Laminate and method for producing laminate

Abstract

To provide a laminate having sufficient adhesive strength even after high-temperature heating.SOLUTION: There is provided a laminate in which a first substrate, a silane coupling agent layer, and a second substrate are laminated in this order. The first substrate is a polyimide film, and the second substrate is a metal substrate. The silane coupling agent constituting the silane coupling agent layer has an amino group. An initial 90° peeling strength between the first substrate and the second substrate after the first substrate and the second substrate are bonded together and then heat-treated at 110°C for 60 minutes in an air atmosphere is 0.1 N / cm or more and 6 N / cm or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a laminate and a method for manufacturing a laminate. [Background technology]

[0002] In recent years, there has been active development of technologies for forming functional elements such as semiconductor elements, MEMS elements, and display elements on polymer films, with the aim of making these elements lighter, smaller, thinner, and more flexible. Traditionally, ceramics have been used as the base material for electronic components in information and communications equipment (broadcasting equipment, mobile radio, portable communications equipment, etc.), radar, high-speed information processing devices, and other such equipment. These materials are heat-resistant and can handle the increasingly high signal frequencies (reaching the GHz range) of information and communications equipment. However, ceramics are not flexible and are difficult to make thin, limiting the fields in which they can be used. Therefore, polymer films have recently been used as substrates.

[0003] Known methods for manufacturing a laminate in which a functional element is formed on a polymer film include: (1) laminating a metal layer on a resin film via an adhesive or pressure-sensitive adhesive, (2) placing a metal layer on a resin film and then laminating by heating and pressurizing, (3) 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) placing a resin powder for forming a resin film on a metal layer and compression molding it, and (5) forming a conductive material on a resin film by screen printing or sputtering. In addition, when manufacturing a laminate with three or more layers, various combinations of the above methods are used.

[0004] On the other hand, during the process of forming the laminate, the laminate is often exposed to high temperatures. For example, in the fabrication of low-temperature polysilicon thin-film transistors, heating to approximately 450°C may be required for dehydrogenation, and in the fabrication of hydrogenated amorphous silicon thin films, temperatures of approximately 200 to 300°C may be applied to the film. Furthermore, when the laminate is used for heaters or power semiconductors, it is exposed to temperatures of approximately 150 to 500°C for long periods of time. Therefore, the polymer film constituting the laminate must be heat-resistant, but in reality, only limited polymer films can withstand such high temperatures. Furthermore, as mentioned above, adhesives or glues can be used to bond a polymer film to a metal layer, but the bonding surface between the polymer film and the metal layer (i.e., the adhesive or glue used for bonding) also requires heat resistance. However, conventional adhesives and glues used for bonding do not have sufficient heat resistance and can cause problems such as peeling of the polymer film (i.e., reduced peel strength), the generation of blisters, and the generation of carbides during the process or actual use, making them inapplicable. In particular, when the film is exposed to high temperatures for a long period of time or used at high temperatures for a long period of time, the peel strength is significantly reduced, making the film unusable as a product.

[0005] In view of these circumstances, a laminate of a polymer film and an inorganic substrate has been proposed for producing a so-called flexible electronic device, in which a functional element is formed on a flexible substrate. The laminate is formed by bonding a polyimide film, which has excellent heat resistance, is strong, and can be thinned, to an inorganic substrate via a silane coupling agent (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-2622 Summary of the Invention [Problem to be solved by the invention]

[0007] In the above-mentioned laminate, a layer containing a silane coupling agent (hereinafter also referred to as a silane coupling agent layer) is interposed between the inorganic substrate and the heat-resistant polymer film, thereby preventing the inorganic substrate from peeling off from the polyimide film before or during device formation, and enabling the inorganic substrate to be easily peeled off from the polyimide film after device formation.

[0008] However, even when a laminate having a silane coupling agent layer interposed between an inorganic substrate and a heat-resistant polymer film is used, there is a problem that the adhesive strength may be partially reduced when the laminate is prepared by applying an aqueous solution of the silane coupling agent, when heated at a high temperature. The present inventors have also found that the same problem occurs not only in laminates of inorganic substrates and heat-resistant polymer films, but also when two substrates are bonded together via a silane coupling agent layer.

[0009] 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. Also, an object of the present invention is to provide a method for producing the laminate. [Means for solving the problem]

[0010] In view of this situation, the present inventors have conducted extensive research and have found that, as long as the number of circular raised portions after heating does not increase significantly compared to before heating and the average diameter of the circular raised portions after heating does not increase significantly compared to before heating, the adhesive strength does not decrease significantly even after heating, and have completed the present invention.

[0011] 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, Area 2,500cm 2The number of circular floats with a diameter of 0.5 mm or more per unit area before heating is defined as A1, and the number of circular floats with a diameter of 0.5 mm or more per unit area after heating at 200°C for 1 hour is defined as B1. The condition [B1] ≥ [A1] is satisfied. 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 B1 is 20 or less, The B2 is 4.0 mm or less.

[0012] Since [B1]≧[A1] is satisfied and B1 is 20 or less, it can be said that the number of floats after heating does not increase significantly compared to before heating. Also, since [B2]≧[A2] is satisfied and B2 is 4.0 mm or less, it can be said that the diameter of the floats after heating does not increase significantly compared to before heating. In this way, with 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, so the adhesive area is secured even after heating, and therefore the adhesive strength does not decrease significantly even after heating.

[0013] In the above-mentioned configuration, the first substrate is a heat-resistant polymer film, The second substrate is preferably a metal substrate.

[0014] When the first substrate is a heat-resistant polymer film and the second substrate is a metal substrate, for example, it is possible to form an electronic device such as a functional element on the heat-resistant polymer film with the heat-resistant polymer film adhered to the metal substrate. Furthermore, by forming a circuit on the metal substrate itself by etching or the like, it can be used for heater applications such as flexible heaters. Furthermore, a laminate in which a heat-resistant polymer film and a metal substrate are bonded together can be used for power semiconductor applications.

[0015] In the above-described configuration, the silane coupling agent constituting the silane coupling agent layer preferably has an amino group.

[0016] When the silane coupling agent has an amino group, it bonds with the reactive groups on the first and second substrates when organic materials are used for the first and second substrates. As a result, the adhesive strength between the first and second substrates can be increased. In addition, the stability of the silane coupling agent when it is dissolved in water is improved.

[0017] Further, the method for producing a laminate according to the present invention comprises the steps of: A step A of preparing a first substrate and a second substrate; A 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; a 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 has been supplied.

[0018] According to the above configuration, the content of alcohol in the mixed solution is 1 mol % or less relative to the silane coupling agent. Therefore, when the first substrate and the second substrate are bonded together after the mixed solution is supplied, the amount of alcohol trapped within the laminate is small. As a result, the amount of lifting can be reduced. As a result, the adhesive strength of the resulting laminate does not decrease significantly even after heating. This point will be explained in detail below. The present inventors have found that the amount of floating can be suitably reduced by setting the content of alcohol in the mixed solution to 1 mol % or less relative to the silane coupling agent. Specifically, the present inventors have found the following. When the silane coupling agent is hydrolyzed, a silanol group is generated. The silanol group bonds with a reactive group (e.g., an OH group) on the first substrate and / or the second substrate. Here, when the silane coupling agent is hydrolyzed to generate a silanol group, an alcohol is generated as a by-product. In conventional laminate manufacturing, even after bonding the first substrate and the second substrate, hydrolysis of the silane coupling agent progresses to a certain extent, and the by-product alcohol is trapped within the laminate. The present inventors have discovered that this alcohol is the cause of the lifting. Furthermore, the inventors discovered that the amount of alcohol trapped within the laminate can be reduced by first hydrolyzing the silane coupling agent to a certain extent before bonding the first substrate and the second substrate together, and by removing the alcohol in advance from the liquid containing the silane coupling agent (the solution for forming the silane coupling agent layer). From the above, when the content of the alcohol in the mixed solution is 1 mol % or less relative to the silane coupling agent, the amount of floating can be suitably reduced. This is also clear from the results of the examples.

[0019] In the above-described configuration, the step B preferably includes a step of removing the alcohol from a liquid containing the silane coupling agent, water, and alcohol.

[0020] By carrying out the step of removing the alcohol from the liquid containing the silane coupling agent, water, and alcohol, it is possible to suitably obtain a mixed solution having an alcohol content of 1 mol % or less relative to the silane coupling agent.

[0021] In the above-described configuration, the silane coupling agent in the mixed solution is 29 When 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, and the total ratio of Si having the following T0 structure, the following T1 structure, the following T2 structure, and the following T3 structure is Y, it is preferable that X / Y is 81 or more. However, in the following T0 structure, T1 structure, T2 structure, and T3 structure, Z is C n H 2n is a divalent alkyl chain represented by m H 2m+1or 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).

[0022] [ka]

[0023] [ka]

[0024] [ka]

[0025] [ka]

[0026] When the X / Y ratio is 81 or more, the hydrolysis of the silane coupling agent progresses to a certain extent, resulting in an oligomer state and the generation of silanol groups. The silanol groups bond with reactive groups (e.g., OH groups) on the first substrate and / or the second substrate. As a result, the amount of lifting can be further reduced. [Effects of the Invention]

[0027] According to the present invention, it is possible to provide a laminate in which the adhesive strength does not decrease significantly in parts even after high-temperature heating, and also to provide a method for producing the laminate. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, an embodiment of the present invention will be described.

[0029] <Laminate> 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, Area 2,500cm 2 The number of circular floats with a diameter of 0.5 mm or more per unit area before heating is defined as A1, and the number of circular floats with a diameter of 0.5 mm or more per unit area after heating at 200°C for 1 hour is defined as B1. The condition [B1] ≥ [A1] is satisfied. 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 B1 is 20 or less, The B2 is 4.0 mm or less. In this specification, "area 2,500 cm 2 "Per square" means "per 50cm x 50cm square."

[0030] Since [B1]≧[A1] is satisfied and B1 is 20 or less, it can be said that the number of floats after heating does not increase significantly compared to before heating. Also, since [B2]≧[A2] is satisfied and B2 is 4.0 mm or less, it can be said that the diameter of the floats after heating does not increase significantly compared to before heating. In this way, with the laminate, the number of lifted portions after heating does not increase significantly compared to before heating, and the diameter of the lifted portions after heating does not increase significantly compared to before heating, so the adhesive area is secured even after heating, and therefore the adhesive strength does not decrease significantly even after heating.

[0031] [B1]≧[A1], [B2]≧[A2], B1 being 20 or less, and B2 being 4.0 mm or less can be achieved, for example, by appropriately adjusting the mixed solution used when forming the silane coupling agent layer, as described below.

[0032] The number [A1] is preferably 10 or less, more preferably 9 or less, and even more preferably 5 or less. The number [A1] is preferably small, but may be, for example, 0 or more, or 1 or more.

[0033] The number [B1] is preferably 15 or less, more preferably 7 or less. The number [B1] is preferably small, but may be, for example, 0 or more, or 1 or more.

[0034] The [A2] is preferably 2.0 mm or less, more preferably 1.0 mm or less. The smaller the [A2], the more preferable it is, for example, 0.5 mm or more.

[0035] The [B2] is preferably 4.0 mm or less, more preferably 2.0 mm or less. The smaller the [B2], the more preferable it is, for example, 0.5 mm or more.

[0036] In the laminate, it is preferable that [B1] / [A1] is 1.5 or less and [B2] / [A2] is 2.0 or less.

[0037] When the [B1] / [A1] ratio is 1.5 or less, it can be said that the number of floats after heating does not increase significantly compared to before heating, and when the [B2] / [A2] ratio is 2.0 or less, it can be said that the diameter of floats after heating does not increase significantly compared to before heating.

[0038] The ratios [B1] / [A1] and [B2] / [A2] can be achieved, for example, by appropriately adjusting the mixed solution used when forming the silane coupling agent layer, as will be described later.

[0039] The ratio [B1] / [A1] is preferably 1.5 or less, more preferably 1.2 or less. The ratio [B1] / [A1] is preferably small, but may be, for example, 1 or more.

[0040] The ratio [B2] / [A2] is preferably 1.8 or less, more preferably 1.5 or less. The ratio [B2] / [A2] is preferably small, but may be, for example, 1 or more.

[0041] The first substrate may be a heat-resistant polymer film or an inorganic substrate. The second substrate may be a heat-resistant polymer film or an inorganic substrate. The combination of the first substrate and the second substrate is not particularly limited.

[0042] The combination of the first substrate and the second substrate may be (a) both the first substrate and the second substrate may be inorganic substrates, (b) both the first substrate and the second substrate may be heat-resistant polymer films, or (c) one of the first substrate and the second substrate may be an inorganic substrate and the other may be a heat-resistant polymer film. A preferred combination of the first substrate and the second substrate is one in which 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, it is possible to form an electronic device such as a functional element on the heat-resistant polymer film with the heat-resistant polymer film adhered to the metal substrate. Furthermore, by forming a circuit on the metal substrate itself by etching or the like, it can be used for heater applications such as flexible heaters. Furthermore, a laminate in which a heat-resistant polymer film and a metal substrate are bonded together can be used for power semiconductor applications.

[0043] <Silane coupling agent layer> The silane coupling agent layer according to this embodiment is not particularly limited, but is a layer formed by supplying a mixed solution containing a silane coupling agent and water onto the first substrate and / or the second substrate, and it is preferable that the alcohol content in the mixed solution is 1 mol % or less relative to the silane coupling agent. When the silane coupling agent is hydrolyzed, a silanol group is generated. The silanol group bonds with a reactive group (e.g., an OH group) on the first substrate and / or the second substrate. Here, when the silane coupling agent is hydrolyzed to generate a silanol group, an alcohol is generated as a by-product. In the conventional laminate manufacturing method, even after bonding the first substrate and the second substrate, the hydrolysis of the silane coupling agent progresses to a certain extent, and the by-product alcohol is trapped within the laminate. The present inventors have found that this alcohol is the cause of the lifting. In this embodiment, before bonding the first substrate and the second substrate, the silane coupling agent is hydrolyzed to a certain extent to remove alcohol from the liquid containing the silane coupling agent (the solution for forming the silane coupling agent layer), thereby reducing the amount of alcohol trapped in the laminate. In another embodiment, the mixed solution may be one from which the alcohol has been removed in advance. When the content of the alcohol in the mixed solution is 1 mol % or less relative to the silane coupling agent, it is easy to achieve [B1]≧[A1], [B2]≧[A2], the number of B1 particles being 20 or less, and the number of B2 particles being 4.0 mm or less. Furthermore, when the content of alcohol in the mixed solution is 1 mol % or less relative to the silane coupling agent, it is easy to achieve "the ratio [B1] / [A1] is 1.5 or less" and "the ratio [B2] / [A2] is 2.0 or less." The content of the alcohol in the mixed solution is more preferably 0.8 mol % or less, and even more preferably 0.5 mol % or less. The lower the content of the alcohol in the mixed solution, the better, but it is, for example, 0.1 mol % or more, 0.2 mol % or more, etc.

[0044] The thickness of the silane coupling agent layer is preferably less than 1.0 μm. Furthermore, in processes where the minimum amount of silane coupling agent is desired, a thickness of 500 nm or less can also be used. From the viewpoint of adhesive strength, the thickness of the silane coupling agent layer is desirably 1 nm or more. The thickness of the silane coupling agent layer can be adjusted by the concentration of the mixed solution, the amount supplied onto the substrates (first substrate, second substrate), and the pressure applied when bonding the substrates (first substrate, second substrate).

[0045] The silane coupling agent contained in the mixed solution is not particularly limited, but it is preferable that the silane coupling agent is hydrolyzed to a certain extent and has a high 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, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, 2-(3,4- 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane Examples of suitable alkylsilanes include 3-methyl-3-methylpropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 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, and chloromethyltrimethoxysilane.Among these, preferred ones include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, aminophenyltrimethoxysilane, aminophenethyltrimethoxysilane, aminophenylaminomethylphenethyltrimethoxysilane, etc. When heat resistance is required in the process, those in which the Si and amino groups are linked by an aromatic group are desirable. When the silane coupling agent has an amino group, it bonds with the reactive groups on the first and second substrates when the first and second substrates are made of organic materials, thereby increasing the adhesive strength between the first and second substrates.

[0046] Other details of the mixed solution will be explained in the section on the method for producing the laminate.

[0047] <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, and even more preferably 145°C or higher. Examples of the polymer film include films of amorphous polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polyamideimide, polyetherimide, polybenzoxazole, polyimidebenzoxazole, polyethylene naphthalate, silicone resin, fluororesin, and liquid crystal polymer. As the polymer film, it is particularly preferable to use a polymer film having an imide bond. Examples of the polymer film having an imide bond include films of polyimide, polyamideimide, polyetherimide, polyimidebenzoxazole, and bismaleimide triazine.

[0048] A polyimide resin film (sometimes referred to as a polyimide film), which is an example of the polymer film, will be described in detail below. In general, a polyimide resin film is obtained by applying a polyamic acid (polyimide precursor) solution obtained by reacting diamines with tetracarboxylic acids in a solvent to a support for preparing the polyimide film, drying the solution to form a green film (hereinafter also referred to as a "polyamic acid film"), and further subjecting the green film to high-temperature heat treatment on the support for preparing the polyimide film or in a state where it has been peeled off from the support to cause a dehydration ring-closing reaction.

[0049] The polyamic acid (polyimide precursor) solution can be applied by any of the conventionally known solution application methods, such as spin coating, doctor blade, applicator, comma coater, screen printing, slit coating, reverse coating, dip coating, curtain coating, and slit die coating.

[0050] The diamines constituting the polyamic acid are not particularly limited, and aromatic diamines, aliphatic diamines, alicyclic diamines, etc., 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 achieve high heat resistance as well as high elastic modulus, low thermal shrinkage, and low linear expansion coefficient. The diamines may be used alone or in combination of two or more.

[0051] 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-(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'-diazomethane)-1,1-dimethyl-2,2-dibenzoxazole, 1-(5-aminobenzoxazolo)-4-(6-aminobenzoxazolo)benzene ... 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-(3,4'-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.

[0052] 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 aminodiphenyl 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'-diaminodi Phenylmethane, 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)phenyl]- bis(4-aminophenoxy)phenyl]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]diphenyl sulfone, 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,Examples of such aromatic diamines include 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 aromatic diamines in which some or all of the hydrogen atoms on the aromatic ring of the aromatic diamine have been substituted with halogen atoms, alkyl or alkoxy groups having 1 to 3 carbon atoms, cyano groups, or halogenated alkyl or alkoxy groups having 1 to 3 carbon atoms in which some or all of the hydrogen atoms of the alkyl or alkoxy groups have been substituted with halogen atoms.

[0053] Examples of the aliphatic diamines include 1,2-diaminoethane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, and 1,8-diaminoethane. 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 all diamines, more preferably 10% by mass or less, and even more preferably 5% by mass or less. In other words, aromatic diamines preferably account for 80% by mass or more of all diamines, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0054] As the tetracarboxylic acids constituting the polyamic acid, aromatic tetracarboxylic acids (including their acid anhydrides), aliphatic tetracarboxylic acids (including their acid anhydrides), and alicyclic tetracarboxylic acids (including their acid anhydrides) commonly used in polyimide synthesis can be used. When these are acid anhydrides, the molecule may contain one or two anhydride structures, but preferably contains two anhydride structures (dianhydrides). The tetracarboxylic acids may be used alone or in combination of two or more.

[0055] The aromatic tetracarboxylic acid is not particularly limited, but is preferably a pyromellitic acid residue (i.e., one having a structure derived from pyromellitic acid), and 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, and 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propanoic anhydride. When heat resistance is important, the aromatic tetracarboxylic acids preferably account for, for example, 80 mass % or more of all tetracarboxylic acids, more preferably 90 mass % or more, and even more preferably 95 mass % or more.

[0056] Examples of alicyclic tetracarboxylic acids include alicyclic tetracarboxylic acids such as cyclobutane tetracarboxylic acid, 1,2,4,5-cyclohexane tetracarboxylic acid, and 3,3',4,4'-bicyclohexyl tetracarboxylic acid, as well as their acid anhydrides. Among these, dianhydrides having two anhydride structures (e.g., cyclobutane tetracarboxylic dianhydride, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, and 3,3',4,4'-bicyclohexyl tetracarboxylic dianhydride) are preferred. 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 mass % or more of the total tetracarboxylic acids, more preferably 90 mass % or more, and even more preferably 95 mass % or more.

[0057] The polyimide film may be a transparent polyimide film.

[0058] A colorless and transparent polyimide, an example of the polymer film, will now be described. Hereinafter, to avoid complication, it will also be referred to simply as transparent polyimide. The transparency of the transparent polyimide is preferably such that the total light transmittance is 75% or more. It is more preferably 80% or more, even more preferably 85% or more, even more preferably 87% or more, and particularly preferably 88% or more. There is no particular upper limit for the total light transmittance of the transparent polyimide, but for use in flexible electronic devices, it is preferably 98% or less, more preferably 97% or less. The colorless and transparent polyimide of the present invention is preferably a polyimide with a total light transmittance of 75% or more.

[0059] Aromatic tetracarboxylic acids for obtaining colorless and highly transparent polyimides include 4,4'-(2,2-hexafluoroisopropylidene)diphthalic acid, 4,4'-oxydiphthalic acid, 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)]dibenzyl, and 4,4'-[4,4'-(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(benzene-1,4-diyloxy)]dibenzyl. Benzene-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 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-dicarboxylic acid, 4,4'-[4,4'-(3H-2,

[0039] Examples of tetracarboxylic acids include 1-benzoxathiol-1,1-dioxide-3,3-diyl)bis(naphthalene-1,4-diyloxy)]dibenzene-1,2-dicarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 3,3',4,4'-diphenylsulfonetetracarboxylic 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, and 4,4'-[spiro(xanthene-9,9'-fluorene)-3,6-diylbis(oxycarbonyl)]diphthalic acid, and acid anhydrides thereof. Among these, dianhydrides having two acid anhydride structures are preferred, and 4,4'-(2,2-hexafluoroisopropylidene)diphthalic dianhydride and 4,4'-oxydiphthalic dianhydride are particularly preferred. The aromatic tetracarboxylic acids may be used alone or in combination of two or more. When heat resistance is important, the copolymerization amount of the aromatic tetracarboxylic acids is, for example, preferably 50% by mass or more of the total tetracarboxylic acids, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more, and may even be 100% by mass.

[0060] 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, and bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid. carboxylic 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-methanonaphthalene-2,3,6,7-tetracarboxylic acid, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane -5,5'',6,6''-tetracarboxylic acid (synonym: 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 (synonym: norbornane-2-spiro pyro-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, and norbornane-2-spiro-α-(methylcyclohexanone)-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, and acid anhydrides thereof. Among these, dianhydrides having two acid anhydride structures are preferred, and in particular, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclohexanetetracarboxylic dianhydride, and 1,2,4,5-cyclohexanetetracarboxylic dianhydride are preferred, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2,4,5-cyclohexanetetracarboxylic dianhydride are more preferred, and 1,2,3,4-Cyclobutanetetracarboxylic dianhydride is more preferred. These may be used alone or in combination of two or more. When transparency is important, the copolymerization amount of the alicyclic tetracarboxylic acids is, for example, preferably 50% by mass or more of the total tetracarboxylic acids, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more, and may even be 100% by mass.

[0061] Examples of tricarboxylic acids include aromatic tricarboxylic acids such as trimellitic acid, 1,2,5-naphthalenetricarboxylic acid, diphenylether-3,3',4'-tricarboxylic acid, and diphenylsulfone-3,3',4'-tricarboxylic acid, hydrogenated versions of these aromatic tricarboxylic acids such as hexahydrotrimellitic acid, alkylene glycol bistrimellitates such as ethylene glycol bistrimellitate, propylene glycol bistrimellitate, 1,4-butanediol bistrimellitate, and polyethylene glycol bistrimellitate, and monoanhydrides and esters thereof. Among these, monoanhydrides having one acid anhydride structure are preferred, with trimellitic anhydride and hexahydrotrimellitic anhydride being particularly preferred. These may be used alone or in combination.

[0062] Examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, and 4,4'-oxydibenzenecarboxylic acid, hydrogenated versions of these aromatic dicarboxylic acids such as 1,6-cyclohexanedicarboxylic acid, oxalic acid, succinic acid, glutaric acid, adipic acid, heptanedioic acid, octanedioic acid, azelaic acid, sebacic acid, undecadioic acid, dodecanedioic acid, and 2-methylsuccinic acid, as well as their acid chlorides and esters. Among these, aromatic dicarboxylic acids and their hydrogenated versions are preferred, with terephthalic acid, 1,6-cyclohexanedicarboxylic acid, and 4,4'-oxydibenzenecarboxylic acid being particularly preferred. The dicarboxylic acids may be used alone or in combination.

[0063] The diamines or isocyanates used to obtain colorless and highly transparent polyimides are not particularly limited, and aromatic diamines, aliphatic diamines, alicyclic diamines, aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and the like, which are commonly used in polyimide synthesis, polyamideimide synthesis, and polyamide synthesis, can be used. From the viewpoint of heat resistance, aromatic diamines are preferred, and from the viewpoint of transparency, alicyclic diamines are preferred. Furthermore, the use of aromatic diamines having a benzoxazole structure makes it possible to achieve high heat resistance, as well as a high elastic modulus, low heat shrinkage, and a low coefficient of linear expansion. Diamines and isocyanates can be used alone or in combination of two or more.

[0064] 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-hexafluoropropane, 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'-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)phenyl] 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]diphenyl sulfone, bis[4-{4-(4-aminophenoxy)pheno 1,3-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene, 1,4-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]benzoni tolyl, 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, etc. In addition, some or all of the hydrogen atoms on the aromatic ring of the aromatic diamine may be substituted with halogen atoms, alkyl or alkoxy groups having 1 to 3 carbon atoms, or cyano groups, and further some or all of the hydrogen atoms of the alkyl or alkoxy groups having 1 to 3 carbon atoms may be substituted with halogen atoms. 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-(m-aminophenyl)benzoxazole, 6-amino-2-(m-aminophenyl)benzoxazole, 2,2'-p-phenylenebis(5-aminobenzoxazole), ... Nylenebis(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,Examples of the aromatic diamines include 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, and 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole. Among these, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 4-amino-N-(4-aminophenyl)benzamide, 4,4'-diaminodiphenyl sulfone, and 3,3'-diaminobenzophenone are particularly preferred. The aromatic diamines may be used alone or in combination.

[0065] Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,4-diamino-2-methylcyclohexane, 1,4-diamino-2-ethylcyclohexane, 1,4-diamino-2-n-propylcyclohexane, 1,4-diamino-2-isopropylcyclohexane, 1,4-diamino-2-n-butylcyclohexane, 1,4-diamino-2-isobutylcyclohexane, 1,4-diamino-2-sec-butylcyclohexane, 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. The alicyclic diamines may be used alone or in combination.

[0066] 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, nate, 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, diphenylether-4,4'-diisocyanate, benzophenone-4,4'-diisocyanate, diphenyl Sulfone-4,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, naphthalene-2,6-diisocyanate, 4,4'-(2,2-bis(4-phenoxyphenyl)propane)diisocyanate, 3,3'- or 2,2'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'- or 2,2'-diethylbiphenyl-4,4'-diisocyanate aromatic diisocyanates such as 4,4'-biphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, and 3,3'-diethoxybiphenyl-4,4'-diisocyanate, and diisocyanates obtained by hydrogenating any of these (for example, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate).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 from the viewpoints of low moisture absorption, dimensional stability, cost, and polymerizability. The diisocyanates may be used alone or in combination.

[0067] In this embodiment, the polymer film is preferably a polyimide film, which has excellent heat resistance.

[0068] The thickness of the polymer film is preferably 3 μm or more, more preferably 7 μm or more, even more preferably 14 μm or more, and even more preferably 20 μm or more. There is no particular upper limit to the thickness of the polymer film, but for use as a flexible electronic device, it is preferably 250 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less.

[0069] The average coefficient of linear expansion (CTE) of the polymer film between 30°C and 250°C is preferably 50 ppm / K or less, more preferably 45 ppm / K or less, even more preferably 40 ppm / K or less, even more preferably 30 ppm / K or less, and particularly preferably 20 ppm / K or less. It is also preferably -5 ppm / K or more, more preferably -3 ppm / K or more, and even more preferably 1 ppm / K or more. A CTE within this range can minimize the difference in the coefficient of linear expansion between the polymer film and a typical support (inorganic substrate), preventing peeling between the polymer film and the inorganic substrate or warping of the support during a heat treatment process. Here, CTE is a factor that represents reversible expansion and contraction with temperature. The CTE of the polymer film refers to the average value of the CTE in the coating direction (MD) and the transverse direction (TD) of the polyamic acid.

[0070] 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, even more preferably 5 or less, and still more preferably 3 or less. There is no particular lower limit for the yellowness index of the transparent polyimide, but for use as a flexible electronic device, it is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more.

[0071] When the polymer film is a transparent polyimide film, the haze is preferably 1.0 or less, more preferably 0.8 or less, even more preferably 0.5 or less, and even more preferably 0.3 or less. There is no particular lower limit, but industrially, there is no problem if it is 0.01 or more, and even if it is 0.05 or more, there is no problem.

[0072] The heat shrinkage of the polymer film between 30° C. and 500° C. is preferably ±0.9% or less, and more preferably ±0.6% or less. The heat shrinkage is a factor that indicates irreversible expansion and contraction with respect to temperature.

[0073] The tensile breaking strength of the polymer film is preferably 60 MPa or more, more preferably 80 MPa or more, and even more preferably 100 MPa or more. There is no particular upper limit to the tensile breaking strength, but it is practically less than about 1000 MPa. When the tensile breaking strength is 60 MPa or more, it is possible to prevent the polymer film from breaking when peeling it from the inorganic substrate. The tensile breaking strength of the polymer film refers to the average value of the tensile breaking strength in the machine direction (MD) and the width direction (TD) of the polymer film.

[0074] The tensile breaking elongation of the polymer film is preferably 1% or more, more preferably 5% or more, and even more preferably 10% or more. When the tensile breaking elongation is 1% or more, the film has excellent handleability. The tensile breaking elongation of the polymer film refers to the average value of the tensile breaking elongation in the machine direction (MD) and the width direction (TD) of the polymer film.

[0075] The tensile modulus of the polymer film is preferably 2.5 GPa or more, more preferably 3 GPa or more, and even 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 handleability. The tensile modulus is preferably 20 GPa or less, more preferably 15 GPa or less, and even 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. The tensile modulus of the polymer film refers to the average value of the tensile modulus in the machine direction (MD) and the width direction (TD) of the polymer film.

[0076] The thickness unevenness of the polymer film is preferably 20% or less, more preferably 12% or less, even 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 thickness unevenness of the film can be calculated, for example, by measuring the film thickness at approximately 10 randomly selected positions on the film to be measured using a contact film thickness meter, and then using the following formula: Film thickness unevenness (%) = 100 x (maximum film thickness - minimum film thickness) ÷ average film thickness

[0077] The polymer film is preferably obtained in the form of a long polymer film wound up during production, with a width of 300 mm or more and a length of 10 m or more, and more preferably in the form of a rolled polymer film wound around a winding core. When the polymer film is wound up in a roll, it can be easily transported in the form of a rolled heat-resistant polymer film. Furthermore, it is possible to produce a laminate using a roll-to-roll process.

[0078] In order to ensure the handling properties and productivity of the polymer film, it is preferable to add or contain approximately 0.01 to 3 mass % of a lubricant (particles) having a particle diameter of approximately 10 to 1000 nm to the polymer film, thereby imparting fine irregularities to the surface of the polymer film and ensuring slipperiness.

[0079] <Inorganic substrate> Examples of the inorganic substrate include glass plates, semiconductor wafers, metal plates, and ceramic plates. Examples of the glass plate include quartz glass, high silica glass (96% silica), soda-lime glass, lead glass, aluminoborosilicate glass, borosilicate glass (Pyrex®), alkali-free borosilicate glass, borosilicate glass (microsheet), and aluminosilicate glass. Among these, those with a linear expansion coefficient of 5 ppm / K or less are preferred. Commercially available products include liquid crystal glass such as Corning® 7059, Corning® 1737, and EAGLE, AN100 from Asahi Glass Co., Ltd., OA10 and OA11 from Nippon Electric Glass Co., Ltd., and AF32 from SCHOTT. Examples of the semiconductor wafer include silicon wafers, germanium wafers, silicon-germanium wafers, gallium-arsenic wafers, aluminum-gallium-indium wafers, nitrogen-phosphorus-arsenic-antimony wafers, SiC wafers, InP (indium phosphide), InGaAs wafers, GaInNAs wafers, LT wafers, LN wafers, zinc oxide wafers, ZnO wafers, cadmium telluride wafers, and zinc selenide wafers. Examples of the metal plates include single-element metals such as W, Mo, Pt, Fe, Ni, and Au, and alloys such as Inconel, Monel, nimonic, copper carbon, Fe-Ni-based Invar alloys, Super Invar alloys, and various stainless steels. Nonwoven fabrics made of these metals may also be used. When using metal plates in the present invention, various stainless steels are preferred. Multilayer metal plates, which are formed by adding other metal or ceramic layers to these metals, are also included. Examples of the ceramic plates include single or composite sintered bodies of alumina, magnesia, calcia, silicon nitride, boron nitride, aluminum nitride, and beryllium oxide. When a ceramic substrate is used in the present invention, it is preferable to use a ceramic substrate whose surface has been smoothed by glass glaze treatment. These inorganic substrates may also be used in a rolled form as long products with a width of 300 mm or more and a length of 10 m or more. Rolled substrates not only facilitate transportation but also enable the production of laminates using a roll-to-roll process.

[0080] The thickness of the inorganic substrate is not particularly limited, but from the viewpoint of ease of handling, it is preferably 10 mm or less, more preferably 3 mm or less, and even more preferably 1.3 mm or less. The lower limit of the thickness is not particularly limited, but it is preferably 0.005 mm or more, more preferably 0.01 mm or more, and even more preferably 0.02 mm or more.

[0081] The laminate of this embodiment preferably has a 90° peel strength (adhesion strength) of 0.2 N / cm or more, more preferably 0.5 N / cm or more, and even more preferably 1.0 N / cm or more after heating at 200°C for 1 hour. If the 90° peel strength after heating is 0.2 N / cm or more, unintentional peeling of the second substrate (e.g., inorganic substrate) can be prevented when a device is formed on the first substrate (e.g., polymer film) or when each substrate is processed by etching or the like. Furthermore, the laminate preferably has a 90° peel strength of 10 N / cm or less, more preferably 8 N / cm or less, and even more preferably 6 N / cm or less after heating at 200° C. for 1 hour. If the 90° peel strength after heating is 10 N / cm or less, after forming a device on a first substrate (e.g., a polymer film), it becomes possible to easily peel off a second substrate (e.g., an inorganic substrate).

[0082] The laminate of this embodiment preferably has a 90° peel strength (adhesion strength) before heating of 0.1 N / cm or more, more preferably 0.2 N / cm or more, and even more preferably 0.3 N / cm or more. If the 90° peel strength before heating is 0.1 N / cm or more, peeling between the first substrate and the second substrate can be prevented. The laminate preferably has a 90° peel strength before heating of 6 N / cm or less, more preferably 4 N / cm or less, and even more preferably 2 N / cm or less. If the 90° peel strength before heating is 6 N / cm or less, peeling after heating can be easily achieved when desired.

[0083] 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 in the air at 110°C for 60 minutes (initial peel strength). The 90° peel strength after heating is the value of the laminate obtained by measuring the 90° peel strength before heating and then further heat-treating the laminate at 200°C for 1 hour (peel strength after heat treatment at 200°C).

[0084] The method for manufacturing the laminate according to this embodiment includes the steps of: A step A of preparing a first substrate and a second substrate; A 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; a 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 has been supplied.

[0085] In the method for manufacturing the laminate, first, a first substrate and a second substrate are prepared (Step A). ​​The first substrate and the second substrate have already been explained in the section on the laminate, so explanations thereof will be omitted here.

[0086] Also, 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 is 1 It can be measured by H-NMR. The ratio of the integrated values ​​of the peaks derived from the alkyl chains in the silane coupling agent to the peaks derived from the alcohol was calculated, and this was taken as the alcohol content (mol %) relative to the silane coupling agent.

[0087] In step B, first, the silane coupling agent and water are mixed and stirred until the hydrolysis reaction is complete. The stirring time is usually within the range of 1 hour to 5 hours at room temperature. The concentration of the silane coupling agent in the mixed solution is preferably 17 wt% to 80 wt%. By preparing the mixed solution at the above mixing ratio, the reaction of the silane coupling agent can be effectively promoted. After stirring, the alcohol is removed from the liquid containing the silane coupling agent, water, and alcohol. Examples of a method for removing the alcohol from the liquid containing the silane coupling agent, water, and alcohol include fractional distillation. Specifically, the alcohol can be removed from the liquid containing the silane coupling agent, water, and alcohol using an evaporator or the like. In this manner, 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 can be prepared.

[0088] However, the step B in the present invention is not limited to the above example. In the step B, a mixed solution from which the alcohol has been removed in advance may be used as the mixed solution containing the silane coupling agent and water.

[0089] The silane coupling agent in the mixed solution is 29 When 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, and the total ratio of Si having the following T0 structure, the following T1 structure, the following T2 structure, and the following T3 structure is Y, it is preferable that X / Y is 81 or more. However, in the following T0 structure, T1 structure, T2 structure, and T3 structure, Z is C n H 2n is a divalent alkyl chain represented by m H 2m+1 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).

[0090] 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.

[0091] [ka]

[0092] [ka]

[0093] [ka]

[0094] [ka]

[0095] When the X / Y ratio is 81 or more, the hydrolysis of the silane coupling agent progresses to a certain extent, resulting in an oligomer state and the generation of silanol groups. The silanol groups bond with reactive groups (e.g., OH groups) on the first substrate and / or the second substrate. As a result, the amount of lifting can be further reduced.

[0096] The X / Y ratio is more preferably equal to or greater than 82, and even more preferably equal to or greater than 85. The larger the X / Y ratio, the better, and it is, for example, 99 or less. The X / Y is a value determined by the method described in the Examples.

[0097] Next, the mixed solution is supplied onto the first substrate and / or the second substrate (step C). As a method for supplying the mixed solution onto the first substrate and the second substrate, a conventionally known method such as dropping or various solution coating methods using a bar coater or the like can be used.

[0098] Next, the first substrate and the second substrate after 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.

[0099] As a lamination method, a pressing method, a roll lamination method, or the like 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 applying heat during pressure application. In this embodiment, pressing or roll laminating under atmospheric pressure is preferred, and a method using a roll (such as roll lamination) is particularly preferred because it allows lamination while gradually pushing out excess mixed solution from the adhesive interface.

[0100] The pressure during lamination is preferably 0.2 kgf / cm or more, more preferably 0.4 kgf / cm or more, in terms of linear pressure. By laminating the substrates at a linear pressure of 0.2 kgf / cm or more, the substrates can be well adhered to each other. Furthermore, the pressure during lamination is preferably 2.0 kgf / cm or less in linear pressure, more preferably 1.8 kgf / cm or less. By laminating the substrates 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.

[0101] Thereafter, a heat treatment is carried out to promote the reaction of the silane coupling agent, thereby bonding the first substrate and the second substrate together. The heat treatment may be appropriately set within a range that allows the first substrate and the second substrate to be suitably bonded. The heat treatment is not particularly limited, but may be divided into two stages: an aging treatment and a reaction treatment. The aging treatment may be performed at a temperature of 25° C. or higher and 65° C. or lower for 1 hour or longer and 48 hours or shorter. The reaction treatment may be performed at a temperature of 80° C. or higher and 110° C. or lower for 1 hour or longer and 48 hours or shorter.

[0102] As a result of the above, a laminate is obtained in which the first substrate, the silane coupling agent layer, and the second substrate are laminated in this order. According to the method for producing the laminate, the alcohol content in the mixed solution is 1 mol % or less relative to the silane coupling agent. Therefore, when the first substrate and the second substrate are bonded together after the mixed solution is supplied, the amount of alcohol trapped within the laminate is small. As a result, the amount of lifting can be reduced. As a result, the adhesive strength of the resulting laminate does not decrease significantly even after heating.

[0103] The method for manufacturing a laminate according to this embodiment has been described above.

[0104] In the above-described embodiment, a laminate in which a first substrate, a silane coupling agent layer, and a 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 may be 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 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. The third substrate may be the heat-resistant polymer film described above or the inorganic substrate described above.

[0105] When 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, it is preferable that the floating portions between the first substrate and the second substrate satisfy [B1]≧[A1], [B2]≧[A2], the number of B1 is 20 or less, and the number of B2 is 4.0 mm or less.

[0106] Furthermore, when 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, it is preferable that the floating between the first substrate and the second substrate satisfies "[B1] / [A1] is 1.5 or less" and "[B2] / [A2] is 2.0 or less", and that the floating between the second substrate and the third substrate satisfies "[B1] / [A1] is 1.5 or less" and "[B2] / [A2] is 2.0 or less".

[0107] When 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, its 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 laminated is prepared, a mixed solution containing a silane coupling agent and water is supplied onto the second substrate and / or a separately prepared third substrate, and the second substrate and the third substrate after the mixed solution has been supplied are bonded together. [Example]

[0108] The present invention will be described in detail below using examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention.

[0109] 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, manufactured by Shin-Etsu Chemical Co., Ltd.: KBM-903), and the mixture was stirred at room temperature (25°C) for 3 hours. After that, using an evaporator equipped with a 30°C water bath, the generated alcohol was removed from the stirred solution over 1 hour, yielding silane coupling agent solution 1 (mixed solution).

[0110] <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 × 520 mm, arithmetic mean roughness (Ra): 120 nm). Next, a polyimide film (manufactured by Xenomax Japan Co., Ltd., product name: XENOMAX, thickness 15 μm, 500 mm × 500 mm) was laminated onto the SUS substrate onto which the silane coupling agent solution 1 had been dropped using a laminator at a linear pressure of 1.5 kgf / cm. Excess silane coupling agent solution 1 was pushed out by this lamination. The resulting laminate was subjected to an aging treatment in air at 40°C for 12 hours, and further subjected to a heat treatment in air at 110°C for 60 minutes to obtain a laminate according to Example 1. 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 Keyence laser microscope (product name: OPTELICS HYBRID). The measurement was carried out under the following conditions. The center of the substrate was used as the observation area, and the center of the observation area was also used as the evaluation area to measure the surface roughness of the substrate. Evaluation was carried out in one observation area per sample. The same measurements were also carried out for the substrates of the following examples (except for glass substrates). Observation area: 300 μm x 300 μm Evaluation area: 150 μm x 150 μm Observation magnification: 50x

[0111] Example 2 <Preparation of silane coupling agent solution> A 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 in Example 1, except that silane coupling agent solution 2 was used.

[0112] Example 3 <Preparation of silane coupling agent solution> A 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 in Example 1, except that silane coupling agent solution 3 was used.

[0113] Example 4 <Preparation of silane coupling agent solution> A silane coupling agent solution 4 was obtained in the same manner as in Example 3, except that 3-aminopropyltriethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.: KBE-903 (molecular formula: (C2H5O)3SiC3H6NH2), was used as the silane coupling agent. The reason why the molar ratio of [alcohol] / [silane coupling agent] differs between Example 3 and Example 4 is because the molecular weights of the silane coupling agents are 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.

[0114] Example 5 <Preparation of laminate> Instead of a SUS substrate, a copper substrate (Furukawa Electric Co., Ltd. electrolytic copper foil GTS-SD, thickness 105 μm, 520 mm × 520 mm, arithmetic mean roughness (Ra): 400 nm) was used. A laminate according to Example 5 was obtained in the same manner as in Example 3, except that the following was used.

[0115] Example 6 <Preparation of silane coupling agent solution> A 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> The laminate of Example 6 was obtained in the same manner as in Example 3, except that a glass substrate (thickness 0.7 mm, 520 mm × 520 mm, arithmetic mean roughness (Ra): 0.2 nm): OA10G manufactured by Nippon Electric Glass Co., Ltd.) was used instead of the SUS substrate, and silane coupling agent solution 5 was used instead of silane coupling agent solution 3. The arithmetic mean roughness (Ra) of glass surfaces was measured using a scanning probe microscope with surface property evaluation capabilities (SII NanoTechnology Inc., "SPA300 / nanonavi"). Measurements were performed in DFM mode using an SII NanoTechnology Inc. "DF3" or "DF20" cantilever and an SII NanoTechnology Inc. "FS-20A" scanner. The scanning area was 10 μm square, and the measurement resolution was 512 × 512 pixels. After performing secondary tilt correction on the measured image using the instrument's software, other flattening processes (e.g., flattening) were used as appropriate if noise was present in the measurement. The Ra value was calculated using the instrument's software. Measurements were performed at three random locations to determine the Ra value, and the average of these values ​​was used.

[0116] Example 7 <Preparation of laminate> Instead of the SUS substrate, a SUS nonwoven fabric (thickness 35 μm, 520 mm × 520 mm, fiber diameter 5 μm, basis weight 5.1 g / cm) was used as the second substrate. 2 A laminate according to Example 7 was obtained in the same manner as in Example 6, except that ) was used.

[0117] (Comparative Example 1) <Preparation of silane coupling agent solution> A 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.

[0118] (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, Shin-Etsu Chemical Co., Ltd.: KBM-903) and stirred at room temperature (25°C) for 3 hours to obtain silane coupling agent solution 7 (mixed solution). <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.

[0119] (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.

[0120] <Measurement of the alcohol content of a silane coupling agent solution> The alcohol / silane coupling agent ratio in the silane coupling agent solution is 1 Measurement was performed by H-NMR. 20% by mass of heavy water was added to the silane coupling agent solution. Immediately after dilution with heavy water, 1 H-NMR measurements were carried out. The alcohol content (mol %) relative to the silane coupling agent was determined from the ratio of the integral value of the peak near 2.6 ppm, which is one of the CH2 peaks derived from the silane coupling agent, to the integral value of the peak near 3.2 to 3.5 ppm, which is CH3 peak derived from methanol. Specifically, it was calculated using the following formula. Alcohol content (mol%) relative to the silane coupling agent = [(integral value of the CH3 peak derived from methanol / 3)] / [(integral value of the CH2 peak in the silane coupling agent) / 2)] The alcohol content relative to the silane coupling agent in the silane coupling agent solution of Example 1 was 0.9 mol %. In Example 4, the ratio was determined using the peak of CH3 derived from ethanol at around 1.2 ppm. The results are shown in Table 1. (Measurement conditions) Equipment: Fourier transform nuclear magnetic resonance spectrometer (Bruker Japan, AVANCE NEO 600 model) Measurement solution: Mix sample solution and heavy water in an 80 / 20 vol ratio 1 H resonance frequency: 600.134MHz Detection pulse flip angle: 30° Data acquisition time: 3 to 4 seconds Delay time: 1 second Accumulation count: 10 to 40 times Measurement temperature: 30℃

[0121] <Silane coupling agent solution 29 Si-NMR measurement> 20% by mass of heavy water was added to the silane coupling agent solution. Immediately after dilution with heavy water, 29 Si-NMR measurements were carried out. The contents (%) of Si having the T0 structure, Si having the T1 structure, Si having the T2 structure, and Si having the T3 structure were 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 contents (%) of T0 and T1, and the total contents (%) of T2 and T3. The total contents (%) of T2 and T3 correspond to the aforementioned X / Y. (Measurement conditions) Equipment: Fourier transform nuclear magnetic resonance spectrometer (Bruker Japan, AVANCE NEO 600 model) Measurement solution: Mix sample solution and heavy water in an 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 number: 30℃ Accumulation count: 100 to 500 times

[0122] <Measurement of float before heating> The laminates of the examples and comparative examples were measured at a widthwise center of 2,500 cm 2The laminate was cut into a size of (50 cm x 50 cm). The cut-out laminate was visually counted for the number of bubbles (number of bubbles) with a diameter of 0.5 mm or more. This number was designated A1. Next, the diameter of the A1 bubbles was measured using a digital microscope (model name: VHX-970F, manufactured by Keyence Corporation), and the average was designated A2 mm. The size of the laminate is 2,500 cm 2 If it is smaller than 2,500cm, measure the entire surface of the laminate and count the lift. 2 The calculation was recalculated to the equivalent number of pieces.

[0123] <Measurement of floating after heating> The laminate used for the lift measurement before heating was heated in air at 200°C for 1 hour. The heated laminate was visually counted for the number of lifts (number of bubbles) with a diameter of 0.5 mm or more, and this number was designated B1. Next, the diameters of the B1 lifts were measured using a digital microscope (model name: VHX-970F, manufactured by Keyence Corporation), and the average was designated B2 mm. The size of the laminate is 2,500 cm 2 If it is smaller than 2,500cm, measure the entire surface of the laminate and count the lift. 2 The calculation was recalculated to the equivalent number of pieces.

[0124] A1, A2, B1, and B2 are shown in Table 1.

[0125] <90 degree peel strength> The laminates of the examples and comparative examples were heated for 1 hour at 200° C. Thereafter, the 90-degree peel strength was measured according to the 90-degree peel method specified in JIS K6854-1:1999. Device name: Shimadzu Autograph AG-IS Measurement temperature: room temperature Peeling speed: 100mm / min Atmosphere: Atmospheric Measurement sample width: 10mm

[0126] [Table 1]

Claims

1. A laminate in which a first substrate, a silane coupling agent layer, and a second substrate are laminated in this order, the first substrate is a polyimide film, the second substrate is a metal substrate, the silane coupling agent constituting the silane coupling agent layer has an amino group, A laminate characterized in that, after the first substrate and the second substrate are bonded together and then heat-treated at 110°C for 60 minutes in an air atmosphere, 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.

2. 2. The laminate according to claim 1, wherein the 90° peel strength between the first substrate and the second substrate after the laminate according to claim 1 is further heated at 200°C for 1 hour is 0.2 N / cm or more and 10 N / cm or less.

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