JPS6320931B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing conductive yarn, and more particularly to a method for manufacturing conductive yarn that exhibits a high whiteness index value and is made of conductive composite fibers and ordinary thermoplastic multifilament. . Conventionally, as a method for manufacturing conductive yarn, a method has been known in which conductive composite fibers containing conductive particles, such as carbon black, are mixed with fibers that are easily charged with static electricity to impart antistatic properties. There is.
However, composite fibers containing carbon black exhibit a whiteness index value of about 21 to 49, which will be described later, and exhibit a black or blackish-gray color, which limits their use. Such composite fibers are used as bulky processed yarns after being combined with ordinary thermoplastic multifilament, but when such yarns are inserted at appropriate intervals to produce white to light-colored woven or knitted fabrics, woven or knitted fabrics are produced. A drawback was that dark brown to grayish black streaks appeared on the surface of the fabric. Therefore, it has been necessary to create a woven or knitted fabric structure in which the bulky textured yarn containing the composite fibers does not appear on the surface. In recent years, various composite fibers containing white or grayish-white conductive particles have been proposed in order to overcome these drawbacks. However, attempts have also been made to combine such composite fibers with ordinary thermoplastic multifilaments and use them as bulky processed yarns as insert yarns for white to light-colored woven and knitted fabrics.
At most, a whiteness index value of up to 74 could be obtained, color differences appeared in the appearance of the fabric, and the weight of the fabric increased, making it unsuitable for use as a fabric for clothing. As a result of intensive research in order to eliminate such conventional drawbacks, the present inventors have mixed a composite fiber containing conductive tin oxide particles with a normal thermoplastic multifilament in a specific ratio, and The present invention was achieved by discovering that the conventional drawbacks can be overcome by combining and twisting at different twisting angles. The object of the present invention is to exhibit a whiteness index value of 78 or higher, which is required for a white to light-colored woven or knitted fabric, and to be suitable for clothing without increasing the weight of the fabric, and to reduce the conductive effect. An object of the present invention is to provide a method for producing a conductive yarn without causing any damage. That is, the present invention provides a thermoplastic polymer [A] containing conductive tin oxide particles and/or particles in which conductive tin oxide particles are coated on other inorganic substances, and a thermoplastic polymer [A] that has good fiber-forming properties. A composite fiber made of a plastic polymer [B] and a normal thermoplastic multifilament are mixed together so that the content of the composite fiber is 4.5 to 4.5.
78 or more, characterized in that they are mixed to a concentration of 18.5% by weight, twisted together under conditions such that the twist angle calculated from the following formula (1) is 20° to 27°, and then subjected to a false twisting process. A method for producing a conductive yarn exhibiting a whiteness index value, and a thermoplastic polymer containing conductive tin oxide particles and/or particles in which conductive tin oxide is coated on another inorganic substance [ A) and a thermoplastic polymer with good fiber forming property [B] Composite fiber and bulky textured yarn (hereinafter simply referred to as bulky textured yarn) obtained by false twisting ordinary thermoplastic multifilament. 78 or more, characterized in that they are mixed so that the fiber content is 4.5 to 18.5% by weight and twisted under conditions such that the twist angle calculated from the following formula (1) is 20° to 27°. The gist of this paper is a method for producing conductive yarn that exhibits a whiteness index value. θ: Twisting angle D: Total fineness (denier) of composite fiber and normal thermoplastic multifilament T: Number of twists (T/M) The present invention will be described in detail below. First, the composite fiber used in the present invention will be explained. In the present invention, the composite fiber is a thermoplastic polymer [A] containing conductive tin oxide particles and/or particles in which conductive tin oxide is coated on another inorganic substance, and a thermoplastic polymer [A] that has good fiber formation. Composite fibers made of thermoplastic polymer [B] are used, and conductive tin oxide particles or particles coated with conductive tin oxide on other inorganic substances are manufactured by known methods. . Other inorganic substances include titanium oxide, zinc oxide, calcium oxide, magnesium oxide, barium oxide, alumina, and the like. Particularly preferred are particles containing stannic oxide whose conductivity is enhanced by a small amount of an antimony compound or the like. In addition, these particles have a specific resistance of 10 ³ Ω·cm or less, preferably 10 ² Ω·cm or less, from the viewpoint of electrical conductivity, and a particle diameter of 5 μ or less, preferably 3 μ, from the viewpoint of operability in composite fiber production. It is as follows. As described above, the composite fiber of the present invention is composed of a thermoplastic polymer [A] containing conductive particles and a thermoplastic polymer [B] with good fiber-forming properties, but the thermoplastic polymer [A], [B] is polyethylene terephthalate, polybutylene terephthalate, poly-
Polyesters containing 1,4-cyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalate, poly-p-ethyleneoxybenzoate, etc. as main components, nylon 6, nylon 8, nylon 12, nylon 66, nylon 6, 10, etc. Typical polymers include polyamide, whose main component is polyamide, and polyolefin, whose main component is polyethylene, polypropylene, etc. As component [B], a polymer with particularly excellent fiber-forming ability is selected, but [A]
As a component, a polymer having poor fiber-forming ability may be used in order to improve the dispersibility of the stannic oxide-containing particles. The amount of the conductive stannic oxide-containing particles is 25-80% by weight, preferably 30-75% by weight in component [A], considering the conductivity. Further, the weight ratio of component [A] and component [B] constituting the composite fiber is 5:95 to 50:50, preferably 15:85 to 50:50. The cross-sectional shape of such composite fibers may be either one in which the [A] component is the core part and the [B] component in the sheath part, or one in which the [A] component is scattered on the surface part of the [B] component. The above composite fiber has a whiteness index value of 68 to 76, which will be described later, and is gray in color. The electrical resistance value indicating the conductive effect is, for example, about 8×10 ⁷ Ω/cm. In the present invention, the above-mentioned composite fibers and ordinary thermoplastic multifilament are twisted together and subjected to a false twisting process, or the composite fibers and ordinary thermoplastic multifilament are subjected to a false twisting process in advance to form a bulky textured yarn. By twisting and twisting the composite fibers, the composite fibers are covered with ordinary thermoplastic multifilament.
The conductive yarn has a high whiteness and exhibits a whiteness index value of 78 or more. The above-mentioned usual thermoplastic multifilament is made of polyester, nylon, etc., and has a whiteness index value of 85 to 87. In the present invention, in order to obtain a yarn with a high whiteness index value of 78 or more suitable for white to light-colored fabrics and a light basis weight suitable for clothing fabrics, the content of composite fibers is low. However, if the content is too low, the conductive efficiency will be low, while if the content of composite fibers is too high, high whiteness will not be obtained. Therefore, in the present invention, the content of composite fibers is 4.5
-18.5% by weight, preferably 8-16% by weight. Furthermore, in the present invention, the twisting angle when the composite fibers and the normal thermoplastic multifilament are combined and twisted is important, and the twisting angle needs to be 20° to 27°. When the twist angle is less than 20 degrees, the multifilaments of the bulky yarn cannot cover the composite fibers evenly, and the composite fibers appear in a loop shape on the surface of the bulky yarn, reducing whiteness. This results in a difference in appearance when inserted into a fabric, and if the twist angle exceeds 27°, the conductivity of the composite fiber tends to decrease. In the present invention, the whiteness index value is measured as follows. The sample was made into a tubular knitted fabric using a 20-gauge sock knitting machine, boiled in boiling water containing 0.5% by weight of a scouring agent (Sunmoor FL, manufactured by NICCA Chemical Co., Ltd.) for 20 minutes, and then washed with water and dried. After layering this tubular knitted fabric twice, use a chromaticity meter [manufactured by Tokyo Denshoku Co., Ltd.]
The L value (lightness) is measured and used as the white index value. In the present invention, as described above, the conjugate fiber containing conductive tin oxide and the normal thermoplastic multifilament are mixed at a content rate of 4.5 to 18.5.
% by weight, it is possible to obtain highly white conductive yarn without reducing the conductive effect, and even if this yarn is inserted to give antistatic properties to the fabric. The weight of the fabric does not become too heavy, and it is preferable as a yarn for obtaining antistatic clothing fabrics. Furthermore, since the twisting angle is 20° to 27°, the composite fibers can be evenly covered with a normal multifilament, resulting in a highly white conductive yarn with a whiteness index value of 78 or higher. Even if it is used as an insertion yarn in a white to light colored fabric, it does not give a difference in the appearance of streaks. Moreover, no difference in appearance is caused regardless of the structure of the woven or knitted fabric. In addition, since the composite fibers are twisted at the above-mentioned twisting angle, the twisting strain imparted to the composite fibers is small, and the conductive effect of the composite fibers is less likely to be degraded. Hereinafter, the present invention will be specifically explained with reference to Examples. Example 1 Tinnic oxide particles with a particle size of 0.5μ and a specific resistance of 1Ω・cm
Chips [A] obtained by dissolving 50 parts in 50 parts of nylon 6 and uniformly dispersing them and regular nylon 6 chips [B] were mixed in a weight ratio of 15:85 using an extruder type melt composite spinning machine. It was discharged from a spinning hole with a number of spinning holes of 2 at 270°C and wound at 2500 m/min to obtain a composite fiber of 20 denier/2 filaments having chips [A] as a core component and chips [B] as a sheath component. . The unique performance of this composite fiber is as follows:
The hue is grayish white and the whiteness index value (L value) is 70.
The electrical resistance value was 8×10 ⁷ Ω/cm. This composite fiber and normal polyester multifilament 150 denier/48 filament (L value;
86) are arranged so that the composite fiber content is 12% by weight, and the twist angle θ is 15°, 21°, 26°, respectively.
Twisted with a ring twister so that the angle is 30°, and then false-twisted with a single heater false-twisting machine at a spindle rotation speed of 300,000 rpm, a false twist number of 2456 T/M, a heater temperature of 210°C, and an overfeed rate of 3.5%. was applied. The appearance state of the obtained bulky processed yarn is θ
= 15°, the composite fibers appeared in a loop shape on the surface of the bulky textured yarn and were asymmetrical, but when θ =
In the case of 21°, 26°, and 30°, the polyester multifilament bulky yarn uniformly covered the composite fibers. In addition, the electrical resistance value of the bulky processed yarn is θ
When θ = 15°, 21°, and 26°, it was 6 to 8 × 10 ⁷ Ω/cm, and the conductive effect was satisfactory, but when θ = 30°, it was 7 Ω/cm.
×10 ⁹ Ω/cm, and the conductive effect was insufficient. Furthermore, this bulky textured yarn is inserted at a rate of 1 thread/inch in the warp direction of a 2/2 twill fabric made of ordinary 150 denier polyester filament bulky textured yarn/100% 48 filament, and the resulting fabric is dyed [Nippon Kayaku Co., Ltd.] Finished by dyeing with company-made NiKa white ATN2% owf]. When we investigated the appearance quality of this fabric, when θ = 15°, gray-white lines appeared and the quality was poor, but when θ = 21°, 26°, and 30°, no color unevenness was observed and it was good. It was with great dignity. The results are shown in Table 1.

[Table] Example 2 The composite fiber used in Example 1 was 75 denier/24
Filament, 100 denier/24 filament,
150 denier/30 filament, 200 denier/48
Filament, 450 denier/96 filament,
It was twisted with a regular polyester multifilament of 600 denier/144 filament using a ring twister so that θ=25°. Next, using a single heater false twisting machine, the spindle rotation speed was 300,000 rpm, the heater temperature was 210°C, the overfeed rate was 3.5%, and the number of false twists was 3590, 3100, 2456, 2170, 1480, respectively.
A bulky textured yarn was created by false twisting under the conditions of 1270T/M. The appearance of the obtained bulky textured yarn is that in each case, the polyester multifilament bulky textured yarn evenly covers the composite fibers, and the electrical resistance value of the bulky textured yarn is 6 to 8×10 ⁷
The conductivity effect was satisfactory at Ω/cm. Further, the L values were 74, 78, 79, 82, 83, and 84, respectively, and the color was gray to grayish white. These various bulky textured yarns were inserted at a rate of 1 thread/inch in the warp direction of a 2/2 twill fabric made of 100% bulky textured yarn of polyester multifilament, which was separately processed under the conditions of each denier. The fabric was dyed and finished in the same manner as in Example 1, and its appearance quality was examined. In the case of the bulky textured yarn with 75 denier/24 filaments, the coverage of the composite fibers was sufficient, but the hue of the composite fibers in the bulky textured yarn penetrated to the surface, causing grayish-white lines to appear, impairing the quality. It was inferior. Also, as a 2/2 twill fabric, it is 450 denier/96
Although the filament, 600 denier/144 filament, had extremely good quality, it was unsuitable for use in clothing because of its excessive basis weight.

[Table] Example 3 Ordinary polyester multifilament 150 denier/48 filament was false-twisted using a single heater false twisting machine at a spindle rotation speed of 300,000 rpm and number of false twists.
False twisting was performed at 2456T/M, heater temperature 210℃, and overfeed rate 3.5%. The obtained bulky processed yarn and the composite fiber used in Example 1 were aligned so that the content of composite fiber was 12%, and the twist angle θ was 15°, 21°, 23°, 26°, and 30°. , and twisted them together using a ring twister. The appearance of the obtained bulky textured yarn is asymmetrical, with composite fibers appearing in the form of loops on the surface of the bulky textured yarn when θ = 15°, and small loops also occur when θ = 21°. death,
The coating effect was insufficient. θ=23°, 27°, 30°,
In the case of , the polyester bulky processed yarn uniformly covered the composite fibers. Further, the electrical resistance value of the bulky textured yarn was the same as in Example 1, except for the case where θ=30°, a conductive effect was obtained. Furthermore, 2/2 twill fabrics were made from these bulky processed yarns in the same manner as in Example 1, dyed and finished, and the appearance quality was investigated. A line appears, and although the quality is inferior, θ=
In the case of 23°, 27°, and 30°, no color unevenness was observed and the quality was good.

【table】

【table】

Claims (1)

[Scope of Claims] 1. A thermoplastic polymer [A] containing conductive tin oxide particles and/or particles obtained by coating conductive tin oxide on other inorganic substances, and a thermoplastic polymer [A] having good fiber-forming properties. The twist angle calculated from the following formula (1) by mixing composite fibers made of thermoplastic polymer [B] and ordinary thermoplastic multifilament so that the content of composite fibers is 4.5 to 18.5% by weight. 1. A method for producing conductive yarn exhibiting a whiteness index value of 78 or more, comprising twisting and twisting under conditions such that the angle is 20° to 27°, and then false-twisting. θ: Twisting angle D: Total fineness (denier) of composite fiber and normal thermoplastic multifilament T: Number of twists (T/M) 2 Conductive tin oxide particles and/or other inorganic substances False-twisting is applied to a composite fiber consisting of a thermoplastic polymer [A] containing particles coated with stannic oxide and a thermoplastic polymer [B] with good fiber forming properties, and a normal thermoplastic multifilament. The content of composite fiber is 4.5
It exhibits a whiteness index value of 78 or more, characterized by mixing to a concentration of ~18.5% by weight and twisting under conditions such that the twisting angle calculated from the following formula (1) is 20° to 27°. Method for manufacturing conductive yarn. θ: Twisting angle D: Total fineness (denier) of composite fiber and normal thermoplastic multifilament T: Number of twists (T/M)