JPS60193618A - Manufacture of aromatic polyimide film - Google Patents

Abstract

PURPOSE:To contrive to separate easily a self supporting film from a base body by a method in which at the manufacture of aromatic polyimide film by casting process, the aromatic polyamix acid solution containing a specified amount of carboxylic acid, is cast on a base body and is made into a film by drying. CONSTITUTION:Aromatic polyamix acid solution contains 0.01-70pts.wt. carboxylic acid shown by a general formula RCOOH to 100pts.wt. aromatic polyamix acid. Said solution has 4-35wt% polymer concentration and logarithmic viscosity with the molecular weight equal to or larger than 0.2. Said solution is filtered and deareated, and then is cast with uniform thickness on a metallic drum from a hopper and a T-die. Then it is heated by hot blast or infrared ray, etc. and the solvent therein is gradually removed. The solution is preliminarily dried until it has self supporting property. Next, the film with self supporting property is separated from the metallic drum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an aromatic polyimide film in which an aromatic polyamic acid solution containing a specific amount of carboxylic acid as an internal additive is formed by a casting method.

Aromatic polyimide film is produced by casting an aromatic polyamic acid solution onto a substrate in the form of a film, heating it to evaporate the solvent until it becomes a self-supporting film, and peeling off the self-supporting polyamic acid film from the substrate. It is manufactured by a method in which the remaining solvent is removed by further heating and the imidization of the polyamic acid is completed. However, conventionally known methods.

The self-supporting film is not easy to peel off from the substrate and has the disadvantage of being torn or damaged during peeling.

The present inventors conducted extensive research on a method for producing an aromatic polyimide film that does not have the above-mentioned drawbacks, and found that an aromatic polyamic acid solution containing a specific amount of carboxylic acid was cast onto a substrate and dried to form a film.

The present invention was completed by discovering that a self-supporting film can be easily peeled off from a substrate.

That is, one aspect of the present invention is a method for producing an aromatic polyimide film by a casting method.

Based on 100 parts by weight of aromatic polyamic acid.

An aromatic polyamic acid solution containing 0.01 to 70 parts by weight of a carboxylic acid represented by the general formula (wherein R is a substituted or unsubstituted alkyl group, cycloalkyl group, or aryl group) is applied onto a substrate. This relates to a method for producing an aromatic polyimide film, which comprises casting the polyamic acid film on a substrate, peeling the self-supporting polyamic acid film from the substrate after drying, and further heating to remove the solvent and imidize the polyamic acid. be.

The aromatic polyamic acid solution used in the present invention is obtained by reacting an aromatic tetracarboxylic acid component and an aromatic diamine component in, for example, an organic polar solvent.

The aromatic tetracarboxylic acid component is as follows.

There are no particular limitations. 1 For example, 3.3', 4.4'-biphenyltetracarboxylic dianhydride 1 2,313'+4'-
Biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(ro,4-dicarboxyphenyl)ether dianhydride, 3. a, 3', 4'-benzophenone tetracarboxylic dianhydride, salts and esterified derivatives of these tetracarboxylic acids, and mixtures of the above-mentioned tetracarboxylic acids. A part of the aromatic tetracarboxylic acid component may be replaced with another tetracarboxylic acid component (for example, an aliphatic component).

The aromatic diamine component mentioned above is not particularly limited, and 1
For example, 4,4'-diaminodiphenyl ether, 3.3
'-N'-Abanodiphenyl ether, Lochang'-dimethyl-4,4'-diaminodiphenyl ether.

Diphenyl ether diamines such as Naro'-dimethquine-4,4'-diaminodiphenyl ether.

4.4'-diaminodiphenylthioether, 3'
- diphenylthioether thread diamines such as diphenylthioether, 3,3'-diaminobenzophenone, 4
．． Benzophenone diamines such as 4'-diaminobenzophenone, filtrate, 3'-diaminodiphenylphosphine, diphenylphosphine diamines such as 4,4'-diaminodiphenylphosphine, filtrate, 3'-diaminodiphenylmethane, 4',4'-diamino Diphenylmethane-based diamides such as diphenylmethane 71 0 + m r
Examples include p-phenyl diamine.

A part of the aromatic diamine component may be replaced with another diamine component (for example, an aliphatic diamine component).

As an aromatic polyamic acid in the present invention.

Otsu, 3', 4. d-biphenyltetracarboxylic dianhydride and/or pyromellitic dianhydride and 4,4'
Aromatic polyamic acids obtained from -diaminodiphenyl ether and/or 1dp-phenylenediamine are preferred.

As the organic polar solvent, N-methylpyrrolidone,
Pyridine, N,N-dimethylacetamide.

Preferred solvents include nitrogen-containing compounds capable of dissolving polyamic acids, such as N,N-dimethylformamide, dimethylsulfoxide, and tetramethylurea. It is also possible to use organic solvents such as aromatic hydrocarbons together with these organic polar solvents.

In the above method, the polymer concentration in the aromatic polyamic acid solution is preferably 3 to 40% by weight, particularly 4 to 35% by weight.

Further, in the above method, the aromatic polyamic acid has a logarithmic viscosity (filtration 0°C, concentration Oi 5 f// 100 Kl
The molecular weight (measured in a solvent) is preferably 0.1 or more, particularly 0.2 or more.

The carboxylic acid used in the present invention is represented by the following general formula (wherein R is a substituted or unsubstituted alkyl group, cycloalkyl group, or aryl group).

One example of those having the above general formula is acetic acid.

Propionic acid, n-butyric acid, inbutyric acid, n-valeric acid.

Invaleric acid, methylethyl acetate, caproic acid, heptonic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, myristic acid.

Palmitic acid, margaric acid, stearic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid.

Monofluoroacetic acid, difluoroacetic acid, drifluoroacetic acid, cyanacetic acid, vinylacetic acid, methoxyacetic acid.

Cyclohebanoic acid, cyclohexanoic acid, benzoic acid.

Examples include phenylacetic acid.

If the carboxylic acid added to the aromatic polyamic acid solution has a high boiling point, it will be easily distilled off in the process of further heating the self-supporting film peeled off from the cast substrate to remove the remaining solvent and complete imidization. The polyimide film remained in the film, and eventually caused a decomposition reaction and colored the polyimide film.

The boiling point of carboxylic acid should be below 300°C or
It is preferable to use a material that sublimes at a temperature of 00° C. or lower.

It is necessary to add the carboxylic acids in an amount of 1 to 70 parts by weight, preferably 0.1 to 60 parts by weight, per 100 parts by weight of the aromatic polyamic acid.

If the amount of carboxylic acid is less than the above-mentioned lower limit, there will be no effect, and if the amount of carboxylic acid is more than the above-mentioned upper limit, there will be no particular effect and it will be rather disadvantageous.

In the above method, the carboxylic acid can be added at any stage of the preparation of the polyamic acid solution.

That is, the aromatic tetracarboxylic dianhydride and the aromatic diamine may be polymerized after adding the carboxylic acid to an organic polar solvent, or the carboxylic acid may be added during one polymerization.
It may be added after polymerization.

In the method of the present invention, the method of producing a polyimide film from an aromatic polyamic acid solution composition by a casting method may be carried out by any known production method2. When manufacturing film.

The aromatic polyamic acid solution composition is filtered and defoamed, uniformly cast onto a metal drum or metal belt from a hopper or T-die, and heated to 60 to 160°C with hot air, infrared rays, etc. to gradually remove the solvent. The film is pre-dried until it becomes self-supporting, and then the self-supporting film is peeled off from the metal drum or belt. The heating loss of the self-supporting film at this time [drying at 420° C. for 20 minutes, 2 is determined by the following equation based on the M amount WI before drying and the weight W2 after drying.

Heating loss (weight %)” ((W+-wz)/W+) x1o
o] is 15-605-60 parts by weight, preferably 25-5
55 to 55 parts by weight of the self-supporting film and 100 to 55 parts by weight of the self-supporting film.
After drying at a temperature of 450 DEG C., the solvent contained in the film is removed and the amide-acid bond of the polyamic acid is converted into an imide bond to produce an aromatic polyimide film. Post-drying is carried out by passing the self-supporting film between a number of rolls or by holding both ends of the film under slight tension with clips or pins of a tenter.

Reference examples, examples and comparative examples are shown below.

Here, the peel strength is a metal plate (40mm x 150wm)
A spacer (inner diameter 20 mm x 130 mm) was placed on the film, a polyamic acid solution was cast, and after pre-drying, one end of the film was peeled off from the substrate, and the peel strength was measured by peeling 90' using a tensile tester.

Reference Example 1 3,3' in N,N-dimethylacetamide 2471F
, 4.4'-biphenyltetracarboxylic dianhydride 2
94.22f and p-phenylenediamine 10'8.14
1 was added and reacted at room temperature for about 10 hours to obtain a polyamic acid solution. The logarithmic viscosity of this polyamic acid was 2.10, and the 30f viscosity of the solution was 1300 voids.

Reference Example 2 6, in N,N-dimethylacetamide 3037ji'
294.22 r of 4,4/-biphenyltetracarboxylic dianhydride and 200.24 f of 4,4'-diaminodiphenyl ether were added and reacted at room temperature for about 10 hours to obtain a polyamic acid solution. The logarithmic viscosity of this polyamic acid is 1.50, and the viscosity of the solution at 30°C is 11
It was 00 Boys.

Reference Example 3 4.4 in N,N-dimethylacetamide 257OS'
After adding 200.24 f of '-diaminodiphenyl ether, 218.128 i of pyromellitic dianhydride was added and reacted for about 6 hours to obtain a polyamic acid solution. The logarithmic viscosity of this polyamic acid is 1.60, and the solution has a logarithmic viscosity of 30
The viscosity at °C was 300 poise.

Examples 1 to 22 and Comparative Examples 1 to 9 Polymer 100 of the polyamic acid solution prepared in Reference Example 1
A predetermined weight part of the compound shown in Table 1 was added to the weight part, and the mixture was stirred at room temperature for 6 hours to obtain a polyamic acid solution composition. This composition was cast onto the metal substrate shown in Table 1 using a 0.48 spacer, and then dried with hot air at 100° C. for 30 minutes. The self-supporting film was peeled off from the metal substrate, and each of these films was subjected to a tensile strength of 25 to 40 kg/-. polymer, 10
A predetermined weight part of the compound shown in Table 2 was added to 0 weight part, and the mixture was stirred at room temperature for 6 hours to obtain a polyamic acid solution composition. This composition was applied to stainless steel at 18 to 23 kg/
It was strong, exhibiting a tensile strength of - and an elongation of 80 to 120 inches. The results are summarized in Table 2.

Examples 28 to 0 and Comparative Example 11 Polymer 100 of the polyamic acid solution prepared in Reference Example 6
A predetermined weight part of the compound shown in Table 3 was added to the weight part, and the mixture was stirred at room temperature for 6 hours to obtain a polyamic acid solution composition. This composition was applied to stainless steel from 16 to 22 to 9/-
It was strong, exhibiting a tensile strength of 60% to 100%. The results are summarized in Table 2.

Table 2 Table 1

Claims (1)

[Claims] A method for producing an aromatic polyimide film by a casting method. Based on 100 parts by weight of aromatic polyamic acid. Aromatic boric acid solution containing 0.01 to 70 parts by weight of a carboxylic acid represented by the general formula (wherein R is a substituted or unsubstituted alkyl group, cycloalkyl group, or aryl group) An aromatic polyimide characterized in that after being cast on a substrate and dried, a self-supporting polyamic acid film is peeled from the substrate, and the solvent is removed by further heating to form a polyamide 2 film D'r imidation. Film manufacturing method.