JPH08259810A - Electrically semiconductor resin sheet and its production - Google Patents

Abstract

PURPOSE: To obtain a special electrically semiconductive rein sheet having unique electrical conductivity, that is, having different surface resistivities between the obverse side and the reverse side, especially surface resistivity on one side at least 10 times that of the other side in spite that the material is homogeneous and to provide a method for producing such an electrically semiconductive resin sheet. CONSTITUTION: This resin sheet is obtained from a polymer blend consisting of a polyimide and a dope-state polyaniline. In this sheet, the surface resistivity of one side is at least 10 times that of the other side. This kind of electrically semiconductive resin sheet can be prepared preferably by casting a film-making solution on a substrate to form a layer of the solution on the substrate and subsequently heating the layer in a state tightly adhered to the substrate without peeling the layer from the substrate to imidate the polyamic acid and then peeling the formed resin sheet from the substrate to obtain the objective sheet. The film-making solution is obtained by compounding a polyamic acid, a polyaniline of a dedoped state and a dopant which can make the polyaniline electrically conductive by adding it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductive resin sheet having different surface resistivities on the front and back surfaces, and a method for producing the same. More specifically, it comprises a polymer blend of polyimide and doped polyaniline. The present invention relates to semiconductive resin sheets having different surface resistivities and a method for producing such a semiconductive resin sheet.

Such a semiconductive resin sheet having unique electrical properties is used, for example, in battery electrode materials, electromagnetic shield materials, electrostatic attraction films, antistatic materials, image forming apparatus parts, electronic devices, etc. It can be preferably used.

[0003]

2. Description of the Related Art Conventionally, it has been already known that a polyimide can be made conductive by blending it with a conductive filler such as carbon, carbon fiber, graphite, metal particles, metal oxide particles. There is. However, when these conductive fillers are blended with polyimide to form a conductive sheet, the resulting sheet has poor mechanical properties, and in particular, there is no "suppleness" in the sheet, and when the sheet is processed or In use, it is unable to withstand the tension applied to it, and there is a problem of cutting or breaking. Further, according to such a method, it is difficult to uniformly apply the required surface resistivity to the obtained polyimide sheet with good reproducibility.

Further, such a conductive material known in the prior art has a uniform resistance value in all parts of the material. On the other hand, by itself, for example, a semiconductive sheet having different surface resistivity on the front and back surfaces, that is, one surface has a low surface resistivity and the other surface has a high surface resistivity. The semiconductive sheet is useful as an image forming apparatus component, an electromagnetic shield material, an antistatic material, and the like, but a semiconductive sheet having different surface resistivities on the front and back surfaces is a conventional semiconductive sheet. It is manufactured by a method of vapor-depositing a metal on one surface or bonding two sheets having different surface resistivities. However, according to such a method, there are problems that the steps are complicated and that the sheet thus obtained has a surface having a discontinuous resistance value or material inside.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the conventional semiconductive sheet, and has a uniform surface material and different surface resistances on the front and back surfaces. And a semiconductive resin sheet having a specific conductivity such that the surface resistivity of one surface is at least 10 times the surface resistivity of the other surface, and such a semiconductive resin It is an object to provide a method for manufacturing a sheet.

[0006]

The semiconductive resin sheet according to the present invention comprises a polymer blend of polyimide and doped polyaniline, and the surface resistivity of one surface is at least 10% of the surface resistivity of the other surface. It is characterized by being doubled.

According to the first method of the present invention, a semiconductive resin sheet having such a unique electrical property is obtained.
A casting solution containing a polyamic acid and polyaniline in a dedoped state is cast on a substrate to form a layer of the above solution on the substrate, and then the substrate is peeled off without peeling the layer from the substrate. A dopant that can be made conductive by heating while keeping it in close contact to imidize the polyamic acid, peeling the resin sheet formed on the substrate from the substrate, and then doping the polyaniline to make it conductive. It can be obtained by contacting the above-mentioned resin sheet with.

According to the second method of the present invention,
Casting a film-forming solution containing a polyamic acid and polyaniline in the undoped state and a dopant that can be made conductive by doping this polyaniline on a substrate,
Form a layer of the solution on the substrate, then, without peeling the layer from the substrate, while being in close contact with the substrate, by heating, to imidize the polyamic acid, on the substrate By peeling the formed resin sheet from the base material,
Obtainable.

In such a semiconductive sheet according to the present invention, the resin sheet preferably accounts for 1 to 90% by weight of the total amount of polyimide and polyaniline. Also,
In the first and second methods, when heating the film-forming solution on the substrate, the heating temperature is preferably in the range of 250 to 400 ° C. Such a semiconductive resin sheet according to the present invention has a surface resistivity of 10 ³ to 1 on one surface.
Within the range of 0 ¹¹ Ω / □, the surface resistivity of the other surface is 1
In the range of 0 ⁹ to 10 ¹⁴ Ω / □, and the surface resistivity of one surface is at least 10 of the surface resistivity of the other surface.
It is twice.

In the method of the present invention, as described above,
The film-forming solution is cast on an appropriate substrate, for example, the surface of a sheet made of glass, metal, resin, or the outer or inner surface of a tube made of glass, metal, resin, etc., dried, and heated. By doing so, a resin sheet can be obtained. When the tubular base material is used, a tubular product can be obtained. In the present invention, such a tubular product is also included in the sheet.

As already known, a polyamic acid is prepared as a solution by dissolving an approximately equimolar mixture of tetracarboxylic dianhydride or its derivative and diamine in an organic polar solvent and reacting in a solution state. Obtainable. Therefore, the polyamic acid is prepared as a polyimide precursor, and an insoluble and infusible polyimide is formed by heating such a polyamic acid.

According to the present invention, as such a polyamic acid, a polyamic acid obtained by reacting an aromatic tetracarboxylic dianhydride with an aromatic diamine is preferably used. In the preparation of polyamic acid, as the aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2 , 5,6-Naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl)
Examples thereof include sulfone dianhydride. These may be used alone or in combination of two or more.

Examples of the aromatic diamine include, for example, 4,
4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, p-
Phenylenediamine, m-phenylenediamine, benzidine, 3,3'-dimethoxybenzidine, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenylpropane, 2, 2-bis [4- (4-aminophenoxy) phenyl] propane and the like can be mentioned. These may be used alone or in combination of two or more.

Examples of the organic polar solvent include N-methyl-2-pyrrolidone, N, N'-dimethylacetamide, dimethylsulfoxide, hexamethylenephosphortriamide and the like. If necessary, these organic polar solvents may be mixed with phenols such as cresol, phenol and xylenol, hydrocarbons such as hexane, benzene and toluene. These solvents are also used alone or as a mixture of two or more kinds.

A raw material consisting of the above-mentioned anhydride and diamine in an organic solvent when a solution of polyamic acid is obtained by reacting the above-mentioned aromatic tetracarboxylic dianhydride and aromatic diamine in a solution state. The concentration of the amount is usually 5 to 30.
%, Preferably 10 to 25% by weight. Depending on the anhydride and diamine used, it is usually about 80 ° C or lower, preferably about 2 to 10 at a temperature in the range of 5 to 50 ° C.
By reacting for a time, the polyamic acid can be obtained as a solution.

When an aromatic tetracarboxylic dianhydride and an aromatic diamine are reacted in a solution state, the viscosity of the solution increases with the progress of the reaction. In the present invention, N-methyl at a temperature of 30 ° C. is used. It is preferable to prepare a polyamic acid solution having an intrinsic viscosity of 0.5 or more as a 2-pyridone solution and use this. As described above, by using the polyamic acid solution having an intrinsic viscosity of 0.5 or more, a sheet having excellent mechanical strength reliability can be obtained.

Next, the polyaniline used in the present invention has the general formula (I)

[0018]

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(In the formula, m and n represent the mole fractions of the quinonediimine structural unit and the phenylenediamine structural unit in the repeating unit, and 0 <m <1, 0 <n <1, m
+ N = 1. ) Is a polyaniline which has a quinonediimine structural unit and a phenylenediamine structural unit as main repeating units and is soluble in a solvent in a detoped state. Hereinafter, such a polyamide may be referred to as a quinonediimine / phenylenediamine type polyaniline. The properties and production of such polyaniline are described in detail in JP-A-3-28229.

In particular, the polyaniline used in the present invention is, as described in JP-A-3-28229, a laser Raman spectrum obtained by excitation with light having a wavelength of 457.9 nm in a dedoped state. Among the skeletal vibrations of the substituted benzene, the Raman line intensity Ia of the skeletal stretching vibration that appears at a wave number higher than 1600 cm ^-1
It is preferable that the ratio Ia / Ib of the Raman line intensity Ib of the skeleton stretching vibration appearing at a wave number lower than 1600 cm ⁻¹ is 1.0 or more. Furthermore, the polyaniline used in the present invention preferably has an intrinsic viscosity [η] measured at 30 ° C. in N-methylpyrrolidone of 0.40 dl / g or more.
As described in detail in JP-A-3-28229, the polyaniline having such laser Raman spectrum characteristics has a higher molecular weight and is soluble in a solvent as compared with the conventionally known polyaniline. They can be distinguished and also structurally distinct.

The above-mentioned quinonediimine / phenylenediamine type polyaniline used in the present invention, which is soluble in an organic solvent in a dedoped state and has a predetermined intrinsic viscosity and the above-mentioned laser / Raman spectrum characteristics, is disclosed in Japanese Patent Application Laid-Open No. 3-103. As described in detail in JP-A-28229, the temperature of aniline in a solvent is 5 ° C. or lower, preferably 0 ° C. or lower, in the presence of a protic acid having an acid dissociation constant pKa value of 3.0 or lower. While maintaining the above, an aqueous solution of an oxidant having a standard electrode potential of 0.6 V or more, which is determined as an electromotive force in a reducing half-cell reaction with a standard hydrogen electrode as a reference, is mixed with 1 mol of the oxidant per 1 mol of aniline. Equivalent weight defined as the amount divided by the number of electrons required to reduce one molecule of oxidant, 2 equivalents or more, preferably 2
˜2.5 equivalents are gradually added to form an oxidized polymer of aniline doped with the above-mentioned protonic acid (hereinafter referred to as doped polyaniline), and the doped polyaniline is then removed with a basic substance. It can be obtained by doping.

Thus, the polyaniline obtained by oxidatively polymerizing aniline in the presence of a protonic acid to obtain polyaniline in a doped state and then dedoping this polyaniline has a high molecular weight and various types. Soluble in organic solvent. As such an organic solvent, N-methyl-2-
Pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone, sulfolane and the like can be mentioned. The solubility of such dedoped polyaniline depends on the average molecular weight of polyaniline and the solvent, but 0.5 to 100% of the polymer dissolves and 1 to 30% by weight.
Can be obtained.

According to the present invention, as described above, a film forming solution containing polyamic acid and polyaniline is prepared, and the film forming solution is cast on an appropriate substrate, for example, a glass plate to form a film forming solution. Without peeling the layer of
A sheet of a polymer blend composed of polyimide and polyaniline can be obtained by heating and drying while keeping them in close contact with each other to imidize the polyamic acid.
In order to imidize the polyamic acid, as already known, the layer of the above solution is usually heated to a temperature of 300 ° C. or higher to cause the polyamic acid to form an imide bond.

According to the present invention, in this manner, the film forming solution containing polyamic acid and polyaniline is cast on the substrate, and the solution layer on the substrate is brought into close contact with the substrate to form the solution layer. By heating to imidize the polyamic acid, the surface of the layer is exposed to the air (hereinafter, also referred to as the air surface) and the base material, and the contact with the air is blocked. The behavior of polyaniline with respect to the dopant is remarkably different from that of the surface (sometimes referred to as the base material contact surface).

Thus, according to the present invention, after the resin sheet made of the polymer blend is formed on the substrate by the casting method, the obtained resin sheet is peeled from the substrate, and then polyaniline is added. The semiconductive sheet obtained by doping the above resin sheet with a dopant capable of being doped to give conductivity has a surface resistivity different between a substrate surface and a substrate contact surface, and is usually air. The surface resistivity of the surface has a surface resistivity of at least 10 times the surface resistivity of the substrate contact surface.

To dope the resin sheet separated from the base material, for example, the resin sheet may be dipped in a solution containing the dopant. Further, according to the present invention, a dopant capable of being doped with polyaniline in advance is dissolved in a film forming solution containing the polyamic acid and polyaniline, and such a film forming solution is cast on a substrate. , In a state in which the layer of the film-forming solution on the substrate is in close contact with the substrate, by heating the layer of the solution, by imidizing the polyamic acid, after forming a resin sheet made of a polymer blend, You may peel the obtained resin sheet from a base material. Even by this method, the behavior of polyaniline with respect to the dopant is significantly different between the air surface of the layer of the film forming solution and the base material contact surface. It is possible to obtain a conductive sheet having different surface resistances on the surfaces.

Thus, according to the present invention, a semiconductive sheet having different surface resistivity on the front and back surfaces can be obtained by a simple method without having a discontinuous surface of material and resistance inside. You can

In the present invention, a protonic acid can be preferably used as the dopant. A preferred protic acid as a dopant is a protic acid having an acid solubility constant pKa value of 4.8 or less. As such a protic acid, for example, in addition to inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, fluoroboric acid, phosphorohydrofluoric acid, and perchloric acid,
An organic acid having an acid solubility constant pKa value of 4.8 or less can be mentioned.

The organic acid used in the present invention is, for example,
Organic carboxylic acids or phenols, preferably having an acid dissociation constant pKa value of 4.8 or less. Such organic acids include mono- or polybasic acids such as aliphatic, aromatic, araliphatic and alicyclic. Such an organic acid may have a hydroxyl group, a halogen, a nitro group, a cyano group, an amino group or the like. Therefore, specific examples of such organic acid include, for example, acetic acid, n-butyric acid, pentadecafluorooctanoic acid, pentafluoroacetic acid, trifluoroacetic acid, trichloroacetic acid, dichloroacetic acid, monofluoroacetic acid, monobromoacetic acid, monochloroacetic acid, cyanoacetic acid. , Acetylacetic acid, nitroacetic acid, triphenylacetic acid, formic acid, oxalic acid, benzoic acid, m-bromobenzoic acid, p-chlorobenzoic acid, m-chlorobenzoic acid, p-chlorobenzoic acid, o
-Nitrobenzoic acid, 2,4-dinitrobenzoic acid, 3,5-dinitrobenzoic acid, picric acid, o-chlorobenzoic acid, p
-Nitrobenzoic acid, m-nitrobenzoic acid, trimethylbenzoic acid, p-cyanobenzoic acid, m-cyanobenzoic acid, thymol blue, salicylic acid, 5-aminosalicylic acid, o
-Methoxybenzoic acid, 1,6-dinitro-4-chlorophenol, 2,6-dinitrophenol, 2,4-dinitrophenol, p-oxybenzoic acid, bromophenol blue, mandelic acid, phthalic acid, isophthalic acid, malein Acid, fumaric acid, malonic acid, tartaric acid, citric acid, lactic acid, succinic acid, α-alanine, β-alanine, glycine, glycolic acid, thioglycolic acid, ethylenediamine-N, N '
-Diacetic acid, ethylenediamine-N, N, N ', N'-tetraacetic acid and the like can be mentioned.

Further, the organic acid may have a sulfonic acid or a sulfuric acid group. Examples of such an organic acid include, for example, aminonaphthol sulfonic acid, methanilic acid, sulfanilic acid, allyl sulfonic acid, lauryl sulfuric acid, xylene sulfonic acid, chlorobenzene sulfonic acid,
Methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 1-butanesulfonic acid, 1-hexanesulfonic acid, 1-heptanesulfonic acid, 1-octanesulfonic acid, 1-nonanesulfonic acid, 1-decanesulfonic acid, 1
-Dodecanesulfonic acid, benzenesulfonic acid, styrenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, ethylbenzenesulfonic acid, propylbenzenesulfonic acid, butylbenzenesulfonic acid, pentylbenzenesulfonic acid, hexylbenzenesulfonic acid, heptylbenzenesulfone Acid, octylbenzene sulfonic acid,
Nonylbenzenesulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfonic acid, dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid, octadecylbenzenesulfonic acid, diethylbenzenesulfonic acid, dipropylbenzenesulfonic acid, dibutylbenzenesulfonic acid, methylnaphthalenesulfone Acid, ethylnaphthalenesulfonic acid, propylnaphthalenesulfonic acid, butylnaphthalenesulfonic acid, pentylnaphthalenesulfonic acid, hexylnaphthalenesulfonic acid, heptylnaphthalenesulfonic acid, octylnaphthalenesulfonic acid, nonylnaphthalenesulfonic acid, decylnaphthalenesulfonic acid, undecylnaphthalene Sulfonic acid, dodecylnaphthalenesulfonic acid, pentadecylnaphthalenesulfonic acid,
Octadecylnaphthalenesulfonic acid, dimethylnaphthalenesulfonic acid, diethylnaphthalenesulfonic acid, dipropylnaphthalenesulfonic acid, dibutylnaphthalenesulfonic acid, dipentylnaphthalenesulfonic acid, dihexylnaphthalenesulfonic acid, diheptylnaphthalenesulfonic acid, dioctylnaphthalenesulfonic acid, dinonylnaphthalene Examples thereof include sulfonic acid, trimethylnaphthalenesulfonic acid, triethylnaphthalenesulfonic acid, tripropylnaphthalenesulfonic acid, tributylnaphthalenesulfonic acid, camphorsulfonic acid and acrylamido-t-butylsulfonic acid.

Further, in the present invention, a polyfunctional organic sulfonic acid having two or more sulfonic acid groups in the molecule can also be used. Examples of such polyfunctional organic sulfonic acids include ethanedisulfonic acid, propanedisulfonic acid, butanedisulfonic acid, pentanedisulfonic acid, hexanedisulfonic acid, heptanedisulfonic acid, octanedisulfonic acid, nonanedisulfonic acid, decanedisulfonic acid, benzene. Disulfonic acid, naphthalene disulfonic acid,
Toluene disulfonic acid, ethylbenzene disulfonic acid,
Propylbenzenedisulfonic acid, butylbenzenedisulfonic acid, dimethylbenzenedisulfonic acid, diethylbenzenedisulfonic acid, dipropylbenzenedisulfonic acid,
Dibutylbenzenedisulfonic acid, methylnaphthalenedisulfonic acid, ethylnaphthalenedisulfonic acid, propylnaphthalenedisulfonic acid, butylnaphthalenedisulfonic acid, pentylnaphthalenedisulfonic acid, hexylnaphthalenedisulfonic acid, heptylnaphthalenedisulfonic acid,
Octyl naphthalene disulfonic acid, nonyl naphthalene disulfonic acid, dimethyl naphthalene disulfonic acid, diethyl naphthalene disulfonic acid, dipropyl naphthalene disulfonic acid, dibutyl naphthalene disulfonic acid, naphthalene trisulfonic acid, naphthalene tetrasulfonic acid, anthracene disulfonic acid, anthraquinone disulfonic acid,
Phenanthrene disulfonic acid, fluorenone disulfonic acid, carbazole disulfonic acid, diphenyl methane disulfonic acid, biphenyl disulfonic acid, terphenyl disulfonic acid, terphenyl trisulfonic acid, naphthalene sulfonic acid-formalin condensate, phenanthrene sulfonic acid-formalin condensate, Examples thereof include anthracene sulfonic acid-formalin condensate, fluorene sulfonic acid-formalin condensate, and carbazole sulfonic acid-formalin condensate. The position of the sulfonic acid group in the aromatic ring is arbitrary.

Further, in the present invention, the organic acid may be a polymeric acid. Examples of such a polymer acid include polyvinyl sulfonic acid, polyvinyl sulfuric acid, polystyrene sulfonic acid, sulfonated styrene-butadiene copolymer, polyallyl sulfonic acid, polymethallyl sulfonic acid, poly-2-acrylamido-2-methyl. Propane sulfonic acid, polyhalogenated acrylic acid, polyisoprene sulfonic acid, N-sulfoalkylated polyaniline, nuclear sulfonated polyaniline and the like can be mentioned. A fluorine-containing polymer known as Nafion (registered trademark of Du Pont, USA) is also suitably used as the polymer acid.

In the present invention, as a method of incorporating the above-mentioned protonic acid dopant into the film-forming solution, a basic substance such as triethylamine is used, as disclosed in JP-A-3-28229. The method of adding with a dopant can also be used suitably.

Such a protonic acid makes polyaniline conductive by protonating the polyaniline represented by the general formula (I) to the imine nitrogen of the quinonediimine structure. Usually, as described above, in the quinonediimine / phenylenediamine type polyaniline represented by the general formula (I) obtained by oxidative polymerization of aniline in a solution, the values of m and n are almost the same.

As described above, since quinonediimine / phenylenediamine type polyaniline has many quinonediimine structures, it is
It gives polyaniline having high conductivity.

In the present invention, the formula

[0037]

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The solvent-soluble polyaniline having an imino-p-phenylene structural unit represented by the following as a main repeating unit (hereinafter sometimes referred to as imino-p-phenylene type polyaniline) is the above-mentioned quinone diimine / phenylenediamine type polyaniline. It dissolves in various organic solvents better than that of quinonediimine.
It can be used together with the phenylenediamine type polyaniline or in place of the above quinonediimine / phenylenediamine type polyaniline.

Such an imino-p-phenylene type polyaniline is obtained by reducing the quinonediimine / phenylenediamine type polyaniline with a reducing agent, as described in JP-A-3-52929. You can In the present invention, such imino-p-phenylene type polyaniline also has an intrinsic viscosity [η] of 0.40 measured at 30 ° C. in N-methylpyrrolidone.
It is preferably dl / g or more.

Examples of the reducing agent include phenylhydrazine, hydrazine, hydrazine hydrate, hydrazine sulfate,
Hydrazine compounds such as hydrazine hydrochloride and reductive metal hydride compounds such as lithium aluminum hydride and lithium borohydride are preferably used. Hydrazine hydrate or phenylhydrazine is particularly preferably used as the reducing agent because it does not produce a residue after the reduction reaction.

When such an imino-p-phenylene type polyaniline is used, a film-forming solution containing it is cast on a substrate to form a layer of the film-forming solution on the substrate and then heated. When the resin sheet is formed on the substrate and heated to imidize the polyamic acid, the imino-
The p-phenylene type polyaniline becomes a quinonediimine / phenylenediamine type polyaniline by air oxidation. When the film forming solution contains a dopant, the quinonediimine / phenylenediamine type polyaniline is doped to form a conductive polyaniline. Then, a semiconductive resin sheet is provided.

Also, when the resin sheet is formed and then a dopant is brought into contact with the resin sheet, the quinonediimine / phenylenediamine type polyaniline is produced in the resin sheet as described above, and this is doped. Will be done.

The shape of the semiconductive resin sheet according to the present invention is not particularly limited, and as described above, it may be a sheet shape having a flat or curved surface or a tube shape. Further, it may be discontinuous or continuous.

[0044]

As described above, the semiconductive resin sheet according to the present invention is composed of a polymer blend of polyimide and conductive polyaniline, and has a uniform material without discontinuity of different resistance values inside. While having, the surface resistivity of one surface of the sheet is at least 10 times the surface resistivity of the other surface, and since it is also excellent in mechanical properties, taking advantage of its unique electrical properties, For example, it can be suitably used in battery electrode materials, electromagnetic shield materials, electrostatic adsorption films, antistatic materials, image forming apparatus parts, electronic devices and the like.

[0045]

EXAMPLES The present invention will be described below with reference to examples and reference examples, but the present invention is not limited to these examples.

Reference Example 1 (Production of Polyaniline in Doped State by Oxidative Polymerization of Aniline) Distilled water 600 in a 10 liter separable flask equipped with a stirrer, a thermometer and a straight tube adapter.
0 g, 360% 36% hydrochloric acid and 400 g aniline (4.2
95 mol) was charged in this order to dissolve the aniline. Separately, while cooling with ice water, 434 g (4.295 mol) of 97% concentrated sulfuric acid was added to 1493 g of distilled water in a beaker and mixed to prepare a sulfuric acid aqueous solution. This aqueous sulfuric acid solution was added to the separable flask, and the entire flask was cooled to −4 ° C. in a low-temperature constant temperature bath.

Next, 980 g (4.295 mol) of ammonium peroxodisulfate was added to 2293 g of distilled water in a beaker and dissolved to prepare an aqueous oxidant solution. The entire flask was cooled in a low temperature constant temperature bath, while maintaining the temperature of the reaction mixture at -3 ° C or lower, while stirring, to an acidic aqueous solution of aniline salt, using a tubing pump, using a straight pipe adapter, the above ammonium peroxodisulfate aqueous solution. 1 ml
The mixture was gradually added dropwise at a rate of not more than / minute. Initially, the colorless and transparent solution changes from green-blue to black-green as the polymerization proceeds,
Then, a black-green powder was deposited.

Although a temperature rise was observed in the reaction mixture during the precipitation of the powder, the temperature in the reaction system was suppressed to -3 ° C or lower. Thus, after the dropping of the ammonium peroxodisulfate aqueous solution was completed in 7 hours, another 1 hour-
Stirring was continued at a temperature below 3 ° C. The obtained powder was filtered, washed with water, washed with acetone, and vacuum dried at room temperature to obtain 430 g of conductive polyaniline doped with sulfuric acid as a black green powder.

(Dope Doping of Doped Conductive Polyaniline with Ammonia) 350 g of the above-mentioned doped conductive polyaniline powder was added to 4 liters of 2N ammonia water, and the rotation speed was 5000 rpm with an auto homomixer.
The mixture was stirred for 5 hours. The mixture turned from black green to bluish purple. The powder was filtered off with a Buchner funnel and washed repeatedly with distilled water while stirring in a beaker until the filtrate became neutral, and then with acetone until the filtrate became colorless. Then, the powder was vacuum dried at room temperature for 10 hours to obtain 280 g of black-brown dedoped polyaniline powder.
I got

Reference Example 2 (Preparation of Polyimide Precursor Solution A) N-methyl-2-pyrrolidone was added to an approximately equimolar mixture of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and p-phenylenediamine. A polyamic acid solution having a viscosity of 1000 poise (temperature of 25 ° C., measured value by a B-type viscometer) and a fixed viscosity of 2.1 is prepared by reacting in a solution (concentration 20% by weight) at a temperature of 20 to 60 ° C. for 12 hours. did.

(Preparation of Polyimide Precursor Solution B) An approximately equimolar mixture of pyromellitic dianhydride and 3,3 ′, 4,4′-diaminodiphenyl ether was added to an N-methyl-2-pyrrolidone solution (concentration: 20% by weight). ) At a temperature of 5 to 20 ° C. for 10 hours to prepare a polyamic acid solution having a viscosity of 2000 poise (temperature of 25 ° C., value measured by B-type viscometer) and an intrinsic viscosity of 2.5.

Example 1 2.98 g of phenylhydrazine was dissolved in 180 g of N-methyl-2-pyrrolidone, and then 20 g of the polyaniline powder obtained in Reference Example 1 was dissolved in this to remove 10% by weight of concentration. A doped polyaniline solution was obtained. Next, 100 g of the polyimide precursor solution A obtained in Reference Example 2 was added to this polyaniline solution and stirred for 1 hour to obtain a film-forming solution composed of polyaniline in the undoped state and the polyimide precursor.

Using this film forming solution, a film was formed as follows. That is, the above film-forming solution was coated on a glass plate using a knife coater having a gap of 120 μm, and then treated at 150 ° C. for 20 minutes, 200 ° C. for 20 minutes, 250 ° C. for 20 minutes, and finally 300 ° C. for 20 minutes. Then, after removing the solvent and imidizing, the resin sheet was peeled off to obtain a resin sheet made of a polymer blend of polyaniline and polyimide. This resin sheet was composed of 50% by weight of undoped polyaniline and 50% by weight of polyimide, and had a thickness of 15 μm.

Then, 100 g of methanesulfonic acid (dopant) was dissolved in 400 g of distilled water, and 500 g of methanol was added to this to prepare a dopant solution. The above resin sheet was immersed in this dopant solution at room temperature for 10 minutes for doping. When the surface resistance of the front and back surfaces of the semiconductive resin sheet thus obtained was measured,
The sheet surface exposed to the air during the film formation (hereinafter referred to as the air surface of the sheet) was 1.5 × 10 ¹¹ Ω / □, the surface in contact with the glass (hereinafter, the base material contact surface of the sheet). Was 1.1 × 10 ⁸ Ω / □.

Example 2 In the same manner as in Example 1, 200 g of an undoped polyaniline solution having a concentration of 10% by weight was prepared. Next, 300 g of the polyimide precursor solution B obtained in Reference Example 2 was added to this polyaniline solution and stirred for 1 hour to obtain a film-forming solution composed of polyaniline in the undoped state and the polyimide precursor.

Using this film forming solution, a film was formed as follows. That is, after coating the above film-forming solution on a glass plate using a knife coater having a gap of 240 μm, solvent removal and imidization were carried out in the same manner as in Example 1, followed by peeling from the glass plate to remove polyimide. A resin sheet made of a polymer blend of polyaniline in the undoped state and the above was obtained. This resin sheet is composed of 25% by weight of polyaniline and 75% by weight of polyimide and has a thickness of 30 μm.
Met.

Then, in the same manner as in Example 1, this resin sheet was subjected to doping treatment. When the surface resistance of the obtained semiconductive resin sheet was measured, the air surface was 2.
7 × 10 ¹³ Ω / □, substrate contact surface is 1.7 × 10 ⁹ Ω / □
Met.

Example 3 In the same manner as in Example 1, 200 g of an undoped polyaniline solution having a concentration of 10% by weight was prepared. Separately, 12.5 g of p-toluenesulfonic acid monohydrate (dopant) was added to N
-Methyl-2-pyrrolidone dissolved in 113.5 g, 10
A wt% p-toluenesulfonic acid solution was prepared. Then, these two solutions were mixed to prepare a solution of doped polyaniline.

100 g of the polyimide precursor solution A obtained in Reference Example 2 was added to this solution, and the mixture was stirred for 1 hour.
A film-forming solution comprising a doped polyaniline and a polyimide precursor was obtained. After coating this film-forming solution on a glass plate with a knife coater having a gap of 240 μm, solvent removal and imidization were carried out in the same manner as in Example 1, and then peeled from the glass plate to remove polyimide and p-toluene. A polymer blend resin sheet consisting of sulfonic acid-doped polyaniline was obtained. This resin sheet was composed of 50% by weight of doped polyaniline and 50% by weight of polyimide, and had a thickness of 25 μm.

The volume resistivity of this semiconductive resin sheet was measured and found to be 3 × 10 ¹⁰ Ω · cm. Moreover, when the surface resistance was measured, the air surface was 2.5 × 10 ¹² Ω /
□, the contact surface of the substrate was 6.7 × 10 ⁹ Ω / □.

Example 4 In the same manner as in Example 1, 200 g of a 10 wt% undoped polyaniline solution was prepared. Separately, 21.5 g of dodecylbenzenesulfonic acid (dopant) was dissolved in 193.5 g of N-methyl-2-pyrrolidone to prepare a 10 wt% dodecylbenzenesulfonic acid solution. Then, these two solutions were mixed to prepare a solution of doped polyaniline. 100 g of the polyimide precursor solution A obtained in Reference Example 2 was added to this solution, and the mixture was stirred for 1 hour to obtain a film forming solution composed of doped polyaniline and a polyimide precursor.

This film-forming solution was coated on a glass plate with a knife coater having a gap of 240 μm, and then solvent removal and imidization were carried out in the same manner as in Example 1,
It was peeled from the glass plate to obtain a resin sheet of a polymer blend composed of polyimide and polyaniline doped with dodecylbenzenesulfonic acid. This resin sheet
Doped polyaniline 50% by weight and polyimide 50
% And had a thickness of 25 μm.

The volume resistivity of this semiconductive resin sheet was measured and found to be 8 × 10 ¹⁰ Ω · cm. Moreover, when the surface resistance was measured, the air surface was 4.6 × 10 ¹² Ω /
□, the contact with the substrate was 1.3 × 10 ¹⁰ Ω / □.

Claims (6)

[Claims] 1. A semiconductive resin sheet comprising a polymer blend of polyimide and polyaniline in a doped state, wherein the surface resistivity of one surface is at least 10 times the surface resistivity of the other surface. 2. The semiconductive resin sheet according to claim 1, which contains 1 to 90% by weight of polyaniline. 3. Casting a film-forming solution containing a polyamic acid and polyaniline in an undoped state onto a substrate to form a layer of the solution on the substrate, and then peeling the layer from the substrate. Instead, heat it while keeping it in close contact with the base material,
After imidizing the polyamic acid, peeling the resin sheet formed on the substrate from the substrate, and then contacting the resin sheet with a dopant that can be made conductive by doping the polyaniline. A method for producing a semiconductive resin sheet, characterized in that the surface resistivity of one surface is at least 10 times the surface resistivity of the other surface. 4. A casting solution containing a polyamic acid, polyaniline in an undoped state, and a dopant capable of being doped with this polyaniline to be conductive is cast on a substrate to form a layer of the solution on the substrate. Formed, then
Without peeling the layer from the base material, while keeping it in close contact with the base material, after heating to imidize the polyamic acid,
A method for producing a semiconductive resin sheet, characterized in that a resin sheet formed on a base material is peeled off from the base material, wherein the surface resistivity of one surface is at least 10 times the surface resistivity of the other surface. 5. The semiconductive resin sheet contains polyaniline in the range of 1 to 1.
The method for producing a semiconductive resin sheet according to claim 3 or 4, wherein the content is 90% by weight. 6. The method for producing a semiconductive resin sheet according to claim 3, wherein the film forming solution is heated to a temperature of 250 to 400 ° C.