JPH03207790A - Ferromagnetic liquid crystal composition - Google Patents

Abstract

PURPOSE:To provide the subject composition useful as a material for liquid crystal devices and having excellent orientation ability and high speed responsibility by adding a chiral dopant to a matrix liquid crystal containing specific two components and exhibiting an optically inactive smectic C phase. CONSTITUTION:(B) A chiral dopant consisting of an optically active compound to (A) a matrix liquid crystal exhibiting an optically inactive smectic C phase and containing (i) a compound selected from compounds of formula I-III (R<a>, R<b> are 1-20C chained alkyl, alkoxy, but at least one of the R<a>, R<b> is alkoxy), etc., and (ii) a compound of formula IV (R<e>, R<f> are 1-18C chained alkyl or alkoxy; V is COO or OCO; ring A is group of formula V or VI, etc.; ring B is group of formula V or VII, etc.; ring C is group of formula VI, VII, etc.; but at least one of the rings A-C is group of formula V or VI, etc.) to provide the objective composition exhibiting a chiral smectic C phase in a wide temperature range including room temperature.

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 present invention provides a liquid crystal material that has particularly excellent responsiveness and memory performance compared to other liquid crystal materials, and can be used in liquid crystal display devices. [Prior Art] The currently widely used liquid crystal display elements are mainly TN-type devices that use nematic liquid crystals. Although they have many advantages, their responsiveness is inferior to that of CRTs, etc. Many liquid crystal display systems other than the TN type, which had the major drawback of being much slower than the light-emitting type display systems used in 2015, 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 00 times faster response and has bistability, 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 ferroelectric liquid crystals belongs to the tilted chiral smectic phase, and among these, the one that is practically desirable is the chiral smectic C (hereinafter abbreviated as sc0) phase, which has the lowest viscosity. It is called. [Invention tries to solve it! *a) Liquid crystal compounds exhibiting the SC11 phase (hereinafter referred to as SC''' compounds) have been studied, and many compounds have already been synthesized. The following conditions must be met for use as an optical switching element for ferroelectric liquid crystal displays: (a) It must exhibit ferroelectricity in a wide temperature range including room temperature (b) It must have an appropriate phase series in a high temperature range ( c) Particularly chiral nematic (hereinafter abbreviated as N0).
) exhibiting a long helical pitch in the phase; (2) having an appropriate tilt angle; (e) having low viscosity; (f) having a large value of spontaneous polarization above a certain level. There is no known material that satisfies all of the following: exhibiting good orientation as a result of (i), (e) and (e), and exhibiting high-speed response as a result of (e). Therefore, at present, liquid crystal compositions exhibiting the S00 phase (hereinafter referred to as SC1 liquid crystal compositions) are currently being used for research purposes. In order to obtain good distribution,
For example, as shown in Japanese Unexamined Patent Application Publication No. 61-153623, it is common to increase the length of the helical pitch of the N''1 phase in liquid crystals that have an N'' phase in the high temperature range of the sc'' phase. In this case, if the smectic A (hereinafter abbreviated as SA) phase is present in the temperature range between the SC0 phase and the N8 phase, the orientation will be better, and in order to increase the helical pitch, It is also known that an optically active substance that produces a left-handed helix and an optically active compound that produces a right-handed helix can be used in combination.
Abbreviated as N. ) It is already a known technique to adjust the helical pitch to an arbitrary length by adding an optically active substance to liquid crystal. ) However, although these techniques can provide good orientation, they do not necessarily provide high-speed response. In order to exhibit high-speed response, for example, as shown in the special lecture at the 12th Liquid Crystal Conference (Proceedings of the same conference, p. 98), low-viscosity smectic C (hereinafter abbreviated as SC) is required. ) phase (hereinafter referred to as SC matrix liquid crystal) has a spontaneous polarization (hereinafter abbreviated as P3).
) is superior.
According to this method, the proportion of the optically active compound that produces the helix is small, so the helical pitch is relatively long. need to be,
As a result, there was a problem in that the spontaneous polarization became too small, making it impossible to obtain high-speed response. Further, those that have been used so far 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. [10 1TOCOO}) or (R, R' represents an achiral alkyl group.) (R,
R' is the same as above. ), the compounds themselves or their homologs are limited to those exhibiting the SC phase, or in addition, compounds containing liquid crystal compounds that exhibit strong dipole (polarization) in the direction perpendicular to the molecular long rings are added. The problem was that if the temperature range of the SC phase was kept wide, the viscosity would increase, and if the viscosity was decreased, the temperature range of the SC phase would become narrow. Therefore, with conventional technology, it is 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 for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a matrix liquid crystal that is optically inactive and exhibits a smectic C phase (hereinafter referred to as an SC matrix liquid crystal) from an optically active compound. A liquid crystal composition exhibiting a chiral smectic C phase in which a chiral dopant is added, wherein the parent liquid crystal is (1) represented by the following general formula (A-1), (A-2), or (A-3).
, (A-4) and (A-5), and (2) the following general formula (B
) A ferroelectric liquid crystal structure exhibiting a chiral smectic C phase in a wide temperature range including room temperature is provided. General formula (A-1) General formula (A-2) General formula (A-3) R”-4 or Edo general formula (A-4) General formula (A-5) Ra4coo (A-1) to (A-5), R1 and Rh
each independently represents a linear or branched alkyl group or alkoxyl group having 1 to 20 carbon atoms, and at least one group among R1 and Rb represents an alkoxyl group, but preferably RI1 and One group of Rh represents a linear alkyl group having 4 to 12 carbon atoms, and the other group represents a linear or branched alkoxyl group having 4 to 12 carbon atoms. ) General formula (B) (In the formula, R● and Rt each independently have a carbon atom number of 1 to 1
Represents a straight-chain or branched alkyl group or alkoxyl group, and ■ represents at least one of -COo or -OCO -F ■ and ←6←. ) Compounds belonging to Group A are compounds that exhibit an SC phase at or near room temperature, or their homologs (compounds that differ only in the number of carbon atoms in the alkyl chain and/or the shape thereof), and have a high viscosity. Although it has a moderate value, it is a compound that greatly contributes to expanding the temperature range of the SC phase to low temperatures. The present invention particularly provides the general formula (A-1),
(A, 2), (A-3), (A-4) or (A-5
) is characterized in that it contains at least l types of compounds represented by: General formulas (A-1), (A, 2), (A-3), (A-
More specifically, the compounds represented by (4) and (A-5) include the following compounds. R"0 I crawl coo it ORゝ...(A-53)-a
Among the compounds represented by formulas (A-11) to (A-53), general formulas (A-11), (A-12), (A-21)
, (A-22), (^-31), (A-32), (A-
41), (A-42), (A-52) and (A-53)
Preferably, the compound represented by the general formula (A-11),
(A-12), (A-22>, (A-31) and (A-
Particularly preferred are compounds represented by 53). If necessary, the following compounds (1) to (3) may be included as compounds in the liquid crystal composition as compounds having properties similar to the compounds belonging to Group A. (1) In general formulas (A-1) to (A-3), at least one of R' and R' is an alkoxycarbonyl, alkanoyloxy, or alkoxycarbonyloxy group, and the other group is Alkyl, alkoxy, alkoxycarbonyl, alkanoyloxy or Al J-j
Compounds that are p-cyclocarbonyl groups. (2) A compound represented by the general formulas (A-1) to (A-3) or the above (1), and any one C←(3) A compound represented by the following general formula (A-4) ．． (A-7) Represented by the general formula (A-4)
Ri and R' each independently represent an alkyl, alkoxyl, alkylthio, alkoxycarbonyl, alkylthiocarbonyl, alkanoyloxy, or alkoxycarbonyloxy group, but at least one of the groups is not an alkyl group, and is at the 2- or 3-position. F may be substituted for . ) General formula (A-5) R5OCOOGR' ... (A-5) (in the formula, R.
and Rj have the same meaning as in general formula (A-4) and represent. ) General formula (A-6) (In the formula, Ri and Rj represent the general formula (A-4).) General formula (A-7) The same meaning as in the general formula (A-6) have. ) The compound represented by the general formula (B) can be SC
Tc exhibits a phase or even if it does not exhibit a sc phase.
By adding it to a liquid crystal composition with a low upper limit temperature (SC phase), it has the effect of increasing its Tc, and contributes to expanding the temperature range of the SC phase, especially in the high temperature range. Specifically, the following compounds can be mentioned. / ・F/ In the above, SB is smectic B phase, SF is smectic F phase, SG is smectic G phase, and SH is smectic H phase.
The phases S and S' each represent a separate, unidentified smectic phase. Among the above compounds, general formulas (C-6), (C-13)
Particularly preferred are compounds represented by and (C-20),
Compounds in which at least one of R1 and R' is an alkyl group are particularly preferred because they have low viscosity. Examples of compounds having effects similar to those of the compound represented by general formula (B) include compounds represented by the following general formula (G). These can be used in combination with the compound represented by general formula (G). General formula (G) In the formula, R''' and R'' each independently have 1 to 1 carbon atoms.
8, preferably 3 to 12 linear or branched alkyl groups, and Z1 and Z each independently represent -coo-
, -oco-, -o-, -s represents one or a single bond, preferably at least one represents a single bond. Z, and Zs are each independently -coo-, -oco
-CH*0 0CHg, COS,
-SCO, CBz-Cllz-, CmiC- or a single bond, but at least one is preferably a single bond. IΣ, ×=〉 and {En each independently represent a ring structure in which any one or two hydrogens in the ring of are substituted with fluorine, preferably ×Σ, a fluorine substituted product), Further, in at least one of the SC parent liquid crystals used in the present invention, the proportion of Group A compounds is preferably in the range of 10 to 98% by weight, particularly preferably in the range of 50 to 95% by weight. The proportion of the compound represented by the general formula (B) is preferably in the range of 1 to 90% by weight, particularly in the range of 5 to 50% by weight, because if it is too small, the Tc will be low, and if it is too large, the responsiveness will be reduced. The SC base liquid crystal used in the present invention has a phase sequence of (a) I (isotropic liquid) phase → N phase → SA phase → SC phase on the high temperature side of its SC phase when the temperature is lowered (b) (iii) Those with a phase sequence of phase → SA phase → SC phase (c) Those with a phase sequence of I phase → N phase → SC phase, or (2) Those with a phase sequence of I phase → SC phase. However, the selection of (a) to (ii) is based on the chiral dopant used simultaneously and the SC′″
It differs depending on the preferred phase series when used as a liquid crystal composition. The most commonly used method is (a), in which there is a strong tendency to widen the temperature range of the N1 phase and narrow the temperature range of the SA phase etc. when a chiral dopant is added to the SC base liquid crystal. (r2) expands the temperature range of the SA phase when a chiral dopant is added to the SC matrix liquid crystal, and N
(c) is used when there is a strong tendency to narrow the temperature range of the 0 phase, and (2) is used when the SC property is weak and the temperature range of the N1 phase and SA phase is likely to be widened. Most suitable. What is important is the phase series when using an SC0 liquid crystal composition, and generally, ■→N1→SA→SC
0 phase series is advantageous in terms of orientation. On the other hand, 1→N9→
The SC0 phase series may also exhibit better orientation depending on the orientation control method, and a large tilt angle can be easily obtained, so it is suitable for the guest-host system.

In addition, the phase series of ``I-43A-4SC'' is similar to that of the early ferroelectric liquid crystals (p-decyloxybenzylideneanocinnamic acid (S)-2-methylbutyl, etc.), so the orientation method The chiral dopants used in the present invention include (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, but in the case of (3),
In order to prevent the tendency for the liquid crystallinity of the SC1 liquid crystal composition obtained by adding it to the base liquid crystal to decrease, it is preferable to use a compound having a skeleton similar to that of a liquid crystal. Among the various physical properties that a chiral dopant brings to an SC0 liquid crystal composition, important ones are the helical pinch it induces, the direction and magnitude of spontaneous polarization; It is most affected by the optically active site. Until now, chiral dopants, sc”
Typical optically active groups in optically active compounds that have been used as compounds or additives to nematic liquid crystals are listed below. (IV-1) CI. + CHz+TCH CtHs (IV-2) CH. -0 +CH, CHi-CH-C. lI5(IV-
3) CL +CHzh-0 + CHz-÷yCH CJs(I
V-4) CH, 1 -O{- CHz}=-0 -{- CHg-NyCH
CzHs (IV-7) CH3 +CH1÷7CB Rs (■ 8) CH. -0 + CHz-}-CH Rs (IV-12) CIi3 -CH R4 (IV-13) CB, -CHz-CI Cut ORs (IV-14) CHI - CH - CHt - ORS (IV-21) CHs - S + CHz 'na, Cll(CHz}r- C
Hs(IV-32) CH3-O-CB-R. (■ 35) 10-ji H-L; I'I. -L;tl-ut<s(IV
-4zノ1016-jikl L;)lx Ltl
L, zlls (IV-48) -(;li-L;1υ-H5 (IV-53) CH, CH 0-R, (IV-55) -O-CB.-Cll FIS (IV-57) Cl -O CHx CH Rs (IV-62) CF3 -0-CH-RS (IV-64) 10 CI. CH! CI CB! ORs (IV-65) Cfl3 -0-CB-CH. ORs (IV-66 ) CHs −0 + GHz−+−rCl{CHt}ii− OR
s(IV-67) -COOCHz Cl (;tl L;z
tls (IV-69) Cl -COOCB* CO Rs (IV-70) Cll, -O Cut CH CHz OCORs (I
V-71) CH. O CH CB* O CORs (■ 72) CH3 0 CH GHz{CHt}i-OCORs (IV
-73) -O-CHI CH3 CB-{CHt)-i-OCORs (IV-75) CHs 1 O CL CI ORs (!V-76) CH3 -S-CHRs (IV-78) CtHs O-CB, -CI-0 (■ 79) -O-C-O-jikl K4 (IV-80) COOCIIg CI Rs (IV-81) CN -O CHg CB Rs (IV-82) CN CO Rs (IV-83 ) cnzcN COO CH* Cll Rs (IV-84) CH. CN O CHZ CH Rs 0 In each of the above general formulas, m represents an integer of 1 to 4, and n
represents an integer of 1 to 10, R represents an alkyl group having 3 to 8 carbon atoms, R4 represents an alkyl group having 2 to 10 carbon atoms, and RS represents an alkyl group having 1 to 10 carbon atoms. where R6 represents an alkyl group having 1 to 4 carbon atoms. As optically active groups, formulas (IV-1) to (IV-22
) In optically active compounds containing only the optically active group represented by
Even if it shows the c” phase, most of it is 10nC/cm”
No more than the following.

On the other hand, as optically active groups, formulas (IV-31) to (■-9
Many of the optically active compounds containing the optically active group represented by 1) induce a large spontaneous polarization when added to the SC base liquid crystal to form an SC9 liquid crystal composite, and when used alone, they induce a large amount of spontaneous polarization.
In some cases, such as when exhibiting a phase, there are compounds that exhibit large values of 300 nC/cm" or more. Typical basic skeletons of optically active compounds that have such optically active groups at their ends are listed below. ( V-12) ? OCR! O Be C00〈舅(V 228) G bar + oco term} (V-247) G 汽嵜coo freeze} (V-25i) O bar and coo term} (V-252) 0 bar oco -@ (V-253) Obaryo co..o{} (V-500) {*ki coo mulberry λ Fluorine atom, chlorine atom, bromine atom, methyl group, methoxy group, cyano group or Various basic skeletons substituted with nitro groups can also be used. Optically active compounds in which the above chiral groups are bonded to one or both sides of the Go main skeleton as described above can be effectively used as a component of a chiral dopant. In particular, the general formula (D) in which the chiral groups are bonded to both sides, Q-Z Qi- [wherein Q" and Q gN" are mutually different optically active groups, and each optically active group has at least one and at least one of Q'' and Qlm has an asymmetric carbon atom of oxygen, ioOI1, nitrogen, fluorine, chlorine, or 1C1 or 1C3. It has a structure directly connected to N. Z represents a structure of the general formula (E) in which any one or two hydrogen atoms on these rings are replaced with a fluorine atom or a cyano group, and YI and Y2 are each independently a single bond, -COO-- OCO--
cogo-, OCIIg CHtCHg-102C-, -COS- or -SCO-, S is 0
Or represents 1. ) represents the central skeleton (core) of a liquid crystal molecule. ] Optically active compounds represented by the following are preferred. Furthermore, preferably, the optically active groups Q1 and Q1 each have the following general formula (F-1
) and (F-2). General formula (F-1) XI Rl -CH-Y" - General formula (F-2)
0 alkyl group, or an alkoxyl group, alkoxycarbonyl group, or alkanoyloxy group having 1 to 10 carbon atoms, C8 represents an asymmetric carbon atom, and X+ and X8
each independently represents cttx-F1, Cf1 or -CN, and yz and ys each independently represent a single bond, -o-
-coo- -oco-+ CHz}17 0 +
Cllt■, +Cut}rr OCO child CL stone or +
C.B. Represents C00+CHm stone under h, i1, i! ．． 2
, m1, m2, n1 and n2 each independently represent an integer from 0 to 5. ) More preferably, the chiral groups are not the same, and at least one of them has an asymmetric carbon atom of oxygen (O),
Sulfur (S), nitrogen (N), fluorine (F), chlorine (C
j! ) etc. or 0 11 has a structure directly connected to C, CN, especially in the above (I
V-31) to (IV-101) are preferable. As described above, the advantages of using an optically active compound in which different chiral groups are bonded to both sides of the basic skeleton are as follows. (1) It can exhibit stronger spontaneous polarization than compounds with chiral groups on only one side. That is, a chiral group selected from the groups represented by (IV-31) to (IV-91) above and (IV-1) to (IV
-22) A compound having a chiral group selected from groups represented by (IV-31) to (■-91) on both sides of the basic skeleton, and a compound having the same basic skeleton with chiral groups selected from groups represented by (IV-31) to (■-91). Compounds that have only the same group and an achiral group on the other side are added to the SC matrix liquid crystal, and when the spontaneous polarization is determined as an extrapolated value, it is found that the compound that has chiral groups on both sides is 10 to 30 nC/cm" or larger, the spontaneous polarization derived from the groups represented by (IV-1) to (IV-22) is at most 10 nC/cv"
It can be seen that this is larger than the simple sum of the spontaneous polarizations due to the chiral groups on both sides. Furthermore (IV
-31) to (rV-91), and which have different chiral groups on both sides of the basic skeleton, the polarity of spontaneous polarization due to both chiral groups (often (S)- is a known ferroelectric liquid crystal.
Determine the polarity of 2-methynolebutyl b-decyloxybenzylidene aminophenyl cinnamate (IlOBAMBC) as e. ), a very large spontaneous polarization can be obtained. In this case, it is possible to obtain a spontaneous polarization that is 1001 IC/Cll or even larger than the simple sum of the spontaneous polarization caused by the chiral groups on both sides.As a chiral dopant, the spontaneous polarization that it can induce is large. Since the amount used can be reduced, the proportion of low-viscosity SC liquid crystal can be increased, and as a result, it is possible to reduce the viscosity of the SC゜ liquid crystal composition.As a result, the responsiveness (2) It is possible to adjust the helical pitch in compounds where the helical pinch induced in the N'' or SC0 phase is very long or very short. As mentioned above, in order to obtain good orientation, the N1 phase or S08
It is important that the helical pitch in the phase is long. It is sufficient that the helical pitch of the chiral dopant is adjusted as a whole, and it is not necessary for individual compounds to do so. Easy to adjust.
Furthermore, in the case of a compound added primarily for the purpose of adjusting the helical pinch, the shorter the helical pitch is, the more convenient the amount added can be suppressed.

In order to lengthen the helical pitch, the directions of the helical pitch due to the chiral groups of both Confucian groups should be opposite to each other, but (IV-31
) to (IV-91), it is preferable that the polarities of their spontaneous polarizations be the same. (3) A chiral group particularly selected from the groups represented by (IV-31) to (rV-91) that exhibits large spontaneous polarization, and which is obtained by chemical methods such as asymmetric aggregation and optical resolution. Although many of these substances do not necessarily have 100% optical purity, it is quite difficult to purify them to 100%. However, when combined with chiral groups derived from naturally occurring (S)-2-methylbutanol or chiral groups with extremely high optical purity, such as those obtained by microbial engineering techniques, these become diastereomers. Therefore, separation by chromatography and recrystallization becomes easy, and optical purity can approach 100%. It is effective to use the compound of general formula (B) in an amount of 10% or more, preferably 30% or more, particularly preferably 50% or more as a constituent component of the chiral dopant. Among the compounds of general formula (B), compounds having particularly preferable combinations of basic skeleton and chiral group are shown below. In the above general formula, R4 and R4' each independently represent an alkyl group having 2 to 10 carbon atoms, and Rs and R, /
each independently represents an alkyl group having 1 to 1 carbon atoms, and R9 is a linear alkyl group having 2 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms, or represents an optically active alkyl group containing at least one asymmetric carbon of 4 to 10, i represents an integer of O to 5, Y is a single bond, -o-, -oco-, -coo-
, or -ocoo-, W represents chlorine fluorine or -0-CH3, and Z' is -COO- -OCO- -CB. 0- -OCR Hoichi. Or simply. XI and X4 each independently represent a hydrogen atom, a fluorine atom or a cyano atom, X 4 represents a hydrogen atom or XI,
X3 represents a hydrogen atom or X4, and at least one of X4 represents a hydrogen atom.
It is appropriate to add it in a proportion of 2% by weight and use it as an SC1 liquid crystal composition, but it is more preferable to add it in a proportion of 2 to 50% by weight. When the addition ratio of the chiral dopant is more than 60% by weight, the spontaneous polarization increases, but since the chiral dopant itself has a much higher viscosity than the base liquid crystal, the viscosity of the SC0 liquid crystal composition increases, resulting in This is not desirable because it tends to have a negative effect on high-speed response. Further, an increase in the amount of chiral dopant added tends to shorten the helical pitch, which tends to adversely affect the orientation, which is not preferable. On the other hand, if the proportion of the chiral dopant added is less than 1% by weight, the 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/
It is preferable to adjust the addition ratio of the chiral dopant so that it is in the range of cm', and in the case of a chiral dopant that exhibits the SC1 phase, it alone exhibits a spontaneous polarization of about 100 nC/11 "m" or equivalent thereto. In the case of a chiral dopant that induces strong spontaneous polarization, the addition ratio of the chiral dopant is preferably in the range of 10 to 40% by weight, and 30% by weight.
In the case of a chiral dopant that exhibits strong spontaneous polarization of 0 nc/cm" or more, the addition ratio of the chiral dopant is 2 to 2.
A range of 25% by weight is preferred. The stronger the spontaneous polarization induced by the chiral dopant, the lower its most desirable addition ratio. However, the chiral dopant-induced P
If the value of 1 is small, the amount added will be large relative to the SC base liquid crystal, and the viscosity of the S01 liquid crystal composite will increase accordingly, and as a result, high-speed response will tend not to be obtained. I don't like it because it is. Therefore, when the chiral dopant used in the present invention is added to the Sc host liquid crystal in an amount of 10% by weight, 1. Those capable of inducing P of 0 nC/cya'' or more are preferable, and those capable of inducing P of 0.5 nCΔ1 or more when added in an amount of 5% by weight are particularly preferable. During cooling from the isotropic liquid state, the N1' phase, SA phase, or N
There is a phase transition to the sco phase through the 0 phase and the SA phase, but the I
The pitch of the helix that appears in the N11 phase from the phase transition temperature from the IN'' phase to the SA phase (hereinafter referred to as the N''-SA point) to one degree higher than the N''''-SA point is 3 μm or more. An sc8 liquid crystal composition is more preferred, and an sc1 liquid crystal composition in which the helical pitch is 10 am or more, and in which the helical pitch increases divergently as it approaches the N''-SA point, is particularly preferred. The temperature range in which the SC'' liquid crystal composition of the present invention exhibits the N0 phase is preferably 3 degrees or more and less than 30 degrees.

If the temperature range in which the N1 phase is exhibited is less than 3 degrees Celsius, it is not preferable because the phase transition to the SA phase occurs immediately when the temperature rises, making it difficult to fully align liquid crystal molecules in the N1 phase. Furthermore, if the temperature range showing the N0 phase is 30 degrees Celsius or higher, the clearing point of the sc0 liquid crystal composition becomes high, which is likely to adversely affect workability in the process of filling the cell with liquid crystal material. A chiranoredobant is one that, when added to an SC matrix liquid crystal, regardless of whether or not the chiral redobant itself has liquid crystallinity, (1) tends to expand the temperature range in which it exhibits the N'' phase, or (2) Each of the SCs of the present invention has unique properties, such as those that tend to reduce the temperature range in which the N0 phase is exhibited.
In order to adjust the temperature range in which the N1 phase of the 0 liquid crystal composition exhibits the N1 phase to the above-mentioned preferred range, in the case of (1), the SC base liquid crystal which exhibits the N phase is narrow in the temperature range, or the SC which does not exhibit the N phase.
It is sufficient to use a matrix liquid crystal, and in the case of (2), it is sufficient to use an SC matrix liquid crystal that exhibits N phase over a wide temperature range. This method can be applied not only to the N8 phase but also to the SA phase and SC0 phase. For example, the chiral dopant expands only the SA phase of the SC1 liquid crystal composition, and the N1 phase and S
In the case of reducing the C0 phase, the SC host liquid crystal should have a high upper limit temperature for the SC phase, a wide temperature range for the N phase, and a phase sequence of SC phase → N phase → I phase, or S
It is sufficient to use a material with a narrow temperature range of A phase and a phase sequence of SC phase → SA phase → N phase → ■ phase. Such a tendency of the chiral dopant can be easily determined by measuring the change in the phase transition temperature of the SC1 liquid crystal composition obtained by adding a certain amount of the chiral dopant to the SC base liquid crystal. From this result, it is possible to easily adjust the temperature range in which each phase in the SC1 liquid crystal composite exhibits the N''' phase. Among the optically active compounds of general formula (D), the diagonal chiral group Rl'' In compounds where the helical directions induced in the N8 phase by +Rl are opposite to each other, the induced helical pitch is quite long, so when such a compound is used as the main component of a chiral dopant, Pitch adjustment is often unnecessary or easy, but generally the helical pitch can be adjusted to a longer length as follows. N''' of SC"liquid crystal composition containing multiple optically active compounds
The pitch of the spiral appearing in the phase P (μm) is determined by the concentration of each optically active substance as Ci, and the pitch of the spiral per unit concentration as Pi.
(μm), then P Pi (Here, the right-handed pitch is positive and the left-handed pitch is negative.) Using this, SA- of an SC0 liquid crystal structure is calculated.
When pi at N''' point T0 is p, i, Ci can be selected so that In reality, T0 changes depending on each Ci, but it can be determined quite accurately from the change in the SA-N'' point when each optically active compound is added to the SC matrix liquid crystal at a concentration of ΣCi. There are many things that can be inferred, and estimation [
T. If there is a large difference between ' and T0 of the composite material selected using it, it is sufficient to replace T0' with T0 and perform the measurement again.

〔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, "%" represents weight %. In addition, the phase transition temperature of composite materials can be measured using temperature!
The experiments were carried out using a polarizing microscope equipped with a stage and a differential scanning calorimeter (DSC). Example I A liquid crystal composition exhibiting an SC phase consisting of 35% 35% 30% (hereinafter referred to as base liquid crystal
). ) was prepared.

This assembled paraboloid exhibits an SC phase below 57°C, an SA phase below 64.5°C, and an N phase below 69°C, and its melting point is 1.
The temperature was 4°C.

Next, when added to the SC base liquid crystal to form an SC0 liquid crystal composition, as a compound that causes a right-handed helix to appear in the N'' phase,
Formula (pitch of helix that appears in the N'' phase when 10% of this compound is added to the SC matrix liquid crystal (A) (extrapolation +11)
is 4. at 60°C. It's 7pm. ), and as a compound that makes a left-handed helix appear, the helical pitch (extrapolated value) that appears in the N0 phase when 10% of this compound is added to the SC matrix liquid crystal (A) is 60
It is 11.9 μm at °C. ) to prepare a chiral dopant in which the pitch of the helix appearing in the N1 phase was adjusted.

This chiral dopant is added to the SC base liquid crystal (A) at 1
The spontaneous polarization value of the SC" liquid crystal composition obtained with 0% addition at 25° C. was about 6 nC/cm".

Next, the mother liquid crystal (A) 75.6%B
Compound of formula (B-.6-1) 4.2%
4.2% of the compound of formula (B-6-2) and the above chiral dopant 16. 0%? SC9 liquid crystal g
A relative was prepared. This SC0 liquid crystal 1N compound showed an SC1 phase at 57℃ or lower, an SA phase at 59℃ or lower, and an N'' phase at 64℃ or lower. treatment) 2
When a cell with a thickness of approximately 2 μm consisting of a sheet of glass transparent electrodes was filled and slowly cooled from an isotropic liquid phase to room temperature,
A uniform SC1 phase monodomain with good orientation was obtained. When a rectangular wave of 50 Hz and an electric field strength of 10 V/μm was applied to this cell and its electro-optical response speed was measured, a high-speed response of 49 μsec at 25° C. was confirmed. The spontaneous polarization at this time is approximately 114nC/c1, and the tilt angle is 29.2
°, and the contrast was very good.

Example 2 In Example 1, formulas (B-64) and (B-6-2)
Instead of the compound of formula (B-13-1) and (B-13
SC" liquid crystal set paraboloids were prepared in the same manner as in the example construction except that 4.2% of each of the compounds of -2) was used.
The 1L c" liquid crystal exhibits the sc" phase at temperatures below 56.5℃, 64
It exhibited an SA phase at temperatures below 68.5 °C and an N''' phase at temperatures below 68.5 °C.A display cell was prepared in the same manner as in Example 1, and its electro-optical response speed was measured. It showed a high-speed response of 56 μsec at
C11", the tilt angle was 27.6°, and the contrast was also good. Example 3 In Example 1, formulas (B-6-1) and (B-6-2
) Formula (B-20-1), (B-2
An SC" liquid crystal composition was prepared in the same manner as in Example 1, except that 2.8% each of the compounds B20-2) and (B20-3) were used. SC
1 phase and N1 phase at temperatures below 65°C. A display cell was prepared in the same manner as in Example 1, and its electro-optical response speed was measured, and it showed a high-speed response of 55 μsec at 25°C. At this time, the spontaneous polarization was 14.5 nC/cm'', the tilt angle was large, 30.4'', and the contrast was good. [Effects of the Invention] The ferroelectric liquid crystal composition of the present invention is a liquid crystal material that has excellent coordination properties and high-speed response, and can operate in a wide temperature range including room temperature. Therefore, the ferroelectric liquid crystal &III's of the present invention. The material is extremely useful as a material for liquid crystal devices using ferroelectric smectic liquid crystals. agent

Claims (1)

[Scope of Claims] 1. A liquid crystal composition exhibiting a chiral smectic C phase obtained by adding a chiral dopant consisting of an optically active compound to a matrix liquid crystal that is optically inactive and exhibiting a smectic C phase, wherein the matrix liquid crystal is , (1) The following general formulas (A-1), (A-2), (A-3)
, a compound selected from Group A consisting of compounds represented by (A-4) and (A-5), and (2) a compound represented by the following general formula (C), including room temperature. A ferroelectric liquid crystal composition that exhibits a chiral smectic C phase over a wide temperature range. General formula (A-1) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ General formula (A-2) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ General formula (A-3) ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ General formula (A-4) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ General formula (A-5) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (General formulas (A-1) to (A-5) above) Medium, R^a and R
Each ^b independently represents a linear or branched alkyl group or alkoxyl group having 1 to 20 carbon atoms, but R^
At least one of a and R^b represents an alkoxyl group. ) General formula (B) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R^e and R^f each independently represent the number of carbon atoms, 1
~18 represents a linear or branched alkyl group or alkoxyl group, V represents -COO- or -OCO-, ▲ has a mathematical formula, chemical formula, table, etc. ▼ has a ▲ mathematical formula, chemical formula, table, 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. ▼
Or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ means ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, There are 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. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ Represents ▲ There are mathematical formulas, chemical formulas, tables, etc. There are 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.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, but ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas , there are chemical formulas, tables, etc. ▼ and ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼, at least one of them is ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ mathematical formulas, There are chemical formulas, tables, etc. Represents ▼. 2. The ferroelectric liquid crystal composition according to claim 1, wherein group A comprises a compound represented by general formula (A-1). 3. ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ , ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ is ▲ Mathematical formulas,
3. The ferroelectric liquid crystal composition according to claim 1 or 2, which has chemical formulas, tables, etc. ▼ or ▲ has numerical formulas, chemical formulas, tables, etc. ▼. 4. The ferroelectric liquid crystal composition according to claim 1 or 2, wherein ▲There are mathematical formulas, chemical formulas, tables, etc.▼ is ▲There are mathematical formulas, chemical formulas, tables, etc.▼. 5. The chiral dopant has the general formula (D) Q^1^*-Z-Q^2^* [In the formula, Q^1^* and Q^2^* are different optically active groups, and each The optically active group has at least one asymmetric carbon atom, and in at least one of Q^1^* and Q^2^*, the asymmetric carbon atom is oxygen, sulfur, nitrogen, or fluorine. , chlorine or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or Z, which has a structure directly connected to -C≡N
is a general formula (E) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas,
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. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
or represents a structure in which any one or two hydrogen atoms on these rings are substituted with a fluorine atom or a cyano group, and Y^1 and Y^2 each independently represent a single bond, -COO-, -OCO-
, -CH_2O-, -OCH_2-, -CH_2CH_
2-, -C≡C-, -COS- or -SCO-, and s represents 0 or 1. ) represents the central skeleton (core) part of a liquid crystal molecule. ] Claims 1, 2, containing an optically active compound represented by
5. The ferroelectric liquid crystal composition according to 3 or 4. 6.Q^1^* is an optically active group represented by the following general formula (F-1), and Q^2^* is an optically active group represented by the following general formula (F-2).Claim 5 The ferroelectric liquid crystal composition described above. General formula (F-1) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ General formula (F-2) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R^1 and R^2 each independently Number of carbon atoms: 2
~10 alkyl group, or an alkoxyl group, alkoxycarbonyl group, or alkanoyloxy group having 1 to 10 carbon atoms, C^* represents an asymmetric carbon atom, and X^1
and X^2 each independently represent CH_3-, F-, Cl- or -CN, and Y^2 and Y^3 each independently represent a single bond, -O-, -COO-, -OCO-, Represents ▲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 l1
, l2, m1, m2, n1 and n2 are each independently 0 to 5.
represents an integer. )