JPH0261175A - Production of electrically conductive polymer formed article - Google Patents

Abstract

PURPOSE:To obtain the subject formed article having excellent durability and stability by absorbing an oxidizing agent into a formed fiber article having low orientation and a birefringence smaller than the specific level, drawing the article to form a highly oriented article, absorbing a monomer of an electrically conductive polymer into the oriented article and polymerizing the monomer to form an electrically conductive polymer. CONSTITUTION:An oxidizing agent (e.g., ferric chloride or bichromate) is absorbed in a low-orientation formed article of a melt-formed fiber composed of a polyester or polyamide and having a P value (defined by the formula) of <=0.35. The article is drawn to form a highly oriented article, which is made to contact with a monomer (e.g., vapor of a monomer) capable of forming an electrically conductive polymer by oxidative polymerization (e.g., pyrrole or thiophene). The monomer absorbed in the article is polymerized to form an electrically conductive polymer in the formed article and obtain the objective formed article of an electrically conductive polymer. The process is used widely for the production of an electrically conductive fiber, film, sheet, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing a conductive polymer molded article. More specifically, the present invention relates to a method for producing a conductive polymer molded article in which an organic conductive polymer is produced by chemical oxidative polymerization inside a highly oriented polymer molded article such as fibers and films that require excellent mechanical properties.

<Prior Art> It has been known that pyrrole, thiophene, aniline, derivatives thereof, and the like can be chemically oxidized and polymerized to produce polymers with good conductivity. However, since the conductive polymers obtained by such conventional methods are in powder form, they must be further molded into a shape suitable for the purpose before use, but these polymers are generally insoluble and infusible. Therefore, it had the disadvantage of being extremely difficult to mold.

It is also known to electrochemically oxidize and polymerize the above-mentioned pyrrole, thiophene, aniline, etc. to form a film-like conductive polymer on the electrode plate. However, it has been difficult to obtain a sheet, but its mechanical properties are insufficient, and it is difficult to obtain a sheet having a form other than a film, such as a fibrous form. In order to improve this drawback, various methods have been proposed in which a polymer with good moldability is combined with the conductive polymer. For example, an insulating film is formed on the electrode by a casting method, or a separately formed insulating film is brought into close contact with the electrode, and then pyrrole is electrochemically oxidized and polymerized in an electrolytic bath (Proceedings of the Society of Polymer Science and Technology). Shuyu 3 48
44-845), a method of dispersing a powdery conductive polymer obtained by chemical oxidative polymerization into a polymer with good moldability, and molding and shaping it; by contacting a low-molecular compound that forms a polymer,
A method for producing a conductive polymer in a molded product and its reverse method (JP-A-61-111336, JP-A-61
-282479) etc. have been proposed.

However, conventional methods of combining conductive polymers and polymers with good moldability have serious drawbacks, and none of them are satisfactory. Although the method of oxidative polymerization of virol improves mechanical properties, the shape of the conductive polymer obtained is limited to a film-like shape and it is difficult to obtain a 411 fiber-like material. This method has many disadvantages, such as the fact that almost no chemical polymer is produced, and furthermore, the operation is troublesome and special equipment such as electrodes is required.

The method of dispersing a conductive powdered polymer into a polymer with good moldability and molding and shaping requires dispersing 25% or more of the conductive polymer into the polymer in order to develop conductivity. However, moldability is extremely poor, mechanical properties are extremely inadequate, and special measures such as composite spinning and film lamination are required to obtain satisfactory molded products. It has disadvantages such as:

According to studies conducted by the present inventors, various methods of bringing a monomer forming a conductive polymer into contact with a molded article containing a chemical oxidizing agent have various drawbacks. In other words, a wet-dry method in which a chemical oxidizing agent is added to the polymer molded product in advance (
For example, the polymer is dissolved and a chemical oxidizing agent is dissolved in the solution beforehand, and then the fibers are spun and formed into a film by dry spinning, casting, etc.)
When trying to apply it to commonly used polymers with good mechanical and chemical performance (e.g. polyethylene terephthalate, polybutylene terephthalate, polylactam, etc.), the solvent is extremely difficult to handle. and,
The mechanical properties of the molded product thus obtained also had the drawback of being extremely inadequate.

Adding a chemical oxidizing agent to the polymer and then melt-molding it may result in insufficient thermal stability of the chemical oxidizing agent, the chemical oxidizing agent not being sufficiently uniformly dispersed in the polymer, or problems occurring during melt-molding. It has the disadvantage that stable melt molding is difficult because the chemical oxidant sublimes and scatters. In addition, the method of impregnating a chemical oxidizing agent into a molded product after melt molding has good electrical conductivity when applied to a low-oriented molded product, but the mechanical performance of the final molded product is insufficient. On the contrary, it has been found that when applied to highly oriented molded products in order to satisfy mechanical properties, there is a drawback that it is difficult to obtain sufficient electrical conductivity. Furthermore, after stretching the molded product with good conductivity obtained from the low-oriented molded product, the stretchability becomes extremely poor after forming a conductive polymer in the molded product, and the mechanical performance cannot be sufficiently improved. It was also found that it was not possible to obtain the desired stretching ratio, or that the conductivity was completely lost if stretched forcibly. There is also a method in which a conductive polymer is formed inside a highly oriented molded product by contacting
When ammonium chromate persulfate, dichloromethane, etc. are used as a chemical oxidizing agent, a molded article with good conductivity cannot be obtained, and only when iodine is used, conductivity is improved. However, even in this case, the durability stability of the obtained conductivity was insufficient, and the conductivity deteriorated when exposed to a heated aqueous alkaline solution or subjected to dry heat treatment.

In this way, a conductive polymer is produced in the 1ti fiber-forming body molded product, and the conductivity is so good that it can be put to practical use.
The reality is that durability stability and mechanical performance cannot be satisfied at the same time.

<Object of the Invention> The present invention eliminates the drawbacks of the conventional methods for producing conductive molded articles, and provides a conductive polymer molded article that has excellent conductive performance and durability, and has extremely good mechanical performance. The objective is to provide a new manufacturing method that provides the following.

<Structure of the Invention> As a result of intensive studies to achieve the above object, the present inventors found that a low-oriented molded product impregnated with a chemical oxidizing agent after melt molding is almost the same as one that is not impregnated. Although the molded product thus obtained is highly oriented, when it comes into contact with the monomer that forms the conductive polymer, the conductive polymer can be efficiently molded into a highly oriented polymer. The present invention was achieved by discovering that it is generated inside objects.

That is, in the present invention, a chemical oxidizing agent is absorbed into a melt-molded low-oriented molded product having a P value of 0.35 or less made of fiber-forming polyester or polyamide, and then a stretching treatment is performed to obtain a highly oriented molded product. A conductive polymer molded product, characterized in that a monomer that becomes a conductive polymer through oxidative polymerization is contacted and absorbed into the post-filled molded product to produce a conductive polymer in the molded product. This is a manufacturing method.

P-Δn/Δnt The fiber-forming polyester or polyamide that is the base material of the conductive polymer molded product of the present invention is formed into a desired shape by melt molding, and then subjected to a stretching treatment, so that the molecular chains are highly Any polyester may be used as long as the mechanical performance is significantly improved by orientation. Examples of the polyester include alkylene terephthalates such as polyethylene terephthalate, polybutylene terephthalate, and polyhexamethylene terephthalate; polyethylene naphthalate;
Polyalkylene naphthalates such as polybutylene naphthalate, polyethylene oxybenzoate, and small amounts of copolymerized components such as isophthalic acid, adipic acid, 5
- Examples include polyesters copolymerized with sodium sulfoisophthalic acid, polyethylene glycol, etc.
Examples of polyamides include polyhexamethylene adipamide.

Examples include aliphatic polyamides such as polytetramethylene adipamide and polyglolactam.

Among these, the electrical conductivity of the final molded product.

From the standpoint of thermal and mechanical performance, polyesters are preferred, especially polyethylene terephthalate or polybutylene terephthalate.

In the present invention, it is necessary to first melt-mold such a polymer to form a molded product with a low degree of orientation.

Here, the low degree of orientation varies depending on the type of polymer used, but the birefringence of the molded product is △n1 A single 10-denier unoriented undrawn yarn made of the polymer is stretched at break at the glass transition temperature. When the birefringence when stretched to 0.95 times the magnification is 80 (for example, polyethylene terephthalate Δnt = 0.18. Polybutylene terephthalate Δnt
= 0.16), the value of P expressed by the following formula is 0.35 P - Δn/Δnt or less, and the molded product with a high degree of orientation in which this P value exceeds 0.35 will be described later. At the stage of absorbing the chemical oxidizing agent, it may not be possible to absorb the amount of chemical oxidizing agent necessary to impart the required conductivity to the final molded product, or the conditions for absorption may be extremely poor. This is undesirable because it must be made into a harsh material.The shape of the molded product must have a strength of 2 after absorbing the chemical oxidizing agent.
Modulus of elasticity.

Any form may be used as long as it can be stretched to improve dimensional stability, etc., but the effects of the present invention are particularly large in cases of highly oriented forms such as fibers and films. preferable.

In the present invention, it is necessary to absorb a chemical oxidant before stretching the low-oriented molded product, but after partially stretching the above-mentioned P value within the range of 0.35 or less, the chemical oxidant is absorbed. The film may be absorbed and then stretched again.

As the chemical oxidizing agent used in the present invention, any chemical oxidizing agent can be used as long as the redox potential under the conditions for polymerizing the organic low-molecular compound that forms the @electroconductive polymer described below is higher than the oxidative polymerization initiation potential. can be used. Examples of such chemical oxidizing agents include (1) ferric chloride, ferric nitrate, ferric sulfate, ferric citrate, ferric phosphate, and ferric perchlorate.

Trivalent iron compounds such as potassium ferricyanide (2) Hexavalent chromium compounds such as potassium dichromate and chromic anhydride (a) Manganese compounds such as potassium permanganate and sodium permanganate (4) Ammonium persulfate, persulfate Persulfate compounds such as sodium and potassium persulfate (5) Nitrous acid, sulfurous acid, hydrogen peroxide solution 1 Sodium hypochlorite, potassium hypochlorite, etc. can be mentioned, and may be used alone, Among these chemical oxidizing agents, which may be used in combination of two or more types, trivalent iron compounds, especially ferric chloride, penetrate well into molded products, so they improve the conductivity of the final molded product. This is preferable because it improves properties and durability and stability.

It should be noted that chemical oxidizing agents act as oxidizing agents to form conductive polymers, and at the same time, they also act as dopants to improve the conductive performance of conductive polymers. Iron is preferred.

The method of absorbing the chemical oxidizing agent into the molded article with a low degree of orientation does not need to be particularly limited, but the simplest method is, for example, to dissolve the chemical oxidizing agent in an appropriate solvent and add the molded article to this solution. An example is a method of immersing. A suitable solvent is one that dissolves the chemical oxidizing agent and does not substantially soak the shape of the polymer molded article, such as water.

The type and chemistry of the polymer from among alcohols, esters, ketones, aromatic hydrocarbons, aliphatic hydrocarbons, organic acids, organic acid amides, ethers, organic nitro compounds, organic nitrile compounds, etc. It may be selected appropriately depending on the type of oxidizing agent.

Further, two or more of these may be used in combination.

When using polyethylene terephthalate as the polymer and ferric chloride as the chemical oxidizing agent, acetone or tetrahydrofuran are used as suitable solvents.

The conditions for absorbing the chemical oxidizer into the molded product are the type of polymer, the degree of orientation of the molded product, and the shape of the molded product.

Although it varies depending on the type of chemical oxidizing agent, type of solvent, etc., the concentration of the chemical oxidizing agent processing liquid and the processing temperature.

It can be easily absorbed by appropriately changing the treatment time and the like. In addition, by appropriately selecting these conditions, it is possible to change the state of penetration of the chemical oxidant into the molded product, and the conductive polymer produced inside the final molded product can be transferred to the surface layer of the molded product. It is possible to increase the amount in a certain area or to make it almost uniform throughout the molded product.

Note that after performing this treatment, it is preferable to wash the surface with a solvent in order to remove the chemical oxidizing agent adhering to the surface.

In the present invention, the stretching treatment is performed to improve the mechanical performance, dimensional stability, etc. of the molded product, but a conductive polymer-forming monomer is also used to impart conductivity to the molded product, which will be described later. This must be done before contacting the body. If a conductive polymer is formed before stretching, this polymer will have almost no stretchability, which is undesirable because the molded product will crack and lose its conductivity at all, or the molded product will break during stretching.

To stretch a molded product that has absorbed a chemical oxidizing agent, it is sufficient to stretch it in the fiber axis direction if the molded product is fibrous, or uniaxially or biaxially if it is a film. In order to sufficiently improve the mechanical performance of an object, it is necessary to achieve a high degree of orientation, and when a low-orientation molded object treated with a processing solution that does not contain a chemical oxidant is stretched under the same conditions as those under which the chemical oxidant was absorbed. , the aforementioned P value is at least 0
．． It is necessary to carry out the stretching process under the same conditions as those for obtaining 70 or more. The stretching temperature is usually preferably higher than or equal to the glass transition point or lower than the melting point of the polymer constituting the molded article, but if the decomposition temperature of the absorbed chemical oxidant is lower than the glass transition point of the polymer, or the glass transition point If the chemical oxidizing agent is extracted from the inside of the molded product at a temperature close to , it is acceptable to stretch at a temperature below the glass transition point.

Although many monomers that undergo oxidative polymerization to form conductive polymers are known, any of them can be suitably used in the present invention. Examples of such monomers include pyrrole and its derivatives, thiophene and its derivatives, aniline and its derivatives, and the like.

As pyrrole derivatives and thiophene derivatives, 2.
Those containing no substituent at the 5-position are used, and as aniline derivatives, those containing no substituent at the rose position are used.

Specifically, the pyrrole derivatives include N-methylpyrrole, N-ethylpyrrole, 3-methylpyrrole, 3.
Examples include 4-dimethylpyrrole and N-phenylpyrrole. As a thiophene derivative, 3-methylthiophene.

Examples include 3,4-dimethylthiophene, and 2,2°-bithiophene, which is a dimer of thiophene, is also preferably used. Also, examples of anilines include N-methylaniline, N-ethylaniline, N-butylaniline, N-phenylaniline, 0- and m-toluidine, 0- and m-anisidine, and N- and m-chloroaniline. Examples thereof include aniline and its derivatives having substituents at the ortho and/or meta positions, and salts thereof. These may be used alone or in combination of two or more.

These monomers form a polymer by undergoing chemical oxidative polymerization, and at the same time are doped with a chemical oxidizing agent to coordinate anions to become a conductive polymer. It is also possible to improve the conductivity and stability of these conductive polymers by adding a dopant or substituting a dopant.

There is no particular limitation on the method of bringing such a monomer into contact with the oriented molded product that has been subjected to the stretching treatment to produce a conductive polymer in the molded product. The contact may be carried out without a solvent, or with a suitable solvent such as water or alcoholic acid.

It may be dissolved in and brought into contact with esters, getones, aromatic hydrocarbons, aliphatic hydrocarbons, organic acids, ethers, R acid amides, organic nitro compounds, organic nitrile compounds, etc., or If the monomer can be gasified, its vapor may be brought into contact. Furthermore, a dopant may be present in order to improve the conductivity of the resulting conductive polymer molded product.

Treatment conditions for bringing the monomers into contact to produce a conductive polymer, such as the concentration of the monomers in the treatment liquid.

The distribution of the conductive polymer produced inside the molded article can be adjusted as desired by the treatment temperature and treatment time, as well as by the type of polymer used and its degree of orientation. That is,
A larger amount of the conductive polymer can be produced in the surface layer of the molded article, or it can be produced almost uniformly over the entire molded article.

The required amount of the conductive polymer to be formed in the molded article varies depending on the type of the conductive polymer and the distribution state inside the molded article, but it is usually 1 to 1 % based on the weight of the molded article.
00% by weight, preferably 3 to 50% by weight. If the conductivity of the resulting conductive polymer is less than 1% by weight, sufficient conductivity will not be obtained, while if it exceeds 100% by weight, it will not be obtained. Not only does the conductivity reach saturation and no further improvement occurs, but it is also undesirable because it impairs the mechanical performance of the final molded product.

Note that in order to adjust the amount of conductive polymer to be produced, the amount of the chemical oxidant mentioned above absorbed may be changed, or the conditions under which the monomers are brought into contact may be adjusted, but the amount of the former may be adjusted. It is preferable to do so because it is easier.

In the present invention, in order to improve the dimensional stability and mechanical performance of the molded product, it is desirable to perform a heat treatment.If the heat treatment is performed after the stretching treatment, the heat treatment can be performed either before or after contacting the monomers. However, the heat treatment conditions such as treatment temperature and treatment time can be arbitrarily selected as long as the chemical oxidizing agent used and the produced conductive polymer stably exist.

<Effects of the Invention> As described above, by producing a conductive polymer inside a conventionally highly oriented polyester or polyamide molded product,
It has been difficult to impart conductivity with good durability and stability, but according to the production method of the present invention, it is extremely easy to produce conductive polymers in any amount and in any distribution state. I can do it.

The molded product thus obtained has durable and stable conductivity and good mechanical properties, and can be applied to a wide range of uses such as conductive fibers, conductive films, and conductive sheets.

Although the present invention has been described in detail above, the present invention includes the following aspects.

(1) A method for producing a conductive polymer molded product according to the claims, wherein the low-orientation molded product is made of fiber-forming polyester.

(2) A method for producing a conductive polymer molded article according to the claims, wherein the low-orientation molded article is made of polyethylene terephthalate or polybutylene terephthalate.

(3) The method for manufacturing a conductive polymer molded product according to claim 1 or (1) or (2) above, wherein the chemical oxidizing agent is a trivalent iron compound.

(4) The method for producing a conductive polymer molded article according to (3) above, wherein the chemical oxidizing agent is ferric chloride.

(5) The method for producing a conductive polymer molded article according to any one of claims or (1) to (4) above, wherein the monomer that becomes a conductive polymer through oxidative polymerization is pyrrole.

<Examples> The present invention will be explained in more detail with reference to Examples below. Note that the following items in the examples are values determined by measurement as follows.

△n: Na-D line (λ=5
Measured under a light source of 89 r+n).

Amount of conductive polymer produced: Calculated from the weight increase of the conductive polymer molded product obtained.

Electrical resistance value: The resistance value per 10 fibers was determined from the resistance value under IKV load.

Washing resistance Using 1.0% by weight of nonionic household detergent Monogen Uni (manufactured by Brocter & Gamble Far East), the product was washed with stirring at 50°C for 40 minutes, and the electrical resistance value was measured after washing with water for 5 minutes twice. did.

Hot water resistance: The electrical resistance value was measured after being exposed to hot water at 130°C for 60 minutes.

Dry heat resistance: The electrical resistance value was measured after heat treatment with a hot air drying cloth at 180°C for 60 seconds.

Alkali resistance: The electrical resistance value was measured after being immersed in a 5 tr/1 sodium hydroxide aqueous solution at 20°C for 60 minutes or at 100°C for 120 minutes.

The undrawn yarn (△n0
101 or less, P=0.06 or less, single yarn 11 denier)
I got it. This undrawn yarn 1. Og was wound into skeins, treated with ferric chloride hexahydrate in acetone 7B solution (weight ratio 1:1) for 24 hours at room temperature, washed with water, and dried.

Then, after stretching 4 times at room temperature (Δn = 0.15 when stretched without impregnating with ferric chloride. P = 0.8
3) The sample was left standing in pyrrole vapor at room temperature for 24 hours.

The obtained yarn was washed with water and then dried to obtain a treated system with a single yarn fineness of 3 denier.The weight increase of this treated system was 10% and the electrical resistance was 1 x 106 Ω/■.

In addition, the durability of washing resistance, hot water resistance, dry heat resistance, and alkali resistance was also good as shown in Table 1.

Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.64 was extruded at 285° C. through a die with a pore diameter of 0.3+++w+ and a number of holes of 24, and was first dried. The resulting treated system was hardly colored, and no formation of conductive polymer was observed. Further, the electrical resistance was 10 IOΩ/■ or more, and there was no conductivity at all.

Comparative Example 2 An undrawn yarn impregnated with ferric chloride obtained in the same manner as in Example 1 was left standing in virol vapor at room temperature for 24 hours. The weight increase of this treatment system is 10%, and the electrical resistance is 106Ω/
It was cIll. However, the electrical resistance of the drawn yarn obtained by drawing the obtained treatment system four times was 10 IOΩ/mouth or more, and had no conductivity at all.

Comparative Example 1 An undrawn yarn obtained in the same manner as in Example 1 was stretched 4 times at 70° C. to obtain a drawn yarn with a single yarn denier of about 2.8 denier.

This drawn yarn was treated with an acetone solution of ferric chloride in the same manner as in Example 1, washed with water and dried, then left to stand in virol steam for treatment, washed with water and dried.Comparative Example 3 Ferric chloride acetone solution treatment A treatment system was obtained in the same manner as in Example 1, except that the undrawn yarn was treated with pyrrole steam treatment and the treatment after stretching was treated with ferric chloride acetone solution. The electrical resistance of this treatment system is 5.0
X10"Ω/cII and conductivity were poor.6 Examples 2 and 3. Comparative Example 4.5 The conditions for treatment with ferric chloride acetone 7B solution were changed as shown in Table 2. In the same manner as in Example 1, treatment systems were obtained in which the amount of conductive polymer produced was varied.

The electrical resistance value and yarn strength of these treatment systems are combined to
Shown in the table.

Example 5 A treatment system was obtained in the same manner as in Example 1 except that the treatment was performed with the chemical oxidizing agent shown in Table 3. Table 3 shows the results of the weight increase and electrical resistance value of the treatment system obtained.

Table 3 Table 2 *rec13 - 6H20 acetone Example 6 Polybutylene terephthalate with an intrinsic viscosity of 0.88 was extruded at 265°C from the same die used in Example to form an undrawn yarn ( Δn<0.01. P<0.06. Single yarn 11
denier). This undrawn yarn was subjected to ferric chloride treatment, 4 times stretching, and virol steam treatment in the same manner as in Example 1. The electrical resistance values of this treatment system are shown in Table 4.

A treated system was obtained in the same manner as above except that nylon-6 was used instead of polybutylene terephthalate and the spinning conditions were changed as shown in Table 4. The electrical resistance values of this treatment system are also shown in Table 4.

Example 7 A treatment system was obtained in the same manner as in Example 1, except that the monomers listed in Table 5 were used instead of virol as monomers that would become conductive polymers through oxidative polymerization.

Table 5 shows the weight increase and electrical resistance value of this treatment system.

Table 5 Table 4 Comparative Example 6 An undrawn polyethylene terephthalate yarn obtained in the same manner as in Example 1 was stretched 4 times at 70°C to obtain a single yarn denier of 2.
A drawn yarn of 8 denier was obtained.

1 g of this drawn yarn was wound into a skein and treated with 300 ir of iodine.

300g of potassium iodide to 1 part of water! The sample was immersed for 30 minutes in an aqueous solution at 70° C., washed with water, and dried overnight. This thread was treated by leaving it in virol steam at room temperature for 24 hours, then washed with water and dried. The weight increase of this treatment system was 4%, and the electrical resistance value was good at 1.4×10 6 Ω/am. However, this treatment system was inferior in terms of dry heat resistance and alkali resistance as shown in Table 6.

Table 6

Claims (1)

[Claims] A chemical oxidizing agent is absorbed into a melt-molded low-oriented molded product made of fiber-forming polyester or polyamide and has a P value of 0.35 or less, and then subjected to a stretching treatment to form a highly oriented molded product. A conductive polymer characterized in that a conductive polymer is produced in the molded product by contacting and absorbing a monomer that becomes a conductive polymer through oxidative polymerization into the molded product. Method for manufacturing molded products. P=Δn/Δn_t However, Δn: Birefringence of low-oriented molded product Δnt: Birefringence when a single 10-denier unoriented undrawn yarn is stretched at glass transition temperature to 0.95 times the stretching ratio at break.