JP5453739B2 - Liquid crystal element - Google Patents

Description

  The present invention relates to a liquid crystal element capable of continuously changing the extinction position depending on the electric field strength and a method for manufacturing the liquid crystal element.

According to the ferroelectric liquid crystal material proposed by Clark and Ragawall, spontaneous polarization is developed by having a permanent dipole moment in the perpendicular direction of the molecule with respect to the long axis of the molecule. It is described that it can be optically switched, has bistability, and has a fast response to a change in electric field (see Patent Document 1). A liquid crystal display device (display) using this ferroelectric liquid crystal material is expected to be applied as a large-screen, high-definition liquid crystal display element by a simple matrix drive. However, the smectic C * phase of the ferroelectric liquid crystal used for switching needs to unwind the spiral when the orientation of the liquid crystal molecules shows a spiral state and is applied to a display.
In general, smectic liquid crystal, which is a ferroelectric liquid crystal, is known to have a layer structure, and in the smectic C * phase, it is a layer of adjacent liquid crystal directors in the layer. A spiral axis is drawn macroscopically in the normal direction of the layer, deviating from the direction of the liquid crystal director. The distance that the shift of the director between adjacent layers makes a round is defined as the helical pitch. When this spiral structure is present, a striped pattern derived from the spiral pitch appears perpendicular to the spiral axis under polarized Nicols of polarized light, and in the absence of an electric field, light cannot be blocked by light scattering or diffraction, resulting in a normal black mode display. It was difficult to apply.

When it is injected into a liquid crystal cell having a cell thickness smaller than the spiral pitch for the purpose of unraveling the spiral, the spiral is unwound and the liquid crystal molecules tilt to the left and right with respect to the normal direction of the layered structure (the tilt angle is called the tilt angle). Orientation is obtained. This is because when the cell is made thin, the spiral is broken and the liquid crystal molecules are subjected to a strong interaction from the cell substrate interface and show a biaxial alignment state. This is called surface stabilized orientation state (SSFLCD) and is applied to optical elements and displays with bistability (memory property). However, since the helical pitch changes with temperature and the helical pitch tends to decrease with decreasing temperature, in order to obtain biaxial orientation in a wide temperature range (temperature range showing a smectic C * phase), at least cell thickness ≦ It is necessary to satisfy the relationship of the helical pitch within the range of the operating temperature condition, and a thin liquid crystal cell of 2 μm or less is used. When the thickness is 2 μm or less, the ferroelectric liquid crystal exhibits a memory property (bistability) of alignment due to the alignment stabilization (surface stabilization) of the surface of the liquid crystal cell substrate. A value display can be obtained, but in application to a full color display, continuous gradation display proportional to the applied voltage is essential, and in the bistable binary display, the gradation proportional to the applied voltage is required. This makes it impossible to display the full color display.
Furthermore, a display using ferroelectric liquid crystal which is currently in practical use eliminates alignment defects by using an obliquely deposited SiO ₂ film as the alignment film, increases the contrast, has a cell thickness of 2 μm or less, and An ultra-compact LCD of 2 inches or less. However, when the size of the LCD is increased, it becomes difficult to uniformly deposit the obliquely deposited SiO ₂ film. When the cell thickness is 2 μm or less, the yield deteriorates and the enlargement is limited.

In order to solve the problem of gradation display, a monomer having a mesogenic group is used together with the FLC material, and the polymer is polymerized by irradiating with ultraviolet rays to thereby stabilize the polymer, thereby eliminating the bistability and intermediate. Technologies that enable gradation display have been proposed (see Non-Patent Documents 1 and 2).
In addition, these include ultraviolet light at a temperature at which a liquid crystal composition containing a ferroelectric liquid crystal and a monofunctional liquid crystal acrylate monomer exhibits a predetermined liquid crystal phase such as a smectic A phase or a smectic C * phase. Has been disclosed, and a polymer-stabilized ferroelectric liquid crystal display device obtained by polymerizing a monofunctional liquid crystalline acrylate monomer is disclosed (see Patent Documents 2, 3, 4, and 5). Further, when the ferroelectric liquid crystal composition containing the ferroelectric liquid crystal material and the monofunctional liquid crystal acrylate monomer is irradiated with ultraviolet rays at a temperature showing the ferroelectricity, the composition is used in the liquid crystal cell. A method of irradiating ultraviolet rays while applying a DC voltage at a temperature at which an object exhibits ferroelectricity is disclosed (see Patent Document 4).

  The polymer-stabilized ferroelectric liquid crystal liquid crystal device manufactured by the above-described method can be applied with a direct current with respect to the easy axis of the alignment film when a direct current voltage of a different polarity is applied to the direct current voltage applied at the time of ultraviolet irradiation. In proportion to the absolute value of the voltage, the orientation direction of the ferroelectric liquid crystal material is tilted in a direction opposite to the tilt angle direction in which the polymer is stabilized. Even in this case, the bistability has disappeared. Therefore, if the applied voltage is removed, the ferroelectric liquid crystal material is arranged again at a position having a tilt angle where the polymer is stabilized with respect to the easy axis of the alignment film. In this way, halftone display is possible by utilizing the change in the orientation direction when a voltage of a different polarity is applied to the applied DC voltage during UV irradiation. However, since the tilt angle with respect to the polarity of the applied voltage is not symmetric with respect to the easy axis of the alignment film, the optical element is driven with a DC voltage, resulting in a decrease in reliability of the element such as baking.

  To solve this problem, a ferroelectric liquid crystal composition containing a monofunctional liquid crystalline acrylate monomer is sandwiched between a pair of substrates, and a voltage is applied to the ferroelectric liquid crystal layer while exhibiting a chiral smectic C phase. Regardless of the polarity of the applied voltage with respect to the easy axis of the alignment film, a means for polymerizing the liquid crystalline acrylate monomer by applying an AC electric field of 2 kHz to 4 kHz and irradiating ultraviolet rays or an electron beam is used. A polymer-stabilized ferroelectric liquid crystal liquid crystal element having a target tilt angle, uniaxial alignment, and V-shaped transmittance-voltage characteristics is disclosed (see Patent Document 6). The liquid crystal element is useful in that the element can be driven with an alternating voltage, but since liquid crystal monofunctional acrylate is used, the alignment is easily disturbed by deformation due to heat or external force, etc., and the reliability is low. Met.

  The technique proposed for realizing any of the above gradation displays is to stabilize the alignment of liquid crystal molecules so that uniaxial alignment can be obtained by stabilizing the polymer in the smectic C * phase exhibiting ferroelectricity. In this case, the halftone display is enabled by continuously changing the tilt angle of the liquid crystal molecules depending on the applied voltage. In order to obtain an intermediate gradation, the problem is solved by eliminating the bistability (memory property) of the surface-stabilized ferroelectric liquid crystal. However, when producing a polymer-stabilized ferroelectric liquid crystal, at least Using a thin liquid crystal cell with a thickness of 2 μm or less between a pair of substrates (cell thickness), the polymer precursor contained therein is polymerized while applying a voltage to a bi-stable biaxial orientation state. Since it is necessary to stabilize the polymer in the uniaxial orientation, it has been difficult to mass-produce optical elements having a cell thickness of 3 μm or more. Furthermore, since the cell thickness is about 1.5 μm and the spiral is unwound by interaction with the substrate interface, the voltage-transmittance characteristics are greatly affected by the substrate interface and the liquid crystal molecules are difficult to move with respect to the electric field. As a result, the tilt angle is lowered, causing problems such as a decrease in transmittance and an increase in driving voltage.

  In the range where the cell thickness is increased and the cell thickness is increased from 2 μm to 2 to 3 μm, no striped pattern showing a spiral structure is observed, but the liquid crystal director is twisted depending on the surface energy of the substrate and the elastic energy of the liquid crystal. Such a force is generated, and in the cell thickness direction, the ferroelectric liquid crystal molecule directors are aligned in a state of being slightly displaced from the rubbing alignment direction and twisted. Twisted orientation is added to the biaxial orientation state, and birefringent color is added to the dark field as seen in uniaxial orientation or biaxial orientation even if the polarization axis is rotated under polarized crossed Nicols, and this light leakage One of the reasons that perfect black cannot be obtained on a display is causing a decrease in contrast. (See Non-Patent Documents 3 and 4) Further, when the cell thickness is increased, a helical structure is developed. (Refer to Non-Patent Document 5) If this cell thickness is the critical cell thickness, if there is no critical cell thickness and there is no electric field, light scattering due to the interference color corresponding to the helical pitch and the helical structure occurs and a normal black display cannot be obtained. .

  From the above, there is no known ferroelectric liquid crystal display device having a cell thickness advantageous for manufacturing efficiency, and TFT driving is possible without using surface stabilization, high contrast, high speed response, high transmittance, and The development of a ferroelectric liquid crystal display element capable of continuously controlling the transmittance in proportion to the electric field intensity has been desired.

JP-A-56-107216 JP-A-9-212462 JP-A-9-21463 Japanese Patent Laid-Open No. 11-21554 JP 11-326909 A JP 2002-31821 A F. Furue, Japan Journal of Applied Physics (Jpn. J. Appl. Phys.), 36, L1517 (1997) F. Furue, Japan Journal of Applied Physics, Jpn. J. Appl. Phys., 37, 3417 (1998) Ouchi (Y.Ouchi), Japan Journal of Applied Physics (Jpn. J. Appl. Phys.), 26, 1 (1987) Shingu (T. Shingu), Japan Journal of Applied Physics (Jpn. J. Appl. Phys.), 25, L206 (1986) J. Pavel, Journal of Physics (J. Phys.), 45, 137 (1984).

  The problem to be solved by the present invention is to provide a liquid crystal device having a cell structure capable of mass production with improved helical structure, twisted alignment, and reduced transmittance, and not using a surface-stabilized alignment state, and a method for manufacturing the liquid crystal device There is to do.

In order to solve the above problems, the inventors of the present invention have studied the configuration of the liquid crystal device, and as a result, found a polymer-stabilized liquid crystal device having a configuration in which the pitch of the spiral structure and the cell thickness are optimized to a specific relationship. The present invention has been completed. In order to solve the above problems, the present invention has a liquid crystal layer composed of a transparent solid material composed of a liquid crystal composition containing an optically active compound and a polymer precursor between a substrate having a pair of electrode layers. In the liquid crystal layer, the liquid crystal composition is optically uniaxially aligned, and the helical pitch (the pitch (μm) of the helical structure that appears when no voltage is applied to the liquid crystal composition) and the cell thickness (of the liquid crystal layer). A liquid crystal element characterized in that the thickness (μm) satisfies the following relationship is provided.
In addition, the present invention forms a liquid crystal layer by sandwiching a liquid crystal composition containing an optically active compound and a polymer precursor that forms a transparent solid substance between a substrate having a pair of electrode layers. The helical pitch of the liquid crystal composition (the pitch (μm) of the helical structure that appears when no voltage is applied to the liquid crystal composition) and the cell thickness (the thickness of the liquid crystal layer (μm)) satisfy the following relationship:
Spiral pitch ≦ cell thickness The helical structure expressed by the liquid crystal composition is released in the absence of an electric field by stabilizing the polymer by unwinding the spiral with an external electric field or temperature and curing (crosslinking) the polymer precursor. The present invention provides a method for manufacturing a liquid crystal element that exhibits a uniaxial alignment state and whose extinction position changes continuously depending on the electric field strength by applying an electric field thereto.

  The liquid crystal device according to the present invention realizes a liquid crystal display having a high-speed response of several hundreds of microseconds in which a uniaxial alignment is obtained with a cell thickness of 3 μm or more, and halftone display based on V-shaped voltage-transmittance characteristics is possible. it can. The device and the manufacturing method of the present invention are excellent in mass productivity because the cell thickness is thicker than that of a conventional ferroelectric liquid crystal display device. Furthermore, since the liquid crystal element of the present invention applies a polymer stabilization technique, the liquid crystal element has a feature that is superior in impact resistance as compared with a conventional ferroelectric liquid crystal display element.

<Method of stabilizing the polymer in the orientation state where the helix is unwound>
In order to solve the above problems, the liquid crystal composition used in the present invention is a liquid crystal exhibiting a smectic C * phase by adding a chiral compound to a liquid crystal composition exhibiting a smectic C phase and exhibiting spontaneous polarization due to ferroelectricity. A polymerizable ferroelectric liquid crystal composition obtained by adding a small amount of at least one polymer liquid crystal compound to the composition. The polymerizable compound is transparent because the radically polymerizable compound contained in the liquid crystal is polymerized by active energy rays such as heat or ultraviolet rays, and the liquid crystal composition is phase separated or dispersed in the liquid crystal composition. It is used to obtain a polymer-stabilized liquid crystal display device comprising a conductive polymer material and a liquid crystal composition.

  This element is a liquid crystal element having an alignment control film and a liquid crystal layer between a substrate having a pair of electrode layers, wherein the liquid crystal layer contains at least one liquid crystalline polymer precursor, and a non-liquid crystalline polymer precursor Orientation of the mesogenic group of the liquid crystalline polymer precursor in a state in which no voltage is applied between the pair of electrode layers, and the photocured composition of the photocurable composition and the ferroelectric liquid crystal material can also contain And a liquid crystal display element in which the orientation of the ferroelectric liquid crystal material is aligned with the alignment direction of the orientation control film and the polymer is stabilized in a state where the spiral is unwound by an electric field so that the orientation is fixed. A liquid crystal composition containing a curable substance that can also contain a liquid crystalline polymer precursor and a non-liquid crystalline polymer precursor in the liquid crystal layer, and the cured product is in a fine particle form by polymerization phase separation. Or dispersed in a fine mesh, A polymer chain having a liquid crystalline skeleton in a part of the compound, and the ferroelectric liquid crystal molecules are stabilized in alignment so that uniaxial alignment is obtained by the interaction between the polymer chains and the ferroelectric liquid crystal molecules, In the state where no voltage is applied, the extinction position is obtained by exhibiting uniaxial orientation and matching the polarization axis. When a voltage is applied, the dipoles of the ferroelectric liquid crystal reorientate in the direction of the electric field, the orientation direction of the liquid crystal molecules tilts from the uniaxial orientation, and the transmittance is changed by the continuous change of the tilt angle to change the continuous level. V-shaped voltage-transmittance characteristics that can be displayed in gray scale. This characteristic enables application to a display capable of full color display.

In order to obtain an extinction position by uniaxial orientation with a cell thickness of 3 μm or more, it is necessary to solve the problem of twisting and twisting orientation. In the present invention, the polymer is stabilized by polymerizing a polymer precursor (liquid crystalline acrylate) contained in the composition by applying ultraviolet rays or the like to the alignment state of the liquid crystal in which the spiral is broken, and the spiral is broken. A means for maintaining the alignment state even in the absence of an electric field is applied. The means to solve the spiral is
1. 1. A method of aligning dipoles (dipoles) of liquid crystal molecules in the electric field direction by applying a DC electric field. 2. Method of increasing the liquid crystal composition and temperature to make the helical pitch larger than the cell thickness A method of polymerizing a polymer precursor while applying an alternating voltage that can unwind a spiral so as to obtain uniaxial orientation can be mentioned.

The means for applying one electric field applies an electric field strength that overcomes the force of winding the spiral. Depending on the chiral compound used, a strong electric field strength of at least 5 V / μm or more is required. Also, depending on the polarity of the direct current and the direction of the dipole of the chiral compound, the liquid crystal molecules are aligned in a direction inclined to the left or right from the normal direction of the liquid crystal layer, and when the polymer is stabilized, an asymmetric V-shaped voltage − A transmissivity characteristic or a half V-shaped voltage-transmittance characteristic is exhibited, and AC driving becomes difficult. 2 is that the spiral can be solved by adjusting the ratio of the chiral compound showing the right hand of the helix and the chiral compound showing the left hand of the helix to a helical pitch greater than the cell thickness, the addition amount, and the kind of the chiral compound. Although it is possible, in particular, as a method of unwinding the spiral at a cell thickness of 3 μm or more, it is necessary to use a chiral compound with weak spiraling force or to reduce the concentration of the chiral compound in the composition to a few percent, for example There is. In this case, the spontaneous polarization of the ferroelectric liquid crystal composition is lowered, resulting in a slow response speed and an increase in driving voltage. In order to increase the spontaneous polarization, the concentration of the chiral compound is increased. However, the helical pitch is reduced, the concentration range in which the helix can be dissolved is narrowed, and the probability that the helical structure is manifested by a vortex concentration change is high, which is not preferable as an industrial product. In addition, the helical pitch changes depending on the temperature, and the size of the helical pitch and the temperature dependence of the helical pitch vary depending on the type of host liquid crystal and chiral compound used. There was a problem that was not always solved. Furthermore, since the types of chiral compounds exhibiting a large pitch are limited, it has been difficult to obtain a practical composition. There is a method to increase the spiral pitch by heating to a temperature near the smectic A phase-smectic C * phase transfer using the increase in the spiral pitch when the temperature is raised, but the spiral pitch exceeds the cell thickness. Although the helix is unraveled, a twisted alignment state appears and becomes a factor of reducing the contrast of the display. When the alignment state is observed with a polarizing microscope, it can be seen that a birefringence color due to the twisted alignment state is added to the dark portion.

  The method of applying an AC electric field of 3 is that a uniaxial alignment is obtained by an electric field applied when polymer precursors are polymerized to stabilize the alignment state of liquid crystal molecules, and in the initial alignment, smectic is used. When the C * phase orientation structure is a chevron structure, it is changed to a pseudo-bookshelf structure by switching to a switching state, which stabilizes the polymer and greatly reduces the zigzag orientation defects peculiar to ferroelectric liquid crystals. An orientation state in which a uniaxial orientation can be obtained from a state in which the monodomain state is stabilized by a polymer and the helical structure and twist orientation appearing at a cell thickness of 3 μm or more (critical cell thickness or more) are eliminated. This is the point of stabilizing the polymer. That is, when a spiral structure appears with a relationship of spiral pitch ≦ cell thickness, the means for applying an electric field according to the present invention has a V-shaped electro-optic effect after the elements are polymerized with the electric field strength necessary for unraveling the spiral. It is important to apply an AC electric field having a frequency that exhibits a mold voltage-transmittance characteristic and at which a uniaxial orientation is obtained. In order to solve the spiral with an AC electric field, the electric field generates a force that causes the dipoles to align in the direction of the electric field, so that the spiral gradually dissolves and the spiral pitch becomes infinite. It takes about 10 milliseconds from the time the electric field is applied until the helix is unwound by the influence of the elastic modulus, dipole moment and viscosity of the smectic C * phase. Therefore, if the frequency is faster than the time for the spiral to unwind, the polarity of the electric field is switched before the dipoles are completely aligned, so the dipoles are not aligned with the alternating electric field and the spiral cannot be unwound. It is preferable to apply an alternating electric field having a frequency of at least about 200 Hz or less.

In addition, when twisted orientation appears due to the relationship of spiral pitch ≦ cell thickness, the director moves at high speed or vibrates by applying a frequency (several kHz) equal to or higher than the polarization reversal speed of the liquid crystal. It is more preferable because the polymer can be stabilized in such a state that the twisted alignment state disappears and good uniaxial alignment is shown by widening the orientation distribution range of the director, and the initial liquid crystal alignment state before the polymer stabilization is obtained. Accordingly, the frequency and voltage of the AC electric field can be adjusted and applied.

On the other hand, it is considered that the uniaxial orientation can be obtained by applying alternating current. Before UV exposure (before polymer precursor polymerization), a smectic C * phase is exhibited and the liquid crystal molecules are tilted with respect to the normal direction of the layer structure. In this state, when an alternating voltage is applied to move the liquid crystal molecules, a conical locus drawn by rotating around the normal line as a center line is drawn. Such a liquid crystal alignment state passes through the alignment state of either the right rotation or the left rotation of the first cone depending on the polarity of the applied voltage and the direction of the dipole moment of the chiral compound. In this rotating state, when the polymer precursor is polymerized while applying an alternating electric field, the liquid crystal alignment state shows a quenching position at the center position (near the normal direction) of the V shape drawn in the conical section. It is stabilized and a uniaxial alignment state is developed. This occurs with the probability that the liquid crystal molecules are fixed by polymerization depending on the rotation speed due to the conical rotation of the liquid crystal molecules, and the distribution of directors scattered in the conical shape eliminates the optical biaxiality. Present to show optical uniaxiality. When the directors are clogged and distributed in a V-shape drawn in a conical section, when the directors are uniformly distributed in a conical shape, the orientation state can be cited as uniaxial. As a result, a normal black liquid crystal display can be manufactured. In a liquid crystal display, a V-shaped voltage-transmittance characteristic capable of AC drive continuous tone display is obtained, and when used in a display, reliability is improved.

However, depending on the type of polymer precursor used, the direction of uniaxial orientation may be significantly off from the vicinity of the normal direction, resulting in an asymmetric V-shaped voltage-transmittance characteristic, or uniaxial orientation may be disturbed. It is necessary to adjust the composition of the polymer precursor so as to obtain a V-shaped voltage-transmittance characteristic. The uniaxial orientation is affected by the voltage and frequency applied when polymerizing the polymer precursor. When the applied voltage is low and the polymer is stabilized, uniaxial orientation is not observed, and two domains derived from the two orientation states on the cone are present at the same time, and the polymer is stabilized and uniform uniaxial orientation cannot be obtained. This is not preferable because the black level of the display increases and the contrast decreases. As the voltage indicating this state is raised, the two distinct domains become aligned in one direction. When the polymer is stabilized by UV exposure above this voltage, uniform uniaxial orientation is obtained. In such a state, the polymer is stabilized, and when an element is placed between two orthogonal polarizing plates, the extinction position is observed at the position of the polarizing axis of the polarizing plate. Such an alignment state is preferable because normal black is obtained in a display. If a voltage several times the saturation voltage is applied, the ferroelectric liquid crystal layer moves due to a strong electric field, and the alignment is disturbed. Furthermore, the orientation of uniaxial orientation also depends on the frequency. When the frequency is low, the orientation tends to decrease. This is due to the increase in the amount of light leaked due to an increase in liquid crystal deviating from the alignment processing direction such as light leakage and rubbing due to zigzag alignment defects derived from the chevron structure in the smectic C * phase layer structure. ing.

Furthermore, when polymerization is performed by applying a low-frequency rectangular wave, two domains having an alignment state inclined to the right and left exist during the polymerization process, and the biaxial alignment state is stabilized, which is not preferable. As the frequency is increased from about several hundred Hz to a frequency (about several kHz) about the electro-optic switching speed, the chevron structure is changed to a pseudo chevron structure and the zigzag defect that causes light leakage disappears. The liquid crystal aligned in the alignment processing direction increases, the alignment improves, the black level decreases, and the contrast is improved in the display, which is more preferable. However, as the frequency increases, the dipole does not follow the alternating electric field velocity and spirals. The structure appears and the desired uniaxial orientation cannot be obtained. Therefore, it is necessary to produce an electro-optic element by searching for conditions (frequency, voltage) in consideration of physical properties (viscosity, elasticity, dipole moment, spontaneous polarization) of the composition to be used. Furthermore, the uniaxial orientation is also affected by the orientation process before polymerizing the polymer precursor, the phase sequence of the ferroelectric liquid crystal composition used, and the helical pitch of the N * phase. At least the phase sequence of the ferroelectric liquid crystal required for the present application is preferably the phase sequence of the isotropic phase → N * phase → smectic A phase → smectic C * phase from the high temperature side. After injecting into the N * phase, it is gradually cooled from the N * phase side in the vicinity of the N * phase to smectic A phase transition temperature (T _na ) to align the liquid crystal molecules in the alignment process direction and align the liquid crystal molecules. More preferred. At this time, it is a necessary condition for improving the uniaxial orientation that the helical pitch of the N * phase is solved before the transition to the smectic A phase.

When the spiral pitch of the N * phase is not solved, the disorder of orientation occurs in the smectic A phase, which causes a decrease in uniaxial orientation. The slow cooling is preferably performed at a rate of at least 2 ° C./min in the range of T _na to + 3 ° C. to T _na −1 ° C. That is, after the alignment process, when the spiral structure is exhibited under the condition of spiral pitch ≦ cell thickness, the liquid crystal display of the present application is manufactured using one means. The first means is to polymerize the polymer precursor while applying a frequency necessary for unwinding the helix and a frequency at which the electric field strength and the uniaxial orientation become high, preferably about 50 to 200 Hz. When the twisted orientation is exhibited under the condition of spiral pitch ≦ cell thickness, the liquid crystal display of the present application is manufactured using the three means. Furthermore, the waveform of the AC voltage can be any of a triangular wave, a sine wave, and a rectangular wave, but a rectangular wave is more preferable for increasing the contrast.

In the second means, chiral compounds having the same direction of spontaneous polarization with respect to the polarity of the electric field and different spiral directions are added to the host liquid crystal composition in such a ratio that a desired helical pitch can be obtained. However, since the helical pitch changes with temperature, it is difficult to maintain the helical pitch at 3 μm or more over the entire operating range of the device (eg, −30 ° C. to 80 ° C.). Therefore, it is preferable to polymerize the polymer precursor under a voltage condition that can obtain the above-described good uniaxial orientation at a temperature at which the spiral is unwound in the cell thickness of the liquid crystal cell to be used. In this case, since the probability of exhibiting a twisted orientation is high, it is preferable to produce by three means. As a result, the above-mentioned means capable of maintaining the unwound state in the entire operating temperature range, polymerization of the polymer precursors 1, 2, and 3 can be performed by a method using heat, electron beam, or ultraviolet ray. Of these, the method using ultraviolet rays is preferable because of its excellent productivity. However, it is preferable to use a high-pass sharp-cut filter of ultraviolet rays for exposure because short wavelength ultraviolet rays decompose liquid crystal molecules. In particular, when used in TFT driving applications, it is preferable to completely cut short wavelength ultraviolet rays of 365 nm or less in order to suppress a decrease in voltage holding ratio. It is preferable to select the type of the sharp cut filter according to the type of the ultraviolet light source so as to obtain an optimum result. As for the exposure amount of an ultraviolet-ray, 1500-3000mJ / cm < ² > is preferable.

  The cell thickness is preferably 3 μm or more, which allows mass production. Furthermore, the cell thickness is also strongly influenced by the V-shaped voltage-transmittance characteristics. If the cell thickness is thin, the effect of the spiral structure and twist orientation is eliminated, but on the other hand, the effect of the interaction with the substrate interface increases inversely with the cell thickness, and the tilt angle (tilt angle) decreases and the transmittance decreases. Cause the drive voltage to increase. In order to obtain high transmittance characteristics, it is preferable that the cell thickness is at least 2 μm, and 3 μm is more preferable in consideration of mass productivity. Further, Δn of the liquid crystal can be adjusted so that the transmittance (the product of Δnd where the refractive index anisotropy Δn of the liquid crystal is Δn and the cell thickness d) is λ / 2 when the wavelength of light is λ. preferable.

<Electro-optical characteristics showing low voltage drive and high contrast>
In the polymer-stabilized liquid crystal display device formed in this way, the driving voltage and light scattering increase in proportion to the content of the polymer precursor added to the composition. When the content of the precursor is very small, the degree of increase in driving voltage is reduced, but the thermal and mechanical stability is poor. In order to increase the reliability, it is necessary to increase the content of the precursor, and at this time, an increase in driving voltage, a decrease in liquid crystal alignment, and the appearance of scattering properties become problems. For example, Japanese Patent Laid-Open No. 6-222320 discloses the relationship of the following equation as an increase in the driving voltage as a description relating to the driving voltage of the polymer dispersed liquid crystal display element. The concept for the driving voltage of the polymer-stabilized liquid crystal element is the same as that of the polymer-dispersed liquid crystal display element, and is as follows.

(Vth represents a threshold voltage, ¹ Kii and ² Kii represent elastic constants, i represents 1, 2 or 3, Δε represents dielectric anisotropy, and <r> represents a transparent polymer substance. (Indicates the average gap distance of the interface, A indicates the anchoring energy of the transparent polymer substance with respect to the liquid crystal composition, and d indicates the distance between the substrates having transparent electrodes.)

  According to this, the driving voltage of the nematic liquid crystal polymer-stabilized liquid crystal display element includes the average gap distance at the interface of the transparent polymer material, the distance between the substrates, the elastic constant / dielectric anisotropy of the liquid crystal composition, and the liquid crystal Determined by the anchoring energy between the composition and the transparent polymeric material. Among these, in general liquid crystal display elements, the driving voltage is determined by the cell thickness, the dielectric anisotropy, and the elastic constant. In the polymer-stabilized liquid crystal display element, the transparent polymer is the same as the polymer dispersed liquid crystal. The driving voltage is greatly influenced by the anchoring energy between materials, and this phenomenon becomes a characteristic phenomenon in the composite system of liquid crystal and polymer. However, in the case of a ferroelectric liquid crystal, spontaneous polarization Ps is used instead of the above-described Δε. Therefore, also in the polymer-stabilized liquid crystal display element, the area of the interface between the polymer and the liquid crystal is increased and the anchoring energy of the system is increased to increase the driving voltage. In other words, it means that when the content of the liquid crystalline polymer precursor is increased in the composition of the present invention, the driving voltage is increased. In order to reduce the increase in drive voltage and maintain a low drive voltage, the anchoring energy of the polymer constituting the polymer-stabilized liquid crystal may be lowered. For example, the effect of the polymerizable polymer precursor is to stabilize the uniaxial orientation of the low-molecular liquid crystal. On the other hand, the non-liquid crystalline polymer precursor serves to reduce an increase in driving voltage due to the polymerizable polymer by using the non-liquid crystalline polymer having a weak anchoring force with respect to the low molecular liquid crystal. By adjusting the composition by using a polymerizable liquid crystal polymer precursor and a non-liquid crystal polymer precursor used in the composition, the driving voltage, which is a problem, can be lowered while maintaining the reliability of polymer stabilization. it can.

In order to lower the energy of the non-liquid crystalline polymer precursor, a bifunctional monomer having an alkyl side chain may be used. In particular, the alkyl side chain preferably has 5 to 15 carbon atoms, and more preferably 8 to 13 carbon atoms. When the alkyl side chain is short, the anchoring energy is high, and when it is too long, the influence of the side chain is strong and the anchoring energy is high. Further, if a mesogenic group having a benzene ring or the like similar to a low-molecular liquid crystal is used as a side chain, the affinity with the low-molecular liquid crystal is increased and the anchoring energy is increased, which is not preferable. Furthermore, the distance between the alkyl side chains is also important, and is preferably 6 to 18 in terms of the number of carbon atoms. Although it depends on the liquid crystal composition to be used, if the distance between the alkyl side chains is narrow, the low-molecular liquid crystal is not preferred because it is vertically aligned at the polymer interface.

  The anchoring energy is determined by the balance between the intermolecular interaction that the side chain exerts on the low-molecular liquid crystal and the intermolecular interaction that the main chain exerts on the low-molecular liquid crystal. Be minimized. Furthermore, the distance between crosslinks of the polymer affects the thermal mobility of the polymer main chain. If the distance between crosslinks is short and the thermal mobility is low, the molecular interaction with the low-molecular liquid crystal is strong and the anchoring energy is increased. As the distance between crosslinks becomes longer, the thermal mobility of the polymer main chain increases and the fluctuation due to the heat of the main chain increases, and if the fluctuation force becomes larger than the intermolecular interaction force, it acts to cancel the intermolecular interaction Anchoring energy is reduced. However, if the distance between crosslinks is long, the polymerization rate of the polymer precursor is slowed, and the compatibility with the liquid crystal is lowered. As an index representing the thermal mobility of the polymer main chain, a polymer glass transition temperature is generally used.

The polymer used in the present invention is preferably a polymer precursor having a glass transition temperature of room temperature or lower for the purpose of lowering anchoring, and further has a glass transition temperature of 0 to -100 ° C. Is more preferable. In addition, in order to lower the glass transition temperature, it is preferable to lower the glass transition temperature in order to improve mechanical stability. If the glass transition temperature is higher than room temperature, the polymer network structure that stabilizes the liquid crystal alignment with the polymer may be deformed or damaged due to deformation from the outside of the device, etc. . When the glass transition temperature is low, even if the network structure is deformed, the original orientation is restored by the elasticity of the network and the fixed orientation is maintained. That is, by adjusting the main chain length and side chain length of the liquid crystal composition and polymer precursor used in the present invention, and using a polymer precursor having a glass transition temperature of room temperature or lower, the driving voltage is low, A highly reliable polymer-stabilized liquid crystal element can be obtained. However, the composition stability of the alignment due to mechanical deformation or thermal change and the good electro-optical characteristics showing low voltage driving characteristics are in a trade-off relationship, so that the composition of the polymer precursor used in the present invention, if necessary, and It is preferable to adjust the liquid crystal composition to obtain desired characteristics.

The polymer-stabilized liquid crystal is a polymer precursor dispersed in the liquid crystal, which fixes or stabilizes the desired orientation of the liquid crystal. For this reason, it is necessary to avoid light scattering by the polymer formed by phase separation. Therefore, it is preferable to form a fine network polymer or fine particles that do not cause light scattering by a polymerization process or a composition adjustment of a polymer precursor, and have a size not larger than the wavelength of visible light and at least 400 nm or less.

  Furthermore, the phase separation method may disturb the orientation of the low-molecular liquid crystal. In this case, a polymerizable liquid crystal polymer precursor having a high degree of orientation order may be used so as to obtain the desired stabilizing orientation. In addition, the external field can be prepared by adjusting the external field so that the target polymer-stabilized liquid crystal element can be obtained by utilizing the electric field, the alignment regulating force of the alignment film, the magnetic field external field, and the like. Furthermore, it is a copolymer of a polymerizable liquid crystal polymer precursor and a non-liquid crystal polymer precursor, and is applied with a regularity by applying the self-organization properties of mesogenic groups and self-organization based on hydrogen bonding groups. A certain periodic structure may be formed. If necessary to obtain desired characteristics, a structure in which nanoparticulate polymer is dispersed in a low molecular liquid crystal may be used. In addition, by using a polymer-stabilized liquid crystal composition composed of a liquid crystal polymer precursor and a non-liquid crystal polymer precursor having a low anchoring force, the driving voltage is low, halftone display is possible, and the polymer is stable. It is possible to obtain a high-contrast liquid crystal display element that is highly reliable and has no light scattering. However, when an alignment defect occurs, the display contrast decreases.

<Liquid crystal element>
In order to fix the state in which the liquid crystal is aligned with an alignment film or the like by stabilizing the polymer in a state where there are few alignment defects, in the case of a ferroelectric liquid crystal, the speed is at least about 2 ° C. per minute from the nematic phase. It is preferable that the substrate is cooled to cause a phase transition to a chiral smectic C phase, and the substrate surface of the liquid crystal cell to be used is more preferably flat. This improves the generation of zigzag alignment defects generated in the chiral smectic C phase. It is necessary to apply the above-described alignment cell and alignment process to create a state with few smectic phase alignment defects, and to polymerize the polymer precursor in a network or dispersed state in the liquid crystal phase. However, it is difficult to completely eliminate alignment defects by the above-mentioned method, and when liquid crystal molecules are polymerized while moving with an electric field while applying an alternating current with a frequency up to several kHz, the average alignment of the liquid crystal directors observed with a polarizing microscope As a result, a uniaxially oriented element having no zigzag orientation defect can be produced. This is presumed that the layer structure of the smectic phase changed due to the alternating current and changed to a pseudo bookshelf structure.

  For the alignment used in the present invention, a liquid crystal cell having an alignment film subjected to a rubbing alignment process or an optical alignment process of a parallel alignment or an antiparallel alignment is used. The two substrates of the liquid crystal cell can be made of a transparent material having flexibility such as glass or plastic, and one of them can be an opaque material such as silicon. A transparent substrate having a transparent electrode layer can be obtained, for example, by sputtering indium tin oxide (ITO) on a transparent substrate such as a glass plate.

The color filter can be prepared by, for example, a pigment dispersion method, a printing method, an electrodeposition method, or a dyeing method. A method for producing a color filter by a pigment dispersion method will be described as an example. A curable coloring composition for a color filter is applied on the transparent substrate, subjected to patterning treatment, and cured by heating or light irradiation. By performing this process for each of the three colors red, green, and blue, a pixel portion for a color filter can be created. In addition, a pixel electrode provided with an active element such as a TFT, a thin film diode, or a metal insulator metal specific resistance element may be provided on the substrate. The said board | substrate is made to oppose so that a transparent electrode layer may become an inner side. In that case, you may adjust the space | interval of a board | substrate through a spacer. At this time, it is preferable to adjust so that the thickness of the light control layer obtained may be set to 1-100 micrometers. 2 to 10 μm is more preferable, and when a polarizing plate is used, it is preferable to adjust the product of the refractive index anisotropy Δn of the liquid crystal and the cell thickness d so that the contrast is maximized. In addition, when there are two polarizing plates, the polarizing axis of each polarizing plate can be adjusted so that the viewing angle and contrast are good. Furthermore, a retardation film for widening the viewing angle can also be used. Examples of the spacer include glass particles, plastic particles, alumina particles, and a photoresist material. Thereafter, a sealant such as an epoxy thermosetting composition is screen-printed on the substrates with a liquid crystal inlet provided, the substrates are bonded together, and heated to thermally cure the sealant.
As a method for sandwiching the polymer-stabilized liquid crystal composition between the two substrates, a normal vacuum injection method, an ODF method, or the like can be used. At this time, the polymer-stabilized liquid crystal composition only needs to be compatible with various liquid crystal compounds and the polymer precursor of the present invention, and is preferably in a uniform isotropic state or a nematic phase. In the smectic phase, handling during device fabrication becomes difficult.

  As a method for polymerizing the radically polymerizable compound, ultraviolet irradiation is suitable. As a lamp for generating ultraviolet rays, a metal halide lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, or the like can be used. Further, the wavelength of the ultraviolet rays to be irradiated is an absorption wavelength region of the photopolymerization initiator contained in the polymer-dispersed liquid crystal display element composition, and a wavelength that is not the absorption wavelength region of the contained liquid crystal composition. It is preferable to irradiate ultraviolet rays in the region. Specifically, it is preferable to cut and use ultraviolet rays of 330 nm or less using a metal halide lamp, high-pressure mercury lamp, or ultra-high pressure mercury lamp, and cut ultraviolet rays of 350 nm or less. And more preferably used.

In the case of a display, the element thus obtained can be driven by a TFT in a normal black mode operation. The halftone can be changed continuously by controlling the transmittance with voltage. A full-color display can be manufactured by additive color mixing using a color filter of the three primary colors of light, or a heeled sequential drive method in which a backlight light source of the three primary colors of light is blinked. In particular, when the auxiliary capacitor Cs is connected in parallel between the active element and the liquid crystal pixel electrode, and the liquid crystal pixel electrode is Cflc, Cs / Cfls is preferably 0.1 or more and 10 or less. In TFT driving, it is necessary to hold information written to one pixel for the time (frame rate) until it is written next. For this purpose, purification is important because ionic impurities contained in the composition of the present invention must be removed as much as possible. The purification method needs to be performed by various methods depending on the type of ionic impurities contained, and is contained in the composition or the composition using an adsorbent, a high-purity organic solvent, pure water, or the like as necessary. It is preferable that the specific resistance of the composition to be used after washing and sufficiently drying each compound is at least 10 ¹³ Ω / cm or more.

<Polymerization method of polymer stabilized liquid crystal composition>
As a polymerization method for polymerizing the composition for a polymer-stabilized liquid crystal display element of the present invention, radical polymerization, anion polymerization, cationic polymerization, and the like can be used, but polymerization is preferably performed by radical polymerization.

As the radical polymerization initiator, a thermal polymerization initiator or a photopolymerization initiator can be used, but a photopolymerization initiator is preferable. Specifically, the following compounds are preferable.
Diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- ( 2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl- Acetophenone series such as 2-dimethylamino-1- (4-morpholinophenyl) -butanone;

Benzoins such as benzoin, benzoin isopropyl ether and benzoin isobutyl ether;
Acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide;
Benzyl, methylphenylglyoxyesters;
Benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4,4′-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide, acrylated benzophenone, 3,3 ′, 4,4 ′ -Benzophenone series such as tetra (t-butylperoxycarbonyl) benzophenone, 3,3'-dimethyl-4-methoxybenzophenone;
Thioxanthone systems such as 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone;
Aminobenzophenone series such as Michler's ketone and 4,4′-diethylaminobenzophenone;
10-butyl-2-chloroacridone, 2-ethylanthraquinone, 9,10-phenanthrenequinone, camphorquinone and the like are preferable. Of these, benzyldimethyl ketal is most preferred.

  A specific example of the compound used in the polymer-stabilized liquid crystal composition used in the present invention is shown below. The polymer-stabilized liquid crystal composition contains at least one polymerizable compound (I) represented by the following general formula (Ia) as a non-liquid crystalline (meth) acrylate, and has the following general properties as a liquid crystalline (meth) acrylate. A ferroelectric liquid crystal containing at least one polymerizable compound (III) selected from the group consisting of formulas (III-a), (III-b) and (III-c), has the following general formula (II- at least one low molecular liquid crystal compound (II) represented by a) or (II-b) and a chiral compound (IV) represented by formula (IV-a) or (IV-b) Those are preferred.

<Polymerizable compound (I)>
The polymerizable compound (I) used in the polymer-stabilized liquid crystal composition used in the present invention has the following general formula (Ia):

（式（Ｉ−ａ）中、Ａ^１は水素原子又はメチル基を表し、
Ａ^２は単結合又は炭素原子数１から１５のアルキレン基（該アルキレン基中に存在する１個又は２個以上のメチレン基は、酸素原子が相互に直接結合しないものとして、それぞれ独立に酸素原子、−ＣＯ−、−ＣＯＯ−又は−ＯＣＯ−で置換されていても良く、該アルキレン基中に存在する１個又は２個以上の水素原子はそれぞれ独立にフッ素原子、メチル基又はエチル基で置換されていても良い。）を表し、Ａ^３及びＡ^６はそれぞれ独立して水素原子又は炭素原子数１から１８のアルキル基（該アルキル基中に存在する１個又は２個以上のメチレン基は、酸素原子が相互に直接結合しないものとしてそれぞれ独立に酸素原子、−ＣＯ−、−ＣＯＯ−又は−ＯＣＯ−で置換されていても良く、該アルキル基中に存在する１個又は２個以上の水素原子はそれぞれ独立にハロゲン原子又は炭素原子数１から１７のアルキル基で置換されていても良い。）を表し、

(In the formula (Ia), A ¹ represents a hydrogen atom or a methyl group,
A ² represents a single bond or an alkylene group having 1 to 15 carbon atoms (one or two or more methylene groups present in the alkylene group are each independently an oxygen atom on the assumption that oxygen atoms are not directly bonded to each other). , —CO—, —COO— or —OCO— may be substituted, and one or two or more hydrogen atoms present in the alkylene group are each independently substituted with a fluorine atom, a methyl group or an ethyl group A ³ and A ⁶ each independently represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms (one or two or more methylene groups present in the alkyl group are In addition, the oxygen atom may be independently substituted with an oxygen atom, —CO—, —COO—, or —OCO— so that the oxygen atoms are not directly bonded to each other, and one or two or more present in the alkyl group Atom may be substituted with independently a halogen atom or an alkyl group having a carbon number of 1 to 17.) Represent,

A ⁴ and A ⁷ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (one or two or more methylene groups present in the alkyl group are such that oxygen atoms are not directly bonded to each other). Each independently substituted with an oxygen atom, -CO-, -COO- or -OCO-, and one or more hydrogen atoms present in the alkyl group are each independently a halogen atom or a carbon atom. And k represents 1 to 40, B ¹ , B ² and B ³ each independently represent a hydrogen atom or a carbon atom having 1 to 10 carbon atoms. A linear or branched alkyl group (one or two or more methylene groups present in the alkyl group are each independently an oxygen atom, —CO—, —COO, assuming that the oxygen atoms are not directly bonded to each other. Or may be substituted with -OCO-), or formula (I-b)

(In formula (Ib), A ⁹ represents a hydrogen atom or a methyl group,
A ⁸ is a single bond or an alkylene group having 1 to 15 carbon atoms (one or two or more methylene groups present in the alkylene group are each independently an oxygen atom, assuming that oxygen atoms are not directly bonded to each other). , —CO—, —COO— or —OCO— may be substituted, and one or two or more hydrogen atoms present in the alkylene group are each independently substituted with a fluorine atom, a methyl group or an ethyl group Represents a group represented by: However, the number of 2 k + 1 B ¹ , B ^2, and B ³ that is the group represented by the general formula (Ib) is 0 to 3. And a polymerizable compound (I) having a glass transition temperature of −100 ° C. to 25 ° C. of the polymerized product of the polymerizable compound.

In the present invention, unless otherwise specified, the “alkylene group” is a divalent group “— (CH ₂ ) _n, wherein one hydrogen atom is removed from carbon atoms at both ends of an aliphatic linear hydrocarbon. -"(Where n is an integer of 1 or more), and the substitution from a hydrogen atom to a halogen atom or an alkyl group, or from a methylene group to an oxygen atom, -CO-, -COO- or -OCO- If there is a substitution, this shall be specifically refused. Further, the “alkylene chain length” refers to n in the general formula “— (CH ₂ ) _n —” of the “alkylene group”.
As a preferable structure of the polymerizable compound (I) represented by the general formula (Ia), the following general formula (Ic)

(In formula (Ic), A ¹¹ and A ¹⁹ each independently represent a hydrogen atom or a methyl group, and A ¹² and A ¹⁸ each independently represent a single bond or an alkylene group having 1 to 15 carbon atoms ( One or more methylene groups present in the alkylene group are each independently substituted with an oxygen atom, -CO-, -COO- or -OCO-, assuming that the oxygen atoms are not directly bonded to each other. And one or two or more hydrogen atoms present in the alkylene group may each independently be substituted with a fluorine atom, a methyl group or an ethyl group).

A ¹³ and A ¹⁶ are each independently a linear alkyl group having 2 to 20 carbon atoms (one or two or more methylene groups present in the linear alkyl group are such that oxygen atoms are not directly bonded to each other) as things each independently represent an oxygen atom, -CO -, -. the COO- or may be substituted with -OCO-) ^{represents, a 14} and ^{a 17} from each independent number hydrogen atom or a carbon atom 1 10 alkyl groups (one or two or more methylene groups present in the alkyl group are each independently an oxygen atom, —CO—, —COO— or —OCO—, as oxygen atoms are not directly bonded to each other). And one or more hydrogen atoms present in the alkyl group may each independently be substituted with a halogen atom or an alkyl group having 1 to 9 carbon atoms). A ¹⁵ represents an alkylene group having 9 to 16 carbon atoms (in the alkylene group, at least 1 to 5 methylene groups, each of the hydrogen atoms in the methylene group is independently a carbon atom, It is substituted with a linear or branched alkyl group having a number of 1 to 10. One or more methylene groups present in the alkylene group are independently considered as those in which oxygen atoms are not directly bonded to each other. An oxygen atom, -CO-, -COO- or -OCO- may be substituted). ), A compound represented by the general formula (Id)

（式（Ｉ−ｄ）中、Ａ^２１及びＡ^２２はそれぞれ独立して水素原子又はメチル基を表し、ａは、６〜２２の整数を表す。）で表される化合物、一般式（Ｉ−ｅ）

(In Formula (Id), A ²¹ and A ²² each independently represents a hydrogen atom or a methyl group, and a represents an integer of 6 to 22), a general formula (I- e)

（式（Ｉ−ｅ）中、Ａ^３１及びＡ^３２はそれぞれ独立して水素原子又はメチル基を表し、ｂ及びｃはそれぞれ独立して１〜１０の整数を表し、ｄは１〜１０の整数を表し、ｅは０〜６の整数を表す。）で表される化合物、及び一般式（Ｉ−ｆ）

(In Formula (Ie), A ³¹ and A ³² each independently represent a hydrogen atom or a methyl group, b and c each independently represent an integer of 1 to 10, and d is an integer of 1 to 10) And e represents an integer of 0 to 6), and the general formula (If)

（式（Ｉ−ｆ）中、Ａ^４１及びＡ^４２はそれぞれ独立して水素原子又はメチル基を表し、ｍ、ｎ、ｐ及びｑはそれぞれ独立して１〜１０の整数を表す。）で表される化合物からなる群から選ばれる１種以上が挙げられる。これらの中でも、式（Ｉ−ｃ）で表される化合物を含むことが好ましい。

(In formula (If), A ⁴¹ and A ⁴² each independently represents a hydrogen atom or a methyl group, and m, n, p and q each independently represents an integer of 1 to 10). 1 type or more chosen from the group which consists of a compound to be mentioned. Among these, it is preferable that the compound represented by Formula (Ic) is included.

As a preferable structure of the polymerizable compound represented by the general formula (Ic), both A ¹¹ and A ¹⁹ are preferably hydrogen atoms. The effect of the present invention is exhibited even in a compound in which these substituents A ¹¹ or A ¹⁹ are a methyl group, but a compound in which a hydrogen atom is used is advantageous in that the polymerization rate becomes faster.

A ¹² and A ¹⁸ are preferably each independently a single bond or an alkylene group having 1 to 3 carbon atoms. The distance between the two polymerizable functional groups can be adjusted by independently changing the length of the carbon number of A ¹² and A ¹⁸ and A ¹⁵ , respectively. The feature of the compound represented by the general formula (Ic) is that the distance between the polymerizable functional groups (distance between the crosslinking points) is long, but if this distance is too long, the polymerization rate becomes extremely slow. Therefore, there is an upper limit on the distance between the polymerizable functional groups. On the other hand, the distance between the two side chains of A ¹³ and A ¹⁶ also affects the mobility of the main chain. That is, if the distance between A ¹³ and A ¹⁶ is short, the side chains A ¹³ and A ¹⁶ will interfere with each other, resulting in a decrease in mobility. Accordingly, the distance between polymerizable functional groups of the compound represented by the general formula ^{(I-c) A 12,} A 18, and is determined by the sum of ^{A 15,} A rather than these lengthening the ^{A 12} and ^{A 18} It is preferable to lengthen ¹⁵ .

On the other hand, in the side chains A ¹³ , A ¹⁴ , A ¹⁶ and A ¹⁷ , it is preferable that the length of these side chains has the following aspect.
In the general formula (Ic), A ¹³ and A ¹⁴ are bonded to the same carbon atom of the main chain. When these lengths are different, the longer side chain is referred to as A ¹³ ( If the length and the length of ^{a 14} of a ¹³ are equal, one to one and ^{a 13).} Similarly, when the length of the length and A ¹⁷ of A ¹⁶ are different, if the length and the length of A ¹⁷ in the longer side chain of is referred to as A ¹⁶ (A ¹⁶ are equal, either the one and a ^16).

In the present application, such A ¹³ and A ¹⁶ are each independently a linear alkyl group having 2 to 20 carbon atoms (one or two or more methylene groups present in the linear alkyl group are oxygen As the atoms are not directly bonded to each other, each may be independently substituted with an oxygen atom, —CO—, —COO—, or —OCO—. A straight-chain alkyl group having 2 to 18 atoms (one or two or more methylene groups present in the straight-chain alkyl group independently represent an oxygen atom, -CO -, -COO- or -OCO- may be substituted.), More preferably each independently a linear alkyl group having 3 to 15 carbon atoms (present in the linear alkyl group). 1 piece or Two or more of the methylene groups is, as the oxygen atoms are not directly bonded to each other, each independently represent an oxygen atom, -CO -, -. The COO- or may be substituted with -OCO-) is.

  Since the side chain has higher mobility than the main chain, its presence contributes to improvement of the mobility of the polymer chain at low temperature, but as mentioned above, spatial interference occurs between the two side chains. On the contrary, motility decreases. In order to prevent such spatial interference between side chains, it is effective to increase the distance between the side chains and to shorten the side chain length within a necessary range.

Furthermore, for A ¹⁴ and A ¹⁷ , in the present application, each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (one or two or more methylene groups present in the alkyl group have an oxygen atom Each may be independently substituted with an oxygen atom, —CO—, —COO—, or —OCO— so that one or two or more hydrogen atoms present in the alkyl group are each independently May be substituted with a halogen atom or an alkyl group having 1 to 9 carbon atoms.), Preferably each independently a hydrogen atom or an alkyl group having 1 to 7 carbon atoms (the alkyl group). One or more methylene groups present therein are each independently oxygen atoms, —CO—, —COO— or —OCO—, as oxygen atoms are not directly bonded to each other. Is may be substituted.),

  More preferably, they are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms (one or two or more methylene groups present in the alkyl group are independent as those in which oxygen atoms are not directly bonded to each other). May be substituted with an oxygen atom, —CO—, —COO— or —OCO—, and more preferably each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms (the alkyl group). One or two or more methylene groups present therein may be each independently substituted with an oxygen atom, —CO—, —COO— or —OCO— so that the oxygen atoms are not directly bonded to each other. ).

This A ¹⁴ and A ¹⁷ also, the possible length too long is not preferable for inducing the spatial interference between side chains. On the other hand, when A ¹⁴ and A ¹⁷ are alkyl chains having a short length, they can be side chains having high mobility and have a function of inhibiting the proximity of adjacent main chains. It is thought that it acts to prevent interference between polymer main chains, and it is thought that the mobility of the main chains is enhanced. This is effective in improving the display characteristics in the low temperature region of the device.

A ¹⁵ located between the two side chains is preferably longer in terms of changing the distance between the side chains and increasing the distance between the crosslinking points to lower the glass transition temperature. However to come formula compatibility with the liquid crystal composition has too high a molecular weight (I-c) compounds represented by is reduced when A ¹⁵ is too long, and the polymerization rate slows down too phase separation The length is naturally set to an upper limit because of adverse effects on the length.

Therefore, in the present invention, A ¹⁵ represents an alkylene group having 9 to 16 carbon atoms (in the methylene group of at least 1 to 5 carbon atoms present in the alkylene group, one of the hydrogen atoms in the methylene group is Independently substituted with a linear or branched alkyl group having 1 to 10 carbon atoms, wherein one or more methylene groups present in the alkylene group are such that oxygen atoms are not directly bonded to each other. And each may be independently substituted with an oxygen atom, —CO—, —COO— or —OCO—.

That is, in the present invention, the alkylene chain length of A ¹⁵ is preferably 9 to 16 carbon atoms. A ¹⁵ has a structure in which a hydrogen atom in an alkylene group is substituted with an alkyl group having 1 to 10 carbon atoms as a structural feature. The number of substitution of the alkyl group is 1 or more and 5 or less, preferably 1 to 3, and more preferably 2 or 3 substitutions. The number of carbon atoms of the alkyl group to be substituted is preferably 1 to 5, and more preferably 1 to 3.

  The compound represented by the general formula (Ia) is described in Tetrahedron Letters, Vol. 30, pp 4985, Tetrahedron Letters, Vol. 23, No. 6, pp 681-684, and Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 34, pp217-225 and the like.

For example, in the general formula (I-c), Compound A ¹⁴ and A ¹⁷ are hydrogen, a compound having a plurality of epoxy groups, polymerizable acrylic acid or methacrylic acid having an active hydrogen reactive with epoxy groups It can be obtained by reacting with a compound to synthesize a polymerizable compound having a hydroxyl group and then reacting with a saturated fatty acid.
Furthermore, by reacting a compound having a plurality of epoxy groups with a saturated fatty acid, synthesizing a compound having a hydroxyl group, and then reacting with a polymerizable compound such as an acrylate chloride having a group capable of reacting with a hydroxyl group. Can be obtained.

When the radically polymerizable compound is, for example, A ¹⁴ and A ^{17 in} the general formula (Ic) are alkyl groups and A ¹² and A ¹⁸ are methylene groups having 1 carbon atom, an oxetane group is selected. A method of reacting a compound having a plurality of compounds with a fatty acid chloride or a fatty acid capable of reacting with an oxetane group, and further reacting with a polymerizable compound having active hydrogen such as acrylic acid, a compound having one oxetane group, It can be obtained by a method of reacting a polyvalent fatty acid chloride or a fatty acid capable of reacting with an oxetane group, and further reacting with a polymerizable compound having active hydrogen such as acrylic acid.

In the case where A ¹² and A ¹⁸ in the general formula (Ic) are an alkylene group having 3 carbon atoms (propylene group; —CH ₂ CH ₂ CH ₂ —), a plurality of furan groups are used instead of the oxetane group. It can obtain by using the compound which has. Further, when A ¹² and A ¹⁸ in the general formula (Ic) are an alkylene group having 4 carbon atoms (butylene group; —CH ₂ CH ₂ CH ₂ CH ₂ —), a pyran group is used instead of the oxetane group. It can obtain by using the compound which has two or more.
Specific examples of the polymerizable compound (I) can include the following (I-1) to (I-8).

＜低分子液晶化合物（ＩＩ）＞
本発明の高分子安定化液晶組成物に用いられる低分子液晶化合物（ＩＩ）は、下記一般式（ＩＩ−ａ）又は（ＩＩ−ｂ）

<Low molecular liquid crystal compound (II)>
The low-molecular liquid crystal compound (II) used in the polymer-stabilized liquid crystal composition of the present invention has the following general formula (II-a) or (II-b)

(In the formulas (II-a) and (II-b), R ¹ and R ² each independently represents an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms (the alkyl group or alkenyl group). 1 or 2 or more methylene groups present in the group may be each independently substituted with an oxygen atom, assuming that the oxygen atoms are not directly bonded to each other).
C ¹ is a 1,4-phenylene group, a 1,4-cyclohexylene group, or a 1,3-dioxane-2,5-diyl group (of which 1,4-phenylene group is unsubstituted) Or a fluorine atom, a chlorine atom, a methyl group, a trifluoromethyl group, or a trifluoromethoxy group as a substituent.
C ² and C ³ are each independently 1,4-phenylene group, 1,4-cyclohexylene group, pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, pyridazine-3,6- Diyl group, 1,3-dioxane-2,5-diyl group, cyclohexene-1,4-diyl group, decahydronaphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6 -Diyl group, 2,6-naphthylene group or indane-2,5-diyl group (among these groups 1,4-phenylene group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, The 2,6-naphthylene group and indan-2,5-diyl group are unsubstituted or have one fluorine atom, chlorine atom, methyl group, trifluoromethyl group or trifluoromethoxy group as a substituent. May have two or more.) Represent,
Z ¹ and Z ² are each independently a single bond, —CH ₂ CH ₂ —, —CH ₂ O—, —OCH ₂ —, —CH ₂ CH ₂ O—, —OCH ₂ CH ₂ —, —CH _2. CH ₂ CH ₂ O—, —OCH ₂ CH ₂ CH ₂ —, —CH═CH—, —C≡C—, —CF ₂ O—, —OCF ₂ —, —COO— or —OCO— are represented,
X ¹ represents a fluorine atom, a chlorine atom, a trifluoromethyl group, a trifluoromethoxy group, a difluoromethyl group, an isocyanate group, or a cyano group,
n ¹ represents 0, 1 or 2. However, when n ¹ represents 2, a plurality of C ¹ and Z ¹ may be the same or different. It is a compound (II) represented by this.

The compound represented by the general formula (II-a) or (II-b) is specific in terms of a wide liquid crystal temperature range, nematic stability and compatibility in a low temperature range, a high dielectric constant, and a high specific resistance value. The compounds represented by the following general formula (Va), general formula (VI-a), general formula (VI-b), general formula (VII-a) and general formula (VII-b) Is preferred.
<Polymerizable liquid crystal compound (III)>
The polymerizable liquid crystal compound (III) used in the polymer-stabilized liquid crystal composition of the present invention is selected from the group consisting of the following general formula (III-a), general formula (III-b), and general formula (III-c). The selected compound is preferred.
Formula (III-a)

(In Formula (III-a), R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group, and C ⁴ and C ⁵ each independently represent a 1,4-phenylene group or 1,4-cyclohexene. Xylene group, pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, pyridazine-3,6-diyl group, 1,3-dioxane-2,5-diyl group, cyclohexene-1,4-diyl Group, decahydronaphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, 2,6-naphthylene group or indane-2,5-diyl group (these groups Of which 1,4-phenylene group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, 2,6-naphthylene group and indan-2,5-diyl group are unsubstituted or Fluorine atom as a substituent, salt Which can have one or more elemental atoms, methyl groups, trifluoromethyl groups or trifluoromethoxy groups),

Z ³ and Z ⁵ are each independently a single bond or an alkylene group having 1 to 15 carbon atoms (one or two or more methylene groups present in the alkylene group are such that oxygen atoms are not directly bonded to each other) Each independently may be substituted with an oxygen atom, -CO-, -COO- or -OCO-, and one or more hydrogen atoms present in the alkylene group are each independently a fluorine atom, Which may be substituted with a methyl group or an ethyl group)
Z ⁴ is a single bond, —CH ₂ CH ₂ —, —CH ₂ O—, —OCH ₂ —, —CH ₂ CH ₂ O—, —OCH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ O—, _{-OCH 2 CH 2 CH 2 -,} - CH 2 CH 2 OCO -, - COOCH 2 CH 2 -, - CH 2 CH 2 COO -, - OCOCH 2 CH 2 -, - CH = CH -, - C≡C- _{, -CF 2 O -, - OCF} 2 -, - COO- or an -OCO-,
n ² represents 0, 1 or 2. However, when n ² represents 2, a plurality of C ⁴ and Z ⁴ may be the same or different. ),
Formula (III-b)

(In formula (III-b), R ⁵ and R ₆ each independently represent a hydrogen atom or a methyl group,
C ⁶ is 1,4-phenylene group, 1,4-cyclohexylene group, pyridine-2,5-diyl group, pyrimidine-2,5-diyl group, pyridazine-3,6-diyl group, 1,3- Dioxane-2,5-diyl group, cyclohexene-1,4-diyl group, decahydronaphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, 2,6 A naphthylene group or an indan-2,5-diyl group (among these groups 1,4-phenylene group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, 2,6-naphthylene group and The indane-2,5-diyl group can be unsubstituted or have one or more fluorine, chlorine, methyl, trifluoromethyl or trifluoromethoxy groups as substituents. Represents)

C ⁷ and C ⁸ are each independently benzene-1,2,4-triyl group, benzene-1,3,4-triyl group, benzene-1,3,5-triyl group, cyclohexane-1,2,4. -Represents a triyl group, a cyclohexane-1,3,4-triyl group or a cyclohexane-1,3,5-triyl group,
Z ⁶ and Z ⁸ are each independently a single bond or an alkylene group having 1 to 15 carbon atoms (one or two or more methylene groups present in the alkylene group are such that oxygen atoms are not directly bonded to each other) Each independently may be substituted with an oxygen atom, -CO-, -COO- or -OCO-, and one or more hydrogen atoms present in the alkylene group are each independently a fluorine atom, Which may be substituted with a methyl group or an ethyl group)

Z ⁷ and Z ⁹ are each independently a single bond, —CH ₂ CH ₂ —, —CH ₂ O—, —OCH ₂ —, —CH ₂ CH ₂ O—, —OCH ₂ CH ₂ —, —CH ₂ CH _{2. CH 2 O -, - OCH 2} CH 2 CH 2 -, - CH 2 CH 2 OCO -, - COOCH 2 CH 2 -, - CH 2 CH 2 COO -, - OCOCH 2 CH 2 -, - CH = CH-, —C≡C—, —CF ₂ O—, —OCF ₂ —, —COO— or —OCO— is represented, and n ³ represents 0, 1 or 2. However, when n ³ represents 2, a plurality of C ⁶ and Z ⁷ may be the same or different, and n ⁵ and n ⁶ each independently represent 1, 2 and 3. )
Formula (III-c)

（式（ＩＩＩ−ｃ）中、Ｒ^７は水素原子又はメチル基を表し、
６員環Ｔ^１、Ｔ^２及びＴ^３はそれぞれ独立的に、

(In formula (III-c), R ⁷ represents a hydrogen atom or a methyl group,
6-membered rings T ¹ , T ² and T ³ are each independently

(Wherein m represents an integer of 1 to 4), n ⁴ represents an integer of 0 or 1, Y ¹ and Y ² are each independently a single bond, —CH ₂ CH ₂ —, _{-CH 2 O -, - OCH 2} -, - COO -, - OCO -, - C≡C -, - CH = CH -, - CF = CF -, - (CH 2) 4 -, - CH 2 CH 2 CH ₂ O—, —OCH ₂ CH ₂ CH ₂ —, —CH ₂ ═CHCH ₂ CH ₂ — or —CH ₂ CH ₂ CH═CH—
Y ³ represents a single bond, —COO—, or —OCO—,
R ⁸ represents a hydrocarbon group having 1 to 18 carbon atoms. )
More specifically, general formulas (III-d) and (III-e)

（式（ＩＩＩ−ｄ）及び（ＩＩＩ−ｅ）中、ｍ^１は、０又は１を表し、
Ｙ^１１及びＹ^１２はそれぞれ独立して単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表し、Ｙ^１３及びＹ^１４はそれぞれ独立して−ＣＯＯ−又は−ＯＣＯ−を表し、
Ｙ^１５及びＹ^１６はそれぞれ独立して−ＣＯＯ−又は−ＯＣＯ−を表し、

(In the formulas (III-d) and (III-e), m ¹ represents 0 or 1,
Y ¹¹ and Y ¹² each independently represent a single bond, —O—, —COO— or —OCO—, Y ¹³ and Y ¹⁴ each independently represent —COO— or —OCO—,
Y ¹⁵ and Y ¹⁶ each independently represent —COO— or —OCO—,

r and s each independently represent an integer of 2 to 14. The 1,4-phenylene group present in the formula may be unsubstituted or have one or more fluorine, chlorine, methyl, trifluoromethyl or trifluoromethoxy groups as substituents. it can. It is preferable to use a compound represented by any one of (2), since an optically anisotropic body excellent in mechanical strength and heat resistance can be obtained.
Specific examples of the compound represented by the general formula (III-a) can include the following (III-1) to (III-10).

(Wherein j and k each independently represents an integer of 2 to 14)
Specific examples of the compound represented by any one of the general formulas (III-d) and (III-e) can be listed in the following (III-11) to (III-20).

(Wherein j and k each independently represents an integer of 2 to 14)
Specific examples of the compound represented by the general formula (III-b) can include the following (III-21) to (III-10).

（式中、ｊ及びｋはそれぞれ独立的に２〜１４の整数を表す。）
＜カイラル化合物（ＩＶ）＞
本発明に用いられる高分子安定化液晶組成物におけるカイラル化合物（ＩＶ）は、一般式（ＩＶ−ａ）又は（ＩＶ−ｂ）

(Wherein j and k each independently represents an integer of 2 to 14)
<Chiral compound (IV)>
The chiral compound (IV) in the polymer-stabilized liquid crystal composition used in the present invention is represented by the general formula (IV-a) or (IV-b).

(In the formulas (IV-a) and (IV-b), R ⁹ represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms (one in the alkyl group or alkenyl group). Or two or more methylene groups may be independently substituted with oxygen atoms, assuming that the oxygen atoms are not directly bonded to each other.
C ⁸ and C ⁹ are each independently 1,4-phenylene group, 1,4-cyclohexylene group, pyrimidine-2,5-diyl group (among these groups, 1,4-phenylene group or 1,4 -The cyclohexylene group is unsubstituted or can have one or more fluorine atom, chlorine atom, methyl group, cyano group, trifluoromethyl group or trifluoromethoxy group as a substituent. Represents

Z ⁹ represents a single bond, —CH ₂ CH ₂ —, —C≡C—, —CF ₂ O—, —COO— or —OCO—,
Y ⁴ and Y ⁵ each independently represent a single bond, an oxygen atom, a methylene group, —OCH ₂ —, —COO—, —OCO—, —OCH ₂ CH ₂ — or —OCOCH ₂ —.
n ⁵ represents 0, 1 or 2. However, when n ⁵ represents 2, a plurality of C ⁸ and Z ⁹ may be the same or different.
X ⁴ and X ⁵ are each independently selected from the general formulas (IV-c) to (IV-h)

Represents a group represented by any formula of However, in formulas (IV-c) to (IV-h), * represents that the carbon atom is an asymmetric carbon atom, and the four groups bonded to each other are different from each other.
R ^c , R ^d , R ^e , R ^f and R ^g are each independently an alkyl group having 2 to 20 carbon atoms (one or two or more methylene groups present in the alkyl group are oxygen atoms And may be each independently substituted with an oxygen atom, -CO-, -COO-, or -OCO-) as not being directly bonded to each other.
X ^c , X ^d and Y ^d each independently represent a fluorine atom, a chlorine atom, a methyl group or a cyano group,
X ^e and Y ^e each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group or a cyano group,

X ^h and Y ^h each independently represent a fluorine atom, a chlorine atom, a methyl group or a cyano group,
Z ^d represents a single bond or a methylene group,
Z ^e is an oxygen atom or a group represented by —OC (R ^e1 ) (R ^e2 ) O— (wherein R ^e1 and R ^e2 each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms) .) represents, ^{Z f} represents a carbonyl group or -CH ^{(R f1)} - group represented by ^{(wherein, R f1} represents a represents) an alkyl group having 1 to 10 carbon hydrogen atom or a carbon atom.
Z ^g represents —OCO—, —COO—, —CH ₂ O— or —OCH ₂ —. It is a chiral compound (IV) represented by this.
Further, the chiral compound (IV) may be the general formula (IV-i),

（式（ＩＶ−ｉ）、Ｒ^１０及びＲ^１１はそれぞれ独立して炭素原子数１から１８のアルキル基又は炭素原子数２から１０のアルケニル基（該アルキル基又はアルケニル基中に存在する１個又は２個以上のメチレン基は、酸素原子が相互に直接結合しないものとして、それぞれ独立に酸素原子で置換されていても良い。）を表し、
Ｃ^１０、Ｃ^１１、Ｃ^１２、及びＣ^１３はそれぞれ独立して１，４−フェニレン基、１，４−シクロへキシレン基、ピリミジン−２，５−ジイル基（これらの基のうち１，４−フェニレン基又は１，４−シクロへキシレン基は、非置換であるか又は置換基としてフッ素原子、塩素原子、メチル基、シアノ基、トリフルオロメチル基若しくはトリフルオロメトキシ基を１個若しくは２個以上有することができる。）を表し、
Ｚ^１０及びＺ^１１はそれぞれ独立して単結合、−ＣＨ_２ＣＨ_２−、−Ｃ≡Ｃ−、−ＣＦ_２Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表し、
Ｙ^１０及びＹ^１１はそれぞれ独立して単結合、酸素原子、炭素数１から１０のアルキレン基、−ＯＣＨ_２−、−ＣＯＯ−、−ＯＣＯ−、−ＯＣＨ_２ＣＨ_２−又は−ＯＣＯＣＨ_２−を表し、ｎ^１１及びｎ^１２は、それぞれ独立して１又は２を表す。
Ｘ^１０はそれぞれ独立して、一般式（ＩＶ−ｊ）から（ＩＶ−ｎ）

(Formula (IV-i), R ¹⁰ and R ¹¹ are each independently an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 10 carbon atoms (one in the alkyl group or alkenyl group). Or two or more methylene groups may be independently substituted with oxygen atoms, assuming that the oxygen atoms are not directly bonded to each other.
C ¹⁰ , C ¹¹ , C ¹² , and C ¹³ are each independently 1,4-phenylene group, 1,4-cyclohexylene group, pyrimidine-2,5-diyl group (of these groups, 1, 4 -The phenylene group or 1,4-cyclohexylene group is unsubstituted or has one or two fluorine atom, chlorine atom, methyl group, cyano group, trifluoromethyl group or trifluoromethoxy group as a substituent. It can have the above)
Z ¹⁰ and Z ¹¹ each independently represent a single bond, —CH ₂ CH ₂ —, —C≡C—, —CF ₂ O—, —COO— or —OCO—,
Y ¹⁰ and Y ¹¹ each independently represent a single bond, an oxygen atom, an alkylene group having 1 to 10 carbon atoms, —OCH ₂ —, —COO—, —OCO—, —OCH ₂ CH ₂ — or —OCOCH ₂ —. N ¹¹ and n ¹² each independently represent 1 or 2.
X ¹⁰ each independently represents a formula (IV-j) to (IV-n)

のいずれかの式であらわされる基を表す。
ただし、式（ＩＶ−ｊ）から（ＩＶ−ｎ）中、＊は炭素原子が不斉炭素原子であることを表し、Ｒ^ｆ、Ｒ^ｇ、Ｒ^ｈ、Ｒ^ｉ、R^ｊ、Ｒ^ｋ、Ｒ^ｌ、Ｒ^ｍ、Ｒ^ｎ及びＲ^ｏはそれぞれ独立して炭素原子数０から１８のアルキレン基（該アルキル基中に存在する１個又は２個以上のメチレン基は、酸素原子が相互に直接結合しないものとして、それぞれ独立に酸素原子、−ＣＯ−、−ＣＯＯ−又は−ＯＣＯ−で置換されていても良い。）を表し、

Represents a group represented by any formula of
However, in formulas (IV-j) to (IV-n), * represents that the carbon atom is an asymmetric carbon atom, and R ^f , R ^g , R ^h , R ⁱ , R ^j , R ^k , R ^l , R ^m , R ^n, and R ^o are each independently an alkylene group having 0 to 18 carbon atoms (one or two or more methylene groups present in the alkyl group have oxygen atoms directly bonded to each other) Each may be independently substituted with an oxygen atom, -CO-, -COO-, or -OCO-).

X ^c , X ^d and Y ^d each independently represent a fluorine atom, chlorine atom, methyl group or cyano group, and X ^e and Y ^e each independently represent a hydrogen atom, fluorine atom, chlorine atom, methyl group or cyano group. Z ^d represents a single bond or a methylene group, Z ^e represents an oxygen atom or a group represented by —OC (R ^e1 ) (R ^e2 ) O— (wherein R ^e1 and R ^e2 are independent of each other). Represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms),
Z ^f represents a carbonyl group or -CH ^{(R f1)} - group represented by ^{(wherein, R f1} represents an alkyl group having 1 to 10 carbon hydrogen atom or a carbon atom.) Represent,
Z ^g represents —OCO—, —COO—, —CH ₂ O— or —OCH ₂ —. It is a chiral compound (IV) represented by this.
<Low molecular liquid crystal compound represented by general formula (VI-a) and general formula (VI-b)>
When the specific example of the low molecular liquid crystal compound (II) used for the polymer stabilization liquid crystal composition of this invention is shown, (II) is following general formula (VI-a) or (VI-b).

(In the formula (VI-a), R ²¹ represents an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms (one or two or more present in the alkyl group or alkenyl group). A methylene group may be substituted with an oxygen atom, assuming that the oxygen atoms are not directly bonded to each other);
C ²¹ is a 1,4-phenylene group or a 1,4-cyclohexylene group (the 1,4-phenylene group is unsubstituted or substituted with one or more fluorine atoms, chlorine atoms, methyl Group or a trifluoromethyl group or a trifluoromethoxy group).

Six-membered ring Y ²¹ represents a benzene ring or a cyclohexane ring, X ²¹ represents a fluorine atom, a chlorine atom, an isocyanate group, a trifluoromethyl group, a trifluoromethoxy group, or a difluoromethoxy group,
X ²² to X ²⁶ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a trifluoromethyl group or a trifluoromethoxy group,
Z ²¹ represents a single bond or —CH ₂ CH ₂ —,
Z ²² represents a single bond, —CH ₂ CH ₂ — or —CF ₂ O—,
n ²¹ represents 0 or 1; )

(In the formula (VI-b), R ³¹ represents an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms (one or two or more present in the alkyl group or alkenyl group). A methylene group may be substituted with an oxygen atom, assuming that the oxygen atoms are not directly bonded to each other);
C ³¹ is a 1,4-phenylene group or a 1,4-cyclohexylene group (the 1,4-phenylene group is unsubstituted or substituted with one or more fluorine atoms, chlorine atoms, methyl Group or a trifluoromethyl group or a trifluoromethoxy group).

Six-membered ring Y ³¹ represents a benzene ring or a cyclohexane ring,
X ³¹ represents a fluorine atom, a chlorine atom, an isocyanate group, a trifluoromethyl group, a trifluoromethoxy group or a difluoromethoxy group,
X ³² to X ³⁶ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a trifluoromethyl group or a trifluoromethoxy group,
Z ³¹ represents a single bond or —CH ₂ CH ₂ —.
Z ³² represents a single bond, —CH ₂ CH ₂ — or —CF ₂ O—,
n ³¹ represents 0 or 1; )

In General Formula (VI-a) and General Formula (VI-b), R ²¹ and R ³¹ are each an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms (the alkyl group or alkenyl group). 1 or 2 or more methylene groups present therein may preferably be substituted with oxygen atoms so that the oxygen atoms are not directly bonded to each other.
The alkyl group or alkenyl group has the formula (VI-c)

（式（ＶＩ−ｃ）中の各構造式は右端で直接もしくは酸素原子を介して環に連結しているものとする。）で表されるアルケニル基又は炭素原子数５から１２のアルキル基がより好ましい。
Ｃ^２１及びＣ^３１としては、１，４−シクロヘキシレン基が好ましい。
Ｚ^２１及びＺ^３１としては、単結合が好ましい。
Ｘ^２１及びＸ^３１としては、フッ素原子もしくはトリフルオロメトキシ基が好ましく、フッ素原子がより好ましい。
具体的には、一般式（ＶＩ−１）から一般式（ＶＩ−３３）で表される化合物が好ましい。

(Each structural formula in the formula (VI-c) is connected to the ring directly or through an oxygen atom at the right end) or an alkenyl group or an alkyl group having 5 to 12 carbon atoms More preferred.
As C ²¹ and C ³¹ , a 1,4-cyclohexylene group is preferable.
Z ²¹ and Z ³¹ are preferably a single bond.
X ²¹ and X ³¹ are preferably a fluorine atom or a trifluoromethoxy group, and more preferably a fluorine atom.
Specifically, compounds represented by general formula (VI-1) to general formula (VI-33) are preferable.

(In the formula, R ²² and R ³² represent an alkyl group having 1 to 18 carbon atoms.)
<Compounds Represented by General Formula (VII-a) and General Formula (VII-b)>
Specific examples of the low-molecular liquid crystal compound (II) used in the polymer-stabilized liquid crystal composition of the present invention are shown in the following general formulas (VII-a) and (VII-b).

(In the formula (VII-a), R ⁴¹ represents an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms (one or two or more present in the alkyl group or alkenyl group). A methylene group may be substituted with an oxygen atom, assuming that the oxygen atoms are not directly bonded to each other);
C ⁴¹ is a 1,4-phenylene group or a 1,4-cyclohexylene group (the 1,4-phenylene group is unsubstituted or has one or more fluorine atoms, chlorine atoms, methyl Group or a trifluoromethyl group or a trifluoromethoxy group).

Six-membered ring Y ⁴¹ represents a benzene ring or a cyclohexane ring,
X ⁴¹ represents a fluorine atom, a chlorine atom, an isocyanate group, a trifluoromethyl group, a trifluoromethoxy group or a difluoromethoxy group,
X ⁴² to X ⁴⁵ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a trifluoromethyl group or a trifluoromethoxy group,
Z ⁴¹ represents a single bond or —CH ₂ CH ₂ —.
Z ⁴² represents a single bond, _-CH 2 CH ₂ -, or _-CF 2 O-,
n ⁴¹ represents 0 or 1; )

（式（ＶＩＩ−ｂ）中、Ｒ^５１は、炭素原子数１から１８のアルキル基又は炭素原子数２から１８のアルケニル基（該アルキル基又はアルケニル基中に存在する１個又は２個以上のメチレン基は、酸素原子が相互に直接結合しないものとして、酸素原子で置換されていてもよい。）を表し、
Ｃ^５１は、１，４−フェニレン基又は１，４−シクロヘキシレン基（該１，４−フェニレン基は非置換であるか又は置換基として１個又は２個以上のフッ素原子、塩素原子、メチル基又はトリフルオロメチル基又はトリフルオロメトキシ基を有することができる。）を表し、

(In the formula (VII-b), R ⁵¹ represents an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms (one or two or more present in the alkyl group or alkenyl group). A methylene group may be substituted with an oxygen atom, assuming that the oxygen atoms are not directly bonded to each other);
C ⁵¹ represents a 1,4-phenylene group or a 1,4-cyclohexylene group (the 1,4-phenylene group is unsubstituted or has one or more fluorine atoms, chlorine atoms, methyl groups as substituents) Group or a trifluoromethyl group or a trifluoromethoxy group).

Six-membered ring Y ⁵¹ represents a benzene ring or a cyclohexane ring,
X ⁵¹ represents a fluorine atom, a chlorine atom, an isocyanate group, a trifluoromethyl group, a trifluoromethoxy group or a difluoromethoxy group,
X ⁵² to X ⁵⁵ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a trifluoromethyl group or a trifluoromethoxy group,
Z ⁵¹ represents a single bond or —CH ₂ CH ₂ —,
Z ⁵² represents a single bond, —CH ₂ CH ₂ — or —CF ₂ O—,
n ⁵¹ represents 0 or 1; )

In the general formula (VII-a) and the general formula (VII-b), R ⁴¹ and R ⁵¹ are each an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 6 carbon atoms (the alkyl group or alkenyl group). 1 or 2 or more methylene groups present therein may preferably be substituted with oxygen atoms so that the oxygen atoms are not directly bonded to each other.
The alkyl group or alkenyl group has the formula (VII-c)

（式（ＶＩＩ−ｃ）中の構造式は右端で直接もしくは酸素原子を介して環に連結しているものとする。）で表されるアルケニル基又は炭素原子数５から１２のアルキル基がより好ましい。
Ｃ^４１及びＣ^５１としては、１，４−シクロヘキシレン基が好ましい。
Ｚ^４１及びＺ^５１としては、単結合が好ましい。
Ｘ^４１及びＸ^５１としては、フッ素原子もしくはトリフルオロメトキシ基が好ましく、フッ素原子がより好ましい。
具体的には一般式（ＶＩＩ−１）から一般式（ＶＩＩ−４２）で表される化合物が好ましい。

(The structural formula in the formula (VII-c) is linked to the ring directly or through an oxygen atom at the right end) or an alkyl group having 5 to 12 carbon atoms. preferable.
As C ⁴¹ and C ⁵¹ , a 1,4-cyclohexylene group is preferable.
Z ⁴¹ and Z ⁵¹ are preferably a single bond.
X ⁴¹ and X ⁵¹ are preferably a fluorine atom or a trifluoromethoxy group, and more preferably a fluorine atom.
Specifically, compounds represented by general formula (VII-1) to general formula (VII-42) are preferable.

(Wherein R ⁴² and R ⁵² represent an alkyl group having 1 to 18 carbon atoms.)
Further, in order to obtain further expansion of the liquid crystal temperature region, high dielectric constant, or low viscosity, the general formula (Va), the general formula (VI-a), the general formula (VI-b), and the general formula (VII- In addition to the compound of a) and general formula (VII-b), it is also preferable to contain the compound represented by general formula (VIII-a), general formula (IX-a), or general formula (X).
<Compound represented by formula (VIII-a)>
When the specific example of the low molecular liquid crystal compound (II) used for the polymer stabilization liquid crystal composition of this invention is shown, (II) is the following general formula (VIII-a).

（式（ＶＩＩＩ−ａ）中、Ｒ^６１及びＲ^６２はそれぞれ独立して、炭素原子数１から１８のアルキル基又は炭素原子数２から１８のアルケニル基（該アルキル基又はアルケニル基中に存在する１個又は２個以上のメチレン基は、酸素原子が相互に直接結合しないものとして、酸素原子で置換されていてもよい。）を表し、
Ｃ^６１、Ｃ^６２及びＣ^６３はそれぞれ独立して１，４−フェニレン基又は１，４−シクロヘキシレン基（該１，４−フェニレン基は非置換であるか又は置換基として１個又は２個以上のフッ素原子、塩素原子、メチル基又はトリフルオロメチル基又はトリフルオロメトキシ基を有することができる。）を表し、

(In the formula (VIII-a), R ⁶¹ and R ⁶² are each independently an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms (present in the alkyl group or alkenyl group). One or more methylene groups may be substituted with oxygen atoms, assuming that the oxygen atoms are not directly bonded to each other),
C ⁶¹ , C ⁶² and C ⁶³ are each independently a 1,4-phenylene group or a 1,4-cyclohexylene group (the 1,4-phenylene group is unsubstituted or has one or two substituents) It can have the above fluorine atom, chlorine atom, methyl group, trifluoromethyl group or trifluoromethoxy group).

Z ⁶¹ and Z ⁶² each independently represent a single bond, —CH ₂ O—, —OCH ₂ — or —CH ₂ CH ₂ —,
n ⁶¹ represents 0, 1 or 2. However, when n ⁶¹ is 2, a plurality of C ⁶¹ and Z ⁶² may be the same or different.

In General Formula (VIII-a), R ⁶¹ and R ⁶² are each an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms (one or 2 present in the alkyl group or alkenyl group). The methylene group or more is preferably an alkenyl group or an alkenyloxy group represented by the formula (VI-c) (provided that the oxygen atom may not be directly bonded to each other and may be substituted with an oxygen atom). More preferably, the alkenyl group is represented by the formula (VI-c)) or an alkyl group or alkoxy group having 1 to 5 carbon atoms.
In particular, when it is desired to obtain a low viscosity, it is preferable that n ⁶¹ is 0, C ⁶² and C ⁶³ are 1,4-cyclohexylene groups, and Z ⁶² is a single bond.

In particular, to expand the liquid crystal temperature range, n ⁶¹ is 0 or 1, C ⁶¹ and C ⁶² are 1,4-cyclohexylene groups, and C ⁶³ is a 1,4-phenylene group (the 1, The 4-phenylene group is unsubstituted or may have one or more fluorine atoms or methyl groups as substituents.), And Z ⁶¹ is a single bond or —CH ₂ CH ₂ —. Z ⁶² is preferably a single bond.
In order to obtain a particularly high refractive index, n ⁶¹ is 1, and C ⁶¹ is a 1,4-cyclohexylene group or a 1,4-phenylene group (the 1,4-phenylene group is unsubstituted or 1 or 2 or more fluorine atoms and methyl groups can be substituted.) C ⁶² and C ⁶³ are 1,4-phenylene groups (the 1,4-phenylene groups are unsubstituted). Or it may have one or more fluorine atoms or methyl groups as substituents.).
Specifically, compounds represented by general formula (VIII-1) to general formula (VIII-5) are preferable.

(In the formula, R ⁶⁵ and R ⁶⁶ are each independently an alkyl group having 1 to 18 carbon atoms (one or two or more methylene groups present in the alkyl group have oxygen atoms not directly bonded to each other). And may be substituted with an oxygen atom.), And X ⁶¹ to X ⁶⁶ each independently represents a hydrogen atom, a fluorine atom or a methyl group.)
Further, specific examples of general formula (VIII-a) are preferably general formulas (VIII-6) to (VIII-15).

(In the formula, R ⁶⁷ and R ⁶⁸ are each independently an alkyl group having 1 to 18 carbon atoms (one or two or more methylene groups present in the alkyl group have oxygen atoms not directly bonded to each other). And may be substituted with an oxygen atom.), An alkoxy group, an alkenyl group having 2 to 18 carbon atoms and an alkenyloxy group, wherein X and Y are each independently a hydrogen atom, a fluorine atom or a methyl group. Z ⁶³ represents each independently a single bond or —O—, and Z ⁶⁴ and Z ⁶⁵ each independently represent a single bond, —CH ₂ O—, —OCH ₂ — or —CH ₂ CH. _2- represents.

<Compound represented by formula (IX-a)>
When the specific example of the low molecular liquid crystal compound (II) used for the polymer stabilization liquid crystal composition of this invention is shown, (II) is the following general formula (IX-a).

（式（ＩＸ−ａ）中、Ｒ^７１は炭素原子数１から１８のアルキル基又は炭素原子数２から１８のアルケニル基（該アルキル基又はアルケニル基中に存在する１個又は２個以上のメチレン基は、酸素原子が相互に直接結合しないものとして、酸素原子で置換されていてもよい。）を表し、

(In the formula (IX-a), R ⁷¹ represents an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms (one or two or more methylenes present in the alkyl group or alkenyl group). The group may be substituted with an oxygen atom, assuming that the oxygen atoms are not directly bonded to each other),

C ⁷¹ , C ⁷² and C ⁷³ are each independently 1,4-phenylene group, 1,4-cyclohexylene group or indan-2,5-diyl group (the 1,4-phenylene group and indan-2,5 The -diyl group can be unsubstituted or have one or more fluorine, chlorine, methyl, trifluoromethyl or trifluoromethoxy groups as substituents).
Z ⁷¹ and Z ⁷² each independently represent a single bond, —CH ₂ CH ₂ — or —CH ₂ O—,
^X71 represents a fluorine atom, a chlorine atom, a trifluoromethyl group or a trifluoromethoxy group, a difluoromethyl group, an isocyanate group,
n ⁷¹ represents 0, 1 or 2. However, when n ⁷¹ is 2, a plurality of C ⁷¹ and Z ⁷¹ may be the same or different. )

R ^{71 in the} general formula (IX-a) is an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 6 carbon atoms (one or two or more present in the alkyl group or alkenyl group). The methylene group may preferably be substituted with an oxygen atom assuming that oxygen atoms are not directly bonded to each other.) The alkenyl group is preferably represented by the formula (Vc), and has Even more preferred are alkyl groups of 1 to 18 or alkoxy groups of 1 to 18 carbon atoms.

X ⁷¹ is preferably a fluorine atom or a trifluoromethoxy group, and more preferably a fluorine atom.
In particular, when it is desired to obtain a high dielectric constant, n ⁷¹ is 0 or 1, C ⁷¹ is a 1,4-cyclohexylene group, and C ⁷² is a 1,4-cyclohexylene group or 1,4. -Phenylene group (the 1,4-phenylene group is unsubstituted or may have one or more fluorine atoms or methyl groups as substituents), and C ⁷³ is 2-fluoro- A 1,4-phenylene group, a 3-fluoro-1,4-phenylene group, a 2,6-difluoro-1,4-phenylene group or a 3,5-difluoro-1,4-phenylene group, and Z ⁷¹ and Z ⁷² is preferably a single bond.

In particular, to expand the liquid crystal temperature range, n ⁷¹ is 2, C ⁷¹ is a 1,4-cyclohexylene group, and C ⁷² is a 1,4-cyclohexylene group or a 1,4-phenylene group. And ^C73 is 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 2,6-difluoro-1,4-phenylene group or 3,5-difluoro-1,4 - phenylene ^{group, Z 71} and ^{Z 72} is a single bond or _-CH 2 CH ₂ - is preferably.
Specifically, compounds represented by general formula (IX-1) to general formula (IX-4) are preferable.

(Wherein R ⁷² represents an alkyl group or alkoxy group having 1 to 18 carbon atoms, X ⁷² to X ⁷⁵ each independently represents a hydrogen atom or a fluorine atom, and Z ⁷³ represents a single bond or —CH ₂ CH _2. Represents-)
Among these general formulas (IX-1) to (IX-4), compounds represented by general formulas (IX-5) to (IX-7) are more preferable.

(In the formula, R ⁷⁷ represents an alkyl group having 1 to 18 carbon atoms, and X ⁷⁷ to X ⁷⁹ each independently represents a hydrogen atom or a fluorine atom.)
<Compound represented by formula (X)>
Specific examples of the low-molecular liquid crystal compound (II) used in the polymer-stabilized liquid crystal composition of the present invention are shown in the following general formula (X).

(In formula (X), R ¹⁰¹ and R ¹⁰² each independently represents a linear or branched alkyl group having 1 to 18 carbon atoms, provided that one or two non-adjacent —CH ₂ — The group is —O—, —S—, —CO—, —CO—O—, —O—CO—, —CO—S—, —S—CO—, —O—CO—O—, —CH═CH. -, -C≡C-, a cyclopropylene group, or -Si (CH ₃ ) _2- may be substituted, and one or more hydrogen atoms of the alkyl group may be replaced by a fluorine atom or a CN group. A ¹⁰¹ represents a 1,4-phenylene group, and B ¹⁰¹ and C ¹⁰¹ each independently represent one or two hydrogen atoms as a fluorine atom, a CF 3 group, an OCF 3 group, a CN group, or a plurality of these 1,4-phenylene group which may be replaced by a group, or , 1,4 ^{cyclohexylene,} a 1, ^{b 1,} and ^{c 1} is an integer of 0 or ^{1, (a 1 + b 1 + c} 1) = 1 or 2.)
The compounds represented by the general formula (X) are specifically represented by the general formulas (Xa) to (Xf).

(In the general formulas (Xa) to (Xf), Y ¹⁰¹ and X ⁴ are each independently an alkyl group having 1 to 18 carbon atoms, an alkoxy group, or an alkenyl group having 2 to 18 carbon atoms. (one, or two or more methylene groups present in the alkyl or alkenyl group, as the oxygen atoms are not directly bonded to each other, an oxygen atom may be substituted.) represent, Z ¹⁰¹ is , An alkyl group having 1 to 18 carbon atoms, an alkoxy group, or an alkenyl group having 2 to 18 carbon atoms (one or two or more methylene groups present in the alkyl group or alkenyl group have an oxygen atom May be substituted with an oxygen atom as not directly bonded to each other), or independently a fluorine atom, a chlorine atom, a trifluoromethyl group or a trifluoromethoxy group, difluoromethyl It represents group, an isocyanate group,
X ⁸¹ to X ⁹⁶ each independently represents a hydrogen atom, a fluorine atom, or a methyl group.
Specific examples of the compounds represented by the general formula (Xa) to the general formula (Xf) include the following (X-1)
To (X-17).

＜一般式（ＸＩ）で表される化合物＞
本発明の高分子安定化液晶組成物に用いられる低分子液晶化合物（ＩＩ）の具体例を示すと（ＩＩ）は、下記一般式（ＸＩ）

<Compound represented by formula (XI)>
Specific examples of the low-molecular liquid crystal compound (II) used in the polymer-stabilized liquid crystal composition of the present invention are shown in the following general formula (XI).

(In formulas (XI-a) to (XI-f), R ²⁰¹ and R ²⁰² each independently represents an alkyl group having 1 to 18 carbon atoms, an alkoxyl group, or an alkenyl group having 2 to 18 carbon atoms (the alkyl group). Or one or two or more methylene groups present in the alkenyl group may be substituted with an oxygen atom so that the oxygen atoms are not directly bonded to each other) or an alkenyloxy group,
Z ²⁰¹ represents a single bond, —CH ₂ CH ₂ , —OCH ₂ — or —CH ₂ O—,

X ²⁰¹ , Y ²⁰¹ and W ^{201 each} represents a fluorine atom, a chlorine atom, a trifluoromethyl group or a trifluoromethoxy group, and a difluoromethyl group, and V in the general formulas (XI-e) and (XI-f) , -CH2- or -O-.
In General Formula (XI-a) and General Formula (XI-f), R ²⁰¹ and R ²⁰² are each an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 6 carbon atoms (the alkyl group or alkenyl group). 1 or 2 or more methylene groups present therein may preferably be substituted with oxygen atoms so that the oxygen atoms are not directly bonded to each other.
The alkyl group or alkenyl group has the formula (XI-g)

（式（ＶＩＩ−ｃ）中の構造式は右端で直接もしくは酸素原子を介して環に連結しているものとする。）で表されるアルケニル基又は炭素原子数５から１２のアルキル基がより好ましい。
＜一般式（ＸＩＩ）で表される化合物＞
本発明の高分子安定化液晶組成物に用いられる低分子液晶化合物（ＩＩ）の具体例を示すと（ＩＩ）は、下記一般式（ＸＩＩ）

(The structural formula in the formula (VII-c) is linked to the ring directly or through an oxygen atom at the right end) or an alkyl group having 5 to 12 carbon atoms. preferable.
<Compound represented by formula (XII)>
Specific examples of the low-molecular liquid crystal compound (II) used in the polymer-stabilized liquid crystal composition of the present invention are shown in the following general formula (XII).

(In formulas (XII-a) to (XII-c), R ³⁰¹ and R ³⁰² each independently represents an alkyl group having 1 to 18 carbon atoms, an alkoxyl group, or an alkenyl group having 2 to 18 carbon atoms (the alkyl group). Or one or two or more methylene groups present in the alkenyl group may be substituted with an oxygen atom so that the oxygen atoms are not directly bonded to each other) or an alkenyloxy group,
In General Formula (XII-a) and General Formula (XII-c), R ³⁰¹ and R ³⁰² are each an alkyl group having 1 to 18 carbon atoms or an alkenyl group having 2 to 6 carbon atoms (the alkyl group or alkenyl group). 1 or 2 or more methylene groups present therein may preferably be substituted with an oxygen atom so that the oxygen atoms are not directly bonded to each other), and the alkyl group or alkenyl group may be represented by the formula ( XII-d)

（式（ＶＩＩ−ｃ）中の構造式は右端で直接もしくは酸素原子を介して環に連結しているものとする。）で表されるアルケニル基又は炭素原子数５から１２のアルキル基がより好ましい。

(The structural formula in the formula (VII-c) is linked to the ring directly or through an oxygen atom at the right end) or an alkyl group having 5 to 12 carbon atoms. preferable.

<Composition ratio of polymer stabilized liquid crystal composition>
The polymer-stabilized liquid crystal composition of the present invention comprises a non-polymerizable low-molecular liquid crystal compound represented by compound (II), a chiral compound (IV), a polymerizable compound (I), and a polymerizable compound (III). It is comprised with the polymeric liquid crystal compound represented. The total composition ratio of the non-polymerizable low-molecular liquid crystal compound and the chiral compound and the composition ratio of the polymerizable compound are such that if the composition ratio of the polymerizable compound is too large, the characteristics as the polymer-stabilized liquid crystal composition are impaired. Exists. Specifically, the total of the non-polymerizable low-molecular liquid crystal compound and the chiral compound is preferably 92% to 99.9%, more preferably 92% to 99%, and 94% to 98% contained. It is particularly preferred.

  The polymer-stabilized liquid crystal composition of the present invention has a general formula (VI-a) or a general formula (VI-b) as a low molecular liquid crystal compound represented by the general formula (II-a) or (II-b). , A liquid crystal composition comprising at least one compound represented by formula (VII-a), formula (VII-b), formula (VIII-a), formula (IX-a), or formula (X) 92 to 99.9% by mass of the product, 0.1 to 8% of the polymerizable composition containing the compounds represented by the general formulas (Ia) and (III-a) Preferably, the liquid crystal composition is contained in 92% to 99%, the polymerizable composition is contained in 1 to 8% by mass, the liquid crystal composition is contained in 94% to 98%, and the polymerizable composition is contained. It is particularly preferable to contain 2 to 6% by mass of the product.

  As the liquid crystal composition, the content of the compound represented by the general formula (X) is 5 to 90%, represented by the general formula (Xa), the general formula (Xb), and the general formula (Xc). A compound having a content of 50 to 99% is preferred. A compound group represented by general formula (VI-a), general formula (VI-b) and general formula (VII-a), general formula (VII-b), and general formula (VIII-a), general formula ( The compound group represented by IX-a) is preferably used for obtaining the basic physical properties of the target liquid crystal composition. The basic physical properties include refractive index anisotropy, dielectric anisotropy, elastic constant, liquid crystal phase sequence, liquid crystal phase temperature range, spontaneous polarization, etc. It is preferable to select and use. In particular, the compound group represented by (XI-a) to (XI-f) and the compound group represented by (XII-a) to (XII-c) are compounds for the purpose of adjusting negative dielectric anisotropy. It is preferable to select and use. In the polymer-stabilized liquid crystal composition of the present invention, the content of the polymerizable compound (III) is 0.05% to 7%, and the polymerizable compound (III) and the polymerizable compound (I) The composition ratio is preferably (III) :( I) = 1: 1 to 49: 1.

In the present invention, a polyfunctional liquid crystalline monomer may be added in addition to the polymerizable liquid crystal compound (III). As this polyfunctional liquid crystalline monomer, acryloyloxy group, methacryloyloxy group, acrylamide group, methacrylamide group, epoxy group, vinyl group, vinyloxy group, ethynyl group, mercapto group, maleimide group, ClCH = _{CHCONH-, CH 2 = CCl-, CHCl} = CH-, RCH = CHCOO- ( wherein R is chlorine, fluorine, or a hydrocarbon group having 1 to 18 carbon atoms), but can be exemplified acryloyl among these An oxy group, a methacryloyloxy group, an epoxy group, a mercapto group, and a vinyloxy group are preferable, a methacryloyloxy group or an acryloyloxy group is particularly preferable, and an acryloyloxy group is most preferable.

As the molecular structure of the polyfunctional liquid crystalline monomer, there are at least two liquid crystal skeletons having two or more ring structures, a polymerizable functional group, and a flexible group for connecting the liquid crystal skeleton and the polymerizable functional group. Those having three flexible groups are more preferable. Examples of the flexible group include an alkylene spacer group represented by — (CH ₂ ) _n — (where n represents an integer) or — (Si (CH ₃ ) ₂ —O) _n — (where n is Siloxane spacer groups represented by the formula (representing an integer), among which an alkylene spacer group is preferred. Bonds such as —O—, —COO—, and —CO— may be present in the bonding portion between these flexible groups and the liquid crystal skeleton or polymerizable functional group.

The liquid crystal skeleton can be used without particular limitation as long as it is generally recognized as a liquid crystal skeleton (mesogen) in this technical field, but those having at least two or more ring structures are preferable.
The ring that can be used as the ring structure is benzene, pyridine, pyrazine, pyridazine, pyrimidine, 1,2,4-triazine, 1,3,5-triazine, tetrazine, dihydrooxazine, cyclohexane, cyclohexene, cyclohexadiene, cyclohexanone, piperidine , Piperazine, tetrahydropyran, dioxane, tetrahydrothiopyran, dithiane, oxathiane, dioxaborinane, naphthalene, dioxanaphthalene, tetrahydronaphthalene, quinoline, coumarin, quinoxaline, decahydronaphthalene, indane, benzoxazole, benzothiazole, phenanthrene, dihydrophenance Len, perhydrophenanthrene, dioxaperhydrophenanthrene, fluorene, fluorenone, cycloheptane, cyclohexane Tatrienone, cholesterol, bicyclo [2.2.2] octane, bicyclo [2.2.2] octene, 1,5-dioxaspiro (5.5) undecane, 1,5-dithiaspiro (5.5) undecane, triphenylene, Examples include torquesen, porphyrin, and phthalocyanine. Among these, benzene, cyclohexane, phenanthrene, naphthalene, tetrahydronephthalene, and decahydronephthalene are preferable.

One or more of these rings may be substituted with an alkyl group having 1 to 7 carbon atoms, an alkoxy group, an alkanoyl group, a cyano group, or a halogen atom. As the alkyl group, a methyl group, an ethyl group, an n-propyl group, and an n-butyl group are desirable, and a methyl group and an ethyl group are particularly preferable. As an alkoxy group, a methoxy group, an ethoxy group, a propoxy group, and a butoxy group are preferable. As an alkanoyl group, an acetyl group, a propionyl group, and a butyroyl group are preferable. As a halogen atom, a fluorine atom, a bromine atom, and a chlorine atom are preferable. A fluorine atom and a chlorine atom are particularly preferable. In addition to the polyfunctional liquid crystalline monomer, a monofunctional liquid crystalline monomer may be added. In any case, the low molecular weight liquid crystal is low molecular weight so that the uniaxial orientation, tilt angle, driving voltage, and other electro-optical characteristics of the low molecular liquid crystal match the specifications of the applied product (operating temperature, driving voltage, contrast, transmittance, reliability, etc.). It is preferable to adjust the composition of the polymer precursor in the same manner as the liquid crystal composition.

These liquid crystal compositions may be subjected to a purification treatment with silica, alumina or the like for the purpose of removing impurities or the like or further increasing the specific resistance value. The specific resistance value is preferably 10 ¹² Ω · cm or more, and more preferably 10 ¹³ Ω · cm or more. Furthermore, dopants such as chiral compounds and dyes can be added to the liquid crystal composition according to the purpose.
In addition, antioxidants, UV absorbers, non-reactive oligomers and inorganic fillers, organic fillers, polymerization inhibitors, antifoaming agents, leveling agents, plasticizers, silane coupling agents, etc. are added as necessary. You may do it.

The polymer-stabilized liquid crystal composition of the present invention comprises a non-polymerizable low-molecular liquid crystal compound represented by compound (II), a chiral compound (IV), a polymerizable compound (I), and a polymerizable compound (III). Although comprised with the polymeric compound represented, when polymerizing a polymer stabilized liquid crystal composition, it is preferable to contain a polymerization initiator. When the polymerization initiator is contained, the content other than the polymerization initiator is preferably 98% to 99.9%, and the polymerization initiator is preferably 0.1% to 2%.
The optical element of the present invention can be produced by searching for the optimum conditions (frequency, applied voltage, temperature) for the liquid crystal composition used in the above-described way of thinking.

(Production and evaluation method of polymer-stabilized liquid crystal optical element)
The polymer-stabilized liquid crystal display element was produced by the following method.
The polymer-stabilized liquid crystal composition was injected by vacuum injection after heating to an isotropic phase-nematic phase transition temperature or higher (80 ° C.). Smectic A phase-Nematic C ^* Slow cooling at a rate of 1 ° C / min in the range of 73 ° C to 69 ° C near the phase transition temperature, and transition to the smectic A phase with the helical pitch of the nematic * phase unraveled. A defect-free uniaxial orientation was obtained. Furthermore, in order to suppress the occurrence of zigzag alignment defects, the film was gradually cooled from 69 ° C. to 65 ° C. at a rate of temperature decrease of 2 ° C./min, and transferred to the smectic C * phase. As the liquid crystal cell, an anti-parallel rubbing alignment cell with ITO coated with a polyimide alignment film having a cell gap of 3 μm or 5 μm was used. As the polyimide alignment film, RN-1199 manufactured by Nissan Chemical Co., Ltd. was used.

  A light control layer forming material comprising a liquid crystal composition, a radical polymerizable composition, a photopolymerization initiator, and a small amount of a polymerization inhibitor was injected into the glass cell by a vacuum injection method. The degree of vacuum was set to be 2 Pascals. After the injection, the glass cell was taken out and the inlet was sealed with a sealing agent 3026E (manufactured by ThreeBond). After confirming the biaxial orientation with a crossed Nichols polarizing microscope, ultraviolet rays were exposed while switching by applying a pulse wave (rectangular wave) having an electric field intensity of 3 V / μm at a frequency of 70 Hz or 2 kHz. It adjusted so that the irradiation intensity of the cell sample surface might be 5 mW / cm <2> at 25 degreeC. The lamp was irradiated for 600 seconds using an ultraviolet light emitting diode (emission center wavelength: 365 nm) to polymerize the polymerizable compound of the polymer stabilized liquid crystal composition to obtain a polymer component stabilized liquid crystal display device. After the ultraviolet exposure, the applied voltage was turned off, and the alignment state was observed with a polarizing microscope, and the state in which the uniaxial alignment stabilized by the polymer was maintained without an electric field was examined. Further, the electro-optical characteristics were measured by applying a rectangular wave of 60 Hz after adjusting the uniaxial alignment direction of the liquid crystal cell and the polarization direction of the analyzer in the crossed Nicols of the polarizing microscope to make the dark field. The transmittance was 0% when the two polarizing plates were orthogonal, and 100% when they were parallel.

(Adjustment of polymer stabilized liquid crystal composition)
1 to the ferroelectric liquid crystal composition (FLC-1) containing the chiral liquid crystal compound of compound group (X) and compound group (IV) so that the cholesteric helix can be dissolved in the nematic ^* phase of the liquid crystal composition. The chiral compound (IV-1) of the compound group (VI-i) was added and dissolved by heating in an isotropic phase. Further, a photopolymerizable acrylate composition containing at least one compound group (I) and (III) was blended and dissolved by heating to prepare a polymer stabilized liquid crystal composition (PSV-1).

The phase sequence of the ferroelectric liquid crystal is isotropic phase 76 ° C nematic ^* phase 71 ° C smectic A phase 67 ° C smectic C * phase <-20 ° C crystal. The structure and composition of each component are shown below.
Further, the ferroelectric liquid crystal composition (FLC-2) of FIG. 3 containing the chiral liquid crystal compounds of the compound group (X) and the compound group (IV) is prepared, and the spiral in the smectic C * phase of the liquid crystal composition is prepared. Is added to the compound group (VI-j) chiral compound (VI-2) so as to exist in a 5 μm cell, and a photopolymerizable acrylate composition containing at least one compound group (I) and (III) is blended. Thus, a polymer stabilized liquid crystal composition (PSV-2) was prepared. The chiral compound is described in J. Org. Mater. Chem. , 1994, 4 (3), p449-456.
A composition (FLC-1) containing compound group (X) and compound group (IV) is shown below.

化合物郡（ＩＶ−ｉ）のキラル化合物を次に示す。

The chiral compounds in Compound Group (IV-i) are shown below.

化合物郡（Ｘ）と化合物郡（ＩＶ）を含有する組成物（ＦＬＣ−２）を次に示す。

A composition (FLC-2) containing compound group (X) and compound group (IV) is shown below.

（ＦＬＣ−２）に添加する化合物郡（ＩＶ−ｉ）のキラル化合物を次に示す。

The chiral compound of the compound group (IV-i) to be added to (FLC-2) is shown below.

化合物郡（I） に属する光重合性アクリレート（Ｉ−ＡＭ１）の構造を以下に示す。

The structure of the photopolymerizable acrylate (I-AM1) belonging to the compound group (I) is shown below.

化合物郡（ＩＩＩ）に属する重合性液晶アクリレートの構造を次に示す。

The structure of the polymerizable liquid crystal acrylate belonging to the compound group (III) is shown below.

Example 1
The ferroelectric liquid crystal composition (FLC-1) is 97%, (IV-1) is 1%, the mixing ratio of (III-UC1) and (III-UC2) is 1: 1 to 0.196%, (I -A polymer stabilized liquid crystal composition was prepared by blending AM1) at a ratio of 1.764% and Irgacure 651 (Irg651) at a ratio of 0.04%. The helical pitch of the smectic C * phase in the prepared composition was 0.9 μm at 0 ° C., 1.8 μm at 25 ° C., and 2.3 μm at 50 ° C.

In the above-described method for producing a polymer-stabilized optical liquid crystal element, a liquid crystal composition prepared in a liquid crystal cell having a cell thickness of 3 μm is injected in an isotropic phase of 80 ° C., and slowly cooled at 2 ° C./min. Waiting for the cholesteric helical pitch of the nematic ^* phase to be dissolved at 5 ° C, and when dark field was obtained by uniaxial orientation under crossed Nicols, slow cooling was resumed to transfer to the smectic A phase. It was confirmed that there was a dark field (uniaxial orientation) in the rubbing direction in the phase and that there were no orientation defects. Further cooling was continued, transitioning to a smectic C * phase at 67 ° C., and observation of the orientation state of the smectic C * phase at a temperature of 25 ° C. with a polarizing microscope revealed a biaxial orientation without a helical structure. When rotating the crossed Nicols and aligning the analyzer with one of the biaxially oriented orientation axes and observing the orientation state, the dark field portion was slightly colored with a birefringent color and was in a twisted orientation state. When cooled to 0 ° C., a stripe pattern representing a spiral structure was observed. Such an alignment state described above showed the characteristics of the ferroelectric liquid crystal. A liquid crystal optical element is produced by polymerizing the acrylate compound in the polymer-stabilized liquid crystal composition by exposing it to ultraviolet light while applying a rectangular wave of 15 Vo-p at a frequency of 2 kHz in a smectic C * phase at 25 ° C. did. When the alignment after polymerization was observed with a polarizing microscope, the voltage was turned off after exposure, and the sample stage of the microscope was rotated with a polarizing microscope to observe the alignment state. The entire electrode portion disappeared from the biaxial orientation characteristic of the smectic C * phase observed before the ultraviolet exposure, and showed a quenching position in the rubbing orientation treatment direction and was uniaxially oriented. Since no rectangular wave was applied around the electrode, a biaxial orientation of the smectic C * phase was observed. The produced cell was cooled to −10 ° C., and it was confirmed with a polarizing microscope that the smectic C * phase did not show a stripe pattern derived from the helical pitch and was monodomain switched.
The wavelength dispersion of the cell produced by the microspectroscope was measured, and Δn of the cell was obtained from curve fitting using the following equation.

（Ｉ：出射光強度、Ｉo：入射光強度、ｄ：セル厚、Δｎ：複屈折率、λ：波長、θ：検光子の偏光方向を基点に一軸配向方向が傾斜した角度）電圧０Ｖの一軸配向のΔｎは、０．１８９、電圧９Ｖｏ−ｐは０．１６８であった。
前記消光の位置（暗視野）にて電圧を０Vとから徐々に上げて印加すると暗視野から明視野へ電極部分全体が一様に変化して透過率が連続的に増加する。このことは連続階調表示が可能であることを意味する。６０Hzの矩形波を印加して電圧―透過率特性を測定した所、図１のV字型電圧―透過率特性を示し、応答は、立ち上がり時間が１９０μｓ、立ち下り時間が250μｓ、駆動電圧V90は６．９V（V90の電界強度：２．３V/μｍ）、傾斜角（チルト角）が２５度、最小透過率Ｔｏは０．０９％、最大透過率は４０．２％、コントラストが１：３１５の特性が得られた。

(I: outgoing light intensity, Io: incident light intensity, d: cell thickness, Δn: birefringence, λ: wavelength, θ: angle in which the uniaxial orientation direction tilts from the polarization direction of the analyzer) Uniaxial voltage 0V The orientation Δn was 0.189, and the voltage 9Vo-p was 0.168.
When the voltage is gradually increased from 0 V and applied at the extinction position (dark field), the entire electrode portion changes uniformly from the dark field to the bright field, and the transmittance continuously increases. This means that continuous tone display is possible. When the voltage-transmittance characteristics were measured by applying a 60 Hz rectangular wave, the V-shaped voltage-transmittance characteristics shown in FIG. 1 were shown. The response was a rise time of 190 μs, a fall time of 250 μs, and a drive voltage V90 of 6.9V (V90 electric field strength: 2.3V / μm), tilt angle (tilt angle) is 25 degrees, minimum transmittance To is 0.09%, maximum transmittance is 40.2%, contrast is 1: 315 The characteristics were obtained.

(Comparative Example 1)
A liquid crystal optical element was produced by polymerizing the acrylate compound in the polymer-stabilized liquid crystal composition in the same manner as in Example 1 except that UV exposure was performed without applying voltage. After exposure, the sample state of the microscope was rotated with a polarizing microscope, and the alignment state was observed. The biaxial orientation characteristic of the smectic C * phase was exhibited, and the two domains in the bi-directional orientation state were stabilized. The desired uniaxial orientation and V-shaped voltage-transmittance characteristics were not obtained.

(Example 2)
A liquid crystal optical element was produced by polymerizing the acrylate compound in the polymer-stabilized liquid crystal composition in the same manner as in Example 1 except that the cell thickness was 2.5 μm. After exposure, the sample state of the microscope was rotated with a polarizing microscope, and the alignment state was observed. When the voltage after exposure was cut, the entire electrode part disappeared from the biaxial orientation that was characteristic of the smectic C * phase seen before UV exposure, and was extinction in the rubbing orientation treatment direction and was uniaxially oriented. . Since no rectangular wave was applied around the electrode, a biaxial orientation of the smectic C * phase was observed.
The wavelength dispersion of the cell produced by the microspectroscope was measured, and Δn of the cell was similarly obtained from curve fitting using the formula described in Example 1. The uniaxial orientation Δn of voltage 0V was 0.183, and the voltage 9Vo-p was 0.169.

  When the voltage is gradually increased from 0 V and applied at the extinction position (dark field), the entire electrode portion changes uniformly from the dark field to the bright field, and the transmittance continuously increases. This means that continuous tone display is possible. When voltage-transmittance characteristics were measured by applying a 60 Hz rectangular wave, V-shaped voltage-transmittance characteristics were shown, drive voltage V90 was 6.3 V (V90 electric field strength: 2.5 V / μm), slope The angle (tilt angle) was 24.9 degrees, the minimum transmittance To was 0.47%, the maximum transmittance was 50.1%, and the contrast was 1: 106.

(Example 3)
A liquid crystal optical element was produced by polymerizing the acrylate compound in the polymer-stabilized liquid crystal composition in the same manner as in Example 1 except that the cell thickness was 2.0 μm. After exposure, the sample state of the microscope was rotated with a polarizing microscope, and the alignment state was observed. When the voltage after exposure was cut, the entire electrode part disappeared from the biaxial orientation that was characteristic of the smectic C * phase seen before UV exposure, and was extinction in the rubbing orientation treatment direction and was uniaxially oriented. . Since no rectangular wave was applied around the electrode, a biaxial orientation of the smectic C * phase was observed.
When the voltage is gradually increased from 0 V and applied at the extinction position (dark field), the entire electrode portion changes uniformly from the dark field to the bright field, and the transmittance continuously increases. This means that continuous tone display is possible. When voltage-transmittance characteristics were measured by applying a 60Hz rectangular wave, V-shaped voltage-transmittance characteristics were shown, drive voltage V90 was 5.9V (V90 electric field strength: 3V / μm), minimum transmittance A characteristic of To of 0.49%, maximum transmittance of 50.3%, and contrast of 1: 102 was obtained.

Example 4
A liquid crystal optical element was produced by polymerizing the acrylate compound in the polymer-stabilized liquid crystal composition in the same manner as in Example 1 except that the cell thickness was 1.8 μm. After exposure, the sample state of the microscope was rotated with a polarizing microscope, and the alignment state was observed. When the voltage after exposure was cut, the entire electrode part disappeared from the biaxial orientation that was characteristic of the smectic C * phase seen before UV exposure, and was extinction in the rubbing orientation treatment direction and was uniaxially oriented. . Since no rectangular wave was applied around the electrode, a biaxial orientation of the smectic C * phase was observed.
When the voltage is gradually increased from 0 V and applied at the extinction position (dark field), the entire electrode portion changes uniformly from the dark field to the bright field, and the transmittance continuously increases. This means that continuous tone display is possible. When voltage-transmittance characteristics were measured by applying a 60 Hz rectangular wave, V-shaped voltage-transmittance characteristics were shown, drive voltage V90 was 6.4 V (V90 electric field strength: 3.5 V / μm), minimum The transmittance To was 0.31%, the maximum transmittance was 46.9%, and the contrast was 1: 150.

(Example 5)
92.15% of the liquid crystal composition (FLC-2) and 4.85% of the chiral compound (IV-2). A mixing ratio of (III-UC1) and (III-UC2) is 1: 1, 2.94%, and Irgacure 651 (Irg651) is blended at a ratio of 0.06% to prepare a polymer stabilized liquid crystal composition. A smectic C ^* phase stripe pattern was observed at a cell thickness of 5 μm, indicating a helical structure. In the preparation method of polymer-stabilized optical liquid crystal elements, the prepared liquid crystal composition was injected into a liquid crystal cell having a cell thickness of 5 μm, and slowly cooled and confirmed to be uniaxially aligned in the smectic A phase with a polarizing microscope. did. When the orientation state of the smectic C * phase is observed in the temperature range from the smectic C * phase transition temperature of 67 ° C to 25 ° C, it is observed that the helical pitch interval represented by the striped pattern is reduced. It showed 1.3 μm. A rectangular wave with an electric field intensity of 8 V / μm and 70 Hz, which is a condition for unraveling the spiral, was applied to disappear the spiral, and in this state, ultraviolet rays were exposed in the same manner as in Example 1 except for the voltage condition. After exposure, the sample state of the microscope was rotated with a polarizing microscope, and the alignment state was observed. When no voltage was applied, the electrode portion exhibited a quenching position substantially in the rubbing alignment treatment direction and was uniaxially aligned. When the voltage is gradually increased from 0 V and applied at the extinction position, the entire electrode portion changes uniformly from the dark field to the bright field, and the transmittance is continuously increased to enable continuous gradation display. It was confirmed. When the voltage-transmittance characteristics were measured by applying a 60 Hz rectangular wave, the V-shaped voltage-transmittance characteristics shown in FIG. 2 were shown. The drive voltage V90 was 19 V (V90 electric field strength: 3.8 V / μm). The minimum transmittance To was 1.82%, the maximum transmittance was 8.9%, and the contrast was 1:23. Ferroelectric liquid crystals are applied to displays by obtaining a biaxial orientation by thinning the cell thickness and solving the spiral to solve the helical structure. However, when the cell thickness is 5 μm, the ferroelectric liquid crystal is often helical and has a uniaxial orientation. Although it was difficult to obtain, uniaxial orientation could be obtained by stabilizing the orientation of the liquid crystal with a polymer under the voltage condition of unwinding the spiral. The low transmittance was strongly affected by the retardation (Δnd) of the cell and became low. This can be solved by adjusting retardation by reducing Δn of the liquid crystal.

(Comparative Example 1)
A liquid crystal optical element was produced by polymerizing the acrylate compound in the polymer-stabilized liquid crystal composition in the same manner as in Example 1 except that UV exposure was performed without applying voltage. After exposure, the sample state of the microscope was rotated with a polarizing microscope, and the alignment state was observed. The biaxial orientation characteristic of the smectic C * phase was exhibited, and the two domains in the bi-directional orientation state were stabilized. The desired uniaxial orientation and V-shaped voltage-transmittance characteristics were not obtained.

(Comparative Example 2)
A liquid crystal optical element was produced by polymerizing the acrylate compound in the polymer-stabilized liquid crystal composition in the same manner as in Example 5 except that UV exposure was performed without applying voltage. After exposure, the sample state of the microscope was rotated with a polarizing microscope, and the alignment state was observed. The polymer was stabilized in a striped pattern having a spiral structure of 1.3 μm and light scattering occurred. The desired uniaxial orientation and V-shaped voltage-transmittance characteristics were not obtained.

(Comparative Example 3)
97% of a liquid crystal composition obtained by adding 5% of a chiral compound (IV-2) to a liquid crystal composition (FLC-2) prepared so as to be spirally wound in a smectic C ^* phase at a cell thickness of 5 μm, (III-UC1 ) And (III-UC2) are mixed at a ratio of 1: 1 of 2.94% and Irgacure 651 (Irg651) at a ratio of 0.06% to prepare a polymer stabilized liquid crystal composition. The orientation state was observed by rotating the sample stage of the microscope with a polarizing microscope. In the above-described method for producing a polymer-stabilized optical liquid crystal device, the prepared liquid crystal composition is injected into a liquid crystal cell having a cell thickness of 5 μm, slowly cooled, and uniaxially oriented in the smectic A phase. Confirmed with. When the orientation state of the smectic C * phase is observed at 25 ° C from the smectic C * phase transition temperature of 67 ° C, a striped pattern indicating a helical pitch is observed, and the interval decreases with decreasing temperature, and the helical pitch becomes 1. 3 μm was indicated. A rectangular wave of 2 kHz with an electric field strength of 8 V / μm was applied thereto, and a striped pattern showing a helical pitch was seen, and the spiral could not be completely unwound. In this state, ultraviolet rays were exposed under the above conditions. After exposure, the sample state of the microscope was rotated with a polarizing microscope, and the alignment state was observed. A striped pattern having a spiral structure was observed at the electrode portion, and uniaxial orientation was not obtained.

(Comparative Example 4)
The ferroelectric liquid crystal composition (FLC-1) was injected in an isotropic phase of 80 ° C., slowly cooled at 2 ° C./min, and after waiting for the cholesteric helical pitch of the nematic ^* phase to be dissolved at 71 ° C., 2 It was confirmed that a dark field in the rubbing direction was obtained in the smectic A phase by gradually cooling at 0 ° C./min. When the orientation state of the smectic C * phase was observed at 25 ° C. from the smectic C * phase transition temperature of 67 ° C., it was a biaxial orientation peculiar to the surface-stabilized ferroelectric liquid crystal (SSFLC) having no helical structure. When the temperature was set to −5 ° C., when the orientation state of the smectic C * phase was observed, a striped pattern indicating a helical pitch was observed, and a spiral structure peculiar to the smectic C * phase was developed. Since the polymer was not stabilized, the helical structure was expressed due to a change in physical properties where the helical pitch was reduced at low temperatures.

(Comparative Example 5)
The ferroelectric liquid crystal composition (FLC-1) is 97%, (IV-1) is 1%, the mixing ratio of (III-UC1) and (III-UC2) is 1: 1, 2.646%, (I -A polymer stabilized liquid crystal composition was prepared by blending AM1) at a ratio of 0.294% and Irgacure 651 (Irg651) at a ratio of 0.06%. In the above-described method for producing a polymer-stabilized optical liquid crystal device, the prepared liquid crystal composition is injected into a liquid crystal cell having a cell thickness of 1.4 μm, and is slowly cooled to be uniaxially oriented in the smectic A phase. Confirmed with a microscope. When the orientation state of the smectic C * phase was observed at 25 ° C. from the smectic C * phase transition temperature of 67 ° C., biaxial orientation was observed. A rectangular wave of 2 kHz with an electric field strength of 3.5 V / μm was applied thereto and exposed to ultraviolet rays. When the voltage was turned off and observed with a polarizing microscope, the entire electrode portion showed uniaxial orientation. When voltage-transmittance characteristics were measured by applying a 60 Hz rectangular wave, V-shaped voltage-transmittance characteristics were shown, drive voltage V90 was 5.7 V, minimum transmittance To was 0.35%, maximum transmittance The characteristics of 37.1% and contrast of 1: 107 were obtained. However, the transmittance is low, and the electric field intensity of V90 is 4.1 V / μm, which is higher than that of Example 1-5.

  The list of the above Examples and Comparative Examples shows the composition of Table 1, the production conditions of Table 2, and the V-shaped voltage-transmittance characteristics. The cell thickness and the maximum transmittance T100 in Example 1-5 and Comparative Example 1 are large in the range of 1.8 μm to 3 μm, and the maximum transmittance is small if it is out of this range. There are two reasons why the maximum transmittance is small. For one, as the cell thickness increases, the maximum transmission decreases due to the retardation effect associated with the formula described in Example 1. Second, when the cell thickness is reduced, the maximum transmittance is lowered because the proportion of liquid crystal that is strongly influenced by the alignment regulating force from the cell substrate interface and does not move even at high electric field strength increases. This is one proof that the electric field strength of V90 increases as the cell thickness decreases, as shown in Table 2, when compared with the electric field strength of V90 and the cell thickness. That is, according to the present invention, the maximum transmittance can be obtained by stabilizing the ferroelectric liquid crystal in a region where the alignment regulating force from the substrate interface is weakened under the condition of the helical pitch P ≦ cell thickness d and obtaining uniaxial alignment. And the electric field strength of the driving voltage can be lowered. As a result, it can be applied as a display material for a full-color display and can be adapted to a cell thickness capable of mass production.

3 is a graph showing V-shaped voltage-transmittance characteristics of Example 1. 6 is a graph showing V-shaped voltage-transmittance characteristics of Example 2.

Claims (15)

Between a substrate having a pair of electrode layers, a liquid crystal layer comprising a liquid crystal composition containing an optically active compound and a transparent solid material comprising a polymer precursor is provided, and the liquid crystal composition is optical in the liquid crystal layer. The polymer is stabilized in a uniaxially oriented state, and the helical pitch (the pitch (μm) of the helical structure that appears when no voltage is applied to the liquid crystal composition) and the cell thickness (the thickness of the liquid crystal layer (μm) )) Satisfies the following relationship:
Spiral pitch ≦ cell thickness The liquid crystal element according to claim 1, wherein the liquid crystal composition containing the optically active compound exhibits a smectic C * phase. The liquid crystal element according to claim 1, wherein the cell thickness is 3 μm or more. The liquid crystal element according to claim 1, wherein the polymer precursor contains a polyfunctional acrylate. The liquid crystal element according to claim 4, wherein the polymer precursor contains a polyfunctional acrylate having a mesogenic group and a polyfunctional acrylate having an alkyl side chain. The liquid crystal element according to claim 1, wherein the liquid crystal composition contains a pyrimidine-based liquid crystal compound. A liquid crystal composition containing an optically active compound and a polymer precursor that forms a transparent solid substance are sandwiched between a substrate having a pair of electrode layers to form a liquid crystal layer, and the helical pitch of the liquid crystal composition (the liquid crystal The pitch (μm) of the helical structure that appears in the voltage-free state of the composition and the cell thickness (thickness (μm) of the liquid crystal layer) satisfy the following relationship:
Spiral Pitch ≦ Cell Thickness The helical structure expressed by the liquid crystal composition is released from an external electric field or heated to release the helix, and the polymer precursor is cured (cross-linked) to stabilize the polymer, thereby eliminating the electric field. A liquid crystal device manufacturing method in which a uniaxial alignment state is exhibited, and an extinction position is continuously changed depending on the electric field strength by applying an electric field thereto. The manufacturing method according to claim 7, wherein the helical structure expressed by the liquid crystal composition is solved by an external electric field. The manufacturing method according to claim 8, wherein the external electric field is an alternating electric field. The manufacturing method according to claim 9, wherein the alternating electric field is a rectangular wave and the frequency is 10 to 10 kHz. The manufacturing method according to claim 7, wherein the helical structure expressed by the liquid crystal composition is solved by heating. The production method according to claim 11, wherein the phase that is exhibited when the liquid crystal layer is heated is a liquid crystal phase exhibiting optically uniaxial alignment. The production method according to claim 12, wherein the optically uniaxial orientation is a chiral nematic phase or a smectic A phase. The liquid crystal element according to claim 1, wherein the liquid crystal element has an extinction position that continuously changes depending on the electric field strength when an electric field is applied. The liquid crystal element has a V-shaped voltage-transmittance characteristic formed from a negative voltage value to a positive voltage value in a voltage-transmittance characteristic obtained with the vertical axis representing transmittance and the horizontal axis representing voltage. The liquid crystal element according to any one of 1 to 6.

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