Method for producing conductive polyamide composites

Abstract

This invention provides a method for producing conductive polyamide composites or conductive polyamide composite fibers that exhibit significantly superior conductivity compared to conventional conductive polyamide composites. [Solution] A method for producing a conductive polyamide composite according to one aspect of the present invention is characterized by bringing into contact an aqueous solution phase (X) containing water, a basic alkali metal compound, and a diamine with an organic solution phase (Y) containing an organic solvent and a dicarboxylic acid halide in the presence of a conductive polymer (A), and carrying out a polycondensation reaction at the interface between the aqueous solution phase (X) and the organic solution phase (Y).

Description

[Technical Field]

[0001] This invention relates to a method for producing conductive polyamide composites. [Background technology]

[0002] In recent years, conductive plastics have attracted considerable attention as electromagnetic shielding materials or antistatic materials in fields such as electronics and electrical engineering, as well as precision machinery.

[0003] Polyamides are known as engineering plastics with excellent mechanical and chemical properties. Although polyamides are not inherently conductive, it has been reported that by incorporating conductive particles into them, they can be used as conductive plastic materials useful for electromagnetic shielding or antistatic applications (for example, Patent Documents 1-3). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 60-108428 [Patent Document 2] Japanese Patent Application Publication No. 61-266460 [Patent Document 3] Japanese Patent Publication No. 2002-348468 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Conventional conductive polyamides are characterized by containing conductive particles, but there has been a problem in providing polyamides that exhibit excellent conductivity because it is difficult to uniformly disperse the conductive particles.

[0006] One aspect of the present invention aims to realize a method for producing a conductive polyamide composite or conductive polyamide composite fiber that exhibits significantly superior conductivity compared to conventional conductive polyamide composites. [Means for solving the problem]

[0007] As a result of diligent research, the inventors of this invention have found that the invention described below can solve the above problems, and have completed the present invention.

[0008] In other words, one aspect of the present invention relates to a method for producing a conductive polyamide composite as shown below. [1] A method for producing a conductive polyamide composite, comprising contacting an aqueous solution phase (X) containing water, a basic alkali metal compound, and a diamine with an organic solution phase (Y) containing an organic solvent and a dicarboxylic acid halide in the presence of a conductive polymer (A), and carrying out a polycondensation reaction at the interface between the aqueous solution phase (X) and the organic solution phase (Y). [2] The method for producing the conductive polymer (A) according to [1], wherein the conductive polymer (A) is a polythiophene-based conductive polymer. [3] The method for producing the polythiophene-based conductive polymer according to [2], wherein the polythiophene-based conductive polymer is a polythiophene-based self-doped conductive polymer. [4] The method for producing polythiophene (A1) according to [3], wherein the polythiophene-based self-doped conductive polymer is a self-doped polythiophene (A1) comprising at least one structural unit selected from the group consisting of a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2).

[0009] [ka]

[0010] [In the above general formula (1), M + R represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation. In the above general formulas (1) and (2), R represents an organic group with a total of 1 to 14 carbon atoms having at least one substituent selected from the group consisting of a sulfonic acid group and a phosphonic acid group. [5] The manufacturing method of the conductive polyamide composite according to any one of [1] to [4], wherein the content of the conductive polymer (A) in the aqueous solution phase (X) is 0.01% by mass to 5% by mass. [6] The manufacturing method of the conductive polyamide composite according to any one of [1] to [5], wherein the diamine is hexamethylenediamine. [7] The manufacturing method of the conductive polyamide composite according to any one of [1] to [6], wherein the dicarboxylic acid halide is adipic acid dichloride. [8] The manufacturing method of the conductive polyamide composite according to any one of [1] to [7], wherein the organic solvent is hexane or xylene. [9] A method for manufacturing a conductive polyamide composite fiber, characterized by pulling up a film of a conductive polyamide composite manufactured by the manufacturing method according to any one of [1] to [8] to form a filamentous material. [Effect of the Invention]

[0011] According to one aspect of the present invention, it is possible to realize a method for manufacturing a conductive polyamide composite or a conductive polyamide composite fiber that is significantly superior in conductivity to conventional conductive polyamide composites. [Embodiments for Carrying Out the Invention]

[0012] Hereinafter, an embodiment of the present invention will be described in detail. Unless otherwise specified in this specification, "A to B" representing a numerical range means "A or more and B or less".

[0013] [1. Manufacturing Method of Conductive Polyamide Composite] One aspect of the present invention relates to a method for producing a conductive polyamide composite, comprising contacting an aqueous solution phase (X) containing water, a basic alkali metal compound, and a diamine with an organic solution phase (Y) containing an organic solvent and a dicarboxylic acid halide in the presence of a conductive polymer (A), and carrying out a polycondensation reaction at the interface between the aqueous solution phase (X) and the organic solution phase (Y). In this specification, "conductive polyamide composite" is also simply referred to as "polyamide composite."

[0014] <Aqueous phase (X)> The aqueous solution phase (X) is characterized by containing water, a basic alkali metal compound, and a diamine.

[0015] The basic alkali metal compound is not particularly limited, but examples include alkali metal hydroxides, alkali metal bicarbonate salts, or alkali metal carbonate salts. The alkali metal hydroxide is not particularly limited, but examples include lithium hydroxide, sodium hydroxide, potassium hydroxide, or cesium hydroxide. The alkali metal bicarbonate salt is not particularly limited, but examples include lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, or cesium bicarbonate. The alkali metal carbonate salt is not particularly limited, but examples include lithium carbonate, sodium carbonate, potassium carbonate, or lithium carbonate. Of these, the basic alkali metal compound is preferably an alkali metal hydroxide, and more preferably sodium hydroxide or potassium hydroxide, in terms of its excellent ability to promote the polycondensation reaction. The basic alkali metal compound acts as an acid acceptor and can promote the polycondensation reaction by neutralizing the protons released by the polycondensation reaction of polyamides.

[0016] The basic alkali metal compound may be added after being prepared in advance as an aqueous solution. When adding an aqueous solution of the basic alkali metal compound in the preparation of the aqueous solution phase (X), it is not necessary to add water separately. The content of the basic alkali metal compound in the aqueous solution phase (X) is not particularly limited as long as the polycondensation reaction proceeds sufficiently, but for example, the content may be 0.1 to 10% by mass, preferably in the range of 0.5 to 5% by mass, and more preferably in the range of 1 to 4% by mass, with the aqueous solution phase (X) being 100% by mass.

[0017] The diamine is preferably a diamine having 4 to 8 carbon atoms, and is not particularly limited as long as it is a diamine monomer generally applicable to interfacial polycondensation. Examples include 1,4-diaminobutane, hexamethylenediamine, p-phenylenediamine, m-phenylenediamine, or m-xylylenediamine. Of these, hexamethylenediamine is preferred as the diamine because it yields a polyamide with excellent mechanical properties. The content of the diamine in the aqueous solution phase (X) is not particularly limited as long as the polycondensation reaction proceeds sufficiently, but for example, the lower limit of the content is preferably in the range of 2 to 10% by mass, and more preferably in the range of 3 to 6% by mass, with the aqueous solution phase (X) being 100% by mass.

[0018] The aforementioned water-soluble phase (X) may further contain other components such as water glass or a surfactant. These other components may be used individually or in combination of two or more. Regarding the content of the other components, for the sake of excellent operability, it is preferably 0.5 to 5% by mass, and more preferably 1 to 2% by mass, based on 100% by mass of the aqueous phase (X).

[0019] Water glass refers to a water-soluble glass whose main constituent elements are alkali metals, silicon, and oxygen, and which generally has the compositional formula Q2O·nSiO2 (where Q represents an alkali metal). In the above compositional formula, Q is preferably sodium or potassium. Furthermore, for excellent solubility in water, the range of n is preferably 1.2 ≤ n ≤ 4. By coexisting water glass in the aqueous solution phase (X), a fine and uniform composite of polyamide and glass is formed, and the mechanical strength of the resulting polyamide can be improved.

[0020] The aforementioned surfactants are not particularly limited, but examples include anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, fluorinated surfactants, or silicone-based surfactants.

[0021] The aforementioned anionic surfactants are not particularly limited, but examples include sodium lauryl alcohol sulfate or sodium dodecylbenzenesulfonate.

[0022] The cationic surfactant mentioned above is not particularly limited, but commercially available products can be used, or generally known products can be manufactured separately and used.

[0023] The aforementioned nonionic surfactants are not particularly limited, but examples include polyethylene glycol-type surfactants, acetylene glycol-type surfactants, polyhydric alcohol-type surfactants, and polymer-type nonionic surfactants.

[0024] The polyethylene glycol-type surfactants mentioned above are not particularly limited, but examples include higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, higher alkylamine ethylene oxide adducts, oil and fat ethylene oxide adducts, or polypropylene glycol ethylene oxide adducts.

[0025] The aforementioned acetylene glycol-type surfactants are not limited to any particular type, but examples include 2,4,7,9-tetramethyl-5-decine-4,7-diol, Surfinol® (manufactured by Air Products Co., Ltd.), Olfin® (manufactured by Nisshin Chemical Industry Co., Ltd.), and others.

[0026] The aforementioned polyhydric alcohol-type surfactants are not particularly limited, but examples include fatty acid esters of glycerol, fatty acid esters of pentaerythritol, fatty acid esters of sorbitol and sorbitan, fatty acid esters of sucrose, alkyl ethers of high alcohols, and fatty acid amides of alkanolamines.

[0027] The amphoteric surfactants mentioned above are not particularly limited, but examples include betaine-type amphoteric surfactants. Examples of betaine-type amphoteric surfactants are not particularly limited, but examples include alkyldimethyl betaine, lauryldimethyl betaine, stearyldimethyl betaine, lauryldihydroxyethyl betaine, etc.

[0028] The aforementioned fluorine-based surfactant is not particularly limited as long as it has a perfluoroalkyl group, but examples include Pluscoat® RY-2, perfluoroalkanes, perfluoroalkyl carboxylic acids, perfluoroalkyl sulfonic acids, or perfluoroalkyl ethylene oxide adducts.

[0029] The aforementioned silicone-based surfactants are not particularly limited, but examples include polyether-modified polydimethylsiloxane, polyether ester-modified polydimethylsiloxane, hydroxyl group-containing polyether-modified polydimethylsiloxane, acrylic group-containing polyether-modified polydimethylsiloxane, methacrylic group-containing polyether-modified polydimethylsiloxane, acrylic group-containing polyester-modified polydimethylsiloxane, methacrylic group-containing polyester-modified polydimethylsiloxane, perfluoropolyether-modified polydimethylsiloxane, perfluoropolyester-modified polydimethylsiloxane, silicone-modified acrylic compounds, or silicone-modified methacrylic compounds.

[0030] The aforementioned surfactants can promote polyamide polycondensation reactions by increasing the contact efficiency between monomers. Furthermore, some surfactants can also function as acid acceptors, thereby accelerating polyamide polycondensation reactions.

[0031] <Organic solution phase (Y)> The aforementioned organic solution phase (Y) is characterized by comprising an organic solvent and a dicarboxylic acid halide.

[0032] The aforementioned organic solvent is not particularly limited as long as it is one that is generally used in interfacial polycondensation, that is, one that is immiscible with water under the conditions of the interfacial polycondensation reaction. Examples include benzene, toluene, xylene, chloroform, dichloromethane, hexane, cyclohexane, tetrahydrofuran, or 1,3-dioxolane. Of these, hexane or xylene are preferred as the organic solvent because they are excellent at promoting the polycondensation reaction.

[0033] Regarding the dicarboxylic acid halide mentioned above, dicarboxylic acid halides having 4 to 12 carbon atoms are preferred, and are generally not particularly limited as long as they are monomers applicable to interfacial polycondensation. Examples include adipic acid dichloride, azelaic acid dichloride, sebacate acid dichloride, isophthaloyl dichloride, or terephthaloyl dichloride (in the case of isophthaloyl dichloride or terephthaloyl dichloride, one or more hydrogen atoms in the aromatic ring may be substituted with a halogen, nitro group, or alkyl group). Of these, adipic acid dichloride is preferred as the dicarboxylic acid halide because it yields a polyamide with excellent mechanical properties.

[0034] The content of dicarboxylic acid halides in the organic solution phase (Y) is not particularly limited as long as the polycondensation reaction proceeds sufficiently, but for example, the content is preferably in the range of 2.5 to 10% by mass, and more preferably in the range of 5 to 7.5% by mass, with the organic solution phase (Y) being 100% by mass.

[0035] The aforementioned organic solution phase (Y) may further contain other components such as nanocarbons and fillers. These other components may be used individually or in combination of two or more. The content of the other components is preferably 0.001 to 5% by mass, more preferably 0.003 to 2% by mass, and even more preferably 0.005 to 1% by mass, relative to 100% by mass of the organic solution phase (Y).

[0036] <Conductive polymer (A)> The conductive polymer (A) is not particularly limited, but examples include polythiophene-based conductive polymers or polyaniline-based conductive polymers. From the viewpoint of high conductivity, the conductive polymer (A) is preferably a polythiophene-based conductive polymer.

[0037] The aforementioned polythiophene-based conductive polymers can be broadly classified into polythiophene-based externally doped conductive polymers and polythiophene-based self-doped conductive polymers. An example of a polythiophene-based externally doped conductive polymer is a PEDOT / PSS aqueous dispersion solution obtained by polymerizing 3,4-ethylenedioxythiophene (EDOT) in an aqueous solution of polystyrene sulfonic acid (PSS), which acts as a dopant. This PEDOT / PSS aqueous dispersion solution is a conductive polymer in which PSS acts as a dopant. A polythiophene-based self-doped conductive polymer refers to a conductive polymer that exhibits conductivity even without an external dopant such as PSS. In one embodiment of the present invention, a polythiophene-based externally doped conductive polymer can also be used, but from the viewpoint of material processability and functionality, a polythiophene-based self-doped conductive polymer is preferred. The aforementioned polythiophene-based self-doped conductive polymer is more preferably a self-doped polythiophene (A1) containing at least one structural unit selected from the group consisting of the structural unit represented by the following general formula (1) and the structural unit represented by the following general formula (2), from the viewpoint of material processability and functionality.

[0038] [ka]

[0039] [In the above general formula (1), M + R represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation. In the above general formulas (1) and (2), R represents an organic group with a total of 1 to 14 carbon atoms having at least one substituent selected from the group consisting of a sulfonic acid group and a phosphonic acid group. R in general formulas (1) and (2) - This represents a state in which the sulfonic acid group or phosphonic acid group contained in R is ionized, and for general formula (1), M is used as its countercation. + This represents a state in which cations are ionically bonded.

[0040] In the above general formula (1), M + This represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation.

[0041] The aforementioned alkali metal ions are not particularly limited, but examples include lithium ions, sodium ions, potassium ions, or cesium ions.

[0042] The conjugate acid of the aforementioned amine compound is a hydron (H) in the amine compound. + This indicates a species formed by the addition of ammonium (NH4). The conjugate acid of the amine compound is not particularly limited as long as it is an amine compound that reacts with a sulfonic acid group or a phosphonic acid group to form a conjugate acid, but for example, ammonium (NH4) + Examples include methylammonium, dimethylammonium, trimethylammonium, ethylammonium, triethylammonium, n-propylammonium, isopropylammonium, n-butylammonium, hexylammonium, 2-hydroxyethylammonium, N,N-dimethyl-N-(2-hydroxyethyl)ammonium, N-methyl-N-(2-hydroxyethyl)ammonium, di(2-hydroxyethyl)ammonium, N-methyl-N,N-di(2-hydroxyethyl)ammonium, N,N,N-tri(2-hydroxyethyl)ammonium, 2,3-dihydroxypropylammonium, N-methyl-N-(2,3-dihydroxypropyl)ammonium, N,N-dimethyl-N-(2,3-dihydroxypropyl)ammonium, 1,4-butanediammonium, triisobutylammonium, triisopentylammonium, triisooctylammonium, imidazole cation, N-methylimidazole cation, 1,2-dimethylimidazole cation, pyridinium ion, picolinium ion, or rutidinium ion.

[0043] The aforementioned quaternary ammonium cations are not particularly limited, but examples include tetramethylammonium cation, tetraethylammonium cation, tetran-propylammonium cation, tetran-butylammonium cation, or tetran-hexylammonium cation.

[0044] In the above general formulas (1) and (2), R represents an organic group having a total of 1 to 14 carbon atoms and having at least one substituent selected from the group consisting of a sulfonic acid group and a phosphonic acid group. An organic group having a total of 1 to 14 carbon atoms can also be rephrased as a hydrocarbon group having a total of 1 to 14 carbon atoms, which may have substituents, and is not particularly limited, but examples include a methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group, isohexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, methoxymethyl group, ethoxymethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, isobutoxymethyl group, tert-butoxymethyl group, hexyloxymethyl group, isohexyloxymethyl group, heptyloxymethyl group, or octyloxymethyl group.

[0045] The organic group having a total of 1 to 14 carbon atoms and having at least one substituent selected from the group consisting of the aforementioned sulfonic acid group and phosphonic acid group is not particularly limited, but for example, methyl sulfonate, methyl phosphonate, ethyl 2-sulfonate, ethyl 2-phosphonate, propyl 3-sulfonate, propyl 3-phosphonate, propyl 2-sulfonate, propyl 2-phosphonate, butyl 4-sulfonate, butyl 4-phosphonate, butyl 3-sulfonate, butyl 3-phosphonate, hexyl 6-sulfonate, hexyl 6-phosphonate, hexyl 5-sulfonate, hexyl 5-phosphonate Examples include methoxymethyl sulfonate, methoxymethyl phosphonate, ethoxymethyl 2-sulfonate, ethoxymethyl 2-phosphonate, propoxymethyl 3-sulfonate, propoxymethyl 3-phosphonate, propoxymethyl 2-sulfonate, propoxymethyl 2-phosphonate, butoxymethyl 4-sulfonate, butoxymethyl 4-phosphonate, butoxymethyl 3-sulfonate, butoxymethyl 3-phosphonate, hexyloxymethyl 6-sulfonate, hexyloxymethyl 6-phosphonate, hexyloxymethyl 5-sulfonate, or hexyloxymethyl 5-phosphonate.

[0046] The structural unit represented by the above general formula (2) represents the self-doping state of the structural unit represented by the above general formula (1). This self-doping state is manifested by the sulfonic acid group or phosphonic acid group in the structural unit represented by the above general formula (1) acting as a p-type dopant. By containing structural units in the self-doping state, the polymer can exhibit conductivity without the addition of external dopants.

[0047] The self-doped polythiophene (A1) described above is not particularly limited, but it is preferable that it is a self-doped polythiophene (A2) that includes at least one structural unit selected from the group consisting of the structural unit represented by the following general formula (3) and the structural unit represented by the following general formula (4), in terms of excellent conductivity.

[0048] [Chemical formula]

[0049] [In General Formulas (3) and (4), R 2 represents a hydrogen atom, a methyl group, an ethyl group, a linear or branched alkyl group having 3 to 6 carbon atoms, or a fluorine atom. m represents an integer from 1 to 10. n represents 0 or 1. In General Formula (3), M + represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation.] In the above General Formulas (3) and (4), R 2 represents a hydrogen atom, a methyl group, an ethyl group, a linear or branched alkyl group having 3 to 6 carbon atoms, or a fluorine atom. m represents an integer from 1 to 10. n represents 0 or 1.

[0050] Regarding the above linear or branched alkyl group having 3 to 6 carbon atoms, there is no particular limitation, but examples include an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a cyclopentyl group, an n-hexyl group, a 2-ethylbutyl group, or a cyclohexyl group, etc.

[0051] In the above General Formula (3), M + represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation.

[0052] Regarding the definition and preferred range of the above M + , as well as the preferred ranges of the alkali metal ion, the conjugate acid of the amine compound, and the quaternary ammonium cation, they are synonymous with the definition and preferred range of M + in General Formula (1), as well as the preferred ranges of the alkali metal ion, the conjugate acid of the amine compound, and the quaternary ammonium cation, so the description is omitted here.

[0053] In one embodiment of the present invention, the conductive polymer (A) may exist in a dissolved form in the aqueous solution phase (X) and / or the organic solution phase (Y). In particular, it is preferable to carry out the interfacial polycondensation reaction with the conductive polymer (A) contained in the aqueous solution phase (X) because the conductive polymer (A) is easily incorporated into the polyamide.

[0054] <Manufacturing of conductive polyamide composites> A conductive polyamide composite according to one embodiment of the present invention is obtained by bringing the above-mentioned aqueous solution phase (X) and organic solution phase (Y) into contact in the presence of the above-mentioned conductive polymer (A), and by carrying out a polycondensation reaction at the interface between the aqueous solution phase (X) and the organic solution phase (Y).

[0055] Here, the method for preparing the aqueous solution phase (X) is not particularly limited, but each component may be mixed and homogenized by stirring or other means. In that case, other components may be added and mixed as needed. The method for preparing the organic solution phase (Y) is not particularly limited, but for example, dicarboxylic acid halide may be added to an organic solvent at room temperature and stirred.

[0056] In the production of the polyamide composite, it is preferable that both the aqueous solution phase (X) and the organic solution phase (Y) are homogeneous solvents in the absence of the conductive polymer (A).

[0057] In a manufacturing method according to one embodiment of the present invention, the reaction is carried out by contacting an aqueous solution phase (X) with an organic solution phase (Y). The aqueous solution phase (X) may be added to the organic solution phase (Y), or conversely, the organic solution phase (Y) may be added to the aqueous solution phase (X). The addition may be carried out in one step or in multiple steps. The addition may be carried out dropwise.

[0058] The conductive polymer (A) may be added in a form that dissolves in the aqueous solution phase (X) and / or the organic solution phase (Y) before contacting the aqueous solution phase (X) and the organic solution phase (Y). This allows polycondensation to occur with the conductive polymer present at and near the interface of the two solution phases, and the conductive polymer is uniformly incorporated into the resulting polyamide.

[0059] In a manufacturing method according to one embodiment of the present invention, the conductive polymer (A) may be present in either the aqueous solution phase (X) or the organic solution phase (Y), and there are no particular restrictions on its dissolution state, however, it is common for it to undergo polycondensation while dissolved in the aqueous solution phase (X). When the conductive polymer (A) is present in the aqueous solution phase (X), the content of the conductive polymer (A) is preferably in the range of 0.01 to 5% by mass, more preferably in the range of 0.1 to 4% by mass, and even more preferably in the range of 0.2 to 3% by mass, with the aqueous solution phase (X) being 100% by mass.

[0060] When the conductive polymer (A) is present in the organic solution phase (Y), the content of the conductive polymer (A) is preferably in the range of 0.01 to 5% by mass, more preferably in the range of 0.1 to 3% by mass, and even more preferably in the range of 0.2 to 2% by mass, with the organic solution phase (Y) being 100% by mass.

[0061] When the conductive polymer (A) is present in both the aqueous solution phase (X) and the organic solution phase (Y), the content of the conductive polymer (A) is preferably in the range of 0.01 to 5% by mass, more preferably in the range of 0.1 to 4% by mass, and even more preferably in the range of 0.2 to 3% by mass, with the total of the aqueous solution phase (X) and the organic solution phase (Y) being 100% by mass.

[0062] The temperature of the polycondensation reaction in the manufacturing method according to one embodiment of the present invention is not particularly limited, but a temperature range of -5 to 70°C is preferred. Since the rate of polycondensation reaction of polyamide is extremely fast, it is possible to carry out the polycondensation reaction at room temperature. Therefore, the reaction can be carried out at room temperature without the need for heating equipment.

[0063] The reaction time in the manufacturing method according to one embodiment of the present invention depends on the reaction rate of the monomer species used, but usually, a precipitate is formed instantaneously by contacting the aqueous solution phase with the organic solution phase, and the reaction operation can be completed in, for example, 2 to 30 minutes.

[0064] The polyamide composite obtained in this manner contains the conductive polymer (A) described above. The content of the conductive polymer (A) is preferably in the range of 2.5 to 25% by mass, more preferably in the range of 5 to 20% by mass, and even more preferably in the range of 10 to 15% by mass, with the polyamide composite being 100% by mass.

[0065] The polyamide composite obtained by the above method can be separated by removing components other than the polyamide composite from the reaction mixture. One method for separating the polyamide composite is to filter the reaction mixture. Another method is to use tweezers or the like to grasp and lift the polyamide composite film formed at the interface between the aqueous solution phase (X) and the organic solution phase (Y) (this method is also referred to as "Method (A)" in this specification). The location where the polyamide composite film is grasped is not particularly limited, but for example, one end or the center can be grasped.

[0066] The polyamide composite separated by the above method is preferably washed with an organic solvent and / or water to remove unreacted monomers and / or by-products. Examples of organic solvents used for washing include acetone and methanol. The separated polyamide composite is preferably dried at a temperature above room temperature. Drying may be carried out under reduced pressure or vacuum.

[0067] [2. Method for producing conductive polyamide composite fibers] One embodiment of the present invention also includes a method for producing conductive polyamide composite fibers. In this specification, "conductive polyamide composite fibers" is also simply referred to as "polyamide composite fibers." The method for producing polyamide composite fibers is not particularly limited, but one method is to pull up the film of the polyamide composite to form a thread-like material. The resulting thread-like material is the polyamide composite fiber. In this method, it is preferable that the film of the polyamide composite is pulled up continuously. In this specification, "pulling up continuously" means continuing to pull up the film of the polyamide composite until the film becomes thread-like. Here, "thread-like" refers to a state in which the pulled-up film of the polyamide composite reaches, for example, 5 cm or more.

[0068] The method for producing the polyamide composite fibers described above will be specifically explained below. In method (A) above, by slowing down the rate at which the conductive polyamide composite film is pulled up, a new polycondensation reaction can be continuously carried out at the interface between the aqueous solution phase (X) and the organic solution phase (Y). By continuously pulling up the polyamide composite produced by the polycondensation reaction while the polycondensation reaction is carried out in this manner, thread-like polyamide composite fibers can be produced. The method for continuously pulling up the polyamide composite film is not particularly limited as long as a thread-like material can be formed, but for example, one method is to grasp one end or the center of the polyamide composite film with tweezers and continuously pull it up, and then wind it onto a test tube or the like while slowly rotating it so as not to break it. When using a test tube for winding, a larger test tube is preferable.

[0069] Polyamide composite fibers can also be manufactured by methods other than those described above, such as injection molding. The injection molding method is not particularly limited and can be carried out by conventionally known methods.

[0070] The polyamide composite fibers produced by the above method are preferably washed with an organic solvent or water and dried to remove unreacted monomers and / or by-products. The organic solvent and drying conditions used for washing are the same as those for the polyamide composite, so a detailed explanation is omitted here.

[0071] The conductive polyamide composite or conductive polyamide composite fiber obtained by the manufacturing method according to one embodiment of the present invention has excellent conductivity and can be effectively used, for example, as an electromagnetic wave shielding material, an antistatic material, a conductive filter material, or a planar heating element. [Examples]

[0072] Examples are shown below, but the present invention is not limited to these examples.

[0073] [Electrical conductivity measurement of conductive polyamide composite fibers] The polyamide composite fibers obtained in the following examples and comparative examples were washed with acetone for 1 minute, then with water for 1 minute. They were then dried at room temperature for 24 hours. The diameter of the washed and dried polyamide composite fibers was measured five times using a micrometer, and the cross-sectional area was calculated from the average diameter. The polyamide composite fibers were clamped between two wooden clip electrodes coated with silver paste. The distance between the electrodes was 0.5 cm. The two electrodes were connected to a potentiostat HZ-5000, and the resistance was measured using the two-terminal method. The conductivity was calculated from the resistance of the polyamide composite fibers measured using this method, based on the following formula. The calculation results are shown in Table 1. σ = L / (R × S) σ: conductivity [S / cm], L: distance between electrodes [cm], R: resistance [Ω], S: cross-sectional area of ​​fiber [cm] 2 ] [Materials used in the examples and comparative examples] (Aqueous phase (X)) • Water and basic alkali metal compounds: Sodium hydroxide aqueous solution • Diamine: Hexamethylenediamine (Organic solution phase (Y)) • Organic solvents: Hexane or xylene • Dicarboxylic acid halide: Adipic acid dichloride (Conductive polymer (A)) ·A conductive polymer containing two or more structural units selected from the group consisting of the structural unit represented by the following general formula (5) and the structural unit represented by the following general formula (6), in accordance with Synthesis Example 1 and Synthesis Example 2 of the publicly available document (Japanese Patent Publication No. 2019-196443). This corresponds to the above conductive polymer (A), self-doped polythiophene (A1), and self-doped polythiophene (A2). However, R 2 =methyl group, M + =Hydrogen ion, m=2. Hereafter referred to as "Polythiophene (A3)".) was synthesized.

[0074] [ka]

[0075] [Example 1] To 20.727 g (20 mL) of an aqueous sodium hydroxide solution, 0.420 g (0.5 mL) of hexamethylenediamine and 0.053 g of the above-mentioned polythiophene (A3) were added and stirred until homogeneous to obtain aqueous phase (X). The content of Selftron S100 in the aqueous phase (X) was 0.25% by mass, with the total aqueous phase (X) being 100% by mass. Next, 0.63 g (0.5 mL) of adipic acid dichloride was added to 13.2 g (20 mL) of hexane to obtain an organic solution phase (Y). The organic solution phase (Y) was poured into the aqueous solution phase (X) using a glass rod, and a polyamide composite film was obtained at the interface of the two solutions. Here, since polythiophene (A3) corresponds to the conductive polymer (A) according to one embodiment of the present invention, the obtained film corresponds to the conductive polyamide composite according to one embodiment of the present invention. Next, the obtained film was grasped with tweezers and continuously pulled up to obtain thread-like polyamide composite fibers.

[0076] [Example 2] In Example 1, the same procedure as in Example 1 was followed except that the amount of polythiophene (A3) was changed to 0.106 g to obtain polyamide composite fibers. In the aqueous solution phase (X), the concentration of polythiophene (A3) was 0.5% by mass, with the entire aqueous solution phase (X) being 100% by mass.

[0077] [Example 3] In Example 1, the same procedure was followed except that the amount of polythiophene (A3) was changed to 0.159 g to obtain polyamide composite fibers. In the aqueous solution phase (X), the concentration of polythiophene (A3) was 0.75% by mass, with the entire aqueous solution phase (X) being 100% by mass.

[0078] [Example 4] In Example 1, the same procedure was followed except that the amount of polythiophene (A3) was changed to 0.21 g to obtain polyamide composite fibers. In the aqueous solution phase (X), the concentration of polythiophene (A3) was 0.98% by mass, with the entire aqueous solution phase (X) being 100% by mass.

[0079] [Example 5] In Example 1, the same procedure was followed except that the amount of polythiophene (A3) was changed to 0.318 g to obtain polyamide composite fibers. In the aqueous solution phase (X), the concentration of polythiophene (A3) was 1.48% by mass, with the entire aqueous solution phase (X) being 100% by mass.

[0080] [Example 6] In Example 1, the same procedure was followed except that the amount of polythiophene (A3) was changed to 0.42 g to obtain a polyamide composite fiber. In the aqueous solution phase (X), the concentration of polythiophene (A3) was 1.95% by mass, with the entire aqueous solution phase (X) being 100% by mass.

[0081] [Example 7] In Example 6, the same procedure was followed except that 17.6 g (20 mL) of xylene was used instead of 13.2 g (20 mL) of hexane to obtain polyamide composite fibers. In the aqueous solution phase (X), the concentration of polythiophene (A3) was 1.95% by mass, with the entire aqueous solution phase (X) being 100% by mass.

[0082] [Comparative Example 1] In Example 1, the same procedure was followed except that polythiophene (A3) was not added, to obtain polyamide composite fibers.

[0083] [Table 1]

[0084] As can be seen from Table 1, the examples containing polythiophene (A3) showed higher conductivity compared to the comparative example without polythiophene (A3), up to 10 4 The conductivity increased by a factor of two. Furthermore, comparing Examples 1 to 7, it was found that the higher the content of conductive polymer (A) in the aqueous solution phase (X), the higher the conductivity. From these findings, it became clear that by contacting an aqueous solution phase (X) containing water, a basic alkali metal compound, and a diamine with an organic solution phase (Y) containing an organic solvent and a dicarboxylic acid halide in the presence of polythiophene (A3), and carrying out a polycondensation reaction at the interface between the aqueous solution phase (X) and the organic solution phase (Y), conductive polyamide composites and conductive polyamide composite fibers with excellent conductivity can be obtained. [Industrial applicability]

[0085] The present invention can be used, for example, in adhesives, antistatic materials, LCDs, organic ELs, or transparent electrodes.

Claims

1. A method for producing a conductive polyamide composite, comprising contacting an aqueous solution phase (X) containing water, a basic alkali metal compound, and a diamine with an organic solution phase (Y) containing an organic solvent and a dicarboxylic acid halide in the presence of a conductive polymer (A), and carrying out a polycondensation reaction at the interface between the aqueous solution phase (X) and the organic solution phase (Y).

2. The method for producing a product according to claim 1, wherein the conductive polymer (A) is a polythiophene-based conductive polymer.

3. The manufacturing method according to claim 2, wherein the polythiophene-based conductive polymer is a polythiophene-based self-doped conductive polymer.

4. The method for producing a self-doped conductive polymer according to claim 3, wherein the polythiophene-based self-doped conductive polymer is a self-doped polythiophene (A1) comprising at least one structural unit selected from the group consisting of a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2). 【Chemistry 1】 [In the above general formula (1), M ＋ R represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation. In the above general formulas (1) and (2), R represents an organic group with a total of 1 to 14 carbon atoms having at least one substituent selected from the group consisting of a sulfonic acid group and a phosphonic acid group.

5. A method for producing a conductive polyamide composite according to claim 1, characterized in that the content of the conductive polymer (A) in the aqueous solution phase (X) is 0.01% by mass to 5% by mass.

6. The method for producing a conductive polyamide composite according to claim 1, wherein the diamine is hexamethylenediamine.

7. The method for producing a conductive polyamide composite according to claim 1, wherein the dicarboxylic acid halide is adipic acid dichloride.

8. The method for producing a conductive polyamide composite according to claim 1, wherein the organic solvent is hexane or xylene.

9. A method for producing conductive polyamide composite fibers, characterized by pulling up a film of conductive polyamide composite manufactured by the manufacturing method described in claim 1 to form a thread-like material.

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