JP2002303891A - Manufacturing method for liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a liquid crystal display element having high contrast, excellent reliability at high temperature and excellent liquid crystal alignment uniformity, in a polymer stabilized ferroelectric liquid crystal display element wherein halftone display can be achieved. SOLUTION: The manufacturing method for the liquid crystal display element, having a stage for polymerizing liquid crystalline monomers is characterized in that a ferroelectric liquid crystal composition having the phase series of chiral smectic C phase-smectic A phase-chiral nematic phase or chiral smectic C phase-chiral nematic phase, a multifunctional liquid crystalline monomer having the phase series of smectic phase having <=40 deg.C lower limit temperature- nematic phase and a liquid crystalline mixture having the phase series of chiral smectic C phase-smectic A phase-chiral nematic phase or chiral smectic C phase- chiral nematic phase are used and UV emission temperature is controlled to <=80 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for manufacturing a ferroelectric liquid crystal display device.

[0002]

2. Description of the Related Art A liquid crystal display device using a ferroelectric liquid crystal proposed by Clark and Lagerwol (Japanese Patent Laid-Open No. 56-1072).
No. 16) has bistability and has a fast response to a change in an electric field, and thus is expected to be applied as a large-screen and high-definition liquid crystal display device. However, since it has bistability, there is a problem that it is difficult to display a halftone.

As a technique for solving this problem, we have disclosed in
No. 11-21554, Ferroelectric liquid crystal and monofunctional liquid crystal (meta)
After injecting a liquid crystal composition containing an acrylate monomer into a liquid crystal cell, a DC voltage is applied to the composition at a temperature at which the composition exhibits a chiral smectic C phase, and the composition is aligned in one direction. Irradiates with ultraviolet light,
A polymer-stabilized ferroelectric liquid crystal device obtained by polymerizing a liquid crystalline (meth) acrylate monomer was proposed. In this device, the bistability of the ferroelectric liquid crystal is lost, so that a halftone display is possible. The orientation direction of the liquid crystal molecules when no voltage is applied to this liquid crystal display element is at a certain angle from the easy axis direction of the alignment film to the direction determined by the polarity of the DC voltage applied during ultraviolet irradiation.
(This angle is defined as the memory angle). When a DC voltage having a polarity different from that of the DC voltage applied during the ultraviolet irradiation is applied to the device, the intensity is increased in the direction opposite to the memory angle with respect to the easy axis of the alignment film in proportion to the absolute value of the DC voltage. The orientation direction of the dielectric liquid crystal is inclined. If no voltage is applied, the ferroelectric liquid crystals are again arranged so as to form a memory angle with respect to the easy axis of the alignment film. On the other hand, when a DC voltage of the same polarity as the DC voltage applied at the time of ultraviolet irradiation is applied, the ferroelectric liquid crystal is slightly inclined at an angle larger than the memory angle with respect to the easy axis direction of the alignment film. Array. The response of the ferroelectric liquid crystal when a DC voltage of the same polarity as the DC voltage applied during such UV irradiation is applied is a liquid crystal display with a polarizing film set so that the memory angle matches the transmission axis. In the case of the element, there is a problem that it becomes an obstacle to obtain a display with high contrast. In addition, although the device using such a monofunctional liquid crystalline (meth) acrylate monomer has a feature that a good halftone display is possible,
There was a problem that the polymer obtained by polymerization of the monofunctional liquid crystalline (meth) acrylate monomer did not have good heat resistance, and as a result, the device had poor reliability at high temperatures.

A polymer-stabilized ferroelectric liquid crystal display device using a polyfunctional liquid crystalline monomer which gives a polymer having better heat resistance than a monofunctional liquid crystalline (meth) acrylate monomer is disclosed in
It is disclosed in JP-A-6-194635. However, many polyfunctional liquid crystalline monomers have a high liquid crystallinity temperature as high as 80 ° C. or higher.Therefore, it is necessary to increase the temperature before the irradiation of ultraviolet rays for preparing a polymer stabilized liquid crystal element. As a result, there is a problem that undesirable thermal polymerization is induced, and the uniformity of liquid crystal alignment is deteriorated.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polymer-stabilized ferroelectric liquid crystal display device capable of halftone display with high contrast, excellent reliability at high temperatures, and uniform liquid crystal alignment. An object of the present invention is to provide a method for manufacturing a liquid crystal display element having excellent properties.

[0006]

As a result of a detailed study to solve the above-mentioned problems, in order to increase the contrast, a polyfunctional liquid-crystalline monomer was used as the liquid-crystalline monomer, and the overlap of the liquid-crystalline monomer was increased. It is important to introduce a strong three-dimensional cross-linking structure into the coalescing, so that the ferroelectric liquid crystal does not respond even if a DC voltage of the same polarity as the DC voltage applied during ultraviolet irradiation is applied, In addition, in order to ensure the reliability of the liquid crystal display element at high temperatures, it is necessary to use a polyfunctional liquid crystalline monomer as the liquid crystalline monomer,
In order to ensure the uniformity of the orientation of the liquid crystal display device, use a polyfunctional liquid crystalline monomer having a smectic-nematic phase series and having a minimum temperature of the smectic phase of 40 ° C. or less, and a ferroelectric property. It is important to ensure good compatibility with the liquid crystal composition, and it is important to adjust the temperature at the time of UV irradiation to 80 ° C or less to avoid the induction of undesirable thermal polymerization during UV irradiation. Was found. Furthermore, they found that a compound having two or more alkylene spacer portions, particularly a compound having three alkylene spacer portions was preferable as a chemical structure with the polyfunctional liquid crystal monomer, and completed the present invention. That is, in the present invention, a liquid crystal mixture containing a ferroelectric liquid crystal composition and a polyfunctional liquid crystal monomer is interposed between two substrates at least one of which has transparency, and the interposed liquid crystal mixture is chiral. A method for manufacturing a liquid crystal display device, comprising: irradiating a liquid crystalline mixture with ultraviolet rays while or after aligning in a state showing a smectic C phase to polymerize a liquid crystalline monomer. The substance has a phase sequence of chiral smectic C-smectic A-chiral nematic or chiral smectic C-chiral nematic, and the polyfunctional liquid crystalline monomer is smectic-
Those having a nematic phase series and having a minimum temperature of the smectic phase of 40 ° C. or lower, and those in which the liquid crystalline mixture has a chiral smectic C-smectic A-chiral nematic or chiral smectic C-chiral nematic phase series. Provided is a method for manufacturing a liquid crystal display element, wherein the method is used and the temperature at the time of irradiating ultraviolet rays is controlled to 80 ° C. or lower.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.

The ferroelectric liquid crystal composition used in the present invention can be used without any particular limitation as long as it is generally recognized as a ferroelectric liquid crystal composition in this technical field, but chiral smectic C-smectic can be used. Those having a phase sequence of A-chiral nematic or chiral smectic C-chiral nematic are preferred. The lower limit temperature of the chiral smectic C phase is preferably -10 ° C or lower, more preferably -20 ° C or lower, and particularly preferably -30 ° C or lower. The maximum temperature of the chiral smectic C phase is preferably 40 ° C. or higher,
50 ° C or higher is more preferable, and 60 ° C or higher is particularly preferable.

The polyfunctional liquid crystalline monomer used in the present invention has two or more polymerizable functional groups in a molecule and has a smectic phase-nematic phase sequence.
If the lower limit temperature of the smectic phase is 40 ° C. or lower, it can be used without any particular limitation. However, the lower limit temperature of the smectic phase is more preferably 35 ° C. or lower, and particularly preferably 25 ° C. or lower. The polyfunctional liquid crystalline monomer may be used alone or as a composition as long as the conditions of the lower limit temperature of the phase series and the smectic phase are satisfied. As the smectic phase, a smectic C phase or a smectic A phase is preferable. The polymerizable functional group, acryloyloxy group, methacryloyloxy group, an acrylamide group, a methacrylamide group, an epoxy group, a vinyl group, a vinyloxy group, an ethynyl group, a mercapto group, a maleimide _{group, ClCH = CHCONH-, CH 2 =} CCl- , CHCl = CH-, RCH = CH
COO- (R represents chlorine, fluorine, or a hydrocarbon group having 1 to 10 carbon atoms), among which an acryloyloxy group, a methacryloyloxy group, an epoxy group, a mercapto group, and a vinyloxy group are preferable. A methacryloyloxy group and an acryloyloxy group are particularly preferred, and an acryloyloxy group is most preferred. The molecular structure of the polyfunctional liquid crystalline monomer has at least two liquid crystal skeletons, polymerizable functional groups, and at least two flexible groups that link the liquid crystal skeleton and the polymerizable functional groups, each having two or more ring structures. Are preferred, and those having three flexible groups are more preferred. As a flexible group,-(CH ₂ ) _n-
An alkylene spacer group represented by (n represents an integer) or a siloxane spacer group represented by-(Si (CH ₂ ) ₂ -O) _n- (n represents an integer) can be raised. Preferably, alkylene spacer groups are preferred. The bonding portion between these flexible groups and the liquid crystal skeleton or polymerizable functional group has -O
A bond such as-, -COO- or -CO- may be present. The liquid crystal skeleton can be used without particular limitation as long as it is generally recognized as a liquid crystal skeleton (mesogen) in this technical field, but a liquid crystal skeleton having at least two or more ring structures is preferable. The ring that can be used as the ring structure is benzene, pyridine, pyrazine, pyridazine, pyrimidine, 1,2,4-triazine, 1,3,5-triazine, tetrazine, dihydrooxazine, cyclohexane, cyclohexene, cyclohexadiene, cyclohexanone, piperidine , Piperazine, tetrahydropyran, dioxane, tetrahydrothiopyran, dithiane, oxathiane, dioxaborinane, naphthalene, dioxanaphthalene, tetrahydronaphthalene, quinoline, coumarin, quinoxaline, decahydronaphthalene, indane, benzoxazole, benzothiazole, phenanthrene, dihydrophenanth Len, perhydrophenanthrene, dioxaperhydrophenanthrene, fluorene, fluorenone, cycloheptane, cycloheptatrienone Cholestenoic, bicyclo [2.2.2] octane and bicyclo [2.2.2] octene, 1,5-dioxaspiro (5.5) undecane, 1,5-Jichiasupiro (5.5)
Examples include undecane, triphenylene, tolcene, porphyrin, and phthalocyanine. Among them, benzene, cyclohexane, phenanthrene, naphthalene, tetrahydronaphthalene, and decahydronaphthalene are preferable. These rings are an alkyl group having 1 to 7 carbon atoms, an alkoxy group, an alkanoyl group, or a cyano group,
One or more halogen atoms may be substituted. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, and an n-
A butyl group is preferred, and a methyl group and an ethyl group are particularly preferred. As the alkoxy group, a methoxy group, an ethoxy group,
A propoxy group and a butoxy group are preferable, an alkanoyl group is preferably an acetyl group, a propionyl group, and a butyroyl group, and a halogen atom is preferably a fluorine atom, a bromine atom and a chlorine atom, and particularly preferably a fluorine atom and a chlorine atom. Further, a monofunctional liquid crystalline monomer may be added in addition to the polyfunctional liquid crystalline monomer. The monofunctional liquid crystalline monomer may be any one that is recognized as a monofunctional liquid crystalline monomer in this technical field, but the amount added is determined by the mass ratio of the polyfunctional liquid crystalline monomer to the monofunctional liquid crystalline monomer.
It is preferable that the ratio be in the range of 1: 9 to 10: 0. The mass ratio of polyfunctional liquid crystal monomer to monofunctional liquid crystal monomer is
If the ratio of the polyfunctional liquid crystalline monomer is lower than 1: 9, there is a risk that the stability of the obtained liquid crystal display device at high temperatures may not be good.

[0010] The ferroelectric liquid crystal composition and the liquid crystal mixture containing a polyfunctional liquid crystal monomer are chiral smectic C-
Those having a phase series of smectic A-chiral nematic or chiral smectic C-chiral nematic phase are preferred. The minimum temperature of chiral smectic C phase is -10
° C or lower is preferable, -20 ° C or lower is more preferable, -30 ° C
The following are particularly preferred. The maximum temperature of the chiral smectic C phase is preferably 40 ° C or higher, more preferably 50 ° C or higher,
Particularly preferred is 60 ° C. or higher. The concentration of the polyfunctional liquid crystal monomer in the liquid crystal mixture is preferably 0.1 to 10% by mass,
0.5 to 7% by mass is more preferable, and 1 to 5% by mass is particularly preferable. When the concentration of the polyfunctional liquid crystalline monomer is lower than 0.1% by mass, the effect of stabilizing the alignment is hardly obtained, and the contrast is reduced. When the concentration is higher than 10% by mass, the driving voltage of the ferroelectric liquid crystal increases. A photopolymerization initiator may be added to the liquid crystalline mixture for the purpose of rapidly performing ultraviolet polymerization in the chiral smectic C phase. The photopolymerization initiator that can be used here can be selected from, for example, known benzoin ethers, benzophenones, acetophenones, benzyl ketals, and acylphosphines. The amount added is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less, based on the polyfunctional liquid crystalline monomer contained in the liquid crystalline mixture. Further, a stabilizer may be added for the purpose of improving the storage stability of the liquid crystalline mixture. As the stabilizer that can be used here, for example, a known hydroquinone, a hydroquinone monoalkyl ether, a tert-butyl catechol, a nitroso compound, or the like can be used. The addition amount is preferably 1% by mass or less, more preferably 0.5% by mass or less, more preferably 0.05% by mass, based on the polyfunctional liquid crystalline monomer contained in the liquid crystalline mixture.
% Is particularly preferred.

The two substrates used in the liquid crystal display device of the present invention have an electrode layer, and at least one of them needs to have transparency. Examples of the transparent substrate include glass, polycarbonate, and polyester. Examples of the non-transparent substrate include a silicon substrate on which an active element is formed for each pixel. Those in which a color filter layer is provided on these substrates can also be suitably used. Further, it is preferable to use a substrate on which an active element such as a transistor is formed for each pixel as one of the two substrates. The substrate surface is preferably subjected to an orientation treatment. As the alignment treatment, a method of forming an organic thin film such as polyimide, and further performing a rubbing treatment,
Further, a method of irradiating polarized ultraviolet light to an organic thin film such as a polyvinyl cinnamate thin film can be used. The direction in which the long axes of liquid crystal molecules are aligned on the substrate by the alignment process
The (easy axis) is preferably set to be parallel (parallel) or antiparallel (anti-parallel) between the two substrates. The distance between the two substrates, that is, the thickness of the liquid crystal layer depends on the ferroelectric liquid crystal material used and the anisotropy of the refractive index of the polyfunctional liquid crystal monomer, but is preferably 1 to 10 μm. , 1.5 to 7 μm is more preferable, and 2 to
6 μm is particularly preferred. If the thickness of the liquid crystal layer is smaller than 1 μm, a sufficient amount of optical switching cannot be obtained, and the contrast tends to be reduced.If the thickness of the liquid crystal layer is larger than 10 μm, a uniform alignment is formed inside. May not be available.

In order to interpose a liquid crystal mixture containing a ferroelectric liquid crystal composition and a polyfunctional liquid crystal monomer between two substrates, a vacuum injection method used in this technical field is used. preferable. At this time, it is preferable to inject at a temperature at which the liquid crystalline mixture becomes an isotropic liquid phase or a temperature at which it becomes a chiral nematic phase. After the completion of the injection, it is necessary to maintain the temperature at which the liquid crystalline mixture becomes a chiral smectic C phase and to orient the liquid crystal mixture.
As described above, it is particularly preferable to achieve this by applying a DC voltage of 15 V or more. In order to achieve a good alignment state, after injecting the liquid crystalline mixture between the two substrates at a temperature at which the liquid crystalline mixture becomes an isotropic liquid phase, the application of a DC voltage is started, and a chiral nematic phase or a smectic A phase is formed. It is preferable that the temperature be gradually lowered via the above and the DC voltage be continuously applied until the phase becomes a chiral smectic C phase. As the alignment state, it is preferable that the liquid crystal molecules are aligned in one direction (uniaxial) with good uniformity. Thereafter, when polymerizing the polyfunctional liquid crystal monomer using ultraviolet light or an electron beam, it is not necessary to apply a DC voltage, or the DC voltage may be applied. It is natural that the temperature at which the ultraviolet ray or the electron beam is irradiated needs to be a temperature at which the liquid crystalline mixture exhibits a chiral smectic C phase, as long as the temperature is within a temperature range in which the chiral smectic C phase is maintained. It is preferable to keep the temperature as low as possible. Specifically, it is preferably 80 ° C or lower, more preferably 60 ° C or lower, more preferably 40 ° C or lower, particularly preferably 30 ° C or lower, and most preferably room temperature. The irradiation amount of the ultraviolet ray or the electron beam depends on the concentration of the liquid crystalline mixture and the photopolymerization initiator used, but is from 50 to 50%.
A range of 10,000 mJ / cm ² is preferred. If the irradiation amount of ultraviolet rays or electron beams is less than 50 mJ / cm ² , the liquid crystalline monomer will not be sufficiently cured, and the change with time after manufacture will be large. If it is more than 10,000 mJ / cm ² , The mixture tends to deteriorate.

In the liquid crystal display device obtained by the manufacturing method of the present invention, it is preferable to provide a step of bonding two polarizing films from the viewpoint of enhancing the contrast of the liquid crystal display device. The transmission axis of one of the polarizing films is aligned with the alignment direction of the liquid crystal molecules when no voltage is applied to the obtained liquid crystal display element, and the transmission axis of the other polarizing film is It is preferable to set the orientation of the liquid crystal molecules to be the same or orthogonal. With such a structure, a liquid crystal display device having high reliability at high temperature and having a contrast of 50 or more, more preferably 100 or more, and particularly preferably 200 or more can be manufactured.

[0014]

The present invention will be described below in more detail with reference to Examples of the present invention. However, the invention is not limited to these examples.

(Example 1) On a glass substrate having an ITO transparent electrode layer, a polyimide film "RN-1199" (manufactured by Nissan Chemical Industries, Ltd.) was applied for about 0.03.
After being formed to a thickness of μm, a rubbing treatment was performed to obtain a glass substrate with a polyimide alignment film. The two glass substrates provided with a polyimide alignment film thus obtained were opposed to each other at an interval of 2 μm such that the surface on which the alignment film was formed was on the inner side, to prepare a liquid crystal cell. At this time, 2 of the liquid crystal cell
The rubbing direction of the substrates was set to be in an anti-parallel orientation. Next, it has four benzene rings, has two acryloyloxy groups as polymerizable functional groups, has three alkylene spacer parts as flexible groups, and has a smectic A phase-nematic phase as a phase series. 1 part by mass of a liquid crystalline diacrylate monomer “UCL-010” (manufactured by Dainippon Ink and Chemicals, Inc.) exhibiting a smectic A phase at 36 ° C., and a ferroelectric liquid crystal composition “R2301” (manufactured by Clariant, Chiral Smectic) C-chiral nematic phase transition temperature 66
° C, chiral nematic-isotropic liquid phase transition temperature 87-90
° C. The present ferroelectric liquid crystal composition has no smectic A phase. ) 99 parts by mass and a photopolymerization initiator `` Irgacure 651 ''
A liquid crystalline mixture (A) comprising 0.01 parts by mass (manufactured by Ciba Specialty Chemicals) was prepared. This liquid crystalline mixture (A)
The liquid crystalline mixture was injected into the isotropic liquid phase while maintaining the temperature at 100 ° C., and the temperature was lowered to 25 ° C. while a DC voltage of 5 V was applied, so that the liquid crystalline mixture exhibited a chiral smectic C phase. Next, the application of the DC voltage was stopped, and ultraviolet light having a center wavelength of 365 nm and an intensity of ² mW / cm ² (the value after passing through the cell) was applied at 25 ° C.
Irradiation for 0 seconds, liquid crystalline diacrylate monomer "UCL-010"
Was light cured. Observation of the liquid crystal cell confirmed that a uniform alignment state was obtained. On one surface of this liquid crystal cell, the transmission axis is aligned with the alignment direction of the liquid crystal molecules when no voltage is applied to the obtained liquid crystal cell, and on the other surface, the transmission axis is aligned with the alignment of the liquid crystal molecules. A liquid crystal display device was produced by laminating in a direction perpendicular to the direction. FIG. 1 shows the electro-optical characteristics of the liquid crystal display element manufactured as described above. As can be seen, when a DC voltage having the same polarity as the voltage applied before the irradiation with the ultraviolet light is applied, the light transmittance is extremely small, and a DC voltage with a polarity different from the voltage applied before the irradiation with the ultraviolet light is used. In this case, the light transmittance increased smoothly as the voltage was gradually increased. From this, it was confirmed that the obtained liquid crystal display device was capable of displaying good halftones. In addition, the obtained liquid crystal display element has a high display contrast,
Characteristics have been stable for more than a month. Further, in the liquid crystal display element heated to the isotropic liquid phase and returned to room temperature, the liquid crystal was uniformly aligned as before the heating, and there was no problem in reliability at high temperatures. In addition, the response speed from the no voltage application state to the voltage application state and from the voltage application state to the no voltage application state was 1 ms or less, and it was confirmed that extremely high-speed switching was possible.

(Example 2) The same liquid crystal cell as that manufactured in Example 1 was prepared. Next, 1 part by mass of a liquid crystalline diacrylate monomer `` UCL-010 '' (manufactured by Dainippon Ink and Chemicals, Inc.)
Ferroelectric liquid crystal composition “CS1014” (manufactured by Chisso Corporation, chiral smectic C-smectic A phase transition temperature 55 ° C., smectic A-chiral nematic phase transition temperature 69 ° C., chiral nematic-isotropic liquid phase transition temperature 81 ° C.) A liquid crystalline mixture (B) comprising 99 parts by mass and 0.01 parts by mass of a photopolymerization initiator “Irgacure 651” (manufactured by Ciba Specialty Chemicals) was prepared. After injecting this liquid crystalline mixture (B) in an isotropic liquid phase while maintaining it at 90 ° C., it was cooled to room temperature (25 ° C.) to bring the liquid crystalline mixture (B) into a state exhibiting a chiral smectic C phase. . Next, at 25 ° C., while applying a DC voltage of 5 V, the liquid crystal diacrylate monomer “UCL-010” was irradiated with ultraviolet light having a central wavelength of 365 nm and an intensity of ² mW / cm ² (value after passing through the cell) for 60 seconds. Was light cured. After the application of the DC voltage was stopped, the liquid crystal cell was observed, and it was confirmed that a uniform alignment state was obtained. On one surface of this liquid crystal cell, the transmission axis is aligned with the alignment direction of the liquid crystal molecules when no voltage is applied to the obtained liquid crystal cell, and on the other surface, the transmission axis is aligned with the alignment of the liquid crystal molecules. A liquid crystal display device was produced by laminating in a direction perpendicular to the direction. The liquid crystal display device obtained in this way was capable of displaying a good halftone display similarly to the liquid crystal display device obtained in Example 1. The obtained liquid crystal display device had high display contrast and stable characteristics for one month or more. In addition, the liquid crystal display element heated to the isotropic liquid phase and returned to room temperature has the liquid crystal uniformly aligned as before the heating,
There was no problem with the reliability at high temperatures. In addition, the response speed from the no voltage application state to the voltage application state and from the voltage application state to the no voltage application state was 1 ms or less, and it was confirmed that extremely high-speed switching was possible.

(Comparative Example 1) Instead of the liquid crystalline diacrylate monomer “UCL-010”, it has two benzene rings as a liquid crystal skeleton, has one acryloyloxy group as a polymerizable functional group, and has a temperature of 35 ° C. A liquid crystal display device was produced in the same manner as in Example 1 except that a liquid crystalline monoacrylate monomer (C) exhibiting a smectic phase was used. The obtained liquid crystal display element had a uniform liquid crystal alignment state and was capable of halftone display, but when a DC voltage having the same polarity as the DC voltage applied during ultraviolet irradiation was applied, Light leakage occurred, and as a result, high contrast was not obtained.

[0018]

According to the method of manufacturing a liquid crystal display device of the present invention, a polymer-stabilized ferroelectric liquid crystal display device having a high contrast of 50 or more and capable of displaying a halftone can be manufactured. .

[Brief description of the drawings]

FIG. 1 is a diagram showing electro-optical characteristics (horizontal axis: applied voltage, vertical axis: light transmission amount (arbitrary unit)) of a liquid crystal display element manufactured by a manufacturing method of the present invention in Example 1.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Miki Tanaka 1-29, Tamaicho, Toyonaka-shi, Osaka (72) Inventor Haruyoshi Takatsu 3-6-27, Nakahara, Higashiyamato-shi, Tokyo (72) Inventor Hiroshi Hasebe 4-12-8-107 Midorioka, Ageo-shi, Saitama F-term (reference) 2H088 GA04 GA17 HA03 MA13 2H090 MB14 4H027 BA11 BB09 BB11 BD12 BD20 BE05

Claims (5)

[Claims] 1. A liquid crystal mixture containing a ferroelectric liquid crystal composition and a polyfunctional liquid crystal monomer is interposed between two substrates, at least one of which has transparency, and the interposed liquid crystal mixture is chiral smectic. A method for manufacturing a liquid crystal display device, comprising irradiating a liquid crystalline mixture with ultraviolet light while or after aligning in a state showing a C phase to polymerize a liquid crystalline monomer, comprising the steps of: Has a chiral smectic C-smectic A-chiral nematic, or a chiral smectic C-chiral nematic phase sequence, the polyfunctional liquid crystalline monomer has a smectic-nematic phase sequence, and the lower limit temperature of the smectic phase is 40 ° C. A liquid crystalline mixture having a chiral smectic C-smectic A-chiral nematic or Method of manufacturing a liquid crystal display element characterized by chiral smectic C- use those having a phase sequence of chiral nematic, and to control the temperature to 80 ° C. or less when irradiated with ultraviolet light. 2. A polyfunctional liquid crystal monomer having two or more ring structures, a liquid crystal skeleton, an alkylene spacer portion, two or more polymerizable functional groups, and an alkylene spacer portion. 2. The method for manufacturing a liquid crystal display device according to claim 1, wherein at least two are provided. 3. The method according to claim 2, comprising three alkylene spacer portions. 4. The method according to claim 2, wherein the polymerizable functional group is a (meth) acryloyloxy group. 5. The method according to claim 1, wherein the means for orienting the liquid crystalline mixture in one direction while exhibiting a chiral smectic C phase is application of a DC voltage of 5 V or more. Method for manufacturing a liquid crystal display element.