JPH02242882A - Ferroelectric liquid crystal composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having excellent responsiveness, memorizing property, etc., and suitable for liquid crystal display elements by adding a specific optically active compound as a chiral dopant to an optically inert liquid crystal composition exhibiting a smectic C phase. CONSTITUTION:The objective composition obtained by adding (B) an optically active compound expressed by formula I (R<1> and R<2> are 2-10C alkyl, etc.; X is a group expressed by formula II, etc.; Z<a> is -O-, etc.) as a chiral dopant to (A) a liquid crystal composition, exhibiting a smectic C phase and containing (i) a matrix liquid crystal within a medium temperature region consisting of an optically inert liquid crystal compound (homolog) with a bicyclic structure and exhibiting a smectic C phase which can be monotropic and a liquid crystal compound (homolog) with a tricyclic structure including cyclohexyl ring and exhibiting the smectic C phase and (ii) a liquid crystal compound within a high temperature region, containing a liquid crystal (homolog) with a tri- or polycyclic structure and exhibiting the smectic C phase.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a novel liquid crystal composition useful as an electro-optical display material, and in particular provides a liquid crystal material having ferroelectricity, which is different from conventional liquid crystal compositions. The object of the present invention is to provide a liquid crystal material that has particularly excellent responsiveness and memory performance compared to liquid crystal materials, and can be used for liquid crystal display elements.

[Prior Art] Currently, the liquid crystal display elements that are widely used are mainly of the TN type, which utilizes nematic liquid crystals, and although they have many advantages, their responsiveness is inferior to that of CRTs, etc. The major drawback was that it was much slower than the light-emitting display method. Many liquid crystal display systems other than the TN type have been studied, but improvements in their responsiveness have not yet been achieved.

However, in liquid crystal devices using ferroelectric smectic liquid crystals, the 100 to 10
It has recently been revealed that because it is capable of a 00 times faster response and has multistability, it can retain the display even when the power is turned off (memory effect). For this reason, it has great potential to be used in optical shutters, printer heads, flat-screen televisions, etc., and research and development is currently being conducted in various fields to put it into practical use.

The liquid crystal phase of the ferroelectric liquid crystal belongs to the tilted chiral smectic phase, and among these, the one that is practically desirable is the chiral smectic C (hereinafter abbreviated as S01) phase, which has the lowest viscosity. It is called.

[Problem to be solved by the invention]

Liquid crystal compounds exhibiting the SC' phase (hereinafter referred to as SC1 compounds) have been studied, and many compounds have already been synthesized. However, these S0
One compound alone must meet the following conditions for use as an optical switching element for ferroelectric liquid crystal displays: (a) exhibiting ferroelectricity over a wide temperature range including room temperature; and (b) having appropriate phase stability in a high temperature range. Having a series (c) Particularly chiral nematic (hereinafter abbreviated as N1).

) exhibiting a long helical pitch in the phase; (d) having an appropriate tilt angle; (e) having low viscosity; (f) having a large value of spontaneous polarization above a certain level. No material has been known that satisfies all of (1), (5), (e), and (f), which include good orientation as a result of (1), and high-speed response as a result of (f).

Therefore, the current situation is that liquid crystal compositions exhibiting the S00 phase (hereinafter referred to as S00 liquid crystal compositions) are used for study purposes and the like.

In order to obtain good orientation, for example, JP-A-61-1
As shown in Japanese Patent No. 53623 and the like, in a liquid crystal having an N1 phase in the high temperature range of the SC0 phase, a method of increasing the helical pitch length of the N1 phase is generally effective. In this case, it is better to have a smectic A (hereinafter abbreviated as SA) phase in the temperature range between the 5C1T phase and the N1 phase, and to increase the helical pitch, a left-handed helix is generated. It is also known that an optically active substance and an optically active compound that causes right-handed helix may be used in combination. (It is already a known technique to adjust the helical pitch to an arbitrary length by adding an optically active substance to a nematic (abbreviated as N) liquid crystal.) However, some of these techniques do not provide good results. Although orientation can be obtained,
High-speed response could not be obtained.

In order to exhibit high-speed responsiveness, for example, low viscosity smectic C (hereinafter abbreviated as SC) is used, as shown in the special lecture at the 12th Liquid Crystal Conference (Proceedings of the same conference P, 98). ) phase (hereinafter referred to as SC matrix liquid crystal) has a spontaneous polarization (hereinafter abbreviated as Ps).

) is better.

According to this method, the proportion of the optically active compound that generates the helix decreases, so the helical pitch becomes relatively long. It is necessary to reduce the amount of ions, which causes the problem that the spontaneous polarization becomes too small, making it impossible to obtain high-speed response.

Furthermore, those that have been used hitherto as SC matrix liquid crystals are described in, for example, Japan Display 86 Lecture Proceedings (from page 352) or Japanese Patent Application Laid-open No. 1983-583.

(R, R' represent an achiral alkyl group.) (R,
R' is the same as above. ), the compound itself or its homologues are limited to those exhibiting an SC phase, or compositions in which a liquid crystal compound is added that exhibits a strong dipole (polarization) in the direction perpendicular to the long axis of the molecule. However, if the temperature range of the SC phase is kept wide, the viscosity increases, and if the viscosity is decreased, the temperature range of the SC phase becomes narrow.

Therefore, with the prior art, it has been difficult to simultaneously achieve good orientation and high-speed response.

The problem to be solved by the present invention is to provide a ferroelectric liquid crystal composition that is fully satisfactory in both high-speed response and orientation.

[Means to solve the problem]

...(A) An S, 'E' liquid crystal composition exhibiting an SC' phase in a wide temperature range including room temperature, which is obtained by adding a chiral dopant containing at least one optically active compound represented by (A) as a constituent component. I will provide a.

- In Saijin (A,), R1 represents an alkyl group or alkoxy group having 2 to 10 carbon atoms, and R2 represents an alkyl group having 1 to 10 carbon atoms or an optically active alkyl group having 4 to 10 carbon atoms. where l represents an integer from 0 to 10. Z S is -o---co.

Represents 0CO- or a single bond. C* and C- each independently represent an asymmetric carbon atom of the (R) configuration or (S) configuration. X may be represented by the general formula (B), -Sailor (A), General formula (C), or -Sailor (D). Yl represents a fluorine atom, a chlorine atom, a cyano group, a methyl group, or a methoxy group, and Zz2 represents Z
ff is each independently a single bond, -COO-0CO--CH
zO0C1b CHzC)tz=]1 -5-C- or -CH=Cll-, Z4 is -C
1l□ - represents a 5-membered or 6-membered hydrocarbon ring, and any 1 to 2 -Cl- of Y' in the ring may be substituted with -N- or -〇-, Also, any 1 or 2 − in the ring
CH,- is -0--S--Nll--CI! -C--
5-1 or -kano-, m and n each independently represent O
Or represents 1. ) represents the central skeleton (core) part of a liquid crystal molecule.

Particularly preferably, in -Sailor (A), X is of the general formula (
E) (C) Although it has a phase series of ■ phase → N phase → SC phase, it vertically represents a hydrogen atom, a fluorine atom, a chlorine atom, or a cyano group, but Y2 and Y3 do not represent a hydrogen atom at the same time. Z
l, 7. Z and m represent the same as above. ) is a compound represented by

The SC base liquid crystal used in the present invention has (a)! on the high temperature side of its SC phase when the temperature decreases. (Isotropic liquid) A liquid that has a phase sequence of -→N phase→SA phase→SC phase (b) A liquid that has a phase series of ■ phase → SA phase → SC phase, or (d) A liquid that has a phase sequence of ■ phase → SC phase Among those having a phase series, those having any one of the phase series are used, and the selection of (a) to (d) differs depending on the chiral dopant used at the same time. The most commonly used is (a), which is the nematic property of chiral dopant (when added to the SC matrix liquid crystal, it tends to widen the temperature range of the N9 phase and narrow the temperature range of the SA phase). ) is strong, (b) is added to the smectic A property of the chiral dopant (when added to the SC matrix liquid crystal, it widens the temperature range of the SA phase and narrows the temperature range of the N″′ phase (
It is most suitable to use (c) when the temperature range of the N''' phase and SA phase is easy to expand. What is important is the phase sequence in the case of an SC1 liquid crystal composition, and for boat fishing, the phase sequence of 1→N1→SA−+SC'' is advantageous in terms of orientation. On the other hand, the phase series of ■→N1→S01 may also show better orientation depending on the dosage control method, and a large tilt angle can be easily obtained, so it is suitable for the guest-host system.

As the SC base liquid crystal used in the present invention, a composition consisting of a compound exhibiting an SC phase as conventionally used can be used, but in order to obtain faster response, the composition shown below can be used. is more preferable.

That is, it is mainly a two-ring structure, and SC at a temperature close to room temperature.
In order to increase the upper limit temperature of the SC phase, a composition consisting of a compound exhibiting a phase or its homologue (compounds that differ only in alkyl chains) (hereinafter referred to as a medium-temperature range parent liquid crystal) has a TC point (SC phase or SC phase). This is a composition made by adding a composition (hereinafter referred to as high-temperature liquid crystal) consisting of a compound having a high temperature (representing the upper limit temperature of the ``'' phase) and having a ring structure of three or more rings or a homologue thereof.

The medium-temperature range host liquid crystal referred to here means that the liquid crystal compound constituting it is optically inactive and has a two- or three-ring structure, and in the case of a three-ring structure, at least one ring is a cyclohexyl ring. and consists of a compound exhibiting an SC phase or a homologue that differs only in the number of carbon atoms and shape of its alkyl chain, and at least one compound among the homologs exhibits an SC phase at any temperature of 1°C or higher at 10°C or higher. It is a compound that exhibits an SC phase that may be monotropic in the temperature range of . However, in the case of a three-ring structure, it is a liquid crystal whose temperature is less than 90'C above the SC phase, and it is a liquid crystal whose temperature is less than 90'C.
It shows an SC phase which may be monotropic at the above temperature.

Typical compounds used as medium-temperature host liquid crystals are listed below. However, 2. In the general formula shown below, R, and R2 each independently represent an alkyl group having 1 to 8 carbon atoms.

of (I a) a-7) RlOqORl (I-a-9) R9 + crying OR.

N (1-a-10) R10 (Defense 4 Hino Fi.

-N (■ a-11) R, OP Kunsae deception OR.

-N (I R, 0 reptile OR.

-N (■ b) (1-b-31) (1-b-32) (1-b-33) (1-b-34) (f-b-35) (1-b-36) ocoai cooya teru R2 R, ocoo+cooJ defense R2 R,0COO yo filter coo (c-kun R2 p, ocoo(伽C00(defenseOf?.

R,0COO+coo((odeOR.

! ? , 0C00-■-000 (proof O11゜(I-b-
37) R10 tatami 000 (tears 0 COORZ (1-c-22) RICOO-(5) coO-<'5', -C00R2ρ (I -c-24) R,0CO(トCOO-乍'';7-CO0Rz( 1-c
-25) R, O ((Na coo → evil ← OR.

-N (I-c-27) -OR of RrCOO+ COO-.

-N (I d) (■ c-53) R10 (←oo(TOOR2 ρ (1-c-55) R,0 child C00 (XOCORt (I c-57) (1-c-58) RICOO+COO-@ -Rz R+C0O-o-C00(t0Rt (■ c-60) R,C00+COO(XOCORt (1-e) (1-e4) (1-e-2) Among the above compounds, as a medium temperature range host liquid crystal, , formula (1
-a) and the compound represented by the formula (1-b) are preferred, and the compounds represented by the formula (1-a-1), 2 (1=a2), and the formula (1-a-5
), formula (1-a-41),.

Particularly preferred are compounds represented by formulas (I-a-42) and 2N-b-1).

The high-temperature liquid crystal referred to here refers to an optically inactive compound that is mainly composed of three or more rings and exhibits an SC phase, its homologue, or a composition composed of these. Compounds that exhibit a SC phase have an upper limit temperature of 90°C or higher and exhibit a ζSC phase in a temperature range of at least 5°C or higher, and their homologs have an upper limit temperature of 90°C. The temperature range may be less than 5 degrees, or the SC phase may be monotropic, and the composition may have an upper limit temperature of 90 degrees Celsius or less. 4 at least 5
It exhibits an SC phase in a temperature range of at least 30°F.

Typical compounds used as high-temperature liquid crystals are listed below. However, in the general formula shown below, R,,R
, each independently represents an alkyl group having 1 to .18 carbon atoms.

of / / (■ a) (II[-a R,0be≧U〉(Pride OR.

(■ a-12) R, 0be3u〉(total ΣΣ〈kuto opz(Itl-a-
13) (III-a-14) ... ΦZ vine prevention... RU Y Sawakyoku... <m-a (Ill-a-16) ... ΦZ Sawa (ha)... RIΦshi (r 4oR.

(III-b) (III-c) (■ d) (II[-d ・(Kizawa moxibustion... (■ d-10) (■ d-11) R, 0ba3=tsuday6=wa8zumenε>R.

R, OΦ abusive bracken R2 (■ R10-f■◎0h (II!-e) (■ C) <rli-f R5 (Baa coo■0COR.

(1-f R,O elephant Me■COO-@-RZ R,COO(X C00GOR2 R1(〆stopcoo(shiC00R2 R(prevention □□□coo cloudy COOR2 (III-g) (■ h) (II[-i) (■ j) (■ k) (■ Compounds having the following heterocycles can also be used as high-temperature liquid crystals. In addition, in the compounds having the heterocycles shown in the general formulas below, fluorine atoms and chlorine atoms are added to the benzene ring and cyclohexane ring. Compounds substituted with atoms or cyano groups can also be used as high temperature liquid crystals.

of (ffil) (III-m-9) (■-110) (In-m-11) (I[l-01-12) (I[[-m-13) (1-m-14) (III-n+-15) (m-ys-16) R10(1COO()-R2 R, 0℃ h noise C00<　0R2 R1(compromiseC00()ocoR2 R,COO℃＼GoC00(i2 R1℃ 5;’pcoo ((feather R2 R1 (ha possible-coo+oR- R10℃ embryonic coo ((feather R2 R, OΦX be coo (feather OR.

(In-m-41) ((II-m-42) (Ill　-m-43) (III-m-44) ([1I-n+-45) (In-m-46) (III-m-47) (■-barrel-48) R1 Yabo DCoo4) OcORt RICOO(0〆Dcoo-@-R.

幀p)<DCoo()R2 R1 I no one @-COO-@-0R2 R,0('β-@-coo3p.

R10RD()C00()oR2 R1(,k　C00(feather0COR.

R, COOi no one @-coo-@-R.

(ill -m-73) (Iil-i-74) (Ill-m-75) (III-n+-76) (III-+5-77) (III-m-78) (III-m-79) ( III-a-80) e (' a, coo QnR2R,% coo
Heart > OR.

R, 0°C + coo(o')-R.

RrOn COO Shin)-op.

R, m coo 挺', -ocoR2 RICOOΦX 悴coo bag YR2 plecoo-<p)p2 R1(xdarkCOO-<p)OP2 (■ n) (III-n-29) (Ill　-n-30) (in-31) (III-n-32) (III-n-33) (III-n-34) (■~n-35) CI [l-n-36) R(N7oco-◎0COR□ RICOO (3) R() trust ocoya~P2 RI(Heibo0CO()ORt RlO R10 (Dofu 0CO-C←R7 R1-@r4Tuesday0CO()OCOR2 RICOO(3)X Bo coco()R2 (III-n-61) (III-n-62) (III-n-63) (III-n-64) (■-Low 65) (I[l-n-66) (III-n-67) (Iff-n-68) 1? , Tube) Qoco-@-p.

R1 ancestor H (ha) OCou 0R2 R, Oso R moxibustion coco (Chi 2 R, 0 ancestor moxibustion OCO + 0Rz R1 ancestor moxibustion coco-■0COR2 R+COO ancestor □□□oco-@-1? .

Collar 0CO on R1 (Ken R2 ◎-0-OCO-◎OR2 (m-n-93) (III-n-94) (III-n-95) (Ill-n-96) (III-n-97) (1-n-98) (III-n-99) (In-n-100) R50#0CO-@-R.

R, oe oco + 0RZ L% OCOi OCO"2 RICOO% oco +Rz R1>OCO+"- R, ya 18) (]ILo-19) (III-o-20) (III-o-21) (Ill-o-22) (III-o-23) (I[[-o-24) R, bag figure 5 ')-cH-o-4 10COt? zR1C
OO2\cHzol lh R1Φ , coo(
Feather (Toyama 0 Gold R2 ([1-o-49) (I[I -o-50) (III -o-51) (IIT-o-52) (III-o-53) (III -o- 54) (III-o-55) (III-o-56) R1 (strong◎CH, O+Rz R1 and ugly (9) ClhO combination OR.

・--N RIOnC”-Q-@-R- ...挺ん■
Moxibustion CH203RZ SuX (Defense R, CIl□OR.

↓X or () R+ CLOORg([1-o-
8L) ([1-o-82) (Ill -o-83) (III-o-84) (In -o-85) (I[I-o-86) (m-o-87) (III- o-88) R,o ((wings (wings C1+, mosquito 9 tribute 2 R10(HDcu2o(p>OR.

R+ (x staff C1120<p)OCORzp, coo<
leshi(shiyama0-(ρΣR2R1-@-ec"=0◎R
2 RI$ CIh0e O'12 -N R,06hcn2o◎R2 i'r,o-CpeJ c++□o-f5;',-0R2
L, N (III-p-5) (III-p-6) (III-p-7) (III-p-8) (III-p-9) (ffl-p-10) (III-p- 11) (I[-p-12) R()◇ε0CHzD 0CORz R,COO熢)■εoa11. GR2 Rt arrogance prevention QC) 1. <3shiR2 R1 (Oki>oc)12-@-of? .

R1 ← prevention, Q) oCIKG R2 R, 0 (3) H, 0) OCH"@-0R-R1 ya h) O
CH2-@-0COR2 RICOOJ@S 0CII DR2 (III-p-69) (III-p-70) (III-p-72) (■-p-72) <llll-p-73) (IllI, p-74) (I[[-p-75) (III-p-76) R,0-◎()oCH! G Rz R, 0 practice to Kin0C1j□combined OR.

R, Nubahei 0CII□■0COR2 R,C00k旙OC1＋□−＠４ R, -C vine -0C (1□Φgo R1@-@-0C11□<57OR.

R30@■ocl+4R2 R, 0<(every manager>o mountain (φN)-OR2(■-ρ-,
101) (DI -p-102) (■-ρ-103) (!ll-p-104) (I[[-p-105) (III-p406) (III-p-107) ([l-p -108) R, luck 80C)I glance),')-ocop.

R,COO℃+OCH,+Rt R0 furnace %3 oCH, (←R7 R1(Bahe10C(1□shaOR.

R10 Bag x Moxibustion 0CH2 Ya-R2 RIOte Docu2e Chi Oh -] R4-◇+0C) I4 Defense 0COR2 RICOO% OCRbe) R2 (III-q-25) (I[I-q-26) (H[- q-27) (III-q-28) (III-q-29) (III-q-30) R1% CtbCHx8"t 21℃4cFltC)!!<OR1 "IO<IH\5CHxclIbe◇-R7R,0 $C
tlxc! It%OR.

R1()Qcntcut(ツ0CORtRICOO9C
HzCtbe R1 (II[-q-57) (III -q-58) (III-q-59) (01-q-60) (III -q-61) (III -q-62) (m -q- 63) (III -q-64) Old X possible --〇- R,OC1l□CIl, l? 2 mourning bar■
Combined Rho CLClh
ORz↓X moxibustion (anti-RI CHzCIIz
0COR2coo Nava ■ () RI C112C112R
4P + (Shigushiyama C1l□8R2 R, Sobe(ha) CII2CH28011ZR, 0soba moxibustion cthcu□(and-R2 R, 0soba(Ha) C1l□CH()OR2(■~q-8
9) (III -q-90) (II -q-91) (III -q-92) (III -q-93) (I[[-q-94) (II[-q-95) (III - q-96) R1$CH2Cl12-@-0CORZR,COO℃+
cII2CHz<O> R2R1I CIIZCHbe5
? R- R, $ cH2CHz6 OR.

R,0℃h',-CH□C)ItkaiP2R,o((HagushiCH□YamakaiOR.

R1q CH2C'h-@-0CORzR, COO℃+
co2co-@-R= In the SC base liquid crystal of the present invention, if the proportion of the above-mentioned high-temperature liquid crystal is too large, the temperature range of the SC phase will expand to a high temperature range, but the viscosity will increase and have a negative effect on the response; Since the temperature range of the SC phase becomes narrower in
Particularly preferred is 50% by weight.

In this way, the SC phase has a wide temperature range and low viscosity.
C matrix liquid crystal can be obtained. By adding a chiral dopant to this, it is possible to easily achieve high-speed responsive SC1.
A liquid crystal composition can be obtained.

The chiral dopant used in the present invention includes (1) S
A compound exhibiting a C" phase, (2) a compound exhibiting only a liquid crystal phase other than the SC" phase, or (3) a compound exhibiting no liquid crystallinity at all can be used; however, in the case of (3), the SC matrix In order to prevent the tendency for the liquid crystallinity of the sc" liquid crystal composition obtained by adding it to liquid crystal to decrease, it is preferable to use a compound having a skeleton similar to that of liquid crystal.

The important physical properties that the chiral dopant brings to the S00 liquid crystal composition are the helical pitch it induces, the direction and magnitude of spontaneous polarization, and these depend on the optical activity of each compound constituting the chiral dopant. It is most affected by the body part.

Typical optically active groups in optically active compounds that have been used as chiral dopants, SC2 compounds, or additives to nematic liquid crystals are listed below.

CH.

(IV 1) + CHz +-CI(Cz
! 1s (IV-2) CHo 0+ CH2+-C1l-CzHs (IV-3) CH3 + CHx+VO+ CHz -)-ii-CHC2H
3(rV-4) CH3 -0(-CFlz+V-0-(-CL -h-C[I
CzHs(IV-12) C1+.

CHR4 (TV-13) CH3 -CHz Chi CH2'0Rs (IV-14) CH3 -CI-CI□-OR.

(1v-sonoshi-UtL;lIz+-cHR3(IV-1'
) No (,Ll に 1t2L; tlz-Lit-t, 1I
zuJL, Jull-1, fitCB.

C) l-11111zGHzcH l13 (IV-18) 0-C1hCH2 C-CH:1 (IV-32) -0-CHRa in CH3 1 (IV-21) CH3 -S + C1(, ±, Ctl(C)Iz )-CH3
(IV-43) 10-shishire υhs (IV-53) CH3 (・ CH-0-R5 (IV-55) OCH2CHRs (IV-62) h -o-CI-R5 (IV-64) CI3 0 C11z CI CfLz 0RsCH.

OCRCH20R5 (IV-66) CH3 -O+ GHz-+-T-CH (CHz)ii-0R5
(IV-57) l1 O-CHt C1l Rs (IV-61) -shi10-shii-ni5 (TV-69) -CO0CIb CHRs (IV-71) CI+3 0 CH-Cfh OCOR5 (IV-72) HI OCHC)It(CHz)r 0CORs(IV-73
) lh OCL-(al 4Ctlzhr CO[lS(IV-
76) C11°S CHRs Cl13 CH3 (IV-80) -C00CII□-CH-R5 (■ 10N Cl12- CI -R.

(■-82) N -C) I-R.

(■ O0 H2CN C)1. -C1l-R.

(IV-84) C) 12cN --0-CI(□-C)I-Ill.

In each of the above-mentioned shipmen, m represents an integer from 1 to 4, and n
is 1. - represents an integer of 10, where 1-3 represents the number of carbon atoms from 3 to
R4 represents an alkyl group having 2 to 10 carbon atoms, P represents an alkyl group having 1 to 10 carbon atoms, and R7 represents an alkyl group having 1 to 4 carbon atoms.

An optically active compound containing only optically active groups represented by 2 (rV-1) to (iV-22) is induced when added to an SC base liquid crystal to form an sc'' liquid crystal composition. The spontaneous polarization is very small, and even when the SC phase is exhibited alone, most of it is only 10 nC/cm or less.

On the other hand, as an optically active group, 1, formula (IV-31,) ~ (■
The optically active compound containing the optically active group represented by 91) induces a large spontaneous polarization when added to the SC base liquid crystal to form an SC° liquid crystal composition, and when it exhibits the SC″′ phase alone, it Some exhibit large values of 300 nC/c+++'' or more.

In particular, 2 (IV-45), formula (IV-46) and formula (
A compound having an optically active group represented by the formula (IV-45) is capable of inducing large spontaneous polarization.
), formula (IV-46) or formula (IV-47), other optically active groups include formula (IV-1), formula (■-2
), Formula (IV-5) to Formula (IV-12), Formula (IV-
15), formula (■-16), formula (IV-19), formula (r
V-20), 2 (IV-31) to 2 (TV-33),
Formula (IV-43), Formula (IV-53), Formula (IV-
74) and formula (IV-75) etc. General formula R' C) I fCH2) Ti'''- (wherein,
A compound having a plurality of optically active groups selected from the optically active groups represented by R', ffi, Z'' represents the same as -Funenin (A)) is used as a component of the chiral dopant. This is one of its characteristics.

2 (TV-1>, formula (IV-2), formula (IV-5) ~
Formula (IV-12), Ni (IV-15), Formula (I'v
The spontaneous polarization derived from the optically active groups represented by 'i6), formula (■-19) and formula (■-20) is
), are very small compared to those derived from the optically active groups represented by formulas (IV-46) and 2 (IV-47), so when considering combinations, only the direction of the helical pitch needs to be considered.

Formula (IV-31) to formula (IV-33), formula (IV-43
), formula (IV-53), 2 (■-74) and formula (IV
-75) etc., it is desirable to align the directions of their spontaneous polarization,
If they are contradictory, the spontaneous polarization of the compound may become very small.

Typical basic skeletons (X in -Funenin (A)) of optically active compounds having such an optically active group at the end are listed below.

(V-24) ■)-c=c-00oco-@ (V-48) ℃HSI) (V-96) 10FW...-Bone (V-120) Min...4t〈: Now (V-144) ◇) oco -0 Beshu (V-168) *X...-C0 (V-192) mate + oco () (V -240) ■ Iki... () (V ya) CH□0 Sobuki Itoji (V soOCH, Yatome, N (V (いCO Kyo(V Go CH□O Kyou) (■ (いCH, 赫(V 0C00＾included (V-484) sha oco ＾人(V (E>-CH20赫(V 〈)0山ヱえSOBE (V-508) (filter■-...挾〆, (■ Bag 癄BE發oco赫C~ (V-511) Yaba 0CI (Soot N Among the above, the basic skeletons represented by formulas (V-1) to (V-274) and their benzene [.

is preferably substituted with fluorine, and the formula (V-1 to formula (
V-3), formula (V-7) to formula (V-9), formula (V-17
), (V-18), the basic skeletons represented by formulas (V-21), (V-22), or formulas (V-25) to (V-274) are particularly preferred.

Specifically, for example, the following compounds can be mentioned.

It is also possible to use basic skeletons in which the benzene ring of each of the above basic skeletons is substituted with a fluorine atom, a salt, an elementary atom, a bromine atom, a methyl group, a methoxy group, a cyano group, or a nitro group. In particular, basic skeletons substituted with fluorine atoms are often preferred. Also,
Among the basic skeletons listed above, for those that are asymmetrical,
Those with the right and left sides reversed can also be used in the same way.

In the above, C is a crystalline phase, N1 is a chiral nematic phase, and SA
represents a smectic A phase, and S8 represents a smectic phase of unknown origin.

The advantages of using the compound represented by the above general formula (A) as a constituent component of a chiral dopant can be listed below.

(1) It can exhibit stronger spontaneous polarization than a compound having a chiral group on only one side.

That is, the compound (A) and the following general formula (F) (wherein,
R7 represents an optically inactive alkyl group, Z'',
, C'', R'' represent the same thing as -Sailor (A), only on one side where it is represented by formula (IV-45).

When a compound having an optically active group represented by formula (IV-46) or formula (IV-47) is added to the SC base liquid crystal respectively, and the spontaneous polarization is calculated using the extrapolated value of -2 and C7, 7 under the same conditions. In this case, the compound represented by -Funenin (A) is considerably larger, and in particular, the optically active group of formula (IV-31
) ~ Formula (IV-33), (IV-43), Formula (I
V-53), formula (IV-74) or 2 (IV-75)
100-200 nC/C1m if selected from
” or even larger values in some cases.

When used as a chiral dopant, the larger the induced spontaneous polarization, the smaller the amount needed, so the proportion of the low-viscosity SC host liquid crystal can be increased, and the viscosity of the SC2 liquid crystal composition can be lowered. This results in improved responsiveness.

(2) It is possible to adjust the helical pitch, such as compounds with very long helical pitches and compounds with very short helical pitches induced in the N'' phase or S02 phase.

As mentioned above, in order to obtain good orientation, it is important that the helical pinch in the N'' phase or SC1 phase is long. It is sufficient that the helical pitch of the chiral dopant is adjusted as a whole. Although this is not necessarily the case for individual compounds, it is easier to adjust the main component of a chiral dopant if the helical pitch is long to some extent.Also, compounds added with the main purpose of adjusting the helical pitch Then, the shorter the spiral pinch, the more advantageous it is because the amount of addition can be suppressed.

The compound of general 2 (A) is preferably used in an amount of 5% by weight or more, preferably 20% by weight or more, as a constituent component of the chiral dopant.
) to the basic skeleton represented by the formula (V = 539), the formula (I
A compound in which any two to J or one (the other is an optically inactive chain group) of the optically active groups represented by formulas V-i) to Hy-91) are bonded as a side chain. Can be used.

The above chiral dopant is present in the SC matrix liquid crystal at 1 to 60%.
It is appropriate to add the chiral dopant in an amount of 60% by weight and use it as an SC" liquid crystal composition, but it is more preferable to add it in an amount of 2 to 50% by weight. If the amount is too large, the spontaneous polarization increases, but since the chiral dopant itself has a much higher viscosity than the base liquid crystal, the viscosity of the S00 liquid crystal composition increases, which tends to adversely affect high-speed response. In addition, increasing the amount of chiral dopant added tends to shorten the helical pitch and adversely affect the orientation, so it is undesirable. If it is less than 1% by weight,
Spontaneous polarization becomes too small and high-speed response cannot be expected.

The spontaneous polarization value of the “sc” liquid crystal composition is 3 to 30 nC/c.
It is preferable to adjust the addition ratio of the chiral dopant so that it is within the range of 100 nC/C1!, and in the case of a chiral dopant exhibiting the S01 phase, it exhibits spontaneous polarization of about 100 nC/C1! , or in the case of a chiral dopant that induces spontaneous polarization with an intensity equivalent to that, the addition ratio of the chiral dopant is preferably in the range of 10 to 40% by weight, and 300% by weight.
In the case of a chiral dopant that exhibits a strong spontaneous polarization of nC/can” or more, the addition ratio of the chiral dopant is 2 to 2.
A range of 25% by weight is preferred. The more the spontaneous polarization induced by the chiral dopant becomes stronger, the more desirable its addition ratio decreases, but in the chiral dopant made of the optically active compound exemplified, the addition ratio never falls below 1% by weight.

When the S00 liquid crystal composition of the present invention is cooled from an isotropic liquid state, it undergoes a phase transition from the N1 phase to the SA phase to the S00 phase. More preferably, the S01 liquid crystal composition has a helical pitch of 3 μm or more that appears in the N'' phase from the N''-3A point ) to the 1 degree higher temperature side of the N''-3A point,
The pitch of the spiral is 10 μm or more, and the pitch of the spiral increases divergently as it approaches the N''-3A point.
C" liquid crystal compositions are particularly preferred.

-Among Funato's (A) optically active compounds, 15 compounds in which the helical directions induced in the N'' phase by the chiral groups on both sides are opposite to each other, the induced helical pitch is quite long. When such a compound is used as the main component of a chiral dopant, adjusting the helical pitch is often unnecessary or easy; however, for boat fishing, the helical pitch can be adjusted to a longer length as follows. I can do it.

The pitch P (μm) of the helix appearing in the N1 phase of the S01 liquid crystal composition containing multiple optically active compounds is determined by Ci representing the concentration of each optically active substance and Pi representing the pitch of the helix per unit concentration of each optically active substance.
(μm) (here, the right-handed spiral pitch is positive and the left-handed spiral pitch is negative), and using this, S00
When pi at point T0 of the liquid crystal composition 5A-N'' is PT'', Ct may be selected such that. Here, Pi can be measured by adding each optically active compound at a unit concentration to the SC liquid crystal having an N phase.

In reality, To varies depending on each (j), but it can often be estimated fairly accurately from the change in the 5A-N'' point when each optically active compound is added to the SC matrix liquid crystal at a concentration ΣCi, etc. If the estimated value T.' differs greatly from To of the composition selected using it, it is sufficient to replace T0' with To and perform the measurement again.

The temperature range showing the N0 phase of the S01 liquid crystal composition of the present invention is:
A range of 3 degrees or more and less than 30 degrees is preferable.

If the temperature range in which the N" phase is exhibited is less than 3, the phase transition to the SA phase occurs immediately upon cooling down, which tends to make it difficult to fully align liquid crystal molecules in the N" phase, which is not preferable. Further, when the temperature range showing the N1 phase is 30 degrees or higher, the clearing point of the S00 liquid crystal composition becomes high temperature, which tends to not adversely affect the workability in the process of filling the cell with the liquid crystal material, etc., which is preferable. do not have.

A chiral dopant is one that, when added to an SC base liquid crystal, regardless of whether the chiral dopant itself has liquid crystallinity, (1) tends to expand the temperature range in which the N'' phase is exhibited, or (2) N ``Each has unique properties, such as those that tend to narrow the temperature range in which they exhibit a phase. S0 of the present invention
1 In order to adjust the temperature range in which the N″ phase of the liquid crystal composition is exhibited to the above-mentioned preferred range, in the case of (1), an SC base liquid crystal having a narrow temperature range in which the N phase is exhibited or an SC which does not exhibit the N phase is used.
In the case of (2), it is sufficient to use an SC matrix liquid crystal that exhibits a wide temperature range in which it exhibits the N phase.This method is applicable not only to the N* phase but also to the SA phase and the SCI phase. For example, if the chiral dopant expands only the SA phase of the SC1 liquid crystal composition and reduces the N'' phase and S01 phase, the upper limit temperature of the SC phase can be applied as the SC base liquid crystal. is high, the N phase temperature range is wide,
In addition, it is sufficient to use one having a phase sequence of SC phase→N phase→I phase, or one having a phase sequence of narrow SA phase temperature range<SC phase→SA phase→N phase→L phase.

Such a tendency of the chiral dopant can be easily determined by measuring the change in phase transition temperature of the S00 liquid crystal composition obtained by adding a certain amount of the chiral dopant to the SC base liquid crystal. From this result, in the S04 liquid crystal composition. The temperature range showing each phase, especially the N1 phase, can be easily adjusted.

The chiral dopant used in the present invention is required to induce a certain level of spontaneous polarization (hereinafter abbreviated as P) by adding it to a certain amount of SA host liquid crystal.

As mentioned above, the amount of the chiral dopant to be added may be adjusted so that the value of P for the SC liquid crystal composition falls within the range of 3 to 300 C/cI112, especially near room temperature. When the value of Pl induced by bunt is small, the amount of Pl added increases relative to the SC base liquid crystal, and accordingly, the viscosity of the S00 liquid crystal composition increases, and as a result, high-speed response cannot be obtained. Therefore, the chiral dopant used in the present invention is preferably one that can induce P of 1.0 nC/cm or more when added to the SC base liquid crystal in an amount of 10% by weight. 0,5 n when added in wt%
Particularly preferred are those capable of inducing P of C/crx" or higher.

〔Example〕

The present invention will be specifically explained below with reference to Examples, but the gist and scope of the present invention are not limited by these Examples. In addition, in the examples, "%" is % by weight.
represents. The phase transition temperature of the composition can also be measured using a polarizing microscope equipped with a temperature control stage and a differential scanning calorimeter (DS).
C) was used in combination.

Example 1 A compound represented by the above-mentioned -Funenin (1-a-1) as a medium-temperature range matrix liquid crystal, and a compound represented by the above-mentioned -Funenin Cm-a- as a high-temperature liquid crystal.
An SC matrix liquid crystal (A) was prepared using the compound represented by 1) in the following proportions.

(1-a-1) (III-a-1) This SC matrix liquid crystal (A) has an SC phase at 68.5°C or lower,
It was a low-viscosity composition exhibiting an SA phase at 73.5°C or lower and an N phase at 83.5°C or lower. Also, its melting point is 1
The temperature was 3.0°C.

Next, when added to the SC base liquid crystal to form an SC0 liquid crystal composition, 55% of the compound of the formula (Vl-13) is added as a compound that causes a right-handed helix to appear in the N0 phase, and a left-handed helix is made to appear in the N0 phase. A chiral dopant whose helical pitch was adjusted to form a compound and appear in the N0 phase was prepared.

10% of this chiral dopant and 90% of the SC matrix liquid crystal
The spontaneous polarization value of the sc" liquid crystal composition at 25° C. was 10 nC/cm".

This SC* liquid crystal composition maintains the SC4 phase up to 69°C, and maintains the SC4 phase up to 73°C.
It showed an SA phase up to 80°C and an N0 phase up to 80°C, and became an isotropic liquid (1) phase at higher temperatures.

Moreover, its melting point was not clear. The helical pitch of the N1 phase at 74.5"C of this SC "liquid crystal composition is 20
μm or more, and when it was filled into an orientation-treated cell and slowly cooled from the I phase, it showed extremely good orientation. When a 501L rectangular wave with an electric field strength of 10VF-P/μm was applied to this cell and the electro-optic response speed was measured, it was found that 25
A high-speed response of 52 μsec at ℃ was confirmed. The tilt angle at this time was 23.5''.

〔Effect of the invention〕

The ferroelectric liquid crystal composition of the present invention is a liquid crystal material that has excellent alignment properties and high-speed response, and can operate in a wide temperature range including room temperature.

Therefore, the ferroelectric liquid crystal composition of the present invention is extremely useful as a material for liquid crystal devices using ferroelectric smectic liquid crystals.

teenager Reason Man

Claims (1)

[Claims] 1. (1) Smectic C having a two-ring structure, which is optically inactive and may be monotropic in any temperature range of 1 degree or more at 10 degrees Celsius or higher. (b) a liquid crystal compound exhibiting a smectic C phase with a three-ring structure having a cyclohexyl ring, or (c) the above (a)
or a homologue of the compound of (b) that differs only in the number of carbon atoms in the alkyl chain or in the structure;
2) Optically inactive, the upper limit temperature of the smectic C phase is 90°C or higher, and may be monotropic at least in a temperature range of 5°C or higher; (a) consisting of a 3-ring or more ring structure; , a liquid crystal compound exhibiting a smectic C phase, or (b) a high-temperature liquid crystal exhibiting a smectic C phase consisting of a homologue of the compound that differs only in the number of carbon atoms or structure of the alkyl chain. A ferroelectric liquid crystal composition made by adding (3) a chiral dopant to a material, where the chiral dopant has the general formula (A) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R^1 is carbon Represents an alkyl group or alkoxy group having 2 to 10 atoms, R^2 represents an alkyl group having 1 to 10 carbon atoms or an optically active alkyl group having 4 to 10 carbon atoms, and l represents an integer of 0 to 10. It represents, Z^a is -
Represents O-, -COO-, -OCO- or a single bond.
C^* and C^*^* are each independently (R) configuration or (
S) represents an asymmetric carbon atom in the configuration. X is a general formula (B) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ General formula (C) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Or general formula (D) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (Formula Medium, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas,
There are chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ are each independently saturated or unsaturated 5-membered or 6-membered ring hydrocarbons Although it represents a ring, any 1 or 2 -CH= in the ring may be substituted with -N= or ▲There are numerical formulas, chemical formulas, tables, etc.▼, and any 1 or 2 -CH= in the ring ~2 -CH_2- are
-O-, -S-, -NH-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ may be substituted, and any one to The two ▲There are mathematical formulas, chemical formulas, tables, etc.▼ may be replaced with ▲There are mathematical formulas, chemical formulas, tables, etc.▼. Y^1 represents a fluorine atom, a chlorine atom, a cyano group, a methyl group, or a methoxy group, and Z^1, Z^2 or Z^3 each independently represent a single bond,
-COO-, -OCO-, -CH_2O-, -OCH_
2-, -CH_2CH_2-, -C≡C-, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas There are tables, etc. ▼ or -CH=CH-
represents, Z^4 is -CH_2-, -CH_2CH_2
-, -CH=CH-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -S-, or -O- Representation,
m and n each independently represent 0 or 1. ) represents the central skeleton (core) part of a liquid crystal molecule. ] A ferroelectric liquid crystal composition exhibiting a chiral smectic C phase in a wide temperature range including room temperature, which is characterized by containing an optically active compound represented by the following. 2.X is a general formula (E) ▲There are mathematical formulas, chemical formulas, tables, etc.▼
There are chemical formulas, tables, etc. ▼ and ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ are each independently ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and Y^
2 and Y^3 each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, or a cyano group, but Y^2 and Y^3 do not represent a hydrogen atom at the same time. Z^1, Z^2 and m
represents the same thing as described in claim 1. 2. The ferroelectric liquid crystal composition according to claim 1, wherein the central skeleton (core) portion is represented by: ). 3. When cooling from an isotropic liquid state, 3 degrees or more 3
In the temperature range from the temperature at which the chiral nematic phase undergoes a phase transition from the chiral nematic phase to a phase on the lower temperature side through a chiral nematic phase having a temperature range of less than 0 degrees to the temperature 1 degree higher than the phase transition temperature, the chiral nematic 3. The ferroelectric liquid crystal composition according to claim 1, wherein the phase has a helical pitch of 3 μm or more. 4. The ferroelectric liquid crystal composition according to claim 3, which undergoes a phase transition to a chiral smectic C phase via a smectic A phase having a temperature range of 1 degree or more and less than 30 degrees upon cooling from a chiral nematic phase.