JPH0854611A - Liquid crystal/polymer composite film type display element and its production - Google Patents

Abstract

PURPOSE:To obtain a liquid crystal display element having excellent display characteristics in which no problem of peeling of substrates is caused, pattern coating can be easily performed and no air bubble is included in the liquid crystal/polymer composite film, by forming the liquid crystal/polymer composite film in a pattern shape and forming a hot-melt adhesive layer to adhere two substrates around the liquid crystal/polymer composite film. CONSTITUTION:This liquid crystal/polymer composite film type display element consists of two glass or film substrates 2, 2 at least one of which is transparent, and transparent conductive films 3, 3 which act as electrodes on the inner surfaces of substrates 2, 2. A liquid crystal/polymer composite film 4 having dispersion of a liquid crystal in the polymer is held between these transparent conductive films 3, 3. A hot-melt adhesive layer 5 is formed in the space in the areas of the liquid crystal/polymer composite film 4. The hot-melt adhesive layer is generally formed into any shapes according to the purpose such as plural parallel lines, rectangles, polygons, squares, ovals and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device having a liquid crystal / polymer composite film having an electric field and thermal response and capable of displaying and recording information, and a manufacturing method thereof. The liquid crystal display device of the present invention includes a light control panel, a display, a rewritable display / recording medium (card, OH).
It can be widely applied as a constituent material such as P).

[0002]

2. Description of the Related Art Conventionally, liquid crystal display devices (liquid crystal displays) have been widely used for wristwatches, calculators, personal computers, televisions, etc. as a display medium for characters and images because of their features such as low power consumption, light weight and thin shape. It is used. Also, a rewritable display medium using a smectic liquid crystal has been proposed. In general TN and STN liquid crystal displays, liquid crystal is enclosed in a liquid crystal cell in which a glass plate having a transparent electrode on which an alignment film is formed is provided with a predetermined seal, and then sandwiched by polarizing plates from both sides. It is a thing.

However, the above-mentioned conventional liquid crystal display (1) requires two polarizing plates, so that the viewing angle is narrow and the brightness is insufficient. Therefore, a backlight with high power consumption is required. There is a problem that (2) cell thickness dependency is large and it is difficult to increase the area, and (3) the structure is complicated and it is difficult to enclose the liquid crystal in the cell, so that the manufacturing cost is high.
There are limits to the weight reduction, thinning, large area, low power consumption and cost reduction of liquid crystal displays. As a liquid crystal display device that solves such problems, application of a liquid crystal / polymer composite film in which liquid crystal is dispersed in a polymer matrix is expected,
The research and development has become active.

The following methods can be mentioned as main methods for producing such a liquid crystal / polymer composite film. A method of impregnating a polymer porous body with liquid crystal. A method of casting and drying an emulsion in which a liquid crystal is dispersed in an aqueous solution of polyvinyl alcohol (Table 5
8-501631). A method of casting a solution in which a liquid crystal and a polymer are dissolved in a common solvent, and causing the liquid crystal and the polymer to undergo phase separation as the solvent is removed (see Japanese Patent Publication No. 61-502128). A method of polymerizing a monomer in a mixture of liquid crystal and a monomer to obtain a phase-separated structure of the liquid crystal and the polymer.
-502128). Among the above methods, the method of is advantageous in that it is easy to manufacture, it is easy to control the structure and the film thickness, and it is possible to increase the area. Has been converted.

In the liquid crystal / polymer composite film obtained by the above method, the liquid crystal is dispersed in the matrix resin in the form of fine spheres. This is because when no voltage is applied, the liquid crystal molecules are aligned along the spherical wall of the matrix, and due to the birefringence of the liquid crystal molecules and the extraordinary refractive index of the liquid crystal at this time and the refractive index mismatch between the polymer matrix. The incident light is scattered inside the liquid crystal sphere and at the interface. Therefore, the liquid crystal / polymer composite film becomes opaque.

[0006]

By using a liquid crystal / polymer composite film, a polarizing plate is not required, and a bright liquid crystal display device with high light utilization efficiency can be obtained, and a coating method can be used for manufacturing, and the cost is low. Although it seems to be an extremely advantageous method due to the possibility of conversion, there are various problems in actual manufacturing. In particular, since the coating suitability of the coating liquid itself is not preferable, there is a problem that a uniform liquid crystal / polymer composite film having excellent characteristics cannot be obtained depending on the coating method. The liquid crystal dispersion can be applied by a blade coating method, but the edge of the formed coating film, the beginning of coating,
There is also a problem in terms of cost because unevenness in thickness at the end of coating occurs and an expensive liquid crystal dispersion is additionally used. Furthermore, it is impossible to form the liquid crystal dispersion in a pattern by the blade coating method. On the other hand, if the screen printing method is used, pattern coating is possible,
There is a problem that air bubbles are mixed in the liquid crystal dispersion when the liquid crystal dispersion passes through the screen mesh.

A liquid crystal dispersion solution obtained by mixing an aqueous solution of a water-soluble polymer substance with liquid crystal and stirring the liquid crystal component contains 80 to 80% of the liquid crystal component in order to improve electro-optical characteristics such as reduction of driving voltage.
This is done by reducing the amount of the polymer substance to 90% by weight as much as possible, but since the liquid crystal dispersion has the thixotropic property peculiar to the aqueous solution of the water-soluble polymer substance, the removal of air bubbles in the mixture is eliminated. Will be difficult. In a product such as a display device, the presence of air bubbles is a fatal problem, and the air bubbles mixed in at the time of application cannot be removed, and it is extremely difficult to commercialize the product. Therefore, it is difficult to satisfy the requirement of uniforming the entire voltage characteristics of the liquid crystal optical element.

On the other hand, various materials are used as a polymer matrix constituting the liquid crystal / polymer composite film, but the liquid crystal in the liquid crystal / polymer composite film seeps out from the liquid crystal / polymer composite film. There is a problem that the strength of the adhesive layer that adheres the substrate is reduced, and the substrate is easily peeled off. In addition, when a liquid adhesive layer is formed around the patterned liquid crystal / polymer composite film, there is a problem that the adhesive permeates the liquid crystal / polymer composite film and adversely affects the liquid crystal / polymer composite film. Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art, no problem of peeling of a substrate, easy pattern coating, no waste of liquid crystal dispersion liquid, and liquid crystal / polymer in a liquid crystal display device. It is an object of the present invention to provide a liquid crystal display device having excellent display characteristics in which bubbles are not contained in the composite film.

[0009]

The above objects can be solved by the present invention described below. That is, the present invention provides a liquid crystal / polymer composite film type display device in which a liquid crystal / polymer composite film is sandwiched between two substrates each having an electrode on at least one substrate, and the liquid crystal / polymer composite film is patterned. 2 is formed around the liquid crystal / polymer composite film formed in a pattern.
A liquid crystal / polymer composite film type display device is characterized in that a heat-fusible adhesive layer for adhering one substrate is formed. Further, the present invention provides a method for manufacturing a liquid crystal / polymer composite film type display device, which comprises a liquid crystal / polymer composite film sandwiched between two substrates each having an electrode on at least one substrate. Forming a plurality of compartments partitioned by partition walls made of a heat-fusible adhesive, filling the compartments with a liquid crystal emulsion, and drying, and then stacking and heating the electrode substrates to bond the two substrates together. And a liquid crystal / polymer composite film type display device. Furthermore, the present invention provides a method for producing a liquid crystal / polymer composite film type display device comprising a liquid crystal / polymer composite film sandwiched between two substrates each having an electrode on at least one of the substrates. Forming a plurality of compartments partitioned by partition walls made of a heat-fusible adhesive, forming a release layer on the partition walls, filling the partition chambers with a liquid crystal emulsion, and drying, and then stacking opposite substrates on top of each other. A method of manufacturing a liquid crystal / polymer composite film type display device, which comprises heating and adhering two substrates.

[0010]

By using the heat-fusible adhesive which is solid at room temperature as the partition wall, the exudation of liquid crystal into the adhesive and the adverse effect of the adhesive on the liquid crystal / polymer composite film are suppressed. Further, by using the heat-meltable adhesive as the partition wall,
The liquid crystal / polymer composite film can be easily formed into a pattern, the liquid crystal dispersion is not wasted, stable coating is possible, there is no coating unevenness, and air bubbles are mixed in the liquid crystal / polymer composite film in the liquid crystal display device. Can be prevented. Furthermore, by adding a dichroic dye to the liquid crystal / polymer composite film and applying the dichroic dye by screen printing using a metal mask, it is possible to separately paint each pixel, so that arbitrary color display can be performed. It is easy, and a reflective color display panel which cannot be expressed by the conventional TN type or STN type can be supplied at low cost.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the preferred embodiments. An example of the constitution of the liquid crystal / polymer composite film type display element of the present invention is shown in FIG. The liquid crystal / polymer composite film type display element 1 of the present invention has transparent conductive films 3 and 3 acting as electrodes inside two substrates 2 and 2 such as glass or film, at least one of which is transparent, A liquid crystal / polymer composite film 4 in which a liquid crystal is dispersed and held in a polymer matrix is sandwiched between the transparent conductive films, and heat fusion bonding is performed in a gap between regions of the liquid crystal / polymer composite film 4. The adhesive layer 5 is formed. As another aspect, when a voltage is applied by an external charge such as corona charging, only one of the substrates needs to have the transparent conductive film.

The heat-fusible adhesive layer generally has a plurality of parallel line shapes, quadrilateral shapes, polygonal shapes, quadrangular shapes, oblong shapes, etc.
It can be formed into a shape according to the purpose. For example, in the case of displaying characters or patterns of an appropriate size, it may be sufficient to form the heat-fusible adhesive layer only on the outer periphery of the display unit individual unit. When the layer spacing is too large, the regions may be arbitrarily distinguished or columnar or plate-shaped independent walls may be provided, and the shape thereof is not particularly limited. However, from the viewpoint of coating workability of the liquid crystal dispersion, it is preferable that the heat-fusible adhesive layer of any independent shape is continuously provided.

The method for forming the heat-fusible adhesive layer may be either an optical method or a printing method, but the optical method is preferable in order to obtain a high quality product. That is, a mold is formed in advance with a resist or the like, and a heat-sealable adhesive material is filled,
A method of removing the mold, or a method of applying a heat-fusible adhesive material on the entire surface and patterning by a photolithography method can be considered. Further, a screen printing method is generally used as a printing method, and the printing method cannot form a thin line as much as an optical method, but it can form a heat-fusible adhesive layer by a simple operation. There are advantages.

When the heat-fusible adhesive layer is water repellent, the thickness of the heat-fusible adhesive layer is the dry thickness of the liquid crystal / polymer composite film (generally 3 to 15 μm). It is preferable to set it about 10% lower. Further, the width of the heat-fusible adhesive layer can be arbitrarily changed depending on the shape of the display portion, but the space between the heat-fusible adhesive layers forming the display portion is too wide, and the heat-melting adhesive layer is also melted in the display portion. When the adhesive adhesive layer is provided, a width that can withstand the squeegee pressure at the time of applying the liquid crystal emulsion is required, but if the width is too wide, the heat-adhesive adhesive layer becomes conspicuous and the appearance becomes poor. ˜50 μm is preferred.

It is also possible to form a peeling layer on the heat-fusible adhesive layer, fill the liquid crystal emulsion, and peel the peeling layer to bond it to the counter electrode substrate. The peeling layer acts as a weir when the gap between the heat-fusible adhesive layers is filled with the liquid crystal emulsion. Since the volume of the liquid crystal emulsion decreases when it is dried and the thickness of the coating layer decreases, a peeling layer having a thickness equal to the thickness of the decrease is formed so that the reduced thickness becomes equal to the thickness of the heat-melting adhesive layer. It is preferable. Thereby, the thickness of the liquid crystal / polymer composite film and the thickness of the heat-fusible adhesive layer can be made the same.

As the material for forming the heat-fusible adhesive layer used in the present invention, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-acrylate copolymer, polyamide resin, polyester resin, Cellulose derivatives, atactic polypropylene, etc. are used. Further, as the material for forming the release layer used when forming the release layer, it has peelability and does not attack the film surface of the heat-fusible adhesive layer with a solvent or the like when forming the release layer, It is possible to use a film such as polyethylene terephthalate, a thermosetting resin, an ionizing radiation curable material, a material having a high water repellent property, for example, a resin having a polydimethylsiloxane skeleton or a fluororesin.

As the method for forming the release layer, the heat-fusible adhesive layer is laminated with a film in which openings having a pattern corresponding to that of the heat-fusible adhesive layer are laminated in advance, the screen-printing method and the photolithography method. There is a method of forming it on the agent layer. The size of the aperture of the film does not have to be completely the same as the compartment formed by the heat-sealable adhesive layer, and the compartment formed by the heat-sealable adhesive layer is filled with liquid crystal emulsion. It is enough if there are enough holes. In this case, the volume of the liquid crystal emulsion is reduced by the thickness of the film and the size of the aperture. This has an advantage that it can sufficiently cope with the case where there is only a film having a limited thickness, and that it can be easily aligned with the heat-fusible adhesive layer.

The liquid crystal used in the present invention is not particularly limited, and any of nematic liquid crystal, smectic liquid crystal, cholesteric liquid crystal and the like can be used, and a liquid crystal suitable for the electro-optical effect required for the device can be used as a wall. Used in combination with materials. In addition, a dichroic dye may be mixed in the liquid crystal used for the purpose of improving the contrast ratio and coloring in the case of forming an element. The dichroic dye used for coloring may be a guest-host type that is generally used in TN and STN type liquid crystal displays, or a dye for liquid crystal / polymer composite film. Good. However, it is preferable that the solubility in the liquid crystal is large, the solubility in the polymer is small, the dichroic ratio is large, and the absorption when a voltage is applied is small. There is a need to.

When the amount of the dye added is too large, the amount of the dye dissolved in the polymer increases, and color residue is generated when a voltage is applied, which is not preferable. On the other hand, if the amount of the dye is too small, the difference in light absorption between when voltage is applied and when voltage is not applied becomes small, and the effect of improving the contrast is not sufficient. Therefore, 0.1 to the liquid crystal used
It is preferably used in the range of 5% by weight. Furthermore 1-
It is preferably used in the range of 3% by weight. Further, the polymer matrix can be colored, and in that case, it is preferable that a dichroic dye that absorbs light which is not absorbed by the dye contained in the matrix is added to the liquid crystal particles. Further, the liquid crystal particles may be encapsulated.

In this case, the dichroic dye in the liquid crystal changes its molecular direction according to the alignment of the liquid crystal molecules by the electric field, so that the light absorption characteristic of each pixel changes depending on whether or not a voltage is applied. When the absorption of the dichroic dye is sufficiently low, the pixel shows the color due to the dye in the matrix, and when the absorption of the dichroic dye is sufficiently high, the pixel is separated from the dichroic dye and the dye in the matrix. Depending on the color mixture, for example, black is shown. It is necessary to avoid the dichroic dye in the liquid crystal from coloring even the matrix layer because it lowers the contrast of the displayed image.
Therefore, it is desirable that the liquid crystal particles are encapsulated.

The dichroic dye in the liquid crystal may be different for each liquid crystal / polymer composite film in each region for the purpose of improving chromaticity characteristics, improving light utilization efficiency, improving contrast and the like. . In this case, according to the present invention, it is possible to easily paint different colors by screen printing using a metal mask. That is, by aligning a metal mask having an opening in a necessary compartment with the heat-fusible adhesive layer and filling the compartment with the liquid crystal emulsion through the opening of the mask, it is possible to separately paint. Become. The amount of liquid crystal used is such that the weight ratio of matrix resin / liquid crystal is 5/95 to 50.
When the amount of liquid crystal used is too small, not only is the transparency insufficient when a voltage is applied, but also a large amount of voltage is required to bring the film into a transparent state. On the other hand, if the amount of liquid crystal used is too large, not only the scattering (turbidity) when no voltage is applied is insufficient, but also the strength of the film decreases, which is not preferable.

As a method for dispersing the liquid crystal in the aqueous matrix resin solution, a mixing method using various stirring devices such as an ultrasonic disperser or a film emulsification method (Tadao Nakajima, Masataka Shimizu, PHARM) is used.
A dispersion method such as TECH JAPAN Vol. 4, No. 10 (1988)) is effective. The size of the liquid crystal emulsion particles depends on the dispersion method used, but the liquid crystal particles have a diameter of 0.5 to 7.0 μm and an average particle diameter of 0.5.
It is preferable that it is ˜5.0 μm. Here, the average particle diameter of the liquid crystal is also represented by the diameter. In order to make the particle diameter of the liquid crystal emulsion uniform, it is most preferable to use the above-mentioned film emulsification method in which the particle diameter can be controlled by the pore diameter of the porous glass used.

PVA (polyvinyl alcohol) is preferably used as the matrix resin in which the liquid crystal is dispersed, but gelatin, acrylic acid copolymer, water-soluble alkyd resin or the like can be used as long as it can be dispersed or dissolved in water. When PVA having a low degree of saponification is used when PVA is used as the matrix resin, the PVA itself has a capability as a surfactant, so that a liquid crystal emulsion can be favorably produced without using any other surfactant. You can Further, in the present invention, it is more preferable to use the liquid crystal in an encapsulated form in order to prevent the liquid crystal from seeping out.

The liquid crystal microencapsulation method can use a general microencapsulation technique applied to other materials. The general microencapsulation method includes a chemical preparation method, a physicochemical preparation method, and a physical / mechanical preparation method. As the chemical preparation method, there are an interfacial polymerization method using a synthetic reaction, an in situ polymerization method, and an in-liquid hardening coating method that causes a change in physical properties of a polymer. The interfacial polymerization method is a method in which a water-soluble monomer and an oil-soluble monomer are selected as two kinds of monomers that undergo polycondensation or polyaddition reaction, and either of them is dispersed and reacted at the interface. in s
The in situ polymerization method is a method in which a reactant (monomer, initiator) is supplied from one of the inside and the outside of the core material to cause the reaction on the surface of the capsule wall film. The in-liquid hardening coating method (orifice method) is a method of encapsulating a core material with a wall film agent in advance and then hardening the wall film in a hardening liquid.

The physicochemical preparation method includes a coacervation method utilizing phase separation, an interfacial precipitation method (concentration method in liquid, drying method in liquid, secondary emulsion method) and a melt dispersion method. Further, the coacervation method can be used in an aqueous solution system or an organic solvent system. In an aqueous solution system, a simple coacervation method in which phase separation is caused by a decrease in solubility and a complex coacervation method in which phase separation is caused by electrical interaction can be used. The organic solvent system utilizes the phase separation phenomenon due to changes in solubility and temperature.
The interfacial precipitation method is a method capable of encapsulation under mild conditions without violent reaction or abrupt pH change. For example, after an aqueous solution in which a liquid crystal core material is dispersed is dispersed in a solvent solution of a hydrophobic polymer. Further, it is dispersed in a protective colloid solution. The melt dispersion method uses a wax-like substance such as wax or polyethylene as a partitioning agent, and is a method in which the core material is dispersed in a liquid together with the wax-like substance by heating and then cooled.

Spray as a physical / mechanical production method
Drying method, air suspension coating method, vacuum vapor deposition coating method, etc. can be mentioned, but since the liquid crystal that is the core material is a liquid at room temperature, it is necessary to create an emulsion that adjusts its size, so making a liquid crystal capsule Not legal. Among the various methods described above, the most preferable method is the in situ polymerization method because the particle size is easily controlled and the tolerance of the polymer material forming the capsule wall is high. Specifically, the liquid crystal, the monomer, and the polymerization initiator are dispersed in an aqueous solution in which a surfactant or a protective colloid is dissolved, and then heat-polymerized to form a capsule wall, and the liquid crystal is contained in the microcapsules. A method of obtaining liquid crystal microcapsules is used.

The monomer preferably used in the above method is a monomer having a polymerizable unsaturated group ((meth) acryloyl group, vinyl group, allyl group, etc.), for example,
(Meth) acrylic acid ester, styrene, butadiene,
Urethane acrylate, epoxy acrylate, etc. can be used. As the polymerization initiator used in the above method, an initiator used in general heat polymerization can be used, for example,
Examples thereof include azobisisobutyronitrile, azobis2-methylbutyronitrile, azobis (2,4-dimethylvaleronitrile) and the like. 100% by weight of monomer
On the other hand, it is about 0.5 to 5.0% by weight.

As the surfactant or protective colloid used in the above method, partially saponified polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, polyethylene glycol, sodium polystyrene sulfonate, poly (2-sulfoethyl methacrylate), poly (2-acryloyloxyethyltrimethylammonium chloride) or the like is used. The surfactant or protective colloid is preferably added in an amount of 0.5 to 10.0% by weight based on 100% by weight of water.
Also in the case of microencapsulation, the dispersion method is the same as above, and as a method of dispersing a liquid crystal in which a monomer, a polymerization initiator and, if necessary, an additive are dispersed in the aqueous solution, ultrasonic dispersion is performed as described above. Dispersion is performed by a mixing method using various stirring devices such as a machine or a dispersion method such as a film emulsification method.

The electrode substrate used in the present invention may be the same as the electrode substrate used in the conventionally known liquid crystal display element,
For example, the following are exemplified. At least one of the electrode substrate and the counter electrode substrate is a transparent conductive substrate such as a glass substrate with ITO. Others, SnO2
A transparent conductive material such as a ZnO-based or ZnO-based transparent conductive material may be attached to a transparent substrate. In addition to the glass substrate, the substrate may be a polymer film, for example, a transparent film made of a resin such as polyethylene terephthalate, polyarylate or polyether sulfone. On the other hand, in the case of an opaque conductive substrate, its electrode is also required to function as a reflection plate, and therefore, for example, a substrate provided with an aluminum reflection electrode is preferable. Of course, the substrate itself may be glass, a polymer film or another. In the present invention, since two substrates are heat-laminated with a heat-fusible adhesive, at least one substrate is preferably a film.

Next, a method of manufacturing a liquid crystal / polymer composite film type display device of the present invention will be described with reference to the process diagram of FIG. In the first step, as shown in FIG. 2A, a pattern of the heat-fusible adhesive layer 5 is provided on the transparent conductive film 3 on one substrate 2 by, for example, a screen printing method. In the subsequent second step, as shown in FIG. 2B, after the liquid crystal emulsion 6 from which air bubbles have been sufficiently removed is gently poured into a compartment made of a heat-fusible adhesive layer, a soft metal or hard metal is used. The surface of the liquid crystal emulsion is flattened by using a squeegee 7 made of rubber or the like.

Further, in the third step, after drying at room temperature or at a temperature that does not affect the liquid crystal emulsion or the liquid crystal-containing microcapsules, the other conductive substrate having the transparent conductive film is placed on the liquid crystal / polymer composite film. 1 and then heated at a temperature at which the heat-fusible adhesive melts and bonds,
A liquid crystal / polymer composite film type display device having the structure shown in is obtained. The present method is suitably used when a liquid crystal emulsion is repelled when a compartment formed of a heat-fusible adhesive layer is filled with the liquid crystal emulsion, and a volume reduction amount of the liquid crystal emulsion during drying is raised.

The filling of the liquid crystal emulsion into the compartment made of the heat-fusible adhesive layer in the second step is as follows.
It can also be performed using the electrodeposition method. In the formation method by the electrodeposition method, the thickness of the liquid crystal / polymer composite film can be controlled by controlling the electrodeposition time, which can be said to be a more preferable method of the present invention. The electrodeposition method referred to here is to dispose a main electrode serving as a coating substrate and a counter electrode in an electrodeposition liquid and to energize the electrodeposition liquid to electrically remove the solid content (liquid crystal microcapsules) in the electrodeposition liquid from the main electrode. Is a method of adsorbing or depositing on a substrate to form a coating film.

In the electrodeposition method, when an ITO substrate or the like is used as the main electrode for the anode, in cation electrodeposition, the crystal of the conductive film on the substrate surface is altered by the neutralizing agent which is an acidic compound during electrodeposition, resulting in a blackish brown color. It is preferable to use the anion electrodeposition method because it becomes a high resistance opaque substance. In the present invention, a substrate to which a transparent conductive material such as ITO is attached is used regardless of whether the substrate is transparent or opaque.
This is convenient because the TO or the like can be patterned in advance and the coating film can be electrodeposited only on the necessary regions. When cationic electrodeposition is used, it is preferable to use a mirror-finished stainless steel substrate that is not attacked by acidic compounds as the cathode that is the main electrode. In this case, the stainless steel substrate can be used as it is as the reflective electrode, but an electrodeposition coating film formed of an adhesive or an adhesive may be transferred onto another conductive substrate. In the latter case, there is an advantage that the main electrode can be used many times. With this transfer method,
It can be used in the present invention regardless of cation electrodeposition and anion electrodeposition.

The electrodeposition liquid used in the electrodeposition coating method is obtained by dispersing and dissolving the liquid crystal-containing microcapsules in an aqueous medium together with the binder resin having an ion-dissociative group, and adding an appropriate neutralizing agent. The liquid crystal-containing microcapsules contain a surfactant, an unreacted encapsulating agent, water, etc., which are unnecessary as a light modulation material.
It is also possible to perform operations such as centrifugal sedimentation, atmospheric drying, solvent replacement, and dry concentration.

As the binder resin having an ion-dissociable group, as a polymer for anion electrodeposition, an adduct of natural drying oil and maleic acid, an alkyd resin having a carboxyl group introduced, an adduct of epoxy resin and maleic acid is used. , A polybutadiene resin having a carboxyl group introduced, a copolymer of acrylic acid or methacrylic acid and its ester, etc. are used, and another polymer or an organic compound having a functional group is added to the polymer skeleton depending on the characteristics of the electrodeposition film. It may be introduced. When transparency is required, acrylic or polyester polymers are suitable. In addition, the amount of hydrophilic functional groups such as carboxyl groups and hydroxyl groups in the polymer is important.If the hydrophilic groups are too large, the electrodeposition layer will not be sufficiently insolubilized to form a non-uniform film, and if too small, the neutralization will occur. The water solubility of is insufficient.

The amount of the binder resin added is preferably 5 to 30 parts by weight with respect to 100 parts by weight of the liquid crystal, together with the amount of the monomer forming the capsule wall. If the amount of the liquid crystal used is too small, not only the transparency when the voltage is turned on is insufficient, but also a large amount of voltage is required to bring the film into a transparent state. If the amount used is too large, not only the scattering (turbidity) when the voltage is turned off becomes insufficient, but also the strength of the film decreases, which is not preferable.
Examples of the neutralizing agent include potassium hydroxide, sodium hydroxide and the like as the inorganic substance, and as the organic substance,
Examples thereof include triethylamine and diethylenetriamine. When the ion-dissociative group is a carboxyl group, the amount of the neutralizing agent added is 1 equivalent of the carboxyl group,
It is a ratio of 0.2 to 2 equivalents.

Further, as the auxiliaries which can be used, a surfactant or an organic solvent for imparting dispersion stability of the liquid crystal-containing microcapsules, a leveling agent and a defoaming agent for improving the smoothness of the coating film, etc. Is mentioned. As organic solvents,
Water is the main component, but isopropanol, n-butyl alcohol, t-butyl alcohol, methyl cellosolve,
Ethyl cellosolve, isopropyl cellosolve, butyl cellosolve, diethylene glycol methyl ether, etc. are used.

Specifically, the electrode substrate in which the compartment made of the heat-fusible adhesive layer is formed is immersed as a main electrode in an electrodeposition liquid containing liquid crystal-containing microcapsules. When the ion dissociative group of the binder resin in the electrodeposition liquid is anionic, the electrode substrate is connected to a power source so that it serves as an anode for electrodeposition coating. On the other hand, the counter electrode plate required for electrodeposition coating is immersed in the electrodeposition liquid containing the liquid crystal-containing microcapsules. In this state, when electricity is applied between both electrodes, the liquid crystal-containing microcapsules are electrophoresed on the anode, which is the electrode substrate, while being incorporated in the binder resin, and deposited and formed on the electrode surface of the electrode substrate.

Next, another embodiment of the method of manufacturing the liquid crystal / polymer composite film type display device of the present invention will be described with reference to the process diagram of FIG. In the first step, as shown in FIG. 3A, a pattern of the heat-fusible adhesive layer 5 is provided on the transparent conductive film 3 on one substrate 2 by, for example, a screen printing method. Next, in the second step, as shown in FIG. 3b, a peelable film 8 having openings of a desired pattern is formed on the heat-fusible adhesive layer to form a peeling layer. The release layer can also be formed by screen printing of a release resin.

In the third step, as shown in FIG. 3c, after the liquid crystal emulsion 6 from which air bubbles have been sufficiently removed is gently poured into a compartment made of a heat-fusible adhesive layer, a soft metal or A squeegee 7 made of hard rubber or the like is used to flatten the surface of the liquid crystal emulsion. In the subsequent fourth step, the peelable film is peeled off after drying at room temperature or at a temperature that does not affect the liquid crystal emulsion.
Further, in the fifth step, the other conductive substrate having the transparent conductive film is brought into close contact with the liquid crystal / polymer composite film and heated at a temperature at which the heat-meltable adhesive melts and adheres to the structure shown in FIG. To obtain a liquid crystal / polymer composite film type display device. When a voltage is applied by an external charge such as corona charging, a substrate having no transparent conductive film may be used. on the other hand,
The filling of the liquid crystal emulsion into the compartment formed of the heat-fusible adhesive layer in the third step can also be performed by using the electrodeposition method, as in the above-mentioned embodiment.

[0041]

EXAMPLES Next, the present invention will be described more specifically with reference to examples. Example 1 Glass substrate with ITO (100 mm × 100 mm × 1.
A grid pattern of a heat-fusible acrylic adhesive HS-32 (manufactured by Showa Ink Mfg. Co., Ltd.) having a thickness of 8.5 μm was formed on the ITO surface (1 mm) by a screen printing method.
As the grid pattern, a pattern of 300 μm × 250 μm was used. The grid pattern of the resulting heat-fusible adhesive was set to 1
It was heat-cured at 20 ° C. for 30 minutes to form a heat-fusible adhesive layer having a thickness of 8 μm. Then, a PET film having a thickness of 10 μm was attached only to the grid pattern portion of the heat-fusible adhesive layer. The PET film is the thickness of the volume reduction of the liquid crystal emulsion when it is dried, and is 10 μm in this embodiment.
It was m. Next, a nematic liquid crystal (Merck, E-
44) in an aqueous solution of polyvinyl alcohol (KP-06, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) in a weight ratio of P after drying.
The liquid crystal emulsion was obtained by adjusting and dispersing so that VA / E-44 = 8/2. The liquid crystal was dispersed by a membrane emulsification system (made by Ise Chemical Industry Co., Ltd.) with an average pore diameter of 0.1.
Using 9 μm porous glass, the liquid crystal was pressed into a PVA aqueous solution. Then, the liquid crystal emulsion is placed in a compartment formed of a grid pattern of the heat-fusible adhesive layer,
After filling with a squeegee for screen printing, it was dried with a dryer and the PET film was peeled off. As a result, a liquid crystal / polymer composite film having the same thickness as the heat-fusible adhesive layer was formed. Above the liquid crystal / polymer composite film surrounded by the heat-fusible adhesive layer thus obtained, the I of the PET film with ITO (thickness 125 μm) forming the other conductive substrate was formed.
The target liquid crystal / polymer composite film type display device was obtained by bringing the TO faces into close contact with each other and sticking them together using a laminator heated to 80 ° C. The obtained liquid crystal / polymer composite film type display element was excellent in adhesiveness without bubbles or unevenness, and was white and opaque when no voltage was applied, but became colorless and transparent when a voltage was applied. . Example 2 Similar to Example 1, a glass substrate with ITO (100 mm
X 100 mm x 1.1 mm) ITO surface is screen-printed onto the ITO surface of the heat-sealable acrylic adhesive HS-32.
(Showa Ink Industry Co., Ltd.) grid pattern 8.5 μm
It was formed with a thickness of. Lattice pattern is 300μm × 25
A 0 μm pattern was used. The resulting grid pattern of the heat-fusible adhesive is cured by heating at 120 ° C. for 30 minutes,
A μm heat-fusible adhesive layer was formed. Next, an O / W type emulsion was prepared under the following conditions using an MPG film emulsification system manufactured by Ise Chemical Industry Co., Ltd. Oil phase: Nematic liquid crystal BL-010 (manufactured by Merck) 100.00 g Methyl methacrylate 3.00 g Azobisisobutyronitrile 0.08 g Aqueous phase: Polyvinyl alcohol KP-06 5 0.000 g (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) Water 95.00 g Porous glass ... ・ Made by Ise Chemical Industry Co., Ltd. MPG (pore size: 0.19 μm) Pipe pressure ... 1.85 to 1.95 kgf / cm2 Flow rate in tube ... 0.8 m / sec 2 at 70 ° C. without stirring the obtained emulsion.
By heating for 0 hour, microcapsules containing liquid crystal in polymethylmethacrylate were obtained. The average particle size of the obtained microcapsules was 1.7 μm. The microcapsules were isolated by repeating sedimentation by centrifugation and washing with water to prepare an electrodeposition liquid for electrodeposition coating having the following composition. The above microencapsulated liquid crystal 40.0 g Acrylic copolymer having an ion dissociative group 5.0 g Triethylamine 1.4 g Ethanol 30.0 g Water 200.0 g The acrylic copolymer having an ion dissociative group has the following composition. , Nitrogen gasification, reaction at 60 ° C. for 7 hours, synthesis, synthesis by purification by reprecipitation method, and isolation. Methacrylic acid 10.0 g Methyl methacrylate 11.0 g Butyl methacrylate 38.0 g 2-Ethoxyethanol 89.0 g Azobisisobutyronitrile 1.2 g The electrodeposition solution was put in an electrodeposition bath, and a stainless plate was used as a cathode.
As a positive electrode, the glass substrate on which the grid-like pattern composed of the heat-fusible adhesive layer obtained as described above was formed was dipped, and energized at 25 V for 40 seconds, and electrodeposited to the same film thickness as the grid-like pattern. did. Then, the glass substrate was pulled up from the electrodeposition bath, washed with water, and dried at 60 ° C. for 8 hours to form a liquid crystal / polymer composite film having a film thickness of 8 μm surrounded by the heat-fusible adhesive layer. A PET film with ITO (thickness 125 μm) which is the other conductive substrate is provided above the liquid crystal / polymer composite film surrounded by the heat-fusible adhesive layer thus obtained.
The ITO surface of was adhered to and adhered using a laminator heated to 80 ° C. to obtain a target liquid crystal / polymer composite film type display element. The obtained liquid crystal / polymer composite film type display element has no bubbles or unevenness and has excellent adhesiveness,
It was white and opaque when no voltage was applied, but became colorless and transparent when a voltage was applied. Example 3 Similar to Example 1, a glass substrate with ITO (100 mm
X 100 mm x 1.1 mm) ITO surface is screen-printed onto the ITO surface of the heat-sealable acrylic adhesive HS-32.
(Showa Ink Industry Co., Ltd.) grid pattern 8.5 μm
It was formed with a thickness of. Lattice pattern is 300μm × 25
A 0 μm pattern was used. The resulting grid pattern of the heat-fusible adhesive is cured by heating at 120 ° C. for 30 minutes,
A μm heat-fusible adhesive layer was formed. After that, a thickness of 10 is formed only on the grid pattern portion of the heat-fusible adhesive layer.
A μm PET film was attached. Then, a nematic liquid crystal (M-137, manufactured by Merck & Co., E-44) in which a dichroic dye (M-137, manufactured by Mitsui Toatsu Dye ┻) is dissolved in an aqueous solution of polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., KP-06). , PVA / E-44 / dichroic dye by weight ratio after drying =
It was adjusted to 8/2 / and dispersed to obtain a liquid crystal emulsion. The liquid crystal was dispersed by a membrane emulsification system (manufactured by Ise Chemical Co., Ltd.) using porous glass having an average pore diameter of 0.19 μm by press-fitting the liquid crystal and the dichroic dye into an aqueous PVA solution. Then, a metal mask was placed on the grid pattern of the heat-fusible adhesive layer, the liquid crystal emulsion was filled with a squeegee for screen printing, and then dried with a drier. Similarly, an emulsion in which a dichroic dye (M-421, manufactured by Mitsui Toatsu Dye ┻) is dissolved is similarly coated on the metal mask having another pattern,
Dried. Further, an emulsion in which a dichroic dye (SI-426, manufactured by Mitsui Toatsu Dye ┻) was dissolved was similarly coated on the metal mask having another pattern and dried. Then, the PET film was peeled off to form a liquid crystal / polymer composite film having the same thickness as the heat-fusible adhesive layer. Liquid crystal surrounded by the heat-fusible adhesive layer thus obtained /
ITO which is the other conductive substrate above the polymer composite film
The target liquid crystal / polymer composite film type display device was obtained by bringing the ITO surface of the attached PET film (thickness 125 μm) into close contact and sticking using a laminator heated to 80 ° C. The obtained liquid crystal / polymer composite film type display element has excellent adhesiveness without bubbles and unevenness, and in the opaque state colored red, blue and green for each pattern unless a voltage is applied. However, when a voltage was applied, it became colorless and transparent. Moreover, when voltage application / non-application was selected for each pattern, various color patterns could be displayed.

EFFECTS OF THE INVENTION By using a heat-melting adhesive which is solid at room temperature as a partition wall, it is possible to suppress the exudation of liquid crystal into the adhesive and the adverse effect of the adhesive on the liquid crystal / polymer composite film. . Further, by using the heat-meltable adhesive as the partition wall, the pattern formation of the liquid crystal / polymer composite film is facilitated, the liquid crystal dispersion is not wasted, stable coating is possible, there is no coating unevenness, and the liquid crystal is It is possible to prevent bubbles from being mixed in the liquid crystal / polymer composite film in the display element.
Furthermore, by adding a dichroic dye to the liquid crystal / polymer composite film and applying the dichroic dye by screen printing using a metal mask, it is possible to separately paint each pixel, so that arbitrary color display can be performed. Easy, conventional TN type or ST
It is possible to inexpensively supply a reflective color display panel that cannot be represented by the N type.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a liquid crystal / polymer composite film type display element of the present invention.

FIG. 2 is a diagram illustrating a method for manufacturing a liquid crystal / polymer composite film type display element of the present invention.

FIG. 3 is a diagram illustrating a method for manufacturing a liquid crystal / polymer composite film type display element of the present invention.

[Explanation of symbols]

 1: Liquid crystal / polymer composite film type display device 2: Substrate 3: Transparent conductive film 4: Liquid crystal / polymer composite film 5: Thermal adhesive adhesive layer 2: Liquid crystal emulsion 2: Squeegee 8: Release layer

Claims (10)

[Claims] 1. A device having an electrode on at least one substrate 2
Liquid crystal composed of a liquid crystal / polymer composite film sandwiched between two substrates /
In a polymer composite film type display device, a liquid crystal / polymer composite film is formed in a pattern, and two substrates are adhered to each other around the pattern formed liquid crystal / polymer composite film. Liquid crystal characterized by having an adhesive layer formed /
Polymer composite film type display device. 2. The liquid crystal / polymer composite film type display element according to claim 1, wherein the liquid crystal / polymer composite film is formed in a plurality of compartments partitioned by a heat-fusible adhesive layer. 3. The liquid crystal / polymer composite film type display device according to claim 2, wherein the liquid crystal / polymer composite film is colored with a dichroic dye. 4. The liquid crystal / polymer composite film type display device according to claim 3, wherein the liquid crystal / polymer composite film in adjacent regions is colored with a dichroic dye having a different hue for each pixel. 5. The liquid crystal / polymer composite film type display device according to claim 1, wherein at least one of the two substrates is made of a flexible film. 6. A device having electrodes on at least one substrate
Liquid crystal composed of a liquid crystal / polymer composite film sandwiched between two substrates /
In the method for manufacturing a polymer composite film type display element, a plurality of compartments partitioned by partition walls made of a heat-fusible adhesive is formed on one substrate, and the compartments are filled with a liquid crystal emulsion and dried. Then, a method of manufacturing a liquid crystal / polymer composite film type display device, characterized in that the opposing substrates are superposed and heated to bond the two substrates. 7. A device having electrodes on at least one substrate
Liquid crystal composed of a liquid crystal / polymer composite film sandwiched between two substrates /
In the method for producing a polymer composite film type display element, a plurality of compartments partitioned by partition walls made of a heat-fusible adhesive is formed on one substrate, and a release layer is formed on the partition walls.
A method for manufacturing a liquid crystal / polymer composite film type display device, which comprises filling a liquid crystal emulsion in a compartment, drying the liquid, and then stacking opposing substrates and heating them to bond the two substrates. 8. The method for producing a liquid crystal / polymer composite film type display device according to claim 6, wherein the liquid crystal emulsion is filled in the compartment made of the heat-fusible adhesive layer by an electrodeposition method. 9. The method for producing a liquid crystal / polymer composite film type display device according to claim 6, wherein the liquid crystal emulsions of a plurality of colors are separately applied to each compartment. 10. The liquid crystal / high-level liquid crystal according to claim 9, wherein the liquid crystal emulsion is separately coated by overlaying a metal mask aligned with the compartment on the partition wall and filling the compartment with the liquid crystal emulsion through an opening portion of the mask. Method for manufacturing molecular composite film type display device.