JPH0734225A - Production of conductive polymer/ion exchanger composite thin film - Google Patents

Abstract

PURPOSE:To form the subject composite thin film electrode having a high energy density by adding and uniformly dispersing an ion exchanger into a conductive polymer thin film through heating and vapor-depositing the conductive polymer and concurrently heating and vapor-depositing the ion exchanger under vacuum. CONSTITUTION:In a vacuum deposition device, the composite thin film consisting of a conductive polymer and an ion exchanger is formed by heating and vapor- depositing the conductive polymer such as polyaniline and concurrently heating and vapor-depositing the ion exchanger such as methanesulfonic acid on a substrate such as glass to add and uniformly disperse the ion exchanger into a conductive polymer thin film on the substrate. At the time of heating and vapor-depositing the conductive polymer and the ion exchanger, the respective vapor deposition rates and the ion exchanger content in the conductive polymer are controlled by adjusting the respective heating temp. Thus the composite thin film having a high energy density can be produced by this single-stage process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a conductive polymer / ion exchanger composite thin film in which an ion exchanger is uniformly dispersed and contained in a conductive polymer thin film, and more particularly to a thin film type high energy density polymer. The present invention relates to a method for manufacturing the thin film, which can be used as an electrode of a battery and as an electrode of an electronic element, a semiconductor element, or the like.

[0002]

2. Description of the Related Art As a method for producing a polymer thin film in a vacuum by a vapor phase method, a sputtering method {R. Harrup et
al., Thin Solid Film, 3, 109-, (1969), T. Robertson
et al., Thion Solid Film, 27, 19-, (1975)} and plasma polymerization method {M.Shen Ed., Plasma Chemistry of Polymer
s, Marcel Dekker Inc., (1976), ATBell et al., ACS
Symposium Seriex 108, ACS Washington, (1979)} is known, but it has the drawback that a polymer thin film having the desired chemical structure cannot be obtained because the raw material molecules are decomposed and degraded during the thin film formation process. There is. Recently, a method for producing a polymer thin film having a desired chemical structure by heating and evaporating a polymer in a vacuum {T. Yamamoto et al., Synthet
ic Metals, 38, 399-402, (1990)} has been proposed, but high conductivity cannot be obtained only with this polymer thin film, and it is necessary to perform doping after forming the thin film.

[0003]

In order to impart a conductive function to the polymer thin film deposited in vacuum as described above, it is necessary to perform doping by a wet method after forming the thin film, and the dopant is diffused in the polymer thin film. Since it takes a long time to complete the doping, it takes a considerable time to complete the doping. Wet method (casting method)
Therefore, it is difficult to uniformly disperse the ion exchanger into a thin film to obtain a conductive polymer / ion exchanger composite thin film, and there is a problem that aggregation of the insoluble substance and nonuniformity occur. In addition, when synthesizing a conductive polymer, a conductive polymer / ion exchanger composite can be obtained by mixing an ion exchanger with a monomer and performing a polymerization reaction, but the synthesized composite is an organic solvent. Since it is insoluble, it was difficult to form a thin film.

In view of the above-mentioned state of the art, the present invention is to provide a method for producing a conductive polymer / ion exchanger composite thin film in which an ion exchanger is uniformly dispersed.

[0005]

According to the present invention, in a step of forming a thin film by heating and depositing a conductive polymer in a vacuum, the ion-exchange material is simultaneously heated, so that the ion exchange is performed in the conductive polymer thin film in one step. The method is characterized by forming a conductive polymer / ion exchanger composite thin film containing a body uniformly dispersed therein.

In the present invention, the conductive polymer is 1 × 10 ^-4.
A thin film is formed by vapor deposition by heating to about 70 to 400 ° C. in a vacuum of about 1 × 10 ⁻⁶ Torr.
The heating temperature of the conductive polymer varies depending on the polymer used and the degree of vacuum at the time of vapor deposition, but a temperature lower by about 10 to 50 ° C. than the thermal decomposition temperature at 1 atm in an inert gas atmosphere is suitable. For example, the thermal decomposition temperature of polyaniline is around 350 ° C. to 420 ° C., but 1 × 10 ⁻⁵
With a degree of vacuum of about Torr, it is preferable to heat at about 330 to 370 ° C.

Even with a conductive polymer other than the above, it is possible to form a polymer thin film on an arbitrary substrate in a vacuum by heating at a thermal decomposition temperature of 1 atm or less. However, if heated to a temperature that is too close to the thermal decomposition temperature, a thin film with a structure different from the chemical structure of the raw material polymer may be formed or it may be impossible to form a thin film. It is preferable to perform heat vapor deposition at a low temperature.

The ion exchanger referred to in the present invention means an organic low molecular weight substance having a sulfonic acid group, such as an alkyl sulfonic acid or a low molecular weight sulfonic acid. The heating temperature of the ion exchanger is a temperature at which the vapor pressure of the ion exchanger serving as a vaporization raw material shows a vapor pressure similar to the degree of vacuum during thin film formation,
It is usually in the range of 200 to 500 ° C. For example, in the case of methanesulfonic acid, 100 at a vacuum degree of 1 × 10 ^-5 Torr
℃ to 120 ℃, in the case of ethanesulfonic acid, 1 × 10
^-5 Torr vacuum degree from 150 ° C to 170 ° C, and in the case of ethanedisulfonic acid, 2 × 10 ^-5 Torr vacuum degree.
From 00 ° C to 220 ° C, and in the case of butanedisulfonic acid, from 250 ° C to 270 at a vacuum degree of 1 × 10 ^-5 Torr.
It is preferred to heat to ° C. Ion exchangers other than the above can be vapor-deposited by heating to a temperature at which the vapor pressure of the ion exchanger serving as the evaporation source is similar to the vacuum level at the time of thin film formation.

When the conductive polymer and the ion exchanger are heated and vapor-deposited at the same time, it is possible to control the vapor deposition rate by controlling the respective heating temperatures and to control the ion-exchanger content in the electroconductive polymer thin film. it can. For example,
When the deposition rate of the conductive polymer is slowed down to increase the deposition rate of the ion exchanger, the ion exchanger content is high. Conversely, when the deposition rate of the conductive polymer is increased and the deposition rate of the ion exchanger is decreased, the ion exchanger content becomes low.

As a method of heating the vapor deposition source, resistance wire heating, lamp heating, electron beam heating, laser heating and the like can be used, but resistance wire heating or lamp heating is preferable because precise temperature control is required. . In this case, since there is a temperature difference between the vapor deposition source of the polymer and the vapor deposition source of the ion exchanger, in order to avoid the effect of secondary heat in the vacuum vapor deposition equipment, separate the vaporization source in the equipment with a partition plate, etc. It is preferable to minimize the influence of the heating temperature of both. As the evaporation source container, any container that can be heated up to about 500 ° C., such as Pyrex glass, quartz glass, or a ceramics container can be used. Further, a tungsten basket, a tungsten boat, a platinum boat, or the like used in ordinary vacuum vapor deposition can also be used, and there is no particular limitation as long as the material does not react with the evaporation raw material.

There are no particular restrictions on the material of the substrate, and glass, inorganic crystals, ceramics, metals, polymers and the like can be used. If the substrate temperature during vapor deposition is higher than the heating temperature of the conductive polymer or ion exchanger, the vapor-deposited thin film may re-evaporate. Therefore, the substrate temperature is 50 ° C. higher than the heating temperature of the conductive polymer or ion exchanger. It is preferable that the temperature is lower than about 100 ° C. or lower.

[0012]

The present invention has made it possible to uniformly disperse and complex an ion exchanger in a conductive polymer thin film.
In addition, until now only a polymer thin film having a low conductivity has been obtained only by heating and depositing a conductive polymer,
By simultaneously depositing a conductive polymer and an ion exchanger that is a dopant, it is possible to form a conductive polymer / ion exchanger composite thin film in one step. For example, by simultaneously heating and vapor depositing polyaniline, which is a conductive polymer, and methanesulfonic acid, which is an ion exchanger,
Conductive polymer with conductivity of about 2 × 10 ^-3 S · cm ^-1 /
An ion exchanger composite thin film could be formed.

[0013]

【Example】

Example 1 Using polyaniline synthesized by an oxidative polymerization method and commercially available methanesulfonic acid as raw materials, polyaniline was heated to 350 ° C. under a vacuum degree of 1 × 10 ⁻⁵ Torr by a resistance heating method in a vacuum deposition apparatus. 1 methanesulfonic acid
Simultaneous heating vapor deposition at 10 ° C, thickness 40 nm on glass substrate
A thin film of a degree was obtained. As a result of measuring the conductivity of the obtained thin film by the 4-terminal method, a conductivity of 2 × 10 ⁻³ S · cm ⁻¹ was obtained.

(Example 2) Polyaniline synthesized by an oxidative polymerization method and commercially available ethanesulfonic acid were used as raw materials in a vacuum vapor deposition apparatus by a resistance heating method to obtain a degree of vacuum of 1 × 10 ^-5 To.
Under the condition of rr, polyaniline was simultaneously heated and vapor-deposited at 350 ° C. and ethanesulfonic acid at 170 ° C. to obtain a thin film having a thickness of about 30 nm on a glass substrate. As a result of measuring the conductivity of the obtained thin film by the 4-terminal method, a conductivity of 2 × 10 ⁻³ S · cm ⁻¹ was obtained.

Example 3 Polyaniline synthesized by an oxidative polymerization method and commercially available sodium ethanedisulfonate were ion-exchanged with a cation exchange resin as a raw material, and ethanedisulfonic acid was used as a raw material. Under the conditions of × 10 ^-5 Torr, polyaniline is added to 350
At the same time, ethanedisulfonic acid was simultaneously vapor-deposited at 220 ° C. to obtain a thin film having a thickness of about 30 nm on a glass substrate. The conductivity of the obtained thin film was measured by the 4-terminal method, and was 1 × 1.
A conductivity of 0 ⁻³ S · cm ⁻¹ was obtained.

(Example 4) Polyaniline synthesized by an oxidative polymerization method and commercially available sodium butanedisulfonate ion-exchanged with a cation exchange resin were used as a raw material, butanedisulfonic acid was used as a raw material, and a vacuum degree of 1 was obtained by a resistance heating method in a vacuum deposition apparatus. Under the conditions of × 10 ^-5 Torr, polyaniline is added to 350
Butanedisulfonic acid was simultaneously heated and vapor-deposited at 270 ° C. to obtain a thin film having a thickness of about 30 nm on a glass substrate. The conductivity of the obtained thin film was measured by the 4-terminal method, and was 1 × 1.
A conductivity of 0 ⁻³ S · cm ⁻¹ was obtained.

Example 5 Using polypyrrole synthesized by the oxidative polymerization method and commercially available methanesulfonic acid as raw materials, the degree of vacuum was 1 × 10 ⁻⁵ To by a resistance heating method in a vacuum deposition apparatus.
Under the condition of rr, polypyrrole was simultaneously heated and vapor-deposited at 450 ° C. and methanesulfonic acid at 110 ° C. to obtain a thin film having a thickness of about 40 nm on a glass substrate. As a result of measuring the conductivity of the obtained thin film by the 4-terminal method, a conductivity of 1 × 10 ⁻³ S · cm ⁻¹ was obtained.

Example 6 Using polypyrrole synthesized by the oxidative polymerization method and commercially available ethanesulfonic acid as raw materials, the degree of vacuum was 1 × 10 ⁻⁵ To by a resistance heating method in a vacuum vapor deposition apparatus.
Under the conditions of rr, polypyrrole was simultaneously heated and vapor-deposited at 450 ° C. and ethanesulfonic acid at 170 ° C. to obtain a thin film having a thickness of about 30 nm on a glass substrate. As a result of measuring the conductivity of the obtained thin film by the 4-terminal method, a conductivity of 8 × 10 ⁻⁴ S · cm ⁻¹ was obtained.

Example 7 Using polythiophene synthesized by an oxidative polymerization method and commercially available ethanesulfonic acid as raw materials,
Vacuum degree of 1 × 10 ^-5 T by resistance heating method in a vacuum evaporation system
Under the conditions of orr, polythiophene and ethanesulfonic acid were simultaneously heated and vapor-deposited at 550 ° C. and 170 ° C. to obtain a thin film having a thickness of about 30 nm on a glass substrate. The conductivity of the obtained thin film was measured by the 4-terminal method, and was found to be 8 × 10 ⁻⁴ S · cm ^−1.
A conductivity of 10 was obtained.

(Example 8) Polythiophene synthesized by an oxidative polymerization method and commercially available sodium ethanedisulfonate were ion-exchanged with a cation exchange resin as a raw material, and ethanedisulfonic acid was used as a raw material. Under conditions of × 10 ^-5 Torr, polythiophene was mixed with 5
Simultaneous vapor deposition of ethanedisulfonic acid at 220 ° C. was performed at 50 ° C. to obtain a thin film having a thickness of about 30 nm on a glass substrate.
The conductivity of the obtained thin film was measured by the 4-terminal method, and was 5 ×.
A conductivity of 10 ⁻⁴ S · cm ⁻¹ was obtained.

Example 9 Polyparaphenylene synthesized by an oxidative polymerization method and commercially available sodium ethanedisulfonate were ion-exchanged with a cation exchange resin, and ethanedisulfonic acid was used as a raw material to produce a vacuum by a resistance heating method in a vacuum deposition apparatus. Polyparaphenylene was simultaneously heated and vapor-deposited at 600 ° C. and ethanedisulfonic acid at 220 ° C. under the condition of 1 × 10 ⁻⁵ Torr to obtain a thin film having a thickness of about 30 nm on a glass substrate. As a result of measuring the conductivity of the obtained thin film by the 4-terminal method, a conductivity of 7 × 10 ⁻⁴ S · cm ⁻¹ was obtained.

Example 10 Butadisulfonic acid obtained by ion-exchange of polyparaphenylene synthesized by an oxidative polymerization method and commercially available sodium butanedisulfonate with a cation exchange resin was used as a raw material, and a vacuum was applied by a resistance heating method in a vacuum deposition apparatus. Polyparaphenylene was co-evaporated at 600 ° C. and butanedisulfonic acid at 270 ° C. at a temperature of 1 × 10 ⁻⁵ Torr to obtain a thin film having a thickness of about 30 nm on a glass substrate. As a result of measuring the conductivity of the obtained thin film by the 4-terminal method, a conductivity of 5 × 10 ⁻⁴ S · cm ⁻¹ was obtained.

[0023]

According to the present invention, it is possible to uniformly disperse and complex an ion exchanger in a conductive polymer thin film. Further, by simultaneously depositing the conductive polymer and the ion exchanger, it is possible to form the electrode of the conductive polymer / ion exchanger composite thin film having a high energy density in one step.

Claims (1)

[Claims] 1. A conductive polymer characterized by uniformly depositing an ion exchanger in a conductive polymer thin film by heating and vapor depositing a conductive polymer at the same time as heating and vapor depositing an ion exchanger. Ion exchanger composite thin film manufacturing method.