JPS62241923A - Polyimide - Google Patents

Abstract

PURPOSE:To obtain a polyimide being excellent in both of heat resistance and solvent resistance, having thermoplasticity, melt moldability and good processability and suited for aircraft materials, electronic components, etc., by cyclizing a specified polyamic acid through dehydration. CONSTITUTION:A diamine component comprising 2,2-bis[4-(3-aminophenoxy) phenyl]-1,1,1,3,3,3-hexafluoropropane is reacted with a tetracarboxylic acid dianhydride component comprising pyromellitic anhydride to produce a polyamic acid having repeating units of formula I and a logarithmic viscosity of 0.1-4dl/g as measured in an N,N-dimethylacetamide solvent at a concentration of 0.5g/100ml solvent and 350 deg.C. This polyamic acid is cyclized through dehydration by heating or treating with an imidating agent to obtain the purpose polyimide having repeating units of formula II.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a novel polyimide.

[Conventional technology]

Conventionally, polyimides obtained by the reaction of tetracarboxylic dianhydrides and diamines have various excellent physical properties and good heat resistance, so it is expected that they will continue to be widely used in fields where heat resistance is required. ing.

Many of the polyimides that have been developed so far have excellent properties, but some have excellent heat resistance but poor processability, and resins developed for the purpose of improving processability have poor heat resistance and solvent resistance. There were advantages and disadvantages in performance, including inferior performance.

For example, polyimide (manufactured by DuPont; trade name: Kapton, Vespel) consisting of a basic skeleton represented by formula (III) (I[I) does not have a clear glass transition temperature and is a polyimide with excellent heat resistance. However, it is difficult to process when used as a molding material.
It must be processed using methods such as sintering.

In addition, polyetherimide having a basic skeleton represented by the formula (rV) (IV) (manufactured by General Electric Company; trade name: ULTEM)
) is a resin with excellent processability, but the glass transition temperature is 2.
The resin is as low as 17°C and is soluble in halogenated hydrocarbons such as methylene chloride, making it unsatisfactory in terms of heat resistance and solvent resistance.

[Problem that the invention seeks to solve]

The purpose of the present invention is to have polyimide's inherent excellent heat resistance, good solvent resistance, and excellent processability.
The objective is to obtain a polyimide that can be used for multiple purposes.

[Means for solving problems]

The present inventors conducted intensive studies to achieve the above object and discovered a new polyimide.

That is, the present invention has a repeating unit represented by the formula CI) (■), and its precursor, the formula (
If) The logarithmic viscosity of the polyamic acid having a repeating unit represented by (n) is 0.1 to 4. It is a polyimide with Oa/g.

Here, the logarithmic viscosity is calculated using N,N-dimethylacetamide as the solvent, and 0.5 g of aromatic polyamic acid per 100 mJ.
This is the value measured at 35°C in a solution containing .

The polyimide of the present invention has 2゜2-bis(4-(3-aminophenoxy)phenyl)-1,1 as a diamine component.
, 1,3,3,3-hexafluoropropane is characterized by using pyromellitic anhydride as the tetracarboxylic dianhydride component, and the polyamic acid obtained by polymerizing these is further cyclodehydrated. The polyimide of the present invention is a novel polyimide that has the characteristics of not only the heat resistance of general polyimides but also solvent resistance and thermoplasticity.

By the way, instead of 2.2-bis(4-(3-aminophenoxy)phenyl)-1,1,1,3,3,3-hexafluoropropane, 2, which is the substituted positional isomer of the amino group, , 2-bis(4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, polyimide obtained from anhydride and romellitic acid is a glass at 300°C or higher. It is a resin with a high transition temperature and poor processability, and 2,2-bis( Polyimide obtained from 4-(3-aminophenoxy)phenyl)-1,1,1,3,3,3-hexafluoropropane is a resin with a low glass transition temperature of about 200°C.

That is, the polyimide of the present invention obtained from 2,2-bis(4-(3-aminophenoxy)phenyl)-1,1,1,3,3,3-hexafluoropropane and pyromellitic dianhydride is In addition to its excellent heat resistance and solvent resistance, its thermoplasticity allows for melt molding such as extrusion molding and injection molding, and its good processability makes it suitable as a base material for space and aircraft applications, as well as for electrical and electronic parts. It is an extremely useful polyimide.

The polyimide of the present invention can be obtained by the following method.

That is, first, 2,2-bis(4-(3-aminophenoxy)phenyl)-1,1,1,3,-3,3-hexafluoropropane and pyromellitic anhydride are polymerized in an organic solvent to form a polyamide. Get acid.

This polyamic acid production reaction is usually carried out in an organic solvent. Examples of organic solvents used in this reaction include N,
N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methyl caprolactam, 1,2-dimethoxyethane, bis(
2-methoxyethyl)ether, 1.2-bis(2-methoxyethoxy)ethane, bis[2-(2-methoxyethoxy)ethyl]ether, tetrahydrofuran, 1.
Examples include 3-dioxane, 1,4-dioxane, pyridine, picoline, dimethylsulfoxide, dimethylsulfone, tetramethylurea, hexamethylphosphoramide, tocresol, P-chlorophenol, anisole, and the like. Further, these organic solvents may be used alone or in combination of two or more.

The reaction temperature is usually 200°C or lower, preferably 50°C or lower.

The reaction pressure is not particularly limited, and the reaction can be carried out at normal pressure.

The reaction time varies depending on the type of solvent and the reaction temperature, and the reaction is usually carried out for a time sufficient to complete the production of the polyamic acid represented by the following formula (I[).

Usually 4 to 24 centimeters is sufficient.

Through such a reaction, a polyamic acid having a repeating unit of the following formula (n) is obtained.

(II) In the present invention, the logarithmic viscosity of polyamic acid, which is a precursor of polyimide, is required to be 0.1 to 4.0 a/g, preferably 0.3 to 2.5 a/g.

Furthermore, the obtained polyamic acid is heated to 100 to 400°C to imidize it, or chemically imidized using an imidizing agent such as acetic anhydride to produce a corresponding polyimide having a repeating unit of the following formula (1). is obtained.

Alternatively, 2.2-bis(4-(3-aminophenoxy)phenyl)-1,1,1,3,3,3-hexafluoropropane and pyromellitic anhydride are suspended or dissolved in an organic solvent. It is also possible to obtain a polyimide containing the repeating unit of formula (1) by simultaneously producing polyamic acid, which is a precursor of polyimide, and imidizing it with water. That is, a film-like or powder-like polyimide having the repeating unit of the above formula (1) can be obtained using a conventionally known method.

〔Example〕

The present invention will be specifically explained with reference to Examples, Comparative Examples, and Synthesis Examples.

Synthesis Example 2,2-bis(4-(3-aminophenoxy)phenyl)-1,1,1,3,3,3-hexafluoropropane used in the present invention was obtained as follows.

200 yuan! In a glass reaction vessel, 20 g (0,059 mol) of 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane and 24 g (0,14 mol) of m-dinitrobenzene were added. mol), 19.4 g of potassium carbonate and 10 g of N,N-dimethylformamide
0 ml was charged and reacted at 140-150°C for 7 hours. After the reaction was completed, it was cooled and discharged into 1000 all of water to give crude 2,2-bis[4-(3-nitrophenoxy)phenyl)-1 , 1,1,3,3,3-hexafluoropropane was separated as a tar. This tar-like substance was dissolved in benzene, washed with water, the benzene layer was dehydrated with magnesium sulfate, and column chromatography was performed using silica gel to obtain a yellow oil-like purified 2,2-bis(4-(3-nitrophenoxy) ) phenyl] −1,1
, 1,3,3,3-hexafluoropropane at 28.3
g (yield 83%) was obtained.

Then, crude 2,2-bis(4-(3-nitrophenoxy)phenyl)-1,1 was added to a 300 ml glass reaction vessel.
゜1.3.3.3-Hexafluoropropane 20g (
0,035 mol), 2 g of activated carbon, 0.2 g of ferric chloride hexahydrate and 100 mI of isopropyl alcohol.
1 and stirred under reflux for 30 minutes. Next 60-7
7 g (0.14 mol) of hydrazine hydrate at 0 °C
The mixture was added dropwise over a period of time, and the mixture was further stirred under reflux for 5 hours. After cooling, the catalyst was removed by filtration, and the isopropyl alcohol was distilled off by 6°. Add 80g of 17.5% hydrochloric acid, then add 10g of table salt and heat to 20-25℃ while stirring.
When cooled to a temperature, crystals precipitate. After filtering this, add 40 tal of isopropyl alcohol and 8 tal of 17.5% hydrochloric acid again.
After recrystallizing with 0 g, crystals are precipitated by neutralization with aqueous ammonia in 50% isopropyl alcohol.

After filtering, washing with water, and drying, recrystallization was performed using a mixed solvent of benzene and n-hexane to obtain 2,2-bis[4-(3
-aminophenoxy)phenyl) -Ll, 1.3.3
゜3-Hexafluoropropane was obtained.

Yield 13.6g (yield 75%), colorless crystals, melting point 13
7-139°C, purity 99.2% (by high performance liquid chromatography).

Elemental analysis (C2, H, N2 Fe 02 ) HNF Calculated value (%) 62.55 3.86 5.41 2
2.00 Analysis value (%'I 62.30 3.89 5
．． 20 21.95I R (KB r, cs+-”)
: 3480 and 3380 (amino group), 1280
(ether bond).

Example-1 2,2-bis(4-(3-aminophenoxy)phenyl)-1,1,1,3,3,3-hexane was added to a container equipped with a stirrer, a reflux condenser, and a nitrogen inlet tube. 10.36 g (0.02 mol) of fluoropropane and 44.16 g of N,N-dimethylacetamide were charged, and 4.273 g (0.02 mol) of pyromellitic anhydride was added at room temperature under a nitrogen atmosphere.
0196 mol) was added in portions, taking care not to allow the solution temperature to exceed 30°C, and the mixture was stirred at room temperature for about 20 hours. The logarithmic viscosity of the polyamic acid thus obtained is 0.55
d1/g.

To this polyamic acid solution, 88.3 g of N,N-dimethylacetamide was added, and after stirring for about 30 minutes, 8.08 g (0.08 mol) of triethylamine and 12.24 g (0.12 Approximately 7 hours after the completion of the dropwise addition of 0 moles of acetic anhydride, pale yellow polyimide powder began to precipitate. After further stirring at room temperature for about 20 hours, the mixture was filtered to obtain polyimide powder. After thrashing this polyimide powder with methanol, it was separated and
13.68 g (97% yield) after drying at ℃ for 24 hours
polyimide powder was obtained. X-ray analysis of this polyimide powder revealed that it had a degree of crystallinity of 28.2%.

The infrared absorption spectrum of this polyimide powder is shown in Figure 1. In this spectrum, the characteristic absorption bands of imide, around 1780aII-' and around 1720am-1, and the characteristic absorption band of ether bond, 1240cm+-1, are shown.
Significant absorption was observed in the vicinity.

The polyimide powder had a glass transition temperature of 231°C and a melting point of 387°C. (Measured by DSC method.

Same below. ) Also, the 5% weight loss temperature in air is 528
It was ℃. (Measured by DTA-TG, the same applies hereinafter.) Furthermore, the melt viscosity of the polyimide powder obtained in this example was measured using a Koka type flow tester (manufactured by Shimabara Seisakusho, CFT-500) under a load of 300 dazzles and a load of 0. When measured at 420° C. using an IC11 orifice, it was found to be 9.9×10 3 voids. The obtained strand was brownish-brown, transparent, and highly flexible.

Example-2 2,2-bis(4-(3-aminophenoxy)phenyl)-1,1,1,3,3,3-hexane was added to a container equipped with a stirrer, a reflux condenser, and a nitrogen inlet tube. 10.36 g (0.02 mol) of fluoropropane, 4.273 g (0.0196 mol) of pyromellitic anhydride and m-
Charge 133.8 g of cresol, and under nitrogen atmosphere,
The temperature was increased while stirring. At around 60°C, it became a transparent orange homogeneous solution. When heated to 150°C and continued stirring, pale yellow polyimide powder gradually began to precipitate in about 1 hour. After further stirring under heating for 5 hours, the mixture was filtered to obtain polyimide powder. This polyimide powder was washed with methanol and acetone, and then dried under reduced pressure at 180°C for 24 hours to obtain 13.03 g (yield: 92.3%) of polyimide powder. The infrared absorption spectrum of the polyimide powder obtained here was similar to that shown in FIG.

X-ray analysis of this polyimide powder revealed that it was 44.7
% crystallinity. Further, this polyimide powder was completely insoluble in aliphatic halogenated hydrocarbon solvents such as methylene chloride and chloroform.

The glass transition temperature of this polyimide powder is 232°C, the melting point is 388°C, and the 5% weight loss temperature in air is 5%.
The temperature was 30°C.

Furthermore, the melt viscosity of the obtained polyimide powder was measured in the same manner as in Example-1 and found to be 7.3 x 103 voids. The obtained strand was brownish-brown and transparent and highly flexible, similar to that obtained in Example-1.

Comparative Example-1 Commercially available Ultem 1000 (υLTEM 1000:
When pellets manufactured by General Electric Company (trade name) were dissolved in methylene chloride, more than 20% by weight was dissolved.

Example-3 2,2-bis(4-(3-aminophenoxy)phenyl)-1,1,1,3,3,3-hexane was added to a container equipped with a stirrer, a reflux condenser, and a nitrogen inlet tube. 5.18 g (0.01 mol) of fluoropropane and 22.1 g of N,N-dimethylacetamide were charged, and 2.18 g (0.01 mol) of pyromellitic anhydride was added at room temperature under a nitrogen atmosphere.
1 mol) was added in portions, being careful not to allow the solution temperature to exceed 30°C, and the mixture was stirred at room temperature for about 20 hours.

The logarithmic viscosity of the polyamic acid thus obtained is 2°1 a
/g.

Moreover, after casting this polyamic acid solution on a glass plate, it was heated at 100°C, 200°C and 300°C for 1 hour each to obtain a polyimide film. The glass transition temperature of this polyimide film is 248℃ (TMA Needleman Corporation, hereinafter the same), and the 5% weight loss temperature in air is 5.
The temperature was 26°C. Also, the tensile strength is 12.0kg/a1
2. The tensile elongation rate was 10%. (Measurement methods are based on ASTM D-882) Comparative Example 2 2,2-bis(4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane Polymerization was carried out in the same manner as in Example 3, except that 2,2-bis(4-(4-aminophenoxy)phenyl)-1,1,1,3,3,3-hexafluoropropane was used instead. I did it.

The logarithmic viscosity of the polyamic acid thus obtained was 1.25 d.
It was l/g. After casting a part of this polyamic acid solution on a glass plate,
Each was heated for 1 hour to obtain a polyimide film. The glass transition temperature of this polyimide film was as high as 310°C.

Comparative Example-3 3.3', 4.4' instead of pyromellitic anhydride
Polymerization was carried out in the same manner as in Example 3 except that -benzophenone tetracarboxylic dianhydride was used.

(The logarithmic viscosity of the polyamic acid obtained is 0.92 d.
It was l/g. After casting a part of this polyamic acid solution on a glass plate,
Each was heated for 1 hour to obtain a polyimide film. The glass transition temperature of this polyimide film was as low as 206°C.

〔Effect of the invention〕

In addition to the excellent heat resistance inherent to polyimide, the present invention
The present invention provides a completely new polyimide that has excellent solvent resistance and processability.

[Brief explanation of drawings]

FIG. 1 is an example of an infrared absorption spectrum diagram of the polyimide powder of the present invention.

Claims (1)

[Claims] 1) Formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ It has a repeating unit represented by (I) and its precursor is the formula (
II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) Logarithmic viscosity of polyamic acid having repeating units represented by (N,N-dimethylacetamide solvent, concentration 0.5 g
/100ml solvent, measured at 35°C) is 0.1 to 4.
Polyimide with 0 dl/g.