JPS60199063A - Highly dielectric composition - Google Patents

Abstract

PURPOSE:To provide a composition of both large dielectric constant and high breakdown voltage, with outstanding shaping capability, constituted by finely dispersed metal-contg. polymer obtained by blending a solvent-soluble organometallic complex and polymer followed by heating. CONSTITUTION:An organometallic complex of formula (m is 1-4; n is 2-12; metal M is either A of the IV, V, VI or VII group or B of the VIII or I group, pref. titanium, zirconium; ligand L is tertiary phosphine, tertiary phosphite, etc., its boiling point being pref. <=400 deg.C) is dissolved in a solvent (e.g. xylene, ethyl acetate) to prepare a solution. This solution and a polymer of any form (e.g. polymethyl methacrylate, pref. with high breakdown voltage and low tandelta) are homogeneously mixed. The solvent is then removed from the resulting system followed by heating, normally at 100-250 deg.C for several-several tenth minutes, thus obtaining the objective composition, i.e. a polymeric one with metal finely dispersed in it; said metal having deposited by pyrolysis of the organometallic complex. The metal content is the final composition is pref. 2-70(esp. 5- 50)vol%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a highly dielectric composition comprising a polymer containing finely dispersed metal obtained by heating a polymer containing an organometallic complex.

The present inventors previously disclosed in Japanese Patent Application No. 58-82170 that by incorporating an organometallic complex into a polymer and heating the polymer to a temperature at which the thermal decomposition of the organometallic complex sufficiently proceeds. It has been found that a polymer composition in which metal is finely dispersed in the polymer can be obtained.

The dispersed metal is extremely fine and has an average particle size of 20 to 200 mμ, although it varies depending on the metal type, polymer type, thermal decomposition conditions, etc., and the metal particles precipitated in the polymer have independent structures. have.

Although the composition has various properties depending on its structure, it was discovered that it has excellent insulating properties and a high dielectric constant under an electric field, leading to the completion of the present invention.

The present invention will be explained in detail below.

It is known that when metal particles are dispersed in a polymer and an electric field is applied, interfacial polarization occurs at the interface between the metal particles and the polymer, so that such a composition has a high dielectric constant.

The strength of the interfacial polarization that occurs depends on the eccentricity when the metal particles are assumed to be spheroidal, the electrical conductivity and surface area of the metal particles, the volume fraction of the metal particles in the polymer, etc.

Therefore, in order to obtain a metal particle-dispersed polymer composition with a high dielectric constant, it is sufficient to disperse a high content of fine metal particles that have a large eccentricity, that is, are elongated in the direction of the electric field, and have high conductivity. become.

Generally, there are several methods for dispersing metal particles obtained by mechanical pulverization, cutting, pneumatic pulverization, electrolysis, melt spraying, etc. into a polymer. For example, a method in which a polymer is melted under heating using a continuous kneader equipped with rolls, a Banbury mixer, or a screw and metal particles are mechanically dispersed, and a method in which a polymer is dissolved in an appropriate solvent and metal particles are dispersed. These methods are industrially useful.

However, in these methods, when attempting to disperse metal particles in a polymer at a high content, there is a limit to the amount that can be contained because contact between metal particles naturally occurs.

If the metal particles are poorly dispersed, the metal particles will partially contact each other and the breakdown voltage of the metal particle-dispersed polymer composition will decrease, making it unusable for practical use.

Therefore, although it has been known theoretically that a useful dielectric material can be obtained by dispersing finer metal particles in a polymer at a high content, there are problems with the method of realizing this, especially the dispersion method. Because of this, it was not put into practical use.

However, in the metal particle-dispersed polymer composition produced by the method of the present invention, no matter how high the content of metal particles is, the particles do not come into contact with each other, and therefore the breakdown voltage of the composition does not decrease. .

This is because, in the method of the present invention, a solvent-soluble organometallic complex and a polymer are mixed and then heated to a temperature at which thermal decomposition of the organometallic complex sufficiently proceeds in the presence of a solvent or after removal of the solvent. This is to decompose the organometallic complex and precipitate the metal.

That is, in the method according to the present invention, since the metal is precipitated from inside the polymer, the surrounding polymer acts as a partition wall and the metal particles do not come into contact with each other.

The dielectric composition obtained by the present invention is characterized by its high dielectric constant, high breakdown voltage, and excellent formability.

Generally, dielectric compositions are processed into various shapes, such as film, plate, chip, rod, etc., depending on the desired use. In this case, workability is a practically important factor along with dielectric constant, but since the composition according to the present invention has extremely finely dispersed metal particles, the workability of the composition may be impaired even at a high content. Not industrially used molding machines,
For example, compression molding machines, injection molding machines, extrusion molding machines, roll molding machines, etc. can all be used.

The method for producing the metal particle-dispersed polymer composition used in the present invention is as follows.

The organometallic complexes used in the present invention are selected from those that exhibit solubility in solvents and release metals by heating, and have the general formula M, L, l (m is 1 to 4, n is 2 to 12). (integer).

Metal M is the periodic table! Va, Vs, VIA, ■1,
■, ■, group metals, titanium, zirconium, vanadium, chromium, molybdenum, tungsten, manganese, rhenium, iron, cobalt, nickel, ruthenium,
Osmium, rhodium, palladium, iridium, platinum, copper, silver, gold, etc. are preferred.

Examples of the ligand include tertiary phosphine, tertiary phosphite, carbon oxide, linear or cyclic olefin, conjugated olefin, aryl compound, organic cyano compound, organic isonitrile compound, organic mercapto compound, or alkyl group. It can be selected from a combination of one or more of compounds having a vinyl group, allyl group, ethyridine group, or acyl group, and may also be an atom such as halogen, oxygen, hydrogen, or nitrogen.

The boiling point of the ligand is 400°C in relation to the thermal decomposition of organometallic complexes.
The following are particularly preferred.

Polymers used in the invention include - polyacecool, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polysulfone, to name a few.
Heat resistance of thermoplastic resins such as polyether sulfone, polyarylate, polyphenylene sulfide, polyethylene, polypropylene, polymethyl methacrylate, ABS resin, diallyl phthalate resin, unsaturated polyester resin, phenol resin, amino resin, epoxy resin, polyimide resin, etc. Although there are curable resins and rubber-like resins such as silicone resins, polyurethane resins, and styrene-butadiene rubbers, it is desirable to select a polymer with high breakdown voltage and low dielectric loss tangent depending on the purpose of use.

These polymers may be used as they are in the form of powder, particles, blocks, etc., or may be used as a solution or dispersion in which the polymer is dissolved in a solvent.

The polymer composition containing finely dispersed metal according to the present invention can be obtained by heating the polymer composition containing the above-described organometallic complex.

The heating temperature is selected to be a temperature at which the metal precipitation reaction proceeds by thermal decomposition of the organometallic complex. Therefore, it is not necessarily necessary to adopt the thermal decomposition temperature of the organometallic complex. That is, the temperature is generally 50 to 400°C, usually 100 to 250°C, but a temperature at which thermal decomposition of the polymer does not proceed is selected.

A heating time of several minutes to several tens of minutes is sufficient at the above temperature.

A polymer composition containing an organometallic complex can be obtained by mixing a polymer in any form and an organometallic complex solution dissolved in a solvent.

To obtain a uniform composition, uniform mixing is required. For example, by uniformly mixing a powdered polymer and an organometallic complex solution using a mixer and removing the solvent, or by uniformly mixing a polymer solution and an organometallic complex solution and removing the solvent, etc. and organometallic complexes can be easily obtained.

The method of producing a polymer composition containing an organometallic complex by mixing a polymer in any form and an organometallic complex solution dissolved in a solvent as in the present invention is more efficient than the case where an organometallic complex solution is not used. Both are mixed evenly. Therefore, a polymer containing a finely dispersed metal can be obtained.

It is usually better to carry out the above mixing at a temperature at which thermal decomposition of the organic gold Klf lit body does not proceed much. Other additives such as stabilizers, plasticizers, colorants, etc. can also be optionally added depending on the purpose of use.

The type of solvent used for the polymer or organometallic complex is not particularly limited, and a single solvent or a mixture of two or more solvents may be used.

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, acetonitrile, dimethylformamide, dimethyl sulfoxide and the like.

In this way, a polymer composition containing a finely dispersed metal can be obtained by heating a polymer composition containing an organometallic complex to a temperature at which the thermal decomposition of the complex sufficiently proceeds, and can be used in any desired manner depending on the application. It is shaped into a shape.

The metal content in the polymer composition containing finely dispersed metal is preferably from 2% by volume to 70% by volume, particularly preferably from 5% by volume to 50% by volume.

If it is less than 2% by volume, the dielectric constant is small, and if it is more than 70% by volume, the dielectric constant is sufficient, but the formability becomes poor.

EXAMPLES The present invention will be explained in detail below with reference to Examples, but the present invention is not limited thereto.

Example 1 Polymethyl methacrylate (polymerization degree 7000-7500
) was added with ethyl acetate to make a 25% by weight ethyl acetate solution, and to 100g of this solution was di-μ with a metal content of 54% by weight.
After 2.44 g of mchloro-bis(η-2-methylallyl)dipalladium(n) complex was dissolved to form a homogeneous solution, ethyl acetate was removed to prepare polymethyl methacrylate containing the complex.

This was preheated using a hydraulic molding machine at 190°C for 5 minutes without pressure, and then molded at 30 kg/c+J for 2 minutes.

Further, cooling pressing was performed for 5 minutes at 30 kg/- to obtain a black plate-like body with a thickness of 31 mm.

Di-μm chloro-bis(η-2-methylallyl)dipalladium(II) contained in polymethyl methacrylate
) The complex completely decomposed during preheating to precipitate palladium metal, the content of which was 5% by volume.

Table 1 shows the measurement results of the dielectric properties (ε: dielectric constant, tan δ: dielectric loss tangent), volume resistivity, and dielectric breakdown voltage of the obtained molded body.

Example 2 Polymethyl methacrylate (polymerization degree 7000-7500
) to make a 5% by weight xylene solution,
To 100 g of this solution, 14.5 g of octacarbonyl nicobalt (0) complex having a metal content of 34.5% by weight was put into a reactor equipped with a reflux condenser to form a homogeneous solution, which was then heated to reflux with stirring.

As the cobalt metal decomposed, the reaction solution turned black due to the precipitated cobalt metal, and carbon monoxide gas was observed to be generated. - When the generation of carbon oxide gas was finished, xylene was removed to obtain black cobalt-dispersed polymethyl methacrylate.

The obtained cobalt-dispersed polymethyl methacrylate was preheated at 190°C for 3 minutes without pressure using a hydraulic molding machine, then molded for 2 minutes at 30 kg/aJ, and then further molded at 30 kg/cJ.
A cooling press was performed for 5 minutes to obtain a black plate with a thickness of 3 nm.

The cobalt content of this molded body was 12% by volume.

Table 1 shows the measurement results of the dielectric properties (ε: dielectric constant, tan δ: dielectric loss tangent), volume resistivity, and dielectric breakdown voltage of the obtained molded body.

Example 3 ° In the same manner as in Example 2, 100 g of a 5% by weight xylene solution of polymethyl methacrylate (degree of polymerization 7000 to 7500) and octacarbonyl nicobalt (0) complex 46
．． A plate-shaped molded body of cobalt-dispersed polymethyl methacrylate having a cobalt content of 30% by volume was obtained from 1 g.

Table 1 shows the results of measuring the dielectric properties (ε: dielectric constant, tan δ: dielectric loss tangent), volume resistivity, and dielectric breakdown voltage of the obtained molded body.

Claims (1)

[Claims] A highly dielectric composition comprising a polymer containing finely dispersed metal obtained by heating a polymer containing an organometallic complex.