JP2010191256A - Liquid crystal display element and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display element hardly generating alignment disturbance when a ferroelectric liquid crystal is dropped in a liquid crystal encapsulated region partitioned by a partition wall and to provide a method for manufacturing the same. <P>SOLUTION: In the liquid crystal display element having the ferroelectric liquid crystal interposed between a first alignment treatment substrate having a plurality of generally regularly hexagonal partition walls and a second alignment treatment substrate, each of the generally regularly hexagonal partition walls has two sides parallel to a gate line or a source line and four sides crossing the gate line and source line, the four sides crossing the gate line and source line are formed in a stage shape along a pixel and the plurality of generally regularly hexagonal partition walls are arranged in a honeycomb shape. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal display element using a ferroelectric liquid crystal and having partition walls, and a method for manufacturing the same.

  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. So far, liquid crystal display elements have been developed and put to practical use, such as TN mode, STN multiplex drive, and active matrix drive using thin layer transistors (TFTs) for TN, but these use nematic liquid crystals. In addition, the response speed of the liquid crystal material is as slow as several ms to several tens of ms, and it cannot be said that it is sufficiently compatible with moving image display.

  Ferroelectric liquid crystal (FLC) is a liquid crystal suitable for high-speed devices because its response speed is as short as μs order. Ferroelectric liquid crystals proposed by Clark and Lagerwal are widely known as bistable having two stable states when no voltage is applied (the upper part of FIG. 9). In recent years, the state of the liquid crystal layer when no voltage is applied has been stabilized in one state (hereinafter referred to as “monostable”). It has been noted that gradation display is possible by continuously changing the slope of the light intensity and modulating the transmitted light intensity by analog modulation (see Non-Patent Document 1, lower part of FIG. 9).

As the liquid crystal showing bistability, generally, cholesteric (Ch) phase in the cooling process - smectic A (SmA) phase - chiral smectic C (SmC ^*) phase and a phase change, the SmC ^* phase via the SmA phase The ferroelectric liquid crystal shown is used (lower part of FIG. 10). As the liquid crystal exhibiting monostability, generally, a ferroelectric liquid crystal that changes phase with the cholesteric phase (Ch) -chiral smectic C (SmC ^* ) phase in the temperature lowering process and does not pass through the smectic A (SmA) phase is used. (The upper part of FIG. 10). Among the ferroelectric liquid crystals currently reported, the liquid crystal material having a phase series that passes through the SmA phase is more than the latter liquid crystal material that does not pass through the SmA phase.

Ferroelectric liquid crystals are difficult to align because they have higher molecular ordering than nematic liquid crystals. Also, the chiral smectic C (SmC ^* ) phase is very vulnerable to external impact. Therefore, in general, partition walls are formed on a substrate in order to improve impact resistance.

  In recent years, a liquid crystal dropping (One Drop Fill: ODF) method has attracted attention as a liquid crystal sealing method. This is because a sealant is applied to one of a pair of substrates in a frame shape so as to surround a liquid crystal sealing region, liquid crystal is dropped on the substrate, and then both substrates are overlapped with a sufficiently reduced pressure between both substrates. It is made to adhere through a sealing agent. The liquid crystal dropping method has an advantage that the time required for the liquid crystal sealing step is significantly shortened as compared with the conventional vacuum injection method.

  In this liquid crystal dropping method, it is known to drop liquid crystal uniformly in order to obtain a uniform cell gap (see, for example, Patent Document 1 and Patent Document 2). When the partition is formed on the substrate, the liquid crystal is uniformly dropped onto the liquid crystal sealing region separated by the partition.

  Further, as the pattern shape of the partition walls, a stripe shape, a matrix shape, a honeycomb shape, and the like are known (see, for example, Patent Document 3 and Patent Document 4).

JP 2001-337331 A JP 2005-115155 A JP 2002-82340 A JP 2005-274599 A

NONAKA, T., LI, J., OGAWA, A., HORNUNG, B., SCHMIDT, W., WINGEN, R., and DUBAL, H., 1999, Liq. Cryst., 26, 1599.

  Ferroelectric liquid crystals are difficult to align because of the high order of molecules, and when the ferroelectric liquid crystal is dropped into a liquid crystal encapsulated region separated by a partition wall, alignment disorder is likely to occur.

  For example, as shown in FIG. 16, when the liquid crystal 54 is dropped on the central portion 53a of the liquid crystal sealing region 52 separated by the square partition walls 51 formed in a matrix, the liquid crystal 54 is radially wetted in an arbitrary direction. spread. In this case, the distance from the central portion 53a of the square liquid crystal sealing region 52 to the corner 53b and the side 53c is shorter from the central portion 53a to the side 53c. At this time, when the liquid crystal 54 is dropped in an amount suitable for the square liquid crystal sealing region 52, the flow rate of the liquid crystal is constant in any direction, and the distance from the central portion 53a to the side 53c is shorter. In the vicinity of the side 53c, the liquid crystal overflows from the partition wall or the flow direction of the liquid crystal changes.

  As described above, since the ferroelectric liquid crystal has a high molecular order and is difficult to align, when the ferroelectric liquid crystal is used in the above example, alignment disorder occurs near the side 53c.

  The present invention has been made in view of the above circumstances, and provides a liquid crystal display element in which alignment disorder is less likely to occur when a ferroelectric liquid crystal is dropped in a liquid crystal sealing region separated by a partition, and a method for manufacturing the same. The main purpose.

  In order to achieve the above object, the present invention provides a first base material, a first electrode layer and a plurality of substantially regular hexagonal partitions formed on the first base material, the first electrode layer and a substantially positive A first alignment treatment substrate having a first alignment film formed on a hexagonal partition, a second base material, a second electrode layer formed on the second base material, and the second electrode A second alignment processing substrate having a second alignment film formed on the layer is disposed so that the first alignment film and the second alignment film face each other, and the first alignment film and the second alignment film are arranged. A substantially liquid crystal display element having a ferroelectric liquid crystal sandwiched therebetween, wherein the substantially regular hexagonal partition wall includes two sides parallel to the gate line or the source line, and four sides intersecting the gate line and the source line. The four sides intersecting the gate line and the source line are formed in a staircase pattern along the pixel, and Substantially regular hexagonal shape partition wall provides a liquid crystal display element characterized by being arranged in a honeycomb shape.

  According to the present invention, since a substantially regular hexagonal partition is formed, for example, when a ferroelectric liquid crystal is dropped in a region separated by the substantially regular hexagonal partition when a liquid crystal display element is manufactured, the ferroelectric The distance from the center of the region where the liquid crystal is sealed to the six sides of the substantially regular hexagonal partition can be made substantially equal. Therefore, it is possible to suppress the occurrence of disorder in the alignment of the ferroelectric liquid crystal near the partition wall. According to the present invention, since the substantially regular hexagonal partition wall has the predetermined six sides, the substantially regular hexagonal partition wall can be disposed on the gate line and the source line, and luminance unevenness due to the partition wall can be prevented. Furthermore, according to the present invention, since the plurality of substantially regular hexagonal partition walls are arranged in a honeycomb shape, impact resistance can be further improved, and the orientation of the ferroelectric liquid crystal that is vulnerable to external impact can be stably maintained. It is possible.

  In the said invention, it is preferable that the distance between two sides parallel to the gate line or source line of the said substantially regular hexagonal partition is in the range of 3 mm-15 mm. When the distance between the two sides is smaller than the above range, it may be difficult to form a substantially regular hexagonal partition wall. When the distance between the two sides is larger than the above range, the ferroelectric liquid crystal flows. This is because the alignment distance may be relatively long due to the relatively long distance.

  In the present invention, it is preferable that the constituent materials of the first alignment film and the second alignment film have compositions different from each other with the ferroelectric liquid crystal interposed therebetween. This is because the ferroelectric liquid crystal can be aligned without forming alignment defects. In particular, the occurrence of double domains can be effectively suppressed, and monodomain orientation can be obtained.

  Furthermore, in the present invention, the ferroelectric liquid crystal preferably exhibits monostability. By using mono-stable ferroelectric liquid crystal, it becomes possible to drive by an active matrix method using, for example, TFT, and to control gradation by voltage modulation, so that high-definition and high-quality display is possible. This is because it can be realized.

  In this case, it is more preferable that the ferroelectric liquid crystal exhibits a half V-shaped switching characteristic. By using a ferroelectric liquid crystal exhibiting a half V-shaped switching characteristic, the opening time as a black-and-white shutter can be made sufficiently long, whereby each time-switchable color can be displayed brighter and brighter. This is because a color display liquid crystal display element can be realized.

  Further, the present invention provides a plurality of substantially regular hexagonal partitions on the first base material, two sides of the substantially regular hexagonal partitions are parallel to the gate line or the source line, and four sides are the gate line and the source line. A partition forming step of forming a honeycomb shape so that four sides intersecting the gate line and the source line are arranged stepwise along the pixel, and the first electrode layer and the substantially positive electrode A first alignment film forming step of forming a first alignment film on the first substrate on which the hexagonal partition wall is formed, wherein the first electrode layer, the substantially regular hexagonal partition wall and the first alignment are formed on the first substrate; A first alignment treatment substrate preparation step for preparing a first alignment treatment substrate on which a film is formed; and a second alignment treatment substrate on which a second electrode layer and a second alignment film are formed on a second substrate. Two alignment treatment substrate preparation step, and on the first alignment film of the first alignment treatment substrate A liquid crystal dropping step of dropping a ferroelectric liquid crystal at the center of the region separated by the substantially regular hexagonal partition, the first alignment treatment substrate on which the ferroelectric liquid crystal is dropped, and the second alignment There is provided a method for manufacturing a liquid crystal display element, comprising a substrate bonding step of bonding a processing substrate.

  According to the present invention, a ferroelectric liquid crystal in the vicinity of the partition is formed by forming a plurality of substantially regular hexagonal partitions and then dropping the ferroelectric liquid crystal in the center of the region separated by the approximately regular hexagonal partitions. It is possible to prevent the occurrence of the disorder of orientation. Further, according to the present invention, since the substantially regular hexagonal partition walls are formed at predetermined positions, the substantially regular hexagonal partition walls can be disposed on the gate lines and the source lines, and uneven luminance due to the partition walls can be prevented. Furthermore, according to the present invention, the impact resistance can be further improved by forming a plurality of substantially regular hexagonal partition walls in a honeycomb shape.

  In the said invention, it is preferable that the distance between two sides parallel to the gate line or source line of the said substantially regular hexagonal partition is in the range of 3 mm-15 mm. When the distance between the two sides is smaller than the above range, it may be difficult to form a substantially regular hexagonal partition wall. When the distance between the two sides is larger than the above range, the ferroelectric liquid crystal flows. This is because the alignment distance may be relatively long due to the relatively long distance.

  In the present invention, it is preferable to use materials having different compositions across the ferroelectric liquid crystal for the first alignment film and the second alignment film. This is because the ferroelectric liquid crystal can be aligned without forming alignment defects. In particular, the occurrence of double domains can be effectively suppressed, and monodomain orientation can be obtained.

  Furthermore, in the present invention, it is preferable to use the ferroelectric liquid crystal having monostability. By using a ferroelectric liquid crystal exhibiting monostability, it is possible to drive using, for example, an active matrix method using TFTs, and to control gradation by voltage modulation, realizing high-definition and high-quality display. Because it can be done.

  In the present invention, since a substantially regular hexagonal partition is formed, the distance from the center of the region separated by the substantially regular hexagonal partition to the six sides of the substantially regular hexagonal partition can be made substantially equal, There is an effect that the occurrence of disorder in the alignment of the ferroelectric liquid crystal in the vicinity of the partition can be suppressed. In addition, since the substantially regular hexagonal partition wall has predetermined six sides, the substantially regular hexagonal partition wall can be disposed on the gate line and the source line, and the luminance unevenness due to the partition wall can be prevented. Furthermore, since a plurality of substantially regular hexagonal partition walls are arranged in a honeycomb shape, the impact resistance can be further improved, and the orientation of the ferroelectric liquid crystal that is vulnerable to external impact can be stably maintained. Play.

It is a schematic sectional drawing which shows an example of the liquid crystal display element of this invention. It is a schematic sectional drawing which shows the other example of the liquid crystal display element of this invention. FIG. 3 is an enlarged view of a frame A in FIG. 2. It is a figure which shows an example of the liquid crystal dropping process in the manufacturing method of the liquid crystal display element of this invention. It is a figure which shows an example of the substantially regular hexagonal partition in the liquid crystal display element of this invention. It is a schematic sectional drawing which shows the other example of the liquid crystal display element of this invention. It is a schematic sectional drawing which shows the other example of the liquid crystal display element of this invention. It is a schematic diagram which shows the behavior of a liquid crystal molecule. It is the graph which showed the change of the transmittance | permeability with respect to the applied voltage of a ferroelectric liquid crystal. It is the figure which showed the difference in orientation by the difference in the phase sequence which a ferroelectric liquid crystal has. It is a schematic perspective view which shows the other example of the liquid crystal display element of this invention. It is process drawing which shows an example of the manufacturing method of the liquid crystal display element of this invention. It is a figure which shows the other example of the liquid crystal dropping process in the manufacturing method of the liquid crystal display element of this invention. It is a figure which shows an example of the board | substrate bonding process in the manufacturing method of the liquid crystal display element of this invention. FIG. 3 is a diagram showing substantially regular hexagonal partitions in the liquid crystal display element of Example 1. It is a figure which shows an example of the partition in the conventional liquid crystal display element.

  Hereinafter, the liquid crystal display element of the present invention and the manufacturing method thereof will be described in detail.

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 includes a first substrate, a first electrode layer and a plurality of substantially regular hexagonal partitions formed on the first substrate, and the first electrode layer and the substantially regular hexagonal partitions. A first alignment treatment substrate having a first alignment film formed thereon, a second substrate, a second electrode layer formed on the second substrate, and formed on the second electrode layer And a second alignment treatment substrate having a second alignment film is disposed so that the first alignment film and the second alignment film face each other, and between the first alignment film and the second alignment film. A liquid crystal display element sandwiching a ferroelectric liquid crystal, wherein the substantially regular hexagonal partition wall has two sides parallel to the gate line or the source line, and four sides intersecting with the gate line and the source line. The four sides intersecting with the gate line and the source line are formed stepwise along the pixel, and the plurality of substantially regular hexagons. Jo partition wall is characterized in that it is arranged in a honeycomb shape.

The 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, FIG. 2 is a view in which a liquid crystal layer is cut in parallel to the first alignment processing substrate surface in FIG. FIG. 3 is an enlarged view of a frame A in FIG. 2.

  As illustrated in FIG. 1, the liquid crystal display element 1 includes a first substrate 2, a first electrode layer 3 formed on the first substrate 2, and a substantially positive electrode formed on the first electrode layer 3. A first alignment treatment substrate 6 having a hexagonal partition wall 4, a first alignment film 5 formed on the first electrode layer 3 and the substantially regular hexagonal partition wall 4, a second base material 12, and a second substrate It has the 2nd alignment processing substrate 16 which has the 2nd electrode layer 13 formed on the base material 12, and the 2nd alignment film 15 formed on the 2nd electrode layer 13, The 1st alignment processing substrate 6 A ferroelectric liquid crystal is sandwiched between the first alignment film 5 and the second alignment film 15 of the second alignment processing substrate 16 to form the liquid crystal layer 10.

  As illustrated in FIG. 3, the first alignment processing substrate is formed with a gate line 23x, a source line 23y, a TFT element 23t, and a pixel electrode 23p (first electrode layer 3). The gate line 23x and the source line 23y are arranged vertically and horizontally, respectively, and by applying a signal to the gate line 23x and the source line 23y, the TFT element 23t can be operated to drive the ferroelectric liquid crystal. A portion where the gate line 23x and the source line 23y intersect with each other is insulated by an insulating layer (not shown), and the signal on the gate line 23x and the signal on the source line 23y can operate independently. A portion surrounded by the gate line 23x and the source line 23y is a pixel 20 which is a minimum unit for driving the liquid crystal display element. Each pixel 20 includes at least one TFT element 23t and a pixel electrode 23p (first electrode). Layer 3) is formed. Then, the TFT element 23t of each pixel 20 can be operated by sequentially applying a signal voltage to the gate line 23x and the source line 23y.

  The plurality of substantially regular hexagonal partition walls 4 are arranged in a honeycomb shape as illustrated in FIG. In FIG. 2, six sides of the substantially regular hexagonal partition wall 4 are denoted by s1 to s6 clockwise from above. The sides s1, s4 are formed in a straight line, and the sides s2, s3, s5, s6 are formed in a step shape. In FIG. 3, the side s1 is parallel to the gate line 23x, and the sides s5 and s6 intersect the gate line 23x and the source line 23y. That is, the substantially regular hexagonal partition 4 has two sides s1, s4 parallel to the gate line 23x, and four sides s2, s3, s5, s6 intersecting the gate line 23x and the source line 23y. The two sides s1 and s4 parallel to the gate line 23x are linearly formed along the pixel 20, and the four sides s2, s3, s5, and s6 intersecting the gate line 23x and the source line 23y are along the pixel 20. Are stepped.

  The substantially regular hexagonal partition wall does not have a regular hexagonal h shape as illustrated in FIG. 4, but has a shape close to a regular hexagonal shape. In addition, the six sides in the substantially regular hexagonal partition means sides s1 to s6 respectively corresponding to the six sides of the regular hexagon h when the substantially regular hexagon is approximated to the regular hexagon h as illustrated in FIG. The four sides s2, s3, s5, and s6 that intersect the gate line and the source line in the substantially regular hexagonal partition are not straight lines, but are referred to as “sides” in the present invention.

When the liquid crystal display element of the present invention is manufactured, as shown in FIG. 4, when the ferroelectric liquid crystal 26 is dropped on the central portion 25 of the region 24 separated by the substantially regular hexagonal partition walls 4, the ferroelectricity The liquid crystal 26 spreads radially in an arbitrary direction. The distances from the central portion 25 of the region 24 separated by the substantially regular hexagonal partition walls 4 to the six sides s1 to s6 of the substantially regular hexagonal partition walls 4 are substantially equal. At this time, when the ferroelectric liquid crystal 26 is dropped in an amount suitable for the region 24, the distances from the central portion 24 to the sides s1 to s6 are almost equal, so that the ferroelectric liquid crystal is substantially near the substantially regular hexagonal partition wall. It is possible to suppress the overflow from the regular hexagonal partition walls and the change in the flow direction of the ferroelectric liquid crystal. Thereby, it is possible to suppress the occurrence of disorder in the alignment of the ferroelectric liquid crystal near the substantially regular hexagonal partition wall.
As described above, according to the present invention, since the substantially regular hexagonal partition wall is formed, it is possible to make it difficult to cause alignment disorder of the ferroelectric liquid crystal.

  In consideration of the distance from the center of the region separated by the partition walls to the partition walls, it can be said that a circular partition wall is desirable. However, when circular partition walls are arranged closely, a gap is generated between adjacent circular partition walls. In that case, the effective pixel area becomes small. Also, regular polygons that are closer to a circle than regular hexagons, such as regular octagons, regular dodecagons, etc., cannot be arranged without gaps as in the case of circles. Therefore, in the present invention, a regular hexagon is adopted in consideration of an effective pixel area and the like, and a substantially regular hexagon is formed in consideration of elimination of luminance unevenness and the like.

  According to the invention, the substantially regular hexagonal partition wall has two sides parallel to the gate line or the source line and four sides intersecting the gate line and the source line, and the four sides intersecting the gate line and the source line are Since it is formed in a staircase pattern along the pixel, a substantially regular hexagonal partition wall can be disposed on the gate line and the source line. Thereby, it is possible to prevent uneven luminance from occurring between a pixel provided with a partition and a pixel not provided with a partition. In addition, since a substantially regular hexagonal partition wall can be arranged in a non-pixel region that does not affect image display, even if a ferroelectric liquid crystal alignment defect occurs near the substantially regular hexagonal partition wall, image display is possible. Can be minimized.

  Furthermore, according to the present invention, since the plurality of substantially regular hexagonal partition walls are arranged in a honeycomb shape and regularly arranged, the liquid crystal display element is separated by the plurality of substantially regular hexagonal partition walls. Ferroelectric liquid crystal can be dropped into each region in an equal amount. Thereby, a gap can be made uniform and display quality can be improved.

Further, according to the present invention, the plurality of substantially regular hexagonal partition walls are arranged in a honeycomb shape, so that, for example, compared to a case where a plurality of linear partition walls are arranged in a stripe shape, the impact resistance is improved. Can be further improved. Thereby, the alignment of the ferroelectric liquid crystal that is vulnerable to external impact can be stably maintained.
Hereinafter, each structure in the liquid crystal display element of this invention is demonstrated.

1. First Alignment Processed Substrate The first alignment process substrate in the present invention includes a first base material, a first electrode layer and a plurality of substantially regular hexagonal partitions formed on the first base material, and the first electrode layer. And a first alignment film formed on the substantially regular hexagonal partition wall.
Hereinafter, each configuration of the first alignment processing substrate will be described.

(1) Substantially regular hexagonal partition wall The substantially regular hexagonal partition wall in the present invention is formed on the first substrate, and has two sides parallel to the gate line or source line, and the gate line and source line. The four sides intersecting with the gate line and the source line are formed in a staircase pattern along the pixel. The liquid crystal display element of the present invention has a plurality of substantially regular hexagonal partition walls, and the plurality of substantially regular hexagonal partition walls are arranged in a honeycomb shape.

  Of the six sides of the substantially regular hexagonal partition wall, four sides intersecting the gate line and the source line are formed in a staircase pattern along the pixel. For example, as shown in FIG. 3, the sides s5 and s6 intersecting with the gate line 23x and the source line 23y are formed stepwise along the pixel 20, and are arranged on the gate line 23x and the source line 23y. Note that that the side is formed along the pixel means that the side is arranged on the gate line or the source line.

  The sides intersecting with the gate line and the source line need only be formed in a staircase pattern along the pixel, but are formed in a staircase pattern so that the shape of the substantially regular hexagonal partition is as close as possible to the regular hexagonal shape. It is preferable that This is because the distance from the center of the region separated by the substantially regular hexagonal partition to the six sides of the substantially regular hexagonal partition can be made more uniform.

  Further, the side parallel to the gate line or the source line is preferably formed in a straight line along the pixel. This is because two sides of the substantially regular hexagonal partition wall parallel to the gate line or the source line can be arranged on the gate line or the source line. For example, in FIG. 3, the side s1 parallel to the gate line 23x and the source line 23y is formed linearly along the pixel 20 and is disposed on the gate line 23x.

  As the shape of the substantially regular hexagonal partition wall, the substantially regular hexagonal partition wall has two sides parallel to the gate line or the source line, and four sides that intersect with the gate line and the source line and are formed stepwise along the pixel. And may be symmetric or asymmetric. Usually, the shape of the substantially regular hexagonal partition wall is vertically and / or bilaterally symmetric.

  Further, the shape of the substantially regular hexagonal partition walls may be one type or a plurality of types as long as a plurality of substantially regular hexagonal partition walls are arranged in a honeycomb shape. For example, the shape of the substantially regular hexagonal partition wall 4 shown in FIG. 5A includes two shapes, a substantially regular hexagonal partition wall 4a shown in FIG. 5B and a substantially regular hexagonal partition wall 4b shown in FIG. There are types. In FIG. 5 (a), the two types of substantially regular hexagonal partition walls 4a and 4b are arranged in a honeycomb shape sharing their respective sides. When there are a plurality of types of substantially regular hexagonal partition walls, there are usually two types.

As the size of the substantially regular hexagonal partition wall, the distance between two sides parallel to the gate line or the source line of the substantially regular hexagonal partition wall is preferably about 3 mm to 15 mm, more preferably in the range of 5 mm to 10 mm. Is within. When the distance between the two sides is smaller than the above range, it may be difficult to form a substantially regular hexagonal partition wall. When the distance between the two sides is larger than the above range, the ferroelectric liquid crystal flows. This is because the alignment distance may be relatively long due to the relatively long distance.
The distance between two sides parallel to the gate line or the source line of the substantially regular hexagonal partition wall is two sides s1, parallel to the gate line or the source line of the substantially regular hexagonal partition wall as illustrated in FIG. This is the distance d from the center of s4 to the center.

The size of the substantially regular hexagonal partition wall is 5 to 300, although the number of pixels arranged in one substantially regular hexagonal partition wall varies depending on the number of pixels of the liquid crystal display element. It is preferable that it is a grade. If the number of the pixels is too small, the four sides formed along the pixels will be formed in a step shape with a relatively small number of steps, which is substantially from the center of the region separated by a substantially regular hexagonal partition wall. The distance to the six sides of the regular hexagonal partition wall may vary greatly. Further, if the number of the pixels is too large, the distance through which the ferroelectric liquid crystal flows becomes relatively long, which may cause alignment disorder.
For example, in FIG. 5A, 128 pixels 20 are arranged in one substantially regular hexagonal partition wall 4a, and 124 pixels 20 are arranged in one substantially regular hexagonal partition wall 4b. Has been.

  The width of the substantially regular hexagonal partition wall is preferably about 3 μm to 20 μm, more preferably within the range of 5 μm to 10 μm. When the width is wider than the above range, a substantially regular hexagonal partition wall is also provided in the pixel region, and the effective pixel area may be narrowed and a good image display may not be obtained, and the width is narrower than the above range. This is because it may be difficult to form a substantially regular hexagonal partition wall.

  In addition, the height of the substantially regular hexagonal partition wall is usually about the same as the cell gap.

  The distance between two sides parallel to the gate line or the source line of the substantially regular hexagonal partition wall, the number of pixels arranged in one substantially regular hexagonal partition wall, and the width and height of the substantially regular hexagonal partition wall The thickness can be measured by observing a cross section of the substantially regular hexagonal partition wall using a scanning electron microscope (SEM).

  The number of substantially regular hexagonal partition walls is not particularly limited as long as it is plural, and is appropriately selected depending on the size of the liquid crystal display element.

  As a material for forming a substantially regular hexagonal partition wall, a material generally used for a partition wall of a liquid crystal display element can be used. Specifically, examples of the material for forming the substantially regular hexagonal partition walls include resins, and among them, a photosensitive resin is preferably used. This is because the photosensitive resin is easy to pattern.

  Further, the substantially regular hexagonal partition wall only needs to be formed on the first substrate, and the substantially regular hexagonal partition wall 4 may be formed on the first electrode layer 3 as illustrated in FIG. As illustrated in FIG. 6A, a substantially regular hexagonal partition wall 4 may be formed on the first substrate 2. When a substantially regular hexagonal partition wall is formed on the first base material, the substantially regular hexagonal partition wall 4 and the base portion 4 'of the partition wall are integrally formed as illustrated in FIG. 6B. It may be.

(2) First Alignment Film The first alignment film in the present invention is formed on the first electrode layer and the substantially regular hexagonal partition wall.

  The first alignment film is not particularly limited as long as the ferroelectric liquid crystal can be aligned. As illustrated in FIG. 1, the first alignment film 5 is a single-layer alignment film. Also, as illustrated in FIG. 7, the first alignment film 5 is formed on the reactive liquid crystal layer alignment film 5a and the reactive liquid crystal layer alignment film 5a to fix the reactive liquid crystal. The reactive liquid crystal layer 5b may be laminated. Hereinafter, these two aspects will be described separately.

(I) 1st aspect The 1st alignment film of this aspect is a single layer alignment film. The alignment film is not particularly limited as long as the ferroelectric liquid crystal can be aligned, but a rubbing film or a photo alignment film is preferably used.
In general, a ferroelectric liquid crystal having a phase sequence passing through an SmA phase has a chevron structure in which a smectic layer is shrunk in order to compensate for the volume change in the process of phase change, and the smectic layer has a reduced interval. Domains having different major axis directions of liquid crystal molecules are formed depending on the bending direction, and alignment defects called zigzag defects and hairpin defects are likely to occur at the boundary surfaces. In order to prevent the occurrence of zigzag defects and hairpin defects, it is effective to increase the pretilt angle. Generally, the rubbing film can realize a higher pretilt angle than the photo-alignment film. Therefore, the use of the rubbing film can suppress the generation of zigzag defects and hairpin defects.
In addition, the photo-alignment film is a photo-alignment process, and the photo-alignment process is a non-contact alignment process, which is useful in that it does not generate static electricity or dust and can quantitatively control the alignment process. .
Hereinafter, the photo-alignment film and the rubbing film will be described.

(A) Photo-alignment film A photo-alignment film is a film obtained by irradiating a substrate coated with a photo-alignment material, which will be described later, with light whose polarization is controlled to cause photoexcitation reaction (decomposition, isomerization, dimerization). The liquid crystal molecules on the film are aligned by imparting anisotropy to the film.

The photo-alignment material used in the present invention is not particularly limited as long as it has an effect of aligning ferroelectric liquid crystal (photoalignment) by irradiating light and causing a photoexcitation reaction. Absent. Such materials are largely photoreactive materials that impart anisotropy to the photoalignment film by causing photoreactions, and light that imparts anisotropy to the photoalignment film by causing photoisomerization reactions. It can be divided into isomerized materials.
Hereinafter, the photoreactive material and the photoisomerizable material will be described.

(Photoreactive material)
The photoreactive material used in the present invention is not particularly limited as long as it imparts anisotropy to the alignment film by causing a photoreaction, but it causes a photodimerization reaction or a photodecomposition reaction. It is preferable that the alignment film is provided with anisotropy.

  Here, the photodimerization reaction refers to a reaction in which reaction sites aligned in the polarization direction by light irradiation undergo radical polymerization and two molecules are polymerized. This reaction stabilizes the alignment in the polarization direction and is anisotropic to the alignment film. It is possible to impart sex. The photodegradation reaction is a reaction that decomposes molecular chains such as polyimide oriented in the polarization direction by light irradiation. This reaction leaves molecular chains oriented in the direction perpendicular to the polarization direction, and is anisotropic to the alignment film. It is possible to impart sex. Among them, it is more preferable to use a photodimerization-type material that imparts anisotropy to the alignment film by a photodimerization reaction because of high exposure sensitivity and a wide range of material selection.

  The photodimerization type material is not particularly limited as long as it can impart anisotropy to the alignment film by a photodimerization reaction, but has a radical polymerizable functional group and has a polarization direction. It is preferable to contain a photodimerization reactive compound having dichroism with different absorption. 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 orientation film.

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

  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 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 alignment film. On the other hand, if it is too large, the viscosity of the coating liquid at the time of forming the first alignment film increases, and it may be difficult to form a uniform coating film.

  An example of the dimerization reactive polymer is a compound represented by the following formula (1).

In the above formula (1), M ¹¹ and M ¹² 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 ¹² 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 ^1- (Z ¹ -B ¹ ) _z -Z ^2- , and R ² is represented by -A ^1- (Z ¹ -B ¹ ) _z -Z ^3-. It is a group. Here, A ¹ and B ¹ are each independently a covalent single bond, pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,4-cyclohexylene, 1,3-dioxane-2, It represents 5-diyl or 1,4-phenylene which may have a substituent. 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, cinnamoyl group and the like. j and k are each independently 0 or 1.

  Specific examples of such a dimerization reactive polymer include compounds represented by the following formulas (2) to (5).

  More specific examples of the dimerization reactive polymer include compounds represented by the following formulas (6) to (9).

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

  Further, the photodimerization type material may contain an additive in addition to the photodimerization reactive compound as long as the photoalignment of the alignment film is not hindered. 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 mass to 20% by mass, and in the range of 0.1% by mass to 5% by mass with respect to the photodimerization reactive compound. It is more preferable that This is because if the addition amount of the polymerization initiator or polymerization inhibitor is too small, the polymerization may not be started (prohibited), whereas if too large, the reaction may be inhibited.

  On the other hand, examples of the photodecomposable material utilizing a photodecomposition reaction include polyimide “RN1199” manufactured by Nissan Chemical Industries, Ltd.

  The wavelength region of light that causes photoreaction of the photoreactive material is preferably in the range of ultraviolet light, that is, in the range of 10 nm to 400 nm, and more preferably in the range of 250 nm to 380 nm.

  The thickness of the photo-alignment film using the photoreactive material is preferably in the range of 1 nm to 1000 nm, more preferably in the range of 3 nm to 100 nm. If the thickness of the photo-alignment film is smaller than the above range, sufficient optical alignment may not be obtained. Conversely, if the thickness of the photo-alignment film is larger than the above range, the cost may be disadvantageous. is there.

(Photoisomerization type material)
The photoisomerization type material used in the present invention is not particularly limited as long as it imparts anisotropy to the alignment film by causing a photoisomerization reaction, but it causes a photoisomerization reaction. It is preferable that it contains a photoisomerization reactive compound that imparts anisotropy to the alignment film. By including such a photoisomerization-reactive compound, a stable isomer among a plurality of isomers is increased by light irradiation, whereby anisotropy can be easily imparted to the alignment film. is there.

  The 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 can be irradiated by light irradiation. It is preferable that it causes an isomerization reaction. This is because anisotropy can be easily imparted to the alignment film by causing isomerization of the reaction site oriented in the polarization direction of the photoisomerization reactive compound having such characteristics.

  Further, the photoisomerization reaction in which the photoisomerization reactive compound is generated is preferably a cis-trans isomerization reaction. This is because isomers of either the cis form or the trans form are increased by light irradiation, whereby anisotropy can be imparted to the 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. However, it is possible to stabilize the anisotropy by polymerizing after imparting anisotropy to the alignment film by light irradiation. Since it can be performed, 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 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 alignment film due to polymerization becomes more stable, it is a bifunctional monomer. Preferably there is.

  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 contains 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 alignment film becomes larger, and it is particularly suitable for controlling the alignment of ferroelectric liquid crystals. Because it becomes. In this case, the aromatic hydrocarbon group or bonding group contained in the molecule is contained in the side chain together with the cis-trans isomerization reactive skeleton so that the interaction with the liquid crystal molecule is enhanced. It is preferable.

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

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

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

  Since the cis isomer of the azobenzene skeleton is chemically unstable compared to the trans isomer, it thermally or absorbs visible light and returns to the trans isomer. Whether to become the right transformer body occurs with the same probability. Therefore, if the ultraviolet light is continuously absorbed, the ratio of the right-side trans isomer increases, and the average orientation direction of the azobenzene skeleton becomes perpendicular to the polarization direction of the ultraviolet light. In the present invention, by utilizing this phenomenon, the alignment direction of the azobenzene skeleton can be aligned, anisotropy can be imparted to the 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 a compound represented by the following formula (10).

In the above formula (10), R ⁴¹ each independently represents a hydroxy group. R ⁴² is _{^{- (A 41 -B 41 -A 41}} ) m - (D 41) n - represents a linking group represented ^{by, R 43} is _{^{(D 41) n - (A}} 41 -B 41 -A 41) _m represents a linking group represented by-. Here, A ⁴¹ represents a divalent hydrocarbon group, B ⁴¹ represents —O—, —COO—, —OCO—, —CONH—, —NHCO—, —NHCOO— or —OCONH—, and m represents Represents an integer of 0 to 3; D ⁴¹ 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 ⁴⁴ 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 ⁴⁵ 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 formula (10) include compounds represented by the following formulas (11) to (14).

  Examples of the polymerizable monomer having an azobenzene skeleton as a side chain include compounds represented by the following formula (15).

In the above formula (15), each R ⁵¹ is independently (meth) acryloyloxy group, (meth) acrylamide group, vinyloxy group, vinyloxycarbonyl group, vinyliminocarbonyl group, vinyliminocarbonyloxy group, vinyl group, An isopropenyloxy group, an isopropenyloxycarbonyl group, an isopropenyliminocarbonyl group, an isopropenyliminocarbonyloxy group, an isopropenyl group, or an epoxy group is represented. R ⁵² is _{^{- (A 51 -B 51 -A 51}} ) m - (D 51) n - represents a linking group represented ^{by, R 53} is _{^{(D 51) n - (A}} 51 -B 51 -A 51) _m represents a linking group represented by-. Here, A ⁵¹ represents a divalent hydrocarbon group, B ⁵¹ represents —O—, —COO—, —OCO—, —CONH—, —NHCO—, —NHCOO— or —OCONH—, and m represents Represents an integer of 0 to 3; D ⁵¹ represents a divalent hydrocarbon group when m is 0, and when m is an integer of 1 to 3, —O—, —COO—, —OCO—, —CONH—, —NHCO—, —NHCOO— Alternatively, -OCONH- is represented, and n represents 0 or 1. R ⁵⁴ 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 ⁵⁵ 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 formula (15) include compounds represented by the following formulas (16) to (19).

  In the present invention, various cis-trans isomerization reactive skeletons and substituents can be selected from such photoisomerization reactive compounds according to required characteristics. In addition, these photoisomerization reactive compounds 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 may contain an additive within a range that does not interfere with the photoalignment of the alignment 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 polymerization inhibitor is preferably in the range of 0.001% by mass to 20% by mass, and in the range of 0.1% by mass to 5% by mass with respect to the photoisomerization reactive compound. More preferably, it is within. This is because if the addition amount of the polymerization initiator or polymerization inhibitor is too small, the polymerization may not be started (prohibited), whereas if too large, the reaction may be inhibited.

  The wavelength region of the light that causes the photoisomerization reaction of the photoisomerizable material is preferably in the ultraviolet light range, that is, in the range of 10 nm to 400 nm, and more preferably in the range of 250 nm to 380 nm. .

  The thickness of the photo-alignment film using the photoisomerizable material is preferably in the range of 1 nm to 1000 nm, more preferably in the range of 3 nm to 100 nm. If the thickness of the photo-alignment film is smaller than the above range, sufficient optical alignment may not be obtained. Conversely, if the thickness of the photo-alignment film is larger than the above range, the cost may be disadvantageous. is there.

(B) Rubbing film A rubbing film is a film in which a substrate coated with a material to be described later is subjected to a rubbing treatment, and anisotropy is imparted to the obtained film to align liquid crystal molecules on the film.

  The material used for the rubbing film is not particularly limited as long as anisotropy can be imparted by rubbing treatment. For example, polyimide, polyamide, polyamideimide, polyetherimide, polyvinyl alcohol, polyurethane, etc. Can be mentioned. These may be used alone or in combination of two or more.

  Further, the thickness of the rubbing film is set to about 1 nm to 1000 nm, and preferably in the range of 50 nm to 100 nm.

(Ii) Second Aspect The first alignment film of this aspect includes a reactive liquid crystal layer alignment film, a reactive liquid crystal layer formed on the reactive liquid crystal layer alignment film, and formed by immobilizing reactive liquid crystals. Are laminated. When forming the reactive liquid crystal layer on the alignment layer for the reactive liquid crystal layer, the reactive liquid crystal layer is aligned by the alignment layer for the reactive liquid crystal layer, and the reaction is performed by, for example, irradiating ultraviolet rays to polymerize the reactive liquid crystal. The alignment state of the conductive liquid crystal can be fixed. Therefore, the alignment regulating force of the alignment film for the reactive liquid crystal layer can be imparted to the reactive liquid crystal layer, and the reactive liquid crystal layer can act as an alignment film for aligning the ferroelectric liquid crystal. Further, since the reactive liquid crystal is fixed, it has an advantage that it is not affected by temperature or the like. In addition, reactive liquid crystals are relatively similar in structure to ferroelectric liquid crystals, and interact more strongly with ferroelectric liquid crystals, so that ferroelectrics are more effective than using single-layer alignment films. The orientation of the crystalline liquid crystal can be controlled.

  In addition, about the alignment film for reactive liquid crystal layers, since it is the same as that of the alignment film as described in the said 1st aspect, description here is abbreviate | omitted.

  The reactive liquid crystal used in the present invention preferably exhibits a nematic phase. This is because the nematic phase is relatively easy to control the alignment among the liquid crystal phases.

  The reactive liquid crystal preferably contains a polymerizable liquid crystal material. This is because 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, and among them, 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.

  Examples of the monoacrylate monomer include compounds represented by the following formulas (20) and (21).

In the above formulas (20) and (21), 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 shown, for example in following formula (22) can be mentioned.

In the above formula (22), Z ³¹ and Z ³² 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 —, wherein R ³¹ , R ³² and R ³³ each independently represent hydrogen or carbon number Represents 1-5 alkyl. K and m represent 0 or 1, and n represents an integer in the range of 2 to 8. R ³¹ , R ³² and R ³³ are each independently alkyl having 1 to 5 carbons when k = 1, and each independently being hydrogen or alkyl having 1 to 5 carbons when k = 0. Preferably there is. R ³¹ , R ³² and R ³³ may be the same as each other.

  Specific examples of the compound represented by the above formula (22) include a compound represented by the following formula (23).

In the above formula (23), Z ²¹ and Z ²² are each independently directly bonded —COO—, —OCO—, —O—, —CH ₂ CH ₂ —, —CH═CH—, —C Represents ≡C—, —OCH ₂ —, —CH ₂ O—, —CH ₂ CH ₂ COO—, —OCOCH ₂ CH ₂ —. M represents 0 or 1, and n represents an integer in the range of 2-8.

  Examples of the diacrylate monomer also include compounds represented by the following formulas (24) and (25).

In the above formulas (24) and (25), X and Y are hydrogen, alkyl having 1 to 20 carbons, alkenyl having 1 to 20 carbons, alkyloxy having 1 to 20 carbons, or alkyl having 1 to 20 carbons. It represents oxycarbonyl, formyl, alkylcarbonyl having 1 to 20 carbons, alkylcarbonyloxy having 1 to 20 carbons, halogen, cyano or nitro. M represents an integer in the range of 2-20. Further, X is preferably alkyloxycarbonyl having 1 to 20 carbon atoms, methyl or chlorine, and particularly preferably alkyloxycarbonyl having 1 to 20 carbon atoms, particularly CH ₃ (CH ₂ ) ₄ OCO.

  Among these, compounds represented by the above formulas (22) and (24) are preferably used. In particular, the compound represented by the above formula (24) is preferred. Specific examples include “Adeka Kiracol PLC-7183”, “Adeka Kiracol PLC-7209”, and “Adeka Kiracol PLC-7218” manufactured by Asahi Denka Kogyo Co., Ltd.

  Of the polymerizable liquid crystal monomers, diacrylate monomers are preferred. 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 may not be one that exhibits a nematic phase. These polymerizable liquid crystal monomers may be used as a mixture of two or more kinds as described above, because the composition in which these are mixed, that is, the reactive liquid crystal may exhibit a nematic phase. It is.

  Furthermore, you may add a photoinitiator, a polymerization inhibitor, etc. 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. An agent is used to promote polymerization.

  Examples of the photopolymerization initiator include benzyl (also called bibenzoyl), benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-benzoyl-4'-methyldiphenyl sulfide, benzylmethyl ketal, Dimethylaminomethyl benzoate, 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, 1- (4-dodecyl) Phenyl) 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 do. In addition to the photopolymerization initiator, it is also possible to add a sensitizer as long as the object of the present invention is not impaired.

  Moreover, as addition amount of a photoinitiator, it adds to the said reactive liquid crystal in the range of about 0.01-20 mass%, Preferably it is 0.1-10 mass%, More preferably, it is 0.5-5 mass%. can do.

  The thickness of the reactive liquid crystal layer is appropriately adjusted according to the target anisotropy, and can be set, for example, within a range of 1 nm to 1000 nm, and preferably within a range of 3 nm to 100 nm. This is because if the reactive liquid crystal layer is too thick, anisotropy more than necessary occurs, and if the reactive liquid crystal layer is too thin, the predetermined anisotropy may not be obtained.

(3) 1st electrode layer The 1st electrode layer in this invention is formed on a 1st base material.
The first electrode layer used in the present invention is not particularly limited as long as it is generally used as an electrode of a liquid crystal display element, but the first electrode layer and the second alignment treatment of the first alignment treatment substrate. It is preferable that at least one of the second electrode layers of the substrate is formed of a transparent conductor. 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 obtained by the present invention is driven by an active matrix system using TFTs, one of the first alignment processing substrate and the second alignment processing substrate is formed on the entire surface formed of the transparent conductor. An electrode is provided, and on the other side, a gate line and a source line are arranged in a matrix, and a TFT element and a pixel electrode are provided in a portion surrounded by the gate line and the source line.

  Examples of the method for forming the first electrode layer include chemical vapor deposition (CVD), physical vapor deposition (PVD) such as sputtering, ion plating, and vacuum deposition.

(4) 1st base material The 1st base material used for this invention will not be specifically limited if generally used as a base material of a liquid crystal display element, For example, a glass plate, a plastic plate, etc. are preferable. Can be mentioned.

(5) Other configurations In the present invention, a colored layer may be formed on the first substrate. When the colored layer is formed on the second base material, the first alignment processing substrate does not have the colored layer. That is, the first alignment treatment substrate may have a colored layer, and the second alignment treatment substrate may have a coloring layer.
When the colored layer is formed, a color filter type liquid crystal display element capable of realizing color display by the colored layer can be obtained.

  As a method for forming the colored layer, a method for forming a colored layer in a general color filter can be used. For example, a pigment dispersion method (color resist method, etching method), a printing method, an inkjet method, or the like can be used. it can.

  Moreover, in this invention, the frame-shaped partition may be formed in the peripheral part of the 1st base material so that the outer periphery of a several substantially regular hexagonal partition may be enclosed. When producing the liquid crystal display element of this invention, it becomes easy to apply | coat a sealing compound along a frame-shaped partition to a 1st alignment processing board | substrate.

2. Ferroelectric liquid crystal In the present invention, a ferroelectric liquid crystal is sandwiched between a first alignment film of a first alignment treatment substrate and a second alignment film of a second alignment treatment substrate, thereby forming a liquid crystal layer. .

Ferroelectric liquid crystal used in the present invention is not limited in particular as long as it expresses a chiral smectic C phase (SmC ^*). For example, the phase sequence changes in phase with a nematic phase (N) -cholesteric phase (Ch) -chiral smectic C phase (SmC ^* ) in the temperature lowering process, or a nematic phase (N) -chiral smectic C phase (SmC ^* ). , Nematic phase (N) -smectic A phase (SmA) -chiral smectic C phase (SmC ^* ), phase change, nematic phase (N) -cholesteric phase (Ch) -smectic A phase (SmA ) -Chiral smectic C phase (SmC ^* ) and the like.

  When the liquid crystal display element of the present invention is driven by a field sequential color system, it is preferable to use a liquid crystal material exhibiting monostability. By using a liquid crystal material exhibiting monostability, it becomes possible to drive by an active matrix method using thin film transistors (TFTs), and to control gradation by voltage modulation, so that high-definition and high-quality display can be achieved. This is because it can be realized.

  As illustrated in FIG. 8, the ferroelectric liquid crystal rotates along a cone ridge line in which the liquid crystal molecules 30 are inclined from the layer normal z and have a bottom surface perpendicular to the layer normal z. In such a cone, the tilt angle of the liquid crystal molecules 30 with respect to the layer normal z is referred to as a tilt angle θ.

  “Showing monostability” means a state in which the state of the ferroelectric liquid crystal when no voltage is applied is stabilized in one state. More specifically, as shown in FIG. 8, the liquid crystal molecules 30 can operate on a cone between two states tilted by a tilt angle ± θ with respect to the layer normal z. The state 30 is stabilized in any one state on the cone.

Among liquid crystal materials exhibiting monostability, for example, as shown in the lower left of FIG. 9, liquid crystal molecules operate only when a positive or negative voltage is applied, and half-V shaped switching (hereinafter referred to as half-V shaped switching). That exhibit properties are particularly preferred. Using a ferroelectric liquid crystal exhibiting such a half V-shaped switching characteristic, it is possible to take a sufficiently long opening time as a black and white shutter, thereby making it possible to display each color that is temporally switched brighter. This is because a bright color display liquid crystal display element can be realized.
The “half V-shaped switching characteristic” refers to an electro-optical characteristic in which the light transmittance with respect to an applied voltage is asymmetric.

  Such a ferroelectric liquid crystal can be variously selected from generally known liquid crystal materials according to required characteristics.

In particular, a liquid crystal material that exhibits an SmC ^* phase from the Ch phase without passing through the SmA phase is suitable as a material that exhibits a half V-shaped switching characteristic. Specifically, “R2301” manufactured by AZ Electronic Materials may be mentioned.

In addition, as the liquid crystal material that passes through the SmA phase, a material that expresses the SmC ^* phase from the Ch phase through the SmA phase is preferable because of a wide range of material selection. In this case, a single liquid crystal material exhibiting an SmC ^* phase can be used, but a non-chiral liquid crystal (hereinafter sometimes referred to as a host liquid crystal) having a low viscosity and easily exhibiting an SmC phase is used. By adding a small amount of an optically active substance that does not show large spontaneous polarization and an appropriate helical pitch, the liquid crystal material showing the phase sequence as described above has low viscosity and can realize faster response. preferable.

The host liquid crystal is preferably a material exhibiting an SmC phase in a wide temperature range, and can be used without particular limitation as long as it is generally known as a host liquid crystal of a ferroelectric liquid crystal. For example, the general formula:
^{Ra-Q 1 -X 1 - (} Q 2 -Y 1) m -Q 3 -Rb
(In the formula, Ra and Rb are each a linear or branched alkyl group, alkoxy group, alkoxycarbonyl group, alkanoyloxy group or alkoxycarbonyloxy group, and Q ¹ , Q ² and Q ³ are each 1 , 4-phenylene group, 1,4-cyclohexylene group, pyridine-2,5-diyl group, pyrazine-2,5-diyl group, pyridazine-3,6-diyl group, 1,3-dioxane-2,5 -Diyl group, and these groups may have a substituent such as a halogen atom, a hydroxyl group, and a cyano group, and X ¹ and Y ¹ are each —COO—, —OCO—, —CH ₂ O— , —OCH ₂ —, —CH ₂ CH ₂ —, —C≡C—, or a single bond, and m is 0 or 1.). As the host liquid crystal, the above compounds can be used alone or in combination of two or more.

The optically active substance added to the host liquid crystal is not particularly limited as long as it is a material having a large spontaneous polarization and the ability to induce an appropriate helical pitch, and is generally added to a liquid crystal composition exhibiting an SmC phase. Any known material can be used. In particular, a material that can induce large spontaneous polarization with a small addition amount is preferable. Examples of such an optically active substance include the following general formula:
^{Rc-Q 1 -Za-Q 2} -Zb-Q 3 -Zc-Rd
(In the formula, Q ¹ , Q ² and Q ³ represent the same meaning as in the above general formula, and Za, Zb and Zc are —COO—, —OCO—, —CH ₂ O—, —OCH ₂ —, —CH _{2, respectively.} CH ₂ —, —C≡C—, —CH═N—, —N═N—, —N (→ O) ═N—, —C (═O) S— or a single bond, and Rc is asymmetric. A linear or branched alkyl group which may have a carbon atom, an alkoxy group, an alkoxycarbonyl group, an alkanoyloxy group or an alkoxycarbonyloxy group, wherein Rd is a linear or branched group having an asymmetric carbon atom; And an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkanoyloxy group or an alkoxycarbonyloxy group, and Rc and Rd may be substituted with a halogen atom, a cyano group or a hydroxyl group. Can be used. As the optically active substance, the above compounds may be used alone or in combination of two or more.

  Specific examples of the ferroelectric liquid crystal passing through the SmA phase include “FELIXM4851-100” manufactured by AZ Electronic Materials.

  In addition to the ferroelectric liquid crystal, the liquid crystal layer may contain a compound having any function depending on the function required for the liquid crystal display element. Examples of the compound include a polymerized polymerizable monomer. By containing such a polymerizable monomer polymer in the liquid crystal layer, the alignment of the liquid crystal material is so-called “polymer stabilization”, and a liquid crystal display device excellent in alignment stability can be obtained.

  The polymerizable monomer used in the polymerized polymer of the polymerizable monomer is not particularly limited as long as it is a compound that generates a polymer by a polymerization reaction, and a thermosetting resin monomer that generates a polymerization reaction by heat treatment, and actinic radiation. An actinic radiation curable resin monomer that undergoes a polymerization reaction upon irradiation of can be exemplified. Among these, it is preferable to use an actinic radiation curable resin monomer. When a thermosetting resin monomer is used, it is necessary to perform a heating process in order to cause a polymerization reaction. Therefore, the regular arrangement of the ferroelectric liquid crystal is impaired by such a heating process, There is a risk of inducing a phase transition. On the other hand, when the actinic radiation curable resin monomer is used, there is no such fear, and the alignment of the ferroelectric liquid crystal is hardly harmed 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 that undergoes a polymerization reaction upon irradiation with light. Among these, it is preferable to use a photocurable resin monomer. It is because a manufacturing process can be simplified by using a photocurable resin monomer.

  The photocurable 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. Among them, it is preferable to use an ultraviolet curable resin monomer that generates 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 upon irradiation with ultraviolet rays in the above wavelength region. In particular, it is preferable to use an ultraviolet curable resin monomer having an acrylate group.

  Further, the UV curable resin monomer may be a monofunctional monomer having one polymerizable functional group in one molecule, or a polyfunctional having two or more polymerizable functional groups in one molecule. It may be a monomer. Among these, it is preferable to use a polyfunctional monomer. By using a polyfunctional monomer, a stronger polymer network can be formed, so that the intermolecular force and the polymer network at the alignment film interface can be strengthened. Thereby, the disorder of the alignment of the ferroelectric liquid crystal due to the temperature change can be suppressed.

  Among the polyfunctional monomers, bifunctional monomers having a polymerizable functional group at both ends of the molecule are preferably used. By having a polymerizable functional group at both ends of the molecule, it is possible to form a polymer network with a wide interval between polymers, and to prevent a decrease in driving voltage of the ferroelectric liquid crystal due to the inclusion of a polymer of a polymerizable monomer. Because.

  Of the ultraviolet curable resin monomers, it is preferable to use an ultraviolet curable liquid crystal monomer that exhibits liquid crystallinity. The reason why such an ultraviolet curable liquid crystal monomer is preferable is as follows. That is, since the ultraviolet curable liquid crystal monomer exhibits liquid crystallinity, it can be regularly arranged by the alignment regulating force of the alignment film. For this reason, the ultraviolet curable liquid crystal monomer can be fixed while maintaining the regular alignment state by causing a polymerization reaction after the ultraviolet light curable liquid crystal monomer is regularly arranged. By the presence of the polymer having such a regular alignment state, the alignment stability of the ferroelectric liquid crystal can be improved, and excellent heat resistance and impact resistance can be obtained.

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

  Examples of the ultraviolet curable liquid crystal monomer used in the present invention include compounds represented by the following formulas (20), (21), and (25).

In the above formulas (20) and (21), 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. Further, the acryloyloxy group at the end of the molecular chain and A or D may be bonded via a bonding group such as an alkylene group having 3 to 6 carbon atoms.

  In the above formula (25), Y is 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, It represents formyl, alkylcarbonyl having 1 to 20 carbons, alkylcarbonyloxy having 1 to 20 carbons, halogen, cyano or nitro.

  Among the above, the compounds represented by the following formulas can be exemplified as those suitably used.

  Moreover, the said polymerizable monomer may be used independently and may be used in combination of 2 or more type. When two or more different polymerizable monomers are used, for example, an ultraviolet curable liquid crystal monomer represented by the above formula and another ultraviolet curable resin monomer can be used.

  When an ultraviolet curable liquid crystal monomer is used as the polymerizable monomer, the polymer of the polymerizable monomer is a main chain liquid crystal type polymer in which the main chain exhibits liquid crystallinity by having an atomic group exhibiting liquid crystallinity in the main chain. It 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. Especially, it is preferable that the polymer of a polymerizable monomer is a side chain liquid crystal type polymer. 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. Further, as a result, the alignment stability of the ferroelectric liquid crystal can be improved.

The amount of the polymerized monomer in the liquid crystal layer is not particularly limited as long as the alignment stability of the ferroelectric liquid crystal is within a desired range, but usually 0.5% by mass in the liquid crystal layer. It is preferably within the range of ˜30% by mass, more preferably within the range of 1% by mass to 20% by mass, and even more preferably within the range of 1% by mass to 10% by mass. This is because if it exceeds the above range, the drive voltage may increase or the response speed may decrease. Further, 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 may be impaired.
The abundance of the polymerizable monomer polymer in the liquid crystal layer is obtained by washing the monomolecular liquid crystal in the liquid crystal layer with a solvent and then measuring the weight of the remaining polymerizable monomer polymer with an electronic balance. It can be calculated from the remaining amount and the total mass of the liquid crystal layer.

  The thickness of the liquid crystal layer is preferably in the range of 1.2 μm to 3.0 μm, more preferably 1.3 μm to 2.5 μm, and still more preferably in the range of 1.4 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. The thickness of the liquid crystal layer can be adjusted by a substantially regular hexagonal partition wall.

3. Second Alignment Processed Substrate The second alignment process substrate in the present invention includes a second base material, a second electrode layer formed on the second base material, and a second orientation formed on the second electrode layer. And a film.
The second base material, the second electrode layer, and the second alignment film are the same as the first base material, the first electrode layer, and the first alignment film in the first alignment processing substrate, respectively. Description is omitted.
Hereinafter, the composition of the constituent materials of the first alignment film and the second alignment film will be described.

(1) Composition of constituent materials of first alignment film and second alignment film The combination of materials used for the first alignment film and the second alignment film is not particularly limited. It is preferable that the constituent material of the second alignment film has a composition different from each other across the ferroelectric liquid crystal. By forming the first alignment film and the second alignment film using materials having different compositions, the polarities of the first alignment film surface and the second alignment film surface can be made different depending on the respective materials. As a result, the polar surface interaction between the ferroelectric liquid crystal and the first alignment film is different from the polar surface interaction between the ferroelectric liquid crystal and the second alignment film, so that the first alignment film and the second alignment film This is because the generation of alignment defects such as zigzag defects, hairpin defects, double domains, and the like can be suppressed by appropriately selecting materials in consideration of the surface polarity.

  In general, a ferroelectric liquid crystal having a phase sequence via an SmA phase as illustrated in the lower part of FIG. 10 has a smectic layer in order to compensate for the volume change because the layer spacing of the smectic layer is reduced during the phase change process. A domain having a bent chevron structure and different major axis directions of the liquid crystal molecules is formed depending on the bending direction, and alignment defects called zigzag defects and hairpin defects are likely to occur at the interface. In general, a ferroelectric liquid crystal having a phase sequence that does not pass through the SmA phase as exemplified in the upper part of FIG. 10 is likely to generate two regions (double domains) having different layer normal directions. By making the constituent materials of the first alignment film and the second alignment film have compositions different from each other with the ferroelectric liquid crystal in between, the occurrence of such alignment defects can be suppressed. In particular, the occurrence of double domains can be effectively suppressed, and monodomain orientation can be obtained.

  In order to make the composition of the constituent materials of the first alignment film and the second alignment film different, for example, one is a photo-alignment film and the other is a rubbing film, or one is reactive with an alignment film for a reactive liquid crystal layer. A layered liquid crystal layer and the other may be a photo-alignment film or a rubbing film. In addition, both are rubbed films, the composition of the constituent materials of the rubbing film are different, or both are the photo-alignment films, and the composition of the constituent materials of the photo-alignment film is different, or both are reactive. The composition of the constituent material of the first alignment film and the second alignment film is made different by making the composition of the constituent material of the reactive liquid crystal layer different from that of the alignment film for the liquid crystal layer and the reactive liquid crystal layer. Can be different.

  Further, when the first alignment film and the second alignment film are photo-alignment films, for example, by using a photoisomerizable material for one photo-alignment film and a photo-reactive material for the other photo-alignment film, The composition of the constituent material of the alignment film can be different.

  Furthermore, when the first alignment film and the second alignment film are photo-alignment films using a photoisomerization type material, cis-trans isomerization is selected from the above-mentioned photoisomerization-reactive compounds according to required characteristics. The composition of the constituent material of the photo-alignment film can be made different by selecting various reactive skeletons and substituents. Furthermore, the composition can be changed by changing the amount of the additive described above.

  Furthermore, when the first alignment film and the second alignment film are photo-alignment films using a photoreactive material, the photo-dimerization reactive compound, for example, the photo-dimerization-reactive polymer, can be selected by various selection. The composition of the constituent materials of the film can be different. Furthermore, the composition can be changed by changing the amount of the additive described above.

  As a combination of materials used for the first alignment film and the second alignment film, among the above, one of the alignment films for the reactive liquid crystal layer and the reactive liquid crystal layer is laminated, and the other is the photo alignment film or Either a rubbing film, or a photo-alignment film using a photo-dimerization material and one using a photo-alignment film using a photo-isomerization material, or a photo-alignment film using a photo-dimerization material. It is preferable to use a film and the other as a rubbing film, or one as a photo-alignment film using a photoisomerizable material and the other as a rubbing film. The reactive liquid crystal layer tends to have a stronger positive polarity than the photo-alignment film or the rubbing film. Therefore, in the case of this combination, the negative electrode of the spontaneous polarization of the ferroelectric liquid crystal tends to face the reactive liquid crystal layer side due to the polar surface interaction. In addition, a photo-alignment film using a photodimerization type material tends to have a relatively positive polarity compared to a photo-alignment film using a photoisomerization type material. Due to the action, the negative polarity of the spontaneous polarization of the ferroelectric liquid crystal tends to face the photo-alignment film side using the photodimerization type material. Furthermore, since photo-alignment films using photo-dimerization materials tend to have a relatively positive polarity compared to rubbing films, the negative polarity of spontaneous polarization of ferroelectric liquid crystals is caused by photo-dimerization due to the polar surface interaction. It tends to face the photo-alignment film side using the material. Also, the rubbing film tends to have a relatively positive polarity relative to the photo-alignment film using the photoisomerization type material. Therefore, the negative polarity of the spontaneous polarization of the ferroelectric liquid crystal is caused by the polar surface interaction. It tends to turn to the side. In the case of such a combination, the direction of spontaneous polarization of the ferroelectric liquid crystal can be controlled, and the occurrence of alignment defects can be effectively suppressed.

In particular, the first alignment film is a laminate of an alignment film for a reactive liquid crystal layer and a reactive liquid crystal layer, and the second alignment film is a photo-alignment film or a rubbing film, or the first alignment film is photodimerized. A photo-alignment film using a mold material and a second alignment film as a photo-alignment film using a photoisomerization-type material, or a first alignment film as a photo-alignment film using a photo-dimerization-type material, Preferably, the alignment film is a rubbing film, or the first alignment film is a rubbing film and the second alignment film is a photo-alignment film using a photoisomerizable material.
When manufacturing the liquid crystal display element of the present invention, when the ferroelectric liquid crystal is dropped on the region separated by the substantially regular hexagonal partition wall, the ferroelectric liquid crystal is formed on the first alignment film of the first alignment processing substrate. Will be dripped. Thus, in the liquid crystal display device obtained by the liquid crystal dropping method, the negative electrode of the spontaneous polarization of the ferroelectric liquid crystal tends to face the substrate side on which the ferroelectric liquid crystal is dropped. Further, as described above, the reactive liquid crystal layer tends to have a relatively strong positive polarity than the photo-alignment film or the rubbing film, and the photo-alignment film using the photo-dimerization type material is a photo-isomerization type material. There is a tendency that the positive polarity is relatively stronger than that of the photo-alignment film using the photo-alignment, and the photo-alignment film using the photo-dimerization type material tends to have a relatively positive polarity rather than the rubbing film. Tends to have a relatively stronger positive polarity than a photo-alignment film using a photoisomerizable material. Therefore, in order to effectively suppress alignment defects, it is preferable that the combination of materials used for the first alignment film and the second alignment film is as described above.

4). Other Configurations The liquid crystal display element of the present invention may have polarizing plates outside the first alignment treatment substrate and the second alignment treatment substrate.
The polarizing plate used in the present invention is not particularly limited as long as it transmits only a specific direction among the wave of light, and a polarizing plate generally used as a polarizing plate of a liquid crystal display element should be used. Can do.

5). Method for Driving Liquid Crystal Display Element As a method for driving the liquid crystal display element of the present invention, the high-speed response of ferroelectric liquid crystal can be used. A field sequential color system that particularly requires high-speed response is suitable.

  The driving method of the liquid crystal display element is not limited to the field sequential method, and may be a color filter method that performs color display using a colored layer.

  Furthermore, as a driving method of the liquid crystal display element, an active matrix system using a thin film transistor (TFT) is preferable. This is because by adopting an active matrix system using TFTs, the target pixel can be reliably turned on and off, and a high-quality display becomes possible.

  FIG. 11 shows an example of an active matrix liquid crystal display element using TFTs. The liquid crystal display element 1 illustrated in FIG. 11 includes a TFT substrate (first alignment treatment substrate 6) on which a TFT element 23t is disposed on a first base material 2, and a common electrode (second electrode) on the second base material 12. Layer 13) and a common electrode substrate (second alignment treatment substrate 16) on which the second alignment film 15 is formed. A gate line 23x, a source line 23y, a TFT element 23t, and a pixel electrode 23p (first electrode layer 3) are formed on the TFT substrate (first alignment processing substrate 6). The gate line 23x and the source line 23y are arranged vertically and horizontally, respectively, and by applying a signal to the gate line 23x and the source line 23y, the TFT element 23t can be operated to drive the ferroelectric liquid crystal. A portion where the gate line 23x and the source line 23y intersect with each other is insulated by an insulating layer (not shown), and the signal on the gate line 23x and the signal on the source line 23y can operate independently. A portion surrounded by the gate line 23x and the source line 23y is a pixel 20 which is a minimum unit for driving the liquid crystal display element. Each pixel 20 includes at least one TFT element 23t and a pixel electrode 23p (first electrode). Layer 3) is formed. Then, by sequentially applying a signal voltage to the gate line and the source line, the TFT element of each pixel can be operated. In FIG. 11, the substantially regular hexagonal partition walls, the first alignment film, and the liquid crystal layer are omitted.

  In the above example, the first alignment processing substrate is a TFT substrate and the second alignment processing substrate is a common electrode substrate. However, the present invention is not limited to this, and the first alignment processing substrate is a common electrode substrate. The second alignment processing substrate may be a TFT substrate. When the second alignment treatment substrate is a TFT substrate, substantially regular hexagonal partitions are arranged on the first alignment treatment substrate in accordance with the arrangement of the gate lines and the source lines formed on the second alignment treatment substrate.

  The driving method of the liquid crystal display element may be a segment method.

B. Next, a method for manufacturing a liquid crystal display element of the present invention will be described.
In the method for producing a liquid crystal display element of the present invention, a plurality of substantially regular hexagonal partition walls are formed on a first substrate, two sides of the approximately regular hexagonal partition walls are parallel to the gate lines or source lines, and the four sides are the above. A partition forming step of forming a honeycomb shape so as to intersect with the gate line and the source line and so that four sides intersecting with the gate line and the source line are arranged stepwise along the pixel; A first alignment film forming step of forming a first alignment film on the first substrate on which the electrode layer and the substantially regular hexagonal partition wall are formed, wherein the first electrode layer and the approximately regular hexagon are formed on the first substrate; A first alignment treatment substrate preparation step for preparing a first alignment treatment substrate on which a shape partition and a first alignment film are formed, and a second alignment in which a second electrode layer and a second alignment film are formed on a second base material Second alignment treatment substrate preparation step for preparing a treatment substrate, and the first alignment treatment group A liquid crystal dropping step of dropping a ferroelectric liquid crystal on a central portion of a region separated by the substantially regular hexagonal partition, and the first alignment in which the ferroelectric liquid crystal is dropped It has a board | substrate bonding process which bonds a process board | substrate and the said 2nd orientation process board | substrate.

The manufacturing method of the liquid crystal display element of this invention is demonstrated referring drawings.
FIG. 12 is a process diagram showing an example of a method for producing a liquid crystal display element of the present invention. Fig.5 (a) is a top view of Fig.12 (a), and the BB sectional view of Fig.5 (a) respond | corresponds to Fig.12 (a). FIG. 13 is a top view of the first alignment processing substrate in FIG. 12D, and a cross section taken along the line CC in FIG. 13 corresponds to the first alignment processing substrate in FIG. Further, FIG. 3 is an enlarged view of a frame D in FIG.

First, as illustrated in FIG. 3, a first base material on which a gate line 23x, a source line 23y, a TFT element 23t, and a pixel electrode 23p (first electrode layer 3) are formed is prepared. Next, as shown in FIG. 12A and FIG. 5A, a photosensitive resin layer is formed on the first base material 2 on which the first electrode layer 3 and the like are formed, and exposed through a photomask. And developing to form substantially regular hexagonal partition walls 4 (partition wall forming step).
Here, in FIG. 5A, the six sides of the substantially regular hexagonal partition wall 4 are defined as s1 to s6 clockwise from above. In the partition wall forming step, as shown in FIGS. 3 and 5A, the substantially regular hexagonal partition wall 4 has two sides s1, s4 parallel to the gate line 23x, and four sides s2, s3, s5, s6 are Four sides s2 intersecting the gate line 23x and the source line 23y, and two sides s1 and s4 parallel to the gate line 23x are linearly arranged along the pixel 20, and intersect the gate line 23x and the source line 23y. , S3, s5, and s6 are arranged along the pixel 20 in a staircase pattern. Then, a plurality of substantially regular hexagonal partition walls 4 are formed in a honeycomb shape.

  Next, as shown in FIG. 12B, the first alignment film 5 is formed on the first electrode layer 3 and the substantially regular hexagonal shape 4 (first alignment film forming step). Thereby, the 1st orientation processing board | substrate 6 is obtained (1st orientation processing board | substrate preparation process).

  Next, as shown in FIG.12 (c), the 2nd alignment film 15 is formed on the 2nd base material 12 in which the 2nd electrode layer 13 was formed (2nd alignment film formation process). Thereby, the 2nd alignment processing board | substrate 16 is obtained (2nd alignment processing board | substrate preparation process).

Next, as shown in FIG. 12D and FIG. 13, a strong force is applied to the central portion 25 of the region 24 on the first alignment film 5 and separated by the substantially regular hexagonal partition walls 4 by using a dispenser. Dielectric liquid crystal 26 is dropped in the form of dots in an isotropic phase (liquid crystal dropping step). At this time, the ferroelectric liquid crystal 26 is dropped in an amount suitable for the region 24.
Next, when the first alignment treatment substrate 6 on which the ferroelectric liquid crystal 26 is dropped is heated to a temperature at which the ferroelectric liquid crystal exhibits an isotropic phase (for example, 110 ° C.), the dropped ferroelectric liquid crystal 26 is As shown in FIG. 4, it spreads in a radial manner in an arbitrary direction. Since the distances from the central portion 25 of the region 24 separated by the substantially regular hexagonal partition wall 4 to the six sides s1 to s6 of the substantially regular hexagonal partition wall 4 are almost equal, the ferroelectric liquid crystal is near the substantially regular hexagonal partition wall. Can be prevented from overflowing from the substantially regular hexagonal partition wall or the flow direction of the ferroelectric liquid crystal being changed. Thereby, it is possible to suppress the occurrence of disorder in the alignment of the ferroelectric liquid crystal near the substantially regular hexagonal partition wall.

  Next, as shown in FIG. 14, a sealing agent 31 is applied to the peripheral edge portion of the first alignment treatment substrate 6 so as to surround the outer periphery of the plurality of substantially regular hexagonal partition walls 4.

  Next, as shown in FIG. 12 (d), the first alignment processing substrate 6 and the second alignment processing substrate 16 onto which the ferroelectric liquid crystal 26 has been dropped are connected to the first alignment film 5 and the second alignment film 15. The alignment treatment directions are made to be substantially parallel to each other.

  Next, as shown in FIG. 12E, the pressure between the first alignment treatment substrate 6 and the second alignment treatment substrate 16 is sufficiently reduced, and the first alignment treatment substrate 6 and the second alignment treatment substrate 16 are reduced under reduced pressure. Overlap and apply a predetermined pressure 32 to make the cell gap uniform. Subsequently, the pressure is further applied between the first alignment processing substrate 6 and the second alignment processing substrate 16 by returning to normal pressure. Next, although not shown, the region to which the sealant is applied is irradiated with ultraviolet rays to cure the sealant, and the first alignment treatment substrate and the second alignment treatment substrate are bonded (substrate bonding step).

  Thereafter, although not shown, the sealed ferroelectric liquid crystal is aligned by slowly cooling to room temperature.

  According to the present invention, a plurality of substantially regular hexagonal partition walls are formed, and then a ferroelectric liquid crystal is dropped on the center of the region separated by the substantially regular hexagonal partition walls, thereby strengthening the region around the substantially regular hexagonal partition wall. It is possible to prevent the dielectric liquid crystal from overflowing from the substantially regular hexagonal partition wall or changing the flow direction of the ferroelectric liquid crystal. Thereby, it is possible to make it difficult to cause disorder in the alignment of the ferroelectric liquid crystal in the vicinity of the substantially regular hexagonal partition wall.

  According to the invention, the substantially regular hexagonal partition wall intersects the gate line and the source line so that the two sides are parallel to the gate line or the source line and the four sides intersect the gate line and the source line. Since the four sides are formed so as to be stepped along the pixel, a substantially regular hexagonal partition wall can be disposed on the gate line and the source line. Thereby, the brightness nonuniformity by a partition can be prevented. In addition, since a substantially regular hexagonal partition wall can be arranged in a non-pixel region that does not affect image display, even if a ferroelectric liquid crystal alignment defect occurs near the substantially regular hexagonal partition wall, image display is possible. Can be minimized.

  Further, according to the present invention, since the plurality of substantially regular hexagonal partition walls are formed in a honeycomb shape, it is possible to drop the ferroelectric liquid crystal in an equal amount in each region separated by the plurality of substantially regular hexagonal partition walls. it can. Thereby, a gap can be made uniform and display quality can be improved.

  Further, according to the present invention, by forming a plurality of substantially regular hexagonal partition walls in a honeycomb shape, the impact resistance is further improved compared to, for example, a case where a plurality of linear partition walls are formed in a stripe shape. be able to. Thereby, the alignment of the ferroelectric liquid crystal that is vulnerable to external impact can be stably maintained.

Further, for example, as shown in FIG. 14, when a sealing agent 31 is applied to the periphery of the first alignment treatment substrate 6 so as to surround the outer periphery of the plurality of substantially regular hexagonal partitions 4, the ferroelectric liquid crystal And the uncured sealant can be prevented from coming into direct contact with each other. As a result, impurities in the uncured sealant and volatile substances generated from the sealant when the sealant is cured can be prevented from being mixed into the ferroelectric liquid crystal. It is possible to avoid deterioration of characteristics.
Hereinafter, each process in the manufacturing method of the liquid crystal display element of this invention is demonstrated.

1. First alignment treatment substrate preparation step In the first alignment treatment substrate preparation step, a plurality of substantially regular hexagonal partition walls are formed on a first substrate, and two sides of the substantially regular hexagonal partition walls are gate lines or source lines. Is formed in a honeycomb shape so that the four sides intersect with the gate line and the source line, and the four sides intersecting with the gate line and the source line are arranged stepwise along the pixel. A partition formation step, and a first alignment film formation step of forming a first alignment film on the first substrate on which the first electrode layer and the substantially regular hexagonal partition are formed, on the first substrate This is a step of preparing a first alignment treatment substrate on which a first electrode layer, a substantially regular hexagonal partition wall and a first alignment film are formed.
Hereinafter, each process in the first alignment treatment substrate preparation process will be described.

(1) Partition formation step In the partition formation step in the present invention, a plurality of substantially regular hexagonal partitions are formed on the first substrate, and two sides of the substantially regular hexagonal partitions are parallel to the gate line or the source line. This is a step of forming a honeycomb shape so that the four sides intersect the gate line and the source line and the four sides intersecting the gate line and the source line are arranged stepwise along the pixel.

  As a method for forming a substantially regular hexagonal partition wall, two sides of the substantially regular hexagonal partition wall are parallel to the gate line or the source line, and four sides intersect the gate line and the source line. The method is not particularly limited as long as it can be formed in a honeycomb shape so that four sides intersecting with each other are arranged stepwise along the pixel. A general patterning method can be applied to the method for forming the substantially regular hexagonal partition wall, which is appropriately selected according to the size of the substantially regular hexagonal partition wall. Specific examples include a photolithography method, an ink jet method, a screen printing method, and the like.

  The partition forming step may be performed before the first alignment film forming step, and a substantially regular hexagonal partition may be formed on the first substrate, or a substantially regular hexagonal partition is formed on the first electrode layer. May be. That is, it may be formed in the order of a substantially regular hexagonal partition and a first electrode layer on the first substrate, or may be formed in the order of a first electrode layer and a substantially regular hexagonal partition.

  Since the other points of the substantially regular hexagonal partition are described in the above section “A. Liquid crystal display element 1. First alignment treatment substrate (1) Substantially regular hexagonal partition”, description here is omitted. To do.

(2) First alignment film forming step The first alignment film forming step in the present invention is a step of forming the first alignment film on the first substrate on which the first electrode layer and the substantially regular hexagonal partition are formed. is there.
In the first alignment film forming step, a single-layer alignment film may be formed, or a reactive liquid crystal layer alignment film is formed, and the reactive liquid crystal is immobilized on the reactive liquid crystal layer alignment film. A reactive liquid crystal layer may be formed. Hereinafter, these two aspects will be described separately.

(I) 1st aspect The 1st alignment film formation process of this aspect is a process of forming a 1st alignment film on the 1st base material in which the 1st electrode layer and the said substantially regular hexagonal partition were formed, This is a step of forming a single-layer alignment film as the first alignment film.

The method for forming the first alignment film is not particularly limited as long as the alignment film capable of aligning the ferroelectric liquid crystal is obtained, and examples thereof include rubbing treatment and photo-alignment treatment. It is done.
In general, a rubbing film can achieve a higher pretilt angle than a photo-alignment film, and thus an alignment film capable of suppressing the occurrence of zigzag defects and hairpin defects can be obtained by rubbing treatment. Can do.
In addition, since the photo-alignment process is a non-contact alignment process, there is no generation of static electricity or dust, and it is useful in that the quantitative alignment process can be controlled.
Hereinafter, the photo-alignment process and the rubbing process will be described.

(A) Photo-alignment treatment When forming a photo-alignment film by photo-alignment treatment, a first alignment film-forming coating solution obtained by diluting a photo-alignment material with an organic solvent is applied on the first electrode layer, Forming a photo-alignment film by drying and irradiating the resulting film with light with controlled polarization, causing photoexcitation reactions (decomposition, isomerization, dimerization) and imparting anisotropy to the film Can do.

  The content of the photodimerization reactive compound or photoisomerization reactive compound in the first alignment film forming coating solution is preferably in the range of 0.05% by mass to 10% by mass, and 0.2% by mass. More preferably, it is in the range of% to 2% by mass. If the content is less than the above range, it will be difficult to impart appropriate anisotropy to the alignment film. Conversely, if the content is more than the above range, the viscosity of the coating liquid will increase, so a uniform coating film will be formed. It is because it becomes difficult to form.

  As a coating method of the first alignment film forming coating solution, for example, spin coating method, roll coating method, rod bar coating method, spray coating method, air knife coating method, slot die coating method, wire bar coating method, ink jet method, A flexographic printing method, a screen printing method, or the like can be used.

  The thickness of the film obtained by applying the first alignment film forming coating solution is preferably in the range of 1 nm to 1000 nm, more preferably in the range of 3 nm to 100 nm. This is because if the thickness of the film is thinner than the above range, sufficient photoalignment may not be obtained, and conversely if the thickness of the film is thicker than the above range, it may be disadvantageous in cost.

  The obtained film can impart anisotropy by causing a photoexcitation reaction by irradiating light with polarization controlled. The wavelength region of the light to be irradiated may be appropriately selected according to the photo-alignment material used, but is preferably in the ultraviolet light range, that is, in the range of 100 nm to 400 nm, more preferably 250 nm to 380 nm. Is within the range. The polarization direction is not particularly limited as long as it can cause the photoexcitation reaction.

  Furthermore, when a polymerizable monomer is used as the photo-alignable material among the above photoisomerization-reactive compounds, it is polymerized by heating after being subjected to a photo-alignment treatment and applied to the alignment film. Anisotropy can be stabilized.

  Since the other points of the photo-alignment film are described in the above section “A. Liquid crystal display element 1. First alignment processing substrate (2) First alignment film”, description thereof is omitted here.

(B) Rubbing treatment When a rubbing film is formed by rubbing treatment, a predetermined material is applied on the first electrode layer, and the obtained film is rubbed with a rubbing cloth in a certain direction to make the film anisotropic. Can be applied to form a rubbing film.

  Examples of the method for applying the material include a roll coating method, a rod bar coating method, a slot die coating method, a wire bar coating method, an ink jet method, a flexographic printing method, and a screen printing method.

  As the rubbing cloth, for example, a cloth made of a fiber such as nylon resin, vinyl resin, rayon, or cotton can be used. For example, by rotating a drum wound with such a rubbing cloth and bringing it into contact with the surface of the film using the above materials, fine grooves are formed in one direction on the film surface, and anisotropy is imparted to the film. Is done.

  Since the other points of the rubbing film are described in the above section “A. Liquid crystal display element 1. First alignment processing substrate (2) First alignment film”, description thereof is omitted here.

(Ii) Second aspect The first alignment film forming step of this aspect is a step of forming the first alignment film on the first base material on which the first electrode layer and the substantially regular hexagonal partition are formed, This is a step of first forming an alignment film for a reactive liquid crystal layer, and then forming a reactive liquid crystal layer formed by fixing the reactive liquid crystal on the alignment film for the reactive liquid crystal layer. That is, a reactive liquid crystal layer alignment film and a reactive liquid crystal layer are stacked as the first alignment film.

  When forming the reactive liquid crystal layer on the alignment layer for the reactive liquid crystal layer, the reactive liquid crystal layer is aligned by the alignment layer for the reactive liquid crystal layer, and the reaction is performed by, for example, irradiating ultraviolet rays to polymerize the reactive liquid crystal The alignment state of the conductive liquid crystal can be fixed. Therefore, the alignment regulating force of the alignment film for the reactive liquid crystal layer can be imparted to the reactive liquid crystal layer, and the reactive liquid crystal layer can act as an alignment film for aligning the ferroelectric liquid crystal. Further, since the reactive liquid crystal is fixed, it has an advantage that it is not affected by temperature or the like. In addition, reactive liquid crystals are relatively similar in structure to ferroelectric liquid crystals, and interact more strongly with ferroelectric liquid crystals, so that ferroelectrics are more effective than using single-layer alignment films. The orientation of the crystalline liquid crystal can be controlled.

  Note that the method for forming the alignment film for the reactive liquid crystal layer is the same as the method for forming the first alignment film described in the first aspect, and thus the description thereof is omitted here.

  The reactive liquid crystal layer is applied to the reactive liquid crystal layer-forming coating liquid containing the reactive liquid crystal, and subjected to an alignment treatment to fix the alignment state of the reactive liquid crystal. Can be formed. Alternatively, the reactive liquid crystal layer may be formed by forming a dry film or the like in advance and laminating the film on the alignment film for the reactive liquid crystal layer. Especially, the method of apply | coating the coating liquid for reactive liquid crystal layer formation is preferable at the point with a simple process.

The coating liquid for forming a reactive liquid crystal layer can be prepared by dissolving or dispersing reactive liquid crystals in a solvent.
The solvent used in the coating liquid for forming the reactive liquid crystal layer is particularly limited as long as it can dissolve or disperse the reactive liquid crystal and the like and does not inhibit the alignment ability of the alignment film for the reactive liquid crystal layer. Is not to be done. Examples of such solvents include 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, Ketones such as methyl isobutyl ketone, cyclohexanone and 2,4-pentanedione; esters such as ethyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and γ-butyrolactone; 2-pyrrolidone, N-methyl-2 Amide solvents such as pyrrolidone, dimethylformamide, dimethylacetamide; t-butyl alcohol, diacetone alcohol, glycerin, monoacetin, ethylene glyco Le, triethylene glycol, or hexylene glycol; phenols, phenol para chlorophenol and the like; methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve such as ethylene glycol monomethyl ether acetate; and the like. These solvents may be used alone or in combination of two or more.

  Further, if only a single type of solvent is used, the solubility of the reactive liquid crystal and the like may be insufficient, or the reactive liquid crystal alignment film may be eroded as described above. In this case, this inconvenience can be avoided by using a mixture of two or more solvents. Among the above-mentioned solvents, hydrocarbons and glycol monoether acetate solvents are preferable as the sole solvent, and mixed solvents of ethers or ketones and glycol solvents are preferable as the mixed solvent. .

  The solid content 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, but usually 0.1 to 40% by mass, Preferably, it adjusts in the range of 1-20 mass%. If the solid content concentration of the reactive liquid crystal layer-forming coating liquid is lower than the above range, the reactive liquid crystal may be difficult to align. Conversely, the solid content concentration of the reactive liquid crystal layer forming coating liquid is within the above range. This is because if it is higher, the viscosity of the reactive liquid crystal layer-forming coating solution becomes high, and it may be difficult to form a uniform coating film.

Furthermore, the following compounds can be added to the reactive liquid crystal layer-forming coating solution as long as the object of the present invention 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 and a 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 object of the present invention. 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.

  Examples of the application method of the coating liquid for forming the reactive liquid crystal layer include spin coating, roll coating, printing, dip coating, die coating, casting, bar coating, blade coating, spray coating, Examples thereof include a gravure coating method, a reverse coating method, an extrusion coating method, an ink jet method, a flexographic printing method, and a screen printing method.

  Moreover, after apply | coating the said coating liquid for reactive liquid crystal layer formation, a solvent is removed. Examples of the method for removing the solvent include removal under reduced pressure or heat removal, and a combination of these.

  After application of the coating liquid for forming the reactive liquid crystal layer, the applied reactive liquid crystal is aligned by the alignment film for the reactive liquid crystal layer so as to have 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 at a temperature lower than the temperature at which the nematic phase transitions to the isotropic phase (NI transition point).

  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. It is done. 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 rays or visible light is used from the viewpoint of the ease of the apparatus. Irradiation light having a wavelength of 150 nm to 500 nm, preferably 250 nm to 450 nm, more preferably 300 nm to 400 nm is used.

  Among them, a method of irradiating ultraviolet rays with active radiation to a polymerizable liquid crystal material in which the photopolymerization initiator generates radicals with ultraviolet rays and the polymerizable liquid crystal material undergoes radical polymerization is preferable. This is because the method using ultraviolet rays as actinic radiation is an already established technique, and therefore it can be easily applied to the present invention 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. As the reactive liquid crystal used in this case, it is preferable that the polymerizable liquid crystal monomer contained in the reactive liquid crystal is thermally polymerized below the NI transition point of the reactive liquid crystal.

  In addition, about the other point of the alignment film for reactive liquid crystal layers, and the reactive liquid crystal layer, since it described in the above-mentioned "A. Liquid crystal display element 1. First alignment processing substrate (2) First alignment film", The description here is omitted.

2. Second alignment treatment substrate preparation step The second alignment treatment substrate preparation step in the present invention is a step of preparing a second alignment treatment substrate in which the second electrode layer and the second alignment film are formed on the second base material.

Usually, the second alignment film forming step includes a second alignment film forming step of forming the second alignment film on the second substrate on which the second electrode layer is formed. Note that the second alignment film formation step is the same as the first alignment film formation step in the first alignment treatment substrate preparation step, and thus the description thereof is omitted here.
Further, since the materials used for the first alignment film and the second alignment film are described in the above section “A. Liquid crystal display element 3. Second alignment processing substrate”, description thereof is omitted here.

3. Liquid crystal dropping step The liquid crystal dropping step in the present invention is a step of dropping a ferroelectric liquid crystal on the first alignment film of the first alignment treatment substrate and in the central portion of the region separated by a substantially regular hexagonal partition. .

  When the ferroelectric liquid crystal is dropped on the first alignment film of the first alignment processing substrate, the ferroelectric liquid crystal may be heated. For example, the temperature of the ferroelectric liquid crystal can be set to a temperature at which the ferroelectric liquid crystal exhibits an isotropic phase or a nematic phase.

  Further, when the ferroelectric liquid crystal is dropped on the first alignment film of the first alignment treatment substrate, the first alignment treatment substrate may be heated. For example, the temperature of the first alignment treatment substrate can be set to a temperature at which the ferroelectric liquid crystal exhibits an isotropic phase or a nematic phase.

  As a method for dropping the ferroelectric liquid crystal, the ferroelectric liquid crystal can be dropped on the first alignment film at the center of the region separated by the substantially regular hexagonal partition wall and can be sealed. The method is not particularly limited as long as it can drop a fixed amount. Examples of the dropping method of the ferroelectric liquid crystal include ejection methods such as an ink jet method and a dispenser method.

  At this time, the droplet amount of the ferroelectric liquid crystal to be dropped is appropriately selected according to the size of the substantially regular hexagonal partition wall, but is approximately 0.01 mg to 0.5 mg per discharge. It is preferable that it is within a range of 0.1 mg to 0.3 mg. If the appropriate amount of liquid is larger than the above range, the flow distance of the ferroelectric liquid crystal becomes long, and the area where the liquid crystal wets and spreads becomes large. Further, if the appropriate amount of liquid is less than the above range, the time required for dropping the ferroelectric liquid crystal becomes very long.

  Further, the position where the ferroelectric liquid crystal is dropped is the central portion of the region on the first alignment film and separated by a substantially regular hexagonal partition. In the present invention, the ferroelectric liquid crystal is allowed to flow to the substantially regular hexagonal partition wall at an approximately equal distance in an arbitrary direction by dropping the ferroelectric liquid crystal at the center of the region separated by the substantially regular hexagonal partition wall. It is possible to make it difficult to cause disorder in the alignment of the ferroelectric liquid crystal near the substantially regular hexagonal partition wall.

  It is preferable that the ferroelectric liquid crystal is dropped at one location in the center of the region separated by the substantially regular hexagonal partition. This is because when the ferroelectric liquid crystal is dropped at a plurality of locations, the distance from the position where the ferroelectric liquid crystal is dropped to the six sides of the substantially regular hexagonal partition wall is different. Further, when the ferroelectric liquid crystal is dropped at a plurality of locations, when the dropped ferroelectric liquid crystal flows, alignment disorder may occur at the interface where the flowing ferroelectric liquid crystals contact each other.

  Since the ferroelectric liquid crystal is described in the above section “A. Liquid crystal display element 2. Ferroelectric liquid crystal”, description thereof is omitted here.

4). Substrate Bonding Step The substrate bonding step in the present invention is a step of bonding the first alignment processing substrate and the second alignment processing substrate on which the ferroelectric liquid crystal is dropped.

  Before the first alignment treatment substrate and the second alignment treatment substrate are bonded together, a sealant is applied to the peripheral portion of at least one of the first alignment treatment substrate and the second alignment treatment substrate. As illustrated in FIG. 14, the sealing agent 31 is usually applied in a frame shape so as to surround the outer periphery of the plurality of substantially regular hexagonal partition walls 4.

  Moreover, when apply | coating a sealing agent to a 1st orientation processing board | substrate, a sealing agent may be apply | coated on a 1st base material, and you may apply | coat on a 1st alignment film. When the sealing agent is applied on the first base material, the adhesion between the first alignment treatment substrate and the second alignment treatment substrate can be enhanced. When applying the sealing agent on the first substrate, the first alignment film is formed in a pattern so that the first alignment film is not formed on the peripheral portion of the first substrate. On the other hand, also when apply | coating a sealing agent to a 2nd orientation processing board | substrate, a sealing agent may be apply | coated on a 2nd base material and you may apply | coat on a 2nd alignment film.

  The sealing agent may be applied to the first alignment treatment substrate on which the substantially regular hexagonal partition walls are formed in relation to the substantially regular hexagonal partition walls, and the second alignment treatment substrate on which the substantially regular hexagonal partition walls are not formed. Or may be applied to both substrates. In addition, the sealing agent may be applied to the first alignment treatment substrate on which the ferroelectric liquid crystal is dropped in relation to the ferroelectric liquid crystal, or on the second alignment treatment substrate on which the ferroelectric liquid crystal is not dropped. You may apply | coat and may apply | coat to both board | substrates. In any case, the sealing agent is applied so that the outer periphery of the substantially regular hexagonal partition wall is surrounded when the first alignment treatment substrate and the second alignment treatment substrate are overlapped.

  Further, when the sealing agent is applied to the first alignment processing substrate, the sealing agent may be applied before dropping the ferroelectric liquid crystal onto the first alignment processing substrate, and the ferroelectric liquid crystal is applied to the first alignment processing substrate. You may apply | coat a sealing compound after dripping.

  As the sealing agent, sealing agents generally used for liquid crystal display elements can be used, and examples thereof include thermosetting resins and ultraviolet curable resins.

  The method for applying the sealing agent is not particularly limited as long as it can apply the sealing agent at a predetermined position, and examples thereof include a dispenser method and a screen printing method.

  Thus, after apply | coating a sealing compound, a 1st orientation processing board | substrate and a 2nd orientation processing board | substrate are piled up. When the first alignment treatment substrate and the second alignment treatment substrate are overlapped, the first alignment treatment substrate and the second alignment treatment substrate are arranged so that the alignment treatment direction of the first alignment film and the alignment treatment direction of the second alignment film are substantially parallel to each other. The two-oriented substrate is opposed.

  Further, when the first alignment treatment substrate and the second alignment treatment substrate are overlapped, the first alignment treatment substrate and the second alignment treatment substrate are heated. The temperature of the first alignment treatment substrate and the second alignment treatment substrate is preferably set to a temperature at which the ferroelectric liquid crystal exhibits an isotropic phase or a nematic phase, and among them, the temperature at which the ferroelectric liquid crystal exhibits an isotropic phase. It is preferable to set to. The specific temperature varies depending on the type of ferroelectric liquid crystal and is appropriately selected. In addition, the upper limit of the temperature of the first alignment treatment substrate and the second alignment treatment substrate is set to a temperature at which the ferroelectric liquid crystal does not deteriorate. Usually, the temperature of the first alignment treatment substrate and the second alignment treatment substrate is set in the vicinity of the nematic phase-isotropic phase transition temperature, or 5 ° C. to 10 ° C. higher than the nematic phase-isotropic phase transition temperature. Set to

Furthermore, when the first alignment treatment substrate and the second alignment treatment substrate are overlapped, it is preferable that the chamber is evacuated to sufficiently reduce the pressure between the first alignment treatment substrate and the second alignment treatment substrate. Thereby, it can prevent that a space | gap remains in a liquid crystal cell.
After making the first alignment treatment substrate and the second alignment treatment substrate face each other in this way, the first alignment treatment substrate and the second alignment treatment substrate are superposed under reduced pressure, and a constant pressure is applied so that the cell gap becomes uniform. Add And a pressure is further added between a 1st orientation processing board | substrate and a 2nd orientation processing board | substrate by returning the inside of a chamber to a normal pressure. Thereby, a cell gap can be made more uniform. In this way, the first alignment treatment substrate and the second alignment treatment substrate are pressure-bonded via the sealant.

After superposing the first alignment treatment substrate and the second alignment treatment substrate, the sealant is cured and the first alignment treatment substrate and the second alignment treatment substrate are bonded together.
The curing method of the sealing agent varies depending on the type of the sealing agent used, and examples thereof include a method of irradiating with ultraviolet rays and a method of heating. At this time, normally, the sealing agent is cured while maintaining the pressure when the first alignment treatment substrate and the second alignment treatment substrate are overlapped.

After the first alignment treatment substrate and the second alignment treatment substrate are bonded together, the ferroelectric liquid crystal sealed between the first alignment treatment substrate and the second alignment treatment substrate is aligned. Specifically, the ferroelectric liquid crystal is in a chiral smectic C (SmC ^* ) phase state. As described above, the first alignment processing substrate and the second alignment processing substrate are heated to a predetermined temperature, and thereby the ferroelectric liquid crystal is heated to be in a nematic phase or isotropic phase, for example. The ferroelectric liquid crystal can be cooled to be in the SmC ^* phase state.

  When cooling the heated ferroelectric liquid crystal, the ferroelectric liquid crystal is usually gradually cooled to room temperature.

  When a polymerizable monomer is added to the ferroelectric liquid crystal, the polymerizable monomer is polymerized after aligning the ferroelectric liquid crystal. The polymerization method of the polymerizable monomer is appropriately selected according to the type of the polymerizable monomer. For example, when an ultraviolet curable resin monomer is used as the polymerizable monomer, the polymerizable monomer can be polymerized by ultraviolet irradiation. .

  Further, when polymerizing the polymerizable monomer, a voltage may or may not be applied to the liquid crystal layer composed of the ferroelectric liquid crystal, but no voltage is applied to the liquid crystal layer. It is preferable to polymerize a polymerizable monomer.

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

The following examples illustrate the present invention in more detail.
[Example 1]
(Fabrication of TFT substrate for ferroelectric liquid crystal)
The glass substrate on which the TFT electrode was formed was washed thoroughly, a transparent resist (trade name: manufactured by NN780 JSR) was spin coated on the glass substrate, dried under reduced pressure, and prebaked at 90 ° C. for 3 minutes. Subsequently, it exposed to a mask with 100 mJ / cm ² ultraviolet rays, developed with an inorganic alkali solution, and post-baked at 230 ° C. for 30 minutes. As a result, as shown in FIG. 15, on the non-pixel region of the TFT electrode, the distance between two sides parallel to the gate line or the source line is 15 mm, and the height is 1.5 μm. Formed.
Next, a 2% by mass cyclopentanone solution of a photodimerization reaction type photo-alignment film material (trade name: ROP-102, manufactured by Rorlic Technology) is spin-coated so as to cover the substantially regular hexagonal partition wall, and 130 After drying at 10 ° C. for 10 minutes, alignment treatment was performed by irradiating with linearly polarized ultraviolet rays at about 100 mJ / cm ² .

(Preparation of counter substrate)
The glass substrate on which the ITO electrode is formed is thoroughly washed, and a 2% by mass cyclopentanone solution of a photodimerization reaction type photo-alignment film material (trade name: ROP-103, manufactured by Lorrick Technology) is applied on the glass substrate. After spin-coating and drying at 130 ° C. for 10 minutes, alignment treatment was performed by irradiating with linear ultraviolet polarized light of about 100 mJ / cm ² . Thereafter, a 5 mass% cyclopentanone solution of polymerizable liquid crystal (trade name: ROF-5101) was spin-coated on the photo-alignment film, dried at 55 ° C. for 5 minutes, and then irradiated with about 1000 mJ / cm ^{2 of} non-polarized light. .

(Production of liquid crystal display element)
Next, the prepared TFT substrate for ferroelectric liquid crystal was arranged, and ferroelectric liquid crystal (trade name: R2301, manufactured by AZ Electronic Materials) was applied at room temperature using a pneumatic dispenser. At this time, the liquid crystal was applied so as to come to the center of the region separated by the substantially regular hexagonal partition wall, the application shape was a dot shape, and the weight of the liquid crystal at one point was 0.1 mg. Thereafter, the TFT substrate for ferroelectric liquid crystal was placed on a hot plate (heated at 100 ° C.) placed in a vacuum chamber.
Next, the produced counter substrate was adsorbed by an adsorption plate, and the ferroelectric liquid crystal TFT substrate and the counter substrate were opposed to each other so that the respective alignment treatment directions were parallel. Then, the substrates were brought into close contact with each other in a state where evacuation was performed so that the inside of the vacuum chamber became 10 Torr, and after applying a certain pressure, the inside of the vacuum chamber was returned to normal pressure. Thereafter, the ferroelectric liquid crystal was gradually cooled to room temperature to produce a liquid crystal display element.

(Evaluation)
When the alignment state of the ferroelectric liquid crystal was observed with a polarizing microscope with respect to the produced liquid crystal display element, there was no alignment defect due to the flow disorder of the liquid crystal in the vicinity of the substantially regular hexagonal partition wall, and uniform monodomain alignment was observed throughout the display area. Obtained.

[Comparative Example 1]
A liquid crystal display device was produced in the same manner as in Example 1 except that the substantially regular hexagonal partition walls were changed to columnar spacers and 10 μm □ columnar spacers were evenly arranged at intervals of 300 μm.
In the produced liquid crystal display element, there was no extinction position and no orientation at the boundary portion where the applied droplets collided with each other.

[Comparative Example 2]
A liquid crystal display element was produced in the same manner as in Example 1 except that the substantially regular hexagonal partition was formed by changing to a square partition having a side of 15 mm.
In the produced liquid crystal display element, the alignment failure was particularly remarkable at the corners of the square, and there was no extinction position and no alignment was achieved.

[Example 2]
A liquid crystal display device was produced in the same manner as in Example 1 except that the substantially regular hexagonal partition was formed so that the distance between two sides parallel to the gate line or source line was 10 mm.
(Evaluation)
When the alignment state of the ferroelectric liquid crystal was observed with a polarizing microscope with respect to the produced liquid crystal display element, there was no alignment defect due to the flow disorder of the liquid crystal in the vicinity of the substantially regular hexagonal partition wall, and uniform monodomain alignment was observed throughout the display area. Obtained.

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display element 2 ... 1st base material 3 ... 1st electrode layer 4 ... Substantially hexagonal partition 5 ... 1st alignment film 6 ... 1st alignment processing board | substrate 10 ... Liquid crystal layer 12 ... 2nd base material 13 ... 1st Two electrode layers 15 ... second alignment film 16 ... second alignment processing substrate 20 ... pixel 23x ... gate line 23y ... source line 24 ... region separated by substantially regular hexagonal partition walls 25 ... separated by substantially regular hexagonal partition walls Central portion of region 26 ... Ferroelectric liquid crystal s1, s2, s3, s4, s5, s6 ... Side of substantially regular hexagonal partition

Claims (9)

A first base material; a first electrode layer and a plurality of substantially regular hexagonal partitions formed on the first substrate; and a first orientation formed on the first electrode layer and the substantially regular hexagonal partitions. A first alignment treatment substrate having a film, a second substrate, a second electrode layer formed on the second substrate, and a second alignment film formed on the second electrode layer. A second alignment processing substrate is disposed so that the first alignment film and the second alignment film face each other, and a ferroelectric liquid crystal is sandwiched between the first alignment film and the second alignment film. A liquid crystal display element comprising:
The substantially regular hexagonal partition wall has two sides parallel to the gate line or the source line, and four sides intersecting the gate line and the source line, and the four sides intersecting the gate line and the source line extend along the pixel. A liquid crystal display element, wherein the plurality of substantially regular hexagonal partitions are arranged in a honeycomb shape.   The liquid crystal display element according to claim 1, wherein a distance between two sides of the substantially regular hexagonal partition wall parallel to the gate line or the source line is in a range of 3 mm to 15 mm.   The liquid crystal display element according to claim 1, wherein the constituent materials of the first alignment film and the second alignment film have different compositions with the ferroelectric liquid crystal interposed therebetween.   4. The liquid crystal display element according to claim 1, wherein the ferroelectric liquid crystal exhibits monostability.   The liquid crystal display element according to claim 4, wherein the ferroelectric liquid crystal exhibits a half V-shaped switching characteristic. On the first base material, a plurality of substantially regular hexagonal partitions are arranged such that two sides of the substantially regular hexagonal partitions are parallel to the gate line or source line, and four sides intersect the gate line and source line. In addition, a partition forming step for forming a honeycomb shape so that four sides intersecting the gate line and the source line are arranged stepwise along the pixel, and a first electrode layer and the substantially regular hexagonal partition are formed. A first alignment film forming step of forming a first alignment film on the first substrate, and a first electrode layer, a substantially regular hexagonal partition wall, and a first alignment film are formed on the first substrate. A first alignment treatment substrate preparation step of preparing a first alignment treatment substrate;
A second alignment treatment substrate preparation step of preparing a second alignment treatment substrate in which the second electrode layer and the second alignment film are formed on the second substrate;
A liquid crystal dropping step of dropping a ferroelectric liquid crystal on a first alignment film of the first alignment processing substrate and in a central portion of a region separated by the substantially regular hexagonal partition;
A method of manufacturing a liquid crystal display element, comprising: a substrate bonding step of bonding the first alignment processing substrate on which the ferroelectric liquid crystal is dropped and the second alignment processing substrate.   7. The method of manufacturing a liquid crystal display element according to claim 6, wherein a distance between two sides parallel to the gate line or the source line of the substantially regular hexagonal partition wall is in a range of 3 mm to 15 mm.   8. The method of manufacturing a liquid crystal display element according to claim 6, wherein materials having different compositions are used for the first alignment film and the second alignment film with the ferroelectric liquid crystal interposed therebetween.   9. The method for manufacturing a liquid crystal display element according to claim 6, wherein a material exhibiting monostability is used as the ferroelectric liquid crystal.

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