JPS618344A - Polythiophene composite film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a conductive polymer film. More specifically, there is a metal or company metal between the base made of plastic film! This invention relates to a polythiophene composite film in which a conductive layer made of a thin oxide film is interposed.

[Prior art]

Conventionally, for example, a transparent conductive film in which plastic is coated with indium oxide as a metal oxide has been described in US Pat. No. 2.93a590. or,
For example, G, Tourillon and Fs G
ar-nIer: J, Electroa
nal, Ch'em, + 135 (1982) 173-
178, etc., it is described that conductive polymers such as polypyrrole, polythiophene, and polyfuran are formed electrochemically on metals such as platinum and gold, or metal oxides such as tin oxide and indium oxide. ing.

These conductive polymers, which have extremely high conductivity and whose value can be controlled arbitrarily by doping, are used not only as new conductive materials, but also in applications such as solar cells, rechargeable secondary batteries, and optoelectronic devices. Polythiophenes have been attracting attention from the viewpoint of various applications, especially from the viewpoint of stability of performance. (Example: G,
Tourillonand F, Garnler;
J, Electrochem, Soc: El
e-ctrochemical 5science a
nd Technology Vot, 130, No.
, 100ctober 1983, p, 2042 2
044) As a method for polymerizing conductive polymers, the electrolytic polymerization method is particularly important because a film of any thickness can be obtained. (Example: Yokei, Yoshino; Functional Materials 198
(April 4, p. 8) As a proposal that seems to be related to these findings, for example, a conductive polymer obtained using a metal oxide as an anode can be easily peeled off from the anode, so it can be formed into a film without being damaged. A conductive or semiconductive polymer composition of % is obtained.
-196232), or alternatively, a conductive or semiconductive polymer composition electrolytically oxidized with a thin film metal or metal oxide semiconductor anode supported on a substrate made of a resin composition or glass can be peeled off from the anode. There have been reports that it is easy to obtain products with arbitrary shapes and areas, and in particular, products with large areas can be obtained easily (Japanese Patent Application Laid-Open No. 58-213'027'), but all of these are conductive. The polymer cannot be peeled off from the anode in the form of a film and used alone.

However, when using a conductive polymer film alone, for example, when it is used as a material for a rechargeable and dischargeable secondary battery, especially an aggregate battery type, it is necessary to combine it with the material constituting the insulating layer. There are usage problems such as the need to prevent internal short circuits, and inconveniences such as the need to use a film that is thicker than required for functionality because the conductive polymer film itself lacks mechanical strength. When used as a material for optoelectronic elements, glass must be used as a support, which has problems and drawbacks such as lack of flexibility and easy breakage.

In addition, in connection with the method for producing a film-like polymer of virol,
[It is possible, but not necessary, to separate the precipitated (virol) film-like polymer from the anode active material. Therefore, a method of operation using the anode active material in the form of a finite belt is desirable, especially when the resulting polymer film is to remain on the anode active material at all times. ” (
JP-A-59-23889) has proposed polythiophene, which has very stable quality as an industrial material and requires a much higher applied voltage than polypyrrole in electrolytic polymerization, but to date, it has not been shown that it is electrically conductive. They have only been used with polymer films alone or with supports such as glass plates, and their problems and drawbacks have remained unresolved.

[Purpose of the invention]

The present invention was developed as a result of research aimed at solving the drawbacks and problems that conventionally existed when a conductive polymer made of polythiophene was used as a support using a single film or glass. We found that all of these problems could be solved by using a film and using polythiophene as an integral part of the non-conductive plastic film that serves as the base, without peeling it off. Based on this, various studies have been carried out and the present invention has been completed.

The borothiophene composite film of the present invention, in which a thin conductive layer made of a metal or metal oxide is interposed between a substrate made of a non-conductive plastic film, can be used to form a conductive polymer film of any shape and area. In addition, it also provides toughness, flexibility, and ease of handling by being integrated with a plastic film, which is a useful feature not found in conventional conductive polymer films alone. By using a non-conductive plastic film as a base that has excellent chemical resistance against organic solvents, acids, alkalis, etc., it can be used as a material for rechargeable and dischargeable secondary batteries, for example, as an insulating layer and support material. It provides an electrode active material that has both functions, and by selecting a transparent non-conductive plastic film, it does not require a support such as glass.
Japanese Journal of appli
edPhysics Vot, 22, N013, ma
rch 1983 pp L157-Li2S provides a suitable material for electronic devices such as optoelectronic elements.

[Structure of the invention]

The present invention is a polythiophene composite film characterized by having a substrate made of a non-conductive plastic film, a thin conductive intermediate layer made of a metal or metal oxide, and a surface layer made of a thin film of polythiophene or its derivative. .

The non-conductive plastic film used in the present invention is obtained by conventional extrusion molding, calender molding by cast molding, etc., such as polyether ether ketone (PEEK), fluorine resin, polyether sulfone (PES). , polyetherimide (PEI), polysulfone (PSF), polyphenylene sulfide (P
PS) etc. These films can be used either with treatments to strengthen the bond with thin conductive layers of metals or metal oxides, or without any particular treatment. It will be done.

Polythiophene is much more stable in air than other conductive polymers such as polyacetylene and polypyrrole, so it is not only expected to be a new conductive material, but also when it is doped or dedoped with impurities. Various applications are expected using the functions shown below. for example,
Electrochemical doping and dedoping of polythiophene is attracting attention for its use as a material for rechargeable and dischargeable secondary batteries and optoelectronic devices. Thus, when polythiophene is used as an active material in a redox reaction, chemical resistance to organic solvents, acids, alkalis, etc. is an essential condition.

Conventionally, it has been known to form a conductive polymer film by electrolytic oxidation on a polyester film coated with indium oxide or the like in the form of a thin film. However, polyester films do not have sufficient chemical resistance and are unreliable in terms of performance when used as an active material for redox reactions in the form of an integrated conductive polymer.

In the present invention, by using a non-conductive plastic film with sufficiently high chemical resistance as a substrate, it is possible for the first time to take advantage of the excellent performance of polythiophene while using it as an active material in redox reactions. A suitable polythiophene composite film was obtained.

The film made of PEEK and its derivatives used in the present invention is preferably a stretched film. or,
Specific examples of fluororesin films (including stretched ones) include the following, but are not limited thereto.

Polyvinyl fluoride (PVF), polyvinylidene fluoride (PVdF), polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene Fluoroethylene/perfluoroalkyl vinyl ether copolymer (PFA).

Examples of the metal or metal oxide used in the present invention include, but are not limited to, the following substances.

Metals: gold, platinum, palladium, rhodium, nickel, and alloys based on these.

Substances containing impurities in these compounds such as metal oxides tin dioxide, indium oxide, zinc oxide, vanadium pentoxide and ITO (indium tin oxide).
'If transparency is required, tin oxide, indium oxide, etc. are preferably ITO or the like.

In the present invention, polythiophene or a derivative thereof is formed by interposing a thin film of metal or metal oxide between a non-conductive plastic film and forms a conductive polymer film together with these materials. For example, it is synthesized from the following compounds by a known electrolytic polymerization method, but is not limited to this, and it is also synthesized as an additive. It is meant to include dopants that are present within the polythiophene and form a part of the polythiophene.

Thiophene, 3-methylthiophene, 3,4-dimethylthiophene, 3-bromothiophene, 3,4-dibromothiophene, 2,2'-bithiophene.

〔Effect of the invention〕

Since the polythiophene composite film according to the present invention is used together with a non-conductive plastic film, it has the excellent physical properties of a plastic film, such as heat resistance,
As a result of strengthening the toughness against environmental changes by utilizing cold resistance and mechanical properties, it is possible to increase the film thickness of polythiophene even in the thin film range that was difficult to handle with conventional polythiophene alone. It can be used with the minimum thickness required for functionality, and by selecting a transparent, non-conductive plastic film, it does not require a support such as glass, and is highly resistant to breakage. It is safe, lightweight, and suitable as a material for optoelectronic devices of arbitrary shapes and areas.

Furthermore, by using a non-conductive plastic film with excellent chemical resistance as a base material, it can be used as a material for chargeable and dischargeable secondary batteries and electronic devices, for example, as an oxidation film that combines the functions of an insulating layer and a support. It is also suitable as a material that can be used as a reduction reaction active material.

〔Example〕

(1) LiBF4 (0.2 mol/t) and thiophene monomer (0.2 mol/t) are dissolved in acetonitrile to make an electrolyte, and a PEEK conductive film on which ITO has been deposited in advance as an electrode and a nickel plate as a counter electrode are inserted into this. However, when a voltage of 10 μ was applied so that the PEEK conductive film served as an anode, a current of about 8 mA/i flowed, and a good composite film of PEEK/ITO film/polythiophene was obtained. The conductivity of the polythiophene layer immediately after polymerization by the four-probe method is approximately 30 S/cff! Met.

(2) NaPF6 (0,2 mot/L) and thiophene monomer (0,2 mat/t) were dissolved in benzonitrile to make an electrolyte, and this was used as an electrode using polychlorotrifluoroethylene L/L, which was pre-plated with nickel.
7. Insert a nickel plate as a counter electrode to the (PCTFE) conductive film, and hold it for 20 minutes so that the PCTFE conductive film becomes the anode.
When a voltage of V was applied, a current of about 20 mA/all flowed, and a good composite film of PCTFE/nickel layer/polythiophene was obtained. The conductivity of polythiophene immediately after polymerization by the four-terminal method was about 1005/ctn. Polyether sulfone (PES) on which ITO was pre-deposited was used as an electrode.
) Insert a nickel plate as a conductive film and a counter electrode,
When a voltage of 20V is applied so that the PES conductive film acts as an anode, approximately 15mA/c! A current of about 0,
When 3 coulombs were flowed, a composite film of blue polythiophene and PES conductive film with a thickness of approximately 1 μm was obtained. After the formation, the polythiophene layer turned red when it was dedoped by applying a voltage of opposite polarity. FIG. 1 shows changes in the light absorption spectrum due to doping and dedoping of this thin film.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the optical properties of a polythiophene composite film obtained according to the present invention.

Claims (1)

[Claims] A polythiophene composite film comprising a substrate made of a non-conductive plastic film, a thin conductive intermediate layer made of a metal or metal oxide, and a surface layer made of a thin film of polythiophene or its derivative.