JP2770690B2 - Electro-optical element and method for manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electro-optical device having a liquid crystal-polymer composite film formed on a substrate and a method for manufacturing the same. More specifically, the present invention relates to an electro-optical element having a liquid crystal-polymer composite film that can be widely applied as a display element such as a display, a light control element, a light modulation element, an optical shutter, a memory element, and the like, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Low molecular weight liquid crystal materials are most commonly used as display materials for flat panel displays, such as TN type liquid crystal display elements such as clock faces and STN type for portable computers and portable word processors. Widely applied to liquid crystal display devices and the like. These control the transmission / non-transmission (ON / OFF) of light by using the property that the plane of polarization of light passing through the liquid crystal layer changes according to the applied voltage. Is required. In addition, it is indispensable to perform an alignment film treatment for the liquid crystal layer to assume a specific alignment state.

In recent years, liquid crystal display devices in which a low-molecular liquid crystal material is held in a polymer binder have been proposed. For example,
JP-T-58-501631 discloses a film in which nematic liquid crystal droplets encapsulated in polyvinyl alcohol are dispersed. When an electric field is not applied, this film scatters light incident on the film because the nematic liquid crystal in the liquid crystal droplets aligns along the capsule wall surface, while when an electric field is applied, the nematic liquid crystal Are considered to take two states of scattering and transmission, in which incident light is transmitted because they are aligned in the direction of the electric field.

[0004] Also, Japanese Patent Publication No. Sho 61-502128,
JP-A-62-2231 and JP-A-64-626
No. 15 discloses that a mixture of a polymerizable composition such as an epoxy and a low-molecular liquid crystal material is irradiated with ultraviolet light or heat to polymerize the polymerizable composition, thereby causing phase separation and causing liquid crystal droplets to be dispersed in the binder. It is disclosed that a liquid crystal element having a configuration dispersedly held in the liquid crystal device is manufactured. Further, Japanese Patent Laid-Open No. 2-5
No. 5787 discloses that in the above-described phase separation method by ultraviolet polymerization, the drive voltage is reduced by increasing the ratio of the low-molecular liquid crystal material used. Further, Japanese Patent Application Laid-Open Nos.
No. 137211 discloses that a low-molecular liquid crystal material and a high-molecular substance are dissolved in a common organic solvent, applied to a substrate, and the organic solvent is evaporated to cause phase separation. It is disclosed that a liquid crystal element dispersed and held is manufactured.

The liquid crystal-polymer composite films disclosed in the above publications do not require a polarizing plate, which is indispensable for a conventional liquid crystal display device. There is an advantage that rubbing treatment is not required, and therefore, the area of the element can be easily increased.

[0006]

However, these liquid crystal-polymer composite films have poor adhesion to a substrate, and particularly when a flexible material such as a polyethylene terephthalate film is used for the substrate, good adhesion is obtained. Sex was not obtained. As a countermeasure, it has been attempted to provide an adhesive layer or use an adhesive, but in these cases,
Although the adhesiveness is improved, there is a problem that the electro-optical characteristics are deteriorated.

An object of the present invention is to provide an electro-optical element having good adhesion between a liquid crystal-polymer composite film and a substrate. Another object of the present invention is to manufacture an electro-optical element having a large-area liquid crystal-polymer composite film by bonding a liquid crystal-polymer composite film and a substrate with good adhesion without using an adhesive or an adhesive layer. It is to provide a way to do it.

[0008]

According to the present invention, there is provided an electro-optical element comprising a liquid crystal-polymer composite film in which a low-molecular liquid crystal compound and a high-molecular compound are present in a phase-separated state between two substrates. In the optical element, two substrate surfaces in contact with the composite film are formed of a group selected from a glycidyl group and an isocyanate group.
A material having a reactive group capable of reacting with glycidyl in the composite membrane having a surface preliminarily coated and formed.
It is characterized by being chemically bonded to a polymer compound having a group selected from a group and an isocyanate group .

The method for producing an electro-optical element according to the present invention comprises a reaction
A material having a functional group on a pair of substrates;
On one coated surface of the substrate, the reactive group reacts with the reactive group.
High-molecular-weight compounds and low-molecular-weight liquid-crystal compounds having a bonding group
Reacts with the mixture or the reactive group to form a chemical bond
Apply a polymer compound having a group and a liquid crystal molecular structure.
The other application surface of the pair of substrates was contacted with the polymer compound.
Characterized in that it comprises a step of overlapping
You.

[0010]

Hereinafter, the present invention will be described in detail. The function of the liquid crystal-polymer composite film in the electro-optical element of the present invention is exhibited when the low-molecular liquid crystal and the high-molecular compound are phase-separated from each other. The form of the phase separation may be such that each droplet is dispersed and held, or a plurality of liquid crystal droplets may be aggregated. The shape of the liquid crystal droplet may be spherical or polyhedral as in the case where a polymer compound forms a wall on a thin film. Further, the liquid crystal may form a continuous phase.

The mode of phase separation of the liquid crystal-polymer composite film of the present invention is shown by a schematic diagram. FIG. 1A shows a low-molecular liquid crystal 1.
This is an example in which the amount of the polymer compound 2 is excessively used, and illustrates the liquid crystal-polymer composite film 3 in which the low-molecular liquid crystal 1 is dispersed in the polymer compound 2 in a microdroplet shape.
FIG. 1B shows an example in which low-molecular liquid crystal 1 and high-molecular compound 2 are used in substantially equal amounts, and illustrates a liquid crystal-polymer composite film 3 in which sponge-like phase separation is performed. FIG. 1C is an example in which the low-molecular liquid crystal 1 is used in excess of the amount of the high-molecular compound 2, and the liquid crystal-polymer composite in which the high-molecular compound 2 is separated into fibrous phases in the low-molecular liquid crystal 1 The membrane 3 is illustrated.

The substrate holding the liquid crystal-polymer composite film of the present invention is provided with electrodes, and has at least a surface formed of a material having a reactive group. Hereinafter, the substrate with electrodes is referred to as a “substrate” unless otherwise specified.

In the material having a reactive group that forms the substrate surface, the reactive group may be a reactive group having an active hydrogen such as a hydroxyl group, a carboxyl group, an amino group, an acid amide group, a mercapto group, or an alkali metal alcoholate group. ,
Magnesium halide group, epoxy group, propylene oxide group, ethylene sulfide group, propylene sulfide group, cyclohexabutane group, lactam group, lactone group,
Reactive groups such as oxazolidine group, ethyleneimine group, propyleneimine group and isocyanate group, and polymerizable groups such as unsaturated double bond are exemplified.

As a method of providing these reactive groups on the substrate surface, various reactive groups such as hydroxyl groups can be formed on the substrate surface by heating the substrate to a high temperature in an active oxygen or water vapor atmosphere or by plasma treatment. Substrate surface treatment method for forming,
A method of coating the polymer compound having a reactive group on the substrate surface, a method of adsorbing or coating the low molecular compound containing the reactive group on the substrate surface, and the like can be adopted.

As the high molecular compound having a reactive group coated on the substrate surface, the above high molecular compounds having various reactive groups are used. Specific examples thereof include polyvinyl alcohol and polyvinyl butyral. And a high molecular compound having an amino group or an amide group, such as polyallylamine, polyurethane and polyamide. Further, polymer compounds having various reactive groups used for a liquid crystal-polymer composite film described later can also be preferably used. In addition, low-molecular-weight compounds containing reactive groups that are adsorbed or coated on the substrate surface include amino groups, carboxyl groups, (meth)
Examples include silane coupling agents having an acrylic acid group or a vinyl group. It is also possible to convert the silane coupling agent having a halogen atom or a vinyl group into a hydroxyl group by adsorbing or coating and then subjecting the silane coupling agent to a hydrolysis treatment, which is preferred in the present invention.

The thickness of the layer containing a reactive group formed on the surface of the substrate is 1 molecular layer to 1 μm when formed by adsorption, and 1 layer when formed by coating.
It is preferably set in the range of nm to 10 μm.

A liquid crystal-polymer composite film is formed on the surface of the substrate, and in the present invention, the polymer compound constituting the liquid crystal-polymer composite film is used for the above-mentioned reactive compound existing on the substrate surface. It is characterized by being chemically bonded to a group. In the present invention, the polymer compound constituting the liquid crystal-polymer composite film is (1) a polymer compound having at least one or more reactive groups in at least a side chain, or at least one polymer capable of reacting with these polymer compounds. And (2) those formed by polymerizing one or more polymerizable compounds.
In any case, it exists in a state chemically bonded to a reactive group present on the substrate surface.

In the present invention, in order to form these high molecular compounds, a high molecular compound having a reactive group in a side chain may be prepared using a polymerizable compound in advance, or the high molecular compound may be prepared by adding the polymerizable compound to the substrate surface. And may be directly formed by polymerizing with. First, a case where a polymer compound having a reactive group in a side chain is prepared using a polymerizable compound in advance will be described. In this case, as the reactive group, for example, when an amino group, a carboxyl group, an alkali metal alcoholate group, a magnesium halide group, or the like is formed as the reactive group on the substrate surface, the reactive group contained in the polymer compound As the group, an epoxy group, a propylene oxide group, an ethylene sulfide group, an oxazolidine group, an ethylene imine group, a propylene imine group, or the like can be used, and a combination of these reactive groups is appropriately selected. Further, as the reactive group formed on the substrate surface, the reactive group described above,
When contained in the polymer compound, the reactive group contained in the polymer compound may be the above-described reactive group.
There may be a reactive group formed on the substrate surface. When a polymer compound having a reactive group in a side chain prepared by pre-polymerization is used, and a reactive compound is added as a third component in addition to the liquid crystal and the polymer compound, the surface of the substrate is It is preferable that the reactive group and the reactive group in the polymer compound are of the same type.

As a method for producing the above-mentioned polymer compound, a method of polymerizing the above-mentioned polymerizable monomer containing a reactive group, or a method of adding the above-mentioned reactive group to a reactive prepolymer typified by polyhydrogenated methylsiloxane. A method of causing an addition reaction of an addition-reactive compound containing is applied.

The method of producing the above-mentioned polymer compound by polymerization will be described in detail. A usual method of radical polymerization, ionic polymerization or photopolymerization of a monomer composition containing at least a polymerizable monomer containing a reactive group can be applied. . In this case, the polymer compound formed may be a homopolymer obtained from only the polymerizable monomer containing a reactive group or a copolymer with another polymerizable monomer containing no reactive group. You may.

Specific examples of these polymerizable monomers include:
(Meth) alkyl esters and derivatives of C ₁ -C ₃₀ acrylic acid, (meth) halogen-substituted alkyl esters of acrylic acid, (meth) acrylic acid dialkyl aminoethyl ester, polyethylene glycol mono (meth)
Acrylic esters, (meth) acrylic acid, (meth) acrylamide, vinyl acetate, styrene and its derivatives, (meth) acrylonitrile, ethylene, vinyl chloride, vinylidene chloride, vinylidene fluoride, vinylpyrrolidone, butadiene, isoprene, chloroprene, etc. can give. Further, as the polymerizable monomer having an epoxy group as a reactive group, glycidyl (meth) acrylate,
Glycidyl vinyl benzoate and the like. Furthermore, polymerizable monomers having active hydrogen as a reactive group include (meth) acrylic acid 2-hydroxyethyl ester, (meth) acrylic acid 3-hydroxypropyl ester, (meth) acrylic acid glycerin ester, and vinyl sulfonic acid. And monomers having active hydrogen such as (meth) acrylic acid and (meth) acrylamide described above. Incidentally, vinyl acetate or the like may be used as a polymerizable monomer, and the acetyl group may be converted to a hydroxyl group by hydrolysis after polymerization.

The polymer composing the liquid crystal-polymer composite film of the present invention is obtained by copolymerizing a polymerizable monomer having a substituent serving as a liquid crystal side chain component in a molecule (hereinafter referred to as a liquid crystal monomer). It is preferably formed from those that have been made.
In this case, the formed polymer compound itself does not have to exhibit liquid crystallinity, and is essentially different from a conventional side-chain type polymer liquid crystal. By copolymerizing the liquid crystalline monomer, anchoring between the low molecular liquid crystal and the polymer binder wall is remarkably reduced, and it can be expected that lower voltage driving can be realized. As the liquid crystalline monomer used in the present invention, a liquid crystalline compound bonded to a vinyl group, an acrylate group, a methacrylate group, or the like via an appropriate alkyl spacer. These are described, for example, in Makromol. Chem. p. 273, 179 (1
978), Eur. Polym. J. , P651, 18
(1982), Mol. Cryst, Liq. Crys
t. , 169, p167 (1989). Specific examples thereof include, for example, biphenyl, phenylbenzoate, cyclohexylbenzene, azoxybenzene, azobenzene, azomethine, phenylpyrimidine, diphenylacetylene, biphenylbenzoate, cyclohexylbiphenyl, and terphenyl. And cholesterol-based liquid crystal compounds are bonded to a vinyl group, an acrylate group, a methacrylate group, or the like via an appropriate alkyl spacer. These liquid crystal monomers need not be a single compound, and may be used in combination of two or more.

On the other hand, the production method by the addition reaction to the prepolymer will be described in detail. Using polyhydrogenated methylsilicone as a prepolymer, an addition reactive compound having an unsaturated double bond is added using a catalyst such as platinum. It is common. Usable addition-reactive compounds include, for example, alkene derivatives such as 1-propene, 1-butene and 1-hexene, and those having an active group include 2-propen-1-ol, -Hexene-1
-Alkenyl alcohol derivatives such as all.

The molecular weight of the polymer compound used in the present invention is not particularly limited, but is preferably selected in the range of 1 to 1,000,000, and more preferably in the range of 5 to 1,000,000.

In the present invention, when a liquid crystal-polymer composite film is formed on a substrate using a polymer compound having a reactive group in a side chain obtained as described above, a third component is A reactive compound capable of reacting with a reactive group present on the material surface and a reactive group present on a side chain of the polymer compound is added as necessary. As such a reactive compound, any compound can be used as long as it can react with the above-mentioned reactive group. For example, when the reactive group present on the substrate surface and the reactive group contained in the polymer have active hydrogen, a polyfunctional isocyanate compound, a polyfunctional epoxy compound, a polyfunctional propylene oxide compound, a polyfunctional Ethylene sulfide compound, polyfunctional propylene sulfide compound, polyfunctional cyclooxabutane compound, polyfunctional lactam compound, polyfunctional lactone compound, polyfunctional oxazolidine compound, polyfunctional ethyleneimine compound, polyfunctional propyleneimine compound,
Polyfunctional aldehyde compounds and the like, or melamine and its derivatives can be used.

Of the above compounds, polyfunctional isocyanate compounds are preferably used because of their high reactivity. Specific examples thereof include bifunctional isocyanate compounds such as hexamethylene diisocyanate, toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and 3,4'-dichlorophenyl diisocyanate;
Adducts of these bifunctional isocyanate compounds with polyols such as trimethylolpropane can be mentioned. Furthermore, a so-called blocked isocyanate-based compound that generates isocyanate at a certain temperature or higher can also be used. Examples of the polyfunctional epoxy compound include bisphenol A glycidyl ether and derivatives thereof. When the reactive group present on the substrate surface and the reactive group contained in the polymer compound are epoxy groups, monofunctional or polyfunctional amino compounds and carboxylic acid compounds can be preferably used.

The amount of the reactive compound that can be added as the third component is stoichiometrically equal to the reactive group present on the substrate surface and the reactive group contained in the polymer compound. Preferably, there is. By adding these third components, not only chemical bonding between the substrate surface and the polymer in the composite film, but also a cross-linking reaction of the polymer occurs, and the strength and electro-optical properties of the composite film are improved.

Next, as a method of forming a polymer compound in the present invention, a case where a polymerizable compound is directly formed by polymerizing on a substrate surface will be described. In this case, as the polymerizable compound, the polymerizable monomer used when the above-described polymer compound having a reactive group in the side chain is produced by a polymerization method can be used as it is, and the production method is also the same. However, in this case, it is necessary to select a polymerizable monomer having good compatibility with the liquid crystal in order to produce a polymer compound by polymerizing a solution in which the liquid crystal and the polymerizable monomer are mixed. Therefore, the polymerizable monomer is appropriately selected depending on the combination with the liquid crystal used.

The low-molecular liquid crystal constituting the liquid crystal-polymer composite film of the present invention is a nematic liquid crystal, a cholesteric liquid crystal,
Various liquid crystal materials, such as smectic liquid crystals and ferroelectric liquid crystals, used as general display materials or as electric field driven display materials can be used. Specifically, biphenyl, phenylbenzoate, cyclohexylbenzene, azoxybenzene, azobenzene, azomethine, terphenyl, biphenylbenzoate, cyclohexylbiphenyl, phenylpyrimidine, cyclohexylpyrimidine, cholesterol, etc. Of various liquid crystal compounds. These low-molecular liquid crystals are similar to commonly used liquid crystal materials.
The composition does not need to be composed of components, and may be composed of a plurality of components.

For the purpose of displaying by an electric field, it is preferable to use a liquid crystal compound having a positive dielectric anisotropy among the above low molecular liquid crystals. Depending on the LCD,
When the frequency of the applied voltage is higher than a certain value (crossover frequency), the dielectric anisotropy changes from positive to negative. However, it is needless to say that the above-mentioned liquid crystal can be used for two-frequency driving. Absent. In the present invention, the ratio of the low-molecular liquid crystal in the liquid crystal-polymer composite film is 35 to 95% by weight.
And it is preferably in the range of 60 to 90% by weight.

Next, a method for manufacturing an electro-optical element having the liquid crystal-polymer composite film of the present invention will be described. Note that the “substrate” used in the description of the following manufacturing method means that the surface of the substrate with electrodes is formed of a material having a reactive group.

In the case of the coating method, a polymer solution having a reactive group in a side chain previously synthesized with a liquid crystal and a reactive compound as a third component are dissolved in a common solvent to prepare a mixed solution. After applying this solution on the substrate and drying,
An electro-optical element having a liquid crystal-polymer composite film is manufactured by attaching an opposing substrate. In the case of using the polymerization method, a liquid crystal, a polymerizable composition, and a polymerization initiator are mixed together to prepare a uniform solution, and this solution is used as a cell composed of two counter electrode substrates having an appropriate gap in advance. After encapsulating in one or applying on one substrate, the other substrate is overlapped with an appropriate gap, and then the polymerizable composition is polymerized by heat, light, etc. An optical element is manufactured. In this case, a group having an unsaturated double bond such as a (meth) acrylic acid group or a vinyl group is formed as a reactive group on the substrate.

As shown in FIG. 2, the form of the electro-optical element having the liquid crystal-polymer composite film manufactured as described above is formed on two substrates 4 and 5 in the same manner as a normal liquid crystal display element. Those having a sandwiched structure are preferred. FIG. 2 shows that the liquid crystal 1 to which a voltage is applied from the power supply 6 to the substrates 4 and 5 is a composite film 3.
In the figure, a state of being oriented in the direction of the electric field is shown. As the substrate material, a transparent electrode such as a glass substrate or a plastic film having an ITO-coated surface, an aluminum-deposited film, a gold-deposited film, a silver-deposited film, a copper-plated film, or the like is preferably used. At this time, it is also preferable to make the distance between the electrode substrates constant by using an appropriate spacer material, similarly to the related art.

The liquid crystal-polymer composite film in the electro-optical element of the present invention can be applied as it is as a display material, but various compounds may be added for the purpose of further improving contrast, stability and durability. Can be. For the purpose of improving the contrast, various dichroic dyes such as anthraquinone, styryl, azomethine, and azo can be used. In that case, it is preferable that the dichroic dye is basically mixed (compatible) with the liquid crystal in the composite film and is incompatible with the polymer compound. In addition, antioxidants, ultraviolet absorbers, various plasticizers, and the like are also preferably used from the viewpoint of improving stability and durability.

In the present invention, since the substrate holding the liquid crystal-polymer composite film and the polymer compound constituting the liquid crystal-polymer composite film are directly reacted and chemically bonded, the substrate surface and the liquid crystal-polymer composite film are bonded to each other. Adhesion with the polymer composite film becomes strong. Therefore, even if a flexible material is selected for the substrate,
An element using a liquid crystal-polymer composite film having sufficient adhesive strength can be obtained.

[0037]

The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 (Surface coating of substrate) Two polyethylene terephthalates with ITO (PE
T) Polyvinyl alcohol is applied to each surface of the film using a blade coater, dried, and dried to about 0.
A film was formed to a thickness of 5 μm.

Example 2 (Surface Coating of Substrate) Each surface of two PET films with ITO was
Aminopropyltriethoxysilane is applied using a blade coater, and dried under a nitrogen atmosphere to about 0.1 μm
To a thickness of

Example 3 A mixture of 0.5 g of 2-hydroxyethyl methacrylate and 9.5 g of ethyl methacrylate was mixed with AIBN (2,2 ').
-Azobisisobutyronitrile) as a polymerization initiator. The weight average molecular weight (in terms of polystyrene by GPC) of the obtained polymer compound is about 300,000,
As a result of NMR analysis, the composition of the copolymer was almost the same as at the time of preparation. 200 mg of the obtained high molecular compound, 200 mg of low-molecular liquid crystal (E-44, manufactured by BDH) and polyfunctional isocyanate (trimethylolpropane-HDI adduct) (Coronate HX, manufactured by Nippon Polyurethane) 15
mg was dissolved in toluene, and the resulting solution was coated on the PET film with ITO obtained in Example 1 using a blade coater and dried to obtain a film thickness of about 10%.
A μm liquid crystal-polymer composite film was formed. Example 1
Another one of the PET films with ITO obtained in was bonded together as a counter substrate and reacted at 50 ° C. for 24 hours. The resulting composite film was visually uniformly clouded. In addition, when observed with a polarizing microscope, the low-molecular liquid crystal formed fine domains separated from each other.

Example 4 0.5 g of glycidyl methacrylate and 9.5 g of ethyl methacrylate were mixed and copolymerized using AIBN as a polymerization initiator. The obtained polymer compound had a weight average molecular weight (in terms of polystyrene by GPC) of about 300,000. As a result of NMR analysis, the composition of the copolymer was almost the same as that at the time of preparation. 200 mg of the obtained polymer compound,
200 mg of low molecular liquid crystal (manufactured by BDH, E-44) and hexamethylenediamine 10 which is a polyfunctional amino compound
mg was dissolved in toluene, and the resulting solution was coated on the PET film with ITO obtained in Example 2 using a blade coater and dried to obtain a film having a thickness of about 10 μm.
m of a liquid crystal-polymer composite film was formed. Further, another one of the PET films with ITO obtained in Example 2 was adhered as a counter substrate and reacted at 60 ° C. for 24 hours. The resulting composite film was visually uniformly clouded. In addition, when observed with a polarizing microscope, the low-molecular liquid crystal formed fine domains separated from each other.

Comparative Example 1 In Example 3, a liquid crystal-polymer composite film was formed in the same manner as in Example 3 except that the PET film with ITO not subjected to the substrate treatment of Example 1 was used and no isocyanate was added. Produced.

Comparative Example 2 In Example 4, a liquid crystal-polymer composite was prepared in the same manner as in Example 4 except that the PET film with ITO not subjected to the substrate treatment of Example 2 was used and hexamethylenediamine was not added. A film was prepared.

Comparative Example 3 In Example 3, as a PET film with ITO,
A liquid crystal-polymer composite film was produced in the same manner as in Example 3 except that a double-sided adhesive tape (manufactured by Sumitomo 3M, thickness 25 μm) was attached to each surface, and no isocyanate was added.

Evaluation Example 1: Adhesion The adhesion of the samples of Examples 3 and 4 and Comparative Examples 1 to 3 was evaluated by the following method. The PET film with ITO was cut to make the area (adhesion area) of the liquid crystal-polymer composite film 1 cm ² (1 cm × 1 cm). Next, one side of the PET film with ITO was fixed, a spring balance was attached to the other side, and the tensile strength was measured by pulling. The results are shown in Table 1 below.

Evaluation Example 2: Electro-optical properties The adhesiveness of the samples of Examples 3 and 4, and Comparative Examples 1 to 3 was evaluated by the following method. White light from a 50 W halogen lamp was converted into parallel light through a lens, and a 100 Hz rectangular wave AC voltage was applied to the sample while directly entering the sample. The transmitted light intensity at the maximum spread angle of about ± 10 ° transmitted through the sample was measured while changing the applied voltage. The following parameters were determined from the obtained applied voltage-transmitted light intensity curve (FIG. 3).

[0046]

Driving voltage: V ₉₀ = transmitted light intensity is 90% of the total variation
The voltage at which it changes. Contrast: CR = T _max / T _min (where T _max and T _min indicate the maximum value and the minimum value of the transmittance T, respectively)

The results of the above evaluations are shown in Table 1 below.

[Table 1]

As can be seen from Table 1, when the liquid crystal-polymer composite films of Examples 3 and 4 of the present invention were used, the adhesiveness was significantly improved as compared with the case of the comparative example.
In the case of the liquid crystal-polymer composite film provided with the adhesive layer of Comparative Example 3, the electro-optical characteristics were clearly deteriorated, whereas the liquid crystal-polymer composite films of Examples 3 and 4 of the present invention were used. In the case of having a film, it is clear that the electro-optical characteristics are not deteriorated and, on the contrary, the characteristics are improved.

[0049]

According to the electro-optical device having the liquid crystal-polymer composite film of the present invention, (1) the adhesion to the substrate is higher than that of the conventional liquid crystal-polymer composite film, and (2)
It has the effect of increasing the mechanical strength of the liquid crystal-polymer composite film. Further, the liquid crystal-polymer composite film in the present invention,
In addition to the advantage that a bright display is possible without the need for a polarizing plate, it also exhibits the above-mentioned excellent effects, so it can be applied not only to dimming elements but also to display elements, light modulation elements, optical shutters, and memory elements. Large-screen display element (transmission and reflection mode), which was difficult to put into practical use in the past
Application to is also possible.

[Brief description of the drawings]

FIG. 1 is a schematic view of a liquid crystal-polymer composite film according to the present invention.

FIG. 2 is a schematic configuration diagram of an electro-optical element using a liquid crystal-polymer composite film according to the present invention.

FIG. 3 is a graph showing the relationship between the applied voltage and the transmittance of a liquid crystal-polymer composite film.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Low molecular liquid crystal, 2 ... Polymer compound, 3 ... Liquid crystal-polymer composite film, 4 and 5 ... Substrate, 6 ... Power supply.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-56-55922 (JP, A) JP-A-4-319911 (JP, A) JP-A-3-4212 (JP, A) JP-A-2- 310521 (JP, A) JP-A-6-102493 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G02F 1/1333

Claims (5)

(57) [Claims] 1. An electro-optical element having a liquid crystal-polymer composite film in which a low-molecular liquid crystal compound and a high-molecular compound are present in a phase-separated state between two substrates.
The substrate surface is selected from glycidyl groups and isocyanate groups.
A material having a reactive group capable of reacting with the selected group is coated in advance.
A fabric- formed surface, wherein the reactive groups are present in the composite membrane.
Groups selected from glycidyl groups and isocyanate groups
An electro-optical element, which is chemically bonded to a polymer compound having the same . 2. A material having a reactive group is provided on a pair of substrates.
Applying, on one application surface of the pair of substrates, the reaction
A polymer compound having a group that chemically reacts with a reactive group
A mixture comprising a low-molecular liquid crystal compound or the reactive group
Polymers with correspondingly chemically bonded groups and liquid crystal molecular structures
A compound is applied, and the other application surface of the pair of substrates is
A step of superimposing the polymer compound so as to be in contact therewith.
A method for producing an electro-optical element provided with a liquid crystal-polymer composite film in which a liquid crystal compound and a polymer compound are present in a phase-separated state. 3. The method for producing an electro-optical element according to claim 2, wherein the polymer compound is subjected to a crosslinking reaction. 4. The method according to claim 2, wherein the reactive compound is a polyfunctional isocyanate compound. 5. The method according to claim 2, wherein one of the material forming the surface of the substrate and the reactive compound has an epoxy group as a reactive group.