JP3132791B2 - Conductive composite fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conjugate fiber excellent in static elimination performance, and more particularly to a conductive fiber having excellent static elimination performance in fiber physical properties and wearing durability.

[0002]

2. Description of the Related Art Conventionally, various proposals have been made for fibers having excellent static elimination performance, that is, conductive fibers. For example, there is a method of plating a metal on the surface of a non-conductive fiber to impart conductivity, or a method of forming a conductive coating layer on the fiber surface by applying a resin in which carbon black is dispersed to the fiber surface. is there. However, these methods have a problem that the process of manufacturing the conductive fiber is complicated and involves technical difficulties. In addition, the conductive fibers obtained by these methods are easily reduced in conductivity due to chemical treatment in a scouring process for weaving and knitting, and external effects such as abrasion and repeated washing during use. There is also a problem such as escape from.

[0003] In addition, metal fibers such as steel fibers are known as having excellent static elimination performance. However, metal fibers are expensive and are hardly compatible with general organic materials, and poor spinning, weaving and dyeing finishing. There are various problems such as a problem in the process, a problem of disconnection or falling off due to washing during wearing, a problem of electric shock and spark due to electrical conductivity, and a problem of melting trouble of fabric.

For the purpose of solving these problems,
Various conductive fibers in which a conductive component made of a thermoplastic resin containing carbon black and a protective component made of a fiber-forming thermoplastic resin are joined have been proposed. However, since fibers containing carbon black are colored black or gray, their use in light-colored products that require whiteness, such as white coats, will impair aesthetics and lack the fashionability. The actual situation is limited.

[0005] In terms of aesthetics, recently, conductive fibers containing a white or colorless conductive metal oxide have been proposed, and the present inventors have also already filed Japanese Patent Application No. 63-13074.
No. 5 proposes a white conductive fiber excellent in actual wear durability, static elimination performance and the like. However, in fact, the conductive fibers containing carbon black are superior in terms of long-term practical durability.

[0006] A core-sheath type antistatic device using a thermoplastic resin containing carbon black for a core portion and a fiber-forming thermoplastic resin containing titanium oxide for a sheath portion to conceal the black color of the core portion. Conjugated fibers have also been proposed.
No. 31450). However, such fibers are still insufficient, although the chromaticity is somewhat reduced, and when the amount of titanium oxide contained in the sheath portion is increased to enhance the concealing property, the contact parts are worn in the twisting, weaving, and knitting processes. There is a problem.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a twisted yarn, weaving, and knitting without impairing the feeling by mixing with a product, and in particular, preventing a decrease in aesthetics due to mixing with a light-colored product. An object of the present invention is to obtain a conductive fiber which is excellent in process pass stability in a process, hardly deteriorates in static elimination performance when actually worn, and maintains static elimination performance for a long period of time.

[0008]

According to the present invention, the object is to provide a protective polymer layer (A) composed of a fiber-forming thermoplastic resin and a thermoplastic resin containing 10 to 80% by weight of inorganic fine particles. A composite fiber comprising a concealing polymer layer (B) and a conductive polymer layer (C) made of a polyamide resin containing 15 to 50% by weight of conductive carbon black, wherein the layer (B) is formed around the layer (C). Achieved by providing a conductive composite fiber having a fiber cross-section in which the layer (A) is located on the outer periphery thereof and having a composite ratio of each layer satisfying the following relational expressions (1) and (2) simultaneously. Is done. 0.11 ≦ y / x ≦ 1.82 (1) 0.35 ≦ z / (x + y) (2) (where x is the conductive polymer layer (C) in the fiber cross section)
The longest diameter of y is the concealed polymer layer (B) in the fiber cross section
Indicates the minimum thickness of the protective polymer layer (A) in the fiber cross section. )

In the conductive composite fiber of the present invention (hereinafter sometimes simply referred to as composite fiber), the fiber-forming thermoplastic resin constituting the protective polymer layer (A) has a melting point of 150 ° C. or higher. Any resin may be used as long as it has good properties, but the layer (A) is preferably a resin having excellent spinnability in order to maintain good processability during fiberization. Examples of such resins include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, and polyamide resins such as nylon 6, nylon 66, nylon 12, and meta-xylene diamine nylon.
In particular, a polyester in which 80 mol% or more of the structural unit is an ethylene terephthalate unit or a butylene terephthalate unit is preferable because the processability is remarkably improved.

[0010] The conductive conjugate fiber of the present invention contains 0.1 to 10% by weight in a fabric as in the case of other conductive fibers.
Used in the proportion of Naturally, the fabric is manufactured through a dyeing and finishing step, and the conductive polymer layer (C) containing a large amount of conductive carbon black is brittle and easily damaged by heat, chemicals, and the like during processing. In particular, a fabric mainly composed of polyethylene terephthalate cannot avoid a high-temperature dyeing / high-temperature setting step, and the conductive polymer layer (C) is greatly affected by such a step.
The same can be said to a greater or lesser extent when a protective polymer layer (A) is made of a resin which is liable to be damaged in this step, and in such a case, the function as the protective polymer layer (A) is reduced. Will decrease. In such a case, the strength of the conductive conjugate fiber is reduced, and the fiber is easily cut due to bending or the like at the time of wearing, or the conductive polymer layer (C) is dropped and deteriorated.

Therefore, when the resin constituting the protective polymer layer (A) is polyester, especially polyethylene terephthalate, the physical properties of the protective polymer layer (A) are maintained and the resin constituting the conductive polymer layer (C) is thermally deformed. Even with a polyamide having a low temperature, the conductive performance of the conductive conjugate fiber does not decrease. The resin constituting the protective polymer layer (A) may contain various additives such as a fluorescent whitening agent, a stabilizer, an ultraviolet ray inhibitor and a matting agent as long as the spinnability is not impaired.

In the conductive conjugate fiber of the present invention, the concealing polymer layer (B) is used for improving the coloring property of the conductive conjugate fiber by using conductive carbon black.
Examples of the inorganic fine particles contained in the concealing polymer layer (B) include white pigments such as titanium dioxide, zinc oxide, magnesium oxide, aluminum oxide, silicon dioxide, barium sulfate, calcium carbonate, sodium carbonate, talc, kaolin and the like. Fillers can be used, and these can be used alone or in combination of two or more. Titanium dioxide and / or zinc oxide are preferred in consideration of the hiding effect, the whiteness of the fabric, the spinnability, the workability, and the like.

The inorganic fine particles have an average particle size of 5 due to clogging of the filter at the time of spinning, deterioration of spinnability, breakage of yarn at the time of drawing, and the like.
It is preferably at most μ, particularly preferably at most 1 μ. The content of the inorganic fine particles in the concealing polymer layer (B) is 10 to 8
0% by weight, preferably 20 to 70% by weight. When the content of the inorganic fine particles is less than 10% by weight, the concealing effect on the conductive polymer layer (C) is insufficient. On the other hand, when the content exceeds 80% by weight, the flowability of the concealing polymer layer (B) decreases,
The fibrillation processability such as yarn breakage during spinning / drawing of the conjugate fiber deteriorates.

As the thermoplastic resin constituting the concealing polymer layer (B), nylon 6, nylon 66, nylon 1
2, polyamide resins such as nylon 4, nylon 11, and metaxylene diamine nylon; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyhexamethylene terephthalate; polyolefin resins such as polyethylene and polypropylene; SB
S (styrene-butadiene-styrene block copolymer), hydrogenated SBS, SIS (styrene-isoprene-styrene block copolymer), hydrogenated SIS, SI (styrene-isoprene block copolymer),
Polystyrene resins such as hydrogenated SI; and thermoplastic elastomers such as polyurethane thermoplastic elastomer, polyester thermoplastic elastomer, and polyamide thermoplastic elastomer. From the viewpoints of fluidity in the case of high content of inorganic fine particles, adhesion to the conductive polymer layer (C), heat resistance, and the like, polyamide resins and thermoplastic elastomers containing nylon 6 and nylon 66 as main components are preferred. These resins may contain various additives such as a fluorescent whitening agent and a stabilizer as long as the hiding effect is not impaired.

In the conductive composite fiber of the present invention, the conductive carbon black content in the conductive polymer layer (C) is 1
It is 5 to 50% by weight, preferably 20 to 40% by weight.
When the conductive carbon black content is less than 15% by weight, favorable conductivity cannot be obtained, and sufficient static elimination performance cannot be exhibited. On the other hand, when the content of the conductive carbon black exceeds 50% by weight, no further improvement in the conductivity is recognized, that is, the conductivity is saturated, and the fluidity of the layer (C) is remarkably reduced, and the spinning is performed. Sex deteriorates extremely.

The conductive carbon black contained in the conductive polymer layer (C) preferably has a specific resistance of 10 ⁻³ to 10 ⁻² Ω · cm, and is not limited to a specific type. When carbon black is completely dispersed in particles, the conductivity is generally poor, and when a chain structure called a structure is taken, the conductivity is improved and it becomes what is called a conductive carbon black. Are known. Therefore, when making the resin conductive with the conductive carbon black, it is important to disperse the resin in the resin without destroying the structure. The mixing and dispersion of the conductive carbon black into the resin can be performed by any known mixing method.However, when an excessive shear stress acts on the conductive carbon black, the above-described structure is broken and the conductivity is significantly reduced. Because there is
It must be done under conditions that avoid it.

As the electric conduction mechanism of the conductive carbon black-containing resin, a mechanism based on the contact of carbon black chains and a mechanism based on a tunnel effect are considered.
Generally, the former is considered main. Therefore, the longer the chain of carbon black and the higher the density of the carbon black in the resin, the higher the contact probability and the higher the conductivity. According to the study results of the present inventors, the conductive effect is hardly obtained when the conductive carbon black content is less than 15% by weight, the conductivity is sharply improved when the content is 20% by weight, and the conductive effect is substantially increased when the content exceeds 30% by weight. Reaches saturation.

The conductive carbon black is dispersed in a resin to exhibit conductivity, and it is important to obtain a conductive composite fiber containing the resin as one component. (1) Dispersing the conductive carbon black (2) Good dispersibility of carbon black in the conductive polymer layer and no abnormal filter clogging during spinning (3) Mechanical properties of conductive carbon black-containing resin Is good.

From the above viewpoint, the present inventors have studied by dispersing conductive carbon black in various resins.
A polyamide resin has been found to be optimal. Polyamide resin has a suitable polar group, so it has good compatibility and adhesion with conductive carbon black. It has both good properties and good fluidity. Also, the mechanical properties are extremely good, probably because the polyamide resin and the conductive carbon black are firmly adhered to each other.

When a polyester resin such as polyethylene terephthalate or polybutylene terephthalate is used in place of the polyamide resin, even if the content of conductive carbon black is small, the melt viscosity of the resin sharply increases and the fluidity is lost. A conductive polymer layer (C) having desired conductive performance and capable of forming fibers cannot be formed.

When a polyolefin resin such as polyethylene or polypropylene is used in place of the polyamide resin, the adhesiveness to the conductive carbon black is poor.
Because the mechanical properties of the conductive polymer layer (C) are considerably deteriorated, the conductive polymer layer (C) is cut in a short period of actual wearing, and the static elimination performance of the composite fiber is lost, and there is no durability for actual wearing.

As described above, the polyamide resin is most suitable as the resin constituting the conductive polymer layer (C) among the general-purpose resins. Examples of the polyamide resin include nylon 6, nylon 66, nylon 12, meta-xylene diamine nylon, and a resin containing these as a main component. These resins are conductive metal oxides such as titanium oxide coated with tin oxide in addition to conductive carbon black,
Known additives such as an antistatic improver such as polyalkylene glycol and polyalkylene ether may be contained.

The composite ratio of each layer in the fiber cross section of the conductive composite fiber of the present invention must satisfy the following relational expressions (1) and (2) at the same time. 0.11 ≦ y / x ≦ 1.82 (1) 0.35 ≦ z / (x + y) (2) (where x is the conductive polymer layer (C) in the fiber cross section)
The longest diameter of y is the concealed polymer layer (B) in the fiber cross section
Indicates the minimum thickness of the protective polymer layer (A) in the fiber cross section. If y / x is less than 0.11, the hiding effect is low even if the content of the inorganic fine particles in the hiding polymer layer (B) is increased, and it is difficult to improve the whiteness index of the conjugate fiber. On the other hand, y / x is 1.82
In the case where the ratio exceeds 2, the concealing effect of the concealing polymer layer (B) is improved, but the conductive performance and the fiberization processability are unfavorably reduced. If z / (x + y) is less than 0.35, the fiberization processability, particularly yarn breakage and fluff during spinning and stretching frequently occurs, and the processability is reduced. The upper limit of z / (x + y) is not particularly limited as long as conductivity can be exhibited. Preferred composite ratios are 0.20 ≦ y / x ≦ 1.50, 0.40 ≦ z /
(X + y), and a particularly preferred composite ratio is 0.30 ≦ y
/X≦1.00, 0.50 ≦ z / (x + y) ≦ 1.50
It is. Here, x indicates the longest diameter of the conductive polymer layer (C), and as described later, the shape of the conductive polymer layer (C) is often a circle, an ellipse, or a polygon. In the case of a circle or ellipse, it refers to the diameter and major axis, and in the case of a polygon, it refers to the longest of these, including sides and diagonals. Further, y represents the minimum thickness of the concealing polymer layer (B), which is the minimum thickness of the concealing polymer layer (B) formed by the outer periphery of the conductive polymer layer (C) and the outer periphery of the concealing polymer layer (B). Refers to the thickness. And z
Indicates the minimum thickness of the protective polymer layer (A), which is the minimum thickness of the protective polymer layer (A) formed by the outer periphery of the concealing polymer layer (B) and the outer periphery of the protective polymer layer (A). Point.

By appropriately selecting the amount of conductive carbon black, the amount of inorganic fine particles, and the composite ratio of each polymer layer in consideration of the fiberization processability, conductive performance, whiteness index, etc., 1
9 × 10 filament resistance at KV DC voltage
A conductive composite fiber having a whiteness index of 25 or less and ^-10 Ω / cm · f or less can be obtained.

In the composite shape of the conductive composite fiber of the present invention, the conductive polymer layer (C) and the concealing polymer layer (B) are continuous in the fiber length direction, and the conductive polymer layer (C)
And the protective polymer layer (A) on the outer periphery of the concealing polymer layer (B) and the outer periphery thereof. For example, a fiber having a core-in-sheath cross-sectional structure as shown in FIGS.
It is not limited to these, and the shape of the core sheath is circular,
Various types such as polygons are used. Further, the core-sheath type cross section can be not only concentrically arranged but also eccentrically arranged, and the sectional shape of the core is not limited to a circle but may be an ellipse, a polygon or the like. In particular, it is rather preferable that the core has irregularities and sharp corners in terms of static elimination performance. Similarly, the cross-sectional shape of the conjugate fiber may be circular or non-circular. Further, in the present invention, the conductive polymer layer (C) does not need to be completely covered by the concealing polymer layer (B), and the concealing polymer layer (B) is completely covered by the protective polymer layer (A). The concealing polymer layer (B) or the conductive polymer layer (C) may be exposed on the surface of the conjugate fiber as long as the whiteness index of the present invention is satisfied.

To produce the conductive conjugate fiber of the present invention,
A conventionally known composite fiber manufacturing method can be employed.
For example, normal spinning at a speed of 500 to 2500 m / min, followed by drawing and heat treatment, 1500 to 5000
Arbitrary production conditions are adopted, such as a method of spinning at a speed of m / min, followed by drawing and false twisting, a method of spinning at a high speed of 5000 m / min or more, and omitting the drawing step.

The conductive conjugate fiber of the present invention can take any form such as monofilament, multifilament, cut staple and the like.

[0028]

Since the conductive conjugate fiber of the present invention has excellent static elimination performance, it is neutralized by mixing 0.01 to 10% by weight with a material which is charged as it is, for example, a polyester cotton blended product, and the static elimination by static electricity. It can be trouble-free. In particular, since the static elimination performance does not decrease even after long-term use, repeated washing, and the like, it is extremely useful in fields where durable and static elimination performance is required, such as work clothes, dustproof clothing, and school uniforms. Further, it is used for various uses, for example, a jacket, formal, uniform, carpet, table mat, interior, curtain, copying machine, and the like. Further, despite the use of a large amount of conductive carbon black, it has high coloring properties and can be used in light-colored products.

[0029]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. In addition, each physical property and evaluation in an Example were calculated | required by the following method, and the result was shown to Table 1, Table 2, and Table 3.

(1) Filament resistance (Ω / cm ·
f): A sample fiber was cut into a length of 10 cm, and a conductive paint (doteite) was applied to the cut cross section to fix the fiber end.
The electrical resistance at an applied voltage of 1000 V was measured and calculated using the end as an electrode. (2) Charge amount (μ · Coulomb / m ² ): RISTSTR78 of the electrostatic safety guideline issued by the Ministry of Labor, Institute of Industrial Safety
-1. (2 in room of 22 ℃, 30% RH)
(Measurement after standing for 4 hours) (3) Whiteness index: Determined according to JISL1013B method. That is, a tubular knitted fabric of a sample is prepared, and it is folded into eight parts, and the reflectance at a wavelength of 450 nm and 550 nm with respect to a standard white plate is obtained using a spectrophotometer (type 307, manufactured by Hitachi). Calculated. Whiteness index = 4R ₁ -3R ₂ R ₁ : Reflectance at 450 nm R ₂ : Reflectance at 550 nm (4) Evaluation of fiberization processability: A rating (%) shown below
Was evaluated. ：: 50% or more ×: Less than 50% A rating = 100 × (number of bobbins without fluff and breakage) / (number of all bobbins) The total number of bobbins was obtained for 2 hours in a continuous operation for 2 hours. If the yarn breakage occurred during winding (less than 2 hours from the beginning of winding), the bobbin was switched to a new one at that point and winding was started. (5) Evaluation of static elimination performance: The distance between the charged sphere and the discharge sphere is set to 1
cm, and the charging sphere is charged using an electromotive machine to cause a discharge. The presence or absence of discharge when the sample was brought close to the charged sphere was observed. The discharge was stopped when the fibers of the present invention were brought close to each other. ：: Discharge stop ×: Discharge continuation (6) Comprehensive evaluation of color and performance: Whiteness index exceeds 40 and has durability. 白 Whiteness index is 25 to 40 and has durability. Less than 25, slightly inferior in durability △ Visually black, poor in durability × Extremely poor in durability, poor in fiberization process ××

Example 1 Nylon 6 containing 35% by weight of conductive carbon black was used as the conductive polymer layer (C), and titanium dioxide fine particles (average particle size 0.2
μ) was used, and polyethylene terephthalate containing 0.5% by weight of titanium dioxide was used as the protective polymer layer (A). Composite spinning was performed on a sheath type composite cross section (FIG. 1). Subsequently, drawing was performed to obtain a conductive composite fiber of 25 denier / 2 filaments. The whiteness index of the obtained composite fiber was 41.4, and the core resistance of the filament was 3 × 10 ⁷ Ω / cm · f. Further, the fiberization processability was good and there was no problem.

This composite fiber is air-blended with a polyester filament (polyethylene terephthalate) containing 0.5% by weight of titanium dioxide and having a whiteness index of 80.0 and having a denier of 30/24 filaments by a conventional method. ) / Cotton = 65/35 blended yarn, polyester (polyethylene terephthalate) / cotton = 65/35, cotton count 20S / 2
Into 80 warp yarns at a ratio of one warp yarn to obtain a 2/1 twill woven fabric of 80 warp yarns / inch and 50 weft yarns / inch. Next, dyeing finishing was performed under the conditions of a normal polyester cotton mixed fabric.

The concealing property of the conductive carbon black was good, and a fabric having excellent aesthetics was obtained. The charge amount of this woven fabric was 3.7 μ · Coulomb / m ² . After being worn for two years, during which about 500 washes were repeatedly performed, the charge amount was 3.8 μ · Coulomb / m ² . The product satisfies the standard value of the electrostatic safety guideline issued by the Industrial Safety Research Institute of the Ministry of Labor, 7 μ · Coulomb / m ² or less, and was excellent in static elimination performance and durability.

Examples 2 and 3 In Example 1, the content of titanium dioxide in the concealing polymer layer (B) was changed to 70% by weight (Example 2) and 30% by weight (Example 3), and the composite ratio in the fiber cross section was changed. A conjugate fiber was obtained in the same manner except that the ratio was as shown in Table 2, and then a woven fabric was produced. All were excellent in fiberization processability, aesthetics, static elimination performance, and durability.

Examples 4 and 5 Composite fibers were obtained in the same manner as in Example 1 except that nylon 6 (Example 4) and polybutylene terephthalate (Example 5) were used as the protective polymer layer (A). Was prepared. The fiber obtained in Example 4 was the same as in Example 1.
Although the static elimination performance was slightly inferior to the fibers obtained in the above, all were excellent in fiberization processability and aesthetics.

Examples 6 and 7 In Example 1, as the conductive polymer layer (C), nylon 6 containing 27% by weight of conductive carbon black (Example 6) and nylon 12 containing 27% by weight of conductive carbon black were used. A conjugate fiber was obtained in the same manner except that (Example 7) was used, and then a woven fabric was produced. All were excellent in fiberization processability, aesthetics, static elimination performance, and durability.

Examples 8 to 11 In Example 1, nylon 6 containing 30% by weight of zinc oxide (Example 8) and titanium dioxide / silicon dioxide (mixing ratio by weight of 7/3) were used as the concealing polymer layer (B). 50
Wt.% Nylon 6 (Example 9) and hydrogenated SIS containing 50 wt.% Titanium dioxide (Septon KL2
002 (manufactured by Kuraray Co., Ltd.) (Example 10), and a composite fiber was obtained in the same manner except that polyethylene containing 50% by weight of titanium dioxide (Example 11) was used, and then a woven fabric was produced. All were excellent in fiberization processability, aesthetics, static elimination performance, and durability.

Examples 12 to 15 In Example 1, hydrogenated SIS containing 70% by weight of titanium dioxide was used as the masking polymer layer (B) (Example 12), and hydrogenated SIS containing 10% by weight of titanium dioxide was used. (Example 13), using hydrogenated SIS containing 70% by weight of titanium dioxide (Example 14), and using polyethylene terephthalate containing 10% by weight of titanium dioxide (Example 15). A composite fiber was obtained in the same manner except that the composite ratio was adjusted, and then a woven fabric was produced. All were excellent in fiberization processability, aesthetics, static elimination performance, and durability.

Example 16 The procedure of Example 1 was repeated, except that the composite ratio in the fiber cross section was changed to the ratio shown in Table 2, and the composite fiber having the three-layer core-sheath type composite cross section shown in FIG. And then a woven fabric was produced. All were excellent in fiberization processability, aesthetics, static elimination performance, and durability.

Comparative Example 1 A composite fiber was obtained in the same manner as in Example 1 except that polyethylene containing 35% by weight of conductive carbon black was used as the conductive polymer layer (C), and then a woven fabric was produced. Although the fiberization processability and aesthetics of the composite fiber were good, the charge amount after actually wearing it for 2 years and repeatedly washing during that time was 11.0 μ · coulomb / m ² , satisfying the standard values. And the static elimination performance and the durability were extremely poor.

Comparative Example 2 A composite fiber was obtained in the same manner as in Example 1 except that nylon 6 containing 7% by weight of titanium dioxide was used as the concealing polymer layer (B) and the composite ratio was as shown in Table 2. .
The fiberization processability was good, but the whiteness index was 23.5, which was inferior in aesthetics.

Comparative Examples 3 and 4 In Example 6, nylon 6 containing 7% by weight of titanium dioxide was used as the concealing polymer layer (B) (Comparative Example 3), and nylon 6 containing 50% by weight of titanium dioxide was used. (Comparative Example 4) A composite fiber was obtained in the same manner except that the composite ratio was as shown in Table 2. The conjugate fiber obtained in Comparative Example 3 was poor in processability and aesthetics, in particular, due to the fiberization processability, particularly the occurrence of thread breakage during stretching. The conjugate fiber obtained in Comparative Example 4 had a whiteness index of 22.0, which was inferior in aesthetics.

Comparative Examples 5 and 6 Nylon 6 containing 35% by weight of conductive carbon black was used as the conductive polymer layer (C), and polyethylene terephthalate containing 15% by weight of titanium dioxide was used as the protective polymer layer (A) (Comparative Example) 5) Using polyethylene terephthalate containing 0.5% by weight of titanium dioxide (Comparative Example 6), a composite fiber having a core-in-sheath composite cross section was obtained at a composite ratio shown in Table 2. The composite fiber obtained in Comparative Example 5 was
The contact parts such as guides from the stretching step to weaving were severely worn, and the whiteness index was 21.5, which was inferior in aesthetics. The whiteness index of the composite fiber obtained in Comparative Example 6 was 4.7, and the aesthetics were extremely poor.

[0044]

[Table 1]

[Table 2]

[Table 3]

[0045]

The fabric having excellent static elimination performance can be obtained only by adding 0.01 to 10% by weight of the conductive conjugate fiber of the present invention to a non-conductive fiber such as polyethylene terephthalate, and after two years of actual use. , The static elimination performance does not decrease. In addition, although conductive carbon black is used, it can be mixed with light color products because it is white,
Excellent coloring properties.

[Brief description of the drawings]

FIG. 1 is an electron micrograph showing a fiber cross section of a core-sheath type structure according to the conjugate fiber of the present invention.

FIG. 2 is another preferred example of a fiber cross section according to the conjugate fiber of the present invention.

[Explanation of symbols]

 A: protective polymer layer B: concealed polymer layer C: conductive polymer layer

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masao Kawamoto 1621 Sazu, Kurashiki City, Okayama Prefecture Inside Kuraray Co., Ltd. Yoko Nakajima (56) References JP-A-3-130406 (JP, A) JP-A-58-19360 (JP, A) JP-A-57-199817 (JP, A) JP-A-55-128015 (JP, A A) JP-A-2-53915 (JP, A) JP-A-58-163725 (JP, A) JP-A-56-151370 (JP, U) JP-B-52-31450 (JP, B2) (58) Survey Field (Int.Cl. ⁷ , DB name) D01F 8/14 D01F 8/12

Claims (2)

(57) [Claims] 1. A protective polymer layer (A) composed of a fiber-forming thermoplastic resin, a concealing polymer layer (B) composed of a thermoplastic resin containing 10 to 80% by weight of inorganic fine particles, and 15 to 15% of a conductive carbon black. A composite fiber comprising a conductive polymer layer (C) made of a polyamide-based resin containing 50% by weight, wherein a layer (B) is provided around the layer (C) and a layer (A) is further provided around the layer (B). Have, and
A conductive composite fiber in which the composite ratio of each layer simultaneously satisfies the following relational expressions (1) and (2). 0.11 ≦ y / x ≦ 1.82 (1) 0.35 ≦ z / (x + y) (2) (where x is the conductive polymer layer (C) in the fiber cross section)
The longest diameter of y is the concealed polymer layer (B) in the fiber cross section
Indicates the minimum thickness of the protective polymer layer (A) in the fiber cross section. ) 2. The conductive conjugate fiber according to claim 1, wherein the filament resistance at a DC voltage of 1 KV is 9 × 10 ¹⁰ Ω / cm · f or less and the whiteness index is 25 or more.