JPH03264333A - Polyimide stretched formed body and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain aromatic polyimide stretched formed body having superior physical properties by a constitution wherein the formed body concerned consists of specified aromatic tetracarboxylic acid component and specified aromatic diamine component. CONSTITUTION:Thin film or fibrous body is made out of aromatic polyamic acid obtained by polymerizing in organic polar solvent almost equimolar aromatic tetracarboxylic acid component, which contains 80mol% or more of pyromelletic acids, and aromatic diamine component, which contains 80mol% or more of 3,4'-diamino diphenyl ether. Next, the thin film or fibrous body made out of said polyamic acid solution is heated up to 200 deg.C or higher so as to form polyimide formed body. Said polyimide formed body is stretched at 250-450 deg.C by the draw ratio of 150-350%. Finally, the resultant stretched formed body is treated by heating up to 200 deg.C or higher. The formed body has the tensile strength of 20-100kg/mm<2> and the Young's modulus of 700-3,000kg/mm<2>.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is made of a specific aromatic polyimide based on pyromellitic acid, and is highly oriented and has extremely excellent physical properties, especially an extremely high Young's modulus (tensile modulus). The present invention relates to a stretched aromatic polyimide molded article (for example, a film, a fiber, etc.), and a novel manufacturing method for producing the stretched polyimide molded article by stretching it under specific conditions.

By using a specific cyanogen component, the pyromellitic acid-based polyimide stretched molded article of the present invention has a higher level of oxidation than this type of aromatic polyimide film molded by conventional solution casting method. It has tensile strength, heat resistance, etc., as well as an extremely high Young's modulus, so it can be suitably used for various purposes, especially as a thin film or thin fiber.

[Description of prior art]

Conventionally, as a method for producing a heat-shrinkable aromatic polyimide film (stretched film), for example, as described in Japanese Patent Publication No. 57-41330, a biphenyltetracarunic acid-based aromatic polyimide precursor is used. (polyamic acid or polyamic acid) solution at 20-20%
The film was formed by a casting method while maintained at a temperature of 0°C, and then
A polyimide film in which at least 50% of the amic acid bonds of boria-stuccinic acid obtained by heating to a temperature of 00°C and drying until the volatile content becomes 10% by weight or less is converted to imide bonds, and then, A method has been proposed in which the polyimide film is stretched in at least one direction at a stretching ratio of 1.05 to 5 times at a temperature of 100 to 500°C.

However, although it is possible to produce a specific biphenyltetracarboxylic acid-based polyimide film having heat shrinkability with the above-mentioned known method, it is possible to produce an aromatic film obtained from pyromellitic acids and 4,4'-diaminodiphenyl ether. consisting of polyamic acid and an organic polar solvent.
Regarding the "self-supporting unstretched film," the stretching operation itself was not easy, and the resulting stretched molded product did not have sufficiently high physical properties.

[Problems to be solved]

It is an object of the present invention to provide a pyromellitic acid-based aromatic polyimide stretched molded article with high physical properties (in particular, a high Young's modulus), and to easily produce the stretched aromatic polyimide molded article with high physical properties. The goal is to provide a method to do so.

[Means to Solve the Problems] The first invention of this application provides an aromatic tetracarboxylic acid component containing 80 mol% or more of pyromellitic acids and 3,4'
- An aromatic cyanide containing 80 mol% or more of diaminodiphenyl ether, and a tensile strength of 20 to 100 kg/an.
2 and a Young's modulus of 700 to 3000 kg/m
It relates to a polyimide stretched molded product that is
Furthermore, the second invention contains 80 mol% of pyromellitic acids.
The aromatic tetracarboxylic acid component containing 3゜4''
- forming a thin film or fibrous body from an aromatic boric acid solution obtained by polymerizing approximately equimolar amounts of an aromatic diamine fraction containing 80 mol% or more of diaminodiphenyl ether in an organic polar solvent; Next, the thin film or fibrous body of the boriabroscinic acid solution is heated to 200"C or higher to form a polyimide molded body, and the polyimide molded body (unstretched molded body) is heated at a temperature of 250 to 450°C. So, 1
．． Stretched 5 to 3 degrees 5 times, and finally, the stretched molded body was stretched 20
The present invention relates to a method for producing a stretched polyurethane shaped body, which is characterized by heat treatment at a temperature of 0°C or higher.

The invention of this application will be explained in more detail below.

The aromatic polyimide in the stretched polyimide of the present invention is, for example, pyromellitic acid or its acid dianhydride,
Alternatively, an aromatic tetracarboxylic acid component containing at least 80 mol%, preferably 90 mol% or more of at least one kind of pyromellitic acid selected from acid esters thereof, and 34'-diaminodiphenyl ether,
A pyromellitic acid-based aromatic polyimide obtained by polymerizing an aromatic sia noble fraction containing 0 mol% or more, preferably 90 mol% or more, using both components in approximately equal moles. It is.

The pyromellitic acid-based aromatic polyimide has a second-order transition temperature of about 280 to 380°C, particularly preferably 30°C.
The temperature is preferably about 0 to 360°C.

In the above-mentioned aromatic tetracarboxylic acid component, examples of tetracarboxylic acid compounds that can be used in combination with pyromellitic acids include biphenyltetracarboxylic acid or its acid dianhydride, benzophenonetetracarboxylic acid or its acid dianhydride, etc. Anhydride, bis(3,4-dicarboxyphenyl)methane or its acid dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane or its acid dianhydride, bis(3,4-dicarboxyphenyl)propane or its acid dianhydride. (carboxyphenyl) sulfone or its acid dianhydride.

In the aromatic diamine component, examples of aromatic diamine compounds that can be used in combination with 3,4'-diaminodiphenyl ether include 4,4'-diaminodiphenyl ether and 3,3'-diaminodiphenyl ether. other diaminodiphenyl ethers,
Diaminodiphenylalkanes such as 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 3,4'-cyanodiphenylpropane, and 4,4'-
Examples include diaminodiphenylsulfone, 4,4''-diaminodiphenylsulfide, and especially 4,4''-diaminodiphenylsulfide.
Diaminodiphenyl ethers such as 4'-cyanodiphenyl ether are preferred.

In the polyimide stretched molded article of the present invention, if the content of 3,4°-diaminodiphenyl ether in the aromatic diamine component for producing the aromatic polyimide is too low, the diamine component with such a low content It is not suitable because it becomes difficult to stretch the aromatic polyimide shaped body obtained from the method, and the stretched body made of the aromatic polyimide has deteriorated mechanical properties.

In particular, the aromatic polyimide stretched molded article of the present invention is obtained from an aromatic tetracarboxylic acid component whose main component is the above-mentioned pyromellitic acid and an aromatic diamine component whose main component is 3,4°-diaminodiphenyl ether. pyromellitic acid-based aromatic polyimide", and has a tensile strength of 20-100 kg/kg, preferably 25-9
5 kg/kaku2, and Young's modulus (tensile modulus) of 700 to 3000 kg/mz, preferably 750 to
It is a polyimide stretched molded product with a weight of about 2600 kg/mm2.

The polyimide stretched molded article of the present invention has the above-mentioned tensile strength and Young's modulus, and has an elongation at break of 10.
% or less, especially about 2 to 8%, for example, a film-like body (sheet-like body) with a thickness of 500 am or less, especially about 1 to 200 μm, or a diameter of 1000 μm or less.
It is preferable to use a highly oriented aromatic polyimide stretched molded body such as a fibrous body having a diameter of 1 to 500 μm or less.

Conventionally, a pyromellitic acid-based aromatic polyimide having a Young's modulus of 700 kg/mm2 or more as well as high heat resistance and tensile strength of 20 kg/mm2 or more, such as the stretched stretched molded product of the present invention, has been produced. Stretched body 1 was completely unknown.

In the method for producing a polyamide stretched molded article of the present invention,
For example, first, the aromatic tetracarboxylic acid component whose main component is pyromellitic acids and the aromatic diamine component whose main component is 3.4'-diaminodiphenyl ether are mixed in approximately equal moles (±2.0 mol%). (difference within ±1.5%) in an organic polar solvent, preferably at a temperature of 80°C or less, particularly preferably 0 to 60°C. ” solution to form a thin film, fibrous body, etc. of the polyamine chloride solution,
These thin films, fibrous bodies, etc. are heated at high temperature to remove the solvent and imidize the polymer to form an unstretched polyimide molded body (unstretched molded body), and then By stretching the body at a temperature of 250 to 450°C and a stretching ratio of 1.5 to 3.5 times, a stretched molded body of pyromellitic acid-based aromatic polyimide is formed with good reproducibility, and finally, the stretching A pyromellitic acid-based polyimide stretched molded product can be produced by heat-treating the molded product at a temperature of 200° C. or higher.

In the production method of the present invention, the "residues of aromatic diamine of short polyimide" forming the unstretched molded article of pyromellitic acid-based aromatic polyimide are replaced by 3.4'-diaminodiphenyl ether (3, 4"-DADE) residue is particularly important, and the above-mentioned (7) 3.4'-D A
Polyimide consisting of residues of diamines other than DE may not be able to be stretched sufficiently at high temperatures, and even if stretching is possible, a polyimide stretched molded product with high physical properties cannot be obtained. (Comparative example 2
).

Furthermore, the production method of the present invention is characterized in that the pyromellitic acid-based polyimide molded product (unstretched molded product) is stretched at high temperature; for example, as shown in Comparative Examples 2 and 3, A polyamic acid molded product obtained from the above-mentioned pyromellitic acid and 3,4゛-cya-nodiphenyl ether is stretched, and then the polymer forming the stretched molded product is imidized to form a polyimide stretched molded product. Even if produced, it is not possible to obtain a polyimide stretched molded product with high physical properties.

The organic polar solvent for polymerization used in the production of the aromatic polyamic acid mentioned above is an organic polar solvent that can uniformly dissolve polyamic acid in an amount of 3% by weight or more, particularly 5% by weight or more, such as , N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacedodando, N,N-diethylacetamide, N
, N-di-lower alkylcarboxylamides such as N-methylethylacetamide, organic polar solvents such as N-methyl-2-pyrrolidone, dimethylsulfoxide, diethylsulfoxide, dimethylsulfone, diethylsulfone, and hexamethylsulfoxide, respectively. The above-mentioned respective organic polar solvents are preferably the same type of organic polar solvents used in the production method of the present invention. "Molded object" is
The molded product must have self-supporting properties and be in a substantially unstretched state without being stretched to a stretching ratio of 1.2 times or more, and the method for producing the unstretched molded product is particularly limited. For example, using a polyamic acid solution in which the above-mentioned aromatic polyamic acid is uniformly dissolved in an organic polar solvent, the temperature is 40 to 150°C, particularly preferably 40°C.
From a liquid film or fibrous material formed by solution casting film forming method at a temperature of ~120°C or by spinning at a similar temperature, 200°C
As described above, an unstretched molded body such as a polyimide film or solidified fiber can be produced by evaporating and removing most of the solvent at a temperature of 200 to 400° C. and also imidizing the aromatic polyamic acid. .

In the manufacturing method of this invention, the "unstretched polyimide molded body" obtained by G straining as described above is stretched at a stretching temperature of 250.
~450°C1, preferably around 280~400°C, 1.
Stretch (-axial or biaxial stretching) 5 to 3.5 times, preferably 1.8 to 3.2 times in at least one direction, and then stretch the stretched molded product at 200°C or higher, preferably 20°C.
A pyromellitic acid-based aromatic polyimide stretched molded product is produced by heat treatment at a high temperature of 0 to 550°C, particularly 250 to 530°C.

The production of the above-mentioned unstretched molded body and its stretching operation can be carried out by known means. The unstretched molded body is installed so as to be stretched so that there is no slack between the members, and both ends of the unstretched molded body are fixed to supporting members using fixing devices such as chucks, and the distance between the pair of supporting members is gradually widened along the base. This can be done by stretching the unstretched molded body J to an appropriate stretching ratio.

When heat-treating the above-mentioned stretch molded product at a temperature of 200°C or higher, at least both ends of the stretched molded product in the stretching direction of the stretched molded product to be heat-treated are fixed at a fixed distance with a pair of supporting members, a frame, etc. It is preferable to carry out the heat treatment by
In addition, for example, heating by multi-stage temperature elevation, such as firstly performing a primary heat treatment at a temperature of 200 to 280°C, then secondary heating at a temperature of 280 to 350"C, and then performing a tertiary heat treatment at a temperature higher than 350"C. Processing can also be performed.

It is best to perform the above heat treatment on the aromatic polyimide stretched molded product at a final temperature of 350 to 550'C8, especially 360 to 520"C, because a stretched molded product with high physical properties can be obtained. .

In the production method of the present invention, the aromatic polyamic acid used for producing the polyimide molded body (unstretched molded body) is produced from an aromatic tetracarboxylic acid component and an aromatic diamine component at a low temperature of about 60°C or less. It is a polyamic acid-based soluble polyamic acid (polyimide precursor) obtained by the polymerization of
0.5 g/loomp solvent, solvent iN, N-dimethylacetamide) is about 0.1 to 7, especially about 0.2 to 5, and the imidization rate is about 30% or less, especially 20% or less, more preferably It is preferably a polymer that can be uniformly dissolved in the above-mentioned organic polar solvent to a concentration of about 40% by weight or less.

The above-mentioned logarithmic viscosity is a value calculated by the following formula.

The above-mentioned imidization rate is the imidization rate determined by infrared analysis method (IR method), and is an absorption peak of 1780c based on imide bonds in the infrared absorption spectrum of the sample.
The yield rate can be calculated from the ratio of the absorbance of m-' and the absorbance of 1510ca+-', which is an absorption peak based on the phenyl group.

In the production method of the present invention, a specific pyromellitic acid type obtained from an aromatic tetracarboxylic acid component containing pyromellitic acids as a main component and an aromatic diamine component containing 3,4°diaminodiphenyl ether as a main component. Aromatic polyimide shaped body (unstretched shaped body) J of 250 to 450''
The main characteristics are stretching 1.5 to 3.5 times at a high temperature of C and finally heat treatment at a high temperature.By such a manufacturing method, a pyromellitic acid-based material with high physical properties can be produced. This makes it possible to produce aromatic solidified and stretched products with good reproducibility.

〔Example〕

Examples 1-8 32.719 g (0.15 mol) of pyromellitic dianhydride and 30°03 of 3,4'-cyanodiphenyl ether
6 g (0.15 mol) in 565 g of N,N-dimethylacetamide (DMAc) solvent at a polymerization temperature of 25°C.
and aromatic polyamic acid solvent obtained by polymerizing for 6 hours in a nitrogen atmosphere [polymer concentration: 10% by weight, 25°C
solution viscosity (solution viscosity measured by rotational viscometer);
130 voids, logarithmic viscosity (1 degree: 0.5% by weight, measurement temperature: 30°C) il, 80) was prepared.

Then, the aromatic polyamic acid solution was solution casted onto a glass plate to a uniform thickness at about 50°C, and the resulting liquid thin film was dried at 55°C for 1 hour, and then , vacuum dried at 50°C for 24 hours, then dried at 150°C for 6 hours.
Form a pyromellitic acid-based aromatic polyimide film (polymer imidization rate of 90% or more, polymer secondary transition temperature: 330°C) under the conditions of 0 minutes, 200°C for 60 minutes, and 250″C for 120 minutes. did.

The width of the above polyimide film is 10mm and the length is 70++.
Cut the polyimide film into a rectangular piece of +m, and install the polyimide film piece by stretching it between a pair of supporting members (width 10 mm) arranged on the base at an interval of about 50 mm, without sagging, and attaching both ends of the film. The film was held between the support members for 10 minutes at the stretching temperature shown in Table 1 by clamping and fixing it with a chuck, and in that state, raising the temperature at a temperature increase rate of 1° C./sec, and then holding the film between the support members. The polyimide film was stretched at the stretching ratio shown in Table 1 by gradually moving one of the supporting members within about 1 minute to increase the distance between the supporting members.

In Examples 1 to 6, the physical properties of the stretched molded products thus obtained were measured.

Moreover, in Examples 7 and 8, after performing the above-mentioned stretching operation,
The stretched polyimide film (stretched molded product) was further heat-treated under the conditions shown in Table 1 while the stretched polyimide film was attached to the support member to produce an aromatic polyimide stretched molded product.

Table 1 shows the physical properties of the stretched molded bodies obtained as described above.

Comparative Example 1 A polyimide stretched molded body was produced in the same manner as in Example 1, except that the stretching ratio was changed to 1.3.

Table 1 shows the physical properties of the stretched molded product obtained as described above.

Comparative Example 2 A polyamic acid solution was prepared in the same manner as in Example 1, except that 4,4'-diaminodiphenyl ether was used as the aromatic diamine component instead of 3,4'-cyanodiphenyl ether.

A polyimide stretched molded article was produced in the same manner as in Example 1 except that the polyamic acid solution was used and the stretching ratio was 1.8.

Table 1 shows the physical properties of the stretched molded product obtained as described above.

[Actions and effects of the present invention]

The aromatic polyimide stretched molded article of the present invention is a stretched molded article such as a film-like body or a fibrous body made of a highly heat-resistant aromatic polyimide obtained mainly from pyromellitic acids and 3,4'-diaminobiphenyl ether. and has a tensile strength of 20 to 100 kg/m2 and a Young's modulus (tensile modulus) of 800 to 3000 kg/m
This is the first time to provide a pyromellitic acid-based aromatic polyamide stretched molded product having high physical properties such as m2.

The method for producing a stretched aromatic polyimide molded article of the present invention is to produce a polyimide molded article using an aromatic polyamic acid solution obtained mainly from pyromellitic acids and 3,4''-diaminobiphenyl ether. In this method, an aromatic polyimide stretched molded body having the above-mentioned high physical properties can be manufactured with good reproducibility by stretching and heat-treating a stretched molded body (unstretched molded body) at a high temperature.

Claims (2)

[Claims] (1) consisting of an aromatic polyimide obtained from an aromatic tetracarboxylic acid component containing 80 mol% or more of pyromellitic acids and an aromatic diamine component containing 80 mol% or more of 3,4'-diaminodiphenyl ether; And, the tensile strength is 20~100kg/mm^2,
A polyimide stretched molded article having a Young's modulus of 700 to 3000 kg/mm^2. (2) An aromatic tetracarboxylic acid component containing 80 mol% or more of pyromellitic acids and an aromatic diamine component containing 80 mol% or more of 3,4'-diaminodiphenyl ether in approximately equal moles in an organic polar solvent. forming a thin film or fibrous body from the aromatic polyamic acid solution obtained by polymerization, and then heating the thin film or fibrous body of the polyamic acid solution to 200°C or higher to form a polyimide molded body, Then, the polyimide molded body was
A method for producing a polyimide stretched molded body, which comprises stretching the stretched polyimide body by 1.5 to 3.5 times at a temperature of 0°C, and finally heat-treating the stretched body at a temperature of 200°C or higher.