U.S. patent application number 12/399998 was filed with the patent office on 2010-05-27 for liquid crystal compounds and liquid crystal compositions comprising the same.
This patent application is currently assigned to INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE. Invention is credited to An-Cheng Chen, Kung-Lung Cheng, Peu-Jane Huang, Shih-Hsien Liu.
Application Number | 20100127210 12/399998 |
Document ID | / |
Family ID | 42124809 |
Filed Date | 2010-05-27 |
United States Patent
Application |
20100127210 |
Kind Code |
A1 |
Huang; Peu-Jane ; et
al. |
May 27, 2010 |
LIQUID CRYSTAL COMPOUNDS AND LIQUID CRYSTAL COMPOSITIONS COMPRISING
THE SAME
Abstract
A liquid crystal compound of Formula (I) is provided.
##STR00001## In Formula (I), Y1, Y2 and Y3 are, independently,
hydrogen, halogen, cyano or thiocyano, and R is C1-12 alkyl or
C1-12 alkoxy, preferably C3-6 alkyl. The liquid crystal compound is
colorless. The invention also provides a liquid crystal composition
including the liquid crystal compound.
Inventors: |
Huang; Peu-Jane; (Taipei,
TW) ; Chen; An-Cheng; (Hsinchu, TW) ; Cheng;
Kung-Lung; (Hsinchu, TW) ; Liu; Shih-Hsien;
(Jhubei City, TW) |
Correspondence
Address: |
PAI PATENT & TRADEMARK LAW FIRM
1001 FOURTH AVENUE, SUITE 3200
SEATTLE
WA
98154
US
|
Assignee: |
INDUSTRIAL TECHNOLOGY RESEARCH
INSTITUTE
Hsinchu County
TW
|
Family ID: |
42124809 |
Appl. No.: |
12/399998 |
Filed: |
March 9, 2009 |
Current U.S.
Class: |
252/299.61 ;
544/395 |
Current CPC
Class: |
C09K 2019/3075 20130101;
C09K 2019/3083 20130101; C09K 2019/3016 20130101; C07D 295/155
20130101; C09K 19/42 20130101; C09K 2019/3077 20130101; C07D
295/073 20130101; C09K 19/3483 20130101; C09K 19/3059 20130101 |
Class at
Publication: |
252/299.61 ;
544/395 |
International
Class: |
C09K 19/34 20060101
C09K019/34; C07D 295/14 20060101 C07D295/14; C07D 295/073 20060101
C07D295/073 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 25, 2008 |
TW |
097145463 |
Claims
1. A liquid crystal compound of Formula (I): ##STR00026## , wherein
Y.sub.1, Y.sub.2 and Y.sub.3 are, independently, hydrogen, halogen,
cyano or thiocyano; and R is C1-12 alkyl or C1-12 alkoxy.
2. The liquid crystal compound as claimed in claim 1, wherein R is
C3-6 alkyl.
3. The liquid crystal compound as claimed in claim 1, wherein
Y.sub.1 is fluorine, Y.sub.2 is cyano and Y.sub.3 is fluorine.
4. The liquid crystal compound as claimed in claim 3, wherein R is
C3-6 alkyl.
5. The liquid crystal compound as claimed in claim 1, wherein
Y.sub.1 is hydrogen, Y.sub.2 is cyano and Y.sub.3 is fluorine.
6. The liquid crystal compound as claimed in claim 5, wherein R is
C3-6 alkyl.
7. The liquid crystal compound as claimed in claim 1, wherein
Y.sub.1 is hydrogen, Y.sub.2 is cyano and Y.sub.3 is hydrogen.
8. The liquid crystal compound as claimed in claim 7, wherein R is
C3-6 alkyl.
9. The liquid crystal compound as claimed in claim 1, wherein
Y.sub.1 is fluorine, Y.sub.2 is fluorine and Y.sub.3 is
fluorine.
10. The liquid crystal compound as claimed in claim 9, wherein R is
C3-6 alkyl.
11. The liquid crystal compound as claimed in claim 1, wherein the
liquid crystal compound is colorless.
12. A liquid crystal composition, comprising: a first liquid
crystal compound of Formula (I) as claimed in claim 1; and a second
liquid crystal compound of Formulas (Z1)-(Z9): ##STR00027## wherein
R.sup.1 is C1-9 alkyl, B is halogen or cyano, and R.sup.2, R.sup.3
and R.sup.4 are, independently, a group that is formed by
substituting --CH.sub.2-- with --O-- or --CH.dbd.CH-- and
substituting at least one hydrogen with fluorine C1-10 alkyl and
R.sup.5 and R.sup.8 are, independently, a group that is formed by
substituting --CH.sub.2-- with --O-- C1-10 alkyl and R.sup.6,
R.sup.7 and R.sup.9 are, independently, C1-10 alkyl, (wherein at
least one hydrogen is replaced by fluorine) A1, A2, A3 and A5 are,
independently, trans-1,4-cyclohexylene or 1,4-phenylene, (wherein
at least one hydrogen is replaced by fluorine) and A4 is
1,4-phenylene (wherein at least one hydrogen is replaced by
fluorine), Z.sup.1 is ethylenyl or acetylenyl, m and n are 0-2, and
X.sup.3 is hydrogen or fluorine, wherein the first liquid crystal
compound and the second liquid crystal compound have a weight ratio
of 0.5:99.5-35:65.
13. The liquid crystal composition as claimed in claim 12, wherein
the first liquid crystal compound and the second liquid crystal
compound have a weight ratio of 5:95-10:90.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Application claims priority of Taiwan Patent
Application No. 97145463, filed on Nov. 25, 2008, the entirety of
which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a liquid crystal compound, and more
particularly to a liquid crystal compound containing
piperazine.
[0004] 2. Description of the Related Art
[0005] Liquid crystals possess dielectric and optical anisotropy,
superior molecule alignment and fluidity. When stimulated by light,
heat, of an electric field or magnetic field, molecule alignments
of liquid crystals are easily altered to form contrast or specific
optical effects. A display fabricated thereby possesses a light
weight, portability, fine size and low power consumption. Thus,
recently, liquid crystals have become a popular display medium for
various portable electric and information products, such as digital
watches, calculator and automotive instrument panels, twisted
nematic (TN) LCDs, super twisted nematic (STN) LCDs, notebook
computers, optical grating of components of projectors and memory
cells of printers.
[0006] An ideal liquid crystal material possesses superior chemical
properties, for example, a wide nematic liquid crystal phase, a low
melting point, low fusion heat, physicochemical stability and
achromatization, and simultaneously possess superior physical
properties, for example, high dielectric anisotropy
(.DELTA..epsilon.) and high birefringence (.DELTA.n)
properties.
BRIEF SUMMARY OF THE INVENTION
[0007] One embodiment of the invention provides a liquid crystal
compound of Formula (I):
##STR00002##
[0008] wherein
[0009] Y1, Y2 and Y3 are, independently, hydrogen, halogen, cyano
or thiocyano, and R is C1-12 alkyl or C1-12 alkoxy.
[0010] One embodiment of the invention provides a liquid crystal
composition comprising a first liquid crystal compound of Formula
(I) and a second liquid crystal compound of Formulas (Z1)-(Z9):
##STR00003## ##STR00004##
[0011] wherein
[0012] R.sup.1 is C1-9 alkyl, B is halogen or cyano, and R.sup.2,
R.sup.3 and R.sup.4 are, independently, C1-10 alkyl, wherein
methylene is replaced by oxygen or ethylenyl and at least one
hydrogen is replaced by fluorine, and R.sup.5 and R.sup.8 are,
independently, C1-10 alkyl, wherein methylene is replaced by
oxygen, and R.sup.6, R.sup.7 and R.sup.9 are, independently, C1-10
alkyl, A1, A2, A3 and A5 are, independently,
trans-1,4-cyclohexylene or 1,4-phenylene, and A4 is 1,4-phenylene,
wherein at least one hydrogen is replaced by fluorine, Z.sup.1 is
ethylenyl or acetylenyl, m and n are 0-2, and X.sup.3 is hydrogen
or fluorine, wherein the first liquid crystal compound and the
second liquid crystal compound have a weight ratio of
0.5:99.5-35:65.
[0013] Note that the chemical and photoelectric properties of the
modified liquid crystal molecule of the invention are improved,
thus facilitating application in various liquid crystal devices.
Additionally, the dipole moment of the liquid crystal compound with
a piperazine structure having rich electron pairs to induce
resonance is increased. Meanwhile, the dielectric anisotropy
(.DELTA..epsilon.) thereof is increased by production of an
electron withdrawing effect of the polar functional groups (Y1, Y2
and Y3). The birefringence (.DELTA.n) thereof is increased by
conduction into a benzene or triple bond to extend the conjugated
structure length of the main chain. Additionally, performance of a
display cannot be interfered with due to conduction into the
colorless polar functional groups (Y1, Y2 and Y3), for example,
halogen, cyano or thiocyano. When the liquid crystal composition
with large dipole moment, low viscosity and high dielectric
anisotropy is applied in TN LCDs, cholesterol LCDs or polymer
dispersed LCDs, the driving voltage thereof is reduced. In addition
to high dielectric anisotropy and high birefringence, the colorless
liquid crystal compound possesses high thermal stability and high
compatibility.
[0014] A detailed description is given in the following
embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The following description is of the best-contemplated mode
of carrying out the invention. This description is made for the
purpose of illustrating the general principles of the invention and
should not be taken in a limiting sense. The scope of the invention
is best determined by reference to the appended claims.
[0016] One embodiment of the invention provides a liquid crystal
compound of Formula (I):
##STR00005##
[0017] In Formula (I), Y1, Y2 and Y3 may be, independently,
hydrogen, halogen, cyano or thiocyano. R may be C1-12 alkyl, C1-12
alkoxy or C3-6 alkyl.
[0018] Specifically, the liquid crystal compound is colorless.
[0019] Specific liquid crystal compounds, for example, Formulas
(I-1)-(I-3) are disclosed in other embodiments:
##STR00006##
[0020] The dielectric anisotropy (.DELTA..epsilon.) of the liquid
crystal compound is about 18-35. The birefringence (.DELTA.n)
thereof is about 0.25-0.40. The liquid crystal compound can be
widely used in, for example, reflective-type cholesterol LCDs,
polymer dispersed LCDs, TN LCDs, STN LCDs, TFT LCDs or IPS
LCDs.
[0021] Note that the chemical and photoelectric properties of the
modified liquid crystal molecule of the invention are improved,
thus facilitating application in various liquid crystal devices.
Additionally, the dipole moment of the liquid crystal compound with
a piperazine structure having rich electron pairs to induce
resonance is increased. Meanwhile, the dielectric anisotropy
(.DELTA..epsilon.) thereof is increased by production of an
electron withdrawing effect of the polar functional groups (Y1, Y2
and Y3). The birefringence (.DELTA.n) thereof is increased by
conduction into a benzene or triple bond to extend the conjugated
structure length of the main chain. Additionally, performance of a
display cannot be interfered with due to conduction into the
colorless polar functional groups (Y1, Y2 and Y3), for example,
halogen, cyano or thiocyano. When the liquid crystal composition
with large dipole moment, low viscosity and high dielectric
anisotropy is applied in TN LCDs, cholesterol LCDs or polymer
dispersed LCDs, the driving voltage thereof is reduced. In addition
to high dielectric anisotropy and high birefringence, the colorless
liquid crystal compound possesses high thermal stability and high
compatibility.
[0022] One embodiment of the invention provides a liquid crystal
composition comprising a first liquid crystal compound of Formula
(I) and a second liquid crystal compound of Formulas (Z1)-(Z9):
##STR00007## ##STR00008##
[0023] In Formulas (Z1)-(Z9), R.sup.1 may be C1-9 alkyl. B may be
halogen or cyano. R.sup.2, R.sup.3 and R.sup.4 may be,
independently, C1-10 alkyl, wherein methylene may be replaced by
oxygen or ethylenyl and at least one hydrogen may be replaced by
fluorine. R.sup.5 and R.sup.8 may be, independently, C1-10 alkyl,
wherein methylene may be replaced by oxygen. R.sup.6, R.sup.7 and
R.sup.9 may be, independently, C1-10 alkyl. A1, A2, A3 and A5 may
be, independently, trans-1,4-cyclohexylene or, 1,4-phenylene. A4
may be 1,4-phenylene, wherein at least one hydrogen may be replaced
by fluorine. Z.sup.1 may be ethylenyl or acetylenyl. m and n may be
0-2. X.sup.3 may be hydrogen or fluorine.
[0024] The first and second liquid crystal compounds have a weight
ratio of about 0.5:99.5-35:65 or 5:95-10:90.
EXAMPLE 1
[0025] Preparation of the Formula (I-1) compound and dielectric
anisotropy (.DELTA..epsilon.) and birefringence (.DELTA.n)
thereof:
##STR00009##
[0026] Step 1:
##STR00010##
[0027] First, under nitrogen, 1 g of compound A (6.2 mmol), 0.9 g
of bromopentane (6 mmole), 1.38 g of potassium carbonate (10 mmol)
and 20 mL of dimethyl sulfoxide (DMSO) were added to a reaction
bottle and heated to 100-110.degree. C. with reflux for 16 hours.
After cooling, the resulting solution was repeatedly extracted with
saturated salt water and ethyl acetate until DMSO was removed.
After being dried by magnesium sulfate and concentrated, the crude
product was purified by column chromatography. A canary yellow
liquid compound M1 was obtained, with 90% of yield.
[0028] Step 2:
##STR00011##
[0029] First, under nitrogen, 1 g of compound M1 (4.2 mmol), 1.38 g
of n-bromosuccinimide (NBS) (10 mmol) and 10 mL of dichloromethane
were added to a reaction bottle and allowed to react at room
temperature for 16 hours. The resulting solution was then
repeatedly extracted with saturated salt water and ethyl acetate.
After being dried by magnesium sulfate and concentrated, the crude
product was purified by column chromatography. A canary yellow
liquid compound M2 was obtained, with 90% of yield.
[0030] Step 3:
##STR00012##
[0031] First, under nitrogen, 1 g of ethynyltrimethylsilane (10.2
mmol) and 10 mL of THF were added to a reaction bottle and cooled
to -78.degree. C. using liquid nitrogen and acetone. Next, 12 mL of
n-BuLi was added and allowed to react for 20 minutes. 2.4 g of zinc
chloride (18.3 mmol) dissolved in THF was then added to the
reaction bottle and continuously reacted for 20 minutes in the low
temperature state. After warming to 0.degree. C., 2.1 g of compound
M2 (10.2 mmol) and 0.3 g of tetrakis(triphenylphosphine) palladium
(0.3 mmol) dissolved in THF were added to the reaction bottle and
allowed to react at 60.degree. C. with reflux for 12 hours. The
reaction was terminated by adding NH.sub.4Cl. The resulting
solution was then repeatedly extracted with saturated salt water
and ethyl acetate. After being dried by magnesium sulfate and
concentrated, the crude product was purified by column
chromatography. A canary yellow solid compound M3 was obtained,
with 70% of yield.
[0032] Step 4:
##STR00013##
[0033] First, under nitrogen, 1 g of compound M3 (3 mmol), 10 mL of
methanol/dichloromethane (1/1) and 0.4 g of potassium carbonate
(4.5 mmol) were added to a reaction bottle and allowed to react at
room temperature for 12 hours. The resulting solution was then
repeatedly extracted with 20 mL of dichloromethane. After being
dried by magnesium sulfate and concentrated, the crude product was
purified by column chromatography. A canary yellow solid compound
M4 was obtained, with 75% of yield.
[0034] Step 5:
##STR00014##
[0035] First, under nitrogen, 1 g of compound M4 (3.9 mmol) and 5
mL of THF were added to a reaction bottle and cooled to -78.degree.
C. using liquid nitrogen and acetone. Next, 1.7 mL of n-BuLi was
added and allowed to react for 20 minutes. 0.9 g of zinc chloride
(7 mmol) dissolved in THF was then added to the reaction bottle and
continuously reacted for 20 minutes in the low temperature state.
After warming to 0.degree. C., 0.8g of 4-bromo-2-fluorobenzonitrile
(3.9 mmol) and 0.2 g of tetrakis(triphenylphosphine) palladium (0.2
mmol) dissolved in THF were added to the reaction bottle and
allowed to react at 60.degree. C. with reflux for 12 hours. The
reaction was terminated by adding NH.sub.4Cl. The resulting
solution was then repeatedly extracted with saturated salt water
and ethyl acetate. After being dried by magnesium sulfate and
concentrated, the crude product was purified by column
chromatography. A white solid compound I-1 was obtained, with 65%
of yield. The dielectric anisotropy (.DELTA..epsilon.) of compound
I-1 was 31.8. The birefringence (.DELTA.n) thereof was 0.3763. The
preparations of compound I-2 and compound I-3 were similar to that
of compound I-1. The distinction thereamong was merely different
reactants used in step 5. A person skilled in the art can simply
prepare compound I-2 and compound I-3 according to Example 1. The
dielectric anisotropy (.DELTA..epsilon.) of compound I-2 was 26.9.
The birefringence (.DELTA.n) of compound I-2 was 0.3206. The
dielectric anisotropy (.DELTA..epsilon.) of compound I-3 was 18.8.
The birefringence (.DELTA.n) of compound I-3 was 0.2685. Comparison
of the dielectric anisotropy (.DELTA..epsilon.) and the
birefringence (.DELTA.n) between compounds I-1-I-3 and conventional
liquid crystal molecules with similar structures is shown in Table
1.
TABLE-US-00001 TABLE 1 Dielectric Bire- anisotropy fringence
(.DELTA..epsilon.) (.DELTA.n) Compound I-1 31.8 0.3763 Compound I-2
26.9 0.3206 Compound I-3 18.8 0.2685 ##STR00015## 19.8 0.146
##STR00016## 15.4 0.119 ##STR00017## 16.7 0.2
[0036] The results indicated that the dielectric anisotropy
(.DELTA..epsilon.) of compounds I-1-I-3 was higher than that of the
conventional liquid crystal molecules due to conduction into a
piperazine group having rich unshared electron pairs capable of
inducing resonance to increase molecule dipole moment. Also, the
birefringence (.DELTA.n) of compounds I-1-I-3 was apparently higher
than that of the conventional liquid crystal molecules due to
conduction into a triple bond to extend the conjugated structure
length of the liquid crystal molecule main chain.
EXAMPLE 2
[0037] Preparation of the liquid crystal composition (1) and
dielectric anisotropy (.DELTA..epsilon.) and birefringence
(.DELTA.n) thereof:
[0038] Compound I-1 and a liquid crystal mixture (YY066-042) were
mixed with a ratio of 5:95 to form a liquid crystal composition.
The liquid crystal mixture (YY066-042) comprised 8% of 5HBBCN,
24.1% of 5HBCN, 7.7% of 5HBEBFCN, 13.5% of 5HBF, 7% of 2HEBFCN,
6.5% of 3HHEBF, 3.5% of 5HHEBF, 1.7% of 2BBCN, 4.9% of 3HEBBCN,
15.4% of 5BEBFCN and 7.7% of 3HBEBFCN. The dielectric anisotropy
(.DELTA..epsilon.) of the liquid crystal mixture (YY066-042) was
17.3. The birefringence (.DELTA.n) thereof was 0.1355. The driving
voltage of the device formed by the liquid crystal mixture
(YY066-042) was 1.043V. After adding compound I-1, the dielectric
anisotropy (.DELTA..epsilon.) of the liquid crystal composition
increased to 18.1. The birefringence (.DELTA.n) thereof increased
to 0.1475. The driving voltage of the device formed by the liquid
crystal mixture (YY066-042) and Compound I-1 was reduced to 1.023V.
Note that for each component of the liquid crystal mixture
(YY066-042), each code name was corresponded to various chemical
formulas, for example, code name 2 represents C.sub.2H.sub.5--,
code name 3 represents C.sub.3H.sub.7--, code name 5 represents
C.sub.5H.sub.11--, code name H represents
##STR00018##
code name B represents
##STR00019##
code name CN represents CN, code name E represents --COO--, and
code name F represents --F.
EXAMPLE 3
[0039] Preparation of the liquid crystal composition (2) and
dielectric anisotropy (.DELTA..epsilon.) and birefringence
(.DELTA.n) thereof:
[0040] Compound I-2 and a liquid crystal mixture (DH0381-110) were
mixed with a ratio of 5:95 to form a liquid crystal composition.
The liquid crystal mixture (DH0381-110) comprised 10.3% of 5HBBCN,
7.2% of 3HBO2, 12.6% of 2BBCN, 31.9% of 5BBCN, 10% of 3HEBBCN,
21.8% of 7BBCN and 6.2% of 5BEBBCN. The dielectric anisotropy
(.DELTA..epsilon.) of the liquid crystal mixture (DH0381-110) was
13.49. The birefringence (.DELTA.n) thereof was 0.0987. The driving
voltage of the device formed by the liquid crystal mixture
(DH0381-110) was 1.862V. After adding compound I-2, the dielectric
anisotropy (.DELTA..epsilon.) of the liquid crystal composition
increased to 14.27. The birefringence (.DELTA.n) thereof increased
to 0.1112. The driving voltage of the device formed by the liquid
crystal mixture (DH0381-110) and Compound I-2 was reduced to
1.434V. Note that for each component of the liquid crystal mixture
(DH0381-110), each code name was corresponded to various chemical
formulas, for example, code name 2 represents C.sub.2H.sub.5--,
code name 3 represents C.sub.3H.sub.7--, code name 5 represents
C.sub.5H.sub.11--, code name 7 represents C.sub.7H.sub.15--, code
name H represents
##STR00020##
code name B represents
##STR00021##
code name CN represents CN, code name F represents --F, code name O
represents --O--, and code name E represents --COO--.
EXAMPLE 4
[0041] Preparation of the liquid crystal composition (3) and
dielectric anisotropy (.DELTA..epsilon.) and birefringence
(.DELTA.n) thereof:
[0042] Compound I-3 and a liquid crystal mixture (LOT3) were mixed
with a ratio of 10:90 to form a liquid crystal composition. The
liquid crystal mixture (LOT3) comprised 2.5% of 5HBF, 2.5% of 6HBF,
2.5% of 7HBF, 9.6% of 3HHB(F)F, 2.5% of 3HBEB(FF)F, 2% of
4HBEB(FF)F, 6.2% of 3HHEB(FF)F, 4.9% of 3HHB(FF)F, 9.6% of
3HBB(FF)F, 9.7% of 5HBB(FF)F, 5.2% of 4HHB(FF)F, 4.5% of 5HHB(FF)F,
9.9% of 3HHV, 4.7% of 3HBB(F)F, 9.8% of 3HH2B(F)F, 9.1% 1BHHV and
4.8% of 2BB(F)B3. The dielectric anisotropy (.DELTA..epsilon.) of
the liquid crystal mixture (LOT3) was 7.38. The birefringence
(.DELTA.n) thereof was 0.0987. The driving voltage of the device
formed by the liquid crystal mixture (LOT3) was 1.862V. After
adding compound I-3, the dielectric anisotropy (.DELTA..epsilon.)
of the liquid crystal composition increased to 8.545. The
birefringence (.DELTA.n) thereof increased to 0.1158. The driving
voltage of the device formed by the liquid crystal mixture (LOT3)
and Compound I-3 was reduced to 1.802V. Note that for each
component of the liquid crystal mixture (LOT3), each code name was
corresponded to various chemical formulas, for example, code name 1
represents CH.sub.3--, code name 3 represents C.sub.3H.sub.7--,
code name 4 represents C.sub.4H.sub.9--, code name 5 represents
C.sub.5H.sub.11--, code name 6 represents C.sub.6H.sub.13--, code
name 7 represents C.sub.7H.sub.15--, code name H represents
##STR00022##
code name B represents
##STR00023##
code name B(F) represents
##STR00024##
code name B(FF) represents
##STR00025##
code name F represents --F, code name E represents --COO--, and
code name V represents CH.sub.2.dbd.CH--.
[0043] While the invention has been described by way of example and
in terms of preferred embodiment, it is to be understood that the
invention is not limited thereto. To the contrary, it is intended
to cover various modifications and similar arrangements (as would
be apparent to those skilled in the art). Therefore, the scope of
the appended claims should be accorded the broadest interpretation
so as to encompass all such modifications and similar
arrangements.
* * * * *