KR20130041718A - Method for fabricating colesteric liquid crystal display - Google Patents

Abstract

PURPOSE: A manufacturing method of a cholesteric liquid crystal display is provided to implement RGB sub-pixel which a selection reflection wavelength is different, thereby increasing manufacturing costs and manufacturing efficiency. CONSTITUTION: Liquid crystal composition(3) is injected into a plurality of cell spaces surrounded by a partition wall(2) and a substrate(1). An ultraviolet ray is irradiated to the cell spaces through a photo mask(4) in temperature which is higher than room temperature. A blue sub-pixel(5) is formed in an area corresponding to a blocking unit of a half tone mask which blocks the ultraviolet ray. A green sub-pixel(6) is formed in an area corresponding to a half tone transmission unit of the half tone mask which blocks a part of the ultraviolet ray. A red sub-pixel(7) is formed in an area corresponding to a transmission unit of the half tone mask which transmits the ultraviolet ray.

Description

Manufacturing method of cholesteric liquid crystal display {METHOD FOR FABRICATING COLESTERIC LIQUID CRYSTAL DISPLAY}

The present invention relates to a method for producing a cholesteric liquid crystal display used for color electronic paper and the like.

In general, cholesteric liquid crystals are organic by adding chiral agents to nematic liquid crystals and have a spiral structure of a certain period. The cholesteric liquid crystal in a planar state in which the spiral axis is perpendicular to the substrate reflects circularly polarized light components that coincide with the twisted direction of the spiral among light incident in parallel to the spiral axis, and generates circularly polarized light components in different directions. It has selective reflective properties to transmit. The central wavelength λ and the wavelength band width Δλ of the reflected light showing the selective reflection characteristics are represented by λ = n × P and Δλ = Δn × P, respectively. Where n is the average refractive index in the plane orthogonal to the spiral axis, P is the spiral pitch, and Δn is the refractive index anisotropy.

A voltage is applied to a cholesteric liquid crystal having positive dielectric anisotropy, the planar state of which the helix axis is perpendicular to the substrate, the focal conic state of which the helix axis is parallel to the substrate, and the helix are released to the most in the ellipse of the liquid crystal. The long diameter can be changed into three states of homeotropic state that coincide with the electric field direction. Selective reflection occurs in the planar state, cloudy in the focal conic state, and light is transmitted in the homeotropic state. In addition, the two states, the planar state and the focal conic state, indicate bistable stability (memory) which is maintained even after the voltage is cut off.

It is proposed to use it as a display utilizing the wavelength selective reflectivity and bistability of such a cholesteric liquid crystal (for example, refer patent document 1 and 2). In particular, the wavelength selective reflectivity of the cholesteric liquid crystal does not require a polarizing plate or a color filter. The bistable stability of the cholesteric liquid crystal enables large screens by passive matrix driving and low power consumption. Accordingly, the cholesteric liquid crystal display is suitable as a display for color electronic paper.

However, the conventional general cholesteric liquid crystal display has a liquid crystal panel 10 of blue (B), a liquid crystal panel 11 of green (G), and a red (R) liquid crystal panel 12 as shown in FIG. Because of the stacked structure, it is difficult to reduce the thickness and weight and to increase the manufacturing cost. In addition, since the chiral spiral force used in general cholesteric liquid crystals is not strong, the chiral concentration must be about tens of percent in order to obtain selective reflection in the visible light region, thereby causing a material cost increase. . Accordingly, it is preferable to solve the above problem by reducing the thickness, weight, and cost of the display, specifically, by forming sub-pixels on one panel and multicoloring them.

In Non-Patent Document 1, an RGB stripe (by forming a small cell in the form of a slit, injecting a liquid crystal of any one of RGB into a corresponding slit, and actually encapsulating it three times, once for each liquid crystal of RGB) Suggest a way to make a stripe.

In Non-Patent Document 2, after encapsulating a liquid crystal composition containing a photoreactive chiral agent, adding a binder to prepare an ink, applying the ink onto a substrate and patterning the RGB subpixels by irradiating ultraviolet rays having different irradiation amounts. I am suggesting a method.

However, in the method of Non-Patent Document 1, only the RGB arrangement in the form of a stripe can be supported, and since the cholesteric liquid crystals of each RGB need to be divided into small cells, manufacturing efficiency is not sufficient.

In the method of Non-Patent Literature 2, the Helical Twisting Power (HTP) of the photoreactive chiral agent is small. As a result, a large amount of the photoreactive chiral agent must be added to the liquid crystal composition to obtain a blue selective reflection wavelength. There is a problem that the manufacturing cost rises. In addition, when the selective reflection wavelength is changed by ultraviolet irradiation, a large amount of ultraviolet radiation needs to be irradiated, and thus there is a problem that the production efficiency is not sufficient.

Patent Document 1: Japanese Patent Application Laid-Open No. 2008-268566 Patent Document 2: Japanese Patent Application Laid-Open No. 2009-122537

[Non-Patent Document 1] Kuan-Ting Chen et al., 10, "Full Color Cholesteric Liquid Crystal Display with High Color Performance", SID 10 Digest, Pages 289-292 Non-Patent Document 2: Bum-Young Lee and four others, "Full Color Fexible Cholesteric Display on Single Substate," SID 10 Digest, pp. 286-288.

An object of the present invention is to provide a manufacturing method of a cholesteric liquid crystal display which is excellent in manufacturing cost and manufacturing efficiency, and which can be reduced in weight and thickness by solving the above problems.

The inventors have recognized that the helical organic force of the photoreactive chiral agent added to the liquid crystal composition and the temperature conditions during ultraviolet irradiation have a great influence on the manufacturing cost and manufacturing efficiency of the cholesteric liquid crystal display, and based on the helical organic It was found that the above-mentioned conventional problem can be solved by selecting and using a specific photoreactive chiral agent having a large force and irradiating ultraviolet rays at a temperature higher than room temperature.

That is, the manufacturing method of the cholesteric liquid crystal display of the present invention includes the steps of adding a photoreactive chiral agent represented by the following general formula (1) to the liquid crystal composition; Forming a liquid crystal cell filled with the liquid crystal composition to which the photoreactive chiral agent is added; And irradiating ultraviolet rays to the liquid crystal cell through a photomask at a temperature higher than room temperature to form a plurality of subpixels having different selective reflection wavelengths according to the irradiation amount of the ultraviolet rays.

≪ General Formula 1 &

In Formula 1, Ar is a substitutable aromatic group, R1 and R2 are substituents in which C * forms an asymmetric carbon, R3 is -CONH-, -COO-, or -C = N-, and R4 is XBA- And A is a substitutable aromatic group, B is a planar conjugated group, and X is a residual group including a substitutable aromatic group.

The ultraviolet irradiation is carried out at a temperature of more than 25 ℃ 150 ℃.

The photoreactive chiral agent is represented by the following formula (1).

≪ Formula 1 >

The photo mask is a halftone mask.

The irradiated ultraviolet rays have a peak wavelength of 250 ~ 300 nm.

A blue subpixel that reflects a blue wavelength is formed in a region corresponding to the blocking portion of the halftone mask that blocks the irradiated ultraviolet rays, and corresponds to the halftone transmission portion of the halftone mask that blocks a portion of the irradiated ultraviolet rays. A green subpixel reflecting a green wavelength is formed in a region, and a red subpixel reflecting a red wavelength is formed in a region corresponding to a transmission portion of the halftone mask that transmits the irradiated ultraviolet rays.

The photoreactive chiral agent is added to the liquid crystal composition in an added amount such that the selective reflection wavelength of the liquid crystal composition maintains a wavelength below the blue wavelength region. That is, the addition amount of the said photoreactive chiral agent is 0.1 mass% or more and less than 8 mass%.

The liquid crystal composition further includes a chiral agent having no photoreactivity until the selective reflection wavelength reaches a red wavelength region.

According to the present invention, it is possible to realize a plurality of subpixels having different selective reflection wavelengths in a short time, and thus, a manufacturing method of a cholesteric liquid crystal display suitable for color electronic paper and the like, which is excellent in manufacturing cost and manufacturing efficiency, and can be reduced in weight and thickness. Can provide.

1 is a cross-sectional view of a conventional general cholesteric liquid crystal display.
2 is a cross-sectional view for explaining a method for manufacturing a cholesteric liquid crystal display according to the present invention.
3 is a graph showing the relationship between the ultraviolet irradiation dose and the selective reflection wavelength in the liquid crystal composition prepared in the embodiment of the present invention.

In the manufacturing method of the cholesteric liquid crystal display of the present invention, a photoreactive chiral agent having a large spiral organic force is added to the liquid crystal composition and the liquid crystal composition is injected into the liquid crystal cell, and then irradiated with ultraviolet rays through a photomask at a temperature higher than room temperature. It is characterized by forming a subpixel.

Hereinafter, a preferred embodiment of the manufacturing method of the cholesteric liquid crystal display of the present invention will be described with reference to the drawings.

2 is a cross-sectional view for explaining a method for manufacturing a cholesteric liquid crystal display according to the present invention.

The photoreactive chiral agent used in the present invention is represented by the following general formula (1).

≪ General Formula 1 &

In Formula 1, Ar is a substitutable aromatic group, R1 and R2 are substituents in which C * forms an asymmetric carbon, R3 is -CONH-, -COO-, or -C = N-, and R4 is XBA And A is a substitutable aromatic group, B is a planar conjugated group and X is a residual group including a substitutable aromatic group.

In Ar, A, and X, a substitutable aromatic group is not particularly limited, but a benzene ring such as a phenyl group; Condensed rings such as a naphthyl group, anthryl group, and phenanthryl; Residual groups of heteroaromatic rings; And such substituents may be used. Although it does not specifically limit as a substituent, A methyl group etc. can be used.

R1 and R2 are not particularly limited as long as C * is a substituent forming an asymmetric carbon, but R1 and R2 are preferably different alkyl groups or hydrogen atoms. R 1 and R ₂ may be halogen-containing groups such as F, Cl, Br, CF ₃ , and CCl ₃ . Although it does not specifically limit as an alkyl group, A methyl group, an ethyl group, n-propyl group, an isopropyl group, n-butyl group, etc. can be used.

Although it does not specifically limit as B which is a plane conjugate group, -COO-, -C = C-, -CONH-, -C = N- etc. can be used.

The residual group containing an aromatic group at X may be one in which a residual group containing a further aromatic group is bonded to the bonding site with B of the aromatic group. For example, you may have a dimer structure containing the site | part of Ar-B.

Photoreactive chiral agent having the above structure can be easily synthesized by a known method in the art.

Examples of preferred photoreactive chiral agents for use in the present invention include R-(+)-4-octyloxy-benzoic acid (benzoic acid) 4-[(1-naphthalene-1 -yl) Ethylimino)-methyl]-phenyl ester, R-(+)-4-octyl-benzoic acid 4-[(1-naphthalene-1-ylethylimino)-methyl]-phenyl ester , R-(+)-4 '-octyloxycyanobiphenyl 4-carbonic acid 4-[(1 -naphthalene-1-ylethylimino)-methyl]-phenyl ester, R -(+)-4- Dodecyloxy-benzoic acid 4-[(1-naphthalene-1- ylethylimino)-methyl]-phenyl ester, R-(+)-biphenyl Carboxylic acid 4-[(1-naphthalene-1-ylethylimino) -methyl] -phenyl ester, R-(+)-4-[(1-naphthalene-1-ylethylimino) -methyl] -benzoic acid 4-[(1-naphthalene-1-ylethylimino) -methyl] -phenyl ester , R-(+)-terephthalic acid bis-{4-[(1-naphthalene-1-ylethylimino)-methyl]-phenyl} ester, R-(+)-biphenyl 4,4 '-Dicarbon acid bis (-{4-[(1-naphthalene-l-ylethylimino) -methyl] -phenyl} ester, etc. may be used. In addition, a photoreactive chiral agent may be used. Is not limited to the above examples, and it is also possible to use the additional isomer S-(-)-isomer.

Among the various photoreactive chiral agents described above, R-(+)-terephthalic acid bis-{4-[(1 -naphthalene-1-ylethylimino) having the largest helix organic force from the viewpoint of production cost and production efficiency -Methyl] -phenyl} ester is preferred. This compound is represented by the following formula (1).

The spiral organic force of the photoreactive chiral agent is preferably 60 / µm or more, more preferably 80 / µm or more, and most preferably 100 / µm or more. Here, the helix organic force is 1 / pc (p = pitch (μm), c = photoreactive chiral agent in a measuring system including 4′-hexyl oxy-4-cyano biphenyl as a liquid crystal). Corresponds to the torsion power represented by the mole fraction of.

The amount of the photoreactive chiral agent added is not particularly limited as long as the selective reflection wavelength of the liquid crystal composition is a wavelength equal to or more than a blue region, preferably less than 470 nm. Here, the blue region means a wavelength region of 450 to 495 nm.

Since the photoreactive chiral agent used by this invention has a large spiral organic force, the addition amount with respect to a liquid crystal composition can be reduced. The specific addition amount of a photoreactive chiral agent in a liquid crystal composition becomes like this. Preferably it is 0.1 mass% or more and less than 8 mass%, More preferably, it is 1-5 mass%.

The liquid crystal component in the liquid crystal composition is a nematic liquid crystal. It does not specifically limit as a nematic liquid crystal, A well-known thing in the said technical field can be used. Examples of nematic liquid crystals include biphenyl, phenyl cyclohexyl, terphenyl, tran, pyrimidine and stilbene. Known ones can be used. These may be used alone or in combination of two or more. It is preferable that a nematic liquid crystal is non-reactive with a photoreactive chiral agent, and it is preferable to show liquid crystal at normal temperature from a practical point of view. Here, normal temperature means 25 degreeC.

In the liquid crystal composition used in the present invention, a chiral agent without photoreactivity may be added together with the photoreactive chiral agent until the selective reflection wavelength reaches a red region. Here, the red region means a wavelength region of 630 to 750 nm. The chiral agent having no photoreactivity until the selective reflection wavelength reaches the red region is not particularly limited, and any known one in the art can be used. Examples of such chiral agents include MLC-6247 manufactured by Merck. The addition amount of the chiral agent without photoreactivity is not specifically limited as long as it is a range which does not impair the effect of this invention.

It does not specifically limit as a preparation method of a liquid crystal composition, What is necessary is just to implement by a well-known method. For example, by adding a photoreactive chiral agent (and a chiral agent that is not photoreactive with respect to light of a wavelength below the red region optionally) to the nematic liquid crystal, and then mixing by using a known mixing device. A liquid crystal composition can be prepared.

In the manufacturing method of the cholesteric liquid crystal display of this invention, the partition 2 between the two board | substrates 1 and the board | substrate 1 is used for the liquid crystal composition 3 manufactured as mentioned above as shown in FIG. It is injected into the liquid crystal cell consisting of). The interior of the liquid crystal cell is spaced apart by the partition wall 2, and the liquid crystal composition 3 is injected into a plurality of cell spaces surrounded by the partition wall 2 and the substrate 1. As a structure of such a liquid crystal cell, the well-known structure known in the said technical field can be employ | adopted. The method of injecting the liquid crystal composition 3 into the liquid crystal cell is not particularly limited, and the liquid crystal composition 3 is added dropwise onto any one of the two substrates 1, and then the liquid crystal composition 3 is dropped. The liquid crystal dropping method (ODF) which adheres the remaining board | substrate, or the vacuum injection method can be used.

Then, the liquid crystal composition 3 injected into the liquid crystal cell is irradiated with ultraviolet rays through the photomask 4 at a temperature higher than normal temperature as shown in FIG. 2 (B). By irradiating ultraviolet rays with different irradiation amounts under such temperature conditions, a plurality of subpixelations having different selective reflection wavelengths can be performed in a short time. As a result, it becomes possible to improve manufacturing efficiency and to reduce manufacturing cost.

Here, normal temperature means 25 degreeC. The temperature at the time of performing ultraviolet irradiation becomes like this. Preferably it is 25 degreeC exceeding 150 degreeC or less, More preferably, it is 30 degreeC-100 degreeC, Most preferably, it is 40 degreeC-60 degreeC. If the temperature at the time of ultraviolet irradiation is below room temperature, subpixelation cannot be performed in a short time, manufacturing efficiency cannot fully be improved, and manufacturing cost will also increase. If the temperature at the time of ultraviolet irradiation exceeds 150 degreeC, a chiral agent may decompose.

When ultraviolet-ray is irradiated to the liquid crystal composition 3, the photoreactive chiral agent contained in the liquid-crystal composition 3 responds according to the irradiation amount, and changes the spiral structure of a cholesteric liquid crystal. And by this structural change, the liquid crystal composition 3 has various selective reflection wavelengths. Therefore, when ultraviolet rays are irradiated through the photomask 4 so as to change the irradiation amount for each desired region, it becomes possible to form color subpixels having a plurality of selective reflection wavelengths. In particular, when a halftone photo mask is used, it is also possible to form color subpixels having a plurality of selective reflection wavelengths in one irradiation.

For example, as shown in FIG. 2C, the B subpixel in which the blue selective reflection wavelength of the initial liquid crystal composition is maintained by completely blocking the irradiation of ultraviolet rays through the blocking portion (black portion) of the halftone photo mask 4 is maintained. (5), the G subpixel 6 which gives a green selective reflection wavelength by blocking about half of ultraviolet irradiation through the halftone transmission part (gray part) of the halftone photo mask 4, and the halftone photo mask By transmitting all ultraviolet irradiation through the full transmission part (white part) of (4), the color pixel which has the R subpixel 7 which gives a red selective reflection wavelength can be formed.

The light source used for ultraviolet irradiation is not specifically limited, A well-known thing can be used. For example, a high pressure mercury lamp, a metal halide lamp, a Hg-Xe lamp, or the like may be used as the light source.

Although the ultraviolet-ray to irradiate is not specifically limited, It is preferable to have a peak wavelength in 250-300 nm from a viewpoint of practical use.

It does not specifically limit as a heating method at the time of ultraviolet irradiation, A well-known heating means can be used. For example, an oven, a hot plate, etc. can be used as this heating means.

In the present invention, since a photoreactive chiral agent having a large helical organic force is used, a desired selective reflection wavelength can be obtained with a small amount of ultraviolet radiation compared with a general optical chiral agent. As a result, it becomes possible to improve the productivity of the cholesteric liquid crystal display.

Although the irradiation intensity of ultraviolet-ray needs to be adjusted suitably according to the peak wavelength of an ultraviolet-ray, etc., it is generally 1-200 mW / cm <2>. Although the irradiation amount of ultraviolet rays also needs to be appropriately adjusted according to the target selective reflection wavelength, the peak wavelength of ultraviolet rays, and the like, it is generally 1 to 1000 mJ / cm 2.

Since the method of manufacturing the cholesteric liquid crystal display of the present invention described above can dedicate an existing exposure process, the RGB subpixels can be formed with high precision and at low cost. In addition, in the production method of the present invention, since the ultraviolet irradiation is performed at a temperature higher than the normal temperature while using a photoreactive chiral agent having a large helical organic force, the amount of addition of the photoreactive chiral agent or the irradiation amount of the ultraviolet ray can be reduced to increase productivity. And reduction of manufacturing cost can be realized. In addition, since the cholesteric liquid crystal display obtained by the manufacturing method of the present invention has a monolayer structure composed of RGB subpixels, unlike the conventional stacked structure of RGB, the display can be made thinner and lighter.

On the other hand, the manufacturing method of the present invention is Yumoto Makotomin et al., "Development of a photoreactive chiral agent for cholesteric liquid crystal for color filters for liquid crystal display", Fujifilm research report, Fuji Photo Film Co., Ltd., 17 years It is also possible to apply to manufacture of the color filter by the exposure method described on March 22, 50, 60-63.

Example

Hereinafter, examples of the present invention will be described in detail, but the present invention is not limited to the following examples.

< Photoreactive Chiralze : R-(+)-terephthalic acid Vis  -{4-[(1-naphthalene-1 Ilethylimino )- methyl ]- Phenyl } Synthesis of Ester>

10.0 mmol of terephthalic acid and 20 mmol of 4-hydroxybenzaldehyde were dissolved in 80 mL of chloroform, and 1-ethyl-3- (3-dimethylaminopropyl) -carbodiimide hydrochloride 11.0 mmol (EDCI) and catalytic amounts of N, N'-dimethylamino pyridine were added. After stirring at room temperature for one day, ethanol was added to precipitate a solid. The precipitated solid was recrystallized from ethanol to obtain an ester compound as an intermediate.

Next, 11.0 mmol of the ester compound and 20.0 mmol of R-(+)-1- (1-naphthyl) ethylamine were dissolved in a mixed solvent of 100 mL of chloroform and 50 mL of ethanol, followed by 60 ° C. It was refluxed for 5 hours. After cooling to room temperature, 80 mL of ethanol was added to precipitate a solid. The precipitated solid was recrystallized from ethanol to obtain the target compound. The spiral organic force of the obtained target compound was 141 / µm.

&Lt; Preparation of liquid crystal composition &

As a nematic liquid crystal, the mixed liquid crystal of MLC-2140 and MLC-2148 (mass ratio 51.3: 48.7, Merck Co., Ltd.) was used, the said photoreactive chiral agent was added and mixed with this mixed liquid crystal, and the liquid crystal composition was prepared. Here, the addition amount of the photoreactive chiral agent with respect to the liquid crystal composition was 4.04 mass%.

< Cholesteric  Manufacturing and Evaluation of Liquid Crystal Displays>

The first substrate on which the first indium tin oxide (ITO) electrode and the rubbed alignment layer are stacked, and the second substrate on which the photo spacer and the rubbed alignment layer having a height of 6 μm and the rubbed alignment layer are laminated, are bonded to each other. After preparing the cell, the prepared liquid crystal composition was injected into the liquid crystal cell.

The ultraviolet-ray (peak wavelength 254 nm) was irradiated to the produced liquid crystal cell at each irradiation amount at the temperature of 100 degreeC, and the selective reflection wavelength of the liquid crystal composition was measured. Here, a hot plate was used as a heating method.

In addition, after irradiating ultraviolet rays (peak wavelength 254 nm) with each irradiation amount at the temperature of 23 degreeC, the selective reflection wavelength was measured to the liquid crystal cell which injected the same liquid crystal composition as a comparative example. Here, the selective reflection wavelength was measured by the Japan dichroism (CD) dispersion meter J-720 type. The results are shown in Fig.

Referring to FIG. 3, it can be seen that the selective reflection wavelength of the liquid crystal cell changes linearly with the irradiation amount of ultraviolet rays. The Example of this invention which irradiated the ultraviolet-ray at the temperature of 100 degreeC compared with the comparative example which irradiated the ultraviolet-ray at the temperature of 23 degreeC was able to obtain desired selective reflection wavelength with a small amount of ultraviolet irradiation. That is, the embodiment of the present invention irradiated with ultraviolet rays at a temperature of 100 ° C. can perform RGB subpixelation in a shorter time, compared to the comparative example where the ultraviolet rays are irradiated at a temperature of 23 ° C., thereby providing excellent manufacturing cost and manufacturing efficiency. Can be considered.

< Cholesteric  Production of liquid crystal display>

The first substrate on which the first indium tin oxide (ITO) electrode and the rubbed alignment layer are stacked, and the second substrate on which the photo spacer and the rubbed alignment layer having a height of 6 μm and the rubbed alignment layer are laminated, are bonded to each other. After preparing the cell, the prepared liquid crystal composition was injected into the liquid crystal cell. Next, the cholester having RGB subpixels is irradiated with ultraviolet rays (peak wavelength 254 nm) at a predetermined irradiation amount through a halftone photo mask based on the relationship between the ultraviolet irradiation amount shown in FIG. 3 and the selective reflection wavelength of the liquid crystal composition. Rick liquid crystal displays could be manufactured.

As described above, in the present invention, it is possible to realize RGB subpixelation having different selective reflection wavelengths in a short time, thereby providing excellent manufacturing cost and manufacturing efficiency, and being lighter and thinner, which is suitable for color electronic paper and the like. It is possible to provide a method for producing.

1: substrate 2: partition
3: liquid crystal composition 4: photo mask
5: B subpixel 6: G subpixel
7: R subpixel 10: blue (B) liquid crystal panel
11: green (G) liquid crystal panel 12: red (R) liquid crystal panel

Claims (9)

Adding a photoreactive chiral agent represented by the following general formula (1) to the liquid crystal composition;
Forming a liquid crystal cell filled with the liquid crystal composition to which the photoreactive chiral agent is added;
Irradiating ultraviolet rays to the liquid crystal cell through a photo mask at a temperature higher than room temperature, thereby forming a plurality of subpixels having different selective reflection wavelengths according to the irradiation amount of the ultraviolet rays. Manufacturing method.
&Lt; General Formula 1 &

In Formula 1, Ar is a substitutable aromatic group, R1 and R2 are substituents in which C * forms an asymmetric carbon, R3 is -CONH-, -COO-, or -C = N-, and R4 is XBA And A is a substitutable aromatic group, B is a planar conjugated group and X is a residual group including a substitutable aromatic group. The method according to claim 1,
The ultraviolet irradiation is carried out at a temperature of more than 25 ℃ 150 ℃ or less method for producing a cholesteric liquid crystal display. The method according to claim 2,
The photoreactive chiral agent is a manufacturing method of a cholesteric liquid crystal display, characterized in that represented by the following formula (1).
&Lt; Formula 1 >

The method according to claim 2,
The photo mask is a halftone mask, characterized in that the manufacturing method of the cholesteric liquid crystal display. The method according to claim 4
The irradiated ultraviolet light has a peak wavelength of 250 ~ 300 nm method for producing a cholesteric liquid crystal display. The method of claim 4,
A blue subpixel reflecting a blue wavelength is formed in a region corresponding to the blocking portion of the halftone mask that blocks the irradiated ultraviolet rays,
A green subpixel reflecting a green wavelength is formed in a region corresponding to a halftone transmission portion of the halftone mask that blocks a portion of the irradiated ultraviolet rays,
And a red subpixel reflecting a red wavelength in a region corresponding to the transmissive portion of the halftone mask that transmits the irradiated ultraviolet rays. The method according to claim 1,
And said photoreactive chiral agent is added to said liquid crystal composition in an additive amount such that the selective reflection wavelength of said liquid crystal composition maintains a wavelength below the blue wavelength range. The method of claim 7,
The addition amount of the said photoreactive chiral agent is 0.1 mass% or more and less than 8 mass%, The manufacturing method of the cholesteric liquid crystal display characterized by the above-mentioned. The method of claim 7,
And said liquid crystal composition further comprises a chiral agent having no photoreactivity until said selective reflection wavelength reaches a red wavelength region.

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