JP2004314394A - Method for manufacturing polyimide film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a polyimide film based on a 3,3',4,4'-biphenyltetracarboxylic acid component and p-phenylenediamine, high in productivity, causing no cloudiness and having good transparency. <P>SOLUTION: A solution is prepared by adding an imidating catalyst to a solution of a polyimide precursor, which is based on a 3,3'4,4'-biphenyltetracarboxylic dianhydride and p-phenylendiamine, in a polar organic solvent if necessary and cast on a support to be brought into contact with an alcohol being liquid at the normal temperature. Thereafter, the self-supporting film of polyamic acid peeled from the support is heated and dried to manufacture the imidated polyimide film. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００２６】
【発明の効果】
この発明は以上詳述したような構成を有しているため、以下のような効果を奏する。
すなわち、この発明の方法によれば、３，３’，４，４’−ビフェニルテトラカルボン酸成分とｐ−フェニレンジアミンとを主成分とし、生産性が高く、白濁せず透明性が良好なポリイミドフィルムを製造することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in a method for producing a polyimide film containing a 3,3 ′, 4,4′-biphenyltetracarboxylic acid component and p-phenylenediamine as main components.
[0002]
[Prior art]
Polyimide films are widely used for electronic devices because of their excellent thermal and electrical properties.
In particular, a polyimide film containing a 3,3 ′, 4,4′-biphenyltetracarboxylic acid component and p-phenylenediamine as main components has excellent dimensional stability, thermal properties and electrical properties. Widely used for applications such as displays.
[0003]
The polyimide film containing the 3,3 ′, 4,4′-biphenyltetracarboxylic acid component and p-phenylenediamine as the main components is obtained by casting a solution of a polyamic acid in a polar organic solvent on a support, followed by drying. To obtain a self-supporting film, followed by drying by heating and imidization. (Patent Document 1)
In this production method, a large amount of heat and time are required to remove a solvent having a high affinity for the polyimide precursor, and thus there is a problem that productivity is low.
For the purpose of improving this productivity, when a method of imidization using an imidization catalyst and a dehydrating agent such as acetic anhydride is applied to this polyimide system, a polyimide film having an extremely small linear expansion coefficient can be obtained. However, it is not practical due to the problem of odor and device corrosion caused by the dehydrating agent.
[0004]
Therefore, the present inventors tried to obtain a self-supporting polyimide precursor film by replacing the solvent by immersing the polyimide precursor polar organic solvent solution in a poor solvent, but tried to obtain a self-supporting polyimide precursor film. However, there was a problem that the turbidity became cloudy.
[0005]
[Patent Document 1]
Japanese Patent Publication No. 4-6213 [0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for producing a polyimide film which contains a 3,3 ', 4,4'-biphenyltetracarboxylic acid component and p-phenylenediamine as main components, has high productivity, is not cloudy, and has good transparency. It is to provide.
[0007]
[Means for Solving the Problems]
That is, the present invention relates to a method of adding an imidization catalyst to a polar organic solvent solution of a polyimide precursor containing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and p-phenylenediamine as main components. A method for producing a polyimide film, in which a solution obtained by casting the solution onto a support, contacting it with an alcohol which is a liquid at room temperature, and then heating and drying the self-supporting film of polyamic acid peeled from the support and imidizing it. Things.
[0008]
In the present invention, first, a solution obtained by adding an imidization catalyst to a polar organic solvent solution of a polyimide precursor containing a 3,3 ′, 4,4′-biphenyltetracarboxylic acid component and p-phenylenediamine as main components is used. Cast on a support.
[0009]
The polyimide precursor is preferably an aromatic tetracarboxylic dianhydride having a proportion of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride of 60 mol% or more, particularly 100 mol%. It is prepared from an aromatic diamine having a proportion of p-phenylenediamine of 50 mol% or more, particularly 100 mol%. In copolymerized or blended polyimide, pyromellitic dianhydride is used as an aromatic tetracarboxylic dianhydride other than 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, and p-phenylene is used. A three-component or four-component polyimide precursor using 4,4′-diaminodiphenyl ether as an aromatic diamine other than the diamine can also be used.
[0010]
Synthesis of the polyimide precursor is a random polymerization of substantially equimolar with the aromatic tetracarboxylic dianhydride and an aromatic diamine in an organic solvent, block polymerization, or two or more in advance either component is excessive This is achieved by any method of synthesizing a polyamic acid, mixing the respective polyamic acid solutions, and then mixing under a reaction condition.
[0011]
In addition, an imidizing agent can be added to the polyimide precursor (the organic polar solvent solution in the dope solution for the purpose of accelerating imidization. For example, imidazole, 2-imidazole, 1, 2-dimethylimidazole, 2-phenylimidazole, benzimidazole, isoquinoline, substituted pyridine and the like can be used at a ratio of 0.005 to 1 mol% with respect to the amic acid.
[0012]
Examples of the polar organic solvent for producing the above-mentioned polyimide precursor include N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide and the like. These organic solvents may be used alone or in combination of two or more.
[0013]
In the method of the present invention, after a polar organic solvent solution of a polyimide precursor is cast on a support (for example, a stainless steel substrate, a stainless steel belt, or a glass plate), the solution is brought into contact with an alcohol which is liquid at normal temperature. It is necessary to obtain a polyamic acid self-supporting film peeled from the support.
The polyimide precursor solution preferably has a polymer concentration of about 8 to 25% by weight.
The polyimide precursor polar organic solvent solution may be added with a known additive, for example, a necessary amount of an organic or inorganic filler.
[0014]
As the alcohol for immersing the cast of the polar organic solvent solution of the polyimide precursor, an aliphatic or alicyclic alcohol having 1 to 10 carbon atoms, preferably an aliphatic alcohol having 1 to 8 carbon atoms. Alcohols include, for example, methanol, ethanol, i-propanol, n-propanol, 1-butanol, t-butanol, 1-octanol and the like.
As a method of bringing the cast of the polar organic solvent solution of the polyimide precursor into contact with the alcohol, a method of spraying an alcohol on the cast of the polar organic solvent solution of the polyimide precursor, and Immersion of the casting in alcohol.
[0015]
The immersion in the above-mentioned alcohol is preferably performed at 10 to 50 ° C. for 1 to 10 minutes, particularly for about 3 to 10 minutes.
When the support is a rotating body such as a stainless steel belt, the dipping in the alcohol is preferably carried out by rotating the polyimide precursor coating material and passing it through a storage solution of alcohols. .
[0016]
In the present invention, the polyimide precursor self-supporting film is peeled from the support after dipping the polyimide precursor coating in alcohol.
Next, in the method of the present invention, it is preferable that both ends of the self-supporting film are gripped and heated to a maximum heating temperature in the range of 150 ° C. to 425 to 600 ° C.
[0017]
The polyimide film of the present invention has a tensile strength (ASTM D882, average of MD and TD, the same applies hereinafter) of 200 MPa or more, a tensile modulus of 4000 MPa or more, and a linear expansion coefficient (50 to 200 ° C.) of 5 to 30 ppm / ° C. Good transparency.
[0018]
Therefore, the polyimide film obtained by the method of the present invention is suitably used for a base film such as a metallized substrate by a lamination method or a metallized substrate by a sputtering method, or a base film of a metallized film. be able to. As a method of manufacturing the metal foil laminate, a known method, for example, a method described in “Printed Circuit Technology Handbook” (Nikkan Kogyo Shimbun, 1993) or the like is suitably applied.
[0019]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
In each of the following examples, a method for evaluating a film is shown below.
Tensile modulus: ASTM D882
Coefficient of tensile linear expansion (50 to 200 ° C.): measured with a micro linear dilatometer Film condition: It was visually observed whether it was transparent or cloudy.
[0020]
Example 1
3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine were reacted in dimethylacetamide (DMAc) to give a dope having a polyamic acid concentration of 18% by mass. 0.2 mole of 1,2-dimethylimidazole was added per mole. This dope was cast on a glass plate so as to have a thickness of 75 μm after heating, drying and imidization, and was immersed in methanol together with the glass plate, and then peeled from the glass plate. The obtained self-supporting film was gripped by a four-way tenter and continuously heated from 150 ° C. to 450 ° C. to complete the drying and imidization, thereby obtaining a polyimide film.
The results of evaluating the obtained polyimide film are shown below.
[0021]
Film thickness: 75 μm
Film state: Transparent tensile elasticity: 5000 MPa
Linear expansion coefficient (50-200 ° C): 9.09 ppm / ° C
[0022]
Examples 2 to 16
A polyimide film was obtained in the same manner as in Example 1, except that the type of alcohol to be immersed, the amount of 1,2-dimethylimidazole added, and the thickness of the film were changed.
Table 1 shows the results of evaluating the obtained polyimide film.
In the table, IPA means isopropanol, and BuOH means 1-butanol.
[0023]
Comparative Examples 1-3
A polyimide film was obtained in the same manner as in Example 1 except that the film was immersed in a solvent shown in Table 1 instead of alcohol.
Table 1 shows the results of evaluating the obtained polyimide film.
[0024]
Example 17, Comparative Example 4
Further, in Examples 1 to 16, it took 10 minutes to peel off after immersion in the alcohol, but when not immersed in the alcohol, the time required to peel off the self-supporting film from the glass substrate was Usually about 30 minutes.
Then, from the above examples, Examples 9, 10, 12, 13, and 14 were selected, and the shortest time until peeling after immersion in the alcohol was measured. 5 minutes, 5 minutes, 7 minutes, 3 minutes, 5 minutes.
[0025]
[Table 1]

[0026]
【The invention's effect】
Since the present invention has the configuration described in detail above, the following effects can be obtained.
That is, according to the method of the present invention, a polyimide which contains a 3,3 ', 4,4'-biphenyltetracarboxylic acid component and p-phenylenediamine as main components, has high productivity, is not cloudy, and has good transparency. Films can be manufactured.

Claims (1)

A solution prepared by adding an imidation catalyst to a polar organic solvent solution of a polyimide precursor containing 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine as main components is used as a support. A method for producing a polyimide film, comprising casting and then heating and drying a polyamic acid self-supporting film peeled from a support after contact with an alcohol which is liquid at room temperature, followed by imidization.