Film laminated metal plate and method for manufacturing the same, and flexible electronic substrate and organic el substrate

Abstract

Provided are a film-laminated metal sheet, a method for producing the same, and a flexible electronic substrate and an organic EL substrate, which satisfy smoothness, heat resistance, flexibility, and gas barrier properties, have low environmental load, and have excellent productivity. The film-laminated metal sheet is a film-laminated metal sheet coated on at least one side with a resin film, wherein the arithmetic mean roughness Sa of the surface of the resin film is 0.030 μm or less, the maximum peak height Sp of the surface of the resin film is 0.30 μm or less, and the maximum valley depth Sv of the surface of the resin film is 1.0 μm or less.

Description

Technical Field

[0001] This invention relates to film-laminated metal sheets and their manufacturing methods, as well as substrates for flexible electronics and substrates for organic EL. Background Technology

[0002] Flexible electronics is a general term for technologies that utilize electronic circuits characterized by their flexibility and bendability. Low costs have been achieved through organic electronics based on organic materials, coating, and printing. Furthermore, by combining these technologies with printed electronics, which allows for easy device fabrication, a wide variety of functional products can be created. Flexible electronics encompasses a wide range of technologies, including organic EL (Electro-Luminescence), organic thin-film solar cells, organic transistors, electronic paper, flexible batteries, and various flexible sensors.

[0003] Previously, substrates for flexible electronics such as organic electroluminescent substrates (ELs) primarily used glass, which exhibits excellent planarity, heat resistance, and gas barrier properties, and resin films, which offer excellent flexibility. However, satisfying all the most crucial properties for flexible electronics substrates—smoothness, heat resistance, gas barrier properties, and flexibility—is not easy. Therefore, attempts have been made to achieve flexibility by thinning or increasing the strength of glass, or to provide gas barrier properties by adding a gas barrier layer to the surface of the resin film. However, most of these methods suffer from insufficient performance or high cost. Therefore, to solve these problems, methods of coating insulating films onto metal plates have been proposed.

[0004] Patent documents 1-3 disclose methods for coating insulating films onto metal plates. Patent document 1 proposes a method for forming an insulating film containing at least one of Al₂O₃ and SiO₂, and an insulating film formed from a silica-based inorganic-organic hybrid material, on steel with controlled Al and Si content through thermal oxidation. Patent document 2 proposes a method for forming an insulating film on a metal plate by baking a film-forming composition containing a thermosetting resin and a solid pigment volume fraction of 20% or less. Patent document 3 also discloses a metal plate formed by laminating a thermoplastic resin film containing a solid pigment volume fraction of 20% or less with an adhesive.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2016 / 001971

[0008] Patent Document 2: Japanese Patent Application Publication No. 2014-208479

[0009] Patent Document 3: Japanese Patent Application Publication No. 2015-195315 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] However, the method described in Patent Document 1 results in a high environmental impact due to the use of organic solvents and the requirement for high-temperature heat treatment. Furthermore, since the insulating film is a thin film primarily composed of inorganic materials, it is susceptible to short circuits caused by pinholes and has poor flexibility. The method described in Patent Document 2 also includes a process involving the use of organic solvents and drying and curing processes requiring heat treatment. Moreover, the method described in Patent Document 3 includes a process that results in poor productivity due to the costly application and time-consuming curing of the adhesive. Additionally, poor insulation occurs due to the steep unevenness of the thermoplastic film surface, resulting in insufficient insulation.

[0012] The present invention was made in view of the above-mentioned problems. Its object is to provide a film-laminated metal plate and a method for manufacturing the same, which not only meet the requirements of smoothness, heat resistance, flexibility and gas barrier properties, but also have low environmental impact and excellent productivity, as well as substrates for flexible electronics and substrates for organic EL.

[0013] Methods for solving problems

[0014] This invention is based on the above insights, and its main points are as follows.

[0015] [1] A film-laminated metal sheet, wherein at least one side is covered with a resin film.

[0016] The arithmetic mean roughness Sa of the aforementioned resin film surface is less than 0.030 μm, the maximum peak height Sp of the aforementioned resin film surface is less than 0.30 μm, and the maximum valley depth Sv of the aforementioned resin film surface is less than 1.0 μm.

[0017] [2] The film-laminated metal plate as described in [1], wherein the kurtosis Sku of the aforementioned resin film surface is 3.0 or less.

[0018] [3] A film-laminated metal plate as described in [1] or [2], wherein the ash content of the aforementioned resin film is less than 1000 ppm.

[0019] [4] A film-laminated metal plate as described in any one of [1] to [3], wherein the static friction coefficient μs of the aforementioned resin film is 0.10 or more and 1.0 or less.

[0020] [5] A film-laminated metal sheet as described in any one of [1] to [4], wherein the ratio (ΔHc / ΔHm) of the cold crystallization heat ΔHc to the melting heat ΔHm of the aforementioned resin film as determined by DSC is 0.30 or less.

[0021] [6] A film-laminated metal plate as described in any one of [1] to [5], wherein the glass transition temperature Tg of the aforementioned resin film is above 120°C and below 200°C.

[0022] [7] A film-laminated metal plate as described in any one of [1] to [6], wherein the thickness of the aforementioned resin film is more than 10 μm and less than 100 μm.

[0023] [8] A film-laminated metal plate as described in any one of [1] to [7], wherein the main component of the aforementioned resin film is any one of polyester resin, acrylic resin, or polycarbonate resin.

[0024] [9] A method for manufacturing a film-laminated metal sheet, which is the method for manufacturing a film-laminated metal sheet as described in any one of [1] to [8], wherein the aforementioned resin film is coated onto the metal sheet by hot pressing.

[0025]

[10] A flexible electronic substrate, wherein a film-laminated metal plate is used as described in any one of [1] to [8].

[0026]

[11] An organic EL substrate, wherein the film-laminated metal plate is used as described in any one of [1] to [8].

[0027] Invention Effects

[0028] According to the present invention, a film-laminated metal sheet can be provided that not only meets the requirements for smoothness, heat resistance, flexibility, and gas barrier properties as a substrate for flexible electronics, but also has low environmental impact and excellent productivity. Therefore, the film-laminated metal sheet of the present invention can be used as a substrate for flexible electronics and a substrate for organic EL. Detailed Implementation

[0029] The present invention will now be described.

[0030] The present invention relates to a film-laminated metal sheet, at least one side of which is coated with a resin film. The metal sheet excels in balancing flexibility and gas barrier properties, as required for organic EL applications. Furthermore, by coating at least one side with a resin film, the resin film can be imparted with smoothness and electrical insulation. Additionally, by bonding the resin film to the metal sheet, dimensional changes in the film can be suppressed even when heated, exhibiting superior heat resistance compared to a resin film alone.

[0031] In the film-laminated metal plate of the present invention, the arithmetic mean roughness Sa of the resin film surface is 0.030 μm or less. More preferably, the arithmetic mean roughness Sa of the resin film surface is 0.025 μm or less, even more preferably 0.020 μm or less, and particularly preferably 0.015 μm or less. When the arithmetic mean roughness Sa exceeds 0.030 μm, for example, when used as a substrate for organic EL, there is a possibility of minor short circuits, leakage current, and reduced luminous efficiency when voltage is applied. Furthermore, from the above viewpoint, the closer the arithmetic mean roughness Sa is to 0, the more ideal it is; in practice, 0.001 μm is the lower limit. For the arithmetic mean roughness Sa of the resin film surface to be within the above range, it is important to laminate the resin film in a manner that does not deteriorate the surface shape of the resin film. Therefore, a resin film without lubricant or with a small amount of lubricant micro-dispersed therein can be used, as described later. In addition, since the arithmetic mean roughness Sa can also be worsened by scratches during handling, transfer marks from hot press rollers, etc., it is preferable to apply a protective film to the side of the resin film that is not in close contact with the metal plate beforehand.

[0032] Furthermore, in the film-laminated metal plate of the present invention, the maximum peak height Sp on the surface of the resin film is 0.30 μm or less. More preferably, the maximum peak height Sp on the surface of the resin film is 0.25 μm or less, even more preferably 0.20 μm or less, and particularly preferably 0.15 μm or less. When the maximum peak height Sp on the surface of the resin film exceeds 0.30 μm, for example, when used as a substrate for organic EL, a non-luminescent defect called a black spot may occur, resulting in partial non-luminescence. From the above viewpoint, the closer the maximum peak height Sp is to 0, the better; in fact, 0.001 μm is the lower limit. For the maximum peak height Sp on the surface of the resin film to be within the above range, it is important to laminate the resin film in a manner that does not deteriorate the surface shape of the resin film. Therefore, a resin film without lubricant or with a small amount of lubricant micro-dispersed, as described later, can be used. In addition, the maximum peak height Sp can also be deteriorated by foreign matter adhering during transport or by air bubbles being introduced between the film and the metal plate during hot-press lamination. Therefore, it is preferable to pre-apply a protective film to the surface of the resin film that is not in close contact with the metal plate, or to control the lamination conditions to suppress the incorporation of air bubbles.

[0033] Furthermore, in the film-laminated metal plate of the present invention, the maximum valley depth Sv of the resin film surface is 1.0 μm or less. More preferably, the maximum valley depth Sv of the resin film surface is 0.50 μm or less, even more preferably 0.30 μm or less, and particularly preferably 0.15 μm or less. When the maximum valley depth Sv of the resin film surface exceeds 1.0 μm, for example, when used as a substrate for organic EL, a short circuit may occur, resulting in complete non-luminescence. Furthermore, from the above viewpoint, the closer the maximum valley depth Sv is to 0, the more ideal it is; practically, 0.001 μm is the lower limit. For maintaining the Sv of the resin film surface within the above range, it is important to use a resin film with high surface smoothness and to prevent the surface shape of the resin film from deteriorating during lamination. In addition, Sv can also deteriorate due to scratches during handling, transfer marks from hot press rollers, and excessive pressing during lamination. Therefore, it is preferable to pre-apply a protective film to the surface of the resin film that does not contact the metal plate, or to control the lamination temperature and the pressure applied.

[0034] In the film-laminated metal plate of the present invention, the kurtosis (Sku) of the resin film surface is preferably 3.0 or less. More preferably, the kurtosis (Sku) of the resin film surface is 2.8 or less, even more preferably 2.6 or less, and particularly preferably 2.5 or less. If the kurtosis (Sku) of the resin film surface is 3.0 or less, then, for example, when used as a substrate for organic EL, the reduction in luminous efficiency due to leakage current and the generation of black spots are further suppressed. Furthermore, from the above viewpoint, the closer the kurtosis (Sku) is to 0, the more ideal it is; in fact, 0.001 is the lower limit. For the kurtosis (Sku) of the resin film surface to be within the above range, it is important to press the resin film in a manner that does not deteriorate the surface shape of the resin film during lamination. Therefore, a resin film without lubricant or with a small amount of lubricant micro-dispersed, as described later, can be used. In addition, the kurtosis (Sku) can also deteriorate due to the transfer of the surface shape of the hot-pressing roller; therefore, it is preferable to pre-apply a protective film to the surface of the resin film that is not in contact with the metal plate.

[0035] In the film-laminated metal plate of the present invention, the ash content of the resin film is preferably 1000 ppm (by mass, the same below) or less. More preferably, the ash content of the resin film is 800 ppm or less, even more preferably 600 ppm or less, and particularly preferably 500 ppm or less. If the ash content of the resin film is 1000 ppm or less, then, for example, when used as a substrate for organic EL, the reduction in luminous efficiency due to leakage current and the generation of black spots are further suppressed. To keep the ash content of the resin film within the above-mentioned range, it is preferable to use a resin film that does not contain lubricant or contains a small amount of micro-dispersed lubricant, as described later, and to perform hot-press lamination without the use of an adhesive.

[0036] In the film-laminated metal plate of the present invention, the static friction coefficient μs of the resin film is preferably 0.10 or more and 1.0 or less. The lower limit of the static friction coefficient μs of the resin film is more preferably 0.30 or more, further preferably 0.40 or more, and particularly preferably 0.50 or more. Furthermore, the upper limit of the static friction coefficient μs of the resin film is more preferably 0.95 or less, further preferably 0.90 or less, and particularly preferably 0.85 or less. If the static friction coefficient μs of the resin film is 1.0 or less, for example, when used as a substrate for organic EL, the generation of defects on the rollers during the manufacturing process is further suppressed. On the other hand, if the static friction coefficient μs of the resin film is 0.10 or more, for example, when used as a substrate for organic EL, the serpentine motion on the rollers during the manufacturing process is further suppressed. To ensure that the μs of the resin film is within the above-mentioned range, it is preferable to use a resin film that does not contain lubricant or has a small amount of lubricant micro-dispersed therein, as described later. Furthermore, it is preferable to use a film formed from any one of polyester resin, acrylic resin, or polycarbonate resin.

[0037] In the film-laminated metal plate of the present invention, the ratio (ΔHc / ΔHm) of the cold crystallization heat ΔHc to the melting heat ΔHm of the resin film, as measured by DSC (Differential Scanning Calorimeter), is preferably 0.30 or less.

[0038] Here, DSC refers to Differential Scanning Calorimetry. The ΔHc / ΔHm ratio of the resin film is more preferably 0.25 or less, further preferably 0.20 or less, and particularly preferably 0.15 or less. A smaller ΔHc / ΔHm ratio is preferred; in the case of no cold crystallization (i.e., ΔHc = 0 J / g), ΔHc / ΔHm is 0, which is essentially the lower limit. The phrase "no cold crystallization" refers to a resin film formed from a crystalline thermoplastic resin, where crystallization is sufficiently complete and will not be further promoted by heat unless temporarily melted. On the other hand, the phrase "cold crystallization" refers to the presence of a large amount of amorphous material within the resin film, which crystallizes due to heat. It should be noted that when crystalline thermoplastic resin is hot-pressed onto a metal plate, heat is typically used to melt the surface of the resin film and bond it to the metal plate; therefore, the molten resin becomes amorphous upon cooling. However, if the surface of the crystalline thermoplastic resin film melts excessively during hot-press lamination, the surface shape of the laminated metal sheet may sometimes deteriorate. Therefore, for the purpose of producing a film-laminated metal sheet with high smoothness, it is important to control the lamination conditions in a way that prevents the crystalline thermoplastic resin film from melting excessively during hot-press lamination, i.e., to prevent the resin film of the laminated metal sheet from undergoing cold crystallization. That is, a small ΔHc / ΔHm of the resin film means that the crystalline thermoplastic resin film is laminated in a way that prevents excessive melting during hot-press lamination. Therefore, if ΔHc / ΔHm is 0.30 or less, a film-laminated metal sheet with high smoothness can be produced, which is preferred. Furthermore, the upper limit of ΔHc / ΔHm of the resin film is 1, which means that the crystalline thermoplastic resin film is completely amorphized during hot-press lamination. It should be noted that cold crystallization does not occur in the case of amorphous resins.

[0039] In the film-laminated metal plate of the present invention, the glass transition temperature (Tg) of the resin film is preferably 120°C or higher and 200°C or lower. The lower limit of the glass transition temperature (Tg) of the resin film is more preferably 130°C or higher, further preferably 140°C or higher, and particularly preferably 150°C or higher. The upper limit of the glass transition temperature (Tg) of the resin film is more preferably 195°C or lower, further preferably 190°C or lower, and particularly preferably 185°C or lower. If the glass transition temperature (Tg) of the resin film is 200°C or lower, hot-press lamination can be performed more reliably. On the other hand, if the glass transition temperature (Tg) of the resin film is 120°C or higher, for example, when used as a substrate for organic EL (electro-optical polymer), the deformation of the resin film surface caused by heat during the manufacturing process is suppressed less. To ensure that the Tg of the resin film is within the above-mentioned range, it is preferable to use a biaxially stretched polyester resin film as described later, and to perform hot-press lamination without impairing crystallinity. Furthermore, it is preferable to use a film formed from a non-crystalline resin with a high glass transition temperature, such as acrylic resin or polycarbonate resin.

[0040] In the film-laminated metal sheet of the present invention, the thickness of the resin film is preferably 10 μm or more and 100 μm or less. The lower limit of the resin film thickness is more preferably 15 μm or more, further preferably 20 μm or more, and particularly preferably 25 μm or more. The upper limit of the resin film thickness is more preferably 80 μm or less, further preferably 60 μm or less, and particularly preferably 50 μm or less. If the resin film thickness is 10 μm or more, it is less affected by the unevenness of the metal sheet surface, resulting in a film-laminated metal sheet with a smoother resin film surface. If the resin film thickness is 100 μm or less, it is possible to obtain a film-laminated metal sheet with less impact on black spots caused by moisture contained in the resin film and the lifespan of organic EL.

[0041] In the film-laminated metal sheet of the present invention, the main component of the resin film is preferably any one of polyester resin, acrylic resin, and polycarbonate resin. It should be noted that the term "main component" means that the proportion of a specific component in the total components is 80% by mass or more, more preferably 85% by mass or more, further preferably 90% by mass or more, and particularly preferably 95% by mass or more. It can also be 100% by mass.

[0042] The polyester resin used in the film-laminated metal sheet of the present invention is preferably a resin obtained by polymerization of monomers mainly composed of aromatic dicarboxylic acids or aliphatic dicarboxylic acids and diols, or a mixture thereof.

[0043] Examples of aromatic dicarboxylic acids here include terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfonyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, and sodium isophthalate-5-sulfonate. Examples of aliphatic dicarboxylic acids include oxalic acid, succinic acid, adipic acid, octanoic acid, sebacic acid, dimer acids, maleic acid, fumaric acid, dodecanoic acid, cyclohexanedicarboxylic acid, and their ester derivatives. Only one of these acid components may be used, or two or more may be used in combination. Furthermore, hydroxycarboxylic acids such as p-hydroxybenzoic acid may be copolymerized.

[0044] In addition, examples of diol components include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, neopentanediol, cyclohexanediol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis(4-hydroxyethoxyphenyl)propane, isosorbide (1,4:3,6-didehydroglucanol, 1,4:3,6-didehydro-D-sorbitol), spirodiol, bisphenol A, and bisphenol S. Ethylene glycol is preferred. Only one of these diol components may be used, or two or more may be used in combination.

[0045] From the viewpoint of adhesion to the metal sheet, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are preferred polyester resins used in the film-laminated metal sheet according to the present invention. Mixtures thereof are also preferred.

[0046] The acrylic resin used in the film-laminated metal sheet of the present invention is preferably a resin obtained by polymerization of monomers with acrylate compounds as the main constituent, or a mixture thereof. Examples of acrylate compounds include monoacrylate compounds, monomethacrylate compounds, diacrylate compounds, and dimethacrylate compounds.

[0047] Examples of monoacrylate compounds include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, pentyl acrylate, isoamyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, isodecanyl acrylate, lauryl acrylate, tridecyl acrylate, hexadecyl acrylate, stearyl acrylate, isostearyl acrylate, cyclohexyl acrylate, isobornyl acrylate, diethylene glycol acrylate, polyethylene glycol acrylate, polypropylene glycol acrylate, and 2-methoxyethyl acrylate. Esters, ethoxyethyl acrylate, 2-butoxyethyl acrylate, methoxydiethylene glycol acrylate, methoxypolyethylene glycol acrylate, dicyclopentenoxyethyl acrylate, 2-phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxypolyethylene glycol acrylate, 2-benzoyloxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, benzyl acrylate, 2-cyanoethyl acrylate, γ-acryloyloxyethyltrimethoxysilane, glycidyl acrylate, tetrahydrofurfuryl acrylate, dimethylaminoethyl acrylate, acryloyloxyethyl phosphate, acryloyloxyethylphenyl phosphate, etc.

[0048] Examples of monomethacrylate compounds include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, pentyl methacrylate, isoamyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, isodecanyl methacrylate, lauryl methacrylate, tridecyl methacrylate, hexadecyl methacrylate, stearyl methacrylate, isostearyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, diethylene glycol methacrylate, polyethylene glycol methacrylate, polypropylene glycol methacrylate, and so on. 2-Methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, dicyclopentenoxyethyl methacrylate, 2-phenoxyethyl methacrylate, phenoxydiethylene glycol methacrylate, phenoxypolyethylene glycol methacrylate, 2-benzoyloxyethyl methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, benzyl methacrylate, 2-cyanoethyl methacrylate, γ-methacryloyloxyethyltrimethoxysilane, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, dimethylaminoethyl methacrylate, methacryloyloxyethyl phosphate, methacryloyloxyethylphenyl phosphate, etc.

[0049] Examples of diacrylate compounds include ethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,3-butanediol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, reactants of 1 mole of bisphenol A, bisphenol F, or bisphenol AD ​​with 2 moles of glycidyl acrylate, diacrylates of polypropylene oxide adducts of bisphenol A, bisphenol F, or bisphenol AD, bis(acryloyloxypropyl)polydimethylsiloxane, and bis(acryloyloxypropyl)methylsiloxane-dimethylsiloxane copolymers.

[0050] Examples of dimethacrylate compounds include ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,3-butanediol dimethacrylate, neopentyl glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, a reaction product of 1 mole of bisphenol A, bisphenol F, or bisphenol AD ​​with 2 moles of glycidyl methacrylate, dimethacrylates of polypropylene oxide adducts of bisphenol A, bisphenol F, or bisphenol AD, bis(methacryloyloxypropyl)polydimethylsiloxane, and bis(methacryloyloxypropyl)methylsiloxane-dimethylsiloxane copolymers. These acrylate compounds may be used in combination with only one or more of them.

[0051] As the acrylic resin used in the film-laminated metal sheet of the present invention, polymethyl methacrylate (PMMA) is preferred from the viewpoint of good adhesion to the metal sheet. From the viewpoint of controlling the glass transition temperature, it is preferable to use the above-mentioned acrylic ester compounds other than methacrylates.

[0052] The polycarbonate resin used in the film-laminated metal sheet of the present invention is preferably a resin obtained by polymerization of aromatic dihydroxy compounds with compounds that form carbonic acid bonds, such as phosgene and diphenyl carbonate, or a mixture thereof.

[0053] Examples of aromatic dihydroxy compounds here include bis(hydroxyaryl)alkanes such as 1,1-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, and 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane; and bis(hydroxyaryl)cycloalkanes such as 1,1-bis(4-hydroxyphenyl)cyclopentane and 1,1-bis(4-hydroxyphenyl)cyclohexane. Hydrocarbons; dihydroxyaryl ethers such as 4,4'-dihydroxydiphenyl ether and 4,4'-dihydroxy-3,3'-dimethylphenyl ether; dihydroxyaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide and 4,4'-dihydroxy-3,3'-dimethylphenyl sulfide; dihydroxyaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethylphenyl sulfoxide; and dihydroxyaryl sulfones such as 4,4'-dihydroxydiphenyl sulfone and 4,4'-dihydroxy-3,3'-dimethylphenyl sulfone. Among these, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) is preferred. Only one of these aromatic dihydroxy compounds may be used, or two or more may be used in combination. Additionally, polycarbonates obtained by replacing a portion of the carbonic acid component with terephthalic acid and / or isophthalic acid components are also commonly used.

[0054] For the resin film used in the film-laminated metal plate of this invention, multifunctional compounds such as trimellitic acid, pyromellitic acid, and trimethylolpropane can also be copolymerized, provided that it does not impair the effect of this invention. Furthermore, resin components other than the main components described above can also be used for the purpose of imparting functionality. In addition to polyester resins, acrylic resins, and polycarbonate resins, the following resin components can be used as resin components: chain polyolefins such as polyethylene, polypropylene, poly(4-methylpentene-1), and polyacetal; ring-opening metathesis polymerization and addition polymerization of norbornene; alicyclic polyolefins as addition copolymers with other olefins; biodegradable polymers such as polylactic acid and polybutylene succinate; polyamides such as nylon 6, nylon 11, nylon 12, and nylon 66; aromatic polyamides; polyvinyl chloride; polyvinylidene chloride; polyvinyl alcohol; polyvinyl butyral; ethylene vinyl acetate copolymer; polyacetal; polyglycolic acid; polystyrene; styrene copolymer; polymethyl methacrylate; polyethersulfone; polyetheretherketone; modified polyphenylene ether; polyphenylene sulfide; polyetherimide; polyimide; polyarylate; tetrafluoroethylene resin; trifluoroethylene resin; trifluorochloroethylene resin; tetrafluoroethylene-hexafluoropropylene copolymer; and polyvinylidene fluoride. It should be noted that these can be copolymers or mixtures.

[0055] From the perspective of improving heat resistance, it is preferable to add 0.0001% by mass or more and 1.0% by mass or less of a known antioxidant to the resin film used in the film-laminated metal sheet of the present invention. More preferably, it is 0.001% by mass or more and 1.0% by mass or less. The type of antioxidant is not particularly limited; for example, known antioxidants classified as hindered phenols, hydrazines, phosphites (esters), etc., can be used.

[0056] The resin film used in the film-laminated metal sheet of the present invention may contain various additives other than the antioxidants mentioned above, to a extent that does not impair the effects of the present invention. Examples include slip agents, crystal nucleating agents, heat stabilizers, antistatic agents, anti-blocking agents, fillers, viscosity modifiers, etc. These can also be mixed into the resin film. In particular, slip agents and anti-blocking agents, which are lubricants, can be mixed with a solvent and applied to the film surface in slurry form and dried to impart functionality; this is preferred from the viewpoint that they can be dispersed in small amounts on the surface of the resin film. It should be noted that, from the viewpoint of controlling the smoothness of the film-laminated metal sheet, i.e., the arithmetic mean roughness Sa, maximum peak height Sp, and ku of the resin film surface, within a small and preferred range, and from the viewpoint of controlling the static friction coefficient μs within a preferred range to suppress defects and serpentine movement on the rollers during the manufacturing process when used as a substrate for organic EL, it is preferable to use a resin film with a small amount of lubricant dispersed as described above, and particularly preferable to be lubricant-free. When a small amount of lubricant is dispersed, the average particle size of the lubricant is set to 0.3 μm or less. Preferably, the ash content is 0.2 μm or less, and more preferably 0.1 μm or less. Whether the resin film contains no lubricant or only a small amount can be determined by measuring the ash content. In the case of no lubricant, the ash content of the resin film is 500 ppm or less.

[0057] Regarding the resin film used in the film-laminated metal sheet of the present invention, a single-layer configuration of the same resin composition is also preferred, but a configuration with two or more layers is preferred for the purpose of imparting functionality. For example, the surface layer laminated on the bonding surface of the metal sheet can have an uneven surface for the purpose of preventing adhesion between films, and the opposite surface layer can be made of a resin composition with excellent smoothness. Thus, it is possible to take into account both the performance as a resin film and the function as a flexible electronic substrate. As for the lamination direction, not only the lamination in the thickness direction mentioned above, but also lamination in the length direction and the width direction are also possible. From the viewpoint of imparting the function as a film-laminated metal sheet, lamination in the thickness direction is preferred. As for the lamination method, for example, co-extrusion using a feed block method or a multi-manifold method can be used; lamination method that bonds with other films and directly laminates the molten resin composition onto the film; and so on. In addition, coating method that involves coating a resin composition dissolved in a solvent onto the film and then drying it can also be used.

[0058] From the viewpoint of suppressing thickness unevenness and considering that biaxially oriented crystals in the case of polyester resin contribute to heat resistance, the resin film used in the film-laminated metal sheet of the present invention is preferably a biaxially stretched film. As a method of biaxial stretching, a successive biaxial stretching method in which longitudinal (length direction) and transverse (width direction) stretching are performed sequentially, or a simultaneous biaxial stretching method in which longitudinal and transverse stretching are performed simultaneously, can be used. In the case of the successive biaxial stretching method, from the viewpoint of uniform quality and saving equipment space, it is preferable to stretch longitudinally and then stretch transversely.

[0059] Next, the manufacturing method of the film-laminated metal sheet according to the present invention will be described, but it is not necessarily limited thereto. When manufacturing the film-laminated metal sheet according to the present invention, firstly, the preferred polyester resin described above is prepared in the form of granules or the like. The granules are dried in hot air or under vacuum as needed and then fed to an extruder along with various additives. Inside the extruder, the extrusion rate of the resin, which is heated and melted above its melting point, is uniformly controlled by a gear pump or the like, and foreign matter and deteriorated resin are removed by a filter or the like. In the case of a laminated structure, it is supplied to a different extruder than described above, and each is fed into a laminating device through a different flow path. As the laminating device, a feed head or a multi-manifold die can be used.

[0060] These resins are formed into sheets using a T-die and then discharged. The molten sheet discharged from the T-die is extruded onto a cooling body such as a casting roller, where it is cooled and solidified to obtain an unstretched film. At this point, to improve the adhesion between the cooling body (casting roller, etc.) and the molten sheet, it is preferable to use wire-shaped, strip-shaped, needle-shaped, or blade-shaped electrodes to achieve adhesion and rapid cooling and solidification through electrostatic force. Alternatively, methods such as blowing gas from a slit-shaped, point-shaped, or surface-shaped device to achieve adhesion and rapid cooling and solidification, using rollers to achieve adhesion and rapid cooling and solidification, and combining these methods are also preferred.

[0061] The unstretched membrane obtained in this manner is preferably biaxially stretched in both the longitudinal (length direction) and transverse (width direction). Here, the successive biaxial stretching method, in which the membrane is stretched in the longitudinal direction and then in the transverse direction, will be described.

[0062] First, the obtained unstretched film is stretched longitudinally. Here, longitudinal stretching refers to stretching that imparts molecular orientation to the film along its length. This is typically achieved using a difference in the circumferential speed of rollers. Stretching in the direction of travel can be performed in one stage, or in multiple stages using multiple roller pairs. The stretching ratio in longitudinal stretching varies depending on the type of resin, but is preferably 3.0 to 6.0 times. More preferably, it is 3.3 to 5.0 times, and even more preferably, it is 3.5 to 4.5 times. If the stretching ratio is within the above range, a film with minimal surface roughness, i.e., a surface arithmetic mean roughness Sa, maximum peak height Sp, and maximum valley depth Sv are controlled within a small and preferred range, can be obtained efficiently.

[0063] Furthermore, the stretching temperature during longitudinal stretching is preferably above the glass transition temperature of the resin constituting the resin film and below the glass transition temperature +50°C. More preferably, it is above the glass transition temperature +5°C and below the glass transition temperature +40°C, and particularly preferably, it is above the glass transition temperature +10°C and below the glass transition temperature +30°C. If the stretching temperature is within the above range, a film with minimal surface roughness, i.e., a surface arithmetic mean roughness Sa, maximum peak height Sp, and maximum valley depth Sv are controlled within a small and preferred range, can be obtained efficiently.

[0064] The uniaxially stretched resin film is temporarily cooled, and then, holding the ends of the resin film, it is introduced into a tenter-type stretching machine. The stretching ratio during transverse stretching is preferably 3.0 to 8.0 times, more preferably 3.5 to 7.0 times, and even more preferably 4.0 to 6.0 times. If the stretching ratio is within the above range, films with small thickness non-uniformity and minimal surface unevenness can be efficiently obtained; that is, the arithmetic mean surface roughness Sa, maximum peak height Sp, and maximum valley depth Sv are controlled within a small and preferred range.

[0065] The stretching temperature during transverse stretching is preferably above the glass transition temperature of the resin constituting the resin film and below the glass transition temperature +80°C. More preferably, it is above the glass transition temperature +10°C and below the glass transition temperature +70°C, and particularly preferably, it is above the glass transition temperature +15°C and below the glass transition temperature +60°C. If the stretching temperature is within the above range, a film with small thickness non-uniformity and small surface unevenness can be efficiently obtained, that is, the arithmetic mean surface roughness Sa, maximum peak height Sp, and maximum valley depth Sv are controlled within a small and preferred range.

[0066] The transversely stretched film is preferably then heat-cured. Heat curing is preferably performed in a tenter frame preheated to a high temperature. The heat curing temperature is preferably above the stretching temperature during transverse stretching and below the melting point of -50°C. More preferably, it is above the stretching temperature during transverse stretching and below the melting point of -60°C. Particularly preferably, it is above the stretching temperature during transverse stretching and below the melting point of -70°C. If the heat curing temperature is within the above range, films with small thickness non-uniformity and minimal surface unevenness can be efficiently obtained; that is, the arithmetic mean surface roughness Sa, maximum peak height Sp, and maximum valley depth Sv are controlled within a small and preferred range.

[0067] Furthermore, heat-fixing can be performed while simultaneously relaxing the film along its length and / or width. The relaxation rate is preferably 0.3% to 5.0%, more preferably 0.5% to 4.0%, and even more preferably 0.8% to 3.0%. It is preferable to further reduce the residual stress of the biaxially oriented resin film by relaxing simultaneously with heat-fixing. If the relaxation rate is within the above range, residual stress can be reduced more effectively, resulting in a film with small thickness non-uniformity and minimal surface unevenness. That is, a film with a small and preferred range of surface arithmetic mean roughness Sa, maximum peak height Sp, and maximum valley depth Sv can be efficiently obtained. The heat-fixed resin film is then slowly cooled in a tenter frame to obtain a biaxially stretched film.

[0068] It should be noted that, in the aforementioned resin film, from the perspective of maintaining a high degree of surface smoothness of the laminated metal sheet, it is preferable to adhere a protective film to at least the opposite side of the side bonded to the metal sheet (i.e., the surface side of the film-laminated metal sheet). That is, it is preferable to control the arithmetic mean roughness Sa, maximum peak height Sp, maximum valley depth Sv, and ku of the resin film surface within a small and preferred range. The protective film prevents scratches and indentations from appearing on the surface during lamination onto the metal sheet and when used as a flexible electronic substrate. The protective film adhered to the resin film is preferably made of polyester resin such as PET or PEN to prevent melting and dimensional changes during hot-press lamination. Furthermore, since the protective film needs to be peeled off when used as a flexible electronic substrate, it is preferable that the bonding surface with the resin film is slightly adhesive.

[0069] The resin film described above is coated onto a metal plate by hot pressing. Specifically, there is a method in which the metal plate is heated to a temperature exceeding the melting point of the resin film, and the resin film is brought into contact with one or both sides of the metal plate using a pressing roller and hot-pressed (hot-press film lamination method). When using this method, it is preferred from the following aspects: no organic solvents are used, large-scale drying ovens are used, resulting in low environmental impact, and metal plates coated with resin films on both sides can be obtained in a roll-to-roll manner, resulting in excellent productivity. In addition, it is also preferred from the following aspects: no adhesives are used, and the metal plate is composed only of a resin film as an insulating film and a metal plate with heat resistance, flexibility, and gas barrier properties, so impurities that would reduce the luminous efficiency of organic ELs are less likely to be mixed in. When used as a substrate for flexible electronics, transparent electrodes such as ITO are sometimes formed on the surface by etching, but the metal plate may dissolve in the etching solution. Therefore, it is preferable to laminate resin films on both sides of the metal plate. It should be noted that for resin films whose side is opposite to the resin film covered by the present invention, there is no particular limitation as long as the resin film is in close contact with the metal plate, but thermoplastic resin films are preferred. For example, commercially available PET film can be used.

[0070] The resin film coated on the metal plate in this invention needs to maintain surface smoothness and heat resistance; therefore, it is preferable that only a very small thickness portion in contact with the metal plate is melted and bonded to the metal plate. Regarding the temperature of the metal plate at the start of lamination, for polyester resin films, a melting point of -20°C or higher and below the melting point is preferred, more preferably -15°C or higher and -5°C or lower. For acrylic resins and polycarbonate resin films, a glass transition temperature of +20°C or higher and below +100°C is preferred, more preferably +40°C or higher and below +80°C.

[0071] Within this range, the desired adhesion and surface smoothness between the resin film and the metal plate can be obtained. That is, a film-laminated metal plate with a low arithmetic mean roughness Sa, maximum peak height Sp, maximum valley depth Sv, and kurtosis Sku of the resin film surface can be obtained. Furthermore, cold crystallization is less likely to occur, and the ΔHc / ΔHm and glass transition temperature Tg of the resin film are easily controlled within preferred ranges. As for the temperature history experienced by the film during lamination, the time for applying pressure to the film with laminating rollers is preferably set to 15 msec to 35 msec. More preferably, it is set to 20 msec to 30 msec. Within this range, deformation of the film surface caused by the lamination temperature history can be suppressed, and the desired adhesion and surface smoothness between the resin film and the metal plate can be obtained. That is, a film-laminated metal plate with a low arithmetic mean roughness Sa, maximum peak height Sp, maximum valley depth Sv, and kurtosis Sku of the resin film surface can be obtained. Furthermore, cold crystallization is less likely to occur, and the ΔHc / ΔHm and glass transition temperature Tg of the resin film are easier to control within the preferred range. Regarding the pressure applied by the pressing rollers during lamination, using a surface pressure gauge, it is preferably set to 10 kgf / cm². 2 Above 25kgf / cm 2 Below. Furthermore, 12 kgf / cm² is more preferred. 2 Above 23kgf / cm 2 A further preferred value is 15 kgf / cm². 2 Above 20kgf / cm 2 Within this range, the generation of air bubbles mixed between the film and the metal plate during lamination can be suppressed, and the desired adhesion and surface smoothness between the resin film and the metal plate can be obtained. That is, a film-laminated metal plate with small and preferred arithmetic mean roughness Sa, maximum peak height Sp, maximum valley depth Sv, and ku of the resin film surface can be obtained.

[0072] Furthermore, it is preferable to pre-cool the surface of the resin film, which is not in close contact with the metal plate, in a manner unaffected by the heat transfer process. Methods for cooling the surface of the resin film include: clamping with cooling rollers, cooling the surface with cooling gas, and surrounding the laminated portion with a cooling tank; clamping with cooling rollers is preferred. The temperature of the cooling rollers is preferably set to 20°C or higher and 50°C or lower. The temperature of the lamination cooling rollers is more preferably set to 25°C or higher and 45°C or lower. Within this range, deformation of the film surface caused by the lamination temperature process can be suppressed, resulting in the desired adhesion between the resin film and the metal plate and the surface smoothness. That is, a film-laminated metal plate with low arithmetic mean roughness Sa, maximum peak height Sp, maximum valley depth Sv, and ku is preferred. Furthermore, cold crystallization is less likely to occur, and the ΔHc / ΔHm and glass transition temperature Tg of the resin film are easily controlled within preferred ranges. The laminated metal plate is preferably immediately water-cooled to avoid damaging the surface smoothness and heat resistance of the resin film. The time from resin film lamination to water cooling is preferably set to 0.1 seconds to 0.8 seconds. Within this range, the arithmetic mean roughness Sa, maximum peak height Sp, maximum valley depth Sv, and ku of the resin film surface can be controlled to be small. In addition, cold crystallization is less likely to occur, and the ΔHc / ΔHm and glass transition temperature Tg of the resin film are also easier to control within the preferred range. Therefore, a film-laminated metal sheet with better surface smoothness and heat resistance can be obtained.

[0073] As the metal sheet involved in this invention, aluminum sheets, mild steel sheets, etc., which are widely used as can materials, can be used. In particular, surface-treated steel sheets (so-called TFS) with a two-layer film formed of metallic chromium at the bottom and chromium hydroxide at the top are most suitable. The amount of metallic chromium and chromium hydroxide layers adhering to TFS is not particularly limited. From the viewpoint of post-processing adhesion and corrosion resistance, based on Cr conversion, a metallic chromium layer of 50 mg / m³ is expected. 2 Above 200mg / m 2 The following chromium hydroxide layer is 5 mg / m² 2 Above 35mg / m 2 the following.

[0074] The film-laminated metal sheet of the present invention is suitable for use as a substrate for flexible electronics from the viewpoints of smoothness, heat resistance, flexibility, and gas barrier properties. It is particularly preferred for use in organic EL.

[0075] Example

[0076] The present invention will now be described in detail using examples.

[0077] (Example 1)

[0078] As the raw material for the resin film, PET granules with a glass transition temperature of 80°C and a melting point of 250°C were prepared and thoroughly dried under vacuum at high temperature to remove all moisture. The granules, free of particles intended for slipperiness and anti-blocking properties, were fed into a single-screw extruder and melt-blended at 280°C. Next, after removing impurities using a 25μm cut sintering filter, the film was discharged from a T-die and cooled and cured on a casting roller with a surface temperature controlled at 25°C to obtain an unstretched film. The film was then preheated using heated ceramic rollers to a resin film temperature of 95°C and stretched 3.5 times longitudinally. Then, the film was held at the ends and introduced into a tenter frame for transverse stretching at 100°C at 4.0 times. In this state, heat-fixing was performed at 140°C while a relaxation of 0.8% was applied transversely. Then, after slow cooling to room temperature, the resin film with the ends removed is wound using a winding machine to obtain a biaxially stretched film with a thickness of 50 μm. Next, a 125 μm thick PEN protective film is laminated onto the obtained biaxially stretched film. Then, the obtained biaxially stretched film is laminated onto a metal plate. As the metal plate, a 0.22 mm thick TFS (metal Cr layer: 120 mg / m³) was used. 2 Cr oxide layer: Calculated as 10 mg / m³ based on metallic Cr. 2 The resin film described above was coated onto both sides of a metal plate using a hot-press lamination method. The biaxially stretched film obtained above was laminated onto one surface of the metal plate, and a PET film (Lumirror (registered trademark) S10: 20μm) manufactured by Toray Industries, Ltd. was laminated onto the other surface. Specific lamination conditions were set as follows: metal plate temperature before lamination 245°C, lamination cooling roller temperature 25°C, and lamination pressure surface 15 kgf / cm². 2 The pressing time using the laminating roller is 20 minutes. It should be noted that the temperature during lamination is measured using a radiation thermometer at a position 100 mm from the clamping point before lamination. Then, water cooling is performed 0.1 seconds after hot pressing to obtain a film-laminated metal sheet with resin film coated on both sides of the metal sheet.

[0079] (Example 2)

[0080] Except for containing 300 ppm of SiO2 particles with an average particle size of 0.1 μm along with PET resin to improve the handling and winding properties of the membrane during manufacturing, a membrane-laminated metal sheet was obtained in the same manner as in Example 1.

[0081] (Example 3)

[0082] Except that it contains 500 ppm of SiO2 particles with an average particle size of 0.1 μm along with PET resin, a film-laminated metal sheet was obtained in the same manner as in Example 1.

[0083] (Example 4)

[0084] In addition to setting the lamination pressure surface pressure to 12 kgf / cm² 2 In addition, a film-laminated metal plate was obtained in the same manner as in Example 1.

[0085] (Example 5)

[0086] In addition to setting the lamination surface pressure to 10 kgf / cm² 2 In addition, a film-laminated metal plate was obtained in the same manner as in Example 1.

[0087] (Example 6)

[0088] In addition to setting the lamination surface pressure to 23 kgf / cm² 2 In addition, a film-laminated metal plate was obtained in the same manner as in Example 1.

[0089] (Example 7)

[0090] In addition to setting the lamination surface pressure to 25 kgf / cm² 2 In addition, a film-laminated metal plate was obtained in the same manner as in Example 1.

[0091] (Example 8)

[0092] Except that it contains 300 ppm of SiO2 particles with an average particle size of 0.2 μm along with PET resin, a film-laminated metal sheet was obtained in the same manner as in Example 1.

[0093] (Example 9)

[0094] Except that it contains 300 ppm of SiO2 particles with an average particle size of 0.3 μm along with PET resin, a film-laminated metal sheet was obtained in the same manner as in Example 1.

[0095] (Example 10)

[0096] Except that it contains 800 ppm of SiO2 particles with an average particle size of 0.1 μm along with PET resin, a film-laminated metal sheet was obtained in the same manner as in Example 1.

[0097] (Example 11)

[0098] Except that it contains 1000 ppm of SiO2 particles with an average particle size of 0.1 μm along with PET resin, a film-laminated metal sheet was obtained in the same manner as in Example 1.

[0099] (Example 12)

[0100] In addition to containing 300 ppm of SiO2 particles with an average particle size of 0.2 μm along with PET resin, the lamination pressure is set to 10 kgf / cm².2 In addition, a film-laminated metal plate was obtained in the same manner as in Example 1.

[0101] (Example 13)

[0102] Except for setting the temperature at the start of lamination to 251°C and the time from pressing the resin film to water cooling to 1.0 second, a film-laminated metal plate was obtained in the same manner as in Example 1.

[0103] (Example 14)

[0104] Except for controlling the amount of resin discharged from the T-die in a manner that makes the thickness of the biaxially stretched film 110 μm, a film-laminated metal sheet was obtained in the same manner as in Example 1.

[0105] (Example 15)

[0106] Except that the resin film was set to PMMA resin with a glass transition temperature of 125°C and the temperature of the metal plate at the start of lamination was set to 205°C, the film-laminated metal plate was obtained in the same manner as in Example 1.

[0107] (Example 16)

[0108] Except that the resin film was set to PC (polycarbonate) resin with a glass transition temperature of 150°C and the temperature of the metal plate at the start of lamination was set to 230°C, the film-laminated metal plate was obtained in the same manner as in Example 1.

[0109] (Comparative Example 1)

[0110] Except that it contains 1000 ppm of SiO2 particles with an average particle size of 0.5 μm along with PET resin, a film-laminated metal sheet was obtained in the same manner as in Example 1.

[0111] (Comparative Example 2)

[0112] Except that an unstretched film was formed without stretching, a film-laminated metal sheet was obtained in the same manner as in Example 1.

[0113] (Comparative Example 3)

[0114] Except for using a polyester adhesive to laminate the metal plate and the resin film instead of the hot-pressing lamination method, a film-laminated metal plate was obtained in the same manner as in Example 1.

[0115] The properties of the obtained film-laminated metal plates were measured and evaluated using the methods shown below.

[0116] (1) Arithmetic mean roughness, maximum peak height, maximum valley depth, kurtosis

[0117] Measurements were performed using an Olympus LEXT (OLS5000) 3D measuring laser microscope with a 50x objective lens (following ISO 25178-2:2012). The measurement range was set to 250 μm × 250 μm, and measurements were conducted at room temperature in atmospheric conditions. For resin films laminated with metal plates, measurements were taken at three randomly selected locations, and the average values ​​for arithmetic mean roughness Sa, maximum peak height Sp, maximum valley depth Sv, and kurtosis Sku were calculated.

[0118] (2) Ash content

[0119] The metal plate of the membrane-laminated metal plate was dissolved with hydrochloric acid, and the resin membrane was collected. Following JIS K7250, the resin membrane with an initial mass W0 was placed in a platinum crucible. It was first fully combusted using a gas burner, and then completely ashed in an electric furnace at 750–800°C for 1 hour. The mass W1 of the obtained ash was measured and calculated using the following formula. Three identical measurements were performed, and the average value was taken as the ash content.

[0120] Ash content = (W1 / W0) × 1,000,000 (ppm)

[0121] (3) Static friction coefficient

[0122] The laminated metal plate was cut into sample sizes of 150mm × 40mm and measured using a TYPE:10 static friction coefficient measuring machine manufactured by Shin-To Science Co., Ltd., with a 150g flat indenter. Five identical measurements were performed for each sample, and the average value was taken as the static friction coefficient.

[0123] (4) Resin film thickness

[0124] The metal plate of the membrane lamination was dissolved with hydrochloric acid, and the resin membrane was collected. The thickness of the collected resin membrane was measured using a Mitutoyo 2110S-10 dial indicator (with a probe equipped with an ultra-hard ball) mounted on a Mitutoyo 7001-10 dial indicator stand. Measurements were taken at 10 randomly selected locations, and the average value was taken as the thickness of the resin membrane.

[0125] (5) Thermal properties of resin film (heat of cold crystallization, heat of melting, glass transition temperature)

[0126] After cutting the film-laminating metal plate into sample sizes of 10mm × 10mm, it was immersed in hydrochloric acid until the metal plate dissolved, thus separating the resin film. 5mg of the separated resin film was collected as a sample in an aluminum dish and measured using a TA Instruments differential scanning calorimeter (DSC-Q100). First, it was cooled to -50℃ under a nitrogen atmosphere, and then heated to 290℃ at a rate of 20℃ / min (1st Run). The heat of crystallization, heat of fusion, and glass transition temperature were calculated from the table obtained in the 1st Run. Three identical measurements were performed for each, and the average values ​​were taken as the heat of crystallization ΔHc, heat of fusion ΔHm, and glass transition temperature Tg of the resin film.

[0127] (6) The luminescent appearance of substrates for organic EL

[0128] Using a laminated metal plate as a substrate, an anode (aluminum-gold electrode), a hole transport layer, a light-emitting layer / electron transport layer, and a semi-transparent cathode (silver-magnesium electrode) are sequentially vacuum-deposited onto the surface of a resin film. It should be noted that a metal mask is set to achieve a light-emitting area of ​​2mm × 2mm. The specific method for fabricating an organic EL device is shown below. First, the substrate is cleaned and dried at 110°C for 1 hour. Then, the substrate is placed in a vacuum evaporation machine, and the pressure is reduced to below 0.001Pa. Next, aluminum and gold are deposited as the anode, and α-NPD (N,N'-diphenyl-N,N'-di(α-naphthyl)-benzidine) is formed as the hole transport layer, covering the anode, at a deposition rate of 6nm / min, and a film thickness of 50nm. Alq3 (tris(8-hydroxyquinoline)aluminum) is formed on top of this hole transport layer at a deposition rate of 6nm / min and a film thickness of 50nm as the light-emitting layer / electron transport layer. Finally, silver and magnesium are deposited as semi-transparent electrodes to form the cathode. The organic EL device fabricated in this manner is sealed. It should be noted that 20 elements are fabricated using the same method for the organic EL device. A voltage of 10V is applied to each of the 20 elements, and the luminescence of the organic EL is confirmed. The average number of black spots on each element is calculated, and the luminescence appearance of the organic EL substrate is evaluated using the following criteria.

[0129] A (Excellent): 0 black spots

[0130] B (Good): Number of dark spots: 1-10

[0131] C (Pass): Number of black spots: 11-100

[0132] D (Unacceptable): More than 101 black spots

[0133] (7) Electrical insulation properties of substrates for organic EL

[0134] Similar to the previous step, 20 components were fabricated for organic EL devices. Each component was powered at 10V, and the light emission of the organic EL was verified. The electrical insulation of the substrate for organic EL was evaluated using the following criteria.

[0135] A (Excellent): All 20 components are lit.

[0136] B (Good): 15-19 out of 20 components are emitting light (1-5 components are short-circuited).

[0137] C (Pass): 1-14 out of 20 components emit light (6-19 components are short-circuited).

[0138] D (Failure): All 20 components are short-circuited and do not emit light.

[0139] (8) Luminous efficiency of substrates for organic EL

[0140] Similar to the previous step, 20 organic EL devices were fabricated, and the current density of each device was measured when energized at 5V. Excluding short-circuited devices, the average current density was used as the leakage current, and the luminous efficiency of the organic EL substrate was evaluated using the following criteria.

[0141] A (Excellent): Current density less than 1.0 × 10⁻⁶ -5 mA / cm 2

[0142] B (Good): Current density 1.0 × 10 -5 mA / cm 2 Above 1.0×10 -3 mA / cm 2 the following

[0143] C (Pass): Current density 1.0 × 10 -3 mA / cm 2 Above 1.0×10 -1 mA / cm 2 the following

[0144] D (Unacceptable): Current density exceeds 1.0 × 10⁻⁶ -1 mA / cm 2 Or all short circuits

[0145] The results of evaluating the organic EL substrates of Examples 1-16 and Comparative Examples 1-3 are shown in Table 1 below. It should be noted that the presence of "-" in the table indicates that there is no Tg.

[0146] [Table 1]

[0147]

[0148] As shown in Table 1, in Comparative Examples 1-3, one or all of the following—luminous appearance, electrical insulation, and luminous efficiency—received a D (unacceptable) rating. In contrast, in Examples 1-16, any or all of the following—luminous appearance, electrical insulation, and luminous efficiency—received a C (acceptable) rating or higher. These are characteristics improved by achieving excellent smoothness and heat resistance, which are the subject of this invention. Thus, it is confirmed that, according to the present invention, a film-laminated metal sheet that satisfies the smoothness required for flexible electronic substrates can be provided. Furthermore, the film-laminated metal sheet of the present invention possesses excellent characteristics for flexible electronic substrates, such as flexibility, gas barrier properties, low environmental impact, and high productivity.

[0149] Industrial availability

[0150] According to the present invention, it is possible to provide film-laminated metal sheets, flexible electronic substrates, and organic EL substrates that not only meet the requirements of smoothness, heat resistance, flexibility, and gas barrier properties, but also have low environmental impact and excellent productivity.

Claims

1. A film-laminated metal sheet, wherein at least one side is coated with a resin film by heat pressing. The arithmetic mean roughness Sa of the resin film surface is below 0.030 μm. The maximum peak height Sp on the surface of the resin film is below 0.30 μm. The maximum valley depth Sv on the surface of the resin film is less than 1.0 μm. The kurtosis Sku on the surface of the resin film is below 3.

0. The ratio of the cold crystallization heat ΔHc to the melting heat ΔHm of the resin film, as determined by DSC, i.e., ΔHc / ΔHm, is less than 0.

30.

2. The film-laminated metal plate as described in claim 1, wherein, The ash content of the resin film is below 1000 ppm.

3. The film-laminated metal sheet as described in claim 1 or 2, wherein, The static friction coefficient μs of the resin film is above 0.10 and below 1.

0.

4. The film-laminated metal sheet as described in claim 1 or 2, wherein, The glass transition temperature (Tg) of the resin film is above 120°C and below 200°C.

5. The film-laminated metal plate as described in claim 3, wherein, The glass transition temperature (Tg) of the resin film is above 120°C and below 200°C.

6. The film-laminated metal sheet according to any one of claims 1, 2, and 5, wherein, The thickness of the resin film is between 10 μm and 100 μm.

7. The film-laminated metal plate as described in claim 3, wherein, The thickness of the resin film is between 10 μm and 100 μm.

8. The film-laminated metal plate as described in claim 4, wherein, The thickness of the resin film is between 10 μm and 100 μm.

9. The film-laminated metal sheet according to any one of claims 1, 2, 5, 7, and 8, wherein, The main component of the resin film is any one of polyester resin, acrylic resin, or polycarbonate resin.

10. The film-laminated metal plate as described in claim 3, wherein, The main component of the resin film is any one of polyester resin, acrylic resin, or polycarbonate resin.

11. The film-laminated metal plate as claimed in claim 4, wherein, The main component of the resin film is any one of polyester resin, acrylic resin, or polycarbonate resin.

12. The film-laminated metal plate as described in claim 6, wherein, The main component of the resin film is any one of polyester resin, acrylic resin, or polycarbonate resin.

13. A method for manufacturing a film-laminated metal sheet according to any one of claims 1 to 12, wherein, The resin film is coated onto the metal plate by hot pressing.

14. A flexible electronic substrate, wherein the film-laminated metal plate according to any one of claims 1 to 12 is used.

15. An organic EL substrate, wherein the film-laminated metal plate according to any one of claims 1 to 12 is used.

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