JP2013181251A - Antistatic fiber excellent in whiteness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antistatic fiber excellent in whiteness that exhibits a high antistatic performance irrespective of the ambient humidity.SOLUTION: The core-sheath combined filament yarn is an antistatic fiber including a filament A1 containing 1-40 wt.% of a conductive material as a core part and a filament B2 having a fiber diameter of 10-1000 nm as a sheath part. In a fiber cross section, a thickness 3 of a sheath yarn layer composed of the filament B2 is 3-500 times of a fiber diameter of the filament B2. It is preferable that the conductive material which the filament A1 contains is conductive carbon black.

Description

The present invention provides an antistatic fiber excellent in whiteness that exhibits high antistatic performance regardless of environmental humidity.

  Synthetic fibers using thermoplastic polymers such as polyester and polyamide are excellent in mechanical properties and dimensional stability, so they are widely used not only for clothing but also for interior and vehicle interiors, industrial applications, medical and sanitary materials, Industrial value is extremely high. However, these synthetic fibers are inherently extremely high in electrical resistance, so that static electricity is easily charged by friction. In clothing, discomfort and dirt (such as allergens) when attaching and detaching, especially in work clothes, combustible due to discharge. There are problems such as the danger of ignition to gas and damage to precision instruments. In addition, with the diversification of fiber applications, the demand for antistatic fibers (antistatic fibers) that prevent static electricity failures is increasing day by day, and not only improvements in conventional antistatic performance, but also design and comfort. There is a need for multiple functions.

  For example, in hospital lab coats and nursing uniforms, anti-static properties are required to prevent malfunctions and breakdowns of medical devices, but at the same time, fashionability, ease of movement, and comfort are also required, resulting in a texture. The use of soft extra-fine yarn is progressing. However, as the fiber becomes thinner, the specific surface area of the fiber increases, so the amount of static electricity generated by friction increases, and the fabric is charged more seriously. There is also a method to prevent electrification by mixing the conductive yarn into the fabric at a high mixing ratio in order to prevent electrification, but generally the conductive yarn exhibits a gray to black color. Can't stand the use of

  As a more familiar need, there is an example of an antistatic capacity type touch panel such as a mobile phone or a smart phone which has been popularized recently. Since this type of touch panel detects a change in capacitance when a finger touches the surface, it cannot be operated via an insulating material such as a glove. Although the operation itself can be performed by knitting the conductive yarn on the surface of the glove, the fashionability is severely limited as described above. For this reason, any color antistatic yarn that exhibits excellent antistatic performance even at low temperatures and low humidity in winter and can be used as a fabric surface has been awaited.

  Furthermore, in wiping cloth and hard disk polishing cloth applications that use ultra-fine fibers, a static elimination function is being required to prevent re-adhesion of dust and dirt after wiping. Sufficient effects could not be obtained, and it was difficult to produce ultrafine yarns with conductive yarns using conductive particles.

  As a method for imparting antistatic properties to the synthetic fiber, a method of blending a base polymer that forms the fiber and a hydrophilic polymer that is substantially incompatible has been proposed. For example, when the base polymer is polyester, such as polyoxyalkylene glycol, polyoxyalkylene glycol / polyamide block copolymer, polyoxyalkylene glycol / polyester block copolymer or polyoxyalkylene glycol / polyester / polyamide block copolymer, etc. A method of mixing a polyoxyalkylene compound and a method of adding an organic or inorganic ionic compound to these are known (Patent Documents 1 to 3).

  However, since all of these methods are mainly ionic conduction, there is a drawback that the intervening effect of water molecules in the fiber is large, and the antistatic effect decreases rapidly in a low humidity environment. Furthermore, since the base polymer is kneaded with an incompatible antistatic agent, ultrafine yarn having a small fiber diameter (fiber diameter 6 to 10 μm), ultrafine yarn (fiber diameter 2 to 6 μm), nanofiber (fiber diameter) Application to 10 to 1000 nm) has a problem that the strength is remarkably lowered.

  On the other hand, as a method of imparting antistatic performance without being influenced by environmental humidity, conductive fibers obtained by dispersing conductive carbon black or the like in fibers at a high concentration are used as a fabric together with nonconductive fibers. A method for obtaining antistatic properties has been proposed (Patent Document 4). However, since the fiber containing carbon black exhibits a black color, there is a drawback that even if a small amount is added, the appearance of the fiber product is remarkably impaired. This is a core-sheath structure in which the conductive component is the core and the protective component (non-conductive component) is the sheath, and a hollow portion is formed in the sheath component, or between the core component and the sheath component. This can be solved to some extent by interposing a polymer layer having a refractive index lower than that of the sheath component (Patent Documents 5 to 7). However, in such a method, since the conductive component is not exposed on the fiber surface, the antistatic property is inferior.

  As a method for improving the color tone of the conductive composite fiber in which the conductive component is exposed on the fiber surface, a method of mixing a white pigment such as titanium oxide with the protective component has been proposed and put into practical use (Patent Document 8). In order to obtain sufficient whiteness, white pigments must be mixed at a high mixing ratio (for example, about 10% by weight). For this reason, spinning nozzles, guides, twisted traveler, heaters, knitting needles, etc. In the weaving and knitting process, the metal part in contact with the fiber is significantly worn, and its production is difficult.

  Further, in order to solve these problems, for example, a white conductive metal compound represented by particles coated with tin oxide doped with antimony oxide on titanium oxide is dispersed at a high concentration in the fiber, and a fiber such as polyester is formed. A method of obtaining white conductive fibers by composite spinning together with a thermoplastic resin has been proposed (Patent Document 9). However, since these fibers use a large amount of an expensive white conductive metal compound, there is a problem that not only the production cost is high, but also the yarn-making property is extremely poor.

  For this reason, there has been a strong demand for development of antistatic fibers that exhibit high antistatic performance regardless of environmental humidity and that are excellent in whiteness that can be used as a fabric surface.

Japanese Patent Publication No.55-122020 (Claims) JP-A-60-134024 (Claims) JP 2010-18927 A (Claims) Japanese Patent Laid-Open No. 60-224813 (Claims) JP-A-56-20614 (Claims) JP 2011-236530 A (Claims) JP 58-163726 (Claims) JP-A-57-5924 (Claims) Japanese Patent Laid-Open No. 3-241067 (Claims)

  The present invention provides an antistatic fiber that exhibits high antistatic performance regardless of environmental humidity and has excellent whiteness that can be used as a fabric surface.

The above-mentioned subject is achieved by the following means.
(1) A core-sheath mixed yarn in which a filament A containing 1 to 40% by weight of a conductive substance is disposed in a core part, and a filament B having a fiber diameter of 10 to 1000 nm is disposed in a sheath part, The antistatic fiber, wherein the sheath yarn layer thickness of the filament B is 3 to 500 times the filament B fiber diameter.
(2) The antistatic fiber according to (1), wherein the conductive material contained in the filament A is conductive carbon black.
(3) The antistatic fiber according to (1) or (2), wherein a specific resistance value at a temperature of 10 ° C. and a humidity of 15% is 1.0 × 10 ¹⁰ Ω · cm or less.
(4) The antistatic fiber according to any one of (1) to (3), wherein the whiteness of the fiber is 70 or more.
(5) The antistatic fiber according to any one of (1) to (4), wherein the sea-island composite yarn in which the filament A and the filament B are arranged as island components is obtained by sea removal treatment.

ADVANTAGE OF THE INVENTION According to this invention, while showing high antistatic performance irrespective of the humidity of the environment to be used, the antistatic yarn excellent in the design property and aesthetics excellent in whiteness is obtained.

The schematic diagram of an example of the antistatic fiber of this invention.

Hereinafter, the present invention will be described in detail together with preferred embodiments.
The antistatic fiber of the present invention is a core-sheath mixed yarn composed of filament A and filament B.
The polymer forming the filament A and / or the filament B is not particularly limited as long as it is a fiber-forming thermoplastic polymer, and examples thereof include polyester, polyamide, polyethylene, and polypropylene. Of these, polyester and polyamide are preferably used. More specifically, polyesters include, for example, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, those obtained by copolymerizing a dicarboxylic acid component, a diol component or an oxycarboxylic acid component, or a blend of these polyesters. It is done. Furthermore, aliphatic polyesters such as polylactic acid, polybutylene succinate and polyε-caprolactam known as biodegradable polyesters may be used. Examples of the polyamide include nylon 6, nylon 66, nylon 69, nylon 46, nylon 610, nylon 12, polymetaxylene adipamide, and those obtained by copolymerizing or blending these components.

  In the filament A used as the core yarn in the present invention, it is important to contain 1 to 40% by weight of a conductive substance. By containing 1% by weight or more of a conductive substance, excellent antistatic performance independent of environmental humidity is exhibited, and by making it 40% by weight or less, mechanical strength excellent in practical durability and manufacturing cost reduction Can be achieved. Preferably it is 5-35 weight%, More preferably, it is 10-30 weight%.

Here, the conductive substance is not particularly limited as long as the specific resistance in a powder state is about 10 ⁴ Ω · cm or less, and examples thereof include known conductive carbon black, conductive metal compounds, and the like. Things can be used. Examples of the carbon black include acetylene black, oil furnace black, thermal black, channel black, and ketjen black. On the other hand, examples of the conductive metal compound include metal powder, metal sulfides such as copper sulfide, zinc sulfide, and cadmium sulfide, metal halides such as copper iodide, tin oxide, copper oxide, silver oxide, zinc oxide, and cadmium oxide. In addition, metal oxides such as indium oxide, zirconium oxide, tungsten oxide, and lead oxide can be used. Further, these metal compounds include semiconductors that do not exhibit sufficient conductivity, but the conductivity can be improved by adding a small amount of an appropriate second component (doping agent). Examples of the doping agent include oxides of different metals and the same or different metals. Specifically, there is a method of adding antimony oxide to tin oxide, copper to copper oxide, and aluminum oxide to zinc oxide. In particular, conductive metal compound fine particles in which the surface of a metal oxide having good whiteness such as titanium oxide or potassium titanate is covered with a conductive film containing tin oxide or zinc oxide as a main component and antimony oxide as a doping agent. Etc. are preferable because both whiteness and conductivity are good.

As will be described in detail later, in the antistatic fiber of the present invention, the whiteness of the filament A itself as the core yarn is obtained in order to obtain excellent whiteness by arranging the filament B having a specific fiber diameter in the sheath yarn. Is not important. That is, an expensive white conductive material is not required, and conductive carbon black that is less expensive and easily finely dispersed in the base polymer can be most suitably used.
The filament A may be a known conductive yarn, but a surface exposed structure in which the conductive component is exposed on the filament surface is preferable because the antistatic performance is increased. Furthermore, if the filament A is a microfiber (fiber diameter 2 to 6 μm) or nanofiber (fiber diameter 10 to 1000 nm) consisting only of a base polymer and a conductive material, the specific surface area will increase dramatically, so extremely high antistatic You can gain performance.

  Next, the filament B disposed on the sheath yarn will be described. The fiber diameter of the filament B needs to be in the range of 10 to 1000 nm. By setting it as this range, the fiber diameter becomes the wavelength range of visible light, light scattering on the filament surface becomes obvious, and excellent whiteness can be obtained by a kind of halation effect. A more preferable fiber diameter range is 50 to 900 nm, and even more preferably 100 to 800 nm. Moreover, if the cross-sectional shape of the filament B is a polygonal shape such as a triangle or pentagon, a flat cross-sectional shape, or a deformed cross-sectional shape having a concave portion such as a Y cross-section, light scattering is further promoted, so that extremely excellent whiteness can be obtained. This is preferable.

  It is important that the thickness of the sheath yarn layer by the filament B in the fiber cross section is 3 to 500 times as large as the fiber diameter of the filament B. By setting the sheath layer thickness to 3 times or more, it is possible to block the core yarn and to obtain excellent whiteness independent of the color of the filament A. Although the detailed mechanism is being elucidated, in addition to the above-mentioned light scattering effect on the filament surface, the light refraction in the nanoscale gap formed between the filaments and filaments is achieved by making the nano-sized filament B into a multilayer structure. Contributes effectively, and it is considered that excellent image shielding and whiteness can be obtained even when the sheath layer is thin. When the sheath layer thickness is more preferably 4 times or more, and even more preferably 5 times or more, a fiber with improved whiteness can be obtained.

On the other hand, in order to obtain excellent antistatic performance, it is important that the sheath layer thickness is 500 times or less, preferably 400 times or less, and more preferably 300 times or less. By setting the sheath layer thickness within this range, charging and discharging as a mixed yarn can be balanced, and excellent antistatic control that does not depend on the environmental humidity of 1.0 × 10 ^{5 to} 1.0 × 10 ¹⁰ Ω · cm. You can gain sex. The sheath layer thickness can be arbitrarily designed according to the intended use application and the required antistatic level. For applications that require high antistatic levels such as uniforms for handling precision electronic equipment, the sheath layer thickness can be designed to be small. Even under low temperature and low humidity, performance comparable to that of conductive yarn can be obtained. In the antistatic performance, the specific resistance value at a temperature of 10 ° C. and a humidity of 15% is preferably 1.0 × 10 ¹⁰ Ω · cm or less, more preferably 1.0 × 10 ⁹ Ω · cm or less, and still more preferably. Is 1.0 × 10 ⁸ Ω · cm or less.

  On the other hand, the filament B used for the antistatic fiber of the present invention may contain a functional agent such as a flame retardant, a heat-resistant agent, a weathering agent, etc., but a large amount of matting agent or pigment for the purpose of obtaining whiteness. No addition is necessary. This is because sufficient whiteness can be obtained by the light scattering effect as described above, and when it is desired to obtain a matte feeling, a sufficient effect can be obtained with addition of only 1% by weight or less. On the contrary, these functional agents and complementary color agents tend to form coarse particles in the filament B due to particle aggregation, so that the fiber toughness is easily lowered or the object is easily soiled by degreasing from the fibers (for example, In addition, it is preferable that the amount of addition be as small as possible.

  If the whiteness of the fiber is 70 or more, it has sufficient whiteness for general clothing. More preferably, it is 80 or more, and more preferably 85 or more, such as sports outerwear, ladies' innerwear, luxury fashion clothing, etc., which can be developed regardless of the application.

  As a method for producing the antistatic fiber of the present invention, (a) a method of covering the existing conductive yarn with nanofibers, and (b) a sea-island yarn having the filament B as an island component and the conductive yarn are core-sheathed. A method of obtaining seawater after mixing, (c) a method of obtaining sea-island composite yarn in which filament A and filament B are arranged as island components is proposed. From the viewpoint of uniformity of uniformity, the method (c) is excellent. On the other hand, when the existing conductive yarn is used in the method (a), if a fine fineness conductive yarn having a total fineness of about 15 to 44 dtex is used, the texture of the mixed yarn is extremely soft, and sports outerwear or Suitable for inner use. In addition, if a conductive yarn of about 44 to 110 dtex is used, an antistatic mixed yarn suitable for general clothing and the like having excellent flexibility and dimensional stability can be obtained. If a conductive yarn of about 110 to 300 dtex is used, An antistatic mixed yarn excellent in stiffness and mechanical strength and suitable for use in uniforms or industrial materials can be obtained.

  The antistatic fiber of the present invention will be specifically described below with reference to examples. About the Example and the comparative example, the following evaluation was performed.

(1) Intrinsic viscosity (IV)
Ηr of the definition formula is obtained by dissolving 0.8 g of a sample polymer in 10 mL of O-chlorophenol (OCP) having a purity of 98% or more, and obtaining the relative viscosity ηr by the following formula using an Ostwald viscometer at a temperature of 25 ° C. The intrinsic viscosity (IV) was calculated.
ηr = η / η0 = (t × d) / (t0 × d0)
Intrinsic viscosity (IV) = 0.0242 ηr + 0.2634
η: viscosity of polymer solution η0: viscosity of OCP t: drop time of solution (second)
d: density of the solution (g / cm ³ )
t0: OCP fall time (seconds)
d0: OCP density (g / cm ³ ).

(2) High elongation according to JIS L1013 (1999) Using TENSILON / UTM-III-100 manufactured by TOYO BALDWIN, strength at the filament breaking point (cN / dtex) under the measurement conditions of a sample length of 20 cm and a pulling speed of 20 cm / min. ), Elongation (%) was measured.

(3) The raw yarn specific resistance yarn is bundled to about 2200 dtex, using a weak anionic detergent, thoroughly refined to remove the oil agent, and then left for 24 hours at a temperature of 10 ° C. and a humidity of 15% RH. The specific resistance ρ (Ω · cm) of the raw yarn was determined by measuring the electrical resistance at both ends under the same temperature and humidity. A yarn having a raw yarn specific resistance of 1.0 × 10 ¹⁰ Ω · cm or less was accepted.

(4) Measurement of filament diameter and sheath layer thickness Fiber was embedded with epoxy resin, frozen with Reichert FC-4E cryosectioning system, and cut with Reichert-Nissei ultracut N (ultra microtome) equipped with a diamond knife. Thereafter, an observation image of the cut surface was taken with an H-7100FA transmission electron microscope (TEM) manufactured by Hitachi, Ltd. From this image, filament A and filament B were discriminated based on the image contrast and theoretical fiber diameter, and each fiber diameter was measured using image processing software (WINROOF). In addition, the fiber diameter of the filament B measured 50 selected at random, and calculated | required to the 10th place by rounding off the 1 nm place. Moreover, the sheath layer thickness defined the distance to the filament A located in the nearest place from the circumscribed circle of the yarn as the sheath layer thickness.

(5) Whiteness (W)
The fiber was wound on a metal plate, and L, a, and b values were measured twice using an SM color computer model SM-3 manufactured by Suga Test Instruments Co., Ltd., and the average value was obtained.
W = 100 − {(100−L) ² + (a ² + b ² )} ^1/2
(6) Sea removal treatment A tubular knitted fabric was prepared using a sea-island type composite yarn, and sea components were dissolved and removed with a 2 wt% sodium hydroxide aqueous solution heated at 80 ° C. After that, the cylinder was unwound and used as a sample.

Example 1
The method for obtaining the fiber of the present invention by sea-sealing the sea-island type composite yarn will be described below.
Polytrimethylene terephthalate (IV = 1.10) containing 33% by weight of conductive furnace carbon black as an island component that becomes filament A after sea removal treatment, and 0.1 wt% of titanium dioxide as an island component that becomes filament B Polyethylene terephthalate (IV = 0.71) was used, and an easily soluble alkali polyethylene terephthalate (IV = 0.55) containing 7.3 wt% of 5-sodium sulfoisophthalic acid as a copolymer component was used as a sea component polymer. These were melted separately at 285 ° C., weighed and poured into a spin pack. At this time, the weight composite ratio of each component is island A / island B / sea = 4/66/30, and the number of islands is island A / island B = 7/120. It was discharged. The yarn discharged from the die was cooled by an air cooling device, applied with an oil agent, wound at a speed of 1500 m / min, and wound as an undrawn yarn of 192 dtex-112 filament. In the microscopic observation of the undrawn yarn obtained by this process, the island component was not fused. Subsequently, the obtained undrawn fiber was drawn at a draw ratio of 2.56 times between rollers heated to 90 ° C. and 130 ° C. and wound at a speed of 800 m / min to obtain a drawn yarn of 75 dtex-112 filament. . The drawn yarn was used as a tubular knitted fabric, and the sea component was eluted with a 2% by weight sodium hydroxide aqueous solution heated to 80 ° C. to obtain a mixed yarn composed of filament A and filament B. As a result of TEM observation, the fiber diameter of the filament B was 510 nm, the sheath layer thickness was 2700 nm, and antistatic fibers excellent in specific resistance were obtained as shown in the table.

Examples 2 and 3
From the method described in Example 1, polytrimethylene ethylene terephthalate (IV = 1.10, Example 2) containing 20% by weight of conductive furnace carbon black as an island component polymer that becomes filament A after sea removal treatment. A mixed yarn was obtained according to Example 1 except that polyethylene terephthalate (IV = 0.66, Example 3) containing 8% by weight of conductive furnace carbon black was used. This mixed yarn was an antistatic fiber excellent in both whiteness and specific resistance.

Example 4
Example 1 except that the number of islands is changed to a base of island A / island B = 18/109 and the weight composite ratio of each component polymer is island A / island B / sea = 10/60/30. To obtain mixed yarn. An antistatic fiber having a good specific resistance value was obtained although it was white and yielded one step to Example 1.

Example 5
Control was performed in the same manner as in Example 4 except that the composite ratio of the sea components was reduced and the weight composite ratio of each component polymer was changed to Island A / Island B / Sea = 12/68/20 from the method described in Example 4. Electrical fibers were obtained. In this fiber, island A components, which are originally 18 islands, are fused together to form one thick filament A, and 109 filaments B are present so as to surround it. Although this mixed fiber was white and yielded one step to Example 1, it was an antistatic fiber having a good specific resistance value.

Example 6
Example 1 except that the number of islands is changed to a base of island A / island B = 1/126, and the weight composite ratio of each component polymer is island A / island B / sea = 1/69/30. To obtain a sea-island composite drawn yarn of 190 dtex-112 filament. The fiber obtained by seawater-removing the drawn yarn was an antistatic fiber excellent in whiteness although it was a step in Example 1 in specific resistance value.

Example 7
The fiber obtained in the same manner as in Example 1 was excessively seamed with a 4% by weight aqueous sodium hydroxide solution heated to 80 ° C. to a weight loss rate of 70%. The obtained mixed yarn was an antistatic fiber excellent in whiteness although it was transferred to Example 1 in terms of specific resistance value.

Example 8
In order to obtain a sea-island composite yarn that does not contain a conductive material, the island component is only polyethylene terephthalate (IV = 0.71) containing 0.1 wt% titanium dioxide, and the sea / island composite ratio is 30/70% by weight. Was made in the same manner as in Example 1 to obtain a sea-island composite yarn of 75 dtex-112 filament. Thereafter, a 28 dtex-3 filament nylon conductive yarn containing 1.8% by weight of conductive carbon black in the fiber is used as a core yarn, and the preceding sea-island composite yarn is covered with three pieces around the core and a sheath-core composite. I got a thread. Further, the core-sheath type composite yarn was subjected to sea removal treatment with a 4 wt% aqueous sodium hydroxide solution heated to 80 ° C. to obtain a desired mixed yarn. This mixed yarn was an antistatic fiber excellent in whiteness, although the specific resistance value was transferred to Example 1.

Example 9
Example 8 except that a nylon 6 / copolymerized PET polymer alloy fiber (Example 9) of 120 dtex-12 filament obtained by the method described in Example 1 of JP-A No. 2004-162244 was used as the sheath yarn. Similarly, a core-sheath type composite yarn in which three polymer alloy fibers were covered around a nylon conductive yarn was obtained. Next, the core-sheath type composite yarn was subjected to sea removal treatment with a 4 wt% sodium hydroxide aqueous solution heated to 80 ° C. to obtain a desired mixed yarn. This mixed yarn was an antistatic fiber excellent in whiteness, although the specific resistance value was transferred to Example 1.

Example 10
Except for using a nylon 6 / copolymerized PET polymer alloy fiber of 120 dtex-36 filament obtained by the method described in Example 38 of JP-A No. 2004-162244 as the sheath yarn, the same as in Example 8, A core-sheath type composite yarn in which three polymer alloy fibers were covered around a nylon conductive yarn was obtained. Next, the core-sheath type composite yarn was subjected to sea removal treatment with a 4 wt% sodium hydroxide aqueous solution heated to 80 ° C. to obtain a desired mixed yarn. This mixed yarn was an antistatic fiber excellent in whiteness, although the specific resistance value was transferred to Example 1.

Example 11
Example 1 except that polyethylene terephthalate (IV = 0.68) containing 11% by weight of conductive titanium oxide (Ishihara Sangyo Co., Ltd. “ET-300W”) is used as the island component that becomes filament A after sea removal treatment. In the same manner, a mixed yarn was obtained. This mixed yarn was an antistatic fiber excellent in both whiteness and specific resistance.

Example 12
Example 6 except that polyethylene island terephthalate (IV = 0.68) containing 11% by weight of conductive titanium oxide (Ishihara Sangyo Co., Ltd. “ET-300W”) is used as the island component that becomes filament A after sea removal treatment. In the same manner, a mixed yarn was obtained. This mixed yarn was an antistatic fiber excellent in both whiteness and specific resistance.

Comparative Example 1
A mixed yarn is obtained in the same manner as in Example 1 except that the island component polymer that becomes the filament A after the sea removal treatment is polyethylene terephthalate (IV 0.66) containing 0.5% by weight of conductive furnace carbon black. It was. This mixed yarn had a high specific resistance and was at a level where it could not be used as an antistatic fiber.

Comparative Example 2
Polyethylene terephthalate (IV = 0.71) containing 0.1% by weight of titanium dioxide as an island component and polyethylene terephthalate (IV = IV = IV = 0.71) containing 7.3 wt% of 5-sodium sulfoisophthalic acid as a copolymer component as a sea component. 0.55), three conductive islands (33 dtex-36 filaments) for microfibers having 8 islands and a sea / island composite ratio of 30/70% by weight were treated in the same manner as in Example 8. Was covered around a 28 dtex-3 filament nylon conductive yarn containing 1.8% by weight in the fiber. The mixed yarn obtained by desealing the core-sheath type composite yarn with a 4% by weight aqueous sodium hydroxide solution heated to 80 ° C. is inferior in whiteness although it has a good specific resistance value. It was a level that could not be used for the outer material.

Comparative Example 3
In Example 8, a mixed yarn was obtained in the same manner as in Example 8 except that the number of covering yarns was one. Although this mixed yarn had a good specific resistance value, it was inferior in whiteness and could not be used for a general clothing surface.

Comparative Example 4
The sea-island composite yarn containing the conductive material of 75 dtex-112 filament obtained in Example 1 is used as the core yarn, and the periphery thereof is 10 sea-island composite yarns of 75 dtex-112 filament not containing the conductive material obtained in Example 8. A core-sheath type composite yarn was obtained by covering with, and a mixed fiber was obtained by sea removal treatment. This mixed yarn had a high specific resistance and could not be used as an antistatic fiber.

Comparative Example 5
Although yarn was tried in the same manner as in Example 1 except that polytrimethylene terephthalate (IV = 1.10) containing 50% by weight of conductive furnace carbon black was used as an island component to become filament A after sea removal treatment, Due to the coarse particles due to the aggregation of the conductive agent, yarn breakage frequently occurred in the drawing process. A blended yarn obtained by subjecting a stretched yarn of 75 dtex-112 filament barely obtained to sea removal treatment in the same manner as in Example 1 had shading in the longitudinal direction and was inferior in whiteness.

1 Filament A
2 Filament B
3 Sheath layer thickness

Claims (5)

A core-sheath mixed yarn in which a filament A containing 1 to 40% by weight of a conductive substance is disposed in a core part and a filament B having a fiber diameter of 10 to 1000 nm is disposed in a sheath part. An antistatic fiber having a sheath yarn layer thickness of 3 to 500 times the filament B fiber diameter. 2. The antistatic fiber according to claim 1, wherein the conductive material contained in the filament A is conductive carbon black. 3. The antistatic fiber according to claim 1, wherein the specific resistance value at a temperature of 10 ° C. and a humidity of 15% is 1.0 × 10 ¹⁰ Ω · cm or less. The antistatic fiber according to any one of claims 1 to 3, wherein the whiteness of the fiber is 70 or more. 5. The antistatic fiber according to claim 1, wherein the antistatic fiber is obtained by performing sea removal treatment on a sea-island composite yarn in which the filament A and the filament B are arranged as island components.