JP2002080851A - Photoreactive chiral agent, liquid crystal composition, liquid crystal color filter, optical film, recording medium, and method for changing twist structure of liquid crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoreactive chiral agent which has a photosensitivity and can greatly change the spiral pitch (twisting force) of a liquid crystal by light. SOLUTION: This photoreactive chiral agent comprises a compound represented by formula (I) (R is a hydrogen atom or a 1-15C alkoxy, 3-15C acryloyloxyalkyloxy or 4-15C methacryloyloxyalkyloxy group) and changes the twisting force of a liquid crystal by the irradiation with light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel photoreactive chiral agent which causes a change in the structure of a liquid crystal, a liquid crystal composition containing the same, an optical film, a liquid crystal color filter and a recording medium, and a helical twist of the liquid crystal. It relates to a method of changing the structure.

[0002]

2. Description of the Related Art In recent years, liquid crystal materials such as cholesteric liquid crystals having a helical structure and exhibiting various selective reflection colors due to the twisting force (twist angle) of the spiral have attracted attention. Because of its excellent color purity of reflected light, it is widely used for optical films, liquid crystal color filters, recording media, and the like. For example, a color filter used for a color liquid crystal display or the like generally includes red (R), green (G), and blue (B) pixels, and a black matrix for improving display contrast is formed between the pixels. It is composed. Conventionally, such color filters are mainly those in which a pigment is dispersed in a resin or dyes are dyed, and the production method is also such that a colored resin liquid is applied onto a glass substrate by spin coating or the like. In general, a method of forming a color resist layer and performing patterning by a photolithography method to form a color filter pixel or printing a color pixel directly on a substrate has been common.

[0003] However, for example, the manufacturing method by the printing method has a disadvantage that it is difficult to form a high-definition image pattern with a low pixel resolution, and the manufacturing method by the spin coating method causes a large material loss and a large loss. There is a drawback that coating unevenness when coating on a substrate having a large area is large. Further, according to the production method by the electrodeposition method, it is possible to obtain a color filter having relatively high resolution and less unevenness of the colored layer, but has a disadvantage that the production process is complicated and liquid management is difficult. As described above, as a process for manufacturing a color filter, there has been a demand for a manufacturing method capable of easily and easily manufacturing a high-quality color filter with little material loss.

On the other hand, the performance of a color filter is required to be high in transmittance and color purity. In recent years, a method using a dye has been optimizing a type of a dye and a dyeing resin, and a method using a pigment has become more difficult. The use of finely dispersed pigments has improved the above requirements. However, in recent liquid crystal display (LCD) panels, the requirements for the transmittance and color purity of color filters are extremely high. Particularly, in color filters for reflective LCDs, white display of paper white, contrast, and color reproducibility are both compatible. Is difficult, but in the conventional manufacturing method,
Color filters manufactured by dyeing a dye in a resin or dispersing a pigment are all light-absorbing color filters, so the improvement in color purity by further improving transmittance is almost at its limit. Had reached.

Under such circumstances, a polarization type color filter mainly comprising cholesteric liquid crystal has been known. This polarization-based color filter reflects a certain amount of light and transmits the rest to display an image, so it has high light use efficiency and is superior to the light absorption type color filter in terms of transmittance and color purity. It has the performance which it did. On the other hand, in the manufacturing method, from the viewpoint of obtaining a uniform thickness, a method of forming a film on a substrate by using a spin coating method or the like has been generally performed. Was disadvantageous.

A photoreactive chiral compound (chiral compound) has been proposed as a means for solving the above problems, ensuring uniformity of the color purity and the like of the color filter film, and reducing the number of manufacturing steps. Is useful.
In this method, when a liquid crystal composition containing a photoreactive chiral compound is irradiated with light having a reaction wavelength of the chiral compound in a pattern, the reaction of the chiral compound proceeds in accordance with the intensity of the irradiation energy, and the reaction of the liquid crystal compound proceeds. Since the helical pitch (helical twist angle) changes, the principle is used that a selective reflection color is formed for each pixel only by pattern exposure with a light amount difference. That is, there is an advantage that the number of times of patterning at the time of forming the color filter can be completed by one mask exposure using masks having different transmitted light amounts. Therefore, after patterning by irradiating light like an image,
By fixing the patterned cholesteric liquid crystal compound, a film functioning as a color filter can be formed. This can be applied to optical films, image recording, and the like.

In particular, when a color filter is manufactured by a single mask exposure, B (blue), G (green),
It is desired that three primary colors (red) can be formed with high color purity by one exposure. However, when the rate of change of the twist of the liquid crystal is small, sufficient color purity cannot be obtained. Therefore, from the viewpoint of displaying three primary colors having high color purity in one exposure, practically, as a photoreactive chiral compound to be used, the twisting force of the helical structure of the liquid crystal compound can be largely changed, It is necessary to use a chiral compound (chiral agent) having a large value. That is, by using a chiral compound having a large twist change rate, the width of the hue selectively reflected by the change in the amount of light is expanded.

Japanese Patent Application Laid-Open No. H11-248943 discloses that a polymerizable mesogen compound having an isosorbide skeleton in a chiral mother nucleus is used as a chiral compound constituting a broadband reflective polarizing plate. This polymerizable mesogen compound can change the helical structure of the liquid crystal by acting on the liquid crystal compound. However, when the reflection wavelength band of the polarizing plate described in the publication, that is, the helical structure of the liquid crystal (helical twisting force) is changed so as to exhibit a desired selective reflection, the change is adjusted by the mesogenic compound and the non-chiral compound. It is carried out according to the mixing ratio (use amount) with the compound (liquid crystal), and the light and its light quantity are not involved at all. That is, the publication does not suggest that the helical structure of the liquid crystal (helical twisting force) is changed by a change in the amount of light, and the compounds exemplified in the publication are useful in terms of the rate of change of the twisting force with respect to light. No suggestion is made.

As described above, the cholesteric liquid crystal phase having a photoreactivity capable of changing the alignment structure such as the helical pitch (twisting force, helical torsion angle) of the liquid crystal depending on the amount of light to be irradiated, and further including, for example, a nematic liquid crystal compound. In the case of, a wide range of wavelength regions that can be selectively reflected shows a wide variety of selective reflection,
In particular, a photoreactive chiral agent (photoreactive chiral agent) capable of greatly changing the helical pitch (twisting force), such as being able to display the three primary colors (B, G, R) with high color purity, is still available. It is currently not provided.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, in the present invention, first, the orientation of the liquid crystalline compound can be controlled, and the rate of change of the twisting force (twist angle, helical pitch) of the liquid crystal by light (hereinafter, referred to as the “twist rate of change”) may be referred to. ) Is large, for example, in the case of a cholesteric liquid crystal phase, a wide range of selective reflection including three primary colors (B, G, R) is possible, and a photoreactive chiral agent capable of displaying three primary colors with high color purity is provided. The purpose is to: Secondly, light can change the torsional force of the liquid crystal and contain a photoreactive chiral agent having a large rate of change in the twist, and the light can change the optical properties by controlling the orientation state of the liquid crystal molecules three-dimensionally. In the case of a liquid crystal composition, for example, a cholesteric liquid crystal, the object is to provide a liquid crystal composition which exhibits a wide range of selective reflection colors including three primary colors by light irradiation, and is capable of displaying the three primary colors with excellent color purity. I do.

[0013] Third, the present invention provides a liquid crystal composition containing a photoreactive chiral agent having a high rate of change in twist, which is capable of greatly changing the twisting force (torsion angle) of the liquid crystal by irradiating light to the liquid crystal composition. It is an object to provide a method for changing the structure. Fourth, it is an object of the present invention to provide a liquid crystal color filter having a high color purity, including a photoreactive chiral agent capable of greatly changing the twisting force of liquid crystal by light irradiation. Fifth, a non-light-absorbing optical film containing a photoreactive chiral agent that can significantly change the twisting force of the liquid crystal by light irradiation, for example, in the case of a cholesteric liquid crystal phase, has a wide selective reflection area and high color purity. It is intended to provide an optical film.
Sixth, a recording medium containing a photoreactive chiral agent capable of greatly changing the twisting force of liquid crystal by light irradiation and capable of forming a clear image by changing the amount of light in an image-like manner, for example, a cholesteric liquid crystal phase In the case of (1), an object is to provide a recording medium capable of forming an image composed of a selective reflection color having a wide hue and a high color purity.

[0012]

Means for solving the above problems are as follows. That is, <1> a compound represented by the following general formula (I),
It is a photoreactive chiral agent characterized by changing the twisting force of liquid crystal by light irradiation.

[0013]

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Wherein R is a hydrogen atom, having 1 to 15 carbon atoms.
An acryloyloxyalkyloxy group having a total of 3 to 15 carbon atoms, and a methacryloyloxyalkyloxy group having a total of 4 to 15 carbon atoms. ]

<2> In the compound represented by the formula (I), R is an acryloyloxyalkyloxy group having a total of 3 to 15 carbon atoms or a methacryloyloxyalkyloxy group having a total of 4 to 15 carbon atoms. 1> The photoreactive chiral agent described in <1>. <3> In the compound represented by the general formula (I),
Is a hydrogen atom and a C1-C15 alkoxy group in the photoreactive chiral agent according to <1>.

<4> A liquid crystal composition comprising at least one selected from the photoreactive chiral agents according to any one of <1> to <3>. <5> The liquid crystal composition according to <4>, containing at least a photoreactive chiral agent, a cholesteric liquid crystal compound, and a surfactant. As the surfactant, a nonionic surfactant is preferable.

<6> A method for changing the twisted structure of a liquid crystal, characterized in that the liquid crystal composition according to the above <4> or <5> is irradiated with light to change the twisting force of the liquid crystal. <7> A liquid crystal color filter comprising at least one selected from the photoreactive chiral agents according to any one of <1> to <3>.

<8> An optical film comprising at least one selected from the photoreactive chiral agents described in any one of <1> to <3>. <9> A recording medium comprising at least one selected from the photoreactive chiral agents according to any one of <1> to <3>.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in order. <Photoreactive Chiral Agent> The photoreactive chiral agent of the present invention comprises a compound represented by the following general formula (I), can control the alignment structure of a liquid crystalline compound, and emit light by irradiating liquid crystal. Pitch, ie, the twisting force of the helical structure (HTP:
(Helical twisting power) can be changed. That is, it is a compound that causes a change in the twisting force of the helical structure induced in a liquid crystal compound, preferably a nematic liquid crystal compound, by light irradiation (ultraviolet light to visible light to infrared light). It has a site (chiral site) and a site that undergoes a structural change by light irradiation. Moreover, the photoreactive chiral agent represented by the following general formula (I) can greatly change the HTP of liquid crystal molecules in particular. Therefore, for example, in the case of a cholesteric liquid crystal (liquid crystal phase) using a nematic liquid crystal compound as a liquid crystal compound, selection over a wide wavelength range including three primary colors of B (blue), G (green), and R (red). Reflection becomes possible. That is, since the selective reflection characteristic of the light wavelength is determined by the twist angle of the helical structure of the liquid crystal molecules, the color width of the selective reflection becomes wider and useful as the angle greatly changes.

The HTP represents the twisting force of the helical structure of the liquid crystal, that is, HTP = 1 / (pitch × concentration of chiral agent [mass fraction]). For example, the helical pitch of liquid crystal molecules at a certain temperature ( One cycle of the helical structure; μm) is measured, and this value can be obtained by converting [μm ⁻¹ ] from the concentration of the chiral agent (chiral agent). When a selective reflection color is formed by the illuminance of light using a photoreactive chiral agent, the change rate of the HTP (= HTP before irradiation / HTP after irradiation) is as follows. 5 or more, more preferably 2.5 or more, and HT after irradiation.
When P becomes larger, it is preferably 0.7 or less, and more preferably 0.4 or less.

Next, the compound represented by formula (I) will be described.

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In the above formula, R is a hydrogen atom, having 1 to 1 carbon atoms.
5 represents an alkoxy group, an acryloyloxyalkyloxy group having 3 to 15 carbon atoms, and a methacryloyloxyalkyloxy group having 4 to 15 carbon atoms. 1 to 1 carbon atoms
Examples of the 5 alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, and a dodecyloxy group.
To 12 alkoxy groups are preferable, and an alkoxy group having 1 to 8 carbon atoms is particularly preferable.

Examples of the acryloyloxyalkyloxy group having 3 to 15 carbon atoms include an acryloyloxyethyloxy group, an acryloyloxybutyloxy group and an acryloyloxydecyloxy group.
Among them, an acryloyloxyalkyloxy group having 5 to 13 carbon atoms is preferable, and an acryloyloxyalkyloxy group having 5 to 11 carbon atoms is particularly preferable.

Examples of the methacryloyloxyalkyloxy group having 4 to 15 carbon atoms include a methacryloyloxyethyloxy group, a methacryloyloxybutyloxy group, and a methacryloyloxydecyloxy group. Is preferable, and a methacryloyloxyalkyloxy group having 6 to 12 carbon atoms is particularly preferable.

The molecular weight of the photoreactive chiral agent represented by the general formula (I) is preferably 300 or more. Further, those having high solubility with a liquid crystal compound described later are preferable, and those having a solubility parameter SP value close to that of the liquid crystal compound are more preferable.

Hereinafter, specific examples (exemplified compounds (1) to (15)) of the compound represented by the general formula (I) will be shown, but the present invention is not limited thereto.

[0027]

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[0028]

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[0029]

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Next, a synthesis example of the photoreactive chiral agent (compound represented by the general formula (I)) of the present invention will be described. In addition, the number in parentheses of the photoreactive chiral agent is the above [Formula 4]-
Photoreactive chiral agent exemplified in Chemical Formula 6 (exemplary compound)
Represents the number.

Synthesis of Photoreactive Chiral Agent (2) 4-Methoxycinnamic acid (15 g, 0.084 mole) and dimethylformamide (2 to 3 drops) are dissolved in tetrahydrofuran (100 mL), and oxalyl chloride is further added thereto. (10 mL, 0.13 mole) dissolved in tetrahydrofuran (50 mL) was added dropwise and reacted for 2 hours. After distilling off the solvent and excess oxalyl chloride in the reaction solution under reduced pressure, the mixture was diluted with tetrahydrofuran (100 mL), and isosorbide (5.5 g, 0.038 mole) was used.
Was added. With further stirring, tetrahydrofuran (5
Pyridine (27 mL, 0.33 mol) dissolved in
le) was added dropwise and stirred for 3 hours. Then, 10
% Hydrochloric acid (100 mL) and ethyl acetate (200 mL) were added, stirred, and separated. The obtained organic layer was washed once with a saturated saline solution (100 mL) and twice with a saturated aqueous sodium hydrogen carbonate solution (100 mL).
It was washed twice with saturated saline (100 mL) twice and dried over magnesium sulfate. After the organic solvent was further distilled off under reduced pressure, the residue was purified by silica gel column chromatography using a mixed solution of n-hexane-ethyl acetate (3: 2 v / v) as a developing solvent, and recrystallized (n-hexane-ethyl acetate).
Was performed to obtain colorless crystals (9.8 g, 56%).

The results (data) of identifying the colorless crystals obtained above are shown below. Melting point Tm = 113.7 ° C., [α] _D ²⁵ -158 ° (c0.
50, EtOAc). ¹ H-NMR (CDCl ₃ ): δ (in ppm from tetrame)
thylsilane) 7.75-7.60 (2H, dd), 7.
50-7.45 (4H, dd), 6.94-6.88
(4H, dd), 6.40-6.25 (2H, dd),
5.36-5.26 (2H, m), 4.95 (1H,
t), 4.60 (1H, d), 4.15-3.90 (8
H, m), 3.85 (6H, s).

Synthesis of Photoreactive Chiral Agent (5) trans-4-Coumaric acid (20 g, 0.12 mole)
And potassium carbonate (33 g, 0.24 mole) were dispersed in dimethylformamide (100 mL), and n-bromobutane (50 g, 0.37 mol) was heated on an oil bath.
le) was added dropwise. After stirring for 3 hours, insolubles were filtered off, diluted with ethyl acetate (400 mL), and washed with saturated saline (200 mL). After the organic solvent was further distilled off under reduced pressure, a solution of ethanol (100 mL) and potassium hydroxide (20 g, 0.36 mole) dissolved in water (50 mL) was added, and the mixture was refluxed for 1 hour. The reaction solution was poured into dilute hydrochloric acid, and the precipitated crystals were separated by filtration.
L). The obtained organic layer was washed with saturated saline and dried over magnesium sulfate. Further, after the organic solvent was distilled off under reduced pressure, recrystallization (n-hexane-ethyl acetate) was carried out to obtain colorless crystals of 4-n-butoxycinnamic acid (22.7).
g, 84%).

The obtained 4-n-butoxycinnamic acid (5 g,
0.023 mole) and dimethylformamide (2-
3 drops) was dissolved in tetrahydrofuran (50 mL), and oxalyl chloride (2.9 mL, 0.034 mol) was added thereto.
le) dissolved in tetrahydrofuran (30 mL) was added dropwise and reacted for 2 hours. After distilling off the solvent of the reaction solution and excess oxalyl chloride under reduced pressure, the mixture was diluted with tetrahydrofuran (50 mL), and isosorbide (1.5 mL) was added.
g, 0.010 mole). With further stirring, pyridine (11 mL, 0.14 mole) dissolved in tetrahydrofuran (20 mL) was added dropwise, and the mixture was stirred for 3 hours. Thereafter, 10% hydrochloric acid (50 mL) and ethyl acetate (100 mL) were added to the reaction solution, and the mixture was stirred and separated.
The obtained organic layer was washed once with a saturated saline solution (50 mL), twice with a saturated sodium bicarbonate solution (50 mL), twice with a saturated saline solution (50 mL), and dried over magnesium sulfate. Further, after the organic solvent was distilled off under reduced pressure, the residue was purified by silica gel column chromatography using a mixed solution of n-hexane-ethyl acetate (2: 1 v / v) as a developing solvent, and recrystallized (n-hexane).
Hexane-ethyl acetate) to give a colorless crystalline powder (1.
4 g, 25%).

The results (data) of identifying the colorless crystalline powder obtained above are shown below. Melting point Tm = 132.4 ° C., [α] _D ²⁵ -115.0 ° (c
0.10, EtOAc). ¹ H-NMR (CDCl ₃ ): δ (in ppm from tetram
ethylsilane) 7.75-7.65 (2H, dd),
7.50-7.45 (4H, dd), 6.90-6.8
5 (4H, dd), 6.40-6.26 (2H, d
d), 5.35-5.25 (2H, m), 4.94 (1
H, t), 4.60 (1H, d), 4.13-3.95
(8H, m), 1.94-1.65 (4H, m), 1.
55-1.44 (4H, m), 0.95 (6H, t).

Synthesis of Photoreactive Chiral Agent (12) trans-4-Coumaric acid (20 g, 0.12 mol)
e), potassium iodide (24 g, 0.14 mole) and potassium carbonate (85 g, 0.62 mole) were added to dimethylformamide (200 mL) and water (100 mL).
And 6-chlorohexanol (68 g, 0.50 mole) was added dropwise while heating in an oil bath.
After stirring for 3 hours, the mixture was diluted with ethyl acetate (400 mL) and washed with saturated saline (400 mL). After the organic solvent was further distilled off under reduced pressure, ethanol (200 mL) and potassium hydroxide (20 g, 0.36 mole) were added to water (50 mL).
mL), and refluxed for 1 hour. The reaction mixture was poured into dilute hydrochloric acid, and the precipitated crystals were separated by filtration and dried to obtain colorless crystalline powder of 4- (6-hydroxyhexyloxy) cinnamic acid (22 g, 64%).

The obtained 4- (hydroxyhexyloxy) cinnamic acid (6 g, 0.023 mole) and N, N-
Dimethylaniline (6.6 g, 0.054 mole) was dissolved in tetrahydrofuran (50 mL), and further acroyl chloride (4.4 g, 0.049 mole) dissolved in tetrahydrofuran (20 mL) at room temperature.
Was added dropwise. After stirring for 4 hours after dropping, the reaction solution was reduced to 10%
The mixture was poured into hydrochloric acid, and the precipitated crystals were separated by filtration. The obtained crude crystals were dissolved in ethyl acetate (100 mL), and the organic layer was washed with brine and dried over magnesium sulfate. After the organic solvent was distilled off under reduced pressure, the crude crystals were recrystallized (n-hexane-
Ethyl acetate) and colorless crystalline powder of 4- (6-acroyloxyhexyloxy) cinnamic acid (3.9 g, 54%)
I got

The obtained 4- (6-acroyloxyhexyloxy) cinnamic acid (3 g, 9.4 mmole) and dimethylformamide (2 to 3 drops) were dissolved in tetrahydrofuran (50 mL), and oxalyl microchloride was further added thereto. (1.2 mL, 0.014 mole) dissolved in tetrahydrofuran (10 mL) was added dropwise and reacted for 2 hours. After evaporating the solvent and excess oxalyl chloride in the reaction solution under reduced pressure, the mixture was diluted with tetrahydrofuran (50 mL), and isosorbide (0.6 g, 4.1 mmole) was added. With further stirring, tetrahydrofuran (20
pyridine (4.5 mL, 0.056 m) dissolved in
ole) was added dropwise and stirred overnight. Then, add 1
0% hydrochloric acid (50 mL) and ethyl acetate (100 mL) were added, and the mixture was stirred and separated. The obtained organic layer was washed once with a saturated saline solution (50 mL) and twice with a saturated sodium bicarbonate solution (50 mL).
The extract was washed with a saturated saline solution (50 mL) twice, and dried over magnesium sulfate. After evaporating the organic solvent under reduced pressure, n
Purification by silica gel column chromatography using a mixed solution of -hexane-ethyl acetate (3: 2 v / v) as a developing solvent gave a colorless crystalline powder (1.1 g, 38%).

The results (data) of identifying the colorless crystalline powder obtained above are shown below. Melting point Tm = 70.5 ° C., [α] _D ²⁵ -103.0 ° (c
0.11, EtOAc). ¹ H-NMR (CDCl ₃ ): δ (in ppm from tetram
ethylsilane) 7.75-7.65 (2H, dd),
7.50-7.45 (4H, dd), 6.92-6.8
8 (4H, dd), 6.45-5.88 (8H, m),
5.35-5.25 (2H, m), 4.95 (1H,
t), 4.60 (1H, d), 4.20-3.85 (8
H, m), 1.94-1.65 (4H, m), 1.85
-1.45 (16H, m).

The photoreactive chiral agent represented by the general formula (I) can greatly change the twisting power of the helical structure of the liquid crystal, and one or more polymerizable bonding groups are introduced into the structure. In the case of such a structure, the heat resistance of the liquid crystal composition or a liquid crystal composition containing the same, for example, a liquid crystal color filter, an optical film, or the like can be improved.

The photoreactive chiral agent of the present invention can be used in combination with a chiral agent having no photoreactivity, such as a chiral compound having a large temperature dependence of torsional force. Known chiral agents having no photoreactivity include, for example, JP-A-20
00-44451, Tokiohei 10-509726, W
O98 / 00428, JP-T-2000-506873,
Tokuhyo Hei 9-5060888, Liquid Cryst
als (1996, 21, 327), Liquid C
crystall (1998, 24, 219) and the like.

<Liquid crystal composition> The liquid crystal composition contains at least one selected from the photoreactive chiral agents of the present invention, and further contains at least one liquid crystal compound (preferably a nematic liquid crystal compound). The liquid crystal compound may or may not have a polymerizable group. Also, if necessary, other components such as a polymerizable monomer, a polymerization initiator, a binder resin, a solvent, a surfactant, a polymerization inhibitor, a thickener, a dye, a pigment, an ultraviolet absorber, and a gelling agent. May be included. In the liquid crystal composition of the present invention, it is particularly preferable to use a surfactant in combination. For example, when a liquid crystal composition in a coating liquid is applied to form a layer, the alignment state at the air interface on the layer surface can be three-dimensionally controlled, and a selective reflection wavelength with higher color purity can be obtained.

(Photoreactive Chiral Agent) The photoreactive chiral agent includes the above-described photoreactive chiral agent of the present invention, and controls the alignment structure of liquid crystal molecules three-dimensionally and has a desired pattern and light amount. The light irradiation changes the helical structure of a coexisting liquid crystal compound, preferably a nematic liquid crystal compound. In a system containing a nematic liquid crystal compound, a selective reflection color in a wide wavelength range can be developed. The content of the photoreactive chiral agent in the liquid crystal composition is not particularly limited and can be appropriately selected.
About 30% by mass is preferable.

(Liquid crystal compound) As the liquid crystal compound,
The refractive index anisotropy Δn can be appropriately selected from a liquid crystal compound having a refractive index anisotropy of 0.10 to 0.40, a polymer liquid crystal compound, and a polymerizable liquid crystal compound. For example, a smectic liquid crystal compound, a nematic liquid crystal compound, etc. can be mentioned, and among them, a nematic liquid crystal compound is preferable. For example, a cholesteric liquid crystal composition (cholesteric liquid crystal phase) can be obtained by using a nematic liquid crystal compound as the liquid crystal compound and using the photoreactive chiral agent represented by the general formula (I) in combination. The liquid crystal compound can be aligned while in a liquid crystal state at the time of melting, for example, by using an alignment substrate that has been subjected to an alignment process such as a rubbing process. In the case where the liquid crystal state is solid phase and immobilized, means such as cooling and polymerization can be used.

Specific examples of the liquid crystal compound include the following compounds. However, the present invention is not limited to these.

[0046]

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[0047]

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[0048]

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In the above formula, n represents an integer of 1 to 1000. In each of the above exemplified compounds, those in which the connecting group of the aromatic ring is changed to the following structure can also be mentioned as suitable compounds.

[0050]

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Among the above, from the viewpoint of ensuring sufficient curability and heat resistance of the layer, liquid crystalline compounds having a polymerizable group or a crosslinkable group in the molecule are preferred.

The content of the liquid crystal compound is preferably from 30 to 99.9% by mass, more preferably from 50 to 95% by mass, based on the total solids (mass) of the liquid crystal composition. If the content is less than 30% by mass, the orientation may be insufficient, and particularly in the case of cholesteric liquid crystal, a desired selective reflection color may not be obtained.

(Polymerizable Monomer) The liquid crystal composition of the present invention may be used in order to improve the degree of curing such as film strength.
A polymerizable monomer may be used in combination. When the polymerizable monomer is used in combination, the helical structure (selective reflectivity) is fixed after changing (patterning) the torsional force of the liquid crystal due to light irradiation (for example, after forming the distribution of the selective reflection wavelength). The strength of the liquid crystal composition after the formation can be further improved. However, when the liquid crystal compound has an unsaturated bond in the same molecule, it is not always necessary to add.

Examples of the polymerizable monomer include monomers having an ethylenically unsaturated bond, and specific examples thereof include polyfunctional monomers such as pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate. Specific examples of the monomer having an ethylenically unsaturated bond include the following compounds, but are not limited to these in the present invention.

[0055]

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The amount of the polymerizable monomer to be added is preferably 0.5 to 50% by mass of the total solid content (mass) of the liquid crystal composition. If the amount is less than 0.5% by mass, sufficient curability may not be obtained. If the amount exceeds 50% by mass, the alignment of liquid crystal molecules is inhibited, and sufficient color formation cannot be obtained. Sometimes.

(Photopolymerization Initiator) The liquid crystal composition of the present invention may contain a photopolymerization initiator, and the polymerization reaction of the polymerizable group is promoted by using the photopolymerization initiator in combination. By fixing the helical structure after changing the helical pitch (twisting force), the strength of the liquid crystal composition after the fixing can be further improved. When a polymerization reaction by a polymerizable liquid crystal compound is used to fix the helical structure of the liquid crystal, it is preferable to add a photopolymerization initiator. For example, when the liquid crystal phase is a cholesteric liquid crystal phase, a desired helical pitch can be stably obtained, and a selective reflection color with high color purity can be secured.

The photopolymerization initiator can be appropriately selected from known ones, for example, p-methoxyphenyl-2,4-bis (trichloromethyl) -s-triazine, 2- (p-butoxy) Styryl) -5-trichloromethyl 1,3,4-oxadiazole, 9-phenylacridine, 9,10-dimethylbenzphenazine,
Benzophenone / Michler's ketone, hexaarylbiimidazole / mercaptobenzimidazole, benzyldimethyl ketal, thioxanthone / amine, triarylsulfonium hexafluorophosphate, etc. -Acyl phosphine oxides described in JP-A-299997, Luci
Acylphosphine oxides described in DE4230555 such as rinTPO and the like.

The addition amount of the photopolymerization initiator is preferably from 0.1 to 20% by mass, more preferably from 0.5 to 5% by mass, based on the total solids (mass) of the liquid crystal composition. If the amount is less than 0.1% by mass, the curing efficiency at the time of light irradiation is low, so that it may take a long time. If the amount exceeds 20% by mass, the light transmittance from the ultraviolet region to the visible light region may be required. May be inferior.

(Other Components) Further, other components include a binder resin, a solvent, a surfactant, a polymerization inhibitor, a thickener,
Dyes, pigments, ultraviolet absorbers, gelling agents and the like can also be added. Examples of the binder resin include polystyrene, polystyrene compounds such as poly-α-methylstyrene, cellulose resins such as methylcellulose, ethylcellulose and acetylcellulose, acidic cellulose derivatives having a carboxyl group in a side chain, polyvinylformal, polyvinylbutyral and the like. Acetal resin of JP-A-59-44615, JP-B-54-34327, JP-B-58-12577, JP-B-54-25957,
Methacrylic acid copolymers and acrylic acid copolymers described in JP-A-59-53836 and JP-A-59-71048;
Examples include an itaconic acid copolymer, a crotonic acid copolymer, a maleic acid copolymer, a partially esterified maleic acid copolymer, and the like.

The homopolymer of an alkyl acrylate and the homopolymer of an alkyl methacrylate are also exemplified. In these, the alkyl group is a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an iso-alkyl group.
-Butyl group, n-hexyl group, cyclohexyl group, 2-
Examples thereof include an ethylhexyl group. In addition, a polymer having a hydroxyl group to which an acid anhydride is added, a benzyl (meth) acrylate / (homopolymer of methacrylic acid) acrylic acid copolymer or benzyl (meth) acrylate / (meth) acrylic acid / other monomer And the like.

The content of the binder resin in the liquid crystal composition is preferably from 0 to 50% by mass, more preferably from 0 to 30% by mass. If the content exceeds 50% by mass, the orientation of the liquid crystalline compound may be insufficient.

In the liquid crystal composition of the present invention, it is preferable to use a surfactant together with the photoreactive chiral agent and the liquid crystal compound from the viewpoint of further improving the color purity of the hue that selectively reflects. As the surfactant, a surfactant having an excluded volume effect is preferable. Here, exerting the excluded volume effect means, for example, when a layer containing a liquid crystal composition is formed by coating, three-dimensionally controlling the spatial alignment state at the air interface on the surface of the layer. Specifically, a nonionic surfactant is preferable, and a nonionic surfactant can be appropriately selected from known nonionic surfactants.

The polymerization inhibitor may be added for the purpose of improving the storage stability. Examples include hydroquinone, hydroquinone monomethyl ether, phenothiazine, benzoquinone, and derivatives thereof. The addition amount of the polymerization inhibitor is 0 to 1 with respect to the polymerizable monomer.
0 mass% is preferable, and 0 to 5 mass% is more preferable.

The liquid crystal composition of the present invention can be prepared by dissolving and dispersing each of the above-mentioned components in an appropriate solvent, and can be used by shaping it into an arbitrary shape or forming it on a support or the like. . Here, examples of the solvent include 2-butanone, cyclohexanone, methylene chloride, chloroform and the like.

<Method for Changing Twisted Structure of Liquid Crystal> As described above, the liquid crystal composition of the present invention contains a photoreactive chiral agent. The liquid crystal composition of the present invention is irradiated with light while changing the amount of light to change the twisting force of the liquid crystal, thereby forming regions having different twisting structures of the liquid crystal. That is, by irradiating the liquid crystal composition with a desired amount of light in a desired pattern, the twist structure of the liquid crystal, that is, the degree of the twist of the helix (twist force; HT)
P) can be changed, and the selective reflection color indicated by the liquid crystal can be arbitrarily changed according to the twisting force.

In particular, when the liquid crystal phase is a cholesteric liquid crystal phase, the selective reflection color of the liquid crystal can be arbitrarily changed according to the twisting force. When the rate of change of the twisting force is large, the color width of the selective reflection color that the liquid crystal can selectively reflect is widened, and it is possible to obtain selective reflection in a wide wavelength range including three primary colors (B, G, R). This is especially true for B
This is important in that the three primary colors of GR can be displayed with high color purity. In this regard, in particular, the photoreactive chiral agent represented by the general formula (I) described above can greatly change the twisting power of the helical structure of the liquid crystal, and therefore uses a liquid crystal composition containing the chiral agent. By the blue
A wide range of hues including the three primary colors (B), green (G) and red (R) can be displayed with high color purity, and three primary colors with excellent color purity can be obtained.

Specifically, it can be performed as follows. That is, when the liquid crystal composition is irradiated with light of a certain wavelength, the co-existing photoreactive chiral agent responds to the irradiation intensity and changes the helical structure (twist angle) of the liquid crystal. An image-like pattern showing a color is formed (patterning). Cholesteric liquid crystal compositions exhibit different selective reflection colors due to this structural change. Therefore, by changing the irradiation intensity for each desired area and irradiating light,
Orientation (presenting multiple colors) corresponding to the irradiation intensity, for example,
By exposing through an exposure mask formed by changing the light transmittance like an image, it is possible to simultaneously form an image, that is, a colored region having different selective reflection by one light irradiation.

Further, the helical pitch of the liquid crystal can be largely changed because it depends on the compound represented by the general formula (I). In the case of the cholesteric liquid crystal composition, the formed colored region has a wide selective reflection. The three primary colors of BGR exhibiting color and having excellent color purity can be formed. This light irradiation can be performed without any particular limitation as long as the irradiation intensity can be changed for each desired region, in addition to the method using an exposure mask. In the case of forming a liquid crystal color filter, an optical film, or the like described below, after patterning by exposing the light of a certain wavelength imagewise as described above, the polymerizable group in the liquid crystal composition is further irradiated with light. The polymer is cured by photopolymerization, and the helical structure of the liquid crystal is fixed to a desired selective reflection color. Details of these forming methods will be described later.

Utilizing the fact that the change rate of the helical pitch induced in the liquid crystal phase by light irradiation due to the photoreactive chiral agent represented by the general formula (I) is large,
An optical film such as a circularly polarized light separating film, stereoscopic glasses, a polarizing mask, and the like can be formed. Further, application to a broadband switchable mirror, an optical writing type recording medium, or the like is also possible. Ferroelectric liquid crystal, antiferroelectric liquid crystal, T
By doping the GB phase, patterning of the polarization state and patterning of the helical pitch can be performed. Naturally, it can be used as an ordinary optically active compound.
Application to a TN device or a helical structure inducer in a TN device is also possible. Further, the liquid crystal composition of the present invention may contain a non-chiral azo or styrene-based compound which isomerized by light, thereby further increasing the rate of change of the helical pitch during light irradiation. There is.

The light source used for light irradiation is preferably a light source that emits ultraviolet light because it has a high energy and can rapidly change the structure of the liquid crystal compound and the polymerization reaction. Examples thereof include a high-pressure mercury lamp, a metal halide lamp, and an Hg-Xe lamp. And the like. Further, it is preferable to have a light quantity variable function.

As described above, when the liquid crystal composition containing the chiral agent represented by the general formula (I) is used, the twisting force of the helical structure of the liquid crystal with respect to the amount of light can be greatly changed. Therefore, for example, in the case of a cholesteric liquid crystal phase using a nematic liquid crystal compound as the liquid crystal compound,
The color width of the selective reflection color that the liquid crystal can exhibit is expanded, and three primary colors of blue (B), green (G), and red (R) with excellent color purity can be obtained.

<Liquid Crystal Color Filter> The liquid crystal color filter of the present invention preferably contains at least one selected from the photoreactive chiral agents of the present invention and further contains at least one liquid crystalline compound. As the liquid crystal compound, a nematic liquid crystal compound is most preferable. The liquid crystal composition of the present invention may further contain, if necessary, other components such as a polymerizable monomer, a photopolymerization initiator, and a surfactant having an excluded volume effect. It can be manufactured by irradiating light with a desired pattern and light amount appropriately selected based on the method of changing the twist structure of the liquid crystal described above.

Hereinafter, the liquid crystal color filter of the present invention will be described in detail through the description of the method of manufacturing the liquid crystal color filter. The liquid crystal color filter of the present invention can be prepared by appropriately selecting from the above-mentioned liquid crystal composition of the present invention and a known composition containing the compound represented by the general formula (I). . In this case, the liquid crystal composition may be in the form of a sheet composed only of the liquid crystal composition, or in a mode in which a layer (liquid crystal layer) containing the liquid crystal composition is provided on a desired support or temporary support. And another layer (film) such as an alignment film or a protective film may be provided. In the latter case, two or more liquid crystal layers can be laminated, and in this case, the exposure step described later is provided a plurality of times.

As the nematic liquid crystal compound, the polymerizable monomer, the photopolymerization initiator and other components, those usable in the liquid crystal composition of the present invention can be used.
The content, preferred range, and the like are the same as in the case of the liquid crystal composition. It is preferable to use a surfactant having an excluded volume effect in combination. Further, the content of the compound represented by the general formula (I) in the liquid crystal composition constituting the liquid crystal color filter is the same as that of the liquid crystal composition of the present invention described above.

The liquid crystal color filter of the present invention is, for example,
The liquid crystal composition of the present invention can be suitably manufactured. The method for producing the liquid crystal color filter is not particularly limited. For example, a step of imagewise exposing with a first light and patterning, followed by photopolymerization and curing with a second light (hereinafter, referred to as “ The exposure method may be at least one step. In addition, a step of appropriately subjecting the liquid crystal composition to a contact surface with an alignment treatment (alignment treatment step), a step of transferring and forming a liquid crystal layer by adhesion / peeling (transfer step), and a cholesteric liquid crystal composition according to a selected production mode. May be formed through a step of applying a liquid crystal layer to form a liquid crystal layer (coating step).

Hereinafter, a specific embodiment using a cholesteric liquid crystal composition will be described as an example of the manufacturing method including the above-mentioned exposure step. -Exposure Step- In the exposure step, both patterning and fixing (polymerization curing) of the liquid crystal compound are performed by light irradiation. That is, after the photoreactive chiral agent is imagewise exposed and patterned by the first light having a wavelength sensitive to the high sensitivity, the polymerization initiator is photopolymerized by the second light sensitive to the high sensitivity. After curing, the helical structure of the liquid crystal compound is fixed to a desired selective reflection color.

When the liquid crystal composition is irradiated with the first light, the coexisting photoreactive chiral agent responds to the illuminance to change the helical structure of the liquid crystal compound. An image-like pattern is formed showing the reflection color. Therefore, if light irradiation is performed while changing the irradiation intensity for each desired region, a plurality of colors are presented in accordance with the irradiation intensity, for example, exposure is performed through an exposure mask created by changing the light transmittance like an image. Thus, an image, that is, a colored region having different selective reflection can be simultaneously formed by one light irradiation. Further, a liquid crystal color filter can be manufactured by irradiating second light and curing (fixing) the second light.

The wavelength of the first light is preferably set in the light-sensitive wavelength region of the photoreactive chiral agent, particularly in a wavelength close to the light-sensitive peak wavelength, in that sufficient patterning sensitivity can be obtained. Further, it is preferable that the wavelength of the second light be set in a light-sensitive wavelength range of the polymerization initiator, in particular, a wavelength close to the light-sensitive peak wavelength, in that sufficient photopolymerization sensitivity can be obtained. The illuminance (irradiation intensity) of the first and second lights is not particularly limited, and can be appropriately selected depending on the material to be used so that sufficient photosensitivity can be obtained during patterning and polymerization curing. As the light source used for the irradiation of the first and second lights, the same light sources as those usable for the light irradiation of the liquid crystal composition can be used.

More specifically, the manufacturing method according to the following first and second embodiments may be used, and the manufacturing method can be more suitably performed according to these two embodiments. [First Embodiment] (1) A step of providing a liquid crystal composition in a coating liquid state on a temporary support to form a transfer material having at least a liquid crystal layer. The liquid crystal composition in the coating liquid can be prepared by dissolving and dispersing each component in an appropriate solvent. Here, as the solvent,
For example, 2-butanone, cyclohexanone, methylene chloride, chloroform and the like can be mentioned. In producing a liquid crystal color filter, a cholesteric liquid crystal composition is preferable. Between the liquid crystal layer and the temporary support, a cushion layer containing a thermoplastic resin or the like may be provided from the viewpoint of ensuring adhesion during transfer, such as when there is a foreign substance or the like on the transfer target. It is also preferable that the surface of the cushion layer or the like is subjected to an orientation treatment (orientation treatment step) such as a rubbing treatment. (2) a step of laminating the transfer material on a light transmissive substrate; In addition to the light transmitting substrate, an image receiving material having an image receiving layer on a base may be used. Further, the liquid crystal composition may be applied directly on the substrate without using the transfer material (application step). Coating can be performed by appropriately selecting from known coating methods. However, the transfer method is preferable in terms of material loss and cost.

(3) A step of peeling the transfer material from the light-transmitting substrate to form a cholesteric liquid crystal layer on the substrate (transfer step). The liquid crystal layer may be formed of a plurality of layers by further laminating after the following (4). (4) the cholesteric liquid crystal layer via the exposure mask is irradiated with ultraviolet illuminance [nu ¹ imagewise to form a pixel pattern illustrating the selectively reflected color, this further curing the layer by irradiation with ultraviolet illuminance [nu ² Step (exposure step).

[Second Aspect] (1) A step of providing a liquid crystal composition directly on a support constituting a color filter to form a liquid crystal layer. Here, the liquid crystal layer can be formed by applying a liquid crystal composition prepared as a coating liquid in the same manner as described above by a known coating method using a bar coater, a spin coater, or the like. Further, an alignment film similar to the above may be formed between the cholesteric liquid crystal layer and the temporary support. The surface of the alignment film or the like is preferably subjected to an alignment treatment (alignment treatment step) such as a rubbing treatment. (2) An exposure step similar to step (4) of the first embodiment.

The thickness of the liquid crystal layer (sheet-like liquid crystal composition) functioning as a liquid crystal color filter is 1.5 to 5
μm is preferred.

Further description is made below with reference to FIGS. 1 to 3 are schematic views showing one embodiment of a process for manufacturing a liquid crystal color filter of the present invention. First, the components described above are dissolved in an appropriate solvent to prepare a coating liquid cholesteric liquid crystal composition. Here, each component and solvent are as described above.

As shown in FIG. 1- (A), a support 10 (hereinafter also referred to as a “temporary support”) is prepared, and an acrylic resin, polyester, polyurethane, or the like is applied and formed on the support 10. Cushion layer (thermoplastic resin layer) 12
And an alignment film 1 made of polyvinyl alcohol or the like.
4 is laminated. A rubbing process is performed on this alignment film as shown in FIG. This rubbing treatment is not always necessary, but the rubbing treatment can further improve the orientation. Next, FIG.
As shown in (C), a coating liquid cholesteric liquid crystal composition is applied on the alignment film 14 and dried to form a cholesteric liquid crystal layer 16, and then a cover film 18 is provided on the cholesteric liquid crystal layer 16, Create a transfer material. Hereinafter, the transfer material is referred to as a transfer sheet 20.

On the other hand, as shown in FIG. 1- (D), another support 22 is prepared, an alignment film 24 is formed on the support in the same manner as described above, and the surface is rubbed. Hereinafter, this is referred to as a color filter substrate 26.

Next, after the cover film 18 of the transfer sheet 20 is peeled off, as shown in FIG. 2E, the surface of the cholesteric liquid crystal layer 16 of the transfer sheet 20 and the alignment film 24 of the color filter substrate 26 are formed. Are laminated so that they come into contact with the surface of each other, and laminated through a roll rotating in the direction of the arrow in the figure. Thereafter, as shown in FIG. 2F, the alignment film 14 of the transfer sheet 20 and the cushion layer 1 are formed.
2 and the cholesteric liquid crystal layer is transferred together with the alignment film 14 on the color filter substrate. In this case, the cushion layer 12 does not necessarily have to be peeled off together with the temporary support 10.

After the transfer, as shown in FIG. 3G, an exposure mask 28 having a plurality of regions having different light transmittances is disposed above the alignment film 14, and the first mask 28 is provided through the mask 28. The cholesteric liquid crystal layer 16 is irradiated with light in a pattern. The cholesteric liquid crystal layer 16 contains a liquid crystal compound, a chiral compound, or the like so that the helical pitch varies depending on the amount of light irradiation, and a structure having a different helical pitch reflects, for example, green (G) for each pattern. Blue (B)
And a region transmitting red (R), reflecting blue (B), a region transmitting green (G) and red (R), reflecting red (R), and forming green (G) and blue (B). It is formed so as to form an area to be transmitted.

Next, as shown in FIG. 3H, the cholesteric liquid crystal layer 16 is further irradiated with ultraviolet rays at an irradiation intensity different from the light irradiation in the step (G) to fix the pattern. Thereafter, unnecessary portions (for example, remaining portions of the cholesteric liquid crystal layer 16 such as a remaining portion such as a cushion layer and an intermediate layer and unexposed portions) are removed by using 2-butanone, chloroform, or the like, so that the structure shown in FIG. As shown, a cholesteric liquid crystal layer having a BGR reflection region can be formed.

The method shown in FIGS. 1 to 3 is an embodiment of a method for manufacturing a color filter by a lamination method, but may be a method by a coating method in which a liquid crystal layer is directly formed on a color filter substrate. . In this case, when applied to the above embodiment, a cholesteric liquid crystal layer is applied on the alignment film 24 of the color filter substrate 26 shown in FIG. 1- (D), dried, and then similar to FIGS. The steps shown in ()) are sequentially performed.

These steps and materials to be used, such as a transfer material and a support, are described in Japanese Patent Application Nos. 11-342896 and 11-343665 filed by the present inventors.
The details are described in each specification of the item.

As described above, when the liquid crystal composition containing the photoreactive chiral agent represented by the general formula (I) is used, the rate of change of the twisting force of the helical structure of the liquid crystal with respect to the amount of light is large.
The color width of the selective reflection color that can be exhibited by the liquid crystal is expanded, and a liquid crystal color filter having three primary colors of blue (B), green (G), and red (R) excellent in color purity can be obtained.

<Optical Film> The optical film of the present invention contains at least one selected from the photoreactive chiral agents of the present invention, and further contains at least one liquid crystal compound (preferably a nematic liquid crystal compound). Is preferable, and the optical wavelength is arbitrarily set from a wide wavelength range. The liquid crystal composition of the present invention further includes a polymerizable monomer, a photopolymerization initiator, and a surfactant having an excluded volume effect, if necessary, and the like. It can be manufactured by irradiating light with a desired pattern and light amount appropriately selected based on "a method of changing a twist structure".

The optical film of the present invention is prepared by appropriately selecting from the liquid crystal composition of the present invention described above and a known composition containing the compound represented by the general formula (I). Can be. As the form of the optical film,
There is no particular limitation, and any of a sheet form composed of only the liquid crystal composition, a form in which a layer containing a liquid crystal composition (a liquid crystal layer) is provided on a desired support or a temporary support, or the like may be used.
Further, another layer (film) such as an alignment film or a protective film may be provided.

As the liquid crystal compound, polymerizable monomer, photopolymerization initiator and other components, the same compounds as those usable in the liquid crystal composition of the present invention can be used. It is the same as in the case of objects. Further, the content of the compound represented by the general formula (I) in the liquid crystal composition constituting the optical film is the same as that of the liquid crystal composition of the present invention described above.

The optical film of the present invention can be suitably produced by using, for example, the liquid crystal composition of the present invention. In addition, as a method for producing an optical film, it can be produced by a method substantially similar to the liquid crystal color filter,
The method may include at least one exposure step. Further, depending on the manufacturing mode to be selected, it may be formed through steps such as the alignment treatment step, the transfer step, and the coating step. More specifically, it can also be manufactured in substantially the same manner as the manufacturing method of the first embodiment or the second embodiment.

As described above, when the liquid crystal composition containing the photoreactive chiral agent represented by the general formula (I) is used, the rate of change of the twisting force of the helical structure of the liquid crystal with respect to the amount of light can be greatly changed. Thus, a non-light-absorbing optical film can be obtained. For example, when the liquid crystal phase is a cholesteric liquid crystal phase, the color width of the liquid crystal that selectively reflects is widened, an optical film composed of various selective reflection colors, and an optical film of primary colors (B, G, R) with excellent color purity. A film or the like can be obtained.

<Recording Medium> The recording medium of the present invention contains at least one selected from the photoreactive chiral agents of the present invention, and further contains at least one liquid crystal compound (preferably a nematic liquid crystal compound). Is preferable. The liquid crystal composition of the present invention may further contain, if necessary, other components listed in the liquid crystal composition of the present invention, such as a polymerizable monomer, a photopolymerization initiator, and a surfactant having an excluded volume effect.

The recording medium of the present invention is not limited in its form, and may be in the form of a sheet comprising only a liquid crystal composition, or may have a desired support or temporary support (hereinafter referred to as “support etc.”). ) May be provided with a layer (liquid crystal layer) containing a liquid crystal composition containing a photoreactive chiral agent. Here, as the liquid crystal composition, the liquid crystal composition of the present invention described above and a known composition may be replaced by the general formula (I)
Can be appropriately selected from those containing the compound represented by Further, another layer (film) such as an alignment film or a protective film may be provided.

As the liquid crystal compound, polymerizable monomer, photopolymerization initiator and other components, the same compounds as those usable in the liquid crystal composition can be used, and the contents thereof are the same as those of the liquid crystal composition. The same is true. Further, the content of the compound represented by the general formula (I) in the liquid crystal composition constituting the recording medium is the same as that of the liquid crystal composition of the present invention described above.

The recording medium of the present invention can be suitably prepared, for example, by providing the above-mentioned liquid crystal composition of the present invention on a support or the like. The method of providing the liquid crystal composition on a support or the like includes (1) using a transfer material in which a liquid crystal layer containing the liquid crystal composition of the present invention is provided on a temporary support, and then forming the liquid crystal layer on the support. Transfer method, (2) on a support,
A method of directly applying a liquid crystal composition prepared in a coating liquid state,
And the like. In the methods (1) and (2),
With respect to the transfer material and the method of coating, the embodiments exemplified in the liquid crystal composition of the present invention (first and second embodiments)
It can be applied according to the description of FIGS.

The recording medium of the present invention manufactured as described above is irradiated with light in a desired pattern and light amount appropriately selected, so that an image, particularly a cholesteric liquid crystal, can be formed in accordance with the change rate of the twisting force of the liquid crystal. In the case of (1), a colored image composed of selective reflection colors determined by the change rate of the helical pitch can be formed. The image may be formed based on, for example, the above-described “method of changing the helical structure of liquid crystal” and “method of fixing the helical structure of liquid crystal”.

Moreover, when the photoreactive chiral agent represented by the general formula (I) is used as the chiral agent for changing the liquid crystal structure, the rate of change of the twisting force of the helical structure of the liquid crystal with respect to the amount of light is large. An image with a wide range can be formed, and in particular, in the case of a cholesteric liquid crystal, the hue width at which the liquid crystal is selectively reflected can be expanded, and a multicolor image with high color purity can be formed. Further, a large rate of change in the torsional force greatly contributes to higher sensitivity (higher speed) during image formation. Further, for example, by using a polymerizable liquid crystal compound or a polymerizable monomer, the liquid crystal after patterning can be fixed, and an image having sufficient image stability can be formed.

As the light source for irradiating light, the same light sources as those usable in the liquid crystal composition of the present invention can be suitably used for optical recording. The same applies to the case of light irradiation for fixing the liquid crystal.

As described above, chiral agents that change the helical structure of liquid crystal molecules are particularly useful as compounds of the above general formula (I)
By using the photoreactive chiral agent represented by the following formula, the twisting force (twisting angle) of the liquid crystal can be greatly changed. In particular, in the case of a cholesteric liquid crystal using a nematic liquid crystal compound, the selective reflection wavelength range obtained by light irradiation is expanded, and as a result, the color purity of the three primary colors of BGR can be further increased. Therefore, the selectivity and vividness of the hue of the liquid crystal are improved, and particularly in the case of a liquid crystal color filter or an optical film, a clear and vivid color image can be displayed. Can be

[0106]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. still,
“Parts” and “%” in the examples all represent “parts by mass” and “% by mass”.

(Example 1): Measurement of change in helical pitch due to light irradiation Synthesis method described above (synthesis of photoreactive chiral agent (2))
2 parts of the photoreactive chiral agent (exemplified compound (2)) of the present invention synthesized according to the method described above, using a nematic liquid crystal composition (ZLI-11).
Wedge-type cell (glass thickness: 1.32, manufactured by Merck & Co., Ltd.) mixed with 98 parts and subjected to a uniaxial orientation treatment with a polyimide orientation film.
1 mm, blue plate). Here, when the helical pitch at room temperature was measured using a polarizing microscope, it was 1.14 μm.
m. This is the helical twisting power (H
Converted to TP), it is 44 μm ⁻¹ .

Next, the above wedge-shaped cell was irradiated with ultraviolet rays from a high-pressure mercury lamp at an irradiation intensity of 300 mW / cm ² for 3 minutes. After irradiation, the helical pitch at room temperature was measured in the same manner as described above, and it was found to be 3.6 μm. This is 14 μm ⁻¹ when converted to HTP. Therefore, the HTP change rate was 3.14. As described above,
The helical twisting power (HTP) was able to be greatly changed by the irradiation of ultraviolet rays. In addition, when the direction of the twist before and after the ultraviolet irradiation was confirmed by the contact method, it was found that the twist was right before and after the irradiation.

Example 2 Preparation of Broadband Circularly Polarized Reflector (1) Preparation of Substrate A polyimide alignment film (LX-1400,
After applying a coating solution with a spin coater and drying in an oven at 100 ° C. for 5 minutes,
The alignment film was formed by firing in an oven at 250 ° C. for 1 hour. Further, the surface of the film was subjected to an orientation treatment by a rubbing treatment to produce a glass substrate with an orientation film.

(2) Preparation A coating solution prepared according to the following formulation was applied on the alignment film of the glass substrate provided with the alignment film obtained above using a bar coater.
After being kept on a hot plate at 110 ° C. for 5 minutes, light irradiation was performed for 5 minutes with an ultra-high pressure mercury lamp at this temperature through a band-pass filter having a light source center wavelength of 365 nm. The following photoreactive chiral agent (exemplified compound (3)) of the present invention was synthesized by a method similar to the above-described synthesis method.

Next, the sample was kept in a dark place for 5 minutes while maintaining the temperature at 110 ° C., and then the band pass filter was removed.
The entire surface was further exposed to light at an irradiation energy of 500 mJ / cm ² by the same ultra-high pressure mercury lamp as described above while blowing nitrogen gas, and polymerized and cured. As described above, a circularly polarized light reflecting plate was produced.

[0112]

Embedded image

The circularly-polarized light reflecting plate obtained above was 450 to 6
It exhibited selective reflection in a wide wavelength range over 30 nm, and had sufficient band characteristics as a broadband circularly polarized light reflecting plate. Moreover, the right circularly polarized light reflectance at a selective reflection wavelength of 550 nm was 98%.

(Example 3): Preparation of liquid crystal color filter (1) Preparation of filter substrate A polyimide alignment film (LX-1400, manufactured by Hitachi Chemical DuPont) was applied on a glass substrate by a spin coater. After drying in an oven at 100 ° C for 5 minutes, 2
It was baked in an oven at 50 ° C. for 1 hour to form an alignment film.
Further, the surface of the film was subjected to an orientation treatment by a rubbing treatment to produce a glass substrate with an orientation film.

(2) Formation of Filter Layer On the alignment film of the glass substrate provided with an alignment film obtained above, a coating solution for a photosensitive resin layer prepared according to the following formulation was applied by a spin coater, and this was applied at 110 ° C. For 2 minutes to form a photosensitive resin layer. The following photoreactive chiral agent of the present invention (exemplified compound (2)) was synthesized according to the synthesis method described above.

[0116]

Embedded image

Then, the photosensitive resin layer was held on a hot plate at 110 ° C. for 5 minutes so that the photosensitive resin layer was in contact with the surface of the glass substrate to develop a color. Further, on the photosensitive resin layer, the transmittance is different in three stages (0%, 46%, 92%), and the respective regions are arranged corresponding to blue pixels, green pixels, and red pixels. An ultra-high pressure mercury lamp is arranged via a photomask and a bandpass filter centered at 365 nm,
Irradiation was performed with an ultra-high pressure mercury lamp through this photomask and bandpass filter to perform patterning. The irradiation energy at this time was 300 mJ / cm ² for the red pixel.
And the irradiation intensity was 30 mW / cm ² .

Next, the photomask and the band-pass filter were removed, and the irradiation energy was 500 mJ / cm ² by the same ultra-high pressure mercury lamp while blowing nitrogen gas.
Then, the entire surface was exposed and polymerized and cured. Furthermore, in order to promote the degree of curing of the filter portion (photosensitive resin layer), the
For 20 minutes to obtain a color filter on which red, green, and blue pixel patterns were formed. At the time of the above patterning, the helical pitch of the liquid crystal (torsion force of the liquid crystal) can be largely changed by irradiation,
A pixel pattern composed of red, green, and blue with high color purity could be formed.

Example 4 Preparation of Optical Compensation Film for STN Element A polyethylene vinyl alcohol (PVA) film having a saponification degree of 99.5% was formed on a 80 μm-thick triacetyl cellulose (TAC) by a bar coating method. And 110 ° C
Heated under for 3 minutes. A rubbing treatment was performed on the PVA film, and a coating solution prepared according to the following formulation was further heated and applied by a bar coater, and dried in an oven at 120 ° C. for 3 minutes to form a film. The following photoreactive chiral agent of the present invention (exemplified compound (5)) was synthesized according to the synthesis method described above.

[0120]

Embedded image

Next, at a temperature of 100 ° C., ultraviolet irradiation (irradiation energy 1) was performed from above the film using a high-pressure mercury lamp.
2,000 mJ / cm ² ) to polymerize and cure the film.
An optical compensation film for an N element was manufactured (hereinafter, referred to as “STN compensation film”). When the film thickness of the STN compensation film at this time was measured, it was 5.0 μm. In addition, from the polarization transmission spectrum profile of the STN compensation film, it was found that the orientation (spiral structure) of the liquid crystal molecules was twisted in the film thickness direction at 240 degrees, and the twist angle (rotation angle) of the spiral was 240 degrees. Also, an STN compensation film having a twist angle (-240 degrees) opposite to that of the film is prepared, and these films are overlapped so that the liquid crystal molecules in the matched portion are orthogonal to each other, and the absorption axes are orthogonal to each other. It was inserted between two polarizing plates and visually observed, and showed a good black color. Therefore, it was confirmed that the film (STN compensation film) formed as described above functions as an optical compensation film for an STN element.

Example 5: Prevention of generation of reverse twist domain for TN element A polyimide alignment film (LX-1400, Hitachi Chemical DuPont, Ltd.) was formed on the ITO film of the glass substrate with the ITO film.
Coating solution was applied by a spin coater, dried in an oven at 100 ° C for 5 minutes, and then dried in an oven at 250 ° C.
After firing for an hour, an alignment film was formed. Further, a rubbing treatment was performed on the surface of the film to perform an orientation treatment so that the rubbing angle was 90 degrees, thereby producing two glass substrates with an orientation film. The above-mentioned glass substrates with an alignment film were arranged so that the alignment films face each other, and bonded together with a two-liquid epoxy resin adhesive mixed with spacer beads having a diameter of 6 μm to form a driving cell. When the thickness of the cell was measured by an optical interference method, it was 5.4 μm.

A composition having the following composition was injected into the cell. The following photoreactive chiral agent of the present invention (exemplified compound (2)) was synthesized according to the synthesis method described above. [Composition]-Nematic liquid crystal composition (ZLI-1132, manufactured by Merck): 99.9%-Photoreactive chiral agent of the present invention (exemplified compound (2) described above) ... 0.1 %

Next, when the driving cell after injection was inserted between two polarizing plates whose absorption axes were orthogonal to each other and observed visually, no generation of a reverse twist domain was observed. Therefore, there is no reduction in contrast due to the occurrence of reverse twist, and an image display excellent in contrast and color purity can be expected.

[0125]

According to the present invention, the orientation of the liquid crystal compound can be controlled, and the rate of change of the twisting force (twist angle, helical pitch) of the liquid crystal by light (hereinafter referred to as the "twist change rate"). .), For example, in the case of a cholesteric liquid crystal phase, a wide range of selective reflection including the three primary colors (B, G, R) is possible, and a photoreactive chiral agent capable of displaying three primary colors with high color purity is provided. can do. According to the present invention, the twisting force of the liquid crystal is changed by light, and a light-reactive chiral agent having a large rate of change in twist is included. In the case of a liquid crystal composition which can be used, for example, a cholesteric liquid crystal, it is possible to provide a liquid crystal composition which exhibits a wide range of selective reflection colors including three primary colors by light irradiation, and is capable of displaying three primary colors with excellent color purity. it can. According to the present invention, there is provided a method of changing the twisted structure of a liquid crystal, in which a liquid crystal composition containing a photoreactive chiral agent having a large twist change rate can be irradiated with light to greatly change the twisting force (twist angle) of the liquid crystal. can do. According to the present invention, it is possible to provide a liquid crystal color filter having high color purity, which includes a photoreactive chiral agent capable of greatly changing the twisting force of liquid crystal by light irradiation. According to the present invention, in the case of a non-light-absorbing optical film containing a photoreactive chiral agent capable of greatly changing the torsional force of liquid crystal by light irradiation, for example, in the case of a cholesteric liquid crystal phase, the selective reflection range is wide and color purity is wide. Optical film having a high level can be provided. According to the present invention, a recording medium that contains a photoreactive chiral agent that can greatly change the twisting force of liquid crystal by light irradiation and that can form a clear image by changing the amount of light imagewise, for example, the liquid crystal phase is cholesteric In the case of a liquid crystal phase, it is possible to provide a recording medium capable of forming an image composed of a selective reflection color having a wide hue and a high color purity.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a part of a process of manufacturing a liquid crystal color filter of the present invention.

FIG. 2 is a schematic view showing a part of a process of manufacturing a liquid crystal color filter of the present invention.

FIG. 3 is a schematic view showing a part of a process of manufacturing a liquid crystal color filter of the present invention.

[Explanation of symbols]

 Reference Signs List 10 support (temporary support) 12 cushion layer (thermoplastic resin layer) 14, 24 alignment film 16 liquid crystal layer (liquid crystal composition) 18 cover film 20 transfer sheet 22 substrate 26 substrate for color filter 28 exposure mask

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02F 1/13 102 G02F 1/13 102 500 500 1/139 1/137 505 (72) Inventor Keiichiro Hayashi Shizuoka 200, Onakazato, Fujinomiya-shi, Fuji Fuji Photo Film Co., Ltd. F-term (reference) 2H048 AA06 AA12 AA18 BA43 BA47 BA48 BB02 BB42 2H088 EA02 EA62 GA02 GA03 GA17 JA05 KA11 MA04 MA05 MA06 MA07 4C071 AA01 BB01 CC05 4H027 BA02 BA13 BD20 BD21 DH01 DH03

Claims (8)

[Claims] 1. A photoreactive chiral agent comprising a compound represented by the following general formula (I), wherein the chirality of a liquid crystal is changed by light irradiation. Embedded image [In the formula, R represents a hydrogen atom, an alkoxy group having 1 to 15 carbon atoms, an acryloyloxyalkyloxy group having 3 to 15 carbon atoms, or a methacryloyloxyalkyloxy group having 4 to 15 carbon atoms. ] 2. The compound represented by the general formula (I), wherein R is an acryloyloxyalkyloxy group having a total of 3 to 15 carbon atoms or a methacryloyloxyalkyloxy group having a total of 4 to 15 carbon atoms. 2. The photoreactive chiral agent according to item 1. 3. The photoreactive chiral agent according to claim 1, wherein in the compound represented by the general formula (I), R is a hydrogen atom or an alkoxy group having 1 to 15 carbon atoms. 4. A liquid crystal composition comprising at least one selected from the photoreactive chiral agents according to claim 1. 5. A method for changing the twisted structure of a liquid crystal, comprising irradiating the liquid crystal composition according to claim 4 with light to change the twisting force of the liquid crystal. 6. A liquid crystal color filter comprising at least one selected from the photoreactive chiral agents according to claim 1. Description: 7. An optical film comprising at least one selected from the photoreactive chiral agents according to claim 1. 8. A recording medium comprising at least one selected from the photoreactive chiral agents according to claim 1.