JPS6136360A - Electrically conductive high polymer film having improved transparency and production thereof - Google Patents

Abstract

PURPOSE:To obtain a high polymer film useful for electrically conductive antistatic packaging films having good transparency, etc., by bringing a high polymer film into close contact with an electrode having regular small-gage wiry electrically conductive sites, and carrying out electrolytic polymerization of an aromatic compound. CONSTITUTION:A patterend insulator is provided in the surface of an electrode to leave small-gage wiry gaps having <=10mum width, and a high polymer film, e.g. polyvinyl chloride, is brought into close contact with the surface. The electrolytic polymerization of an aromatic compound, e.g. pyrrole or 3-methylpyrrole, is then carried out on the resultant electrode with the film to give the aimed electrically conductive film having the compounded electrolytic polymer of the aromatic compound in the high polymer film.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improved conductive polymer film with good transparency and its manufacturing capability.

[Conventional technology]

Certain aromatic compounds can be found in solvents added to electrolyte materials [! A conductive polymer film can be formed on all electrode substrates by electrolytic oxidation. As such aromatic compounds, heterocyclic compounds such as viroles and thiophenes, and polycyclic aromatic compounds such as azulene and pyrene%11 phenylene are known [for example, J.

Bourbon (J, Bargon), 8. Momad (
8, Moh-maM), R,J, Qualtoma7 (R
J, Waltman), IBM Journal Op Research End Development (IBM Jo
urnalof Research & Develop
ment) Volume 27, Issue 4, Page 330 (1985
(See 2013).

However, conventional highly conductive polymer films formed by direct electrolytic oxidation on electrode substrates have the following drawbacks.

(1) The mechanical strength of the film is weak, and especially in a thin film state, it is easily torn and difficult to handle, both on a substrate and when isolated as a film.

(2) It was difficult to control the electrical conductivity.

(3) The moldability of the film was poor.

(4) Transmittance of visible light was extremely low.

In order to eliminate these drawbacks, the present inventors have already developed a new conductive film and its manufacturing method (Japanese Patent Application No.
No. 8-186991, No. 58-213201, No. 58
-213205, 58-213204). In other words, a conductive polymer film produced by electrolytic polymerization usually consists of gold as an electrode substrate, an aromatic compound serving as a monomer for electrolytic polymerization in an organic solvent such as acetonitrile, an electrolyte for conducting electricity, and a bath solution dissolved in a gold bath. It is formed by inserting it together with a counter electrode and applying electricity between both electrodes. At this time, if the electrode substrate is coated with an insulating polymer film, it will naturally not be possible to conduct electricity and a strong conductive film will not be formed. However, the present inventors applied various polymer films on the electrode substrate and combined them with an appropriate electrolytic reaction solution that does not cause tS decomposition, so that the Vtt decomposition reaction proceeds in the same way as on ordinary electrodes. I found out everything. By using this method, various conductive polymer films with improved film strength, uniformity, etc. can be obtained, and electrical conductivity can also be controlled.

'Also, when making an insulating polymer film fully conductive using this method, what is the electrolytic polymerization time? If the length is short, the electrical conductivity cannot be very high, but a semiconductive film with high light transmittance can be obtained. These films can be expected to have industrially useful uses such as high transmittance antistatic films.

[Problem that the invention seeks to solve]

However, when the film thickness reaches a practical value of 20 μm or more, if the depolymerization time is short, only the film surface that is in contact with the electrode surface becomes conductive, and the entire film cannot be fully conductive, resulting in a high transmittance semiconductor film. There are many problems when using it as

On the other hand, if one attempts to impart conductivity to the opposite surface with such a film thickness, the electrolytic polymerization time must be lengthened, resulting in a decrease in light transmittance.

The present invention has been made to solve the problems of the prior art, and its purpose is to provide a conductive polymer film with excellent transparency and a complete method for manufacturing the same.

[Means for solving problems]

To summarize the present invention, the first invention relates to a highly conductive polymer film with excellent transparency. The molecular film is characterized by having regular, thin, highly conductive moieties.

The second invention of the present invention relates to a method for producing a polymer film with excellent transparency and good conductivity, which includes all 5 steps of electrolytic polymerization of an aromatic compound and peeling off the film after electrolytic polymerization from the electrode. It is characterized by including each step of the process.

Electrolytic polymerization of the aromatic compound is performed on the electrode with the polymer film fully adhered, and the polymer film and the electrolytic polymer of the aromatic compound are combined to form a highly conductive polymer film K 4J 6
In this case, current concentration occurs at the edges or defective areas of the electrode, causing electropolymerization to proceed faster and causing significant non-uniformity in the electrical conductivity of the film.

The present inventors have discovered that a conductive polymer film with high p1 light transmittance can be obtained by making full use of this phenomenon and regularly providing areas on the electrode where such current concentration tends to occur.几.

Hereinafter, the present invention will be specifically explained based on all the accompanying drawings.

FIG. 1 is a process diagram of one example of the manufacturing method of the present invention. In FIG. 1, the reference numeral 1μ electrode, 2 a battened insulator, 5 an insulating polymer film, and 4 all electrically conductive polymer films. Also, FIG. 2 shows regular thin line-shaped conductive parts according to the present invention. It is a schematic diagram of an example of an electrode button 01. First, FIG. 1 shows a typical manufacturing example of the electrode used in the present invention. A thin linear gap is left on the surface of the low-resistance electrode 1, and the whole insulator 2 is made of leather, and a polymer film tm is placed on this surface.

When electropolymerization of aromatic compounds is performed on such an electrode,
Electric current is concentrated in the thin wire gap portion, electrolytic polymerization progresses, and a conductive path is formed up to the film surface WJK. At the same time, electrolytic polymerization slightly progresses in the lateral direction as well. By stopping electrolytic polymerization at an appropriate polymerization time, the area near the thin wire gear lug becomes highly conductive and deeply colored, but the middle area of the gap has low conductivity but high light transmittance. . Therefore, the film as a whole can have a considerable degree of light transmittance, and in particular, when it is used to make a transparent film for preventing static electricity, all objects inside can be clearly seen. In addition to the electropolymerization conditions, the light transmittance can also be controlled by controlling the width of the a-line gap and its pitch interval.
It can be changed. This interval needs to be optimized taking into account the thickness of the film to be made conductive.

In order to make the electrical conductivity and light transmittance uniform in the plane of the film, it is necessary to provide thin wire gaps evenly and regularly throughout the film. It is effective to arrange them in a nest-shaped or hexagonal structure.

The thin linear gap that causes current concentration is 10 μm.
Below, a thickness of 5 μm or less is particularly effective. On the other hand, the pitch μ between the gaps and the thickness # of the conductive polymer film are desirable, and sufficient light transmittance is often not exhibited unless the pitch is at least 20 μm.

Such electrodes can be fabricated on a suitable conductive surface using conventional photolithography techniques.

The material for the electrode surface is noble metals such as gold, platinum, and palladium, conductive metal oxides such as tin oxide and indium oxide, or base metals such as chromium, nickel, and stainless steel. A combination can be used.

In addition, the resist material itself can be used as an insulator to create a thin line-shaped gap on the electrode conductor surface, but it cannot withstand repeated use because it easily peels off when the film is repeatedly made and peeled off. . Ninth, it is preferable to use an insulating oxide such as SiO or 8103, or a nitride such as Si, N, BN, etc., with a high adhesion strength <t>7t.

In order to form a thin line-shaped conductive portion, a photomask that completely blinds such a pattern is used to completely transfer the resist layer, and a batten is formed using an insulator on this base by lift-off or etching.

Electron beam exposure or Xlj transfer technology may be used for K to completely form a gap of 2.0 .mu.n@ or less.

Examples of polymer films that can be made conductive in the present invention include polyvinyl chloride resins, that is, polyvinyl chloride, vinyl chloride and various vinyl esters, vinyl ethers, acrylic acid and its esters, methacrylic acid and its esters, maleic acid, etc. Copolymers with monomers such as acids and their esters, fumaric acid and its esters, maleic anhydride, aromatic vinyl compounds including styrene, vinylidene compounds, acrylonitrile, methacrylonitrile, propylene, etc. Use 'f! Ru. 'Also,
Copolymers of vinylidene chloride and various vinyl esters, vinyl ethers, acrylonitrile, methacrylonitrile, vinyl chloride, etc., as well as copolymers of polyethylene and ethylene with the above-mentioned various monomers, can also be used.

Depending on the purpose, polyvinylidene fluoride, polyvinyl fluoride, polycarbonates, various nylons, polyethylene terephthalate, polyetherimide, polysulfone, polyimides, and various rubbers can also be used.

Furthermore, a film containing all of the above resins including a plasticizer, heat stabilizer, lubricant, ultraviolet absorber, anti-corrosion agent, pigment, dye, surfactant, etc. can also be used.

Further, aromatic compounds that can be electrolytically polymerized include virol, 5-methylvirol, N-/? rubirol, thiophene, 6-methylthiophene, furan, phenol, thiophenol, selenophene, tellurophene, biphenyl, azulene, p-1-phenyl, 0-terphenyl, p
-quarterphenyl, 2-hydroxypiphenyl, diphenyl sulfide, 2-(α-chenyl)thiophene,
2-(α-chenylumfuran, 2-(2-pyrrolyl)virol, 2-(2-pyrrolyl)thiophene, 2-phenylthiophene, α-chenylphenyl ether, β-furyl-α-chenylselenide, 2-( 2-pyrrolyl) selenophene, 2-(2-selenienyl) tellurophene,
N-vinylcarbazole, N-ethynylcarbazole,
Aromatic compounds such as methyl azulene and pyrene can be used. Also, various substituted butadiene compounds, although not aromatic compounds, can also be used.

Furthermore, various compounds such as organic quaternary ammonium salts, inorganic salts, proton powders, and esters can be used as electrolytes during electrolytic polymerization. As a solvent, all acetonitrile-based solvents can be used for electrolytic polymerization of aromatic compounds.
Any material can be selected as long as it dissolves an appropriate electrolyte.

〔Example〕

The present invention will be explained in more detail with reference to all the examples of the BA of the present invention, but the present invention has infinite combinations by changing the polymer film material, the type of aromatic compound to be electrolytically polymerized, the structure of the film, etc. Therefore, the present invention is not limited to these examples.

Example 1 A Nesa glass substrate with a surface resistance of 10 Ω/- was used as an electrode. On top of this, photoresist Z-1550J (manufactured by Shipley) was spin-coded to a thickness of 1.2 μm, and a second
Using a photomask having a shape as shown in the figure with battens having a line width of 2 μm and an interval of 18 μm, the battens were transferred by contact exposure. After preparing Y cyst, α25 μm was obtained by thermal evaporation of 5Ioy.
By evaporating it to a thick thickness and lifting it off in acetone, the surface of the Nesa glass substrate was 810 mm thick, leaving a gap of approximately 2 μm width.
Insulated with.

A solution of polyvinylidene fluoride in N,N-dimethylformamide was cast on this to form a polyvinylidene fluoride film having a thickness of 20 μm.

On the other hand, as an electrolytic polymerization solution, virol (1.2 mol/l
), tetraethylammonium tetrafluoroporate (α5 mol/l) and acetonitrile-ethyl alcohol (2:1) solution was prepared.

The electrode with the film was immersed in this solution, and electrolytic polymerization of virol was carried out at 5 V for 2 minutes using the platinum mesh as an electrode facing all sides.

After electropolymerization, the film could be easily peeled off from the electrode, and the resistance and light transmittance at 600 nm of the film were measured, and the results shown in Table 1 were obtained.

Table 1 111 The back side of the metal plate in contact with the electrode surface, and the opposite side is the front side. Furthermore, a mouth means one angle of view. (same as below) ! ! As is clear from 1, low sheet resistance and high light transmittance? An electrically conductive polymer film with excellent properties was obtained, and the entire film had electrical conductivity in the thickness direction.

Example 2 Using the same electrode as that used in Example 1, a mixed solution of polyvinyl chloride in tetrahydrofuran-methyl ether ketone was mixed to form a film with a thickness of 55 μm.

This film-coated substrate was immersed together with a platinum/Tsch counter electrode in a solution of thiophene (1 mol/1), tetraethelammonium barchlorate (+lL 5 mol/l), ffi-containing tr acetonitrile-nitrobenzene (1:1), and a 2-minute a.o.v. Electrolytic polymerization of thiophene was carried out. This film could be easily peeled off from the electrode substrate, and when the electrical conductivity and light transmittance (600 nm) t'' were determined, the results shown in Table 2 were obtained.

Table 2 As is clear from Table 2, even a relatively thick film of 55 μm had conductivity not only on both sides but also in the film thickness direction, and a film with high light transmittance was obtained.

〔Effect of the invention〕

As explained above, according to the present invention, when an aromatic compound is electrolytically polymerized with a polymer film in full contact with an electrode having regular thin line conductive sites, the polymer film in contact with the thin line conductive sites is A conductive electrolytic polymer is quickly generated from the molecular film portion, making the entire film conductive. Although the portions of the film thus obtained that are in contact with the thin lines are deeply colored, there is an advantage that a film with high light transmittance can be obtained as a whole by appropriately setting the electrolytic polymerization conditions. This conductive film with high light transmittance has useful industrial fields of use, such as antistatic packaging films and transparent conductive films for input/output devices.

[Brief explanation of the drawing]

FIG. 1 is a process diagram of an example of the manufacturing method of the present invention, and FIG. 2 is a schematic diagram of an example of an electrode pattern having regular thin line-shaped conducting portions according to the present invention. 1: Electrode, 2: Battered insulator, 5: Insulating polymer film, 4: Conductive polymer film

Claims (1)

[Claims] 1. A conductive polymer film in which an electrolytic polymer of an aromatic compound is composited in a polymer film, which is characterized by having highly conductive sites in the form of regular thin lines. A conductive polymer film with excellent properties. 2. A step of closely adhering a polymer film onto an electrode having regular thin line conductive parts, a step of electrolytically polymerizing an aromatic compound on the electrode with the film, and peeling off the electrolytically polymerized film from the electrode. 1. A method for producing a conductive polymer film with excellent transparency, the method comprising the steps of: