JPH0260932A - Polyimide film - Google Patents

Abstract

PURPOSE:To make it possible to form a polyimide film with improved alkall reeietance by modifying the terminals of an acid anhydride-terminated polyamic acid and then imidattng it. CONSTITUTION:A polyimide film having a etructure of formula I on ite terminals, gwherein H ie formula ll, rll or IV; X1-9 are each-B,-P,-Cl, Br, OCH3,- COOH,-CH3, formula V' -NH2,-NO2 or -CN, is especially effectively formed by using pyromellitic dtanhydride and diamlnodlphenyI ether and/or p- phenylenediamine ae the raw material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a new polyimide film, and more particularly to a polyimide film with improved alkali resistance by terminal modification.

[Prior art, problem to be solved by the invention] Polyimide, which is currently widely used due to its high heat resistance and insulation properties, is
Generally due to its imide group.

It is said to have poor water and alkali resistance. For this reason, even though other physical properties are extremely excellent, their applications are often limited.

In addition, methods such as copolymerizing water-repellent monomers and adding additives have been proposed as methods for improving the water and alkali resistance of polyimide, but these methods In the latter case, a third component is directly introduced into the main chain, which results in different physical properties from the originally designed one, and in the latter case, a low-molecular substance is introduced into the polymer, which causes a decrease in mechanical properties. It has the disadvantage of being easy to use.

There is also a method of inducing crosslinking by adding a polyfunctional compound or heat treatment to improve the apparent solvent resistance, but this method is generally known to significantly reduce mechanical properties such as elongation.

[Means to solve the problem]

In view of the above circumstances, the present inventors have conducted repeated research to solve these technical problems, and as a result, have developed a polyimide film that does not have the above-mentioned drawbacks.
XS X&X I ~9 are -H and -F, respectively
, -C1, Br%-NO2, -CN) were found.

To explain in detail, the present inventors have discovered that by terminally modifying the acid anhydride-terminated polyamic acid to introduce a water-repellent group, and then imidizing it, it is possible to improve the alkali resistance without having the above-mentioned drawbacks. This is what led to the discovery of the present invention.

As an example of the method for producing the polyimide of the present invention, an acid dianhydride and a diamine are polymerized in the presence of an excess amount of the acid dianhydride to obtain an acid anhydride-terminated polyamic acid, and the terminal acid of this polyamic acid is An example of this method is to react the anhydride group with an amine having R5 to modify the end thereof, and then imidize it (dehydration ring closure).

As raw materials for the polyimide used in the present invention, all acid anhydrides and diamines that are known polyimide raw materials can be used, but in particular, pyromellitic dianhydride, diaminodiphenyl ether, and (or ) Effective when using paraphenylenediamine as the main raw material. Solvents used when producing polyamic acid include N,N'-dimethylformamide, N,N
'-Dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, tetrahydrofuran, etc. One or more types of solvents commonly used in the synthesis of polyamic acids can be used, but they react depending on the solubility of the monomer. N,N'-dimethylformamide and N,N'dimethylacetamide are preferred from the viewpoint of balance of activity and the like. Furthermore, it is also possible to partially mix and use nonpolar solvents such as Hensen, toluene, and xylene.

In addition, as a compound that reacts with the acid anhydride group, any compound with a hydrophobic molecular chain can be used, but from the viewpoint of the magnitude of the effect and the balance of various physical properties, primary amines having Ri or derivatives thereof are preferred. preferable. Especially aromatic rings
Aromatic amines and/or N-1-lyntylsilyl aromatic amines having a H-substituted fluorine atom are preferred. Specific examples of such compounds include parafluoroaniline, metafluoroaniline, orthofluoroaniline, 2,5-difluoroaniline, 2,4-difluoroaniline, 2,4.6-)lifluoroaniline,
N-trimethylsilyl parafluoroaniline, N trimethylsilyl metafluoroaniline, N trimethylsilyl orthofluoroaniline, N trimethylsilyl-2,4
-difluoroaniline, N-trimethylsilyl-2,5
-difluoroaniline, N) lyntylsilyl 2.4.
Examples include one or more compounds selected from 6-1-lifluoroaniline and the like.

The terminal modification method is as follows: 0.2 to 0.2 to the number of moles of the terminal acid anhydride in the acid anhydride terminal polyamic acid solution.
5.0 equivalents, preferably 0.5 to 3.0 equivalents, more preferably 0.8 to 2.0 equivalents of the compound that reacts with the above acid anhydride, is dissolved in a suitable solvent or added as is. , by stirring thoroughly. If the amount is less than this, the effect will not be sufficient, and if the amount is more than this, the mechanical properties will deteriorate. Excess molar amount of acid anhydride-terminated polyamic acid to diamine and diamine■
It can be obtained by reacting with an acid dianhydride.

The polyamic acid solution thus obtained is cast onto a support such as a glass plate in the form of a thin film, then this coating is dried, peeled off from the support, fixed on all sides, and placed in a heating oven. The polyimide film is dried by heating and subjected to ring closure by heating.

The polyimide film thus obtained showed extremely high alkali resistance.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited by these in any way.

Example 1 21.82g (0,100 mol) of pyromellitic dianhydride (hereinafter referred to as PMDA) was dissolved in 220g of dimethylformamide (hereinafter referred to as DMF), and the solution was
After cooling to 'c, diaminodiphenyl ether19.
82 g (0,099 mol) was added to obtain an acid anhydride-terminated polyamic acid. At this time, the viscosity of the polyamic acid solution is 3
000 boys (23'C). After stirring for 1 hour, 0
．． 333 g (0,003 mol) of parafluoroaniline was dissolved in 5 g of DMF and added to the polyamic acid solution. This polyamic acid solution was cast into a film and thermally cyclized using an imidizing agent to produce 25 tons! polyimide film. This polyimide film is made of 5% Na
When treated for 5 minutes at 50° C. in a 0Il aqueous solution, the weight n loss relative to the weight before treatment was 1.8%.

Example 2 21.82 g (0,100 mol) of l'MD8 was dissolved in 220 g of DMF, and after cooling the solution to -5°C, 19.82 g (0,0 mol) of diaminodiphenylether was dissolved.
99 mol) was added to obtain an acid anhydride-terminated polyamic acid.

At this time, the viscosity of the polyamic acid solution was 3000 voids (23
°C). After stirring for 1 hour, 0.549 g (0,
003 mol) of Il-trimethylsilylparafluoroaniline was dissolved in 5 g of DMF and added to the polyamic acid solution. This polyamic acid solution was cast into a film and thermally cyclized using an imidizing agent to form a 25 μm polyimide film.

This polyimide film was dissolved in a 5% Na0II aqueous solution for 50 min.
When treated at ℃ for 5 minutes, the weight loss was 1.0% with respect to the weight before treatment.

Example 3 15.02 g (0,075 mol) in 210 g DMF
After cooling, 21.82 g (0.100 mol) of II M D
A was added followed by 2.5 9 g (0.0 2
4 mol) of para-phenylene diamine was dissolved in 5 g of DMF and added to obtain an acid anhydride-terminated copolymerized polyamic acid.

At this time, the viscosity of the polyamic acid solution was 3000 voids (23
℃). After stirring for 1 hour, 0.549 g (0.
N-)limethylsilylparafluoroaniline (3 moles of O2) was dissolved in 5 g of DMF and added to the above polyamic acid solution to obtain an acid anhydride-terminated copolymerized polyamic acid.

This polyamic acid solution was cast into a film and thermally cyclized using an imidizing agent to form a 25 μm polyimide film. This polyimide film was diluted with 5% NaOH.
When treated in an aqueous solution at 50°C for 5 minutes, the weight loss was 4.5% relative to the weight before treatment.

Comparative Example 1 21.82 g (0,100 mol) of PMOA was
After dissolving in 0 g of DMF and cooling the solution to -5°C, 19.82 g of diaminodiphenyl ether (0,099
mol) was added. At this time, the viscosity of the polyamic acid solution is 3
000 voids (23°C). Is this polyamic acid?
The film was cast into four sizes and thermally cyclized using an imidizing agent to form a 25 μm polyimide film. This polyimide film was coated with 5% Na.01 (50°C in an aqueous solution).
When treated for 5 minutes, the weight reduction was 2.8% relative to the weight before treatment.

Comparative Example 2 15.02g (0,075 mol) in 210g DMF
diaminodiphenyl ether was dissolved, and after cooling to 0°C, 21.82 g (0,100 mol) of PMD^ was added,
Subsequently, 2.59 g (0,024 mol) of paraphenylenediamine dissolved in 5 g of DMF was added.

At this time, the viscosity of the polyamic acid solution was 3000 poise (23
℃). This polyamic acid solution was cast into a film and thermally cyclized using an imidizing agent to form a 25 μm polyimide film. 5% of this polyimide film
When treated in an aqueous NaOH solution at 50° C. for 5 minutes, the weight ff1X relative to the weight before treatment was 8.0%.

〔Effect of the invention〕

The present invention is an extremely useful method in that it is possible to obtain a polyimide film with excellent alkali resistance through terminal modification, and other physical properties are not significantly degraded. Therefore, it can be applied to various polyimides and has extremely wide industrial applicability.

Claims (1)

[Claims] 1. A polyimide film having a structure represented by ▼ where there is a mathematical formula, chemical formula, table, etc. at the end. (However, in the formula, R represents ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and X_1_ to _9 are each -H , -F, -Cl, -Br
, -OCH_3, -COOH, -CH_3, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -NH_2, -NO_2, -
(represents CN). 2. R is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas,
There are chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
The polyimide film according to claim 1, which has tables, etc. ▼, ▲ has mathematical formulas, chemical formulas, tables, etc. ▼. 3. The polyimide film according to claim 1, wherein the polyimide is a polyimide containing pyromellitic dianhydride, diaminodiphenyl ether, and/or paraphenylene diamine.