JPH0227442B2 - DODENSEIAKURIRUKEIGOSEISENIOYOBISONOSEIZOHOHO - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a conductive acrylic synthetic fiber and a method for producing the same. In general, synthetic fibers have poor antistatic properties, and especially in low-humidity environments during winter, static electricity is generated significantly in clothing, clothing, etc.
Improvements have been desired not only in interior design, bedding, etc., but also in industrial applications, and various proposals have been made.
One way to overcome these drawbacks is to use metal fibers, metal-plated fibers, or carbon fibers, and by mixing them with other fibers, the antistatic properties are improved, but these fibers are generally Because its physical properties, luster, color, dyeability, etc. are different from ordinary synthetic fibers and natural fibers, special blending, spinning, dyeing, and processing methods are required, and its use is limited to carpets, etc. is normal. In order to improve the above-mentioned drawbacks of conductive fibers, a method has been proposed in which a conductive substance such as carbon black is mixed into part or all of the synthetic fibers. The method of mixing a conductive substance into the entire fiber requires a large amount of the conductive substance and has many disadvantages such as high cost, reduced operability and productivity, and abnormal dyeability. Methods for incorporating a conductive substance into a portion of the fibers can be broadly classified into a composite spinning method, a sea-island fiber spinning method, and a conductive layer streak dispersion spinning method. In Japanese Patent Publication No. 52-31450 and Japanese Patent Application Laid-open No. 51-143723, sheath-core type or side-by-side type conductive composite fibers have been proposed, but they are difficult to manufacture, have low productivity, and are prone to fibrillation. Deterioration of conductivity, change in dyeability, deterioration of appearance, etc. occur due to peeling of each component. JP 56-3447, JP 56-68109
No. 56-58008 and JP-A-56-58008 attempt to improve the above-mentioned drawbacks of composite fibers by using more complicated manufacturing methods, but the manufacturing difficulties and low productivity are still significant, and the performance is still high. , it seems that only a small improvement in quality can be expected. JP 53-31971, JP 57-20404, JP 54-112212, JP 55-45856, JP 52-103525
The publication proposes a method of continuously orienting and dispersing conductive substances such as carbon black, silver, copper, aluminum, and iron in the fiber axis direction. In this case, it is necessary to use a block polyether or a copolymer obtained by grafting a vinyl monomer such as AN to a block polyether as a dispersion matrix polymer for the conductive substance. Low heat resistance and low strength and elongation deteriorate the physical properties and performance of conductive fibers. The present inventors have arrived at the present invention as a result of intensive studies to eliminate the above-mentioned drawbacks. The object of the present invention is to provide a conductive acrylic synthetic fiber having excellent conductivity, excellent processability, and high product performance.
Another object of the present invention is to provide an easy and inexpensive method for producing acrylic synthetic fibers with excellent conductivity. The present invention provides a conductive elastic material comprising 50 to 90 parts of an acrylic polymer, 10 to 50% by weight of conductive fine particles, and 90 to 50% by weight of an elastic polymer that is miscible but incompatible with the acrylic polymer. It is a conductive acrylic synthetic fiber which consists of 50 to 10 parts of a polymer and has a structure in which a conductive elastic polymer is dispersed in discontinuous long and thin islands in the fiber axis direction. and 10 to 50% by weight of conductive fine particles and 90 to 50% of an elastomeric polymer that is miscible but incompatible with the acrylic polymer.
A conductive elastic polymer solution consisting of (acrylic polymer) / (conductive elastic polymer) = 50 /
It is characterized by mixing at a ratio of 50 to 90/10 (weight ratio), spinning into a coagulation bath at a spinning draft of 0.2 to 2.0, washing with water, drying, and shrinking under moist heat. The fiber of the present invention contains 50 to 90 parts of an acrylic polymer, preferably 55 to 85 parts, more preferably 50 to 10 parts of an elastomeric polymer containing conductive fine particles of 60 to 80 parts, The amount is preferably 45 to 15 parts, more preferably 40 to 20 parts. If the content of the acrylic polymer exceeds 90 parts and the content of the conductive elastic polymer is less than 10 parts, the electrical conductivity will not be sufficiently developed because the electrically conductive component will be small and the elongation in the fiber axis direction will be insufficient. Also, if the acrylic polymer is less than 50 parts and the conductive elastic polymer exceeds 50 parts, the dispersion form of the conductive elastic polymer component in the fiber will become abnormally large.
In addition, the distribution of shapes becomes wider, leading to frequent troubles during thread breakage and troubles during spinning, weaving and knitting processes during the manufacturing process, and the dyeing luster of the fibers decreases. The acrylic polymer used in the present invention preferably contains at least 80% by weight of acrylonitrile, and less than 20% by weight of copolymerizable monomers, such as acrylics such as methyl acrylate, methyl methacrylate, and ethyl acrylate. Acid esters or methacrylic acid alkyl esters, amides such as acrylamide and methacrylamide, and their N-mono- or N-disubstituted amides, vinyl acetate, sulfonic acid group-containing monomers such as styrene sulfone, and their It can contain salts, etc. In particular, 0.3 to 2.5% by weight of allylsulfonic acid or methallylsulfonic acid and their salts, preferably
Copolymerization of 0.5 to 2.0% by weight not only improves the dyeability but also suppresses the deterioration of heat resistance by suppressing the generation of countless minute voids. Particularly preferred is one composed of 90% by weight or more of acrylonitrile, 0.5 to 2.0% by weight of sodium methallylsulfonate, and methyl acrylate or vinyl acetate and has a molecular weight of 45,000 to 60,000. For materials requiring flame retardancy, acrylic polymers containing 80% by weight or less of acrylonitrile and 20 to 60% by weight of vinyl chloride or vinylidene chloride are preferred, and more preferably 30 to 50% by weight of vinyl chloride or vinylidene chloride. % and a sulfonic acid group-containing monomer and 0.5 to 3.0% by weight of acrylonitrile. Further, the elastic polymer applied to the present invention needs to be miscible with the acrylic polymer but not compatible with the acrylic polymer. Examples of such elastic polymers include polyurethane polymers, acrylonitrile-butadiene rubber, acrylic rubber, etc., and polyurethane polymers are preferred in terms of physical properties such as solvent solubility, fiber forming properties, and rubber elasticity. Polyurethane polymers include polyester type, polyether type, polyester ether type,
It is a general term for polyesteramide type and polythioether type polyurethanes, and in detail, ethylene glycol, propylene glycol, butylene glycol, hexamethylene glycol, 1,4-
Polyesters consisting of cyclohexyl glycol, P-xylene glycol, or bisphenol A and adipic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid, or γ-lactone, adipic acid-diethanolamide or terephthalic acid-bis-propanolamide, and Polyesteramide made from the above-mentioned dicarboxylic acids, diethylene glycol, triethylene glycol, 1,4-phenylenebisoxyethyl ether or 2,2'-diphenylpropane-4,4
- Polyester ethers made from bisoxyethyl ether and the aforementioned dicarboxylic acids, polyethers made from ethylene oxide, propylene oxide, and tetrahydrofuran, polythioethers such as thiodiglycol, etc. Molecular weight
A linear polymer having 200 to 3000 terminal hydroxyl groups is mixed with an organic diisocyanate such as 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate,
Examples include polyurethane polymers obtained by reacting 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, or 1,5-naphthylene diisocyanate with a dihydric alcohol chain extender by a known polymerization method. The polyurethane polymer is preferably a polyester type or polyester ether type polyurethane, and the degree of polymerization of the polyurethane polymer is preferably low. For example, in terms of solution viscosity, the viscosity of a dimethylformamide solution with a degree of polymerization concentration of 20% by weight at 50° C. is preferably 700 poise or less, particularly preferably 500 poise or less. It is necessary that the acrylic polymer and the elastic polymer have miscibility but are incompatible. When an acrylic polymer and an elastic polymer are mixed together (for example, when the solutions of both are mixed or when the other polymer is dissolved and mixed in one solution), one component will not gel or aggregate, and one component will not form in the other. Indicates that it is well dispersed and mixed in the ingredients. In addition, when there is no compatibility, when an acrylic polymer is mixed with an elastic polymer, it can be observed not only with the naked eye but also with a microscope (approx.
600 to 1000 times), it can be distinguished by the fact that the mixed solution is heterogeneous. The conductive elastic polymer is composed of 10 to 50% by weight of conductive fine particles and the above-mentioned elastic polymer which is miscible but incompatible with the acrylic polymer. When the amount of conductive fine particles is less than 10% by weight, conductivity is not sufficiently imparted, and when it exceeds 50% by weight, not only operability and processability are significantly reduced, but also the conductivity reaches saturation, which is extremely inconvenient. The conductive fine particles applicable to the present invention include particles of carbon black, metals such as silver, copper, aluminum, and iron, tin oxide, zinc oxide, and titanium oxide coated with tin oxide or zinc oxide. The particle size of these particles is usually 1 μm or less, preferably 0.7 μm.
A thickness of less than m, particularly preferably about 0.5 μm to 0.01 μm, is used. Carbon black as a conductive particle has a particle size of
It is preferably 1 μm or less, and its type is not particularly limited, and examples thereof include so-called acetylene black, oil furnace black, channel black, and the like. Metal particles such as silver, copper, aluminum, iron, etc. are usually those having a particle size of 1 μm or less, preferably 0.5 μm or less, and having a resistivity of 10 Ω·cm or less. Regarding the electrical conductivity of conductive zinc oxide or tin oxide, the specific resistance in powder form is preferably about 10 ⁴ Ω·cm or less, particularly preferably about 10 ² Ω·cm or less, and most preferably about 10 ¹ Ω·cm or less. In reality, values of about 10 ² Ω·cm to ^{10 −2} Ω·cm have been obtained, and can be suitably applied to the purpose of the present invention. Titanium oxide having a coating of zinc oxide or tin oxide has a particle size and specific resistance in powder form comparable to those of zinc oxide or tin oxide. These films can be formed, for example, by a vacuum deposition method, a method of depositing a metal compound and baking it to form an oxide, or a method of partially reducing it. When carbon black is used as conductive particles, it has the disadvantage that the color of the fiber becomes black, but since it has a small specific gravity and a cluster (micro chain) structure, it can be used in a small amount. The content of black in the conductive elastic polymer is preferably 10 to 45% by weight, more preferably 15 to 40% by weight. Since conductive particles other than carbon black have a large specific gravity, the amount used is also larger than in the case of carbon black, which causes an increase in cost, but there is a great advantage that the fiber color is not black. In particular, white conductive fibers can be obtained using conductive tin oxide, zinc oxide, and titanium oxide with surface coatings thereof. In the fiber of the present invention, the conductive elastic polymer has a structure in which it is elongated but discontinuously extended in the fiber axis direction as a large number of island-like components. The presence of a large number of conductive components in the fiber cross-sectional direction and in the fiber axis direction effectively performs the functions of static elimination and discharge. In particular, since it exists in the form of elongated, discontinuous islands, having many sharp edges also seems to have the effect of improving antistatic performance. Furthermore, the use of an elastic polymer as a conductive component is also essential for maintaining antistatic performance. When fibers are subjected to everyday external forces such as tension and bending, and deformation, and when an elastic polymer is not used as the conductive component, repeated external forces and deformation can cause the boundary between conductive particles and the polymer containing them to This has the disadvantage that cracks occur in the conductivity, resulting in a significant decrease in conductivity. Therefore, by combining the polymers shown in the present invention, it is possible to obtain conductive acrylic synthetic fibers that are inexpensive, have high performance, have good operability and processability, and do not exhibit a decrease in conductivity against external forces. The fiber of the present invention is obtained by mixed spinning of an acrylic polymer solution and an elastomeric polymer (referred to as a conductive elastomer) solution that is miscible but incompatible with the acrylic polymer containing conductive fine particles. . The above-mentioned acrylic polymer can be used, and a solution can be prepared by dissolving the acrylic polymer in a solvent or by polymerizing the acrylic polymer in a solvent. As the solvent for the acrylic polymer, dimethylformamide, dimethylsulfoxide, dimethylacetamide, ethylene carbonate, γ-butyrolactone, and other organic solvents, and inorganic solvents such as nitric acid, rhodanate aqueous solution, zinc chloride aqueous solution, etc. can be used. As the solvent for the elastic polymer, a solvent for the elastic polymer can be used, but it is preferable to use the same solvent as that used for the acrylic polymer in terms of coagulation properties, solvent recovery, etc. Particularly preferably, the acrylic polymer and polyurethane are each subjected to solution polymerization using dimethylformamide as a common solvent. When dimethylformamide is used as a solvent, the polymer concentration of the acrylic polymer solution is 15 to 35% by weight, preferably 20 to 30% by weight.
% by weight, and the polymer concentration of the polyurethane solution may be lower than or approximately the same as that of the acrylic polymer. The acrylic polymer solution and the elastomeric polymer solution must be mutually miscible but incompatible, and it is also necessary that the conductive fine particles remain in the elastomeric polymer solution. The viscosity of the acrylic polymer solution and elastomeric polymer solution also has a significant impact on operability, product quality, and conductive performance. The viscosity here refers to the viscosity at the same polymer concentration and at the same temperature. The viscosity at 50° C. of a dimethylformamide solution with a polymer concentration of 20% by weight is usually used. For example, if the viscosity of the acrylic polymer solution is slightly lower than the viscosity of the elastic polymer solution, sufficient deformation of the elastic polymer will not occur during fiber spinning and spinning/drawing, resulting in uneven denier in that area. Otherwise, thread breakage may occur or insufficient conductivity may result. On the other hand, when the viscosity of the acrylic polymer solution is higher than the viscosity of the elastic polymer solution, the elastic polymer is sufficiently stretched during spinning and spinning and drawing, and is formed as island-like components elongated in the fiber axis direction. Therefore, phenomena such as denier unevenness and decrease in operability are not observed, and the conductivity is also good. The viscosity ratio of the acrylic polymer solution and the elastic polymer solution is preferably 100/1 or less, more preferably 1/2 to 50/1. Conductive elastic polymer contains 10 to 50% by weight of conductive fine particles
and 90 to 50% by weight of an elastic polymer. When carbon black is used as the conductive particles, the carbon black is preferably 10 to 45% by weight, more preferably 15 to 40% by weight, and the elastic polymer is preferably 10 to 45% by weight.
The content is 90 to 55% by weight, more preferably 85 to 60% by weight. Various methods can be used to mix the conductive fine particles into the elastic polymer. For example, there are methods such as adding it when polymerizing the elastic polymer or adding it to the elastic polymer solution, but care must be taken to apply sufficient stirring force to disperse the conductive fine particles and in the case of carbon black. The purpose of stirring is to avoid cutting the carbon black clusters.
After adding conductive fine particles, this conductive elastic polymer solution or a spinning dope containing a mixture of an acrylic polymer solution and a conductive elastic polymer solution is applied to paper, cloth, a sintered metal filter, a wire mesh, or a porous polymer membrane. It is preferable to spend some time. The overaccuracy here is about 10μ
It is sufficient to remove 100% of the particles. Various dispersants can also be used to improve the dispersibility and stability of the conductive particles in the elastomeric polymer. Various mixing methods can be used to mix the acrylic polymer solution and the conductive elastic polymer solution.
It is better to check the mixing state using a microscope or the like. In the mixed liquid, the conductive elastic polymer, which appears black under a microscope, is suspended and dispersed in the acrylic polymer solution as many small spheres or deformed spheres, but the size of this dispersion is uniform and
The thickness is preferably about 100μ, more preferably about 20 to 70μ. A spinning dope obtained by mixing the two is spun into a coagulation bath using an ordinary spinneret. As the coagulation bath, it is preferable to use an aqueous solution of the solvent used in the spinning dope, but for special purposes, an aqueous solution of other solvents, kerosene, isopropyl alcohol, and other solvents can be used. The coagulation bath conditions can be the same as those used for spinning acrylic synthetic fibers, but a lower coagulation bath temperature is preferable for improving conductivity. When a dimethylformamide aqueous solution is used, the dimethylformamide concentration is 50 to 65% by weight, more preferably 55 to 60% by weight, and the temperature is preferably 20°C or lower, more preferably 5 to 15°C. The fibers spun into the coagulation bath are wound onto the first roller at a spinning draft value (ratio of the winding speed of the first roller to the spinning speed at the spinneret surface) of 0.2 to 2.0. If the spinning draft is less than 0.2, the orientation during coagulation will not be sufficient and the fiber will be brittle.
In addition, the development of conductivity is insufficient, and if the spinning draft exceeds 2.0, there will be a decrease in conductivity, a decrease in product quality such as an increase in voids and a decrease in dyeability, and a decrease in operability such as an increase in yarn breakage. . The spinning draft is preferably 0.3 to 1.5, more preferably 0.4 to 1.0. The fibers wound up by the first roller are immediately subjected to spinning and drawing in a plurality of spinning baths having different solvent concentrations and temperatures. Spinning and drawing is usually
It is carried out at a temperature lower than 95°C, preferably 50 to 90°C, more preferably 60 to 85°C, particularly preferably 50 to 70°C.
It is preferable to carry out two-stage stretching in a spinning bath at 70 to 90°C. When the temperature during spinning and drawing exceeds 95°C, conductivity decreases. The spinning draw ratio is usually 2 to 7.
Do this twice, preferably 3 to 6 times. If the stretching ratio is low, the fibers may not be stretched sufficiently, resulting in a decrease in operability such as cutting of the fibers in the drying process or the stretching process, and a decrease in quality such as strength and elongation, dyeability, etc. After spinning and drawing, the fibers undergo a water washing process to remove residual solvent.
After the oil application step, drying and crushing is performed.
Drying and baking must be carried out sufficiently, preferably using a combination of hot air at 100 to 180°C and heated rollers at 100 to 150°C until the moisture content becomes 1% or less. In the drying process, the torque motor etc.
% shrinkage is also preferable for improving conductivity. The dry and burnt fibers are stretched if necessary and then shrunk under moist heat. The stretching is preferably 1.6 times or less. This shrinkage treatment improves the conductivity of the fibers and improves the uniformity of the conductivity. Shrinkage is carried out with moist heat at 100-150°C, preferably 115-130°C. Treatment may be continuous or patchy, but it is important not to apply as much tension to the fibers during treatment. A shrinkage treatment method that generates a large amount of tension does not provide much improvement in conductivity. A shrinkage rate of approximately 5 to 30% is sufficient, but the optimum value of the shrinkage rate is determined depending on the composition of the acrylic polymer, the content of the conductive elastic polymer, and the manufacturing process conditions. The fibers that have undergone the shrinking process are subjected to oiling, crimping, etc., if necessary, and are made into products in the form of filaments, tows, or staple fibers. The conductive acrylic synthetic fiber of the present invention does not require the use of special polymers or monomers, does not require special equipment or manufacturing processes, and has sufficient conductivity, processing performance, and other product performance. It has superior features not found in the past. In particular, a feature of the fibers of the present invention is that there is no or very little decrease in conductivity when subjected to external forces such as tension and bending, and for this reason, there is no change in conductivity over time during use, and the conductivity remains good for a long time. Having good performance can also be mentioned. The conductive acrylic synthetic fibers of the present invention can be used not only for carpets, work clothes, various uniforms, and other clothing and interior products that are susceptible to static electricity in daily life, but also for electronic devices that do not want to be affected by static electricity. It is very useful as a shielding material for industrial equipment, industrial materials, etc. The present invention will be explained in more detail below with reference to Examples. To measure the conductivity of fibers, cut a fiber bundle of 1,000 to 10,000 denier into lengths of about 5 to 15 cm, and glue both ends of the fiber bundle with conductive adhesive (DOTITE D-550 Fujikura Kasei).
Co., Ltd., and this part is firmly grasped with a crimp, and a voltage of 100 V is applied between them to measure the electrical resistance value R (Ω/cm). The electric specific resistance value (Ω・cm) of the fiber is determined by the following formula. =R x denier/q x 10 ⁵ x specific gravity (Ω·cm) Note that parts and percentages shown in the examples indicate parts by weight and percentages by weight unless otherwise specified. Example 1 An acrylic polymer having a composition of acrylonitrile: methyl acrylate: sodium methallylsulfonate = 91.2:8.0:0.8 (%) was solution polymerized in dimethylformamide (hereinafter referred to as DMF) to remove the remaining monomers. After recovery and removal, an acrylic polymer solution with a polymer concentration of 24% was obtained. In addition, polymerization was started with 300 parts of polyethylene adipate having a MW of 1500, 27 parts of 1,4-butanediol, and 113 parts of diphenylmethane diisocyanate (hereinafter referred to as MDI) in 600 parts of DMF. Finally, a polyurethane solution with a polymer concentration of 15% was obtained. Carbon black (acetylene black) as shown in Table 1 was added to the polyurethane solution based on the total amount of polyurethane and carbon black. A spinning dope is prepared by mixing a polyurethane solution to which carbon black has been added and an acrylic polymer solution so that 30 parts of carbon black-added polyurethane and 70 parts of acrylic polymer are added. The sample was spun into a coagulation bath of DMF:water = 60:40 (%) at 15°C from a nozzle having a diameter of 100%. The spun yarn is wound at the first rotor speed so that the spinning draft is 0.7, the spinning ratio is 5 times, washed with water, oiled, dried and burned, and then shrunk by 15% under moist heat at 120°C to produce a 3 denier fiber. Obtained. The results are shown in Table 1.

【table】

[Table] Example 2 Acrylic polymer solution used in Example 1 and 25%
and a carbon black-containing polyurethane solution so as to have the polymer ratio shown in Table 2 to obtain a spinning dope. The spinning conditions were the same as in Example 1, and a 3-denier fiber was obtained. The results are shown in Table 2.

[Table] Example 3 An acrylic polymer with a molecular weight of 50,000 having a composition of acrylonitrile: methyl acrylate: sodium methallylsulfonate = 90.3:9.0:0.7 (%) was mixed with DMF.
Polymerization was carried out by solution polymerization, and after monomer recovery, an acrylic polymer solution with a polymer concentration of 23% and a water content of 2% was obtained. Polypropylene adipate with molecular weight 1500
Polymerize 150 parts of 1.4-butanediol, 27 parts of 1.4-butanediol, and 90.4 parts of MDI in 400 parts of DMF, and after the reaction is complete, dilute with DMF to obtain a polyurethane solution with a polymer concentration of 30% and a viscosity of 1200 poise at 25°C. Ta. The polyurethane solution was diluted to a polymer concentration of 15%, and 80 parts of conductive tin oxide particles with an average particle size of 0.05 μm were added to the solution per 100 parts of polyurethane, and thoroughly dispersed using a sand grinder. A polyurethane solution containing conductive tin oxide and an acrylic polymer solution are mixed into polyurethane/
The acrylic polymers were mixed at a weight ratio of 25/75 to obtain a spinning stock solution. The spinning dope was spun using the spindle shown in Table 3 at various spinning draft values.
The coagulation bath was DMF:water = 54:46 (%) at 10°C.
After the spinning conditions, processing was carried out under the same conditions as in Example 1. The results are shown in Table 3. In addition, the specific conductivity of Exp21 without moist heat treatment after drying is 217.7.
Ω・cm, and a decrease in conductivity was observed.

【table】

Claims (1)

[Claims] 1. 50 to 90 parts of acrylic polymer and conductive fine particles
The conductive elastic polymer consists of 50 to 10 parts by weight of 10 to 50% by weight and 90 to 50% by weight of an elastic polymer that is miscible but incompatible with the acrylic polymer. A conductive acrylic synthetic fiber with a structure dispersed in discontinuous long and thin islands in the direction of the fiber axis. 2. The fiber according to claim 1, wherein the acrylic polymer contains 80% by weight or more of acrylonitrile. 3. The fiber according to claim 1, wherein the conductive fine particles are carbon black, metal, or metal oxide. 4. The fiber according to claim 1, wherein the conductive fine particles are tin oxide, zinc oxide, and titanium oxide coated with tin oxide or zinc oxide. 5. The fiber according to claim 1, wherein the elastic polymer is polyurethane. 6 Acrylic polymer solution and conductive fine particles 10~
(acrylic polymer) /
(Conductive elastic polymer) = 50/50 to 90/10 (weight ratio)
A method for producing conductive acrylic synthetic fibers, which comprises mixing the fibers in a coagulation bath, spinning them into a coagulation bath at a spinning draft of 0.2 to 2.0, washing them with water, drying them, and then shrinking them under moist heat. 7. The method according to claim 6, wherein the acrylic polymer contains 80% by weight or more of acrylonitrile. 8. The method according to claim 6, wherein the conductive fine particles are carbon black, metal, or metal oxide. 9. The method according to claim 6, wherein the conductive fine particles are tin oxide, zinc oxide, and titanium oxide coated with tin oxide or zinc oxide. 10. The method according to claim 6, wherein the elastic polymer is polyurethane. 11. The method according to claim 6, wherein the spinning draft is 0.3 to 1.5. 12. The method according to claim 6, wherein the spinning and drawing is carried out at 95°C or lower. 13. The method according to claim 6, wherein the spinning and drawing is performed 3 to 7 times.