JPH0315660B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a soluble polyimide compound. Generally, polyimide compounds have excellent heat resistance and are therefore very useful as raw materials for films, wire coatings, adhesives, paints, etc. that are used at high temperatures. Conventional polyimide compounds are produced by polymerizing aromatic tetracarboxylic acid dianhydride such as pyromellitic anhydride and aromatic amine in a polar solvent to obtain aromatic polyamic acid, and then using this solution as a base material. A film-like aromatic polyimide compound is known which is obtained by coating, forming into a film, and then dehydrating and ring-closing it by a method such as heating. However, in conventional aromatic polyimide 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 long period of time, part of the polyamic acid solution undergoes dehydration and ring closure. It has the disadvantage that it becomes polyimide, becomes insolubilized, and becomes cloudy. For this reason, conventional solutions of aromatic polyamic acid have to be stored at low temperatures and have the drawback of requiring care in handling. The present applicant previously discovered that a solution of polyamic acid produced from 2,3,5-tricarboxycyclopentyl acetic acid or its anhydride and a diamine has excellent storage stability at room temperature, and that the polyamic acid The company filed a patent application for an invention based on the knowledge that polyimide compounds obtained by dehydrating and ring-closing polyimide compounds have excellent heat resistance, mechanical properties, electrical properties, chemical resistance properties, etc. (Patent Application No. 56-205099, No. 57-26095, No. 57
-21294 and 57-21295). As a result of further intensive research, the present inventors found that 2.
When polyamic acid produced from 3,5-tricarboxycyclopentyl acetic acid or its anhydride and a diamine is subjected to an imidization reaction in the presence of an organic carboxylic acid anhydride in an organic solvent solution state, a polyimide soluble in the solvent is formed. The polyimide compound solution obtained in this way can be applied to a base material to form a film, which can be easily peeled off from the base material, has excellent workability, and is easy to form into a film. The present invention was achieved by discovering that there is little shrinkage and excellent various dynamics. An object of the present invention is to produce a polyimide compound that has excellent heat resistance, mechanical properties, electrical properties, chemical resistance properties, etc., has excellent workability during film production, and has little shrinkage during film production and is soluble in solvents. The purpose is to provide a method. That is, the present invention is characterized in that polyamic acid obtained from 2,3,5-tricarboxycyclopentyl acetic acid or its anhydride and a diamine is subjected to an imidization reaction in the presence of an organic carboxylic acid anhydride in an organic solvent solution state. The present invention provides a method for producing a soluble polyimide compound. 2,3,5-tricarboxycyclopentyl acetic acid (hereinafter referred to as TCA) used in the present invention is
For example, a method of ozonolyzing dicyclopentadiene and oxidizing it with hydrogen peroxide (British Patent No. 872355,
J.Org.Chem., 28 , 2537 (1963)), or a method of oxidizing hydroxydicyclopentadiene obtained by hydrating dicyclopentadiene with nitric acid (West German Patent No. 1078120). By dehydrating this TCA, 2,3,5
-Tricarboxycyclopentyl acetic anhydride (hereinafter referred to as TCA/AH) can be produced. In addition, the diamine to be reacted with the above TCA or TCA・AH is a compound represented by the general formula: H ₂ N-R-NH ₂ (R represents a divalent aromatic group, aliphatic group, or alicyclic group) It is. Preferred R in the above general formula is, for example,

【formula】

【formula】

【formula】

(In the formula, X ₁ , X ₂ , X ₃ and X ₄ may be the same or different, -H, -CH ₃ or -OCH ₃ , Y is -
CH ₂ −, −C ₂ H ₄ −, −O−, −S−,

【formula】

[Formula] -SO ₂ - or -CONH-, n represents 0 or 1) aromatic group, -(CH ₂ ) _o -
(n=2-20),

【formula】 【formula】

Examples include aliphatic groups or alicyclic groups having 2 to 20 carbon atoms represented by the formula. In order to further improve the heat resistance of the polyimide compound obtained by imidizing polyamic acid in an organic solvent solution state in the method of the present invention, it is preferable that R is an aromatic group. Specific examples of the above diamine include paraphenylenediamine, metaphenylenediamine, 4,4'-
Diminodiphenylmethane, 4,4'-diaminodiphenyl ethane, benzidine, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,4'-diaminobenzanilide, 3,4'-diaminodiphenyl ether, metaxylylene diamine, paraxylylene diamine Amine, ethylenediamine, 1,3-
Propanediamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, nonamethylene diamine, 4,4'-dimethylheptamethylene diamine, 1,4-diaminocyclohexane, tetrahydrodicyclopentadiene Examples include diamine, hexahydro-4,7-methanoindani dimethylene diamine, tricyclo[6,2,1,0 _2.7 ]-undecylene dimethyldiamine, and the like. These can be used alone or in combination. When carrying out the method of the present invention, first, TCA
Alternatively, a solution of polyamic acid in an organic solvent is obtained by reacting TCA·AH and a diamine in an ordinary organic solvent. The obtained organic solvent solution of polyamic acid may be used as it is, or after recovering polyamic acid from the organic solvent solution by a conventional method and purifying it as necessary,
It is dissolved again in an organic solvent, and if desired, a tertiary amine is added thereto to carry out an imidization reaction in the presence of an organic carboxylic acid anhydride. Examples of organic solvents used in the imidization reaction in the present invention include polar solvents such as N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, tetramethylurea, and hexamethylphosphorotriamide. used. The reaction ratio of TCA or TCA·AH and 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. For example, in order to obtain high molecular weight polyamic acid, 0.7 to 1.3 of diamine is required per mole of TCA or TCA・AH.
It is preferable to use about molar amount. The molecular weight of polyamic acid can also be adjusted by adding monoamines or dicarboxylic acid anhydrides. The reaction temperature when producing polyamic acid is usually 50 to 300°C when using TCA, preferably 100 to 250°C,
When using TCA/AH, the temperature is 0 to 100°C. Generally, TCA and TCA・AH are TCA・AH,
In particular, it is preferable to use a dianhydride, which facilitates the production of polyamic acid soluble in organic solvents. In addition to the above-mentioned polar solvents, as organic solvents for reacting TCA or TCA/AH with diamines, general organic solvents such as alcohols, phenols, ketones, esters, lactones, ethers, and halogens can be used. hydrocarbons, hydrocarbons such as methyl alcohol, ethyl alcohol, isopropyl alcohol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, 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, dichloromethane, 1,2-dichloroethane , 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene,
Hexane, heptane, octane, benzene, toluene, xylene, etc. can also be used. In particular, when the above-mentioned polar solvent and a general organic solvent are mixed and used, it becomes easier to obtain a high molecular weight polyamic acid. For example, acetone/dimethylformamide =
TCA・AH using a solvent of about 7/3 (volume ratio)
When the diamine is reacted with the diamine, the reaction system becomes homogeneous, and it becomes easy to obtain particularly high molecular weight polyamic acid. When TCA or TCA・AH and diamine are reacted using these general organic solvents,
Generally, the produced polyamic acid is recovered and imidized again as a solution in the polar solvent. The intrinsic viscosity ηinh of the polyamic acid thus obtained (concentration 0.5 g/100 ml, solvent N,N'-dimethylacetamide, measurement temperature 30°C) is preferably
0.05 dl/g or more, particularly preferably 0.05 to 20 dl/g
It is. The intrinsic viscosity ηinh is ηinh=1n(t/to)/0.5 (t is the flow rate of the polymer solution, to is N,
It is the viscosity expressed as , which is the flow rate of N'-dimethylacetamide. The concentration of the organic solvent solution of polyamic acid used in the present invention is preferably 1
-50% by weight, particularly preferably 1-30% by weight. The boiling point of the organic carboxylic acid anhydride used in the present invention 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 during film formation, and will remain in the film, which will have a negative impact on physical properties. give. Examples of such organic carboxylic anhydrides include acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, and valeric anhydride. Mixed acid anhydrides of these organic carboxylic acids, such as acid anhydrides obtained from acetic acid and propionic acid, can also be used. The amount of organic carboxylic acid anhydride added is preferably 0.2 to 20 moles per mole of repeating structural unit of polyamic acid. When the amount is less than 0.2 times the mole, the imidization reaction progresses slowly, and when it exceeds 20 times the mole, the solubility of polyamic acid in the organic solvent decreases. When carrying out the method of the present invention, in order to promote the imidization reaction, if desired, 3
grade amines can be added. In addition to promoting the imidization reaction, the tertiary amine also has the effect of suppressing a decrease in the solution viscosity of the resulting polyimide compound. The tertiary amine used in the present invention has a boiling point of 250°C for the same reason as the organic carboxylic anhydride.
The following are preferred, such as aliphatic tertiary amines such as triethylamine, tripropylamine, and tributylamine, aromatic tertiary amines such as N,N-dimethylaniline, pyridine, 2-methylpyridine, N-methylimidazole, and quinoline. Examples include heterocyclic compounds such as. The amount of tertiary amine added is preferably 20 times or less in mole per mole of repeating structural unit of polyamic acid.
When the amount exceeds 20 times the molar amount, the solubility of polyamic acid in organic solvents tends to decrease. In the method of the present invention, the imidization reaction is carried out by heat-treating the organic solvent solution of polyamic acid obtained in the reaction as it is, or by collecting the produced polyamic acid, and then purifying it as necessary and using it for producing polyamic acid. This is carried out by redissolving the solvent in the same or different organic solvent and heat-treating it. The reaction temperature of the imidization reaction is preferably 60 to 200°C,
Particularly preferred is 100 to 170°C. If the temperature is lower than 60°C, the progress of the imidization reaction will be delayed, and if the temperature exceeds 200°C, the molecular weight of the polyimide compound will decrease significantly. 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
By casting an organic solvent solution of the polyimide compound after reaction onto a substrate such as a glass plate or metal plate, and then removing the organic solvent, organic carboxylic acid anhydride, and tertiary amine by heating or other methods. Can be made into film. Alternatively, after the polyimide compound is recovered from the organic solvent solution of the polyimide compound after the reaction, it can be redissolved in the organic solvent and then formed into a film by the above method. Examples of the organic solvent used for this redissolution include, in addition to the above-mentioned polar solvents, solvents that dissolve the polyimide compound of the present invention, such as phenolic solvents such as metacresol. The polyimide compound obtained by the method of the present invention has excellent heat resistance, mechanical properties, electrical properties, chemical resistance properties, etc., and is also excellent in workability during film production, has little shrinkage during film formation, and can be used at high temperatures. It is useful for films, adhesives, paints, etc. Specifically, it is used as a surface protective film for printed wiring boards, flexible printed wiring boards, and semiconductor integrated circuit elements.
It can be used in a wide range of applications, including as a coating for enameled wires and as an electrical insulating material for various laminates. EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited to these Examples. Example 1 Diaminodiphenyl ether (DDE) 20.48g
(0.102 mol) was dissolved in 247.5 g of N,N-dimethylacetamide (DMAc).
23.15 g (0.103 mol) of anhydride) was added as a powder and reacted at 25° C. with stirring. After 24 hours, a small amount of this reaction solution was sampled, DMAc was added thereto so that the concentration of polyamic acid was 0.5 g/100 ml, and the intrinsic viscosity (30° C.) was measured. The obtained polyamic acid had an ηinh of 2.01 dl/g. Next, DMAc was further added to the reaction solution to make the polyamic acid concentration 6.1% by weight, making 30 g of a solution.
Transfer to a 100ml flask and add acetic anhydride to this solution.
1.32g (3 times the mole per mole of repeating structural unit of polyamic acid) and 1.02g of pyridine (also 3 times the mole per mole of repeating structural unit of polyamic acid)
2 times the mole), mixed and stirred, and heated to 135℃
The mixture was allowed to react for 2 hours. Next, the reaction product was poured into a large amount of methanol to coagulate and collect the polymer, which was then dried at 80°C overnight. of the obtained polymer
The viscosity ηinh at 30°C in DMAc was 1.31 dl/g. This polymer was dissolved again in DMAc, cast on a glass plate, dried, and then the film was peeled off to measure the infrared absorption spectrum. The results are shown in FIG. As is clear from FIG. 1, absorption based on the C=0 stretching vibration of imide was observed at 1740 cm ^-1 and 1690 cm ^-1 . This shows that a polyimide compound can be obtained by heating and reacting a polyamic acid solution in the presence of acetic anhydride and pyridine. Note that FIG. 2 shows the infrared absorption spectrum of polyamic acid in this example. Example 2 The amounts of acetic anhydride and pyridine added were changed as shown in Table 1, and the other conditions were the same as in Example 1.
A polyimide compound with a yield of 1.48 dl/g was obtained. Example 3 The amounts of acetic anhydride and pyridine added were changed as shown in Table 1, and the other conditions were the same as in Example 1, and ηinh
A polyimide compound with a yield of 1.51 dl/g was obtained. Example 4 A polyimide compound having an ηinh of 1.15 dl/g was obtained in the same manner as in Example 3 except that pyridine was not used. Example 5 In the same manner as in Example 1 except that N,N-dimethylaniline was used instead of pyridine, ηinh
A polyimide compound with a weight of 0.79 dl/g was obtained. Example 6 Triethyleneamine was used instead of pyridine, and the other conditions were the same as in Example 1, and ηinh was 1.12.
A polyimide compound of dl/g was obtained. Example 7 Using propionic anhydride instead of acetic anhydride,
The rest was the same as in Example 2, and ηinh was 1.18dl/
A polyimide compound of g was obtained. Example 8 Polyamic acid was obtained in the same manner as in Example 1 except that N,N-dimethylformamide (DMF) was used instead of DMAc. The obtained polyamic acid was measured as a DMAc solution, and the ηinh of the polyamic acid was 2.71 dl/g. Next, DMF was added to this polyamic acid solution to dilute it to 6.0% by weight, and acetic anhydride (5 times the mole per mole of repeating structural unit of polyamic acid) and pyridine (also 7 times the mole) were sequentially added and mixed.
After stirring, the mixture was reacted at 135°C for 2 hours. The obtained polyimide compound was measured as a DMAc solution, and the ηinh of the polyimide compound was 1.50 dl/g. Example 9 Diaminophenylmethane (DDM) was used instead of DDE.
Polyamic acid was obtained in the same manner as in Example 1 except that ηinh of the obtained polyamic acid is
It was 2.33 dl/g. Next, DMAc was added to this polyamic acid solution to dilute it to 6.0% by weight, and acetic anhydride (5 times the mole per mole of repeating structural unit of polyamic acid) and pyridine (also 7 times the mole) were sequentially added, mixed, and stirred. After that, the mixture was reacted at 135°C for 2 hours. The obtained polyimide compound had an ηinh of 0.91 dl/g. Comparative Example 1 Polyamic acid was synthesized from pyromellitic anhydride and diaminodipheniether in DMAc in the same manner as in Example 1. The obtained polyamic acid had an ηinh of 2.02 dl/g. Next, DMAc was added to this polyamic acid solution to make it 6.0% by weight, and then acetic anhydride (5 times the mole per mole of repeating structural unit of polyamic acid) and pyridine (also 7 times the mole) were added, mixed, and stirred. When the reaction was carried out at 135°C for 2 hours, a solid precipitated and it was not possible to obtain a soluble polyimide compound. The results of Examples 1 to 9 and Comparative Example 1 are summarized in Table 1.

[Table] Test Example 1 The polyimide compound obtained in Example 1 was
It was redissolved in DMAc to a concentration of 10% by weight and spin coated onto a glass plate. When the film was peeled off after drying at 80°C for 1 hour, no shrinkage due to drying was observed and it could be easily peeled off. This film was vacuum dried at 100° C. overnight and then subjected to a tensile test according to JISK6911. The results are shown in Table 2. Test Example 2 Using the polyimide compound obtained in Example 9,
A tensile test was conducted in the same manner as Test Example 1. The results are shown in Table 2.

【table】 [Brief explanation of the drawing]

FIG. 1 and FIG. 2 are diagrams showing infrared absorption spectra of polyimide compounds and polyamic acid obtained in Examples of the present invention, respectively.

Claims (1)

[Claims] 1 A soluble polyimide compound characterized by subjecting polyamic acid obtained from 2,3,5-tricarboxycyclopentyl acetic acid or its anhydride and a diamine to an imidization reaction in the presence of an organic carboxylic acid anhydride in an organic solvent solution state. manufacturing method.