JP4679972B2 - Liquid crystal display element and manufacturing method thereof - Google Patents

Description

  The present invention relates to a liquid crystal display element using a ferroelectric liquid crystal and a manufacturing method thereof.

  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, the ferroelectric liquid crystal (FLC) is a liquid crystal 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 mono-stabilizing the ferroelectric liquid crystal, an ultraviolet curable monomer is added to the liquid crystal material, injected into the cell, and then irradiated with ultraviolet light while applying an alternating current or direct current voltage to cure and align the liquid crystal. Polymer stabilization methods for stabilizing are known. In addition, the ferroelectric liquid crystal that does not have a smectic A phase in the phase series and directly undergoes a phase transition from a nematic phase to a chiral smectic C phase in the temperature lowering process is raised to a temperature higher than the cholesteric phase-nematic phase transition point. Then, a method of mono-stabilizing the ferroelectric liquid crystal by slow cooling is known.

  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 general, techniques for aligning liquid crystals include a rubbing method and a photo-alignment method. 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.

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 in a liquid crystal display element using a ferroelectric liquid crystal, a ferroelectric liquid crystal can be obtained by a simple method without requiring an alignment treatment such as a rubbing treatment or a photo-alignment treatment. The main object is to provide a liquid crystal display element capable of controlling the orientation of the liquid crystal.

  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 as an alignment layer for controlling the alignment of ferroelectric liquid crystal, thereby providing alignment such as rubbing treatment and photo-alignment treatment. It has been found that the alignment of the ferroelectric liquid crystal can be controlled by a simple method without performing the treatment, 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 layer and the second alignment layer;
At least one of the first alignment layer and the second alignment layer is a columnar alignment layer having a column structure in which plate-like molecules are stacked with the normal direction of the plate-like molecules facing a certain direction of the substrate. The liquid crystal display element characterized by the above is provided.

  The liquid crystal display element of the present invention is configured by stacking at least one of a first alignment layer and a second alignment layer provided in order to control the alignment of a ferroelectric liquid crystal in a certain direction. By using a columnar alignment layer having a column structure, the ferroelectric liquid crystal can be aligned by a simple method without requiring a rubbing process or a photo-alignment process.

  In such a liquid crystal display element of the present invention, the first alignment layer and the second alignment layer are the columnar alignment layers, and the normal direction of the plate-like molecules of the first alignment layer and the second alignment layer It is preferable that the normal directions of the plate-like molecules are arranged substantially parallel to each other, and the constituent materials of the first alignment layer and the second alignment layer have different compositions. In the present invention, by using the first alignment layer and the second alignment layer as columnar alignment layers, the ferroelectric liquid crystal can be aligned by a simple method, but the first alignment layer and the second alignment layer are further provided. This is because by making the constituent materials of the layers different from each other, alignment defects are hardly generated and the alignment stability of the ferroelectric liquid crystal is excellent. In particular, when a ferroelectric liquid crystal exhibiting a phase transition series that does not pass through a smectic A phase (SmA) is used, generation of double domains can be suppressed.

  In another aspect of the liquid crystal display element of the present invention, the first alignment layer and the second alignment layer are the columnar alignment layers, and the normal direction of the plate-like molecules of the first alignment layer and the first alignment layer A reaction in which the normal direction of the plate-like molecules of the two-alignment layer is arranged substantially perpendicularly and contains a polymerizable liquid crystal material on the opposite surface of the first alignment layer or the second alignment layer and exhibits a nematic phase. It is possible to have a reactive liquid crystal layer formed by fixing a functional liquid crystal. In this way, the first alignment layer and the second alignment layer are columnar alignment layers, which are arranged substantially vertically, and the above-mentioned reactive liquid crystal layer is provided on the opposite surface of one alignment layer, thereby aligning as described above. The ferroelectric liquid crystal can be aligned by a simple method without causing defects.

  Furthermore, as another aspect of the liquid crystal display element of the present invention, the first alignment layer may be the columnar alignment layer, and the second alignment layer may be a photo-alignment film. As described above, one of the first alignment layer and the second alignment layer is a columnar alignment layer, and the other alignment layer is a photo-alignment film, thereby reducing the number of alignment processing steps as described above. The ferroelectric liquid crystal can be aligned without causing alignment defects.

  As a constituent material of such a photo-alignment film, a photo-reactive material that imparts anisotropy to the photo-alignment film by causing a photoreaction or an anisotropic to the photo-alignment film by causing a photoisomerization reaction It is preferable that the material is a photoisomerization reaction type material that imparts properties. This is because anisotropy can be easily imparted to the photo-alignment film by using these materials.

  In such a liquid crystal display element of the present invention, the columnar alignment layer is formed along a resin layer in which concave portions or convex portions having a predetermined width are formed on the surface, and along the concave portions of the resin layer. It may have the above column structure. This is because the column structure can be easily arranged in a certain direction by forming the column structure along the concave portion of the resin layer.

  Moreover, it is preferable that the plate-like molecule constituting such a columnar alignment layer exhibits a lyotropic liquid crystal phase in an aqueous solution. 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. Moreover, it is because the immobilization process for immobilizing the column structure is facilitated because the plate-like molecules are water-soluble.

  In such a liquid crystal display device of the present 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.

  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.

  Such a liquid crystal display element of the present invention preferably has a thin film transistor (TFT element) in the first electrode layer or the second electrode layer 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.

  The liquid crystal display element of the present invention is also suitable for being 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. Bright, high-definition color video display with wide corners can be obtained.

  The present invention is also a method for producing the liquid crystal display element, wherein in the formation of the columnar alignment layer, a coating film forming step of forming a coating film by applying a coating liquid for forming a columnar alignment layer on a substrate. And a method for producing a liquid crystal display element, comprising: a drying step for drying the coating film; and a fixing treatment step for hydrophobizing and fixing the dried coating film. .

  According to such a production method of the present invention, the orientation of the ferroelectric liquid crystal can be controlled without applying an alignment treatment by applying a columnar alignment layer forming coating solution and performing a simple post-treatment. The liquid crystal display element which can be manufactured can be manufactured easily. Further, by providing the immobilization treatment step in this manner, a column structure made of plate-like molecules is immobilized, and a liquid crystal display element excellent in the alignment stability of the ferroelectric liquid crystal can be obtained.

  According to the present invention, as an alignment layer for controlling the alignment of the ferroelectric liquid crystal, a columnar alignment layer having a column structure in which plate molecules are stacked with the normal direction of the plate molecules facing a certain direction of the substrate is provided. By using it, the ferroelectric liquid crystal can be aligned by a simple method without requiring alignment treatment such as rubbing treatment or photo-alignment treatment.

  The present invention provides a liquid crystal display element and a method for manufacturing the same. Hereinafter, the liquid crystal display element of the present invention and the manufacturing method thereof will be described.

A. Liquid Crystal Display Element First, 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 device, 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 layer and the second alignment layer,
At least one of the first alignment layer and the second alignment layer is a columnar alignment layer having a column structure in which plate-like molecules are stacked with the normal direction of the plate-like molecules facing a certain direction of the substrate. It is characterized by.

  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. 1A, in the liquid crystal display element of the present invention, a first base material 1a, a first electrode layer 2a formed on the first base material 1a, and the first electrode layer 2a. A first alignment substrate 11 having a first alignment layer 3a formed thereon is formed, a second substrate 1b, a second electrode layer 2b formed on the second substrate 1b, A second alignment substrate 12 having a second alignment layer 3b formed on the second electrode layer 2b is formed. The first alignment substrate 11 and the second alignment substrate 12 are formed of the first alignment layer 3a. And the second alignment layer 3b are arranged to face each other. In addition, a ferroelectric liquid crystal is sandwiched between the first alignment layer 3a and the second alignment layer 3b to form the liquid crystal layer 5.

  In such a liquid crystal display element of the present invention, at least one of the first alignment layer and the second alignment layer is a columnar alignment layer. FIG. 2A is a diagram showing a model structure and normal direction of a plate-like molecule used in the present invention, and FIG. 2B is a schematic perspective view of a columnar alignment layer used in the present invention. . As shown in FIG. 2 (b), in this columnar alignment layer, the plate-like molecules a are along the concave portions of the resin layer c in which concave portions or convex portions having a predetermined width are formed in a pattern on the surface. A column structure b is formed by stacking the normal direction n of the plate-like molecules a in a certain direction of the substrate, and a plurality of such 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 direction of the columns of the plurality of column structures b included in the columnar alignment layer is a certain direction of the substrate. The orientation of the ferroelectric liquid crystal is controlled by the interaction between the column structure b and the ferroelectric liquid crystal.

  In the liquid crystal display element of the present invention, by using at least one of the first alignment layer and the second alignment layer as a columnar alignment layer, an alignment process such as a rubbing process or a photo-alignment process is not required. It is possible to align the ferroelectric liquid crystal by various methods.

  Such a liquid crystal display element of the present invention may have other layers for the purpose of enhancing the alignment control ability and the adhesiveness between the respective layers. For example, as shown in FIG. 1B, a reactive liquid crystal layer 6 including a polymerizable liquid crystal material and having a reactive liquid crystal exhibiting a nematic phase fixed thereon is formed on the second alignment layer 3b. You can also. Since such a reactive liquid crystal layer 6 is fixed on the second alignment layer, anisotropy is imparted to the reactive liquid crystal layer by the second alignment layer, thereby causing ferroelectricity. It functions as an alignment film for aligning the crystalline liquid crystal.

  Further, polarizing plates 4a and 4b may be provided outside the base materials 1a and 1b, so that only incident light becomes linearly polarized light and is polarized in the alignment direction of the liquid crystal molecules. For example, when the ferroelectric liquid crystal constituting the liquid crystal layer 5 exhibits monostable drive characteristics, gradation display is possible by controlling the amount of transmitted light by the applied voltage.

  In such a liquid crystal display element of the present invention, for example, as shown in FIGS. 4 and 5, one substrate is a TFT substrate in which thin film transistors (TFT elements) are arranged in a matrix, and the other substrate has a common electrode in the entire region. It is preferable that the common electrode substrates formed in the above are combined to drive the active matrix. As described above, since the liquid crystal display element of the present invention is driven in 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. 4 is a schematic perspective view showing an example of the liquid crystal display element of the present invention, and FIG. 5 is a schematic cross-sectional view thereof. In FIG. 4, the first electrode layer 2a is a common electrode substrate in one substrate, and the second electrode layer 2b in the counter substrate is an x electrode 2c, a y electrode 2d, and a pixel electrode 2e. This 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. ing. 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.

  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.

  The liquid crystal display element of the present invention is not particularly limited as long as it has the above-described configuration, but as a preferred embodiment, the first alignment layer and the second alignment layer are the columnar alignment layers. The normal direction of the plate-like molecules of the first alignment layer and the normal direction of the plate-like molecules of the second alignment layer are arranged substantially in parallel, and the constituent materials of the first alignment layer and the second alignment layer Having the composition different from each other, the first alignment layer and the second alignment layer are the columnar alignment layer, and the plate-like molecules of the first alignment layer The normal direction and the normal direction of the plate-like molecules of the second alignment layer are arranged substantially perpendicularly, and a polymerizable liquid crystal material is included on the opposing surface of the first alignment layer or the second alignment layer, and Reactive liquid crystal layer formed by fixing a reactive liquid crystal exhibiting a nematic phase And a third aspect characterized in that the first alignment layer is the columnar alignment layer, and the second alignment layer is a photo-alignment film. Can be mentioned. Hereinafter, each aspect will be described in detail.

1. First Aspect First, a first aspect of the liquid crystal display element of the present invention will be described. In the liquid crystal display element of the first aspect, the first alignment layer and the second alignment layer are the columnar alignment layers, the normal direction of the plate-like molecules of the first alignment layer, and the plate of the second alignment layer The normal direction of the molecular molecules is arranged substantially parallel to each other, and the constituent materials of the first alignment layer and the second alignment layer have different compositions from each other.

  The liquid crystal display element according to the first aspect will be described below. FIG. 1A shows an example of the liquid crystal display element according to the first aspect of the present invention. In the drawing, the first alignment layer 3a and the second alignment layer 3b are the columnar alignment layers. In this embodiment, the first alignment layer and the second alignment layer are formed as the columnar alignment layer as described above, and the ferroelectric liquid crystal is aligned by a simple method without requiring a rubbing process or a photo-alignment process. It is.

  As shown in FIG. 3A, the first alignment layer and the second alignment layer are composed of the normal direction of the plate-like molecule of the first alignment layer 3a and the normal line of the plate-like molecule of the second alignment layer 3b. It arrange | positions so that a direction may become substantially parallel. Here, “substantially parallel” means that the angle θ formed by the normal direction of the plate-like molecules of the first alignment layer 3a and the normal direction of the plate-like molecules of the second alignment layer 3b is 0 ° to 5 °. It means to be within the range. This angle θ is preferably in the range of 0 ° to 1 °. This is because as the angle θ decreases, the alignment ability of the columnar alignment layer increases, and the alignment of the ferroelectric liquid crystal can be effectively controlled.

  Furthermore, the constituent materials of the first alignment layer and the second alignment layer may be the same or different from each other, but in this embodiment, the constituent materials of the first alignment layer and the second alignment layer are The compositions are different from each other. This is because by changing the composition of the constituent materials of the first alignment layer and the second alignment layer in this manner, the interaction between these alignment layers and the ferroelectric liquid crystal is strengthened, and alignment defects are less likely to occur. In particular, when a ferroelectric liquid crystal exhibiting a phase transition series that does not pass through a smectic A phase (SmA) is used, generation of double domains can be suppressed, so that it is possible to obtain monodomain alignment of the ferroelectric liquid crystal. I have to. Hereinafter, each component and manufacturing method of this aspect will be described.

(1) Each component a. First alignment layer and second alignment layer First, the first alignment layer and the second alignment layer used in the liquid crystal display element of the first aspect of the present invention will be described.

  In the first aspect, the first alignment layer and the second alignment layer have a columnar structure in which the first alignment layer and the second alignment layer have alignment ability and the normal direction of the plate molecule is directed to a certain direction of the substrate. The constituent materials of the columnar alignment layer used for the first alignment layer and the second alignment layer have different compositions from each other.

  The columnar alignment layer used in this embodiment has a column structure in which the normal direction of the plate molecules is stacked so as to face a certain direction of the substrate, and the column structure composed of the plate molecules and the ferroelectric liquid crystal The ferroelectric liquid crystal is aligned by the interaction. Such a columnar alignment layer has an alignment ability to control the alignment of the ferroelectric liquid crystal without performing an alignment process such as a rubbing process or a photo-alignment process, has a simple manufacturing process, and an apparatus cost. It has the advantage that it does not start.

  Such a columnar alignment layer is not particularly limited as long as it has alignment ability and has the above column structure, and may be a single layer in which the column structure is formed. The resin layer may have a concave or convex portion having a predetermined width on the surface, and a column structure made of plate-like molecules formed along the concave portion of the resin layer. . For example, when the columnar alignment layer has a resin layer and a column structure, the column structure is formed along the recess of the resin layer, so that the column structure can be easily arranged in a certain direction. Have Thus, the columnar alignment layer may be one in which a column structure made of plate-like molecules is formed on a resin layer having a concave or convex pattern. On the other hand, when the columnar alignment layer is a single layer in which the column structure is formed, it is easy to align the column structure in a certain direction by applying the columnar alignment layer forming coating solution by, for example, a method in which shear stress is applied. The columnar alignment layer can be more easily formed. Hereinafter, the column structure and the resin layer will be described.

(Column structure)
First, the column structure constituting the columnar alignment layer will be described. The column structure used in this embodiment is formed on the concave or convex pattern of the resin layer, and this column structure has a plate-like molecule whose normal direction is directed to a certain direction of the substrate. It is configured by stacking.

  Here, the “plate-like molecule” refers to a molecule having at least a plurality of aromatic ring structures and a molecular core portion arranged in a plane.

  The plate-like molecule used in this embodiment is not particularly limited as long as it can form 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. A plate-like molecule having 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. Among these, a sulfonic acid-based hydrophilic group is preferable.

  Here, it can be confirmed that the plate-like molecules form a column structure by measuring the columnar alignment layer using an X-ray diffractometer.

  Among the above, the plate-like molecules used in this embodiment preferably form a 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.

  In this embodiment, it is particularly preferable to use a plate-like molecule 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.

  Such a plate-like molecule may or may not have dichroism. For example, when a plate-like molecule having no dichroism is used, there is an advantage that it is not necessary to consider the arrangement with a polarizing plate because the obtained columnar alignment layer does not have polarizing ability. On the other hand, when a dichroic material is used as the plate-like molecule, the polarization direction of the polarizing plate and the normal direction of the plate-like molecule may be arranged substantially in parallel. This is because the polarizing function of the polarizing plate is not hindered due to the polarizing ability of the columnar alignment layer.

  Specific examples of the plate-like molecule that forms a column structure in the aqueous solution as described above, exhibits a lyotropic liquid crystal phase, and has dichroism include a substance 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.

  As the dichroic molecule having dichroism used in this embodiment, among the above substances, substances represented by the above chemical formulas I to V are preferably used.

  Furthermore, examples of the material containing a plate-like molecule having dichroism include “N015” and “Y105” 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.

  The above substances can be used alone or in combination of two or more. In this embodiment, the first alignment layer and the second alignment layer can be selected appropriately from these substances according to the required characteristics. These constituent materials can have different compositions. When two or more of the above substances are used in combination, the composition can be changed by changing the combination, or the composition can be changed by changing the amount of each substance added even if the same combination is used. Can do.

(Resin layer)
Next, the resin layer used in this embodiment will be described. As described above, the resin layer used in this aspect has a pattern in which concave portions or convex portions having a predetermined width are formed. The shape of the pattern of such recesses or projections is not particularly limited as long as the plate-like molecules can form the column structure, but the recesses are formed at regular intervals in a stripe shape. Or it is preferable that it is a pattern in which the convex part is formed regularly.

  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.

  As the film thickness of the resin layer, the thickness of the portion where the recess is formed is usually 1 μm or less, preferably 0.2 μm 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 this embodiment varies depending on the required characteristics of the liquid crystal display element, and the columnar alignment layer has only a column structure, and has a column structure and a resin layer. It is also different. For example, when the columnar alignment layer has only a column structure, the thickness of the columnar alignment layer is usually preferably in the range of 2 nm to 1000 nm, more preferably in the range of 5 nm to 500 nm, and further in the range of 10 nm to 300 nm. preferable. It is difficult to form a columnar alignment layer that is too thin. On the other hand, if the columnar alignment layer 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 40% or more, more preferably 80% or more over the entire region. The transmittance can be measured with a spectroradiometer (model: SR-3) manufactured by Topcon Corporation.

  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 method for producing the columnar alignment layer will be described in detail in the section “B. Method for producing a liquid crystal display element” described later, and therefore description thereof is omitted here.

b. Next, the liquid crystal layer used in the first aspect of the present invention will be described. The liquid crystal layer used in this embodiment is configured by filling a ferroelectric liquid crystal between the two columnar alignment layers described above. Hereinafter, such a ferroelectric liquid crystal will be described.

(Ferroelectric liquid crystal)
The ferroelectric liquid crystal used in this embodiment is not particularly limited as long as it exhibits a chiral smectic C (SmC ^* ) phase. In the temperature lowering process, the cholesteric (Ch) phase-smectic A (SmA) A material that changes phase with the phase-chiral smectic C (SmC ^* ) phase can be used, and a material that changes phase with the Ch phase-SmC ^* phase and does not pass through the SmA phase can also be used. Among them, the ferroelectric liquid crystal used in this embodiment 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.

  In particular, when the liquid crystal display element of this embodiment is driven by a field sequential color method, the ferroelectric liquid crystal used in this embodiment is a ferroelectric liquid crystal exhibiting monostable driving characteristics as described above. Among them, it is preferable to use a ferroelectric liquid crystal driven by half V-shape in which liquid crystal molecules operate only when a positive or negative 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.

Furthermore, the ferroelectric liquid crystal used in this embodiment preferably constitutes a single phase. Constructing a single phase means that a polymer network is not formed as in the polymer stabilization method and the like, and thus using a single-phase ferroelectric liquid crystal, This is because the process becomes easy and the drive voltage can be lowered.
As will be described later, a polymer network may be formed in the liquid crystal layer used in this embodiment.

  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 this embodiment, 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 aspect 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 this embodiment, 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 this embodiment, 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 this embodiment, 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 this embodiment, it is preferable to use an ultraviolet curable liquid crystal monomer that exhibits liquid crystallinity among the ultraviolet curable resin monomers. 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 this embodiment 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. In particular, in this embodiment, 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 this embodiment 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 this embodiment 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.

c. 1st base material and 2nd 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 and a 2nd base material used for this aspect, For example, glass A board, a plastic board, etc. are mentioned preferably. The surface roughness (RSM value) of the substrate used in this embodiment is preferably 10 nm or less, more preferably 3 nm or less, and further preferably 1 nm or less. The surface roughness is a value measured using an atomic force microscope (AFM).

d. First electrode layer and second electrode layer The first electrode layer and the second electrode layer used in the present embodiment are for driving the ferroelectric liquid crystal by applying a signal voltage to the ferroelectric liquid crystal.

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

  When the liquid crystal display element of the present invention is to be driven in 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, and the other 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.

e. Next, the polarizing plate used in this embodiment will be described. The polarizing plate used in this embodiment is provided outside the first base material and the second base material described above, and has a function of transmitting only light polarized in the alignment direction of liquid crystal molecules with linearly polarized incident light. It is what has.

  The polarizing plate used in this embodiment is not particularly limited as long as it transmits only a specific direction in the wave of light, and generally known polarizing plates for liquid crystal display elements can be used. .

(2) Manufacturing method of liquid crystal display element The manufacturing method of the liquid crystal display element of such a 1st aspect is demonstrated below. The liquid crystal display element of this embodiment can be produced by a generally known method as a method for producing a liquid crystal display element.

  Here, an example of a manufacturing method of an active matrix type liquid crystal display element using a TFT element will be described as an example of a manufacturing method of the liquid crystal display element of this embodiment.

First, a transparent conductive film is formed on the first base material by the vapor deposition method described above, and a first electrode layer that is a common electrode on the entire surface is formed. 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 to form a second electrode layer.
Next, a columnar alignment layer is formed on the first electrode layer and the second electrode layer thus formed by a method described later, and beads are dispersed as a spacer in one of the formed columnar alignment layers. A sealant is applied to the periphery, and the two substrates are bonded together so that the columnar alignment layers face each other, and are thermocompression bonded. The ferroelectric liquid crystal is heated from the injection port of the liquid crystal cell thus obtained by 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 form a liquid crystal layer. A polarizing plate is attached to the outside of the first base material and the second base material, and thus the liquid crystal display element of the first aspect can be obtained.

  In this embodiment, 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 this embodiment, 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.

2. Second Aspect Next, a second aspect of the liquid crystal display element of the present invention will be described. In the liquid crystal display element of the second aspect, the first alignment layer and the second alignment layer are the columnar alignment layer, the normal direction of the plate-like molecules of the first alignment layer, and the plate of the second alignment layer Reactive liquid crystal that is arranged substantially perpendicular to the normal direction of the molecule-like molecule and contains a polymerizable liquid crystal material and exhibits a nematic phase is fixed on the opposing surface of the first alignment layer or the second alignment layer. It is characterized by having a reactive liquid crystal layer.

  The liquid crystal display element according to the second aspect will be described below. FIG. 1B shows an example of the liquid crystal display element according to the second aspect of the present invention. In the drawing, the first alignment layer 3a and the second alignment layer 3b are the columnar alignment layers. In this embodiment, the first alignment layer and the second alignment layer are formed as the columnar alignment layer as described above, and the ferroelectric liquid crystal is aligned by a simple method without requiring a rubbing process or a photo-alignment process. It is.

  As shown in FIG. 3B, these alignment layers are substantially perpendicular to the normal direction of the plate molecules of the first alignment layer 3a and the normal direction of the plate molecules of the second alignment layer 3b. Is arranged. Here, “substantially perpendicular” means that the angle θ formed by the normal direction of the plate-like molecules of the first alignment layer 3a and the normal direction of the plate-like molecules of the second alignment layer 3b is 90 ° ± 5 °. It means to be a range. This angle θ is preferably in the range of 90 ° ± 1 °.

  Furthermore, in this embodiment, a reactive liquid crystal layer 6 is formed on the second alignment layer 3b by immobilizing a reactive liquid crystal containing a polymerizable liquid crystal material and exhibiting a nematic phase. The reactive liquid crystal layer 6 is fixed on the second alignment layer 3b, and anisotropy is imparted to the reactive liquid crystal layer 6 by the second alignment layer 3b. It functions as an alignment film for aligning the crystalline liquid crystal. In this case, the alignment direction of the first alignment layer and the second alignment layer in which the normal direction of the plate-like molecules of the first alignment layer and the normal direction of the plate-like molecules of the second alignment layer are arranged substantially perpendicularly are: By passing through this reactive liquid crystal layer, the liquid crystal layer changes in substantially parallel, so that the orientation of the ferroelectric liquid crystal used in the liquid crystal layer can be controlled. Furthermore, since the reactive liquid crystal is relatively similar in structure to the ferroelectric liquid crystal, it has a strong interaction with the ferroelectric liquid crystal and can effectively control the alignment of the ferroelectric liquid crystal. . Even when the constituent materials of the first alignment layer and the second alignment layer have the same composition, the ferroelectric liquid crystal is sandwiched by providing a reactive liquid crystal layer on one of the alignment layers. Thus, the upper and lower layers are different, and the interaction between each layer and the ferroelectric liquid crystal is different, so that the ferroelectric liquid crystal can be aligned without forming alignment defects. In particular, when a ferroelectric liquid crystal exhibiting a phase transition series that does not pass through a smectic A phase (SmA) is used, generation of double domains can be suppressed, and monodomain alignment of the ferroelectric liquid crystal can be obtained.

  In FIG. 1B, the reactive liquid crystal layer 6 is formed on the second alignment layer 3b. In this embodiment, the reactive liquid crystal layer 6 is formed by the first alignment layer 3a or the second alignment layer. It may be formed on any one of the layers 3b, and may be formed on the first alignment layer 3a.

  Each constituent member and manufacturing method of this embodiment will be described below. The liquid crystal layer, the first substrate, the second substrate, the first electrode layer, the second electrode layer, and the polarizing plate used in this embodiment are as follows. The same as described in the section of the first aspect. In addition, the manufacturing method of this embodiment can be performed in the same manner as the method described in the section of the first embodiment except that a reactive liquid crystal layer is provided on the first alignment layer or the second alignment layer. Therefore, these descriptions are omitted. Hereinafter, the first alignment layer, the second alignment layer, and the reactive liquid crystal layer used in this embodiment will be described.

a. First alignment layer and second alignment layer In this embodiment, the first alignment layer and the second alignment layer are columnar alignment layers, and the columnar alignment layer is the same as that described in the first embodiment. However, in this embodiment, the constituent materials of the first alignment layer and the second alignment layer may be different from each other or may be exactly the same.

b. Reactive liquid crystal layer The reactive liquid crystal layer used in this embodiment is formed by immobilizing reactive liquid crystal containing a polymerizable liquid crystal material and exhibiting a nematic phase. Such a reactive liquid crystal is aligned by the first alignment layer or the second alignment layer serving as a base. For example, the reactive liquid crystal is polymerized by irradiating ultraviolet rays, and the reactivity is fixed by fixing the alignment state. A liquid crystal layer is formed. As described above, in this embodiment, the reactive liquid crystal layer is fixed on the first alignment layer or the second alignment layer, and the first alignment layer or the second alignment layer imparts anisotropy to the reactive liquid crystal layer. Therefore, the reactive liquid crystal layer can function as an alignment film for aligning the ferroelectric liquid crystal.

  In addition, since the reactive liquid crystal layer is fixed to the first alignment layer or the second alignment layer in this way, alignment disorder hardly occurs even when the temperature of the ferroelectric liquid crystal is raised to a temperature higher than the phase transition point. It is excellent in alignment stability.

  Furthermore, the reactive liquid crystal used in such a reactive liquid crystal layer is relatively similar in structure to the ferroelectric liquid crystal and has a strong interaction with the ferroelectric liquid crystal. It has the advantage that it can be controlled effectively.

(Reactive liquid crystal)
Hereinafter, the reactive liquid crystal used for such a reactive liquid crystal layer will be described. The reactive liquid crystal used in this embodiment constitutes the reactive liquid crystal layer by being fixed to either the first alignment layer or the second alignment layer, includes a polymerizable liquid crystal material, and is nematic. Phase. This nematic phase is relatively easy to control the alignment among the liquid crystal phases. Thus, by using the reactive liquid crystal exhibiting the nematic phase, the first alignment layer or the second alignment layer serving as a base is reactive. Anisotropy can be easily imparted to the liquid crystal layer. Further, the reactive liquid crystal contains a polymerizable liquid crystal material, so that the alignment state of the reactive liquid crystal can be fixed.

  As the polymerizable liquid crystal material, any of a polymerizable liquid crystal monomer, a polymerizable liquid crystal oligomer, and a polymerizable liquid crystal polymer can be used. In this embodiment, a polymerizable liquid crystal monomer is preferably used. The polymerizable liquid crystal monomer can be aligned at a lower temperature than other polymerizable liquid crystal materials, that is, a polymerizable liquid crystal oligomer and a polymerizable liquid crystal polymer, and has high sensitivity in alignment, and can be easily aligned. Because you can.

  The polymerizable liquid crystal monomer is not particularly limited as long as it is a liquid crystal monomer having a polymerizable functional group, and examples thereof include a monoacrylate monomer and a diacrylate monomer. These polymerizable liquid crystal monomers may be used alone or in combination of two or more.

  As a monoacrylate monomer, the compound represented, for example by a following formula can be illustrated.

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.

  Moreover, as a diacrylate monomer, the compound as shown to a following formula can be mentioned, for example.

In the above formula, X and Y are hydrogen, alkyl having 1 to 20 carbons, alkenyl having 1 to 20 carbons, alkyloxy having 1 to 20 carbons, alkyloxycarbonyl having 1 to 20 carbons, formyl, carbon number 1-20 alkylcarbonyl, C1-C20 alkylcarbonyloxy, halogen, cyano or nitro is represented. M represents an integer in the range of 2-20. X is preferably an alkyloxycarbonyl having 1 to 20 carbon atoms, methyl or chlorine, and among them, an alkyloxycarbonyl having 1 to 20 carbon atoms, particularly CH ₃ (CH ₂ ) ₄ OCO is preferable.

  Furthermore, examples of the diacrylate monomer include compounds represented by the following formula.

In the above formula, Z ³¹ and Z ³² are each independently independently directly bonded —COO—, —OCO—, —O—, —CH ₂ CH ₂ —, —CH═CH—, —C≡C—. _{, -OCH 2 -, - CH 2} O -, - CH 2 CH 2 COO -, - OCOCH 2 CH 2 - ^{represents, R 31} represents an alkyl of 1 to 5 hydrogen or carbon. K and m represent 0 or 1, and n represents an integer in the range of 2 to 8.
In addition, specific examples of the compound represented by the above formula (3) include compounds represented by the following formula.

In the above formula, Z ²¹ and Z ²² are each independently directly bonded —COO—, —OCO—, —O—, —CH ₂ CH ₂ —, —CH═CH—, —C≡C—. _{, -OCH 2 -, - CH 2} O -, - CH 2 CH 2 COO -, - OCOCH 2 CH 2 - represents a. M represents 0 or 1, and n represents an integer in the range of 2-8.

  Especially in this aspect, the compound represented by the said Formula (1) or (3) is used suitably. Examples of the reactive liquid crystal containing the compound represented by the above formula (3) include “Adeka Kiracol PLC-7183” and “Adeka Kiracol PLC-7209” manufactured by Asahi Denka Kogyo Co., Ltd. . Examples of the reactive liquid crystal containing an acrylate monomer include “ROF-5101” and “ROF-5102” manufactured by Rolic technologies.

  Among the above, the polymerizable liquid crystal monomer used in this embodiment is preferably a diacrylate monomer. This is because the diacrylate monomer can be easily polymerized while maintaining the orientation state in a good state.

  The polymerizable liquid crystal monomer described above does not have to exhibit a nematic phase. In this embodiment, these polymerizable liquid crystal monomers may be used as a mixture of two or more kinds as described above, and the composition in which these are mixed, that is, the reactive liquid crystal exhibits a nematic phase. That's fine.

  Furthermore, in this aspect, you may add a photoinitiator and a polymerization inhibitor to the said reactive liquid crystal as needed. For example, when polymerizing a polymerizable liquid crystal material by electron beam irradiation, a photopolymerization initiator may not be necessary, but in the case of polymerization by, for example, ultraviolet irradiation, usually photopolymerization is started. This is because the agent is used for promoting the polymerization.

  Photopolymerization initiators that can be used in this embodiment include benzyl (also called bibenzoyl), benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-benzoyl-4′-methyldiphenyl sulfide. Benzylmethyl ketal, dimethylaminomethylbenzoate, 2-n-butoxyethyl-4-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, 3,3′-dimethyl-4-methoxybenzophenone, methylobenzoyl formate, 2 -Methyl-1- (4- (methylthio) phenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, -(4- Dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl)- 2-hydroxy-2-methylpropan-1-one, 2-chlorothioxanthone, 2,4-diethylthioxanthone 2,4-diisopropylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propoxythioxanthone, etc. Can be mentioned. In addition to the photopolymerization initiator, it is also possible to add a sensitizer as long as the purpose of this embodiment is not impaired.

  The amount of the photopolymerization initiator added is generally 0.01 to 20% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight. It can be added to the liquid crystal.

(Reactive liquid crystal layer)
The thickness of the reactive liquid crystal layer formed by fixing the reactive liquid crystal as described above is preferably in the range of 1 nm to 1000 nm, and more preferably in the range of 3 nm to 100 nm. This is because if the reactive liquid crystal layer is thicker than the above range, anisotropy more than necessary occurs, and if it is thinner than the above range, the predetermined anisotropy may not be obtained. Therefore, the thickness of the reactive liquid crystal layer may be determined according to the required anisotropy.

  Next, a method for forming the reactive liquid crystal layer will be described. The reactive liquid crystal layer applies a reactive liquid crystal layer-forming coating liquid containing the reactive liquid crystal on the first alignment layer or the second alignment layer, performs an alignment treatment, and fixes the alignment state of the reactive liquid crystal. Can be formed.

  Further, instead of applying a coating liquid for forming a reactive liquid crystal layer, a method of forming a dry film or the like in advance and laminating it on the first alignment layer or the second alignment layer can also be used. In the embodiment, a method is used in which a reactive liquid crystal is dissolved in a solvent to prepare a coating liquid for forming a reactive liquid crystal layer, which is applied onto the first alignment layer or the second alignment layer, and the solvent is removed. Is preferred. This is because this method is relatively simple in terms of steps.

  The solvent used in the coating liquid for forming the reactive liquid crystal layer is not particularly limited as long as it can dissolve the reactive liquid crystal and the like and does not inhibit the alignment ability of the columnar alignment layer. For example, hydrocarbons such as benzene, toluene, xylene, n-butylbenzene, diethylbenzene and tetralin; ethers such as methoxybenzene, 1,2-dimethoxybenzene and diethylene glycol dimethyl ether; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 2 Ketones such as 1,4-pentanedione; esters such as ethyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, γ-butyrolactone; 2-pyrrolidone, N-methyl-2-pyrrolidone, dimethylformamide, dimethyl Amide solvents such as acetamide; chloroform, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloroethane, tritrichloroethylene, tetra Halogen-based solvents such as chloroethylene, chlorobenzene and orthodichlorobenzene; alcohols such as t-butyl alcohol, diacetone alcohol, glycerin, monoacetin, ethylene glycol, triethylene glycol and hexylene glycol; phenols such as phenol and parachlorophenol; One type or two or more types of cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, and ethylene glycol monomethyl ether acetate can be used.

  In addition, the use of a single type of solvent may result in insufficient solubility of the reactive liquid crystal or the like, or the columnar alignment layer may be eroded. Therefore, this inconvenience can be avoided. Among the above-mentioned solvents, preferred as a single solvent are hydrocarbons and glycol monoether acetate solvent, and preferred as a mixed solvent is a mixed system of ethers or ketones and glycol solvent. It is. The concentration of the coating liquid for forming the reactive liquid crystal layer cannot be defined unconditionally because it depends on the solubility of the reactive liquid crystal and the thickness of the reactive liquid crystal layer to be formed, but usually 1 to 60% by weight, Preferably, it is adjusted in the range of 3 to 40% by weight.

  Furthermore, the following compounds can be added to the reactive liquid crystal layer-forming coating solution as long as the purpose of this embodiment is not impaired. Examples of compounds that can be added include polyester (meth) acrylate obtained by reacting (meth) acrylic acid with a polyester prepolymer obtained by condensing polyhydric alcohol and monobasic acid or polybasic acid; A polyurethane (meth) acrylate obtained by reacting a compound having two isocyanate groups with each other and then reacting the reaction product with (meth) acrylic acid; bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak Type epoxy resins, polycarboxylic acid polyglycidyl esters, polyol polyglycidyl ethers, aliphatic or cycloaliphatic epoxy resins, amine epoxy resins, triphenolmethane type epoxy resins, dihydroxybenzene type epoxy resins and the like (meth) Acry Photopolymerizable compound in epoxy (meth) acrylate obtained by reacting an acid; photopolymerizable liquid crystal compound having an acryl group or methacryl group and the like. The amount of these compounds added to the reactive liquid crystal is selected within a range that does not impair the purpose of this embodiment. Addition of these compounds improves the curability of the reactive liquid crystal, increases the mechanical strength of the resulting reactive liquid crystal layer, and improves its stability.

  As a method for applying such a coating liquid for forming a reactive liquid crystal layer, a spin coating method, a roll coating method, a printing method, a dip coating method, a curtain coating method (die coating method), a casting method, a bar coating method, a blade Examples thereof include a coating method, a spray coating method, a gravure coating method, a reverse coating method, and an extrusion coating method.

  In addition, the solvent is removed after the reactive liquid crystal layer forming coating solution is applied, and the removal of the solvent is performed by, for example, removal under reduced pressure or removal by heating, or a combination thereof. .

  In this embodiment, the reactive liquid crystal applied as described above is aligned by the columnar alignment layer to have a liquid crystal regularity. That is, a nematic phase is developed in the reactive liquid crystal. This is usually performed by a method such as a method of performing a heat treatment below the NI transition point. Here, the NI transition point indicates the temperature at which the liquid crystal phase transitions to the isotropic phase.

  As described above, the reactive liquid crystal contains a polymerizable liquid crystal material, and in order to fix the alignment state of such a polymerizable liquid crystal material, a method of irradiating active radiation that activates polymerization is used. . The active radiation as used herein refers to radiation capable of causing polymerization of the polymerizable liquid crystal material. If necessary, a photopolymerization initiator may be included in the polymerizable liquid crystal material.

  The actinic radiation is not particularly limited as long as it is a radiation capable of polymerizing the polymerizable liquid crystal material, but usually ultraviolet light or visible light is used from the viewpoint of the ease of the apparatus. Irradiation light having a wavelength of 150 to 500 nm, preferably 250 to 450 nm, and more preferably 300 to 400 nm is used.

  In this embodiment, it can be said that a preferable method is to irradiate a polymerizable liquid crystal material in which the photopolymerization initiator generates radicals with ultraviolet rays and radically polymerizes the polymerizable liquid crystal material with ultraviolet rays as active radiation. . This is because the method using ultraviolet rays as the actinic radiation is an already established technique, and therefore it can be easily applied to this embodiment including the photopolymerization initiator to be used.

  As the light source of this irradiation light, low pressure mercury lamp (sterilization lamp, fluorescent chemical lamp, black light), high pressure discharge lamp (high pressure mercury lamp, metal halide lamp), short arc discharge lamp (super high pressure mercury lamp, xenon lamp, mercury xenon) Lamp). In particular, the use of metal halide lamps, xenon lamps, high-pressure mercury lamps, etc. is recommended. The irradiation intensity is appropriately adjusted according to the composition of the reactive liquid crystal and the amount of photopolymerization initiator.

  Such irradiation with active radiation may be performed under a temperature condition in which the polymerizable liquid crystal material becomes a liquid crystal phase, or may be performed at a temperature lower than the temperature at which the liquid crystal phase is formed. This is because the alignment state of the polymerizable liquid crystal material once in the liquid crystal phase is not disturbed suddenly even if the temperature is lowered thereafter.

  As a method for fixing the alignment state of the polymerizable liquid crystal material, in addition to the method of irradiating the active radiation, a method of polymerizing the polymerizable liquid crystal material by heating can also be used.

3. Third Aspect Next, a third aspect of the liquid crystal display element of the present invention will be described. The liquid crystal display element according to the third aspect is characterized in that the first alignment layer is the columnar alignment layer and the second alignment layer is a photo-alignment film.

  The liquid crystal display element according to the third aspect will be described below. FIG. 1A shows an example of a liquid crystal display element according to the third aspect of the present invention. In the drawing, the first alignment layer 3a is the columnar alignment layer, and the second alignment layer 3b is light. As shown in FIG. 3 (a), the normal direction of the plate-like molecules of the first alignment layer 3a and the alignment direction of the second alignment layer 3b are arranged substantially in parallel as shown in FIG. This simplifies the alignment process and obtains the monodomain alignment of the ferroelectric liquid crystal without causing alignment defects. The definition of “substantially parallel” is the same as that described in the first embodiment.

  Hereinafter, although each structural member and manufacturing method of this aspect are demonstrated, the 1st orientation layer used for this aspect is a columnar orientation layer, About this columnar orientation layer, what was described in the term of the 1st aspect Since it is the same, description here is abbreviate | omitted. In addition, the liquid crystal layer, the first base material, the second base material, the first electrode layer, the second electrode layer, and the polarizing plate used in this aspect should be the same as those described in the first aspect. Further, the manufacturing method of this embodiment is the same as the method described in the section of the first embodiment except that the second alignment layer is a rubbing alignment film or a photo-alignment film. Omitted. Hereinafter, the second alignment layer used in this embodiment will be described.

a. Second alignment layer The second alignment layer used in this embodiment has a function of controlling the alignment of the ferroelectric liquid crystal by sandwiching the ferroelectric liquid crystal together with the first alignment layer. The alignment layer is a photo-alignment film.

  The photo-alignment film used in this embodiment is not particularly limited as long as it is generally used for a liquid crystal display element, and the substrate on which a constituent material of the photo-alignment film described later is applied is irradiated with light whose polarization is controlled. Then, anisotropy is imparted to the film obtained by causing a photoexcitation reaction (decomposition, isomerization, dimerization) to align liquid crystal molecules on the film.

  The constituent material of such a photo-alignment film is not particularly limited as long as it has an effect of aligning ferroelectric liquid crystals (photo-alignment) by irradiating light and causing a photoexcitation reaction. However, such a material is large, and a photoreactive material that imparts anisotropy to the photoalignment film by causing a photoreaction, and an anisotropy in the photoalignment film by causing a photoisomerization reaction. It can be divided into the photoisomerization reaction type material to be provided. In addition, the wavelength region of light in which the constituent material of the photo-alignment film causes a photoexcitation reaction is preferably in the ultraviolet region, that is, in the range of 10 nm to 400 nm, and preferably in the range of 250 nm to 380 nm. More preferred. 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 this embodiment is not particularly limited as long as it has such characteristics, but among them, the photo-alignment film is formed by causing a photodimerization reaction or a photodecomposition reaction. A material that imparts anisotropy is preferred.

  Here, the photodimerization reaction refers to a reaction in which a reaction site oriented in the polarization direction by light irradiation undergoes radical polymerization and two molecules are polymerized. This reaction stabilizes the orientation in the polarization direction and makes the photo-alignment film different. It is possible to impart directionality. On the other hand, the photodecomposition reaction is a reaction that decomposes molecular chains such as polyimide oriented in the polarization direction by light irradiation. This reaction leaves a molecular chain oriented in the direction perpendicular to the polarization direction, and is different from the photo-alignment film. It is possible to impart directionality. In this embodiment, among these photoreactive materials, it is more preferable to use a material that imparts anisotropy to the photoalignment film by a photodimerization reaction because of 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 this embodiment, 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 photo-alignment processing method using the photoreactive material will be described. In this embodiment, the photo-alignment treatment method is not particularly limited as long as anisotropy can be imparted to the photo-alignment film. For example, the surface facing the liquid crystal layer of the substrate provided with the electrode layer The coating material obtained by diluting the constituent material of the photo-alignment film described above with an organic solvent may be coated and dried. 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 this embodiment, 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 this embodiment 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 this embodiment, 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 this embodiment, 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.

  In addition to the photoisomerization reactive compound, the photoisomerization type material used in this embodiment may contain an additive within a range that does not interfere with the photoalignment property of the photoalignment film. 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.

The photo-alignment treatment when such a photoisomerization type material is used can be performed by the same method as that when the photoreaction type material is used, but in this case, the light in the coating liquid is used. The content of the isomerization 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. Next, a method for manufacturing a liquid crystal display element of the present invention will be described. The method for producing a liquid crystal display element of the present invention is the method for producing a liquid crystal display element of the present invention described in the above section “A. Liquid crystal display element”. In the formation of the columnar alignment layer, A coating film forming process for forming a coating film by applying a coating liquid for forming a columnar alignment layer, a drying process for drying the coating film, and an immobilization process for hydrophobizing and fixing the dried coating film It has a process.

  Thus, in the present invention, in the formation of the columnar alignment layer, a coating film is formed by applying a coating liquid for forming a columnar alignment layer containing a plate-like molecule on the substrate, and this coating film is dried. After that, the coating film is hydrophobized and fixed, so that the orientation of the ferroelectric liquid crystal can be controlled by a simple method without requiring an orientation treatment such as a rubbing orientation treatment or a photo-alignment treatment. A columnar alignment layer that can be formed is formed.

  Further, in the present invention, by providing the above-described immobilization treatment step, the hydrophilic group of the plate molecule formed on the substrate is hydrophobized, and the column structure composed of the plate molecule is fixed. Therefore, a liquid crystal display element excellent in the alignment stability of the ferroelectric liquid crystal can be obtained.

  In the present invention, as described in the above section “A. Liquid crystal display element”, the columnar alignment layer may be a single layer in which a column structure is formed, and has a concave or convex surface having a predetermined width on the surface. The portion may have a resin layer formed in a pattern and a column structure formed along the concave portion of the resin layer. At this time, in order to form a columnar alignment layer that is a single layer in which a column structure is formed, a columnar alignment layer forming coating solution is applied on the substrate, while the resin layer and the column structure are separated. In order to form the columnar alignment layer, the resin layer is first formed on the substrate, and the columnar alignment layer forming coating solution is applied on the resin layer. In any case, the column structure is formed by applying the columnar alignment layer forming coating liquid without applying an alignment treatment such as a rubbing alignment treatment or a photo-alignment treatment. Since it can be aligned, a columnar alignment layer can be formed by a roll-to-roll process, and the production efficiency can be improved.

  The manufacturing method of the liquid crystal display element of the present invention will be described below. The method of the present invention is characterized by the formation of the columnar alignment layer as described above. Can be performed in the same manner as described in the above section “A. Liquid crystal display element”, and thus description thereof is omitted here. Hereinafter, a method for forming the columnar alignment layer used in the present invention will be described.

  As described above, the columnar alignment layer forming method used in the present invention includes a coating film forming step of applying a coating liquid for forming a columnar alignment layer on a base material to form a coating film, and the above coating film. It has a drying process which dries, and an immobilization process which hydrophobizes and fixes the dried coating film. Hereinafter, each step will be described.

(1) Coating film formation process First, a coating film formation process is demonstrated. In this step, a coating solution is formed by applying a coating liquid for forming a columnar alignment layer on the substrate. Hereinafter, the columnar alignment layer forming coating solution used in this step and the coating method thereof will be described.

(Coating liquid for forming columnar alignment layer)
First, the columnar alignment layer forming coating solution used in this step will be described. The columnar alignment layer forming coating solution used in this step is obtained by dispersing or dissolving plate-like molecules in a solvent such as water. The solvent for dispersing or dissolving the plate molecule is not particularly limited as long as it is inert to the plate molecule, and 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.

  Moreover, 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 align, the plate-like molecules can be aligned along the alignment direction of the liquid crystal material by aligning the liquid crystal material. As the liquid crystal material, a liquid crystal material that can be generally used for forming an alignment layer can be used. Further, the liquid crystal composition of the liquid crystal material and the plate-like molecule may show a lyotropic liquid crystal phase or a thermotropic liquid crystal phase, but usually shows a thermotropic liquid crystal phase. Is used.

  The columnar alignment layer forming coating solution may further contain various additives such as a surfactant such as polyethylene glycol, if necessary.

  Among the above, in this embodiment, the columnar alignment layer forming coating solution is preferably aqueous. This is because use of an aqueous columnar alignment layer forming coating solution facilitates handling.

  The plate-like molecules used in the columnar alignment layer-forming coating solution are as described in the above section “A. Liquid crystal display element”, and thus description thereof is omitted here.

(Coating method for coating liquid for forming columnar alignment layer)
Next, a coating method for coating such a columnar alignment layer forming coating solution on the substrate will be described. In this step, 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. In this coating method, the column structure is formed on a flat surface such as the substrate described in the above section “A. Liquid crystal display element”, or a resin layer in which concave or convex portions are formed in a pattern on the surface. It can be determined appropriately depending on whether it is formed on such an uneven surface.

  For example, when a column structure is formed on a substrate, it is preferable to use a coating method in which shear stress is applied. This is because the column structure can be easily formed by using a coating method in which shear stress is applied. Examples of the application 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 a resin layer having concave or convex portions formed on the surface, the column structure is formed along the uneven shape on the resin layer by using a coating method that does not apply shear stress. It is preferable. 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.

(2) Drying process Next, the drying process of evaporating the solvent contained in the coating film formed as described above to dry the coating film will be described. In the present invention, by providing this drying process, an immobilization process described later is smoothly performed.

  The drying method used in this step is not particularly limited as long as it does not destroy the column structure formed on the coating film or deform the concave or convex pattern of the resin layer. In addition, 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.

(3) Immobilization treatment step Next, in the present invention, the hydrophilic group of the plate molecule is hydrophobized to make the plate molecule insoluble or sparingly soluble in water, thereby fixing the column structure composed of the plate molecule. An immobilization process is performed. By providing such an immobilization treatment step, it is possible to impart water resistance to the formed columnar alignment layer, and the liquid crystal display element thus obtained has a disordered column structure due to moisture in the air or the like. Therefore, the alignment stability of the ferroelectric liquid crystal can be excellent.

  The hydrophobizing solution used in this step is to hydrophilize the hydrophilic group of the plate molecule, is inert to the plate molecule, and destroys the column structure composed of the plate molecule. Otherwise, it is not particularly limited, and it varies depending on the hydrophilic group of the plate molecule used, but it is preferable that a bridge can be formed between adjacent plate molecules.

As such a hydrophobizing treatment solution, specifically, an aqueous solution of an alkaline earth metal salt such as barium salt, calcium salt, magnesium salt can be used, such as an aqueous solution of barium chloride, an aqueous solution of calcium chloride, an aqueous solution of magnesium chloride, etc. Is mentioned. 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. It is.

  The hydrophobizing treatment method is not particularly limited as long as the hydrophilic substituent can be hydrophobized. The hydrophobizing treatment is performed after drying the columnar alignment layer forming coating solution. Examples thereof include a method of applying a liquid and a method of immersing in the hydrophobizing treatment liquid. After application or immersion of the hydrophobizing solution, the columnar alignment layer can be formed by washing and drying.

  On the other hand, when the plate-like molecule has a long-chain alkyl group, a polymerizable group is introduced into the core part of the plate-like molecule or a part of the alkyl side chain, and this polymerizable group is polymerized to form a plate-like molecule. The molecules can be cross-linked in a linear or network form to fix the alignment state.

  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.

  In the present invention, the columnar alignment layer can be easily formed by simply applying the coating liquid for forming the columnar alignment layer and performing simple post-treatment. In addition, since the column structure is fixed, a liquid crystal display element excellent in the alignment stability of the ferroelectric liquid crystal can be manufactured.

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

  The following examples illustrate the present invention in more detail.

[Example 1]
(Preparation of first alignment substrate)
A 12% aqueous solution of a plate-like molecule represented by the following chemical formula (A) is applied onto a well-cleaned glass substrate with an ITO electrode using a slot die coater, dried, and then applied to a 15% barium chloride aqueous solution. It was immersed 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 0.1 μm.

(Production of second alignment substrate)
A second alignment substrate having a 0.2 μm-thick columnar alignment layer was obtained in the same manner as in the above method except that the compound represented by the following chemical formula (B) was used as the plate-like molecule.

(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 onto the columnar alignment layer of the second alignment substrate using a seal dispenser, and the columner of the first alignment substrate is applied. The first alignment substrate so that the normal direction of the plate-like molecules of the alignment layer is parallel to the normal direction of the plate-like molecules of the columnar alignment layer of the second alignment substrate, and the columnar alignment layers of each other face each other. And the 2nd orientation board | substrate was arrange | positioned and bonded 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 cooled slowly, uniform alignment of monodomains was obtained.

[Example 2]
(Preparation of first alignment substrate)
A 12% aqueous solution of a plate-like molecule represented by the above chemical formula (A) is applied onto the ITO film of a glass substrate with an ITO electrode that has been thoroughly cleaned using a slot die coater, and after drying, it is applied to a 15% barium chloride aqueous solution. It was immersed for about 1 second. Further, it was washed and dried again to form a columnar alignment layer having a thickness of 0.1 μm.
On this columnar alignment layer, a solution dissolved in cyclopentanone so that the concentration of the reactive liquid crystal represented by the following chemical formula (C) was 2% by weight was spin-coated at 4000 rpm for 30 seconds. After drying at 55 ° C. for 3 minutes, non-polarized ultraviolet rays were irradiated at 1000 ° C./cm ² at 55 ° C. to form a reactive liquid crystal layer to obtain a first alignment substrate.

(Production of second alignment substrate)
In the same manner as in Example 1, a second alignment substrate having a columnar alignment layer having a thickness of 0.2 μm was obtained.

(Formation of liquid crystal layer)
A bead spacer having a diameter of 1.5 μm is dispersed on the reactive liquid crystal layer of the first alignment substrate, a sealing material is applied onto the columnar alignment layer of the second alignment substrate using a seal dispenser, and the first alignment substrate The normal direction of the plate molecule of the columnar alignment layer and the normal direction of the plate molecule of the columnar alignment layer of the second alignment substrate are orthogonal to each other, and the reactive liquid crystal layer and the columnar alignment layer are opposed to each other. The first alignment substrate and the second alignment substrate were disposed and bonded 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 cooled slowly, uniform alignment of monodomains was obtained.

[Example 3]
(Preparation of first alignment substrate)
In the same manner as in Example 1, a first alignment substrate having a columnar alignment layer having a thickness of 0.1 μm was obtained.

(Production of second alignment substrate)
A solution dissolved in cyclopentanone at 4000 rpm so that the concentration of the photodimerization reactive compound represented by the following chemical formula (D) is 2% by weight on the ITO film of the glass substrate with an ITO electrode that has been thoroughly cleaned. Spin coated for 30 seconds. After drying at 180 ° C. for 10 minutes, 100 mJ / cm ^{2 of} polarized ultraviolet rays were irradiated to form a photo-alignment film to obtain a first 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 normal direction of the plate-like molecules of the alignment layer is parallel to the alignment direction of the photo-alignment film of the second alignment substrate, and the columnar alignment layer and the photo-alignment film face each other. An alignment substrate was placed and bonded. 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 4]
(Preparation of first alignment substrate)
A UV-curable acrylate resin composition having the following composition is spin-coated on a well-cleaned glass substrate with an ITO electrode, and a recess-forming substrate on which irregularities are formed by an electron beam drawing method is placed on the ITO film. A weight of ² was applied for 1 minute. In this state, the ultraviolet light irradiating 100 mJ / cm ^2, further after peeling the recess-forming substrate, the ultraviolet light 3000 mJ / cm ² was irradiated, width 0.2 [mu] m, pitch 0.4 .mu.m, a depth of 0.2 [mu] m A striped concave pattern was formed. The surface was hydrophilized by adding a plasma treatment thereto.

<Ultraviolet curable acrylate resin composition>
・ 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

  A 12% aqueous solution of a plate-like molecule represented by the chemical formula (A) was applied onto the concave pattern using an ink jet, dried, and then immersed in a 15% aqueous barium chloride solution for about 1 second. Further, it was washed and dried again to form a columnar alignment layer having a column structure having a thickness of 0.1 μm to obtain a first alignment substrate.

(Production of second alignment substrate)
In the same manner as in Example 1, a second alignment substrate having a columnar alignment layer having a thickness of 0.2 μm was obtained.

(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 onto the columnar alignment layer of the second alignment substrate using a seal dispenser, and the columner of the first alignment substrate is applied. The first alignment substrate so that the normal direction of the plate-like molecules of the alignment layer is parallel to the normal direction of the plate-like molecules of the columnar alignment layer of the second alignment substrate, and the columnar alignment layers of each other face each other. And the 2nd orientation board | substrate was arrange | positioned and bonded 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 cooled slowly, uniform alignment of monodomains was obtained.

[Example 5]
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 figure explaining arrangement | positioning of the 1st orientation layer and 2nd orientation 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 4a, 4b ... Polarizing plate 5 ... Liquid crystal layer 6 ... Reactive liquid crystal layer 7 ... TFT element 11 ... First alignment substrate 12 ... Second alignment substrate a ... Plate-like molecule b ... Column structure c ... Resin layer n ... Normal direction

Claims (11)

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. The first alignment layer and the second alignment layer are arranged so as to face each other, and a ferroelectric liquid crystal is sandwiched between the first alignment layer and the second alignment layer, and at least of the first alignment layer and the second alignment layer. One is a liquid crystal display element in which the plate-like molecule is a columnar alignment layer having a column structure in which the normal direction of the plate-like molecule is stacked so as to face a certain direction of the substrate,
The first alignment layer and the second alignment layer are the columnar alignment layers, and the normal direction of the plate molecules of the first alignment layer and the normal direction of the plate molecules of the second alignment layer are substantially parallel. disposed, the liquid crystal display device you wherein the constituent material of the first alignment layer and the second alignment layer are those having a different composition from each other. 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. The first alignment layer and the second alignment layer are arranged so as to face each other, and a ferroelectric liquid crystal is sandwiched between the first alignment layer and the second alignment layer, and at least of the first alignment layer and the second alignment layer. One is a liquid crystal display element in which the plate-like molecule is a columnar alignment layer having a column structure in which the normal direction of the plate-like molecule is stacked so as to face a certain direction of the substrate,
The first alignment layer and the second alignment layer are the columnar alignment layers, and the normal direction of the plate molecules of the first alignment layer and the normal direction of the plate molecules of the second alignment layer are substantially perpendicular. And having a reactive liquid crystal layer formed by fixing a reactive liquid crystal containing a polymerizable liquid crystal material and exhibiting a nematic phase on the opposing surface of the first alignment layer or the second alignment layer. liquid crystal display elements you wherein there. 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. The first alignment layer and the second alignment layer are arranged so as to face each other, and a ferroelectric liquid crystal is sandwiched between the first alignment layer and the second alignment layer, and at least of the first alignment layer and the second alignment layer. One is a liquid crystal display element in which the plate-like molecule is a columnar alignment layer having a column structure in which the normal direction of the plate-like molecule is stacked so as to face a certain direction of the substrate,
The first alignment layer is the columnar alignment layer, you and said second alignment layer is a photo alignment layer liquid crystal display device. The constituent material of the photo-alignment film is a photo-reactive material that imparts anisotropy to the photo-alignment film by causing a photoreaction or anisotropy to the photo-alignment film by causing a photoisomerization reaction The liquid crystal display element according to claim 3 , wherein the liquid crystal display element is a photoisomerization reaction type material. 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 any one of claims 1 to 4 . The liquid crystal display element according to any one of claims 1 to 5 , wherein the plate-like molecules exhibit a lyotropic liquid crystal phase in an aqueous solution. The ferroelectric liquid crystal, the liquid crystal display device according to any one of claims from claim 1, characterized in that shows the monostable drive characteristics to claim 6. The ferroelectric liquid crystal, the liquid crystal display device according to any one of claims of claims 1 to 7, characterized in that indicate the phase transition series which does not pass through the smectic A phase in the cooling process. The liquid crystal display element according to any one of claims 1 to 8, wherein the first electrode layer or the second electrode layer includes a thin film transistor and is driven by an active matrix. The liquid crystal display element according to any one of claims 1 to 9 , wherein the liquid crystal display element is driven by a field sequential color system. It is a manufacturing method of the liquid crystal display element of any one of Claim 1- Claim 10 , Comprising: In formation of the said columnar alignment layer, the coating liquid for columnar alignment layer formation is apply | coated on a base material. A coating film forming step for forming a coating film, a drying step for drying the coating film, and an immobilization processing step for hydrophobizing and fixing the dried coating film. A method for manufacturing a display element.

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