JPS5887147A - Conductive acetylene high polymer - Google Patents

Abstract

PURPOSE:To provide an n type semiconducting acetylene high polymer with a high electrical conductivity, by doping thereto a specific cation electrochemically. CONSTITUTION:One or more cations of (i) nitrosouium ion (NO<+>), (ii) nitronium ion (NO<+>) and, (iii) hydrazonium ion (N2H<+>5) are used. A salt of the above cations (e.g., NO<+>.BF<->4), as a supporting electrolyte, is dissolved in an aprotic org. solvent with a high dielectric constant (e.g., propylene carbonate) to form an electrolytic soln. Then, in the electrolytic soln., the cation is doped to an acetylene high polymer (pref. having a fibrous microcrystalline structure) as the cathode by applying the voltage above about 0.4V DC. The amt. of doping is pref. about 1-40mol% per mol of a CH repeating unit in the acetylene high polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to acetylene polymers with high electrical conductivity.

Powdered acetylene polymers obtained by polymerizing acetylene using a so-called Ziegler-Natsuta catalyst consisting of a transition metal compound and an organometallic compound have electrical conductivity in the semiconductor region, making them useful materials for electrical and electronic devices. It is already known that it is useful as Further, this powdered acetylene high polymer was added to BF8. BCj? 3. HC/
, Cf2. SO2゜No2. HCN, 02. When treated with an electron-accepting compound (acceptor) such as No, the electrical conductivity increases by up to 3 orders of magnitude, and conversely, when treated with an electron-donating compound (donor) such as ammonia or methylamine, the electrical conductivity decreases by up to 4 orders of magnitude. It is also already known to do (
D., J., Beretset al., TransOFa.
rady Soc.

Dan, 823 (1968)).

Furthermore, it is already known that under certain polymerization conditions, thin films of acetylene polymers having a fibrous microcrystalline (fibril) structure can be obtained (Japanese Patent Publication No. 48-32581
issue). In recent years, I2. C72°Br2. IC1! , IBr
, AsF515bli'', , PF6., etc., or by chemically doping Na with an electron-donating compound such as Li, the electrical conductivity of the acetylene polymer can be increased to a wide range of 10 to 10 Ω m. It is also already known that it can be freely controlled over a range (J, C1S).

Chem, Commu,, 578 (] 977),
Phys, Rev. Le-tt., 39.1098 (1
977), J, Am, Chem, Sac.

±00.1013 (1978), J, Chem, Phy
a, 695098 (1978)].

Some of the present inventors have proposed a method for producing an acetylene polymer having a fibrous microcrystalline (fibril) structure by a method different from the above-mentioned method, and a method for molding the same (Japanese Unexamined Patent Publication No. 55-12
No. 8419, No. 55-129404, No. 55-142
No. 030, No. 55-145710, No. 55-1457
No. 11, No. 56-10428, patent application No. 55-346
No. 87) and a method for producing an acetylene polymer with high electrical conductivity by treating an acetylene polymer with a new dopant (JP-A-55-129424, No. 55)
-129425, 55-129426, 55-
No. 129427, No. 55-143702, No. 55-1
43703) has already been proposed.

In addition to the above-mentioned chemical doping method, electrochemical doping of CIO: , PF6-+ As F6, A
Anions such as sF4'', CF3503-, BF; and cations such as R-type (R1': alkyl group) are doped into acetylene polymers to form p-type and n-type polymers.
Methods have also been developed to produce conductive acetylene polymers of the type [J, C, S, Chem, Cornm.
u,] 979, 594, C&ENJan. 2
6.39 (1981), J.C.S.Chem.
Commu,.

1981.317].

However, when electrochemically doping N4H to produce an n-type conductive acetylene polymer, the amount of dopant that can be doped into the acetylene polymer is at most 6 moles per repeating unit CH of the acetylene polymer. He was in charge of the mall. When the amount of the dopant exceeds 6 molar ratios, a portion of the acetylene polymer deteriorates, resulting in a sharp drop in electrical conductivity. Increasing the amount of dopant that can be toped into the acetylene polymer is a significant improvement in the number of batches using the acetylene polymer as an electrode.
.

26.39 (1981), J.C.S.Chem.Co.
It is an essential requirement for increasing the energy density of mmu, ]98U, 317] and for producing acetylene high polymers with higher electrical conductivity, and among those in the industry, it is essential to increase the energy density of acetylene high polymers without degrading them. There has been a strong desire to develop a new dopant that can be doped in a larger amount and provides an n-type conductive acetylene polymer.

In view of the above points, the present inventors have discovered the present invention as a result of various studies on dopants that can be doped in larger amounts without deteriorating the acetylene polymer.

That is, the present invention provides an acetylene polymer with (i) nitrosonium ion (No) (11) nitronium ion (NO2) (hydrazonium ion (N2H)
This invention relates to an electrically conductive acetylene polymer comprising at least one cation selected from , ).

The conductive acetylene polymer of the present invention can be doped in a large amount without deteriorating the acetylene polymer by using cations as a dopant. It is most suitable as an n-type acetylene polymer with high electrical conductivity.

The acetylene polymer used in the present invention is not particularly limited, and can be used in any form such as powder, film, or fiber, but fibrous microcrystals (
An acetylene polymer having a fibril structure is preferred. Specific production examples of acetylene polymers include, for example, Japanese Patent Publication No. 48-32581, J. Chem, Phy.
s,, 69(],), 106-l1l (1978)
method, and JP-A-55-1.28419 and JP-A-55-129404, which some of the present inventors have already proposed.
No. 55-142030, No. 55-145710, No. 55-145711, No. 56-1042'8,
Examples include methods such as those disclosed in Japanese Patent Application No. 55-34687, but the method is not necessarily limited to acetylene polymers obtained by these methods.

The cation used in the present invention can be prepared using a known electrochemical method (J, COS) by using a salt with an anion such as HF2 as a supporting electrolyte.

Chem, Commu, 1979, 594,
J, C, S, Chem.

(Commu, J981, 317), but it is not necessarily limited to these compounds, and the gist of the present invention is to dope with (:) nitrosonium ion (No) (11) nitronium ion (NO2 ) (song) The method consists in doping an acetylene polymer with at least one cation selected from hydrazonium ions (N2H, ).

The amount of cation doped into the acetylene polymer is 1 to 40 mol, preferably 2 to 30 mol, per mol of repeating unit CH of the acetylene polymer. If the cation doping amount is less than 1 mol, it is not possible to produce an acetylene polymer with sufficiently high electrical conductivity, and if the doping amount exceeds 40 mol, the acetylene polymer will undergo oxidative deterioration. Undesirable.

The method of electrochemically doping the acetylene polymer with the cation of the present invention is a method already known [J, COS, C
hem, Commu, -1979,594,1 bid
,.

] 981.31.7, JJelectroanal,
Chem,, upper uni.

11 s (1,9s o )], but usually, the cation salt of the present invention is dissolved in an aprotic and high dielectric constant organic solvent to prepare an electrolytic solution, and the acetylene high polymer This can be done by applying a DC voltage of 0.8 mm or more so that the electrode becomes the cathode electrode. The amount of cation doped can be freely controlled by measuring the amount of electricity flowing during electrolysis. Doping may be carried out either under constant current, constant voltage, or varying current and voltage conditions. The current value, voltage value, doping time, etc. during doping depend on the bulk density and area of the acetylene polymer used, the type of dopant (cation), the type of electrolyte, and the required electrical conductivity of the acetylene polymer. Since it varies depending on the conductivity, it cannot be defined unconditionally.

The electrolytic solution used in the present invention is usually one in which the cation salt of the present invention is dissolved in a non-aqueous organic solvent. The organic solvent mentioned here is preferably one that is aprotic and has a high dielectric constant. Specific examples include, but are not limited to, glopyrene carbonate, γ-butyrolactone, dimethyl sulfoxide, dimethyl formamide, acetonitrile, ethylene carbonate, tetrahydrofuran, dimethoxyethane, methylformate, dichloroethane, etc. It's not a thing. These organic solvents may be used alone or as a mixed solvent of two or more. The concentration of the electrolyte cannot be unconditionally defined because it varies depending on the type of positive or negative electrode used, doping conditions, operating temperature, type of electrolyte, type of organic solvent, etc., but it is usually 0.001 to 10 mol/l. range.

By using the cation of the present invention, the acetylene polymer can be doped with a larger amount of cation than conventionally known cations without degrading the acetylene polymer. High polymers are most suitable for batteries using acetylene high polymers as electrodes and acetylene high polymers that require high electrical conductivity. The conductive acetylene polymer of the present invention is an n-type semiconductor, and is not only useful as various electric/electronic devices, but also can be combined with a p-type semiconductor to easily form a pn junction.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 [Manufacture of acetylene high polymer] Internal volume 500 m/! under nitrogen atmosphere! 5. into a glass reaction vessel. tmBls, o mmol) of titanium tetrabutoxide was added, dissolved in 20.0 ml of toluene, and 541n7! (40 mmol) of triethylaluminum was added with stirring to react, and a catalyst solution was prepared.

The reaction vessel was cooled with liquid nitrogen, the nitrogen gas in the system was evacuated using a vacuum pump, and then the reaction vessel was cooled to -78°C.

After rotating the reaction container to uniformly adhere the catalyst solution to the inner wall of the reaction container, immediately add 1
Polymerization was initiated by introducing purified acetylene gas at a pressure of atmospheric pressure. Simultaneously with the initiation of polymerization, an acetylene high polymer with metallic luster was deposited on the inner wall of the reaction vessel. The polymerization reaction was carried out at a temperature of -78° C. for 1 hour while maintaining the acetylene pressure at 1 atm, and then unreacted acetylene was evacuated with a vacuum pump to stop the polymerization. After removing the residual catalyst solution with a syringe under a nitrogen atmosphere, the i! was kept at −78 °C. Washing with 100 ml of purified toluene was repeated six times, followed by vacuum drying at room temperature.

A film-like acetylene high polymer having an area equal to that of the portion where the catalyst solution adhered to the inner wall of the reactor, a thickness of 90 μm, and a cis content of 98 was obtained.

The electrical conductivity (DC two terminal method) of this film-like acetylene polymer is 2.5 x 1. O-8Ω-”-c
m-' There was.

[Doping experiment]

From the acetylene polymer produced by the above method, the width is Q,
Cut out a small piece with a length of 5 cm and 20 c′rn,
A cathode electrode was mechanically crimped and fixed to a platinum wire, a platinum plate was used as the other electrode, and a propylene carbonate solution with a concentration of No-B F4 of 0.3 mol/e was used as an electrolyte. , omA) for 5 hours. After the doping was completed, the doped acetylene polymer film was washed repeatedly with propylene carbonate to obtain a doped acetylene polymer having a golden metallic luster. The composition of this doped acetylene polymer film was determined by elemental analysis [CH (No). −19]x
and its electrical conductivity (DC four terminal method) is 660
It was an n-type semiconductor of Ω-1·ctF'.

Comparative Example 1 The acetylene polymer obtained in Example 1 was used, except that Bu'nN-cj'0 was used instead of the nitrosonium salt used as the supporting electrolyte in the [doping experiment] of Example 1. Doping was carried out under the same doping conditions as in Example. The doped acetylene polymer was dark blue due to some oxidative deterioration. The composition of the doped acetylene polymer was determined by elemental analysis to be CCH(Bu' nN)o
s71]x, and its electrical conductivity is 12Ω-1・ff
1-1 n-type semiconductor.

Example 2 [Production of acetylene polymer] To 11 glass reactors completely purged with nitrogen gas, 200 ml of toluene purified according to a conventional method was added as a polymerization solvent.
A catalyst solution was prepared by sequentially charging mA, 294 mmol of tetrabutoxytitanium and 7.34 mmol of triethylaluminum as a catalyst at room temperature. The catalyst solution was a homogeneous solution.

The reactor was cooled with liquid nitrogen, and the nitrogen gas in the system was exhausted using a vacuum pump.

The reactor was cooled to -78° C., and purified acetylene gas at a pressure of 1 atmosphere was blown into the reactor while stirring the catalyst solution with a magnetic stirrer. At the beginning of the polymerization reaction, the entire system became agar-like, making stirring difficult. Acetylene gas pressure 1
The polymerization reaction was continued for 24 hours while maintaining the atmospheric pressure. The system was agar-like with a reddish-purple color. After polymerization,
Remove unreacted acetylene gas and lower the system temperature to -78°C.
Washing was repeated four times with 200 ml of purified toluene while maintaining the temperature. The solution remained slightly brown even after washing, and the catalyst was not completely removed. The gel-like acetylene polymer swollen in toluene was in the form of uniform chips with intertwined fibrous microcrystals, and no powder or lump-like polymer was produced.

A portion of the homogeneous gel was taken out and dried, and the amount of acetylene high polymer in the gel was measured, and it was found that the gel contained 10% of the acetylene high polymer by weight.

The above gel-like material is 10 mm thick and 1 mm long. Q Ortrm
, placed in a 50 mm width mold, sandwiched between chrome-plated ferro plates, and press-formed at room temperature under a pressure of 100 kp/cm2 while removing toluene to form a flexible and strong film with a thickness of 5 mm. A molded product was obtained. This film-like molded product has an electrical conductivity (measured by the DC two terminal method) of 5×10
It was a p-type semiconductor of Ω·m.

[Doping experiment]

In place of the acetylene polymer used in Example 1, the film-shaped molded product obtained by the above method was used, and as the supporting electrolyte, NO2.c was used in place of the nitrosonium salt used in Example 1.
7? A doping experiment was carried out in exactly the same manner as in Example 1, except that doping was carried out for 7 hours using O4-, to obtain a golden film having a composition of CCH(NO2)b2o)x. This film was an n-type semiconductor with an electrical conductivity of 4F; 0Ω.Example 3 The acetylene polymer obtained in Example 1 was used instead of the nitrosonium salt used as the supporting electrolyte in Example 1. N2
Doping was carried out in the same manner as in Example 1 except that H, AsF; was used, and the composition was [CH(
A golden film of N,,H5)o,+ao″lX was obtained.The electrical conductivity of this film was 790Ω・cln−
It was a No. 1 n-type semiconductor.

Example 4 Example 2 was used instead of the acetylene polymer used in Example 1.
Using a film-shaped molded product of acetylene high polymer obtained in
[Doping experiment] was carried out in exactly the same manner as in Example 1 except that N2H5.PF6 was used instead of the nitrosonium salt used in Example 1 as the supporting electrolyte, and the composition was CC.
H(N2H5)0. A golden film of +7[+]x was obtained. This film was an n-type semiconductor with an electrical conductivity of 530Ω·node.

Patent applicant: Showa Denko Co., Ltd. Agent: Patent Attorney Sei Kikuchi

Claims (1)

[Claims] In the acetylene polymer (1) nitrosonium ion (No. 2) (II)
An electrically conductive acetylene polymer electrochemically doped with at least one cation selected from nitronium ions (N02) (II) and hydrazonium ions (N2 H5).