JPH083459A - Fine high-permittivity organic polymer particle, its production, and high-permittivity organic polymer material - Google Patents

Abstract

PURPOSE:To obtain fine high-permittivity org. polymer particles by subjecting a cyanoethyl compd. to soln. polymn. in a polymer soln. to form fine polymer particles having a specified average particle size and permittivity. CONSTITUTION:Fine high-permittivity org. polymer particles having an average particle size of 0.1-10mum and a permittivity of 10-50 are obtd. by dissolving a matrix polymer (e.g. polyvinyl methyl ether) in a solvent (e.g. ethanol), adding to the soln. a cyanoethyl compd. selected from among cyanoethylacrylamide, cyanoethylmethylolacrylamide, cyanoethyl hydroxyacrylate, etc., a cross-linker, a polymn. initiator, etc., stirring the soln. under an N2 flow at about 40-80 deg.C for about 1-20hr, washing the resulting polymer particles with ethanol, etc., and centrifuging and vacuum-drying the particles. The high-permittivity particles are dispersed in a concn. of 5-90wt.% in an org. material (e.g. PS or a polycarbonate) to give a high-permittivity org. polymer material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high dielectric constant organic polymer fine particle, a method for producing the same, and a high dielectric constant organic polymer material.

[0002]

2. Description of the Related Art Conventionally, as a high dielectric binder for EL, a cyanoethyl compound has been mainly used.
By the way, when an organic high dielectric substance such as a cyanoethyl compound is used as a binder for an electronic material, it must be mixed with another organic polymer material or dissolved in a solvent.

[0003]

However, conventional organic high dielectrics have high polarity, and therefore have poor compatibility with other organic materials, especially organic polymer materials. Therefore, it is difficult to increase the content of the organic high dielectric substance in the organic polymer material, so that the use of the organic high dielectric substance is limited. In addition, when inorganic high dielectric fine particles such as barium titanate and strontium titanate are dispersed in an organic polymer material, they cause aggregation and sedimentation, and cannot maintain a uniform dispersion state in the material, and the There are drawbacks that degrade performance.

The present invention has been made in view of the above circumstances, and has as its object to provide, in particular, a high dielectric constant which has good compatibility with an organic polymer material and can be easily and uniformly dispersed in the organic polymer material. An object of the present invention is to provide an organic polymer fine particle, a method for producing the same, and a high dielectric constant organic polymer material in which a high dielectric constant organic polymer is dispersed and blended.

[0005]

That is, the first aspect of the present invention is as follows.
The point is that the dielectric constant is 10 to 50 and the average particle size is 0.1 to 1
The second point is that the polymerizable cyanoethyl compound is solution-polymerized in a polymer solution, wherein the high-permittivity organic polymer fine particles are characterized by being 0 μm. A third aspect of the present invention resides in a high-dielectric-constant organic polymer material characterized in that the high-dielectric-constant organic polymer fine particles are dispersed in the organic polymer material at a ratio of 5 to 90% by weight. .

Hereinafter, the present invention will be described in detail. The high dielectric constant organic polymer fine particles of the present invention have a dielectric constant of 10 to 50,
The average particle size is 0.1 to 10 μm.
A preferred range of the dielectric constant is 20 to 50. Such high dielectric constant organic polymer fine particles can be derived, for example, from a polymerizable cyanoethyl compound.

Examples of the polymerizable cyanoethyl compound include cyanoethylacrylamide, cyanoethylmethylolacrylamide, cyanoethylhydroxyacrylate, cyanoethylhydroxymethacrylate, and cyanoethylglycidyl acrylate. Among these, a compound selected from the group of cyanoethylacrylamide, cyanoethylmethylolacrylamide, cyanoethylhydroxyacrylate or cyanoethylhydroxymethacrylate is preferred.

The high dielectric constant organic polymer fine particles of the present invention are:
It is obtained by solution-polymerizing a polymerizable cyanoethyl compound in a polymer solution. Then, another polymerizable monomer can be used in combination with the polymerizable cyanoethyl compound. Other polymerizable monomers include, for example, styrene, methyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and the like.

In the present invention, solution polymerization is performed using a polymer (matrix polymer) in a solvent as a polymerization field. As the matrix polymer, polyvinyl alcohol, its ether, polystyrene, polycarbonate and the like are preferable. As the solvent for the matrix polymer, various solvents can be used as long as the produced fine particles are not dissolved. Suitable solvents include methanol,
Examples include ethanol, hexane, dioxane, and tetrahydrofuran.

[0010] The matrix polymer in the good solvent is in a stretched state in the solution, and the matrix polymer in the poor solvent is in a state of agglomeration in a thread form. Therefore, the free volume space formed between the matrix polymers can be controlled by changing the solvent composition. The polymerizable cyanoethyl compound forms clusters of minute units in the free volume space to generate uniform fine particles, and the average particle size of the fine particles can be controlled by controlling the free volume space.

The solution polymerization is completed by stirring a mixed solution of a polymerizable monomer, a matrix polymer, a solvent, a crosslinking agent and a polymerization initiator at a temperature of 40 to 80 ° C. for 1 to 20 hours under a nitrogen stream. The obtained fine particles are washed with a solvent such as acetone, ethanol, methanol, dioxane, and tetrahydrofuran, centrifuged, and dried to obtain a product.

The high dielectric constant organic polymer fine particles of the present invention are:
It has a spherical or elliptical shape, and its particle size varies depending on conditions such as the type of the matrix polymer and the solvent, the amount of the crosslinking agent, and the temperature. Generally, in a good solvent for the matrix polymer, the main chain of the matrix polymer is soft, so that when the amount of the crosslinking agent is small, the particle size tends to be small. Therefore, by appropriately setting these polymerization conditions, high dielectric constant organic polymer fine particles having an average particle diameter in the range of 0.1 to 10 μm can be produced with high yield.

The high dielectric constant organic polymer fine particles of the present invention are:
Despite the high dielectric constant of 10-50, other organic materials,
For example, polymerizable monomers, oligomers, low molecular high dielectrics, can be directly and uniformly dispersed in low molecules such as liquid crystals, and organic polymer materials such as polystyrene, polycarbonate, PMMA, poval, and poval substituents include:
It can be easily and uniformly dispersed by dissolving or dispersing in a solvent and casting.

Therefore, the high dielectric constant organic polymer fine particles of the present invention can be used for various applications requiring a high dielectric material such as an EL device, a liquid crystal device and a capacitor.
In particular, the high dielectric constant organic polymer material of the present invention, in which high dielectric constant organic polymer fine particles are dispersed in an organic polymer material at a ratio of 5 to 90% by weight, is useful because it can be used for various applications. .

[0015]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

Example 1 In a reactor equipped with stirring blades, 90 ml of ethanol and 3 g of polyvinyl methyl ether were added and dissolved. Next, 5 g of cyanoethyl acrylamide, 0.5 g of trimethylpropane triacrylate (TMPTA, trifunctional crosslinking agent)
g, α, α'-azobisisobutyronitrile (AIB
N, polymerization initiator) in an amount of 0.01 g.
Polymerization was carried out at a temperature of ° C for 14 hours. The precipitate was collected by centrifugation, washed with ethanol, centrifuged,
After drying under vacuum at 40 ° C., 4.8 g of white fine particles (yield: 96)
%). The average particle size of the obtained fine particles is 0.50 μm.
m and the dielectric constant were 17.

Example 2 In a reactor equipped with a stirring blade, tetrahydrofuran (TH
F) 120 ml and 3 g of polystyrene were added and dissolved by heating to 70 ° C. Next, cyanoethylacrylamide 5
g, TMPTA 0.5 g, AIBN 0.01 g,
Polymerization was performed at a temperature of 60 ° C. for 12 hours under a nitrogen stream.
The precipitate was collected by centrifugation, washed with THF,
Centrifuge and dry under vacuum at 40 ° C. to obtain 1.2 g of white fine particles.
(24% yield). The obtained fine particles had an average particle size of 1.28 μm and a dielectric constant of 16.

Example 3 In a reactor equipped with stirring blades, 90 ml of ethanol and 3 g of polyvinyl methyl ether were added and dissolved. Next, 5 g of cyanoethylacrylamide, 0.5 g of TMPTA, A
0.01 g of IBN was added, and polymerization was carried out at 40 ° C. for 12 hours under a nitrogen stream. The precipitate was collected by centrifugation, washed with ethanol, centrifuged, and vacuum-dried at 40 ° C. to obtain 3.0 g of white fine particles (yield: 60%).
The obtained fine particles have an average particle size of 0.58 μm and a dielectric constant of 1
It was 7.

Example 4 In a reactor equipped with stirring blades, 90 ml of ethanol and 3 g of polyvinyl methyl ether were added and dissolved. Next, 2.5 g of cyanoethylacrylamide, 2.5 g of styrene monomer, 0.5 g of TMPTA and 0.01 g of AIBN were added, and polymerization was carried out at 40 ° C. for 12 hours under a nitrogen stream. The precipitate was collected by centrifugation, washed with ethanol, centrifuged, and vacuum-dried at 40 ° C. to obtain 3.0 g of white fine particles (yield: 60%). The average particle diameter of the obtained fine particles was 0.40 μm, and the dielectric constant was 8.

Comparative Example 1 90 ml of ethanol, 5 g of cyanoethylacrylamide, 0.5 g of TMPTA, AI were placed in a reactor equipped with stirring blades.
0.01 g of BN was added, and the mixture was heated at a temperature of 40 ° C.
Polymerization was carried out for hours. The precipitate was a white rice cake, and a polymer in the form of fine particles was not obtained.

Comparative Example 2 In a reactor equipped with a stirring blade, 90 ml of ethanol, 5 g of cyanoethyl hydroxymethacrylate, 0.1 g of TMPTA.
5 g and AIBN 0.01 g were added, and the mixture was heated at 40 ° C. under a nitrogen stream.
At a temperature of 5 hours. The precipitate was a white rice cake, and a polymer in the form of fine particles was not obtained.

Comparative Example 3 In a reactor equipped with stirring blades, 90 ml of ethanol, 2.5 g of cyanoethylacrylamide, and styrene monomer 2.
5 g, 0.5 g of TMPTA and 0.01 g of AIBN were added, and polymerization was carried out at a temperature of 40 ° C. for 4 hours under a nitrogen stream. The precipitate was a white rice cake, and a polymer in the form of fine particles was not obtained.

Example 5 1 g of the high dielectric constant organic polymer fine particles (average particle size: 0.50 μm) obtained in Example 1 was added to 10 g of THF, and the particles were dispersed for 5 minutes using an ultrasonic cleaning device. A dispersion was obtained. After heating and dissolving 1 g of polystyrene in THF, the above-mentioned fine particle dispersion is added and mixed, and the mixture is vacuumed to 40 g.
C. to obtain a white uniform film having a thickness of 100 μm. The dielectric constant of the obtained film was 12.

Example 6 3 g of the high dielectric constant organic polymer fine particles (average particle size: 0.50 μm) obtained in Example 1 were added to 10 g of acetone.
The dispersion treatment was performed for 5 minutes using an ultrasonic cleaning device to obtain a fine particle dispersion. After heating and dissolving 1 g of cyanoethyl poval in acetone, the above fine particle dispersion is added and mixed,
The film was cast at 30 ° C. in a vacuum to obtain a white uniform film having a thickness of 100 μm. The resulting film had a dielectric constant of 16.

Example 7 Example 5 was repeated except that the high dielectric constant organic polymer fine particles (average particle size was 0.58 μm) obtained in Example 3 were used as the high dielectric constant organic polymer fine particles. In the same manner as in the above, a white uniform film having a thickness of 100 μm was obtained. The resulting film had a dielectric constant of 11.

Example 8 Example 6 was repeated except that the high dielectric constant organic polymer fine particles (average particle size was 0.58 μm) obtained in Example 3 were used as the high dielectric constant organic polymer fine particles. In the same manner as in the above, a white uniform film having a thickness of 100 μm was obtained. The obtained film had a dielectric constant of 15.

Comparative Example 4 1 g of cyanoethyl pullulan (CE-pullulan) was dissolved in 10 g of acetone. After heating and dissolving 1 g of polystyrene in THF, the above solution was added and mixed.
As a result of casting at 40 ° C., cyanoethyl pullulan and polystyrene were separated, and a uniform film was not obtained.

Comparative Example 5 In Comparative Example 4, instead of cyanoethyl pullulan,
As a result of casting in the same manner as in Comparative Example 4 except that cyanoethyl saccharose (CE-saccharose) was used, cyanoethyl saccharose and polystyrene were separated, and a uniform film was not obtained.

Example 9 The high dielectric constant organic polymer fine particles obtained in Examples 1 and 3 were dispersed (dissolved) in a low molecular weight compound shown in Table 1 under the condition of a weight ratio of 1: 1. As shown, the dispersion was good. For comparison, CE-pullulane and CE-saccharose were also evaluated under the same conditions, and the results are shown in Table 1.

[0030]

[Table 1]

Example 10 A liquid crystal material (“E-8” manufactured by BDH) and the high dielectric constant organic polymer fine particles obtained in Example 1 were mixed in a weight ratio of 7.5:
Twenty parts by weight of the mixed part mixed at a ratio of 2.5 were mixed with 0.01 part by weight of a glass bead having a particle diameter of 20 μm as a spacer material, and sandwiched between transparent glass plates on which ITO was vapor-deposited. An element was produced and evaluated.

The dispersion type liquid crystal element was evaluated by applying a voltage of 50 Hz and measuring a change in light transmittance when the voltage was increased. The light transmittance was measured at a wavelength of 555 nm using an absorption altimeter. Table 2 shows the results. For comparison, a 20 μm-thick liquid crystal element produced using polystyrene fine particles having an average particle size of 1 μm instead of the high dielectric constant organic polymer fine particles was also evaluated under the same conditions. 2 is shown.

[0033]

[Table 2]

The liquid crystal device of the present invention in which the high-permittivity organic polymer fine particles are dispersed has excellent contrast due to the excellent dispersibility of the high-permittivity organic polymer fine particles in the liquid crystal, and has a high dielectric constant. Also, the characteristics are good with a low threshold voltage. On the other hand, the liquid crystal element in which the polystyrene fine particles were dispersed did not function as a liquid crystal because the dispersibility of the polystyrene fine particles in the liquid crystal was poor.

[0035]

As described above, the high dielectric constant organic polymer fine particles of the present invention described above can be easily compounded with other organic materials.
It can be used for various applications requiring an organic high dielectric such as a device, a liquid crystal device, and a capacitor.

Claims (5)

[Claims] 1. A dielectric material having a dielectric constant of 10 to 50 and an average particle size of 0.1.
High dielectric constant organic polymer fine particles having a particle size of from 10 to 10 μm. 2. The high dielectric constant organic polymer fine particles according to claim 1, which are mainly derived from a cyanoethyl compound. 3. The method according to claim 1, wherein the cyanoethyl compound is cyanoethylacrylamide, cyanoethylmethylolacrylamide,
The high dielectric constant organic polymer fine particles according to claim 2, which are compounds selected from the group consisting of cyanoethylhydroxyacrylate and cyanoethylhydroxymethacrylate. 4. The method according to claim 1, wherein the polymerizable cyanoethyl compound is solution-polymerized in a polymer solution. 5. A high dielectric constant organic polymer material comprising the organic polymer material and the high dielectric constant organic polymer fine particles according to claim 1 dispersed in a proportion of 5 to 90% by weight. .