JP3528236B2 - Roughened polyimide film and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a uniformly roughened polyimide film having excellent slipperiness and adhesiveness while maintaining mechanical strength and heat resistance, and a method for producing the same.

[0002]

2. Description of the Related Art Polyimide films are known to have various excellent properties such as heat resistance, abrasion resistance, chemical resistance, electrical properties and mechanical properties. Widely used for heat insulating films, base films for flexible printed wiring boards, etc.

Usually, these polyimide films are heat-treated by casting a polyamic acid solution, which is a polyimide precursor, on a support (metal, glass, plastic, etc.) and in air or an inert gas atmosphere or under reduced pressure. It is produced by subjecting it to dehydration and solvent removal.

However, the film obtained by this method has an extremely smooth surface and is extremely inferior in slipperiness, which is one of the important practical properties when it is used in the above-mentioned applications, and therefore, it can be used in various winding and unwinding processes. In the film manufacturing and processing process, due to the adhesion between the metal and the film, the adhesion of the films, etc.
There were major problems such as surface defects on the film.

Conventionally, as a method of improving the slipperiness of a film, a method of roughening the film surface has been known,
This method also leads to an improvement in the adhesiveness with a metal such as plastic or copper foil via an adhesive.

As one of the methods for roughening the surface of the film, there is a method of adding inorganic fine particles to the raw material solution (Japanese Patent Laid-Open No. 61-246919 and Japanese Patent Laid-Open No. 62-6885).
No. 3). This method certainly improves slipperiness,
It was difficult to make uniform unevenness due to sedimentation and aggregation of the inorganic fine particles.

Besides the method of plasma-treating the surface of the polyimide film (Japanese Patent Laid-Open No. 4-345630), sand plast treatment, corona treatment and the like are also known. In these methods, a new method is used after the film is produced. Since it is necessary to provide a process, it cannot be said to be advantageous from an economical viewpoint.

[0008]

DISCLOSURE OF THE INVENTION The present invention proposes a novel and useful method for roughening the surface of a polyimide film more simply, and provides a roughened polyimide film excellent in slipperiness and adhesiveness. The purpose is to

[0009]

Means for Solving the Problems As a result of intensive investigations by the present inventors to propose a surface-roughened polyimide film that can achieve such a problem, a polyimide solution and a polyamic acid solution as a polyimide precursor are mixed. A baked film prepared from an emulsion obtained by stirring has a uniformly roughened surface, and the roughened film has excellent slipperiness and adhesiveness. The present invention has been completed and the present invention has been completed based on such findings.

That is, in the method for producing a roughened polyimide film according to the present invention, a mixture containing an organic solvent-soluble aromatic polyimide, a polyamic acid and an organic solvent is cast, followed by dehydration and solvent removal. It is characterized by

The fact that the surface of the polyimide film is roughened by such a method is due to the fact that, during the film formation, the film formation process of the polyimide component accompanied only by desolvation and the polyamic acid component accompanied by dehydration (generation of water) It is assumed that this is due to differences in temperature, solvent and water volatilization rate).

As the organic solvent-soluble aromatic polyimide, an organic solvent-soluble aromatic polyimide is represented by the general formula (1):
An aromatic polyimide having a repeating unit represented by

[0013] [In the formula, A is a single bond, —SO ₂ —, —CO—, —O—,
Or _{-C (-CF 3) (- CF} 3) - represents a. Z is −
S- represents a group represented by the formula a, a group represented by the formula b, or a group represented by the general formula c. m represents a positive number. ]

[0014]

[0015]

[0016] [In the formula, X is -O-, -S- or -C (-R ¹ ) (-
R ²⁾ -, Y represents a single bond, -O -, - S -, - C
It represents a divalent group selected from (-R ¹ ) (-R ² )-or -CO-. R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom.

More specifically, 3,3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride (DSD)
A) polyimide prepared using A) as an acid component (for example, JP-A-64-121 and JP-A-3-160025),
A polyimide prepared using 3,3 ′, 4,4′-benzophenone tetracarboxylic acid dianhydride (BTDA) as an acid component (for example, JP-B-47-26878 and JP-A-61-61).
No. 19634) and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) as an acid component (for example, JP-A-50-11359).
7, JP-A-60-40131), a polyimide prepared using bis (3,4-dicarboxyphenyl) ether dianhydride (ODPA) as an acid component, 2,2-bis (3,4-). A polyimide prepared by using dicarboxyphenyl) hexafluoropropane dianhydride (6FDA) as an acid component (for example, JP-A-3-126779, J. Appl. P.
olym.Sci., 43 , 1-10 (1991)), and a polyimide prepared by applying a p, p'-diamino compound (see, for example, JP-A-61-2).
Examples include various polyimides such as 8526 and JP-A-61-2123634.

Specific examples of the acid component and the diamine component for obtaining the above organic solvent-soluble polyimide are as follows. The acid component and the diamine component may be used either individually or in combination of two or more kinds.

As the acid component, 3,3 ', 4,4'-diphenylsulfone tetracarboxylic acid dianhydride, 3,3'
3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 2 , 2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride and the like, and one or more compounds thereof.

The following compounds are exemplified as the diamine component. 4,4'-diaminodiphenyl sulfide,
2,2-bis [4- (p-aminophenoxy) phenyl] propane, 2,2-bis [3- (p-aminophenoxy) phenyl] propane, 2,2-bis [4- (p-
Aminophenyl thioether) phenyl] propane,
2,2-bis [3- (p-aminophenylthioether) phenyl] propane, 4,4'-bis (p-aminophenoxy) diphenylsulfone, 3,3'-bis (p
-Aminophenoxy) diphenyl sulfone, 3,4'-
Bis (p-aminophenoxy) diphenyl sulfone,
4,4'-bis (p-aminophenoxy) diphenyl ether, 3,3'-bis (p-aminophenoxy) diphenyl ether, 3,4'-bis (p-aminophenoxy) diphenyl ether, 4,4'-bis (p -Aminophenoxy) diphenyl sulfide, 3,3'-bis (p-aminophenoxy) diphenyl sulfide, 3,
4'-bis (p-aminophenoxy) diphenyl sulfide, 4,4'-bis (p-aminophenyl thioether) diphenyl sulfone, 3,3'-bis (p-aminophenyl thioether) diphenyl sulfone, 3,4 '
-Bis (p-aminophenyl thioether) diphenyl sulfone, 4,4'-bis (p-aminophenyl thioether) diphenyl ether, 3,3'-bis (p-aminophenyl thioether) diphenyl ether, 3,
4'-bis (p-aminophenyl thioether) diphenyl ether, 4,4'-bis (p-aminophenyl thioether) diphenyl sulfide, 3,3'-bis (p-aminophenyl thioether) diphenyl sulfide, 3,4'- Bis (p-aminophenyl thioether) diphenyl sulfide, 4,4'-bis (p-aminophenoxy) diphenyl, 3,3'-bis (p-aminophenoxy) diphenyl, 3,4'-bis (p-aminophenoxy) ) Diphenyl, 4,4'-bis (p-aminophenoxy) benzophenone, 3,3'-bis (p-
Aminophenoxy) benzophenone, 3,4'-bis (p-aminophenoxy) benzophenone, 4,4'-
Bis (p-aminophenyl thioether) diphenyl,
3,3'-bis (p-aminophenyl thioether) diphenyl, 3,4'-bis (p-aminophenyl thioether) diphenyl, 4,4'-bis (p-aminophenyl thioether) benzophenone, 3,3'- Bis (p-aminophenylthioether) benzophenone,
3,4'-bis (p-aminophenylthioether) benzophenone, 1,4-bis (p-aminophenylthioether) benzene, 1,3-bis (p-aminophenylthioether) benzene, 4,4 '-(p -Phenylenediisopropylidene) dianiline, 4,4 '-(m-
Phenylene diisopropylidene) dianiline, 2,2-
Bis [4- (p-aminophenoxy) phenyl] hexafluoropropane.

Of course, in the present invention, other aromatic tetracarboxylic acids and diamines may be used in combination as long as the obtained polyimide is soluble in an organic solvent.

Examples of other aromatic tetracarboxylic acids that can be used in combination include pyromellitic dianhydride and naphthalenetetracarboxylic dianhydride.

Other diamines that can be used include
4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane,
3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone,
3,3'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-
Diaminodiphenyl, 3,4'-diaminodiphenyl,
Examples include 3,3′-diaminodiphenyl, m-phenylenediamine, p-phenylenediamine and the like.

In the present invention, the organic solvent-soluble polyimide is a polyimide obtained by combining the above-mentioned acid component and diamine component, etc., with N, N-dimethylacetamide, N, N-dimethylformamide and N-methyl-2. -Pyrrolidone, dimethylsulfoxide, phenol, cresol, chlorophenol, γ-butyrolactone, bis (2-methoxyethyl) ether, tetrahydrofuran, 1,3-dioxane, and 1,4-dioxane or dichloromethane at room temperature. Is a resin that can be dissolved at a resin concentration of 1% by weight or more, preferably 5% by weight or more.

Among the various polyimides mentioned above, especially DSDA
A polyimide prepared by using as an acid component is useful. This means that the polyimide prepared using ODPA as an acid component tends to be slightly lacking in heat resistance, and the polyimide prepared using BTDA as an acid component has a problem in storage stability in a solution. In addition, for polyimide prepared using BPDA as an acid component, the soluble organic solvent is significantly limited. This is because polyimide prepared using 6FDA as an acid component has problems such as lack of economy because 6FDA is expensive.

As the polyamic acid according to the present invention, a polyamic acid having a repeating unit represented by the general formula (2) is recommended.

[0027] [In the formula, R ³ represents a tetravalent organic group, and R ⁴ represents a divalent organic group. ]

As particularly recommended polyamic acid, in addition to various polyamic acids which are the precursors of the above aromatic polyimide, polyamic acid prepared by using pyromellitic dianhydride (PMDA) as an acid component, 4,4 ′ Examples thereof include polyamic acid prepared by using diaminodiphenyl ether (DDE) as a diamine component.

Among the above-mentioned combinations of aromatic polyimide and polyamic acid, the following combinations are particularly recommended.

(1) In the case of a combination of a polyimide prepared using DSDA as an acid component and a polyamic acid which is a precursor thereof, it is produced under industrially advantageous conditions and is excellent in economic efficiency.

(2) In the case of a combination of a polyimide prepared using DSDA as an acid component and a polyamic acid prepared from PMDA and DDE, a roughened film having high heat resistance can be obtained.

In the present invention, the blending amount of the polyimide component (A) and the polyamic acid component (B) is A / B = 90-
10/10 to 90 parts by weight is preferable, and A / B = 75 to 2
5/25 to 75 are more preferable. When the compounding ratio is out of this range, it tends to be a smooth film, and it is difficult to obtain the effects of the present invention.

The polyimide component (A) does not necessarily have to be completely imidized, and the imidization ratio of polyamic acid may be 50% or more. When the imidization ratio is 50% or less, the mixed solution with the polyamic acid (B) does not appear as an emulsion and becomes uniform, and the roughened film, which is the object of the present invention, may not be obtained. In addition, the polyamic acid component (B) may be partially imidized as long as the imidization ratio is less than 50% within the range of solvent solubility.

The mixing method of each component according to the present invention is not particularly limited, but among them, a method in which each component is individually dissolved in a predetermined organic solvent is mixed and stirred, or an acid raw material is used in a polyimide solution. A method of synthesizing a polyamic acid component from a diamine raw material is recommended.

The organic solvent that can be used in the present invention is particularly limited as long as the individual components are dissolved and the solution after mixing and stirring becomes an emulsion in appearance and becomes an opaque or slightly turbid liquid in appearance. For example, N, N-dimethylacetamide (DMA
c), N, N-dimethylformamide, N-methyl-2
-Aprotic polar solvents such as pyrrolidone (NMP) and dimethyl sulfoxide, phenolic solvents such as phenol, cresol and chlorophenol, lactone solvents such as γ-butyrolactone, bis (2-methoxyethyl) ether, tetrahydrofuran, 1, 3-dioxane, 1,
Examples include ether solvents such as 4-dioxane. Of these, aprotic polar solvents are particularly suitable.

The amount of the organic solvent applied is usually 1 as the total amount of the polyimide component (A) and the polyamic acid component (B).
It is in the range of 100 to 2,000 parts by weight, and more preferably in the range of 300 to 1,000 parts by weight, relative to 00 parts by weight.

When the applied amount of the organic solvent is less than this range, the viscosity of the mixed solution is high and the workability is poor, and when it exceeds this range, a predetermined effect cannot be obtained.

The film forming conditions for obtaining a roughened film from the mixture do not require any special condition control, and general conditions for obtaining a polyimide film from a polyamic acid solution or a polyimide solution are applied.

For example, the mixed emulsion solution is glass,
After uniformly casting on a support such as metal or plastic using a knife coater, a rotary coater or the like, dehydration and solvent removal are performed.

The dehydration and desolvation methods include 150 to 35 in air or an inert gas atmosphere or under reduced pressure.
Examples thereof include a method of heating at 0 ° C., preferably 200 to 300 ° C., a method of ring-closing the polyamic acid component with a dehydrating ring-closing agent such as acetic anhydride, and a method of heating to remove the solvent.

The roughened film according to the present invention has heat resistance,
While retaining the excellent properties originally possessed by these polyimides such as mechanical properties, slipperiness and adhesiveness have been improved,
As electric insulation film, heat insulation film, protective film, base film for flexible printed wiring boards, etc.
Further, it is also useful as a part of a multi-layer structure requiring adhesion between materials.

[0042]

EXAMPLES The present invention will be described in more detail below with reference to examples. The methods for measuring the physical properties in the examples are as follows.

(A) Tensile strength, elongation at break It was based on the method of JIS K7127 (25 ° C).

(B) Glossiness A 60 ° specular glossiness was measured according to the method of JIS K 7105.

(C) Average roughness The centerline average roughness (Ra) was measured by an electron beam three-dimensional roughness analyzer (ELIONIX EPA-8000).

Preparation of polyimide solution

Production Example 1 4,4'-bis (p-aminophenoxy) diphenyl sulfone (BAPS) 43.25 g was placed in a 1 liter reactor equipped with a thermometer, a stirrer, a cooling tube and a nitrogen introducing tube.
(0.100 mol) and 362 g of NMP were charged, and BAPS was dissolved at room temperature in a nitrogen atmosphere. Then DS
After adding 35.80 g (0.10 mol) of DA, 170 ° C
React for 7 hours at room temperature to obtain a transparent and viscous polyimide solution (A
1) was obtained.

Production Example 2 2,2-bis [4- (p-aminophenoxy) phenyl] propane (BAPP) 4 was placed in the same reactor as in Production Example 1.
1.05 g (0.10 mol) and 352 g of DMAc were charged, and BAPP was dissolved at room temperature in a nitrogen atmosphere. Next, after adding 35.80 g (0.10 mol) of DSDA,
The reaction was carried out at 70 ° C. for 7 hours to obtain a transparent and viscous polyimide solution (A2).

Production Example 3 In the same reactor as in Production Example 1, 28.74 g (0.
07 mol), DDE 6.00 g (0.03 mol) and N
Charge MP301g, BAPP at room temperature under nitrogen atmosphere
And DDE was dissolved. Then ODPA31.00g
After adding (0.10 mol), the reaction product water was extracted at 170 ° C. for 7 hours to obtain a transparent and viscous polyimide solution (A3).

Production Example 4 BAPS 43.25 g (0.
(10 mol) and NMP (337 g) were charged, and BAPS was dissolved at room temperature in a nitrogen atmosphere. Next, BTDA16.
10 g (0.05 mol) and 14.70 g BPDA
After adding (0.05 mol), the reaction product water was extracted at 170 ° C. for 7 hours to obtain a transparent and viscous polyimide solution (A4).

Preparation of Polyamic Acid Solution

Production Example 5 43.25 g of BAPS (0.
10 mol) and NMP362 g were charged, and BAPS was dissolved at room temperature in a nitrogen atmosphere. Next, DSDA35.
80 g (0.10 mol) was gradually added, and the mixture was cooled to room temperature below 5
Clear and viscous polyamic acid solution (B1)
Got

Production Example 6 A reactor similar to that in Production Example 1 was charged with 41.05 g of BAPP (0.
10 mol) and DMAc (352 g) were charged, and BAPP was dissolved at room temperature in a nitrogen atmosphere. Next, DSDA35.
80 g (0.10 mol) was gradually added, and the mixture was cooled to room temperature below 5
Clear and viscous polyamic acid solution (B2)
Got

Production Example 7 In the same reactor as in Production Example 1, 20.00 g (0.1
0 mol) and NMP256g were charged, and under a nitrogen atmosphere,
The DDE was dissolved at room temperature. Next, DSDA 35.80g
(0.10 mol) was gradually added and reacted at room temperature for 5 hours to obtain a transparent and viscous polyamic acid solution (B3).

Production Example 8 20.00 g (0.1%) of DDE was placed in the same reactor as in Production Example 1.
0 mol) and 188 g of DMAc were charged, and DDE was dissolved at room temperature in a nitrogen atmosphere. Then PMDA 21.8
0 g (0.10 mol) was gradually added and reacted at room temperature for 5 hours to obtain a transparent viscous polyamic acid solution (B4).

Example 1 25 g of each of the polyimide solution (A1) and the polyamic acid solution (B1) were placed in a 100 ml glass bottle and stirred at room temperature for 3 hours with a seesaw rotary rotor to obtain an emulsified mixed solution in appearance. It was The obtained solution was cast on a glass plate with a spin coater and placed in a ventilated oven at 25 ° C.
The film was baked at 0 ° C. for 30 minutes to obtain a one-sided roughened film, and the glossiness, average roughness, tensile strength and breaking elongation of this film were measured. The results obtained are shown in Table 1. The appearance of the film was rough.

Examples 2 to 12 Polyimide solutions obtained in Production Examples 1 to 4 and Production Examples 5 to 8
A mixture prepared by emulsifying various polyamic acid solutions obtained in 1 above was prepared, and a single-sided roughened film was obtained according to Example 1. The film forming conditions, the glossiness of the obtained film, the average roughness, the tensile strength and the elongation at break were measured.
The results obtained are shown in Table 1. The appearance of the film is
The surface was rough in all the examples.

Example 13 A 200 ml reactor equipped with a thermometer, a stirrer and a nitrogen inlet tube was charged with 50 g of polyimide solution (A1) and 4.08 of DSDA.
g (0.0114 mol), BAPS 4.92 g (0.0
114 mol) and 41 g of NMP, and under a nitrogen atmosphere,
The reaction was carried out at room temperature for 5 hours to obtain an emulsified viscous polyimide / polyamic acid equivalent weight solution. The solution was processed in the same manner as in Example 1 (film forming condition: 250 ° C./30
Min), and a one-sided roughened film was obtained. The obtained film has a rough appearance, a glossiness of 32.5%, and an average roughness (R
a) was 0.72 μm, the tensile strength was 11.5 kgf / mm ² and the elongation at break was 11.0%.

Comparative Example 1 25 g each of the polyimide solution (A1) and the polyimide solution (A2) were placed in 100 ml glass bottles and stirred at room temperature for 3 hours in a seesaw rotary rotor to obtain a transparent and homogeneous mixed solution. It was A film was formed from the solution in the same manner as in Example 1, but the surface was not roughened and was extremely smooth. The film forming conditions, the glossiness of the obtained film, the average roughness, the tensile strength and the elongation at break were measured. The results obtained are shown in Table 1.

Comparative Example 2 Polyamic Acid Solution (B1) and Polyamic Acid Solution (B2)
25 g of each of these were placed in a 100 ml glass bottle, and the mixture was stirred with a seesaw rotary rotor at room temperature for 3 hours to obtain a transparent and uniform mixed solution. A film was formed from the solution by the same method as in Example 1, but the surface of the obtained film was not roughened and was extremely smooth. The film forming conditions, the glossiness of the obtained film, the average roughness, the tensile strength and the elongation at break were measured. The results obtained are shown in Table 1.

[0061]

By applying the method according to the present invention, a roughened polyimide film can be easily obtained. Moreover, the obtained polyimide film has excellent slipperiness and adhesiveness.

[Table 1]

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-1-110535 (JP, A) JP-A-6-5997 (JP, A) JP-A-5-214135 (JP, A) JP-A-5- 212807 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 73/00-73/26 C08J 5/18

Claims (3)

(57) [Claims] 1. A method for producing a roughened polyimide film, which comprises casting a mixture containing an organic solvent-soluble aromatic polyimide, a polyamic acid and an organic solvent, followed by dehydration and solvent removal. 2. An organic solvent-soluble aromatic polyimide resin represented by the general formula (1): [In the formula, A represents a single _{bond, -SO 2 -, - CO -} , - O- or _{-C (-CF 3) (- CF} 3) - represents a. Z ¹ is −
S- represents a group represented by the formula a, a group represented by the formula b, or a group represented by the general formula c. m represents an integer. ] An organic solvent-soluble aromatic polyimide having a repeating unit represented by the following general formula (2) [In the formula, R ³ represents a tetravalent organic group. R ⁴ represents a divalent organic group. n represents an integer. ] The manufacturing method of the roughened polyimide film of Claim 1 which is a polyamic acid which has a repeating unit represented by these. [Chemical 1] [Chemical 2] [Chemical 3] [In the Formula, X is -O-, -S-, or -C (-R < ¹ >) (-R
² )-, Y is a single bond, -O-, -S-, -C (-
^{R 1) (- R 2)} - or an -CO-. R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 5 carbon atoms which may be substituted with a halogen atom. ] 3. An organic solvent-soluble aromatic polyimide,
3,3 ', 4,4'-diphenylsulfone tetracarboxylic acid dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride 3,3 ', 4,4'-biphenyltetracarboxylic acid Dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 2,2-bis (3,3
The surface-roughened polyimide film according to claim 1 or 2, which is a polyimide having one or more compounds selected from the group consisting of 4-dicarboxyphenyl) hexafluoropropane dianhydride as an acid component. Production method.