JP7370002B2 - Liquid crystal materials, liquid crystal films, sensors and optical elements - Google Patents

Description

The present invention relates to liquid crystal materials, liquid crystal films, sensors, and optical elements.

Liquid crystal materials are not only used as display materials for liquid crystal displays, but in recent years, their optical properties have been utilized to make them suitable for photonic devices. Cellulose derivatives are known as one such liquid crystal material.
For example, Patent Document 1 below discloses a liquid crystal material containing a hydroxypropylcellulose derivative synthesized by replacing the hydrogen atom of the hydroxyl group of hydroxypropylcellulose with an acryloyl group, a butyryl group, etc. It is disclosed that by using this liquid crystal material which exhibits thermotropic cholesteric liquid crystal properties and has elasticity, it is possible to produce a liquid crystal film whose orientation is fixed at the wavelength of Bragg reflection.

Japanese Patent Application Publication No. 2018-48289

By using the liquid crystal material, optical properties derived from the liquid crystal material can be imparted to various articles, but each article is required to have various mechanical properties depending on its use.
On the other hand, the present inventors investigated and found that although the liquid crystal material described in Patent Document 1 has excellent optical properties, there is room for improvement in mechanical properties, and in particular, there is room for improvement in stretching properties. It turns out there's room.

Therefore, an object of the present invention is to solve the problems of the prior art described above and provide a liquid crystal material having excellent stretching properties.
A further object of the present invention is to provide a liquid crystal film, a sensor, and an optical element that have excellent stretching properties.

The gist of the present invention for solving the above problems is as follows.

［一般式（１）中、Ｘ¹¹、Ｘ¹²及びＸ¹³は、それぞれ独立に、単結合、アルキレン基、－（Ｒ¹⁴－Ｏ）_h－、又は－Ｃ（＝Ｏ）－Ｒ¹⁵－を表し、Ｒ¹¹、Ｒ¹²及びＲ¹³は、それぞれ独立に、水素原子、不飽和二重結合を有する基、又は疎水性基を表し、Ｒ¹⁴及びＲ¹⁵は、それぞれ独立に、アルキレン基を表し、ｈは、１以上１０以下の整数を表し、ｎ１１は、２以上８００以下の整数を表す。但し、Ｒ¹¹、Ｒ¹²及びＲ¹³の少なくとも１つは、下記一般式（３）：

（一般式（３）中、Ｒ^3aは、炭素数７～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^3bは、炭素数３～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^3cは、水素原子又はメチル基を表し、＊＊は、上記一般式（１）中、Ｘ¹¹、Ｘ¹²若しくはＸ¹³と結合する部分、又はセルロース骨格の２位、３位若しくは６位にある酸素原子と結合する部分を表す。）で表される不飽和二重結合を有する基を表す。］で表される分子構造を有するセルロース誘導体を含むことを特徴とする。
かかる本発明の液晶材料は、優れた延伸特性を有する。 The liquid crystal material of the present invention has the following general formula (1):

[In general formula (1), 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 represent a hydrogen atom, a group having an unsaturated double bond, or a hydrophobic group, and R ¹⁴ and R ¹⁵ each independently represent an alkylene group. , h represent an integer of 1 or more and 10 or less, and n11 represents an integer of 2 or more and 800 or less. However, at least one of R ¹¹ , R ¹² and R ¹³ is represented by the following general formula (3):

(In general formula (3), R ^3a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^3b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^3c represents a hydrogen atom or ^a methyl group, and ** represents a moiety bonding to X ¹¹ , X ¹² or represents a group having an unsaturated double bond represented by ] It is characterized by containing a cellulose derivative having a molecular structure represented by the following.
The liquid crystal material of the present invention has excellent stretching properties.

［一般式（１－１）中、Ｒ¹は、－ＣＨ₂－ＣＨ₂－、又は－ＣＨ₂－ＣＨ（ＣＨ₃）－を表し、Ｒ¹¹、Ｒ¹²及びＲ¹³は、それぞれ独立に、水素原子、不飽和二重結合を有する基、又は疎水性基を表し、ｍ１、ｔ１及びｒ１は、それぞれ独立に、０以上１０以下の整数を表し、ｎ１１は、２以上８００以下の整数を表す。但し、Ｒ¹¹、Ｒ¹²及びＲ¹³の少なくとも１つは、下記一般式（３）：

（一般式（３）中、Ｒ^3aは、炭素数７～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^3bは、炭素数３～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^3cは、水素原子又はメチル基を表し、＊＊は、上記一般式（１－１）中、－（Ｒ¹－Ｏ）_m1－、－（Ｒ¹－Ｏ）_t1－若しくは－（Ｒ¹－Ｏ）_r1－と結合する部分、又はセルロース骨格の２位、３位若しくは６位にある酸素原子と結合する部分を表す。）で表される不飽和二重結合を有する基を表す。］で表される分子構造である。この場合、液晶材料の延伸特性が更に向上する。 In a preferred example of the liquid crystal material of the present invention, the molecular structure represented by the above general formula (1) has the following general formula (1-1):

[In general formula (1-1), R ¹ represents -CH ₂ -CH ₂ - or -CH ₂ -CH(CH ₃ )-, and R ¹¹ , R ¹² and R ¹³ are each independently, Represents a hydrogen atom, a group having an unsaturated double bond, or a hydrophobic group, m1, t1, and r1 each independently represent an integer of 0 to 10, and n11 represents an integer of 2 to 800. . However, at least one of R ¹¹ , R ¹² and R ¹³ is represented by the following general formula (3):

(In general formula (3), R ^3a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^3b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^3c represents a hydrogen atom or a methyl group, and ** represents -(R ¹ -O) _m1 -, -(R ¹ -O) _t1 - or -(R ¹ -O) in the above general formula (1-1). ) Represents a group having an unsaturated double bond represented by _r1 -, or a moiety that binds to an oxygen atom at the 2nd, 3rd, or 6th position of the cellulose skeleton. ] It is a molecular structure represented by. In this case, the stretching properties of the liquid crystal material are further improved.

The liquid crystal material of the present invention preferably has an elongation at break of 50% or more. Such liquid crystal materials can be used in applications requiring high stretching properties.

The liquid crystal material of the present invention preferably further contains a substituted or unsubstituted alkyl (meth)acrylate compound. In this case, the tensile strength of the liquid crystal material is improved.

Here, it is preferable that the substituted or unsubstituted alkyl (meth)acrylate compound is substituted or unsubstituted butyl (meth)acrylate. In this case, the breaking strain of the liquid crystal material is further improved.

Further, it is preferable that the substituted or unsubstituted butyl (meth)acrylate is 4-hydroxybutyl acrylate. In this case, the restoring force of the liquid crystal material is further improved.

［一般式（２）中、Ｘ²¹、Ｘ²²及びＸ²³は、それぞれ独立に、単結合、アルキレン基、－（Ｒ²⁴－Ｏ）_j－、又は－Ｃ（＝Ｏ）－Ｒ²⁵－を表し、Ｒ²¹、Ｒ²²及びＲ²³は、それぞれ独立に、水素原子、モノマー単位同士を連結する基を有する基、又は疎水性基を表し、Ｒ²⁴及びＲ²⁵は、それぞれ独立に、アルキレン基を表し、ｊは、１以上１０以下の整数を表し、ｎ２１は、２以上８００以下の整数を表す。但し、Ｒ²¹、Ｒ²²及びＲ²³の少なくとも１つは、下記一般式（４）：

（一般式（４）中、Ｒ^4aは、炭素数７～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^4bは、炭素数３～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^4cは、水素原子又はメチル基を表し、＊は、モノマー単位同士が連結されたときの結合位置を表し、＊＊は、上記一般式（２）中、Ｘ²¹、Ｘ²²若しくはＸ²³と結合する部分、又はセルロース骨格の２位、３位若しくは６位にある酸素原子と結合する部分を表す。）で表されるモノマー単位同士を連結する基を有する基を表す。］で表される分子構造を有するセルロース誘導体を含むことを特徴とする。
かかる本発明の液晶フィルムは、優れた延伸特性を有する。 Moreover, the liquid crystal film of the present invention is
It has a three-dimensional structure,
General formula (2) below:

[In general formula (2), 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 each independently represent a hydrogen atom, a group having a group connecting monomer units, or a hydrophobic group, and R ²⁴ and R ²⁵ each independently represent an alkylene group. , j represents an integer from 1 to 10, and n21 represents an integer from 2 to 800. However, at least one of R ²¹ , R ²² and R ²³ has the following general formula (4):

(In general formula (4), R ^4a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^4b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^4c represents a hydrogen atom or a methyl group, * represents a bonding position when monomer units are connected to each other, and ** represents a bond to X ²¹ , X ²² or X ²³ in the above general formula (2) represents a group that has a group that connects monomer units represented by (a moiety that binds to an oxygen atom at the 2nd, 3rd, or 6th position of the cellulose skeleton). ] It is characterized by containing a cellulose derivative having a molecular structure represented by the following.
The liquid crystal film of the present invention has excellent stretching properties.

［一般式（２－１）中、Ｒ²は、－ＣＨ₂－ＣＨ₂－、又は－ＣＨ₂－ＣＨ（ＣＨ₃）－を表し、Ｒ²¹、Ｒ²²及びＲ²³は、それぞれ独立に、水素原子、モノマー単位同士を連結する基を有する基、又は疎水性基を表し、ｍ２、ｔ２及びｒ２は、それぞれ独立に、０以上１０以下の整数を表し、ｎ２１は、２以上８００以下の整数を表す。但し、Ｒ²¹、Ｒ²²及びＲ²³の少なくとも１つは、下記一般式（４）：

（一般式（４）中、Ｒ^4aは、炭素数７～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^4bは、炭素数３～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^4cは、水素原子又はメチル基を表し、＊は、モノマー単位同士が連結されたときの結合位置を表し、＊＊は、上記一般式（２－１）中、－（Ｒ²－Ｏ）_m2－、－（Ｒ²－Ｏ）_t2－若しくは－（Ｒ²－Ｏ）_r2－と結合する部分、又はセルロース骨格の２位、３位若しくは６位にある酸素原子と結合する部分を表す。）で表されるモノマー単位同士を連結する基を有する基を表す。］で表される分子構造である。この場合、液晶フィルムの延伸特性が更に向上する。 In a preferred example of the liquid crystal film of the present invention, the molecular structure represented by the above general formula (2) has the following general formula (2-1):

[In general formula (2-1), R ² represents -CH ₂ -CH ₂ - or -CH ₂ -CH(CH ₃ )-, and R ²¹ , R ²² and R ²³ are each independently, Represents a hydrogen atom, a group having a group that connects monomer units, or a hydrophobic group, m2, t2, and r2 each independently represent an integer of 0 to 10, and n21 is an integer of 2 to 800. represents. However, at least one of R ²¹ , R ²² and R ²³ has the following general formula (4):

(In general formula (4), R ^4a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^4b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^4c represents a hydrogen atom or a methyl group, * represents a bonding position when monomer units are connected to each other, and ** represents -(R ² -O) _m2 - in the above general formula (2-1). , -(R ² -O) _t2 - or -(R ² -O) _r2 -, or a part that bonds to the oxygen atom at the 2nd, 3rd or 6th position of the cellulose skeleton). Represents a group having a group that connects the represented monomer units. ] It is a molecular structure represented by. In this case, the stretching properties of the liquid crystal film are further improved.

Moreover, the sensor of the present invention is characterized by comprising the above-mentioned liquid crystal film. Such a sensor of the present invention has excellent stretching properties.

Moreover, the optical element of the present invention is characterized by comprising the above-mentioned liquid crystal film. Such an optical element of the present invention has excellent stretching properties.

According to the present invention, a liquid crystal material having excellent stretching properties can be provided.
Further, according to the present invention, a liquid crystal film, a sensor, and an optical element having excellent stretching properties can be provided.

FIG. 1 shows stress-strain curves during the stretching process of the liquid crystal films of Example 1 and Comparative Example 1. FIG. 2 shows stress-strain curves during the stretching process of the liquid crystal films of Examples 1 and 2. FIG. 3 shows stress-strain curves during the stretching process of the liquid crystal films of Example 2 and Comparative Example 2. 4(a) shows the change in the transmission spectrum during the compression-release process of the liquid crystal film of Example 2, and FIG. 4(b) shows the state of the liquid crystal film during the compression-release process of the liquid crystal film of Example 2. show. FIG. 5(a) shows the change in the reflection spectrum during the stretching and releasing process of the liquid crystal film of Example 2, and FIG. 5(b) shows the state of the liquid crystal film during the stretching and releasing process of the liquid crystal film of Example 2. show. FIG. 6(a) shows stress-strain curves for each cycle (1st, 2nd, 100th, and 1000th cycles) of the liquid crystal film of Example 2, and FIG. 6(b) shows each stress-strain curve of the liquid crystal film of Example 2. The peak wavelengths of the reflection spectra during stretching and release in cycles (1st, 2nd, 3rd, and 100th cycles) are shown, and FIG. 6(c) shows the state of the liquid crystal film of Example 2 in each cycle. FIG. 7 shows stress-strain curves during the stretching process of the liquid crystal films of Examples 3 and 4. FIG. 8(a) shows the change in reflection wavelength of the liquid crystal film of Example 4 during stretching, and FIG. 8(b) shows the change in reflection wavelength of the liquid crystal film of Example 4 when it is stretched on a 500 yen coin, a 100 yen coin, and a 1 yen coin. It shows the change in reflected wavelength when pressed against each of the FIG. 9 shows stress-strain curves during the stretching process of the liquid crystal films of Examples 5 and 6. FIG. 10 shows stress-strain curves during the stretching process of the liquid crystal films of Examples 7 to 9. Figure 11(a) shows the transmission spectrum change during the stretching-release process when right-handed circularly polarized (R-CPL) white light is incident, and Figure 11(b) shows the transmission spectrum change in left-handed circularly polarized (L-CPL) white light. It shows the change in transmission spectrum during the stretching-release process when white light is incident. FIG. 12 shows stress-strain curves during the stretching process of the liquid crystal films of Examples 10 to 12. FIG. 13 shows the biaxial stretching measuring device used in Example 13. FIG. 14(a) shows the change in the transmission spectrum during the biaxial stretching process, and FIG. 14(b) shows the change in the transmission spectrum when changing from the biaxially stretched state to the uniaxially stretched state. FIG. 15 shows the transmission spectrum change during the biaxial stretching process, FIG. 15(a) shows the transmission spectrum change when right-handed circularly polarized (R-CPL) white light is incident, and FIG. 15(b) shows the transmission spectrum change when right-handed circularly polarized (R-CPL) white light is incident. , shows the change in transmission spectrum when left circularly polarized (L-CPL) white light is incident. FIG. 16 shows the discoloration of the liquid crystal film of Example 13 during the biaxial stretching process.

Below, the liquid crystal material, liquid crystal film, sensor, and optical element of the present invention will be illustrated and explained in detail based on the embodiments thereof.

［一般式（１）中、Ｘ¹¹、Ｘ¹²及びＸ¹³は、それぞれ独立に、単結合、アルキレン基、－（Ｒ¹⁴－Ｏ）_h－、又は－Ｃ（＝Ｏ）－Ｒ¹⁵－を表し、Ｒ¹¹、Ｒ¹²及びＲ¹³は、それぞれ独立に、水素原子、不飽和二重結合を有する基、又は疎水性基を表し、Ｒ¹⁴及びＲ¹⁵は、それぞれ独立に、アルキレン基を表し、ｈは、１以上１０以下の整数を表し、ｎ１１は、２以上８００以下の整数を表す。但し、Ｒ¹¹、Ｒ¹²及びＲ¹³の少なくとも１つは、下記一般式（３）：

（一般式（３）中、Ｒ^3aは、炭素数７～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^3bは、炭素数３～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^3cは、水素原子又はメチル基を表し、＊＊は、上記一般式（１Ａ）中、Ｘ¹¹、Ｘ¹²若しくはＸ¹³と結合する部分、又はセルロース骨格の２位、３位若しくは６位にある酸素原子と結合する部分を表す。）で表される不飽和二重結合を有する基を表す。］で表される分子構造を有するセルロース誘導体を含むことを特徴とする。 <Liquid crystal material>
The liquid crystal material of this embodiment has the following general formula (1):

[In general formula (1), 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 represent a hydrogen atom, a group having an unsaturated double bond, or a hydrophobic group, and R ¹⁴ and R ¹⁵ each independently represent an alkylene group. , h represent an integer of 1 or more and 10 or less, and n11 represents an integer of 2 or more and 800 or less. However, at least one of R ¹¹ , R ¹² and R ¹³ is represented by the following general formula (3):

(In general formula (3), R ^3a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^3b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^3c represents a hydrogen atom or a methyl group, ^and ** represents a moiety bonded to X ¹¹ , X ¹² or represents a group having an unsaturated double bond represented by ] It is characterized by containing a cellulose derivative having a molecular structure represented by the following.

The liquid crystal material of this embodiment includes a cellulose derivative having a group having an unsaturated double bond in the side chain, represented by the general formula (3), and R ^3a is a long chain alkylene group with 7 to 20 carbon atoms. Because it contains rubber, it exhibits rubber elasticity and has excellent stretching properties.
Further, since the liquid crystal material of this embodiment includes a cellulose derivative having a group having an unsaturated double bond represented by general formula (3) in the side chain, the wavelength shift of reflected light in response to mechanical pressure is large. .

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

In general formula (1), the alkylene group (-R ¹⁴ -) in the group represented by -(R ¹⁴ -O) _h - includes the same alkylene groups as X ¹¹ , X ¹² and X ¹³ above. .
Examples of -(R ¹⁴ -O) _h - include ethyleneoxy, polyethyleneoxy, propyleneoxy, and polypropyleneoxy groups.
-(R ¹⁴ -O) _h - can be more specifically represented by -[(CH ₂ ) _n -O] _h -. Here, n is an integer of 1 or more and 5 or less.
h represents an integer of 1 or more and 10 or less, and from the viewpoint of obtaining a liquid crystal film having appropriate rubber elasticity by crosslinking, h is preferably 1 or more and 6 or less, more preferably 1 or more and 4 or less, and even more preferably 1 or more and 3 or less. It is.

In general formula (1), the alkylene group (-R ¹⁵ -) in the group represented by -C(=O)-R ¹⁵ - includes the same alkylene groups as X ¹¹ , X ¹² and X ¹³ above. It will be 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.

Note that the above-mentioned alkylene groups, -(R ¹⁴ -O) _h -, and -C(=O)-R ¹⁵ - may have a substituent.
Examples of the substituent include a linear or branched alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and a halogen atom. When there are two or more substituents, each substituent may be the same or different.

In general formula (1), the group having an unsaturated double bond represented by R ¹¹ , R ¹² and R ¹³ includes, for example, a group represented by general formula (3) described below, a vinyl group, an 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-cyclopentene) -1-yl group, 2-cyclohexen-1-yl group), vinylbenzyl group, cinnamyl group, etc.

In the general formula (1), the hydrophobic groups represented by R ¹¹ , R ¹² and R ¹³ are not particularly limited, and include, for example, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 20 carbon atoms, Examples include an aryl group having 6 to 24 carbon atoms, an aralkyl group having 7 to 20 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 substituents as those for the above-mentioned alkylene group, -(R ¹⁴ -O) _h -, and -C(=O)-R ¹⁵ -.
Examples of the unsubstituted alkyl group having 1 to 18 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and tert-butyl group.
Examples of the unsubstituted cyclic alkyl group having 3 to 18 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, methylcyclopentyl group, methylcyclohexyl group, methylcycloheptyl group, etc. It will be done.

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 substituents as those for the above-mentioned alkylene group, -(R ¹⁴ -O) _h -, and -C(=O)-R ¹⁵ -.
Further, the acyl group preferably has 2 to 4 carbon atoms, and 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 aryl group having 6 to 24 carbon atoms may be unsubstituted or substituted. Examples of the substituent include the same substituents as those for the above-mentioned alkylene group, -(R ¹⁴ -O) _h -, and -C(=O)-R ¹⁵ -.
Examples of the unsubstituted aryl group having 6 to 24 carbon atoms include phenyl group and naphthyl group.

The aralkyl group having 7 to 20 carbon atoms may be unsubstituted or substituted. Examples of the substituent include the same substituents as those for the above-mentioned alkylene group, -(R ¹⁴ -O) _h -, and -C(=O)-R ¹⁵ -.
Examples of the unsubstituted aralkyl group having 7 to 20 carbon atoms include benzyl group, phenylethyl group, and phenylethenyl 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 substituents as those for the above-mentioned alkylene group, -(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, and benzyloxy group.

The carboxylic acid ester group may be unsubstituted or substituted. Examples of the substituent include the same substituents as those for the above-mentioned alkylene group, -(R ¹⁴ -O) _h -, and -C(=O)-R ¹⁵ -.
Examples of the carboxylic ester group include a carboxylic ester group represented by -COOR ^1A . Here, examples of R ^1A include a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, and an aryl group having 6 to 18 carbon atoms.
Examples of unsubstituted carboxylic acid ester groups include linear or branched alkyl ester groups having 2 to 12 carbon atoms (methyl ester group, ethyl ester group, etc.), cycloalkyl ester groups having 4 to 12 carbon atoms (cyclopropyl ester group, etc.). group, cyclobutyl ester group, etc.), aryl ester group having 7 to 12 carbon atoms (phenyl ester group), and the like.

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

From the viewpoint of exhibiting liquid crystallinity, hydrophobic groups include linear or branched alkyl groups having 1 to 18 carbon atoms, cycloalkyl groups having 3 to 18 carbon atoms, aryl groups having 6 to 18 carbon atoms, and 7 carbon atoms. ~20 aralkyl group, a linear or branched acyl group having 2 to 20 carbon atoms, a straight chain or branched alkoxy group having 1 to 18 carbon atoms, -COOR ^1A (here, R ^1A is a carbon number 1 to 12 represents a straight-chain or branched alkyl group, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 18 carbon atoms), or a halogen atom.
In addition, from the viewpoint of ease of synthesizing cellulose derivatives, examples of hydrophobic groups include straight-chain or branched acyl groups having 5 to 20 carbon atoms, and straight-chain or branched acyl groups having 2 to 4 carbon atoms ( Either straight chain or branched chain is acceptable (the same applies hereinafter)), and at least one of the following is preferred.

In general formula (1), n11 represents an integer of 2 or more and 800 or less, and is 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. .

で表される分子構造であることが好ましい。本実施形態の液晶材料が一般式（１－１）で表される分子構造を有するセルロース誘導体を含む場合、延伸特性が更に向上する。 The molecular structure represented by the above general formula (1) is the following general formula (1-1):

It is preferable that it has a molecular structure represented by the following. When the liquid crystal material of this embodiment contains a cellulose derivative having a molecular structure represented by general formula (1-1), the stretching properties are further improved.

で表される不飽和二重結合を有する基を表す。
ここで、一般式（３）中、Ｒ^3aは、炭素数７～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^3bは、炭素数３～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^3cは、水素原子又はメチル基を表し、＊＊は、上記一般式（１－１）中、－（Ｒ¹－Ｏ）_m1－、－（Ｒ¹－Ｏ）_t1－若しくは－（Ｒ¹－Ｏ）_r1－と結合する部分、又はセルロース骨格の２位、３位若しくは６位にある酸素原子と結合する部分を表す。 In general formula (1-1), R ¹ represents -CH ₂ -CH ₂ - or -CH ₂ -CH(CH ₃ )-, and R ¹¹ , R ¹² and R ¹³ each independently represent hydrogen. represents an atom, a group having an unsaturated double bond, or a hydrophobic group, m1, t1 and r1 each independently represent an integer of 0 to 10, and n11 represents an integer of 2 to 800. However, at least one of R ¹¹ , R ¹² and R ¹³ is represented by the following general formula (3):

represents a group having an unsaturated double bond represented by
Here, in the general formula (3), R ^3a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^3b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, R ^3c represents a hydrogen atom or a methyl group, and ** represents -(R ¹ -O) _m1 -, -(R ¹ -O) _t1 - or -(R ¹ -O) represents a moiety that binds to _r1 - or a moiety that binds to an oxygen atom at the 2nd, 3rd, or 6th position of the cellulose skeleton.

In general formula (1-1), R ¹¹ , R ¹² and R ¹³ have the same meanings as R ¹¹ , R ¹² and R ¹³ in general formula (1) above, and their preferred ranges are also the same.

In general formula (1-1), m1, t1, and r1 each independently represent an integer of 0 to 10, and m1, t1, and r1 are selected from the viewpoint of ease of synthesis of cellulose derivatives. Independently, preferably 0 or more and 8 or less, more preferably 0 or more and 5 or less, even more preferably 0 or more and 3 or less.

In the general formula (1-1), n11 has the same meaning as n11 in the above general formula (1), and the preferred range is also the same. n11 represents an integer of 2 or more and 800 or less, and is 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.

で表される。 In general formula (1-1), when R ¹ is represented by -CH ₂ -CH(CH ₃ )-, the molecular structure is the following general formula (1a):

It is expressed as

In general formula (1a), R ¹¹ , R ¹² , R ¹³ and n11 have the same meanings as R ¹¹ , R ¹² , R ¹³ and n11 in general formula (1). Furthermore, in the general formula (1a), m11, t11, and r11 have the same meanings as m1, t1, and r1 in the general formula (1-1).

で表される。 In general formula (1-1), when R ¹ is represented by -CH ₂ -CH ₂ -, the molecular structure is the following general formula (1b):

It is expressed as

In general formula (1b), R ¹¹ , R ¹² , R ¹³ and n11 have the same meanings as R ¹¹ , R ¹² , R ¹³ and n11 in general formula (1). Furthermore, in the general formula (1b), m12, t12, and r12 have the same meanings as m1, t1, and r1 in the general formula (1-1).

A particularly preferred embodiment of the cellulose derivative is a cellulose derivative having a molecular structure represented by general formula (1a) or a cellulose derivative having a molecular structure represented by general formula (1b).
Specifically, in 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, and The group having a saturated double bond (R ¹¹ , R ¹² , or R ¹³ ) is a group represented by general formula (3), and m11, t11, and r11 are each independently 0 or more and 3 or less. An embodiment in which n11 is an integer of 2 to 300; In general formula (1b), the hydrophobic group (R ¹¹ , R ¹² , or R ¹³ ) is an acyl group having 2 to 4 carbon atoms or a carbon The number 5 to 20 acyl group having an unsaturated double bond (R ¹¹ , R ¹² , or R ¹³ ) is a group represented by the general formula (3), m12, t12, and r12 are each independently an integer of 0 or more and 3 or less, and n11 is 2 or more and 300 or less.

で表される不飽和二重結合を有する基である。 In the general formula (1) and the general formula (1-1), 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 can be obtained by crosslinking. From this point of view, at least one of R ¹¹ , R ¹² and R ¹³ has the following general formula (3):

It is a group having an unsaturated double bond represented by

In the general formula (3), R ^3a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^3b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^3c represents a straight chain or branched alkylene group having 3 to 20 carbon atoms. , represents a hydrogen atom or a methyl group, and ** represents a moiety bonding to X ¹¹ , X ¹² or X ¹³ in the above general formula (1), -(R ¹ -O) in general formula (1-1) _m1 -, -(R ¹ -O) _t1 - or -(R ¹ -O) _r1 - represents a moiety that bonds with the oxygen atom at the 2nd, 3rd, or 6th position of the cellulose skeleton. When R ^3a in the general formula (3) is a long-chain alkylene group having 7 to 20 carbon atoms, the rubber elasticity of the cellulose derivative is improved, and the stretching properties of the liquid crystal material containing the cellulose derivative are improved.

The straight chain or branched alkylene group having 7 to 20 carbon atoms in R ^3a is preferably a straight chain alkylene group having 7 to 20 carbon atoms, from the viewpoint of obtaining a liquid crystal film with better rubber elasticity, and from the viewpoint of mechanical properties. Therefore, a linear alkylene group having 10 to 18 carbon atoms is more preferable, and a linear alkylene group having 12 carbon atoms is particularly preferable. Examples of the linear or branched alkylene group having 7 to 20 carbon atoms include heptamethylene group, octamethylene group, decamethylene group, dodecamethylene group, tetradecamethylene group, hexadecamethylene group, octadecamethylene group, etc. It will be done.
In addition, in a liquid crystal material containing a cellulose derivative in which R ^3a is a linear alkylene group having 12 carbon atoms, a phenomenon in which the molecular helix, which is the source of liquid crystallinity, is inverted (handedness inversion) was confirmed.

The straight chain or branched alkylene group having 3 to 20 carbon atoms in R ^3b is preferably a straight chain alkylene group having 3 to 20 carbon atoms, and preferably a straight chain alkylene group having 5 to 20 carbon atoms, from the viewpoint of obtaining a liquid crystal film with better rubber elasticity. A straight chain alkylene group having 15 carbon atoms is more preferred, and a straight chain alkylene group having 5 to 10 carbon atoms is even more preferred. Examples of straight chain or branched alkylene groups having 3 to 20 carbon atoms include n-propylene group, isopropylene group, n-butylene group, isobutylene group, sec-butylene group, tert-butylene group, n-pentylene group, Examples include isopentylene group, heptamethylene group, octamethylene group, decamethylene group, dodecamethylene group, tetradecamethylene group, hexadecamethylene group, octadecamethylene group.

In general formula (1) and general formula (1-1), R ¹¹ , R ¹² and R ¹³ are hydrophobic from the viewpoint of having liquid crystallinity and excellent rubber elasticity, and increasing the wavelength shift of the reflected wavelength. It is preferable to have both a straight-chain or branched acyl group having 2 to 4 carbon atoms and a group having an unsaturated double bond of general formula (3). It is more preferable to have.

The 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 0.01 or more and 2.0 or less. It is preferable.
Here, the degree of substitution refers to the degree to which at least some of the hydroxyl groups or a part of the hydroxyl groups among the three hydroxyl groups of the cellulose monomer unit (D-glucopyranose (β-glucose)) are substituted with a substituent. It is an index showing the degree of substitution, and specifically means the average number (≦3) of the above substituents.
The above-mentioned "degree of substitution of a group having an unsaturated double bond" means, when the cellulose derivative is represented by the general formula (1), the positions of R ¹¹ , R ¹² and R ¹³ in the general formula (1) The average number of "groups with unsaturated double bonds" introduced into
Similarly, the degree of substitution per monomer unit of a hydrophobic group (hereinafter also referred to as "degree of substitution of a hydrophobic group") means that when the cellulose derivative is represented by the general formula (1), the degree of substitution per monomer unit of the hydrophobic group is expressed by the general formula ( In 1), the average number of "hydrophobic groups" introduced at the positions of R ¹¹ , R ¹² and R ¹³ .
In addition, in this embodiment, in the case of a group having an unsaturated double bond and also falling under the category of a hydrophobic group, such a group is considered to be a "group having an unsaturated double bond."

The cellulose derivative can improve the expression of thermotropic cholesteric liquid crystallinity, and from the viewpoint of imparting excellent rubber elasticity to the cellulose derivative after crosslinking, the degree of substitution of the group having an unsaturated double bond is set to 0. It is preferably 0.01 or more and 2.0 or less, more preferably 0.1 or more and 1.5 or less, and even more preferably 0.2 or more and less than 1.0.
In addition, from the viewpoint of obtaining a liquid crystal film having appropriate rubber elasticity by crosslinking, the cellulose derivative has a ratio of the degree of substitution of groups having unsaturated double bonds to the degree of substitution of hydrophobic groups (unsaturated double bonds). The degree of substitution of a group having a bond/the degree of substitution of a 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 3.0 × 10 ^-2 or more and 1.0 or less. Preferably it is 7.0×10 ^-2 or more and 0.5 or less.

In the cellulose derivative, from the viewpoint of obtaining a liquid crystal film having appropriate rubber elasticity by crosslinking, the degree of substitution of the group having an unsaturated double bond represented by the general formula (3) is 0.01 or more and 1.0 or less. is preferable, more preferably 0.01 or more and 0.5 or less, even more preferably 0.01 or more and 0.1 or less.
In addition, from the viewpoint of obtaining a liquid crystal film having appropriate rubber elasticity by crosslinking, the cellulose derivative has a degree of substitution of a group having an unsaturated double bond represented by general formula (3) and a degree of substitution of a hydrophobic group. The ratio (degree of substitution of the group having an unsaturated double bond in general formula (3)/degree of substitution of the hydrophobic group) is preferably 3.0 × 10 ^-3 or more and 0.5 or less, more preferably It is 5.0×10 ⁻³ or more and 0.1 or less, and even more preferably 7.0×10 ⁻³ or more and 0.05 or less.

The degree of substitution of a group having an unsaturated double bond and the degree of substitution of a hydrophobic group are calculated from the integral value of the characteristic proton peak of each substituent by ¹ H-NMR.
Specifically, as shown in the examples below, the ¹ H-NMR spectrum of the cellulose derivative solution dissolved in deuterated chloroform was measured under the following measurement conditions, and based on the measured ¹ H-NMR spectrum, , proton peaks derived from groups with unsaturated double bonds; proton peaks derived from hydrophobic groups; proton peaks derived from cellulose skeleton (for example, proton peaks in β-glucose monomer units, etc.); cellulose skeleton is hydroxypropylcellulose In the case of (HPC), the proton peak derived from HPC is calculated based on the integral value of the proton peak of the methine group possessed by the hydroxypropyl group in the chain.
-Measurement condition-
Device: Made by BRUKER, ULTRASHIELD400PLUS (model number)
Frequency: 400MHz

The weight average molecular weight of the cellulose derivative is preferably from 20,000 to 200,000, more preferably from 50,000 to 200,000, and even more preferably from 100,000 to 200,000, from the viewpoint of obtaining a liquid crystal film with excellent rubber elasticity through crosslinking. It is less than 200,000.
The weight average molecular weight of the cellulose derivative can be calculated by gel permeation chromatography (GPC) (polystyrene standard) using a molecular weight calibration curve created using a polystyrene standard sample from the measurement results obtained under the following measurement conditions. It can be calculated by
-Measurement condition-
Equipment: Tosoh Corporation, HLC-8220GPC (model number)
Solvent: Tetrahydrofuran Column: 0021815 TSKgel SuperMultiporeHZ-N (particle size 3 μm, inner diameter 4.6 mm x length 15 cm, manufactured by Tosoh Corporation)
Flow rate: 0.15mL/min Sample concentration: 2.0% by mass
Injection volume: 10μL
Detector: Differential refraction detector Temperature: 40℃

The method for synthesizing the cellulose derivative is not particularly limited, and any method can be used to synthesize the cellulose derivative. Hereinafter, as an example of a method for synthesizing a cellulose derivative, a method for synthesizing a hydroxypropyl cellulose derivative having a molecular structure represented by general formula (1) will be described.

Hydroxypropylcellulose (HPC) is prepared as a starting material, and this HPC is dissolved in a solvent to prepare an HPC solution.
An HPC solution and at least one of a compound having a group having an unsaturated double bond (hereinafter also referred to as a "polymerizable compound") and a compound having a hydrophobic group (hereinafter also referred to as a "hydrophobic compound"). Mix.
Next, in this mixed solution, HPC is reacted with a polymerizable compound and a hydrophobic compound, and the hydrogen atoms of the three hydroxyl groups in the monomer unit of HPC are replaced with a group having an unsaturated double bond or a hydrophobic group. Substitution (introducing a group having an unsaturated double bond or a hydrophobic group to the side chain (end) of HPC). Note that it is preferable to mix the HPC solution with one of a polymerizable compound and a hydrophobic compound to introduce one into the side chain of HPC, and then mix the other and introduce the other into the side chain of HPC. Thereby, an HPC derivative having a molecular structure represented by general formula (1a) (an example of general formula (1)) is obtained.
In the above synthesis, for example, if hydroxyethyl cellulose is used as a starting material, a cellulose derivative having a molecular structure represented by general formula (1b) (an example of general formula (1)) can be obtained.

Further, by a method similar to the above method, a cellulose derivative having a molecular structure represented by general formula (1) can be obtained, for example, by the following method.
First, an alkylene group, -(R ¹⁴ -O) _h -(R ¹⁴ ;alkylene group, A cellulose derivative into which a linking group having h; an integer from 1 to 10) or -C(=O)-R ¹⁵ -(R ¹⁵ ; alkylene group) is introduced is prepared, and this is used as a starting material.
Next, the hydrogen atoms at the terminals of this cellulose derivative (starting material) are substituted with a group having an unsaturated double bond or a hydrophobic group by a method similar to the above method. Thereby, a cellulose derivative having a molecular structure represented by general formula (1) is obtained.

As the starting material (for example, HPC), either a synthesized material or a commercially available material may be used.
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; tetrahydrofuran; etc. Compounds (polymerizable compounds) having a group having an unsaturated double bond include is not particularly limited as long as it has the group having the aforementioned unsaturated double bond and the group having the unsaturated double bond can be introduced into R ¹¹ , R ¹² or R ¹³ in the above general formula (1). .
The compound having a hydrophobic group (hydrophobic compound) includes any compound having the above-mentioned hydrophobic group and which can be introduced into R ¹¹ , R ¹² or R ¹³ in the above general formula (1). There are no particular restrictions. Such hydrophobic compounds include acyl halides (for example, acyl chlorides (acetyl chloride, propionyl chloride, butyryl chloride, pentanoyl chloride, decanoyl chloride, etc.), acyl bromides (acetyl bromide, propionyl bromide, butyryl bromide, etc.), pentanoyl chloride, decanoyl bromide, etc.) are preferred, acyl chloride is more preferred, and acetyl chloride, propionyl chloride, and butyryl chloride are particularly preferred.

In the liquid crystal material of this embodiment, the ratio of the cellulose derivative to the entire liquid crystal material is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 99% by mass or more. More preferred. When the proportion of the cellulose derivative in the entire liquid crystal material is 80% by mass or more, the excellent rubber elasticity due to the cellulose derivative is further expressed, and the stretching properties of the liquid crystal material are further improved.

It is preferable that the liquid crystal material of this embodiment further contains a substituted or unsubstituted alkyl (meth)acrylate compound. When the liquid crystal material contains a substituted or unsubstituted alkyl (meth)acrylate compound, tensile strength is improved.
Here, "(meth)acrylate" refers to acrylate and methacrylate (the same applies hereinafter).
Further, in the substituted alkyl (meth)acrylate compound, examples of the substituent include a hydroxyl group, a halogen atom, and the like, and among these, a hydroxyl group is preferable.

The substituted or unsubstituted alkyl (meth)acrylate compounds include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, lauryl (meth)acrylate, and myristyl (meth)acrylate. , isomyristyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, n-octadecyl (meth)acrylate, hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl ( Examples include meth)acrylate, 3-hydroxypropyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, and the like.

Here, the substituted or unsubstituted alkyl (meth)acrylate compound is preferably substituted or unsubstituted butyl (meth)acrylate. When the liquid crystal material contains substituted or unsubstituted butyl (meth)acrylate, the strain at break of the liquid crystal material is further improved.
Furthermore, among the substituted or unsubstituted butyl (meth)acrylates, 4-hydroxybutyl acrylate is particularly preferred. When the liquid crystal material contains 4-hydroxybutyl acrylate, the restoring power of the liquid crystal material is further improved.

In the liquid crystal material of this embodiment, the ratio of the substituted or unsubstituted alkyl (meth)acrylate compound to the entire liquid crystal material is preferably 0 to 20% by mass, more preferably 1 to 15% by mass. It is preferably 5 to 15% by mass, and even more preferably 5 to 15% by mass. When the ratio of the substituted or unsubstituted alkyl (meth)acrylate compound to the entire liquid crystal material is 1% by mass or more, the effect of improving the tensile strength of the liquid crystal material becomes large.

The liquid crystal material of this embodiment may contain other components. Other components include, for example, polymerization initiators, fillers, crosslinking agents, flame retardants, compatibilizers, antioxidants, mold release agents (releasing agents), light stabilizers, weather resistant agents, modifiers, and antistatic agents. , hydrolysis inhibitors, etc. Among these, polymerization initiators, fillers, and crosslinking agents are preferred.

As the polymerization initiator, for example, known polymerization initiators such as thermal polymerization initiators and photopolymerization initiators can be used, and among these, photopolymerization initiators are preferred. Examples of the photopolymerization initiator include 2-hydroxy-2-methylpropiophenone (HMPP), acetophenone, 1-hydroxycyclohexylphenyl ketone, and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone. Piophenone, 2-methyl-4'-(methylthio)-2-morpholinopropiophenine, 2-benzyl-2-(dimethylmino)-4'-morpholinobutyrophenine, phenylbis(2,4,6-trimethyl Examples include benzoyl)phosphine oxide, bis(2,6-difluoro-3-(1-hydropyrrol-1-yl)phenyl)titanocene, and the like. In the liquid crystal material of this embodiment, the ratio of the polymerization initiator to the entire liquid crystal material is preferably 0 to 10% by mass, more preferably 0.01 to 5% by mass, and 0.1 to 3% by mass. It is even more preferable that it is mass %.
Examples of the filler include carbon black and silica. In the liquid crystal material of this embodiment, the proportion of the filler in the entire liquid crystal material is preferably 0 to 20% by mass, more preferably 0.1 to 10% by mass.
Examples of the crosslinking agent include polyisocyanates such as 1,6-hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and isophorone diisocyanate (IPDI). In the liquid crystal material of this embodiment, the ratio of the crosslinking agent to the entire liquid crystal material is preferably 0 to 5% by mass, more preferably 0.01 to 1% by mass.

The liquid crystal material of this embodiment preferably has an elongation at break of 50% or more, more preferably 55% or more, and even more preferably 60% or more. A liquid crystal material having an elongation at break of 50% or more can be used in applications requiring high stretching properties.
Further, although there is no particular restriction on the upper limit of elongation at break, the elongation at break of the liquid crystal material of this embodiment is usually 200% or less, and in one embodiment, 100% or less.
In addition, in this embodiment, the elongation at break is a value measured by the method described in Examples.

The liquid crystal material of this embodiment can be used in articles that require rubber elasticity, such as tires, hoses, conveyor belts, seismic isolation rubber, bridge seismic isolation rubber, bicycle tubes, tents, skis, rehabilitation equipment, and cables for home appliances. By using the liquid crystal material of this embodiment, these articles can be made to change color reversibly.
Furthermore, the liquid crystal material of the present invention can also be used as a material for a liquid crystal film, which will be described later.

［一般式（２）中、Ｘ²¹、Ｘ²²及びＸ²³は、それぞれ独立に、単結合、アルキレン基、－（Ｒ²⁴－Ｏ）_j－、又は－Ｃ（＝Ｏ）－Ｒ²⁵－を表し、Ｒ²¹、Ｒ²²及びＲ²³は、それぞれ独立に、水素原子、モノマー単位同士を連結する基を有する基、又は疎水性基を表し、Ｒ²⁴及びＲ²⁵は、それぞれ独立に、アルキレン基を表し、ｊは、１以上１０以下の整数を表し、ｎ２１は、２以上８００以下の整数を表す。但し、Ｒ²¹、Ｒ²²及びＲ²³の少なくとも１つは、下記一般式（４）：

（一般式（４）中、Ｒ^4aは、炭素数７～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^4bは、炭素数３～２０の直鎖若しくは分岐のアルキレン基を表し、Ｒ^4cは、水素原子又はメチル基を表し、＊は、モノマー単位同士が連結されたときの結合位置を表し、＊＊は、上記一般式（２）中、Ｘ²¹、Ｘ²²若しくはＸ²³と結合する部分、又はセルロース骨格の２位、３位若しくは６位にある酸素原子と結合する部分を表す。）で表されるモノマー単位同士を連結する基を有する基を表す。］で表される分子構造を有するセルロース誘導体を含むことを特徴とする。かかる本発明の液晶フィルムは、優れた延伸特性を有する。 <Liquid crystal film>
The liquid crystal film of this embodiment is
It has a three-dimensional structure,
General formula (2) below:

[In general formula (2), 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 each independently represent a hydrogen atom, a group having a group connecting monomer units, or a hydrophobic group, and R ²⁴ and R ²⁵ each independently represent an alkylene group. , j represents an integer from 1 to 10, and n21 represents an integer from 2 to 800. However, at least one of R ²¹ , R ²² and R ²³ has the following general formula (4):

(In general formula (4), R ^4a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^4b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^4c represents a hydrogen atom or a methyl group, * represents a bonding position when monomer units are connected to each other, and ** represents a bond to X ²¹ , X ²² or X ²³ in the above general formula (2) represents a group that has a group that connects monomer units represented by a moiety, or a moiety that binds to an oxygen atom at the 2nd, 3rd, or 6th position of the cellulose skeleton. ] It is characterized by containing a cellulose derivative having a molecular structure represented by the following. The liquid crystal film of the present invention has excellent stretching properties.

The liquid crystal film of this embodiment includes a cellulose derivative having a three-dimensional structure and a molecular structure represented by general formula (2), and the cellulose derivative includes a group having a group that connects monomer units with each other. .
A cellulose derivative having a three-dimensional structure (that is, a crosslinked structure) can be obtained by crosslinking monomer units derived from a cellulose derivative having a molecular structure represented by the above general formula (1).
Therefore, the cellulose derivative having a three-dimensional structure in this embodiment is one obtained by appropriately linking (crosslinking) monomer units with each other by a linking group generated by cleavage of an unsaturated double bond, that is, It is obtained by crosslinking a cellulose derivative polymer.
In this embodiment, the three-dimensional structure is considered to contribute to the development of rubber elasticity of the liquid crystal film. Cellulose derivatives having a three-dimensional structure have improved purification properties. This improvement in purification property is thought to contribute to the development of cholesteric liquid crystallinity and rubber elasticity of the liquid crystal film.
Therefore, the liquid crystal film of this embodiment has rubber elasticity, and furthermore, the orientation is fixed at the wavelength of Bragg reflection. Furthermore, by applying mechanical stress, reflected light of a wavelength corresponding to the stress is obtained.

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, since the liquid crystal film after crosslinking has a three-dimensional structure, it does not dissolve in a solvent (e.g., acetone), but the liquid crystal film before crosslinking, which does not have a three-dimensional structure (i.e., the liquid crystal material ) is dissolved in the solvent. The formation of a three-dimensional structure can be confirmed by comparing the presence or absence of solubility in a solvent in this way.
Further, the liquid crystal film of this embodiment can be manufactured by a relatively simple method because a three-dimensional structure is formed without using a crosslinking agent. Note that monomer units may be crosslinked using a crosslinking agent.
Moreover, although the liquid crystal film of this embodiment has a structure (three-dimensional structure) in which monomer units are crosslinked, this does not exclude crosslinking within the monomer units.

In general formula (2), 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 general formula (1) above, The same applies to preferred ranges.

In general formula (2), -(R ²⁴ -O) _j - represented by X ²¹ , X ²² and X ²³ or -C(=O)-R ²⁵ - in general formula (1) above is It has the same meaning as -(R ¹⁴ -O) _h - or -C(=O)-R ¹⁵ -, and the preferred ranges are also the same.

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

で表されるモノマー単位同士を連結する基を有する基である。 In general formula (2), the group having a group that connects the monomer units represented by R ²¹ , R ²² and R ²³ is a connecting group that is formed when the above-mentioned group having an unsaturated double bond is cleaved. It is. However, at least one of R ²¹ , R ²² and R ²³ has the following general formula (4):

It is a group having a group that connects monomer units represented by the following.

In the general formula (4), R ^4a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^4b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^4c represents a straight chain or branched alkylene group having 3 to 20 carbon atoms. , represents a hydrogen atom or a methyl group, * represents a bonding position when monomer units are connected to each other, and ** represents a moiety bonded to X ²¹ , X ²² or X ²³ in the above general formula (2) , or a moiety that bonds with the oxygen atom at the 2nd, 3rd, or 6th position of the cellulose skeleton.
In general formula (4), the straight chain or branched alkylene group having 7 to 20 carbon atoms represented by R ^4a is the linear or branched alkylene group having 7 to 20 carbon atoms represented by R ^3a in general formula (3) above. or a branched alkylene group, and the preferred ranges are also the same.
In the general formula (4) ^, R ^4b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms; It has the same meaning as the linear or branched alkylene group, and the preferred range is also the same.

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

で表される分子構造であることが好ましい。本実施形態の液晶フィルムが一般式（２－１）で表される分子構造を有するセルロース誘導体を含む場合、延伸特性が更に向上する。 The molecular structure represented by the above general formula (2) is the following general formula (2-1):

It is preferable that the molecular structure is represented by the following. When the liquid crystal film of this embodiment contains a cellulose derivative having a molecular structure represented by general formula (2-1), the stretching properties are further improved.

In general formula (2-1), R ² represents -CH ₂ -CH ₂ - or -CH ₂ -CH(CH ₃ )-, and R ²¹ , R ²² and R ²³ each independently represent hydrogen. Represents an atom, a group having a group that connects monomer units, or a hydrophobic group, m2, t2, and r2 each independently represent an integer of 0 to 10, and n21 represents an integer of 2 to 800. represent. However, at least one of R ²¹ , R ²² and R ²³ represents a group having a group connecting monomer units represented by the above general formula (4).

In general formula (2-1), R ²¹ , R ²² and R ²³ have the same meanings as R ²¹ , R ²² and R ²³ in general formula (2) above, and their preferred ranges are also the same.

In general formula (2-1), m2, t2, and r2 each independently represent an integer of 0 to 10, and m2, t2, and r2 are selected from the viewpoint of ease of synthesis of cellulose derivatives, respectively. Independently, preferably 0 or more and 8 or less, more preferably 0 or more and 5 or less, even more preferably 0 or more and 3 or less.

In the general formula (2-1), n21 has the same meaning as n21 in the above general formula (2), and the preferred range is also the same. n21 represents an integer of 2 or more and 800 or less, and is 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.

The liquid crystal film of this embodiment can be manufactured, for example, by applying the liquid crystal material of the above embodiment onto a substrate and applying heat or irradiating the liquid crystal material applied to the substrate with ultraviolet rays.
By this manufacturing method, it is possible to obtain a liquid crystal film that has rubber elasticity and has fixed Bragg reflection at a specific wavelength. Furthermore, by applying mechanical stress, it is possible to produce a liquid crystal film that can obtain reflected light of a wavelength corresponding to the stress.

The substrate is not particularly limited, and can be appropriately selected from commonly used substrates depending on the purpose. Examples of the substrate include glass substrates, plastic substrates (e.g., polyethylene naphthalate (PEN) substrates, polyethylene terephthalate (PET) substrates, polycarbonate (PC) substrates, polyimide (PI) substrates, etc.), aluminum substrates, stainless steel substrates, etc. 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 are preferably selected appropriately depending on the purpose.
Examples of methods for applying the liquid crystal material onto the substrate include coating methods such as spin coating, dipping, and spraying; inkjet methods; screen printing methods; and injection methods such as reduced pressure injection.

The form of the liquid crystal material may be solid (for example, powder) or liquid.
If the liquid crystal material is in a solid state, it may be mixed with a solvent to make it into a liquid state, and if the liquid crystal material is in a liquid state that can be applied to a substrate, it may be used as is, or it may be mixed with a solvent. You may use one whose viscosity is adjusted to be easy to mix and use.

The liquid crystal material applied to the substrate may also contain other components. Other components include the same components as those described above (eg, polymerization initiator, release agent).
The solvent is not particularly limited, and for example, the solvents exemplified in the section of the cellulose derivative synthesis method described above can be used.

When heat is applied to the liquid crystal material provided on the substrate, the unsaturated double bonds that the cellulose derivative had before crosslinking are cleaved and the monomer units are linked together via linking groups. (crosslinked), and as a result, rubber elasticity is developed. Furthermore, the orientation is fixed at the wavelength of Bragg reflection.
The method of applying heat is not particularly limited, and examples thereof include a method of applying heat using a known heating device (oven, infrared heater, hot plate, etc.).
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. The temperature is 120°C or less, and even more preferably 25°C or more and 110°C or less. Note that the temperature when applying heat to the liquid crystal material is controlled so that the temperature of the liquid crystal material falls within the above range.
Note that by controlling the heat application conditions (temperature, heating time, etc.), the orientation can be easily fixed at the wavelength of Bragg reflection.

When a liquid crystal material provided on a substrate is irradiated with ultraviolet rays, the unsaturated double bonds that the cellulose derivative had before crosslinking are cleaved, and the monomer units are bonded to each other via linking groups. and are linked (crosslinked), resulting in rubber elasticity. Furthermore, the orientation is fixed at the wavelength of Bragg reflection.
The temperature at which the liquid crystal material is irradiated with ultraviolet light (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 even more preferably 25°C or higher. The temperature is 110°C or less. Note that the temperature at which the liquid crystal material is irradiated with ultraviolet rays is controlled so that the temperature of the liquid crystal material falls within the above range.
Further, the irradiation intensity of ultraviolet rays (UV illuminance) (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. , and even more preferably 10 mW/cm ² or more and 20 mW/cm ² or less.
In ultraviolet irradiation, by controlling the UV irradiation temperature and UV irradiation intensity in combination, a liquid crystal film whose orientation is fixed by different Bragg reflections can be obtained.
More specifically, by controlling the UV irradiation temperature within the above range, the thermotropic cholesteric liquid crystallinity of the cellulose derivative is expressed, making it easier to adjust the desired color and obtain the desired color. Then, by controlling the UV irradiation temperature within the above range and further controlling the UV irradiation intensity within the above range, the color obtained by the UV irradiation temperature is fixed.
Therefore, in the above ultraviolet irradiation, by controlling both the UV irradiation temperature and the UV irradiation intensity (preferably the UV irradiation time), a multicolored liquid crystal film that exhibits the desired color at the desired location can be obtained.
Note that such a multicolored liquid crystal film (that is, a film with fixed orientations in different Bragg reflections) can be easily obtained by using, for example, a photomask. Details will be described later.

The liquid crystal film of this embodiment preferably has an elongation at break of 50% or more, more preferably 55% or more, and even more preferably 60% or more. A liquid crystal film having an elongation at break of 50% or more can be used in applications requiring high stretching properties.
Further, there is no particular restriction on the upper limit of elongation at break, but the elongation at break of the liquid crystal film of this embodiment is usually 200% or less, and in one embodiment, 100% or less.

The liquid crystal film of this embodiment is, for example, an optical film such as a polarizing film, a retardation film, a backlight, an antireflection film, a light diffusion film, a brightness enhancement film, an anti-glare film; distortion of an object, expansion/contraction, vibration, impact, etc. Sensors (pressure sensors, strain sensors, stretch sensors, vibration sensors, impact sensors, etc.) that detect deformation caused by reflection using reflected wavelengths (preferably reflected colors); , a wearable sensor that detects by the reflected wavelength (preferably reflected color); an optical element using the above optical film; an optical element other than the above; a liquid crystal display element; etc.
The liquid crystal film of this embodiment has rubber elasticity, and by applying mechanical stress, it is possible to obtain reflected light with a wavelength corresponding to the applied stress. It is preferable to use the sensor by mounting it on a sensor capable of detecting , or an optical element capable of obtaining reflected light by applying mechanical stress.

<Sensor>
The sensor of this embodiment is characterized by comprising the above-mentioned liquid crystal film. The sensor of this embodiment has excellent stretching properties.
As the sensor, for example, a strain sensor, a wearable sensor, etc. are preferable.

The sensor of this embodiment is preferably a distortion sensor that detects distortion of an object.
Since the strain sensor of this embodiment includes the above-mentioned liquid crystal film, it is possible to detect deformation caused by distortion of an object based on the wavelength of reflection (preferably the color of reflection).
For example, by installing the strain sensor of this embodiment in advance at a location on an object where distortion is likely to occur (for example, a structure such as a bridge or a building), the degree of distortion of the object can be detected. Further, the mechanical stress caused by the distortion (deformation) can be detected visually, that is, by the wavelength of reflection (preferably the color of reflection).

The sensor of this embodiment is preferably a wearable sensor that detects biological information. Wearable sensors are relatively small sensors that can be worn on the body.
Since the wearable sensor of this embodiment includes the above-mentioned liquid crystal film, biological information can be detected by the wavelength of reflection (preferably the color of reflection).
For example, the strain sensor of this embodiment may be attached or worn directly (for example, on the skin) to a location where biological information is to be obtained, or clothing, underwear, socks, gloves, ties, handkerchiefs, mufflers, watches, glasses, etc. By pasting or wearing it on shoes, slippers, hats, etc., biological information (pulse waves, breathing, ballistocardial motion, body movements (muscle movements, etc.), etc.) can be visually detected, that is, reflected wavelengths (preferably reflection color).

<Optical element>
The optical element of this embodiment is characterized by comprising the above liquid crystal film. The optical element of this embodiment has excellent stretching properties.
By applying mechanical stress artificially or installing the optical element of this embodiment in advance at a location where mechanical stress is naturally applied, for example, different reflected light corresponding to the stress can be obtained. Applications of such optical elements include toys, emergency light sources, interior decorations (ornaments, shelves, etc.), architectural components (floors, walls, stairs, etc.), tableware, containers, and the like.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to the Examples below.

<Synthesis of cellulose derivative 1>
In a flask sealed with aluminum foil and filled with nitrogen, 5.5 mL (34 mmol) of hexamethylene diisocyanate (manufactured by Tokyo Kasei Kogyo Co., Ltd., product number: H0324) and 4-hydroxybutyl acrylate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) were added. ), product number: A1390) was added thereto, and the mixture was stirred for 24 hours. After dissolving 300 mg of the product in 3.0 mL of chloroform, 4-(((6-isocyanatohexyl)carbamoyl)oxyl) was analyzed by HPLC (manufactured by Nippon Analytical Industry Co., Ltd., product name: Recycle Preparative HPLC device). Butyl acrylate (4H) was separated and chloroform was removed by evaporation.
Low molecular weight hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name: Hydroxypropylcellulose 2.0 to 2.9, product number: 082) dried at room temperature (25°C) for 24 hours or more under reduced pressure -07925, weight average molecular weight: 5.0×10 ⁴ ) was dissolved in 110 mL of ultra-dehydrated acetone in a flask filled with nitrogen, and heated ( 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 the mixture was stirred for 20 hours.
Next, under room temperature (25° C.) conditions, 15 mL (172 mmol) of propionyl chloride (PrCl) was added and stirred for 24 hours, and then the reaction solution was added dropwise to ultrapure water. After redissolving it in special grade acetone and repeating the washing operation by dropping it into ultrapure water three times, the product, Cellulose Derivative 1 (HPC-4HC/PrE), was obtained by drying under reduced pressure for one day or more.
The yield was 4.0g. A reaction scheme is shown below.

(Measurement of ¹ H-NMR spectrum)
The ¹ H-NMR spectra of 4H and cellulose derivative 1 (HPC-4HC/PrE) synthesized above were measured.
Regarding 4H, the peaks around 5.8 ppm, 6.1 ppm, and 6.4 ppm are the peaks of protons attached to the double bond of the terminal acryloyl group, respectively, and the peak around 4.8 ppm is the peak of the amino group in the carbamate bond. This is the proton peak. The peaks around 4.2 ppm and 3.2 ppm are the peaks of protons of four methylene groups derived from 4-hydroxybutyl acrylate, and the peaks around 1.2 ppm to 1.8 ppm are derived from hexamethylene diisocyanate. These are the proton peaks of the six methylene groups.
Regarding cellulose derivative 1 (HPC-4HC/PrE), the peaks around 5.8 ppm, 6.1 ppm, and 6.4 ppm are the peaks of protons attached to the double bond of the terminal acryloyl group, respectively, and the peaks around 5.0 ppm The peak is the proton peak of the methine group of the terminal hydroxypropionyl group. The peak around 1.0 ppm to 2.5 ppm is the methyl group of the hydroxypropyl group in the HPC side chain, the oxygen atom of 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, the proton of the methylene group. The peak around 2.7 ppm to 4.6 ppm is the peak of other protons that cellulose derivative 1 has.
Based on the assigned peaks, the degree of substitution to a group having an unsaturated double bond (i.e., 4HC group) and the substitution degree to a hydrophobic group (i.e., propionyl group) in the HPC side chain (hydrogen atom in the hydroxyl group) is determined. The degree of substitution was calculated.
As a result, in cellulose derivative 1 (HPC-4HC/PrE), the degree of substitution to the 4HC group (group having an unsaturated double bond) was 0.024, and the degree of substitution to the propionyl group (hydrophobic group) was 0.024. It was 2.75.

<Synthesis of cellulose derivative 2>
In a flask sealed with aluminum foil and filled with nitrogen, 5.0 g (24.7 mmol) of 1,12-dodecanediol (manufactured by Tokyo Chemical Industry Co., Ltd., product number: D0969) and dehydrated THF (manufactured by Kanto Kagaku Co., Ltd.) were added. (product number: 40993-05) was added, heated to 35°C, and stirred for 10 minutes to dissolve. A dilute solution prepared by adding 20 mL of dehydrated THF to 1.7 mL (21.0 mmol) of acryloyl chloride (manufactured by Tokyo Kasei Kogyo Co., Ltd., product number: A0147) was added dropwise to this over about 2 hours, and then at room temperature (25 ℃) for 24 hours. After THF was distilled off by evaporation, a small amount of hexane was added and filtered, and further hexane was distilled off by evaporation to obtain a transparent liquid A containing 12-hydroxydodecyl acrylate as the main product. .
In a flask sealed with aluminum foil and filled with nitrogen, 4.7 mL (29.3 mmol) of hexamethylene diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd., product number: H0324) and 8.0 mL of dehydrated chloroform (manufactured by Kanto Kagaku Co., Ltd.) were added. Co., Ltd., product number: 08097-05), 1.9 mL of the transparent liquid A synthesized above was added dropwise, and the mixture was stirred for 24 hours. After dissolving 300 mg of the product in 3.0 mL of chloroform, 12-(((6-isocyanatohexyl)carbamoyl)oxyl ) Dodecyl acrylate (12H) was separated and chloroform was removed by evaporation.
Hydroxypropylcellulose (HPC) (manufactured by Wako Pure Chemical Industries, Ltd., product name: Hydroxypropylcellulose 2.0 to 2.9, product number: 082-07925) dried under reduced pressure at room temperature (25°C) for 24 hours or more , weight average molecular weight: 5.0×10 ⁴ ) was dissolved in 90 mL of dehydrated acetone (manufactured by Kanto Kagaku Co., Ltd., product number: 01866-05) in a flask filled with nitrogen. Thereafter, the mixture was heated to 47° C. while shielded from light with aluminum foil, 10.0 mL of dehydrated acetone in which 380 mg (0.89 mmol) of 12H synthesized above was dissolved was added, and the mixture was stirred for 20 hours.
Next, under room temperature (25° C.) conditions, 20 mL (229 mmol) of propionyl chloride (PrCl) was added and stirred for 24 hours, and then the reaction solution was added dropwise to ultrapure water. The cellulose derivative 2 (HPC-12HC/PrE), which is a product, was obtained by redissolving it in special grade acetone and repeating the washing operation three times by dropping it into ultrapure water, and then drying it under reduced pressure for one day or more. The yield was 4.0g. A reaction scheme is shown below.

(Measurement of ¹ H-NMR spectrum)
The ¹ H-NMR spectra of 12H and cellulose derivative 2 (HPC-12HC/PrE) synthesized above were measured.
Regarding 12H, the peaks around 5.8 ppm, 6.1 ppm, and 6.4 ppm are the peaks of protons attached to the double bond of the terminal acryloyl group, respectively, and the peak around 4.8 ppm is the peak of the amino group in the carbamate bond. This is the proton peak. The peaks around 4.2 ppm and 3.2 ppm are the peaks of protons of 12 methylene groups derived from 12-hydroxydodecyl acrylate, and the peaks around 1.2 ppm to 1.8 ppm are the peaks of protons of 12 methylene groups derived from 12-hydroxydodecyl acrylate. This is the proton peak of the six derived methylene groups.
Regarding cellulose derivative 2 (HPC-12HC/PrE), the peaks around 5.8 ppm, 6.1 ppm, and 6.4 ppm are the peaks of protons attached to the double bond of the terminal acryloyl group, respectively, and the peaks around 5.0 ppm The peak is the proton peak of the methine group of the terminal hydroxypropionyl group. The peak around 1.0 ppm to 2.5 ppm is the methyl group of the hydroxypropyl group in the HPC side chain, the oxygen atom of 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, the proton of the methylene group. The peaks around 2.7 ppm to 4.6 ppm are peaks of other protons possessed by cellulose derivative 2.
Based on the assigned peaks, the degree of substitution to a group having an unsaturated double bond (i.e., 12HC group) and the substitution degree to a hydrophobic group (i.e., propionyl group) in the HPC side chain (hydrogen atom in the hydroxyl group) is determined. The degree of substitution was calculated.
As a result, in cellulose derivative 2 (HPC-12HC/PrE), the degree of substitution to the 12HC group (group having an unsaturated double bond) was 0.024, and the degree of substitution to the propionyl group (hydrophobic group) was 0.024. It was 2.71.

<Synthesis of cellulose derivative 3>
In "Synthesis of cellulose derivative 1", cellulose derivatives 3 (HPC-4HC/PrE) having different degrees of substitution of 4HC groups were synthesized by changing the amount of 4H added. The obtained cellulose derivative 3 (HPC-4HC/PrE) has a degree of substitution of 4HC groups (groups having an unsaturated double bond) of 0.023, and a degree of substitution of propionyl groups (hydrophobic groups) of 0.023. It was 2.58.

[Examples 1-2 and Comparative Examples 1-2]
<Preparation of liquid crystal material>
Cellulose derivatives 1 to 3 synthesized as described above and 4-hydroxybutyl acrylate (manufactured by Tokyo Kasei Kogyo Co., Ltd., product name: 4-hydroxybutyl acrylate, product) according to the formulations shown in Tables 1 to 3. No.: A1390) (4HBA) and 2-hydroxy-2-methylpropiophenone (manufactured by Tokyo Kasei Kogyo Co., Ltd., product number: H0991) (HMPP) as a photopolymerization initiator are stirred and mixed, A liquid crystal material (lyotropic liquid crystal) was prepared.

<Preparation of liquid crystal film>
The prepared liquid crystal material (lyotropic liquid crystal) was sandwiched with a 500 μm thick PTFE spacer in a glass cell with a release sheet attached, and left to stand overnight for orientation. : 365 nm, intensity: 10 mW/cm ² ) for 1 hour to produce a liquid crystal film.

(1) Tensile test A JIS-7 dumbbell test piece was prepared from the obtained liquid crystal film, and tested at room temperature (25°C) using a small tabletop testing machine (manufactured by Shimadzu Corporation, product name: EZ-LX). ), a tensile test was conducted at a tensile speed of 10 mm/min. The elastic modulus, tensile strength (maximum point stress), and elongation at break of each liquid crystal film are shown in Tables 1 to 3. Furthermore, FIG. 1 shows the stress-strain curves during the stretching process of the liquid crystal films of Example 1 and Comparative Example 1, and FIG. 2 shows the stress-strain curves during the stretching process of the liquid crystal films of Example 1 and Example 2. 3 shows stress-strain curves during the stretching process of the liquid crystal films of Example 2 and Comparative Example 2.

Tables 1 and 3 show that the liquid crystal materials of Examples 1 and 2 according to the present invention have greater elongation at break and superior flexibility in the stretching direction than the liquid crystal materials of Comparative Examples 1 and 2.
Further, from a comparison between Example 1 and Example 2 in Table 2, it can be seen that when the liquid crystal material contains a substituted or unsubstituted alkyl (meth)acrylate compound, the elastic modulus increases.

(2) Wavelength shift change during compression After measuring the film thickness of the liquid crystal film of Example 2 using a caliper, the film thickness was measured using a compression tuning cell and the strain (ε) was 0, 0.06, 0. 13 and 0.17, the liquid crystal film was compressed in the thickness direction. By measuring the transmission spectrum at each strain (ε) using a compact fiber multichannel spectrometer (manufactured by Ocean Optics, model number: USB-4000), the change in wavelength shift during compression was measured. FIG. 4(a) shows the change in the transmission spectrum during the compression-release process, and FIG. 4(b) shows the state of the liquid crystal film during the compression-release process.

(3) Wavelength shift change during stretching For the liquid crystal film of Example 2, the strain (ε) was 0, 0.04, 0.08, 0.12, 0.15, 0.23, 0.30. The change in wavelength shift during stretching was measured by stretching the liquid crystal film in the longitudinal direction and measuring the reflection spectrum at each strain (ε) in the same manner as the measurement of the transmission spectrum. FIG. 5(a) shows the change in the reflection spectrum during the stretching and releasing process, and FIG. 5(b) shows the state of the liquid crystal film during the stretching and releasing process.

From the results of the changes in the transmission spectrum during the compression-release process shown in Figures 4(a) and (b) and the changes in the reflection spectrum during the stretching-release process shown in Figures 5(a) and (b), it was found that the compression-release It can be seen that the color change of the liquid crystal film of Example 2 is reversible in both the stretching and releasing processes.

(4) Stretching and contraction durability The liquid crystal film of Example 2 was stretched and released 1000 times in the longitudinal direction of the liquid crystal film at a strain (ε) of 0.15, and the stress-strain curve and reflection at each cycle were The spectrum was measured. FIG. 6(a) shows stress-strain curves for each cycle (1st, 2nd, 100th, and 1000th cycles). In addition, FIG. 6(b) shows the results of the peak wavelength of the reflection spectrum during stretching and releasing in each cycle (1st, 2nd, 3rd, and 100th cycle), and FIG. 6(c) shows the results of the peak wavelength of the reflection spectrum in each cycle Shows how the film looks.

From FIG. 6(a), it can be seen that the stress-strain curve of the liquid crystal film of Example 2 shows little change between the 1st cycle and the 1000th cycle, indicating that the liquid crystal film of Example 2 can be reversibly expanded and contracted. .
Further, from FIGS. 6(b) and 6(c), it can be seen that the color change of the liquid crystal film of Example 2 is reversible even after 100 cycles of expansion and contraction.

[Example 3 and 4]
<Synthesis of cellulose derivative 4>
In "Synthesis of cellulose derivative 2", cellulose derivatives 4 (HPC-12HC/PrE) having different degrees of substitution of the 12HC group were synthesized by changing the amount of 12H added. In the obtained cellulose derivative 4 (HPC-12HC/PrE), the degree of substitution to the 12HC group (group having an unsaturated double bond) is 0.010, and the degree of substitution to the propionyl group (hydrophobic group) is 0.010. It was 2.53.

<Preparation of liquid crystal material>
Using the cellulose derivative 4 synthesized as described above, 4-hydroxybutyl acrylate (4HBA), and 2-hydroxy-2-methylpropiophenone (HMPP), a liquid crystal material was prepared according to the formulation shown in Table 4. was prepared, and a liquid crystal film was produced in the same manner as in Example 1.

(1) Tensile test The obtained liquid crystal film was subjected to a tensile test in the same manner as in Example 1. FIG. 7 shows a stress-strain curve during the stretching process of the liquid crystal film. Table 4 also shows the elastic modulus, tensile strength, and elongation at break of each liquid crystal film.

A comparison between Example 3 and Example 4 shows that when the liquid crystal material contains a substituted or unsubstituted alkyl (meth)acrylate compound, the elastic modulus and tensile strength are increased.
Furthermore, from the comparison between Example 3 and Example 1 and the comparison between Example 4 and Example 2, the amount of the group having an unsaturated double bond (crosslinking group) represented by the general formula (3) was determined. It can be seen that by reducing the amount, the flexibility in the stretching direction is further improved.

(2) Change in reflection wavelength during stretching and application to sensor JIS-7 dumbbell test pieces were prepared from the liquid crystal film of Example 4, and changes in reflection wavelength during stretching were measured. The results are shown in FIG. 8(a).
In addition, changes in reflection wavelength were measured when the liquid crystal film of Example 4 was pressed against each of a 500 yen coin, a 100 yen coin, and a 1 yen coin. The results are shown in FIG. 8(b).

From FIG. 8(a), it can be seen that the reflection wavelength of the liquid crystal film of Example 4 changes depending on the degree of stretching.
Further, from FIG. 8(b), it can be seen that the liquid crystal film of Example 4 is capable of sensing minute irregularities on the coin surface by utilizing the characteristic that the reflection wavelength changes depending on the degree of stretching.

[Examples 5 to 9]
<Synthesis of cellulose derivatives 5 and 6>
In "Synthesis of cellulose derivative 2", cellulose derivatives 5 and 6 (HPC-12HC/PrE) having different degrees of substitution of the 12HC group were synthesized by changing the amount of 12H added. In the obtained cellulose derivative 5 (HPC-12HC/PrE), the degree of substitution to the 12HC group (group having an unsaturated double bond) is 0.013, and the degree of substitution to the propionyl group (hydrophobic group) is 0.013. 2.80, and cellulose derivative 6 (HPC-12HC/PrE) has a substitution degree of 12HC group (group having an unsaturated double bond) of 0.014, and a propionyl group (hydrophobic group). The degree of substitution was 2.74.

<Preparation of liquid crystal material>
Cellulose derivatives 5 or 6, 4-hydroxybutyl acrylate (4HBA), 2-hydroxy-2-methylpropiophenone (HMPP), carbon black (manufactured by Mitsubishi Chemical, product number: #2650) synthesized as described above ( Table 5 and A liquid crystal material was prepared according to the formulation shown in Table 6, and a liquid crystal film was produced in the same manner as in Example 1.

(1) Tensile test The obtained liquid crystal film was subjected to a tensile test in the same manner as in Example 1. Tables 5 and 6 show the elastic modulus, tensile strength, and elongation at break of each liquid crystal film. Further, FIG. 9 shows stress-strain curves during the stretching process of the liquid crystal films of Examples 5 and 6, and FIG. 10 shows stress-strain curves during the stretching process of the liquid crystal films of Examples 7 to 9.

Tables 5 and 6 show that the liquid crystal material of the present invention can maintain excellent stretching properties even if it contains fillers such as carbon black and silica.
Moreover, from the results of Example 9 in Table 6, it can be seen that the elastic modulus of the liquid crystal material of the present invention is improved by containing polyisocyanate.

(2) Handivity reversal Inject white light of right-handed circularly polarized light (R-CPL) and left-handed circularly polarized light (L-CPL) into the liquid crystal film of Example 7, and measure the change in transmission spectrum during the stretching-release process. did. Figure 11(a) shows the transmission spectrum change during the stretching-release process when right-handed circularly polarized (R-CPL) white light is incident, and Figure 11(b) shows the transmission spectrum change in left-handed circularly polarized (L-CPL) white light. It shows the change in transmission spectrum during the stretching-release process when white light is incident.

As shown in FIG. 11(a), as the film was stretched, the reflection peak derived from right-handed circularly polarized light (R-CPL) shifted to shorter wavelengths and its peak intensity became smaller. On the other hand, as shown in FIG. 11(b), when left-handed circularly polarized light (L-CPL) is irradiated, a reflection peak appears with stretching, and the peak intensity at strain (ε) = 0.15 is The left circularly polarized light (L-CPL) was larger than the circularly polarized light (R-CPL). Furthermore, when the liquid crystal film was released, the reflection wavelength not only shifted to the longer wavelength side, but also the reflection peak derived from left-handed circularly polarized light (L-CPL) was attenuated and completely disappeared in the initial state. On the other hand, when we measured the transmission spectrum change during the compression-release process in the thickness direction of the liquid crystal film, no handedness reversal occurred. From these results, it was confirmed that the liquid crystal film of this embodiment has a unique property in which handedness reversal occurs only upon stretching.

[Examples 10 to 12]
<Synthesis of cellulose derivative 7>
In "Synthesis of Cellulose Derivative 2", cellulose derivative 7 (HPC-12HC/PrE) having different degrees of substitution of the 12HC group was synthesized by changing the amount of 12H added. The obtained cellulose derivative 7 (HPC-12HC/PrE) has a degree of substitution of 12HC groups (groups having an unsaturated double bond) of 0.010, and a degree of substitution of propionyl groups (hydrophobic groups) of 0.010. It was 2.74.

<Preparation of liquid crystal material>
Cellulose derivative 7 synthesized as above, 4-hydroxybutyl acrylate (4HBA), butyl acrylate (BA) (manufactured by Tokyo Kasei Kogyo Co., Ltd., product number: A0142) or 2-hydroxyethyl methacrylate (HEMA) ( A liquid crystal material was prepared according to the formulation shown in Table 7 using 2-hydroxy-2-methylpropiophenone (manufactured by Tokyo Kasei Kogyo Co., Ltd., product number: M0085) and 2-hydroxy-2-methylpropiophenone (HMPP). A liquid crystal film was produced in the same manner.

(1) Tensile test The obtained liquid crystal film was subjected to a tensile test in the same manner as in Example 1. Table 7 shows the elastic modulus, tensile strength, and elongation at break of each liquid crystal film. Further, FIG. 12 shows stress-strain curves during the stretching process of the liquid crystal films of Examples 10 to 12.

Table 7 shows that when the liquid crystal material contains substituted or unsubstituted butyl (meth)acrylate, the breaking strain of the liquid crystal material is further improved, and when the liquid crystal material contains 4-hydroxybutyl acrylate, the restoring force of the liquid crystal material is further improved. It can be seen that the results are improved.

[Example 13]
<Synthesis of cellulose derivative 8>
In "Synthesis of cellulose derivative 2", cellulose derivatives 8 (HPC-12HC/PrE) having different degrees of substitution of 12HC groups were synthesized by changing the amount of introduced 12H to be added. In the obtained cellulose derivative 8 (HPC-12HC/PrE), the degree of substitution to the 12HC group (group having an unsaturated double bond) is 0.017, and the degree of substitution to the propionyl group (hydrophobic group) is 0.017. It was 2.73.

<Preparation of liquid crystal material>
Using cellulose derivative 8, 4-hydroxybutyl acrylate (4BHA) and 2-hydroxy-2-methylpropiophenone (HMPP) synthesized as described above, except that the cellulose derivative used was not cellulose derivative 4. A liquid crystal material was prepared according to the formulation shown in Table 4, and a liquid crystal film was produced in the same manner as in Example 1.

(1) Biaxial stretching test A test piece of 40 mm x 30 mm x 0.5 mm was prepared from the obtained liquid crystal film, and an XY stage (manufactured by Sigma Koki Co., Ltd., product number: TSD-602) was combined. Using the biaxial stretching tester shown in FIG. 13, white light of right-handed circularly polarized light (R-CPL) and left-handed circularly polarized light (L-CPL) was incident, and changes in transmission spectrum during the biaxial stretching process were measured. The results are shown in FIGS. 14 and 15.

As can be seen from FIG. 14(a), in the case of uniaxial stretching as in paragraph [0127], the reflection peak derived from right-handed circularly polarized light (R-CPL) shifts to shorter wavelengths as the stretching progresses, and the peak intensity increases. While the reflection peak derived from left-handed circularly polarized light (L-CPL) shifted to shorter wavelengths, a handedness reversal occurred in which the peak intensity increased. No handedness reversal occurred.
FIG. 14(b) shows the change in the transmission spectrum when the fixation of the liquid crystal film during biaxial stretching is removed in one direction and uniaxial stretching is performed. When the liquid crystal film was uniaxially stretched, handedness reversal occurred as in paragraph [0127].
From these results, it was confirmed that the liquid crystal film of this embodiment has the property that handedness reversal occurs only in uniaxial stretching and does not occur in biaxial stretching.

As can be seen from FIG. 15(a), when the liquid crystal film was stretched by biaxial stretching, the shift width was wider than the short wavelength shift caused by uniaxial stretching as shown in FIG.
Further, from FIG. 15(b), it was found that, similarly to FIG. 14, no handedness reversal occurred in biaxial stretching.
From these results, by stretching the liquid crystal film of this embodiment, it became possible to exhibit red, green, and blue reflected colors derived from right-handed circularly polarized light (R-CPL).

FIG. 16 shows how the liquid crystal film changes color during the biaxial stretching process. It was confirmed that the color of the area where the stretching force was applied changed significantly, and that when less stretching force was applied, the degree of discoloration was smaller than that near the center.

The liquid crystal material of the present invention can be used in rubbers such as tires, hoses, conveyor belts, seismic isolation rubber, bridge seismic isolation rubber, bicycle tubes, various grips, tents, sports equipment such as skis, mats, rehabilitation products, and cables for home appliances. Can be used for items that require elasticity. In particular, by mounting the liquid crystal material of the present invention on the sidewall of a tire, the design of the tire can be improved, and the liquid crystal material can also be used as a pressure sensor or a deterioration indicator.
Further, the liquid crystal film of the present invention can be used in various sensors and optical elements.

Claims (10)

General formula (1) below:

[In general formula (1), 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 represent a hydrogen atom, a group having an unsaturated double bond , an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 20 carbon atoms, and a group having 6 to 20 carbon atoms. 24 aryl group, an aralkyl group having 7 to 20 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, -COOR ^1A (here, R ^1A is a linear or branched alkyl group having 1 to 12 carbon atoms, a carbon number represents a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 18 carbon atoms, or a halogen atom, R 14 and ^{R 15} each independently represent an alkylene group, and h represents an integer of 1 or more and 10 or less, and n11 represents an integer of 2 or more and 800 or less. However, at least one of R ¹¹ , R ¹² and R ¹³ has the following general formula (3):

(In general formula (3), R ^3a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^3b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^3c represents a hydrogen atom or ^a methyl group, and ** represents a moiety bonding to X ¹¹ , X ¹² or represents a group having an unsaturated double bond represented by ] A liquid crystal material characterized by containing a cellulose derivative having a molecular structure represented by the following. The molecular structure represented by the above general formula (1) is the following general formula (1-1):

[In general formula (1-1), R ¹ represents -CH ₂ -CH ₂ - or -CH ₂ -CH(CH ₃ )-, and R ¹¹ , R ¹² and R ¹³ are each independently, Hydrogen atom, group having an unsaturated double bond, alkyl group having 1 to 18 carbon atoms, acyl group having 2 to 20 carbon atoms, aryl group having 6 to 24 carbon atoms, aralkyl group having 7 to 20 carbon atoms, carbon number 1-18 alkoxy group, -COOR ^1A (here, R ^1A is a straight-chain or branched alkyl group having 1-12 carbon atoms, a cycloalkyl group having 3-12 carbon atoms, or an aryl group having 6-18 carbon atoms) represents a group represented by ) or a halogen atom , m1, t1 and r1 each independently represent an integer of 0 to 10, and n11 represents an integer of 2 to 800. However, at least one of R ¹¹ , R ¹² and R ¹³ is represented by the following general formula (3):

(In general formula (3), R ^3a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^3b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^3c represents a hydrogen atom or a methyl group, and ** represents -(R ¹ -O) _m1 -, -(R ¹ -O) _t1 - or -(R ¹ -O) in the above general formula (1-1). ) Represents a group having an unsaturated double bond represented by () represents a moiety that binds to _r1 - or a moiety that binds to an oxygen atom at the 2nd, 3rd, or 6th position of the cellulose skeleton. The liquid crystal material according to claim 1, which has a molecular structure represented by the following. The liquid crystal material according to claim 1 or 2 , which has an elongation at break after polymerization of 50% or more, as measured by a tensile test at 25° C. and a tensile speed of 10 mm/min . The liquid crystal material according to any one of claims 1 to 3, further comprising a substituted or unsubstituted alkyl (meth)acrylate compound. 5. The liquid crystal material according to claim 4, wherein the substituted or unsubstituted alkyl (meth)acrylate compound is substituted or unsubstituted butyl (meth)acrylate. The liquid crystal material according to claim 5, wherein the substituted or unsubstituted butyl (meth)acrylate is 4-hydroxybutyl acrylate. It has a three-dimensional structure,
General formula (2) below:

[In general formula (2), 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 each independently represent a hydrogen atom, a group having a group that connects monomer units, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 20 carbon atoms, and a carbon number Aryl group having 6 to 24 carbon atoms, aralkyl group having 7 to 20 carbon atoms, alkoxy group having 1 to 18 carbon atoms, -COOR 1A (herein, R 1A is a linear or branched alkyl group having ¹ to ¹² carbon atoms, represents a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 18 carbon atoms, or a halogen atom, and R 24 and ^{R 25} each independently represent an alkylene group. , j represent an integer of 1 or more and 10 or less, and n21 represents an integer of 2 or more and 800 or less. However, at least one of R ²¹ , R ²² and R ²³ has the following general formula (4):

(In general formula (4), R ^4a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^4b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^4c represents a hydrogen atom or a methyl group, * represents a bonding position when monomer units are connected to each other, and ** represents a bond to X ²¹ , X ²² or X ²³ in the above general formula (2). represents a group that has a group that connects monomer units represented by a moiety, or a moiety that binds to an oxygen atom at the 2nd, 3rd, or 6th position of the cellulose skeleton. ] A liquid crystal film comprising a cellulose derivative having a molecular structure represented by: The molecular structure represented by the above general formula (2) is the following general formula (2-1):

[In general formula (2-1), 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 a group that connects monomer units, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 20 carbon atoms, an aryl group having 6 to 24 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, -COOR ^1A (here, R ^1A is a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or a cycloalkyl group having 6 to 18 carbon atoms) ) or a halogen atom, m2, t2 and r2 each independently represent an integer of 0 to 10, and n21 represents an integer of 2 to 800. . However, at least one of R ²¹ , R ²² and R ²³ has the following general formula (4):

(In general formula (4), R ^4a represents a straight chain or branched alkylene group having 7 to 20 carbon atoms, R ^4b represents a straight chain or branched alkylene group having 3 to 20 carbon atoms, and R ^4c represents a hydrogen atom or a methyl group, * represents a bonding position when monomer units are connected to each other, and ** represents -(R ² -O) _m2 - in the above general formula (2-1). , -(R ² -O) _t2 - or -(R ² -O) _r2 -, or a part that bonds to the oxygen atom at the 2nd, 3rd or 6th position of the cellulose skeleton). Represents a group having a group that connects the represented monomer units. ] The liquid crystal film according to claim 7, which has a molecular structure represented by the following. A sensor comprising the liquid crystal film according to claim 7 or 8. An optical element comprising the liquid crystal film according to claim 7 or 8.

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