WO2015111755A1

WO2015111755A1 - Method for manufacturing conductive nanofiber

Info

Publication number: WO2015111755A1
Application number: PCT/JP2015/052192
Authority: WO
Inventors: 島田　直樹; 幸治中根; 信男小形; 小島　圭介
Original assignee: 国立大学法人福井大学; 日産化学工業株式会社
Priority date: 2014-01-27
Filing date: 2015-01-27
Publication date: 2015-07-30
Also published as: JPWO2015111755A1; JP6571008B2

Abstract

The problem addressed by the present invention is to provide a method for manufacturing a conductive nanofiber that can produce a conductive nanofiber that has sufficient conductivity using various types of plating metal and plating fluids without complicated operations. The problem is addressed by a method for manufacturing a conductive nanofiber characterized by including a fiber spinning step for fabricating the nanofiber according to an electrospinning process with a resin composition that includes (a) a thermoplastic resin, (b) a hyperbranched polymer having ammonium groups at molecular ends and a weight average molecular weight of 1,000 - 5,000,000, and (c) fine metal particles as the spinning material and a plating step for electroless plating of the nanofiber fabricated in the fiber spinning step.

Description

Method for producing conductive nanofiber

The present invention relates to a method for producing conductive nanofibers by using a resin composition in which a hyperbranched polymer and metal fine particles are blended in a thermoplastic resin as a spinning material, and subjecting the resin composition to electrostatic spinning and electroless plating.

In recent years, in applications such as smart textiles and electromagnetic shielding materials, there is a great demand for light and flexible conductive materials, and conductive fibers can be cited as materials that satisfy these properties.
Conventionally, as a method for imparting conductivity to a fiber material, for example, an electroless plating process on the surface of the fiber material is known. However, electroless plating usually requires a pre-plating process including etching, conditioning, catalyzing, acceleration, and other processes, so that the manufacturing process is complicated and expensive. In addition, when a chemical etching process is performed, since a chemical such as chromic acid or an alkali metal hydroxide solution is used, a waste liquid process is required.

In addition, as a technique for imparting conductivity to the nanofibers produced by the electrospinning method, for example, a method of imparting conductivity by irradiating the nanofibers with ions (Patent Document 1), and spinning by the electrospinning method. Nylon 6 nanofibers are electrolessly plated (Non-patent Document 1), a conductive polymer polypyrrole is used to produce nanofibers by electrospinning (Non-patent Document 2), and palladium chloride is used. An example (Patent Document 2) in which electroless nickel plating is performed on nanofibers mixed with a resin and manufactured by an electrospinning method is disclosed. Furthermore, after producing nanofibers by electrospinning method, the nanofiber surface is treated with iodine to form metal iodide composite organic nanofibers, and further, the metal iodide is reduced to a metal body, followed by electroless plating treatment. Examples are also disclosed (Patent Document 3).

JP 2009-138305 A JP 2010-037592 A JP2011-236512A

However, the surface resistance of the conductive nanofiber obtained by the technique of Patent Document 1 is large, and the electrical conductivity is insufficient for use as a conductive material. In the technique of Non-Patent Document 1, etching of the nanofiber surface is performed by low-temperature oxygen plasma treatment, and this plasma treatment apparatus is very expensive, and the plasma treatment performed under vacuum is a batch type, Not suitable for industrial mass production. Furthermore, the conductivity of the conductive polymer disclosed in Non-Patent Document 2 is lower than that of metal, and the electrical conductivity is still insufficient as a conductive material. Further, the method of Patent Document 2 cannot be plated depending on the type of plating solution or the type of metal to be plated. Furthermore, in the method of Patent Document 3, the process before plating is complicated.

As described above, it is difficult to ensure sufficient conductivity with the method using conductive fine particles or conductive polymer, and the electroless plating method using a complex as a catalyst is an activation treatment such as a reduction treatment. And the operation is complicated, and there is a problem that plating cannot be performed depending on the type of plating metal and the type of plating solution.
That is, there has been a demand for a method for producing conductive nanofibers that can use various kinds of plating metal species and plating solutions for conductive nanofibers having sufficient conductivity without complicated operations.

As a result of diligent studies to achieve the above object, the present inventors have obtained a result obtained by mixing a hyperbranched polymer having an ammonium group at the molecular terminal and a metal fine particle with a thermoplastic resin as a matrix polymer and electrostatic spinning. By applying electroless plating to the nanofibers, it is possible to obtain nanofibers with sufficient electrical conductivity as a conductive material, and electroless plating can be performed without restricting the type of plating metal or plating solution As a result, the present invention was completed.

That is, the present invention provides the first aspect as follows:
A resin composition comprising (a) a thermoplastic resin, (b) a hyperbranched polymer having an ammonium group at the molecular end and a weight average molecular weight of 1,000 to 5,000,000, and (c) metal fine particles. The present invention relates to a method for producing conductive nanofibers, which includes a spinning step of producing nanofibers according to an electrospinning method as a spinning material, and a plating step of performing electroless plating treatment of the nanofibers produced in the step.
As a second aspect, the present invention relates to the production method according to the first aspect, in which the ammonium group of the (b) hyperbranched polymer is attached to the metal fine particles (c) to form a complex.
As a 3rd viewpoint, the said (b) hyperbranched polymer is related with the manufacturing method as described in a 1st viewpoint or a 2nd viewpoint which is a hyperbranched polymer represented by Formula [1].

(In the formula, each R ¹ independently represents a hydrogen atom or a methyl group, and R ^{2 to} R ⁴ each independently represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. , An arylalkyl group having 7 to 20 carbon atoms or — (CH ₂ CH ₂ O) _m R ⁵ (wherein R ⁵ represents a hydrogen atom or a methyl group, and m represents an integer of 2 to 100). (The alkyl group and arylalkyl group may be substituted with an alkoxy group, a hydroxy group, an ammonium group, a carboxyl group, or a cyano group), or two groups of R ^{2 to} R ⁴ may be bonded together. Represents a linear, branched or cyclic alkylene group, or R ^{2 to} R ⁴ may form a ring together with the nitrogen atom to which they are bonded, and X ⁻ represents an anion. Where n is a repetition A number of by unit structure represents an integer of 5 to 100,000, ^{A 1} represents a structure represented by the formula [2].)

(In the formula, A ² represents a linear, branched or cyclic alkylene group having 1 to 30 carbon atoms which may contain an ether bond or an ester bond, and Y ^{1 to} Y ⁴ are each independently hydrogen. And represents an atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a nitro group, a hydroxy group, an amino group, a carboxyl group, or a cyano group.
As a 4th viewpoint, the said (b) hyperbranched polymer is related with the manufacturing method as described in a 3rd viewpoint which is a hyperbranched polymer represented by Formula [3].

(Wherein R ¹ , R ^{2 to} R ⁴ and n represent the same meaning as described above.)
As a fifth aspect, the metal fine particles (c) include iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), tin (Sn), platinum ( The manufacturing method according to any one of the first aspect to the fourth aspect, wherein the fine particles are at least one metal selected from the group consisting of Pt) and gold (Au).
As a sixth aspect, the present invention relates to the manufacturing method according to the fifth aspect, wherein the metal fine particles (c) are palladium fine particles.
As a seventh aspect, the present invention relates to the production method according to any one of the first to sixth aspects, wherein the (c) metal fine particles are fine particles having an average particle diameter of 1 to 100 nm.
As an eighth aspect, the present invention relates to the production method according to any one of the first aspect to the seventh aspect, wherein the (a) thermoplastic resin is polyvinylidene fluoride.
As a ninth aspect, the present invention relates to the production method according to any one of the first aspect to the eighth aspect, wherein the nanofiber has an average diameter of 50 to 2,000 nm.
As a 10th viewpoint, it is related with the manufacturing method as described in any one of a 1st viewpoint thru | or a 9th viewpoint including the 2nd plating process which performs another electroless-plating process after the said plating process.
As an eleventh aspect, the present invention relates to the manufacturing method according to the tenth aspect, in which the plating step is an electroless copper plating treatment and the second plating step is an electroless tin plating treatment.
As a twelfth aspect, the spinning step relates to the production method according to any one of the first aspect to the eleventh aspect, which is a process of producing a nanofiber aggregate as a nanofiber.
As a 13th viewpoint, it is related with the electroconductive nanofiber produced by the manufacturing method as described in any one of a 1st viewpoint thru | or a 12th viewpoint.
As a 14th viewpoint, it is related with the electroconductive nanofiber assembly produced by the manufacturing method as described in a 12th viewpoint.
As a fifteenth aspect, the present invention relates to the conductive nanofiber assembly according to the fourteenth aspect, which has a volume resistance value of 1 × 10 ⁴ Ω · cm or less.

According to the present invention, in a simple process of electrostatic spinning using a thermoplastic resin containing a specific hyperbranched polymer and fine metal particles as a spinning material, the resulting nanofibers are immersed in an electroless plating bath. Conductive nanofibers excellent in electrical conductivity can be easily obtained. For this reason, it is not bothered by the necessity of the complicated pre-processing process required for the conventional electroless-plating process, the complexity of a manufacturing process, and cost increase.
Moreover, the manufacturing method of this invention can be electroless-plated with various plating metal seed | species, and can obtain the electroconductive nanofiber which is excellent in electrical conductivity using a wide variety of plating solutions.
According to the production method of the present invention, a conductive nanofiber having a very low volume resistance value of 1 × 10 ⁴ Ω · cm or less and satisfying electrical conductivity as a conductive material and an aggregate thereof are provided. be able to.

In addition, since the conductive nanofiber aggregate of the present invention has a very low volume resistance as described above, it can be suitably used for high capacity battery electrodes, sensor electrodes, antistatic sheets, electromagnetic wave shields and the like.

FIG. 1 is a diagram showing a ¹ H NMR spectrum of a hyperbranched polymer (HPS-Cl) having a chlorine atom at the molecular end obtained in Production Example 1. FIG. 2 is a diagram showing a ¹³ C NMR spectrum of a hyperbranched polymer (HPS-N (Me) ₂ OctCl) having a dimethyloctylammonium group at the molecular end obtained in Production Example 2. FIG. 3 is a diagram showing a ¹³ C NMR spectrum of a hyperbranched polymer (HPS-NOct ₃ Cl) having a trioctylammonium group at the molecular end obtained in Production Example 4. FIG. 4 is a diagram showing an SEM image of the nanofiber mat obtained in Example 1. 5 is a view showing an SEM image of the nanofiber mat obtained in Example 7. FIG.

Hereinafter, the present invention will be described in detail.
The method for producing conductive nanofibers of the present invention includes a spinning step of producing nanofibers according to an electrospinning method using a resin composition described later as a spinning material, and a plating step of performing electroless plating treatment of the nanofibers produced in the above steps. It is characterized by including. Conductive nanofibers produced by the production method of the present invention are also objects of the present invention.
The resin composition used in the method for producing conductive nanofibers of the present invention comprises (a) a thermoplastic resin, (b) an ammonium group at the molecular end, and a weight average molecular weight of 1,000 to 5,000,000. A hyperbranched polymer, and (c) metal fine particles.

[Resin composition]
<(A) Thermoplastic resin>
The thermoplastic resin used in the present invention is not particularly limited. For example, PE (polyethylene), PP (polypropylene), EVA (ethylene-vinyl acetate copolymer), EVOH (ethylene-vinyl alcohol copolymer), PVA (polyvinyl). Alcohol), EEA (ethylene-ethyl acrylate copolymer), PVDF (polyvinylidene fluoride), polyvinylidene fluoride-hexafluoropropylene copolymer, and other polyolefin resins; PS (polystyrene), HIPS (high impact polystyrene), Polystyrene resins such as AS (acrylonitrile-styrene copolymer), ABS (acrylonitrile-butadiene-styrene copolymer), SBS (styrene-butadiene-styrene copolymer), MS (methyl methacrylate-styrene copolymer) Polycarbonate resin; Polyamide resin; Polyimide resin; Polyurethane resin such as PUE (polyurethane elastomer); (Meth) acrylic resin such as PMMA (polymethyl methacrylate); PAN (polyacrylonitrile); PET (polyethylene terephthalate), poly Polyethylene resins such as butylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, PLA (polylactic acid), poly-3-hydroxybutyric acid, polycaprolactone, polybutylene succinate, polyethylene succinate / adipate; PEO (polyethylene oxide); polyphenylene Ether resin; modified polyphenylene ether resin; polyacetal resin; PES (polyether sulfone) resin, polysulfone resin; E double sulfide resins, polyvinyl alcohol resins; polyglycolic acid; modified starch; cellulose acetate, cellulose triacetate; chitin, chitosan; lignin and the like.
Among them, it is preferable to use polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer and polyurethane resin as the thermoplastic resin.

<(B) Hyperbranched polymer>
The hyperbranched polymer used in the resin composition used in the present invention is a polymer having an ammonium group at the molecular end and a weight average molecular weight of 1,000 to 5,000,000. The hyperbranched polymer represented by [1] is mentioned.

In the above formula [1], R ¹ represents a hydrogen atom or a methyl group independently.
R ^{2 to} R ⁴ are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, or — ( CH ₂ CH ₂ O) _m R ⁵ (wherein R ⁵ represents a hydrogen atom or a methyl group, and m represents an arbitrary integer of 2 to 100). The alkyl group and arylalkyl group may be substituted with an alkoxy group, a hydroxy group, an ammonium group, a carboxyl group, or a cyano group. And ^two of R ^{2 to} R ⁴ together represent a linear, branched or cyclic alkylene group, or R ^{2 to} R ⁴ together with the nitrogen atom to which they are attached. To form a ring.
X ⁻ represents an anion, and n represents the number of repeating unit structures, and represents an integer of 5 to 100,000.

Examples of the linear alkyl group having 1 to 20 carbon atoms in R ^{2 to} R ⁴ include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n -Heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n -Heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group and the like. Among them, in the production method of the present invention, in the plating step described later, (b) the hyperbranched polymer in the resin composition used as the spinning material is less likely to elute into the electroless plating solution and has 8 or more carbon atoms. Group is preferable, and n-octyl group is particularly preferable.
Examples of the branched alkyl group include isopropyl group, isobutyl group, sec-butyl group, tert-butyl group and the like.
Examples of the cyclic alkyl group include a cyclopentyl ring and a group having a cyclohexyl ring structure.
Examples of the arylalkyl group having 7 to 20 carbon atoms in R ^{2 to} R ⁴ include a benzyl group and a phenethyl group.
Further, examples of the linear alkylene group in which ^two of R ^{2 to} R ⁴ are combined include a methylene group, an ethylene group, an n-propylene group, an n-butylene group, and an n-hexylene group. It is done. Examples of the branched alkylene group include an isopropylene group, an isobutylene group, and a 2-methylpropylene group. Examples of the cyclic alkylene group include alicyclic aliphatic groups having a monocyclic, polycyclic or bridged cyclic structure having 3 to 30 carbon atoms. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo, or pentacyclo structure having 4 or more carbon atoms. These alkylene groups may contain a nitrogen atom, a sulfur atom or an oxygen atom in the group.
The ring formed by R ^{2 to} R ⁴ together with the nitrogen atom bonded to them in the structure represented by the formula [1] may contain a nitrogen atom, a sulfur atom or an oxygen atom in the ring. For example, pyridine ring, pyrimidine ring, pyrazine ring, quinoline ring, bipyridyl ring and the like can be mentioned.
Examples of combinations of R ^{2 to} R ⁴ include [methyl group, methyl group, methyl group], [methyl group, methyl group, ethyl group], [methyl group, methyl group, n-butyl group], [methyl group] Group, methyl group, n-hexyl group], [methyl group, methyl group, n-octyl group], [methyl group, methyl group, n-decyl group], [methyl group, methyl group, n-dodecyl group], [Methyl group, methyl group, n-tetradecyl group], [methyl group, methyl group, n-hexadecyl group], [methyl group, methyl group, n-octadecyl group], [ethyl group, ethyl group, ethyl group], [N-butyl group, n-butyl group, n-butyl group], [n-hexyl group, n-hexyl group, n-hexyl group], [n-octyl group, n-octyl group, n-octyl group] Among them, [methyl group, methyl group, - octyl], [n- octyl group, n- octyl group, a combination of n- octyl group] are preferable.
The X ⁻ anion is preferably a halide ion, PF ₆ ⁻ , BF ₄ ⁻ or perfluoroalkanesulfonate.

In the above formula [1], A ¹ represents a structure represented by the following formula [2].

In the above formula [2], A ² represents a linear, branched or cyclic alkylene group having 1 to 30 carbon atoms which may contain an ether bond or an ester bond.
Y ^{1 to} Y ⁴ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a nitro group, a hydroxy group, an amino group, a carboxyl group, or a cyano group. To express.

Specific examples of the alkylene group of A ² include linear alkylene groups such as methylene group, ethylene group, n-propylene group, n-butylene group and n-hexylene group, isopropylene group, isobutylene group, 2-methyl group. Examples include branched alkylene groups such as propylene groups. Examples of the cyclic alkylene group include alicyclic aliphatic groups having a monocyclic, polycyclic and bridged cyclic structure having 3 to 30 carbon atoms. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo, or pentacyclo structure having 4 or more carbon atoms. For example, structural examples (a) to (s) of the alicyclic portion of the alicyclic aliphatic group are shown below.

Examples of the alkyl group having 1 to 20 carbon atoms of Y ^{1 to} Y ^{4 in} the above formula [2] include a methyl group, an ethyl group, an isopropyl group, a cyclohexyl group, and an n-pentyl group. Examples of the alkoxy group having 1 to 20 carbon atoms include methoxy group, ethoxy group, isopropoxy group, cyclohexyloxy group, n-pentyloxy group and the like. Y ^{1 to} Y ⁴ are preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.

Incidentally, it is preferable that the A ¹ is a structure represented by the following formula [4].

Preferably, the hyperbranched polymer used in the present invention includes a hyperbranched polymer represented by the following formula [3].

In the above formula ^{^{[3], R 1, R}} 2 to ^{R 4} and n are as defined above.

The hyperbranched polymer having an ammonium group at the molecular end used in the present invention can be obtained, for example, by reacting an amine compound with a hyperbranched polymer having a halogen atom at the molecular end.
A hyperbranched polymer having a halogen atom at the molecular end can be produced from a hyperbranched polymer having a dithiocarbamate group at the molecular end in accordance with the description in WO 2008/029688. As the hyperbranched polymer having a dithiocarbamate group at the molecular end, a commercially available product can be used, and Hypertech (registered trademark) HPS-200 manufactured by Nissan Chemical Industries, Ltd. can be preferably used.

The amine compounds that can be used in this reaction are, as primary amines, methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, n-pentylamine, n -Hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine , N-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-nonadecylamine, n-eicosylamine and other aliphatic amines; cyclopentylamine, cyclohexylamine and other alicyclic amines; benzylamine, phenethylamine and the like No Alkylamines; anilines such as aniline, pn-butylaniline, p-tert-butylaniline, pn-octylaniline, pn-decylaniline, pn-dodecylaniline, pn-tetradecylaniline Naphthylamines such as 1-naphthylamine and 2-naphthylamine, aminoanthracenes such as 1-aminoanthracene and 2-aminoanthracene, aminoanthraquinones such as 1-aminoanthraquinone, amino such as 4-aminobiphenyl and 2-aminobiphenyl Biphenyls, aminofluorenes such as 2-aminofluorene, 1-amino-9-fluorenone, 4-amino-9-fluorenone, aminoindanes such as 5-aminoindan, aminoisoquinolines such as 5-aminoisoquinoline, 9 -Ami Aromatic amines such as amino-phenanthrene such as phenanthrene and the like. Further, N- (tert-butoxycarbonyl) -1,2-ethylenediamine, N- (tert-butoxycarbonyl) -1,3-propylenediamine, N- (tert-butoxycarbonyl) -1,4-butylenediamine, N -(Tert-butoxycarbonyl) -1,5-pentamethylenediamine, N- (tert-butoxycarbonyl) -1,6-hexamethylenediamine, N- (2-hydroxyethyl) amine, N- (3-hydroxypropyl) And amine compounds such as amine, N- (2-methoxyethyl) amine, and N- (2-ethoxyethyl) amine.

Secondary amines include dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine, di-n-pentylamine, ethylmethylamine, methyl- n-propylamine, methyl-n-butylamine, methyl-n-pentylamine, methyl-n-octylamine, methyl-n-decylamine, methyl-n-dodecylamine, methyl-n-tetradecylamine, methyl-n- Hexadecylamine, methyl-n-octadecylamine, ethylisopropylamine, ethyl-n-butylamine, ethyl-n-pentylamine, ethyl-n-octylamine, di-n-hexylamine, di-n-octylamine, di -N-dodecylamine, di-n-hex Aliphatic amines such as decylamine and di-n-octadecylamine; Cycloaliphatic amines such as dicyclohexylamine; Aralkylamines such as dibenzylamine; Aromatic amines such as diphenylamine; Nitrogen such as phthalimide, pyrrole, piperidine, piperazine and imidazole And a containing heterocyclic compound. Furthermore, bis (2-hydroxyethyl) amine, bis (3-hydroxypropyl) amine, bis (2-ethoxyethyl) amine, bis (2-propoxyethyl) amine and the like can be mentioned.

Tertiary amines include trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-octylamine, tri-n-dodecyl. Amine, dimethylethylamine, dimethyl-n-butylamine, dimethyl-n-hexylamine, dimethyl-n-octylamine, dimethyl-n-decylamine, diethyl-n-decylamine, dimethyl-n-dodecylamine, dimethyl-n-tetradecyl Aliphatic amines such as amine, dimethyl-n-hexadecylamine, dimethyl-n-octadecylamine, dimethyl-n-eicosylamine; pyridine, pyrazine, pyrimidine, quinoline, 1-methylimidazole, 4,4′-bipyridyl, 4-methyl-4,4 - Nitrogen-containing heterocyclic compounds such as bipyridyl and the like.

The amount of the amine compound that can be used in these reactions is 0.1 to 20 molar equivalents, preferably 0.5 to 10 molar equivalents, based on 1 mol of the halogen atom of the hyperbranched polymer having a halogen atom at the molecular end. Preferably, it is 1 to 5 molar equivalents.

The reaction between the hyperbranched polymer having a halogen atom at the molecular end and the amine compound can be carried out in water or an organic solvent in the presence or absence of a base. The solvent to be used is preferably a solvent capable of dissolving a hyperbranched polymer having a halogen atom at the molecular end and an amine compound. Furthermore, a hyperbranched polymer having a halogen atom at the molecular end and an amine compound can be dissolved, but a solvent that does not dissolve the hyperbranched polymer having an ammonium group at the molecular end is more preferable because it can be easily isolated.
Solvents that can be used in this reaction are not particularly limited as long as they do not significantly inhibit the progress of this reaction. Water; alcohols such as isopropanol; organic acids such as acetic acid; benzene, toluene, xylene, ethylbenzene, 1,2-di- Aromatic hydrocarbons such as chlorobenzene; ethers such as tetrahydrofuran (THF) and diethyl ether; ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK) and cyclohexanone; chloroform, dichloromethane, 1,2-dichloroethane Halides such as n-hexane, n-heptane, cyclohexane, etc .; N, N-dimethylformamide (DMF), N, N-dimethylacetamide, N-methyl-2-pyrrolidone (NMP), etc. The amides can be used. These solvents may be used alone or in combination of two or more. The amount used is 0.2 to 1,000 times, preferably 1 to 500 times, more preferably 5 to 100 times, most preferably the mass of the hyperbranched polymer having a halogen atom at the molecular end. It is preferable to use a solvent having a mass of 5 to 50 times.

Suitable bases generally include alkali metal hydroxides and alkaline earth metal hydroxides (eg sodium hydroxide, potassium hydroxide, calcium hydroxide), alkali metal oxides and alkaline earth metal oxides (eg lithium oxide). Calcium oxide), alkali metal hydrides and alkaline earth metal hydrides (eg sodium hydride, potassium hydride, calcium hydride), alkali metal amides (eg sodium amide), alkali metal carbonates and alkaline earth metal carbonates Inorganic compounds such as salts (eg lithium carbonate, sodium carbonate, potassium carbonate, calcium carbonate), alkali metal bicarbonates (eg sodium bicarbonate), and alkali metal alkyls, alkylmagnesium halides, alkali metal alkoxides, alkaline earth metals Alkoki De, organometallic compounds such as dimethoxy magnesium was used. Particularly preferred are potassium carbonate and sodium carbonate. The amount used is 0.2 to 10 molar equivalents, preferably 0.5 to 10 molar equivalents, most preferably 1 to 5 molar equivalents per mole of halogen atoms of the hyperbranched polymer having a halogen atom at the molecular end. It is preferable to use the base.

In this reaction, it is preferable to sufficiently remove oxygen in the reaction system before starting the reaction, and the inside of the system may be replaced with an inert gas such as nitrogen or argon. The reaction conditions are appropriately selected from a reaction time of 0.01 to 100 hours and a reaction temperature of 0 to 300 ° C. Preferably, the reaction time is 0.1 to 72 hours, and the reaction temperature is 20 to 150 ° C.

When a tertiary amine is used, a hyperbranched polymer represented by the formula [1] can be obtained regardless of the presence / absence of a base.
When a hyperbranched polymer having a halogen atom at the molecular end is reacted with a primary amine or secondary amine compound in the absence of a base, the terminal secondary amine and tertiary tertiary of the corresponding hyperbranched polymer are respectively reacted. A hyperbranched polymer having ammonium groups terminated with protonated primary amines is obtained. In addition, even when the reaction is performed using a base, the terminal secondary amine of the corresponding hyperbranched polymer can be obtained by mixing with an aqueous solution of an acid such as hydrogen chloride, hydrogen bromide, or hydrogen iodide in an organic solvent. And a hyperbranched polymer having an ammonium group terminated with a tertiary amine protonated.

The hyperbranched polymer has a weight average molecular weight Mw measured in terms of polystyrene by gel permeation chromatography of 1,000 to 5,000,000, preferably 1,000 to 500,000, more preferably 2 3,000 to 200,000, most preferably 3,000 to 100,000. Further, the dispersity Mw (weight average molecular weight) / Mn (number average molecular weight) is 1.0 to 7.0, preferably 1.1 to 6.0, and more preferably 1.2 to 5. 0.

<(C) Metal fine particles>
The metal fine particles used in the resin composition used in the present invention are not particularly limited, and the metal species are iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), palladium (Pd), silver. (Ag), tin (Sn), platinum (Pt), and gold (Au) may be mentioned, and one kind of these metals or two or more kinds of alloys may be used. Among these, preferable metal fine particles include palladium fine particles. The metal oxide may be used as the metal fine particles.

The metal fine particles can be obtained by reducing metal ions by, for example, a method of irradiating an aqueous solution of a metal salt with a high-pressure mercury lamp or a method of adding a compound having a reducing action (so-called reducing agent) to the aqueous solution. For example, an aqueous solution of a metal salt is added to a solution in which the hyperbranched polymer is dissolved and irradiated with ultraviolet light, or an aqueous solution of a metal salt and a reducing agent are added to the solution to reduce metal ions. Thus, a resin composition containing the hyperbranched polymer and the metal fine particles and other components described later can be prepared while forming a composite of the hyperbranched polymer and the metal fine particles.

Examples of the metal salt include chloroauric acid, silver nitrate, copper sulfate, copper nitrate, copper acetate, tin chloride, platinum chloride, chloroplatinic acid, Pt (dba) ₂ [dba = dibenzylideneacetone], Pt (cod) ₂ [cod = 1,5-cyclooctadiene], Pt (CH ₃ ) ₂ (cod), palladium chloride, palladium acetate (Pd (OC (═O) CH ₃ ) ₂ ), palladium nitrate, Pd ₂ (dba) _{_{3 · CHCl 3, Pd (dba}} ) 2, rhodium chloride, rhodium acetate, ruthenium chloride, ruthenium acetate, Ru (cod) (cot) [cot = cyclooctatriene], iridium chloride, iridium acetate, Ni _{(cod) 2,} etc. Is mentioned.
The reducing agent is not particularly limited, and various reducing agents can be used, and it is preferable to select the reducing agent according to the metal species to be contained in the resin composition (that is, nanofiber) obtained later. . Examples of the reducing agent that can be used include metal borohydrides such as sodium borohydride and potassium borohydride; lithium aluminum hydride, potassium aluminum hydride, cesium aluminum hydride, aluminum beryllium hydride, hydrogenation Aluminum hydride salts such as aluminum magnesium and calcium aluminum hydride; hydrazine compounds; citric acid and salts thereof; succinic acid and salts thereof; ascorbic acid and salts thereof; primary or secondary such as methanol, ethanol, isopropanol and polyol Tertiary alcohols; tertiary amines such as trimethylamine, triethylamine, diisopropylethylamine, diethylmethylamine, tetramethylethylenediamine [TMEDA], ethylenediaminetetraacetic acid [EDTA]; Roxylamine; tri-n-propylphosphine, tri-n-butylphosphine, tricyclohexylphosphine, tribenzylphosphine, triphenylphosphine, triethoxyphosphine, 1,2-bis (diphenylphosphino) ethane [DPPE], 1,3 -Bis (diphenylphosphino) propane [DPPP], 1,1'-bis (diphenylphosphino) ferrocene [DPPF], 2,2'-bis (diphenylphosphino) -1,1'-binaphthyl [BINAP], etc. And phosphines.

The average particle size of the metal fine particles is preferably 1 to 100 nm. The reason is that when the average particle diameter of the metal fine particles exceeds 100 nm, the surface area decreases and the catalytic activity decreases. The average particle size is more preferably 75 nm or less, and particularly preferably 1 to 30 nm.

In the resin composition used in the present invention, the amount of (b) hyperbranched polymer added to (c) metal fine particles is preferably 50 to 2,000 parts by mass with respect to 100 parts by mass of (c) metal fine particles. When the amount is less than 50 parts by mass, the dispersibility of the metal fine particles is insufficient, and when the amount exceeds 2,000 parts by mass, the organic matter content increases, and problems such as physical properties tend to occur. More preferably, it is 100 to 1,000 parts by mass.

[Complex]
In the resin composition used in the present invention, it is preferable that the hyperbranched polymer and the metal fine particles form a composite.
Here, the composite is a particle that is in contact with or close to the metal fine particles due to the action of the ammonium group at the end of the hyperbranched polymer to form a particulate form. It is expressed as a composite having a structure in which the ammonium group of the polymer is attached or coordinated to the metal fine particles.
Therefore, in the “composite” in the present invention, not only the metal fine particles and the hyperbranched polymer are combined to form one composite as described above, but also the metal fine particles and the hyperbranched polymer have bonding portions. Those that are present independently without being formed may also be included.

The hyperbranched polymer and metal fine particle composite may be formed in advance by combining the hyperbranched polymer and metal fine particles, or may be performed simultaneously with the preparation of the resin composition used in the production method of the present invention. . As the method, after synthesizing metal fine particles stabilized to some extent with a lower ammonium ligand, the ligand is exchanged with a hyperbranched polymer, or by directly reducing metal ions in a hyperbranched polymer solution. There are methods of forming a complex.

In the ligand exchange method, the metal fine particles stabilized to some extent by the lower ammonium ligand used as a raw material can be synthesized by the method described in Journal of Organometallic Chemistry 1996, 520, 143-162 and the like. A hyperbranched polymer is dissolved in the resulting reaction mixture solution of metal fine particles, and the target metal fine particle composite can be obtained by room temperature (approximately 25 ° C.) or heating and stirring.
The solvent to be used is not particularly limited as long as it is a solvent capable of dissolving the metal fine particles and the hyperbranched polymer at a required concentration or higher. Specifically, alcohols such as ethanol, n-propanol, and isopropanol; methylene chloride, Halogenated hydrocarbons such as chloroform; cyclic ethers such as tetrahydrofuran (THF), 2-methyltetrahydrofuran, tetrahydropyran; nitriles such as acetonitrile and butyronitrile; and mixtures of these solvents, preferably tetrahydrofuran. Is mentioned.
The temperature at which the metal fine particle reaction mixture and the hyperbranched polymer are mixed is usually in the range of 0 ° C. to the boiling point of the solvent, preferably in the range of room temperature (approximately 25 ° C.) to 60 ° C.
In the ligand exchange method, the metal fine particles can be stabilized to some extent in advance by using a phosphine dispersant (phosphine ligand) in addition to the amine dispersant (lower ammonium ligand).

As a direct reduction method, a metal ion and a hyperbranched polymer are dissolved in a solvent and reduced with a primary or secondary alcohol such as methanol, ethanol, isopropanol, polyol, etc. Obtainable.
As the metal ion source used here, the above-mentioned metal salts can be used.
The solvent to be used is not particularly limited as long as it can dissolve the metal ion and the hyperbranched polymer at a required concentration or more. Specifically, alcohols such as methanol, ethanol, n-propanol, and isopropanol; methylene chloride Halogenated hydrocarbons such as chloroform; cyclic ethers such as tetrahydrofuran (THF), 2-methyltetrahydrofuran, tetrahydropyran; nitriles such as acetonitrile and butyronitrile; N, N-dimethylformamide (DMF), N-methyl- Amides such as 2-pyrrolidone (NMP); Sulfoxides such as dimethyl sulfoxide and the like, and mixtures of these solvents are preferable, and alcohols, halogenated hydrocarbons, and cyclic ethers are preferable, and more preferable. The Etano Le, isopropanol, chloroform, and the like and tetrahydrofuran.
The temperature of the reduction reaction can usually be in the range of 0 ° C. to the boiling point of the solvent, preferably in the range of room temperature (approximately 25 ° C.) to 60 ° C.

As another direct reduction method, a target metal fine particle composite can be obtained by dissolving a metal ion and a hyperbranched polymer in a solvent and reacting them in a hydrogen gas atmosphere.
As a metal ion source used here, the above-mentioned metal salt, hexacarbonyl chromium [Cr (CO) ₆ ], pentacarbonyl iron [Fe (CO) ₅ ], octacarbonyl dicobalt [Co ₂ (CO) ₈ ]. A metal carbonyl complex such as tetracarbonyl nickel [Ni (CO) ₄ ] can be used. In addition, zero-valent metal complexes such as metal olefin complexes, metal phosphine complexes, and metal nitrogen complexes can also be used.
The solvent to be used is not particularly limited as long as it can dissolve the metal ion and the hyperbranched polymer at a required concentration or more. Specifically, alcohols such as ethanol and n-propanol; methylene chloride, chloroform and the like Halogenated hydrocarbons; cyclic ethers such as tetrahydrofuran, 2-methyltetrahydrofuran and tetrahydropyran; nitriles such as acetonitrile and butyronitrile; and a mixture of these solvents, preferably tetrahydrofuran.
The temperature at which the metal ions and the hyperbranched polymer are mixed can usually be in the range of 0 ° C. to the boiling point of the solvent.

Further, as a direct reduction method, a target metal fine particle composite can be obtained by dissolving a metal ion and a hyperbranched polymer in a solvent and causing a thermal decomposition reaction.
As the metal ion source used here, the above metal salts, metal carbonyl complexes, other zero-valent metal complexes, and metal oxides such as silver oxide can be used.
The solvent to be used is not particularly limited as long as it can dissolve the metal ion and the hyperbranched polymer at a required concentration or more. Specifically, alcohols such as methanol, ethanol, n-propanol, isopropanol, and ethylene glycol are used. Halogenated hydrocarbons such as methylene chloride and chloroform; cyclic ethers such as tetrahydrofuran (THF), 2-methyltetrahydrofuran and tetrahydropyran; nitriles such as acetonitrile and butyronitrile; aromatic hydrocarbons such as benzene and toluene; And a mixture of these solvents, preferably toluene.
The temperature at which the metal ions and the hyperbranched polymer are mixed usually ranges from 0 ° C. to the boiling point of the solvent, preferably around the boiling point of the solvent, for example, 110 ° C. (heated reflux) in the case of toluene.

The hyperbranched polymer / metal fine particle composite thus obtained can be in the form of a solid such as a powder through a purification treatment such as reprecipitation.

[Resin composition]
In the resin composition used as a spinning material in the present invention, the blending amount of (b) the hyperbranched polymer and (c) the metal fine particles with respect to the thermoplastic resin is a composite formed from the hyperbranched polymer and the metal fine particles. The amount is preferably 0.1 to 20 parts by weight, particularly 1 to 10 parts by weight, based on 100 parts by weight of the thermoplastic resin.

In the resin composition according to the present invention, additives generally added together with the thermoplastic resin, for example, heat stabilizer, light stabilizer, antioxidant, ultraviolet absorber, lubricant, mold release agent, antistatic agent, melting Elastic modifiers, processing aids, crosslinking agents, reinforcing agents, flame retardants, antifoaming agents, dispersants, light diffusing agents, pigments, dyes, fluorescent dyes, and the like may be used in combination.

[Production Method of Conductive Nanofiber]
<Spinning process>
The spinning step in the method for producing a conductive nanofiber of the present invention is performed according to an electrospinning method using the resin composition containing (a) thermoplastic resin, (b) hyperbranched polymer, and (c) metal fine particles as a spinning material. This is a process for producing nanofibers. In practice, the composition is dissolved or dispersed in a solvent to form a varnish, which is electrospun to produce nanofibers.

The solvent used for the electrostatic spinning may be any solvent that can dissolve and disperse the thermoplastic resin, the hyperbranched polymer, and the metal fine particles. For example, acetone, ethyl methyl ketone (MEK), isobutyl methyl ketone (MIBK), chloroform, tetrahydrofuran (THF), 1,4-dioxane, toluene, xylene, N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP) ), Cyclohexanone, propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether, ethyl lactate, diethylene glycol monoethyl ether, butyl cello Lube, ethanol, hexafluoroisopropanol (HFIP), .gamma.-butyrolactone, formic acid, acetic acid, trifluoroacetic acid and the like. These solvents may be used alone, or two or more kinds of solvents may be mixed.
The concentration of the thermoplastic resin, the hyperbranched polymer, and the metal microparticles is arbitrary with respect to the total mass (total mass) of the thermoplastic resin, the hyperbranched polymer, and the metal microparticles and the solvent. (Also referred to as solid content concentration) is 1 to 50% by mass, preferably 10 to 40% by mass, and more preferably 20 to 30% by mass.

A commercially available electrospinning apparatus can be used for the electrospinning.
The spinning conditions are appropriately selected. For example, nozzle length: 3 to 5 cm, spinning distance (electrode-collector distance): 5 to 30 cm, spinning amount: 0.1 to 5.0 mL / hour, applied voltage between electrodes : 5 to 40 kV.

The nanofibers obtained as described above preferably have an average diameter of 50 to 2,000 nm, more preferably 100 to 1,000 nm.

<Plating process>
The plating step in the method for producing conductive nanofibers of the present invention is a step of electroless plating treatment of the nanofibers produced in the above-described <spinning step>.
The nanofibers produced by the spinning process described above are in a state where the hyperbranched polymer and metal fine particles (composites formed from these) are present on the fiber surface (interface). For this reason, the nanofiber obtained by the electrospinning method can be used for the electroless plating process as it is, without requiring the plating pretreatment which consists of each process of etching, conditioning, catalyzing, and acceleration.
The electroless plating treatment (process) is not particularly limited, and can be performed by any of the generally known electroless plating treatments. A method of immersing nanofibers obtained in the spinning process in the plating solution (bath) is common.

The electroless plating solution mainly contains a metal ion (metal salt), a complexing agent, and a reducing agent, and a pH adjuster, a pH buffering agent, a reaction accelerator (second complexing agent) according to other uses. , Stabilizers, surfactants (use for imparting gloss to the plating film, use for improving wettability of the surface to be treated, etc.) and the like are appropriately included.
Examples of the metal used in the metal plating film formed by electroless plating include iron, cobalt, nickel, copper, palladium, silver, tin, platinum, gold, and alloys thereof, and are appropriately selected according to the purpose. Is done.
The complexing agent and the reducing agent may be appropriately selected according to the metal ion.
The electroless plating solution may be a commercially available plating solution. For example, an electroless nickel plating chemical (Melplate (registered trademark) NI series) manufactured by Meltex Co., Ltd., an electroless copper plating chemical (Melplate ( (Registered trademark) CU series); Electroless nickel plating solution (ICP Nicolon (registered trademark) series) manufactured by Okuno Pharmaceutical Industry Co., Ltd., Electroless copper plating solution (OPC-700 Electroless copper MK, ATS Addcopper IW) ), Electroless tin plating solution (Substar SN-5), electroless gold plating solution (flash gold 330, self gold OTK-IT); electroless palladium plating solution (pallet II) manufactured by Kojima Chemical Co., Ltd. Electroless gold plating solution (Dip G series, NC gold series); Electroless silver plating solution manufactured by Sasaki Chemical Co., Ltd. ); Electroless nickel plating solution (Schumer (registered trademark) series, Schumer (registered trademark) crab black (registered trademark) series), Electroless palladium plating solution (S-KPD) manufactured by Nippon Kanisen Co., Ltd .; Dow Chemical Company Electroless copper plating solution (Cuposit (registered trademark) Coppermix series, Circuposit (registered trademark) series), Electroless palladium plating solution (Paramars (registered trademark) series), Electroless nickel plating solution (Duraposit ( (Registered trademark) series), electroless gold plating solution (Aurolectroles (registered trademark) series), electroless tin plating solution (Tinposito (registered trademark) series); electroless copper plating solution manufactured by Uemura Kogyo Co., Ltd. ( Surcup (registered trademark) ELC-SP, PSY, PCY, PGT, PSR, P A); Atotech Japan Co., Ltd. electroless copper plating solution (Printgant (R) PV) and the like can be suitably used.

The electroless plating process adjusts the temperature, pH, immersion time, metal ion concentration, presence / absence of stirring, stirring speed, presence / absence of supply of air / oxygen, supply speed, etc. And the film thickness can be controlled.
The thickness of the plating film to be obtained is not particularly limited, but can generally be about 10 to 500 nm, for example, 30 to 300 nm.

Thus, the electroconductive nanofiber of this invention produced can have an aggregate shape (for example, mat shape).
Further, the conductive nanofiber aggregate preferably has a volume resistance value of 1 × 10 ⁴ Ω · cm or less, and desirably 1 × 10 ² Ω · cm or less.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated more concretely, this invention is not limited to the following Example.
In the examples, the apparatus and conditions used for sample preparation and physical property analysis are as follows.

(1) GPC (gel permeation chromatography)
Equipment: HLC-8220GPC manufactured by Tosoh Corporation
Column: Shodex (registered trademark) KF-804L + KF-803L manufactured by Showa Denko KK
Column temperature: 40 ° C
Solvent: Tetrahydrofuran Detector: UV (254 nm), RI
(2) ¹ H NMR spectrum apparatus: JNM-L400 manufactured by JEOL Ltd.
Solvent: CDCl ₃
Internal standard: Tetramethylsilane (0.00ppm)
(3) ¹³ C NMR spectrum apparatus: JNM-ECA700 manufactured by JEOL Ltd.
Solvent: CDCl ₃
Relaxing reagent: trisacetylacetonatochrome (Cr (acac) ₃ )
Standard: CDCl ₃ (77.0 ppm)
(4) ICP emission analysis (inductively coupled plasma emission analysis)
Equipment: ICPM-8500, manufactured by Shimadzu Corporation
(5) TEM (Transmission Electron Microscope) image device: H-8000 manufactured by Hitachi High-Technologies Corporation
(6) Electrospinning infusion pump (syringe pump): (Yes) FP-1000 manufactured by Melquest
High voltage power supply: HR-40R0.75 manufactured by Matsusada Precision Co., Ltd.
(7) SEM (Scanning Electron Microscope) Image Device: 3D Real Surface View Microscope VE-9800 manufactured by Keyence Corporation
(8) Volume resistance measurement device: Loresta (registered trademark) AX MCP-T370 manufactured by Mitsubishi Chemical Analytech Co., Ltd.

The abbreviations used are as follows.
HPS: Hyperbranched polystyrene [Hypertech (registered trademark) HPS-200 manufactured by Nissan Chemical Industries, Ltd.]
IPA: 2-propanol IPE: diisopropyl ether PVDF: polyvinylidene fluoride [manufactured by Aldrich, product number: 427152, Mw (GPC): 180,000, Mn: 71,000]
PVDF / HFP: Vinylidene fluoride-hexafluoropropylene copolymer [manufactured by Aldrich, product number: 427160, Mw (GPC): 400,000, Mn: 130,000]
PU: Polyurethane [Elastolan (registered trademark) ET385, Mw (GPC): 146,000, manufactured by BASF Japan Ltd.]
DMAc: N, N-dimethylacetamide DMF: N, N-dimethylformamide THF: tetrahydrofuran

[Production Example 1] Production of HPS-Cl

In a 500 mL reaction flask, 27 g of sulfuryl chloride [manufactured by Kishida Chemical Co., Ltd.] and 50 g of chloroform were charged and stirred to dissolve uniformly. The solution was cooled to 0 ° C. under a nitrogen stream.
In another 300 mL reaction flask, 15 g of hyperbranched polymer HPS having a dithiocarbamate group at the molecular end and 150 g of chloroform were charged and stirred under nitrogen flow until uniform.
From the 300 mL reaction flask charged with the HPS / chloroform solution in a sulfuryl chloride / chloroform solution cooled to 0 ° C. in a nitrogen stream, the solution was cooled to the temperature of the reaction solution. Was added over 60 minutes so that the temperature became -5 to 5 ° C. After completion of the addition, the reaction solution was stirred for 6 hours while maintaining the temperature at -5 to 5 ° C.
Further, a solution prepared by dissolving 16 g of cyclohexene [manufactured by Tokyo Chemical Industry Co., Ltd.] in 50 g of chloroform was added to this reaction solution so that the temperature of the reaction solution became −5 to 5 ° C. After completion of the addition, this reaction solution was added to 1,200 g of IPA to precipitate a polymer. The white powder obtained by filtering this precipitate was dissolved in 100 g of chloroform and added to 500 g of IPA to reprecipitate the polymer. The precipitate was filtered under reduced pressure and vacuum dried to obtain 8.5 g of hyperbranched polymer (HPS-Cl) having a chlorine atom at the molecular end as a white powder (yield 99%).
The ¹ H NMR spectrum of the obtained HPS-Cl is shown in FIG. Since the peak (4.0 ppm, 3.7 ppm) derived from the dithiocarbamate group disappeared, it was confirmed that the obtained HPS-Cl had almost all the dithiocarbamate groups at the HPS molecule terminals substituted with chlorine atoms. It became clear. Moreover, the weight average molecular weight Mw measured by polystyrene conversion by GPC of the obtained HPS-Cl was 14,000, and the dispersity Mw / Mn was 2.9.

[Production Example 2] Production of HPS-N (Me) ₂ OctCl

A 300 mL reaction flask equipped with a condenser was charged with 4.6 g (30 mmol) of HPS-Cl produced in Production Example 1 and 15 g of chloroform, and stirred until uniform. To this solution, a solution of 5.0 g (31.5 mmol) of dimethyloctylamine [Farmin (registered trademark) DM0898 manufactured by Kao Corporation] dissolved in 7.5 g of chloroform was added, and 7.5 g of IPA was further added. The mixture was stirred at 65 ° C. for 40 hours under a nitrogen atmosphere.
After cooling to a liquid temperature of 30 ° C., the solvent was distilled off. The obtained residue was dissolved in 60 g of chloroform, and this solution was added to 290 g of IPE for purification by reprecipitation. The precipitated polymer was filtered under reduced pressure and vacuum dried at 50 ° C. to obtain 9.3 g of a hyperbranched polymer (HPS-N (Me) ₂ OctCl) having a dimethyloctylammonium group at the molecular end as a white powder.
The ¹³ C NMR spectrum of the resulting HPS-N (Me) ₂ OctCl is shown in FIG. The HPS-N (Me) ₂ OctCl obtained from the peak of the benzene ring and the peak of the methyl group at the end of the octyl group shows that the chlorine atom at the end of the HPS-Cl molecule is almost quantitatively substituted with an ammonium group. Became clear. The weight average molecular weight Mw of HPS-N (Me) ₂ OctCl calculated from Mw (14,000) of HPS-Cl and ammonium group introduction rate (100%) was 28,000.

[Production Example 3] Production of Pd [HPS-N (Me) ₂ OctCl] A 300 mL reaction flask equipped with a condenser was charged with 2.1 g of palladium acetate [manufactured by Kawaken Fine Chemical Co., Ltd.] and 20 g of chloroform. Stir until. To this solution, a solution prepared by dissolving 9.0 g of HPS-N (Me) ₂ OctCl prepared in Production Example 2 in 135 g of chloroform was added using a dropping funnel. The dropping funnel was washed into the reaction flask using 45 g of ethanol. The mixture was stirred at 60 ° C. for 8 hours.
After cooling to a liquid temperature of 30 ° C., the reaction mixture was added to 2,000 g of IPE at 0 ° C. and purified by reprecipitation. The precipitated polymer was filtered under reduced pressure and vacuum dried at 60 ° C., and 9.8 g of a complex of a hyperbranched polymer and Pd particles having an ammonium group at the molecular end (Pd [HPS-N (Me) ₂ OctCl]) was blackened. Obtained as a powder.
From the results of ICP emission analysis, the Pd content of the obtained Pd [HPS-N (Me) ₂ OctCl] was 10% by mass. Further, from the TEM (transmission electron microscope) image, the Pd particle diameter was about 2 to 4 nm.

[Production Example 4] Production of HPS-NOct ₃ Cl

A 100 mL reaction flask equipped with a reflux tower was charged with 4.6 g (30 mmol) of HPS-Cl produced in Production Example 1, 10.6 g (30 mmol) of trioctylamine [manufactured by Junsei Chemical Co., Ltd.] and 45 g of chloroform, and nitrogen was added. Replaced. The mixture was heated to reflux with stirring for 48 hours.
After cooling to a liquid temperature of 30 ° C., the solvent was distilled off. The obtained residue was dissolved in 150 g of chloroform and cooled to 0 ° C. This solution was added to 3,000 g of IPE at 0 ° C. for reprecipitation purification. The precipitated polymer was filtered under reduced pressure and vacuum dried at 40 ° C. to obtain 9.6 g of a hyperbranched polymer (HPS-NOct ₃ Cl) having a trioctylammonium group at the molecular end as a pale yellow powder.
The ¹³ C NMR spectrum of the resulting HPS-NOct ₃ Cl is shown in FIG. From the peak of the methylene group to which the chlorine atom is bonded and the peak of the methylene group to which the ammonium group is bonded, the obtained HPS-NOct ₃ Cl has 71% of the chlorine atom at the end of the HPS-Cl molecule replaced with the ammonium group. Became clear. The weight average molecular weight Mw of HPS-NOct ₃ Cl calculated from Mw (14,000) of HPS-Cl and ammonium group introduction rate (71%) was 37,000.

[Production Example 5] Production of Pd [HPS-NOct ₃ Cl] Into a 1 L two-necked flask, 4.3 g of palladium acetate [manufactured by Kawaken Fine Chemical Co., Ltd.] and 200 g of chloroform were charged and stirred until uniform. To this solution, a solution obtained by dissolving 18.0 g of HPS-NOct ₃ Cl produced according to Production Example 4 in 200 g of chloroform was added using a dropping funnel. The dropping funnel was washed into the reaction flask using 100 g of ethanol. The mixture was stirred at 60 ° C. for 17 hours.
After cooling to a liquid temperature of 30 ° C., the solvent was distilled off. The obtained residue was dissolved in 300 g of THF and cooled to 0 ° C. This solution was added to 6,000 g of IPE at 0 ° C. for reprecipitation purification. The precipitated polymer was filtered under reduced pressure and vacuum dried at 60 ° C. to obtain 19.9 g of a complex of a hyperbranched polymer having an ammonium group at the molecular end and Pd particles (Pd [HPS-NOct ₃ Cl]) as a black powder. It was.
From the result of ICP emission analysis, the Pd content of the obtained Pd [HPS-NOct ₃ Cl] was 11% by mass. Further, from the TEM (transmission electron microscope) image, the Pd particle diameter was about 2 to 4 nm.

[Reference Example 1] Preparation of electroless copper plating solution A In a 1 L flask, Melplate (registered trademark, hereinafter the same) CU-390A [Meltex Co., Ltd.] 80 mL, Melplate CU-390B [Meltex Co., Ltd. )] 80 mL and Melplate CU-390C [Meltex Co., Ltd.] 20 mL were charged, and pure water was added to make the total volume of the solution 1 L. To this solution, 0.7 g of Adeka (registered trademark) Pluronic L-34 [manufactured by ADEKA Co., Ltd.] was added as a surfactant to obtain an electroless copper plating solution A (Cu-A).

[Reference Example 2] Preparation of electroless copper plating solution B In a 1 L flask, Cuposit (registered trademark, the same applies below) Copper Mix 328A (Dow Chemical Co.) 125 mL, Cuposit Copper Mix 328L (Dow Chemical Co.) 125 mL And 15 mL of Cuposit Copper Mix 328C [manufactured by Dow Chemical Co., Ltd.] were added, and pure water was added to make the total amount of the solution 1 L. To this solution, 0.7 g of Adeka (registered trademark) Pluronic L-34 [manufactured by ADEKA Co., Ltd.] was added as a surfactant to obtain an electroless copper plating solution B (Cu-B).

[Reference Example 3] Preparation of electroless copper plating solution C In a 500 mL flask, ion-exchanged water 200 mL, Sulcup (registered trademark) PSY-1A [manufactured by Uemura Kogyo Co., Ltd.] 25 mL, Sulcup (registered trademark) PSY-1B [ Uemura Kogyo Co., Ltd.] 10 mL and 18.5 mass% formaldehyde aqueous solution 0.5 mL were charged, and ion exchange water was further added to make the total amount of the solution 500 mL. To this solution, 0.05 g of Adeka (registered trademark) Pluronic L-34 [manufactured by ADEKA Co., Ltd.] was added as a surfactant to obtain an electroless copper plating solution C (Cu-C).

[Reference Example 4] Preparation of electroless nickel plating solution A In a 1 L flask, Melplate (registered trademark, hereinafter the same) NI-6522LF1 [Meltex Co., Ltd.] 50 mL, Melplate NI-6522LF2 [Meltex Co., Ltd. )] 150 mL and Melplate NI-6522LF additive [Meltex Co., Ltd.] 5 mL were charged, and pure water was added to make the total volume of the solution 1 L. This solution was designated as an electroless nickel plating solution A (Ni-A).

[Reference Example 5] Preparation of electroless nickel plating solution B To a 200 mL flask, 70 mL of Kanisen (registered trademark) Blue Schumer [manufactured by Nippon Kanisen Co., Ltd.] was added, and pure water was added to make the total amount of the solution 100 mL. . To this solution, 0.01 g of benzalkonium chloride [manufactured by Tokyo Chemical Industry Co., Ltd.] was added as a surfactant to obtain an electroless nickel plating solution B (Ni-B).

[Reference Example 6] Preparation of electroless tin plating solution A Tinposit (registered trademark) LT-34C [manufactured by Dow Chemical Co., Ltd.] was used as electroless tin plating solution A (Sn-A).

[Example 1]
100 parts by mass of PVDF, 5 parts by mass of Pd [HPS-N (Me) ₂ OctCl] produced according to Production Example 3 (0.5 parts by mass as Pd), and 300 parts by mass of a DMF / acetone mixed liquid (mass ratio 9: 1) Were uniformly mixed to prepare a resin composition (spun material).
This composition was spun under the conditions shown in Table 1 using an electrospinning apparatus to produce an assembly of nanofibers on the mat (hereinafter referred to as nanofiber mat). The obtained nanofiber mat was observed with an SEM, and the nanofiber diameter (average diameter) was calculated. The nanofiber diameter was determined by measuring the diameters of 100 nanofibers randomly selected from five different SEM images, and taking the average value. The results are shown in Table 1.
Next, this nanofiber mat was immersed in the plating solution shown in Table 1 for the time shown in Table 1. Thereafter, the nanofiber mat taken out was washed with water and air-dried. The nanofiber diameter of the obtained nanofiber mat subjected to electroless plating was calculated in the same manner as described above. Moreover, the volume resistance value of the nanofiber mat was measured. The results are also shown in Table 1. Further, FIG. 4 shows an SEM image of the obtained nanofiber mat subjected to the electroless plating treatment.

[Example 2]
100 parts by mass of PVDF, 4.5 parts by mass of Pd [HPS-NOct ₃ Cl] produced according to Production Example 5 (0.5 parts by mass as Pd), and 300 parts by mass of a DMAc / acetone mixture (mass ratio 7: 3) The resin composition was prepared by mixing uniformly.
This composition was used and evaluated in the same manner as in Example 1 except that the plating solution shown in Table 1 was used. The results are also shown in Table 1.

[Example 3]
The same operation as in Example 2 was performed except that the plating solution was changed. The results are also shown in Table 1.

[Example 4]
100 parts by mass of PU, 5 parts by mass of Pd [HPS-N (Me) ₂ OctCl] produced according to Production Example 3 (0.5 parts by mass as Pd), and 614 parts by mass of DMF were uniformly mixed to prepare a resin composition. .
This composition was used and evaluated in the same manner as in Example 1 except that the plating solution shown in Table 1 was used. The results are also shown in Table 1.

[Example 5]
100 parts by mass of PU, 4.5 parts by mass of Pd [HPS-NOct ₃ Cl] produced according to Production Example 5 (0.5 parts by mass as Pd), and 614 parts by mass of DMF were uniformly mixed to prepare a resin composition.
This composition was used and evaluated in the same manner as in Example 1 except that the plating solution shown in Table 1 was used. The results are also shown in Table 1.

[Example 6]
100 parts by mass of PVDF / HFP, 5 parts by mass of Pd [HPS-N (Me) ₂ OctCl] produced according to Production Example 3 (0.5 parts by mass as Pd), and 400 parts by mass of DMF were uniformly mixed to obtain a resin composition. Prepared.
This composition was used and evaluated in the same manner as in Example 1 except that the plating solution shown in Table 1 was used. The results are also shown in Table 1.

[Example 7]
The nanofiber mat obtained in Example 6 was immersed in the electroless tin plating solution A (Sn-A) prepared in Reference Example 5 at 20 ° C. for 5 minutes. Thereafter, the nanofiber mat taken out was washed with water and air-dried. The nanofiber diameter of the obtained electroless plating (substitution type) treated nanofiber mat was calculated in the same manner as described above. Moreover, the volume resistance value of the nanofiber mat was measured. The results are also shown in Table 1. Moreover, the SEM image of the obtained nanofiber mat subjected to electroless plating is shown in FIG.

[Comparative Example 1]
100 parts by mass of PVDF, 0.83 parts by mass of palladium chloride (0.5 parts by mass as Pd), and 300 parts by mass of DMF were uniformly mixed to prepare a resin composition.
When the same operation as in Example 1 was carried out except that this composition was used, no metal plating film was formed.

As shown in Table 1, in Examples 1 to 7, a conductive material having a low volume resistance of 1 × 10 ⁴ Ω · cm or less by a simple method without being restricted by the type of plating metal or the type of plating solution. An aggregate of nanofibers (nanofiber mat) could be obtained.
On the other hand, in Comparative Example 1 using a spinning material in which palladium chloride was blended with PVDF, copper plating was not performed, and conductive nanofibers could not be obtained.

Claims

A resin composition comprising (a) a thermoplastic resin, (b) a hyperbranched polymer having an ammonium group at the molecular end and a weight average molecular weight of 1,000 to 5,000,000, and (c) metal fine particles. As a spinning material, a spinning process for producing nanofibers according to an electrospinning method, and a plating process for electroless plating of the nanofibers produced in the above process,
The manufacturing method of electroconductive nanofiber characterized by including these.
The manufacturing method according to claim 1, wherein the (c) metal fine particles are attached with the ammonium group of the (b) hyperbranched polymer to form a composite.
The manufacturing method of Claim 1 or Claim 2 whose said (b) hyperbranched polymer is a hyperbranched polymer represented by Formula [1].

(In the formula, each R 1 independently represents a hydrogen atom or a methyl group, and R 2 to R 4 each independently represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. , An arylalkyl group having 7 to 20 carbon atoms or — (CH 2 CH 2 O) m R 5 (wherein R 5 represents a hydrogen atom or a methyl group, and m represents an integer of 2 to 100). (The alkyl group and arylalkyl group may be substituted with an alkoxy group, a hydroxy group, an ammonium group, a carboxyl group, or a cyano group), or two groups of R 2 to R 4 may be bonded together. Represents a linear, branched or cyclic alkylene group, or R 2 to R 4 may form a ring together with the nitrogen atom to which they are bonded, and X − represents an anion. Where n is a repetition A number of by unit structure, an integer of 5 to 100,000, A 1 represents a structure represented by Formula [2].)

(In the formula, A 2 represents a linear, branched or cyclic alkylene group having 1 to 30 carbon atoms which may contain an ether bond or an ester bond, and Y 1 to Y 4 are each independently hydrogen. And represents an atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a nitro group, a hydroxy group, an amino group, a carboxyl group, or a cyano group.
The manufacturing method of Claim 3 whose said (b) hyperbranched polymer is a hyperbranched polymer represented by Formula [3].

(Wherein R 1 , R 2 to R 4 and n represent the same meaning as described above.)
The metal fine particles (c) are iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), tin (Sn), platinum (Pt) and gold ( The production method according to any one of claims 1 to 4, wherein the fine particles are at least one metal selected from the group consisting of Au).
The manufacturing method according to claim 5, wherein the (c) metal fine particles are palladium fine particles.
The production method according to any one of claims 1 to 6, wherein (c) the metal fine particles are fine particles having an average particle diameter of 1 to 100 nm.
The manufacturing method according to any one of claims 1 to 7, wherein the (a) thermoplastic resin is polyvinylidene fluoride.
The production method according to any one of claims 1 to 8, wherein an average diameter of the nanofiber is 50 to 2,000 nm.
The manufacturing method as described in any one of Claims 1 thru | or 9 including the 2nd plating process which performs another electroless-plating process after the said plating process.
The manufacturing method according to claim 10, wherein the plating step is an electroless copper plating treatment, and the second plating step is an electroless tin plating treatment.
The said spinning process is a manufacturing method as described in any one of Claims 1 thru | or 11 which is a process of producing a nanofiber aggregate as nanofiber.
The electroconductive nanofiber produced by the manufacturing method as described in any one of Claims 1 thru | or 12.
A conductive nanofiber assembly produced by the production method according to claim 12.
The conductive nanofiber aggregate according to claim 14, wherein the volume resistance value is 1 × 10 4 Ω · cm or less.