JPH06200416A - Electrically conductive conjugate fiber - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an electroconductive composite fiber exhibiting excellent electroconductivity and having good durability. When a composite fiber containing a fiber-forming polymer as a non-conductive layer component and a thermoplastic polymer containing conductive metal compound particles as a conductive layer component is contained in the conductive layer component, The organic sulfonate compound is mixed in an amount of 5 to 50 parts by weight with respect to 100 parts by weight of the thermoplastic polymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive composite fiber having excellent durability. More specifically, the present invention relates to a conductive composite fiber which is excellent in durability in a post-processing step or worn and can exhibit excellent static elimination performance for an extremely long period of time, and is particularly suitable for clothing.

[0002]

2. Description of the Related Art Synthetic fibers such as polyester fibers,
Since polyamide-based fibers and the like have low conductivity, there is a problem in that static electricity is generated due to friction, and various kinds of obstacles due to dust adhesion and discharge occur.

In order to solve such problems and obtain conductive fibers having high whiteness, a method of blending various white or colorless conductive substances has been proposed in recent years. For example, Japanese Patent Publication Sho 5
Japanese Unexamined Patent Publication No. 8-39175 discloses an antistatic fiber made of polyester containing 3 to 20% by weight of titanium oxide particles having a stannic oxide film. However, this material has extremely low conductivity and cannot be said to be a conductive fiber.

Further, JP-A-57-6762 and JP-B-62-29526 disclose a conductive layer component composed of a conductive metal oxide and a thermoplastic polymer, and a non-fiber-forming component. A conductive fiber obtained by composite spinning with a conductive layer component is disclosed. However, since the conductive performance deteriorates in the stretching process performed to improve the mechanical properties of the conductive fiber, it is necessary to perform a heat treatment after the stretching to restore the conductive layer component, which not only complicates the manufacturing process. However, there is a problem in terms of durability that the conductive layer component is continuously broken due to expansion and contraction repeatedly applied during use, and the conductive performance is deteriorated.

Recently, in order to solve such a problem, Japanese Unexamined Patent Publication (Kokai) No. 2-307911 proposes a method of using a conductive metal oxide whisker as a conductive substance and a thermoplastic elastomer as a thermoplastic polymer. ing.

However, according to such a method, since the whiskers have a large specific surface area, it is easy to entrap air bubbles when kneading into the thermoplastic polymer, and the durability of the conductive performance during use is somewhat improved as compared with the conventional method. However, it is still not at a satisfactory level.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art, and its purpose is to:
An object of the present invention is to provide a conductive fiber having excellent durability of conductive performance in a post-processing step or during use.

[0008]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a specific amount of an organic sulfonate compound is added to a conductive layer component containing conductive metal compound particles. It has been found that the durability of the conductive performance is remarkably improved and that the above-mentioned effects are increased when a polyolefin is used as the thermoplastic polymer in the conductive layer component, and the present invention is achieved.

That is, according to the present invention: In a conductive composite fiber in which a fiber-forming polymer is used as the non-conductive layer component (A) and a thermoplastic polymer containing conductive metal compound particles is used as the conductive layer component (B), the component B contains heat 1. A conductive composite fiber, wherein an organic sulfonate compound is mixed in an amount of 5 to 50 parts by weight with respect to 100 parts by weight of a plastic polymer. There is provided the conductive composite fiber according to the above 1, wherein the thermoplastic polymer in the component B is a polyolefin.

The polymer serving as the component (A) which constitutes a part of the electroconductive composite fiber of the present invention may be a melt-spinnable fiber-forming polymer. Specific examples of such a polymer include:
Examples thereof include polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 6,6, polyolefins such as polyethylene and polypropylene. Further, a copolymer or a mixed polymer containing these as main components can be mentioned. The polymer constituting the component (A) may contain any additive such as a matting agent, a coloring agent, an oxidation stabilizer, and a dye improving agent, if necessary.

The component (B) constituting the conductive part of the conductive composite fiber of the present invention is a composition obtained by blending a thermoplastic polymer containing conductive metal compound particles with an organic sulfonate compound. Become. The thermoplastic polymer used here includes polyethylene, polypropylene, polystyrene, polybutadiene, polyisoprene, nylon 6,
The main objects are nylon 6,6, polyethylene terephthalate, polybutylene terephthalate, etc., but some of them may be replaced by copolymerization, and if they are thermoplastic polymers, polymers other than the above may be used depending on the purpose. They may be used, and if necessary, a mixture of two or more thereof may be used. Of these, polyolefins such as polyethylene are particularly preferable because the fibers finally obtained have good electrical conductivity and durability during use.

The conductive metal compound particles are not particularly limited as long as the powdery specific resistance is about 10 ⁴ Ωcm or less, and metal powders, metal sulfides such as copper sulfide, zinc sulfide and cadmium sulfide, iodine Any of metal halides such as cuprous oxide, tin oxide, zinc oxide, copper oxide, silver oxide, cadmium oxide, indium oxide, zirconium oxide, tungsten oxide, lead oxide and the like can be used. . The shape of the particles is not particularly limited, and any particles such as spherical particles, acicular particles, and whiskers can be used.

Many of the above metal oxides are semiconductors close to insulators and often do not show sufficient conductivity, but conductivity can be improved by adding a small amount of an appropriate second component. it can. Examples of such a conductivity enhancer (hereinafter sometimes referred to as a doping agent) include oxides of different metals, and same or different metals. Specifically, for example, antimony oxide is added to tin oxide, copper is added to copper oxide, and aluminum oxide is added to zinc oxide.

The amount of the doping agent added is determined by the electrical conductivity of the conductive metal oxide and the degree of coloring of the particles. Further, such conductive metal oxide particles may be those in which the surface of the metal oxide having high whiteness is covered with the conductive metal oxide. That is, a conductive metal in which the surface of a metal oxide particle having a 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. Oxide particles are preferable because they have good whiteness and electric conductivity.

The average particle size of the conductive metal oxide particles is preferably in the range of 0.1 to 2.0 μm from the viewpoint of good conductive performance and process stability such as spinning. The average particle size here is a weight average particle size determined by the centrifugal sedimentation light transmission method.

The amount of the conductive metal compound particles to be mixed is preferably 0.25 to 4.0 times the weight of the polymer as the component (B) in view of the balance between the conductive performance and the moldability.

In the present invention, it is essential that the thermoplastic polymer containing the conductive metal compound particles is blended with an organic sulfonate compound. Above all, it is preferable that the thermoplastic polymer is substantially non-reactive, and examples thereof include metal sulfonates represented by the following general formula.

RSO ₃ M In the formula, R is an alkyl group having 3 to 30 carbon atoms or 7 to
40 represents an aryl group, and the alkyl group may be linear or may have a branched side chain. M is N
It is an alkali metal such as a, Li or K or an alkaline earth metal such as Mg or Ca, and Na is preferable.

Specific examples preferably used include, for example, sodium stearyl sulfonate, sodium octyl sulfonate, sodium dodecyl sulfonate, a mixture of sodium alkyl sulfonates having an average number of carbon atoms of 14 and sodium dodecylbenzene sulfonate (hardware). Type, soft type), potassium dodecylbenzene sulfonate (hard type, soft type), magnesium dodecyl benzene sulfonate (hard type, soft type) and the like, and these may be used alone or 2 You may use it in mixture of 2 or more types.

The amount of the organic sulfonate compound compounded is 5 with respect to 100 parts by weight of the thermoplastic polymer in the component B.
It should be in the range of 50 parts by weight. If the blending amount is less than 5 parts by weight, the effect of improving the electroconductivity and durability will be insufficient, which is not preferable. On the other hand, if the amount exceeds 50 parts by weight, coloring due to thermal decomposition of the organic sulfonate compound becomes severe, which is not preferable.

In order to mix the thermoplastic polymer in the component (B) with the conductive metal compound particles and the organic sulfonate compound, any method can be adopted as long as it can be well dispersed and mixed. be able to. At this time, if desired, any additive such as a coupling agent, a matting agent, a colorant, an antioxidant, a dyeability improving agent and the like may be added.

The shape of the composite fiber composed of the above-mentioned component (A) and component (B) may be either side-by-side type or core-sheath type, and is a conductive layer component (B).
The cross-sectional shape of the component can take any shape, and the number thereof can also take any number of 1 or more.

The ratio of the component (A) to the component (B) in the cross section of the fiber can be set in a wide range, but if the ratio of the component (B) becomes too large, the strength of the conductive fiber obtained will decrease. Therefore, the proportion of the component (B) in the fiber cross section is preferably 50% or less. Further, the lower limit of the component (B) only needs to be such that the component (B) continuously exists along the fiber axis direction, and is usually 1% or more, particularly preferably 3% or more of the fiber cross-sectional area. .

It is not necessary to employ special methods and conditions for producing such electroconductive conjugate fibers, and the melt spinning method and conditions for producing bicomponent composite fibers are arbitrarily selected according to the component (A). Can be applied. Further, in the present invention, the fiber obtained by spinning is drawn to obtain sufficient strength. As for the stretching method and conditions, any method is appropriately adopted.

[0025]

ACTION AND EFFECTS OF THE INVENTION Conventionally, a conductive composite fiber containing a polymer containing conductive metal oxide particles as one component has a long service life even if the conductive performance immediately after production is at a good level. Inferiorly, there was a problem that the conductive performance was significantly reduced in an extremely short time. It is presumed that such a phenomenon is because when a load, for example, a tension is applied to the conductive composite fiber during use, the conductive structure is easily destroyed and the continuity of the conductive layer is interrupted.

On the other hand, the conductive composite fiber of the present invention is
Since the organic sulfonate compound is added to the conductive layer component in addition to the conductive metal compound particles, the detailed reason has not yet been clarified, but the conductive performance and its durability are improved due to the following reasons. It is presumed to do. That is, even if the continuous structure of the conductive metal compound particles is destroyed by stress such as tension applied during use, the thermoplastic polymer between the conductive metal compound particles still contains an organic sulfonate of an ionic compound. Since the compound is blended, the insulation resistance value between the particles is remarkably reduced, and as a result, it is presumed that the reduction of the conductive performance is remarkably suppressed.

Further, since the sulfonate compound has a surface-active effect, while the metal oxide is generally hydrophilic, when the thermoplastic polymer is a polyolefin,
The conductive metal compound particles can be differentiated into the component B by the surface active effect. As a result, it is possible to increase the blending amount of the conductive metal oxide particles without deteriorating the process stability during spinning, and it is possible to stably obtain a conductive fiber having excellent durability and conductive performance. It is estimated that

[0028]

EXAMPLES The conjugate fiber of the present invention will be described in more detail below with reference to examples. In addition, each evaluation item in the examples followed the following methods.

Electric resistance value (Ω / cm) Single fiber was cut into a length of 1 cm, placed on a polyethylene terephthalate film, and a conductive paint was applied to both cut surfaces (both ends) at a temperature of 20 ° C. and a humidity of 30% RH. The resistance value is measured at a DC voltage of 1 KV.

Durability test The conductive composite fiber was covered with a polyester fiber / cotton = 65/35 blended yarn, and polyester fiber / cotton = 65.
/ 35, 1 out of 80 yarns in a warp yarn of cotton count 20; warp yarn 80 / 25mm, weft yarn 50 / 25mm 2/1
Twill fabric. The obtained woven fabric was dyed and finished under the conditions usually applied to polyester cotton mixed woven fabrics, and then repeatedly washed 200 times. Then, the conductive composite fiber was taken out from the woven fabric, and the electric resistance value was measured by the above method.

Charged Electric Value According to JIS L 1094 Triboelectric Charged Electric Charge Measurement Method
It was This value is 7 μC / m ²The following is good.

[0032]

Examples 1 to 5 and Comparative Examples 1 to 4 The conductive metal compound and the organic sulfonate compound shown in Table 1 were added in the proportions shown in Table 2 to polyethylene (Sumikasen G8 manufactured by Sumitomo Chemical Co., Ltd.).
07) Heat-mixed in 100 parts by weight, and using the resulting mixed composition as a core part and polyethylene terephthalate containing 2.5% by weight of titanium oxide as a sheath part, spinning using a concentric core-sheath composite spinning machine. And stretched 4 times at 130 ° C,
Heat setting was performed at 60 ° C. to obtain a composite fiber. The area ratio of the core and the sheath in the cross section of this fiber is 1: 6, and the fiber composition is 30.
It was a denier / 3 filament. The results are summarized in Table 2.

[0033]

[Table 1]

[0034]

[Table 2]

As is clear from the above results, a conductive composite fiber having a conductive layer in which a thermoplastic polymer containing conductive metal oxide particles is blended with an amount of the organic sulfonate compound specified in the present invention. Shows that it exhibits excellent conductive performance and its durability during use is also good.

Claims (2)

[Claims] 1. A non-conductive layer component (A) containing a fiber-forming polymer.
And a thermoplastic polymer containing conductive metal compound particles as a conductive layer component (B), in the component B, an organic sulfonate is added to 100 parts by weight of the thermoplastic polymer. A conductive composite fiber, wherein the compound is mixed in an amount of 5 to 50 parts by weight. 2. The electrically conductive composite fiber according to claim 1, wherein the thermoplastic polymer in the component B is a polyolefin.