JPH03163709A - Manufacture of conductive fiber base material - Google Patents

Abstract

PURPOSE:To efficiently manufacture an equally conductive fiber base material by making a solution containing a conductive polymer-forming monomer and an oxidizer to pass through the fiber gaps of a fiber base material and coating the fiber surface with a conductive polymer. CONSTITUTION:A solution containing a conductive polymer-forming monomer and an oxidizer is made to pass through the fiber gaps of a fiber base material for coating the fiber surface with a conductive polymer. Aniline, thiophene, pyrrole or their derivatives are desirably used as a conductive polymer-forming monomer. In order to epitaxially grow a conductive polymer on the fiber surface, a conductive treating liquid is required to be passed through the fiber gaps. For that sake, a method of previously preparing a treating liquid, which contains a prescribed amount of monomers and an oxidizer, and making this treating liquid to pass through the fiber gaps, and a method of separately preparing a monomer solution and an oxidizer solution to pass the monomer solution through the fiber gaps and then to pass the oxidizer solution are used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a conductive fiber base material that enables mass production of conductive fiber base materials having uniform conductivity.

[Conventional technology]

The growth process of conductive polymers formed by oxidative polymerization of conductive polymer forms or monomers such as aniline, thiophene, pyrrole or their derivatives is called epitaxial growth.
Moreover, in view of the performance of the conductive polymer to be formed, it has been thought that it is best to carry out the oxidative polymerization of the conductive polymer-forming monomer as slowly as possible at a low temperature while leaving the aqueous solution still.

For this reason, conventionally, when forming a conductive polymer coating by oxidative polymerization of a conductive polymer-forming monomer on a fiber base material such as woven fabric, knitted fabric, non-woven fabric, or thread, it is necessary to simply contain the monomer and an oxidizing agent. The method used was to simply immerse the fiber base material in a conductive treatment solution and leave it to stand still. However, in such conventional methods, the concentration of monomers and oxidizing agent in the treatment solution is high at the initial stage, and since the treatment solution is left still, concentration unevenness occurs in the tank, resulting in rapid progress of the oxidative polymerization reaction. Fastness to friction, where the polymer progresses locally in the aqueous phase and tends to be suspended in the aqueous phase without effectively adhering to the fibers, and eventually forms particulate deposits that easily fall off from the fibers. Therefore, it was difficult to obtain a fiber base material having uniform conductivity.

As a result of intensive research to solve the above problems, the inventors of the present invention have discovered that the process is completely different from the conventional method of leaving the treatment liquid still, and by adopting a method in which the treatment liquid is actively brought into contact with the fiber base material, the process is surprisingly uniform. The present invention was completed by discovering that it is possible to efficiently produce a fiber base material having high conductivity.

[Means to solve the problem]

That is, the method for producing a conductive fiber base material of the present invention involves passing a solution containing a conductive polymer or a monomer and an oxidizing agent through the fiber gaps of the fiber base material, and coating at least the fiber surface with the conductive polymer. It is characterized by: In addition, in the present invention, an oxidizing agent solution is passed through the fiber gaps of the fiber base material after passing a conductive polymer forming monomer solution, or a heptanomer solution is passed after passing an oxidizing agent solution,
A method may be adopted in which at least the surface of the fibers is coated with a conductive polymer, in which an oxidizing agent is added to a conductive polymer or monomer solution and the solution is passed through the fiber gaps of the fiber base material. A method of coating the surface with a conductive polymer may also be adopted. In the method of the present invention, aniline, thiophene, pyrrole, or derivatives thereof are preferably used as the conductive polymer-forming monomer.

In the present invention, the fiber base material includes woven fabric, knitted fabric, nonwoven fabric,
Thread, etc. are used, and the fiber material is not particularly limited, and natural fibers and synthetic fibers such as cotton, hemp, vinylon, acetate, polyamide, acrylic, polyethylene, polypropylene, silk, rayon, and aromatic imide are used without distinction. can.

In the present invention, the conductive polymer forming monomers include aniline, 0-chloroaniline, m-chloroaniline, p
- Chloraniline, 0-methoxyaniline, m-methoxyaniline, p-methoxyaniline, 0-ethoxyaniline, m-ethoxyaniline, p-ethoxyaniline,
Aniline derivatives such as O-methylaniline, m-methylaniline and p-methylaniline; thiophene derivatives such as thiophene and 3-methylthiophene and 3-methoxythiophene; Substituted pyrrole, 3.4 monosubstituted pyrrole such as 1I 11 11 1I (However, in the above formula, φ represents a phenyl group.

) etc. (7) n-ip pyrrole (However, in the above formula, R1 is either a carbazole group, a phenothiazine group, or a birene group, R
2 represents an anthracene group, and R3 represents any one of a carbazole group, a phenothiazine group, and a dibenzophenazine group. )
, 3-monosubstituted pyrrole such as 3-methylpyrrole and 3-octylpyrrole.

As the oxidizing agent, any substance that promotes the polymerization of the above monomers can be used, such as permanganic acid or permanganates such as potassium permanganate, chromic acids such as chromic acid trioxide, nitrates such as silver nitrate, chlorine, Halogens such as bromine and iodine, peroxides such as hydrogen peroxide and benzoyl peroxide, peroxo acids and salts such as peroxonisulfuric acid and potassium peroxonisulfate, hypochlorous acid, potassium hypochlorite, etc. Oxygen acids and acid salts, ferric perchlorate, ferric chloride, ferric sulfate, ferric nitrate,
Examples include trivalent iron compounds such as ferric citrate, transition metal chlorides such as chloride, and metal oxides.These may be used alone or in a mixture of two or more, but they have good conductivity and transparency. From this point of view, trivalent iron compounds are preferred. The oxidizing agent is generally used in an amount of 2 moles or more per mole of monomer, and preferably 2 to 3 moles.

An aqueous solvent is usually used as a solvent for dissolving the monomer and oxidizing agent. Examples of the aqueous solvent include water, an organic solvent miscible with water, and a mixture of the organic solvent and water. Organic solvents that are miscible with water include methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, 130- Alcohols such as amyl alcohol, ethylene glycol,
Dipropylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, ethylene glycol monomethyl ether, ethylene glycol. glycols and their derivatives such as monoacetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, dioxane,
Ketones such as cyclohexanone, dimethylformamide, dimethyl sulfoxide, dimethylacetamide,
Examples include tetrahydrofuran and acetonitrile.

These can be used alone or in combination as appropriate.

In order to cause vertical crystal precipitation (evitaxial growth) of a conductive polymer on the fiber surface, it is necessary to pass a conductive treatment liquid through the gaps between the fibers. In the present invention, there are two methods: (1) preparing a treatment liquid containing a predetermined amount of a monomer and an oxidizing agent in advance, and passing this treatment liquid through the fiber gaps; and (2) preparing a monomer solution and an oxidizing agent solution separately and passing the treatment liquid through the fiber gaps. A method of passing the oxidizing agent solution after passing the monomer solution, or a method of passing the monomer solution after passing the oxidizing agent solution, and a method of passing the solution through the fiber gap while adding an oxidizing agent to the monomer solution. will be adopted. In method (2), the amount of conductive polymer suspended in the aqueous phase precipitated is smaller than in method (2) and is often more efficient. In addition, in this method, depending on the adsorption power of the monomer, oxidizing agent, etc. to the fiber material, the treatment with the monomer and oxidizing agent may be alternately repeated multiple times depending on the desired conductivity. At this time, it is not necessary that the monomer solution and the oxidizing agent solution pass through the fiber base material the same number of times. In method (2), the oxidizing agent concentration is lowered when the bath ratio is small, and the monomer can be oxidized and polymerized more uniformly.
Uniform conductivity can be imparted. In this method, all or a portion of the oxidizing agent is added to the monomer solution later, but when adding a portion later, the amount of oxidizing agent added in advance to the monomer solution is 172% of the total amount of oxidizing agent. ~2/3
It is preferable to set it as approximately. In addition, when the entire amount of the oxidizing agent is added later, it is not necessary to start adding the oxidizing agent to the monomer solution at the same time as the monomer solution is passed through the gap in the fiber base material. Addition of the oxidizing agent may be started later.

As a means of passing the treatment liquid through the fiber gaps, for example, the treatment liquid can be continuously and evenly spread on the fiber base material and the treatment liquid can be passed through the fiber gaps by its own weight, or the treatment liquid can be pressurized so as to pass through a filter. Means suitable for the above-mentioned methods (1) to (2) are adopted as appropriate from among means that can bring the treatment liquid into contact with the fiber base material while flowing it, such as passing through the gap between the fiber base materials under reduced pressure. 10d/g of treatment liquid to fiber base material
・Flowing at a speed of 1 minute or more is effective for uniform treatment.

For example, a cheese dyeing machine can be used to carry out the method of the invention. FIG. 1 shows an example using a cheese dyeing machine, in which a cylindrical bobbin 2 is provided in a processing tank 1, with one end a led out of the processing tank 1 and the other end b closed. The bobbin 2 has an inner diameter of 25 to 1 in which liquid passage holes 3 with a diameter of 3 to 1 lo are formed at a pitch of 3 to 10++n on its circumferential surface.
It is made of stainless steel, polypropylene, etc., and has an outer diameter of about 30 to 110 aan, and a fiber base material S is wound around the circumferential surface so as to cover the hole 3. To perform processing with this device, a processing liquid W is placed in a processing tank l in advance, and this processing liquid W is pumped into the bobbin 2 by a pump or the like.
Either the processing liquid W is caused to pass through the fiber base material S in the direction of arrow A by suctioning and discharging from one end a, or conversely, the processing liquid W is supplied from one end a of the bobbin 2 by a pump or the like and the processing liquid is passed through the fiber substrate S in the direction of arrow B. A method of passing the fiber base material S in the direction, a method of combining these methods, etc. are adopted. The treatment liquid W is a solution containing a monomer and an oxidizing agent when method (1) is employed, and is either a monomer solution or an oxidizing agent solution when method (2) is employed. In addition, when adopting method ■,
Either put a solution containing only monomer in the processing tank 1, and add the oxidizing agent solution into the processing tank 1 from the oxidizing agent supply port 4 while discharging and pressurizing this solution in the same manner as in method (2) above. Although not particularly shown, a processing liquid tank storing a monomer solution is separately provided, and while an oxidizing agent is added to the processing liquid tank, the processing liquid in the processing liquid tank is supplied from one end a of the bobbin 2 by a pump or the like. Although various methods may be mentioned, it is preferable to add the oxidizing agent at a point where the treatment liquid is flowing. In the process using the above-mentioned cheese dyeing machine, it is preferable to circulate the process liquid while discharging it from the process tank 1 or supplying it to the process tank 1. The oxidative polymerization reaction is different from a normal polymerization reaction, and the reaction proceeds extremely quickly even at low temperatures. Therefore, it is preferable to circulate a refrigerant through the jacket 5 to maintain the treatment liquid at as low a temperature as possible. is 5~30°C,
Particularly preferred is 15 to 25°C. If the temperature exceeds about 30°C, the polymerization rate becomes extremely high, and especially in the case of method (2), the oxidative polymerization reaction rate in the aqueous phase becomes higher than the vertical crystal precipitation rate on the fiber surface, which is not preferable. At low temperatures, the polymerization rate slows down, so more stable and high conductivity is imparted, but at temperatures below 0°C, problems such as freezing of the solution occur, so temperatures below 5°C are practically unfavorable. Furthermore, since the monomer is polymerized by air, it is preferable to perform the treatment in an inert gas atmosphere such as nitrogen gas to cut off the influence of air (oxygen) as much as possible, or to perform oxidative polymerization with dissolved oxygen removed. .

In order to impart uniform conductivity, monomers with low solubility in water, oxidizing agents, and polymerization products (especially low molecular weight initial polymerization products) are added to the treatment solution so that they are evenly adsorbed onto the fiber surface. It is preferable to use the monomer and oxidizing agent at low concentrations and keep the liquid flowing until the monomer disappears or the oxidizing ability of the oxidizing agent disappears. For this reason, it is preferable to circulate the treatment liquid and repeatedly pass it through the fiber gaps.
The flow rate of the treatment liquid and the flow rate in the fiber gaps are appropriately selected depending on the concentration of the monomer and oxidizing agent, the liquid temperature, the desired conductivity, and the like. As in the case of dye dyeing of fiber base materials, the larger the bath ratio, that is, the ratio of the weight of the treatment liquid to the weight of the fiber base material, the slower the conductivity rate (polymerization reaction rate), and the less the treatment liquid remains. Although the conductivity is slightly worse, extremely good and uniform conductivity is provided. The concentration of the monomer and oxidizing agent is 0.001 to 3 per 100 parts by weight of the solvent in the case of the above method
Part by weight, 0 for oxidizing agent. O O It is preferable to set it as about 1-30 parts by weight. Also, in the case of method (■), the monomer concentration in the monomer solution is the same as in the case of (■) above.
Per 100 parts by weight of solvent, 0. The amount of the oxidizing agent may be about 1 to 3 parts by weight, and the oxidizing agent to be added to this monomer solution may be added as is or as a solution dissolved in the same solvent as the monomer solution. In the case of method (2), the rate of addition of the oxidizing agent is determined by the flow rate of the treatment liquid to the fiber base material, the flow rate in the gap between the fiber base materials, the monomer concentration of the monomer solution,
Although it varies depending on the concentration of the oxidizing agent to be added, the bath ratio, etc., it is usually preferable to set the time to about 3 to 301.7 minutes, for example, when the bath ratio is in the range of 5:1 to 30:1 and the monomer concentration is 0.7 minutes. 1
It is preferable to prepare a solution with a concentration of about 5% and an oxidizing agent concentration of about 0.3 to 10%, and add it in small amounts over about 30 to 360 minutes. The oxidizing agent is added using a bomb or the like, but the addition method may be either intermittent dropwise addition or continuous addition. In addition, the oxidizing agent need not always be added in a fixed amount; for example, the oxidizing agent may be added so that the amount of one drop or the amount added per unit time gradually decreases (or increases), or the interval between drops is gradually increased. It is also possible to adopt a method of dropping the liquid so that it becomes longer (or shorter).

In the present invention, the conductive polymer is formed in some cases to cover the surface of the fiber base material, and in other cases it is formed in a composite manner with the fibers inside the fibers, but in reality, it is thought that both occur simultaneously. cannot be clearly distinguished. In addition, when analyzing the fiber surface after conductivity treatment with a scanning electron microscope, extremely fine cracks are often seen, indicating that the oxidation of the fiber polymer by the oxidizing agent and the oxidative polymerization reaction of the monomer occur almost simultaneously. It is thought that the cracking progresses, and it is thought that this cracking may greatly affect the adsorption of the heptanomer and polymer and the conductivity.

In the present invention, in order to further improve conductivity, halogens such as chlorine, bromine, and iodine, Lewis acids such as phosphorus pentoxide, hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, l,5-naphthalenesulfonic acid, and salicylic acid are used. Acids such as protonic acids such as acetic acid and benzoic acid, and their soluble salts can be added as dopants, and antioxidants and ultraviolet absorbers can be added in combination to improve the durability of conductivity. Also good. Further, a polymer layer of about 1 to 2 nm may be formed on the surface of the fiber base material by a spray method, dipping method, coating method, transfer method, etc. after conductive treatment within a range that does not impair the texture and conductivity of the fibers.

〔Example〕

Hereinafter, the present invention will be explained in more detail by giving Examples and Comparative Examples.

Example 1 Diameter of 200ttm and 250m as fiber base material
3. Wound 600 g of m-long vinylon yarn around the bobbin of the processing device shown in Fig. 1, and add 20 f of water and 1 pyrrole. 4 g, ferric chloride 6 4. 9 g of conductive treatment liquid, and the temperature of the treatment liquid was maintained at 18°C, and a certain amount of treatment liquid was added to prevent the yarn from being exposed to the surface of the treatment liquid in the treatment tank. At the same time, suction is applied with a pump from one end a of the bobbin, and while passing the processing liquid of 201 through the fiber gap (
direction of arrow A) was discharged to the outside of the treatment tank. Next, the processing liquid 201 was forced into the bobbin from one end a in the opposite direction, thereby passing the processing liquid in the direction of arrow B. This operation was one cycle, and when each cycle was repeated for 15 to 20 minutes for 3 hours, a black vinylon thread was obtained.

When the obtained vinylon yarn was dried and the surface resistance was measured, it was found that no matter which part of the yarn wound around the bobbin was measured, the resistance was 10'.
It was in the range of ~10'Ω/mouth and had uniform conductivity.

Example 2 In place of the vinylon yarn of Example 1, 210 denier, 70
Using 6-filament nylon thread, conductive treatment was performed in the same manner as in Example 1 to obtain a conductive nylon thread. The surface resistance value of the conductive nylon thread obtained was 103 to 10'Ω.
/ It had approximately uniform conductivity at the mouth.

Example 3 Using the same apparatus as in Example 1, a vinylon yarn wound around a bobbin in the same manner as above was put into a treatment tank together with a monomer aqueous solution consisting of 20N water and 3.4 g of pyrrole, and the monomer aqueous solution was discharged and press-fitted. The aqueous monomer solution was passed through the interstices of the fibers at a rate of 15 to 20 minutes/cycle for 2 hours. After draining the monomer aqueous solution in the treatment tank, an oxidizing agent aqueous solution in which 64.9 g of ferric chloride was dissolved in water 201 was passed through the fiber gaps in the same manner as above to obtain a conductive vinylon thread.

The obtained conductive vinylon yarn also has a surface resistance value of 105~
The conductivity was 10#'Ω/hole, and the conductivity was uniform no matter which part of the bobbin was measured.

Example 4 The order of passage of the treatment liquid in Example 3 was changed, and the oxidizing agent aqueous solution was first passed through the fiber gaps, the liquid was drained, and then the monomer aqueous solution was passed through to obtain a conductive vinylon yarn. It had uniform conductivity.

Example 5 150 denier, 4 day filament polyethylene terephthalate woolly textured yarn 1. 2 kg with a density of 0.
35 g/cc on a bobbin similar to that used in Example 1, and the bobbin was placed in a processing tank of a cheese dyeing machine with an internal volume of 1042 mm, and 26.8 g of pyrrole monomer was added thereto.
, 240 g of teri-butyl alcohol, 240 g of methyl alcohol, and 6000 g of water were added together with a monomer solution consisting of 240 g of teri-butyl alcohol, 240 g of methyl alcohol, and 6000 g of water, and the monomer solution was discharged from the processing tank and pressurized into the processing tank while maintaining the monomer solution temperature at 18°C.
After circulating the monomer solution for 10 minutes with a cycle of 2 minutes, 1500 g of an oxidizing agent aqueous solution with a liquid temperature of 20 ° C in which 1 mole of ferric chloride was dissolved was added to the monomer solution at a rate of 10 g/min, and the addition was completed. After that, the treatment solution was further circulated for 2 hours. After finishing the treatment, the thread was thoroughly washed with water, dried with ventilation at 60°C, and then wound back with a finish winding wine goo.It was found to be uniformly conductive all the way to the core, and its surface resistance value was 3.
．． It was 5×10”Ω/mouth.

Example 6 500 g of 1.5 denier, 51 mm long polyethylene terephthalate staple fiber was placed in a loose carrier, and 11.2 g of pyrrole monomer, ter-7'
160 g of methyl alcohol, 16 g of methyl alcohol
After circulating a monomer solution consisting of 0 g and 6000 g of water for 10 minutes under the same conditions as in Example 5, ferric chloride 6 7
．． 8 g of an oxidizing agent aqueous solution at a temperature of 15°C
g was added at a rate of 10 g/min, and after the addition was completed, the treatment solution was further circulated for 2 hours. After finishing the process, the thread was thoroughly washed with water, dried with ventilation at 60°C, and then rewound using wine goo for finishing winding, which revealed that the thread was evenly conductive down to the core.
Its surface resistance value was 8.5×10”Ω/hole.

Comparative Example The vinylon thread used in Example 1 and the nylon thread used in Example 2 were used to prepare a stainless steel cylinder with an inner diameter of 25ffIII1 and an outer diameter of 27 mm, in which holes of 1 mm in diameter were formed at a 5M pitch. It was wound in the same manner, immersed in 20ffi of the same treatment solution as in Example 1, and left standing for 16 hours while maintaining the solution temperature at 18°C.

Both the obtained vinylon yarn and nylon yarn had good surface resistance values on the wound surface and in the vicinity of the cylindrical hole.
All the surface resistance values in the inner portions were extremely poor.

[Effects of the Invention] The method for producing a conductive fiber base material of the present invention differs from the conventional method in which the fiber base material is simply immersed in a conductive treatment liquid and left to stand, in which the treatment liquid is actively applied to the gaps between the fibers. Since the fiber is allowed to pass through, the conductive polymer is efficiently crystallized on the fiber surface.
As a result, the bath ratio can be reduced, and since the treatment liquid comes into uniform contact with the fiber base material, an extremely uniform conductive fiber base material can be produced. Moreover, the electrical conductivity of the fiber base material can be easily controlled simply by adjusting the amount of treatment liquid passed through the fiber gaps.

Furthermore, if a method is adopted in which the monomer and the oxidizing agent are treated as separate solutions and individually passed through the fiber gaps, the amount of conductive polymer suspended in the aqueous solution can be extremely reduced.

Furthermore, if a method is adopted in which all or part of the oxidizing agent is added to the monomer solution while this solution is passed through the fiber gaps, uniform polymerization can be achieved even if the bath ratio is further reduced.
Uniform and good conductivity can be imparted.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of an apparatus used in the present invention.

Claims (4)

[Claims] (1) A conductive fiber base material characterized in that a solution containing a conductive polymer forming monomer and an oxidizing agent is passed through the fiber gaps of the fiber base material to coat at least the fiber surface with the conductive polymer. Production method. (2) Pass the conductive polymer-forming monomer solution and then the oxidizing agent solution through the fiber gaps of the fiber base material, or pass the oxidizing agent solution and then the monomer solution to at least coat the fiber surface. A method for producing a conductive fiber base material, the method comprising coating it with a conductive polymer. (3) A conductive fiber characterized in that an oxidizing agent is added to a conductive polymer-forming monomer solution and the solution is passed through gaps between fibers of a fiber base material, so that at least the fiber surface is coated with a conductive polymer. Method of manufacturing base material. (4) The conductive fiber base material according to any one of claims 1 to 3, wherein the conductive polymer-forming monomer is a monomer selected from the group consisting of aniline, thiophene, pyrrole, or derivatives thereof. manufacturing method.