JP2024025559A - photoresponsive polyamide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoresponsive polyamide excellent in deformation property caused by light irradiation, and an amide compound useful as a raw material of the photoresponsive polyamide.

SOLUTION: A photoresponsive polyamide has a repeating unit represented by formula (Ia) and a repeating unit represented by formula (Ib).

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to photoresponsive polyamides. More specifically, the present invention relates to a photoresponsive polyamide and a photoresponsive polyamide that are useful for applications such as optical switching materials because they have excellent deformability upon irradiation with light (ultraviolet light), that is, photoresponsiveness. This invention relates to an amide compound useful as a raw material for.

As a polyamide having a stimulus-responsive pyrrolidone ring in its main chain, a polyamide in which biologically derived itaconic acid is used as a raw material monomer has been proposed (for example, see Patent Document 1 and Non-Patent Documents 1-2). . The polyamide has the property of becoming hydrophilic and decomposing or disintegrating when exposed to ultraviolet rays or alkaline conditions, and is therefore attracting attention as a plastic that decomposes in the global environment.

In recent years, cinnamic acid has attracted attention as a sustainable raw material because it is a naturally derived compound. Due to its structural characteristics, cinnamic acid causes cis-trans isomerization and [2+2] cycloaddition when exposed to ultraviolet light. Therefore, polymer compounds that use cinnamic acid as a raw material are sensitive to light (ultraviolet light). (For example, see Patent Document 2 and Non-Patent Documents 3-5).

Polyamide derived from itaconic acid becomes hydrophilic by irradiation with ultraviolet rays, but a technical problem is that the rate of hydrophilization is slow. In addition, polymer compounds that use cinnamic acid as a raw material respond to photoresponsiveness because it is not clear whether the response to light irradiation is based on cis-trans isomerization or [2+2] cycloaddition. Its use as a sex material has hardly progressed.

JP2022-074096A Japanese Patent Application Publication No. 2020-186382

Kaneko T. et al. Macromolecules 2013, 46(10), 3719-3725 Adv. Sustainable Syst., 2022, 6(2), 2100052 Kaneko, T. et al., Nature Mater. 2006, 5, 966-970 Angew. Chem. Int. Ed. 2013, 52, 11143-11148 Takada, K. et al., ACS Appl. Polym. Interfaces 2021, 13(12), 14569-14576

The present invention has been made in view of the prior art, and provides a photoresponsive polyamide that can use naturally derived itaconic acid and cinnamic acid compounds as raw materials and has excellent deformability when irradiated with light, and An object of the present invention is to provide an amide compound useful as a raw material for responsive polyamide.

The present invention
(1) Formula (Ia):

(In the formula, R ¹ represents an optionally substituted alkylene group, an optionally substituted cycloalkylene group, or an optionally substituted arylene group)
Repeating unit and formula (Ib) represented by:

(In the formula, ^R2 represents a hydrogen atom, a hydroxyl group, a halogen atom, or an alkoxy group)
A photoresponsive polyamide having a repeating unit represented by

(2) Formula (II):

(In the formula, R ¹ is an alkylene group that may have a substituent, a cycloalkylene group that may have a substituent, or an arylene group that may have a substituent, R ² is a hydrogen atom, (represents a hydroxyl group, halogen atom or alkoxy group)
The photoresponsive polyamide according to the above (1) having a repeating unit represented by the formula (III):

(In the formula, R ¹ is an alkylene group that may have a substituent, a cycloalkylene group that may have a substituent, or an arylene group that may have a substituent, R ² is a hydrogen atom, (represents a hydroxyl group, halogen atom or alkoxy group)
It relates to an amide compound represented by

According to the present invention, naturally-derived itaconic acid and cinnamic acid compounds can be used as raw materials, and are useful as a photoresponsive polyamide that has excellent deformability when irradiated with light (ultraviolet light) and as a raw material for the photoresponsive polyamide. amide compounds are provided.

1 is a graph showing a nuclear magnetic resonance ( ¹ H-NMR) spectrum of acetyl group-containing coumaric acid obtained in Preparation Example 2. 2 is a graph showing the nuclear magnetic resonance ( ¹ H-NMR) spectrum of the amide compound obtained in Preparation Example 5. 1 is a graph showing a nuclear magnetic resonance ( ¹ H-NMR) spectrum of photoresponsive polyamide A obtained in Example 1. 1 is a chart of gel permeation chromatography of photoresponsive polyamide A obtained in Example 1. 1 is a graph showing a nuclear magnetic resonance ( ¹ H-NMR) spectrum of photoresponsive polyamide B obtained in Example 2. 1 is a chart of gel permeation chromatography of photoresponsive polyamide B obtained in Example 2. 1 is a graph showing a nuclear magnetic resonance ( ¹ H-NMR) spectrum of photoresponsive polyamide C obtained in Example 3. 1 is a chart of gel permeation chromatography of photoresponsive polyamide C obtained in Example 3. 1 is a graph showing the results of thermogravimetric analysis of photoresponsive polyamide A obtained in Example 1. 2 is a graph showing the results of thermogravimetric analysis of photoresponsive polyamide B obtained in Example 2. 3 is a graph showing the results of thermogravimetric analysis of photoresponsive polyamide C obtained in Example 3. 2 is a chart of Fourier transform infrared spectroscopy of a film made of photoresponsive polyamide B obtained in Example 2. 2 is a chart of a Fourier transform infrared spectrum after a film made of photoresponsive polyamide B obtained in Example 2 was irradiated with ultraviolet rays. Nuclear magnetic resonance ( ¹ H-NMR) spectrum of the film made of photoresponsive polyamide A obtained in Example 1 before irradiation with ultraviolet rays and irradiation with ultraviolet rays (UV) for 2 hours, 3 hours or 4 hours It is a graph showing the nuclear magnetic resonance ( ¹ H-NMR) spectrum of the subsequent film. Nuclear magnetic resonance ( ^1H -NMR) spectrum of the film made of photoresponsive polyamide A obtained in Example 1 before irradiation with ultraviolet rays and nuclear magnetic resonance of the film after irradiation with ultraviolet rays for 48 hours or 123 hours. It is a graph showing a ( ¹ H-NMR) spectrum. (A) is a photograph substituted for a drawing of a filament made of photoresponsive polyamide B obtained in Example 2, and (B) is a photograph after irradiating the filament made of photoresponsive polyamide B obtained in Example 2 with ultraviolet rays. This is a photograph substituted for a drawing of the film.

(1) Photoresponsive polyamide As described above, the photoresponsive polyamide of the present invention has the formula (Ia):

(In the formula, R ¹ represents an optionally substituted alkylene group, an optionally substituted cycloalkylene group, or an optionally substituted arylene group)
Repeating unit and formula (Ib) represented by:

(In the formula, ^R2 represents a hydrogen atom, a hydroxyl group, a halogen atom, or an alkoxy group)
It has a repeating unit represented by

Since the photoresponsive polyamide of the present invention has a repeating unit represented by formula (Ia) and a repeating unit represented by formula (Ib), it has excellent deformability upon irradiation with light (ultraviolet light).

In the repeating unit represented by formula (Ia), R ¹ is an optionally substituted alkylene group, an optionally substituted cycloalkylene group, or an optionally substituted arylene group. It is the basis. By changing the type of R ¹ , the deformability of the photoresponsive polyamide of the present invention upon irradiation with light (ultraviolet light) can be adjusted as appropriate. The above-mentioned substituents can be used within a range that does not impede the purpose of the present invention. Examples of the substituent include alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group, and butyl group; alkoxy groups having 1 to 4 carbon atoms such as methoxy group, ethoxy group, propoxy group, and butoxy group; group, hydroxyl group, halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom, cyano group, and nitrile group, but the present invention is not limited to these examples. Among the substituents, preferred are alkyl groups having 1 to 4 carbon atoms, alkoxy groups having 1 to 4 carbon atoms, hydroxyl groups and halogen atoms.

Examples of the alkylene group include an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a 2-ethylhexylene group, a decylene group, a dodecylene group, and the like having 2 to 2 carbon atoms. 12 alkylene groups, etc.

Examples of the cycloalkylene group include cycloalkylene groups having 3 to 8 carbon atoms such as cyclopropylene group, cyclobutylene group, and cyclohexylene group.

Examples of the arylene group include arylene groups having 6 to 12 carbon atoms such as phenylene group and naphthylene group.

Among R ¹ , alkylene groups, cycloalkylene groups and arylene groups are preferred, alkylene groups are more preferred, alkylene groups having 1 to 12 carbon atoms are even more preferred, and alkylene groups having 2 to 12 carbon atoms are even more preferred. . By changing the chain length of the alkylene group, the deformability of the photoresponsive polyamide of the present invention upon irradiation with light (ultraviolet light) can be easily adjusted.

In the repeating unit represented by formula (Ib), R ² is a hydrogen atom, a hydroxyl group, a halogen atom, or an alkoxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these halogen atoms, fluorine atoms and chlorine atoms are preferred, and chlorine atoms are more preferred. Examples of the alkoxy group include alkoxy groups having 1 to 4 carbon atoms such as methoxy group, ethoxy group, propoxy group, and butoxy group. Among R ² , a hydrogen atom is preferred.

In the repeating unit represented by formula (Ib), the -O- group is located at any of the o-position, m-position and p-position with respect to the -C(=O)CH=CH- group bonded to the benzene ring. Although it may be present at the p-position, it is preferably present at the p-position.

In the photoresponsive polyamide of the present invention, the repeating units represented by formula (Ia) and the repeating units represented by formula (Ib) may be present randomly, alternately, or It may exist in a block shape.

The molar ratio of the repeating unit represented by formula (Ia) to the repeating unit represented by formula (Ib) [repeat unit represented by formula (Ia)/repeat unit represented by formula (Ib)] is the molar ratio of the repeating unit represented by formula (Ia) to the repeating unit represented by formula (Ib). From the viewpoint of imparting deformability upon irradiation to the photoresponsive polyamide, the ratio is preferably 10/90 to 90/10, more preferably 15/85 to 85/15, and even more preferably 20/80 to 80/20.

The weight average molecular weight of the photoresponsive polyamide of the present invention is not particularly limited, but from the viewpoint of imparting deformability to the photoresponsive polyamide upon irradiation with light (ultraviolet light), it is preferably 3,000 to 800,000, and preferably 5,000 to 100,000. More preferably, it is 7,000 to 50,000. Note that the weight average molecular weight of the photoresponsive polyamide is a value measured based on the method described in the following examples.

The photoresponsive polyamide of the present invention can be easily prepared, for example, based on the following method, but the present invention is not limited only to this method.

1. Preparation method A of photoresponsive polyamide
(1) Preparation of itaconic acid diamine salt Itaconic acid and formula (IV):
H ₂ NR ¹ -N ₂ H (IV)
(In the formula, R ¹ is the same as above)
Itaconic acid diamine salt can be obtained by reacting with the diamine represented by:

Since the reaction between itaconic acid and diamine is a dehydration reaction, stoichiometrically, 1 mol of itaconic acid reacts with 1 mol of dicarboxylic acid. The amount of diamine per mole of itaconic acid is usually preferably 0.9 to 1.1 mole.

Itaconic acid can be easily obtained commercially from, for example, Fuso Chemical Industry Co., Ltd., Iwata Chemical Industry Co., Ltd., Cargill Company, etc. Itaconic acid may be produced using a bacterium such as Aspergillus terreus, or may be synthesized using petroleum as a raw material. Among these, itaconic acid produced using bacteria such as Aspergillus terreus is of natural origin, so it is more environmentally friendly than itaconic acid synthesized using petroleum as a raw material. This is preferable because it has the following advantages.

In formula (IV), R ¹ is, as described above, preferably an alkylene group, a cycloalkylene group or an arylene group, more preferably an alkylene group, and an alkylene group having 1 to 12 carbon atoms. More preferably, it is an alkylene group having 2 to 12 carbon atoms, even more preferably. Examples of the diamine represented by formula (IV) include ethylenediamine, butanediamine, hexanediamine, heptanediamine, octanediamine, nonanediamine, decanediamine, and dodecanediamine. These diamines may be used alone or in combination of two or more. Among these diamines, hexanediamine, octanediamine, nonanediamine and decanediamine are preferred, and hexanediamine is more preferred, from the viewpoint of imparting deformability to the photoresponsive polyamide upon irradiation with light (ultraviolet light).

The reaction between itaconic acid and diamine can be carried out in an organic solvent from the viewpoint of increasing reaction efficiency. Examples of organic solvents include aliphatic alcohols having 1 to 4 carbon atoms such as methanol, ethanol, propanol, and butanol, ketone compounds such as acetone and methyl ethyl ketone, ethyl acetate, tetrahydrofuran, dioxane, chloroform, dichloromethane, and chlorobenzene. However, the present invention is not limited to such examples. These organic solvents may be used alone or in combination of two or more. The amount of the organic solvent is not particularly limited as long as it can efficiently react itaconic acid and diamine, but is usually about 3 to 20 times the total amount (mass) of itaconic acid and diamine. The amount is preferably about 5 to 15 times the amount, more preferably about 5 to 15 times the amount.

The atmosphere when itaconic acid and diamine are reacted is not particularly limited, and may be, for example, an inert gas such as nitrogen gas or argon gas, or air. The reaction temperature between itaconic acid and diamine is not particularly limited, and from the viewpoint of increasing reaction efficiency, it is preferably 5 to 60°C, and from the viewpoint of operability, it is more preferably room temperature. The reaction time between itaconic acid and diamine cannot be determined unconditionally since it varies depending on the reaction temperature, but it is usually about 1 to 8 hours.

By reacting itaconic acid and diamine as described above, a reaction mixture containing itaconic acid diamine salt can be obtained.

The produced itaconic acid diamine salt may be used as it is, or may be used after being washed, if necessary, or after being dried.

(2) Preparation of an acetyl group-containing cinnamic acid compound An acetyl group-containing cinnamic acid compound can be prepared by reacting a cinnamic acid compound and an acetylating agent.

As the cinnamic acid compound, for example, formula (V):

(In the formula, R ² is the same as above. R ³ represents a hydrogen atom or an alkali metal atom)
Examples include cinnamic acid compounds represented by: Specific examples of cinnamic acid compounds include cinnamic acid, alkali metal salts of cinnamic acid such as sodium cinnamate, and potassium cinnamate; alkali metal salts of cinnamic acid such as coumaric acid, which is a hydroxycinnamic acid, sodium coumarate, and potassium coumarate; However, the present invention is not limited to such examples. Coumaric acid is divided into o-coumaric acid, m-coumaric acid, and p-coumaric acid depending on the position of the hydroxyl group present in the phenyl group. These coumaric acids may be used alone or in combination of two or more types. Cinnamic acid and coumaric acid are both naturally occurring, and naturally occurring cinnamic acid and coumaric acid have a lower environmental impact than cinnamic acid and coumaric acid, which are synthesized using petroleum as raw materials. It is preferable because it has the advantage of being gentle.

In the cinnamic acid compound represented by formula (V), the -OH group and R ² are at the o-position, m-position and p-position with respect to the OR ³ -C(=O)CH=CH- group bonded to the benzene ring. It may be in any position. The light (ultraviolet light) responsiveness of the photoresponsive polyamide can be changed by changing the position of the --OH group bonded to the benzene ring, R ² and R ³ .

Examples of the acetylating agent include acetic anhydride, benzoic anhydride, acetyl chloride, and acetyl bromide, but the present invention is not limited to these examples. Among these acetylating agents, acetic anhydride and benzoic anhydride are preferred, and acetic anhydride is more preferred.

Since the cinnamic acid compound and the acetylating agent react in equimolar amounts stoichiometrically, the amount of the acetylating agent per mol of the cinnamic acid compound is usually preferably 0.9 to 1.1 mol. .

The cinnamic acid compound and the acetylating agent can be reacted in the presence of an appropriate amount of base. Bases include organic bases and inorganic bases. Examples of the organic base include pyridine, triethylamine, diisopropylethylamine, and lutidine, but the present invention is not limited to these examples. Examples of the inorganic base include sodium carbonate, potassium carbonate, cesium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, calcium carbonate, and barium carbonate, but the present invention is not limited to these examples. These bases may be used alone or in combination of two or more.

The cinnamic acid compound and the acetylating agent can be reacted in an organic solvent from the viewpoint of increasing reaction efficiency. Examples of the organic solvent include hexane, toluene, xylene, etc., but the present invention is not limited to these examples. The amount of the organic solvent is not particularly limited as long as it can efficiently react the cinnamic acid compound and the acetylating agent, but it is usually equal to the total amount (mass) of the cinnamic acid compound and the acetylating agent. The amount is preferably about 3 to 20 times, more preferably about 5 to 15 times.

The atmosphere in which the cinnamic acid compound and the acetylating agent are reacted is not particularly limited, and may be, for example, an inert gas such as nitrogen gas or argon gas, or air. The reaction temperature between the cinnamic acid compound and the acetylating agent is not particularly limited, and from the viewpoint of increasing reaction efficiency, it is preferably 30° C. to reflux temperature. The reaction time between the cinnamic acid compound and the acetylating agent cannot be determined unconditionally since it varies depending on the reaction temperature, but it is usually about 2.5 to 6 hours.

By reacting a cinnamic acid compound and an acetylating agent as described above, a reaction mixture containing an acetyl group-containing cinnamic acid compound can be obtained.

The acetyl group-containing cinnamic acid compound can be purified by distilling off the solvent from the reaction mixture and recrystallizing it using, for example, a mixed solvent of ethyl acetate and hexane.

(3) Preparation of photoresponsive polyamide A photoresponsive polyamide can be prepared, for example, by polymerizing an itaconic acid diamine salt and an acetyl group-containing cinnamic acid compound by a melt polycondensation method. More specifically, a photoresponsive polyamide can be prepared based on the following method.

First, itaconic acid diamine salt and an acetyl group-containing cinnamic acid compound are mixed. When mixing itaconic acid diamine salt and acetyl group-containing cinnamic acid compound, the molar ratio of itaconic acid diamine salt and acetyl group-containing cinnamic acid compound [itaconic acid diamine salt/acetyl group-containing cinnamic acid compound] is ) is preferably 10/90 to 90/10, more preferably 15/85 to 85/15, still more preferably 20/80 to 80/20, from the viewpoint of imparting deformability to the photoresponsive polyamide by irradiation. .

The temperature at which the itaconic acid diamine salt and the acetyl group-containing cinnamic acid compound are mixed is not particularly limited, but from the viewpoint of improving operability, it is preferably room temperature. In addition, the atmosphere when mixing itaconic acid diamine salt and the acetyl group-containing cinnamic acid compound is an inert gas such as nitrogen gas or argon gas from the viewpoint of avoiding the influence of oxygen contained in the air. It is preferable.

Next, the mixture obtained by mixing the itaconic acid diamine salt and the acetyl group-containing cinnamic acid compound is heated and melted to cause condensation polymerization of the itaconic acid diamine salt and the acetyl group-containing cinnamic acid compound. Can be done.

The heating temperature of the mixture is preferably a temperature equal to or higher than the melting point of the acetyl group-containing cinnamic acid compound, more preferably 180° C. or higher, from the viewpoint of efficiently condensing the itaconic acid diamine salt and the acetyl group-containing cinnamic acid compound, and more preferably 180° C. or higher. The temperature is preferably 200°C or higher, and from the viewpoint of suppressing decomposition of the acetyl group-containing cinnamic acid compound, the temperature is preferably 300°C or lower, more preferably 250°C or lower.

Similarly to the above, the atmosphere during condensation polymerization of itaconic acid diamine salt and the acetyl group-containing cinnamic acid compound should be a non-containing atmosphere such as nitrogen gas or argon gas, from the viewpoint of avoiding the influence of oxygen contained in the air. Preferably, it is an active gas. The heating time for the mixture cannot be determined unconditionally since it varies depending on the heating temperature, but is usually about 15 to 30 hours.

Note that water is produced as a by-product through the condensation polymerization of the itaconic acid diamine salt and the acetyl group-containing cinnamic acid compound. From the viewpoint of increasing the efficiency of condensation polymerization between itaconic acid diamine salt and an acetyl group-containing cinnamic acid compound, water produced as a by-product during the condensation polymerization of itaconic acid diamine salt and an acetyl group-containing cinnamic acid compound is appropriately used. It is preferable to remove it by reducing the pressure in the reaction system.

By condensing and polymerizing the itaconic acid diamine salt and the acetyl group-containing cinnamic acid compound as described above, a reaction mixture containing a polyamide oligomer can be obtained.

For example, the polyamide oligomer can be regenerated by dissolving the reaction mixture in an alcohol such as methanol and dropping the resulting alcohol solution into a mixed solvent such as a mixed solvent of acetic acid and ethylhexane. It can be recovered by precipitating and removing the solvent from the precipitate using an evaporator.

Next, the polyamide oligomer obtained above is subjected to melt polycondensation in the presence of an appropriate amount of catalyst. Examples of the catalyst include antimony oxide, barium oxide, zinc acetate, manganese acetate, cobalt acetate, zinc succinate, zinc borate, cadmium formate, dibutyltin dioxide, etc., but the present invention is limited only to such examples. It is not something that will be done.

The heating temperature of the polyamide oligomer is preferably a temperature higher than the melting point of the polyamide oligomer, more preferably 180°C or higher, still more preferably 200°C or higher, from the viewpoint of efficiently obtaining a photoresponsive polyamide. From the viewpoint of suppressing decomposition, the temperature is preferably 300°C or lower, more preferably 250°C or lower.

The atmosphere during condensation polymerization of the polyamide oligomer is preferably an inert gas such as nitrogen gas or argon gas, from the viewpoint of avoiding the influence of oxygen contained in the air, as described above. The heating time for the mixture cannot be determined unconditionally since it varies depending on the heating temperature, but is usually about 25 to 50 hours.

Note that water is produced as a by-product during the polycondensation of polyamide oligomers. From the viewpoint of increasing the efficiency of polycondensation polymerization of polyamide oligomers, it is preferable to remove by-product water by appropriately reducing the pressure in the reaction system during polycondensation polymerization of polyamide oligomers.

By condensation polymerizing the polyamide oligomer as described above, a reaction mixture containing a photoresponsive polyamide having a repeating unit represented by formula (Ia) and a repeating unit represented by formula (Ib) can be obtained. .

The reaction mixture containing the photoresponsive polyamide obtained above can be used as it is, but if necessary, it may be used after being purified.

The photoresponsive polyamide of the present invention can be produced by incorporating a third monomer into the reaction system within a range that does not impede the object of the present invention. The repeating unit other than the repeating unit shown in FIG.

2. Preparation method B of photoresponsive polyamide
(1) Preparation of N-amino group-containing carboxypyrrolidine compound The N-amino group-containing carboxypyrrolidine compound can be prepared, for example, by dissolving the itaconic acid diamine salt in water at room temperature, refluxing the resulting aqueous solution, and adding it to the aqueous solution. It can be easily prepared by distilling off the water contained therein.

(2) Preparation of a halide of an acetyl group-containing cinnamic acid compound A halide of an acetyl group-containing cinnamic acid compound can be easily obtained, for example, by reacting the acetyl group-containing cinnamic acid compound with a halogenating agent in an organic solvent. be able to.

Examples of the halogenating agent include hydrogen chloride, thionyl chloride, sulfuryl chloride, phosphorus trichloride, phosphorus pentachloride, trichloride phosphate, oxalyl chloride, carbon tetrachloride-triphenylphosphine, hydrogen bromide, phosphorus tribromide, Examples include phosphorus bromide, carbon tetrabromide-triphenylphosphine, hydrogen iodide, and iodine-triphenylphosphine, but the present invention is not limited to these examples.

The amount of the halogenating agent per mole of the acetyl group-containing cinnamic acid compound is not particularly limited, but is usually preferably about 1 to 3 moles.

Examples of organic solvents include aliphatic alcohols having 1 to 3 carbon atoms such as methanol, ethanol, and propanol, ketone compounds such as acetone and methyl ethyl ketone, ethyl acetate, tetrahydrofuran, dioxane, chloroform, dichloromethane, chlorobenzene, phenol, and cresol. However, the present invention is not limited to these examples. These organic solvents may be used alone or in combination of two or more.

The amount of the organic solvent is not particularly limited as long as it can efficiently obtain the halide of the acetyl group-containing cinnamic acid compound, but it is usually about 3 to 20 times the mass of the acetyl group-containing cinnamic acid compound. The amount is preferably about 5 to 15 times the amount, and more preferably about 5 to 15 times the amount.

The atmosphere when halogenating the acetyl group-containing cinnamic acid compound should be an inert gas such as nitrogen gas or argon gas, from the viewpoint of avoiding the influence of oxygen contained in the air. preferable. Further, the atmosphere in which the acetyl group-containing cinnamic acid compound is converted into a halide may be at normal pressure, or may be under reduced pressure or increased pressure if necessary.

The temperature at which the acetyl group-containing cinnamic acid compound is halogenated is not particularly limited, but from the viewpoint of efficiently preparing the halide of the acetyl group-containing cinnamic acid compound, it is preferably 60° C. to reflux temperature. The time required for halogenating an acetyl group-containing cinnamic acid compound cannot be determined unconditionally because it varies depending on the temperature at which the acetyl group-containing cinnamic acid compound is halogenated, but it is usually about 1.5 to 5 hours. be.

By halogenating the acetyl group-containing cinnamic acid compound as described above, a halide of the acetyl group-containing cinnamic acid compound can be obtained.

(3) Preparation of amide compound The amide compound can be easily prepared by reacting the N-amino group-containing carboxypyrrolidine compound with the halide of the acetyl group-containing cinnamic acid compound.

The reaction between the N-amino group-containing carboxypyrrolidine compound and the acetyl group-containing cinnamic acid compound halide can be carried out at room temperature in an organic solvent. Examples of organic solvents include N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, trifluoroacetic acid, dimethyl sulfoxide, but the present invention is limited only to these examples. isn't it.

The amount of the organic solvent is not particularly limited as long as it can efficiently obtain the amide compound, but it is usually the total amount of the N-amino group-containing carboxypyrrolidine compound and the acetyl group-containing cinnamic acid compound halide. (capacity) is preferably about 1 to 10 times, and more preferably about 3 to 5 times.

The reaction between the N-amino group-containing carboxypyrrolidine compound and the acetyl group-containing cinnamic acid compound halide is preferably carried out in the presence of an appropriate amount of base. Bases include organic bases and inorganic bases. Examples of the organic base include pyridine, triethylamine, diisopropylethylamine, and lutidine, but the present invention is not limited to these examples. Examples of the inorganic base include sodium carbonate, potassium carbonate, cesium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, calcium carbonate, and barium carbonate, but the present invention is not limited to these examples. These bases may be used alone or in combination of two or more.

The atmosphere when reacting the N-amino group-containing carboxypyrrolidine compound and the acetyl group-containing cinnamic acid compound halide is, for example, nitrogen gas, from the viewpoint of avoiding the influence of oxygen contained in the air. , an inert gas such as argon gas is preferable. Further, the atmosphere in which the N-amino group-containing carboxypyrrolidine compound and the acetyl group-containing cinnamic acid compound halide are reacted may be at normal pressure, or may be under reduced pressure or increased pressure as necessary.

By reacting the N-amino group-containing carboxypyrrolidine compound and the acetyl group-containing cinnamic acid compound halide in the manner described above, a reaction mixture containing an amide compound can be obtained. The amide compound obtained above can be recovered by, for example, adding an extraction solvent such as ethyl acetate and water to the reaction mixture and extracting the organic layer.

The amide compound obtained above has the formula (III):

(In the formula, R ¹ and R ² are the same as above)
It is expressed as The amide compound represented by formula (III) can be suitably used as a raw material for the photoresponsive polyamide of the present invention.

(4) Preparation of photoresponsive polyamide A photoresponsive polyamide represented by formula (II) can be obtained by polymerizing an amide compound represented by formula (III).

Examples of methods for polymerizing the amide compound represented by formula (III) include bulk polymerization, suspension polymerization, and emulsion polymerization, but the present invention is not limited to these examples. . Among these polymerization methods, the bulk polymerization method is preferred from the viewpoint of efficiently preparing a photoresponsive polyamide with a small amount of impurities. When preparing a photoresponsive polyamide by a bulk polymerization method, the photoresponsive polyamide can be obtained by heating the amide compound represented by formula (III) to a polymerization temperature of about 150 to 250 ° C. and polymerizing it.

The atmosphere during polymerization of the amide compound represented by formula (III) is preferably an inert gas such as nitrogen gas or argon gas from the viewpoint of avoiding the influence of oxygen contained in the air. The polymerization time of the amide compound cannot be determined unconditionally since it varies depending on the polymerization temperature, but it is usually about 5 to 20 hours.

When polymerizing the amide compound, it is preferable to use an appropriate amount of a catalyst from the viewpoint of efficiently preparing a photoresponsive polyamide. Examples of the catalyst include sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, lithium dihydrogen phosphate, and dihydrogen phosphate. Examples include lithium and trilithium phosphate, but the present invention is not limited to these examples. Among the catalysts, sodium dihydrogen phosphate is preferred.

Note that water is produced as a by-product during the polymerization of the amide compound. From the viewpoint of increasing the efficiency of the polymerization reaction of the amide compound, it is preferable to remove by-produced water by appropriately reducing the pressure in the reaction system during polymerization of the amide compound.

By polymerizing the amide compound as described above, a photoresponsive polyamide can be obtained. The photoresponsive polyamide obtained above may be purified, if necessary, by dissolving it in a solvent such as N,N-dimethylformamide and then precipitating it with a ketone compound such as acetone. Further, the photoresponsive polyamide obtained above may be dried, for example, by drying under reduced pressure.

The photoresponsive polyamide obtained as described above has the formula (II):

(In the formula, R ¹ and R ² are the same as above)
It has a repeating unit represented by The photoresponsive polyamide having the repeating unit represented by formula (II) has a structure in which the repeating unit represented by formula (Ia) and the repeating unit represented by formula (Ib) are bonded, and therefore has the formula ( It has a block copolymer structure of a repeating unit represented by Ia) and a repeating unit represented by formula (Ib).

In addition, the photoresponsive polyamide having a repeating unit represented by formula (II) of the present invention may not contain repeating units other than the repeating unit represented by formula (II) within a range that does not impede the object of the present invention. You can.

The photoresponsive polyamide obtained above may be purified, if necessary, by dissolving it in a solvent such as N,N-dimethylformamide and then precipitating it with a ketone compound such as acetone. Further, the photoresponsive polyamide obtained above may be dried, for example, by drying under reduced pressure.

If necessary, the photoresponsive polyamide of the present invention may contain an appropriate amount of additives depending on its use. Examples of additives include coloring agents such as pigments and dyes, ultraviolet absorbers, ultraviolet stabilizers, antioxidants, rust preventives, antibacterial agents, plasticizers, algaecides, fungicides, flame retardants, and foaming agents. However, the present invention is not limited to only such examples. These additives may be used alone or in combination of two or more. Since the amount of the additive varies depending on the type of the additive and cannot be determined unconditionally, it is preferable to appropriately determine the amount depending on the type of the additive.

3. Application of photoresponsive polyamide The photoresponsive polyamide of the present invention exhibits a behavior of being deformed by irradiation with ultraviolet rays. The wavelength of ultraviolet rays at which the photoresponsive polyamide exhibits the behavior of deforming upon irradiation with ultraviolet rays is not particularly limited, but is preferably 200 to 400 nm. The photoresponsive polyamide of the present invention exhibits excellent deformability to ultraviolet light having a wavelength of 300 to 400 nm within the wavelength range of ultraviolet light. Furthermore, the photoresponsive polyamide of the present invention has a property of being deformed by irradiation with ultraviolet rays and then returning to its original shape by irradiating it with ultraviolet rays having a wavelength of 200 to 250 nm.

Therefore, by using the wavelength at which the photoresponsive polyamide exhibits deformation behavior and the wavelength at which the deformed photoresponsive polyamide restores to its original shape, the shape can be shaped by repeatedly irradiating ultraviolet rays with different wavelengths. Since the photoresponsive polyamide of the present invention can be repeatedly deformed and restored, the photoresponsive polyamide of the present invention can be moved by, for example, a photomobility motor that is powered by light and does not require electricity, a light-driven actuator, or a light signal. It is expected to be used in a variety of applications, including artificial muscles, soft robots that can be moved by optical signals, and switches that respond to light.

Moreover, since the photoresponsive polyamide of the present invention is dissolved in an organic solvent, a spinning dope can be prepared by dissolving the photoresponsive polyamide in an organic solvent. The organic solvent is not particularly limited as long as it can dissolve the photoresponsive polyamide. Examples of organic solvents include N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, formic acid, trifluoroacetic acid, dimethyl acetate, and dimethyl sulfoxide. It is preferable to use an organic solvent suitable for dissolving the responsive polyamide.

The amount of organic solvent for the photoresponsive polyamide of the present invention cannot be determined unconditionally because it varies depending on the type of organic solvent. Generally, it is preferable to dissolve the photoresponsive polyamide in an organic solvent so that the spinning dope has a desired viscosity at a predetermined temperature.

A polyamide fiber can be produced by extruding the spinning dope obtained above through the pores of a spinneret and volatilizing the organic solvent.

In addition, since the photoresponsive polyamide of the present invention has thermoplasticity, the photoresponsive polyamide is melted by heating and injected from the pores of a spinneret using a melt spinning device to melt-spun the polyamide. Fibers can be manufactured.

Spinnerets are generally made of alloys such as gold and platinum alloys, platinum and iridium alloys, and platinum and palladium alloys. The pore diameter of the spinneret is appropriately determined depending on the fineness of the intended polyamide fiber, but is usually about 0.05 to 0.1 mm. The number of holes provided in the spinneret is not particularly limited, but is usually about 1 to 20,000.

The polyamide fibers may be single fibers (filaments), or may be fibers made by converging a plurality of single fibers extruded from a plurality of holes into a single bundle.

The polyamide fiber obtained as described above may be subjected to treatments such as washing with water, drying, and crimping, if necessary.

The fineness of the polyamide fiber obtained above cannot be determined unconditionally because it varies depending on the use of the polyamide fiber, so it is preferable to appropriately determine it depending on the use of the polyamide fiber. An example of the fineness of polyamide fibers is, for example, 1 to 30 dtex, but the present invention is not limited by this fineness. The fineness of the polyamide fiber can be easily adjusted by adjusting the hole diameter of the spinneret or by adjusting the stretching ratio when drawing the polyamide fiber.

The polyamide fiber obtained above may be stretched as necessary to increase mechanical strength. The polyamide fibers are usually drawn by uniaxial drawing, but may be multiaxial drawing such as biaxial drawing.

The polyamide fibers may be used in the form of long fibers, or may be cut to a desired fiber length and used as short fibers. Since the fiber length of the polyamide fiber varies depending on the use of the polyamide fiber, it is preferable to appropriately determine the fiber length depending on the use of the polyamide fiber. Polyamide fibers can be used, for example, in woven fabrics, nonwoven fabrics, knitted fabrics, and the like.

The knitted fabric can be manufactured using the polyamide fiber using a stockinette knitting machine or the like. When producing knitted fabrics, the polyamide fibers may be used as they are; for example, the polyamide fibers may be blended with synthetic fibers such as polyester fibers and acrylic fibers, fibers such as cotton yarn, woolen yarn, and raw silk. A thread may also be used. Examples of knitted fabrics include flat knitting, rubber knitting, purl knitting, etc., but the present invention is not limited to these examples.

The woven fabric can be manufactured using a loom or the like using the polyamide fibers for the warp, the weft, or both the warp and the weft. The woven fabric may be a blended fabric in which a blended yarn containing polyamide fibers is used in part or all of the warp and weft, and the warp and weft have different compositions, and the warp and/or weft contain polyamide fibers. It may be a mixed woven fabric using fibers, or it may be a highly distributed fabric containing the polyamide fiber of the present invention and using warps and wefts with different fiber diameters. Examples of the texture of the woven fabric include a plain weave texture, a diagonal weave texture, a twill weave texture, a satin weave texture, and a modified texture, but the present invention is not limited to these examples.

The nonwoven fabric can be manufactured by a dry method or a wet method using fibers containing the polyamide fibers. The fibers used in the nonwoven fabric may be only the polyamide fibers, or may be a blend of the polyamide fibers and synthetic fibers such as polyester fibers and acrylic fibers, and fibers such as cotton yarn, wool yarn, and raw silk. . Examples of the dry method include mechanical bonding methods such as a chemical pounding method, a thermal pounding method, a needle punching method, and an air laying method, but the present invention is not limited to these examples. Examples of the wet method include a hydroentangling method, but the present invention is not limited to such examples.

Furthermore, since the photoresponsive polyamide of the present invention is soluble in an organic solvent, it can be used as an organic solvent solution, so by casting an organic solvent solution of the photoresponsive polyamide on the surface of a base material, In addition to being usable as a film, it can also be suitably used as a molding material such as an injection molding material.

Next, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples. In addition, the physical properties of the compounds obtained in the following examples were investigated based on the following methods.

[Structure of compound]
The structure of the compound was determined by nuclear magnetic resonance ( ¹ H-NMR) and Fourier transform infrared spectroscopy (FT-IR).

(1) Nuclear magnetic resonance ( ¹ H-NMR)
For nuclear magnetic resonance ( ^1H -NMR), 5 mg of the sample was dissolved in 0.5 mL of dimethyl sulfoxide-d ₆ using a nuclear magnetic resonance spectrometer [manufactured by BRUKER, trade name: AVANCE III HD NMR Spectrometer, 400 MHz]. The resulting solution was placed in a glass sample tube and measured at a temperature of 25° C. for a total of 16 times.

(2) Fourier transform infrared spectroscopy (FT-IR)
Fourier transform infrared spectroscopy (FT-IR) uses a Fourier transform infrared spectrometer (manufactured by Perkin Elmer, product name: Spectrum 100, ATR method), with a measurement wave number range of 400 to 4000 cm ^{- 1} , and the measurement was performed with four integration times.

[Average molecular weight of polymer]
The average molecular weight (weight average molecular weight and number average molecular weight) of the polymer was measured by gel permeation chromatography (GPC). More specifically, the equipment includes a liquid pump unit [manufactured by JASCO Corporation, product number: PU-2080], a column oven [manufactured by GL Sciences, Inc., product number: CO631A, set temperature: 40°C], and an ultraviolet-visible device. Detector [manufactured by JASCO Corporation, product number: UV-2075], differential refractometer [manufactured by JASCO Corporation, product number: RI-2031], and column [manufactured by Showa Denko Corporation, product name: Shodex SB- 806M HQ, 2 units]. In addition, a polymethyl methacrylate standard [molecular weight (Mp): 3070, 7360, 18500, 68800, 211000, 569000 or 1050000] was used as a standard sample, and a lithium bromide solution with a lithium bromide concentration of 0.01 mol/L was used as a mobile phase. A solution of lithium in N,N-dimethylformamide was used, and the flow rate of the solution was set to 1.0 mL/min.

[Thermal properties of polymers]

Thermal properties of the polymers were determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).

(1) Thermogravimetric analysis (TGA)
Thermogravimetric analysis was performed using a differential thermogravimetric simultaneous measurement device [manufactured by Hitachi High-Tech Science Co., Ltd., product number: STA 7200], using a sample amount of 4 to 8 mg, and using a platinum pan as a reference blank (no sample). As a result, the sample was heated in a nitrogen gas atmosphere (nitrogen gas flow rate: 250 mL/min) at a temperature increase rate of 10 °C/min in the temperature range from 25 °C to 800 °C, and the mass of the sample decreased by 5%. Alternatively, the temperature at which the weight decreased by 10% was defined as the 5% weight loss temperature (T _d5 ) or the 10% weight loss temperature (T _d10 ), respectively.

(2) Differential scanning calorimetry (DSC)
Differential scanning calorimetry was carried out using a differential scanning calorimeter (manufactured by Hitachi High-Tech Science Co., Ltd., model number: : 40mL/min) at a heating rate of 10℃/min in the temperature range from -20℃ to 280℃, held at the maximum temperature for 5 minutes, and then -10℃ from the maximum temperature to -20℃. The temperature was lowered to -20°C at a cooling rate of /min and held at -20°C for 5 minutes. A series of temperature raising and lowering operations was repeated three times, and the data was obtained when the operation was performed two or three times. used.

Preparation Example 1 (Preparation of itaconic acid hexamethylenediamine salt)

Each solution obtained after dissolving 6.53 g (50.19 mmol) of itaconic acid and 5.81 g (50.08 mmol) of hexamethylene diamine in 100 mL of ethanol at room temperature (approximately 25° C.) in the atmosphere They were mixed together under stirring for 1 hour. The white precipitate contained in the obtained mixed solution was collected by suction filtration and dried under reduced pressure at a temperature of 60°C to obtain 12.21 g of itaconic acid hexamethylene diamine salt as a white solid (yield: 99%).

Preparation Example 2 (Preparation of coumaric acid containing acetyl group)

m-coumaric acid, which is a hydroxycinnamic acid, was used as the cinnamic acid compound. After adding 9.10 g (55.43 mmol) of m-coumaric acid to 150 mL of toluene in the atmosphere, 6.29 mL of acetic anhydride and 1.48 mL of pyridine were added to the toluene with stirring, and the resulting mixed solution The mixture was refluxed for 3 hours.

Next, the solvent contained in the mixed solution was distilled off using an evaporator, and 11.11 g of acetyl group-containing coumaric acid was converted into a white solid by recrystallizing it at room temperature using a mixed solvent of ethyl acetate and hexane. (yield: 97%).

Nuclear magnetic resonance ( ¹ H-NMR) of the acetyl group-containing coumaric acid obtained above is as follows. The nuclear magnetic resonance ( ¹ H-NMR) spectrum of acetyl group-containing coumaric acid is shown in FIG.

[Nuclear magnetic resonance ( ¹ H-NMR) of coumaric acid containing acetyl group]
¹ H-NMR (400MHz, DMSO-d ₆ ) δ2.27(s, 3H, CH), 6.55(d, 1H, CH), 7.17(dd, 1H, ArH), 7.45(t, 1H, ArH), 7.50(st, 1H, ArH), 7.55(d, 1H, ArH), 7.59(d, 1H, OH), 12.5(brs, 1H, OH)

Preparation Example 3 (Preparation of N-aminohexamethylene-2-carbonyl-4-carboxypyrrolidine)

4.07 g (16.52 mmol) of the hexamethylene itaconate diamine salt obtained in Preparation Example 1 was dissolved in 10 mL of pure water in the air, and the resulting aqueous solution was refluxed for 48 hours. By distilling off the water contained therein using an evaporator, 4.05 g of N-aminohexamethylene-2-carbonyl-4-carboxypyrrolidine was obtained in the form of an oil (yield: 99%).

Preparation Example 4 (Preparation of acetyl group-containing coumaric acid chloride)

In a nitrogen gas atmosphere, 3.40 g (16.50 mmol) of acetyl group-containing coumaric acid obtained in Preparation Example 2 was added to 50 mL of a dichloromethane solution of thionyl chloride in which the concentration of thionyl chloride was 1.0 mol/L. A reaction mixture was obtained by refluxing the obtained mixed solution for 3 hours. By distilling off the solvent contained in the reaction mixture obtained above using an evaporator, 3.52 g of acetyl group-containing coumaric acid chloride was obtained in the form of an oil (yield: 95%).

Preparation Example 5 (Preparation of amide compound)

3.42 g (15.0 mmol) of N-aminohexamethylene-2-carbonyl-4-carboxypyrrolidine obtained in Preparation Example 3 and acetyl group-containing coumaric acid chloride 3 obtained in Preparation Example 4 in a nitrogen gas atmosphere. .52 g (15.67 mmol) were each dissolved in 25 mL of N,N-dimethylacetamide, the resulting solutions were mixed, and 1.33 mL of pyridine was added to the resulting mixed solution and mixed under stirring. Ethyl acetate and pure water were added to the obtained reaction product and the organic layer was extracted to obtain 5.43 g of an amide compound in the form of an oil (yield: 87%).

The nuclear magnetic resonance ( ¹ H-NMR) of the amide compound obtained above is as follows. The nuclear magnetic resonance ( ¹ H-NMR) spectrum of the amide compound is shown in FIG.

[Nuclear magnetic resonance ( ¹ H-NMR) of amide compounds]
¹ H-NMR (400MHz, DMSO-d ₆ ) δ1.35-1.50 (br, 4H, -CH ₂ CH ₂ -), 3.10(s, 2H, COCH ₂ ), 3.20(m, 1H, HOOCCH-), 6.60(d, 1H, ArH), 6.08(d, 1H, ArH), 7.00-8.00(m, 4H, ArH), 8.05(t, 1H, NH), 12.5(brs, 1H, COOH)

Example 1 (Preparation of photoresponsive polyamide A)

5.17 g (20.99 mmol) of itaconic acid hexamethylene diamine salt obtained in Preparation Example 1, 1.44 g (6.98 mmol) of acetyl group-containing coumaric acid obtained in Preparation Example 2, and 65. 5 mg were mixed at room temperature in a nitrogen gas atmosphere, and the resulting mixture was subjected to melt polycondensation at 200° C. for 25.5 hours. At this time, pressure reduction was started 19 hours after the start of the polymerization reaction.

After the polymerization reaction is completed, the product obtained above is dissolved in methanol, and the obtained methanol solution is dropped into a mixed solvent of acetic acid and ethylhexane [acetic acid/ethylhexane volume ratio: 9/1]. By doing so, a product containing a polyamide oligomer was reprecipitated. The polyamide oligomer was recovered by distilling off the solvent from the generated precipitate using an evaporator.

Next, 1.69 g of the polyamide oligomer obtained above and 17.3 mg of antimony (III) oxide were mixed in a nitrogen gas atmosphere, and the resulting mixture was subjected to melt polycondensation at 200° C. for 48 hours. At this time, pressure reduction was started 13 hours after the start of the polymerization reaction. By carrying out the polymerization reaction as described above, 1.28 g of photoresponsive polyamide A was obtained (yield: 21%). The number average molecular weight (Mn) of photoresponsive polyamide A is 4.0×10 ³ , the weight average molecular weight (Mw) is 7.1×10 ³ , and the molecular weight distribution (Mw/Mn) is 1.8. there were.

The nuclear magnetic resonance ( ¹ H-NMR) spectrum of photoresponsive polyamide A is shown in FIG. Further, a chart of gel permeation chromatography of photoresponsive polyamide A is shown in FIG.

Example 2 (Preparation of photoresponsive polyamide B)

4.00 g (16.24 mmol) of itaconic acid hexamethylene diamine salt obtained in Preparation Example 1, 3.40 g (16.49 mmol) of acetyl group-containing coumaric acid obtained in Preparation Example 2, and 73. 7 mg were mixed in a nitrogen gas atmosphere, and the resulting mixture was subjected to melt polycondensation at 200° C. for 25.5 hours. At this time, pressure reduction was started 19 hours after the start of the polymerization reaction.

After the polymerization reaction is completed, the product obtained above is dissolved in methanol, and the obtained methanol solution is dropped into a mixed solvent of acetic acid and ethylhexane [acetic acid/ethylhexane volume ratio: 9/1]. The product was reprecipitated by doing this. A polyamide oligomer was obtained by distilling off the solvent from the generated precipitate using an evaporator.

Next, 770.1 mg of the polyamide oligomer obtained above and 68.6 mg of antimony (III) oxide were mixed in a nitrogen gas atmosphere, and the resulting mixture was subjected to melt polycondensation at 200° C. for 48 hours. At this time, pressure reduction was started 13 hours after the start of the polymerization reaction. By carrying out the polymerization reaction as described above, 168.8 mg of photoresponsive polyamide B was obtained (yield: 21%). The number average molecular weight (Mn) of photoresponsive polyamide B is 5.4×10 ³ , the weight average molecular weight (Mw) is 24.2×10 ³ , and the molecular weight distribution (Mw/Mn) is 4.5. there were.

The nuclear magnetic resonance ( ¹ H-NMR) spectrum of the photoresponsive polyamide B obtained above is shown in FIG. Further, a gel permeation chromatography chart of photoresponsive polyamide B is shown in FIG.

Example 3 (Preparation of photoresponsive polyamide C)

2.83 g (11.49 mmol) of itaconic acid hexamethylene diamine salt obtained in Preparation Example 1, 7.06 g (34.23 mmol) of acetyl group-containing coumaric acid obtained in Preparation Example 2, and 96 g (34.23 mmol) of disodium hydrogen phosphate. 1 mg were mixed in a nitrogen gas atmosphere, and the resulting mixture was subjected to melt polycondensation at 200° C. for 25.5 hours. At this time, pressure reduction was started 19 hours after the start of the polymerization reaction. After the polymerization reaction was completed, the product obtained above was obtained in a molten state as a polyamide oligomer.

Next, 5.0 g of the polyamide oligomer obtained above and 100.1 mg of antimony (III) oxide were mixed in a nitrogen gas atmosphere, and the resulting mixture was subjected to melt polycondensation at 200° C. for 48 hours. At this time, pressure reduction was started 13 hours after the start of the polymerization reaction. By carrying out the polymerization reaction as described above, 4.81 g of photoresponsive polyamide C was obtained (yield: 53%). The number average molecular weight (Mn) of photoresponsive polyamide C is 5.4×10 ³ , the weight average molecular weight (Mw) is 28.8×10 ³ , and the molecular weight distribution (Mw/Mn) is 5.3. there were.

The nuclear magnetic resonance ( ¹ H-NMR) spectrum of photoresponsive polyamide C is shown in FIG. Further, a chart of gel permeation chromatography of photoresponsive polyamide C is shown in FIG.

Example 4 (Preparation of photoresponsive polyamide D)
3.0 g (113.14 mmol) of the amide compound obtained in Preparation Example 5 and 30 mg of disodium hydrogen phosphate were mixed at room temperature in a nitrogen gas atmosphere, and the resulting mixture was subjected to melt polycondensation at 200°C for 10 hours. I let it happen. At this time, pressure reduction was started 8 hours after the start of the polymerization reaction.

By carrying out the polymerization reaction of the amide compound as described above, 1.63 g of photoresponsive polyamide D was obtained (yield: 54%). The number average molecular weight (Mn) of photoresponsive polyamide D is 4.5×10 ³ , the weight average molecular weight (Mw) is 20.2×10 ³ , and the molecular weight distribution (Mw/Mn) is 4.9. there were. Although the photoresponsive polyamide D obtained above was insoluble in the solvent used for ¹ H-NMR at room temperature, it was confirmed that it had photoreactivity equivalent to that of the photoresponsive polyamides A to C. Ta.

[Thermal properties of photoresponsive polyamide]
The photoresponsive polyamides A to C obtained above were subjected to thermogravimetric analysis (TGA). The results of thermogravimetric analysis of photoresponsive polyamides A to C are shown in FIGS. 9 to 11, respectively.

Furthermore, the 5% weight loss temperature (T _d5 ), 10% weight loss temperature (T _d10 ), and glass transition temperature (Tg) of the photoresponsive polyamides A to D were investigated. The results are shown in Table 1.

From the results shown in Table 1, it can be seen that the photoresponsive polyamides obtained in each example all have a heat resistance temperature of 340° C. or higher.

[Structural change of photoresponsive polyamide due to ultraviolet irradiation]
235.8 mg of photoresponsive polyamide B was dissolved in 2.35 mL of N,N-dimethylacetamide at room temperature, and the resulting solution was filtered with a syringe filter. The collected filtrate was heated at 140° C. for 13 hours to volatilize a portion of the solvent, thereby obtaining a solution of photoresponsive polyamide B with increased viscosity.

A film was produced by dropping the solution of photoresponsive polyamide B obtained above onto a glass plate with a smooth surface, heating at 100° C. for 30 hours, and then drying under reduced pressure at room temperature for 9 hours. From this, it was confirmed that the photoresponsive polyamide obtained above has excellent film forming properties. In addition, cellophane adhesive tape was attached to the film made of the photoresponsive polyamide obtained above, and an attempt was made to peel it off from the glass plate, but the film could not be easily peeled off from the glass plate, and the film could not be peeled off before it was peeled off. Since the film was destroyed, it was confirmed that the film had excellent adhesion to the glass plate.

Next, the Fourier transform infrared spectra of the film obtained above were examined. The results are shown in FIG. In addition, the film obtained above was exposed to ultraviolet light (wavelength: 350 nm, ultraviolet intensity: 26.00 mW/cm ² ) for 48 hours using a xenon light source [manufactured by Asahi Bunko Co., Ltd., product number: MAX-303]. The Fourier transform infrared spectra after irradiation were investigated. The results are shown in FIG.

From the results shown in FIGS. 12 and 13, it can be seen that the absorption derived from the cis isomer observed at 700 cm ⁻¹ increases slightly before and after irradiating the film with ultraviolet rays. From this, it was confirmed that the structure of the photoresponsive polyamide changes due to ultraviolet irradiation.

Next, using a solution of photoresponsive polyamide A prepared in the same manner as the solution of photoresponsive polyamide B, a xenon light source [manufactured by Asahi Spectroscopy Co., Ltd., product number: MAX-303] was applied to a film produced in the same manner as above. ], the nuclear magnetic resonance ( ¹ H-NMR) spectrum of the film before irradiation with ultraviolet rays (UV) (wavelength: 350 nm, ultraviolet intensity: 26.00 mW/cm ² ), the corresponding ultraviolet rays (UV) The nuclear magnetic resonance ( ¹ H-NMR) spectrum of the film after being irradiated with the ultraviolet rays (UV) for 2 hours, the nuclear magnetic resonance ( ¹ H-NMR) spectrum of the film after being irradiated with the ultraviolet rays (UV) for 3 hours, and the ultraviolet rays (UV) ) was irradiated for 4 hours, and the nuclear magnetic resonance ( ¹ H-NMR) spectrum of the film was examined. The results are shown in FIG.

From the results shown in Figure 14, when the film was irradiated with ultraviolet rays, a double peak appeared in the nuclear magnetic resonance ( ^1H -NMR) spectrum at a location smaller than 6 ppm. It can be seen that the cinnamic acid-based unit inside causes cis isomerization. This result is in good agreement with the results shown in FIGS. 12 and 13.

Next, the film made of photoresponsive polyamide A after photodeformation obtained above was irradiated with ultraviolet rays in the short wavelength region (wavelength: 250 nm, ultraviolet intensity: 5.00 mW/cm ² ). Infrared (IR) spectrum, Infrared (IR) spectrum of the film after 48 hours of irradiation with the short wavelength ultraviolet (UV), and Infrared (IR) spectrum of the film after 123 hours of irradiation with the short wavelength ultraviolet (UV). IR) spectrum was examined. The results are shown in FIG.

From the results shown in FIG. 15, it was found that by irradiating a film made of photoresponsive polyamide A after photodeformation with short wavelength ultraviolet rays, trans and cis forms of the cinnamic acid-based unit in photoresponsive polyamide A were detected. It can be seen that the absorption derived from . This suggests that the cinnamic acid-based units of the photoresponsive polyamide are isomerized by irradiation with short wavelength ultraviolet rays, and that the photoresponsive polyamide has reversible photoresponsiveness.

[Photodeformability of photoresponsive polyamide]
Weigh out 235.8 mg each of photoresponsive polyamide A, photoresponsive polyamide B, photoresponsive polyamide C, or photoresponsive polyamide D at room temperature, and add 2.35 mL of N,N-dimethylacetamide to each photoresponsive polyamide. The resulting solution was filtered with a syringe filter. The collected filtrate was heated at 140° C. for 13 hours to volatilize a portion of the solvent, thereby obtaining a solution of each photoresponsive polyamide with increased viscosity.

Using each photoresponsive polyamide solution obtained above, a filament with a diameter of about 0.5 mm and a length of 1 cm was produced, and the filament was sufficiently dried at room temperature (about 25 ° C.). Ta.

FIG. 16A shows a photograph of the filament made of the photoresponsive polyamide B obtained above when one end of the filament is held between tweezers. Next, a xenon light source [manufactured by Asahi Bunko Co., Ltd., product number: MAX-303] was applied to the filament, one end of which was pinched with tweezers, and ultraviolet light (wavelength: 350 nm, ultraviolet intensity: 26.00 mW/cm ² ) was applied to the filament. UV rays were irradiated for 3 seconds. A photograph substituted for a drawing of the filament after irradiation with ultraviolet rays is shown in FIG. 16(B). From the results shown in FIG. 16, it was confirmed that the filament bent toward the side irradiated with ultraviolet rays so as to stick to the tweezers. In addition, when filaments made of responsive polyamide A, photoresponsive polyamide C, or photoresponsive polyamide D were used in place of the filaments made of photoresponsive polyamide B, and ultraviolet rays were irradiated in the same manner as above, each filament Similar to the filament made of responsive polyamide B, it was confirmed that the filament bent toward the side irradiated with ultraviolet rays so as to stick to the tweezers. This shows that photoresponsive polyamide has the property of being dramatically deformed by short-term irradiation with ultraviolet rays.

The reason why the photoresponsive polyamide deforms when exposed to ultraviolet rays is that the pyrrolidone ring of the photoresponsive polyamide opens and isomerizes the repeating unit derived from cinnamic acid. Conceivable. In addition, the present inventors have also elucidated the mechanism of light (ultraviolet) responsiveness of photoresponsive polyamides using time-resolved infrared spectroscopy. It became possible to evaluate reactivity. This shows that by analyzing the spectrum obtained by the time-resolved infrared spectroscopy, it is possible to rigorously evaluate the deformability due to light (ultraviolet) irradiation.

Next, each filament deformed by irradiating it with ultraviolet rays is exposed to ultraviolet light through a filter that blocks ultraviolet rays with a wavelength of 254 nm or more, using a xenon light source [manufactured by Asahi Bunko Co., Ltd., product number: MAX-303]. (Wavelength: 250 nm, UV intensity: 1.50 mW/cm ² ) was irradiated for 5 seconds, and the filament was restored to its shape before UV irradiation. From this, it can be seen that each photoresponsive polyamide has the property of restoring to its original shape before deformation by irradiation with ultraviolet rays of different wavelengths.

Next, each filament obtained above was exposed to ultraviolet light (wavelength: 350 nm, ultraviolet intensity: 26.00 mW/cm ² ) using a xenon light source [manufactured by Asahi Bunko Co., Ltd., product number: MAX-303]. A series of operations in which the filament was irradiated with ultraviolet light (wavelength: 250 nm, ultraviolet intensity: 1.50 mW/cm ² ) for 5 seconds through a filter that blocks ultraviolet light with a wavelength of 254 nm or more was repeated 10 times. However, it was confirmed that all filaments were repeatedly deformed and restored to their original shape. This shows that each photoresponsive polyamide can repeatedly deform and restore its shape when repeatedly irradiated with ultraviolet rays of different wavelengths.

[Solubility of photoresponsive polyamide]
Add 1 mL of various solvents to 3 to 5 mg of each photoresponsive polyamide, let stand at room temperature (approximately 20°C), and after 1 hour has passed from the start of addition of the photoresponsive polyamide, the photoresponsive polyamide has dissolved in the solvent. I checked to see if it was. The results are shown in Table 2.

(Evaluation criteria for solubility of photoresponsive polyamide)
+: The photoresponsive polyamide is completely dissolved.
-: At least a part of the photoresponsive polyamide remains undissolved.

From the results shown in Table 2, it can be seen that the photoresponsive polyamides A to D obtained in each example all have excellent solubility in various organic solvents.

The photoresponsive polyamide of the present invention has photodeformability because it shows the behavior of deforming when irradiated with ultraviolet rays, and can be restored to its original shape by irradiating it with light rays (ultraviolet rays) having a wavelength different from that at which it exhibits the deforming behavior. It has the property of restoring its shape and can repeatedly deform and restore its shape when repeatedly irradiated with ultraviolet rays of different wavelengths. It is expected to be used in a variety of applications, including motors, light-driven actuators, artificial muscles that can be moved by optical signals, soft robots that can be moved by optical signals, and switches that respond to light.

In particular, the photoresponsive polyamide of the present invention can be produced by dividing sunlight into spectroscopy to extract a light beam that deforms the photoresponsive polyamide and a light beam that restores the photoresponsive polyamide, and utilizes these light beams to deform the photoresponsive polyamide. The shape deformation and restoration of photoresponsive polyamide is expected to be used in motors that do not require electricity.

Claims (3)

Formula (Ia):

(In the formula, R ¹ represents an optionally substituted alkylene group, an optionally substituted cycloalkylene group, or an optionally substituted arylene group)
Repeating unit and formula (Ib) represented by:

(In the formula, ^R2 represents a hydrogen atom, a hydroxyl group, a halogen atom, or an alkoxy group)
A photoresponsive polyamide having a repeating unit represented by: Formula (II):

(In the formula, R ¹ is an alkylene group that may have a substituent, a cycloalkylene group that may have a substituent, or an arylene group that may have a substituent, R ² is a hydrogen atom, (represents a hydroxyl group, halogen atom or alkoxy group)
The photoresponsive polyamide according to claim 1, having a repeating unit represented by: Formula (III):

(In the formula, R ¹ is an alkylene group that may have a substituent, a cycloalkylene group that may have a substituent, or an arylene group that may have a substituent, R ² is a hydrogen atom, (represents a hydroxyl group, halogen atom or alkoxy group)
An amide compound represented by

Images