JP2002212287A - Manufacturing method of polyimide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a polyimide advantageous for modifying the polyimide and permitting shortening of the manufacturing process. SOLUTION: At least one acid dianhydride and at least one diamine are subjected to heating once in the presence of an acid catalyst and pyridine in an organic polar solvent to directly give a polyimide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyimide, and more particularly to a method for producing a polyimide, which is advantageous for reforming and can shorten the production process.

[0002]

2. Description of the Related Art Polyimide is widely used in the field of electric and electronic industries as a heat-resistant resin having excellent mechanical properties, electrical properties, chemical resistance, weather resistance and the like. Polyimide has poor solvent solubility and cannot be obtained as a polyimide resin solution for casting or impregnation. For this reason, a polyimide solution is obtained by dissolving a polyamic acid, which is a polyimide precursor, having excellent solvent solubility in an organic polar solvent, forming a resin solution. ("New heat-resistant resin", page 216, Lee, Sto
II, Nevils, Tokyo Chemical Dojin).

However, since the polyimide is produced by a two-step method via a polyamic acid, the production process of the polyimide is long and the cost is high.

Therefore, as a conventional method for producing a polyimide in which the production process of the polyimide is shortened, there is a method disclosed in Japanese Patent Application Laid-Open No. 7-157560, for example.

In this method, an acid dianhydride and an aromatic diamine are heated in an organic polar solvent in the presence of an acid catalyst to form an imide oligomer, and then an acid dianhydride and / or an aromatic diamine are further added. Is added and heated to produce a polyimide block copolymer. Thereby, the production process of the polyimide can be shortened, and the cost can be reduced.

[0006]

However, according to the conventional method for producing a polyimide block copolymer, it is necessary to perform two heating steps, so that there is a problem that much time is required for the production. Although the block copolymer exhibits excellent properties of each component, it is disadvantageous for modification as compared with a polymer or a random copolymer in which the average properties of each component appear.

Accordingly, it is an object of the present invention to be advantageous for reforming,
An object of the present invention is to provide a method for producing polyimide, which can shorten the production process.

[0008]

According to the present invention, in order to achieve the above object, one or more acid dianhydrides and one or more diamines are reacted in an organic polar solvent in the presence of an acid catalyst and pyridine. Provided is a method for producing a polyimide, wherein the polyimide is directly produced by one heating.

When an acid catalyst is added to an organic polar solvent, 1
The polycondensation reaction between at least one kind of acid dianhydride and at least one kind of diamine is accelerated, and a single heating operation gives a polyimide random copolymer. When one kind of acid dianhydride is reacted with one kind of diamine, a simple polymer is obtained. According to this method, the steps can be shortened, and a polyimide solution composition having excellent functionality can be produced by short-time synthesis.

As the organic polar solvent, for example, N, N-
Dimethylformamide (hereinafter referred to as "DMF");
N, N-dimethylacetamide (hereinafter referred to as "DMAc"), dimethylsulfoxide (hereinafter referred to as "DMSD"), N-methyl-2-pyrrolidone (hereinafter referred to as "NMP")
), Ethylene glycol dimethyl ether, sulfolane, tetramethyl urea and the like. D
MF (boiling point: 153 ° C.) is used in a closed system because of its high toxicity. NMP (boiling point 204 ° C.) is a preferred solvent with low toxicity.

As the acid catalyst, for example, phosphoric acid, pyridine hydrochloride, toluenesulfonic acid, benzoic acid, crotonic acid, γ-butyrolactone, cinnamic acid and the like can be used. The amount of the acid catalyst used is 1/4 to the acid dianhydride.
1/200 mol, preferably 1/4 to 1/100 mol. Basic compounds such as pyridine and quinoline also play an auxiliary role in the imidization reaction. Since water is generated along with the polycondensation reaction, toluene, xylene, tetralin and the like are added and water is removed from the system by azeotropic distillation, whereby the imidization reaction is promoted and a high-molecular-weight polyimide resin is obtained.
Reaction temperature is 120 ° C. or higher, preferably 140 to 180 ° C.
It is. The higher the reaction temperature is, the shorter the time required for the condensation is. However, if the temperature is high, the side reaction is generated with the decomposition of the solvent and the diamine. The polycondensation is performed in an atmosphere of an inert gas such as nitrogen, argon, and helium.

The acid dianhydride is not particularly restricted but includes biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, bis (-dicarboxyphenyl) propane dianhydride, 4,4 '-[2 , 2,2
-Trifluoro-1- (trifluoromethyl) ethylidene] bis (1,2-benzenedicarboxylic anhydride) (6
FDA), bis (dicarboxyphenyl) sulfone dianhydride, bis (dicarboxyphenyl) ether dianhydride, thiophenetetracarboxylic dianhydride, pyromellitic dianhydride, naphthalenetetracarboxylic dianhydride, etc. Group dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, bicyclo (2,2,2) -oct-7-
Ene-2,3,5,6-tetracarboxylic dianhydride, 5
(2,5-dioxotetrahydrofuryl) 3-methyl-
Aliphatic acid dianhydrides such as 3-cyclohexene-1,2-dicarboxylic anhydride can be used. These can be used alone or as a mixture of two or more to form a polyimide composition.

[0013] The diamine is not particularly limited,
1,4-benzenediamine, 1,3-benzenediamine, 6-methyl-1,3-benzenediamine, 4,4 ′
-Diamino-3,3'-dimethyl-1,1'-biphenyl, 4,4'-amino-3,3'-dimethoxy-1,
1'-biphenyl, 4,4'-methylenebis (benzeneamine), 4,4'-oxybis (benzeneamine),
3,4'-oxybis (benzeneamine), 3,3'-
Carbokinyl (benzeneamine), 4,4'-thiobis (benzeneamine), 4,4'-sulfonyl (benzeneamine), 3,3'-sulfonyl (benzeneamine),
1-methylethylidine-4,4'-bis (benzeneamine), 1-trifluoromethyl-2,2,2-trifluoroethylidine-4,4'-bis (benzeneamine),
4,4-diaminobenzanilide, 3,5-diaminobenzoic acid, 2,6-diaminopyridine, 4,4′-diamino-3,3 ′, 5,5′-tetramethylbiphenyl,
2,2-bis {4- (4-aminophenoxy) phenyl} propane, bis {4- (4-aminophenoxy) phenyl} sulfone, bis {4- (4-aminophenoxy) phenyl} ethyl, 1,4- Bis (4-aminophenokine) benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4'-diaminobenzanilide,
9,9-bis (4-aminophenyl) fluorene and the like can be mentioned.

[0014]

The present invention will be described below in detail with reference to examples.
However, the present invention is not limited to this. React
Solution of poor polyimide such as methanol or hexane
When added into the sun, polyimide becomes powder or solid
It precipitates and can be recovered quantitatively. Polyimide solution
The liquid composition has viscosity, color tone, specific gravity, concentration, solid content, etc.
Therefore, it can be characterized. This solution composition is cast as it is
Immersion or immersion to evaporate the contained solvent
It can be used as an adhesive, a molded product, and the like. Polyimide solution composition
Was added to excess methanol and precipitated as a solid.
Or cast and cast into various films
Physical properties can be measured. Infrared absorption spectrum
Is measured in the infrared spectrum using the KBr tablet method.
Was. The resulting polyimide is 1780 cm^-1, 1720
cm^-1, 1370cm^-1, 720cm ^-1Polyimi in the vicinity
The characteristic absorption by the metal is recognized. Polyimide precursor
Absorption 165 based on amide bond of polyamic acid
0cm^-1Disappeared 1780cm^-1New absorption
It is. By calculation based on this absorption, almost 100%
It was confirmed that it was turned into a mid-side.

<Example 1> 1000 equipped with a stirrer
A condenser tube with a ball equipped with a trap with a silicone cock was attached to a 3-ml separable flask with a capacity of ml. Bicyclo (2,2,2) oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (hereinafter referred to as “BCD”) 4
9.62 g, 3,3′-dihydroxybenzidine (hereinafter referred to as “HOAB”) 21.62 g, 3,4,3,
4, -biphenyltetracarboxylic dianhydride (hereinafter referred to as "B
"PDA". ) 29.42 g, bis {4- (4-aminophenoxy) benzene} (hereinafter referred to as “m-BAPS”) 21.63 g, and hexamethylenediamine (hereinafter referred to as “HMDA”) 17.43 g, and further γ.
-Valerolactone 1.2 g, pyridine 1.9 g, NMP
558.8 g and 66.2 g of toluene were added, and the mixture was stirred at room temperature in a nitrogen atmosphere for 10 minutes, and then heated to 180 ° C. and stirred for 5 hours.

The number of revolutions was set to 180 rpm, and was appropriately decreased as the reaction decreased. In addition, water generated during the reaction was removed from the silicon cock. Thereafter, vacuum drying was performed to obtain a reaction liquid (varnish).

Next, the resulting varnish is poured into a methanol solution to separate a formed precipitate,
683 g of polyimide was obtained through the steps of pulverization, washing and drying. The infrared absorption spectrum of the obtained polyimide was measured to be 1715 cm ^-1 and 1
Typical imide absorption was observed at 785 cm ^-1 . Gel permeation chromatography (GPC: gel permea
When the weight average molecular weight was measured by using traction chromatography, it was Mw = 148,000.

<Comparative Example 1> 1000 equipped with a stirrer
A condenser tube with a ball equipped with a trap with a silicone cock was attached to a 3-ml separable flask with a capacity of ml. BCD4
9.62 g, and HOAB 21.62 g, and γ-
Valerolactone 1.2 g, pyridine 1.9 g, NMP1
After adding 00 g and toluene 20 g, the mixture was stirred at room temperature in a nitrogen atmosphere for 10 minutes, then heated to 180 ° C., and stirred at 180 rpm for 1 hour.

Next, the reaction solution was air-cooled and BPDA2
9.42 g, m-BAPS 21.63 g and HMDA
17.43 g, further N8.8458.8 g, toluene 4
6.2 g was added, the temperature was raised again to 180 ° C., and the reaction was performed for 5 hours. The number of revolutions was set to 180 rpm, and was appropriately decreased as the reaction decreased. In addition, water generated during the reaction was removed from the silicon cock. After this, vacuum drying is performed,
A reaction liquid (varnish) was obtained.

Next, the resulting varnish is poured into a methanol solution to separate the formed precipitate,
683 g of polyimide was obtained through the steps of pulverization, washing and drying. When the infrared absorption spectrum of the obtained polyimide was measured, typical imide absorption was observed at 1715 cm ^-1 and 1785 cm ^-1 .
The weight average molecular weight was measured using GPC and found to be Mw = 148,000.

Table 1 shows the properties of the polyimides prepared in Example 1 and Comparative Example 1.

[Table 1] The properties of the produced resins were evaluated by the following methods.

[0022] (1) Using the molecular weight measurement Tosoh Corporation TSK ge1 GMH _HR -M type gel column and UV-8020 type detector, a weight average molecular weight, the measurement of number average molecular weight was carried out.

(2) Glass transition point (Tg) Thermomechanical analyzer TMA12 manufactured by Seiko Instruments Inc.
Using a cylindrical quartz probe for the produced film.
g load, temperature rise rate 10 ° C / min, room temperature to 30
Tg measurements up to 0 ° C. were performed.

(3) Thermal expansion coefficient Thermomechanical analyzer TMA12 manufactured by Seiko Denshi Kogyo KK
Using a quartz probe for tension, the film cut into 4 x 20 mm lengths was pulled 5 g at a heating rate of 10 ° C using 0.
/ Min in the temperature range from room temperature to 300 ° C. to determine the thermal expansion coefficient.

(4) Storage elastic modulus The prepared film was cut into a size of 30 × 5 mm, and a dynamic viscoelasticity measuring device DVA-20 manufactured by IT Measurement Control Co., Ltd. was used.
Using 0, the storage elastic modulus was measured from a frequency of 10 Hz, a heating rate of 3 ° C./min, and a measurement range from room temperature to 300 ° C.

(5) Thermal decomposition temperature (T _5% ) Simultaneous differential thermogravimetric measuring device T manufactured by Seiko Denshi Kogyo KK
Using G / DTA320, put 10 mg of the produced resin into a platinum sample pan, and in the air, 100 ml / min.
Thermal analysis was conducted at a flow rate from room temperature to 800 ° C. at a rate of temperature increase of 10 ° C./min, and the temperature at which the weight decreased by _5% (T _5% ) was determined as the thermal decomposition temperature.

(6) Infrared absorption spectrum Using MFT-2000 manufactured by JASCO Corporation, a solder resist applied on a copper foil was measured by a reflection method.

(7) Water absorption rate The produced film is cut into a size of 100 × 100 mm,
The test piece is placed in a dryer at 150 ° C. ± 3 ° C. and dried for 30 minutes. Next, the mixture is cooled to room temperature in a desiccator, placed in a weighing bottle, sealed, and the dry weight (W1) is measured. Next, the test piece is immersed in pure water at 23 ° C. for 24 hours. Thereafter, the test piece is taken out, and the water adhering thereto is quickly wiped off with a bencot within 1 minute, put in a weighing bottle, sealed, and the weight (W2) after water absorption is measured. Calculate the water absorption according to the following equation,
The result was taken with the average of the points. Water absorption = (W2−W1) × 100 / W1

[0029]

As described above, according to the method for producing a polyimide of the present invention, a high molecular weight polyimide is prepared in one step from an acid dianhydride and a diamine by adding an acid catalyst and pyridine to an organic polar solvent. Obtainable. According to this method, the steps can be shortened, and a polyimide solution composition having excellent functionality can be produced by short-time synthesis. Further, since the obtained polyimide is a polymer or a random copolymer, it is advantageous for the modification of the polyimide, and a wide variety of polyimides can be manufactured from a soft elastomer to a hard structural polyimide. For example, a polyimide having properties such as improvement in elastic modulus, improvement in dimensional stability, provision of adhesiveness, improvement in transparency, and improvement in mechanical strength can be obtained. Further, since the polyimide solution composition obtained in the present invention does not contain amic acid, it is stable against heat and moisture and can be stored for a long time.
The form of use itself may be performed in accordance with the conventional method.For example, it can be used as a heat-resistant film, an adhesive, a coating agent, a molding resin and a laminating resin, an electric or electronic material, an aerospace material, Applicable to automotive parts and special equipment parts.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Kamimura 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Within Hitachi Cable Research Institute, Ltd. (72) Inventor Yoshiyuki Ando Hidakacho, Hitachi City, Ibaraki Prefecture 5-1-1, Hitachi Cable, Ltd. Research Institute of Technology (72) Inventor Kenji Asano 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Cable, Ltd. Research Institute of Technology 4J043 PA04 PA08 PA09 PB08 PB15 QB26 QB31 RA34 SA06 TA22 UA082 UA111 UA112 UA121 UA122 UA131 UA132 UA262 XA16 XA19 XB33 XB37

Claims (5)

[Claims] 1. A polyimide is produced by directly heating one or more acid dianhydrides and one or more diamines in an organic polar solvent in the presence of an acid catalyst and pyridine. Production method of polyimide. 2. The method according to claim 1, wherein the acid catalyst is at least one selected from phosphoric acid, toluenesulfonic acid, pyridine hydrochloride, benzoic acid, γ-valerolactone and crotonic acid. A method for producing the polyimide as described above. 3. The organic polar solvent is at least one selected from N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, sulfolane, and tetramethylurea. Item 4. The method for producing a polyimide according to Item 1. 4. The method according to claim 1, wherein the heating is performed at a temperature of 120 ° C. or higher. 5. The method according to claim 1, wherein said heating includes a step of adding at least one selected from toluene, xylene and tetralin to remove water generated by azeotropic distillation out of the system. A method for producing the polyimide as described above.