JPH09258180A - Liquid crystal device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drive a liquid crystal device without any problem for practical use even in a low temp. region by suing a transparent solid material obtd. by polymn. of a polymerizable compsn. containing a specified deriv. SOLUTION: A material to form a light-controlling layer is held between two substrates having electrode layers at least one of which is transparent. The material to form a light-controlling layer consists of a liquid crystal material, a polymerizable compsn. containing a polyfunctional (meth)acrylate deriv., unifunctional alkyl (meth)acrylate deriv. and unifunctional (meth)acrylate deriv, having a liquid crystal suelton, a photopolymn. initiator, and if necessary, a chain moving agent, a sensitizer for light, a crosslinking agent, dyes and other components. This material to form a lightcontrolling layer is irradiated with active rays to polymerize the polymerizable compsn. Thus, the light-controlling layer is formed between the two substrates by forming a transparent solid material having a structure of dispersino of the liquid crystal material, or, the light-controlling layer is formed by forming a transparent solid material having a three-dimensional mesh structure in a continuous layer of the liquid crystal material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-scattering type liquid crystal display device capable of forming a large area with a scattering-type bright display screen and a method for manufacturing the same, and more specifically to shutting off, releasing and lighting light, or illuminating light. It is possible to control the scattering, transmission limitation, blocking, and transmission of electricity electrically or thermally. It is used as a screen for blocking the field of view in building windows and show windows, and as a curtain for lighting control, as well as characters and figures. Is displayed, and the display is electrically switched to display a display such as an advertising board, a guide board, or a decorative display board, or a high information display such as a display for OA equipment,
The present invention also relates to a light-scattering type liquid crystal display element used as a projection type display device for projection and the like and a manufacturing method thereof.

[0002]

2. Description of the Related Art As a method of manufacturing a large-sized and inexpensive liquid crystal device which is bright and has good contrast without requiring a polarizing plate and alignment treatment, Japanese Patent Publication No. 58-501631 and US Pat. No. 4,435,047. The specification and the like disclose a method in which liquid crystal droplets are dispersed in a polymer by encapsulating the liquid crystal and the polymer is formed into a film. Here, as the encapsulating substance, gelatin, gum arabic,
Polyvinyl alcohol and the like have been proposed.

However, in a liquid crystal device in which liquid crystal droplets are dispersed in a polymer, sufficient transparency can be obtained in addition to the troublesome operation of optimizing the matching and non-matching of the individual refractive indexes of the liquid crystal material and the polymer. It requires a high voltage of 25 V or more and does not have a low driving voltage characteristic that is important in the practical application of a liquid crystal device for display.

In addition to the technique of forming liquid crystal droplets by dispersing liquid crystal droplets in such a polymer, low voltage drivability, high contrast, and time which are important characteristics required for practical use of liquid crystal display devices. As a technique for enabling division driveability, US Pat. No. 5,304,323 and JP-A-1-198725 disclose that a liquid crystal material forms a continuous layer, and a polymer substance is contained in the continuous layer. A liquid crystal device having a structure in which is distributed in a three-dimensional mesh is disclosed.

Further, Japanese Patent Application Laid-Open No. 4-40417 discloses that
Monofunctional alkyl (meth) acrylate compound,
Japanese Unexamined Patent Publication (Kokai) No. 6-340587 discloses a technique capable of low voltage driving by using a polymer material obtained by polymerizing a polymerizable composition containing a monofunctional (meth) acrylate compound having a liquid crystal skeleton. Has been done.

[0006]

However, a liquid crystal material including a liquid crystal device formed by forming a polymer having a three-dimensional network structure in a continuous layer of the liquid crystal material, and a dimming layer formed by forming the polymer. In a liquid crystal device, since the “driving voltage temperature dependency” in which the driving voltage changes depending on the driving temperature is large, simple matrix driving cannot practically drive in a wide temperature range.
Further, even in the static drive, in the temperature range where the drive voltage of the liquid crystal device rises, the drive voltage is not always low enough to use the IC driver for the liquid crystal device which is currently widely used.

Further, when driving in a low temperature range of −10 ° C. or less, which is a practical driving temperature, there occurs a phenomenon that the light does not return to the scattering state even if the electric field is removed from the state where the light is transmitted by applying the electric field. The contrast deteriorates significantly in the temperature range,
Practical problem that it can not be driven substantially (hereinafter,
It is called "low temperature memory phenomenon". ) Was being held.

The problem to be solved by the present invention is that the light scattering can be performed at a low voltage and a high contrast as compared with the prior art, and further, the temperature dependence of the driving voltage is small, and can be driven practically without any trouble even in a low temperature range. Type liquid crystal display device.

[0009]

As a result of intensive studies, the inventors of the present invention have solved the above problems.

That is, in order to solve the above-mentioned problems, the present invention has two substrates, at least one of which has an electrode layer and which is transparent, and a light control layer supported between the substrates. In a liquid crystal device containing a liquid crystal material and a transparent solid substance, the transparent solid substance is (1) a polyfunctional (meth) acrylate derivative, (2) a monofunctional alkyl (meth) acrylate derivative, and (3) a liquid crystal. Provided is a liquid crystal device which is a transparent solid substance obtained by polymerizing a polymerizable composition containing a monofunctional (meth) acrylate derivative having a skeleton.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid crystal device of the present invention can be manufactured, for example, as follows. That is, between at least one transparent substrate having an electrode layer,
(I) liquid crystal material, (II) (1) polyfunctional (meth) acrylate derivative, (2) monofunctional alkyl (meth) acrylate derivative, and (3) monofunctional (meth) acrylate derivative having a liquid crystal skeleton. A polymerizable composition containing (III) a photopolymerization initiator and (IV) as an optional component, a dimming layer forming material consisting of a chain transfer agent, a photosensitizer, a cross-linking agent, a dye, etc. is interposed, A light control layer formed by forming a transparent solid substance having a structure in which a liquid crystal material is dispersed between two substrates by polymerizing the polymerizable composition by irradiating the light layer forming material with actinic rays, Alternatively, a light control layer is formed by forming a transparent solid substance having a three-dimensional network structure in a continuous layer of liquid crystal material.

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. Then, two substrates are opposed to each other and are obtained at an appropriate interval. Also, at least one of them
It must be transparent and make the light control layer sandwiched between the two sheets visible from the outside. However, 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. This board has
Appropriate transparent or opaque electrodes may be arranged on the entire surface or a part thereof depending on the purpose.

A light control layer made of a liquid crystal material and a transparent solid substance is interposed between the two substrates. In addition, it is usually desirable to interpose a spacer for holding a space between the two substrates, as in a known liquid crystal device.

As the spacer, for example, various beads for liquid crystal cells such as plastic beads, silica beads and alumina can be used.

In the liquid crystal device of the present invention, the contrast and the driving voltage change depending on the thickness of the light control layer. When the thickness of the dimming layer is small, the driving voltage becomes extremely low, the driving can be performed by using a general-purpose circuit, and the device has low power consumption. When the thickness of the light control layer is large, the light control layer has a high scattering property when no voltage is applied, and a white and bright device is obtained.

The thickness of the light control layer can be freely selected according to each application, but if it is too thin, the contrast is lowered, and if it is too thick, the drive voltage is sufficiently lower than that of the conventional one, but the drive voltage rises and at the time of driving. Therefore, the range of 5 to 100 μm is preferable, and the range of 8 to 60 is preferable.
The micron range is particularly preferred.

The liquid crystal material used in the present invention does not need to be a single liquid crystal compound, and may be a mixture containing two or more kinds of liquid crystal compounds or substances other than the liquid crystal compounds. What is normally recognized as a liquid crystal material in this technical field may be used, and one having a positive dielectric anisotropy is preferable. The liquid crystal used is preferably a nematic liquid crystal, a smectic liquid crystal or a cholesteric liquid crystal, and a nematic liquid crystal is particularly preferable. In order to improve the performance, a cholesteric liquid crystal, a chiral nematic liquid crystal, a chiral smectic liquid crystal, a chiral compound, or the like may be appropriately contained.

The liquid crystal material that can be used in the present invention is a compounded composition composed of the compounds shown below. The characteristics of the liquid crystal material, that is, the phase transition temperature, melting point, viscosity of the isotropic liquid and liquid crystal, It can be appropriately selected and blended for the purpose of considering the birefringence and the dielectric anisotropy, or adjusting the solubility with the polymerizable composition and the like.

The liquid crystal material is benzoic acid ester-based,
Cyclohexanecarboxylic acid ester type, biphenyl type,
Various liquid crystal compounds such as terphenyl type, phenylcyclohexanoic acid type, biphenylcyclohexanoic acid type, pyrimidine type, dioxane type, cyclohexane cyclohexane ester type and tolan type are used.

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 tar-
Phenyl, 4-substituted biphenyl 4'-substituted cyclohexane, 2- (4-substituted phenyl) 5-substituted pyrimidine, 4
-Substituted 4'-substituted tolan and the like can be mentioned.

The ratio of the liquid crystal material in the light control layer is 60.
The range is preferably from 99 to 99% by mass, particularly preferably from 70 to 90% by weight. (Hereinafter, “%” means “% by mass”.)

The transparent solid substance formed in the light control layer may be one in which a liquid crystal material is dispersed in a polymer in the form of droplets, but one having a three-dimensional network structure is more preferable.

It is preferable that the three-dimensional network structure portion of the transparent solid substance is filled with a liquid crystal material, and the liquid crystal material is continuously formed, whereby a disordered state of liquid crystal molecules is formed. , Forms a non-uniform optical interface and causes light scattering.

The average mesh size of the three-dimensional mesh structure is 0.
The range of 2 to 5 μm is preferable, and further 0.5 to 3 μm.
Is more preferable.

The transparent solid substance having a three-dimensional network structure interposed in the continuous layer of the liquid crystal material is not limited to a solid substance and has flexibility, flexibility and elasticity as long as it can be used according to the purpose. Is also good.

The polymerizable composition used in the present invention has (1) a polyfunctional (meth) acrylate derivative, (2) a monofunctional alkyl (meth) acrylate derivative, and (3) a liquid crystal skeleton as essential components. It may contain a monofunctional (meth) acrylate derivative, and may further contain a polymer-forming monomer or oligomer as an optional component.

(1) Polyfunctional type (meta) used in the present invention
Examples of acrylate derivatives include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, trimethylolpropane, glycerin and pentaerythritol. (Meth) acrylate or poly (meth) acrylate;
Di (meth) acrylate of diol obtained by adding 2 moles or more of ethylene oxide or propylene oxide to 1 mole of neopentyl glycol; obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of trimethylolpropane Di (meth) acrylate or tri (meth) acrylate of triol; Di (meth) acrylate of diol obtained by adding 2 mol or more of ethylene oxide or propylene oxide to 1 mol of bisphenol A; Poly (meth) acrylate of dipentaerythritol Pivalic acid ester neopentyl glycol diacrylate; caprolactone modified hydroxypivalic acid ester neopentyl glycol diacrylate; straight-chain aliphatic diacrylate;
Polyolefin-modified neopentyl glycol diacrylate: epoxy (meth) acrylate, polyester (meth) acrylate, polyurethane (meth) acrylate, polyether (meth) acrylate, fluoro (meth) acrylate, silicone ( (Meth) acrylate; poly (meth) acrylate of tris- (hydroxyethyl) -isocyanuric acid; poly (meth) acrylate of tris- (hydroxyethyl) -phosphoric acid; di (meta) of di- (hydroxyethyl) -dicyclopentadiene. ) Acrylate; di- or tri (meth) acrylate having an isocyanurate ring in the molecule can be mentioned.

The (2) monofunctional alkyl (meth) acrylate derivative used in the present invention has a large effect of driving at a low voltage, and among them, the monofunctional branched alkyl (meth) acrylate derivative is a liquid crystal molecule having a low polarity. In addition to lowering the anchoring force to drive at a low voltage, the bulky three-dimensional structure of the branched chain inhibits the alignment of liquid crystal molecules at low temperatures and suppresses the low temperature memory phenomenon, which is particularly preferable.

The number of carbon atoms in the alkyl group of the monofunctional alkyl (meth) acrylate derivative is preferably in the range of 5 to 30, more preferably 8 to 24. When the number of carbon atoms in the alkyl group of the monofunctional alkyl (meth) acrylate derivative is less than 5, the effect of low voltage driving is small, and the number of carbon atoms in the alkyl group of the monofunctional alkyl (meth) acrylate derivative is small. If you have more than 30,
It is not preferable because the white turbidity tends to decrease when no voltage is applied.

If the proportion of the monofunctional alkyl (meth) acrylate derivative used is too small, the effect of driving at a low voltage becomes small, and if it is too large, the white turbidity when no voltage is applied tends to decrease, so that the polymerizability is low. The range of 5 to 60% in the composition is preferable, and the range of 10 to 50% is more preferable.

Examples of the (2) monofunctional alkyl (meth) acrylate derivative used in the present invention include amyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate and octyl (meth).
Acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, octadecyl (meth) acrylate, behenyl (meth) acrylate, isooctyl (meth) acrylate, isodecyl (meth) acrylate, Isotridecyl (meth) acrylate, isomyristyl (meth) acrylate, isovalmityl (meth) acrylate, isostearyl (meth) acrylate, isoicosyl (meth) acrylate, isodocosyl (meth) acrylate, isotetracosyl (meth) acrylate, isohexacosyl (meth) acrylate
Acrylate, isooctacosyl (meth) acrylate, enyl (meth) acrylate, nerolidyl (meth)
Examples thereof include acrylate and farnesyl (meth) acrylate.

Examples of commercially available monofunctional alkyl (meth) acrylate derivatives used in the present invention include "LA" (lauryl acrylate) manufactured by Kyoeisha Chemical Co., Ltd.
"SA" (stearyl acrylate), "IM-A"
(Isomyristyl acrylate), "IS-A" (isostearyl acrylate), "light ester L" (lauryl methacrylate), "light ester L-5"
(Alkyl methacrylate), "Light ester L-
7 "(alkyl methacrylate)," Light Ester T
Examples thereof include D ”(tridecyl methacrylate),“ light ester L-8 ”(alkyl methacrylate),“ LTA ”(alkyl acrylate) manufactured by Osaka Organic Co., cetyl acrylate, and the like.

The (2) monofunctional alkyl (meth) acrylate derivative used in the present invention can be prepared by a known method.
(Meth) acrylic acid or (meth) acrylic acid chloride is used to obtain a (meth) acrylic acid of a linear or branched aliphatic alcohol.

Alkyl alcohol, which is a commercially available raw material for production, includes general-purpose aliphatic alcohols,
For example, Tokyo Chemical Co., Ltd. "trimethylhexanol",
"7-Ethyl-2-methylundecanol", "farnesol", "geraniol", "nerol", "nerolidol", "Fineoxochol 1" manufactured by Nissan Chemical Co., Ltd.
40 "(isomyristyl alcohol)," Fineoxochol 1600 "(isovalmityl alcohol),
"Fineoxo call 180", "Fineoxo call 1800" (isostearyl alcohol), Kao Corporation "Calcol 200GD" (2-octyldodecanol), "Calcol 160GD" (2-hexyldecanol), Kyowa Hakko Co., Ltd. Oxo call 1213 ",
"Oxocall 1215", "Oxocall 1415"
"Dobanol 23" and "Dovanol 2" manufactured by Mitsubishi Petrochemical Co., Ltd.
5 ”,“ Dovanol 45 ”and the like.

The (3) monofunctional (meth) acrylate derivative having a liquid crystal skeleton used in the present invention is, for example, a compound represented by the general formula (I).

[0036]

Embedded image

[In the formula, R represents a hydrogen atom or a methyl group, the 6-membered rings A and B each independently represent a 1,4-phenylene ring or a 1,4-cyclohexylene ring, and X is a single bond or 1,2-ethanediyl group, Y is a general formula

[0038]

[Chemical 6]

(Z ¹ and Z ³ each independently represent a hydrogen atom or a fluorine atom, Z ² represents a fluorine atom or a cyano group, and Z ⁴ and Z ⁵ each independently represent 1 to 20 carbon atoms.
Represents an alkyl group, an alkoxyl group or an alkenyl group. ) Represents a substituent, and n represents an integer of 0 or 1. ] The compound represented by these can be mentioned.

Typical compounds represented by the general formula (I) (Nos. 1 to 10) and their phase transition temperatures are shown in Table 1 below. In the table below, C represents a crystalline phase, S represents a smectic phase, N represents a nematic phase, and I represents an isotropic liquid phase, and each numerical value represents a phase transition temperature (unit: ° C). Further, each compound used was sufficiently purified after removing impurities by a method such as distillation, column purification, and recrystallization.

[0041]

[Table 1]

The (3) monofunctional (meth) acrylate derivative having a liquid crystal skeleton used in the present invention has a large effect of driving at a low voltage, and has a small hysteresis width which is a problem in high-quality gradation display. Have the effect of

If the ratio of the (3) monofunctional (meth) acrylate derivative having a liquid crystal skeleton used in the present invention is too small, the effect of low voltage driving becomes small, and if it is too large, it becomes cloudy when no voltage is applied. Since the property tends to decrease, the range of 5 to 30% in the polymerizable composition is preferable, and 10 to 2 is preferable.
The range of 5% is more preferable.

The monofunctional (meth) acrylate derivative (3) having a liquid crystal skeleton used in the present invention can be prepared by a known method using (meth) acrylic acid or (meth) acrylic acid chloride and represented by the general formula (II )

[0045]

Embedded image

(In the formula, R represents a hydrogen atom or a methyl group, the 6-membered rings A and B are 1,4-phenylene rings, or
1,4-cyclohexylene ring, X is a single bond,
Represents an ethyne bond, and Y is

[0047]

Embedded image

Z ¹ and Z ³ represent a hydrogen atom or a fluorine atom, Z ² represents a fluorine atom or a cyano group, and Z ⁴ and Z ⁵ represent an alkyl group or an alkoxyl group having 1 to 20 carbon atoms. Represents an alkenyl group, and n represents an integer of 0 or 1. ) Is obtained by (meth) acrylicizing the compound represented by

Examples of the polymer-forming monomer as an optional component include styrene, chlorostyrene, α-methylstyrene, divinylbenzene; as a substituent, methyl, ethyl, propyl, butyl, amyl, 2-ethylhexyl, cyclohexyl, benzyl. , Methoxyethyl, butoxyethyl, phenoxyethyl, allyl, methallyl,
Acrylate, methacrylate or fumarate having a group such as glycidyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-chloro-2-hydroxypropyl, dimethylaminoethyl, diethylaminoethyl; vinyl acetate, vinyl butyrate or vinyl benzoate, acrylonitrile, Cetyl vinyl ether, limonene, cyclohexene, diallyl phthalate, 2-, 3- or 4-vinylpyridine, acrylic acid, methacrylic acid, acrylamide,
Methacrylamide, N-hydroxymethyl acrylamide or N-hydroxyethyl methacrylamide and their alkyl ether compounds; reaction products of 1 mol of 2-hydroxyethyl (meth) acrylate and 1 mol of phenyl isocyanate or n-butyl isocyanate. be able to.

Examples of the polymerization initiator include 2-hydroxy-2-methyl-1-phenylpropan-1-one (“Darocur 1173” manufactured by Merck & Co., Inc.), 1-hydroxycyclohexyl phenylketone (“Ciba Geigy”, manufactured by Ciba Geigy). Irgacure 184 "), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-
On (Merck "Darocur 1116"), benzyl dimethyl ketal (Ciba Geigy "Irgacure 651"), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1 (Ciba)・ Geigy's "Irgacure 907"), 2,4-diethylthioxanthone (Nippon Kayaku's "Kayacure DET"
X ") and ethyl p-dimethylaminobenzoate (" Kayacure EPA "manufactured by Nippon Kayaku Co., Ltd.), isopropylthioxanthone (" Cantacure ITX "manufactured by Ward Prekinsopp) and ethyl p-dimethylaminobenzoate And acylphosphine oxide (“Lucillin TPO” manufactured by BASF).

The proportion of the photopolymerization initiator used is preferably 0.1 to 10% with respect to the polymerizable composition.

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, but an appropriate solution coater or spin coater may be provided on one of the substrates. Alternatively, the other substrate may be applied and then the other substrate may be superposed and pressure-bonded.

Further, a liquid crystal is formed by applying a light control layer constituent material on one substrate to a uniform thickness, polymerizing and curing the polymerizable composition to form a light control layer, and then bonding the other substrate. A device manufacturing method is also effective.

In the polymerization of the polymerizable composition in a liquid crystal material by ultraviolet irradiation, the light irradiation intensity and the irradiation amount also need to have a certain intensity or more. However, the formation of a three-dimensional network and the formation of the three-dimensional network are required by selecting an appropriate light intensity. The size of the mesh can be made uniform.

In the polymerization of the polymerizable composition, it is preferable that the light control layer forming material starts the polymerization in an isotropic liquid state.

More preferably, as the method for irradiating light, uniform irradiation in time and in plane is carried out by irradiating the photopolymerizable composition interposed between the substrates with intense light instantaneously to cause polymerization to proceed. This is effective in making the mesh size uniform. That is, it is possible to form a transparent solid substance having a uniform three-dimensional network structure in a liquid crystal material by irradiating it with ultraviolet light uniformly and at an appropriate intensity, and as a result, the obtained liquid crystal device is It has a clear threshold value and steepness, and time-division driving becomes possible.

[0057]

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

Hereinafter, in the examples, "%" means "mass%".
And each of the evaluation characteristics means the following symbols and contents. T ₀ : White turbidity; Light transmittance (%) when applied voltage is 0 T ₁₀₀ : Transparency; Light transmittance (%) when the applied voltage hardly increases with increasing applied voltage V ₁₀ : Threshold: T _{0 =} 0%, T ₁₀₀ = 100
% Applied voltage (Vrms
) V ₉₀ : saturation voltage; same as above, applied voltage (Vrms) at which light transmittance becomes 90% CR: contrast = T ₁₀₀ / T ₀ ΔV / ΔT: temperature dependence; (V ₉₀ (0 ° C.)-V ₉₀ (40
℃)) × 1000/40 (Unit: mV / ℃)

Further, the illuminance of ultraviolet rays is a unit meter UIT-10 with a photodetector UVD-365PD manufactured by Ushio Inc.
It was measured using 1.

(Example 1) <Liquid crystal material> 78.0% of the following liquid crystal composition (A) <Polymerizable composition>"KAYARAD-HX-220" 14.04% (Nippon Kayaku Co., Ltd., Caprolactone-modified hydroxypivalate neopentyl glycol diacrylate) 4- (trans-4-butylcyclohexyl) cyclohexyl acrylate (No. 1 compound in Table 1) 2.16% "ISA" (Shin Nakamura Chemical Co., Ltd.) Isostearyl acrylate) 5.4% <Polymerization initiator>"Irgacure651" 0.4% (benzyl dimethyl ketal manufactured by Ciba-Geigy) is used as a light control layer forming material in a glass of 11.0 μm. It is sandwiched between two ITO electrode glass substrates coated with fiber spacers and the entire substrate is kept in a uniform solution state of the light control layer forming material. Reluctant, ultraviolet rays 40 mW / cm ² 60
The polymerizable composition was cured by irradiation for 2 seconds to obtain a liquid crystal device having a light control layer having a thickness of 11.2 μm and comprising a liquid crystal material and a transparent solid substance.

As a result of observing the light control layer of the obtained liquid crystal device with an electron microscope, a transparent solid substance having a three-dimensional network could be confirmed.

The results of measuring the relationship between the applied voltage and the light transmittance at 40 ° C., 25 ° C. and −20 ° C. of the obtained liquid crystal device are shown in Table 2 below.

[0063]

[Table 2]

The temperature dependence of the driving voltage ΔV / ΔT
Was 30 mV / ° C.

As described above, it can be understood that the liquid crystal device obtained in Example 1 is practical as a liquid crystal device because it can be driven at a low temperature without any trouble and the driving voltage has a small temperature dependency.

Composition of liquid crystal composition (A)

Embedded image

[0067] Physical properties transition temperature 97.1 ° C. of the liquid crystal composition (A) (N-I) <-20 ℃ (C-N) refractive index _{n e = 1.738 n o = 1.514} Δn = 0.224 Threshold voltage (Vth) 1.50V Dielectric anisotropy Δε = 17.3

Comparative Example 1 <Liquid crystal material> Liquid crystal composition (A) 78.0% <Polymerizable composition>"KAYARAD-HX-220" 14.04% 4- (trans-4-butyl) Cyclohexyl) Cyclohexyl acrylate (No. 1 compound in Table 1) 7.56% <Polymerization initiator> “Irgacure 651” 0.4% of the light control layer forming material made of glass fiber of 11.0 μm It is sandwiched between two ITO electrode glass substrates coated with spacers, and the entire substrate is kept in a uniform solution state with the light control layer forming material, while applying 40 mW / cm ² of ultraviolet light to 60
The polymerizable composition was cured by irradiation for 2 seconds to obtain a liquid crystal device having a light control layer having a thickness of 11.1 μm and comprising a liquid crystal material and a transparent solid substance.

As a result of observing the light control layer of the obtained liquid crystal device with an electron microscope, a transparent solid substance having a three-dimensional network could be confirmed.

The results of measuring the relationship between the applied voltage and the light transmittance at 40, 25 ° C. and −20 ° C. of the obtained liquid crystal device are shown in Table 3 below.

[0071]

[Table 3]

The temperature dependence ΔV / ΔT of the driving voltage is 90
It was mV / ° C., which was larger than that in Example 1.

From the results shown in Table 3, the liquid crystal device obtained in Comparative Example 1 exhibits almost the same performance as that of the liquid crystal device obtained in Example 1 at 25 ° C., but at -20 ° C. It can be understood that the transparent state after the application does not return to the scattering state without applying the voltage, and the actual driving cannot be performed.

Comparative Example 2 <Liquid crystal material> Liquid crystal composition (A) 78.0% <Polymerizable composition>"KAYARAD-HX-220" 14.04% "ISA" 7.56% < Polymerization Initiator> “Irgacure 651” 0.4% of the light control layer forming material is sandwiched between two ITO electrode glass substrates coated with 11.0 μm glass fiber spacers to form a light control layer on the entire substrate. While keeping the material in a uniform solution, apply 40 mW / cm ² of UV light to 60
The polymerizable composition was cured by irradiation for 2 seconds to obtain a liquid crystal device having a light control layer having a thickness of 11.2 μm and comprising a liquid crystal material and a transparent solid substance.

As a result of observing the light control layer of the obtained liquid crystal device using an electron microscope, a transparent solid substance having a three-dimensional network could be confirmed.

The results of measuring the relationship between the applied voltage and the light transmittance at 40, 25 ° C. and −20 ° C. of the obtained liquid crystal device are shown in Table 4 below.

[0077]

[Table 4]

From the results shown in Table 4, in the liquid crystal device obtained in Comparative Example 2, the temperature dependence ΔV / ΔT of the driving voltage was 14
It can be understood that it is not practical as a liquid crystal device because it is as large as 0 mV / ° C. and the driving voltage at a low temperature is greatly increased.

(Example 2) <Liquid crystal material> Liquid crystal composition (A) 78.0% <Polymerizable composition>"KAYARAD-HX-220" 14.04% 4- (4-decylphenyl) Phenyl acrylate 2.16% (Compound No. 3 in Table 1) "ISA" 5.4% <Polymerization initiator>"Irgacure651" 0.4% of the light control layer forming material of 11.0 μm It is sandwiched between two ITO electrode glass substrates coated with glass fiber spacers, and 40 mW / cm ² of UV light is applied to the entire substrate while keeping the light control layer forming material in a uniform solution state.
The polymerizable composition was cured by irradiating for 2 seconds to obtain a liquid crystal device having a light control layer having a thickness of 11.3 μm and comprising a liquid crystal material and a transparent solid substance.

As a result of observing the light control layer of the obtained liquid crystal device using an electron microscope, a transparent solid substance having a three-dimensional network could be confirmed.

The results of measuring the relationship between the applied voltage and the light transmittance at 40 ° C., 25 ° C. and −20 ° C. of the obtained liquid crystal device are shown in Table 5 below.

[0082]

[Table 5]

The temperature dependence of the driving voltage ΔV / ΔT
Was 35 mV / ° C.

As described above, it can be understood that the liquid crystal device obtained in Example 2 is practical as a liquid crystal device because it can be driven without trouble even at low temperatures and the temperature dependence of the driving voltage is small.

(Example 3) <Liquid crystal material> Liquid crystal composition (A) 78.0% <Polymerizable composition>"KAYARAD-HX-220" 14.04% 4- [4- (3, 4,5-Trifluorophenyl) cyclohexyl] cyclohexyl acrylate (No. 9 compound in Table 1) 2.16% “ISA” 5.4% <Polymerization initiator> “Irgacure 651” 0.4% The light control layer forming material is sandwiched between two ITO electrode glass substrates coated with 11.0 μm glass fiber spacers, and 40 mW / cm while maintaining the whole light control layer forming material in a uniform solution state. ² ultraviolet rays 60
The polymerizable composition was cured by irradiating for 2 seconds to obtain a liquid crystal device having a light control layer having a thickness of 11.3 μm and comprising a liquid crystal material and a transparent solid substance.

As a result of observing the light control layer of the obtained liquid crystal device with an electron microscope, a transparent solid substance having a three-dimensional network could be confirmed.

The results of measuring the relationship between the applied voltage and the light transmittance at 40 ° C., 25 ° C. and −20 ° C. of the obtained liquid crystal device are shown in Table 6 below.

[0088]

[Table 6]

The temperature dependence ΔV / ΔT of the driving voltage was Δ28 mV / ° C.

As described above, it can be understood that the liquid crystal device obtained in Example 3 is practical as a liquid crystal device because it can be driven at low temperature without any trouble and the driving voltage has a small temperature dependency.

(Example 4) <Liquid crystal material> Liquid crystal composition (A) 78.0% <Polymerizable composition>"KAYARAD-HX-220" 14.04% 4- (trans-4-butyl) Cyclohexyl) cyclohexyl acrylate (No. 1 compound in Table 1) 2.16% n-octyl acrylate 5.4% <Polymerization initiator> “Irgacure 651” 0.4% It is sandwiched between two ITO electrode glass substrates coated with 11.0 μm glass fiber spacers, and 40 mW / cm ² of UV light is applied to the entire substrate while keeping the light control layer forming material in a uniform solution state.
The polymerizable composition was cured by irradiation for 2 seconds to obtain a liquid crystal device having a light control layer having a thickness of 11.2 μm and comprising a liquid crystal material and a transparent solid substance.

As a result of observing the light control layer of the obtained liquid crystal device with an electron microscope, a transparent solid substance having a three-dimensional network could be confirmed.

The results of measuring the relationship between the applied voltage and the light transmittance at 40 ° C., 25 ° C. and −20 ° C. of the obtained liquid crystal device are shown in Table 7 below.

[0094]

[Table 7]

Further, the temperature dependence of the driving voltage ΔV / ΔT
Was 37 mV / ° C.

As described above, it can be understood that the liquid crystal device obtained in Example 4 is practical as a liquid crystal device because it can be driven without trouble even at a low temperature and the temperature dependence of the driving voltage is small.

(Example 5) <Liquid crystal material> Liquid crystal composition (A) 78.0% <Polymerizable composition>"KAYARAD-HX-220" 14.04% 4- (trans-4-butyl) Cyclohexyl) Cyclohexyl acrylate (No. 1 compound in Table 1) 2.16% “IM-A” (isomyristyl acrylate manufactured by Kyoeisha Chemical Co., Ltd.) 5.4% <Polymerization initiator> “Irgacure 651” The 0.4% dimming layer forming material is sandwiched between two ITO electrode glass substrates coated with 11.0 μm glass fiber spacers, and the dimming layer forming material is made into a uniform solution state over the entire substrate. While maintaining, 60 mW / cm ² UV light
The polymerizable composition was cured by irradiation for 2 seconds to obtain a liquid crystal device having a light control layer having a thickness of 11.1 μm and comprising a liquid crystal material and a transparent solid substance.

As a result of observing the light control layer of the obtained liquid crystal device with an electron microscope, a transparent solid substance having a three-dimensional network could be confirmed.

The results of measuring the relationship between the applied voltage and the light transmittance at 40 ° C., 25 ° C. and −20 ° C. of the obtained liquid crystal device are shown in Table 8 below.

[0100]

[Table 8]

Further, the temperature dependence of the driving voltage ΔV / ΔT
Was 30 mV / ° C.

As described above, the liquid crystal device obtained in Example 5 can be driven practically even at a low temperature, and the temperature dependence of the driving voltage is small. Therefore, it can be understood that it is practical as a liquid crystal device.

(Example 6) <Liquid crystal material> Liquid crystal composition (A) 78.0% <Polymerizable composition>"KAYARAD-HX-220" 14.04% 4- (4-trans-butyl) Cyclohexyl) phenyl acrylate (Compound No. 2 in Table 1) 2.16% "ISA" 5.4% <Polymerization initiator>"Irgacure651" 0.4% of the light control layer forming material. It is sandwiched between two ITO electrode glass substrates coated with 0 μm glass fiber spacers, and the entire substrate is kept in a uniform solution state with the dimming layer forming material, while applying 40 mW / cm ² of ultraviolet rays to 60
The polymerizable composition was cured by irradiating for 2 seconds to obtain a liquid crystal device having a light control layer having a thickness of 11.3 μm and comprising a liquid crystal material and a transparent solid substance.

As a result of observing the light control layer of the obtained liquid crystal device with an electron microscope, a transparent solid substance having a three-dimensional network could be confirmed.

The results of measuring the relationship between the applied voltage and the light transmittance at 40 ° C., 25 ° C. and −20 ° C. of the obtained liquid crystal device are shown in Table 9 below.

[0106]

[Table 9]

The temperature dependence of the driving voltage ΔV / ΔT
Was 20 mV / ° C.

As described above, the liquid crystal device obtained in Example 6 can be driven practically even at a low temperature, and the temperature dependence of the driving voltage is small, so it can be understood that it is practical as a liquid crystal device.

(Example 7) <Liquid crystal material> Liquid crystal composition (A) 78.0% <Polymerizable composition>"KAYARAD-HX-220" 14.04% 4- (4-pentylphenylethynyl) ) Phenyl acrylate (Compound No. 10 in Table 1) 2.16% "ISA" 5.4% <Polymerization initiator>"Irgacure651" 0.4% of a light control layer forming material of 11.0 μm It is sandwiched between two ITO electrode glass substrates coated with the glass fiber spacers, and the entire substrate is kept in a uniform solution state with the light control layer forming material while applying 40 mW / cm ² of ultraviolet light to 60
The polymerizable composition was cured by irradiating for 2 seconds to obtain a liquid crystal device having a light control layer having a thickness of 11.3 μm and comprising a liquid crystal material and a transparent solid substance.

As a result of observing the light control layer of the obtained liquid crystal device with an electron microscope, a transparent solid substance having a three-dimensional network could be confirmed.

The results of measuring the relationship between the applied voltage and the light transmittance at 40 ° C., 25 ° C. and −20 ° C. of the obtained liquid crystal device are shown in Table 10 below.

[0112]

[Table 10]

Further, the temperature dependence of the driving voltage ΔV / ΔT
Was 33 mV / ° C.

As described above, it can be understood that the liquid crystal device obtained in Example 10 is practical as a liquid crystal device because it can be driven without trouble even at low temperature and the temperature dependence of the driving voltage is small.

(Example 8) <Liquid crystal material> Liquid crystal composition (A) 78.0% <Polymerizable composition>"KAYARAD-HX-220" 14.04% 4- (4-octoxyphenyl) ) Phenyl acrylate (Compound No. 4 in Table 1) 2.16% "IM-A" 5.4% <Polymerization initiator>"Irgacure651" 0.4% of the light control layer forming material It is sandwiched between two ITO electrode glass substrates coated with a glass fiber spacer of 0.0 μm, and the entire substrate is kept in a uniform solution state with the light control layer forming material while applying 40 mW / cm ² of ultraviolet rays to 60
The polymerizable composition was cured by irradiating for 2 seconds to obtain a liquid crystal device having a light control layer having a thickness of 11.3 μm and comprising a liquid crystal material and a transparent solid substance.

As a result of observing the light control layer of the obtained liquid crystal device with an electron microscope, a transparent solid substance having a three-dimensional network could be confirmed.

The results of measuring the relationship between the applied voltage and the light transmittance at 40 ° C., 25 ° C. and −20 ° C. of the obtained liquid crystal device are shown in Table 11 below.

[0118]

[Table 11]

The temperature dependence of the driving voltage ΔV / ΔT
Was 38 mV / ° C.

As described above, it can be understood that the liquid crystal device obtained in Example 11 is practical as a liquid crystal device because it can be driven without trouble even at a low temperature and the temperature dependence of the driving voltage is small.

[0121]

The liquid crystal device of the present invention does not require a polarizing plate and has a bright display screen, is a large-area thin film type, can be driven at a low voltage, and has a bright and high reflectance. Display is possible, and further, driving is possible even in a low temperature range of −20 ° C., so that practicality is improved.

As described above, (1) a polyfunctional (meth) acrylate derivative, (2) a monofunctional alkyl (meth) acrylate derivative and (3) a monofunctional (meth) acrylate derivative having a liquid crystal skeleton are contained. The liquid crystal device of the present invention having a dimming layer containing a transparent solid substance obtained by polymerizing a polymerizable composition and a liquid crystal material has a low voltage drive, a high contrast, and a low temperature memory phenomenon even at a low temperature than ever before. It was possible to drive without causing any practical problems without causing any problem, and further, the temperature dependence of the driving voltage was small, and the practical driving in a wide temperature range by the simple matrix driving was possible.

Therefore, it is extremely useful not only as a conventional liquid crystal device for light control of this kind, but also as a liquid crystal device having a large screen and a thin shape and higher display quality.

Claims (8)

[Claims] At least one substrate having an electrode layer has two transparent substrates, and a dimming layer supported between the substrates.
In the liquid crystal device in which the light control layer contains a liquid crystal material and a transparent solid substance, the transparent solid substance is (1) a polyfunctional (meth) acrylate derivative, (2) a monofunctional alkyl (meth) acrylate derivative. And (3) a transparent solid substance obtained by polymerizing a polymerizable composition containing a monofunctional (meth) acrylate derivative having a liquid crystal skeleton. 2. A monofunctional (meth) acrylate derivative having a liquid crystal skeleton is represented by the general formula (I): [In the formula, R represents a hydrogen atom or a methyl group, and is a 6-membered ring A.
And B are each independently a 1,4-phenylene ring or 1,4
Represents a cyclohexylene ring, X is a single bond or 1,2
Represents an ethanediyl group, and Y is a compound represented by the general formula: (Z ¹ and Z ³ each independently represent a hydrogen atom or a fluorine atom, Z ² represents a fluorine atom or a cyano group, and Z ⁴
And Z ⁵ each independently represent an alkyl group, an alkoxyl group or an alkenyl group having 1 to 20 carbon atoms. ) Represents a substituent, and n represents an integer of 0 or 1. ] The liquid crystal device of Claim 1 which is a compound represented by these. 3. The liquid crystal device according to claim 1, wherein the monofunctional alkyl (meth) acrylate derivative is a monofunctional (meth) acrylate having a branched alkyl. 4. The liquid crystal device according to claim 1, wherein the light control layer has a three-dimensional mesh-like transparent solid substance in a continuous layer of a liquid crystal material. 5. An actinic ray is irradiated after a light control layer forming material containing a liquid crystal material, a polymerizable composition and a photopolymerization initiator is sandwiched between two substrates having at least one transparent electrode layer. In the method for producing a liquid crystal device, in which the polymerizable composition is polymerized to form a dimming layer having a liquid crystal material and a transparent solid substance, as the polymerizable composition,
(1) Polyfunctional (meth) acrylate derivative, (2) Monofunctional alkyl (meth) acrylate derivative, and (3)
A method for producing a liquid crystal device, which comprises using a polymerizable composition containing a monofunctional (meth) acrylate derivative having a liquid crystal skeleton. 6. A monofunctional (meth) acrylate derivative having a liquid crystal skeleton is represented by the general formula (I): [In the formula, R represents a hydrogen atom or a methyl group, and is a 6-membered ring A.
And B are each independently a 1,4-phenylene ring or 1,4
Represents a cyclohexylene ring, X is a single bond or 1,2
Represents an ethanediyl group, and Y is a compound represented by the general formula: (Z ¹ and Z ³ each independently represent a hydrogen atom or a fluorine atom, Z ² represents a fluorine atom or a cyano group, and Z ⁴
And Z ⁵ each independently represent an alkyl group, an alkoxyl group or an alkenyl group having 1 to 20 carbon atoms. ) Represents a substituent, and n represents an integer of 0 or 1. ] The manufacturing method of the liquid crystal device of Claim 5 characterized by being a compound represented by these. 7. The method for producing a liquid crystal device according to claim 5, wherein the monofunctional alkyl (meth) acrylate derivative is a monofunctional (meth) acrylate having a branched alkyl. 8. The method of manufacturing a liquid crystal device according to claim 5, wherein the actinic ray is ultraviolet light.