JPS60126321A - Electrically conductive composite fiber - Google Patents

Abstract

PURPOSE:To obtain the titled fiber having excellent spinnability and low nib and yarn-breakage faults, by combining a polymer forming a nonconductive fiber with an electrically conductive thermoplastic polymer compounded with electrically conductive carbon black having specific oil absorption and surface area. CONSTITUTION:The objective composite fiber is composed of (A) an electrically conductive thermoplastic polymer such as nylon 6, 66, etc. compounded with 5- 20wt% electrically conductive carbon black having an oil absorption (dibutyl phthalate absorption) of >=400mg/100g and a surface area (measured by BET method) of >=1,100m<2>/g and (B) a nonconductive fiber-forming polymer (preferably polyamide or polyester). The arrangement of the components A and B is preferably a sheath-core structure wherein the component A is core and the component B is sheath.

Description

[Detailed description of the invention] The present invention relates to conductive composite fibers.

Synthetic fibers such as polyamide fibers and polyester fibers generally have the disadvantage of generating static electricity and being easily charged.

In order to overcome these drawbacks, methods have been taken to make synthetic fibers conductive. A typical method is to use a composition in which fine carbon black powder is dispersed as a conductive agent in a thermoplastic polymer as a conductive component, and then composite-spun it with a non-conductive fiber-forming component to obtain a conductive composite fiber. .

Acetylene black is carbon black.

There are various types such as furnace black and channel black, but in order to impart sufficient conductivity to a non-conductive polymer, these carbon blacks are generally dispersed in an amount of 15% by weight or more, preferably 30% by weight or more. There is a need.

Further, even if the blending amount of carbon black is increased in an attempt to increase the conductivity, the electrical resistance of the conductive monomer does not decrease much at 30% by weight or more. This is considered to be due to the conductive mechanism of carbon black. In other words, in a polymer in which carbon black is dispersed, carbon black has a developed structure (a chain of carbon blank particles), and when particles and shields come into contact or are very close to each other, a tunnel effect (tk particles) occurs. jump)
conductivity appears. Therefore, in order to provide conductivity, it is believed that it is necessary to disperse carbon black at a high concentration so that the carbon black particles or struture shields come into contact with each other or come very close to each other.

For these reasons, carbon black is blended into the polymer at a high concentration, but the high concentration results in poor dispersibility.As a result, conductive polymers containing carbon blank are Composite fibers may have poor spinnability or uneven conductivity.

In order to overcome these drawbacks, the purpose of the present invention is to create a thermoplastic polymer having conductivity with a low concentration of carbon black dispersion by using a conductive carbon blank, and to develop conductivity using such a polymer. The aim is to provide fiber.

The present inventors have achieved the above object (as a result of extensive research), by using conductive carbon black having predetermined oil absorption and surface area values as a conductive agent, conductive composite fibers containing low concentration carbon black can be used. The present inventors have discovered that it is possible to produce the following, and have completed the present invention.

That is, the gist of the present invention is that the oil absorption amount (dibutyl phthalate adsorption amount) is 400WLv1007 or more, and the surface area (
It is a conductive composite fiber formed by a composite arrangement of a conductive thermoplastic polymer containing 5 to 20% by weight of conductive carbon black with a BET-@) of 1100 or higher and a non-conductive fiber-forming polymer. .

The conductive carbon blank as used in the present invention has an oil absorption amount (adsorption amount of diptyl phthalate) of 4oom4/xooy- or more and a surface area (BET method) of 1xootr? /y- or more. As a conductive carbon black that satisfies this condition, Ketuyon black is C
, J-600 (manufactured by Lion Akzo).

Preferably, the carbon blank has a small particle size and contains few impurities.

In the present invention, the thermoplastic polymer in which conductive carbon black is dispersed refers to polymers such as polyamides such as nylon 6.66, polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, or polymers containing these as main components. It is a polymerized thermoplastic polymer. Further, it is possible to add a matting agent, a heat resistant agent, a light resistant agent, etc. to these thermoplastic polymers, if necessary.

The thermal n1 plastic polymer and the conductive carbon black can be mixed by known methods. Further, the amount of the conductive carbon blank is 5 to 20% by weight, preferably 8 to 15% by weight.

If the amount is less than 5 Mt%, sufficient electrical conductivity cannot be obtained, and if it exceeds 20 Mt amount, the fluidity of the polymer becomes poor and the spinneret becomes extremely unstable.

The non-conductive fiber-forming polymer as used in the present invention refers to a fiber-forming polymer such as polyamide, polyester, polyolefin, and the like. Particularly preferred are polyamides such as nylon 6.66 and polyesters such as polyethylene terephthalate.

The conductive composite fiber of the present invention is produced using a conventional composite spinning device capable of composite spinning in which two component polymers are arranged in a composite manner. Moreover, the undrawn yarn spun by composite spinning can be drawn by a known drawing method.

The composite form of the conductive thermoplastic composite fiber of the present invention and the non-conductive fiber-forming polymer may be any known form. Fang 1 - Spear 9 are examples suitable for the present invention. However, particularly preferably, a core-sheath type is selected in which the core component is a conductive thermoplastic polymer and the sheath component is a non-conductive fiber-forming polymer, as shown in Figures 1 and 1.

The conductive composite fiber obtained by the present invention can provide sufficient conductivity even though the amount of carbon black blended is small, and has fewer yarn knots, yarn breakage, etc. (as a result, the spinnability is good. Due to the small amount of black added,
The adhesion between the carbon black particles and the thermoplastic polymer is good, and there is less carbon black falling off when it is made into woven or silk fabrics.

The present invention will be specifically explained below using Examples.

Example: Ketjen Blank EC as conductive carbon black
-DJ-600 [Lion Akzo Oil absorption capacity (lid/L)
/ acid adsorption amount) 480rrtl/100f, surface area (BET method) 12qotr? /l] A conductive thermoplastic polymer of nylon 6 containing 710% by weight and nylon 6 (containing 3% by weight of titanium oxide) as a non-conductive fiber-forming polymer were melted at 285°C.・
As shown in Figure 1, the conductive thermoplastic polymer is the core, the non-conductive fiber-forming polymer is the sheath, and the sheath/core ratio is 93/7. Composite spinning. The obtained undrawn yarn had few yarn knots and yarn breakages, and had good spinnability.

The obtained undrawn yarn was preheated at 150° C. and then stretched 3.1 times to obtain a drawn yarn.

The electrical resistance of the conductive composite fiber thus obtained was measured at the end of evaluating the conductivity. The measurement was carried out by scouring the thread, cutting it into a length of 100 m, applying conductive paste to both ends, holding both ends of the thread between electrode clips, and measuring the electrical resistance of the thread with a high resistance meter (Yokogawa Honeywell). I did it.

The obtained drawn yarn has a denier of 18 and a wire resistance of 2X i
o' p/crn, the volume resistivity of only the conductive part is 25
It was 0Ω.

Comparative Example A drawn yarn was obtained in the same manner as in the example except that ordinary furnace black [oil absorption (dibutyl phthalate adsorption amount) 1021 Lv100i, surface area (BET method) 1 i o nr//y-] was used as the conductive agent. Ta.

The obtained drawn yarn has a denier of 18 and a wire resistance of 1011Ω.
The conductivity was significantly insufficient.

[Brief explanation of the drawing]

Figures 1 to 9 show specific examples of cross sections of the conductive composite fibers of the present invention. In the figure, A indicates a conductive thermoplastic polymer, and B indicates a non-conductive fiber-forming polymer. Patent Applicant: Asahi Kasei Kogyo Co., Ltd. (Figure 1, Figure 2, Figure 5, Figure 6, Figure 9, Figure 3, Figure 3, Figure 4, Figure 7, Figure 8, Voluntary writing of procedural amendments) December 10, 1980, Commissioner of the Japan Patent Office, Shi Manabu Ka, Indication of the case, Patent Application No. 233601, filed in 1982, 2, Name of the invention, Conductive Composite Fiber 3, Person making the amendment, Relationship to the case, Patent applicant: 1-2-6 Dojimahama, Kita-ku, Osaka, Osaka Prefecture No. 4, “Detailed Description of the Invention” column 5 of the specification to be amended, contents of the amendment (1) Page 4 of the specification, lines 16 to 17 [Ketjen blank C, J-600”] Ketchen Blank EC-
Corrected to DJ-600J. (2) On page 7, line 20, "paste" is corrected to "paste." (3) On page 8, line 2, "High resistance meter (Yokogawa Honeywell)" was replaced with "Insulation resistance meter (Model 14329A, manufactured by Yokogawa/Hewlett/Packard AL)"
) Correct it as J. that's all

Claims (3)

[Claims] (1) Oil absorption amount (adsorption amount of diptyl phthalate) is 400M/
1 ooy or more, and the surface area (BIT method is 1 x Oon)
5 to 20 conductive carbon blacks with r/y- or more
Conductive composite fiber made of a composite arrangement of a conductive thermoplastic polymer and a non-conductive fiber-forming polymer blended in weight percent (2) The conductive composite fiber according to claim 1, wherein the non-conductive fiber-forming polymer is polyamide or polyester. (3) The conductive composite fiber according to claim 1, wherein the composite form is a core-sheath type having a core made of a conductive thermoplastic polymer and a sheath made of a non-conductive fiber-forming polymer.