JP4679973B2 - Liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal display element using a ferroelectric liquid crystal.

  Liquid crystal display elements have been widely used from large displays to portable information terminals because of their thinness and low power consumption, and their development is actively underway. To date, liquid crystal display elements have been developed and put to practical use, such as TN mode, STN multiplex drive, and active matrix drive using a thin film transistor (hereinafter sometimes referred to as a “TFT element”) for TN. However, since these use nematic liquid crystal, the response speed of the liquid crystal material is as slow as several ms to several tens of ms, so it cannot be said that it is sufficiently compatible with moving image display.

  On the other hand, there is a ferroelectric liquid crystal as a material suitable for a high-speed device because the response speed is as short as μs order. As such a ferroelectric liquid crystal, a bistable one having two stable states when no voltage is applied, which is proposed by Clark and Lagerwol, is widely known, but for switching in two states of light and dark. Although it has limited memory characteristics, it has a problem that gradation display cannot be performed.

  In recent years, the state of a liquid crystal layer when a voltage is not applied has been stabilized in one state (hereinafter referred to as “monostable”). ) Is continuously changed and analog modulation of the transmitted light intensity has been paid attention to enable gradation display (Non-Patent Document 1).

  As a method for monostabilizing the ferroelectric liquid crystal as described above, a polymer stabilization method in which an ultraviolet curable monomer is added to a liquid crystal material, injected into a cell, and then cured to stabilize the alignment of the liquid crystal, or There is a method in which a ferroelectric liquid crystal is heated to a temperature higher than the phase transition point and then slowly cooled.

  However, the polymer stabilization method has problems such as a complicated process and a high driving voltage. In the latter method that does not use the polymer stabilization method, two domains having different layer normal directions (hereinafter sometimes referred to as “double domains”) are easily formed, and the display is reversed in black and white during driving. It becomes a big problem. This double domain is known to be monodomain by an electric field applied slow cooling method that slowly cools while applying a voltage (Non-Patent Document 2). However, when the ferroelectric liquid crystal becomes higher than the phase transition point again, it is aligned. There is a problem that is disturbed, and practicality is low.

  In addition, as a technique for aligning liquid crystals, there are a rubbing method, a photo-alignment method, and the like. The rubbing method imparts orientation ability by rubbing the coated polyimide surface, but there are problems such as difficulty in uniformity during large area processing and generation of static electricity and dust. On the other hand, the photo-alignment method irradiates a compound having photo-alignment property with ultraviolet rays and the like to arrange molecules in a specific direction and imparts alignment ability. However, there is a problem that the apparatus cost is increased because an exposure process is required.

  On the other hand, in such a liquid crystal display element, two alignment substrates each having an electrode layer and an alignment layer are arranged on a base material so that the alignment layers face each other, and liquid crystal is filled between the alignment substrates. In general, a polarizing plate that converts incident non-polarized light into linearly polarized light is attached to the outside of the base material.

  As described above, since the liquid crystal display element uses the birefringence effect, a polarizing plate is required for visualization. However, by attaching the polarizing plate to the outside of the base material, There is a problem that light scattering occurs at the interface with the plate, and the light transmittance is likely to decrease.

  In recent years, there has been a demand for downsizing particularly in applications such as portable terminals, and liquid crystal display elements are required to be thin and lightweight. Responding to this requirement is desirable because it also leads to a reduction in manufacturing costs.

NONAKA, T., LI, J., OGAWA, A., HORNUNG, B., SCHMIDT, W., WINGEN, R., and DUBAL, H., 1999, Liq. Cryst., 26, 1599. PATEL, J., and GOODBY, J. W., 1986, J. Appl. Phys., 59, 2355.

  The present invention has been made in view of the above problems, and by providing one alignment layer with an alignment function for controlling the alignment of the ferroelectric liquid crystal and a deflection function for converting non-polarized light into linearly polarized light, To eliminate the light scattering that occurs at the interface between the polarizing plate and the liquid crystal display element, to suppress the decrease in light transmittance, to further reduce the thickness and weight of the liquid crystal display element, and to reduce the manufacturing cost Main purpose.

  As a result of intensive investigations in view of the above circumstances, the present inventors have made use of self-organization of plate-like molecules having photodichroism in the visible light region, so that a ferroelectric liquid crystal can be formed on the alignment layer by a simple method. An alignment function for controlling the alignment and a deflection function for changing non-polarized light to linearly polarized light can be imparted, and it can be visualized without using a polarizing plate on the alignment layer side, and the present invention has been completed. .

That is, in the present invention, a first alignment substrate having a first substrate, a first electrode layer formed on the first substrate, and a first alignment layer formed on the first electrode layer. And a second alignment substrate having a second substrate, a second electrode layer formed on the second substrate, and a second alignment layer formed on the second electrode layer. A liquid crystal display element, wherein the first alignment layer and the second alignment layer are arranged to face each other, and a ferroelectric liquid crystal is sandwiched between the first alignment substrate and the second alignment substrate,
The first alignment layer has a column structure in which plate-like molecules having optical dichroism in the visible light region are stacked with the normal direction of the plate-like molecules facing a certain direction, and the alignment function and the polarization function The present invention provides a liquid crystal display element characterized by being a columnar alignment layer having the following.

  The liquid crystal display element of the present invention has a first alignment layer, a column structure in which plate-like molecules having photodichroism in the visible light region are stacked with the normal direction of the plate-like molecules facing a certain direction, In addition, since it is a columnar alignment layer having an alignment function and a polarization function, it can be visualized without using a polarizing plate on the first alignment layer side, and the interface between the liquid crystal display element and the polarizing plate. Scattering of light generated in the above can be eliminated, and a decrease in light transmittance can be suppressed. In addition, since it is not necessary to use a polarizing plate on the first alignment layer side in this way, the liquid crystal display element can be reduced in thickness and weight, and further, the manufacturing cost can be reduced. Since such a columnar alignment layer is formed by utilizing the self-organization of the plate-like molecules, it can be formed by a simple method without requiring an alignment process such as a rubbing process or a photo-alignment process. And practicality is high.

  In the above invention, the columnar alignment layer has a resin layer in which concave portions or convex portions having a predetermined width are formed in a pattern on the surface, and the column structure formed along the concave portions of the resin layer. It is preferable. This is because the column structure can be arranged in a certain direction by being formed along the concave portion of the resin layer.

  In the invention, the plate-like molecule preferably exhibits a lyotropic liquid crystal phase in an aqueous solution. The plate-like molecule forms a column structure by self-organization in an aqueous solution and exhibits a lyotropic liquid crystal phase. Therefore, by applying a columnar alignment layer forming coating solution containing such a plate-like molecule, This is because the structure can be easily oriented. Moreover, it is because the immobilization process for immobilizing the column structure is facilitated because the plate-like molecules are water-soluble.

  Furthermore, in the above invention, the second alignment layer is preferably a photo-alignment film. This is because by using a photo-alignment film for the second alignment layer, there is no problem of static electricity or dust, and quantitative alignment processing can be performed.

  In the above invention, the ferroelectric liquid crystal preferably exhibits monostable driving characteristics. This is because when the ferroelectric liquid crystal exhibits monostable driving characteristics, gradation display is possible and a liquid crystal display element with high-definition color display can be obtained.

  In the above invention, the ferroelectric liquid crystal preferably exhibits a phase transition series that does not pass through the smectic A phase in the temperature lowering process. Ferroelectric liquid crystals exhibiting such phase transition series tend to exhibit monostable driving characteristics, and by using such ferroelectric liquid crystals, it is possible to obtain a liquid crystal display element with high-definition color display. This is because it becomes easy.

  In the invention described above, the first electrode layer or the second electrode layer preferably includes a thin film transistor (TFT element) and is driven by an active matrix. This is because by adopting an active matrix system using a TFT element, a target pixel can be reliably turned on and off, and a high-quality display becomes possible. Further, a TFT substrate in which TFT elements are arranged in a matrix on one base material and a common electrode substrate in which a common electrode is formed on the entire display portion on the other base material are combined, and the common electrode substrate A micro color filter arranged in a matrix of TFT elements can be formed between the common electrode and the substrate, and can be used as a liquid crystal display element for color display.

  Further, the above invention is preferably driven by a field sequential color system. Since the liquid crystal display element of the present invention has a high response speed and can align the ferroelectric liquid crystal without causing alignment defects, it can be driven by the field sequential color system, thereby reducing the power consumption and the cost. This is because a wide and bright, high-definition color moving image display can be obtained.

  According to the present invention, it is possible to visualize without using a polarizing plate on the first alignment layer side, eliminating light scattering occurring at the interface between the liquid crystal display element and the polarizing plate, and reducing the light transmittance. The decrease can be suppressed. Further, since it is not necessary to use a polarizing plate on the first alignment layer side as described above, it is possible to reduce the thickness and weight of the liquid crystal display element and to reduce the manufacturing cost. Since such a columnar alignment layer is formed by utilizing the self-organization of the plate-like molecules, it can be formed by a simple method without requiring an alignment process such as a rubbing process or a photo-alignment process. Can be practical.

  Hereinafter, the liquid crystal display element of the present invention will be described. The liquid crystal display element of the present invention has a first alignment having a first substrate, a first electrode layer formed on the first substrate, and a first alignment layer formed on the first electrode layer. A second alignment substrate comprising: a substrate; a second substrate; a second electrode layer formed on the second substrate; and a second alignment layer formed on the second electrode layer. A liquid crystal display element in which a first alignment layer and the second alignment layer are arranged to face each other, and a ferroelectric liquid crystal is sandwiched between the first alignment substrate and the second alignment substrate. The first alignment layer has a column structure in which plate-like molecules having photodichroism in the visible light region are stacked such that the normal direction of the plate-like molecules faces a certain direction, and has an alignment function and polarization. It is a columnar alignment layer having a function.

  As described above, the liquid crystal display element of the present invention has a column structure in which the first alignment layer is stacked with the plate-like molecules having photodichroism in the visible light region and the normal direction of the plate-like molecules is directed in a certain direction. And a columnar alignment layer having an alignment function and a polarization function, and can be visualized without using a polarizing plate on the first alignment layer side. Scattering of light generated at the interface between the light transmission and the light transmission can be suppressed. In addition, since it is not necessary to use a polarizing plate on the first alignment layer side in this way, the liquid crystal display element can be reduced in thickness and weight, and further, the manufacturing cost can be reduced. Since such a columnar alignment layer is formed by utilizing the self-organization of the plate-like molecules, it can be formed by a simple method without requiring an alignment process such as a rubbing process or a photo-alignment process. And practicality is high.

  Such a liquid crystal display element of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the liquid crystal display element of the present invention. As shown in FIG. 1, it has the 1st base material 1a, the 1st electrode layer 2a formed on the 1st base material 1a, and the 1st orientation layer 3a formed on the said 1st electrode layer 2a. The first alignment substrate 11 is formed, and the second base 1b, the second electrode layer 2b formed on the second base 1b, and the second base 2b formed on the second electrode layer 2b. A second alignment substrate 12 having an alignment layer 3b is formed, and the first alignment substrate 11 and the second alignment substrate 12 are arranged so that the first alignment layer 3a and the second alignment layer 3b face each other. Yes. Further, a ferroelectric liquid crystal is sandwiched between the first alignment layer 3a and the second alignment layer 3b, and the liquid crystal layer 5 is configured.

  In the liquid crystal display element of the present invention having such a structure, the first alignment layer 3a has a plate-like molecule having photodichroism in the visible light region, and the normal direction of the plate-like molecule is directed to a certain direction. This is a columnar alignment layer having a stacked column structure and having an alignment function and a polarization function. This columnar alignment layer will be described below.

  FIG. 2 (a) is a diagram showing a model structure and normal direction of a plate-like molecule having photodichroism in the visible light region used in the present invention, and FIG. 2 (b) shows the columnar alignment layer. It is a schematic perspective view. As shown in FIG. 2 (b), in this columnar alignment layer, the plate-like molecules a are stacked with the normal direction n of the plate-like molecules a facing a certain direction to form a column structure b. A plurality of column structures b are arranged to form a columnar alignment layer.

  In the present invention, since the columnar alignment layer is configured by arranging the plate-like molecules a in this way, the axial directions of the columns of the plurality of column structures b included in the columnar alignment layer are directed to a certain direction. The column structure b has an alignment function for controlling the alignment of the ferroelectric liquid crystal by the interaction between the ferroelectric liquid crystal and the column structure b.

  Moreover, the columnar alignment layer has anisotropy along the axial direction of the column by aligning the axial direction of the columns of the column structures b of the columnar alignment layer in a certain direction in this way. Since the plate-like molecule a constituting the column structure b has dichroism in the visible light region, the columnar alignment layer further has a polarizing function.

  In the present invention, since the columnar alignment layer has the alignment function and the deflection function in this way, it is not necessary to provide a polarizing plate on the side where the columnar alignment layer is provided on the two alignment substrates, and light generated at the interface. The liquid crystal display element can be made thinner and lighter, and the manufacturing cost can be reduced.

  In addition, since such a columnar alignment layer is formed by utilizing the self-organization of the plate-like molecule, the columnar alignment layer can be formed by a simple method without requiring alignment treatment, and has practicality. It will be expensive.

  Since the liquid crystal display element uses the birefringence effect as described above, the polarizing plate 4b is used for the second alignment substrate 12 for visualization. In FIG. 1, the polarizing plate 4b is formed outside the second substrate 1b, but the polarizing plate 4b may be formed inside the second substrate 1b, and its position is not particularly limited. Although not, the normal direction and the polarization direction of the plate molecules constituting the columnar alignment layer used as the first alignment layer 3a are arranged to be perpendicular. By arranging in this way, only light polarized in the alignment direction of the liquid crystal molecules can be transmitted.

  In such a liquid crystal display element of the present invention, for example, as shown in FIGS. 3 and 4, one substrate is a TFT substrate in which TFT elements are arranged in a matrix, and the other substrate is formed over the entire area. In addition, it is preferable that these are combined as the common electrode substrate and driven by an active matrix. As described above, since the liquid layer display element of the present invention is driven by an active matrix, the target pixel can be reliably turned on and off, so that a high-quality display can be obtained. An active matrix driving liquid crystal display element using such a TFT element will be described below.

  FIG. 3 is a schematic perspective view showing an example of the liquid crystal display element of the present invention, and FIG. 4 is a schematic cross-sectional view thereof. In FIG. 3, the first alignment substrate is a common electrode substrate with the first electrode layer 2a being a common electrode, while the second alignment substrate is the second electrode layer 2b having an x electrode 2c, a y electrode 2d, and The pixel electrode 2e is a TFT substrate. In such a liquid crystal display element, the x electrode 2c and the y electrode 2d are respectively arranged vertically and horizontally, and the TFT element 7 is operated by applying a signal to these electrodes to drive the ferroelectric liquid crystal. be able to. A portion where the x electrode 2c and the y electrode 2d intersect is insulated by an insulating layer (not shown), and the signal of the x electrode 2c and the signal of the y electrode 2d can operate independently. A portion surrounded by the x electrode 2c and the y electrode 2d is a pixel which is a minimum unit for driving the liquid crystal display element of the present invention, and at least one TFT element 7 and a pixel electrode 2e are formed in each pixel. . In the liquid crystal display element of the present invention, the TFT element 7 of each pixel can be operated by sequentially applying a signal voltage to the x electrode 2c and the y electrode 2d. In FIG. 3, the liquid crystal layer, the first alignment layer, the second alignment layer, and the polarizing plate are omitted.

  Such a liquid crystal display element of the present invention can be used as a color liquid crystal display element by adopting a color filter system or a field sequential color system, and among them, it is preferable that the liquid crystal display element is driven by a field sequential color system. The field sequential color system enables color display without using a color filter by turning on and off the liquid crystal in synchronization with the blinking of the three red, green, and blue LEDs, and has low power consumption and low cost. This is because a bright and high-definition color moving image display with a wide viewing angle can be realized.

  In this case, the ferroelectric liquid crystal preferably exhibits monostable driving characteristics, but in particular, half V-shaped driving in which liquid crystal molecules operate only when a positive or negative voltage is applied. More preferably. By using such a material as the ferroelectric liquid crystal, it is possible to reduce light leakage at the time of dark part operation (when the black and white shutter is closed), and it is possible to take a sufficiently long opening time as a black and white shutter. This is because each color that can be switched over time can be displayed brighter, and a bright color liquid crystal display element can be obtained.

  On the other hand, when a color liquid crystal display element is adopted by adopting a color filter system, a micro color arranged in a matrix of TFT elements 7 between the first electrode layer 2a, which is the common electrode, and the substrate 1a. A filter may be formed.

  Thus, the liquid crystal display element of this invention arrange | positions a 1st alignment substrate and a 2nd alignment substrate so as to oppose, and sandwiches a ferroelectric liquid crystal between these alignment substrates. Each component of the liquid crystal display element of the present invention having such a structure will be described below.

(1) First Alignment Substrate First, the first alignment substrate used in the present invention will be described. In the present invention, the first alignment substrate has a first substrate, a first electrode layer formed on the first substrate, and a first alignment layer formed on the first electrode layer. It is.

a. First Alignment Layer The first alignment layer used in the present invention has a column structure in which plate-like molecules having photodichroism in the visible light region are stacked with the normal direction of the plate-like molecules facing a certain direction. And a columnar alignment layer having an alignment function and a polarization function.

  As described above, the columnar alignment layer used in the present invention has a column structure, and has an alignment function for controlling the alignment of the ferroelectric liquid crystal by the interaction between the column structure and the ferroelectric liquid crystal. . In addition, since the plate-like molecules constituting the column structure have dichroism in the visible light region as described above, and the columnar alignment layer has anisotropy in the axial direction of the column, it has a polarizing function. It will have.

  Since such a columnar alignment layer is formed by utilizing the self-organization of the plate-like molecules, the manufacturing process is simple without requiring alignment treatment such as rubbing treatment or photo-alignment treatment, This has the advantage of not incurring device costs. For example, a columnar alignment layer having the above column structure can be formed by applying a coating liquid for forming a columnar alignment layer to form a coating film, and drying and fixing the coating film. The method for forming the columnar alignment layer will be described in detail later.

  Thus, the columnar alignment layer of the present invention has the column structure as described above, and is not particularly limited as long as it has an alignment function and a deflection function, but has a predetermined width on the surface. It is preferable to have a resin layer in which concave portions or convex portions are formed in a pattern and the column structure formed along the concave portions of the resin layer. This is because the column structure can be easily arranged by forming the column structure along the concave portion of the resin layer. Hereinafter, such a column structure and a resin layer will be described.

(Column structure)
First, the column structure constituting the columnar alignment layer will be described. The column structure used in the present invention is constituted by laminating plate-like molecules having photodichroism in the visible light region with their normal direction facing a certain direction.

  Here, the plate-like molecule means a molecule having at least a plurality of aromatic ring structures and having a core portion of the molecule arranged in a planar shape.

  The plate-like molecule used in the present invention is not particularly limited as long as it forms a column structure by stacking in a columnar shape.

  Examples of such a plate-like molecule include a plate-like molecule having a hydrophilic group such as a sulfonic acid group or a plate-like molecule having a hydrophobic group such as a long-chain alkyl group. Among these, it is preferable to use a plate molecule having a hydrophilic group. This is because the plate-like molecule having a hydrophilic group has a small hydrophilic group and the distance between adjacent column structures is short, so that the column structures can be easily arranged. Moreover, it is because the immobilization treatment is facilitated by neutralizing hydrophilic portions such as sulfonic acid groups after application and drying to make them insoluble or insoluble in water.

  Examples of the hydrophilic group include a sulfonic acid group such as a sulfonic acid group, a sodium sulfonate group, an ammonium sulfonate group, a lithium sulfonate group, and a potassium sulfonate group, a carboxyl group, a sodium carboxylate group, and a carboxylic acid. Examples thereof include carboxylic acid-based hydrophilic groups such as ammonium group, lithium carboxylate group, and potassium carboxylate group, hydroxyl groups, and amino groups. Of these, sulfonic acid-based hydrophilic groups are preferred.

  In addition, it can be confirmed by measuring using a X-ray-diffraction apparatus that a plate-shaped molecule | numerator forms the column structure.

  Among the above, the plate-like molecules used in the present invention are preferably those that form the column structure in a solution and exhibit a lyotropic liquid crystal phase. This is because the plate-like molecules exhibiting the lyotropic liquid crystal phase in the solution have a high self-organizing power. For example, by applying a coating liquid for forming a columnar alignment layer containing a plate-like molecule exhibiting a lyotropic liquid crystal phase in a solution, the column structure can be easily aligned using self-organization of the plate-like molecule. .

  Examples of the plate-like molecule that exhibits a lyotropic liquid crystal phase in such a solution include a plate-like molecule that exhibits a lyotropic liquid crystal phase in an aqueous solution, or a plate-like molecule that exhibits a lyotropic liquid crystal phase in an organic solvent. The type of the solution differs depending on the substituent of the plate molecule, and when the plate molecule has a hydrophilic group such as a sulfonic acid group, an aqueous solution is used, and a hydrophobic property such as a long chain alkyl group. When it has a group, an organic solvent is used.

  Among these, the plate-like molecule is preferably one that forms a column structure in an aqueous solution and exhibits a lyotropic liquid crystal phase. Such a plate-like molecule forms a column structure by self-organization in an aqueous solution and exhibits a lyotropic liquid crystal phase. Therefore, by applying a columnar alignment layer-forming coating solution containing this plate-like molecule, This is because the structure can be easily oriented. Furthermore, because the plate-like molecule is water-soluble, an immobilization process for immobilizing the column structure is facilitated.

  Specific examples of such plate-like molecules having photodichroism in the visible light region and exhibiting a lyotropic liquid crystal phase in an aqueous solution include substances represented by the following chemical formula.

The alkyl group in each chemical formula is preferably one having 1 to 4 carbon atoms. The halogen in each chemical formula is preferably Cl or Br. Further, as the cation in the above ^{formula, H +, Li +, Na} +, K +, Cs + or _NH ^{4 +} and the like.

  In the present invention, among the above substances, substances represented by the above chemical formulas I to V are preferably used. Moreover, the said substance can also be used individually by 1 type or in combination of 2 or more types.

  Furthermore, examples of the material containing plate-like molecules having dichroism in the visible light region and exhibiting a lyotropic liquid crystal phase in an aqueous solution include “N015” manufactured by Optiva.

  Further, the plate-like molecules are not limited to those showing a lyotropic liquid crystal phase as described above, and may show a thermotropic liquid crystal phase.

(Resin layer)
The column structure can be aligned in a certain direction by forming the recesses or protrusions having a predetermined width on the surface along the recesses of the resin layer formed in a pattern. The shape of the pattern of such recesses or projections is not particularly limited as long as the plate-like molecule can form the column structure, but the recesses or projections are regularly arranged at regular intervals in a stripe shape. It is preferable that the pattern is formed automatically.

  The width of the concave portion varies depending on the type of plate-like molecule used, but is usually within a range of 0.1 μm to 10 μm, preferably within a range of 0.2 μm to 1 μm, particularly 0.2 μm to 0 μm. It is preferable to be within the range of 4 μm. This is because it is difficult for the manufacturing method to make the width of the concave portion narrower than the above range, and conversely, if the width of the concave portion is too wide, it may be difficult to arrange the column structure.

  The depth of the recess is more preferably in the range of 0.05 μm to 1 μm, and more preferably in the range of 0.1 μm to 0.2 μm. If the depth of the recess is too shallow, the function of aligning the plate-like molecules constituting the column structure is lowered, and if the recess is too deep, the orientation of the ferroelectric liquid crystal may be adversely affected.

  Here, the interval at which the recesses are formed in a stripe shape varies depending on the type of plate-like molecule used, but usually the interval between the ends of the adjacent recesses and the ends of the recesses, that is, the protrusions. Is not more than half of the wavelength of visible light, preferably in the range of 0.05 μm to 2 μm, more preferably in the range of 0.1 μm to 1 μm, especially in the range of 0.1 μm to 0.2 μm. Is preferred. This is because it is difficult to make the interval between adjacent concave portions narrow in terms of the manufacturing method, and if it is too wide, it is difficult to arrange the column structure. Further, if the interval between adjacent concave portions is a value close to the wavelength of light, there is a problem of optical coloring due to light diffraction.

  The pitch of the recesses is appropriately selected depending on the type of plate-like molecule described later, but is usually in the range of 0.1 μm to 10 μm, preferably in the range of 0.2 μm to 1 μm, particularly 0. It is preferable to be within the range of 2 μm to 0.4 μm. This is because it is difficult for the manufacturing method to form the pitch of the recesses narrower than the above range, and conversely, if the pitch of the recesses is too wide, it may be difficult to arrange the column structure. Here, the pitch of the recesses means the distance from the center of the adjacent recesses to the center of the recesses.

  The cross-sectional shape of the concave portion of the resin layer is not particularly limited, and may be a rectangle or other shapes such as a trapezoid. In the present invention, it is particularly preferable that the recess has a rectangular cross-sectional shape from the viewpoint that the column structure can be easily aligned and oriented in a certain direction.

  The resin layer having such a recess or projection is, for example, a substrate for forming a recess having a projection that is symmetrical to the shape of the target recess, and sandwiching the substrate for forming the recess and the curable resin composition. A recess-forming substrate for forming the resin layer by curing is prepared, and the recess-forming substrate and the recess-forming substrate coated with the curable resin composition are used as the curable resin composition. It can form by peeling the said board | substrate for recessed part formation, after superposing | stacking an object and hardening the said curable resin composition.

  Examples of the curable resin used in such a curable resin composition include unsaturated polyester, melamine, epoxy, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, and polyether (meth) acrylate. A curable resin such as polyol (meth) acrylate, melamine (meth) acrylate, or triazine acrylate may be used alone or in combination. The resin composition may be a thermosetting resin or an ultraviolet curable resin, or may be a combination of these.

  In addition, the resin composition may be added with various additives such as a curing agent and a photopolymerization initiator, if necessary, and a solvent for applying to the substrate for forming a recess. It is also possible to adjust the viscosity using a monomer or the like.

  Moreover, as a film thickness of the said resin layer, the thickness of the part in which the recessed part is formed normally shall be 1 micrometer or less, Preferably it shall be 0.2 micrometer or less. It is because the liquid crystal display element of this invention may become heavy when the thickness of the part in which the recessed part is formed is too thick. In consideration of thinning of the liquid crystal display element, it is preferable that the thickness of the portion where the recess is formed is thin. However, since it is difficult to form a too thin portion, the thickness of the portion where the recess is formed. Is usually 0.1 μm or more.

  Here, in the present invention, when such a concavo-convex structure is replicated, the surface of the formed resin layer may have high water repellency, but the columnar alignment layer-forming coating is formed on the resin layer. Since the liquid is applied, the resin layer is preferably hydrophilic. Therefore, a hydrophilic layer may be provided on the resin layer, or the surface of the resin layer may be subjected to a hydrophilic treatment. Examples of the surface treatment so as to make the surface of the resin layer lyophilic include lyophilic surface treatment by plasma treatment using argon or water, and the lyophilic property formed on the resin layer. Examples of the layer include a silica film formed by a sol-gel method of tetraethoxysilane.

(Columnar alignment layer)
The thickness of the columnar alignment layer used in the present invention varies depending on the required characteristics of the liquid crystal display element. In addition, the columnar alignment layer has a column structure and a resin layer. It depends on the case. For example, when the columnar alignment layer is a single layer having a column structure, the thickness of this columnar alignment layer is usually preferably in the range of 50 nm to 2000 nm, more preferably in the range of 100 nm to 1000 nm, and in the range of 200 nm to 500 nm. The inside is more preferable. If the thickness of the columnar alignment layer is too small, the alignment of the ferroelectric liquid crystal may not be sufficiently controlled. On the other hand, if it is too thick, alignment disturbance may occur in the vicinity of the surface, which is not preferable in terms of cost.

  The transmittance of the columnar alignment layer is preferably 20% or more, more preferably 30% or more over the entire region. The transmittance can be measured with an ultraviolet-visible spectrophotometer.

  Such a columnar alignment layer forms a column structure composed of the plate-like molecules in a columnar alignment layer-forming coating solution obtained by adding the plate-like molecules in a solvent, and applies this coating solution. Thus, it can be formed on the substrate while maintaining the column structure.

  The columnar alignment layer-forming coating solution may contain a liquid crystal material in addition to the plate-like molecules. For example, even if the plate-like molecules are difficult to form a column structure, the plate-like molecules can be aligned along the alignment direction of the liquid crystal material by aligning the liquid crystal material. . As such a liquid crystal material, a liquid crystal material generally used for forming a polarizing layer can be used. In addition, the liquid crystal composition containing the liquid crystal material and the plate molecule may be a lyotropic liquid crystal phase or a thermotropic liquid crystal phase, but is usually a thermotropic liquid crystal. Is used.

  The solvent used in the columnar alignment layer forming coating solution is appropriately selected depending on the substituent introduced into the plate molecule. For example, when a hydrophilic group such as a sulfonic acid group is introduced, water is used as the solvent. On the other hand, when a hydrophobic group such as a long-chain alkyl group is introduced, an organic solvent is used. As such an organic solvent, you may contain various additives, such as surfactants, such as polyethyleneglycol, as needed. Among these, in the present invention, the columnar alignment layer forming coating solution is preferably aqueous. This is because the immobilization process described later becomes easy.

  The method for applying the columnar alignment layer-forming coating solution is not particularly limited as long as the normal direction of the plate-like molecules can be aligned in a certain direction. For example, various coating methods such as Mayer bar coating, gravure coating, die coating, dip coating, and spray coating, screen printing methods, ink jet methods, and the like can be used. This coating method can be appropriately determined depending on whether the column structure is formed on a flat surface or an uneven surface such as the resin layer.

  For example, when the column structure is formed on a plane, it is preferable to use a coating method in which shear stress is applied among the above. This is because the column structure can be easily formed by using a coating method in which shear stress is applied.

  Examples of the coating method in which shear stress is applied include Mayer bar coating, slot die coating, and slide coating. Among these, it is preferable to use slot die coating.

  On the other hand, when the column structure is formed on an uneven surface such as the resin layer, it is preferable that the column structure is formed along the uneven shape on the resin layer using a coating method that does not apply shear stress. In this case, as an application method, an inkjet method, a spray coating, a dip coating, or a flexographic printing method can be preferably used, and among these, an inkjet method is more preferable.

  After applying the columnar alignment layer forming coating solution, the solvent contained in the coating film is evaporated to dry the coating film. As a drying method, a method generally used for drying a solvent, for example, heat drying, room temperature drying, freeze drying, far infrared drying, or the like can be used.

After drying, it is preferable to perform an immobilization treatment for immobilizing the orientation state of the plate-like molecules. For example, when the plate-like molecule to be used has a hydrophilic group, the column structure can be stabilized by applying a hydrophobizing treatment, and water resistance can be imparted to the columnar alignment layer. The hydrophobizing solution used for the hydrophobizing treatment is not particularly limited as long as it makes the hydrophilic group insoluble or hardly soluble in water by crosslinking, for example, and the plate-like molecule used is not limited. It depends on the hydrophilic group. Specifically, an aqueous solution of an alkaline earth metal salt such as a barium salt, a calcium salt, or a magnesium salt can be used, and examples thereof include an aqueous barium chloride solution, an aqueous magnesium chloride solution, and an aqueous calcium chloride solution. For example, when the plate molecule has an SO ₃ NH ₄ group, the sulfonate ion of this SO ₃ NH ₄ group and the barium ion are bonded to each other to cross-link adjacent plate molecules and immobilize the column structure. The

  The hydrophobizing treatment method is not particularly limited as long as it is a method capable of hydrophobizing the hydrophilic group, and after applying the columnar alignment layer forming coating solution and drying, the hydrophobizing treatment solution The method of apply | coating and the method of immersing in the said hydrophobic treatment liquid are mentioned. After application or immersion of this hydrophobizing treatment liquid, a columnar alignment layer can be obtained by washing and drying.

  On the other hand, when the plate molecule has a hydrophobic group such as a long chain alkyl group, a polymerizable group is introduced into the core portion of the plate molecule or a part of the alkyl side chain, and this polymerizable group is polymerized. Thus, the plate-like molecule can be cross-linked in a linear or network form, and the column structure can be fixed.

  Furthermore, when the columnar alignment layer forming coating liquid contains a liquid crystal material, the alignment state of the plate-like molecules can be fixed by polymerizing the liquid crystal material. In this case, the liquid crystal material needs to have a polymerizable group.

  Thus, in the present invention, the columnar alignment layer can be formed by simply applying the columnar alignment layer-forming coating solution and performing simple post-treatment. I can say that.

b. 1st base material It will not specifically limit if it is generally used as a base material of a liquid crystal display element as a 1st base material used for this invention, For example, a glass plate, a plastic plate, etc. are mentioned preferably. The surface roughness (RSM value) of the substrate used in the present invention is preferably 10 nm or less, more preferably 3 nm or less, and still more preferably 1 nm or less. The surface roughness is a value measured using an atomic force microscope (AFM).

c. First Electrode Layer The first electrode layer used in the present invention drives the ferroelectric liquid crystal by applying a signal voltage to the ferroelectric liquid crystal.

  The first electrode layer is not particularly limited as long as it is generally used as an electrode layer of a liquid crystal display element, but at least one of the first electrode layer and the second electrode layer is transparent. It is preferable to form with a conductor. Preferred examples of the transparent conductor material include indium oxide, tin oxide, indium tin oxide (ITO), and the like.

  For example, when the liquid crystal display element of the present invention is to be driven by an active matrix using a TFT element, one of the first electrode layer and the second electrode layer is a whole surface common electrode formed of the transparent conductor. On the other hand, it is preferable that the x electrode and the y electrode are arranged in a matrix, and the TFT element and the pixel electrode are arranged in a portion surrounded by the x electrode and the y electrode.

  Among these electrodes, the transparent conductive film which is used as a common electrode on the entire surface can be formed on the substrate by a vapor deposition method such as a CVD method, a sputtering method, or an ion plating method. Further, the x electrode and the y electrode can be formed by forming a conductive film of a metal such as chromium or aluminum by the above-described vapor deposition method and patterning it in a matrix. As the patterning method, a general method such as a photolithography method can be used.

(2) Second Alignment Substrate Next, the second alignment substrate used in the present invention will be described. In the present invention, the second alignment substrate has a second base material, a second electrode layer formed on the second base material, and a second alignment layer formed on the second electrode layer. It is. Hereinafter, each constituent member of the second alignment substrate will be described. However, the second base material and the second electrode layer are the same as those described in the column of the first alignment substrate, so description thereof will be omitted here. .

a. Second Alignment Layer First, the second alignment layer will be described. The second alignment layer used in the present invention is not particularly limited as long as it has an alignment function for aligning the ferroelectric liquid crystal, and examples thereof include a photo alignment film and an alignment film formed by a rubbing alignment film. In the present invention, it is preferable to use a photo-alignment film among these alignment films. This is because the photo-alignment film is free from problems such as static electricity and dust, and enables quantitative alignment processing. The photo-alignment film referred to here is a film in which anisotropy is imparted by irradiating light onto a substrate coated with a constituent material of the photo-alignment film as will be described later and causing a photoexcitation reaction. It has an alignment function for controlling the alignment of liquid crystal molecules depending on the property.

  The constituent material of the photo-alignment film used in the present invention is not particularly limited as long as it has an effect of aligning the ferroelectric liquid crystal by causing such a photo-excitation reaction, and causes this excitation reaction. The wavelength region of light is preferably in the ultraviolet light range, that is, in the range of 10 nm to 400 nm, and more preferably in the range of 250 nm to 380 nm.

  As such materials, photoisomerization type materials that impart anisotropy to the photo-alignment film by causing a photoreaction and anisotropy to the photo-alignment film by causing a photoisomerization reaction And photoisomerization reaction type materials. Each will be described below.

(Photoreactive type)
First, a photoreactive component material will be described. As described above, the photoreactive component material is a material that imparts anisotropy to the photoalignment film by causing a photoreaction. The photo-reactive constituent material used in the present invention is not particularly limited as long as it has such characteristics, but among them, the photo-alignment film is caused by causing a photodimerization reaction or a photodecomposition reaction. A material that imparts anisotropy is preferred.

  The photodimerization reaction here is a reaction in which the reaction site oriented in the polarization direction by light irradiation is radically polymerized and two molecules are polymerized, and this reaction stabilizes the orientation in the polarization direction, and the photo-alignment film Can be provided with anisotropy. On the other hand, the photodecomposition reaction refers to a reaction that decomposes molecular chains such as polyimide oriented in the polarization direction by light irradiation. This reaction leaves molecular chains aligned in the direction perpendicular to the polarization direction, and photo-alignment. Anisotropy can be imparted to the film. Among these, in the present invention, it is preferable to use a material utilizing a photodimerization reaction. This is because a material using a photodimerization reaction has high exposure sensitivity and a wide range of material selection.

  The photoreactive material utilizing such a photodimerization reaction is not particularly limited as long as it is a material that can impart anisotropy to the photoalignment film by the photodimerization reaction, but is radically polymerizable. It is preferable that the photodimerization reactive compound which has the dichroism which has the functional group of this and has dichroism which makes absorption different with polarization directions is included. This is because by radical polymerization of the reaction site oriented in the polarization direction, the orientation of the photodimerization reactive compound is stabilized and anisotropy can be easily imparted to the photo-alignment film.

  Examples of the photodimerization reactive compound having such characteristics include a dimerization reactive polymer having at least one reactive site selected from a cinnamic acid ester, coumarin, quinoline, and chalcone group as a side chain. .

  Among these, the photodimerization reactive compound is preferably a dimerization reactive polymer containing cinnamate, coumarin or quinoline as a side chain. This is because anisotropy can be easily imparted to the photo-alignment film by radical polymerization of α and β unsaturated ketone double bonds aligned in the polarization direction as reaction sites.

  The main chain of the dimerization reactive polymer is not particularly limited as long as it is generally known as a polymer main chain, but the reaction sites of the side chains such as aromatic hydrocarbon groups are not limited. It is preferable that it does not have a substituent containing a lot of π electrons that hinders the interaction.

  The weight average molecular weight of the dimerization reactive polymer is not particularly limited, but is preferably in the range of 5,000 to 40,000, and is preferably in the range of 10,000 to 20,000. Is more preferable. The weight average molecular weight can be measured by a gel permeation chromatography (GPC) method. If the weight average molecular weight of the dimerization reactive polymer is too small, it may not be possible to impart appropriate anisotropy to the photo-alignment film. On the other hand, if it is too large, the viscosity of the coating liquid at the time of forming the photo-alignment film becomes high and it may be difficult to form a uniform coating film.

  As a dimerization reactive polymer, the compound represented by a following formula can be illustrated.

In the above formula, M ¹ and M ² each independently represent a monomer unit of a homopolymer or a copolymer. Examples thereof include ethylene, acrylate, methacrylate, 2-chloroacrylate, acrylamide, methacrylamide, 2-chloroacrylamide, styrene derivatives, maleic acid derivatives, and siloxane. M ² may be acrylonitrile, methacrylonitrile, methacrylate, methyl methacrylate, hydroxyalkyl acrylate or hydroxyalkyl methacrylate. x and y represent the molar ratio of each monomer unit in the case of a copolymer, and are numbers satisfying 0 <x ≦ 1, 0 ≦ y <1 and satisfying x + y = 1, respectively. It is. n represents an integer of 4 to 30,000. D ¹ and D ² represent spacer units.

R ¹ is a group represented by -A- (Z ¹ -B) _z -Z ^2- , and R ² is a group represented by -A- (Z ¹ -B) _z -Z ^3- . Here, A and B are each independently a covalent single bond, pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,4-cyclohexylene, 1,3-dioxane-2,5- Diyl or 1,4-phenylene which may have a substituent is represented. Z ¹ and Z ² are each independently a covalent single bond, —CH ₂ —CH ₂ —, —CH ₂ O—, —OCH ₂ —, —CONR—, —RNCO—, —COO— or — Represents OOC-. R is a hydrogen atom or a lower alkyl group, and Z ³ is a hydrogen atom or an alkyl or alkoxy having 1 to 12 carbon atoms, which may have a substituent, cyano, nitro, or halogen. z is an integer of 0-4. E ¹ represents a photodimerization reaction site, and examples thereof include cinnamic acid ester, coumarin, quinoline, chalcone group and the like. j and k are each independently 0 or 1.

  As such a dimerization reactive polymer, More preferably, the compound represented by a following formula can be mentioned.

  Among the dimerization reactive polymers, at least one of compounds 1 to 4 represented by the following formula is particularly preferable.

  In the present invention, as the photodimerization reactive compound, various photodimerization reaction sites and substituents can be selected from the above-mentioned compounds according to required characteristics. Moreover, the photodimerization reactive compound can also be used individually by 1 type or in combination of 2 or more types.

  In addition to the photodimerization reactive compound, the photoreactive material using photodimerization reaction may contain an additive within a range that does not interfere with the photoalignment property of the photoalignment film. Examples of the additive include a polymerization initiator and a polymerization inhibitor.

  The polymerization initiator or polymerization inhibitor may be appropriately selected from generally known compounds according to the type of the photodimerization reactive compound. The addition amount of the polymerization initiator or the polymerization inhibitor is preferably in the range of 0.001% by weight to 20% by weight, and in the range of 0.1% by weight to 5% by weight with respect to the photodimerization reactive compound. It is more preferable that

  In addition, as a photoreactive type material using a photodecomposition reaction, the polyimide "RN1199" by Nissan Chemical Industries Ltd. etc. can be mentioned, for example. Examples of the photoreactive material using photodimerization reaction include “ROP102” and “ROP103” manufactured by Rolic technologies.

  Next, a method for producing a photo-alignment film when using the photoreactive material will be described. In the present invention, the method for producing the photo-alignment film is not particularly limited as long as it can impart anisotropy to the photo-alignment film. For example, the photo-alignment film is opposed to the liquid crystal layer of the substrate provided with the electrode layer. On the surface to be coated, a coating liquid obtained by diluting the constituent material of the above-described photo-alignment film with an organic solvent is coated, dried, and a photo-alignment film can be formed by performing photo-alignment treatment on the obtained film. .

  In this case, the content of the photodimerization reactive compound in the coating liquid is preferably in the range of 0.05% by weight to 10% by weight, and in the range of 0.2% by weight to 2% by weight. More preferably. If the content of the photodimerization reactive compound is too small, it will be difficult to impart adequate anisotropy to the alignment film. Conversely, if the content is too large, the viscosity of the coating solution will increase, and a uniform coating will be formed. Because it becomes difficult to do.

  As the coating method, a spin coating method, a roll coating method, a rod bar coating method, a spray coating method, an air knife coating method, a slot die coating method, a wire bar coating method, or the like can be used.

  The thickness of the polymer film obtained by coating the constituent materials is preferably in the range of 1 nm to 200 nm, and more preferably in the range of 3 nm to 100 nm. If the thickness of the polymer film is too small, sufficient optical alignment may not be obtained. Conversely, if the thickness is too large, liquid crystal molecules may be disturbed in alignment, and this is not preferable in terms of cost. It is.

  The obtained polymer film can impart anisotropy by causing a photoexcitation reaction by irradiating light with controlled polarization. The wavelength range of the light to be irradiated may be appropriately selected according to the constituent material of the photo-alignment film to be used, but is preferably in the ultraviolet light range, that is, in the range of 100 nm to 400 nm, more preferably 250 nm. Within the range of ˜380 nm.

  The polarization direction is not particularly limited as long as it can cause the above-described photoexcitation reaction. However, since the alignment state of the ferroelectric liquid crystal can be improved, the polarization direction is substantially the same as the substrate surface. Preferably it is vertical.

(Photoisomerization type)
Next, the photoisomerization type material will be described. In the present invention, the photoisomerization type material is a material that imparts anisotropy to the photo-alignment film by causing a photoisomerization reaction as described above, and any material having such characteristics can be used. Although not particularly limited, it is more preferable to include a photoisomerization reactive compound that imparts anisotropy to the photoalignment film by causing a photoisomerization reaction. By including such a photoisomerization-reactive compound, a stable isomer among a plurality of isomers is increased by light irradiation, whereby anisotropy can be imparted to the photo-alignment film. .

  Such a photoisomerization-reactive compound is not particularly limited as long as it is a material having the above-mentioned characteristics, but has a dichroism that makes absorption different depending on the polarization direction, and light It is preferable that a photoisomerization reaction is caused by irradiation. This is because anisotropy can be easily imparted to the photo-alignment film by causing isomerization of the reaction site oriented in the polarization direction of the photoisomerization-reactive compound having such characteristics.

  The photoisomerization reaction that produces such a photoisomerization-reactive compound is preferably a cis-trans isomerization reaction. This is because either the cis isomer or the trans isomer is increased by light irradiation, whereby anisotropy can be imparted to the photo-alignment film.

  Examples of such photoisomerization-reactive compounds include monomolecular compounds and polymerizable monomers that are polymerized by light or heat. These may be selected as appropriate according to the type of ferroelectric liquid crystal used, but the anisotropy is imparted to the photo-alignment film by light irradiation, and then the anisotropy is stabilized by polymerizing. Therefore, it is preferable to use a polymerizable monomer. Among such polymerizable monomers, an acrylate monomer and a methacrylate monomer are preferable because anisotropy is imparted to the photo-alignment film and the polymer can be easily polymerized while maintaining the anisotropy in a good state. .

  The polymerizable monomer may be a monofunctional monomer or a polyfunctional monomer. However, since the anisotropy of the photo-alignment film due to polymerization becomes more stable, the bifunctional monomer It is preferable that

  Specific examples of such a photoisomerization-reactive compound include compounds having a cis-trans isomerization-reactive skeleton such as an azobenzene skeleton or a stilbene skeleton.

  In this case, the number of cis-trans isomerization reactive skeletons contained in the molecule may be one or two or more, but the alignment control of the ferroelectric liquid crystal becomes easy. Two are preferable.

  The cis-trans isomerization reactive skeleton may have a substituent in order to further enhance the interaction with the liquid crystal molecules. The substituent is not particularly limited as long as it can enhance the interaction with the liquid crystal molecules and does not interfere with the orientation of the cis-trans isomerization reactive skeleton, and examples thereof include a carboxyl group and a sulfonic acid. A sodium group, a hydroxyl group, etc. are mentioned. These structures can be appropriately selected depending on the type of ferroelectric liquid crystal used.

In addition to the cis-trans isomerization reactive skeleton, the photoisomerization reactive compound has many π electrons such as aromatic hydrocarbon groups so that the interaction with the liquid crystal molecules can be further enhanced. It may have an included group, and the cis-trans isomerization reactive skeleton and the aromatic hydrocarbon group may be bonded via a bonding group. The bonding group is not particularly limited as long as it can enhance the interaction with the liquid crystal molecule. For example, —COO—, —OCO—, —O—, —C≡C—, —CH ₂ —CH _2- , —CH ₂ O—, —OCH ₂ — and the like can be mentioned.

  In addition, when using a polymerizable monomer as a photoisomerization reactive compound, it is preferable to have the said cis-trans isomerization reactive skeleton as a side chain. By having the cis-trans isomerization reactive skeleton as a side chain, the effect of anisotropy imparted to the photo-alignment film becomes larger, and is particularly suitable for controlling the alignment of ferroelectric liquid crystals Because it becomes. In this case, the aromatic hydrocarbon group or bonding group contained in the molecule is contained in the side chain together with the cis-trans isomerization reactive skeleton so that the interaction with the liquid crystal molecule is enhanced. It is preferable.

  Further, the side chain of the polymerizable monomer may have an aliphatic hydrocarbon group such as an alkylene group as a spacer so that the cis-trans isomerization reactive skeleton can be easily oriented.

  Among the photoisomerization reactive compounds of the monomolecular compound or polymerizable monomer as described above, the photoisomerization reactive compound used in the present invention is preferably a compound having an azobenzene skeleton in the molecule. This is because the azobenzene skeleton contains a lot of π electrons, and thus has a strong interaction with liquid crystal molecules and is particularly suitable for controlling the alignment of ferroelectric liquid crystals.

  Hereinafter, the reason why an anisotropy can be imparted to the photo-alignment film by causing the azobenzene skeleton to undergo a photoisomerization reaction will be described. First, when the azobenzene skeleton is irradiated with linearly polarized ultraviolet light, the trans azobenzene skeleton having the molecular long axis oriented in the polarization direction is changed to a cis isomer as shown in the following formula.

  Since the cis isomer of the azobenzene skeleton is chemically unstable compared to the trans isomer, it thermally or absorbs visible light and returns to the trans isomer. Whether to become the right transformer body occurs with the same probability. Therefore, if the ultraviolet light is continuously absorbed, the ratio of the right-side trans isomer increases, and the average orientation direction of the azobenzene skeleton becomes perpendicular to the polarization direction of the ultraviolet light. In the present invention, by utilizing this phenomenon, the alignment direction of the azobenzene skeleton is aligned, anisotropy is imparted to the photo-alignment film, and the alignment of liquid crystal molecules on the film can be controlled.

  Among such compounds having an azobenzene skeleton in the molecule, examples of the monomolecular compound include compounds represented by the following formula.

In the above formula, each R ²¹ independently represents a hydroxy group. R ²² is _{^{- (A 21 -B 21 -A 21}} ) m - (D 21) n - represents a linking group represented ^{by, R 23} is _{^{(D 21) n - (A}} 21 -B 21 -A 21) _m represents a linking group represented by-. Here, A ²¹ represents a divalent hydrocarbon group, B ²¹ represents —O—, —COO—, —OCO—, —CONH—, —NHCO—, —NHCOO— or —OCONH—, and m represents Represents an integer of 0 to 3; D ²¹ represents a divalent hydrocarbon group when m is 0, and —O—, —COO—, —OCO—, —CONH—, —NHCO—, —NHCOO— when m is an integer of 1 to 3. Alternatively, -OCONH- is represented, and n represents 0 or 1. R ²⁴ each independently represents a halogen atom, a carboxy group, a halogenated methyl group, a halogenated methoxy group, a cyano group, a nitro group, a methoxy group or a methoxycarbonyl group. However, the carboxy group may form a salt with an alkali metal. R ²⁵ each independently represents a carboxy group, a sulfo group, a nitro group, an amino group or a hydroxy group. However, the carboxy group or the sulfo group may form a salt with the alkali metal.

  Specific examples of the compound represented by the above formula include the following compounds.

  Moreover, as a polymerizable monomer which has the said azobenzene skeleton as a side chain, the compound represented by a following formula can be mentioned, for example.

In the above formula, each R ³¹ is independently (meth) acryloyloxy group, (meth) acrylamide group, vinyloxy group, vinyloxycarbonyl group, vinyliminocarbonyl group, vinyliminocarbonyloxy group, vinyl group, isopropenyloxy. Represents a group, isopropenyloxycarbonyl group, isopropenyliminocarbonyl group, isopropenyliminocarbonyloxy group, isopropenyl group or epoxy group. R ³² is _{^{- (A 31 -B 31 -A 31}} ) m - (D 31) n - represents a linking group represented ^{by, R 33} is _{^{(D 31) n - (A}} 31 -B 31 -A 31) _m represents a linking group represented by-. Here, A ³¹ represents a divalent hydrocarbon group, B ³¹ represents —O—, —COO—, —OCO—, —CONH—, —NHCO—, —NHCOO— or —OCONH—, and m represents Represents an integer of 0 to 3; D ³¹ represents a divalent hydrocarbon group when m is 0, and —O—, —COO—, —OCO—, —CONH—, —NHCO—, —NHCOO— when m is an integer of 1 to 3. Alternatively, -OCONH- is represented, and n represents 0 or 1. R ³⁴ each independently represents a halogen atom, a carboxy group, a halogenated methyl group, a halogenated methoxy group, a cyano group, a nitro group, a methoxy group or a methoxycarbonyl group. However, the carboxy group may form a salt with an alkali metal. Each R ³⁵ independently represents a carboxy group, a sulfo group, a nitro group, an amino group or a hydroxy group. However, the carboxy group or the sulfo group may form a salt with the alkali metal.

  Specific examples of the compound represented by the above formula include the following compounds.

  In the present invention, various cis-trans isomerization reactive skeletons and substituents can be selected from the photoisomerization reactive compounds according to required characteristics. Moreover, the said photoisomerization reaction compound can also be used individually by 1 type or in combination of 2 or more types.

  The photoisomerization type material used in the present invention may contain additives in addition to the photoisomerization reactive compound as long as the optical alignment property of the photoalignment film is not hindered. When a polymerizable monomer is used as the photoisomerization reactive compound, examples of the additive include a polymerization initiator and a polymerization inhibitor.

  The polymerization initiator or polymerization inhibitor may be appropriately selected from generally known compounds according to the type of photoisomerization reactive compound. The addition amount of the polymerization initiator or the polymerization inhibitor is preferably in the range of 0.001% by weight to 20% by weight, and in the range of 0.1% by weight to 5% by weight with respect to the photoisomerization reactive compound. More preferably, it is within.

Formation of the photo-alignment film when such a photoisomerization type material is used can be performed by the same method as that when the photoreaction type material is used. In this case, in the coating liquid, The content of the photoisomerization reactive compound is preferably in the range of 0.05% by weight to 10% by weight, and more preferably in the range of 0.2% by weight to 5% by weight.
In the case of the photoisomerization type, photo-alignment treatment can also be performed by irradiating non-polarized ultraviolet oblique. The light irradiation direction is not particularly limited as long as it can cause the above-described photoexcitation reaction. However, since the alignment state of the ferroelectric liquid crystal can be made favorable, The angle is preferably within the range of 10 ° to 45 °, more preferably within the range of 30 ° to 45 °, and most preferably 45 °.
Further, when the polymerizable monomer as described above is used as the photoisomerization reactive compound, it is polymerized by heating after the photo-alignment treatment, and the anisotropy imparted to the photo-alignment film is increased. Can be stabilized.

b. Polarizing plate As described above, a polarizing plate is used for the second alignment substrate. The polarizing plate is arranged so that the normal direction of the plate-like molecule constituting the columnar alignment layer of the first alignment substrate is perpendicular to the polarization direction. The polarizing plate is not particularly limited as long as it transmits only a specific direction among the wave of light, and generally known polarizing plates for liquid crystal display elements can be used.

(3) Liquid Crystal Layer Next, the liquid crystal layer used in the present invention will be described. The liquid crystal layer used in the present invention is configured by filling a ferroelectric liquid crystal between the first alignment substrate and the second alignment substrate.

(Ferroelectric liquid crystal)
The ferroelectric liquid crystal used in the liquid crystal layer is not particularly limited as long as it exhibits a chiral smectic C (SmC ^* ) phase. In the temperature lowering process, a cholesteric (Ch) phase-smectic A (SmA) is used. ) Phase-chiral smectic C (SmC ^* ) phase and a material that changes phase can be used, and a material that changes phase with Ch-SmC ^* phase and does not pass through the SmA phase can also be used. Among them, the ferroelectric liquid crystal used in the present invention preferably exhibits a phase transition series that does not pass through the latter SmA phase. Ferroelectric liquid crystals exhibiting such a phase transition series tend to exhibit monostable driving characteristics, and by using a material exhibiting monostable driving characteristics in this way, gradation display becomes possible. This is because it becomes easy to obtain a liquid crystal display element with high-definition color display.

  When the liquid crystal display element of the present invention is driven by the field sequential color method, the ferroelectric liquid crystal is a positive or negative voltage among the ferroelectric liquid crystals exhibiting monostable driving characteristics as described above. It is preferable to use a ferroelectric liquid crystal that is driven by half V-shape, in which the liquid crystal molecules operate only when the voltage is applied. This is because by using the ferroelectric liquid crystal having such characteristics, the opening time of the black-and-white shutter can be increased, and a bright color liquid crystal display element can be obtained.

Further, the ferroelectric liquid crystal used in the present invention preferably constitutes a single phase. The term “single phase” as used herein means that a polymer network is not formed as in the polymer stabilization method. Thus, by using a single-phase ferroelectric liquid crystal, the manufacturing process is facilitated and the driving voltage can be lowered.
As will be described later, a polymer network may be formed in the liquid crystal layer used in the present invention.

  Specific examples of such ferroelectric liquid crystal include “R2301” and “FELIX-3206” sold by AZ Electronic Materials.

(Liquid crystal layer)
The thickness of the liquid crystal layer composed of the ferroelectric liquid crystal as described above is preferably in the range of 1.2 μm to 3.0 μm, more preferably 1.3 μm to 2.5 μm, still more preferably 1. Within the range of 4 μm to 2.0 μm. This is because if the thickness of the liquid crystal layer is too thin, the contrast may be lowered. Conversely, if the thickness of the liquid crystal layer is too thick, the ferroelectric liquid crystal may be difficult to align.

  As a method for forming the liquid crystal layer, a method generally used as a method for manufacturing a liquid crystal cell can be used. For example, an isotropic liquid is formed by heating the ferroelectric liquid crystal into a liquid crystal cell prepared by previously forming an electrode on a substrate and providing the photo-alignment film, and is injected using the capillary effect. A liquid crystal layer can be formed by sealing with an adhesive. The thickness of the liquid crystal layer can be adjusted by a spacer such as beads.

  In the liquid crystal layer used in the present invention, a polymer network may be formed. That is, the liquid crystal layer may contain a polymerized polymerizable monomer. This is because the alignment of the ferroelectric liquid crystal can be further stabilized.

  The polymerizable monomer used in the polymerized product of the polymerizable monomer is not particularly limited as long as it is a compound that generates a polymer by a polymerization reaction. Examples of such a polymerizable monomer include a thermosetting resin monomer that causes a polymerization reaction by heat treatment, and an actinic radiation curable resin monomer that causes a polymerization reaction by irradiation with actinic radiation. In particular, in the present invention, it is preferable to use an actinic radiation curable resin monomer. Since the thermosetting resin monomer needs to be heated in order to cause a polymerization reaction, such a heating treatment damages the regular alignment of the ferroelectric liquid crystal or causes phase transition. There is a risk of being induced. On the other hand, the active radiation curable resin monomer does not have such a fear, and the alignment of the ferroelectric liquid crystal is rarely damaged by the polymerization reaction.

  Examples of the actinic radiation curable resin monomer include an electron beam curable resin monomer that undergoes a polymerization reaction upon irradiation with an electron beam, and a photocurable resin monomer upon irradiation with light. Among these, in the present invention, it is preferable to use a photocurable resin monomer. It is because the manufacturing method of the liquid crystal display element of this invention can be simplified by using a photocurable resin monomer.

  The photo-curable resin monomer is not particularly limited as long as it causes a polymerization reaction when irradiated with light having a wavelength in the range of 150 nm to 500 nm. In particular, in the present invention, it is preferable to use an ultraviolet curable resin monomer that undergoes a polymerization reaction when irradiated with light having a wavelength in the range of 250 nm to 450 nm, particularly in the range of 300 nm to 400 nm. This is because it has advantages in terms of the ease of the irradiation apparatus.

  The polymerizable functional group possessed by the ultraviolet curable resin monomer is not particularly limited as long as it causes a polymerization reaction when irradiated with ultraviolet rays in the wavelength region. In the present invention, it is preferable to use an ultraviolet curable resin monomer having an acrylate group.

  The UV curable resin monomer may be a monofunctional monomer having one polymerizable functional group in one molecule, or a polyfunctional monomer having two or more polymerizable functional groups in one molecule. There may be. In particular, in the present invention, it is preferable to use a polyfunctional monomer. By using a polyfunctional monomer, it becomes possible to form a stronger polymer network in the liquid crystal layer, so that the intermolecular force and the polymer network at the interface of the first alignment layer can be strengthened. Therefore, by using a polyfunctional monomer, it is possible to prevent the alignment of the ferroelectric liquid crystal from being disturbed by the temperature change of the liquid crystal layer.

  In the present invention, among the polyfunctional monomers, a bifunctional monomer having a polymerizable functional group at both ends of the molecule is preferable. By having the above functional groups at both ends of the molecule, a polymer network with a wide interval between the polymers can be formed, so that the driving voltage of the ferroelectric liquid crystal is reduced by including a polymer of a polymerizable monomer in the liquid crystal layer. It is because it can prevent.

  In the present invention, among the ultraviolet curable resin monomers, it is preferable to use an ultraviolet curable liquid crystal monomer that exhibits liquid crystallinity. The reason why such an ultraviolet curable liquid crystal monomer is preferable is as follows. That is, since the ultraviolet curable liquid crystal monomer exhibits liquid crystallinity, it can be regularly arranged by the alignment regulating force of the first alignment layer or the second alignment layer. Therefore, after the ultraviolet curable liquid crystal monomer is regularly arranged and then a polymerization reaction is caused, it can be fixed in the liquid crystal layer while maintaining the regular arrangement state. Since the polymer having such a regular alignment state is present in the liquid crystal layer, the alignment stability of the ferroelectric liquid crystal can be improved. It is because it can be made excellent in impact.

  The liquid crystal phase exhibited by the ultraviolet curable liquid crystal monomer is not particularly limited, and examples thereof include a nematic phase, an SmA phase, and an SmC phase.

  As said ultraviolet curable liquid crystal monomer used for this invention, the compound shown to a following formula can be mentioned, for example.

In the above formula, A, B, D, E and F represent benzene, cyclohexane or pyrimidine, and these may have a substituent such as halogen. A and B, or D and E may be bonded via a bonding group such as an acetylene group, a methylene group, or an ester group. M ¹ and M ² may be any of a hydrogen atom, an alkyl group having 3 to 9 carbon atoms, an alkoxycarbonyl group having 3 to 9 carbon atoms, or a cyano group. Furthermore, the acryloyloxy group at the end of the molecular chain and A or D may be bonded via a spacer such as an alkylene group having 3 to 6 carbon atoms.

  In the above formula, Y is hydrogen, alkyl having 1 to 20 carbon atoms, alkenyl having 1 to 20 carbon atoms, alkyloxy having 1 to 20 carbon atoms, alkyloxycarbonyl having 1 to 20 carbon atoms, formyl, 1 to 1 carbon atoms. It represents 20 alkylcarbonyl, C1-20 alkylcarbonyloxy, halogen, cyano or nitro.

  Among the compounds represented by the above formula, specific compounds that can be suitably used in the present invention include compounds represented by the following formula.

  The polymer of the polymerizable monomer used in the present invention may be a polymer of a single polymerizable monomer, or may be a polymer of two or more different polymerizable monomers. When it is set as the polymer of two or more different polymerizable monomers, the polymer of the said ultraviolet curable liquid crystal monomer and another ultraviolet curable resin monomer can be illustrated, for example.

  When the above-mentioned UV curable liquid crystal monomer is used as the polymerizable monomer, the polymer of the polymerizable monomer used in the present invention has a main chain exhibiting liquid crystallinity by having an atomic group exhibiting liquid crystallinity in the main chain. It may be a chain liquid crystal polymer, or may be a side chain liquid crystal polymer in which the side chain exhibits liquid crystallinity by having an atomic group exhibiting liquid crystallinity in the side chain. Among these, in the present invention, a side chain liquid crystal polymer is preferable. This is because the presence of an atomic group exhibiting liquid crystallinity in the side chain increases the degree of freedom of the atomic group, so that the atomic group exhibiting liquid crystallinity is easily aligned in the liquid crystal layer. Further, as a result, the alignment stability of the ferroelectric liquid crystal in the liquid crystal layer can be improved.

The amount of the polymerized polymerizable monomer in the liquid crystal layer is not particularly limited as long as it is within a range in which the alignment stability of the ferroelectric liquid crystal can be set to a desired level, but usually 0.5% in the liquid crystal layer. The mass is preferably in the range of 30% by mass to 30% by mass, particularly preferably in the range of 1% by mass to 20% by mass, and particularly preferably in the range of 1% by mass to 10% by mass. This is because if it exceeds the above range, the driving voltage of the ferroelectric liquid crystal may increase or the response speed may decrease. On the other hand, if the amount is less than the above range, the alignment stability of the ferroelectric liquid crystal becomes insufficient, and the heat resistance and impact resistance of the liquid crystal display element of the present invention may be impaired.
Here, the abundance of the polymerizable monomer polymer in the liquid crystal layer is determined by measuring the weight of the remaining polymerizable monomer polymer with an electronic balance after washing the monomolecular liquid crystal in the liquid crystal layer with a solvent. It can be calculated from the obtained remaining amount and the total mass of the liquid crystal layer.

  The liquid crystal layer used in the present invention may contain other compounds as long as the object of the present invention is not impaired. Examples of such other compounds include unreacted polymerizable monomers, photopolymerization initiators, reaction initiators, and reaction inhibitors.

(4) Manufacturing method of liquid crystal display element Next, the manufacturing method of the liquid crystal display element of this invention is demonstrated. As a manufacturing method of the liquid crystal display element of the present invention, a known method can be generally used as a manufacturing method of the liquid crystal display element, and it is not particularly limited.

  As an example of the manufacturing method of the liquid crystal display element of the present invention, a case where an active matrix type liquid crystal display element using a TFT element is used will be described as an example.

First, a transparent conductive film is formed on the first substrate by the above-described vapor deposition method to form a common electrode on the entire surface. On the other hand, an x electrode and a y electrode are formed on the second substrate by patterning a conductive film in a matrix, and a switching element and a pixel electrode are provided.
As described above, the columnar alignment layer or the second alignment layer is formed on the electrode layers formed on the first substrate and the second substrate in this manner. Beads are dispersed as spacers on one surface of the formed columnar alignment layer and the second alignment layer, and a sealant is applied to the other on the other, and the first alignment substrate and the second alignment substrate are connected to the first alignment substrate. The columnar alignment layer and the second alignment layer of the second alignment substrate are bonded together so as to face each other and thermocompression-bonded. After thermocompression bonding, the ferroelectric liquid crystal is heated from the injection port using the capillary effect and injected in an isotropic or nematic phase, and the injection port is sealed with an ultraviolet curable resin or the like. Thereafter, the ferroelectric liquid crystal is aligned by slow cooling to obtain the liquid crystal display element of the present invention.

  In the present invention, a liquid crystal display element can be manufactured using a polymer stabilization method. In this case, a liquid crystal sealing step of sealing a liquid crystal layer forming composition containing a ferroelectric liquid crystal and a polymerizable monomer between the first alignment substrate and the second alignment substrate, and the ferroelectric liquid crystal in a chiral smectic C phase state The liquid crystal layer can be formed by the liquid crystal alignment step and the polymerization step of polymerizing the polymerizable monomer in the state where the ferroelectric liquid crystal is in the chiral smectic C phase.

In the liquid crystal encapsulating step, the method for encapsulating the liquid crystal layer forming composition containing the ferroelectric liquid crystal and the polymerizable monomer is not particularly limited. For example, the ferroelectric liquid crystal in the composition for forming a liquid crystal layer is heated by heating the composition for forming a liquid crystal layer in a liquid crystal cell prepared using the first alignment substrate and the second alignment substrate in advance. And can be sealed by injecting from the inlet using the capillary effect. In this case, the inlet is sealed with an adhesive.
At this time, the amount of the polymerizable monomer contained in the composition for forming a liquid crystal layer may be arbitrarily determined according to the amount necessary for stabilizing the alignment of the ferroelectric liquid crystal after the liquid crystal layer is formed. . Especially in this invention, the inside of the range of 0.5 mass%-30 mass% is preferable in the composition for liquid-crystal layer formation, Especially the inside of the range of 1 mass%-20 mass% is preferable, and 1 mass%-10 especially Within the range of mass% is preferable. This is because if the content of the polymerizable monomer is larger than the above range, the driving voltage of the ferroelectric liquid crystal becomes high after the liquid crystal layer is formed, which may impair the performance of the liquid crystal display element. On the other hand, if it is lower than the above range, the alignment stability of the ferroelectric liquid crystal becomes insufficient, and as a result, the heat resistance, impact resistance, etc. of the liquid crystal display element may be lowered.
Further, when the composition for forming a liquid crystal layer is encapsulated, the ferroelectric liquid crystal is heated to a temperature higher than the transition temperature from the chiral smectic C phase to the nematic phase. The temperature may be equal to or higher than the transition temperature from the chiral smectic C phase to the nematic phase, but usually the ferroelectric liquid crystal is heated so as to be in an isotropic phase or a nematic phase. The specific temperature differs depending on the type of ferroelectric liquid crystal and is appropriately selected.

  Next, in the liquid crystal alignment step, the encapsulated ferroelectric liquid crystal is cooled. At this time, the ferroelectric liquid crystal is usually gradually cooled to room temperature (about 25 ° C.).

In the polymerization step, the method for polymerizing the polymerizable monomer may be arbitrarily determined according to the type of the polymerizable monomer. For example, when an ultraviolet curable resin monomer is used as the polymerizable monomer, ultraviolet It can be polymerized by irradiation.
Such polymerization of the polymerizable monomer may be performed with a voltage applied to the liquid crystal layer or may be performed without applying a voltage, but in the present invention, it is performed with no voltage applied to the liquid crystal layer. It is preferable. This is because the production process is further simplified by polymerization in the state where no voltage is applied.

(5) Liquid crystal display element Since the liquid crystal display element of the present invention thus obtained uses a columnar alignment layer having an alignment function and a polarization function as the first alignment layer, a polarizing plate is provided on the first alignment layer side. Can be visualized without using the light, and the scattering of light generated at the interface between the liquid crystal display element and the polarizing plate can be eliminated and the decrease in light transmittance can be suppressed. In addition, since it is not necessary to use a polarizing plate on the first alignment layer side as described above, the liquid crystal display element of the present invention is reduced in thickness and weight, and such a liquid crystal display element reduces manufacturing costs. It also leads to. Since the columnar alignment layer used in the liquid crystal display element of the present invention is formed by utilizing the self-organization of the plate-like molecules, it is simple without requiring alignment treatment such as rubbing treatment or photo-alignment treatment. Therefore, it can be said that the liquid crystal display element of the present invention is highly practical.

  Such a liquid crystal display element of the present invention can align ferroelectric liquid crystal without causing alignment defects such as double domains, enables gradation display, and is used as a high-definition color liquid crystal display element. You can also.

  In particular, the liquid crystal display element of the present invention is suitable as a color liquid crystal display element by adopting a color filter system or a field sequential color system. Among them, the liquid crystal display element of the present invention is preferably driven by a field sequential color method. This field sequential color system enables color display without using a color filter by turning on and off the liquid crystal in synchronization with the blinking of the three colors of red, green, and blue. This is because it is possible to realize a bright and high-definition color moving image display with a wide viewing angle at a low cost. In addition, by using a half-V-driven material in which liquid crystal molecules operate only when a positive or negative voltage is applied as a ferroelectric liquid crystal, light leakage during dark portion operation (when the black and white shutter is closed) is reduced. This is because the opening time as a black-and-white shutter can be made sufficiently long, whereby each color that is temporally switched can be displayed brighter, and a bright color liquid crystal display element can be obtained.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has the same configuration as the technical idea described in the claims of the present invention. It is included in the technical scope of the invention.

Hereinafter, the present invention will be described more specifically with reference to examples.
[Example 1]
The following compound 1 was used as the photodimerization reactive compound.

(Preparation of first alignment substrate)
An ink containing plate molecules having photodichroism in the visible light region (Optiva, N015) was applied on a well-cleaned glass substrate with an ITO electrode using a die coater and dried. It was immersed in a 1% barium chloride aqueous solution for about 1 second. Further, it was washed and dried again to obtain a first alignment substrate having a columnar alignment layer having a thickness of 0.3 μm.

(Production of second alignment substrate)
A solution prepared by dissolving the compound 1 in cyclopentanone so as to have a concentration of 2% by weight was spin-coated at 4000 rpm for 30 seconds on a well-cleaned ITO film of a glass substrate with an ITO electrode. After drying, 200 mJ / cm ² non-polarized ultraviolet rays were irradiated from the glass substrate side to form a photo-alignment film to obtain a second alignment substrate.

(Formation of liquid crystal layer)
A bead spacer having a diameter of 1.5 μm is dispersed on the columnar alignment layer of the first alignment substrate, a sealant is applied on the photo-alignment film of the second alignment substrate using a seal dispenser, and the columner of the first alignment substrate is applied. The first alignment substrate and the second alignment substrate are arranged so that the polarization direction of the alignment layer and the alignment direction of the photo-alignment film of the second alignment substrate are the same, and the columnar alignment layer and the photo-alignment film face each other. And pasted together. Thermocompression bonding was performed at 150 ° C. for about 1 hour to prepare a test cell. When ferroelectric liquid crystal (manufactured by AZ Electronic Materials, R2301) was injected into this test cell under a temperature condition of about 100 ° C. and gradually cooled, uniform monodomain alignment was obtained.

[Example 2]
(Formation of recess pattern)
A UV-curable acrylate resin having the following composition was spin-coated on a well-cleaned glass substrate with an ITO electrode, and an original plate having irregularities formed thereon by an electron beam drawing method was placed thereon, and a weight of 100 kg / cm ² was applied for 1 minute. . In this state, the ultraviolet light 100 mJ / cm ² was irradiated, after further stripping the original, ultraviolet light 3000 mJ / cm ² was irradiated, width 0.2 [mu] m, pitch 0.4 .mu.m, the recess pattern of depth 0.2 [mu] m Formed. The surface was hydrophilized by adding a plasma treatment thereto.

(Composition of UV curable acrylate resin)
・ Goserac UV-7500B (manufactured by Nippon Kayaku Co., Ltd.) 40 parts by weight ・ 1,6-hexanediol acrylate (manufactured by Nippon Kayaku Co., Ltd.) 35 parts by weight ・ Pentaerythritol acrylate (manufactured by Toagosei Co., Ltd.) 21 parts by weight -Hydroxycyclohexyl phenyl ketone (Ciba Specialty Chemicals) 2 parts by weight-Benzophenone (Nippon Kayaku Co., Ltd.) 2 parts by weight

(Preparation of first alignment substrate with concave pattern)
On the concave pattern produced by the above method, an ink containing plate molecules having photodichroism in the visible light region (manufactured by Optiva, N015) was applied using an inkjet, and after drying, a 15% barium chloride aqueous solution For about 1 second. Further, it was washed and dried again to obtain a first alignment substrate having a columnar alignment layer having a thickness of 0.3 μm at the portion where the column structure is formed.

(Formation of liquid crystal layer)
A bead spacer having a diameter of 1.5 μm is dispersed on the columnar alignment layer of the first alignment substrate with the concave pattern, and the second alignment substrate prepared in Example 1 is used to seal on the photo-alignment film of the second alignment substrate. The sealant is applied using a dispenser so that the polarization direction of the columnar alignment layer of the first alignment substrate is the same as the alignment direction of the photoalignment film of the second alignment substrate, and the columnar alignment layer and the photoalignment film are The first alignment substrate and the second alignment substrate were arranged and bonded so as to face each other. Thermocompression bonding was performed at 150 ° C. for about 1 hour to prepare a test cell. When ferroelectric liquid crystal (manufactured by AZ Electronic Materials, R2301) was injected into this test cell under a temperature condition of about 100 ° C. and gradually cooled, uniform monodomain alignment was obtained.

[Example 3]
A test cell was produced under the same conditions as in Example 1. A liquid crystal prepared by mixing 5% by mass of a polymerizable monomer (manufactured by Dainippon Ink & Chemicals, Inc., UCL-001) with a ferroelectric liquid crystal (manufactured by AZ Electronic Materials, R2301) was added to the test cell at about 100 ° C. The mixture was poured and slowly cooled. Thereafter, non-polarized ultraviolet rays were exposed to about 1000 mJ / cm ² to polymerize the polymerizable monomer. In the liquid crystal display device thus obtained, uniform alignment of monodomains was obtained.

It is a schematic sectional drawing which shows an example of the liquid crystal display element of this invention. It is a figure explaining the column structure of the plate-like molecule | numerator and columnar alignment layer which are used for this invention. It is a schematic perspective view which shows an example of the liquid crystal display element of this invention. It is a schematic sectional drawing which shows an example of the liquid crystal display element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a ... 1st base material 1b ... 2nd base material 2a ... 1st electrode layer 2b ... 2nd electrode layer 2c ... x electrode 2d ... y electrode 2e ... Pixel electrode 3a ... 1st orientation layer 3b ... 2nd orientation layer 4b ... Polarizing plate 5 ... Liquid crystal layer 7 ... TFT element 11 ... First alignment substrate 12 ... Second alignment substrate a ... Plate-like molecule b ... Column structure n ... Normal direction

Claims (7)

A first alignment substrate having a first substrate, a first electrode layer formed on the first substrate, and a first alignment layer formed on the first electrode layer, and a second substrate A second alignment substrate comprising: a second electrode layer formed on the second substrate; and a second alignment layer formed on the second electrode layer; and the first alignment layer and the second alignment layer. A liquid crystal display element, which is disposed so as to face an alignment layer, and has a ferroelectric liquid crystal sandwiched between the first alignment substrate and the second alignment substrate,
The first alignment layer has a column structure in which plate-like molecules having photodichroism in the visible light region are stacked with the normal direction of the plate-like molecules facing a certain direction, and has an alignment function and a polarization function. A columnar alignment layer having
Liquid crystal display elements you wherein the second alignment layer is a photo alignment layer. The columnar alignment layer has a resin layer in which concave portions or convex portions having a predetermined width are formed in a pattern on the surface, and the column structure formed along the concave portions of the resin layer. The liquid crystal display element according to claim 1. The liquid crystal display element according to claim 1, wherein the plate-like molecule exhibits a lyotropic liquid crystal phase in an aqueous solution. The liquid crystal display element according to any one of claims 1 to 3, wherein the ferroelectric liquid crystal exhibits monostable driving characteristics. The ferroelectric liquid crystal, the liquid crystal display device according to any one of claims of claims 1 to 4, characterized in that indicate the phase transition series which does not pass through the smectic A phase in the cooling process. 6. The liquid crystal display element according to claim 1, wherein the first electrode layer or the second electrode layer includes a thin film transistor and is driven by an active matrix. 7. The liquid crystal display device according to any one of claims of claims 1 to 6, characterized in that for driving the field sequential color scheme.

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