JP2000147235A - Production of multicolor reflecting plate and multicolor reflecting plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a clear multicolor light display with good visibility and to facilitate the increase of area and mass production by repeatedly exposing a non-fluid layer to an active material plural times to control the effective component content of an optically active group. SOLUTION: A non-fluid layer is repeatedly exposed to an active material plural times to control the effective component content of an optically active group. Excessive active material and treatment time can be eliminated, the mixing of the active material with a liquid crystal polymer is made unnecessary and restrictions on compatibility with the liquid crystal polymer and solubility to a solvent are removed. Irradiation with active light is made unnecessary and the harmful effects of the irradiation and mixing with the active material on the aligning property of the liquid crystal polymer and the damage of the polymer are inhibited. A change in the effective component content of the optically active group also shows a variation in the structure of the optically active group by which selectively reflected waves are shifted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor reflector made of a liquid crystal polymer suitable for color display of a reflection type liquid crystal display device and a method of manufacturing the same.

[0002]

2. Description of the Related Art A reflection type liquid crystal display device has a great feature that a backlight is not required as compared with a transmission type liquid crystal display device. Therefore, the display device can be made thinner and lighter. The power consumption required for the light can be reduced. Such a feature has a great value as a portable device having a liquid crystal display device and a limited capacity of a power supply, particularly a display device of a portable notebook personal computer.

In this reflection type liquid crystal display device, it is required to achieve color display in accordance with the transmission type liquid crystal device. Up to now, colorization using a color filter used in the transmission type liquid crystal display device has been required. Technology was used. However, since such a color reflection type liquid crystal display device has a dark display and poor visibility, a separate colorization technology is required.

[0004] As a new color technology for such a reflection type liquid crystal display device, a technology utilizing color change (ECB mode) due to birefringence of liquid crystal has been proposed. However, the display colors and the number of the colors are limited, resulting in poor multicolor color properties, and poor color purity and poor sharpness.

[0005] On the other hand, there has been proposed a coloring technique utilizing selective reflection by a liquid cholesteric liquid crystal having a low molecular weight (J. Phys. D: Appl. Phys., Vo.
l. 8, 1441; 1975). However, since liquid crystal is used, it must be sandwiched between glass substrates and the like, which makes it heavy and thick, which is unsuitable for a reflection type liquid crystal display device, and the liquid crystal has a fixed liquidity due to its liquidity. However, there is a problem that the color characteristics are easily changed by heat.

On the other hand, there has been proposed a film obtained by dissolving a lyotropic liquid crystal polymer in a monomer and polymerizing and fixing the same using actinic rays under temperature control (JP-A-59-83113). However, in this technology, it is necessary to perform color control by temperature, and it is necessary that the liquid crystal polymer has a substrate sandwiching structure at the time of film formation for lyotropic properties. It is difficult to reduce the size of a color section such as a blue region, and it is also difficult to increase the area and mass production.

Further, there has been proposed a technique in which a photoacid generator is added to a conventional Schiff base-containing cholesteric liquid crystal polymer, and the content of an optically active group is controlled by irradiation with actinic rays such as ultraviolet rays. However, in the irradiation of actinic rays for performing color control, it is necessary to expose a very large amount of actinic rays in order to perform sufficient multicoloring for application to a multicolor reflector, which requires energy cost. In addition, such a large amount of exposure often damages the cholesteric liquid crystal polymer itself, which is not preferable in terms of mass production and quality.

[0008]

SUMMARY OF THE INVENTION The present invention provides an easy-to-control display color and the number of colors, excellent color purity, and a bright and multi-color display in a reflection-type liquid crystal display device that is bright and has good visibility. It is possible to achieve efficient production of optical elements that are light and thin, have excellent fixation of color sections, are hard to change color characteristics at practical temperatures, can easily be enlarged, and can be easily mass-produced. The purpose is to:

[0009]

According to the present invention, a cholesteric liquid crystal polymer, which is a copolymer containing an optically active group-containing monomer as one component, is formed with a Grandian orientation, and the content of the effective component of the optically active group is reduced. A method for producing a multicolor reflector having a non-fluid layer in which a reflection region having a different reflection wavelength is formed based on the difference, comprising a step of repeatedly exposing the non-fluid layer to an active substance a plurality of times. The present invention relates to a method for producing a multicolor reflector, wherein the content of the active ingredient of the optically active group is controlled, and a multicolor reflector produced by the method.

[Effect of the Invention] By exposing the cholesteric liquid crystal polymer to the active substance in a plurality of times, it is possible to save excessive active substance and processing time, and it is not necessary to mix the active substance with the liquid crystal polymer. There is no restriction on compatibility with the liquid crystal polymer or solubility in the solvent when using a solvent, and there is no need to irradiate with actinic rays as before, so the energy required for this can be saved,
In addition to this, it is possible to suppress adverse effects on the orientation of the liquid crystal polymer and damage to the liquid crystal polymer itself due to irradiation with actinic rays or mixing of the active substance. Also, it is possible to avoid the necessity of being sandwiched between substrates, so that it is excellent in lightness and thinness, and it is excellent in fixation of color division, color characteristics are hard to change at practical temperature, and large area multicolor reflectors are easy. Can be mass-produced. In addition, the formation of regions with different reflection wavelengths depending on the number of optically active groups based on the monomer components facilitates finer color divisions, easier control of display colors and the number of colors, and is excellent in color purity and vivid and rich. It is possible to obtain a bright, high-visibility, high-efficiency, high-quality reflective liquid crystal display device of various multicolors.

The change in the content of the active ingredient of the optically active group referred to in the present invention is not only a change in the calculated content but also the effect of shifting the selective reflection wavelength due to a change in the structure of the optically active group. This includes cases where it can be obtained.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a cholesteric liquid crystal polymer having an optically active group-containing monomer component in the form of a copolymer with a nematic liquid crystal monomer, that is, an optically active group-containing monomer component Of natural light incident parallel to the helical axis of the Grandian orientation, reflects about half of light of a specific wavelength as right (or left) circularly polarized light, and the remaining Those exhibiting a characteristic of transmitting about half as left (or right) circularly polarized light can be used without particular limitation.

The wavelength λ is determined by the formula: λ = n · p (where n is the average refractive index of the liquid crystal and p is the helical pitch of the cholesteric phase). The left and right sides of the reflected circularly polarized light are
It is determined by the spiral state of the cholesteric phase, and coincides with the spiral turning direction.

Incidentally, as the nematic liquid crystal monomer, a compound represented by the following general formula [Formula 1] is exemplified.

[0015]

Embedded image Here, R ¹ is hydrogen or a methyl group, m is an integer of 1 to 6, X ¹ is an ester bond (COO group or OCO group), p and q are 1 or 2, and p + q = 3.

On the other hand, the optically active group-containing monomers include:
Examples thereof include those represented by the following general formula [Chemical Formula 2].

[0017]

Embedded image Here, R ² is hydrogen or a methyl group, n is an integer of 1 to 6, and X ² is an ester bond. R ³ is a substituent selected from seven types of substituents represented by the following [Chemical Formula 3].

[0018]

Embedded image Here, R ⁴ in Chemical Formula 3 is selected from the four substituents represented by Chemical Formula 4, and R ⁵ is a methyl group, a phenyl group,
A methoxycarbonyl group; R ⁶ is a methyl group;
It is a substituent selected from a benzyl group and a t-butyl group.

[0019]

Embedded image The acrylic monomers represented by the general formulas [Formula 1] and [Formula 2] can be synthesized by a known method. As a specific example, a synthetic example of the acrylic monomer represented by the formula (a1) is shown in the following [Chemical Formula 5].

[0020]

Embedded image The reaction shown in the above [Formula 5] will be described. First, ethylene chlorohydrin and 4-hydroxybenzoic acid are heated and refluxed in an aqueous alkali solution using potassium iodide as a catalyst to obtain a hydroxycarboxylic acid, and then the hydroxycarboxylic acid is dehydrated with acrylic acid or methacrylic acid. (Meth) acrylate, and the (meth) acrylate is converted to 4-cyano-4′-hydroxybiphenyl with D
CC (dicyclohexylcarbodiimide) and DMAP
The desired product (a1) can be obtained by esterification in the presence of (dimethylaminopyridine).

A specific synthetic example of the acrylic monomer represented by the formula (b1) is shown in the following [Chemical Formula 6].

[0022]

Embedded image The reaction shown in the above [Formula 6] will be described. First, hydroxyalkyl halide and 4-hydroxybenzoic acid,
After heating and refluxing in an alkaline aqueous solution using potassium iodide as a catalyst to obtain a hydroxycarboxylic acid, the hydroxycarboxylic acid is dehydrated with acrylic acid or methacrylic acid to give a (meth) acrylate, and the (meth) acrylate is The target compound (b1) can be obtained by esterification with a phenol having an asymmetric carbon group at the 4-position in the presence of DCC and DMAP.

The phenol having an asymmetric carbon group at the 4-position is obtained by azeotropically dehydrating 4-hydroxybenzaldehyde and (S)-(-)-1-phenylethylamine in toluene as shown in the following [Chemical Formula 7]. Can be obtained.

[0024]

Embedded image Therefore, other acrylic monomers represented by the general formulas [Chemical Formula 1] and [Chemical Formula 2] can be synthesized according to the above-mentioned method using an appropriate raw material having a target introduction group.

The copolymer can be prepared in accordance with a known acrylic monomer polymerization system such as a radical polymerization system, a cation polymerization system, or an anion polymerization system. When applying the radical polymerization method, various polymerization initiators can be used, but the decomposition temperature of azobisisobutyronitrile or benzoyl peroxide is not high,
What decomposes at an intermediate temperature which is not low (about 60 to 120 ° C.) is preferably used.

In the liquid crystal polymer (copolymer), the pitch of the cholesteric liquid crystal changes based on the content of the monomer unit having an optically active group, and the reflection wavelength is determined by the pitch. Control can adjust the color based on the reflected wavelength. The higher the content, the smaller the pitch, and the reflected light shifts to shorter wavelengths. On the other hand, if the content is excessive, the liquid crystallinity becomes poor,
If the amount is too small, cholesteric liquid crystallinity tends to be poor.

Therefore, the liquid crystal polymer which can be preferably used from the viewpoint of the above-mentioned reflection wavelength controllability, cholesteric liquid crystallinity, etc. is one or more of nematic liquid crystal monomers and one of monomers having an optically active group. Alternatively, the copolymerization ratio of the optically active group-containing monomer with two or more kinds is 50 to 3
Mol%, preferably 45-5 mol%, especially 40-
Those copolymerized so as to be 10 mol% are preferred.

The copolymerization method for producing the liquid crystal polymer by polymerizing the above monomers may be any of random copolymerization, block copolymerization, graft copolymerization and the like.

The molecular weight of the liquid crystal polymer is preferably 2 k to 100 k based on the weight average molecular weight. If it is less than 2 k, the film-forming property as a non-fluidized layer becomes poor, and
If it exceeds 300, it is difficult to form a uniform alignment state because of poor alignment property as liquid crystal, particularly monodomain formation via a rubbing alignment film or the like. From the viewpoint that a stable film formability and orientation state can be obtained, it is particularly preferable to be 2.5 k to 50 k.

The liquid crystal polymer can be used alone or in combination of two or more to form a multicolor reflector.
A liquid crystal polymer having a glass transition temperature of 80 ° C. or higher is preferably used from the viewpoint of the durability of the obtained multicolor reflector, the stability of the orientation characteristics such as pitch to temperature change in practical use, and the invariability. .

The formation of a non-fluidized layer of liquid crystal polymer having a Grandian orientation can be performed by a method according to a conventional alignment treatment. As a specific example, an alignment film made of polyimide, polyvinyl alcohol, or the like is formed on a substrate, rubbed with a rayon cloth or the like, and then a liquid crystal polymer is spread thereon, and the glass transition temperature or more. A method in which the liquid crystal polymer molecules are heated to a temperature lower than the phase transition temperature, cooled to a temperature lower than the glass transition temperature in a state in which the liquid crystal polymer molecules are in a Grandian orientation, and brought into a glassy state to form a solidified layer in which the orientation is fixed is used. From the viewpoint of processing efficiency, it is preferable to perform the alignment treatment by heating to a temperature 30 to 70 ° C., particularly about 50 ° C. higher than the glass transition temperature.

As the substrate, for example, a film made of a resin such as triacetyl cellulose, polyvinyl alcohol, polyimide, polyarylate, polyester, polycarbonate, polysulfone, polyether sulfone, or epoxy resin, or a glass plate or the like may be used. Is used. The non-fluid layer of liquid crystal polymer formed on the substrate may be used as it is with the substrate to form a multicolor reflector, or may be peeled off from the substrate to form a multicolor reflector consisting of a film or the like. It can also be used.

The liquid crystal polymer can be developed by a heating and melting system or can be developed as a solution using a solvent. As the solvent used when developing as a solution,
For example, halogenated hydrocarbons such as methylene chloride, trichloroethylene and tetrachloroethane, ketones such as cyclohexanone, ethers such as tetrahydrofuran and dioxane, and N-methylpyrrolidone are exemplified. Alternatively, two or more kinds can be used as a mixture. The development can be performed by appropriately selecting a known coating machine such as a bar coater, a spinner, and a roll coater.

When the thickness of the non-fluid layer of the liquid crystal polymer to be formed is too small, it is difficult to exhibit selective reflection characteristics (color characteristics). Because it takes a long time,
It is preferably from 0.5 to 20 μm, particularly preferably from 1 to 10 μm. When forming the multicolor reflector, one or more additives such as a polymer other than the liquid crystal polymer, a stabilizer, an inorganic compound such as a plasticizer, an organic compound, a metal, or a compound thereof are added as necessary. Can be.

According to the method for producing a multicolor reflector of the present invention, a region having a different reflection wavelength is determined based on a difference in the effective component content of an optically active group in a non-fluidized layer obtained by developing and solidifying a liquid crystal polymer as described above. It is for forming. That is, the content of the effective optically active group that contributes to the control of the helical pitch is adjusted, and regions having different reflection wavelengths are formed due to the difference in the content.

Therefore, the formation of the multicolor reflector can be achieved by making the content of the optically active group that functions effectively different.
From the viewpoints of the fineness and mass productivity of each color area (color section), easy formation of large areas, controllability and reproducibility of color, etc., the preferred formation method is that the optically active group is exposed to the liquid crystal polymer by exposure to an active substance. This is a method in which an active substance is repeatedly exposed a plurality of times using a mask or the like in which a predetermined coloration pattern is formed using a substance that denatures or deactivates.

In the above description, the denaturation or deactivation of an optically active group means that the optically active group is effectively formed into a helical pitch in a Grandian orientation due to cleavage of a bonding group of the optically active group, structural change, isomerization or rearrangement. It means that it is in a state that does not contribute. Therefore, the active substance referred to in the present invention means a substance which can modify or deactivate the binding group of the optically active group,
Specifically, for example, an acidic liquid or acidic gas is used if the binding group that binds the optically active group to the liquid crystal polymer is a Schiff base.

On the other hand, examples of the liquid crystal polymer in which the linking group of the optically active group is modified or deactivated by exposure to the active substance include those obtained by copolymerizing a monomer represented by the above general formula [1] as one component. No. In that case, the Schiff base in which R ³ in the general formula [Chemical Formula 2] has a —CH ＝ N— structure can cleave the bonding group of the optically active group by exposure to an acidic liquid or gas, and this cleavage is irreversible. The state stability is excellent, and as a result, the multicolor reflector is excellent in preventing discoloration. R ³ of the general formula [Chemical formula 2] is exemplified.
All have a Schiff base, a urethane bond, and a carbonate bond.

In the above, examples of the acidic substance include inorganic acids such as hydrochloric acid and sulfuric acid, carboxylic acids and cyanic acids,
Appropriate organic acids such as sulfonic acids can be used. Among them, hydrochloric acid, carboxylic acids, and sulfonic acids are particularly preferable from the viewpoint of ease of handling and no influence on liquid crystal alignment.

Specific examples of the above carboxylic acids include:
Formic acid, acetic acid, trifluoroacetic acid, oxalic acid, benzoic acid,
Examples include toluic acid and phthalic acid, and specific examples of sulfonic acids include toluenesulfonic acid and methanesulfonic acid. Two or more of these acidic substances may be used in combination.

As a solvent for these acidic substances, those which can be easily dissolved, and those having low or insoluble in the liquid crystal polymer and the base material can be used without limitation. For example, water, methanol, ethanol, isopropyl Alcohol and the like are exemplified. Two or more of these solvents may be used in combination as needed.

As a method for performing treatment using a liquid acidic substance, known methods can be used, and examples thereof include a method of dipping in a solution and a method of spraying with a sprayer.
It is not limited to these.

When the treatment is performed with an acidic liquid, it is desirable to rinse the treated surface with the solvent used for preparing the acidic liquid or another solvent after the treatment. If the heating alignment treatment is performed while the acidic substance remains on the treated surface, the acid may crystallize due to evaporation of the solvent, or the acid may become too high in concentration, which may adversely affect the liquid crystal polymer itself or its alignment. .
Solvents that can be used for rinsing, like solvents for the preparation of acidic liquids, have a high solubility for the acidic substances used and are hardly soluble or insoluble in the liquid crystal polymer and base material used. Some are used, such as, but not limited to, water, methanol, ethanol, isopropyl alcohol, and the like. Further, the solvent may be the same as that used in the acidic liquid treatment, or may be different.

Instead of using an acidic liquid, the non-fluidized bed may be treated with an acidic gas. As the treatment method, a known method can be used, for example, a method in which an acidic gas is filled in a closed container, a method in which a liquid crystal polymer is retained and treated therein, and a method in which the liquid crystal polymer is sprayed with an injector are exemplified. It is not limited. The acidic gas can be generated by a known method. Specifically, a method of putting a high-concentration acidic liquid into a processing vessel to volatilize it, a method of synthesizing or generating an acidic gas in a separate vessel and sending it into the processing system, and a method of applying pressure and flow rate of a commercially available acidic gas in a cylinder The method of controlling and using is exemplified, but of course, the method is not limited to these.

As the above-mentioned acidic gas, any gaseous acid such as hydrogen chloride, hydrogen bromide, hydrogen sulfide and hydrogen cyanide can be used. Among them, hydrogen chloride is preferably used from the viewpoint of safety and easy handling. Can be

As described above, the acidic substance, which is an active substance suitable for the present invention, may adversely affect the liquid crystal polymer itself and its orientation if left in the non-fluidized bed. Preferably not.

The multicolor formation of the non-fluidized layer can be performed by forming regions having different reflection wavelengths based on the difference in the content of the effective component of the optically active group as described above. In such a case, in the method of exposing the acidic substance, the treatment is to reduce the effective component of the optically active group, so that the reflection light has a longer wavelength.

Therefore, for the color display of the reflection type liquid crystal display device, the reflection region is preferably composed of a red region, a green region, and a blue region (RGB), and these reflection regions are formed regularly. Is preferred. In the case of forming such a multicolor reflector, it is necessary to use a liquid crystal polymer having a reflection wavelength of blue or less as a base and to perform a wavelength-extending treatment with an active substance so as to have a predetermined coloration pattern. There is.

The number of colors in the multicolor reflector can be set to an appropriate number of two or more colors in accordance with the purpose of use, and the color arrangement pattern and the size of the color section are also appropriately determined in accordance with the purpose of use. be able to. Incidentally, RGB reflection plates suitable for a reflection type liquid crystal display device generally have an arrangement pattern such as a triangle shape, a stripe shape, a lattice shape, and a checkered shape. In addition, when the active substance is exposed, the size of the color section can be on the order of several microns by precisely controlling the amount of exposure through a mask or the like. In the active substance exposure method described above, the non-fluidized layer to be exposed may not be subjected to the orientation treatment.However, from the viewpoint of the coloring accuracy due to the reproducibility of the orientation, the orientation treatment is performed in advance. It is preferable to subject the non-fluidized layer exhibiting monochromatic reflection to an exposure treatment for multicoloring.

The predetermined color scheme in the non-fluidized bed that has been subjected to the above-mentioned multicoloring treatment can be developed by performing the above-described heating alignment treatment. If the state before the heat alignment treatment, that is, the state after the multicoloring treatment is finished, the desired color scheme does not appear, and the state before the multicoloring treatment is maintained. The heating orientation treatment can be performed simultaneously with the exposure treatment for multicoloring, but it is more desirable to perform the heating orientation treatment after the irradiation treatment in terms of complicating the apparatus and reducing safety.

In order to efficiently perform the above-described multicoloring treatment with a small amount of exposure, it is preferable to alternately repeat the multicoloring treatment and the heating alignment treatment. The number of repetitions and the amount of exposure of the active substance per one time vary depending on the kind of the binding group of the optically active group, the kind of the active substance, the concentration, the dissociation constant, etc. Exposure amount of active substance per room temperature is, for example, 50
00 seconds or less are preferable. If the frequency / exposure is too small,
It is not preferable because sufficient multicoloring cannot be obtained. On the other hand, if the number of times and the amount of exposure are excessive, the alignment property and the liquid crystal polymer itself are adversely affected, which is not preferable.

As described above, including a multicoloring process generally performed using a photoacid generator or the like, a liquid crystal polymer exhibiting selective reflection of blue or less is used as a base, and the number of processes is one. In order to obtain sufficient multicolor, an extremely large amount of exposure to the active substance is required, and under such conditions, the alignment of the liquid crystal polymer and the liquid crystal polymer itself are adversely affected. Even if the number of steps of repeating the multicoloring treatment-heating alignment treatment is increased as in the production method of the present invention, it is still shorter in time than the conventional method, high efficiency with a small amount of energy,
In addition, it is extremely advantageous in terms of maintaining the alignment state.

In the manufacturing method of the present invention, for example, an RGB reflector preferably used for a liquid crystal display device uses a liquid crystal polymer having a reflection wavelength of blue or less as a base and first passes green and red through an appropriate mask. After performing the multi-coloring process as much as the area to be shown indicates the reflection wavelength of green, and after performing the heat alignment treatment, only the area that should show red again will shift the reflection wavelength from green to red again. By carrying out the heat treatment and the heat alignment treatment, the desired RGB reflector can be obtained in a short time with high quality.

The multicolor reflector obtained by the production method of the present invention can be used for various purposes as a multicolor reflector, and is particularly excellent in the accuracy and fineness of a color section formed of a coloration pattern such as RGB. Since these can be easily obtained, they can be preferably used for multicolor display of a reflection type liquid crystal display device.

[0055]

Embodiments of the present invention will be described below.

Example 1 A monomer (a2) represented by Chemical Formula 8 was used as a nematic liquid crystal monomer in an amount of 75 mol%, and a monomer (b2) represented by Chemical Formula 9 was used as a monomer containing an optically active group. The weight average molecular weight of the copolymer of 25 mol% is 7000, and the glass transition temperature is 80.
The cholesteric liquid crystal polymer having a cholesteric structure at a temperature between 270 ° C. and an isotropic phase transition temperature of 270 ° C. was used.

[0057]

Embedded image

Embedded image This side chain type cholesteric liquid crystal polymer was dissolved 3
A 0% by weight cyclohexanone solution is coated on a 50 μm-thick triacetyl cellulose film on a polyvinyl alcohol layer having a thickness of about 0.1 μm, rubbed with a rayon cloth, and coated with a spin coater.
An optical element in which a non-fluidized layer made of a liquid crystal polymer having a thickness of 2.0 μm and a central wavelength of reflected light of 440 nm is integrated with a triacetylcellulose film, while being heated and orientated at 60 ° C. for 5 minutes and allowed to cool at room temperature. I got Next, in the non-fluidized layer of the optical element, a transmission region and a non-transmission region
Using a mask arranged in a stripe pattern at a pitch of 200 μm and 200 μm, the substrate was held for 600 seconds in a sealable container saturated with hydrogen chloride at room temperature, exposed, and then exposed for 16 seconds.
It was heated and aligned at 0 ° C. for 5 minutes and allowed to cool at room temperature. Again, apply hydrogen chloride to the same position through the same mask for 60 times.
Exposure was performed for 0 second, the mask was moved 100 μm in the direction perpendicular to the stripe pattern, and then exposed to hydrogen chloride for 600 seconds. Are 610 nm and 540 nm
And a multicolor reflector having three regions of 440 nm in a striped arrangement at a pitch of 100 μm. The reflection spectrum of the obtained multicolor reflector is shown in FIG.

[Example 2]

Embedded image 82% by mole of the monomer (a2) represented by the chemical formula [Chemical Formula 8], which is obtained by using the monomer represented by the chemical formula [Chemical Formula 10] instead of the monomer represented by the chemical formula [Chemical Formula 9], 10] A side-chain cholesteric liquid crystal polymer having a weight average molecular weight of 8000, a glass transition temperature of 85 ° C., and an isotropic phase transition temperature of 280 ° C., comprising a copolymer of 18 mol% of the monomer (b3) represented by 10) was dissolved. The center wavelength of the reflected light was 610 nm and 54 nm in accordance with Example 1, except that a non-fluidized layer was formed using a 20% by weight tetrachloroethane solution.
A multicolor reflector having three regions of 0 nm and 440 nm at a predetermined pitch was obtained. The reflection spectrum of the obtained multicolor reflector is shown in FIG.

Example 3 A saturated aqueous solution of p-tosylic acid was used as an active substance, which was dipped for 700 seconds each time and rinsed with water. Wavelengths of 610 nm, 540 nm and 440
A multicolor reflector having three regions of nm at a predetermined pitch was obtained. The reflection spectrum of the obtained multicolor reflector is shown in FIG.
It was shown to.

COMPARATIVE EXAMPLE 1 A transmission region and an opaque region were exposed for 600 seconds through a mask formed in a stripe pattern at a pitch of 200 μm and 100 μm, respectively, and the mask was exposed at 100 μm in the transmission region and 200 μm in the opaque region. In place of the above, half of the previously exposed area was further exposed for 3000 seconds, and then the center wavelength of the reflected light was 580 nm, 500 nm, and 440 n according to Example 1 except that the alignment was performed by heating.
Thus, a multicolor reflector having three regions consisting of m at a predetermined pitch and having poor orientation was obtained. The reflection spectrum of the obtained multicolor reflector is shown in FIG. Comparing these four kinds of reflection spectra, it is clear that the production method of the present invention is excellent and that a good multicolor reflector can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a reflection spectrum of a multicolor reflector obtained in Example 1.

FIG. 2 is a diagram showing a reflection spectrum of a multicolor reflector obtained in Example 2.

FIG. 3 is a view showing a reflection spectrum of a multicolor reflector obtained in Example 3.

FIG. 4 is a diagram showing a reflection spectrum of a multicolor reflector obtained in Comparative Example 1.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kyoko Izumi 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Shu Mochizuki 1-1-2 Shimohozumi, Ibaraki-shi, Osaka F-term in Nitto Denko Corporation (reference) 2H048 BA04 BA64 BB02 BB15 BB42 2K009 AA00 BB28 CC21 DD02 DD06 DD12

Claims (6)

[Claims] 1. A cholesteric liquid crystal polymer containing a monomer containing an optically active group as one component is formed by Grand Jean alignment, and reflection regions having different reflection wavelengths are formed based on the difference in the content of the effective component of the optically active group. A method for producing a multicolor reflector having a non-fluidized layer, comprising a step of controlling the effective component content of the optically active group by repeatedly exposing the non-fluidized layer to an active substance a plurality of times. Method for producing a multicolor reflector. 2. The method according to claim 1, wherein the optically active group-containing monomer has at least one of a Schiff base, a urethane bond, and a carbonate bond. 3. The method according to claim 1, wherein the active substance is an acidic liquid or an acidic gas. 4. The method according to claim 1, wherein a step of mixing the active substance into the liquid crystal polymer in advance is not provided.
The method for producing a multicolor reflector according to any one of the above. 5. The reflection region according to claim 1, wherein the reflection region is a red reflection region, a green reflection region, and a blue reflection region, and these reflection regions are formed regularly. A method for manufacturing a multicolor reflector. 6. A multicolor reflector produced by the method according to claim 1.