Layered body including inorganic substrate and polyamic acid cured product

Abstract

To obtain a layered body including glass and a polyamic acid heat-cured product, which is readily releasable from an inorganic substrate after being heated at 250°C.SOLUTION: There is provided a layered body including an inorganic substrate and a polyamic acid heat-cured product, wherein a weight average molecular weight of the polyamic acid is 30,000 or more, a peel strength between the inorganic substrate and the polyamic acid heat-cured product layer is 0.3 N / cm or less after the layered body is heated at 250°C, and the polyamic acid heat-cured product contains a specific double-decker silsesquioxane derivative.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a laminate in which a high heat-resistant film such as a polyimide-based resin is formed on an inorganic substrate and a method for manufacturing a flexible device. The laminate of the present invention is useful, for example, in manufacturing a flexible device in which an electronic element is formed on the surface of a flexible substrate and a flexible wiring board.

Background Art

[0002] Conventionally, in the field of flat panel displays (FPDs) such as liquid crystal displays (LCDs), plasma display panels (PDPs), organic EL displays (OLEDs), and electronic devices such as electronic paper, those in which electronic elements are formed on a substrate (inorganic substrate) mainly made of an inorganic material such as a glass substrate have been used. However, since inorganic substrates are rigid and lack flexibility, there is a problem that they are difficult to be made flexible.

[0003] Therefore, a method of using an organic polymer material such as polyimide having flexibility and heat resistance as a substrate has been proposed. That is, a technique in which a high heat-resistant film having flexibility is laminated on an inorganic substrate used as a carrier, and this high heat-resistant film is used as a substrate for forming an electronic element or a wiring substrate has been put into practical use. Here, for example, when a glass substrate having excellent light transmittance is used as the inorganic substrate, the inspection process during the formation of the electronic element and the production of the wiring substrate becomes easy, and there is an advantage that the equipment for producing flexible devices for forming electronic elements on the existing glass substrate can be directly diverted.

[0004] In an inorganic substrate on which a flexible substrate layer made of such a high heat-resistant film is laminated, since the inorganic substrate is used as a substrate for the carrier, after forming an electronic element on the surface of the high heat-resistant film, it is necessary to finally peel and separate the high heat-resistant film from the inorganic substrate. Therefore, good peelability is required after forming the electronic element.

[0005] As an industrial method for peeling a high heat-resistant film firmly adhered to an inorganic substrate from the inorganic substrate, for example, a method of irradiating a laser beam on the interface of a high heat-resistant film such as a polyimide-based resin in contact with a glass substrate (Patent Document 1), a method of heating the interface of a polyimide film in contact with a glass substrate by Joule heat (Patent Document 2), a method of induction heating (Patent Document 3), a method of irradiating flash light from a xenon lamp (Patent Document 4), etc., methods for peeling have been proposed. However, these methods have problems in that the process is complicated and requires a long time, and the equipment is expensive, resulting in high costs. In addition, there is a method of casting a solution of a polyimide precursor (polyamic acid) on an inorganic substrate and thermally imidizing it to obtain a laminate (Patent Document 5). However, in this method, the adhesion between the inorganic substrate and the polyimide film is strong, and it is difficult to mechanically peel them. On the other hand, even in a method of adhering a polyimide film to an inorganic substrate with a relatively weak force using a silane coupling agent (Patent Document 6), the peeling strength between the inorganic substrate and the polyimide film is as strong as 1 N / cm or more, and it has been difficult to mechanically peel the polyimide film from the inorganic substrate without damaging the device formed on the surface.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, the present invention aims to solve the above problems by providing a laminate comprising an inorganic substrate and a thermoset of polyamic acid (hereinafter also simply referred to as a laminate), wherein the thermoset of polyamic acid can be mechanically peeled off from the laminate.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the present inventors have found that by using a polyamic acid having a weight average molecular weight of a certain value or more, the thermoset of the polyamic acid can be easily peeled off from the inorganic substrate, and the above problems are solved, leading to the completion of the present invention.

[0009] That is, the present invention includes the following configurations. [1] A laminate comprising an inorganic substrate and a thermoset of polyamic acid, wherein the weight average molecular weight of the polyamic acid is 30,000 or more, and the peel strength between the inorganic substrate and the thermoset layer of polyamic acid after heating the laminate at 250 °C is 0.3 N / cm or less. [2] The laminate according to [1], wherein the CTE of the thermoset of polyamic acid is 50 ppm / K or less. [3] The laminate according to [1] or [2], wherein the thermoset of polyamic acid is polyimide. [4] The laminate according to any one of [1] to [3], wherein the thermoset of polyamic acid is colorless transparent polyimide. [5] The laminate according to any one of [1] to [4], having a silane coupling agent condensation layer between the inorganic substrate and the thermoset layer of polyamic acid. [6] The laminate according to [5], wherein the thickness of the silane coupling agent condensation layer is 0.1 nm to 200 nm. [7] The laminate according to any one of [1] to [6], wherein the weight average molecular weight of the polyamic acid is 60,000 or more.

[0010] The present invention can further include the following configurations. [8] The laminate according to [1] to [7], wherein the thermoset of the polyamic acid contains one or more structures selected from the group consisting of the structure of Formula 1, the structure of Formula 2, and the structure of Formula 3. [Advantages of the Invention]

[0011] In the laminate and the method for producing the laminate of the present invention, the film made of the thermoset of the polyamic acid can be easily peeled off mechanically from the inorganic substrate. Further, since the molecular weight of the polyamic acid is sufficiently high, for example, when the polyamic acid is applied to the inorganic substrate and another film is laminated thereon, it can be diluted to a low concentration, and a very thin layer of the polyamic acid can be formed on the surface of the inorganic substrate. Therefore, even if there is a difference in the linear thermal expansion coefficient between the film and the thermoset of the polyamic acid, it has an excellent property that warping hardly occurs. [Brief Description of the Drawings]

[0012]

Figure 1

[0013] Hereinafter, embodiments of the present invention will be described.

[0014] <Polyamic Acid> The polyamic acid in the present invention can be produced by a known production method. That is, one or more tetracarboxylic acid anhydride components as raw materials and one or more diamine components are used, and polymerization is carried out in an organic solvent to obtain a polyamic acid solution. Preferred solvents for synthesizing polyamic acid are amide solvents, namely N,N-dimethylacetamide, N-methyl-2-pyrrolidone, etc., and N,N-dimethylacetamide is particularly preferably used. The reaction apparatus preferably includes a temperature adjusting device for controlling the reaction temperature. The reaction temperature is preferably 0°C or higher and 80°C or lower, and more preferably 15°C or higher and 60°C or lower, because hydrolysis of polyamic acid, which is the reverse reaction of polymerization, is suppressed and the viscosity of polyamic acid is likely to increase.

[0015] There are no particular restrictions on the diamines that make up the polyamic acid, and aromatic diamines, aliphatic diamines, alicyclic diamines, etc. that are usually used in polyimide synthesis can be used. From the perspective of heat resistance, aromatic diamines are preferred. The diamines may be used alone or in combination of two or more.

[0016] There are no particular limitations on the diamines, and examples include oxydianiline (bis(4-aminophenyl) ether), paraphenylenediamine (1,4-phenylenediamine), etc.

[0017] As the tetracarboxylic acids that make up 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) that are usually used in polyimide synthesis can be used. When these are acid anhydrides, the number of anhydride structures in the molecule may be 1 or 2, but those having 2 anhydride structures (dianhydrides) are preferred. The tetracarboxylic acids may be used alone or in combination of two or more.

[0018] The tetracarboxylic acid is not particularly limited, and examples thereof include pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and the like.

[0019] The thermoset of the polyamic acid is preferably a polyimide, and more preferably a colorless transparent polyimide.

[0020] A colorless transparent polyimide, which is an example of the thermoset of the polyamic acid in the present invention, will be described. Hereinafter, for the sake of avoiding complexity, it is simply referred to as a transparent polyimide. As for the transparency of the transparent polyimide, the total light transmittance is preferably 75% or more. More preferably, it is 80% or more, still more preferably 85% or more, even more preferably 87% or more, and 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, and more preferably 97% or less. The colorless transparent polyimide in the present invention preferably has a total light transmittance of 75% or more.

[0021] As the aromatic tetracarboxylic acids for obtaining a polyimide with high colorless transparency in the present invention, 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-diyl-oxy)]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-diyl-oxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(1,4-xylene-2,5-diyl-oxy)]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-diyl-oxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[4,4'-(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(naphthalene-1,4-diyl-oxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[4,4'-(3H-2,1-benzoxathiol-1,1-dioxide-3,3-diyl)bis(benzene-1,4-diyl-oxy)]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-diyl-oxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[(3H-2,1-benzoxathiol-1,1-dioxide-3,3-diyl)bis(1,4-xylene-2,5-diyl-oxy)]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-diyl-oxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[4,4'-(3H-2,1-Benzoxathiol-1,1-dioxide-3,3-diyl)bis(naphthalene-1,4-diyl oxy)]dibenzen-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, 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, and the like, and tetracarboxylic acids and their acid anhydrides thereof can be mentioned. Among these, dianhydrides having two acid anhydride structures are preferred, and in particular, 4,4'-(2,2-hexafluoroisopropylidene)diphthalic dianhydride and 4,4'-oxydiphthalic dianhydride are preferred. The aromatic tetracarboxylic acids may be used alone or in combination of two or more. When heat resistance is emphasized, the copolymerization amount of the aromatic tetracarboxylic acids is, for example, preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and may be 100% by mass.,

[0022] 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-methanonaphthalene-2,3,6,7-tetracarboxylic acid, norbornane-2-spiro-α-cyclopentanone-α’-spiro-2’’-norbornane-5,5’’,6,6’’-tetracarboxylic 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-5,5’’,6,6’’-tetracarboxylic acid, and the like, and their acid anhydrides. Also, acid anhydride group-containing double-decker type silsesquioxane derivatives represented by the structure of Formula 1, etc. are also included. 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, 1,2,4,5-cyclohexanetetracarboxylic dianhydride are preferred, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride are more preferred, 1,2,3,4-Cyclobutanetetracarboxylic dianhydride is more preferable. These may be used alone or in combination of two or more. When emphasizing transparency, the copolymerization amount of alicyclic tetracarboxylic acids is preferably, for example, 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and may even be 100% by mass.,

Chemical formula

[0023] Examples of tricarboxylic acids include aromatic tricarboxylic acids such as trimellitic acid, 1,2,5-naphthalenetricarboxylic acid, diphenyl ether-3,3',4'-tricarboxylic acid, diphenyl sulfone-3,3',4'-tricarboxylic acid, or hydrogenated products of the above aromatic tricarboxylic acids such as hexahydrotrimellitic acid, alkylene glycol bistrimellitates such as ethylene glycol bistrimellitate, propylene glycol bistrimellitate, 1,4-butanediol bistrimellitate, polyethylene glycol bistrimellitate, and their monohydrides, esterified products. Among these, monohydrides having one acid anhydride structure are preferred, and particularly, trimellitic anhydride and hexahydrotrimellitic anhydride are preferred. These may be used alone or in combination of a plurality.,

[0024] Examples of the dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, 4,4'-oxydibenzenecarboxylic acid, or hydrogenated products of the above aromatic dicarboxylic acids such as 1,6-cyclohexanedicarboxylic acid, oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, 2-methylsuccinic acid, and acid chlorides or esterified products thereof. Among these, aromatic dicarboxylic acids and their hydrogenated products are preferred, and particularly, terephthalic acid, 1,6-cyclohexanedicarboxylic acid, and 4,4'-oxydibenzenecarboxylic acid are preferred. The dicarboxylic acids may be used alone or in combination of two or more.

[0025] There are no particular restrictions on the diamines or isocyanates for obtaining the highly colorless and transparent polyimide in the present invention, and aromatic diamines, aliphatic diamines, alicyclic diamines, aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, etc. usually 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. Further, when using aromatic diamines having a benzoxazole structure, it becomes possible to exhibit high heat resistance, high elastic modulus, low heat shrinkage, and low linear expansion coefficient. The diamines and isocyanates may be used alone or in combination of two or more.

[0026] 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)-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'-diaminodiphenylsulfide, 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, 1,3-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, 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, an amino group-containing double-decker type silsesquioxane derivative represented by the structure of Formula 2, and the like. Further, some or all of the hydrogen atoms on the aromatic ring of the above aromatic diamine may be substituted with a halogen atom, an alkyl group or an alkoxyl group having 1 to 3 carbon atoms, or a cyano group, and furthermore, some or all of the hydrogen atoms of the alkyl group or alkoxyl group having 1 to 3 carbon atoms may be substituted with a halogen atom. Also, 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-aminobenzoxazol)-4-(6-aminobenzoxazol)benzene, 2,6-(4,4’-diaminodiphenyl)benz[1,2-d:5,4-d’]bisoxazole, 2,6-(4,4’-diaminodiphenyl)benz[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 can be mentioned. Among these, in particular, 2,2’-ditrifuluoromethyl-4,4’-diaminobiphenyl, 4-amino-N-(4-aminophenyl)benzamide, 4,4’-diaminodiphenylsulfone, and 3,3’-diaminobenzophenone are preferable. Incidentally, the aromatic diamines may be used alone or in combination of two or more.,

Chemical formula

[0027] Examples of the 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, 4,4’-methylenebis(2,6-dimethylcyclohexylamine), and the like. Among these, in particular, 1,4-diaminocyclohexane and 1,4-diamino-2-methylcyclohexane are preferable, and 1,4-diaminocyclohexane is more preferable. Incidentally, the alicyclic diamines may be used alone or in combination of two or more.,

[0028] Examples of the diisocyanates include aromatic diisocyanates such as 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, 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, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, 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 preferable in terms of low hygroscopicity, dimensional stability, price, and polymerizability. The diisocyanates may be used alone or in combination of two or more.

[0029] <Thermoset of polyamic acid> The thermoset of the polyamic acid of the present invention is obtained by heating and curing the polyamic acid. The layer of the thermoset of the polyamic acid (hereinafter also referred to as the thermoset layer of the polyamic acid or the thermoset film of the polyamic acid) may have a single-layer structure or a multi-layer (laminated) structure of two or more layers. When the thermoset layer of the polyamic acid has a multi-layer structure, the respective thermoset layers of the polyamic acid may have the same composition or different compositions. When the thermoset of the polyamic acid has a single-layer structure, the thermoset of the polyamic acid (melting point, glass transition temperature, yellowness index, total light transmittance, haze, CTE, etc.) refers to the value of the entire thermoset of the polyamic acid. When the thermoset of the polyamic acid has a multi-layer structure, the physical properties of the thermoset of the polyamic acid refer to the value of only the single layer in contact with the inorganic substrate. Therefore, the physical properties of the layer not in contact with the inorganic substrate (all layers other than the layer in contact with the inorganic substrate) are not restricted.

[0030] The average coefficient of thermal expansion (CTE) of the thermoset of polyamic acid between 30°C and 250°C is preferably 50 ppm / K or less. More preferably, it is 45 ppm / K or less, still more preferably 40 ppm / K or less, even more preferably 30 ppm / K or less, and particularly preferably 20 ppm / K or less. Also, it is preferably -5 ppm / K or more, more preferably -3 ppm / K or more, and still more preferably 1 ppm / K or more. When the CTE is within the above range, the difference in the coefficient of thermal expansion from a general support (inorganic substrate) can be kept small, and even when subjected to a process of applying heat, peeling of the thermoset of polyamic acid from the inorganic substrate 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 thermoset of the polyamic acid refers to the average value of the CTE in the coating direction (MD direction) and the CTE in the width direction (TD direction) of the polyamic acid. The method for measuring the CTE of the thermoset of the polyamic acid is according to the method described in the examples.

[0031] When the thermoset of the polyamic acid is a transparent polyimide, its yellowness index (hereinafter, also referred to as "yellowness index" or "YI") is preferably 10 or less, more preferably 7 or less, still 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 for use 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.

[0032] The light transmittance of the thermoset of polyamic acid in the present invention at a wavelength of 400 nm is preferably 70% or more, more preferably 72% or more, still more preferably 75% or more, and even more preferably 80% or more. The upper limit of the light transmittance at a wavelength of 400 nm of the thermoset of the transparent polyamic acid is not particularly limited, but for use as a flexible electronic device, it is preferably 99% or less, more preferably 98% or less, and still more preferably 97% or less.

[0033] The haze of the thermoset of the polyamic acid in the present invention is preferably 1.0 or less, more preferably 0.8 or less, still more preferably 0.5 or less, and even more preferably 0.3 or less. The lower limit is not particularly limited, but industrially, there is no problem as long as it is 0.01 or more, and it may be 0.05 or more.

[0034] The thermoset of the polyamic acid preferably has a melting point of 250 °C or higher, more preferably 300 °C or higher, still more preferably 400 °C or higher. Further, the glass transition temperature is preferably 200 °C or higher, more preferably 320 °C or higher, and still more preferably 380 °C or higher. In this specification, the melting point and the glass transition temperature are determined by differential scanning calorimetry (DSC). When the melting point exceeds 500 °C, it may be determined whether the melting point has been reached by visually observing the thermal deformation behavior when heated at the corresponding temperature. When the thermoset of the polyamic acid has a multilayer structure, the physical properties of the thermoset of the polyamic acid refer to the values of only the single layer in contact with the inorganic substrate. Therefore, the physical properties of the layer not in contact with the inorganic substrate (all layers other than the layer in contact with the inorganic substrate) are not limited. When measuring the physical properties of the layer in contact with the inorganic substrate, it is preferable to isolate only the layer in contact with the inorganic substrate. The method for isolating the layer is not particularly limited. For example, only the layer in contact with the inorganic substrate may be scraped out from the film having a multilayer structure with a cutter or the like, or it may be dissolved in a solvent in which only the layer not in contact with the inorganic substrate dissolves and removed. Further, when it is difficult to isolate only the layer in contact with the inorganic substrate, a layer having a single composition obtained by coating and baking only the layer whose physical properties are to be measured on the inorganic substrate may be evaluated.

[0035] When the thermoset of polyamic acid has a laminated structure of two or more layers, the thermoset layer of polyamic acid in contact with the inorganic substrate preferably contains a polyimide having one or more structures selected from the group consisting of the following formula 3, the following formula 4, and the following formula 5. Among the thermoset layers of polyamic acid, the total amount of polyimide having one or more structures selected from the group consisting of the following formula 3, the following formula 4, and formula 5 is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, particularly preferably 95% by mass or more, and may even be 100% by mass. By containing a polyimide having one or more structures selected from the group consisting of formula 3, formula 4, and formula 5 within the above range, the thermoset of polyamic acid can exhibit excellent CTE.

Chemical formula

Chemical formula

Chemical formula

[0036] The thickness of the thermoset layer of polyamic acid in the present invention is preferably 5 μm or more, more preferably 8 μm or more, still more preferably 15 μm or more, and even more preferably 20 μm or more. The upper limit of the thickness of the thermoset layer of polyamic acid is not particularly limited, but for use as a flexible electronic device, it is preferably 200 μm or less, more preferably 150 μm or less, and still more preferably 90 μm or less. If it is too thin, handling after device formation may be difficult, and if it is too thick, flexibility may be impaired.

[0037] The thickness non-uniformity of the thermoset layer of the polyamic acid is preferably 20% or less, more preferably 12% or less, still more preferably 7% or less, and particularly preferably 4% or less. When the thickness non-uniformity exceeds 20%, it tends to be difficult to apply to the narrow part. The thickness non-uniformity of the thermoset layer of the polyamic acid can be obtained, for example, after peeling the thermoset layer of the polyamic acid from the inorganic substrate, artificially extracting about 10 points of the position of the thermoset of the polyamic acid, measuring the thickness of the thermoset of the polyamic acid with a contact type film thickness meter, and calculating based on the following formula. Thickness non-uniformity (%) of the thermoset of the polyamic acid = 100×(maximum thickness - minimum thickness)÷average thickness

[0038] The thermoset of the polyamic acid may contain an imidization catalyst, inorganic fine particles, etc. as required. It is preferable to add the imidization catalyst, inorganic fine particles, etc. to the polyamic acid solution as required.

[0039] As the imidization catalyst, it is preferable to use a tertiary amine. As the tertiary amine, a heterocyclic tertiary amine is more preferable. Specific preferable examples of the heterocyclic tertiary amine include pyridine, 2,5-diethylpyridine, picoline, quinoline, isoquinoline, and the like. The usage amount of the imidization agent is preferably 0.01 to 2.00 equivalents, particularly 0.02 to 1.20 equivalents, based on the reaction site of the polyamic acid (polyimide precursor). When the amount of the imidization catalyst is less than 0.01 equivalent, the effect of the catalyst cannot be sufficiently obtained, which is not preferable. When it is more than 2.00 equivalents, the proportion of the catalyst not involved in the reaction increases, which is not preferable in terms of cost.

[0040] Examples of the inorganic fine particles include inorganic oxide powders such as particulate silicon dioxide (silica) powder and aluminum oxide powder, and inorganic salt powders such as particulate calcium carbonate powder and calcium phosphate powder. In the field of the present invention, since coarse grains of these inorganic fine particles may cause defects in subsequent processes, it is preferable that these inorganic fine particles are uniformly dispersed.

[0041] In the present invention, particularly, the thermoset of polyamic acid preferably has a laminated structure of two or more layers (multilayer structure). By forming a two-layer structure with materials (resins) having different physical properties, a laminate having various characteristics can be produced. Further, by laminating in a symmetric structure in the thickness direction (for example, transparent cured layer A / transparent highly heat-resistant cured layer B / transparent cured layer A), the balance of the CTE of the entire thermoset of polyamic acid becomes good, and a laminate less likely to warp can be obtained. Also, by making any one layer a layer having absorption in ultraviolet or infrared, it is possible to give characteristics to the spectral characteristics, control the incident and outgoing light by layers having different refractive indexes, and the like.

[0042] Since the molecular weight of polyamic acid affects the mechanical strength and peel strength of the obtained thermoset of polyamic acid (for example, polyimide), the average molecular weight of polyamic acid needs to be 30,000 or more in terms of weight average molecular weight measured by GPC (polyethylene glycol) conversion. Preferably it is 50,000 or more, more preferably 80,000 or more, and still more preferably 100,000 or more. If the weight average molecular weight of polyamic acid is 30,000 or more, the molecular terminals in the polyamic acid solution can be appropriately reduced, excessive bonding reaction with an inorganic substrate (especially a glass substrate) can be suppressed, and strong adhesion to the inorganic substrate can be suppressed. Also, it can suppress the thermoset of polyamic acid from becoming brittle and improve the handling with devices. The upper limit of the weight average molecular weight of polyamic acid is not particularly defined, but it is preferably substantially 1,000,000 or less, more preferably 500,000 or less, from the ease of the polymerization reaction and the like.

[0043] <Inorganic substrate> The inorganic substrate may be any plate-like substrate that can be used as a substrate made of an inorganic substance. For example, a glass plate, a ceramic plate, a semiconductor wafer, a metal-based one, and a composite of these glass plates, ceramic plates, semiconductor wafers, and metals, such as a laminate of these, a dispersion of these, or a material containing these fibers.

[0044] Examples of the glass plate include quartz glass, high-silica glass (96% silica), soda-lime glass, lead glass, aluminoborosilicate glass, borosilicate glass (Pyrex (registered trademark)), borosilicate glass (alkali-free), borosilicate glass (micro sheet), aluminosilicate glass, etc. Among these, those with a linear expansion coefficient of 5 ppm / K or less are desirable. If they are commercially available products, "Corning (registered trademark) 7059", "Corning (registered trademark) 1737", "EAGLE" manufactured by Corning Inc., which is glass for liquid crystal, "AN100" manufactured by Asahi Glass Co., Ltd., "OA10, OA11G" manufactured by Nippon Electric Glass Co., Ltd., "AF32" manufactured by SCHOTT, etc. are desirable.

[0045] The semiconductor wafer is not particularly limited, and examples include silicon wafers, germanium, silicon-germanium, gallium-arsenic, aluminum-gallium-indium, nitrogen-phosphorus-arsenic-antimony, SiC, InP (indium phosphide), InGaAs, GaInNAs, LT, LN, ZnO (zinc oxide), CdTe (cadmium telluride), ZnSe (zinc selenide), etc. Among them, the wafer preferably used is a silicon wafer, and particularly preferably a mirror-polished silicon wafer with a size of 8 inches or more.

[0046] Examples of the metal include single-element metals such as W, Mo, Pt, Fe, Ni, Au, and alloys such as Inconel, Monel, Nimonic, carbon copper, Fe-Ni-based Invar alloy, Super Invar alloy, etc. Also included are multilayer metal plates formed by adding other metal layers and ceramic layers to these metals. In this case, if the overall linear expansion coefficient (CTE) with the added layer is low, Cu, Al, etc. can also be used for the main metal layer. The metal used as the added metal layer is not limited as long as it has characteristics such as strong adhesion to the thermoset of polyamic acid, no diffusion, good chemical resistance and heat resistance, etc., and Cr, Ni, TiN, Cu containing Mo, etc. are given as suitable examples.

[0047] As the ceramic plate in the present invention, Al2O3, Mullite, ALN, SiC, crystallized glass, Cordierite, Spodumene, Pb―BSG+CaZrO3+Al2O3, Crystallized glass+Al2O 3、 It includes ceramics for substrates such as Crystallized Ca―BSG, BSG+Quartz, BSG+Al2O3, Pb―BSG+Al2O3, Glass―ceramic, and zero-dura materials.

[0048] The thickness of the inorganic substrate is not particularly limited, but from the perspective of handleability, a thickness of 10 mm or less is preferred, 3 mm or less is more preferred, and 1.3 mm or less is even more preferred. The lower limit of the thickness is not particularly limited, but preferably 0.07 mm or more, more preferably 0.15 mm or more, and even more preferably 0.3 mm or more. If it is too thin, it is easily damaged and handling becomes difficult. If it is too thick, it becomes heavy and handling becomes difficult.

[0049] Surface treatment may be performed for the purpose of improving the wettability and adhesiveness of the inorganic substrate. As the surface treatment agent to be used, coupling agents such as silane coupling agents, aluminum-based coupling agents, and titanate-based coupling agents can be used. In particular, excellent properties can be obtained when a silane coupling agent is used.

[0050] <Silane coupling agent (SCA)> In the laminate, it is preferable to have a layer of a silane coupling agent (also referred to as a silane coupling agent condensation layer) between the thermoset layer of polyamic acid and the inorganic substrate. In the present invention, the silane coupling agent refers to a compound containing 10 mass% or more of a Si (silicon) component. By using the silane coupling agent layer, the intermediate layer between the thermoset layer of polyamic acid and the inorganic substrate can be made thin, so that there are few degassing components during heating, it is difficult to elute even in a wet process, and even if elution occurs, it remains in a trace amount. The silane coupling agent preferably contains a large amount of silicon oxide component in order to improve heat resistance, and particularly preferably has heat resistance at a temperature of about 400°C. The thickness of the silane coupling agent layer is preferably 200 nm or less (0.2 μm or less). In the range of use as a flexible electronic device, 100 nm or less (0.1 μm or less) is preferable, more preferably 50 nm or less, and still more preferably 10 nm. When produced normally, it becomes about 0.10 μm or less. Also, in a process where it is desired to have as little silane coupling agent as possible, it can be used even at 5 nm or less. Since there is a possibility that the peel strength may decrease or a non-attached portion may occur partially when it is less than 0.1 nm, it is preferably 0.1 nm or more, and more preferably 0.5 nm or more.

[0051] The silane coupling agent in the present invention is not particularly limited, but those having an amino group or an epoxy group are preferred. Specific examples of the silane coupling agent 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-dimethyl-butylidene)propylamine, 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, 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-isocyanatopropyltriethoxysilane, tris-(3-trimethoxysilylpropyl)isocyanurate, chloromethylphenethyltrimethoxysilane, chloromethyltrimethoxysilane, and the like.Among these, preferred examples 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 Si and amino groups are connected by an aromatic group are desirable.

[0052] <Method for manufacturing a laminate> A laminate of an inorganic substrate and a thermoset of polyamic acid can be manufactured by casting the above-described polyamic acid solution onto the inorganic substrate and subjecting it to thermal imidization (thermosetting).

[0053] As the casting method of the polyamic acid solution, known methods can be used. For example, known casting methods such as the gravure coating method, spin coating method, silk screen method, dip coating method, bar coating method, knife coating method, roll coating method, die coating method, etc. can be mentioned.

[0054] As the polyamic acid solution, the polymerization solution described above may be used as it is, but the solvent may be removed or added as necessary. Solvents that can be used in the polyamic acid solution include, in addition to N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone, for example, dimethyl sulfoxide, hexamethylphosphoride, acetonitrile, acetone, and tetrahydrofuran. Further, as auxiliary solvents, xylene, toluene, benzene, diethylene glycol ethyl ether, diethylene glycol dimethyl ether, 1,2-bis-(2-methoxyethoxy)ethane, bis(2-methoxyethyl) ether, butyl cellosolve, butyl cellosolve acetate, propylene glycol methyl ether, and propylene glycol methyl ether acetate may be used in combination.

[0055] The polyamic acid of the present invention is preferably thermally imidized (thermally cured) at 300°C or higher and 450°C or lower. That is, the thermoset of the polyamic acid of the present invention is preferably obtained by thermally imidizing (thermally curing) the polyamic acid at 300 to 450°C.

[0056] Thermal imidization is a method of promoting the imidization reaction only by heating without the action of a dehydration ring-closing agent or the like. The heating temperature and heating time at this time can be appropriately determined. For example, the following can be done. First, in order to volatilize the solvent, it is heated at a temperature of 90 to 200 °C for 3 to 120 minutes. The heating atmosphere can be carried out under air, under reduced pressure, or in an inert gas such as nitrogen. As the heating device, known devices such as a hot air oven, an infrared oven, a vacuum oven, and a hot plate can be used. Next, in order to further promote imidization, it is heated at a temperature of 200 to 450 °C for 3 to 240 minutes. The heating conditions at this time are preferably gradually increased from a low temperature to a high temperature. Also, the maximum temperature is preferably in the range of 300 to 450 °C. If the maximum temperature is lower than 300 °C, thermal imidization is difficult to proceed, and the mechanical properties of the obtained polyimide film deteriorate, which is not preferable. If the maximum temperature is higher than 450 °C, thermal degradation of the polyimide proceeds and the properties deteriorate, which is not preferable. Also, depending on the type and thickness of the polyamic acid, the type and surface state of the inorganic substrate, and the heating conditions and heating method during heating, the film may naturally peel off from the inorganic substrate during the heat treatment. When natural peeling occurs, it becomes difficult to obtain a laminate having excellent properties, which is not preferable. Generally, the thicker the film, the easier it is for natural peeling to occur. Therefore, it is preferable to adjust the above-mentioned conditions for each thickness. Also, in order to suppress natural peeling, the operations of casting the polyamic acid solution and thermal imidization may be performed in multiple steps.

[0057] The content of the solvent contained in the thermoset of polyamic acid is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less. Since it is preferable that the content of the solvent is small, the lower limit is not particularly limited, but industrially, it may be 0.01% by mass or more, and may be 0.05% by mass or more.

[0058] In the present invention, when coating a polyamic acid solution on an inorganic substrate, a plurality of different polyamic acid solutions may be sequentially or simultaneously applied in multiple layers. The plurality of different polyamic acid solutions referred to here specifically refer to polyamic acid solutions with different compositions, polyamic acid solutions with different imidization rates, and polyamic acid solutions with different types and amounts of added inorganic particles and additives. Any polyamic acid solution other than the one directly contacting the inorganic substrate may be a polyimide solution with complete thermal imidization.

[0059] Coating of a plurality of polyamic acid solutions on an inorganic substrate can be carried out using, for example, a two-layer die coater. By using a multi-layer die coater or sequential coating, a laminate of a thermoset of polyamic acid having a multi-layer structure of two or more layers with an inorganic substrate can be obtained.

[0060] In the present invention, when coating a polyamic acid solution on an inorganic substrate, after coating the first layer on the inorganic substrate, the solvent is volatilized by heating at a temperature of 100 to 200 °C for 3 to 120 minutes, and then the second layer of polyamic acid solution may be coated thereon.

[0061] In the laminate of an inorganic substrate and a thermoset of polyamic acid in the present invention, after coating a polyamic acid solution on the inorganic substrate, a polyimide film is laminated before heating and then heated, and finally it may be a laminate of an inorganic substrate and polyimide.

[0062] In order to obtain the laminate of an inorganic substrate and a thermoset of polyamic acid in the present invention, a polyamic acid solution coated in a single layer or multiple layers in advance on another support is heated to form a self-supporting film, which is then laminated with the inorganic substrate and heated.

[0063] The laminate of the inorganic substrate and the thermoset of polyamic acid in the present invention can also be obtained by bonding a thermoset of polyamic acid, which has been previously formed into a single-layer or multi-layer film, to the inorganic substrate. The single-layer or multi-layer thermoset film of polyamic acid can be obtained by coating a polyamic acid solution on a support such as a metal belt or a resin film, drying it to form a self-supporting film, and then performing thermal imidization. The coating of the polyamic acid solution on the support may be a simultaneous multi-layer coating, or the first layer may be coated and dried, and then the polyamic acid solution may be coated, dried, and imidized thereon. Similarly, when laminating three or more layers of the polyamic acid solution, a multi-layer film can be obtained by repeating the coating and heating simultaneously or sequentially.

[0064] The laminate of the present invention can also be produced, for example, by the following procedure. At least one surface of the inorganic substrate is previously treated with a silane coupling agent, and the surface treated with the silane coupling agent is overlapped with the thermoset of polyamic acid in film form, and a laminate in which both are laminated by pressure can be obtained. Also, at least one surface of the thermoset of polyamic acid in film form is previously treated with a silane coupling agent, and the surface treated with the silane coupling agent is overlapped with the inorganic substrate, and a laminate can also be obtained by laminating both by pressure. Examples of the pressure method include normal pressing or laminating in the atmosphere or pressing or laminating in a vacuum. However, in order to obtain a stable peel strength over the entire surface, laminating in the atmosphere is desirable for a laminate of a large size (for example, over 200 mm). On the other hand, for a laminate of a small size of about 200 mm or less, pressing in a vacuum is preferable. The degree of vacuum is sufficient with a vacuum by an ordinary rotary oil pump, and about 10 Torr or less is sufficient. The preferable pressure is from 1 MPa to 20 MPa, and more preferably from 3 MPa to 10 MPa. If the pressure is high, there is a risk of damaging the substrate, and if the pressure is low, non-adhering portions may occur. The preferable temperature is from 90°C to 300°C, and more preferably from 100°C to 250°C. If the temperature is high, the thermoset of polyamic acid may be damaged, and if the temperature is low, the adhesive strength may be weak.

[0065] The shape of the laminate is not particularly limited and may be square or rectangular. Preferably, it is rectangular, and the length of the long side is preferably 300 mm or more, more preferably 500 mm or more, and even more preferably 1000 mm or more. The upper limit is not particularly limited, but industrially, 20000 mm or less is sufficient, and 10000 mm or less is also acceptable.

[0066] <Adhesive> Preferably, there is substantially no adhesive layer between the inorganic substrate and the thermoset of polyamic acid in the present invention. Here, the adhesive layer referred to in the present invention means one having a Si (silicon) component of less than 10% (less than 10% by mass) in mass ratio. Also, "substantially not used (not intervening)" means that the thickness of the adhesive layer intervening between the inorganic substrate and the thermoset of polyamic acid is preferably 0.4 μm or less, more preferably 0.3 μm or less, even more preferably 0.2 μm or less, particularly preferably 0.1 μm or less, and most preferably 0 μm.

[0067] It is necessary that the 90° peel strength between the inorganic substrate and the thermoset layer of polyamic acid after heating the laminate of the present invention at 250 °C for 60 minutes after the laminate is produced is 0.3 N / cm or less. Thereby, after forming a device on the thermoset layer of polyamic acid, the peeling between the thermoset layer of polyamic acid and the inorganic substrate becomes very easy. Therefore, a device connector capable of mass production can be manufactured, and the production of flexible electronic devices becomes easy. The peel strength is preferably 0.25 N / cm or less, more preferably 0.2 N / cm or less, even more preferably 0.15 N / cm or less, particularly preferably 0.1 N / cm or less. Also, it is preferably 0.01 N / cm or more. Since the laminate does not peel when forming a device on the thermoset layer of polyamic acid, it is more preferably 0.02 N / cm or more, even more preferably 0.03 N / cm or more, and particularly preferably 0.05 N / cm or more.

Examples

[0068] Hereinafter, the present invention will be described in detail using examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[0069] [Production Example 1 (Production of Polyimide Solution 1)] While introducing nitrogen gas into a reaction vessel equipped with a nitrogen inlet tube, a Dean-Stark tube, a reflux tube, a thermometer, and a stirrer, 19.86 parts by mass of 4,4'-diaminodiphenyl sulfone (4,4'-DDS), 4.97 parts by mass of 3,3'-diaminodiphenyl sulfone (3,3'-DDS), and 80 parts by mass of N,N-dimethylacetamide (DMAc) were added. Subsequently, 31.02 parts by mass of 4,4'-oxydiphthalic anhydride (ODPA), 24 parts by mass of GBL, and 13 parts by mass of toluene were added at room temperature, and then the internal temperature was raised to 160 °C and heated under reflux at 160 °C for 1 hour to perform imidization. After completion of imidization, the temperature was raised to 180 °C, and the reaction was continued while extracting toluene. After reacting for 12 hours, the oil bath was removed and the temperature was returned to room temperature, and DMAc was added so that the solid content became 20% by mass concentration, and polyimide solution 1 having a reduced viscosity of 0.70 dl / g was obtained.

[0070] [Production Example 2 (Production of Polyamic Acid Solution 1)] After purging the inside of a reaction vessel equipped with a nitrogen inlet tube, a reflux tube, and a stirrer with nitrogen, 22.73 parts by mass of 4,4'-diaminobenzanilide (DABAN), 201.1 parts by mass of N,N-dimethylacetamide (DMAc), and a dispersion obtained by dispersing colloidal silica as a lubricant in dimethylacetamide (manufactured by Nissan Chemical Industries, Ltd., "Snowtex (registered trademark) DMAC-ST-ZL") were added so that the silica (lubricant) became 0.4% by mass based on the total amount of the polymer solid content in the polyamic acid solution and completely dissolved. Then, 24.57 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added in portions as a solid, and then stirred at room temperature for 24 hours. Thereafter, 173.1 parts by mass of DMAc was added for dilution, and polyamic acid solution 1 having a solid content (NV) of 13% by mass and a reduced viscosity of 3.1 dl / g was obtained. When the weight average molecular weight (Mw) was measured under the following conditions, Mw was 100,000.

[0071] <Molecular weight measurement conditions> The weight average molecular weight (Mw) in the present invention was measured under the following conditions using TOSOH HLC-8420GPC. Column: TSKgel SuperAWM-Hx2 Column temperature: 40 °C Eluent: DMAc / LiBr (DMAc containing 30 mmol / L lithium bromide) Flow rate: 0.3 mL / min Injection volume: 10 μL Detector: RI Standard sample: PEG (polyethylene glycol)

[0072] 〔Production Example 3 (Production of polyamic acid solution 2)〕 After purging the inside of a reaction vessel equipped with a nitrogen inlet tube, a reflux tube, and a stir bar with nitrogen, 22.73 parts by mass of 4,4'-diaminobenzanilide (DABAN), 201.1 parts by mass of N,N-dimethylacetamide (DMAc), and a dispersion obtained by dispersing colloidal silica as a lubricant in dimethylacetamide (Nissan Chemical Industries, Ltd.'s "Snowtex (registered trademark) DMAC-ST-ZL") were added so that the silica (lubricant) was 0.4% by mass based on the total amount of polymer solids in the polyamic acid solution and completely dissolved. Then, 22.73 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added in portions as a solid, and the mixture was stirred at room temperature for 24 hours. Thereafter, 173.1 parts by mass of DMAc was added for dilution to obtain a polyamic acid solution 2 having a solid content (NV) of 12% by mass and a reduced viscosity of 8.1 dl / g. When Mw was measured in the same manner as in Production Example 2, it was 550,000.

[0073] 〔Production Example 4 (Production of polyamic acid solution 3)〕 After replacing the nitrogen in the reaction vessel equipped with a nitrogen introduction tube, a reflux tube, and a stirrer with nitrogen, 22.73 parts by mass of 4,4'-diaminobenzanilide (DABAN), 201.1 parts by mass of N,N-dimethylacetamide (DMAc), and a dispersion obtained by dispersing colloidal silica as a lubricant in dimethylacetamide (manufactured by Nissan Chemical Industries, Ltd., "Snowtex (registered trademark) DMAC-ST-ZL") were added so that the silica (lubricant) was 0.4% by mass based on the total amount of the polymer solids in the polyamic acid solution and completely dissolved. Then, 23.08 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added in portions as a solid, and then stirred at room temperature for 24 hours. Thereafter, 173.1 parts by mass of DMAc was added for dilution to obtain a polyamic acid solution 3 having a solid content (NV) of 12% by mass and a reduced viscosity of 5.3 dl / g. When Mw was measured in the same manner as in Production Example 2, it was 360,000

[0074] [Production Example 5 (Production of Polyamic Acid Solution 4)] After replacing the nitrogen in the reaction vessel equipped with a nitrogen introduction tube, a reflux tube, and a stirrer with nitrogen, 22.73 parts by mass of 4,4'-diaminobenzanilide (DABAN), 201.1 parts by mass of N,N-dimethylacetamide (DMAc), and a dispersion obtained by dispersing colloidal silica as a lubricant in dimethylacetamide (manufactured by Nissan Chemical Industries, Ltd., "Snowtex (registered trademark) DMAC-ST-ZL") were added so that the silica (lubricant) was 0.4% by mass based on the total amount of the polymer solids in the polyamic acid solution and completely dissolved. Then, 27.32 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added in portions as a solid, and then stirred at room temperature for 24 hours. Thereafter, 173.1 parts by mass of DMAc was added for dilution to obtain a polyamic acid solution 4 having a solid content (NV) of 13% by mass and a reduced viscosity of 2.1 dl / g. When Mw was measured in the same manner as in Production Example 2, it was 28,000

[0075] [Production Example 6 (Production of Polyamic Acid Solution 5)] After replacing the gas in the reaction vessel equipped with a nitrogen inlet tube, a reflux tube, and a stirrer with nitrogen, 22.73 parts by mass of 4,4'-diaminobenzanilide (DABAN), 201.1 parts by mass of N,N-dimethylacetamide (DMAc), and a dispersion obtained by dispersing colloidal silica as a lubricant in dimethylacetamide (Nissan Chemical Industries, Ltd.'s "Snowtex (registered trademark) DMAC-ST-ZL") were added so that the silica (lubricant) was 0.4% by mass based on the total amount of the polymer solids in the polyamic acid solution, and the mixture was completely dissolved. Then, 29.10 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added in portions as a solid, and the mixture was stirred at room temperature for 24 hours. Thereafter, 173.1 parts by mass of DMAc was added for dilution to obtain a polyamic acid solution 5 having a solid content (NV) of 14% by mass and a reduced viscosity of 1.3 dl / g. When Mw was measured in the same manner as in Production Example 2, it was 10,000

[0076] [Production Example 7 (Production of Polyamic Acid Solution 6)] After replacing the gas in the reaction vessel equipped with a nitrogen inlet tube, a reflux tube, and a stirrer with nitrogen, 22.02 parts by mass of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 252.1 parts by mass of N,N-dimethylacetamide (DMAc), and a dispersion obtained by dispersing colloidal silica as a lubricant in dimethylacetamide (Nissan Chemical Industries, Ltd.'s "Snowtex (registered trademark) DMAC-ST-ZL") were added so that the silica (lubricant) was 0.4% by mass based on the total amount of the polymer solids in the polyamic acid solution, and the mixture was completely dissolved. Then, 22.02 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added in portions as a solid, and the mixture was stirred at room temperature for 24 hours. Thereafter, 165.7 parts by mass of DMAc was added for dilution to obtain a polyamic acid solution 6 having a solid content (NV) of 11% by mass and a reduced viscosity of 4.1 dl / g. When Mw was measured in the same manner as in Production Example 2, it was 210,000

[0077] [Production Example 8 (Production of Polyamic Acid Solution 7)] After purging the inside of the reaction vessel equipped with a nitrogen introduction tube, a reflux tube, and a stirrer with nitrogen, 22.0 parts by mass of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 252.1 parts by mass of N,N-dimethylacetamide (DMAc), and a dispersion obtained by dispersing colloidal silica as a lubricant in dimethylacetamide (manufactured by Nissan Chemical Industries, Ltd., "Snowtex (registered trademark) DMAC-ST-ZL") were added so that the silica (lubricant) was 0.4% by mass based on the total polymer solid content in the polyamic acid solution and completely dissolved. Then, 22.0 parts by mass of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was added in portions as a solid, and the mixture was stirred at room temperature for 24 hours. Thereafter, 165.7 parts by mass of DMAc was added for dilution to obtain a polyamic acid solution 7 having a solid content (NV) of 11% by mass and a reduced viscosity of 3.5 dl / g. When Mw was measured in the same manner as in Production Example 2, it was 70,000.

[0078] [Production Example 9 (Production of Polyimide Film F1)] The polyamic acid solution 2 obtained in Production Example 3 was coated on the non-lubricated surface of a polyethylene terephthalate film A4100 (a support manufactured by Toyobo Co., Ltd.) using a comma coater and adjusted so that the final film thickness was 0.3 μm. The polyethylene terephthalate film A04100 was passed through a hot air furnace and wound up, and at this time, it was dried at 100°C for 10 minutes. After winding this up, it was reset on the comma coater side, and then the polyimide solution 1 obtained in Production Example 1 was applied onto the dried product of the polyamic acid solution 2 so that the final film thickness was 25 μm. This was dried at 100°C for 10 minutes. After drying, the self-supporting polyamic acid film was peeled from the support, passed through a pin tenter having a pin sheet with pins arranged thereon, and the film end was inserted into the pins for gripping. The pin sheet interval was adjusted so that the film would not break and no unnecessary slack would occur, and it was conveyed and heated under the conditions of 200°C for 3 minutes, 250°C for 3 minutes, and 300°C for 6 minutes to allow the imidization reaction to proceed. Thereafter, it was cooled to room temperature in 2 minutes, and the portions with poor planarity at both ends of the film were cut off with a slitter and wound up in a roll to obtain 500 m of a polyimide film F1 having a width of 450 mm.

[0079] 〔Production Example 10 (Production of Polyimide Film F2)〕 The same operations as those in the production of the polyimide film F1 in Production Example 9 were carried out, except that the polyamic acid solution 2 obtained in Production Example 3 was changed to the polyamic acid solution 7 obtained in Production Example 8, to obtain a polyimide film F2.

[0080] <Coefficient of Thermal Expansion (CTE) of Thermoset of Polyamic Acid> The polyamic acid solutions 1 to 7 were coated on an alkali-free glass with a bar coater so that the dry thickness became 25 μm, dried in a hot air oven at 120 °C for 1 hour, and then dried at 150 °C for 30 minutes. The laminate of this glass and the polyamic acid was further heated gradually to 350 °C at 5 °C / min and further heated for 10 minutes for thermal imidization to obtain a laminate of a polyimide film and glass. The polyimide film was peeled off from the glass, and the expansion and contraction rates were measured under the following conditions in the coating direction (MD direction) and the width direction (TD direction). The expansion and contraction rate / temperature at 2 °C intervals such as 30 °C to 32 °C and 32 °C to 34 °C were measured, and this measurement was carried out up to 200 °C. The average value of all the measured values was calculated as the CTE. Regarding the polyimide films F1 and F2, the measurements were carried out in the flow direction (MD direction) and the width direction (TD direction). The results are shown in Tables 1 and 2. Equipment name: TMA4000S manufactured by MAC Science Co., Ltd. Sample length: 20 mm Sample width: 2 mm Temperature rise start temperature: 25 °C Temperature rise end temperature: 300 °C Temperature rise rate: 10 °C / min Atmosphere: Argon

[0081] <Total Light Transmittance> The total light transmittance (TT) of the film was measured using a HAZEMETER (NDH5000, manufactured by Nippon Denshoku Industries Co., Ltd.). A D65 lamp was used as the light source. The same measurement was carried out 3 times, and the arithmetic mean value was adopted.

[0082] <Yellow Index (YI)> Using a colorimeter (ZE6000, manufactured by Nippon Denshoku Industries Co., Ltd.) and a C2 light source, the tristimulus values XYZ of the film were measured in accordance with ASTM D1925, and the yellowness index (YI) was calculated using the following formula. The same measurement was performed three times, and the arithmetic mean value was adopted. YI = 100×(1.28X - 1.06Z) / Y

[0083] <Haze> The haze of the film was measured using a HAZEMETER (NDH5000, manufactured by Nippon Denshoku Industries Co., Ltd.). A D65 lamp was used as the light source. The same measurement was performed three times, and the arithmetic mean value was adopted.

[0084] (Example 1) Polyamic acid solution 1 was cast on a square non-alkali glass (Eagle 2000, manufactured by Corning Inc.) with sides of 150 mm and a thickness of 0.7 mm using a bar coater so that the dry thickness was 10 μm, and dried in a hot air oven at 110°C for 1 hour. The laminate of the obtained glass and the dried polyamic acid solution was further heated from room temperature to 330°C at a rate of 5°C / min, and then heated for an additional 10 minutes to imidize, thereby obtaining a laminate of a thermoset of polyamic acid with a thickness of about 10 μm and a non-alkali glass plate.

[0085] (Example 2) A laminate of a thermoset of polyamic acid and a non-alkali glass plate was obtained in the same manner as in Example 1, except that polyamic acid solution 1 was changed to polyamic acid solution 2.

[0086] (Example 3) A laminate of a thermoset of polyamic acid and a non-alkali glass plate was obtained in the same manner as in Example 1, except that polyamic acid solution 1 was changed to polyamic acid solution 6.

[0087] (Example 4) The polyamic acid solution 7 was cast onto a square alkali-free glass (Eagle 2000 manufactured by Corning Inc.) with sides of 150 mm and a thickness of 0.7 mm using a bar coater so that the dry thickness was 10 μm, and dried in a hot air oven at 90 °C for 1 hour. The laminate of the glass and the dried polyamic acid solution thus obtained was further heated to 300 °C at a rate of 5 °C / min and then heated for an additional 10 minutes for imidization to obtain a laminate of a thermoset of polyamic acid with a thickness of about 10 μm and an alkali-free glass plate.

[0088] (Example 5) A laminate of a thermoset of polyamic acid and an alkali-free glass plate was obtained in the same manner as in Example 4, except that a silane coupling agent (KBM-903, manufactured by Shin-Etsu Silicone Co., Ltd.) was applied to the surface of the alkali-free glass plate on which the polyamic acid solution was applied.

[0089] (Example 6) The polyamic acid solution 3 and the polyimide solution 1 were cast onto a square alkali-free glass (Eagle 2000 manufactured by Corning Inc.) with sides of 150 mm and a thickness of 0.7 mm using a tabletop die coater (manufactured by Blue Ocean Technology Co., Ltd.) so that the dry thicknesses were 3 μm and 10 μm, respectively, and dried in a hot air oven at 110 °C for 1 hour. The coating was performed in such a way that the glass plate, the polyamic acid solution 3, and the polyimide solution 1 were laminated in that order. The laminate of the glass and the dried polyamic acid solution thus obtained was further heated to 330 °C at a rate of 5 °C / min and then heated for an additional 10 minutes for imidization to obtain a laminate of a thermoset of polyamic acid with a thickness of about 13 μm and an alkali-free glass plate.

[0090] (Example 7) A laminate of a thermoset of polyamic acid and an alkali-free glass plate was obtained in the same manner as in Example 6, except that the polyamic acid solution 3 was changed to the polyamic acid solution 6.

[0091] (Example 8) The polyamic acid solution 7 and the polyimide solution 1 were cast onto a square alkali-free glass (Eagle 2000 manufactured by Corning Inc.) with sides of 150 mm and a thickness of 0.7 mm using a tabletop die coater (manufactured by Blue Ocean Technology Co., Ltd.) so that the dry thicknesses were 3 μm and 10 μm respectively, and dried in a hot air oven at 90 °C for 1 hour. The coating was carried out such that the glass plate, the polyamic acid solution 3, and the polyimide solution 1 were laminated in this order. The laminate of the glass and the dried product of the polyamic acid solution thus obtained was further heated from room temperature to 300 °C at a rate of 5 °C / min and then heated for an additional 10 min for imidization to obtain a laminate of a thermoset of polyamic acid with a thickness of about 13 μm and an alkali-free glass plate.

[0092] (Example 9) The film F1 obtained in Production Example 9 was used. A silane coupling agent was applied to the glass plate, and the layer of the polyamic acid solution 2 of the film F1 was laminated thereon in contact with the glass plate side and heated to obtain a laminate with the glass. The method of applying the silane coupling agent to the glass substrate was carried out using the apparatus shown in Fig. 1. Fig. 1 is a schematic diagram of an apparatus for applying a silane coupling agent to a glass substrate. A glass substrate 1 (OA11G glass (manufactured by NEG Co., Ltd.) with a thickness of 0.7 mm cut to a size of 100 mm × 100 mm) was used. The glass substrate 1 was used after being subjected to pure water washing, drying, and then dry cleaning by irradiating with a UV / O3 irradiator (SKR1102N-03 manufactured by LAN Technical) for 1 minute. 150 g of 3-aminopropyltrimethoxysilane (silane coupling agent Shin-Etsu Chemical KBM903) was placed in a chemical solution tank with a capacity of 1 L, and the outer hot water bath was heated to 43 °C. Then, the emerging vapor was sent to the chamber together with clean dry air. The gas flow rate was 25 L / min and the substrate temperature was 24 °C. The temperature of the clean dry air was 23 °C and the humidity was 1.2%RH. Since the exhaust was connected to a negative pressure exhaust port, it was confirmed by a differential pressure gauge that the chamber had a negative pressure of about 10 Pa.

[0093] Next, a film F1 (70 mm × 70 mm size) was laminated on the silane coupling agent layer to obtain a laminate. For lamination, a laminator manufactured by MCK was used, and the lamination conditions were: pressure of compressed air: 0.6 MPa, temperature: 22 °C, humidity: 55% RH, lamination speed: 50 mm / sec. This F1 / glass laminate was heated at 110 °C for 10 min to obtain a laminate of a thermoset film F1 of polyamic acid and a glass plate.

[0094] (Example 10) A laminate was obtained in the same manner as in Example 9 except that the film used was changed from F1 to film F2. Note that the layer of polyamic acid solution 7 of film F2 was laminated so as to be in contact with the glass plate side.

[0095] (Comparative Example 1) A laminate of a thermoset of polyamic acid and a non-alkali glass plate was obtained in the same manner as in Example 1 except that polyamic acid solution 1 was changed to polyamic acid solution 4.

[0096] (Comparative Example 2) A laminate of a thermoset of polyamic acid and a non-alkali glass plate was obtained in the same manner as in Example 1 except that polyamic acid solution 1 was changed to polyamic acid solution 5. The obtained cured product of polyamic acid was brittle, and it was difficult to peel it from the glass.

[0097] [Production Example 11 (Production of Polyamic Acid Solution 8)] After purging the inside of a reaction vessel equipped with a nitrogen introduction tube, a reflux tube, and a stirrer with nitrogen, 320 parts by mass of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 1,500 parts by mass of N,N-dimethylacetamide, and a dispersion obtained by dispersing colloidal silica as a lubricant in dimethylacetamide (manufactured by Nissan Chemical Industries, Ltd., "Snowtex (registered trademark) DMAC-ST-ZL") were added so that the silica (lubricant) was 0.4% by mass based on the total amount of the polymer solids in the polyamic acid solution and completely dissolved. Then, 980 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 103 parts by mass of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), and 47 parts by mass of 4,4'-oxydiphthalic acid (ODPA) were added in portions as solids and then stirred at room temperature for 24 hours. Thereafter, 1,717 parts by mass of DMAc was added for dilution to obtain a polyamic acid solution 8 having a solid content (NV) of 15% by mass and a reduced viscosity of 4.8 dl / g. When Mw was measured in the same manner as in Production Example 2, Mw was 480,000.

[0098] [Production Example 12 (Production of Polyamic Acid Solution 9)] An acid anhydride group-containing double-decker type silsesquioxane derivative (AASQ1) represented by the structure of Formula 1 was obtained from Nippon Institute for Materials Science Co., Ltd.

Chemical Formula

[0099] 〔Production Example 13 (Production of Polyamic Acid Solution 10)〕 The amino group-containing double-decker type silsesquioxane derivative (AMSQ1) represented by the structure of Formula 2 was produced by the method described in JP-A-2006-052146.

Chemical formula

[0100] [Production Example 14 (Production of Polyimide Film F3)] The polyamic acid solution 2 obtained in Production Example 3 was coated onto the non-lubricated surface of a polyethylene terephthalate film A4100 (a support manufactured by Toyobo Co., Ltd.) using a comma coater, adjusted so that the final film thickness would be 0.3 μm. The polyethylene terephthalate film A04100 was passed through a hot air furnace, wound up, and dried at 100°C for 10 minutes at this time. After winding this up, it was reset on the comma coater side, and subsequently, the polyamic acid solution 8 obtained in Production Example 11 was applied onto the dried product of the polyamic acid solution 2 so that the final film thickness would be 25 μm. This was dried at 90°C for 15 minutes. After drying, the self-supporting polyamic acid film was peeled from the support, passed through a pin tenter having a pin sheet with pins arranged, and gripped by inserting the film ends into the pins. The pin sheet interval was adjusted so that the film would not break and no unnecessary slack would occur, and it was conveyed, and heated under the conditions of 3 minutes at 200°C, 3 minutes at 250°C, 3 minutes at 300°C, and 3 minutes at 350°C to advance the imidization reaction. Then, it was cooled to room temperature in 2 minutes, the portions with poor planarity at both ends of the film were cut off with a slitter, wound up in a roll shape, and 500 m of a polyimide film F3 with a width of 450 mm was obtained.

[0101] [Production Example 15 (Production of Polyimide Film F4)] The polyamic acid solution 9 obtained in Production Example 12 was coated onto the non-lubricated surface of a polyethylene terephthalate film A4100 (a support manufactured by Toyobo Co., Ltd.) using a comma coater, adjusted so that the final film thickness was 25 μm. The polyethylene terephthalate film A04100 passed through a hot air furnace, was wound up, and was dried at 90°C for 15 minutes at this time. After drying, the self-supporting polyamic acid film was peeled off from the support, passed through a pin tenter having a pin sheet with pins arranged thereon, and gripped by inserting the film ends into the pins. The film was conveyed while adjusting the pin sheet interval so that the film would not break and no unnecessary sagging would occur, and heated under the conditions of 200°C for 3 minutes, 250°C for 3 minutes, 300°C for 3 minutes, and 350°C for 3 minutes to advance the imidization reaction. Thereafter, it was cooled to room temperature in 2 minutes, the portions with poor flatness at both ends of the film were cut off with a slitter, wound up in a roll shape, and 500 m of a polyimide film F4 with a width of 450 mm was obtained.

[0102] [Production Example 16 (Production of Polyimide Film F5)] The polyamic acid solution 10 obtained in Production Example 13 was coated onto the non-lubricated surface of a polyethylene terephthalate film A4100 (a support manufactured by Toyobo Co., Ltd.) using a comma coater, adjusted so that the final film thickness was 25 μm. The polyethylene terephthalate film A04100 passed through a hot air furnace, was wound up, and was dried at 90°C for 15 minutes at this time. After drying, the self-supporting polyamic acid film was peeled off from the support, passed through a pin tenter having a pin sheet with pins arranged thereon, and gripped by inserting the film ends into the pins. The film was conveyed while adjusting the pin sheet interval so that the film would not break and no unnecessary sagging would occur, and heated under the conditions of 250°C for 3 minutes, 300°C for 3 minutes, 350°C for 3 minutes, and 400°C for 3 minutes to advance the imidization reaction. Thereafter, it was cooled to room temperature in 2 minutes, the portions with poor flatness at both ends of the film were cut off with a slitter, wound up in a roll shape, and 500 m of a polyimide film F5 with a width of 450 mm was obtained.

[0103] (Example 11) The polyamic acid solution 8 was cast onto a square alkali-free glass (Eagle 2000 manufactured by Corning Inc.) with sides of 150 mm and a thickness of 0.7 mm using a bar coater so that the dry thickness became 10 μm, and dried in a hot air oven at 110 °C for 1 hour. The laminate of the glass and the dried polyamic acid solution thus obtained was further heated from 5 °C / min to 350 °C gradually, and further heated for 10 minutes for imidization to obtain a laminate of a thermoset of polyamic acid with a thickness of about 10 μm and an alkali-free glass plate.

[0104] (Example 12) A laminate of a thermoset of polyamic acid and an alkali-free glass plate was obtained in the same manner as in Example 11 except that the polyamic acid solution 8 was changed to the polyamic acid solution 9.

[0105] (Example 13) The polyamic acid solution 10 was cast onto a square alkali-free glass (Eagle 2000 manufactured by Corning Inc.) with sides of 150 mm and a thickness of 0.7 mm using a bar coater so that the dry thickness became 10 μm, and dried in a hot air oven at 110 °C for 1 hour. The laminate of the glass and the dried polyamic acid solution thus obtained was further heated from 5 °C / min to 400 °C gradually, and further heated for 10 minutes for imidization to obtain a laminate of a thermoset of polyamic acid with a thickness of about 10 μm and an alkali-free glass plate.

[0106] (Example 14) A laminate of a thermoset of polyamic acid and an alkali-free glass plate was obtained in the same manner as in Example 13 except that a silane coupling agent (KBM-903, manufactured by Shin-Etsu Silicone) was applied to the surface of the alkali-free glass plate where the polyamic acid solution was applied.

[0107] (Example 15) The polyamic acid solution 3 and the polyamic acid solution 8 were cast onto a square alkali-free glass (Eagle 2000 manufactured by Corning Inc.) with sides of 150 mm and a thickness of 0.7 mm using a tabletop die coater (manufactured by Blue Ocean Technology Co., Ltd.) so that the dry thicknesses were 3 μm and 10 μm respectively, and then dried in a hot air oven at 90 °C for 1 hour. The coating was carried out such that the glass plate, the polyamic acid solution 3, and the polyamic acid solution 8 were laminated in this order. The laminate of the glass and the dried polyamic acid solution thus obtained was further heated gradually to 350 °C at 5 °C / min and then heated for an additional 10 minutes for imidization to obtain a laminate of a thermoset of polyamic acid with a thickness of about 13 μm and an alkali-free glass plate.

[0108] (Example 16) A laminate was obtained in the same manner as in Example 9 except that the film used was changed from F1 to film F3. The layer of the polyamic acid solution 3 of film F3 was laminated so as to be in contact with the glass plate side.

[0109] (Example 17) The film F4 obtained in Production Example 15 was used. A silane coupling agent was applied to a glass plate, and the film F4 was laminated thereon and heated to obtain a laminate with glass. The method of applying the silane coupling agent to the glass substrate was carried out using the apparatus shown in Fig. 1. Fig. 1 is a schematic diagram of an apparatus for applying a silane coupling agent to a glass substrate. A glass substrate 1 (OA11G glass (manufactured by NEG Co., Ltd.) with a thickness of 0.7 mm cut into a size of 100 mm × 100 mm) was used. The glass substrate 1 was used after being subjected to pure water washing, drying, and then dry cleaning by irradiating with a UV / O3 irradiator (SKR1102N-03 manufactured by LAN Technical Co., Ltd.) for 1 minute. 150 g of 3-aminopropyltrimethoxysilane (silane coupling agent Shin-Etsu Chemical KBM903) was placed in a chemical solution tank with a capacity of 1 L, and the outer hot water bath was heated to 43 °C. Then, the emerging vapor was sent to the chamber together with clean dry air. The gas flow rate was 25 L / min, and the substrate temperature was 24 °C. The temperature of the clean dry air was 23 °C, and the humidity was 1.2%RH. Since the exhaust was connected to a negative pressure exhaust port, it was confirmed by a differential pressure gauge that the chamber had a negative pressure of about 10 Pa.

[0110] Next, a film F4 (size: 70 mm × 70 mm) was bonded onto the silane coupling agent layer to obtain a laminate. For the bonding, a laminator manufactured by MCK was used, and the bonding conditions were: pressure of compressed air: 0.6 MPa, temperature: 22 °C, humidity: 55%RH, lamination speed: 50 mm / sec. This F4 / glass laminate was heated at 110 °C for 10 min to obtain a laminate of the thermoset film F4 of polyamic acid and the glass plate.

[0111] (Example 18) A laminate was obtained in the same manner as in Example 17 except that the film used was changed from F4 to film F5.

[0112] <Measurement of 90° peel strength> The laminate obtained in the production of the above laminate was heat-treated at 250 °C for 60 minutes in a nitrogen atmosphere. Then, the 90° peel strength between the glass substrate and the polyimide film was measured. The results are shown in Tables 1 and 2. The measurement conditions for the 90° peel strength are as follows. Peel the film from the inorganic substrate at an angle of 90°. Perform the measurement five times and take the average value as the measured value. Measuring device: Autograph AG-IS manufactured by Shimadzu Corporation Measurement temperature: Room temperature (25°C) Peel rate: 100 mm / min Atmosphere: Air Measured sample width: 2.5 cm

[0113]

Table 1

[0114]

Table 2

Explanation of Symbols

[0115] 1 Flow meter 2 Gas inlet 3 Chemical solution tank (silane coupling agent tank) 4 Warm water tank (hot water bath) 5 Heater 6 Treatment chamber (chamber) 7 Substrate 8 Exhaust port

Claims

1. A laminate of an inorganic substrate and a thermoset of polyamic acid, wherein the weight average molecular weight of the polyamic acid is 30,000 or more, the peel strength between the inorganic substrate and the thermoset layer of polyamic acid after heating the laminate at 250 °C is 0.3 N / cm or less, and the thermoset of the polyamic acid contains a structure of the following formula 1 or a structure of the following formula 2. A laminate characterized by this. 【Chemical 1】 【Chemical Formula 2】

2. The laminate according to claim 1, wherein the CTE of the thermoset of the polyamic acid is 50 ppm / K or less.

3. The laminate according to claim 1 or 2, wherein the thermoset of the polyamic acid is polyimide.

4. The laminate according to any one of claims 1 to 3, wherein the thermoset of the polyamic acid is colorless transparent polyimide.

5. The laminate according to any one of claims 1 to 4, characterized by having a silane coupling agent condensation layer between the inorganic substrate and the thermoset layer of polyamic acid.

6. The laminate according to claim 5, wherein the thickness of the silane coupling agent condensation layer is 0.1 nm to 200 nm.

7. The laminate according to any one of claims 1 to 6, wherein the weight average molecular weight of the polyamic acid is 60,000 or more.

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