JPH0429219A - High-polymer liquid crystal composition, liquid crystal optical element formed by using this composition and method for driving liquid crystal optical element - Google Patents

Abstract

PURPOSE:To obtain high-speed responsiveness without impairing an antiferroelectric characteristic and orientability by incorporating at least one kind of low-polymer liquid crystals and high-polymer liquid crystals which consists of low-polymer liquid crystals and high-polymer liquid crystals and exhibit an antiferroelectric liquic crystal phase. CONSTITUTION:This compsn. consists of one or >=2 kinds of the low-polymer liquid crystals and one or >=2 kinds of the high-polymer liquid crystals and contain >=1 kinds of the low-polymer liquid crystals or high-polymer liquid crystals exhibiting the antiferroelectric characteristic. The liquid crystal optical element is formed by holding this high-polymer liquid crystal compsn. 4 in place between two sheets of electrodes 3 and 5 facing each other and has the antiferroelectric characteristic and, therefore, the distinct plural stable states are obtd. and since the element contains the high-polymer liquid crystal, the element has the excellent orientability of the liquid crystal molecules. The high-speed responsiveness with an electric field change is obtd. in this way without imparing the antiferroelectric characteristic and orientability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a polymeric liquid crystal composition suitably used as a liquid crystal material for liquid crystal display elements, liquid crystal memory elements, liquid crystal acoustic elements, and the like. The present invention also relates to a liquid crystal optical element using the same. Furthermore, the present invention relates to a method of driving the liquid crystal optical element.

[Prior Art] An optical element in which a liquid crystal is sandwiched between two substrates by utilizing the optical anisotropy of a ferroelectric liquid crystal has been proposed by Clark and Lagerhal (Japanese Unexamined Patent Publication No. 107216/1982). , Japanese Unexamined Patent Publication No. 153521/1983). These methods reduce the distance between the substrates sufficiently to eliminate the helical structure of the chiral smectic C phase, resulting in two stable states B (so-called bistability).
It is an attempt to obtain. However, in order to fabricate such an optical element, an alignment film must be provided on the substrate, and this alignment film also poses the problem that it is difficult to obtain the clear bistability that was originally thought. .

In recent years, M HP OB C[4-(1-IIletyl
heptyloxycarbonyl)pheny! −
4'-octyloxy biphenyl-4-c
It was confirmed that a liquid crystal called arboxylate has a royal property that was not seen in conventional ferroelectric liquid crystals (Jpn, J, Appl, Phys, 27
(1988), L729).

In addition, this liquid crystal is antiferroelectric (15th Liquid Crystal Symposium Proceedings 3A21 (1989), P310
) and the ability to manufacture display devices using liquid crystals that exhibit antiferroelectricity and drive them using a method different from conventional bistable drive (15th Liquid Crystal Symposium Proceedings 3A23 (1989) , P314, JP-A-1-2
13390, JP-A-1-316367, JP-A-2-28128), etc., and the possibility of overcoming the problems of bistable drive was shown.

However, since the liquid crystal used is a low molecular liquid crystal,
Problems remain, such as (1) requiring an alignment film as in the past, and (2) difficulty in obtaining uniform alignment over a large area.

On the other hand, in order to improve the alignment of low-molecular-weight liquid crystals and obtain uniform alignment over a large area, it is better to make ferroelectric liquid crystals into polymers, and when mixed with low-molecular-weight liquid crystals, responsiveness will not be impaired. It has been discovered that
No. 88, JP-A No. 63-284291). On the other hand, similar effects have been obtained with a composition in which a ferroelectric low-molecular liquid crystal is mixed with a high-molecular liquid crystal (Japanese Patent Laid-Open No. 64-6628
Publication No. 7).

However, since liquid crystal elements using these compositions are also driven using the bistability of liquid crystal molecules, the problem remains that clear bistability is difficult to obtain.

[Problem to be solved by the invention]

The present invention aims to provide a polymeric liquid crystal composition that has a plurality of distinct stable states and can provide high-speed response without impairing antiferroelectricity or orientation.

Another object of the present invention is to use the polymer liquid crystal composition to obtain a liquid crystal optical element that does not require an alignment film and can obtain uniform alignment of liquid crystal molecules over a large area.

A further object of the present invention is to provide a method for driving a liquid crystal optical element that can stably drive the liquid crystal optical element using the third state, instead of unstable driving using conventional bistable driving. .

[Means to solve the problem]

As a result of intensive research to solve the above-mentioned problem, the present inventors discovered that the object could be achieved by a polymeric liquid crystal composition exhibiting an antiferroelectric liquid crystal phase, and based on this knowledge, the present invention was developed. The invention was completed.

That is, the present invention provides one or more types of low-molecular liquid crystals and one
The present invention provides a polymeric liquid crystal composition comprising one or more types of polymeric liquid crystals, characterized in that at least one type of low-molecular liquid crystal or polymeric liquid crystal exhibits antiferroelectricity.

The polymer liquid crystal composition of the present invention is a polymer liquid crystal composition having antiferroelectricity. Since it has antiferroelectricity, it is possible to obtain a plurality of distinct stable states. Furthermore, since it contains polymeric liquid crystal, it has excellent orientation of liquid crystal molecules. Furthermore, since it is a polymeric liquid crystal composition mixed with a low-molecular liquid crystal, it is possible to obtain high-speed response to electric field changes without impairing antiferroelectricity and orientation.

Such polymer liquid crystal compositions include: (1) a low molecular liquid crystal or low molecular liquid crystal composition containing one or more types of low molecular liquid crystals exhibiting antiferroelectricity and one or more types of polymer liquid crystals or polymer liquid crystals; a polymer liquid crystal composition consisting of a composition, (i) a polymer liquid crystal or polymer liquid crystal composition containing one or more types of polymer liquid crystal exhibiting antiferroelectricity and one or more types of low molecular liquid crystal or low molecular liquid crystal composition; Examples include polymeric liquid crystal compositions consisting of Here, the polymer liquid crystal (2) and the low molecular liquid crystal (2) may exhibit antiferroelectricity.

In both cases (1) and (2) above, the amount of the secondary base for the polymeric liquid crystal contained in the polymeric liquid crystal composition is preferably 2 to 95% by weight, particularly preferably 5 to 50% by weight. If the proportion of the polymer liquid crystal is too small, the polymer liquid crystal composition may lack usefulness such as orientation, and if it is too large, the polymer liquid crystal composition may have disadvantages such as slow response to electric field changes. Sometimes it happens. In addition, the proportion of antiferroelectric liquid crystal is 10 to 100 in both cases (1) and (2) above.
It is preferable to set it as weight%, especially 50-100 weight%
It is preferable that If the proportion of antiferroelectric liquid crystal is too small, the composition may not exhibit antiferroelectricity, which may cause problems.

The antiferroelectric liquid crystal polymer used in the present invention is not particularly limited as long as it exhibits antiferroelectricity at an appropriate temperature. Generally, the optically active group and R1 represent an alkyl group or a group containing an ester bond in the alkyl chain. ) is preferred. For example, polymeric liquid crystals having the following repeating units are preferred.

[In the formula, R1 and X are the same as above, and R2 is -H
1CH3 or -Cz)Is, j is an integer from 1 to 20, k
is an integer from 1 to 30, A is 10- or -COO-, wholesale is O
or 1, Y represents -COO- or 10CO-. ) is shown. ] Specifically, for example, liquid crystals (a) and liquid crystals (b) having the following repeating units can be mentioned.

Liquid crystal (a) CH: + n − phase 1” IL orbital [[so: Tokichi phase (liquid), SmA: smectic A phase, 5LIIC”: chiral smectic C phase,
SmCA": indicates antiferroelectric phase, glass state.]Liquid crystal (b) CHl n When a triangular voltage is applied between
This value is determined as the antiferroelectric phase when the phase (three types) is reached.

Also, Examples of low-molecular liquid crystals exhibiting antiferroelectricity include: These include:

n=7-10 ■ Publication No. 0) n=6-12 (1st Proceedings of the 5th LCD Symposium A16 (1989).

n=7 to 10 (1st 5th Liquid Crystal Conference Lecture Proceedings A16 n=7 to 10 (Unexamined Japanese Patent Publication No. 1-213390) n=8 to 10 (142nd Committee on Organic Materials for Information Technology, Japan Society for the Promotion of Science) Association
47th Joint Study Group Material P20) The above compound is an example of a liquid crystal compound having antiferroelectricity, and is not limited to these structural formulas.

Further, as other polymer liquid crystals or low molecular liquid crystals to be mixed with the antiferroelectric low molecular liquid crystal or the antiferroelectric polymer liquid crystal, those exhibiting a smectic phase are preferable. Particularly preferred are those exhibiting a smectic C phase or a chiral smectic C phase.

Examples of such polymer liquid crystals include those that do not contain asymmetric carbon and those that contain asymmetric carbon.

Examples of those containing no asymmetric carbon include the following.

(1) Polymer liquid crystal ACH with polyacrylate main chain
2CH'h (Y.

S.

Freidzon Polymer Common.

1986° 27° Polymer liquid crystal Hff with polymethacrylate main chain (H.

Finkelmann.

Makrow+ol.

Chem, + 1978° Polymer liquid crystal with polyoxirane main chain (C.

Pugh.

Polymer Bulletin 1986° Polymer liquid crystal H3 with polysiloxane main chain (H.

Richard.

Mol.

Cryst.

Liq.

Cryst.

198B.

155° Polymer liquid crystal with polyester main chain (M.

F, ic h MacroIIlo I.

Cheffl,l apid Commun.

■ (Watanabe sequentially, 1st Proceedings of the 4th LCD Symposium, 988. Also, Examples of things containing asymmetric carbon are: below Things can be mentioned.

Polymer liquid crystal containing asymmetric carbon having a polyacrylate main chain Polymer liquid crystal containing asymmetric carbon having a polymethacrylate main chain H3 (J, C, Dubois et al., Mo1. Cry
st, Liq, Cryst, 1986.137
, 349) (3) Polymer liquid crystal containing asymmetric carbon having a polychloroacrylate main chain U, C, Dubois et al., Mo1. Crys
t, Liq, Cryst, 1986, 137
, 349) (4) Polymer liquid crystal containing asymmetric carbon having a polyoxysilane main chain (JP-A-63-264629) (5) Polymer liquid crystal CH containing asymmetric carbon having a polysiloxane main chain.

Publication No. 2) Polymer liquid crystal containing asymmetric carbon with polyester main chain CH.

Publication No. 24) Publication No. 22918) (R.

Zentel et al.

Liq.

Cryst.

1987°2° The polymeric liquid crystal may be a dimer or trimer oligomer liquid crystal.

Furthermore, the polymeric liquid crystal composition of the present invention may contain an adhesive, a thinning agent, a non-liquid crystal chiral compound, a dye, etc., as necessary.

The present invention also provides a liquid crystal optical element characterized in that the polymer liquid crystal composition described above is sandwiched between two opposing electrodes.

FIG. 1 is a sectional view showing an example of the liquid crystal optical element of the present invention.

The liquid crystal optical element of the present invention is formed by sandwiching the polymeric liquid crystal composition 4 between two opposing electrodes 3.5, and usually has a substrate 2.5 on the outside of each electrode 3.5. 6 are provided, and furthermore, on the outside thereof, polarizing plates 1.7 and 1.7 are respectively provided.
is provided.

The electrode 3.5 is not particularly limited as long as it is made of a transparent material. For example, transparent electrodes such as ITO films made of indium oxide or a mixture of indium oxide and tin oxide are suitable, and are usually thinly deposited on the substrate 2.6.
It is processed into an appropriate shape and used.

The substrate 2.6 is not particularly limited as long as it is made of a transparent material. For example, glass, a plastic film such as polyethylene terephthalate (PET), polyether sulfone (PES), polycarbonate (PC), etc. can be used.

The thickness of the substrate is usually preferably 10 μm to several inches.

As the polarizing plate 1.7, a normal one can be used. There is no particular limitation on the direction of each polarization axis, but
In the present invention, which is preferably perpendicular to each other, since the above polymer liquid crystal composition is used, an alignment film is not required between the electrode 3 or 5 and the polymer liquid crystal composition 4. That is, even without an alignment film, liquid crystal molecules can be easily aligned by a shearing method in which shearing is applied to the liquid crystal composition by bending deformation, flexural vibration, or the like. Therefore, it is possible to obtain a liquid crystal optical element in which liquid crystal molecules are uniformly aligned over a large area, which does not require an alignment film like conventional liquid crystal optical elements.

FIG. 2 is an explanatory diagram showing the movement of ferroelectric liquid crystal molecules within a liquid crystal optical element.

8 is a liquid crystal molecule, 9 is a dipole on the liquid crystal molecule 8, and 10 is a cone representing the moving locus of the liquid crystal molecule 8. 3.
5 is an electrode.

In normal ferroelectric liquid crystals, when the cell thickness of the liquid crystal optical element is reduced, the helical structure of the liquid crystal molecules disappears, and the state a or b, where the molecules are parallel to the cell interface, becomes stable as shown in Figure 2. A so-called surface stabilization state is obtained. If state a is a state in which the dipole 9 of the ferroelectric liquid crystal molecules 8 is directed upward, and state b is a state in which the dipole 9 of the ferroelectric liquid crystal molecules 8 is directed downward, the upward electric field is applied to the electrodes 3.5 of the cell.
When the electric field is applied during this period and then the electric field is turned off, all the liquid crystal molecules 8 in the cell are stabilized in the state a. Conversely, if a downward electric field is applied between the electrodes 3.5 of the cell and then the electric field is turned off, b
All liquid crystal molecules 8 within the cell are stabilized in this state.

FIG. 3 is an explanatory diagram of the liquid crystal molecules shown in FIG. 2 viewed from above, and FIG.
) represents the state b in FIG.

As shown in FIGS. 3(a) and 3(b), since the direction in which the liquid crystal molecules 8 are tilted with respect to the smectic layer 1, that is, the optical axis 12, is different between state a and state b, the cell It can be seen that bright and dark display can be achieved by providing polarizing plates in appropriate directions above and below.

The above is a case of a liquid crystal optical element using a ferroelectric liquid crystal, but similarly, in the case of a liquid crystal optical element using an antiferroelectric liquid crystal, the cell thickness is thinned (so that the liquid crystal molecules are parallel to the cell interface). States a and b are stable.However, in the case of a liquid crystal optical element using antiferroelectric liquid crystal, when the electric field is zero, the dipoles between adjacent smectic layers are oriented in opposite directions, that is, the adjacent liquid crystal molecules are tilted. A state in which the directions are mutually opposite to the normal to the smectic layer stably exists.

FIG. 4 is an explanatory diagram showing the state of liquid crystal molecules in a state where the electric field of a liquid crystal optical element using antiferroelectric liquid crystal is zero.

Let this state be C.

In state C, the direction of the optical axis 12 of the liquid crystal molecules is the average direction of all liquid crystal molecules, that is, the direction perpendicular to the smectic layer 11.

5 and 6 are graphs showing the states of liquid crystal molecules with respect to changes in applied voltage in a liquid crystal optical element using ferroelectric liquid crystal and a liquid crystal optical element using antiferroelectric liquid crystal, respectively. The horizontal axis shows the applied voltage (V), and the vertical axis shows the state of the liquid crystal molecules.

Hysteresis exists in the state of liquid crystal molecules in both liquid crystal optical elements using ferroelectric liquid crystals and liquid crystal optical elements using antiferroelectric liquid crystals. In particular, two types of hysteresis exist in liquid crystal optical elements using antiferroelectric liquid crystals.

FIG. 7 is an explanatory diagram showing the directions of the optical axis of the liquid crystal molecules in each state and the polarization axis of the polarizing plate.

As described above, in the liquid crystal optical element using antiferroelectric liquid crystal, the liquid crystal molecules 8 have three stable states, a, b, and C. When the liquid crystal molecules in the cell are oriented, the optical axis 12 in each state is the average direction of the liquid crystal molecules 8, that is, the direction shown in FIG.

In liquid crystal optical elements using such antiferroelectric liquid crystals,
There are two suitable directions for setting the polarization axis when the polarizing plates are set as crossed Nicols. The first direction is a direction in which the state of C is clear and the states of a and b are equivalently bright, that is, as shown in FIG. This is the direction that aligns with the optical axis of the state. The second direction is a direction in which state a is bright, state C is intermediate, and state b is dark, that is, the polarization axis 13 or 14 of crossed Nicols is aligned with the optical axis of state b. The direction is to

In this case, the state a and the state b may be set so that their brightness and darkness are reversed.

8V is a graph showing the transmitted light intensity T when a triangular wave voltage is applied between the electrodes of the liquid crystal optical element, and FIG. If set, the 81st ffi (b) is a case where the polarizing plate is set in the second direction. The horizontal axis shows the voltage (■), and the vertical axis shows the transmitted light intensity T.

In both FIG. 8(a) and FIG. 8(b), the transmitted light intensity T draws a curve in which two bistable hysteresis patterns exist.

Therefore, when a voltage in the form of a pulse wave with two positive and negative biases is applied between the electrodes of the liquid crystal optical element in a temperature range in which the polymeric liquid crystal composition exhibits an antiferroelectric phase, the liquid crystal optical element can be suitably driven. be able to.

FIG. 9 is a graph showing an example of the driving voltage applied between the electrodes of the liquid crystal optical element. The horizontal axis represents time (t), and the vertical axis represents voltage (V).

As shown in FIG. 9, in the temperature range where the polymer liquid crystal composition exhibits an antiferroelectric phase, for example, V
By applying a bias of o and applying a voltage in the form of a pulse wave in the positive and negative directions using this as a reference point, the liquid crystal molecules become bistable between the a state and the C state. Conversely, if you apply a bias of -VO and apply a voltage in the form of a pulse wave in the positive and negative directions using this as a reference point, the liquid crystal molecules will change to state b and state C.
It is bistable between the states.

Therefore, by adjusting the applied bias voltage, it is possible to obtain a liquid crystal optical element that is stable in three states.

When a liquid crystal optical element is driven by such a driving voltage,
When the polarizing plate is set in the above-mentioned first direction, the bright states a and b can be used alternately, so there is an advantage that, on average, no DC component of voltage is applied to the cell. Since the direct current component of the voltage applied to the liquid crystal has an adverse effect on the liquid crystal, such as decomposition and deterioration of the liquid crystal, not having such a component applied to the cell prolongs the life of the liquid crystal optical element. Another advantage is that it is possible to prevent the so-called burn-in effect, in which liquid crystal molecules tend to shift to the a state or the b state, which has been a problem with conventional bistable drive.

When the polarizing plate is set in the second direction, there is an advantage that gradation display of bright, intermediate, and dark, which could not be realized with conventional bistable driving, becomes possible.

As a practical driving pulse voltage, a waveform as shown in FIG. 10 is preferable. In the case of having bistability as shown in FIG. 11(a), when switching to the dark direction by a write pulse exceeding the threshold voltage as shown in FIG. 11(b), Value Voltage ■ Crosstalk occurs due to voltages below 5. Here, the threshold voltage Vth is a voltage necessary to switch to the opposite state, and switching between bright and dark does not occur due to this crosstalk. Similarly, FIG. 8(a) or FIG.
), it is preferable to use a driving pulse voltage as shown in FIG. 10. That is, considering that there are two hysteresis of bistable properties, the base *OV of the bistable pulse waveform (Fig. 11 Q)) is given by ■ in the royal setting. or -V. It is best to apply Hehias to create a shifted waveform. According to the drive pulses shown in FIG. 10, in the liquid crystal optical element shown in FIG. It is switched to the bright state by a write pulse of 3.

〔Example〕

Hereinafter, the present invention will be explained in detail based on Examples, but the present invention is not limited thereto.

Example 1 A required amount of low-molecular liquid crystal A having the following structure and high-molecular liquid crystal B having the following repeating unit was weighed at room temperature, dissolved in a solvent (dichloroethane), and then mixed by evaporating the solvent. A polymer liquid crystal composition was obtained.

Liquid crystal A Liquid crystal B Liquid crystal A Mn-3200: Liquid crystal B = 80:20 (weight%) Cryst 5IIlcA” Sa+A
←−1s.

1: crystal: indicates a crystal phase or solid phase.

] The above polymer liquid crystal composition was sandwiched between two opposing glass substrates with ITO electrodes so that the liquid crystal composition and the ITO electrodes were in contact with each other to obtain a liquid crystal optical element. Here, the ITO electrode area was 15 embryos x 15 foxes, the thickness of the liquid crystal composition was 2 μm, and the liquid crystal composition was sandwiched between glass substrates with ITO electrodes.
The liquid crystal molecules were oriented in one direction by heating to 30° C., then slowly cooling, and applying shearing stress to the liquid crystal composition several times at 118° C. by a soaring method.

Regarding the obtained liquid crystal optical element, the phase transition behavior of the liquid crystal composition was observed using a polarizing microscope, and the above phase transition temperature was determined.

Next, the maximum voltage ±30 shown in FIG. 12 was applied between the ITO electrodes.
When applying a triangular wave voltage with a frequency of 1.25) tz and observing the change in the transmitted light intensity of the liquid crystal optical element under crossed nicol conditions with a photodiode, the intensity changes almost in proportion to the applied voltage in the S mode. A so-called electroclinic effect was observed.

FIG. 13 shows the change in the intensity of transmitted light of the liquid crystal optical element under crossed nicol conditions when a triangular wave voltage is applied at 105°C.

When the change in transmitted light intensity was observed with a photodiode while the temperature was further lowered, it was found that the liquid crystal molecules exhibited tristability between 98°C and 50°C. That is, the antiferroelectric phase (S+s(6”
phase), the transmitted light intensity has a two-step response (tristable),
The phase could be identified from this two-step response. FIG. 14 shows an example of measurement of changes in transmitted light intensity of a liquid crystal optical element under crossed nicol conditions when a triangular wave voltage is applied at 90°C. Here, the setting direction of the cross niffle was a direction in which one polarization axis was rotated by 30° from the state where it coincided with the normal line of the smectic layer. The ratio of transmitted light intensities in the three stable states was 1:15:32, where the dark state was 1.

In addition, when we measured the polarization reversal current when a triangular wave voltage with a maximum voltage of ±30V was applied between the electrodes at 90°C, we found that the polarization caused by the reversal of the dipole of the liquid crystal molecules, as shown in Figure 15. Two peaks of reversal current were observed, and it was confirmed that this phase was an antiferroelectric phase.

Further, the degree of orientation of liquid crystal molecules of the obtained liquid crystal optical element was measured under crossed nicols set in the above direction, and was found to be about 70. This means that the degree of orientation of a liquid crystal optical element that was oriented in the same manner using only liquid crystal A was approximately 30.
The orientation was clearly better than that of .

Note that the value of the degree of orientation was determined according to the well-known measurement method shown below.

That is, the liquid crystal optical element subjected to the above alignment treatment is arranged in parallel between two polarizing plates whose polarization axes are orthogonal to each other,
While white light from a halogen lamp was incident on this, the intensity change of the transmitted light was measured when the liquid crystal optical element was rotated around the light spot while keeping the polarizing plate in the same position.
Maximum intensity (Imax) and minimum intensity (Imin) at that time
The ratio of Imax/lm1n was taken as the degree of orientation.

Example 2 Low molecular liquid crystal A having the following structure and polymer liquid crystal C having the following repeating unit were mixed in the same manner as in Example 1 to obtain a liquid crystal A polymer liquid crystal composition.

Liquid crystal C Mn=4 000 Liquid crystal A: Liquid crystal C=60: (wt%) The above polymer liquid crystal composition was applied to two sheets of IT in the same manner as in Example 1.
A liquid crystal optical element was produced by sandwiching the glass substrates with O electrodes. Next, the liquid crystal composition was heated to 140°C while being sandwiched between glass substrates with ITO electrodes, and then slowly cooled to 123°C.
The liquid crystal molecules were oriented in one direction by a shearing method in which shearing stress was applied to the liquid crystal composition several times at C.

Regarding the obtained liquid crystal optical element, the phase transition behavior of the liquid crystal composition was observed using a polarizing microscope, and the above phase transition temperature was determined.

Next, when the transmitted light intensity was measured in the antiferroelectric phase (SmCA'' phase) at 60°C in the same manner as in Example 1, it showed a good tristable state as in Example 1. Transmission in the tristable state The light intensity ratio is 1:12: when the dark state is 1.
It was 30.

Further, when the degree of orientation of the obtained liquid crystal optical element was measured in the same manner as in Example 1, it was about 50, indicating that the degree of orientation of this polymeric liquid crystal composition was good.

Comparative Example 1 A polymer liquid crystal having the following repeating unit and a low molecular liquid crystal E having the following structure were mixed in the same manner as in Example 1 to obtain a polymer liquid crystal composition.

Liquid crystal DM n = 6 8 Liquid crystal E Liquid crystal D = Liquid crystal E = 20: 80 (weight%) glass +-5mC" ←--5mA ←--I
s.

The above polymer liquid crystal composition was applied to two IT sheets in the same manner as in Example 1.
A liquid crystal optical element was produced by sandwiching the glass substrates with O electrodes. Next, the liquid crystal composition was heated to 90°C while being sandwiched between glass substrates with ITO electrodes, and then slowly cooled, and the liquid crystal molecules were heated to 80°C several times by the shearing method in which shear stress was applied to the liquid crystal composition. oriented in the direction.

Regarding the obtained liquid crystal optical element, the phase transition behavior of the liquid crystal composition was observed using a polarizing microscope, and the above phase transition temperature was determined. This liquid crystal composition did not exhibit an antiferroelectric phase.

Next, when the transmitted light intensity was measured in the ferroelectric phase (SmC" phase) at 43°C in the same manner as in Example 1, only bistability was observed (Fig. 16). The ratio was 1:15, with the dark state being 1.

Example 3 Polymer liquid crystal F having the following repeating unit and low molecular liquid crystals A, G, and H having the following structures were mixed in the same manner as in Example 1 to obtain a polymer liquid crystal composition.

Liquid crystal F L Mn=4200 Liquid crystal A Liquid crystal G H3 Liquid crystal H (described in JP-A-1168793) Liquid crystal F: Liquid crystal A: Liquid crystal G: '1g, Crystal H = 30:30:
20:20 (wt%) glass +-SmC, 1
”←−−− Sn＋C” ←−−− SmA
Is.

The above polymer liquid crystal composition was applied to two IT sheets in the same manner as in Example 1.
A liquid crystal optical element was produced by sandwiching the glass substrates with O electrodes. Next, the liquid crystal composition was heated to 130°C while being sandwiched between glass substrates with ITO electrodes, and then slowly cooled to 120°C.
The liquid crystal molecules were oriented in one direction by a shearing method in which shearing stress was applied to the liquid crystal composition several times at C. It was further slowly cooled to room temperature.

Regarding the obtained liquid crystal optical element, the phase transition behavior of the liquid crystal composition was observed using a polarizing microscope, and the above phase transition temperature was determined. This liquid crystal composition exhibited an antiferroelectric phase over a wide temperature range including room temperature.

Next, when the transmitted light intensity was measured in the antiferroelectric phase (SmCA" phase) at 40°C in the same manner as in Example 1, the first
As shown in FIG. 7, similar to Example 1, a good stable state was exhibited. The ratio of transmitted light intensity at applied voltages of +30V, 0V, and -30V was 1:10:23.

Moreover, between the electrodes of this liquid crystal optical element, as shown in FIG.
The response time of the liquid crystal composition was measured when voltages with three types of waveforms were applied: waveform 2.0, which changes from ■ to OV, and waveform 3, which changes to +30V. The measurement temperature was 45°C. The results are shown in Table 1.

Comparative Example 2 A liquid crystal optical element in which liquid crystal molecules were oriented was produced using Liquid Crystal F in the same manner as in Example 3 (liquid crystal thickness: 2 μm).

Regarding this liquid crystal optical element, the 18th
The response time of the liquid crystal composition when voltages having the three types of waveforms shown in the figure were applied was measured. The measurement temperature was 45°C. The results are shown in Table 1.

Table 1 Example 4 Polymer liquid crystal I having the following repeating units and low molecular liquid crystals H and J having the following structures were mixed in the same manner as in Example 1 to obtain a polymer liquid crystal composition.

Liquid crystal I Mn=38 Liquid crystal H Liquid crystal J Liquid crystal J: Liquid crystal I: Liquid crystal = 6010:20 (wt%) The above polymer liquid crystal composition was applied to two sheets of IT in the same manner as in Example 1.
A liquid crystal optical element was produced by sandwiching the glass substrates with O electrodes. Next, the liquid crystal composition was heated to 110°C while being sandwiched between glass substrates with ITO electrodes, and then slowly cooled to 100°C.
The liquid crystal molecules were oriented in one direction using the shearing method in which shearing stress was applied to the liquid crystal composition several times.

Regarding the obtained liquid crystal optical element, the phase transition behavior of the liquid crystal composition was observed using a polarized light microscope vl! The above phase transition temperature was determined by observation using a mirror. As mentioned above, this polymeric liquid crystal composition exhibited an antiferroelectric phase over a wide temperature range including room temperature.

Next, when the transmitted light intensity was measured in the antiferroelectric phase (SmCA" phase) at 40° C. in the same manner as in Example 1, it showed a good stable state as in Example 1. The applied voltage was ±3
The ratio of transmitted light intensities at 0V, OV, and -30V was 1:16.

Further, similarly to Example 3, the response time of the liquid crystal composition was measured when voltages having the three types of waveforms shown in FIG. 18 were applied between the electrodes of this liquid crystal optical element. Measurement temperature is 35°
It was set as C. The results are shown in Table 2.

Comparative Example 3 A liquid crystal optical element in which liquid crystal molecules were oriented was produced in the same manner as in Example 4 using liquid crystal (1) (liquid crystal thickness: 2 μm).

Regarding this liquid crystal optical element, the 18th
The response time of the liquid crystal composition when voltages having the three types of waveforms shown in the figure were applied was measured. The measurement temperature was 35°C. The results are shown in Table 2.

Table 2 Note that polymer liquid crystal F used in Example 3 and polymer liquid crystal II used in Example 4 were synthesized as follows.

(Ill armpit 1i needle and nail storage) LCD F C.B.

■ CH3 4-acetoxybenzoic acid 0.1 mol and thionyl chloride 5
The solution of 0d was stirred at 80°C for 2 hours. After the reaction, excess thionyl chloride was distilled off under reduced pressure to obtain an acid chloride. next,
Ethyl-3-hydroxybutano-[-10.12 moles and 0.2 moles of triethylamine in THF500j! i!
The solution was stirred. In this, the acid chloride obtained earlier was added to TH
It was added dropwise as a F solution and stirred for 8 hours. The reaction solution was concentrated, extracted with ether, dried, concentrated, and purified by column chromatography to obtain the desired ester (1) (yield: 86%).

A solution of 80 mmol of the ester (1) obtained in step (2) in 200 d of ether was stirred. Add 40 benzylamine to it.
rR1 was introduced and stirred for 1 hour. The reaction solution was extracted with ether, dried, concentrated, and purified by column chromatography to obtain the desired alcohol (2) (yield 96%).
).

Synthesis of (3) The intermediate [4'-(12-bromododecyloxy)biphenyl-
4-carboxylic acid] 50 mmol and thionyl chloride 30 d
The solution was stirred at 80°C for 2 hours. After the reaction, excess thionyl chloride was distilled off under reduced pressure to obtain an acid chloride. Next, a 200 m THF solution of 60 mmol of the alcohol compound (2) obtained in step (2) and 70 mmol of triethylamine was stirred.

The acid chloride obtained earlier was added dropwise as a THF solution to this, and the mixture was stirred for 8 hours. The reaction solution was concentrated, extracted with ether, dried, concentrated, and purified by column chromatography to obtain the desired ester (3) (yield: 76%).

(2) Synthesis of CH,+ (4) 18 mmol of 22-dihydroxymethylpropionic acid and 20 mmol of tetramethylammonium hydroxide (pentahydrate) were stirred in DMF 150 for 2 hours. Next, 8 mmol of the ester (3N) obtained in step ① was added to this, and the mixture was stirred for 6 hours.

After the reaction, the reaction mixture was extracted with ether, dried, concentrated, and purified by column chromatography to obtain the desired ester (4) (yield: 62%).

Polycondensation reaction ■ CH.

Synthesis 1.7 mmol of the ester (4) obtained in step (4) and 5rI11 of pyridine were placed in 30 d of toluene and stirred while maintaining the solution at 70''C. It was added dropwise and stirred for 12 hours.Then, the reaction solution was poured into a large amount of acetone cooled to -70°C to stop the polycondensation reaction.After returning the temperature to room temperature, it was concentrated and purified by column chromatography. conduct,
The structure was confirmed by NMR and IR measurements, and the desired polymer was obtained (yield 77%, Mn = 4,200 (GP
(, Ps conversion)). Figure 19 shows the NMR measurement results, Figure 20
The figure shows the IR measurement results.

(11) Kairansu-m 戊 LCD I CI(.

■ CH.

4-acetoxybenzoic acid 0.1 mol and thionyl chloride 5
0j! I! The solution was stirred at 80°C for 2 hours. After the reaction, excess thionyl chloride was distilled off under reduced pressure to obtain an acid chloride.

Next, [-butyl-3-hydroxybutanoate 0.1
2 moles and 0.2 moles of triethylamine in THF500d
The solution was stirred. In this, the acid chloride obtained earlier was added to TH
It was added dropwise as a Fi solution and stirred for 8 hours. The reaction solution was concentrated, extracted with ether, dried, concentrated, and purified by column chromatography to obtain the desired ester (5) (yield: 81%).

A solution of 80 mmol of the ester (5) obtained in step (2) in 200 m of ether was stirred. Add 40 hensylamine to it.
d and stirred for 1 hour. The reaction solution was extracted with ether,
After drying and concentrating, it was purified by column chromatography.
The desired alcohol (6) was obtained (yield 96%).

Synthesis of (7) The intermediate [4'-(12-furomotodecyloxy)biphenyl-
50 mmol of 4-carboxylic acid and 30 mmol of thionyl chloride
The solution was stirred at 80°C for 2 hours. After the reaction, excess thionyl chloride was distilled off under reduced pressure to obtain an acid chloride. Next, a THF200a+f solution of 60 mmol of the alcohol compound (6) obtained in step (2) and 70 mmol of triethylamine was stirred. The acid chloride obtained earlier was added dropwise as a THF solution to this, and the mixture was stirred for 8 hours. After concentrating the reaction solution, it was extracted with ether, dried, concentrated, and purified by column chromatography to obtain the desired ester (7) (yield 79%).
).

■ Synthesis of CH3 (8) 2.18 mmol of 2-dihydroxymethylpropionic acid and 20 mmol of tetramethylammonium hydroxide (pentahydrate)
The mmol was stirred in 150 ml of DMF for 2 hours. Next, 18 mmol of the ester compound (7) obtained in (1) was added to the mixture, and the mixture was stirred for 6 hours.

After the reaction, the reaction mixture was extracted with ether, dried, concentrated, and purified by column chromatography to obtain the desired ester (8) (yield: 71%).

Polycondensation reaction - ■ Synthesis of CH3 1.7 mmol of the ester (8) obtained in step (1) and 5 m of pyridine are placed in 30 mm of toluene, and ? 70% liquid
The mixture was stirred while being maintained at °C, and 1.7 mmol of heglutaric acid dichloride was added dropwise thereto, followed by stirring for 12 hours. Next, the reaction solution was poured into a large amount of acetone cooled to -70°C to stop the polycondensation reaction. After returning the temperature to room temperature, column chromatography purification was performed after concentration, and NM
The structure was confirmed by RlIR, and the desired polymer was obtained (yield 87%, Mn=3,800 (GPC, Ps conversion)).

FIG. 21 shows the NMR measurement results, and FIG. 22 shows the IRi measurement results.

〔Effect of the invention〕

The polymer liquid crystal composition of the present invention has a plurality of distinct stable states and can obtain high-speed response without impairing antiferroelectricity or orientation.

Further, the liquid crystal optical element of the present invention uses this polymeric liquid crystal composition, does not require an alignment film, and can obtain uniform alignment over a large area.

Furthermore, the method for driving a liquid crystal optical element of the present invention does not involve unstable driving of the above-mentioned liquid crystal optical element by conventional bistable driving.
It is possible to perform stable driving by utilizing the third state.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of the liquid crystal optical element of the present invention. FIG. 2 is an explanatory diagram showing the movement of ferroelectric liquid crystal molecules within a liquid crystal optical element. FIG. 3 is an explanatory view of the liquid crystal molecules shown in FIG. 2 viewed from above, and FIG.
b) represents the state b in FIG. FIG. 4 is an explanatory diagram showing the state of liquid crystal molecules in a state where the electric field of a liquid crystal optical element using antiferroelectric liquid crystal is zero. 5 and 6 are graphs showing the states of liquid crystal molecules with respect to changes in applied voltage in a liquid crystal optical element using ferroelectric liquid crystal and a liquid crystal optical element using antiferroelectric liquid crystal, respectively. The horizontal axis shows the applied voltage (V), and the vertical axis shows the state of the liquid crystal molecules. FIG. 7 is an explanatory diagram showing the directions of the optical axis of the liquid crystal molecules in each state and the polarization axis of the polarizing plate. FIGS. 8(a) and 8(b) are graphs showing the transmitted light intensity T when a triangular wave voltage is applied between the electrodes of the liquid crystal optical element. The horizontal axis shows the voltage (■), and the vertical axis shows the transmitted light intensity T. FIG. 9 is a graph showing an example of the driving voltage applied between the electrodes of the liquid crystal optical element of the present invention. The horizontal axis is time (t),
The vertical axis represents voltage (V). FIG. 10 is a graph showing an example of a practical driving pulse voltage applied between the electrodes of the liquid crystal optical element of the present invention. The horizontal axis represents time (t), and the vertical axis represents voltage (■). FIG. 11(a) is a graph showing the transmitted light intensity T of a bistable liquid crystal optical element, and the horizontal axis is the voltage (
V), the u-axis indicates the transmitted light intensity T. FIG. 11(b) shows
11 is a graph representing a practical driving pulse voltage applied between the electrodes of the liquid crystal optical element shown in FIG. 11(a). The horizontal axis is time (
t), the If axis represents voltage (V). FIG. 12 is a graph showing the driving voltage used in the example. The horizontal axis represents time (t), and the N axis represents voltage (V). 13 and 14 are graphs showing the transmitted light intensity T when the voltage shown in FIG. 12 is applied between the electrodes of the liquid crystal optical element of Example 1, respectively. The horizontal axis shows time (L), and the vertical axis shows transmitted light intensity T. FIG. 15 is a graph showing the polarization reversal current of the liquid crystal optical element of Example 1. The horizontal axis represents time (1), and the vertical axis represents current (arbitrary scale a, u,). FIG. 16 shows the 12th electrode between the electrodes of the liquid crystal optical element of Comparative Example 1.
It is a graph showing the transmitted light intensity T when the voltage shown in the figure is applied. The horizontal axis is time (1), and the vertical axis is the transmitted light intensity T.
shows. FIG. 17 is a graph showing the voltage applied to the liquid crystal optical element of Example 3 and the transmitted light intensity T. The horizontal axis shows time (t), and the vertical axis shows voltage (V) and transmitted light intensity T. FIG. 18 is a graph showing the voltage applied to the liquid crystal optical element in Example 3 and the like. The horizontal axis is time (1), and the vertical axis is voltage (
V). FIG. 19 and FIG. 21 are charts showing the NMR measurement results of the polymer liquid crystal used in Example 3.4, respectively. FIGS. 20 and 22 are charts showing the IR measurement results of the polymer liquid crystal used in Example 3.4, respectively. Explanation of symbols 1.7 Polarizing plate 2.6 Substrate 3.5 Electrode 4 Polymer liquid crystal composition 8 Liquid crystal molecule 9 Dipole 10 Cone representing the movement locus of liquid crystal molecule 8 11 Smectink layer 12 Optical axis 13.14 Polarization axis

Claims (1)

[Scope of Claims] Consisting of one or more types of low molecular liquid crystals and one or more types of polymer liquid crystals, at least one type of low molecular liquid crystal or polymer liquid crystal exhibits antiferroelectricity. A polymer liquid crystal composition characterized by: 2. A liquid crystal optical element comprising the polymer liquid crystal composition according to claim 1 sandwiched between two opposing electrodes. 3. A voltage in the form of a pulse wave with two positive and negative biases is applied between the electrodes of the liquid crystal optical element according to claim 2 in a temperature range in which the polymeric liquid crystal composition exhibits an antiferroelectric phase. A method for driving liquid crystal optical elements.