JP2001272665A - Manufacturing method of liquid crystal display element - Google Patents

Abstract

(57) [Problem] To provide a polymer-dispersed liquid crystal display device having high scattering performance, high contrast, and excellent display quality even at high temperatures without sacrificing hysteresis performance. A method of manufacturing a liquid crystal display device includes a polymer / liquid crystal composite layer sandwiched between a pair of substrates and electrodes for applying a voltage to the composite layer. A mixture composition injecting step of injecting a mixture composition containing a liquid crystal material and a photopolymerizable monomer between the substrates 2 and 3, and a first ultraviolet irradiation step of irradiating the mixture composition with ultraviolet rays. And liquid crystal are separated into phases, and the liquid crystal droplets 10 are separated and deposited.
A first ultraviolet irradiation step of irradiating ultraviolet light at a first ultraviolet intensity such that the shape of the liquid crystal becomes substantially spherical, and in order to further polymerize unreacted polymerizable monomers remaining in the liquid crystal droplets,
A second ultraviolet light irradiation step of irradiating ultraviolet light with a second ultraviolet light intensity lower than the first ultraviolet light intensity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a scattering type liquid crystal display device using a polymer dispersed liquid crystal used for a projection type display or 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, a composite of a liquid crystal material and a transparent polymer is sandwiched between two substrates, and when the liquid crystal molecules have a positive dielectric anisotropy, the ordinary refractive index of the liquid crystal molecules and the transparent polymer If the refractive index is matched, a voltage is applied to align the long axes of the liquid crystal molecules parallel to the electric field. On the other hand, when no voltage is applied, the liquid crystal molecules are oriented in various directions, so that the refractive index does not match at the interface with the transparent polymer, so that light scattering occurs and a cloudy opaque state is used. It is.

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)).

[0006] In addition, PDLC (Polym
er Dispersed Liquid Cryst
al), which is a method of dispersing liquid crystal microdroplets in a polymer matrix (Flat Panel Display '91, Nikkei BP, p. 219).

Further, PNLC (Polymer Net)
There is also a structure called a "Work Liquid Crystal", which has a structure in which a resin spreads in a three-dimensional network in a continuous phase of a liquid crystal (IEICE technical report, EID89-89, p1).

[0008] These composites of a liquid crystal material and a transparent polymer are collectively called polymer dispersed liquid crystal.

Conventionally, these methods for producing a composite of a liquid crystal material and a polymer include a method in which an uncured resin monomer such as an acrylic or epoxy ultraviolet curable resin and a liquid crystal material are dissolved in a mixed composition between two substrates. When irradiated with ultraviolet light, the resin monomer is polymerized and the liquid crystal material and the resin undergo phase separation. As a result, a structure in which the liquid crystal material is dispersed in the polymer or a structure in which the polymer spreads in a network in the liquid crystal is obtained (flat panel display).
91, Nikkei BP, p219, IEICE Technical Report, EID89-89, p1 etc.).

[0010]

In the above-mentioned conventional method for producing a polymer-dispersed liquid crystal, the phase separation of the liquid crystal and the complete polymerization of the resin monomer are performed once and by one type of ultraviolet irradiation as described above. I have. With such an irradiation method, the optimum UV irradiation condition for the phase separation state of the liquid crystal and the optimum UV irradiation condition for complete polymerization of the resin monomer are different, so that the hysteresis performance and the contrast performance are satisfied at the same time. An excellent polymer dispersed liquid crystal display element cannot be obtained.

More specifically, for example, when a strong ultraviolet ray is irradiated, the hysteresis performance is improved.
Since phase separation occurs rapidly, a large amount of unreacted resin monomer tends to remain in the liquid crystal droplets, the apparent refractive index anisotropy of the liquid crystal decreases, and the contrast performance decreases. Conversely, when irradiated with ultraviolet light of low intensity, the hysteresis performance deteriorates, but the phase separation occurs slowly, so that the unreacted resin monomer hardly remains in the liquid crystal droplets, and the apparent refractive index anisotropy of the liquid crystal And contrast performance is improved.
As described above, there is a trade-off relationship between the hysteresis performance and the contrast performance with respect to the ultraviolet intensity.
Therefore, in the conventional example in which irradiation with one kind of ultraviolet light is performed at one time, there is a problem that a polymer-dispersed liquid crystal display element having excellent display quality and simultaneously satisfying the hysteresis performance and the contrast performance cannot be obtained.

It is an object of the present invention to provide a method of manufacturing a polymer-dispersed liquid crystal display element having excellent display quality and simultaneously satisfying low hysteresis and high contrast required for a liquid crystal display device. Aim.

[0013]

According to the present invention, there is provided a method of manufacturing a polymer-dispersed liquid crystal display device, comprising separating a liquid crystal phase for determining hysteresis performance and a polymerization of a residual resin monomer for determining contrast performance as steps. By independently and optimally irradiating with ultraviolet light, a polymer-dispersed liquid crystal display device having excellent display quality and simultaneously satisfying hysteresis performance and contrast performance can be obtained. The specific configuration of the present invention is as follows.

The invention according to claim 1 includes a pair of substrates, a liquid crystal layer sandwiched between the pair of substrates, and an electrode for applying a voltage to the liquid crystal layer, wherein the liquid crystal layer has a polymer phase and a liquid crystal phase. A method for manufacturing a liquid crystal display device comprising a polymer / liquid crystal composite layer comprising: a mixed composition injecting step of injecting a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates; A first ultraviolet irradiation step of irradiating the mixed composition with ultraviolet light, wherein the polymer and the liquid crystal are phase-separated by the photopolymerization of the photopolymerizable material, and the shape of the separated and precipitated liquid crystal droplet becomes substantially spherical. A first ultraviolet irradiation step of irradiating ultraviolet light under the first irradiation condition, and an ultraviolet irradiation under the second irradiation condition in order to further polymerize the unreacted polymerizable material remaining in the liquid crystal droplet. And a second ultraviolet irradiation step.

A first ultraviolet irradiation condition for performing a phase separation of a liquid crystal for determining a hysteresis performance by the manufacturing method,
The second UV irradiation condition for polymerizing the residual resin monomer that determines the contrast performance can be performed under the optimum UV irradiation condition, and the polymer dispersion type having low hysteresis, high contrast, and excellent display quality can be used. A liquid crystal display element can be obtained.

According to a second aspect of the present invention, there is provided a pair of substrates, a liquid crystal layer sandwiched between the pair of substrates, and an electrode for applying a voltage to the liquid crystal layer, wherein the liquid crystal layer has a polymer phase and a liquid crystal phase. A method for manufacturing a liquid crystal display device comprising a polymer / liquid crystal composite layer comprising: a mixed composition injecting step of injecting a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates; A first ultraviolet irradiation step of irradiating the mixed composition with ultraviolet light, wherein the polymer and the liquid crystal are phase-separated by the photopolymerization of the photopolymerizable material, and the shape of the separated and precipitated liquid crystal droplet becomes substantially spherical. A first ultraviolet irradiation step of irradiating ultraviolet rays with the first ultraviolet intensity, and a second ultraviolet irradiation step weaker than the first ultraviolet intensity so as to further polymerize the unreacted polymerizable material remaining in the liquid crystal droplet. 2nd ultraviolet ray which irradiates ultraviolet rays with ultraviolet ray intensity of 2 Characterized in that it comprises a morphism step.

According to the above-described manufacturing method, while maintaining the state where the hysteresis is reduced by the irradiation of the first ultraviolet light having a large intensity (the phase separation structure of the liquid crystal is fixed by the irradiation of the first ultraviolet light), A cell having a preferable scattering gain can be produced by the second low intensity ultraviolet irradiation for polymerizing the remaining polymerizable material.

According to a third aspect of the present invention, in the method of manufacturing a liquid crystal display element according to the second aspect, a ratio of the first ultraviolet light intensity to the second ultraviolet light intensity is 5 or more.

Thus, the unreacted polymerizable material in the liquid crystal droplet can be more favorably polymerized, and the contrast can be further improved.

According to a fourth aspect of the present invention, the liquid crystal device includes a pair of substrates, a liquid crystal layer sandwiched between the pair of substrates, and an electrode for applying a voltage to the liquid crystal layer. A method for manufacturing a liquid crystal display device comprising a polymer / liquid crystal composite layer comprising: a mixed composition injecting step of injecting a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates; A first ultraviolet irradiation step of irradiating the mixed composition with ultraviolet light, wherein the polymer and the liquid crystal are phase-separated by the photopolymerization of the photopolymerizable material, and the shape of the separated and precipitated liquid crystal droplet becomes substantially spherical. A first ultraviolet irradiation step of irradiating ultraviolet light having the first ultraviolet spectral characteristic, and further polymerizing the unreacted polymerizable material remaining in the liquid crystal droplets.
The second has a longer wavelength component than the first ultraviolet spectral characteristic.
A second ultraviolet irradiation step of irradiating ultraviolet light having the ultraviolet spectral characteristics described above.

The ultraviolet spectral characteristic for optimizing the hysteresis performance is different from the ultraviolet spectral characteristic for suppressing the decomposition of the liquid crystal material as much as possible and efficiently polymerizing the unreacted resin monomer. Therefore, according to the above-described method, it is possible to obtain a polymer-dispersed liquid crystal display device that can irradiate with the optimum ultraviolet spectral characteristics, has low hysteresis, has high contrast, and has excellent display quality.

According to a fifth aspect of the present invention, in the method for manufacturing a liquid crystal display element according to the fourth aspect, in the first ultraviolet irradiation step, a component having a predetermined first wavelength or less among wavelength components of the ultraviolet light is used. Through a first ultraviolet cut filter that cuts the light, and in the second ultraviolet irradiation step, through a second ultraviolet cut filter that cuts a component having a second wavelength or less that is larger than the first wavelength. Irradiation.

With the above structure, it is possible to easily and stably obtain an ultraviolet light source having an optimum spectral characteristic, to obtain a polymer-dispersed liquid crystal display device having low hysteresis, high contrast and excellent display quality. it can.

According to a sixth aspect of the present invention, in the method for manufacturing a liquid crystal display element according to the fifth aspect, the ultraviolet intensity in the second ultraviolet irradiation step is lower than the ultraviolet intensity in the first ultraviolet irradiation step. It is characterized by the following.

According to the above configuration, it is possible to obtain a polymer-dispersed liquid crystal display device having a lower hysteresis and a higher contrast.

The invention according to claim 7 includes a pair of substrates, a liquid crystal layer sandwiched between the pair of substrates, and an electrode for applying a voltage to the liquid crystal layer, wherein the liquid crystal layer has a polymer phase and a liquid crystal phase. A method for manufacturing a liquid crystal display device comprising a polymer / liquid crystal composite layer comprising: a mixed composition injecting step of injecting a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates; A first ultraviolet irradiation step of irradiating the mixed composition with ultraviolet light, wherein the polymer and the liquid crystal are phase-separated by the photopolymerization of the photopolymerizable material, and the shape of the separated and precipitated liquid crystal droplet becomes substantially spherical. A first ultraviolet irradiation step of irradiating ultraviolet light at the first substrate temperature, and lowering the first substrate temperature to further polymerize the unreacted polymerizable material remaining in the liquid crystal droplets. A second ultraviolet light source for irradiating ultraviolet light at a second substrate temperature; Characterized in that it comprises a step.

With the above configuration, the ultraviolet irradiation temperature for optimizing the hysteresis performance is different from the ultraviolet irradiation temperature for suppressing the decomposition of the liquid crystal material as much as possible and efficiently polymerizing the unreacted resin monomer. By controlling the substrate temperature at the time and the substrate temperature at the time of the second ultraviolet irradiation respectively optimally, the hysteresis is low and the contrast is high.
A polymer-dispersed liquid crystal display device having excellent display quality can be obtained.

According to an eighth aspect of the present invention, in the method for manufacturing a liquid crystal display element according to the seventh aspect, the second substrate temperature is equal to or higher than a nematic-isotropic transition point of the liquid crystal after the first ultraviolet irradiation step. It is characterized by being.

As a result, since the polymerization reaction is accelerated by heat and a stirring action is added, the unreacted resin monomer can be efficiently polymerized, and the polymer dispersion type having low hysteresis, high contrast, and excellent display quality. A liquid crystal display element can be obtained.

According to a ninth aspect of the present invention, the liquid crystal device includes a pair of substrates, a liquid crystal layer sandwiched between the pair of substrates, and an electrode for applying a voltage to the liquid crystal layer. A method for manufacturing a liquid crystal display device comprising a polymer / liquid crystal composite layer comprising: a mixed composition injecting step of injecting a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates; A first ultraviolet irradiation step of irradiating the mixed composition with ultraviolet light, wherein the polymer and the liquid crystal are phase-separated by the photopolymerization of the photopolymerizable material, and the shape of the separated and precipitated liquid crystal droplet becomes substantially spherical. A first ultraviolet irradiation step of irradiating ultraviolet rays with the first ultraviolet intensity as described above, a heating step of heating the substrate, and cooling of the substrate. In this cooled state, unreacted residues remaining in the liquid crystal droplets In order to further polymerize the polymerizable material of A second ultraviolet irradiation step of irradiating ultraviolet rays with weak second ultraviolet intensity than the intensity, characterized in that it comprises a.

According to the above configuration, since the liquid crystal material, the polymerization initiator and the unreacted resin monomer are sufficiently stirred by heat, the unreacted resin monomer can be efficiently polymerized, the hysteresis is low, and the contrast is low. high,
A polymer-dispersed liquid crystal display device having excellent display quality can be obtained.

According to a tenth aspect of the present invention, in the method of the ninth aspect, the heating temperature in the heating step is equal to or higher than a nematic-isotropic transition point of the liquid crystal.

By heating the liquid crystal above the nematic-isotropic transition point of the liquid crystal composition, the liquid crystal material, the polymerization initiator and the unreacted resin monomer are sufficiently stirred by heat. A polymer-dispersed liquid crystal display device which can efficiently polymerize the monomer, has low hysteresis, high contrast, and excellent display quality can be obtained.

[0034] According to an eleventh aspect of the present invention, a pair of substrates are provided.
A liquid crystal display device comprising a liquid crystal layer sandwiched between a pair of substrates, and an electrode for applying a voltage to the liquid crystal layer, wherein the liquid crystal layer comprises a polymer / liquid crystal composite layer containing a polymer phase and a liquid crystal phase. A manufacturing method, a mixed composition injecting step of injecting a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates,
A first ultraviolet irradiation step of irradiating the mixed composition with ultraviolet light, wherein the polymer and the liquid crystal are phase-separated by photopolymerization of the photopolymerizable material, and the shape of the separated and precipitated liquid crystal droplet is substantially spherical. A first ultraviolet irradiation step of irradiating ultraviolet light within a time required to reach a maximum point in a nematic-isotropic transition point-ultraviolet irradiation time characteristic curve of the liquid crystal; A second ultraviolet irradiation step of irradiating ultraviolet rays with a second ultraviolet intensity lower than the first ultraviolet intensity so as to further polymerize the polymerizable material of the reaction.

When the nematic-isotropic transition point-ultraviolet irradiation time characteristic curve of the liquid crystal is measured with respect to the ultraviolet irradiation process of the polymer-dispersed liquid crystal, a large amount of unreacted resin monomer is present in the system in the region where the ultraviolet irradiation time is short. The nematic-isotropic transition point of the liquid crystal increases with the irradiation time of the ultraviolet ray, but when the ultraviolet ray is further irradiated, the amount of the unreacted resin monomer decreases, and this time, the nematic-isotopic transition point reaches the maximum point of the nematic-isotropic transition point. The isotropic transition point decreases. The main cause of this decrease is the decomposition of the liquid crystal material by ultraviolet rays. When the decomposition is increased and ions increase in the liquid crystal, the characteristics are deteriorated, or the TFT (thin film transistor) is deteriorated.
In the case of active matrix driving using, the voltage holding ratio is reduced and display quality is impaired. In order to solve such a problem, a polymer-dispersed liquid crystal display element having high contrast performance and excellent display quality by suppressing the decomposition of liquid crystal as much as possible and having a small amount of unreacted resin monomer by adopting the above configuration is provided. Can be.

[0036]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the polymer / liquid crystal composite layer is basically a polymer dispersed liquid crystal having a structure in which a liquid crystal phase is dispersed as an independent phase (liquid crystal droplet) in a polymer matrix (polymer phase). Although it is a (PDLC) layer, the liquid crystal phase and the polymer phase may form a continuous phase depending on the liquid crystal material and the polymerization conditions, as in the Technical Report of the Institute of Electronics and Communication Engineers (EID89-89, p1).

In the following description, a type in which a liquid crystal phase is dispersed in a polymer matrix as an independent phase will be mainly described. However, the present invention is not limited to this, and the liquid crystal phase and the polymer phase are continuous phases. Can also be applied to the polymer network structure forming

Embodiment 1 [Structure of Liquid Crystal Display Element] FIG. 1 is a sectional view showing one pixel of a liquid crystal display element according to Embodiment 1 of the present invention. The liquid crystal display element 1 includes a lower substrate 2, an upper substrate 3 disposed opposite to the lower substrate 2, and a polymer / liquid crystal composite layer 4 disposed between the lower substrate 2 and the upper substrate 3. Having. The lower substrate 2
The upper substrate 3 is a transparent substrate made of, for example, glass. On the inner surface of the lower substrate 2, a thin film transistor (TFT) as a pixel switching element, metal wiring (scanning signal line / image signal line) and a transparent pixel electrode 5 are formed. The metal wiring, the TFT, the pixel electrode 5 made of indium tin oxide (ITO), and the like are covered with an insulating film 6. It should be noted that, in FIG.
Etc. are omitted. A counter electrode 7 made of indium tin oxide (ITO) is formed on the inner surface of the upper substrate 3, and the counter electrode 7 is covered with an insulating film 8.

The polymer / liquid crystal composite layer 4 has a structure in which liquid crystal droplets 10 are dispersed in a polymer matrix 9. Here, it should be noted that the liquid crystal droplet 9 has a substantially spherical shape, and that almost no unreacted monomer remains in the liquid crystal droplet 9. With such a structure of the liquid crystal droplet, the optical hysteresis can be reduced and the contrast can be improved. The reason will be described later.

[Manufacturing Method of Liquid Crystal Display Element] The liquid crystal display element having the above structure was manufactured by the following method.

(1) Step of Fabricating Empty Cell First, a polyimide film SE-7992 as an insulating film is formed on a transparent glass substrate (corresponding to a lower substrate) 2 on which a transparent electrode (corresponding to a pixel electrode) 5 made of ITO is formed. (Nissan Chemical)
Is applied by a spinner to form an insulating film 6. Similarly, a polyimide film SE-7992 (manufactured by Nissan Chemical Industries) is applied as an insulating film on a transparent glass substrate (corresponding to an upper substrate) 3 on which a transparent electrode (corresponding to a counter electrode) 7 made of ITO is formed by a spinner. Thus, an insulating film 8 is formed. Next, the transparent glass substrate 2 and the transparent glass substrate 3 are bonded via a 12 μm-diameter plastic spacer (Micropearl: Sekisui Fine Co., Ltd.) to a thermosetting sealing material (Stract Bond: Mitsui Toatsu Chemicals, Inc.). ), A liquid crystal injection port was provided and the substrates were bonded together, and heated at 150 ° C. for 2 hours to completely cure the sealing material, thereby producing empty cells.

(2) Step of preparing mixed composition Next, TL-213 (manufactured by Merck) as a liquid crystal material.
50 g, 0.80 g of 2-ethylhexyl acrylate (manufactured by Tokyo Chemical Industry) as a polymerizable monomer, 0.60 g of polyurethane acrylate as an oligomer, and 0.05 g of Darocure 1173 (Ciba-Geigy Corporation) as a photopolymerization initiator were added. The mixed composition
The mixture was sufficiently stirred at 25 ° C. to prepare a uniform mixed solution.

(3) Step of Injecting Mixed Composition The above mixed solution is vacuum-injected into the empty cell at 25 ° C. from a sealing portion, and then the solution is applied with Loctite (Nippon Loctite Co., Ltd.) which is a UV-curable sealing resin. The sealing part was sealed.

(4) First UV Irradiation Step Next, the liquid crystal cell is irradiated with ultraviolet rays from a high-pressure mercury lamp of 200 mW / cm ² at 25 ° C. for t1 = 5 seconds, as shown in the sequence shown in FIGS. Then, the polymerizable monomer was polymerized by a reaction with a photopolymerization initiator to cause phase separation. In addition, at the time of ultraviolet irradiation, in order to prevent decomposition of the liquid crystal, the liquid crystal was passed through an ultraviolet cut filter UV-35 (Toshiba Glass Co., Ltd.).
Further, in order to prevent heat generation of the liquid crystal cell, an ultraviolet / infrared reflection filter UVIR (Geomatec) was passed.

When the intensity of the ultraviolet light is high, the polymerization rate is high, so that the structure of the separated and precipitated liquid crystal droplet is close to a spherical shape. This means that a liquid crystal droplet structure with reduced hysteresis was obtained. The reason will be described below. Generally, it is considered that the occurrence of hysteresis is caused by the structure of the liquid crystal droplet. That is,
If the liquid crystal droplet has a distorted shape or is close to a network structure, the interface between the liquid crystal and the polymer is uneven compared to a spherical one, so that disclination is easily trapped. As a result, It is believed that the hysteresis increases. Therefore, if the liquid crystal droplet has a structure close to a spherical shape as in the present embodiment, it becomes difficult to trap the disclination, and as a result, the hysteresis can be reduced.

However, since the intensity of ultraviolet rays is large, rapid polymerization is carried out, and a large amount of unreacted monomer remains in the liquid crystal droplet. Therefore, in this state, although the liquid crystal droplet is close to a spherical shape, the hysteresis can be reduced.
Due to the unreacted monomer in the liquid crystal droplet, the apparent refractive index anisotropy becomes small and the scattering property is poor, so that sufficient contrast cannot be obtained. Therefore, second ultraviolet irradiation described below is performed.

(5) Second UV Irradiation Step After the phase separation of the liquid crystal is achieved by the above-mentioned first UV irradiation, UV light is continuously irradiated at a UV intensity lower than the UV intensity at the time of the first UV irradiation. The second UV intensity, as in the sequence shown in FIGS. 2 and 3, the UV light generated by a high pressure mercury lamp of 30 mW / cm ² 25
Further irradiation was performed at 100C for t2-t1 = 100 seconds to cure the polymerizable monomer more completely. Note that, also in the second ultraviolet irradiation step, the ultraviolet light is irradiated with the ultraviolet cut filter UV.
-35 and a UV / IR reflection filter UVIR.

As described above, the liquid crystal display element 1 was manufactured through the steps (1) to (5).

[Evaluation of Liquid Crystal Cell] With respect to the liquid crystal display device manufactured by the above method, the structure of liquid crystal droplets, the scattering property, the amount of residual monomers in the liquid crystal droplets, and the hysteresis were evaluated.

Structure of Liquid Crystal Droplet The polymer dispersion type liquid crystal display element thus completed is disassembled,
The liquid crystal material was washed away with isopropyl alcohol, and the phase separation structure of the polymer-dispersed liquid crystal was observed with an optical microscope. As a result, the liquid crystal droplet was nearly spherical and had a particle size of 1.0.
μm to 1.2 μm.

Scattering property Next, as an index for quantifying the scattering property of the polymer-dispersed liquid crystal, the scattering property of the liquid crystal cell manufactured by the above method was evaluated using the scattering gain G. Here, the scattering gain G is
Assuming that the illuminance on the light-irradiated surface of the polymer-dispersed liquid crystal is E, the luminance on the surface opposite to the light-irradiated side of the polymer-dispersed liquid crystal is B, and the pi is π, the following equation is defined. .

G = πB / E As a specific measuring method, light is irradiated in parallel to the substrate surface of the polymer dispersed liquid crystal cell, and an illuminometer (Minolta) arranged on the substrate surface of the polymer dispersed liquid crystal cell is used. Illuminance E by T-1M)
Was measured. The luminance B on the surface of the polymer dispersed liquid crystal on the side opposite to the light irradiation side was measured using a luminance meter (BM-produced by TOPCON).
8). When the polymer-dispersed liquid crystal is a perfect scatterer, the scattering gain G is 0.5. The contrast of the polymer-dispersed liquid crystal is proportional to the reciprocal of the scattering gain G.

When the gain G of the above cell is measured, G = 0.
It was 85, indicating that the scattering properties were good.

The scattering gain G is described in "Liquid Crystal Video Projector Technology (published by Trikeps)" (Sasaki
Shin, 1990, 10.29, p139).

Amount of Residual Monomer in Liquid Crystal Droplet The amount of residual monomer in the liquid crystal drop was evaluated using the nematic-isotropic transition point of the liquid crystal drop. Specifically, the nematic-isotropic transition point (the highest temperature at which liquid crystallinity can be maintained) Tni of the liquid crystal droplet of the cell.
Was 82.7 ° C. as measured by METTLER FP800. Since the Tni of the TL-213 liquid crystal is 87.7 ° C., it is recognized that a small amount of unreacted resin monomer is contained in the completed cell. However, as described later, the amount of unreacted resin monomer in the liquid crystal droplet is smaller than that in the case where only the first ultraviolet irradiation step is performed. Thereby, it is recognized that the scattering property was improved. Here, the amount of the residual monomer in the liquid crystal droplet can be evaluated based on the nematic-isotropic transition point Tni because, when an impurity other than the liquid crystal is present in the liquid crystal droplet, the nematic-isotropy is determined according to the amount of the impurity. This is because the tropic transition point Tni decreases.

Since the Tni of the liquid crystal cell according to the present invention is high, the scattering gain is small even at a high operating temperature and good characteristics are exhibited.

Hysteresis FIG. 4 shows the change in transmittance of the polymer-dispersed liquid crystal cell produced in the present example with the applied voltage measured by a luminance meter. The measurement was performed by applying a 30 Hz rectangular wave at a measurement temperature of 30 ° C. and a light receiving angle of 0.2 °.

The curve 30a shows the transmittance characteristics when the applied voltage is increased from 0V, and the curve 30b shows the transmittance characteristics when the applied voltage is reduced from 30V. Both curves did not follow the same path, and hysteresis was observed. Normally, the hysteresis value is defined by a voltage difference ΔV at the center of the transmittance change between 30a and 30b, but what is observed in actual display is a transmittance difference ΔT at a constant voltage (V1).
It is. A place where the hysteresis at the transmittance is the largest is called a maximum hysteresis (シ ス Tmax).
The maximum hysteresis ΔTmax of the polymer-dispersed liquid crystal cell manufactured in this example was 1.0%, indicating that the hysteresis was reduced.

[Ratio of First Ultraviolet Light Intensity to Second Ultraviolet Light Intensity] Next, only the second ultraviolet light intensity and the second ultraviolet irradiation time are set to the conditions shown in Table 1 below, and the other conditions are the same as in the above method. Thus, liquid crystal cells A, B, and C were manufactured. The second
The irradiation temperature in the ultraviolet irradiation step was 25 ° C., the same as the irradiation temperature in the first ultraviolet irradiation step.

[Table 1]

Here, the reason why the irradiation time is changed depending on the intensity of the ultraviolet light is to make the amount of ultraviolet light irradiation = intensity × time constant. If this changes, the amount of decomposition of the liquid crystal material by ultraviolet rays and the amount of polymerization of the residual resin monomer cannot be made constant. The conditions such as the ultraviolet cut filter were the same.

At this time, the maximum hysteresis ΔTmax, the gain G, and the nematic-isotropic transition point T in the cell transmittance of each of the liquid crystal cells A, B, and C.
Since ni was measured, the results are also shown in Table 1. As is apparent from Table 1, when the second ultraviolet light intensity is 1/5 or less of the first ultraviolet light intensity, it is recognized that the gain G, that is, the contrast is greatly improved.

A cell irradiated with ultraviolet light at an intensity of 200 mW / cm ² for only t1 = 3 seconds was observed. As a result, it was confirmed that the scattering property was not sufficient and the phase separation of the liquid crystal was incomplete.

Comparative Example 1 The composition of the liquid crystal cell and the components of the homogeneous mixed solution were exactly the same. UV irradiation from a high-pressure mercury lamp of 300 mW / cm ² at 25 ° C., UV irradiation amount = intensity × time = 1000
(MJ / cm ² ) (constant) to obtain a cell.

FIG. 5 is a graph in which the maximum hysteresis ΔTmax and the gain G in these cells are plotted against the intensity of ultraviolet irradiation. In FIG. 6, the scattering gain is large when the intensity of the ultraviolet light is very low. This is because the average diameter of the liquid crystal droplet is large in this region, and the scattering performance is lowered. As can be seen from FIGS. 5 and 6, there is a nearly trade-off relationship between the hysteresis and the scattering gain G. In one ultraviolet irradiation step, the maximum hysteresis ΔTmax = 1.0% and the gain G = 1.
0 is the limit and the maximum hysteresis リ Tmax = 1.0
It is difficult to further increase the gain G while maintaining%.

The cause is considered as follows.

When irradiated with strong ultraviolet rays, the disclination is apt to disappear, and the hysteresis performance is improved as shown in FIG. 5, but the phase separation occurs rapidly, so that it should originally move toward the polymer matrix wall. A large amount of unreacted resin monomer tends to remain in the liquid crystal droplets, the apparent refractive index anisotropy Δn of the liquid crystal decreases, and the scattering gain, that is, the contrast decreases. Conversely, when irradiating weak ultraviolet light, as shown in FIG. 5, the hysteresis performance is deteriorated, but the phase separation occurs slowly, so that unreacted resin monomer hardly remains in the liquid crystal droplets. And the scattering properties are improved. This means
This can also be explained from the fact that the cells having higher UV intensity have lower Tni points. Therefore, in one ultraviolet irradiation process, there is almost a trade-off relationship between hysteresis performance and scattering gain with respect to intensity.

However, when the manufacturing method of the first embodiment is used, the maximum hysteresis ΔTmax = is maintained at 1.0% by the first irradiation with the large ultraviolet intensity (the phase separation structure of the liquid crystal is the first type). A cell having a favorable scattering gain can be produced by the second low-intensity ultraviolet irradiation for polymerizing the remaining resin monomer.

Further, since the Tni of the liquid crystal cell according to the present invention is at a high temperature, the decrease in the refractive index anisotropy Δn with respect to the temperature is small. Indicated.

(Embodiment 2) In Embodiment 2, the first
The spectral characteristics of the ultraviolet rays in the ultraviolet irradiation step are different from the spectral characteristics of the ultraviolet rays in the second ultraviolet irradiation step. Specifically, it is as follows.

In the same manner as in the first embodiment, the liquid crystal cell in which the homogeneous mixed solution was vacuum-injected and sealed was passed through an ultraviolet cut filter UV-35 (Toshiba Glass Co., Ltd.).
After irradiating ultraviolet rays from a high-pressure mercury lamp of mW / cm ² at 25 ° C. for 5 seconds (first ultraviolet ray irradiation) to separate phases, subsequently, 50 mW passed through an ultraviolet ray cut filter UV-37 (Toshiba Glass Co., Ltd.). UV light from a high-pressure mercury lamp of / cm ² was further irradiated at 25 ° C. for 100 seconds (second UV irradiation) to cure the polymerizable monomer more completely.

The maximum hysteresis of this liquid crystal cell, ΔTma
x, the gain G and the nematic-isotropic transition point Tni, the maximum hysteresis △ Tmax
= 1.0%, gain G = 0.80, Tni = 84.0 ° C.
And showed good characteristics.

The reason why good characteristics are exhibited is considered as follows.

When the liquid crystal cell filled with the homogeneous mixed solution is irradiated with ultraviolet rays, the Tni point rapidly rises with the irradiation time at the beginning of the irradiation, reaches a maximum value at a certain point, and then decreases when the irradiation is further performed. There is a tendency. This is because the reduction in Tni due to the decomposition of the liquid crystal material by ultraviolet rays and the improvement in Tni due to the polymerization of the resin monomer are in competition, and the rapid increase in Tni in the initial stage is due to the improvement in Tni due to the polymerization of the resin monomer. The decrease in Tni in the latter half is due to decomposition of the liquid crystal material by ultraviolet rays.

On the other hand, Darocure 117 which is a polymerization initiator
3 (corresponding to the wavelength range in which the polymerization initiator is activated) is larger than 370 nm, while the liquid crystal material T
The absorption wavelength region of L-213 (corresponding to the wavelength region in which the liquid crystal material undergoes photolysis) is smaller than 360 nm. Therefore, in the second ultraviolet irradiation step, a UV-ray having a cut wavelength of 370 nm is used.
By irradiating the liquid crystal cell with ultraviolet light that has passed through 37, it is possible to realize a situation in which the unreacted resin monomer is polymerized but the liquid crystal material does not undergo photodecomposition, so that the Tni point can be increased, and therefore the apparent refractive index anisotropy can be increased. Since the property Δn does not decrease, the scattering gain can be improved.

When the second ultraviolet intensity is weaker than the first ultraviolet intensity, the reaction proceeds more slowly, and the unreacted resin monomer easily reacts with the resin matrix wall, so that the Tni point can be further increased. Does not decrease, so that the scattering gain can be improved.

In the above example, one ultraviolet light source and two ultraviolet cut filters are used to make the spectral characteristics of ultraviolet light different between the first ultraviolet light irradiation step and the second ultraviolet light irradiation step. The spectral characteristics of the ultraviolet rays in the first ultraviolet irradiation step and the second ultraviolet irradiation step may be made different using two ultraviolet light sources having different spectral characteristics.

(Embodiment 3) As in the sequence shown in FIG. 7 and FIG. 8, ultraviolet rays from a high-pressure mercury lamp of 200 mW / cm ² were applied to the above-mentioned liquid crystal cell in which a homogeneous mixed solution was vacuum-injected and sealed as in Example 1. At 25 ° C. for t1 = 5 seconds (irradiation of the first ultraviolet ray), and after the phase separation, the cell temperature was set at 5 ° C.
C., followed by irradiating ultraviolet rays from a high-pressure mercury lamp of 30 mW / cm ² for t2-t1 = 100 seconds (second ultraviolet ray irradiation) to cure the polymerizable monomer more completely.

The maximum hysteresis of this liquid crystal cell ΔTma
x, the gain G and the nematic-isotropic transition point Tni, the maximum hysteresis △ Tmax
= 1.0%, gain G = 0.81, Tni = 83.5 ° C.
And showed good characteristics.

The reason why good characteristics are exhibited is considered as follows.

That is, by cooling the liquid crystal cell at the time of the second ultraviolet irradiation, the decomposition of the liquid crystal material by the ultraviolet light is suppressed, but the polymerization of the unreacted resin monomer is not so much suppressed, and as a result, Tni is increased. Because it is considered to be.

(Embodiment 4) In the same manner as in Embodiment 1, a uniform mixed solution is vacuum-injected and the above-mentioned liquid crystal cell is sealed, and FIG.
And 200 mW / c as in the sequence shown in FIG.
Irradiation with ultraviolet light from a high-pressure mercury lamp of m ² at 25 ° C. for t1 = 5 seconds (irradiation of first ultraviolet light), phase separation, and then heating the cell temperature to 105 ° C., and in that state, a high-pressure mercury lamp of 30 mW / cm ² Was irradiated for 100 seconds (second UV irradiation) to cure the polymerizable monomer more completely.

The maximum hysteresis of this liquid crystal cell, ΔTma
x, the gain G and the nematic-isotropic transition point Tni, the maximum hysteresis △ Tmax
= 1.0%, gain G = 0.82, Tni = 83.3 ° C.
And showed good characteristics.

The reason why good characteristics are exhibited is considered as follows.

That is, by heating the liquid crystal cell to the nematic-isotropic transition point Tni during the second ultraviolet irradiation, the unreacted resin monomer trapped in the liquid crystal droplet can be completely diffused. ,
Since the content of the unreacted resin monomer in the liquid crystal droplet is reduced by efficiently binding to the polymer matrix wall, Tni
Is considered to increase, and the apparent Δn increases to improve the scattering property.

(Embodiment 5) In the same manner as in Embodiment 1, a uniform mixed solution was vacuum-injected and sealed in the liquid crystal cell as shown in FIG.
1 and the sequence shown in FIG.
Irradiation with ultraviolet light from a high-pressure mercury lamp of cm ² at 25 ° C. for t1 = 5 seconds (irradiation of first ultraviolet light), phase separation was performed, the cell temperature was once heated to 105 ° C., and t2−t1 = 6 in that state.
After standing for 00 seconds, the temperature was returned to 25 ° C. and 30 mW / cm ²
UV light from a high-pressure mercury lamp was irradiated for t3-t2 = 100 seconds (second UV irradiation) to cure the polymerizable monomer more completely.

The maximum hysteresis of this liquid crystal cell, ΔTma
x, the gain G and the nematic-isotropic transition point Tni, the maximum hysteresis △ Tmax
= 1.0%, gain G = 0.82, Tni = 83.4 ° C.
And showed good characteristics.

The reason why good characteristics are exhibited is considered as follows.

That is, by heating the liquid crystal cell to the nematic-isotropic transition point Tni after the first ultraviolet irradiation, the unreacted resin monomer trapped in the liquid crystal droplet can be completely diffused. ,
After that, even when the temperature is returned to 25 ° C. and the second ultraviolet ray is irradiated, the Tni rises and the apparent Δ increases because the unreacted resin monomer content in the liquid crystal droplet can be reduced by efficiently binding to the polymer matrix wall. This is because it is considered that n increased and the scattering property was improved.

Although the effect was observed even at a heating temperature of 60 to 70 ° C., it is desirable to heat the cell to the nematic-isotropic transition point Tni in order to improve the effect in a shorter time.

(Embodiment 6) In Embodiment 6, the ultraviolet irradiation time in the first ultraviolet irradiation step is the time required to reach the maximum point in the nematic-isotropic transition point-ultraviolet irradiation time characteristic curve of the liquid crystal. It is characterized by being within. Hereinafter, a specific description will be given.

As in the first embodiment, the liquid crystal cell sealed by vacuum injection of the homogeneous mixed solution was irradiated with ultraviolet rays from a high-pressure mercury lamp of 200 mW / cm ² while keeping the temperature at 25 ° C. Was prepared. After the first UV irradiation step, 3
Ultraviolet light from a high-pressure mercury lamp of 0 mW / cm ² was irradiated for 100 seconds (second ultraviolet irradiation) to cure the polymerizable monomer more completely.

FIG. 13 is a plot of the relationship between the nematic-isotropic transition point Tni at the end of the first ultraviolet irradiation and the ultraviolet irradiation time.

The liquid crystal cell at the irradiation times t4, t5 and t6 was irradiated with the second ultraviolet ray to obtain the maximum hysteresis Δ
When Tmax, gain G and nematic-isotropic transition point Tni are measured, in the case of irradiation time t4, (） Tmax, G, Tni) = (1.0%, 1.
2, 75.5 ° C.), and in the case of the irradiation time t5,
(△ Tmax, G, Tni) = (1.0%, 0.86,
82.5 ° C.), and in the case of the irradiation time t6, (ΔT
max, G, Tni) = (1.0%, 0.88, 81.
5 ° C.). As is clear from the measurement results, the liquid crystal cell having the irradiation time t5 at which the nematic-isotropic transition point becomes the maximum from the time t4 exhibited the best characteristics. In a liquid crystal cell in which the first ultraviolet irradiation time is shorter than t4, Tni after the end of the second ultraviolet irradiation is 84.1 ° C.
However, the liquid crystal droplet was large and the scattering gain was large.

The reason why the liquid crystal cell from t4 to t5 exhibited good characteristics is considered as follows.

When the liquid crystal cell filled with the homogeneous mixed solution is irradiated with ultraviolet rays, as shown in FIG. 13, the Tni point rapidly increases with the irradiation time at the beginning of the irradiation, reaches a maximum value at a certain point, and further increases. This decrease is due to the competition between the reduction of Tni due to the decomposition of the liquid crystal material by ultraviolet rays and the improvement of Tni due to the polymerization of the resin monomer. Derived from the improvement of Tni by monomer polymerization,
The decrease in i is due to the decomposition of the liquid crystal material by ultraviolet rays.

Therefore, in order to obtain a polymer-dispersed liquid crystal having good characteristics, the apparent Δn due to the decomposition of the liquid crystal material is not obtained by long-term irradiation of ultraviolet light such that the unreacted residual resin monomer is completely polymerized. FIG.
Good characteristics should not be obtained unless the irradiation time is around t5.

However, in the case of only one ultraviolet irradiation, the characteristic is best around t5. However, in this state, a large amount of unreacted resin monomer remains in the liquid crystal droplet.
Some liquid crystal materials have already been decomposed. Therefore, when performing two-stage polymerization, it can be said that the vicinity immediately after the completion of the liquid crystal droplet (liquid crystal droplet by phase separation) structure is most desirable. This is because the structure in a state before this state undergoes a change in the structure due to the irradiation of the second ultraviolet ray, and the hysteresis deteriorates.

(Other Matters) In the above embodiment, the temporal change of the ultraviolet intensity is stepped, but the present invention is not limited to this, and the same effect can be obtained even if it changes continuously. Needless to say,

Further, in the above embodiment, the ultraviolet irradiation is performed in the first and second stages, but the present invention is not limited to this, and the ultraviolet irradiation may be performed in three or more stages. Needless to say, a great effect can be obtained.

[0100]

As described above, according to the present invention, the decomposition of the liquid crystal can be suppressed as much as possible without sacrificing the hysteresis performance, and the unreacted resin monomer can be polymerized as efficiently as possible. A polymer dispersion type liquid crystal display element having excellent scattering properties, high contrast performance, and excellent display quality can be manufactured because the residual resin monomer is small, the Tni is high, and the apparent Δn is large.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one pixel of a liquid crystal display element according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a change in ultraviolet intensity and an irradiation time in a first ultraviolet irradiation step and a second ultraviolet irradiation step in the method for manufacturing a liquid crystal display element according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a change in panel temperature and an irradiation time in a first ultraviolet irradiation step and a second ultraviolet irradiation step in the method for manufacturing a liquid crystal display element according to the first embodiment of the present invention.

FIG. 4 is an applied voltage-transmittance characteristic diagram of the liquid crystal display element according to Embodiment 1 of the present invention.

FIG. 5 is a diagram showing a relationship between ultraviolet intensity and hysteresis of the liquid crystal display element according to Comparative Example 1.

FIG. 6 is a diagram illustrating a relationship between an ultraviolet intensity and a scattering gain of the liquid crystal display element according to Comparative Example 1.

FIG. 7 is a diagram showing a change in intensity of ultraviolet rays and an irradiation time in a first ultraviolet irradiation step and a second ultraviolet irradiation step in the method for manufacturing a liquid crystal display element according to Embodiment 3 of the present invention.

FIG. 8 is a diagram showing a change in panel temperature and an irradiation time in a first ultraviolet irradiation step and a second ultraviolet irradiation step in the method for manufacturing a liquid crystal display element according to Embodiment 3 of the present invention.

FIG. 9 is a diagram showing a change in ultraviolet intensity and an irradiation time in a first ultraviolet irradiation step and a second ultraviolet irradiation step in the method for manufacturing a liquid crystal display element according to the fourth embodiment of the present invention.

FIG. 10 is a diagram showing a change in panel temperature and an irradiation time in a first ultraviolet irradiation step and a second ultraviolet irradiation step in a method for manufacturing a liquid crystal display element according to Embodiment 4 of the present invention.

FIG. 11 is a diagram showing a change in ultraviolet intensity and an irradiation time in a first ultraviolet irradiation step and a second ultraviolet irradiation step in the method for manufacturing a liquid crystal display element according to the fifth embodiment of the present invention.

FIG. 12 is a diagram showing a change in panel temperature and an irradiation time in a first ultraviolet irradiation step and a second ultraviolet irradiation step in the method for manufacturing a liquid crystal display element according to the fifth embodiment of the present invention.

FIG. 13 is a diagram showing a relationship between an ultraviolet irradiation time and a nematic-isotropic transition point of a liquid crystal display element according to a fifth embodiment of the present invention.

[Explanation of symbols]

1: liquid crystal display element 2: lower substrate 3: upper substrate 4: polymer / liquid crystal composite layer 5: pixel electrode 6, 8: insulating film 7: counter electrode 9: polymer matrix 10: liquid crystal droplet 30a: rectangular wave voltage 30b: Transmittance characteristics when a rectangular wave voltage is applied to a liquid crystal cell (30V → 0V)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H088 FA10 FA20 FA30 GA10 HA08 KA03 MA06 MA16 2H089 HA04 JA04 KA08 LA07 LA19 MA04X NA09 NA24 NA39 QA05 QA11 QA12 QA16 SA18 TA02

Claims (11)

[Claims] 1. A liquid crystal device comprising: a pair of substrates; a liquid crystal layer sandwiched between the pair of substrates; and an electrode for applying a voltage to the liquid crystal layer, wherein the liquid crystal layer includes a polymer containing a polymer phase and a liquid crystal phase. A method for manufacturing a liquid crystal display device comprising a liquid crystal composite layer, comprising: a mixed composition injecting step of injecting a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates; A first ultraviolet irradiation step of irradiating, in which the polymer and the liquid crystal are phase-separated by photopolymerization of the photopolymerizable material, and the shape of the separated and precipitated liquid crystal droplet is substantially spherical. A first ultraviolet irradiation step of irradiating ultraviolet light under conditions, and a second ultraviolet irradiation step of irradiating ultraviolet light under second irradiation conditions to further polymerize the unreacted polymerizable material remaining in the liquid crystal droplet. And a method for manufacturing a liquid crystal display element, comprising: Law. 2. A liquid crystal device comprising: a pair of substrates; a liquid crystal layer sandwiched between the pair of substrates; and an electrode for applying a voltage to the liquid crystal layer, wherein the liquid crystal layer includes a polymer containing a polymer phase and a liquid crystal phase. A method for manufacturing a liquid crystal display device comprising a liquid crystal composite layer, comprising: a mixed composition injecting step of injecting a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates; A first ultraviolet irradiation step of irradiating, wherein the polymer and the liquid crystal are phase-separated by photopolymerization of the photopolymerizable material, and the shape of the separated and precipitated liquid crystal droplet is substantially spherical. A first ultraviolet irradiation step of irradiating ultraviolet light at a high intensity, and an ultraviolet light of a second ultraviolet intensity lower than the first ultraviolet intensity to further polymerize the unreacted polymerizable material remaining in the liquid crystal droplet. A second ultraviolet irradiation step of irradiating
A method for manufacturing a liquid crystal display device, comprising: 3. The method according to claim 2, wherein a ratio between the first ultraviolet light intensity and the second ultraviolet light intensity is 5 or more. 4. A liquid crystal device comprising: a pair of substrates; a liquid crystal layer sandwiched between the pair of substrates; and an electrode for applying a voltage to the liquid crystal layer, wherein the liquid crystal layer includes a polymer containing a polymer phase and a liquid crystal phase. A method for manufacturing a liquid crystal display device comprising a liquid crystal composite layer, comprising: a mixed composition injecting step of injecting a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates; A first ultraviolet irradiation step of irradiating, wherein the polymer and the liquid crystal are phase-separated by photopolymerization of the photopolymerizable material, and the shape of the separated and precipitated liquid crystal droplet is substantially spherical. A first ultraviolet irradiation step of irradiating ultraviolet light having spectral characteristics; and a longer wavelength component than the first ultraviolet spectral characteristics in order to further polymerize the unreacted polymerizable material remaining in the liquid crystal droplet. Irradiation with ultraviolet light having second ultraviolet spectral characteristics And a second ultraviolet irradiation step. 5. In the first ultraviolet irradiation step, irradiation is performed through a first ultraviolet cut filter that cuts a component having a wavelength equal to or less than a predetermined first wavelength out of wavelength components of the ultraviolet light, 5. The method for manufacturing a liquid crystal display element according to claim 4, wherein in the step of irradiating the ultraviolet light, the light is radiated through a second ultraviolet cut filter that cuts a component having a second wavelength or less that is longer than the first wavelength. . 6. The method according to claim 5, wherein the ultraviolet intensity in the second ultraviolet irradiation step is lower than the ultraviolet intensity in the first ultraviolet irradiation step. 7. A liquid crystal device comprising: a pair of substrates; a liquid crystal layer sandwiched between the pair of substrates; and an electrode for applying a voltage to the liquid crystal layer, wherein the liquid crystal layer includes a polymer containing a polymer phase and a liquid crystal phase. A method for manufacturing a liquid crystal display device comprising a liquid crystal composite layer, comprising: a mixed composition injecting step of injecting a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates; A first ultraviolet irradiation step of irradiating the first substrate, wherein the polymer and the liquid crystal are phase-separated by photopolymerization of the photopolymerizable material, and the shape of the separated and precipitated liquid crystal droplet is substantially spherical. A first ultraviolet irradiation step of irradiating ultraviolet light at a temperature; and a second substrate temperature lower than the first substrate temperature to further polymerize the unreacted polymerizable material remaining in the liquid crystal droplet. A second ultraviolet irradiation step of irradiating ultraviolet rays with A method for manufacturing a liquid crystal display element, comprising: 8. The method according to claim 7, wherein the second substrate temperature is equal to or higher than a nematic-isotropic transition point of the liquid crystal after the first ultraviolet irradiation step. 9. A liquid crystal device comprising: a pair of substrates; a liquid crystal layer sandwiched between the pair of substrates; and an electrode for applying a voltage to the liquid crystal layer, wherein the liquid crystal layer includes a polymer containing a polymer phase and a liquid crystal phase. A method for manufacturing a liquid crystal display device comprising a liquid crystal composite layer, comprising: a mixed composition injecting step of injecting a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates; A first ultraviolet irradiation step of irradiating, wherein the polymer and the liquid crystal are phase-separated by photopolymerization of the photopolymerizable material, and the shape of the separated and precipitated liquid crystal droplet is substantially spherical. A first ultraviolet irradiation step of irradiating ultraviolet light with high intensity, a heating step of heating the substrate, and cooling the substrate. In this cooled state, the unreacted polymerizable material remaining in the liquid crystal droplet is further removed. In order to polymerize, the first ultraviolet light intensity weaker than the first ultraviolet light intensity Method for manufacturing a liquid crystal display device of the second ultraviolet irradiation step of irradiating ultraviolet rays in UV intensity, characterized in that it comprises a. 10. The method according to claim 9, wherein a heating temperature in the heating step is equal to or higher than a nematic-isotropic transition point of liquid crystal. 11. A liquid crystal display comprising: a pair of substrates; a liquid crystal layer sandwiched between the pair of substrates; and an electrode for applying a voltage to the liquid crystal layer.
A method for manufacturing a liquid crystal display device, wherein the liquid crystal layer comprises a polymer / liquid crystal composite layer including a polymer phase and a liquid crystal phase, comprising a mixed composition containing a liquid crystal material and a photopolymerizable material between a pair of substrates. A mixed composition injecting step of injecting, and a first ultraviolet irradiation step of irradiating the mixed composition with ultraviolet rays, wherein the polymer and the liquid crystal are phase-separated by photopolymerization of the photopolymerizable material, and separated and precipitated. A first ultraviolet irradiation step of irradiating ultraviolet rays within a time required to reach a maximum point in a nematic-isotropic transition point-ultraviolet irradiation time characteristic curve of the liquid crystal so that the shape of the liquid crystal droplet becomes substantially spherical, A second ultraviolet irradiation step of irradiating ultraviolet rays at a second ultraviolet intensity lower than the first ultraviolet intensity so as to further polymerize the unreacted polymerizable material remaining in the liquid crystal droplet;
A method for manufacturing a liquid crystal display device, comprising: