WO2023189719A1

WO2023189719A1 - Laminate and method for producing laminate

Info

Publication number: WO2023189719A1
Application number: PCT/JP2023/010563
Authority: WO
Inventors: 俊介市村; 啓介松尾
Original assignee: 東洋紡株式会社
Priority date: 2022-03-29
Filing date: 2023-03-17
Publication date: 2023-10-05
Also published as: JPWO2023189719A1; TW202346093A

Abstract

Provided is a laminate in which a first substrate, a silane coupling agent layer, and a second substrate are laminated in this order, wherein: [B1] ≥ [A1] is satisfied when A1 is the number of circular floats having a diameter of 0.5 mm or more prior to heating per area of 2,500 cm² and B1 is the number of circular floats having a diameter of 0.5 mm or more after heating at 200°C for one hour; [B2] ≥ [A2] is satisfied when A2 is the average diameter of A1 floats and B2 is the average diameter of B1 floats; B1 is 20 or fewer; and B2 is 4.0 mm or less.

Description

Laminated body and method for manufacturing the laminated body

The present invention relates to a laminate and a method for manufacturing a laminate.

In recent years, with the aim of making functional elements such as semiconductor elements, MEMS elements, and display elements lighter, smaller, thinner, and more flexible, technological development has been actively conducted to form these elements on polymer films. In other words, the base materials for electronic components such as information and communication equipment (broadcasting equipment, mobile radio, portable communication equipment, etc.), radar, high-speed information processing equipment, etc. have traditionally been heat-resistant and capable of handling signals of information and communication equipment. Ceramic, which can handle high frequency bands (reaching the GHz band), has been used, but ceramics are not flexible and are difficult to make thin, so they have the disadvantage of limiting the fields in which they can be applied. A polymer film is used as the substrate.

Methods for producing a laminate in which functional elements are formed on the polymer film include (1) a method of laminating a metal layer on a resin film via an adhesive or a pressure-sensitive adhesive; (2) a method of laminating a metal layer on a resin film; (3) A method of applying a varnish for forming a resin film on a polymer film or metal layer, drying it, and then laminating it with a metal layer or polymer film; (4) (5) A method of forming a conductive material on a resin film by screen printing or sputtering is known. Furthermore, when producing a multilayered product having three or more layers, various combinations of the above-mentioned methods are used.

On the other hand, in the process of forming the laminate, the laminate is often exposed to high temperatures. For example, in the production of low-temperature polysilicon thin film transistors, heating to about 450°C may be necessary for dehydrogenation, and in the production of hydrogenated amorphous silicon thin films, temperatures of about 200 to 300°C may be applied to the film. There is. Furthermore, when the laminate is used for heater applications or power semiconductor applications, it will be exposed to temperatures of about 150 to 500° C. for a long time. Therefore, the polymer film constituting the laminate is required to have heat resistance, but as a practical matter, there are only a limited number of polymer films that can withstand practical use in such a high temperature range. In addition, it is conceivable to use a pressure-sensitive adhesive or adhesive as described above to bond the polymer film to the metal layer, but in this case, the bonding surface between the polymer film and the metal layer (i.e., the bonding surface for bonding) Heat resistance is also required for adhesives and adhesives. However, ordinary adhesives and pressure-sensitive adhesives for bonding do not have sufficient heat resistance, and during the process or actual use, the polymer film may peel off (i.e., a decrease in peel strength), blisters may form, and carbide may form. It cannot be applied due to problems such as the occurrence of In particular, when exposed to high temperatures for a long period of time or used at high temperatures for a long period of time, there is a problem that the peel strength decreases significantly and the product becomes unusable.

In view of these circumstances, we have developed a laminate of a polymer film and an inorganic substrate that has excellent heat resistance, is strong, and can be made into a thin film for manufacturing so-called flexible electronic devices in which functional elements are formed on a flexible substrate. A laminate in which a polyimide film is bonded to an inorganic substrate via a silane coupling agent has been proposed (for example, see Patent Document 1).

JP 2021-2622 Publication

In the above-mentioned laminate, by interposing a layer containing a silane coupling agent (hereinafter also referred to as a silane coupling agent layer) between the inorganic substrate and the heat-resistant polymer film, the inorganic substrate is removed before or during device formation. It is intended to prevent the inorganic substrate from peeling off from the polyimide film, and to easily peel the inorganic substrate from the polyimide film after device formation.

However, even when using a laminate in which a silane coupling agent layer is interposed between an inorganic substrate and a heat-resistant polymer film, the laminate produced by coating an aqueous silane coupling agent solution has When heated at high temperatures, there was a problem in that the adhesive strength may partially decrease.
Additionally, the present inventors have discovered that the same problem occurs not only in the case of a laminate of an inorganic substrate and a heat-resistant polymer film, but also when two substrates are bonded together via a silane coupling agent layer. Ta.

The present invention has been made in view of the above-mentioned problems. That is, an object of the present invention is to provide a laminate that has sufficient adhesive strength even after being heated at high temperatures. Another object of the present invention is to provide a method for manufacturing the laminate.

In view of this situation, the present inventors conducted extensive research. As a result, if the number of circular floats after heating has not increased significantly compared to before heating, and the average diameter of circular floats after heating has not increased significantly compared to before heating. discovered that the adhesive strength did not decrease significantly even after heating, and completed the present invention.

That is, the laminate according to the present invention is
A laminate in which a first substrate, a silane coupling agent layer, and a second substrate are laminated in this order,
When the number of circular floats with a diameter of 0.5 mm or more before heating per area of 2,500 cm ² is A1, and the number of circular floats with a diameter of 0.5 mm or more after heating at 200 ° C for 1 hour is B1. , [B1]≧[A1],
When the average diameter of the A1 floats is A2, and the average diameter of the B1 floats is B2, [B2]≧[A2] is satisfied,
The number of B1 is 20 or less,
It is characterized in that the B2 is 4.0 mm or less.

Since [B1]≧[A1] is satisfied and B1 is 20 or less, it can be said that the number of floats after heating has not increased significantly compared to before heating. Furthermore, since [B2]≧[A2] is satisfied and B2 is 4.0 mm or less, it can be said that the diameter of the float after heating has not increased significantly compared to before heating.
Thus, according to the above configuration, the number of floats after heating does not increase significantly compared to before heating, and the diameter of the floats after heating does not increase significantly compared to before heating. Therefore, the adhesive area is secured even after heating. Therefore, the adhesive strength does not decrease significantly even after heating.

In the configuration, the first substrate is a heat-resistant polymer film,
Preferably, the second substrate is a metal substrate.

When the first substrate is a heat-resistant polymer film and the second substrate is a metal substrate, for example, with the heat-resistant polymer film adhered to the metal substrate, a functional element is attached on the heat-resistant polymer film. It becomes possible to form electronic devices such as Furthermore, by forming a circuit on the metal substrate itself by etching or the like, it becomes possible to use it for heater applications such as flexible heaters. Further, a laminate in which a heat-resistant polymer film and a metal substrate are bonded together can be used for power semiconductor applications.

In the above structure, it is preferable that the silane coupling agent constituting the silane coupling agent layer has an amino group.

If the silane coupling agent has an amino group, it will bond to the reactive groups on the first substrate and the second substrate when organic materials are used as the first substrate and the second substrate. As a result, the adhesive strength between the first substrate and the second substrate can be increased. Furthermore, the stability of the silane coupling agent in an aqueous solution is also improved.

Further, the method for manufacturing a laminate according to the present invention includes:
Step A of preparing a first substrate and a second substrate;
Step B of preparing a mixed solution containing a silane coupling agent and water and having an alcohol content of 1 mol% or less relative to the silane coupling agent;
Step C of supplying the mixed solution onto the first substrate and/or the second substrate, and
The method is characterized by including a step D of bonding the first substrate and the second substrate together after the mixed solution is supplied.

According to the configuration, the content of alcohol in the mixed solution is 1 mol % or less based on the silane coupling agent. Therefore, when the first substrate and the second substrate are bonded together after the mixed solution has been supplied, the amount of alcohol trapped in the laminate is small. As a result, the amount of floating can be reduced. As a result, the adhesive strength of the obtained laminate does not decrease significantly even after heating.
This point will be explained in detail.
The present inventors have discovered that the amount of floating can be suitably reduced by setting the alcohol content in the mixed solution to 1 mol % or less relative to the silane coupling agent.
Specifically, the present inventors discovered the following.
When a silane coupling agent is hydrolyzed, a silanol group is generated. The silanol group will bond with a reactive group (eg, OH group) on the first substrate and/or the second substrate. Here, when the silane coupling agent is hydrolyzed to produce silanol groups, alcohol is produced as a by-product.
Conventionally, in the production of laminates, even after the first substrate and the second substrate are bonded, hydrolysis of the silane coupling agent proceeds to some extent, and by-product alcohol is trapped within the laminate. was. The present inventors have discovered that this alcohol is the cause of floating.
Furthermore, the present inventors previously hydrolyzed the silane coupling agent to some extent before bonding the first substrate and the second substrate, and prepared a solution containing the silane coupling agent (silane coupling agent). It has been found that by removing alcohol in advance from the solution (for forming the agent layer), the amount of alcohol trapped within the laminate can be reduced.
From the above, when the content of alcohol in the mixed solution is set to 1 mol % or less with respect to the silane coupling agent, the amount of floating can be suitably reduced.
This is also clear from the results of Examples.

In the above configuration, it is preferable that the step B includes a step of removing alcohol from a liquid containing a silane coupling agent, water, and alcohol.

By carrying out the step of removing alcohol from a liquid containing a silane coupling agent, water, and alcohol, a mixed solution in which the alcohol content is 1 mol % or less relative to the silane coupling agent can be suitably obtained.

In the above configuration, the ^silane coupling agent in the mixed liquid is: When Y is the total ratio of Si having the following T1 structure, the following T2 structure, and the following T3 structure, it is preferable that X/Y is 81 or more.
However, in the following T0 structure, the following T1 structure, the following T2 structure, and the following T3 structure, Z is a divalent alkyl chain represented by C _n H _2n , and W is a monovalent alkyl chain represented by C _m H _2m+1 . It is an alkyl group or a hydrogen atom (where n is an integer of 1 or more and 10 or less, and m is an integer of 1 or more and 10 or less).

When the X/Y is 81 or more, the hydrolysis of the silane coupling agent has progressed to some extent, resulting in an oligomer state and silanol groups also being generated. The silanol group will bond with a reactive group (eg, OH group) on the first substrate and/or the second substrate. As a result, the amount of floating can be further reduced.

According to the present invention, it is possible to provide a laminate in which the adhesive strength does not partially decrease significantly even after high-temperature heating. Furthermore, a method for manufacturing the laminate can be provided.

Hereinafter, embodiments of the present invention will be described.

<Laminated body>
The laminate according to this embodiment is
A laminate in which a first substrate, a silane coupling agent layer, and a second substrate are laminated in this order,
When the number of circular floats with a diameter of 0.5 mm or more before heating per area of 2,500 cm ² is A1, and the number of circular floats with a diameter of 0.5 mm or more after heating at 200 ° C for 1 hour is B1. , [B1]≧[A1],
When the average diameter of the A1 floats is A2, and the average diameter of the B1 floats is B2, [B2]≧[A2] is satisfied,
The number of B1 is 20 or less,
Said B2 is 4.0 mm or less.
As used herein, "per 2,500 ^cm2 area" means "per 50 cm x 50 cm square."

Since [B1]≧[A1] is satisfied and B1 is 20 or less, it can be said that the number of floats after heating has not increased significantly compared to before heating. Furthermore, since [B2]≧[A2] is satisfied and B2 is 4.0 mm or less, it can be said that the diameter of the float after heating has not increased significantly compared to before heating.
Thus, according to the laminate, the number of floats after heating does not increase significantly compared to before heating, and the diameter of the floats after heating increases significantly compared to before heating. Therefore, the adhesive area is secured even after heating. Therefore, the adhesive strength does not decrease significantly even after heating.

[B1]≧[A1], [B2]≧[A2], the number of B1 is 20 or less, and the number of B2 is 4.0 mm or less, for example, when forming a silane coupling agent layer, as described later. This can be achieved by appropriately adjusting a mixed solution of.

[A1] is preferably 10 or less, more preferably 9 or less, even more preferably 5 or less. [A1] is preferably smaller, but may be, for example, 0 or more, or 1 or more.

The above [B1] is preferably 15 or less, more preferably 7 or less. [B1] is preferably smaller, but may be, for example, 0 or more, or 1 or more.

The above [A2] is preferably 2.0 mm or less, more preferably 1.0 mm or less. [A2] is preferably smaller, for example, 0.5 mm or more.

The above [B2] is preferably 4.0 mm or less, more preferably 2.0 mm or less. [B2] is preferably smaller, for example, 0.5 mm or more.

In the laminate, [B1]/[A1] is preferably 1.5 or less, and [B2]/[A2] is preferably 2.0 or less.

When the above [B1]/[A1] is 1.5 or less, it can be said that the number of floats after heating does not increase significantly compared to before heating. Moreover, when the above-mentioned [B2]/[A2] is 2.0 or less, it can be said that the diameter of the float after heating does not increase significantly compared to before heating.

The above [B1]/[A1] and the above [B2]/[A2] can be achieved, for example, by appropriately adjusting the mixed solution when forming the silane coupling agent layer, as described below. I can do it.

The above [B1]/[A1] is preferably 1.5 or less, more preferably 1.2 or less. [B1]/[A1] is preferably smaller, and is, for example, 1 or more.

The above [B2]/[A2] is preferably 1.8 or less, more preferably 1.5 or less. [B2]/[A2] is preferably smaller, and is, for example, 1 or more.

Examples of the first substrate include a heat-resistant polymer film and an inorganic substrate. Examples of the second substrate include a heat-resistant polymer film and an inorganic substrate. The combination of the first substrate and the second substrate is not particularly limited.

As a combination of the first substrate and the second substrate, (a) both the first substrate and the second substrate may be inorganic substrates, and (b) the first substrate may be an inorganic substrate. Both the substrate and the second substrate may be heat-resistant polymer films, and (c) one of the first substrate and the second substrate is an inorganic substrate, and the other is a heat-resistant polymer film. It may be.
Among the combinations of the first substrate and the second substrate, it is particularly preferable that the first substrate is a heat-resistant polymer film and the second substrate is a metal substrate. When the first substrate is a heat-resistant polymer film and the second substrate is a metal substrate, for example, with the heat-resistant polymer film adhered to the metal substrate, a functional element is attached on the heat-resistant polymer film. It becomes possible to form electronic devices such as Furthermore, by forming a circuit on the metal substrate itself by etching or the like, it becomes possible to use it for heater applications such as flexible heaters. Further, a laminate in which a heat-resistant polymer film and a metal substrate are bonded together can be used for power semiconductor applications.

<Silane coupling agent layer>
Although not particularly limited, the silane coupling agent layer according to the present embodiment is formed by supplying a mixed solution containing a silane coupling agent and water onto the first substrate and/or the second substrate. The content of alcohol in the mixed solution is preferably 1 mol % or less based on the silane coupling agent.
When a silane coupling agent is hydrolyzed, a silanol group is generated. The silanol group will bond with a reactive group (eg, OH group) on the first substrate and/or the second substrate. Here, when the silane coupling agent is hydrolyzed to produce silanol groups, alcohol is produced as a by-product.
Conventionally, in the production of laminates, even after the first substrate and the second substrate are bonded, hydrolysis of the silane coupling agent proceeds to some extent, and by-product alcohol is trapped within the laminate. was. The present inventors have discovered that this alcohol is the cause of floating.
In this embodiment, before bonding the first substrate and the second substrate, the silane coupling agent is first hydrolyzed to some extent, and a liquid containing the silane coupling agent (a silane coupling agent layer is formed) is used. Alcohol is removed from the solution in advance. This can reduce the amount of alcohol trapped within the laminate.
In addition, as another embodiment, a mixed solution from which alcohol has been removed in advance may be used as the mixed solution.
When the content of alcohol in the mixed solution is 1 mol% or less with respect to the silane coupling agent, [B1]≧[A1], [B2]≧[A2], the number of B1 is 20 or less, and It is easy to achieve the above B2 of 4.0 mm or less.
Further, when the content of alcohol in the mixed solution is 1 mol % or less with respect to the silane coupling agent, "the [B1]/[A1] is 1.5 or less" and "the [B2] / [A2] is 2.0 or less” is easy to achieve.
The alcohol content in the mixed solution is more preferably 0.8 mol% or less, still more preferably 0.5 mol% or less. The content of alcohol in the mixed solution is preferably as low as possible, and is, for example, 0.1 mol% or more, 0.2 mol% or more.

The thickness of the silane coupling agent layer is preferably less than 1.0 μm. Furthermore, in processes where it is desired to use as little silane coupling agent as possible, it is possible to use a silane coupling agent with a wavelength of 500 nm or less. The thickness of the silane coupling agent layer is preferably 1 nm or more from the viewpoint of adhesive strength. The thickness of the silane coupling agent layer depends on the concentration of the mixed solution, the amount supplied onto the substrates (first substrate, second substrate), and the attachment of the substrates (first substrate, second substrate). It can be adjusted by the pressure at the time of fitting.

Although the silane coupling agent contained in the mixed liquid is not particularly limited, it is preferable that the silane coupling agent is hydrolyzed to some extent and has a large proportion of oligomers.
The silane coupling agent in a monomer state before hydrolysis preferably has an amino group or an epoxy group. Specific examples of the silane coupling agent in a monomer state before hydrolysis include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane. , N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylene) den)propylamine, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltri Ethoxysilane vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxy Silane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropylmethyldiethoxysilane Roxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3 -Ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatepropyltriethoxysilane, Tris -(3-trimethoxysilylpropyl)isocyanurate, chloromethylphenethyltrimethoxysilane, chloromethyltrimethoxysilane and the like. Among these, preferred are N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)- 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, 2-(3, 4-Epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, aminophenyltrimethoxysilane, amino Examples include phenethyltrimethoxysilane, aminophenylaminomethylphenethyltrimethoxysilane, and the like. When heat resistance is required in a process, it is desirable to use an aromatic link between Si and an amino group.
When the silane coupling agent has an amino group, it bonds with the reactive groups on the first substrate and the second substrate when organic materials are used as the first substrate and the second substrate. As a result, the adhesive strength between the first substrate and the second substrate can be increased.

Other details of the mixed liquid will be explained in the section on the method for manufacturing the laminate.

<Heat-resistant polymer film (polymer film)>
The polymer film preferably has a glass transition temperature of 115°C or higher, more preferably 130°C or higher, still more preferably 145°C or higher.
Examples of the polymer film include amorphous polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polyamideimide, polyetherimide, polybenzoxazole, polyimidebenzoxazole, polyethylene naphthalate, and silicone resin. , fluororesin, liquid crystal polymer, and the like.
As the polymer film, it is particularly preferable to use a polymer film having imide bonds. Examples of polymer films having imide bonds include films of polyimide, polyamideimide, polyetherimide, polyimide benzoxazole, bismaleimide triazine, and the like.

The details of a polyimide resin film (sometimes referred to as a polyimide film), which is an example of the polymer film, will be described below. Generally, polyimide resin films are produced by applying a polyamic acid (polyimide precursor) solution obtained by reacting diamines and tetracarboxylic acids in a solvent to a support for polyimide film production, and drying it to form a green film (hereinafter referred to as green film). (also referred to as a "polyamic acid film"), and is obtained by further heat-treating the green film at a high temperature on a support for producing a polyimide film or in a state peeled from the support to perform a dehydration ring-closing reaction.

The polyamic acid (polyimide precursor) solution can be applied using conventionally known solutions such as spin coating, doctor blade, applicator, comma coater, screen printing, slit coating, reverse coating, dip coating, curtain coating, and slit die coating. Any means may be used as appropriate.

The diamines constituting the polyamic acid are not particularly limited, and aromatic diamines, aliphatic diamines, alicyclic diamines, etc. 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. When aromatic diamines having a benzoxazole structure are used, it becomes possible to exhibit not only high heat resistance but also high elastic modulus, low heat shrinkability, and low coefficient of linear expansion. Diamines may be used alone or in combination of two or more.

The aromatic diamines having a benzoxazole structure are not particularly limited, and examples thereof include 5-amino-2-(p-aminophenyl)benzoxazole, 6-amino-2-(p-aminophenyl)benzoxazole, 5-amino-2-(p-aminophenyl)benzoxazole, -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-mentioned 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'-diaminodiphenylsulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4' -diaminodiphenylsulfoxide, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 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-amino) phenoxy)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-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-amino) phenoxy)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-aminophenoxy)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-dimethylbenzyl)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-biphenoxybenzoyl)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 or all of the hydrogen atoms on the aromatic ring of the aromatic diamine are halogen atoms, carbon atoms 1 to An aromatic substituted with a halogenated alkyl group or alkoxyl group having 1 to 3 carbon atoms in which some or all of the hydrogen atoms of the alkyl group or alkoxyl group of 3 are substituted with halogen atoms. Examples include group diamines.

Examples of the aliphatic diamines include 1,2-diaminoethane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, and 1,8-diaminootane.
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 of the total diamines, more preferably 10% by mass or less, and even more preferably 5% by mass or less. It is. In other words, aromatic diamines preferably account for 80% by mass or more of the total diamines, more preferably 90% by mass or more, still more preferably 95% by mass or more.

Tetracarboxylic acids constituting polyamic acids include aromatic tetracarboxylic acids (including their acid anhydrides), aliphatic tetracarboxylic acids (including their acid anhydrides), and alicyclic tetracarboxylic acids that are commonly used in polyimide synthesis. Acids (including their acid anhydrides) can be used. When these are acid anhydrides, the number of anhydride structures in the molecule may be one or two, but those having two anhydride structures (dianhydride) are preferable. good. Tetracarboxylic acids may be used alone or in combination of two or more.

The aromatic tetracarboxylic acids are not particularly limited, but are preferably pyromellitic acid residues (that is, those having a structure derived from pyromellitic acid), and more preferably are acid anhydrides thereof. Examples of such aromatic tetracarboxylic acids include pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride, , 3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis[4-(3,4-dianhydride) Examples include carboxyphenoxy)phenyl]propanoic anhydride.
When heat resistance is important, the amount of aromatic tetracarboxylic acids is preferably 80% by mass or more of the total tetracarboxylic acids, more preferably 90% by mass or more, still more preferably 95% by mass or more.

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. Examples include 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, etc.) are preferred. Note that the alicyclic tetracarboxylic acids may be used alone or in combination of two or more.
When transparency is important, the alicyclic tetracarboxylic acids preferably account for 80% by mass or more of the total tetracarboxylic acids, more preferably 90% by mass or more, still more preferably 95% by mass or more.

The polyimide film may be a transparent polyimide film.

A colorless and transparent polyimide, which is an example of the polymer film, will be explained. Hereinafter, to avoid complexity, it will also be simply referred to as transparent polyimide. Regarding the transparency of the transparent polyimide, it is preferable that the total light transmittance is 75% or more. It is more preferably 80% or more, still more preferably 85% or more, even more preferably 87% or more, particularly preferably 88% or more. The upper limit of the total light transmittance of the transparent polyimide is not particularly limited, but for use as a flexible electronic device, it is preferably 98% or less, more preferably 97% or less. The colorless transparent polyimide in the present invention is preferably a polyimide having a total light transmittance of 75% or more.

Aromatic tetracarboxylic acids for obtaining colorless and highly transparent polyimide include 4,4'-(2,2-hexafluoroisopropylidene)diphthalic acid, 4,4'-oxydiphthalic acid, and bis(1,3- dioxo-1,3-dihydro-2-benzofuran-5-carboxylic acid) 1,4-phenylene, bis(1,3-dioxo-1,3-dihydro-2-benzofuran-5-yl)benzene-1,4 -dicarboxylate, 4,4'-[4,4'-(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(benzene-1,4-diyloxy)]dibenzene- 1,2-dicarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 4,4'-[(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis (Toluene-2,5-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(1, 4-xylene-2,5-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[4,4'-(3-oxo-1,3-dihydro-2-benzofuran-1,1- diyl)bis(4-isopropyl-toluene-2,5-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[4,4'-(3-oxo-1,3-dihydro-2- benzofuran-1,1-diyl)bis(naphthalene-1,4-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[4,4'-(3H-2,1-benzoxathiol-) 1,1-dioxide-3,3-diyl)bis(benzene-1,4-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-benzophenonetetracarboxylic acid, 4,4'-[(3H -2,1-benzoxathiol-1,1-dioxide-3,3-diyl)bis(toluene-2,5-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[(3H- 2,1-Benzoxathiol-1,1-dioxide-3,3-diyl)bis(1,4-xylene-2,5-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[ 4,4'-(3H-2,1-benzoxathiol-1,1-dioxide-3,3-diyl)bis(4-isopropyl-toluene-2,5-diyloxy)]dibenzene-1,2-dicarvone Acid, 4,4'-[4,4'-(3H-2,1-benzoxathiol-1,1-dioxide-3,3-diyl)bis(naphthalene-1,4-diyloxy)]dibenzene-1 , 2-dicarboxylic acid, 3,3',4,4'-benzophenone tetracarboxylic acid, 3,3',4,4'-benzophenone tetracarboxylic acid, 3,3',4,4'-diphenylsulfone tetracarboxylic acid acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, pyromellitic acid, 4,4'-[spiro(xanthene-9,9') -fluorene)-2,6-diylbis(oxycarbonyl)]diphthalic acid, 4,4'-[spiro(xanthene-9,9'-fluorene)-3,6-diylbis(oxycarbonyl)]diphthalic acid, etc. Examples include tetracarboxylic acids and their acid anhydrides. Among these, dianhydrides having two acid anhydride structures are preferred, particularly 4,4'-(2,2-hexafluoroisopropylidene)diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, Acid dianhydrides are preferred. Incidentally, the aromatic tetracarboxylic acids may be used alone or in combination of two or more kinds. When heat resistance is important, the amount of copolymerized aromatic tetracarboxylic acids is preferably 50% by mass or more of the total tetracarboxylic acids, more preferably 60% by mass or more, and still more preferably 70% by mass. The content is more preferably 80% by mass or more, particularly preferably 90% by mass or more, and may be 100% by mass.

Examples of alicyclic tetracarboxylic acids include 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,3,4-cyclohexanetetracarboxylic acid, 1 , 2,4,5-cyclohexanetetracarboxylic acid, 3,3',4,4'-bicyclohexyltetracarboxylic acid, bicyclo[2,2,1]heptane-2,3,5,6-tetracarboxylic acid, Bicyclo[2,2,2]octane-2,3,5,6-tetracarboxylic acid, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid, tetrahydroanthracene -2,3,6,7-tetracarboxylic acid, tetradecahydro-1,4:5,8:9,10-trimethanoanthracene-2,3,6,7-tetracarboxylic acid, decahydronaphthalene-2 , 3,6,7-tetracarboxylic acid, decahydro-1,4:5,8-dimethanonaphthalene-2,3,6,7-tetracarboxylic acid, decahydro-1,4-ethano-5,8-methano Naphthalene-2,3,6,7-tetracarboxylic acid, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetra Carboxylic acid (also known as "norbornane-2-spiro-2'-cyclopentanone-5'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid"), methylnorbornane- 2-spiro-α-cyclopentanone-α'-spiro-2''-(methylnorbornane)-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cyclohexanone- α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid (also known as "norbornane-2-spiro-2'-cyclohexanone-6'-spiro-2''-norbornane -5,5'',6,6''-tetracarboxylic acid''), methylnorbornane-2-spiro-α-cyclohexanone-α'-spiro-2''-(methylnorbornane)-5,5'', 6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cyclopropanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane -2-spiro-α-cyclobutanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cycloheptanone-α' -spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cyclooctanone-α'-spiro-2''-norbornane-5, 5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cyclononanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid , norbornane-2-spiro-α-cyclodecanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cycloundecanone- α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cyclododecanone-α'-spiro-2''-norbornane- 5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cyclotridecanone-α'-spiro-2''-norbornane-5,5'',6,6'' -tetracarboxylic acid, norbornane-2-spiro-α-cyclotetradecanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro -α-cyclopentadecanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-(methylcyclopentanone)- α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-(methylcyclohexanone)-α'-spiro-2''-norbornane Examples include tetracarboxylic acids such as -5,5'',6,6''-tetracarboxylic acid, and acid anhydrides thereof. Among these, dianhydrides having two acid anhydride structures are preferred, particularly 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2,3,4-cyclohexanetetracarboxylic dianhydride. Acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride is preferred, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride Acid dianhydride is more preferred, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride is even more preferred. Note that these may be used alone or in combination of two or more. When emphasis is placed on transparency, the amount of copolymerized alicyclic tetracarboxylic acids is, for example, preferably 50% by mass or more of the total tetracarboxylic acids, more preferably 60% by mass or more, and even more preferably 70% by mass. % or more, still more preferably 80% by mass or more, particularly preferably 90% by mass or more, and may even be 100% by mass.

Examples of tricarboxylic acids include aromatic tricarboxylic acids such as trimellitic acid, 1,2,5-naphthalene tricarboxylic acid, diphenyl ether-3,3',4'-tricarboxylic acid, and diphenylsulfone-3,3',4'-tricarboxylic acid. acids, or hydrogenated products of the above aromatic tricarboxylic acids such as hexahydrotrimellitic acid, alkylenes such as ethylene glycol bis trimellitate, propylene glycol bis trimellitate, 1,4-butanediol bis trimellitate, and polyethylene glycol bis trimellitate. Examples include glycol bistrimelitate, and monoanhydrides and esterified products thereof. Among these, monoanhydrides having one acid anhydride structure are preferred, and trimellitic anhydride and hexahydrotrimellitic anhydride are particularly preferred. Incidentally, these may be used alone or in combination.

Examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, 4,4'-oxydibenzenecarboxylic acid, or the above-mentioned aromatic dicarboxylic acids such as 1,6-cyclohexanedicarboxylic acid. Hydrogenates of oxalic acid, succinic acid, glutaric acid, adipic acid, heptanedioic acid, octanedioic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, 2-methylsuccinic acid, and acid chlorides thereof Alternatively, examples include esterified products. Among these, aromatic dicarboxylic acids and hydrogenated products thereof are preferred, with terephthalic acid, 1,6-cyclohexanedicarboxylic acid, and 4,4'-oxydibenzenecarboxylic acid being particularly preferred. Note that dicarboxylic acids may be used alone or in combination.

Diamines or isocyanates for obtaining colorless and highly transparent polyimides are not particularly limited, and include aromatic diamines, aliphatic diamines, and alicyclic diamines commonly used in polyimide synthesis, polyamide-imide synthesis, and polyamide synthesis. diisocyanates, aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, etc. can be used. From the viewpoint of heat resistance, aromatic diamines are preferred, and from the viewpoint of transparency, alicyclic diamines are preferred. Further, when aromatic diamines having a benzoxazole structure are used, it becomes possible to exhibit high elastic modulus, low thermal shrinkage, and low coefficient of linear expansion as well as high heat resistance. Diamines and isocyanates may be used alone or in combination of two or more.

Examples of aromatic diamines include 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,4-bis[2-(4-aminophenyl)-2-propyl]benzene, 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-hexafluoro Propane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 4-amino-N-(4-aminophenyl)benzamide, 3,3'-diaminodiphenyl ether , 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2'-trifluoromethyl-4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl Sulfide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfoxide, 3,4'-diaminodiphenylsulfoxide, 4,4'-diaminodiphenylsulfoxide, 3,3'-diaminodiphenylsulfone, 3,4 '-Diamino diphenyl sulfone, 4,4'-diaminodiphenylsulfone, 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-aminophenoxy)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-aminophenoxy)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-dimethylbenzyl)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-biphenoxy Benzophenone, 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-biphenoxybenzoyl)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-dimethyl) benzyl)phenoxy]benzonitrile, 4,4'-[9H-fluorene-9,9-diyl]bisaniline (also known as "9,9-bis(4-aminophenyl)fluorene"), spiro(xanthene-9,9' -fluorene)-2,6-diylbis(oxycarbonyl)]bisaniline, 4,4'-[spiro(xanthene-9,9'-fluorene)-2,6-diylbis(oxycarbonyl)]bisaniline, 4,4' -[spiro(xanthene-9,9'-fluorene)-3,6-diylbis(oxycarbonyl)]bisaniline and the like. Further, some or all of the hydrogen atoms on the aromatic ring of the aromatic diamine may be substituted with a halogen atom, an alkyl group or alkoxyl group having 1 to 3 carbon atoms, or a cyano group, and further, Part or all of the hydrogen atoms of the alkyl group or alkoxyl group of ~3 may be substituted with a halogen atom. Further, the aromatic diamines having the benzoxazole structure are not particularly limited, and examples thereof include 5-amino-2-(p-aminophenyl)benzoxazole, 6-amino-2-(p-aminophenyl)benzoxazole, Oxazole, 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'-diamino) diphenyl)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. Among these, in particular, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 4-amino-N-(4-aminophenyl)benzamide, 4,4'-diaminodiphenylsulfone, 3,3 '-Diaminobenzophenone is preferred. Incidentally, the aromatic diamines may be used alone or in combination.

Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,4-diamino-2-methylcyclohexane, 1,4-diamino-2-ethylcyclohexane, 1,4-diamino-2-n-propyl Cyclohexane, 1,4-diamino-2-isopropylcyclohexane, 1,4-diamino-2-n-butylcyclohexane, 1,4-diamino-2-isobutylcyclohexane, 1,4-diamino-2-sec-butylcyclohexane, Examples include 1,4-diamino-2-tert-butylcyclohexane and 4,4'-methylenebis(2,6-dimethylcyclohexylamine). Among these, 1,4-diaminocyclohexane and 1,4-diamino-2-methylcyclohexane are particularly preferred, and 1,4-diaminocyclohexane is more preferred. Incidentally, the alicyclic diamines may be used alone or in combination.

Examples of diisocyanates include diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5,2'- or 5,3' - or 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5,2 '-or 5,3'-or 6,2'-or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate, 3,2'-or 3,3'-or 4,2'-or 4, 3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-3, 3'-diisocyanate, diphenylmethane-3,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate, benzophenone-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, tolylene-2,4-diisocyanate, Tolylene-2,6-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, naphthalene-2,6-diisocyanate, 4,4'-(2,2bis(4-phenoxyphenyl)propane) diisocyanate, 3, 3'- or 2,2'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'- or 2,2'-diethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4, Aromatic diisocyanates such as 4'-diisocyanate, 3,3'-diethoxybiphenyl-4,4'-diisocyanate, and diisocyanates obtained by hydrogenating any of these (e.g., isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate) and the like. Among these, diphenylmethane-4,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, 3,3'- Dimethylbiphenyl-4,4'-diisocyanate, naphthalene-2,6-diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and 1,4-cyclohexane diisocyanate are preferred. Note that the diisocyanates may be used alone or in combination.

In this embodiment, the polymer film is preferably a polyimide film. When the polymer film is a polyimide film, it has excellent heat resistance.

The thickness of the polymer film is preferably 3 μm or more, more preferably 7 μm or more, still more preferably 14 μm or more, and even more preferably 20 μm or more. The upper limit of the thickness of the polymer film is not particularly limited, but in order to use it as a flexible electronic device, it is preferably 250 μm or less, more preferably 100 μm or less, and still more preferably 50 μm or less.

The average coefficient of linear expansion (CTE) between 30°C and 250°C of the polymer film is preferably 50 ppm/K or less. It is more preferably 45 ppm/K or less, still more preferably 40 ppm/K or less, even more preferably 30 ppm/K or less, particularly preferably 20 ppm/K or less. Further, it is preferably -5 ppm/K or more, more preferably -3 ppm/K or more, and even more preferably 1 ppm/K or more. When the CTE is within the above range, the difference in linear expansion coefficient with a general support (inorganic substrate) can be kept small, and the polymer film and inorganic substrate will not peel off even when subjected to a process of applying heat, or Warping of the entire support can be avoided. Here, CTE is a factor representing reversible expansion and contraction with respect to temperature. Note that the CTE of the polymer film refers to the average value of the CTE in the coating direction (MD direction) and the CTE in the width direction (TD direction) of polyamic acid.

When the polymer film is a transparent polyimide film, its yellowness index (hereinafter also referred to as "yellow index" or "YI") is preferably 10 or less, more preferably 7 or less, and even more preferably 5. or less, and even more preferably 3 or less. The lower limit of the yellowness index of the transparent polyimide is not particularly limited, but in order to use it as a flexible electronic device, it is preferably 0.1 or more, more preferably 0.2 or more, and still more preferably 0.3 or more. It is.

When the polymer film is a transparent polyimide film, the haze is preferably 1.0 or less, more preferably 0.8 or less, still more preferably 0.5 or less, even more preferably 0.3 or less. . The lower limit is not particularly limited, but industrially, there is no problem if it is 0.01 or more, and it may be 0.05 or more.

The heat shrinkage rate of the polymer film between 30° C. and 500° C. is preferably ±0.9% or less, more preferably ±0.6% or less. Thermal contraction rate 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 80 MPa or more, and still more preferably 100 MPa or more. The upper limit of the tensile strength at break is not particularly limited, but is practically less than about 1000 MPa. When the tensile strength at break is 60 MPa or more, it is possible to prevent the polymer film from breaking when peeled from the inorganic substrate. Note that 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 tensile elongation at break of the polymer film is preferably 1% or more, more preferably 5% or more, and still more preferably 10% or more. When the tensile elongation at break is 1% or more, handling properties are excellent. Note that the tensile elongation at break of the polymer film refers to the average value of the tensile elongation at break in the machine direction (MD direction) and the tensile elongation at break in the width direction (TD direction) of the polymer film.

The tensile modulus of the polymer film is preferably 2.5 GPa or more, more preferably 3 GPa or more, and still more preferably 4 GPa or more. When the tensile modulus is 2.5 GPa or more, the polymer film undergoes little elongation deformation when peeled from the inorganic substrate, resulting in excellent handling properties. The tensile modulus is preferably 20 GPa or less, more preferably 15 GPa or less, still more preferably 12 GPa or less. When the tensile modulus is 20 GPa or less, the polymer film can be used as a flexible film. Note that the tensile modulus of the polymer film refers to the average value of the tensile modulus in the machine direction (MD direction) and the tensile modulus 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, particularly preferably 4% or less. If the thickness unevenness exceeds 20%, it tends to be difficult to apply to narrow areas. Incidentally, the uneven thickness of the film can be determined based on the following formula by measuring the film thickness by randomly extracting about 10 positions from the film to be measured using, for example, a contact-type film thickness meter.
Film thickness unevenness (%)
= 100 x (maximum film thickness - minimum film thickness) ÷ average film thickness

The polymer film is preferably obtained in the form of a long polymer film with a width of 300 mm or more and a length of 10 m or more at the time of manufacture. More preferably, it is in the form of a molecular film. When the polymer film is wound into a roll, it becomes easy to transport the heat-resistant polymer film in the form of a roll. Furthermore, it is also possible to produce a laminate using a roll-to-roll process.

In the polymer film, in order to ensure handling properties and productivity, about 0.01 to 3% by mass of lubricant (particles) with a particle size of about 10 to 1000 nm is added and contained in the polymer film. Therefore, it is preferable to provide fine irregularities on the surface of the polymer film to ensure slipperiness.

<Inorganic substrate>
As the inorganic substrate, a glass plate, a semiconductor wafer, a metal plate, a ceramic plate, etc. can be used. 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 (alkali-free), Includes borosilicate glass (microsheet), aluminosilicate glass, etc. Among these, those with a linear expansion coefficient of 5 ppm/K or less are desirable, and commercially available products include "Corning (registered trademark) 7059" and "Corning (registered trademark) 1737" manufactured by Corning Corporation, which are liquid crystal glasses. "EAGLE", "AN100" manufactured by Asahi Glass, "OA10" and "OA11" manufactured by Nippon Electric Glass, "AF32" manufactured by SCHOTT, etc. are preferable. Examples of the semiconductor wafer include silicon wafer, germanium, silicon-germanium, gallium-arsenide, aluminum-gallium-indium, nitrogen-phosphorus-arsenic-antimony, SiC, InP (indium phosphide), InGaAs, GaInNAs, LT, LN, and ZnO. (zinc oxide), CdTe (cadmium tellurium), ZnSe (zinc selenide), and the like. The metal plate may be a single element metal such as W, Mo, Pt, Fe, Ni, or Au, or an alloy such as Inconel, Monel, Nimonic, carbon copper, Fe-Ni based Invar alloy, Super Invar alloy, or various stainless steels. included. Furthermore, nonwoven fabrics made of these metals may also be used. When using a metal plate in the present invention, it is preferable to use various types of stainless steel. Furthermore, multilayer metal plates formed by adding other metal layers and ceramic layers to these metals are also included. As the ceramic plate, a single or composite sintered body of alumina, magnesia, calcia, silicon nitride, boron nitride, aluminum nitride, beryllium oxide, etc. can be used. When a ceramic substrate is used in the present invention, it is preferable to use a ceramic substrate whose surface is smoothed by glass glazing treatment. These inorganic substrates may also be rolled up as long products with a width of 300 mm or more and a length of 10 m or more. Wrapping in a roll not only facilitates transportation, but also allows for the production of laminates using a roll-to-roll process.

The thickness of the inorganic substrate is not particularly limited, but from the viewpoint of handleability, the thickness is preferably 10 mm or less, more preferably 3 mm, and even more preferably 1.3 mm or less. The lower limit of the thickness is not particularly limited, but is preferably 0.005 mm or more, more preferably 0.01 mm or more, and still more preferably 0.02 mm or more.

The laminate of this embodiment preferably has a 90° peel strength (adhesive strength) of 0.2 N/cm or more, more preferably 0.5 N/cm or more, even more preferably It is 1.0 N/cm or more.
If the 90° peel strength after heating is 0.2 N/cm or more, it will not be possible to unintended results when a device is formed on the first substrate (for example, a polymer film) or when each substrate is processed by etching or the like. It is possible to prevent the second substrate (for example, an inorganic substrate) from peeling off.
Further, the 90° peel strength of the laminate after heating at 200° C. for 1 hour is preferably 10 N/cm or less, more preferably 8 N/cm or less, and still more preferably 6 N/cm or less.
If the 90° peel strength after heating is 10 N/cm or less, when you want to peel off the second substrate (for example, an inorganic substrate) after forming a device on the first substrate (for example, a polymer film), It becomes possible to peel off easily.

The laminate of this embodiment preferably has a 90° peel strength (adhesive strength) of 0.1 N/cm or more before heating, more preferably 0.2 N/cm or more, and still more preferably 0.3 N/cm. That's all.
When the 90° peel strength before heating is 0.1 N/cm or more, it is possible to prevent the first substrate and the second substrate from peeling off.
Further, the 90° peel strength of the laminate before heating is preferably 6 N/cm or less, more preferably 4 N/cm or less, and even more preferably 2 N/cm or less.
When the 90° peel strength before heating is 6 N/cm or less, it becomes possible to easily peel off when desired to peel off after heating.

The 90° peel strength before heating is the value of the laminate after bonding the first substrate and the second substrate together and then heat-treating them at 110°C for 60 minutes in the air (initial peel strength). Strength).
In addition, the 90° peel strength after heating is the value of the laminate after further heat treating the laminate at 200°C for 1 hour when measuring the 90° peel strength before heating (peel strength after 200°C heat treatment). ).

The method for manufacturing a laminate according to this embodiment includes:
Step A of preparing a first substrate and a second substrate;
Step B of preparing a mixed solution containing a silane coupling agent and water and having an alcohol content of 1 mol% or less relative to the silane coupling agent;
Step C of supplying the mixed solution onto the first substrate and/or the second substrate, and
The method includes a step D of bonding the first substrate and the second substrate together after the mixed solution is supplied.

In the method for manufacturing the laminate, first, a first substrate and a second substrate are prepared (step A). Since the first substrate and the second substrate have already been explained in the section regarding the laminate, their explanation will be omitted here.

Further, a mixed solution containing a silane coupling agent and water and having an alcohol content of 1 mol % or less relative to the silane coupling agent is prepared (Step B).
The alcohol content in the silane coupling agent solution can be measured by ¹ H-NMR. The ratio of the integral value of the peak derived from the alkyl chain in the silane coupling agent and the peak derived from alcohol was determined, and the ratio was determined as the alcohol content (mol %) with respect to the silane coupling agent.

In step B, first, a silane coupling agent and water are mixed and stirred until the hydrolysis reaction is completed. Usually, the stirring time is within the range of 1 hour or more and 5 hours or less at room temperature. The concentration of the silane coupling agent in the mixed solution is preferably 17 wt% or more and 80 wt% or less. By preparing a mixed solution at the above mixing ratio, the reaction of the silane coupling agent can proceed effectively.
After stirring, alcohol is removed from the liquid containing the silane coupling agent, water, and alcohol. An example of a method for removing alcohol from a liquid containing a silane coupling agent, water, and alcohol is fractional distillation. Specifically, alcohol can be removed from a liquid containing a silane coupling agent, water, and alcohol using an evaporator or the like.
As described above, it is possible to prepare a mixed solution that contains a silane coupling agent and water and has an alcohol content of 1 mol % or less based on the silane coupling agent.

However, Step B in the present invention is not limited to the above example. In step B, the mixed solution containing the silane coupling agent and water may be a mixed solution from which alcohol has been removed in advance.

The silane coupling agent in the mixed solution is: ²⁹ The total ratio of Si having the following T2 structure and the following T3 structure calculated from the integral value of the spectrum obtained by Si-NMR measurement is X, the following T0 structure, and the following T1 When Y is the total ratio of Si having the following T2 structure and the following T3 structure, it is preferable that X/Y is 81 or more.
However, in the following T0 structure, the following T1 structure, the following T2 structure, and the following T3 structure, Z is a divalent alkyl chain represented by C _n H _2n , and W is a monovalent alkyl chain represented by C _m H _2m+1 . It is an alkyl group or a hydrogen atom (where n is an integer of 1 or more and 10 or less, and m is an integer of 1 or more and 10 or less).

The n is preferably 1 or more, more preferably 2 or more. The n is preferably 6 or less, more preferably 4 or less.
The m is preferably 1 or more, more preferably 2 or more. The m is preferably 6 or less, more preferably 4 or less.

The X/Y is more preferably 82 or more, and still more preferably 85 or more. The above X/Y is preferably as large as possible, and is, for example, 99 or less.
The above-mentioned X/Y is a value determined by the method described in Examples.

Next, the mixed solution is supplied onto the first substrate and/or the second substrate (step C). As a method of supplying the mixed solution onto the first substrate and the second substrate, conventionally known methods such as dropping or various solution coating methods using a bar coater or the like can be adopted. can.

Next, the first substrate and the second substrate to which the mixed solution has been supplied are bonded together (Step D). Step D is performed after step C while the mixed solution is in a liquid state.

As a bonding method, a press method, a roll laminator method, etc. can be applied. For example, pressure can be applied in a planar or linear manner by pressing, laminating, or roll laminating under atmospheric pressure. The process can also be accelerated by heating during pressurization. In this embodiment, pressing or roll lamination in an atmospheric atmosphere is preferred, and a method using rolls (roll lamination, etc.) is particularly preferred because it allows lamination while sequentially extruding excess mixed solution at the adhesive interface from the adhesive surface.

The pressure during bonding is preferably 0.2 kgf/cm or more in linear pressure, and more preferably 0.4 kgf/cm or more. By bonding with a linear pressure of 0.2 kgf/cm or more, the substrates can be brought into good contact with each other.
Furthermore, the pressure during bonding is preferably 2.0 kgf/cm or less in linear pressure, and more preferably 1.8 kgf/cm or less. By bonding at a linear pressure of 2.0 kgf/cm or less, the amount of silane coupling agent solution between the substrates becomes appropriate, and good adhesive strength can be obtained.

Thereafter, heat treatment is performed to advance the reaction of the silane coupling agent and bond the first substrate and the second substrate.
The heat treatment may be set as appropriate within a range that allows the first substrate and the second substrate to be properly bonded. The heat treatment is not particularly limited, but may be divided into two stages: aging treatment and reaction treatment.
Examples of the aging treatment include treatment at a temperature of 25° C. or more and 65° C. or less for 1 hour or more and 48 hours or less.
Examples of the reaction treatment include treatment at a temperature of 80° C. or more and 110° C. or less for 1 hour or more and 48 hours or less.

Through the above steps, a laminate in which the first substrate, the silane coupling agent layer, and the second substrate are laminated in this order is obtained.
According to the method for manufacturing the laminate, since the alcohol content in the mixed solution is 1 mol % or less with respect to the silane coupling agent, the first substrate after being supplied with the mixed solution When the second substrate is bonded together, the amount of alcohol trapped in the laminate is small. As a result, the amount of floating can be reduced. As a result, the adhesive strength of the obtained laminate does not decrease significantly even after heating.

The method for manufacturing a laminate according to this embodiment has been described above.

In the embodiment described above, a laminate in which the first substrate, the silane coupling agent layer, and the second substrate are laminated in this order has been described. The laminate may further include a second silane coupling agent layer and a third substrate. Specifically, the laminate includes a first substrate, a first silane coupling agent layer, a second substrate, a second silane coupling agent layer, and a third substrate in this order. It may be a laminated body.
The first silane coupling agent layer and the second silane coupling agent layer may have the same structure as the "silane coupling agent layer" described above. The composition of the first silane coupling agent layer and the composition of the second silane coupling agent layer may be the same or different. Examples of the third substrate include the above-mentioned heat-resistant polymer film and the above-mentioned inorganic substrate.

The laminate is a laminate in which a first substrate, a first silane coupling agent layer, a second substrate, a second silane coupling agent layer, and a third substrate are laminated in this order. , the float between the first substrate and the second substrate is [B1]≧[A1], [B2]≧[A2], the number of B1 is 20 or less, and the number of B2 is 4 It is preferable to satisfy .0 mm or less.

Further, the laminate may include a first substrate, a first silane coupling agent layer, a second substrate, a second silane coupling agent layer, and a third substrate laminated in this order. In the case of a laminate, the float between the first substrate and the second substrate is such that "[B1]/[A1] is 1.5 or less" and "[B2]/[A2] is 2". .0 or less", and the float between the second and third substrates satisfies "[B1]/[A1] is 1.5 or less", and "[B2]/[A2] ] is preferably 2.0 or less.

The laminate is a laminate in which a first substrate, a first silane coupling agent layer, a second substrate, a second silane coupling agent layer, and a third substrate are laminated in this order. In this case, the manufacturing method is not particularly limited. For example, a laminate in which a first substrate, a first silane coupling agent layer, and a second substrate are stacked is prepared, and a third substrate is placed on the second substrate and/or a separately prepared third substrate. A mixed solution containing a silane coupling agent and water may be supplied onto the substrate, and the second substrate and the third substrate may be bonded together after the mixed solution has been supplied.

Hereinafter, the present invention will be explained in detail using Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

(Example 1)
<Preparation of silane coupling agent solution>
6 parts by mass of pure water was added to 20 parts by mass of a silane coupling agent (3-aminopropyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd.: KBM-903), and the mixture was stirred at room temperature (25°C) for 3 hours. Thereafter, using an evaporator equipped with a 30° C. water bath, the alcohol generated from the stirred liquid was removed over a period of 1 hour to obtain a silane coupling agent solution 1 (mixed solution).

<Preparation of laminate>
A sufficient amount of silane coupling agent solution 1 was dropped onto a SUS substrate (material: SUS304, thickness 30 μm, 520 mm x 520 mm, surface arithmetic mean roughness (Ra): 120 nm). Next, a polyimide film (manufactured by XENOMAX Japan Co., Ltd., product name: XENOMAX, thickness 15 μm, 500 mm x500mm) were laminated. Due to this lamination, excess silane coupling agent solution 1 was extruded. The obtained laminate was aged in air at 40° C. for 12 hours, and then heat treated in air at 110° C. for 60 minutes to obtain a laminate according to Example 1.
Note that the SUS substrate corresponds to the second substrate of the present invention, and the polyimide film corresponds to the first substrate of the present invention.
The arithmetic mean roughness (Ra) of the surface was measured using a laser microscope manufactured by Keyence Corporation (product name: OPTELICS HYBRID). The measurements were conducted under the following conditions. The surface roughness of the substrate was measured using the center of the substrate as an observation area and the center of the observation area as an evaluation area. Evaluation was performed in one observation area for each sample. The same measurements were made for the substrates of the following examples (excluding glass substrates).
Observation area: 300μm x 300μm
Evaluation area: 150μm x 150μm
Observation magnification: 50x

(Example 2)
<Preparation of silane coupling agent solution>
Silane coupling agent solution 2 was obtained in the same manner as in Example 1 except that 20 parts by mass of pure water was added instead of 6 parts by mass of pure water.
<Preparation of laminate>
A laminate according to Example 2 was obtained in the same manner as Example 1 except that silane coupling agent solution 2 was used.

(Example 3)
<Preparation of silane coupling agent solution>
Silane coupling agent solution 3 was obtained in the same manner as in Example 1 except that 46 parts by mass of pure water was added instead of 6 parts by mass of pure water.
<Preparation of laminate>
A laminate according to Example 3 was obtained in the same manner as Example 1 except that silane coupling agent solution 3 was used.

(Example 4)
<Preparation of silane coupling agent solution>
Example 3 except that 3-aminopropyltriethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.: KBE-903 (molecular formula: (C ₂ H ₅ O) ₃ SiC ₃ H ₆ NH ₂ )) was used as the silane coupling agent. In the same manner, silane coupling agent solution 4 was obtained. The reason why the molar ratio of [alcohol]/[silane coupling agent] is different between Example 3 and Example 4 is because the molecular weight of the silane coupling agent is different.
<Preparation of laminate>
A laminate according to Example 4 was obtained in the same manner as in Example 1 except that silane coupling agent solution 4 was used.

(Example 5)
<Preparation of laminate>
Instead of the SUS substrate, use a copper substrate (electrolytic copper foil GTS-SD manufactured by Furukawa Electric Co., Ltd., thickness 105 μm, 520 mm x 520 mm, surface arithmetic mean roughness (Ra): 400 nm)
A laminate according to Example 5 was obtained in the same manner as Example 3 except that the following was used.

(Example 6)
<Preparation of silane coupling agent solution>
Silane coupling agent solution 5 was obtained in the same manner as in Example 1 except that 60 parts by mass of pure water was added instead of 6 parts by mass of pure water.
<Preparation of laminate>
Instead of the SUS substrate, a glass substrate (thickness 0.7 mm, 520 mm x 520 mm, surface arithmetic mean roughness (Ra): 0.2 nm): Nippon Electric Glass Co., Ltd. OA10G) was used, and a silane cup was used. A laminate according to Example 6 was obtained in the same manner as in Example 3 except that silane coupling agent solution 5 was used instead of ring agent solution 3.
The arithmetic mean roughness (Ra) of the glass surface was measured using a scanning probe microscope with a surface property evaluation function ("SPA300/nanonavi" manufactured by SII Nano Technology Co., Ltd.). The measurement was performed in DFM mode, the cantilever used was "DF3" or "DF20" made by SII Nanotechnology Co., Ltd., and the scanner was "FS-20A" made by SII Nanotechnology Co., Ltd., and the scanning range was The size was 10 μm square, and the measurement resolution was 512×512 pixels. After performing secondary tilt correction on the measurement image using the software included with the device, if noise associated with the measurement is included, use other flattening processing (for example, flat processing) as appropriate, and use the software included with the device to correct the Ra The value was calculated. Measurements were taken at three arbitrary locations to determine the Ra value, and the average value thereof was employed.

(Example 7)
<Preparation of laminate>
Example 6 was carried out in the same manner as in Example 6, except that a SUS nonwoven fabric (thickness 35 μm, 520 mm x 520 mm, fiber diameter 5 μm, basis weight 5.1 g/cm ² ) was used as the second substrate instead of the SUS substrate. A laminate according to No. 7 was obtained.

(Comparative example 1)
<Preparation of silane coupling agent solution>
Silane coupling agent solution 6 was obtained in the same manner as in Example 1 except that 100 parts by mass of pure water was added instead of 6 parts by mass of pure water.
<Preparation of laminate>
A laminate according to Comparative Example 1 was obtained in the same manner as in Example 1 except that silane coupling agent solution 6 was used.

(Comparative example 2)
<Preparation of silane coupling agent solution>
46 parts by mass of pure water was added to 20 parts by mass of a silane coupling agent (3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.: KBM-903), and the mixture was stirred at room temperature (25°C) for 3 hours. Solution 7 (mixed solution) was obtained.
<Preparation of laminate>
A laminate according to Comparative Example 2 was obtained in the same manner as in Example 1 except that silane coupling agent solution 7 was used.

(Comparative example 3)
<Preparation of laminate>
A laminate according to Comparative Example 3 was obtained in the same manner as in Example 7 except that silane coupling agent solution 6 was used.

<Measurement of alcohol content in silane coupling agent solution>
The alcohol/silane coupling agent ratio in the silane coupling agent solution was measured by ¹ H-NMR.
20% by mass of heavy water was added to the silane coupling agent solution. ¹ H-NMR measurements were performed immediately after dilution with heavy water.
The alcohol content relative to the silane coupling agent is determined by the ratio of the integral value of the peak around 2.6 ppm of CH ₂ derived from the silane coupling agent and the peak around 3.2 to 3.5 ppm of CH ₃ derived from methanol. The amount (mol%) was determined.
Specifically, it was calculated using the following formula.
Alcohol content (mol%) with respect to silane coupling agent = [(integral value of CH ₃ peak derived from methanol/3)]/[(integral value of CH ₂ peak in silane coupling agent)/2) ]
The alcohol content of the silane coupling agent solution of Example 1 with respect to the silane coupling agent was 0.9 mol %.
Furthermore, in Example 4, the ratio was determined using the peak around 1.2 ppm of CH ₃ derived from ethanol.
The results are shown in Table 1.
(Measurement condition)
Equipment: Fourier transform nuclear magnetic resonance apparatus (Bruker Japan Co., Ltd. AVANCE NEO 600 model)
Measurement solution: mix sample solution and heavy water at 80/20 vol ratio
^1H resonance frequency: 600.134MHz
Detection pulse flip angle: 30°
Data acquisition time: 3-4 seconds Delay time: 1 second Number of integration: 10-40 times Measurement temperature: 30℃

< ²⁹ Si-NMR measurement of silane coupling agent solution>
20% by mass of heavy water was added to the silane coupling agent solution. ²⁹ Si-NMR measurements were performed immediately after dilution with heavy water.
The content (%) of Si having a T0 structure, Si having a T1 structure, Si having a T2 structure, and Si having a T3 structure was calculated from the ratio of the integral values of the obtained spectra. The results are shown in Table 1. Table 1 also shows the total content (%) of T0 and T1 and the total content (%) of T2 and T3. Note that the total content (%) of T2 and T3 corresponds to the above-mentioned X/Y.
(Measurement condition)
Equipment: Fourier transform nuclear magnetic resonance apparatus (Bruker Japan Co., Ltd. AVANCE NEO 600 type)
Measurement solution: mix sample solution and heavy water at 80/20 vol ratio
²⁹ Si resonance frequency: 119.22MHz
Detection pulse flip angle: 90°
Data acquisition time: 2 seconds Delay time: 13 seconds Proton decoupling: Inverse gate decoupling accumulation count: 30℃
Accumulation number: 100 to 500 times

<Measurement of floating before heating>
The laminates of Examples and Comparative Examples were cut out to a size of 2,500 cm ² (50 cm x 50 cm) centering on the center in the width direction. The number of floats (the number of bubbles) having a diameter of 0.5 mm or more was visually counted from the cut out laminate. The number was set as A1. Next, the diameters of the A1 floats were measured using a digital microscope (model name: VHX-970F, manufactured by Keyence Corporation), and the average diameter was defined as A2 mm.
When the size of the laminate was smaller than 2,500 cm ² , the entire surface of the laminate was measured, and after float counting, the number was recalculated to the equivalent of 2,500 cm ² .

<Measurement of floating after heating>
The laminate used for floating measurement before heating was heated in air at 200° C. for 1 hour. The number of floats (the number of bubbles) having a diameter of 0.5 mm or more was visually counted in the heated laminate, and the number was designated as B1. Next, the diameters of the B1 floats were measured using a digital microscope (model name: VHX-970F, manufactured by Keyence Corporation), and the average thereof was taken as B2 mm.
When the size of the laminate was smaller than 2,500 cm ² , the entire surface of the laminate was measured and the floats were counted, and then the number was recalculated based on 2,500 cm ² .

A1, A2, B1, and B2 are shown in Table 1.

<90 degree peel strength>
The laminates of Examples and Comparative Examples were heated at 200° C. for 1 hour. Thereafter, the 90 degree peel strength was measured according to the 90 degree peel method specified in JIS K6854-1:1999.
Equipment name: Autograph AG-IS manufactured by Shimadzu Corporation
Measurement temperature: room temperature Peeling speed: 100mm/min
Atmosphere: Air Measurement sample width: 10mm

Claims

A laminate in which a first substrate, a silane coupling agent layer, and a second substrate are laminated in this order,
When the number of circular floats with a diameter of 0.5 mm or more before heating per area of 2,500 cm 2 is A1, and the number of circular floats with a diameter of 0.5 mm or more after heating at 200 ° C for 1 hour is B1. , [B1]≧[A1],
When the average diameter of the A1 floats is A2, and the average diameter of the B1 floats is B2, [B2]≧[A2] is satisfied,
The number of B1 is 20 or less,
A laminate characterized in that the B2 is 4.0 mm or less.
the first substrate is a heat-resistant polymer film,
The laminate according to claim 1, wherein the second substrate is a metal substrate.
The laminate according to claim 1 or 2, wherein the silane coupling agent constituting the silane coupling agent layer has an amino group.
The laminate according to any one of claims 1 to 3, wherein the 90° initial peel strength between the first substrate and the second substrate is 0.1 N/cm or more and 6 N/cm or less. body.
Claims 1 to 4, wherein a 90° peel strength between the first substrate and the second substrate after heating at 200° C. for 1 hour is 0.2 N/cm or more and 10 N/cm or less. The laminate according to any one of the above.
Step A of preparing a first substrate and a second substrate;
Step B of preparing a mixed solution containing a silane coupling agent and water and having an alcohol content of 1 mol% or less relative to the silane coupling agent;
Step C of supplying the mixed solution onto the first substrate and/or the second substrate, and
A method for manufacturing a laminate, comprising a step D of bonding the first substrate and the second substrate together after the mixed solution is supplied.
7. The method for manufacturing a laminate according to claim 6, wherein the step B includes a step of removing alcohol from a liquid containing a silane coupling agent, water, and alcohol.
The silane coupling agent in the mixed solution is: 29 The total ratio of Si having the following T2 structure and the following T3 structure calculated from the integral value of the spectrum obtained by Si-NMR measurement is X, the following T0 structure, and the following T1 8. The method for manufacturing a laminate according to claim 6, wherein X/Y is 81 or more, where Y is the total ratio of Si having the following T2 structure and the following T3 structure.
However, in the following T0 structure, the following T1 structure, the following T2 structure, and the following T3 structure, Z is a divalent alkyl chain represented by C n H 2n , and W is a monovalent alkyl chain represented by C m H 2m+1 . It is an alkyl group or a hydrogen atom (where n is an integer of 1 or more and 10 or less, and m is an integer of 1 or more and 10 or less).