JPH0426679A - Liquid crystalline compound, liquid crystal composition containing the same and liquid crystal element using the same - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I [R1 is 1-18C (substituted) alkyl; X1 is single bond or -O-; X2 is F or H; n is 0-8; m is 118]. EXAMPLE:5-n-Decyl-2-[4-(1,1-dihydroperfluorobutyloxy)phenyl]pyrimidine. USE:A liquid crystal composition, improved in response characteristics to electrical fields and utilized for liquid crystal display elements, liquid crystal-optical shutters, etc. PREPARATION:A compound expressed by formula II is reacted with a compound expressed by formula III (Y is Br, I or formula IV) in the presence of a base to afford the objective compound expressed by formula I (group X1 is -O-).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a novel liquid crystal compound, a liquid crystal composition containing the same, and a liquid crystal element using the same, and more specifically relates to a novel liquid crystal compound that has improved response characteristics to an electric field. The present invention relates to a novel liquid crystal composition, and a liquid crystal element using the same for use in liquid crystal display elements, liquid crystal light shutters, and the like.

[Prior Art] Liquid crystals have conventionally been applied as electro-optical elements in various fields. Most of the liquid crystal elements currently in practical use are, for example, M-Shut (M.

5chadt) and W Helfrich (W, He
1frich) “Applied Physics Letters”
rs”) Vo, 1g, No, 4 (1971, 2
, 15) P, 127~128 °'Voltage
Dependent Optical Activity
of a Twisted Nematic 1iq
TN (Twist) indicated in uidCrystal°°
This uses an ed Nematic) type liquid crystal.

These are based on the dielectric alignment effect of liquid crystals, and utilize the effect that the average molecular axis direction is oriented in a specific direction due to the dielectric anisotropy of liquid crystal molecules due to an applied electric field. The optical response speed limit of these devices is said to be milliseconds, which is too slow for many applications. On the other hand, for application to large flat displays, driving by a simple matrix method is the most promising in terms of cost, productivity, etc. In the simple matrix method, an electrode configuration in which a scanning electrode group and a signal electrode group are arranged in a matrix is adopted, and in order to drive the electrode group, an address signal is selectively and periodically applied to the scanning electrode group, and the signal electrode group is A time division driving method is adopted in which a predetermined information signal is selectively applied in parallel in synchronization with an address signal.

However, if the above-mentioned TN type liquid crystal is adopted as an element of such a driving method, there will be an area where the scanning electrode is selected and the signal electrode is not selected, or an area where the scanning electrode is not selected and the signal electrode is selected (so-called A finite electric field is also applied to the half-selected point °°.

If the difference between the voltage applied to the selected point and the voltage applied to the half-selected point is sufficiently large, and the voltage threshold required to align the liquid crystal molecules perpendicular to the electric field is set to an intermediate voltage value,
Although the display element operates normally, the number of scanning lines (N
), the time during which an effective electric field is applied to one selected point while scanning the entire screen (one frame) (duty ratio) decreases at the rate of force/N.

For this reason, when repeated scanning is performed, the effective voltage difference between selected points and non-selected points becomes smaller as the number of scanning lines increases, resulting in a decrease in image contrast and crosstalk. This is a drawback that is difficult to avoid.

This phenomenon is caused by liquid crystals that do not have bistability (the stable state is when the liquid crystal molecules are aligned horizontally with respect to the electrode surface, and they are aligned vertically only while an electric field is effectively applied). )
This is essentially an unavoidable problem that arises when driving using the temporal accumulation effect (that is, repeatedly scanning).

In order to improve this point, voltage averaging method, dual-frequency driving method, multiple matrix method, etc. have already been proposed, but all of these methods are insufficient, and it is necessary to increase the screen size and density of display elements. Currently, the number of scanning lines has reached a plateau due to the inability to increase the number of scanning lines sufficiently.

To improve the drawbacks of conventional liquid crystal devices, the use of bistable liquid crystal devices is proposed by Clark (C1
ark) and Lagerwall (Japanese Unexamined Patent Publication No. 107216/1983,
(U.S. Pat. No. 4,367,924, etc.).

As the bistable liquid crystal, a ferroelectric liquid crystal having a chiral smectic C phase (S+++fl:' phase) or H phase (SmH'' phase) is generally used.

This ferroelectric liquid crystal has a bistable state consisting of a first optically stable state and a second optically stable state in response to an electric field, and therefore is different from the optical modulation element used in the above-mentioned TN type liquid crystal. Differently, for example, the liquid crystal is oriented in a first optically stable state with respect to one electric field vector, and the liquid crystal is oriented in a second optically stable state with respect to the other electric field vector. Furthermore, this type of liquid crystal has a property (bistability) of taking one of the above two stable states in response to an applied electric field and maintaining that state when no electric field is applied.

In addition to the above-mentioned feature of bistability, ferroelectric liquid crystals have the excellent feature of high-speed response. This is because the spontaneous polarization of the ferroelectric liquid crystal and the applied electric field directly act to induce a transition in the orientation state, which is 3 to 4 orders of magnitude faster than the response speed due to the effect of the dielectric anisotropy and the electric field.

In this way, ferroelectric liquid crystals potentially have extremely excellent properties, and by utilizing these properties, many of the problems of conventional TN-type devices mentioned above can be solved, which is quite essential. Improvement can be obtained. In particular, it is expected to be applied to high-speed optical shutters and high-density, large-screen displays. For this reason, extensive research has been conducted on liquid crystal materials with ferroelectric properties, but the ferroelectric liquid crystal materials developed to date have sufficient characteristics for use in liquid crystal devices, including low-temperature operation characteristics and high-speed response. It is difficult to say that it is equipped with the following.

There exists a relationship between the response time τ, the magnitude of spontaneous polarization Ps, and the viscosity η as expressed by the following formula [n] (where E is the applied electric field). Therefore, in order to increase the response speed, (a) increase the magnitude of the spontaneous polarization Ps (b) increase the viscosity η
There is a method of increasing the applied electric field E. The applied electric field has an upper limit because it is driven by an IC or the like, and it is desirable that it be as low as possible.

Therefore, it is actually necessary to reduce the viscosity η or increase the value of the spontaneous polarization Ps.

- In ferroelectric chiral smectic liquid crystal compounds with numerically large spontaneous polarization, the internal electric field of the cell caused by the spontaneous polarization is also large (there is a tendency for there to be more restrictions on device configurations that can take a bistable state.

Moreover, even if the spontaneous polarization is increased unnecessarily, the viscosity tends to increase accordingly, and as a result, it is conceivable that the response speed will not become very fast.

Furthermore, if the actual operating temperature range for a display is, for example, 5 to 40 degrees Celsius, the response speed will generally change by about 20 times, which is currently beyond the limits of adjustment by drive voltage and frequency. be.

As mentioned above, in order to put ferroelectric liquid crystal elements into practical use, a ferroelectric chiral smectic liquid crystal composition that has low viscosity, high-speed response, and small temperature dependence of response speed is required. ing.

[Problems to be Solved by the Invention] An object of the present invention is to provide a liquid crystal composition having a fast response speed and reduced temperature dependence of the response speed, in order to make a ferroelectric liquid crystal element practical. In particular, it is an object of the present invention to provide a ferroelectric chiral smectic liquid crystal composition and a liquid crystal element using the liquid crystal composition.

[Means for Solving the Problem] and [Operation] That is, the first invention of the present invention is a liquid crystal compound represented by the following general formula (I).

General formula (I) (wherein, R1 is a linear or branched alkyl group that may have a substituent having 1 to 18 carbon atoms, Xl is a single bond, or 10-1X2 is a fluorine atom or (represents a hydrogen atom; n represents O to 8, m represents 1 to 18).Furthermore, the second invention is characterized in that it contains at least one kind of liquid crystalline compound represented by the general formula (I). This is a ferroelectric chiral smectic liquid crystal composition.

Furthermore, a third invention is characterized in that a ferroelectric chiral smectic liquid crystal composition containing at least one liquid crystal compound represented by the general formula (I) is disposed between a pair of electrode substrates. It is a liquid crystal element.

The present invention will be explained in detail below.

In the liquid crystalline compound represented by the general formula (I), R
1 is a linear or branched alkyl group which may have a substituent having 1 to 18 carbon atoms, and is preferably selected from the following (i), (ti), and (iii). is desirable.

(i) An n-alkyl group having 1 to 18 carbon atoms, more preferably an n-alkyl group having 3 to 14 carbon atoms.

(ii) ? 1゜ 1←H2÷``zuH-C1H,,,.

(p is an integer from 0 to 7, and q is an integer from 1 to 9. However, optical activity is excluded.) (fit)? 1゜-(-CH2-h-CH-(-CH2㎇HC-H2-+
(r is an integer from 0 to 7, S is 0 or 1, and t is an integer from 1 to 14. However, optical activity is excluded.) In addition, Xl is a single bond, or -0-1X2 is a fluorine atom or a hydrogen atom. shows.

n is 0 to 8, preferably 0 to 2, and particularly when xI is a single bond, n is preferably 1 or 2. Also, m is 1
~18.

Furthermore, Japanese Patent Application No. 63-27451, Japanese Patent Application Laid-open No. 1-10
The compound represented by the general formula disclosed in Publication No. 4031 is a compound having a phenylpyrimidine skeleton and a polyfluoroalkyl group. However, the former is limited to chiral compounds, and the latter is limited to esters as the bond between the skeleton and the polyfluoroalkyl group, and there are no actual examples of chemical compounds with a phenylpyrimidine skeleton. Furthermore, there is no indication of any specific effects of using this compound.

On the other hand, it has been found that the ferroelectric liquid crystal composition containing the liquid crystal compound represented by the general formula (I) of the present invention has a fast response speed and a reduced temperature dependence of the response speed.

Next, a general synthesis example of the liquid crystalline compound represented by the general formula (I) will be shown below.

In general formula (I), ■When X1 is 10- ■When X1 is a single bond CpC-+CH2+T-r-+CF2÷m X282N
(Tanuki CH2 publication → CFz product

(I -2) (■ (I (I -5) (I -6) (I (I -8) (■ (I -11 (■ (I -13 (I -15) (I -17 (I -18) (I (■ (I -22 (■ (I (I) (I (I (I -38 (■ (I -40 (I -41 (I -42) (■ (I -44 (I -45 (I -46) It can be obtained by mixing at least one of the liquid crystal compounds shown and one or more other liquid crystal compounds in an appropriate ratio.

Further, the liquid crystal composition according to the present invention is a ferroelectric liquid crystal composition,
In particular, ferroelectric chiral smectic liquid crystal compositions are preferred.

Next, specific examples of other liquid crystalline compounds used in the present invention are shown by the following general formulas (m) to (kari).

e: O or 1° f: 0 or 1° However, e+f=0 or 1 Y': H.

halogen.

CH.

C.F.

(IIT) As a preferred compound of the formula: below (Hla) (Illd).

(IV) I h: O or l.

However, g+h=1 1: 0 or 1 (rv) As a preferred compound of the formula: below (IV　a　) (IVc) is mentioned.

j: 0 or 1 Y,', Y2', Y,': H, halogen,
Preferred compounds of the formula CH3,CF2(V) include (Va) (vb) below.

(Vl) k+f! + m: O or l, but +j2
+m=0.1 or 2 (Vl) Preferred compounds of the formula include (VT a ) (Vlf) below.

R,'X,'→E)-X,'℃Htoxz'R2'(
Vla) R+ 'X I'u L'+L'Ra'
(Vlb) R,'x,'5 x4' +x 2'R2'(Vl
d) R,'x,'c)(Xx,'+x2'R2'(VIe) R,'X1'!Xi'(X2'R2'(Vlf)) Here, R+' and R2' are the number of carbon atoms 1 to 18 linear or branched alkyl groups, and one or more non-adjacent -CH2- groups in the alkyl group are -
It may be substituted with CH halogen-. Furthermore, =CI (excluding the 2- group) directly bonded to x,', x2' may be present. In the case of a halogenated alkyl in which -CH2- groups are substituted with -CH halogen-, R+' or Rt' is not bonded to the ring through a single bond.

R1' and R2' are preferably i) to vii below.
).

i) Straight chain alkyl group CH having 1 to 15 carbon atoms.

-(-CH, mop CH-CqH2q++pro~5,
q: An integer of 1 to 11, optical activity may be used.

CH3 1+cH2+-F-CHCHH2±s 0CtH2t++
r: 0 to 6, s: o, 1, t: an integer of 1 to 14, and optical activity.

u: 0゜ 1, an integer from l to 16, CH.

CHCOCwH2w+1 an integer from 1 to 15, It may be optically active.

vi) N -mark H2÷x-CH-CsH2a-+ A: 0-2, B: an integer from 1 to 15, It may be optically active.

vii) C: 0-2, D: an integer from 1 to 15, It may be optically active.

(nl a) ~ As a more preferable compound of (md), the following of record (ITI aa) (III dc) can be mentioned.

U (rVa)~ As a more preferable compound of (rVc), the following of record (IVaa) (rVcd) can be mentioned.

(Va)～ More preferable compounds of (vb) include the following: of record (Vaa) (V bf) can be mentioned.

R,'()(pregnancy R2' (Vaa) R,'+CH,CH2+R2' 'sha CH, CH2C0+R, i' R+'+CH=CHCO+R2' Ha R,’+CH2O+ R2' (V ad) (Vae) (Vaf) (Vag) V-’ (Vl　a　　)〜 As a more preferable compound of (VIf), the following of record (Vlaa) (Vlfa) can be mentioned.

R,'8CH20 and HtoR2' (Vlab) E: 0 or l (■) F.

Goo or 1 (■) As a preferred compound of the formula: below (■a) (■b) is mentioned.

(■) As a preferred compound of the formula: below (■a) (■b) is mentioned.

(■a) As a more preferable compound of (■b), the following of record (■aa) (■bb) can be mentioned.

Here, Rs and R4' are linear or branched alkyl groups having 1 to 18 carbon atoms, and one or more non-adjacent -CH2- groups in the alkyl group are -CH halogen- may be replaced by Furthermore, one or more non-adjacent -CH2- groups other than one CH2- group directly bonded to x, ', x2' may be bonded. However, when R3 or R4 is a halogenated alkyl group in which one -CH2- group is substituted with -CH halogen-, R3' or R4 is not bonded to the ring through a single bond.

Furthermore, Ra' and R-' preferably represent the following i) to
vii).

i) Straight chain alkyl group Ha having 1 to 15 carbon atoms -((,H,÷,CH-C1[2,,.

p: 0-5, q: an integer from 1 to 11, It may be optically active.

tit) Ha -(-CI, +-F-CH-(-CH, -10ctE1
．． T.

r: o to 6, s: o, 1, t: an integer of 1 to 14, and optical activity.

iv) -1-CH, ÷rrcHcvH2v*1U:O.

1. an integer from 1-16, ■) An integer between wl and 15 and optical activity may be used.

vi) N -+cH2÷17CH-CJiB-1 A: O~2, B: an integer from 1 to 15, It may be optically active.

vii) N -(-CH, ÷rC-CoH2o++ H3 C: O~2, D= an integer from 1 to 15, It may be optically active.

Rs ' -X + ' +X 3'←1'-X4'
> X-◎+y
X) (XI) (■) Preferred compounds of the formula include (IX a ) (IXc) below.

R6'-X+'-AI'+X2'-Ra'(rXa)(rx'b) (IXc) Preferred compounds of formula (X) include the following (Xa)(x
b).

R5'-X+'-A+'+X5' (Sawa X2'-Re'R
a'-X+'+A,'(Sawax2/-R6/R6'-X
+'-All'+x4'Xt'-Ra' (Xa) Rs'-X, '-A2'-X3' W X2'-Re'
(xb) More preferable compounds of (DCa) to (■c) include the following (IXaa) to (IXcc).

R5'A1'shaR6' (IXaa) R6'-A, '+0C-R,'HaR5' -〇-A, '+R,'Rs'-A,'() (Sawa R6'R5'-o- A, '()℃Sawa Ra'Rs'-A+'WQC-Re' Iris R5'-AI'+oc+R6' Ha Rs' -A +' +OCH2+Rs 'R5'
+A1'+R6'Rs'+A+'+OR6' (IXac) (IXad) (rXba) (rX bb) (IXbc) (IXbd) (IXbe) (IXca) (IXcb) (Xa).

As a more preferable compound of (Xb), the following of record (X aa) (xbb) can be mentioned.

R5'-A2' +0CR2 building R6' (Xac) R5'-A2'()(XRs' (X ba) (XI) As a more preferable compound of below (Xla) (X1g) is mentioned.

here, R5 Re' is a linear chain having 1 to 18 carbon atoms or a branched alkyl group, The alkyl group O X inside.

-CH2- directly bonding to x2' one excluding group or two or more non-adjacent -CH2 groups, may have been done.

Furthermore, R5'.

Re' is Preferably the following i) ~vi) can be mentioned.

i) Straight chain alkyl group having 1 to 15 carbon atoms ii) CH.

1+CH2÷, CH-C,H2,.

: 0-5, q: an integer from 1 to 11, It may be optically active.

iii)? 1. One mark H2+F-CH-+CH2+TOC1H2,. 1r
: 0 to 6, s: 0°■, t: an integer of 1 to 14, optical activity may be used.

CH3 C:HCOCwH2W, 1 w: an integer from 1 to 15, It may be optically active.

N 1←H2÷17CH−CaH2＋++ A: 0-2, B: an integer from 1 to 15, It may be optically active.

N -H2+l7C-CoH2I,+, CH.

0-2, D= an integer from 1 to 15, It may be optically active.

The liquid crystal compound of the present invention and one or more other liquid crystal compounds or a liquid crystal composition containing the same (these may be ferroelectric liquid crystal compounds and ferroelectric liquid crystal compositions.Hereinafter, these will be referred to as liquid crystal compounds. The compounding ratio of the liquid crystal compound according to the present invention is preferably 1 to 500 parts by weight per 100 parts by weight of the liquid crystal material.

In addition, when using two or more types of liquid crystalline compounds of the present invention, the blending ratio with the liquid crystal material is 1 to 500 parts by weight of the mixture of two or more types of liquid crystalline compounds according to the present invention per 100 parts by weight of the above-mentioned liquid crystal material. It is desirable to do so.

FIG. 1 is a schematic cross-sectional view showing an example of a liquid crystal element having a ferroelectric liquid crystal layer of the present invention, for explaining the structure of the ferroelectric liquid crystal element.

In FIG. 1, 1 is a ferroelectric liquid crystal layer, 2 is a glass substrate, 3 is a transparent electrode, 4 is an insulating alignment control layer, 5 is a spacer, 6 is a lead wire, 7 is a power source, 8 is a polarizing plate, 9 indicates a light source.

The two glass substrates 2 are each made of In20a+SnO.
7 or ITO (indium tin oxide;
A transparent electrode 3 made of a thin film such as Indium Tin Oxide is coated thereon. Thereon, a thin film of a polymer such as polyimide is rubbed with gauze or acetate flocked cloth to form an insulating alignment control layer 4 in which the liquid crystals are aligned in the rubbing direction. Further, as an insulating material, for example, silicon nitride, silicon carbide containing hydrogen, silicon oxide, boron nitride, boron nitride containing hydrogen, cerium oxide, aluminum oxide, zirconium oxide, zirconium oxide, etc. An inorganic insulating layer such as magnesium fluoride is formed, and then polyvinyl alcohol, polyimide, polyamideimide, polyesterimide, polyvalaxylene, polyester, polycarbonate, polyvinyl acecool, polyvinyl chloride, polyvinyl acetate,
The insulating alignment control layer 4 may be formed of two layers using an organic insulating material such as polyamide, borisdylene, cellulose resin, melamine resin, urea resin, acrylic resin, or photoresist resin as the alignment control layer, or an insulating alignment control layer 4 made of an insulating material such as an inorganic material. It may be an insulating orientation control layer or a single layer of an organic material insulating orientation control layer. If this insulating alignment control layer is inorganic, it can be formed by a vapor deposition method, or if it is organic, it can be formed by a solution containing an organic insulating material or its precursor solution (with a solvent of 0.1 to
20% by weight, preferably 0.2 to 10% by weight), spinner coating method, dip coating method, screen printing method,
It can be applied by a spray coating method, a roll coating method, etc., and then cured and formed under predetermined curing conditions (for example, under heating).

The layer thickness of the insulating orientation control layer 4 is usually 30 to 1 μm, preferably 30 to 3000, more preferably 50 to 1 μm.
1000 people is suitable.

These two glass substrates 2 are kept at an arbitrary distance by a spacer 5. For example, there is a method in which silica beads or alumina beads having a predetermined diameter are used as spacers and sandwiched between two glass substrates, and the periphery is sealed using a sealing material, such as an epoxy adhesive. In addition, a polymer film or glass fiber may be used as a spacer.

A ferroelectric liquid crystal is sealed between these two glass substrates.

The ferroelectric liquid crystal layer 1 containing ferroelectric liquid crystal is generally 0.5 to 20 μm, preferably 1 to 5 μm.

In addition, this ferroelectric liquid crystal exhibits a SmC" phase (chiral smectic C phase) in a wide temperature range including room temperature (especially on the low temperature side).
It is desirable to have high-speed response. moreover,
It is desired that the temperature dependence of the response speed be small and that the driving voltage margin be wide.

In addition, especially when used as an element, in order to exhibit good uniform alignment and obtain a monodomain state, the ferroelectric liquid crystal must be changed from an isotropic phase to a ch phase (cholesteric phase) to a 3mA phase (smectic phase) to a SmC phase. It is desirable to have a phase dislocation series called "phase (chiral smectic C phase)".

The transparent electrode 3 is connected to an external power source 7 by a lead wire.

Further, a polarizing plate 8 is bonded to the outside of the glass substrate 2.

The device shown in FIG. 1 is of a transmission type, so it is equipped with a light source 9.

FIG. 2 schematically depicts an example of a cell for explaining the operation of a ferroelectric liquid crystal element. 21a and 21b are In20i, 5nOz or ITO (In
A substrate (glass plate) coated with a transparent electrode made of a thin film such as dium-Tin oxide), between which a liquid crystal molecular layer 22 is oriented perpendicular to the glass surface.
(: "phase or SmH" phase liquid crystal is enclosed. The thick line 23 represents the liquid crystal molecule, and this liquid crystal molecule 23 has a dipole moment (
Pl) has 24. When a voltage higher than a certain threshold is applied between the electrodes on the substrates 21a and 21b, the helical structure of the liquid crystal molecules 23 is unraveled, and the dipole moment (P) is
The alignment direction of the liquid crystal molecules 23 can be changed so that all of the liquid crystal molecules 24 are oriented in the direction of the electric field. The liquid crystal molecules 23 have an elongated shape and exhibit refractive index anisotropy in the long axis direction and the short axis direction. Therefore, for example, if crossed Nicol polarizers are placed above and below the glass surface, the voltage application polarity can be changed. It is easily understood that the liquid crystal optical modulation element has optical characteristics that change depending on the amount of the liquid crystal.

The liquid crystal cell preferably used in the optical modulation element of the present invention has a sufficiently thin thickness (for example, 1Oμ or less).
can do. As the liquid crystal layer becomes thinner in this way, the helical structure of the liquid crystal molecules unwinds even when no electric field is applied, as shown in Figure 3, and the dipole moment Pa or pb is directed upward (34a) or downward (34).
Either state b) is taken. In such a cell, the third
As shown in the figure (when an electric field Ea or Eb of different polarity above a certain threshold value is applied by the voltage applying means 31a and 31b, the dipole moment is directed upward 34a or downward 34b corresponding to the electric field vector of the electric field Ea or Eb. The liquid crystal molecules are oriented in either the first stable state 33a or the second stable state 33b according to the direction change.

As mentioned earlier, there are two advantages to using such a ferroelectric liquid crystal element as an optical modulation element.

The first is that the response speed is extremely fast, and the second is that the alignment of liquid crystal molecules has bistability. To further explain the second point, for example with reference to FIG. 3, the electric field Ea
When the voltage is applied, the liquid crystal molecules are aligned in a first stable state 33a, and this state remains stable even when the electric field is turned off. When an electric field Eb in the opposite direction is applied, the liquid crystal molecules are oriented to a second stable state 33b and change their orientation, but they remain in this state even after the electric field is turned off. Further, as long as the applied electric field Ea or Eb does not exceed a certain threshold value, the previous orientation state is maintained.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Production of 5-n-decyl-2-[4-(1,1-dihydroperfluorobutyloxy)phenyl]pyrimidine (Exemplary Compound No. I-20) 5-n-decyl- 2-(4
-hydroxyphenyl)pyrimidine 0.3g (9,6
mmoj') and 2.89 g of 1,1-dihydroperfluorobutyl p-toluenesulfonate (8,2 mmo#
), and 20 mp of an n-butanol solution in which 0.95 g of potassium hydroxide was dissolved was added dropwise to the solution, and the mixture was heated under reflux for 7 hours. After the reaction was completed, 500 mf of saturated brine was added and extracted with isopropyl ether. Anhydrous sodium sulfate was added to the extract, and after drying, the solvent was distilled off. 3.4 g of the obtained crude crystals were subjected to column chromatography (n-
The product was purified by hexane/ethyl acetate=6/1) and recrystallization (ethanol) to obtain 1.6 g of the desired product.

Phase transition temperature ('C) 14.2 2! J, 3 5'
/, U Example 2 Preparation of 5-n-decyl-2-[4-(1,1,2,2-tetrahydroperfluorodecyloxy)phenyl]pyrimidine (exemplified compound No. 1-35) n-butanol 50 mj? 2.77 g of 5-n-decyl-2-(4-hydroxyphenyl)pyrimidine (8,9 mmoj
5.50 g of 1,1,2,2-tetrahydroperfluorodecyl p-toluenesulfonic acid (8,9 mmoj>
), and 20 mj+ of an n=butanol solution in which 0.88 g of potassium hydroxide was dissolved was added dropwise to the solution, and 17
The mixture was heated to reflux for an hour. After the reaction is complete, add 500 mp of saturated saline solution.
was added and extracted with isopropyl ether. Anhydrous sodium sulfate was added to the extract, and after drying, the solvent was distilled off, and 3.0 g of the obtained crude crystals were purified by column chromatography (n-hexane/isopropyl ether = 5/1) to obtain the desired product. 3g was obtained.

phase transition temperature (’C) Example 3 Mix the following compounds in the following parts by weight, liquid crystal composition I created object A.

Furthermore, for this liquid crystal composition A, exemplified compounds No.
Liquid crystal composition B was prepared by mixing 1-20 in the weight parts shown below.

Exemplary Compound No. Structural Formula Parts by Weight Liquid Crystal Composition A This exhibits the following phase transition temperature (''C).

10.4 55.0 65.5
76.6Cryst,,-n5lll(:”-nSmA
-nCh-)Is o.

Example 4 Two glass plates with a thickness of 0.7 mm were prepared, an ITO film was formed on each glass plate, and a voltage application electrode was created.
Furthermore, SiO□ was vapor-deposited on top of this to form an insulating layer. Silane coupling agent [manufactured by Shin-Etsu Chemical, KBM] on the glass plate
-602] A 0.2% isopropyl alcohol solution was applied for 15 seconds using a spinner with a rotation speed of 200 Or, p, m, to perform surface treatment. Thereafter, a heat drying treatment was performed at 120° C. for 20 minutes.

Furthermore, a polyimide resin precursor [manufactured by Toshi ■, 5P-510] was applied on a glass plate with a surface-treated ITO film.
Rotate 1.5% dimethylacetamide solution at 200 or
, p, m, spinner for 15 seconds. After the film was formed, a heating condensation firing process was performed at 300° C. for 60 minutes.

The thickness of the coating film at this time was approximately 250.

This fired coating was rubbed with acetate flocked cloth, then washed with isopropyl alcohol solution, and alumina beads with an average particle size of 2 μm were sprinkled on one glass plate, so that the rubbing axes of each plate were aligned with each other. Glue the glass plates together using an adhesive sealant (manufactured by Chisso ■, Rixon Bond) so that they are parallel to each other for 60 minutes.
A cell was prepared by heating and drying at 100°C.

The liquid crystal composition B mixed in Example 3 was injected into this cell in an isotropic liquid state and slowly cooled from the isotropic phase to 25°C at 20°C/h to produce a ferroelectric liquid crystal element. The cell thickness of this cell was measured using a Bereck phase plate and was found to be approximately 2 μm.

Using this ferroelectric liquid crystal element, the magnitude of spontaneous polarization Ps and the peak-to-peak voltage Vpp" are applied to a voltage of 20V to produce an optical response under crossed Nicols (change in amount of transmitted light from 0 to
90%) to measure the response speed (hereinafter referred to as optical response speed). The results are shown below.

Example 5 Mix the following compounds in the following parts by weight, liquid crystal composition Object C was created.

Structure 1 YO Formula C9H+oO+ 0CH2噸) (Toc7HIBυ) Furthermore, the following exemplified compounds were mixed with the liquid crystal composition C in the weight parts shown below to prepare a liquid crystal composition.

Exemplary compound No. Structural formula Part by weight Liquid crystal composition C90 All examples except for injecting the liquid crystal composition into the cell Example 4
A ferroelectric liquid crystal device was created using the same method as described above, and the optical response speed was measured.

The results are shown below.

10 °C 25 °C 40 °C Response speed (gsec) 630 322 174 Comparative Example 1 Ferroelectric liquid crystal was prepared in the same manner as in Example 4, except that the liquid crystal composition C mixed in Example 5 was injected into the cell. A device was created and the optical response speed was measured.

The results are shown below.

10℃ 25℃ 40℃Response speed (
5ec) 784 373 197 Example 6 Exemplary compound No. I-4, l-14 used in Example 5
, l-20, the following exemplary compounds were mixed in the weight parts shown below to prepare liquid crystal composition E.

Exemplary Compound No. Structural Formula Weight Parts Liquid Crystal Composition C90 A ferroelectric liquid crystal element was prepared in the same manner as in Example 4, except that this liquid crystal composition E was used. The optical response speed was measured.

The measurement results are shown below.

10℃ 25℃ 40℃Response speed (
Color 5ec) 625 321 175 Example 7 Exemplary compound No. used in Example 5, I-4, 1-14
, l-20, the following exemplary compounds were mixed in the weight parts shown below to prepare a liquid crystal composition F.

Exemplified Compound No. Structural Formula Weight Parts Liquid Crystal Composition C8g Except for using this liquid crystal composition F, a ferroelectric liquid crystal element was prepared in the same manner as in Example 4; The optical response speed was measured.

The measurement results are shown below.

10℃ 25℃ Response speed (le 5ec) 642 33440
℃ Example 8 The following compounds were mixed in the following parts by weight to prepare a liquid crystal composition G.

Structural formula % Formula % Further, the following exemplary compounds were mixed with the liquid crystal composition G in the weight parts shown below to prepare a liquid crystal composition H.

Exemplary Compound No. Structural Formula Weight Parts Liquid Crystal Composition G 92 Except for injecting Liquid Crystal Composition H into the cell, all <Example 4>
A ferroelectric liquid crystal device was created using the same method as described above, and the optical response speed was measured.

The results are shown below.

10℃ 25℃ 40℃Response speed (
Il, 5ec) 541 270 141
Comparative Example 2 A ferroelectric liquid crystal element was prepared in the same manner as in Example 4, except that the liquid crystal composition G mixed in Example 8 was injected into the cell, and the optical response was determined in the same manner as in Example 1. The speed was measured.

The results are shown below.

10℃ 25℃ 40℃ Response speed 5ec) 653 317 1
59 Example 9 Exemplary compound No. I-7, l-30 used in Example 8
Instead, the following exemplified compounds were mixed in the weight parts shown below to prepare liquid crystal composition (2).

Exemplified Compound No. Structural Formula Weight Parts Liquid Crystal Composition G 90 Except for using this liquid crystal composition, a ferroelectric liquid crystal element was prepared in the same manner as in Example 4; The optical response speed was measured.

The measurement results are shown below.

10℃ 25℃ 40℃ Response speed (psec) 558 285
147 Example 10 Exemplary compound No. used in Example 8, I-7, l-30
Instead, liquid crystal composition J was prepared by mixing the following exemplified compounds in the weight parts shown below.

Exemplary compound No.

Structural formula % Formula % (1 Except for using this liquid crystal composition, a ferroelectric liquid crystal element was prepared in the same manner as in Example 4, and the optical response speed was measured in the same manner as in Example 4. .

The measurement results are shown below.

10℃ 25℃ 40℃ Response speed (p, 5ec) 555 286
145 Example 11 Exemplary compound No., r-1, l-30 used in Example 8
Instead, liquid crystal composition K was prepared by mixing the following exemplified compounds in the weight parts shown below.

Exemplary compound no.

Structural formula % Formula % A ferroelectric liquid crystal element was prepared in the same manner as in Example 4 except that this liquid crystal composition was used, and the optical response speed was measured in the same manner as in Example 4.

The measurement results are shown below.

10℃ 25℃ 40℃ Response speed (le 5ec) 562 291
153 Example 12 The following compounds were mixed in the following parts by weight to prepare a liquid crystal composition.

Further, to this liquid crystal composition, the following exemplified compounds were mixed in the weight parts shown below to prepare a liquid crystal composition M.

Exemplary compound No. Structural formula Part by weight Liquid crystal composition L All except for injecting liquid crystal composition M into the cell <Example 4>
A ferroelectric liquid crystal device was fabricated using the same method as above, the optical response speed was measured, and the switching state etc. were observed. The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

10℃ 25℃ 40℃ Response speed (le 5ec) 562 299
165 Comparative Example 3 A ferroelectric liquid crystal element was prepared in the same manner as in Example 4 except that the liquid crystal composition mixed in Example 12 was injected into the cell, and the optical response speed was measured.

The results are shown below.

10 ℃ 25 ℃ 40 ℃ Response speed (le 5ee) 668 340 182
Example 13 Exemplary compound No., I-2, I25 used in Example 12
, l-37, the following exemplary compounds were mixed in the weight parts shown below to prepare liquid crystal composition N.

Exemplified Compound No. Structural Formula Weight Parts Liquid Crystal Composition L 91 A ferroelectric liquid crystal element was prepared in the same manner as in Example 4, except that this liquid crystal composition was used. The optical response speed was measured and the switching state etc. were observed. The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

10℃ 25℃ 40℃ Response speed (psec) 558 300
167 Example 14 Exemplary compound No., I-2, I25 used in Example 12
, l-37, the following exemplary compounds were mixed in the weight parts shown below to prepare liquid crystal composition O.

Exemplified Compound No. Structural Formula Weight Parts Liquid Crystal Composition L 92 A ferroelectric liquid crystal element was prepared in the same manner as in Example 4, except that this liquid crystal composition was used. The optical response speed was measured and the switching state etc. were observed. The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

10℃ 25℃ 40℃ Response speed (p, 5ec) 583 305
170 As is clear from the results of Examples 5 to 14, the ferroelectric liquid crystal elements containing liquid crystal compositions D to F, H-, and M to 0 according to the present invention have good operating characteristics at low temperatures and high-speed response. It can be seen that the temperature dependence of the response speed has been improved and the temperature dependence of the response speed has also been reduced.

Example 15 In place of the 1.5% dimethylacetamide solution of the polyimide resin precursor used in Example 7, a 2% aqueous solution of polyvinyl alcohol resin (manufactured by Kuraray ■, PUA-117) was used. Create a dielectric liquid crystal element,
The optical response speed was measured in the same manner as in Example 4. The results are shown below.

10℃ 25℃ 40℃ Response speed (xsec) 619 319
171 Example 16 A ferroelectric liquid crystal element was created in the same manner as in Example 4, except that the alignment control layer was created only with polyimide resin without using the 5iOa used in Example 7. The optical response speed was measured in the same manner as above.The results are shown below.

10℃ 25℃ 40℃ Response speed (river 5ec) 611 321
175 As is clear from Example 15.16, even when the device configuration is changed, the device containing the ferroelectric liquid crystal composition according to the present invention has significantly improved low-temperature operating characteristics as in Example 7. , and the temperature dependence of the response speed is reduced.

[Effects of the Invention] As explained above, a device using a ferroelectric liquid crystal composition containing a liquid crystal compound of the present invention has good switching characteristics, a liquid crystal device with improved low-temperature operation characteristics, and a liquid crystal device with improved response. A liquid crystal element with reduced temperature dependence of speed can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a liquid crystal display element using a ferroelectric liquid crystal layer of the present invention, and FIGS. 2 and 3 are examples of an element cell for explaining the operation of a ferroelectric liquid crystal element. FIG. 1... Ferroelectric liquid crystal layer 2... Glass substrate 3...
Transparent electrode 4... Insulating alignment control layer 5... Spacer 6... Lead wire 7... Power supply
8...Polarizing plate 9...Light source I.・・・
・Incoming light■...Transmitted light 21a...Substrate 21b...Substrate 22...
・Liquid crystal molecule layer 23...Liquid crystal molecule 24...Dipole moment (P) 31a, 31b...Voltage application means 33a...First stable state 33b...Second stable state 34a. ...Upward dipole moment 34b...Downward dipole moment Ea...Upward electric field Eb...Downward electric field

Claims (3)

[Claims] (1) A liquid crystal compound represented by the following general formula (I). General formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. Bond or -O-, X_2 represents a fluorine atom or a hydrogen atom. n represents 0 to 8, m represents 1 to 18.) (2) A ferroelectric chiral smectic liquid crystal composition containing at least one liquid crystal compound represented by the following general formula (I). General formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. Bond or -O-, X_2 represents a fluorine atom or a hydrogen atom. n represents 0 to 8, m represents 1 to 18.) (3) A liquid crystal element characterized in that a ferroelectric chiral smectic liquid crystal composition containing at least one liquid crystal compound represented by the following general formula (I) is disposed between a pair of electrode substrates. General formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. Bond or -O-, X_2 represents a fluorine atom or a hydrogen atom. n represents 0 to 8, m represents 1 to 18.)