JP2006104588A - Electroconductive acrylic fiber and method for producing electroconductive acrylic fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an electroconductive acrylic fiber having an excellent electroconductivity and excellent whiteness by a wet spinning method in a higher productivity stably. <P>SOLUTION: This method for producing the electroconductive acrylic fiber consisting of an acrylic polymer as a main component and having a sheath core structure containing electroconductive fine particles in its core part is provided by using organic solvent solution dissolving the acrylic polymer with the organic solvent as a spinning stock solution of the sheath component and also organic solvent solution dissolving by mixing the electroconductive fine particles (A) and the acrylic polymer (B) so as to become 4-20 weight ratio of the (A)/(B) as the spinning solution of the core component, spinning by setting the viscosity of spinning stock solution of the sheath component as ≤300 poise, and setting the sheath core ratio so that the content the electroconductive fine particles contained in the electroconductive acrylic fiber becomes 5-15 wt.% by using a sheath core type spinneret, and then performing 30-50% thermal shrinkage treatment. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a conductive acrylic fiber that has excellent conductive performance and is suitably used for clothing and interior applications that require an antistatic effect and an electromagnetic shielding effect, and a method for producing the same.

  Conductive fibers are widely used for industrial and household purposes to eliminate static electricity, avoiding ignition and explosion caused by static electricity, preventing breakdown of electronic components, preventing cluttering of clothing, and remarkable in the low humidity period of winter It is an indispensable material for avoiding the occurrence of sparks caused by frictional electrification of clothing, mats and carpets.

  Conventionally, conductive fibers are produced and used in various fields by a method of compositing a conductive material on the fiber surface by post-processing, a method of using a conductive material on the fiber itself, a method of kneading the conductive material inside the fiber, etc. I came. For example, post-processing techniques include a method of embedding conductive fine particles such as carbon black, metal, and metal compounds in the fiber surface, and impregnating the fibers with metal compounds such as copper compounds and then chemically treating the conductive metal compounds inside the fibers or There are known a method of depositing on the surface layer, a method of immobilizing an ion conductive material such as a polyether compound and a polyether ester compound on the fiber surface layer by a method such as a chemical crosslinking method.

  As a method of using a conductive material for the fiber itself, for example, a method using a conductive organic polymer (polypyrrole or the like) made of metal fiber, carbon fiber, or π-electron conjugated system is known.

  As a method for kneading the conductive material into the fiber, a method in which conductive fine particles such as carbon black, metal, and metal compound are combined by a method such as blend spinning or composite spinning, or a polyether compound or a polyether ester compound is used. In addition, there are known ionic compounds, methods of compounding ion conductive materials such as polymers obtained by block polymerization or graft polymerization of these compounds by methods such as blend spinning or composite spinning.

  In the production of the conductive fibers as described above, for example, when using a conductive material such as carbon black, metal, metal compound, π electron conjugated polymer compound, even if these materials are used alone, or Whether embedded in the fiber surface or kneaded inside, a conductive fiber can be obtained. Further, by blending a small amount of the obtained conductive fibers with other general fibers and weaving or knitting, there is an advantage that good antistatic properties can be imparted to the fiber product. However, since these conductive materials are generally colored, there is a problem that, when used in light-colored products such as lab coats, there is a problem that the aesthetics are impaired, and the use of the fiber processed product is limited. It was.

  On the other hand, when producing conductive fibers using a polyether compound, a polyether ester compound, or an ion conductive material obtained by block polymerization or graft polymerization of these compounds, the ion conductive material is generally colorless. The fiber in which the ion conductive material is combined can be used for a wide range of applications. However, since such an ion conductive material is dependent on the movement of ions as an electric conduction mechanism, it is highly humidity dependent. It is necessary to increase the blend rate. As a result, there are disadvantages such as deterioration of the original properties of the fiber processed product, such as a decrease in dyeability, a decrease in dyeing fastness, and a cured texture.

  Under such circumstances, in order to obtain a white conductive fiber having no humidity dependency without impairing the original properties of the processed fiber product, a white conductive material is formed so that a continuous phase is formed. There has been a demand for a technique for combining the required minimum amount.

  In order to meet such demands, fine particles of conductive ceramics represented by tin oxide, zinc oxide, ITO (indium tin oxide), ATO (antimony tin oxide), etc., and these conductive ceramics are used. A method of kneading white conductive fine particles such as coated fine particles into fibers has been proposed.

For example, Patent Literature 1 and Patent Literature 2 disclose a method for producing a conductive core-sheath composite fiber by kneading the white conductive fine particles into the core part using core-sheath composite spinning. In particular, according to Patent Document 1, the volume content of the conductive fine particles contained in the core part, the area ratio of the core part to the sheath part, the cross-sectional area of the core part, and the thickness of the sheath part are set to predetermined values. Thus, the conductive acrylic fiber that has been subjected to core-sheath composite spinning has excellent conductivity, whiteness, and yarn strength, and can be used in a wide range of applications.
Japanese Patent No. 3227528 Japanese Patent No. 3289817

  However, in Patent Document 1 and Patent Document 2 described above, for example, an acrylic fiber having excellent conductivity and whiteness can be obtained by spinning a conductive fiber having a core-sheath structure by a dry spinning method. When using the spinning method, the organic solvent for dissolving acrylonitrile was limited to dimethylformaldehyde. On the other hand, when spinning by a wet spinning method, various solvents can be selected as the organic solvent for dissolving acrylonitrile depending on the desired fiber quality. However, the wet spinning method is less likely to exhibit conductive performance than the dry spinning method, and in order to obtain a desired conductive fiber by the wet spinning method, the core portion is used by using an eccentric core-sheath composite spinning nozzle. It was necessary to devise such as controlling the position and the thickness of the sheath with high accuracy.

  It is not clear why the wet spinning method is less conductive than the dry spinning method, but in the case of the dry spinning method, the fiber formation process occurs due to solvent removal and accompanying volume shrinkage. Tends to be dense. Therefore, it is easy to form a continuous layer of conductive fine particles when conductive fine particles are kneaded into the core portion by core-sheath composite spinning. On the other hand, in the case of the wet spinning method, since the solvent is removed after precipitation coagulation in the coagulation bath, voids are easily formed in the fiber compared to the dry spinning method, and it is difficult to form a continuous layer of conductive fine particles. Conceivable. That is, it is presumed that the difference in fiber formation process greatly affects the electrical conductivity of the fiber between the dry spinning method and the wet spinning method.

  In the case of the wet spinning method, since the spinning speed is slower than that of the dry spinning method, a multi-hole type spinning nozzle having several thousand holes to several tens of thousands of holes is usually used in order to ensure productivity. However, when the conductive acrylic fiber is produced by the wet spinning method using the eccentric core-sheath composite spinning nozzle as described above, a slight viscosity balance between the spinning solution of the core component and the spinning solution of the sheath component is obtained. Due to the change, exposure of the core portion to the sheath portion is likely to occur, and yarn breakage during spinning and abnormal dyeing of fibers may occur. Therefore, in order to stably produce the core-sheath acrylic fiber by the wet spinning method, it is necessary to adjust the number of holes of the spinning nozzle to about several hundreds at most, and the production conditions are very narrow. The region had to be controlled and spun. That is, it has been extremely difficult to stably produce conductive acrylic fibers having desired conductivity and whiteness by high wet spinning with high productivity.

  The present invention has been made in view of the above problems, and the object of the present invention is to stably produce conductive acrylic fibers having excellent conductivity and excellent whiteness with high productivity by a wet spinning method. It is to provide a manufacturing method that can be used.

  The inventors of the present invention have conducted extensive experiments and studies to stably produce conductive acrylic fibers by a wet spinning method. As a result, the weight ratio of conductive fine particles in the core portion, conductive fine particles contained in the acrylic fibers It was found that the conductive acrylic fiber may be produced by setting the weight ratio of the fiber, the shrinkage ratio of the heat shrink treatment performed after spinning, and the viscosity of the spinning solution of the sheath component to respective predetermined values. Completed. In addition, by the method of the present invention, a good conductive acrylic fiber can be produced even in the dry spinning method.

  For example, in the production of conventional conductive acrylic fibers, as described in Patent Document 1 above, the volume content of conductive fine particles contained in the core, the area ratio between the core and the sheath, the core The conductive acrylic fiber was manufactured by setting the parameters such as the cross-sectional area and the thickness of the sheath so as to be predetermined values.

  In contrast, according to the present invention, when conductive acrylic fibers are manufactured by a wet spinning method, conductive acrylic fibers are manufactured by setting parameters different from the conventional ones as described above to predetermined values. Is. By producing conductive acrylic fibers in this manner, a continuous layer of conductive fine particles in the core can be formed with a predetermined amount of conductive fine particles more stably than before. Thereby, it becomes possible to stably produce conductive acrylic fibers having excellent conductivity and excellent whiteness with high productivity by the wet spinning method.

  That is, the method for producing a conductive acrylic fiber according to the present invention is a method for producing a conductive acrylic fiber having a core-sheath structure containing an acrylic polymer as a main component and containing conductive fine particles in the core, An organic solvent solution obtained by dissolving a polymer in an organic solvent is used as a spinning stock solution of the sheath component, and the weight ratio (A) / (B) between the conductive fine particles (A) and the acrylic polymer (B) is 4 or more and 20 or less. An organic solvent solution mixed and dissolved in an organic solvent as above is used as the spinning solution for the core component, and the viscosity of the spinning solution for the sheath component is set to 300 poise or less, and the conductive material is formed using the core-sheath spinneret. Spinning was carried out by setting the ratio of the sheath part to the core part so that the content of the conductive fine particles contained in the conductive acrylic fiber was 5% by weight or more and 15% by weight or less, and then 30% or more and 50% or less. Heat shrink treatment And it forms the most important feature that it comprises a Ukoto. In particular, the method for producing a conductive acrylic fiber of the present invention can be suitably applied when the spinning is performed by a wet spinning method.

In the method for producing a conductive acrylic fiber according to the present invention, the acrylonitrile content of the acrylic polymer in the sheath portion of the core-sheath structure is preferably 50% by weight or more and 98% by weight or less. The fine particles are preferably titanium oxide or zinc oxide having a conductivity of 10 ⁻³ S / cm or more. Furthermore, in this case, it is preferable that the number of holes of the core-sheath type spinneret is 3000 or more.

  In the method for producing conductive acrylic fiber of the present invention, an organic solvent solution obtained by dissolving an acrylic polymer in an organic solvent is used as a spinning stock solution of the sheath component, and the conductive fine particles (A) and the acrylic polymer (B) are in a weight ratio. The organic solvent solution mixed in (A) / (B) so as to be 4 or more and 20 or less and dissolved in the organic solvent is used as the spinning solution for the core component, and the viscosity of the spinning solution for the sheath component is set to 300 poise or less. Then, spinning is performed using a core-sheath type spinneret in which the ratio of the sheath part to the core part is set so that the content of the conductive fine particles contained in the conductive acrylic fiber is 5% by weight or more and 15% by weight or less. After performing the thermal shrinkage treatment at a shrinkage rate of 30% or more and 50% or less, a continuous layer of conductive fine particles is stably formed on the core of the conductive acrylic fiber, and excellent conductivity and excellent Conductive acrylic with high whiteness The fibers stably with high productivity by a wet spinning method, moreover can be easily manufactured.

In the method for producing a conductive acrylic fiber of the present invention, the acrylonitrile content of the acrylic polymer in the sheath portion of the core-sheath structure is 50% by weight or more and 98% by weight or less. The conductive acrylic fiber has excellent characteristics. Furthermore, if the conductive fine particles contained in the core of the acrylic fiber have a conductivity of 10 ⁻³ S / cm or more, the conductivity of the acrylic fiber can be further increased. For example, titanium oxide or zinc oxide can be used as such conductive fine particles having an electric conductivity of 10 ⁻³ S / cm or more.

  Furthermore, the production method of the present invention can use a core-sheath type spinneret having a number of holes of 3000 or more when spinning with a core-sheath type spinneret, and thus the core-sheath having a number of holes of 3000 or more. By performing spinning with a mold spinneret, conductive acrylic fibers can be produced with very high productivity.

Below, suitable embodiment in the manufacturing method of the conductive acrylic fiber of this invention is described in detail.
In the method for producing a conductive acrylic fiber according to the present embodiment, a sheath component spinning dope and a core component spinning dope are first prepared. As the spinning solution for the sheath component, an organic solvent solution in which an acrylic polymer is dissolved in an organic solvent is prepared. As the spinning solution for the core component, the conductive fine particles (A) and the acrylic polymer (B) are added by weight. An organic solvent solution prepared by mixing so that the ratio (A) / (B) is 4 or more and 20 or less and dissolving in the organic solvent is prepared.

  In the present embodiment, the acrylic polymer used for the spinning solution of the sheath component and the core component is not particularly limited, and a general acrylic polymer used for the production of conventional acrylic fibers can be used. In particular, it is preferable to use a material that can easily exhibit heat shrinkage in the heat shrinkage treatment step after spinning described below. The relationship between the acrylic polymer composition and the thermal shrinkage due to relaxation depends on the monomer component to be copolymerized, but generally the smaller the acrylonitrile content in the polymer, the higher the heat shrinkability. . Therefore, it is desirable to appropriately adjust the acrylonitrile content in the spinning dope so that a predetermined heat shrinkage rate can be obtained in the subsequent heat shrink treatment process.

  In particular, for the spinning solution of the sheath component, it is preferable that the acrylonitrile content of the acrylic polymer is 50% by weight to 98% by weight, particularly 50% by weight to 95% by weight. If the acrylonitrile content is less than 50% by weight, the original characteristics of the acrylic fiber such as dyeing vividness and color developability are not effectively exhibited, and other physical properties such as thermal properties tend to be lowered. . In order to improve the solubility and dyeability of acrylonitrile, it is preferable to copolymerize acrylonitrile with an unsaturated monomer such as an acrylate ester.

  Therefore, the acrylonitrile content in the sheath is preferably 50% by weight or more and 98% by weight or less as described above by copolymerizing the unsaturated monomer. Without losing the properties it has, it can have excellent dyeing clarity, color development and thermal properties. In the present embodiment, the unsaturated monomer copolymerized with acrylonitrile is not particularly limited. For example, acrylic acid and acrylic acid esters, methacrylic acid and methacrylic acid esters, vinyl acetate, vinyl chloride, vinylidene chloride, and the like. Can be used.

  Further, in this case, in order to stably manufacture the acrylic fiber having a core-sheath structure without suppressing the core part from being exposed to the sheath part and causing yarn breakage during spinning, It is extremely important to control the viscosity of the sheath component, and the solid content concentration and temperature in the spinning component solution of the sheath component are important so that the viscosity of the spinning component solution of the sheath component is 300 poise or less, preferably 150 poise or less. is there.

  On the other hand, the spinning solution of the core component is mixed so that the weight ratio (A) / (B) of the conductive fine particles (A) and the acrylic polymer (B) is 4 or more and 20 or less as described above. Dissolve in organic solvent. By setting the value of the above weight ratio (A) / (B) to 4 or more, when a conductive acrylic fiber is produced, a continuous phase of conductive fine particles is stably formed in the acrylic fiber, and sufficient conductivity is achieved. Performance can be provided. On the other hand, if the weight ratio (A) / (B) exceeds 20, the dispersion of the conductive fine particles and the spinnability of the spinning dope will be reduced during spinning, and when the coagulated yarn is taken up. Or it becomes easy to generate | occur | produce the cutting | disconnection of a core part at the time of extending | stretching. For this reason, the spinnability is lowered and the conductive performance of the acrylic fiber is lowered.

At this time, it is preferable that the conductive fine particles contained in the core component spinning dope is a metal oxide having a high whiteness in which the electrical conductivity in a powder form is 10 ⁻³ S / cm or more. As such conductive fine particles, titanium oxide or zinc oxide can be suitably used. In addition, for example, titanium oxide whose surface is coated with tin oxide, indium oxide, tin oxide or zinc oxide can be used. it can. In order to further increase the conductivity, antimony oxide can be used in combination with tin oxide and indium oxide, and tin oxide, indium oxide, aluminum oxide, potassium oxide, germanium oxide, and the like can be used in combination with zinc oxide. In this case, the form of the conductive fine particles to be contained in the spinning dope is not particularly limited, but when the fine particles are granular, the average particle size is 3 μm or less. It is preferable from the viewpoint of stability.

  In addition, as for the organic solvent for adjusting each spinning stock solution of the sheath component and the core component, an organic solvent such as dimethylacetamide, dimethylformamide, dimethylsulfoxide can be preferably used, but is not particularly limited. Other organic solvents commonly used in acrylic fiber spinning can also be selected.

  In the present embodiment, there is no particular limitation on the solid content concentration and temperature of each spinning solution of the sheath component and the core component, but if the solid content concentration is too low, voids are likely to occur in the fiber after spinning. As a result, the physical properties of the fibers may be reduced, leading to a decrease in the conductive performance. Accordingly, the solid content concentration of the sheath component in the spinning dope is preferably 5% by weight or more, and the solid content concentration in the spinning solution of the core component is preferably 30% by weight or more.

  Next, in the spinning solution of the sheath component and the core component prepared as described above, the content of the conductive fine particles contained in the acrylic fiber using the core-sheath type spinneret is 5 wt% or more and 15 wt% or less. Thus, the ratio of the sheath part and the core part is set and spinning is performed by a wet spinning method. When spinning, if the content of conductive fine particles contained in the fiber is less than 5% by weight, the conductive fine particles provide less excellent conductive performance for acrylic fibers because there are few conductive fine particles. I can't. On the other hand, when the content of the conductive fine particles exceeds 15% by weight, the fiber whiteness is inferior when the conductive acrylic fiber is produced, so that the product application is limited.

  The wet spinning method can be carried out in the same manner as that generally used in the production of conventional acrylic fibers. For example, a sheath stock and a spinning solution of a core component are organically fed from a core-sheath spinneret. Spinning can be performed by discharging and solidifying into a coagulating liquid consisting of a solvent and water.

  At this time, as the core-sheath type spinneret, it is preferable to use a spinneret having a number of holes of 3000 or more, particularly 5000 or more. Thus, the core-sheath type spinneret having a number of holes of 3000 or more is used for spinning. By doing so, conductive acrylic fibers can be produced with very high productivity.

  The coagulated yarn obtained by the above wet spinning is then subjected to various treatments such as drawing, solvent removal, oiling, drying and densification, and then shrinks the coagulated yarn at a shrinkage rate of 30% to 50%. A heat shrinking process is performed. The treatment method and treatment conditions in each treatment such as stretching, solvent removal, oil agent application, and drying densification are not particularly limited, and can be appropriately changed as necessary. For example, the stretching treatment can be carried out with removal of solvent in hot water at 80 ° C. or higher, and considering the spinning stability and the physical properties of the resulting fiber, the stretching ratio is about 3 to 10 times. In particular, it is preferable to set 4 to 7 times.

  In addition, the heat shrinking process is a process that is performed in order to reduce the distance between the conductive fine particles in the core in order to impart excellent conductivity, and is very important. In this heat shrinkage treatment, when the shrinkage ratio of the acrylic fiber is less than 30%, the distance between the conductive fine particles cannot be sufficiently reduced, and the target excellent conductive performance cannot be provided. On the other hand, when the shrinkage rate is larger than 50%, the acrylic fiber is liable to be brittle, and there is a problem that the passing through the spinning process is lowered when the spinning process is performed thereafter.

  The heat shrink treatment may be performed in an atmosphere of either wet heat or dry heat, but it is preferable to perform the heat contraction under wet heat in consideration of the coloring of the fibers. Further, in this heat shrinkage treatment, the shrinkage rate of the acrylic fiber depends on the acrylonitrile content in the fiber and the draw ratio at the time of drawing after spinning. Therefore, it is preferable to appropriately set the treatment conditions for the heat shrink treatment in combination with the conditions such as the acrylonitrile content and the draw ratio so that the acrylic fibers can be shrunk at the predetermined shrinkage rate. For example, the acrylonitrile content in the spinning dope and the stretching treatment so that the shrinkage of the acrylic fiber is 30% or more and 50% or less by performing the heat shrinkage treatment at a treatment temperature of 150 ° C. or less, preferably 130 ° C. or less. Conditions etc. can be set appropriately.

  By manufacturing the conductive acrylic fiber by the wet spinning method as described above, for example, the core portion of the conductive acrylic fiber can be controlled without controlling the position of the core portion and the thickness of the sheath portion with high accuracy as in the prior art. In addition, a continuous layer of conductive fine particles can be stably formed, and conductive acrylic fibers having excellent conductivity and excellent whiteness can be easily and stably manufactured with high productivity.

  In addition, since the conductive acrylic fiber manufactured in this way has excellent conductivity and excellent whiteness, for example, a light-colored fiber processed product that requires an antistatic effect or an electromagnetic shielding effect. Can also be used, and can be applied to various applications. In particular, when a textile product is manufactured using such an acrylic fiber having excellent conductivity, it is possible to effectively remove static electricity by imparting excellent antistatic properties to the textile product. Easily achieve effects such as preventing clinging, avoiding ignition and explosion caused by static electricity, preventing failure of electronic components, and avoiding sparks caused by frictional electrification of clothes, mats, carpets, etc. Can do.

  In the above embodiment, the case where the conductive acrylic fiber is spun by the wet spinning method is mainly described. However, the present invention is not limited to this, and for example, the spinning can be performed by the dry spinning method. Thus, even in the case of spinning by the dry spinning method, the conductive acrylic fiber having excellent conductivity and excellent whiteness can be stably produced with high productivity as in the case of the wet spinning method. be able to.

  Hereinafter, as a more specific embodiment of the conductive acrylic fiber of the present invention, an example will be given and described in detail. In the examples, the evaluation of the core-sheath composite state, the measurement of the single fiber electric resistance value, and the measurement of the frictional voltage were performed by the following methods.

(Evaluation of core-sheath composite state)
The obtained conductive acrylic fiber was observed with an optical microscope, and the core-sheath composite state was confirmed. The core-sheath composite state of the conductive acrylic fiber was evaluated according to the following criteria.
○: Core-sheath composite rate is 90% or more ×: Core-sheath composite rate is less than 90%

(Measurement method of electrical resistance of single fiber)
The conductive acrylic fibers produced under the conditions of Examples 1 to 4 and Comparative Examples 1 to 7 shown below were accurately separated by 1 cm and adhered to metal terminals with silver paste (Dotite manufactured by Fujikura Kasei Co., Ltd.). A DC voltage of 1000 V was applied between the metal terminals in an atmosphere at a temperature of 20 ° C. and a relative humidity of 40 RH%, and the resistance value between the metal terminals was measured (SM-8210 manufactured by Toa Denpa Inc.).

(Measurement method of frictional voltage of knitted fabric)
A spun yarn is formed using conductive acrylic fibers manufactured under the conditions of Examples 1 to 4 and Comparative Examples 1 to 7 and commercially available acrylic fibers, and the spun yarn is used to produce a spun yarn as described in detail below. Knitted fabric. Then, based on the friction band voltage measurement method defined in JIS-L-1094-1980, the friction band voltage is measured in an atmosphere at a temperature of 20 ° C. and a relative humidity of 40 RH% using the obtained woven fabric. went.

(Examples 1-4 and Comparative Examples 1-9)
The following three spinning stock solutions (a1 to a3) were prepared as the spinning stock solution for the sheath component. First, an organic solvent solution in which an acrylic polymer composed of 91% by weight of acrylonitrile and 9% by weight of vinyl acetate is dissolved in dimethylacetamide so that the solid content concentration is 20% by weight is prepared as the spinning solution for the sheath component (a1). did. Moreover, an organic solvent solution in which an acrylic polymer composed of 94% by weight of acrylonitrile and 6% by weight of methyl acrylate is dissolved in dimethylacetamide so that the solid content concentration is 20% by weight is used as the spinning solution for the sheath component (a2). Produced. Furthermore, an organic solvent solution in which an acrylic polymer composed of 93% by weight of acrylonitrile and 7% by weight of vinyl acetate was dissolved in dimethylacetamide so that the solid content concentration was 25% by weight was prepared as the spinning solution for the sheath component (a3). did.

  On the other hand, an acrylic polymer composed of 93% by weight of acrylonitrile and 7% by weight of vinyl acetate and a conductive titanium oxide fine particle (ET-500W manufactured by Ishihara Sangyo Co., Ltd .: particle size 0.2 to 0.3 μm) , Conductivity 0.4 S / cm), dimethylacetamide, solid content concentration, and the weight ratio (A) / (B) between the conductive titanium oxide fine particles and the acrylic polymer are the values shown in Table 1 below. 4 types of spinning dope (b1 to b4) were obtained.

  The combination of the spinning stock solutions a1 to a3 of the three sheath components prepared above and the spinning stock solutions b1 to b4 of the four core components shown in Table 2 and the combinations of Examples 1 to 4 and Comparative Examples 1 to 9 shown in Table 2. Used to be. At that time, the spinning solution temperature was set so that the spinning solution of the sheath component during spinning had the viscosity shown in Table 2. These sheath component spinning stock solution and core component spinning stock solution are expressed by a core-sheath type spinneret having a pore number of 5000 and a pore diameter φ of 0.07 mm, so that the content of conductive titanium oxide fine particles in the fiber is expressed. The ratio of the core portion and the sheath portion was set so that the value shown in 2 was obtained, and the mixture was discharged into a dimethylacetamide aqueous solution at 40 ° C. and 55 wt% to be solidified.

  The obtained coagulated yarn was subjected to stretching in hot water at 95 ° C. (stretching ratio is 5 times), solvent removal, oiling, drying and densification, and then subjected to heat shrinkage under pressured steam 120. Conductive acrylic fibers having a single fiber fineness of 4.0 dtex were produced by heat shrinking at 0 ° C. In addition, the shrinkage rate of each acrylic fiber in this heat shrinkage treatment is shown in Table 2.

  Then, each obtained conductive acrylic fiber of Examples 1-4 and Comparative Examples 1-9 evaluated the core-sheath compound state by the method demonstrated above. Moreover, about each conductive acrylic fiber of Examples 1-4 and Comparative Examples 1-7 whose core-sheath compound state was favorable, by the measuring method of the electrical resistance value of the single fiber demonstrated above, single fiber electrical resistance The value was measured. Table 3 shows the evaluation results of the core-sheath composite state and the measurement results of the single fiber electric resistance value.

  Furthermore, each of the conductive acrylic fibers of Examples 1 to 4 and Comparative Examples 1 to 7 in which the core-sheath composite state was good, and a commercially available acrylic fiber having a single fiber fineness of 2.2 dtex (H815 manufactured by Mitsubishi Rayon Co., Ltd.) Are mixed to form weight ratios of 3/97, 5/95, and 10/90 to form spun yarn (OE spun, cotton count 1/20), and using the spun yarn obtained, 16 A gauze knitted fabric was prepared. Thereafter, the frictional voltage measurement described above was performed on each of the prepared woven fabrics. The result of the measurement of the frictional voltage is also shown in Table 3.

  As shown in Table 3, regarding Comparative Examples 8 and 9 in which the viscosity of the sheath spinning solution exceeded 300 poise, the core-sheath composite state of the acrylic fiber was very bad, and the fiber quality was inferior. On the other hand, the fiber products produced using the conductive acrylic fibers of Examples 1 to 4 have a frictional voltage of 3000 V or less, and it can be confirmed that they have excellent antistatic properties. In general, when the frictional voltage is 3000 V or less as in Examples 1 to 4, it is said that there is no discomfort that clings to clothes or cracks due to static electricity. Moreover, when the top knitted fabric produced using the conductive acrylic fiber of the said Examples 1-4 was observed visually, it was confirmed that any knitted fabric has the outstanding whiteness.

  The conductive acrylic fiber of the present invention can be suitably used for clothing and interior applications that require antistatic effects and electromagnetic shielding effects.

Claims (6)

  A production method for producing a conductive acrylic fiber having a core-sheath structure containing an acrylic polymer as a main component and containing conductive fine particles in a core, wherein an organic solvent solution obtained by dissolving an acrylic polymer in an organic solvent is used as a sheath component. An organic solvent solution prepared as a spinning dope and mixed in a weight ratio (A) / (B) between the conductive fine particles (A) and the acrylic polymer (B) of 4 to 20 and dissolved in the organic solvent. The core component spinning dope is set so that the sheath component spinning dope has a viscosity of 300 poise or less, and the content of the conductive fine particles contained in the conductive acrylic fiber using the core-sheath type spinneret is It is characterized by comprising performing a heat shrinkage treatment of 30% or more and 50% or less after spinning by setting the ratio of the sheath part and the core part to be 5% by weight or more and 15% by weight or less. Conductive acrylic Manufacturing method of Wei.   The method for producing a conductive acrylic fiber according to claim 1, comprising performing the spinning by a wet spinning method.   The method for producing conductive acrylic fibers according to claim 1 or 2, wherein the acrylonitrile content of the acrylic polymer in the sheath portion of the core-sheath structure is 50 wt% or more and 98 wt% or less. The method for producing a conductive acrylic fiber according to any one of claims 1 to 3, wherein the conductivity of the conductive fine particles is 10 ^-3 S / cm or more.   The method for producing a conductive acrylic fiber according to any one of claims 1 to 4, wherein the conductive fine particles include titanium oxide or zinc oxide.   The method for producing a conductive acrylic fiber according to any one of claims 1 to 5, wherein the number of holes in the core-sheath type spinneret is 3000 or more.