JP2001261824A - Polyimide and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide excellent in hydrolysis resistance and having a low ionic impurities concentration and a method which can produce the same directly without the necessity for passing through a polyamic acid. SOLUTION: At least one first acid dianhydride is reacted with at least one first diamine in a heated polar solvent, then, at least one second acid dianhydride and at least one second diamine are added to the reaction system, and the reaction is caused to proceed. The reaction is carried out in the presence of a lactone polymerization catalyst, thus enabling the direct imidization to be realized. The resultant polyimide has a wt. average mol.wt. of 20,000-150,000 and an ionic impurities concentration of 0.1 ppm or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide and a method for producing the same, and more particularly, to a polyimide having excellent hydrolysis resistance and a low concentration of ionic impurities, and a method for producing the same.

[0002]

2. Description of the Related Art Polyimide has excellent heat resistance and electrical insulation properties, and also has excellent physical properties such as mechanical strength and mechanical elongation. It is used in a wide range of applications, including adhesives for parts materials and film materials.

[0003] This polymer is usually synthesized using one kind of acid dianhydride and one kind of diamine as raw materials. First, an equimolar amount of acid dianhydride and diamine are reacted in a low-temperature polar solvent to produce an intermediate. It is usually produced by producing a polyamic acid in a solid form, then subjecting it to a chemical treatment such as heat treatment or addition of acetic anhydride to thereby effect dehydration ring closure and imidization.

[0004] The polyimide thus obtained does not have a softening temperature for molding and is insoluble in solvents, so that molding such as casting must be performed at the stage of polyamic acid. However, polyamic acid is an unstable polymer, and this instability often impairs various properties inherent to polyimide.

[0005] For this reason, in order to ensure the characteristics, the molecular constitution is changed to an alternating copolymerization type or a block copolymerization type. As an example of this, for example, a production method disclosed in JP-A-60-166326 is known, in which an oligomer of sulfonamide is first produced, and then an acid dianhydride is added thereto. A method for forming a block polyimide is shown.

In Japanese Patent Application Laid-Open No. Hei 1-21165, 1 mole of diamine and 1.5 to 2.0 moles of acid dianhydride are added to a polar solvent and reacted at a low temperature to produce an amide acid oligomer. A method is disclosed in which a polyimideamide carboxylic acid is prepared by reacting an isocyanate with an equivalent amount thereof, and then cast and heated to obtain a high-performance polyimide film.

Further, according to JP-A-2-91224, a siloxane-amide acid block copolymer is synthesized by adding an acid dianhydride to a diaminosiloxane copolymer, and an equivalent amount of a diamine is added thereto to obtain a polyamic acid. Is produced, and a method of obtaining a siloxane-imide block copolymer by heat or chemical treatment is disclosed.

Further, Japanese Patent Application No. 4-50579 discloses a method for obtaining a resin composition from bicyclooctene-tetracarboxylic dianhydride and a bismaleimide compound via a polyamic acid. Kaihei 64-1683
JP-A No. 1-21165 and JP-A 1-211165, after adding an excess or an insufficient amount of an acid dianhydride to an aromatic diamine and reacting the resultant to produce a polyamic acid prepolymer, and then adding a shortage of a diamine to obtain a polyamic acid. A method of obtaining a polyimide copolymer by forming a copolymer and then subjecting it to heat or chemical treatment is disclosed.

JP-A-4-306232 discloses a method for obtaining a polymer precursor having an amic acid segment. The precursor is composed of first and second segments, each segment being obtained from a different diamine and an acid anhydride, the product of amic acid, which is imidized to the extent that the amic acid exchange reaction does not occur. Blocked polymers are shown.

However, although the polyimides obtained by the above prior arts can be expected to have improved properties compared to homopolymer type polyimides, all of them involve the use of polyamic acid, and therefore, the instability inherent in polyamic acid. Has not been released yet. That is, the polyamic acid is apt to be broken in the molecular chain due to the water produced at the time of imidization, so that recondensation occurs at the stage of imidization, and random polymerization that deteriorates the characteristics is likely to occur.

Polyamide acid has the property that the exchange of acid amide groups between molecules proceeds easily and quickly. Therefore, even if two different block polymers are bonded, the polyamide acid formed is There is a problem that an acid exchange reaction cannot be prevented and a random block polymer having poor purity tends to be formed.

US Pat. No. 5,502,143 is known as a method for producing a polyimide without passing through a polyamic acid which adversely affects the above-mentioned properties. Γ- as a catalyst
Using valerolactone, a polyimide oligomer is first produced from a first acid dianhydride and a diamine, and then blocked by adding and reacting a second and third acid dianhydride with a diamine. It is for producing a polymer, and a polyimide can be directly produced by a one-step reaction without going through a polyamic acid.

[0013]

However, according to the conventional polyimide obtained by direct imidization, since the molecular structure is a copolymer having three components, the physical and chemical properties are regulated by the three components. Therefore, the chemical and physical properties are not sufficient, and in particular, they do not have satisfactory properties in terms of hydrolysis resistance which is regarded as important in applications of electronic component materials. In addition, many of the polyimides cited above have a problem that the concentration of ionic impurities contained therein is high, and this problem undesirably acts when applied to electronic component material applications.

Accordingly, an object of the present invention is to provide a polyimide having excellent hydrolysis resistance and a low concentration of ionic impurities, and a process for producing this polyimide directly without passing through polyamic acid. It is in.

[0015]

In order to achieve the above object, the present invention comprises a copolymer of four or more components obtained from two or more acid dianhydrides and two or more diamines.
A weight average molecular weight of from 0.001 to 150,000;
An object of the present invention is to provide a polyimide characterized by having an ionic impurity content of 1 ppm or less.

In order to achieve the above object, the present invention provides a method for producing a polyimide, comprising reacting an acid dianhydride with a diamine, wherein at least one kind of the first acid dianhydride is heated in a polar solvent. And at least one of the first diamines in the presence of a lactone-based polymerization catalyst.
A reaction solution containing a polyimide directly imidized without passing through a polyamic acid by adding at least one kind of a second diamine and at least one kind of a second diamine and continuously reacting in a polar solvent heated under a lactone polymerization catalyst. And a method for producing a polyimide characterized by obtaining

The first and second acid dianhydrides constituting the two or more acid dianhydrides are bicyclo (2,2,2) oct-7- represented by the following formula (I). Ene-2,3,5,6 tetracarboxylic dianhydride (hereinafter referred to as B
CD), or 3, represented by the formula (II)
It is preferable to use 4,3,4-biphenyltetracarboxylic dianhydride (hereinafter abbreviated as BPDA). Further, as the first and second diamines constituting the above two or more kinds of diamines, 3,4-diaminodiphenyl ether (hereinafter, referred to as DA) represented by the following formula (III)
DE), or 1, represented by formula (IV)
3-bis (3-aminophenoxy) benzene (hereinafter referred to as A
PB).

[0018]

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[0019]

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[0020]

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[0021]

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The polyimide of the present invention is characterized by being a block copolymer of four or more components, and can be obtained by conventional two-component or three-component polymerization by combining at least four components. It gives Holima the properties of mutual complementation due to no multi-components, thereby making the polyimide excellent in overall properties. In particular,
Excellent properties in hydrolysis resistance are obtained.

In the present invention, the weight average molecular weight is 20,
The reason for limiting to 20,000 to 150,000 is 20,000
If it is 0 or less, hydrolysis resistance and heat resistance will be insufficient, and sufficient film formability when formed into a varnish cannot be obtained. Conversely, if it exceeds 150,000, the varnish state This is due to the fact that storage stability is inferior because gelation is likely to occur, and furthermore, adhesion to copper foil, which is important as a material for electronic components, is insufficient. The concentration of the ionic impurities is characterized by being 0.1 ppm or less, which gives characteristics suitable for electronic component materials.

In the production method of the present invention, the reaction between the first acid dianhydride and the diamine in a heated polar solvent under a lactone polymerization catalyst, and the subsequent reaction with the second acid dianhydride Polyimide is directly polymerized by advancing the reaction of the diamine, and as a result, breakage of the molecular chain via the polyamic acid, random polymerization, and the like are prevented.

As the polar solvent, one kind of N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, sulfolane, anisole, dioxolane, bityrolactone and the like are used, or two or more kinds are used in combination. As the lactone polymerization catalyst, γ-valerolactone, γ-butyrolactone, γ-tetronic acid, γ-phthalide, γ-coumarin, or γ-phthalidic acid and the like and pyridine, quinoline, and bases such as N-methylmorpholine A mixture is used. In many cases, the mixing ratio is set such that the latter has a molecular weight ratio of 1/1 to 1/3 of the former.

The ratio of the polyimide solid content of the reaction solution obtained by the production method of the present invention is preferably set to 10 to 50% by weight. When the amount is less than 10% by weight, the film-forming property is poor. On the other hand, when the amount exceeds 50% by weight, the progress of the polyimide formation reaction becomes difficult due to a lack of solvent. Further, the first and second acid dianhydrides and the first and second diamines are used in an amount of 0.95 to 1.05 with respect to 1 mol of the former.
It is preferable to carry out the reaction within the molar range. If the ratio is out of this range, the characteristics will be deteriorated due to the imbalance in the molar ratio.

The reaction solution obtained by the production method of the present invention can be used as it is as a varnish. For example, an adhesive for laminating a polyimide base tape and a copper foil on a TAB tape or an insulating film material is formed. It is used as a stock solution for film formation and can constitute a good electronic component material because of its excellent hydrolysis resistance and low ionic impurity content. In addition, 1
Since the varnish (reaction liquid) is directly produced at the stage, the desired solid content can be adjusted from the stage of charging the raw materials, and further, since imidization is completed at the varnish stage, the storage stability is excellent. It has the advantage of providing a varnish.

[0028]

Next, an embodiment of the polyimide and the method for producing the same according to the present invention will be described.

Example 1 A reaction tank was constructed by attaching a cooling tube with a ball equipped with a trap with a silicon cock to a 1000-ml separable three-necked flask equipped with a stirrer. 7.45 g of BCD, 9.01 g of DADE of the formula (III), 1.0 g of γ-valerolactone, 1.66 g of pyridine, 100 g of N-methylpyrrolidone (hereinafter abbreviated as NMP), and toluene 20
After stirring for 10 minutes at room temperature under a nitrogen gas atmosphere, the content of the reaction vessel was heated to 180 ° C., and the reaction was performed for 1 hour at a rotation speed of a stirrer of 180 rpm.

Next, after the reaction solution was air-cooled, 22.07 g of BPDA of the formula (II) and AP of the formula (IV) were added to the reaction solution.
B 17.54 g, NMP 120 g, and toluene 24
g was added, and a stirring reaction was performed for 5 hours while the temperature was raised to 180 ° C. again. During this time, the rotation speed of the stirrer is
The water was gradually reduced from 80 rpm as the reaction decreased, while the water formed was excluded from the silicone cock.

Next, a part of the reaction solution (varnish) obtained as described above was poured into an excess methanol solution, and the mixture was stirred with a mixer to precipitate a resin powder. Next, this powder was washed with methanol, dried at room temperature, and dried at 150 ° C. under reduced pressure to obtain a dry powder. The infrared absorption spectrum was measured using MFT2000 manufactured by JASCO Corporation. 1365cm-1, 1721cm
Characteristic absorption of imide was observed in each band at -1 and 1780 cm-1.

After the varnish obtained by the reaction is cast on a glass substrate as it is and dried at a temperature of 150 ° C., the film is peeled off and heat-treated at 250 ° C. to obtain a tough film. did it. The varnish was heated at 250 ° C. for 2 hours and its solids content was determined to be 20.5% by weight.

[0032]

Example 2 The reaction vessel used in Example 1 was charged with BCD 7.4.
5 g, DADE 9.01 g, γ-valerolactone 1.0
g, pyricine 1.66 g, NMP 60 g, and toluene 12 g, stirred at room temperature for 10 minutes in a nitrogen gas atmosphere, and then heated to 180 ° C. to rotate at 180 rpm
and stirred for 1 hour.

Next, the obtained reaction solution was air-cooled,
22.07 g of BPDA, 17.54 g of APB, NMP5
0 g and 10 g of toluene were added, and the temperature of the solution was adjusted to 1 again.
The temperature was raised to 80 ° C., and the reaction was carried out for 4.5 hours while removing generated water from the silicon cock. The rotation speed of the stirrer was initially set at 180 rpm, and was decreased as the reaction decreased.

Next, a dried resin powder was obtained by using the same procedure as in Example 1 by using a part of the varnish as a reaction solution obtained above, and the infrared absorption spectrum was measured. The characteristic absorption of the imide was confirmed in the same band as 1. Further, it was confirmed that a tough film was obtained by the same procedure as in Example 1. Further, when the solid content in the varnish as a reaction liquid was confirmed by the same method as in Example 1, it was 35.0% by weight. Was obtained.

[0035]

Example 3 The reaction vessel of Example 1 was charged with 7.45 g of BCD and D
After adding 9.01 g of ADE, 1.0 g of γ-valerolactone, 1.66 g of pyridine, 40 g of NMP and 8 g of toluene, and stirring at room temperature and under a nitrogen gas atmosphere for 10 minutes, the temperature of the contents in the reaction vessel was heated to 180 ° C. Raise the temperature,
The rotation speed of the stirrer was set at 180 rpm, and the mixture was stirred for 1 hour.

Next, the obtained reaction solution was air-cooled, and 22.07 g of BPDA, 17.54 g of APB, NMP3
0 g and 6 g of toluene were added, and the solution was heated to 180 ° C. and reacted for 3 hours. The initial rotation speed of the stirrer is 1
The reaction was proceeded while the rotation speed was reduced as the reaction was set at 80 rpm and the generated water was removed from the silicon cock while the reaction was reduced.

Next, using a part of the varnish obtained as described above, a dry resin powder was obtained in the same procedure as in Example 1, and the infrared absorption spectrum of this powder was measured. The absorption characteristics of the imide were confirmed. Further, it was confirmed that a tough film was obtained by the same procedure as in Example 1. Further, when the solid content in the varnish was examined, a result of 45.0% by weight was obtained.

[0038]

Comparative Example 1 The reaction vessel used in Example 1 was charged with BCD.
7.45 g, 9.01 g of DADE, 1.0 g of γ-valerolactone, 1.66 g of pyridine, 120 g of NMP and 20 g of toluene, and 1 g at room temperature and under nitrogen gas.
After stirring for 0 minutes, the liquid temperature was raised to 180 ° C., and stirring was performed for 1 hour while setting the rotation speed of the stirrer to 180 rpm.

Next, the reaction solution was air-cooled and BPD
A22.07g, APB 17.54g, NMP120
g, and 24 g of toluene were added, and the temperature was raised again to 180 ° C. and reacted for 3 hours. The number of revolutions of the stirrer was reduced from the initial 120 rpm in accordance with the decrease in the reaction, and the reaction proceeded while removing the generated water from the silicon cock.

The varnish as a reaction solution obtained was cast on a glass substrate as it was, dried at 150 ° C., and then the film was peeled off. The film was cut off during the peeling process, making it difficult to produce a film. there were. This is due to insufficient reaction. The solids content in this example was 19.5% by weight.

[0041]

Comparative Example 2 The reaction vessel of Example 1 was charged with 7.45 g of BCD and D
ADE 9.01 g, γ-valerolactone 1.0 g, pyridine 1.66 g, NMP 15 g, and toluene 3 g were added, and the mixture was stirred at room temperature and under a nitrogen gas for 10 minutes. Then, the liquid temperature was raised to 180 ° C. 180 rpm
m and stirred for 1 hour.

Next, the reaction solution was air-cooled, and 22.07 g of BPDA and APB17.
After adding 54 g, 15 g of NMP and 3 g of toluene, the temperature was raised again to 180 ° C.
The reaction was attempted at a setting of rpm, but the reaction was stopped because a sufficient dissolved state could not be obtained. The cause is due to excess solids.

[0043]

[Prior art 3] Varnish "Likacoat PN2" manufactured by Shin Nippon Rika Co., Ltd.
0 "(two-component system using 3,3 ', 4,4'-diphenylsulfone-tetracarboxylic dianhydride as acid dianhydride) was cast on a glass substrate and dried at 150 ° C. A film was obtained by performing a heat treatment at ℃.

Table 1 shows the results of characteristic tests performed using the films and varnishes obtained in the above Examples, Comparative Examples and Conventional Examples. The test method is as follows. ◇ Weight average molecular weight Using varnish of each example, TSK gel G manufactured by Tosoh Corporation
The measurement was performed using a MHHR-M type gel column and a UV-8020 type detector.

(4) Glass transition point Using a thermomechanical analyzer TMA120 manufactured by Seiko Denshi Kogyo Co., Ltd., 8 g using a cylindrical quartz probe as a test film.
At a temperature rise rate of 10 ° C./min.
It was measured within the range of 00 ° C.

◇ 1% thermogravimetric reduction temperature Simultaneous thermogravimetric analyzer TG /
Using DTA320, in nitrogen or air, 100
Thermal analysis was performed from normal temperature to 700 ° C. at a temperature rising rate of 10 ° C./min at a flow rate of ml / min, and the temperature at which the weight decreased by 1% was determined.

(4) Coefficient of thermal expansion For a sample film cut into a width of 4 mm and a length of 20 mm, from a normal temperature to 300 ° C. under the conditions of a tensile force of 5 g and a temperature rising rate of 10 ° C./min using a tensile quartz probe. Was measured in the temperature range of As a measuring device, a thermomechanical analyzer TMA120 manufactured by Seiko Denshi Kogyo was used.

(4) Volume resistivity A sample was set in a specific resistance cell manufactured by Hewlett-Packard Company, and the volume was measured from the current value after applying 100 V DC for 1 minute using a high insulation resistance meter 4329A manufactured by Yokogawa Hewlett-Packard Company. The resistivity was determined.

{Ionic impurity content concentration} A sample film cut to a width of 50 mm and a length of 100 mm was immersed in 50 ml of ultrapure water placed in a 100 ml stainless beaker, and dried at 100 ° C. × 0.5 in a drier. After the heat extraction for a period of time, the extracted solution is subjected to an ion chromatography analyzer IC7000 manufactured by Yokogawa Analytical Systems.
Was used to determine the concentration of ionic impurities of Na +, Cl-, N03- and SO4-.

(5) Water supply rate A film sample cut into a width and a length of 10 mm
After drying in a dryer at 0 ± 3 ° C. for 30 minutes and cooling to room temperature in a desiccator, place in a weighing bottle, seal and measure the weight (W1). Next, this sample was immersed in pure water at 23 ° C. for 24 hours, and then the attached water on the surface was wiped off.
It was put in a weighing bottle, sealed, and the weight (W2) after water absorption was measured. Water absorption = (W2−W1) × 100 / W1

(5) Storage elastic modulus A dynamic viscoelasticity measuring device DVA-200 manufactured by IT Measurement Control Co., Ltd. is used for a sample film having a width of 4 mm and a length of 25 mm.
The measurement was performed under the conditions of a frequency of 10 Hz, a heating rate of 3 ° C./min, and a measurement range of room temperature to 300 ° C.

◇ Gas generation amount Using a sample heating gas generator manufactured by GL Sciences,
The amount of gas generated after heating at 350 ° C. for 5 minutes was measured by gas chromatography G3000 manufactured by Hitachi, Ltd.

(5) TAB tape hydrolysis resistance A varnish of each example was applied to UPILEX 50SGA (polyimide base tape) manufactured by Ube Industries, Ltd. using a coating apparatus manufactured by Yasui Seiki Co., Ltd., and dried. After forming an adhesive film layer having a thickness of 20 μm on one surface of the base tape, a thickness of 1 μm was formed on the surface of the adhesive film layer using a test laminator MT-300 manufactured by MC Kay Corporation.
8μm electrolytic copper foil is laminated (lamination temperature 200 ° C),
A hydrolysis resistance test (PCT test) was performed on the TAB tape obtained as described above. The test method is as follows.

PCT test Pressure cooker tester PC-2 manufactured by Hirayama Seisakusho
Up to 121 ° C on TAB tape using 42HS-A
168 hours of wet heat treatment, 90 ° peel strength of polyimide tape and electrolytic copper foil before and after wet heat treatment (JIS
(Measured according to C6481). As a peel strength tester, Tensilon MPW manufactured by Orientec
-300S was used.

[0055]

[Table 1]

According to Table 1, the case of Examples 1 to 3 is
In the hydrolysis resistance of the AB tape, the peel strength after the wet heat treatment shows a residual rate of 38 to 44% before the treatment, whereas the residual rate of the conventional example is only 6%, and the present invention shows that The effect of improving the hydrolysis resistance clearly appears. Also,
Regarding the concentration of ionic impurities, the prior art also
1- show high concentrations of 0.14 ppm and 0.09 ppm, respectively.
a + is 0.04 ppm and Cl− is 0.02 to 0.0
The level is as low as 3 ppm, and its usefulness in application to electronic component material applications is apparent.

In the case of Comparative Example 1, although it was difficult to form a film and all the tests could not be performed, it was noted that the weight average molecular weight was 18,000 among the measured items that could be performed. In the present invention, the copolymer of four or more components, particularly, the lower limit of the weight average molecular weight is 2
The reason for setting the value to 0000 is supported by Comparative Example 1.

[0058]

As described above, according to the polyimide and the method for producing the same according to the present invention, the polyimide comprises four or more copolymers obtained from two or more acid dianhydrides and two or more diamines, Moreover, 20,000 to 150,000
The present invention provides a polyimide suitable for electronic component materials characterized by a weight average molecular weight of 0.1 and an ionic impurity content of 0.1 ppm or less, and its usefulness is great. In addition, according to the production method of the present invention, since the imidization is performed directly without passing through the polyamic acid, it is possible to provide a polyimide which is free from random chain polymerization without breaking molecular chains.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahiro Okabe 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture Power Systems Research Laboratory, Hitachi Cable, Ltd. (72) Inventor Shigehiro Morishita 5 Hidaka-cho, Hitachi City, Ibaraki Prefecture 1-1-1 Hitachi Power Systems Co., Ltd. (72) Inventor Kenji Asano 5-1-1 Hidaka-cho, Hitachi City, Ibaraki Pref. Power Systems Research Laboratory, Hitachi Cable Co., Ltd. (72) Shunichi Matsumoto Kanagawa Prefecture 1-1-1 Fukuura, Kanazawa-ku, Yokohama 5F Yokohama Kanazawa High-Tech Center Building 5F Inside PII Technical Research Institute (72) Inventor Hiroshi Itaya 1-1-1 Fukuura Fukuura Kanazawa-ku, Yokohama-shi, Kanagawa 5F Yokohama F term in the Technical Research Institute (reference) 4J043 PA06 PA08 QB26 QB31 RA35 R A37 SA06 SB03 TA22 TB03 UA082 UA131 UA132 UA141 UB121 UB131 UB402 VA011 VA051 VA062 VA071 XA03 XA13 XA16 XA19 XB17 XB34 XB35 ZA12 ZA31 ZA46 ZB01 ZB11 ZB50

Claims (5)

[Claims] 1. A copolymer comprising four or more components obtained from two or more acid dianhydrides and two or more diamines.
Weight average molecular weight of 000 to 150,000 and 0.1 p
A polyimide having an ionic impurity-containing concentration of pm or less. 2. A method for producing a polyimide, comprising reacting an acid dianhydride with a diamine, comprising: heating one or more of the first acid dianhydride and one or more of the first diamine in a heated polar solvent; After reacting under a polymerization catalyst, one or more of a second acid dianhydride and one or more of a second diamine are added, and the mixture is continuously heated in a polar solvent heated under a lactone-based polymerization catalyst. A method for producing a polyimide, characterized by obtaining a reaction solution containing a polyimide directly imidized without passing through a polyamic acid by reacting. 3. The first and second acid dianhydrides are different acid dianhydrides selected from the formula (I) or (II), and the first and second diamines are: The method for producing a polyimide according to claim 2, wherein the diamines are different diamines selected from the formula (III) or the formula (IV). Embedded image Embedded image Embedded image Embedded image 4. The method according to claim 2, wherein the amount of the polar solvent is adjusted so that the solid content of the reaction solution is 10 to 50% by weight. 5. The method according to claim 1, wherein the first and second diamines are contained in an amount of 0.95 to 1.1 per mole of the first and second acid dianhydrides.
The method for producing a polyimide according to claim 2, wherein the polyimide is used within a range of 05 mol.