JPH03129604A - Macromolecular dielectric - Google Patents

Abstract

PURPOSE:To provide a macromolecular dielectric of a small size, a high capacity, a small dielectric loss, and an excellent frequency characteristic by using a polymer composed of an electron-conjugate, conductive straight chain surrounded by dielectric side chains. CONSTITUTION:A dielectric is constituted with a polymer having a long electron conjugate straight chain with a side chain of a carbon number of one or more and not electron-conjugating with the straight chain connected to almost all the straight chain atoms capable connecting to the side chain. Since this constitution provides a long electron conjugate straight chain by sigma electron conjugate or pi electron conjugate, electric field causes electrons to polarize widely in the direction of the straight chain of the macromolecule. This macromolecule, while causing great electron movement within the molecule, has a very high energy barrier between molecules. Side chains of carbon number of one or more contribute to the stability and make a stable substance. The sigma electron conjugate straight chain, when the macromolecule is arranged in the electric field direction, increases the movement of electrons within the molecule in the electric field direction and provides excellent functions such as providing large dielectric constant, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a novel polymeric dielectric material having a long electronically conjugated main chain used primarily in capacitors.

Conventional technology Various types of dielectric materials are used, including ceramics and polymers.

Polymers in which conductive particles such as carbon black and charge transfer complexes are dispersed have also been proposed.

Problems to be Solved by the Invention Conventional polymer-based products all have a small dielectric constant of less than IO, which limits the ability to make them compact and large in capacity.On the other hand, products using conductive particles dispersed in polymers Although the dielectric constant cannot be dispersed in an orderly and precise manner, the dielectric loss increases, making it impractical for practical use. The purpose of the present invention is to provide a polymeric dielectric material with high capacity, low dielectric loss, and excellent frequency characteristics. The polymer in the present invention can be formed using a polymer in which almost all the main chain atoms that can be bonded have a side chain having one or more carbon atoms that is not electronically conjugated with the main chain. The polymer dielectric material at the center has the following five major differences.

(a) It has a long electron-conjugated main chain due to σ-electron conjugation or π-electron conjugation. Although the electrons are largely polarized in the direction of the main chain of the polymer due to the electric field, (b) The side chain has 1 carbon atoms and is not electron-conjugated with the main chain. Consisting of the above side chains, the side chains themselves localize electrons and are insulating, while also widening the intermolecular spacing.In other words, the polymer of the present invention has a large intramolecular size. There is an extremely high energy barrier between molecules that cause electron transfer. Therefore, σ-electron conjugated polymers with Si and Ge as main chains are excellent dielectric materials. Becomes a stable material.

(d) σ-electron-conjugated main chain (y) Unlike a carbon-carbon double bond, it is a single bond and has excellent flexibility, and the electronic polarization behavior is greatly affected by the conformation of the main chain.Therefore, these polymers When oriented in the direction of the electric field, the intramolecular movement of electrons in the direction of the electric field becomes extremely large, giving an even larger dielectric constant.

(e) In the case of a polymer having a side chain with one or more carbon atoms substituted with a polar group that causes large electronic polarization, this system has an electronically conjugated main chain portion that facilitates electron transfer by an electric field and a high electronic polarizability. It is composed of insulated side chain parts and forms an excellent polymeric dielectric.

Example Invention Q A polymer having a long conjugated electronic main chain is used in which almost all the main chain atoms to which side chains can be bonded are bound to side chains having one or more carbon atoms that are not electronically conjugated to the main chain. The polymer dielectric is made of the following specific materials.

Long conjugated electron main chain f: Consists of a σ electron conjugated lukewarm main chain having LSi or Ge as the main chain, or a π electron conjugated main chain having a carbon-carbon double bond as the main chain.

Examples of π-electron conjugated main chains include polyacetylene, polythiophene, polypyrono-boreacene, polyphenylene sulfide, and polyaniline, and the electron mobility within these main chains is known to have high conductivity comparable to that of metal conductors. A side chain with one or more carbon atoms that has no electronic conjugation with the main chain on ζ is bonded to almost all the main chain atoms that can bond side chains of the main chain.

In addition, polymers with σ-electron conjugated polymers i&si or Ge as main chains, and in which side chains consisting of insulating carbon chains having 1 or more carbon atoms are bonded to almost all of the main chains that can be bonded to side chains, i.e., polysilane or Formed from polygermane.

At least one member selected from the group consisting of alkyl Ay, phenyl, alkylphenyl, alkoxyphenyl, cycloalkyl, and aralkyl is used in the side chain of the polymer of the present invention.

The shape and length of these side chain groups have a large effect on the mechanical properties of the polymer, such as its film formability and flexibility. However, they are all characterized by their side chains not being electronically conjugated with the main chain.
These side chains exhibit insulating properties. Specifically, alkino-k having 1 to 8 carbon atoms
Suitable examples include alkylphenyl, alkoxyphenyl, cycloalkyl, and aralkyl having alkyl thereof.

Side chain force attraction of the polymer of the present invention When the polymer is composed of a carbon chain having 1 or more carbon atoms substituted with a polar group having large electronic polarization, the dielectric constant of the side chain becomes large and the polymer dielectric becomes even more excellent. Become.

As a polar group used for this purpose (cyano group amino salt
These include a nitro group, a t-butyl group, an amide group, a hydroxyl group, a sulfonium group, an ester group, a halogen, and a phenyl group substituted with at least one of these groups, and polarization by these groups greatly contributes to the dielectric constant.

Side chains having one or more carbon atoms substituted with a polar group having large electronic polarization include aralkyl groups (such as benzyl groups) and alkyl groups substituted with the above polar groups.

Among these, those substituted with amide groups, hydroxyl groups, nitro groups, amino groups, etc. create films with strong mechanical properties due to strong intermolecular forces due to intermolecular hydrogen bonds.

Furthermore, polarization can be further increased by using a polar substituent that combines an electron-donating group such as an aminomi-t-butyl group, a hydroxyl group, and an electron-accepting group such as an ester group, a halogen group, a cyanide group, or a nitro group. An example of this is poly(nitrophenyl)(dimethylanilino))acetylene, which is also a main chain electronically conjugated polymer having a side chain of one or more carbon atoms that is not electronically conjugated with the main chain of the present invention. Not only does it have excellent physical stability, but its molecular structure approaches an amorphous one, making it highly soluble in solvents, making it useful for heavy particle applications.

Furthermore, it is also possible to easily make a composite dielectric by using the polymeric dielectric of the present invention as a matrix material and filling it with various dielectric particles.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Example 1 IOμm thick polymer dielectric and 5μm thick AI foil
A laminated capacitor as shown in FIG. 1 was formed by stacking layers, that is, a 5 μm thick A1 foil electrode (A) 1 was placed on one side of the polymer dielectric 3 of the present invention, and a 5 μff+ thick AI foil electrode was placed on the other side.
The foil electrodes (b) 2 were stacked four times to form a multilayer capacitor, and the foil electrodes (b) 2 were laminated as polymer dielectrics (5 types of polysilane, polysilane, etc. shown in (a) to (e) in Table 1). Gelman was used, and polyester was used in the comparative example.The capacitance of the capacitor is shown in the table.

Dielectrics (c) and (d) are materials that have polar groups in their side chains, and (e) is a material that has intermolecular bonds due to hydrogen bonds between amide groups.

Dielectric material (c)i;L A dielectric material was prepared by kneading poly(methyl(chlorobenzyl)silylene) and poly(methyl(t-butylphenyl)silylene) in a ratio of 1:1, and it is clear from Table 9. As shown above, the capacitance of the present invention can be approximately 20 times or more higher than that of the conventional example.

This is an effect of the present invention in that the Δ dielectric constant increases because the main chain having conductivity in the σ electron conjugated system is surrounded by side chains having dielectric properties.

In particular, in dielectrics (c) and (d), a high dielectric constant can be achieved because a polar group is arranged in a side chain that has dielectric properties.
.

In addition, the polymer dielectrics of the present invention (a) to (e) have film formability, flexibility, and chemical stability similar to those of the comparative examples. .

Example 2 AI electrodes are deposited on a polymer dielectric with a thickness of to, am, and stacked to form a multilayer capacitor. 3 shown in (f) to (h) in Table 1
Table 1 shows the capacitance of a capacitor using a type of π-electron conjugated polymer (using polyester as a comparative example).

As is clear from the table, the dielectric of the present invention can achieve a capacitance 20 times or more compared to the conventional example.

This is due to the effect of the present invention of increasing the dielectric constant, which is a π-electron conjugated system in which the conductive main chain is surrounded by side chains having dielectric properties. The polymer dielectric of the present invention (comparative example) had film formability, flexibility, and chemical stability similar to that of the comparative example. have
The present invention provides an excellent dielectric material which is a polymer formed by bonding side chains having one or more carbon atoms which are not electronically conjugated with the main chain to almost all of the main chain atoms to which side chains can be bonded.

These polymers have excellent mechanical properties such as film-forming properties and flexibility, as well as excellent thermal stability.They can be widely used for applications in electronic materials, and have great industrial value. Even if it becomes

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional concept showing one embodiment of a capacitor according to the present invention. 1... Electrode (A), 2... Electrode (B), 3...
polymer dielectric

Claims (7)

[Claims] (1) A polymer made using a polymer that has a long conjugated electron main chain and has a side chain of 1 or more carbon atoms that does not undergo electron conjugation with the main chain bonded to almost all the main chain atoms that can bond side chains. Molecular dielectric. (2) The polymeric dielectric material according to claim 1, wherein the long conjugated electron main chain is a σ electron conjugated main chain having Si or Ge as the main chain. (3) The polymeric dielectric material according to claim 1, wherein the long conjugated electron main chain is a π-electron conjugated main chain mainly consisting of carbon-carbon double bonds. (4) Claim 3 wherein the π-electron conjugated main chain is one selected from polyacetylene, polythiophene, polypyrrole, polyacene, polyphenylene sulfide, and polyaniline.
The polymer dielectric described. (5) The polymeric dielectric material according to claim 1, wherein the side chain comprises at least one selected from alkyl, phenyl, alkylphenyl, alkoxyphenyl, cycloalkyl, and aralkyl. (6) The polymeric dielectric material according to claim 1, wherein the side chain consists of a group having one or more carbon atoms and substituted with a polar group that causes large electronic polarization. (7) The polar group is a cyano group, an amino group, a nitro group, a t-
7. The polymeric dielectric according to claim 6, which is at least one selected from the group consisting of a butyl group, a sulfonium group, an amide group, a hydroxyl group, an ester group, a halogen, and a phenyl group substituted with at least one functional group among these. body.