JPH07102437A - Electrically-conductive combined filament yarn - Google Patents

Abstract

PURPOSE:To obtain electrically-conductive combined filament yarn having slight discoloration, mixable with other charging yarns, capable of providing a fiber product with excellent antistatic properties and wearing durability. CONSTITUTION:This electrically-conductive combined filament yarn comprises highly orientated undrawn electrically-conductive sheath-core conjugate yarn as side yarn and electrically non-conductive polyethylene terephthalate-based multifilament as core yarn wherein the side yarn has yarn length 0.5-15% longer than that of the core yarn and the mechanical properties of the core yarn are larger than those of the side yarn. The highly orientated undrawn electrically- conductive sheath-core conjugate yarn is composed of a PET-based or PBT- based polymer (A) as a sheath component and a polyamide-based thermoplastic polymer (B) containing an electrically-conductive substance constituted of an electrically-conductive metal oxide as a core component and has specific filament core resistance value, danger elongation and shrinkage percentage in hot water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite fiber having excellent static elimination performance, and more particularly to a mixed fiber using a white conductive fiber having excellent static elimination performance with excellent physical properties and wear durability.

[0002]

2. Description of the Related Art Various proposals have been made for conductive fibers which are excellent in static elimination performance. For example, there has been proposed a conductive fiber in which a conductive component made of a polymer containing carbon black and a protective component made of a fiber-forming polymer are joined. However, one of the drawbacks of conductive fibers with carbon black is that the fibers are colored black or gray. Therefore, the use is limited in reality.

As a method for improving this drawback, in recent years, conductive fibers containing a white or colorless conductive metal oxide as a conductive substance have been proposed. For example, in JP-A-57-6762 and JP-B-62-29526, a mixture of a conductive metal oxide and a thermoplastic polymer is used as a conductive layer to prepare a composite fiber with a fiber-forming polymer. In this case, a method has been proposed in which the composite yarn is prepared, drawn, and then the fiber is further heat-treated to restore the conductive layer. That is, when the thermoplastic polymer is used as the binder of the conductive metal oxide, the conductive layer is cut in the stretching step. As it is, it cannot serve as a conductive fiber because the electrical conductivity is lost. Binder of conductive metal oxide
Such a heat treatment is necessary when a thermoplastic polymer, particularly a thermoplastic polymer having high crystallinity, is used.

However, the conductive fibers obtained by the techniques described in the above publications have the drawback of poor production efficiency because a heat treatment step after stretching is essential. Also,
The conductive fiber also has a drawback that it lacks wear durability. The durability of the conductive fiber was evaluated by measuring the conductive fiber as 0.
A woven fabric in which 1 to 10% by weight is woven is worn for about one year, and it is judged whether or not antistatic performance is present at that time. The standard value of the amount of electrification in the Electrostatic Safety Guideline issued by the Labor Safety Research Institute of the Ministry of Labor is 7 μCoulomb / m ↑ 2, and it is necessary to be less than this value. The conventional white or colorless conductive composite fiber cannot satisfy the above-mentioned durability.

For example, when the thermoplastic polymer is polyethylene, practical durability is insufficient, and it is found out by the present inventors that it is not suitable for use in dangerous work such as work clothes. . When a crystalline thermoplastic polymer is used as the thermoplastic polymer, the resistance value of the filament immediately after the production of the conductive composite fiber is 9 × 10 ↑ 10.
Ω / cm · f or less, and it can satisfy the standard value of electrification of the woven fabric, but since the durability is poor, the antistatic performance of the woven fabric is deteriorated and it is difficult to use in practice.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a conductive mixed fiber which is less colored and can be used in combination with other electrostatically charged fibers to impart excellent static elimination performance and wear durability to textile products. To provide.

[0007]

Means for Solving the Problems The present invention is a mixed yarn having highly oriented undrawn conductive core-sheath composite fibers as side yarns and non-conductive polyethylene terephthalate multifilaments as core yarns. The side yarn is 0.5 to 15% longer than the core yarn, and the initial Young's modulus and total strength of the core yarn are both larger than the initial Young's modulus and total strength of the side yarn. In the filament yarn, the highly oriented unstretched conductive core-sheath composite fiber comprises a polyethylene terephthalate-based or polybutylene terephthalate-based polymer (A) as a sheath component and a conductive metal oxide. A polyamide-based thermoplastic polymer (B) containing a conductive material is used as a core component, and the filament core resistance is 9 × 10 ↑ 10Ω / at a DC voltage of 1 kV.
less than cm · f, danger elongation is 5% or more, and 100
The present invention relates to a conductive mixed yarn, which has a shrinkage rate of 20% or less in hot water of ℃.

The static elimination performance means the static elimination of electric charges of a charged object by non-contact, and the core resistance is 10 ↑ 11Ω / c.
In the case of a fiber having a conductivity of m · f or less, a non-uniform electric field is formed and static electricity is removed by corona discharge, but the core resistance is 10
↑ When it exceeds 11 Ω / cm · f, no discharge occurs due to corona discharge, and effective charge removal property is not exhibited.

The inventors of the present invention have found that the elongation of the fiber when the core resistance exceeds 10 ↑ 11Ω / cmf at a DC voltage of 1 KV in the process of elongation, that is, the elongation at the time of losing the static elimination performance (danger in the present invention The elongation) and the constituent components of the conductive core-sheath composite fiber, and the mixed fiber state of the conductive core-sheath composite fiber and other fibers were examined. As a result, as factors that greatly affect the practical durability, there is a thermoplastic polymer containing the dangerous elongation and the conductive material, and a mixed fiber state of the conductive core-sheath composite fiber and other fibers. I found it.

The conductive core-sheath composite fiber according to the present invention (which may be simply referred to as conductive fiber) has a core-sheath type composite structure composed of a core component containing a conductive substance and a sheath component. There is. The composite form of the core-sheath is concentric core-sheath type, eccentric core-sheath type,
A multi-core sheath type and the like can be mentioned. The eccentric core-sheath type is preferable from the viewpoint of the effect, but the concentric core-sheath type is preferable from the viewpoint of durability, and the eccentric core-sheath type can be used properly according to the application and the required performance. The conductive substance contained in the core component means fine particles of white or colorless metal oxide, or fine particles in which the surface of the metal oxide is covered with the inorganic fine particles as nuclei. Many metal oxides are semiconductors close to insulators and often do not show sufficient conductivity.
However, for example, antimony oxide for tin oxide, aluminum, potassium for zinc oxide, etc. are known as such conductivity enhancers (doping agents) that can provide those having sufficient conductivity. ing. The specific resistance of tin oxide having an average particle diameter of 0.1 μ is about 10 ↑ 3Ω · cm, but the specific resistance of the solid solution of antimony oxide and tin oxide is 1 to 1.
It is 10 Ω · cm, and the conductivity is enhanced. The proportion of antimony oxide in the solid solution is 0.01 to 0.10.
(Weight ratio) is necessary for overall performance. If the coating amount of antimony oxide is small, the conductivity is insufficient, and conversely, if it is large, the target white-based direction is moved away.

In the present invention, as the conductive substance, the above-mentioned coated zinc oxide and tin oxide are preferable because of their excellent conductivity and whiteness, but other metal oxides such as tungsten oxide, indium oxide, and oxide are preferable. Examples thereof include conductive metal oxides such as zirconium, metal fine particles such as titanium oxide and magnesium oxide, and inorganic compound fine particles such as silica, which are coated with the conductive metal oxide.

These conductive materials may be used alone or in combination of two or more. Further, it can be used in combination with a conductive substance other than metal oxide, such as metal or carbon black, within a range that does not impair the white color. It is preferable that the metal oxide fine particles as a conductive substance have a small particle diameter, and an average particle diameter of 1 μm or less, particularly 0.5 μm or less is preferably used.

The content of the conductive substance in the core component is 6
It is preferably from 0 to 75% by weight. When the content of the conductive substance is less than 60% by weight, it is difficult to obtain preferable conductivity and sufficient charge removing performance is not exhibited. On the other hand, when the content of the conductive substance exceeds 75% by weight, further improvement in conductivity is not recognized, the fluidity of the core component is remarkably reduced, and the spinnability is extremely deteriorated, and especially the filter- Pack life such as clogging is shortened and process stability is poor, which is not preferable.

The polymer constituting the core component of the conductive fiber is nylon 6, nylon 66, nylon 12, metaxylylenediamine nylon, or the like, or a thermoplastic polyamide polymer containing these as the main components. Moreover, the water content of the polyamide-based polymer during spinning is 100 to 1
It is preferably in the range of 200 ppm. When the water content in the polyamide during spinning deviates from this range,
The dangerous elongation of the conductive fiber does not become 5% or more, and it becomes difficult to eliminate the charge by corona discharge. Further, when the water content of the polyamide during spinning is extremely low at less than 100 ppm, the resin itself becomes brittle and the conductive structure tends to become unstable. On the other hand, the water content of polyamide during spinning is 1
If it exceeds 200 ppm, foaming, voids, etc. tend to occur,
Fine defects are likely to occur in the conductive layer.

Since the polyamide-based polymer has an appropriate polar group, it has good compatibility and adhesiveness with the metal oxide which is a conductive substance, and even if it is blended with a conductive substance at a high concentration, it has little fluidity. It is a polymer that does not decrease and has both high conductivity and good fluidity. Furthermore, since the metal oxide, which is a conductive substance, and the polyamide-based polymer have strong adhesiveness, the mechanical properties are also extremely good, and the conductive layer is not cut even after long-term actual wear, and the static elimination performance is improved. Never lose.

Further, in the conductive fiber according to the present invention, as described above, the core component is a thermoplastic polyamide polymer containing a conductive metal oxide which is a conductive substance, and the sheath component is polyethylene terephthalate. A polymer (PET-based polymer) or a polybutylene terephthalate-based polymer (PBT-based polymer) is used.
The PET-based polymer or the PBT-based polymer is characterized in that it is difficult to stretch with respect to tension, and further, it is difficult to spontaneously stretch after spinning as compared with other polymers such as polyamide. When the polymer is a spontaneously extending polymer,
As the time elapses, the core component gradually expands, and the conductive layer in the core component breaks and the conductive performance is lost. Further, when PET-based polymer or PBT-based polymer is used, remarkable processing durability and durability in actual wear can be obtained.

The PET-based polymer or PBT-based polymer is a polymer having an ethylene terephthalate unit or a butylene terephthalate unit as a main repeating unit, respectively, and other dicarboxylic acid components, A diol component or an oxycarboxylic acid component may be copolymerized. However, as the copolymerization ratio increases, the tensile resistance of the conductive fiber decreases, so it is preferable to lower the copolymerization ratio. Desirably, polyester in which 85 mol% or more of repeating units are ethylene terephthalate units or butylene terephthalate units is preferable. The intrinsic viscosity [η] is preferably 0.55 or more.

In the conductive fiber according to the present invention, the composite ratio of the core component and the sheath component is the former / the latter = 8/92 to 22 /.
It is preferably 78 (weight ratio), particularly preferably 10/90 to 20/80 (weight ratio). If the sheath component exceeds 92% by weight, it becomes difficult to spin a stable composite fiber having a core-sheath structure. On the other hand, if the sheath component is less than 78% by weight, the PET component or PBT polymer that is the sheath component is used. Even if-has a sufficient fiber-forming ability, the spinnability of the composite yarn is lowered, the physical properties of the fiber are extremely lowered, and the practicality is lost.

The conductive fiber is a PET-based polymer or PBT-based polymer having [η] = 0.55 or more, and a polyamide-based fiber which is dried to have a water content of 100 to 1200 ppm and contains a conductive substance. The polymer is obtained by melting the polymer in separate extruders and performing high-speed spinning using a composite spinning device.

The yarn after spinning thus obtained has 1
High orientation melt spinning is performed at a spinning speed of 3500 to 5000 m / min so that the hot water shrinkage rate (WSr) at 00 ° C. is 20% or less. Usually, the conductive fiber is used in a small amount in a cloth. At that time, if the WSr of the conductive fiber is extremely large as compared with the WSr of other fibers, troubles such as cutting of the conductive fiber are likely to occur when an external force is applied to the fabric, especially during actual wearing. This effect is great. Further, the risk elongation of the conductive fiber according to the present invention is 5% or more, and the core resistance is 9 × 10 ↑ 1 at a DC voltage of 1 kV.
It shows a value smaller than 0 Ω / cm · f and is excellent in static elimination performance.

What is important in the present invention is that the above-mentioned highly oriented undrawn conductive fibers serve as side yarns to form a mixed yarn. A non-conductive PET-based multifilament is used as the core yarn which is another component of the mixed fiber. Since the PET-based multifilament has a large elongation resistance to pulling and is excellent in processing durability and durability for actual wearing, the conductive fiber as the side yarn is subjected to excessive tensile stress and the conductive layer is broken. Can be prevented.

It is essential in the present invention that the non-conductive PET multifilament which is the core yarn has a shorter yarn length than the conductive fiber which is the side yarn. The degree is such that when the yarn length of the core yarn is 100%, the yarn length of the side yarn is 100.5 to
The range is 115%. The side thread length is 100.5%
If it is less than 100%, it is impossible to prevent tension from being applied to the side yarns, and the conductive performance is gradually impaired during actual wearing. On the other hand, if the yarn length of the side yarns exceeds 115%, the fabric surface during actual wearing is reduced. The electrically conductive fibers are projected to the surface, and the electrically conductive fibers are abraded and the electrically conductive performance is deteriorated. By making the yarn length of the conductive fiber longer than that of the non-conductive PET-based multifilament as described above, when tension is applied to the mixed fiber, excessive tension is applied to the conductive fiber, and as a result, the conductive layer is formed. It prevents the situation of breaking.

The initial Young's modulus and total breaking strength of the non-conductive PET type multifilament which is the core yarn may be higher than the initial Young's modulus and total breaking strength of the conductive fiber which is the side yarn, respectively. is necessary. When the conductive fiber is higher in either one or both of them, tension is applied to the conductive fiber and the conductive layer is broken, as in the above-described conditions. As a non-conductive PET-based multifilament satisfying such initial Young's modulus and total breaking strength, polyethylene terephthalate
Stretched fiber made of copolymerized polyester having ethylene or ethylene terephthalate unit as a main repeating unit or molten polyester is extruded from a nozzle to give 500-
A fiber wound at a speed of 4500 m / min and then drawn at a draw ratio of 1.2 to 5 times is preferably used.

The total breaking strength as used in the present invention means that the mixed fiber is divided into a core thread and a side thread. The core thread is the core thread, the side thread is the side thread, and the breaking strength of each whole yarn is Is obtained and is divided by the total fineness of the filaments forming the yarn.

There are no particular restrictions on the blending ratio of the conductive fibers and the non-conductive PET-based multifilaments, the respective fineness, the number of single fibers constituting the fibers, etc., and they can be selected arbitrarily according to the purpose of use. it can. The fineness of the conductive fiber yarn is preferably 50 denier or less, and particularly preferably 30 denier or less. 1-5 filaments, especially 1-2
This degree, that is, the fineness of the conductive fibers is preferably 2 to 25 denier. The fineness of the non-conductive PET-based multifilament is preferably 10 to 100 denier, especially 20 to 50 denier, and the number of constituent filaments is 5 or more,
Particularly, it is preferable that the number of filaments constituting the non-conductive PET multifilament is 10 or more, that is, 20 denier or less. In addition, it is preferable that the mixing ratio of the conductive fibers (threads) in the mixed fiber in which both are combined is 16 to 66% by weight.

The mixed yarn of the present invention can be prepared by a usual method. For example, non-conductive PET that becomes the core yarn
-Type multifilament and conductive fiber to be side yarns are sent to separate supply rollers to combine them, and then the yarn is subjected to fluid treatment by an air entanglement nozzle or a turbulent flow nozzle and both yarns are subjected to fluid treatment. A method is used in which the filaments are entangled and mixed, and the resulting mixed fiber is wound up. At that time, by making the surface velocity of the feeding roller of the conductive fiber which is the side yarn higher than the surface velocity of the feeding roller of the core yarn, it becomes possible to achieve the yarn length difference, and Due to the speed difference, the conductive fiber becomes the side yarn and the non-conductive PET-based multifilament becomes the core yarn.

As described above, it is preferable that the core yarn and the side yarn are entangled by blowing air or the like, because tension is applied to the conductive yarn which is the side yarn, and the entanglement number at that time is 0. The range of 0.5 to 5 pieces / inch is preferable. The number of entanglements can be easily derived by observing the spread of the mixed filament yarn floating on the water surface and counting the places where the yarn does not spread. The obtained mixed fiber may be heat-treated as necessary, and the heat treatment condition is preferably a relaxation heat treatment at a temperature in the range of 120 to 210 ° C and a length not more than a fixed length.

The mixed filament yarn of the present invention is made of other electrically-chargeable fibers such as silk, wool, cellulose acetate, polyamide,
Textile products such as woven fabrics, knitted fabrics, ropes, cords and carpets can be produced by mixing with various natural and synthetic fibers such as polyester, polyolefin, polyvinyl, polyacrylonitrile and the like. Usually, for the purpose of imparting static elimination performance,
The mixing ratio of the conductive fibers in the fiber product is 0.1 to 5% by weight, but it is 1 to 5% in order to impart excellent static elimination performance.
It can also be 50% by weight. For example, by inserting the mixed fiber of the present invention into a cloth used for work clothes or the like at a constant interval, usually about 3 mm to 5 cm, it is also excellent in repeated refraction, chaffing, pulling, etc. during actual wearing. It also has the advantage that the conductive performance is extremely unlikely to be impaired.

[0029]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Each physical property value in the examples was measured and calculated by the following methods. (1) Intrinsic viscosity of PET or PBT [η] (dl / g) It was measured at 30 ° C using a mixed solvent of phenol / tetrachloroethane (equal weight). (2) Relative viscosity of nylon 6 Using 1 g / 100 ml of 96% sodium sulfate solution,
It was measured at 30 ° C. (3) Dangerous elongation Using the measuring device described in JP-A-2-53915,
It measured by the same method. (4) Core resistance (Ω / cm · f) A conductive fiber is cut into a length of 10 cm, a conductive coating (dotite) is applied to the cut cross section to fix the fiber end, and then the end is an electrode. Was calculated by measuring the electric resistance at an applied voltage of 1 kV. (5) Amount of electrified charge (μ ・ Kuron / m ↑ 2) RIS, an electrostatic safety guideline issued by the National Institute of Industrial Safety, Ministry of Labor
The measurement was carried out by TR78-1 (measurement after leaving in a room at 22 ° C. and 30% RH for 24 hours). (6) Fiber strength (g / denier) and initial Young's modulus (g / denier) It was measured using Shimadzu Autograph 2000A manufactured by Shimadzu Corporation. (7) Difference in yarn length About 1 m is taken excluding the twist of the mixed yarn. Make a knot on both ends and measure its length (L ↓ 1). Next, separate the core yarn and the sheath yarn, being careful not to stretch the sheath yarn with the needle. The length (L ↓ 2) on the sheath yarn side is measured when the whole knot is divided from the knot. The yarn length difference L ↓ 0 was calculated by the following formula. L ↓ 0 = [(L ↓ 2-L ↓ 1) / L ↓ 1] × 100

Example 1 60 parts of titanium oxide particles (average particle size of 0.2 μm or less, referred to as W1) whose surface was coated with 15% by weight of stannic oxide (containing 2% by weight of antimony oxide) were nylon. 6
40 parts of the above chips were melt-mixed at 270 ° C. to obtain a conductive layer polymer having a volume resistivity of 9 × 10 ↑ 2Ω · cm. Then, the chips were vacuum dried at 80 ° C. to adjust the water content of the chips to 400 ppm. Then, with this chip, [η]
= 0.63 PET chips are melted in separate extruders, and a composite fiber spinning device is used so that the polyamide chips are the core part and the PET chips are the sheath part (core-sheath weight ratio = 13 : 87) was spun out from 4 discharge holes at 295 ° C., and was divided into two at a spinning speed of 4500 m / min and wound up,
A conductive core-sheath composite fiber of 25 denier / 2 filament was obtained. The core resistance of the obtained conductive core-sheath composite fiber is 5 × 10.
↑ 10Ω / cmf, danger elongation 15%, total strength 3.2g / denier, initial Young's modulus 74g / denier.
It was Le.

This highly oriented unstretched conductive core-sheath composite fiber 25
A mixed yarn was prepared by using Denier / 2 filament as a side yarn. That is, it is spun at a spinning speed of 1200 m / min and wound up, a hot roller of 78 ° C., a hot plate of 150 ° C.
The total strength was 5.0, which was stretched 3.5 times.
PE with g / denier and initial Young's modulus of 110 g / denier
T multifilament yarn 30 denier / 24 filament was prepared. The PET multifilament and the above-mentioned conductive fiber were fed from separate feed rollers at a speed of 55.5 m / min for the conductive fiber and at a speed of 54.0 m / min for the PET multifilament, to obtain both yarns. Was mixed with each other, and both yarns were entangled and mixed with each other using an air entanglement nozzle of 4.0 kg / cm ↑ 2, and the yarn was taken up by a take-up roller at a speed of 54.0 m / min and wound up. The number of entanglements of the obtained mixed fiber is 1.5 / inch, and the difference in yarn length between the core yarn and the side yarn is 2.5.
%Met.

When the mixed fiber was observed by an optical microscope, it was confirmed that the PET multifilament was located almost at the center of the mixed fiber, and the conductive fiber was incompletely wrapped around the conductive fiber. Was done.

This mixed fiber is PET / cotton = 65/35,
One of 80 warps / inch and 50 wefts / inch of warp yarn of 20s / ↓ 2 is struck at a rate of 1 out of 80 warps.
/ 2 twill fabric. Subsequently, dyeing and finishing were carried out under the condition of ordinary polyester blended cotton fabric. After wearing this fabric for 1 year and repeating washing about 250 times during that period, the electrified charge amount was 4.8 μ · coulon / m ↑ 2, and the core resistance was 6 × 10.
↑ It was 10 Ω / cm · f.

PET / cotton = 65/3 made of the above conductive fiber
Covered with a blended yarn of 5, PET / cotton = 65/3
5. A warp yarn of cotton count 20s / ↓ 2 was hammered at a ratio of 1 out of 80 yarns to obtain a 1/2 twill fabric having 80 warps / inch and 50 wefts / inch. Subsequently, dyeing and finishing were carried out under the condition of ordinary polyester blended cotton fabric. This fabric 1
After being worn for a year and repeatedly washed about 250 times during that period, the amount of electrified charge was 5.2μ · coulomb / m ↑ 2 and the core resistance was 7 ×.
It was 10 ↑ 10Ω / cm · f. Conductive fiber and PET
It can be seen that the durability performance is further increased by using the mixed fiber of and.

Example 2 The W1-containing polyamide used in Example 1 was made of PBT.
(Novadoule 5008, manufactured by Mitsubishi Kasei) was spun at 265 ° C. from four discharge holes so that the sheath portion was formed, and the spinning speed was 3
The conductive core-sheath composite fiber of 25 denier / 2 filament was obtained by winding in two at 750 m / min. The core resistance of the obtained conductive core-sheath composite fiber is 5 × 10 ↑ 9Ω / cm · f,
Dangerous elongation is 12%, total strength is 2.8g / denier
The initial Young's modulus was 45 g / denier. Using this conductive fiber as a side yarn, a mixed fiber was prepared in the same manner as in Example 1, and this mixed fiber was further used in the same manner as in Example 1 to drive it into a 2/1 twill woven fabric for one year. After wearing and repeating 250 times of washing between them, the amount of charge is 4.2μ · coulomb / m ↑ 2 and the core resistance is 7 × 10 ↑
It was 9 Ω / cm · f.

PET / cotton = 65/3 made of the above conductive fiber
Covered with a blended yarn of 5, PET / cotton = 65/3
5. A warp yarn of cotton count 20s / ↓ 2 was hammered at a ratio of 1 out of 80 yarns to obtain a 1/2 twill fabric having 80 warps / inch and 50 wefts / inch. Subsequently, dyeing and finishing were carried out under the condition of ordinary polyester blended cotton fabric. This fabric 1
After being worn for a year and repeatedly washed about 250 times during that period, the amount of electrified charge is 4.5 μ · coulon / m ↑ 2, and the core resistance is 1 ×
It was 10 ↑ 10Ω / cm · f. Conductive fiber and PET
It can be seen that the durability performance is further increased by using the mixed fiber of and.

Comparative Example 1 In Example 1, the conductive fiber and PE used in the mixed fiber
Supply speed with T multifilament is 54m /
A mixed yarn was produced under exactly the same conditions as in Example 1 except that the amount was changed. When observing this mixed fiber with an optical microscope,
Both yarns were simply aligned and integrated, there was no distinction between the core yarn and the side yarn, and the difference in yarn length was 0. Using this mixed fiber, a 2/1 twill woven fabric was driven in the same manner as in Example 1 and actually worn for 1 year, during which the amount of electrified charge after repeated washing of 250 times was 5.8 μ ··· Ron/
m ↑ 2 and core resistance were 9 × 10 ↑ 10Ω / cm · f. It is considered that the PET multifilament in the mixed fiber does not sufficiently function as a strong support, so that the conductive layer of the conductive fiber is cut and the charge removal performance is deteriorated.

Comparative Example 2 Instead of the PET multifilament used in the mixed fiber in Example 1, the yarn was taken up at a spinning speed of 1000 m / min.
It was subsequently stretched at a stretch ratio of 2.5 times without winding up,
Total strength 3.9 g / denier, initial Young's modulus 41 g
/ Denier nylon-6 multifilament 30 denier / 24 filament was used to prepare a mixed fiber, and this mixed fiber was used to prepare a 2/1 twill fabric similar to that of Example 1. The fabric was actually worn for 1 year, and the amount of electrified charge after repeated 250 washings was 5.9μ ・
Coulomb / m ↑ 2, core resistance is 1 × 10 ↑ 11Ω / cm ・
It was f. Nylon-6 is the core yarn that makes up the mixed yarn.
In the case of nylon, even if the yarn length difference is within the range of the present invention, nylon-
In No. 6, the function of strong support is insufficient, and the conductive layer of the conductive fiber which is the side yarn is cut, and it is considered that the static elimination performance is deteriorated.

[0039]

EFFECTS OF THE INVENTION The mixed yarn of the present invention has excellent static elimination performance, especially the static elimination performance does not deteriorate even after long-term use or repeated washing, so that it is durable for work clothes, dust-proof clothes, school clothes, etc. It is also extremely useful in fields requiring static elimination performance. Further, it is used in various applications such as mantles, forms, uniforms, carpets, table mats, interiors, curtains, and copying machines.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location D01F 6/90 301 7199-3B (72) Inventor Masao Kawamoto 1621 Sakata, Kurashiki-shi, Okayama Within

Claims (3)

[Claims] 1. A mixed fiber comprising highly oriented undrawn conductive core-sheath composite fiber as a side yarn and non-conductive polyethylene terephthalate multifilament as a core yarn, the side yarn being more than the core yarn. Is 0.5 to 15%, the yarn length is long, and the initial Young's modulus and total strength of the core yarn are both larger than the initial Young's modulus and total strength of the side yarns. The oriented unstretched conductive core-sheath composite fiber is a polyamide system containing a polyethylene terephthalate-based or polybutylene terephthalate-based polymer (A) as a sheath component and a conductive substance composed of a conductive metal oxide. Thermoplastic polymer
Using (B) as the core component, the filament core resistance is less than 9 × 10 ↑ 10Ω / cm · f at a DC voltage of 1 kV, the critical elongation is 5% or more, and the shrinkage ratio in hot water at 100 ° C. is 20. % Or less, a conductive mixed fiber yarn. 2. The conductive mixed fiber yarn according to claim 1, wherein the total fineness of the core yarn is 20 to 100 denier. 3. The total fineness ratio of the side yarns to the core yarn is 0.2 to 2
The conductive mixed fiber yarn according to claim 1, wherein