JP4848918B2 - Manufacturing method of liquid crystal display element - Google Patents

Description

  The present invention relates to a method for manufacturing a liquid crystal display element using a ferroelectric liquid crystal by a liquid crystal dropping (One Drop Fill: ODF) method.

  Liquid crystal display elements have been widely used from large displays to portable information terminals because of their thinness and low power consumption, and their development is actively underway. So far, liquid crystal display elements have been developed and put to practical use, such as TN mode, STN multiplex drive, and active matrix drive using thin layer transistors (TFTs) for TN, but these use nematic liquid crystals. In addition, the response speed of the liquid crystal material is as slow as several ms to several tens of ms, and it cannot be said that it is sufficiently compatible with moving image display. On the other hand, the ferroelectric liquid crystal (FLC) is a liquid crystal suitable for a high-speed device because the response speed is as short as μs order.

  In recent years, a liquid crystal dropping method has attracted attention as a liquid crystal sealing method. This is because a sealing agent is applied to one of a pair of substrates so as to surround a liquid crystal sealing region, liquid crystal is dropped on the substrate, and then both substrates are superposed in a state where the pressure between both substrates is sufficiently reduced. It sticks together. The liquid crystal dropping method has an advantage that the time required for the liquid crystal sealing step is significantly shortened as compared with the vacuum injection method.

In general, a ferroelectric liquid crystal has a higher viscosity than a nematic liquid crystal. Therefore, when the ferroelectric liquid crystal is dropped, the ferroelectric liquid crystal is previously set to a temperature at which the ferroelectric liquid crystal is in a low viscosity state (a temperature at which the ferroelectric liquid crystal is in a cholesteric phase, a nematic phase, or an isotropic phase). It has been disclosed to heat a conductive liquid crystal (see, for example, Patent Document 1).
At this time, the substrate on which the ferroelectric liquid crystal is dropped is preheated to the vicinity of the nematic phase-isotropic phase transition temperature of the ferroelectric liquid crystal, or the smectic A phase-cholesteric phase transition temperature higher than the cholesteric phase-etc. It has been disclosed to preheat to a temperature that is equal to or lower than the phase transition temperature (see, for example, Patent Document 2 and Patent Document 3).

JP-A-6-160874 JP-A-6-194615 JP-A-10-186384

  However, in the liquid crystal dropping method, the ferroelectric liquid crystal is exposed to air while the ferroelectric liquid crystal is dropped on the substrate, and further, the ferroelectric liquid crystal is heated while being exposed to the air. Therefore, the ferroelectric liquid crystal may be deteriorated.

  Further, in this method, the ferroelectric liquid crystal and the substrate are heated as described above, and when the ferroelectric liquid crystal dropped on the substrate is in an isotropic phase state, it becomes colorless and transparent. For this reason, it is difficult to visually recognize whether or not the ferroelectric liquid crystal is dropped at a desired position on the substrate. Further, since the ferroelectric liquid crystal in the cholesteric phase or nematic phase has a relatively low viscosity, it does not stay at the dropping position but spreads out. Therefore, the ferroelectric liquid crystal is partially dropped. Even if there is no area, it is difficult to accurately identify the area. Also, since it generally takes time to inspect the defective dropping of the transparent liquid by means other than visual observation, a ferroelectric liquid crystal is dropped on one substrate, and the two substrates are bonded together, and the resulting liquid crystal display element In many cases, defects are finally inspected. For this reason, the yield of a liquid crystal display element falls.

  The present invention has been made in view of the above problems, and a main object of the present invention is to provide a method of manufacturing a liquid crystal display element by a liquid crystal dropping method using a ferroelectric liquid crystal having a high yield.

  In order to achieve the above object, according to the present invention, a liquid crystal side substrate in which a first electrode layer and a first alignment film are laminated in this order on a first substrate is set at a temperature at which the ferroelectric liquid crystal exhibits a smectic phase. After the setting, a liquid crystal application step of applying the ferroelectric liquid crystal on the first alignment film so that the ferroelectric liquid crystal applied on the first alignment film of the liquid crystal side substrate is in a smectic phase state. And an inspection process for inspecting for the presence or absence of a coating defect in the ferroelectric liquid crystal, and when the application defect is detected in the inspection process, the ferroelectric liquid crystal is discharged to a defective portion on the first alignment film. A substrate in which a correction step applied by a method, a liquid crystal side substrate coated with the ferroelectric liquid crystal, and a counter substrate in which a second electrode layer and a second alignment film are laminated in this order on a second base material are bonded together And a bonding process. To provide a method of manufacturing a liquid crystal display device.

According to the present invention, since the liquid crystal side substrate is set to a temperature at which the ferroelectric liquid crystal exhibits a smectic phase, the ferroelectric liquid crystal applied on the liquid crystal side substrate can be instantaneously cooled to a temperature at which the smectic phase is exhibited. . In addition, when the ferroelectric liquid crystal immediately after being applied on the substrate is in a smectic phase state, the ferroelectric liquid crystal is clouded, so that a coating defect of the ferroelectric liquid crystal can be easily detected. . Further, when a coating defect is detected, a ferroelectric liquid crystal can be applied to the defective portion to correct the coating defect. As a result, the yield can be improved.
In general, since the ferroelectric liquid crystal in the smectic phase state has a relatively high viscosity, even if the ferroelectric liquid crystal is applied on the liquid crystal side substrate, it does not easily spread. For this reason, it is possible to reduce the area where the ferroelectric liquid crystal comes into contact with air in the liquid crystal coating process. More generally, since the temperature at which the ferroelectric liquid crystal exhibits a smectic phase is around room temperature, the temperature of the liquid crystal side substrate can be set to room temperature. Therefore, it is possible to suppress the deterioration of the ferroelectric liquid crystal in the liquid crystal application process.

  In the above invention, in the liquid crystal application step, before applying the ferroelectric liquid crystal on the first alignment film, the ferroelectric liquid crystal is heated to a temperature showing a nematic phase or an isotropic phase, The ferroelectric liquid crystal coating method is preferably a discharge method. This is because the use of the discharge method can effectively suppress the alignment disorder that occurs when the ferroelectric liquid crystal flows. Further, when the ejection method is used, the ferroelectric liquid crystal can be stably ejected by heating the ferroelectric liquid crystal to a temperature showing a nematic phase or an isotropic phase.

  In the invention, the ferroelectric liquid crystal coating method may be a screen printing method. This is because even when the screen printing method is used, the alignment disorder generated when the ferroelectric liquid crystal flows can be effectively suppressed.

  Furthermore, in the present invention, it is preferable that the liquid crystal side substrate is a common electrode substrate, and the counter substrate is a thin film transistor (hereinafter sometimes abbreviated as TFT) substrate. Since the common electrode substrate is less expensive to manufacture than the TFT substrate, if the liquid crystal side substrate is a common electrode substrate, the loss cost may be reduced even if there is a coating defect in the ferroelectric liquid crystal that cannot be corrected. Because it can.

Hereafter, the manufacturing method of the liquid crystal display element of this invention is demonstrated in detail.
In the method for producing a liquid crystal display element of the present invention, a liquid crystal side substrate in which a first electrode layer and a first alignment film are laminated in this order on a first substrate is set to a temperature at which the ferroelectric liquid crystal exhibits a smectic phase. A liquid crystal application step of applying the ferroelectric liquid crystal on the first alignment film so that the ferroelectric liquid crystal applied on the first alignment film of the liquid crystal side substrate is in a smectic phase state; An inspection process for inspecting the presence or absence of a coating defect in the ferroelectric liquid crystal, and a method for discharging the ferroelectric liquid crystal to a defective portion on the first alignment film when a coating defect is detected in the inspection process. A step of applying a correction step, a liquid crystal side substrate coated with the above-mentioned ferroelectric liquid crystal, and a substrate pasting a counter substrate in which a second electrode layer and a second alignment film are laminated in this order on a second base material And a combining step Than is.

  The manufacturing method of the liquid crystal display element of this invention is demonstrated referring drawings. 1-3 is a figure which shows an example of the manufacturing method of the liquid crystal display element of this invention, FIG.2 (a) is the sectional view on the AA line of FIG. 1, FIG.2 (b) is FIG. It is a BB sectional view.

  First, as shown in FIG. 1 and FIG. 2A, the liquid crystal side substrate 2a is set to a temperature at which the ferroelectric liquid crystal exhibits a smectic phase, and the ferroelectric liquid crystal to be applied is isotropic. The ferroelectric liquid crystal 3 is applied to the first alignment film 7a of the liquid crystal side substrate 2a in the form of a stripe in the form of stripes by using an ink jet device (liquid crystal application step). Next, as shown in FIG. 1, the presence or absence of a coating defect of the ferroelectric liquid crystal 3 is inspected (inspection process).

Here, the phase series of the ferroelectric liquid crystal used in the present invention includes, for example, an isotropic phase-nematic (N) phase-cholesteric (Ch) phase-chiral smectic C (SmC ^* ) phase and phase in the temperature lowering process. Change, isotropic phase-nematic (N) phase-chiral smectic C (SmC ^* ) phase change, isotropic phase-nematic (N) phase-smectic A (SmA) phase-chiral smectic C (SmC) ^* ) What changes phase with phase, Isotropic phase-Nematic (N) phase-Cholesteric (Ch) phase-Smectic A (SmA) phase-What changes phase with chiral smectic C (SmC ^* ) phase, etc. Can do.

The temperature at which the ferroelectric liquid crystal exhibits a smectic phase refers to a temperature at which the ferroelectric liquid crystal exhibits a smectic phase such as a chiral smectic C (SmC ^* ) phase or a smectic A (SmA) phase.

  In the above example, the ferroelectric liquid crystal 3 is heated to a temperature exhibiting an isotropic phase, but the liquid crystal side substrate 2a is set to a temperature at which the ferroelectric liquid crystal exhibits a smectic phase. The temperature of the liquid crystal side substrate is lower than the temperature of the crystalline liquid crystal. Further, even when the ferroelectric liquid crystal is heated to a temperature exhibiting a nematic phase, the temperature of the liquid crystal side substrate becomes lower than the temperature of the ferroelectric liquid crystal. For this reason, the ferroelectric liquid crystal applied on the liquid crystal side substrate is instantaneously cooled to a smectic phase.

  In general, the ferroelectric liquid crystal in the isotropic phase state is colorless and transparent, but the ferroelectric liquid crystal in the smectic phase state is cloudy. In the present invention, since the ferroelectric liquid crystal applied on the liquid crystal side substrate is instantaneously cooled to a smectic phase state, it is determined whether or not the ferroelectric liquid crystal is applied to a desired position on the liquid crystal side substrate. Visual recognition is possible. For example, as shown in FIG. 1, a coating defect of the ferroelectric liquid crystal 3 can be easily detected visually.

  Next, as shown in FIG. 1, when a coating defect of the ferroelectric liquid crystal 3 is detected, as shown in FIG. 3, the ferroelectric liquid crystal is brought to a temperature at which the ferroelectric liquid crystal exhibits an isotropic phase. Heating is performed, and the ferroelectric liquid crystal 3 is discharged to the defective portion 11 on the liquid crystal side substrate 2a using an ink jet device (correction step).

In the present invention, as described above, by setting the liquid crystal side substrate to a temperature at which the ferroelectric liquid crystal exhibits a smectic phase, it is visually confirmed whether or not the ferroelectric liquid crystal is applied to a desired position on the liquid crystal side substrate. Therefore, the application defect can be easily corrected by discharging the ferroelectric liquid crystal to the defective portion.
As described above, the yield of the liquid crystal display elements can be improved by performing the inspection process and the correction process.

Next, after applying the ferroelectric liquid crystal, as shown in FIGS. 3 and 2B, the sealant 4 is applied in a frame shape on the liquid crystal side substrate 2a so as to surround the liquid crystal sealing region.
Next, as shown in FIG. 2C, a liquid crystal side substrate 2a in which the first electrode layer 6a and the first alignment film 7a are laminated on the first base material 5a and the ferroelectric liquid crystal 3 is applied, The counter substrate 2b in which the second electrode layer 6b and the second alignment film 7b are stacked on the second base material 5b is disposed so that the first alignment film 7a and the second alignment film 7b face each other. At this time, the liquid crystal side substrate 2a and the counter substrate 2b are heated to a temperature at which the ferroelectric liquid crystal exhibits an isotropic phase. Next, the pressure between the liquid crystal side substrate 2a and the counter substrate 2b is sufficiently reduced, and the liquid crystal side substrate 2a and the counter substrate 2b are superposed under reduced pressure as shown in FIG. At this time, the ferroelectric liquid crystal spreads between the liquid crystal side substrate 2a and the counter substrate 2b. Then, a predetermined pressure is applied to the liquid crystal side substrate 2a and the counter substrate 2b to make the cell gap uniform, and the pressure is further applied by returning to the normal pressure. Next, the sealant 4 is heated and cured, and the liquid crystal side substrate 2a and the counter substrate 2b are bonded together (substrate bonding step). Thereafter, the encapsulated ferroelectric liquid crystal is aligned by slowly cooling to room temperature.

In general, the viscosity of liquid crystals increases as the temperature decreases. For example, a ferroelectric liquid crystal in an isotropic phase, a nematic phase or a cholesteric phase is in a liquid state, and a ferroelectric liquid crystal in a smectic phase is in a paste form. In the present invention, the ferroelectric liquid crystal coated on the liquid crystal side substrate is instantaneously cooled to a smectic phase state, becomes a paste with a high viscosity, and does not easily spread. On the other hand, since the ferroelectric liquid crystal and the substrate are conventionally heated to a temperature at which the ferroelectric liquid crystal exhibits a cholesteric phase, a nematic phase or an isotropic phase, the ferroelectric liquid crystal coated on the substrate has a viscosity. It was low in liquid and easy to spread. Therefore, in the present invention, compared with the conventional case, the area where the ferroelectric liquid crystal comes into contact with air in the liquid crystal coating process can be reduced.
In general, the ferroelectric liquid crystal exhibits a smectic phase at room temperature. That is, in the present invention, the temperature of the liquid crystal side substrate can be set to room temperature. On the other hand, generally, the temperature at which the ferroelectric liquid crystal exhibits a cholesteric phase, a nematic phase or an isotropic phase is higher than room temperature.
Therefore, by setting the liquid crystal side substrate to a temperature at which the ferroelectric liquid crystal exhibits a smectic phase, it is possible to suppress the deterioration of the ferroelectric liquid crystal in the liquid crystal coating process.
Hereinafter, each process in the manufacturing method of the liquid crystal display element of this invention is demonstrated.

1. Liquid crystal coating step In the liquid crystal coating step of the present invention, the liquid crystal side substrate in which the first electrode layer and the first alignment film are laminated in this order on the first base material is set to a temperature at which the ferroelectric liquid crystal exhibits a smectic phase. Thereafter, the ferroelectric liquid crystal is applied on the first alignment film so that the ferroelectric liquid crystal applied on the first alignment film of the liquid crystal side substrate is in a smectic phase state.
Hereinafter, a ferroelectric liquid crystal, a liquid crystal side substrate, and a method for applying the ferroelectric liquid crystal will be described.

(1) Ferroelectric liquid crystal The ferroelectric liquid crystal used in the present invention is not particularly limited as long as it exhibits a chiral smectic C phase (SmC ^* ). As the phase series of the ferroelectric liquid crystal, for example, a phase change between a nematic (N) phase, a cholesteric (Ch) phase, a chiral smectic C (SmC ^* ) phase, and a nematic (N) phase-chiral smectic in the temperature lowering process. Phase change with C (SmC ^* ) phase, Nematic (N) phase-Smectic A (SmA) phase-Chiral smectic C (SmC ^* ) phase, Nematic (N) phase-Cholesteric (Ch) phase -Smectic A (SmA) phase-What changes phase with chiral smectic C (SmC ^* ) phase.

  Ferroelectric liquid crystals are bistable ones proposed by Clark and Lagerwol, which have two stable states when no voltage is applied (the upper part of FIG. 4), 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 a ferroelectric liquid crystal exhibiting monostability is used, 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. 5, the ferroelectric liquid crystal rotates along a cone ridge line in which the liquid crystal molecules 13 are inclined from the layer normal line z and have a bottom surface perpendicular to the layer normal line z. In such a cone, the tilt angle of the liquid crystal molecules 13 with respect to the layer normal z is referred to as a tilt angle θ. In this manner, the liquid crystal molecules 13 can operate on the cone between two states inclined by a tilt angle ± θ with respect to the layer normal z. Specifically, the expression of monostability refers to a state in which the liquid crystal molecules 13 are stabilized in any one state on the cone when no voltage is applied.

Among liquid crystal materials exhibiting monostability, for example, half-V shaped switching (hereinafter referred to as HV-shaped switching) in which liquid crystal molecules operate only when a positive or negative voltage is applied as shown in the lower left of FIG. .) 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, Zb and Zc are —COO—, —OCO—, —CH ₂ O—, —OCH ₂ —, —CH _{2, respectively.} CH ₂ —, —C≡C—, —CH═N—, —N═N—, —N (→ O) ═N—, —C (═O) S— or a single bond, and Rc is asymmetric. A linear or branched alkyl group which may have a carbon atom, an alkoxy group, an alkoxycarbonyl group, an alkanoyloxy group or an alkoxycarbonyloxy group, wherein Rd is a linear or branched group having an asymmetric carbon atom; And an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkanoyloxy group or an alkoxycarbonyloxy group, and Rc and Rd may be substituted with a halogen atom, a cyano group or a hydroxyl group. Can be used. As the optically active substance, the above compounds may be used alone or in combination of two or more.

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

  In the present invention, any compound may be mixed in the ferroelectric liquid crystal. As an arbitrary compound, what is provided with arbitrary functions according to the function calculated | required by a liquid crystal display element can be used. As a compound used suitably, a polymerizable monomer can be mentioned. This is because, by mixing a polymerizable monomer with the ferroelectric liquid crystal, the alignment of the ferroelectric liquid crystal can be so-called “polymer stabilization”, and excellent alignment stability can be 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, so that the intermolecular force and the polymer network at the alignment film interface can be strengthened. Thereby, the disorder of the alignment of the ferroelectric liquid crystal due to the temperature change can be suppressed.

  Among the polyfunctional monomers, bifunctional monomers having a polymerizable functional group at both ends of the molecule are preferably used. This is because by having a polymerizable functional group at both ends of the molecule, a polymer network having a wide interval between polymers can be formed, and a decrease in driving voltage due to a polymerized polymerizable monomer can be prevented.

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

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

  As an ultraviolet curable liquid crystal monomer used for this invention, the compound shown to following formula (1)-(3) can be mentioned, for example.

In the above formulas (1) and (2), 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 (3), 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 said polymerizable monomer may be used independently and may use 2 or more types together. For example, the ultraviolet curable liquid crystal monomer represented by the above formula may be used in combination with another ultraviolet curable resin monomer.

  The blending amount of the polymerizable monomer with respect to the ferroelectric liquid crystal is not particularly limited as long as the alignment stability of the ferroelectric liquid crystal is within a desired range, but the total mass of the ferroelectric liquid crystal and the polymerizable monomer is not limited. When the content is 100% by mass, the amount of the polymerizable monomer is preferably in the range of 0.5% by mass to 30% by mass, more preferably in the range of 1% by mass to 20% by mass, and still more preferably. It is in the range of 1% by mass to 10% by mass. This is because if the amount of the polymerizable monomer is larger than the above range, the drive voltage may increase or the response speed may decrease. Further, when the blending amount of the polymerizable monomer 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.

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

  In the present invention, the ferroelectric liquid crystal may or may not be heated before the ferroelectric liquid crystal is applied on the first alignment film. The temperature of the ferroelectric liquid crystal is appropriately selected according to the ferroelectric liquid crystal coating method described later.

For example, when a discharge method is used as a method for applying the ferroelectric liquid crystal, it is preferable that the ferroelectric liquid crystal is heated to a temperature at which the ferroelectric liquid crystal exhibits an isotropic phase or an N phase. That is, it is preferable to heat the ferroelectric liquid crystal to a temperature equal to or higher than the N phase. For example, a phase change and an isotropic phase -N phase -Ch phase-SmC ^* phase in the cooling process, or a ferroelectric liquid crystal phase change and an isotropic phase -N phase -Ch phase -SmA phase-SmC ^* phase When used, the ferroelectric liquid crystal is preferably heated to a temperature higher than the N-phase to Ch-phase transition temperature. Further, when a ferroelectric liquid crystal that changes in phase with the isotropic phase-N phase-SmC ^* phase is used in the temperature lowering process, the ferroelectric liquid crystal may be heated to a temperature higher than the N phase-SmC ^* phase transition temperature. preferable. Further, when a ferroelectric liquid crystal that changes in phase with the isotropic phase-N phase-SmA phase-SmC ^* phase is used in the temperature lowering process, the ferroelectric liquid crystal is heated to a temperature higher than the N-phase-SmA phase transition temperature. It is preferable. This is because if the ferroelectric liquid crystal is not heated, the viscosity of the ferroelectric liquid crystal is too high and the discharge nozzle is clogged, making it very difficult to stably discharge the ferroelectric liquid crystal.

  In the above case, it is particularly preferable to heat the ferroelectric liquid crystal to a temperature at which the ferroelectric liquid crystal exhibits an isotropic phase.

The specific temperature of the ferroelectric liquid crystal varies depending on the type of the ferroelectric liquid crystal and is appropriately selected. For example, an N phase-Ch phase transition temperature, an N phase-SmC ^* phase transition temperature or a temperature higher by about 10 ° C. to 20 ° C. than the N phase-SmA phase transition temperature, or near the N phase-isotropic phase transition temperature, or The temperature can be set to 0 ° C. to 10 ° C. higher than the N phase-isotropic phase transition temperature. Note that the upper limit of the temperature of the ferroelectric liquid crystal is a temperature at which the ferroelectric liquid crystal does not deteriorate.

  In addition, when a discharge method is used as a coating method of the ferroelectric liquid crystal, the ferroelectric liquid crystal is heated so that the viscosity of the ferroelectric liquid crystal is 30 mPa · s or less, particularly in the range of 10 mPa · s to 20 mPa · s. It is preferable to do. This is because if the viscosity of the ferroelectric liquid crystal is too high, the discharge nozzle becomes clogged and it becomes very difficult to stably discharge the ferroelectric liquid crystal.

  On the other hand, when a coating method or a printing method is used as a method for applying the ferroelectric liquid crystal, it is preferable that the ferroelectric liquid crystal is not heated. When using a coating method or a printing method, it is preferable to use a ferroelectric liquid crystal solution obtained by diluting a ferroelectric liquid crystal with a solvent in order to improve the coating property. For this reason, when the ferroelectric liquid crystal solution is heated, the solvent in the ferroelectric liquid crystal solution is volatilized and it becomes very difficult to apply the ferroelectric liquid crystal.

  In general, a ferroelectric liquid crystal exhibits a smectic phase near room temperature. In this case, it is preferable to set the ferroelectric liquid crystal to a temperature at which the ferroelectric liquid crystal exhibits a smectic phase.

(2) Liquid crystal side substrate The liquid crystal side substrate used in the present invention is obtained by laminating a first electrode layer and a first alignment film in this order on a first base material.
Hereinafter, each structure of the liquid crystal side substrate and the temperature of the liquid crystal side substrate will be described.

(I) 1st base material The 1st base material used for this invention will not be specifically limited if it is generally used as a base material of a liquid crystal display element, Even if it is transparent or opaque Good.
For example, when an active matrix type transmissive liquid crystal display element using TFTs is manufactured, the first substrate is transparent. Further, even when an active matrix type reflective liquid crystal display element using TFTs is manufactured and the liquid crystal side substrate is a common electrode substrate, the first base material is transparent. On the other hand, when a reflective liquid crystal display element of an active matrix type using TFT is manufactured, and the liquid crystal side substrate is a TFT substrate, the first base material is not required to be transparent.

  As a 1st base material, a glass plate, a plastic plate, etc. are mentioned preferably, for example.

(Ii) First electrode layer The first electrode layer used in the present invention is not particularly limited as long as it is generally used as an electrode of a liquid crystal display element. The first electrode layer may be transparent or opaque and is appropriately selected according to the image display surface. When the liquid crystal side substrate is an image display surface, the first electrode layer is preferably transparent and is preferably composed of a transparent conductor. Preferred examples of the transparent conductor material include indium oxide, tin oxide, indium tin oxide (ITO), and the like.

  Further, for example, when an active matrix type liquid crystal display element using TFT is manufactured, and the liquid crystal side substrate is a TFT substrate, the first electrode layer is a pixel electrode. On the other hand, when the liquid crystal side substrate is a common electrode substrate, the first electrode layer is a common electrode.

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

(Iii) First alignment film The first alignment film used in the present invention is not particularly limited as long as it can control the alignment of the ferroelectric liquid crystal. As the first 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 first alignment film may be a laminate of a rubbing alignment film, a photo alignment film, and the like and a reactive liquid crystal layer formed by fixing reactive liquid crystals. The reactive liquid crystal is aligned by a rubbing alignment film, a photo alignment film or the like. 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. In addition, reactive liquid crystals are relatively similar in structure to liquid crystals and have strong interaction with liquid crystals, so the alignment of liquid crystals can be controlled more effectively than when only rubbing alignment films or photo-alignment films are used. can do.
Hereinafter, the photo-alignment film and the reactive liquid crystal layer will be described.

(Photo-alignment film)
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 light that causes the photoexcitation 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.

a. 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 (4) 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 spacer units.

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

  Specific examples of such a dimerization reactive polymer include compounds represented by the following formulas (4-1) to (4-4).

  More specific examples of the dimerization reactive polymer include compounds represented by the following formulas (4-5) to (4-8).

  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.

b. 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, but the alignment control of the ferroelectric liquid crystal becomes easy. Two are preferable.

  The cis-trans isomerization reactive skeleton may have a substituent in order to further enhance the interaction with the liquid crystal molecules. The substituent is not particularly limited as long as it can enhance the interaction with the liquid crystal molecules and does not interfere with the orientation of the cis-trans isomerization reactive skeleton, and examples thereof include a carboxyl group and a sulfonic acid. A sodium group, a hydroxyl group, etc. are mentioned. These structures can be appropriately selected 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 larger, and is particularly suitable for controlling the alignment of ferroelectric liquid crystals Because it becomes. In this case, the aromatic hydrocarbon group or bonding group contained in the molecule is contained in the side chain together with the cis-trans isomerization reactive skeleton so that the interaction with the liquid crystal molecule is enhanced. It is preferable.

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

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

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

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

  Among such compounds having an azobenzene skeleton in the molecule, examples of the monomolecular compound include a compound represented by the following formula (5).

In the above formula, R ⁴¹ each independently represents a hydroxy group. R ⁴² represents _{^{- (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 (5-1) to (5-4).

  Moreover, as a polymerizable monomer which has the said azobenzene skeleton as a side chain, the compound represented by following formula (6) 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 (6-1) to (6-4).

  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.

c. 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.

(Reactive liquid crystal layer)
The reactive liquid crystal layer used in the present invention is formed on a rubbing alignment film, a photo alignment film or the like, and is formed by immobilizing reactive liquid crystals.

  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 (1) and (2) 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 (7) and (3).

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 (7), X is preferably alkyloxycarbonyl having 1 to 20 carbon atoms, methyl or chlorine, and especially alkyloxycarbonyl having 1 to 20 carbon atoms, particularly 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 (7) 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, 4-benzoyl-4'-methyldiphenyl. Sulfide, benzyl methyl ketal, dimethylaminomethyl benzoate, 2-n-butoxyethyl-4-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, 3,3′-dimethyl-4-methoxybenzophenone, methylobenzoyl formate, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 1- (4-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 more types of alcohols such as hexylene glycol, phenols, phenols such as phenol and parachlorophenol, and cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, and ethylene glycol monomethyl ether acetate can be used. 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.

(Iv) Spacer In the present invention, a spacer may be formed on the liquid crystal side substrate. This is because the formation of the spacer makes it possible to stably maintain the alignment of the ferroelectric liquid crystal that is vulnerable to external impact. As will be described later, when the spacer is formed on the counter substrate, the spacer need not be formed on the liquid crystal side substrate.

  Examples of the spacer include a wall spacer, a columnar spacer, and a spherical spacer. When the wall spacer 8 is formed on the liquid crystal side substrate 2a as illustrated in FIG. 7, the ferroelectric liquid crystal is confined in a minute linear space in the substrate bonding step, and the flowable space is restricted. Therefore, it is considered that the layer structure of the ferroelectric liquid crystal can be stably maintained. In this case, in order to control the alignment, it is preferable that the longitudinal direction of the wall spacer and the alignment processing direction of the first alignment film are orthogonal to each other. This is because the flow of liquid crystal molecules is induced substantially parallel to the longitudinal direction of the wall spacers, so that the orientation of the ferroelectric liquid crystal can be further improved.

Here, the longitudinal direction of the wall spacers and the alignment treatment direction of the first alignment film are orthogonal to each other because the angle between the longitudinal direction of the linear partition walls and the alignment treatment direction of the alignment film is 90 ° ± It means the range of 5 °. This angle is preferably in the range of 90 ° ± 1 °.
In addition, said angle can be measured by observing the alignment direction (alignment process direction of an alignment film) of a liquid crystal molecule and the longitudinal direction of a linear partition using a polarizing microscope.

  A plurality of spacers can be formed on the liquid crystal side substrate, and it is preferable to regularly form them at predetermined positions, and it is particularly preferable to form them substantially at regular intervals in parallel. This is because if the formation positions of the plurality of spacers are disordered, it may be difficult to adjust the position where the ferroelectric liquid crystal is applied.

  Although it does not specifically limit as a pitch of a spacer, For example, in the case of a wall-shaped spacer, it is preferable to set it as about 100 micrometers-3 mm, More preferably, it exists in the range of 200 micrometers-1.5 mm, More preferably, it is 300 micrometers- Within the range of 1.0 mm. This is because if the pitch of the wall spacer is narrower than the above range, the display quality may be deteriorated due to poor alignment of the ferroelectric liquid crystal near the wall spacer. On the other hand, if the pitch of the wall spacers is wider than the above range, it may vary depending on the size of the liquid crystal display element, but the desired impact resistance cannot be obtained, or it becomes difficult to keep the thickness of the liquid crystal layer constant. Because there is a case to do. The pitch of the wall spacers refers to the distance from the center part of the adjacent wall spacers to the center part.

  Further, the size of the spacer is not particularly limited. For example, the width of the wall spacer, the diameter of the bottom surface of the columnar spacer, and the diameter of the spherical spacer are preferably about 1 μm to 20 μm, and more preferably. Is in the range of 2 μm to 10 μm, more preferably in the range of 5 μm to 10 μm. If it is larger than the above range, the spacer is also provided in the pixel region, and the effective pixel area becomes narrow, and a good image display may not be obtained. Further, if it is smaller than the above range, it may be difficult to form the spacer.

  Furthermore, the height of the spacer is usually approximately the same as the thickness of the liquid crystal layer.

  The pitch, width, diameter, height, and the like of the spacer can be measured by observing the cross section of the linear partition using a scanning electron microscope (SEM).

  The formation position of the spacer is not particularly limited, but it is preferable to form the spacer while avoiding the pixel region. This is because it is preferable to form the spacer in a region that does not affect the image display because the alignment of the ferroelectric liquid crystal tends to occur near the spacer. For example, it is preferable to form a spacer in the opening of the first electrode layer formed in a stripe shape or a matrix shape.

  As for the formation position of the spacer, a spacer (wall spacer 8) may be formed on the first electrode layer 6a as illustrated in FIG. 8, and the first base as illustrated in FIG. 9A. A spacer (wall spacer 8) may be formed on the material 5a. Moreover, when forming a spacer on a 1st base material, you may integrally form a spacer (wall-shaped spacer 8) and base part 8 'so that it may illustrate in FIG.9 (b).

  The number of spacers is appropriately selected depending on the size of the liquid crystal display element.

  As a material for forming such a spacer, a material generally used for a spacer of a liquid crystal display element can be used. For example, a resin can be mentioned, and among these, a photosensitive resin is preferably used. This is because the photosensitive resin is easy to pattern. The photosensitive resin used in the present invention is not particularly limited as long as it is generally used for a spacer of a liquid crystal display element.

  The method for forming the spacer is not particularly limited as long as the spacer can be formed at a predetermined position, and a general patterning method can be applied. For example, a photolithography method, an inkjet method, a screen printing method, and the like can be given.

(V) Colored layer In the present invention, a colored layer may be formed on the liquid crystal side substrate. When a colored layer is formed, a color filter type liquid crystal display element can be obtained. As will be described later, when the colored layer is formed on the counter substrate, the colored layer is not formed on the liquid crystal side substrate.

  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.

(Vi) Temperature of Liquid Crystal Side Substrate In the present invention, the liquid crystal side substrate is set to a temperature at which the ferroelectric liquid crystal exhibits a smectic phase. That is, the liquid crystal side substrate is set to a temperature at which the ferroelectric liquid crystal exhibits the SmC ^* phase or the SmA phase. For example, when a ferroelectric liquid crystal that changes in phase with the isotropic phase-N phase-Ch phase-SmC ^* phase in the temperature lowering process is used, the liquid crystal side substrate is set to a temperature lower than the Ch phase-SmC ^* phase transition temperature. In the case of using a ferroelectric liquid crystal that changes phase with the isotropic phase-N phase-SmC ^* phase in the temperature lowering process, the liquid crystal side substrate is set to a temperature lower than the N phase-SmC ^* phase transition temperature. Further, when a ferroelectric liquid crystal that changes in phase with the isotropic phase-N phase-SmA phase-SmC ^* phase in the temperature lowering process is used, the liquid crystal side substrate is set to a temperature lower than the N phase-SmA phase transition temperature. In addition, when a ferroelectric liquid crystal that changes in phase with the isotropic phase-N phase-Ch phase-SmA phase-SmC ^* phase is used in the temperature lowering process, the liquid crystal side substrate is set to a temperature lower than the Ch phase-SmA phase transition temperature. To do.

  The specific temperature differs depending on the type of ferroelectric liquid crystal and is appropriately selected. Usually, the liquid crystal side substrate is set to room temperature (about 15 ° C. to 30 ° C.).

(3) Ferroelectric liquid crystal coating method In the present invention, as a ferroelectric liquid crystal coating method, a ferroelectric liquid crystal can be applied in a predetermined amount capable of being sealed on the first alignment film of the liquid crystal side substrate. The method is not particularly limited. Among them, a method in which the ferroelectric liquid crystal can be applied so that the ferroelectric liquid crystal hardly flows is preferable. When the ferroelectric liquid crystal flows in an isotropic phase state on the first alignment film, if the flow distance of the ferroelectric liquid crystal is too long, the orientation may be disturbed at the interface where the flowed ferroelectric liquid crystal contacts. Because.

  Usually, the ferroelectric liquid crystal is applied in a pattern. Among them, it is preferable to apply the ferroelectric liquid crystal in a pattern in which the applied ferroelectric liquid crystal hardly flows, and it is particularly preferable to apply the ferroelectric liquid crystal in a stripe shape. By applying the ferroelectric liquid crystal in a stripe shape, the distance that the ferroelectric liquid crystal flows can be shortened, and the alignment disorder generated when the ferroelectric liquid crystal flows can be suppressed. The reason is not clear, but when the ferroelectric liquid crystal is applied continuously in the form of stripes compared to the case where the ferroelectric liquid crystal is applied intermittently in the form of dots, the flowing ferroelectric liquid crystal is in contact with the liquid crystal. The alignment disorder at the interface is difficult to occur.

  In general, a ferroelectric liquid crystal having a phase sequence via an SmA phase as illustrated in the lower part of FIG. 6 has a smectic layer in order to compensate for the volume change because the layer spacing of the smectic layer is reduced during the phase change process. A domain having a bent chevron structure and different major axis directions of the liquid crystal molecules is formed depending on the bending direction, and alignment defects called zigzag defects and hairpin defects are likely to occur at the interface. In general, a ferroelectric liquid crystal having a phase series that does not pass through the SmA phase as exemplified in the upper part of FIG. 6 is likely to generate two regions (double domains) having different layer normal directions. As described above, by applying the ferroelectric liquid crystal in a stripe shape, alignment disorder due to the flow of the ferroelectric liquid crystal can be suppressed, and the occurrence of alignment defects as described above can be suppressed.

  Examples of such a coating method include a discharge method such as an ink jet method and a dispenser method, a coating method such as a bar coating method and a slot die coating method, a printing method such as a flexographic printing method, a gravure printing method, an offset printing method, and a screen printing method. Law. Of these, the discharge method and the screen printing method are preferable. This is because the ejection method and the screen printing method can effectively suppress the alignment disorder that occurs when the ferroelectric liquid crystal flows.

  Further, a discharge method is preferable, and an inkjet method is particularly preferable among the discharge methods. If the inkjet method is used, the ferroelectric liquid crystal can be applied in a continuous manner, so that the ferroelectric liquid crystal can be applied so as to shorten the flow distance, and at the contact interface of the flowed ferroelectric liquid crystal. This is because the occurrence of alignment disorder can be prevented.

  The amount of droplets of the ferroelectric liquid crystal to be discharged is preferably in the range of 1 pl to 1000 pl per discharge, more preferably in the range of 2 pl to 200 pl, and still more preferably in the range of 10 pl to 100 pl. . When the appropriate amount of the liquid is larger than the above range, the distance that the ferroelectric liquid crystal flows becomes long and the area where the liquid crystal spreads out becomes large. Also, if the appropriate amount of liquid is less than the above range, the time required for applying the ferroelectric liquid crystal becomes very long. Conventionally, when discharging ferroelectric liquid crystal on a substrate, the amount of droplets of ferroelectric liquid crystal to be discharged is about 10 ng per discharge, so the above range is a relatively small amount of droplets. It can be seen that it is.

  Further, the position where the ferroelectric liquid crystal is applied is not particularly limited as long as the ferroelectric liquid crystal is applied in a predetermined amount capable of being sealed.

  As described above, when the wall spacer is formed on the liquid crystal side substrate and the longitudinal direction of the wall spacer and the alignment processing direction of the first alignment film are orthogonal to each other, as illustrated in FIG. Further, it is preferable to apply the ferroelectric liquid crystal 3 along the wall-like spacer 8. By applying the ferroelectric liquid crystal in this way, the ferroelectric liquid crystal can easily flow along the alignment treatment direction of the first alignment film, and the occurrence of alignment defects and the like can be effectively suppressed. is there.

2. Inspection Step The inspection step in the present invention is a step for inspecting the presence or absence of a coating defect of the ferroelectric liquid crystal. In this inspection step, as illustrated in FIG. 1, when the ferroelectric liquid crystal 3 is not applied to the region to be applied, it is detected as a coating defect.

  Examples of the coating defect inspection method include a method using a CCD element and a method of visually inspecting an enlarged image.

  In the present invention, if a coating defect is not detected in the inspection process, the process proceeds to the substrate bonding process as it is. If a coating defect is detected in the inspection process, the process proceeds to the correction process, and the correction process. It progresses to a board | substrate bonding process later.

3. Correction Step The correction step in the present invention is a step of applying a ferroelectric liquid crystal to the defective portion on the first alignment film by a discharge method when a coating defect is detected in the inspection step.

  A method of applying the ferroelectric liquid crystal to the defective portion on the first alignment film is a discharge method, and is not particularly limited as long as the ferroelectric liquid crystal can be applied only to the defective portion. . Examples of such a coating method include an inkjet method and a dispenser method.

4). Substrate bonding step The substrate bonding step in the present invention includes a liquid crystal side substrate coated with a ferroelectric liquid crystal, and a counter substrate in which a second electrode layer and a second alignment film are laminated in this order on a second base material. Is a step of bonding.

In order to bond the liquid crystal side substrate and the counter substrate together, first, a sealing agent is applied on at least one of the liquid crystal side substrate and the counter substrate so as to surround the liquid crystal sealing region, and then the liquid crystal side substrate and the counter substrate are sealed. And finally the sealant is cured.
Hereinafter, the sealing agent, the counter substrate, and the method for bonding the liquid crystal side substrate and the counter substrate will be described.

(1) Sealant In the present invention, a sealant is applied on at least one of the liquid crystal side substrate and the counter substrate so as to surround the liquid crystal sealing region. That is, the sealing agent may be applied on the liquid crystal side substrate, may be applied on the counter substrate, or may be applied on both the liquid crystal side substrate and the counter substrate.
As will be described later, when the frame-shaped partition is formed on the liquid crystal side substrate or the counter substrate, a sealing agent is applied so as to surround the outer periphery of the frame-shaped partition. For example, as shown in FIG. 7, when the frame-shaped partition wall 9 is formed on the liquid crystal side substrate, the sealing agent 4 is applied so as to surround the outer periphery of the frame-shaped partition wall 9.

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

  As the position for applying the sealing agent, it is possible to apply the sealing agent continuously so as to surround the liquid crystal sealing region, and to bond the liquid crystal side substrate and the counter substrate so that the ferroelectric liquid crystal does not leak. For example, there is no particular limitation. When apply | coating a sealing compound on a liquid crystal side board | substrate, you may apply | coat to a 1st base material and may apply | coat to a 1st orientation film. Moreover, when apply | coating a sealing compound on a counter substrate, you may apply | coat on a 2nd base material and may apply | coat on a 2nd alignment film. Usually, a sealing agent is applied to the peripheral edge of the liquid crystal side substrate or the counter substrate. From the viewpoint of adhesion, it is preferable to apply a sealing agent on the first substrate or the second substrate. In this case, the first alignment film or the second alignment film is formed in a pattern so that the first alignment film or the second alignment film is not formed on the periphery of the first substrate or the second substrate.

  As a sealing agent, what is generally used for a liquid crystal display element can be used. For example, resin is mentioned, and both thermosetting resin and ultraviolet curable resin can be used. Among them, it is preferable to use a sealant that does not contaminate the ferroelectric liquid crystal.

(2) Counter substrate The counter substrate used in the present invention is obtained by laminating a second electrode layer and a second alignment film in this order on a second base material.
The second base material, the second electrode layer, and the second alignment film are the same as the first base material, the first electrode layer, and the first alignment film of the liquid crystal side substrate, respectively. Omitted.

  In the present invention, it is preferable that the constituent materials of the first alignment film and the second alignment film have different compositions with the ferroelectric liquid crystal interposed therebetween. Thereby, when a ferroelectric liquid crystal having no SmA phase is used, the monodomain alignment of the ferroelectric liquid crystal can be obtained without causing alignment defects such as double domains.

  In order to change the composition of the constituent materials of the first alignment film and the second alignment film, for example, one may be a photo-alignment film and the other may be a rubbing alignment film. Moreover, both can be made into a rubbing alignment film, and the composition of the constituent material of a rubbing alignment film can be made different, or both can be made into a photo-alignment film and the composition of the constituent material of a photo-alignment film can be made different.

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

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

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

  Furthermore, one is a single layer such as a photo-alignment film or a rubbing alignment film, and the other is a laminate of a photo-alignment film, a rubbing alignment film, or the like and a reactive liquid crystal layer. The composition of the constituent materials of the film can be different.

  When the first alignment film and the second alignment film are formed by laminating an alignment film, a rubbing alignment film, and the like and a reactive liquid crystal layer, the reactive liquid crystal layer can be configured by variously selecting the above-described polymerizable liquid crystal material. The composition of the materials can be different.

In the present invention, a spacer may be formed on the counter substrate. By forming the spacer, a liquid crystal display element having high impact resistance can be obtained. As described above, when the spacer is formed on the liquid crystal side substrate, the spacer may not be formed on the counter substrate.
Since the spacer is the same as the spacer of the liquid crystal side substrate, the description thereof is omitted here.

(3) Method of bonding the liquid crystal side substrate and the counter substrate The liquid crystal side substrate and the counter substrate have a predetermined arrangement of the liquid crystal sealing region and the sealant, and the first alignment film of the liquid crystal side substrate and the second of the counter substrate The alignment films are opposed so that the alignment treatment directions are substantially parallel to each other.

  When the liquid crystal side substrate and the counter substrate are opposed to each other, it is preferable to heat the liquid crystal side substrate and the counter substrate to a temperature at which the ferroelectric liquid crystal exhibits a nematic phase or an isotropic phase, and in particular, the ferroelectric liquid crystal is isotropic. It is more preferred to heat to a temperature that exhibits a phase. Specific temperatures of the liquid crystal side substrate and the counter substrate vary depending on the type of the ferroelectric liquid crystal and are appropriately selected. For example, in the vicinity of the N phase-isotropic phase transition temperature, a temperature higher by about 0 ° C. to 20 ° C. than the N phase-isotropic phase transition temperature, or 5 ° C.-10 ° C. than the N phase-isotropic phase transition temperature. The temperature can be set to a relatively high temperature. The upper limit of the temperature of the liquid crystal side substrate and the counter substrate is set to a temperature at which the ferroelectric liquid crystal does not deteriorate.

  In addition, it is preferable to heat the liquid crystal side substrate and the counter substrate so that the viscosity of the ferroelectric liquid crystal is 30 mPa · s or less, particularly in the range of 10 mPa · s to 20 mPa · s. This is because if the viscosity of the ferroelectric liquid crystal is too high, the ferroelectric liquid crystal hardly flows on the first alignment film.

  When a ferroelectric liquid crystal solution obtained by diluting a ferroelectric liquid crystal with a solvent is applied on the first alignment film by a coating method or a printing method, the solvent can be removed when the liquid crystal side substrate is heated. .

  Further, when the liquid crystal side substrate and the counter substrate are opposed to each other, it is preferable that the chamber is evacuated to sufficiently reduce the pressure between the liquid crystal side substrate and the counter substrate. Thereby, it can prevent that a space | gap remains in a liquid crystal cell.

  After the liquid crystal side substrate and the counter substrate are made to face each other, the liquid crystal side substrate and the counter substrate are superposed under reduced pressure, and a certain pressure is applied so that the cell gap becomes uniform. Then, by returning the inside of the chamber to normal pressure, further pressure is applied between the liquid crystal side substrate and the counter substrate. Thereby, a cell gap can be made more uniform. In this way, the liquid crystal side substrate and the counter substrate are pressure-bonded via the sealant.

  Next, the sealant is cured, and the liquid crystal side substrate and the counter substrate are bonded together. The curing method of the sealing agent varies depending on the type of the sealing agent used, and examples thereof include a method of irradiating with ultraviolet rays and a method of heating. At this time, the sealing agent is usually cured while maintaining the pressure when the liquid crystal side substrate and the counter substrate are overlaid.

  The thickness of the liquid crystal layer composed of the ferroelectric liquid crystal 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 2 μm. Within the range of 0.0 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.

5). Frame-shaped partition wall forming step In the present invention, a frame-shaped partition wall forming step of forming a frame-shaped partition wall inside the sealing agent may be performed on the liquid crystal side substrate or the counter substrate so as to surround the liquid crystal sealing region. For example, as shown in FIG. 7 and FIG. 8A, a frame-shaped partition wall 9 can be formed on the liquid crystal side substrate 2 a, and the sealant 4 can be applied around the frame-shaped partition wall 9. FIG. 8A is a cross-sectional view taken along the line CC of FIG. As illustrated in FIGS. 8B and 8C, the ferroelectric liquid crystal 3 applied on the liquid crystal side substrate 2a flows between the liquid crystal side substrate 2a and the counter substrate 2b in the substrate bonding step. At this time, by forming the frame-shaped partition wall 9 inside the sealing agent 4, it is possible to avoid the ferroelectric liquid crystal 3 and the uncured sealing agent 4 from being in direct contact with each other. As a result, it is possible to prevent impurities in the uncured sealant, volatile substances generated from the sealant when the sealant is cured, and the like from being mixed into the ferroelectric liquid crystal. Therefore, it is possible to avoid deterioration of the characteristics of the ferroelectric liquid crystal due to the mixing of impurities or the like.

  The position where the frame-shaped partition is formed is not particularly limited as long as the frame-shaped partition is continuously formed so as to surround the liquid crystal sealing region inside the sealant. When the frame-like partition is formed on the liquid crystal side substrate, the frame-like partition 9 may be formed on the first electrode layer 6a as illustrated in FIG. 8, and the first as illustrated in FIG. 9A. A frame-shaped partition wall 9 may be formed on the substrate 5a. Moreover, when forming a frame-shaped partition on a 1st base material, you may integrally form the frame-shaped partition 9 and base part 8 'so that it may illustrate in FIG.9 (b). On the other hand, although not shown, when the frame-shaped partition is formed on the counter substrate, the frame-shaped partition may be formed on the second electrode layer, or the frame-shaped partition may be formed on the second substrate. Moreover, when forming a frame-shaped partition on a 2nd base material, you may form a frame-shaped partition and a base part integrally. Usually, a frame-shaped partition is formed at the peripheral edge of the first alignment film or the second alignment film.

  The width of the frame-shaped partition wall is not particularly limited as long as it can prevent contact between the ferroelectric liquid crystal and the uncured sealant. Specifically, the width of the frame-shaped partition wall is preferably about 10 μm to 3 mm, more preferably in the range of 10 μm to 1 mm, and still more preferably in the range of 10 μm to 500 μm. This is because if the width of the frame-shaped partition wall is wider than the above range, the frame-shaped partition wall is also provided in the pixel region, and the effective pixel area becomes narrow and a good image display may not be obtained. Moreover, it is because formation of a frame-shaped partition may become difficult when the width of a frame-shaped partition is narrower than the said range.

  In addition, the height of the frame-shaped partition walls is usually approximately the same as the thickness of the liquid crystal layer. Thereby, it can prevent effectively that a ferroelectric liquid crystal and an uncured sealing agent contact.

  In addition, the width | variety and height of the said frame-shaped partition can be measured by observing the cross section of a frame-shaped partition using a scanning electron microscope (SEM).

  As a material for forming such a frame-shaped partition wall, a material generally used for a partition wall of a liquid crystal display element can be used. Preferably, the same material as that for forming the spacer is used. This is because the frame-shaped partition wall and the spacer can be formed simultaneously.

  The method for forming the frame-shaped partition wall is not particularly limited as long as it can form the frame-shaped partition wall at a predetermined position, and a general patterning method can be applied. For example, a photolithography method, an inkjet method, a screen printing method, and the like can be given.

  The formation of the frame-shaped partition wall is usually performed simultaneously with the formation of the spacer. This is because the number of patterning steps can be reduced. The frame-shaped partition walls and the spacers may be formed on separate substrates, but are preferably formed on the same substrate from the viewpoint of patterning.

6). Liquid crystal display element In the present invention, for example, an active matrix type liquid crystal display element using TFTs can be manufactured. In the active matrix system using TFTs, a target pixel can be reliably turned on and off, so that high quality image display is possible.

FIG. 10 is a schematic perspective view showing an example of an active matrix liquid crystal display element using TFTs. The liquid crystal display element 20 illustrated in FIG. 10 includes a TFT substrate (counter substrate 2b) in which TFTs 21 are arranged in a matrix on the second substrate 5b, and a common electrode (first electrode layer 6a) on the first substrate 5a. ) Formed on the common electrode substrate (liquid crystal side substrate 2a). On the TFT substrate (counter substrate 2b), a pixel electrode (second electrode layer 6b), a gate electrode 22x, and a source electrode 22y are formed. In such a liquid crystal display element 20, the gate electrode 22x and the source electrode 22y are arranged vertically and horizontally, and the TFT 21 is operated by applying a signal to the gate electrode 22x and the source electrode 22y, thereby driving the ferroelectric liquid crystal. be able to. A portion where the gate electrode 22x and the source electrode 22y intersect is insulated by an insulating layer (not shown), and the signal of the gate electrode 22x and the signal of the source electrode 22y can operate independently. A portion surrounded by the gate electrode 22x and the source electrode 22y is a pixel which is a minimum unit for driving the liquid crystal display element, and at least one TFT 21 and a pixel electrode (second electrode layer 6b) are formed in each pixel. Has been. In the liquid crystal display element 20, the TFT 21 of each pixel can be operated by sequentially applying a signal voltage to the gate electrode 22x and the source electrode 22y.
In FIG. 10, the first alignment film, the second alignment film, and the ferroelectric liquid crystal are omitted.

  In the example shown in FIG. 10, the liquid crystal side substrate is a common electrode substrate and the counter substrate is a TFT substrate. However, the present invention is not limited to this, and the liquid crystal side substrate may be a common electrode substrate. It may be a TFT substrate. Among them, the liquid crystal side substrate is preferably a common electrode substrate. Since the TFT substrate includes a TFT having a semiconductor layer, a gate electrode, a source electrode, a drain electrode, an insulating layer, and the like, the manufacturing cost of the common electrode substrate is lower between the TFT substrate and the common electrode substrate. For this reason, if the liquid crystal side substrate is a common electrode substrate, even if there is a coating defect of the ferroelectric liquid crystal and it cannot be corrected, loss cost can be reduced.

  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.
(Preparation of substrate 1 for liquid crystal display element)
The glass substrate on which the ITO electrode was formed was washed thoroughly, a transparent resist (trade name: NN780, manufactured by JSR) was spin coated on the glass substrate, dried under reduced pressure, and prebaked at 90 ° C. for 3 minutes. Subsequently, it exposed to a mask with 100 mJ / cm ² ultraviolet rays, developed with an inorganic alkali solution, and post-baked at 230 ° C. for 30 minutes. Thereby, a columnar spacer having a height of 1.5 μm was formed.
Next, a 2% by mass cyclopentanone solution of a photodimerization reaction type photo-alignment film material (trade name: ROP-103, manufactured by Rorlic Technology Co., Ltd.) is spin-coated on the substrate on which the columnar spacers are formed, and the temperature is 130 ° C. And dried for 10 minutes, and then irradiated with about 100 mJ / cm ^{2 of} linearly polarized ultraviolet rays for alignment treatment.

(Preparation of substrate 2 for liquid crystal display element)
The glass substrate on which the ITO electrode is formed is thoroughly washed, and a 2% by mass cyclopentanone solution of a photodimerization reaction type photo-alignment film material (trade name: ROP-102, manufactured by Roric Technology) is applied on the glass substrate. After spin-coating and drying at 130 ° C. for 10 minutes, alignment treatment was performed by irradiating with linear ultraviolet polarized light of about 100 mJ / cm ² .

[Example 1]
The liquid crystal display element substrate 1 was placed on a uniaxial stage set at room temperature (23 ° C.). While moving the uniaxial stage on which this liquid crystal display element substrate 1 is placed at a speed of about 60 mm / second, using an inkjet apparatus (SE-128 made by Dymatic) at a frequency of about 3,600 Hz, Ferroelectric liquid crystal (trade name: R2301, manufactured by AZ Electronic Materials) was dropped for 1 second, and the ferroelectric liquid crystal was applied in stripes at 1 mm intervals. At this time, in the inkjet apparatus, an inkjet head having 64 ejection holes was heated to about 100 ° C. The ferroelectric liquid crystal is considered to be in an isotropic phase state when dropped, but is cooled to room temperature at the moment of landing on the substrate and is considered to be in a chiral smectic phase state. Actually, the ferroelectric liquid crystal dropped on the substrate was white, and a white line-like pattern was obtained. Moreover, when this board | substrate was test | inspected with the inspection apparatus which has a CCD sensor, it confirmed that there was no coating defect.

  Next, a sealing agent was applied on the liquid crystal display element substrate 1 on which the ferroelectric liquid crystal was applied. Next, the hot plate placed in the vacuum chamber was heated to 110 ° C., and the liquid crystal display element substrate 1 coated with a sealant was placed on the hot plate. Next, the liquid crystal display element substrate 2 was adsorbed by an adsorption plate, and the liquid crystal display element substrate 1 and the liquid crystal display element substrate 2 were opposed to each other so that the respective alignment treatment directions were parallel. Then, the substrates were brought into close contact with each other in a state where evacuation was performed so that the inside of the vacuum chamber became 10 Torr, and after applying a certain pressure, the inside of the vacuum chamber was returned to normal pressure. Thereafter, the ferroelectric liquid crystal was gradually cooled to room temperature to produce a liquid crystal display element.

  When the produced liquid crystal display element was arranged between the polarizing plates arranged in crossed Nicols and observed, it was confirmed that the ferroelectric liquid crystal was uniformly oriented.

[Example 2]
The liquid crystal display element substrate 1 was placed on a uniaxial stage set at room temperature (23 ° C.). Next, a ferroelectric liquid crystal is dropped and stripes are formed in the same manner as in Example 1 except that only one discharge hole among the 64 discharge holes of the inkjet head in the inkjet apparatus is paused for 0.1 second. Ferroelectric liquid crystal was applied in the shape. When this board | substrate was test | inspected with the test | inspection apparatus which has a CCD sensor, it detected that the ferroelectric liquid crystal was not apply | coated by the length of about 6 mm to the part which stopped discharge. Next, the ferroelectric liquid crystal was applied in a line shape to the portion where the ferroelectric liquid crystal was not applied, and correction was performed using an inkjet head in which only one ejection hole was driven.

Next, a sealing agent is applied on the liquid crystal display element substrate 1 coated with ferroelectric liquid crystal, and the liquid crystal display element substrate 1 and the liquid crystal display element substrate 2 are bonded in the same manner as in Example 1. A liquid crystal display element was produced.
When the produced liquid crystal display element was arranged between the polarizing plates arranged in crossed Nicols and observed, it was confirmed that the ferroelectric liquid crystal was uniformly oriented.

[Comparative example]
A hot plate was placed on a uniaxial stage, the hot plate was heated to 100 ° C., and the liquid crystal display element substrate 1 was placed on the hot plate. Next, a ferroelectric liquid crystal is dropped and stripes are formed in the same manner as in Example 1 except that only one discharge hole among the 64 discharge holes of the inkjet head in the inkjet apparatus is paused for 0.1 second. Ferroelectric liquid crystal was applied in the shape.
The ferroelectric liquid crystal applied on the substrate wets and spreads. At that time, the ferroelectric liquid crystal was transparent. For this reason, even if an inspection apparatus having a CCD sensor is used, a portion where the ferroelectric liquid crystal is not applied cannot be detected.

It is a figure which shows an example of the liquid-crystal application | coating process and test | inspection process in the manufacturing method of the liquid crystal display element of this invention. It is process drawing which shows an example of the manufacturing method of the liquid crystal display element of this invention. It is a figure which shows an example of the correction process in the manufacturing method of the liquid crystal display element of this invention. 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. It is the figure which showed the difference in orientation by the difference in the phase sequence which a ferroelectric liquid crystal has. It is a figure which shows the other example of the liquid-crystal application | coating process in the manufacturing method of the liquid crystal display element of this invention. It is process drawing which shows the other example of the manufacturing method of the liquid crystal display element of this invention. It is a schematic sectional drawing which shows an example of the liquid crystal side substrate used for this invention. It is a schematic perspective view which shows an example of the liquid crystal display element obtained by the manufacturing method of the liquid crystal display element of this invention.

Explanation of symbols

2a ... Liquid crystal side substrate 2b ... Counter substrate 3 ... Ferroelectric liquid crystal 4 ... Sealing agent 5a ... First base material 5b ... Second base material 6a ... First electrode layer 6b ... Second electrode layer 7a ... First alignment film 7b ... second alignment film 11 ... defective part

Claims (4)

After setting the liquid crystal side substrate in which the first electrode layer and the first alignment film are laminated in this order on the first base material to a temperature at which the ferroelectric liquid crystal exhibits a smectic phase, the first alignment film of the liquid crystal side substrate A liquid crystal coating step of coating a ferroelectric liquid crystal on the first alignment film so that the ferroelectric liquid crystal coated thereon is in a smectic phase state;
An inspection process for inspecting the presence or absence of coating defects of the ferroelectric liquid crystal;
When a coating defect is detected in the inspection step, a correction step of applying the ferroelectric liquid crystal to the defective portion on the first alignment film by a discharge method;
A liquid crystal side substrate coated with the ferroelectric liquid crystal, and a substrate bonding step of bonding a counter substrate in which a second electrode layer and a second alignment film are laminated in this order on a second base material. A method for producing a liquid crystal display element. In the liquid crystal application step, before applying the ferroelectric liquid crystal on the first alignment film, the ferroelectric liquid crystal is heated to a temperature showing a nematic phase or an isotropic phase,
The method for manufacturing a liquid crystal display element according to claim 1, wherein the ferroelectric liquid crystal application method is a discharge method.   The method for manufacturing a liquid crystal display element according to claim 1, wherein the application method of the ferroelectric liquid crystal is a screen printing method.   The method for manufacturing a liquid crystal display element according to claim 1, wherein the liquid crystal side substrate is a common electrode substrate, and the counter substrate is a thin film transistor (TFT) substrate.

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