JPH08120040A - Heat-resistant electrical insulating material and production of heat-resistant electrical insulating film from the same - Google Patents

Abstract

PURPOSE: To obtain a heat-resistant electrical insulating material excellent in adhesion to various substrates, electrical characteristics, resistances to heat and bending, and coating film hardness by using a specific arom. polyimine. CONSTITUTION: An arom. polyimine used in this invention comprises repeating units represented by formula IV, is formed from an arom. dialdehyde represented by formula I (wherein R<1> , R<2> , and R<3> are each H, an alkyl, or an aryl provided the sum of the numbers of their carbon atoms is 10 or lower) and an arom. diamine represented by formula II [wherein X is a single bond, a 2-6C alkylene, arylene, O, S, SO2 , Y<1> -Ar-Y<1> (wherein Ar is phenylene: and Y<1> is a single bond, a 2-6C alkylene, arylene, O, S, or SO2 ), or Y<1> -Ar-Y<1> -Ar-Y<1> -], and is obtd. by thermally dehydrating an arom. polyimine oligomer having repeating units represented by formula III and a number average degree of polymn. of 2-20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat resistant insulating material and a method for producing a heat resistant electrical insulating film using the same. Specifically, using a novel aromatic polyimine, electricity,
The present invention relates to a heat-resistant electric insulating material that can be widely used as an insulating material related to the electronic field and a method for manufacturing a heat-resistant electric insulating film using the same.

[0002]

2. Description of the Related Art Heretofore, aromatic polymers have generally been used as heat-resistant electrically insulating materials. A typical example thereof is polyimide. Such a polyimide is excellent in heat resistance and electric insulation, but has a drawback that it is not used alone as an adhesive property to a substrate because it is mainly used as a film. Polyimide, which is a precursor of polyimide, is also used as a polar solvent solution, but since it is a varnish of a polymer, it has a high viscosity and its stability with time is extremely poor and it is very difficult to handle.

Polyesterimide varnishes, polyamideimide ester varnishes, polyamideimide varnishes, etc. have been developed to improve the problems of polyimide. These have a relatively low varnish viscosity and are easy to handle. However, since it contains an ester bond and an amide bond, the heat resistance temperature is low, and the amidation and esterification speeds are slow and curing takes a long time. There is also a problem with the adhesion to the substrate.

Further, a nadic acid terminal reaction type imide has been developed as a terminal reaction type. However, it is very difficult to adjust the molecular weight of the oligomer and the imidization reaction rate, and the reactivity of the double bond of the nadic acid moiety is poor, so a high final molding temperature is required. As a similar product, a varnish of an adduct of bismaleimide with a diamine, a diallyl compound or triazine has been developed. These have a characteristic that the molding temperature is low, but they are inferior in heat resistance because they contain less aromatic components. Furthermore, although an acetylene-terminated polyimide oligomer has been developed, it has excellent heat resistance, but since the melting point of the oligomer is higher than the reaction temperature of acetylene, the fluidity of the resin is poor and molding is difficult.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat resistant electric insulating material which is excellent in heat resistance and electric insulation and is easy to handle.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to develop a polymer material that can be used as a heat-resistant material. As a result, an aromatic polyimine represented by the following general formula (3) is obtained. It was found that the above purpose was met. The present invention has been completed based on this new finding.

That is, the general formula (1):

[0008]

[Chemical 9]

(In the formula, R ¹ , R ² and R ³ are each independently a hydrogen atom, an alkyl group or an aryl group;
¹ , the sum of R ² and R ³ is 10 or less), and an aromatic dialdehyde having a phenolic hydroxyl group,
General formula (2):

[0010]

[Chemical 10]

(Wherein X is a single bond, a linear or branched alkylene group having 6 or less carbon atoms, an arylene group, an oxygen atom, a sulfur atom, --SO _2- , a general formula: --Y ¹ --A
r—Y ¹ — (In the formula, Ar is a phenylene group, Y ¹ is a single bond, a linear or branched alkylene group having 6 or less carbon atoms, an arylene group, an oxygen atom, a sulfur atom or —S
O ₂ − is shown. ) Or a general formula: —Y ¹ —
An aromatic diamine represented by Ar-Y ¹ -Ar-Y ^1- (in the formula, Ar and Y ¹ are the same as the above), and is represented by the general formula (3):

[0012]

[Chemical 11]

An aromatic polyimine oligomer having a repeating unit represented by the formula (wherein R ¹ , R ² , R ³ and X are the same as above) and having a number average degree of polymerization of 2 to 20 is dehydrated by heating. General formula (3) obtained by processing:

[0014]

[Chemical 12]

A heat-resistant electrically insulating material comprising an aromatic polyimine having a repeating unit represented by the formula (wherein R ¹ , R ² , R ³ and X are the same as described above), and the general formula (3) A varnish of an aromatic polyimine oligomer having a number average degree of polymerization of 2 to 20 and having a repeating unit represented by the formula (3), characterized in that the varnish is heated and dehydrated. The present invention relates to a method for producing a heat-resistant electric insulating film made of an aromatic polyimine having a repeating unit represented by

The aromatic dialdehyde component used in the present invention has the general formula (1):

[0017]

[Chemical 13]

(In the formula, R ¹ , R ² and R ³ are each independently a hydrogen atom, an alkyl group or an aryl group;
The total sum of ¹ , R ² and R ³ is 10 or less), which is an aromatic dialdehyde having a fephenolic hydroxyl group. Of the aromatic dialdehydes, R ¹ and R in the general formula (1) are taken into consideration in view of availability of raw materials and price.
It is preferable that the total of ² and R ³ is about 1 to 4.

Specific examples of the aromatic dialdehyde include 2,6-diformylphenol and 2,6-
Diformyl-4-methylphenol, 2,6-diformyl-4-ethylphenol, 2,6-diformyl-4-
t-butylphenol, 2,6-diformyl-4-octylphenol, 2,6-diformyl-4-phenylphenol, 2,6-diformyl-3,4-dimethylphenol, 2,6-diformyl-3,4,5- Examples include trimethylphenol. Any of these aromatic dialdehydes can be easily obtained by oxidation of the corresponding dialcohol.

The aromatic diamine component used in the present invention has the general formula (2):

[0021]

Embedded image

(In the formula, X is a single bond, a linear or branched alkylene group having 6 or less carbon atoms, an arylene group,
Oxygen atom, sulfur atom, -SO ₂ -, the general formula: -Y ¹ -
Ar-Y ^1- (wherein Ar is a phenylene group, Y ¹ is a single bond, a linear or branched alkylene group or arylene group having 6 or less carbon atoms, an oxygen atom, a sulfur atom or -SO _2- Group or a general formula represented by:
-Y ¹ -Ar-Y ¹ -Ar-Y ^1- (in the formula, Ar, Y ¹
Is the same as above. ) Represents a group represented by. ) Is an aromatic diamine. X in the general formula (2) or the X
When Y ¹ in the general formula representing an example group is an alkylene group or an arylene group, the number of carbon atoms of the alkylene group is taken into consideration in view of the solubility of the aromatic polyimine oligomer obtained and the heat resistance of the aromatic polyimine. Is preferably 1 to 4, and the arylene group is preferably a phenylene group.

Typical examples of the aromatic diamine include benzidine, 3,3'-diaminobiphenyl,
3,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,
4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 3,4 '
-Diaminodiphenyl sulfone, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2-bis (4-aminophenyl) propane, bis (4-aminophenyl) methane An aromatic diamine having two benzene rings such as 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene ,
1,4-bis (4-aminophenyl) benzene, 1,3
-Bis (4-aminophenyl) benzene, 1,4-bis (3-aminophenyl) benzene, α, α'-bis (4
-Aminomethyl) -1,4-diisopropylbenzene,
Aromatic diamines having three benzene rings such as α, α′-bis (3-aminomethyl) -1,4-diisopropylbenzene; 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′- Bis (3-aminophenoxy) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, bis [4- ( Four
-Aminophenoxy) phenyl] methane, bis [4-
(3-Aminophenoxy) phenyl] methane, bis [4
-(4-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) phenyl] ether,
Examples thereof include aromatic diamines having four benzene rings such as bis [4- (4-aminophenoxy) phenyl] sulfone and bis [4- (3-aminophenoxy) phenyl] sulfone. Among the aromatic diamines, 4,4′-diaminodiphenyl ether, in consideration of availability, synthesis of the aromatic polyimine oligomer, and solubility of the resulting aromatic polyimine oligomer,
4,4'-diaminodiphenylmethane, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4
-Aminophenoxy) benzene, 3,3'-diaminodiphenyl sulfone, 2,2-bis (4-aminophenyl) propane and 4,4'-bis (4-aminophenoxy) biphenyl are preferred.

First, the method for producing the aromatic polyimine oligomer will be specifically described. The aromatic polyimine oligomer is obtained by subjecting the aromatic dialdehyde represented by the general formula (1) and the aromatic diamine represented by the general formula (2) to a dehydration condensation reaction in the presence of a solvent.

Examples of the solvent include amide solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone and hexamethylphosphotriamide;
Phenolic solvents such as phenol, orthocresol, metacresol, paracresol, resorcinol and the like can be mentioned, and these solvents can be used alone or as a mixture of two or more thereof. In consideration of the odor, toxicity, and irritation of the solvent, amide solvents are preferable among the above solvents.

The molar ratio of the aromatic dialdehyde to the aromatic diamine (aromatic dialdehyde / aromatic diamine) is 0.8 to 1.2, preferably 0.95 to 1.05. When the value of the molar ratio is outside the above range, it tends to be difficult to obtain a desired polymerized product even through the heating and drying step, as described later. Since the reaction between the aromatic dialdehyde and the aromatic diamine is a condensation reaction, it is particularly preferable that the value of the molar ratio is 1.

The reaction temperature of the aromatic dialdehyde and the aromatic diamine is not particularly limited, but is preferably about 10 to 150 ° C., and usually the reaction may be performed at room temperature. The reaction time is not particularly limited as long as the reaction solution becomes uniform, but it is usually preferably about 10 minutes to 12 hours. Incidentally, the concentration of the reaction solution when reacting the aromatic dialdehyde and the aromatic diamine in the presence of the solvent, for example, because it varies depending on the type of aromatic diamine used, it can not be determined unconditionally, If the total amount of the aromatic dialdehyde and the aromatic diamine is too large, the aromatic polyimine oligomer may be precipitated before the heat dehydration treatment for producing the aromatic polyimine described below is performed. Therefore, the total amount is preferably 50% by weight or less of the total amount of the solution, and more preferably 10 to 40% by weight.

The aromatic polyimine oligomer thus obtained has the general formula (3):

[0029]

[Chemical 15]

(Wherein R ¹ , R ² , R ³ and X are as defined above). The infrared absorption IR spectrum (hereinafter referred to as IR) of the solution obtained by drying the solution of the aromatic polyimine oligomer at room temperature and removing the solvent was 3345c.
Characteristic absorptions are shown at m ^-1 (NH of amine), 1680 cm ^-1 (C = O of aldehyde) and 1600 cm ^-1 (C = N of imine).

The solution of the aromatic polyimine oligomer is stable at room temperature for 6 months or longer under sealed condition, and neither precipitation nor gelation is observed. Further, the viscosity (kinematic viscosity) of the solution of the aromatic polyimine oligomer at 30 ° C. is about 5 to 500 cSt, but 7 to 40 in consideration of the ease of handling the solution of the oligomer.
It is preferably about 0 cSt. As described above, the viscosity of the aromatic polyimine oligomer is low even at a high concentration, and the stability with time is good, so that the handleability is good.

The molar ratio of aromatic dialdehyde and aromatic diamine (aromatic dialdehyde and aromatic diamine)
Of the aromatic polyimine oligomer by measuring the nuclear magnetic resonance spectrum (hereinafter, referred to as ¹ H-NMR) of the solution of the aromatic polyimine oligomer obtained by adjusting the value of 1.0 to 1.0. The number average degree of polymerization can be determined. That is, the terminal aldehyde proton signal can be observed at around 10.5 ppm, and the imine proton signal at around 9.0 ppm. From these integrated values, the number average degree of polymerization of the aromatic polyimine oligomer can be calculated based on the following formula. Can be determined.

[Number average degree of polymerization] = 1/2 × {(integrated value of H signal of imine / integrated value of H signal of terminal aldehyde) +1}

The number average degree of polymerization of the aromatic polyimine oligomer obtained as described above varies depending on the kind of the aromatic diamine used and the like, but is usually 2 to 20.
The number average degree of polymerization of the aromatic polyimine oligomer is preferably 3 to 15 in consideration of solubility and stability of the solution of the oligomer.

Next, the method for producing the aromatic polyimine used as the heat-resistant electric insulating material of the present invention will be specifically described. Since the solid content of the reaction product in the reaction solution (the solution of the aromatic polyimine oligomer) is, of course, the aromatic polyimine oligomer, further heating is required to obtain the polymer (aromatic polyimine) from the reaction solution. It is necessary to perform dehydration treatment and heat dehydration condensation under predetermined conditions, but since the melting point of the obtained polymer is very high, usually, a solution of the aromatic polyimine oligomer is formed into a film and subjected to heat dehydration condensation. Is preferred.

For example, when the heat-resistant electric insulating material is used as the heat-resistant electric insulating film, the aromatic polyimine may be produced in the form of a film, and the solution of the aromatic polyimine oligomer obtained above is suitable. It may be cast on a substrate and dried by heating. The temperature for such heat drying is usually 80 to 350 ° C, preferably 100 ° C to 3 ° C.
It is set to 00 ° C. If the temperature is too low, it tends to take a long time to obtain a high molecular weight aromatic polyimine, and if it is too high, thermal decomposition of the aromatic polyimine tends to occur. There is. The heating and drying time varies depending on the heating and drying temperature, but generally, about 2 minutes to 12 hours is suitable. Further, it may be dried under reduced pressure, or may be heated and dried a plurality of times by appropriately changing the heating and drying temperature and the heating and drying time. The coating thickness may be appropriately adjusted depending on the solution concentration of the aromatic polyimine oligomer and the coating amount,
Usually, a material having a thickness of 0.1 to 1000 μm is manufactured according to the use of the heat resistant electrical insulating material. The substrate to be cast is not particularly limited as long as it does not react with the aromatic polyimine oligomer and is not attacked by the solvent. For example, various glass plates can be used.

The aromatic polyimine used as the heat-resistant electric insulating material of the present invention thus obtained has the general formula (3):

[0038]

Embedded image

(Wherein R ¹ , R ² , R ³ and X are the same as above), and their IR is 3345 cm ⁻¹ (N—H of amine) and While absorption at 1680 cm ^-1 (C = O of aldehyde) has disappeared, 1620 cm ^-1 (-CH = N of imine
Absorption of −) is recognized, and it is understood that the polymer has a sufficiently high molecular weight. Also, the aromatic polyimine, for example when dissolved in concentrated sulfuric acid -d2 (D ₂ SO ₄₎ can be measured ¹ H-NMR of the obtained solution, so that, in the vicinity of 8.7ppm The imine (CH = N) signal can be observed.

The intrinsic viscosity of aromatic polyimines soluble in concentrated sulfuric acid, for example, can be measured. The intrinsic viscosity of such aromatic polyimines at 30 ° C. (ηinh, concentration: 0.2 g / cm ³ ) is usually 0.2 to 4. In consideration of mechanical strength such as tensile strength and elongation at break, the intrinsic viscosity is preferably 1 to 4. In addition, some of the aromatic polyimines of the present invention are not completely dissolved in various organic solvents,
It is difficult to measure the molecular weight and viscosity of such substances. Therefore, in such a case, as a physical property in place of the molecular weight of the aromatic polyimine,
This can indirectly define the molecular weight by defining the tensile strength and the elongation at break. Tensile strength is 10
It is 0 to 5000 Kgf / cm ² , and the elongation at break is 0.5 to 100%. Depending on the kind of the aromatic diamine used and the like, if the temperature for heating and drying the solution of the aromatic polyimine oligomer exceeds 200 ° C.,
Crosslinking by heating progresses, and a part of the resulting aromatic polyimine may become insoluble in concentrated sulfuric acid, but in such a case, various physical properties are not particularly impaired, and instead of measuring the intrinsic viscosity. In addition, the tensile strength and the elongation at break can be measured, and each has the same value as described above.

The aromatic polyimine of the present invention is excellent in various electric characteristics and heat resistance and is useful as a heat resistant electric insulating material. That is, as the electrical characteristics of the aromatic polyimine, for example, volume resistivity 1 × 10 ¹⁵ to 1 × 10 ¹⁸ Ω · cm, relative dielectric constant 2.0 to 5.0, dielectric loss tangent 0.001 to 0.05 The dielectric breakdown strength is in the range of 100 to 300 KV / mm, and good electric insulation is exhibited. Usually, volume resistivity 1 × 10
¹⁶ to 1 × 10 ¹⁷ Ω · cm, relative permittivity of 2.5 to 4.5, dielectric loss tangent (dielectric loss) of 0.002 to 0.045, and dielectric breakdown strength of 120 to 300 KV / mm. Also,
The thermal decomposition starting temperature is 300 to 450 ° C, which is excellent in heat resistance. Usually, the thermal decomposition start temperature is 320 to 420 ° C. Furthermore, various base materials including metal (specifically iron,
It has very good adhesion to copper, aluminum, silicon, etc., and is also excellent in bending resistance and surface hardness of the coating film. Aromatic polyimine can be directly cast on these substrates to form a heat-resistant electric insulating film of aromatic polyimine.

The heat-resistant electric insulating material using the aromatic polyimine of the present invention can be used in various applications, for example, prepregs such as multilayer printed boards, enamel wire,
It can be used as a coating agent for electric wires, a battery separator, a coil impregnator, a semiconductor surface protective film, an interlayer insulating film, and the like.

[0043]

According to the present invention, it is possible to provide a heat-resistant electric insulating material which is excellent in various electric characteristics such as electric insulation and heat resistance. Further, the heat resistant electrical insulating material of the present invention has good adhesion to various base materials including metal,
Excellent in flex resistance and coating surface hardness. Further, the heat-resistant electrical insulating material of the aromatic polyimine of the present invention, the viscosity of the oligomer solution is low, and the stability over time is also good,
Easy to handle.

[0044]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

Example 1 1.64 g (0.01 mol) of 2,6-diformyl-4-methylphenol (hereinafter referred to as DFMP) was added to a reactor equipped with a thermometer, a water separation tube, a nitrogen introduction tube and a stirrer. , 4,4′-diaminodiphenyl ether (hereinafter,
DADPE) 2, 0 g (0.01 mol) and N
-Methylpyrrolidone (hereinafter referred to as NMP) 30 ml was added and stirred to dissolve the contents. After dissolution, the reaction starts immediately at room temperature, and the reaction solution (total amount of aromatic dialdehyde and aromatic diamine (hereinafter, referred to as concentration): 1
0.8% by weight) became reddish orange, and the reaction was terminated by further stirring at room temperature for 2 hours to obtain a reaction solution (a solution of an aromatic polyimine oligomer).

The viscosity of the obtained reaction solution and the number average degree of polymerization of the aromatic polyimine oligomer in the reaction solution were examined according to the following methods. The results are shown in Table 2.

(A) Viscosity (aromatic polyimine oligomer): The viscosity (kinematic viscosity) of the solution of the aromatic polyimine oligomer at 30 ° C. was measured using an Ubbelohde viscometer.

(B) Number average degree of polymerization: chloroform-d (CDCl ₃ ) 0.3 with 0.2 ml of a solution of an aromatic polyimine oligomer and a small amount of tetramethylsilane added.
¹ H-NMR was measured with a double sample tube using Bruker's ARX-300 and 10.5 ppm.
The number average degree of polymerization of the aromatic polyimine oligomer was calculated based on the following formula from the integrated value of the terminal aldehyde proton signal observed in 1. and the imine proton signal observed around 9.0 ppm.

[Number average degree of polymerization] = 1/2 × {(integrated value of H signal of imine / integrated value of H signal of terminal aldehyde) +1}

Next, the reaction solution was cast on a glass substrate and left under reduced pressure (1 Torr) at 100 ° C. for 1 hour and then at 200 ° C. for 4 hours to obtain a red-orange film having a thickness of 0.028 mm. The film obtained was tried to be dissolved in various organic solvents, but it could not be completely dissolved, and the molecular weight of the obtained aromatic polyimine could not be measured. Therefore, tensile strength and elongation at break were measured as physical properties in place of the molecular weight according to the following methods. The results are shown in Table 2. In addition, using the obtained film, FTS-7 manufactured by Nippon Bio-Rad Co., Ltd.
The IR was measured by the transmission method at 1620 cm ^-1.
Absorption was observed.

(C) Tensile strength and elongation at break: JI
The method prescribed in SK-7127 was followed. The width of the sample was 10 mm, the length was 50 mm, and the tensile speed was 50 mm / min.

As the characteristics of the obtained film as a heat resistant electric insulating film, the volume resistivity, relative permittivity, dielectric loss tangent, dielectric breakdown strength and thermal decomposition starting temperature were measured by the following methods. The results are shown in Table 3.

(D) Volume resistivity: JIS K 69
It was measured by the method of 11.

(E) Relative permittivity: Measured by the method of JIS K 6911.

(To) Dielectric loss tangent:

(G) Dielectric breakdown strength: JIS K6911
It was measured by the short time method of 5.11.3.

(H) Thermal decomposition start temperature: System 100 manufactured by Mac Science Co., Ltd. Thermogravimetric measurement (TG) using a thermal analyzer was performed at a heating rate of 20 ° C./min.

The reaction solution was cast on a steel plate and dried in an oven at 280 ° C. for 5 minutes under normal pressure to a thickness of 0.0
25 mm was obtained. The film could not be peeled off. The adhesion, flex resistance and pencil scratching value of this coating film were measured by the following methods. The results are shown in Table 4.

(I) Adhesion: JIS K 5400
It was measured by the method of 8.5.2.

(G) Flex resistance: JIS K 5400
It was measured by the method of 8.1.

(L) Pencil scratch value: JIS K 54
00 8.4.2.

Using the obtained film, IR was measured by a transmission method using FTS-7 manufactured by Nippon Bio-Rad Co., Ltd., and absorption was recognized at 1620 cm ^-1 .

Examples 2 to 11 In Example 1, except that the types of aromatic dialdehydes or aromatic diamines or their amounts, or the types of solvents and the concentrations of reaction solutions were changed as shown in Table 1,
A reaction solution (a solution of an aromatic polyimine oligomer) was obtained in the same manner as in Example 1. The (a) viscosity of the obtained reaction liquid and the (b) number average degree of polymerization of the aromatic polyimine oligomer in the reaction liquid were examined in the same manner as in Example 1. The results are shown in Table 2.

Aromatic polyimine films were obtained in the same manner as in Example 1 (the processing conditions during film formation were changed as shown in Table 2). (C) Tensile strength, elongation at break, and electrical insulation characteristics ((d) to (g)) of these films were measured in the same manner as in Example 1. Further, a coating film was formed by the same method as in Example 1, and the coating film physical properties ((ri) to (nu)) were measured in the same manner as in Example 1. The results are shown in Table 2, Table 3 or Table 4. Among the obtained films of aromatic polyimine, those dissolved in concentrated sulfuric acid had a film concentration of 0.
The aromatic polyimine intrinsic viscosity at 30 ° C. was measured with a Ubbelohde viscometer using a solution prepared by dissolving 98% concentrated sulfuric acid so as to have a concentration of 2 g / 100 cm ³ . Further, using the obtained film, FTS- manufactured by Nippon Bio-Rad Co., Ltd.
As a result of measuring IR by the transmission method in Example 7, absorption was recognized at 1620 cm ^-1 in all the films.

[0065]

[Table 1]

In Table 1, DFMP of aromatic dialdehyde:
2,6-diformyl-4-methylphenol, DFP:
2,6-diformylphenol, DFBP: 2,6-diformyl-4-t-butylphenol; DADPE of aromatic diamine: 4,4'-diaminodiphenyl ether, DADPM: 4,4'-diaminodiphenylmethane, 3BABP: 1, 3-bis (4-aminophenoxy) benzene, 4BABP: 1,4-bis (4-aminophenoxy) benzene, DADPS: 3,3′-diaminodiphenylsulfone, BAPP: 2,2-bis (4-
Aminophenyl) propane, BAPBP: 4,4'-bis (4-aminophenoxy) biphenyl; solvent NM
P: N-methylpyrrolidone, MC: metacresol.

[0067]

[Table 2]

[0068]

[Table 3]

[0069]

[Table 4]

Claims (6)

[Claims] 1. General formula (1): (In the formula, R ¹ , R ² and R ³ are each independently a hydrogen atom, an alkyl group or an aryl group, and the total sum of R ¹ , R ² and R ³ is 10 or less) With an aromatic dialdehyde having the general formula (2): (In the formula, X is a single bond, a linear or branched alkylene group having 6 or less carbon atoms, an arylene group, an oxygen atom, a sulfur atom, —SO ₂ —, a general formula: —Y ¹ —Ar—Y ¹ −
(In the formula, Ar is a phenylene group, Y ¹ is a single bond, and has 6 carbon atoms.
The following linear or branched alkylene group, an arylene group, oxygen atom, sulfur atom or -SO ₂ - are shown. ) Or a general formula: —Y ¹ —Ar—Y ¹
An aromatic diamine represented by the formula: —Ar—Y ¹ — (wherein Ar and Y ¹ are the same as defined above), and is represented by the general formula (3): (Wherein R ¹ , R ² , R ³ and X are the same as described above), and an aromatic polyimine oligomer having a number average degree of polymerization of 2 to 20 is subjected to a heat dehydration treatment. The obtained general formula (3): A heat-resistant electrically insulating material comprising an aromatic polyimine having a repeating unit represented by the formula (wherein R ¹ , R ² , R ³ and X are the same as above). 2. The aromatic diamine has 2 to 4 benzene rings.
The heat-resistant electric insulating material according to claim 1, which is an aromatic diamine having a plurality of aromatic diamines. 3. The intrinsic viscosity of the aromatic polyimine is 30 ° C. in a solution of concentrated sulfuric acid having a concentration of 0.2 g / 100 cm ^3.
The heat-resistant electrically insulating material according to claim 1 or 2, wherein the heat resistance is 0.2 to 4. 4. The tensile strength of the aromatic polyimine is 100 to 100.
5000 Kgf / cm ² and elongation at break of 0.5 to
The heat-resistant electrically insulating material according to claim 1, which is 100%. 5. The volume resistivity is 1 × 10 ¹⁵ to 1 × 10.
¹⁸ Ω · cm, relative permittivity 2.0 to 5.0, dielectric loss tangent 0.001 to 0.05, dielectric breakdown strength 100 to 300
The heat resistant electrical insulating material according to claim 1, 2, 3 or 4, which has a KV / mm and a thermal decomposition starting temperature of 300 to 450 ° C. 6. General formula (1): (In the formula, R ¹ , R ² and R ³ are each independently a hydrogen atom, an alkyl group or an aryl group, and the total sum of R ¹ , R ² and R ³ is 10 or less) With an aromatic dialdehyde having the general formula (2): (In the formula, X is a single bond, a linear or branched alkylene group having 6 or less carbon atoms, an arylene group, an oxygen atom, a sulfur atom, —SO ₂ —, a general formula: —Y ¹ —Ar—Y ¹ −
(In the formula, Ar is a phenylene group, Y ¹ is a single bond, and has 6 carbon atoms.
The following linear or branched alkylene group, an arylene group, oxygen atom, sulfur atom or -SO ₂ - are shown. ) Or a general formula: —Y ¹ —Ar—Y ¹
An aromatic diamine represented by the formula: —Ar—Y ¹ — (wherein Ar and Y ¹ are the same as defined above), and is represented by the general formula (3): (Wherein R ¹ , R ² , R ³ and X are the same as above), a varnish of an aromatic polyimine oligomer having a number average degree of polymerization of 2 to 20 is cast, General formula (3), characterized by being heated and dehydrated: (In the formula, R ¹ , R ² , R ³ and X are the same as described above) A method for producing a heat resistant electric insulating film comprising an aromatic polyimine having a repeating unit represented by the formula.