JP7116889B2 - Heat-resistant polymer film, method for producing surface-treated heat-resistant polymer film, and heat-resistant polymer film roll - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat-resistant polymer film, a method for producing a surface-treated heat-resistant polymer film, and a heat-resistant polymer film roll.

In recent years, for the purpose of reducing the weight, size, thickness, and flexibility of functional elements such as semiconductor elements, MEMS elements, and display elements, the development of techniques for forming these elements on polymer films has been actively carried out. That is, conventionally, as a material for the base material of electronic parts such as information communication equipment (broadcasting equipment, mobile radio, portable communication equipment, etc.), radar, high-speed information processing equipment, etc., it has heat resistance and the signal of information communication equipment Ceramics have been used to support higher frequencies (up to the GHz band), but ceramics are not flexible and are difficult to thin. uses a polymer film as the substrate.

When forming functional elements such as semiconductor elements, MEMS elements, and display elements on the surface of a polymer film, it is ideal to use the so-called roll-to-roll process, which takes advantage of the flexibility that characterizes polymer films. It is said that However, in industries such as the semiconductor industry, the MEMS industry, the display industry, and the like, so far, process technologies have been established for rigid planar substrates such as wafer bases or glass substrate bases. Therefore, in order to form a functional element on a polymer film using the existing infrastructure, the polymer film is attached to a rigid support made of an inorganic material such as a glass plate, a ceramic plate, a silicon wafer, or a metal plate. , forming desired elements thereon, and then separating from the support.

By the way, in the process of forming a desired functional element in a laminate obtained by laminating a polymer film and an inorganic support, the laminate is often exposed to high temperatures. For example, formation of functional elements such as polysilicon and oxide semiconductors requires a process in a temperature range of about 200.degree. C. to 600.degree. In the production of a hydrogenated amorphous silicon thin film, a temperature of about 200 to 300° C. may be applied to the film. Heating may be required. Therefore, the polymer films constituting the laminate are required to have heat resistance, but as a matter of fact, only a limited number of polymer films can be put to practical use in such a high temperature range. In general, it is conceivable to use a pressure-sensitive adhesive or an adhesive for laminating a polymer film to a support. Adhesives) are also required to have heat resistance. However, since ordinary bonding adhesives and pressure-sensitive adhesives do not have sufficient heat resistance, bonding using adhesives or pressure-sensitive adhesives cannot be applied when the forming temperature of the functional element is high.

Since it is believed that there are no pressure-sensitive adhesives or adhesives with sufficient heat resistance, conventionally, in the above-mentioned applications, a polymer solution or a polymer precursor solution is coated on an inorganic substrate, and then the inorganic substrate is coated. A technique of drying and curing to form a film and using it for the application has been adopted. However, since the polymer film obtained by such means is fragile and easily torn, the functional element formed on the surface of the polymer film is often broken when peeled off from the inorganic substrate. In particular, it is extremely difficult to peel a large-area film from an inorganic substrate, and it is almost impossible to obtain an industrially viable yield.
In view of this situation, as a laminate of a polymer film and an inorganic substrate for forming a functional element, a polyimide film that has excellent heat resistance and is tough and can be thinned is applied to the inorganic substrate via a silane coupling agent. Laminates bonded to each other have been proposed (see, for example, Patent Documents 1 to 3).

Japanese Patent No. 5152104 Japanese Patent No. 5304490 Japanese Patent No. 5531781

The present inventors further conducted extensive research on heat-resistant polymer films such as polyimide films. As a result, when a heat-resistant polymer film is surface-treated with a polyvalent amine compound, it surprisingly has sufficient heat resistance equal to or higher than that obtained when a silane coupling agent is used, and the inorganic substrate and The inventors have found that the adhesive strength of the adhesive becomes good, and have completed the present invention. In addition, the present inventors have found that surface treatment of heat-resistant polymer films using polyvalent amine compounds can be performed more easily than in the case of using silane coupling agents. It was also found that

That is, the heat-resistant polymer film according to the present invention is
A heat-resistant polymer film having a surface-treated first surface,
The nitrogen content of the first surface is 0.45 atom % or more higher than the nitrogen content of the central portion in the thickness direction of the heat-resistant polymer film.

According to the above configuration, the nitrogen content of the first surface is 0.45 atomic % or more higher than the nitrogen content of the central portion in the thickness direction of the heat-resistant polymer film. It can be said that the surface is treated with a compound. Such a heat-resistant polymer film has sufficient heat resistance and good adhesion to an inorganic substrate. This is also clear from the description of the examples.
Moreover, since the heat-resistant polymer film can be obtained by surface treatment with a polyvalent amine compound, it is excellent in productivity.

In addition, the method for producing a surface-treated heat-resistant polymer film according to the present invention comprises:
A step A of applying a polyvalent amine compound to a heat-resistant polymer film;
After the step A, a step B of maintaining the heat-resistant polymer film within a range of 0° C. or more and less than 60° C.;
After the step B, a step C of maintaining the heat-resistant polymer film within a range of 60° C. or higher and 250° C. or lower is provided.

According to the above configuration, after the polyamine compound is applied to the heat-resistant polymer film, it is held at a temperature in the range of 0° C. or higher and lower than 60° C., and then the heat-resistant polymer film is heated at a temperature of 60° C. or higher and 250° C. or lower. A surface-treated heat-resistant polymer film can be obtained by keeping it within the range. Therefore, it is superior in productivity. In addition, the surface-treated heat-resistant polymer film obtained in this way has sufficient heat resistance and good adhesion to an inorganic substrate. This is also clear from the description of the examples.
The present inventors found that in step B, the heat-resistant polymer film was partially decomposed by a polyvalent amine compound, and in step C, the functional groups on the surface of the heat-resistant polymer film generated by the partial decomposition and the polyvalent amine compound It is surmised that the surface-treated heat-resistant polymer film of the present invention is obtained. In other words, if step C is performed without step B, the heat-resistant polymer film will be exposed to a sudden high temperature, and the polyvalent amine compound will volatilize before the heat-resistant polymer film is partially decomposed. It is speculated that surface treatment will not be performed.

In the above configuration, the polyvalent amine compound preferably has a molecular weight of 300 or less.

When the molecular weight of the polyvalent amine compound is 300 or less, many of the compounds are in a liquid state at room temperature, and can be easily used in a vapor phase coating method.

In the above configuration, the boiling point of the polyvalent amine compound is preferably 50°C or higher and 250°C or lower.

When the boiling point of the polyvalent amine compound is 50° C. or higher, volatilization of the polyvalent amine compound during the step B can be suppressed. Further, when the boiling point of the polyvalent amine compound is 250° C. or lower, the excessive polyvalent amine compound can be suitably volatilized in the step C.
In addition, in this specification, the boiling point means the boiling point at normal pressure (1 atm).

In the above configuration, the polyvalent amine compound is preferably a diamine compound.

When the polyvalent amine compound is a diamine compound, the adhesive strength (peel strength) to an inorganic substrate becomes better. Moreover, even if the laminate after being bonded to the inorganic substrate is exposed to a high temperature (for example, 500° C. for 1 hour), it is possible to further suppress an increase in the peel strength. The present inventors have found that the reason for this is that diamine is a substance that acts on both the inorganic substrate and the film, and the higher the valence, the higher the adhesive force tends to be. can be obtained. Also, it is speculated that the film is slightly deteriorated after being exposed to high temperatures, forming a layer that can be easily peeled off.

In the above configuration, the polyvalent amine compound is preferably a branched aliphatic polyvalent amine compound.

When the polyvalent amine compound is a branched aliphatic polyvalent amine compound, even if the compound has the same number of carbon atoms, it generally has a lower boiling point than the straight-chain aliphatic polyvalent amine compound, and can be applied to a film by a vapor phase coating method or the like. Processing can be performed more easily.

Further, the heat-resistant polymer film roll according to the present invention is
The heat-resistant polymer film is wound into a roll.

According to the above configuration, since the heat-resistant polymer film is wound in a roll shape, it can be easily transported in the form of a surface-treated heat-resistant polymer film.

Further, the laminate according to the present invention is
the heat-resistant polymer film;
an inorganic substrate;
The first surface of the heat-resistant polymer film is laminated so as to face the inorganic substrate.

Further, the method for manufacturing a laminate according to the present invention includes:
a step X of placing the first surface of the heat-resistant polymer film and the inorganic substrate so as to face each other;
After the step X, a step Y of pressurizing the heat-resistant polymer film and the inorganic substrate to obtain a contact body;
After the step Y, the method further includes a step Z of heat-treating the adhered body.

In the laminate, the 90° peel strength A between the inorganic substrate and the heat-resistant polymer film after heat treatment at 200° C. for 1 hour in an air atmosphere is preferably 0.05 N/cm or more.

In the laminate, the 90° peel strength B between the inorganic substrate and the heat-resistant polymer film after heat treatment at 200°C for 1 hour in an air atmosphere and then heating at 500°C for 1 hour in a nitrogen atmosphere is 0. It is preferably 0.50 N/cm or less.

Further, the method for manufacturing a flexible electronic device according to the present invention includes:
forming an electronic device on the heat-resistant polymer film surface of the laminate;
and peeling the electronic device together with the heat-resistant polymer film from the inorganic substrate.

According to the present invention, it is possible to provide a heat-resistant polymer film that has sufficient heat resistance and good adhesion to an inorganic substrate. Also, a method for producing the surface-treated heat-resistant polymer film can be provided. Also, a heat-resistant polymer film roll can be provided in which the surface-treated heat-resistant polymer film is wound into a roll.

Embodiments of the present invention will be described below.

<Heat-resistant polymer film>
The heat-resistant polymer film according to this embodiment is
having a surface-treated first surface;
The nitrogen content of the first surface is higher by 0.45 atom % or more than the nitrogen content of the central portion in the thickness direction of the heat-resistant polymer film.

As described above, in the heat-resistant polymer film, the nitrogen content of the first surface is higher than the nitrogen content of the central portion in the thickness direction of the heat-resistant polymer film by 0.45 atomic % or more. The nitrogen content of the first surface is preferably 1 atomic % or more, more preferably 2 atomic % or more, than the nitrogen content of the central portion in the thickness direction of the heat-resistant polymer film. The method for measuring the nitrogen content is according to the method described in Examples.

According to the heat-resistant polymer film, the nitrogen content of the first surface is higher than the nitrogen content of the central portion in the thickness direction of the heat-resistant polymer film by 0.45 atomic % or more. It can be said that the surface is treated with a polyvalent amine compound. Such a heat-resistant polymer film has sufficient heat resistance and good adhesion to an inorganic substrate. This is also clear from the description of the examples.
Moreover, since the heat-resistant polymer film can be obtained by surface treatment with a polyvalent amine compound, it is excellent in productivity.

As used herein, the heat-resistant polymer is a polymer having a melting point of 400° C. or higher, preferably 500° C. or higher, and a glass transition temperature of 250° C. or higher, preferably 320° C. or higher, more preferably 380° C. or higher. . In the following, to avoid complication, it is simply referred to as a polymer. As used herein, the melting point and glass transition temperature are determined by differential thermal analysis (DSC). If the melting point exceeds 500° C., it may be determined whether or not the melting point has been reached by observing the thermal deformation behavior when heated at the relevant temperature.

Examples of the heat-resistant polymer film (hereinafter also simply referred to as a polymer film) include polyimide resins such as polyimide, polyamideimide, polyetherimide, and fluorinated polyimide (eg, aromatic polyimide resin, alicyclic polyimide resin); polyethylene , polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate (for example, wholly aromatic polyester, semi-aromatic polyester); copolymerized (meth)acrylates represented by polymethyl methacrylate; polycarbonates cellulose acetate; cellulose nitrate; aromatic polyamide; polyvinyl chloride; polyphenol; polyarylate; polyphenylene sulfide;
However, since the polymer film is assumed to be used in a process involving heat treatment at 450° C. or higher, the polymer films exemplified are limited in practical application. Among the polymer films, preferred are films using so-called super engineering plastics, and more specifically, aromatic polyimide films, aromatic amide films, aromatic amide imide films, aromatic benzoxazole films, aromatic group benzothiazole films, aromatic benzimidazole films, and the like.

The details of a polyimide resin film (also referred to as a polyimide film), which is an example of the polymer film, will be described below. In general, a polyimide resin film is prepared by applying a polyamic acid (polyimide precursor) solution obtained by reacting diamines and tetracarboxylic acids in a solvent to a support for producing a polyimide film and drying it to form a green film (hereinafter referred to as (also referred to as "polyamic acid film"), and further subjecting the green film to a high-temperature heat treatment on a polyimide film-producing support or in a state in which the green film is peeled off from the support to cause a dehydration ring-closing reaction.

Application of the polyamic acid (polyimide precursor) solution is, for example, spin coating, doctor blade, applicator, comma coater, screen printing method, slit coating, reverse coating, dip coating, curtain coating, slit die coating, etc. Application of conventionally known solutions means can be used as appropriate.

The diamines constituting the polyamic acid are not particularly limited, and aromatic diamines, aliphatic diamines, alicyclic diamines and the like which are commonly used in polyimide synthesis can be used. From the viewpoint of heat resistance, aromatic diamines are preferred, and among aromatic diamines, aromatic diamines having a benzoxazole structure are more preferred. The use of aromatic diamines having a benzoxazole structure makes it possible to exhibit high heat resistance, high elastic modulus, low thermal shrinkage, and low coefficient of linear expansion. Diamines may be used alone or in combination of two or more.

Aromatic diamines having a benzoxazole structure are not particularly limited, and examples include 5-amino-2-(p-aminophenyl)benzoxazole, 6-amino-2-(p-aminophenyl)benzoxazole, 5 -amino-2-(m-aminophenyl)benzoxazole, 6-amino-2-(m-aminophenyl)benzoxazole, 2,2'-p-phenylenebis(5-aminobenzoxazole), 2,2' -p-phenylenebis(6-aminobenzoxazole), 1-(5-aminobenzoxazolo)-4-(6-aminobenzoxazolo)benzene, 2,6-(4,4'-diaminodiphenyl)benzo [1,2-d:5,4-d′]bisoxazole, 2,6-(4,4′-diaminodiphenyl)benzo[1,2-d:4,5-d′]bisoxazole, 2, 6-(3,4′-diaminodiphenyl)benzo[1,2-d:5,4-d′]bisoxazole, 2,6-(3,4′-diaminodiphenyl)benzo[1,2-d: 4,5-d']bisoxazole, 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(3,3' -diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole and the like.

Examples of aromatic diamines other than the above aromatic diamines having a benzoxazole structure include 2,2′-dimethyl-4,4′-diaminobiphenyl, 1,4-bis[2-(4-aminophenyl )-2-propyl]benzene (bisaniline), 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 4,4 '-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl ] sulfide, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl ]-1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 3,3′- Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4' -diaminodiphenyl sulfoxide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4, 4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis[4-(4-aminophenoxy)phenyl]methane, 1,1-bis[ 4-(4-aminophenoxy)phenyl]ethane, 1,2-bis[4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[4-(4-aminophenoxy)phenyl]propane, 1, 2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl] Propane, 1,1-bis[4-(4-aminophenoxy)phenyl]butane, 1,3- bis[4-(4-aminophenoxy)phenyl]butane, 1,4-bis[4-(4-aminophenoxy)phenyl]butane, 2,2-bis[4-(4-aminophenoxy)phenyl]butane, 2,3-bis[4-(4-aminophenoxy)phenyl]butane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3-methylphenyl]propane , 2,2-bis[4-(4-aminophenoxy)-3-methylphenyl]propane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3 ,5-dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1 , 1,1,3,3,3-hexafluoropropane, 1,4-bis(3-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-amino phenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4- (4-aminophenoxy)phenyl]sulfoxide, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl] ether, 1,3-bis[4-(4-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-amino phenoxy)benzoyl]benzene, 4,4'-bis[(3-aminophenoxy)benzoyl]benzene, 1,1-bis[4-(3-aminophenoxy)phenyl]propane, 1,3-bis[4-( 3-aminophenoxy)phenyl]propane, 3,4′-diaminodiphenyl sulfide, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane , bis[4-(3-aminophenoxy)phenyl]methane, 1,1-bis[4-(3-aminophenoxy)phenyl]ethane, 1,2-bis[4-(3-aminophenoxy)phenyl]ethane , bis[4-(3-aminophenoxy)phenyl]sulfoxide, 4,4′-bis[ 3-(4-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[3-(3-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[4-(4-amino-α,α-dimethyl benzyl)phenoxy]benzophenone, 4,4′-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenylsulfone, bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone , 1,4-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene , 1,3-bis[4-(4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-fluorophenoxy)- α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-methylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino- 6-cyanophenoxy)-α,α-dimethylbenzyl]benzene, 3,3′-diamino-4,4′-diphenoxybenzophenone, 4,4′-diamino-5,5′-diphenoxybenzophenone, 3,4 '-diamino-4,5'-diphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino-4-phenoxybenzophenone, 3 ,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4'-diamino -4,5'-dibiphenoxybenzophenone, 3,3'-diamino-4-biphenoxybenzophenone, 4,4'-diamino-5-biphenoxybenzophenone, 3,4'-diamino-4-biphenoxybenzophenone, 3 ,4'-diamino-5'-biphenoxybenzophenone, 1,3-bis(3-amino-4-phenoxybenzoyl)benzene, 1,4-bis(3-amino-4-phenoxybenzoyl)benzene, 1,3 -bis(4-amino-5-phenoxybenzoyl)benzene, 1,4-bis(4-amino-5-phenoxybenzoyl)benzene, 1,3-bis(3-amino-4-biphenyl noxybenzoyl)benzene, 1,4-bis(3-amino-4-biphenoxybenzoyl)benzene, 1,3-bis(4-amino-5-biphenoxybenzoyl)benzene, 1,4-bis(4- amino-5-biphenoxybenzoyl)benzene, 2,6-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzonitrile, and some of the hydrogen atoms on the aromatic rings of said aromatic diamines or all of which are halogen atoms, alkyl or alkoxyl groups having 1 to 3 carbon atoms, cyano groups, or halogen atoms having 1 to 3 carbon atoms in which some or all of the hydrogen atoms of an alkyl or alkoxyl group are substituted with halogen atoms and aromatic diamines substituted with alkyl groups or alkoxyl groups.

Examples of the aliphatic diamines include 1,2-diaminoethane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,8-diaminooctane and the like.
Examples of the alicyclic diamines include 1,4-diaminocyclohexane and 4,4'-methylenebis(2,6-dimethylcyclohexylamine).
The total amount of diamines other than aromatic diamines (aliphatic diamines and alicyclic diamines) is preferably 20% by mass or less, more preferably 10% by mass or less, and still more preferably 5% by mass or less of all diamines. is. In other words, aromatic diamines are preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of all diamines.

Tetracarboxylic acids constituting polyamic acid include aromatic tetracarboxylic acids (including their acid anhydrides), aliphatic tetracarboxylic acids (including their acid anhydrides), and alicyclic tetracarboxylic acids, which are commonly used in polyimide synthesis. Acids (including anhydrides thereof) can be used. Among them, aromatic tetracarboxylic anhydrides and alicyclic tetracarboxylic anhydrides are preferable, aromatic tetracarboxylic anhydrides are more preferable from the viewpoint of heat resistance, and alicyclic anhydrides are preferable from the viewpoint of light transmittance. Group tetracarboxylic acids are more preferred. When these are acid anhydrides, one or two anhydride structures may be present in the molecule, but preferably those having two anhydride structures (dianhydrides) are good. Tetracarboxylic acids may be used alone, or two or more of them may be used in combination.

Examples of alicyclic tetracarboxylic acids include alicyclic tetracarboxylic acids such as cyclobutanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, and 3,3′,4,4′-bicyclohexyltetracarboxylic acid. Carboxylic acids, and their acid anhydrides. Among these, dianhydrides having two anhydride structures (for example, cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3′,4,4 '-bicyclohexyltetracarboxylic dianhydride) are preferred. The alicyclic tetracarboxylic acids may be used alone, or two or more of them may be used in combination.
The alicyclic tetracarboxylic acid is, for example, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of the total tetracarboxylic acids when transparency is important.

The aromatic tetracarboxylic acid is not particularly limited, but is preferably a pyromellitic acid residue (that is, having a structure derived from pyromellitic acid), more preferably an acid anhydride thereof. Examples of such aromatic tetracarboxylic acids include pyromellitic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic dianhydride, 3 ,3′,4,4′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis[4-(3,4-di carboxyphenoxy)phenyl]propanoic anhydride and the like.
The aromatic tetracarboxylic acid is, for example, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of the total tetracarboxylic acids when heat resistance is important.

The thickness of the polymer film is preferably 3 μm or more, more preferably 11 μm or more, still more preferably 24 μm or more, and still more preferably 45 μm or more. Although the upper limit of the thickness of the polymer film is not particularly limited, it is preferably 250 μm or less, more preferably 150 μm or less, and still more preferably 90 μm or less for use as a flexible electronic device.

The average CTE between 30° C. and 500° C. of said polymer film is preferably between −5 ppm/° C. and +20 ppm/° C., more preferably between −5 ppm/° C. and +15 ppm/° C., more preferably 1 ppm. /°C to +10 ppm/°C. When the CTE is within the above range, the difference in coefficient of linear expansion with a general support (inorganic substrate) can be kept small, and peeling of the polymer film and the inorganic substrate can be prevented even when subjected to a process of applying heat. can be avoided. Here, CTE is a factor representing reversible expansion and contraction with respect to temperature.

The heat shrinkage of the polymer film between 30° C. and 500° C. is preferably ±0.9%, more preferably ±0.6%. Thermal shrinkage is a factor representing irreversible expansion and contraction with respect to temperature.

The tensile strength at break of the polymer film is preferably 60 MPa or more, more preferably 120 MPa or more, and still more preferably 240 MPa or more. Although the upper limit of the tensile strength at break is not particularly limited, it is practically less than about 1000 MPa. The tensile strength at break of the polymer film refers to the average value of the tensile strength at break in the machine direction (MD direction) and the tensile strength at break in the width direction (TD direction) of the polymer film.

The thickness unevenness of the polymer film is preferably 20% or less, more preferably 12% or less, still more preferably 7% or less, and particularly preferably 4% or less. If the thickness unevenness exceeds 20%, it tends to be difficult to apply to narrow areas. The uneven thickness of the film can be obtained by measuring the thickness of the film by randomly extracting about 10 positions from the film to be measured using, for example, a contact-type film thickness meter, and calculating the thickness according to the following formula.
Film thickness unevenness (%)
= 100 x (maximum film thickness - minimum film thickness) / average film thickness

The polymer film is preferably obtained in the form of being wound up as a long polymer film with a width of 300 mm or more and a length of 10 m or more at the time of production. More preferred are those in the form of molecular films. When the polymer film is wound into a roll, it can be easily transported in the form of a surface-treated heat-resistant polymer film.

In the polymer film, in order to ensure handleability and productivity, a lubricant (particles) having a particle diameter of about 10 to 1000 nm is added or contained in the polymer film in an amount of about 0.03 to 3% by mass. Therefore, it is preferable to provide the surface of the polymer film with fine irregularities to ensure the slipperiness.

The polymer film may be surface-activated before being surface-treated with the polyvalent amine compound. As used herein, surface activation treatment refers to dry or wet surface treatment. Examples of dry surface treatment include vacuum plasma treatment, normal pressure plasma treatment, treatment of irradiating the surface with active energy rays such as ultraviolet rays, electron beams, and X-rays, corona treatment, flame treatment, Itro treatment, and the like. can. Wet surface treatments include, for example, a treatment in which the polymer film surface is brought into contact with an acid or alkaline solution.

A plurality of the surface activation treatments may be performed in combination. Such surface activation treatment cleans the polymer film surface and creates more active functional groups. The generated functional group binds to the polyvalent amine compound through hydrogen bonding, chemical reaction, or the like, making it possible to firmly bond the polymer film and the polyvalent amine compound.

A protective film may be laminated on one side or both sides of the polymer film. The protective film is a film attached to the polymer film in order to protect the polymer film until the polymer film is used. peeled off.

The production method of the polymer film is not particularly limited as long as the nitrogen content of the first surface is higher than the nitrogen content of the central portion in the thickness direction of the polymer film by 0.45 atomic % or more. However, it can be suitably produced by, for example, the following "method for producing surface-treated heat-resistant polymer film".

<Method for producing surface-treated heat-resistant polymer film>
The method for producing a surface-treated heat-resistant polymer film according to the present embodiment includes:
A step A of applying a polyvalent amine compound to a heat-resistant polymer film;
After the step A, a step B of maintaining the heat-resistant polymer film within a range of 0° C. or more and less than 60° C.;
After the step B, at least a step C of maintaining the heat-resistant polymer film within the range of 60° C. or higher and 250° C. or lower.

<Step A>
In step A, a polyamine compound is applied to the heat-resistant polymer film before surface treatment with the polyamine compound.

<Polyvalent amine compound>
The polyvalent amine compound is not particularly limited as long as it is a compound having two or more amines. In addition, in this specification, the said amine means a primary amine. That is, in this specification, when counting the number of amines possessed by the polyvalent amine compound, the number of primary amines is counted. For example, triethylenetetramine has two primary amines and two secondary amines, but because it has two primary amines, it is classified as a diamine rather than a tetramine.

Specific examples of the polyvalent amine compound include 1,2-ethanediamine (ethylenediamine), 1,3-propanediamine, 2-methyl-2-propyl-1,3-propanediamine, 1,2-propanediamine, 2- Methyl-1,3-propanediamine, 1,4-butanediamine (putrescine), 2,3-dimethyl-1,4-butanediamine, 1,3-butanediamine, 1,2-butanediamine, 2-ethyl-1 ,4-butanediamine, 2-methyl-1,4-butanediamine, 1,5-pentanediamine, 2-methyl-1,5-pentanediamine (2-methyl-1,5-diaminopentane), 3-methyl-1,5 -pentanediamine, 3,3-dimethyl-1,5-pentanediamine, 1,4-pentanediamine, 2-methyl-1,4-pentanediamine, 3-methyl-1,4-pentanediamine, 1,3-pentane Diamine, 4,4-dimethyl-1,3-pentanediamine, 2,2,4-trimethyl-1,3-pentanediamine, 1,2-pentanediamine, 4-methyl-1,2-pentanediamine, 4-ethyl- 1,2-pentanediamine, 3-methyl-1,2-pentanediamine, 3-ethyl-1,2-pentanediamine, 2-methyl-1,3-pentanediamine, 4-methyl-1,3-pentanediamine, 1, 6-hexanediamine (hexamethylenediamine), 3-methyl-1,6-hexanediamine, 3,3-dimethyl-1,6-hexanediamine, 3-ethyl-1,6-hexanediamine, 1,5-hexanediamine, 1 ,4-hexanediamine, 1,3-hexanediamine, 1,2-hexanediamine, 2,5-hexanediamine, 2,5-dimethyl-2,5-hexanediamine, 2,4-hexanediamine, 2-methyl-2 ,4-hexanediamine, 2,3-hexanediamine, 5-methyl-2,3-hexanediamine, 3,4-hexanediamine, 1,7-heptanediamine, 2-methyl-1,7-heptanediamine, 1,6 -heptanediamine, 1,5-heptanediamine, 1,4-heptanediamine, 1,3-heptanediamine, 1,2-heptanediamine, 2,6-heptanediamine, 2,5-heptanediamine, 2,4- Heptanediamine, 2,3-heptanediamine, 3,5-heptanediamine, 3,4-heptanediamine, 1,8-octanediamine, 1,7-octanediamine, 1,6-octanediamine diamine, 1,5-octanediamine, 1,4-octanediamine, 1,3-octanediamine, 1,2-octanediamine, 2,7-octanediamine, 2,7-dimethyl-2,7-octanediamine, 2 ,6-octanediamine, 2,5-octanediamine, 2,4-octanediamine, 2,3-octanediamine, 3,6-octanediamine, 3,5-octanediamine, 3,4-octanediamine, diethylenetriamine, hydrocarbon-based diamines such as triethylenetetramine and 1,4,8-triazaoctane; and hydrocarbon-based triamines such as 1,3,5-pentanetriamine and 1,4,7-heptanetriamine.

Other specific examples of the polyvalent amine compound include aromatic diamines and alicyclic diamines. Examples thereof include pyridine-2,4-diamine, N2,N6-dimethyl-2,6-pyridinediamine, 2-pyridineamine, 2,3-pyridinediamine, 4,6-pyrimidinediamine, 2,4,6- pyrimidinetriamine, 2-amino-4-pyridinemethanamine, 2,3-pyrazinediamine, 2,5-pyridinediamine 1,2-cyclohexanediamine, 1-methyl-1,2-cyclohexanediamine, 3-methyl-1,2 -cyclohexanediamine, 4-methyl-1,2-cyclohexanediamine, 1,2-diamino-4-cyclohexene, 1,3-cyclohexanediamine, 2-methyl-1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 1 , 2,3-cyclohexanetriamine, 1,2-cyclopentanediamine, 1,3-cyclopentanediamine, 4,4′-methylenebis(cyclohexylamine), 4,5,6-pyrimidinetriamine, 2,4,6- triaminopyrimidine, 3,3'-diaminobenzidine and the like.

Among the polyvalent amine compounds, those having a molecular weight of 300 or less are preferable, those of 250 or less are more preferable, and those of 200 or less are more preferable. When the molecular weight of the polyvalent amine compound is 300 or less, many of the compounds are in a liquid state at room temperature, and can be easily used in a vapor phase coating method.

Among the above polyvalent amine compounds, those having a boiling point of 50° C. to 250° C. are preferable, those having a boiling point of 70° C. to 250° C. are more preferable, and those having a boiling point of 90° C. to 250° C. are even more preferable. When the boiling point of the polyvalent amine compound is 50° C. or higher, volatilization of the polyvalent amine compound during step B described below can be suppressed. Moreover, when the boiling point of the polyvalent amine compound is 250° C. or lower, the excess polyvalent amine compound can be suitably volatilized in step C described later.

Among the above polyvalent amine compounds, diamine compounds are preferred. When the polyvalent amine compound is a diamine compound, the adhesive strength (peel strength) to an inorganic substrate becomes better. Moreover, even if the laminate after being bonded to the inorganic substrate is exposed to a high temperature (for example, 500° C. for 1 hour), it is possible to further suppress an increase in the peel strength.

Among the polyvalent amine compounds, branched aliphatic polyvalent amine compounds are preferred. When the polyvalent amine compound is a branched aliphatic polyvalent amine compound, even if the compound has the same number of carbon atoms, it generally has a lower boiling point than the straight-chain aliphatic polyvalent amine compound, and can be applied to a film by a vapor phase coating method or the like. Processing can be performed more easily.

As a method for applying the polyvalent amine compound, a method of applying a solution of the polyvalent amine compound to the polymer film, a vapor phase coating method, or the like can be used. Either surface of the polymer film or both surfaces may be coated with the polyvalent amine compound.
Methods for applying the polyamine compound solution include spin coating, curtain coating, dip coating, slit die coating, gravure coating, bar Conventionally known means for applying a solution such as a coating method, a comma coating method, an applicator method, a screen printing method, and a spray coating method can be appropriately used.

The polyamine compound can also be applied by a gas phase coating method. Specifically, the polymer film is exposed to the vapor of the polyamine compound, that is, the polyamine compound in a substantially gaseous state. Form. The vapor of the polyamine compound can be obtained by heating the polyamine compound in a liquid state to a temperature from room temperature (25° C.) to about the boiling point of the polyamine compound.
The environment in which the polyvalent amine compound is heated may be under pressure, normal pressure or reduced pressure, but is preferably under normal pressure or under reduced pressure in order to promote vaporization of the polyvalent amine compound.
The exposure time of the polymer film to the polyvalent amine compound is not particularly limited, but is preferably 20 hours or less, more preferably 60 minutes or less, still more preferably 15 minutes or less, and most preferably 1 minute or less.
The temperature of the polymer film during exposure to the polyamine compound is controlled to an appropriate temperature between -50°C and 200°C depending on the type of the polyamine compound and the desired degree of surface treatment. preferably.

<Process B>
In step B, the heat-resistant polymer film coated with the polyvalent amine compound is kept within the range of 0°C or higher and lower than 60°C. The holding temperature in step B is more preferably 10°C or higher and lower than 55°C, and further preferably 20°C or higher and lower than 50°C.
The retention time in step B is preferably 30 minutes to 180 minutes, more preferably 45 minutes to 150 minutes, even more preferably 60 minutes to 120 minutes.

<Process C>
In step C, the polymer film after step B is held within a range of 60° C. or higher and 250° C. or lower. The holding temperature in step C is more preferably 70°C or higher and lower than 220°C, and more preferably 90°C or higher and lower than 200°C.
The retention time in step C is preferably 10 seconds to 5 minutes, more preferably 10 seconds to 2 minutes, and even more preferably 30 seconds to 1 minute.

By performing the step B and the step C, a polymer film suitably surface-treated with a polyvalent amine compound can be obtained.

<Method for producing a laminate in which an inorganic substrate and a polymer film are bonded together>
Next, a method for manufacturing a laminate in which an inorganic substrate and a polymer film are bonded using the polymer film will be described.

First, an inorganic substrate as a support and the polymer film are prepared.

<Inorganic substrate>
The inorganic substrate may be a plate-shaped substrate that can be used as a substrate made of an inorganic substance. , semiconductor wafers, and metal composites include laminates of these, those in which these are dispersed, and those in which these fibers are contained.

Examples of the glass plate include quartz glass, high silicate glass (96% silica), soda lime glass, lead glass, aluminoborosilicate glass, borosilicate glass (Pyrex (registered trademark)), borosilicate glass (no alkali), Borosilicate glass (microsheet), aluminosilicate glass, etc. are included. Among these, those having a coefficient of linear expansion of 5 ppm/K or less are desirable. "EAGLE", "AN100" manufactured by Asahi Glass Co., Ltd., "OA10" manufactured by Nippon Electric Glass Co., Ltd., "AF32" manufactured by SCHOTT Co., Ltd., and the like are preferable.

Examples of the semiconductor wafer include, but are not limited to, silicon wafer, germanium, silicon-germanium, gallium-arsenide, aluminum-gallium-indium, nitrogen-phosphorus-arsenic-antimony, SiC, InP (indium phosphide), InGaAs, GaInNAs, Wafers of LT, LN, ZnO (zinc oxide), CdTe (cadmium telluride), ZnSe (zinc selenide), and the like can be mentioned. Among them, the wafer preferably used is a silicon wafer, and particularly preferably a mirror-polished silicon wafer having a size of 8 inches or more.

The metals include single element metals such as W, Mo, Pt, Fe, Ni, and Au, and alloys such as Inconel, Monel, Nimonic, carbon copper, Fe—Ni system Invar alloys, and Super Invar alloys. In addition to these metals, multi-layer metal plates obtained by adding other metal layers and ceramic layers are also included. In this case, if the overall coefficient of linear expansion (CTE) with the additional layer is low, Cu, Al, etc. may also be used for the main metal layer. The metal used for the additional metal layer is limited as long as it has properties such as strong adhesion to the polymer film, no diffusion, good chemical resistance and heat resistance. Suitable examples include Cr, Ni, TiN, Mo-containing Cu, etc., although they are not specific.

It is desirable that the planar portion of the inorganic substrate be sufficiently flat. Specifically, the PV value of surface roughness is 50 nm or less, more preferably 20 nm or less, still more preferably 5 nm or less. If it is coarser than this, the peel strength between the polymer film layer and the inorganic substrate may be insufficient.
Although the thickness of the inorganic substrate is not particularly limited, the thickness is preferably 10 mm or less, more preferably 3 mm or less, and even more preferably 1.3 mm or less from the viewpoint of handleability. Although the lower limit of the thickness is not particularly limited, it is preferably 0.07 mm or more, more preferably 0.15 mm or more, and still more preferably 0.3 mm or more.

The polyamine compound layer may be formed also on the inorganic substrate by applying and drying the polyamine compound. The method of applying the polyvalent amine compound onto the inorganic substrate can be the same as in step A above. However, unlike the case of surface-treating a polymer film with a polyvalent amine compound, there is no need for the step of holding the film at a predetermined temperature as in the steps B and C, and drying is performed by a conventionally known method. Just do it. This is because basically no chemical reaction occurs between the inorganic substrate and the polyvalent amine compound.

Next, the surface of the polymer film and the inorganic substrate are pressed and heated to bond them together. A laminate is thus obtained.

The pressurized heat treatment may be performed, for example, under atmospheric pressure or in a vacuum by pressing, laminating, roll laminating, or the like while heating. A method of pressurizing and heating in a flexible bag can also be applied. From the viewpoint of improving productivity and reducing processing costs brought about by high productivity, press or roll lamination in an air atmosphere is preferred, and a method using rolls (roll lamination, etc.) is particularly preferred.

The pressure during the pressurized heat treatment is preferably 1 MPa to 20 MPa, more preferably 3 MPa to 10 MPa. When the pressure is 20 MPa or less, damage to the inorganic substrate can be suppressed. Further, when the pressure is 1 MPa or more, it is possible to prevent the occurrence of non-adhesive portions and insufficient adhesion. The temperature for the pressurized heat treatment is preferably 150°C to 400°C, more preferably 250°C to 350°C. When the polymer film is a polyimide film, if the temperature is too high, the polyimide film may be damaged, and if the temperature is too low, the adhesion tends to be weak.
The pressurized heat treatment can be performed in an atmosphere of atmospheric pressure as described above, but is preferably performed in a vacuum in order to obtain a stable peel strength over the entire surface. At this time, the degree of vacuum obtained by a normal oil rotary pump is sufficient, and a degree of vacuum of about 10 Torr or less is sufficient.
As an apparatus that can be used for pressure heating treatment, for example, "11FD" manufactured by Imoto Seisakusho Co., Ltd. can be used for pressing in a vacuum, and a roll type film laminator in a vacuum or a vacuum is used. For vacuum lamination using a film laminator or the like that applies pressure to the entire glass surface at once with a thin rubber film, for example, "MVLP" manufactured by Meiki Seisakusho Co., Ltd. can be used.

The pressurization and heat treatment can be performed separately into a pressurization process and a heating process. In this case, first, the polymer film and the inorganic substrate are pressurized (preferably about 0.2 to 50 MPa) at a relatively low temperature (for example, less than 120°C, more preferably 95°C or less) to ensure close contact between the two. Then, at low pressure (preferably less than 0.2 MPa, more preferably 0.1 MPa or less) or normal pressure at relatively high temperature (for example, 120 ° C. or higher, more preferably 120 to 250 ° C., more preferably 150 to 230 ° C. ), the chemical reaction at the adhesion interface is promoted, and the polymer film and the inorganic substrate can be laminated.

As described above, a laminate in which the inorganic substrate and the polymer film are bonded together can be obtained.

The laminate preferably has a 90° peel strength A between the inorganic substrate and the polymer film of 0.05 N/cm or more, more preferably 0.1 N/cm It is more preferable to be above. The 90° peel strength A is preferably 0.25 N/cm or less, more preferably 0.2 N/cm or less. When the 90° peel strength A is 0.05 N/cm or more, it is possible to prevent the polymer film from peeling off from the inorganic substrate before or during device formation. Further, when the 90° peel strength A is 0.25 N/cm or less, the inorganic substrate and the polymer film are easily peeled off after device formation. That is, when the 90° peel strength A is 0.25 N/cm or less, even if the peel strength between the inorganic substrate and the polymer film slightly increases during device formation, the two can be easily peeled off. .

The measurement conditions for the 90° peel strength A are as follows.
The polyimide film is peeled off from the inorganic substrate at an angle of 90°.
Measurement is performed 5 times, and the average value is taken as the measured value.
Measurement temperature; room temperature (25°C)
Peeling speed; 100mm/min
Atmosphere; Atmospheric measurement sample width; 1 cm
More specifically, according to the method described in Examples.

After the laminate was heat-treated at 200° C. for 1 hour in an air atmosphere and further heated at 500° C. for 1 hour in a nitrogen atmosphere, the 90° peel strength B between the inorganic substrate and the polymer film was 0.5 N. /cm or less, more preferably 0.3 N/cm or less, and even more preferably 0.2 N/cm or less.
The 90° peel strength B is preferably 0.05 N/cm or more, more preferably 0.1 N/cm or more. When the 90° peel strength B is 0.5 N/cm or less, the inorganic substrate and the polymer film are easily peeled off after device formation. Further, when the 90° peel strength B is 0.05 N/cm or more, it is possible to prevent peeling between the inorganic substrate and the polymer film at an unintended stage such as during device formation.

The conditions for measuring the 90° peel strength B are the same as the conditions for measuring the 90° peel strength A.

<Method for manufacturing flexible electronic device>
When the laminate is used, an electronic device is formed on the polymer film of the laminate using existing equipment and processes for manufacturing electronic devices, and the polymer film is peeled off from the laminate to form a flexible electronic device. can be made.
In this specification, the electronic device means an electronic circuit including a wiring board having a single-sided, double-sided, or multilayer structure responsible for electrical wiring, active elements such as transistors and diodes, and passive devices such as resistors, capacitors, inductors, etc. Sensor elements that sense pressure, temperature, light, humidity, etc., biosensor elements, light emitting elements, liquid crystal displays, electrophoretic displays, image display elements such as self-luminous displays, wireless and wired communication elements, computing elements, memory elements, Refers to MEMS elements, solar cells, thin film transistors, and the like.

In the device structure manufacturing method of the present specification, after forming a device on the polymer film of the laminate produced by the method described above, the polymer film is peeled off from the inorganic substrate.

The method of peeling the polymer film with the device from the inorganic substrate is not particularly limited, but a method of rolling it up from the edge with tweezers or the like, making a cut in the polymer film, and attaching an adhesive tape to one side of the cut portion. A method of rolling up from the tape portion later, a method of vacuum-sucking one side of the notched portion of the polymer film and then rolling up from that portion, and the like can be employed. When peeling, if the cut portion of the polymer film bends with a small curvature, stress is applied to the device at that portion, which may destroy the device. is desirable. For example, it is desirable to wind the film while winding it on a roll having a large curvature, or to roll it using a machine configured so that the roll having a large curvature is positioned at the peeling portion.
The method of cutting the polymer film includes a method of cutting the polymer film with a cutting tool such as a knife, a method of cutting the polymer film by relatively scanning a laser and a laminate, and a method of cutting the polymer film with a water jet. There are a method of cutting the polymer film by relatively scanning the laminate, a method of cutting the polymer film while slightly cutting into the glass layer with a semiconductor chip dicing device, and the like, but the method is not particularly limited. do not have. For example, in adopting the above-described method, it is also possible to appropriately adopt techniques such as superimposing ultrasonic waves on the cutting tool or adding reciprocating motion or vertical motion to improve cutting performance.
It is also useful to attach another reinforcing base material in advance to the part to be peeled off, and peel off the entire reinforcing base material. If the flexible electronic device to be peeled is the backplane of the display device, it is also possible to obtain a flexible display device by first attaching the frontplane of the display device, integrating them on the inorganic substrate, and then peeling them off at the same time. be.

Hereinafter, the present invention will be described in detail using examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[Production Example 1 (production of polyamic acid solution)]
After purging the interior of a reaction vessel equipped with a nitrogen introduction tube, a thermometer, and a stirring bar, 223 parts by mass of 5-amino-2-(p-aminophenyl)benzoxazole (DAMBO), N, 4416 parts by mass of N-dimethylacetamide was added and dissolved completely. Next, along with 217 parts by mass of pyromellitic dianhydride (PMDA), a colloidal silica dispersion (manufactured by Nissan Chemical Industries, Ltd., product name: DMAc-ST-ZL), silica (lubricant) is a polymer in the polyamic acid solution. It was added so as to be 0.12% by mass with respect to the total solid content, and stirred at a reaction temperature of 25° C. for 24 hours to obtain a viscous polyamic acid solution V1.

[Production Example 2 (production of polyamic acid solution)]
Polyamic acid solution V2 was obtained in the same manner as in Production Example 1, except that the colloidal silica dispersion was not added.

[Production Example 3 (Preparation of polyimide film)]
The polyamic acid solution V2 obtained above was coated on the smooth surface (non-slip material surface) of a long polyester film ("A-4100" manufactured by Toyobo Co., Ltd.) with a width of 1050 mm using a comma coater, and the final film thickness (imide The film thickness after curing) is about 5 μm, and then the polyamic acid solution V1 is applied using a slit die so that the final film thickness is 38 μm (including the thickness of the polyamic acid solution V2). After drying at 105° C. for 25 minutes, it was peeled off from the polyester film to obtain a self-supporting polyamic acid film with a width of 920 mm.
Next, the resulting self-supporting polyamic acid film was imidized by heat treatment by stepwise heating in a temperature range of 180° C. to 495° C. using a pin tenter. Specifically, heat treatment was performed at 180° C. for 5 minutes in the first stage, 220° C. for 5 minutes in the second stage, and 495° C. for 10 minutes in the third stage. Next, the portions held by the pins at both ends were cut off with a slit to obtain a long polyimide film (1000 m roll) with a width of 850 mm. The thickness of the actually obtained polyimide film was 36 μm.

(Example 1)
2-methyl 1,5-diaminopentane (manufactured by Tokyo Chemical Industry Co., Ltd., molecular weight: 116.21, boiling point: 78° C./11 mmHg (boiling point at normal pressure: 193.0° C. (estimated value))) as an amine compound An amine dilution was prepared in isopropanol to contain 1% by weight. The polyimide film produced in Production Example 3 was placed on a spin coater (MSC-500S, manufactured by Japan Create Co., Ltd.), and the number of revolutions was raised to 2000 rpm for 10 seconds to apply the amine diluted solution. After that, it was left in an atmosphere of 40° C. for 60 minutes. The step of leaving in the atmosphere of 40° C. for 60 minutes corresponds to the step B of the present invention. Next, the polyimide film was placed on a hot plate heated to 100° C. with the amine compound coated surface facing upward, and heated for 1 minute to obtain a film according to Example 1. The step of heating at 100° C. for 1 minute corresponds to step C of the present invention.

(Example 2)
A film according to Example 2 was obtained in the same manner as in Example 1, except that the amine compound contained in the amine diluent was changed to hexamethylenediamine (HMDA).

(Example 3)
A film according to Example 3 was obtained in the same manner as in Example 1, except that the amine compound contained in the amine diluent was changed to ethylenediamine.

(Example 4)
A film according to Example 4 was obtained in the same manner as in Example 1, except that the amine compound contained in the amine diluent was changed to putrescine.

(Example 5)
A film according to Example 5 was obtained in the same manner as in Example 1, except that the amine compound contained in the amine diluent was changed to triethylenetetramine.

(Example 6)
A film according to Example 6 was obtained in the same manner as in Example 1, except that the amine compound contained in the amine diluent was changed to 1,3,5-pentanetriamine.

(Example 7)
A suction bottle connected to the chamber was filled with 100 parts by mass of 2-methyl-1,5-diaminopentane as an amine compound, and left standing on a water bath at 40°C. By closing the suction bottle in such a state that instrumentation air can be introduced from above, a state was created in which the vapor of the amine compound can be introduced into the chamber at 25°C. Then, the polyimide film produced in Production Example 3 was held horizontally in the chamber, and the chamber was closed. Instrumentation air was then introduced at 25 L/min, and the chamber (25° C.) filled with amine compound vapor was held for 120 minutes to expose the polyimide film to the amine compound vapor. The step of holding at 25° C. for 120 minutes under the vapor of the diamine compound corresponds to step B of the present invention.

Next, the film was taken out and heated at 120° C. for 30 seconds to obtain a film according to Example 6. The step of heating at 120° C. for 30 seconds corresponds to step C of the present invention.

(Example 8)
A film according to Example 7 was obtained in the same manner as in Example 7, except that the amine compound contained in the amine diluent was changed to hexamethylenediamine (HMDA).

(Example 9)
A film according to Example 8 was obtained in the same manner as in Example 7, except that the amine compound contained in the amine diluent was changed to ethylenediamine.

(Example 10)
A film according to Example 9 was obtained in the same manner as in Example 7, except that the amine compound contained in the amine diluent was changed to putrescine.

(Example 11)
A film according to Example 10 was obtained in the same manner as in Example 7, except that the amine compound contained in the amine diluent was changed to triethylenetetramine.

(Example 12)
A film according to Example 12 was obtained in the same manner as in Example 7 except that the amine compound contained in the amine diluent was changed to 1,3,5-pentanetriamine.

(Comparative example 1)
The polyimide film produced in Production Example 3 was used as the film according to Comparative Example 1. That is, the film according to Comparative Example 1 is a film to which no amine diluent is applied.

(Comparative example 2)
A film according to Comparative Example 2 was obtained in the same manner as in Example 1 except that a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBM-903) was applied instead of the amine diluent.

<Measurement of nitrogen content>
An X-ray photoelectron spectrometer (ESCA, manufactured by Thermo Fisher Scientific, product name: K-Alpha ⁺ ) was used. First, the nitrogen content A of the surface of the films produced in Examples and Comparative Examples was measured. Next, after performing argon etching up to the central portion in the thickness direction of the film, the nitrogen content B of that portion was measured. Further, the difference between nitrogen content B and nitrogen content A (nitrogen content difference) was calculated by "(nitrogen content A) - (nitrogen content B)". Table 1 shows the results.
The details of the elemental analysis method by ESCA are as follows.
<Measurement conditions>
Excitation X-ray: Monochrome Al Kα ray X-ray output: 12 kV, 6 mA
Photoelectron escape angle: 90°
Spot size: 400 μmφ
Pass energy: 50 eV (narrow scan), 200 eV (all element scan)
Step: 0.1 eV (narrow scan), 1 eV (all element scan)

<Production of laminate>
A laminate was obtained by laminating the films of Examples and Comparative Examples and a glass substrate. A laminator manufactured by MCK was used for the lamination, and the lamination conditions were a pressure of 0.8 MPa and a temperature of 25°C. The films of Examples 1 to 10 were laminated so that the amine-treated surface of the film faced the glass substrate. The film of Comparative Example 2 was laminated so that the silane coupling agent-treated surface of the film faced the glass substrate.

<Measurement of 90° peel strength A after heat treatment at 200°C for 1 hour>
The layered product obtained in the production of the layered product was heat-treated at 200° C. for 1 hour in an air atmosphere. After that, the 90° peel strength A between the glass substrate and the film was measured. Table 1 shows the results.
The measurement conditions for the 90° peel strength A are as follows.
The film is peeled off at an angle of 90° to the glass substrate.
Measurement is performed 5 times, and the average value is taken as the measured value.
Measuring device; Peel tester (Japan Keisoku System Co., Ltd., JSV-H1000)
Measurement temperature; room temperature (25°C)
Peeling speed; 100mm/min
Atmosphere; Atmospheric measurement sample width; 1 cm

<Measurement of 90° peel strength B after heat treatment at 200°C for 1 hour and further heating at 500°C for 1 hour>
The layered product obtained in the production of the layered product was heat-treated at 200° C. for 1 hour in an air atmosphere. Furthermore, it was heated at 500° C. for 1 hour in a nitrogen atmosphere. After that, the 90° peel strength B between the glass substrate and the film was measured. Table 1 shows the results.
The measurement conditions for the 90° peel strength B were the same as those for the 90° peel strength A.

Claims (7)

A heat-resistant polymer film having a surface-treated first surface,
Having a layer containing a reaction product of a polyvalent amine compound and a heat-resistant polymer film,
The heat-resistant polymer film is a polyimide film,
A heat-resistant polymer film, wherein the nitrogen content of the first surface is 0.45 atom % or more higher than the nitrogen content of the central portion in the thickness direction of the heat-resistant polymer film. A method for producing a heat-resistant polymer film according to claim 1,
A step A of applying a polyvalent amine compound to a polyimide film, which is a heat-resistant polymer film;
After the step A, a step B of maintaining the heat-resistant polymer film within a range of 0° C. or more and less than 60° C.;
After the step B, a step C of holding the heat-resistant polymer film within a range of 60° C. or higher and 250° C. or lower;
have death,
The holding time in the step B is 30 minutes to 180 minutes, and the holding time in the step C is 10 seconds to 5 minutes. A method for producing a surface-treated heat-resistant polymer film, characterized in that: 3. The method for producing a surface-treated heat-resistant polymer film according to claim 2, wherein the polyvalent amine compound has a molecular weight of 300 or less. 4. The method for producing a surface-treated heat-resistant polymer film according to claim 2, wherein the polyamine compound has a boiling point of 50[deg.] C. or more and 250[deg.] C. or less. 5. The method for producing a surface-treated heat-resistant polymer film according to any one of claims 2 to 4, wherein the polyamine compound is a diamine compound. 6. The method for producing a surface-treated heat-resistant polymer film according to any one of claims 2 to 5, wherein the polyamine compound is a branched aliphatic polyamine compound. A heat-resistant polymer film roll comprising the heat-resistant polymer film according to claim 1 wound into a roll.