composition according to claim 9, wherein a
ratio of the third component is in the range of 10% by weight to
90% by weight based on the weight of a liquid crystal composition
excluding the first component.
14. The liquid crystal composition according to claim 1, further
containing a polymerization initiator.
15. The liquid crystal composition according to claim 1, further
containing a polymerization inhibitor.
16. The liquid crystal composition according to claim 1, wherein a
maximum temperature of a nematic phase is 70.degree. C. or higher,
an optical anisotropy (25.degree. C.) at a wavelength of 589
nanometers is 0.08 or more, and a dielectric anisotropy (25.degree.
C.) at a frequency of 1 kHz is -2 or less.
17. A liquid crystal display device, comprising two substrates
having an electrode layer on at least one of the substrates, and
arranging the liquid crystal composition according to claim 1
between the two substrates.
18. The liquid crystal display device according to claim 17,
wherein an operating mode in the liquid crystal display device is a
TN mode, a VA mode, an IPS mode or a PSA mode, and a driving mode
in the liquid crystal display device is an active matrix mode.
19. Use of the liquid crystal composition according to claim 1 in
the liquid crystal display device.
Description
[0001] This is a Non-Provisional application, which claims priority
to Japanese Patent Application No. 2011-162498, filed on Jul. 27,
2011; the contents of which are all herein incorporated by this
reference in their entireties. All publications, patents, patent
applications, databases and other references cited in this
application, all related applications referenced herein, and all
references cited therein, are incorporated by reference in their
entirety as if restated here in full and as if each individual
publication, patent, patent application, database or other
reference were specifically and individually indicated to be
incorporated by reference.
TECHNICAL FIELD
[0002] The invention relates to a liquid crystal composition
containing a polymerizable compound that is polymerized, for
example, by light or heat. The invention also relates to a liquid
crystal display device in which the liquid crystal composition is
sealed between substrates, and the polymerizable compound contained
in the liquid crystal composition is polymerized while adjusting a
voltage applied to a liquid crystal layer to immobilize alignment
of liquid crystals.
[0003] As the technical field, the invention relates to a liquid
crystal composition mainly suitable for use in an active matrix
(AM) device and so forth, and an AM device and so forth containing
the composition. More specifically, the invention relates to a
liquid crystal composition having a negative dielectric anisotropy,
and a device and so forth that contain the composition and have a
mode such as an in-plane switching (IPS) mode, a vertical alignment
(VA) mode or a polymer sustained alignment (PSA) mode. The VA mode
includes a multi-domain vertical alignment (MVA) mode and a
patterned vertical alignment (PVA) mode.
BACKGROUND ART
[0004] In a liquid crystal display device, a classification based
on an operating mode for liquid crystals includes a phase change
(PC) mode, a twisted nematic (TN) mode, a super twisted nematic
(STN) mode, an electrically controlled birefringence (ECB) mode, an
optically compensated bend (OCB) mode, an in-plane switching (IPS)
mode, a vertical alignment (VA) mode and a polymer sustained
alignment (PSA) mode. A classification based on a driving mode in
the device includes a passive matrix (PM) and an active matrix
(AM). The PM is further classified into static, multiplex and so
forth, and the AM is classified into a thin film transistor (TFT),
a metal insulator metal (MIM) and so forth. The TFT is further
classified into amorphous silicon and polycrystal silicon. The
latter is classified into a high temperature type and a low
temperature type according to a production process. A
classification based on a light source includes a reflective type
utilizing natural light, a transmissive type utilizing backlight
and a transflective type utilizing both the natural light and the
backlight.
[0005] The devices contain a liquid crystal composition having
suitable characteristics. The liquid crystal composition has a
nematic phase. General characteristics of the composition should be
improved to obtain an AM device having good general
characteristics. Table 1 below summarizes a relationship of the
general characteristics between two aspects. The general
characteristics of the composition will be further explained based
on a commercially available AM device. A temperature range of the
nematic phase relates to a temperature range in which the device
can be used. A preferred maximum temperature of the nematic phase
is approximately 70.degree. C. or higher and a preferred minimum
temperature of the nematic phase is approximately -10.degree. C. or
lower. Viscosity of the composition relates to a response time in
the device. A short response time is preferred for displaying
moving images on the device. Accordingly, a small viscosity in the
composition is preferred. A small viscosity at a low temperature is
further preferred.
TABLE-US-00001 TABLE 1 General Characteristics of Composition and
AM Device General Characteristics of General Characteristics No.
Composition of AM Device 1 Wide temperature range of a nematic Wide
usable temperature phase range 2 Small viscosity.sup.1) Short
response time 3 Suitable optical anisotropy Large contrast ratio 4
Large positive or negative dielectric Low threshold voltage and
anisotropy small electric power consumption Large contrast ratio 5
Large specific resistance Large voltage holding ratio and large
contrast ratio 6 High stability to ultraviolet light and Long
service life heat .sup.1)A liquid crystal composition can be
injected into a liquid crystal cell in a shorter period of
[0006] An optical anisotropy of the composition relates to a
contrast ratio in the device. A product (.DELTA.n.times.d) of the
optical anisotropy (.DELTA.n) of the composition and a cell gap (d)
in the device is designed so as to maximize the contrast ratio. A
suitable value of the product depends on the type of the operating
mode. The suitable value is in the range of approximately 0.30
micrometer to approximately 0.40 micrometer in a device having the
VA mode or the PSA mode, and in the range of approximately 0.20
micrometer to approximately 0.30 micrometer in a device having the
IPS mode. In the above case, a composition having a large optical
anisotropy is preferred for a device having a small cell gap. A
large absolute value of a dielectric anisotropy in the composition
contributes to a low threshold voltage, a small electric power
consumption and a large contrast ratio in the device. Accordingly,
the large absolute value of the dielectric anisotropy is preferred.
A large specific resistance in the composition contributes to a
large voltage holding ratio and a large contrast ratio in the
device. Accordingly, a composition having a large specific
resistance at room temperature and also at a high temperature in an
initial stage is preferred. A composition having a large specific
resistance at room temperature and also at a high temperature even
after the device has been used for a long period of time is
preferred. Stability of the composition to ultraviolet light and
heat relates to a service life of the liquid crystal display
device. In the case where the stability is high, the device has a
long service life. Such characteristics are preferred for an AM
device used in a liquid crystal projector, a liquid crystal
television and so forth.
[0007] A composition having a positive dielectric anisotropy is
used for an AM device having the TN mode. On the other hand, a
composition having a negative dielectric anisotropy is used for an
AM device having the VA mode. A composition having a positive or
negative dielectric anisotropy is used for an AM device having the
IPS mode. A composition having a positive or negative dielectric
anisotropy is used for an AM device having the PSA mode. Examples
of the liquid crystal composition having the negative dielectric
anisotropy are disclosed in Patent literatures No. 1 to No. 6 as
described below and so forth.
CITATION LIST
Patent Literature
[0008] Patent literature No. 1: JP 2004-131704 A. [0009] Patent
literature No. 2: JP 2009-102639 A. [0010] Patent literature No. 3:
WO 2009/030318 A. [0011] Patent literature No. 4: WO 2009/030322 A.
[0012] Patent literature No. 5: CN 101045866 A. [0013] Patent
literature No. 6: JP 2009-132718 A.
[0014] A desirable AM device has characteristics such as a wide
temperature range in which a device can be used, a short response
time, a large contrast ratio, a low threshold voltage, a large
voltage holding ratio and a long service life. A shorter response
time even by one millisecond is desirable. Thus, desirable
characteristics of a composition include a high maximum temperature
of a nematic phase, a low minimum temperature of the nematic phase,
a small viscosity, a suitable optical anisotropy, a large positive
or negative dielectric anisotropy, a large specific resistance, a
high stability to ultraviolet light and a high stability to
heat.
[0015] In a display having a PSA mode, a small amount
(approximately 0.3% by weight to approximately 1% by weight) of a
polymerizable compound (RM) is added to a liquid crystal
composition. After introduction into a liquid crystal display cell,
only the polymerizable compound is polymerized ordinarily under
irradiation with ultraviolet light in a state in which a voltage is
applied between electrodes to form a polymer structure within the
device. As the RM, a polymerizable mesogenic or liquid crystal
compound is known to be particularly suitable as a monomer to be
added to the liquid crystal composition.
SUMMARY OF INVENTION
[0016] The inventors of the invention have diligently continued to
conduct research for solving the problem, as a result, have found
that a specific liquid crystal composition satisfies desirable
characteristics and a liquid crystal display device containing the
composition exhibits an excellent performance, and thus has
completed the invention based on the knowledge.
[0017] The invention concerns a liquid crystal composition
containing at least one compound selected from the group of
specific compounds as a first component.
[0018] The invention also concerns a liquid crystal display device,
comprising two substrates having an electrode layer on at least one
of the substrates, and arranging the liquid crystal composition
between the two substrates.
[0019] The invention further concerns use of the liquid crystal
composition in the liquid crystal display device.
TECHNICAL PROBLEM
[0020] In general, the polymerizable mesogenic or liquid crystal
compound described above has a high capability of aligning liquid
crystal molecules. On the other hand, the compound has a poor
solubility in a liquid crystal composition, and crystallization
during transportation or in a liquid crystal display device is
concerned. Meanwhile, use of a polymerizable compound (RM) in a
larger amount has been required from a demand for improving
characteristics of the liquid crystal composition in recent
years.
[0021] One of the aims of the invention is to apply a non-mesogen
polymerizable compound that is believed to have a high solubility
in the liquid crystal composition as a monomer to be added to the
liquid crystal composition. Another aim of the invention is to
provide a liquid crystal composition satisfying at least one of
characteristics such as a high maximum temperature of a nematic
phase, a low minimum temperature of the nematic phase, a small
viscosity, a suitable optical anisotropy, a large negative
dielectric anisotropy, a large specific resistance, a high
stability to ultraviolet light and a high stability to heat. A
further aim is to provide a liquid crystal composition having a
suitable balance regarding at least two of the characteristics. A
still further aim is to provide a liquid crystal display device
containing such a composition. An additional aim is to provide a
composition having a suitable optical anisotropy to be a small
optical anisotropy or a large optical anisotropy, a large negative
dielectric anisotropy and a high stability to ultraviolet light,
and is to provide an AM device having a short response time, a
large voltage holding ratio, a large contrast ratio, a long service
life and so forth.
SOLUTION TO PROBLEM
[0022] The invention concerns a liquid crystal composition
containing at least one compound selected from the group of
compounds represented by formula (1) as a first component, and a
liquid crystal display device containing the composition:
##STR00001##
wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are
independently hydrogen, halogen, hydroxy, --CH.sub.2OH, --SF.sub.5,
--NO.sub.2, P-Sp- or alkyl having 1 to 30 carbons, the alkyl is
straight-chain, branched-chain or cyclic, the alkyl may have an
unsaturated bond, and in the alkyl, at least one of non-adjacent
--CH.sub.2-- may be replaced by --O--, --S--, --CO--, --CO--O-- or
--O--CO--, and in the groups, at least one of hydrogen may be
replaced by halogen; P is a polymerizable group; Sp is a single
bond or alkylene having 1 to 20 carbons, and in the alkylene, at
least one of hydrogen may be replaced by halogen or --C.ident.N,
and in the groups, at least one of non-adjacent --CH.sub.2-- may be
independently replaced by --O--, --S--, --NH--, --NR.sup.7--,
--SiR.sup.7R.sup.8--, --CO--, --COO--, --OCO--, --OCO--O--,
--S--CO--, --CO--S--, --NR.sup.7--CO--O--, --O--CO--NR.sup.7--,
--NR.sup.7--CO--NR.sup.8--, --CH.dbd.CH-- or --C.ident.C--; at
least one of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and
R.sup.6 is P-Sp-; Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5 and
Z.sup.6 are independently a single bond, --O--, --S--, --CO--,
--CO--O--, --O--CO--, --O--CO--O-- or alkylene having 1 to 12
carbons; Z.sup.7 is independently --O--, --S--, --CO--, --CO--O--,
--O--CO--, --O--CO--O--, --OCH.sub.2--, --CH.sub.2O--,
--SCH.sub.2--, --CH.sub.2S--, --CF.sub.2O--, --OCF.sub.2--,
--CF.sub.2S--, --SCF.sub.2--, --(CR.sup.7R.sup.8).sub.m--,
--(CR.sup.7.dbd.CR.sup.8).sub.m--, --C.ident.C--,
--CR.sup.7.dbd.CR.sup.8--CO--O--, --O--CO--CR.sup.7.dbd.CR.sup.8--,
--CO--NR.sup.7--, --NR.sup.7--CO--, --CO--S--, --S--CO--,
--O--CO--CR.sup.7--CR.sup.8--O--, --O--CR.sup.7--CR.sup.8--CO--O--,
--CR.sup.7.dbd.CR.sup.8--CO--, --CO--CR.sup.7.dbd.CR.sup.8--,
--C(.dbd.CR.sup.7R.sup.8)--,
--O--CO--CR.sup.7R.sup.8--CR.sup.9R.sup.10--O--,
--O--CR.sup.7R.sup.8--CR.sup.9R.sup.10--CO--O-- or a single bond;
R.sup.7, R.sup.8, R.sup.9 and R.sup.10 are independently hydrogen,
halogen or alkyl having 1 to 12 carbons, the alkyl is
straight-chain, branched-chain or cyclic, the alkyl may have an
unsaturated bond, and in the alkyl, at least one of non-adjacent
--CH.sub.2-- may be replaced by --O--, --S--, --CO--, --CO--O-- or
--O--CO--, and in the groups, at least one of hydrogen may be
replaced by halogen; m is 1, 2, 3 or 4; and n is an integer from 1
to 12.
ADVANTAGEOUS EFFECTS OF INVENTION
[0023] An advantage of the invention is a high solubility of a
polymerizable compound in a liquid crystal composition. Another
advantage of the invention is a liquid crystal composition
satisfying at least one of characteristics such as a high maximum
temperature of a nematic phase, a low minimum temperature of the
nematic phase, a small viscosity, a suitable optical anisotropy, a
large negative dielectric anisotropy, a large specific resistance,
a high stability to ultraviolet light and a high stability to heat.
One aspect of the invention is a liquid crystal composition having
a suitable balance regarding at least two of the characteristics.
Another aspect is a liquid crystal display device containing such a
composition. A further aspect is a polymerizable compound having a
high solubility, a composition having a suitable optical
anisotropy, a large negative dielectric anisotropy, a high
stability to ultraviolet light and so forth, and an AM device
having a short response time, a large voltage holding ratio, a
large contrast ratio, a long service life and so forth.
DESCRIPTION OF EMBODIMENTS
[0024] Usage of terms in the specification and claims is as
described below. A liquid crystal composition or a liquid crystal
display device of the invention may be abbreviated as "composition"
or "device," respectively. The liquid crystal display device is a
generic term for a liquid crystal display panel and a liquid
crystal display module. "Liquid crystal compound" means a compound
having a liquid crystal phase such as a nematic phase or a smectic
phase, or a compound having no liquid crystal phase but being
useful as a component of the composition. The useful compound has a
six-membered ring such as 1,4-cyclohexylene and 1,4-phenylene, and
a rod like molecular structure. An optically active compound and a
polymerizable compound may occasionally be added to the
composition. Even in the case where the compounds are liquid
crystalline, the compounds are classified as an additive herein. At
least one compound selected from the group of compounds represented
by formula (1) may be abbreviated as "compound (1)." "Compound (1)"
means one compound or two or more compounds represented by formula
(1). A same rule applies to any other compound represented by any
other formula. "At least one" to be "replaced" indicates any of not
only positions but also numbers.
[0025] A higher limit of a temperature range of the nematic phase
may be abbreviated as "maximum temperature." A lower limit of the
temperature range of the nematic phase may be abbreviated as
"minimum temperature." An expression "having a specific resistance"
means that the composition has a large specific resistance at room
temperature and also at a temperature close to the maximum
temperature of the nematic phase in an initial stage, and that the
composition has a large specific resistance at room temperature and
also at a temperature close to the maximum temperature of the
nematic phase even after the device has been used for a long period
of time. An expression "having a large voltage holding ratio" means
that the device has a large voltage holding ratio at room
temperature and also at a high temperature in an initial stage, and
that the device has a large voltage holding ratio at room
temperature and also at a temperature close to the maximum
temperature of the nematic phase even after the device has been
used for a long period of time. When characteristics such as an
optical anisotropy are explained, values obtained according to the
measuring methods described in Examples will be used. A first
component includes one compound or two or more compounds. "Ratio of
the first component" is expressed in terms of a weight ratio (part
by weight) of the first component based on 100 parts by weight of a
liquid crystal composition excluding the first component. "Ratio of
a second component" is expressed in terms of weight percent (% by
weight) of the second component based on the weight of the liquid
crystal composition excluding the first component. "Ratio of a
third component" is expressed in a manner similar to "ratio of the
second component." A ratio of the additive mixed with the
composition is expressed in terms of weight percent (% by weight)
or weight parts per million (ppm) based on the total weight of the
liquid crystal composition.
[0026] A symbol R.sup.11 is used for a plurality of compounds in
chemical formulas of component compounds. A group to be selected by
R.sup.11 maybe identical or different in two of arbitrary compounds
among the plurality of compounds. In one case, for example,
R.sup.11 of compound (2-1) is ethyl and R.sup.11 of compound (2-2)
is ethyl. In another case, R.sup.11 of compound (2-1) is ethyl and
R.sup.11 of compound (2-2) is propyl. A same rule applies to a
symbol R.sup.1, X.sup.1 or the like. The invention includes the
items described below.
[0027] Item 1. A liquid crystal composition containing at least one
compound selected from the group of compounds represented by
formula (1) as a first component:
##STR00002##
wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are
independently hydrogen, halogen, hydroxy, --CH.sub.2OH, --SF.sub.5,
--NO.sub.2, P-Sp- or alkyl having 1 to 30 carbons, the alkyl is
straight-chain, branched-chain or cyclic, the alkyl may have an
unsaturated bond, and in the alkyl, at least one of non-adjacent
--CH.sub.2-- may be replaced by --O--, --S--, --CO--, --CO--O-- or
--O--CO--, and in the groups, at least one of hydrogen may be
replaced by halogen; P is a polymerizable group; Sp is a single
bond or alkylene having 1 to 20 carbons, and in the alkylene, at
least one of hydrogen may be replaced by halogen or --CN, and in
the groups, at least one of non-adjacent --CH.sub.2-- may be
independently replaced by --O--, --S--, --NH--, --NR.sup.7--,
--SiR.sup.7R.sup.8--, --CO--, --COO--, --OCO--, --OCO--O--,
--S--CO--, --CO--S--, --NR.sup.7--CO--O--, --O--CO--NR.sup.7--,
--NR.sup.7--CO--NR.sup.8--, --CH.dbd.CH-- or --C.ident.C--; at
least one of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and
R.sup.6 is P-Sp-; Z.sup.2, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5 and
Z.sup.6 are independently a single bond, --O--, --S--, --CO--,
--CO--O--, --O--CO--, --O--CO--O-- or alkylene having 1 to 12
carbons; Z.sup.7 is independently --O--, --S--, --CO--, --CO--O--,
--O--CO--, --O--CO--O--, --OCH.sub.2--, --CH.sub.2O--,
--SCH.sub.2--, --CH.sub.2S--, --CF.sub.2O--, --OCF.sub.2--,
--CF.sub.2S--, --SCF.sub.2--, --(CR.sup.7R.sup.8).sub.m--,
--(CR.sup.7.dbd.CR.sup.8).sub.m--, --C.ident.C--,
--CR.sup.7.dbd.CR.sup.8--CO--O--, --O--CO--CR.sup.7.dbd.CR.sup.8--,
--CO--NR.sup.7--, --NR.sup.7--CO--, --CO--S--, --S--CO--,
--O--CO--CR.sup.7--CR.sup.8--O--, --O--CR.sup.7--CR.sup.8--CO--O--,
--CR.sup.7.dbd.CR.sup.8--CO--, --CO--CR.sup.7.dbd.CR.sup.8--,
--C(.dbd.CR.sup.7R.sup.8)--,
--O--CO--CR.sup.7R.sup.8--CR.sup.9R.sup.10--O--,
--O--CR.sup.7R.sup.8--CR.sup.9R.sup.10--CO--O or a single bond;
R.sup.7, R.sup.8, R.sup.9 and R.sup.10 are independently hydrogen,
halogen or alkyl having 1 to 12 carbons, the alkyl is
straight-chain, branched-chain or cyclic, the alkyl may have an
unsaturated bond, and in the alkyl, at least one of non-adjacent
--CH.sub.2-- may be replaced by --O--, --S--, --CO--, --CO--O-- or
--O--CO--, and in the groups, at least one of hydrogen may be
replaced by halogen; m is 1, 2, 3 or 4; and n is an integer from 1
to 12.
[0028] Item 2. The liquid crystal composition according to R.sup.2,
R.sup.3, R.sup.4, item 1, wherein, in formula (1), R.sup.1,
R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are independently
hydrogen, hydroxy, alkyl having 1 to 12 carbons, alkoxy having 1 to
12 carbons, alkenyl having 2 to 12 carbons, alkenyl having 2 to 12
carbons in which at least one of hydrogen is replaced by fluorine,
or a group selected from the group of groups represented by formula
(P-1) to formula (P-9); and at least one of R.sup.1, R.sup.2,
R.sup.3, R.sup.4, R.sup.5 and R.sup.6 is a group selected from the
group of groups represented by formula (P-1) to formula (P-9):
##STR00003##
wherein X.sup.2 and X.sup.2 are independently hydrogen, --CH.sub.3,
--C.sub.2H.sub.5 or halogen; and X.sup.3 is hydrogen, --CH.sub.3,
--C.sub.2H.sub.5, halogen or --CF.sub.3.
[0029] Item 3. The liquid crystal composition according to item 1,
wherein the first component is at least one compound selected from
the group of compounds represented by formula (1-1) to formula
(1-2):
##STR00004##
wherein R.sup.1 and R.sup.2 are independently hydrogen, halogen,
hydroxy, --CH.sub.2OH, --SF.sub.5, --NO.sub.2, P-- or alkyl having
1 to 12 carbons, the alkyl is straight-chain, branched-chain or
cyclic, the alkyl may have an unsaturated bond, and in the alkyl,
at least one of non-adjacent --CH.sub.2-- may be replaced by --O--,
--S--, --CO--, --CO--O-- or --O--CO--, and in the groups, at least
one of hydrogen may be replaced by halogen; and P is acryloyloxy or
methacryloyloxy.
[0030] Item 4. The liquid crystal composition according to any one
of items 1 to 3, wherein a ratio of the first component is in the
range of 0.05 part by weight to 10 parts by weight based on 100
parts by weight of a liquid crystal composition excluding the first
component.
[0031] Item 5. The liquid crystal composition according to any one
of items 1 to 4, further containing at least one compound selected
from the group of compounds represented by formula (2) as a second
component:
##STR00005##
wherein R.sup.11 and R.sup.12 are independently alkyl having 1 to
12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12
carbons, or alkenyl having 2 to 12 carbons in which at least one of
hydrogen is replaced by fluorine; ring A and ring C are
independently 1,4-cyclohexylene, 1,4-phenylene, 1,4-phenylene in
which at least one of hydrogen is replaced by fluorine or chlorine,
or tetrahydropyran-2,5-diyl; ring B is 2,3-difluoro-1,4-phenylene,
2-chloro-3-fluoro-1,4-phenylene,
2,3-difluoro-5-methyl-1,4-phenylene,
3,4,5-trifluoronaphthalene-2,6-diyl or
7,8-difluorochroman-2,6-diyl; Z.sup.8 and Z.sup.9 are independently
a single bond, ethylene, methyleneoxy or carbonyloxy; p is 1, 2 or
3; r is 0 or 1; and a sum of p and r is 3 or less.
[0032] Item 6. The liquid crystal composition according to item 5,
wherein the second component is at least one compound selected from
the group of compounds represented by formula (2-1) to formula
(2-19):
##STR00006## ##STR00007##
wherein R.sup.11 and R.sup.12 are independently alkyl having 1 to
12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12
carbons, or alkenyl having 2 to 12 carbons in which at least one of
hydrogen is replaced by fluorine.
[0033] Item 7. The liquid crystal composition according to item 5,
wherein the second component is at least one compound selected from
the group of compounds represented by formula (2-1) according to
item 6.
[0034] Item 8. The liquid crystal composition according to item 5,
wherein the second component is a mixture of at least one compound
selected from the group of compounds represented by formula (2-1)
and at least one compound selected from the group of compounds
represented by formula (2-6) according to item 6.
[0035] Item 9. The liquid crystal composition according to item 5,
wherein the second component is a mixture of at least one compound
selected from the group of compounds represented by formula (2-1)
and at least one compound selected from the group of compounds
represented by formula (2-13) according to item 6.
[0036] Item 10. The liquid crystal composition according to item 5,
wherein the second component is a mixture of at least one compound
selected from the group of compounds represented by formula (2-4)
and at least one compound selected from the group of compounds
represented by formula (2-8) according to item 6.
[0037] Item 11. The liquid crystal composition according to any one
of items 5 to 10, wherein a ratio of the second component is in the
range of 10% by weight to 90% by weight based on the weight of a
liquid crystal composition excluding the first component.
[0038] Item 12. The liquid crystal composition according to any one
of items 1 to 11, further containing at least one compound selected
from the group of compounds represented by formula (3) as a third
component:
##STR00008##
wherein R.sup.13 and R.sup.14 are independently alkyl having 1 to
12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12
carbons, or alkenyl having 2 to 12 carbons in which at least one of
hydrogen is replaced by fluorine; ring D and ring E are
independently 1,4-cyclohexylene, 1,4-phenylene,
2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene or
2,5-difluoro-1,4-phenylene; Z.sup.10 is independently a single
bond, ethylene, methyleneoxy or carbonyloxy; and s is 1, 2 or
3.
[0039] Item 13. The liquid crystal composition according to item
12, wherein the third component is at least one compound selected
from the group of compounds represented by formula (3-1) to formula
(3-13):
##STR00009## ##STR00010##
wherein R.sup.13 and R.sup.14 are independently alkyl having 1 to
12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12
carbons, or alkenyl having 2 to 12 carbons in which at least one of
hydrogen is replaced by fluorine.
[0040] Item 14. The liquid crystal composition according to item
12, wherein the third component is at least one compound selected
from the group of compounds represented by formula (3-1) according
to item 13.
[0041] Item 15. The liquid crystal composition according to item
12, wherein the third component is a mixture of at least one
compound selected from the group of compounds represented by
formula (3-1) and at least one compound selected from the group of
compounds represented by formula (3-5) according to item 13.
[0042] Item 16. The liquid crystal composition according to item
12, wherein the third component is a mixture of at least one
compound selected from the group of compounds represented by
formula (3-1) and at least one compound selected from the group of
compounds represented by formula (3-7) according to item 13.
[0043] Item 17. The liquid crystal composition according to item
12, wherein the third component is a mixture of at least one
compound selected from the group of compounds represented by
formula (3-1), at least one compound selected from the group of
compounds represented by formula (3-5) and at least one compound
selected from the group of compounds represented by formula (3-7)
according to item 13.
[0044] Item 18. The liquid crystal composition according to any one
of items 12 to 17, wherein a ratio of the third component is in the
range of 10% by weight to 90% by weight based on the weight of a
liquid crystal composition excluding the first component.
[0045] Item 19. The liquid crystal composition according to any one
of items 1 to 18, further containing a polymerization
initiator.
[0046] Item 20. The liquid crystal composition according to any one
of items 1 to 19, further containing a polymerization
inhibitor.
[0047] Item 21. The liquid crystal composition according to any one
of items 1 to 20, wherein a maximum temperature of a nematic phase
is 70.degree. C. or higher, an optical anisotropy (25.degree. C.)
at a wavelength of 589 nanometers is 0.08 or more, and a dielectric
anisotropy (25.degree. C.) at a frequency of 1 kHz is -2 or
less.
[0048] Item 22. A liquid crystal display device, comprising two
substrates having an electrode layer on at least one of the
substrates, and arranging the liquid crystal composition according
to any one of items 1 to 21 between the two substrates.
[0049] Item 23. The liquid crystal display device according to item
22, wherein an operating mode in the liquid crystal display device
is a TN mode, a VA mode, an IPS mode or a PSA mode, and a driving
mode in the liquid crystal display device is an active matrix
mode.
[0050] Item 24. Use of the liquid crystal composition according to
any one of items 1 to 21 in the liquid crystal display device.
[0051] The invention further includes the following items: (1) the
composition, further containing the optically active compound; (2)
the composition, further containing the additive such as an
antioxidant, an ultraviolet light absorber or an antifoaming agent;
(3) an AM device containing the composition; (4) a device
containing the composition, and having a TN, ECB, OCB, IPS, VA or
PSA mode; (5) a transmissive device, containing the composition;
(6) use of the composition as the composition having the nematic
phase; and (7) use as an optically active composition by adding the
optically active compound to the composition.
[0052] The composition of the invention will be explained in the
following order. First, a constitution of the component compounds
in the composition will be explained. Second, main characteristics
of the component compounds and main effects of the compounds on the
composition will be explained. Third, a combination of components
in the composition, a preferred ratio of the components and the
basis thereof will be explained. Fourth, a preferred embodiment of
the component compounds will be explained. Fifth, specific examples
of the component compounds will be shown. Sixth, the additive that
may be mixed with the composition will be explained. Seventh,
methods for synthesizing the component compounds will be explained.
Last, an application of the composition will be explained.
[0053] First, the constitution of the component compounds in the
composition will be explained. The composition of the invention is
classified into composition A and composition B. Composition A may
further contain any other liquid crystal compound, the additive and
an impurity, in addition to the liquid crystal compound selected
from compound (1), compound (2) and compound (3). "Any other liquid
crystal compound" means a liquid crystal compound different from
compound (1), compound (2) and compound (3). Such a compound is
mixed with the composition for the purpose of further adjusting the
characteristics. Of any other liquid crystal compounds, a ratio of
a cyano compound is preferably as small as possible in view of
stability to heat or ultraviolet light. A further preferred ratio
of the cyano compound is 0% by weight. The additive includes the
optically active compound, the antioxidant, the ultraviolet light
absorber, a dye, the antifoaming agent and the polymerization
initiator. The impurity includes a compound mixed in a process such
as preparation of the component compounds. Even in the case where
the compound is liquid crystalline, the compound is classified as
the impurity herein.
[0054] Composition B consists essentially of compound (1), compound
(2) and compound (3). A term "essentially" means that the
composition may also contain the additive and the impurity, but
does not contain any liquid crystal compound different from the
compounds. Composition B has a smaller number of components than
composition A has. Composition B is preferred to composition A in
view of cost reduction. Composition A is preferred to composition B
in view of possibility of further adjusting physical properties by
mixing any other liquid crystal compound.
[0055] Second, the main characteristics of the component compounds
and the main effects of the compounds on the characteristics of the
composition will be explained. The main characteristics of the
component compounds are summarized in Table 2 on the basis of
advantageous effects of the invention. In Table 2, a symbol L
stands for "large" or "high," a symbol M stands for "medium," and a
symbol S stands for "small" or "low." The symbols L, M and S
represent a classification based on a qualitative comparison among
the component compounds, and 0 (zero) means "a value is close to
zero."
TABLE-US-00002 TABLE 2 Characteristics of Compounds Compounds
Compound (2) Compound (3) Maximum Temperature S to L S to L
Viscosity M to L S to M Optical Anisotropy M to L S to L Dielectric
Anisotropy M to L.sup.1) 0 Specific Resistance L L .sup.1)A value
of the dielectric anisotropy is negative, and the symbol shows
magnitude of an absolute value.
[0056] Upon mixing the component compounds with the composition,
the main effects of the component compounds on the characteristics
of the composition are as described below. Compound (2) increases
the absolute value of the dielectric anisotropy, and decreases the
minimum temperature. Compound (3) decreases the viscosity, or
increases the maximum temperature.
[0057] Third, the combination of components in the composition, the
preferred ratio of the components and the basis thereof will be
explained. The combination of the components in the composition
includes a combination of the first component and the second
component, and a combination of the first component, the second
component and the third component.
[0058] A preferred ratio of the first compound is approximately
0.05 part by weight or more for aligning liquid crystal molecules,
and approximately 10 parts by weight or less for avoiding a poor
display, based on 100 parts by weight of the liquid crystal
composition excluding the first component. A further preferred
ratio is in the range of approximately 0.1 part by weight to
approximately 2 parts by weight.
[0059] A preferred ratio of the second component is approximately
10% by weight or more for increasing the absolute value of the
dielectric anisotropy, and approximately 90% by weight or less for
decreasing the minimum temperature, based on the liquid crystal
composition excluding the first component. A further preferred
ratio is in the range of approximately 20% by weight to
approximately 80% by weight. A particularly preferred ratio is in
the range of approximately 30% by weight to approximately 70% by
weight.
[0060] A preferred ratio of the third component is approximately
10% by weight or more for decreasing the viscosity or increasing
the maximum temperature, and approximately 90% or less for
increasing the absolute value of the dielectric anisotropy, based
on the liquid crystal composition excluding the first component. A
further preferred ratio is in the range of approximately 20% by
weight to approximately 80% by weight. A particularly preferred
ratio is in the range of approximately 30% by weight to
approximately 70% by weight.
[0061] Fourth, the preferred embodiment of the component compounds
will be explained. R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and
R.sup.6 are independently hydrogen, halogen, hydroxy, --CH.sub.2OH,
--SF.sub.5, --NO.sub.2, P-Sp- or alkyl having 1 to 30 carbons, the
alkyl is straight-chain, branched-chain or cyclic, the alkyl may
have an unsaturated bond, and in the alkyl, at least one of
non-adjacent --CH.sub.2-- may be replaced by --O--, --S--, --CO--,
--CO--O-- or --O--CO--, and in the groups, at least one of hydrogen
may be replaced by halogen, and at least one of R.sup.1, R.sup.2,
R.sup.3, R.sup.4, R.sup.5 and R.sup.6 is P-Sp-. Two of arbitrary
R.sup.4 or R.sup.6 when n is an integer from 2 to 12 may be
identical or different. Preferred R.sup.1, R.sup.2, R.sup.3,
R.sup.4, R.sup.5 or R.sup.6 is hydrogen, halogen, hydroxy,
--CH.sub.2OH, P-Sp- or alkyl having 1 to 10 carbons, the alkyl is
straight-chain, branched-chain or cyclic, and the alkyl may have an
unsaturated bond. Further preferred R.sup.1, R.sup.2, R.sup.3,
R.sup.4, R.sup.5 or R.sup.6 is hydrogen, P-Sp- or alkyl having 1 to
10 carbons for increasing the stability to light or heat, the alkyl
is straight-chain, branched-chain or cyclic, and the alkyl may have
an unsaturated bond. Moreover, three to five of R.sup.1, R.sup.2,
R.sup.3, R.sup.4, R.sup.5 and R.sup.6 is preferably P-Sp-. P is a
polymerizable group. Preferred P is at least one group selected
from the group of groups represented by formula (P-1) to formula
(P-9). Further preferred P is acryloyloxy or methacryloyloxy for
increasing photoreactivity. Sp is a single bond or alkylene having
1 to 20 carbons, and in the alkylene, at least one of hydrogen may
be replaced by halogen or --CN, and in the groups, at least one of
non-adjacent --CH.sub.2-- may be independently replaced by --O--,
--S--, --NH--, --NR.sup.7--, --SiR.sup.7R.sup.8--, --CO--, --COO--,
--OCO--, --OCO--O--, --S--CO--, --CO--S--, --NR.sup.7--CO--O--,
--O--CO--NR.sup.7--, --NR.sup.7--CO--NR.sup.8--, --CH.dbd.CH-- or
--C.ident.C--. Preferred Sp is well known to a person skilled in
the art, and is straight-chain or branched-chain alkylene having 1
to 8 carbons. Further preferred Sp is a single bond.
[0062] R.sup.7, R.sup.8, R.sup.9 and R.sup.10 are independently
hydrogen, halogen or alkyl having 1 to 12 carbons, the alkyl is
straight-chain, branched-chain or cyclic, the alkyl may have an
unsaturated bond, and in the alkyl, at least one of non-adjacent
--CH.sub.2-- may be replaced by --O--, --S--, --CO--, --CO--O-- or
--O--CO--, and in the groups, at least one of hydrogen may be
replaced by halogen. Preferred R.sup.7, R.sup.8, R.sup.9 or
R.sup.18 is hydrogen, halogen or alkyl having 1 to 3 carbons for
increasing the photoreactivity, the alkyl is straight-chain,
branched-chain or cyclic, and the alkyl may have an unsaturated
bond.
[0063] R.sup.11, R.sup.12, R.sup.13 and R.sup.14 are independently
alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or
alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons
in which at least one of hydrogen is replaced by fluorine.
Preferred R.sup.11 or R.sup.12 is alkyl having 1 to 12 carbons for
increasing the stability to ultraviolet light or heat, and alkoxy
having 1 to 12 carbons for increasing the absolute value of the
dielectric anisotropy. Preferred R.sup.18 or R.sup.14 is alkyl
having 1 to 12 carbons for increasing the stability to ultraviolet
light or heat, and alkenyl having 2 to 12 carbons for decreasing
the minimum temperature.
[0064] In the first component, preferred alkyl is methyl, ethyl,
propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, isopentyl,
hexyl, isohexyl, heptyl, isoheptyl, octyl, isooctyl, cyclopropyl,
cyclobutyl, 2-methylcyclopropyl, cyclopropylmethyl, cyclopentyl,
cyclohexyl, trifluoromethyl, perfluoro-n-butyl,
2,2,2-trifluoroethyl, perfluorohexyl, vinyl, 1-propenyl,
2-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl,
1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-methyl-2-butenyl,
1-methyl-3-butenyl, 1,1-dimethyl-2-propenyl, 3-methyl-2-butenyl,
1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl,
2-methyl-1-pentenyl, 3-methyl-1-pentenyl, 4-methyl-1-pentenyl,
2-methyl-2-pentenyl, 3-methyl-2-pentenyl, 2-ethyl-1-butenyl,
3,3-dimethyl-1-butenyl, ethynyl, 1-propynyl, 2-propynyl, 1-butynyl,
2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl,
4-pentynyl, 4-methyl-1-pentenyl, 1-hexynyl, phenyl, naphthyl,
anthryl, benzyl, methyloxy, ethyloxy, propyloxy, isopropyloxy,
butyloxy, isobutyloxy, s-butyloxy, t-butyloxy, pentyloxy,
isopentyloxy, hexyloxy, heptyloxy, cyclopropyloxy, cyclobutyloxy,
2-methylcyclopropyloxy, cyclopropylmethyloxy, cyclopenthyloxy or
cyclohexyloxy. Further preferred alkyl is methyl, ethyl, propyl,
isopropyl, trifluoromethyl, 2,2,2-trifluoroethyl, vinyl,
1-propenyl, 2-propenyl, isopropenyl, ethynyl, 1-propynyl,
2-propynyl, methyloxy, ethyloxy, propyloxy or isopropyloxy for
increasing the photoreactivity.
[0065] In the second component and the third component, preferred
alkyl is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or
octyl. Further preferred alkyl is ethyl, propyl, butyl, pentyl or
heptyl for decreasing the viscosity.
[0066] Alkylene of the first component is straight-chain or
branched-chain. Preferred straight-chain alkylene is ethylene,
propylene, butylene, pentylene, hexylene, heptylene, octylene,
nonylene, decylene, undecylene, dodecylene, ethyleneoxyethylene,
methyleneoxybutylene, ethylenethioethylene, ethenylene, propenylene
or butenylene. Preferred branched-chain alkylene is
1-methylethylene or 1-methylpropylene.
[0067] Preferred alkoxy is methoxy, ethoxy, propoxy, butoxy,
pentyloxy, hexyloxy or heptyloxy. Further preferred alkoxy is
methoxy or ethoxy for decreasing the viscosity.
[0068] Preferred alkenyl is vinyl, 1-propenyl, 2-propenyl,
1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl,
3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl
or 5-hexenyl. Further preferred alkenyl is vinyl, 1-propenyl,
3-butenyl or 3-pentenyl for decreasing the viscosity. A preferred
configuration of --CH.dbd.CH-- in the alkenyl depends on a position
of a double bond. Trans is preferred in the alkenyl such as
1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl and
3-hexenyl for decreasing the viscosity, for instance. C is
preferred in the alkenyl such as 2-butenyl, 2-pentenyl and
2-hexenyl. In the alkenyl, straight-chain alkenyl is preferred to
branched-chain alkenyl.
[0069] Preferred examples of alkenyl in which at least one of
hydrogen is replaced by fluorine include 2,2-difluorovinyl,
3,3-difluoro-2-propenyl, 4,4-difluoro-3-butenyl,
5,5-difluoro-4-pentenyl and 6,6-difluoro-5-hexenyl. Further
preferred examples include 2,2-difluorovinyl and
4,4-difluoro-3-butenyl for decreasing the viscosity.
[0070] Ring A and ring C are independently 1,4-cyclohexylene,
1,4-phenylene, 1,4-phenylene in which at least one of hydrogen is
replaced by fluorine or chlorine, or tetrahydropyran-2,5-diyl.
Tetrahydropyran-2,5-diyl includes:
##STR00011##
preferably,
##STR00012##
[0071] Tetrahydropyran-2,5-diyl is left-right asymmetric. However,
the rings are defined to be allowed in a position not only in a
defined direction but also in a reverse left-right direction as
described above. The definition also applies to any other ring in
which only one of left and right is defined in a left-right
asymmetric ring.
[0072] Ring B is 2,3-difluoro-1,4-phenylene,
2-chloro-3-fluoro-1,4-phenylene,
2,3-difluoro-5-methyl-1,4-phenylene,
3,4,5-trifluoronaphthalene-2,6-diyl or
7,8-difluorochroman-2,6-diyl, and two of arbitrary ring A when p is
2 or 3 may be identical or different. Preferred ring A or ring C is
1,4-cyclohexylene for decreasing the viscosity. Preferred ring B is
2,3-difluoro-1,4-phenylene for decreasing the viscosity and
increasing the absolute value of the dielectric anisotropy. Ring D
and ring E are independently 1,4-cyclohexylene, 1,4-phenylene,
2-fluoro-1,4-phenylene or 3-fluoro-1,4-phenylene, and two of
arbitrary ring D when s is 2 or 3 may be identical or different.
Preferred ring D or ring E is 1,4-cyclohexylene for decreasing the
viscosity, and 1,4-phenylene for increasing the optical anisotropy.
With regard to a configuration of 1,4-cyclohexylene, trans is
preferred to cis for increasing the maximum temperature. Then,
"2-fluoro-1,4-phenylene" or the like is described by defining a
left-side position on a ring as position 1, and
"2-fluoro-1,4-phenylene" and "3-fluoro-1,4-phenylene" indicate that
a position of fluorine is different.
[0073] Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5 and Z.sup.6 are
independently a single bond, --O--, --S--, --CO--, --CO--O--,
--O--CO--, --O--CO--O-- or alkylene having 1 to 12 carbons. Two of
arbitrary Z.sup.4 or Z.sup.6 when n is an integer from 2 to 12 may
be identical or different. Preferred Z.sup.1, Z.sup.2, Z.sup.3,
Z.sup.4, Z.sup.5 or Z.sup.6 is a single bond or --O-- for
increasing the photoreactivity. Z.sup.7 is --O--, --S--, --CO--,
--CO--O--, --O--CO--, --O--CO--O--, --OCH.sub.2--, --CH.sub.2O--,
--SCH.sub.2--, --CH.sub.2S--, --CF.sub.2O--, --OCF.sub.2--,
--CF.sub.2S--, --SCF.sub.2--, --(CR.sup.7R.sup.8).sub.m--,
--(CR.sup.7.dbd.CR.sup.8).sub.m--, --C.ident.C--,
--CR.sup.7.dbd.CR.sup.8--CO--O--, --O--CO--CR.sup.7.dbd.CR.sup.8--,
--CO--NR.sup.7--, --NR.sup.7--CO--, --CO--S--, --S--CO--,
--O--CO--CR.sup.7--CR.sup.8--O--, --O--CR.sup.7--CR.sup.8--CO--O--,
--CR.sup.7.dbd.CR.sup.8--CO--, --CO--CR.sup.7.dbd.CR.sup.8--,
--C(.dbd.CR.sup.7R.sup.8)--,
--O--CO--CR.sup.7R.sup.8--CR.sup.9--O--CR.sup.7R.sup.8--CR.sup.9R.sup.10--
-CO--O-- or a single bond. Two of arbitrary Z.sup.7 when n is an
integer from 2 to 12 may be identical or different. Preferred
Z.sup.7 is --O--, --CO--, --CO--O--, --O--CO--, --O--CO--O--,
--OCH.sub.2--, --CH.sub.2O--, --CF.sub.2O--, --OCF.sub.2--,
--(CR.sup.7R.sup.8).sub.m-- or a single bond. Further preferred
Z.sup.7 is --O--, --CH.sub.2-- or a single bond for increasing
reactivity by exposure to ultraviolet light. Z.sup.8, Z.sup.9 and
Z.sup.10 are independently a single bond, ethylene, methyleneoxy or
carbonyloxy, two of arbitrary Z.sup.8 when p is 2 or 3 may be
identical or different, and two of arbitrary Z.sup.10 when s is 2
or 3 may be identical or different. Preferred Z.sup.8 or Z.sup.9 is
a single bond for decreasing the viscosity, and methyleneoxy for
increasing the absolute value of the dielectric anisotropy.
Preferred Z.sup.10 is a single bond for decreasing the
viscosity.
[0074] X.sup.1 and X.sup.2 are independently hydrogen, --CH.sub.3,
--C.sub.2H.sub.5 or halogen. Preferred X' or X.sup.2 is hydrogen
for increasing the photoreactivity. X.sup.3 is hydrogen,
--CH.sub.3, --C.sub.2H.sub.5, halogen or --CF.sub.3. Preferred
X.sup.3 is hydrogen or --CH.sub.3 for increasing the
photoreactivity.
[0075] Then, m is 1, 2, 3 or 4. Preferred m is 1 or 2 for
increasing the photoreactivity. Herein, n is an integer from 1 to
12. Preferred n is 1 or 2 for increasing the photoreactivity.
Moreover, p is 1, 2 or 3, r is 0 or 1, and a sum of p and r is 3 or
less. Preferred p is 1 for decreasing the minimum temperature.
Preferred r is 0 for decreasing the viscosity. Furthermore, s is 1,
2 or 3. Preferred s is 1 for decreasing the viscosity, and 3 for
increasing the maximum temperature.
[0076] Fifth, the specific examples of the component compounds will
be shown. In the preferred compounds described below, R.sup.15 and
R.sup.16 are independently hydrogen, hydroxy, acryloyloxy or
methacryloyloxy. R.sup.17 is straight-chain alkyl having 1 to 12
carbons or straight-chain alkoxy having 1 to 12 carbons. R.sup.18
and R.sup.19 are independently straight-chain alkyl having 1 to 12
carbons or straight-chain alkenyl having 2 to 12 carbons.
[0077] Preferred compound (1) includes compound (1-1-1) and
compound (1-2-1). Further preferred compound (1) includes compound
(1-1-1). Preferred compound (2) includes compound (2-1-1) to
compound (2-19-1). Further preferred compound (2) includes compound
(2-1-1), compound (2-2-1), compound (2-4-1), compound (2-6-1),
compound (2-8-1), compound (2-11-1) and compound (2-13-1).
Particularly preferred compound (2) includes compound (2-1-1),
compound (2-4-1), compound (2-6-1), compound (2-8-1) and compound
(2-13-1). Preferred compound (3) includes compound (3-1-1) to
compound (3-13-1). Further preferred compound (3) includes compound
(3-1-1), compound (3-3-1), compound (3-5-1), compound (3-7-1) and
compound (3-9-1). Particularly preferred compound (3) includes
compound (3-1-1), compound (3-5-1) and compound (3-7-1).
##STR00013## ##STR00014## ##STR00015## ##STR00016##
[0078] Sixth, the additive that may be mixed with the composition
will be explained. Such an additive includes the optically active
compound, the antioxidant, the ultraviolet light absorber, the dye,
the antifoaming agent, the polymerization initiator and the
polymerization inhibitor. The optically active compound is mixed
with the composition for the purpose of inducing a helical
structure in liquid crystals to give a twist angle. Examples of
such a compound include compound (4-1) to compound (4-4). A
preferred ratio of the optically active compound is approximately
5% by weight or less. A further preferred ratio is in the range of
approximately 0.01% by weight to approximately 2% by weight.
##STR00017##
[0079] The antioxidant is mixed with the composition for the
purpose of preventing a decrease in the specific resistance caused
by heating in air, or maintaining a large voltage holding ratio at
room temperature and also at a temperature close to the maximum
temperature of the nematic phase even after the device has been
used for a long period of time.
##STR00018##
[0080] Preferred examples of the antioxidant include compound (5)
where t is an integer from 1 to 9. In compound (5), preferred t is
1, 3, 5, 7 or 9. Further preferred t is 1 or 7. Compound (5) where
t is 1 is effective in preventing a decrease in the specific
resistance caused by heating in air because the compound (5) has a
large volatility. Compound (5) where t is 7 is effective in
maintaining a large voltage holding ratio at room temperature and
also at a temperature close to the maximum temperature of the
nematic phase even after the device has been used for a long period
of time because the compound (5) has a small volatility. A
preferred ratio of the antioxidant is approximately 50 ppm or more
for achieving the effect thereof, and approximately 600 ppm or less
for avoiding a decrease in the maximum temperature or avoiding an
increase in the minimum temperature. A further preferred ratio is
in the range of approximately 100 ppm to approximately 300 ppm.
[0081] Preferred examples of the ultraviolet light absorber include
a benzophenone derivative, a benzoate derivative and a triazole
derivative. A light stabilizer such as an amine having steric
hindrance is also preferred. A preferred ratio of the ultraviolet
light absorber or the stabilizer is approximately 50 ppm or more
for achieving the effect thereof, and approximately 10,000 ppm or
less for avoiding a decrease in the maximum temperature or avoiding
an increase in the minimum temperature. A further preferred ratio
is in the range of approximately 100 ppm to approximately 10,000
ppm.
[0082] A dichroic dye such as an azo dye or an anthraquinone dye is
mixed with the composition to be adapted for a device having a
guest host (GH) mode. A preferred ratio of the dye is in the range
of approximately 0.01% by weight to approximately 10% by
weight.
[0083] The antifoaming agent such as dimethyl silicone oil or
methyl phenyl silicone oil is mixed with the composition for
preventing foam formation. A preferred ratio of the antifoaming
agent is approximately 1 ppm or more for achieving the effect
thereof, and approximately 1,000 ppm or less for avoiding a poor
display. A further preferred ratio is in the range of approximately
1 ppm to approximately 500 ppm.
[0084] The liquid crystal composition of the invention is suitable
for use in the device having the polymer sustained alignment (PSA)
mode because the composition contains the polymerizable compound.
The composition may further contain a polymerizable compound other
than compound (1). Preferred examples of the polymerizable compound
include a compound having a polymerizable group, such as an
acrylate, a methacrylate, a vinyl compound, a vinyloxy compound, a
propenyl ether, an epoxy compound (oxirane, oxetane) and a vinyl
ketone. Particularly preferred examples include an acrylate
derivative or a methacrylate derivative. A preferred ratio of the
polymerizable compound is approximately 0.05% by weight or more for
achieving the effect thereof, and approximately 10% by weight or
less for avoiding a poor display. A further preferred ratio is in
the range of approximately 0.1% by weight to approximately 2% by
weight. The polymerizable compound is preferably polymerized by
irradiation with ultraviolet light or the like in the presence of a
suitable initiator such as a photopolymerization initiator.
Suitable conditions for polymerization, suitable types of the
initiator and suitable amounts thereof are known to a person
skilled in the art and are described in literatures. For example,
Irgacure 651 (registered trademark; BASF), Irgacure 184 (registered
trademark; BASF) or Darocure 1173 (registered trademark; BASF),
each being a photoinitiator, is suitable for radical
polymerization. A preferred ratio of the photopolymerization
initiator is in the range of approximately 0.1% by weight to
approximately 5% by weight of the polymerizable compound, and a
further preferred ratio is in the range of approximately 1% by
weight to approximately 3% by weight. A polymerized compound may be
arranged through a process of arranging the liquid crystal
composition containing the polymerizable compound between two
substrates in the liquid crystal display device and polymerizing
the polymerizable compound while applying a voltage between
opposing electrode layers on the substrates, or a liquid crystal
composition containing a preliminarily polymerized compound may be
arranged between the two substrates in the liquid crystal display
device.
[0085] Seventh, the methods for synthesizing the component
compounds will be explained. The compounds can be prepared
according to known methods. Examples of synthetic methods are
shown. Compound (1-1-1) is commercially available from
Shin-Nakamura Chemical Co., Ltd. Compound (2-1-1) is prepared by
the method described in JP 2000-053602 A (2000). Compound (3-1-1)
and compound (3-5-1) are prepared by the method described in JP
S59-176221 A (1984). The antioxidant is commercially available. A
compound represented by formula (5) where t is 1 is available from
Sigma-Aldrich Corporation. Compound (5) where t is 7 and so forth
are prepared according to the method described in U.S. Pat. No.
3,660,505 B.
[0086] Any compounds whose synthetic methods are not described
above can be prepared according to the methods described in books
such as Organic Syntheses (John Wiley & Sons, Inc.), Organic
Reactions (John Wiley & Sons, Inc.), Comprehensive Organic
Synthesis (Pergamon Press) and New Experimental Chemistry Course
(Shin Jikken Kagaku Koza in Japanese) (Maruzen Co., Ltd.). The
composition is prepared according to publicly known methods using
the thus obtained compounds. For example, the component compounds
are mixed and dissolved in each other by heating.
[0087] Last, the application of the composition will be explained.
Most of the compositions have a minimum temperature of
approximately -10.degree. C. or lower, a maximum temperature of
approximately 70.degree. C. or higher and an optical anisotropy in
the range of approximately 0.07 to approximately 0.20. The device
containing the composition has a large voltage holding ratio. The
composition is suitable for use in the AM device. The composition
is particularly suitable for use in a transmissive AM device. A
composition having an optical anisotropy in the range of
approximately 0.08 to approximately 0.25 may be prepared by
controlling the ratio of the component compounds or by mixing with
any other liquid crystal compound. The composition can be used as
the composition having the nematic phase, and as the optically
active composition by adding the optically active compound.
[0088] The composition can be used for the AM device. The
composition can also be used for a PM device. The composition can
be used for an AM device and a PM device both having a mode such as
PC, TN, STN, ECB, OCB, IPS, VA or PSA. Use for the AM device having
the PSA mode is particularly preferred. The devices may be of a
reflective type, a transmissive type or a transflective type. Use
for the transmissive device is preferred. The composition can also
be used for an amorphous silicon-TFT device or a polycrystal
silicon-TFT device. The composition can also be used for a nematic
curvilinear aligned phase (NCAP) device prepared by
microencapsulating the composition, and for a polymer dispersed
(PD) device in which a three-dimensional network-polymer is formed
in the composition.
[0089] The liquid crystal display device of the invention is
characterized by comprising two substrates having an electrode
layer on at least one of the substrates, and arranging between the
two substrates the liquid crystal composition of the invention or a
liquid crystal composition containing a compound formed by
polymerization of the compound of the invention. For example, the
liquid crystal display device comprises two glass substrates
referred to as an array substrate and a color filter substrate, and
a thin film transistor (TFT), pixels, a coloring layer and so forth
are formed on each of the glass substrates. An aluminosilicate
glass or aluminoborosilicate glass is used for each of the glass
substrates, for example. For the electrode layer, Indium-Tin Oxide
and Indium-Zinc Oxide are generally used.
[0090] It will be apparent to those skilled in the art that various
modifications and variations can be made in the invention and
specific examples provided herein without departing from the spirit
or scope of the invention. Thus, it is intended that the invention
covers the modifications and variations of this invention that come
within the scope of any claims and their equivalents.
[0091] The following examples are for illustrative purposes only
and are not intended, nor should they be interpreted to, limit the
scope of the invention.
EXAMPLES
[0092] In order to evaluate characteristics of a composition and a
compound to be contained in the composition, the composition and
the compound were made a measurement object. When the measurement
object was the composition, the measurement object was measured as
a sample as is, and values obtained were described. When the
measurement object was the compound, a sample for measurement was
prepared by mixing the compound (15% by weight) into mother liquid
crystals (85% by weight). Values of characteristics of the compound
were calculated using values obtained by measurement, according to
an extrapolation method: (extrapolated value)={(measured value of a
sample for measurement)-0.85.times.(measured value of mother liquid
crystals)}/0.15. When a smectic phase (or crystals) precipitated at
the above ratio at 25.degree. C., a ratio of the compound to the
mother liquid crystals was changed step by step in the order of
(10% by weight: 90% by weight), (5% by weight: 95% by weight) and
(1% by weight: 99% by weight). Values of a maximum temperature, an
optical anisotropy, viscosity and a dielectric anisotropy with
regard to the compound were determined according to the
extrapolation method.
[0093] Components of the mother liquid crystals and the ratio
thereof were as described below.
##STR00019##
[0094] Characteristics were measured according to the methods
described below. Most of the methods are applied as described in
Standard of Japan Electronics and Information Technology Industries
Association, hereafter abbreviated as JEITA) discussed and
established as Standard of JEITA (JEITA ED-2521B), or as modified
thereon.
[0095] Maximum Temperature of a Nematic Phase (NI; .degree.
C.):
[0096] A sample was placed on a hot plate in a melting point
apparatus equipped with a polarizing microscope and was heated at a
rate of 1.degree. C. per minute. Temperature when a part of the
sample began to change from a nematic phase to an isotropic liquid
was measured. A higher limit of a temperature range of the nematic
phase may be abbreviated as "maximum temperature."
[0097] Minimum Temperature of a Nematic Phase (T.sub.c; .degree.
C.):
[0098] A sample having a nematic phase was put in glass vials and
kept in freezers at temperatures of 0.degree. C., -10.degree. C.,
-20.degree. C., -30.degree. C. and -40.degree. C. for 10 days, and
then liquid crystal phases were observed. For example, when the
sample maintained the nematic phase at -20.degree. C. and changed
to crystals or a smectic phase at -30.degree. C., T.sub.c was
expressed as T.sub.c<-20.degree. C. A lower limit of the
temperature range of the nematic phase may be abbreviated as
"minimum temperature."
[0099] Viscosity (bulk viscosity; q; measured at 20.degree. C.;
mPas):
[0100] A cone-plate (E type) viscometer was used for
measurement.
[0101] Optical Anisotropy (refractive index anisotropy; .DELTA.n;
measured at 25.degree. C.):
[0102] Measurement was carried out by means of an Abbe
refractometer with a polarizing plate mounted on an ocular, using
light at a wavelength of 589 nanometers. A surface of a main prism
was rubbed in one direction, and then a sample was added dropwise
onto the main prism. A refractive index (n.parallel.) was measured
when the direction of polarized light was parallel to the direction
of rubbing. A refractive index (n.perp.) was measured when the
direction of polarized light was perpendicular to the direction of
rubbing. A value of optical anisotropy was calculated from an
equation: .DELTA.n=n.parallel.-n.perp..
[0103] Dielectric Anisotropy (.DELTA..di-elect cons.; measured at
25.degree. C.):
[0104] A value of dielectric anisotropy was calculated from an
equation: .DELTA..di-elect cons.=.di-elect
cons..parallel.-.di-elect cons..perp.. A dielectric constant
(.di-elect cons..parallel. and .parallel..perp.) was measured as
described below.
[0105] (1) Measurement of dielectric constant (.di-elect
cons..parallel.): An ethanol (20 mL) solution of octadecyl
triethoxysilane (0.16 mL) was applied to a well-washed glass
substrate. After rotating the glass substrate with a spinner, the
glass substrate was heated at 150.degree. C. for 1 hour. A sample
was put in a VA device in which a distance (cell gap) between two
glass substrates was 4 micrometers, and the device was sealed with
an ultraviolet-curable adhesive. Sine waves (0.5 V, 1 kHz) were
applied to the device, and after 2 seconds, a dielectric constant
(.di-elect cons..perp.) in the major axis direction of liquid
crystal molecules was measured.
[0106] (2) Measurement of dielectric constant (.di-elect
cons..perp.): A polyimide solution was applied to a well-washed
glass substrate. After calcining the glass substrate, rubbing
treatment was applied to the alignment film obtained. A sample was
put in a TN device in which a distance (cell gap) between two glass
substrates was 9 micrometers and a twist angle was 80 degrees. Sine
waves (0.5 V, 1 kHz) were applied to the device, and after 2
seconds, a dielectric constant (.di-elect cons..perp.) in the minor
axis direction of the liquid crystal molecules was measured.
[0107] Threshold Voltage (Vth; measured at 25.degree. C.; V):
[0108] An LCD-5100 luminance meter made by Otsuka Electronics Co.,
Ltd. was used for measurement. A light source was a halogen lamp. A
sample was put in a normally black mode VA device in which a
distance (cell gap) between two glass substrates was 4 micrometers
and a rubbing direction was anti-parallel, and the device was
sealed with an ultraviolet-curable adhesive. A voltage (60 Hz,
rectangular waves) to be applied to the device was stepwise
increased from 0 V to 20 V at an increment of 0.02 V. On the
occasion, the device was irradiated with light from a direction
perpendicular to the device, and the amount of light passing
through the device was measured. A voltage-transmittance curve was
prepared, in which the maximum amount of light corresponds to 100%
transmittance and the minimum amount of light corresponds to 0%
transmittance. A threshold voltage is voltage at 10%
transmittance.
[0109] Voltage Holding Ratio (VHR-1; measured at 25.degree. C.;
%):
[0110] A TN device used for measurement had a polyimide alignment
film, and a distance (cell gap) between two glass substrates was 5
micrometers. A sample was put in the device, and then the device
was sealed with an ultraviolet-curable adhesive. A pulse voltage
(60 microseconds at 5 V) was applied to the TN device and the
device was charged. A decaying voltage was measured for 16.7
milliseconds with a high-speed voltmeter, and area A between a
voltage curve and a horizontal axis in a unit cycle was determined.
Area B is an area without decay. A voltage holding ratio is a
percentage of area A to area B.
[0111] Voltage Holding Ratio (VHR-2; measured at 80.degree. C.;
%):
[0112] A TN device used for measurement had a polyimide alignment
film, and a distance (cell gap) between two glass substrates was 5
micrometers. A sample was put in the device, and then the device
was sealed with an ultraviolet-curable adhesive. A pulse voltage
(60 microseconds at 5 V) was applied to the TN device and the
device was charged. A decaying voltage was measured for 16.7
milliseconds with a high-speed voltmeter, and area A between a
voltage curve and a horizontal axis in a unit cycle was determined.
Area B is an area without decay. A voltage holding ratio is a
percentage of area A to area B.
[0113] Voltage Holding Ratio (VHR-3; measured at 25.degree. C.;
%):
[0114] Stability to ultraviolet light was evaluated by measuring a
voltage holding ratio after a device was irradiated with
ultraviolet light. A TN device used for measurement had a polyimide
alignment film and a cell gap was 5 micrometers. A sample was
injected into the device, and then the device was irradiated with
light for 20 minutes. Alight source was an ultra high-pressure
mercury lamp USH-500D (made by Ushio, Inc.), and a distance between
the device and the light source was 20 centimeters. In measuring
VHR-3, a decaying voltage was measured for 16.7 milliseconds. A
composition having a large VHR-3 has a large stability to
ultraviolet light. A value of VHR-3 is preferably 90% or more,
further preferably, 95% or more.
[0115] Voltage Holding Ratio (VHR-4; measured at 25.degree. C.;
%):
[0116] A TN device into which a sample was injected was heated in a
constant-temperature bath at 80.degree. C. for 500 hours, and then
stability to heat was evaluated by measuring a voltage holding
ratio. In measuring VHR-4, a decaying voltage was measured for 16.7
milliseconds. A composition having a large VHR-4 has a large
stability to heat.
[0117] Response Time (t; measured at 25.degree. C.; ms):
[0118] An LCD-5100 luminance meter made by Otsuka Electronics Co.,
Ltd. was used for measurement. A light source was a halogen lamp. A
low-pass filter was set at 5 kHz. A sample was put in a normally
black mode PVA device in which a distance (cell gap) between two
glass substrates was 3.2 micrometers and a rubbing direction was
anti-parallel, and the device was sealed with an
ultraviolet-curable adhesive. The device was irradiated with
ultraviolet light of 25 mW/cm.sup.2 (EXECURE4000-D lamp made by
HOYA CANDEO OPTRONICS CORPORATION) for 400 seconds while applying a
voltage of 15 V. Rectangular waves (60 Hz, 10 V, 0.5 second) were
applied to the device. On the occasion, the device was irradiated
with light from a direction perpendicular to the device, and the
amount of light passing through the device was measured. The
maximum amount of light corresponds to 100% transmittance, and the
minimum amount of light corresponds to 0% transmittance. A response
time is a period of time required for a change from 0%
transmittance to 90% transmittance (rise time; millisecond).
[0119] Specific Resistance (.rho.; measured at 25.degree. C.;
.OMEGA.om):
[0120] Into a vessel equipped with an electrode, 1.0 milliliter of
a sample was injected. A DC voltage (10 V) was applied to the
vessel, and a DC current after 10 seconds was measured. A specific
resistance was calculated from the following equation: (specific
resistance)={(voltage).times.(electric capacity of a vessel)}/{(DC
current).times.(dielectric constant of vacuum)}.
[0121] Gas Chromatographic Analysis:
[0122] GC-14B Gas Chromatograph made by Shimadzu Corporation was
used for measurement. A carrier gas was helium (2 mL per minute). A
sample injector and a detector (FID) were set to 280.degree. C. and
300.degree. C., respectively. A capillary column DB-1 (length 30 m,
bore 0.32 mm, film thickness 0.25 .mu.m; dimethylpolysiloxane as a
stationary phase, non-polar) made by Agilent Technologies, Inc. was
used for separation of component compounds. After the column was
kept at 200.degree. C. for 2 minutes, the column was heated to
280.degree. C. at a rate of 5.degree. C. per minute. A sample was
prepared in an acetone solution (0.1% by weight), and then 1
microliter of the solution was injected into the sample injector. A
recorder was C-R5A Chromatopac made by Shimadzu Corporation or the
equivalent thereof. The resulting gas chromatogram showed a
retention time of a peak and a peak area corresponding to each of
the component compounds.
[0123] As a solvent for diluting the sample, chloroform, hexane and
so forth may also be used. The following capillary columns may also
be used for separating component compounds: HP-1 (length 30 m, bore
0.32 mm, film thickness 0.25 .mu.m) made by Agilent Technologies,
Inc., Rtx-1 (length 30 m, bore 0.32 mm, film thickness 0.25 .mu.m)
made by Restek Corporation and BP-1 (length 30 m, bore 0.32 mm,
film thickness 0.25 .mu.m) made by SGE International Pty. Ltd. A
capillary column CBP1-M50-025 (length 50 m, bore 0.25 mm, film
thickness 0.25 .mu.m) made by Shimadzu Corporation may also be used
for the purpose of avoiding an overlap of peaks of the
compounds.
[0124] A ratio of liquid crystal compounds included in the
composition may be calculated by the method as described below. The
liquid crystal compounds can be detected by means of a gas
chromatograph. A ratio of peak areas in a gas chromatogram
corresponds to a ratio (in the number of moles) of the liquid
crystal compounds. When the capillary columns described above were
used, a correction coefficient of each of the liquid crystal
compounds may be regarded as 1 (one). Accordingly, a ratio (% by
weight) of the liquid crystal compounds was calculated from the
ratio of the peak areas.
[0125] The invention will be explained in detail by way of
Examples. The invention is not limited by the Examples described
below. The compounds in Comparative Examples and Examples were
described using symbols according to definitions in Table 3 below.
In Table 3, a configuration of 1,4-cyclohexylene is trans. A
parenthesized number next to a symbolized compound corresponds to
the number of the compound. A symbol (-) means any other liquid
crystal compound. A ratio (percentage) of the liquid crystal
compounds is expressed in terms of weight percent (% by weight)
based on the weight of the liquid crystal composition excluding the
first composition. The liquid crystal composition further includes
an impurity in addition thereto. Last, values of characteristics of
the composition were summarized.
TABLE-US-00003 TABLE 3 Method for Description of Compounds using
Symbols R--(A.sub.1)--Z.sub.1-- . . . --Z.sub.n--(A.sub.n)--R' 1)
Left-terminal Group R-- Symbol C.sub.nH.sub.2n+1-- n-
C.sub.nH.sub.2n+1O-- nO-- C.sub.mH.sub.2m+1OC.sub.nH.sub.2n-- mOn--
CH.sub.2.dbd.CH-- V-- C.sub.nH.sub.2n+1--CH.dbd.CH-- nV--
CH.sub.2.dbd.CH--C.sub.nH.sub.2n-- Vn--
C.sub.mH.sub.2m+1--CH.dbd.CH--C.sub.nH.sub.2n-- mVn--
CF.sub.2.dbd.CH-- VFF-- CF.sub.2.dbd.CH--C.sub.nH.sub.2n-- VFFn--
CH.sub.2.dbd.CHCOO-- AC-- CH.sub.2.dbd.C(CH.sub.3)COO-- MAC-- 2)
Right-terminal Group --R' Symbol --C.sub.nH.sub.2n+1 -n
--OC.sub.nH.sub.2n+1 --On --CH.dbd.CH.sub.2 --V
--CH.dbd.CH--C.sub.nH.sub.2n+1 --Vn
--C.sub.nH.sub.2n--CH.dbd.CH.sub.2 --nV --CH.dbd.CF.sub.2 --VFF
--COOCH.sub.3 --EMe --OCOCH.dbd.CH.sub.2 --AC
--OCOC(CH.sub.3).dbd.CH.sub.2 --MAC 3) Bonding Group --Z.sub.n--
Symbol --C.sub.2H.sub.4-- 2 --COO-- E --CH.dbd.CH-- V --C.ident.C--
T --CF.sub.2O-- X --CH.sub.2O-- 1O --SiH.sub.2-- Si 4) Ring
Structure --A.sub.n-- Symbol ##STR00020## H ##STR00021## Dh
##STR00022## dh ##STR00023## B ##STR00024## B(F) ##STR00025## B(2F)
##STR00026## B(2F,5F) ##STR00027## B(2F,3F) ##STR00028##
B(2F,3F,6Me) ##STR00029## B(2F,3CL) ##STR00030## Np ##STR00031##
Np(3F,4F,5F) ##STR00032## Cro(7F,8F) 5) Examples of Description
Example 1 3-HB(2F,3F)-O2 ##STR00033## Example 2 3-HDhB(2F,3F)-O2
##STR00034##
Comparative Example 1
[0126] The composition is a liquid crystal composition without
containing a first component of the invention. Components and
characteristics of the composition are as described below.
TABLE-US-00004 3-BB(2F,3F)-O2 (2-4-1) 8% 5-BB(2F,3F)-O2 (2-4-1) 10%
2-HH1OB(2F,3F)-O2 (2-8-1) 5% 3-HH1OB(2F,3F)-O2 (2-8-1) 10%
3-DhHB(2F,3F)-O2 (2-10-1) 5% 3-HDhB(2F,3F)-O2 (2-11-1) 6%
5-DhH1OB(2F,3F)-O2 (2-12-1) 3% 3-dhBB(2F,3F)-O2 (2-14-1) 6%
3-HEB(2F,3F)B(2F,3F)-O4 (2-15-1) 4% 2-HH-3 (3-1-1) 16% 3-HH-4
(3-1-1) 5% 1-BB-3 (3-3-1) 5% 3-HHB-1 (3-5-1) 3% 3-HHB-3 (3-5-1) 3%
V-HHB-1 (3-5-1) 3% 5-B(F)BB-2 (3-7-1) 4% 5-B(F)BB-2 (3-7-1) 4% NI =
85.6.degree. C.; Tc < -20.degree. C.; .DELTA.n = 0.120;
.DELTA..epsilon. = -3.9; Vth = 2.07 V; .tau. = 8.0 ms; VHR-1 =
99.2%; VHR-2 = 98.1%.
Example 1
TABLE-US-00005 [0127] 3-BB(2F,3F)-O2 (2-4-1) 8% 5-BB(2F,3F)-O2
(2-4-1) 10% 2-HH1OB(2F,3F)-O2 (2-8-1) 5% 3-HH1OB(2F,3F)-O2 (2-8-1)
10% 3-DhHB(2F,3F)-O2 (2-10-1) 5% 3-HDhB(2F,3F)-O2 (2-11-1) 6%
5-DhH1OB(2F,3F)-O2 (2-12-1) 3% 3-dhBB(2F,3F)-O2 (2-14-1) 6%
3-HEB(2F,3F)B(2F,3F)-O4 (2-15-1) 4% 2-HH-3 (3-1-1) 16% 3-HH-4
(3-1-1) 5% 1-BB-3 (3-3-1) 5% 3-HHB-1 (3-5-1) 3% 3-HHB-3 (3-5-1) 3%
V-HHB-1 (3-5-1) 3% 5-B(F)BB-2 (3-7-1) 4% 5-B(F)BB-2 (3-7-1) 4%
[0128] Into 100 parts by weight of the composition, 0.40 part by
weight of compound (1-1-1-1) described below was added.
##STR00035##
NI=85.5.degree. C.; Tc<-20.degree. C.; .DELTA.n=0.120;
.DELTA..di-elect cons.=-3.9; Vth=2.06 V; .tau.=5.9 ms; VHR-1=99.2%;
VHR-2=98.1%.
Example 2
TABLE-US-00006 [0129] 3-H2B(2F,3F)-O2 (2-2-1) 19% 5-H2B(2F,3F)-O2
(2-2-1) 15% 5-HH2B(2F,3F)-O2 (2-7-1) 5% 3-HBB(2F,3F)-O2 (2-13-1)
10% 5-HBB(2F,3F)-O2 (2-13-1) 4% 3-HHB(2F,3CL)-O2 (2-16-1) 3%
V-HBB(2F,3CL)-O2 (2-17-1) 3% 2-HH-3 (3-1-1) 25% 3-HHEH-3 (3-4-1) 3%
3-HHB-O1 (3-5) 4% 3-HBB-2 (3-6-1) 3% 3-HB(F) HH-5 (3-10-1) 3%
5-HBBH-3 (3-11-1) 3%
[0130] Into 100 parts by weight of the composition, 0.3 part by
weight of compound (1-1-1-1) described below was added.
##STR00036##
NI=81.0.degree. C.; Tc<-20.degree. C.; .DELTA.n=0.090;
.DELTA..di-elect cons.=-2.8; Vth=2.38 V; .tau.=5.3 ms; VHR-1=99.2%;
VHR-2=97.6%.
Example 3
TABLE-US-00007 [0131] 3-H2B(2F,3F)-O2 (2-2-1) 20% 5-H2B(2F,3F)-O2
(2-2-1) 15% 2-BB(2F,3F)B-3 (2-9-1) 7% 3-DhHB(2F,3F)-O2 (2-10-1) 5%
3-HBB(2F,3F)-O2 (2-13-1) 10% 4-HBB(2F,3F)-O2 (2-13-1) 5%
3-H1OCro(7F,8F)-5 (2-18-1) 3% 3-HH1OCro(7F,8F)-5 (2-19-1) 3% 2-HH-3
(3-1-1) 15% 3-HH-4 (3-1-1) 5% 3-HHB-O1 (3-5) 3% 3-HHEBH-3 (3-9-1)
3% 3-HB(F)BH-3 (3-12-1) 3% 5-HBB(F)B-2 (3-13-1) 3%
[0132] Into 100 parts by weight of the composition, 0.3 part by
weight of compound (1-1-1-1) described below was added.
##STR00037##
NI=79.8.degree. C.; Tc<-20.degree. C.; .DELTA.n=0.105;
.DELTA..di-elect cons.=-3.8; Vth=2.11 V; .tau.=5.5 ms; VHR-1=99.3%;
VHR-2=97.9%.
Example 4
TABLE-US-00008 [0133] 3-H2B(2F,3F)-O2 (2-2-1) 20% 5-H2B(2F,3F)-O2
(2-2-1) 12% 3-HHB(2F,3F)-O2 (2-6-1) 8% 3-HHB(2F,3F)-1 (2-6-1) 5%
3-HDhB(2F,3F)-O2 (2-11-1) 5% 3-HBB(2F,3F)-O2 (2-13-1) 10%
4-HBB(2F,3F)-O2 (2-13-1) 6% 5-HBB(2F,3F)-O2 (2-13-1) 3% 2-HH-3
(3-1-1) 10% 3-HH-4 (3-1-1) 10% 1V-HH-3 (3-1-1) 8% 3-HHB-1 (3-5-1)
3%
[0134] Into 100 parts by weight of the composition, 0.4 part by
weight of compound (1-1-1-1) described below was added.
##STR00038##
NI=77.2.degree. C.; Tc<-20.degree. C.; .DELTA.n=0.090;
.DELTA..di-elect cons.=-3.6; Vth=2.09 V; .tau.=5.2 ms; VHR-1=99.1%;
VHR-2=98.2%.
Example 5
TABLE-US-00009 [0135] 3-BB(2F,3F)-O2 (2-4-1) 9% 5-BB(2F,3F)-O2
(2-4-1) 6% 2-HH1OB(2F,3F)-O2 (2-8-1) 13% 3-HH1OB(2F,3F)-O2 (2-8-1)
21% 2-HH-3 (3-1-1) 20% 3-HH-4 (3-1-1) 8% 3-HB-O2 (3-2) 5% 1-BB-3
(3-3-1) 7% 3-HHB-1 (3-5-1) 3% 3-HHB-O1 (3-5) 4% 5-B(F)BB-2 (3-7-1)
4%
[0136] Into 100 parts by weight of the composition, 0.3 part by
weight of compound (1-1-1-1) described below was added.
##STR00039##
NI=75.8.degree. C.; Tc<-20.degree. C.; .DELTA.n=0.100;
.DELTA..di-elect cons.=-3.3; Vth=2.22 V; .tau.=4.2 ms; VHR-1=99.0%;
VHR-2=97.9%.
Example 6
TABLE-US-00010 [0137] 3-HB(2F,3F)-O2 (2-1-1) 12% V-HB(2F,3F)-O2
(2-1-1) 11% V-HB(2F,3F)-O4 (2-1-1) 8% 1V2-HB(2F,3F)-O2 (2-1-1) 4%
3-HBB(2F,3F)-O2 (2-13-1) 10% 4-HBB(2F,3F)-O2 (2-13-1) 6%
5-HBB(2F,3F)-O2 (2-13-1) 10% 3-HH1OCro(7F,8F)-5 (2-19-1) 5% V-HH-3
(3-1-1) 13% VFF-HH-3 (3-1) 5% 3-HHB-1 (3-5-1) 3% 3-HHB-O1 (3-5) 3%
3-HHB-3 (3-5-1) 3% 5-HBB(F)B-2 (3-13-1) 4% 1O1-HBBH-5 (--) 3%
[0138] Into 100 parts by weight of the composition, 0.2 part by
weight of compound (1-1-1-1) described below,
##STR00040##
and 0.2 part by weight of compound (1-2-1-1) described below were
added.
##STR00041##
NI=84.7.degree. C.; Tc<-20.degree. C.; .DELTA.n=0.108;
.DELTA..di-elect cons.=-3.7; Vth=1.94 V; .tau.=6.4 ms; VHR-1=99.1%;
VHR-2=97.9%.
Example 7
TABLE-US-00011 [0139] 3-H1OB(2F,3F)-O2 (2-3-1) 6% 3-BB(2F,3F)-O2
(2-4-1) 6% 5-BB(2F,3F)-O2 (2-4-1) 5% 2O-B(2F,3F)B(2F,3F)-O6 (2-5)
3% 2-HH1OB(2F,3F)-O2 (2-8-1) 10% 3-HH1OB(2F,3F)-O2 (2-8-1) 15%
2-HH-3 (3-1-1) 20% 3-HH-4 (3-1-1) 9% 3-HH-O1 (3-1) 5% 3-HB-O2 (3-2)
3% V2-BB-1 (3-3-1) 5% 3-HHB-1 (3-5-1) 3% 3-HHB-O1 (3-5) 3%
1-BB(F)B-2V (3-8-1) 3% 3-HHEBH-4 (3-9-1) 4%
[0140] Into 100 parts by weight of the composition, 0.15 part by
weight of compound (1-1-1-1) described below,
##STR00042##
and 0.15 part by weight of compound (1-2-1-1) described below were
added.
##STR00043##
NI=74.6.degree. C.; Tc<-20.degree. C.; .DELTA.n=0.090;
.DELTA..di-elect cons.=-3.3; Vth=2.20 V; .tau.=4.0 ms; VHR-1=99.3%;
VHR-2=98.0%.
Example 8
TABLE-US-00012 [0141] 3-H1OB(2F,3F)-O2 (2-3-1) 6% 3-BB(2F,3F)-O2
(2-4-1) 6% 5-BB(2F,3F)-O2 (2-4-1) 5% 2O-B(2F,3F)B(2F,3F)-O6 (2-5)
3% 2-HH1OB(2F,3F)-O2 (2-8-1) 10% 3-HH1OB(2F,3F)-O2 (2-8-1) 15%
2-HH-3 (3-1-1) 20% 3-HH-4 (3-1-1) 8% 3-HH-O1 (3-1) 5% 3-HB-O2 (3-2)
3% V2-BB-1 (3-3-1) 5% 3-HHB-1 (3-5-1) 3% 3-HHB-O1 (3-5) 4%
1-BB(F)B-2V (3-8-1) 3% 3-HHEBH-4 (3-9-1) 4%
[0142] Into 100 parts by weight of the composition, 0.3 part by
weight of compound (1-2-1-1) described below was added.
##STR00044##
NI=75.8.degree. C.; Tc<-20.degree. C.; .DELTA.n=0.091;
.DELTA..di-elect cons.=-3.3; Vth=2.21 V; .tau.=4.1 ms; VHR-1=99.3%;
VHR-2=97.9%.
[0143] The compositions according to Examples 1 to 8 have a shorter
response time in comparison with the composition according to
Comparative Example 1.
[0144] Although the invention has been described and illustrated
with a certain degree of particularity, it is understood that the
disclosure has been made only by way of example, and that numerous
changes in the conditions and order of steps can be resorted to by
those skilled in the art without departing from the spirit and
scope of the invention.
INDUSTRIAL APPLICABILITY
[0145] The invention concerns a liquid crystal composition
satisfying at least one of characteristics such as a high maximum
temperature of a nematic phase, a low minimum temperature of the
nematic phase, a small viscosity, a suitable optical anisotropy, a
large negative dielectric anisotropy, a large specific resistance,
a high stability to ultraviolet light and a high stability to heat,
or a liquid crystal composition having a suitable balance regarding
at least two of the characteristics is provided. A liquid crystal
display device containing such a liquid crystal composition is
applied to constitute an AM device having a short response time, a
large voltage holding ratio, a large contrast ratio, a long service
life and so forth, and thus can be used for a liquid crystal
projector, a liquid crystal television and so forth.
* * * * *