JPH0532779A - Polyimide resin having naphthalene skeleton - Google Patents

Abstract

PURPOSE:To obtain the subject new resin, having ultrahigh heat resistance and excellent in dimensional stability, mechanical strength and electrical characteristics by introducing a naphthalenetetracarboxylic acid part into the basic skeleton of a polyimide. CONSTITUTION:A polyimide resin expressed by the formula (X is carbon atom- containing organic group). The aforementioned resin is obtained by reacting 2,3,6,7-naphthalenetetracarboxylic dianhydride with a diamine such as hexamethylenediamine, e.g. the acid anhydride with the diamine in a solvent such as N-methyl-2-pyrrolidone, providing a polyamic acid, then forming the prepared polyamic acid into a film, etc., subsequently polycondensing the polyamic acid according to a method for heating the formed film, etc., and forming imide bonds.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polyimide resin having high heat resistance which can be used under severe conditions, excellent dimensional stability and mechanical properties.

[0002]

2. Description of the Related Art Generally, a polyimide resin has extremely high heat resistance and excellent mechanical strength not found in polyolefin resins such as polyethylene resin and polypropylene resin, and therefore, as an organic material, it is a material under severe conditions at high temperatures. Also, it is widely used as a material for lightweight and precise parts in the electronics field, such as flexible printed circuit board materials, liquid crystal alignment films, high temperature adhesives, molding materials, etc., and has become an indispensable material for modern society. ..

Conventionally, such polyimide resins include dianhydrides such as pyromellitic acid, 3,3 ', 4,4'-biphenyltetracarboxylic acid and 3,3', 4,4'-benzophenonetetracarboxylic acid. Various polyimide resins made from materials are manufactured and put into practical use.

[0004]

The above-mentioned various polyimide resins have high heat resistance and excellent mechanical strength, so that their applications are expanding more and more as substitutes for metals in the fields requiring lightweight and precise processing. ing.

However, as a material that can replace these metals, a resin is required that exhibits superior properties such as heat resistance and dimensional stability to the existing ones.

The present invention has been made in view of the above requirements, and an object thereof is to provide a polyimide resin having more excellent heat resistance and mechanical strength.

[0007]

[Means for Solving the Problems] Conventionally developed polyimide resins are generally pyromellitic dianhydride, 3,
3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3',
It is obtained by reacting a tetracarboxylic dianhydride such as 4,4′-benzophenone tetracarboxylic dianhydride with an aromatic diamine.

However, since 2,3,6,7-naphthalenetetracarboxylic acid cannot be synthesized in a large amount because it is extremely difficult to synthesize, 2,3,6,7-naphthalenetetracarboxylic acid is used as a raw material. The polyimide has not been reported yet.

The present inventors have developed an efficient method for synthesizing 2,3,6,7-naphthalenetetracarboxylic acid and its dianhydride, which have naphthalene as a basic skeleton as a tetracarboxylic acid moiety, We have already applied for a patent (JP-A-2-
69433, Japanese Patent Laid-Open No. 2-69434). Then, by introducing a naphthalenetetracarboxylic acid moiety into the basic skeleton of the polyimide, it is possible to increase the symmetry and rigidity as an imide bond, and have extremely high heat resistance and excellent dimensional stability and mechanical properties. It was found that a novel polyimide can be obtained, and the present invention has been completed.

That is, the polyimide resin having a naphthalene skeleton of the present invention has the general formula

[0011]

[Chemical 2] It is represented by. (In the formula, X represents an organic group containing at least one carbon atom.)

This polyimide resin is obtained by polycondensing 2,3,6,7-naphthalenetetracarboxylic dianhydride and diamine.

Any diamine can be used as long as it can undergo a condensation reaction with the above acid anhydride. This diamine may be any of fatty acid diamine, aromatic diamine and the like. The aliphatic diamine has, for example, 2 carbon atoms.
It is preferably about 15 to 15, and specific examples thereof include pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, 1,3-diamino-2,2-dimethylpropane and the like. Examples of aromatic diamines include diamino compounds in which one phenyl or about 2 to 10 phenyls are bonded. Specifically, phenylenediamine and its derivatives, diaminodiphenyl compounds and their derivatives, diaminotriphenyl compounds and their derivatives,
Examples include diaminonaphthalene and its derivatives, aminophenylaminoindane and its derivatives, diaminotetraphenyl compounds and their derivatives, diaminohexaphenyl compounds and their derivatives. The phenylenediamine is m-phenylenediamine, p-phenylenediamine and the like, and the phenylenediamine derivative is diamine having an alkyl group such as methyl group and ethyl group bonded thereto, for example, 2,4-tolylenediamine. The diaminodiphenyl compound is a compound in which two aminophenyl groups are bonded to each other via another group. The bond is an ether bond, a sulfonyl bond, a thioether bond, a bond with an alkylene or a derivative thereof, an imino bond, an azo bond, a phosphine oxide bond, an amide bond, a ureylene bond, or the like. The alkylene bond has about 1 to 6 carbon atoms, and the derivative group thereof is one in which one or more hydrogen atoms of the alkylene group are substituted with a halogen atom or the like. Examples of diaminodiphenyl compounds include 3,3'-diaminodiphenyl ether, 4,4'-
Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 4,4'-
Diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3 ' -Diaminodiphenyl ketone, 3,4'-diaminodiphenyl ketone, 2,2-bis (p-aminophenyl) propane, 2,2'-bis (p-aminophenyl) hexafluoropropane, 4-methyl-2,4 -Bis (p-aminophenyl) -1-pentene, 4-methyl-2,4-bis (p-aminophenyl) -2-pentene, iminodianiline, 4-methyl-2,4-bis (p-amino Phenyl)
Pentane, bis (p-aminophenyl) phosphine oxide, 4,4′-diaminoazobenzene, 4,4′-diaminodiphenylurea, 4,4′-diaminodiphenylamide and the like can be mentioned. The diaminotriphenyl compound is a compound in which two aminophenyl groups and one phenylene group are both bonded via another group, and the other groups are the same as those of the diaminodiphenyl compound. Examples of diaminotriphenyl compounds include 1,3-bis (m-aminophenoxy) benzene, 1,3-bis (p-aminophenoxy) benzene, and 1,4-bis (p-aminophenoxy) benzene. be able to. Examples of diaminonaphthalene include:
Mention may be made of 1,5-diaminonaphthalene and 2,6-diaminonaphthalene. Examples of aminophenylaminoindan include 5 or 6-amino-1- (p-aminophenyl)-
Mention may be made of 1,3,3-trimethylindane. Examples of diaminotetraphenyl compounds include 4,4'-bis (p
-Aminophenoxy) biphenyl, 2,2-bis [p- (p'-aminophenoxy) phenyl] propane and 4,4'-bis (p
-Aminophenoxy) diphenyl sulfone can be mentioned. Examples of diaminohexaphenyl compounds include 2,2-bis [p- (p'-aminophenoxy) biphenyl]
Examples thereof include propane and 2,2′-bis [p- (m-aminophenoxy) phenyl] benzophenone. In addition,
A compound in which the hydrogen atom of these aromatic diamines is replaced by at least one substituent selected from the group consisting of chlorine atom, fluorine atom, bromine atom, methyl group, methoxy group, cyano group, phenyl group and the like. Good.

As a method for synthesizing a polyimide, the following method known in the prior art can be applied. A method of reacting an acid anhydride and a diamine in a solvent to form a polyamic acid and then forming a film, etc., and then forming an imide bond by heating. An acid anhydride and a diisocyanate are reacted in an organic solvent to directly form a polyimide bond. Method for forming Method for reacting acid anhydride and diamine under heating to directly form polyimide bond

In the synthesis of polyimide, it is preferable that the ratio of 2,3,6,7-naphthalenetetracarboxylic dianhydride and diamine is 1: 1, but some components are contained in a slight excess. It may be the one.

As the solvent used for synthesizing the polyimide, any solvent which can dissolve 2,3,6,7-naphthalenetetracarboxylic dianhydride and the above diamine can be used. N-methyl-2-pyrrolidone, N, N-dimethylformamide, dimethylsulfoxide, N, N-dimethylacetamide, N-methyl-ε-caprolactam, γ-butyrolactone, tetrahydrothiophene-1,1-dioxide, N , N, N ', N'-tetramethylurea and hexamethylphosphoramide can be mentioned. A suitable concentration is about 1 to 60% by weight, preferably 5 to 30% by weight, particularly preferably 10 to 20% by weight, based on the total weight of acid anhydride and diamine.

The reaction conditions are particularly preferably a reaction time of 10 minutes to 20 hours and a reaction temperature of -10 to 50 ° C.

The polyamic acid produced under the above conditions is preferably one having a molecular weight having a sufficient viscosity for molding into a film or the like. As for those obtained by sufficiently reacting 2,3,6,7-naphthalenetetracarboxylic acid and diamine in a solvent, there is a preferable viscosity for use in film formation depending on the diamine used, but generally a polyamic acid solution. The logarithmic viscosity of is about 0.3 to 5.0, preferably about 0.5 to 3.0.

The resulting polyamic acid is cast in the case of a film, and in the case of a powder, the polymer is precipitated by vigorous stirring while adding a poor solvent or a non-solvent, and solid-liquid separation is performed. Water can be mentioned as an example of the non-solvent. These are heated to promote solidification and drying. It is preferable to heat the solvent gently while reducing the pressure until the solvent is dried, and then to 200 ° C or higher, preferably about 250 to 350 ° C.

In the case of a film, the polyimide resin of the present invention may be used as a product as it is, and in the case of a powder, it may be formed into a desired shape by compression molding if necessary.

[0021]

EXAMPLES The measuring methods and devices used in this example and comparative examples are as follows. Tensile test: JIS C-2318 Thermobalance: TG / DTA-200 (Seiko Denshi SSC-5000 series) 10 ℃ / min, 50 to 1000 ℃, N ₂ atmosphere Linear expansion coefficient: TMA-120 (Seiko Denshi SSC-5000 series) ) 5 ℃ / min, 25-400 ℃, N ₂ atmosphere Infrared absorption spectrum: FT-IR Biorat FTS-20 / 90; KBr method Nuclear magnetic resonance spectrum ( _13C ): JNM-G × 270WB (JEOL) Solid NMR with film or powder Electrical characteristics (dielectric breakdown voltage, volume resistivity, dielectric constant, dielectric loss tangent): JIS C-6471 Logarithmic viscosity: 35 ° C, 0.5g / dl (solvent used for reaction) Capillary viscometer Logarithm Viscosity ηinh = 1 / c × ln t / to

Example 1 and Comparative Example 1 Preparation of polyamic acid; capacity with nitrogen gas introduction tube, calcium chloride tube, thermometer, and rotary torque meter was 2 liters.
In a separable flask of 60,07 g (0.3 mol) of 4,4'-diaminodiphenyl ether and 80.45 g (0.3 mol) of 2,3,6,7-naphthalenetetracarboxylic acid dianhydride were added, and the total amount of these was 15 wt. % Of N-methyl-2-pyrrolidone (NMP) 796 g was added. Then, while observing the torque of the rotary torque meter, the mixture was stirred at room temperature under a nitrogen stream to obtain an NMP solution of polyamic acid. The reaction time was about 7 hours. During the polymerization, a small amount of NMP was added to make the final polyamic acid solution concentration 14 wt%. The logarithmic viscosity at this time was ηinh = 1.45.

Preparation of polyimide film: The polyamic acid solution obtained above was cast on a glass plate,
Drying was performed at 1 ° C for 1 hour, 200 ° C for 1 hour, and 300 ° C for 10 minutes.
Next, it was peeled off from the glass plate, fixed on a support frame, and heated at 300 ° C. for 1 hour to obtain a polyimide film. The thickness of the film was about 50μ. The infrared spectrum of the film is shown in FIG. 1 and the ₁₃ C-NMR is shown in FIG. The results of elemental analysis are shown in the table below.

[0024]

[Table 1]

Preparation of Comparative Film: For comparison, a polyamic acid was prepared by the following procedure using pyromellitic dianhydride and 4,4′-diaminodiphenyl ether in the same reactor as in Example 1. , Made a film.

105.56 g (0.4840 m) of pyromellitic dianhydride
ol) and 4,4'-diaminodiphenyl ether 97.40 g (0.4
(846 mol) was made to have a concentration of 15 wt% of N-methyl-2-pyrrolidone, and stirred at room temperature for 6 hours for polymerization to prepare a polyamic acid solution. NMP was added during the polymerization so that the final concentration of polyamic acid was 14 wt%. The logarithmic viscosity of this solution was ηinh = 2.10. A film having a thickness of about 50 μm was prepared from the polyamic acid solution prepared here by the same operation as described in Example 1. Of film
₁₃ C-NMR is shown in FIG.

Physical Properties of Polyimide Film: Polyimide film (N-film) of one embodiment of the present invention using 2,3,6,7-naphthalenetetracarboxylic dianhydride as raw material and pyromellitic acid as Comparative Example 1. A polyimide film (p-film) made from dianhydride was made under the same conditions, and its mechanical, thermal, and electrical properties were measured and compared. The results are shown in Table 2.

[0028]

[Table 2]

Examples 2 to 4 The reaction was carried out using a 500 ml flask equipped with a stirring blade, a raw material addition port, a nitrogen introduction tube and a calcium chloride tube. 40
N, N-Dimethylacetamide and diamine were placed in a flask, which was immersed in a water bath at -60 ° C and purged with nitrogen, at the ratios shown in Table 3, and further 2,3,6,7-naphthalenetetracarboxylic acid (NT
C) 10.00 g of dianhydride was added and reacted for 6 hours with vigorous stirring.

After completion of the reaction, N, N-dimethylacetamide was further added to obtain a 10 wt% solution. The logarithmic viscosity of the polyamic acid of Example 2 measured at 35 ° C. was 0.46. To this, a solution of N, N-dimethylacetamide: water = 1: 3 was added with stirring to precipitate a polymer, which was filtered and dried, and further heat treated at 200 ° C, 60 minutes, 300 ° C, 60 minutes. To obtain a polyimide powder.

[0031]

[Table 3]

The measurement results of the infrared absorption spectra of the polyimide powders of Examples 2 and 4 obtained as described above are shown in FIG.
5 and Table 4. Absorption was observed at around 1700 cm ^-1 and 1770 cm where the characteristic absorption of the 5-membered ring imide group was observed. Further, ₁₃ C-NMR of the polyimide powder of Example 2 is shown in FIG. 6, respectively.

[0033]

[Table 4]

Table 5 shows the measurement results of the thermobalances of Examples 2-4. Measuring conditions Measuring range: Room temperature to 1000 ° C Temperature rising rate: 10 ° C / min Atmosphere: N ₂ 100 ml / min

[0035]

[Table 5]

Examples 5 to 7 The reaction was carried out using a 200 ml flask equipped with a stirring blade, a raw material addition port, a nitrogen introduction tube and a calcium chloride tube. 0
C. to 30.degree. C. Immersed in a water bath and replaced with nitrogen in a flask.
The N, N-dimethylacetamide and the diamine shown in (1) were added, and further NTC dianhydride (10.00 g) was added, and the mixture was reacted for 6 hours with vigorous stirring to obtain a polyamic acid solution. The logarithmic viscosities of this solution measured at 35 ° C. were 2.08 for Example 5, 2.29 for Example 6 and 1.82 for Example 7.

This polyamic acid solution was cast on a glass plate of 30 cm × 40 cm, the solvent was removed by a vacuum drier, and the solution was added to 50
Heat treatment was carried out at ℃, 30 minutes, 200 ℃, 60 minutes, 300 ℃, 60 minutes to obtain a polyimide film.

[0038]

[Table 6]

The measurement results of the infrared absorption spectra of the polyimide films of Examples 5 to 7 obtained as described above are shown in FIGS. 7 to 9 and Table 7. Each 1700 cm ^-1 and 1770 cm ^-1
Characteristic absorption of a 5-membered ring imide group was observed in the vicinity.

[0040]

[Table 7]

Table 8 shows the measurement results and mechanical properties (tensile test) of the thermobalances of Examples 5-7.

[0042]

[Table 8]

Examples 8 to 11 and Comparative Examples 2 to 3 The reaction was carried out using a 200 ml separable flask equipped with a stirring blade, a raw material addition port, a nitrogen introduction tube and a calcium chloride tube. . 10.00 g of acid anhydride (NTC acid dianhydride or pyromellitic acid dianhydride) was added to a flask which was immersed in a water bath at 0 to 40 ° C and purged with nitrogen, and N, N-dimethylacetamide at the ratio shown in Table 10 below And diamine were added and reacted for 6 hours with vigorous stirring to obtain a polyamic acid solution.

The logarithmic viscosity (0.5 g / dl, 35 ° C.) of the polyamic acids of Examples 8 to 11 obtained as described above is shown in the table below.

[0045]

[Table 9]

This shows that the reaction has proceeded sufficiently.

This polyamic acid solution was cast on a glass plate of 30 cm × 40 cm, the solvent was removed by a vacuum dryer, and the mixture was dried at 150 ° C.
Heat treatment was performed for 20 minutes at 200 ° C, 60 minutes, 300 ° C, and after peeling from the glass, it was fixed on a support frame and heat treated at 300 ° C for 60 minutes to obtain a polyimide film.

[0048]

[Table 10]

Properties of Polyimide Film: Mechanical, thermal and electrical properties of the polyimide films of Examples 8 to 11 and Comparative Examples 2 to 3 obtained as described above were measured and compared. The results are shown in Tables 11-13.

[0050]

[Table 11]

[0051]

[Table 12]

[0052]

[Table 13]

Next, the measurement results of infrared absorption spectra of the polyimide films of Examples 8 to 11 are shown in FIGS. Each characteristic absorption of 5-membered ring imide group near 1700 cm ^-1 and 1770 cm ^-1 were observed.

[0054]

[Table 14]

The results of elemental analysis of the polyimide film of Example 9 are shown in the table below.

[0056]

[Table 15]

₁₃ C--N of the polyimide film of Example 9
MR is shown in FIG. Results of solid state NMR analysis of the polymer;
(Figs. 2, 3, 6, 14) Around 0 to 80 PPM, a peak of carbon due to an aliphatic hydrocarbon (Example 2) Around 100 to 160 PPM, and a peak of around 170 PPM of a carbon due to an aromatic hydrocarbon, Carbon peaks due to carbonyl groups are detected.

[0058]

As described above, the polyimide resin having a naphthalene skeleton of the present invention can be prepared by introducing a naphthalene tetracarboxylic acid moiety into the basic skeleton of the polyimide.
The symmetry and rigidity as an imide bond can be increased, and it has extremely high heat resistance and excellent dimensional stability, mechanical strength and electrical characteristics.

[Brief description of drawings]

FIG. 1 is a diagram showing an infrared spectrum of a polyimide film of Example 1 of the present invention.

FIG. 2 ₁₃ C of the polyimide film of Example 1 of the present invention
-A diagram showing an NMR spectrum.

FIG. 3 ₁₃ C of the polyimide film of Comparative Example 1 of the present invention
-A diagram showing an NMR spectrum.

FIG. 4 is a diagram showing an infrared spectrum of a polyimide powder of Example 2 of the present invention.

FIG. 5 is a diagram showing an infrared spectrum of a polyimide powder of Example 4 of the present invention.

FIG. 6 ₁₃ C—N of polyimide powder of Example 2 of the present invention
It is a figure which shows MR spectrum.

FIG. 7 is a diagram showing an infrared spectrum of a polyimide film of Example 5 of the present invention.

FIG. 8 is a diagram showing an infrared spectrum of a polyimide film of Example 6 of the present invention.

FIG. 9 is a diagram showing an infrared spectrum of a polyimide film of Example 7 of the present invention.

FIG. 10 is a diagram showing an infrared spectrum of a polyimide film of Example 8 of the present invention.

FIG. 11 is a diagram showing an infrared spectrum of the polyimide film of Example 9 of the present invention.

FIG. 12 is a diagram showing an infrared spectrum of a polyimide film of Example 10 of the present invention.

FIG. 13 is a view showing an infrared spectrum of the polyimide film of Example 11 of the present invention.

FIG. 14 is ₁₃ C of the polyimide film of Example 9 of the present invention.
-A diagram showing an NMR spectrum.

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[Procedure amendment]

[Submission date] January 8, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Fig. 2]

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[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

[Figure 7]

[Figure 8]

[Figure 9]

[Figure 10]

FIG. 11

[Fig. 12]

[Fig. 13]

FIG. 14

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoko Yamamoto 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Kazuhiko Tate 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Date Inside the Steel Tube Co., Ltd. (72) Inventor Masami Ono 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Steel Tube Co., Ltd.

Claims (1)

What is claimed is: 1. A general formula: (In the formula, X represents an organic group containing at least one or more carbon atoms.)