JP3383921B2 - Liquid crystal device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal encapsulating thin film which does not use a polarizing plate, and more specifically, it can electrically control the blocking and transmission of a visual field, and particularly, it can be used for building windows and show windows. Is used as a screen to block the field of view,
Further, by displaying characters or figures and electrically switching the display with high-speed response, a decorative display board such as an advertising board, a clock, a display device of a calculator, or a display device requiring a bright screen, for example, The present invention relates to a liquid crystal device used as a display device of a computer terminal or a display device of a projection.

[0002]

2. Description of the Related Art As a method for producing a liquid crystal device having a bright and good contrast without using a polarizing plate or an alignment treatment, a method is known in which liquid crystal droplets are dispersed in a polymer and the polymer is formed into a film.

Further, as a technique for enabling low voltage drivability, which is an important characteristic required for practical use of a liquid crystal display device, higher contrast, and time-division drivability, Japanese Patent Laid-Open Publication No. Sho 63-63 is known.
-240460 discloses a liquid crystal device having a structure in which a transparent solid substance is distributed in a three-dimensional network in a continuous layer of a liquid crystal material.

Such a liquid crystal device is used in a so-called normal mode in which light is clouded due to light scattering when no voltage is applied and light is transmitted when a voltage is applied.

However, in the liquid crystal device having the above-mentioned structure, it is difficult to manufacture a liquid crystal device which transmits light when no voltage is applied and scatters light when voltage is applied, which is driven in a so-called reverse mode.

[0006] As a technology of a liquid crystal display device that enables driving in the reverse mode, Young (Yang) et al. [ALCOM SYMPOSIUM Volume 1 (1991)] describes two transparent films having an alignment film on an electrode layer. Between the substrates, gel-like 4,
A liquid crystal device in which a cholesteric liquid crystal is dispersed in a polymer of 4′-bisacryloylbiphenyl has been reported.

[0007]

However, although the above liquid crystal device achieves the reverse mode drive, it has a high drive voltage and does not have a low drive voltage characteristic which is important in the practical application of the display liquid crystal device. . .

Further, the driving voltage in the normal mode of the above liquid crystal device is high, and there is a large hysteresis phenomenon in which the electro-optical characteristics have different transmittances when the voltage rises and when the voltage falls. This causes a margin for time division drive. It was extremely problematic in lowering the gradation display.

The problem to be solved by the present invention is to provide a liquid crystal device in which the driving voltage in the normal mode and the reverse mode is lowered and the hysteresis width is small.

[0010]

In order to solve the above problems, the inventors of the present invention have made earnest studies on the liquid crystal material in the light control layer, and as a result, the driving voltage in the normal mode and the reverse mode is low and the hysteresis width is small. We have made a small liquid crystal device.

That is, in order to solve the above problems, the present invention provides a photopolymerizable composition and a general formula (1).

[0012]

[Chemical 2]

(Wherein R ¹ represents an alkyl group having 1 to 12 carbon atoms, an alkoxyl group, an alkenyl group having 2 to 12 carbon atoms or an alkenyloxy group, and ring A and ring B
Are each independently a 1,4-phenylene group optionally substituted by a fluorine atom or a methyl group, trans-
It represents a 1,4-cyclohexylene group, a pyrimidine-2,5-diyl group or a pyridine-2,5-diyl group, and the C ring may be substituted with a halogen atom or an alkyl group having 1 to 12 carbon atoms. represents a phenyl group, Y is a single bond, -COO -, - OCO -, - CH 2 CH 2 -, -
C≡C-, —CH ₂ O— or —OCH ₂ —, n represents 0 or 1, and * represents an optically active center. ) A liquid crystal device material comprising a liquid crystal material containing a compound represented by the formula (2), and further, two substrates having at least one having an electrode layer having transparency, and a substrate supported between the substrates. A light-scattering liquid crystal device having a light layer, wherein the light control layer comprises a transparent solid substance and the above liquid crystal material, wherein the transparent solid substance is obtained by polymerizing the above photopolymerizable composition. A liquid crystal device characterized by the above.

Further, since the compound represented by the general formula (1) in the present invention can obtain an effective light scattering property even if added in a small amount to the liquid crystal composition, a liquid crystal device having high contrast can be provided. .

The substrate used in the present invention may be a rigid material such as glass or metal, or a flexible material such as a plastic film. The two substrates are opposed to each other and are separated by an appropriate distance.

At least one of them has transparency, but complete transparency is not essential. If the liquid crystal device is used to act on light passing from one side of the device to the other, both substrates will be provided with appropriate transparency.

On this substrate, appropriate transparent or opaque electrodes may be arranged entirely or partially on the substrate depending on the purpose.

When the liquid crystal device of the present invention is used in a display device of a computer terminal, a display device of a projection or the like, it is preferable to provide an active element on the electrode layer.

An alignment film made of polyimide or the like may be arranged on the entire surface or a part of the substrate. It should be noted that a spacer for holding a space can be usually interposed between the two substrates, as in a known liquid crystal device.

As the spacer, for example, Mylar,
Alumina, rod-type glass fiber, glass beads, polymer beads, and other various liquid crystal cells can be used.

As the liquid crystal material used in the present invention, a liquid crystal material other than the compound represented by the general formula (I) (hereinafter referred to as other liquid crystal material) can be used in combination. Any other liquid crystal material may be used as long as it is generally recognized as a liquid crystal material in this technical field, and a compound having a positive dielectric anisotropy is preferable. In order to optimize the performance of the liquid crystal material used in the present invention, it is preferable to use a chiral nematic liquid crystal or a cholesteric liquid crystal in combination, but a chiral smectic liquid crystal or a chiral compound other than the compound of the general formula (1) is used as the liquid crystal material. It may be contained appropriately.

The helical pitch of the liquid crystal material used in the present invention is particularly preferably in the range of 0.5 to 5 μm in order to obtain sufficient contrast between opacity and transparency due to light scattering.

Other liquid crystal materials include, for example, 4-
Substituted benzoic acid 4'-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid 4'-substituted phenyl ester,
4-Substituted cyclohexanecarboxylic acid 4'-substituted biphenyl ester, 4- (4-substituted cyclohexanecarbonyloxy) benzoic acid 4'-substituted phenyl ester, 4-
(4-Substituted cyclohexyl) benzoic acid 4'-substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid 4'-substituted cyclohexyl ester, 4-substituted 4'-substituted biphenyl, 4-substituted phenyl 4'-substituted cyclohexane , 4-substituted 4 ″ -substituted terphenyl, 4-substituted biphenyl 4′-substituted cyclohexane, 2- (4-substituted phenyl) -5-substituted pyridine, cholesterol derivative and the like.

The transparent solid substance in the light control layer has a fibrous or particulate dispersion, a film-like dispersion of a liquid crystal material in the form of droplets, or a three-dimensional network structure. Although it may be one, a gel is preferable.

Further, the liquid crystal material preferably forms a continuous layer, which is essential for forming a disordered state of liquid crystal molecules to form an optical boundary surface and to express light scattering.

The content of the photopolymerizable composition used in the present invention can be adjusted according to the purpose of use, but in order to obtain sufficient contrast between opacity and transparency due to light scattering. , 0.1 to 7% by weight in the light control layer forming material
The content is preferably in the range of 0.1 to 5% by weight, and particularly preferably 0.1 to 5% by weight.

Further, in order to control the structure of the transparent solid substance according to the purpose, a photocurable polymerizable composition containing a polymer-forming monomer or oligomer is preferable.

Examples of the polymer-forming monomer that forms the transparent solid substance include styrene, chlorostyrene,
α-methylstyrene, divinylbenzene: As a substituent, methyl, ethyl, propyl, butyl, amyl, 2-
Ethylhexyl, octyl, nonyl, dodecyl, hexadecyl, octadecyl, cyclohexyl, benzyl, methoxyethyl, butoxyethyl, phenoxyethyl, allyl, methallyl, glycidyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-chloro-2-hydroxypropyl, Acrylate, methacrylate or fumarate having a group such as dimethylaminoethyl, diethylaminoethyl, etc .; ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, tri Mono (meth) acrylates such as methylolpropane, glycerin and pentaerythritol, or poly (meth) a Relate; vinyl acetate, vinyl butyrate or vinyl benzoate, acrylonitrile, cetyl vinyl ether, limonene, cyclohexene, diallyl phthalate, diallyl isophthalate, 2-, 3- or 4-
Vinyl pyridine, acrylic acid, methacrylic acid, acrylamide, methacrylamide, N-hydroxymethyl acrylamide or N-hydroxyethyl methacrylamide and their alkyl ether compounds; 2 mol or more of ethylene oxide or propylene oxide is added to 1 mol of neopentyl glycol. Di (meth) acrylate of diol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane; di or tri (meth) acrylate of triol; 2 mol or more per 1 mol of bisphenol A Di (meth) acrylate of diol obtained by adding ethylene oxide or propylene oxide of 2;
-A reaction product of 1 mol of hydroxyethyl (meth) acrylate and 1 mol of phenyl isocyanate or n-bruchisocyanate; poly (meth) acrylate of dipentaerythritol and the like.

As the polymer-forming oligomer,
For example, epoxy (meth) acrylate, polyester (meth) acrylate, polyurethane (meth) acrylate, polyether (meth) acrylate and the like can be used.

Examples of the photopolymerization initiator that can be used in the present invention include 2-hydroxy-2-methyl-1.
-Phenylpropan-1-one ("Darocur 1173" manufactured by Merck), 1-hydroxycyclohexyl phenyl ketone ("Irgacure 184" manufactured by Ciba-Geigy), 1
-(4-Isopropylphenyl) -2-hydroxy-2
-Methylpropan-1-one (Merck's "Darocur
1116 "), benzyl dimethyl ketal (" Irgacure 651 "manufactured by Ciba-Geigy), 2-methyl-1- [4-
(Methylthio) phenyl] -2-morpholinopropane-
1-on (Ciba-Geigy "Irgacure 90"
7 ”), a mixture of 2,4-diethylthioxanthone (“ Kayacure DETX ”manufactured by Nippon Kayaku Co., Ltd.) and ethyl p-dimethylaminobenzoate (“ Kayacure EPA ”manufactured by Nippon Kayaku Co., Ltd.), isopropylthioxanthone (Wordprekin) Examples of the liquid include 2-hydroxy-2-methyl-1-phenylpropane-, which is a mixture of "Cantacure ITX" manufactured by Sop Co.) and ethyl p-dimethylaminobenzoate.
1-one is particularly preferable in terms of compatibility with the liquid crystal material and the polymer-forming monomer or oligomer.

The reverse mode drive liquid crystal device of the present invention can be manufactured, for example, as follows.

That is, a liquid crystal material containing a compound of the general formula (1) and a polymer-forming monomer or oligomer, and, if necessary, a light source, are provided between two substrates having at least one electrode layer having transparency. Polymerization initiator, chain transfer agent,
It is composed of a transparent solid substance and a liquid crystal material by interposing a light control layer forming material containing a photosensitizer and a dye cross-linking agent and irradiating ultraviolet rays through the transparent substrate to polymerize the polymerizable composition. A liquid crystal device having a light control layer can be manufactured.

Schematic diagrams are shown in FIGS. 1 and 2 as an example of the liquid crystal device of the reverse mode drive of the present invention. FIG. 1 shows a state in which no voltage is applied, the alignment of the liquid crystal material becomes a planar surface, and light is transmitted therethrough, so that the panel becomes transparent.

FIG. 2 shows a state in which a voltage is applied, the orientation of the liquid crystal material becomes focal conic, and light is scattered, so that the panel becomes cloudy.

The normal mode driving liquid crystal device of the present invention can be manufactured, for example, as follows.

That is, a liquid crystal material containing a compound of the general formula (1) and a polymer-forming monomer or oligomer, and, if necessary, a light source, are provided between two substrates, at least one of which has an electrode layer and is transparent. Polymerization initiator, chain transfer agent,
By interposing a light control layer forming material containing a photosensitizer and a dye cross-linking agent and applying a saturation voltage of a liquid crystal material, irradiating ultraviolet rays through the transparent substrate to polymerize the polymerizable composition. It is possible to manufacture a liquid crystal device having a light control layer composed of a transparent solid substance and a liquid crystal material.

Schematic diagrams are shown in FIGS. 3 and 4 as an example of the normal mode driving liquid crystal device of the present invention. FIG. 3 shows a state in which no voltage is applied, the orientation of the liquid crystal material is focal conic, and light is scattered, so that the panel becomes cloudy.

FIG. 4 shows a state in which a voltage is applied, the alignment of the liquid crystal material is homeotropic, and light is transmitted, so that the panel becomes transparent.

In order to interpose the light control layer forming material between the two substrates, this light control layer forming material may be injected between the substrates by a known injection technique, but an appropriate solution is formed on one substrate. You may apply | coat uniformly using a coating machine, a spin coater, etc., and then superimpose and press-bond the other substrate.

The layer thickness of the light-modulating layer having a light-scattering property in the liquid crystal device of the present invention can be adjusted depending on the purpose of use, but it is between opacity and transparency due to light scattering. In order to obtain a sufficient contrast, the substrate interval is preferably in the range of 2 to 40 μm, particularly preferably 6 to 25 μm.

[0041]

EXAMPLES The present invention will be described more specifically below by showing examples of the present invention. However, the invention is not limited to these examples. In the following examples and comparative examples, "%" means "% by weight". Further, each of the evaluation characteristics in each example means the following symbols and contents.

(1) T ₀ ^NOR , T ₁₀₀ ^NOR : When the light transmittance of the light source is set to 100% and the light transmittance of the light is set to 0% when the device is removed from the light metering state, Light transmittance (%) of liquid crystal device when no voltage is applied in normal mode
Is T ₀ ^NOR , and the transmittance when the light transmittance does not change with an increase in applied voltage is T ₁₀₀ ^NOR .

(2) T ₀ ^REV , T ₁₀₀ ^REV : When the light transmittance of the light source is set to 100% and the light transmittance is set to 0% when the light source is turned on with the device removed from the metering state, Light transmittance (%) of liquid crystal device when no voltage is applied in reverse mode
Is T ₁₀₀ ^REV , and T ₀ ^REV is the transmittance when the light transmittance is minimized as the applied voltage increases.

(3) V ₉₀ ^NOR , V ₁₀ ^NOR : The light transmittance (T ₀ ^NOR ) of the liquid crystal device when no voltage is applied is set to 0%, and the light transmittance does not change as the applied voltage increases. When the transmittance (T ₁₀₀ ^NOR ) at the time is 100%, the applied voltage (V) at which the light transmittance is 90% is V ₉₀ ^NOR , and at the time when the light transmittance is 10% is V ₁₀ ^NOR . .

(4) V ₉₀ ^REV , V ₁₀ ^REV : The light transmittance (T ₁₀₀ ^REV ) of the liquid crystal device when no voltage was applied was set to 100%, and the light transmittance was minimized as the applied voltage was increased. When the transmittance (T ₀ ^REV ) at the time is 0%, the applied voltage (V) at which the light transmittance is 90% is V ₉₀ ^REV , and at the time when the light transmittance is 10% is V ₁₀ ^REV . .

(5) Steepness γ: γ = V ₁₀ ^REV / V ₉₀ ^REV , or γ = V ₉₀ ^NOR / V ₁₀ ^NOR

(6) Hysteresis: When the voltage is raised from 0 V, the voltage at which the light transmittance is 50% (T ₅₀ ^NOR or T ₅₀ ^REV ) is V ₅₀ ^UP, and when the voltage is lowered from a sufficiently high voltage, the light is emitted. When the voltage at which the transmittance is 50% is V ₅₀ ^DOWN , ΔV = V ₅₀ ^UP −V ₅₀ ^DOWN is used as the evaluation value of the hysteresis phenomenon and the hysteresis width. (7) Contrast: Contrast = T ₁₀₀ ^NOR / T ₀ ^NOR ,
Alternatively, contrast = T ₀ ^REV / T ₁₀₀ ^REV

(Example 1) Formula (a)

[0049]

[Chemical 3]

2.5% of the compound and a nematic liquid crystal composition "RO-571" manufactured by F. Hoffmann-La Roche 97.
A liquid crystal composition (A) consisting of 5% was prepared. The properties of this liquid crystal composition (A) were as follows.

Transition temperature 62.6 ° C. (NI) Spiral pitch 2.0 μm (In the above, N represents a nematic phase and I represents an isotropic liquid phase. The same applies hereinafter.)

This liquid crystal composition (A) was 97.8%, and the polymerizable composition was of the formula (II)

[0053]

[Chemical 4]

2.0% of the compound of, as a polymerization initiator,
"Darocur 1173" (Merck 2-hydroxy-2-
Methyl-1-phenylpropan-1-one) 0.2% of a dimming layer forming material was sprayed on the electrode layer with a spacer having an average particle diameter of 9 μm in a small amount to form a 5 × 5 cm ITO electrode layer and a polyimide alignment film. The polymerizable composition was polymerized by sandwiching it between the two glass plates and irradiating it with ultraviolet rays. The polymerization conditions are metal halide lamp (80W /
under a cm ² ), a glass substrate having a light control layer forming material sandwiched therebetween was passed at a speed of 3.5 m / min, and ultraviolet rays having an energy equivalent to 500 mJ / cm ² were irradiated to obtain a liquid crystal device. .

The obtained liquid crystal device was driven in the reverse mode, and the characteristics were as follows. V ₁₀ ^REV : 14.3V V ₉₀ ^REV : 10.5V γ: 1.4 Hysteresis: 0.8V Contrast: 25

(Example 2) Formula (b)

[0057]

[Chemical 5]

A liquid crystal composition (B) consisting of 2% of the compound of the above and 98% of "RO-571" was prepared. This liquid crystal composition (B)
The various characteristics of were as follows. Transition temperature 62.4 ℃ (NI) Spiral pitch 2.0 μm

A liquid crystal device was obtained in the same manner as in Example 1 except that the liquid crystal composition (B) was used instead of the liquid crystal composition (A).

The obtained liquid crystal device was driven in the reverse mode, and the characteristics were as follows. _{^{V 10 REV: 12.3V V 90 REV}} : 9.0V γ: 1.4 Hysteresis: 0.6V

(Example 3) Formula (c)

[0062]

[Chemical 6]

2.5% of the compound of and "RO-571" 97.5
% Liquid crystal composition (C) was prepared. The properties of this liquid crystal composition (C) were as follows.

Transition temperature 61.0 ° C. (NI) Spiral pitch 2.0 μm

A liquid crystal device was obtained in the same manner as in Example 1 except that the liquid crystal composition (C) was used instead of the liquid crystal composition (A).

The obtained liquid crystal device was driven in reverse mode, and the characteristics were as follows. V ₁₀ ^REV : 13.2V V ₉₀ ^REV : 10.0V γ: 1.3 Hysteresis: 0.6V

(Comparative Example 1) "CB-15" (cholesteric liquid crystal material manufactured by Merck & Co.) 7.4% and "RO-571" 92.6.
%, A liquid crystal composition (X) was prepared.

The properties of this liquid crystal composition (X) were as follows. Transition temperature 59.0 ° C. (N−I) Helical pitch 2.0 μm A liquid crystal device was prepared in the same manner as in Example 1 except that the liquid crystal composition (X) was used instead of the liquid crystal composition (A). Obtained.

The liquid crystal device thus obtained was driven in the reverse mode and had the following characteristics. Hysteresis: 1.2V Contrast: 17.5 (Comparative Example 2) "CB-15" 2.5% and "RO-571" 97.
A liquid crystal composition (Y) consisting of 5% was prepared.

The characteristics of this liquid crystal composition (Y) were as follows. Hysteresis: 1.0 V Contrast: 1.9 (Example 4) 97.8% of the above liquid crystal composition (A), 2.0% of the compound of the formula (II) as a polymerizable composition, and "Darocur" as a polymerization initiator. 1173 ”A light control layer forming material consisting of 0.2% is sandwiched between two glass plates each having a 5 × 5 cm ITO electrode layer and a polyimide alignment film with a small amount of spacers having an average particle size of 9 μm scattered on the electrode layer, The polymerizable composition was polymerized by irradiating with ultraviolet rays while applying a voltage of 20V. The polymerization conditions were 500 under a metal halide lamp (80 W / cm ² ) which was passed through a glass substrate having a material for forming a light control layer at a speed of 3.5 m / min.
A liquid crystal device was obtained by irradiating with ultraviolet light having an energy equivalent to mJ / cm ² .

The obtained liquid crystal device was driven in the normal mode, and the characteristics were as follows. V ₁₀ ^NOR : 3.3V V ₉₀ ^NOR : 11.4V Hysteresis: 2.4V Contrast: 10

Example 5 A liquid crystal device was obtained in the same manner as in Example 4, except that the liquid crystal composition (B) was used instead of the liquid crystal composition (A).

The liquid crystal device thus obtained was driven in the normal mode and had the following characteristics. V ₁₀ ^NOR : 3.0V V ₉₀ ^NOR : 8.6V Hysteresis: 3.4V

Example 6 A liquid crystal device was obtained in the same manner as in Example 4 except that the liquid crystal composition (C) was used instead of the liquid crystal composition (A).

The obtained liquid crystal device was driven in the normal mode, and the characteristics were as follows. V ₁₀ ^NOR : 4.7V V ₉₀ ^NOR : 9.6V Hysteresis: 3.8V

Comparative Example 3 A liquid crystal device was obtained in the same manner as in Example 4, except that the liquid crystal composition (X) was used instead of the liquid crystal composition (A).

The liquid crystal device thus obtained was driven in the normal mode, and the characteristics were as follows. Hysteresis: 4.0 V Contrast: 4.9 (Comparative Example 4) A liquid crystal was prepared in the same manner as in Example 4 except that the liquid crystal composition (Y) was used instead of the liquid crystal composition (A). I got a device.

The obtained liquid crystal device was driven in the normal mode, and the characteristics were as follows. Hysteresis: 3.0V Contrast: 1.8

[0079]

The liquid crystal device of the present invention is a light-scattering liquid crystal device which can be driven in normal mode and reverse mode, has low voltage drivability, has a small hysteresis width, and has a high contrast.

Therefore, the liquid crystal device of the present invention is extremely useful as a display device for computer terminals, a display element for projection, glass for automobiles and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of the structure of a liquid crystal device of the present invention.

FIG. 2 is a cross-sectional view showing an example of the structure of the liquid crystal device of the present invention.

FIG. 3 is a cross-sectional view showing an example of the structure of the liquid crystal device of the present invention.

FIG. 4 is a cross-sectional view showing an example of the structure of the liquid crystal device of the present invention.

[Explanation of symbols]

Substrate having 1 electrode layer 2 Liquid crystal material 3 Transparent solid substance

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-3-200927 (JP, A) JP-A-1-279223 (JP, A) JP-A-3-292389 (JP, A) JP-A-64- 42454 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/1333

Claims (7)

(57) [Claims] 1. A photopolymerizable composition and a compound represented by the general formula (1): (In the formula, R ¹ represents an alkyl group having 1 to 12 carbon atoms, an alkoxyl group, an alkenyl group having 2 to 12 carbon atoms or an alkenyloxy group, and ring A and ring B are each independently a fluorine atom or 1,4-phenylene group optionally substituted by a methyl group, trans-1,4-cyclohexylene group, pyrimidine-2,5-diyl group or pyridine-2,5-diyl group, wherein C ring is halogen Represents a phenyl group which may be substituted with an atom or an alkyl group having 1 to 12 carbon atoms, Y is a single bond, -CO
O -, - OCO -, - CH 2 CH 2 -, - C≡C -, - C
H ₂ O-or -OCH ₂ - represents, n represents 0 or 1, * denotes an optically active center. Crystal device material characterized by comprising a liquid crystal material containing a compound represented by). 2. At least one substrate having an electrode layer is transparent, and two dimming layers supported between the substrates,
The liquid crystal device, wherein the light control layer is composed of a transparent solid substance and the liquid crystal material according to claim 1,
The body material polymerizes the photopolymerizable composition according to claim 1.
A liquid crystal device characterized by comprising: 3. The liquid crystal device according to claim 2, wherein the transparent solid substance is contained in the liquid crystal material in the form of gel. 4. The alignment film is provided on two transparent substrates, at least one of which has an electrode layer.
3. The liquid crystal device according to item 3 . 5. The content of the transparent solid substance in the light control layer is
A range of 0.1 to 7% by weight.
3. The liquid crystal device according to item 3 . 6. A liquid crystal material is a chiral nematic liquid crystal material or a cholesteric liquid crystal material, according to claim 2 or helical pitch characterized in that it is a 0.5~5μm
3. The liquid crystal device according to item 3 . 7. The liquid crystal device according to claim 6, wherein the light control layer has a thickness of 2 to 40 μm.