JPS6128526A - Production of organic solvent-soluble polyimide compound - Google Patents

Abstract

PURPOSE:To obtain a polyimide compound having a high glass transition point and a high heat decomposition temperature, by reacting at least two aromatic tetracarboxylic acid dianhydrides with a specified aromatic diamine and imidating the polyamic acid. CONSTITUTION:At least two aromatic tetracarboxylic acid dianhydrides are reacted with an aromatic diamine of formula I to prepare a polyamic acid, which is then imidated to obtain the purpose polyimde compound. In formula I, X is a bivalent group selected from among -O-, -S-, -CO-, -SO2-, -CONH-, formula II(wherein n is 1-4), formula III (wherein R and R' are each a lower alkyl, fluorine-substituted lower alkyl or a halogen atom). The aromatic tetracarboxylic acid dianhydride is one in which four carboxyl groups are directly bonded to an aromatic ring and includes, for example, pyromellitic and 3,3',4,4'-benzophenonetetracarboxylic dianhydrides.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing an organic solvent-soluble polyimide compound, and more specifically, an organic solvent-soluble polyimide compound having a high glass transition temperature and a high thermal decomposition temperature and particularly excellent heat resistance. This invention relates to a method for producing polyimide compounds.

[Prior Art] Polyimide compounds generally have excellent heat resistance, so they can be used in films, wire covering materials, adhesives, etc. used at high temperatures.
It is extremely useful as a raw material for paints, etc., and is also highly anticipated in the fields of advanced technology such as electronics and the aerospace industry.

Conventional polyimide compounds are produced by polymerizing an aromatic tetracarboxylic dianhydride such as pyromellitic anhydride and an aromatic amine in a polar solvent to obtain an aromatic polyamic acid. There is known a film-like aromatic polyimide compound which is insoluble in a solvent and has a three-dimensional structure obtained by applying it to a film, forming it into a film, and then dehydrating and ring-closing it by a method such as heating. However, in conventional aromatic polyamide compounds, the stability of aromatic polyamic acid, which is the precursor thereof, is poor, and if left at room temperature, the viscosity of the polyamic acid solution decreases, and if left for a longer period of time, part of the aromatic polyamic acid solution undergoes dehydration and ring closure. It has the disadvantage that it becomes polyimide, becomes insolubilized, and becomes cloudy. Therefore, conventional solutions of aromatic polyamic acids have to be stored at low temperatures and must be handled with care.

In addition, in the above method for producing polyimide compounds, when imidizing the polyamic acid applied to the base material, it is necessary to heat it for a long time at a high temperature of usually 400°C or higher, which is disadvantageous from the viewpoint of energy saving. Due to the accompanying dehydration reaction, defects such as voids and pinholes occur in the resulting film, and it is difficult to obtain a smooth and homogeneous polyimide compound film.

Here, if the polyimide compound itself is soluble in a certain organic solvent, a polyimide compound film can be obtained by simply casting the solution onto a smooth surface and removing the solvent. The development of compounds is desired and is being attempted.

Many of the soluble polyimide compounds that have been proposed so far are
For example, stereoregularity can be achieved by introducing asymmetric monomer units, structural units with flexible skeletons and high mobility, or monomer units with bulky substituents into polymer chains through homopolymerization or copolymerization. The aim was to lower the solubility of the resulting polyimide compound.

For example, when introducing an asymmetric monomer unit,
A soluble polyimide compound used as a diamine component such as phenylindane diamine, which is an asymmetric diamine, is known (Japanese Unexamined Patent Publication No. 1982-82300). This polyimide compound is also soluble in general-purpose solvents such as tetrahydrofuran and halogenated hydrocarbons. However, it had the disadvantage of a lower thermal decomposition temperature than conventional aromatic polyimide compounds obtained from pyromellitic dianhydride and aromatic diamines.

In addition, as a polyimide compound that is soluble due to the high flexibility and mobility of the polymer chain, a polyimide compound having the structure of the following formula is known (Japanese Patent Publication No. 47-304
Publication No. 37). This polyimide compound is soluble in organic solvents due to the high mobility of its structural units, especially around ether bonds, but its glass transition temperature is 217°C, and it has an aromatic aroma obtained from conventional pyromellitic dianhydride and aromatic diamines. The heat resistance is considerably lower than that of group polyimide compounds (250 to 400°C), and has the disadvantage of poor heat resistance.

Based on the same idea as above, examples of polyimide compounds made soluble in organic solvents by increasing the mobility of polymer chains include 1.2. A polyimide compound obtained by reacting 3.4-butanetetracarboxylic acid with an aromatic diamine (Japanese Patent Publication No. 48-2238,
47-14503); Using hexamethylene diamine, which is an aliphatic diamine, as the diamine component, 3,
Polyimide compounds obtained in combination with 3°, 4.4°, -benzophenone tetracarboxylic acid are known (
However, since these polyimide compounds contain aliphatic units in their polyimide structure, their thermal decomposition temperature is lower than that of conventional aromatic polyimide compounds, and in that respect they have poor heat resistance. It has the disadvantage of being inferior.

In addition, examples of increasing solubility by introducing bulky substituents into the structure of polyimide compounds include cardo polymers (V,
V, Korshak et al., Macromol.

Chew, 011.45 (1874)), but since the monomers that are the raw materials for producing these polyimide compounds require a complicated synthesis process that spans several steps, they cannot be produced on an industrial scale. It is not suitable for manufacturing from the economic point of view.

Furthermore, at least 60 mol% of 3°3',4,
4°, -benzophenonetetracarboxylic acid and at least 60 mol% of the following general formula [wherein X is -CH2-1-0-1 R is a lower alkyl group, a lower alkoxyl group, a halogen,
-COOHl-OH or -SO3H. An aromatic polyimide compound obtained by reacting a diamine containing one or more aromatic diamines represented by
145). In order to make this polyimide compound soluble in phenolic solvents, p,p'-diaminodiphenyl compounds, which have lower symmetry than p,p'-diaminodiphenyl compounds and which further have a substituent R at the 1-position, are used. Seal, ■°-substituted diphenyl compound (the above general formula (I")), m, m"
It is essential to use 80 mol% or more of diamine such as -diaminodiphenyl compound (general formula (■) above), but as a result, this polyimide compound has become soluble in phenolic solvents, whereas conventional p, Compared to polyimide compounds using p'-diaminodiphenyl compounds and the like, it has a disadvantage that both the thermal decomposition temperature and the glass transition temperature are lower, and the heat resistance is inferior.

Further, as another soluble aromatic polyimide compound, a tetracarboxylic acid component consisting of at least 50 mol% of 3.3°, 4.4'-benzophenone tetracarboxylic acids and 50 mol% or less of pyromellitic acids;
5 mol% of 4,4°-diaminodiphenyl ether and 2
A polyimide compound consisting of an aromatic diamine component consisting of 5 mol % or less of p-phenyl diamine is known (Japanese Patent Application Laid-Open No. 187430/1983). Although this aromatic polyimide compound has high thermal decomposition temperature and high glass transition temperature and excellent heat resistance, the solvent in which it can be dissolved is limited to halogenated phenols, and it is difficult to dissolve in other general-purpose organic solvents. However, halogenated phenols, which can be used for dissolution, are more expensive than general-purpose phenolic solvents such as m-cresol, and have disadvantages such as being non-flammable and therefore not easy to dispose of. ing. Existing equipment that is configured to use general-purpose phenolic solvents such as m-cresol has the disadvantage that polyimide compounds that are soluble only in halogenated phenols as described above cannot be used. Furthermore, the resulting halogenated phenol solution of polyimide generally had a high viscosity of 500 voids or more (approximately 10% concentration by weight, 70° C.) and was unsatisfactory in terms of workability.

[Problems to be Solved by the Invention] As mentioned above, conventional organic solvent soluble polyimide compounds are generally more difficult than conventional insoluble aromatic polyimide compounds produced from pyromellitic acid and aromatic diamines. They had the disadvantage of having a low thermal decomposition temperature and/or a low glass transition temperature, and poor heat resistance, which is an important characteristic of polyimide compounds. Further, in the case of soluble polyimide compounds having excellent heat resistance, there is a problem in that they are soluble only in halogenated phenols, and general-purpose organic solvents such as m-cresol cannot be used.

Therefore, one purpose of the present invention is to solve these problems and provide a method for producing a polyimide compound that has high heat resistance equivalent to that of conventional insoluble aromatic polyimide compounds and is soluble in general-purpose organic polar solvents. It's about doing.

[Structure of the Invention] The present invention comprises two or more aromatic tetracarboxylic dianhydrides and a compound having the general formula (I) H2N-0-X-@-NH2-(I) [wherein, X is
-O-, -5-1-CO-1-so2-1-CONH-
1-(CH2)' n-(n is 1 to 4, preferably 1 to
is an integer of 2), or different, -CH3, -C2H
At least one aromatic diamine represented by The present invention provides a method for producing an organic solvent-soluble polyimide compound, which comprises synthesizing a polyamic acid by reacting it with a seed, and imidizing the polyamic acid.

The aromatic tetracarboxylic dianhydride used in the production method of the present invention refers to an aromatic tetracarboxylic dianhydride in which four carboxyl groups are directly bonded to an aromatic ring. Mellitic acid dianhydride, a, a-+,
C-benzophenone tetracarboxylic dianhydride, 3. a
-a, 4'-biphenyltetracarboxylic dianhydride, 3
．． ．． 3: 4,4°-biphenylsulfonetetracarboxylic dianhydride, 1,2,5.8-naphthalenetetracarboxylic dianhydride, 1,4,5.8-naphthalenetetracarboxylic dianhydride, 2, 3,8.7-naphthalenetetracarboxylic dianhydride, furantetracarboxylic dianhydride,
3.3; t,to-biphenyl ether tetracarboxylic dianhydride, 3.3; a,a'-dimethyldiphenylsilane tetracarboxylic dianhydride, 3.3; t,c-tetraphenylsilane tetra Carboxylic dianhydride, 3.
3-i, 4°-perfluoroisopropylidene diphenyltetracarboxylic dianhydride, 3°3°, 4,4°-isopropylidene diphenyltetracarboxylic dianhydride,
Examples include perylene-3,4,9,io-tetracarboxylic dianhydride, 3.3S4,4°-biphenylsulfide tetracarboxylic dianhydride, and the like.

In the production method of the present invention, it is essential to use two or more of the above-mentioned aromatic tetras and carboxylic dianhydrides in combination in order to obtain an organic solvent-soluble polyimide compound; Even when combined with an aromatic diamine, the resulting polyimide compound becomes insoluble in organic solvents. 2
When combining more than one type of aromatic tetracarboxylic dianhydride, each aromatic tetracarboxylic dianhydride does not exceed 37 mol% of the total amount of aromatic tetracarboxylic dianhydride, Preferably, it should not exceed 95 mol%, but if this condition is not met, it will be difficult to obtain the effect of using the aromatic tetracarboxylic dianhydride in combination, and the resulting polyimide compound will have insufficient solubility in organic solvents. There are many cases.

There is no particular restriction on the combination of two or more aromatic tetracarboxylic dianhydrides. For example, as a combination of two aromatic tetracarboxylic acids, pyromellitic dianhydride and 3,
3°, 4,4°-benzophenone tetracarboxylic dianhydride; 3.3°, 4.4°-benzophenone tetracarboxylic dianhydride and 3.3', 4,4'-biphenylsulfone tetracarboxylic acid dianhydride Acid dianhydride; 3.3", 4,4°-biphenyltetracarboxylic dianhydride and 3,3', 4.4°-benzophenonetetracarboxylic dianhydride; 3.3°, 4,4 °-Biphenyltetracarboxylic dianhydride and 3.3',4,4°-biphenylsulfonetetracarboxylic dianhydride; Pyromellitic dianhydride and 3.3',4,4°-biphenyl ether tetracal Pontic acid dianhydride: 1.2,5.13-naphthalenetetracarboxylic dianhydride and 3.3°, 4.4'-biphenylethertetracarboxylic dianhydride; 3.3-4,4° -dimethyldiphenylsilanetetracarboxylic dianhydride; 4,ao-dimethyldiphenylsilanetetracarboxylic dianhydride and 3.3',4.4"-benzophenonetetracarboxylic dianhydride; a,3 ; a,ao-dimethyldiphenylsilane tetracarboxylic dianhydride; 3,3°,4,4°-dimethyldiphenylsilane tetracarboxylic dianhydride and 3,3-t,a'-isopropylidene Diphenyltetracarboxylic dianhydride: 3,3',4.4°-tetraphenylsilane tetracarboxylic dianhydride and pyromellitic dianhydride; 3,3'.
4.4'-Tetraphenylsilane tetracarboxylic dianhydride and 3,3°,4.4'-benzophenonetetracarboxylic dianhydride; 3,3°,4,4°-tetraphenylsilane tetracarboxylic acid Dianhydride and 3.3",4.4-biphenylsulfonetetracarboxylic dianhydride: 3,3',4.4'-perfluoroisopropylidene diphenyltetracarboxylic dianhydride and pyromellitic dianhydride 3,3;4,4°-perfluoroisopropylidene diphenyltetracarboxylic dianhydride and 3.3′,4,4°
-Henzophenone Tetracarpone brewed wood: 3, 3°
, 4.4'-perfluoroisopropylidene diphenyltetracarboxylic dianhydride and 3.3', 4.4°-biphenylsulfone tetracarboxylic dianhydride: a, 3; a
, ao-isopropylidene diphenyltetracarboxylic dianhydride and pyromellitic dianhydride; a, 3a, ao-
Isopropylidene diphenyltetracarboxylic dianhydride and 3,3°,4,4-benzophenonetetracarboxylic dianhydride; 3,3; a,ao-isopropylidene diphenyltetracarboxylic dianhydride; 3. 3',4,4'-biphenylsulfonetetracarboxylic dianhydride; perylene-3.4,LIG-tetracarboxylic dianhydride and 3,3',4,4°-benzophenonetetracarboxylic dianhydride : perylene-3.4.9,to-tetracarboxylic dianhydride and 3,ala,c-perfluoroisopropylidene diphenyltetracarboxylic dianhydride; acid dianhydride; 3,3;4,a' -biphenylsulfidetetracarboxylic dianhydride and 3,3',4,4'-benzophenonetetracarboxylic dianhydride; 3,3',4,4°-biphenylsulfidetetracarboxylic dianhydride and 3, 3°,4.4'-biphenylsulfone tetracarboxylic dianhydride; 3,3',4,ao-biphenylsulfide tetracarboxylic dianhydride and 3.3°,4,4'-biphenyl ether tetracarpon Examples include acid dianhydrides,
Further, as a combination of three aromatic tetracarboxylic acids, pyromellitic dianhydride, 3,3°,4,4°-benzophenonetetracarboxylic dianhydride, 3.3', 4.
4°-biphenylsulfone tetracarboxylic dianhydride:
Pyromellitic dianhydride and 3,3°,4,4°-benzophenonetetracarboxylic dianhydride and 3.3', 4.
4'-biphenyltetracarboxylic dianhydride; 3,3',4,4°-benzophenonetetracarboxylic dianhydride and 3,3',4,4°-biphenylsulfonetetracarboxylic dianhydride and 3 ,3°,4,4°-biphenyltetracarboxylic dianhydride; 1,'2,5.6 naphthalenetetracarboxylic dianhydride and 3,3',4,4°-benzophenonetetracarboxylic dianhydride Anhydride and 3,3°,4,4-biphenylsulfonetetracarboxylic dianhydride; 1,2,5,8-naphthalenetetracarboxylic acid dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride Pontic acid dianhydride and 3,3°. 4,4°-Biphenyl ether tetracarboxylic dianhydride: Pyromellitic dianhydride and 3.3°, 4.4-benzophenonetetracarboxylic dianhydride and 3,3°, 4,4°
-Biphenyl ether tetracarboxylic dianhydride; pyromellitic dianhydride and 3.3',4.4'-benzophenonetetracarboxylic dianhydride and 3.3;i,4°-isopropylidene diphenyltetracarpone Acid dianhydride; Pyromellitic dianhydride and 3,3°,4.4'-henzophenonetetracarboxylic dianhydride and 3.3; 4.
4'-berfluoroisopropylidene diphenyltetracarboxylic dianhydride; pyromellitic dianhydride and 3.3',4.4'-benzophenonetetracarboxylic dianhydride and a, 3; t, ao
-dimethyldiphenylsilanetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3°,4,4°-benzophenonetetracarboxylic dianhydride, and 3.31. i, +
°-Tetraphenylsilane tetracarboxylic acid dianhydride;
Pyromellitic dianhydride and 3.3',4,4°-isopropylidene diphenyltetracarboxylic dianhydride and 3°3°,4,4°-benzophenonetetracarboxylic dianhydride; perylene-3, 4,11,10-tetracarboxylic dianhydride, 3,3°, 4,4′-benzophenonetetracarboxylic dianhydride, and 3,3′,4,4°-biphenylsulfone tetracarboxylic dianhydride; Pyromellitic dianhydride and 3.3', 4.4'-benzophenonetetracarboxylic dianhydride and 3.3', 4,
Examples include 4"-biphenyl sulfide tetracarboxylic dianhydride.

As described above, various combinations of aromatic tetracarboxylic acids are possible, but it is important that the resulting polyimide compound has particularly excellent heat resistance and organic solvent solubility, and that the aromatic tetracarboxylic dianhydride used can be obtained or synthesized. The following combinations are particularly preferable because they are easy to use.

Pyromellitic dianhydride and 3,3°, 4.41-Hensephenonetetracarboxylic dianhydride; 3.3°, 4'-benzophenonetetracarboxylic dianhydride and 3.3°, 4 .4°-biphenylsulfonetetracarboxylic dianhydride; pyromellitic dianhydride and 3,3°, 4.4°-benzophenonetetracarboxylic dianhydride and 3,3°, 4.4
°-Biphenylsulfonetetracarboxylic dianhydride; pyromellitic dianhydride and 3.3°, 4,4°-biphenyltetracarboxylic dianhydride; 3.3°, 4.4'-hensiphenotetra Carboxylic dianhydride and 3,3°,4.4'-biphenyltetracarboxylic dianhydride; 3.3°,414°-biphenyltetracarboxylic dianhydride and 3.3',4.4'- Biphenylsulfonetetracarboxylic dianhydride: Pyromellitic dianhydride and 3,3°, 4.4'-benzophenonetetracarboxylic dianhydride and 3.3°, 4.4
°-Biphenyltetracarboxylic acid anhydride: 3.3°
, 4,4°-perfluoroisopropylidene diphenyltetracarboxylic dianhydride and pyromellitic dianhydride; 3.3′,4,4°-perfluoroisopropylidene diphenyltetracarboxylic dianhydride and 3.3 ', 4.
4'-Hensephenonetetracarboxylic dianhydride: Pyromellitic dianhydride and 3,3°,4.4-benzophenonetetracarboxylic dianhydride and 3.3;4,4'-perfluoroisopropylidene Diphenyltetracarboxylic dianhydride.

In the production method of the present invention, specific examples of aromatic diamines used in combination with aromatic tetracarboxylic dianhydride include 4.4'-diaminodiphenyl ether, 4,4°-diaminodiphenyl sulfide, and 4.4'-diaminodiphenyl ether. -diaminobenzophenone, 4,4'-diaminodiphenylsulfone,
4,4°-diaminophthalamide, 4.4°-diaminodiphenylmethane, 4,4°-diaminodiphenylethane, 2.2-bis(4-aminophenyl)furopane,
2.2-bis(4-aminophenyl)hexafluoropropane, 3,3-bis(4-aminophenyl)pentane, 2.2-bis(4-aminophenyl)butane, bis(4-aminophenyl)dichloromethane, screw (4-7
minophenyl) dibromomethane, bis(4-aminophenyl)octafluorobutane, 2,2-bis(4-aminobutane)decafluoropentane, 2,2-bis(4
-7minophenyl)octafluorobutane.

In the production method of the present invention, the above-mentioned aromatic diamines can be used alone or in combination of two or more.
When combining two or more types of aromatic diamines, there are no particular restrictions on the combination. For example, a combination of two types of aromatic diamines is 4.4"-diaminodiphenyl ether and 4.4°-diaminodiphecolmethane. ; 4.4°-diaminodiphenyl ether and 4.4′-diaminodiphenyl sulfone; 4.4°-diaminodiphenylmethane and 4.4°-diaminodiphenylsulfone; 4.4°-diaminobenzophenone and 4.4′-diaminodiphenyl ether : 4.4°-diaminobenzophenone and 4.4°-diaminodiphenylmethane; 4.4°-diaminobenzophenone and 4.4°-diaminodiphenylsulfone; 2.2-bis(4-aminophenyl)hexafluoropropane 4,4′-diaminodiphenyl ether; 2.
2-bis(4-7minophenyl)hexafluoropropane and 4,4'-diaminodiphenylmethane; 2,2-bis(4-aminophenyl)hexafluoropropane and 4
．． 4"-diaminodiphenylsulfone; 2,2-bis(
4-aminophenyl)hexafluoropropane and 4.4
°-Diaminobencif enone; 2.2-bis(4-aminophenyl)propane and 4°4°-diaminodiphenyl ether; 2.2-bis(4-7minophenyl)propane and 4°4
'-Diaminodiphenylmethane: 2.2-bis(4-7minophenyl)propane and 4゜4
°-Diaminodiphenylsulfone: 2.2-bis(4-aminophenyl)propane and 4°4
゛-Diaminobenzophenone: 2.2-bis(4-7minophenyl)propane and 2゜2
-Bis(4-aminophenyl)hexafluoropropane, etc., and combinations of three aromatic diamines include 4.4°-diaminodiphenyl ether, 4.4°-diaminodiphenylmethane, and 4.4° -diaminodiphenyl sulfone; 4', 4'-diaminodiphenyl ether and 4.4
'-Diamino diphenylmethane and 4.4°-diaminobenzophenone; 4.4°-diaminodiphenyl ether and 4,4°-diaminodiphenylmethane and 2.2-bis(4-7minophenyl)hexafluoropropane; 4.4°- Diaminodiphenyl ether and 4. &°-diaminodiphenylmethane and 2,2-bis(4-7minophenyl)propane; 4.4°-diaminodiphenyl ether and 4,4"-diaminobenzophenone and 4,4°-diaminodiphenyl sulfone; 4.4°-diamino Diphenylmethane and 4,4°-diaminobenzophenone and 4,4′-diaminodiphenylsulfone; 4.4°-diaminodiphenylmethane and 4.4°-diaminodiphenylsulfone and 4.4′-diaminobenzophenone; 4.4°-diamino Diphenylmethane and 2,2-bis(
4-7minophenyl)propane and 2,2-bis(4-aminophenyl)hexafluoropropane: 4.4°-
Diaminodiphenyl ether, 2,2-bis(4-aminophenyl)furopane, and 2,2-bis(4-aminophenyl)hexafluoropropane; 4.4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, and 4 .4'-Diaminobenzophenone; 4.4°-diaminodiphenylmethane, 4.4°-diaminodiphenylsulfone, and 4.4°-diaminobenzophenone; 4.4°-diaminodiphenylmethane, 4,4°-diaminodiphenylsulfone, and 2 , 2-bis(4-7minophenyl)hexafluoropropane; 4.4′-diaminodiphenylmethane and 4,4′-diaminodiphenylsulfone and 2.2-bis(4-aminophenyl)propane; 4.4′- Diaminodiphenyl sulfone, 2,2-bis(4-aminophenyl)propane, and 2,2-bis(4-
aminophenyl)hexafluoropropane: 4.4°-
Examples include diaminobenzophenone, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, and the like.

To carry out the production method of the present invention, first, an aromatic tetracarboxylic dianhydride and an aromatic diamine are reacted in an organic solvent to synthesize a polyamic acid. The obtained organic solvent solution of the polyamic acid is used as it is, or the polyamic acid is recovered from the organic solvent solution by a conventional method, purified if necessary, and then dissolved in the organic solvent again and subjected to the imidization reaction.

The reaction ratio of aromatic tetracarboxylic dianhydride and aromatic diamine is preferably carried out in equimolar terms, but the ratio of these monomers may be slightly varied as long as the desired polyamic acid is obtained. 0 For example, in order to obtain a high molecular weight polyamic acid, it is preferable to use about 0.7 to 1.3 moles of aromatic diamine per 1 mole of aromatic tetracarboxylic dianhydride; The molecular weight of the polyamic acid can also be adjusted by adding substances. The reaction temperature when producing polyamic acid is generally 0 to 100°C, preferably 5 to 6°C.
The reaction time is generally 10 minutes to 50 hours, and usually completed in 30 minutes to 25 hours, although the reaction time depends on the types of aromatic tetracarboxylic dianhydride and aromatic diamine. Also,
As the organic solvent used in this reaction, aprotic polar solvents are generally preferred, such as N-methyl-2-
pyrrolidone, N,N-dimethylacetamide, N,N-
Dimethylformamide, dimethylsulfoxide, tetramethylurea, hexamethylphosphoric triamide, γ-butyrolactone, and the like can be mentioned. In addition to these aprotic polar solvents, there are general organic solvents such as phenols, ketones, esters, lactone a, ethers, cellosolves, halogenated hydrocarbons, and hydrocarbons such as phenol.

m-cresol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate,
Ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, γ-butyrolactone, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, diglyme.

Methyl cellosol, ethylene glycol methyl ether, diethylene glycol, methyl ether, dichloromethane, 1,2-dichloroethane, 1゜4-dichlorobutane, trichloroethane, chlorobenzene, 0-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene etc. can also be used. The amount of the solvent used is usually such that the concentration of the aromatic tetracarboxylic dianhydride and aromatic diamine in units of 1,000 to the solvent is 3 to 50% by weight, preferably 5 to 30% by weight. .

The polyamic acid thus obtained is then subjected to an imidization reaction. In this imidization reaction, the above-mentioned aprotic polar solvent is suitably used as a solvent. Therefore, when an aprotic polar solvent is used in the above reaction between aromatic tetracarboxylic dianhydride and aromatic diamine, the obtained polyamic forge solution can be used as it is in the imidization reaction. . When an organic solvent other than an aprotic polar solvent is used in the reaction between aromatic tetracarboxylic dianhydride and aromatic diamine, polyamic acid is recovered by a conventional method and purified as necessary. After that, it is preferable to dissolve it again in an aprotic polar solvent and carry out the imidization reaction.

As a method for imidizing polyamic acid, an organic solvent solution of polyamic acid obtained in this way is
A method of advancing the imidization reaction by heating to 50 ° C., a method of advancing the imidization reaction by heating an organic solvent solution of polyamic acid at 60 to 150 ° C. and distilling off the water produced in the reaction out of the system. A method may be used in which a tertiary amine is added as needed in the presence of an organic carboxylic acid anhydride, and the polyamic solution is heated to advance the imidization reaction.

Generally, the last method among the above-mentioned methods is preferred because the imidization reaction can be easily controlled.

In this method, the concentration of the polyamic acid solution in an organic solvent is preferably 1 to 50% by weight, particularly preferably 1 to 30% by weight.
Weight%. Further, the boiling point of the organic carboxylic acid anhydride used during the imidization reaction is preferably 250°C or lower. If the boiling point of the organic carboxylic acid anhydride exceeds 250°C, the organic carboxylic acid anhydride will not be removed at the same time during the process of removing the solvent by heating when forming a film using the imidization reaction solution as it is, and It will remain and have an adverse effect on physical properties, etc. Examples of such organic carboxylic anhydrides include acetic anhydride, propionic anhydride, acetic anhydride, isobutyric anhydride, and valeric anhydride. Mixed acid anhydrides of these organic carboxylic acids, such as acid anhydrides obtained from acetic acid and phosphoric acid, can also be used. When using an organic carboxylic acid anhydride, the amount used is 0 per mole of repeating structural unit of polyamic acid.
．． The amount is preferably 2 to 20 times the mole. If the amount is less than 0.2 times the mole, the imidization reaction will proceed slowly, and the solubility of the polyamic acid in the organic solvent will decrease if the amount exceeds 20 times the mole. Furthermore, when an organic carboxylic acid anhydride is used, a tertiary amine can be added as a catalyst if necessary to promote the imidization reaction.
In addition to promoting the imidization reaction, the class amine also has the effect of suppressing a decrease in the solution viscosity of the resulting polyimide.

The tertiary amine preferably has a boiling point of 250° C. or lower for the same reason as in the case of organic carboxylic acid anhydrides, such as aliphatic tertiary amines such as triethylamine, tripropylamine, and tributylamine;

Aromatic 14-tertiary amines such as N-dimethylaniline, pyridine, 2-methylpyridine, N-methylimidazole,
Examples include heterocyclic compounds such as quinoline and isoquinoline. The amount of tertiary amine added is preferably 20 times the mole or less per mole of repeating structural units of the polyamic acid; if it exceeds 20 times the mole, the solubility of the polyamic acid in organic solvents tends to decrease. The reaction temperature of the imidization reaction when using an organic carbon anhydride is preferably 0 to 2.
00°C, particularly preferably 20 to 170°C. If the temperature is below 0°C, the progress of the imidization reaction will be delayed, and if it exceeds 200°C, the molecular weight of the polyimide will decrease. The organic carboxylic acid anhydride and the tertiary amine may be added in any order, or may be added after mixing them.

The polyimide compound thus obtained is produced by casting or spin coating a solution of the polyimide compound in an organic solvent onto the smooth surface of a base material such as a glass plate or metal plate, and then applying the organic solvent by heating or other methods. It can be made into a film by removing. Alternatively, after the polyimide compound is recovered from the organic solvent solution of the polyimide compound after the reaction, it can be dissolved again in the organic solvent and then formed into a film by the above method. Examples of the organic solvent used for this redissolution include the aforementioned aprotic polar solvents and phenolic solvents.

Intrinsic viscosity η of the polyimide compound obtained in this way
1 nh (concentration 0.5 g 7100 ml, solvent m-cresol, temperature 30° C.) is preferably o, o5 dl/g or more, particularly preferably 0.05 to 20 dl/g. If the intrinsic viscosity is less than 0.05 dl/g, the moldability will be insufficient and undesirable.The intrinsic viscosity ηinh is expressed as (t is the flow rate of the polymer solution, and to is the flow rate of m-cresol). viscosity.

[Effects of the Invention] The polyimide compound obtained by the production method of the present invention is soluble in general-purpose polar organic solvents, so it is extremely convenient for producing homogeneous films, etc., and has a high thermal decomposition temperature and high glass transition temperature. The polyimide compound of the present invention has excellent heat resistance comparable to conventional solvent-insoluble aromatic polyimide compounds.The polyimide compound of the present invention also has high storage stability in a solution state, and has excellent mechanical properties, electrical properties, It also has excellent chemical resistance, and is useful for high-temperature films, adhesives, paints, etc. Specifically, it can be used as printed wiring boards, flexible wiring boards, surface protection films for semiconductor integrated circuit elements, or living room insulation films. , liquid crystal alignment film, coating material for enameled electric wires,
Useful for various laminates, gaskets, etc.

[Example 1] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited by these Examples.

1" 4,4°-diaminodiphenyl ether (hereinafter referred to as D'DE) 20.00 g (100
3,3°,4,4°-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA dianhydride) was dissolved in 200+*l of dimethylformamide (hereinafter referred to as DMF), and the solution was kept at 25°C without stirring. ) 8.08
g (25 mmol) and 3.3',4.4'-biphenylsulfonetetracarboxylic dianhydride (hereinafter referred to as BSTA) 2B, 8Bg (75 mmol) were quickly added as powders and allowed to react at 25°C for 8 hours. Polyamic acid was synthesized.

Add 200ml of DMF to the obtained polyamic acid solution.
After diluting by adding 47.40 g of pyridine and 102.011 g of acetic anhydride, the mixture was allowed to react at room temperature for 1 hour. After the reaction, the resulting reaction mixture was poured into methanol to solidify the polyimide compound produced. It was collected and vacuum dried. The obtained polyimide compound was soluble in m-cresol.

The infrared absorption spectrum of this polyimide compound is shown in FIG. It was found that imidization was proceeding. Table 1 shows the intrinsic viscosity ηinb of the intermediate product polyamic acid and the obtained polyimide compound, as well as the lθ% thermal decomposition temperature and glass transition temperature of the polyimide compound.

2-12, 1-11 Polyamic acid was prepared in the same manner as in Example 1, except that the types and amounts of aromatic tetracarboxylic dianhydride and aromatic diamine used were changed as shown in Table 1. A polyimide compound was produced through the following steps.

(The polyimide compounds obtained in Examples 2 to 1O were all soluble in phenolic solvents such as m-cresol, 0-cresol, p-cresol, and phenol. Table 1 shows the intrinsic viscosity ηinh of the polyimide compound obtained, as well as the 10% thermal decomposition temperature and glass transition temperature of the polyimide compound. In addition, when the infrared absorption spectrum of the polyimide compound obtained in Examples 2 to 1O was measured, In both cases, 1780cm-'' and 1720c as in Example 1.
Absorption based on the carbonyl stretching vibration of the imide carbonyl group accompanying imide ring formation was observed in m-', and it was found that at least 85% of imidization had progressed in these polyimide compounds. The infrared absorption spectra of the polyimide compounds of Examples 3 and 5 were
As shown in FIG.

(2) In Comparative Examples 1 to 9, a polyimide compound precipitated immediately after adding acetic anhydride of pyridine as an imidizing agent to imidize the synthesized polyamic acid. The obtained polyimide compound was insoluble in both phenolic solvents and aprotic polar solvents. Table 1 shows the results of measuring the intrinsic viscosity ηinh of the intermediate product polyamic acid, the 10% thermal decomposition temperature and the glass transition temperature of the obtained polyimide compound in the same manner as in Example 1.

Aromatic diamine D D Eo, 100 used in Comparative Example 1
Instead of mol, 0.100 mol of 3,3°-dicroconi4.4°-diaminodiphenylmethane was charged, 413 g of m-cresol was added, and the temperature was raised from room temperature to 180°C for 5 mol.
The reaction was carried out for a period of time, and polymerization and imidization were performed in one step. It was confirmed from the infrared absorption spectrum that imidization of at least 85% of the obtained polymer had progressed.

Moreover, ηinh of the obtained polyimide is 0.78d
l/g (in m-cresol), the 10% pyrolysis temperature was 515°C, and the glass transition temperature was 268°C.

Aromatic diamine used in Comparative Example 12, using 2°4-diaminotoluene instead of 3.3°-dichloro-4,4'-diaminodiphenylmethane, and reacting in the same manner as in Comparative Example 12. Synthesized polyimide. It was confirmed from the infrared absorption spectrum that imidization of at least 95% of the obtained bolya had progressed.

Moreover, the ηink of the obtained polyimide is 0.48 dl
/g (in m-cresol). The 10% pyrolysis temperature was 485°C, and the glass transition humidity was 290"C'.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, and FIG. 3 show Example 1.3, respectively.
and 5 show the infrared absorption spectrum of the polyimide compound produced in 5.

Claims (1)

[Claims] Two or more aromatic tetracarboxylic dianhydrides and a general formula: ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, X is -O-, -S-, -CO- , -SO_2
-, -CONH-, -(CH_2)n- (n is an integer from 1 to 4) ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (R and R' are the same or different, lower alkyl group, fluorine-substituted lower represents a divalent group selected from the group consisting of an alkyl group and a halogen atom] An organic solvent obtained by synthesizing a polyamic acid by reacting it with at least one aromatic diamine represented by the following and imidizing the polyamic acid. Method for producing soluble polyimide compounds.