WO2019189444A1

WO2019189444A1 - Liquid-crystal material, liquid-crystal film, method for producing same, sensor, and optical element

Info

Publication number: WO2019189444A1
Application number: PCT/JP2019/013328
Authority: WO
Inventors: 古海　誓一; 将司府川; 鈴木　達也; 花菜鈴木; 健一郎早田
Original assignee: 学校法人東京理科大学
Priority date: 2018-03-28
Filing date: 2019-03-27
Publication date: 2019-10-03
Also published as: JPWO2019189444A1; JP7296134B2

Abstract

A liquid-crystal material containing a cellulose derivative having a molecular structure represented by general formula (1A). In general formula (1A), X¹¹, X¹², and X¹³ each independently represent a single bond, an alkylene group, -(R¹⁴-O)_h-, or-C(=O)-R¹⁵-; R¹¹, R¹², and R¹³ each independently represent a hydrogen atom, a group having an unsaturated double bond, or a hydrophobic group; R¹⁴ and R¹⁵ each independently represent an alkylene group; h represents an integer of 1-10; and n11 represents an integer of 2-800. However, at least one of R¹¹, R¹², and R¹³ represents a group having an unsaturated double bond represented by general formula (3C) and/or a C5-20 linear or branched acyl group.

Description

Liquid crystal material, liquid crystal film and manufacturing method thereof, sensor, and optical element

The present invention relates to a liquid crystal material, a liquid crystal film, a manufacturing method thereof, a sensor, and an optical element.

Liquid crystal materials are not only used as display materials for liquid crystal displays, but in recent years, application to photonic devices has been promoted using their optical characteristics. As a liquid crystal material, for example, a cellulose derivative is known.

As a cellulose derivative having liquid crystallinity, a cellulose derivative in which a substituent having a carbamate group (urethane bond) is introduced into a hydrogen atom of a hydroxyl group of hydroxypropyl cellulose is disclosed (for example, see Patent Document 1).

Step (I) of mixing a solvent (A), a cellulose derivative (B) capable of forming a liquid crystal in the solvent (A), and a tetraalkoxysilane (C) to obtain a mixed solution, the cellulose derivative ( A step (II) of obtaining a composite material of the liquid crystallized product of B) and a condensate of the tetraalkoxysilane (C), and a step of removing the liquid crystallized product in the composite material by treatment with acid (E) (III ) Has been disclosed (for example, see Patent Document 2).

Japanese Patent Laying-Open No. 2015-48365 JP 2016-113315 A

Patent Document 1 describes a methacryloyl group as a group that can be introduced into a side chain of a cellulose derivative, but it is not introduced for crosslinking between monomer units of the cellulose derivative. Furthermore, Patent Document 1 does not plan to impart elasticity to the crosslinked cellulose derivative.

The liquid crystal described in Patent Document 2 is finally removed by acid treatment. Therefore, the silica-based chiral structure does not utilize the liquid crystallinity and optical properties of cellulose.

Hydroxypropylcellulose (HPC) is a cellulose derivative that is the main component of paper, cotton, and pulp, and is harmless to the human body and the environment. It is a polymer. Cellulose is an inexpensive material because it is the most abundant raw material in nature.
Therefore, the development of liquid crystal materials and the like using cellulose derivatives as raw materials is also useful from the viewpoint of safety and the reduction of environmental burden. Further, it is expected to be used for photonic devices.

The present invention has been made in view of the above circumstances, and exhibits a thermotropic cholesteric liquid crystallinity and rubber elasticity, and a liquid crystal material, a liquid crystal film, and a liquid crystal material having a large shift change in the wavelength of reflected light with respect to mechanical pressure It is an object to provide a manufacturing method, a sensor, and an optical element.

As a result of intensive studies, the present inventors have found that a liquid crystal material containing a cellulose derivative having a specific structure exhibits a thermotropic cholesteric liquid crystal property, and has an alkylene group having a specific number of carbon atoms or more at the end of the side chain. A liquid crystal film exhibiting rubber elasticity and containing the liquid crystal material is crosslinked at a wavelength of Bragg reflection by crosslinking a cellulose derivative containing at least one of a group having a saturated double bond and an acyl group having a specific carbon number or more. The inventors have found that the orientation can be fixed and color can be developed, and the present invention has been completed.
That is, the following embodiments are included in the means for solving the problems.
<1> A liquid crystal material containing a cellulose derivative having a molecular structure represented by the following general formula (1A).

(In the general formula (1A), X ¹¹ , X ¹² and X ¹³ are each independently a single bond, an alkylene group, — (R ¹⁴ —O) _h —, or —C (═O) —R ¹⁵ —. R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom, a group having an unsaturated double bond, or a hydrophobic group, and R ¹⁴ and R ¹⁵ each independently represents an alkylene group. H represents an integer of 1 to 10, and n11 represents an integer of 2 to 800, provided that at least one of R ¹¹ , R ¹² and R ¹³ is represented by the following general formula (3C). It represents at least one of the group having an unsaturated double bond and a linear or branched acyl group having 5 to 20 carbon atoms.)

(In the general formula (3C), R ^3C represents a hydrogen atom or a methyl group, and X ³⁸ represents a linear or branched alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O— Represents a group selected from the group consisting of a carbonyl group, a linear or branched alkyleneoxy group having 2 to 20 carbon atoms, an aryl group and a cycloalkylene group having 3 to 10 carbon atoms, or a group obtained by linking at least one of these groups. ** represents a moiety bonded to X ¹¹ , X ¹² , or X ^{13 in the} general formula (1A), or a moiety bonded to an oxygen atom at the 2-position, 3-position, or 6-position of the cellulose skeleton. To express.)
<2> The liquid crystal material according to <1>, wherein the molecular structure represented by the general formula (1A) is a molecular structure represented by the following general formula (1A-1).

In the general formula (1A-1), R ¹ represents —CH ₂ —CH ₂ — or —CH ₂ —CH (CH ₃ ) —, and R ¹¹ , R ¹² and R ¹³ are each independently A hydrogen atom, a group having an unsaturated double bond, or a hydrophobic group, m1, t1 and r1 each independently represents an integer of 0 to 10, and n13 represents an integer of 2 to 800. To express. However, at least one of R ¹¹ , R ¹² and R ¹³ is at least one of a group having an unsaturated double bond represented by the following general formula (3C) and a linear or branched acyl group having 5 to 20 carbon atoms. Represents one.

In the general formula (3C), R ^3C represents a hydrogen atom or a methyl group, X ³⁸ represents a linear or branched alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O—, Represents a group selected from the group consisting of a carbonyl group, a linear or branched alkyleneoxy group having 2 to 20 carbon atoms, an aryl group and a cycloalkylene group having 3 to 10 carbon atoms, or a group obtained by linking at least one of these groups, ** represents a moiety that binds to X ¹¹ , X ¹² , or X ^{13 in the} general formula (1A) or a moiety that binds to an oxygen atom at the 2nd, 3rd, or 6th position of the cellulose skeleton. .
<3> The group having an unsaturated double bond further includes a group represented by the following general formula (1C),
The hydrophobic group is a linear or branched alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, a carbon number A linear or branched acyl group having 2 to 4 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, a carboxylic acid ester group represented by —COOR ^1A , or a halogen atom, wherein R ^1A is a carbon atom The liquid crystal material according to <1> or <2>, further comprising a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms.

In the general formula (1C), R ^1C represents a hydrogen atom or a methyl group, X ¹⁸ represents a single bond, a linear or branched alkylene group having 1 to 18 carbon atoms, a cycloalkylene group having 3 to 18 carbon atoms, An arylene group having 6 to 18 carbon atoms, —O—, —NH—, —S—, —C (═O) —, a group obtained by removing three hydrogen atoms from a linear or branched alkane having 1 to 18 carbon atoms A group obtained by removing three hydrogen atoms from a cycloalkane having 3 to 18 carbon atoms, a group obtained by removing three hydrogen atoms from an arene having 6 to 18 carbon atoms, and a group obtained by removing three hydrogen atoms from ammonia It represents a selected group or a group obtained by linking at least one of them, and p1 represents an integer of 1 or 2. However, the valence of X ¹⁸ is p1 + 1. ** represents a moiety that binds to X ¹¹ , X ¹² , or X ^{13 in the} general formula (1A) or a moiety that binds to an oxygen atom at the 2nd, 3rd, or 6th position of the cellulose skeleton. .
<4> In the general formula (1C), X ¹⁸ is a single bond or —C (═O) —NH— (CH ₂ ) ₂ —O—, p1 is 1, <3> The liquid crystal material described.
<5> The liquid crystal material according to <3> or <4>, wherein the hydrophobic group is a linear or branched acyl group having 2 to 4 carbon atoms.
<6> The liquid crystal material according to any one of <1> to <5>, wherein the degree of substitution per monomer unit of the group having an unsaturated double bond is 0.01 or more and 2.0 or less.
<7> Ratio of the degree of substitution per monomer unit of the group having an unsaturated double bond to the degree of substitution per monomer unit of the hydrophobic group (the group having an unsaturated double bond / the hydrophobic group ) Is 3.0 × 10 ⁻³ or more and 2.0 or less, the liquid crystal material according to any one of <1> to <6>.
<8> Has a three-dimensional structure,
Including a cellulose derivative having a molecular structure represented by the following general formula (2A),
The liquid crystal film in which the cellulose derivative includes a group having a group for connecting monomer units to each other.

In the general formula (2A), X ²¹ , X ²² and X ²³ each independently represent a single bond, an alkylene group, — (R ²⁴ —O) _j —, or —C (═O) —R ²⁵ —. R ²¹ , R ²² and R ²³ are each independently a hydrogen atom, a group having a group linking the monomer units, or a hydrophobic group, and R ²⁴ and R ²⁵ are each independently Represents an alkylene group, j represents an integer of 1 to 10, and n21 represents an integer of 2 to 800. However, at least one of R ²¹ , R ²² and R ²³ is at least one of a group connecting monomer units represented by the following general formula (4C) and a linear or branched acyl group having 5 to 20 carbon atoms. Represents.

In the general formula (4C), R ^4C represents a hydrogen atom or a methyl group, X ⁴⁸ represents a linear or branched alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O—, Represents a group selected from the group consisting of a carbonyl group, a linear or branched alkyleneoxy group having 2 to 20 carbon atoms, an aryl group, and a cycloalkylene group having 3 to 10 carbon atoms, or a group obtained by linking these, * represents a monomer ** represents a bonding position when the units are linked to each other, and ** represents a portion bonded to X ²¹ , X ²² , or X ^{23 in the} general formula (2A), or the 2-position, 3-position of the cellulose skeleton, Alternatively, it represents a moiety bonded to the oxygen atom at the 6-position.
<9> The liquid crystal film according to <8>, wherein the degree of substitution per monomer unit of the hydrophobic group is 1.0 or more and 2.9 or less.
<10> The liquid crystal film according to <8> or <9>, wherein the molecular structure represented by the general formula (2A) is a molecular structure represented by the following general formula (2A-1).

In the general formula (2A-1), R ² represents —CH ₂ —CH ₂ — or —CH ₂ —CH (CH ₃ ) —, and R ²¹ , R ²² and R ²³ each independently represent A hydrogen atom, a group having the linking group, or a hydrophobic group is represented, m2, t2 and r2 each independently represent an integer of 0 to 10, and n23 represents an integer of 2 to 800. However, at least one of R ²¹ , R ²² and R ²³ is at least one of a group connecting monomer units represented by the following general formula (4C) and a linear or branched acyl group having 5 to 20 carbon atoms. Represents.

In the general formula (4C), R ^4C represents a hydrogen atom or a methyl group, X ⁴⁸ represents a linear or branched alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O—, Represents a group selected from the group consisting of a carbonyl group, a linear or branched alkyleneoxy group having 2 to 20 carbon atoms, an aryl group, and a cycloalkylene group having 3 to 10 carbon atoms, or a group obtained by linking these, * represents a monomer ** represents a bonding position when the units are linked to each other, and ** represents a portion bonded to X ²¹ , X ²² , or X ^{23 in the} general formula (2A), or the 2-position, 3-position of the cellulose skeleton, Alternatively, it represents a moiety bonded to the oxygen atom at the 6-position.
<11> The group connecting the monomer units includes a group represented by the following general formula (2C),
The hydrophobic group is a linear or branched alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, a carbon number A linear or branched acyl group having 2 to 4 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, a carboxylic acid ester group represented by —COOR ^2A , or a halogen atom, wherein R ^2A is carbon <8> to <10>, which includes a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Liquid crystal film.

(In the general formula (2C), R ^2C represents a hydrogen atom or a methyl group, X ²⁸ represents a single bond, a linear or branched alkylene group having 1 to 18 carbon atoms, or a cycloalkylene group having 3 to 18 carbon atoms. Three hydrogen atoms were removed from an arylene group having 6 to 18 carbon atoms, —O—, —NH—, —S—, —C (═O) —, or a linear or branched alkane having 1 to 18 carbon atoms. A group consisting of a group obtained by removing 3 hydrogen atoms from a cycloalkane having 3 to 18 carbon atoms, a group obtained by removing 3 hydrogen atoms from an arene having 6 to 18 carbon atoms, and a group obtained by removing 3 hydrogen atoms from ammonia Represents a group selected from the above or a group obtained by linking them, and p2 represents an integer of 1 or 2. However, X ^{28 has} a valence of p2 + 1, * represents a bond when monomer units are linked to each other. ** represents the position in the above general formula (2A) X ^21, ^{X 22,} or a moiety that binds with ^{X 23,} or represents a 2-position, 3-position, or a moiety that binds to be an oxygen atom in the 6-position of the cellulose backbone.)
<12> In the above general formula (2C), X ²⁸ is a single bond or —C (═O) —NH— (CH ₂ ) ₂ —O—, p2 is 1, <11> The liquid crystal film as described.
<13> The liquid crystal film according to <11> or <12>, wherein the hydrophobic group is a linear or branched acyl group having 2 to 4 carbon atoms.
<14> a step of applying the liquid crystal material according to any one of <1> to <7> on a substrate;
A step of applying heat or irradiating ultraviolet rays to the liquid crystal material applied on the substrate;
A method for producing a liquid crystal film, comprising:
<15> A sensor comprising the liquid crystal film according to any one of <8> to <13>.
<16> The sensor according to <15>, which is a distortion sensor that detects distortion of an object.
<17> The sensor according to <16>, which is a wearable sensor that detects biological information.
<18> An optical element comprising the liquid crystal film according to any one of <8> to <13>.

According to the present invention, there are provided a liquid crystal material, a liquid crystal film, a method for manufacturing the same, a sensor, and an optical element that exhibit thermotropic cholesteric liquid crystallinity and rubber elasticity, and that have a large wavelength shift change of reflected light with respect to mechanical pressure. can do.

In this embodiment, it is the schematic which shows an example of the method of manufacturing the liquid crystal film by which orientation was fixed by the wavelength of different Bragg reflection. (A) is a liquid crystal cell after heating at a first temperature, and (B) is a liquid crystal cell after heating at a second temperature. FIG. 2 is a diagram showing the complex viscosity, the storage elastic modulus, and the loss elastic modulus with respect to the angular frequency of the liquid crystal materials 1-1 to 1-3. FIG. 3 is a plot of loss tangent versus angular frequency of the liquid crystal materials 1-1 to 1-3. FIG. 4 is a diagram of the ¹ H-NMR spectrum of hydroxypropylcellulose derivative 1 synthesized in Example 2-1. FIG. 5 is a diagram showing an FT-IR spectrum of Example 2-1. FIG. 6 is a graph showing a change in transmission spectrum when mechanical pressure is applied to the liquid crystal film 2-1 fixed at 30 ° C. FIG. 7 is a diagram showing the change in the transmission spectrum when mechanical pressure is applied to the liquid crystal film 2-2 fixed at 40 ° C. FIG. 8 is a diagram showing a change in the transmission spectrum when mechanical pressure is applied to the liquid crystal film 2-3 fixed at 60 ° C. FIG. 9 is a diagram showing a change in transmission spectrum when mechanical pressure is applied to the liquid crystal film 2-4 fixed at 70 ° C. FIG. FIG. 10 shows the wavelength before mechanical pressure is applied to the reduction rate (compression ratio) of the film thickness when mechanical pressure is applied to the liquid crystal films 2-1, 2-2, 2-3, and 2-4. It is the figure which plotted ratio of wavelength (lambda) after applying mechanical pressure with respect to (lambda ₀ ). FIG. 11 is a diagram of the ¹ H-NMR spectrum of hydroxypropylcellulose derivative 1 synthesized in Example 3. FIG. 12 is an FT-IR spectrum of Example 3. FIG. 13 is a diagram showing a change in the transmission spectrum when mechanical pressure is applied to the liquid crystal film 3. FIG. 14 shows the wavelength after applying the mechanical pressure to the wavelength (λ ₀ ) before applying the mechanical pressure, with respect to the reduction rate (compression ratio) of the film thickness when the mechanical pressure is applied to the liquid crystal film 3. It is the figure which plotted ratio of (lambda). FIG. 15 is a diagram illustrating a change in the transmission spectrum when mechanical pressure is applied to the liquid crystal film 4-1. FIG. 16 shows the mechanical pressure relative to the wavelength (λ ₀ ) before applying the mechanical pressure with respect to the reduction rate (compression ratio) of the film thickness when the mechanical pressure is applied to the liquid crystal films 4-1 and 4-2. It is the figure which plotted the ratio of the wavelength ((lambda)) after adding. FIG. 17 is a diagram illustrating a change in the transmission spectrum when mechanical pressure is applied to the liquid crystal film 4-2. FIG. 18 is a diagram illustrating a change in the transmission spectrum when mechanical pressure is applied to the liquid crystal film 5-1. FIG. 19 shows the mechanical pressure relative to the wavelength (λ ₀ ) before the mechanical pressure is applied to the film thickness reduction rate (compression ratio) when the mechanical pressure is applied to the liquid crystal films 5-1 and 5-2. It is the figure which plotted the ratio of the wavelength ((lambda)) after adding. FIG. 20 is a diagram showing the change in the transmission spectrum when mechanical pressure is applied to the liquid crystal film 5-2. FIG. 21 is a diagram showing stress-strain curves in the process of stretching the liquid crystal films 6-1 and 6-2 and the liquid crystal film 7. FIG. 22 is a diagram showing a stress-strain curve of the liquid crystal film 8 when the amount of ultraviolet light to be irradiated is changed when the liquid crystal film 8 is manufactured. FIG. 23 is a diagram showing changes in elastic characteristics when the amount of ultraviolet light (10.8 J / cm ² to 48.6 J / cm ² ) is changed when the liquid crystal film 8 is manufactured. FIG. 24 is a diagram illustrating a change in the transmission spectrum when heat is applied to the liquid crystal film 8. FIG. 25 is a diagram showing the correlation between temperature and Bragg reflection wavelength for the HPC derivative 8 (before crosslinking) and the liquid crystal film 8 (after crosslinking). The upper part of FIG. 26 is a diagram showing a change in transmission spectrum when mechanical pressure is applied to the liquid crystal film 8, and the lower part of FIG. 26 is a transmission spectrum when mechanical pressure applied to the liquid crystal film 8 is released. FIG. FIG. 27 shows transmission spectra when mechanical pressure is applied to the liquid crystal film 8 and when the mechanical pressure applied to the liquid crystal film 8 is released in the first and 100th cycles of applying and releasing the mechanical pressure. FIG. FIG. 28 is a diagram illustrating changes in the reflection wavelength and the liquid crystal film 8 when the cycle of applying and releasing the mechanical pressure is repeated 100 times for the liquid crystal film 8. FIG. 29 is a diagram showing a stress-strain curve when applying and releasing mechanical pressure to the liquid crystal film 8 repeatedly. FIG. 30 is a diagram showing changes in elastic properties when mechanical pressure is repeatedly applied to and released from the liquid crystal film 8 and the chloroprene rubber. FIG. 31 is a diagram illustrating a change in color of the liquid crystal film 8 when the liquid crystal film 8 is pressed against the uneven substrate. FIG. 32 is a diagram illustrating a change in the reflection wavelength of the liquid crystal film 8 when the liquid crystal film 8 is pressed against the uneven substrate. FIG. 33 is a diagram illustrating a change in the color of the liquid crystal film 8 when the liquid crystal film 8 is pressed against the surface of a 100-yen coin. FIG. 34 is a diagram showing the result of measuring the unevenness of a 100-yen coin with a precision instrument. FIG. 35 is a diagram showing a change in transmission spectrum when mechanical pressure is applied to the liquid crystal film 8 and the liquid crystal film 9 and when mechanical pressure applied to the liquid crystal film 8 and the liquid crystal film 9 is released. FIG. 36 is a diagram illustrating the relationship between the reflection wavelength, stress, and strain for the liquid crystal film 8 and the liquid crystal film 9. FIG. 37 is a view of ¹ H-NMR spectrum of 4H synthesized in Example 10-1. FIG. 38 is a chart of ¹ H-NMR spectrum of HPC derivative 10-1 produced in Example 10-1. FIG. 39 is a diagram showing a stress-strain curve in the stretching process of the liquid crystal film 10-1. FIG. 40 is a diagram showing stress-strain curves in the stretching process of the liquid crystal films 10-2, 10-3, and 10-4. FIG. 41 is a transmission spectrum in the stretching release process of the liquid crystal film 10-3.

Hereinafter, the liquid crystal material according to the embodiment of the present invention will be described.
In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In the present specification, the (meth) acryloyl group means at least one of an acryloyl group and a methacryloyl group.

<Liquid crystal material>
The liquid crystal material of the present embodiment includes a cellulose derivative having a molecular structure represented by the following general formula (1A) (hereinafter also referred to as “specific cellulose derivative”).
Since the liquid crystal material of this embodiment contains a specific cellulose derivative, it exhibits thermotropic cholesteric liquid crystallinity and has a large shift change in the wavelength of reflected light with respect to mechanical pressure.
Although this mechanism is not clear, it is presumed as follows.

In the liquid crystal material of this embodiment, the specific cellulose derivative containing at least one of a group having an alkylene group having a specific carbon number or more and an unsaturated double bond and an acyl group having a specific carbon number or more at the end of the side chain Thus, thermotropic cholesteric liquid crystallinity and rubber elasticity are exhibited, and the wavelength shift of reflected light with respect to mechanical pressure is large.
Moreover, the specific cellulose derivative can reduce the viscoelasticity of the liquid crystal material by containing an alkylene group having a specific carbon number or more and a group having an unsaturated double bond at the end of the side chain.
The elastomer film formed from the liquid crystal material of the present embodiment has at least one of a polymerizable monomer containing a group connecting monomer units having an alkylene group having a specific carbon number or more and an acyl group having a specific carbon number or more. In order to reduce viscoelasticity and to show an excellent cholesteric liquid crystal alignment state, it has a structure that is easily affected when mechanical pressure is applied to a liquid crystal film produced by a crosslinking reaction. Yes.
Therefore, when the elastomer film is compressed in the film thickness direction, the wavelength shift to the short wavelength side is large, and the wavelength reflectance is also high.
Hereinafter, each component of the liquid crystal material of the present embodiment will be described in detail.

<Specific cellulose derivative>
The specific cellulose derivative has a molecular structure represented by the following general formula (1A).
In the molecular structure represented by the general formula (1A), [] represents a monomer unit. Hereinafter, [] is also simply referred to as “monomer unit”. The same applies to general formulas other than the general formula (1A).

In the general formula (1A), X ¹¹ , X ¹² and X ¹³ each independently represent a single bond, an alkylene group, — (R ¹⁴ —O) _h —, or —C (═O) —R ¹⁵ —. R ¹¹ , R ¹² and R ¹³ each independently represents a hydrogen atom, a group having an unsaturated double bond or a hydrophobic group, and R ¹⁴ and R ¹⁵ each independently represents an alkylene group. H represents an integer of 1 to 10, and n11 represents an integer of 2 to 800. However, at least one of R ¹¹ , R ¹² and R ¹³ is at least one of a group having an unsaturated double bond represented by the following general formula (3C) and a linear or branched acyl group having 5 to 20 carbon atoms. Represents one.

In general formula (1A), the alkylene group represented by X ¹¹ , X ¹² and X ¹³ is not particularly limited. Examples of the alkylene group include linear or branched alkylene groups having 1 to 18 (preferably 1 to 12) carbon atoms and cyclic cycloalkylene groups having 3 to 18 (preferably 3 to 12) carbon atoms. Examples of the linear or branched alkylene group include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, an isobutylene group, a sec-butylene group, a tert-butylene group, an n-pentylene group, An isopentylene group etc. are mentioned.
Examples of the cyclic alkylene group include a cyclopentylene group and a cyclohexylene group.

In general formula (1A), examples of the alkylene group (—R ¹⁴ —) in the group represented by — (R ¹⁴ —O) _h — include the same alkylene groups as X ¹¹ , X ¹² and X ¹³ above. .
Examples of — (R ¹⁴ —O) _h — include an ethyleneoxy group, a polyethyleneoxy group, a propyleneoxy group, a polypropyleneoxy group, and the like.
More specifically, — (R ¹⁴ —O) _h — can be represented by — (— O— (CH ₂ ) n—) _h —. However, n is an integer of 1 to 5.

In the general formula (1A), h is preferably 1 or more and 6 or less, more preferably 1 or more and 4 or less, and further preferably 1 or more and 3 or less from the viewpoint of obtaining a liquid crystal film having appropriate rubber elasticity by crosslinking. .

In general formula (1A), examples of the alkylene group (—R ¹⁵ —) in the group represented by —C (═O) —R ¹⁵ — include the same alkylene groups as X ¹¹ , X ¹² and X ¹³ above. It is done.
Examples of —C (═O) —R ¹⁵ — include —C (═O) —CH ₂ —, —C (═O) —C ₂ H ₄ —, —C (═O) —C ₃ H _6. -Etc. are mentioned.

The alkylene group, — (R ¹⁴ —O) _h —, and —C (═O) —R ¹⁵ — may have a substituent.

Examples of the substituent include linear or branched alkyl groups having 1 to 6 carbon atoms, cycloalkyl groups having 3 to 6 carbon atoms, aryl groups having 6 to 12 carbon atoms, and halogen atoms. When there are two or more substituents, the respective substituents may be the same and different.

Note that the above-described alkylene group, — (R ¹⁴ —O) _h —, and —C (═O) —R ¹⁵ — may have a substituent.

In the general formula (1A), the group having an unsaturated double bond represented by R ¹¹ , R ¹² and R ¹³ is not particularly limited. For example, the general formula (1C) or the general formula (3C) described later is used. , Vinyl group, allyl group, vinyloxy group, isopropenyl group, 1-propenyl group, 2-butenyl group, 3-butenyl group, 1,3-butadienyl group, 2-pentenyl group, geranyl group, oleyl Group, cycloalkenyl group (for example, 2-cyclopenten-1-yl group, 2-cyclohexen-1-yl group), vinylbenzyl group, cinnamyl group and the like.

In the general formula (1A), the hydrophobic group represented by R ¹¹ , R ¹² and R ¹³ is not particularly limited, and examples thereof include an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 20 carbon atoms, Examples thereof include an aryl group having 6 to 24 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a carboxylic acid ester group, and a halogen atom.

The alkyl group having 1 to 18 carbon atoms may be a linear, branched or cyclic alkyl group, and may be unsubstituted or substituted. Examples of the substituent include the same alkylene groups as those described above for — (R ¹⁴ —O) _h — and —C (═O) —R ¹⁵ —.
Examples of the unsubstituted alkyl group having 1 to 18 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group.

Examples of the unsubstituted C3-C18 cyclic alkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a methylcyclopentyl group, a methylcyclohexyl group, and a methylcycloheptyl group. It is done.

The aryl group having 6 to 24 carbon atoms may be unsubstituted or substituted.
Examples of the unsubstituted aryl group having 6 to 18 carbon atoms include a phenyl group and a naphthyl group.

Examples of the substituted aryl group having 6 to 24 carbon atoms include aralkyl groups having 7 to 20 carbon atoms. The aralkyl group having 7 to 20 carbon atoms may be unsubstituted or further substituted. Examples of the substituent include the same alkylene groups as those described above for — (R ¹⁴ —O) _h — and —C (═O) —R ¹⁵ —.
Examples of the unsubstituted aralkyl group having 7 to 20 carbon atoms include a benzyl group, a phenylethyl group, and a phenylethenyl group.

The acyl group having 2 to 20 carbon atoms may be a linear or branched acyl group and may be unsubstituted or substituted. Examples of the substituent include the same alkylene groups as those described above for — (R ¹⁴ —O) _h — and —C (═O) —R ¹⁵ —.
Examples of the acyl group having 2 to 4 carbon atoms include an acetyl group, a propionyl group (propanoyl group), and a butyryl group.

The alkoxy group having 1 to 18 carbon atoms may be a linear or branched alkoxy group, and may be unsubstituted or substituted. Examples of the substituent include the same alkylene groups as those described above for — (R ¹⁴ —O) _h — and —C (═O) —R ¹⁵ —.
Examples of the alkoxy group having 1 to 18 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, hexyloxy group, phenoxy group, benzyloxy group and the like.

Examples of the carboxylic acid ester group include a carboxylic acid ester group represented by —COOR ^1A .
Examples of R ^1A in the carboxylic acid ester group include linear or branched alkyl groups having 1 to 12 carbon atoms, cyclic alkyl groups having 3 to 12 carbon atoms, and aryl groups having 6 to 12 carbon atoms.

The carboxylic acid ester group may be unsubstituted or substituted.
Examples of the substituent include the same alkylene groups as those described above, — (R ¹⁴ —O) _h —, and —C (═O) —R ¹⁵ —.

Specific examples of the unsubstituted carboxylic acid ester group include linear or branched alkyl ester groups having 2 to 12 carbon atoms (methyl ester group, ethyl ester group, etc.), and cycloalkyl esters having 4 to 12 carbon atoms. And groups (cyclopropyl ester group, cyclobutyl ester group, etc.), aryl ester groups having 7 to 12 carbon atoms (phenyl ester group, etc.).

Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

From the viewpoint of developing liquid crystallinity, examples of the hydrophobic group include linear or branched alkyl groups having 1 to 18 carbon atoms, cyclic alkyl groups having 3 to 18 carbon atoms, aryl groups having 6 to 18 carbon atoms, carbon A aralkyl group of 7 to 20, a linear or branched acyl group having 2 to 20 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, a carboxylate group represented by -COOR ^1A , or A halogen atom is preferred.

Among these, from the viewpoint of easy synthesis of the specific cellulose derivative, the hydrophobic group includes a linear or branched acyl group having 5 to 20 prime atoms and a linear or branched acyl group having 2 to 4 carbon atoms. At least one of straight chain and branched chain is acceptable.

In the general formula (1A), n11 is 2 or more and 800 or less, preferably 2 or more and 400 or less, more preferably 2 or more and 300 or less, from the viewpoint of obtaining a liquid crystal film having appropriate rubber elasticity by crosslinking.

Note that the above-described alkylene group, — (R ¹⁸ —O) _i —, and —C (═O) —R ¹⁹ — may have a substituent. Examples of the substituent include the same substituents exemplified above.

The general formula (1A) preferably has a molecular structure represented by the following general formula (1A-1).

In the general formula (1A-1), R ¹ represents —CH ₂ —CH ₂ — or —CH ₂ —CH (CH ₃ ) —, and R ¹¹ , R ¹² and R ¹³ are each independently A hydrogen atom, a group having an unsaturated double bond, or a hydrophobic group, m1, t1 and r1 each independently represents an integer of 0 to 10, and n13 represents an integer of 2 to 800. To express. However, at least one of R ¹¹ , R ¹² and R ¹³ is at least one of a group having an unsaturated double bond represented by the general formula (3C) and a linear or branched acyl group having 5 to 20 carbon atoms. Represents.

In the general formula ^(1A-1), R ^{11, R 12} and ^{R 13} has the same meaning as ^R ^{11, R 12} and ^{R 13} in the general formula (1A), and preferred ranges are also the same.
In the general formula (1A-1), m1, t1 and r1 are each independently preferably from 0 to 8, more preferably from 0 to 5, more preferably from the viewpoint of easy synthesis of the specific cellulose derivative. Preferably it is 0 or more and 3 or less.

In general formula (1A-1), n13 has the same meaning as n11 in general formula (1A), and the preferred range is also the same.
In the general formula (1A-1), n13 is 2 or more and 800 or less, preferably 2 or more and 400 or less, more preferably 2 or more and 300 or less, from the viewpoint of obtaining a liquid crystal film having appropriate rubber elasticity by crosslinking. is there.

In the general formula (1A-1), when R ¹ is represented by —CH ₂ —CH (CH ₃ ) —, the molecular structure is represented by the following general formula (1a).

In the general formula ^{^{(1a), R 11, R}} 12, R 13, and n13 are the same meaning as ^{^{^{R 11, R 12, R 13}}} , and n13 in the general formula (1A-1). In general formula (1a), m11, t11 and r11 have the same meanings as m1, t1 and r1 in general formula (1A-1).

In the general formula (1A-1), when R ¹ is represented by —CH ₂ —CH ₂ —, the molecular structure is represented by the following general formula (1b).

In the general formula ^{^{(1b), R 11, R}} 12, R 13, and n13 are the same meaning as ^{^{^{R 11, R 12, R 13}}} , and n13 in the general formula (1A-1). M12, t12 and r12 have the same meanings as m1, t1 and r1 in formula (1A-1).

A preferred embodiment of the specific cellulose derivative is a cellulose derivative having a molecular structure represented by the general formula (1a) or a cellulose derivative having a molecular structure represented by the general formula (1b).
Specifically, in the general formula (1a), the hydrophobic group (R ¹¹ , R ¹² or R ¹³ ) is an acyl group having 2 to 4 carbon atoms or an acyl group having 5 to 20 carbon atoms, The group having a double bond (R ¹¹ , R ¹² or R ¹³ ) is a group represented by the general formula (3C) and a (meth) acryloyl group, and m11, t11 and r11 are each independently 0 An embodiment wherein the integer is 3 or less and n13 is 2 or more and 300 or less; in the general formula (1b), the hydrophobic group (R ¹¹ , R ¹² or R ¹³ ) is an acyl group having 2 to 4 carbon atoms Or an acyl group having 5 to 20 carbon atoms and having an unsaturated double bond (R ¹¹ , R ¹² or R ¹³ ) is a group represented by the general formula (3C) and a (meth) acryloyl group M12, t12 and r12 are each independently 0 A top 3 an integer, n13 is an embodiment is 2 to 300.

-Groups with unsaturated double bonds-
In general formula (1A) and general formula (1A-1), as the group having an unsaturated double bond represented by R ¹¹ , R ¹² and R ¹³ , a liquid crystal film having excellent rubber elasticity is obtained by crosslinking. From the viewpoint, at least one of R ¹¹ , R ¹² and R ¹³ preferably represents a group having an unsaturated double bond represented by the following general formula (3C).

R ^3C represents a hydrogen atom or a methyl group, X ³⁸ represents a linear or branched alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O—, a carbonyl group, 2 to 20 represents a group selected from the group consisting of 20 linear or branched alkyleneoxy groups, aryl groups and cycloalkylene groups having 3 to 10 carbon atoms, or a group obtained by linking at least one of these groups, and ** represents the above general formula In (1A), it represents a moiety bonded to X ¹¹ , X ¹² , or X ¹³ or a moiety bonded to an oxygen atom at the 2nd, 3rd, or 6th position of the cellulose skeleton.

In the general formula (3C), the linear or branched alkylene group having 3 to 20 carbon atoms is a linear or branched alkylene group having 5 to 20 carbon atoms from the viewpoint of obtaining a liquid crystal film excellent in rubber elasticity. It is more preferably a linear alkylene group having 5 to 20 carbon atoms, still more preferably a linear alkylene group having 5 to 15 carbon atoms, particularly preferably 5 to 10 carbon atoms. A straight-chain alkylene group, and even more preferably a straight-chain alkylene group having 7 to 10 carbon atoms.

In the general formula (3C), the linear or branched alkyleneoxy group having 2 to 20 carbon atoms is a linear alkyleneoxy group having 2 to 10 carbon atoms from the viewpoint of obtaining a liquid crystal film excellent in rubber elasticity. It is preferably a straight-chain alkyleneoxy group having 2 to 6 carbon atoms, and more preferably a straight-chain alkyleneoxy group having 2 to 4 carbon atoms.

X ³⁸ is preferably a divalent linking group having at least one of a urethane bond and an ester bond, and preferably a divalent linking group having a urethane bond, from the viewpoint of obtaining a liquid crystal film excellent in rubber elasticity. More preferred.
Further, by adjusting the number of atoms of linear X ^38, it can be adjusted rubber elasticity of the liquid crystal film, the strength and the like as appropriate.

Hereinafter, an example of a group represented by the general formula (3C) is shown. The group represented by the general formula (3C) is not limited by these. In the following general formulas (3C-1) to (3C-4), ** represents a bonding position.

The group represented by the general formula (3C) is a group represented by the general formula (3C-1), (3C-2), or (3C) from the viewpoint of easily obtaining a liquid crystal film that easily forms a crosslinked structure and is excellent in rubber elasticity. −3), more preferably a group represented by the general formula (3C-1) or (3C-2).

The groups having an unsaturated double bond represented by R ¹¹ , R ¹² and R ¹³ are each independently further represented by the following general formula (1C) from the viewpoint of obtaining a liquid crystal film having more excellent rubber elasticity by crosslinking. It is preferable to include.

The group represented by the general formula (3C) is a group represented by the general formula (3C-5) from the viewpoint of obtaining a liquid crystal film that easily forms a crosslinked structure and is further excellent in rubber elasticity. Is more preferable.

In the general formula (3C-5), R ^a represents a linear or branched alkyleneoxy group having 2 to 20 carbon atoms (the oxygen atom of the alkyleneoxy group is bonded to the carbonyl carbon), and R ^b is A linear or branched alkylene group having 3 to 20 carbon atoms is represented. R ^3C represents a hydrogen atom or a methyl group, and ** represents a binding site.
In the general formula (3C-5), the linear or branched alkyleneoxy group having 2 to 20 carbon atoms in R ^a is a linear or branched alkyleneoxy group having 2 to 20 carbon atoms from the viewpoint of obtaining a liquid crystal film excellent in rubber elasticity. It is preferably an alkyleneoxy group, more preferably a linear alkyleneoxy group having 4 to 16 carbon atoms, still more preferably a linear alkyleneoxy group having 4 to 12 carbon atoms, and a carbon number of 4 Even more preferably, it is a linear alkyleneoxy group of ˜8.
In the general formula (3C-5), the linear or branched alkylene group having 3 to 20 carbon atoms in R ^b is a linear alkylene group having 3 to 20 carbon atoms from the viewpoint of obtaining a liquid crystal film excellent in rubber elasticity. It is preferably a group, more preferably a linear alkylene group having 5 to 15 carbon atoms, and still more preferably a linear alkylene group having 5 to 10 carbon atoms.

In the general formula (1C), R ^1C represents a hydrogen atom or a methyl group, X ¹⁸ represents a single bond, a linear or branched alkylene group having 1 to 18 carbon atoms, or a cycloalkylene having 3 to 18 carbon atoms. 3 hydrogen atoms are removed from a group, an arylene group having 6 to 18 carbon atoms, —O—, —NH—, —S—, —C (═O) —, or a linear or branched alkane having 1 to 18 carbon atoms. A group obtained by removing three hydrogen atoms from a cycloalkane having 3 to 18 carbon atoms, a group obtained by removing three hydrogen atoms from an arene having 6 to 18 carbon atoms, and a group obtained by removing three hydrogen atoms from ammonia. A group selected from the group or a group obtained by linking these is represented, and p1 represents an integer of 1 or 2. However, the valence of X ¹⁸ is p1 + 1.
** represents a moiety bonded to X ¹¹ , X ¹² , or X ¹³ in the above general formula (1A), or the second position of the cellulose skeleton when X ¹¹ , X ¹² , or X ¹³ is a single bond, 3 Represents a moiety bonded to the oxygen atom at the 6th or 6th position.

Examples of the linear or branched alkylene group having 1 to 18 carbon atoms and the cycloalkylene group having 3 to 18 carbon atoms represented by X ¹⁸ include X ¹¹ , X ^12, and X ¹³ in the general formula (1A). The same thing as the alkylene group represented can be mentioned.

The arylene group having 6 to 18 carbon atoms represented by X ¹⁸ is not particularly limited, and examples thereof include a phenylene group and a naphthalene group.

X ¹⁸ is a group in which 3 hydrogen atoms are removed from a linear or branched alkane having 1 to 18 carbon atoms, a group in which 3 hydrogen atoms are removed from a cycloalkane having 3 to 18 carbon atoms, and 6 to 18 carbon atoms. the arene group obtained by removing three hydrogen atoms from, represented by X ¹⁸ linear or branched alkylene group having 1 to 18 carbon atoms, a cycloalkylene group and having a carbon number of 3 to 18 carbon atoms 6-18 Groups obtained by removing one hydrogen atom from each arylene group.

The linear or branched alkylene group, cycloalkylene group, arylene group, linear or branched alkane, cycloalkane, and arene represented by X ¹⁸ may have a substituent.
Examples of the substituent include the same alkylene groups as those described above, — (R ¹⁴ —O) _h —, and —C (═O) —R ¹⁵ —.

In the general formula (1C), the group selected from the group consisting of —O—, —NH—, —S—, and —C (═O) — represented by X ¹⁸ is not particularly limited. For example, “—C (═O) —NH— (CH ₂ ) ₂ —O—”, “—C (═O) —NH— (CH ₂ ) ₂ —O— (CH ₂ ) ₂ —O—” And “—C (═O) —NH—C (CH ₃ ) — (CH ₂ —O—) ₂ ”.

In the general formula (1C), p1 is preferably 1.

X ¹⁸ is preferably a single bond or —C (═O) —NH— (CH ₂ ) ₂ —O— from the viewpoint of easily obtaining a liquid crystal film having appropriate rubber elasticity by crosslinking. .

In the general formula (1C), R ^1C is a hydrogen atom or a methyl group, X ¹⁸ is a single bond, and p1 is 1 is a (meth) acryloyl group. From the viewpoint of the crosslinking reaction, the group represented by the general formula (1C) is preferably a (meth) acryloyl group, and more preferably an acryloyl group.

Hereinafter, an example of a group represented by the general formula (1C) is shown. The group represented by the general formula (1C) is not limited by these. In the following general formulas (1C-1) to (1C-8), ** represents a bonding position.

The group represented by the general formula (1C-5) is a trivalent linking group in which X ¹⁸ is represented by the following general formula (1C-7) in the group represented by the general formula (1C), and R ^1C is a hydrogen atom and p1 is 2.
In General Formula (1C-7), *** represents a moiety bonded to the carbon atom bonded to CO in (COCH═CH ₂ ) in General Formula (1C-5).

In the general formula (1A) and general formula (1A-1), when the group having an unsaturated double bond represented by R ¹¹ , R ¹² and R ¹³ includes a group represented by the general formula (1C), From the viewpoint of obtaining a liquid crystal film that easily forms a crosslinked structure and is excellent in rubber elasticity, the groups represented by the general formula (1C) include the general formulas (1C-1), (1C-3), (1C −5) or (1C-6), more preferably a group represented by the general formula (1C-1) or (1C-3), and a group represented by the general formula (1C-3). More preferably it is.

In the general formula (1A) and the general formula (1A-1), the group having an unsaturated double bond represented by R ¹¹ , R ¹² and R ¹³ is easy to form a crosslinked structure, and has a rubber elasticity. From the viewpoint of obtaining an excellent liquid crystal film, it is preferable that both of the groups represented by the general formula (1C) and the general formula (3C) are included.

From the viewpoint of easily forming a crosslinked structure and obtaining a liquid crystal film having more excellent rubber elasticity, at least one of R ¹¹ , R ¹² and R ¹³ is preferably represented by the general formulas (3C-1), (3C— 2) or (3C-3) (more preferably a group represented by general formula (3C-1) or (3C-2)), and the other is preferably general formula (1C-1) Or (1C-3) (more preferably represented by the general formula (1C-1)).

In the general formula (1A) and the general formula (1A-1), R ¹¹ , R ^12, and R ¹³ are from the viewpoint of liquid crystallinity, excellent rubber elasticity, and a large wavelength shift of the reflection wavelength. , A hydrophobic group and a group having an unsaturated double bond, preferably a group having an unsaturated double bond, a linear or branched acyl group having 5 to 20 carbon atoms and a hydrophobic group. More preferably, it has all of a group having an unsaturated double bond, a linear or branched acyl group having 5 to 20 carbon atoms, and a linear or branched acyl group having 2 to 4 carbon atoms. Further preferred.
From the same viewpoint, the specific cellulose derivative has a degree of substitution per monomer unit of a group having an unsaturated double bond (hereinafter also referred to as “degree of substitution of a group having an unsaturated double bond”) of 0. It is preferably 01 or more and 2.0 or less.

The degree of substitution of a specific cellulose derivative refers to at least a part of hydroxyl groups or a part of hydroxyl groups among the three hydroxyl groups of cellulose monomer units (D-glucopyranose (β-glucose)). This is an index indicating the degree to which it is formed, and specifically means the average number (≦ 3) substituted with the above substituents.

In the present embodiment, “the degree of substitution of the group having an unsaturated double bond” means that when the specific cellulose derivative has a molecular structure represented by the general formula (1A), in the general formula (1A), R ¹¹ , The average number of “groups having an unsaturated double bond” introduced at the positions of R ¹² and R ¹³ is used.

Similarly, the degree of substitution per monomer unit of the hydrophobic group (hereinafter also referred to as “degree of substitution of the hydrophobic group”) is the case where the specific cellulose derivative has a molecular structure represented by the general formula (1A): In the general formula (1A), the average number of hydrophobic groups introduced at the positions of R ¹¹ , R ¹² and R ¹³ is used.

In the present embodiment, in the case of a group having an unsaturated double bond and a group corresponding to a hydrophobic group, the group is regarded as a “group having an unsaturated double bond”.

When the substitution degree of the group having an unsaturated double bond of the specific cellulose derivative is 0.01 or more and 2.0 or less, the expression of the thermotropic cholesteric liquid crystal can be improved, and the specific cellulose derivative after crosslinking Excellent rubber elasticity can be imparted.
Therefore, according to the liquid crystal material of the present embodiment, it is possible to produce a liquid crystal film having appropriate rubber elasticity and having an orientation fixed at the Bragg reflection wavelength by crosslinking the monomers of the specific cellulose derivative.

The degree of substitution of the group having an unsaturated double bond that the specific cellulose derivative has is preferably from 0.01 to 2.0, more preferably from the viewpoint of obtaining a liquid crystal film having appropriate rubber elasticity by crosslinking of the specific cellulose derivative. Is 0.1 or more and 1.5 or less, more preferably 0.2 or more and less than 1.0.

From the viewpoint of obtaining a liquid crystal film having appropriate rubber elasticity by crosslinking, in the specific cellulose derivative, the ratio of the substitution degree of the group having an unsaturated double bond and the substitution degree of a hydrophobic group (having an unsaturated double bond) Group / hydrophobic group) is preferably 3.0 × 10 ⁻³ or more and 2.0 or less, more preferably 3.0 × 10 ⁻² or more and 1.0 or less, and even more preferably 7.0 × 10 ⁻² or more. 0.5 or less.

When the group having an unsaturated double bond is a group represented by the general formula (3C-5), the degree of substitution of the group having an unsaturated double bond that the specific cellulose derivative has is excellent by crosslinking of the specific cellulose derivative. From the viewpoint of obtaining a liquid crystal film having rubber elasticity, it is preferably 0.01 or more and 1.0 or less, more preferably 0.01 or more and 0.5 or less, and still more preferably 0.01 or more and 0.1 or less.

When the group having an unsaturated double bond is a group represented by the general formula (3C-5), from the viewpoint of obtaining a liquid crystal film having excellent rubber elasticity by crosslinking, an unsaturated double bond in the specific cellulose derivative The ratio of the degree of substitution of the group having OH to the degree of substitution of the hydrophobic group (group having unsaturated double bond / hydrophobic group) is preferably 3.0 × 10 ⁻³ or more and 0.5 or less, more preferably Is 5.0 × 10 ⁻³ or more and 0.1 or less, more preferably 7.0 × 10 ⁻³ or more and 0.05 or less.

The degree of substitution of the group having an unsaturated double bond and the degree of substitution of the hydrophobic group are calculated from the integral values of characteristic proton peaks of each substituent by ¹ H-NMR.
Specifically, as shown in the examples described later, under the following measurement conditions, a ¹ H-NMR spectrum of a specific cellulose derivative solution dissolved in deuterated chloroform was measured, and based on the measured ¹ H-NMR spectrum. A proton peak derived from a group having an unsaturated double bond; a proton peak derived from a hydrophobic group; a proton peak derived from a cellulose skeleton (for example, a proton peak in a β-glucose monomer unit); In the case of (HPC), it can be calculated based on an integral value such as a proton peak of a methine group possessed by a hydroxypropyl group in a proton peak chain derived from HPC;

-Measurement condition-
Device: BRUKER: ULTRASHIELD400PLUS (model number)
Frequency: 400MHz

(Weight average molecular weight)
The weight average molecular weight of the specific cellulose derivative is preferably 20,000 or more and 200,000 or less, more preferably 50,000 or more and 200,000 or less, and still more preferably 100,000 or more, from the viewpoint of obtaining a liquid crystal film having excellent rubber elasticity by crosslinking. 200,000 or less.
The weight average molecular weight of the specific cellulose derivative can be calculated by gel permeation chromatography method (GPC) (polystyrene standard), and a molecular weight calibration curve created by a polystyrene standard sample from the measurement results obtained under the following measurement conditions is obtained. Can be used to calculate.

-Measurement condition-
Equipment: Tosoh Corporation: HLC-8220GPC (model number)
Solvent: Tetrahydrofuran Column: 0021815 TSKgel SuperMultipore HZ-N (particle diameter 3 μm, inner diameter 4.6 mm × length 15 cm, manufactured by Tosoh Corporation)
Flow rate: 0.15 mL / min Sample concentration: 2.0% by mass
Injection volume: 10 μL
Detector: Differential refraction detector Temperature: 40 ° C

Specific examples of the molecular structure represented by the general formula (1A) are shown below. The molecular structure represented by the general formula (1A) is not limited by these.

In the above formulas (1-13) to (1-16), in general formula (1A-1), R ¹ is —CH ₂ —CH (CH ₃ ) —, m1 is 2, and t1 is 2 In this example, r1 is 0.
Specific examples other than the above examples include molecular structures in which m1, t1, and r1 are each independently replaced with 0 or more and 10 or less.

In addition, in the above formulas (1-13) to (1-16), in general formula (1A-1), R ¹ is —CH ₂ —CH ₂ —, m1 is 2, and t1 is 2. , R1 is 0.
Specific examples other than the above examples include molecular structures in which m1, t1, and r1 are each independently replaced with 0 or more and 10 or less.

<Content of specific cellulose derivative>
The content of the specific cellulose derivative is preferably 80% by mass or more, more preferably 90% by mass or more, and 99% by mass or more with respect to the total mass of the liquid crystal material of the present embodiment. Is more preferable.

<Other ingredients>
The liquid crystal material of this embodiment may contain other components. Other components include, for example, polymerization initiators, crosslinking agents, flame retardants, compatibilizers, antioxidants, mold release agents (release agents), light proofing agents, weathering agents, modifiers, antistatic agents, hydrolysis An inhibitor etc. are mentioned.
As a polymerization initiator, well-known polymerization initiators, such as a thermal polymerization initiator and a photoinitiator, can be used, for example.
When the liquid crystal material of the present embodiment contains a photopolymerization initiator, examples of the photopolymerization initiator include 2-hydroxy-2-methyl-1-phenylpropane-1-one (HMPP), acetophenone, 1-hydroxycyclohexyl. Phenylketone, 2-hydroxy-4 '-(2-hydroxyethoxy) -2-methylpropiophenone, 2-methyl-4'-(methylthio) -2-morpholinopropiophenone, 2-benzyl-2- (dimethyl) Amino) -4'-morpholinobutyrophenone, phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide, bis (2,6-difluoro-3- (1-hydropyrrol-1-yl) phenyl) titanocene and the like It is done.

(Method for synthesizing specific cellulose derivative)
As an example of a method for synthesizing a specific cellulose derivative, a method for synthesizing a hydroxypropyl cellulose derivative having a molecular structure represented by the general formula (1A) will be described.
However, the method for synthesizing the specific cellulose derivative of the present embodiment is not limited to this.

A method for synthesizing a specific cellulose derivative is prepared by preparing hydroxypropyl cellulose (HPC) as a starting material, dissolving the HPC in a solvent to prepare an HPC solution, and the HPC solution represented by the general formula (3C). A compound having an unsaturated double bond group (hereinafter also referred to as “polymerizable compound”) and a linear or branched acyl group having 5 to 20 carbon atoms (hereinafter also referred to as “medium-chain hydrophobic group”). A mixing step of mixing at least one of the compounds having.
In the above mixing step, HPC and a polymerizable compound are reacted, and at least some of the hydrogen atoms of the three hydroxyl groups contained in the structural unit derived from HPC are converted into an unsaturated double represented by the general formula (3C). It can be substituted with a group having a bond or a medium chain hydrophobic group.
By the synthesis method having the above steps, a group having an unsaturated double bond represented by the general formula (3C) or a medium chain hydrophobic group is introduced into the side chain (terminal) of HPC to synthesize a specific cellulose derivative. And an HPC derivative having a molecular structure represented by the general formula (1a) (an example of the general formula (1A)) is obtained.

The mixing step further includes a compound having a hydrophobic group other than the medium chain hydrophobic group (hereinafter also simply referred to as “hydrophobic compound”), and the HPC solution contains the polysynthetic compound and the hydrophobic compound. It is preferable to mix, HPC solution and a polymerizable compound are mixed, and at least one of a group having an unsaturated double bond represented by the general formula (3C) in the side chain of HPC and a medium chain hydrophobic group is added. More preferably, after introduction, a hydrophobic compound is mixed to further introduce a hydrophobic group into the side chain of the HPC.

For example, when hydroxyethyl cellulose is used as a starting material, a specific cellulose derivative having a molecular structure represented by the general formula (1b) (an example of the general formula (1A)) can be obtained.
The specific cellulose derivative can be obtained, for example, by the following method.
First, an alkylene group, — (R ¹⁴ —O) _h — (R ¹⁴ ; alkylene group) is bonded between an oxygen atom bonded to the 2-position, 3-position, and 6-position of the cellulose skeleton and a hydrogen atom by a known method. h: an integer from 1 to 10) or a cellulose derivative having a linking group having —C (═O) —R ¹⁵ — (R ¹⁵ ; alkylene group) is prepared and used as a starting material.
Next, the hydrogen atom at the terminal of the cellulose derivative (starting material) is converted into a group having an unsaturated double bond represented by the general formula (3C) by a method according to the above method, and preferably a hydrophobic group. Replace.
Thereby, the cellulose derivative (specific cellulose derivative) which has the molecular structure represented by General formula (1A) is obtained.

When HPC is a starting material, the prepared HPC may be used as the HPC, or a commercially available HPC may be used.
Examples of commercially available products of HPC include hydroxypropyl cellulose sold by Wako Pure Chemical Industries, Ltd.

The solvent is not particularly limited as long as it can dissolve the starting material.
Examples of the solvent include ketones such as acetone, alcohols such as methoxypropanol, ethoxyethanol, and propanol, and tetrahydrofuran.

As the polymerizable compound, the group having an unsaturated double bond represented by the general formula (3C) and the group having the unsaturated double bond are represented by R ¹¹ and R ¹² in the general formula (1A). or not particularly limited as long as it can be introduced into R ^13.
Examples of such a polymerizable compound include a halide of a compound having an unsaturated double bond represented by the general formula (3C) in the molecule (for example, 10-undecenoyl chloride).
In addition, from the viewpoint of obtaining a liquid crystal film that easily forms a crosslinked structure and is excellent in rubber elasticity, the polysynthesized compound is a halogenated (meth) acryloyl (for example, (meth) acryloyl chloride, (meth) acryloyl bromide, etc. ); Isocyanate (meth) acrylate (for example, Karenz MOI (2-isocyanatoethyl methacrylate), Karenz AOI (2-isocyanatoethyl acrylate), Karenz BEI (1,1-bisacryloyl) manufactured by Showa Denko KK) Oxymethyl (ethyl isocyanate)), Karenz MOI-EG etc.) are preferably used in combination.

The hydrophobic compound is not particularly limited as long as it has the aforementioned hydrophobic group and can introduce the hydrophobic group into R ¹¹ , R ¹² or R ¹³ in the general formula (1A).
Among these, hydrophobic compounds include acyl halides (for example, acyl chloride (acetyl chloride, propionyl chloride, butyryl chloride, pentanoyl chloride, decanoyl chloride, etc.), acyl bromide (acetyl bromide, propionyl bromide, butyryl bromide, Pentanoyl bromide, decanoyl bromide, etc.), more preferably acyl chloride, and from the viewpoint of liquid crystallinity, linear or branched acyl chlorides having 2 to 4 carbon atoms are further preferred. Acetyl chloride, propionyl chloride or butyryl chloride is particularly preferable.
An example of a specific method for synthesizing cellulose derivatives will be described in the Examples section described later.

<Liquid Crystal Film>
The liquid crystal film of the present embodiment includes a cellulose derivative having a three-dimensional structure and having a molecular structure represented by the general formula (2A) (hereinafter also referred to as “cellulose derivative having a three-dimensional structure”). A group having a linking group for linking monomer units having a three-dimensional structure of a cellulose derivative having a structure.
The cellulose derivative having a three-dimensional structure is obtained by crosslinking monomer units derived from the cellulose derivative having the molecular structure represented by the general formula (1A).

The molecular structure represented by the general formula (1A) is such that at least one of R ²¹ , R ²² and R ²³ is a group connecting monomer units represented by the following general formula (4C) and a carbon number of 5 to 20 A specific cellulose derivative represented by at least one of a linear or branched acyl group.
Therefore, the specific cellulose derivative having a three-dimensional structure in the present embodiment is obtained by appropriately linking (crosslinking) monomer units with a linking group generated by cleavage of an unsaturated double bond, that is, These are obtained by crosslinking a polymer of a specific cellulose derivative.

In the present embodiment, it is considered that the three-dimensional structure contributes to the development of rubber elasticity of the liquid crystal film. The specific cellulose derivative having a three-dimensional structure has improved purification properties. This improvement in purification is considered to contribute to the development of cholesteric liquid crystal properties and rubber elasticity of the liquid crystal film.
Therefore, the liquid crystal film of this embodiment has rubber elasticity, and the orientation is fixed at the wavelength of Bragg reflection. Further, reflected light having a wavelength corresponding to the pressure is obtained by the mechanical pressure.

Here, the presence or absence of the formation of a three-dimensional structure (crosslinked structure) can be confirmed by dissolving the liquid crystal film before and after crosslinking in a solvent. Specifically, the liquid crystal film after crosslinking has a three-dimensional structure formed. Therefore, the liquid crystal film before cross-linking (that is, the liquid crystal material) in which the three-dimensional structure is not formed is dissolved in the solvent. Thus, the formation of a three-dimensional structure can be confirmed by comparing the presence or absence of solubility in a solvent.
Moreover, since the three-dimensional structure is formed without using a crosslinking agent, the liquid crystal film of this embodiment can be produced by a relatively simple method. In addition, you may bridge | crosslink monomer units using a crosslinking agent.
Moreover, although the liquid crystal film of this embodiment has the structure (three-dimensional structure) by which monomer units are bridge | crosslinked, this does not exclude the bridge | crosslinking in a monomer unit.

<Cellulose derivative having a three-dimensional structure>
The cellulose derivative having a three-dimensional structure has a molecular structure represented by the following general formula (2A).

In the general formula (2A), X ²¹ , X ²² and X ²³ each independently represent a single bond, an alkylene group, — (R ²⁴ —O) _j —, or —C (═O) —R ²⁵ —. R ²¹ , R ²² and R ²³ are each independently a hydrogen atom, a group having the linking group, or a hydrophobic group, R ²⁴ and R ²⁵ are each independently an alkylene group, j represents an integer of 1 to 10, and n21 represents an integer of 2 to 800. However, at least one of R ²¹ , R ²² and R ²³ is at least one of a group connecting monomer units represented by the following general formula (4C) and a linear or branched acyl group having 5 to 20 carbon atoms. Represents.

In the general formula (2A), the alkylene group represented by X ²¹ , X ²² and X ²³ has the same meaning as the alkylene group represented by X ¹¹ , X ¹² and X ¹³ in the general formula (1A), The preferable range is also the same.

In general formula (2A), — (R ²⁴ —O) _j — and —C (═O) —R ²⁵ — represented by X ²¹ , X ²² and X ²³ are the same as those in general formula (1A). Are the same as — (R ¹⁴ —O) _h — and —C (═O) —R ¹⁵ —, and the preferred range is also the same.
In addition, — (R ²⁴ —O) _j — represents an alkyleneoxy group (alkylene ether group) or a polyalkyleneoxy group (polyalkylene ether group).

In the general formula (2A), the hydrophobic group represented by R ²¹ , R ²² and R ²³ has the same meaning as the hydrophobic group represented by R ¹¹ , R ¹² and R ¹³ in the general formula (1A). The preferred range is also the same.

From the viewpoint of easy synthesis of the cellulose derivative, the hydrophobic group preferably contains an acyl group having 2 to 4 carbon atoms (both linear and branched, the same shall apply hereinafter).

In the general formula (2A), n21 is 2 or more and 800 or less, preferably 2 or more and 400 or less, more preferably 2 or more and 300 or less, from the viewpoint of having appropriate rubber elasticity.

In the general formula (2A), a group connecting monomer units represented by R ²¹ , R ²² and R ²³ (hereinafter, also simply referred to as “group connecting monomer units”) has the following general formula (4C And a group having an unsaturated double bond represented by the general formula (3C) is a linking group generated by cleavage.

In the general formula (4C), R ^4C represents a hydrogen atom or a methyl group, X ⁴⁸ represents a linear or branched alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O—, Represents a group selected from the group consisting of a carbonyl group, a linear or branched alkyleneoxy group having 2 to 20 carbon atoms, an aryl group, and a cycloalkylene group having 3 to 10 carbon atoms, or a group obtained by linking these, * represents a monomer ** represents a bonding position when the units are linked to each other, and ** represents a portion bonded to X ²¹ , X ²² , or X ^{23 in the} general formula (2A), or the 2-position, 3-position of the cellulose skeleton, Alternatively, it represents a moiety bonded to the oxygen atom at the 6-position.

In the general formula (4C), the linear or branched alkylene group having 3 to 20 carbon atoms and the linear or branched alkyleneoxy group having 2 to 20 carbon atoms represented by X ⁴⁸ are the same as those in the general formula (1A). ¹¹ , X ¹² and X ¹³ are the same as the linear or branched alkylene group having 3 to 20 carbon atoms and the linear or branched alkyleneoxy group having 2 to 20 carbon atoms, and the preferred range is also the same. .

From the viewpoint of superior rubber elasticity, X ⁴⁸ represents a linear alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O—, a carbonyl group, and a linear alkylene group having 2 to 20 carbon atoms. It is preferably a group selected from the group consisting of oxy groups or a group obtained by linking these, a linear alkylene group having 5 to 15 carbon atoms, —NH—, —C (═O) O—, a carbonyl group, and A group selected from the group consisting of a linear alkyleneoxy group having 4 to 16 carbon atoms or a group in which these groups are connected is more preferable, and a linear alkylene group having 5 to 10 carbon atoms, —NH—, —C A group selected from the group consisting of (═O) O—, a carbonyl group, and a linear alkyleneoxy group having 4 to 12 carbon atoms, or a group in which these groups are connected, is more preferable. Chain alkylene group, —NH—, —C A group selected from the group consisting of (═O) O—, a carbonyl group, and a linear alkyleneoxy group having 4 to 8 carbon atoms, or a group obtained by linking these groups, is particularly preferred. A chain alkylene group, or a straight chain alkylene group having 5 to 7 carbon atoms, —NH—, —C (═O) O—, a carbonyl group, and a straight chain alkyleneoxy group having 4 to 8 carbon atoms are linked. More preferably, it is a group.

An example of a group represented by the general formula (4C) is shown below. The group represented by the general formula (4C) is not limited by these. Note that * and ** represent binding positions.

From the viewpoint of superior rubber elasticity, in the general formula (4C), R ^4C is a hydrogen atom, X ⁴⁸ is a linear alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O. A group selected from the group consisting of-, a carbonyl group, and a straight-chain alkyleneoxy group having 2 to 20 carbon atoms, or a group obtained by linking these groups, a straight-chain alkylene group having 5 to 15 carbon atoms,- It is more preferably a group selected from the group consisting of NH—, —C (═O) O—, a carbonyl group, and a linear alkyleneoxy group having 4 to 16 carbon atoms, or a group obtained by linking these groups. A group selected from the group consisting of a linear alkylene group of 5 to 10, a —NH—, —C (═O) O—, a carbonyl group, and a linear alkyleneoxy group of 4 to 12 carbon atoms, or a combination thereof. More preferred A group selected from the group consisting of a straight-chain alkylene group having 5 to 7 carbon atoms, —NH—, —C (═O) O—, a carbonyl group, and a straight-chain alkyleneoxy group having 4 to 8 carbon atoms, or A group in which these are linked is particularly preferable, and a linear alkylene group having 5 to 7 carbon atoms, or a linear alkylene group having 5 to 7 carbon atoms, —NH—, —C (═O) O—, A group in which a carbonyl group and a linear alkyleneoxy group having 4 to 8 carbon atoms are linked is more preferable.

From the viewpoint of having appropriate rubber elasticity, the group connecting monomer units preferably further includes a group represented by the following general formula (2C).

In the general formula (2C), R ^2C represents a hydrogen atom or a methyl group, X ²⁸ represents a single bond or a linear or branched alkylene group having 1 to 18 carbon atoms, or a cycloalkylene having 3 to 18 carbon atoms. 3 hydrogen atoms are removed from a group, an arylene group having 6 to 18 carbon atoms, —O—, —NH—, —S—, —C (═O) —, or a linear or branched alkane having 1 to 18 carbon atoms. A group obtained by removing three hydrogen atoms from a cycloalkane having 3 to 18 carbon atoms, a group obtained by removing three hydrogen atoms from an arene having 6 to 18 carbon atoms, and a group obtained by removing three hydrogen atoms from ammonia. Represents a group selected from the group or a group obtained by linking them, and p2 represents an integer of 1 or 2.
* Represents a bonding position when monomer units are linked to each other. ** represents a moiety bonded to X ²¹ , X ²² , or X ²³ in the above general formula (2A), or the second position of the cellulose skeleton when X ²¹ , X ²² , or X ²³ is a single bond, 3 Represents a moiety bonded to the oxygen atom at the 6th or 6th position.

In the general formula (2C), the linear or branched alkylene group having 1 to 18 carbon atoms and the cycloalkylene group having 3 to 18 carbon atoms represented by X ²⁸ include X ¹¹ in the general formula (1A), It has the same meaning as the alkylene group represented by X ¹² and X ^13, and preferred ranges are also the same.

In the general formula (2C), the arylene group having 6 to 18 carbon atoms represented by X ²⁸ is not particularly limited, and examples thereof include a phenylene group and a naphthalene group.

X ²⁸ is a group in which 3 hydrogen atoms are removed from a linear or branched alkane having 1 to 18 carbon atoms, a group in which 3 hydrogen atoms are removed from a cycloalkane having 3 to 18 carbon atoms, and 6 to 18 carbon atoms. the arene group obtained by removing three hydrogen atoms from, represented by X ^28, linear or branched alkylene group having 1 to 18 carbon atoms, a cycloalkylene group and having a carbon number of 3 to 18 carbon atoms 6-18 Groups obtained by removing one hydrogen atom from each arylene group.

In the general formula (2C), a linking group in which one or two or more selected from the group consisting of —O—, —NH—, —S—, and —C (═O) — represented by X ²⁸ is linked. There is no particular limitation, for example, —C (═O) —NH— (CH ₂ ) ₂ —O—, —C (═O) —NH— (CH ₂ ) ₂ —O— (CH ₂ ) ₂ —O—, —C (═O) —NH—C (CH ₃ ) — (CH ₂ —O—) ₂ can be mentioned.

In general formula (2C), X ²⁸ is preferably a single bond or —C (═O) —NH— (CH ₂ ) ₂ —O—.

In the group represented by the general formula (2C), a group in which R ^2C is a hydrogen atom or a methyl group, X ¹⁸ is a single bond, and p2 is 1 is generated by cleavage of a (meth) acryloyl group. It is a linking group.

In general formula (2C), p2 is preferably 1.

A preferred embodiment of the cellulose derivative having the molecular structure represented by the general formula (2A) is that the hydrophobic group (R ²¹ , R ²² or R ²³ ) in the general formula (2A) is an acyl group having 2 to 4 carbon atoms. Or a group having 5 to 20 carbon atoms and having a linking group (R ²¹ , R ²² or R ²³ ) represented by the general formula (2C) group (preferably in the general formula (2C) , X ²⁸ is a single bond or a group represented by —C (═O) —NH— (CH ₂ ) ₂ —O—, and a group represented by (4C) (preferably represented by the general formula (4C) In which R ^4C is a hydrogen atom, X ⁴⁸ is a linear alkylene group having 5 to 7 carbon atoms, and n21 is 2 or more and 300 or less.

Preferred embodiments of the group represented by the general formula (2C) include the following general formulas (2C-1) to (2C-6) from the viewpoint of appropriate rubber elasticity.
Below, an example of group represented by general formula (2C) is shown. The group represented by the general formula (2C) is not limited by these. Note that * and ** represent binding positions.

The linking group represented by the general formula (2C-5), in the linking group represented by the general formula ^(2C), be a trivalent linking ^{group X 28} is represented by the following general formula (2C-7) , R ^2C is a hydrogen atom and p2 is 2.

Among the groups having a linking group represented by the above general formula (2C), from the viewpoint of having appropriate rubber elasticity, the general formula (2C-1), (2C-3), (2C-5) or (2C— The group represented by 6) is preferable, and the group represented by General Formula (2C-1) or General Formula (2C-3) is more preferable.

Specific examples of the molecular structure represented by the general formula (2A) are shown below.
In addition, the molecular structure represented by the general formula (2A) is not limited by these. In the formula, * represents a bonding position.

In the above formulas (2-13) to (2-16), in general formula (1A-1), R ¹ is —CH ₂ —CH (CH ₃ ) —, m1 is 2, t1 is 2 In this example, r1 is 0.
Specific examples other than the above examples include molecular structures in which m1, t1, and r1 are each independently replaced with 0 or more and 10 or less.

<Degree of substitution of hydrophobic group>
In the liquid crystal film of the present embodiment, the degree of substitution per unit of hydrophobic group (the degree of substitution of the hydrophobic group) is adjusted to the ratio of the group having the linking group in the specific cellulose derivative, and is appropriate for the liquid crystal film. From the viewpoint of imparting rubber elasticity, it is preferably 1.0 or more and 2.9 or less, more preferably 2.0 or more and 2.9 or less, and further preferably 2.5 or more and 2.9 or less.
The degree of substitution of the hydrophobic group in the liquid crystal film of the present embodiment can be measured by the same method as the degree of substitution of the hydrophobic group in the liquid crystal material described above.

(Weight average molecular weight)
In the present embodiment, the weight average molecular weight of the specific cellulose derivative having a three-dimensional structure is not particularly limited.

<Content of specific cellulose derivative having three-dimensional structure>
As content of the specific cellulose derivative which has a three-dimensional structure, it is preferable that it is 80 mass% or more with respect to the total mass of the liquid crystal film of this embodiment, It is more preferable that it is 90 mass% or more, 99 mass % Or more is more preferable.

<Other ingredients>
The liquid crystal film of this embodiment may contain other components as long as the effects of this embodiment are not achieved. Other components include, for example, polymerization initiators, crosslinking agents, flame retardants, compatibilizers, antioxidants, mold release agents (release agents), light proofing agents, weathering agents, modifiers, antistatic agents, hydrolysis An inhibitor etc. are mentioned. As the polymerization initiator, a known polymerization initiator (for example, a thermal polymerization initiator or a photopolymerization initiator) can be used.
As a photoinitiator, it is synonymous with the photoinitiator in the liquid crystal material as stated above, and its preferable example is also the same.

《Liquid crystal film production method》
The method for producing a liquid crystal film of the present embodiment includes a step of applying the liquid crystal material of the above-described embodiment on the substrate (hereinafter also referred to as “liquid crystal material application step”), and applying heat to the liquid crystal material applied on the substrate. And a step of irradiating ultraviolet rays (hereinafter also referred to as “ultraviolet irradiation step”).
In the manufacturing method of the liquid crystal film of this embodiment, a liquid crystal film having rubber elasticity and having a Bragg reflection fixed at a specific wavelength can be obtained through the above steps. Furthermore, by applying a mechanical pressure, it is possible to manufacture a liquid crystal film from which reflected light having a wavelength corresponding to the pressure can be obtained.

(Liquid crystal material application process)
A liquid crystal material provision process is a process of providing the liquid crystal material of the said embodiment on a board | substrate.
It does not restrict | limit especially as a board | substrate, According to the objective, it can select suitably from what is normally used. Examples of the substrate include a glass substrate, a plastic substrate (for example, a polyethylene naphthalate (PEN) substrate, a polyethylene terephthalate (PET) substrate, a polycarbonate (PC) substrate, a polyimide (PI) substrate), an aluminum substrate, a stainless steel substrate, and the like. A semiconductor substrate such as a metal substrate or a silicon substrate can be used.
The thickness and shape of the substrate are not particularly limited, and it is preferable to select appropriately according to the purpose.
Examples of the method for applying the liquid crystal material onto the substrate include coating methods such as spin coating, dipping, and spraying; ink jet methods; screen printing methods; injection methods such as reduced pressure injection methods; and the like.
The form of the liquid crystal material may be solid (for example, powder) or liquid.
When the liquid crystal material is in a solid form, it may be mixed with a solvent at the time of use to form a liquid, and when the liquid crystal material has a liquid enough to be applied on the substrate, it may be used as it is, You may use what was mixed and adjusted to the viscosity which is easy to use.
Note that the liquid crystal material applied to the substrate may contain other components. Examples of the other components include the same components as those described above (for example, a polymerization initiator and a release agent).
It does not restrict | limit especially as a solvent, For example, the solvent illustrated by the term of the synthesis | combining method of the above-mentioned specific cellulose derivative can be used.

(Heat application process)
The heat application step is a step of applying heat to the liquid crystal material applied on the substrate to cure the liquid crystal material. By the heat application step, the unsaturated double bond of the specific cellulose derivative before cross-linking is cleaved and the monomer units are connected (cross-linked) via a linking group, resulting in rubber elasticity. The orientation is fixed at the wavelength of Bragg reflection.
The heat application method is not particularly limited, and examples thereof include a method of applying heat using a known heating device (an oven, an infrared heater, a hot plate).
The temperature at which heat is applied to the liquid crystal material is preferably 25 ° C. or higher and 130 ° C. or lower, more preferably 25 ° C. or higher, from the viewpoint of having appropriate rubber elasticity and fixing the orientation at the wavelength of Bragg reflection. It is 120 ° C. or lower, more preferably 25 ° C. or higher and 110 ° C. or lower. Note that the temperature at which heat is applied to the liquid crystal material is controlled so that the liquid crystal material falls within the above range.
In the heat application step, the orientation is easily fixed at the Bragg reflection wavelength by controlling the heat application conditions (temperature, heating time, etc.).

(UV irradiation process)
The ultraviolet irradiation step is a step of irradiating the liquid crystal material applied on the substrate with ultraviolet rays to cure the liquid crystal material. By the ultraviolet irradiation step, the unsaturated double bond of the specific cellulose derivative before crosslinking is cleaved and the monomer units are linked (crosslinked) via a linking group, and as a result, rubber elasticity is expressed. The orientation is fixed at the wavelength of Bragg reflection.
The temperature at which the liquid crystal material is irradiated with ultraviolet rays (hereinafter also referred to as “UV irradiation temperature”) is preferably 25 ° C. or higher and 130 ° C. or lower, more preferably 25 ° C. or higher and 120 ° C. or lower, and further preferably 25 ° C. or higher and 110 ° C. or lower. It is as follows. Note that the temperature at which the liquid crystal material is irradiated with ultraviolet rays is controlled so that the liquid crystal material falls within the above range.

Further, the irradiation intensity (UV illuminance) of ultraviolet rays (hereinafter also referred to as “UV irradiation intensity”) is preferably 1 mW / cm ² or more and 20 mW / cm ² or less, more preferably 5 mW / cm ² or more and 20 mW / cm ² or less, More preferably, it is 10 mW / cm ² or more and 20 mW / cm ² or less.
In the ultraviolet irradiation step, by controlling the UV irradiation temperature and the UV irradiation intensity in combination, a liquid crystal film whose orientation is fixed by different Bragg reflections is obtained.
Further, the irradiation time of ultraviolet rays is preferably 5 minutes to 10 hours, more preferably 10 minutes to 5 hours, and further preferably 20 minutes to 2 hours.

More specifically, by controlling the UV irradiation temperature within the above range, the thermotropic cholesteric liquid crystallinity of the specific cellulose derivative is expressed, and it becomes easy to adjust to a target color and a desired color is easily obtained. Then, the color obtained by the UV irradiation temperature is fixed by controlling the UV irradiation temperature within the above range and further controlling the UV irradiation intensity within the above range.
Accordingly, in the ultraviolet irradiation step, a multi-color liquid crystal film exhibiting a target color at a target location can be obtained by controlling both the UV irradiation temperature and the UV irradiation intensity (preferably UV irradiation time).
Such a multi-color liquid crystal film (that is, a film in which the orientation in different Bragg reflections is fixed) can be easily obtained by using, for example, a photomask. Details will be described later.

(Alignment film formation process)
The manufacturing method of the liquid crystal film of this embodiment may include a step of forming an alignment film on the substrate (alignment film forming step).
The manufacturing method of the liquid crystal film of this embodiment may have an alignment film formation process before the said liquid-crystal material provision process. By forming the alignment film, it is possible to easily fix the alignment at the Bragg reflection wavelength in the heat application step or the ultraviolet irradiation step. Note that the alignment film is preferably subjected to a rubbing treatment.
Through the above steps, the liquid crystal film of the present embodiment is obtained.

The thickness of the liquid crystal film is not particularly limited, but is preferably 50 μm or more and 2000 μm or less, more preferably 100 μm or more and 1500 μm or less, and further preferably 200 μm or more and 1000 μm or less.
Note that the liquid crystal film may be used by being peeled from the substrate, or may be used as it is formed on the substrate.

Here, an example of a method for producing a liquid crystal film in which the orientation is fixed at different Bragg reflection wavelengths will be described with reference to FIGS. 1 (A) and 1 (B). Here, a method for manufacturing a liquid crystal film using a photomask processed into a T-shape (using a negative photoresist) will be described.
As shown in FIG. 1A, an alignment film (not shown) is formed over the first substrate 12, and a rubbing process is performed on the alignment film. Similarly, an alignment film (not shown) is formed on the second substrate 14, and the alignment film is rubbed as necessary. Next, a liquid crystal material 18 is injected through a spacer (not shown) between the first substrate 12 and the second substrate 14 on which the alignment film is formed. Thereby, the liquid crystal cell 10 is obtained. The liquid crystal cell 10 includes a first substrate 12 with an alignment film and a second substrate 14 with an alignment film, and a liquid crystal material 18 provided between these substrates via a spacer (not shown).

Next, a photomask 16 cut into a T-shape is disposed above the liquid crystal cell 10, and the temperature of the liquid crystal cell 10 (liquid crystal material) is first from the side of the first substrate 12 on which the alignment film is formed. The liquid crystal cell 10 is heated to a temperature of (in FIG. 1A, X ° C .: for example, 105 ° C.). Thereafter, the liquid crystal cell 10 is irradiated with ultraviolet rays through the opening (T-shaped) of the photomask 16 for a predetermined time with a predetermined irradiation intensity (first UV irradiation). Thereby, the orientation of the portion of the liquid crystal material that has been subjected to the first UV irradiation at the first temperature is fixed by the first Bragg reflection.
Next, the photomask 16 is removed, and the liquid crystal cell 10 is cooled to a second temperature (Y ° C .: for example, 95 ° C. in FIG. 1B) lower than the first temperature (X ° C.). Maintain the temperature of. Thereafter, the entire liquid crystal cell 10 is irradiated with ultraviolet rays at a predetermined irradiation intensity for a predetermined time while maintaining the second temperature (second UV irradiation). Thereby, the orientation of the portion of the liquid crystal material that has been subjected to the second UV irradiation at the second temperature is fixed by the second Bragg reflection.

Through the above-described steps, the liquid crystal film 20 in which the orientation is fixed by different Bragg reflections and the liquid crystal cell 10A including the liquid crystal film 20 are obtained. The liquid crystal cell 10A includes a first substrate 12 with an alignment film and a second substrate 14 with an alignment film, and the liquid crystal film 20 provided between these substrates via a spacer (not shown). .
Note that the temperature of the liquid crystal cell (liquid crystal material) when irradiating with ultraviolet rays is the first temperature (X ° C. in FIG. 1A) from the second temperature (Y ° C. in FIG. 1B). It is preferable to increase the height. This makes it easier to fix the orientation with different Bragg reflections. Note that the first temperature may be lower than the second temperature (X ° C. <Y ° C.). Further, the alignment film may not be formed.

[Use of liquid crystal film]
The liquid crystal film of the present embodiment includes, for example, a polarizing film, a retardation film, a backlight, an antireflection film, a light diffusion film, a brightness enhancement film, an antiglare film, and the like; distortion, stretching, vibration, impact, etc. of an object Sensors (pressure sensor, strain sensor, expansion / contraction sensor, vibration sensor, impact sensor, etc.) that detect deformation caused by the reflection wavelength (preferably reflected color); biological information such as pulse wave, respiration, and cardiac motion , A wearable sensor that detects the wavelength of reflection (preferably a reflected color); an optical element using the optical film; an optical element other than the above; a liquid crystal display element;
The liquid crystal film of the present embodiment has rubber elasticity, and by applying mechanical pressure, it is possible to obtain reflected light having a wavelength corresponding to the mechanical pressure. Therefore, the liquid crystal film has a mechanical property depending on the reflected wavelength (preferably reflected color). It is preferable to use the sensor mounted on an optical element that can detect reflected light by applying a mechanical pressure or a sensor that can detect the target pressure.

<Sensor>
The sensor of this embodiment includes the liquid crystal film of the above embodiment.
Examples of the sensor include various sensors exemplified above.

<Strain sensor>
The sensor of the present embodiment is preferably a strain sensor that detects strain of an object.
Since the strain sensor according to the present embodiment includes the liquid crystal film according to the above-described embodiment, the deformation caused by the distortion of the object can be detected by the wavelength of reflection (preferably the reflected color).
For example, by installing the strain sensor of the present embodiment in advance at a position of an object (for example, a structure such as a bridge or a building) where distortion is likely to occur, the degree of distortion of the object can be detected. Further, the mechanical pressure due to the distortion (deformation) can be detected visually, that is, by the wavelength of reflection (preferably the reflected color).

<Wearable sensor>
The sensor of the present embodiment is preferably a wearable sensor that detects biological information. Wearable sensors are relatively small sensors that can be worn and used.
Since the wearable sensor of this embodiment is provided with the liquid crystal film of the said embodiment, biometric information can be detected with the wavelength of reflection (preferably reflection color).
For example, the strain sensor of the present embodiment is directly attached (for example, to the skin) or attached to a place where biometric information is to be acquired, or clothing, underwear, socks, gloves, ties, handkerchiefs, mufflers, watches, glasses, shoes, By attaching or attaching to slippers, hats, etc., biological information (pulse wave, breathing, cardiac motion, body movement (muscle movement, etc.)) is visible, that is, the wavelength of reflection (preferably reflected color) Can be obtained by:

<Optical element>
The optical element of this embodiment includes the liquid crystal film of the above embodiment.
When the optical element of the present embodiment is artificially applied with mechanical pressure or is previously installed at a place where mechanical pressure is naturally applied, different reflected light corresponding to the stress can be obtained. Applications of such optical elements include toys, emergency light sources, interiors (such as figurines and shelves), building members (such as floors, walls, and stairs), tableware, and containers.

The liquid crystal material and liquid crystal film of the present invention can be used not only for display materials of liquid crystal display elements, but also for photonic devices (various sensors utilizing liquid crystal properties (distortion sensors, wearable sensors, etc.), optical elements, etc.). Can be used. For this reason, it contributes to manufacture of parts used for display materials and photonic devices of liquid crystal display elements, and sales thereof.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In the following description, “%” is based on mass unless otherwise specified. “Wt%” means mass%.

Example 1-1
<Production of liquid crystal material 1-1>
HPC derivative 1-1 (HPC-UndE / PrE) was synthesized according to the following scheme.

In Example 2-1 described later, low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name: hydroxypropylcellulose 2.0 to 2.9, product number: 082-07925, weight average The molecular weight is 5.0 × 10 ⁴ ), and the first reagent to be added is 2.4 mL (11 mmol) of 10-undecenoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd., product number; U0008) and propionyl chloride (Tokyo Chemical Industry). HPC derivative 1-1 was synthesized in the same manner as in Example 2-1, except that it was changed to 13 mL (150 mmol) manufactured by Kogyo Co., Ltd. The obtained HPC derivative 1-1 was designated as a liquid crystal material 1-1.

With respect to the liquid crystal material 1-1, a ¹ H-NMR spectrum was measured (not shown), and based on the assigned peak, the degree of substitution with a group having an unsaturated double bond and the degree of substitution with a hydrophobic group Was calculated.
In the liquid crystal material 1-1, the substitution degree of the HPC side chain (hydrogen atom in the hydroxyl group) with an undecenoyl group (group having an unsaturated double bond) is 1.33, and the propionyl group (hydrophobic group) The degree of substitution was 1.62 (HPC-UndE / PrE (UndE: PrE = 1.33: 1.62)).

(Comparative Example 1-2)
<Preparation of liquid crystal material 1-2>
In accordance with the following scheme, low molecular weight hydroxypropyl cellulose (manufactured by Wako Pure Chemical Industries, Ltd., product name; hydroxypropyl cellulose 2.0 to 2.9, product number; 082-07925, weight average molecular weight: 5.0 × 10 ⁴ ) was used to synthesize HPC derivative 1-2 (HPC-AcE / PrE).

In Example 2-1 described later, low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name: hydroxypropylcellulose 2.0 to 2.9, product number: 082-07925, weight average Molecular weight: 5.0 × 10 ⁴ ), except that the first reagent added was changed to 2.4 mL (11 mmol) of acryloyl chloride and 13 mL (150 mmol) of propionyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.). The HPC derivative 1-2 was synthesized in the same manner as in Example 2-1. The obtained HPC derivative 1-2 was designated as a liquid crystal material 1-2.

The liquid crystal material 1-2 was measured for ¹ H-NMR spectrum (not shown), and based on the assigned peaks, the degree of substitution with a group having an unsaturated double bond and the degree of substitution with a hydrophobic group were determined. Was calculated.
In the liquid crystal material 1-2, the degree of substitution with an acryloyl group (group having an unsaturated double bond) is 0.55, and the degree of substitution with a propionyl group (hydrophobic group) is 2.24 (HPC-AcE / PrE (AcE: PrE = 0.55: 2.24)).

(Comparative Example 1-3)
<Preparation of liquid crystal material 1-3>
According to the following scheme, low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name: hydroxypropylcellulose 2.0 to 2.9, product number; 082-07925, weight average molecular weight: HPC derivative 1-3 (HPC-PrE) was synthesized using 5.0 × 10 ⁴ ).

In Example 2-1 described later, low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name: hydroxypropylcellulose 2.0 to 2.9, product number: 082-07925, weight average HPC derivative 1-3 (hereinafter referred to as “the molecular weight: 5.0 × 10 ⁴ )” was used in the same manner as in Example 2-1, except that the reagent initially added was changed to propionyl chloride 13 mL (150 mmol). Also referred to as “HPC-PrE”). This was designated as Liquid Crystal Material 1-3.

For the liquid crystal material 1-3, a ¹ H-NMR spectrum was measured (not shown), and the degree of substitution with hydrophobic groups was calculated based on the assigned peaks.
In the liquid crystal material 1-3, the substitution degree of the HPC side chain (hydrogen atom in the hydroxyl group) with a propionyl group (hydrophobic group) was 2.98 (HPC-PrE (PrE = 2.98)).

[Evaluation]
-Viscoelasticity of liquid crystal materials-
The viscosity at 25 ° C. of the liquid crystal materials 1-1 to 1-3 prepared above was measured using a rheometer (product name: MCR102, manufactured by Anton Paar Japan Co., Ltd., jig used: parallel plate diameter 8 mm, temperature controller: Peltier The temperature was measured using a temperature control stage), and the complex viscosity, storage elastic modulus and loss elastic modulus with respect to the angular frequency were determined. The results are shown in FIG. FIG. 3 shows the result of plotting the loss tangent against the angular frequency of the liquid crystal materials 1-1 to 1-3.
A larger loss tangent value indicates that the liquid crystal material has fluidity, that is, viscoelasticity is reduced.

As shown in FIG. 3, in the region where the angular frequency is small, the loss tangent of the liquid crystal material 1-1 (HPC-UndE / PrE) as an example was the smallest. This is because the HPC polymer network is oriented due to the low viscosity of the liquid crystal material 1-1 (HPC-UndE / PrE) in the region where the angular frequency is small, and the molecular helical structure of the cholesteric liquid crystal is self-organized. As a result, it is assumed that the fluidity has decreased.
On the other hand, in the region where the angular frequency is large, the loss tangent of the liquid crystal material 1-1 (HPC-UndE / PrE) as an example was the largest.
When an external force such as shear was applied to the HPC derivative, the liquid crystal material 1-1 as an example (HPC-UndE / PrE) showed the highest fluidity.
The liquid crystal material 1-1 in which the group having an unsaturated double bond substituted on the HPC side chain is an undecenoyl group shows higher fluidity than the liquid crystal materials 1-2 and 1-3 as comparative examples. Therefore, it can be seen that handling is easy and alignment treatment can be easily performed.

Example 2-1
<Preparation of liquid crystal material 2-1>
HPC derivative 2-1 was synthesized according to the following scheme.

Medium molecular weight hydroxypropylcellulose (HPC) dried at room temperature (25 ° C.) for 24 hours or more under reduced pressure (manufactured by Wako Pure Chemical Industries, Ltd., product name: hydroxypropylcellulose 6.0-10.0, product number: 086 −07945, weight average molecular weight: 1.5 × 10 ⁵ ) 6.2 g (16 mmol) was dissolved in 30 mL of ultra-dehydrated acetone in a nitrogen-filled flask and then shielded with aluminum foil at room temperature ( 25 ° C) 10-undecenoyl chloride (product number; U0008) manufactured by Tokyo Chemical Industry Co., Ltd., which is an acid chloride of a long-chain hydrocarbon group having an unsaturated double bond at the terminal (12 mmol) and 0.57 mL (7.0 mmol) of acryloyl chloride ((Tokyo Chemical Industry Co., Ltd., A0147)) were added and stirred for 24 hours.
Next, 13 mL (150 mmol) of propionyl chloride was added and stirred for 24 hours, and then the reaction solution was added dropwise to ultrapure water. After re-dissolving in special grade acetone and repeating the washing operation by dropping into ultrapure water three times or more, HPC derivative 2-1 as a product is obtained by drying under reduced pressure for one day or more (hereinafter referred to as “HPC-UndE”). / AcE / PrE "). This was designated as Liquid Crystal Material 2-1. The yield was 6.0g.
Further, the weight average molecular weight of HPC-UndE / AcE / PrE was measured by the method described above, and as a result, the weight average molecular weight was 1.5 × 10 ⁵ .

(Measurement of ¹ H-NMR spectrum)
The ¹ H-NMR spectrum of the liquid crystal material 2-1 synthesized above was measured.
As a peak derived from the HPC derivative 2-1 according to the present invention (specifically, derived from HPC-UndE / AcE / PrE), each peak near 5 ppm is a vinyl group ((a) in FIG. 4). It is a proton peak attached to a heavy bond, and a peak in the vicinity of 5.2 ppm is a proton peak at the terminal hydroxypropyl group methine group and undecenoyl group terminal. The peak in the vicinity of 1.0 ppm to 2.5 ppm is attributed to the methylene group of undecenoyl group and propionyl group ((b) and (c) of FIG. 4), the proton in the β-glucose monomer unit, and the hydroxypropyl group in the side chain. It is the proton of the methine group.

In the liquid crystal material 2-1, in the general formula (1A), R ¹¹ , R ¹² and R ¹³ are each independently an acryloyl group, an undecenoyl group or a propionyl group, and X ¹¹ , X ¹² and X ¹³ are each Independently, it is a single bond or (—CH ₂ —CH (CH ₃ ) —O—) _h (where h is an integer of 0 or more and 10 or less), and n11 is 70.

(Substitution degree of a group having an unsaturated double bond and substitution degree of a group having a hydrophobic group)
Based on the assigned peak, the HPC side chain (hydrogen atom in the hydroxyl group) has a degree of substitution with a group having an unsaturated double bond (ie, undecenoyl group or acryloyl group) and a hydrophobic group (ie, propionyl group). The degree of substitution was calculated.
The HPC derivative 2-1 has a degree of substitution to an undecenoyl group (group having an unsaturated double bond) of 0.61, and a degree of substitution to an acryloyl group (group having an unsaturated double bond) is 0.13. The substitution degree to the propionyl group (hydrophobic group) was 2.22 (HPC-UndE / AcE / PrE (UndE: AcE: PrE = 0.61: 0.13: 2.22)).

<Preparation of liquid crystal film 2-1>
2.0 wt% of polyvinyl alcohol (PVA) as a liquid crystal alignment film (Aldrich _{^{Corp., M W: 1.3 × 10 4}} ~ 2.3 × 10 4, the degree of hydrolysis (hydrolyzed): 87% ~ 89 %) aqueous solution Was prepared. Using a spin coater (Active: ACT-220D II), the PVA aqueous solution was spin-coated on a commercially available glass slide (substrate) at 800 rpm for 10 seconds and then at 1800 rpm for 20 seconds to obtain a PVA-coated substrate.
Then, the rubbing process was performed by rubbing the PVA-coated substrate 50 times in one axial direction using a stick wound with a cupra.
Further, in preparation for the peeling operation, the release agent was spin-coated at 500 rpm for 10 seconds and heat-treated on a hot stage at about 80 ° C. for about 3 minutes. As a result, a PVA glass substrate subjected to rubbing treatment and peeling treatment (hereinafter also referred to as “rubbing / peeling treatment PVA glass substrate”) was obtained.
A total of two rubbing / peeling-treated PVA glass substrates were produced.

At room temperature (25 ° C.), the liquid crystal material 1 was sandwiched with a polytetrafluoroethylene (PTFE) spacer of about 680 μm between two rubbing / peeling-treated PVA glass substrates.
Further, after shear alignment treatment was allowed to stand for 4 hours or longer, the liquid crystal cell 2-1 was heated to a specific temperature on a hot stage (manufactured by METTLER TRADE CO., LTD.) And left for about 20 minutes.

The liquid crystal cell 2-1 produced above was irradiated with ultraviolet rays at around 365 nm (9.5 mW) at 30 ° C. for 2 hours or more through an optical filter (UV-35 / UV-D36A) using a mercury xenon lamp as a light source. Irradiated. Thereafter, tweezers were inserted into the gaps of the liquid crystal cell, and the film was peeled off slowly to obtain a liquid crystal film 2-1.

-Optical properties of liquid crystal materials and liquid crystal films-
<Measurement of FT-IR spectrum>
Using the liquid crystal material 2-1 (HPC-UndE / AcE / PrE) obtained in Example 2, an FT-IR spectrum was measured by FT-IR (infrared total reflection absorption measurement method: ATR method). The results are shown in FIG. FIG. 5 is an FT-IR spectrum of Example 2-1.
As shown in FIG. 5, a peak of C═O stretching vibration appeared strongly in the vicinity of 1730 cm ⁻¹ . In addition, the peak of OH stretching vibration around 3300 cm ⁻¹ to 3600 cm ⁻¹ decreased. Therefore, it was confirmed that the liquid crystal material 2-1 (HPC-UndE / AcE / PrE) of Example 2 has a sufficient degree of substitution with the acryloyl group, propionyl group, and undecenoyl group.

[Evaluation]
-Wavelength shift change during compression-
The reflection spectrum of the liquid crystal film 2-1 (elastomer film) produced above was measured under the following conditions. After the thickness of the produced liquid crystal film 2-1 was measured using a caliper, the liquid crystal film 2-1 was compressed in the thickness direction by 30 μm using a self-made compression tuning cell. Using a small fiber multi-channel spectrometer (manufactured by Ocean Optics, model number: USB-4000), the transmission spectrum was measured every 30 μm, thereby measuring the change in wavelength shift during compression. The result is shown in FIG.
The film thickness of the liquid crystal film 2-1 was 710 μm.

-Pressure response-
Ratio of wavelength (λ) after compression to wavelength (λ ₀ ) before compression due to mechanical pressure with respect to compression rate (that is, film thickness reduction rate) when mechanical pressure is applied to liquid crystal film 2-1 , Also referred to as “standardized Bragg reflection wavelength”) and normalized Bragg reflection wavelengths of the liquid crystal films 2-2 to 2-4 described later were plotted to obtain a regression line (FIG. 10). Table 1 shows the slope values obtained from the regression line.
It can be seen that the closer the slope of the regression line is to 1, the better the pressure response, and the greater the shift in the wavelength of reflected light with respect to mechanical pressure.

(Example 2-2)
In Example 2-1, a liquid crystal material 2-2 and a liquid crystal film 2-2 were prepared in the same manner as in Example 2-1, except that the temperature at the time of UV irradiation of the liquid crystal cell was changed to 40 ° C. Was evaluated. The results are shown in FIG.
The film thickness of the liquid crystal film 2-2 was 640 μm.

(Example 2-3)
In Example 2-1, a liquid crystal material 2-3 and a liquid crystal film 2-3 were produced in the same manner as in Example 2-1, except that the temperature at the time of ultraviolet irradiation of the liquid crystal cell was changed to 60 ° C. Similar evaluations were made. The results are shown in FIG.
The film thickness of the liquid crystal film 2-3 was 700 μm.

(Example 2-4)
In Example 2-1, a liquid crystal material 2-4 and a liquid crystal film 2-4 were produced in the same manner as in Example 2-1, except that the temperature at the time of ultraviolet irradiation of the liquid crystal cell was changed to 70 ° C. Similar evaluations were made. The results are shown in FIG.
The film thickness of the liquid crystal film 2-4 was 670 μm.

Example 3
<Preparation of liquid crystal material 3>
HPC derivative 3 was synthesized according to the following scheme.

In Example 2-1, low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name; hydroxypropylcellulose 2.0 to 2.9, product number; 082-07925, weight average molecular weight; 5.0 × 10 ⁴ ) 4.5 g (10 mmol), the amount of ultra-dehydrated acetone was 22 mL, and the first added reagent was Karenz AOI (2-acryloyloxyethyl isocyanate) 2.1 mL (17 mmol), 24 hours The reagents were added after stirring, except that they were changed to 3.4 mL (17 mmol) of decanoyl chloride and 9.4 mL (83 mmol) of butyryl chloride, which are acid chlorides of a long-chain hydrocarbon group having no unsaturated double bond. In the same manner as in Example 2-1, HPC derivative 3 (hereinafter also referred to as “HPC-AcC / DecE / BuE”) was obtained. This was designated as Liquid Crystal Material 3.
The yield was 3.0 g.

(Measurement of ¹ H-NMR spectrum)
The ¹ H-NMR spectrum of the HPC derivative 3 synthesized above was measured.
As peaks derived from the HPC derivative 3 according to the present invention (specifically, peaks derived from HPC-AcC / DecE / BuE), peaks around 5.8 ppm, 6.1 ppm and 6.4 ppm are respectively two of acryloyl groups. A peak of protons attached to a heavy bond, and a peak around 4.7 ppm to 5.2 ppm is a proton peak of a methine group of a terminal hydroxypropyl group ((a) of FIG. 11). The peak in the vicinity of 2.7 ppm to 4.5 ppm is a proton peak in the β-glucose monomer unit, an ethylene group proton peak between the acryloyl group and the carbamate bond. The peak around 2.3 ppm is a proton peak of a methylene group adjacent to the ester bond in the decanoyl group and butyryl group ((b) of FIG. 11). The peaks in the vicinity of 0.9 ppm to 1.4 ppm are the proton peaks of the methyl group of the decanoyl group and the six methylene groups on the terminal side, and the proton peaks of the methyl group of the butyryl group ((( c)).

In the HPC derivative 3, in the general formula (1A), R ¹¹ , R ¹² and R ¹³ are each independently an acryloyl group, a decanoyl group or a butyryl group, and X ¹¹ , X ¹² and X ¹³ are each independently A single bond or (—CH ₂ —CH (CH ₃ ) —O—) _h (where h is an integer of 0 or more and 10 or less), and an HPC derivative 3 having a molecular structure in which n11 is 70. is there.

Based on the assigned peak, HPC side chain (hydrogen atom in the hydroxyl group) has a degree of substitution with a group having an unsaturated double bond (ie, acryloyl group) and a hydrophobic group (ie, decanoyl group and butyryl group). The degree of substitution was calculated.
The HPC derivative 3 has a substitution degree to a decanoyl group (hydrophobic group) of 0.53, a substitution degree to an acryloyl group (group having an unsaturated double bond), 0.14, and a butyryl group (hydrophobic group). The degree of substitution on the group was 2.33 (HPC-AcC / DecE / BuE (AcC: DecE: BuE = 0.14: 0.53: 2.33)).

The prepared liquid crystal material 3 was used in the same manner as in Example 2-1, except that the temperature at the time of UV irradiation of the liquid crystal cell in Example 2-1 was changed to 25 ° C. And the liquid crystal film 3 was produced and the same evaluation was performed. The obtained results are shown in FIGS. The film thickness of the liquid crystal film 3 was 680 μm.
FIG. 12 is an FT-IR spectrum of Example 3.

The normalized Bragg reflection wavelength of the liquid crystal film 3 produced above was plotted to obtain a regression line (FIG. 14). Table 1 shows the slope values obtained from the regression line.

For each of the liquid crystal films 2-1, 2-2, 2-3, 2-4 and the liquid crystal film 3 prepared above, the temperature (° C.), film thickness (μm), and regression line The slope is shown in Table 1.

As shown in Table 1, it can be seen that the liquid crystal films prepared from the liquid crystal materials 2-1 to 2-4 exhibit thermotropic cholesteric liquid crystal properties and have a large shift in the wavelength of reflected light with respect to mechanical pressure. .
The liquid crystal film 2-2 fixed at 40 ° C. showed particularly excellent pressure response.
In the liquid crystal film 3 having a decanoyl group having 5 or more carbon atoms that does not have an unsaturated double bond introduced into the HPC side chain, the crosslinking reaction of the acryloyl group proceeds by ultraviolet irradiation, and further exhibits a compression response. Recognize.

Example 4-1
<Preparation of liquid crystal material 4-1>
In Example 2-1, low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name; hydroxypropylcellulose 2.0 to 2.9, product number; 082-07925, weight average molecular weight: 5.0 × 10 ⁴ ), 10-undecenoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd., product number; U0008) 2.0 mL (9.6 mmol) and butyryl chloride (Tokyo Chemical Industry Co., Ltd.) The HPC derivative 4-1 (hereinafter also referred to as “HPC-UndE / BuE”) was obtained in the same manner as in Example 2-1, except that it was changed to 14.6 mL (140 mmol). The yield of HPC-UndE / BuE was 3.0 g.

In the HPC derivative 4-1, in the general formula (1A), R ¹¹ , R ¹² and R ¹³ are each independently an undecenoyl group or a butyryl group, and X ¹¹ , X ¹² and X ¹³ are each independently HPC derivative 4-1 having a single bond or (—CH ₂ —CH (CH ₃ ) —O—) _h (where h is an integer of 0 or more and 10 or less) and n11 is 70 It is.

A ¹ H-NMR spectrum of the HPC derivative 4-1 was measured (not shown), and a group having an unsaturated double bond in the HPC side chain (hydrogen atom in the hydroxyl group) based on the assigned peak (ie, , Undecenoyl group) and hydrophobic group (ie, butyryl group) were calculated.
The HPC derivative 4-1 has a degree of substitution with an undecenoyl group (group having an unsaturated double bond) of 0.36, and a degree of substitution with a butyryl group (hydrophobic group) of 2.62 (HPC-UndE / BuE (UndE: BuE = 0.36: 2.62)).

To the HPC derivative 4-1, 2-Hydroxy-2-methyl-1-phenylpropane-1-one (HMPP) (Tokyo Chemical Industry Co., Ltd.) was used as a photopolymerization initiator so as to be 1% by mass with respect to the total mass of the liquid crystal material. Co., Ltd., product number; H0991) was added and stirred. This was designated as Liquid Crystal Material 4-1.
Next, after spin coating 2 wt% polyvinyl alcohol (PVA) on a commercially available slide glass (substrate) at 800 rpm for 10 seconds, rubbing treatment was performed in the same manner as the production of the liquid crystal film 2-1, and rubbing / peeling treatment PVA. A glass substrate was produced.
On the substrate, a liquid crystal material 4-1 containing HMPP prepared as described above was placed between two glass substrates on which a release agent was spin-coated at 800 rpm for 10 seconds, similarly to the production of the liquid crystal film 2-1. The liquid crystal cell 4-1 was produced by sandwiching.
After the liquid crystal cell 4-1 was irradiated with ultraviolet rays, the liquid crystal elastomer film was peeled from the glass substrate to obtain a liquid crystal film 4-1.
The film thickness of the liquid crystal film 4-1 was about 500 μm.

The obtained liquid crystal film 4-1 was evaluated in the same manner as in Example 2-1. The obtained results are shown in FIGS.

(Example 4-2)
<Preparation of liquid crystal material 4-2>
In Example 2-1, low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name; hydroxypropylcellulose 2.0 to 2.9, product number; 082-07925, weight average molecular weight: 5.0 × 10 ⁴ ), 10-undecenoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd., product number; U0008) 3.0 mL (15 mmol) and butyryl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) ) HPC derivative 4-2 (hereinafter also referred to as “HPC-UndE / BuE”) was obtained in the same manner as in Example 2-1, except that the volume was changed to 14.1 mL (135 mmol).
The yield of HPC-UndE / BuE was 2.5 g.

A ¹ H-NMR spectrum of HPC derivative 4-2 was measured (not shown), and a group having an unsaturated double bond in the HPC side chain (hydrogen atom in the hydroxyl group) based on the assigned peak (ie, , Undecenoyl group) and hydrophobic group (ie, butyryl group) were calculated.
In the HPC derivative 4-2, the degree of substitution with the undecenoyl group (group having an unsaturated double bond) is 0.43, and the degree of substitution with the butyryl group (hydrophobic group) is 2.54 (HPC-UndE / BuE (UndE: BuE = 0.43: 2.54)).

HMPP as a photopolymerization initiator was added to the HPC derivative 4-2 at 1% by mass with respect to the total mass of the liquid crystal material and stirred. This was designated as Liquid Crystal Material 4-2.

In Example 4-1, a liquid crystal cell 4-2 and a liquid crystal film 4-2 were prepared in the same manner as in Example 4-1, except that the liquid crystal material 4-2 was used instead of the HPC derivative 4-1. Evaluation was performed in the same manner as in Example 2-1. The obtained results are shown in FIGS.
The film thickness of the liquid crystal film 4-2 was about 500 μm.

Example 5-1
<Preparation of liquid crystal material 5-1>
In Example 2-1, low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name; hydroxypropylcellulose 2.0 to 2.9, product number; 082-07925, weight average molecular weight: 5.0 × 10 ⁴ ), 10-undecenoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd., product number; U0008) 3.0 mL (15 mmol) and propionyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) ) HPC derivative 5-1 (hereinafter also referred to as “HPC-UndE / PrE”) was obtained in the same manner as in Example 2-1, except that the amount was changed to 11.8 mL (135 mmol).
The yield of HPC-UndE / PrE was 3.0 g.

A ¹ H-NMR spectrum of the HPC derivative 5-1 was measured (not shown), and a group having an unsaturated double bond in the HPC side chain (hydrogen atom in the hydroxyl group) based on the assigned peak (ie, , Undecenoyl group) and hydrophobic group (that is, propionyl group) were calculated.
The HPC derivative 5-1 has a degree of substitution with an undecenoyl group (group having an unsaturated double bond) of 0.43, and a degree of substitution with a propionyl group (hydrophobic group) of 2.55 (HPC-UndE / PrE (UndE: PrE = 0.43: 2.55)).

HMPP as a photopolymerization initiator was added to the HPC derivative 5-1 at 1 mass% with respect to the total mass of the liquid crystal material and stirred. This was designated as Liquid Crystal Material 5-1.

A liquid crystal cell 5-1 and a liquid crystal film 5-1 were produced in the same manner as in Example 4-1, except that the HPC derivative 5-1 was used instead of the HPC derivative 4-1 in Example 4-1. Evaluation was performed in the same manner as in Example 2-1. The obtained results are shown in FIGS.
The film thickness of the liquid crystal film 5-1 was about 500 μm.

(Example 5-2)
<Preparation of liquid crystal material 5-2>
In Example 2-1, low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name; hydroxypropylcellulose 2.0 to 2.9, product number; 082-07925, weight average molecular weight: 5.0 × 10 ⁴ ), 10-undecenoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd., product number; U0008) 6.0 mL (30 mmol) and propionyl chloride (Tokyo Chemical Industry Co., Ltd.) HPC derivative 5-2 (hereinafter also referred to as “HPC-UndE / PrE”) was obtained in the same manner as in Example 2-1, except that the volume was changed to 10.6 mL (120 mmol). The yield of HPC-UndE / PrE was 2.5 g.

A ¹ H-NMR spectrum of HPC derivative 5-2 was measured (not shown), and a group having an unsaturated double bond in the HPC side chain (hydrogen atom in the hydroxyl group) based on the assigned peak (ie, , Undecenoyl group) and hydrophobic group (that is, propionyl group) were calculated.
In the HPC derivative 5-2, the degree of substitution with an undecenoyl group (group having an unsaturated double bond) is 0.94, and the degree of substitution with a propionyl group (hydrophobic group) is 2.05 (HPC-UndE / PrE (UndE: PrE = 0.94: 2.05)).

HMPP as a photopolymerization initiator was added to the HPC derivative 5-2 at 1% by mass with respect to the total mass of the liquid crystal material and stirred. This was designated as Liquid Crystal Material 5-2.

A liquid crystal cell 5-2 and a liquid crystal film 5-2 were produced in the same manner as in Example 4-1, except that the HPC derivative 5-2 was used instead of the HPC derivative 4-1 in Example 4-1. Evaluation was performed in the same manner as in Example 2-1. The obtained results are shown in FIGS.
The film thickness of the liquid crystal film 5-2 was about 500 μm.

(Example 6)
<Preparation of liquid crystal materials 6-1 and 6-2>
In the same manner as in Example 4-1, the reagents to be added were 10-undecenoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd., product number; U0008) 1.5 mL (7.3 mmol) and butyryl chloride (Tokyo Chemical Industry Co., Ltd.). HPC derivative 6-1 (hereinafter also referred to as “HPC-UndE / BuE”) was synthesized in the same manner as in Example 4-1, except that the amount was changed to 14.6 mL (140 mmol). The yield of HPC derivative 6-1 was 3.0 g.
Further, HPC derivative 6-2 (hereinafter also referred to as “HPC-UndE / BuE”) was synthesized in the same manner as Example 4-1. The yield of HPC derivative 6-2 was 3.0 g.
Measure ¹ H-NMR spectra of HPC derivatives 6-1 and 6-2 (not shown), and based on the assigned peak, the unsaturated double bond was found in the HPC side chain (hydrogen atom in the hydroxyl group). The degree of substitution with the group having the same (ie, undecenoyl group) and the degree of substitution with the hydrophobic group (ie, butyryl group) were calculated.
The HPC derivative 6-1 has a substitution degree to the undecenoyl group (group having an unsaturated double bond) of 0.27 and a substitution degree to the butyryl group (hydrophobic group) of 2.67 (HPC-UndE / BuE (UndE: BuE = 0.27: 2.67)). This was designated as Liquid Crystal Material 6-1.

In the HPC derivative 6-2, the degree of substitution with an undecenoyl group (group having an unsaturated double bond) is 0.36, and the degree of substitution with a butyryl group (hydrophobic group) is 2.64 (HPC-UndE / BuE (UndE: BuE = 0.36: 2.64)). This was designated as Liquid Crystal Material 6-2.

In Example 4-1, the liquid crystal cells 6-1 and 6-2 and the liquid crystal cells 6-1 and 6-2 were prepared in the same manner as in Example 4-1, except that the HPC derivative 6-1 or 6-2 was used instead of the HPC derivative 4-1. Liquid crystal films 6-1 and 6-2 were produced.

(Comparative Example 7)
<Preparation of liquid crystal material 7>
In Comparative Example 1-2, HPC derivative 7 (hereinafter referred to as “hereinafter referred to as“ PCC derivative 7 ”) was prepared in the same manner as in Comparative Example 1-2, except that the reagent to be added was changed to 15.6 mL of butyryl chloride (Tokyo Chemical Industry Co., Ltd.) Also referred to as “HPC-AcE / BuE”). This was designated as a liquid crystal material 7.
For the liquid crystal material 7, ¹ H-NMR spectrum was measured (not shown), and the degree of substitution with a group having an unsaturated double bond and the degree of substitution with a hydrophobic group were calculated based on the assigned peak. did.
In the liquid crystal material 7, the degree of substitution with an acryloyl group (group having an unsaturated double bond) is 0.55, and the degree of substitution with a butyryl group (hydrophobic group) is 2.36 (HPC-AcE / BuE ( AcE: BuE = 0.55: 2.36)).

In Example 4-1, a liquid crystal cell 7 and a liquid crystal film 7 were produced in the same manner as in Example 4-1, except that the HPC derivative 7 was used instead of the HPC derivative 4-1.

[Evaluation]
-Film stretchability-
Using the tensile tester (product name: Autograph AGS-X, manufactured by Shimadzu Corporation), the liquid crystal films 6-1 and 6-2 and the liquid crystal film 7 prepared above were loaded with a load cell load of 500 N and a distance between chucks. The degree of stretching was measured under the conditions of 10 mm and a tensile speed of 10 mm / min.
In addition, it means that it is excellent in rubber elasticity, so that an extending | stretching degree is large. The results are shown in Table 2 and FIG.

As shown in FIG. 21, when the liquid crystal film 7 is compared with the liquid crystal films 6-1 and 6-2, the liquid crystal films 6-1 and 6-2 have a small maximum point stress (tensile strength). It can be seen that the maximum degree of stretch (%) is high and the film has excellent stretchability, that is, rubber elasticity.
Furthermore, when the degree of substitution of the group having an unsaturated double bond (undecenoyl group) in the side chain of the liquid crystal films 6-1 and 6-2 is increased, it can be stretched with a smaller force, and the maximum strain is also large. I understand that
As shown in Table 2, it can be seen that the rubber elasticity of the liquid crystal film of the present invention improves as the amount of unsaturated double bonds (for example, undecenoyl groups) introduced into the side chain of the specific cellulose derivative increases.

As described above, the liquid crystal material and the liquid crystal film of the present invention can be used not only for display materials of liquid crystal display elements but also for photonic devices such as various sensors such as strain sensors and wearable sensors using liquid crystal properties, and optical elements. Can also be used. For this reason, it contributes to manufacture of parts used for display materials and photonic devices of liquid crystal display elements, and sales thereof.

(Example 8)
<Preparation of liquid crystal material 8>
According to the following scheme, HPC derivative 8 (HPC-UndE / BuE) was synthesized.

In Example 2-1 described above, low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name: hydroxypropylcellulose 2.0 to 2.9, product number: 082-07925, weight average Molecular weight: 5.0 × 10 ⁴ ) 8 g (17.8 mmol), super dehydrated acetone 35 mL, first added reagent 10-undecenoyl chloride 2.6 mL (10.6 mmol), later added reagent The HPC derivative 8 (hereinafter also referred to as “HPC-UndE / BuE”) was obtained in the same manner as in Example 2-1, except that 17.6 mL (149 mmol) of butyryl chloride was used instead of propionyl chloride. The yield was 5.0 g.
The HPC derivative 8 has a degree of substitution with an undecenoyl group (group having an unsaturated double bond) of 0.40, and a degree of substitution with a butyryl group (hydrophobic group) of 2.55 (HPC-UndE / BuE (UndE : BuE = 0.40: 2.55)).

HMPP was added to the HPC derivative 8 as a photopolymerization initiator so as to be 2% by mass with respect to the total mass of the liquid crystal material, and stirred. This was designated as liquid crystal material 8.

A liquid crystal cell 8 and a liquid crystal film 8 were produced in the same manner as in Example 4-1, except that the HPC derivative 8 was used instead of the HPC derivative 4-1.
The thickness of the liquid crystal film 8 was 460 m.

FIG. 22 shows a stress-strain curve of the liquid crystal film 8 when the amount of ultraviolet light to be irradiated is changed during the production of the liquid crystal film 8, and the amount of ultraviolet light (10.8 J / cm ² to 48.6 J / cm ² ) is shown. FIG. 23 shows changes in elastic characteristics when changed. As shown in FIG. 23, when the amount of ultraviolet light is 10.8 J / cm ² to 27.0 J / cm ² , the elastic modulus and the maximum stress of the liquid crystal film 8 increase as the amount of light increases. It is presumed that this is caused by an increase in the number of crosslinking points that fix the molecular helical structure as the photocrosslinking reaction proceeds. On the other hand, when the amount of ultraviolet light was 27.0 J / cm ² to 48.6 J / cm ² , almost constant elastic characteristics were exhibited regardless of the amount of ultraviolet light. This suggests that the photocrosslinking reaction has sufficiently progressed. Below, the physical property was evaluated about the liquid crystal film 8 produced by irradiating the light quantity of 32.4 J / cm < ² > estimated that the photocrosslinking reaction fully progressed.

The transmission spectrum measured while heating the liquid crystal film 8 is shown in FIG. The same evaluation was performed with the HPC derivative 8, and the correlation between temperature and Bragg reflection wavelength was summarized as shown in FIG. From FIG. 25, it was found that the HPC derivative 8 before crosslinking was not only shifted in reflection wavelength by heating but also exhibited Bragg reflection only up to 70 ° C. On the other hand, the liquid crystal film 8 after cross-linking was not only small in the width of the long wavelength shift due to heating, but could exhibit Bragg reflection up to 175 ° C. Such stability to the heat of the liquid crystal film 8 is presumed to be due to the fact that the crosslinking point generated at the end of the Und group of the HPC derivative 8 suppresses the expansion and contraction of the molecular helical structure.

26 shows the change of the transmission spectrum in the process of compressing the liquid crystal film 8 equivalent to strain 0.3, and the lower part of FIG. 26 shows the transmission spectrum in the process of releasing the compression. As shown in FIG. 26, the Bragg reflection of the liquid crystal film 8 exhibited a substantially reversible behavior although it appeared on the short wavelength side of about 10 nm after being released from compression.

Further, when the compression and release cycle is repeated 100 times with the strain applied to the liquid crystal film 8 being 0.2, the change in the transmission spectrum is shown in FIG. 27, and the change in the reflection wavelength and the liquid crystal film 8 is shown in FIG. As shown in FIGS. 27 and 28, it was found that the optical characteristics of the liquid crystal film 8 showed a reversible behavior with respect to 100 repeated compressions, and was excellent in repeated compression resistance.

Also, the repeated compression resistance of the elastic properties of the liquid crystal film 8 was evaluated from a compression test. FIG. 29 shows a stress-strain curve when the liquid crystal film 8 is repeatedly compressed and released at a speed of 0.5 mm / min and a strain of 0.2. Further, FIG. 30 shows a change in elastic characteristics accompanying the repeated compression of the liquid crystal film 8 calculated from FIG. Moreover, the result of having done the test similar to the liquid crystal film 8 with respect to commercially available chloroprene rubber is shown in FIG. From FIG. 30, the elastic modulus of the liquid crystal film 8 did not change greatly due to repeated compression, like the chloroprene rubber. From this, it was found that the liquid crystal film 8 exhibits elastic properties equivalent to those of a commercially available chloroprene rubber when the strain is at least 0.2.

As shown in FIG. 31, when the liquid crystal film 8 was pressed against the concavo-convex substrate, only the protrusions were selectively changed to green. The change in the reflection wavelength at this time is shown in FIG. As can be seen from FIG. 32, when the liquid crystal film 8 was pressed against the concavo-convex substrate, the depression portion had a reflection wavelength of about 620 nm and the protrusion portion was about 510 nm. As shown in FIG. 33, when the liquid crystal film 8 was pressed against a 100-yen coin, fine irregularities such as the surface of the 100-yen coin could be detected due to the discoloration of the liquid crystal film 8. As a result of measuring the unevenness of this 100-yen coin with a precision instrument (Keyence Co., Ltd., VR-5000) (FIG. 34), it was found that the liquid crystal film 8 can detect the unevenness of 93 μm in width and 190 μm in height at the minimum.

Example 9
<Preparation of liquid crystal material 9>
According to the following scheme, HPC derivative 9 (HPC-UndE / DecE / BuE) was synthesized.

In Example 2-1 described above, low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name: hydroxypropylcellulose 2.0 to 2.9, product number: 082-07925, weight average In place of 8 g (17.8 mmol) of molecular weight; 5.0 × 10 ⁴ ), 35 mL of super-dehydrated acetone, 1.3 mL (5.3 mmol) of 10-undecenoyl chloride, and acryloyl chloride HPC derivative 9 (hereinafter “HPC-”) was prepared in the same manner as in Example 2-1, except that 1.2 mL (5.3 mmol) of decanoyl chloride and 17.6 ml (149 mmol) of butyryl chloride were used instead of propionyl chloride. Also referred to as “UndE / DecE / BuE”). The yield was 5.0 g.
HPC derivative 9 has a degree of substitution with an undecenoyl group (a group having an unsaturated double bond) of 0.22, a degree of substitution with a decanoyl group (acyl group) is 0.20, and a degree of substitution with a butyryl group Was 2.55 (HPC-UndE / DecE / BuE (UndE: DecE: BuE = 0.22: 0.20: 2.55)).

HMPP was added to the HPC derivative 9 as a photopolymerization initiator and stirred so as to be 2% by mass with respect to the total mass of the liquid crystal material. This was designated as a liquid crystal material 9.

A liquid crystal film 9 was produced by irradiating the liquid crystal cell 9 produced from the liquid crystal material 9 with ultraviolet rays having a light quantity of 32.4 J / cm ² .
The film thickness of the liquid crystal film 9 was 470 μm.

FIG. 35 shows the result of a compression test performed on the liquid crystal film 8 and the liquid crystal film 9 at a speed of 0.5 mm / min and a strain of 0.3. Further, the result of measuring the reflection wavelength while compressing the liquid crystal film 8 and the liquid crystal film 9 was combined with FIG. 35, and the relationship between the reflection wavelength, stress, and strain shown in FIG. 36 was obtained. As shown in FIG. 36, the reflection wavelength of the liquid crystal film 8 was shifted by a short wavelength from about 620 nm to 480 nm at a pressure of about 4.5 MPa. On the other hand, the liquid crystal film 9 realized a similar short wavelength shift of the reflection wavelength at a pressure of about 2.5 MPa. Thus, the liquid crystal film 9 was able to change color by detecting a smaller pressure on the liquid crystal film 8. This is presumably because the liquid crystal HPC derivative 9 has a smaller amount of UndE introduced than the HPC derivative 8, and as a result, the number of crosslinking points for fixing the molecular helical structure is reduced.

(Example 10-1)
<Preparation of liquid crystal material 10-1>
According to the following scheme, HPC derivative 10-1 (HPC-4HC / PrE) was synthesized.

In a flask light-shielded with aluminum foil and filled with nitrogen, 5.5 mL (34 mmol) of hexamethylene diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd., product number; H0324) and 4-hydroxybutyl acrylate (Tokyo Chemical Industry Co., Ltd.) ), Product name: 4-hydroxybutyl acrylate, product number: A1390) 2.2 mL (15.9 mmol) was added and stirred for 24 hours. After 300 mg of the product was dissolved in 3.0 mL of chloroform, 4-(((6-isocyanatohexyl) carbamoyl) oxyl) butyl acrylate was obtained by HPLC (product name; recycle preparative HPLC apparatus, Japan Analytical Industrial Co., Ltd.). (4H) was separated and chloroform was distilled off by evaporation.
Low molecular weight hydroxypropylcellulose (HPC) dried at room temperature (25 ° C.) for 24 hours or more under reduced pressure (manufactured by Wako Pure Chemical Industries, Ltd., product name: hydroxypropylcellulose 2.0 to 2.9, product number: 082 -07925, weight average molecular weight: 5.0 × 10 ⁴ ) 6.0 g (13.4 mmol) was dissolved in 110 mL of ultra-dehydrated acetone in a nitrogen-filled flask, and then heated in a light-shielded state with aluminum foil. Under conditions of (45 ° C.), 10.0 mL of ultra-dehydrated acetone in which 360 mg (1.2 mmol) of 4H having an unsaturated double bond at the terminal and one carbamate bond in the molecular chain was dissolved was added and stirred for 20 hours. .
Next, 15 mL (172 mmol) of propionyl chloride (PrCl) was added under room temperature (25 ° C.) conditions and stirred for 24 hours, and then the reaction solution was added dropwise to ultrapure water. After re-dissolving in special grade acetone and repeating the washing operation by dropping into ultrapure water three times, the product is dried under reduced pressure for 1 day or more to produce HPC derivative 10-1 (hereinafter referred to as “HPC-4HC / PrE”). Is also referred to as). The yield was 4.0 g.

(Measurement of ¹ H-NMR spectrum)
¹ H-NMR spectra of 4H and HPC derivative 10-1 synthesized above were measured.
In FIG. 37, as peaks derived from 4H, peaks near 5.8 ppm, 6.1 ppm and 6.4 ppm are peaks of protons attached to the double bond of the terminal acryloyl group, and peaks around 4.8 ppm. Is the peak of the amino group proton in the carbamate bond. The peaks near 4.2 ppm and 3.2 ppm are the proton peaks of the four methylene groups derived from 4-hydroxybutyl acrylate at 4H, and the peaks near 1.2 ppm to 1.8 ppm are the hexamethylene dimethyl peaks at 4H. This is a proton peak of six methylene groups derived from isocyanate.
In FIG. 38, as peaks of the HPC derivative 10-1 (specifically, HPC-4HC / PrE), the peaks around 5.8 ppm, 6.1 ppm and 6.4 ppm are respectively acryloyl groups at the ends. This is a proton peak attached to the double bond, and the peak around 5.0 ppm is the proton peak of the methine group of the terminal hydroxypropionyl group. Peaks in the vicinity of 1.0 ppm to 2.5 ppm are the methyl group of the hydroxypropyl group of the HPC side chain, the methylene group of the group having an unsaturated bond, the methylene group not adjacent to the nitrogen atom, and the methyl of the propionyl group. Group, a proton of a methylene group. The peak around 2.7 ppm to 4.6 ppm is a peak of other protons that HPC derivative 10-1 has.
Based on the assigned peak, HPC side chain (hydrogen atom in the hydroxyl group) has a degree of substitution with a group having an unsaturated double bond (ie, 4HC group) and substitution with a hydrophobic group (ie, propionyl group). The degree was calculated.
The HPC derivative 10-1 has a substitution degree to the 4HC group (group having an unsaturated double bond) of 0.080 and a substitution degree to the propionyl group (hydrophobic group) of 2.60 (HPC-4HC / PrE (4HC / PrE = 0.080: 2.60)). Further, this was used as a liquid crystal material Z-1 without adding a photopolymerization initiator.

(Examples 10-2 to 10-4)
<Preparation of liquid crystal materials 10-2 to 10-4>
In the synthesis method described above, HPC-4HC / PrE having different degrees of substitution with 4HC groups was synthesized by changing the amount of 4H to be added. This was designated as HPC derivatives 10-2, 10-3 and 10-4.
When the substitution degree to the 4HC group and the substitution degree to the propionyl group of the HPC derivatives 10-2, 10-3, and 10-4 were calculated, the HPC derivative 10-2 was (HPC-4HC / PrE (4HC / PrE = 0.046: 2.69)), HPC derivative 10-3 is (HPC-4HC / PrE (4HC / PrE = 0.023: 2.68)), and HPC derivative 10-4 is (HPC-4HC / PrE (4HC / PrE = 0.177: 2.66)).

HMPP as a photopolymerization initiator was added to HPC derivatives 10-2, 10-3, and 10-4 as a photopolymerization initiator so as to be 1% by mass with respect to the total mass of the liquid crystal material, followed by stirring. These were designated as liquid crystal materials 10-2, 10-3, and 10-4.

Using the prepared liquid crystal material 10-1, the liquid crystal film 10-1 was produced by irradiation with ultraviolet rays (wavelength: 365 nm, intensity 10.0 mW / cm ² ) for 30 minutes at room temperature (25 ° C.). Further, by using the liquid crystal materials 10-2, 10-3, and 10-4, and performing the same operation as the liquid crystal material 10-1, except that the ultraviolet irradiation time is 1 hour, the liquid crystal film 10- 2, 10-3 and 10-4 were prepared. The film thicknesses of the liquid crystal films 10-1, 10-2, 10-3, and 10-4 were 500 μm, 560 μm, 450 μm, and 470 μm, respectively.

The liquid crystal film 10-1 is a dumbbell test piece having a width of 12 mm, a length of 30 mm, a parallel part width of 5 mm, and a length of 10 mm. The liquid crystal films 10-2, 10-3, and 10-4 are JIS No. 7 dumbbells. The test piece was subjected to a tensile test using a small tabletop testing machine (product name: EZ-LX, manufactured by Shimadzu Corporation) at a tensile speed of 10 mm / min.

FIG. 39 shows a stress-strain curve in the stretching process of the liquid crystal film 10-1. Details of the results are shown in Table 3.

As shown in FIG. 39 and Table 3, it was found that the liquid crystal film 10-1 can be stretched by 100% or more. This is due to the fact that the side chain stretches with stretching due to the lengthening of the side chain having an unsaturated bond, so that the film is easily deformed flexibly. It was also confirmed that the reflection wavelength was shifted by a short wavelength with 100% or more stretching. This is presumed to be due to the shrinkage of the helical pitch because the thickness in the vertical direction decreases as the strain in the stretching direction increases.

FIG. 40 shows stress-strain curves in the stretching process of the liquid crystal films 10-2, 10-3, and 10-4. Details of the results are shown in Table 4.

Compared to the plastic liquid crystal film 10-1, the addition of the photopolymerization initiator allowed the photocrosslinking reaction to proceed sufficiently to improve the rubber elasticity. Furthermore, it was found that the greater the amount of 4HC groups (groups having unsaturated double bonds) introduced, the greater the modulus of elasticity and the maximum stress and the smaller the breaking strain. As compared with Example 6 and Comparative Example 7, these had larger breaking strain (maximum strain), and it was found that the tensile properties were improved by the introduction of 4HC groups.

FIG. 41 shows the change in the transmission spectrum during the stretching release process of the liquid crystal film 10-3. It was found that the Bragg reflection wavelength shifts shortly with stretching and returns to the initial wavelength when released. This means that reversible expansion and contraction is possible at least within the range of strain 0.2 with improvement in rubber elasticity of the liquid crystal film.

The disclosure of Japanese Patent Application No. 2018-63259 filed on Mar. 28, 2018 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually stated to be incorporated by reference, Incorporated herein by reference.

10, 10A liquid crystal cell, 12 first substrate, 14 second substrate, 16 photomask, 18 liquid crystal material, 20 liquid crystal film

Claims

A liquid crystal material comprising a cellulose derivative having a molecular structure represented by the following general formula (1A).

(In the general formula (1A), X 11 , X 12 and X 13 are each independently a single bond, an alkylene group, — (R 14 —O) h —, or —C (═O) —R 15 —. R 11 , R 12 and R 13 each independently represent a hydrogen atom, a group having an unsaturated double bond, or a hydrophobic group, and R 14 and R 15 each independently represents an alkylene group. H represents an integer of 1 to 10, and n11 represents an integer of 2 to 800, provided that at least one of R 11 , R 12 and R 13 is represented by the following general formula (3C). It represents at least one of the group having an unsaturated double bond and a linear or branched acyl group having 5 to 20 carbon atoms.)

(In the general formula (3C), R 3C represents a hydrogen atom or a methyl group, and X 38 represents a linear or branched alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O— Represents a group selected from the group consisting of a carbonyl group, a linear or branched alkyleneoxy group having 2 to 20 carbon atoms, an aryl group and a cycloalkylene group having 3 to 10 carbon atoms, or a group obtained by linking at least one of these groups. ** represents a moiety bonded to X 11 , X 12 , or X 13 in the general formula (1A), or a moiety bonded to an oxygen atom at the 2-position, 3-position, or 6-position of the cellulose skeleton. To express.)
The liquid crystal material according to claim 1, wherein the molecular structure represented by the general formula (1A) is a molecular structure represented by the following general formula (1A-1).

(In the general formula (1A-1), R 1 represents —CH 2 —CH 2 — or —CH 2 —CH (CH 3 ) —, and R 11 , R 12 and R 13 are each independently , A hydrogen atom, a group having an unsaturated double bond, or a hydrophobic group, m1, t1 and r1 each independently represents an integer of 0 to 10, and n13 is an integer of 2 to 800 Provided that at least one of R 11 , R 12 and R 13 is a group having an unsaturated double bond represented by the following general formula (3C) and a linear or branched acyl having 5 to 20 carbon atoms. Represents at least one of the groups.)

(In the general formula (3C), R 3C represents a hydrogen atom or a methyl group, and X 38 represents a linear or branched alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O— Represents a group selected from the group consisting of a carbonyl group, a linear or branched alkyleneoxy group having 2 to 20 carbon atoms, an aryl group and a cycloalkylene group having 3 to 10 carbon atoms, or a group obtained by linking at least one of these groups. ** represents a moiety bonded to X 11 , X 12 , or X 13 in the general formula (1A), or a moiety bonded to an oxygen atom at the 2-position, 3-position, or 6-position of the cellulose skeleton. To express.)
The group having an unsaturated double bond further includes a group represented by the following general formula (1C),
The hydrophobic group is a linear or branched alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, a carbon number A linear or branched acyl group having 2 to 4 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, a carboxylic acid ester group represented by —COOR 1A , or a halogen atom, wherein R 1A is a carbon atom 3. The liquid crystal material according to claim 1, further comprising a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms.

(In the general formula (1C), R 1C represents a hydrogen atom or a methyl group, X 18 represents a single bond, a linear or branched alkylene group having 1 to 18 carbon atoms, or a cycloalkylene group having 3 to 18 carbon atoms. Three hydrogen atoms were removed from an arylene group having 6 to 18 carbon atoms, —O—, —NH—, —S—, —C (═O) —, or a linear or branched alkane having 1 to 18 carbon atoms. A group consisting of a group obtained by removing 3 hydrogen atoms from a cycloalkane having 3 to 18 carbon atoms, a group obtained by removing 3 hydrogen atoms from an arene having 6 to 18 carbon atoms, and a group obtained by removing 3 hydrogen atoms from ammonia Or a group obtained by linking at least one of them, and p1 represents an integer of 1 or 2. However, X 18 has a valence of p1 + 1, and ** represents the above general formula (1A). ) in, X 11, X 12, or X 13 and forming Part, or represents a 2-position, 3-position, or a moiety that binds to be an oxygen atom in the 6-position of the cellulose backbone.)
The liquid crystal according to claim 3, wherein, in the general formula (1C), X 18 is a single bond or —C (═O) —NH— (CH 2 ) 2 —O—, and p1 is 1. material.
5. The liquid crystal material according to claim 3, wherein the hydrophobic group is a linear or branched acyl group having 2 to 4 carbon atoms.
6. The liquid crystal material according to claim 1, wherein the degree of substitution per monomer unit of the group having an unsaturated double bond is 0.01 or more and 2.0 or less.
The ratio of the degree of substitution per monomer unit of the group having an unsaturated double bond and the degree of substitution per monomer unit of the hydrophobic group (the group having an unsaturated double bond / the hydrophobic group) is: 7. The liquid crystal material according to claim 1, which is 3.0 × 10 −3 or more and 2.0 or less.
Has a three-dimensional structure,
Including a cellulose derivative having a molecular structure represented by the following general formula (2A),
The liquid crystal film in which the cellulose derivative includes a group having a group for connecting monomer units to each other.

(In the general formula (2A), X 21 , X 22 and X 23 are each independently a single bond, an alkylene group, — (R 24 —O) j —, or —C (═O) —R 25 —. R 21 , R 22 and R 23 are each independently a hydrogen atom, a group having a group connecting the monomer units, or a hydrophobic group, and R 24 and R 25 are each independently Represents an alkylene group, j represents an integer of 1 to 10, and n21 represents an integer of 2 to 800, provided that at least one of R 21 , R 22 and R 23 has the following general formula ( 4C) represents at least one of a group connecting the monomer units to each other and a linear or branched acyl group having 5 to 20 carbon atoms.)

(In the general formula (4C), R 4C represents a hydrogen atom or a methyl group, and X 48 represents a linear or branched alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O— Represents a group selected from the group consisting of a carbonyl group, a linear or branched alkyleneoxy group having 2 to 20 carbon atoms, an aryl group, and a cycloalkylene group having 3 to 10 carbon atoms, or a group obtained by linking these, * The bond position when the monomer units are linked to each other is represented, and ** represents the portion bonded to X 21 , X 22 , or X 23 in the general formula (2A), or the 2nd and 3rd positions of the cellulose skeleton. Or represents a moiety bonded to the oxygen atom at the 6-position.)
The liquid crystal film according to claim 8, wherein the degree of substitution per monomer unit of the hydrophobic group is 1.0 or more and 2.9 or less.
The liquid crystal film according to claim 8 or 9, wherein the molecular structure represented by the general formula (2A) is a molecular structure represented by the following general formula (2A-1).

(In the general formula (2A-1), R 2 represents —CH 2 —CH 2 — or —CH 2 —CH (CH 3 ) —, and R 21 , R 22 and R 23 are each independently , A hydrogen atom, a group having the linking group, or a hydrophobic group, m2, t2 and r2 each independently represents an integer of 0 to 10, and n23 represents an integer of 2 to 800. However, at least one of R 21 , R 22 and R 23 is at least a group connecting monomer units represented by the following general formula (4C) and a linear or branched acyl group having 5 to 20 carbon atoms. Represents one side.)

(In the general formula (4C), R 4C represents a hydrogen atom or a methyl group, and X 48 represents a linear or branched alkylene group having 3 to 20 carbon atoms, —NH—, —C (═O) O— Represents a group selected from the group consisting of a carbonyl group, a linear or branched alkyleneoxy group having 2 to 20 carbon atoms, an aryl group, and a cycloalkylene group having 3 to 10 carbon atoms, or a group obtained by linking these, * The bond position when the monomer units are linked to each other is represented, and ** represents the portion bonded to X 21 , X 22 , or X 23 in the general formula (2A), or the 2nd and 3rd positions of the cellulose skeleton. Or represents a moiety bonded to the oxygen atom at the 6-position.)
The group connecting the monomer units includes a group represented by the following general formula (2C),
The hydrophobic group is a linear or branched alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, a carbon number A linear or branched acyl group having 2 to 4 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, a carboxylic acid ester group represented by —COOR 2A , or a halogen atom, wherein R 2A is carbon The straight chain or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms is described in any one of claims 8 to 10. Liquid crystal film.

(In the general formula (2C), R 2C represents a hydrogen atom or a methyl group, X 28 represents a single bond, a linear or branched alkylene group having 1 to 18 carbon atoms, or a cycloalkylene group having 3 to 18 carbon atoms. Three hydrogen atoms were removed from an arylene group having 6 to 18 carbon atoms, —O—, —NH—, —S—, —C (═O) —, or a linear or branched alkane having 1 to 18 carbon atoms. A group consisting of a group obtained by removing 3 hydrogen atoms from a cycloalkane having 3 to 18 carbon atoms, a group obtained by removing 3 hydrogen atoms from an arene having 6 to 18 carbon atoms, and a group obtained by removing 3 hydrogen atoms from ammonia Represents a group selected from the above or a group obtained by linking them, and p2 represents an integer of 1 or 2. However, X 28 has a valence of p2 + 1, * represents a bond when monomer units are linked to each other. ** represents the position in the above general formula (2A) X 21, X 22, or a moiety that binds with X 23, or represents a 2-position, 3-position, or a moiety that binds to be an oxygen atom in the 6-position of the cellulose backbone.)
The liquid crystal according to claim 11, wherein, in the general formula (2C), X 28 is a single bond or —C (═O) —NH— (CH 2 ) 2 —O—, and p2 is 1. the film.
The liquid crystal film according to claim 11 or 12, wherein the hydrophobic group is a linear or branched acyl group having 2 to 4 carbon atoms.
Applying a liquid crystal material according to any one of claims 1 to 7 on a substrate;
A step of applying heat or irradiating ultraviolet rays to the liquid crystal material applied on the substrate;
A method for producing a liquid crystal film, comprising:
A sensor comprising the liquid crystal film according to any one of claims 8 to 13.
The sensor according to claim 15, wherein the sensor is a distortion sensor that detects distortion of an object.
The sensor according to claim 16, which is a wearable sensor that detects biological information.
An optical element comprising the liquid crystal film according to any one of claims 8 to 13.