JP2008026387A - Method for manufacturing substrate for liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a substrate for a liquid crystal display element, which does not require highly precise alignment. <P>SOLUTION: The purpose is achieved by providing the method for manufacturing the substrate for the liquid crystal display element, which is characterized by including: a photosensitive resin layer forming step to form the photosensitive resin layer composed of a positive photosensitive resin on a base material with an electrode layer and a pattern shaped light shielding part formed thereon; a first exposing step to expose the photosensitive resin layer from the base material side; a second exposing step to expose the photosensitive resin layer subsequent to the first exposing step via a photomask from the photosensitive resin layer side; and a developing step to develop the photosensitive resin layer subsequent to the second exposing step and to form a partition wall composed of the positive photosensitive resin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a substrate for a liquid crystal display element that has partition walls and is suitably used for a liquid crystal display element using a ferroelectric liquid crystal.

  Liquid crystal display elements have been widely used from large displays to portable information terminals because of their thinness and low power consumption, and their development is actively underway.

  In a conventional liquid crystal display element, glass beads or resin beads are dispersed between a pair of substrates to control an inter-substrate spacing (cell gap) for sandwiching liquid crystals. However, in the dispersion of beads or the like, it is difficult to strictly control the cell gap and to suppress deformation against external pressure. Thus, columnar or wall-like spacers are formed between substrates using a photolithography method or the like (see, for example, Patent Document 1).

However, this wall-shaped spacer (partition wall) is provided to ensure the strength to keep the cell gap constant, and has a height similar to that of the cell gap, so it is extremely thin. I can't.
The wall-like spacer is preferably arranged in the non-display area from the viewpoint of the aperture ratio. For example, Patent Document 2 discloses an electrode plate for a liquid crystal display device in which stripe-shaped partition walls are formed corresponding to stripe-shaped light shielding portions. On the other hand, in recent years, display of personal computers and displays used for portable information terminals have been improved in definition, and the width of the non-display area tends to be narrowed. For this reason, in order to arrange the partition walls in the non-display area, highly accurate alignment is required.

In recent years, ferroelectric liquid crystal (FLC) has been attracting attention because it is a liquid crystal suitable for high-speed devices with a response speed as short as μs. As the ferroelectric liquid crystal, a liquid crystal material that changes phase with the cholesteric (Ch) phase-chiral smectic C (SmC ^* ) phase in the temperature lowering process and does not pass through the smectic A (SmA) phase (upper stage in FIG. 7), or in the temperature lowering process. There is a liquid crystal material (lower stage in FIG. 7) that changes in phase with a cholesteric (Ch) phase-smectic A (SmA) phase-chiral smectic C (SmC ^* ) phase and exhibits the SmC ^* phase via the SmA phase.

  Ferroelectric liquid crystals are difficult to align because they have higher molecular ordering than nematic liquid crystals. In particular, in a ferroelectric liquid crystal that does not pass through the SmA phase, two regions having different layer normal directions (hereinafter referred to as “double domain”) are generated (the upper part of FIG. 7). Such a double domain becomes a serious problem because black-and-white inversion is displayed during driving. On the other hand, the ferroelectric liquid crystal passing through the SmA phase has a chevron structure in which the distance between the smectic layers is reduced in the process of phase change and the smectic layer is bent to compensate for the volume change. As a result, domains having different major axis directions of liquid crystal molecules are formed, and alignment defects called zigzag defects and hairpin defects are likely to occur at the boundary surfaces. Such a defect causes a decrease in contrast due to light leakage.

As a method for improving the zigzag defect and the hairpin defect, a method is disclosed in which a plurality of linear partition walls are formed substantially parallel to the uniaxial alignment treatment direction of the alignment film to provide a linear space (for example, Patent Documents). 3). By confining the ferroelectric liquid crystal in this linear space, the flow of liquid crystal molecules is induced substantially parallel to the longitudinal direction of the linear partition. As a result, the orientation of the ferroelectric liquid crystal is improved, and an SmC ^* phase having no alignment defect is formed.

  As a method for improving the double domain, a method is disclosed in which a plurality of partition walls are formed between substrates so that the molecular direction in the monostable state of the ferroelectric liquid crystal and the extending direction of the partition walls are substantially the same. (For example, see Patent Document 4).

According to the method of providing these partition walls, not only orientation control but also impact resistance can be improved. Since the SmC ^* phase is very vulnerable to external impact, the high impact resistance is useful in a liquid crystal display element using a ferroelectric liquid crystal.

JP 10-161125 A JP-A-11-212098 JP 2000-111184 A JP 2006-39519 A

  Therefore, a method capable of forming a partition without requiring high-precision alignment is desired. As a method of forming a spacer that does not require high-precision alignment, self-alignment is conceivable. For example, when a spacer is formed by backside exposure using a thin film transistor (TFT) substrate, the periphery of each pixel electrode is surrounded. Spacers remain in a matrix. For this reason, after the TFT substrate and the counter substrate are bonded together, liquid crystal cannot be injected between the two substrates. In recent years, a liquid crystal sealing method in which liquid crystal is dropped onto one of a pair of substrates and then both substrates are bonded together in a vacuum has been put into practical use. It is very difficult to drop the liquid crystal accurately in such a region.

  The present invention has been made in view of the above problems, and has as its main object to provide a method for manufacturing a substrate for a liquid crystal display element that does not require highly accurate alignment.

  In order to achieve the above object, the present invention provides a base material, an electrode layer formed on the base material, a light shielding part formed in a pattern on the base material, and the light shielding part on the light shielding part. A method for manufacturing a substrate for a liquid crystal display element having a partition made of a positive photosensitive resin, wherein the substrate is formed with a pattern different from the pattern of the part, and the substrate on which the electrode layer and the light shielding part of the pattern are formed A photosensitive resin layer forming step of forming a photosensitive resin layer made of the positive photosensitive resin on the material; a first exposure step of exposing the photosensitive resin layer from the substrate side; and the first After the exposure process, the photosensitive resin layer is exposed through a photomask from the photosensitive resin layer side, and the photosensitive resin layer after the second exposure process is developed to develop the partition wall. A liquid crystal display element comprising: a developing step for forming the liquid crystal display element To provide a manufacturing method of use substrate.

  According to the present invention, first, the photosensitive resin layer is left on the light shielding portion by self-alignment by exposing the patterned light shielding portion on the base material as a mask in the first exposure step. By exposing through a photomask in a two-exposure process, the photosensitive resin layer can remain at a desired position on the light shielding portion. In the second exposure step, it is only necessary to use a photomask in which the region where the partition wall is formed is shielded from the unexposed regions in the first exposure step, so that there is an advantage that neither a precise mask pattern nor high-precision alignment is required. Have.

  In the said invention, it is preferable that the said board | substrate for liquid crystal display elements is used for the liquid crystal display element using a ferroelectric liquid crystal. As described in the background section, ferroelectric liquid crystals are likely to cause alignment defects. However, when the liquid crystal display element substrate obtained by the present invention is used for a liquid crystal display element using ferroelectric liquid crystals. This is because the formation of the partition walls can suppress the occurrence of alignment defects.

  In the present invention, the electrode layer is preferably a pixel electrode, and the light shielding portion is preferably a gate electrode, a source electrode, a drain electrode, and a thin film transistor (TFT). In general, since the arrangement of the gate electrode, the source electrode, the drain electrode, and the TFT is complicated, a precise mask pattern and high-precision alignment are required when forming the partition wall. In addition, since high-precision alignment is not required, it is useful for manufacturing a liquid crystal display element substrate having TFTs.

  In the present invention, the partition wall is formed through the first exposure step of exposing using the patterned light-shielding portion as a mask and the second exposure step of exposing through the photomask, so that high-precision alignment is not required. There exists an effect that a partition can be formed.

Hereinafter, the manufacturing method of the substrate for a liquid crystal display element of the present invention will be described in detail.
The method for producing a substrate for a liquid crystal display element of the present invention includes a base material, an electrode layer formed on the base material, a light shielding portion formed in a pattern on the base material, and the above-described light shielding portion on the light shielding portion. A method for manufacturing a substrate for a liquid crystal display element having a partition formed of a positive photosensitive resin and having a pattern different from a pattern of a light shielding part, wherein the electrode layer and the light shielding part in a pattern are formed A photosensitive resin layer forming step of forming a photosensitive resin layer made of the positive photosensitive resin on the substrate; a first exposure step of exposing the photosensitive resin layer from the substrate side; After the one exposure step, the photosensitive resin layer is exposed to the photosensitive resin layer from the photosensitive resin layer side through a photomask, and the photosensitive resin layer after the second exposure step is developed to develop the partition wall. And a developing step for forming That.

A method for producing a substrate for a liquid crystal display element of the present invention will be described with reference to the drawings.
1 and 2 are process diagrams showing an example of a method for producing a substrate for a liquid crystal display element of the present invention. FIG. 2 (a) is a cross-sectional view taken along line AA in FIG. 1 (a), and FIG. ) Is a cross-sectional view taken along line BB in FIG. 1B, and FIG. 2D is a cross-sectional view taken along line CC in FIG.
First, the pixel electrode 2 is formed on the substrate 1, and the gate electrode 3a, the source electrode 3b, the drain electrode 3c, and the thin film transistor (TFT) 4 are formed (FIGS. 1A and 2A). Here, the pixel electrode 2 is formed as the electrode layer, and the gate electrode 3a, the source electrode 3b, the drain electrode 3c, and the TFT 4 are formed as the light shielding portion.
Next, a positive photosensitive resin composition is applied on the substrate 1 on which the pixel electrodes 2 and the like are formed to form a photosensitive resin layer 6, and the light-shielding portion is applied to the photosensitive resin layer 6. Using a certain gate electrode 3a, source electrode 3b, drain electrode 3c and TFT 4 as a mask, exposure is performed from the substrate 1 side (FIGS. 1B and 2B, photosensitive resin layer forming step and first exposure step). . At this time, the region where the gate electrode 3a, the source electrode 3b, the drain electrode 3c, and the TFT 4 which are light shielding portions are provided becomes the unexposed region 16a, and the other region becomes the exposed region 16b.
Next, it exposes from the photosensitive resin layer 6 side through the photomask 11 with respect to the photosensitive resin layer 6 after the said 1st exposure process (FIG.2 (c), 2nd exposure process). At this time, the photomask 11 designed so as to shield the region where the partition wall is formed from the unexposed region 16a in the first exposure step is used.
Next, by developing the photosensitive resin layer after the second exposure step, partition walls 6 'are formed (FIGS. 1C and 2D, development step). Of the photosensitive resin layer, only a portion which is an unexposed area in the first exposure process and is also an unexposed area in the second exposure process remains after development. Here, one line of barrier ribs 6 'is formed for every three lines of the source electrode 3b.

  According to the present invention, in the first exposure step, the photosensitive resin layer can be left on the light shielding portion by self-alignment by exposing the patterned light shielding portion on the base material as a mask. In the second exposure step, the photosensitive resin layer can be left at a desired position on the light-shielding portion by performing exposure through a photomask. In this second exposure step, if a photomask designed so that the region where the partition walls are formed is shielded from the region where the photosensitive resin layer is left in the first exposure step in advance (unexposed region) is used. Therefore, high accuracy is not required for the dimensional accuracy of the mask pattern of the photomask. Similarly, in the second exposure step, it is only necessary to prevent the region where the partition walls are formed from being exposed in the region where the photosensitive resin layer is left in the first exposure step in advance (unexposed region). However, high accuracy is not required. That is, the partition wall can be formed with simple alignment or without alignment.

  In particular, when a plastic substrate is used as the base material, the method for producing a substrate for a liquid crystal display element of the present invention is suitable. In general, alignment is important because the dimensions of a plastic substrate are easily changed by heat and moisture. On the other hand, in the present invention, since the partition walls can be formed with simple alignment or without alignment as described above, a plastic substrate having a large dimensional change can also be used.

  Further, as described above, in the first exposure step, the pattern-shaped light shielding portion on the substrate is exposed as a mask, so that the partition wall is necessarily disposed on the light shielding portion. In general, in a liquid crystal display element having a partition wall, a liquid crystal alignment defect is likely to occur near the partition wall. On the other hand, in the present invention, since the partition walls are arranged on the light shielding portion, it is possible to reduce the influence on the image display due to the alignment failure in the vicinity of the partition walls.

Furthermore, according to the present invention, since the photosensitive resin layer left in the first exposure step is thinned out in the second exposure step, it can be avoided that the barriers prevent the liquid crystal from being sealed.
For example, when the partition walls are formed in a stripe shape as illustrated in FIGS. 1 and 2, the stripe-shaped partition walls are formed by thinning out the photosensitive resin remaining in the matrix shape. When a liquid crystal display element is manufactured using the liquid crystal display element substrate thus obtained, when a liquid crystal is injected between both substrates after the liquid crystal display element substrate and the counter substrate are bonded together, a stripe is used. Since both ends of the region separated by the partition walls are open, liquid crystal can be injected from that portion.
In addition, for example, when forming a larger matrix-like partition wall by thinning out the photosensitive resin layer that remains in a matrix shape (not shown), when producing a liquid crystal display element using the obtained liquid crystal display element substrate, When the liquid crystal display element substrate and the counter substrate are bonded together after the liquid crystal is dropped onto the area separated by the partition of the liquid crystal display element substrate, each area where the liquid crystal is dropped can be set to a desired size. It is.

3 and 4 are process diagrams showing another example of a method for manufacturing a substrate for a liquid crystal display element according to the present invention. FIG. 4 (a) is a sectional view taken along the line DD in FIG. 3 (a). (B) is the EE sectional view taken on the line of FIG.3 (b), FIG.4 (d) is the FF sectional view taken on the line of FIG.3 (c).
First, the black matrix 22 and the colored layer 23 are formed on the base material 21, and the common electrode 24 is further formed (FIGS. 3A and 4A). Here, the common electrode 24 is formed as an electrode layer, and the black matrix 22 is formed as a light shielding portion.
Next, a positive photosensitive resin composition is applied on the base material 1 on which the common electrode 24 and the like are formed to form a photosensitive resin layer 26. The photosensitive resin layer 26 is covered with a light shielding portion. Using the black matrix 22 as a mask, exposure is performed from the substrate 21 side (FIGS. 3B and 4B, photosensitive resin layer forming step and first exposure step). At this time, the area where the black matrix 22 as the light shielding portion is provided becomes the unexposed area 36a, and the other area becomes the exposed area 36b. Thereby, the photosensitive resin layer can remain on the light shielding portion (black matrix 22).
Next, the photosensitive resin layer 26 after the first exposure step is exposed from the photosensitive resin layer 26 side through the photomask 31 (FIG. 4C, second exposure step). At this time, the photomask 31 designed so as to shield the region where the partition wall is to be formed from the unexposed region 36a in the first exposure step is used. Thereby, the photosensitive resin layer can remain at a desired position on the light shielding portion (black matrix 22).
Next, the partition 26 'is formed by developing the photosensitive resin layer after the second exposure step (FIGS. 3C and 4D, development step). Of the photosensitive resin layer, only a portion which is an unexposed area in the first exposure process and is also an unexposed area in the second exposure process remains after development.
In FIG. 3, the common electrode is omitted.

  As described above, in the present invention, the photosensitive resin layer is formed on the base material using the base material on which the light shielding portion is formed in a pattern, and the exposure from the base material side and the photosensitive resin layer side By performing exposure twice, it is possible to form a partition wall at a desired position on the patterned light-shielding portion with simple alignment.

The method for producing a substrate for a liquid crystal display element of the present invention includes a light shielding part forming step of forming a light shielding part in a pattern on a base material, an electrode layer forming step of forming an electrode layer on the base material, and the photosensitivity described above. You may have the resin layer formation process, the 1st exposure process, the 2nd exposure process, and the partition formation process which has a image development process. Moreover, the manufacturing method of the board | substrate for liquid crystal display elements of this invention may have the alignment film formation process which forms an alignment film on the base material in which the electrode layer and the pattern-shaped light-shielding part were formed.
Hereinafter, each process in the manufacturing method of the board | substrate for liquid crystal display elements of this invention is demonstrated.

1. Partition formation step The partition formation step in the present invention includes a photosensitive resin layer formation step of forming a photosensitive resin layer made of a positive photosensitive resin on a substrate on which an electrode layer and a patterned light-shielding portion are formed. A first exposure step of exposing the photosensitive resin layer from the substrate side; a second exposure step of exposing the photosensitive resin layer from the photosensitive resin layer side through a photomask after the first exposure step; And developing a photosensitive resin layer after the second exposure step to form a partition.
Hereinafter, each process in a partition formation process is demonstrated.

(1) Photosensitive resin layer formation process The photosensitive resin layer formation process in this invention forms the photosensitive resin layer which consists of positive photosensitive resin on the base material in which the electrode layer and the pattern-shaped light-shielding part were formed. It is a process to do.

  The positive photosensitive resin used in the present invention is not particularly limited, and those generally used can be used. For example, a chemically amplified photosensitive resin based on a novolac resin, a cyclic rubber system such as 1,4-cis-polyisoprene, a polyvinyl cinnamate system such as one synthesized from polyvinyl alcohol and cinnamate chloride, Examples thereof include quinonediazide compounds such as naphthoquinonediazide compounds.

In this step, a photosensitive resin layer can be formed by applying a positive photosensitive resin composition containing the positive photosensitive resin.
Examples of the application method of the positive photosensitive resin composition include spin coating, casting, dipping, bar coating, blade coating, roll coating, gravure coating, flexographic printing, and spray coating. Can be mentioned.
Under the present circumstances, the thickness of the photosensitive resin layer after application | coating is suitably adjusted according to the thickness of the target partition.

  After the application of the positive photosensitive resin composition, the photosensitive resin layer may be subjected to a heat treatment (pre-baking).

(2) First exposure step The first exposure step in the present invention is a step of exposing the photosensitive resin layer from the substrate side.

  The exposure method is not particularly limited as long as it is a method of exposing the photosensitive resin layer from the substrate side. In the present invention, since the patterned light-shielding portion on the substrate can be used as a mask, exposure can be performed by self-alignment.

(3) Second exposure step The second exposure step in the present invention is a step of exposing the photosensitive resin layer from the photosensitive resin layer side through a photomask after the first exposure step.

  The exposure method is not particularly limited as long as it is a method of exposing the photosensitive resin layer from the photosensitive resin layer side through a photomask. For example, proximity exposure can be performed in which a photomask is arranged and exposed with a gap of about several tens of μm from the surface of the photosensitive resin layer.

  In addition, as described above, the photomask used in this step may be any photomask designed so that the region where the partition wall is formed is shielded from the unexposed regions in the first exposure step. This photomask does not require a precise mask pattern.

(4) Development step The development step in the present invention is a step of developing the photosensitive resin layer after the second exposure step to form a partition.

In this step, the photosensitive resin layer is partially removed by development. Of the photosensitive resin layer, the portion decomposed by the exposure in the first exposure step and the portion decomposed by the exposure in the second exposure step are selectively removed, and other portions remain. That is, in the photosensitive resin layer, the exposure region in the first exposure step and the exposure region in the second exposure step are selectively removed, and the unexposed region in the first exposure step and the second exposure step. An unexposed area remains.
The developing method is not particularly limited, and a general method can be used.

  Moreover, you may heat-process (post-bake) with respect to the formed partition after image development. This heat treatment can be appropriately set, for example, at a temperature of 100 to 250 ° C. and a treatment time of about 10 to 60 minutes.

(5) Partition Wall In the present invention, the partition wall is formed in a pattern on the light shielding portion. The pattern shape of the partition wall varies depending on the pattern shape of the light shielding portion. For example, a stripe shape, a matrix shape, and the like can be given.

  In the present invention, as will be described later, when a gate electrode, a source electrode, a drain electrode, a TFT, and the like are formed as the light shielding portion, the partition wall is formed at least of the gate electrode, the source electrode, the drain electrode, and the TFT. It only needs to correspond to either one. For example, the barrier ribs may be formed in a stripe shape corresponding to the source electrode 3b, the drain electrode 3c, and the TFT 4 as illustrated in FIG. 1C. Although not illustrated, the barrier rib corresponds to the gate electrode and the TFT. It may be formed in a stripe shape, or may be formed in a matrix shape corresponding to the gate electrode, the source electrode, the drain electrode, and the TFT.

  A plurality of partition walls are formed, and it is preferable that the plurality of partition walls be regularly formed at predetermined positions, and it is particularly preferable that the partition walls are formed substantially at equal intervals. For example, the partition walls can be formed at a pitch of 1 pixel or 3 pixels. When a liquid crystal display element is produced using the liquid crystal display element substrate obtained by the present invention, for example, when liquid crystal is dropped on a region separated by the partition on the liquid crystal display element substrate, a plurality of partition wall formation positions This is because it is difficult to accurately control the dropping amount of the liquid crystal when the liquid crystal is disordered.

The pitch of the partition walls varies depending on the pitch of the light shielding portions, but can be about 50 μm to 3 mm, preferably in the range of 300 μm to 2.5 mm, and more preferably in the range of 1 mm to 2 mm. If the pitch of the partition walls is smaller than the above range, when the liquid crystal display element substrate obtained by the present invention is used for a liquid crystal display element, the display quality may be deteriorated due to liquid crystal alignment failure in the vicinity of the partition walls. is there. If the partition pitch is larger than the above range, it may vary depending on the size of the liquid crystal display element, but the desired impact resistance may not be obtained, or it may be difficult to keep the thickness of the liquid crystal layer constant. Because there is.
In addition, the pitch of a partition means the distance from the center part of an adjacent partition to a center part.

  Further, the width of the partition wall varies depending on the width of the light shielding part, but can be about 2 μm to 30 μm, preferably within the range of 3 μm to 20 μm, more preferably within the range of 5 μm to 15 μm. .

  Furthermore, the thickness of the partition wall is usually set to be approximately the same as the thickness of the liquid crystal layer in the liquid crystal display element in which the liquid crystal display element substrate obtained by the present invention is used.

  Note that the pitch, width, and thickness of the partition walls can be observed by using a scanning electron microscope (SEM).

  The number of 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.

(6) Substrate The substrate used in the present invention is a transparent substrate. As described above, the substrate is required to be transparent in order to expose the photosensitive resin layer from the substrate side using the patterned light-shielding portion as a mask in the first exposure step.
Examples of the transparent substrate include a glass substrate and a plastic substrate. Among these, a plastic substrate is preferably used. Although the plastic substrate has a large dimensional change, in the present invention, since high-precision alignment is not required, it is useful when a plastic substrate is used.

2. Light Shielding Part Forming Step In the present invention, a light shielding part forming step for forming a light shielding part in a pattern on the substrate may be performed before the partition forming step.

The light shielding part used in the present invention is appropriately selected depending on the use of the liquid crystal display element substrate obtained by the present invention.
For example, when the liquid crystal display element substrate is a TFT substrate, as described above, a gate electrode, a source electrode, a drain electrode, a TFT, and the like are formed as the light shielding portion. In this case, an auxiliary capacitor may be formed as the light shielding portion.
Further, for example, when the liquid crystal display element substrate is a common electrode substrate, as described above, a black matrix is formed as the light shielding portion.
Each will be described below.

(1) Gate electrode, source electrode, and drain electrode The gate electrode, source electrode, and drain electrode used in the present invention drive a liquid crystal when a signal voltage is applied thereto.

  Although the gate electrode and the source electrode are arranged vertically and horizontally as illustrated in FIG. 1, both may have a light shielding property, or one of them may have a light shielding property. That is, both the gate electrode and the source electrode may be light shielding portions, or one of them may be a light shielding portion. In the case where both the gate electrode and the source electrode are light shielding portions, the unexposed areas of the photosensitive resin layer in the first exposure step have a matrix pattern corresponding to the gate electrode and the source electrode. Further, when either one of the gate electrode and the source electrode is a light shielding portion, an unexposed region of the photosensitive resin layer in the first exposure step has a stripe pattern corresponding to the gate electrode or the source electrode. Become.

When either one of the gate electrode and the source electrode has light shielding properties, the other has transparency.
As the light-shielding gate electrode, a general metal electrode can be used. Examples of the metal electrode include chromium, aluminum, tantalum, tungsten, titanium, molybdenum, and the like. In addition, a transparent conductor is used as the gate electrode having transparency, and examples thereof include indium oxide, tin oxide, and indium tin oxide (ITO).

  As the light-shielding source electrode, a general metal electrode can be used as in the case of the gate electrode. As the source electrode having transparency, a transparent conductor can be used as in the case of the gate electrode.

  Further, the drain electrode may have a light shielding property or may have transparency as in the case of the gate electrode and the source electrode.

  Since the metal electrode has a light shielding property, if the gate electrode, the source electrode and the drain electrode are metal electrodes, for example, when exposed from the substrate side in FIG. 2B, the gate electrode, the source electrode and the drain electrode are provided. The exposed area is not irradiated with exposure light and becomes an unexposed area.

  As a formation method of a gate electrode, a source electrode, and a drain electrode, chemical vapor deposition (CVD) method or physical vapor deposition (PVD) methods, such as sputtering method and an ion plating method, are mentioned.

(2) TFT
The TFT used in the present invention has at least a semiconductor layer.
The semiconductor layer is formed between the gate electrode, the source electrode, and the drain electrode, and is electrically connected to the gate electrode, the source electrode, and the drain electrode.
As this semiconductor layer, a semiconductor layer generally used for a TFT can be used, and examples thereof include amorphous silicon, polysilicon, single crystal silicon, and the like.

  Examples of the method for forming the semiconductor layer include a CVD method, or a PVD method such as a sputtering method or an ion plating method.

(3) Black matrix The black matrix used in the present invention is a liquid crystal display element using the substrate for a liquid crystal display element obtained according to the present invention, which prevents light leakage from the vicinity of the wiring and allows external light to enter the TFT. This is provided in order to prevent the occurrence of a leakage current during OFF.

Examples of the black matrix forming material include a resin containing a black colorant, or a metal or a metal compound such as chromium, chromium oxide, or chromium nitride. As a black matrix using a metal or a metal compound, for example, a CrO _x film (x is an arbitrary number) and a Cr film laminated in two layers may be used, and CrO with a further reduced reflectivity may be used. Three layers of an _x film (x is an arbitrary number), a CrN _y film (y is an arbitrary number), and a Cr film may be laminated.

  A black matrix using a resin containing a black colorant is formed by applying a photosensitive resin composition containing a black colorant to form a coating film, and then patterning the coating film using a photolithography method. Can be formed.

  In addition, a black matrix using a metal or a metal compound can be formed by forming a thin film by a sputtering method, a vacuum deposition method, or the like, and patterning the thin film using a photolithography method. Further, the black matrix can be formed by using an electroless plating method, a printing method, or the like.

  The thickness of the black matrix can be about 0.2 μm to 0.4 μm when a sputtering method or a vacuum deposition method is used, and about 0.5 μm to 2 μm when a coating method or a printing method is used.

3. Electrode Layer Forming Step In the present invention, an electrode layer forming step for forming an electrode layer on the substrate may be performed before the partition forming step. This electrode layer forming step may be performed before the light shielding portion forming step or after the light shielding portion forming step. The order of the light shielding part forming step and the electrode layer forming step is appropriately selected according to the use of the liquid crystal display element substrate obtained by the present invention.

  The electrode layer used in the present invention is a transparent electrode. In the first exposure step, the photosensitive resin layer is exposed from the substrate side on which the electrode layer and the patterned light-shielding portion are formed using the patterned light-shielding portion as a mask, so that the electrode layer is transparent Is required.

  As a material for forming the electrode layer, a transparent conductor is used, and for example, indium oxide, tin oxide, indium tin oxide (ITO) and the like are preferable.

  For example, when the liquid crystal display element substrate is applied to an active matrix type liquid crystal display element using TFT, and the liquid crystal display element substrate is a TFT substrate, the electrode layer is a pixel electrode. . On the other hand, when the liquid crystal display element substrate is a common electrode substrate, the electrode layer is a common electrode.

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

4). Alignment film forming step In the present invention, after the light shielding portion forming step and the electrode layer forming step, an alignment film forming step of forming an alignment film on the substrate on which the electrode layer and the patterned light shielding portion are formed is performed. May be. This alignment film formation step may be performed before the partition formation step or after the partition formation step.

  The alignment film used in the present invention is not particularly limited as long as the alignment of the liquid crystal can be controlled. As the alignment film, for example, a rubbing alignment film subjected to a rubbing process, a photo alignment film subjected to a photo alignment process, or the like can be used. Among these, it is preferable to use a photo-alignment film. This is because 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.

  The photo-alignment film is anisotropic to the film obtained by irradiating the substrate coated with the constituent material of the photo-alignment film, which will be described later, with light whose polarization is controlled to cause a photoexcitation reaction (decomposition, isomerization, dimerization). Is used to align the liquid crystal molecules on the film.

  The constituent material of the photo-alignment film used in the present invention is not particularly limited as long as it has an effect of aligning liquid crystals (photoalignment) by irradiating light to cause a photoexcitation reaction. . As such materials, there are large photoreactive materials that impart anisotropy to the photoalignment film by causing a photoreaction, and anisotropy is imparted to the photoalignment film by causing a photoisomerization reaction. It can be divided into photoisomerization type materials.

The wavelength region of the light that causes the photo-excited reaction of the constituent material of the photo-alignment film 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.
Hereinafter, the photoreactive material and the photoisomerization type material will be described.

(1) Photoreactive type The photoreactive type material is a material that imparts anisotropy to the photo-alignment film by causing a photoreaction. The photoreactive material used in the present invention is not particularly limited as long as it has such characteristics. Among these, the photo-alignment is caused by causing a photodimerization reaction or a photodecomposition reaction. A material that imparts anisotropy to the film is preferred.

  Here, the photodimerization reaction refers to a reaction in which a reaction site oriented in the polarization direction by light irradiation undergoes radical polymerization and two molecules are polymerized. This reaction stabilizes the orientation in the polarization direction and makes the photo-alignment film different. It is possible to impart directionality. The photolysis reaction is a reaction that decomposes molecular chains such as polyimide oriented in the polarization direction by light irradiation. This reaction leaves a molecular chain oriented in the direction perpendicular to the polarization direction, and is different from the photo-alignment film. It is possible to impart directionality. In the present invention, among these photoreactive materials, it is more preferable to use a material that imparts anisotropy to the photoalignment film by a photodimerization reaction because of high exposure sensitivity and a wide range of material selection. .

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

  Examples of the photodimerization reactive compound having such characteristics include a dimerization reactive polymer having at least one reactive site selected from 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 photo-alignment film by radical polymerization of α and β unsaturated ketone double bonds aligned in the polarization direction as reaction sites.

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

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

  As a dimerization reactive polymer, the compound represented by following formula (1) can be illustrated.

In the above formula, M ¹¹ and M ¹² each independently represent a monomer unit of a monopolymer 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 a spacer unit.

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 (1-1) to (1-4).

  More specific examples of the dimerization reactive polymer include compounds represented by the following formulas (1-5) to (1-8).

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

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

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

  Examples of the photoreactive material utilizing photolysis reaction include polyimide “RN1199” manufactured by Nissan Chemical Industries, Ltd. Examples of the photoreactive material using photodimerization reaction include “ROP102” and “ROP103” manufactured by Rolic technologies.

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

  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 photo-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 either the cis isomer or the trans isomer is increased by light irradiation, whereby anisotropy can be imparted to the photo-alignment film.

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

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

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

  In this case, the number of cis-trans isomerization reactive skeletons contained in the molecule may be one or two or more. However, liquid crystal alignment control, particularly ferroelectric liquid crystal alignment control. It is preferable that the number is two.

  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 according to the type of 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 photo-alignment film becomes greater, and the alignment control of the liquid crystal, particularly the alignment of the ferroelectric liquid crystal. This is because it is particularly suitable for control. 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 liquid crystals, particularly for aligning ferroelectric liquid crystals.

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

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

  Among such compounds having an azobenzene skeleton in the molecule, examples of the monomolecular compound include compounds represented by the following formula (2).

In the above formula, 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 above formula include compounds represented by the following formulas (2-1) to (2-4).

  Moreover, as a polymerizable monomer which has the said azobenzene skeleton as a side chain, the compound represented by following formula (3) can be mentioned, for example.

In the above formula, each R ⁵¹ is independently (meth) acryloyloxy group, (meth) acrylamide group, vinyloxy group, vinyloxycarbonyl group, vinyliminocarbonyl group, vinyliminocarbonyloxy group, vinyl group, isopropenyloxy. Represents a group, isopropenyloxycarbonyl group, isopropenyliminocarbonyl group, isopropenyliminocarbonyloxy group, isopropenyl group or epoxy group. R 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 above formula include compounds represented by the following formulas (3-1) to (3-4).

  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.

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

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

(3) Forming method of photo-alignment film In order to form the photo-alignment film in the present invention, first, a photo-alignment film-forming coating solution obtained by diluting the constituent material of the photo-alignment film with an organic solvent is applied and dried. In this case, the content of the photodimerization reactive compound or the photoisomerization reactive compound in the photoalignment film forming coating solution is preferably in the range of 0.05 wt% to 10 wt%. More preferably, it is in the range of 2 wt% to 2 wt%. If the content is less than the above range, it becomes difficult to impart appropriate anisotropy to the alignment film. Conversely, if the content is more than the above range, the viscosity of the photo-alignment film-forming coating solution increases. This is because it becomes difficult to form a uniform coating film.

  Examples of the application method of the coating liquid for forming a photo-alignment film include spin coating, roll coating, rod bar coating, spray coating, air knife coating, slot die coating, wire bar coating, ink jet, and flexographic printing. Method, screen printing method and the like can be used.

  The thickness of the film obtained by applying the coating liquid for forming a photo-alignment film is preferably in the range of 1 nm to 2000 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 optical alignment may not be obtained, and conversely, if the thickness is thicker than the above range, it may be disadvantageous in cost.

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

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

5. Reactive Liquid Crystal Layer Forming Step In the present invention, a reactive liquid crystal layer forming step for forming a reactive liquid crystal layer formed by fixing reactive liquid crystals on the alignment film may be performed after the alignment film forming step.

  The reactive liquid crystal is aligned by an alignment film. For example, the reactive liquid crystal layer can be formed by polymerizing the reactive liquid crystal by irradiating ultraviolet rays and fixing the alignment state. The reactive liquid crystal layer is formed by fixing the alignment state of the reactive liquid crystal as described above, and thus functions as an alignment film for aligning the liquid crystal. Further, since the reactive liquid crystal is fixed, it has an advantage that it is not affected by temperature or the like. Furthermore, since the reactive liquid crystal has a relatively similar structure to the liquid crystal and has a strong interaction with the liquid crystal, the alignment of the liquid crystal can be controlled more effectively than when only the alignment film is used.

  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.

  As a monoacrylate monomer, the compound represented by following formula (4) and (5) can be illustrated, for example.

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

  Examples of the diacrylate monomer include compounds represented by the following formulas (6) and (7).

In the above formula, X and Y are hydrogen, alkyl having 1 to 20 carbons, alkenyl having 1 to 20 carbons, alkyloxy having 1 to 20 carbons, alkyloxycarbonyl having 1 to 20 carbons, formyl, carbon number 1-20 alkylcarbonyl, C1-C20 alkylcarbonyloxy, halogen, cyano or nitro is represented. M represents an integer in the range of 2-20. In the above formula (6), X is preferably an alkyloxycarbonyl having 1 to 20 carbon atoms, methyl or chlorine, and especially an alkyloxycarbonyl having 1 to 20 carbon atoms, especially CH ₃ (CH ₂ ) ₄ OCO. It is preferable that

  Moreover, as a diacrylate monomer, the compound shown, for example to following formula (8) can be mentioned.

In the above formula, Z ³¹ and Z ³² are each independently independently directly bonded —COO—, —OCO—, —O—, —CH ₂ CH ₂ —, —CH═CH—, —C≡C—. , —OCH ₂ —, —CH ₂ O—, —CH ₂ CH ₂ COO—, —OCOCH ₂ CH ₂ —, wherein R ³¹ , R ³² and R ³³ are each independently hydrogen or carbon number 1 to 5 Represents 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 (8) include compounds represented by the following formula (8-1).

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

  In the present invention, among the above, compounds represented by the above formulas (6) and (8) are preferably used. Specific examples of the compound represented by the above formula (8) include “Adeka Kiracol PLC-7183” and “Adeka Kiracol PLC-7209” manufactured by Asahi Denka Kogyo Co., Ltd. Examples of the acrylate monomer include “ROF-5101” and “ROF-5102” manufactured by Rolic technologies.

  In the present invention, among 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 does not have to exhibit 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, in this invention, 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. This is because the agent is used for promoting the polymerization.

  Examples of the photopolymerization initiator that can be used in the present invention include benzyl (also referred to as bibenzoyl), benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, benzoylbenzoic acid, benzoylmethyl benzoate, and 4-benzoyl-4′-methyldiphenyl. Sulfide, benzylmethyl ketal, dimethylaminomethylbenzoate, 2-n-butoxyethyl-4-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, 3,3′-dimethyl-4-methoxybenzophenone, methylobenzoylformate, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropyl Phenyl) -2-hydroxy-2-methylpropan-1-one, 2-chlorothioxanthone, 2,4-diethylthioxanthone 2,4-diisopropylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 1-chloro-4- And propoxythioxanthone. 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.

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

  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.

  The reactive liquid crystal layer may be formed by applying a reactive liquid crystal layer forming coating liquid containing a reactive liquid crystal on the alignment film, performing an alignment treatment, and fixing the alignment state of the reactive liquid crystal. it can. Further, the reactive liquid crystal layer may be formed by forming a dry film or the like in advance and laminating it on the alignment film, instead of applying the coating liquid for forming the reactive liquid crystal layer. From the viewpoint of simplicity of the manufacturing process, it is possible to prepare a reactive liquid crystal layer-forming coating solution by dissolving reactive liquid crystal in a solvent, apply this onto the alignment film, and use a method of removing the solvent. preferable.

  The solvent used in the coating liquid for forming the reactive liquid crystal layer is not particularly limited as long as it can dissolve the reactive liquid crystal and the like and does not inhibit the alignment ability of the alignment film. For example, hydrocarbons such as benzene, toluene, xylene, n-butylbenzene, diethylbenzene and tetralin; ethers such as methoxybenzene, 1,2-dimethoxybenzene and diethylene glycol dimethyl ether; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 2 Ketones such as 1,4-pentanedione; esters such as ethyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, γ-butyrolactone; 2-pyrrolidone, N-methyl-2-pyrrolidone, dimethylformamide, dimethyl Amide solvents such as acetamide; t-butyl alcohol, diacetone alcohol, glycerin, monoacetin, ethylene glycol, triethyleneglycol 1 or 2 types of alcohols such as phenol and hexylene glycol; phenols such as phenol and parachlorophenol; cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, and ethylene glycol monomethyl ether acetate; is there.

  Further, if only a single kind of solvent is used, the solubility of the reactive liquid crystal or the like may be insufficient or the alignment film may be eroded. 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 a mixed system of ethers or ketones and glycol solvent is preferable as the mixed solvent. It is.

  The concentration of the coating liquid for forming the reactive liquid crystal layer depends on the solubility of the reactive liquid crystal and the thickness of the reactive liquid crystal layer, but cannot be defined unconditionally, but is usually 0.1 to 40% by weight, preferably It is adjusted in the range of 1 to 20% by weight. When the 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, and conversely when the concentration of the reactive liquid crystal layer forming coating liquid is higher than the above range, This is because the viscosity of the coating liquid for forming a reactive liquid crystal layer is increased, so that 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, and spray coating. Method, gravure coating method, reverse coating method, extrusion coating method, ink jet method, flexographic printing method, screen printing method and the like.

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

  In the present invention, the reactive liquid crystal applied as described above is aligned by the alignment film 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 below the NI transition point. Here, the NI transition point indicates the temperature at which the liquid crystal phase transitions to the isotropic phase.

  The reactive liquid crystal has a polymerizable liquid crystal material, and in order to fix the alignment state of such a polymerizable liquid crystal material, a method of irradiating actinic radiation that activates polymerization is used. As used herein, active radiation refers to radiation that has the ability to cause polymerization of a polymerizable liquid crystal material.

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

  In the present invention, 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 a preferable method. . 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 a light source of this irradiation light, a low pressure mercury lamp (sterilization lamp, fluorescent chemical lamp, black light), a high pressure discharge lamp (high pressure mercury lamp, metal halide lamp), a 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.

  Further, 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 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.

6). Colored layer forming step In the present invention, for example, when a black matrix is formed in the light shielding portion forming step and a common electrode is formed in the electrode layer forming step, the electrode layer forming step is performed after the light shielding portion forming step. A colored layer forming step of forming a colored layer on a substrate on which a patterned light-shielding portion (black matrix) is formed may be performed before.
In the case where a colored layer is formed, in a liquid crystal display element using a liquid crystal display element substrate, color display can be realized by the colored layer.

  The colored layer used in the present invention is not particularly limited as long as it is generally used as a colored layer of a color filter. For example, a colored layer can be formed using a colored layer forming composition containing a red, green, or blue pigment.

  As a method for forming the colored layer, a general method can be applied, and examples thereof include a photolithography method, an ink jet method, and a screen printing method.

7). Use The liquid crystal display element substrate obtained by the present invention can be applied to, for example, an active matrix liquid crystal display element using TFTs.

  FIG. 5 is a perspective view showing an example of an active matrix type liquid crystal display element using a TFT, which is a liquid crystal display element using a liquid crystal display element substrate obtained by the present invention. As illustrated in FIG. 5, the liquid crystal display element 60 includes a liquid crystal display element substrate 10 (TFT substrate) and a counter substrate 50 (common electrode substrate). In the counter substrate 50 (common electrode substrate), a common electrode 52 and an alignment film 53 are formed on a base material 51. A pixel electrode 2, a gate electrode 3a, a source electrode 3b, a drain electrode 3c, and a TFT 4 are formed on the liquid crystal display element substrate 10 (TFT substrate). The gate electrode 3a and the source electrode 3b are arranged vertically and horizontally, respectively, and by applying a signal to the gate electrode 3a and the source electrode 3b, the TFT 4 can be operated to drive the liquid crystal. A portion where the gate electrode 3a and the source electrode 3b intersect with each other is insulated by an insulating layer (not shown), and the signal of the gate electrode 3a and the signal of the source electrode 3b can operate independently. A portion surrounded by the gate electrode 3a and the source electrode 3b is a pixel which is a minimum unit for driving the liquid crystal display element, and at least one TFT 4 and a pixel electrode 2 are formed in each pixel. Then, by sequentially applying a signal voltage to the gate electrode and the source electrode, the TFT of each pixel can be operated. In FIG. 5, the liquid crystal layer and the alignment film of the liquid crystal display element substrate are omitted.

  In the example shown in FIG. 5, the liquid crystal display element substrate is a TFT substrate. However, the present invention is not limited to this, and the liquid crystal display element substrate may be a TFT substrate or a common electrode substrate. Also good. Among them, the liquid crystal display element substrate is preferably a TFT substrate. Since the arrangement of each constituent member is complicated in the TFT substrate, high-precision alignment is required when forming the partition wall. However, since precise alignment is not required in the present invention, it is useful for manufacturing the TFT substrate. It is.

8). Liquid Crystal Display Element FIG. 6 is a schematic sectional view showing an example of a liquid crystal display element using a liquid crystal display element substrate obtained by the present invention. In the liquid crystal display element 60 illustrated in FIG. 6, the pixel electrode 2 and the source electrode 3 b are formed on the substrate 1, the partition 6 ′ is formed on the source electrode 3 b, and the pixel electrode 2, the source electrode 3 b and the partition are formed. A liquid crystal display element substrate 10 (TFT substrate) in which an alignment film 7 is formed on 6 ′ and the like, and a counter substrate 50 (common electrode substrate) in which a common electrode 52 and an alignment film 53 are sequentially formed on a base material 51. The liquid crystal is sandwiched between the alignment film 7 of the liquid crystal display element substrate 10 (TFT substrate) and the alignment film 53 of the counter substrate 50 (common electrode substrate), and a liquid crystal layer 55 is formed. ing.
Hereinafter, a liquid crystal layer in such a liquid crystal display element will be described.

(1) Liquid crystal layer The liquid crystal layer is configured by sandwiching liquid crystal between alignment films.
The liquid crystal is not particularly limited, and examples thereof include nematic liquid crystal, cholesteric liquid crystal, smectic liquid crystal, and ferroelectric liquid crystal.

  Among the above, ferroelectric liquid crystal is preferable. In general, a ferroelectric liquid crystal having a phase sequence passing through an SmA phase as exemplified in the lower part of FIG. 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 series that does not pass through the SmA phase as exemplified in the upper part of FIG. 7 is likely to generate two regions (double domains) having different layer normal directions. In the present invention, the formation of the partition walls can suppress the occurrence of such alignment defects.

The ferroelectric liquid crystal is not particularly limited as long as it exhibits a chiral smectic C phase (SmC ^* ). Examples of the phase series of the ferroelectric liquid crystal include those that change phase with a nematic (N) phase-cholesteric (Ch) phase-chiral smectic C (SmC ^* ) phase, and a nematic (N) phase-chiral smectic C (SmC ^*). ) Phase change, nematic (N) phase-smectic A (SmA) phase-chiral smectic C (SmC ^* ) phase change, nematic (N) phase-cholesteric (Ch) phase-smectic A ( SmA) -phase-chiral smectic C (SmC ^* ) phase and the like.

  Among these, ferroelectric liquid crystal that does not pass through the SmA phase is preferable. As described above, the ferroelectric liquid crystal that does not pass through the SmA phase easily causes alignment defects such as double domains. However, the formation of the partition effectively suppresses the occurrence of alignment defects such as double domains. Because it can.

  As the ferroelectric liquid crystal, there are two bistable ones proposed by Clark and Lagerwol having two stable states when no voltage is applied (the upper part of FIG. 8), and one state of the liquid crystal layer when no voltage is applied. (Hereinafter referred to as “monostable”) (NONAKA, T., LI, J., OGAWA, A., HORNUNG, B., SCHMIDT, W. , WINGEN, R., and DUBAL, H., 1999, Liq. Cryst., 26, 1599.). Among these, ferroelectric liquid crystal exhibiting monostability is preferable. When using ferroelectric liquid crystal exhibiting monostability, gradation display is possible by continuously changing the director of the liquid crystal (inclination of the molecular axis) by voltage change and analog modulation of the transmitted light intensity. Because it becomes.

  In particular, when the liquid crystal display element is driven by a field sequential color method, it is preferable to use a liquid crystal material exhibiting monostability. By using a liquid crystal material exhibiting monostability, it is possible to drive with an active matrix method using TFTs, and to control gradation by voltage modulation, realizing high-definition and high-quality display. Because you can.

  “Showing monostability” means a state in which the state of the ferroelectric liquid crystal when no voltage is applied is stabilized in one state. As illustrated in FIG. 9, the ferroelectric liquid crystal rotates along a cone ridge line in which the liquid crystal molecules 56 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 56 with respect to the layer normal z is referred to as a tilt angle θ. Thus, the liquid crystal molecules 56 can operate on the cone between two states inclined by a tilt angle ± θ with respect to the layer normal z. More specifically, the expression of monostability refers to a state in which the liquid crystal molecules 56 are stabilized in any one state on the cone when no voltage is applied.

Among liquid crystal materials exhibiting monostability, for example, as shown in the lower left of FIG. 8, liquid crystal molecules operate only when a positive or negative voltage is applied, which is hereinafter referred to as HV-shaped switching. .) Those exhibiting properties are particularly preferred. When the ferroelectric liquid crystal exhibiting such HV-shaped switching characteristics is used, the opening time as a black and white shutter can be made sufficiently long, whereby each color that can be temporally switched can be displayed brighter. This is because a bright color display liquid crystal display element can be realized.
The “HV-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 HV-shaped switching characteristics. 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 and Zb represent —COO—, —OCO—, —CH ₂ O—, —OCH ₂ —, —CH ₂ CH _{2, respectively.} -, -C≡C-, -CH = N-, -N = N-, -N (→ O) = N-, -C (= O) S- or a single bond, and Rc is an asymmetric carbon atom. A linear or branched alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkanoyloxy group or an alkoxycarbonyloxy group, which may have Rd is a linear or branched alkyl group having an asymmetric carbon atom An alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkanoyloxy group or an alkoxycarbonyloxy group, wherein Rc and Rd may be substituted with a halogen atom, a cyano group or a hydroxyl group). can do. 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.

  When a ferroelectric liquid crystal is used as the liquid crystal, the liquid crystal layer may contain other compounds in addition to the ferroelectric liquid crystal. As other compounds, those having an arbitrary function can be used depending on the function required for the liquid crystal display element. Examples of other compounds that can be suitably used include a polymer of a polymerizable monomer. This is because when the polymer of the polymerizable monomer is contained in the liquid crystal layer, the alignment of the ferroelectric liquid crystal is so-called “polymer stabilization” and excellent alignment stability is obtained.

  The polymerizable monomer is not particularly limited as long as it is a compound that generates a polymer by a polymerization reaction. Examples of the polymerizable monomer include a thermosetting resin monomer that causes a polymerization reaction by heat treatment, and an actinic radiation curable resin monomer that causes a polymerization reaction by irradiation with actinic radiation. 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 in the liquid crystal layer, so that the intermolecular force and the polymer network at the alignment film interface can be strengthened. Thereby, disorder of the alignment of the ferroelectric liquid crystal due to the temperature change of the liquid crystal layer 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 polymerizable functional groups at both ends of the molecule, it is possible to form a polymer network in which the distance between the polymers is wide, and the driving voltage of the ferroelectric liquid crystal is reduced due to the liquid crystal layer containing a polymer of a polymerizable monomer. It is because it can prevent.

  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. The presence of the polymer having such a regular alignment state in the liquid crystal layer can improve the alignment stability of the ferroelectric liquid crystal, and can obtain excellent heat resistance and impact resistance. .

  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 (4), (5) and (7).

In the above formulas (4) and (5), 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 (7), 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, formyl Represents alkylcarbonyl having 1 to 20 carbon atoms, alkylcarbonyloxy having 1 to 20 carbon atoms, halogen, cyano or nitro.

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

  The polymer of the polymerizable monomer may be a polymer of a single polymerizable monomer or a polymer of two or more different polymerizable monomers. In the case of using a polymer of two or more different polymerizable monomers, for example, a polymer of an ultraviolet curable liquid crystal monomer represented by the above formula and another ultraviolet curable resin monomer can be exemplified.

  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 the atomic group exhibiting liquid crystallinity in the side chain increases the degree of freedom of the atomic group, and therefore the atomic group exhibiting liquid crystallinity is easily aligned in the liquid crystal layer. Further, as a result, the alignment stability of the ferroelectric liquid crystal can be improved.

  The amount of the polymerized polymerizable monomer in the liquid crystal layer is not particularly limited as long as it is within a range in which the alignment stability of the ferroelectric liquid crystal can be set to a desired level, but is 0.5% by mass to 30% by mass. Within the range, 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 the amount of the polymerized monomer is larger than the above range, the driving voltage of the ferroelectric liquid crystal may increase or the response speed may decrease. Further, when the amount of the polymerizable monomer polymer is less than the above range, the alignment stability of the ferroelectric liquid crystal becomes insufficient, and the heat resistance and impact resistance may be lowered.

  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 weighing 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 appropriately selected according to the type of liquid crystal used. For example, when a ferroelectric liquid crystal is used, 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, still more preferably 1.4 μm to It is in the range of 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. For example, when nematic liquid crystal is used, the thickness of the liquid crystal layer is preferably in the range of 2 μm to 30 μm, more preferably in the range of 2 μm to 5 μm.

As a method for forming the liquid crystal layer, a method generally used as a method for manufacturing a liquid crystal cell can be used, and examples thereof include a vacuum injection method and a liquid crystal dropping method.
In the vacuum injection method, for example, a liquid crystal cell is prepared in advance using a substrate for a liquid crystal display element and a counter substrate, and the liquid crystal is heated to obtain an isotropic liquid. The liquid crystal layer can be formed by injecting in the state of an isotropic liquid and sealing with an adhesive. Thereafter, the sealed liquid crystal can be aligned by slowly cooling the liquid crystal cell to room temperature.
In the liquid crystal dropping method, for example, a sealing agent is applied to the periphery of the liquid crystal display element substrate, the liquid crystal display element substrate is heated to a temperature at which the liquid crystal becomes isotropic, and the alignment film of the liquid crystal display element substrate is used. A liquid crystal layer is formed by dropping liquid crystal in an isotropic liquid state using a dispenser on top of the liquid crystal display element substrate and the counter substrate under reduced pressure and bonding them with a sealant. Can do. Thereafter, the sealed liquid crystal can be aligned by slowly cooling the liquid crystal cell to room temperature.

  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.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
[Example]
A PES substrate (size: 100 mm × 100 mm, thickness: 0.2 mm) in which a chromium film was formed in a matrix with a width of 10 μm and a pitch of 100 μm was prepared. On this substrate, a photosensitive resin material (OFPR, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied by spin coating (2000 rpm, 10 seconds), vacuum-dried, and dried at 90 ° C. for 3 minutes on a hot plate. A photosensitive resin layer was formed. Thereafter, the photosensitive resin layer was exposed from the substrate side.
Next, exposure was performed from the photosensitive resin layer side with respect to the photosensitive resin layer using a photomask in which the light shielding portion was formed in a stripe shape having a width of 100 μm and a pitch of 2 mm. Subsequently, it baked for 30 minutes at 230 degreeC, and the partition which consists of photosensitive resins was formed.
As a result, barrier ribs formed in a stripe shape having a width of 10 μm and a pitch of 2 mm on the chromium film pattern were obtained.

[Comparative example]
A PES substrate (size: 100 mm × 100 mm, thickness: 0.2 mm) in which a chromium film was formed in a matrix with a width of 10 μm and a pitch of 100 μm was prepared. On this substrate, a photosensitive resin material (OFPR, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied by spin coating (2000 rpm, 10 seconds), vacuum-dried, and dried at 90 ° C. for 3 minutes on a hot plate. A photosensitive resin layer was formed.
Next, the photosensitive resin layer was exposed from the photosensitive resin layer side using a photomask in which the light shielding portions were formed in a stripe shape having a width of 10 μm and a pitch of 100 μm. Subsequently, it baked for 30 minutes at 230 degreeC, and the partition which consists of photosensitive resins was formed.
When heating with the above hot plate, the shape change of the PES substrate was caused by heat. Therefore, when the photosensitive resin layer was exposed, the alignment marks of the photomask and the substrate were not aligned, and the partition wall was displaced from the chromium film pattern. Been formed.

It is process drawing which shows an example of the manufacturing method of the board | substrate for liquid crystal display elements of this invention. It is process drawing which shows the other example of the manufacturing method of the board | substrate for liquid crystal display elements of this invention. It is process drawing which shows the other example of the manufacturing method of the board | substrate for liquid crystal display elements of this invention. It is process drawing which shows the other example of the manufacturing method of the board | substrate for liquid crystal display elements of this invention. It is a schematic perspective view which shows an example of the liquid crystal display element using the board | substrate for liquid crystal display elements. It is a schematic sectional drawing which shows an example of the liquid crystal display element using the board | substrate for liquid crystal display elements. 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 the graph which showed the change of the transmittance | permeability with respect to the applied voltage of a ferroelectric liquid crystal. It is a schematic diagram which shows the behavior of a liquid crystal molecule.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 21 ... Base material 2 ... Pixel electrode 3a ... Gate electrode 3b ... Source electrode 3c ... Drain electrode 4 ... TFT
6, 26 ... photosensitive resin layer 6 ', 26' ... partition 7 ... alignment film 10 ... substrate for liquid crystal display element 11 ... photomask 16a, 36a ... unexposed area 16b, 36b ... exposed area 22 ... black matrix 23 ... coloring Layer 24 ... Common electrode

Claims (3)

A base material, an electrode layer formed on the base material, a light shielding part formed in a pattern on the base material, and a pattern different from the pattern of the light shielding part on the light shielding part, A method for producing a substrate for a liquid crystal display element having a partition made of a positive photosensitive resin,
A photosensitive resin layer forming step of forming a photosensitive resin layer made of the positive photosensitive resin on the substrate on which the electrode layer and the patterned light-shielding portion are formed;
A first exposure step of exposing the photosensitive resin layer from the substrate side;
After the first exposure step, a second exposure step of exposing the photosensitive resin layer from the photosensitive resin layer side through a photomask;
A development step of developing the photosensitive resin layer after the second exposure step to form the partition; and a method of manufacturing a substrate for a liquid crystal display element.   The method for producing a substrate for a liquid crystal display element according to claim 1, wherein the substrate for a liquid crystal display element is used for a liquid crystal display element using a ferroelectric liquid crystal.   3. The liquid crystal display element substrate according to claim 1, wherein the electrode layer is a pixel electrode, and the light shielding portion is a gate electrode, a source electrode, a drain electrode, and a thin film transistor (TFT). Method.

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