JPH04146414A - lcd device - Google Patents

Abstract

PURPOSE:To offer a liquid crystal device where a hysteresis phenomenon is improved and which has high voltage holding rate and can be driven at low voltage by orienting liquid crystals at random by a three-dimensional network solid material on one substrate side and orienting the liquid crystal in a fixed direction by an orienting film etc., on the other substrate side. CONSTITUTION:In a liquid crystal layer interposed between two substrates 1 having a transparent electrode layer 2, the layer having the uniform three- dimensional network solid material 3 is formed on the transparent electrode layer of one substrate, and the liquid crystal in contact with the transparent electrode layer or a liquid crystal orienting layer 5 on the other substrate is oriented in the fixed direction. By such constitution, the liquid crystal device which does not need a polarizing plate and has bright image quality is obtained. This device has high contrast between transparency-opacity, and is provided with threshold characteristic and steepness by which time division driving is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal device that can be made in a large area and a method for manufacturing the same. , blocking, and transmitting can be controlled electrically or thermally, and are used as screens for blocking visibility in building windows and show windows, as well as curtains for lighting control, as well as for displaying characters and figures. By electrically switching the display with high-speed response, LCDs are used as decorative display boards such as billboards, display devices for convenience store terminals that require bright screens, and projection display devices. Regarding devices.

[Prior art] Liquid crystal devices have conventionally been TN devices using nematic liquid crystals.
type and STN type have been put into practical use.

Also, devices using ferroelectric liquid crystals have been proposed.

Since these require a polarizing plate, there is a limit to how bright the surface can be, and since an alignment treatment is required, the yield during production of display devices is reduced.

On the other hand, as a method for manufacturing large, inexpensive liquid crystal devices that are bright and have good contrast without requiring polarizing plates or alignment processing, liquid crystal encapsulation is used to disperse liquid crystal droplets in a polymer and then turn the polymer into a film. method is known. Japanese Patent Publication No. 58-501631, U.S. Patent No. 4
．． No. 435.047 proposes gelatin, gum arabic, polyvinyl alcohol, etc. as the encapsulating material.
No. 02128 discloses a method in which liquid crystal is dispersed in an epoxy resin, and JP-A-61-305528 discloses a method in which the phase separation between a liquid crystal and a photocured material is fixed by light exposure.
-2231 discloses liquid crystals dispersed in a special ultraviolet curable polymer, and JP-A-63-144321 discloses
A method of mixing polyester, liquid crystal, and a solvent to form a film is known.

However, Special Publication No. 58-501631, Special Publication No. 6
In liquid crystal devices obtained by the techniques disclosed in No. 1-502128 and Japanese Patent Application Laid-open No. 61-2231, a high voltage of 25 V or more, in many cases from 50 V to 200 V, is required to obtain sufficient transparency. Japanese Patent Publication No. 61-3055
28 and Japanese Unexamined Patent Publication No. 1-62615, the most excellent one is lO, and in the case of multi(), it is 8 or less, which does not meet the characteristics required for practical use of liquid crystal devices. I wasn't prepared.

Furthermore, in order to obtain the necessary dimming properties, each refractive index must be selected sufficiently to optimize the match between the individual refractive index of the liquid crystal material and the refractive index of the photocured material. It was an unavoidable annoyance.

In order to enable low voltage drivability, high contrast, and time-division drivability, which are important characteristics required for the practical use of liquid crystal devices as mentioned above, Japanese Patent Application Laid-Open No. 1-198725 discloses the following:
A liquid crystal device is disclosed that has a structure in which a liquid crystal material forms a continuous phase and a polymer substance is distributed in a three-dimensional network in this continuous phase.

[Problems to be Solved by the Invention] However, in addition to the characteristics such as low voltage drivability, high contrast, time division drivability, and bright image quality required of a liquid crystal device, this liquid crystal device has the following problems. Ta.

In other words, in this liquid crystal device, a hysteresis phenomenon occurs in the electro-optical characteristics in which the transmittance is different when the voltage increases and when the voltage decreases, which reduces the margin of time-division driving and makes it difficult to display gradations. The problem was above. There are problems in that the resistance of liquid crystal devices decreases due to light, heat, and other factors during the manufacturing of liquid crystal devices, resulting in increased power consumption, reduced lifespan, and flickering of display image quality due to poor voltage retention. Ta. In addition, in order to create a liquid crystal device that is suitable for the application, such as driving voltage and operating temperature range, it is necessary to adjust the manufacturing conditions of the liquid crystal device, such as changing the compatibility by changing the combination of liquid crystal and polymer, controlling dispersion, and phase separation. There was the annoyance of having to consider the matter thoroughly.

The problem to be solved by the present invention is to provide a liquid crystal device that has an improved hysteresis phenomenon, has a high voltage holding rate, is driven at a low voltage, and is not limited by the manufacturing conditions due to the combination of liquid crystal and polymer. be.

[Means for Solving the Problems] As a result of intensive study on the structure of a liquid crystal device that utilizes a light-scattering opaque state and a transparent state, the present inventors have found that the hysteresis phenomenon has been improved, and the device has a high voltage holding rate and a low We have established technology for liquid crystal devices that are driven by voltage and are not limited by manufacturing conditions due to the combination of liquid crystals and polymers.

That is, in order to solve the above-mentioned problems, the present invention includes two substrates, at least one of which is transparent and has a transparent electrode layer, and a liquid crystal layer sandwiched between the substrates. A layer having a uniform three-dimensional network solid material is provided on the transparent electrode layer, and the liquid crystal in contact with the transparent electrode layer of the other substrate or the liquid crystal alignment layer provided on the transparent electrode layer is aligned in a certain direction. To provide a liquid crystal device characterized by:

The liquid crystal device of the present invention is characterized in that on one substrate side, the liquid crystal is randomly oriented by a three-dimensional network solid material, and on the other substrate side, the liquid crystal is oriented in a fixed direction by an alignment film or the like. This is an excellent method in which light scattering is caused by random alignment of the liquid crystal, and the transmittance-applied voltage characteristics can be mainly improved by alignment in a certain direction.

The substrate used in the present invention may be made of a rigid material, such as glass or metal, or may be made of a flexible material, such as a plastic film. Two substrates can be placed facing each other with an appropriate distance between them. In addition, at least one of the layers has transparency, and a liquid crystal layer sandwiched between the two layers and a layer having a uniform three-dimensional network solid material on the other side. The light control layer, which consists of a layer containing a solid substance, must be visible from the outside world.

However, complete transparency is not a guarantee.

If the liquid crystal device is used to act on light passing from one side of the device to the other, both substrates are provided with suitable transparency. Appropriate transparent or opaque electrodes may be disposed on the entire surface or part of the substrate depending on the purpose.

A liquid crystal material is sandwiched between a substrate provided with a layer having a uniform three-dimensional network solid material and a substrate provided with a transparent electrode layer or a liquid crystal alignment layer provided on the transparent electrode layer. A spacer for maintaining the distance between these substrates can be interposed between these substrates, as in a well-known liquid crystal device.

FIGS. 1 and 2 show cross-sectional views of examples of the structure of the liquid crystal device of the present invention. In the figure, 1 is the substrate, 2 is the transparent electrode,
3 represents a three-dimensional network solid material, 4 represents a liquid crystal material, 5 represents an alignment film, and 6 represents a sealant.

Figure 1 shows a structure between two substrates, in which a layer having a uniform three-dimensional network solid material is provided on one transparent electrode layer, and a vertical alignment layer is provided on the transparent electrode layer of the other substrate. This is an example in which liquid crystals are sandwiched, and the liquid crystals are randomly oriented on one substrate and vertically oriented on the other substrate.

Figure 2 shows a structure between two substrates, in which a layer having a uniform three-dimensional network solid material is provided on one transparent electrode layer, and a horizontal dispensing layer is provided on the transparent electrode layer of the other substrate. This is an example in which a liquid crystal is sandwiched between two substrates, and the liquid crystal is randomly oriented on one substrate and horizontally oriented on the other substrate.

The alignment of the liquid crystals only needs to be in a certain direction, and in particular, it is not limited to vertical or horizontal directions, but may be in between.

The liquid crystal material used in the present invention does not necessarily need to be a single liquid crystal compound, but may be a mixture containing two or more types of liquid crystal compounds or substances other than liquid crystal compounds,
Any material that is generally recognized as a liquid crystal material in this technical field may be used, and among these materials, those having positive dielectric anisotropy are preferred. The liquid crystals used are nematic liquid crystal,
Smectic liquid crystals and cholesteric liquid crystals are preferred, and nematic liquid crystals are particularly preferred. In order to improve the performance, chiral compounds such as cholesteric liquid crystal, chiral nematic liquid crystal, chiral smectic liquid crystal, dichroic dye, etc. may be included as appropriate.

The liquid crystal material that can be used in the present invention is a compound composition composed of a compound group represented by the following general formula, and the characteristics of the liquid crystal material are as follows: phase transition temperature between isotropic liquid and liquid crystal, melting point, viscosity, Δn1 They are appropriately selected, blended, and used for the purpose of improving Δε and solubility with the polymerizable composition.

, -Q- represents -C=C- or -COO-, X represents CN, R''R' O or NC3, Y represents H, F or CI, R and R' each independently represents an alkyl group having 1 to 6 carbon atoms, m represents 1 or 2, and n represents 0 or 1.

The transparent solid substance formed on at least one of the substrates may be dispersed on particles, but preferably has a three-dimensional network structure.

The three-dimensional network portion of the transparent solid material is filled with a liquid crystal material, and the liquid crystal material is required to form a continuous layer, and by forming a disordered state of the liquid crystal material,
It is essential for forming an optical interface and causing light scattering.

As these transparent solid components, synthetic resins are suitable. A thermosetting resin or an ultraviolet curable resin is preferable as a material that provides a three-dimensional network structure. Also suitable are synthetic resins soluble in organic solvents and synthetic resins soluble in water.

As a method for forming a layer containing a transparent solid material having a uniform three-dimensional network structure on a substrate, for example, (1
) a homogeneous solution of a liquid crystal material, a polymer-forming monomer or oligomer, and optionally a photopolymerization initiator, or (2) a solvent, a polymer-forming monomer or oligomer, and optionally photopolymerization initiation. A homogeneous solution with the agent is sandwiched between two substrates having transparent electrode layers, or
It may be coated on one substrate having a transparent electrode layer using a coater such as a spin coater, and then the other auxiliary plate may be layered, and this may be irradiated with ultraviolet rays or thermally polymerized and cured. A three-dimensional mesh-like synthetic resin layer is formed. Next, after peeling off one of the two substrates sandwiching the transparent solid substance with the three-dimensional network structure obtained in this way or the auxiliary plate, the transparent solid substance with the three-dimensional network structure is removed. Cleaning and removing uncured monomers or oligomers, liquid crystal materials, and solvents from materials. Note that the peeling step can be facilitated by applying a mold release agent on one of the substrates or the auxiliary plate in advance.

The transparent polymer substance with a three-dimensional network structure interposed in the continuous phase of the liquid crystal material is not limited to being rigid, and may be flexible, pliable, and elastic as long as it meets the purpose. .

Examples of polymer-forming monomers include styrene, chlorostyrene, α-methylstyrene, dihinylhensen; substituents include methidi, 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-
Acrylates, methacrylates or fumarates with groups such as 2-hydroxypropyl, dimethylaminoethyl, diethylaminoethyl; ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, neo Poly(meth)acrylates or poly(meth)acrylates such as pentyl glycol, trimethylolpropane, glycerin and pentaerythritol: vinyl acetate,
Vinyl acetate or vinyl benzoate, acrylonitrile, cetyl vinyl ether, limonene, cyclohexene, diallyl phthalate, diallyl isophthalate, 2-13-
or 4-vinylpyridine, acrylic acid, methacrylic acid,
Acrylamide, methacrylamide, N-hydroxymethylacrylamide or N-hydroxyethylmethacrylamide and their alkyl ether compounds; Triol di- or triol obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane. (Meth)acrylate: diol di(meth)acrylate obtained by adding 2 moles or more of ethylene oxide or propylene oxide to 1 mole of neopentyl glycol; diol di(meth)acrylate obtained by adding 1 mole or more of ethylene oxide or propylene oxide to 1 mole of bisphenol A. Di(meth)acrylate of diol obtained by poly(meth)acrylate of tris-(hydroxyethyl)-isocyanuric acid; poly(meth)acrylate of tris-(hydroxyethyl)-phosphoric acid; mono(meth)acrylate or di(meth)acrylate of di(hydroxyethyl)-dicyclopentadiene Acrylate; pivalic acid ester neopentyl glycol diacrylate; caprolactone-modified hydroxypivalic acid ester neopentyl glycol diacrylate; straight-chain aliphatic diacrylate; polyolefin-modified neopentyl glycol diacrylate, etc., but trimethylolpropane triacrylate , tricyclodecane dimethylol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, polypropylene glycol diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, and tris-(acrylic bovine diethyl) in cyanurate.

Examples of polymer-forming oligomers include (1) epoxy (meth)acrylate obtained by esterifying bisphenol A-type epoxy resin with (meth)acrylic acid, and optionally long-chain fatty acids such as coconut oil fatty acid; Epoxies such as long-chain fatty acid modified products and epoxy (meth)acrylates with carboxyl groups obtained by adding dibasic acid anhydrides, tetrabasic acid dianhydrides, and trimellitic anhydride to epoxy (meth)acrylates with hydroxyl groups. (Meth)acrylate and its modified products.

(2) A diisocyanate compound as described in British Patent No. 1.147.732 (Japanese Unexamined Patent Publications No. 5137193 and No. 51-138797) is reacted with a polyol in advance. An addition polymerizable compound having two or more acryloyloxy groups and/or methacryloyloxy groups in the molecule obtained by further reacting the obtained terminal isocyanate compound with β-hydroxyalkyl acrylate and/or methacrylate.

(3) dibasic acid anhydrides such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, or head acid anhydride as described in Japanese Patent Publication No. 47-3262; A linear polyester compound having a large number of pendant acryloyloxy groups and/or methacryloyloxy groups obtained by ring-opening polymerization of glycidyl acrylate and/or glycidyl methacrylate.

(4) A polyhydric alcohol having at least three esterifiable hydroxyl groups on adjacent carbon atoms, acrylic acid and/or methacrylic acid, dicarboxylic acid and Polymerizable esters prepared by coesterification with dicarboxylic acids selected from the group consisting of their anhydrides.

(5) British Patent No. 628.150, U.S. Patent No. 3,020.255 and the monthly magazine "Macromolecules" Volume 4, No.
Formaldehyde, methyl alcohol and β-
A polyacrylic (or polymethacrylic) modified triazine resin obtained by reacting hydroxyalkyl acrylate (or methacrylate), etc.

(6) An unsaturated polyester resin obtained by reacting a glycidyl etherified polyhydroxy compound with acrylic acid or methacrylic acid as described in US Pat. No. 3,377,406.

(7) General formula described in U.S. Patent No. 3.455.801 and U.S. Patent No. 3.455.802 (wherein R is a divalent saturated or represents an unsaturated aliphatic hydrocarbon group, where R'' has 2 carbon atoms.
~10 divalent saturated aliphatic hydrocarbon group, R'' represents a hydrogen atom or a methyl group, and n represents an integer from 1 to 14.) Acryloyloxy or methacryloyloxy groups at both ends. A polyester compound having

(8) General formula % described in U.S. Patent No. 3.483.104 and U.S. Patent No. 3.470.079 (wherein A represents 10- or -NH-) At least two -NB- groups in one molecule, R represents a divalent saturated aliphatic or unsaturated aliphatic hydrocarbon group, and R'' represents a divalent saturated or unsaturated aliphatic hydrocarbon group. Alternatively, it represents a cyclic hydrocarbon, R'' represents a hydrogen atom or an alkyl group, and n is 1
Represents an integer between ~14. ) Diacrylic modified (or dimethacrylic modified) represented by
Polyamide compound.

(9) The general formula described in Japanese Patent Publication No. 4g-37246 (wherein, X represents a hydrogen atom or an acyl group, and R represents a divalent saturated or unsaturated aliphatic or cyclic hydrocarbon group) Representation,
R1 represents a divalent aliphatic hydrocarbon group, R2 represents a hydrogen atom or an alkyl group, and A represents 10- or -NH.
Diacrylic modification (or dimethacrylic modification) represented by - and at least two in one molecule are -Nl (-, n represents an integer from 1 to 14)
Polyamide compound.

(lO) Saturated or unsaturated dibasic acids or their anhydrides, as described in U.S. Pat. A diacrylic-modified (or dimethacrylic-modified) polyester compound obtained by further reacting a compound having a carboxyl group at the terminal with glycidyl acrylate or glycidyl methacrylate.

(11) In the molecule as described in Japanese Patent Publication No. 48-12075, the general formula is -CH, -C-R COOCHICHCH,0COC=CH2 (wherein, X represents an acyl group or a urethane group, and R represents a hydrogen atom, a chlorine atom, a methyl group, or a cyano group. .

As a polymerization initiator, for example, 2-hydroxy-2-methyl-1-phenylpropan-1-one (manufactured by Merck & Co., Ltd.
Talocure 1173J), 1-hydroxycyclohexylphenyl ketone (manufactured by Ciba Geigy [Irgacure 184J), 1-(4-isopropylphenyl)
-2-Hydroxy-2-methylpropan-1-one (manufactured by Merck & Co., Ltd. [Talocure 1116J]), benzyl dimethyl ketal (thi/N+, manufactured by Geigy Co., Ltd. [Irgacure 6])
51J), 2-methyl-1-(4-(methylthio)phenyl]-2-morpholinopropanone-1 (manufactured by Chinoku Geigy Co., Ltd. [Irgacure 907J), 2,4-diethylthioxanthone (manufactured by Nippon Kayaku Co., Ltd. " Kayacure DE
TXJ ) and ethyl p-dimethylaminebenzoate (Kayacure EPAJ manufactured by Nippon Kayaku Co., Ltd.), a mixture of isopropylthioxanthone (Cantacure ITXJ manufactured by Ward Prekin Sotubs Co., Ltd.) and ethyl p-dimethylaminobenzoate , acylphosphine acid (BA)
Examples include "Lucirin TPOJ" manufactured by SF Co., Ltd., but in terms of compatibility with liquid 2-hydroxy-2-mef-1-phenylpropane-1-onka liquid crystal materials and polymer-forming monomers or oligomers, preferable.

In order to control the thickness of the transparent solid substance that is uniformly adhered to the substrate, a spacer may be mixed into a solution of a liquid crystal material and a monomer or oligomer, or a solution of an organic solvent and a monomer or oligomer, A spacer may be applied on one side of the substrate.

Further, the cleaning method may be the same as that used for a glass substrate having a transparent electrode of a well-known liquid crystal device. Ultrasonic cleaning may also be performed.

The substrate on which the cleaned transparent solid material is placed needs to be sufficiently dried by a method such as vacuum drying or vacuum heating drying.

Moreover, a three-dimensional network polymer can also be produced by using a polymer instead of the monomer or oligomer and drying by evaporation of a solvent or water.

Methods for uniformly forming a transparent solid material having a three-dimensional network structure on a substrate are not limited to these methods.

If the average diameter of the three-dimensional network structure formed from a transparent solid material is too large or too small compared to the wavelength of light, the light scattering property tends to deteriorate, so the average diameter is 0.2 to 2.
A range of μm is preferred. In addition, the layer thickness of the layer containing the transparent solid material is 1 to 10 μm, depending on the purpose of use, in order to obtain a sufficient contrast between the opacity due to light scattering and the transparency achieved electrically or thermally. A range of is preferred.

The liquid crystal device of the present invention includes, for example, a substrate on which a layer having a uniform three-dimensional network solid material obtained by the above method is formed and a substrate having a uniformly oriented alignment layer obtained by a commonly practiced method. It can be manufactured using the following method.

That is, (1) one substrate has a transparent electrode layer on which a layer containing a uniform three-dimensional network solid substance is formed, and a substrate has an alignment layer in a certain direction on the transparent electrode layer. The substrates are pasted together and fixed using a sealant to form a panel in the same manner as a well-known liquid crystal device. A method of injecting liquid crystal material by evacuating the inside of the panel, immersing the panel's liquid crystal injection port in the liquid crystal material, and then returning the pressure to normal atmospheric pressure.

(2) After coating a liquid crystal material on a substrate on which a layer containing a uniform three-dimensional network solid material is formed on a transparent electrode layer or on a substrate having an alignment layer in a fixed direction on a transparent electrode layer, the other side is coated with a liquid crystal material. Stack the substrates on top of each other and thoroughly degas them under reduced pressure. Next, a method of manufacturing a liquid crystal device by fixing the periphery of both substrates using a sealant.

The distance between the substrates is preferably in the range of 2 to 30 μm, and 5 to 20 μm.
A range of μm is particularly preferred.

The liquid crystal device manufactured in this way has the following characteristics compared to conventional light scattering type liquid crystal devices.

(1) Drive with low voltage.

(2) Since the resistance of the sandwiched liquid crystal material can be increased, a liquid crystal device having a high voltage holding rate can be provided.

(3) Since the hysteresis phenomenon can be improved, a liquid crystal device with excellent gradation display can be provided.

(4) Since there is no restriction due to the combination of various materials such as liquid crystal materials and synthetic resins, display characteristics can be easily improved and an excellent liquid crystal device can be provided.

[Examples] Hereinafter, examples of the present invention will be shown to explain the present invention more specifically. However, the present invention is not limited to these examples.

In addition, in the following Examples and Comparative Examples, "%" represents "% by weight".

Moreover, each of the evaluation characteristics in each example and comparative example means the following symbols and contents.

(1) Number of time-division drive lines (N,,,): N,,, = [(α”+1)/(α”-1)]”However,
γ=V,. /Vt.

(2) V. , v8°: The light transmittance (To) of the device when no voltage is applied is 0%, and the transmittance (T1°) when the light transmittance does not change as the applied voltage increases is 100%. When doing so, the applied voltage (volts) at which the light transmittance is 90% is V. , light transmittance 1
The applied voltage when it becomes 0% is ■1°.

(3) Contrast: When the device is removed from the photometer and the light transmittance when the light source is on is 100% and the light transmittance when the light source is off is 0%, the applied voltage is V. and ■. The light transmittance obtained when is T, respectively. And when T1°, contrast=T. / T l.

(4) Hysteresis: When the voltage is increased from Ov, the light transmittance is 50% (T
,. ), the voltage becomes ■,. '', and the voltage at which the light transmittance becomes 50% when lowered from a sufficiently high voltage is V.'@
When it is 1, △V=V. Lee ■. 4m#s is the evaluation value of the hysteresis phenomenon, and is the hysteresis width.

(5) Response speed: When the applied voltage is switched from 0 to the ON state, the time required for the light transmittance to reach 90% is defined as the rise time τ1, and when the applied voltage is switched from the ON state to the OV state, the light transmittance is 10
The time it takes to reach 1 is defined as the rising time τ, and the time it takes for the ON state voltage to change to 1; τ is defined as the response speed.

(6) Retention rate: Apply a square wave with a frame frequency of 60 Hz, a voltage of 4.5 V, and an ON state time of 67 μs, measure the charge accumulated in the ON state as Qo, and measure the leakage current in the OFF state with a high impedance voltmeter. And when the residual charge is Q, retention rate = Q/Q.

It is expressed as

Example 1 rHX-620J (
Caprolactone-modified hydroxypivalic acid ester neopentyl glycol diacrylate (manufactured by Nippon Kayaku Co., Ltd.) 1
9.8%, 0.2% of 2-hydroxy-2-methyl-1-phenylpropan-1-one as a polymerization initiator, and 80% of the following liquid crystal (A) as a liquid crystal material. A small amount of spacers with a particle size of 10 μm were scattered on a transparent electrode layer, and the spacers were sandwiched between a 5 x 5 cm ITO glass plate and a polycarbonate plate of the same size (Mitsubishi Gas Chemical's "Iupilon"), and ultraviolet rays were irradiated from the ITO glass plate side. The polymer-forming oligomer was cured. The curing conditions are
It was passed under a metal halide lamp (AOW, "Cm") at a speed of 3.5 m/min, and was irradiated with ultraviolet rays with an energy equivalent to 500 m J/min. When the cross section of the cured product formed between the substrates was observed with a scanning electron microscope, a three-dimensional polymer network was observed.

An ITO glass plate obtained by peeling off the polycarbonate plate from this ultraviolet irradiated object and to which a three-dimensional network solid substance was uniformly adhered was immersed in ethanol, subjected to an ultrasonic cleaning process, and then dried under vacuum heat.

The ■To glass plate to which this three-dimensional network solid substance was evenly adhered was bonded to a 5 x 5 cm ITO glass plate on which a vertical alignment layer was prepared using lecithin in a conventional manner, and rDSA-001J (Rodik) was used as a sealant. An empty cell was prepared by immobilizing the cell using an epoxy resin (manufactured by Seiko Co., Ltd.). This cell was placed under vacuum and reduced pressure, and the injection port was immersed in the following liquid crystal (B), and then returned to normal atmospheric pressure to obtain a liquid crystal device of the present invention.

The properties of the obtained liquid crystal device were as follows.

vlo・■、.・ γ ・ N * a 11 ・ Contrast: τ1=τ−1 Hysteresis: Retention rate ・ 2.4■ 3.2■ 1.3 12.7 1: 10 23 ms 0.1■ 65.0% Liquid crystal ( Composition of A): Composition of liquid crystal (B): Transition temperature refractive index 68.5°C (N-I) <-25°C (C-N) n, = 1.787 n, = 1.583 Δ n = 0 .254 Dielectric constant ε,, = 37.8 8 above = 10.9 Δε = 26.9 Example 2 In Example 1, instead of the ITO glass plate provided with a vertical alignment layer made by lecithin in a conventional manner A liquid crystal device of the present invention was obtained in the same manner as in Example 1, except that a 5×5c11 ITO glass plate provided with a horizontal alignment film prepared by rubbing a polyimide film by a well-known method was used.

The properties of the obtained liquid crystal device were as follows.

Vlo: 3.2V ■,. : 4.5V γ : 1.4 N,,, : 9.3 Contrast: 1:16 τr3τ6 : 26 ms Hysteresis: 0. IV retention rate: 65.0% Example 3 As a polymer-forming oligomer, rHX-620J 9.8%, as a polymerization initiator, 2-hydroxy-2-methyl-1-phenylpropan-1-one 0 A homogeneous solution of .2% and 80% of the liquid crystal (B) as a liquid crystal material was mixed with a 5% 5cm ITO glass plate and a 3.5X 3.5cm ITO glass plate with a small amount of spacers having an average particle size of 4 μm sprinkled on the transparent electrode layer.
The polymer-forming oligomer was sandwiched between 5 ctn polycarbonate plates ("Iupilon" manufactured by Mitsubishi Gas Chemical) and irradiated with ultraviolet rays from the ITO glass plate side under the same curing conditions as in Example 1 to cure the polymer-forming oligomer. When the cross section of the cured product formed between the substrates was observed with a scanning electron microscope, a three-dimensional polymer network was observed.

An ITO glass plate obtained by peeling off the polycarbonate plate from this ultraviolet irradiated object and to which a three-dimensional network solid substance was uniformly adhered was immersed in ethanol, subjected to an ultrasonic cleaning process, and then dried under vacuum heat.

A TO glass plate to which this three-dimensional network solid substance was evenly adhered was screen printed using a mixture of a small amount of spacers with an average particle size of 10jtm and a sealant rDSA-001J, and then polyimide was applied to the other side by a well-known method. 5% 5cm ITO with horizontal alignment layer prepared by rubbing the membrane
An empty cell was prepared by bonding glass plates together such that the distance between transparent electrode layers was 10 μm. This cell was placed under vacuum and reduced pressure, and the injection port was immersed in a mixture of 98% of the liquid crystal (B) and 2% of rS-416J (a black dichroic dye manufactured by Mitsui Toatsu Chemical Co., Ltd.), and then the cell was returned to normal atmospheric pressure. By returning it, a liquid crystal device of the present invention was obtained.

The properties of the obtained liquid crystal device were as follows.

I8 ■,.

γ N1.8 Contrast: τ, = τd Hysteresis: Retention rate 3.6v 5.5v 1.52 6.3 1:420 20.3 ms 0.10V 64.0% Comparative Example 1 As a polymer-forming oligomer , “HX-620J19
．． 8%, 0.2% of 2-hydroxy-2-methyl-1-phenylpropan-1-one as a polymerization initiator, and 80% of the liquid crystal (B) as a liquid crystal material, and the average particle size was 1.
A small amount of 0 μm spacer was mixed, this mixed solution was sandwiched between two 5% 5 cm ITO glass plates, and the polymer-forming oligomer was cured by irradiation with ultraviolet light under the same curing conditions as in Example 1 for comparison. An example liquid crystal device was obtained. When a cross section of the light control layer formed between the substrates was observed using a scanning electron microscope, a three-dimensional polymer network was observed.

The properties of the obtained liquid crystal device were as follows.

Vlo: 6.9V Via: 12.8V γ: 1.88 N,,,: 3.2 Contrast: 1:19 τ, = τ,: 19.8 ms Hysteresis: 0.9V Retention rate: 21.0 % Comparative Example 2 As a polymer-forming oligomer, rHX-620J 1
9%, 2-hydroxy-2-methfk as a polymerization initiator
-1-phenylpropan-1-one 1%, the liquid crystal (B) 78.4% as a liquid crystal material, and black dichroic dye rS
-416J 1.6%, mixed a small amount of spacers with an average particle size of 4 μm, and spread this mixture onto two 5×5C'm
Although the polymer-forming oligomer was sandwiched between two ITO glass plates and irradiated with ultraviolet rays under the same curing conditions as in Example 2, the polymer-forming oligomer was not cured and a liquid crystal device having a light scattering layer could not be produced.

V of the liquid crystal device obtained in Comparative Example 1. ,■,. From the comparison of the values of hysteresis and retention with the respective values of the liquid crystal device obtained in each example, the liquid crystal device of the present invention has the following properties:
It is clear that this is an excellent product that can be driven at low voltage and has significantly improved hysteresis phenomenon and retention rate.

Furthermore, from the comparison between Comparative Example 2 and Example 3, it is clear that the liquid crystal device of the present invention can be easily manufactured to suit the purpose of use without being constrained by the combination of liquid crystal and polymer forming material. It is.

[Effects of the Invention] The liquid crystal device of the present invention does not require a polarizing plate, has a bright image quality, has a large transparent-opaque contrast of about 1:15 to 28, and has a threshold value that allows time-division driving. It has characteristics and steepness. In particular, we have improved the hysteresis phenomenon that was a problem in conventional light-scattering liquid crystal devices, greatly improved the resistance of the light-scattering layer during the fabrication of denomination chairs, and made it possible to have a high voltage holding rate. .

Due to these features, the liquid crystal device of the present invention can provide a liquid crystal device that is capable of gradation display and eliminates screen flickering.

Therefore, the liquid crystal device of the present invention is useful as a display device for a convenience store terminal and a display device for projection.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing the structure of the liquid crystal device of the present invention. 1...Substrate, 2...Transparent electrode 3...
Three-dimensional network solid substance 4...Liquid crystal material 5...Alignment film 6...Sealant agent Patent attorney Katsutoshi Takahashi Figure

Claims (1)

[Claims] 1. Two substrates having a transparent electrode layer, at least one of which is transparent, and a liquid crystal layer sandwiched between the substrates, wherein a liquid crystal layer is placed on one of the substrates, and a liquid crystal layer is sandwiched between the substrates. , characterized in that a layer having a uniform three-dimensional network solid substance is provided, and the liquid crystal in contact with the transparent electrode layer of the other substrate or the liquid crystal alignment layer provided on the transparent electrode layer is aligned in a certain direction. LCD device. 2. The liquid crystal device according to claim 1, wherein the liquid crystal alignment layer provided on the transparent electrode layer is made of polyimide. 3. The liquid crystal device according to claim 1 or 2, wherein the liquid crystal in contact with the liquid crystal alignment layer provided on the transparent electrode layer is aligned in a direction perpendicular to the direction of the substrate. 4. The liquid crystal device according to claim 1 or 2, wherein the liquid crystal in contact with the liquid crystal alignment layer provided on the transparent electrode layer is aligned in a direction horizontal to the direction of the substrate. 5. The liquid crystal device according to claim 1, 2, 3 or 4, wherein the liquid crystal device is driven by a switching element comprising a thin film transistor or a diode provided on the substrate. 6. The liquid crystal material contained in the liquid crystal layer is nematic liquid crystal,
Claims 1, 2, 3, 4 containing a liquid crystal compound selected from the group consisting of smectic liquid crystal and cholesteric liquid crystal.
, or the liquid crystal device according to 5. 7. Claims 1, 2, 3, wherein the liquid crystal layer contains a dichroic dye.
4. The liquid crystal device according to 4, 5, or 6. 8. The liquid crystal material contained in the liquid crystal layer undergoes a reversible phase change between a liquid crystal phase and an isotropic liquid phase due to temperature changes, thereby reversibly changing between a light-scattering opaque state and a transparent state. The liquid crystal device according to claim 1, 2, 3, 4, or 6. 9. A claim in which the liquid crystal material contained in the liquid crystal layer reversibly changes its molecular arrangement by a voltage applied between electrodes of the substrate, thereby reversibly changing between a light scattering state and a transparent state. 8. The liquid crystal device according to item 1, 2, 3, 4, 5, 6 or 7. 10. The liquid crystal device according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein the three-dimensional network solid material is made of a synthetic resin. 11. The layer thickness of the layer containing the three-dimensional network solid material is 1 to 1
Claims 1, 2, 3, 4, 5, 6, 7 in the range of 0 μm
, 8, 9 or 10.