JPH0559169A - Polyimide resin - Google Patents

Abstract

(57) [Summary] [Purpose] Resins for paints and various molding materials (films, sheets, etc.) that have excellent heat resistance and are soluble in various solvents.
A polyimide resin useful as the above is provided. [Structure] General formula (I) (In the formula, R represents a tetravalent aromatic group and Ar represents a divalent diphenylnaphthylamine group.) And has an intrinsic viscosity of 0 at 30 ° C. in N-methylpyrrolidone or concentrated sulfuric acid. Polyimide resin of 1 to 5 dl / g.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polyimide resin, and more particularly to a novel polyimide resin which is soluble in various organic solvents and has a high glass transition temperature.

[0002]

2. Description of the Related Art Conventionally, wholly aromatic polyimide resins have excellent heat resistance and excellent mechanical properties, and have been widely used as industrial materials. However, since many of these polyimide resins are insoluble in various organic solvents and mineral acids, and are neither thermally nor infusible, it was extremely difficult to mold them.

[0003]

Most of the conventional aromatic polyimide resins as described above have a high glass transition temperature and excellent heat resistance, and at the same time have good solubility in organic solvents. In addition, the absence of an aromatic polyimide resin having both heat resistance and processability has been a serious problem in commercial use of this resin.

Therefore, an object of the present invention is to provide a novel polyimide resin which is soluble in various organic solvents and has a high glass transition temperature, and a method for producing the same.

[0005]

The present inventors have the following general formula for the purpose of producing a polyimide resin which is soluble in various organic solvents and mineral acids and has a high glass transition point.

[0006]

[Chemical 2]

(Wherein R'is a tetravalent aromatic group and Ar 'is a divalent triphenylamine group) and has an intrinsic viscosity at 30.degree. C. in concentrated sulfuric acid. 0.
A polyimide resin of 1 to 5 dl / g is proposed (Japanese Patent Application No. 2-113707). However, the above-mentioned invention was not always sufficient in the effect of improving the solubility in an organic solvent.

The inventors of the present invention completed the present invention by making diligent efforts to produce a polyimide resin having excellent solubility in various organic solvents and mineral acids and having a high glass transition point. That is, the gist of the present invention resides in the general formula (I)

[0009]

[Chemical 3]

(In the formula, R represents a tetravalent aromatic group and Ar represents a divalent diphenylnaphthylamine group.), Which is unique to N-methylpyrrolidone or concentrated sulfuric acid at 30 ° C. It exists in a polyimide resin having a viscosity of 0.1 to 5 dl / g.

The polyimide resin of the present invention is a diphenylnaphthylamine (II) represented by the following general formula (II).
And tetracarboxylic dianhydride (III) represented by the following general formula (III).

[0012]

[Chemical 4]

(Ny represents a naphthyl group which may have a substituent.)

[0014]

[Chemical 5]

(R is the same as above) In formula (III), R specifically includes the following tetravalent aromatic organic groups.

[0016]

[Chemical 6]

The tetracarboxylic acid dianhydride represented by the above general formula (III) includes pyromellitic dianhydride, 3,
4,3 ', 4'-biphenyltetracarboxylic dianhydride, 3,4,3', 4'-diphenyl ether tetracarboxylic dianhydride, 3,4,3 ', 4'-benzophenone tetracarboxylic dianhydride , 3,4,3 ', 4'-diphenylsulfone tetracarboxylic acid dianhydride, 2,2-
Bis (3,4-dicarboxyphenyl) -1,1,1,
3,3,3-hexafluoropropane dianhydride, 3,
The tetracarboxylic dianhydride such as 4,3 ″, 4 ″ -terphenyltetracarboxylic dianhydride can be exemplified.

An example of the first method for producing the polyimide resin of the present invention will be described. By reacting a diamine compound and a tetracarboxylic dianhydride in an organic solvent at -20 to 50 ° C for several minutes to several days. , A polyamic acid is obtained, and then a polyimide resin is obtained by heating or treatment with a dehydration ring-closing agent. Examples of the organic solvent that can be used in the polyamic acid synthesis reaction include amide solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone, and aromatic compounds such as benzene, anisole, diphenyl ether, nitrobenzene, benzonitrile, and pyridine. Examples include system solvents, halogen-based solvents such as chloroform, dichloromethane, 1,2-dichloroethane and 1,1,2,2-tetrachloroethane, ether-based solvents such as tetrahydrofuran, dioxane and diglyme. In particular, when an amide-based solvent such as N, N-dimethylacetamide or N-methyl-2-pyrrolidone is used, a highly polymerized polyamic acid can be obtained.

Then, the obtained polyamic acid is added to 200-
Heat at 350 ° C. to obtain a polyimide resin. Further, the polyimide resin can be obtained by treating the polyamic acid with a cyclodehydrating agent such as a mixed solution of acetic anhydride and pyridine. In this method, the molecular weight of the polyimide resin of the present invention is limited by the charging ratio of the tetracarboxylic dianhydride and the diamine compound, and a high molecular weight polyimide resin can be produced when used in equimolar amounts.

As an example of the second method for producing the polyimide resin of the present invention, a polyimide is obtained by reacting a diamine compound and a tetracarboxylic acid dithio anhydride in an organic solvent at 20 to 200 ° C. for several minutes to several days. The resin is obtained. Organic solvents that can be used in the synthesis reaction of this polyimide include amide solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone, aromatic compounds such as benzene, anisole, diphenyl ether, nitrobenzene, benzonitrile and pyridine. System solvent, chloroform, dichloromethane, 1,2-dichloroethane, 1,
Examples thereof include halogen-based solvents such as 1,2,2-tetrachloroethane, ether-based solvents such as tetrahydrofuran, dioxane, and diglyme. Especially N,
When an amide-based solvent such as N-dimethylacetamide or N-methyl-2-pyrrolidone is used, a high polymer polyimide can be obtained.

In this method, the molecular weight of the polyimide resin of the present invention is limited by the charging ratio of the tetracarboxylic dianhydride and the diamine compound, and a high molecular weight polyimide resin can be produced when used in equimolar amounts. ..
The polyimide resin of the present invention has an intrinsic viscosity of 0.1 to 5 dl / g measured in N-methylpyrrolidone or concentrated sulfuric acid. This is based in principle on values measured in N-methylpyrrolidone, but depending on the degree of solubility concentrated sulfuric acid can be used.

The reason why the intrinsic viscosity of the polyimide resin of the present invention is limited to 0.1 to 5 dl / g is that when the intrinsic viscosity is less than 0.1 dl / g, the mechanical properties and heat resistance of a molded article formed into a film or the like are reduced. If the intrinsic viscosity exceeds 5 dl / g, the solubility in organic solvents and the like will be poor. The polyimide resin of the present invention thus produced is soluble in mineral acids such as sulfuric acid. Further, the solubility thereof is changed depending on the manufacturing method used and the type of the tetracarboxylic dianhydride derivative represented by the general formula (III), but in some resins, N-methyl-2-
It becomes soluble in all or part of solvents such as pyrrolidone (NMP), dimethylacetamide, dimethylsulfoxide, metacresol, dimethylformamide, pyridine, chloroform and tetrahydrofuran. Further, the polyimide resin of the present invention has a high glass transition point of 300 ° C. or higher, is thermally stable, and no thermal decomposition is observed even when heated to around 500 ° C.

[0023]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. Reference Example 1 4,4'-Dinitrodiphenylnaphthylamine compound
Forming 4,4'-dinitro diphenyl naphthyl amine, 1-
It was synthesized from naphthylamine and p-fluoronitrobenzene.

50 equipped with a stirrer, a cooling pipe, and a nitrogen introducing pipe
17.9 g of 1-naphthylamine in a 0 ml eggplant flask
(125 mmol), dimethyl sulfoxide (DMS
O) 300 ml, p-fluoronitrobenzene 26.5
ml (250 mmol), sodium hydride 6.0 g
(250 mmol) were added in order, and under a nitrogen atmosphere, 100
The reaction was carried out at 0 ° C for 6 hours. The reaction solution was poured into saturated saline to precipitate dinitrodiphenylnaphthylamine. The precipitated dinitro body was filtered, dried under reduced pressure, and recrystallized with acetic acid to obtain yellow crystals. Yield = 32.44 g (67.38%) m.p. p. = 176-178 ° C. IR (KBr): 1581,1343 cm ⁻¹ (N
O ₂ ) Elemental analysis [C ₂₂ H ₁₅ N ₃ O ₄ ] Carbon Hydrogen Nitrogen Calculated value (%) 68.57 3.92 10.90 Measured value (%) 68.27 3.71 10.90

4,4′-diaminodiphenylnaphthyl
Synthesis of luamine 4,4'-diaminodiphenylnaphthylamine is 4,
It was synthesized by reducing 4'-dinitrodiphenylnaphthylamine with stannic chloride. In a 1-liter eggplant flask, 15.40 g (40 mmol) of 4,4′-dinitrodiphenylnaphthylamine and 200 parts of ethanol were added.
ml was added and dissolved. In advance, 35% hydrochloric acid 120
99.60 g (440 mmo) of stannic chloride dissolved in ml
l) was added to this mixture and 8 at 100 ° C. under nitrogen atmosphere.
Reflux for hours. After the reaction, the temperature was cooled to room temperature, the oil bath was changed to an ice bath, 540 ml of 40% sodium hydroxide aqueous solution was added little by little, and the mixture was further stirred for 8 hours. The reaction solution was poured into cold water and stirred for 30 minutes, then the yellow-green precipitate was filtered, washed with distilled water until the precipitate became neutral, and dried under reduced pressure. The obtained yellow-green powder was purified by vacuum distillation to obtain a yellow solid.

Yield = 4.16 g (32.0%) m.p. p. = 167-169 ° C IR (KBr): 3354, 3040 cm ^-1 (N
H ₂ ) ¹ H-NMR: 3.3 ppm (NH ₂ ) Elemental analysis [C ₂₂ H ₁₉ N ₃ ] Carbon hydrogen Nitrogen Calculated value (%) 81.20 5.88 12.91 Measured value (%) 79.93 5.79 12.81 The infrared absorption (IR) spectrum was measured with a Shimadzu Fourier transform infrared spectrophotometer FT / IR-8100M. Nuclear magnetic resonance (NMR) spectra are available from JEOL J
It was measured by NM-FX900 FT-NMR spectrum. The melting point was measured by a precision trace melting point measuring instrument (Ishii Shoten Co., Ltd.).

Example 1 2.5 mmol (0.813) of diaminodiphenylnaphthylamine obtained in Reference Example while passing nitrogen through a 100 ml three-necked flask equipped with a stirrer and equipped with a nitrogen inlet tube.
g), and 6 ml of dimethylacetamide (DMAc)
Was added and dissolved. Add 2.5 parts of pyromellitic anhydride to this solution.
mmol (0.545 g) was added, the acid anhydride on the wall of the flask was washed off with 4 ml of DMAc, and the room temperature (15-
The mixture was stirred at 20 ° C) for 6 hours. The viscous polymerization solution was cast on a glass plate, and the pressure was reduced to 12 at 80 ° C and 30 mmHg vacuum.
Dried for hours.

This polyamic acid film was treated at 100 ° C.
A polyimide film was obtained by drying under reduced pressure at 200 ° C. and 300 ° C. for 1 hour. From the infrared absorption (IR) spectrum of polyimide, 1770,1
Absorption of imide bond was observed at 721, 1377, 721 cm ^-1 .

Example 2 The same as Example 1 except that the aromatic tetracarboxylic dianhydrides shown in b to f of Table 1 were used in place of pyromellitic anhydride (a in Table 1) in Example 1. The operation was performed to obtain a polyamic acid and a polyimide.

Table 2 shows the intrinsic viscosity (ηinh) of polyimide and the results of elemental analysis. Table 3 shows the solubility of the obtained polyimide in various solvents. In Table 3, the content in parentheses is an aromatic polyimide having a triphenylamine structure (a structural unit represented by the following structural formula (V)) of Japanese Patent Application No. 2-113707. The solubility of the polyimide having a diphenylnaphthylamine structure (a structural unit represented by the following structural formula (IV)) is improved in any of the solvents.

[0031]

[Chemical 7]

The mechanical properties (tensile test results) of the polyimide having a diphenylnaphthylamine structure, the 10% weight loss temperature (T ₁₀ ) and the glass transition temperature T _g (by the dynamic viscoelasticity measuring method) measured by a thermogravimetric analyzer were measured. The results are shown in Table 4. In addition, tensile test (tensile strength, elongation at break, tensile modulus)
Was performed according to JIS-K-7113.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

[Table 4]

[0037]

INDUSTRIAL APPLICABILITY The polyimide resin obtained by the present invention has excellent heat resistance and is soluble in various solvents, and is therefore useful as a coating resin and various molding materials (films, sheets, etc.).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mina Ishida 537-1 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Juichi Kurosaki 1-2-6-12 Fujimoto, Kokubunji-shi, Tokyo

Claims (1)

[Claims] 1. A compound represented by the general formula (I): (In the formula, R represents a tetravalent aromatic group and Ar represents a divalent diphenylnaphthylamine group.) And has an intrinsic viscosity of 0 at 30 ° C. in N-methylpyrrolidone or concentrated sulfuric acid. Polyimide resin of 1 to 5 dl / g.