JPH02178328A - Production of polyimide having good thermal stability - Google Patents

Abstract

PURPOSE:To provide the subject polymer having good thermal stability and excellent moldability as well as the original excellent characteristics by condensing a specific aromatic diamine with a tetracarboxylic acid dianhydride under a specified condition. CONSTITUTION:An aromatic diamine comprising bis{4-[4-(4-aminophenoxy) phenoxy]phenyl}sulfone of formula I is condensed with a tetracarboxylic acid dianhydride (e.g. pyromellitic acid dianhydride) of formula II (R is a tetravalent group selected from >=2C aliphatic groups, monocyclic aromatic groups, etc.) in a ratio of 0.9-1mol of the compound of formula I per mol of the compound of formula II in the presence of an aromatic monoamine (e.g. aniline) of formula: Z-NH2 (Z is a monovalent group selected from monocyclic aromatic groups, condensed polycyclic aromatic groups, etc.) in an amount of 0.001-1mol per mol of the compound of formula II to provide the objective polymer having units of formula III as the basic skeleton thereof.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a polyimide resin for melt molding.

More specifically, the present invention relates to a method for producing polyimide having good thermal stability and excellent moldability.

[Prior art] Polyimide obtained by the reaction of tetracarboxylic dianhydride and diamine has not only high heat resistance, but also excellent mechanical strength, -1 method stability, flame retardancy, electrical insulation, etc. Electrical and electronic equipment, aerospace equipment,
It has been used in fields such as transportation equipment, and it is expected that it will be widely used in fields that require co-thermal properties in the future.

Various polyimides have been developed that exhibit excellent properties.

However, even if it has excellent thermal properties, it does not have a clear glass transition temperature, so when used as a molding material, it must be processed using methods such as sintering, and whether it has excellent processability. The glass transition temperature is low;
Moreover, it is soluble in halogenated hydrocarbons, and its heat resistance and solvent resistance are unsatisfactory.

On the other hand, the present inventor first proposed a polyimide of the following formula (IV) (wherein R is carbon aliphatic group of number 2 or more, cycloaliphatic group, monocyclic aromatic group,
It represents a tetravalent group selected from the group consisting of a fused polycyclic aromatic group and a non-fused polycyclic aromatic group in which aromatic groups are interconnected directly or through a bridge member. ) We have discovered a polyimide having repeating units represented by (Japanese Unexamined Patent Publication No. 62-50372). The above polyimide is a new heat-resistant resin having many good physical properties.

However, the above polyimide exhibits excellent fluidity,
Although polyimide has good processability, if it is kept at high temperatures for a long period of time (for example, if it is left in a cylinder at high temperature for a long time during injection molding), it may deteriorate. The fluidity of the molten resin decreases, resulting in a decrease in moldability.

[Invention or Problem to be Solved] The purpose of the present invention is to create an excellent polyimide which, in addition to the excellent properties originally possessed by polyimide, also has good thermal stability and does not deteriorate in moldability even when kept at high temperatures for long periods of time. The purpose is to provide a method for manufacturing.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors conducted extensive research and completed the present invention. That is, the present invention provides a method for producing polyimide, which involves reacting an aromatic diamine with a tetracarphonic acid anhydride and thermally or chemically imidizing the obtained polyamic acid. or aromatic diamine represented by the following formula (I); (b) tetracarboxylic dianhydride or the following formula (rl) (I
I) (wherein R is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group,
Represents a tetravalent group selected from the group consisting of a monocyclic aromatic group, a fused polycyclic aromatic group, and a non-fused polycyclic aromatic group in which aromatic groups are interconnected directly or through a bridge member. , ) is a tetracarboxylic dianhydride represented by (c)
Further, the reaction is carried out by the following formula (III) Z-MHI (m) (wherein Z is an m-cyclic aromatic group, a fused polycyclic aromatic group), Represents a monovalent group selected from the group consisting of non-fused polycyclic aromatic groups. ) The amount of the aromatic diamine is 0.9 to 1.0 molar ratio per mole of tetracarboxylic dianhydride, and the aromatic diamine is Formula (IV) characterized in that the amount of monoamine is in a molar ratio of o, oot to 10 per mole of tetracarboxylic dianhydride (wherein R is as defined in formula (II)). This is a method for producing a polyimide having good thermal stability and having the repeating unit shown as a basic skeleton.

The aromatic diamine represented by formula (I) used in the method of the present invention is bis(4-[4-(4-aminophenoxy)phenoxy]phenyl)sulfone.

Note that there is no problem in replacing a part of the aromatic diamine with another diamine as long as the good physical properties of the polyimide obtained by the method of the present invention are not impaired.

Examples of diamines that can be used as partial substitutes include m-phenylenediamine, 0-phenylenediamine, p-phenylenediamine, m-aminobenzylamine,
p-aminobenzylamine, bis(3-aminophenyl) ether, (3-aminophenyl)(4-aminophenyl) ether, bis(4-aminophenyl) ether,
Bis(3-aminophenyl) sulfide, (3-aminophenyl)(4-aminophenyl) sulfite, bis(
4-aminophenyl) sulfite, bis(3-aminophenyl) sulfoxide, (3-aminophenyl)(4-
Aminophenyl) sulfoxide, bis(4-aminophenyl) sulfoxide, bis(3-aminophenyl) sulfone, (3-aminophenyl)(4-aminophenyl) sulfone, bis(4-aminophenyl) sulfone, 3゜3
゛-Diaminobenzophenone, 3,4°-diaminobenzophenone, 4,4°-diaminobenzophenone, bis[4-(4-aminophenoxy)phenylcomethane, 1
．． 1-bis[4-(4-aminophenoxy)phenyl]
Ethane, 1,2-bis[4-(4-aminophenoxy)phenyl]ethane, 2,2-bis[4-(4-aminophenoxy)phenyl]furopane, 2,2-bis[4-(4-aminophenoxy)phenyl]furopane,
-aminophenoxy)phenylcobutane, 2,2-bis[4-(4-aminophenoxy)phenyl] -1,1
,1,:l,3.3-hexafluoropropane, 1.3
-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(
3-aminophenoxy)benzene, 1,4-bis(4-
aminophenoxy)benzene, 4.4゛-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenylkoketone, bis[4-(4-aminophenoxy)phenyl]sulfite, bis[4 -(4
-aminophenoxy)phenyl] sulfoxide, bis[
4-(4-aminophenoxy)phenylcosulfone, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenylcony-
Chil, 1,4-bis(4-(3-aminophenoxy)benzoyl]benzene, l,3-bis[4(3-aminophenoxy)benzoyl]benzene, bis[4-(3-aminophenoxy)phenylcomethane) , 1.1-bis[4
-(3-aminophenoxy)phenyl]ethane, 2.2
-bis[4-(3-aminophenoxy)phenyl]propane, 2-[4-(3-aminophenoxy)phenyl]-2-[4-(3-aminophenoxy)-3-methylphenyl]propane, 2, 2-bis[4-(3aminophenoxy)-3-methylphenyl]furopane, l-[1
-(3-aminophenoxy)phenyl] -2-(1(
3-aminophenoxy)-],]5-dimethylphenyl]propane 12□2bis[1-(3-aminophenoxy)-3,5-dimethylphenyl]propane, 2.2-bis[1-(3aminophenoxy) phenyl]phthane, 2
．． 2-[bis-4-(3-aminophenoxy)phenyl] -1,1,1,:1,3. :I-hexafluoropropane 4.4'-bis(3-aminophenoxy)biphenyl, 4.4'-bis(3-aminophenoxy)-3
=Methylbiphenyl, 4.4°-bis(3-aminophenoxy)-3,:l'-dimethylbiphenyl, 4,4°
-Bis(3-aminophenoxy)-: l, 5-dimethylbiphenyl, 4,4'-bis(3-aminophenoxy)
3.1',5.5'-tetramethylbiphenyl, 4,4
'bis(3-aminophenoxy)-3j-dichlorobiphenyl, 1,4'-bis(3-aminophenoxy 1-L
5'-dichlorobiphenyl, 4.4'-bis(3-aminophenoxy)-3,3', 5.5'-tetrachlorobiphenyl, 4,4°-bis(3-aminophenoxy)-3,3' -dibromobiphenyl, 4,4'-bis(3-aminophenoxy)-1,S-dibromobiphenyl, 4,4'-bis(3-aminophenoxy)-3,3
°, 5.5'-tetrabromobiphenyl, bis[4-(
3-aminophenoxy)phenylkoketone, bis[4-
(3-aminophenoxy)phenyl] sulfite, bis[4-(3-aminophenoxy)-3-methoxyphenyl] sulfide, [4-(3-aminophenoxy)phenyl][4-(3-aminophenoxy)-: l,5-dimethoxyphenyl] sulfide, bis[4-(3-aminophenoxy)-3,5-dimethoxyphenyl] sulfide, bis[4-(3-aminophenoxy)phenyl]
Examples include sulfone, which may be used in combination or in combination of two or more.

Further, examples of the tetracarboxylic dianhydride represented by formula (II) used in the method of the present invention include ethylenetetracarboxylic dianhydride, tutante 1 heracarboxylic dianhydride, and cyclobentaneputracarboxylic dianhydride. Anhydride, pyromellitic dianhydride +4-bis(2,]-dicarboxyphenyl)ethane dianhydride, bis(2, cosicarboxyphenyl)methane dianhydride, bis(1,4-
dicarboxyphenyl)methane-anhydride, 2,2-bis(3,4dicarboxyphenyl)brovani anhydride, 2
゜2-bis(2,3-dicarboxyphenyl)brovani anhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,:l,:l,3-hexafluoropropane di anhydride, 2,2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,:l-hexainanimate lopropane-anhydride,:l,3',4.4'- Benzophenone tetracarboxylic dianhydride, 2.2°, :l
,]'-benzophenonetetracarboxylic dianhydride,
3.3', 4.4'-biphenylde 1-lacarboxylic dianhydride, 2.2', ], 'l' biphenyltetracarboxylic dianhydride, anhydride (3,4-dicarboxyphenyl) Ether dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 4.4'-(P-
phenylenedioxy) cyphthalic dianhydride, 4.4'
-(m-phenylenedioxy)cyphthalic dianhydride, 2
, 1,5゜7-naphthalenetetracarboxylic dianhydride,
1,4゜5.8-naphthalenetetracarboxylic dianhydride, 1.2. S, 5-naphthalenetetracarboxylic dianhydride, +, 2,3.4-benzenetetracarboxylic dianhydride, :I, 4,9.10-perylenetetracarboxylic dianhydride, 2.3,6. These include 7-anthracenetetracarboxylic dianhydride, 1,2,7.8-phenanthrenetetracarboxylic dianhydride, and the like, and these tetracarboxylic dianhydrides may be used alone or in a mixture of two or more.

Further, aromatic monoamines represented by formula (m) used in the method of the present invention include aniline, o-toluidine, m-toluidine, p-toluidine, 2,3-xylidine, 2,4-xylidine, 2.5-xylidine, 2
．． 6-xylidine, 3.4-xylidine, 3.5-xylidine, 0-chloroaniline, m-chloroaniline, p
-chloroaniline, 0-solomoaniline, m-bromoaniline, p-fluoroaniline, 0-nitroaniline, m-
Nitroaniline, p-nitroaniline, 0-aminophenol, m-aminophenol, p-aminophenol, 0-anisidine, m-anisidine, p-anisidine,
0-phenetidine, m-phenetidine, p-phenetidine, 0-aminobenzaldehyde, m-aminobenzaldehyde, p-aminobenzaldehyde, 0-aminobenzotrifluoride 1m-aminobenzotrifluoride, P-aminobenzotrifluoride, 0-aminobenzonitrile, m-aminobenzonitrile, p-aminobenzonitrile, 2-aminobiphenyl, 3-aminobiphenyl, 4-aminobiphenyl, 2-aminophenyl phenyl ether, 3-aminophenyl phenyl ether,
4-aminophenyl phenyl ether, 2-aminobenzophenone, 3-aminobenzophenone, 4-aminobenzophenone, 2-aminophenyl phenyl sulfite,
3-aminophenyl phenyl sulfide, 4-aminophenyl phenyl sulfite, 2-aminophenyl phenyl sulfone, 3-aminophenyl phenyl sulfone, 4
-aminophenyl phenyl sulfone, α-naphthylamine, β-naphthylamine, l-amino-2-naphthol, 2-amino-1-naphthol, 4-amino-1-naphthol, 5-amino-1-naphthol, 5-amino- 2
-naphthol, 7-amino-2-naphthol, 8-amino-1-naphthol, 8-amino-2-naphthol, 1
-aminoanthracene, 2-aminoanthracene, 9-
Examples include aminoanthracene.

The molar ratio of tetracarboxylic dianhydride, aromatic diamine and aromatic monoamine used in the method of the present invention is 0.9 to 1.0 mole of aromatic diamine per mole of tetracarboxylic dianhydride. , aromatic monoamine in a proportion of 0.001 to 1.0 mol.

In the production of polyimide, in order to adjust the molecular weight of the polyimide produced, it is usual to adjust the ratio of tetracarboxylic dianhydride to aromatic diamine to 7A.
In the method of the present invention, the molar ratio of aromatic diamine to tetracarboxylic dianhydride is from 0.9 to 1.0 in order to obtain a polyimide with good melt flowability.

The aromatic monoamine coexisting is used in an amount of 0.001 to 1.0 mol based on the tetracarboxylic dianhydride. If the amount is less than 0.001 mol, the thermal stability at high temperatures, which is the objective of the present invention, cannot be achieved. Moreover, if it exceeds 1.0 mol, the mechanical properties will deteriorate. The preferred usage amount is 0
．． The proportion is from Ol to 0.5 mole.

In the method of the present invention, all known polyimide production methods can be used, or it is particularly preferable to carry out the reaction in an organic solvent.

Examples of organic solvents used in this method include N,N-dimethylformamide, ! 1. N-dimethylacetamide, N,N-diethylacetamide, N,11 dimethylmethoxyacetamide, N-methyl-2-pyrrolidone, 1.3-dimethyl-2-imidazoricinosyl, N-methylcub U'+lactam, 1.2- Cymer l-i-thietane, his(2-methoxyethyl)needle, 1,2-bis(2-meth A-thyl-oxy)ethane, bis(2-(2-methoxyethyl)
-Me-1-xyel-l-xy)ethyl) ether, de) Rahi-herofuran, lj-dioA-san, 1,4-thioxane, pyridine, picoline, dimethylsulfoxide, dimethylsulfonte! Examples include -ramethyl urea, hexamethyl small sphoramitophenol, m-cresol 6 p-cresol, p-chlorophenol, anisole, and the like. Also, what about these organic solvents? (It may be used alone or in combination of two inserts.

Method 1 of the present invention involves adding tetracarboxylic dianhydride, aromatic diamine, and aromatic monoamine to an organic solvent and reacting them. Method (b) 1. After adding an aromatic monoamine to the carboxylic dianhydride and causing the reaction, add an aromatic diamine and continue the reaction. (c) De-l-carponic acid monoanhydride, )''J aromatic group;
Any method of addition may be used, such as addition of y-S group monoamine to step II+f and reaction.

The reaction is carried out at temperatures ranging from 0°C to 250°C.

It is usually carried out at a temperature of ζ460°C or higher.

The reaction pressure is not particularly limited, and the reaction can be carried out sufficiently at this pressure.

The reaction temperature varies depending on the type of detracarboxylic acid anhydride, aromatic diamine, aromatic monoamine used, solvent, and reaction temperature.

Through such a reaction, during the repetition of the following formula (V), Lh
2+, acid is generated to polyamide 1, which is the same as 2+.

(In the formula, R is the same as above.) This polyamic acid is dehydrated by heating at 100 to 400°C, or it is converted into chemical waste by using a commonly used imidizing agent such as triethylamine and acetic anhydride. Accordingly, a corresponding polyimide having a repeating unit of the following formula (rV) as a basic skeleton can be obtained.

(In the formula, R is changed to the above.) After forming the polyamic acid at a low temperature in the shell, it is further thermally or chemically imidized. It is also possible to obtain a polyimide by carrying out the production of polyamic acid and the reaction of hot waste 1-conversion at a temperature of 11v at a temperature of After suspending or dissolving it in the solution, a reaction is carried out under heating to produce a bo[noamic acid] and to convert it into a dehydrated garbage, thereby converting the repeating unit of the above formula (IT) into a basic Go case. You can also do (1) the Boliimi 1- on the right.

In addition, the king of tetracarboxylic dianhydride, aromatic diamine, and aromatic monoamine is mixed without using an organic solvent,
A method of obtaining polyimide by treatment in the presence or absence of a dehydrating agent is also used.

When the polyimide having the finished product 1J1 is subjected to melt molding, other thermoplastic resins such as polyethylene, polypropylene, polycarbonate,
Polyarylate, polyamide polysulfone, polyether sulfone, polyether ketone, polyphenylene sulfide, polyamideimide, polyetherimide, modified polyphenylene oxide, etc. can also be blended in appropriate amounts depending on the purpose. Furthermore, the following fillers used in ordinary resin compositions may be used to the extent that the object of the invention is not impaired, namely, graphite,
Wear resistance improvers such as carborundum, silica powder, molybdenum disulfide, fluororesin, glass fiber, carbon fiber, boron fiber, silicon carbide zmm, carbon whisker,
Reinforcing materials such as asbestos, metal fibers, ceramic fibers,
Flame retardant improvers such as antimony trioxide, magnesium carbonate, and calcium carbonate, electrical property improvers such as clay and mica, anti-tracking agents such as asbestos, silica, and graphite, etim barium, silica, calcium metasilicate, etc. #acidity agent, iron powder, zinc powder,
Thermal conductivity improvers such as aluminum powder and copper powder, other glass beads, glass bulbs, talc, diatomaceous earth, alumina,
These include whitebait balloons, water-use alumina, metal oxides, and colorants.

[Examples] Hereinafter, the present invention will be specifically explained using Examples and Comparative Examples.

Example 1 A reactor equipped with a stirrer, a reflux condenser and a nitrogen inlet tube was charged with 218 g (1.0 mol) of pyromellitic anhydride and 4550 g of N,N-dimethylacetamide.
Bis(4-[4-(4-aminophenoxy)phenoxy]phenyl)sulfone 585.8 g (0.95 mol)
was added in portions at room temperature under a nitrogen atmosphere while being careful not to increase the solution temperature, and the mixture was stirred at room temperature for about 20 hours. The logarithmic viscosity of the polyamic acid obtained at this time was 0.56 dl/g. Note that the logarithmic viscosity is calculated using N,N-dimethylacetamide as a solvent, concentration 0.5 g/100 ml solvent, 35°
C'''C is the measured value (the same applies hereinafter).

To this polyamic acid solution, 9.3 g (0.10 mol) of aniline was added under a nitrogen atmosphere at room temperature, and the mixture was further stirred for 1 hour.Next, to this solution was added 202 g (2 mol) of triethylamine and 306 g (3 mol) of aniline. About 2 hours after the completion of the dropwise addition of acetic anhydride, yellow polyimide powder began to precipitate. The mixture was further stirred at room temperature for 20 hours, and one reaction product was discharged into methanol and filtered. Furthermore, it was dispersed in methanol, washed, filtered, and dried at 180°C for 2 hours. 736g
polyimide powder was obtained. This polyimide powder had a glass transition temperature of 285°C and a melting point of 420°C (according to OSC, hereinafter the same).

The polyimide powder obtained in this example was tested using a Koka type flow tester (manufactured by Shimadzu Corporation, CFT-5001).

Repeated measurements of melt viscosity were performed using an orifice with a diameter of 0.1 c+m and a length of lc+s. After being kept at a temperature of 440°C for 5 minutes, it was extruded at a pressure of 100 kg/cm''. The resulting strand was crushed and extruded under the same conditions five times in a row.

The relationship between the number of repetitions and the melt viscosity is shown in FIG. 1. Even when the number of repetitions increases, there is almost no change in the melt viscosity, indicating that the thermal stability is good.

Comparative Example 1 729 g of polyimide powder was obtained in exactly the same manner as in Example 1, except that the reaction with aniline was not performed.

Using this polyimide powder, repeated melt viscosity tests were conducted using a flow tester in the same manner as in Example 1, and the results shown in FIG. 1 were obtained.

As the number of repetitions increases, the melt viscosity increases, and Example!
The thermal stability was inferior to that of the polyimide obtained in .

Example 2 294 g (1.0 mol) of 3.1',4,4°-biphenyltetracarboxylic acid-
Anhydride, 94 g (0.15 mol) of aniline and 4986 g of dimethylacetamide) were charged and bis(4
Add 585.8 g (0.95 mol) of [4-(4-aminophenoxy)phenoxy]phenyl)sulfone under a nitrogen atmosphere at room temperature, taking care to increase the solution temperature by 1-
Stir for about 20 minutes at room temperature. The logarithmic viscosity of the obtained polyamic acid was 0.51.

Next, 202 g (2-11 nyl) triethylamine and 306 g (3 mol) acetic anhydride were added dropwise to this solution. Stir for 20 hours to make a pale yellow slurry11)
is. This slurry was filtered and washed with methanol, #180.
After drying under pressure for 8 hours at °C, 810 g of 1 color polyimide powder was obtained. The glass transition temperature of this polyimide powder is 2
It was 61″C.

The molding stability of the polyimide obtained in this example was measured by changing the residence time in the cylinder of a flow tester. The temperature was 380° C. and the pressure was 100 kg/cm”.

Figure 2 shows the results. i in the cylinder? ! Even when the residence time becomes longer, the melt viscosity hardly changes, indicating good stability and stability. Comparative Example 2 Actual h% Exactly the same as Example 2, except that aniline was used! I got a pale Buddha-colored polyimide cover.

Glass transition of polyimide, opening degree is 261'(,;
As in Example 2, the residence time in the Flow Destar cylinder was changed and the melting was measured to be 11 degrees.
The melt viscosity increased as the residence time increased, and the C thermal stability was inferior to that of the polyimide obtained in Example 2.

Example 3 In an apparatus similar to Example 1, bis(1-[4-(4-aminophenoxy)phenoxy]phenyl) sulpone 585
．． 8 g (095 mol), 310 g (1,0 mol) of bis(3,4-dicarboxyphenyl)edernianhydride, aniline! Charge m-cresol of i5 and 35701τ and heat with stirring under a nitrogen atmosphere to 50°C.
After stirring for 3 hours, the mixture was filtered to obtain a polyimide layer. This polyimide powder was purified by washing with methanol and acetone. The glass transition temperature of this polyimide material was 235°C.

Same as Example 1, temperature: 360°C, pressure 100k It
/ crx' was repeatedly extruded in a flow test and the melt viscosity of each was measured, and it was found that iI! Almost no change in melt viscosity was observed depending on the n constant number of times. The results are shown in Figure 3.

[Effects of the Invention 1] According to the method of the present invention, it has excellent mechanical properties, thermal properties, electrical properties, and solvent resistance, and is thermally stable for a long time with tFt thermal properties, and is moldable. ■: A polyimide with excellent properties can be provided.

[Brief explanation of the drawing]

1 and 3 are diagrams showing the relationship between the number of melting cycles and the melt viscosity of the polyimide of the present invention, and FIG. 2 is a diagram showing the relationship between the residence time of the polyimide of the present invention in a flow tester cylinder and the melt viscosity. ] Mother-in-law 1 man

Claims (1)

[Claims] 1. A method for producing polyimide, which comprises reacting an aromatic diamine with a tetracarboxylic dianhydride and thermally or chemically imidizing the obtained polyamic acid, comprising: (a) aromatic dianhydride; The group diamine is an aromatic diamine represented by the following formula (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I), and (b) Tetracarboxylic dianhydride is represented by the following formula (II) ▲ Numerical formula, chemical formula, There are tables etc.▼(II) (In the formula, R is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group,
Represents a tetravalent group selected from the group consisting of a monocyclic aromatic group, a fused polycyclic aromatic group, and a non-fused polycyclic aromatic group in which aromatic groups are interconnected directly or through a bridge member. . ) is a tetracarboxylic dianhydride represented by (c)
Furthermore, the reaction is expressed by the following formula (III) Z-NH_2(III) (wherein, Z is a monocyclic aromatic group, a fused polycyclic aromatic group, or a non-containing group in which the aromatic groups are interconnected directly or through a bridge member). (d) The amount of aromatic diamine is a monovalent group selected from the group consisting of fused polycyclic aromatic groups. The ratio of aromatic monoamine is 0.9 to 1.0 mol per mol of anhydride, and the amount of aromatic monoamine is 1 mol of tetracarboxylic dianhydride.
Formula (IV) characterized by a ratio of 0.001 to 1.0 mole per mole ▲There are mathematical formulas, chemical formulas, tables, etc.▼(IV) (In the formula, R is as defined in formula (II) ) A method for producing a polyimide with good thermal stability, which has a repeating unit represented by the following as a basic skeleton.