JPH08259709A - Semiconductor resin sheet and production thereof - Google Patents

Abstract

PURPOSE: To obtain a high elasticity modulus resin sheet which has stable semiconductivity even under fluctuating environmental conditions and is suitable for use as an electrode material for batteries, etc., by forming a film from a solution containing a polyimide precursor and an undoped polyaniline. CONSTITUTION: A solution containing a polyamic acid and an undoped polyaniline is cast on a substrate to form a layer of the solution. The layer is heated to 60-200 deg.C to form a resin sheet on the substrate. The sheet is peeled off and then heated to 250-400 deg.C to imidize the polyamic acid. Thus, the objective sheet is obtained which comprises a blend of a polyimide and an undoped polyaniline, and has a modulus of elasticity of 200kgf/mm<2> or higher and a volume resistivity of 10<7> -10<14> Ω.cm. Since the sheet contains no dopants, the semiconductivity thereof is stable even when environmental conditions including humidity fluctuate.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a semi-conductive resin sheet which is composed of a polymer blend containing polyaniline in an undoped state or a doped state together with a polyimide, has semi-conductivity, and is tough and has excellent mechanical properties. The present invention relates to a method for producing such a semiconductive resin sheet. Such a semiconductive resin sheet can be preferably used in, for example, an electrode material for batteries, an electromagnetic shield material, an electrostatic attraction film, an antistatic material, an image forming apparatus component, an electronic device and the like.

[0002]

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.

On the other hand, a semiconductive polymer blend composed of a conductive polyaniline and another resin is disclosed in, for example, Japanese Patent Laid-Open No.
It is already known as described in Japanese Patent Publication No.-63865. This semiconductive polymer blend is in a dedoped state, that is, a mixture of polyaniline not doped with a dopant and another resin is prepared, and then this is subjected to a doping treatment with a dopant. There is a problem that the dopant is easily dedoped due to moisture or heat, and therefore the electric resistance value thereof is likely to change depending on the environment. Further, there is a problem that many steps such as film formation, doping, washing and drying are required to obtain the conductive polymer blend by the above method.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the conventional semiconductive resin sheet, and is capable of responding to changes in the environment.
An object of the present invention is to provide a semiconductive resin sheet having stable semiconductivity and a method for producing the same.

[0005]

The semiconductive resin sheet according to the present invention comprises a polymer blend of polyimide and undoped polyaniline and has an elastic modulus of 200 kgf / mm.
^{It is 2} or more, and the volume resistivity is in the range of 10 ⁷ to 10 ¹⁴ Ω · cm.

According to the present invention, such a semiconductive resin sheet is prepared by casting a film-forming solution containing polyamic acid and polyaniline in the undoped state on a substrate, and forming a layer of the film-forming solution on the substrate. Form and heat to a temperature of 60 to 200 ° C to form a resin sheet on the substrate, then peel the resin sheet from the substrate, and then heat the resin sheet to a temperature of 250 to 400 ° C. Then, it can be obtained by imidizing a polyamic acid.

Further, according to the present invention, there is also provided a method for producing a semiconductive resin sheet having higher conductivity, which is composed of a polyaniline in a doped state, that is, a polymer blend containing polyaniline doped with a dopant, together with polyimide. Provided. According to the present invention, such a semiconductive resin sheet is cast on a substrate with a film-forming solution containing a polyamic acid, polyaniline, and a dopant capable of being doped with the polyaniline so as to be conductive. Forming a layer of the above film-forming solution,
To 200 ° C. to form a resin sheet on the base material, then peel the resin sheet from the base material, and then heat the resin sheet to a temperature of 250 to 400 ° C. It can be obtained by imidizing an acid.

According to the present invention, in the semiconductive resin sheet made of the above polymer blend, the polyaniline in the undoped state or the doped state is preferably in the range of 1 to 90% by weight.

In the present invention, the semiconductive resin sheet means a resin sheet having a volume resistivity in the range of 10 ⁷ to 10 ¹⁵ Ω · cm.

As already known, a polyamic acid is prepared as a solution by dissolving an approximately equimolar mixture of tetracarboxylic dianhydride or its derivative and a 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.

According to the present invention, as described above, a solution of polyamic acid is prepared, and a solution of polyaniline in the undoped state or polyaniline in the undoped state and this polyaniline are doped to obtain conductivity. A solution containing a dopant that can be prepared is mixed, and these solutions are mixed to form a film forming solution, which is an appropriate substrate, for example,
By casting on the surface of a sheet made of glass, metal, resin, or the like, or on the outer surface or inner surface of a tube made of glass, metal, resin, etc., drying, heating, and imidizing polyamic acid, polyimide It is possible to obtain a semiconducting resin sheet made of a polymer blend of and polyaniline. 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.

In the preparation of the polyamic acid, examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, and 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 And bis (3,4-dicarboxyphenyl) sulfone dianhydride. These may be used alone or in combination of two or more.

As the aromatic diamine, 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 comprising the above-mentioned anhydride and diamine in an organic solvent when a solution of a 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 the aromatic tetracarboxylic dianhydride and the 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.degree. 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)

[0019]

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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.

Particularly, 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 the undoped 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 JP-A-3- 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, contains 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 a doped polyaniline, 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 undoped 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. The undoped polyaniline used in the present invention has semiconductivity by itself.

According to the present invention, as described above, a film forming solution containing polyamic acid, polyaniline in the undoped state (a dopant capable of being doped with this polyaniline to be conductive) is prepared, and The film-forming solution is cast on an appropriate substrate, for example, a glass plate, a layer of the film-forming solution is formed on the substrate, and heated to a temperature of 60 to 200 ° C to form a resin sheet on the substrate. Then, the resin sheet is peeled off from the base material, and then the resin sheet is heated to a temperature of 250 to 400 ° C. to imidize the polyamic acid, whereby the polyimide and the conductive material in the (de) doped state are conductive. It is possible to obtain a semiconductive resin sheet made of a polymer blend with polyaniline.

In the present invention, a protonic acid can be preferably used as a dopant for doping polyaniline to make it conductive. 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

[0033]

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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 quinonediimine / 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 the polyaniline is cast on a substrate to form a layer of the film-forming solution on the substrate and heated. , A resin sheet is formed on a base material, the resin sheet is then peeled from the base material, and then the resin sheet is further heated to imidize the polyamic acid, and by air oxidation, quinone diimine phenylene When it becomes a diamine-type polyaniline and the film-forming solution contains a dopant, this quinonediimine / phenylenediamine-type polyaniline is doped to form a conductive polyaniline to give a semiconductive resin sheet.

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 having a flat or curved surface, or a tube. Further, it may be discontinuous or continuous.

[0039]

As described above, according to the present invention, a film is formed from a film forming solution containing polyimide, undoped polyaniline and (a dopant capable of being doped with this polyaniline to be conductive). This makes it possible to easily obtain a semiconductive resin sheet made of a polymer blend of polyimide and polyaniline in a (de) doped state.

In particular, according to the present invention, the semiconductive resin sheet obtained by using the polyaniline in the undoped state originally contains no dopant, so that the semiconductive resin sheet is irrespective of fluctuations in environmental conditions such as moisture. Is substantially constant. On the other hand, according to the present invention, when a semi-conductive resin sheet is formed using a film-forming solution containing polyaniline in an undoped state and a dopant that makes the polyaniline conductive by doping, a method different from the method of doping after film formation is used. ,
By the film formation, a semiconductive resin sheet can be immediately obtained, and further, in the obtained semiconductive resin sheet, the dopant is difficult to be dedoped due to the influence of the environment such as moisture and heat, and thus, to the environment. And stable semi-conductivity.

[0041]

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) 600 ml of distilled water was placed in a 10 liter separable flask equipped with a stirrer, a thermometer and a straight pipe 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 oxidizing agent aqueous 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 at the time of powder precipitation, the temperature in the reaction system was suppressed to -3 ° C or lower. Thus, after the dropping of the aqueous ammonium peroxodisulfate solution was completed over 7 hours, the stirring was continued for another 1 hour at a temperature of -3 ° C or lower.

The obtained powder was filtered, washed with water, washed with acetone, and vacuum dried at room temperature to obtain 430 g of sulfuric acid-doped conductive polyaniline as a black-green powder. (Dedoping of Doped Conductive Polyaniline with Ammonia) 350 g of the above doped conductive polyaniline powder was added to 4 liters of 2N ammonia water, and the mixture was stirred with an auto homomixer at a rotation speed of 5000 rpm for 5 hours. The mixture turned from black green to bluish purple. The powder is filtered off with a Buchner funnel and washed repeatedly with distilled water while stirring in a beaker until the filtrate becomes neutral,
Subsequently, it was washed 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.

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 dope. A state 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 glass plate was peeled off to obtain a semiconductive resin sheet having a thickness of 15 μm and made of a polymer blend of undoped polyaniline and polyimide.

This semiconductive resin sheet was composed of 50% by weight of polyaniline in the undoped state and 50% by weight of polyimide, and had a volume resistivity of 3 × 10 ¹¹ Ω · cm. As a result of a tensile test, the strength was 24 kgf / cm 2. The elastic modulus was mm ² and the elastic modulus was 520 kgf / mm ² .

Example 2 In the same manner as in Example 1, 200 g of a 10 wt% concentration undoped polyaniline solution 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.

A film was formed using this film forming solution 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 semiconductive resin sheet having a thickness of 30 μm and made of a polymer blend of polyaniline in a dedoped state was obtained.

This semiconductive resin sheet was composed of 25% by weight of polyaniline in an undoped state and 75% by weight of polyimide, and had a volume resistivity of 4 × 10 ¹² Ω · cm. As a result of a tensile test, the strength was 16 kgf / cm. mm ² and elastic modulus were 260 kgf / mm ² .

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, 12.6 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. This film forming solution was coated on a glass plate with a knife coater having a gap of 240 μm, and then heated at 150 ° C. for 30 minutes to remove the solvent.
Peel the sheet thus obtained from the glass plate,
By heating at 300 ° C. for 20 minutes, a 25 μm thick semiconductive resin sheet of a polymer blend consisting of polyimide and polyaniline doped with p-toluenesulfonic acid was obtained.

This semiconductive 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 8 × 10 ¹⁰ Ω · cm. Moreover, when the surface resistance was measured, it was 2 × 10 ⁹ Ω.
It was / □. The semiconductive sheet was immersed in distilled water for 24 hours. After drying, the volume resistivity was measured and found to be 1 × 10 ¹¹ Ω · cm.

Example 4 In the same manner as in Example 1, 200 g of a 10 wt% concentration 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 polyaniline in the doped state and the polyimide precursor. This film forming solution was coated on a glass plate with a knife coater having a gap of 240 μm, and then heated at 150 ° C. for 30 minutes to remove the solvent. The sheet thus obtained was peeled from the glass plate, heated at 300 ° C. for 20 hours, and a polymer blend of polyimide and polyaniline doped with dodecylbenzenesulfonic acid and having a thickness of 25 μm. Got

This semiconductive resin sheet was composed of 50% by weight of doped polyaniline and 50% by weight of polyimide, and had a thickness of 25 μm. When the volume resistivity of this semiconductive resin sheet was measured, it was 2 × 10 ¹¹ Ω · cm. Also, when the surface resistance was measured, it was 2 × 10 ¹⁰ Ω
It was / □.

Comparative Example 1 100 g of p-toluenesulfonic acid was dissolved in 400 g of distilled water, and 500 g of methanol was added to this to prepare a dopant solution. A semiconductive resin sheet made of the polymer blend of the polyimide obtained in Example 1 and polyaniline in the undoped state was dipped in this dopant solution for 60 hours to dope the polyaniline. When the volume resistivity of the obtained resin sheet was measured, it was 7 × 1.
It was 0 ¹⁰ Ω · cm. In addition, this resin sheet was used in Example 5
After dipping in distilled water for 24 hours in the same manner as above and drying, the surface resistance was measured and found to be 9 × 10 ¹¹ Ω · cm.

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Claims (3)

[Claims] 1. A polymer blend of polyimide and undoped polyaniline having an elastic modulus of 200 kgf / mm.
^A semiconductive resin sheet having a volume resistivity of ² or more and a volume resistivity of 10 ⁷ to 10 ¹⁴ Ω · cm. 2. A casting solution containing a polyamic acid and polyaniline in an undoped state is cast on a substrate to form a layer of the above-mentioned casting solution on the substrate and heated to a temperature of 60 to 200 ° C. To form a resin sheet on the base material, then peel the resin sheet from the base material, and then heat the resin sheet to a temperature of 250 to 400 ° C. to imidize the polyamic acid. Consisting of a polymer blend of polyimide and deanimized polyaniline,
Elastic modulus is 200 kgf / mm ² or more and volume resistivity is 10
^A method for producing a semiconductive resin sheet in the range of ⁷ to 10 ¹⁴ Ω · cm. 3. A casting solution containing a polyamic acid, polyaniline, and a dopant capable of being doped with the polyaniline to be conductive is cast on a substrate to form a layer of the above-mentioned casting solution on the substrate. , To a temperature of 60 to 200 ° C. to form a resin sheet on the substrate, and then
A method for producing a semiconductive resin sheet, characterized in that the resin sheet is peeled from a base material, and then the resin sheet is heated to a temperature of 250 to 400 ° C. to imidize polyamic acid.