JPS5915937B2 - High dielectric composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to highly dielectric compositions, and particularly to highly dielectric compositions containing cyanoethylated polyols in the polymer.

Electroluminescent and capacitor devices require materials that are moldable and have high dielectric constants.

In particular, electroluminescent devices consist of a substrate in which luminescent particles are dispersed in a suitable binder, sandwiched between two electrodes, at least one of which conducts light. In this case, the higher the dielectric constant as the binder for the luminescent particles, the brighter the luminescence can be obtained (for example,
Journal,of,Optical,Society. 0 of America, Vol. 42, p. 850 (1952), etc.

). Conventionally, as binders for electroluminescent substrates, cyanoethylated products of cellulose and cellulose derivatives, such as cyanoethylated cellulose, cyanoethylated hydroxyethylcellulose, and cyanoethylated starch, are known.

(For example, U.S. Patent Nos. 3096289 and 30936)
No. 29, 3247414, etc. ) Such a binder has a relatively low dielectric constant, and an electroluminescent screen using this binder cannot emit sufficiently bright light.Furthermore, it is brittle as a base material, making it difficult to mold the base material. accompanied by. In order to solve the above drawbacks and provide a high dielectric composition, US Pat. No. 3,161,539 discloses
It is stated that by mixing 5 to 50% of cyanoethylated sucrose into 05 cyanoethylated cellulose or the like, a very flexible film with good moldability can be obtained. However, in the above composition, there is hardly any improvement in dielectric constant, and it cannot be said that i0 is practically satisfactory. That is, electroluminescent substrates with higher luminous efficiency have recently been particularly desired, which requires binders for substrates with even higher dielectric constants.
On the other hand, there is a demand for low-cost, highly dielectric binders. The first object of the present invention is to provide a highly dielectric composition.

The second object is to provide a high dielectric composition with low dielectric loss.

The third objective is to provide a flexible, highly dielectric composition that is easy to mold.
The fourth objective is to provide a transparent high dielectric constant composition. Fifth, it is an object of the present invention to provide a high dielectric composition which is excellent as a binder for electroluminescent substrates. Sixthly, the present invention provides an excellent highly dielectric composition for use in capacitors. Seventhly, it is necessary to provide a high dielectric constant binder that is low cost and has good moldability. As a result of extensive research, the present inventors have found that the objects of the present invention can be achieved with a composition comprising a compatible polymer containing at least 5% by weight of at least one type of cyanoethylated polyol. Ta.

The cyanoethylated polyols according to the present invention have 2 carbon atoms.
~11, is a cyanoethylated product of the hydroxyl group of polyols having a molecular weight of 235 or less, preferably 185 or less, and at least 50 (fl) or more of the hydroxyl group of the polyol,
Preferably, 80% or more is cyanoethylated, and the molecule has at least two or more cyanoethyl groups. Such cyanoethylated polyols are in the form of liquid or wax, and the composition of the present invention using them has the advantage of being easy to mold.

The cyanoethylated polyols according to the present invention can be obtained by cyanoethylating the above polyols by a known method.

Typical polyols from which cyanoethylated polyols useful for the present invention can be obtained are as follows (1) to
This is expressed in section (3). Here n is 2 to 11
represents an integer.

However, when n is 2 to 5, one molecule may be dehydrated between two molecules to form an ether bond. Moreover, when n is 4 to 11, one molecule may be dehydrated within the molecule to form a 5- or 6-membered cyclic ether. Here, R is -CH2OH, -CH
(0H). CH2OHl hydrogen atom, -CH3, -C2H
5, -0H, -0CH3, -0C2H5.

(3) Monosaccharides, monomethylated monosaccharides, or monoethylated monosaccharides. Preferred cyanoethylated polyols of the present invention are those having three or more cyanoethyl groups in the molecule, and more preferred are chain polyols in which four or more hydroxyl groups are cyanoethylated (for example, the general formula (1 )
Alternatively, it can be obtained by selecting an appropriate polyol from among the polyols included in () and cyanoethylating it by a known method.

) or cyclic polyols in which three or more hydroxyl groups are cyanoethylated (for example, cyclic ethers from general formula (1), monosaccharides, monomethyl monosaccharides, or monomethylated monosaccharides can be obtained by cyanoethylation. )
It is. Specific compounds of cyanoethylated polyols particularly useful in the invention are shown below: cyanoethylated sorbitol, cyanoethylated diglycerin, cyanoethylated pentaerythritol, cyanoethylated trimethylolpropane, cyanoethylated inositol, cyanoethylated zorbitan, cyanoethylated methyl glycose. It is a kind.

It is preferable for the composition of the present invention that the cyanoethylated polyols of the present invention contain as many cyanoethyl groups as possible in the molecule, have a relatively low molecular weight, and be in the form of a liquid or wax.

Regarding the cyanoethylated polyols used in the present invention, for example, cyanoethylated sorbitol and cyanoethylated diglycerin can be used in a journal. of. It is described in Gas Chromatography, 196330 (1963). The cyanoethylated polyol used in the present invention can be obtained by combining polyol with acrylonitrile in the presence of an alkali according to the synthesis method described in U.S. Pat. No. 3,161,539, U.S. Pat. It can be obtained by reaction.

A synthesis example is shown below. Synthesis example. For the number of moles of polyol per hydroxyl group in 1 mole of polyol,
About 0.2 mol of sodium hydroxide is added as a 10% aqueous solution to obtain an alkaline solution, and about 1.5 parts of acrylonitrile is added dropwise over 30 minutes to 1 hour while stirring. At this time,
The reaction temperature is always kept at about 35-45°C. After further stirring at the same temperature for about 2 hours, the resulting cyanoethylated polyol is extracted with an appropriate amount of an organic solvent (chloroform, ethyl acetate, etc.), which is then washed with water, 1N acetic acid (or 1N hydrochloric acid), and water, After drying over anhydrous magnesium sulfate, chloroform was distilled off under reduced pressure, and further heated at 100°C for 0.25vL.
Keep at H9 for 3-5 hours to completely remove volatiles. The cyanoethylated polyol synthesized by this method is
According to the results of elemental analysis of nitrogen, the cyanoethylation rate is 80%.
As described above, the liquid was transparent with almost no coloration, and most of the liquid was viscous. The polymers according to the present invention are polymers that are compatible with cyanoethylated polyols, such as celluloses, polyvinyl alcohols, dextrins, starches, polyacrylic esters, polymethacrylic esters, polyfumaric acid esters,
Acrylate-styrene copolymer, methacrylate-
Styrene copolymers, fumarate-styrene copolymers, etc., such as triacetylcellulose, diacetylcellulose, methylcellulose, ethylcellulose, cyanoethylated cellulose and cyanoethylated starch described in U.S. Pat. No. 3,247,414, LakO
krasOch. mater. IkaPrlmen. l
Cyanoethylated methylcellulose, cyanoethylated hydroxyethylcellulose, polyvinyl alcohol, cyanoethylated polyvinyl alcohol, cyanoethylated cyclotextrin, cyanoethylated hydroxypropyl starch, cyanoethylated dextrin, polymethyl acrylate, polybutyl described in Vol. 968, No. 4, pages 13 to 15 acrylate, polycyanoethyl acrylate,
Examples include polymethyl methacrylate, polybutyl methacrylate, polycyanoethyl methacrylate, polycyanoethyl fumarate, cyanoethyl acrylate-styrene copolymer, cyanoethyl methacrylate-styrene copolymer, cyanoethyl fumarate-styrene copolymer, etc. can. Particularly preferred polymers of the present invention are polymers having a cyanoethyl group moiety in the molecule (
Cyanoethylated hydroxyl group or cyanoethyl esterified carboxyl group in the molecule), such as cyanoethylated cellulose, cyanoethylated starch, cyanoethylated methylcellulose, cyanoethylated hydroxyethylcellulose, cyanoethylated polyvinyl alcohol, cyanoethylated cyclodextrin, Cyanoethylated hydroxypropyl starch, cyanoethylated dextrin, polycyanoethyl acrylate, polycyanoethyl methacrylate, polycyanoethyl fumarate, cyanoethyl acrylate-styrene copolymer, cyanoethyl methacrylate-styrene copolymer,
These include cyanoethyl fumarate-styrene copolymer.
The highly dielectric composition of the present invention is composed of a compatible polymer containing at least 5% by weight of at least one cyanoethylated polyol, and is uniformly dispersed without any lumps or cloudiness. When this polymer does not have a cyanoethyl group moiety in its molecule, a low-cost, highly dielectric composition can be obtained, which is also effective.

That is, polymers that do not have a cyanoethyl group in the molecule (e.g. cellulose, polyvinyl alcohol, dextrins, starches, polyacrylic esters, polymethacrylic esters, polycyanofumaric esters, acrylates) - styrene copolymer,
Although methacrylate-styrene copolymers, fumarate copolymers, etc.) are also effective, it is particularly preferable to use them in combination with at least one cyanoethylated polyol as described above because a composition with a high dielectric constant can be obtained. is a polymer having a cyanoethyl group in its molecule (the type of polymer is the same as above). Moreover, although one type of polymer may be used in the present invention, two or more types may be mixed and used. A preferable polymer having a cyanoethyl group according to the present invention is one in which most of the hydroxyl groups or carboxyl groups of the polymer are cyanoethylated.

The cyanoethylated polymer used in the present invention is PrOc
．． XIthIntern-GOngr-Pureand
Appl. Chem. 5, 123-131 (1947)
, Italian Patent No. 559402, British Patent No. 808
No. 290, No. 872542, LakOkrasOch
-Mater・IkPrlmen. l968(14),
13-15, U.S. Patent No. 3,438,913, Special Publication No. 1973
-20513, Dutch patent application (published) 65055
No. 57, Special Publication No. 45-20513, U.S. Patent No. 309
No. 6289, No. 3093629, Special Publication No. 47-189
It is obtained by reacting a hydroxyl group-containing polymer described in No. 86, US Pat. No. 3,689,361, etc. with acrylonitrile in the presence of an alkali. The highly dielectric composition of the present invention is composed of a compatible polymer containing 5% by weight or more of at least one of the above-mentioned cyanoethylated polyols, and preferably, the above-mentioned compatible polymer is A polymer having a cyanoethyl group in the molecule is preferred because a composition with a particularly high dielectric constant can be obtained. More preferably,
25 to 7 at least one type of cyanoethylated polyols
It consists of a polymer containing 5% by weight. Such a high dielectric composition had a dielectric constant of 25 or more and a dielectric loss of 0.1 or less. The highly dielectric composition of the present invention is a highly dielectric binder known in the art (for example, as described in U.S. Pat. No. 3,161,539, U.S. Pat. No. 3,096,289, U.S. Pat.

) has a considerably higher dielectric constant value (at least 25
(above) are highly desirable as electroluminescent substrates. The high dielectric composition of the present invention containing a liquid cyanoethylated polyol is as follows:
It has features such as being extremely flexible, easy to mold (for example, film molding, etc.), and having low dielectric loss. In particular, it is superior to the cyanoethylated cellulose containing 5 to 50% of cyanoethylated shakerose as described in US Pat. No. 3,161,539, especially in terms of relative dielectric constant. For example, when applied to an electroluminescent substrate, a very bright electroluminescent device can be obtained.
〉Furthermore, the present invention has surprisingly revealed that the high dielectric constant composition of the present invention has an even higher dielectric constant than the individual components of the cyanoethylated polyol and the polymer. The dielectric constant can be obtained. (This is particularly noticeable in the case of cyanoethylated polymer 5.) That is, the combination effect of increasing the dielectric constant of each component of the composition was obtained, which is a surprising effect that could not have been predicted in the past. In practice, the composition of the present invention is used as a binder in an electroluminescent device, and is applied to electroluminescent particles (e.g., ZnS, ZnSc, CdS, PdS or CdS-Z).
nS, etc., and if these are doped with Cu as an activator, they may also contain group elements such as Cl, Mn, etc., and group elements such as Al as co-activators). When used as a luminescent substrate, it produced significantly brighter light than conventional X-ray fluorescent screens. Electroluminescent devices using the composition of the present invention include, for example, an X-ray PC/EL board, an
There are many things, such as intensifying screens, camera exposure meters, photodetector elements, photoelectric conversion elements, and solid-state video plates.

Among these, for example, in an X-ray PC/EL board, the high dielectric composition of the present invention can be used as a binder for the EL layer. Regarding electroluminescent devices and their substrates, see, for example, "Polar Light X-Ray.46.l
4, pp. 16-32 (1959)" and "Image Technology February 1972 issue, pp. 62-74." Example: A cyanoethylated polyol and a compatible polymer are dissolved and mixed using a solvent (for example, acetonitrile, nitromethane, methylene chloride, acetone, etc.), and the mixture is cast onto a glass plate to form a film and the solvent is completely removed. An example of preparing a sample into a uniform thin film is shown below.

Sample 1: Cyanoethylated cellulose (cyanoethylation rate 840!) 2.5f! and cyanoethylated pentaerythritol (cyanoacetylation rate 87%) 2.59 were dissolved in 107 rL1 of acetone, and after casting on a glass plate, the acetone was gradually evaporated at room temperature, and further heated at 80°C and 10-2
The film was kept at mmH9 for 1 hour to completely remove acetone and form a film.

Sample 2: Cyanoethylated cellulose (cyanoethylation rate 84%) 2.59 and cyanoethylated methylglucose (cyanoethylation rate 92%) 2.59 in nitromethane 1
Melt and mix at 0ml, cast onto a glass plate, gradually evaporate nitromethane at room temperature, and further heat at 80°C and 10-2mm.
It was kept at H9 for 1 hour and made into a film.

Sample 3: Cyanoethylated hydroxyethyl cellulose (cyanoethylation rate 79%) 2.59 and cyanoethylated trimethylolpropane (cyanoethylation rate 95%) 2
．． 59 was dissolved in 10 WLI of acetonitrile, and after casting on a glass plate, the acetonical was gradually evaporated at room temperature, and the mixture was further kept at 80° C. and 10 −2 ml Hf1 for 1 hour to form a film.

The films of Samples 1 to 3 were all uniform without any bumps or cloudiness, and the cyanoethylated polyol and the polymer were well compatible.

Each sample of thin film formed as described above is 1K.
The dielectric constant and dielectric loss were measured by applying an alternating current electric field of Hz.

Incidentally, as comparative data, data described in US Pat. No. 3,161,539 is cited.

From the above results, in the high dielectric composition of the present invention,
It has been found that the composition of the present invention, which is a combination of each component, has a synergistic effect in that it has a higher dielectric constant than the dielectric constant of each component.

As can be seen from this table, the high dielectric constant composition of the present invention had a higher dielectric constant than the cyanoethylated sucrose-containing polymer described in US Pat. No. 3,161,539.

Note that when the above composition of the present invention is used as a luminescent binder for a capacitor or an electroluminescent device,
The high dielectric constant of the luminescent substrate not only significantly improves luminescence, but also overcomes the brittleness of the film and provides flexibility.

1. A highly dielectric composition having a dielectric constant of 25 or more and a dielectric loss of 0.1 or less, which is flexible and has good moldability.

). ．． The highly dielectric composition according to item 1, which is a cyanoethylated polyol consisting of polyols substituted with three or more cyanoethyl groups.

3. In item 1, a polymeric polyol characterized by being a cyanoethylated polyol consisting of a linear polyol substituted with 4 or more cyanoethyl groups or a cyclic polyol substituted with 3 or more cyanoethyl groups. Dielectric composition.

4. In item 1, the cyanoethylated polyols are
A highly dielectric composition comprising at least one selected from the group consisting of cyanoethylated sorbitol, cyanoethylated diglycerin, cyanoethylated inositol, cyanoethylated zorbitan, and cyanoethylated methyl glycose.

5. In item 1, the polymer having a cyanoethyl group moiety is cyanoethylated cellulose, cyanoethylated starch, cyanoethylated methylcellulose, cyanoethylated hydroxyethylcellulose, cyanoethylated polyvinyl alcohol, cyanoethylated cyclodextrin, cyanoethylated hydroxypropyl starch, cyanoethylated dextrin, At least one selected from the group of polycyanoethyl acrylate, polycyanoethyl methacrylate, polycyanoethyl fumarate, cyanoethyl acrylate-styrene copolymer, cyanoethyl methacrylate-styrene copolymer, and cyanoethyl fumarate-styrene copolymer. High dielectric composition in some cases.

3. In item 1, a highly dielectric composition comprising a compatible polymer containing 25 to 75% by weight of at least one cyanoethylated polyol.

Claims (1)

[Claims] 1. At least one liquid or waxy cyanoethylated polyol in which 50% or more of the hydroxyl groups of a polyol having 2 to 11 carbon atoms and a molecular weight of 235 or less are cyanoethylated and has at least two or more cyanoethyl groups in the molecule, and this. A highly dielectric composition comprising a compatible cyanoethylated polymer and containing the cyanoethylated polyol in an amount of 5% by weight or more.