JPH05287116A - Polymer composition containing copper @(3754/24)i) halide dispersed therein and production of polymer composition containing ultrafine particle of copper @(3754/24)i) halide dispersed therein - Google Patents

Abstract

PURPOSE:To obtain a polymer composition, containing ultrafine particles of a copper(I) halide dispersed therein, excellent in transparency, stability and environmental characteristics as a nonlinear optical material useful as one of a light wavelength cutting filter and an optoelectronic device material and having a controlled particle diameter. CONSTITUTION:A transparent polymer composition before depositing ultrafine particles is obtained by removing a nonaqueous solvent from a solution prepared by dissolving a copper(I) halide and a polymer in the solvent. The resultant polymer composition is then heated in a short time of <1min to produce the objective composition containing the ultrafine particles of the copper(I) halide, deposited and dispersed in the polymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper (I) halide superoxide used for a light wavelength cut filter such as a signal lamp, a light emitting material, or a non-linear optoelectronic material utilizing phase conjugate wave generation, an optical bistable phenomenon, etc. It relates to a fine particle dispersed polymer composition.

[0002]

2. Description of the Related Art Ultrafine particles in the present invention refer to particles having a particle diameter of 1 to 100 nanometers (nm). Ultrafine particles with such a small particle diameter have various optical and electrical properties and their chemical reactivity as compared with powders with a particle diameter of micrometer or more produced by ordinary mechanical pulverization. There are remarkable differences, and they are attracting attention as optical devices such as nonlinear optical materials and chemical catalysts.

It is known that by making copper (I) halide into ultrafine particles, exciton absorption clearly appears, and such a material gives high nonlinear optical characteristics. Further, in the application to a sharp cut filter or the like, similarly, the sharpness of rising of exciton absorption is utilized to bring out a sharp optical shielding property with respect to a wavelength.

Conventionally, several methods have been disclosed as a method for producing a copper (I) halide ultrafine particle dispersion having a property due to exciton absorption.

For example, Physica Status Solid
(Physica Status Solidi (b)) Volume 145, p. 567 (1988
(Year), sodium chloride and copper (I) chloride are mixed and then melted at a high temperature to form sodium chloride type crystals. When this crystal is heat-treated again, ultrafine particles of copper (I) chloride are deposited,
At this time, the particle diameter of the copper (I) chloride ultrafine particles produced is controlled by selecting conditions such as the reheat treatment temperature, time, and cooling process.

As a method similar to this, copper (I) halide is melted at a high temperature in a multi-component oxide glass instead of sodium chloride, rapidly cooled, and then reheated to form ultrafine particles. Precipitating (AIEkim
ov et al., Laser Optics of Condensed Matter, 1988.
Year, p. 199).

[0007] In the proceedings of the Autumn Meeting of the Physical Society of Japan, 2nd volume, p. 216 (1988), copper (I) chloride ultrafine particles are produced by simultaneous evaporation of silicon oxide and copper (I) chloride. A material dispersed in silicon oxide glass is obtained.

In these conventional methods,
Since it is prepared and prepared by a fairly high temperature process, heat resistance is required for the substrate on which the material and the thin film in which the material is dispersed are placed, and special measures must be taken for temperature control.

Further, the materials obtained by these conventional methods are difficult to be formed into a thin film or a film shape due to restrictions imposed by the preparation method and the material. Therefore,
When actually used as a non-linear optoelectronic material, a thin film waveguide form is required, which is a practical problem. Further, in consideration of utilization as an industrial technology, there are problems in terms of manufacturing cost, large area, and the like.

As a means for solving the above problems, the inventors of the present invention have an idea of synthesizing a composition in which ultrafine particles are dispersed in a polymer medium in a short time in terms of forming a thin film or a film. Came to.

However, according to our study, in general, a copper (I) halide crystal is prepared in the presence of a divalent copper ion and a halogen anion in an aqueous solution, for example.
Although it can be synthesized by reducing with a reducing agent, it is not easy to generate it in a colloidal form without aggregation or precipitation. Further, when synthesized in an aqueous solution, even if a copper (I) halide colloid is produced, the kind of polymer capable of producing a dispersion in a polymer medium from the aqueous solution is extremely limited.

Further, among the copper (I) halides, copper (I) chloride and copper (I) bromide are very easily oxidized by the humidity in the air, so that they are water-soluble polymers having high hygroscopicity. Is unbearable to use as it is.

As described above, according to the conventional method, it was extremely difficult to prepare a stable composition in which copper (I) halide ultrafine particles were dispersed in a thin film or film-shaped polymer. From a practical point of view, as a medium of a composition in which copper (I) halide ultrafine particles are dispersed, a copper (I) halide ultrafine particles using a polymer medium whose manufacturing method and material properties are fundamentally different from those of inorganic crystals and glass. It is desirable to create a dispersion.

[0014]

As convenient properties imparted to ultrafine particles or ultrafine particle dispersions (especially ultrafine particle / polymer compositions) as optical materials such as wavelength cut filters and nonlinear optical materials, various applications are available. There are some differences, but the main items are as follows. That is, 1. Ultrafine particles are stably present. 2. It has excellent transparency. 3. Excellent environmental characteristics. 4. The particle size is controlled. And so on.

In order to satisfy these points, that is, to develop an ultrafine particle dispersion in which ultrafine particles are stably present, have excellent transparency and environmental characteristics, and the particle size of the ultrafine particles is controlled. The inventors have found a method for preparing a composition in which copper (I) halide ultrafine particles are dispersed in a polymer.

[0016]

A feature of the present invention is to provide a precursor polymer composition for synthesizing a copper (I) halide ultrafine particle polymer dispersion composition by a heating reaction for a short time, and a precursor polymer composition thereof. In heat treatment.

The contents of the present invention will be described in detail below. The ultrafine particles in the present invention have a particle diameter of 1 to 100.
Refers to particles of nanometers (nm), preferably 1-20 nanometers. The diameter in this case may be the diameter of the primary particles or may be the secondary particles formed by agglomeration of the primary particles, but in any case, the transparency to visible light is expressed. Therefore, particles having a diameter of more than 100 nm are not preferable in terms of light scattering. Also,
The term "transparent" in the present invention means that there is no turbidity or scattering,
Of course, the wavelength region due to absorption peculiar to the particles is not included.

The compound composition of the copper (I) halide in the present invention is represented by the formula: CumXn, where X represents a halogen element, and n for m = 1.
= 1 to 1.8, preferably n = 1 to 1.5.

The polymer used in the present invention is a polymer having transparency and is soluble in the solvent to be used, and even if it is soluble in a non-aqueous solvent in which copper (I) halide is dissolved, it is difficult. It may be soluble, but is preferably soluble.

Specific examples of preferred polymers include:
Polymethylmethacrylate (PMMA), polyethylmethacrylate, polycarbonate (PC), polystyrene (PS), polyester, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polysulfone, polyvinyl butyral (PVB), polyether sulfone (PES) , Vinyl chloride and vinyl acetate copolymers, maleic anhydride and styrene copolymers,
Examples thereof include copolymers of styrene and acrylonitrile, and mixtures thereof.

Next, the method for preparing the copper (I) halide ultrafine particle dispersed polymer composition will be described in detail.

Copper (I) halide is dissolved in a non-aqueous solvent (step A). It suffices if the copper (I) halide is dissolved in the non-aqueous solvent (step A), but the standard of concentration is 1 × 10 ⁻⁴ to 1 mol / liter, and from the viewpoint of easy handling, preferably 1 × 10 ^{−. 3} ~
Prepare a solution in the range of 1 × 10 ^-1 mol / liter.

The non-aqueous solvent (A) is preferably a solvent having a large polarity, and specific examples include alcohols such as methanol and ethanol, nitriles such as acetonitrile, propionitrile, butyronitrile and benzonitrile, acetone, Examples thereof include ketones such as methyl ethyl ketone, and mixed solvents containing these. More preferably, a nitrile compound having a very high solubility in copper (I) halide is used.

Next, a solution is prepared by dissolving the polymer in a non-aqueous solvent (B). Polymer used is non-aqueous solvent (Otsu)
It should be dissolved in, but as a guideline for the concentration, it is 1-1000 g / liter, and from the viewpoint of easy handling, it is preferably 1-5.
Prepare a solution in the range of 00 grams / liter.

As the non-aqueous solvent (B), the non-aqueous solvent (A)
Although the same solvent as described above can be used, a solvent having a lower polarity than the nonaqueous solvent (A) used can also be used. For example, chloroform, dichloroethane, ethyl acetate, toluene, benzene and the like can be mentioned.

The prepared copper (I) halide solution dissolved in the non-aqueous solvent (A) and the polymer solution dissolved in the non-aqueous solvent (O) are mixed. At this time, copper (I) halide
May be soluble or sparingly soluble in the non-aqueous solvent (B), and similarly, the polymer may be soluble or sparingly soluble in the non-aqueous solvent (A). It suffices that there is no precipitate when the solutions are mixed and they are dissolved uniformly.

The mixing ratio is such that the ratio of polymer to copper (I) halide in the mixed solution is 1 × 10 ⁻⁶ to 1 × 10 ⁻² mol, preferably 1 ×, with respect to 1 gram of polymer. Ten
It is desirable to prepare copper (I) halide in an amount of about ^-5 to 1 x 10 ^-3 mol.

Then, the solvent is removed from the prepared solution in which the copper (I) halide and the polymer are co-dissolved.

Air-drying or vacuum-drying, and a combination thereof are conceivable as the removing method. However, in the case of air-drying, an inert gas is considered in consideration of the fact that the copper (I) halide is easily attacked by moisture in the air. It is preferably carried out in an atmosphere.

The transparent polymer composition obtained by removing the solvent is in a state where there is no fluidity and ultrafine particles are not deposited in the composition, and even if a small amount of the non-aqueous solvent remains. It doesn't matter. This polymer composition is an important intermediate in the synthesis of copper (I) halide ultrafine particle dispersed polymer composition. The degree of removal of the solvent, that is, the degree of drying is a factor that controls the particle diameter of the ultrafine particle precipitation in the subsequent heat treatment. The higher the degree of drying, the smaller the copper (I) halide ultrafine particles can be synthesized. Although the process of removing the solvent also depends on the solvent used, the temperature is generally in the range of 0 ° C to 50 ° C, preferably at about room temperature. It can be adjusted by the time of air drying or the time of vacuum drying.

The transparent polymer composition thus prepared is heated for a heating time of less than 1 minute. Of course, even if heat treatment is performed for a longer time, ultrafine particles are precipitated and a copper (I) halide ultrafine particle-dispersed polymer composition can be obtained. However, the advantage of synthesizing ultrafine particles by heating for such an extremely short time is advantageous. Examples of the polymer include that the polymer as the dispersion medium is not damaged, deterioration is prevented, and productivity is high.

As a heating method, the prepared transparent polymer composition may be brought into contact with a heating medium such as heating gas, heating oil, or heating metal. The higher the heating temperature, the finer the particles of copper (I) halide having a smaller particle size, and the higher the degree of drying, the more the particles having a smaller particle size tend to deposit due to heating. It is possible. The heating temperature is not a problem as long as the precipitation of fine particles starts and the polymer is not damaged, but preferably 50
℃ ~ 200 ℃.

After the heat treatment, the temperature is rapidly cooled to 50 ° C. or lower. Then, it is desirable to perform drying in order to further remove the solvent from the polymer. The drying method includes air drying or vacuum drying, and a combination thereof, and the drying temperature is 0.
C. to 50.degree. C., preferably about room temperature.

Further, a coexisting mixed solution of a copper (I) halide solution dissolved in a non-aqueous solvent (A) and a polymer dissolved in a non-aqueous solvent (O) or a solution concentrated to some extent is a usual thin film forming method. By applying the casting method, it is possible to easily form a thin film such as a film or a plate of the transparent polymer composition or the ultrafine particle dispersed polymer composition. As a matter of course, another method that is a method for forming a thin film from a general polymer composition, for example, a spin coating method, a bar coating method using a doctor blade, a dip method, a roll coating method, or the like is used to form a thin film. It is also possible to obtain a film-shaped composition.

Whether or not ultrafine particles are produced, or the method of observing and identifying the produced ultrafine particles, are known methods such as X-ray diffraction analysis, ultrathin section sample transmission electron microscope observation, and electron beam diffraction. Analysis or the like can be used.

Further, from the UV-visible absorption spectrum of the polymer composition, it is possible to easily estimate the presence or absence of the formation of ultrafine particles and the particle diameter of the ultrafine particles. This is because copper (I) halide crystals show absorption by excitons due to electron-hole pairs having a large binding energy, and the absorption maximum position changes depending on the diameter of the ultrafine particles. That is, when the particle size of the ultrafine particles becomes smaller, the maximum position of the ultraviolet-visible absorption spectrum of excitons shifts by a short wavelength by the amount of the confinement energy.

[0037]

EXAMPLES The present invention will be described in more detail based on the following examples. Example 1 0.0066 g of copper (I) bromide (CuBr) in acetonitrile
Dissolve in 2.0 ml and add chloroform to make 5 ml. Remove 1.0 ml from this solution, 0.44 g PMMA
Add the chloroform solution to dissolve in the solution to make 2.0 ml. This solution is spread on a 6 cm Petri dish and left at room temperature for 6 hours under an atmosphere of flowing N ₂ . Further, this was placed in a vacuum box of 1 mmHg and vacuumed, and after 24 hours, this was taken out, and a film-like transparent polymer composition as a precursor for obtaining a copper (I) bromide ultrafine particle dispersed polymer composition. Is obtained. No precipitation of ultrafine particles was observed in the ultraviolet-visible absorption spectrum or electron microscope observation.

Example 2 The transparent polymer composition prepared according to Example 1 was prepared as 105
Heated at 0 ° C for 20 seconds. The polymer remained transparent, and the average particle diameter in the polymer was 8.5 nanometers (85 nm) by UV-visible absorption spectrum, X-ray diffraction analysis and transmission electron microscopy.
It was confirmed that ultrafine copper (I) bromide particles of angstrom) were generated. The third-order nonlinear susceptibility (χ ⁽³⁾ ) of this film-like composition was measured at 355 nm by a phase conjugate wave generation type degenerate four-wave mixing method.
A value of × 10 ^-11 esu was obtained.

Comparative Example 1 The transparent polymer composition prepared according to Example 1
Heat at 1 ° C for 1 minute 30 seconds. It was confirmed that copper (I) bromide ultrafine particles with an average particle diameter of 9 nanometers (90 angstroms) were generated in the polymer, but the film-shaped polymer was slightly bent, and the dispersion density of the ultrafine particles was It was almost the same as Example 2.

Example 3 The transparent polymer composition prepared according to Example 1
Heated at 0 ° C for 10 seconds. The polymer remained transparent, the exciton maximum position in the UV-visible absorption spectrum was shifted by a short wavelength, and the average particle diameter was smaller than that in Example 2 by X-ray diffraction analysis and transmission electron microscope observation.
It was confirmed that nanometer (72 angstrom) copper (I) bromide ultrafine particles were formed in the film. That is, it is understood that the particle size can be controlled by adjusting the heating temperature.

Example 4 A film-like transparent polymer composition was obtained in the same manner as in Example 1 except that the drying time in the vacuum box was increased to 48 hours. An ultraviolet-visible absorption spectrum and an electron microscope were used. Upon observation, precipitation of ultrafine particles was not seen.

Example 5 The clear polymer composition prepared according to Example 4 was
Heated at 0 ° C for 10 seconds. The polymer remained transparent, the maximal position of exciton in the UV-visible absorption spectrum was shifted by a shorter wavelength than that of Example 3, and the particle size was larger than that of Example 3 by X-ray diffraction analysis and transmission electron microscope observation. It was confirmed that copper (I) bromide ultrafine particles having a small average particle diameter of 6.4 nanometers (64 angstroms) were formed in the film. That is, it is understood that it is possible to control the particle size of the ultrafine particles by adjusting the degree of drying of the precursor transparent polymer composition. The third-order nonlinear susceptibility (χ ⁽³⁾ ) of this film-like composition was calculated as 355
A value of 1.5 × 10 ⁻¹¹ esu was obtained when measured by a degenerate four-wave mixing method of the phase conjugate wave generation type in nm.

Comparative Example 2 The transparent polymer composition prepared according to Example 4 was
Heat at 1 ° C for 1 minute 30 seconds. Average particle diameter in polymer 6.8
Although it was confirmed that nanometer (68 angstrom) copper (I) bromide ultrafine particles were formed, the film-shaped polymer was considerably deflected, and the density of the ultrafine particles was almost the same as in Example 5. ..

Example 6 0.006 g of copper (I) chloride (CuCl) was added to acetonitrile.
Dissolve in 2.0 ml and add chloroform to make 5 ml. Remove 1.0 ml from this solution, 0.44 g PMMA
Add the chloroform solution to dissolve in the solution to make 2.0 ml. This solution was spread on a 6 cm Petri dish and left for 1 hour at 45 ° C. in an atmosphere of N ₂ flow, then 1 mmH
g in a vacuum box, vacuumed, and left for 6 hours. Then, a film-like transparent polymer composition, which is a precursor for obtaining a copper (I) chloride ultrafine particle dispersed polymer composition, is obtained. No precipitation of ultrafine particles was observed in the ultraviolet-visible absorption spectrum or electron microscope observation.

Example 7 The clear polymer composition prepared according to Example 6 was treated at 90 ° C.
Heated for 30 seconds. The polymer remains transparent, and ultrafine copper (I) chloride particles having an average particle diameter of 15 nanometers (150 angstroms) are formed in the polymer by UV-visible absorption spectrum, X-ray diffraction analysis and transmission electron microscope observation. Was confirmed.

Comparative Example 3 The transparent polymer composition prepared according to Example 6 was treated at 90 ° C.
Heated for 2 minutes. It was confirmed that copper (I) chloride ultrafine particles with an average particle diameter of 15 nanometers (150 angstroms) were formed in the polymer, but the film-shaped polymer was slightly bent, and the colorless film was slightly brownish. Was coming. This suggests that copper (I) chloride has reacted and partially changed.

[0047]

EFFECT OF THE INVENTION The precursor transparent polymer composition for synthesizing ultrafine particles obtained by the present invention is used for synthesizing a copper (I) halide ultrafine particle-dispersed polymer composition having an average particle diameter of 1 to 20 nm. Since it is an excellent intermediate compound, it is possible to provide a copper (I) halide ultrafine particle-dispersed polymer composition which is highly transparent even by heat treatment for a short time and has excellent environmental characteristics. Since a wide range of product forms can be selected, a material having favorable properties for an optical wavelength cut filter or a nonlinear optical material is provided. The obtained copper (I) halide ultrafine particle-dispersed polymer composition has a lower production cost than a dispersion composition using an inorganic compound such as glass or sodium chloride as a medium, or a composition prepared by vapor deposition.

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Claims (4)

[Claims] 1. A transparent polymer composition obtained by removing a solvent from a solution in which a copper (I) halide and a polymer are co-dissolved in a non-aqueous solvent. 2. A transparent polymer composition according to claim 1
A method for producing a copper (I) halide ultrafine particle-dispersed polymer composition, which comprises heating for a heating time of less than a minute to precipitate ultrafine particles. 3. A transparent polymer composition formed into a thin film by removing a solvent from a solution in which a copper (I) halide and a polymer coexist and dissolve in a non-aqueous solvent. 4. The transparent polymer composition according to claim 3
A method for producing a thin film copper (I) halide ultrafine particle-dispersed polymer composition, characterized by heating for a heating time of less than a minute to precipitate ultrafine particles.