JP3226845B2 - Method for manufacturing polymer dispersed liquid crystal display element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for manufacturing a liquid crystal display element used for a liquid crystal television, a liquid crystal projector and the like.

[0002]

2. Description of the Related Art Liquid crystal display elements, which take advantage of the features of thinness, small size, low voltage drive, and low power consumption, display from watches, calculators, etc., to navigation systems, notebook computers, liquid crystal monitors, data projectors, projection liquid crystal televisions. It is widely used everywhere. Among such display modes of the liquid crystal display element, TN (Twisted) is more widely used than before.
Nematic) liquid crystal element having a structure in which liquid crystal molecules are twisted 90 degrees vertically between two opposing substrates.
It is sandwiched between two polarizing plates. Also, an STN (Super Tw) in which the time-division driving characteristics of the TN method are improved.
Liquid crystal display elements of the ised nematic type are also used in Japanese word processors and the like. further,
Recently, an information device using a ferroelectric liquid crystal, which changes the arrangement state of liquid crystal molecules by spontaneous polarization of the liquid crystal molecules and uses an electro-optic effect accompanying the change in the arrangement state for display, has been put to practical use.

However, since these liquid crystal display elements require at least one polarizing plate, there have been problems that the liquid crystal display is dark, that an alignment treatment is required, and that the cell thickness control is not easy.

On the other hand, for such a liquid crystal display device,
There has been proposed a method in which a polarizing plate is unnecessary, and the arrangement of liquid crystal molecules is controlled by an electric field to create a cloudy state or a transparent state. In this method, when a composite of liquid crystal and a transparent polymer is sandwiched between two substrates, and the liquid crystal molecules have a positive dielectric anisotropy, the ordinary refractive index of the liquid crystal molecules and the refractive index of the transparent polymer are used. If the indices match, a voltage is applied to align the long axes of the liquid crystal molecules in parallel with the electric field, and when they match the refractive index of the transparent polymer, there is no light scattering at the interface, so the state becomes transparent, On the other hand, when no voltage is applied, the liquid crystal molecules are oriented in various directions, and the refractive index does not match at the interface with the transparent polymer. is there.

A typical example of this method is NCAP (Ne
magic Curvilineear Aligned
Phase is a nematic liquid crystal microencapsulated with polyvinyl alcohol or the like (powder and industrial, VOL.22, NO.8 (199)
0)). In addition, PDLC (Polymer
Dispersed Liquid Crysta
1), which is a method of dispersing liquid crystal microdroplets in a polymer matrix (Flat Panel Display '91, Nikkei BP, p. 219). Also, PNL
C (Polymer Network Liquid)
Crystal), which has a structure in which the resin spreads in a three-dimensional network in the continuous phase of the liquid crystal (IEICE Technical Report, EID
89-89, p1). These composites of liquid crystal and transparent polymer are collectively called polymer dispersed liquid crystal.

Conventionally, these methods for producing a composite of a liquid crystal and a polymer involve a mixed composition obtained by dissolving a liquid crystal material and an uncured resin monomer such as an acrylic or epoxy ultraviolet curable resin between two substrates. When the resin is injected and irradiated with ultraviolet rays, the resin monomer is polymerized and the liquid crystal and the resin undergo phase separation. As a result, a structure in which a liquid crystal is dispersed in a polymer or a structure in which a polymer spreads in a network in a liquid crystal is obtained (flat panel display '91, Nikkei B
Company P, p219, IEICE Technical Report, EI
D89-89, p1 etc.).

In such a polymer-dispersed liquid crystal, in order to improve the light scattering property of the composite of the liquid crystal and the polymer, the shape of the liquid crystal droplet is flat (the cross-sectional shape of the liquid crystal droplet is perpendicular to the substrate). Japanese Unexamined Patent Publication No. Hei.
No. 80302 and JP-A-7-181454.

That is, JP-A-5-80302 discloses that
Irradiating the mixture of resin monomer and liquid crystal material with ultraviolet light,
The polymer and the liquid crystal are phase-separated, and the liquid crystal droplet separated and deposited by heating and pressurizing means is subjected to a deformation ratio (in this publication, a ratio of the major axis to the minor axis of the cross section of the liquid crystal droplet). A technique for flattening to zero is disclosed. In addition, Japanese Patent Application Laid-Open
Japanese Patent No. 181454 discloses that a thickness of a separated and deposited liquid crystal droplet is reduced to １ ／ to （by a method of applying pressure while polymerizing by irradiating ultraviolet rays, or a method of applying pressure while heating and polymerizing. A technique of flattening up to a deformation ratio of 2 to 4) is disclosed.

[0009]

However, in the prior art described in Japanese Patent Application Laid-Open No. 5-80302, since the polymerization of the liquid crystal is not performed after the flattening step of the liquid crystal, the flattened liquid crystal display element is not used. In addition, the state in which the polymerization reaction of the resin monomer immediately before the flattening is performed is not completely completed is maintained, and the resin is not completely cured. Therefore, even if the liquid crystal droplet is once flattened, there is a problem that the flattening effect is alleviated with the passage of time and the state before flattening gradually returns.

In this regard, in the prior art described in Japanese Patent Application Laid-Open No. Hei 7-181454, since a polymerization process is performed on the mixture after the flattening step of the liquid crystal, the liquid crystal droplets become uncured as time elapses. The problem of gradually returning to the state has been resolved. However, in this prior art, 2
The following new problems arise because all of the polymerization steps in the step are based on photopolymerization by ultraviolet rays or all are based on thermal polymerization by heating.

That is, in the case where the two polymerization steps are photopolymerization using ultraviolet light, the polymerization reaction of the resin monomer progresses in the polymerization step before the flattening step, for example, in consideration of the flattening step of the liquid crystal. Even if it is desired to be in a state of 80% completion, it is difficult to realize that state, and there is a possibility that variations occur in each liquid crystal cell.
The reason is that the progress of the polymerization reaction is affected by the irradiation time of the ultraviolet rays, and furthermore, there is a characteristic that the polymerization reaction proceeds in an extremely short time. Therefore, the deformation ratio of the liquid crystal after the flattening step varies due to the variation in the degree of progress of the polymerization reaction.

In particular, in this prior art, the deformation ratio is 2 to 4
, The degree of progress of the polymerization reaction greatly affects the flattening. Therefore, there is a problem that the variation in the deformation ratio due to the variation in the degree of progress of the polymerization reaction exceeds the allowable range, and the reliability of the liquid crystal display element is deteriorated. On the other hand, if the reliability of the liquid crystal display element is to be improved, the production margin must be reduced, and the operation becomes troublesome, which causes a problem that the production cost is increased. In addition, when both of the two-stage polymerization steps are thermal polymerization, the progress of the polymerization reaction is slow, so that the degree of progress of the polymerization reaction does not vary as much as in the case of the photopolymerization, but the deformation ratio is still extremely large. In consideration of the above, the same problem as in the case of the photopolymerization may occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a highly reliable polymer-dispersed liquid crystal display having a flattening effect of a liquid crystal which can be stably maintained for a long time, has excellent light scattering properties, has a high contrast, and has high contrast. An object of the present invention is to provide a device manufacturing method and a device.

[0014]

According to the first aspect of the present invention, the first polymerization step is a thermal polymerization, the second polymerization step is a photopolymerization, and the mixture contains a thermal polymerization initiator. The amount is the amount in which the polymerizable material is brought into a predetermined first polymerization state when all the thermal polymerization initiator is consumed by the thermal polymerization reaction, and the content of the photopolymerization initiator is at least by the photopolymerization reaction. When the photopolymerization initiator is completely consumed, the amount is such that the polymerization can be performed from the first polymerization state to the second polymerization state in which the polymerization reaction of all the polymerizable materials is completely completed. I do.

According to the above configuration, the thermal polymerization initiator reacts in the first polymerization step, all the thermal polymerization initiator is consumed, and the first polymerization state is attained. In this state, for example, a majority or more of the polymerizable materials polymerize, and the mesh size of the composite of the liquid crystal and the polymer is substantially determined. Next, the liquid crystal becomes flat in the thickness direction by pressing. In the subsequent second polymerization step, the polymerizable material remaining by the reaction of the photopolymerization initiator present in the composite is completely polymerized to cause crosslinking. Thereby, the flat shape of the liquid crystal can be fixed and stabilized. In the present invention, since the first polymerization step is thermal polymerization and the second polymerization step is photopolymerization, a desired first polymerization state can be obtained by adjusting the content of the thermal polymerization initiator. Becomes possible. Therefore, the first
Both the second polymerization step and the second polymerization step can eliminate the problems that occur in the prior art in which photopolymerization is performed.

The invention according to claim 2 is characterized in that the first polymerization step is photopolymerization, the second polymerization step is thermal polymerization, and the content of the photopolymerization initiator in the mixture is determined by photopolymerization. When the initiator was completely consumed, the amount of the polymerizable material was changed to the predetermined first polymerization state, and the content of the thermal polymerization initiator was at least consumed by the thermal polymerization reaction. Sometimes, the amount is such that the polymerization can be performed from the first polymerization state to the second polymerization state in which the polymerization reaction of all the polymerizable materials is completely completed.

According to the above configuration, the photopolymerization initiator reacts in the first polymerization step, and all the photopolymerization initiator is consumed and
In the polymerization state. In this state, for example, a majority or more of the polymerizable materials polymerize, and the mesh size of the composite of the liquid crystal and the polymer is substantially determined. Next, the liquid crystal becomes flat in the thickness direction by pressing. In the subsequent second polymerization step, the polymerizable material remaining by the reaction of the thermal polymerization initiator present in the composite is completely polymerized to cause crosslinking. Thereby, the flat shape of the liquid crystal can be fixed and stabilized. In the present invention, since the first polymerization step is photopolymerization and the second polymerization step is thermal polymerization, a desired first polymerization state can be obtained by adjusting the content of the photopolymerization initiator. Becomes possible. Therefore, it is possible to solve the problem that occurs in the prior art in which both the first and second polymerization steps are photopolymerization.

According to a third aspect of the present invention, one of the substrates has a substrate surface on which metal wiring is formed in a striped or matrix form, and the liquid crystal cell into which the mixture has been injected is irradiated with ultraviolet rays from one of the substrates. And the polymer and liquid crystal are phase-separated by photopolymerization.After the extrusion step, the mixture is irradiated with ultraviolet rays from the other substrate side to polymerize the unreacted polymerizable material remaining by photopolymerization. It is characterized by making it.

According to the above configuration, ultraviolet rays are shielded at the portions where the stripe-shaped or matrix-shaped metal wiring is formed. Therefore, when ultraviolet light is irradiated from one of the substrates, the ultraviolet light passes only through the opening (the part other than the metal wiring part), and the mixture present in that part determines the mesh size of the composite of the liquid crystal and the polymer by a polymerization reaction. Is done. However, polymerization of the mixture located at the lower part of the metal wiring portion has progressed only partially due to leaked light, and is almost unreacted. When this substrate is pressed and deformed in the thickness direction, the liquid crystal in the opening can be easily pushed out from the sealing portion along the stripe-shaped or matrix-shaped metal wiring portion,
The flat shape of the liquid crystal can be extremely easily formed. When ultraviolet light is irradiated from the other substrate side, the mixture existing in the metal wiring portion is polymerized, and this portion serves as an adhesive for the entire substrate, fixing the flat shape of the liquid crystal,
Can be stabilized.

According to a fourth aspect of the present invention, in the third aspect, a pixel electrode and an active element are formed in each of a plurality of regions defined by matrix wiring on the substrate surface. It is an active substrate.

According to the above configuration, the same operation and effect as the third aspect of the invention can be obtained.

According to a fifth aspect of the present invention, in the fourth aspect, the active element is a TFT.

According to the above configuration, the same operation and effect as those of the fourth aspect can be obtained.

According to a sixth aspect of the present invention, in the first to fifth aspects of the present invention, the glass transition temperature of the polymer in the first polymerization state is defined as Tg1, and the polymer in the second polymerization state is defined as Tg1. When Tg2 is the glass transition temperature of Tg2, Tg2 is higher than Tg1 by 10 ° C. or more.

According to the above configuration, since the resin before the extrusion step has a low glass transition temperature, it can be easily softened and flattened easily. In addition, since the glass transition temperature of the resin after the second polymerization step is high, the resin is hardened, and the effect of returning to the state before flattening can be suppressed.

Further, in the invention according to claim 7, the first and second polymerization steps are photopolymerization, the glass transition temperature of the polymer in the first polymerization state is Tg1, and the high temperature in the second polymerization state is Tg1. Assuming that the glass transition temperature of the molecule is Tg2, Tg2 is higher than Tg1 by 10 ° C. or more.

According to the above configuration, the flattening can be easily caused and the effect of returning to the state before the flattening can be suppressed, similarly to the sixth aspect of the present invention.

According to an eighth aspect of the present invention, in the first to seventh aspects, the step of extruding the liquid crystal is heating.

Since the step of extruding the liquid crystal is heating, the thermal expansion coefficient of the liquid crystal material is much larger than that of the polymer or the cell substrate without using a pressing device. By returning to a working temperature range of 60 ° C. or lower after sealing with the sealing resin, flattening can be performed, and the flat shape can be fixed and stabilized.

According to a ninth aspect of the present invention, in the first to seventh aspects, the step of extruding the liquid crystal is pressing by a press.

Since the step of extruding the liquid crystal is pressing by a press, the liquid crystal can be pressed uniformly.

According to a tenth aspect of the present invention, in the first to seventh aspects, the step of extruding the liquid crystal is a pressing by a roller.

Since the step of extruding the liquid crystal is performed by pressing with a roller, uniform and continuous pressing can be performed, so that the productivity is good. Further, if the liquid crystal is pressed toward the sealing portion with a roller, the liquid crystal can be easily formed. Can be extruded.

According to an eleventh aspect of the present invention, in the first to seventh aspects, the step of extruding the liquid crystal is a pressing with a vacuum pack.

By pressing with a vacuum pack,
No special equipment is required, and the pressing can be performed very uniformly.

According to a twelfth aspect of the present invention, the first and second polymerization steps are photopolymerization, and the liquid crystal droplets separated and precipitated in the first polymerization step are deformed in the cell thickness direction.
Cooling the liquid crystal cell, after the cooling step, irradiating ultraviolet rays while maintaining the cooling state as a second polymerization step, and polymerizing the remaining unreacted polymerizable material by photopolymerization. .

According to the above configuration, the photopolymerization initiator reacts in the first polymerization step, for example, a majority or more of the polymerizable material is polymerized, and the mesh size of the composite of the liquid crystal material and the polymer is substantially determined. You. Next, by cooling, the liquid crystal becomes flat in the thickness direction by pressing based on thermal stress due to a large thermal expansion coefficient of the liquid crystal material. Then, by irradiating ultraviolet rays in the second polymerization step in this state, the polymerizable material remaining by the reaction of the photopolymerization initiator present in the composite is completely polymerized, and the flat shape is fixed and stabilized. Can be.

The invention according to claim 13 is characterized in that the first polymerization step is thermal polymerization, the second polymerization step is photopolymerization,
The liquid crystal cell is cooled in order to deform the liquid crystal droplets separated and precipitated in the polymerization step in the cell thickness direction. After the cooling step, the mixture is irradiated with ultraviolet rays while maintaining the cooling state as a second polymerization step, The remaining unreacted polymerizable material is polymerized by polymerization.

With the above configuration, the thermal polymerization initiator reacts in the first polymerization step, and all the thermal polymerization initiator is consumed and
In the polymerization state. In this state, for example, a majority or more of the polymerizable materials polymerize, and the mesh size of the composite of the liquid crystal and the polymer is substantially determined. Next, by cooling, the liquid crystal material has a flat shape in the thickness direction due to pressing based on thermal stress due to a large thermal expansion coefficient of the liquid crystal material. Then, by irradiating ultraviolet rays in the second polymerization step in this state, the polymerizable material remaining by the reaction of the photopolymerization initiator present in the composite is completely polymerized,
The flat shape can be fixed and stabilized. In the present invention, since the first polymerization step is a thermal polymerization and the second polymerization step is a photopolymerization, by adjusting the content of the thermal polymerization initiator, the same effect as the above-mentioned claim 1 can be obtained. In addition, it is possible to eliminate the problems that occur in the prior art in which both the first and second polymerization steps are photopolymerization.

[0040]

[0041]

[0042]

[0043]

According to a fourteenth aspect of the present invention, the liquid crystal cell into which the mixture has been injected is conveyed along a conveyance path, and during this conveyance, a part of the liquid crystal cell is irradiated with ultraviolet rays. An ultraviolet irradiation area of the liquid crystal cell is pressed by the roller during a period until phase separation of the liquid crystal by polymerization is completed.

With the above configuration, the first polymerization step and the liquid
Automation of the crystal extrusion process is achieved. In addition, the first and
UV irradiation time when both photopolymerization and second polymerization step
Even after controlling the polymerization reaction by UV irradiation,
Since the polymerization reaction proceeds for a certain period of time,
In the control only by the interval, the liquid crystal separated and deposited is flattened.
Work may be difficult. In this respect, in the present invention,
Optimal rotation speed of roller and transfer speed of liquid crystal cell
At the start of polymerization by UV irradiation
From the time when the polymerization is completed
Press the liquid crystal cell in the optimal polymerization state
It becomes possible. As a result, flattening of the liquid crystal is facilitated.
Come. Also, suppose that the polymerization process using ultraviolet rays
One time only, do not perform polymerization after the liquid crystal extrusion process.
The rotation speed of the roller and the
By adjusting the transfer speed of
The flattening of the liquid crystal and the mitigation of the flattening effect after flattening.
The optimally polymerized liquid crystal cell is pressed by rollers.
The flattening effect after flattening.
A relatively stable liquid crystal display device can be manufactured.

According to a fifteenth aspect of the present invention, in any one of the first to fourteenth aspects, the deformation ratio of the liquid crystal droplet is changed to be 1.15 or less. And

In the above configuration, the reason why the deformation ratio is set to 1.15 or less is that if the deformation ratio is too large, the light scattering property is rather deteriorated. In addition, by making the deformation ratio extremely small as compared with the prior art, the light scattering property can be improved, and the first and second polymerization steps are both photopolymerized. In such a case, the following specific effects occur. That is, as described in the section of the prior art, when the first and second polymerization steps are both photopolymerization, the variation in the deformation ratio is caused by the variation in the degree of progress of the polymerization reaction in the first polymerization step. Occurs. However, in the present invention in which the deformation ratio is extremely small as compared with the conventional technology, even if the degree of progress of the polymerization reaction varies,
Since the influence on the deformation ratio is extremely small, it is possible to solve the problem that the reliability of the liquid crystal display element of the related art is inferior.

[0048]

[0049]

[0050]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 is a sectional view of a polymer-dispersed liquid crystal display device manufactured by the manufacturing method according to the present invention, and FIG. 2 is a plan view thereof. In the liquid crystal display device shown in FIG. 1, two glass substrates 1,
Transparent electrodes 3 and 4 are formed inside 2, respectively, and a polymer / liquid crystal composite 7 in which liquid crystal droplets 6 are dispersed in a polymer 5 is disposed between the transparent electrodes 3 and 4.

As shown in FIG. 1, the liquid crystal droplet 6 has a flat structure whose length is reduced in the cell thickness direction. By thus deforming the liquid crystal droplet 6 in a flat shape, the liquid crystal molecules in the liquid crystal droplet 6 are relatively aligned substantially parallel to the substrates 1 and 2. Therefore, the scattering property when no voltage is applied is improved.
In the present embodiment, the flat state of the liquid crystal droplet 6 is 1.15 or less in terms of the deformation ratio. Desirably, the range is 1.05 to 1.15. Here, the deformation ratio refers to a cell thickness ratio before and after deformation. In addition,
The reason why the deformation ratio is set to 1.15 or less is that when the deformation ratio is too large, the light scattering property is worse than when the deformation is not performed.

In FIG. 1, the arrangement of the liquid crystal molecules is depicted as a bipole structure having two poles in the horizontal direction of the drawing, but this is intended that the bipole axis exists substantially parallel to the substrate. It is not intended that the bipole axes be aligned in one axial direction. As shown in FIG. 2, the bipole axis exists at random in the substrate surface.

The polymer-dispersed liquid crystal according to the present invention is not limited to a polymer-liquid crystal composite having a structure in which liquid crystal droplets are scattered in a polymer in an island shape. It may exist in a state of being connected to an adjacent liquid crystal droplet. Also, 3
A structure in which liquid crystal droplets are held in a polymer network having a three-dimensional network (polymer network liquid crystal) may be used.

The above liquid crystal display element comprises (1) preparation of an empty cell, (2) preparation of a mixture, (3) step of injecting the mixture between substrates, (4) first polymerization step, and (5) liquid crystal. And (6) a second polymerization step. Hereinafter, each step will be described specifically.

(1) Preparation of Empty Cell A pair of transparent glass substrates 1 and 2 provided with transparent electrodes 3 and 4 are provided with a sealing portion for injecting liquid crystal with a thermosetting sealing material 8 via a spacer. The sealing material 8 is completely cured by bonding and heating to produce an empty cell.

(2) Preparation of Mixture A liquid crystal material, a thermal polymerization initiator, a photopolymerization initiator, and a polymerizable material are added, and the mixture is stirred to prepare a uniform mixed solution. Here, as the liquid crystal material, a nematic liquid crystal having a positive dielectric anisotropy and exhibiting a liquid crystal state at around normal temperature,
Various liquid crystal materials such as cholesteric liquid crystal and smectic liquid crystal can be used. Specific examples of the liquid crystal material include TL
-213 (manufactured by Merck). In addition, one kind of these liquid crystal materials may be used, or two or more kinds may be used in combination. In addition, for example, 2
The present invention may be applied to a liquid crystal display device capable of full-color display, in which a dichroic dye of a different color is contained and a polymer / liquid crystal composite layer is laminated. May be applied.

As the thermal polymerization initiator, for example, t-
Butyl peroxide can be used. Further, as the photopolymerization initiator, for example, Darocure 1173 (manufactured by Ciba-Geigy Corporation) can be used.

As the polymerizable material, various polymerizable substances that can be polymerized by light or heat to produce a polymer compound having transparency can be used. In general, for example, polymerizable substances such as acrylate, methacrylate, epoxy and the like can be used. Monomers or oligomers having a functional group are used. Specifically, as the polymerizable monomer, for example, n-tridecyl acrylate, 2-ethylhexyl acrylate,
Hydroxyethyl acrylate, monohydroxyethyl phthalate phthalate, neopentyl glycol diacrylate, hexanediol diacrylate and the like can be used. As the polymerizable oligomer, polyurethane acrylate, 1,6 hexanediol diacrylate, pentaerythritol diacrylate monostearate,
Oligourethane acrylate, polyester acrylate, glycerin diglycidyl ether and the like can be used.

The contents of the thermal polymerization initiator and the photopolymerization initiator in the mixture are determined in consideration of the first polymerization step and the second polymerization step. That is, when the first polymerization step is thermal polymerization, the content of the thermal polymerization initiator is changed to the first polymerization state by the fact that the thermal polymerization initiator is completely consumed in the polymerization reaction with the polymerizable material. It is the amount that can be. Here, the first polymerization state means that the polymer and the liquid crystal undergo phase separation, the polymerization reaction of the polymerizable material is in progress, and the unreacted polymerizable material remains in the polymer. Further, the cured state of the polymer means that the polymer is in a predetermined cured state in which a part of the liquid crystal in the separated and deposited liquid crystal droplet can be pushed out from between the substrates to the outside.

When the second polymerization step is photopolymerization, the content of the photopolymerization initiator is determined by at least a polymerization reaction with the remaining polymerizable material in which the photopolymerization initiator is unreacted. The amount is such that the second polymerization state can be attained. Here, the second polymerization state refers to a state in which the remaining unreacted polymerizable material is photopolymerized, all polymerization reactions of the polymerizable material are completely completed, and the polymer is completely cured. means.

In the case where the first polymerization step is photopolymerization and the second polymerization step is thermal polymerization, the first polymerization step is the same as the case where the first polymerization step is thermal polymerization and the second polymerization step is photopolymerization. Based on this idea, the contents of the thermal polymerization initiator and the photopolymerization initiator in the mixture are determined.

(3) Step of Injecting Mixture Between Substrates The above-mentioned solution-like mixture is injected from the sealing portion of the empty cell.

(4) First Polymerization Step The mixture in the liquid crystal cell is heated. Thereby, the polymerizable material (polymerizable monomer and polymerizable oligomer) reacts with the thermal polymerization initiator, and the polymer and the liquid crystal undergo phase separation. The phase separated liquid crystal is dispersed in the polymer / liquid crystal composite 7 as spherical liquid crystal droplets having a diameter of about several μm. In the first polymerization step, as shown in FIG. 3, a first polymerization state before the polymerization reaction of all the polymerizable materials is completely completed (for example, a state in which about 80% of the whole is polymerized). so,
finish. Therefore, in the first polymerization state, for example, about 20% of the unreacted polymerizable material remains.

(5) Step of Extruding Liquid Crystal In order to deform the spherical liquid crystal droplet into a flat shape, the liquid crystal cell is pressed and the liquid crystal is extruded from the sealing portion of the liquid crystal cell to the outside. Here, as described above, in the first polymerization step, the liquid crystal can be easily extruded since the polymerization reaction of the polymerizable material is in a state before the polymerization reaction is completely completed. In this way, by pushing the liquid crystal to the outside, the liquid crystal droplet 6
Has a flat structure shrunk in the cell thickness direction.
The ratio of liquid crystal molecules in which the liquid crystal molecules are substantially parallel to the substrate increases, and the scattering intensity can be increased. As means for pressing the liquid crystal, for example, pressing by a press, pressing by a roller, pressing by a vacuum pack, and the like are used.
The step of extruding the liquid crystal may be performed during the first polymerization step.

(6) Second Polymerization Step After the step of extruding the liquid crystal, the mixture is irradiated with ultraviolet rays to photopolymerize the remaining unreacted polymerizable material, and as shown in FIG. Completely terminate the polymerization reaction of all the polymerizable materials. Thereby, since the polymer is in a completely cured state, the flat structure of the liquid crystal droplet can maintain the state even after a long period of time, thereby improving the reliability of the liquid crystal display element. be able to. Note that the second polymerization step may be performed during the liquid crystal extrusion step. As described above, according to the present invention, a highly reliable liquid crystal display device having excellent light scattering properties can be manufactured.

(Embodiment 2) In Embodiment 1 described above, although the first polymerization step was thermal polymerization and the second polymerization step was photopolymerization, as shown in FIG. The polymerization step may be photopolymerization, and the second polymerization step may be thermal polymerization.

(Embodiment 3) In this embodiment, the liquid crystal display element is an active matrix type liquid crystal display element using a TFT (thin film transistor) substrate, and both the first polymerization step and the second polymerization step are photopolymerized. It is what it was.

First, in the first polymerization step, a TFT having matrix-shaped metal wirings (scanning lines, signal lines, etc.) is formed.
Ultraviolet rays are irradiated from the substrate side. As a result, no polymerization reaction occurs in a region shielded from light by the metal wiring. Therefore, in the step of extruding the liquid crystal, the region serves as a passage for extruding the liquid crystal to the outside, so that the process of extruding the liquid crystal becomes easy. In the second polymerization step after the liquid crystal extrusion step, ultraviolet light is irradiated from the other substrate side. As a result, the unreacted region is polymerized, and this region serves as an adhesive for the entire substrate, fixing the flat shape of the liquid crystal droplet,
Can be stabilized.

As described above, in the case of the active matrix type liquid crystal display device, a unique effect is obtained in that the liquid crystal is easily extruded. Further, this unique effect can solve the problem that the manufacturing operation of the liquid crystal display element which occurs when both the first and second polymerization steps described in the above-mentioned prior art are photopolymerization is difficult. it can. This is because, for example, even when the irradiation time of the ultraviolet ray becomes slightly longer than the set time and the polymerization reaction proceeds from the predetermined first polymerization state and the hardness of the polymer becomes equal to or higher than the set hardness, the matrix-shaped wiring portion is not formed. This is because the unreacted portion serves as a passage for extruding, and does not hinder the extrusion process of the liquid crystal. Therefore, the manufacturing margin can be widened, and the manufacturing operation becomes easy. In this embodiment, a TFT is used as an active element, but a TFD (thin film diode) may be used. Further, the present invention is not limited to an active matrix type liquid crystal display element, and a liquid crystal having a structure in which one of a pair of substrates has a light-shielding region formed by stripe-shaped or matrix-shaped wiring on the substrate surface. The present invention can be suitably applied to the manufacture of a display element and the like.

(Embodiment 4) Further, the degree of curing of the resin in the first and second polymerization steps may be determined from the glass transition temperature, and the resin may be manufactured so as to satisfy the conditions relating to such a glass transition temperature. . That is, assuming that the glass transition temperature of the resin after the first polymerization step is T1 and the glass transition temperature of the resin after the second polymerization step is T2, T2 is 10 ° C. or more higher than T1. A liquid crystal display element may be manufactured.

(Embodiment 5) When the second polymerization step is photopolymerization, a step of cooling the liquid crystal cell may be used instead of the step of extruding the liquid crystal. Even by using such a cooling step, the separated and precipitated liquid crystal droplets can be deformed in the cell thickness direction. However, in the second polymerization step, it is necessary to irradiate ultraviolet rays while maintaining the liquid crystal cell in a cooled state. This is because if the cooling state is not maintained, the deformation of the liquid crystal may return to the original state during the irradiation time of the ultraviolet rays, which causes the reliability of the liquid crystal display element to deteriorate. In addition to the case where the step of cooling the liquid crystal cell is used instead of the step of extruding the liquid crystal, the step of extruding the liquid crystal and the step of cooling may be used in combination.

(Embodiment 6) In this embodiment, the first polymerization step and the liquid crystal extrusion step can be performed automatically and continuously by using a liquid crystal display element manufacturing apparatus. It was done. The apparatus for manufacturing a liquid crystal display element includes a conveying unit that conveys the liquid crystal cell along a conveying path, an ultraviolet irradiation unit that irradiates a part of the liquid crystal cell with ultraviolet light during the conveyance, and the ultraviolet light of the liquid crystal cell is irradiated. It consists of a roller that presses the area. As the transport means,
For example, a belt mechanism or a chain mechanism is used, and as the ultraviolet irradiation means, for example, a high-pressure mercury lamp is used. In addition, UV irradiation means other than high-pressure mercury lamp,
A configuration including an optical filter that blocks only a wavelength component that photolyzes a liquid crystal out of ultraviolet light from a high-pressure mercury lamp may be used. Further, a temperature control mechanism for maintaining the liquid crystal cell at a predetermined temperature may be provided in addition to the transport means, the ultraviolet irradiation means, and the rollers.

Next, a method for manufacturing a liquid crystal display element using the above-described manufacturing apparatus will be described. First, the liquid crystal cell into which the mixture has been injected is transported along the transport path. During the transportation, a part of the liquid crystal cell is irradiated with ultraviolet light, and the roller is pressed with the ultraviolet irradiation area of the liquid crystal cell by a roller during a period from the start of the polymerization by the irradiation of the ultraviolet to the completion of the phase separation of the liquid crystal by the polymerization. I do. Thus, the first polymerization step and the liquid crystal extrusion step can be performed automatically and continuously.

In the case where the second polymerization step is photopolymerization using ultraviolet rays, an ultraviolet irradiation means may be further provided downstream of the rollers on the conveying path. This makes it possible to automate a series of steps including the first polymerization step, the liquid crystal extrusion step, and the second polymerization step.

Further, as another embodiment, both the first and second polymerization steps may be heat polymerization.
In addition, even if both the first and second polymerization steps are thermal polymerization, in the present invention in which the deformation ratio is 1.15 or less, since the deformation ratio is extremely small as compared with the conventional technology,
It is possible to solve the problem that the manufacturing operation of the liquid crystal display element of the related art is difficult.

[0076]

EXAMPLES The method for producing a polymer-dispersed liquid crystal display device according to the present invention will be described in detail below with reference to examples.

(Example 1) A liquid crystal display element was produced by performing the first polymerization step by thermal polymerization and the second polymerization step by photopolymerization. This will be specifically described below with reference to FIG. A pair of transparent glass substrates 11 and 12 provided with transparent electrodes 13 and 14 made of an indium / tin oxide film are thermoset via a plastic spacer having a diameter of 12 μm (trade name: Micropearl: manufactured by Sekisui Fine Co., Ltd.). The sealing material 18 (trade name: Struct Bond: manufactured by Mitsui Toatsu Chemicals Co., Ltd.) is provided with a sealing portion 19 (see FIG. 6), bonded together, and heated at 150 ° C. for 2 hours to completely cure the sealing material 18. I got an empty cell.

Next, 8.50 g of TL-213 (manufactured by Merck) as a liquid crystal material, 0.80 g of n-tridecyl acrylate as a polymerizable monomer, 0.60 g of polyurethane acrylate as a polymerizable oligomer, and a thermal polymerization initiator T-butyl peroxide as a photopolymerization initiator, Darocure 1173 (Ciba-Geigy Corporation)
Was added, and the resulting mixture was sufficiently stirred at 25 ° C. to prepare a uniform mixed solution 10.

This homogeneous mixed solution 10 was vacuum-injected into the empty cell at 25 ° C. from the sealing portion 19 to obtain the state shown in FIG. Note that the sealing portion 19 is not sealed. Next, the liquid crystal cell into which the mixture has been injected is heated as shown in FIG. Specifically, the liquid crystal cell is set to 100
The sample was left for 1 hour in a thermostat set at ° C. As a result, the liquid crystal and the polymer were phase-separated by the thermal polymerization, and a polymer / liquid crystal composite 15 was obtained. At this point, unreacted polymerizable material remains in the composite 15. This was confirmed by examining the nematic phase-isotropic phase transition temperature of the liquid crystal cell. At this time, the composite 15 in the liquid crystal cell is
Had a structure in which a liquid crystal continuous phase was filled in a three-dimensional network polymer.

Next, as shown in FIG.
The liquid crystal cell was pressed at room temperature by a device for filling the balloon 23 with compressed air 24 of 1 kg / cm 2 via the air holes 1 and 22, and the liquid crystal was extruded from the sealing portion 19. After standing for about 10 minutes, the liquid crystal extruded into the sealing portion 19 was wiped off and sealed with an ultraviolet-curable sealing resin 25 (for example, Loctite LPD-155 (Nippon Loctite Co., Ltd.)).

Next, as shown in FIG.
UV cut filter U that cuts wavelength components below m
Light intensity 10 after passing through V-35 (manufactured by Toshiba Glass Co., Ltd.)
The liquid crystal cell was irradiated with ultraviolet rays from a high-pressure mercury lamp of 0 mW / cm 2 at 25 ° C. for 60 seconds. Thus, the remaining polymerizable material was polymerized by a reaction with the photopolymerization initiator. At this time, the ultraviolet curing sealing resin 25 is also cured at the same time.

The light scattering property of the polymer dispersion type liquid crystal display device thus completed was evaluated by light transmittance. Here, the light scattering property can be evaluated by the light transmittance.
This is because when the light scattering property is large, the transmittance is small, and when the light scattering property is small, the transmittance is large, and there is a correlation between the transmittance and the light scattering property.

Specifically, the transmittance was measured using an optical property evaluation device LCD-5000 manufactured by Otsuka Electronics Co., Ltd. under the conditions of a measurement temperature of 30 ° C., a light receiving angle of 2.8 °, and no electric field. As shown in Table 1, it was 0.8%.

[Table 1]

Next, the average mesh size (average gap between liquid crystal droplets parallel to the substrate surface) of the polymer dispersion type liquid crystal display device thus completed was examined with a microscope.
It was 1.2 μm. Further, a rectangular wave of 10 V, 30 Hz was applied to the transparent electrodes 13 and 14 of the polymer dispersion type liquid crystal display element, and the cell thickness was measured in a state where the liquid crystal molecules were completely aligned in parallel with the electric field. As shown in 1,
It was 10.9 μm. Next, the polymer dispersion type liquid crystal display device was left at 60 ° C. for 1000 hours, and then the transmittance and the cell thickness were measured in the same manner as described above. As shown in Table 1, no change was observed. .

The composite before extrusion and the composite irradiated with ultraviolet rays after extrusion were cut out of the panel, taken out of the panel, and the liquid crystal was rinsed with isopropyl alcohol to leave only the polymer. Then, the composite was analyzed with a differential scanning calorimeter (DSC). The endothermic peak was measured, and the glass transition temperature Tg (temperature of the endothermic peak) of the polymer was measured. The Tg1 of the polymer of the composite before extrusion was about 20 ° C., and the Tg2 of the polymer of the composite irradiated with ultraviolet light after extrusion was 30 ° C. Therefore, the condition that Tg2 was higher than Tg1 by 10 ° C. or more was satisfied.

(Example 2) A liquid crystal display element was produced by photopolymerization in the first polymerization step and thermal polymerization in the second polymerization step. This will be specifically described below. A mixture prepared in the same manner as in Example 1 was added to an empty cell prepared in the same manner as in Example 1 for 25 minutes.
Vacuum was injected into the empty cell at ℃. Then, without closing,
The liquid crystal cell was placed on a hot plate at 25 ° C., and the light intensity passed through an ultraviolet cut filter UV-35 was 50 mW.
UV light from a high-pressure mercury lamp of / cm 2 was irradiated for 20 seconds.
As a result, the polymerizable material was polymerized, and the liquid crystal and the polymer were phase-separated to obtain a composite. At this time, the UV irradiation intensity and the irradiation time were set slightly lower than in Example 2 in order to allow the unreacted polymerizable material to exist. At this time, the composite had a structure in which a continuous phase of liquid crystal was filled in a three-dimensional network-like polymer, as in Example 1. Next, in the same manner as in Example 1, the liquid crystal cell was pressed by a press device, and the liquid crystal was extruded from the sealing portion. Thereafter, the liquid crystal extruded into the sealing portion was wiped off, sealed with an ultraviolet-curing sealing resin as in Example 1, and the sealing resin was cured with a spot UV irradiator.

Next, the liquid crystal cell was allowed to stand in a thermostat set at 100 ° C. for 1 hour, and was subjected to thermal polymerization to completely polymerize the remaining polymerizable material in the composite.

The transmittance, mesh size and cell thickness of the polymer dispersion type liquid crystal display device thus completed were measured in the same manner as in Example 1, and were 0.8% and 1.2%, respectively.
μm and 10.9 μm.

Next, this polymer-dispersed liquid crystal display device was
After standing at 0 ° C. for 1000 hours, the transmittance and the cell thickness were measured in the same manner as above, but no change was observed.

Example 3 A liquid crystal display device was manufactured by photopolymerization in the first polymerization step and thermal polymerization in the second polymerization step. This will be specifically described below. In the same manner as in Example 2, preparation of an empty cell, preparation of a mixture, vacuum injection, and photopolymerization were performed to obtain a composite. Heating was performed as the next liquid crystal extrusion step. That is, the liquid crystal cell having the composite was placed in a thermostat and left at 120 ° C. for 10 hours. As a result, extrusion of the liquid crystal and thermal polymerization were simultaneously performed. Thereafter, the liquid crystal extruded into the sealing portion was wiped off, sealed with an ultraviolet-curing sealing resin, and cooled to 25 ° C.

The transmittance, mesh size and cell thickness of the polymer dispersion type liquid crystal display device thus completed were measured in the same manner as in Example 1. As a result, they were 1.1% and 1.2%, respectively.
μm and 11.6 μm.

Next, this polymer-dispersed liquid crystal display element was
After standing at 0 ° C. for 1000 hours, the transmittance and the cell thickness were measured in the same manner as above, but no change was observed.

(Example 4) A liquid crystal display element was produced by performing thermal polymerization in the first polymerization step and photopolymerization in the second polymerization step. This will be specifically described below. In the same manner as in Example 1, preparation of an empty cell, preparation of a mixture, vacuum injection, and thermal polymerization were performed to obtain a composite. As the next liquid crystal extruding step, pressing with a roller was performed. Specifically, the liquid crystal cell having the composite was kept at a temperature of 100 ° C., and was allowed to pass between the rollers from the end face opposite to the sealing part. The linear velocity of the liquid crystal cell was about 5 mm / sec. Thereafter, the liquid crystal extruded into the sealing portion was wiped off, sealed with an ultraviolet-curable sealing resin, cooled to 25 ° C., and polymerized with ultraviolet rays in the same manner as in Example 1.

The transmittance, mesh size and cell thickness of the polymer dispersion type liquid crystal display device thus completed were measured in the same manner as in Example 1 to be 1.0% and 1.2%, respectively.
μm and 11.4 μm. Next, after leaving this polymer-dispersed liquid crystal display element at 60 ° C. for 1000 hours,
The transmittance and cell thickness were measured in the same manner as above, but no change was observed.

(Example 5) A liquid crystal display device was manufactured by performing thermal polymerization in the first polymerization step and photopolymerization in the second polymerization step. This will be specifically described below. In the same manner as in Example 1, preparation of an empty cell, preparation of a mixed composition, vacuum injection, and thermal polymerization were performed to obtain a composite. As the next liquid crystal extruding step, pressing with a vacuum pack was performed. Specifically, while keeping the liquid crystal cell having the composite at 100 ° C.,
It was quickly vacuum-packed and left in a 100 ° C. thermostat again. After standing for about 2 hours, the vacuum pack was broken, the liquid crystal extruded into the sealing portion was wiped off, sealed with an ultraviolet-curable sealing resin, cooled to 25 ° C., and polymerized with ultraviolet rays as in Example 1.

The transmittance, mesh size and cell thickness of the polymer dispersion type liquid crystal display device thus completed were measured in the same manner as in Example 1, and were 0.9% and 1.2%, respectively.
μm and 11.2 μm. Next, after leaving this polymer-dispersed liquid crystal display element at 60 ° C. for 1000 hours,
The transmittance and cell thickness were measured in the same manner as above, but no change was observed.

(Embodiment 6) Embodiment 6 is an example in which the present invention is applied to the active matrix type liquid crystal display device shown in FIGS. 7 and FIG.
0 is a TFT array substrate. This TFT array substrate 3
0, a pixel electrode 32 and a TFT section 3 are provided in each of a plurality of regions defined by matrix wirings 31 on the substrate surface.
3 and a light shielding layer 34 are formed. In FIG. 7, the pixel electrode 32 and the TFT
The part 33 and the light shielding layer 34 are omitted. Further, since the light-shielding layer 34 and the liquid crystal display element of this embodiment are used for a projection type display device, they are provided for preventing deterioration of TFT characteristics due to light. 7 and 8, reference numeral 35 denotes a counter substrate. On the counter substrate 35, a counter electrode 36 is formed. A liquid crystal display device having such a configuration was manufactured by the following method.

A thermosetting sealing material (for example, Stract Bond: Mitsui Toatsu Chemicals) is applied to the substrates 30 and 35 via a plastic spacer (for example, Micropearl: Sekisui Fine Co., Ltd.) having a diameter of 11 μm. (Made by Corporation)
And sealing was performed by heating at 150 ° C. for 2 hours to completely cure the sealing material to obtain empty cells.

Next, TL-213 was used as a liquid crystal material.
50 g, 0.80 g of n-tridecyl acrylate as a polymerizable monomer, 0.60 g of polyurethane acrylate as an oligomer, and 0.10 g of Darocure 1173 as a photopolymerization initiator, and a mixture of a completed liquid crystal material and a polymerizable material was added. At 25 ° C. to prepare a uniform mixed solution. This homogeneous mixed solution was vacuum-injected into the empty cell at 25 ° C. from the sealing portion. At this stage, the sealing portion has not been sealed yet.

Next, a light intensity of 50 mW / c passed through the ultraviolet cut filter UV-35 from the array substrate 30 side.
Ultraviolet rays from a m2 high-pressure mercury lamp were irradiated at 25 ° C. for 20 seconds to polymerize and obtain a composite. In this state, the polymerization reaction hardly progresses in the light-shielding portion 60 located below the light-shielding region occupied by the wiring 31 and the light-shielding layer 34, and the unreacted polymerizable material remains. Further, in the composite 61 in the opening (the portion other than the light-shielding portion), the polymerization reaction of the polymerizable material is not completely completed, and about 20% of the unreacted polymerizable material remains, for example.

Next, the liquid crystal cell was pressed at room temperature by a pressing device as shown in FIG. 5C of Example 1, and the liquid crystal was extruded from the sealing portion. After standing for about 10 minutes, the liquid crystal extruded into the sealing portion was wiped off and sealed with an ultraviolet-curable sealing resin 40 (for example, Loctite LPD-155). Next, the liquid crystal cell was placed on the opposite substrate 35 side.
Light intensity 1 passed through UV cut filter UV-35
UV light from a high-pressure mercury lamp of 00 mW / cm2
For 60 seconds, and the remaining polymerizable material was polymerized by reaction with a photopolymerization initiator.

The transmittance of the polymer-dispersed liquid crystal display device thus completed was evaluated by using an optical characteristic evaluation device LCD manufactured by Otsuka Electronics Co., Ltd.
Measured according to -5000. Specifically, the measurement temperature 30
The measurement was performed under the conditions of ° C., a light receiving angle of 2.8 °, and no electric field. The result was 0.8% after correcting the aperture ratio (60% in this example). Next, the average mesh size of the openings of the polymer dispersion type liquid crystal display device thus completed with respect to the composite 61 was 1.2 μm. Also, the mesh size of the complex 60 in the light-shielding portion is
It was larger than 1.2 μm.

Next, after this TFT type polymer dispersed liquid crystal display element was left at 60 ° C. for 1000 hours, the transmittance was measured in the same manner as above, but no change was observed. In addition,
As shown in FIG. 9, the present invention can be suitably implemented in a liquid crystal display element in which a light shielding layer 34 is formed on a counter substrate 35.

Example 7 A liquid crystal display device was produced by photopolymerization in both the first and second polymerization steps. This will be specifically described below. The mixture prepared in the same manner as in Example 6 was vacuum-injected at 25 ° C. into the empty cell prepared in the same manner as in Example 1. Then, without sealing, the liquid crystal cell is
The sample was placed on a hot plate at a temperature of 200 ° C. and irradiated with ultraviolet rays from a high-pressure mercury lamp of 50 mW / cm 2 passed through an ultraviolet cut filter UV-35 for 20 seconds. As a result, the polymerizable material was photopolymerized, the liquid crystal and the polymer were phase-separated, and a composite was obtained.

Next, the liquid crystal cell was left in a constant temperature bath at 80 ° C. for 2 hours, and then the liquid crystal extruded into the sealing portion was wiped off.
Sealing was performed with an ultraviolet-curing sealing resin in the same manner as in Example 1, and the sealing resin was cured with a spot UV irradiator. Next, the liquid crystal cell was left in a constant temperature bath at −20 ° C. for 30 minutes, and then passed through an ultraviolet cut filter UV-35 at 100 mW /
Ultraviolet light from a high-pressure mercury lamp of 2 cm2 was irradiated at -20C for 120 seconds, and the remaining polymerizable material was polymerized by reaction with a photopolymerization initiator.

The transmittance, mesh size, and cell thickness of the polymer dispersion type liquid crystal display device thus completed were measured in the same manner as in Example 1, and were 1.1% and 1.2%, respectively.
μm and 11.6 μm. Next, after leaving this polymer-dispersed liquid crystal display element at 60 ° C. for 1000 hours,
The transmittance and the cell thickness were measured in the same manner as above, but there was no change.

Example 8 In this example, the first polymerization step using ultraviolet light and the liquid crystal extrusion step were performed continuously and automatically using the manufacturing apparatus shown in FIGS. 10 and 11. The manufacturing apparatus includes a conveying unit (not shown) for conveying the liquid crystal cell along the table 40, an ultraviolet irradiation unit 41 for irradiating a part of the liquid crystal cell with ultraviolet light, and a pair of pressing units for pressing an ultraviolet irradiation area of the liquid crystal cell. Rollers 42 and 43. The ultraviolet irradiation means 41 has a high-pressure mercury lamp 44 as a light source, a light shielding plate 46 having a rectangular slit 45 formed thereon, and an optical filter 48. The optical filter 48 is, for example, an ultraviolet cut filter UV-
35. The table 40 is configured to control the temperature. Thereby, the temperature of the liquid crystal cell placed on the table 40 can be adjusted to control the temperature-sensitive phase separation reaction. Further, the feeding speed of the liquid crystal cell by the transport means is such that when the polymer is in a predetermined cured state (first polymerization state) within a period from the start of polymerization by ultraviolet rays to the completion of polymerization, the liquid crystal cell It is set so as to reach the rollers 42 and 43.

A liquid crystal display device was manufactured as follows using the manufacturing apparatus having the above-described structure. The mixture prepared in the same manner as in Example 6 was mixed with the empty cell prepared in the same manner as in Example 1 for 2 hours.
Vacuum was injected into the empty cell at 5 ° C. Thereafter, the liquid crystal cell into which the mixture was injected was placed on the table 40, and was conveyed to the conveyance means. In addition, the temperature of the table 40 was set to 25 ° C. Under this temperature condition, a light intensity of 100 mW is applied to the liquid crystal cell.
While irradiating an ultraviolet ray of / cm 2 to polymerize the polymerizable material, the portion (ultraviolet irradiation area) was pressed by a roller. In addition, the liquid crystal cell is inserted from the side opposite to the sealing part,
Liquid crystal extruding has been made easier. In this manner, the first polymerization step using ultraviolet light and the liquid crystal extrusion step
Made continuously and automatically.

Next, the liquid crystal material extruded into the sealing portion was wiped off, sealed with an ultraviolet-curing sealing resin as in Example 1, and the sealing resin was cured with a spot UV irradiator. Next, an ultraviolet cut filter UV-35 is provided in the liquid crystal cell.
Was irradiated with ultraviolet rays from a high-pressure mercury lamp having a light intensity of 100 mW / cm2 for 60 seconds, and the remaining polymerizable material was polymerized by reaction with a photopolymerization initiator.

The transmittance, mesh size and cell thickness of the polymer dispersion type liquid crystal display device thus completed were measured in the same manner as in Example 1, and were 0.8% and 1.2%, respectively.
μm and 10.9 μm. Next, after leaving this polymer-dispersed liquid crystal display element at 60 ° C. for 1000 hours,
The transmittance and the cell thickness were measured in the same manner as above, but there was no change.

Incidentally, as shown in FIG.
43, a heater 50 is provided.
In 1, the first polymerization step and the liquid crystal extrusion step using ultraviolet light may be performed continuously and automatically. In this case, by controlling the temperature of the hot air 52 and the heater 50 sent into the constant temperature bath 51,
The first polymerization step and the liquid crystal extrusion step can be performed continuously and automatically in a more uniform and optimal temperature atmosphere.

(Comparative Example 1) In an empty cell prepared in the same manner as in Example 1, 8.50 g of TL-213 as a liquid crystal material and 0.5 ml of n-tridecyl acrylate as a polymerizable monomer were added.
80 g, 0.60 g of polyurethane acrylate as an oligomer, and 0.10 g of Darocur 1173 as a photopolymerization initiator were added, and the resulting mixture of the liquid crystal material and the polymerizable material was sufficiently stirred at 25 ° C. to prepare a uniform mixed solution. .

The homogeneous mixed solution was vacuum-injected into the empty cell at 25 ° C., and then, without sealing, the liquid crystal cell was placed on a hot plate at 25 ° C.
Ultraviolet rays from a high-pressure mercury lamp having a light intensity of 100 mW / cm2 passed through -35 were irradiated for 60 seconds, and the liquid crystal and the polymer were phase-separated while polymerizing the polymerizable material to obtain a composite. At this point, the polymerization reaction of the complex was almost completely completed. At this time, the composite in the liquid crystal cell had a structure in which a continuous phase of liquid crystal was filled in a three-dimensional network-like polymer, as in Example 1. Next, the liquid crystal extruded into the sealing part is wiped off and sealed with Loctite, an ultraviolet-curing sealing resin, and the spot UV is applied to the part.
The sealing resin was cured by irradiating it with ultraviolet light for 30 seconds using an irradiator.

The transmittance, mesh size and cell thickness of the polymer dispersion type liquid crystal display device thus completed were measured in the same manner as in Example 1. As shown in Table 1,
They were 1.4%, 1.2 μm and 12.0 μm, respectively. Next, this polymer-dispersed liquid crystal display element was heated at 60 ° C. for 1 hour.
After standing for 000 hours, the transmittance and the cell thickness were measured in the same manner as above, but no change was observed as shown in Table 1 above.

[Results] From Example 1 and Comparative Example 1, it can be seen that the deformation ratio of the liquid crystal cell of Example 1 was 1.1.
Further, as compared with Comparative Example 1 in which the deformation ratio was 1, that is, in which the flattening of the liquid crystal droplet or the network was not performed, Example 1 in which the deformation ratio was 1.1 had a higher transmission ratio as shown in Table 1 above. The rate is small. Therefore, it is understood that the scattering property can be improved when the liquid crystal droplet is deformed, as compared with the case where the liquid crystal droplet is not deformed. Example 1 and Comparative Example 1
The cell thickness after 1000 hours of each completed liquid crystal display element did not change as shown in Table 1 above. Therefore, when the polymerization reaction of the polymerizable material was completely terminated, No change is observed.

(Comparative Example 2) A mixture prepared in the same manner as in Example 1 was vacuum-injected into the empty cell prepared in the same manner as in Example 1 at 25 ° C, and heated under the same conditions as in Example 1. To polymerize the polymerizable material. Thereafter, the liquid crystal cell was pressed by a pressing device under the same conditions as in Example 1 and allowed to stand, and then the sealing portion was sealed.

The transmittance, mesh size and cell thickness of the polymer dispersion type liquid crystal display device thus completed were measured in the same manner as in Example 1. As shown in Table 1,
They were 0.8%, 1.2 μm and 10.9 μm, respectively. Next, this polymer-dispersed liquid crystal display element was heated at 60 ° C. for 1 hour.
After standing for 000 hours, the transmittance was measured in the same manner as described above. As shown in Table 1, the transmittance was 1.0%, and the cell thickness was 11.4 μm, indicating a change.

[Results] From Example 1 and Comparative Example 2, the first
In the liquid crystal display element of Comparative Example 2 in which only the polymerization step (in this case, thermal polymerization) was performed and the second polymerization step was not performed,
As shown in the figure, the transmittance and the cell thickness changed with time. Therefore, it is understood that the deformation of the liquid crystal droplets returns to the original state after a long time only in the first polymerization step (thermal polymerization in this case). Therefore, the liquid crystal display element of Comparative Example 2 is inferior in reliability.

Comparative Example 3 A mixed solution similar to that of Comparative Example 1 was vacuum-injected into an empty cell prepared in the same manner as in Example 1 at 25 ° C., and then the liquid crystal cell was sealed without sealing. 25
C. on a hot plate, and irradiated with UV light from a high-pressure mercury lamp of 100 mW / cm2 passed through a UV-cut filter UV-35 for 60 seconds to cause a phase separation between a liquid crystal material and a polymer while polymerizing the polymerizable material. The complex was obtained.
At this point, the polymerization reaction of the complex was almost completely completed. At this time, the composite in the liquid crystal cell had a structure in which a continuous phase of liquid crystal was filled in a three-dimensional network-like polymer, as in Example 1.

Next, the liquid crystal cell was pressed by the same pressing device as in Example 1, and the liquid crystal material was extruded from the sealing portion. At this time, the temperature was set to 100 ° C., and the pressure was 2
kg / cm 2 and left for about 60 minutes. Thereafter, the liquid crystal extruded into the sealing portion was wiped off, sealed with Loctite, an ultraviolet-curing sealing resin, and the portion was irradiated with ultraviolet rays for 30 seconds using a spot UV irradiator to cure the sealing resin.

The transmittance, mesh size and cell thickness of the polymer dispersion type liquid crystal display device thus completed were measured in the same manner as in Example 1. As shown in Table 1,
They were 0.8%, 1.2 μm and 10.9 μm, respectively. Next, this polymer-dispersed liquid crystal display element was heated at 60 ° C. for 1 hour.
After standing for 000 hours, the transmittance was measured in the same manner as described above. As shown in Table 1, the transmittance was 0.9%, and the cell thickness was 11.2 μm, indicating a change.

[Results] From Example 1 and Comparative Examples 2 and 3, even when the polymerization step was performed by ultraviolet rays, if only the first polymerization step was performed, the deformation of the liquid crystal droplets was as shown in Table 1 above. It can be understood that although the degree of the return is slightly slower than that of the comparative example 2, the flat shape of the liquid crystal droplet cannot be maintained for a long time. Therefore, like the comparative example 2, the liquid crystal display device of the comparative example 3 is inferior in reliability.

(Comparative Example 4) The mixture prepared in the same manner as in Comparative Example 2 was vacuum-injected into the empty cell at 25 ° C. into the empty cell prepared in the same manner as in Example 1, and then the liquid crystal was sealed without sealing. The cell was left in a thermostat set at 100 ° C. for 1 hour, and the liquid crystal and the polymer were phase-separated while polymerizing the polymerizable material to obtain a composite. Next, in the same manner as in Example 1, the liquid crystal cell was pressed by a press device, and the liquid crystal material was extruded from the sealing portion. At this time, the pressure was 2 kg / cm 2, and the mixture was left for about 60 minutes.

Thereafter, the liquid crystal material extruded into the sealing portion was wiped off, sealed with an ultraviolet-curable sealing resin as in Example 1, and the sealing resin was cured with a spot UV irradiator. Next, an ultraviolet cut filter UV-35 is provided in the liquid crystal cell.
UV light from a high-pressure mercury lamp having a light intensity of 100 mW / cm 2 passed through at a temperature of 25 ° C. for 60 seconds, and the remaining polymerizable material was polymerized by reaction with a photopolymerization initiator.

The transmittance, mesh size and cell thickness of the polymer dispersion type liquid crystal display element thus completed were measured in the same manner as in Example 1. As shown in Table 1,
They were 1.5%, 1.2 μm and 10.0 μm, respectively. Next, this polymer-dispersed liquid crystal display element was heated at 60 ° C. for 1 hour.
After standing for 000 hours, the transmittance and the cell thickness were measured in the same manner as described above, but there was no change as shown in Table 1 above.

[Results] The results of comparison will be described together with Comparative Example 5 described later.

(Comparative Example 5) A mixture prepared in the same manner as in Comparative Example 4 was vacuum-injected into the empty cell at 25 ° C into an empty cell produced in the same manner as in Example 1, and then the liquid crystal was sealed without being sealed. The cell was left in a thermostat set at 100 ° C. for 1 hour, and the liquid crystal and the polymer were phase-separated while polymerizing the polymerizable material to obtain a composite. Next, in the same manner as in Example 1, the liquid crystal cell was pressed by a press device, and the liquid crystal was extruded from the sealing portion.
At this time, the pressure was 1 kg / cm 2, and the mixture was left for about 20 minutes. Then, the composite was obtained by irradiating with ultraviolet rays in the same manner as in Comparative Example 4.

The transmittance, mesh size and cell thickness of the polymer dispersion type liquid crystal display device thus completed were measured in the same manner as in Example 1. As shown in Table 1,
They were 1.0%, 1.2 μm and 10.4 μm, respectively. Next, this polymer-dispersed liquid crystal display element was heated at 60 ° C. for 1 hour.
After standing for 000 hours, the transmittance and the cell thickness were measured in the same manner as described above, but no change was observed as shown in Table 1 above.

[Results] As shown in Table 1 above, Comparative Example 4
In Comparative Example 5 as well as in Example 1, there was no change in transmittance and cell thickness even after a long time. This is presumably because the polymerization treatment was further performed after the liquid crystal was extruded, and the remaining unreacted polymerizable material was polymerized to completely terminate the polymerization reaction of the polymerizable material. On the other hand, Comparative Example 4
Has a deformation ratio of 1.2 since the cell thickness after deformation is 10.0 μm. In Comparative Example 5, the cell thickness after deformation was 10.
Since it is 4 μm, the deformation ratio is about 1.15. Also,
The transmittance was 1.5% for Comparative Example 4 and 1.0% for Comparative Example 5.
It is. Therefore, it is understood from Example 1 and Comparative Examples 4 and 5 that, if it is excessively deformed, the transmittance is rather increased (in other words, the light scattering property is reduced).

It is understood from Comparative Examples 1 and 4 and 5 that when the deformation ratio is 1.2 or more, the transmittance is rather increased (in other words, the light scattering property is reduced) than when the deformation is not performed. Is done.

Japanese Unexamined Patent Publication No. 5-80302 discloses that scattering is good when the deformation ratio is 1.2 to 5.0, and Japanese Unexamined Patent Publication No. Hei 7-181454 desirably has a deformation ratio of 2 to 4. However, in our experiments, the tendency of the scattering property to increase due to the deformation was not observed when the deformation ratio was 1.1 or more, and the scattering property was worse than when the deformation was not performed when the deformation ratio was 1.2 or more. This is because the tendency of the liquid crystal molecules to be arranged perpendicularly to the interface of the polymer is strengthened, and it can be said that the simulation approaches a situation when a voltage is applied to the liquid crystal cell. This was confirmed by measuring the cell capacity or the dielectric constant when no electric field was applied and when 20 V where liquid crystal molecules were arranged parallel to the electric field was applied.

Comparative Example 6 A polymer-dispersed liquid crystal display element was manufactured in the same manner as in Example 1 except that the light intensity and irradiation time of the ultraviolet rays after the extrusion step were different. That is, a polymer-dispersed liquid crystal display device was manufactured by changing the conditions of the light intensity and irradiation time of ultraviolet rays in the second polymerization step by photopolymerization from those of Example 1. In Comparative Example 6, the intensity of the ultraviolet light was 50 mW / cm 2 and the irradiation time was 30 minutes.
Seconds.

The transmittance, mesh size and cell thickness of the polymer dispersion type liquid crystal display device thus completed were measured in the same manner as in Example 1, and were 0.8% and 1.2%, respectively.
μm and 10.9 μm. Next, after leaving this polymer-dispersed liquid crystal display element at 60 ° C. for 1000 hours,
When the transmittance was measured in the same manner as described above, the transmittance was 0.9%, and the cell thickness was 11.2 μm, indicating a change.

Next, the composite before extrusion and the composite irradiated with ultraviolet rays after extrusion were cut out of the panel, and only the polymer was left in the same manner as in Example 1. Then, a differential scanning calorimeter ( The endothermic peak was measured by DSC, and the glass transition temperature Tg (endothermic peak temperature) of the polymer was measured. The Tg1 of the polymer of the composite before extrusion is about 20
° C, and Tg2 after extrusion was about 25 ° C. Therefore, Tg2 did not satisfy the condition of 10 ° C. higher than Tg1.

[Results] When the Example 1 and Comparative Example 6 were judged from the viewpoint of the glass transition temperature of the polymer, Tg2 was found to be Tg2.
The flattening effect cannot be maintained for a long time if the temperature is greater than 1 ° C., but the flat shape can be maintained for a long time without the deformation of the liquid crystal droplet returning to the original shape if Tg2 is approximately 10 ° C. larger than the Tg1. Is understood.

[0136]

As described above, according to the present invention, the unreacted polymerizable material is polymerized after the liquid crystal is extruded, so that the polymer can be completely cured. Therefore, a flattening effect can be stably maintained for a long time, and a highly reliable liquid crystal display device having excellent light scattering and high contrast can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a polymer-dispersed liquid crystal display device manufactured by a manufacturing method according to the present invention.

FIG. 2 is a plan view of a polymer-dispersed liquid crystal display device manufactured by a manufacturing method according to the present invention.

FIG. 3 is a diagram for explaining a polymerization method in Embodiment 1.

FIG. 4 is a diagram for explaining a polymerization method according to a second embodiment.

FIG. 5 is a view showing a manufacturing process of the first embodiment.

FIG. 6 is a perspective view of the vicinity of a sealing portion 19;

FIG. 7 is an exploded perspective view of an active matrix type liquid crystal display device according to Example 6.

FIG. 8 is a cross section of an active matrix liquid crystal display device according to Example 6.

FIG. 9 is a cross section of an active matrix type liquid crystal display device having another configuration.

FIG. 10 is a sectional view of a manufacturing apparatus used in an eighth embodiment.

FIG. 11 is a plan view of a manufacturing apparatus used in an eighth embodiment.

FIG. 12 is a sectional view of a manufacturing apparatus having another configuration.

[Explanation of symbols]

 1, 2, 11, 12 ... glass substrate 3, 4, 13, 14 ... transparent electrode 5 ... polymer 6 ... liquid crystal droplet 7, 15 ... polymer / liquid crystal composite 10 ... mixed solution 30 ... TFT array substrate 31 ... matrix Shaped wiring 32 ... Pixel electrode 33 ... TFT part 34 ... Light shielding layer 35 ... Counter substrate 36 ... Counter electrode 40 ... Table 41 ... Ultraviolet irradiation means 42, 43 ... Roller 44 ... High pressure mercury lamp 45 ... Slit 46 ... Light shielding plate 48 ... Optical filter 50: heater 51: constant temperature bath 52: hot air

──────────────────────────────────────────────────続 き Continuing on the front page (72) Masao Yamamoto, Inventor 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Kazuo Inoue 1006, Kadoma, Kadoma, Kadoma, Osaka Matsushita Electric Industrial (72) Inventor Hiroshi Kubota 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Seiji Nishiyama 1006, Odaka Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (56) JP-A-5-80302 (JP, A) JP-A-5-181118 (JP, A) JP-A-4-188105 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/1334 G02F 1/13 101

Claims (15)

(57) [Claims] A polymer / liquid crystal composite comprising a polymer and liquid crystal droplets dispersed therein is disposed between a pair of substrates.
A method for producing a polymer-dispersed liquid crystal display device in which the liquid crystal droplets are deformed into a flat structure in which the liquid crystal droplets are shrunk in a cell thickness direction, wherein a liquid crystal material, a thermal polymerization initiator, a photopolymerization initiator, heat and It is a solution-like mixture composed of a polymerizable material that undergoes a polymerization reaction by any of light, and the content of the thermal polymerization initiator is changed when the thermal polymerization reaction consumes all of the thermal polymerization initiator. The amount of the photopolymerizable initiator is set to a predetermined first polymerization state, and the content of the photopolymerization initiator is set at least when the photopolymerization initiator is completely consumed by the photopolymerization reaction.
A step of preparing such a solution-like mixture, which is an amount capable of polymerizing from the polymerization state to the second polymerization state in which the polymerization reaction of all the polymerizable materials is completely completed; and A step of injecting between the substrates, and by heating the mixture, the polymer and the liquid crystal are phase-separated by thermal polymerization of the polymerizable material, and the polymerization reaction of the polymerizable material is in progress, Unreacted polymerizable material remains inside, and the cured state of the polymer is a predetermined cured state in which a part of the liquid crystal in the separated liquid crystal droplets can be pushed out from between the substrates to the outside. A first polymerization step of polymerizing to a first polymerization state, and a step of extruding a part of the liquid crystal in the liquid crystal droplets from between the substrates to deform the separated and deposited liquid crystal droplets in the cell thickness direction, After the extrusion step, A second polymerization step of irradiating the mixture with ultraviolet light, polymerizing the remaining unreacted polymerizable material by photopolymerization, and polymerizing from a first polymerization state to a second polymerization state. A method for producing a polymer-dispersed liquid crystal display device, comprising: 2. A polymer / liquid crystal composite in which liquid crystal droplets are dispersed in a polymer is disposed between a pair of substrates.
A method for producing a polymer-dispersed liquid crystal display device in which the liquid crystal droplets are deformed into a flat structure in which the liquid crystal droplets are shrunk in a cell thickness direction, wherein a liquid crystal material, a thermal polymerization initiator, a photopolymerization initiator, heat and It is a solution-like mixture composed of a polymerizable material that undergoes a polymerization reaction by any of light, and the content of the photopolymerization initiator is increased when the photopolymerization reaction consumes all of the photopolymerization initiator. The amount of the thermal polymerization initiator is set to a predetermined first polymerization state, and the content of the thermal polymerization initiator is set at least when the thermal polymerization initiator has completely consumed the thermal polymerization initiator.
A step of preparing such a solution-like mixture, which is an amount capable of polymerizing from the polymerization state to the second polymerization state in which the polymerization reaction of all the polymerizable materials is completely completed; and A step of injecting between the substrates, and by irradiating the mixture with ultraviolet rays, a polymer and a liquid crystal are phase-separated by photopolymerization of the polymerizable material, and a polymerization reaction of the polymerizable material is in progress, Predetermined curing in which unreacted polymerizable material remains in the polymer and the cured state of the polymer separates and precipitates some of the liquid crystal in the liquid crystal droplets from between the substrates to the outside. A first polymerization step of polymerizing to a first polymerization state in a state, and a step of extruding a part of the liquid crystal in the liquid crystal droplets from between the substrates to deform the deposited liquid crystal in a cell thickness direction; After the extrusion process A second polymerization step of heating the mixture, polymerizing the remaining unreacted polymerizable material by thermal polymerization, and polymerizing from a first polymerization state to a second polymerization state. A method for producing a polymer-dispersed liquid crystal display device, comprising: 3. A method in which liquid crystal droplets are dispersed in a polymer between one substrate having metal wires formed in a striped or matrix shape on the substrate surface and the other substrate disposed opposite to this substrate. A polymer-liquid crystal composite comprising: a polymer-dispersed liquid crystal display device, wherein the liquid crystal droplet is deformed into a flat structure in which the liquid crystal droplets are shrunk in the cell thickness direction. A step of preparing in advance a solution-like mixture composed of a photopolymerization initiator and a photopolymerizable material, injecting the mixture between the substrates, and irradiating the mixture with ultraviolet light from one of the substrates to perform polymerization. The first polymerization state in which the polymer and the liquid crystal are phase-separated by the photopolymerization of the polymerizable material, and the polymerization reaction of the polymerizable material is in progress and the unreacted polymerizable material remains in the polymer. A first polymerization step of polymerizing to A step of extruding a part of the liquid crystal in the liquid crystal droplets from between the substrates to deform the separated liquid crystal droplets in the cell thickness direction, and irradiating the mixture with ultraviolet rays from the other substrate side after the extruding step. Then, the remaining unreacted polymerizable material is polymerized by photopolymerization to polymerize from the first polymerization state to a second polymerization state in which the polymerization reaction of all the polymerizable materials is completely completed. A method for producing a polymer-dispersed liquid crystal display device, comprising: 4. The substrate according to claim 3, wherein said one substrate is an active substrate in which a pixel electrode and an active element are formed in each of a plurality of regions defined by matrix wiring on a substrate surface. A method for producing a polymer-dispersed liquid crystal display element. 5. The method according to claim 4, wherein the active element is a TFT. 6. Assuming that the glass transition temperature of the polymer in the first polymerization state is Tg1 and the glass transition temperature of the polymer in the second polymerization state is Tg2, Tg2 is higher than Tg1 by 10 ° C. or more. The method for producing a polymer-dispersed liquid crystal display device according to claim 1, wherein 7. A polymer / liquid crystal composite obtained by dispersing liquid crystal droplets in a polymer is disposed between a pair of substrates.
A method for producing a polymer-dispersed liquid crystal display device in which the liquid crystal droplets are deformed into a flat structure in which the liquid crystal droplets are shrunk in a cell thickness direction, comprising: A step of injecting the mixture between the substrates, and irradiating the mixture with ultraviolet light to cause a phase separation between a polymer and a liquid crystal by photopolymerization of the polymerizable material, A first polymerization step of polymerizing to a first polymerization state in which unreacted polymerizable material remains in the polymer while the polymerization reaction is in progress; and separating and depositing liquid crystal droplets in the cell thickness direction. A step of extruding a part of the liquid crystal in the liquid crystal droplet from the space between the substrates to the outside, and, after the extruding step, irradiating the mixture with ultraviolet rays, and the unreacted polymerizable material remaining by photopolymerization. Is polymerized to form a first polymerized A second polymerization step of polymerizing from the state to a second polymerization state in which the polymerization reactions of all the polymerizable materials are completely completed, wherein the glass transition temperature of the polymer in the first polymerization state is Tg1. Assuming that the glass transition temperature of the polymer in the second polymerization state is Tg2, Tg2 is 10% lower than Tg1.
A method for producing a polymer-dispersed liquid crystal display element, wherein the temperature is higher by at least 100 ° C. 8. The method for producing a polymer dispersed liquid crystal display device according to claim 1, wherein the step of extruding the liquid crystal is heating. 9. The method for producing a polymer dispersed liquid crystal display device according to claim 1, wherein the step of extruding the liquid crystal is pressing by a press. 10. The method for manufacturing a polymer dispersed liquid crystal display device according to claim 1, wherein the step of extruding the liquid crystal is pressing with a roller. 11. The method for producing a polymer-dispersed liquid crystal display device according to claim 1, wherein the step of extruding the liquid crystal is pressing with a vacuum pack. 12. A polymer / liquid crystal composite in which liquid crystal droplets are dispersed in a polymer is disposed between a pair of substrates, and the liquid crystal droplets are deformed into a flat structure contracted in the cell thickness direction. A method for producing a polymer-dispersed liquid crystal display device, comprising preparing in advance a solution-like mixture composed of a liquid crystal material, a photopolymerization initiator, and a photopolymerizable material, and injecting the mixture between the substrates. And irradiating the mixture with ultraviolet light, and phase-separating the polymer and the liquid crystal by photopolymerization of the polymerizable material, and the polymerization reaction of the polymerizable material is in progress, and unreacted in the polymer. A first polymerization step of polymerizing to a first polymerization state in which the polymerizable material remains, a step of cooling the liquid crystal cell to deform the separated and deposited liquid crystal droplets in the cell thickness direction, Later, while maintaining the cooling state, UV The mixture is irradiated and the remaining unreacted polymerizable material is polymerized by photopolymerization to polymerize from the first polymerization state to the second polymerization state in which the polymerization reaction of all the polymerizable materials is completely completed. A method of producing a polymer-dispersed liquid crystal display device, comprising: 13. A polymer / liquid crystal composite in which liquid crystal droplets are dispersed in a polymer is disposed between a pair of substrates, and the liquid crystal droplets are deformed into a flat structure contracted in the cell thickness direction. Comprising a liquid crystal material, a thermal polymerization initiator, a photopolymerization initiator, and a polymerizable material that undergoes a polymerization reaction by both heat and light. A solution mixture, the content of the thermal polymerization initiator, the amount of the polymerizable material is a predetermined first polymerization state when the thermal polymerization initiator is completely consumed by the thermal polymerization reaction, When the content of the photopolymerization initiator is at least when all the photopolymerization initiator is consumed by the photopolymerization reaction, the first
A step of preparing such a solution-like mixture, which is in an amount capable of polymerizing from the polymerization state to the second polymerization state in which the polymerization reaction of all the polymerizable materials is completely completed; and A step of injecting between the substrates, and by heating the mixture, the polymer and the liquid crystal are phase-separated by thermal polymerization of the polymerizable material, and the polymerization reaction of the polymerizable material is in progress, Unreacted polymerizable material remains therein, and the polymer is cured until the first polymerization state in which the cured state of the polymer becomes a predetermined cured state in which liquid crystal droplets separated and precipitated can be deformed by cooling. A first polymerization step to be performed, a step of cooling the liquid crystal cell after the first polymerization step so as to deform the separated and deposited liquid crystal droplets in the cell thickness direction, and a cooling state is maintained after the cooling step. Mix ultraviolet light as it is A second polymerization step of irradiating the compound, polymerizing the remaining unreacted polymerizable material by photopolymerization, and polymerizing from the first polymerization state to the second polymerization state. A method for producing a polymer-dispersed liquid crystal display device, which is characterized by the following. 14. A high-density liquid crystal obtained by dispersing liquid crystal droplets in a polymer.
The liquid crystal / liquid crystal composite is disposed between a pair of substrates.
In addition, the liquid crystal droplets have a flat structure in which the
A method for producing a deformed polymer-dispersed liquid crystal display
hand, Transport means for transporting the liquid crystal cells along the transport path;
Of the crystal cell transport route Some of the liquid crystal cells provided inside are purple
Ultraviolet light irradiating means for irradiating outside line, and transport path of liquid crystal cell
Area of the liquid crystal cell provided with the ultraviolet rays.
Equipped with rollers to press the area, Mixed composition containing liquid crystal material, photopolymerization initiator and polymerizable material
Is transported by the transporting means.
Transport along the road, During the transport, the ultraviolet light is applied to a part of the liquid crystal cell.
Irradiation with ultraviolet light by irradiation means, From the start of polymerization by UV irradiation, the phase of liquid crystal by polymerization
During the period until the separation is completed, the liquid crystal cell
The ultraviolet irradiation area is pressed by the roller.
Method of manufacturing polymer dispersed liquid crystal display device characterized by the following:
Law. 15. The liquid crystal droplet has a deformation ratio of 1.15 or less.
Claims characterized by being deformed to be below
A polymer-dispersed liquid crystal according to any one of claims 1 to 14.
A method for manufacturing a display element.