JPH09198926A - Conductive polymer composition and method for producing the same - Google Patents

Abstract

(57) Abstract: To provide a polymer composition excellent in various properties such as conductivity, durability and transparency, and a method for producing the same. SOLUTION: A conductive metal oxide precursor is dissolved in a solution containing an organic polymer component and an inorganic sol component, dried, and then heat treated to convert the precursor into a conductive metal oxide. And a method for producing the same.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polymer composition having conductivity and a method for producing the same.

[0002]

2. Description of the Related Art Conductive materials are widely used for various applications such as electromagnetic field shield materials, antistatic materials, heating elements, energy conversion elements, transparent electrodes and the like. As conductors used for these purposes, conductive fine particles such as metal and carbon, thin films such as indium oxide and tin oxide, and organic conductive polymers are known to date.

The conductive fine particles are dispersed in an organic polymer matrix and then molded, and the conductive fine particles are brought into physical contact with each other to become a conductor. For this reason, the electrical properties are affected by the mixing ratio, shape, molding conditions, etc. of the conductive particles, and there is a problem that the conductivity is lowered due to mechanical deformation, oxidation of the particle surface, and the like. Further, the conventional conductive fine particles cannot be applied to a field requiring transparency such as a transparent electrode.

Thin films of indium oxide, tin oxide, etc. are commonly used as transparent conductors. However, in order to obtain a good quality transparent conductive film, it is necessary to use a CVD method or a sputtering method that requires vacuum equipment, which increases the production cost of the film and makes it difficult to increase the area. have.

Since the organic conductive polymer has an organic component in its skeleton, various performances such as durability and conductivity are not sufficient, and there are many problems.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polymer composition having electrical conductivity which does not have the above-mentioned problems or drawbacks, and a method for producing the same.

Another object of the present invention is to provide a polymer composition excellent in various properties such as conductivity, durability and transparency and a method for producing the same.

Further objects and features of the present invention will be apparent from the following description.

[0009]

According to the present invention, a conductive metal oxide precursor is dissolved in a solution containing an organic polymer component and an inorganic sol component, dried and then heat-treated to render the precursor conductive. A polymer composition having conductivity obtained by converting into a conductive metal oxide, and a conductive metal oxide precursor dissolved in a solution containing an organic polymer component and an inorganic sol component, dried, and then heated. Provided is a method for producing a polymer composition having conductivity, which comprises treating the precursor to convert it to a conductive metal oxide.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, as the conductive metal oxide precursor, conventionally known ones can be widely used as long as they can be uniformly dissolved in the dried organic polymer. In other words, the conductive metal oxide precursor of the present invention is
Those that are soluble in a solution containing an organic polymer and exist as a molecular assembly of several hundred molecules or less in the organic polymer after drying, preferably in a solution containing an organic polymer and in the organic polymer after drying Exist as a molecule or a molecular aggregate of tens of molecules or less.

The conductive metal oxide precursor is not particularly limited as long as it is a transition metal salt or complex compound that can be converted into a conductive metal oxide, and conventionally known ones can be used. Can be widely used.

Examples of the transition metal include copper, indium, tin, zinc, titanium, cadmium, scandium, vanadium, chromium, manganese, iron, cobalt, nickel, gallium, strontium, yttrium, zirconium, molybdenum, technetium, ruthenium. ,
Odium, palladium, silver, antimony, hafnium,
Tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, thallium, lead, bismuth, scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium,
Europium, gadolinium, terbium, thulium,
Ytterbium, lutetium, etc. can be mentioned.
Among these transition metals, tin, indium, copper, zinc,
Titanium, vanadium, bismuth, iron, scandium, yttrium, lanthanum, neodymium, samarium, europium, terbium, ytterbium, lutetium and the like are preferable.

The organic salt or inorganic salt that is a salt of the transition metal is composed of a cation and an anion of the transition metal. Here, as the anion, for example, F ⁻ , Cl ⁻ , Br
^-, I ^-, CN ^- acid radical binary acids such as, CH ₃ COO ^-, H
Examples thereof include acid radicals of oxo acids such as COO ⁻ , SO ₄ ⁻² , NO ₃ ⁻ , ClO ₄ ⁻ and PO ₄ ⁻³ . The salt of the transition metal used in the present invention may be any of a single salt consisting of one type of each of the cation and anion, a double salt consisting of two or more types, and a triple salt.

The transition metal complex compound comprises a transition metal cation and a ligand. Examples of the ligand include acetylacetonato group, acetato group, aryl group, 2,2′-bipyridine, benzyl group, 1,5-cyclooctadiene, cyclooctatetraene, cyclopentadienyl group, cyclohexyl group, Examples include N, N-dimethylformamide, dimethyl sulfoxide, triphenylphosphine and the like.

In the present invention, as the precursor of the conductive metal oxide, one type of the above-mentioned transition metal salt and complex compound may be used alone, or two or more types may be used in combination.

In carrying out the present invention, the above conductive metal oxide precursor is dissolved in a solution containing an organic polymer component and an inorganic sol component, and then this is dried to obtain a molded body.

In the present invention, the organic polymer component is an organic polymer having an interaction such as coordination, electrostatic charge, hydrogen bond, chemical bond and the like with the conductive metal oxide precursor.

The organic polymer component is not particularly limited as long as it has the ability to dissolve the conductive metal oxide precursor, but a cellulose polymer is preferable.

The cellulosic polymer is a polymer in which glucose units are repeated or a derivative thereof, and typically, for example, carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate phthalate, ethyl hydroxyethyl cellulose, Examples include cellulose-based water-soluble polymers such as carboxymethyl ethyl cellulose.

As the organic polymer component, for example,
Natural water-soluble polymers such as gelatin, collagen protein, casein, agar, carrageenan, furceleran, tamarind gum, pectin and natural gum, polyethyleneimine, polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, polyoxazoline, polyacrylamide, poly N, N- Dimethyl acrylamide,
Synthetic water-soluble polymers such as polyacrylic acid, polypropylamine, polymethacrylic acid, poly N-vinylformamide, and poly N-vinylacetamide may be used.

In the present invention, the above organic polymer components may be used alone or in combination of two or more. Further, it may be any of block, alternating, random and graft copolymers of each monomer constituting the organic polymer component.

Examples of the inorganic sol component in the present invention include silica sol, alumina sol, titanium oxide sol, zirconium oxide sol, iron oxide sol, barium titanate sol, aluminum phosphate sol and the like.
In the present invention, the above inorganic sol components may be used alone or in combination of two or more.

The above-mentioned inorganic sol component can be suitably prepared, for example, by hydrolyzing and condensing a metal compound such as alkoxide or salt of a corresponding metal. Examples of such metal compounds include tetraethoxysilane,
Tetramethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltriethoxysilane, methyltripropoxysilane, ethyl Tripropoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dipropyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane,
γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, diphenyldimethoxysilane , Organic silicon compounds such as diphenyldiethoxysilane, aluminum ethoxide, aluminum butoxide, organic aluminum compounds such as aluminum methoxide, aluminum chloride, inorganic aluminum compounds such as aluminum phosphate, titanium
(IV) ethoxide, titanium (IV) isopropoxide, iron chloride, zirconium ethoxide and the like can be mentioned.

As the solvent constituting the solution containing the organic polymer component and the inorganic sol component, any of an organic solvent, water or a mixture thereof may be used, but methanol,
Preferable examples include alcohol solvents such as ethanol and propanol, ester solvents such as ethyl acetate and butyl acetate, aromatic solvents such as toluene, benzene and xylene, ether solvents such as diethyl ether and tetrahydrofuran, and water. These solvents may be used alone or in combination of two or more.

In dissolving the conductive metal oxide precursor in a solution containing an organic polymer component and an inorganic sol component, the weight ratio of the precursor, the organic polymer component and the inorganic sol component is not particularly limited. , Preferably the precursor /
Weight ratio of organic polymer component = 1/100 to 10/1,
Weight ratio of organic polymer component / inorganic sol component = 1/100
It is good to set it to 100/1. More preferably, the weight ratio of the precursor / organic polymer component = 1/10 to 2/1, and the weight ratio of the organic polymer component / inorganic sol component = 1/10 to 1
It is good to set it to 0/1.

The solid content concentration of the solution obtained by dissolving the precursor in a solution containing an organic polymer component and an inorganic sol component is
Although not particularly limited, it is preferably 1 to 50% by weight, more preferably 1 to 15% by weight.

In the present invention, the subsequent drying may be natural drying or heat drying. In the case of heat drying, the drying temperature is usually 30 to 300.
C, preferably 40 to 150C. The drying time is not particularly limited as long as the solvent can be removed, but it is preferably about 1 minute to 60 minutes. By this drying treatment, molded articles of various shapes are usually formed.

In the present invention, the precursor is then dried and then heat-treated to convert the precursor into a conductive metal oxide to obtain a conductive polymer composition. By this heat treatment, the metal oxide precursor is decomposed and converted into a metal oxide. The optimum heating temperature varies depending on the decomposition temperature of the metal oxide precursor, but is generally about 200 to 1000 ° C,
It is preferably 250 to 800 ° C. The heating time is generally about 0.5 to 50 hours. Depending on the heating time,
The particle size and crystallinity of the metal oxide change. The heating atmosphere is not particularly limited, but an oxidizing atmosphere such as air and oxygen, a reducing atmosphere such as hydrogen and an inert atmosphere such as nitrogen and argon can be used. Of these, the preferred one is
It is an oxidizing atmosphere.

Thus, the electric conductor, which is the polymer composition having electric conductivity of the present invention, is obtained.

The above method of the present invention is particularly suitable for producing a film conductor. The film forming method is not particularly limited, but for example, a dipping method, a spin coating method, a spray method,
A coating method, a printing method and the like. The thickness of the film is not particularly limited, but it is preferably 1 nm to 100 μm, more preferably 100 nm to 10 μm.

Further, the method of the present invention, in addition to the film conductor,
It can also be applied to the production of particulate conductors, linear conductors, and the like.

In the method of the present invention, a polymer composition such as a conductive film can be produced only by using a solution of a conductive metal oxide containing an organic polymer component and an inorganic sol component. A conductive film or the like can be produced by mixing with a surface treatment agent such as paint or paint.
Specifically, a conductive metal oxide precursor is dissolved in the above solution, which is mixed with a hard coat solution or the like, dried, and then converted into a conductor, or an organic polymer component,
A desired conductive film or the like can be produced by dissolving a conductive metal oxide precursor in a solution containing an inorganic sol component, a hard coat liquid, etc., drying it, and then converting it into a conductor.

The conductive component of the conductor produced by the present invention is
It is a metal oxide. The conductive film produced by the present invention usually has a surface resistance of about 10 ¹¹ Ω / □ to 10 ¹ Ω / □. Further, according to the method of the present invention, a transparent conductive film can be suitably obtained. Here, “transparent” in the present invention means
This means that the transmittance for light of 500 nm is 90 to 50%. The surface resistance is JIS K6911.
It was measured in accordance with.

The resistance value of the conductive film produced by the present invention may vary greatly depending on the measurement atmosphere such as humidity and the concentration of alcohol, carbon monoxide, ammonia, carbon dioxide, oxygen, aldehyde and the like. . In this case, it can be suitably used as a gas sensor.

[0035]

EXAMPLES The present invention will be further clarified with reference to the following examples.

Example 1 To 10 g of tetraethoxysilane, 1.5 g of methanol, 2.1 g of distilled water and 0.1 g of 35% hydrochloric acid were added and reacted at room temperature for 30 minutes with stirring to prepare a silica sol. Tin (IV) chloride dissolved in 100 ml of methanol
A coating solution was prepared by adding 40 ml and a solution of 5 g of hydroxypropyl cellulose. With this,
By the dipping method at a pulling rate of 15 cm / min.
A film was formed on the glass substrate. Then, this is air-dried at room temperature for 1 to 3 minutes, and then the film is heated in air at 400 ° C. for 1 hour to convert tin chloride to tin oxide, thereby forming a transparent conductive film having a thickness of 0.5 μm. Obtained. The surface resistance and transparency of the obtained conductive film are shown in Table 1 below.

[0037]

[Table 1]

Example 2 A tin chloride film as a precursor prepared by the same method as in Example 1 was heated in air at 400 ° C. for 5 hours to convert tin chloride into tin oxide, so that the film thickness was 0. A transparent conductive film of 5 μm was obtained. The surface resistance and transparency of the obtained conductive film are shown in Table 2 below.

[0039]

[Table 2]

Example 3 A precursor film produced by the same method as in Example 1 was used in air for 35
After heating at 0 ° C. for 1 hour, a precursor film is further formed on the film by the same method as in Example 1, and 350 ° C. in air for 1 hour.
Heated for hours. This operation was repeated 3 times to obtain a transparent conductive film having a thickness of 1.3 μm in which tin chloride was converted to tin oxide. The surface resistance and transparency of the obtained conductive film are shown in Table 3 below.

[0041]

[Table 3]

Example 4 To 10 g of tetraethoxysilane, 1.5 g of methanol, 2.1 g of distilled water and 0.1 g of 35% hydrochloric acid were added and reacted at room temperature for 30 minutes while stirring to prepare a silica sol. Tin (IV) chloride dissolved in 100 ml of methanol
A coating solution was prepared by adding 40 ml and a solution of 1 g of hydroxypropyl cellulose. With this,
By the dipping method at a pulling rate of 15 cm / min.
A film was formed on the glass substrate. Then, this is air-dried at room temperature for 1 to 3 minutes, and then the film is heated in air at 350 ° C. for 1 hour to convert tin chloride to tin oxide, thereby forming a cloudy conductive film having a film thickness of 0.5 μm. Got The surface resistance and transparency of the obtained conductive film are shown in Table 4 below.

[0043]

[Table 4]

The relationship between the film resistance of the obtained conductive film and the relative humidity is shown in FIG.

Here, the film resistance of the conductive film was measured by a two-terminal method by attaching electrodes to the film surface by gold vapor deposition. Also,
Humidity was controlled by adjusting the mixing ratio of both nitrogen gas introduced into the measurement cell and nitrogen saturated with water vapor.

Example 5 To 10 g of tetraethoxysilane, 1.5 g of methanol, 2.1 g of distilled water and 0.1 g of 35% hydrochloric acid were added and reacted at room temperature for 30 minutes with stirring to prepare a silica sol. A solution of 20 g of indium chloride and 5 g of hydroxypropyl cellulose dissolved in 100 ml of methanol was added thereto to prepare a coating solution. Using this, a film was formed on the glass substrate by a dipping method at a pulling rate of 15 cm / min. Then, after air-drying this at room temperature for 1 to 3 minutes, the membrane was dried in air at 450 ° C. for 2 minutes.
By heating for a period of time, indium chloride was converted to indium oxide to obtain a transparent conductive film having a film thickness of 0.5 μm. The surface resistance and transparency of the obtained conductive film are shown in Table 5 below.

[0047]

[Table 5]

Example 6 To 10 g of tetraethoxysilane, 1.5 g of methanol, 2.1 g of distilled water and 0.1 g of 35% hydrochloric acid were added and reacted at room temperature for 30 minutes while stirring to prepare a silica sol. A solution of 20 g of indium chloride, 3 ml of tin (IV) chloride and 5 g of hydroxypropylcellulose dissolved in 100 ml of methanol was added thereto to prepare a coating solution. Using this, a film was formed on the glass substrate by a dipping method at a pulling rate of 15 cm / min.
Then, this is air-dried at room temperature for 1 to 3 minutes, and then the film is heated in air at 400 ° C. for 1 hour to convert indium chloride to indium oxide and tin chloride to tin oxide to obtain a film thickness of 0. A transparent conductive film having a thickness of 0.5 μm was obtained. The surface resistance and transparency of the obtained conductive film are shown in Table 6 below.

[0049]

[Table 6]

Example 7 To 10 g of tetraethoxysilane, 1.5 g of methanol, 2.1 g of distilled water and 0.1 g of 35% hydrochloric acid were added, and reacted at room temperature for 30 minutes while stirring to prepare a silica sol. Copper acetate 10 dissolved in 100 ml of methanol
and a solution of 5 g of hydroxypropyl cellulose were added to prepare a coating solution. With this, 15cm
A film was formed on the glass substrate by a dipping method at a pulling rate of / min. It is then allowed to reach 1-3 at room temperature.
After air-drying for a minute, the film was heated in air at 400 ° C. for 1 hour to convert the copper acetate into copper oxide, and the film thickness of 0.
A 5 μm colored transparent conductive film was obtained. The surface resistance and transparency of the obtained conductive film are shown in Table 7 below.

[0051]

[Table 7]

Example 8 To 10 g of tetraethoxysilane, 1.5 g of methanol, 2.1 g of distilled water and 0.1 g of 35% hydrochloric acid were added, and reacted for 30 minutes at room temperature with stirring to prepare a silica sol. Zinc acetate 1 dissolved in 100 ml of methanol
A coating solution was prepared by adding a solution of 0 g and 5 g of hydroxypropyl cellulose. With this, 15
A film was formed on the glass substrate by a dipping method at a pulling rate of cm / min. Then it is allowed to
After air-drying for 3 minutes, the film was heated in air at 400 ° C. for 1 hour to convert zinc acetate into zinc oxide to obtain a transparent conductive film having a film thickness of 0.5 μm. The surface resistance and transparency of the obtained conductive film are shown in Table 8 below.

[0053]

[Table 8]

Example 9 10 g of aluminum ethoxide was mixed with 1.5 of methanol.
g, 4 g of distilled water and 0.1 g of 35% hydrochloric acid were added and reacted at room temperature for 30 minutes with stirring to prepare an alumina sol. Tin chloride (I
A coating solution was prepared by adding a solution of 40 ml of V) and 5 g of hydroxypropyl cellulose. Using this, a film was formed on the glass substrate by a dipping method at a pulling rate of 15 cm / min. Then, this was air-dried at room temperature for 1 to 3 minutes, and then the film was dried in air at 400 ° C.
By heating for a period of time, tin chloride was converted to tin oxide, and a white turbid conductive film having a thickness of 0.5 μm was obtained. The surface resistance and transparency of the obtained conductive film are shown in Table 9 below.

[0055]

[Table 9]

The relationship between the film resistance of the obtained conductive film and the relative humidity is shown in FIG.

Here, the film resistance of the conductive film was measured by a two-terminal method by attaching electrodes to the film surface by gold vapor deposition. Also,
Humidity was controlled by adjusting the mixing ratio of both nitrogen gas introduced into the measurement cell and nitrogen saturated with water vapor.

[0058]

INDUSTRIAL APPLICABILITY According to the present invention, a polymer composition excellent in various properties such as conductivity, durability and transparency can be produced. The polymer composition can be molded into various shapes such as a film conductor, a particulate conductor, and a linear conductor, if necessary.

In carrying out the method of the present invention,
Since the polymer composition of the present invention can be produced without applying a CVD method or a sputtering method requiring vacuum equipment, a desired polymer composition can be obtained at low cost, and a large-area conductive film or the like can be produced. It will be possible.

Therefore, the conductive polymer composition of the present invention can be expected to be applied in various fields where transparency, high durability and high conductivity are required. For example, antistatic film for CRTs of computers, TVs, etc .; transparent film for EMI countermeasures of electronic parts; low-cost transparent electrode material; energy-saving heat-shield glass (window glass, car glass);
It can be used for radio wave absorption, reflection glass, EL element (carrier generation, transportation, light emitting layer are integrated); OPC material; energy conversion element, gas sensor, etc.

[Brief description of the drawings]

FIG. 1 shows the relationship between the film resistance and the relative humidity of the conductive film obtained in Example 4.

FIG. 2 shows the relationship between the film resistance of the conductive film obtained in Example 9 and the relative humidity.

Claims (7)

[Claims] 1. A conductive material obtained by dissolving a conductive metal oxide precursor in a solution containing an organic polymer component and an inorganic sol component, drying and then heat treating the precursor to convert the precursor into a conductive metal oxide. Polymer composition having properties. 2. The conductive metal oxide precursor is a salt of tin, indium, copper, zinc, titanium, vanadium, bismuth, iron, scandium, yttrium, lanthanum, neodymium, samarium, europium, terbium, ytterbium or lutetium, or The polymer composition according to claim 1, which is at least one kind of a complex compound. 3. The polymer composition according to claim 1, wherein the organic polymer component is a cellulosic polymer. 4. The polymer composition according to claim 1, wherein the inorganic sol component is at least one of silica sol, alumina sol, barium titanate sol and aluminum phosphate sol. 5. The polymer composition according to claim 1, wherein the atmosphere for the heat treatment is an oxidizing atmosphere. 6. The polymer composition according to claim 1, which is in the form of a film. 7. A conductive metal oxide precursor is dissolved in a solution containing an organic polymer component and an inorganic sol component, dried, and then heat treated to convert the precursor to a conductive metal oxide. A method for producing a polymer composition having electrical conductivity, comprising: