JPH0351741B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel conductive polymer compositions. More specifically, the present invention relates to a doped heteroacene polymer composition comprising a pyrazine ring-containing heteroacene polymer and an electron-accepting compound.

In recent years, when polyacetylene is doped with an electron-accepting substance (electron-accepting dopant) or an electron-donating substance (electron-donating dopant), a charge transfer complex formation reaction occurs, resulting in high electrical conductivity (electronic conductivity).
Since it was discovered that organic polymers exhibit such conductivity, organic polymers that can exhibit such conductivity have attracted attention.

The reason why these polymers have come to exhibit high electrical conductivity through doping is that these polymers and electron-accepting dopants or electron-donating dopants form complexes, and the charges (carriers) generated thereby are conjugated binary. It is explained that this is due to movement through a conjugated system of heavy bonds.

The present inventors focused on the electron-donating property and conjugation property of a ladder-type polymer with a conjugated double bond system, and as a result of intensive studies, it was found that a ladder-type polymer consisting of repeating units shown in [ ] above has a specific property. The present invention was achieved by discovering that it can be doped with an electron-accepting dopant and exhibiting high electrical conductivity.

That is, the present invention provides: 1 The following formula [] This is a doped ladder polymer composition formed from a ladder polymer mainly composed of repeating units represented by the formula and an electron-accepting compound.

The ladder type polymer consisting of repeating units represented by the above formula [] used in the present invention is JK
Stille, ELMainen, Macromolecules, 1 , 36
(1968), it can be synthesized as shown below.

In the present invention, doping refers to the addition of an electron-accepting compound as described below to the ladder polymer so that the ladder polymer itself has improved electrical conductivity than its own inherent electrical conductivity. Not only when they form chemical bonds with each other, for example, complexes,
It also includes things that simply exist in a mixed state.

Electron-accepting compounds used in the present invention include halogens such as iodine, bromine, and bromine iodide; antimony pentafluoride, arsenic pentafluoride, titanium tetrachloride, tin tetrachloride, iron trichloride, and trioxide. Examples include Lewis acids such as sulfur.

In the present invention, the desired electrical conductivity is expressed by the interaction between the ladder polymer and the electron-accepting compound, and the height of the electrical conductivity varies greatly depending on the type and amount of the electron-accepting compound. . The amount of the electron-accepting compound is 5 to 50 parts by weight, preferably 10 to 400 parts by weight, based on 100 parts by weight of the ladder polymer. Otherwise, the desired electrical conductivity will not be achieved, and conversely, even if more than that is added, not only will the electrical conductivity not be expected to improve as much as the addition, but
In some cases, this is undesirable because it reduces
However, the magnitude of electrical conductivity should be controlled depending on the application, and it goes without saying that it is not necessarily evaluated based on height alone.

The treatment method for causing the ladder-type polymer to interact with the electron-accepting compound, ie, the doping method, is carried out as follows.

(1) In the case of electron-accepting compounds that are gases themselves or have vapor pressure, such as halogens, antimony pentafluoride, or sulfur trioxide, the so-called gas phase doping method involves exposing them to the vapor atmosphere ( 2) A wet doping method is used in which the ladder-type polymer is immersed in a solution in which an electron-accepting compound is dissolved in an inert solvent.

In the vapor phase doping method, the doping amount can be controlled by the temperature of the dopant atmosphere, the dopant partial pressure, and the doping time. The temperature varies depending on the type of dopant, but generally -
The temperature is 30 to 250°C, preferably 0 to 200°C. If it is less than that, the doping rate will be slow, and if it is more than that, it will be difficult to control or cause deterioration of the polymer, which is not preferable. In addition, the partial pressure of the dopant is 1 mmHg to 10 atm, preferably
It is carried out in the range of 10 mmHg to 5 atmospheres. Below that, doping is generally slow, and above that, increasing the pressure has no effect, which is not preferable. The doping time is generally 1 minute to 1000 hours, preferably 5 minutes to 500 hours, although it depends on the type of dopant, temperature, and dopant partial pressure.

The inert solvent used in wet doping is a solvent that reacts with the electron-accepting compound to deactivate its ability as an electron-accepting compound, or reacts with the ladder polymer to impair its original function. It means a solvent that does not degrade. Examples of such inert solvents include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone;
Hydrocarbons such as hexane, heptane, petroleum ether, and cyclohexane, aromatic solvents such as benzene, toluene, xylene, nitrobenzene, and anisole, ethers such as ether, tetrahydrofuran, and dioxane, ethyl acetate, butyl acetate, cellosolve acetate, and isoamyl acetate. alcohols such as methanol, ethanol, isopropanol, butanol, aprotic polar solvents such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone, and other solvents such as nitromethane and acetonitrile.

Of course, these solvents are appropriately selected depending on the solubility and type of the dopant. In addition, the immersion temperature and time are not particularly limited, but generally 0.1g/~saturated concentration, preferably 1g/~saturated concentration, -30~
The temperature is 100°C, preferably 0 to 80°C, and the time is 1 minute to 100 hours, preferably 5 minutes to 80 hours.

The ladder-shaped polymerization volume can be formed into a disk-like, sheet-like, or powder-like material and then subjected to a doping treatment with the electron-accepting compound to impart high electrical conductivity.

The doped ladder-shaped polymers obtained in the present invention not only exhibit high electrical conductivity but also can be easily formed into various molded products, such as batteries. It is a useful material for electrodes, solar cell materials, electromagnetic shielding casings, etc., and is widely used in the electrical, electronic, and communication fields.

Hereinafter, the present invention will be explained in detail with reference to Examples. however,
The present invention is not limited to this. In the examples, all "parts" refer to "parts by weight." Note that the doping amount (%) is expressed as the weight part of the doped dopant relative to the weight part of the polymer before doping.

Synthesis Example 1 Poly(1,6-dihydropyrazine[2,3-
g] Quinoxaline-2,3,8-tolyl-7-
A method for synthesizing (2H)-ylidene-7,8-dimethylidene (a ladder-shaped polymer consisting of repeating units represented by the above formula) is shown below.

In 264 parts of 116% polyphosphoric acid, 1,2,4,5-
Add 2.31 parts of tetraaminobenzene tetrahydrochloride,
Hydrogen chloride was removed at 80°C for 2 hours and at 140°C for 2 hours under a nitrogen stream. Then 1.12 parts of 2,5-dihydroxy-p-benzoquinone was added. at 180℃
After stirring for 12 hours and cooling, the reaction mixture was poured into ice water and the black-purple precipitate was filtered off. After washing and drying, 1.4 parts of the ladder polymer was obtained. The logarithmic viscosity of the obtained polymer was 0.12 dl/g (0.5 g/dl sulfuric acid,
30℃).

Example 1 The ladder-shaped polymer obtained in Synthesis Example 1 was pressed at a pressure of 2t/cm ² using an infrared tablet press to reduce the diameter.
A disk-shaped sample with a size of 12.5 mm and a thickness of approximately 500 μm was prepared. The conductivity of this sample in its undoped state is
It was 5.8×10 ^-6 S/cm. This sample was used for gas phase doping with bromine. Two terminals were attached to the sample using carbon-based conductive paint and gold wire, and bromine doping was performed at 40°C. Picoammeter 4140B manufactured by Yokogawa Heuretsu Patscard Co., Ltd.
The changes in conductivity were investigated online using . The conductivity was saturated after 14 minutes. The conductivity at this time is 2.1×
It was 10 ^-3 S/cm.

Example 2 The ladder-shaped polymer obtained in Synthesis Example 1 was subjected to vapor phase doping at 40° C. in an iodine atmosphere while in powder form. The amount of iodine absorbed at this time was 53 wt%. Using the same infrared tablet press as in Example 1, the iodine-doped ladder polymer was processed into 2 tons/kg.
cm ² was pressed under pressure to obtain a disk-shaped sample. Four terminals were attached to this and the electrical conductivity was measured. The electrical conductivity of this material was 1.0×10 ⁻⁵ S/cm.

Example 3 An undoped disc-shaped sample was molded in the same manner as in Example 1. Two terminals were attached to this sample using carbon-based conductive paint and gold wire, and the temperature was raised to 40°C.
vapor phase doping with antimony pentafluoride. Picoammeter manufactured by Yokogawa Heuretsu Pats Card Co., Ltd.
Changes in conductivity were investigated online using 4140B. The conductivity reached saturation after about 10 minutes. The conductivity at this time was 2.4×10 ⁻⁵ S/cm.

Claims (1)

[Claims] 1. The following formula [] A doped ladder polymer composition formed from a ladder polymer mainly consisting of repeating units represented by: and an electron-accepting compound.