JPS60108464A - Aromatic polyimide solution composition - Google Patents

Abstract

PURPOSE:To provide the titled composition having high concentration, low viscosity, and excellent heat resistance and mechanical properties, by dissolving an oligomer obtained by the polymerization and imidation of a specific aromatic tetracarboxylic acid dianhydride and an aromatic diamine, and a specific ester in a phenolic solvent. CONSTITUTION:(A) An oligomer obtained by the polymerization and imidation of (i) an aromatic diamine and (ii) 65-98mol%, based on the amine component, of an aromatic tetracarboxylic acid dianhydride containing >=40mol% 2,3,3',4'- biphenyltetracarboxylic acid dianhydride and (B) an aromatic tetracarboxylic acid monohydric alcohol diester are dissolved in (C) a phenolic solvent. The amount of the component B is selected to essentially equalize the molar amount of the acid component in the oligomer to that of the diamine component. The anhydride in the component A preferably contains 60-20% 3,3',4,4'-biphenyltetracarboxylic acid dianhydride as another anhydride.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aromatic polyimide solution composition. More particularly, the present invention relates to aromatic polyimide solution compositions with high concentrations and low solution viscosity that are particularly useful as polyimide varnishes.

As a method for producing an aromatic polyimide solution composition, a tetracarboxylic acid component and a diamine component are polymerized in a specific solvent to produce an aromatic polyamic acid solution, which is a precursor of aromatic polyimide, and then the polyamic acid is heated or imidized with a dehydrating agent to form an aromatic polyimide solution (two-step method), and a tetracarboxylic acid component and a diamine component are reacted at high temperature in a specific solvent to form an aromatic polyimide solution through polymerization and competitive imidization. A method of preparing a polyimide varnish solution (one-step method) has been well known.

Among these, in the former method (two-step method), the solubility of the intermediate polyamic acid is poor, and N-methylpyrrolidone, N-methylpyrrolidone,
It has drawbacks such as the need to use expensive and highly hygroscopic solvents such as dimethylacetamide and dimethylformamide, and the need to store it under cooling because viscosity increases and gelation occurs when stored at room temperature. When imidizing S, etc., desorbed substances such as water are generated, so when this aromatic polyamic acid solution is used as a wax for purposes such as coating electric wires, it may cause so-called "blister". It has drawbacks such as being prone to defects.

On the other hand, in the latter method (one-step method), a soluble aromatic polyimide can only be obtained when a specific aromatic tetracarboxylic acid component and an aromatic diamine are used, so the selection of these raw materials and solvent is important. becomes.

Regarding this one-stage method, for example, Japanese Patent Application Laid-Open No. 50-1135
No. 97 discloses a soluble aromatic product obtained by subjecting an aromatic tetracarboxylic acid component mainly composed of biphenyltetracarboxylic acids and an aromatic diamine component to a polymerization Φ imidation reaction at high temperature in an approximately equimolar organic polar solvent. A method for manufacturing polyimides of the group polyimides is described. This method addresses the previously known problems with soluble polyimides produced using benzophenone tetracarboxylic acids as acid components, namely, when the polymerization reaction temperature exceeds 160°C, the resin becomes cloudy or gels, and the solution Stability decreases (Special Public Interest Act 1977)
-9576 Publication) or special diamines having asymmetrical or side chains must be used as the diamine component, resulting in poor heat resistance and mechanical properties (for example, Japanese Patent Publication No. 46-17145, Japanese Patent Publication No. 47 -26878
No., Special Publication No. 49-18639, Special Publication No. 49-1911
No. 9, Special Publication No. 49-30717, Special Publication No. 49-307
18 and Japanese Patent Publication No. 49-106599).

However, in the method disclosed in JP-A-50-113597, the reaction proceeds rapidly because the polymerization reaction is carried out at high temperatures, and the aromatic polyimide produced has an extremely high degree of polymerization. There was a problem with that. Therefore, with this method, it is difficult to produce an aromatic polyimide solution having a desired solution viscosity with good reproducibility.

Particularly when using an aromatic polyimide solution as a varnish, a high polymer concentration is desired from the viewpoint of productivity and cost. A solution with a low viscosity of about 30'0 is desired. In order to obtain such a high concentration and low viscosity solution, it is necessary to appropriately suppress the degree of polymerization of polyimide produced in the polymerization/imidization reaction.

Regarding the polymerization/imidization reaction that makes it possible to suppress the degree of polymerization of polyimide, JP-A-56-38324 and JP-A-57-34127 disclose aromatic tetracarboxylic acid containing biphenyltetracarboxylic acid. Approximately equal moles of acid component and aromatic diamine are used, the polymerization reaction system is a closed system, and if necessary, water is added to the reaction system to adjust the water pressure of the reaction system and/or the water content of the polymerization solution. Or at 100-300'C until the moisture content of the polymerization solution reaches a constant value!
Disclosed is a method for controlling solution viscosity by polymerizing at a polymerization temperature of .

However, these methods require the reaction system to be a closed system, and the effect of inhibiting the polymerization reaction of water is relatively small. In order to obtain this, there is the inconvenience that the water pressure of the reaction system and the water content of the polymerization solution must be kept extremely high.

Furthermore, Japanese Patent Publication No. 55-11696 describes a method of reacting an aromatic tetracarboxylic acid component containing benzophenone tetracarboxylic acid with an aromatic diamine component in an organic solvent containing a polyhydric alcohol; -4.
No. 587 discloses a similar method using an aromatic diamine having a side chain as an aromatic diamine component.

However, the aromatic polyimide solutions produced by these methods also have the same problems as the above-mentioned ones, such as insufficient stability of the solution and insufficient heat resistance and mechanical properties of the resulting varnish.

In Japanese Patent Publication No. 56-5466, pyromellitic anhydride, 3.3', 4
．． A polymerized/imidized oligomer obtained by reacting an aromatic tree or aromatic tetracarboxylic acid anhydride such as 4'-henzophenone tetracarboxylic anhydride or a derivative thereof with a molar excess of aromatic diamine, 1, 2, 3
．． A solution for forming a heat-resistant polymer (aromatic polyimide solution) is disclosed, which contains a polyhydric alcohol ester of 4-butanetetracarboxylic acid or an aromatic tricarboxylic acid or aromatic tetracarboxylic anhydride. In this aromatic polyimide solution, the presence of polyhydric alcohol during polymerization and formation of imidized oligomers causes ester bonds to be included in the polyimide main chain, which improves solubility. Problems such as a decrease in heat resistance and mechanical strength arise due to the introduction of .

As a result of research aimed at solving the above-mentioned drawbacks of the aromatic polyimide solution compositions known so far, the inventor has discovered that carboxylic acids containing specific aromatic tetracarboxylic dianhydrides have been developed. Polymerization φ obtained from the component and the aromatic diamine component in excess with respect to the carboxylic acid component
Utilizing the high solubility of the imidization reaction product oligomer in phenolic solvents, an amount of aromatic compound corresponding to the excess aromatic diamine class forming the amine end of the polymerized and imidization product oligomer is added. By blending the tetracarboxylic acid component as an ester of monohydric alcohol,
The inventors have discovered that it is possible to obtain a polyimide solution composition that stably maintains a low viscosity despite its high concentration and has excellent properties such as heat resistance and mechanical strength, and has arrived at the present invention.

That is, the present invention provides (A) aromatic diamine and 65% for the diamine component.
~98 mol% of 2,3.3".

Polymerization with aromatic tetracarboxylic dianhydride containing 40 mol% or more of 4'-biphenyltetracarboxylic dianhydride.
An imidide oligomer, and (B) m alcohol diesters of aromatic tetracarboxylic acid in an amount such that the acid component and diamine component in the polymerized Φ imidide oligomer are substantially equimolar, are phenolic solvents. An aromatic polyimide solution composition is provided.

According to the present invention, the polymerization and imidization reaction can be easily controlled without impairing the excellent properties of aromatic polyimide, and the drawback that the aromatic polyimide solution composition becomes highly viscous can be overcome, and it can be used for a long period of time. It becomes possible to obtain an aromatic polyimide solution composition with improved storage stability.

Further, according to the present invention, for example, by using an inexpensive phenolic solvent such as cresol, which is a general-purpose solvent for electric wire varnish, the polymer concentration is as high as 15 to 40% by weight, and at a temperature of several hundred poise/30°C. An aromatic polyimide solution composition having the following low solution viscosity can be obtained extremely easily and with good reproducibility. The aromatic polyimide solution composition of the present invention is also characterized by excellent long-term storage stability as described above. Furthermore, when the aromatic polyimide solution composition of the present invention is used for applications such as electric wire coating, coating, and film formation, coatings with excellent heat resistance, electrical insulation properties, mechanical properties, abrasion resistance, and solvent resistance can be obtained. layer,
A coating or film is obtained. Therefore, the aromatic polyimide solution composition of the present invention is extremely useful, especially as a varnish.

Next, the present invention will be explained in detail.

As described above, the present invention provides an aromatic polyimide solution composition in which a specific polymerized/imidized oligomer (A) and a monohydric alcohol diester (B) of an aromatic tetracarboxylic acid are dissolved in a phenolic solvent. It is. Polymerization of the above
The imidide oligomer (A) is an aromatic diamine,
2, 3, 3”.

It is an oligomer polymerized and imidized with an aromatic tetracarboxylic dianhydride containing 140 mol% or more of 4'-biphenyltetracarboxylic dianhydride. However, in producing the above polymerized/imidized oligomer, the aromatic tetracarboxylic dianhydride is used in an amount of 65 to 98 mol % based on the diamine component.

This polymerized/imidized oligomer (A) can be produced by heating an aromatic diamine and an aromatic tetracarboxylic dianhydride to a high temperature in a phenolic solvent to polymerize and imidize them according to a known method. I can do it. however,
In the present invention, the aromatic tetracarboxylic dianhydride used in the reaction is 65 to 65% relative to the aromatic diamine component.
The amount must be insufficient within a certain range of 98 mol%. Furthermore, at least 40 mol % of the aromatic tetracarboxylic dianhydride must be 2,3.3°,4'-biphenyltetracarboxylic dianhydride. In the present invention, by using the aromatic tetracarboxylic dianhydride in such a composition and amount, the aromatic polyimide solution which is soluble in a phenolic solvent and is later formed as a compound 2 has excellent properties. Polymerized/imidized oligomers with q can be obtained.

The polymerization/imidization reaction described above can be carried out using known methods such as polymerization/imidization of each component in a phenolic solvent at a temperature in the range of 100 to 300'O, particularly in the range of 130 to 250'0. It can be carried out using a method similar to the above method.

1- In the aromatic tetracarboxylic dianhydride component, 2,
3.3',4°-Biphenyltetracarboxylic dianhydride is preferably used in combination with other aromatic tetracarboxylic dianhydrides. Examples of aromatic tetracarboxylic dianhydrides preferably used in combination include 3.3', 4.4°-
biphenyltetracarboxylic dianhydride and 3,3”,
4.4'-Benzphenonetetracarboxylic dianhydride can be mentioned. However, in small amounts, pyromellitic dianhydride, bis(3,4-dicarboxyphenyl)
Methani dianhydride, 2,2-bis(3゜4-dicarboxyphenyl)propani dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride Other carboxylic acid components such as can also be used in combination. Furthermore, a mixture of three or more types of acid anhydrides may be used as the carboxylic acid component.

The aromatic tetracarboxylic dianhydride used in the preparation of the polymerized/imidized oligomer (A) of the present invention is substantially 2
．． 3. It is preferable to consist of 40 to 80 mol% of 3',4'-biphenyltetracarboxylic dianhydride and 20 mol% of other aromatic tetracarboxylic dianhydride 6O-. 50 of tetracarboxylic dianhydrides
The mole % or more is preferably 3,3", 4,4°-biphenyltetracarboxylic dianhydride or 3.3', 4,4'-benzophenonetetracarboxylic dianhydride. Particularly preferred is , substantially 2.3.3', 4
'-Biphenylte I lacarboxylic dianhydride 40-80
This is a blend consisting of mol % and 60 to 20 mol % of 3.3', 4.4'-biphenyltetracarboxylic dianhydride.

The aromatic diamine used in the present invention may be any aromatic diamine as long as the resulting aromatic polyimide is soluble. Examples of preferred aromatic diamines include 4,4°-diaminodiphenyl ether, 4,4′-
Mention may be made of diaminodiphenylmethane, 4,4'-diaminodiphenylthioether, 4,4'-diaminodiphenylsulfone, 0-tolidine, and 0-dianisidine. These aromatic diamines may be used alone or in combination of two or more. Also,
The above aromatic diamine may be used in combination with, for example, p-phenylenediamine, m-phenylenediamine, 3,5-diaminobenzoic acid, diaminonaphthalene (1,5-diaminonaphthalene, 2,6-diaminonaphthalene), etc. .

The blending ratio of aromatic tetracarboxylic dianhydride and aromatic diamine for preparing the polymerized/imidized oligomer (A) of the present invention is as follows: The amount should be 65 to 98 mol % based on 5 mol. When the amount of aromatic tetracarboxylic dianhydride exceeds 98 mol% based on the aromatic diamine, polymerization of the oligomer (A) tends to occur, making it difficult to reduce the viscosity, and when the amount is less than 65 mol%. This increases the amount of monomer components, making it difficult to obtain coatings, films, etc. with sufficient performance.

The amounts of aromatic tetracarboxylic dianhydride and aromatic diamine added to the solvent can be appropriately selected depending on the desired degree of polymerization, solution viscosity, and form of use, but basically the resulting aromatic polyimide solution composition It is desirable to adjust the aromatic polyimide concentration therein to about 15 to 40% by weight. When the concentration of aromatic polyimide in the aromatic polyimide solution composition exceeds 40% by weight, the aromatic polyimide solution composition has too high a viscosity and is difficult to use, for example, as a varnish for coating electrical materials. It cannot be used for this purpose, and it is difficult to use it practically for other purposes as well. Further, when the aromatic polyimide concentration in the aromatic polyimide solution composition is 15% by weight without stirring, the solution viscosity becomes sufficiently low, but such a dilute solution has little practical utility value.

Examples of the phenolic solvent used in the preparation of the polymerized φ imidide oligomer (A) of the present invention include cresol,
Examples include xylenol, which can be used alone or in combination. Also, cresol,
Other phenolic solvents such as phenol and halogenated phenol may be partially mixed with xylenol.

The polymerized/imidized oligomer (A) of the present invention prepared by the method described in Section 2 above is an oligomer having amine groups at both ends of the molecule and substantially only imide bonds in the main chain of the molecule. It is.

The polymerized/imidized oligomer (A') in item L contains m alcohols of aromatic tetracarboxylic acid in an amount such that the acid component and the diamine component in the polymerized/imidized oligomer are substantially equimolar. The diester (B) is blended to form the polyimide solution composition of the present invention.

In place of m alcohol diesters of aromatic tetracarboxylic acids (B) in the polymerized/imidized oligomer (A),
When aromatic tetracarboxylic acid, aromatic tetracarboxylic dianhydride, aromatic tetracarboxylic acid tetraester, etc. are blended, the solubility may be poor or the viscosity of the polyimide solution composition may become high or low. Even if it is possible to obtain a solution with high viscosity, it is not possible to obtain an aromatic polyimide solution composition that provides sufficient physical properties (particularly properties with respect to elongation tend to be poor).

The m-alcohol diester (B) of an aromatic tetracarboxylic acid used in the present invention can be obtained by reacting the aromatic tetracarboxylic acid, its salt or anhydride with m-alcohol.

The m-alcohol diester (B) of aromatic tetracarboxylic acid to be blended may be isolated or in solution, and even if it contains unreacted alcohol, there will be no problem. It can be used without.

The aromatic tetracarboxylic acid component constituting the aromatic tetracarboxylic acid monohydric alcohol diester (B) blended in the present invention is important for long-term storage stability and solubility of the aromatic polyimide in the resulting aromatic polyimide solution composition.
There is no particular limitation as long as heat resistance, mechanical strength, etc. Carboxylic acid, 3.3', 4.4'-benzophenonetetracarboxylic acid, pyromellitic acid, bis(3
,4-dicarboxyphenyl)methane, 2,2-bis(
3,4-dicarboxyphenyl)propane, bis(3,
4-dicarboxypher) ether, bis(3,4-
Mention may be made of aromatic tetracarboxylic acids such as dicarboxyphenyl) sulfone.

The m alcohols that can be used in the present invention include:
m containing lower aliphatic alcohol, aromatic alcohol, alicyclic alcohol, and ether group
Examples include alcohol. Among these,
Examples of lower aliphatic alcohols include methanol, ethanol, propatool, and butasol.
Examples of aliphatic alcohols, aromatic-hydric alcohols include benzyl alcohol and α-(or β-
) Examples of alicyclic-hydric alcohols such as phenethyl alcohol include pentanol and cyclohexanol, and examples of m alcohols having ether groups include methyl cellosolve and ethyl cellosolve.

Monohydric alcohol diester of aromatic tetracarboxylic acid (
The blending of B) into the polymerized/imidide oligomer (A) is as follows:
It is preferable to carry out at a temperature of 140°C or lower, especially at a temperature of 80°C or lower.
Preferably, it is carried out at a temperature below °C. Mixing temperature 14
If the temperature is maintained at 0°C or higher for a long period of time, a polymerization reaction will start during this period and the viscosity of the solution will increase.The aromatic polyimide solution will become too viscous, and will be difficult to use, for example, as a varnish for coating electrical materials. It becomes difficult to use it for its purpose,
It is also disadvantageous in other uses.

Next, Examples and Comparative Examples of the present invention will be shown.

9 The solution viscosity on each side below was measured as rotational viscosity using an E-type viscometer manufactured by Tokyo Keiki. The tensile strength of the produced film was measured using Autograph DSS-5000 manufactured by Shimadzu Corporation at a sample width of 10 mm, a distance between chucks of 50 mm, and a tensile speed of 50 mm/min.

[Example 1] 2,3.3' in a 1 fL separable flask.

4'-biphenyltetracarboxylic dianhydride 16.78
g (0,057 mol), 3.3', 4゜4゛-biphenyltetracarboxylic dianhydride 16.78 g (0,05
7 mol), 4,4'-diaminodiphenyl ether 24
．． 02g (0,120 mol) and m-cresol 2
30.30 g was added thereto, and the mixture was heated and stirred in an oil bath at 170°C for 3 hours to obtain a polymerized φ imidide oligomer solution (I) having a solution viscosity of 101 voids/30°C.

The acid component of the polymerized/imidized oligomer of this solution (I) is 95 mol % based on the diamine component.

0 Separately, in a 100m flask, 3.3".

4.4”-biphenyltetracarboxylic dianhydride 2.9
4g (0,010 mol), ethyl alcohol 2.77
g (0,060 mol), and m-cresol 13.
63 g was added thereto and heated and stirred for 1.5 hours in an oil bath at 140°C to obtain a 3,3°, 4°4°-biphenyltetracarboxylic acid ethyl alcohol diester solution (n).

Solution (I) 95;, 98 g (diamine component 0.040
mol, containing 0.038 mol of acid component), solution (II)
3. ．． 86 g (containing 0.002 mol of acid component Q) was added at room temperature and stirred for 5 hours to obtain an aromatic polyimide solution composition (I).

This aromatic polyimide solution composition (III) was a homogeneous solution, and the solution viscosity was 90 voids/300C. This solution (I[) was stored at 30° C. for 3 months, but maintained a uniform solution state.

The aromatic polyimide solution composition (I) was applied onto a glass plate and heated at 80° C. for 30 minutes, then heated to 300° C. for 1 hour to obtain a film with a thickness of about 20 #L. When the tensile strength of this film was measured, the strength at break was 14,3
kg/mm', and the elongation was 60%.

[Example 2] 2.94 g of 3.3',4.4'-biphenyltetracarboxylic dianhydride (0,0
10 moles), benzyl alcohol 2゜19g (0,0
20 mol) and 20.63 g of m-cresol,
Heat and stir in a 140°C oil bath for 1 hour and a half, 3.3
,4.4'-Biphenyltetracarboxylic acid benzyl alcohol diester solution (IIa) was obtained.

This solution (Ila) 4.61g (acid component 0.0018
85.82 g of the polymerized/imidized oligomer solution (I) obtained in Example 1 (containing 0.0 mole of diamine component)
(containing 358 mol and 0.0340 mol of acid component) at room temperature and stirred for 5 hours. The obtained aromatic polyimide solution composition (lira) was uniform and had a solution viscosity of 158 poise/3.
It was 0°C.

[Example 3] In a 300mM separable flask, add 2,3°3',
4'-Biphenylte i-lacarboxylic dianhydride 9.42
g (0,032 mol), 3.3'.

4.4′-Biphenyltetracarboxylic dianhydride 9.4
2 g (0,032 mol), 16.02 g (0,080 mol) of 4.4°-diaminodiphenyl ether, and 81.76 g of m-cresol were added, and the mixture was stirred for 2 and a half hours in an oil bath at 170'C. and solution viscosity 42
Poise/Polymerization/imidide oligomer solution at 30°C (
Ib) was obtained.

The acid component of the polymerized/imidized oligomer of this solution (Ib) was 80 mol % based on the diamine component.

Separately, in a 100mM flask, add 3.3', 4゜4゛-
Biphenyltetracarboxylic dianhydride 2°94g (0,
010 mol), ethyl alcohol 1.87 g (0,0 mol), ethyl alcohol 1.87 g (0,0
41 mol), and m-cresol 8.・Add 12g and heat and stir in a 140°C oil bath for 1.5 hours.
, 3°, 4.4'-3 A biphenyltetracarboxylic acid ethyl alcohol diester solution (I[b) was obtained.

Solution ('I b) 57.88g (diamine component 0°0
40 mol, acid component 0.032 mol) in a solution (II
b) 10.28 g (containing 0 acid components and 8 moles of 'OO) was added at room temperature and stirred for 4 hours to obtain an aromatic polyimide solution composition (II[b). This solution (I[rb' is
The aromatic polyimide solution composition (I[b) was applied onto a glass plate and heated to 80°C for 30 minutes, and then the temperature was raised to 300°C. The mixture was heated for 1 hour to obtain a film with a thickness of about 2,071 cm. When the tensile strength of this film was measured, the strength at break was 16
, 3 kg/mm', and the elongation was 73%.

[Example 41 Into a 300mM separable flask, add 2,3°3',
4'-biphenyltetracarboxylic dianhydride 7.95g
(0,027 mol), penzophenonte I lacarboxylic dianhydride 8.70 g (0,04 27 mol), 4,4'-diaminodiphenyl ether 1
2. olg (0,060 mol) and 114.84 g of m-cresol were added and heated and stirred in an oil bath at 170°C for 2 hours until the solution viscosity was 59 poise/30°.
A polymerized and imidized oligomer solution (Ic) of C was obtained.

The acid component of the polymerized ψ imidide oligomer in this solution (Ic) was 90 mol % based on the diamine component.

Separately, in a loOmJlj flask, add 3.22 g (0,010 mol) of benzophenone tetracarboxylic dianhydride.
, methyl cellosolve 3.05g (0°040mol), m
17.47 g of -cresol was added, and the mixture was heated and stirred in a 140°C oil bath for 2 hours to obtain a solution of benzophenone tetracarboxylic acid methyl cellosolve diester (II C).

Solution (IIc) 9 was added to 90.78 g of solution (Ic) (containing 0.038 mol of diamine component and 0.034 mol of acid component).
．． 01 g (containing 0.004 mol of acid component) was added at room temperature and stirred for 16 hours. The obtained aromatic polyimide solution composition (■C) was uniform and had a solution viscosity of 101 voids/30
It was ℃.

[Example 5] In a 300 ml separable flask, add 2.3°3'
, 4'-biphenyltetracarboxylic dianhydride 8.18
g (0,021 mol), 3.3'.

4.4'-Biphenyltetracarboxylic dianhydride 6.1
8 g (0,021 mol), 12.03 g (0,060 mol) of 4,4'-diaminodiphenyl ether, and 45.09 g of m-cresol were added, and the mixture was heated at 180°.
The polymerized/imidide oligomer solution (I
d) was obtained.

The acid component of the polymerized/imidized oligomer of this solution (Id) was 70 mol % based on the diamine component.

Separately, in a 100mM flask, add 3.3', 4゜4゛-
Biphenyltetracarboxylic dianhydride 8°82g (0,
030 mol), ethyl alcohol 5.55 g (0,1
20 mol) and 24.42 g of m-Frazi) Iy were added, heated and stirred in a 100°C oil bath for 2 hours, and
．． A 3',4,4'-biphenyltetracarboxylic acid ethyl alcohol diester solution (IId) was obtained.

Solution (IId) was added to 62.40 g of solution (Id) (containing 0°054 mol of diamine component and 0°038 mol of acid component).
2'0, 37 g (containing 0 acid components and 6 moles of 'Ol) was added at room temperature and stirred for 5 hours. The obtained aromatic polyimide solution composition (I d) was uniform and had a solution viscosity of 47.
It was Poise/30'0.

[Example 6] In a 300 ml separable flask, add 10.5 ml of 2,3゜3゛,4''-biphenyltetracarboxylic dianhydride.
9g (0,036 mol), 3.3°.

4.4'-biphenyltetracarboxylic dianhydride 3.5
4g (0,012 mol), 4,4'-diaminosif x
11.91 g (0,060 mol) of nyl ether and 61.05 g of m-cresol were added, and the mixture was heated at 170°
The mixture was heated and stirred in an oil bath of C for 1.5 hours to obtain a polymerized imidide oligomer solution (Ie) at 25 voids/30°C.

The acid component of the polymerized/imidized oligomer of this solution (Ie) was 80 mol % based on the diamine component.

Separately, in a loOmM flask, 6.54 g (0,030 mol) of pyromellitic dianhydride, 5 ml of ethyl alcohol
．． 52 g (0,120 mol) and m-cresol 18
．． 99 g of the solution was added and heated and stirred in a 140° C. oil bath for 1.5 hours to obtain a solution of pyromellitic acid ethyl alcohol diester (me).

Solution (Ie) 81.48g (diamine component 0°056
mol, containing 0.045 mol of acid component) in solution (IIe)
64 g (containing 0.011 mole of acid component) was added at room temperature and stirred for 5 hours. The obtained aromatic polyimide solution composition (Ice) was uniform and had a solution viscosity of 25 poise/30°C.

[Example 7] In a 300mM separable flask, 2,3°3”, 4
-Biphenyltetracarboxylic dianhydride 5.59 g (0,019 mol), 3.3'.

4.4°-Biphenyltetracarboxylic dianhydride 5.5
9g (0,019 mol), m-2, = diamine 3
．． 02g (0,028 mol), 2.40g (0,012 mol) of 4゜4''-diaminodiphenyl ether, and 66.58g of m-cresol were added.
Heat and stir in an oil bath at °C for 2 hours, and the solution viscosity is 51.
Boyds/Polymerization/imidide oligomer solution at 30°C (
If) was obtained.

The acid component of the polymerized/imidized oligomer in this solution (If) is 95 mol % based on the diamine component.

Separately, put 2.18 g (0,010 mol) of pyromellitic dianhydride, 1.97 g (0,042 mol) of ethyl alcohol, and 11.53 g of m-cresol into a room+Jl flask, and place in an oil bath at 140°C. de1
The mixture was heated and stirred for half an hour to obtain a solution of pyromellitic acid ethyl alcohol diester (IIf).

Solution (I f), 76.98g (diamine component 0°0
(If
) 2.98 g (containing 0.00.2 mol of acid component) was added at room temperature and stirred for 5 hours. The resulting aromatic polyimide solution composition (lI[f) was uniform and had a solution viscosity of 47 poise/30'C! Met.

[Example 8] In a 300 mJ1 separable flask, 2.3°3',
4'-biphenyltetracarboxylic dianhydride 5.59g
(0,019 mol), 3.3'.

4.4°-Biphenyltetracarboxylic dianhydride 5.5
9g (0,019 mol), Onlysine 8.49g (0
, 040 mol), m-cresol 55.07 g, and phenol 23.64 g were heated and stirred in an oil bath at 170°C for 2.5 hours until the solution viscosity was 63 voids/
A polymerized/imidide oligomer solution (Ig) at 30°C was obtained.

The acid component of the polymerized/imidized oligomer of this solution (Ig) was 90 mol % based on the diamine component.

This solution (I g) 53.47 g (diamine component 0.
022 mol, acid component 0.021 mol), 1.70 g of the solution (IIf) obtained in Example 7 (acid component 0.00
1 mol) was added at room temperature and stirred for 5 hours. The obtained aromatic polyimide solution composition (III g) was uniform and had a solution viscosity of 60 voids/30°C.

[Comparative Example 1] In a 300 mJ1 separable flask, 2□3°3',
4'-biphenyltetracarboxylic dianhydride 8.83g
(0,030 mol), 3.3'.

4.4°-Biphenyltetracarboxylic dianhydride 8.8
3 g (0,030 mol), 12.01 g (0,060 mol) of 4,4'-diaminodiphenyl ether and m
- 118.02 g of cresol was added, and the mixture was heated and stirred in an oil bath at 170° C. for 2 hours to effect polymerization competitive imidization.

The acid component of the polymerized/imidized product in this polymerized/imidized product solution is 100% by mole based on the diamine component.

1 As described below, an aromatic polyimide solution obtained by simply polymerizing and imidizing equimolar amounts of an acid component and a diamine component without using m alcohol diesters of an aromatic tetracarboxylic acid has a polyimide content of approximately It was a homogeneous polyimide solution containing 20% by weight, but at 10,000 poise/30°
It showed a very high solution viscosity.

[Comparative Example 2] Polymerized/imidized oligomer solution (I) obtained in Example 1
was applied on a glass plate and heated at 80°C for 30 minutes, followed by 3
The temperature was raised to 00'0 and heated for 1 hour to obtain a film with a thickness of about 20 to 25 g. The strength at break of this film is 12,
6 kg/mm', and the elongation was 10%.

[Comparative Example 3] Polymerized/imidide oligomer solution obtained in Example 3 (Ia
) was applied to a glass plate and heated at 80°C for 30 minutes, then raised to 300°C for 1 hour.

The resulting product was damaged by slight contact and could hardly be called a film.

2

Claims (1)

[Claims] l. (A) Aromatic diamine and 65 to 98 mol% of 2,3.3' based on the diamine component. Polymerization with aromatic tetracarboxylic dianhydride containing 40 mol% or more of 4'-biphenyltetracarboxylic dianhydride.
An imidide oligomer, and (B) a monohydric alcohol diester of an aromatic tetracarboxylic acid in an amount such that the acid component and diamine component in the polymerized Φ imidide oligomer are substantially equimolar, are phenolic solvents. An aromatic polyimide solution composition obtained by dissolving. 2゜The --hydric alcohol diester of aromatic tetracarboxylic acid is from the group consisting of --hydric alcohols having lower aliphatic-hydric alcohols, aromatic-hydric alcohols, alicyclic-hydric alcohols, and ether groups. The aromatic polyimide solution composition according to claim 1, which is a monohydric alcohol diester of one or more selected aromatic tetracarboxylic acids. The aromatic tetracarboxylic dianhydride forming the polymerized/imidized oligomer of (A) in 3.
3.3',4''-Biphenyltetracarboxylic dianhydride 40-80 mol% and other aromatic tetracarboxylic dianhydride 60-20 mol% Claim 1 Aromatic polyimide solution composition according to item 4.5 of the other aromatic tetracarboxylic dianhydrides mentioned above.
4. The aromatic polyimide solution composition according to claim 3, wherein 0 mol% or more is 3.3', 4.4°-biphenyltetracarboxylic dianhydride. Claim 4, characterized in that the other aromatic tetracarboxylic dianhydride mentioned above consists essentially of 3.3', 4.4°-biphenyltetracarboxylic dianhydride.
The aromatic polyimide solution composition described in 1. Claims characterized in that 50 mol% or more of the aromatic tetracarboxylic dianhydride described in 6.1- is 3.3', 4.4'-benzophenone tetracarboxylic dianhydride. 4. Aromatic polyimide solution composition according to item 3. The aromatic polyimide solution-side acid product according to claim 1, wherein the 7° aromatic diamine is 4,4''-diaminodiphenyl ether.