JP2000319392A - Polyimide film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject film which can exhibit both high elastic modulus and strong toughness (high elongation), by using a specific aromatic diamine component and a specified tetracarboxylic acid dianhydride component. SOLUTION: This polyimide film is obtained by reacting (A) (i) 4,4'- diaminophenyl ether and (ii) 4,4'-diaminobenzanilide as an aromatic diamine component with (B) (iii) 1,4-hydroxybenzoate-3,3',4,4'-tetracarboxylic acid dianhydride as a tetracarboxylic acid dianhydride component. The component i is preferably used in an amount of 50 to 85 mol.% based on the component A used for the reaction, and the component iii is preferably used in an amount of 15 to 45 mol.% based on the component B used for the reaction. The component B may, if necessary, further contain (iv) 3,3',4,4'-biphenyltetracarboxylic acid dianhydride. Thereby, the objective film which does extremely lower elastic modulus and can express strong toughness is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyimide film having both high elastic modulus and toughness.

[0002]

2. Description of the Related Art Polyimide films are used in a wide range of fields such as electronic materials and insulating materials because of their excellent heat resistance and electrical insulation. In recent years, especially for small electronic devices,
In order to meet the demand for thinner films, there is a strong demand for polyimide films having a high modulus of elasticity that can sufficiently withstand film thinning. Conventionally, 4,4 'has been used as a high modulus polyimide film.
A polyimide film using diaminobenzanilide is disclosed in JP-A-62-280224.

[0003]

However, the polyimide film disclosed in Japanese Patent Application Laid-Open No. 62-280224 has a high elastic modulus, but is brittle and cannot be put to practical use. Even that was difficult.

[0004]

In view of the above circumstances, the present inventors have solved the conventional problems and provided a polyimide film having both high elastic modulus and toughness (high elongation). We studied diligently for the purpose. As a result, 4,4'-diaminodiphenyl ether was used in addition to 4,4'-diaminobenzanilide as an aromatic diamine component, and 1,4 as a tetracarboxylic dianhydride component.
4-hydroquinone dibenzoate-3,3 ', 4,4'
-Tetracarboxylic dianhydride, or optionally 3,
The present invention has led to a polyimide film having a high elastic modulus and toughness (high elongation) obtained by using 3 ', 4,4'-biphenyltetracarboxylic dianhydride.

That is, a first aspect of the present invention is that 4,4'-diaminodiphenyl ether and 4,4'-diaminobenzanilide are used as aromatic diamine components and 1,4-hydroquinone dibenzoe-benzoate is used as a tetracarboxylic dianhydride component. (3) A polyimide film obtained by reacting 3,3 ', 4,4'-tetracarboxylic dianhydride. A second aspect of the present invention is that the aromatic diamine component is 4,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl ether.
4'-diaminobenzanilide was converted to 1,4-hydroquinone dibenzoate-3,3 ', 4,4'-tetracarboxylic dianhydride and 3,3', 4, as tetracarboxylic dianhydride components. A polyimide film obtained by reacting 4'-biphenyltetracarboxylic dianhydride is contained therein (claim 2). A third aspect of the present invention is the polyimide film according to claim 1 or 2, wherein 4,4′-diaminobenzanilide is 50 to 85 mol% of the aromatic diamine component used in the reaction. ). A fourth aspect of the present invention is to provide 1,4-hydroquinone dibenzoate-3,
The polyimide film according to claim 2 or 3, wherein 3 ', 4,4'-tetracarboxylic dianhydride is 15 to 45 mol% of the tetracarboxylic dianhydride component used in the reaction. Item 4).

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyimide film of the present invention
It is characterized by being obtained by reacting a specific aromatic diamine component with a tetracarboxylic dianhydride component, and has both high elastic modulus and toughness.

The high elastic modulus of the present invention means that the elastic modulus of the film in a tensile test is 650 kg / mm ² or more, preferably 900 kg / mm ² or more. Is 5% or more, preferably 10% or more, and more preferably 15% or more. When the elastic modulus is low, when the thickness of the film is reduced to less than 10 μm, the hardness of the film becomes insufficient and the film cannot be used as a base film. In addition, films with low elongation and poor toughness tend to crack or break the film and cannot be used practically as base films for flexible printed circuit boards or recording media, and it is also difficult to obtain long films. is there.

The specific aromatic diamine component referred to in the present invention is 4,4'-diaminodiphenyl ether (hereinafter referred to as ODA) represented by the following chemical formula (1):

[0009]

Embedded image And 4,4'-diaminobenzanilide (hereinafter referred to as DABA) represented by the following chemical formula (2),

[0010]

Embedded image DABA is preferably used in a ratio of 50 to 85 mol% based on the total aromatic diamine component. This is because a more remarkable effect of improving the elastic modulus is exhibited at 50 mol% or more, and a more remarkable effect of improving the elongation is observed at 85 mol% or less. The specific tetracarboxylic dianhydride component is 1,4-hydroquinone dibenzoate-3,3 ', 4,4'-tetracarboxylic dianhydride (hereinafter referred to as TMHQ) represented by the following chemical formula (3). ), And

[0011]

Embedded image The use of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (hereinafter referred to as BPDA) represented by the following chemical formula (4) as a tetracarboxylic dianhydride component is further

[0012]

Embedded image It is preferable for obtaining a polyimide film having high elasticity and toughness. In this case, the amount of TMHQ used is preferably 15 to 45 mol% of the total tetracarboxylic dianhydride component.

Next, the method for producing a polyimide film according to the present invention will be specifically described. The polyimide film of the present invention has a precursor represented by the general formula (5)

[0014]

Embedded image (Wherein R ₁ represents a tetravalent organic group and R ₂ represents a divalent organic group). The polyamic acid solution is obtained by a known method. Can be manufactured. That is, it is obtained by polymerizing tetracarboxylic dianhydrides and aromatic diamines in an organic polar solvent using substantially equimolar amounts. The polyamic acid according to the present invention is obtained by first reacting an equimolar tetracarboxylic dianhydride with a solution containing only DABA as an aromatic diamine component to obtain a polyamic acid-containing solution, and dissolving ODA in the same reaction solution. And the same or different tetracarboxylic dianhydrides are reacted.

The tetracarboxylic dianhydrides used in the present invention are TMHQ and BPDA. By using TMHQ, a film having a high elastic modulus and toughness can be obtained.

The aromatic diamines are DABA and ODA. Particularly, DABA is preferably used as a main component from the viewpoint of a high elastic modulus.

The organic solvent used for the polyamic acid formation reaction includes sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, and formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide. , Acetamide solvents such as N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, N-vinyl-2-
Pyrrolidone solvents such as pyrrolidone, phenol, o-,
Phenol-based solvents such as m- or p-cresol may be used, and these may be used alone or as a mixture. It is also possible to use aromatic hydrocarbons such as xylene and toluene. The polyamic acid is preferably dissolved in the organic solvent in an amount of 1 to 40% by weight, preferably 5 to 25% by weight, from the viewpoint of handling.

The length of the molecular chain of the polyamic acid after polymerization is as follows:
It is preferable that the weight average molecular weight is 100,000 or more, irrespective of the constitution of the molecular chain. When the weight average molecular weight is less than 100,000, a film having poor toughness tends to be formed.

In order to obtain the polyimide film of the present invention from the polyamic acid solution, any of (1) a thermal method of thermally dehydrating and imidizing and (2) a chemical method using a dehydrating agent may be used. However, it is more preferable to use a chemical method that can easily obtain a film having excellent mechanical properties such as elongation and strength.

Hereinafter, a method for producing a film from a polyamic acid solution will be exemplified. (1) The above polyamic acid solution is cast or coated on a drum or an endless belt to form a film, and the film is formed into a film until it has a self-supporting property.
Dry at a temperature below ℃ for about 5-60 minutes. Then, after peeling it off from the support and fixing the end, drying and imidization are performed by gradually heating the film to about 100 ° C. to 500 ° C. while restricting the shrinkage of the film, and after cooling, the fixing is removed to remove the film. Obtain a polyimide film.

In the above production method, a mixed solution of a polyamic acid solution and a release agent may be used in place of the polyamic acid solution in order to easily peel the self-supporting film from the support. When a polyimide film is obtained by a chemical method, a mixed solution obtained by adding a dehydrating agent having a stoichiometric amount or more and a catalytic amount of a tertiary amine to a polyamic acid solution may be used instead of the polyamic acid solution.

Examples of the releasing agent include aliphatic ethers such as diethylene glycol dimethyl ether and triethylene glycol dimethyl ether, tertiary amines such as pyridine and picoline, triphenylphosphine and triphenyl. Organic phosphorus compounds such as phosphates are exemplified.

As the dehydrating agent, for example, acetic anhydride,
Examples thereof include aliphatic or aromatic acid anhydrides such as phthalic anhydride. Examples of the catalyst include aliphatic tertiary amines such as triethylamine, and heterocyclic tertiary amines such as pyridine, picoline and isoquinoline.

Further, when the film is dried or imidized, it may be stretched. This is because a film having excellent mechanical properties can be easily obtained by stretching.

For the purpose of improving various properties such as adhesion, heat resistance, and slipperiness of the film, the film may contain fine particles such as titanium oxide, calcium carbonate, alumina, silica gel, etc. The surface may be coated with a surface modifier such as a silane coupling agent or a solution containing fine particles and a binder resin, or subjected to a discharge treatment such as a corona treatment or a plasma treatment.

[0026]

Next, examples of the present invention will be described in more detail, but the present invention is not limited only to these examples.

In the examples, DABA is 4,4'-diaminobenzanilide, ODA is 4,4'-diaminodiphenyl ether, TMHQ is 1,4-hydroquinonedibenzoate-3.3 ', 4. , 4'-tetracarboxylic dianhydride, BPDA represents 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, NMP represents N-methyl-2-pyrrolidone, and DMAC represents dimethylacetamide.

(Example 1) At 40 ° C to 50 ° C, DABA13 was placed in a three-neck separable flask equipped with a stirrer.
6.2 g (0.6 mol) and 3185.1 g of NMP were charged to prepare an aromatic diamine solution. 173.5 g (0.59 mol) of BPDA powder was added to the obtained solution, and the mixture was stirred for 30 hours in a nitrogen atmosphere. Next, 80.0 g (0.4 mol) of ODA was added to this solution, followed by 183.2 g (0.4 mol) of TMHQ, and the mixture was further stirred for 1 hour. 4.6 g of TMHQ was added to the obtained solution.
(0.01 mol) was dissolved in 87.4 g of NMP, and the mixture was stirred for 1 hour to obtain a polyamic acid solution.

A polyimide film was prepared from the polyamic acid solution obtained by the above operation by a chemical method. The production of the film is performed as follows. 100
g of polyamic acid solution, 15 g of acetic anhydride, 3 g of isoquinoline, and 10 g of NMP were added, and the mixture was sufficiently stirred.
For 2 minutes to obtain a film having self-supporting properties. After peeling this film from the PET film, fix the end and
It heated continuously from 20 degreeC to 380 degreeC over 20 minutes, and also heated at 450 degreeC for 1 minute, and obtained the 10-micrometer-thick polyimide film.

Using the obtained film, a tensile test was performed by AST.
According to the method of MD-882, the elastic modulus and the elongation of the film were measured, and the measurement results of the elastic modulus of 905 kg / mm ² and the elongation of 21% were obtained. Table 1 shows the polymerization recipe and the measurement results.

Example 2 At 40 ° C. to 50 ° C., DABA13 was placed in a three-neck separable flask equipped with a stirrer.
6.2 g (0.6 mol) and 3733.1 g of NMP were charged to prepare an aromatic diamine solution. T
270.2 g (0.59 mol) of MHQ powder was added, and the mixture was stirred in a nitrogen atmosphere for 30 hours. Next, 80.0 g (0.4 mol) of ODA was added to this solution, followed by 183.2 g (0.4 mol) of TMHQ, and the mixture was further stirred for 1 hour. 4.6 g of TMHQ was added to the obtained solution.
(0.01 mol) was dissolved in 87.4 g of NMP, and the mixture was stirred for 1 hour to obtain a polyamic acid solution.

A polyimide film having a thickness of 10 μm was obtained in the same manner as in Example 1 from the polyamic acid solution obtained by the above operation.

Using the obtained film, a tensile test was performed by AST.
According to the method of MD-882, the elastic modulus and the elongation of the film were measured, and the measurement results of the elastic modulus of 970 kg / mm ² and the elongation of 12% were obtained. Table 1 shows the polymerization recipe and the measurement results.

Example 3 At 40 ° C. to 50 ° C., DABA18 was placed in a three-neck separable flask equipped with a stirrer.
1.6 g (0.80 mol) of NMP 2951.5 g
Was added to prepare an aromatic diamine solution. 229.3 g (0.78 mol) of BPDA powder was added to the obtained solution, and the mixture was stirred for 30 hours in a nitrogen atmosphere. Next, 40.0 g (0.2 mol) of ODA was added to this solution, followed by 91.6 g (0.20 mol) of TMHQ, and the mixture was further stirred for 1 hour. 9.2 g of TMHQ was added to the obtained solution.
(0.02 mol) was added to a solution obtained by dissolving 174.8 g of NMP, followed by stirring for 1 hour to obtain a polyamic acid solution.

From the polyamic acid solution obtained by the above operation, a polyimide film having a thickness of 10 μm was obtained in the same manner as in Example 1.

Using the obtained film, a tensile test was performed by AST.
According to the method of MD-882, the elastic modulus and elongation of the film were measured, and a measurement result of an elastic modulus of 950 kg / mm ² and an elongation of 19% was obtained. Table 1 shows the polymerization recipe and the measurement results.

(Example 4) At 40 ° C to 50 ° C, DABA68. Was placed in a three-neck separable flask equipped with a stirrer.
1 g (0.30 mol) and 3687.2 g of NMP were charged to prepare an aromatic diamine solution. T
132.8 g (0.29 mol) of MHQ powder was added,
The mixture was stirred in a nitrogen atmosphere for 30 hours. The solution was then added with O
140.0 g (0.70 mol) of DA was added, followed by 320.6 g (0.70 mol) of TMHQ, and the mixture was further stirred for 1 hour. 4.6 g of TMHQ was added to the obtained solution.
(0.01 mol) was added to a solution obtained by dissolving 87.4 g of NMP, followed by stirring for 1 hour to obtain a polyamic acid solution.

Using the obtained polyamic acid solution, a polyimide film was obtained in the same manner as in Example 1, and the elastic modulus and elongation were measured. As a result, a measurement result of 710 kg / mm ^{2 of} elasticity and 24% of elongation was obtained. . Table 1 shows the polymerization recipe and the measurement results.

Example 5 At 40 ° C. to 50 ° C., DABA20 was placed in a three-neck separable flask equipped with a stirrer.
4.3 g (0.90 mol) and 2873.9 g of NMP
Was added to prepare an aromatic diamine solution. 258.7 g (0.88 mol) of BPDA powder was added to the obtained solution, and the mixture was stirred for 30 hours in a nitrogen atmosphere. Next, 20.0 g (0.10 mol) of ODA was added to this solution, followed by 45.8 g (0.10 mol) of TMHQ, and the mixture was further stirred for 1 hour.

9.2 g of TMHQ (0.
02mol) was added to 174.8 g of NMP, and the mixture was stirred for 1 hour to obtain a polyamic acid solution. Using the obtained polyamic acid solution, a polyimide film was obtained in the same manner as in Example 1, the elastic modulus and the elongation were measured, and the measurement results of the elastic modulus of 1105 kg / mm ² and the elongation of 5% were obtained. Table 1 shows the polymerization recipe and the measurement results.

Comparative Example 1 At 40 ° C. to 50 ° C., DABA22 was placed in a three-neck separable flask equipped with a stirrer.
7.3 g (1.0 mol) and 3733.1 g of NMP were charged to prepare an aromatic diamine solution. B in the resulting solution
288.3 g (0.98 mol) of powder of PDA was added, and the mixture was stirred for 30 hours in a nitrogen atmosphere. B in the resulting solution
5.9 g (0.02 mol) of PDA was added to NMP 17
After adding a solution obtained by dissolving 4.8 g, the mixture was stirred for 1 hour to obtain a polyamic acid solution.

A polyimide film having a thickness of 10 μm was obtained from the polyamic acid solution obtained by the above operation in the same manner as in Example 1.

Using the obtained film, a tensile test was performed by AST.
According to the method of MD-882, the elastic modulus and the elongation of the film were measured, and the measurement results of the elastic modulus of 1200 kg / mm ² and the elongation of 3% were obtained. Table 1 shows the polymerization recipe and the measurement results.

(Comparative Example 2) At 40 ° C to 50 ° C, DABA17 was placed in a three-neck separable flask equipped with a stirrer.
0.4 g (0.75 mol) and 3733.1 g of NMP were charged to prepare an aromatic diamine solution. 159.2 g (0.73 mol) of PMDA powder was added to the obtained solution, and the mixture was stirred in a nitrogen atmosphere for 30 hours. Next, 50.1 g (0.25 mol) of ODA was added to this solution, followed by 73.6 g (0.25 mol) of BPDA, and the mixture was further stirred for 1 hour. 5.9 g of BPDA was added to the obtained solution.
(0.02 mol) was added to a solution obtained by dissolving 174.8 g of NMP, followed by stirring for 1 hour to obtain a polyamic acid solution.

From the polyamic acid solution obtained by the above operation, a polyimide film having a thickness of 10 μm was obtained in the same manner as in Example 1.

Using the obtained film, a tensile test was performed by AST.
According to the method of MD-882, the elastic modulus and the elongation of the film were measured, and the measurement results of the elastic modulus of 1005 kg / mm ² and the elongation of 2% were obtained. Table 1 shows the polymerization recipe and the measurement results.

Comparative Example 3 DABA11 was placed in a three-neck separable flask equipped with a stirrer at 40 ° C. to 50 ° C.
3.6 g (0.5 mol) and 3733.1 g of NMP were charged to prepare an aromatic diamine solution. B in the resulting solution
144.2 g (0.49 mol) of PDA powder was added, and the mixture was stirred for 30 hours in a nitrogen atmosphere. Next, 100.1 g (0.5 mol) of ODA was added to this solution, followed by 147.1 g (0.5 mol) of BPDA, and the mixture was further stirred for 1 hour. BPDA 2.9 was added to the resulting solution.
g (0.01 mol) was dissolved in 87.4 g of NMP, and the mixture was stirred for 1 hour to obtain a polyamic acid solution.

From the polyamic acid solution obtained by the above operation, a polyimide film having a thickness of 10 μm was obtained in the same manner as in Example 1. Using the obtained film, a tensile test was performed according to the method of ASTM D-882, and the elastic modulus and elongation of the film were measured, and the elastic modulus was 593 kg / mm ² ,
A measurement result with an elongation of 18% was obtained. Table 1 shows the polymerization recipe and the measurement results.

[0049]

[Table 1]

[0050]

As described above, the polyimide film according to the present invention exhibits toughness without an extreme decrease in elastic modulus.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F071 AA60 AF20 AF39 AF45 BA02 BB02 BC01 4J002 CM041 FD010 4J043 PA04 QB15 QB26 QB31 RA34 SA06 SB03 TA14 TA22 TB03 UA131 UA132 UA142 UB121 UB162 UB221 ZA31 ZA32 ZB11

Claims (4)

[Claims] (1) 4,4'-diaminodiphenyl ether and 4,4'-diaminobenzanilide as an aromatic diamine component and 1,4 as a tetracarboxylic dianhydride component;
4-hydroquinone dibenzoate-3,3 ', 4,4'
-A polyimide film obtained by reacting tetracarboxylic dianhydride. (2) 4,4'-diaminodiphenyl ether and 4,4'-diaminobenzanilide as an aromatic diamine component and 1,4 as a tetracarboxylic dianhydride component.
4-hydroquinone dibenzoate-3,3 ', 4,4'
-Tetracarboxylic dianhydride and 3,3 ', 4,4'-
A polyimide film obtained by reacting biphenyltetracarboxylic dianhydride. 3. The polyimide film according to claim 1, wherein 4,4′-diaminobenzanilide is 50 to 85 mol% of the aromatic diamine component used in the reaction. 4. A 1,4-hydroquinone dibenzoate.
3,3 ', 4,4'-Tetracarboxylic dianhydride is a component of the tetracarboxylic dianhydride component used in the reaction.
The polyimide film according to claim 2, which is mol%.