JPS61211370A - Thin-film electrically conductive composition - Google Patents

Abstract

PURPOSE:To provide a thin-film electrically conductive compsn. which contains metals which are independent of each other and uniformly and finely dispersed therein, exhibits electrical conductivity by the addition of a small quantity of a complex and is suitable for use as an antistatic membrane, by heat-treating an org. polymer compsn. contg. an organometal complex. CONSTITUTION:An org. polymer (e.g. polystyrene, polyvinyl chloride or polymethyl methacrylate) soluble in solvent and an organometallic complex [e.g. di-mu-chlorobis(eta-2-methylallyl)dipalladium complex] are uniformly dissolved in a solvent (e.g. hexane or methyl alcohol). The solvent is then removed by coating or spraying to form a thin-film org. polymer compsn. contg. the organometal complex. The compsn. is heat-treated at 50-400 deg.C to obtain a thin-film electrically conductive org. polymer compsn. having a thickness of 20mu or less and contg. metals which are independent of each other and uniformly and finely dispersed therein.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an organic polymer thin film conductive composition in which metals are independently and uniformly finely dispersed.

Traditionally, organic polymer conductive compositions with metal dispersed in them are
A large amount is added to the organic polymer so that the metal fillers have some contact points with each other to impart electrical conductivity.

Therefore, when the metal filler is a particle, it is necessary to add a large amount of metal particles in order for the organic polymer composition to exhibit conductivity, and this reduces the moldability of the organic polymer conductive composition.
This results in a decrease in transparency and various physical properties.

Furthermore, when the metal filler is in the form of fibers or flakes, the amount added is considerably lower than that of metal particles, but due to the orientation, cutting, etc. of the fibers or flakes during molding of the organic polymer conductive composition, the conductivity It is difficult to obtain molded products with uniform physical properties due to directional properties.

On the other hand, as disclosed in Japanese Patent Application Laid-Open No. 57-202333, when metal fillers are dispersed independently of each other in an organic polymer, the polymer naturally becomes an insulator and can be used as a dielectric.

The present inventors have discovered that by heat-treating an organic polymer composition containing an organometallic complex, an organic polymer thin film composition in which metals are mutually independent and uniformly finely dispersed can be obtained; Surprisingly, they discovered that it exhibits electrical conductivity and completed the present invention.

The present inventors interpret these phenomena as follows.

That is, an organic polymer thin film composition in which metals produced by uniformly dissolving an organometallic complex in an organic polymer and then thermally decomposing the organometallic complex are independent of each other and uniformly finely dispersed, Since there is no change in electrical conductivity below the temperature near the glass transition point of coalescence, it is thought that tunnel hopping of electrons occurs between metal atoms and electrical conductivity is developed.

Furthermore, it has been found that the conductivity of the organic polymer thin film conductive composition of the present invention exhibits reversible and discontinuous values near the glass transition point of the organic polymer.

The organic polymer thin film conductive composition of the present invention in which metals are mutually independent and uniformly finely dispersed can be obtained by preparing a homogeneous solution containing an organometallic complex and an organic polymer, and removing the solvent. After forming an organic polymer thin film composition containing
It can be manufactured by heat-treating the composition.

The present invention will be explained in detail below.

The organometallic complex used in the present invention is selected from one that exhibits solubility in a solvent and releases metal upon heating,
It is represented by the general formula M, L, (m is an integer from 1 to 4, and n is an integer from 2 to 12).

Metal M is on the periodic table IVa, Vs -, VIA, ■4
, ■ and ■, each metal of group titanium, zirconium, vanadium, chromium, molybdenum, tungsten, manganese, rhenium, iron, cobalt, nickel, ruthenium, osmium, rhodium, palladium, iridium,
Platinum, copper, silver, gold, etc. are preferred.

Ligands include, for example, tertiary phosphines, tertiary phosphites, carbon oxides, linear or cyclic olefins, conjugated olefins, aryl compounds, organic cyano compounds, organic isonitrile compounds, and It can be selected from combinations of one or more of mercapto compounds and compounds having alkyl groups, vinyl groups, allyl groups, ethyridine groups, and acyl groups, and may also be atoms such as halogen, oxygen, hydrogen, and nitrogen.

The polymer used in the present invention must be soluble in the solvent - examples include polystyrene, polyamide,
Thermoplastic resins such as polycarbonate, polysulfone, polyethersulfone, polymethyl methacrylate, polyvinyl chloride, polyvinylidene fluoride and ABS resins, diallyl phthalate resins, unsaturated polyester resins, phenolic resins, epoxy resins and polyimide resins. Examples include cured thermosetting resins, as well as rubber-like unvulcanized resins such as silicone resins, polyurethane resins, and styrene-butadiene rubber.

The solvent used for dissolving the organometallic complex and organic polymer of the present invention may be any solvent as long as it can stably and uniformly dissolve the organometallic complex and organic polymer.

For example, hexane, cyclohexane, benzene, toluene, xylene, methyl alcohol, ethyl alcohol,
Examples include isopropyl alcohol, ethyl ether, dioxane, ethyl acetate, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, acetone, methyl ethyl ketone, pyridine, acetate, nitrile, dimethylformamide, dimethyl sulfoxide, etc., which may be used alone or in combination of two or more. It can also be used as

A homogeneous solution containing an organometallic complex and an organic polymer can be prepared by dissolving the organometallic complex and organic polymer in an appropriate solvent or uniformly mixing the organometallic complex solution and the organic polymer solution. I can do it.

Preparation of the homogeneous solution is usually preferably carried out at a temperature at which decomposition of the organometallic complex does not proceed much.

In addition, other additives such as stabilizers, plasticizers, and colorants can be optionally added depending on the purpose of use.

Using the homogeneous solution containing the organometallic complex and organic polymer prepared in this way, a film is formed by a coating method, a casting method, a spray method, a spinner method, a dipping method, etc., and the organometallic complex is formed by removing the solvent. An organic polymer thin film composition containing the complex is obtained.

By heating the organic polymer thin film composition containing this organometallic complex to a temperature at which the thermal decomposition of the organometallic complex sufficiently proceeds, an organic polymer thin film conductive composition in which the metals are mutually independent and uniformly finely dispersed is obtained. can be obtained.

The thermal decomposition temperature of the organometallic complex is selected to be a temperature at which the metal release reaction proceeds. Generally 50-400℃, usually 10
Temperatures from 0 to 250° C. are employed, and the temperature is selected so that thermal decomposition of the polymer does not proceed.

The metal content in the organic polymer thin film conductive composition is 0.0
A range of 0.01 to 40% by volume is effective, especially 0.002
~5% by volume is preferred.

Moreover, this case has the characteristic that a transparent organic polymer thin film conductive composition can be obtained.

Further, if the metal content is less than 0.001% by volume, the conductivity will be low, and if it exceeds 40% by volume, the shapeability will be poor.

The film thickness of the organic polymer thin film conductive composition of the present invention is 0.1
-20μ, preferably 1-10μ.

If it is less than 0.1 g, it will be difficult to produce a uniform thin film due to the occurrence of pinholes, etc., while if it exceeds 20 μ, the thin film composition will have a large resistance value and exhibit dielectric properties.

Applications of the organic polymer thin film conductive composition of the present invention include:
Examples include antistatic films (walls and floors of clean rooms), transparent electrodes for liquid crystals, IC packages, and switching elements that utilize changes in conductivity at the glass transition point.

Furthermore, the organic polymer thin film conductive composition of the present invention can also be produced, for example, by plasma polymerizing a polymerizable organic monomer in the presence of a metal.

The present invention will be described below with reference to Examples, but the present invention is not limited thereto.

Example 1 Di-μm chloro-bis(η-2-methylallyl)nipalladium(n) complex was added to a solution of 2.5 g of polycarbonate (Nipilon S-2000, manufactured by Mitsubishi Gas Chemical KK) dissolved in 40 ml of chloroform. In addition, 0.1% by weight and 1% by weight of palladium metal, respectively, based on polycarbonate.
% and 10% by weight solutions were prepared.

A glass plate coated with gold was immersed in these solutions and pulled up at a constant speed to form a film. Next, after drying at 60°C for 24 hours,
A heat treatment was performed at 200°C to liberate palladium metal. The thickness of the palladium metal-containing polycarbonate thin film composition produced on this glass plate was about 6 μm, and the palladium metal contents were about 0.01% by volume, 0.1% by volume, and 1% by volume, respectively.

Next, gold was deposited on the top surface of this palladium metal-containing polycarbonate thin film composition to form an electrode, and then the electrical conductivity (at room temperature) was measured between both surfaces of the film. The results are shown in Table 1.

In addition, the palladium metal content is 1% by weight (approximately 0.1% by volume).
) The conductivity of the polycarbonate thin film composition changed with temperature near the glass transition point of the polycarbonate, as shown in FIG.

Example 2 In the same manner as in Example 1, polycarbonate (manufactured by Mitsubishi Gas Chemical KK, Kneepilon S-2000) was treated with mites μm.
A chloroform solution containing 1% by weight of chloro-bis(η-2-methylrealyl)nipalladium (If) complex as palladium metal was prepared. A glass plate coated with gold is dipped in this solution and pulled up at a constant speed repeatedly.
After preparing polycarbonate thin film compositions with a palladium metal content of 1% by weight (approximately 0.1% by volume) and film thicknesses of approximately 6μ, 10μ, 12μ, 25μ, 39μ, and 44μ, respectively, the conductivity (room temperature) was measured. .

As shown in FIG. 2, the conductivity decreased when the film thickness exceeded 20 μm.

Table 1 Example 3 A di-μm chloro-bis(η-2-methylallyl)nipalladium l) complex was prepared using polymethyl methacrylate (manufactured by Tokyo Kasei KK, reagent grade 1, degree of polymerization 7000-7500).
Add 5 g of palladium metal to a solution of 40 ml of chloroform and add 1
A 0% by weight solution was prepared.

Next, in the same manner as in Example 1, a polymethyl methacrylate thin film composition with a film thickness of about 6 μm and a palladium metal content of 10% by weight (about 1% by volume) was prepared, and after heat treatment, a gold electrode was formed. Electrical conductivity (room temperature) was measured. Its conductivity is 3
X 10-'Scm-'.

The conductivity of the polymethyl methacrylate thin film containing no palladium metal was 1X10-''S-1.

Further, the electrical conductivity of this palladium metal-containing polymethyl methacrylate thin film composition changed with temperature near the glass transition point of polymethyl methacrylate, as shown in FIG.

Example 4 In the same manner as in Example 1, benzylchlorobis(triphenylphosphine)palladium (n
) A chloroform solution containing 1% by weight of the complex as palladium metal was prepared.

Next, in the same manner as in Example 1, a polycarbonate thin film composition having a film thickness of approximately 6 μm and a palladium metal content of 1% by weight (approximately 0.1% by volume) was prepared, and heat treated at 180°C to form a gold electrode. After forming, the conductivity (room temperature) was measured. conductivity is 1
, 7 X 10-70-7S'.

Incidentally, the electrical conductivity of the polycarbonate thin film containing no palladium metal was I x 10-0-1hSe'.

Example 5 In the same manner as in Example 1, G-8-
A chloroform solution containing 1% by weight of chlorotetracarbonylnirhodium (1) complex as rhodium metal was prepared.

Next, in the same manner as in Example 1, a polycarbonate thin film composition having a film thickness of approximately 6 μm and a rhodium metal content of 1% by weight (approximately 0.1% by volume) was prepared, and heat treated at 200°C to form a gold electrode. After forming, the conductivity (room temperature) was measured. The conductivity is 3.
5XIQ-'3cm-'.

Incidentally, the electrical conductivity of the polycarbonate thin film containing no palladium metal was I x 10-16Sai-'.

[Brief explanation of the drawing]

FIG. 1 shows the temperature change in electrical conductivity of a polycarbonate thin film composition with a palladium metal content of 1% by weight (approximately 0.1% by volume) in Example 1, and FIG. Figure 3 shows the change in electrical conductivity of the polycarbonate thin film composition by weight (approximately 0.1 volume %) with respect to the film thickness.
Figure 3 shows the temperature change in electrical conductivity of a weight percent (approximately 1 volume percent) polymethyl methacrylate thin film composition.

Claims (1)

[Scope of Claims] 1. An organic polymer thin film conductive composition having a thickness of 20 μm or less, containing metals that are mutually independent and uniformly finely dispersed. 2. The conductivity of an organic polymer thin film according to claim 1, characterized in that the organic metal complexes in the organic polymer are heat-treated to form metals that are mutually independent and uniformly finely dispersed. Composition.