JPH0365370B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel organic conductive material. BACKGROUND ART In recent years, with the remarkable technological development in the electrical and electronic industries, there is a demand for new materials with excellent electrical functions. Materials with various electrical properties have also been discovered in the field of polymer chemistry, and many polymer substances are already in practical use, but the search for materials with even better electrical properties is actively underway. In particular, polymeric materials having electrical conductivity can be used as materials for, for example, wiring materials, electrode materials, sensors, photoelectric conversion elements, and the development of such polymeric materials is highly anticipated. Against the background of such social demands, research into polymeric materials with electrical conductivity is being conducted in various places, and many polymeric materials with electrical conductivity have also been developed. However, currently known polymeric materials with high conductivity have problems with stability, moldability, etc., and their application to electrical and electronic materials is currently limited. For example, a complex of unsubstituted polyacetylene and a specific electron donor or electron acceptor is a polymeric material with extremely high electrical conductivity of 10 ³ Ω ^-1 cm ^-1 or more, and is useful as an electronics material. The disadvantage is that the polyacetylene of the matrix is unstable to oxygen in the air and heat. Furthermore, since high molecular weight polyacetylene is insoluble and infusible, melt processing or solution processing is impossible, and it is difficult to mold it into a certain shape. There are many similar problems with other conductive polymer materials, which hinder the use of these polymer materials as electrical and electronic materials. Among these, poly(phenylene), in contrast to polyacetylene, is a polymeric material with very high thermal and oxidative stability. This highest degree of stability is based on poly(phenylene), which consists of conjugated phenylene bonds, and poly(paraphenylene) is stable at temperatures of 400°C in air and 550°C under an inert atmosphere. Furthermore, by doping polyphenylene with an electron donating agent or an electron accepting agent, high electrical conductivity similar to that of the polyacetylene can be obtained. For this reason, it is attracting attention as a new electrical and electronic material, and its application to secondary battery electrode materials and the like is attracting attention. However, the unsubstituted poly(phenylene) that has been studied to date is insoluble and infusible, making it difficult to mold and process. The current situation was that it was not done. The inventors have discovered that such poly(phenylene)
Focusing on its stability and high electrical conductivity, we conducted intensive research to develop a poly(phenylene)-based polymer material with excellent processability and electrical conductivity. As a result, it was discovered that by doping poly(alkoxyphenylene) with an electron donor or an electron acceptor, a polymer material composition satisfying stability, moldability, and electrical conductivity could be obtained, and the present invention I was able to complete it. The present invention provides that the substantial repeating unit is

[Formula] (In the formula, R and R' represent an alkyl group having 1 to 8 carbon atoms that are the same or different from each other.) Poly(dialkoxyphenylene) represented by the formula: an electron-donating doping agent and an electron-accepting doping agent The present invention relates to a poly(dialkoxyphenylene) composition containing one or more of the following. The alkyl group herein refers to a general alkyl group having 1 to 8 carbon atoms, and may be linear, branched, or cyclic. Of course, the poly(dialkoxyphenylene) in the present invention does not mean only a complete homopolymer in the strict sense, as is customary in the field of polymer technology, but it is substantially a poly(dialkoxyphenylene). Any substance that falls within the category of alkoxyphenylene (alkoxyphenylene) and can achieve the purpose of the present invention may be used. Methods for producing polydialkoxyphenylene used in the present invention include a method in which dialkoxybenzene is polymerized in the presence of a Lewis acid and an oxidizing agent, and a method in which dihalodialkoxybenzene is polymerized in the presence of magnesium, copper, and zinc alkyl lithium. All known methods for producing polyphenylene are possible, such as, but the general formula (In the formula, R and R' represent alkyl groups having 1 to 8 carbon atoms, which are the same or different from each other.) When dialkoxybenzene represented by the following is polymerized in an inert solvent in the presence of a Lewis acid and an oxidizing agent: Excellent results can be obtained. As the Lewis acid, any one used in cationic polymerization or coordination polymerization can be suitably used. Such Lewis acids include anhydrous aluminum chloride, anhydrous ferric chloride, anhydrous titanium chloride (), anhydrous stannic chloride, anhydrous molybdenum chloride, anhydrous tungsten chloride, anhydrous antimony chloride (),
Although boron fluoride and boron fluoride etherate are used, anhydrous aluminum chloride and anhydrous ferric chloride are particularly preferred. It is also effective to use other halides such as metal bromides corresponding to the metal chlorides. The amount of Lewis acid varies depending on solubility and activity, but is usually 1 to 5 moles per mole of dialkoxybenzene. In the production reaction of the polymer compound of the present invention, in addition to a Lewis acid, a high valence transition metal compound such as cupric chloride, ferric chloride, tin chloride, etc. is added to the Lewis acid as necessary to proceed efficiently. An oxidizing agent such as a halide, an oxide such as manganese dioxide, or lead dioxide may be present as necessary. Further, if necessary, oxygen may be introduced and a cocatalyst such as a cobalt () complex compound such as cobalt acetate may be used. The inert solvent is one used in ordinary Friedel-Crafts reactions, and any organic solvent inert to the Lewis acid aryl cation can be used, but nitroalkanes are particularly preferred. The amount of solvent is 1 to 20 parts by weight of dialkoxybenzene.
Parts by weight are common. The polymerization reaction can be carried out at normal pressure, increased pressure, or reduced pressure, but the pressure must be such that the hydrogen chloride generated can be removed.
By creating a reduced pressure state of 10 to 40 mmHg,
A polymer with excellent heat resistance, moldability, etc. can be obtained. The reaction temperature can be between -30 and 100°C, but it is operationally advantageous to carry out the reaction at 0 to 40°C, around room temperature. The reaction time varies depending on the type of dialkoxyphenylene, the type of oxidizing agent, etc., but the reaction is considered to be completed when the generation of hydrogen chloride gas is completed, and the time required for this is 30 minutes to 2 hours. It may be carried out for a longer period of time if necessary. Dopants applicable to the compositions of the present invention include electron donors that increase the intrinsic conductivity of the poly(dialkoxyphenylene) or increase the conductivity of the poly(dialkoxyphenylene) to about 10 ^-7 Ω ^-1 Included are electron acceptors or mixtures of such electron donors and acceptors that increase electrons above cm ^-1 . Preferably, the DC conductivity of the composition is about 10 ^-5 Ω ^-1 cm ^-1 or greater, as measured by the four-probe method at room temperature. Typical examples of applicable dopants include lithium,
Group IA metals including sodium, potassium, havidium and cesium; Group IA metal arylenes such as sodium naphthalene, potassium naphthalene, sodium biphenyl and potassium biphenyl;
Brønsted acid containing electron donors such as Group A metals such as magnesium, calcium and _HCIO4 ;
non-metallic oxides, including SO ₃ and N ₂ O ₅ , sulfides of group elements, including Sb ₂ S ₅ , group B, transition metals,
B, A and group A halides, and
Inert gases including _SbCl5 , _BCl3 , _{CrO2Cl2 ,
CrO2F2 , SbF3Cl2AsF5 , XeF4} , _XeOF4 , _{SbF5 ,
PF5} , _BF5 , _BCl5SbBr3 , _CuCI2 , _{NiCl2 and}
Electron acceptors such as halides such as MoCl ₅ , WCl ₆ , VOCl ₃ , SnCl ₄ and fluorine-containing peroxides including FSO ₂ OOSO ₂ F or mixtures thereof, silver and alkali metals, alkaline earth metals and Examples include quaternary ammonium tetrafluoroborates, phosphonium hexafluoride salts, perchlorates, hexafluoroantimonates, hexafluoroarsenates, and the like. The type of dopant selected depends on what electrical properties are desired in the resulting composition. Electron-donating dopants such as Group A metals and Group A metal arylenes provide n-type conductive materials, and electron-accepting dopants such as _AsF5 provide p-type materials, which can be selected depending on the application and purpose. can. The conductor dope concentration in the composition is approximately per mole of repeating unit in the polymer.
10 ⁻⁵ to 0.5 mol. Maximum electrical conductivity is generally more easily achieved using electron-donating or electron-accepting dopants alone than as a mixture. Generally, electrical conductivity increases with increasing dopant concentration, and the dopant concentration that provides a maximum value is usually about 0.5 mole or less per mole of repeating unit in the poly(dialkoxyphenylene).
When undoped poly(alkoxyphenylene) is fully doped, the main increase in electrical conductivity occurs below about one-fifth of this maximum dopant concentration. There are various methods for adding conductive dopants to poly(dialkoxyphenylene) to form charge transfer complexes. For example, addition of the dopant from the gas phase, addition from the solution phase, addition in the molten phase or addition by intimate mixing of solid materials. Similarly, it is also possible to form charge transfer complexes of poly(dialkoxyphenylene) using electrochemical reactions. If high electrical conductivity is desired, it is important to avoid doping conditions such as high temperatures, halogenation, sulfonation, or nitration that would cleave the covalent bonds of the poly(phenylene) molecule. The temperature is preferably 100° C. or lower, and the reaction is typically carried out at room temperature or lower. Generally, when the dopant is a gas or a solid with a significant vapor pressure at room temperature, solid poly(dialkoxyphenylene)
Preferably, the dopant is contacted with the dopant in gas or vapor form. In this case, it is more preferable to carry out the reaction under reduced pressure. When the dopant is solid at room temperature, it is preferred to contact the poly(dialkoxyphenylene) with a solution of the dopant in an inert solvent. Typical solvents include acetonitrile, diethyl ether, and the like. The rate of dopant addition to poly(dialkoxyphenylene) in the gas phase is usually determined primarily by reaction temperature and dopant concentration (or vapor pressure), but is not critical. However, if a complex with optimal electrical conductivity is required, it is desirable to add the dopant at a rate comparable to the desired production rate, e.g. it is necessary to dope in the gas phase to obtain a complex with high electrical conductivity. In such cases, it is effective to increase the gas pressure. Dopants should be added to poly(phenylene) before, during, or after shaping the polymer into a specific shape.
Either of the latter is fine. The poly(dialkoxyphenylene) used in the present invention has significantly improved moldability compared to conventionally known polyphenylenes. In particular, by selecting an alkoxy group, it becomes soluble in general-purpose organic solvents such as toluene, dimethylformamide, tetrahydrofuran, etc., making it possible to form a film by a cast method. Furthermore, poly(dialkoxyphenylene) has a melting point and can be melt-molded under appropriate conditions. In this way, films and fibers can be formed into desired shapes using ordinary polymer processing techniques.
In general, the dopant can be added either before or after dissolving the polymer, during solution or melt processing, or after the product shape has been imparted by solution or melt processing. Further, similarly to insoluble and infusible poly(phenylene), the polymer can be processed into a desired shape using pressure compacting and pressure sintering techniques. To reiterate, dopants can generally be added before, during, or after the processing step. However, for dopants with poor high temperature stability, doping treatment after molding is preferred. This method can also provide materials that are electrically conductive on the surface and insulating on the inside. In this case, the contact time of the dopant is insufficient to prevent the dopant from diffusing into a large portion of the article. The composition according to the present invention also means a specific tangible article or molded article made of a material having the above composition.
Therefore, examples of such compositions include n-type and p-type materials, rectifier diodes and transistors, conductors such as n-p bonds, semiconductor devices, solar cells, etc. to which the composition of the present invention is applied. Is possible. In obtaining such various compositions, the advantage of the composition of the present invention as a raw material compared to other conductive polymer materials such as polyacetylene, (SN)x, etc. is that the matrix poly(dialkoxyphenylene) Due to this, it has excellent moldability. Further, the highly electrically conductive poly(dialkoxyphenylene) complex has high absorption ability over a wide spectral range in the infrared region. Such materials can therefore be used as filter materials, for example safety glasses and infrared absorbers for solar energy. Also, because the compositions of the invention are electrically conductive, they can be used as antistatic materials or devices, such as internal gaskets in solvent container lids. EXAMPLES The present invention will be specifically explained in more detail with reference to Examples below. Example 1 Nitromethane 50 in which 40 g of anhydrous ferric chloride was dissolved
ml of paradiethoxybenzene dissolved in 120 ml of nitromethane at room temperature under a vacuum of 20 mmHg.
Add 16.6 g carefully so that the internal temperature does not exceed 40°C, and then stir at room temperature under a reduced pressure of 20 mmHg for 2 hours. The reaction product was added to 300 ml of methanol at room temperature, stirred for 1 hour, and insoluble matter was filtered off. insoluble matter
After repeated thorough washing with 2N hydrochloric acid, the product was dried overnight under vacuum at 100°C to obtain a blackish brown polymer in a yield of 11.3g (69%). This polymer was heated and melted to form a film with a thickness of 0.1 mm. About this film
SbF ₅ , SO ₃ , FeCl ₃ , HClO ₄ , AlCl ₃ ,
Doping was carried out using AgClO ₄ LiPF ₆ and tetrafluoroborate of tetrabutylammonium. At this time, SbF ₅ was left in an atmosphere at room temperature for 64 hours, and FeCl ₃ , HCIO ₄ , AlCl ₃ ,
For _AgClO4 , this was achieved by immersion in a 10 mol% acetonitrile solution at room temperature for 64 hours. In addition, for LiPF ₆ and [NBu ₄ ] [BF ₄ ], platinum electrodes were attached to the prepared polymer moldings, and
Using this as an anode and a cathode, it was electrochemically doped by immersing it in a 1 μ propylene carbonate solution of LiPF ₆ or [NBu ₄ ] [BF ₄ ] and applying current at a DC voltage of 10 V for 120 hours. The electrical conductivity of the film thus obtained and an untreated film for comparison were measured, and the results are shown in the table. Example 2 13.4 g of well-crushed anhydrous aluminum chloride and 13.5 g of anhydrous cupric chloride were added to 50 ml of nitromethane,
Add 13.8 g of dimethoxybenzene dissolved in 50 ml of nitromethane under reduced pressure. By the same operation as in Example 1, 4.6 g (33%) of a dark brown polymer was obtained. Doping was performed using this polymer in powder form in the same manner as in Example 1. Example 3 The same procedure as in Example 1 was carried out except that 19.8 g of dibutoxybenzene was used instead of paradiethoxybenzene to obtain 12.7 g (65%) of a light brown polymer. A film with a thickness of 10 μm was prepared from a toluene solution of this polymer by a casting method. This film was doped in the same manner as in Example 1. Example 4 The same reaction as in Example 1 was carried out except that 19.4 g of dibropoxybenzene was used instead of diethoxybenzene to produce light brown poly(diproboxybenzene).
15.7g was obtained. This polymer was formed into a film with a thickness of 10 μm by casting from a dimethylformamide solution. This film was doped in the same manner as in Example 1. The electrical conductivity measurement results for films prepared by doping using the methods of Examples 2 to 4 and untreated films are shown in the table. Example 5 The poly(diethoxyphenylene) obtained in Example 1 was molded into pellets using an infrared absorption spectroscopy tablet molding machine, and the pellets were made into sodium naphthalene synthesized with naphthalene and metallic sodium in ether. Doping was performed by immersing the sample in an ether solution containing the following for 2 hours. After thoroughly washing the doped pellet with ether, the electrical conductivity of the pellet was measured using the four-probe method, and the result showed an electrical conductivity of 2.0×10 ^-7 Ω ^-1 cm ^-1 . Each of the polymers obtained in Examples 2 to 4 was doped in the same manner and the conductivity was measured. As a result, the electrical conductivity was as shown in the table.

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Claims (1)

[Scope of Claims] 1 Substantive repeating units are poly(dialkoxy phenylene) and electron-donating dopants and electron-accepting dopants.
A poly(dialkoxyphenylene) composition containing one or more species. 2. The composition according to claim 1, which has a DC electrical conductivity of 10 ^-7 Ω ^-1 cm ^-1 or more as measured by the four-probe method at room temperature. 3 The dopant is poly(alkoxyphenylene)
The composition according to claim 1 or 2, wherein the composition is present in an amount of 10 ^-5 to 0.5 mol per mol of repeating unit. 4. The composition according to claim 1, 2 or 3, wherein the electron-accepting dopant is a group metal halide. 5. The composition according to claim 1, 2 or 3, wherein the electron-accepting dopant is a halide of a group element. 6. The composition according to claim 1, 2 or 3, wherein the electron-accepting dopant is Brønsted acid or its anhydride. 7. The composition according to claim 1, 2 or 3, wherein the electron-accepting dopant is a transition metal halide in a high valence state. 8. The composition according to claim 1, 2 or 3, wherein the electron-accepting dopant is an alkali metal or an alkaline earth metal. 9 Obtained by doping with silver, alkali metal, alkaline earth metal or quaternary ammonium tetrafluoroborate, hexafluorophosphonium salt, perchlorate, hexafluoroantimonate or hexafluoroarsenate A composition according to claim 1, 2 or 3.