JPH036274B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a conductive composite fiber and a method for producing the same, and more specifically, to a conductive composite fiber having excellent conductive performance in which conductive short fibers protrude from the surface of the fiber made of synthetic resin. The present invention relates to a composite fiber and a method for producing the same.

(Prior art) When carpets, clothes, etc. generate static electricity due to friction between fibers and are charged, they attract dirt and dust, making them more dirty, causing damage to surrounding electronic equipment, and causing harm to people. There were negative effects such as giving an unpleasant electric shock. For this reason, many conductive fibers used for antistatic purposes have been proposed.

As the conductive fiber, fiber 5 shown in FIG.
0, a thermoplastic resin 51 mixed with a conductive component 52 such as carbon fiber or carbon black and uniformly dispersed therein, and the fiber shown in FIG. 6 proposed in JP-A-62-170508. 60, the fiber cross section is spun into a polygonal shape such as a star shape, and the conductive substance-containing thermoplastic polymer 61 is arranged only in a part of the protrusion, and Japanese Patent Publication No. 52-31450
There are core-sheath structures proposed in Japanese Patent Publication No. 62-90316 and the like.

(Problem to be Solved by the Invention) However, as shown in FIG. 6, the conductive fiber 60 whose fiber cross section is spun into a polygonal shape, or the conductive fiber having a core-sheath structure, requires a special spinning process during its manufacture. There is a problem in that it is expensive because it requires equipment.

Furthermore, in conductive fibers with a core-sheath structure or conductive fibers 50 in which conductive components 52 are uniformly dispersed in thermoplastic resin 51 as shown in FIG. 5, there is only a small amount of conductive component 52 on the fiber surface. Since it is not exposed, there is a problem that the conductive performance is inferior. This conductive performance can be improved by increasing the mixing ratio of the conductive component 52, but increasing the mixing ratio of the conductive component 52 poses a problem in that physical properties such as strength deteriorate.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a conductive composite fiber that has excellent physical properties such as strength, excellent conductivity, and is easy to manufacture and inexpensive, and a method for manufacturing the same.

(Means for Solving the Problems) In order to achieve the above object, in the conductive composite fiber according to claim 1, the surface of the fiber made of a synthetic resin mixed with conductive short fibers such as carbon fibers is It is characterized by the fact that conductive short fibers are provided so as to protrude.

In addition, in the method for producing conductive composite fibers according to claim 2, after mixing conductive short fibers such as carbon fibers with synthetic resin and spinning them, only the synthetic resin on the surface of the spun fibers is treated with a solvent. It is characterized in that the conductive short fibers are made to protrude from the surface of the fibers by melting the fibers.

(Function) According to the structure according to claim 1, the fibers made of synthetic resin mixed with conductive short fibers such as carbon fibers do not have scratches on the surface, so physical properties such as strength etc. It can be used as a pile for carpets, etc., and also has excellent conductive performance and discharge performance due to the conductive short fibers protruding from the surface of the fiber.

Furthermore, in the structure according to claim 2, after mixing conductive short fibers such as carbon fibers with synthetic resin and spinning them, only the synthetic resin on the surface of the spun fibers is dissolved with a solvent. Since the conductive short fibers protrude from the surface of the fiber, a conductive composite fiber in which the conductive short fibers protrude from the surface of the fiber made of synthetic resin can be easily obtained.

(Example) Hereinafter, an example of a conductive composite fiber embodying the present invention and a method for manufacturing the same will be described with reference to the accompanying drawings.

As shown in FIG. 1, this conductive composite fiber 1 is
Conductive short fibers 3 such as carbon fibers are provided on the surface of fibers made of non-conductive synthetic resin 2 so as to protrude.

Therefore, in this conductive composite fiber 1, since many conductive short fibers 3 are protruding from the fiber surface, the overall conductive performance is excellent, and each conductive short fiber 3 has good static electricity. is discharged.

The conductive short fibers 3 may be appropriately selected from carbon fibers, metal fibers, ceramic fibers, and the like.

Next, a method for manufacturing the conductive composite fiber 1 will be explained. To manufacture the conductive composite fiber 1, chips of a non-conductive synthetic resin that can be melt-spun, such as nylon, polyester, polypropylene, polyethylene, etc., are first prepared as the main raw material.

On the other hand, as an auxiliary raw material, conductive short fibers 3 having a finer denier than the conductive composite fiber 1 as a product are prepared. This is because if the conductive short fibers 3 are too thick, the texture, physical properties, etc. of the manufactured conductive composite fiber 1 will become unstable.

Furthermore, the cut length of the conductive short fibers 3 is determined by taking into account the diffusivity when mixed with the main raw material, and also taking into consideration the appropriate texture, physical properties, conductive performance, etc. of the conductive composite fiber 1 as a product. The thickness is preferably 5 mm or less.

Next, the synthetic resin 2 as the main raw material and the electrically conductive short fibers 3 as the auxiliary raw material whose mixing ratio to the main raw material is preferably about 10% or less are thoroughly mixed. The reason for such a mixing ratio is to ensure that the next spinning process is performed stably and that the texture, physical properties, etc. of the conductive composite fiber 1 to be manufactured are close to the properties of the synthetic resin 2 itself. This is to do so.

Next, the mixture of the main raw material and the auxiliary raw material is used as a raw material for spinning (primary processing).

As this spinning method, the melt spinning method is first known, and in this melt spinning method, a synthetic resin 2 mixed with conductive short fibers 3 is heated and melted, extruded through pores, spun, and then cooled and solidified. It is then stretched. In this melt spinning method, it is desirable that the melting point of the conductive short fibers 3 is 100 degrees Celsius or more higher than the melting point of the synthetic resin 2, which is the main raw material.

Note that as another spinning method, an extrusion spinning method is known. In this extrusion spinning method, when the thermal decomposition of the synthetic resin 2 starts at its melting point, the synthetic resin 2 mixed with conductive short fibers 3 is heated to a softening point lower than the melting point of the synthetic resin 2, and then it is passed through the pores. It is extruded and spun.

Further, as another spinning method, a wet spinning method is known. In this wet spinning method, the synthetic resin 2 is dissolved in a solvent to obtain a spinning stock solution, this spinning stock solution is extruded through pores into a coagulation bath and coagulated to form a filament, and this filament is subjected to stretching, heat treatment, drying, etc. .

Fibers 1a spun by each of the above spinning methods
As shown in FIG. 2, a part of the conductive short fibers 3 is exposed on the surface, and the conductive short fibers 3
Because they are intertwined and in contact with each other,
The overall structure also has electrical conductivity. or,
Since the spun fiber 1a has a low mixing ratio of the conductive short fibers 3, its physical properties such as strength are close to those of the fiber made only of the synthetic resin 2 as the main raw material. However, the conductive performance of the spun fiber 1a is somewhat inferior because the exposed portion of the conductive short fibers 3 on the surface thereof is small.

Therefore, in order to improve the electrical conductivity of the spun fiber 1a, the following processing (secondary processing) is performed.

That is, by dissolving only the synthetic resin 2 on the surface of the fiber 1a spun by the above-mentioned spinning methods with a solvent and making the fiber 1a slightly thinner, the conductive short fiber 3 is formed as shown in FIG. is made to protrude from the surface of the conductive composite fiber 1. In this processing method, a solvent is prepared that dissolves the synthetic resin 2 as the main raw material and does not dissolve the conductive short fibers 3 as the auxiliary raw material, and the spun fibers 1a are placed in an atmosphere containing a certain concentration of the solvent.
One method is to pass. Another method is to pass the spun fibers 1a through a solution containing the solvent.

Then, the electrically conductive composite fiber 1 manufactured by secondary processing has electrically conductive short fibers 3 on its surface.
Not only is the conductive performance greatly improved due to the increased exposed portion, but the manufacturing process is simple and can be manufactured at low cost. Furthermore, during the secondary processing, the spun fibers 1a are not scratched or torn, so that the conductive composite fibers 1 produced through the secondary processing are not as good as the physical properties such as strength. It doesn't change much from before.

Next, an example of an automobile mat having antistatic performance provided using the conductive composite fiber 1 will be described.

As shown in FIGS. 3 and 4, this automotive mat 10 has a plurality of piles 2 that penetrate through a base fabric 11 and a conductive layer 12 bonded to the back surface of the base fabric 11.
0 is driven in to finish the pile to a predetermined volume, and a binding thread 21 is sewn to the base fabric 11 and the conductive layer 12 so that the pile 20 that has been driven in does not come off. Further, the back side of the conductive layer 12 is lined with a lining material 13 made of thermoplastic synthetic resin.

The base fabric 11 is a woven fabric, mesh, or nylon woven fabric cut into a predetermined shape. The conductive layer 12 exists in the form of a stack of conductive materials such as powdered, granular, or short fiber carbon materials, conductive ceramics, or metals, and is used when getting in and out of a car. It is designed to absorb static electricity generated due to friction between the automobile mat 10 and the hem of shoes or pants during driving or the like.

The pile 20 is made by preparing a plurality of yarns bundled at a ratio of about 40 nylon fibers to 11 conductive conjugate fibers, and twisting them to a predetermined thickness.

Therefore, in this automobile mat 10,
The conductive composite fibers 1 with excellent conductive performance included in the pile 20 come into contact with the conductive material of the conductive layer 12, and the static electricity absorbed by the conductive layer 12 protrudes to the surface of the conductive composite fibers 1. Since the electric discharge is efficiently carried out in the air through the short fibers 3, the static electricity attracts dirt and dust, causing serious dirt, causing damage to surrounding electronic equipment, and causing unpleasant electric shocks to people. Harmful effects can be prevented.

Furthermore, since the conductive composite fiber 1 has excellent physical properties such as strength, it will not break even when used for the pile 20 forming the surface of an automobile mat 10, etc., which is laid under people's feet and is constantly trampled on. Therefore, the antistatic effect of the automobile mat 10 can be maintained for a long period of time.

It should be noted that the present invention is not limited to the above embodiments, and may be modified as appropriate without departing from the spirit of the present invention, such as by appropriately changing the spinning method of the fiber 1a, the raw material of the conductive composite fiber, etc. Examples may also be provided.

(Effects of the invention) As detailed above, the conductive composite fiber according to the present invention has excellent conductive performance due to the conductive short fibers protruding from the fiber surface, and also has static electricity from the conductive short fibers. This has the excellent effect of efficiently discharging electricity and providing textile products with excellent antistatic performance.

Further, the method for producing a conductive conjugate fiber according to the present invention has the excellent effect of being able to easily and inexpensively provide a conductive conjugate fiber in which conductive short fibers protrude.

[Brief explanation of the drawing]

Fig. 1 is an enlarged perspective view showing an example of a conductive composite fiber embodying the present invention, and Fig. 2 is an enlarged perspective view of a fiber spun by mixing conductive short fibers such as carbon fibers with synthetic resin. , FIG. 3 is a perspective view of an automobile mat using the conductive composite fiber of the present invention, FIG. 4 is an enlarged sectional view of the main part of the automobile mat, and FIG.
The figure is an enlarged sectional view of a conventional conductive fiber, and FIG. 6 is an enlarged sectional view of another conventional conductive fiber. Explanation of symbols, 1... Conductive composite fiber, 1a...
Spun fiber, 2...Synthetic resin, 3...Conductive short fiber, 10...Automobile mat, 20...Pile.

Claims (1)

[Scope of Claims] 1. A conductive composite fiber characterized in that the conductive short fibers are provided on the surface of a fiber made of a synthetic resin mixed with conductive short fibers such as carbon fibers so as to protrude. 2. After mixing conductive short fibers such as carbon fibers with synthetic resin and spinning them, only the synthetic resin on the surface of the spun fibers is dissolved with a solvent, and the conductive short fibers are made to protrude from the surface of the fibers. 1. A method for producing a conductive composite fiber, characterized in that: