JPH11158276A - Polyimide film improved in adhesiveness, and its production and laminate thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyimide film excellent in adhesiveness by specifying its Al content and completing its thermal treatment. SOLUTION: The Al content of a film comprising arom. tetracarboxylic acid residues and arom. diamine residues is made to be 1-1,000 ppm, pref. 4-1,000 ppm. and the thermal treatment of the film is completed. The film can be produced by reacting an arom. tetracarboxylic dianhydride with an arom. diamine in an org. solvent, homogeneously dissolving an Al compd. (e.g. aluminum hydroxide) in the resulting polyamic acid soln., casting the resulting dope on a carrier, thermally drying and peeling thus formed film from the carrier, and subjecting the dry film to imidization under heating at 420 deg.C or higher for 2-30 min or by coating a self-supporting film obtd. from a polyamic acid soln. with a soln. contg. the Al compd., drying the coated film, and subjecting it to imidization as above-mentioned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide film containing aluminum and having improved adhesiveness after completion of high-temperature heat treatment, a method for producing the same, and a laminate thereof. The present invention relates to a polyimide film having improved adhesiveness which does not require a process, a method for producing the same, and a laminate in which a metal foil and a molded body such as a polyimide film are bonded via a heat-resistant adhesive.

[0002]

2. Description of the Related Art Polyimide films are widely used for electronic equipment because of their excellent thermal and electrical properties. However, the polyimide film has a problem that a large adhesive strength cannot be obtained with an adhesive generally used in the electronic field, and a laminate having a large peel strength cannot be obtained even if a metal layer is formed by metal deposition or sputtering. .

[0003] Various attempts have been made to improve the low adhesion of the polyimide film. For example, JP-A-4-261466, JP-A-6-299
No. 883, Japanese Patent Publication No. Hei 7-503984,
The compound of tin, bismuth or antimony is 0.02-
An improved adhesion polyimide film containing 1% by weight is described. However, these polyimide films may be deteriorated in electric properties such as electric insulation. Also, JP-A-59-86634 and JP-A-2-8634 are disclosed.
No. 134241 describes a technique for improving the adhesiveness of a polyimide film by plasma discharge treatment.
However, in this discharge treatment, the effect of improving the adhesion of the polyimide film may be insufficient, and a complicated post-treatment step is required, resulting in low productivity. Further, Japanese Unexamined Patent Application Publication No.
JP-A No. 2-2, the aluminum film of a polyimide film is disclosed.
A technique for improving adhesion by forming a compound film is described. However, according to the above-mentioned publication, a high-temperature heat treatment is required after the step of exhibiting the adhesiveness, and the polyimide film cannot be used in general electronic equipment fields.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aromatic polyimide film which can be used in the electronic field while retaining the excellent properties such as thermal properties and electrical properties of an aromatic polyimide film. It is an object of the present invention to provide a polyimide film having good sputtering properties and metal vapor deposition properties, a method for producing the same, and a laminate.

[0005]

That is, the present invention provides:
The present invention relates to a polyimide film having an aluminum content of 1 to 1000 ppm and having improved adhesiveness after completion of a heat treatment.

The present invention also relates to a self-supporting film obtained by casting a dope solution obtained by adding an aluminum compound to a polyamic acid solution for forming a film and uniformly dissolving the solution, followed by drying by heating or by using a polyamic acid solution. A dried film containing an aluminum component obtained by applying a solution containing an aluminum compound to the resultant is dried at a temperature of 420 ° C. or higher to complete imidization, and the aluminum content of the film is 1 to 1000 ppm.
The present invention relates to a method for producing a polyimide film having improved adhesiveness, characterized by forming a polyimide film having the following characteristics.

Further, the present invention relates to a polyimide molded article having an aluminum content of 1 to 1000 ppm and having improved adhesion obtained by completing a heat treatment, which is provided on one or both surfaces with a heat-resistant adhesive. The present invention relates to a laminate in which foils are laminated.

In the present invention, the polyimide constituting the polyimide film or the polyimide molded body includes:
There is no particular limitation, and for example, any aromatic polyimide obtained from an aromatic tetracarboxylic dianhydride and an aromatic diamine can be used. Those in which some of these are replaced with alicyclic tetracarboxylic dianhydrides or aliphatic diamines can also be used. In addition, a part of these is 4-aminophthalic acid, 4-amino-5-methylphthalic acid, 4- (3,
It may be replaced with aminodicarboxylic acid such as 3′-dimethyl-4-anilino) phthalic acid and reacted.

The aromatic tetracarboxylic dianhydride includes, for example, 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride (hereinafter sometimes abbreviated simply as s-BPDA), pyro, and the like. Merritic dianhydride, benzophenone tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride (oxydiphthalic dianhydride) and the like can be mentioned. Examples of the aromatic diamine include paraphenylenediamine and 4,4′-diaminodiphenyl ether. Some of them are 4,4'-diaminodiphenyl sulfide, 4,4'-
Diaminobenzophenone, 4,4′-diaminodiphenylmethane, 2,2-bis (4-aminophenyl) propane, 1,4-bis (4-aminophenoxy) benzene,
4,4'-bis (4-aminophenyl) diphenyl-
Ter, 4,4'-bis (4-aminophenyl) diphenylsulfone, 4,4'-bis (4-aminophenyl) diphenylsulfide, 4,4'-bis (4-aminophenyl) diphenylmethane, 4,4 ' -Bis (4-aminophenoxy) diphenyl ether, 4,4'-bis (4
-Aminophenoxy) diphenyl sulfone, 4,4'-
Bis (4-aminophenoxy) diphenyl sulfide,
4,4'-bis (4-aminophenoxy) diphenylmethane, 2,2-bis [4- (aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, etc. Aromatic diamine having a plurality of benzene rings, 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecane, 1,12
-May be replaced by aliphatic diamines such as diaminododecane, diamines such as xylene diamine.

In particular, as polyimide, 3,3 ′, 4,
Polyimide obtained from 4'-biphenyltetracarboxylic dianhydride and paraphenylenediamine, pyromellitic dianhydride and 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride or benzophenone tetracarboxylic acid Aromatic tetracarboxylic acid component with dianhydride and paraphenylenediamine or paraphenylenediamine (P
Polyimide produced from an aromatic diamine component of PD (sometimes abbreviated as PD) and 4,4'-diaminodiphenyl ether (sometimes abbreviated as DADE) has a low coefficient of linear thermal expansion (usually 50-250). 1 × 10 ^{-5 in} the range of ° C.
−2 × 10 ⁻⁵ cm / cm / ° C.). In the case of a copolymer, the PPD / DADE (molar ratio) is preferably 100 / 0-15 / 85.
Polyimide can be achieved by homopolymerization, random polymerization, block polymerization, or any method in which two or more kinds of polyamic acids are synthesized in advance, and a polyamic acid solution is mixed to complete the reaction.

In the present invention, the ratio (in terms of aluminum metal) of aluminum (which is considered to be present as aluminum oxide in the form of aluminum) of the polyimide film or polyimide molded product is 1-.
It needs to be 1000 ppm, preferably 4-1000 ppm. When the amount of aluminum on the surface of the polyimide film or the polyimide molded article is 1 ppm or less, the improvement of the adhesiveness is not sufficient, and when the amount is 1000 ppm or more, the mechanical properties of the polyimide film are deteriorated and the adhesiveness is also unfavorably reduced.

The polyimide film containing aluminum in the above-mentioned ratio and having improved adhesion obtained by completing the heat treatment according to the present invention comprises, for example, the use of each of the above-mentioned components, a diamine component and a tetracarboxylic dianhydride. Approximately equimolar amounts are reacted in an organic solvent to form a polyamic acid solution (partially imidized if a uniform solution state is maintained), and an aluminum compound is added to the polyamic acid solution. A solution containing an aluminum compound is applied to a dry film that has been added and uniformly dissolved and cast on a support, then dried by heating and then peeled off from the support, or a self-supporting film obtained from a polyamic acid solution. The dried film containing the aluminum component obtained by drying after drying is 420 ° C. or higher, preferably 430-5.
The film was heated at a temperature of 20 ° C., preferably for about 2 to 30 minutes, to complete the imidization and to reduce the aluminum content of the film to 1
A thickness of 25-125 μm, especially 4
By forming a polyimide film of about 5-125 μm, a polyimide film with improved adhesion can be obtained.

As the aluminum compound, an aluminum compound soluble in a polyamic acid solution can be suitably used. Examples of these aluminum compounds include aluminum hydroxide, aluminum monoethyl acetate diisopropylate, aluminum diethyl acetate monoisopropylate, aluminum triacetylacetonate, aluminum triethylacetoacetate, and aluminum isopropylate. And organic aluminum compounds such as aluminum butyrate. Particularly, the organic aluminum compound is preferably aluminum triacetylacetonate.

In the method of the present invention, when a solution containing an aluminum compound is applied to the self-supporting film, the concentration of the aluminum compound to be applied is 0.01-5%.
It is preferable that the amount is about 0.02 to 5% by weight. The solvent used in the coating solution is not particularly limited, and may include alcohols, aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, ketone solvents, ether solvents, and amide solvents. Can be used.

The self-supporting film is prepared, for example, by mixing the above-mentioned acid component and diamine component in an organic solvent at about 100 ° C.
Hereinafter, the reaction is carried out at a temperature of 20-60 ° C. in particular to form a polyamic acid solution. This polyamic acid solution is used as a dope solution, and the dope solution is cast on a support.
It can be obtained by drying at about 200 ° C. to form a thin film and peeling it from the support. An organic phosphorus compound, for example, triphenyl phosphite, triphenyl phosphate, or the like, is used in an amount of 0.01 to 1% based on the solid content (polymer) concentration at the time of polyamic acid polymerization so that the peeling can be easily performed. It can be added in a range.

The organic solvent used for the production of the polyamic acid is N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-dimethylacetamide.
N-diethylacetamide, dimethylsulfoxide, hexamethylphosphoramide, N-methylcaprolactam and the like can be mentioned. These organic solvents may be used alone or in combination of two or more.

For the purpose of accelerating the imidization, a basic organic compound can be added to the raw material solution. For example, imidazole, 2-methylimidazole, 1,2
-Dimethyl imidazole, 2-phenyl imidazole,
Triethylamine or the like can be used at a rate of 0.1 to 10% by weight based on the solid content concentration at the time of polyamic acid polymerization.

The metal foil laminate of the present invention comprises a polyimide film, a plate or a molded article of various shapes containing 1-1000 ppm of aluminum, which has been subjected to a heat treatment and has improved adhesion. It can be obtained by providing a heat-resistant adhesive layer on one or both sides of the body, further laminating a metal foil, and applying heat and pressure. The heat-resistant adhesive is not particularly limited as long as it is a heat-resistant adhesive used in the electronic field. For example, a polyimide-based adhesive, an epoxy-modified polyimide-based adhesive, and a phenolic resin-modified epoxy resin adhesive , An epoxy-modified acrylic resin-based adhesive, an epoxy-modified polyamide-based adhesive, and the like. This heat-resistant adhesive layer can be provided by any method that is used in the field of electronics per se, for example, by applying an adhesive solution to the above-mentioned polyimide film or molded article.
It may be dried or bonded to a separately formed film adhesive.

The metal foil used in the present invention may be a single metal or alloy such as copper, aluminum,
Various metal foils and plating layers such as gold, silver, nickel and stainless steel foils and plating layers are mentioned, and preferably, rolled copper, electrolytic copper and the like are mentioned. The thickness of the metal foil is not particularly limited, but is preferably 0.1 μm to 10 mm, particularly preferably 10 μm to 60 μm.

The laminate of the present invention may be further bonded with another substrate, for example, a ceramic, a glass substrate, a silicon wafer, or a molded product of the same or different metal or polyimide film with a heat-resistant adhesive. .

The polyimide film and the laminate having improved adhesion obtained by the present invention can maintain the physical properties of the polyimide itself by a simple operation and have good adhesiveness, so that it is suitable as a material in the electronic field. Can be used.

[0022]

The present invention will be described below in more detail with reference to examples and comparative examples. The coefficient of thermal expansion is 10 ° C /
Measured in minutes. The aluminum content in the polyimide film was measured by the following ICP emission analysis. Sample (about 1
g) was dissolved in acid after combustion and carbonization and incineration, and quantified by ICP emission spectrometry (plasma excitation emission spectroscopy) using an analyzer (UOP-1 MARK-2 type, manufactured by Kyoto Koken Co., Ltd.). .

Example of Synthesis of Dope for Forming Polyimide Film N, N-dimethylacetamide 18 was placed in a 300 ml glass reaction vessel equipped with a stirrer, nitrogen inlet tube and reflux tube.
3 g and 0.1 g of the phosphoric acid compound (Separ 365-
100, manufactured by Chukyo Yushi Co., Ltd.), and stirred under a nitrogen flow with 10.81 g (0.1%) of paraphenylenediamine.
000 mol), and the mixture was kept at 50 ° C. and completely dissolved. To this solution, 29.229 g (0.09935 mol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was gradually added while paying attention to heat generation.
The reaction was continued for 5 hours while maintaining the temperature at 0 ° C. After this,
0.2381 g (0.00065 mol) of 3 ', 4,4'-biphenyltetracarboxylic acid dihydrate was dissolved.
The resulting polyamic acid solution is a brown viscous liquid,
The solution viscosity at 5 ° C. was about 1500 poise. As a single layer (50 μm) of a polyimide film separately manufactured from this dope, the coefficient of thermal expansion at 50 to 200 ° C. was 1.5 × 10 ⁻⁵ cm / cm / ° C.

Production Example of Laminate-1 Adhesion sheet (manufactured by DuPont) between an electrolytic copper foil (3EC-3 manufactured by Mitsui Kinzoku Mining Co., Ltd.) and a polyimide film.
(Pyralux WA, thickness μm)
kg / cm ² at 180 ° C. for 1 minute, followed by heat treatment in a hot air oven at 180 ° C. for 30 minutes,
After cooling, a laminate was obtained. About this laminated body,
The strength (25 ° C.) was measured.

Production Example 2 of Laminated Body After the polyimide film surface was subjected to ordinary pretreatment, a copper thin film was formed by an electron beam evaporation method. After placing the film cut into the holder size in the vapor deposition apparatus, the substrate temperature is 150 ° C., the degree of vacuum is 2 × 10 ⁻⁴ Pa or less, and the raw material copper purity is 4
A copper film having a thickness of 0.2 μm was deposited under the conditions of N and a deposition rate of about 10-25 Å / sec. Further, a 10 μm copper layer was formed thereon by electrolytic plating. The laminate was immersed in 2N hydrochloric acid for 5 minutes, and then the T-peel strength (25 ° C.) was measured.

Example 1-4 The above-mentioned polyamic acid solution was applied by casting onto a glass substrate, dried at 150 ° C. for 10 minutes, peeled off the substrate and restrained on a frame. After applying a toluene solution of aluminum triacetylacetonate having the concentration shown in (1), 480 minutes at 200 ° C. for 3 minutes and 300 ° C. for 3 minutes.
Heat treatment was performed at 4 ° C. for 4 minutes to obtain a polyimide film having a thickness of 50 μm. Using this film, a laminate was obtained. The results are summarized in Tables 1 and 2.

Example 5 A dope obtained by adding aluminum hydroxide in the amount shown in Tables 1 and 2 to the above-mentioned polyamic acid solution and uniformly dissolving it was cast and applied on a glass substrate. Dry for a minute,
The polyimide film was peeled off from the substrate, restrained on a frame, and heat-treated at 200 ° C. for 3 minutes, 300 ° C. for 3 minutes, and 480 ° C. for 4 minutes to obtain a polyimide film having a thickness of 50 μm. Using this film, a laminate was obtained. The results are summarized in Tables 1 and 2.

Example 6-11 Dopes prepared by adding aluminum hydroxide in the amounts shown in Tables 1 and 2 to the above-mentioned polyamic acid solution and uniformly dissolving the resulting solution were cast on a glass substrate, and the resulting solution was coated at 150 ° C. And dry for 10 minutes
Peeled from the substrate and restrained on the frame, Tables 1 and 2
After the application of a toluene solution of aluminum triacetylacetonate having the concentration shown in
Heat treated at 0 ° C for 3 minutes and 480 ° C for 4 minutes to 50μ thickness
m was obtained. Using this film, a laminate was obtained. The results are summarized in Tables 1 and 2.

Examples 12 to 13 The above-mentioned polyamic acid solution was applied by casting onto a glass substrate, dried at 150 ° C. for 10 minutes, peeled off the substrate and restrained on a frame. After a DMAc solution of an aluminum chelate compound (ALCH, manufactured by Kawaken Fine Chemical Co., Ltd.) having the concentration shown in
For 3 minutes, 300 ° C. for 3 minutes and 480 ° C. for 4 minutes to obtain a 50 μm thick polyimide film. Using this film, a laminate was obtained. The results are summarized in Table 1,
It is shown in Table 2.

Further, when the tensile strength, elongation, bending resistance, and insulation properties of the polyimide film obtained in each of the examples were confirmed, it was almost the same as the conventionally known polyimide film.

Comparative Example 1 A polyamic acid solution was applied by casting onto a glass substrate.
After drying at 0 ° C. for 10 minutes, peeling off from the substrate and restraining on a frame, it is performed at 200 ° C. for 3 minutes and at 300 ° C. for 3 minutes.
Heat treatment was performed at 4 ° C. for 4 minutes to obtain a polyimide film having a thickness of 50 μm. Using this film, a laminate was obtained. The results are summarized in Tables 1 and 2.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

According to the present invention, a polyimide film and a laminate having improved adhesion can be obtained by a simple operation.

Further, according to the present invention, it is possible to obtain a polyimide film and a laminate having improved adhesiveness and good adhesiveness while maintaining the physical properties of the polyimide itself.

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Claims (5)

[Claims] 1. The film according to claim 1, wherein said film has an aluminum content of 1-1.
A polyimide film having an improved adhesion of 000 ppm after completion of the heat treatment. 2. The polyimide film with improved adhesion according to claim 1, wherein the film is formed from an aromatic tetracarboxylic acid residue and an aromatic diamine residue. 3. An aluminum compound is added to a polyamic acid solution for film formation, and a dope solution obtained by uniformly dissolving is cast and then dried by heating, or an aluminum compound is added to a self-supporting film obtained from the polyamic acid solution. A dried film containing an aluminum component obtained by applying and drying a solution containing the solution is heated at a temperature of 420 ° C. or more to complete imidization, and the aluminum film on the film surface has an aluminum content of 1 to 1000 ppm, a polyimide film. Forming a polyimide film having improved adhesion. 4. The molded product having an aluminum content of 1-10.
A laminate in which a metal foil is laminated with a heat-resistant adhesive on one or both surfaces of a polyimide molded article having an adhesion of 00 ppm and having improved adhesiveness after the completion of the heat treatment. 5. The laminate with improved adhesion according to claim 1, wherein the molded article is a polyimide film formed from an aromatic tetracarboxylic acid residue and an aromatic diamine residue.