Laminates of inorganic substrates / polymer films with protective films, stacking of laminates, storage methods of laminates, and transportation methods of laminates.

Abstract

The objective is to provide an inorganic substrate and a polymer film laminate with a protective film that can be easily and individually removed even when stored in an overlapping state for a long period of time. The solution is a first laminate characterized by sequentially comprising an inorganic substrate, a polymer film layer, and a first protective film, wherein the surface roughness Ra of the side of the inorganic substrate opposite to the polymer film layer is 0.02 μm to 1.2 μm.

Description

[Technical Field]

[0001] This invention relates to the form and storage method of a laminate of an inorganic substrate and a polymer thin film layer, and further to an invention of a transportation method. [Previous Technology]

[0002] Polymer films such as polyimide have been considered as substrate materials for manufacturing flexible electronic devices. Since such polymer films, such as polyimide, are manufactured in long, cylindrical rolls, they are generally considered ideal for roll-to-roll production lines in the manufacture of flexible devices. On the other hand, conventional electronic devices such as display devices, sensor arrays, touch screens, and printed wiring boards mostly use rigid substrates such as glass substrates, semiconductor wafers, or glass fiber reinforced epoxy boards, and manufacturing equipment is also constructed based on the use of such rigid substrates.

[0003] Against this background, as a method for manufacturing flexible electronic devices using existing manufacturing equipment, it is known to manufacture flexible electronic devices using the following process: using a rigid inorganic substrate such as a glass substrate as a temporary support, processing is performed with a polymer film attached to the temporary support, and after electronic device processing is performed on the polymer film, the polymer film with the electronic device formed is peeled off from the temporary support (Patent Document 1).

[0004] Furthermore, as a method for manufacturing flexible electronic devices using existing manufacturing equipment, the following method is known: using a rigid substrate such as a glass substrate as a temporary support, coating a polymer solution or a polymer precursor solution onto the temporary support, drying it to form a precursor film, and then causing a chemical reaction to convert the precursor into a polymer film, thereby obtaining a laminate of a temporary support and a polymer film. Similarly, after forming an electronic device on the polymer film, the flexible electronic device is manufactured by peeling it off (Patent Document 2).

[0005] However, in the process of forming desired functional elements on a laminate of a polymer film and an inorganic support, the laminate is often exposed to high temperatures. For example, in the formation of functional elements such as polycrystalline silicon or oxide semiconductors, steps in the temperature range of approximately 200°C to 600°C are necessary. Furthermore, in the fabrication of hydrogenated amorphous silicon films, temperatures of approximately 200 to 300°C are applied to the film. Moreover, in order to heat and dehydrogenate amorphous silicon to become low-temperature polycrystalline silicon, heating to approximately 450°C to 600°C is required. Therefore, the polymer film constituting the laminate requires heat resistance, but the practical problem is that there are limited polymer films that can withstand such high temperatures for practical use, and in most cases, polyimide is chosen.

[0006] That is, in any method, a laminate is formed by stacking a rigid temporary support with a polymer film layer. The polymer film is eventually peeled off to become the substrate of a flexible electronic device. The laminate can be treated as a rigid substrate and can therefore be processed in the same way as a glass substrate for manufacturing devices such as liquid crystal displays, plasma displays, or organic EL displays that use conventional glass substrates.

[0007] [Prior Art Documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent No. 5152104 [Patent Document 2] Japanese Patent No. 5699606 [Summary of the Invention]

[0009] [The problem the invention aims to solve]

[0010] The subject of this invention is the form, storage method, and further, transportation method of the laminate formed by the polymer film and the rigid temporary support described above. Conventionally, rigid inorganic substrates such as glass substrates are stored or transported by stacking multiple sheets. During stacking, to facilitate the removal of the inorganic substrate from the stack after storage or transportation, a cushioning material such as a foamed polymer sheet or paper is inserted between the inorganic substrates. This method can be applied to glass substrates with sufficient surface hardness. However, in the laminate of the inorganic substrate (temporary support substrate) and polymer film operated in this invention, because the surface hardness of the polymer film is insufficient, if the laminate is stacked, the polymer film surface of the laminate rubs against the inorganic substrate surface, resulting in scratches on the soft polymer film surface. Furthermore, even when a cushioning material such as a foamed polymer sheet or paper is inserted, foreign matter can easily cause scratches on the polymer film surface.

[0011] A common method for solving such problems is to protect the surface of a polymer film by means of a protective film. Generally speaking, the protective film is a micro-adhesive film on one side of a relatively inexpensive polymer film such as polyethylene, polypropylene, or polyester, which has a weakly adhesive material coated on it.

[0012] By using this protective film, damage to the polymer film surface can be prevented, maintaining a polymer film surface suitable for forming fine flexible electronic devices. However, the inventors face the following problem: when multiple laminates with protective films attached to the polymer film surface of the laminate are stacked and stored or transported, the protective film surface and the inorganic substrate surface tend to adhere to each other, making it difficult to remove them individually. Although cushioning materials such as foamed polymer sheets or paper can be used in the same way as glass substrates, this involves using additional materials besides the protective film, increasing costs and waste. Therefore, using cushioning materials cannot be considered a better method.

[0013] Furthermore, when a polymer solution or polymer precursor solution is coated onto an inorganic substrate to convert it into a polymer film and manufacture a laminate, the laminate manufacturing step becomes a batch process. However, in subsequent steps, if productivity is considered, it is preferable to form a continuous sheet by bonding the monolithic laminates together. From the perspective of preventing damage to the polymer film surface and improving transportability, by continuously attaching long strips of protective film to the polymer film surface of the laminate as shown in Figure 1, the monolithic laminate can be made into a continuous sheet for operation. In this case, sometimes it is stored and transported in a stacked state with the protective film folded as shown in Figure 2, but at this time, the problem of the protective film surface adhering to the inorganic substrate surface also occurs.

[0014] Furthermore, from the viewpoint of preventing damage to the glass, in the case of using polymer solutions or polymer precursor solutions, and in the case of using pre-thinned polymers, it is possible that the protective film is also attached to the inorganic substrate surface. In this case, the protective film may sometimes be stored and transported in a stacked state with the protective film folded as shown in Figure 3, but in this case, the problem of the protective film surface adhering to the inorganic substrate surface will also occur.

[0015] The problem to be solved by the present invention is to provide a suitable form and method for storing or transporting a laminate made of a polymer film and a rigid temporary support. That is, the present invention provides an inorganic substrate / polymer film laminate with a protective film that can be easily and individually removed even when stored in an overlapping state for a long period of time; provides a stack formed by stacking inorganic substrate / polymer film laminates with protective films; provides a method for storing an inorganic substrate / polymer film laminate using a specific protective film; and provides a method for transporting an inorganic substrate / polymer film laminate. [Means for solving the problem]

[0016] That is, the present invention comprises the following components. [1] A first laminate, characterized in that it sequentially comprises an inorganic substrate, a polymer film layer, and a first protective film, wherein the surface roughness Ra of the side of the inorganic substrate opposite to the side of the polymer film layer is 0.02 μm to 1.2 μm. [2] The first laminate as described in [1], wherein the coefficient of kinetic friction between the side of the first protective film opposite to the side of the polymer film layer and the side of the inorganic substrate opposite to the side of the polymer film layer is in the range of 0.02 to 0.25. [3] A second laminate, characterized in that it sequentially comprises a second protective film, an inorganic substrate, a polymer film layer, and a first protective film, wherein the surface roughness Ra of the side of the second protective film opposite to the side of the inorganic substrate is 0.02 μm to 1.2 μm. [4] The second laminate as described in [3], wherein the coefficient of kinetic friction between the surface of the first protective film opposite to the polymer film layer and the surface of the second protective film opposite to the inorganic substrate is in the range of 0.02 to 0.25. [5] The second laminate as described in [3] or [4], wherein the coefficient of kinetic friction between the surfaces of the second protective film opposite to the inorganic substrate is in the range of 0.02 to 0.25. [6] The laminate as described in any one of [1] to [5], wherein the diameter of the outer circle of the inorganic substrate is 310 mm or more. [7] A laminate stack, characterized in that four or more laminates as described in any one of [1] to [6] are stacked in the same direction in the layer direction. [8] A method for storing a laminate, characterized in that it is stored in the form of a laminate stack as described in [7]. [9] A method for transporting laminates, characterized in that the laminates are transported in a stacked form as described in [7]. [Effects of the Invention]

[0017] When an inorganic substrate and a polymer film are laminated into a continuous sheet using a protective film, if the outer side of the inorganic substrate opposite to the polymer film is smooth when the second protective film is not used, and if the surface of the second protective film is smooth when the second protective film is used, the air layer between the surfaces opposite to the first protective film will gradually be expelled from between the surfaces due to the weight of the laminate, resulting in a vacuum seal. This is why it is difficult to individually remove the laminate during long-term storage. While the size of the laminate is not a major problem when it is small, if it is intended for use in a display manufacturing device, the size of the laminate would be an inorganic substrate of approximately 2m x 3m. If multiple laminates of this size are vacuum-sealed, they are very difficult to peel off, and in the case where the inorganic substrate is glass, breakage of the glass substrate becomes more likely. By constructing the present invention, such problems can be avoided. Even when the laminate and the laminate system containing the protective film are bundled together and stored for a long time, they can be easily taken out individually.

Implementation Method

[0019] [Form for implementing the invention]

[0020] Hereinafter, one embodiment of the present invention (hereinafter referred to as "the embodiment") will be described in detail. However, the present invention is not limited to the following embodiment, and various modifications can be made within its scope.

[0021] <Polyamide> The polyamide system of the present invention can be manufactured by a well-known manufacturing method. That is, a polyamide solution is obtained by polymerizing one or more tetracarboxylic anhydride components and one or more diamine components as raw materials in an organic solvent. The preferred solvent for synthesizing polyamide is an amide-based solvent, such as N,N-dimethylacetamide, N-methyl-2-pyrrolidone, etc., and N,N-dimethylacetamide is particularly preferred. In the reaction apparatus, it is preferable to have a temperature adjustment device for controlling the reaction temperature. The reaction temperature is preferably 0°C to 80°C, more preferably 15°C to 60°C, which is preferable from the perspective of suppressing the hydrolysis of polyamide in the reverse reaction of polymerization and preventing the viscosity of polyamide from easily increasing.

[0022] There are no particular restrictions on the diamines that constitute polyamides; aromatic diamines, aliphatic diamines, and alicyclic diamines commonly used in the synthesis of polyimides can be used. From the viewpoint of heat resistance, aromatic diamines are preferred. Diamines can be used alone or in combination of two or more.

[0023] As a diamine, there is no particular limitation, for example, oxydiphenylamine (bis(4-aminophenyl) ether) and p-phenylenediamine (1,4-phenylenediamine) are examples.

[0024] As the tetracarboxylic acid constituting polyimide, aromatic tetracarboxylic acids (including their anhydrides), aliphatic tetracarboxylic acids (including their anhydrides), and alicyclic tetracarboxylic acids (including their anhydrides) commonly used in the synthesis of polyimide can be used. When these are anhydrides, there may be one or two anhydride structures within the molecule, preferably those with two anhydride structures (dianhydrides). Tetracarboxylic acids can be used alone or in combination of two or more.

[0025] As a tetracarboxylic acid, there is no particular limitation; for example, pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride can be cited.

[0026] The thermosetting product of polyamide is preferably polyimide, but it can also be colorless and transparent polyimide.

[0027] This invention describes a colorless transparent polyimide, an example of a thermosetting polyamide of polyacrylic acid. For the sake of simplicity, it will be referred to as transparent polyimide hereafter. The transparency of the transparent polyimide is preferably 75% or higher of total light transmittance. More preferably, it is 80% or higher, even more preferably 85% or higher, even more preferably 87% or higher, and particularly preferably 88% or higher. There is no particular limitation on the upper limit of the total light transmittance of the aforementioned transparent polyimide, but for use in flexible electronic devices, it is preferably 98% or lower, even more preferably 97% or lower. The colorless transparent polyimide of this invention is preferably a polyimide with a total light transmittance of 75% or higher.

[0028] The aromatic tetracarboxylic acids used to obtain the colorless and highly transparent polyimide of the present invention can be used alone or in combination of two or more. When heat resistance is important, the copolymerization amount of the aromatic tetracarboxylic acids is preferably 50% by mass or more of all tetracarboxylic acids, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and 100% by mass is also acceptable.

[0029] 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-trimethyleneanthracene-2,3,6,7-tetracarboxylic acid, decahydronaphthalene-2,3,6,7-tetracarboxylic acid, and decahydro-1,4:5... 8-Dimethylnaphthalene-2,3,6,7-tetracarboxylic acid, decahydro-1,4-bridged ethylene-5,8-methylenenaphthalene-2,3,6,7-tetracarboxylic acid, norcamphene-2-spiro-α-cyclopentanone-α'-spiro-2”-norcamphene-5,5”,6,6”-tetracarboxylic acid (also known as "norcamphene-2-spiro-2'-cyclopentanone-5'-spiro-2”-norcamphene-5, 5”,6,6”-tetracarboxylic acid), methylnorcampane-2-spiro-α-cyclopentanone-α'-spiro-2”-(methylnorcampane)-5,5”,6,6”-tetracarboxylic acid, norcampane-2-spiro-α-cyclohexanone-α'-spiro-2”-norcampane-5,5”,6,6”-tetracarboxylic acid (also known as "norcampane-2-spiro-2'-cyclohexanone-6'-spiro-2”) -norbornene-5,5”,6,6”-tetracarboxylic acid), methylnorbornene-2-spiro-α-cyclohexanone-α'-spiro-2”-(methylnorbornene)-5,5”,6,6”-tetracarboxylic acid, norbornene-2-spiro-α-cyclopropanone-α'-spiro-2”-norbornene-5,5”,6,6”-tetracarboxylic acid, norbornene-2-spiro-α-cyclobutanone-α'-spiro -2”-norbornen-5,5”,6,6”-tetracarboxylic acid, norbornen-2-spiro-α-cycloheptanone-α'-spiro-2”-norbornen-5,5”,6,6”-tetracarboxylic acid, norbornen-2-spiro-α-cyclooctanone-α'-spiro-2”-norbornen-5,5”,6,6”-tetracarboxylic acid, norbornen-2-spiro-α-cyclononone-α'-spiro-2”-norbornen Camphorane-5,5”,6,6”-tetracarboxylic acid, norcamphorane-2-spiro-α-cyclodecanoone-α'-spiro-2”-norcamphorane-5,5”,6,6”-tetracarboxylic acid, norcamphorane-2-spiro-α-cycloundecanoone-α'-spiro-2”-norcamphorane-5,5”,6,6”-tetracarboxylic acid, norcamphorane-2-spiro-α-cyclododecanone-α'-spiro-2”-norcamphorane- 5,5”,6,6”-Tetracarboxylic acid, norcamphene-2-spiro-α-cyclotridecylone-α'-spiro-2”-norcamphene-5,5”,6,6”-Tetracarboxylic acid, norcamphene-2-spiro-α-cyclotetradecylone-α'-spiro-2”-norcamphene-5,5”,6,6”-Tetracarboxylic acid, norcamphene-2-spiro-α-cyclopentadecanone-α'-spiro-2”-norcamphene-5,Tetracarboxylic acids such as 5”,6,6”-tetracarboxylic acid, norcamphene-2-spiro-α-(methylcyclopentanone)-α'-spiro-2”-norcamphene-5,5”,6,6”-tetracarboxylic acid, norcamphene-2-spiro-α-(methylcyclohexanone)-α'-spiro-2”-norcamphene-5,5”,6,6”-tetracarboxylic acid, and their anhydrides. Among these, dianhydrides having two anhydride structures are preferred, especially 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclohexanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, more preferably 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, and particularly preferably 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride. Furthermore, these can be used alone or in combination of two or more. When transparency is important, the copolymerization amount of the alicyclic tetracarboxylic acid is preferably 50% by mass or more of all tetracarboxylic acids, more preferably 60% by mass or more, especially preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and 100% by mass is also acceptable.

[0030] Examples of tricarboxylic acids include: aromatic tricarboxylic acids such as trimellitic acid, 1,2,5-naphthalenetricarboxylic acid, diphenyl ether-3,3',4'-tricarboxylic acid, and diphenyl tannin-3,3',4'-tricarboxylic acid; hydrides of the above aromatic tricarboxylic acids such as hexahydrotriphenylcarboxylic acid; alkyldiol bis(p-phenylene) esters such as ethylene glycol bis(p-phenylene) ester, propylene glycol bis(p-phenylene) ester, 1,4-butanediol bis(p-phenylene) ester, and polyethylene glycol bis(p-phenylene) ester; and anhydrides and esters thereof. Among these, an anhydride having one anhydride structure is preferred, and trimellitic anhydride and hexahydrotriphenylcarboxylic anhydride are particularly preferred. Furthermore, these can be used alone or in combination in multiples.

[0031] Examples of dicarboxylic acids include: aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, and 4,4'-oxydiphenylcarboxylic acid; or hydrides of the above aromatic dicarboxylic acids such as 1,6-cyclohexanedicarboxylic acid; oxalic acid; succinic acid; glutaric acid; adipic acid; pimelic acid; octanoic acid; azelaic acid; sebacic acid; undecanoic acid; dodecanoic acid; 2-methylsuccinic acid; and their acetic acid chlorides or esters. Among these, aromatic dicarboxylic acids and their hydrides are preferred, and terephthalic acid, 1,6-cyclohexanedicarboxylic acid, and 4,4'-oxydiphenylcarboxylic acid are particularly preferred. Furthermore, dicarboxylic acids can be used alone or in combination in multiples.

[0032] There are no particular limitations on the diamines or isocyanates used to obtain the colorless and highly transparent polyimide of the present invention. Aromatic diamines, aliphatic diamines, alicyclic diamines, aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates commonly used in polyimide synthesis, polyamide-imide synthesis, and polyimide 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, if an aromatic diamine with a benzoazole structure is used, it exhibits high heat resistance, as well as high elastic modulus, low thermal shrinkage, and low coefficient of linear expansion. Diamines and isocyanates can be used alone or in combination of two or more.

[0033] As aromatic diamines, examples 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'-di-trifluoromethyl-4,4'-diaminobiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]one, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfide, 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)benzylamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2'-trifluoromethyl-4,4'-diaminodiphenyl ether, 3 3,3'-Diaminodiphenyl sulfide, 3,4'-Diaminodiphenyl sulfide, 4,4'-Diaminodiphenyl sulfide, 3,3'-Diaminodiphenyl sulfide, 3,4'-Diaminodiphenyl sulfide, 4,4'-Diaminodiphenyl sulfide, 3,3'-Diaminodiphenyl sulfide, 3,4'-Diaminodiphenyl sulfide, 4,4'-Diaminodiphenyl sulfide, 3,3 '-Diaminodiphenyl ketone, 3,4'-Diaminodiphenyl ketone, 4,4'-Diaminodiphenyl ketone, 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]propane [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]one, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, 1,3-bis[4-(4-aminophenoxy)benzyl]benzene, 1,3-bis[4-(3-aminophenoxy)phenyl]benzene [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]pyrene, 4,4'-bis[ 3-(4-aminophenoxy)benzyl]diphenyl ether, 4,4'-bis[3-(3-aminophenoxy)benzyl]diphenyl ether, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenyl ketone, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenyl ketone, bis[4-{4-(4-aminophenoxy)phenoxy}phenyl] ketone, 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'-diphenoxydiphenyl ketone, 4,4'-diamino-5,5'-diphenoxydiphenyl ketone, 3,4'-diamino-4,5'-diphenoxydiphenyl ketone, 3,3'-diamino-4-phenoxydiphenyl ketone, 4,4'-diamino-5-phenoxydiphenyl ketone, 3,4'-diamino-4-phenoxydiphenyl ketone, 3,4'-diamino-5'-phenoxydiphenyl ketone, 3,3'-Diamino-4,4'-Diphenyloxydiphenyl ketone, 4,4'-Diamino-5,5'-Diphenyloxydiphenyl ketone, 3,4'-Diamino-4,5'-Diphenyloxydiphenyl ketone, 3,3'-Diamino-4-Biphenyloxydiphenyl ketone, 4,4'-Diamino-5-Biphenyloxydiphenyl ketone, 3,4'-Diamino-4-Biphenyloxydiphenyl ketone 3,4'-Diamino-5'-biphenoxydiphenyl ketone, 1,3-bis(3-amino-4-phenoxybenzyl)benzene, 1,4-bis(3-amino-4-phenoxybenzyl)benzene, 1,3-bis(4-amino-5-phenoxybenzyl)benzene, 1,4-bis(4-amino-5-phenoxybenzyl)benzene, 1,3-bis(3-amino-4-biphenoxy)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-enanthraquinone-9,9-diyl] Bisaniline (also known as "9,9-bis(4-aminophenyl)fusin"), spiro(xanthan-9,9'-fusin)-2,6-diylbis(oxycarbonyl)]bisaniline, 4,4'-[spiro(xanthan-9,9'-fusin)-2,6-diylbis(oxycarbonyl)]bisaniline, 4,4'-[spiro(xanthan-9,9'-fusin)-3,6-diylbis(oxycarbonyl)]bisaniline, etc. Furthermore, some or all of the hydrogen atoms on the aromatic ring of the above-mentioned aromatic diamines may be replaced by halogen atoms, alkyl or alkoxy groups having 1 to 3 carbon atoms, or cyano groups; furthermore, some or all of the hydrogen atoms on the aforementioned alkyl or alkoxy groups having 1 to 3 carbon atoms may also be replaced by halogen atoms. Furthermore, the aforementioned aromatic diamines having a benzoazole structure are not particularly limited, and examples include: 5-amino-2-(p-aminophenyl)benzoazole, 6-amino-2-(p-aminophenyl)benzoazole, 5-amino-2-(m-aminophenyl)benzoazole, 6-amino-2-(m-aminophenyl)benzoazole, 2,2'-p-phenylbis(5-aminobenzoazole), 2,2'-p-phenylbis(6-aminobenzoazole), 1-(5-aminobenzozazoleone)-4-(6-aminobenzozazoleone)benzene, and 2,6-(4,4'-diaminodiphenyl) Benzo[1,2-d:5,4-d']bisazole, 2,6-(4,4'-diaminodiphenyl)benzo[1,2-d:4,5-d']bisazole, 2,6-(3,4'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisazole, 2,6-(3,4'-diaminodiphenyl)benzo[1,2-d:4,5-d']bisazole, 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisazole, 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:4,[5-d']biazole, etc. Among these, 2,2'-di-trifluoromethyl-4,4'-diaminobiphenyl, 4-amino-N-(4-aminophenyl)benzylamine, 4,4'-diaminodiphenylamine, and 3,3'-diaminodiphenyl ketone are particularly preferred. Furthermore, aromatic diamines can be used alone or in combination.

[0034] 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-dibutylcyclohexane, 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 even more preferred. Furthermore, alicyclic diamines can be used alone or in combination.

[0035] 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. Dimethylmethane-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, diphenyl ketone-4, 4'-Diisocyanate, diphenyl-4,4'-diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, m-phenylenedimethyl diisocyanate, terephthalic 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 phenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, and 3,3'-diethoxybiphenyl-4,4'-diisocyanate, and hydrogenated diisocyanates of any of these (e.g., isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate), etc. Among these, considering low hygroscopicity, dimensional stability, price, and polymerizability, diphenylmethane-4,4'-diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate or naphthalene-2,6-diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and 1,4-cyclohexane diisocyanate are preferred. Furthermore, diisocyanates can be used alone or in combination.

[0036] <Polymer Film Layer> The polymer film layer of the present invention is a layer comprising a polymer film, which is formed by heating a polymer solution to evaporate the solvent, or by heating a polymer precursor solution to evaporate the solvent and then hardening it. Examples of polymer solutions include soluble polyimide, and examples of polymer precursor solutions include polyamide solutions. The polymer film layer can be a single layer or a multilayer (laminated) structure of two or more layers. When the polymer film layer is multilayered, each polymer film layer can have the same composition or different compositions. When the polymer film layer is a single layer, the physical properties of the polymer film layer (melting point, glass transition temperature, yellowness index, total light transmittance, haze, CTE, etc.) refer to the values ​​of the entire polymer film layer. When the polymer film layer has a multilayer structure, the physical properties of the polymer film layer also refer to the values ​​of the entire polymer film layer.

[0037] The average coefficient of linear expansion (CTE) of the polymer film layer 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. Furthermore, it is preferably -5 ppm / K or more, even more preferably -3 ppm / K or more, and even more preferably 1 ppm / K or more. If the CTE is within the aforementioned range, the difference between the coefficient of linear expansion and that of a typical support (inorganic substrate) can be kept small, and even when supplied to a heated process, the polymer film layer can be prevented from peeling off from the inorganic substrate or warping together with the support. Here, CTE refers to the factor of reversible expansion and contraction with respect to temperature. Furthermore, the aforementioned CTE of the polymer film layer 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 polymer solution or polymer precursor solution. The method for determining the CTE of the aforementioned polymer thin film layer was performed using the method described in the examples.

[0038] The aforementioned polymer film layer is preferably a polyimide film, but may also be a transparent polyimide film. When the aforementioned polymer film layer is a transparent polyimide film (hereinafter also referred to as a transparent polymer film layer), its yellowness index (hereinafter also referred to as "yellowness index" or "YI") is preferably 10 or less, more preferably 7 or less, even more preferably 5 or less, and even more preferably 3 or less. There is no particular limitation on the lower limit of the yellowness index of the aforementioned 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.

[0039] The transparent polymer film layer of the present invention preferably has a light transmittance of 70% or more at a wavelength of 400 nm, more preferably 72% or more, particularly preferably 75% or more, and even more preferably 80% or more. There is no particular limitation on the upper limit of the aforementioned transparent polymer film layer's light transmittance at a wavelength of 400 nm, but for use as a flexible electronic device, it is preferably 99% or less, more preferably 98% or less, and even more preferably 97% or less.

[0040] The haze of the transparent polymer film layer in this invention is preferably below 1.0, more preferably below 0.8, even more preferably below 0.5, and even more preferably below 0.3. There is no particular limitation on the lower limit, but in industrial applications, anything above 0.01 is acceptable, and anything above 0.05 is also fine.

[0041] The preferred melting point of the polymer film layer is 250°C or higher, more preferably 300°C or higher, and even more preferably 400°C or higher. Furthermore, the preferred glass transition temperature is 200°C or higher, more preferably 320°C or higher, and even more preferably 380°C or higher. In this specification, the melting point and glass transition temperature are determined by differential thermal analysis (DSC). Moreover, when the melting point exceeds 500°C, it can be determined whether the melting point has been reached by visually observing the thermal deformation behavior when heated to that temperature.

[0042] The thickness of the polymer film layer in this invention is preferably 5 μm or more, more preferably 8 μm or more, particularly preferably 15 μm or more, and even more preferably 20 μm or more. There is no particular upper limit to the aforementioned thickness of the polymer film layer, but for use as a flexible electronic device, it is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 90 μm or less. If it is too thin, the processing after device formation will become difficult; if it is too thick, the flexibility will be compromised.

[0043] The aforementioned thickness non-uniformity of the polymer film layer 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 non-uniformity exceeds 20%, it tends to become difficult to apply to narrow portions. Furthermore, the thickness non-uniformity of the polymer film layer can be addressed, for example, by intentionally extracting approximately 10 points of the polymer film layer after peeling it from the inorganic substrate, measuring the thickness of the polymer film layer using a contact thickness gauge, and calculating it according to the following formula: Thickness non-uniformity (%) of the thermosetting polyamide = 100 × (maximum thickness - minimum thickness) ÷ average thickness

[0044] The polymer film layer may also contain a reaction catalyst (aceimide catalyst), inorganic microparticles, etc., as needed. It is preferable that the aforementioned reaction catalyst, inorganic microparticles, etc., are added in advance to the aforementioned polymer solution or polymer precursor solution as needed.

[0045] As a propylene imidizing catalyst, a tertiary amine is preferred. As a tertiary amine, a heterocyclic tertiary amine is more preferred. Preferred examples of heterocyclic tertiary amines include pyridine, 2,5-diethylpyridine, methylpyridine, quinoline, and isoquinoline. The amount of propylene imidizing agent used is preferably 0.01 to 2.00 equivalents, and particularly preferably 0.02 to 1.20 equivalents, for the reaction site of polyamide (polyimide precursor). If the amount of propylene imidizing catalyst is less than 0.01 equivalents, the catalytic effect cannot be sufficiently obtained, which is undesirable. If the amount is more than 2.00 equivalents, the proportion of catalyst that does not participate in the reaction increases, which is costly.

[0046] Examples of inorganic microparticles include microparticle-shaped inorganic oxide powders such as silica (silica) powder and alumina powder, and microparticle-shaped inorganic salt powders such as calcium carbonate powder and calcium phosphate powder. In the field of this invention, since coarse particles of these inorganic microparticles may become the cause of defects in subsequent steps, these inorganic microparticles are preferably uniformly dispersed.

[0047] <Inorganic substrate> As the aforementioned inorganic substrate, it can be any plate-shaped material that can be used as a substrate made of inorganic materials. Examples include: those mainly composed of glass plates, ceramic plates, semiconductor wafers, metals, etc.; those formed by layering such glass plates, ceramic plates, semiconductor wafers, and metals as a composite; those formed by dispersing such materials; and those containing such fibers.

[0048] The aforementioned glass plate includes quartz glass, high silicate glass (96% silica), soda-lime glass, lead glass, aluminoborosilicate glass, borosilicate glass (Pyrex (registered trademark)), borosilicate glass (alkali-free), borosilicate glass (micro-sheets), aluminosilicate glass, etc. Among these, it is ideal to have a coefficient of linear expansion of 5ppm / K or less. If it is a commercially available product, it is ideal to use liquid crystal glass such as "Corning (registered trademark) 7059" or "Corning (registered trademark) 1737", "EAGLE" manufactured by CORNING Co., Ltd., "AN100" manufactured by Asahi Glass Co., Ltd., "OA10" and "OA11" manufactured by Nippon Electric Glass Co., Ltd., and "AF32" manufactured by SCHOTT Co., Ltd.

[0049] The aforementioned semiconductor wafer is not particularly limited, and examples 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, GaInNAs, LT wafers, LN wafers, ZnO (zinc oxide), CdTe (cadmium telluride), and ZnSe (zinc selenide). Among these, silicon wafers are more suitable, and mirror-polished silicon wafers with a size of 8 inches or larger are particularly preferred.

[0050] The aforementioned metals include single-element metals such as W, Mo, Pt, Fe, Ni, and Au, or alloys such as Inconel, Monel, Ni-chromium-titanium, carbon copper, Fe-Ni invar alloys, and super-invar alloys. Multilayer metal plates formed by adding other metal layers or ceramic layers to these metals are also included. In this case, if the coefficient of linear expansion (CTE) of the entire composite layer is low, Cu, Al, etc., can also be used in the main metal layer. There are no limitations on the metal used as the additional metal layer, as long as it has strong adhesion to the polymer film, does not diffuse, and has good chemical resistance or heat resistance; however, Cr, Ni, TiN, and Mo-containing Cu are suitable examples.

[0051] The ceramic plate in this invention comprises a base ceramic of Al2O3, Mullite, AlN, SiC, crystallized glass, Cordierite, Spodumene, Pb-BSG+CaZrO3+Al2O3, crystallized glass+Al2O3, crystallized Ca-BSG, BSG+quartz, BSG+Al2O3, Pb-BSG+Al2O3, glass-ceramic, and zerodur materials.

[0052] The thickness of the aforementioned inorganic substrate is not particularly limited, but from an operability point of view, a thickness of 10 mm or less is preferred, 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 0.07 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 becomes difficult to handle. Conversely, if it is too thick, it becomes heavy and becomes difficult to handle.

[0053] Surface treatment can also be performed to improve the wettability and adhesion of inorganic substrates. As the surface treatment agent 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 using silane coupling agents.

[0054] <Silane Coupling Agent (SCA)> In the laminate, it is preferable to have a silane coupling agent layer (also called a silane coupling agent condensation layer) between the polymer film layer and the inorganic substrate. In this invention, the silane coupling agent refers to a compound containing more than 10% by mass of Si (silicon). By using the silane coupling agent layer, the intermediate layer between the thermosetting polyacrylic acid layer and the inorganic substrate can be thinned, resulting in less degassing during heating, and making it less prone to dissolution even in wet processes. Even if dissolution occurs, it will remain in trace amounts. The silane coupling agent is preferably one that contains more silicon oxide to improve heat resistance, and is particularly preferably one that has heat resistance at around 400°C. The thickness of the silane coupling agent layer is preferably 200 nm or less (0.2 μm or less). For use in flexible electronic devices, a wavelength of 100 nm or less (0.1 μm or less) is preferred, more ideally 50 nm or less, and especially ideally 10 nm. In manufacturing, it is typically around 0.10 μm or less. Furthermore, in processes where minimal silane coupling agent is desired, wavelengths below 5 nm can also be used. If the wavelength is less than 0.1 nm, there is a risk of reduced peel strength or the appearance of partially unattached areas; therefore, a wavelength of 0.1 nm or more is preferred, and more ideally 0.5 nm or more.

[0055] The silane coupling agent in this invention is not particularly limited, but it is preferably one that has an amino group or an epoxy group. When heat resistance is required in the process, it is ideal to use an aromatic linker between Si and the amino group, etc.

[0056] As a silane coupling agent, there is no particular limitation, but it is preferred to include a coupling agent having an amino group. Specific 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-dimethyl-butylene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, aminophenyltrimethoxysilane, aminophenylethyltrimethoxysilane, and aminophenylaminomethylphenylethyltrimethoxysilane.

[0057] <Protective Film> The first and / or second protective films are not particularly limited. Besides PET film, PEN film, polyethylene film, polypropylene film, nylon film, etc., heat-resistant super engineering plastic films such as PPS film, PEEK film, aromatic polyamide film, polyimide film, and polyimide-indole film can also be used. Among these, PET film is preferred. It is acceptable for the first and second protective films to be the same or different. Industrially, it is preferable that both the first and second protective films are the same, and more preferably, both are PET films.

[0058] Preferably, the protective film has an adhesive layer on the surface in contact with the polymer film layer and / or the inorganic substrate. Because the protective film has an adhesive layer, it exhibits self-adhesion. There are no particular limitations on the adhesive layer; for example, urethane-based, polysiloxane-based, or acrylic-based adhesive layers can be used. The adhesive layer can be prepared by coating an adhesive dissolved in a solvent and then drying it.

[0059] <Laminated Body> The first laminated body of the present invention sequentially comprises an inorganic substrate, a polymer film layer, and a first protective film, wherein the surface roughness Ra of the side of the inorganic substrate opposite to the side of the polymer film layer is 0.02 μm to 1.2 μm. That is, as a laminated body, it has at least three layers: "inorganic substrate / polymer film layer / first protective film". Furthermore, the second laminated body sequentially comprises a second protective film, an inorganic substrate, a polymer film layer, and a first protective film, wherein the surface roughness Ra of the side of the second protective film opposite to the side of the inorganic substrate is 0.02 μm to 1.2 μm. That is, as a laminated body, it has at least four layers: "second protective film / inorganic substrate / polymer film layer / first protective film". Furthermore, the aforementioned silane coupling agent or other layers may also be included between each layer. Furthermore, other layers can be deposited on the side opposite to the polymer film layer of the first protective film without any problem, and other layers can also be deposited on the side opposite to the inorganic substrate of the second protective film without any problem. In this invention, the first laminate and the second laminate are also referred to simply as a laminate. Also, the first protective film and the second protective film are also referred to simply as a protective film.

[0060] <Method for manufacturing a laminate> The laminate system of an inorganic substrate and a polymer thin film layer can be manufactured by casting the aforementioned polymer solution or polymer precursor solution onto an inorganic substrate and then heating it.

[0061] Well-known methods can be used as casting methods for polymer solutions or polymer precursor solutions. Examples of well-known casting methods include gravure coating, spin coating, screen coating, dip coating, rod coating, knife coating, roller coating, and die coating.

[0062] When the polymer precursor solution is a polyacrylic acid solution, the aforementioned polymerization solution can be used directly as the polyacrylic acid solution, but the solvent can be removed or added as needed. In addition to N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone, other solvents that can be used in polyacrylic acid solutions include, for example, dimethyl sulfoxide, hexamethylphospholide, acetonitrile, acetone, and tetrahydrofuran. Furthermore, xylene, toluene, benzene, diethylene glycol ethyl ether, diethylene glycol dimethyl ether, 1,2-bis-(2-methoxyethoxy)ethane bis(2-methoxyethyl) ether, butylceroxose, butylceroxose acetate, propylene glycol methyl ether, and propylene glycol methyl ether acetate can be used as auxiliary solvents without harm.

[0063] The polyamide of the present invention is preferably thermoiminated (thermally cured) at a temperature of 300°C to 450°C. That is, the polyimide of the present invention is preferably thermoiminated (thermally cured) at a temperature of 300 to 450°C.

[0064] Thermal propylene imidization is a method of carrying out the propylene imidization reaction solely by heating without the action of dehydrating ring-closing agents, etc. The heating temperature and heating time can be appropriately determined, for example, as follows: First, to allow the solvent to evaporate, heat at a temperature of 90–200°C for 3–120 minutes. This can be carried out in an air environment, under reduced pressure, or inert gas such as nitrogen. Furthermore, well-known devices such as hot air ovens, infrared ovens, vacuum ovens, and heating plates can be used as heating devices. Second, to further carry out propylene imidization, heat at a temperature of 200–450°C for 3–240 minutes. The heating conditions are preferably a gradual increase in temperature from a low temperature. Furthermore, the maximum temperature is preferably in the range of 300–450°C. If the maximum temperature is below 300°C, thermal propylene imidization becomes difficult to carry out, and the mechanical properties of the resulting polyimide film deteriorate. If the maximum temperature exceeds 450°C, thermal degradation of the polyimide will occur, resulting in deteriorated properties and making it unsuitable. Furthermore, depending on the type or thickness of the polyimide, the type or surface condition of the inorganic substrate, and the heating conditions and methods, the film may spontaneously peel off from the inorganic substrate during heat treatment. If spontaneous peeling occurs, it becomes difficult to obtain a laminate with excellent properties, making it unsuitable. Generally, since the thicker the film, the easier it is for spontaneous peeling to occur, it is preferable to adjust the aforementioned conditions according to the thickness. Additionally, to suppress spontaneous peeling, the casting of the polyimide solution and the thermal imidization process can be performed in multiple stages.

[0065] The solvent content in the polyimide is preferably less than 1% by mass, more preferably less than 0.5% by mass, and even more preferably less than 0.1% by mass. The lower the solvent content, the better, so there is no particular limit to the lower limit, but industrially it is acceptable to be 0.01% by mass or more, and 0.05% by mass or more is also acceptable.

[0066] In this invention, the polyamide solution can be used to coat an inorganic substrate by sequentially or simultaneously applying multiple layers of different polyamide solutions. Specifically, the different polyamide solutions refer to polyamide solutions with different compositions, different amide imidization rates, and different types and amounts of added inorganic particles or additives. In addition to the polyamide solution directly contacting the inorganic substrate, the polyamide solution can also be a polyamide solution that has undergone thermal amide imidization.

[0067] Coating of inorganic substrates with multiple polyamide solutions can be performed, for example, using a two-layer die coater. By using a multilayer die coater and coating sequentially, a laminate containing an inorganic substrate and a polymer film layer (polyimide film) with two or more multilayer structures can be obtained.

[0068] In this invention, the polyamide solution can be applied to an inorganic substrate by heating it at 100-200°C for 3-120 minutes after the first layer is applied to the inorganic substrate to evaporate the solvent, and then applying the second layer of polyamide solution from there.

[0069] The inorganic substrate and polyimide film laminate in this invention can also be formed by coating the inorganic substrate with a polyamide solution, bonding the polyimide film before heating, and then heating it to finally form an inorganic substrate and polyimide laminate.

[0070] In order to obtain the inorganic substrate and polyimide film laminate of the present invention, a polyimide solution pre-coated with a single layer or multiple layers on another support can be heated to form a self-supporting film, which is then bonded to the inorganic substrate and heated to obtain the laminate.

[0071] The inorganic substrate and polyimide film laminate of the present invention can also be obtained by bonding a pre-prepared single-layer or multi-layer thermosetting polyimide film to the inorganic substrate. The single-layer or multi-layer polyimide film can be obtained by coating a polyimide solution onto a support such as a metal strip or resin film, drying it to form a self-supporting film, and then performing thermoimidization. The polyimide solution can be applied to the support in multiple layers simultaneously, or a first layer can be applied, dried, and then a polyimide solution can be applied on top, dried, and then thermoimidized. When three or more layers of polyimide solution are laminated, the coating and heating processes can be repeated simultaneously or sequentially to obtain a multilayer film.

[0072] The laminate of the present invention can also be manufactured by the following process, for example. At least one side of an inorganic substrate is pretreated with a silane coupling agent, and the silane-coupling agent-treated side is laminated with a thin-film polyimide. The laminate is obtained by applying pressure to both. Alternatively, at least one side of a thin-film polyimide is pretreated with a silane coupling agent, and the silane-coupling agent-treated side is laminated with an inorganic substrate. The laminate is obtained by applying pressure to both. As a method of applying pressure, atmospheric pressure or lamination or vacuum pressure or lamination can be cited. In order to obtain a comprehensive and stable peel strength, atmospheric lamination is ideal for large-sized laminates (e.g., exceeding 200 mm). In contrast, for small-sized laminates of about 200 mm or less, vacuum pressure is preferred. The vacuum level achieved by a typical oil rotary pump is sufficient, ideally below 10 Torr. The preferred pressure is 1 MPa to 20 MPa, more preferably 3 MPa to 10 MPa. High pressure may damage the substrate, while low pressure may result in gaps in the seal. The preferred temperature is 90°C to 300°C, more preferably 100°C to 250°C. High temperatures may damage the polyimide, while low temperatures may weaken the seal.

[0073] The shape of the laminate is not particularly limited; it can be square or rectangular. A rectangle is preferred, with the longest side preferably being 300 mm or more, more preferably 500 mm or more, and even more preferably 1000 mm or more. There is no particular upper limit, but for industrial applications, 20,000 mm or less is sufficient, and 10,000 mm or less is also acceptable. Furthermore, the diameter of the outer circle of the inorganic substrate is preferably 310 mm or more. From the perspective that even large laminates can be bundled, stored, or transported in a stacked manner, the laminate of the present invention is preferably 350 mm or more, and even more preferably 400 mm or more. Furthermore, for industrial applications, 30,000 mm or less is sufficient, and 20,000 mm or less is also acceptable.

[0074] <Adhesive> Preferably, there is no adhesive layer between the inorganic substrate and the polymer film layer of the present invention. Here, the adhesive layer referred to in the present invention means that the Si (silicon) content is less than 10% (less than 10% by mass). Furthermore, "substantially not used" (not present) means that the thickness of the adhesive layer between the inorganic substrate and the polymer film layer 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.

[0075] In this invention, after fabricating the laminate of the inorganic substrate and the polymer film layer, a first protective film is attached to the surface of the polymer film layer. The first protective film can be made independent according to the fact that each inorganic substrate / polymer film layer laminate is cut apart, or the laminate can be made continuous in a continuous sheet form by means of the first protective film.

[0076] In this invention, after manufacturing the laminate of the inorganic substrate and the polymer film layer, a second protective film can also be attached to the side of the inorganic substrate opposite to the polymer film layer. The second protective film can be independent as each inorganic substrate / polymer film layer laminate is cut apart, or the laminate can be made continuous in a continuous sheet form by means of the second protective film.

[0077] That is, when the first protective film and the second protective film are used simultaneously in this invention, the following three configurations are considered. (1) Both the first protective film and the second protective film are cut according to the stack of each inorganic substrate / polymer film layer. (2) The stack of inorganic substrate / polymer film layers is made into a continuous sheet by means of the first protective film, and the second protective film is cut according to the stack of each inorganic substrate / polymer film layer. (3) The stack of inorganic substrate / polymer film layers is made into a continuous sheet by means of the second protective film, and the first protective film is cut according to the stack of each inorganic substrate / polymer film layer.

[0078] The continuous sheet structure mentioned here refers to the state in which two or more inorganic substrate / polymer film layers are connected by any one of the continuous protective films.

[0079] The timing of bonding the first protective film and the second protective film to the inorganic substrate / polymer film layer is as shown in Figure 1(b), which can be simultaneous or sequential. There is no particular restriction on the bonding order, but from the point of view of protecting the surface of the polymer film layer, it is preferable to bond the first protective film first.

[0080] When a pre-cured thermosetting polyamide (specifically, a polyimide film, etc.) is used as a polymer film layer in a laminate, the first protective film and / or the second protective film can be pre-attached to the thermosetting polyamide. In this case, a laminate can be made using films pre-cut into single sheets, or a long strip of film can be rolled out and attached to an inorganic substrate. By cutting the film before and after attachment, a single-sheet laminate can be formed. Even if the laminate is temporarily a single sheet, it can be made into a continuous sheet by attaching the first and / or second protective films.

[0081] The surface roughness Ra of the surface opposite to the inorganic substrate of the second protective film substrate in the second laminate of the present invention is preferably 0.02 μm or more, more preferably 0.025 μm or more, and even more preferably 0.03 μm or more. The upper limit is preferably 1.2 μm or less, more preferably 0.6 μm or less, and even more preferably 0.3 μm or less. As a method for controlling the surface roughness of the protective film substrate within a specific range, an example is a method of controlling the surface roughness by adding inorganic particles to the raw material resin during the manufacture of the protective film substrate. As inorganic particles, only a specific amount of well-known inorganic particles such as silica, alumina, calcium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, calcium phosphate, magnesium phosphate, barium sulfate, talc, and kaolin are required. The amount added varies depending on the elongation ratio during substrate film production, the final substrate film thickness, and the particle size distribution of the added inorganic particles. Generally, it is 500 ppm or more by mass relative to the mass of the substrate film resin, preferably 1000 ppm or more, more preferably 2000 ppm or more, with an upper limit of 10% by mass or less, preferably 3% by mass or less, and more preferably 10000 ppm or less. As a method for controlling the surface roughness of the protective film substrate within a specific range, an example is grinding or milling the surface of the film substrate to achieve a specific surface roughness. Furthermore, as a method for controlling the surface roughness of the protective film substrate within a specific range, an example is casting the film raw material onto a support substrate pre-made to achieve a specific surface roughness to obtain the protective film substrate. Additionally, a method of controlling the surface roughness of the protective film substrate by pressing with an embossing roller or the like, which has been processed into a specific surface shape.

[0082] In the laminate of the present invention, the surface roughness of the side of the first protective film opposite to the polymer film layer is preferably 0.005 μm or more, and more preferably 0.01 μm or more. If the surface roughness of the side of the first protective film opposite to the polymer film layer is 0.005 μm or more, then when the surface roughness of the side of the inorganic substrate opposite to the polymer film layer or the side of the second protective film opposite to the inorganic substrate is within a specific range, even if a laminate of multiple sheets is stacked and stored for a long period of time, it can be easily removed individually. There is no particular upper limit for the surface roughness, but considering that the first protective film and the second protective film are preferably made of the same material, it is preferably 1.2 μm or less, and more preferably 1 μm or less.

[0083] In the first laminate of the present invention, the surface roughness Ra of the side of the inorganic substrate opposite to the polymer film layer is 0.02 μm to 1.2 μm. From the perspective that even when multiple laminates are stacked and stored for a long period, the surface roughness does not adhere to the protective film surface, and can be easily removed individually, thus improving handling ability, it is preferable to have a roughness of 0.025 μm or more, more preferably 0.03 μm or more, and even more preferably 0.05 μm or more. Furthermore, it is preferable to have a roughness of 1.15 μm or less, and even more preferably 1.1 μm or less. As a method for controlling the surface roughness of the inorganic substrate within a specific range, polishing methods such as shot blasting and wet blasting can be used.

[0084] In the first laminate of the present invention, the coefficient of kinetic friction between the side opposite to the polymer film layer of the first protective film and the side opposite to the polymer film layer of the inorganic substrate is preferably in the range of 0.02 to 0.25. From the perspective that even when multiple layers of the first laminate are stacked and stored for a long period, the friction does not adhere to the protective film surface, allowing for easy individual removal and improved processability, the coefficient of kinetic friction is preferably 0.05 to 0.24, and more preferably 0.10 to 0.23. The coefficient of kinetic friction can be achieved by controlling the surface roughness of the side opposite to the polymer film layer of the first protective film and the side opposite to the polymer film layer of the aforementioned inorganic substrate within the aforementioned range.

[0085] In the second laminate of the present invention, the coefficient of kinetic friction between the surface of the first protective film opposite to the polymer film layer and the surface of the second protective film opposite to the inorganic substrate is preferably in the range of 0.02 to 0.25. From the perspective that even when the laminate is bundled in multiple stacks and stored for a long period, it does not adhere to the protective film surface, can be easily removed individually, and has better processability, the coefficient of kinetic friction is preferably 0.05 to 0.24, and more preferably 0.10 to 0.23. The aforementioned coefficient of kinetic friction can be achieved by controlling the surface roughness of the surface of the first protective film opposite to the polymer film layer and the surface of the second protective film opposite to the inorganic substrate within the aforementioned range.

[0086] In the second laminate of the present invention, the coefficient of kinetic friction between the surfaces of the second protective film opposite to the inorganic substrate is preferably in the range of 0.02 to 0.25. From the perspective that even when the laminate is bundled in multiple stacks and stored for a long period, it does not adhere to the protective film surface, allowing for easy individual removal and improved processability, the coefficient of kinetic friction is preferably 0.05 to 0.24, and more preferably 0.10 to 0.23. The aforementioned coefficient of kinetic friction can be achieved by controlling the surface roughness of the surface of the second protective film opposite to the inorganic substrate within the aforementioned range.

[0087] In this invention, multiple, preferably four or more, or more than ten, laminates described above can be stacked to form a stack. When stacking, the laminates can have the same or different orientations, but the same orientation is preferred. In this invention, since the coefficient of kinetic friction between the contacting surfaces is within a specific range when forming a stack, the laminates can be easily removed individually from the stack. Furthermore, it is acceptable to use only laminates of the same type or to randomly use laminates of different types. Preferably, only laminates of the same type are used for stacking. Examples of preferred stacking methods include stacking only multiple sheets of the first laminate and stacking only multiple sheets of the second laminate.

[0088] In this invention, the laminate can be stored in such a stacked state. During storage, it is preferable to bundle the aforementioned laminate in a stacked state. The stacking system of this invention can be used to store the laminate in any of the following situations: the stacked inorganic substrate is stored in a horizontal orientation, stored in a vertical orientation, or stored at an inclination of approximately 75 to 89 degrees, close to vertical.

[0089] In this invention, the laminated body can be transported in the stacked state obtained in this way. During transportation, it is preferable to bundle the aforementioned laminated body in a stacked state. The stacking of this invention can correspond to any of the following situations: transporting the stacked inorganic substrates while maintaining them in a horizontal direction, transporting the stacks while maintaining them in a vertical direction, or transporting them while maintaining them in a state close to vertical and tilted at approximately 75 to 89 degrees. [Example]

[0090] The present invention is illustrated in more detail below with examples, but the present invention is not limited to the following examples. The physical property evaluation methods in the following examples are as follows.

[0091] <Surface Roughness> The surface roughness Ra is measured using a stylus-type surface roughness meter in accordance with ISO 25178-2:2012.

[0092] <Coefficient of Kinetic Friction> The coefficient of kinetic friction is determined by mounting a friction coefficient fixture on a tensile testing machine according to JIS K 7125:1999. Tensile testing machine: Shimadzu Corporation "Autograph (registered trademark) AG-IS"

[0093] <Preparation of Polyimide Solution A1> In a reaction vessel equipped with a nitrogen inlet tube, a Dean-Stark tube and a reflux tube, a thermometer, and a stir bar, nitrogen gas was introduced while 19.86 parts by mass of 4,4'-diaminodiphenyl sulfonate (4,4'-DDS), 4.97 parts by mass of 3,3'-diaminodiphenyl sulfonate (3,3'-DDS), and 80 parts by mass of γ-butyrolactone (GBL) were added. Next, at room temperature, 31.02 parts by mass of 4,4'-oxyphthalic anhydride (ODPA), 24 parts by mass of GBL, and 13 parts by mass of toluene were added, and the temperature was raised to an internal temperature of 160°C. The mixture was then heated under reflux at 160°C for 1 hour to carry out amide impregnation. After amide impregnation, the temperature was raised to 180°C, and the reaction continued while toluene was removed. After reacting for 12 hours, the oil bath was removed and the mixture was brought back to room temperature. GBL was then added at a solid content of 20% by mass to obtain a polyimide solution A1 with a reduced viscosity of 0.70 dl / g.

[0094] <Preparation of Polyacrylic Acid Solution B1> After purging the reaction vessel equipped with a nitrogen inlet tube, reflux tube, and stir bar with nitrogen, 33.36 parts by mass of 2,2'-bis(trifluoromethyl)benzidine (TFMB) was completely dissolved in 270.37 parts by mass of dimethylacetamide (DMAc). Then, 9.81 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride (CBDA), 11.34 parts by mass of 3,3',4,4'-biphenyltetracarboxylic acid, and 4.85 parts by mass of (ODPA) were added directly in batches in solid state, and the mixture was stirred at room temperature for 24 hours. Then, 165.7 parts by mass of DMAc were added for dilution to obtain polyacrylic acid solution B1 with 18% by mass of solids and a reduced viscosity of 2.7 dl / g (CBDA / BPDA / ODPA / TFMB = 0.48 / 0.37 / 0.15 / 1.00 (Morbies)).

[0095] <Preparation of Polyacrylic Acid Solution B2> After purging the reaction vessel equipped with a nitrogen inlet tube, reflux tube, and stir bar with nitrogen, 22.73 parts by mass of 4,4'-diaminobenzylaniline (DABAN), 201.1 parts by mass of N,N-dimethylacetamide (DMAc), and a dispersion (Nissan Chemical Industries, Ltd. "Snowtex (registered trademark) DMAC-ST-ZL") formed by dispersing colloidal silica (lubricant) in dimethylacetamide were added, such that the colloidal silica (lubricant) accounted for 0.4% by mass of the total polymer solids in the polyacrylic acid solution, and completely dissolved. Next, 22.73 parts by mass of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) were added directly in solid form in batches, and the mixture was stirred at room temperature for 24 hours. Then, 173.1 parts by mass of DMAc were added for dilution to obtain polyamide solution B2 with a solid content (NV) of 12% by mass and a reduced viscosity (ηsp / C) of 3.10 dl / g.

[0096] <Preparation of Protective Film Substrate> The following are used as protective film substrates: PET film with a single-sided sandblasted matte finish (E5100) manufactured by Toyobo Co., Ltd., 25μm thickness; Torayfan (registered trademark) polypropylene film with a single-sided corona treatment (26μm thickness) manufactured by Toyobo Co., Ltd., 100μm thickness.

[0097] <Preparation of Adhesive Layer and Fabrication of Protective Film> While stirring 100 parts by weight of a carbamate-based solvent adhesive US-902-50 (manufactured by LION Speciality Chemicals, ethyl acetate solvent, 50% solids), 5.4 parts by weight of a crosslinking agent (manufactured by LION Speciality Chemicals) and 2 parts by weight of a UV absorber (Cyasorb UV-3638 (manufactured by CYTEC)) were added, and the mixture was reacted at 40°C for 20 minutes. After filtering the resulting solution through a PTFE cartridge filter (0.45μm), the solution was coated onto a protective film substrate to achieve a final film thickness of 10μm, and heated at 100°C for 2 minutes to obtain the protective film. E5100 (adhesive applied to a non-sandblasted matte surface) was used as the substrate in PF1, Torayfan was used as the substrate in PF2, and Cosmoshine was used as the substrate in PF3.

[0098] <Preparation of the laminate L1> Using a rod coater, a polyimide solution A1 was cast onto a rectangular alkali-free glass S1 (with a wet sandblasting treatment on the uncoated surface of NEG OA11G) measuring 500mm × 400mm (circumscribed circle diameter of 640.3mm) and 0.7mm thick, with a drying thickness of 15μm. The glass and the dried polyimide solution laminate were then dried in a hot air oven at 110°C for 1 hour. The resulting laminate of glass and the dried polyimide solution was then slowly heated to 330°C at a rate of 5°C / min and heated for 10 minutes to evaporate the solvent, resulting in a laminate of a polyimide film and an alkali-free glass plate with a thickness of approximately 15μm. A protective film PF1 (adhesive coating surface) was then bonded to the surface of the polyimide film, resulting in a laminate L1 of a polyimide film and an alkali-free glass plate with the first protective film attached.

[0099] <Preparation of Lamination L2> Using a rod coater, polyamide solution B1 was cast onto a 500mm × 400mm, 0.7mm thick rectangular alkali-free glass (with wet sandblasting treatment applied to the uncoated surface of NEG OA11G) to a drying thickness of 15μm. The glass and the dried polyamide solution lamination were then dried in a hot air oven at 100°C for 1 hour. The resulting glass-polyamide solution lamination was then slowly heated to 350°C at a rate of 5°C / min and further heated for 10 minutes to induce amide imidization, resulting in a polyimide film and alkali-free glass plate lamination with a thickness of approximately 15μm. A protective film PF1 (adhesive coating surface) was then bonded to the surface of the polyimide film, resulting in a polyimide film and alkali-free glass plate lamination L2 with the first protective film attached.

[0100] <Fabrication of Laminate L3> A silane coupling agent is coated onto a glass plate, and a polyimide film is laminated and heated on it to obtain a laminate with glass. First, the silane coupling agent is coated onto the glass substrate using the apparatus shown in Figure 5. Figure 5 is a schematic diagram of the apparatus for coating the silane coupling agent onto the glass substrate. The glass substrate is OA11G glass (manufactured by NEG Corporation) cut to 500mm × 400mm size, with the uncoated side treated by wet sandblasting. Furthermore, the glass substrate is washed with pure water for 2 minutes using an ultrasonic cleaner, and then the moisture is removed by an air knife. 150g of 3-aminopropyltrimethoxysilane (silane coupling agent Shin-Etsu Chemical KBM903) is placed in a 1L capacity chemical bath, and the outer side is heated to 43°C in a water bath. The exhausted steam was then sent into the chamber along with clean dry air. The gas flow rate was set to 25 L / min, and the substrate temperature was set to 24 °C. The temperature of the clean dry air was 23 °C, and the humidity was 1.2% RH. A differential pressure gauge confirmed that the chamber was under a negative pressure of approximately 2 Pa due to the exhaust being connected to a negative pressure exhaust port.

[0101] Next, an Upilex 25S (450mm × 450mm) polymer film layer manufactured by Ube Industries Co., Ltd. was laminated onto the aforementioned silane coupling agent layer to obtain a laminate. During lamination, an MCK MRK650Y laminator was used, with the following lamination conditions: compressed air pressure: 0.6MPa, temperature: 22°C, humidity: 55%RH, and lamination speed: 50mm / sec. This polyimide film / glass laminate was heated at 200°C for 30 minutes to obtain a laminate of polyimide film and alkali-free glass plate. A protective film PF1 (adhesive coating surface) was laminated onto the surface of the polyimide film to obtain a laminate L3 of polyimide film and alkali-free glass plate with the first protective film attached.

[0102] <Preparation of Laminate L4> Except for using Xenomax (registered trademark) F15LR2 manufactured by Toyobo Co., Ltd. as the polyimide film, a laminate of polyimide film and glass with a first protective film is obtained in the same manner as laminate L3. A protective film PF1 is laminated to the side of the glass opposite to the polyimide film to obtain laminate L4 of polyimide film and alkali-free glass plate with first and second protective films.

[0103] <Preparation of Lamination L5> Using a rod coater, polyamide solution B2 was cast onto a rectangular alkali-free glass S2 (NEG OA11G) measuring 500mm × 400mm and 0.7mm thick, with a drying thickness of 15μm. The glass and the dried polyamide solution lamination were then dried in a hot air oven at 100°C for 1 hour. The resulting glass-polyamide solution lamination was then slowly heated to 350°C at a rate of 5°C / min and heated for 10 minutes to induce amide imidization, resulting in a polyimide film and alkali-free glass plate lamination with a thickness of approximately 15μm. A protective film PF1 (adhesive coating) was then bonded to the surface of the polyimide film, resulting in a polyimide film and alkali-free glass plate lamination with the first protective film attached. A protective film PF1 (adhesive coating surface) is laminated onto the glass on the side opposite to the polyimide film to obtain a laminate L5 of polyimide film with first and second protective films and alkali-free glass plate.

[0104] <Preparation of Lamination L6> Using a rod coater, a polyimide solution A1 was cast onto a 500mm × 400mm rectangular alkali-free glass (NEG OA11G) with a thickness of 0.7mm to a dry thickness of 15μm. The glass and the dried polyimide solution lamination were then dried in a hot air oven at 110°C for 1 hour. The resulting glass-polyimide solution lamination was then slowly heated to 300°C at a rate of 5°C / min and further heated for 10 minutes to evaporate the solvent, resulting in a polyimide film and alkali-free glass plate lamination with a thickness of approximately 15μm. A protective film PF1 (adhesive coating) was then bonded to the surface of the polyimide film to obtain a polyimide film and alkali-free glass plate lamination with the first protective film attached. A protective film PF2 is laminated onto the glass on the opposite side of the polyimide film to obtain a thermosetting polyimide film with the first and second protective films attached and an alkali-free glass plate laminate L6.

[0105] <Fabrication of laminate L7> Except that wet sandblasting of the glass is not performed and the second protective film is not used, laminate L7, which is a polyimide film with the first protective film and an alkali-free glass plate, is obtained in the same way as laminate L4.

[0106] <Fabrication of laminate L8> Except for not performing wet sandblasting on the glass, laminate L8, which is the same as laminate L1, is obtained by having a polyimide film with a first protective film and an alkali-free glass plate.

[0107] <Fabrication of laminate L9> Except for not performing wet sandblasting on the glass and using PF3 as the second protective film, a laminate L9 consisting of a polyimide film with the first and second protective films and an alkali-free glass plate is obtained in the same way as laminate L3.

[0108] <Processability Evaluation of Laminate Stacks> On a flat table, 10 laminates are stacked horizontally with the glass plates facing down, forming a laminate stack. On top of this stack are a glass plate of the same size, a 50μm thick polyethylene film, and a 3mm thick polysiloxane sheet of the same size as the glass plate. A 10mm thick stainless steel plate is then placed as a load, and the stack is left to stand at room temperature for 10 days. After 10 days, the load, polysiloxane sheet, and polyethylene film are removed, and the laminates are manually checked to see if they can be removed one by one from the stack of 10 laminates. Cases where the laminates can be removed without any problems are considered "processable" (○), while cases where any problems occur during removal are considered "processable" (×). The results are shown in Table 1. Furthermore, in most cases of processability failure, the back of the glass plate was tightly sealed to the protective film, but when the glass plate was lifted, the protective film of the lower laminates peeled off.

[0109] [Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 laminated body L1 L2 L3 L4 L5 L6 L7 L8 L9 First protective film PF1 PF1 PF1 PF1 PF1 PF1 PF1 PF1 PF1 Inorganic substrate S1 S1 S1 S1 S2 S2 S2 S2 S2 Glass OA11G OA11G OA11G OA11G OA11G OA11G OA11G OA11G OA11G Single-sided wet sandblasting have have have have none none none none none polymer thin film layer A1 B1 Upilex Xenomax B2 A1 Xenomax A1 Upilex Ra (μm) of inorganic substrates※1 1 1.1 1 1.1 0.0007 0.0007 0.0007 0.0007 0.0007 Second protective film none none none PF1 PF1 PF2 none none PF3 Ra (μm) of the second protective film※2 - - - 0.037 0.037 0.12 - - 0.003 Inorganic substrate and first protective film Coefficient of kinetic friction※3 0.23 0.23 0.23 0.15 0.15 0.12 0.75 0.75 0.61 First protective film and second protective film Coefficient of kinetic friction※4 - - - 0.12 0.11 0.1 - - 0.42 The second protective film between each other Coefficient of kinetic friction※5 - - - 0.13 0.13 0.06 - - 0.72 rationality at the stacking of layers ○ ○ ○ ○ ○ ○ × × × ※1: Value of the face opposite to the polymer film layer ※2: Value of the face opposite to the inorganic substrate ※3: Value of the face opposite to the polymer film layer ※4: Value of the face opposite to the polymer film layer for the first protective film system, and value of the face opposite to the inorganic substrate for the second protective film system ※5: Value of the face opposite to the inorganic substrate

[0110] <Transport Suitability Evaluation of Laminate Stacks> In the combination of lamellae considered to be well handled in the aforementioned treatmentability evaluation, the respective 10 sets of pools were superimposed to form a stack of lamellae. Packed in kraft body stacked in kraft paper, placed in boxes made of plastic corrugated boards together with polyaminoformate buffers with a thickness of 20mm, loaded on the carrier of a small truck, carried on a general national highway for 30km, unpacked at the arrival point, and again evaluated for handling by the aforementioned method. In either combination there are no special problems and the buildup body can be removed. Also, there were no accidents such as glass breakage during transportation. [Possibility of industrial utilization]

[0111] As mentioned above, the inorganic substrate and polymer thin film layer of the present invention have excellent operability, transportability, can be treated in a state where the polymer thin film face is protected by resorting to the protective film, and the protective film can be stripped without problem during processing of the polymer thin film face. The present invention can be usefully utilized in the fabrication of a flexible device or the like in which the polymer thin film is stripped from an inorganic substrate after micromachining of the polymer thin film using such a laminated body. [Brief explanation of the diagram]

[0018] Figure 1(a) of FIG. 1(b) is an example of a process of preparing an inorganic substrate 12 / polymer thin film layer 15 integrally by applying a polymer solution or polymer precursor solution 11 on an inorganic substrate 12 , which is processed into a continuous sheet of a second integrally by means of a first protective film 14 and a second protective film 16 attached to the surface of the polymer thin film layer 15 . 2 shows a schematic representation of the cross-sectional configuration of a stack superimposed with 4 pieces of the 1st integral body (1st protective film 23 / polymer thin film layer 22 / inorganic substrate 21). The laminated system becomes continuous sheets, folded according to each laminated body. 3 is a schematic diagram showing the cross-sectional configuration of a stack superimposed with 4 sheets of the 2nd integral body (1st protective film 33 / polymer thin film layer 31 / inorganic substrate 32 / 2nd protective film 34). The laminate system containing the protective film becomes a continuous sheet, folded per laminate body. 4 is a schematic diagram showing the cross-sectional configuration of a stack superimposed with 4 sheets of the 2nd integral body (1st protective film 43 / polymer thin film layer 42 / inorganic substrate 41 / 2nd protective film 44). 5 is a schematic diagram used to illustrate the silane coupling agent application method of this patent.

Claims

1. A first laminate, characterized in that it sequentially comprises an inorganic substrate, a polymer film layer, and a first protective film, wherein the surface roughness Ra of the side of the inorganic substrate opposite to the polymer film layer is 0.02 μm to 1.2 μm, and the coefficient of kinetic friction between the side of the first protective film opposite to the polymer film layer and the side of the inorganic substrate opposite to the polymer film layer is in the range of 0.02 to 0.

25.

2. The first laminate as claimed in claim 1, wherein the diameter of the outer circle of the inorganic substrate is 310 mm or more.

3. A second laminate, characterized in that it sequentially comprises a second protective film, an inorganic substrate, a polymer film layer, and a first protective film, wherein the surface roughness Ra of the side of the second protective film opposite to the inorganic substrate is 0.02 μm to 1.2 μm.

4. The second laminate as claimed in claim 3, wherein the coefficient of kinetic friction of the surface of the first protective film opposite to the polymer film layer and the surface of the second protective film opposite to the inorganic substrate is in the range of 0.02 to 0.

25.

5. The second laminate as claimed in claim 3 or 4, wherein the coefficient of kinetic friction between the surfaces of the second protective film opposite to the inorganic substrate is in the range of 0.02 to 0.

25.

6. The second laminate as claimed in claim 3 or 4, wherein the diameter of the outer circle of the inorganic substrate is 310 mm or more.

7. A stack of laminates, characterized in that four or more laminates of any one of claims 1 to 6 are overlapped in the same direction in the layer direction.

8. A method for storing a laminate, characterized in that it is stored in the form of a stack of laminates as described in claim 7.

9. A method for transporting laminates, characterized in that the laminates are transported in a stacked form as described in claim 7.

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