JP6507608B2 - Liquid crystal display device - Google Patents

Description

  The present invention relates to a sheath-core type composite fiber containing a liquid crystal composition, and a liquid crystal display device having a composite fiber assembly in which the composite fibers are uniaxially aligned.

  Liquid crystal display devices have advantages such as thinness, light weight, low power consumption, low power drive, and so are widely used as display media for watches, calculators, cellular phones, personal computers, televisions, and the like.

  In a general liquid crystal display device, a means for controlling the alignment of liquid crystal molecules is required, and a means for forming an alignment film is generally used. For example, a method of controlling the alignment of liquid crystal molecules in a direction parallel to the substrate by an alignment film subjected to rubbing treatment, or introducing a hydrophobic structure such as an alkyl group or a fluorine-containing group into the alignment film A method of controlling the alignment of liquid crystal molecules in the vertical direction is used.

  There are various types of liquid crystal display elements, but as elements capable of achieving a wide viewing angle, elements of an IPS (In-Plane Switching) system that switches liquid crystal molecules in parallel with a substrate surface, FFS (Fringe) A field switching method is known (see Patent Documents 1 and 2). Further, as an element capable of achieving high-speed response, an element of the ULH (Uniform Lying Helix) system using the flexoelectric effect particularly found in a cholesteric liquid crystal is known (see Patent Documents 3 and 4).

Patent No. 2940354 JP 2002-82357 A Unexamined-Japanese-Patent No. 2004-133464 Japanese Patent Application Publication No. 2009-540023

  In recent years, flexible liquid crystal display devices using plastic films and the like as substrates have attracted attention. Such a flexible liquid crystal display element is thinner and lighter than a liquid crystal display element using a conventional glass substrate, and can be used as a display element which can be stored by being rounded and can be carried easily. However, since the high temperature process is required when forming the alignment film, there is a problem that the use of the flexible substrate having low heat resistance is limited. Therefore, a method for controlling the alignment of liquid crystal molecules without forming an alignment film is required.

  In addition, when the flexible liquid crystal display element is bent, the thickness of the liquid crystal portion through which light is transmitted changes, so that the brightness and color tone change before and after the bending. There is a need for an element that solves such problems.

  In addition, in manufacturing a liquid crystal display device of the ULH system, it is necessary to arrange the helical axis of the cholesteric phase in parallel with the substrate and in a specific direction, but it is difficult to align the helical axes in a certain direction. No plan has been obtained. For this reason, it is practically difficult to increase the size (larger screen size) of the liquid crystal display device of the ULH system, and a technique capable of achieving the size increase is required.

  The present invention provides a liquid crystal display device, and further a flexible liquid crystal display device, which can be easily manufactured and can be made larger.

The present invention has the following configuration.
[1] A composite fiber aggregate formed by uniaxially aligning at least one substrate and a liquid crystal-containing composite fiber which is a composite fiber of sheath core type disposed on the substrate and having a liquid crystal composition as a core component, and the substrate And an electrode for applying an electric field to the composite fiber assembly based on an external signal, wherein a sheath component forming the outer shell of the liquid crystal-containing composite fiber is a sheath component-forming material A liquid crystal display device, comprising: the sheath component-forming material and the liquid crystal composition substantially separated.
[2] The liquid crystal display element according to [1], wherein the liquid crystal-containing composite fiber is formed by discharging the sheath component forming material and the liquid crystal composition from different nozzles.
[3] The liquid crystal display element according to [1], wherein a voltage applied to drive the liquid crystal composition is 50 V or less.
[4] The liquid crystal display element according to [1], wherein the composite fiber assembly includes a binder filled between the liquid crystal inclusion composite fibers.
[5] The liquid crystal display element according to any one of the above [1] to [4], wherein the liquid crystal composition contains a halogen-based liquid crystal compound.
[6] The liquid crystal display device according to any one of the above [1] to [5], wherein the liquid crystal composition exhibits a nematic phase or a chiral nematic phase in which the helical pitch is longer than 10 μm.
[7] Any one of the above [1] to [6], wherein the electrode is a lateral electric field drive electrode capable of applying an electric field in a direction substantially parallel to the substrate with respect to the composite fiber assembly. The liquid crystal display element as described in a term.
[8] The liquid crystal display element according to any one of the above [5] to [7], wherein the dielectric anisotropy of the liquid crystal composition is +2 or more or −2 or less.
[9] The liquid crystal composition described above exhibits a cholesteric phase, and the electrode is a longitudinal electric field drive electrode capable of applying an electric field in a direction substantially perpendicular to the substrate with respect to the composite fiber aggregate. The liquid crystal display element of any one of 1]-[5].
[10] The liquid crystal display device according to [9], wherein a helical axis of the cholesteric phase is substantially parallel to a fiber axis.
[11] The liquid crystal display element according to [5], wherein the liquid crystal composition contains at least one liquid crystal compound represented by Formula (1).

In the formula (1), R ¹ is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons; ring A is 1,4-cyclohexylene, 1 , 4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, 1,3 -Dioxane-2,5-diyl or tetrahydropyran-2,5-diyl; Z ¹ is a single bond, ethylene, carbonyloxy or difluoromethyleneoxy; and X ¹ and X ² are each independently It is hydrogen or fluorine; Y ¹ is fluorine, chlorine, at least one hydrogen alkyl having 1 to 12 carbon atoms which is replaced by halogen, replace at least one hydrogen with halogen Is alkoxy having 1 to 12 carbon atoms, or at least one hydrogen is alkenyloxy having 2 carbon atoms replaced by halogen 12; a is 1, 2, 3 or 4. When a is 2 or more, a plurality of rings A and Z ¹ may be the same or different.
[12] The liquid crystal display element according to the above [5], wherein the liquid crystal composition contains at least one liquid crystal compound represented by Formula (3).

In formula (3), R ⁴ and R ⁵ are each independently an alkyl of 1 to 12 carbons, an alkoxy of 1 to 12 carbons, an alkenyl of 2 to 12 carbons, an alkenyloxy of 2 to 12 carbons, Or an alkyl having 1 to 12 carbon atoms in which at least one hydrogen is replaced by a halogen; ring D and ring F are each independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,2 4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine, or tetrahydropyran-2,5-diyl; ring E is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-di Le, or 7,8-be difluorochroman-2,6-diyl; ^{Z 3} and ^{Z 4} are each independently a single bond, ethylene, carbonyloxy, or methyleneoxy; c is 1, 2, or 3; d is 0 or 1; the sum of c and d is 3 or less. Incidentally, when c is 2 or more, a plurality of ring D, may be different even Z ³ are each identical.
[13] The liquid crystal display element according to [11] or [12], wherein the liquid crystal composition further contains a compound of the formula (2).

In formula (2), R ² and R ³ are each independently alkyl of 1 to 12 carbons, alkoxy of 1 to 12 carbons, alkenyl of 2 to 12 carbons, and at least one hydrogen is replaced by halogen C 1-12 alkyl or C 2-12 alkenyl in which at least one hydrogen is replaced by halogen; ring B and ring C are each independently 1,4-cyclohexylene, 1 4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene; Z ² is a single bond, ethylene or carbonyloxy; b is 1, 2 Or 3 When b is 2 or more, the plurality of rings B and Z ² may be the same or different.
[14] The liquid crystal display element according to the above [10], wherein the liquid crystal composition contains at least one compound represented by Formula (6).

In formula (6), each R ⁶ independently represents cyano (CN), fluorine, chlorine or any —CH ₂ — in the group being replaced by oxygen, sulfur, —COO— or —OCO— And C 1 -C 10 alkyl which may be substituted with the proviso that oxygen is not adjacent, and in the alkyl, any hydrogen of the group may be replaced by halogen. MG ⁶ each independently represents a mesogen, Sp is an alkylene having 5 to 40 carbon atoms, and each X ⁶ is independently -CO-O-, -O-CO-, -CH ₂ -O _{-, - O-CH 2 -} , - CF 2 -O -, - O-CF 2 -, - CH 2 -CH 2 -, - C≡C -, - CH (CH 3) -N = CH- or a single It is a bond. In formula (6), R ⁶ , MG ⁶ and X ⁶ may be the same or different.

  The composite fiber of the present invention does not require an alignment film to form a liquid crystal display element, and therefore, a liquid crystal display element excellent in productivity can be obtained without undergoing a complicated process. Furthermore, since a high temperature treatment in the alignment film formation process is not required, it becomes possible to obtain a flexible liquid crystal display device using a plastic substrate or the like. In addition, it becomes easy to align the helical axes of the cholesteric liquid crystals in a fixed direction, and the enlargement of the ULH type liquid crystal display element (larger screen) is made possible.

FIG. 1 is a perspective view of a liquid crystal inclusion composite fiber. FIG. 2 is a perspective view of a composite fiber assembly and a liquid crystal display element. FIG. 3 is a schematic view of a composite fiber manufacturing apparatus using a double pipe nozzle. FIG. 4 is a diagram showing the operation of the IPS type liquid crystal display device when a liquid crystal composition having positive dielectric anisotropy is used, wherein (a) and (b) are liquid crystals of the liquid crystal display device ( (C), (d) is the top view which looked at the liquid crystal display element from the upper direction. FIG. 5 is a schematic view of a liquid crystal-containing composite fiber and a composite fiber assembly in a liquid crystal display device of ULH type, (a) is a plan view of the liquid crystal-containing composite fiber, and (b) is a composite fiber assembly It is a top view of the body. FIG. 6 is a polarized light micrograph of the conjugate fiber obtained in Example 1. FIG. 7 is a scanning electron micrograph of the composite fiber obtained in Example 1. FIG. 8 is a scanning electron micrograph of the composite fiber obtained in Example 2. FIG. 9 is a plan view of a substrate for a liquid crystal display device in which comb-shaped electrodes are arranged. FIG. 10 is a scanning electron micrograph showing the switching of light and dark when applying and removing a rectangular wave to the liquid crystal display element substrate.

  Hereinafter, although a plurality of embodiments of the liquid crystal display element of the present invention are illustrated in detail, the specific configuration of the liquid crystal display element of the present invention is not limited to the one illustrated in the figure.

  The liquid crystal display device of the present invention comprises at least one substrate generally used, and a composite fiber assembly which is disposed on the substrate and is formed by uniaxially aligning the liquid crystal inclusion composite fiber.

  FIG. 1 is a perspective view of a liquid crystal-containing composite fiber 10 (hereinafter sometimes referred to as “composite fiber 10”) used in the present invention. The liquid crystal-containing composite fiber 10 is a sheath-core type composite fiber having a liquid crystal composition as a core component. Specifically, the liquid crystal inclusion composite fiber 10 is a liquid crystal composition 2a constituting the core component 2 and a sheath component existing on the outer periphery of the core component 2 and constituting the sheath component 4 which is the outer shell of the liquid crystal inclusion composite fiber 10 And the forming material 4a. Although the liquid crystal composition 2a schematically represents the liquid crystal molecular alignment, as shown in FIG. 1, even if the major axis of the liquid crystal molecules is parallel to the fiber, the major axis of the liquid crystal molecules is orthogonal to the fiber direction May be

  FIG. 2 is a perspective view of the composite fiber assembly 20 and the liquid crystal display element 100. FIG. The liquid crystal display element 100 includes at least one substrate 30 and a composite fiber assembly 20 which is disposed on the substrate 30 and is formed by uniaxially aligning the liquid crystal inclusion composite fiber 10. Plural composite fibers 10 can be disposed on a substrate 30 to form a composite fiber assembly 20. In this case, the binder 40 is preferably filled. By forming in this manner, the liquid crystal display element 100 can be used. Since the sheath portion is not switched by voltage application, it is preferable that the composite fiber 10 form a plurality of layers as shown in FIG. 2 because the area to be switched by voltage application is wider. Of course, even if the composite fiber 10 is a single layer, switching by voltage application is possible. That is, the liquid crystal layer can be formed on the substrate without forming the alignment film as in the prior art, and the manufacturing cost of the liquid crystal display element can be significantly suppressed. The substrate 30 can also be made of a glass substrate, but the liquid crystal display element 100 can be configured as a flexible liquid crystal display element that can be bent by being made of a bendable resin substrate or the like. The liquid crystal display element 100 further includes an electrode (not shown) disposed on the substrate 30 and applying an electric field and a voltage to the composite fiber assembly 20 based on a signal from the outside. The liquid crystal display element 100 may be provided with another member such as a thin film transistor element.

  The sheath component forming material 4 a of the sheath component 4 and the liquid crystal composition 2 a of the core component 2 are substantially separated. "Substantially separated" means that both components may be slightly mixed at the interface, but one component is not heavily or deeply intruded into the other component. Under such a configuration, the liquid crystal composition 2a constituting the core component 2 can move smoothly without being blocked by the sheath component 4, and the display characteristics of the liquid crystal display element 100 are improved. For example, a drop in drive voltage can be mentioned.

  The liquid crystal-containing composite fiber 10 is formed by discharging the sheath component-forming material 4 a and the liquid crystal composition 2 a from different discharge devices, that is, different nozzles. That is, in the liquid crystal-containing composite fiber 10 of the present embodiment, the sheath component 4 and the liquid crystal composition 2 a are not once separated into the sheath component 4 and the core component 2 after being mixed once. Since each of sheath component-forming material 4a and liquid crystal composition 2a individually becomes sheath component 4 and core component 2 from the beginning, sheath component-forming material 4a and liquid crystal composition 2a are substantially separated. Secured. The manufacturing method of the liquid crystal inclusion composite fiber 10 will be described later (FIG. 3).

  In this example, the liquid crystal molecules 2b (described later) constituting the liquid crystal composition 2a of the core component 2 can move smoothly without being blocked by the sheath component 4 relatively. Therefore, the voltage applied to drive the liquid crystal composition 2a by the electrode can be in the range of 50 V or less, and can be suppressed to a low value. The preferred applied voltage is 30 V or less, more preferably 20 V or less. Here, the applied voltage refers to a voltage required to obtain a transmittance of 90% with respect to the transmittance in a state where the transmittance is saturated by the application of a sufficient voltage. The voltage application condition is a 60 Hz rectangular wave, and the value of the voltage is an effective value.

  Furthermore, in the composite fiber assembly 20, it is preferable that the binder 40 be filled between the liquid crystal inclusion composite fibers 10. The binder 40 plays the role of facilitating the handling and protecting the liquid crystal-containing composite fiber 10 by forming the composite fiber assembly 20 in the form of a laminate of the liquid crystal-containing composite fiber 10. In addition, by reducing the space between the liquid crystal inclusion composite fibers 10, scattering of light is suppressed. Furthermore, when the liquid crystal display element 100 is a flexible liquid crystal display element, the thickness of the composite fiber aggregate 20 is unlikely to change due to the action of the binder 40 even when bent, and the change in luminescent color before and after bending is suppressed. It is possible. The material used for the binder 40 is preferably a material having a refractive index close to that of the sheath component, and most preferably a material having the same refractive index as the sheath component, but is not particularly limited.

  The liquid crystal composition 2a used in the present invention is preferably of two types, one is a nematic phase or a liquid crystal composition α driven with a chiral nematic phase having a helical pitch longer than 10 μm, and the other is It is a liquid crystal composition β driven in the cholesteric phase in which the helical pitch is shorter than 1 μm. First, the liquid crystal composition α has a dielectric anisotropy of +2 or more or −2 or less, and is driven mainly by the dielectric anisotropy of the liquid crystal composition. On the other hand, the liquid crystal composition β is mainly driven by the flexoelectric effect. The liquid crystal compositions α and β will be described later. Hereinafter, each member which comprises the liquid crystal display element 100 is demonstrated separately.

<Composite fiber>
FIG. 1 is a perspective view of a liquid crystal-containing composite fiber 10 (hereinafter sometimes referred to as “composite fiber 10”) used in the present invention. The liquid crystal inclusion composite fiber 10 in the present invention is a sheath-core type composite fiber 10 having the liquid crystal composition 2 a as a core component 2. Although not particularly limited, in the core component 2, it is preferable that the liquid crystal composition 2a be continuously distributed. Here, the state in which the liquid crystal composition 2a is continuously distributed means that the liquid crystal composition 2a is disposed without interruption over the entire region of the core component 2, and the liquid crystal composition 2a is in the region of the core component 2 It means that the sum of the lengths of the interrupted portions is less than 1% of the total length of the composite fiber 10. If the liquid crystal composition 2a is discontinuous, a portion not driven by voltage application is produced at that portion, but if continuously distributed without interruption, a portion not driven is not produced, and the driving area is reduced. It is possible to make it larger.

  The degree of orientation of the liquid crystal composition α exhibiting a nematic phase in the liquid crystal composition 2a in the composite fiber 10 in the present invention is not particularly limited, but is preferably in the range of 0.5 to 1.0, More preferably, it is in the range of 1.0. Also, the orientation direction is not particularly limited, but is preferably parallel or perpendicular to the fiber axis. With such an alignment direction, it can be suitably used as a liquid crystal display element 100 with high light contrast and little light leakage.

  When the liquid crystal composition 2a is a cholesteric liquid crystal or a chiral nematic liquid crystal having a helical structure, the helical structure may have a helical axis parallel to or perpendicular to the fiber axis. When the helical structure has a helical axis parallel to the fiber axis, it can be suitably used, for example, as a liquid crystal display element with ultra-fast response, such as the ULH system. In addition, when the helical axis is perpendicular to the fiber axis, for example, it can be suitably used as a wavelength selective reflection element or the like.

  The sheath component-forming material 4a of the sheath component 4 of the conjugate fiber 10 in the present invention is not particularly limited, but is preferably a fiber-forming material. Examples of the fiber-forming material include polyvinyl alcohol, polyethylene glycol, polyethylene oxide, polyvinyl pyrrolidone, polyethylene, polypropylene, polyethylene terephthalate, polylactic acid, polyamide, polyurethane, polystyrene, polysulfone, polyether sulfone, polyvinylidene fluoride, polyacrylonitrile, poly Polymeric materials such as methyl methacrylate, polyglycolic acid, polycaprolactone, polyvinyl acetate, polycarbonate, polyimide, polyetherimide, cellulose, cellulose derivatives, chitin, chitosan, collagen, gelatin and their copolymers, alumina, silica And inorganic materials such as titania, zirconia, and hydroxyapatite. These fiber-forming materials may be used alone or in combination of two or more. The mixing ratio in the case of mixing and using is not particularly limited, and can be appropriately set in consideration of the physical properties of the obtained fiber. If the sheath component-forming material 4a of the sheath component 4 is a non-crystalline polymer having transparency, the amount of light transmission can be increased, and therefore it is preferable because it can be suitably used as a liquid crystal element. Examples of such non-crystalline polymers include poly (methyl methacrylate), polyvinyl acetate, polyvinyl pyrrolidone, polycarbonate, polystyrene and gelatin.

  The sheath component-forming material 4a of the sheath component 4 of the present invention is preferably a component having a refractive index close to the refractive index of the liquid crystal composition 2a because light scattering at the interface can be reduced. Examples of the sheath component-forming material 4 a of the sheath component 4 include polyvinyl pyrrolidone and the like.

  The outer diameter (d in FIG. 1) of the composite fiber 10 of the present invention is not particularly limited, but the average outer diameter is preferably 5 μm or less, more preferably 3 μm or less, and 1 μm or less It is further preferred that If the average outer diameter is 3 μm or less, the degree of orientation of the liquid crystal composition 2a in the fiber can be increased, and if 1 μm or less, the degree of orientation can be further increased. Further, from the viewpoint of suppressing the leakage of the liquid crystal composition in the fiber, the average outer diameter is preferably 50 nm or more, and more preferably 100 nm or more.

  When the cross-sectional shape of the composite fiber 10 is elliptical, it is not particularly limited, but the length of the major axis of the outer diameter is preferably 7 μm or less, and the length of the minor axis is preferably 3 μm or less. Although it does not specifically limit as a cross-sectional area of the composite fiber 10, It is preferable that it is 20 square micrometers or less, and it is more preferable that it is 8 square micrometers or less. It is particularly preferred that it is 1 square micrometer or less.

  The variation in the outer diameter of the composite fiber 10 of the present invention is not particularly limited, but the variation coefficient (CV value) of the outer diameter is preferably 20% or less, more preferably 15% or less, and 10% or less Is particularly preferred. If the CV value of the outer diameter is 20% or less, it is preferable because the light transmission amount and light reflection amount of each fiber become uniform. Here, the CV value of the outer diameter is a value obtained by dividing the standard deviation of the outer diameter of each fiber by the average outer diameter and expressing it as a percentage.

  The inner diameter (that is, the outer diameter of the core component and L of FIG. 1) of the composite fiber 10 in the present invention is not particularly limited, but the average inner diameter is preferably 4.0 μm or less, and 2.5 μm or less Is more preferable, and 0.8 μm or less is more preferable. If the average outer diameter is 4.0 μm or less, the alignment of the liquid crystal composition 2a in the fiber can be made uniform, and if it is 2.5 μm or less, the alignment can be made more uniformly, and 0.8 μm or less If it is, it becomes possible to make orientation more uniform. Further, from the viewpoint of securing a drive area, the average outer diameter is preferably 10 nm or more, and more preferably 50 nm or more.

  As a method of measuring the inner diameter of the composite fiber 10, a method of measuring the inner diameter from an image taken with a polarization microscope or a transmission electron microscope, cutting the composite fiber 10 in a direction perpendicular to the fiber axis, The method of measuring an internal diameter from the image image | photographed with the scanning electron microscope, etc. are mentioned.

  The thickness of the sheath component 4 in the present invention is not particularly limited, but is preferably in the range of 0.1 to 1.0 μm, and more preferably in the range of 0.2 to 0.5 μm. If the thickness of the sheath component is 0.1 μm or more, the contained liquid crystal composition 2a is unlikely to leak out of the fiber, and if 0.2 μm or more, the liquid crystal can be sufficiently prevented from leaking. Further, if the thickness of the sheath component 4 is 1.0 μm or less, light scattering can be reduced, and if 0.5 μm or less, light scattering can be sufficiently suppressed. Here, the thickness of the sheath component 4 can be obtained by dividing the sum of the outer diameter d and the inner diameter L of the composite fiber 10 by two.

  Although it does not specifically limit as a cross-sectional shape of the composite fiber 10 of this invention, A circle, an ellipse, flat shape, semicircle etc. can be mentioned. The cross-sectional shape of the composite fiber 10 can be appropriately set in view of the physical properties of the obtained fiber and the orientation of the liquid crystal component.

<Method of manufacturing composite fiber>
The method for producing the composite fiber 10 of the present invention can be exemplified by melt spinning, dry spinning, wet spinning, spunbonding, meltblown, flash spinning, electrostatic spinning, force spinning, etc. From the viewpoint of obtaining fibers, the electrostatic spinning method is preferred. Although the electrostatic spinning method is described below, it is not limited thereto.

  The electrostatic spinning method is a method in which a spinning solution is discharged and an electric field is applied to convert the discharged spinning solution into fibers to obtain fibers on a collector. For example, a spinning solution is extruded from a nozzle and an electric field is applied to perform spinning, a spinning solution is foamed and an electric field is applied to conduct spinning, a spinning solution is introduced to the surface of a cylindrical electrode and an electric field is applied to perform spinning. Can be mentioned. According to this method, uniform fibers with a diameter of 10 nm to 10 μm can be obtained.

  The method for producing the composite fiber 10 in the present invention is a method in which a sheath solution and a liquid crystal material are separately discharged from a double tube nozzle and electrostatic spinning is performed, and a spinning solution in which a polymer, a liquid crystal material and a solvent are mixed is electrostatically spun In addition to the method of phase separation, it is preferable to use a method in which the sheath solution and the liquid crystal composition are separately discharged from a double tube nozzle and electrostatic spinning is performed because of easy drive of the liquid crystal composition. The liquid crystal-encapsulated composite fiber produced by the method of subjecting a spinning solution in which a polymer, a liquid crystal composition and a solvent are mixed to electrostatic spinning as well as performing phase separation causes the polymer component to be mixed with the liquid crystal material. The alignment is disturbed, and good characteristics can not be obtained as a liquid crystal display element.

  FIG. 3 is a schematic view of a composite fiber manufacturing apparatus 200 using a double pipe nozzle. Composite fiber manufacturing apparatus 200 has double tube nozzle 210, outer nozzle 212 of double tube nozzle 210 discharges sheath solution L1 which is sheath component formation material 4a, and inner nozzle 214 is liquid crystal composition L2 (2a )). A collector 216 for collecting fibers is provided below the double tube nozzle 210. Further, the power supply 218 applies an electric field between the double-tube nozzle 210 and the collector 216 to fiberize the discharged spinning solution (the sheath solution L1 and the liquid crystal composition L2).

  As described above, in this apparatus, the sheath component-forming material 4a (the sheath solution L1) and the liquid crystal composition L2 (2a) are discharged from different nozzles 212 and 214. In this method, the liquid crystal-containing composite fiber 10 is formed while the sheath component-forming material 4a and the liquid crystal composition 2a individually become the sheath component 4 and the core component 2, and the sheath component-forming material 4a and the liquid crystal composition A state in which the object 2a and the object 2a are substantially separated is ensured.

  The sheath solution is not particularly limited as long as it has spinnability, but a solution in which a fiber-forming material (sheath component-forming material 4a) is dissolved in a solvent or a fiber-forming material is melted by heat or laser irradiation A thing etc. can be used. As the sheath solution used in the present invention, it is possible to easily control the fineness and uniformity of the diameter of the composite fiber 10 and the continuity and orientation of the liquid crystal composition 2a by using a solution of the fiber forming material dissolved in a solvent. Preferred.

  Examples of the fiber-forming material include polyvinyl alcohol, polyethylene glycol, polyethylene oxide, polyvinyl pyrrolidone, polyethylene, polypropylene, polyethylene terephthalate, polylactic acid, polyamide, polyurethane, polystyrene, polysulfone, polyether sulfone, polyvinylidene fluoride, polyacrylonitrile, poly Polymeric materials such as methyl methacrylate, polyglycolic acid, polycaprolactone, polyvinyl acetate, polycarbonate, polyimide, polyetherimide, cellulose, cellulose derivatives, chitin, chitosan, collagen, and copolymers of these, alumina, silica, Inorganic materials such as titania, zirconia, hydroxyapatite and the like can be mentioned. These fiber-forming materials may be used alone or in combination of two or more. The mixing ratio in the case of mixing and using is not particularly limited, and can be appropriately set in consideration of the physical properties of the obtained fiber. In the composite fiber 10 of the present invention, if the sheath component-forming material 4a of the sheath component 4 is a non-crystalline polymer, it can be suitably used as an optical device, which is preferable. Examples of such non-crystalline polymers include poly (methyl methacrylate), polyvinyl acetate, polyvinyl pyrrolidone, polycarbonate and polystyrene.

  As a solvent for dissolving the fiber forming material, for example, water, methanol, ethanol, propanol, acetone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, toluene, xylene And pyridine, formic acid, acetic acid, tetrahydrofuran, dichloromethane, chloroform, dichlorobenzene, 1,1,1,3,3,3-hexafluoroisopropanol, and mixtures thereof. Use of these mixtures is preferable because the continuity and orientation of the liquid crystal composition 2a and the diameter of the composite fiber 10 can be easily controlled. The composition of the mixture is not particularly limited, but is preferably a mixture of a polar solvent and a nonpolar solvent. Examples of polar solvents include water, methanol, ethanol, propanol, acetone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone and the like, and nonpolar solvents are exemplified. And toluene, xylene, tetrahydrofuran, chloroform, dichloromethane, dichlorobenzene and the like. Moreover, a mixing ratio is not specifically limited, For example, when mixing two types of solvents, the range of 5: 95-95: 5 can be illustrated by weight ratio.

  Additives may be further contained in the sheath solution for the purpose of improving the stability of the electrospinning and the fiber formation. The additive is, for example, an anionic surfactant such as sodium dodecyl sulfate, a cationic surfactant such as tetrabutyl ammonium bromide, a nonionic surfactant such as polyoxyethylene sorbitamon monolaurate, sodium chloride And inorganic salts. The concentration of the additive is preferably in the range of 0.1 to 5% by weight, more preferably 0.2 to 2% by weight, based on the fiber-forming material. If it is 0.1% by weight or more, an effect corresponding to use is obtained, and if it is 5% by weight or less, the influence on the liquid crystal driving is reduced, which is preferable.

  As long as the effects of the present invention are not significantly impaired, components other than the above may be included as components of the sheath solution.

  The method for preparing the sheath solution is not particularly limited, and methods such as stirring and sonication can be mentioned. Also, the order of mixing is not particularly limited, and may be mixed simultaneously or sequentially. The stirring time in the case of preparing the sheath solution by stirring is not particularly limited as long as the fiber-forming material is uniformly dissolved in the solvent, and may be, for example, about 1 to 24 hours.

  In order to obtain a fiber by electrostatic spinning, it is preferable to adjust the viscosity of the sheath solution to a range of 10 to 5,000 mPa · s, and more preferably to a range of 50 to 2,000 mPa · s. When the viscosity is 10 mPa · s or more, a spinnability for forming a fiber is obtained, and when the viscosity is 5,000 mPa · s or less, it is easy to discharge the sheath solution. If the viscosity is in the range of 50 to 2,000 mPa · s, it is preferable because good spinnability can be obtained in a wide range of spinning conditions. The viscosity ratio of the liquid crystal composition 2a to the sheath solution (viscosity of the liquid crystal composition) is not particularly limited, but is preferably in the range of 0.02 to 2.00, and preferably 0.05 to 0. More preferably, it is in the range of 5. Since the stability of the interface of the liquid crystal composition 2a and the sheath solution is excellent when the viscosity ratio is 0.02 or more, the composite fiber 10 excellent in the continuity and the orientation of the liquid crystal is easily obtained, and 2 is preferable. If it is not more than .00, the spinnability of the sheath solution can be sufficiently satisfied, and the viscosity of the liquid crystal composition 2a can be suppressed to a low level, so that good characteristics as the liquid crystal display element 100 can be satisfied. The viscosity of the sheath solution can be adjusted by appropriately changing the molecular weight and concentration of the fiber-forming material, the type of the solvent and the mixing ratio.

  In the composite fiber 10 obtained by electrostatic spinning, in order to obtain a fiber excellent in the continuity and orientation of the liquid crystal composition 2a, the conductivity of the sheath solution is in the range of 0.1 to 10.0 mS / m. It is preferable to adjust, and it is more preferable to adjust to the range of 0.5-2.0 mS / m. When the conductivity of the sheath solution is 0.1 mS / m or more, the speed drawn by the electric field is increased, and thus it is easy to obtain the composite fiber 10 excellent in the continuity and orientation of the liquid crystal composition 2a It is possible to reduce the diameter of the fibers 10. If the conductivity of the solution is 10.0 mS / m or less, electric field interference during spinning can be reduced, and stable and uniform fibers can be obtained. The conductivity of the sheath solution can be adjusted by appropriately changing the type and mixing ratio of the solvent, and the type and concentration of the additive.

  The temperature of the spinning solution may be spinning at normal temperature, or may be spinning by heating and cooling. As a method of discharging a spinning solution, for example, a method of discharging a spinning solution filled in a syringe using a pump from a nozzle can be mentioned. Although it does not specifically limit as an internal diameter of a nozzle, It is preferable that it is the range of 0.1-1.5 mm. Moreover, when using a double pipe | tube nozzle, it is preferable that it is a range of 0.1-0.5 mm, and, as for the internal diameter of the nozzle by the side of a core, it is more preferable that it is 0.1-0.3 mm. The inner diameter of the nozzle on the sheath side is preferably in the range of 0.2 to 1.5 mm, and more preferably in the range of 0.2 to 0.8 mm.

  Although it does not specifically limit as discharge amount of a spinning solution, It is preferable that it is 0.1-15 ml / hr. When the sheath solution and the liquid crystal composition 2a are separately ejected, the ejection amount of the sheath solution is preferably in the range of 0.5 to 15 mL / hr, and in the range of 1.0 to 8.0 mL / hr. It is more preferable that The discharge amount of the liquid crystal composition 2a is preferably in the range of 0.1 to 3 mL / hr, and more preferably in the range of 0.1 to 1.0 mL / hr.

  The ratio of the discharge amount of the liquid crystal composition 2a to the sheath solution (discharge amount of the liquid crystal composition) is preferably in the range of 0.01 to 1.00, and is preferably 0.05 to 0. More preferably, it is in the range of .30. The continuity of the liquid crystal composition 2a can be enhanced if the ratio of the discharge amount of the liquid crystal composition 2a to the sheath solution is 0.01 or more, and if the ratio is 0.05 or more, the continuity is sufficient. Is possible. Further, if the ratio is 1.00 or less, the liquid crystal composition 2a is less likely to leak from the fiber, and if it is 0.30 or less, the leakage is less likely to occur, and the outer diameter and the inner diameter of the composite fiber 10 can be reduced. Also play.

  The method of applying an electric field is not particularly limited as long as an electric field can be formed between the nozzle and the collector. For example, a high voltage may be applied to the nozzle and the collector may be grounded. The voltage to be applied is not particularly limited as long as fibers are formed, but is preferably in the range of 5 to 50 kV. Moreover, the distance between the nozzle and the collector is not particularly limited as long as fibers are formed, but the range of 5 to 30 cm is preferable. The collector may be anything that can collect the spun fibers, and the material, shape, and the like thereof are not particularly limited. As a material of the collector, a conductive material such as metal is suitably used. Although it does not specifically limit as a shape of a collector, For example, flat form, conveyor form, drum form, disk form, a lattice form etc. can be mentioned.

  The method of collecting the composite fiber 10 in the present invention is not particularly limited, but a method of rotating a drum-shaped or disk-shaped collector at high speed, and a method of using a lattice-shaped collector are preferable. By using such a collection method, it is possible to arrange the fibers in any direction. The rotational speed of the drum-shaped or disc-shaped collector is not particularly limited, but the peripheral speed is preferably in the range of 50 to 2,000 m / min, and more preferably in the range of 100 to 1,000 m / min. Is more preferred. If the circumferential speed is 50 m / min or more, the composite fibers 10 can be arranged along the rotational direction, and if 100 m / min or more, the arrangement becomes sufficient. Moreover, if it is 2,000 m / min or less, it is possible to reduce the influence of the airflow which arises by rotation, if it is 1,000 m / min or less, it can fully reduce and it becomes possible to collect stably. . When using a grid | lattice-like collector, as a space | interval of a grid | lattice, the range of 10-200 mm can be illustrated, for example. Moreover, as a shape of a grid | lattice, a square, a rectangle, a rhombus, an equilateral triangle, an equilateral hexagon, a waveform etc. can be illustrated.

<Complex fiber assembly>
The composite fiber assembly 20 in the present invention is not particularly limited, but it is preferable that the composite fibers 10 containing a liquid crystal be uniaxially aligned. When the composite fiber 10 is uniaxially aligned, various properties of the composite fiber 10 can be anisotropically exhibited, and for example, it can be suitably used as a high contrast liquid crystal display element. The degree of arrangement of the composite fibers 10 can be evaluated by the standard deviation of the fiber arrangement angle, and the smaller the standard deviation of the fiber arrangement angle, the higher the degree of arrangement. The standard deviation of the fiber arrangement angle is preferably 20 ° or less, more preferably 15 ° or less.

  The composite fibers 10 may be randomly arranged. When arranged randomly, it is possible to express various characteristics isotropically.

  The thickness of the composite fiber assembly 20 is not particularly limited, but is preferably in the range of 1 to 20 μm, and more preferably in the range of 2 to 10 μm. If the thickness is 1 μm or more, the function as the liquid crystal element can be sufficiently satisfied, and if the thickness is 20 μm or less, the light transmission amount can be sufficiently increased.

  The area ratio occupied by the composite fibers 10 in the composite fiber assembly 20 is preferably 80% or more, and more preferably 95% or more.

  Plural composite fibers 10 are arranged on a substrate 30 and filled with a binder 40 to form a composite fiber assembly 20. That is, the liquid crystal layer can be formed on the substrate 30 without forming the alignment film as in the conventional case, and the manufacturing cost of the liquid crystal display element can be significantly suppressed.

  The liquid crystal is continuously distributed inside the fiber, and the composite fiber 10 in the present invention can be suitably used as a liquid crystal element for display or liquid crystal element for wavelength selective reflection.

First Embodiment
Next, a first embodiment of the present invention will be described using FIG. The liquid crystal display element of the present embodiment relates to an element of an IPS (In-Plane Switching) system which switches liquid crystal molecules while being substantially parallel to a substrate surface, as an element capable of achieving a wide viewing angle.

  4 (a) and 4 (b) are sectional views showing the operation of the liquid crystal (liquid crystal molecules) of the liquid crystal display element 100 of this embodiment, and FIGS. 4 (c) and 4 (d) show the liquid crystal display element from above. Represents a plan view. In FIG. 4, the binder 40 shown in FIG. 2 and other members such as thin film transistor elements are not shown. A cross-sectional view at the time of no application of electric field and voltage is shown in FIG. 4A, and a plan view at that time is shown in FIG. There is a pair of transparent substrates 30 (30a, 30b), and linear electrodes 25, 26 are formed inside the substrate 30b. As shown in FIGS. 4 (a) and 4 (b), a pair of polarizing plates 50a and 50b are provided outside the pair of substrates 30 (30a and 30b) (FIGS. 4 (c) and 4 (d)). But omitted). In the present embodiment, the linear electrodes 25 and 26 are shown as the electrodes, but the shape of the electrodes is not particularly limited, and various shapes such as V shape (V shape) or zigzag shape in plan view It can take a shape. In addition, not only a flat surface but also a raised shape or an uneven shape may be used in the cross sectional view, and there is no particular limitation. Any electrode capable of applying an electric field substantially parallel to the substrate can be employed. Therefore, for example, a fringe field switching mode liquid crystal display device is also applicable.

  The basic configuration of the liquid crystal display element 100 of the present embodiment is the same as the example shown in FIG. Then, an electric field (voltage) is applied between the electrode 25 and the electrode 26, and an electric field is generated in a direction substantially parallel to the substrate 30 (30a, 30b) (the left and right direction in FIGS. 4A and 4B). Do. As a result, liquid crystal molecules 2b constituting the liquid crystal composition 2a in the liquid crystal inclusion composite fiber 10 rotate in a plane substantially parallel to the substrates 30 (30a, 30b), and the switching operation is performed.

  In the present embodiment, the liquid crystal molecules 2b constituting the liquid crystal composition 2a have a slight angle, typically 45, with respect to the longitudinal direction of the electrodes 25 and 26 (vertical direction in FIG. 4C) when no electric field is applied. It is oriented to have an angle of around °°. Next, when the electrode 25 and the electrode 26 apply an electric field E, when the dielectric anisotropy value of the liquid crystal composition 2a is positive, the liquid crystal in the electric field direction as shown in FIG. 4 (b), (d) The molecule 2b changes its direction. When the dielectric anisotropy of the liquid crystal composition 2a is negative, the liquid crystal molecules 2b change their direction in the direction perpendicular to the electric field direction. As in the case where the shape of the electrode is arbitrary, the direction of the liquid crystal molecules 2b when no electric field is applied and when the electric field is applied is not limited to that of the present embodiment. The direction of the liquid crystal molecules 2b may be changed between the time of no application of an electric field and the time of application of the electric field to change the light transmittance.

  The electrodes 25 and 26 can apply an electric field and a voltage in a direction substantially parallel to the substrate 30 (30a, 30b) (the left and right direction in FIGS. 4A and 4B). It is called an electric field drive electrode. The liquid crystal display element 100 of this type is called an IPS (In-Plane Switching) type liquid crystal display element, and is a liquid crystal display element which has a small viewing angle dependency and can achieve a wide viewing angle.

  By arranging the two polarizing plates 50a and 50b at a predetermined angle, it becomes possible to change the light transmittance by applying an electric field. In each of FIGS. 4 (a) to 4 (d), two rows of liquid crystal-containing composite fibers 10 are shown for convenience, but in actuality, more liquid crystal-containing composite fibers 10 are in the height direction (FIG. They are arranged in the vertical direction a) and (b) and in the in-plane direction (horizontal direction in FIGS. 4 (c) and 4 (d)).

  Although the electrodes 25 and 26 are separately formed on the upper and lower substrates 30a and 30b in FIG. 4, they may be formed on only one of the substrates. The dielectric anisotropy value Δε of the liquid crystal composition 2a is preferably set to +2 or more (Δε ≧ + 2) or −2 or less (Δε ≦ −2).

  According to the embodiment as described above, an alignment film is unnecessary, and a flexible liquid crystal display device using a flexible substrate with low heat resistance can be easily manufactured. The IPS-type flexible liquid crystal display device is thin and light, can be rolled and stored, is convenient for carrying, and can ensure a wide viewing angle. Further, by solidifying the composite fiber assembly 20 with the binder 40, a change in thickness of the liquid crystal portion through which light is transmitted even when bent is suppressed, and a flexible liquid crystal display device can be further easily realized.

  As described above, the liquid crystal composition used in the present invention is preferably of two types, one is a nematic phase or a liquid crystal composition α driven with a chiral nematic phase having a helical pitch longer than 10 μm, Is a liquid crystal composition β driven in the cholesteric phase with a helical pitch shorter than 1 μm. First, the liquid crystal composition α has a dielectric anisotropy of +2 or more or −2 or less, and is driven mainly by the dielectric anisotropy of the liquid crystal composition. The dielectric anisotropy is preferably +5 or more, more preferably +10 or more for positive liquid crystals, and preferably -3 or less, more preferably -4 or less for negative liquid crystals. On the other hand, the liquid crystal composition β is mainly driven by the flexoelectric effect.

<Liquid crystal composition α>
First, the liquid crystal composition α used suitably for the liquid crystal display device of the present embodiment, that is, the liquid crystal display device of the IPS type will be described. The liquid crystal composition α includes a liquid crystal compound represented by the following formulas (1) to (3), and at least one halogen-based liquid crystal compound represented by the formula (1) or the formula (3) The liquid crystal composition containing can be mentioned.

In the formula (1), R ¹ is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons; ring A is 1,4-cyclohexylene, 1 , 4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, 1,3 -Dioxane-2,5-diyl or tetrahydropyran-2,5-diyl; Z ¹ is a single bond, ethylene, carbonyloxy or difluoromethyleneoxy; and X ¹ and X ² are each independently is hydrogen or fluorine; Y ¹ is fluorine, chlorine, at least one hydrogen of 1 to 12 carbon atoms which is replaced by halogen alkyl, at least one hydrogen substituted with halogen Alkoxy having 1 to 12 carbon atoms, or at least one hydrogen is alkenyloxy having 2 to 12 carbon atoms which is replaced by halogen; a is 1, 2, 3 or 4. When a is 2 or more, a plurality of rings A and Z ¹ may be the same or different.

In formula (2), R ² and R ³ are each independently alkyl of 1 to 12 carbons, alkoxy of 1 to 12 carbons, alkenyl of 2 to 12 carbons, and at least one hydrogen is replaced by halogen C 1-12 alkyl or C 2-12 alkenyl in which at least one hydrogen is replaced by halogen; ring B and ring C are each independently 1,4-cyclohexylene, 1 4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene; Z ² is a single bond, ethylene or carbonyloxy; b is 1, 2 Or 3 When b is 2 or more, the plurality of rings B and Z ² may be the same or different.

In formula (3), R ⁴ and R ⁵ are each independently an alkyl of 1 to 12 carbons, an alkoxy of 1 to 12 carbons, an alkenyl of 2 to 12 carbons, an alkenyloxy of 2 to 12 carbons, Or an alkyl having 1 to 12 carbon atoms in which at least one hydrogen is replaced by a halogen; ring D and ring F are each independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,2 4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine, or tetrahydropyran-2,5-diyl; ring E is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-di Le, or 7,8-be difluorochroman-2,6-diyl; ^{Z 3} and ^{Z 4} are each independently a single bond, ethylene, carbonyloxy, or methyleneoxy; c is 1, 2, or 3; d is 0 or 1; the sum of c and d is 3 or less. Incidentally, when c is 2 or more, a plurality of ring D, may be different even Z ³ are each identical.

As a halogen-type liquid crystal compound represented by Formula (1), the compound represented by Formula (1-1) to Formula (1-34) can be mentioned, for example. In formulas (1-1) to (1-34), R ¹ is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons.

As a liquid crystal compound represented by Formula (2), the compound represented by Formula (2-1)-Formula (2-13) can be mentioned, for example. In formulas (2-1) to (2-13), R ² and R ³ are each independently an alkyl having 1 to 12 carbons, an alkoxy having 1 to 12 carbons, an alkenyl having 2 to 12 carbons, It is an alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by halogen, or an alkenyl having 2 to 12 carbons in which at least one hydrogen is replaced by halogen.

As a halogen-type liquid crystal compound represented by Formula (3), the compound represented by Formula (3-1) to Formula (3-19) can be mentioned, for example. In formulas (3-1) to (3-19), R ⁴ and R ⁵ each independently represent alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, C2-C12 alkenyloxy, or C1-C12 alkyl in which at least one hydrogen is replaced by halogen.

  The liquid crystal composition α is a halogen-based liquid crystal compound represented by the above formula (1) (hereinafter also referred to as a compound (1)), and a liquid crystal compound represented by the above formula (2) (hereinafter also referred to as a compound (2)) In addition to the compound selected from the halogen-based liquid crystal compounds represented by the above formula (3) (hereinafter also referred to as compound (3)), other liquid crystal compounds, additives and the like are further contained. May be The “other liquid crystal compound” is a liquid crystal compound different from the compound (1), the compound (2) and the compound (3). Such compounds are mixed into the composition for the purpose of further adjusting the properties. Additives include optically active compounds, antioxidants, ultraviolet light absorbers, dyes, antifoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors and the like.

  Next, the main properties of the component compounds (1) to (3) and the main effects of the compounds on the properties of the liquid crystal composition will be described. The main properties of the component compounds are summarized in the following table based on the effects of the present invention. In the symbols in the table, L means large or high, M medium, and S small or low. The symbols L, M, S are classifications based on qualitative comparisons among the component compounds, and 0 (zero) means that the value is almost zero.

  When the component compounds are mixed in the liquid crystal composition, the main effects of the component compounds on the properties of the liquid crystal composition are as follows. The compound (1) raises the dielectric anisotropy. The compound (2) lowers the viscosity or raises the upper limit temperature. The compound (3) raises the dielectric constant in the minor axis direction.

  Preferred combinations of component compounds in the liquid crystal composition α are compound (1), compound (3), compound (1) + compound (2), compound (2) + compound (3), compound (1) + compound (3) Or compound (1) + compound (2) + compound (3). A further preferable combination is compound (1) + compound (2) and compound (2) + compound (3).

  The dielectric anisotropy of the compound (1) is positive, and the dielectric anisotropy of the compound (3) is negative. On the other hand, the dielectric anisotropy of the compound (2) is almost zero, and is used to adjust properties other than the dielectric anisotropy. In order to drive the liquid crystal display element at a low voltage, it is desirable to secure the absolute value of the dielectric anisotropy, and therefore, it is desirable to use the compound (1) + the compound (2) or the compound (2) + the compound (3) A combination is desired. The composition of the compound (1) + the compound (2) has positive dielectric anisotropy, and the composition of the compound (2) + compound (3) has negative dielectric anisotropy.

  In liquid crystal compound α, the preferred proportion of compound (1) is about 10% by weight or more to increase dielectric anisotropy, and about 90% by weight or less to lower the lower limit temperature or to lower the viscosity. is there. A further preferred ratio is in the range of about 15% by weight to about 75% by weight. An especially desirable ratio is in the range of about 20% by weight to about 65% by weight.

  In liquid crystal compound α, the preferred proportion of compound (2) is about 10% by weight or more to raise the upper limit temperature or to lower the viscosity, and about 90% by weight or less to raise the dielectric anisotropy is there. A further preferred ratio is in the range of about 20% by weight to about 85% by weight. An especially desirable ratio is in the range of about 30% by weight to about 80% by weight.

  In the liquid crystal compound α, the preferred proportion of the compound (3) is about 3% by weight or more in order to increase the dielectric anisotropy, and about 30% by weight or less in order to lower the lower limit temperature. A further preferred ratio is in the range of about 3% by weight to about 25% by weight. An especially desirable ratio is in the range of about 5% by weight to about 20% by weight.

Next, preferred embodiments of the component compounds are described.
In formulas (1) to (3), R ^{1 to} R ⁵ , ring A to ring F, Z ^{1 to} Z ⁴ , X ^{1 to} X ² ,
Y ¹ and a to d are as follows.

R ¹ is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons. Desirable R ¹ is alkyl having 1 to 12 carbons in order to increase the stability to ultraviolet light or heat. R ² and R ³ are each independently an alkyl having 1 to 12 carbons, an alkoxy having 1 to 12 carbons, an alkenyl having 2 to 12 carbons, and 1 to 12 carbons in which at least one hydrogen is replaced by a halogen Or an alkenyl having 2 to 12 carbon atoms in which at least one hydrogen is replaced by a halogen. Desirable R ² and R ³ are alkenyl having 2 to 12 carbons to lower the viscosity and alkyl having 1 to 12 carbons to increase the stability. R ⁴ and R ⁵ are each independently alkyl of 1 to 12 carbons, alkoxy of 1 to 12 carbons, alkenyl of 2 to 12 carbons, alkenyloxy of 2 to 12 carbons, or at least one hydrogen It is a C1-C12 alkyl substituted by the halogen. Desirable R ⁴ and R ⁵ are alkyl having 1 to 12 carbons to increase stability, and alkoxy having 1 to 12 carbons to increase dielectric anisotropy. The preferred halogen is fluorine or chlorine, and the more preferred halogen is fluorine.

  Preferred alkyl is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl. Further preferred alkyl is ethyl, propyl, butyl, pentyl or heptyl to lower the viscosity.

  Preferred examples of the alkyl in which at least one hydrogen is replaced by halogen are fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl, 7-fluoroheptyl, or 8 -Fluorooctyl. Further preferred alkyl is 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl or 5-fluoropentyl to lower the threshold voltage.

  Preferred alkoxy is methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy or heptyloxy. More desirable alkoxy is methoxy or ethoxy for decreasing the viscosity.

  Preferred alkenyl is vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl or 5-hexenyl. More preferred alkenyl is vinyl, 1-propenyl, 3-butenyl or 3-pentenyl to reduce viscosity. The preferred configuration of -CH = CH- in these alkenyls depends on the position of the double bond. Trans is preferable in the alkenyl such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl and 3-hexenyl for decreasing the viscosity and the like. Cis is preferable in the alkenyl such as 2-butenyl, 2-pentenyl and 2-hexenyl. In these alkenyls, linear alkenyls are preferable to branched ones.

  Preferred alkenyloxy is vinyloxy, allyloxy, 3-butenyloxy, 3-pentenyloxy or 4-pentenyloxy. More preferred alkenyloxy is allyloxy or 3-butenyloxy to lower the viscosity.

  Preferred examples of the alkenyl in which at least one hydrogen is replaced by halogen are: 2,2-difluorovinyl, 3,3-difluoro-2-propenyl, 4,4-difluoro-3-butenyl, 5,5-difluoro-4 -Pentenyl or 6,6-difluoro-5-hexenyl. Further preferred examples are 2,2-difluorovinyl or 4,4-difluoro-3-butenyl for decreasing the viscosity.

  Ring A is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4- Phenylene, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl. Preferred ring A is 1,4-phenylene or 2-fluoro-1,4-phenylene to increase the optical anisotropy. Ring B and ring C are each independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene. Preferred ring B or ring C is 1,4-cyclohexylene to reduce viscosity, or 1,4-phenylene to increase optical anisotropy. Ring D and ring F are each independently 1,4-cyclohexylene, 1,4-cyclohexylene, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine Or tetrahydropyran-2,5-diyl. Desirable ring D or ring F is 1,4-cyclohexylene to reduce viscosity, tetrahydropyran-2,5-diyl to increase dielectric anisotropy, and to increase optical anisotropy It is 1,4-phenylene. Ring E is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,4, 5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl. Preferred ring E is 2,3-difluoro-1,4-phenylene to increase dielectric anisotropy. The configuration of 1,4-cyclohexylene is preferably trans rather than cis in order to increase the maximum temperature. Tetrahydropyran-2,5-diyl is

Z ¹ is a single bond, ethylene, carbonyloxy or difluoromethyleneoxy. Desirable Z ¹ is a single bond to lower the viscosity, and difluoromethyleneoxy to raise the dielectric anisotropy. Z ² is a single bond, ethylene or carbonyloxy. Preferred Z ² is a single bond to lower the viscosity. Z ³ and Z ⁴ are each independently a single bond, ethylene, carbonyloxy or methyleneoxy. Preferred Z ³ or Z ⁴ is a single bond for decreasing the viscosity, and methyleneoxy for increasing the dielectric anisotropy.

X ¹ and X ² are each independently hydrogen or fluorine. Desirable X ¹ and X ² are fluorine for increasing dielectric anisotropy.

Y ¹ represents fluorine, chlorine, alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by halogen, alkoxy having 1 to 12 carbons in which at least one hydrogen is replaced by halogen, or at least one hydrogen is It is a C2-C12 alkenyloxy substituted by the halogen. Desirable Y ¹ is fluorine to lower the lower limit temperature.

  A preferred example of an alkyl in which at least one hydrogen is replaced by halogen is trifluoromethyl. A preferred example of alkoxy in which at least one hydrogen is replaced by halogen is trifluoromethoxy. A preferred example of alkenyloxy in which at least one hydrogen is replaced by halogen is trifluorovinyloxy.

  a is 1, 2, 3 or 4; Desirable a is 2 to lower the lower limit temperature, and 3 to increase the dielectric anisotropy. b is 1, 2 or 3; Preferred b is 1 to lower the viscosity and 2 or 3 to raise the upper temperature limit. c is 1, 2 or 3, d is 0 or 1, and the sum of c and d is 3 or less. Preferred c is 1 to lower the viscosity and 2 or 3 to raise the upper temperature limit. Desirable d is 0 to lower the viscosity and 1 to lower the lower limit temperature.

In the formulas (1) to (3), when a to c are 2 or more, plural ring A, ring B, ring D, and Z ^{1 to} Z ³ may be the same or different. .

  The compound (1) is a compound having a large dielectric anisotropy. Preferred compounds (1) are the compounds (1-1) to the compounds (1-34). In these compounds, at least one of the compounds (1) is a compound (1-4), a compound (1-12), a compound (1-14), a compound (1-15), a compound (1-17), a compound It is preferable that it is (1-18), a compound (1-23), a compound (1-27), a compound (1-28), or a compound (1-29). At least two of the compounds (1) are a compound (1-12) and a compound (1-15), a compound (1-14) and a compound (1-27), a compound (1-18) and a compound (1-24) And Compound (1-18) and Compound (1-28), Compound (1-24) and Compound (1-28), or a combination of Compound (1-28) and Compound (1-29) .

  The compound (2) is a compound having a small dielectric anisotropy. Preferred compounds (2) are the compounds (2-1) to (2-13). In these compounds, at least one of the compounds (2) is a compound (2-1), a compound (2-3), a compound (2-5), a compound (2-6) or a compound (2-7) Is preferred. It is preferable that at least two of the compounds (2) be a combination of the compound (2-1) and the compound (2-3), or the compound (2-1) and the compound (2-5).

  The compound (3) is a compound having a large negative dielectric anisotropy. Preferred compounds (3) are the compounds (3-1) to the compounds (3-19). In these compounds, at least one of the compounds (3) is a compound (3-1), a compound (3-3), a compound (3-4), a compound (3-6), a compound (3-8) or a compound It is preferable that it is (3-13). At least two of the compounds (3) are the compound (3-1) and the compound (3-6), the compound (3-1) and the compound (3-13), the compound (3-3) and the compound (3-6) , Compound (3-3) and Compound (3-13), Compound (3-4) and Compound (3-6), or a combination of Compound (3-4) and Compound (3-8) .

  Additives that may be added to the liquid crystal composition α include optically active compounds, antioxidants, ultraviolet light absorbers, dyes, antifoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors and the like. An optically active compound is added to the liquid crystal composition α for the purpose of inducing a helical structure of the liquid crystal to give a twist angle. Examples of such compounds are compound (4-1) to compound (4-5) shown below. In the formulae, * represents an asymmetric carbon.

  The preferred proportion of the optically active compound is about 5% by weight or less. A further preferred ratio is in the range of about 0.01% by weight to about 2% by weight.

  After the device has been used for a long time, an antioxidant is added to the liquid crystal composition α in order to maintain a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature. Preferred examples of the antioxidant include the compound (5) shown below. In the formula, z is an integer of 1 to 9.

  In the compound (5), preferred z is 1, 3, 5, 7 or 9. More preferably z is 7. Since the compound (5) in which z is 7 has low volatility, it is effective to maintain a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after using the device for a long time. The preferred proportion of the antioxidant is about 50 ppm or more to obtain this effect, and about 600 ppm or less so as not to lower the upper temperature limit or to raise the lower temperature limit. A further preferred ratio is in the range of about 100 ppm to about 300 ppm.

  Preferred examples of the UV absorbers are benzophenone derivatives, benzoate derivatives, triazole derivatives and the like. Also preferred are light stabilizers such as sterically hindered amines. The preferred proportions of these absorbents and stabilizers are about 50 ppm or more to achieve this effect, and about 10000 ppm or less so as not to lower the upper temperature limit or to raise the lower temperature limit. A further preferred ratio is in the range of about 100 ppm to about 10000 ppm.

  In order to conform to a device of guest host (GH) mode, a dichroic dye such as an azo dye or an anthraquinone dye is added to the liquid crystal composition α. The preferred proportion of dye is in the range of about 0.01% to about 10% by weight. In order to prevent foaming, an antifoam agent such as dimethyl silicone oil, methylphenyl silicone oil or the like is added to the composition. The preferable proportion of the antifoaming agent is about 1 ppm or more to obtain this effect, and about 1000 ppm or less to prevent display defects. A further preferred ratio is in the range of about 1 ppm to about 500 ppm.

  Compounds (1) to (3) which are component compounds can be synthesized by known methods. For example, the compound (1-2) and the compound (1-8) can be synthesized by the method described in JP-A-2-233626. The compound (2-1) is synthesized by the method described in JP-A-59-176221. The compound (3-1) and the compound (3-6) can be synthesized by the method disclosed in JP-A-2-503441. Compounds of formula (5) wherein z is 1 are available from Aldrich (Sigma-Aldrich Corporation). Compounds (5) etc. whose z is 7 can be synthesized by the method described in US Pat. No. 3,660,505.

  Compounds that did not describe the synthesis method include organic syntheses (John Wiley & Sons, Inc), Organic Reactions (John Wiley & Sons, Inc), comprehensive organic syntheses (Comprehensive Organic) It can be synthesized by the method described in the book such as Synthesis, Pergamon Press), New Experimental Chemistry Course (Maruzen). The liquid crystal composition is prepared by a known method from the compound thus obtained. For example, the component compounds are mixed and dissolved together by heating.

  The liquid crystal composition α mainly has a lower limit temperature of about −10 ° C. or lower, an upper limit temperature of about 70 ° C. or higher, and an optical anisotropy in the range of about 0.07 to about 0.20. The element containing the liquid crystal composition α has a large voltage holding ratio. This liquid crystal composition α is suitable for an AM (active matrix) device. This liquid crystal composition α is particularly suitable for transmissive AM devices. A composition having an optical anisotropy in the range of about 0.08 to about 0.25, and further about 0.10 to about 0.10, by controlling the proportions of the component compounds, or by mixing other liquid crystal compounds. Compositions having an optical anisotropy in the range of about 0.30 may be prepared. This composition can be used as a composition having a nematic phase, or as an optically active composition by adding an optically active compound.

Second Embodiment
Next, a second embodiment of the present invention will be described using FIG. In the liquid crystal display element of the present embodiment, as an element capable of achieving high-speed response, an element of the ULH (Uniform Lying Helix) type utilizing the flexoelectric effect particularly found in a cholesteric liquid crystal is known.

  As shown in FIG. 5 (a), as the liquid crystal composition 2a in the liquid crystal inclusion composite fiber 10, a liquid crystal composition β driven in a cholesteric phase having a helical pitch shorter than 1 μm is suitably used. Driven by the fucking electric effect. The liquid crystal molecules 2b are arranged to pivot around the helical axis AX, and when an electric field is applied by the electrodes, the switching operation is performed by tilting the helical axis in the substrate plane.

  As shown in FIG. 5 (b), a plurality of the liquid crystal-containing composite fibers 10 are arrayed in a planar shape, preferably in the height direction (the direction of the front and back sides of the paper) on a substrate (not shown) A body 20 is formed. In a manufacturing method using a conventional alignment film, it was difficult to orient the helical axis of the liquid crystal composition β in a certain direction. In this embodiment, since the liquid crystal inclusion composite fibers 10 are arranged in a plane, the liquid crystal composition 2a can be easily arranged in one direction. Therefore, it is possible to achieve the enlargement (large screen) of the liquid crystal display element of the ULH method.

  Substrates and electrodes (not shown in FIG. 5B) are formed on the upper and lower sides (front and back sides of the sheet of the drawing) of the composite fiber assembly 20, and the electrodes can apply voltage in a direction substantially perpendicular to the substrate. It is configured as a driving electrode.

<Liquid crystal composition β>
Next, the liquid crystal composition β will be described.
The helical pitch of the liquid crystal composition β of the present application is 1 μm or less, preferably less than 500 nm, more preferably less than 400 nm, and most preferably 300 nm or less.
The helical axis of the liquid crystal composition β is preferably parallel to the direction of the fibers, in which case it is preferably driven by an electric field in the direction perpendicular to the helical axis.
The liquid crystal composition β may be a composition comprising a chiral compound, but preferably comprises an achiral component T and a chiral agent.

As the achiral component T, preferably, two mesogens are linked by a spacer, and the spacer contains one or more bimesogenic compounds having at least 3 atoms and an odd number of atoms in the group.
The achiral component T preferably includes a bimesogenic compound represented by the following formula (6).

In formula (6), each R ⁶ independently represents cyano (CN), fluorine, chlorine or any —CH ₂ — in the group being replaced by oxygen, sulfur, —COO—, —OCO— It is also an alkyl having 1 to 10 carbon atoms, provided that oxygen is not adjacent, and in the alkyl, any hydrogen of the group may be replaced by halogen.
MG ⁶ each independently represents a mesogen, Sp is an alkylene having 5 to 40 carbon atoms, and each X ⁶ is independently -CO-O-, -O-CO-, -CH ₂ -O _{-, - O-CH 2 -} , - CF 2 -O -, - O-CF 2 -, - CH 2 -CH 2 -, - C≡C -, - CH (CH 3) -N = CH- or a single It is a bond, preferably a single bond.
In formula (6), R ⁶ , MG ⁶ and X ⁶ may be the same or different.

Chiral Agent The chiral agent that the liquid crystal composition β of the present invention may contain is an optically active compound.
As a chiral agent used for liquid crystal composition (beta) of this invention, the compound with large twisting power (Helical Twisting Power, HTP) is preferable. A compound having a large twisting power can reduce the amount of addition required to obtain a desired pitch, so that an increase in drive voltage can be suppressed, which is advantageous in practical use. Specifically, compounds represented by the compounds (K1) to (K7) are preferable. In compounds (K4) to (K7), binaphthyl and octahydronaphthyl are optically active sites, and chirality of the chiral agent does not matter.

(In the above formula, R ^K is each independently hydrogen, halogen, —C≡N, —N = C = O, —N = C = S or C 1 -C 20 alkyl, and in the said alkyl, At least one -CH ₂ -may be replaced by -O-, -S-, -COO- or -OCO-, and at least one -CH ₂ -CH _{2-in the} alkyl is -CH = CH- , -CF = CF- or -C≡C-, and at least one hydrogen in the alkyl may be replaced by fluorine or chlorine;
A ^K is independently an aromatic 6-8 membered ring, a nonaromatic 3-8 membered ring, or a fused ring having 9 or more carbon atoms, and at least one hydrogen of these rings is It may be replaced by halogen, alkyl having 1 to 3 carbons or haloalkyl, and -CH _2-of the ring may be replaced by -O-, -S- or -NH-, and -CH = is -N = May be replaced by
Y ^K each independently represents hydrogen, halogen, alkyl having 1 to 3 carbon atoms, haloalkyl having 1 to 3 carbon atoms, aromatic 6 to 8 membered ring, non-aromatic 3 to 8 membered ring, or And at least one hydrogen of these rings may be replaced by halogen, alkyl having 1 to 3 carbons or haloalkyl, and -CH _2- in the alkyl is -O-. , -S- or -NH-, and -CH = may be replaced by -N =;
Z ^K is each independently a single bond or an alkylene having 1 to 8 carbon atoms, and at least one —CH ₂ — in the alkylene is —O—, —S—, —COO—, —OCO—, -CSO-, -OCS-, -N = N-, -CH = N- or -N = CH-, and at least one -CH ₂ -CH _{2-in the} alkylene is -CH = CH—, —CF = CF— or —C≡C— may be replaced, and at least one hydrogen in the alkylene may be replaced by halogen;
X ^K each independently represents a single bond, -COO-, -OCO-, -CH ₂ O-, -OCH _2- , -CF ₂ O-, -OCF _2- , or -CH ₂ CH _2- ;
Each mK is independently an integer of 1 to 4. )

  Among these compounds, as chiral agents to be added to the liquid crystal composition, compounds (K4-1) to (K4-6), (K5-1) to (K5-3), (K6-1) to (K6-6) and (K7-1) to (K7-2) are preferable, and the compounds (K4-5), (K5-1) to (K5-3), (K6-5) to (K6-6) are preferable. And (K7-1) to (K7-2) are more preferable.

(Wherein, R ^K is independently alkyl having 3 to 10 carbons or alkoxy having 3 to 10 carbons, and at least one or more -CH ₂ -CH _2- in alkyl or alkoxy is -CH It may be replaced by = CH-.)

  One compound may be used as a chiral agent contained in the liquid crystal composition, or a plurality of compounds may be used.

  The chiral agent is preferably contained in an amount of 1 to 40% by weight, and preferably 1 to 10% by weight, based on the total weight of the liquid crystal composition β of the present invention, in order to make the liquid crystal composition β a desired helical pitch. Is more preferable, and 2 to 8% by weight is particularly preferable.

  As the additives which may be added to the liquid crystal composition β, the additives described in the section of the liquid crystal composition α can be exemplified.

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto. In addition, the measuring method or definition of the physical-property value shown in the Example is shown below.
1) Continuity of Liquid Crystal Composition Containing Halogen-Based Liquid Crystal Compound in Composite Fiber Using a polarizing microscope made by Nikon Corporation, composite fiber is observed in the cross nicol state, and continuity of liquid crystal composition containing halogen-based liquid crystal compound It was confirmed.
2) Alignment state of the liquid crystal composition containing the halogen-based liquid crystal compound in the composite fiber Using a polarizing microscope made by Nikon Corporation, the composite fiber is rotated and observed in the cross nicol state, and the change in the light transmission of the composite fiber is I observed it.
3) Standard outside diameter of composite fiber and standard deviation of outside diameter Using a scanning electron microscope, 50 outside diameters are measured from an image obtained by observing the composite fiber at a magnification of 500 to 5,000 times, Mean values and standard deviations were calculated.

(Liquid Crystal Composition A Used in Examples 1 and 2)
The composition of the liquid crystal composition A is as follows.

Example 1
Viscosity consisting of 10 parts by weight of polyvinyl pyrrolidone (Mw: 1,300,000 Sigma-Aldrich), 36 parts by weight of ethanol (primary; Nacalai Tesque, Inc.), and 54 parts by weight of chloroform (primary; Nacalai Tesque, Inc.) A sheath solution of 360 mPa · s was prepared.
Then, the sheath solution is extruded at a rate of 0.2 mL / hr to a nozzle with an inner diameter of 0.22 mm by a syringe pump and 6.0 mL / hr at a nozzle with an inner diameter of 0.8 mm by a syringe pump. A voltage of 20 kV was applied, and composite fibers were randomly collected on a grounded collector. The distance between the needle and the collector was 23 cm. A polarized light micrograph of the obtained conjugate fiber is shown in FIG.

  As apparent from FIG. 6, the liquid crystal composition in the composite fiber was continuously distributed. In addition, when the composite fiber was rotated and observed, the change in the light transmission amount was confirmed, which suggests that the liquid crystal in the composite fiber is oriented in the perpendicular direction or parallel direction with respect to the fiber axis. The

  In addition, a scanning electron micrograph of the composite fiber is shown in FIG. From FIG. 7, the average outside diameter of the composite fiber obtained was 3.64 μm, the standard deviation of the outside diameter was 0.42 μm, and the CV value of the outside diameter was 12%.

(Example 2)
10 parts by weight of polyvinyl pyrrolidone (Mw: 1,300,000 Sigma-Aldrich), 36 parts by weight of ethanol (primary; Nacalai Tesque, Inc.), 54 parts by weight of chloroform (primary; Nacalai Tesque, Inc.), ammonium acetate A sheath solution having a viscosity of 360 mPa · s, made of 0.1 parts by weight (Nacalai Tesque, Inc.), was prepared. Next, the syringe solution is used to extrude the sheath solution at 0.4 mL / hr at a viscosity of 20 mPa · s at a nozzle with an inner diameter of 0.22 mm and 2.0 mL / hr at a nozzle with an inner diameter of 0.8 mm and 15 kV at the nozzle The composite fiber was randomly collected on a grounded collector. The distance between the needle and the collector was 20 cm. The liquid crystal composition in the obtained composite fiber is continuously distributed, and by rotating the composite fiber, a large difference in the light transmission amount was confirmed. In addition, a scanning electron micrograph of the composite fiber is shown in FIG.

  From FIG. 8, the average outer diameter of the composite fiber obtained was 1.60 μm, the standard deviation of the outer diameter was 0.25 μm, and the CV value of the outer diameter was 16%.

  Next, the composite fibers obtained in Examples 1 and 2 were placed on the substrate shown in FIG. 9 to produce a liquid crystal display element 100. On the substrate 30 of this example, so-called comb-shaped electrodes are disposed, and the electrodes 27 extending from the left side and the electrodes 28 extending from the right side are alternately disposed. Therefore, when there is a potential difference between the electrode 27 and the electrode 28, it is possible to provide a state in which electric fields in two directions, upward and downward, exist. That is, an electric field can be applied in a direction substantially parallel to the substrate 30. The arrangement direction of the composite fiber was generally 45 ° with respect to the linear direction of the comb electrode.

  The liquid crystal display element 100 described above was set in an optical system, and the electro-optical characteristics were measured. A white light source of a polarized light microscope (Eclipse LV100POL manufactured by Nikon Corporation) is used as a light source so that the incident angle to the cell is perpendicular to the cell surface, and the longitudinal direction of the two electrodes 27 and 28 is two polarizing plates. The cells were set in the optical system so as to be 45 ° each. The measurement temperature was normal temperature (about 25 ° C.).

  When a rectangular wave of 60 Hz and 23 V was applied to and removed from the substrate, clear light-dark switching (dark with OFF, bright with ON) was confirmed as shown in FIG. 10, and the transmittance was almost saturated at 23 V. Had

  According to the present invention, in the manufacturing process of the present liquid crystal display element, the process of forming the alignment film can be simplified, and the manufacturing cost can be suppressed. According to the present invention, it is possible to achieve a flexible liquid crystal display element and easily achieve a large screen.

2 core component 2a liquid crystal composition 2b liquid crystal molecule 4 sheath component 4a sheath component forming material 10 liquid crystal inclusion composite fiber (composite fiber)
Reference Signs List 20 composite fiber aggregate 30 substrate 40 binder 100 liquid crystal display element 200 composite fiber manufacturing apparatus 210 double tube nozzle 212 outer nozzle 214 inner nozzle 216 collector 218 power source d outer diameter L inner diameter (core component outer diameter)
L1 sheath solution L2 liquid crystal composition

Claims (16)

At least one substrate,
A composite fiber assembly formed by uniaxially aligning a liquid crystal-containing composite fiber which is a sheath-core type composite fiber disposed on the substrate and having a liquid crystal composition as a core component;
An electrode disposed on the substrate and applying an electric field to the composite fiber assembly based on an external signal;
A liquid crystal display device comprising
The sheath component forming the outer shell of the liquid crystal-containing composite fiber includes a sheath component forming material, and the sheath component forming material and the liquid crystal composition are substantially separated .
The liquid crystal display element whose average outer diameter of the said sheath component is 50 nm or more and 5 micrometers or less .   The liquid crystal display element according to claim 1, wherein the liquid crystal-containing composite fiber is formed by discharging the sheath component-forming material and the liquid crystal composition from different nozzles.   The liquid crystal display element according to claim 1, wherein a voltage applied to drive the liquid crystal composition is 50 V or less.   The liquid crystal display element according to claim 1, wherein the composite fiber assembly includes a binder filled between the liquid crystal inclusion composite fibers.   The liquid crystal display element of any one of Claim 1 to 4 in which the said liquid crystal composition contains a halogen-type liquid crystal compound.   The liquid crystal display device according to any one of claims 1 to 5, wherein the liquid crystal composition exhibits a nematic phase or a chiral nematic phase in which a helical pitch is longer than 10 μm.   The liquid crystal display according to any one of claims 1 to 6, wherein the electrode is a lateral electric field drive electrode capable of applying an electric field to the composite fiber assembly in a direction substantially parallel to the substrate. element.   The liquid crystal display element according to any one of claims 5 to 7, wherein a dielectric anisotropy of the liquid crystal composition is +2 or more or -2 or less. The liquid crystal composition exhibits a cholesteric phase,
The liquid crystal display according to any one of claims 1 to 5, wherein the electrode is a longitudinal electric field drive electrode capable of applying an electric field in a direction substantially perpendicular to the substrate with respect to the composite fiber assembly. element.   The liquid crystal display element according to claim 9, wherein a helical axis of the cholesteric phase is substantially parallel to a fiber axis. The liquid crystal display element according to claim 5, wherein the liquid crystal composition contains at least one liquid crystal compound represented by formula (1).
In the formula (1), R ¹ is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons; ring A is 1,4-cyclohexylene, 1 , 4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, 1,3 -Dioxane-2,5-diyl or tetrahydropyran-2,5-diyl; Z ¹ is a single bond, ethylene, carbonyloxy or difluoromethyleneoxy; and X ¹ and X ² are each independently It is hydrogen or fluorine; Y ¹ is fluorine, chlorine, at least one hydrogen alkyl having 1 to 12 carbon atoms which is replaced by halogen, replace at least one hydrogen with halogen Is alkoxy having 1 to 12 carbon atoms, or at least one hydrogen is alkenyloxy having 2 carbon atoms replaced by halogen 12; a is 1, 2, 3 or 4. When a is 2 or more, a plurality of rings A and Z ¹ may be the same or different. The liquid crystal display element according to claim 5, wherein the liquid crystal composition contains at least one liquid crystal compound represented by Formula (3).
In formula (3), R ⁴ and R ⁵ are each independently an alkyl of 1 to 12 carbons, an alkoxy of 1 to 12 carbons, an alkenyl of 2 to 12 carbons, an alkenyloxy of 2 to 12 carbons, Or an alkyl having 1 to 12 carbon atoms in which at least one hydrogen is replaced by a halogen; ring D and ring F are each independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,2 4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine, or tetrahydropyran-2,5-diyl; ring E is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-di Le, or 7,8-be difluorochroman-2,6-diyl; ^{Z 3} and ^{Z 4} are each independently a single bond, ethylene, carbonyloxy, or methyleneoxy; c is 1, 2, or 3; d is 0 or 1; the sum of c and d is 3 or less. Incidentally, when c is 2 or more, a plurality of ring D, may be different even Z ³ are each identical. The liquid crystal display element according to claim 11, wherein the liquid crystal composition further contains a compound of the formula (2).
In formula (2), R ² and R ³ are each independently alkyl of 1 to 12 carbons, alkoxy of 1 to 12 carbons, alkenyl of 2 to 12 carbons, and at least one hydrogen is replaced by halogen C 1-12 alkyl or C 2-12 alkenyl in which at least one hydrogen is replaced by halogen; ring B and ring C are each independently 1,4-cyclohexylene, 1 4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene; Z ² is a single bond, ethylene or carbonyloxy; b is 1, 2 Or 3 When b is 2 or more, the plurality of rings B and Z ² may be the same or different. The liquid crystal display element according to claim 10, wherein the liquid crystal composition contains at least one compound represented by formula (6).
In formula (6), each R ⁶ independently represents cyano (CN), fluorine, chlorine or any —CH ₂ — in the group being replaced by oxygen, sulfur, —COO— or —OCO— And C 1 -C 10 alkyl which may be substituted with the proviso that oxygen is not adjacent, and in the alkyl, any hydrogen of the group may be replaced by halogen. MG ⁶ each independently represents a mesogen, Sp is an alkylene having 5 to 40 carbon atoms, and each X ⁶ is independently -CO-O-, -O-CO-, -CH ₂ -O _{-, - O-CH 2 -} , - CF 2 -O -, - O-CF 2 -, - CH 2 -CH 2 -, - C≡C -, - CH (CH 3) -N = CH- or a single It is a bond.   The liquid crystal display element according to any one of claims 1 to 14, wherein an average outer diameter of the core component of the conjugate fiber is 10 nm or more and 4.0 μm or less.   The liquid crystal display element according to any one of claims 1 to 15, wherein the thickness of the sheath component is 0.1 μm or more and 1.0 μm or less.