JPS61218641A - Porous organic semiconductor - Google Patents

Abstract

PURPOSE:To provide a porous organic semiconductor consisting of a heat-treated product of an aromatic condensation polymer having a specific polyacene skeleton and large specific surface area and enabling the rapid and uniform doping of a dopant having large ionic radius. CONSTITUTION:A condensation product obtained by the condensation of an aromatic hydrocarbon compound having phenolic hydroxyl group and an aldehyde is heat-treated to obtain a porous semiconductor having a polyacene skeleton structure with a C/H atomic ratio of 0.6-0.05 and a specific surface area of >=600m<2>/g by BET process and containing interconnected pores having average diameter of <=10mum. The objective porous hardened condensation product having large specific surface area can be produced by pouring an aqueous solution containing a precondensate and an inorganic salt such as zinc chloride into a mold, heating the solution while suppressing the evaporation of water to obtain a hardened product having three-dimensional network structure, heat- treating at 400-600 deg.C in nonoxidizing atmosphere, and washing the heat-treated product with water or dilute hydrochloric acid to remove the inorganic salt.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to porous organic semiconductors. More specifically, the present invention relates to a porous organic semiconductor that is a heat-treated product of an aromatic condensation polymer that is a condensation product of an aromatic hydrocarbon compound having a phenolic hydroxyl group and an aldehyde.

[Conventional technology]

Polymer materials are excellent in moldability, light weight, and mass production. Therefore, by taking advantage of these properties of polymer materials, organic polymer materials that have electrical semiconductivity are desired in many industrial fields including the electronics industry. Early organic semiconductors were difficult to form into films or plates, and they did not have the properties of 9- or p-type impurity semiconductors, so their uses were limited. In recent years, organic semiconductors with relatively excellent formability have become available, and by doping these semiconductors with electron-donating or electron-accepting dopants, they can be made into n-type or p-type organic semiconductors. It became possible to do so. Polyacetylene is a typical example of such an organic semiconductor. This organic semiconductor has an electrical conductivity of about 1 O-I (Ω・-″), and ρ
However, by doping with an electron-accepting dopant such as 12, A''I+ or an electron-donating dopant such as Li or Nα, the electrical conductivity can be greatly improved; A conductivity of 1 was obtained.

However, polyacetylene has the disadvantage of being easily oxidized by oxygen. For this reason, it is difficult to handle in the air, and it lacks practicality as an industrial material.

In addition, Japanese Patent Application Laid-open No. 58-1 filed by the same applicant as the present application
No. 36,649 discloses (B) a heat-treated product of aromatic condensation consisting of carbon, hydrogen and oxygen, je 17 mer, with a polyacene skeleton structure having an atomic ratio of hydrogen atoms/carbon atoms of α60 to α15; an insoluble and infusible substrate containing (
B) An electrically conductive organic polymeric material is disclosed which is comprised of an electron-donating doping agent or an electron-accepting doping agent and has a higher electrical conductivity than an undoped cough substrate. The above-mentioned insoluble and infusible substrate has excellent heat resistance and oxidation resistance, and can be doped with an electron-donating doping agent or an electron-accepting doping agent as described above, and exhibits pm or h-type properties. Gives an organic semiconductor. However, the above-mentioned publication does not describe anything about porous substrates or porous organic semiconductors.

Also, please refer to the earlier patent application filed in 1973 filed by the same applicant as the present application.
No. 9-8152 has not yet been published, but in the same earlier application, (a) a heat-treated product of an aromatic condensation polymer consisting of carbon, hydrogen and oxygen, with an atomic ratio of hydrogen atoms/carbon atoms of α60 to Is it α15 and the specific surface area value by BET method is 600? (c) an electron-donating doping agent or an electron-accepting doping agent; (q) an undoped substrate having an electrical conductivity of Electrically conductive organic polymeric materials have been proposed that are characterized by being more flexible than the substrate.

This organic polymer material has a specific surface area value of /,QQm”71
Because of the above, even doping agents LIdCIO,-, BF4-, etc. having a relatively large ionic radius can be doped smoothly. However, the specification of this prior application does not mention anything about porous substrates or porous organic semiconductors.

On the other hand, ceramic porous bodies and carbon porous bodies are known as porous bodies having communicating pores with excellent heat resistance and chemical resistance, and are used in many industrial fields including F materials.

However, in today's era of biotechnology, organic semiconductors with excellent heat resistance, chemical resistance, porousness, and large specific surface area are in great social need.
Not yet developed.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a porous organic semiconductor.

Another object of the present invention is to provide a porous organic semiconductor having excellent heat resistance and oxidation resistance.

Still another object of the present invention is to provide an organic semiconductor having a large number of communicating pores that can be rapidly and uniformly doped with an electron-accepting dopant and/or an electron-donating dopant having a relatively large ionic radius. There is a particular thing.

Still another object of the present invention is to provide an organic semiconductor doped with an electron-donating dopant and/or an electron-accepting dopant.

Yet another object of the present invention is to provide a porous organic semiconductor in the form of a film, plate, or the like.

Still another object of the present invention is to provide an organic semiconductor having fine communicating pores that is susceptible to various chemical reactions or physical adsorption.

Further objects and advantages of the present invention will become apparent from the description below.

[Means and effects for solving the problems] According to the present invention, the above-mentioned objects and advantages of the present invention are achieved by the following: A heat-treated polymer, which (a) has a polyacene skeleton structure with a hydrogen atom/carbon atom atomic ratio of α6 to α05, and (c) has a specific surface area value of at least 600 m”7 g by the BET method. Ashi,
and (c) achieved by a porous organic semiconductor characterized by having communicating pores with an average pore diameter of 10 μm or less.

The aromatic condensation polymer in the present invention is a condensate of an aromatic hydrocarbon compound having a phenolic hydroxyl group and an aldehyde. Such aromatic hydrocarbon compounds include, for example, phenol, methylene-bisphenols represented by the following formula, where 2 and V are each independently 0.1 or 2; Alternatively, it can also be hydroxy-biphenyls or hydroxynaphthalenes. Among these,
Practically speaking, phenols, especially phenol, are preferred.

The aromatic condensation polymer in the present invention further includes one of aromatic hydrocarbon compounds having a phenolic hydroxyl group.
Use of a modified aromatic polymer in which part of the polymer is substituted with an aromatic hydrocarbon compound having no phenolic hydroxyl group, such as xylene, toluene, etc., or a modified aromatic polymer that is a 3e 17 mer, such as a condensate of phenol, xylene, and formaldehyde. You can also do it.

In addition to formaldehyde, aldehydes include
Formaldehyde is preferred, although other aldehydes such as acetaldehyde and furfural can also be used. The phenol-formaldehyde condensate may be of the Nogalac type, resol type, or a composite thereof.

The porous organic semiconductor of 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 initial condensate of an aromatic hydrocarbon compound having a phenolic hydroxyl group or an aromatic hydrocarbon compound having a phenolic hydroxyl group and an aromatic hydrocarbon compound having no phenolic hydroxyl group and aldehydes is prepared, and this initial condensate and Prepare a water bath solution containing an inorganic salt, pour this water bath solution into a suitable mold, and then heat the water bath solution while suppressing the evaporation of water to mold it into, for example, a plate shape, a film shape, or a cylindrical shape. The cured body is then heat-treated by heating to a temperature of 350 to 800°C in a non-oxidizing atmosphere, and the resulting heat-treated body is then washed to remove the inorganic salts contained in the heat-treated body. remove.

The above-mentioned inorganic salt used together with the initial condensate is a pore-forming agent that is removed in a later step and used to provide communicating pores to the cured product, such as zinc chloride, sodium phosphate, potassium hydroxide, or potassium sulfide. . Among these, zinc chloride is particularly preferably used. The inorganic salt can be used in an amount of, for example, 25 to 10 times the weight of the initial condensate. If the amount is less than the lower limit, it is difficult to obtain a porous body having communicating pores, and if the amount is more than the upper limit, the mechanical strength of the finally obtained porous body tends to decrease, which is not desirable. The aqueous solution of the initial condensate and the inorganic salt can be prepared using, for example, water in an amount α1 to 1 times the weight of the inorganic salt, although it varies depending on the type of inorganic salt used. Thus, for example 10G,
An aqueous solution having a viscosity of 000 to 100 poise is poured into a suitable mold and heated to a temperature of, for example, 50 to 200°C.

During this heating, it is important to suppress evaporation of water in the aqueous solution. That is, it is considered that the initial metal feed in the aqueous solution is heated and gradually hardens, and grows into a three-dimensional network structure while separating from zinc chloride and water.

The thus obtained cured product is then heated in a non-oxidizing atmosphere (including a vacuum state) at a temperature of 350 to 800°C, preferably 350 to 700°C, particularly preferably 400 to 600°C.
It is heated to a temperature of 00°C and heat treated.

The preferred rate of temperature increase during heat treatment varies somewhat depending on the degree of aromatic condensation/IJ mother used or its hardening geography, its shape, etc., but generally it is 300°C from room temperature.
It is possible to raise the temperature at a relatively high rate up to a temperature of about m, for example, at a rate of 100° C./hour. When the temperature exceeds 300°C, thermal decomposition of the aromatic condensation polymer begins and gases such as water vapor (CEtO), hydrogen, methane, and carbon oxide begin to be generated.
It is advantageous to raise the temperature at a sufficiently slow rate.

Such heating and heat treatment of the aromatic condensation polymer is performed in a non-oxidizing atmosphere. Examples of the non-oxidizing atmosphere include nitrogen, alpine, helium, neon, carbon dioxide, etc. Nitrogen is preferably used. Such a non-oxidizing atmosphere may be stationary or flowing.

By thoroughly washing the obtained heat-treated body with water or diluted hydrochloric acid, the inorganic salts contained in the heat-treated body can be removed, and when it is then dried, it becomes porous with developed communicating pores and a large specific surface area. A cured condensate can be obtained.

Thus, by the above heating and heat treatment, the atomic ratio of hydrogen atoms/carbon atoms (hereinafter referred to as H2O ratio) becomes 06 to C1,0.
5. The porous organic semiconductor of the present invention, which preferably has a polyacene skeleton structure of 0.5 to 0.15 and has communicating pores with an average pore diameter of 10 μm or less, for example, an average pore diameter Q of 03 to 10 μm. is obtained. The porous organic semiconductor of the present invention is insoluble and infusible. Further, the atomic ratio of oxygen atoms/carbon atoms (0/C ratio) is usually 1106 or less, preferably 0.
03 or less. Also, according to X-ray diffraction (C1LK-), the position of the main peak is expressed in 2θ and is 2 (15 to 2
55°, and in addition to the main peak, 41°
There is a broad other between ~46°. Also, according to the infrared absorption spectrum, D (=D too
The absorbance ratio of 0~2940/Dtsao z 1640 is usually 0.5 or less, preferably 0.5 or less.

That is, it is understood that the above-mentioned insoluble and infusible substrate is one in which the polycyclic structure of polyacene-based benzene is evenly and appropriately developed between polyacene-based molecules.

According to the present invention, there is also provided a porous organic semiconductor in which the insoluble and infusible substrate is doped with an electron-donating dopant, an electron-accepting dopant, or both of these dopants.

That is, according to the present invention, (A) a heat-treated product of an aromatic condensation polymer which is a condensation product of an aromatic hydrocarbon compound having a phenolic hydroxyl group and an aldehyde, wherein (a) hydrogen atoms/carbon atoms It has a polyacene skeleton structure with an atomic ratio of 0.6 to 0.05, and has a specific surface area value of at least 60
0m''/(J), and (c) a porous, bath-infusible substrate having communicating pores with an average pore diameter of 10 μm or less, and (8) an electron-donating dopant and/or an electron-accepting dopant. A porous organic semiconductor device is provided.

1. A substance that easily releases electrons is used as the electron-donating dopant. For example, metals from group 1A of the periodic table, such as lithium, sodium, potassium, dium or cesium, are preferably used.

Similarly, tetra(0
1-C4 alkyl) ammonium cations such as (CH
s) 4ff+ or ((:', fJaN+ can be used.

Further, as the electron-accepting dopant, a substance that easily accepts electrons is used. For example, fluorine, chlorine, bromine, iodine]・mouth; AaF, , PF,, BF*,
BCl3, BBr3, Fact, tv-like ha=f f
SO, or oxides of nonmetallic elements such as N, O, or H, 504, HNO3, or HC1
Anions derived from inorganic acids such as 0.0, etc. are preferably used.

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

For example, when the dopant is an alkali metal, the dopant can be doped by contacting the insoluble and infusible substrate with a molten alkali metal or vapor of the alkali metal, or with an alkali metal naphthalene complex formed in, for example, tetrahydrofuran. Doping can also be carried out by contacting an insoluble and infusible substrate.

The dopant is a halodan compound! , b or oxides of nonmetallic elements, doping can be easily carried out by bringing these gases into contact with an insoluble and infusible substrate.

When the doping agent is an anion derived from an inorganic acid, the doping can be carried out by directly coating or impregnating the insoluble and infusible substrate with the inorganic acid.

It is also possible to set the insoluble and infusible substrate as an electrode and electrochemically dope it with an electron-donating dopant such as lithium or sodium or an electron-accepting dopant such as CtO4'''' or BF4''''. It is.

As described above, since the insoluble and infusible substrate of the present invention is a porous body having communicating pores, it facilitates the diffusion of the dopant in the gaseous dopant or bath liquid as described above, and enables rapid and uniform doping. It has the great advantage of being possible.

Furthermore, since the insoluble and infusible substrate of the present invention has a large specific surface area value determined by the EET method, 0104'', BF;, AsF5''''
It also has the advantage of being able to dope smoothly and uniformly even dopants with large ionic radii such as.

The doping agent is generally used so that it is present in the obtained organic semiconductor of the present invention in a ratio of 10 -1 mol or more to the repeating unit of the aromatic condensation polymer.

The organic semiconductor of the present invention thus obtained has an electrical conductivity of the insoluble and infusible substrate before doping (for example, 1O-It to 1
01Ω″″1 ・Uniformity 1) Higher electrical conductivity than 11
For example, the thickness of the insoluble and infusible substrate before doping increases several to 1010 times. When doped with an electron-donating dopant, an n-type semiconductor is provided, and when doped with an electron-accepting dopant, a p-producing conductor is provided. According to the invention, it is also possible to use electron-donating and electron-accepting dopants together as dopants.

When these dopants are almost uniformly mixed in the porous organic semiconductor of the present invention, the porous organic semiconductor of the present invention becomes p-type or nfJl depending on which one of the dopants is more present. For example, if there are many electron-donating dopants, it will be n-type, and if there are many electron-accepting dopants, it will be p-type.
m.

[Action/effect of the invention]

The porous organic semiconductor of the present invention has excellent heat resistance and oxidation resistance, and can be formed into any shape such as a film, a plate, or a cylinder, making it a highly practical material.

In the porous organic semiconductor of the present invention, the insoluble and infusible substrate having a polyacene skeleton structure has a three-dimensional network structure through communicating pores, so that fluid can freely enter and exit fine details through the communicating pores. easy. The average pore diameter of the communicating pores is as fine as 10 μm or less, and the porous body has uniform pore diameters, that is, a sharp pore diameter distribution. In addition, it is possible to obtain porous bodies with an average pore diameter of about 10 μm, ranging from extremely fine porous bodies with an average pore diameter of 0.1 μm, so it is possible to use them depending on the purpose.

The specific surface area value of the organic semiconductor of the present invention by the BET method is 60
0m"71 or more. If it is less than 600"/y, it is difficult to smoothly dope be/cents with large ion radius such as C104-1BF, -1A a FS, etc., and as shown later, active adsorption When used as a material, the amount of adsorption decreases, which is undesirable.

It is also possible to rapidly proceed with various chemical reactions occurring at the interface by utilizing the fine interconnected pores and high specific surface area of the porous organic semiconductor of the present invention. For example, it is suitable for use as an electrode material for batteries, etc. Also, various physical adsorptions occur smoothly, uniformly, and in large quantities, so it is suitable as an adsorbent or a separation material.

Furthermore, adsorption of gases such as H, 0, 0, etc. causes a slight change in electrical conductivity, so it can be suitably used as a sensor material.

The apparent density of the porous organic semiconductor of the present invention is usually α2~
α6g/1M1''.In other words, the porous organic semiconductor of the present invention ranges from porous bodies with high porosity to porous bodies with relatively low porosity.The mechanical strength of porous bodies is determined by the apparent density. For example, the porous material of the present invention with a strength of 0.2 g/cys" has sufficient strength for practical use. Furthermore, since the porous organic semiconductor of the present invention is composed of an insoluble and infusible substrate with a polyacene skeleton structure, it has excellent chemical resistance, and has fine interconnected pores, so it can withstand harsh conditions. It is also suitable as a furnace material for use in.

As described above, the porous organic semiconductor of the present invention has excellent heat resistance and oxidation resistance, and has fine interconnected pores, so it can be quickly and uniformly doped with an electron-accepting or electron-donating dopant. It is an industrially useful material that can be applied in many fields because it has a chemically active function and can take any shape such as a film or plate with excellent mechanical strength.

In addition, in this specification, the average pore diameter of the communicating pores is measured and defined as follows.

An electron micrograph is taken of the sample at a magnification of, for example, 1000 to 10,000 times. Draw any straight line on this photo,
If the number of pores intersecting the straight line is n, then the average pore diameter (d
) is calculated using the following formula.

Here, Li is the length cut by the hole where the straight lines intersect.1. Σit is the sum of the cut lengths of n holes with s=1, and `` is the number of holes that intersect the straight line, provided that n takes a value of 10 or more.

Example 1 (1) An aqueous solution containing water-soluble resol (approximately 60% concentration)/zinc chloride/water mixed in a weight ratio of 10/25/4 was formed into a film on a glass plate using a film applicator. Next, a glass plate was placed over the water bath liquid formed into the film, and the film was cured by heating at a temperature of about 100° C. for 1 hour to prevent moisture from evaporating.

The phenolic resin film was placed in a siliconite electric furnace and heated at a rate of 40°C/hour under a nitrogen stream to a temperature of 450°C.
Heat treatment was performed to ℃. Next, the heat-treated product was washed with dilute hydrochloric acid, then water, and then dried to obtain a film-like porous body. The thickness of the film is about 200 μm, and the apparent density is about 0.55 y/crm, making it a film with excellent mechanical strength.Next, the electrical conductivity of the film was measured at room temperature using four DC terminals. When measured by method, 1O-
7 (Ω・crn)″1. Elemental analysis also showed that the atomic ratio of hydrogen atoms/carbon atoms was 0.35. The shape of the peak from X-ray diffraction was due to the polyacene skeleton structure. There is a broad main peak around 20-22℃ at 2θ, and 41-4/16
'A small peak was confirmed nearby.

In addition, when we measured the specific surface area value using the BET method, 2
, 100 m''/σ, which was an extremely large value.

Next, in order to observe the state of pores in the film-like semiconductor, an electron micrograph of a cross section of the film was taken.

Shown in Figure 1. As is clear from the figure, it was a porous body with a three-dimensional network structure and fine interconnected pores of 10 μm or less in size.

(2) Next, a tetrahydro7 run solution of sodium naphthalate was prepared using dehydrated tetrahydrofuran, naphthalene, and metallic sodium.

The film semiconductor described above was immersed in this solution in a dry atmosphere and doped at room temperature for about 1 hour. Thereafter, the body was washed with dehydrated tetrahydrofuran, and after death, it was dried under reduced pressure for about 10 hours. The electrical conductivity of the dry sample is approximately 1
0′″m (Ω・aIM)″1.

Examples 2 to 4 (1) A phenol resin film with a thickness of about 200 μm obtained in the same manner as in Example 1 was heated at a rate of about 0° C./hour under a nitrogen stream in a siliconite electric furnace, and the temperature was as shown in Table 1. Heat treatment was performed by heating to various predetermined temperatures shown. Thereafter, it was washed with dilute hydrochloric acid and water and dried to obtain a porous semiconductive film. The obtained porous semiconductor film was subjected to elemental analysis, electrical conductivity, and measurement of specific surface area by BET method. The results are summarized in Table 1.

(2) Next, add L to the sufficiently dehydrated propylene carnate.
tC104 was roughly understood to be a bath liquid with a concentration of about 1.0 mol/l. Then, with lithium metal used as a cathode, the above solution used as an electrolyte, and a porous semiconductive film used as an anode, a voltage of about 4 V was applied between the two electrodes, and CLO4'' ions were doped for about 1 hour.The amount of doping was It is expressed as the number of CLO4'' ions per carbon atom in the semiconductor film. In the present invention, the number of C t O,'' ions is determined based on the current value flowing through the circuit during doping. After washing the film with A7Ton and drying it under reduced pressure, the electrical conductivity was measured.The results are as follows.
Shown in the table.

The porous semiconductor of the present invention has a structure with fine communicating pores, and has an extremely high specific surface area value measured by the BET method.
CtO4- ions with a large ionic radius could be doped smoothly in a short time.

[Brief explanation of the drawing]

FIG. 1 is an electron micrograph of a cross section of the porous organic semiconductor film of the present invention. The length of the bar shown at the bottom right of the photo is 5μ. Written amendment to procedures for one person (flag) July 25, 1985

Claims (1)

[Scope of Claims] 1. A heat-treated product of an aromatic condensation polymer which is a condensation product of an aromatic hydrocarbon compound having a phenolic hydroxyl group and an aldehyde, comprising: (a) an atomic ratio of hydrogen atoms/carbon atoms; is 0.6 to 0.05
(b) has a specific surface area value of at least 600 m^ by the BET method;
2/g, and (c) having communicating pores with an average pore diameter of 10 μm or less. 2. The porous organic semiconductor according to claim 1, wherein the aromatic condensation polymer is a condensate of phenol and formaldehyde. 3. The porous organic semiconductor according to claim 1, wherein the atomic ratio of hydrogen atoms/carbon atoms is 0.5 to 0.15. 4.Specific surface area value by BET method is 800-3.000m
The porous organic semiconductor according to claim 1, which has a ^2/g. 5. The porous organic semiconductor according to claim 1, which has a large number of communicating pores with an average pore diameter of 0.03 to 10 μm. 6. The atomic ratio of oxygen atom (O)/carbon atom (C) is 0.0
The porous organic semiconductor according to claim 1, having a polyacene skeleton structure of 6 or less. 7. The porous organic semiconductor according to claim 1, wherein the heat-treated product exhibits a three-dimensional network structure through a large number of communicating pores. 8. The porous organic semiconductor according to claim 1, wherein the porous organic semiconductor is a film, plate, fiber, or a composite thereof. 9. (A) A heat-treated product of an aromatic condensation polymer which is a condensation product of an aromatic hydrocarbon compound having a phenolic hydroxyl group and an aldehyde, wherein (a) the atomic ratio of hydrogen atoms/carbon atoms is 0. 6 to 0.05, (b) the specific surface area value by BET method is at least 600 m^2/g, and (c) the average pore size is 10 μ
A porous organic semiconductor characterized by comprising a porous insoluble and infusible substrate having communicating pores of m or less, and (B) an electron-donating dopant and/or an electron-accepting dopant. 10. The porous organic semiconductor according to claim 9, which exhibits electrical conductivity greater than that of the porous insoluble and infusible substrate (A). 11. The electron-donating dopant is lithium, sodium,
10. The porous organic semiconductor according to claim 9, which is a Group 1A metal including potassium, rubidium and cesium. 12. The electron-donating dopant is tetra(C_1~C_■
The porous organic semiconductor according to claim 9, which is a lower alkyl) ammonium cation. 13. The electron-accepting dopant is AsF_5, PF_5,
The porous organic semiconductor according to claim 9, which is a halide such as BF_3, BCl_3, BBr_3, FeCl_3. 14. The porous organic semiconductor according to claim 9, wherein the electron-accepting dopant is a halogen such as fluorine, chlorine, bromine, or iodine. 15. Electron accepting dopant is SO_3 or N_2
oxides of non-metallic elements such as O_5 or H_2SO_4,
The porous organic semiconductor according to claim 9, which is an anion derived from an inorganic acid such as BNO_3 or BClO_4.