JPH0819217B2 - Electrically conductive organic polymer powder material and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrically conductive polymer-based powder material, and more specifically, it is a pulverized product of a heat-treated aromatic polymer having a polyacene-based skeleton structure. The present invention relates to an electrically conductive organic polymer-based powder material and a method for producing the same.

[Conventional technology]

Polymer materials are excellent in moldability, light weight and mass productivity. Therefore, by utilizing these characteristics of the polymer material, an organic polymer material having electrical semiconductivity is desired in many industrial fields including the electronics industry. The early organic semiconductors were difficult to form into a film or plate, and did not have the property as an n-type or p-type impurity semiconductor, so that they were limited in use. In recent years, organic semiconductors having relatively excellent moldability have been obtained, and it is possible to obtain an n-type or p-type organic semiconductor by doping these semiconductors with an electron-donating dopant or an electron-accepting dopant. Became. Polyacetylene is a typical example of such an organic semiconductor.

However, polyacetylene has a drawback that it is easily oxidized by oxygen. Therefore, it is difficult to handle in air, and it is not practical as an industrial material.

Japanese Patent Application Laid-Open No. 59-3806, filed by the applicant of the present application, discloses (A) a heat-treated product of an aromatic condensation polymer composed of carbon, hydrogen and oxygen, which has a hydrogen atom / carbon atom atomic ratio. The insoluble and infusible substrate having a polyacene skeleton structure represented by 0.60 to 0.15, and (B) an electron donating doping agent or an electron accepting doping agent, and (C) the electrical conductivity undoped substrate An electrically conductive organic polymer material characterized by being larger than the above has been proposed.

The material is stable in air and is practical as an industrial material. However, even in this prior application, when an organic polymer material composed of an insoluble and infusible substrate having a polyacene-based skeleton structure is formed into a plate-shaped, cylindrical, or other shaped body, there is a problem in dimensional stability during heat treatment, It is difficult to obtain a dimensional material, and when trying to obtain a large-sized molded product,
There remains a problem that cracks and the like occur during heat treatment.

On the other hand, molding a powder body in various fields such as ceramic materials and carbon materials to obtain a product with a desired shape is
It is known as a general method, and there is a great need for powders having excellent moldability and high performance.

However, an insoluble and infusible substrate containing a polyacene-based skeleton structure which has high performance, in particular, a large amount of dopant can be rapidly doped, and which is excellent in moldability has not yet been developed.

[Problems to be Solved by the Invention]

The present inventors have completed the present invention by finding that the above-mentioned problems can be solved by pulverizing an insoluble and infusible substrate containing a polyacene-based skeleton structure into a powder.

An object of the present invention is to provide an electrically conductive organic polymer powder material having semiconductivity or electric conductivity of a conductor and excellent in moldability, and a method for producing the same.

Another object of the present invention is an insoluble infusible substrate powder material having a polyacene-based skeleton structure in which a conjugated system between carbon atoms is developed, and the specific surface area value by the BET method is 1500 m ² / g or more,
An object of the present invention is to provide an electrically conductive organic polymer-based powder material that can be rapidly and heavily doped with a dopant.

Still another object of the present invention is easy to manufacture and economical,
Moreover, it is an object of the present invention to provide an insoluble and infusible base powder having a polyacene skeleton structure which can be formed into an arbitrary shape such as a film shape or a plate shape.

Still other objects and effects will be apparent from the following description.

[Means for solving the problem]

According to the present invention, the above object and advantages of the present invention are a heat-treated product of an aromatic condensation polymer composed of carbon, hydrogen and oxygen, wherein the atomic ratio of hydrogen atoms / carbon atoms is 0.6 to.
An insoluble and infusible base powder containing a polyacene-based skeleton structure of 0.05, a specific surface area value by the BET method of at least 1500 m ² / g, and an average particle diameter of 5.0 to 0.1 μm. A heat-treated product of an electrically conductive organic polymer powder material and an aromatic condensation polymer composed of carbon, hydrogen and oxygen, wherein the atomic ratio of hydrogen atom / carbon atom is 0.
An insoluble and infusible substrate containing a polyacene skeleton structure of 6 to 0.05 is crushed using a crushing means having a Knoop hardness of 100 or less on the working surface, and a specific surface area value by the BET method of at least 150.
This is achieved by a method for producing an electrically conductive organic polymer-based powder material, which is 0 m ² / g and has an average particle size of 5.0 to 0.1 μm.

The insoluble and infusible substrate having a polyacene skeleton structure can be obtained by heat-treating an aromatic condensation polymer described in JP-A-59-3806 under specific conditions.

Specifically, the aromatic condensation polymer used in the present invention is a condensation product of an aldehyde with an aromatic hydrocarbon compound having a phenolic hydroxyl group such as a phenol / formaldehyde resin, a xylene-modified phenol / formaldehyde resin (part of phenol). Are substituted with xylene), aromatic hydrocarbon compounds having a phenolic hydroxyl group, aromatic hydrocarbon compounds having no phenolic hydroxyl group and condensates of aldehydes, and furan resins are preferable.

The insoluble and infusible substrate in the present invention is a heat-treated product of the aromatic condensation polymer as described above and can be produced, for example, as follows.

An inorganic salt such as zinc chloride or sodium phosphate is mixed with the aromatic condensation polymer described above. This makes it possible to impart porosity to the insoluble and infusible substrate. The amount to be mixed varies depending on the type of the inorganic salt and the shape and performance of the target electrode, but is preferably 10/1 to 1/7 by weight. Also,
In the case of obtaining a substrate which is porous and has communicating holes,
It is preferable to use the inorganic salt in an amount of 2.5 to 10 times by weight the amount of the aromatic condensation polymer. The mixture of the inorganic salt and the aromatic condensation polymer obtained in this way is formed into a desired shape such as a film or a plate, and cured by heating at a temperature of 50 to 180 ° C for 2 to 90 minutes. To do.

The thus obtained cured product is then heated in a non-oxidizing atmosphere to a temperature of 400 to 800 ° C, preferably 450 to 750 ° C, particularly preferably 500 to 700 ° C. By this heat treatment, the aromatic condensation polymer undergoes a dehydrogenation dehydration reaction, and a polyacene skeleton structure is formed by the condensation reaction of the aromatic ring.

This reaction is a type of thermal condensation polymerization, and the degree of reaction is represented by the atomic number ratio of hydrogen atoms / carbon atoms (hereinafter referred to as H / C) in the final product. The H / C value of the insoluble and infusible substrate is 0.05 to 0.6, preferably 0.15 to 0.50. If the H / C value of the insoluble and infusible substrate is larger than 0.6, the polyacene skeleton structure is undeveloped and the electrical conductivity is low, which is not preferable. On the other hand, when the H / C value is less than 0.05, the amount of dopant that can be doped is small, which is not preferable.

The heat-treated body thus obtained is thoroughly washed with water, diluted hydrochloric acid or the like to remove the inorganic salt contained in the heat-treated body.

Then, when this is dried, an insoluble and infusible substrate is obtained.

Next, the insoluble infusible substrate powder of the present invention can be obtained by pulverizing the insoluble infusible substrate. As a matter of course, in order to obtain the insoluble and infusible base powder of the present invention,
The insoluble and infusible substrate before grinding has a specific surface area value of 150 according to the BET method.
It must be 0 m ² / g or more.

The powder material of the present invention is produced by crushing the insoluble and infusible substrate. At this time, if the pores existing in the insoluble and infusible substrate are broken, the specific surface area is significantly reduced, so it is extremely important to pulverize the pores without breaking them. With respect to this point, various investigations have revealed that the impact force during crushing greatly contributes to the fact that the Knoop hardness of the working surface for the insoluble and infusible substrate is 100 or less and pulverization means that pore breakage is unlikely to occur. I got the knowledge of. The crushing means may be appropriately selected from well-known crushing means such as a ball mill, a vibration mill, a jet mill, a kneader, etc., but as described above, the Knoop hardness of the working surface for the insoluble and infusible substrate is 10
When 0 or less is used, preferable results are obtained. Examples of materials having a Knoop hardness of 100 or less include synthetic resins such as polyethylene resin, phenol resin, polyurethane and nylon. It is preferable to form the working surface of the crushing means with these materials. As a pulverizing means suitable for the above conditions, there is a ball mill in which all the balls or at least the co-surface layer portion is formed of nylon and a ball mill in which all or at least the co-inner layer portion is formed of nylon. In the case of crushing with this nylon ball mill, it is possible to crush to a target particle size with a weak impact without lowering the specific surface area value of the insoluble infusible substrate, and to obtain the insoluble infusible substrate powder of the present invention. it can. If the material of the crusher has a hardness of more than Hk = 100, the crushing force will be large and the pores will be crushed, and the specific surface area value will decrease. That is, when a crusher having a working surface formed of a material having a low hardness of Hk = 100 or less is selected, it is crushed to a particle size aimed at by the present invention without weakening the impact force and lowering the specific surface value. Can be achieved with favorable results.

Here, the Knoop hardness (Hk) is a diamond indenter with a special shape such that the indentation becomes a rhombus.
(°) is used to measure the length of the diagonal line of the indentation in the longitudinal direction (kg / mm ² ).

The insoluble and infusible base powder of the present invention has a specific surface area value by the BET method of at least 1500 m ² / g.

When the specific surface area value of the powder is less than 1500 m ² / g, a part or all of the pores are broken by pulverization, and
ClO ^- _4, BF ^- _4, when used as AsF difficult to dope the large dopant large quantities and smoothly ionic radius, such as _5, also active adsorbent as shown later, undesirably reduces the amount of adsorption.

Further, the average particle size of the powder is 5 μm to 0.1 μm, particularly preferably 2 μm to 0.1 μm. When the average particle size is larger than the upper limit, it is difficult to obtain practically sufficient strength when forming a molded product using the powder, and when the average particle size is smaller than the lower limit, grinding efficiency,
Not practical in terms of grinding time.

Since the insoluble infusible substrate powder having the polyacene skeleton structure shows a very large specific surface area value of 1500 m ² / g or more by the BET method, it is considered that gas such as oxygen penetrates and easily deteriorates. Actually, even if left in the air for a long time, there is no change in physical properties and the like, and it is excellent in oxidation stability.

According to the present invention, there is provided an electrically conductive organic polymer powder material obtained by doping the insoluble and infusible substrate powder with an electron donating dopant, an electron accepting dopant, or both of these dopants.

That is, according to the present invention, a heat-treated product of an aromatic condensation polymer composed of carbon, hydrogen and oxygen, which contains a polyacene skeleton structure having an atomic ratio of hydrogen atoms / carbon atoms of 0.6 to 0.05, is insoluble and infusible. Base powder and BE
A powder having a specific surface area value by the T method of at least 1500 m ² / g and an average particle size of 5.0 to 0.1 μm, and (B) an electrically conductive organic compound comprising an electron donating dopant and / or an electron accepting dopant. A molecular powder material is provided.

As the electron donating dopant, a substance that easily releases electrons is used. For example, lithium, sodium, potassium,
A Group 1A metal of the periodic table such as rubidium or cesium is preferably used.

Similarly, as the electron donating dopant, tetra (C ₁
-C ₄ alkyl) ammonium cation example (CH _{3) 4} N ⁺
Alternatively, (C ₄ H ₉ ) ₄ N ⁺ can be used.

A substance that easily accepts electrons is used as the electron-accepting dopant. For example, halogen such as fluorine, chlorine, bromine, iodine; halogen compound such as AsF ₅ , PF ₅ , BF ₃ , BCl ₃ , BBr ₃ , FeCl ₃ ; oxide of non-metal element such as SO ₃ or N ₂ O ₅ ; Alternatively, anions derived from an inorganic acid such as H ₂ SO ₄ , HNO ₃ or HClO ₄ are preferably used.

As the doping method of such a dopant, essentially the same doping method as that conventionally used for polyacetylene or polyphenylene can be used.

For example, when the dopant is an alkali metal, it can be doped by bringing molten alkali metal or vapor of alkali metal and insoluble infusible substrate powder into contact with each other, and, for example, an alkali metal naphthalene complex produced in tetrahydrofuran. It is also possible to dope by bringing the insoluble and infusible substrate into contact with each other.

When the dopant is halogen, a halogen compound or an oxide of a non-metal element, the doping can be easily performed by bringing these gases into contact with the insoluble and infusible base powder.

In the case of an anion derived from the inorganic acid of the doping agent, it can be carried out by impregnating the insoluble infusible substrate powder with the inorganic acid.

Further, electrochemically an electrode by molding the insoluble and infusible base powder, lithium, electron donating dopant or ClO ₄ such as sodium ^-, BF ₄ ^- may be doped with such as an electron-accepting dopant .

The doping agent is generally used so as to be present in the insoluble and infusible substrate powder of the present invention in a ratio of 10 ⁻⁵ mol or more based on the repeating unit of the aromatic condensation polymer.

The electric conductivity of the insoluble infusible substrate powder of the present invention thus obtained is higher than the electric conductivity of the insoluble infusible substrate powder before doping (for example, 10 ⁻¹² to 10 ² Ω ⁻¹ · cm ⁻¹ ). It increases the electrical conductivity, for example, several times to 10 ¹⁰ times more than the insoluble and infusible substrate powder before doping. When doped with an electron donating dopant, it gives an n-type semiconductor, and when doped with an electron accepting dopant, it gives a p-type semiconductor. According to the present invention, an electron donating dopant and an electron accepting dopant can be used together as a dopant. When these dopants are mixed in the insoluble and infusible substrate powder of the present invention almost uniformly, either one of them is p-type or n-type depending on which dopant is most abundant. For example, when there are many electron-donating dopants, n
It becomes a p-type when there are many electron-accepting dopants.

〔The invention's effect〕

The insoluble and infusible base powder containing the polyacene skeleton structure of the present invention has excellent moldability and can be formed into any shape such as a film shape, a plate shape, and a cylindrical shape by a method of adding a binder. It is a highly practical material.

By utilizing the high specific surface area value of the insoluble and infusible substrate powder of the present invention, various chemical reactions occurring at the interface can be rapidly advanced. For example, it is suitable as an electrode material for batteries. Further, various kinds of physical adsorption occur smoothly, uniformly and in a large amount, so that it is suitable as an adsorbent or a separating material.

Further, since a slight change in electric conductivity occurs due to the adsorption of gases such as H ₂ O and O ₂ , it can be suitably used as a sensor material.

Further, the insoluble and infusible base powder of the present invention has a polyacene skeleton structure and thus has excellent chemical resistance, and moreover, since it has many pores, it is used under severe conditions by molding. It is also suitable as a filter medium.

As described above, the insoluble and infusible base powder of the present invention has heat resistance,
It is an organic semiconductor that can be doped with an electron-accepting or electron-donating dopant rapidly, in large quantities, and uniformly because it has excellent oxidation resistance and a high specific surface area, and it also has a chemically active function. Moreover, since it can be formed into an arbitrary shape such as a film or a plate having excellent mechanical strength, it is an industrially useful material that can be applied to various fields.

 Hereinafter, the present invention will be specifically described with reference to examples.

In the examples, the average particle size of the insoluble and infusible substrate is a value measured as follows. That is, the average particle size () is a 1000 to 10000 times electron microscopic photograph of the sample powder, an arbitrary direction of this photograph is determined, and the length (li) of the arbitrarily selected particle in that direction is measured. However, it is a value calculated by the following equation.

Example 1 (1) Method for producing an insoluble and infusible substrate having a polycene-based skeleton structure: an aqueous solution in which water-soluble resol (about 60% concentration) / zinc chloride / water is mixed at a weight ratio of 10/25/4. 100 mm x 100 mm x 2
After pouring it into a mold of mm to cover the glass plate so that the water content would not evaporate, it was heated at a temperature of about 100 ° C. for 1 hour to be cured.

The phenol resin was placed in a silicon knit electric furnace, heated under a nitrogen stream at a rate of 40 ° C./hour, and heat-treated to 500 ° C. Next, the heat-treated product was washed with dilute hydrochloric acid, washed with water, and then dried to obtain a plate-shaped insoluble infusible substrate.

When the specific surface area value of the insoluble and infusible substrate was measured by the BET method, it was 2300 m ² / g. Further, an elemental analysis showed that the atomic ratio of hydrogen atoms / carbon atoms was 0.24.

(2) The Knoop hardness Hk of the insoluble infusible substrate of (1) above
A nylon ball mill made of nylon of material No. 7 was pulverized to obtain an insoluble and infusible base powder having an average particle size of 2.0 μm. The specific surface area of the powder measured by the BET method was 2000 m ² / g (No. 1). Similarly, the insoluble infusible substrate powder having an average particle size of 1.0 μm can be crushed for a long time. Specific surface area by BET method is 1900m
It was ² / g (No. 2). Further crushing, average particle size
The specific surface area value at 0.5 μm was 1650 m ² / g (No. 3).

To 100 parts of the powders No. 1 to No. 3 mentioned above, 5 parts of polytetrafluoroethylene was added as a binder, and the mixture was sufficiently kneaded with a dairy bee and molded into a plate having a thickness of 1 mm with a biaxial roller. . The bulk density at this time was 0.5 g / cm ³ . The molded plate obtained at this time had sufficient strength in all of Nos. 1 to 3.

 The results are shown in Table 1.

(3) Next, to the fully dehydrated propylene carbonate
LiClO ₄ was dissolved to a solution of about 1.0 mol /. Then, using lithium metal as a cathode, the above solution as an electrolytic solution, and the plate-shaped molded body of (2) as an anode, a voltage of about 4 V was applied between both electrodes to dope ClO ₄ ions for about 1 hour.
The doping amount is represented by the number of ClO ₄ ⁻ ions per carbon atom of the insoluble and infusible substrate powder. In the present invention, the number of ClO ₄ ⁻ ions is obtained from the value of current flowing in the circuit during doping. The results are shown in Table 1. A doping amount of 2.8% to 3.1% is a good value because it brings out the performance of the electrode.

Comparative Example 1 (1) Knoop hardness was applied to the insoluble and infusible substrate of Example 1 (1).
It was pulverized with an alumina ball mill made of alumina with Hk = 2000 to obtain an insoluble and infusible base powder having an average particle size of 1 μm. The specific surface area of the powder measured by the BET method was 1200 m ² / g. As in Example 1, a Teflon binder was used to form a plate.

(2) Under the same conditions as in Example 1 (3), a propylene carbonate solution of LiClO ₄ 1.0 mol / electrolyte was used, lithium metal was used as a cathode, and the above-mentioned molded plate was used as an anode.
A voltage of 4 V was applied to dope ClO ₄ ⁻ ions for about 1 hour. The doping amount at this time was 2.2%, which was a low performance.

Comparative Example 2 The insoluble and infusible substrate of Example 1 was dairy bee (Hk> 100).
It was pulverized so that the average particle size was 30 μm. The specific surface area value of the powder by the BET method was 2300 m ² / g, and there was no decrease from the specific surface area value of the insoluble and infusible substrate. However, when it was molded using a Teflon binder, strength was not obtained and it was brittle.

 ─────────────────────────────────────────────────── ─── Continuation of front page Examiner Kunihiko Sato (56) References JP-A-58-136649 (JP, A) JP-A-59-3806 (JP, A)

Claims (2)

[Claims] 1. A heat-treated product of an aromatic condensation polymer composed of carbon, hydrogen and oxygen, wherein the insoluble infusible substrate contains a polyacene skeleton structure having an atomic ratio of hydrogen atoms / carbon atoms of 0.6 to 0.05. It is a powder, and the specific surface area value by the BET method is at least 1500 m ² / g, and the average particle size is 5.0 to
An electrically conductive organic polymer powder material characterized by having a thickness of 0.1 μm. 2. An insoluble, infusible substrate containing a heat-treated aromatic condensation polymer composed of carbon, hydrogen and oxygen, which contains a polyacene skeleton structure having an atomic ratio of hydrogen atoms / carbon atoms of 0.6 to 0.05. Is crushed using a crushing means having a Knoop hardness of 100 or less on the working surface, and the powder has a specific surface area value of at least 1500 m ² / g by the BET method and an average particle diameter of 5.0 to 0.1 μm. A method for producing an electrically conductive organic polymer powder material.