JPH07254307A - Conductive polymeric composition - Google Patents

Abstract

PURPOSE:To provide high moldability and electrical conductivity by doping an oxidizing dopant into a high molecular compound containing silicon blended with an amine compound. CONSTITUTION:A high molecular compound containing silicon and an amine compound are dissolved and mixed in a solvent ensuring the the solubility thereof and, then, molded, while the solvent being vaporized. Furthermore, the mixed compounds are molded, while the solvent being rotated at high speed, thereby providing a thin film and electrically conductive material. Also, the compounds after mixed are shelved at room temperature and kept in standing state in dry environment and fed with a dopant. As a result, the high molecular compound containing silicon, regardless of the inherent insulating quality thereof, is improved in terms of electrical conductivity, when doped with an oxidizing dopant. At the same time, a material held in stable state can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly conductive conductive polymer composition having excellent shapeability.

[0002]

2. Description of the Related Art In recent years,
Conducting organic polymer compounds have attracted attention since it has been found that when polyacetylene is doped with an electron-accepting substance or an electron-donating substance, a charge-transfer formation reaction occurs and high electrical conductivity based on electron conduction is expressed. There is. Representative examples of such organic polymer compounds include polyacetylene, polyphenylene, polypyrrole, polyphenylene vinylene, polyaniline, polythiophene and the like.

However, these polymer compounds have poor shapeability because they are insoluble and infusible, the shape of the film produced by the gas phase polymerization method or the electrolytic polymerization method is restricted by the shape of the reaction vessel or the electrode, and the doping. At times, it was accompanied by significant deterioration, which was a practical obstacle.

On the other hand, polysilane is a polymer which is very interesting in comparison with carbon because of its metallicity and electron delocalization of silicon, high heat resistance and flexibility, and good thin film forming characteristics. Was almost unknown. Slightly, West et al. By doping the polymer compound of polysilastyrene system with SbF _5, AsF fluorine compounds such as _5, but to obtain a polymer compound of high conductivity, high toxicity handle even complicated dopant Was required (R.
West, et. al. J. Am. Chem. So
c. , 103, 7352 (1981)).

For this reason, it has been desired to dope with iodine or ferric chloride, which is safer and easier to handle, but a satisfactory high-conductivity conductive polymer compound has not always been obtained.

The present invention has been made in order to overcome these drawbacks, and is a conductive polymer composition having excellent shapeability and giving high conductivity by doping with an oxidizing dopant such as iodine or ferric chloride. The purpose is to provide things.

[0007]

Means and Actions for Solving the Problems The present inventors have
As a result of intensive studies to achieve the above object, a silicon-containing polymer compound containing an amine compound is soluble in a solvent, can be formed into a film or coating film of any shape, and is doped with an oxidizing dopant. It has been found that, by doing so, a highly conductive polymer is obtained in which the conductivity is remarkably improved and the flexibility is maintained without becoming brittle after doping. Then, the composition obtained by doping the silicon-containing polymer compound containing the amine compound obtained by the present invention can easily obtain a highly conductive film or coating film having excellent shapeability, battery electrode, solar cell, It is a useful material that can be applied to the housing for electromagnetic shield, etc.
Knowing that it is widely used in the fields of electricity, electronics, and communication,
The present invention has been completed.

The present invention will be described in more detail below. The conductive polymer composition of the present invention is obtained by doping a silicon-containing polymer compound containing an amine compound with an oxidizing dopant.

Here, as the silicon-containing polymer compound, one having a Si-Si bond in the main chain or S in the main chain is particularly preferable.
Those having an i-Si bond and a C-C multiple bond are preferable,
More specifically, polymer compounds such as polysilanes, poly (disilanylene phenylene) s, and poly (disilanylene ethynylene) s can be mentioned.

In this case, the polysilanes are represented by the general formula (1) or
Is represented by (2), poly (disilanylene phenyl)
Lens) and poly (disilanylene ethynylene) s have the general formula
Those represented by (3) are preferably used. (R¹R²Si)_n … (1) (R¹R²Si)_n(R³R^FourSi)_m … (2) [(R¹R²Si) -A- (R³R^FourSi) ]_m … (3)

However, R ^{1 to} R ⁴ are each a hydrogen atom or an unsubstituted or substituted monovalent hydrocarbon group having 1 to 14 carbon atoms, particularly 1 to 10 carbon atoms, and an alkyl group such as methyl, ethyl, propyl or hexyl, Examples thereof include an aryl group such as a phenyl group, a substituted aryl group such as an alkyl-substituted phenyl group, and a cycloalkyl group such as cyclohexyl. In addition, R ¹ ~
R ⁴ may be the same or different from each other.

Further, A is ortho, meta or para position substituent of the phenylene group (-C ₆ H ₄ -), an acetylene group (-C≡C
-) Or a combination of a plurality of these groups (for example,-
C≡C—C ₆ H ₄ —C≡C—, etc.).

Further, n is an integer of 2 or more, preferably 10
~ 1,000,000, more preferably 50-500,
000 and m is an integer of 1 or more, preferably 1 to 1,
, 000,000, more preferably 50 to 500,000
And the number average molecular weight of the silicon-containing polymer compound is usually in the range of 300 to 30,000,000, particularly 1,5.
It is preferably in the range of 00 to 1,500,000.

The silicon-containing polymer compound can be synthesized by a known method, and can be easily produced, for example, by subjecting the corresponding dichlorosilane or the like to a wurtz-type condensation reaction with an alkali metal.

On the other hand, as the amine compound, those having the following general formula (4) or (5) are preferably used. NR ⁵ R ⁶ R ⁷ (4) R ⁸ R ⁹ N-R ¹⁰ -NR ¹¹ R ¹² (5)

However, R ^{5 to} R ⁹ and R ¹¹ R ¹² are each a hydrogen atom or a monovalent organic group having 1 to 24 carbon atoms, particularly 1 to 20 carbon atoms, and specifically, methyl, ethyl, propyl and hexyl. Alkyl groups such as, aryl groups such as phenyl groups,
A substituted aryl group such as an alkyl-substituted phenyl group, an aralkyl group such as benzyl or phenethyl, an unsubstituted or substituted monovalent hydrocarbon group such as a cycloalkyl group such as cyclohexyl, or an NN-bond-unsubstituted or substituted monovalent hydrocarbon group. Examples thereof include a valent hydrocarbon group. In addition, R ^{5 to} R ⁷ and R ⁸ ,
R ⁹ , R ¹¹ and R ¹² may be the same or different from each other.

R ¹⁰ has 1 to 24 carbon atoms, especially 1 to 2 carbon atoms.
A divalent hydrocarbon group of 0, an alkylene group or a cycloalkylene group having 1 to 8 carbon atoms, such as methylene or ethylene, or a cycloalkylene group having 1 to 6 carbon atoms, an arylene group having 6 to 12 carbon atoms such as phenylene, an alkylene group or a cycloalkylene. Examples thereof include a group in which an arylene group is present between the groups, and an group in which an alkylene group and a cycloalkylene group are interposed between the arylene groups.

As the amine compound, a tertiary amine is particularly preferable from the viewpoint of miscibility with a silicon-containing polymer compound. Further, those having an aromatic ring such as triphenylamine, an arylamine represented by the following formula, an amino group-substituted vinyl compound, and an amino group-substituted hydrazone compound are also effectively used.

[0019]

[Chemical 1]

The compounding amount of the above amine compound varies depending on the kind of the amine compound and the kind of the silicon-containing polymer compound, but is 1 to 100 parts by weight of the silicon-containing polymer compound.
200 parts by weight, more preferably 5 to 100 parts by weight is preferable, and if the amount is smaller than this amount, the effect of improving the conductivity when doping is not sufficient, and the addition of more than this amount has the effect of improving the conductivity. The negative effect is that the film-forming property deteriorates.

The silicon-containing polymer compound and the amine compound can be mixed by mechanically kneading them,
When more uniform mixing is desired, a method of dissolving the both in a solvent in which both are soluble and mixing and then molding while evaporating the solvent can be adopted as necessary. In particular, in order to obtain a thin film conductive material, a spin coating method in which this solvent is molded while rotating at high speed is preferably used.

In this case, examples of the solvent include benzene and
Aromatic hydrocarbons such as toluene and xylene, and ether solvents such as tetrahydrofuran and dibutyl ether are preferably used. After mixing the silicon-containing polymer compound and the amine compound, it is also effective to leave them in a dry atmosphere for a while (nesk) or leave them at a temperature of about 40 to 60 ° C. (aging). It should be noted that, after mixing the silicon-containing polymer compound and the amine compound, the mixture is mixed at room temperature for 3 to 20 minutes.
The conductivity can be improved by leaving it for about a day and then performing doping. In this case, the standing time is shortened by raising the temperature, but it is not preferable to raise it to 150 ° C. or higher because the polymer is deteriorated.

In the present invention, the silicon-containing polymer compound containing the amine compound is doped with an oxidizing dopant. That is, the silicon-containing polymer compound is generally an insulator as it is, and iodine, sulfuric acid or Sb
It has already been known that doping with a fluorine compound such as F ₅ or AsF ₅ results in a conductive polymer, but the conductivity is not sufficient, and the amine compound-added silicon-containing polymer compound according to the present invention is used. By doping with an oxidative dopant, it is possible to obtain a material in which good conductivity is stably maintained. An example in which such an amine compound is blended with polysilane and the hole mobility is measured by Yokoyama et al. (M. Yokoyama et al., J.
C. S. Chem. Common. , 1990, 80
2: M.I. Stolka et al. , Synth. M
et al. , 54, (1) 417), but there is no mention of improving conductivity by doping.

As the oxidative dopant for making the silicon-containing polymer compound added with the amine compound conductive,
Halogen such as chlorine, bromine, iodine, tin chloride, transition metal chlorides such as ferric chloride, antimony pentafluoride, Lewis acid such as arsenic pentafluoride are effective, but safe and handle Doping with iodine or ferric chloride, which is easy to do, is particularly desirable. The doping method includes (1) so-called vapor-phase (or dry-type) doping in which it is exposed to a vapor atmosphere of iodine or ferric chloride, (2)
Wet doping in which the polymer is immersed in a solution in which iodine or ferric chloride is dissolved in an inert solvent, (3) When the polymer is dissolved in a solution in which iodine or ferric chloride is dissolved, Co-doping is used in which a film or coating film is formed by dry film formation and simultaneously doped.

The inert solvent used in the wet doping of (2) and (3) is a solvent which does not deactivate the ability as an electron-accepting compound by reacting with iodine or ferric chloride.
As such, hydrocarbons such as hexane, octane and cyclohexane, aromatics such as toluene, xylene and nitrobenzene, ethers, ethers such as tetrahydrofuran, dimethylformamide, dimethylsulfoxide and hexamethylphosphoric triamide. Aprotic polar solvent, other, nitromethane,
Acetonitrile etc. are mentioned.

Among them, a solvent such as tetrahydrofuran dissolves the above-mentioned silicon-containing polymer compound very well, and is therefore preferably used for co-doping. In this method, a polymer is dissolved in a solution containing a dopant, the solution is cast, and then dried,
It is possible to obtain a doped conductor. The drying temperature is usually 0 to 150 ° C. and normal pressure or reduced pressure is preferable.

However, in the wet method, the polymer is often deteriorated by the dopant and may be gelated or decomposed. In such a case, the gas phase doping of (1) does not use a solvent,
It is particularly useful because the operation is simple and high conductivity can be obtained.

In this vapor phase doping, the doping rate can be controlled by controlling the temperature of the dopant atmosphere and the dopant partial pressure. Generally, the temperature is preferably in the range of -30 to 200 ° C. If the temperature is lower than that, the doping rate is slow, and if it is higher than that, the polymer is deteriorated during doping, which is not preferable. The dopant partial pressure is 0.001 mmHg to 3800.
It is preferable to perform in the range of mmHg. At lower pressures, the doping rate is slower, and at higher pressures, increasing the pressure does not increase the doping rate. It should be noted that with iodine, doping proceeds rapidly at room temperature and atmospheric pressure,
In the case of ferric chloride, the vapor pressure is low, so the doping conditions differ from those of iodine. Ferric chloride doping is generally preferably performed at a temperature in the range of 50 to 300 ° C.
If the temperature is lower than that, the doping rate is slow, and if it is higher than that, the polymer is deteriorated during doping, which is not preferable. Further, the doping is 0.001 mmHg-76.
It is preferably performed in the range of 0 mmHg. At lower pressure, it takes a long time to reach that pressure, which is not economical, and at higher pressure, ferric chloride is 319 at normal pressure.
Since it has a boiling point of ℃, the doping rate is very slow. The dopant partial pressure of ferric chloride is more preferably 0.1 to 10 in order to effectively increase the conductivity of the polymer.
The doping is preferably performed at a pressure of mmHg and at a temperature in the range of 50 to 200 ° C. By this method,
It is possible to produce a conductive polymer using ferric chloride, which is less toxic, without using a flammable solvent, by a very simple operation.

[0029]

According to the present invention, a silicon-containing polymer compound containing an amine compound is doped with an oxidizing dopant (iodine, ferric chloride, etc.) to obtain a highly conductive composition having excellent shapeability. Therefore, it is possible to easily obtain a highly conductive film or coating film having excellent shapeability, and to obtain a useful material applicable to battery electrodes, solar cells, housings for electromagnetic shields, etc. It is a thing.

[0030]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

In the following examples, the method of measuring the conductivity is to form four terminals on a glass plate by platinum vapor deposition to form electrodes, and spin-coat a polymer solution dissolved in a solvent on the electrodes. A thin film was prepared and used as a sample for conductivity measurement. This was shielded from light and brought into contact with iodine or ferric chloride under airtight condition, and the change in direct current resistance with time was traced.
Conductivity was determined from the resistance value which was a stable value at (° C.).

[Synthesis Example 1] Method for producing polysilane and poly (disilanylenephenylene) Sodium metal was added to toluene under a nitrogen stream and heated to 120 ° C with high speed stirring for dispersion. Dichlorodiorganosilane or bis (chlorodialkylsilyl) benzene was slowly added dropwise thereto with stirring.
The amount of addition is 2 mol of sodium metal based on 1 mol of silicon compound.
~ 3 moles. The reaction was completed by stirring for 4 hours until the raw materials disappeared. Then, after allowing to cool, the salt was filtered and concentrated to easily obtain polysilane, poly (disilanylenephenylene), or the like.

Example 1 10 parts by weight of various silicon-containing polymer compounds shown in Table 1 were dissolved in 100 parts by weight of toluene, and 3 parts by weight of triphenylamine was mixed therein. On the other hand, 4 terminals were formed on the glass plate by platinum vapor deposition to form electrodes, on which the polymer solution prepared above was spin coated and dried at 2 mmHg / 50 ° C. to form a thin film with a thickness of about 1 μm. The sample for conductivity measurement (1) was prepared. Immediately after the film formation, this film was mounted in a dried brown glass bottle container, and allowed to stand still with solid iodine at the bottom of the container sealed. The conductivity was calculated from the value when the steady state was set.
For comparison, the conductivity without addition of amine was determined. The results are shown in Table 1.

[0034]

[Table 1]

Example 2 Using the above phenylmethylpolysilane as the silicon-containing polymer compound, the amount of triphenylamine and the conductivity when the time from film formation to doping was changed were examined in the same manner as in Example 1. . The results are shown in Table 2.

[0036]

[Table 2]

[Example 3] Phenylmethylpolysilane 30 parts by weight of various amines shown in Table 3 were mixed with 100 parts by weight of a polymer to prepare a toluene solution, and a film was prepared by spin coating. Immediately after film formation, iodine doping was performed. Then, the conductive behavior was examined in the same manner as in Example 1.
The results are shown in Table 3.

[0038]

[Table 3]

[Example 4] With respect to phenylmethylpolysilane, 30 parts by weight of triphenylamine was mixed with 100 parts by weight of a polymer to prepare a toluene solution, a film was prepared by spin coating, and the film was dried in a brown glass bottle. It was placed in a container and allowed to stand under solid sealing with solid ferric chloride at the bottom of the container. This was connected to a vacuum pump and the pressure was reduced to 4 mmHg. In this state, the ferric chloride portion at the bottom was heated with a mantle heater. By this operation, the sample for conductivity measurement changed from transparent to blackish brown, and at the same time, the conductivity rapidly increased. Finally, the conductivity settled down to a constant value, at which time the temperature of the sample for measuring conductivity reached 150 ° C. Here, the vacuum pump was stopped, heating was stopped, and the mixture was allowed to cool to 25 ° C. The conductivity was calculated from the value when the steady state was set. The results are shown in Table 4.
Shown in.

[0040]

[Table 4]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Mori 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Shin-Etsu Chemical Co., Ltd. Corporate Research Center

Claims (4)

[Claims] 1. A conductive polymer composition comprising a silicon-containing polymer compound containing an amine compound doped with an oxidizing dopant. 2. A silicon-containing polymer compound having a main chain of Si-
A compound having a Si bond or a Si-Si bond and a C-C multiple bond, and the amine compound is a tertiary amine.
The composition as described. 3. The composition according to claim 2, wherein the tertiary amine contains an aromatic ring. 4. The composition according to claim 2 or 3, wherein the silicon-containing polymer compound is selected from polysilanes, poly (disilanylenephenylene) s, and poly (disilanyleneethynylene) s.