JPH03278024A - High-polymer liquid crystal composite and production thereof - Google Patents

Abstract

PURPOSE:To easily allow writing of patterns without impression of electric fields by writing the patterns while utilizing the phase sepn. and change of a liquid crystal which arise according to the polymn. conditions of a high-polymer matrix. CONSTITUTION:The writing of the patterns is executed by utilizing the phase sepn. and change of the liquid crystal which arise according to the polymn. conditions, such as temp. and light intensity, of the high-polymer matrix. Namely, a soln. mixture 30 contg. the high-polymer MA of a polymer or oligomer and the liquid crystal molecules MB is held between supports 32 and 34 and a light shielding mask 36 is formed on the base 32. The soln. mixture 30 is set at such a temp. at which the soln. mixture is maintained at the temp. below the nematic to isotropic transition point of the liquid crystal. The soln. mixture is then irradiated with light which causes a polymn. reaction, for example, UV rays. The polymn. reaction is effected in the part irradiated with the UV rays. The liquid crystal drops MC are then separated in phase and are formed in the high-polymer matrix. The soln. mixture 30 is then set at the temp. higher than the temp. in the process of the previous stage and is irradiated with the light over the entire part, by which the polymn. is effected. The patterns are easily written when the electric fields are not impressed to the soln. in such a manner.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a polymer liquid crystal composite in which a liquid crystal exists in a polymer matrix in a phase-separated manner, and a method for producing the same. The present invention relates to a polymer liquid crystal composite suitable for use as a light control glass or a display element capable of recording a pattern addressed to a target and arbitrarily varying its light transmittance, and a method for manufacturing the same.

[Prior Art] Conventionally, as a pattern display means using liquid crystal, there is an electrical addressing method in which electrodes for driving the liquid crystal are microfabricated into a desired pattern. According to this method, it is relatively easy to display a simple pattern such as a time display, but it is difficult to display a complex pattern. Another method is to record patterns on smectic liquid crystals by laser thermal writing. Although this method has the feature of being reversible, it requires rewriting the pattern when erasing the recorded pattern and displaying the same pattern again. This writing takes a long time, and furthermore, the written pattern information has the disadvantage of being sensitive to heat.

Incidentally, in recent years, polymer liquid crystal composites in which liquid crystals are dispersed in a polymer matrix have been attracting attention. Examples of such polymer liquid crystal composites include, for example, Patent Publication No. 502128 of 1988 and Patent Publication No. 5016 of 1988.
There is one disclosed in Publication No. 31, Proceedings of the 38th Polymer Symposium, pages 2151 to 2156.

The polymer liquid crystal composite is, for example, a polymer oligomer.

It is obtained by irradiating a mixed solution of a monomer, liquid crystal, and a polymerization initiator with ultraviolet rays.

If a display means is constructed using such a polymer liquid crystal composite, it is possible to write and read out complex patterns, as disclosed in, for example, the proceedings of the 38th Polymer Symposium, pages 2157 to 2159. can be easily performed.

FIG. 13 shows such a conventional polymer liquid crystal composite. In the figure, a mixed solution 10 containing a polymer M1 and a liquid crystal molecule M2 is held between transparent electrodes 12 and 14, and a light shielding mask 16 having a desired pattern is formed on the electrodes 12 ( (See figure (A)). On the other hand, ultraviolet rays are irradiated while a suitable voltage is applied between the electrodes 12 and 14 by the power source 18 (see the arrow in FIG. 2B). The ultraviolet rays are patterned by the light-shielding mask 16 and enter the mixed solution 10. Therefore, a polymerization reaction occurs in the portion where the ultraviolet rays are incident, and liquid crystal droplets M3 are phase-separated and formed in the polymer matrix. Next, the application of voltage by the power source 18 is stopped, and the entire structure is irradiated with ultraviolet light (see the arrow in FIG. 3C), and liquid crystal droplets M4 are phase-separated and formed in the polymer matrix.

In this case, the fixed orientation of the liquid crystal changes due to the application of an electric field during one polymerization (see figure (B)), and as the applied electric field increases, the light transmittance of the patterned portion 2OA of the liquid crystal composite 20 increases. I come to do it. Writing of a pattern on the liquid crystal composite 20 is performed by changing the transmittance accompanying the change in the fixed orientation.

The written pattern is displayed as follows. First, in the "ON" state where a driving voltage is applied by an appropriate driving power source 22, the liquid crystal droplet M3. When the M4 molecules are aligned in the same direction, the entire liquid crystal composite 20 becomes transparent (see (D) in the same figure). However, when no driving voltage is applied to ro
In FFJ state.

Only the pattern portion 2OA is transparent, and the non-pattern portion 2OB is opaque (see (E) in the same figure). That is, the written pattern is displayed based on the difference in light transmittance.

In this way, according to the conventional example shown in FIG. 13, since the pattern is written by optical addressing, even a complicated pattern can be written easily. The written pattern can be turned on or off by applying an appropriate driving voltage.
Can be turned off.

[Problem to be solved by the invention ME However, the above-mentioned conventional technology has the following disadvantages.

(1) Since polymerization is performed by applying an electric field during pattern writing, electrodes are always required. Patterns cannot be recorded where there are no electrodes.

(2) Pattern writing is performed using changes in the fixed orientation of liquid crystals caused by an applied electric field during polymerization. In other words, it is not possible to use a material that does not cause a change in fixed orientation or a material that exhibits a small change, and as a result, the range of material selection is limited.

Moreover, it is not easy to improve performance due to such restrictions.

(3) Since an electric field must be applied when recording a pattern, manufacturing methods are limited, and the shape of the product is also limited.

The present invention has been made in view of these points, and it is possible to easily write a pattern without applying an electric field, and also has a wide selection of materials, making it possible to use a polymer that can be applied to a wide range of products. The object of the present invention is to provide a liquid crystal composite and a method for manufacturing the same.

[Means to solve the problem] The present invention relates to temperature control in polymeric matrices.

Patterns are written using changes in phase separation of liquid crystals depending on polymerization conditions such as light intensity.

[Function] According to the present invention, in addition to the phase-separated region of the liquid crystal, the polymer-liquid crystal composite includes a non-phase-separated region where no phase separation occurs, a phase-separated region with different liquid crystal particle sizes, or a region caused by a chain polymerization reaction. The edge portion is formed taking into consideration the required pattern. Each of these parts has a different characteristic of changing light transmittance due to the application of external heat or electric field, so that the pattern is displayed.

[Example] Hereinafter, examples of the polymer liquid crystal composite and the manufacturing method thereof according to the present invention will be described with reference to the accompanying drawings. As is already known, when a mixed solution of liquid crystals and polymeric monomers and oligomers and an ultraviolet polymerization initiator is irradiated with ultraviolet rays, the ultraviolet polymerization intermediary material is decomposed, and the generated radicals cause monomers and oligomers to form. begins to polymerize. A portion of the liquid crystal is incorporated into the polymer matrix, but if its solubility in the polymer matrix is low, it undergoes phase separation and separates into a part (liquid crystal droplet) containing only the liquid crystal and the polymer matrix.

The morphology of the phase-separated liquid crystal droplets varies from spherical to amorphous depending on the materials used and curing conditions. Since the phase-separated liquid crystal is in a random orientation, it strongly scatters light and is visually observed as cloudy.

When an electric field is applied to this, for example, in the case of a nematic liquid crystal with positive dielectric anisotropy, the directors are aligned parallel to the electric field.

Therefore, if the normal axis (no) of the refractive index of the liquid crystal is approximately the same as the refractive index (np) of the polymer matrix, light in a direction parallel to the electric field will be transmitted. When the electric field is stopped, the orientation of the liquid crystal molecules becomes random, and the refractive index (n, ) of the liquid crystal in the extraordinary axis direction and the refractive index of the matrix polymer (n,
The light is scattered due to the difference between p) and p). The present invention takes advantage of the above principles.

First Embodiment> Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. First, the manufacturing method of the first embodiment will be explained with reference to FIG.

In the figure, a mixed solution 30 containing a polymer or oligomer MA and a liquid crystal molecule MB is held between supports 32 and 34 (see (A) in the figure).

A light shielding mask 36 having a desired pattern shape is formed on the support 32. In such a state, first,
J! 15i! curing is performed. That is, the temperature of the mixed solution 30 is set to be below the nematic-isotropic transition point of the liquid crystal, and the light 9, such as ultraviolet rays, which causes the polymerization reaction is irradiated (see the arrow in FIG. 3(B)). The ultraviolet rays are patterned by the light-shielding mask 36 and enter the mixed solution 30. Therefore, a polymerization reaction occurs in the portion where the ultraviolet rays are incident, and liquid crystal droplets MC are phase-separated and formed in the polymer matrix.

Next, a second stage of curing is performed. In this case, the mixed solution 30 is set at a higher temperature than in the first stage process described above. Then, the entire structure is irradiated with light and polymerization is performed (see FIG. 3(C)).

Here, the liquid crystal shape phase-separated in the first stage polymerization process and the liquid crystal shape in the second stage exhibit different optical properties because the solubility of the liquid crystal in the polymer matrix is different. In particular, if curing is performed in the second step under conditions that increase the solubility of the liquid crystal in the polymer matrix, the polymer MA and the liquid crystal MB will no longer phase separate.

Therefore, the non-patterned portion 40B of the polymer liquid crystal composite 40
The part remains transparent (see figure (C)), and the patterned part 40A obtained in the first stage polymerization process is formed in the second stage polymerization process. The transparent non-patterned portion 40B is observed to appear cloudy, rising from the transparent non-patterned portion 40B. This pattern portion 40A becomes transparent when the temperature is increased to a temperature higher than the nematic-isotropic transition point of the liquid crystal. In other words, it has the characteristic that the pattern disappears.

The written pattern can also be displayed as follows. Electrodes 42 and 44 are formed on the liquid crystal composite 40, to which a predetermined drive voltage is applied from a drive power source 46. Then, the alignment direction of the molecules in the liquid crystal droplets MC of the patterned portion 40A of the liquid crystal composite 40 becomes aligned, and the patterned portion 40A becomes transparent (see (D) in the same figure).
reference). Moreover, if the electric field is removed, the molecular orientation becomes random again, and the pattern portion 40A becomes cloudy (see FIG. 4E). On the other hand, the non-patterned portion 40B remains transparent regardless of the presence or absence of an electric field. In this way, the transmittance of the pattern portion can be freely controlled by applying an electric field, and the pattern can be displayed.

Next, an experimental example related to the first embodiment as described above will be explained.

l-Next foot side ↓ BDH's product name E-9 (cyanobiphenyl liquid crystal) as the liquid crystal, 2-ethylhexyl acrylate (EHA) as the monomer, and NIICL of Nippon Kayaku's product name KAYARAD as the oligomer -50 (or HX
620) were mixed at a weight ratio of 6°0:1.6:2.4, and 3% by weight of MERK's Darocurl 173 was added as an ultraviolet polymerization initiator to prepare a mixed solution. This was injected into a cell consisting of two glass substrates with transparent electrodes such as ITO having a gap of 10 μm. Then, as the first stage polymerization process, patterned ultraviolet rays were irradiated for 20 seconds at room temperature (22° C.). The intensity of ultraviolet rays at this time was 1.5 mW/cm2.

Next, as a second stage polymerization process, the cell was heated to 70° C. and uniformly irradiated with ultraviolet rays for 20 seconds. The ultraviolet light intensity is the same as in the j11 stage. The entire cell was transparent during heating in the second stage, but as the temperature decreased, the pattern portion written in the first stage (corresponding to the pattern section 40A) became cloudy and was observed with the naked eye. It became so. Such a change in light transmittance caused by a change in temperature similarly occurred even if the cell was repeatedly heated and cooled.

A 50 Hz sine wave was applied between the transparent electrodes to the cell in which the polymerization reaction was carried out as described above. The relationship between the applied voltage and the light transmittance at this time is shown in FIG. First, in the pattern portion 40A, the light transmittance increases as the voltage increases, as shown by graph LA in the figure. In other words, it changes from a cloudy state to a transparent state. On the other hand, in the non-patterned portion 40B, as shown by graph LB in the figure, the light transmittance hardly changes even if the voltage changes,
It is in a transparent state with high transmittance.

Therefore, when looking at the cell as a whole, as the voltage increases, the pattern of the cured portion in the first stage gradually becomes thinner, until the entire cell becomes transparent and cannot be seen at all. f
This situation is shown in the diagram Ja, where the electrode 42.4
When the voltage from the drive power supply 46 is not applied between the lines 4 and 4, the pattern of the alphabet rAJ, for example, is observed to be cloudy. However, when the voltage of the drive power source 46 is applied and its value exceeds a certain level, the entire cell becomes transparent and the pattern disappears.

Hill - Experimental Example 2 Next, Experimental Example 2 will be explained. This example is Experimental Example 1
The curing temperature in the second stage was changed compared to the above. A cell of the same mixed solution as in Example 1 was prepared,
The curing temperature in the second stage polymerization process was set as low as 40°C.

The pattern portion 40A has a graph LA as in Experimental Example 1. That is, the light transmittance increases as the voltage increases. On the other hand, the non-pattern portion 40B has a graph L in the same figure.
As shown by C, the light transmittance hardly changes even if the voltage changes, and it is in a transparent state with high transmittance. but,
Its transmittance is lower than that of Experimental Example 1.

Therefore, when looking at the cell as a whole, as the voltage increases, the pattern of the hardened part in the first stage gradually becomes thinner, and finally the whole becomes transparent and cannot be seen at all (Figure 3 (A), (B) )reference). However, in this experimental example, since the light transmittance of the cured portion in the second stage is relatively low, when the applied voltage is further increased, the transmittance of the patterned portion 40A exceeds the transmittance of the non-patterned portion 40B. Therefore, as shown in FIG. 3(C), an inverted image of the pattern is observed.

Experimental Example 3 Next, Experimental Example 3 will be explained. This example also applies to Experimental Example 1
The curing temperature in the second stage was changed compared to the above. A cell of the same mixed solution as in Example 1 was prepared,
The curing temperature in the second stage polymerization process was lowered to 30°C.

The patterned portion 40A is the same as in Experimental Example 1, but the non-patterned portion 40B is now shown by graph LD in the figure. In other words, the light transmittance changes slightly as the applied voltage changes.

Therefore, when looking at the cell as a whole, as the applied voltage increases, the transmittance of the pattern portion increases, and the transmittance of other portions also increases, making the cell transparent. The pattern eventually ceases to be observed, but when the voltage is further increased, an inverted image comes to be observed as in Experimental Example 2.

Stop-Next Foot Side A Next, Experimental Example 4 will be explained. In this example, a pattern is written twice. After creating a cell of the same mixed solution as in Experimental Example 1 and curing it in the same manner with patterned light in the first step (see Figure 4 (A))
, and stored in a dark place to avoid exposure to ultraviolet rays. 3 days later,
The first stage curing was performed again with a different pattern of light.

Then, in the second stage polymerization process, the unreacted portion, ie, the portion 400, was cured (see (B) in the same figure).

Even when the pattern is written twice as described above, the liquid crystal droplets MD in the additional pattern section 40C act in the same manner as the liquid crystal droplets MC in the pattern section 40A. Therefore,
Each writing pattern was observed as shown in FIG. 3(A), and when a driving electric field was applied in the same manner as in Experimental Example 1,
No pattern was observed in either case.

In this way, a plurality of patterns can be written in an overlapping manner before the second stage of polymerization and curing. The same applies to the embodiments described later.

l-Experimental Example Next, Experimental Example 5 will be explained. In this example, a guest-host type liquid crystal is used as the liquid crystal.

Merck Japan's guest-host type liquid crystal,
ZLI-3976, 2-ethylhexyl acrylate as a monomer, and Nippon Kayaku ■ brand name K as an oligomer.
7. AYARAD's NαCL-50. OO:0.1
A mixed solution was prepared by mixing at a weight ratio of 2:O, is, and further adding 3% by weight of MERK's Darocurl 173 as an ultraviolet polymerization initiator. This was then polymerized and cured in the same manner as in Experimental Example 1.

In this case, the result was a black pattern on a slightly black transparent background. This is because the liquid crystal uses black dichroic dye. Therefore, by using pleochroic dyes of other colors, it is possible to display in other colors.

As described above, the first embodiment of the present invention has the following effects.

(1) Since it is not necessary to apply an electric field during pattern formation, the manufacturing method is simplified and patterns can be written even in areas where there are no electrodes.

Furthermore, since the display can be controlled by temperature, it can be used as a recording medium without electrodes. Furthermore, it has a wide range of applications in products, such as arranging the necessary electrodes after pattern formation.

(2) It utilizes the universal principle that as the temperature increases, the solubility of the liquid crystal in the polymer matrix during curing increases. Therefore, the combination of the polymer matrix polymer, oligomer, and liquid crystal is arbitrary, and the various required characteristics are exactly the same as when no pattern is recorded, making high-performance optical modulation possible. .

(3) Since the desired pattern is written by optical addressing rather than by heat, optical modulation with high resolution can be performed.

(4) Depending on which part of the characteristics shown in FIG. 2 is utilized, the pattern contrast can be selected from a wide range, and an inverted pattern can also be displayed.

(5) Since the display is performed by light scattering by the liquid crystal droplets, a bright display can be obtained without the need for special means such as a polarizing plate.

(6) If a liquid crystal containing pleochroic dye is used,
Color display is also possible.

(7) Additional writing of patterns is possible before the second stage curing process.

(8) The reaction is irreversible because it utilizes the structural changes of polymer polymerization and liquid crystal phase separation. Therefore, the written pattern is not erased by heat or light and is stable.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. 5 to 7. In the first embodiment described above, phase separation of the liquid crystal does not occur in the non-patterned area, or even if it occurs, the particle size of the liquid crystal droplets is very small. but,
In this example, conditions are set such that the liquid crystal grain size in the non-patterned area is larger than that in the patterned area. Note that the same reference numerals are used for parts structurally corresponding to those of the above embodiment.

1-1 test 1u BDH's E-9 as the liquid crystal, isobutyl acrylate as the monomer, and NαCL-50 of Nippon Kayaku's brand name KAYARAD as the oligomer, 6.70:1.3
A mixed solution 50 was prepared by mixing at a weight ratio of 2:1.98 and further adding 3% by weight of MERK's Darocurl 173 as an ultraviolet polymerization initiator. This was injected into a cell made of two glass substrates with transparent electrodes such as ITO having a gap of 20 μm (see FIG. 5(A)).

Then, as the first stage polymerization process, patterned ultraviolet rays were irradiated at 15° C. for 20 seconds. The intensity of ultraviolet rays at this time was 1.5 mW/cm2 (see (B) in the same figure). At this point, the pattern portion irradiated with ultraviolet rays, that is, the pattern portion 50A of the mixed solution 50, was observed to be cloudy. That is, in the pattern portion 50A, light is scattered by the liquid crystal droplets ME, and the transmittance is low.

Next, the cell after the above steps is heated to 0°C for 30 minutes in a refrigeration means.
The cell was then stored for 20 minutes at a temperature of 0°C, lower than the first stage, and uniformly exposed to ultraviolet light for 20 minutes.
It was irradiated for a second (see figure (C)). The UV intensity is the first
Similar to stages. Then, the entire surface of the cell became cloudy and the pattern disappeared.

This is considered to be due to the fact that light is scattered by liquid crystal droplets in any region of the liquid crystal composite 52. Note that since the temperature at the time of curing is different, the polymer liquid crystal composite 52
The non-pattern part 5 is larger than the liquid crystal droplet ME in the pattern part 52A.
It is thought that the liquid crystal droplets MF of 2B have a larger particle size (see (C) in the same figure).

A 50 Hz sine wave was applied between the transparent electrodes to the cell in which the polymerization reaction was carried out as described above. The relationship between the applied voltage and the light transmittance at this time is shown in FIG. First, the light transmittance of the pattern portion 52A increases as the voltage increases, as shown by the graph LE in the figure. In other words, it changes from a cloudy state to a transparent state. On the other hand,
As shown by graph LG in the figure, the light transmittance of the non-patterned portion 52B increases rapidly as the voltage increases.

Therefore, when looking at the cell as a whole, from a cloudy state, as the voltage increases, the area other than the pattern part gradually becomes transparent.
Finally, everything becomes transparent. FIG. 7 shows such a state, and when the voltage from the drive power source 58 is not applied between the electrodes 54 and 56 (see FIG. 5(E)),
The whole is observed to be cloudy (see FIG. 7(A)). However, when the voltage of the drive power source 46 is applied and increased (see FIG. 5(D)), the pattern portion 52 becomes transparent as a whole.
A has lower transparency, so a pattern appears (7th
(See figure (D)). When the voltage is further increased, the entire cell becomes transparent and the pattern disappears (see FIG. 7(C)).

y-Experimental Example 1 In the cell of Experimental Example 6, the temperature for polymerization and curing in the second stage was set at 25° C., which was higher than that in the first stage. At this time, the change in light transmittance of the non-patterned portion 52B with respect to the applied voltage was as shown by graph LF in FIG.

Therefore, in this experimental example, when the voltage is increased from a cloudy state with a low applied voltage (see FIG. 7(A)), the pattern portion 52A first becomes transparent, and an inverted image is observed (see FIG. 7(A)).
See B). When the voltage is further increased, the entire film becomes transparent (see (C) in the same figure).

As described above, according to this second embodiment, the above-mentioned first
In addition to the effects of the embodiment, there are also the following effects. That is, there are two states in which no pattern is displayed: completely white and completely transparent, and in addition to these, there is also a pattern display state.

Therefore, it is possible to create a display that is layer-effective and rich in taste.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. 8 to 9. In this example, conditions are set such that the liquid crystal grain size in the non-patterned portion is smaller than that in the patterned portion. For example, as a polymerization initiator, a combination of an ultraviolet polymerization initiator and a thermal polymerization initiator is used. In the first stage of polymerization, patterned ultraviolet rays are irradiated at a temperature lower than the decomposition temperature of the thermal polymerization initiator. Alternatively, different intensities of ultraviolet irradiation are performed in each of the first and second polymerization stages.

l- Experimental father-in-law: BDH's E-9 as the liquid crystal and 2- as the monomer.
6. Ethylhexyl acrylate and NαCL-50 (trade name KAYARAD, manufactured by Nippon Kayaku ■) as an oligomer.
They were mixed at a weight ratio of 0:1.6:2.4, and 2% by weight each of Darocurl 173 and 2% by weight of benzoyl peroxide as a thermal polymerization initiator were added as an ultraviolet polymerization initiator and a mixed solution, respectively. This was made using a ceramic ball as a spacer and a transparent electrode with a gap of 10 μm.
It was injected into a cell with a sheet of glass substrate.

Then, as the first stage polymerization process, patterned ultraviolet rays were irradiated at room temperature for 20 seconds. The intensity of ultraviolet rays at this time was 1.5 mW/cm2. As a result, the pattern portion 60A becomes cloudy when observed.

Next, as a second stage polymerization process, the cell was placed in an appropriate heating means and heated at 100° C. for 1 minute.

As a result, the non-pattern portion 60B was polymerized and cured. In the liquid crystal composite 60 thus obtained, as shown in FIG. 8, it is thought that the liquid crystal droplets MH in the non-patterned part 60B have a smaller particle size IJX than the liquid crystal droplets MG in the patterned part 60A. In this whole cell, jI in the transparent background
The pattern portion written in the first step appeared cloudy.

The light transmittance of the pattern section 60A was as low as about 5% (
(See Figure 3(A)).

When the temperature of such a cell is gradually increased, the pattern portion 6
0A gradually became transparent, and eventually became completely transparent.

When the temperature was lowered, the pattern portion 60A became cloudy again. This phenomenon was observed over and over again.

On the other hand, a similar phenomenon occurs when a voltage is applied as in the above-described embodiment, and as the voltage increases, the pattern portion 60A becomes transparent and disappears.

U Takumi ■ The above E-9 as the liquid crystal, 2-ethylhexyl acrylate as the monomer, and bifunctional polyester acrylate as the oligomer, liquid crystal: oligomer: monomer = 70:1
While mixing at a weight ratio of 8:12, 3% by weight of a polymerization initiator Darocurl 173 was further added to prepare a mixed solution. This was similarly injected into a cell made of a 10 μm thick glass substrate with a transparent electrode.

Then, as shown by the arrow in FIG. 9(A), patterned ultraviolet rays were irradiated using a light shielding mask 36 as a first stage polymerization process. The UV intensity at this time is 1.5mW/c
m2, and the irradiation time is 20 to 30 seconds. As a result, the pattern portion 62A becomes cloudy when observed, similar to the case described above.

Next, as a second stage polymerization process, the light-shielding mask 36 was removed and ultraviolet rays were irradiated at a weaker intensity than in the previous process, as shown by the arrow in FIG. 2(B). As a result, the light transmittance of the non-patterned portion 62B was higher than that of the patterned portion 62A where polymerization was performed in the first stage.

In the liquid crystal composite 62 thus obtained, as shown in FIG. 6B, it is thought that the liquid crystal droplets MJ in the non-patterned portion 62B have a smaller particle size than the liquid crystal droplets M in the patterned portion 62A. Looking at this cell as a whole, the pattern written in the first ffra was observed as a dark cloudy state in a background that was cloudy but relatively transparent. In this example as well, the recorded pattern can be displayed and erased depending on whether or not an electric field is applied, and the same effects as in the above-mentioned embodiment can be obtained.

Fourth Embodiment Next, a fourth embodiment of the present invention will be described with reference to FIG. In this example, the particle size of the liquid crystal droplets is approximately the same in both the patterned portion and the non-patterned portion. Also, the pattern is written as a boundary line of the light-blocking mask.

The mixed solution of liquid crystal and polymer material used was the same as in Experimental Example 9 described above. Furthermore, the polymerization process in the first stage was also the same as in Experimental Example 9, as shown in FIG. Then, as a second stage polymerization process, the light-shielding mask 36 was removed and ultraviolet rays were irradiated with the same intensity as the previous time, as indicated by the arrow in FIG.

Then, the non-patterned area 7 covered with the light-shielding mask 36
In 0B, a polymerization reaction occurs similarly to the pattern portion 70A where the first stage of ultraviolet irradiation was performed, and liquid crystal droplets MK are generated. The particle size of this liquid crystal droplet MK is determined by the pattern portion 7.
It is almost the same as the 0A liquid crystal droplet MI. Therefore, there is no difference in transmittance between the patterned portion 70A and the non-patterned portion 70B of the liquid crystal composite film 70, but the boundary line portion (edge)
was observed.

The reason why the edges of the pattern are written in this way is considered to be as follows. First, the light shielding mask 36
The ultraviolet rays do not directly shine near the edges of the non-patterned portion 70B covered with. However, a polymerization reaction occurs due to a chain reaction of polymerization in the pattern portion 70A that is irradiated with ultraviolet rays. Since this polymerization reaction is different between the patterned portion 70A and the non-patterned portion 70B, edge writing is performed as a result.

Therefore, if the non-patterned portions 70B are sufficiently smaller than the patterned portions 70A, there is no need to perform the second stage of ultraviolet irradiation, and the pattern can be written only by the first stage of ultraviolet irradiation. In addition, the second stage of ultraviolet irradiation,
The ultraviolet light intensity may be different from that of the first stage.

As explained in each of the above embodiments, the liquid crystal particle size can be controlled by the curing temperature and the intensity of ultraviolet light during curing, and patterns can be written without applying an electric field. Then, if a pattern is displayed and erased under appropriate driving conditions, it functions as an optical modulator.

Other Embodiments The present invention is not limited to the above-mentioned embodiments, and various design changes are possible, including, for example, the following.

(1) The dielectric anisotropy of the liquid crystal may be either positive or negative.

(2) As is well known, since liquid crystals do not emit light by themselves, it is necessary to irradiate them with some form of illumination light from the outside. The modulator of the present invention may be of a transmissive type or a reflective type. In particular, when the cell is configured as a reflective type, one support or electrode of the cell may be formed as a mirror. Further, depending on the relationship with the light source, a filter of any color may be formed integrally with the support or the like to serve as display means for a predetermined color.

(3) In addition to the above-mentioned cell configuration, the first
Some are shown in Figure 1. In the cell shown in FIG. 3A, no support, electrodes, etc. are provided for the polymer liquid crystal composite 80. The cell shown in FIG. 2B has a support 82 only on one side of the polymer liquid crystal composite 80. The cell shown in FIG. 2C has a support 84, 86 and electrodes 88 and 90 on both sides of the polymer liquid crystal composite 80, respectively.

The cell shown in Figure (D) has a support 92 and an electrode 94 on one side.
, and the other side only has an electrode 96.

(4) FIG. 12 shows an example of a display device using the above embodiment. Polymer liquid crystal composite 100
is formed such that, for example, the particle size of the liquid crystal is different between the patterned portion and the non-patterned portion. In the illustrated example, a pattern section 102 consisting of the alphabet rABCJ and pattern sections 104 and 106 consisting of square figures are formed, respectively.

One electrode 108 is provided in common to all pattern parts, and the other electrodes 110, 112 and 114 are formed for each pattern part. Here, the electrode 110,
When a similar voltage is applied to 112 and 114, pattern parts 102, 104 and 106 are displayed simultaneously,
It may be erased.

In this case, the pattern portions 102, 104° 106
By changing the formation conditions, it is possible to display a pattern in which one pattern is displayed and the other pattern is not displayed even if the applied voltage is the same. In addition, the electrode electrode 110
, 112, and 114, similar display can be achieved even if different driving voltages are applied to them.

According to the conventional method, it was necessary to form electrodes according to the pattern, but according to the present invention, the shape of the electrode does not necessarily have to match the pattern, and the characteristics of the polymer liquid crystal composite, the electrode By combining various shapes and pattern shapes, extremely interesting displays can be created. Multiple layers of polymer liquid crystal composites may be stacked. Furthermore, since it can be made transparent when not displayed, it can be applied to show windows and the like.

(5) In the above embodiments, the incident light was formed into a desired pattern using a light-shielding mask, but patterned light may be irradiated using an appropriate method.

(6) In any of the above embodiments, the patterned portion and the non-patterned portion are in a front-back relationship, and there is no need for the portion to be irradiated with ultraviolet rays to be the patterned portion.

(7) In addition, the present invention is not limited to the above-mentioned experimental examples, and a device with appropriate characteristics may be manufactured using appropriate materials as necessary.

[Effects of the Invention] As explained above, according to the polymer liquid crystal composite and the method for producing the same according to the present invention, patterns can be written using phase separation changes in the liquid crystal depending on the polymerization conditions of the polymer matrix. As a result, patterns can be written easily without applying an electric field, and there is also a wide selection of materials, allowing for a wide range of product applications.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the first embodiment of the method for producing a polymer liquid crystal composite according to the present invention, FIG. 2 is a graph showing the characteristics of the first embodiment, and FIG. 3 is a pattern according to the first embodiment. FIG. 4 is an explanatory diagram showing the display effect; FIG. 4 is an explanatory diagram showing additional writing of a pattern according to the first embodiment; FIG. 5 is an explanatory diagram showing the method for manufacturing a polymer liquid crystal composite according to the second embodiment; FIG. The figure is a graph showing the characteristics of the second embodiment, FIG. 7 is an explanatory diagram showing the pattern display effect according to the second embodiment, and FIGS. 8 and 9 are explanatory diagrams showing the polymer liquid crystal composite in the third embodiment. 10 is an explanatory diagram showing a polymer liquid crystal composite in the fourth embodiment, FIG. 11 is an explanatory diagram showing another cell configuration example, and FIG.
Figure 13 is an explanatory diagram showing an example of application as a display.
The figure is an explanatory diagram showing a conventional method for manufacturing a polymer liquid crystal composite. 30.50...Mixed solution, 32,34,82°84.
86, 92... Support, 36... Light shielding mask, 40
．． 52, 60, 62, 70, 80... Polymer liquid crystal composite, 40A, 40G, 52A, 60A, 62A, 70A
...pattern part (first area), 40B, 52B,
60B, 62B, 70B... Non-pattern part (second area), 42, 44, 54, 56° 88.90, 94.9
6... Electrode, 46.58... Drive power supply, MA...
Polymer, MB...liquid crystal molecule, MC. MD, ME, MF, MG, MH, MI, MJ, MK...
・Liquid crystal droplets.

Claims (8)

[Claims] (1) A polymer liquid crystal composite in which liquid crystal is held in a polymer matrix through a polymerization reaction is formed by photopolymerization at a first temperature by irradiation with light in a desired pattern, and the liquid crystal undergoes phase separation. 1. A polymer liquid crystal composite comprising: a first region existing at a second temperature; and a second region formed adjacent to the first region by photopolymerization at a second temperature. (2) In a polymer liquid crystal composite in which liquid crystal is held in a polymer matrix by a polymerization reaction, photopolymerization is performed at a first temperature by irradiation with light in a desired pattern, and the liquid crystal has a first particle size. A first region exists in phase separation at a second temperature, and a liquid crystal is formed adjacent to the first region by polymerization by light or heat at a second temperature, and liquid crystal exists in a phase separation at a second particle size. 1. A polymer liquid crystal composite comprising a second region. (3) In a polymer liquid crystal composite in which liquid crystal is held in a polymer matrix through a polymerization reaction, photopolymerization is performed at a first intensity by light irradiation in a desired pattern, and the liquid crystal is formed at a first intensity. A first region that exists as a phase-separated layer depending on the particle size, and a liquid crystal that is formed adjacent to the first region by photopolymerization at a second intensity, and that the liquid crystal exists as a phase-separated layer on a second particle size. Second
A polymer liquid crystal composite comprising a region of. (4) In a polymer liquid crystal composite in which a liquid crystal is held in a polymer matrix through a polymerization reaction, a region is formed by photopolymerization by irradiation with light in a desired pattern, and where the liquid crystal exists in a phase-separated manner. , and an edge portion formed by a polymerization reaction occurring in conjunction with the polymerization of this region. (5) In a method for producing a polymer liquid crystal composite in which a liquid crystal is held in a polymer matrix by performing a polymerization reaction on a mixed solution of a liquid crystal and a photocurable resin, the first temperature is increased by irradiating light in a desired pattern. A first process in which liquid crystal is phase-separated in a polymer matrix by photopolymerization at a temperature, and a second process in which photopolymerization is carried out at a second temperature by uniform light irradiation. A method for producing a polymer liquid crystal composite. (6) In a method for producing a polymer liquid crystal composite in which a liquid crystal is held in a polymer matrix by performing a polymerization reaction on a mixed solution of liquid crystal and a photocurable resin, the first temperature is increased by irradiating light in a desired pattern. A first process of photopolymerization is carried out to phase separate the liquid crystal at a first particle size in a polymer matrix, and a photo- or thermal polymerization is carried out at a second temperature by uniform light irradiation to form a high-quality liquid crystal. A method for producing a polymer liquid crystal composite comprising a second step of phase-separating a liquid crystal with a second particle size in a molecular matrix. (7) A method for producing a polymer liquid crystal composite in which a liquid crystal is held in a polymer matrix by performing a polymerization reaction on a mixed solution of a liquid crystal and a photocurable resin.
A first process in which the liquid crystal is phase-separated in the polymer matrix at a first particle size by photopolymerization by light irradiation with an intensity of , a second step of phase-separating a liquid crystal with a second particle size in a polymer matrix. (8) In a method for producing a polymer liquid crystal composite in which a liquid crystal is held in a polymer matrix by performing a polymerization reaction on a mixed solution of a liquid crystal and a photocurable resin, photopolymerization is performed by irradiating light in a desired pattern. A polymer-liquid crystal composite comprising a first step of phase-separating a liquid crystal in a polymer matrix, and a second step of causing a polymerization reaction in chain with the polymerization in the first step. How the body is manufactured.