JP4895026B2 - Conductive fiber and method for producing the same - Google Patents

Description

The present invention relates to a conductive fiber and a method for producing the same.

Conventionally, in an IC manufacturing factory and a place where flammable materials are handled, if clothes are charged with static electricity, the IC can be damaged by electrostatic discharge, or the spark of the discharge can ignite the flammable material, resulting in an explosion or fire. There is a risk of occurring. For this reason, in an IC manufacturing factory or a place where a flammable substance is handled, an operator usually wears conductive clothing so as not to be charged with static electricity.

As a method for imparting electrical conductivity to textiles such as clothing, an antistatic agent is applied, an extra fine stainless steel fiber having a diameter of about 10 to 15 μm is woven in part, or the fiber surface is coated with copper sulfide. Methods such as using acrylic fibers are known.

However, fiber products incorporating ultra-fine stainless steel fibers have inferior bending resistance, have problems such as being broken and falling off, and damaging the texture of the fiber products, and the weaving of the fiber products is complicated. . In addition, in the case of acrylic fibers coated with copper sulfide, there is a drawback that the copper sulfide powder is not easily removed in a clean room.

Focusing on solving these drawbacks, many methods have been proposed in which a fiber is combined with an electron conjugated polymer to impart conductivity. For example, fibers obtained by complexing polypyrrole, which is an electron conjugated polymer after dyeing acrylic fibers (for example, Patent Document 1), and pyrrole after neutralizing vinylon fibers with an organic compound having a sulfonic acid group There are fibers (for example, Patent Document 2) in which a polymer is compounded, but these cannot be said to have sufficient conductivity, and have a problem that the strength of the polypyrrole thin film is weak and easily drops off.
JP-A-3-294579 JP-A-6-184944

The present invention has been made in view of the current state of the prior art, and an object of the present invention is to provide a fiber in which the electron-conjugated polymer film is less likely to fall off and has improved conductivity.

As a result of diligent investigations to achieve the above-mentioned object, the present inventors strongly bonded an electron conjugated polymer to the fiber by using a fiber containing a vinyl polymer having a sulfonic acid group. We have found out that we can do it and have reached the present invention.

That is, the present invention is achieved by the following means.
(1) A fiber containing a vinyl polymer having a sulfonic acid group in a solution containing aniline and / or pyrrole , which is a monomer capable of forming an electron conjugated polymer, and sulfone relative to the weight of the fiber wherein in a state where the acid group amount was immersed fiber is 0.1 mmol / g or more by polymerizing monomers, when forming a coating layer of the electron conjugated polymer to the fiber surface, the polymerization of the monomer A method for producing a conductive fiber, wherein the sulfonic acid group of a fiber containing a vinyl polymer having a sulfonic acid group is made into an H-type before performing the step .
(2) A water-swelling property in which a fiber containing a vinyl polymer having a sulfonic acid group has a degree of swelling with respect to water of 0.5 g / g or more in a solution containing a vinyl monomer having a sulfonic acid group. The method for producing a conductive fiber according to (1), wherein the polymerization is performed in a state where the fiber is immersed, so that the vinyl polymer having a sulfonic acid group is combined with the fiber.
(3) The method for producing a conductive fiber according to (2), wherein the water-swellable fiber is a fiber having a crosslinked structure and a carboxyl group.
(4) A fiber having a crosslinked structure and a carboxyl group is a fiber in which an acrylic fiber is reacted with a nitrogen-containing compound having two or more nitrogen atoms in one molecule to introduce a crosslinked structure, and a carboxyl group is introduced by hydrolysis. The method for producing a conductive fiber according to (3), which is characterized in that it exists.
(5) The method for producing conductive fibers according to (3) or (4), wherein the amount of carboxyl groups in the fiber having a crosslinked structure and carboxyl groups is 2 mmol / g or more .

The conductive fiber of the present invention is a fiber in which an electron-conjugated polymer is ionically bonded to a fiber by using a fiber containing a vinyl polymer having a sulfonic acid group to form a strong conductive film on the fiber surface. It has excellent durability and conductivity. The conductive fiber of the present invention having such performance can be used as, for example, an antistatic material, an electromagnetic shielding material, or equipment for OA equipment for countermeasures against static electricity.

The present invention is described in detail below. The vinyl polymer having a sulfonic acid group of the present invention is not particularly limited as long as it has a sulfonic acid group, and a homopolymer of a vinyl monomer having a sulfonic acid group or the monomer and another vinyl. A copolymer with a monomer can be used. Examples of vinyl monomers having a sulfonic acid group include unsaturated hydrocarbon sulfones such as vinyl sulfonic acid, p-styrene sulfonic acid, 2- (acryloylamino) -2-methyl-1-propane sulfonic acid, and methallyl sulfonic acid. Examples thereof include acids and salts thereof. Other vinyl monomers that can be used for copolymerization include styrene, ethylene, propylene, vinyl chloride, vinyl acetate, butadiene, acrylonitrile, and methacrylic acid esters such as methyl methacrylate.

The amount of the above-described vinyl polymer having a sulfonic acid group to be contained in the fiber is required to be 0.1 mmol / g or more with respect to the total weight of the fiber contained. , the good Mashiku 0.5 mmol / g or more, more preferably 1 mmol / g or more, most preferably 2 mmol / g or more. The number of ionic bonds and electron conjugated polymer and the sulfonic acid group is reduced when the sulfonic acid group amount is less than 0.1 mmol / g, have a durability of conductivity of interest is obtained. Moreover, when the amount of sulfonic acid groups exceeds 4 mmol / g, sufficient fiber physical properties may not be ensured.

As a method of incorporating a vinyl polymer having a sulfonic acid group into a fiber,
(1) Fiberizing a vinyl polymer having a sulfonic acid group (2) Kneading vinyl polymer particles having a sulfonic acid group at the time of fiber formation (3) Vinyl type having a sulfonic acid group in the formed fiber A method such as combining a polymer can be employed. In particular, when a large amount of sulfonic acid groups are contained, (3) which is not subject to restrictions during fiber formation such as spinnability is preferable.

As a method of combining the above-described vinyl polymer having a sulfonic acid group with the fiber serving as a base material in the case of (3),
A. I. Immerse the base fiber in a solution or dispersion containing a vinyl polymer having a sulfonic acid group. Mixing the base fiber, vinyl monomer having a sulfonic acid group, or vinyl monomer having a sulfonic acid group and a vinyl monomer copolymerizable with the monomer in a dispersion medium Then, a method such as polymerization can be employed.

In these compounding methods, an organic solvent or the like can be used as a solvent or a dispersion medium, but it is desirable to use water from the viewpoint of environmental load. When employing water, the fiber serving as the substrate is preferably a water-swellable fiber. In the case of a water-swellable fiber, the fiber swells when immersed, and a vinyl polymer or monomer having a sulfonic acid group enters not only the fiber surface but also the inside thereof. A vinyl polymer having an acid group can be compounded, and the coating layer of the electron conjugated polymer can be made stronger as described later. Among the above-mentioned methods A and B, the method B using a monomer having a small molecular weight can express such characteristics more effectively from the viewpoint of easy entry into the fiber.

In Method B, first, a fiber serving as a base material such as the above-described water-swellable fiber, a vinyl monomer having a sulfonic acid group or a vinyl monomer having a sulfonic acid group, and the monomer are used. A mixed solution with a polymerizable vinyl monomer is prepared. The method for preparing the mixed solution is not particularly limited. For example, the monomer is dissolved in water, an organic solvent, or a mixed solution thereof, mixed with the fiber serving as the base material, and then the polymerization initiator is simply used. Method of adding to the monomer solution, or method of mixing the fiber to be the base material after adding the polymerization initiator to the monomer solution, water or organic solvent to the base material fiber, or a mixture thereof Examples thereof include a method of dispersing in a liquid and adding a polymerization initiator and a monomer. Here, the polymerization initiator may be appropriately selected according to the type of monomer, and for example, a radical polymerization initiator such as hydrogen peroxide or an azo compound may be used. Further, the amount of the monomer in the mixed solution may be appropriately set so that the above-described amount of the sulfonic acid group is introduced into the base fiber. It is desirable to add at least wt%.

In the polymerization, the reaction system is adjusted to pH 6.0 or less. By controlling the pH to 6.0 or less, polymerization occurs and a vinyl polymer having a sulfonic acid group in the fiber is combined. In particular, when the pH is 1.0 to 4.0, many polymers are complexed in the fiber, which is industrially preferable. On the other hand, when the pH exceeds 6.0, polymerization inside the fiber hardly occurs, and in particular, the durability of the conductive film tends to be insufficient. The method for adjusting the pH to 6.0 or lower is not particularly limited, and it is sufficient that the reaction system has a pH of 6.0 or lower during the polymerization by adding an acid or the like.

The polymerization temperature is not particularly limited, but by setting it to a relatively low temperature, the polymerization rate becomes slow and many polymers are combined. However, if the polymerization rate is too slow, the polymer is not efficiently combined. Therefore, the polymerization temperature is preferably 40 to 80 ° C. The polymerization time may be appropriately set in consideration of the polymerization temperature and the monomer concentration, but is generally preferably 2 to 20 hours industrially.

When the method B is adopted, the degree of swelling of the water-swellable fiber is preferably 0.5 g / g or more, more preferably 1.0 g / g or more. When the degree of swelling is less than 0.5 g / g, the monomer having a sulfonic acid group does not sufficiently enter the fiber, and the function may not be sufficiently obtained. Moreover, when using for the use etc. which may contact moisture, such as washing, it is preferable that swelling degree is 0.5-4.5 g / g. If the degree of swelling exceeds 4.5 g / g, the fiber physical properties during water swelling may deteriorate and cause problems.

Such water-swellable fibers are not particularly limited. For example, natural fibers, synthetic fibers such as rayon and acetate, or these fibers and hydrophobic fibers such as nylon, polyester, and acrylic are graft-polymerized or crosslinked. However, among these, a fiber having a crosslinked structure and a carboxyl group can be preferably used. A fiber having a cross-linked structure and a carboxyl group has high hydrophilicity due to the carboxyl group, but the presence of the cross-linked structure can exhibit water swellability without becoming water-soluble, and the fiber physical properties can also be at a sufficient level. is there. Further, the degree of swelling with respect to water can be adjusted by adjusting the amount of carboxyl groups and cross-linked structures in the fiber. In order to obtain the degree of swelling of 0.5 g / g or more as described above, the amount of carboxyl groups depends on the degree of crosslinking and the type of counter ion of the carboxyl group, but is at least 0.5 mmol / g, preferably 2 mmol. / G or more is desirable. When the amount of carboxyl groups is less than 0.5 mmol / g, the amount of carboxyl groups is small, so that a sufficient degree of swelling cannot be obtained.

As a typical example of a fiber having a crosslinked structure and a carboxyl group, a carboxyl group-containing monomer and a hydroxyl group-containing monomer capable of forming an ester crosslinked structure by reacting with the carboxyl group are copolymerized, and Cross-linked with polyacrylic acid-based cross-linked fiber, maleic anhydride-based cross-linked fiber, alginic acid-based cross-linked fiber, or a nitrogen-containing compound having 2 or more nitrogen atoms in one molecule. Examples thereof include fibers introduced with a carboxyl group by hydrolysis after introduction of. In particular, the latter fiber has a high degree of swelling and excellent fiber strength by controlling the crosslinking and hydrolysis conditions with a nitrogen-containing compound having 2 or more nitrogen atoms in one molecule. The water-swellable fiber employed in the present invention is preferable.

A fiber in which a carboxyl group is introduced by introducing a crosslink into the acrylic fiber with a nitrogen-containing compound having 2 or more nitrogen atoms in one molecule and then hydrolyzing can be obtained by the following method.

As the acrylic fiber, a fiber formed of an acrylonitrile copolymer containing acrylonitrile homopolymer or acrylonitrile in an amount of 40% by weight or more, preferably 50% by weight or more, more preferably 80% by weight or more can be employed. The monomer copolymerized with acrylonitrile is not particularly limited and may be appropriately selected.

The acrylic fiber is subjected to crosslinking introduction treatment with a nitrogen-containing compound having 2 or more nitrogen atoms in one molecule. Examples of the nitrogen-containing compound having 2 or more nitrogen atoms in one molecule that can be used for the crosslinking introduction treatment include hydrazine compounds such as hydrazine hydrate, hydrazine sulfate, hydrazine hydrochloride, hydrazine bromate, ethylenediamine, hexamethylenediamine, Examples thereof include compounds having a plurality of amino groups such as diethylenetriamine, triethylenetetramine, and polyethyleneimine. Of these, hydrazine compounds are preferable because they are easy to react and advantageous in terms of cost.

In the crosslinking introduction treatment, a nitrile group in the acrylic fiber and a nitrogen-containing compound having 2 or more nitrogen atoms in one molecule react to form a crosslinked structure, and the nitrogen content in the fiber increases accordingly. Therefore, this increase in nitrogen content is a measure of the degree of crosslinking. In the water-swellable fiber in the present invention, when the hydrazine-based compound described above is employed, the increase in nitrogen content is preferably 0.1 to 10% by weight. In addition, the increase in nitrogen content here means the difference between the nitrogen content of the acrylic fiber before the crosslinking introduction treatment and the nitrogen content of the acrylic fiber after the treatment.

The conditions for the crosslinking introduction treatment with a nitrogen-containing compound having 2 or more nitrogen atoms in one molecule are not limited as long as a crosslinked structure is formed. Acrylic fibers are immersed in a solution of the compound, and 50 When the reaction is carried out at ˜150 ° C., favorable results are often obtained. For example, when a hydrazine compound is used as the nitrogen-containing compound having 2 or more nitrogen atoms in one molecule, it can be employed as long as the increase in nitrogen content can be adjusted to 0.1 to 10% by weight. A method of treating the above-mentioned acrylic fiber in an aqueous solution having a hydrazine compound concentration of 5 to 60% by weight at a temperature of 50 to 120 ° C. within 5 hours is industrially preferred.

The fiber subjected to the cross-linking introduction treatment with the nitrogen-containing compound having 2 or more nitrogen atoms in one molecule may be subjected to acid treatment after sufficiently removing the drug remaining in the treatment. The acid used here is not particularly limited, and examples thereof include mineral acids such as nitric acid, sulfuric acid, and hydrochloric acid, and organic acids. The conditions for the acid treatment are not particularly limited, but the treated fibers are immersed in an aqueous solution having an acid concentration of 3 to 20% by weight, preferably 7 to 15% by weight at a temperature of 50 to 120 ° C. for 0.5 to 10 hours. An example is given.

The fiber that has undergone such crosslinking introduction treatment or the fiber that has undergone further acid treatment is subsequently subjected to a hydrolysis treatment with an aqueous alkaline metal compound solution. By this hydrolysis treatment, nitrile groups that remain without being involved in the cross-linking introduction treatment, or when the acid treatment is performed after the cross-linking introduction treatment, the remaining nitrile groups are partially hydrolyzed by acid treatment. The generated amide group is converted into a carboxyl group, and a metal ion corresponding to the alkaline metal compound used is bound to the carboxyl group.

Examples of the alkaline metal compound used here include alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates, etc., and the metal species include alkali metals such as Li, Na, and K, Mg, Alkaline earth metals such as Ca and Ba can be mentioned.

The amount of the carboxyl group generated by the hydrolysis treatment is preferably 0.5 to 10 mmol / g, more preferably 2 to 8 mmol / g. When the amount of the carboxyl group is less than 0.5 mmol / g, a sufficient degree of swelling may not be obtained, and when it exceeds 10 mmol / g, the swelling becomes severe and the fiber physical properties that can be satisfied practically are obtained. May cause problems such as inability to obtain.

The conditions for the hydrolysis treatment may be appropriately set so that a necessary amount of carboxyl groups is generated, but preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight in an aqueous alkaline metal compound solution, A method of treating at a temperature of 50 to 120 ° C. for 1 to 10 hours is preferable from an industrial and fiber property viewpoint.

As described above, after introducing crosslinking into the acrylic fiber with a nitrogen-containing compound having 2 or more nitrogen atoms in one molecule, a fiber having a carboxyl group introduced by hydrolysis can be obtained. When the fiber is reduced with a reducing agent, the vinyl monomer having a sulfonic acid group can be polymerized without adjusting the pH to 6 or less. The conditions for the reduction treatment and the reducing agent are not particularly limited.

The conductive fiber of the present invention is obtained by coating a fiber containing a vinyl polymer having a sulfonic acid group as described above with an electron conjugated polymer. The electron conjugated polymer is not particularly limited, and polyaniline, polypyrrole, polythiophene, polyfuran, polyindole, polyselenophene, and derivatives of these compounds can be used.

As a method of coating a fiber containing a vinyl polymer having a sulfonic acid group with an electron conjugated polymer,
a. Dipping the fiber in an electron conjugated polymer solution b. Polymerization may be performed by immersing the fiber in a monomer solution capable of forming an electron conjugated polymer. In any method, the sulfonic acid group in the fiber containing the vinyl polymer having a sulfonic acid group needs to be in the H form, that is, in the form of —SO ₃ H, before the polymerization. By making the sulfonic acid group an H-type, an ionic bond with the electron conjugated polymer can be easily formed, the film becomes strong, and peeling can be reduced.

Further, compared with the method a in which an electron conjugated polymer is already formed in the solution, the method b is soaked in the monomer solution, so that the monomer enters the fiber and the electron conjugated system is also formed in the fiber. Since a polymer is formed, the coating becomes strong and preferable. In particular, as described above, the fiber containing a vinyl polymer having a sulfonic acid group obtained using a water-swellable fiber has a sulfonic acid group complexed to the inside of the fiber. It can be preferably used because the polymer can be ionically bonded and the coating layer of the electron conjugated polymer becomes stronger.

Although it does not specifically limit as b method, For example, (1) The fiber containing the vinyl polymer which has a sulfonic acid group in the process liquid containing the monomer which can form an electron conjugated polymer And (2) a monomer capable of forming an electron conjugated polymer, an oxidation polymerizer, and a sulfonic acid in a treatment solution to which a dopant is added if necessary. Examples thereof include a method of immersing a fiber containing a polymer having a group. In particular, in the case of (1), the monomer penetrates into the inside of the fiber to form an electron conjugated polymer, so that it is preferable to obtain a strong coating layer of the electron conjugated polymer.

In the present invention, aniline and / or employing a pyrrole as monomer capable of forming a electron conjugated polymer.

Examples of the oxidation polymerizer include permanganates such as permanganic acid and potassium permanganate, chromic acids such as chromic trioxide, peroxides such as hydrogen peroxide and benzoyl peroxide, and peroxydisulfuric acid. Peroxyacids or salts thereof, oxygen acids such as sodium hypochlorite or salts thereof, ferric chloride, ferric sulfate, ferric nitrate, ferric citrate, ferric p-toluenesulfonate Transition metal compounds such as potassium persulfate, ammonium persulfate, and ferric perchlorate. Moreover, such an oxidation polymerization agent may be used alone or in combination of two or more.

The concentration of the monomer capable of forming the electron conjugated polymer in the treatment liquid may be appropriately set in consideration of conductivity and durability of the coating. For example, in the case of pyrrole, a sulfonic acid group is added. It is preferable to make it 0.1 to 5 weight% with respect to the fiber containing the vinyl-type polymer which has. When the amount is less than 0.1% by weight, the amount of the electron conjugated polymer to be complexed is insufficient, which is not preferable because it causes a decrease in conductivity. On the other hand, when the amount exceeds 5% by weight, the amount of the electron conjugated polymer becomes too large, and a lot of electron conjugated polymers that cannot be ionically bonded to the sulfonic acid group may be generated, which may cause dropping. It is not preferable.

Moreover, it is preferable to set it as 0.5-5 times the number-of-moles of the monomer which can form an electron conjugated polymer as the addition amount of an oxidation polymerization agent. When it is less than 0.5 times, the polymerization rate of the electron conjugated polymer becomes too slow, which is not industrially preferable. On the other hand, when it exceeds 5 times, the molecular weight of the electron conjugated polymer is reduced, which causes a decrease in conductivity.

The polymerization reaction time for obtaining the electron conjugated polymer is preferably 30 minutes or more, more preferably 2 hours or more. If it is less than 30 minutes, the polymerization of the electron conjugated polymer does not proceed sufficiently, and good conductivity cannot be obtained, which is not preferable.

The polymerization reaction temperature for obtaining the electron conjugated polymer is preferably 30 to -20 ° C. When the reaction temperature exceeds 30 ° C., the molecular weight of the electron conjugated polymer becomes small, so that good conductivity cannot be obtained.

Moreover, when superposing | polymerizing for obtaining an electron conjugated polymer, if a dopant is used together, electroconductivity can be improved further. Examples of the dopant include halogens such as iodine and bromine, Lewis acids such as phosphorus pentafluoride, proton acids such as hydrogen chloride and nitric acid, p-toluenesulfonic acid, naphthalenesulfonic acid, p-styrenesulfonic acid, A vinyl monomer such as 2- (acryloylamino) -2-methyl-1-propanesulfonic acid or unsaturated hydrocarbon sulfonic acid such as methallylsulfonic acid is homopolymerized or copolymerized with other monomers. Molecular dopants can be used.

From the viewpoint of safety, water is preferably used industrially as the solvent for the treatment liquid containing the monomer, the oxidation polymerizer, the dopant and the like that can form the above-described electron conjugated polymer, but methanol, ethanol Organic solvents such as aliphatic alcohols such as n-propanol, i-propanol, i-butanol and t-butanol, ethers such as diethyl ether and tetrahydrofuran, and aliphatic ketones such as acetone and methyl ethyl ketone can also be used. These can be appropriately selected according to the fiber containing the monomer, the oxidation polymerizer, the dopant and the vinyl polymer having a sulfonic acid group, and can be used alone or in admixture of two or more.

The drying temperature after coating the electron-conjugated polymer as described above is not particularly limited, but it is preferably as low as possible, preferably 40 to 105 ° C, more preferably 40 to 80 ° C. Is good. A temperature of 105 ° C. or higher is not preferable because good conductivity cannot be obtained.

Since the conductive fiber of the present invention described above uses a fiber containing a vinyl polymer having a sulfonic acid group, the sulfonic acid group and the electron conjugated polymer are ionically bonded to each other so that the conductive fiber is difficult to peel off. A functional film is formed. In particular, when a water-swellable fiber is used as a base fiber of a fiber containing a vinyl polymer having a sulfonic acid group, a sulfonic acid group is introduced not only to the fiber surface but also to the inside of the fiber. Since the ionic bond between the sulfonic acid group and the electron conjugated polymer is formed even inside the fiber and the number of ionic bonds increases, the conductive film becomes stronger. Such a conductive fiber of the present invention exhibits high conductivity and is excellent in durability with very little loss of coating due to friction or the like.

The present invention will be specifically described by the following examples, but the present invention is not limited to the following examples. Parts and percentages in the examples are on a weight basis unless otherwise indicated. Moreover, the swelling degree of the fiber described in an Example, volume specific resistance value, the amount of sulfonic acid groups, and durability of the film were calculated | required with the following method.

(1) Swelling degree with respect to water The fiber is absolutely dried, and the weight is measured (X [g]). Next, the fiber is immersed in water for 30 minutes or more, put into a centrifuge having a distance from the center to the sample of 11.5 cm, dehydrated at 1200 rpm for 5 minutes, and the weight after dehydration is measured (Y [g] ). The degree of swelling is calculated by the following formula.
Swelling degree [g / g] = (Y−X) / X

(2) Volume resistivity value In advance, the fineness T [dtex] and specific gravity d [g / cm ³ ] of the fiber are measured by a conventional method. Next, the fiber is scored in a 0.1% Neugen HC aqueous solution at a bath ratio of 1: 100 at 60 ° C. for 30 minutes, washed with running water, and dried at 70 ° C. for 1 hour. This fiber is cut into a length of about 6 to 7 cm and left in an atmosphere of 20 ° C. and a relative humidity of 65% for 3 hours or more. The obtained fibers (filaments) are made into five bundles, and a conductive adhesive is applied to about 5 mm on one end of the fiber bundle. In a state where a load of 8.83 mN / tex is applied to the fiber bundle, the conductive adhesive is applied to a position about 5 cm away from the position where the conductive adhesive is applied (between the conductive adhesives at this time). The distance is L [cm]), and the measurement sample. An electrode was connected to the application part of the conductive adhesive in a state where a load of 8.83 mN / tex was applied to the measurement sample, and the resistance R [Ω] when DC 500 V was applied was set to High REISTANCE METER 4329A (YOKOGAWA-HEWLETT The volume resistivity was calculated from the following formula. It is desirable that this value is less than 10 ⁴ Ω · cm for a level called conductivity. If this value is exceeded, it will be difficult to obtain conductivity. The lower limit of this measurement is 10 ² Ω · cm.
Volume resistivity [Ω · cm] = (R × T × 10 ⁻⁶ ) / (L × d)

(3) 1 g of sulfonic acid-based fiber was immersed in 50 mL of 1N-HCl aqueous solution for 30 minutes, sufficiently washed with water and then dried. About 0.2 g of the dried fiber is precisely weighed (W1 [g]), 50 mL of water is added thereto, and then a titration curve is prepared according to a conventional method with 2 g of sodium chloride and then with a 0.1 mol / l sodium hydroxide aqueous solution. Asked. From the titration curve, the amount of sodium hydroxide aqueous solution consumed by the sulfonic acid groups (V1 [ml]) was determined, and the amount of sulfonic acid groups was calculated by the following equation.
Amount of sulfonic acid group [mmol / g] = (0.1 × V1) / W1
The amount of carboxyl groups was also determined in the same manner as in the case of sulfonic acid groups except that the amount of sodium chloride added was 0.2 g.

(4) Durability fibers of the coating were rubbed 20 times on white paper, and the state of the electron conjugated polymer coating adhering to the white paper was determined in the following four stages.
◎: No dropout ○: No dropout △: Some dropout ×: Many dropouts

Moreover, the preparation method of the fiber described in an Example is as follows.
<Water-swellable fiber A>
A spinning stock solution prepared by dissolving 10 parts of an acrylonitrile-based polymer composed of 90% acrylonitrile and 10% methyl acrylate in 90 parts of a 48% aqueous sodium thiocyanate solution is spun, drawn, and dried according to a conventional method to obtain a 1.7 dtex acrylic fiber. a was obtained.
Acrylic fiber a was added to a 15% hydrazine aqueous solution, subjected to hydrazine crosslinking introduction treatment at 106 ° C. for 3 hours, and washed with water. Next, acid treatment was performed in a 3% nitric acid aqueous solution at 99 ° C. for 1 hour, followed by washing with water and dehydration. Subsequently, it was added to a 4.5% aqueous sodium hydroxide solution, hydrolyzed at 90 ° C. for 2 hours, and washed with ion-exchanged water to obtain a water-swellable fiber A. The degree of swelling of the fibers with respect to water was 1.5 g / g, and the amount of carboxyl groups was 6.5 mmol / g.

<Water-swellable fiber B>
The acrylic fiber a was added to a 15% hydrazine aqueous solution, subjected to hydrazine crosslinking introduction treatment at 110 ° C. for 4.5 hours, and washed with water. Next, acid treatment was performed in a 3% nitric acid aqueous solution at 99 ° C. for 1 hour, followed by washing with water and dehydration. Subsequently, it was added to a 4.5% aqueous sodium hydroxide solution, hydrolyzed at 90 ° C. for 2 hours, and washed with ion-exchanged water to obtain a water-swellable fiber B. The degree of swelling of the fiber with respect to water was 1.1 g / g, and the amount of carboxyl groups was 6.0 mmol / g.

[Example 1]
The water-swellable fiber A was immersed in an aqueous solution containing 417% sodium p-styrenesulfonate (SPSS) and adjusted to pH 2 using hydrochloric acid. Subsequently, 2.7% hydrogen peroxide was added to the fiber A, and polymerization was performed by heating at 60 ° C. for 5 hours, followed by washing with water, dehydration, and drying. The obtained fiber was repeatedly subjected to acid treatment at 30 ° C. for 30 minutes in a 5% nitric acid aqueous solution three times to obtain a fiber 1 containing a vinyl polymer having a sulfonic acid group. The amount of sulfonic acid group of the fiber was 2.0 mmol / g.
Next, the fiber 1 is immersed in an aqueous solution containing 4% pyrrole and 50% ferric chloride hexahydrate with respect to the fiber, polymerized at 5 ° C. for 3 hours, and then thoroughly washed with water. Dried at 60 ° C. The properties of the obtained fiber are shown in Table 1.

[ Reference Example 1 ]
In Example 1, instead of the fiber 1, a fiber of Reference Example 1 was prepared using a fiber obtained in the same manner except that the acid treatment with nitric acid when the fiber 1 was prepared was not performed. The properties of the obtained fiber are shown in Table 1.

[Example 3]
In Example 1, instead of the fiber 1, using the fiber obtained in the same manner except that the SPSS concentration at the time of creating the fiber 1 was 104% with respect to the fiber A, the fiber of Example 3 was used. Created. The properties of the obtained fiber are shown in Table 1.

[Example 4]
In Example 1, the fiber of Example 4 was produced in the same manner except that the water-swellable fiber B was used instead of the water-swellable fiber A. The properties of the obtained fiber are shown in Table 1.

[Example 5]
The fiber 1 containing a vinyl polymer having a sulfonic acid group was immersed in an aqueous solution containing 10% aniline and 50% ferric chloride hexahydrate and polymerized at 5 ° C. for 3 hours. Thereafter, it was thoroughly washed with water and dried at 60 ° C. The properties of the obtained fiber are shown in Table 1.

[Comparative Example 1]
A fiber obtained by treating a water-swellable fiber B with a 5% nitric acid aqueous solution is immersed in an aqueous solution containing 4% pyrrole and 50% ferric chloride hexahydrate, and polymerized at 5 ° C. for 3 hours. After performing, it washed thoroughly with water and dried at 60 degreeC. The properties of the obtained fiber are shown in Table 1.

[Comparative Example 2]
A fiber obtained by treating acrylic fiber a with a 5% nitric acid aqueous solution was immersed in an aqueous solution containing 4% pyrrole and 50% ferric chloride hexahydrate, and polymerized at 5 ° C. for 3 hours. Thereafter, it was thoroughly washed with water and dried at 60 ° C. The properties of the obtained fiber are shown in Table 1.

In Examples 1 and 3 to 5 , the volume resistivity value is less than 10 ⁴ Ω · cm, which is a conductive level, and the durability of the coating is also at a practical level. On the other hand, in Comparative Examples 1 and 2, since less than 0.1 mmol / g of sulfonic acid groups were introduced into the base fiber, the durability of the coating was poor, and the volume resistivity values were also in Examples 1 and 3. The result was higher than -4 .

Claims (5)

A fiber containing a vinyl polymer having a sulfonic acid group in a solution containing aniline and / or pyrrole , which is a monomer capable of forming an electron conjugated polymer, and the amount of the sulfonic acid group relative to the weight of the fiber Before the polymerization of the monomer in order to polymerize the monomer in a state where the fiber is immersed in an amount of 0.1 mmol / g or more and form a coating layer of the electron conjugated polymer on the fiber surface. And a sulfonic acid group of a fiber containing a vinyl polymer having a sulfonic acid group is made H-shaped . A fiber containing a vinyl polymer having a sulfonic acid group is immersed in a solution containing a vinyl monomer having a sulfonic acid group and a water-swellable fiber having a degree of swelling with respect to water of 0.5 g / g or more. 2. The method for producing conductive fibers according to claim 1, wherein the polymerization is carried out in a state of being made to make the vinyl polymer having a sulfonic acid group complex with the fibers. The method for producing a conductive fiber according to claim 2, wherein the water-swellable fiber is a fiber having a crosslinked structure and a carboxyl group. The fiber having a crosslinked structure and a carboxyl group is a fiber in which an acrylic fiber is reacted with a nitrogen-containing compound having 2 or more nitrogen atoms in one molecule to introduce a crosslinked structure, and a carboxyl group is introduced by hydrolysis. The manufacturing method of the conductive fiber of Claim 3 characterized by the above-mentioned. The method for producing conductive fibers according to claim 4 or 5, wherein the amount of carboxyl groups in the fiber having a crosslinked structure and carboxyl groups is 2 mmol / g or more .